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Sample records for complete phb mobilization

  1. To be or not to be a poly(3-hydroxybutyrate) (PHB) depolymerase: PhaZd1 (PhaZ6) and PhaZd2 (PhaZ7) of Ralstonia eutropha, highly active PHB depolymerases with no detectable role in mobilization of accumulated PHB.

    Science.gov (United States)

    Sznajder, Anna; Jendrossek, Dieter

    2014-08-01

    The putative physiological functions of two related intracellular poly(3-hydroxybutyrate) (PHB) depolymerases, PhaZd1 and PhaZd2, of Ralstonia eutropha H16 were investigated. Purified PhaZd1 and PhaZd2 were active with native PHB granules in vitro. Partial removal of the proteinaceous surface layer of native PHB granules by trypsin treatment or the use of PHB granules isolated from ΔphaP1 or ΔphaP1-phaP5 mutant strains resulted in increased specific PHB depolymerase activity, especially for PhaZd2. Constitutive expression of PhaZd1 or PhaZd2 reduced or even prevented the accumulation of PHB under PHB-permissive conditions in vivo. Expression of translational fusions of enhanced yellow fluorescent protein (EYFP) with PhaZd1 and PhaZd2 in which the active-site serines (S190 and Ser193) were replaced with alanine resulted in the colocalization of only PhaZd1 fusions with PHB granules. C-terminal fusions of inactive PhaZd2(S193A) with EYFP revealed the presence of spindle-like structures, and no colocalization with PHB granules was observed. Chromosomal deletion of phaZd1, phaZd2, or both depolymerase genes had no significant effect on PHB accumulation and mobilization during growth in nutrient broth (NB) or NB-gluconate medium. Moreover, neither proteome analysis of purified native PHB granules nor lacZ fusion studies gave any indication that PhaZd1 or PhaZd2 was detectably present in the PHB granule fraction or expressed at all during growth on NB-gluconate medium. In conclusion, PhaZd1 and PhaZd2 are two PHB depolymerases with a high capacity to degrade PHB when artificially expressed but are apparently not involved in PHB mobilization in the wild type. The true in vivo functions of PhaZd1 and PhaZd2 remain obscure. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  2. Prohibitin( PHB) roles in granulosa cell physiology.

    Science.gov (United States)

    Chowdhury, Indrajit; Thomas, Kelwyn; Thompson, Winston E

    2016-01-01

    Ovarian granulosa cells (GC) play an important role in the growth and development of the follicle in the process known as folliculogenesis. In the present review, we focus on recent developments in prohibitin (PHB) research in relation to GC physiological functions. PHB is a member of a highly conserved eukaryotic protein family containing the repressor of estrogen activity (REA)/stomatin/PHB/flotillin/HflK/C (SPFH) domain (also known as the PHB domain) found in diverse species from prokaryotes to eukaryotes. PHB is ubiquitously expressed in a circulating free form or is present in multiple cellular compartments including mitochondria, nucleus and plasma membrane. In mitochondria, PHB is anchored to the mitochondrial inner membrane and forms complexes with the ATPases associated with proteases having diverse cellular activities. PHB continuously shuttles between the mitochondria, cytosol and nucleus. In the nucleus, PHB interacts with various transcription factors and modulates transcriptional activity directly or through interactions with chromatin remodeling proteins. Many functions have been attributed to the mitochondrial and nuclear PHB complexes such as cellular differentiation, anti-proliferation, morphogenesis and maintenance of the functional integrity of the mitochondria. However, to date, the regulation of PHB expression patterns and GC physiological functions are not completely understood.

  3. Ralstonia eutropha's Poly(3-hydroxybutyrate)(PHB) polymerase PhaC1 and PHB depolymerase PhaZa1 are phosphorylated in vivo.

    Science.gov (United States)

    Jüngert, Janina R; Patterson, Cameron; Jendrossek, Dieter

    2018-04-20

    In this study, we screened PHB synthase PhaC1 and PHB depolymerase PhaZa1 of Ralstonia eutropha for the presence of phosphorylated residues during the PHB accumulation and PHB degradation phase. Thr373 of PHB synthase PhaC1 was phosphorylated in the stationary growth phase but was not modified in the exponential and PHB accumulation phases. Ser35 of PHB depolymerase PhaZa1 was identified in phosphorylated form both in the exponential and in the stationary growth phase. Additional phosphosites were identified for both proteins in sample-dependent forms. Site-directed mutagenesis of the codon for Thr373 and other phosphosites of PhaC1 revealed a strong negative impact on PHB synthase activity. Modification of Thr26 and Ser35 of PhaZa1 reduced the ability of R. eutropha to mobilize PHB in the stationary growth phase. Our results show that phosphorylation of PhaC1 and PhaZa1 can be important for modulation of the activities of PHB synthase and PHB depolymerase. Importance Polyhydroxybutyrate (PHB) and related polyhydroxyalkanoates (PHAs) are important intracellular carbon and energy storage compounds in many prokaryotes. The accumulation of PHB or PHAs increases the fitness of cells during periods of starvation and other stress conditions. The simultaneous presence of poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) and PHB depolymerase (PhaZa1) on synthesized PHB granules in Ralstonia eutropha (alternative designation Cupriavidus necator ) has been previously shown in several laboratories. These findings imply that the activities of PHB synthase and PHB depolymerase should be regulated to avoid a futile cycle of simultaneous synthesis and degradation of PHB. Here, we addressed this question by identifying phosphorylation sites on PhaC1 and PhaZa1 and by site-directed mutagenesis of identified residues. Furthermore, we conducted in vitro and in vivo analysis of PHB synthase activity and PHB contents. Copyright © 2018 American Society for Microbiology.

  4. Purification, immobilization, and characterization of nattokinase on PHB nanoparticles.

    Science.gov (United States)

    Deepak, Venkataraman; Pandian, Suresh babu Ram Kumar; Kalishwaralal, Kalimuthu; Gurunathan, Sangiliyandi

    2009-12-01

    In this study, nattokinase was purified from Bacillus subtilis using ion exchange chromatography and immobilized upon polyhydroxybutyrate (PHB) nanoparticles. A novel strain isolated from industrial dairy waste was found to synthesize polyhydroxyalkanoates (PHA) and the strain was identified as Brevibacterium casei SRKP2. PHA granules were extracted from 48 h culture and the FT-IR analysis characterized them as PHB, a natural biopolymer from B. casei. Nanoprecipitation by solvent displacement technique was used to synthesize PHB nanoparticles. PHB nanoparticles were characterized using transmission electron microscopy and particle size ranged from 100-125 nm. Immobilization of nattokinase upon PHB nanoparticles resulted in a 20% increase in the enzyme activity. Immobilization also contributed to the enhanced stability of the enzyme. Moreover, the activity was completely retained on storage at 4 degrees C for 25 days. The method has proven to be highly simple and can be implemented to other enzymes also.

  5. PHB Biosynthesis Counteracts Redox Stress in Herbaspirillum seropedicae

    Directory of Open Access Journals (Sweden)

    Marcelo B. Batista

    2018-03-01

    Full Text Available The ability of bacteria to produce polyhydroxyalkanoates such as poly(3-hydroxybutyrate (PHB enables provision of a carbon storage molecule that can be mobilized under demanding physiological conditions. However, the precise function of PHB in cellular metabolism has not been clearly defined. In order to determine the impact of PHB production on global physiology, we have characterized the properties of a ΔphaC1 mutant strain of the diazotrophic bacterium Herbaspirillum seropedicae. The absence of PHB in the mutant strain not only perturbs redox balance and increases oxidative stress, but also influences the activity of the redox-sensing Fnr transcription regulators, resulting in significant changes in expression of the cytochrome c-branch of the electron transport chain. The synthesis of PHB is itself dependent on the Fnr1 and Fnr3 proteins resulting in a cyclic dependency that couples synthesis of PHB with redox regulation. Transcriptional profiling of the ΔphaC1 mutant reveals that the loss of PHB synthesis affects the expression of many genes, including approximately 30% of the Fnr regulon.

  6. PHB Biosynthesis Counteracts Redox Stress in Herbaspirillum seropedicae.

    Science.gov (United States)

    Batista, Marcelo B; Teixeira, Cícero S; Sfeir, Michelle Z T; Alves, Luis P S; Valdameri, Glaucio; Pedrosa, Fabio de Oliveira; Sassaki, Guilherme L; Steffens, Maria B R; de Souza, Emanuel M; Dixon, Ray; Müller-Santos, Marcelo

    2018-01-01

    The ability of bacteria to produce polyhydroxyalkanoates such as poly(3-hydroxybutyrate) (PHB) enables provision of a carbon storage molecule that can be mobilized under demanding physiological conditions. However, the precise function of PHB in cellular metabolism has not been clearly defined. In order to determine the impact of PHB production on global physiology, we have characterized the properties of a Δ phaC1 mutant strain of the diazotrophic bacterium Herbaspirillum seropedicae . The absence of PHB in the mutant strain not only perturbs redox balance and increases oxidative stress, but also influences the activity of the redox-sensing Fnr transcription regulators, resulting in significant changes in expression of the cytochrome c -branch of the electron transport chain. The synthesis of PHB is itself dependent on the Fnr1 and Fnr3 proteins resulting in a cyclic dependency that couples synthesis of PHB with redox regulation. Transcriptional profiling of the Δ phaC1 mutant reveals that the loss of PHB synthesis affects the expression of many genes, including approximately 30% of the Fnr regulon.

  7. Mobile-robot navigation with complete coverage of unstructured environments

    OpenAIRE

    García Armada, Elena; González de Santos, Pablo

    2004-01-01

    There are some mobile-robot applications that require the complete coverage of an unstructured environment. Examples are humanitarian de-mining and floor-cleaning tasks. A complete-coverage algorithm is then used, a path-planning technique that allows the robot to pass over all points in the environment, avoiding unknown obstacles. Different coverage algorithms exist, but they fail working in unstructured environments. This paper details a complete-coverage algorithm for unstructured environm...

  8. Comparative proteome analysis reveals four novel polyhydroxybutyrate (PHB) granule-associated proteins in Ralstonia eutropha H16.

    Science.gov (United States)

    Sznajder, Anna; Pfeiffer, Daniel; Jendrossek, Dieter

    2015-03-01

    Identification of proteins that were present in a polyhydroxybutyrate (PHB) granule fraction isolated from Ralstonia eutropha but absent in the soluble, membrane, and membrane-associated fractions revealed the presence of only 12 polypeptides with PHB-specific locations plus 4 previously known PHB-associated proteins with multiple locations. None of the previously postulated PHB depolymerase isoenzymes (PhaZa2 to PhaZa5, PhaZd1, and PhaZd2) and none of the two known 3-hydroxybutyrate oligomer hydrolases (PhaZb and PhaZc) were significantly present in isolated PHB granules. Four polypeptides were found that had not yet been identified in PHB granules. Three of the novel proteins are putative α/β-hydrolases, and two of those (A0671 and B1632) have a PHB synthase/depolymerase signature. The third novel protein (A0225) is a patatin-like phospholipase, a type of enzyme that has not been described for PHB granules of any PHB-accumulating species. No function has been ascribed to the fourth protein (A2001), but its encoding gene forms an operon with phaB2 (acetoacetyl-coenzyme A [CoA] reductase) and phaC2 (PHB synthase), and this is in line with a putative function in PHB metabolism. The localization of the four new proteins at the PHB granule surface was confirmed in vivo by fluorescence microscopy of constructed fusion proteins with enhanced yellow fluorescent protein (eYFP). Deletion of A0671 and B1632 had a minor but detectable effect on the PHB mobilization ability in the stationary growth phase of nutrient broth (NB)-gluconate cells, confirming the functional involvement of both proteins in PHB metabolism. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. PLLA-PHB fiber membranes obtained by solvent-free electrospinning for short-time drug delivery.

    Science.gov (United States)

    Cao, K; Liu, Y; Olkhov, A A; Siracusa, V; Iordanskii, A L

    2018-02-01

    Fibers of poly(L-lactic acid) (PLLA)/polyhydroxybutyrate (PHB) with different concentrations of the drug dipyridamole (DPD) were prepared using solvent-free melt electrospinning to obtain a polymeric drug delivery system. The electrospun fibers were morphologically, structurally, thermally, and dynamically characterized. Crazes that resemble lotus root crevices were interestingly observed in the 7:3 PLLA/PHB fibers with 1% DPD. The crystallinity of PLLA slightly decreased as PHB was incorporated, and the addition of DPD significantly reduced the melting temperature of the composite. The interactions between PLLA and PHB mainly occurred at a proportion of 7:3, and drug encapsulation in the fibers was verified. The kinetic profiles of drug release demonstrated the predominant multiple patterns involving a diffusional stage in the short-term mode of release and kinetic process related to the hydrolysis of the biopolymers. Furthermore, the dynamic behavior of the polymer molecules was evaluated based on the segmental mobility using probe electron spin resonance spectroscopy. The segmental mobility in the amorphous fraction of PLLA decreased with increasing PLLA content. The 9:1 PLLA/PHB system was more resistant to polymer hydrolysis than to the 7:3 system and the rate of diffusion transport was approximately two times higher for the 7:3 PLLA/PHB fibers than for the 9:1 PLLA/PHB fibers.

  10. Effect of sodium accumulation on heterotrophic growth and polyhydroxybutyrate (PHB) production by Cupriavidus necator.

    Science.gov (United States)

    Mozumder, Md Salatul Islam; Garcia-Gonzalez, Linsey; De Wever, Heleen; Volcke, Eveline I P

    2015-09-01

    This study evaluates the effect of sodium (Na(+)) concentration on the growth and PHB production by Cupriavidus necator. Both biomass growth and PHB production were inhibited by Na(+): biomass growth became zero at 8.9 g/L Na(+) concentration while PHB production was completely stopped at 10.5 g/L Na(+). A mathematical model for pure culture heterotrophic PHB production was set up to describe the Na(+) inhibition effect. The parameters related to Na(+) inhibition were estimated based on shake flask experiments. The accumulated Na(+) showed non-linear inhibition effect on biomass growth but linear inhibition effect on PHB production kinetics. Fed-batch experiments revealed that a high accumulation of Na(+) due to a prolonged growth phase, using NaOH for pH control, decreased the subsequent PHB production. The model was validated based on independent experimental data sets, showing a good agreement between experimental data and simulation results. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Histological and molecular-biological analyses of poly(3-hydroxybutyrate) (PHB) patches for enhancement of bone regeneration.

    Science.gov (United States)

    Gredes, Tomasz; Gedrange, Tomasz; Hinüber, Claudia; Gelinsky, Michael; Kunert-Keil, Christiane

    2015-05-01

    Tissue engineered cell-seeded constructs with poly(3)hydroxybutyrate (PHB) induced ectopic bone formation after implantation into the back muscle of rats. The objective of our in vivo study was to evaluate the osteogenic potential of pure PHB patches in surgically created cranial defects. For this, PHB patches were analyzed after implantation in surgically created defects on the cranium of adult male rats. After healing periods of 4, 8 and 12 weeks, the bone tissue specimens containing PHB patches were processed and analyzed histologically as well as molecular-biologically. After 4 weeks, the PHB patches were completely embedded in connective tissue. Eight weeks after PHB insertion, bone regeneration proceeding from bearing bone was found in 50% of all treated animals, whereas all PHB treated cavities showed both bone formation and embedding of the patches in bone 12 weeks after surgery. Furthermore, all slices showed pronounced development of blood vessels. Histomorphometric analysis presented a regenerated bone mean value between 46.4 ± 16.1% and 54.2 ± 19.3% after 4-12 weeks of healing. Caveolin-1 staining in capillary-like structures showed a 1.16-1.38 fold increased expression in PHB treated defects compared to controls. Real-time RT-PCR analyses showed significantly lower expressions of Alpl, Col1a1 and VEGFA in cranium defects after treatment with PHB patches compared to untreated bony defects of the same cranium. Within the limits of the presented animal investigation, it could conclude that the tested PHB patches featured a good biocompatibility and an osteoconductive character. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. Controlling microbial PHB synthesis via CRISPRi.

    Science.gov (United States)

    Li, Dan; Lv, Li; Chen, Jin-Chun; Chen, Guo-Qiang

    2017-07-01

    Microbial polyhydroxyalkanoates (PHA) are a family of biopolyesters with properties similar to petroleum plastics such as polyethylene (PE) or polypropylene (PP). Polyhydroxybutyrate (PHB) is the most common PHA known so far. Clustered regularly interspaced short palindromic repeats interference (CRISPRi), a technology recently developed to control gene expression levels in eukaryotic and prokaryotic genomes, was employed to regulate PHB synthase activity influencing PHB synthesis. Recombinant Escherichia coli harboring an operon of three PHB synthesis genes phaCAB cloned from Ralstonia eutropha, was transformed with various single guided RNA (sgRNA with its guide sequence of 20-23 bases) able to bind to various locations of the PHB synthase PhaC, respectively. Depending on the binding location and the number of sgRNA on phaC, CRISPRi was able to control the phaC transcription and thus PhaC activity. It was found that PHB content, molecular weight, and polydispersity were approximately in direct and reverse proportion to the PhaC activity, respectively. The higher the PhaC activity, the more the intracellular PHB accumulation, yet the less the PHB molecular weights and the wider the polydispersity. This study allowed the PHB contents to be controlled in the ranges of 1.47-75.21% cell dry weights, molecular weights from 2 to 6 millions Dalton and polydispersity of 1.2 to 1.43 in 48 h shake flask studies. This result will be very important for future development of ultrahigh molecular weight PHA useful to meet high strength application requirements.

  13. Impact of Ralstonia eutropha's Poly(3-Hydroxybutyrate) (PHB) Depolymerases and Phasins on PHB Storage in Recombinant Escherichia coli

    OpenAIRE

    Eggers, Jessica; Steinbüchel, Alexander

    2014-01-01

    The model organism for polyhydroxybutyrate (PHB) biosynthesis, Ralstonia eutropha H16, possesses multiple isoenzymes of granules coating phasins as well as of PHB depolymerases, which degrade accumulated PHB under conditions of carbon limitation. In this study, recombinant Escherichia coli BL21(DE3) strains were used to study the impact of selected PHB depolymerases of R. eutropha H16 on the growth behavior and on the amount of accumulated PHB in the absence or presence of phasins. For this p...

  14. Morphology and dielectric properties of poly hydroxybutyrate(PHB)/polymethyl methacrylat(PMMA) blends with some antimicrobial applications

    International Nuclear Information System (INIS)

    Abou aiad, T.H.M.

    2005-01-01

    Poly(3-hydroxy)butyrate (PHB) is microbial polyester presenting the advantages of biodegradability and biocompatibility but suffers from several problems as it is brittle and has low abilities for some chemical modifications. To overcome such problems a reactive blending was done with a glassy acrylic polymer, poly(methyl methacrylate) (PMMA) with different compositions. The dielectric response of poly [(7)-3-hydroxybutyrate] (PHB)/(PMMA) was investigated as a function of frequency (100 Hz to 100 KHz) and at different temperatures from 20 to 160 degree C above the glass transition temperature of PHB. The results revealed the existence of a single relaxation process indicating that there is miscibility between amorphous fractions of PHB and PMMA. Subsequently a continuous decrease in relaxation strength occurred, indicating considerable changes in molecular mobility. The results provide further evidence that molecular mobility in the amorphous regions decreases significantly and this would be the reason for the embrittlement detected on ageing at room temperature. Also the morphological study of such blends don't show macro phase separation of PMMA on the surface scan which may be attributed to the compatibility in melt between PHB and PMMA particle in the PHB matrix. The biological activity of such investigated systems was tested against a representative number of pathogenic organisms by determining the minimum inhibitory concentration (MIC). The activity was found to increase by increasing the amount of PMMA in the blend

  15. Cyanobacterial Polyhydroxybutyrate (PHB): Screening, Optimization and Characterization.

    Science.gov (United States)

    Ansari, Sabbir; Fatma, Tasneem

    2016-01-01

    In modern life petroleum-based plastic has become indispensable due to its frequent use as an easily available and a low cost packaging and moulding material. However, its rapidly growing use is causing aquatic and terrestrial pollution. Under these circumstances, research and development for biodegradable plastic (bioplastics) is inevitable. Polyhydroxybutyrate (PHB), a type of microbial polyester that accumulates as a carbon/energy storage material in various microorganisms can be a good alternative. In this study, 23 cyanobacterial strains (15 heterocystous and 8 non-heterocystous) were screened for PHB production. The highest PHB (6.44% w/w of dry cells) was detected in Nostoc muscorum NCCU- 442 and the lowest in Spirulina platensis NCCU-S5 (0.51% w/w of dry cells), whereas no PHB was found in Cylindrospermum sp., Oscillatoria sp. and Plectonema sp. Presence of PHB granules in Nostoc muscorum NCCU- 442 was confirmed microscopically with Sudan black B and Nile red A staining. Pretreatment of biomass with methanol: acetone: water: dimethylformamide [40: 40: 18: 2 (MAD-I)] with 2 h magnetic bar stirring followed by 30 h continuous chloroform soxhlet extraction acted as optimal extraction conditions. Optimized physicochemical conditions viz. 7.5 pH, 30°C temperature, 10:14 h light:dark periods with 0.4% glucose (as additional carbon source), 1.0 gl-1 sodium chloride and phosphorus deficiency yielded 26.37% PHB on 7th day instead of 21st day. Using FTIR, 1H NMR and GC-MS, extracted polymer was identified as PHB. Thermal properties (melting temperature, decomposition temperatures etc.) of the extracted polymer were determined by TGA and DSC. Further, the polymer showed good tensile strength and young's modulus with a low extension to break ratio comparable to petrochemical plastic. Biodegradability potential tested as weight loss percentage showed efficient degradation (24.58%) of PHB within 60 days by mixed microbial culture in comparison to petrochemical plastic.

  16. [Increasing reductant NADPH content via metabolic engineering of PHB synthesis pathway in Synechocystis sp. PCC 6803].

    Science.gov (United States)

    Xie, Juan; Zhou, Jie; Zhang, Haifeng; Li, Yin

    2011-07-01

    Cyanobacteria have become attractive hosts for renewable chemicals production. The low productivity, however, prevents it from industrial application. Reductant NAD(P)H availability is a chief hurdle for the production of reductive metabolites in microbes. To increase NADPH content in Synechocystis sp. PCC 6803, PHB synthase encoding gene phaC and phaE in Synechocystis was inactivated by replacing phaC&E genes with chloromycetin resistance cassette via homologous recombination. PCR analysis showed that mutant S.delta phaC&E with complete genome segregation was generated. The comparison between growth curves of S.wt and S.delta phaC&E indicated the knockout of phaC & phaE genes did not affect obviously the cell growth. Gas chromatography analysis showed that the accumulation of PHB in wild type was about 2.3% of the dry cell weight, whereas no PHB was detected in the mutant S.delta phaC&E. The data indicated that inactivation of PHB synthase gene phaC and phaE interrupted the synthesis of PHB. Further comparative study of wild type and mutant demonstrated that NADPH content in S.delta phaC&E was obviously increased. On the third day, the NADPH content in S.delta phaC&E was up to 1.85 fold higher than that in wild type. These results indicated that deleting PHB synthase gene phaC and phaE not only can block the synthesis of PHB, but also can save NADPH to contribute reductant sink in cyanobacteria. Hence, the engineered cyanobacterial strain S.delta phaC&E, in which carbon flux was redirected and NADPH was increased, will be a potential host strain for chemicals production in cyanobacteria.

  17. Modeling pure culture heterotrophic production of polyhydroxybutyrate (PHB).

    Science.gov (United States)

    Mozumder, Md Salatul Islam; Goormachtigh, Laurens; Garcia-Gonzalez, Linsey; De Wever, Heleen; Volcke, Eveline I P

    2014-03-01

    In this contribution a mechanistic model describing the production of polyhydroxybutyrate (PHB) through pure-culture fermentation was developed, calibrated and validated for two different substrates, namely glucose and waste glycerol. In both cases, non-growth-associated PHB production was triggered by applying nitrogen limitation. The occurrence of some growth-associated PHB production besides non-growth-associated PHB production was demonstrated, although it is inhibited in the presence of nitrogen. Other phenomena observed experimentally and described by the model included biomass growth on PHB and non-linear product inhibition of PHB production. The accumulated impurities from the waste substrate negatively affected the obtained maximum PHB content. Overall, the developed mathematical model provided an accurate prediction of the dynamic behavior of heterotrophic biomass growth and PHB production in a two-phase pure culture system. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Effect of chain extension on rheology and tensile properties of PHB and PHB-PLA blends

    Science.gov (United States)

    Bousfield, Glenn

    Poly(3-hydroxybutyrate), referred to as PHB, is a bacterially-synthesized and biodegradable polymer which is being considered as a substitute for non-biodegradable bulk polymers like polypropylene. PHB is naturally extremely isotactic and naturally has a very high degree of crystallinity, resulting in a stiff but brittle material. The stability of PHB crystals also means that the melting point of the polymer is approximately 170°C, high with respect to similar polymers. For instance, the melting point of poly(4-hydroxybutyrate) is only 53°C (Saito, Nakamura, Hiramitsu, & Doi, 1996). Above 170°C, PHB is subject to a thermomechanical degradation mechanism, meaning that the polymer cannot be melted without degrading. One possible solution to the problem of degradation is to add a chain extender to the molten polymer to increase average molecular weight to counteract the molecular weight lost to degradation. In this work, a variety of chain extenders (JoncrylRTM ADR 4368-C, pyromellitic dianhydride, hexamethylene diisocyanate, polycarbodiimide) were compounded with a random copolymer of 98 mol% 3-hydroxybutyrate and 2 mol% 3-hydroxyvalerate (referred to as PHB) in concentrations ranging from 0.25% to 4%, to determine which chain extender functionality worked best with PHB. Molecular weight change was inferred from torque monitored during compounding, and from complex viscosity determined from parallel-plate rheology. None of the chain extenders changed the rate of degradation of PHB, although Joncryl increased the complex viscosity of the polymer. PHB was also blended with Poly(L-lactic acid), referred to as PLLA in PHB/PLLA ratios of 100/0, 75/25, 50/50, 25/75 and 0/100, to determine the effect of blending on the thermal stability of PHB. Again, thermal stability was determined by monitoring torque during compounding and by measuring complex viscosity through parallel-plate rheology. Blends in which PHB was the more abundant phase, as well as the 50% PHB/50% PLA

  19. 77 FR 6587 - PHB Die Casting a Subsidiary of PHB, Inc., Including On-Site Leased Workers From Career Concepts...

    Science.gov (United States)

    2012-02-08

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-64,292] PHB Die Casting a... 19, 2008, applicable to workers of PHB Die Casting, a subsidiary of PHB, Inc., including on-site... production of die castings. New information shows that a worker from Burns Industrial Group (BIG Inc) was...

  20. Cyanobacterial Polyhydroxybutyrate (PHB: Screening, Optimization and Characterization.

    Directory of Open Access Journals (Sweden)

    Sabbir Ansari

    Full Text Available In modern life petroleum-based plastic has become indispensable due to its frequent use as an easily available and a low cost packaging and moulding material. However, its rapidly growing use is causing aquatic and terrestrial pollution. Under these circumstances, research and development for biodegradable plastic (bioplastics is inevitable. Polyhydroxybutyrate (PHB, a type of microbial polyester that accumulates as a carbon/energy storage material in various microorganisms can be a good alternative. In this study, 23 cyanobacterial strains (15 heterocystous and 8 non-heterocystous were screened for PHB production. The highest PHB (6.44% w/w of dry cells was detected in Nostoc muscorum NCCU- 442 and the lowest in Spirulina platensis NCCU-S5 (0.51% w/w of dry cells, whereas no PHB was found in Cylindrospermum sp., Oscillatoria sp. and Plectonema sp. Presence of PHB granules in Nostoc muscorum NCCU- 442 was confirmed microscopically with Sudan black B and Nile red A staining. Pretreatment of biomass with methanol: acetone: water: dimethylformamide [40: 40: 18: 2 (MAD-I] with 2 h magnetic bar stirring followed by 30 h continuous chloroform soxhlet extraction acted as optimal extraction conditions. Optimized physicochemical conditions viz. 7.5 pH, 30°C temperature, 10:14 h light:dark periods with 0.4% glucose (as additional carbon source, 1.0 gl-1 sodium chloride and phosphorus deficiency yielded 26.37% PHB on 7th day instead of 21st day. Using FTIR, 1H NMR and GC-MS, extracted polymer was identified as PHB. Thermal properties (melting temperature, decomposition temperatures etc. of the extracted polymer were determined by TGA and DSC. Further, the polymer showed good tensile strength and young's modulus with a low extension to break ratio comparable to petrochemical plastic. Biodegradability potential tested as weight loss percentage showed efficient degradation (24.58% of PHB within 60 days by mixed microbial culture in comparison to

  1. Cyanobacterial Polyhydroxybutyrate (PHB): Screening, Optimization and Characterization

    Science.gov (United States)

    Ansari, Sabbir; Fatma, Tasneem

    2016-01-01

    In modern life petroleum-based plastic has become indispensable due to its frequent use as an easily available and a low cost packaging and moulding material. However, its rapidly growing use is causing aquatic and terrestrial pollution. Under these circumstances, research and development for biodegradable plastic (bioplastics) is inevitable. Polyhydroxybutyrate (PHB), a type of microbial polyester that accumulates as a carbon/energy storage material in various microorganisms can be a good alternative. In this study, 23 cyanobacterial strains (15 heterocystous and 8 non-heterocystous) were screened for PHB production. The highest PHB (6.44% w/w of dry cells) was detected in Nostoc muscorum NCCU- 442 and the lowest in Spirulina platensis NCCU-S5 (0.51% w/w of dry cells), whereas no PHB was found in Cylindrospermum sp., Oscillatoria sp. and Plectonema sp. Presence of PHB granules in Nostoc muscorum NCCU- 442 was confirmed microscopically with Sudan black B and Nile red A staining. Pretreatment of biomass with methanol: acetone: water: dimethylformamide [40: 40: 18: 2 (MAD-I)] with 2 h magnetic bar stirring followed by 30 h continuous chloroform soxhlet extraction acted as optimal extraction conditions. Optimized physicochemical conditions viz. 7.5 pH, 30°C temperature, 10:14 h light:dark periods with 0.4% glucose (as additional carbon source), 1.0 gl-1 sodium chloride and phosphorus deficiency yielded 26.37% PHB on 7th day instead of 21st day. Using FTIR, 1H NMR and GC-MS, extracted polymer was identified as PHB. Thermal properties (melting temperature, decomposition temperatures etc.) of the extracted polymer were determined by TGA and DSC. Further, the polymer showed good tensile strength and young’s modulus with a low extension to break ratio comparable to petrochemical plastic. Biodegradability potential tested as weight loss percentage showed efficient degradation (24.58%) of PHB within 60 days by mixed microbial culture in comparison to petrochemical plastic

  2. Isolated Poly(3-Hydroxybutyrate) (PHB) Granules Are Complex Bacterial Organelles Catalyzing Formation of PHB from Acetyl Coenzyme A (CoA) and Degradation of PHB to Acetyl-CoA▿

    OpenAIRE

    Uchino, Keiichi; Saito, Terumi; Gebauer, Birgit; Jendrossek, Dieter

    2007-01-01

    Poly(3-hydroxybutyrate) (PHB) granules isolated in native form (nPHB granules) from Ralstonia eutropha catalyzed formation of PHB from 14C-labeled acetyl coenzyme A (CoA) in the presence of NADPH and concomitantly released CoA, revealing that PHB biosynthetic proteins (acetoacetyl-CoA thiolase, acetoacetyl-CoA reductase, and PHB synthase) are present and active in isolated nPHB granules in vitro. nPHB granules also catalyzed thiolytic cleavage of PHB in the presence of added CoA, resulting in...

  3. Novel extracellular PHB depolymerase from Streptomyces ascomycinicus: PHB copolymers degradation in acidic conditions.

    Directory of Open Access Journals (Sweden)

    Javier García-Hidalgo

    Full Text Available The ascomycin-producer strain Streptomyces ascomycinicus has been proven to be an extracellular poly(R-3-hydroxybutyrate (PHB degrader. The fkbU gene, encoding a PHB depolymerase (PhaZ Sa , has been cloned in E. coli and Rhodococcus sp. T104 strains for gene expression. Gram-positive host Rhodococcus sp. T104 was able to produce and secrete to the extracellular medium an active protein form. PhaZ Sa was purified by two hydrophobic interaction chromatographic steps, and afterwards was biochemically as well as structurally characterized. The enzyme was found to be a monomer with a molecular mass of 48.4 kDa, and displayed highest activity at 45°C and pH 6, thus being the first PHB depolymerase from a gram-positive bacterium presenting an acidic pH optimum. The PHB depolymerase activity of PhaZ Sa was increased in the presence of divalent cations due to non-essential activation, and also in the presence of methyl-β-cyclodextrin and PEG 3350. Protein structure was analyzed, revealing a globular shape with an alpha-beta hydrolase fold. The amino acids comprising the catalytic triad, Ser(131-Asp(209-His(269, were identified by multiple sequence alignment, chemical modification of amino acids and site-directed mutagenesis. These structural results supported the proposal of a three-dimensional model for this depolymerase. PhaZ Sa was able to degrade PHB, but also demonstrated its ability to degrade films made of PHB, PHBV copolymers and a blend of PHB and starch (7∶3 proportion wt/wt. The features shown by PhaZ Sa make it an interesting candidate for industrial applications involving PHB degradation.

  4. Novel extracellular PHB depolymerase from Streptomyces ascomycinicus: PHB copolymers degradation in acidic conditions.

    Science.gov (United States)

    García-Hidalgo, Javier; Hormigo, Daniel; Arroyo, Miguel; de la Mata, Isabel

    2013-01-01

    The ascomycin-producer strain Streptomyces ascomycinicus has been proven to be an extracellular poly(R)-3-hydroxybutyrate (PHB) degrader. The fkbU gene, encoding a PHB depolymerase (PhaZ Sa ), has been cloned in E. coli and Rhodococcus sp. T104 strains for gene expression. Gram-positive host Rhodococcus sp. T104 was able to produce and secrete to the extracellular medium an active protein form. PhaZ Sa was purified by two hydrophobic interaction chromatographic steps, and afterwards was biochemically as well as structurally characterized. The enzyme was found to be a monomer with a molecular mass of 48.4 kDa, and displayed highest activity at 45°C and pH 6, thus being the first PHB depolymerase from a gram-positive bacterium presenting an acidic pH optimum. The PHB depolymerase activity of PhaZ Sa was increased in the presence of divalent cations due to non-essential activation, and also in the presence of methyl-β-cyclodextrin and PEG 3350. Protein structure was analyzed, revealing a globular shape with an alpha-beta hydrolase fold. The amino acids comprising the catalytic triad, Ser(131)-Asp(209)-His(269), were identified by multiple sequence alignment, chemical modification of amino acids and site-directed mutagenesis. These structural results supported the proposal of a three-dimensional model for this depolymerase. PhaZ Sa was able to degrade PHB, but also demonstrated its ability to degrade films made of PHB, PHBV copolymers and a blend of PHB and starch (7∶3 proportion wt/wt). The features shown by PhaZ Sa make it an interesting candidate for industrial applications involving PHB degradation.

  5. Impact of Ralstonia eutropha's poly(3-Hydroxybutyrate) (PHB) Depolymerases and Phasins on PHB storage in recombinant Escherichia coli.

    Science.gov (United States)

    Eggers, Jessica; Steinbüchel, Alexander

    2014-12-01

    The model organism for polyhydroxybutyrate (PHB) biosynthesis, Ralstonia eutropha H16, possesses multiple isoenzymes of granules coating phasins as well as of PHB depolymerases, which degrade accumulated PHB under conditions of carbon limitation. In this study, recombinant Escherichia coli BL21(DE3) strains were used to study the impact of selected PHB depolymerases of R. eutropha H16 on the growth behavior and on the amount of accumulated PHB in the absence or presence of phasins. For this purpose, 20 recombinant E. coli BL21(DE3) strains were constructed, which harbored a plasmid carrying the phaCAB operon from R. eutropha H16 to ensure PHB synthesis and a second plasmid carrying different combinations of the genes encoding a phasin and a PHB depolymerase from R. eutropha H16. It is shown in this study that the growth behavior of the respective recombinant E. coli strains was barely affected by the overexpression of the phasin and PHB depolymerase genes. However, the impact on the PHB contents was significantly greater. The strains expressing the genes of the PHB depolymerases PhaZ1, PhaZ2, PhaZ3, and PhaZ7 showed 35% to 94% lower PHB contents after 30 h of cultivation than the control strain. The strain harboring phaZ7 reached by far the lowest content of accumulated PHB (only 2.0% [wt/wt] PHB of cell dry weight). Furthermore, coexpression of phasins in addition to the PHB depolymerases influenced the amount of PHB stored in cells of the respective strains. It was shown that the phasins PhaP1, PhaP2, and PhaP4 are not substitutable without an impact on the amount of stored PHB. In particular, the phasins PhaP2 and PhaP4 seemed to limit the degradation of PHB by the PHB depolymerases PhaZ2, PhaZ3, and PhaZ7, whereas almost no influence of the different phasins was observed if phaZ1 was coexpressed. This study represents an extensive analysis of the impact of PHB depolymerases and phasins on PHB accumulation and provides a deeper insight into the complex interplay

  6. A closer look on the polyhydroxybutyrate- (PHB-) negative phenotype of Ralstonia eutropha PHB-4.

    Science.gov (United States)

    Raberg, Matthias; Voigt, Birgit; Hecker, Michael; Steinbüchel, Alexander

    2014-01-01

    The undefined poly(3-hydroxybutyrate)- (PHB-) negative mutant R. eutropha PHB-4 was generated in 1970 by 1-nitroso-3-nitro-1-methylguanidine (NMG) treatment. Although being scientific relevant, its genotype remained unknown since its isolation except a recent first investigation. In this study, the mutation causing the PHA-negative phenotype of R. eutropha PHB-4 was confirmed independently: sequence analysis of the phaCAB operon identified a G320A mutation in phaC yielding a stop codon, leading to a massively truncated PhaC protein of 106 amino acids (AS) in R. eutropha PHB-4 instead of 589 AS in the wild type. No other mutations were observed within the phaCAB operon. As further mutations probably occurred in the genome of mutant PHB-4 potentially causing secondary effects on the cells' metabolism, the main focus of the study was to perform a 2D PAGE-based proteome analysis in order to identify differences in the proteomes of the wild type and mutant PHB-4. A total of 20 differentially expressed proteins were identified which provide valuable insights in the metabolomic changes of mutant PHB-4. Besides excretion of pyruvate, mutant PHB-4 encounters the accumulation of intermediates such as pyruvate and acetyl-CoA by enhanced expression of the observed protein species: (i) ThiJ supports biosynthesis of cofactor TPP and thereby reinforces the 2-oxoacid dehydrogenase complexes as PDHC, ADHC and OGDHC in order to convert pyruvate at a higher rate and the (ii) 3-isopropylmalate dehydrogenase LeuB3 apparently directs pyruvate to synthesis of several amino acids. Different (iii) acylCoA-transferases enable transfer reactions between organic acid intermediates, and (iv) citrate lyase CitE4 regenerates oxaloacetate from citrate for conversion with acetyl-CoA in the TCC in an anaplerotic reaction. Substantial amounts of reduction equivalents generated in the TCC are countered by (v) synthesis of more ubiquinones due to enhanced synthesis of MenG2 and MenG3, thereby

  7. Identification of a multifunctional protein, PhaM, that determines number, surface to volume ratio, subcellular localization and distribution to daughter cells of poly(3-hydroxybutyrate), PHB, granules in Ralstonia eutropha H16.

    Science.gov (United States)

    Pfeiffer, Daniel; Wahl, Andreas; Jendrossek, Dieter

    2011-11-01

    A two-hybrid approach was applied to screen for proteins with the ability to interact with PHB synthase (PhaC1) of Ralstonia eutropha. The H16_A0141 gene (phaM) was identified in the majority of positive clones. PhaM (26.6 kDa) strongly interacted with PhaC1 and with phasin PhaP5 but not with PhaP1 or other PHB granule-associated proteins. A ΔphaM mutant accumulated only one or two large PHB granules instead of three to six medium-sized PHB granules of the wild type, and distribution of granules to daughter cells was disordered. All three phenotypes (number, size and distribution of PHB granules) were reversed by reintroduction of phaM. Purified PhaM revealed DNA-binding properties in gel mobility shift experiments. Expression of a fusion of the yellow fluorescent protein (eYfp) with PhaM resulted in formation of many small fluorescent granules that were bound to the nucleoid region. Remarkably, an eYfp-PhaP5 fusion localized at the cell poles in a PHB-negative background and overexpression of eYfp-PhaP5 in the wild type conferred binding of PHB granules to the cell poles. In conclusion, subcellular localization of PHB granules in R. eutropha depends on a concerted expression of at least three PHB granule-associated proteins, namely PhaM, PhaP5 and PHB synthase PhaC1. © 2011 Blackwell Publishing Ltd.

  8. Nanocomposite microcapsules from powders of polyhydroxybutyrate (PHB) and smectite clays

    International Nuclear Information System (INIS)

    Silva-Valenzuela, Maria das Gracas da; Wang, Shu Hui; Wiebeck, Helio; Valenzuela-Diaz, Francisco R.

    2009-01-01

    Drug delivery systems involving microcapsules provide an attractive way to improve the performance of many chemical and biological substances. These systems may be used for several industrial segments, especially medical, pharmaceuticals and cosmetics. PHB is a polyhydroxyalkanoate available in powder form, biocompatible, biodegradable and inert towards animal tissues. The obtained PHB/smectite clay nanocomposite improved the physical-chemical properties of PHB, including its biodegradability. In this work, we describe the preparation of microcapsules from two nanocomposites systems: a) PHB and Cloisite 20A organoclay (PHB1) and b) PHB and natural Brazilian green polycationic clay (PHB2). When analyzed by XRD, the films and microcapsules did not show a d (001) peak, demonstrating an exfoliated structure for the nanocomposites. The films have shown by SEM an homogeneous distribution with the clay mineral particles spread homogeneously by the PHB film. The new microcapsules/nanocomposites showed an 'hydrangea' morphology. The diameter of the microcapsules was variable between 0.5-15 μm. (author)

  9. Effects of Mutations in the Substrate-Binding Domain of Poly[(R)-3-Hydroxybutyrate] (PHB) Depolymerase from Ralstonia pickettii T1 on PHB Degradation▿

    OpenAIRE

    Hiraishi, Tomohiro; Hirahara, Yoko; Doi, Yoshiharu; Maeda, Mizuo; Taguchi, Seiichi

    2006-01-01

    Poly[(R)-3-hydroxybutyrate] (PHB) depolymerase from Ralstonia pickettii T1 (PhaZRpiT1) adsorbs to denatured PHB (dPHB) via its substrate-binding domain (SBD) to enhance dPHB degradation. To evaluate the amino acid residues participating in dPHB adsorption, PhaZRpiT1 was subjected to a high-throughput screening system consisting of PCR-mediated random mutagenesis targeted to the SBD gene and a plate assay to estimate the effects of mutations in the SBD on dPHB degradation by PhaZRpiT1. Genetic...

  10. Optimizing PHB and Protease Production by Box Behnken Design

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    Amro Abd al fattah Amara

    2013-04-01

    Full Text Available Mixed culture is more suitable to adapt more flexible fermentation process and produce different product simultaneously. In this study a mixed Bacillus culture was investigated for their ability to produce the bioplastic "Polyhydroxybutyrate" and both of the mesophilic and the thermophilic proteases in one flask. Box-Behnken experimental design was used. The produced amount of PHB has been increased significantly. Meanwhile there is a competition between PHB and proteases. The maximum produced amount of PHB using Box-Behnken design was 2.82 g/l/48 h with protease activity equal to 41.9 Units/ml/48 h for thermophilic proteases and 99.65 Units/ml/48 h for mesophilic proteases. Excel solver was used for extra-optimization for the optimum conditions obtained from Box-Behnken experiments and its model. The maximum PHB obtained after using Excel solver was 2.88 g/l/48 h. The maximum mesophilic and thermophilic activities obtained at the same PHB production conditions were 175.68 and 243.38 Units/ml respectively. The model accuracy as obtained from Excel solver was 118.8%, which prove the power of the experimental design in optimizing such complicated process. The strategies used in this study are recommended for the production of PHB and different proteases simultaneously using Bacillus mixed culture. ABSTRAK: Kultur campuran adalah lebih sesuai bagi proses penapaian yang fleksibel dan ia boleh menghasilkan produk yang berbeza secara serentak. Dalam kajian ini keupayaan  menghasilkan "Polyhydroxybutyrate" bioplastik serta mesofilik dan termofilik protease dalam satu flask oleh  kultur Bacillus campuran telah disiasat. Eksperimen rekabentuk Box-Behnken telah digunakan. Jumlah PHB yang dikeluarkan meningkat dengan ketara dan terdapat persaingan antara PHB dan protease. Jumlah keluaran PHB maksima menggunakan rekabentuk Box-Behnken adalah 2.82 g/l/48 jam dengan aktiviti protease sama dengan 41.9 Unit/ml/48 jam untuk protease termofilik dan 99.65 Unit

  11. Response coefficient analysis of a fed-batch bioreactor to dissolved oxygen perturbation in complementary cultures during PHB production

    Directory of Open Access Journals (Sweden)

    Patnaik Pratap R

    2008-03-01

    Full Text Available Abstract Background Although the production of poly-β-hydroxybutyrate (PHB has many biological, energetic and environmental advantages over chemically synthesized polymers, synthetic polymers continue to be produced industrially since the productivities of fermentation processes fr PHB are not yet economically competitive. Improvement of a PHB fermentation requires good understanding and optimization under the realistic conditions of large bioreactors. Laboratory-scale studies have shown that co-cultures of Ralstonia eutropha and Lactobacillus delbrueckii generate better fermentation efficiencies than R. eutropha alone. In large bioreactors, incomplete dispersioin and perturbations in the dissolved oxygen (DO concentration, both of which affect the fermentation, have to be considered. This study analyzes the effect of DO fluctuations on bioreactor performance for both ideal and optimally dispersed broths. Results Response coefficient analysis was employed to obtain quantitative information on the effect of DO perturbations on different variables. Three values of the Peclet number (Pe cheracterized three levels of dispersion: Pe = 0.01 for nearly complete dispersion, Pe = 20 for optimum dispersion and Pe = 60 for insufficient dispersion. The response coefficients (RCs of the pairs of bacterial concentrations and the main substrates, glucose and ammonium chloride, showed contrasting variations with time. Lactate, a critical intermediate, and PHB had similar RC profiles but those of lactate were one to two orders of magnitude larger than other RCs. Significantly, the optimum Pe also resulted in the largest RCs, suggesting a balance between productivity and reactor stability. Conclusion Since R. eutropha requires oxygen for its growth whereas L. delbrueckii does not, fluctuations in the DO concentartion have a strong influence on the fermentation. Apart from this, the mechanism of PHB biosynthesis indicates that control of lactate is a critical

  12. Antibacterial properties of modified biodegradable PHB non-woven fabric.

    Science.gov (United States)

    Slepička, P; Malá, Z; Rimpelová, S; Švorčík, V

    2016-08-01

    The antibacterial properties of poly(hydroxybutyrate) (PHB) non-woven fabric were explored in this study. The PHB was activated by plasma modification and subsequently processed with either immersion into a solution of nanoparticles or direct metallization. The wettability and surface chemistry of the PHB surface was determined. The thickness of the sputtered nanolayer on PHB fabric was characterized. It was found that plasma modification led to a formation of strongly hydrophilic surface, while the subsequent metallization by silver or gold resulted in a significantly increased water contact angle. Further, it was found that antibacterial activity may be controlled by the type of a metal and deposition method used. The immersion of plasma modified fabric into Ag nanoparticle solution led to enhanced antibacterial efficiency of PHB against Escherichia coli (E. coli). Direct silver sputtering on PHB fabric was proved to be a simple method for construction of a surface with strong antibacterial potency against both Escherichia coli (E. coli) and Staphylococcus epidermidis (S. epidermidis). We demonstrated the antibacterial activity of PHB fabric modified by plasma activation and consecutive selection of a treatment method for an effective antibacterial surface construction. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Expression of the Azotobacter vinelandii Poly-β-Hydroxybutyrate Biosynthetic phbBAC Operon Is Driven by Two Overlapping Promoters and Is Dependent on the Transcriptional Activator PhbR

    OpenAIRE

    Peralta-Gil, Martín; Segura, Daniel; Guzmán, Josefina; Servín-González, Luis; Espín, Guadalupe

    2002-01-01

    The Azotobacter vinelandii phbBAC genes encode the enzymes for poly-β-hydroxybutyrate (PHB) synthesis. The phbR gene, which is located upstream of and in the opposite direction of phbBAC, encodes PhbR, a transcriptional activator which is a member of the AraC family of activators. Here we report that a mutation in phbR reduced PHB accumulation and transcription of a phbB-lacZ fusion. We also report that phbB is transcribed from two overlapping promoters, pB1 and pB2. The region corresponding ...

  14. PHB in Cardiovascular and Other Diseases: Present Knowledge and Implications.

    Science.gov (United States)

    Chowdhury, Debabrata; Kumar, Dinesh; Sarma, Pranjal; Tangutur, Anjana Devi; Bhadra, Manika Pal

    2017-11-30

    Prohibitin (PHB) is overtly conserved evolutionarily and ubiquitously expressed protein with pleiotropic functions in diverse cellular compartments. However, regulation and function of these proteins in different cells, tissues and in various diseases is different as evidenced by expression of these proteins which is found to be reduced in heart diseases, kidney diseases, lung disease, Crohn's disease and ulcerative colitis but this protein is highly expressed in diverse cancers. The mechanism by which this protein acts at the molecular level in different subcellular localizations or in different cells or tissues in different conditions (diseases or normal) has remained poorly understood. There are several studies reported to understand and decipher PHB's role in diseases and/or cancers of ovary, lung, stomach, thyroid, liver, blood, prostrate, gastric, esophagus, glioma, breast, bladder etc. where PHB is shown to act through mechanisms by acting as oncogene, tumor suppressor, antioxidant, antiapoptotic, in angiogenesis, autophagy etc. This review specifically gives attention to the functional role and regulatory mechanism of PHB proteins in cardiovascular health and diseases and its associated implications. Various molecular pathways involved in PHB function and its regulation are analyzed. PHB is rapidly emerging as a critical target molecule for cardiovascular signaling. Progress in delineating CVD and mechanisms of PHB in diverse molecular pathways is essential for determining when and how PHB targeted therapy might be feasible. In this regard, new therapies targeting PHB may best be applied in the future together with molecular profiling of CVD for clinical stratification of disease diagnosis and prognosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Development of eco-friendly bioplastic like PHB by distillery effluent microorganisms.

    Science.gov (United States)

    Gangurde, Nilesh S; Sayyed, Riyaz Z; Kiran, Shashi; Gulati, Arvind

    2013-01-01

    During screening for poly-β-hydroxybutyrate (PHB) producing bacteria from distillery effluent sample, six out of 30 isolates comprising of three strains of Alcaligenes sp., two strains of Bacillus sp., and one strain of Pseudomonas sp. were found to accumulate varying levels of intracellular PHB. Amongst the various isolates, Alcaligenes sp. RZS4 was found as the potent PHB-producing organism, accumulating higher amounts of PHB. PHB productivity was further enhanced in the presence of oxygen, nitrogen-limiting conditions, and cloning of PHB synthesizing genes of Alcaligenes sp. RZS 4 into Escherichia coli. A twofold increase in PHB yield was obtained from recombinant E. coli vis-à-vis Alcaligenes sp.; the recombinant E. coli accumulated more PHB in NDMM, produced good amount of PHB in a single-stage cultivation process under both nutrient-rich and nutrient-deficient conditions. Extraction of PHB with acetone-alcohol (1:1) was found as suitable method for optimum extraction of PHB as this mixture selectively extracted PHB without affecting the non-PHB cell mass. PHB extract from recombinant E. coli showed the presence of C-H, =O stretching, =C-H deformation, =C-H, =CH, and =C-O functional groups characteristic of PHB.

  16. Identification and characterization of PhbF: a DNA binding protein with regulatory role in the PHB metabolism of Herbaspirillum seropedicae SmR1.

    Science.gov (United States)

    Kadowaki, Marco A S; Müller-Santos, Marcelo; Rego, Fabiane G M; Souza, Emanuel M; Yates, Marshall G; Monteiro, Rose A; Pedrosa, Fabio O; Chubatsu, Leda S; Steffens, Maria B R

    2011-10-14

    Herbaspirillum seropedicae SmR1 is a nitrogen fixing endophyte associated with important agricultural crops. It produces polyhydroxybutyrate (PHB) which is stored intracellularly as granules. However, PHB metabolism and regulatory control is not yet well studied in this organism. In this work we describe the characterization of the PhbF protein from H. seropedicae SmR1 which was purified and characterized after expression in E. coli. The purified PhbF protein was able to bind to eleven putative promoters of genes involved in PHB metabolism in H. seropedicae SmR1. In silico analyses indicated a probable DNA-binding sequence which was shown to be protected in DNA footprinting assays using purified PhbF. Analyses using lacZ fusions showed that PhbF can act as a repressor protein controlling the expression of PHB metabolism-related genes. Our results indicate that H. seropedicae SmR1 PhbF regulates expression of phb-related genes by acting as a transcriptional repressor. The knowledge of the PHB metabolism of this plant-associated bacterium may contribute to the understanding of the plant-colonizing process and the organism's resistance and survival in planta.

  17. Identification and characterization of PhbF: A DNA binding protein with regulatory role in the PHB metabolism of Herbaspirillum seropedicae SmR1

    Directory of Open Access Journals (Sweden)

    Pedrosa Fabio O

    2011-10-01

    Full Text Available Abstract Background Herbaspirillum seropedicae SmR1 is a nitrogen fixing endophyte associated with important agricultural crops. It produces polyhydroxybutyrate (PHB which is stored intracellularly as granules. However, PHB metabolism and regulatory control is not yet well studied in this organism. Results In this work we describe the characterization of the PhbF protein from H. seropedicae SmR1 which was purified and characterized after expression in E. coli. The purified PhbF protein was able to bind to eleven putative promoters of genes involved in PHB metabolism in H. seropedicae SmR1. In silico analyses indicated a probable DNA-binding sequence which was shown to be protected in DNA footprinting assays using purified PhbF. Analyses using lacZ fusions showed that PhbF can act as a repressor protein controlling the expression of PHB metabolism-related genes. Conclusions Our results indicate that H. seropedicae SmR1 PhbF regulates expression of phb-related genes by acting as a transcriptional repressor. The knowledge of the PHB metabolism of this plant-associated bacterium may contribute to the understanding of the plant-colonizing process and the organism's resistance and survival in planta.

  18. Comparative genome analysis of PHB gene family reveals deep evolutionary origins and diverse gene function.

    Science.gov (United States)

    Di, Chao; Xu, Wenying; Su, Zhen; Yuan, Joshua S

    2010-10-07

    PHB (Prohibitin) gene family is involved in a variety of functions important for different biological processes. PHB genes are ubiquitously present in divergent species from prokaryotes to eukaryotes. Human PHB genes have been found to be associated with various diseases. Recent studies by our group and others have shown diverse function of PHB genes in plants for development, senescence, defence, and others. Despite the importance of the PHB gene family, no comprehensive gene family analysis has been carried to evaluate the relatedness of PHB genes across different species. In order to better guide the gene function analysis and understand the evolution of the PHB gene family, we therefore carried out the comparative genome analysis of the PHB genes across different kingdoms. The relatedness, motif distribution, and intron/exon distribution all indicated that PHB genes is a relatively conserved gene family. The PHB genes can be classified into 5 classes and each class have a very deep evolutionary origin. The PHB genes within the class maintained the same motif patterns during the evolution. With Arabidopsis as the model species, we found that PHB gene intron/exon structure and domains are also conserved during the evolution. Despite being a conserved gene family, various gene duplication events led to the expansion of the PHB genes. Both segmental and tandem gene duplication were involved in Arabidopsis PHB gene family expansion. However, segmental duplication is predominant in Arabidopsis. Moreover, most of the duplicated genes experienced neofunctionalization. The results highlighted that PHB genes might be involved in important functions so that the duplicated genes are under the evolutionary pressure to derive new function. PHB gene family is a conserved gene family and accounts for diverse but important biological functions based on the similar molecular mechanisms. The highly diverse biological function indicated that more research needs to be carried out

  19. Understanding the physiological roles of polyhydroxybutyrate (PHB) in Rhodospirillum rubrum S1 under aerobic chemoheterotrophic conditions.

    Science.gov (United States)

    Narancic, Tanja; Scollica, Elisa; Kenny, Shane T; Gibbons, Helena; Carr, Eibhlin; Brennan, Lorraine; Cagney, Gerard; Wynne, Kieran; Murphy, Cormac; Raberg, Matthias; Heinrich, Daniel; Steinbüchel, Alexander; O'Connor, Kevin E

    2016-10-01

    Polyhydroxybutyrate (PHB) is an important biopolymer accumulated by bacteria and associated with cell survival and stress response. Here, we make two surprising findings in the PHB-accumulating species Rhodospirillum rubrum S1. We first show that the presence of PHB promotes the increased assimilation of acetate preferentially into biomass rather than PHB. When R. rubrum is supplied with (13)C-acetate as a PHB precursor, 83.5 % of the carbon in PHB comes from acetate. However, only 15 % of the acetate ends up in PHB with the remainder assimilated as bacterial biomass. The PHB-negative mutant of R. rubrum assimilates 2-fold less acetate into biomass compared to the wild-type strain. Acetate assimilation proceeds via the ethylmalonyl-CoA pathway with (R)-3-hydroxybutyrate as a common intermediate with the PHB pathway. Secondly, we show that R. rubrum cells accumulating PHB have reduced ribulose 1,5-bisphosphate carboxylase (RuBisCO) activity. RuBisCO activity reduces 5-fold over a 36-h period after the onset of PHB. In contrast, a PHB-negative mutant maintains the same level of RuBisCO activity over the growth period. Since RuBisCO controls the redox potential in R. rubrum, PHB likely replaces RuBisCO in this role. R. rubrum is the first bacterium found to express RuBisCO under aerobic chemoheterotrophic conditions.

  20. PHB granules are attached to the nucleoid via PhaM in Ralstonia eutropha.

    Science.gov (United States)

    Wahl, Andreas; Schuth, Nora; Pfeiffer, Daniel; Nussberger, Stephan; Jendrossek, Dieter

    2012-11-16

    Poly(3-hydroxybutyrate) (PHB) granules are important storage compounds of carbon and energy in many prokaryotes which allow survival of the cells in the absence of suitable carbon sources. Formation and subcellular localization of PHB granules was previously assumed to occur randomly in the cytoplasm of PHB accumulating bacteria. However, contradictionary results on subcellular localization of PHB granules in Ralstonia eutropha were published, recently. Here, we provide evidence by transmission electron microscopy that PHB granules are localized in close contact to the nucleoid region in R. eutropha during growth on nutrient broth. Binding of PHB granules to the nucleoid is mediated by PhaM, a PHB granule associated protein with phasin-like properties that is also able to bind to DNA and to phasin PhaP5. Over-expression of PhaM resulted in formation of many small PHB granules that were always attached to the nucleoid region. In contrast, PHB granules of ∆phaM strains became very large and distribution of granules to daughter cells was impaired. Association of PHB granules to the nucleoid region was prevented by over-expression of PhaP5 and clusters of several PHB granules were mainly localized near the cell poles. Subcellular localization of PHB granules is controlled in R. eutropha and depends on the presence and concentrations of at least two PHB granule associated proteins, PhaM and PhaP5.

  1. Poly(-β-hydroxybutyrate) (PHB) depolymerase PHAZ Pen from Penicillium expansum: purification, characterization and kinetic studies.

    Science.gov (United States)

    Gowda U S, Vaishnavi; Shivakumar, Srividya

    2015-12-01

    Very few studies have been dedicated to R-hydroxyacids (R-HA) production using extracellular polyhydroxyalkanoate depolymerases (ePhaZs). Penicillium expansum produced maximum extracellular polyhydroxybutyrate depolymerase (~6 U/mL) by 72 h when grown in mineral salt medium containing 0.2 % w/v PHB, pH 5.0, at 30 °C and 200 rpm shaking conditions. Partial purification of the extracellular poly(-β-hydroxybutyrate) depolymerase PHAZ Pen from P. expansum by two steps using ammonium sulphate (80 % saturation) and affinity chromatography using concanavalin A yielded 22.76-fold purity and 43.15 % recovery of protein. The enzyme composed of a single polypeptide chain of apparent molecular mass of 20 kDa, as determined by SDS-PAGE, stained positive for glycoprotein by periodic-schiff base (PAS) staining. Optimum enzyme activity was detected between pH 4.0 and 6.0 at 45-50 °C with pH 5.0 and 50 °C supporting maximum activity. The enzyme was stable between pH 4.0 and 6.0 at 55 °C for 1 h with a residual activity of almost 70-80 %. The enzyme was completely inhibited by 1 mM DTT/1 mM HgCl 2 and N-ethylmaleimide (10 mM) indicating the importance of essential disulphide bonds (cystine residues) and tyrosine for enzyme activity or probably for maintaining the native enzyme structure. Among the various divalent and trivalent metal ions, mercuric chloride, ferric citrate and ferrous sulphate inhibited enzyme activity. The enzyme showed substrate specificity towards only PHB and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and no other lipid or other p-nitrophenyl fatty acids or with polycaprolactone, showing that it was a true depolymerase and not any lipase or cutinase. Preliminary investigation revealed β-hydroxybutyrate as the end product of PHB hydrolysis by P. expansum, suggesting that the enzyme acted principally as an exo-type hydrolase. The above properties when compared with other fungal PHB depolymerases reported till date suggest the distinct nature

  2. The expression pattern and potential functions of PHB in the spermiogenesis of Phascolosoma esculenta.

    Science.gov (United States)

    Hou, Cong-Cong; Gao, Xin-Ming; Ni, Jie; Mu, Dan-Li; Yang, Hai-Yan; Liu, Cheng; Zhu, Jun-Quan

    2018-04-30

    Prohibitin (PHB) is a ubiquitous, evolutionarily conserved protein that is mainly localized in the inner mitochondrial membrane and exerts various mitochondrial functions. Here, we first cloned the phb gene from P. esculenta. The Pe-PHB protein has high homology and a similar protein structure to that of other animals, and it can be divided into the N-terminal hydrophobic/transmembrane domain, SPFH domain, and C-terminal coiled-coil domain. The Pe-phb gene is widely expressed, and the gene expression of phb is highest in coelomic fluid where spermiogenesis occurs, indicating a specific function in the coelom. We further observed continuous expression of the phb gene and localization of PHB proteins in mitochondria during spermiogenesis, indicating that PHB, as a mitochondrial component, may play a role during this process via its mitochondrial function. In addition, ubiquitination of mitochondria was detected, and the PHB signal was co-localized with the poly-ubiquitin signal during spermiogenesis. Mature sperm also showed ubiquitination of mitochondria and PHB. Therefore, PHB may be a substrate of poly-ubiquitin to regulate the ubiquitination of mitochondria and even subsequent elimination during P. esculenta spermiogenesis, and it has a potential role in guaranteeing the maternal inheritance of mitochondria. Taken together, these results support the hypothesis that PHB participates in the spermiogenesis of P. esculenta by maintaining the normal function of mitochondria and regulating the degradation of mitochondria. Copyright © 2018. Published by Elsevier B.V.

  3. The mitochondrial PHB complex: roles in mitochondrial respiratory complex assembly, ageing and degenerative disease.

    NARCIS (Netherlands)

    Nijtmans, L.G.J.; Artal-Sanz, M.; Grivell, L.A.; Coates, P.J.

    2002-01-01

    Although originally identified as putative negative regulators of the cell cycle, recent studies have demonstrated that the PHB proteins act as a chaperone in the assembly of subunits of mitochondrial respiratory chain complexes. The two PHB proteins, Phblp and Phb2p, are located in the

  4. LDPE/PHB blends filled with castor oil cake

    Science.gov (United States)

    Burlein, Gustavo A.; Rocha, Marisa C. G.

    2015-05-01

    The response surface methodology (RSM) is a collection of mathematical techniques useful for developing, improving and optimizing process. In this study, RSM technique was applied to evaluate the effect of the components proportion on the mechanical properties of low density polyethylene (LDPE)/ poly (3-hydroxy-butyrate) (PHB) blends filled with castor oil cake (CC). The blends were prepared by melt mixing in a twin screw extruder. Low density polyethylene, poly (3-hydroxy-butyrate) and castor oil pressed cake were represented by the input variables designated as LDPE, PHB and CC, respectively. As it was desirable to consider the largest LDPE content in the ternary system, the components of the mixture were subjected to the following constraints: 0.7 ≤ LDPE ≤ 1.0, 0≤ PHB≤0.3 e 0 ≤ CC ≤0.3. The mechanical properties of the different mixtures were determined by conventional ASTM tests and were evaluated through analysis of variance performed by the Minitab software. Some polynomial equations were tested in order to describe the mechanical behavior of the samples. The quadratic model in pseudo components was selected for describing the tensile behavior because it was the most efficient from a statistical point of view (p-value ≤ 0.05; coefficient of determination (r2) close to 1 and variation inflation factor (VIF) values PHB or CC. The tensile strength values of binary mixtures of LDPE lie in the range from 8.9 to 10 MPa. As some commercial grades of LDPE have mechanical strength in this range, it may be inferred that the addition of a certain amount of PHB or CC to LDPE may be considered as a possibility for obtaining LDPE based materials with increased susceptibility to biodegradation. The cubic model in pseudo components was selected for describe the flexural strength of the samples because it was the most adequate from a statistical point of view. However, the linear model in pseudo components was the most efficient to describe the flexural modulus

  5. Grafting of bacterial polyhydroxybutyrate (PHB) onto cellulose via in situ reactive extrusion with dicumyl peroxide.

    Science.gov (United States)

    Wei, Liqing; McDonald, Armando G; Stark, Nicole M

    2015-03-09

    Polyhydroxybutyrate (PHB) was grafted onto cellulose fiber by dicumyl peroxide (DCP) radical initiation via in situ reactive extrusion. The yield of the grafted (cellulose-g-PHB) copolymer was recorded and grafting efficiency was found to be dependent on the reaction time and DCP concentration. The grafting mechanism was investigated by electron spin resonance (ESR) analysis and showed the presence of radicals produced by DCP radical initiation. The grafted copolymer structure was determined by nuclear magnetic resonance (NMR) spectroscopy. Scanning electronic microscopy (SEM) showed that the cellulose-g-PHB copolymer formed a continuous phase between the surfaces of cellulose and PHB as compared to cellulose-PHB blends. The relative crystallinity of cellulose and PHB were quantified from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) results, while the absolute degree of crystallinity was evaluated by differential scanning calorimetry (DSC). The reduction of crystallinity indicated the grafting reaction occurred not just in the amorphous region but also slightly in crystalline regions of both cellulose and PHB. The smaller crystal sizes suggested the brittleness of PHB was decreased. Thermogravimetric analysis (TGA) showed that the grafted copolymer was stabilized relative to PHB. By varying the reaction parameters the compositions (%PHB and %cellulose) of resultant cellulose-g-PHB copolymer are expected to be manipulated to obtain tunable properties.

  6. Poly-(R)-3-hydroxybutyrates (PHB) are Atherogenic Components of Lipoprotein Lp(a).

    Science.gov (United States)

    Reusch, Rosetta N

    2015-12-01

    The hypothesis is that poly-(R)-3-hydroxybutyrates (PHB), linear polymers of the ketone body, R-3-hydroxybutyrate (R-3HB), are atherogenic components of lipoprotein Lp(a). PHB are universal constituents of biological cells and are thus components of all foods. Medium chain-length PHB (PHB (PHB are highly insoluble in water, but soluble in lipids in which they exhibit a high intrinsic viscosity. They have a higher density than other cellular lipids and they are very adhesive, i.e. they engage in multiple noncovalent interactions with other molecules and salts via hydrogen, hydrophobic and coordinate bonds, thus producing insoluble deposits. Following digestive processes, PHB enter the circulation in chylomicrons and very low density lipoproteins (VLDL). The majority of the PHB (>70%) are absorbed by albumin, which transports them to the liver for disposal. When the amount of PHB in the diet exceed the capacity of albumin to safely remove them from the circulation, the excess PHB remain in the lipid core of LDL particles that become constituents of lipoprotein Lp(a), and contribute to the formation of arterial deposits. In summary, the presence of PHB – water-insoluble, dense, viscous, adhesive polymers – in the lipid cores of the LDL moieties of Lp(a) particles supports the hypothesis that PHB are atherogenic components of Lp(a).

  7. Biochemical characterization of a new type of intracellular PHB depolymerase from Rhodospirillum rubrum with high hydrolytic activity on native PHB granules.

    Science.gov (United States)

    Sznajder, Anna; Jendrossek, Dieter

    2011-03-01

    A Rhodospirillum rubrum gene that is predicted to code for an extracellular poly(3-hydroxybutyrate) (PHB) depolymerase by the recently published polyhydroxyalkanoates (PHA) depolymerase engineering database was cloned. The gene product (PhaZ3( Rru )) was expressed in recombinant E. coli, purified and biochemically characterized. PhaZ3( Rru ) turned out, however, to share characteristics of intracellular PHB depolymerases and revealed a combination of properties that have not yet been described for other PHB depolymerases. A fusion of PhaZ3( Rru )with the enhanced cyan fluorescent protein was able to bind to PHB granules in vivo and supported the function as an intracellular PHB depolymerase. Purified PhaZ3( Rru ) was specific for short-chain-length polyhydroxyalkanoates (PHA(SCL)) and hydrolysed both untreated native PHB granules as well as trypsin-activated native PHB granules to a mixture of mono- and dimeric 3-hydroxybutyrate. Crystalline (denatured) PHB granules were not hydrolysed by PhayZ3( Rru ). Low concentrations of calcium or magnesium ions (1-5 mM) reversibly (EDTA) inhibited the enzyme. Our data suggest that PhaZ3( Rru ) is the representative of a new type of the growing number of intracellular PHB depolymerases.

  8. Valorization of glycerol through the production of biopolymers: the PHB case using Bacillus megaterium.

    Science.gov (United States)

    Naranjo, Javier M; Posada, John A; Higuita, Juan C; Cardona, Carlos A

    2013-04-01

    In this work technical and economic analyses were performed to evaluate the glycerol transformation into Polyhydroxybutyrate using Bacillus megaterium. The production of PHB was compared using glycerol or glucose as substrates and similar yields were obtained. The total production costs for PHB generation with both substrates were estimated at an industrial scale. Compared to glucose, glycerol showed a 10% and 20% decrease in the PHB production costs using two different separation schemes respectively. Moreover, a 20% profit margin in the PHB sales price using glycerol as substrate resulted in a 166% valorization of crude glycerol. In this work, the feasibility of glycerol as feedstock for the production of PHB at laboratory (up to 60% PHB accumulation) and industrial (2.6US$/kgPHB) scales is demonstrated. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Co-Expression of ORFCma with PHB Depolymerase (PhaZCma ) in Escherichia coli Induces Efficient Whole-Cell Biodegradation of Polyesters.

    Science.gov (United States)

    Lee, Ming-Chieh; Liu, En-Jung; Yang, Cheng-Han; Hsiao, Li-Jung; Wu, Tzong-Ming; Li, Si-Yu

    2018-04-01

    Whole-cell degradation of polyesters not only avoids the tedious process of enzyme separation, but also allows the degraded product to be reused as a carbon source. In this study, Escherichia coli BL21(DE3) harboring phaZ Cma , a gene encoding poly(3-hydroxybutyrate) (PHB) depolymerase from Caldimonas manganoxidans, is constructed. The extra-cellular fraction of E. coli/pPHAZ exhibits a fast PHB degradation rate where it only took 35 h to completely degrade PHB films, while C. manganoxidans takes 81 h to do the same. The co-expression of ORF Cma (a putative periplasmic substrate binding protein that is within the same operon of phaZ Cma ) further improves the PHB degradation. While 28 h is needed for E. coli/pPHAZ to cause an 80% weight loss in PHB films, E. coli/pORFPHAZ needs only 21 h. Furthermore, it is able to degrade at-least four different polyesters, PHB, poly(lactic acid) (PLA), polycaprolactone (PCL), and poly(butylene succinate-co-adipate) (PBSA). Testing of the time course of 3-hydroxybutyrate concentration and the turbidity of the degradation solutions over time shows that PhaZ Cma has both exo- and endo-enzymatic activity. The whole-cell E. coli/pORFPHAZ can be used for recycling various polyesters while ORF Cma can potentially be a universal element for enhancing the secretion of recombinant protein. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. PEMODELAN MATEMATIKA PROSES PRODUKSI POLYHYDROXYBUTYRATE (PHB DARI TAPIOKA

    Directory of Open Access Journals (Sweden)

    Margono Margono

    2012-05-01

    Full Text Available MATHEMATICS MODELLING OF POLYHYDROXYBUTYRATE (PHB PRODUCTION FROM TAPIOCA. One of the technical approaches to get improvement of PHB productivity was a process simulation by using mathematical modeling. The objective of this research was to develop mathematical model which could be used to simulate fermentation of polyhydroxybutyrate production by Bacillus cereus IFO 13690 using tapioca substrates. Three different experiments with initial ammonium of 0.286, 0.566, and 1.203 g/L were carried out in 5 L fermentor and 500 rpm of agitation speed. The pH medium was controlled at 5.6 after it came down from the initial pH of 6.8. Meanwhile, the initial doT was 70% air saturation and also came down to and maintained at doT of 5% air saturation. PHB accumulation was growth associated product. Model of bacteria mechanism on utilizing tapioca and the mathematical model were proposed. The proposed model was suitable with the experimental phenomena. However, the rate of fermentation process was the controlling rate for overall PHB synthesis.   Abstrak   Salah satu pendekatan teknis untuk melakukan optimasi proses fermentasi adalah melakukan simulasi menggunakan model matematika.  Tujuan penelitian ini adalah mengembangkan model matematika yang dapat digunakan untuk melakukan simulasi proses pada fermentasi produksi polyhydroxybutyrate (PHB dari tapioka oleh Bacillus cereus IFO 13690. Tiga buah percobaan dengan konsentrasi amonium awal 0,286, 0,566, dan 1,203 g/L dilakukan pada fermentor dengan volume 5 L dan kecepatan pengadukan 500 rpm. Percobaan dilakukan dengan kondisi awal  pH 6,8 dan konsentrasi oksigen terlarut (doT 70% udara jenuh. Kondisi awal tidak dikontrol sehingga pH medium turun dan dijaga pada 5,6 menggunakan pengontrol pH. Sedangkan doT turun dan dikontrol pada 5% udara jenuh. Data percobaan dan model matematika menunjukkan bahwa produksi PHB mengikuti pola pertumbuhan berasosiasi dengan produk (growth associated product. Model mekanisme

  11. Generation of PHB from Spent Sulfite Liquor Using Halophilic Microorganisms.

    Science.gov (United States)

    Weissgram, Michaela; Gstöttner, Janina; Lorantfy, Bettina; Tenhaken, Raimund; Herwig, Christoph; Weber, Hedda K

    2015-06-08

    Halophilic microorganisms thrive at elevated concentrations of sodium chloride up to saturation and are capable of growing on a wide variety of carbon sources like various organic acids, hexose and also pentose sugars. Hence, the biotechnological application of these microorganisms can cover many aspects, such as the treatment of hypersaline waste streams of different origin. Due to the fact that the high osmotic pressure of hypersaline environments reduces the risk of contamination, the capacity for cost-effective non-sterile cultivation can make extreme halophilic microorganisms potentially valuable organisms for biotechnological applications. In this contribution, the stepwise use of screening approaches, employing design of experiment (DoE) on model media and subsequently using industrial waste as substrate have been implemented to investigate the applicability of halophiles to generate PHB from the industrial waste stream spent sulfite liquor (SSL). The production of PHB on model media as well as dilutions of industrial substrate in a complex medium has been screened for by fluorescence microscopy using Nile Blue staining. Screening was used to investigate the ability of halophilic microorganisms to withstand the inhibiting substances of the waste stream without negatively affecting PHB production. It could be shown that neither single inhibiting substances nor a mixture thereof inhibited growth in the investigated range, hence, leaving the question on the inhibiting mechanisms open. However, it could be demonstrated that some haloarchaea and halophilic bacteria are able to produce PHB when cultivated on 3.3% w/w dry matter spent sulfite liquor, whereas H. halophila was even able to thrive on 6.6% w/w dry matter spent sulfite liquor and still produce PHB.

  12. The effect of energy substrates on PHB accumulation of Acidiphilium cryptum DX1-1.

    Science.gov (United States)

    Xu, Ai-ling; Xia, Jin-lan; Song, Zhi-wen; Jiang, Peng; Xia, Yan; Wan, Min-xi; Zhang, Rui-yong; Yang, Yi; Liu, Ke-ke

    2013-09-01

    The effect of glucose and elemental sulfur on the growth and PHB accumulation of Acidiphilium cryptum DX1-1 was investigated. Meanwhile, the differential expressions of 19 genes related with PHB accumulation, sulfur metabolism and carbon fixed in heterotrophy, phytotrophy and mixotrophy were studied by RT-qPCR. The results showed that strain DX1-1 could accumulate PHB with sulfur as the energy substance and atmospheric CO2 as carbon resource. Glucose could improve the growth of strain DX1-1 cultured in medium with sulfur as the energy substance, and almost all the key enzyme-encoding genes related with PHB, sulfur metabolism and carbon fixed were basically up-regulated. PHB polymerase (Arcy_3030), ribulose-bisphosphate carboxylase (Acry_0825), ribulose-phosphate-epimerase (Acry_0022), and cysteine synthase A (Acry_2560) played important role in PHB accumulation, the modified expression of which could influence the PHB yield. With CO2 as carbon resource, the main initial substance of PHB accumulation for strain DX1-1 was acetyl-CoA, instead of acetate with the glucose as the carbon resource. Because of accumulating PHB by fixed atmospheric CO2 while independent of light, A. cryptum DX1-1 may have specifically potential in production of PHB.

  13. Expression pattern of phb2 and its potential function in spermatogenesis of scallop ( Chlamys farreri)

    Science.gov (United States)

    Han, Tiantian; Ma, Xiaoshi; Liang, Shaoshuai; Gao, Beibei; Zhang, Zhifeng

    2015-12-01

    Prohibitin (PHB) participates in several biological processes including apoptosis, transcription regulation and suppression of cell proliferation in mammals. In this study, we cloned the full-length cDNA of prohibitin 2 ( Cf-phb2) from the testis of scallop ( Chlamys farreri). The deduced amino acid sequence presented a characteristic of PHB family with the PHB domain, and clustered with PHB2 of other species. Temporal and spatial expression of Cf-phb2 in testis during the reproductive cycle was detected by quantitative real-time PCR (qRT-PCR) and in situ hybridization. The expression of Cf-phb2 in the testis increased when testis developed from the resting stage to mature stage. The mRNA abundance of Cf-phb2 was the highest at mature stage, which was about 15-fold higher than that at proliferative stage. The expression of Cf-phb2 could be detected by in situ hybridization in all types of germ cells in testis, including spermatogonia, spermatocytes, spermatids and spermatozoa. The intensity of the signal increased with the spermatogenesis and was the highest in spermatids, which suggested that CF-PHB2 might affect the spermatogenesis of C. farreri.

  14. Chloroform induces outstanding crystallization of poly(hydroxybutyrate) (PHB) vesicles within bacteria.

    Science.gov (United States)

    Rebois, Rolando; Onidas, Delphine; Marcott, Curtis; Noda, Isao; Dazzi, Alexandre

    2017-03-01

    Poly[(R)-3-hydroxyalkanoate]s or PHAs are aliphatic polyesters produced by numerous microorganisms. They are accumulated as energy and carbon reserve in the form of small intracellular vesicles. Poly[(R)-3-hydroxybutyrate] (PHB) is the most ubiquitous and simplest PHA. An atomic force microscope coupled with a tunable infrared laser (AFM-IR) was used to record highly spatially resolved infrared spectra of commercial purified PHB and native PHB within bacteria. For the first time, the crystallinity degree of native PHB within vesicle has been directly evaluated in situ without alteration due to the measure or extraction and purification steps of the polymer: native PHB is in crystalline state at 15% whereas crystallinity degree reaches 57% in commercial PHB. Chloroform addition on native PHB induces crystallization of the polymer within bacteria up to 60%. This possibility of probing and changing the physical state of polymer in situ could open alternative ways of production for PHB and others biopolymers. Graphical abstract An atomic force microscope coupled with a tunable infrared laser (AFM-IR) has been used to record local infrared spectra of biopolymer PHB within bacteria. Deconvolution of those spectra has allowed to determine in situ the crystallinity degree of native PHB.

  15. Glass transition and the rigid amorphous phase in semicrystalline blends of bacterial polyhydroxybutyrate PHB with low molecular mass atactic R,S-PHB-diol

    NARCIS (Netherlands)

    Hoehne, G.W.H.

    2004-01-01

    The glass transition and the crystallinity of blends of isotactic bacterial PHB and low molecular mass atactic R, S-PHB-diols was investigated by means of differential scanning calorimetry (DSC), temperature-modulated DSC and dielectric spectroscopy. It was found that (i) Tg of crystallized blends

  16. Metal Chloride Induced Formation of Porous Polyhydroxybutyrate (PHB) Films: Morphology, Thermal Properties and Crystallinity

    Science.gov (United States)

    Tan, W. L.; Yaakob, N. N.; Zainal Abidin, A.; Abu Bakar, M.; Abu Bakar, N. H. H.

    2016-06-01

    Polyhydroxybutyrate (PHB) films with highly porous structures were synthesized using a one phase system comprising of metal chloride/methanol/PHB/chloroform (MCl2/CH3OH/PHB/CHCl3). SEM analyses confirmed that the MCl2 (where M = Cu2+ or Ni2+) induced porous structures with pore sizes ranging from 0.3 - 2.0 μm. The average pore size increased with the increasing MCl2 content. There existed weak physical interactions between the PHB chains and MCl2 as revealed by FTIR and NMR spectroscopies. The residue of MCl2 in the porous PHB film does not exert significant influence on the thermal stability of PHB. Nevertheless, the crystallinity of the prepared film is enhanced, as MCl2 acts as the nucleation sites to promote the growth of spherullites.

  17. Deficiency of PHB complex impairs respiratory supercomplex formation and activates mitochondrial flashes.

    Science.gov (United States)

    Jian, Chongshu; Xu, Fengli; Hou, Tingting; Sun, Tao; Li, Jinghang; Cheng, Heping; Wang, Xianhua

    2017-08-01

    Prohibitins (PHBs; prohibitin 1, PHB1 or PHB, and prohibitin 2, PHB2) are evolutionarily conserved and ubiquitously expressed mitochondrial proteins. PHBs form multimeric ring complexes acting as scaffolds in the inner mitochondrial membrane. Mitochondrial flashes (mitoflashes) are newly discovered mitochondrial signaling events that reflect electrical and chemical excitations of the organelle. Here, we investigate the possible roles of PHBs in the regulation of mitoflash signaling. Downregulation of PHBs increases mitoflash frequency by up to 5.4-fold due to elevated basal reactive oxygen species (ROS) production in the mitochondria. Mechanistically, PHB deficiency impairs the formation of mitochondrial respiratory supercomplexes (RSCs) without altering the abundance of individual respiratory complex subunits. These impairments induced by PHB deficiency are effectively rescued by co-expression of PHB1 and PHB2, indicating that the multimeric PHB complex acts as the functional unit. Furthermore, downregulating other RSC assembly factors, including SCAFI (also known as COX7A2L), RCF1a (HIGD1A), RCF1b (HIGD2A), UQCC3 and SLP2 (STOML2), all activate mitoflashes through elevating mitochondrial ROS production. Our findings identify the PHB complex as a new regulator of RSC formation and mitoflash signaling, and delineate a general relationship among RSC formation, basal ROS production and mitoflash biogenesis. © 2017. Published by The Company of Biologists Ltd.

  18. Analyzing the Effects of Nitrogen Deficiency on the PHB Production of Methylosinus trichosporium OB3b

    Science.gov (United States)

    Kyauk, E.

    2011-12-01

    Polyhydroxybutyrate (PHB) is a biodegradable thermoplastic that is produced by various microorganisms. Because of its potential to replace conventional plastics, it has been closely researched in the past few years. Methanotrophic bacteria, bacteria that consume methane, produce this bioplastic when it lacks certain nutrients. The utilization of methane to produce PHB shows much promise as methane is a cheap, plentiful gas. In this study, we observed the methanotroph, Methylosinus trichosporium OB3b , and its yield of PHB in the absence of nitrogen. The optical density of Methylosinus trichosporium OB3b was measured in order to observe cell growth and PHB production patterns over a 48 hour period.

  19. The presence of PHB granules in cytoplasm protects non-halophilic bacterial cells against the harmful impact of hypertonic environments.

    Science.gov (United States)

    Obruca, Stanislav; Sedlacek, Petr; Mravec, Filip; Krzyzanek, Vladislav; Nebesarova, Jana; Samek, Ota; Kucera, Dan; Benesova, Pavla; Hrubanova, Kamila; Milerova, Miluse; Marova, Ivana

    2017-10-25

    Numerous prokaryotes accumulate polyhydroxybutyrate (PHB) intracellularly as a storage material. It has also been proposed that PHB accumulation improves bacterial stress resistance. Cupriavidus necator and its PHB non-accumulating mutant were employed to investigate the protective role of PHB under hypertonic conditions. The presence of PHB granules enhanced survival of the bacteria after exposure to hypertonic conditions. Surprisingly, when coping with such conditions, the bacteria did not utilize PHB to harvest carbon or energy, suggesting that, in the osmotic upshock of C. necator, the protective mechanism of PHB granules is not associated with their hydrolysis. The presence of PHB granules influenced the overall properties of the cells, since challenged PHB-free cells underwent massive plasmolysis accompanied by damage to the cell membrane and the leakage of cytoplasm content, while no such effects were observed in PHB containing bacteria. Moreover, PHB granules demonstrated "liquid-like" properties indicating that they can partially repair and stabilize cell membranes by plugging small gaps formed during plasmolysis. In addition, the level of dehydration and changes in intracellular pH in osmotically challenged cells were less pronounced for PHB-containing cultures, demonstrating the important role of PHB for bacterial survival under hyperosmotic conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Production of biodegradable plastic by polyhydroxybutyrate (PHB) accumulating bacteria using low cost agricultural waste material.

    Science.gov (United States)

    Getachew, Anteneh; Woldesenbet, Fantahun

    2016-12-12

    Polyhydroxybutyrates (PHBs) are macromolecules synthesized by bacteria. They are inclusion bodies accumulated as reserve materials when the bacteria grow under different stress conditions. Because of their fast degradability under natural environmental conditions, PHBs are selected as alternatives for production of biodegradable plastics. The aim of this work was to isolate potential PHB producing bacteria, evaluate PHB production using agro-residues as carbon sources. Among fifty bacterial strains isolated from different localities, ten PHB accumulating strains were selected and compared for their ability to accumulate PHB granules inside their cells. Isolate Arba Minch Waste Water (AWW) identified as Bacillus spp was found to be the best producer. The optimum pH, temperature, and incubation period for best PHB production by the isolate were 7, 37 °C, and 48 h respectively at 150 rpm. PHB production was best with glucose as carbon source and peptone as nitrogen source. The strain was able to accumulate 55.6, 51.6, 37.4 and 25% PHB when pretreated sugar cane bagasse, corn cob, teff straw (Eragrostis tef) and banana peel were used as carbon sources respectively. Fourier transform-infrared authentication results of the extracted and purified PHB identified its functional units as C-H, CH 2 , C=O and C-O groups. UV-Vis spectrophotometric analysis and biodegradability test confirmed the similarity of the extract with standard PHB and its suitability for bioplastic production. The isolated Bacillus sp can be used for feasible production of PHB using agro-residues especially sugarcane bagasse which can reduce the production cost in addition to reducing the disposal problem of these substrates. The yield of PHB can further be boosted by optimization of production parameters as substrates.

  1. The Role of Short-Chain Conjugated Poly-(R-3-Hydroxybutyrate (cPHB in Protein Folding

    Directory of Open Access Journals (Sweden)

    Rosetta N. Reusch

    2013-05-01

    Full Text Available Poly-(R-3-hydroxybutyrate (PHB, a linear polymer of R-3-hydroxybutyrate (R-3HB, is a fundamental constituent of biological cells. Certain prokaryotes accumulate PHB of very high molecular weight (10,000 to >1,000,000 residues, which is segregated within granular deposits in the cytoplasm; however, all prokaryotes and all eukaryotes synthesize PHB of medium-chain length (~100–200 residues which resides within lipid bilayers or lipid vesicles, and PHB of short-chain length (<12 residues which is conjugated to proteins (cPHB, primarily proteins in membranes and organelles. The physical properties of cPHB indicate it plays important roles in the targeting and folding of cPHB-proteins. Here we review the occurrence, physical properties and molecular characteristics of cPHB, and discuss its influence on the folding and structure of outer membrane protein A (OmpA of Escherichia coli.

  2. PHB-degrading bacteria isolated from the gastrointestinal tract of aquatic animals as protective actors against luminescent vibriosis.

    Science.gov (United States)

    Liu, Yiying; De Schryver, Peter; Van Delsen, Bart; Maignien, Loïs; Boon, Nico; Sorgeloos, Patrick; Verstraete, Willy; Bossier, Peter; Defoirdt, Tom

    2010-10-01

    The use of poly-β-hydroxybutyrate (PHB) was shown to be successful in increasing the resistance of brine shrimp against pathogenic infections. In this study, we isolated for the first time PHB-degrading bacteria from a gastrointestinal environment. Pure strains of PHB-degrading bacteria were isolated from Siberian sturgeon, European sea bass and giant river prawn. The capability of selected isolates to degrade PHB was confirmed in at least two of three setups: (1) growth in minimal medium containing PHB as the sole carbon (C) source, (2) production of clearing zones on minimal agar containing PHB as the sole C source and (3) degradation of PHB (as determined by HPLC analysis) in 10% Luria-Bertani medium containing PHB. Challenge tests showed that the PHB-degrading activity of the selected isolates increased the survival of brine shrimp larvae challenged to a pathogenic Vibrio campbellii strain by a factor 2-3. Finally, one of the PHB-degrading isolates from sturgeon showed a double biocontrol effect because it was also able to inactivate acylhomoserine lactones, a type of quorum-sensing molecule that regulates the virulence of different pathogenic bacteria. Thus, the combined supplementation of a PHB-degrading bacterium and PHB as a synbioticum provides perspectives for improving the gastrointestinal health of aquatic animals. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Pedestrian hybrid beacon crosswalk system (PHB) or high-intensity activated crosswalk (HAWK).

    Science.gov (United States)

    2014-11-01

    The Pedestrian Hybrid Beacon Crosswalk (PHB) is a type of traffic control system, used to aid : pedestrians safely crossing the street and to regulate traffic flow. This study examines the : success of the first PHB installed in the state of Vermont....

  4. Study of effect of gamma radiation on molecular weight and mechanical properties of PHB and PHNV

    International Nuclear Information System (INIS)

    Fechine, Guilhermino J.M.; Terence, Mauro C.; Rabello, M.S.; Willen, Renate M.R.

    2011-01-01

    The effect of gamma radiation on molecular weight and mechanical properties (tensile and flexural) of PHB and PHBV samples was investigated. The values of stress and strain at the break point for both mechanical properties indicated that scission molecular reactions were predominant in PHB and PHBV samples submitted to gamma radiation. These results were confirmed by Size Exclusion Chromatography (SEC) analysis. (author)

  5. Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (Phb) from a Process Relevant Lignocellulosic Derived Sugar

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Mohagheghi, Ali; Mittal, Ashutosh; Pilath, Heidi; Johnson, David K.

    2015-03-22

    PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. In recent years a great effort has been made in bacterial production of PHB, yet the production cost of the polymer is still much higher than conventional petrochemical plastics. The high cost of PHB is because the cost of the substrates can account for as much as half of the total product cost in large scale fermentation. Thus searching for cheaper and better substrates is very necessary for PHB production. In this study, we demonstrate production of PHB by Cupriavidus necator from a process relevant lignocellulosic derived sugar stream, i.e., saccharified hydrolysate slurry from pretreated corn stover. Good cell growth was observed on slurry saccharified with advanced enzymes and 40~60% of PHB was accumulated in the cells. The mechanism of inhibition in the toxic hydrolysate generated by pretreatment and saccharification of biomass, will be discussed.

  6. Enrichments of methanotrophic-heterotrophic cultures with high poly-β-hydroxybutyrate (PHB) accumulation capacities.

    Science.gov (United States)

    Zhang, Tingting; Wang, Xiaowei; Zhou, Jiti; Zhang, Yu

    2018-03-01

    Methanotrophic-heterotrophic communities were selectively enriched from sewage sludge to obtain a mixed culture with high levels of poly-β-hydroxybutyrate (PHB) accumulation capacity from methane. Methane was used as the carbon source, N 2 as sole nitrogen source, and oxygen and Cu content were varied. Copper proved essential for PHB synthesis. All cultures enriched with Cu could accumulate high content of PHB (43.2%-45.9%), while only small amounts of PHB were accumulated by cultures enriched without Cu (11.9%-17.5%). Batch assays revealed that communities grown with Cu and a higher O 2 content synthesized more PHB, which had a wider optimal CH 4 :O 2 range and produced a high PHB content (48.7%) even though in the presence of N 2 . In all methanotrophic-heterotrophic communities, both methanotrophic and heterotrophic populations showed the ability to accumulate PHB. Although methane was added as the sole carbon source, heterotrophs dominated with abundances between 77.2% and 85.6%. All methanotrophs detected belonged to type II genera, which formed stable communities with heterotrophs of different PHB production capacities. Copyright © 2017. Published by Elsevier B.V.

  7. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor.

    Science.gov (United States)

    Jiang, Yang; Marang, Leonie; Kleerebezem, Robbert; Muyzer, Gerard; van Loosdrecht, Mark C M

    2011-05-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the microbial community structure of the PHB-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. Zoogloea and Plasticicumulans acidivorans dominated the SBRs operated at 20 °C and 30 °C, respectively. Both enrichments accumulated PHB more than 75% of cell dry weight. Short-term temperature change experiments revealed that P. acidivorans was more temperature sensitive as compared with Zoogloea. This is particularly true for the PHB degradation, resulting in incomplete PHB degradation in P. acidivorans at 20 °C. Incomplete PHB degradation limited biomass growth and allowed Zoogloea to outcompete P. acidivorans. The PHB content at the end of the feast phase correlated well with the cycle length at a constant solid retention time (SRT). These results suggest that to establish enrichment with the capacity to store a high fraction of PHB, the number of cycles per SRT should be minimized independent of the temperature.

  8. The Feasibility of Thermophilic Caldimonas manganoxidans as a Platform for Efficient PHB Production.

    Science.gov (United States)

    Hsiao, Li-Jung; Lin, Ji-Hong; Sankatumvong, Pantitra; Wu, Tzong-Ming; Li, Si-Yu

    2016-11-01

    Recently, poly(3-hydroxybutyrate) (PHB) has been found in a few thermophilic strains where several advantages can be gained from running fermentation at high temperatures. Caldimonas manganoxidans, a thermophilic gram-negative bacterium, was investigated for the feasibility as a PHB-producing strain. It is suggested that the best fermentation strategy for achieving the highest PHB concentration of 5.4 ± 1.1 g/L (from 20 g/L glucose) in 24 h is to use the fermentation conditions that are favored for the bacterial growth, yet temperature and pH should be chosen at conditions that are favored for the PHB content. Besides, the above fermentation conditions produce PHB that has a high molecular weight of 1274 kDa with a low polydispersity index (PDI) of 1.45, where the highest Mw of PHB of 1399 kDa (PDI of 1.32) is obtained in this study. To the best knowledge of authors, C. manganoxidans has the best PHB productivity among the thermophiles and is comparable to those common PHB-producing mesophiles.

  9. Intracellular PHB conversion in a type II methanotroph studied by 13 C NMR

    NARCIS (Netherlands)

    Vecherskaya, M.; Dijkema, C.; Stams, A.J.M.

    2001-01-01

    Poly-g-hydroxybutyrate (PHB) formation under aerobic conditions via incorporation of [13C-2]acetate as a cosubstrate and its intracellular degradation under anaerobic conditions in a Type II methanotroph was studied by 13C NMR. During PHB synthesis in the presence of labelled acetate, low levels of

  10. On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications.

    Science.gov (United States)

    Arrieta, Marina Patricia; Samper, María Dolores; Aldas, Miguel; López, Juan

    2017-08-29

    Poly(lactic acid) (PLA) is the most used biopolymer for food packaging applications. Several strategies have been made to improve PLA properties for extending its applications in the packaging field. Melt blending approaches are gaining considerable interest since they are easy, cost-effective and readily available processing technologies at the industrial level. With a similar melting temperature and high crystallinity, poly(hydroxybutyrate) (PHB) represents a good candidate to blend with PLA. The ability of PHB to act as a nucleating agent for PLA improves its mechanical resistance and barrier performance. With the dual objective to improve PLAPHB processing performance and to obtain stretchable materials, plasticizers are frequently added. Current trends to enhance PLA-PHB miscibility are focused on the development of composite and nanocomposites. PLA-PHB blends are also interesting for the controlled release of active compounds in the development of active packaging systems. This review explains the most relevant processing aspects of PLA-PHB based blends such as the influence of polymers molecular weight, the PLA-PHB composition as well as the thermal stability. It also summarizes the recent developments in PLA-PHB formulations with an emphasis on their performance with interest in the sustainable food packaging field. PLA-PHB blends shows highly promising perspectives for the replacement of traditional petrochemical based polymers currently used for food packaging.

  11. Estudo das propriedades mecânicas e térmicas do polímero Poli-3-hidroxibutirato (PHB e de compósitos PHB/pó de madeira Study of mechanical and thermal properties of the polymer Poly-3-hydroxybutyrate (PHB and PHB/wood flour composites

    Directory of Open Access Journals (Sweden)

    Miriam L. C. Machado

    2010-01-01

    Full Text Available O PHB (Poli-3-hidroxibutirato é um termoplástico biodegradável sintetizado por fermentação submersa a partir de matérias-primas renováveis. A utilização de fibras naturais tem sido pesquisada visando melhorar as propriedades e reduzir o custo do PHB. O objetivo deste trabalho foi o estudo das propriedades mecânicas (resistência à tração, térmicas (Análise termogravimétrica,TGA, e Calorimetria Exploratória Diferencial, DSC e reológicas (torque em câmera de mistura e Índice de Fluidez do PHB e de compósitos de PHB/pó de madeira processados e irradiados. Foram preparados compósitos com concentrações de PHB/pó de madeira de 90/10, 80/20 e 70/30 (m/m. Os materiais foram processados através das seguintes etapas de processamento: calandragem, fragmentação, extrusão, granulação, secagem e moldagem por injeção para confecção dos corpos de prova. A incorporação do pó de madeira aumentou o grau de cristalinidade e a temperatura de cristalização do polímero, e nos compósitos PHB/pó de madeira 80/20 e 70/30 a rigidez do material aumentou. A irradiação após o processamento (dose de 30 kGy provocou aumento da rigidez do PHB puro e dos compósitos PHB/pó de madeira 90/10 e 80/20, embora outras propriedades tenham decrescido. O compósito PHB/pó de madeira 70/30 apresentou os melhores resultados em termos econômicos e de processamento.PHB (Polyhydroxybutyrate is a biodegradable thermoplastic synthesized by submerse fermentation of renewable raw materials. The use of natural fibers has been largely researched to improve PHB properties, as well as reducing its cost. The purpose of this work was the study of the mechanical, thermal properties and rheological analyses (torque in mixer camera and melt flow index of processed and irradiated PHB, as well as PHB/wood flour composites. PHB/wood flour composites were prepared with PHB/wood relation of 90/10, 80/20 and 70/30 (w/w. Both pure PHB and composites were

  12. Production of three-dimensional structures of PHB using selective laser sintering

    International Nuclear Information System (INIS)

    Pereira, Tatiana F.; Costa, Marysilvia F.; Thire, Rossana M.S.M.; Oliveira, Marcelo F.; Maia, Izaque A.; Silva, Jorge V.L.

    2011-01-01

    Selective Laser Sintering (SLS) is a technology of layer-by-layer fabrication of three-dimensional physical models directly from their computational design. The poly(3-hydroxybutyrate) (PHB) is a microbial, biodegradable and semicrystalline polyester. The objective of this work was to produce PHB parts, evaluating the reuse of material in the production of the new parts. Images of SEM of part surface showed the formation of neck that indicates sintering between PHB particles during processing. Analysis of NMR and DSC of the reused polymer showed no changes in the chemical structure and thermal properties of PHB. The parts produced from virgin and reused PHB showed no significant difference in their thermal properties. This could suggest that the reuse of raw material did not influence the process reproducibility. (author)

  13. Mobilities

    DEFF Research Database (Denmark)

    to social networks, personal identities, and our relationship to the built environment. The omnipresence of mobilities within everyday life, high politics, technology, and tourism (to mention but a few) all point to a key insight harnessed by the ‘mobilities turn’. Namely that mobilities is much more than......The world is on the move. This is a widespread understanding by many inhabitants of contemporary society across the Globe. But what does it actually mean? During over one decade the ‘mobilities turn’ within the social sciences have provided a new set of insights into the repercussions of mobilities...... and environmental degradation. The spaces and territories marked by mobilities as well as the sites marked by the bypassing of such are explored. Moreover, the architectural and technological dimensions to infrastructures and sites of mobilities will be included as well as the issues of power, social exclusion...

  14. Increasing Completion Rate of an M4 Emergency Medicine Student End-of-Shift Evaluation Using a Mobile Electronic Platform and Real-Time Completion

    Directory of Open Access Journals (Sweden)

    Matthew C. Tews

    2016-06-01

    Full Text Available Introduction: Medical students on an emergency medicine rotation are traditionally evaluated at the end of each shift with paper-based forms, and data are often missing due to forms not being turned in or completed. Because students’ grades depend on these evaluations, change was needed to increase form rate of return. We analyzed a new electronic evaluation form and modified completion process to determine if it would increase the completion rate without altering how faculty scored student performance. Methods: During fall 2013, 29 faculty completed paper N=339 evaluations consisting of seven competencies for 33 students. In fall 2014, an electronic evaluation form with the same competencies was designed using an electronic platform and completed N=319 times by 27 faculty using 25 students’ electronic devices. Feedback checkboxes were added to facilitate collection of common comments. Data was analyzed with IBM® SPSS® 21.0 using multi-factor analysis of variance with the students’ global rating (GR as an outcome. Inter-item reliability was determined with Cronbach alpha. Results: There was a significantly higher completion rate (p=0.001 of 98% electronic vs. 69% paper forms, lower (p=0.001 missed GR rate (1% electronic. vs 12% paper, and higher mean scores (p=0.001 for the GR with the electronic (7.0±1.1 vs. paper (6.8±1.2 form. Feedback checkboxes were completed on every form. The inter-item reliability for electronic and paper forms was each alpha=0.95. Conclusion: The use of a new electronic form and modified completion process for evaluating students at the end of shift demonstrated a higher faculty completion rate, a lower missed data rate, a higher global rating and consistent collection of common feedback. The use of the electronic form and the process for obtaining the information made our end-of-shift evaluation process for students more reliable and provided more accurate, up-to-date information for student feedback and when

  15. Evaluation of PHB nanocomposite by low field NMR

    International Nuclear Information System (INIS)

    Silva, Mariana Bruno Rocha e; Tavares, Maria Ines Bruno

    2009-01-01

    Poly(3-hydroxybutyrate) (PHB) based on nanocomposites containing different amounts of a commercial organically modified clay (viscogel B8) were prepared employing solution intercalation method. The relationship among the processing conditions; molecular structure and intermolecular interaction, between both nanocomposite components, were investigated using a nuclear magnetic resonance (NMR), as a part of characterization methodology, which has been used by Tavares et al. It involves the proton spin-lattice relaxation time, T1 H, by solid state nuclear magnetic resonance, employing low field NMR. X-ray diffraction was also employed because it is a conventional technique, generally used to obtain the first information on nanocomposite formation. Changes in PHB crystallinity were observed after the organophilic nanoclay had been incorporated in the polymer matrix. These changes, in the microstructure, were detected by the variation of proton nuclear relaxation time values and by X-ray, which showed an increase in the clay interlamellar space due to the intercalation of the polymer in the clay between lamellae. (author)

  16. Controlling cell volume for efficient PHB production by Halomonas.

    Science.gov (United States)

    Jiang, Xiao-Ran; Yao, Zhi-Hao; Chen, Guo-Qiang

    2017-11-01

    Bacterial morphology is decided by cytoskeleton protein MreB and cell division protein FtsZ encoded by essential genes mreB and ftsZ, respectively. Inactivating mreB and ftsZ lead to increasing cell sizes and cell lengths, respectively, yet seriously reduce cell growth ability. Here we develop a temperature-responsible plasmid expression system for compensated expression of relevant gene(s) in mreB or ftsZ disrupted recombinants H. campaniensis LS21, allowing mreB or ftsZ disrupted recombinants to grow normally at 30°C in a bioreactor for 12h so that a certain cell density can be reached, followed by 36h cell size expansions or cell shape elongations at elevated 37°C at which the mreB and ftsZ encoded plasmid pTKmf failed to replicate in the recombinants and thus lost themselves. Finally, 80% PHB yield increase was achieved via controllable morphology manipulated H. campaniensis LS21. It is concluded that controllable expanding cell volumes (widths or lengths) provides more spaces for accumulating more inclusion body polyhydroxybutyrate (PHB) and the resulting cell gravity precipitation benefits the final separation of cells and product during downstream. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  17. Characterization of PHB1 and its role in mitochondrial maturation and yolk platelet degradation during development of Artemia embryos.

    Directory of Open Access Journals (Sweden)

    Xiang Ye

    Full Text Available BACKGROUND: To cope with harsh environments, crustaceans such as Artemia produce diapause gastrula embryos (cysts with suppressed metabolism. Metabolism and development resume during post-diapause development, but the mechanism behind these cellular events remains largely unknown. PRINCIPAL FINDING: Our study investigated the role of prohibitin 1 (PHB1 in metabolic reinitiation during post-diapause development. We found that PHB1 was developmentally regulated via changes in phosphorylation status and localization. Results from RNA interference experiments demonstrated PHB1 to be critical for mitochondrial maturation and yolk degradation during development. In addition, PHB1 was present in yolk platelets, and it underwent ubiquitin-mediated degradation during the proteolysis of yolk protein. CONCLUSIONS/SIGNIFICANCE: PHB1 has an indispensable role in coordinating mitochondrial maturation and yolk platelet degradation during development in Artemia. This novel function of PHB1 provides new clues to comprehend the roles of PHB1 in metabolism and development.

  18. Acid pretreatment and enzymatic saccharification of brown seaweed for polyhydroxybutyrate (PHB) production using Cupriavidus necator.

    Science.gov (United States)

    Azizi, Nahid; Najafpour, Ghasem; Younesi, Habibollah

    2017-08-01

    The brown seaweed Sargassum sp. was used as a feedstock to produce polyhydroxybutyarte (PHB) using Cupriavidus necator PTCC 1615. In order to release monomeric sugars, dilute acid hydrolysis of Sargassum sp. biomass was followed by enzymatic saccharification. In addition, the effect of different nitrogen sources was evaluated for PHB production. The fermentation of hydrolysate with the ammonium sulfate as selected nitrogen source resulted PHB yield of 0.54±0.01g/g reducing sugar. Then, NaCl was used as external stress factor which was added to the media. Addition of 8g/L NaCl had a positive impact on high PHB yield of 0.74±0.01g/g reducing sugar. Increasing trend of NaCl concentration to 16g/L was found to inhibit the production of PHB. Based on obtained results using 20g/L of reducing sugar, at desired condition the highest cell dry weight and PHB concentrations were 5.36±0.22 and 3.93±0.24g/L, respectively. The findings of this study reveal that Sargassum sp. is a promising feedstock for biopolymer production. The characteristics of produced PHB were analyzed by FTIR, differential scanning calorimetry and 1 H NMR. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Effects of Chemical Components on the Growth of Azotobacter vinelandii Mutant and PHB Production

    International Nuclear Information System (INIS)

    Nur Izzah Mohd Razak; Safiyyah Zainuddin; Ying, P.L.W.; Chyan, J.B.; Elly Ellyna Rashid

    2016-01-01

    Polyhydroxy butyrate (PHB) is a non-toxic biodegradable polymer produced by some bacteria and can be applied in medical, pharmacology and food industry. Eight types of chemical components acting as supplements were added to culture medium as nutrient pulses. The growth of bacteria was monitored by recording the absorbance value at 600 nm for every 24 hours of cultivation. PHB was extracted using chloroform. Reading at 235 nm was recorded to determine the PHB concentration. By observing the dry cell weight, we observed the addition of sucrose increased the biomass of Azotobacter vinelandii mutant from 1.5 mg/ mL to 5.6 mg/ mL and 8.4 mg/ mL after 3, 4 and 7 days of cultivation, respectively. The highest PHB concentration of 859.27 μg/ mL was obtained after seven days of cultivation in the medium which was supplied with urea sequentially, With sucrose, the PHB concentration increased from 25.45 μg/ ml to 99.59 μg/ ml and 655.56 μg/ ml after 3, 4 and 7 days of cultivation, respectively. The PHB concentrations obtained with sucrose-pulses were the second highest after urea. As a conclusion, sucrose and urea are the two major factors in the growth and PHB production by A. vinelandii mutant. (author)

  20. Material Properties and Antimicrobial Activity of Polyhydroxybutyrate (PHB) Films Incorporated with Vanillin.

    Science.gov (United States)

    Xavier, Janifer Raj; Babusha, Sudalaimuthu Thangaraj; George, Johnsy; Ramana, Karna Venkata

    2015-07-01

    Polyhydroxybutyrate (PHB) was produced by Bacillus mycoides DFC 1, isolated from garden soil. Antimicrobial (AM) films of PHB were prepared by incorporating vanillin (4-hydroxy-3-methoxybenzaldehyde) from 10 to 200 μg/g of PHB. The films were assessed for antimicrobial activity against foodborne pathogens and spoilage bacteria comprising of Escherichia coli, Salmonella typhimurium, Shigella flexneri, and Staphylococcus aureus and fungi such as Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus parasiticus, Aspergillus ochraceus, Penicillium viridicatum, and Penicillium clavigerum. The minimum concentration of vanillin required to exhibit antimicrobial activity was ≥80 μg/g PHB for bacteria and ≥50 μg/g PHB for fungi. The PHB films with and without vanillin were studied for mechanical and thermal properties such as tensile strength, Young's modulus, percentage elongation to break, melting temperature, and heat of fusion. The thermal stability of the films was studied using thermogravimetric analysis. The release kinetics of vanillin into food matrices was also checked using food stimulants. The study is intended to find applications for PHB films containing vanillin to enhance the shelf life of foods in the form of biodegradable wrapper.

  1. Effect of cycle time on polyhydroxybutyrate (PHB) production in aerobic mixed cultures.

    Science.gov (United States)

    Ozdemir, Sebnem; Akman, Dilek; Cirik, Kevser; Cinar, Ozer

    2014-03-01

    The aim of this study was to investigate the effect of cycle time on polyhydroxybutyrate (PHB) production under aerobic dynamic feeding system. The acetate-fed feast and famine sequencing batch reactor was used to enrich PHB accumulating microorganism. Sequencing batch reactor (SBR) was operated in four different cycle times (12, 8, 4, and 2 h) fed with a synthetic wastewater. The system performance was determined by monitoring total dissolved organic carbon, dissolved oxygen, oxidation-reduction potential, and PHB concentration. In this study, under steady-state conditions, the feast period of the SBR was found to allow the PHB storage while a certain part of stored PHB was used for continued growth in famine period. The percentage PHB storages by aerobic microorganism were at 16, 18, 42, and 55% for the 12, 8, 4, and 2-h cycle times, respectively. The PHB storage was increased as the length of the cycle time was decreased, and the ratio of the feast compared to the total cycle length was increased from around 13 to 33% for the 12 and 2-h cycle times, respectively.

  2. Effects of poly-β-hydroxybutyrate (PHB) on Siberian sturgeon (Acipenser baerii) fingerlings performance and its gastrointestinal tract microbial community.

    Science.gov (United States)

    Najdegerami, Ebrahim H; Tran, Tiet Ngoc; Defoirdt, Tom; Marzorati, Massimo; Sorgeloos, Patrick; Boon, Nico; Bossier, Peter

    2012-01-01

    Poly-β-hydroxybutyrate (PHB) is a natural polymer that can be depolymerized into water-soluble short-chain fatty acid monomers. These monomers can act as microbial control agents. In this study, the effects of partially replacing the diet of Siberian sturgeon fingerlings with 2% and 5% PHB were investigated. Replacing 2% of the diet with PHB improved weight gain, specific growth rate (SGR) and survival in the sturgeon fingerlings during the 10-week experimental period. Community-level physiological profiling and PCR-denaturing gradient gel electrophoresis (PCR-DGGE) were used to analyze the microbial community diversity and community organization in the sturgeon gastrointestinal tract. DGGE analysis revealed that PHB affected the intestinal microbial species richness and diversity. The highest species richness was observed with 2% PHB. DNA sequencing of the dominant bands in 2% and 5% PHB treatments revealed that PHB stimulated bacteria belonging to the genera Bacillus and Ruminococcaceae. Principal component analysis, Lorenz curves and the Shannon index of Biolog Ecoplate data revealed that aerobic metabolic potential of the bacterial community was different in the PHB-treated fishes as compared with the control situation. Overall, our results indicate that PHB act as microbial control agents and replacement of 2% of Siberian sturgeon fingerling diet with PHB has beneficial effects.

  3. Poly-β-hydroxybutyrate (PHB) accumulating Bacillus spp. improve the survival, growth and robustness of Penaeus monodon (Fabricius, 1798) postlarvae.

    Science.gov (United States)

    Laranja, Joseph Leopoldo Q; Ludevese-Pascual, Gladys L; Amar, Edgar C; Sorgeloos, Patrick; Bossier, Peter; De Schryver, Peter

    2014-10-10

    Low larval survival resulting from suboptimal culture conditions and luminous vibriosis poses a major problem for the larviculture of penaeid shrimp. In this study, a poly-β-hydroxybutyrate (PHB) accumulating mixed bacterial culture (mBC; 48.5% PHB on cell dry weight) and two PHB accumulating bacterial isolates, Bacillus sp. JL47 (54.7% PHB on cell dry weight) and Bacillus sp. JL1 (45.5% PHB on cell dry weight), were obtained from a Philippine shrimp culture pond and investigated for their capacity to improve growth, survival and robustness of Penaeus monodon postlarvae (PL). Shrimp PL1 and shrimp PL30 were provided with the PHB containing bacterial cultures in the feed for 30 days followed by, respectively, a challenge with pathogenic Vibrio campbellii and exposure to a lethal dose of ammonia. Prior to the pathogenic challenge or ammonia stress, growth and survival were higher for shrimp receiving the PHB accumulating bacteria as compared to shrimp receiving diets without bacterial additions. After exposure to the pathogenic challenge the shrimp fed PHB accumulating bacteria showed a higher survival as compared to non-treated shrimp, suggesting an increase in robustness for the shrimp. Similar effects were observed when shrimp PL30 were provided with the PHB accumulating bacterial cultures during a challenge with pathogenic V. campbellii through the water. The survival of shrimp exposed to lethal ammonia stress showed no significant difference between PHB accumulating bacteria-fed shrimp and non-PHB treated shrimp. The data illustrate that bacilli capable of accumulating PHB can provide beneficial effects to P. monodon post-larvae during culture in terms of growth performance, survival and resistance against pathogenic infection and ammonia stress. Further investigations are required to verify the PHB effect of the bacterial cultures on the shrimp. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Evaluation of simultaneous nutrient and COD removal with polyhydroxybutyrate (PHB) accumulation using mixed microbial consortia under anoxic condition and their bioinformatics analysis.

    Science.gov (United States)

    Jena, Jyotsnarani; Kumar, Ravindra; Dixit, Anshuman; Pandey, Sony; Das, Trupti

    2015-01-01

    Simultaneous nitrate-N, phosphate and COD removal was evaluated from synthetic waste water using mixed microbial consortia in an anoxic environment under various initial carbon load (ICL) in a batch scale reactor system. Within 6 hours of incubation, enriched DNPAOs (Denitrifying Polyphosphate Accumulating Microorganisms) were able to remove maximum COD (87%) at 2 g/L of ICL whereas maximum nitrate-N (97%) and phosphate (87%) removal along with PHB accumulation (49 mg/L) was achieved at 8 g/L of ICL. Exhaustion of nitrate-N, beyond 6 hours of incubation, had a detrimental effect on COD and phosphate removal rate. Fresh supply of nitrate-N to the reaction medium, beyond 6 hours, helped revive the removal rates of both COD and phosphate. Therefore, it was apparent that in spite of a high carbon load, maximum COD and nutrient removal can be maintained, with adequate nitrate-N availability. Denitrifying condition in the medium was evident from an increasing pH trend. PHB accumulation by the mixed culture was directly proportional to ICL; however the time taken for accumulation at higher ICL was more. Unlike conventional EBPR, PHB depletion did not support phosphate accumulation in this case. The unique aspect of all the batch studies were PHB accumulation was observed along with phosphate uptake and nitrate reduction under anoxic conditions. Bioinformatics analysis followed by pyrosequencing of the mixed culture DNA from the seed sludge revealed the dominance of denitrifying population, such as Corynebacterium, Rhodocyclus and Paraccocus (Alphaproteobacteria and Betaproteobacteria). Rarefaction curve indicated complete bacterial population and corresponding number of OTUs through sequence analysis. Chao1 and Shannon index (H') was used to study the diversity of sampling. "UCI95" and "LCI95" indicated 95% confidence level of upper and lower values of Chao1 for each distance. Values of Chao1 index supported the results of rarefaction curve.

  5. Evaluation of simultaneous nutrient and COD removal with polyhydroxybutyrate (PHB accumulation using mixed microbial consortia under anoxic condition and their bioinformatics analysis.

    Directory of Open Access Journals (Sweden)

    Jyotsnarani Jena

    Full Text Available Simultaneous nitrate-N, phosphate and COD removal was evaluated from synthetic waste water using mixed microbial consortia in an anoxic environment under various initial carbon load (ICL in a batch scale reactor system. Within 6 hours of incubation, enriched DNPAOs (Denitrifying Polyphosphate Accumulating Microorganisms were able to remove maximum COD (87% at 2 g/L of ICL whereas maximum nitrate-N (97% and phosphate (87% removal along with PHB accumulation (49 mg/L was achieved at 8 g/L of ICL. Exhaustion of nitrate-N, beyond 6 hours of incubation, had a detrimental effect on COD and phosphate removal rate. Fresh supply of nitrate-N to the reaction medium, beyond 6 hours, helped revive the removal rates of both COD and phosphate. Therefore, it was apparent that in spite of a high carbon load, maximum COD and nutrient removal can be maintained, with adequate nitrate-N availability. Denitrifying condition in the medium was evident from an increasing pH trend. PHB accumulation by the mixed culture was directly proportional to ICL; however the time taken for accumulation at higher ICL was more. Unlike conventional EBPR, PHB depletion did not support phosphate accumulation in this case. The unique aspect of all the batch studies were PHB accumulation was observed along with phosphate uptake and nitrate reduction under anoxic conditions. Bioinformatics analysis followed by pyrosequencing of the mixed culture DNA from the seed sludge revealed the dominance of denitrifying population, such as Corynebacterium, Rhodocyclus and Paraccocus (Alphaproteobacteria and Betaproteobacteria. Rarefaction curve indicated complete bacterial population and corresponding number of OTUs through sequence analysis. Chao1 and Shannon index (H' was used to study the diversity of sampling. "UCI95" and "LCI95" indicated 95% confidence level of upper and lower values of Chao1 for each distance. Values of Chao1 index supported the results of rarefaction curve.

  6. Bionanocomposite films based on plasticized PLA-PHB/cellulose nanocrystal blends.

    Science.gov (United States)

    Arrieta, M P; Fortunati, E; Dominici, F; López, J; Kenny, J M

    2015-05-05

    Optically transparent plasticized poly(lactic acid) (PLA) based bionanocomposite films intended for food packaging were prepared by melt blending. Materials were plasticized with 15wt% of acetyl(tributyl citrate) (ATBC) to improve the material processability and to obtain flexibile films. Poly(hydroxybutyrate) (PHB) was used to increase PLA crystallinity. The thermal stability of the PLA-PHB blends was improved by the addition of 5 wt% of cellulose nanocrystals (CNC) or modified cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose. The combination of ATBC and cellulose nanocrystals, mainly the better dispersed CNCs, improved the interaction between PLA and PHB. Thus, an improvement on the oxygen barrier and stretchability was achieved in PLA-PHB-CNCs-ATBC which also displayed somewhat UV light blocking effect. All bionanocomposite films presented appropriate disintegration in compost suggesting their possible applications as biodegradable packaging materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Surface-modified bacterial nanofibrillar PHB scaffolds for bladder tissue repair.

    Science.gov (United States)

    Karahaliloğlu, Zeynep; Demirbilek, Murat; Şam, Mesut; Sağlam, Necdet; Mızrak, Alpay Koray; Denkbaş, Emir Baki

    2016-01-01

    The aim of the study is in vitro investigation of the feasibility of surface-modified bacterial nanofibrous poly [(R)-3-hydroxybutyrate] (PHB) graft for bladder reconstruction. In this study, the surface of electrospun bacterial PHB was modified with PEG- or EDA via radio frequency glow discharge method. After plasma modification, contact angle of EDA-modified PHB scaffolds decreased from 110 ± 1.50 to 23 ± 0.5 degree. Interestingly, less calcium oxalate stone deposition was observed on modified PHB scaffolds compared to that of non-modified group. Results of this study show that surface-modified scaffolds not only inhibited calcium oxalate growth but also enhanced the uroepithelial cell viability and proliferation.

  8. Modification of titanium surfaces by adding antibiotic-loaded PHB spheres and PEG for biomedical applications.

    Science.gov (United States)

    Rodríguez-Contreras, Alejandra; Marqués-Calvo, María Soledad; Gil, Francisco Javier; Manero, José María

    2016-08-01

    Novel researches are focused on the prevention and management of post-operative infections. To avoid this common complication of implant surgery, it is preferable to use new biomaterials with antibacterial properties. Therefore, the aim of this work is to develop a method of combining the antibacterial properties of antibiotic-loaded poly(3-hydroxybutyrate) (PHB) nano- and micro-spheres and poly(ethylene glycol) (PEG) as an antifouling agent, with titanium (Ti), as the base material for implants, in order to obtain surfaces with antibacterial activity. The Ti surfaces were linked to both PHB particles and PEG by a covalent bond. This attachment was carried out by firstly activating the surfaces with either Oxygen plasma or Sodium hydroxide. Further functionalization of the activated surfaces with different alkoxysilanes allows the reaction with PHB particles and PEG. The study confirms that the Ti surfaces achieved the antibacterial properties by combining the antibiotic-loaded PHB spheres, and PEG as an antifouling agent.

  9. Microbial functional diversity plays an important role in the degradation of polyhydroxybutyrate (PHB) in soil.

    Science.gov (United States)

    Dey, Samrat; Tribedi, Prosun

    2018-03-01

    Towards bioremediation of recalcitrant materials like synthetic polymer, soil has been recognized as a traditional site for disposal and subsequent degradation as some microorganisms in soil can degrade the polymer in a non-toxic, cost-effective, and environment friendly way. Microbial functional diversity is a constituent of biodiversity that includes wide range of metabolic activities that can influence numerous aspects of ecosystem functioning like ecosystem stability, nutrient availability, ecosystem dynamics, etc. Thus, in the current study, we assumed that microbial functional diversity could play an important role in polymer degradation in soil. To verify this hypothesis, we isolated soil from five different sites of landfill and examined several microbiological parameters wherein we observed a significant variation in heterotrophic microbial count as well as microbial activities among the soil microcosms tested. Multivariate analysis (principle component analysis) based on the carbon sources utilization pattern revealed that soil microcosms showed different metabolic patterns suggesting the variable distribution of microorganisms among the soil microcosms tested. Since microbial functional diversity depends on both microbial richness and evenness, Shannon diversity index was determined to measure microbial richness and Gini coefficient was determined to measure microbial evenness. The tested soil microcosms exhibited variation in both microbial richness and evenness suggesting the considerable difference in microbial functional diversity among the tested microcosms. We then measured polyhydroxybutyrate (PHB) degradation in soil microcosms after desired period of incubation of PHB in soil wherein we found that soil microcosms having higher functional diversity showed enhanced PHB degradation and soil microcosms having lower functional diversity showed reduced PHB degradation. We also noticed that all the tested soil microcosms showed similar pattern in both

  10. Production of Bio polymer (PHB) from Whey by Local Strain of Bacillus cereus

    International Nuclear Information System (INIS)

    Abdel Kareem, H.; Hamed, D.; Omar, S.; Gebreel, H.; Khalaf, M.; El-M-Mahalawy, A.

    2008-01-01

    The local strain Bacillus cereus S 3 , which isolated from the soil attached to the rice root, was employed for PHB production from whey and soya extract as the main carbon and nitrogen sources. Some supplements such as (0.5 g) tryptone and (0.5 g) NaCl were added to 75 ml whey and 25 ml soya extract to optimize the PHB accumulation medium. Different parameters including; initial ph of the medium, working volume, NaCl concentration and inoculum age and size; were carried out under shaking flask conditions (150 rpm) at 30 degree C for 48 h of incubation to enhance the PHB accumulation. The maximum PHB accumulation (2.42 gl -1 ) was achieved at ph 6, 100 ml working volume, (0.5-2%) NaCl, at 60 h and 4 ml inoculum age and size, respectively. An experiment was conducted to investigate the effect of gamma irradiation on the activity of B. cereus S 3 towards PHB accumulation. At dose level 1.5 kGy the maximum PHB accumulation obtained was 3.2 gl -1

  11. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhuoyue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Song, Yue [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Zhang, Jing [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); Liu, Wei [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Cui, Jihong, E-mail: cjh@nwu.edu.cn [Lab of Tissue Engineering, Faculty of Life Science, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Provincial Key Laboratory of Biotechnology of Shaanxi, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province 710069 (China); Key Laboratory of Resource Biology and Modern Biotechnology in Western China, Ministry of Education, Northwest University, 229 TaiBai North Road, Xi' an, Shaanxi Province, 710069 (China); and others

    2017-03-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

  12. Bioconversion of fish solid waste into PHB using Bacillus subtilis based submerged fermentation process.

    Science.gov (United States)

    Mohapatra, S; Sarkar, B; Samantaray, D P; Daware, A; Maity, S; Pattnaik, S; Bhattacharjee, S

    2017-12-01

    Currently, one of the major problem affecting the world is solid waste management, predominantly petroleum-based plastic and fish solid waste (FSW). However, it is very difficult to reduce the consumption of plastic as well as fish products, but it is promising to convert FSW to biopolymer to reduce eco-pollution. On account of that, the bioconversion of FSW extract to polyhydroxybutyrate (PHB) was undertaken by using Bacillus subtilis (KP172548). Under optimized conditions, 1.62 g/L of PHB has been produced by the bacterium. The purified compound was further characterized by advanced analytical technologies to elucidate its chemical structure. Results indicated that the biopolymer was found to be PHB, the most common homopolymer of polyhydroxyalkanoates (PHAs). This is the first report demonstrating the efficacy of B. subtilis to utilize FSW extract to produce biopolymer. The biocompatibility of the PHB against murine macrophage cell line RAW264.7 demonstrated that, it was comparatively less toxic, favourable for surface attachment and proliferation in comparison with poly-lactic acid (PLA) and commercially available PHB. Thus, further exploration is highly indispensable to use FSW extract as a substrate for production of PHB at pilot scale.

  13. Model-Based Nutrient Feeding Strategies for the Increased Production of Polyhydroxybutyrate (PHB) by Alcaligenes latus.

    Science.gov (United States)

    Gahlawat, Geeta; Srivastava, Ashok K

    2017-10-01

    Polyhydroxyalkanoates (PHAs) are biodegradable polymers which are considered as an effective alternative for conventional plastics due to their mechanical properties similar to the latter. However, the widespread use of these polymers is still hampered due to their higher cost of production as compared to plastics. The production cost could be overcome by obtaining high yields and productivity. The goal of the present research was to enhance the yield of polyhydroxybutyrate (PHB) with the help of two simple fed-batch cultivation strategies. In the present study, average batch kinetic and substrate limitation/inhibition study data of Alcaligenes latus was used for the development of PHB model which was then adopted for designing various off-line nutrient feeding strategies to enhance PHB accumulation. The predictive ability of the model was validated by experimental implementation of two fed-batch strategies. One such dynamic strategy of fed-batch cultivation under pseudo-steady state with respect to nitrogen and simultaneous carbon feeding strategy resulted in significantly high biomass and PHB concentration of 39.17 g/L and 29.64 g/L, respectively. This feeding strategy demonstrated a high PHB productivity and PHB content of 0.6 g/L h and 75%, respectively, which were remarkably high in comparison to batch cultivation. The mathematical model can also be employed for designing various other nutrient feeding strategies.

  14. PURIFICATION AND CHARACTERIZATION OF POLY-HYDROXYBUTYRATE (PHB IN CUPRIAVIDUS NECATOR

    Directory of Open Access Journals (Sweden)

    Sergio Leon De Rooy

    2010-06-01

    Full Text Available Purification and characterization of biodegradable plastic namely Polyhydroxybutyrate (PHB in Cupriavidus necator have been carried out. C. necator was grown on a Ramsay medium with fixed substrate conditions and optimized for time. Stepwise purification of PHB was carried out, by using hydrogen peroxide and chloroform. The effect of temperature, time, and hydrogen peroxide concentration on the purification were also evaluated. The extracted PHB was studied with XRD, FTIR and 1H-NMR and 13C-NMR to determine its structure and purity. Yield and crystallinity were also studied with HPLC and XRD, respectively. The results of the research showed that higher concentrations of hydrogen peroxide gave better yields, whereas higher temperatures and longer lysis times led to different results. Higher crystallinity was observed when purification temperatures were elevated, but higher hydrogen peroxide concentration and longer extraction time gave varying crystallinity. The highest yield ca 66.10 % DCW was reached by purification using H2O2 20 %, at 100 oC for 2 h. The results of   TGA analysis indicated that the purity of the PHB obtained was about 75 % and by using DSC, it was found that the PHB showed good thermal properties.   Keywords:  PHB, recovery, hydrogen peroxide, characterization

  15. Pseudogene PHBP1 promotes esophageal squamous cell carcinoma proliferation by increasing its cognate gene PHB expression.

    Science.gov (United States)

    Feng, Feiyue; Qiu, Bin; Zang, Ruochuan; Song, Peng; Gao, Shugeng

    2017-04-25

    Natural antisense transcripts (NATs) as one of the most diverse classes of long noncoding RNAs (lncRNAs), have been demonstrated involved in fundamental biological processes in human. Here, we reported that human prohibitin gene pseudogene 1 (PHBP1) was upregulated in ESCC, and increased PHBP1 expression in ESCC was associated with clinical advanced stage. Functional experiments showed that PHBP1 knockdown inhibited ESCC cells proliferation, colony formation and xenograft tumor growth in vitro and in vivo by causing cell-cycle arrest at the G1-G0 phase. Mechanisms analysis revealed that PHBP1 transcript as an antisense transcript of PHB is partially complementary to PHB mRNA and formed an RNA-RNA hybrid with PHB, consequently inducing an increase of PHB expression at both the mRNA and protein levels. Furthermore, PHBP1 expression is strongly correlated with PHB expression in ESCC tissues. Collectively, this study elucidates an important role of PHBP1 in promoting ESCC partly via increasing PHB expression.

  16. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering

    International Nuclear Information System (INIS)

    Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong

    2017-01-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2 months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. - Highlights: • We laminated the nHA/PHB layers to obtain a scaffold for bone tissue engineering. • The laminated scaffold performed optimized cell-loading capacity. • MSCs exhibited osteogenic phenotypes on the laminated scaffold. • Osteoid tissue formed throughout the laminated scaffold after 2 months in vivo. The laminated bio-composite scaffolds can be applied to bone regeneration.

  17. PHB Associates with the HIRA Complex to Control an Epigenetic-Metabolic Circuit in Human ESCs.

    Science.gov (United States)

    Zhu, Zhexin; Li, Chunliang; Zeng, Yanwu; Ding, Jianyi; Qu, Zepeng; Gu, Junjie; Ge, Laixiang; Tang, Fan; Huang, Xin; Zhou, Chenlin; Wang, Ping; Zheng, Deyou; Jin, Ying

    2017-02-02

    The chromatin landscape and cellular metabolism both contribute to cell fate determination, but their interplay remains poorly understood. Using genome-wide siRNA screening, we have identified prohibitin (PHB) as an essential factor in self-renewal of human embryonic stem cells (hESCs). Mechanistically, PHB forms protein complexes with HIRA, a histone H3.3 chaperone, and stabilizes the protein levels of HIRA complex components. Like PHB, HIRA is required for hESC self-renewal. PHB and HIRA act together to control global deposition of histone H3.3 and gene expression in hESCs. Of particular note, PHB and HIRA regulate the chromatin architecture at the promoters of isocitrate dehydrogenase genes to promote transcription and, thus, production of α-ketoglutarate, a key metabolite in the regulation of ESC fate. Our study shows that PHB has an unexpected nuclear role in hESCs that is required for self-renewal and that it acts with HIRA in chromatin organization to link epigenetic organization to a metabolic circuit. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Extraction and Characterization of Polyhydroxybutyrates (PHB from Bacillus thuringiensisKSADL127 Isolated from Mangrove Environments of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Abdullah A. Alarfaj

    2015-10-01

    Full Text Available ABSTRACTPolyhydroxybutyrate (PHB is a renowned biodegradable plastic that do not release any toxins or residues in the environment like petroleum based plastics. In the present study, 50 bacteria isolated from mangrove niche, Saudi Arabia, were screened for maximum PHB production. All the 50 strains showed positive for PHB production, of which one strain showed maximum of 137 mgL-1. The most PHB accumulated bacterium was selected and identified asBacillus thuringiensis KSADL127, based on phenotypic characterization and 16S rRNA sequence analysis. Characterization of extracted PHB was carried out by FT-IR, NMR, UV spectroscopy, DSC, TGA, and LC-MS, which later confirmed the presence of intracellular accumulated polymer and substantiated as PHB.

  19. Effect of composition ratio on the thermal and physical properties of semicrystalline PLA/PHB-HHx composites.

    Science.gov (United States)

    Lim, Jung Seop; Park, Ku-il; Chung, Gun Soo; Kim, Jong Hoon

    2013-05-01

    In this study, composites of semicrystalline, biodegradable polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHB-HHx) were prepared by direct melt compounding. The physical and thermal properties of the composites were investigated as a function of the composition ratio. Differential scanning calorimetry analysis indicated that PLA and PHB-HHx formed immiscible composites over the observed range of composition. The crystallization of PLA was gradually suppressed by increasing proportions of PHB-HHx. Dynamic mechanical analysis results confirmed that the innate ductility of PHB-HHX and its inhibiting effect on PLA crystallization improved the stiffness of the composite compared to those of neat PLA. The infrared spectra of the immiscible PLA/PHB-HHx composites at two crystallization temperatures (30 °C, 130 °C) were obtained and presented. At 30 °C, PHB-HHx existed as crystalline domains in the PLA matrix, while, amorphous phase of molten PHB-HHx was diffused within the crystalline phase of PLA at 130 °C. The interaction between PHB-HHX and PLA could not be elucidated from the temperature data. Mechanical tests showed that the addition of PHB-HHx improves ductility of PLA/PHB-HHx composite. Morphological analysis revealed that small proportions of PHB-HHx exhibited less tendency to aggregate, which resulted in greater plastic deformation and improved toughness. From this study, PLA blended with small portions of PHB-HHx may further expand the use of bio-friendly resources in a variety of applications such as flexible films, food packaging and something like that. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Draft Genome Sequence of Bacillus aryabhattai Strain PHB10, a Poly(3-Hydroxybutyrate)-Accumulating Bacterium Isolated from Domestic Sewerage.

    Science.gov (United States)

    Balakrishna Pillai, Aneesh; Jaya Kumar, Arjun; Thulasi, Kavitha; Reghunathan, Dinesh; Prasannakumar, Manoj; Kumarapillai, Harikrishnan

    2017-10-12

    Bacillus aryabhattai PHB10 is a poly(3-hydroxybutyrate) (PHB)-accumulating bacterium isolated from domestic sewerage. Here, we report the 4.19-Mb draft genome sequence, with 4,050 protein-coding genes and a G+C content of 37.5%. This sequence will be helpful in the study of the high-level PHB accumulation mechanism of the strain. Copyright © 2017 Balakrishna Pillai et al.

  1. Effective recovery of poly-β-hydroxybutyrate (PHB) biopolymer from Cupriavidus necator using a novel and environmentally friendly solvent system.

    Science.gov (United States)

    Fei, Tao; Cazeneuve, Stacy; Wen, Zhiyou; Wu, Lei; Wang, Tong

    2016-05-01

    This work demonstrates a significant advance in bioprocessing for a high-melting lipid polymer. A novel and environmental friendly solvent mixture, acetone/ethanol/propylene carbonate (A/E/P, 1:1:1 v/v/v) was identified for extracting poly-hydroxybutyrate (PHB), a high-value biopolymer, from Cupriavidus necator. A set of solubility curves of PHB in various solvents was established. PHB recovery of 85% and purity of 92% were obtained from defatted dry biomass (DDB) using A/E/P. This solvent mixture is compatible with water, and from non-defatted wet biomass, PHB recovery of 83% and purity of 90% were achieved. Water and hexane were evaluated as anti-solvents to assist PHB precipitation, and hexane improved recovery of PHB from biomass to 92% and the purity to 93%. A scale-up extraction and separation reactor was designed, built and successfully tested. Properties of PHB recovered were not significantly affected by the extraction solvent and conditions, as shown by average molecular weight (1.4 × 10(6) ) and melting point (175.2°C) not being different from PHB extracted using chloroform. Therefore, this biorenewable solvent system was effective and versatile for extracting PHB biopolymers. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:678-685, 2016. © 2016 American Institute of Chemical Engineers.

  2. Effects of dietary poly-β-hydroxybutyrate (PHB) on microbiota composition and the mTOR signaling pathway in the intestines of litopenaeus vannamei.

    Science.gov (United States)

    Duan, Yafei; Zhang, Yue; Dong, Hongbiao; Wang, Yun; Zhang, Jiasong

    2017-12-01

    Poly-β-hydroxybutyrate (PHB) is a natural polymer of the short chain fatty acid β-hydroxybutyrate, which acts as a microbial control agent. The mammalian target of the rapamycin (mTOR) signaling pathway plays a crucial role in intestine inflammation and epithelial morphogenesis. In this study, we examined the composition of intestine microbiota, and mTOR signaling-related gene expression in Pacific white shrimp Litopenaeus vannamei fed diets containing different levels of PHB: 0% (Control), 1% (PHB1), 3% (PHB3), and 5% (PHB5) (w/w) for 35 days. High-throughput sequencing analysis revealed that dietary PHB altered the composition and diversity of intestine microbiota, and that the microbiota diversity decreased with the increasing doses of PHB. Specifically, dietary PHB increased the relative abundance of Proteobacteria and Tenericutes in the PHB1 and PHB5 groups, respectively, and increased that of Gammaproteobacteria in the three PHB groups. Alternatively, PHB decreased Alphaproteobacteria in the PHB3 and PHB5 groups. At the genus level, dietary PHB increased the abundance of beneficial bacteria, such as Bacillus, Lactobacillus, Lactococcus, Clostridium, and Bdellovibrio. The relative mRNA expression levels of the mTOR signaling-related genes TOR, 4E-BP, eIF4E1α, and eIF4E2 all increased in the three PHB treatment groups. These results revealed that dietary PHB supplementation had a beneficial effect on intestine health of L. vannamei by modulating the composition of intestine microbiota and activating mTOR signaling.

  3. Prohibitin (PHB) acts as a potent survival factor against ceramide induced apoptosis in rat granulosa cells.

    Science.gov (United States)

    Chowdhury, Indrajit; Branch, Alicia; Olatinwo, Moshood; Thomas, Kelwyn; Matthews, Roland; Thompson, Winston E

    2011-08-29

    Ceramide is a key factor in inducing germ cell apoptosis by translocating from cumulus cells into the adjacent oocyte and lipid rafts through gap junctions. Therefore studies designed to elucidate the mechanistic pathways in ceramide induced granulosa cell (GC) apoptosis and follicular atresia may potentially lead to the development of novel lipid-based therapeutic strategies that will prevent infertility and premature menopause associated with chemo and/or radiation therapy in female cancer patients. Our previous studies have shown that Prohibitin (PHB) is intimately involved in GCs differentiation, atresia, and luteolysis. In the present study, we have examined the functional effects of loss-/gain-of-function of PHB using adenoviral technology in delaying apoptosis induced by the physiological ligand ceramide in rat GCs. Under these experimental conditions, exogenous ceramide C-8 (50 μM) augmented the expression of mitochondrial PHB and subsequently cause the physical destruction of GC by the release of mitochondrial cytochrome c and activation of caspase-3. In further studies, silencing of PHB expression by adenoviral small interfering RNA (shRNA) sensitized GCs to ceramide C8-induce apoptosis. In contrast, adenovirus (Ad) directed overexpression of PHB in GCs resulted in increased PHB content in mitochondria and delayed the onset of ceramide induced apoptosis in the infected GCs. Taken together, these results provide novel evidences that a critical level of PHB expression within the mitochondria plays a key intra-molecular role in GC fate by mediating the inhibition of apoptosis and may therefore, contribute significantly to ceramide induced follicular atresia. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. MONITORIAMENTO DO PROCESSO DE PRODUÇÃO DO PHB

    Directory of Open Access Journals (Sweden)

    Paulo Leonardo Ribeiro

    2013-06-01

    Full Text Available A prospecção em questão aborda o estudo tecnológico do monitoramento do processo de produção do polihidroxibutirato (PHB, usando como fontes de informações as bases de patentes. Para tanto, foram analisados banco de dados do Espacenet (EP. Os dados foram obtidos utilizando-se como palavras-chave “polyhydroxyalkanoate”, “polyhydroxybutyrate” e “polyhydroxyvalerate” e o código internacional C08L67, obtendo-se deste modo um total de 376 documentos, retirando-se os documentos em duplicata através do software Microsoft Excel, quantificaram-se 198 patentes. Quanto às análises referentes à evolução anual das patentes, 8,5% foram depositadas em 2000, 17,7% no período de 2007 a 2008 e 8,1% em 2012. Os Estados Unidos (35% de depósitos, o Japão (33% e a China (16% são os três países com maior número de documentos patenteados, destacando-se as instituições com seus respectivos inventores, as americanas Gamble & Procter (Harry Melik e Metabolix® (Isao Noda e a japonesa Canon® (Yano Tetsuya.

  5. PhaM is the physiological activator of poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) in Ralstonia eutropha.

    Science.gov (United States)

    Pfeiffer, Daniel; Jendrossek, Dieter

    2014-01-01

    Poly(3-hydroxybutyrate) (PHB) synthase (PhaC1) is the key enzyme of PHB synthesis in Ralstonia eutropha and other PHB-accumulating bacteria and catalyzes the polymerization of 3-hydroxybutyryl-CoA to PHB. Activity assays of R. eutropha PHB synthase are characterized by the presence of lag phases and by low specific activity. It is assumed that the lag phase is caused by the time necessary to convert the inactive PhaC1 monomer into the active dimeric form by an unknown priming process. The lag phase can be reduced by addition of nonionic detergents such as hecameg [6-O-(N-heptyl-carbamoyl)-methyl-α-D-glucopyranoside], which apparently accelerates the formation of PhaC1 dimers. We identified the PHB granule-associated protein (PGAP) PhaM as the natural primer (activator) of PHB synthase activity. PhaM was recently discovered as a novel type of PGAP with multiple functions in PHB metabolism. Addition of PhaM to PHB synthase assays resulted in immediate polymerization of 3HB coenzyme A with high specific activity and without a significant lag phase. The effect of PhaM on (i) PhaC1 activity, (ii) oligomerization of PhaC1, (iii) complex formation with PhaC1, and (iv) PHB granule formation in vitro and in vivo was shown by cross-linking experiments of purified proteins (PhaM, PhaC1) with glutardialdehyde, by size exclusion chromatography, and by fluorescence microscopic detection of de novo-synthesized PHB granules.

  6. Arm crank ergometry improves cardiovascular disease risk factors and community mobility independent of body composition in high motor complete spinal cord injury.

    Science.gov (United States)

    Bresnahan, James J; Farkas, Gary J; Clasey, Jody L; Yates, James W; Gater, David R

    2018-01-15

    Evaluate the effect of aerobic exercise using arm crank ergometry (ACE) in high motor complete (ISNCSCI A/B) spinal cord injury (SCI) as primarily related to cardiovascular disease (CVD) risk factors and functional mobility and secondarily to body composition and metabolic profiles. Longitudinal interventional study at an academic medical center. Ten previously untrained participants (M8/F2, Age 36.7 y ± 10.1, BMI 24.5 ± 6.0) with high motor complete SCI (C7-T5) underwent ACE exercise training 30 minutes/day × 3 days/week for 10 weeks at 70% VO 2Peak . Primary outcome measures were pre- and post-intervention changes in markers of cardiovascular fitness (graded exercise testing (GXT): VO 2 , VO 2Peak , respiratory quotient [RQ], GXT time, peak power, and energy expenditure [EE]) and community mobility (time to traverse a 100ft-5° ramp, and 12-minute WC propulsion test). Secondary outcome measures were changes in body composition and metabolic profiles (fasting and area under the curve for glucose and insulin, homeostasis model assessment [HOMA] for %β-cell activity [%β], %insulin sensitivity [%S], and insulin resistance [IR], and Matsuda Index [ISI Matsuda ]). Resting VO 2 , relative VO 2Peak , absolute VO 2Peak , peak power, RQ, 12-minute WC propulsion, fasting insulin, fasting G:I ratio, HOMA-%S, and HOMA-IR all significantly improved following intervention (P 0.05). Ten weeks of ACE at 70% VO 2Peak in high motor complete SCI improves aerobic capacity, community mobility, and metabolic profiles independent of changes in body composition.

  7. Mobilized peripheral blood stem cells compared with bone marrow from HLA-identical siblings for reduced-intensity conditioning transplantation in acute myeloid leukemia in complete remission

    DEFF Research Database (Denmark)

    Nagler, Arnon; Labopin, Myriam; Shimoni, Avichai

    2012-01-01

    Reduced-intensity conditioning (RIC)-alloSCT is increasingly used for acute myelogenous leukemia. Limited data are available for the comparison of peripheral blood stem cells with bone marrow for RIC-alloSCT. We used the European Group for Blood and Marrow Transplantation (EBMT) ALWP data...... to compare the outcome of mobilized peripheral blood stem cells (PBSC) (n = 1430) vs. bone marrow (BM) (n = 107) for acute myelogenous leukemia (AML) patients with complete remission that underwent RIC-alloSCT from compatible sibling donors. The leukemia features, the disease status, and the time from...

  8. Engineering cell wall synthesis mechanism for enhanced PHB accumulation in E. coli.

    Science.gov (United States)

    Zhang, Xing-Chen; Guo, Yingying; Liu, Xu; Chen, Xin-Guang; Wu, Qiong; Chen, Guo-Qiang

    2018-01-01

    The rigidity of bacterial cell walls synthesized by a complicated pathway limit the cell shapes as coccus, bar or ellipse or even fibers. A less rigid bacterium could be beneficial for intracellular accumulation of poly-3-hydroxybutyrate (PHB) as granular inclusion bodies. To understand how cell rigidity affects PHB accumulation, E. coli cell wall synthesis pathway was reinforced and weakened, respectively. Cell rigidity was achieved by thickening the cell walls via insertion of a constitutive gltA (encoding citrate synthase) promoter in front of a series of cell wall synthesis genes on the chromosome of several E. coli derivatives, resulting in 1.32-1.60 folds increase of Young's modulus in mechanical strength for longer E. coli cells over-expressing fission ring FtsZ protein inhibiting gene sulA. Cell rigidity was weakened by down regulating expressions of ten genes in the cell wall synthesis pathway using CRISPRi, leading to elastic cells with more spaces for PHB accumulation. The regulation on cell wall synthesis changes the cell rigidity: E. coli with thickened cell walls accumulated only 25% PHB while cell wall weakened E. coli produced 93% PHB. Manipulation on cell wall synthesis mechanism adds another possibility to morphology engineering of microorganisms. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  9. Three novel proteins co-localise with polyhydroxybutyrate (PHB) granules in Rhodospirillum rubrum S1.

    Science.gov (United States)

    Narancic, Tanja; Scollica, Elisa; Cagney, Gerard; O'Connor, Kevin E

    2018-04-01

    Polyhydroxybutyrate (PHB), a biodegradable polymer accumulated by bacteria is deposited intracellularly in the form of inclusion bodies often called granules. The granules are supramolecular complexes harbouring a varied number of proteins on their surface, which have specific but incompletely characterised functions. By comparison with other organisms that produce biodegradable polymers, only two phasins have been described to date for Rhodosprillum rubrum, raising the possibility that more await discovery. Using a comparative proteomics strategy to compare the granules of wild-type R. rubrum with a PHB-negative mutant housing artificial PHB granules, we identified four potential PHB granules' associated proteins. These were: Q2RSI4, an uncharacterised protein; Q2RWU9, annotated as an extracellular solute-binding protein; Q2RQL4, annotated as basic membrane lipoprotein; and Q2RQ51, annotated as glucose-6-phosphate isomerase. In silico analysis revealed that Q2RSI4 harbours a Phasin_2 family domain and shares low identity with a single-strand DNA-binding protein from Sphaerochaeta coccoides. Fluorescence microscopy found that three proteins Q2RSI4, Q2EWU9 and Q2RQL4 co-localised with PHB granules. This work adds three potential new granule associated proteins to the repertoire of factors involved in bacterial storage granule formation, and confirms that proteomics screens are an effective strategy for discovery of novel granule associated proteins.

  10. Laminated electrospun nHA/PHB-composite scaffolds mimicking bone extracellular matrix for bone tissue engineering.

    Science.gov (United States)

    Chen, Zhuoyue; Song, Yue; Zhang, Jing; Liu, Wei; Cui, Jihong; Li, Hongmin; Chen, Fulin

    2017-03-01

    Electrospinning is an effective means to generate nano- to micro-scale polymer fibers resembling native extracellular matrix for tissue engineering. However, a major problem of electrospun materials is that limited pore size and porosity may prevent adequate cellular infiltration and tissue ingrowth. In this study, we first prepared thin layers of hydroxyapatite nanoparticle (nHA)/poly-hydroxybutyrate (PHB) via electrospinning. We then laminated the nHA/PHB thin layers to obtain a scaffold for cell seeding and bone tissue engineering. The results demonstrated that the laminated scaffold possessed optimized cell-loading capacity. Bone marrow mesenchymal stem cells (MSCs) exhibited better adherence, proliferation and osteogenic phenotypes on nHA/PHB scaffolds than on PHB scaffolds. Thereafter, we seeded MSCs onto nHA/PHB scaffolds to fabricate bone grafts. Histological observation showed osteoid tissue formation throughout the scaffold, with most of the scaffold absorbed in the specimens 2months after implantation, and blood vessels ingrowth into the graft could be observed in the graft. We concluded that electrospun and laminated nanoscaled biocomposite scaffolds hold great therapeutic potential for bone regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Multifunctional PLA-PHB/cellulose nanocrystal films: processing, structural and thermal properties.

    Science.gov (United States)

    Arrieta, M P; Fortunati, E; Dominici, F; Rayón, E; López, J; Kenny, J M

    2014-07-17

    Cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose by acid hydrolysis were added into poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends to improve the final properties of the multifunctional systems. CNC were also modified with a surfactant (CNCs) to increase the interfacial adhesion in the systems maintaining the thermal stability. Firstly, masterbatch pellets were obtained for each formulation to improve the dispersion of the cellulose structures in the PLA-PHB and then nanocomposite films were processed. The thermal stability as well as the morphological and structural properties of nanocomposites was investigated. While PHB increased the PLA crystallinity due to its nucleation effect, well dispersed CNC and CNCs not only increased the crystallinity but also improved the processability, the thermal stability and the interaction between both polymers especially in the case of the modified CNCs based PLA-PHB formulation. Likewise, CNCs were better dispersed in PLA-CNCs and PLA-PHB-CNCs, than CNC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Effect of dietary poly-β-hydroxybutyrate (PHB) on growth performance, intestinal health status and body composition of Pacific white shrimp Litopenaeus vannamei (Boone, 1931).

    Science.gov (United States)

    Duan, Yafei; Zhang, Yue; Dong, Hongbiao; Zheng, Xiaoting; Wang, Yun; Li, Hua; Liu, Qingsong; Zhang, Jiasong

    2017-01-01

    In the present study, the effect of dietary supplementation of poly-β-hydroxybutyrate (PHB) on the growth performance, intestinal digestive and immune function, intestinal short-chain fatty acids (SCFA) content and body composition of Pacific white shrimp Litopenaeus vannamei (Boone, 1931) was evaluated. The shrimp was fed for 35 days with four different diets: 0%, 1%, 3% and 5% PHB supplemented feed. The results indicated that supplementation of PHB significantly increased the growth performance of the shrimp, and the feed conversion rate (FCR) in 3%PHB treatment group was significantly lower than the control (P PHB treatment groups were all significantly higher than that of the control (P PHB treatment (P > 0.05). The activities of intestinal immune enzymes such as total antioxidant capacity (T-AOC) and inducible nitric oxide synthase (iNOS) was significantly induced by 3%PHB treatment (P PHB treatment and nitric oxide (NO) content was significantly induced in three PHB treatments. Meanwhile, PHB induced significantly the expression level of intestinal heat shock protein 70 (HSP70), Toll and immune deficiency (Imd) gene. HE staining showed that PHB induced the intestinal health status of L. vannamei. Intestinal SCFA content analysis revealed that the content of propionic and butyric acid of 3%PHB treatment were significantly higher than that of the control (P PHB treatments, and the crude lipid in 1% and 5%PHB treatments were all significantly higher than the control (P PHB could improve the growth performance, modulated intestinal digestive and immune function, increased intestinal SCFA content and body composition in L. vannamei, and the optimum dietary PHB requirement by L. vannamei was estimated at 3% (w/w) diet. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Identification and Isolation of Genes Involved in Poly(β-Hydroxybutyrate) Biosynthesis in Azospirillum brasilense and Characterization of a phbC Mutant

    OpenAIRE

    Kadouri, Daniel; Burdman, Saul; Jurkevitch, Edouard; Okon, Yaacov

    2002-01-01

    Like many other prokaryotes, rhizobacteria of the genus Azospirillum produce high levels of poly(β-hydroxybutyrate) (PHB) under suboptimal growth conditions. Utilization of PHB by bacteria under stress has been proposed as a mechanism that favors their compatible establishment in competitive environments, thus showing great potential for the improvement of bacterial inoculants for plants and soils. The three genes that are considered to be essential in the PHB biosynthetic pathway, phbA (β-ke...

  14. Localization of poly(3-hydroxybutyrate) (PHB) granule-associated proteins during PHB granule formation and identification of two new phasins, PhaP6 and PhaP7, in Ralstonia eutropha H16.

    Science.gov (United States)

    Pfeiffer, Daniel; Jendrossek, Dieter

    2012-11-01

    Poly(3-hydroxybutyrate) (PHB) granules are covered by a surface layer consisting of mainly phasins and other PHB granule-associated proteins (PGAPs). Phasins are small amphiphilic proteins that determine the number and size of accumulated PHB granules. Five phasin proteins (PhaP1 to PhaP5) are known for Ralstonia eutropha. In this study, we identified three additional potential phasin genes (H16_B1988, H16_B2296, and H16_B2326) by inspection of the R. eutropha genome for sequences with "phasin 2 motifs." To determine whether the corresponding proteins represent true PGAPs, fusions with eYFP (enhanced yellow fluorescent protein) were constructed. Similar fusions of eYFP with PhaP1 to PhaP5 as well as fusions with PHB synthase (PhaC1), an inactive PhaC1 variant (PhaC1-C319A), and PhaC2 were also made. All fusions were investigated in wild-type and PHB-negative backgrounds. Colocalization with PHB granules was found for all PhaC variants and for PhaP1 to PhaP5. Additionally, eYFP fusions with H16_B1988 and H16_B2326 colocalized with PHB. Fusions of H16_B2296 with eYFP, however, did not colocalize with PHB granules but did colocalize with the nucleoid region. Notably, all fusions (except H16_B2296) were soluble in a ΔphaC1 strain. These data confirm that H16_B1988 and H16_B2326 but not H16_B2296 encode true PGAPs, for which we propose the designation PhaP6 (H16_B1988) and PhaP7 (H16_B2326). When localization of phasins was investigated at different stages of PHB accumulation, fusions of PhaP6 and PhaP7 were soluble in the first 3 h under PHB-permissive conditions, although PHB granules appeared after 10 min. At later time points, the fusions colocalized with PHB. Remarkably, PHB granules of strains expressing eYFP fusions with PhaP5, PhaP6, or PhaP7 localized predominantly near the cell poles or in the area of future septum formation. This phenomenon was not observed for the other PGAPs (PhaP1 to PhaP4, PhaC1, PhaC1-C319A, and PhaC2) and indicated that some phasins

  15. Cloning of phaCAB genes from thermophilic Caldimonas manganoxidans in Escherichia coli for poly(3-hydroxybutyrate) (PHB) production.

    Science.gov (United States)

    Lin, Ji-Hong; Lee, Ming-Chieh; Sue, You-Sheng; Liu, Yung-Chuan; Li, Si-Yu

    2017-08-01

    PHB biosynthesis pathway, consisting of three open reading frames (ORFs) that encode for β-ketothiolase (phaA Cma , 1179 bp), acetoacetyl-CoA reductase (phaB Cma , 738 bp), and PHA synthase (phaC Cma , 1694 bp), of Caldimonas manganoxidans was identified. The functions of PhaA, PhaB, and PhaC were demonstrated by successfully reconstructing PHB biosynthesis pathway of C. manganoxidans in Escherichia coli, where PHB production was confirmed by OD 600 , gas chromatography, Nile blue stain, and transmission electron microscope (TEM). The protein sequence alignment of PHB synthases revealed that phaC Cma shares at least 60% identity with those of class I PHB synthase. The effects of PhaA, PhaB, and PhaC expression levels on PHB production were investigated. While the overexpression of PhaB is found to be important in recombinant E. coli, performances of PHB production can be quantified as follows: PHB concentration of 16.8 ± 0.6 g/L, yield of 0.28 g/g glucose, content of 74%, productivity of 0.28 g/L/h, and Mw of 1.41 MDa.

  16. Gene expression profiles of prohibitin in testes of Octopus tankahkeei (ot-phb) revealing its possible role during spermiogenesis.

    Science.gov (United States)

    Mao, Hai-Tao; Wang, Da-Hui; Lan, Zhou; Zhou, Hong; Yang, Wan-Xi

    2012-05-01

    Prohibitin is essential for intracellular homeostasis and stabilization of mitochondrial respiratory chain complexes. To explore its functions during spermiogenesis of Octopus tankahkeei (O. tankahkeei), we have cloned and sequenced the cDNA of this mammalian PHB homologue (termed ot-PHB) from the testes of O. tankahkeei. The 1165 bp ot-phb cDNA contains a 100 bp 5' UTR, a 882 bp open reading frame and a 183 bp 3' UTR. The putative ot-PHB protein owns a transmembrane domain from 6 to 31 amino acid (aa) and a putative PHB domain from 26 to 178 aa. Protein alignment demonstrated that ot-PHB had 73.3, 73.6, 74.0, 75.1, and 45.4% identity with its homologues in Homo sapiens, Mus muculus, Danio rerio, Xenopus tropicalis and Trypanosoma brucei, respectively. Tissue distribution profile analysis revealed its presence in all the tissues examined. In situ hybridization in spermiogenic cells demonstrated that ot-phb was expressed moderately at the beginning of the spermiogenesis. The abundance of transcripts increased in intermediate spermatids and in drastically remodeling final spermatids. In mature spermatozoa, the residuary transcripts concentrated around the chondriosomal mantle where mitochondria assemble around. In summary, the expression of ot-phb during spermiogenesis implicates a potential function of this protein during mitochondrial ubiquitination. It is the first time to implicate the role of prohibitin in cephalopod spermiogenesis.

  17. Blends of PHB/PEG: obtention of matrices for use as controlled drug release systems

    International Nuclear Information System (INIS)

    Catoni, S.E.M.; Gomes, C.A.T.; Trindade, K.N.S.; Schneider, A.L.S.; Pezzin, A.P.T.; Soldi, V.

    2010-01-01

    Different materials have been used in the development of micro-and nanostructured systems for drug release. In general, poly(3-hydroxybutyrate) (PHB) matrixes have high crystallinity degree, justifying its slow degradation. This feature makes the attack of enzymes more difficult. Thus, the surface modification with hydrophilic polymers such as poly(ethylene glycol) (PEG) has been investigated in order to obtain particles which are not recognized and captured by phagocytic cells after in vivo administration, staying for a longer in the systemic circulation. In this work, PHB/PEG films were prepared by casting in different proportions and characterized by XRD, DSC, SEM, GPC and TGA. The films presented high crystallinity degree and showed uniformity, except the 50/50 composition which showed the presence of two phases. The results revealed that increasing percentage of PEG, the Tm of PHB was decreased, the thermal stability was dramatically decreased and molecular weight of the samples was lower. (author)

  18. PCR cloning of Polyhydroxybutyrate Synthase Gene (phbC) from Aeromonashydrophila

    International Nuclear Information System (INIS)

    Enan, M. R.; Bashandy, S.A.

    2006-01-01

    Plastic wastes are considered to be severe environmental contaminantscausing waste disposal problems. Widespread use of biodegradable plastics isone of the solutions, but it is limited by high production cost. A polymerasechain reaction (PCR) protocol was developed for the specific for the specificdetection and isolation of full-length gene coding for polyhydroxybutyrate(PBH). (PCR) strategy using (PHB) primers resulted in the amplification of(DNA) fragments with the expected size from all isolated bacteria (PBH)synthase gene was cloned directly from Aeromonas hydrophila genome for thefirst time. The clonec fragment was named (phbCAh) gene exhibits similarly to(PHB) synthase genes of Alcaligenes latus and Pseudomonas oleovorans (97%),Alcaligenes sp. (81%) and Comamonas acidovorans (84%). (author)

  19. Pretreatment and Anaerobic Co-digestion of Selected PHB and PLA Bioplastics

    Directory of Open Access Journals (Sweden)

    Nicholas Benn

    2018-01-01

    Full Text Available Conventional petroleum-derived plastics are recalcitrant to biodegradation and can be problematic as they accumulate in the environment. In contrast, it may be possible to add novel, biodegradable bioplastics to anaerobic digesters at municipal water resource recovery facilities along with primary sludge to produce more biomethane. In this study, thermal and chemical bioplastic pretreatments were first investigated to increase the rate and extent of anaerobic digestion. Subsequently, replicate, bench-scale anaerobic co-digesters fed synthetic primary sludge with and without PHB bioplastic were maintained for over 170 days. Two polyhydroxybutyrate (PHB, one poly(3-hydroxybutyrate-co-4-hydroxybutyrate and one polylactic acid (PLA bioplastic were investigated. Biochemical methane potential (BMP assays were performed using both untreated bioplastic as well as bioplastic pretreated at elevated temperature (35–90°C under alkaline conditions (8PHB and PLA pretreatment increased average BMP values up to over 100%. Average PHB lag time before methane production started decreased when pretreatment was performed. Bench-scale anaerobic co-digesters fed synthetic primary sludge with PHB bioplastic resulted in 80–98% conversion of two PHB bioplastics to biomethane and a 5% biomethane production increase at the organic loadings employed (sludge OLR = 3.6 g COD per L of reactor volume per day [g COD/LR-d]; bioplastic OLR = 0.75 g theoretical oxygen demand per L of reactor volume per day [ThOD/LR-d] compared to digesters not fed bioplastics. Anaerobic digestion or co-digestion is a feasible management option for biodegradable plastics.

  20. Engineering the growth pattern and cell morphology for enhanced PHB production by Escherichia coli.

    Science.gov (United States)

    Wu, Hong; Chen, Jinchun; Chen, Guo-Qiang

    2016-12-01

    E. coli JM109∆envC∆nlpD deleted with genes envC and nlpD responsible for degrading peptidoglycan (PG) led to long filamentous cell shapes. When cell fission ring location genes minC and minD of Escherichia coli were deleted, E. coli JM109∆minCD changed the cell growth pattern from binary division to multiple fissions. Bacterial morphology can be further engineered by overexpressing sulA gene resulting in inhibition on FtsZ, thus generating very long cellular filaments. By overexpressing sulA in E. coli JM109∆envC∆nlpD and E. coli JM109∆minCD harboring poly(3-hydroxybutyrate) (PHB) synthesis operon phbCAB encoded in plasmid pBHR68, respectively, both engineered cells became long filaments and accumulated more PHB compared with the wild-type. Under same shake flask growth conditions, E. coli JM109∆minCD (pBHR68) overexpressing sulA grown in multiple fission pattern accumulated approximately 70 % PHB in 9 g/L cell dry mass (CDM), which was significantly higher than E. coli JM109∆envC∆nlpD and the wild type, that produced 7.6 g/L and 8 g/L CDM containing 64 % and 51 % PHB, respectively. Results demonstrated that a combination of the new division pattern with elongated shape of E. coli improved PHB production. This provided a new vision on the enhanced production of inclusion bodies.

  1. ENHANCED PRODUCTION OF POLYHYDROXYBUTYRATE (PHB FROM AGRO-INDUSTRIAL WASTES; FED-BATCH CULTIVATION AND STATISTICAL MEDIA OPTIMIZATION

    Directory of Open Access Journals (Sweden)

    Mahmoud M. Berekaa

    2016-06-01

    Full Text Available Bacillus megaterium SW1-2 showed enhanced growth and polyhydroxybutyrate (PHB production during cultivation on date palm syrup (DEPS or sugar cane molasses. FT-IR and NMR spectroscopic analyses of the polymer accumulated during growth on DEPS revealed specific absorption peaks characteristic for PHB. 1.65 g/L of PHB (56.9% CDW was produced during growth on medium supplemented with 2 g/L of DEPS. Approximately, 36.1% CDW of PHB were recorded during growth on sugar cane molasses. Six runs of different fed-batch cultivation strategies were tested, the optimal run showed approximately 6.87-fold increase. Modified E2 medium was prefered recording 10.11 and 11.34 g/L of total PHB produced for runs 1 and 2, at the end of 96 h incubation period, respectively. Decrease in PHB was recorded during growth on complex medium (run 3 and run 4. In another independent optimization strategy, ten variables were concurrently examined for their significance on PHB production by Plackett-Burman statistical design for the first time. Among variables, DEPS-II and inoculum concentration followed by KH2PO4 and (NH42SO4 were found to be the most significant variables encourage PHB production. Indeed, DEPS-II or Fresh syrup is more significant than commercial syrup DEPS-I (p-value= 0.05. RPM, incubation period have highly negative effect on PHB production. Role of ago-industrial wastes, especially DEPS, in enhancement of PHB production was closely discussed.

  2. Effect of PBAT on Property of PLA/PHB Film Used for Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Ma Xiuyu

    2017-01-01

    Full Text Available A blend of poly(lactic acid (PLA (70% by weight and poly(3-hydroxybutyrate (PHB (30% by weight with a solubilizing agent (PBAT at four different concentrations (5%, 10%, 15% and 20% by weight per 100 parts of the blends were investigated by FTIR, SEM, mechanical testing, water vapor permeability test and biodegradation studies. SEM showed that PBAT can improve the compatibility between PLA and PHB. The film show a great Oxygen transmission rate and Water vapor permeability property when the content of PBAT is 10%.

  3. Assessment of completion of early medical abortion using a text questionnaire on mobile phones compared to a self-administered paper questionnaire among women attending four clinics, Cape Town, South Africa.

    Science.gov (United States)

    Constant, Deborah; de Tolly, Katherine; Harries, Jane; Myer, Landon

    2015-02-01

    In-clinic follow-up to assess completion of medical abortion is no longer a requirement according to World Health Organization guidance, provided adequate counselling is given. However, timely recognition of ongoing pregnancy, complications or incomplete abortion, which require treatment, is important. As part of a larger trial, this study aimed to establish whether women having a medical abortion could self-assess whether their abortion was complete using an automated, interactive questionnaire on their mobile phones. All 469 participants received standard abortion care and all returnees filled in a self-assessment on paper at clinic follow-up 2-3 weeks later. The 234 women allocated to receive the phone messages were also asked to do a mobile phone assessment at home ten days post-misoprostol. Completion of the mobile assessment was tracked by computer and all completed assessments, paper and mobile, were compared to providers' assessments at clinic follow-up. Of the 226 women able to access the mobile phone assessment, 176 (78%) completed it; 161 of them (93%) reported it was easy to do so. Neither mobile nor paper self-assessments predicted all cases needing additional treatment at follow-up. Prediction of complete procedures was good; 71% of mobile assessments and 91% of paper assessments were accurate. We conclude that an interactive questionnaire assessing completion of medical abortion on mobile phones is feasible in the South African setting; however, it should be done later than day 10 and combined with an appropriate pregnancy test to accurately detect incomplete procedures. Copyright © 2015 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

  4. Biological Production of a Hydrocarbon Fuel Intermediate Polyhydroxybutyrate (PHB) from a Process Relevant Lignocellulosic Derived Sugar (Poster)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.; Mittal, A.; Mohagheghi, A.; Johnson, D. K.

    2014-04-01

    PHAs are synthesized by many microorganisms to serve as intracellular carbon storage molecules. In some bacterial strains, PHB can account for up to 80% of cell mass. In addition to its application in the packaging sector, PHB also has great potential as an intermediate in the production of hydrocarbon fuels. PHB can be thermally depolymerized and decarboxylated to propene which can be upgraded to hydrocarbon fuels via commercial oligomerization technologies. Cupriavidus necator is the microorganism that has been most extensively studied and used for PHB production on an industrial scale; However the substrates used for producing PHB are mainly fructose, glucose, sucrose, fatty acids, glycerol, etc., which are expensive. In this study, we demonstrate production of PHB from a process relevant lignocellulosic derived sugar stream, i.e., saccharified slurry from pretreated corn stover. The strain was first investigated in shake flasks for its ability to utilize glucose, xylose and acetate. In addition, the strain was also grown on pretreated lignocellulose hydrolyzate slurry and evaluated in terms of cell growth, sugar utilization, PHB accumulation, etc. The mechanism of inhibition in the toxic hydrolysate generated by the pretreatment and saccharification process of biomass, was also studied.

  5. Characterization of poly-3-hydroxybutyrate (PHB) produced from Ralstonia eutropha using an alkali-pretreated biomass feedstock.

    Science.gov (United States)

    Saratale, Ganesh D; Oh, Min-Kyu

    2015-09-01

    Alkaline pretreatment using NaOH, KOH, or NaOCl has been applied to various types of waste biomass to enhance enzymatic digestibility. Pretreatment (2% NaOH, 121 °C, 30 min) of rice paddy straw (PS) resulted in a maximum yield of 703 mg of reducing sugar per gram of PS with 84.19% hydrolysis yield after a two-step enzymatic hydrolysis process. Ralstonia eutropha ATCC 17699 was tested for its ability to synthesize poly-3-hydroxybutyrate (PHB) using PS hydrolysates as its sole carbon source. It is noteworthy that dry cell weight, polyhydroxyalkanoate (PHA) accumulation and PHB yield with the use of laboratory-grade sugars were similar to those achieved with PS-derived sugars. Under optimized conditions, we observed maximal PHA accumulation (75.45%) and PHB production (11.42 g/L) within 48 h of fermentation. After PHB recovery, the physicochemical properties of PHB were determined by various analytical techniques, showed the results were consistent with the characteristics of a standard polymer of PHB. Thus, the PS hydrolysate proved to be an excellent cheap carbon substrate for PHB production. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Effects of the addiction of nucleating agents on crystallization of poly(3-hydroxybutyrate), PHB;Efeito da adicao de agentes de nucleacao na cristalizacao do poli[(R)-3-hidroxibutirato], PHB

    Energy Technology Data Exchange (ETDEWEB)

    Sarzi, Ariane C.; Felisberti, Maria I., E-mail: ari_sarzi@hotmail.co [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)

    2009-07-01

    Poly(3-hydroxybutyrate) is a naturally occurring polymer synthesized by bacteria. Because of its biodegradability, it has attracted much attention from medical researchers. However, the inherent brittleness impedes use of bacterial PHB as an engineering plastic. By using a nucleating agent, it is expected that the nucleation density will increase and the size of spherulites will be reduced, resulting in higher crystallization temperatures if compared with pure PHB. The crystallization behavior of poly(3-hydroxybutyrate) (PHB) induced by poly(ethylene terephthalate) (PET ) and other commercials additives as nucleating agents was investigated by differential scanning calorimetry, polarized optical microscopy and X-ray diffraction. (author)

  7. Processing and characterization of plasticized PLA/PHB blends for biodegradable multiphase systems

    Directory of Open Access Journals (Sweden)

    I. Armentano

    2015-07-01

    Full Text Available Blends of poly(lactic acid (PLA and poly(3-hydroxybutyrate (PHB plasticized with a lactic acid oligomer (OLA added at three different concentrations (15, 20 and 30 wt% by weight, were prepared by an optimized extrusion process to improve the processability and mechanical properties of these biopolymers for flexible film manufacturing. Morphological, chemical, thermal, mechanical, barrier and migration properties were investigated and formulations with desired performance in eco-friendly films were selected. The efficiency of OLA as plasticizer for PLA_PHB blends was demonstrated by the significant decrease of their glass transition temperatures and a considerable improvement of their ductile properties. The measured improvements in the barrier properties are related to the higher crystallinity of the plasticized PLA_PHB blends, while the overall migration test underlined that all the proposed formulations maintained migration levels below admitted levels. The PLA_PHB blend with 30 wt% OLA was selected as the optimum formulation for food packaging, since it offered the best compromise between ductility and oxygen and water vapor barrier properties with practically no migration.

  8. PHB/bentonite compounds: Effect of clay modification and thermal aging on properties

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Tatiara G.; Costa, Anna Raffaela M.; Canedo, Eduardo L.; Carvalho, Laura H. [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Wellen, Renate M.R., E-mail: tatiaraalmeida@gmail.com [Universidade Federal da Paraíba (UFPB), João Pessoa, PB (Brazil)

    2017-11-15

    Poly(3-hydroxybutyrate) (PHB) was compounded with three different Bentonite clays: natural, purified by ultrasound/sonicated and organically modified with hexadecyltrimethylammonium bromide. PHB/Bentonite masterbatches with 30% clay were prepared in a laboratory internal mixer and letdown with pure matrix to 1% and 3% w/w clay. Test samples were injection molded and characterized by x-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Increase in Bentonite hydrophobic character was evinced by FTIR for organoclays. XRD of composites showed increase in clay interlayer distance and peak broadening, suggesting formation of intercalated nanocomposites. DSC showed increase in crystallinity and crystallization rate for compounds, especially for PHB/organoclay formulations. Thermal aging was conducted by exposing specimens at 115 deg C for up to 120 hours, and mechanical properties were measured according to ASTM standards. Elastic modulus increased and impact strength decreased with time and clay content; clay purification had little effect on the tensile properties. Tensile strength of thermal aged samples showed little variation, except for the organoclay nanocomposites, for which it significantly decreased with exposure time. SEM images displayed a whitened honeycomb structure and detachment of PHB/Bentonite layers which may be connected to cold crystallization and degradation processes taking place during thermal aging. (author)

  9. Polyhydroxybutyrate (PHB) Synthesis by Spirulina sp. LEB 18 Using Biopolymer Extraction Waste.

    Science.gov (United States)

    da Silva, Cleber Klasener; Costa, Jorge Alberto Vieira; de Morais, Michele Greque

    2018-01-20

    The reuse of waste as well as the production of biodegradable compounds has for years been the object of studies and of global interest as a way to reduce the environmental impact generated by unsustainable exploratory processes. The conversion of linear processes into cyclical processes has environmental and economic advantages, reducing waste deposition and reducing costs. The objective of this work was to use biopolymer extraction waste in the cultivation of Spirulina sp. LEB 18, for the cyclic process of polyhydroxybutyrate (PHB) synthesis. Concentrations of 10, 15, 20, 25, and 30% (v/v) of biopolymer extraction waste were tested. For comparison, two assays were used without addition of waste, Zarrouk (SZ) and modified Zarrouk (ZM), with reduction of nitrogen. The assays were carried out in triplicate and evaluated for the production of microalgal biomass and PHB. The tests with addition of waste presented a biomass production statistically equal to ZM (0.79 g L -1 ) (p PHB in the assay containing 25% of waste was higher when compared to the other cultivations, obtaining 10.6% (w/w) of biopolymer. From the results obtained, it is affirmed that the use of PHB extraction waste in the microalgal cultivation, aiming at the synthesis of biopolymers, can occur in a cyclic process, reducing process costs and the deposition of waste, thus favoring the preservation of the environment.

  10. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor

    NARCIS (Netherlands)

    Jiang, Y.; Marang, L.; Kleerebezem, R.; Muyzer, G.; van Loosdrecht, M.C.M.

    2011-01-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the

  11. Thermal, mechanical and morphological characterization of plasticized PLA-PHB blends

    Science.gov (United States)

    A blend of poly(lactic acid) (PLA) (75% by weight) and poly(3-hydroxybutyrate) (PHB) (25% by weight) with a polyester plasticizer (Lapol 108) at two different concentrations (5 and 7% by weight per 100 parts of the blends) were investigated by TGA, DSC, XRD, SEM, mechanical testing and biodegradatio...

  12. PHB/bentonite compounds: Effect of clay modification and thermal aging on properties

    International Nuclear Information System (INIS)

    Almeida, Tatiara G.; Costa, Anna Raffaela M.; Canedo, Eduardo L.; Carvalho, Laura H.; Wellen, Renate M.R.

    2017-01-01

    Poly(3-hydroxybutyrate) (PHB) was compounded with three different Bentonite clays: natural, purified by ultrasound/sonicated and organically modified with hexadecyltrimethylammonium bromide. PHB/Bentonite masterbatches with 30% clay were prepared in a laboratory internal mixer and letdown with pure matrix to 1% and 3% w/w clay. Test samples were injection molded and characterized by x-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Increase in Bentonite hydrophobic character was evinced by FTIR for organoclays. XRD of composites showed increase in clay interlayer distance and peak broadening, suggesting formation of intercalated nanocomposites. DSC showed increase in crystallinity and crystallization rate for compounds, especially for PHB/organoclay formulations. Thermal aging was conducted by exposing specimens at 115 deg C for up to 120 hours, and mechanical properties were measured according to ASTM standards. Elastic modulus increased and impact strength decreased with time and clay content; clay purification had little effect on the tensile properties. Tensile strength of thermal aged samples showed little variation, except for the organoclay nanocomposites, for which it significantly decreased with exposure time. SEM images displayed a whitened honeycomb structure and detachment of PHB/Bentonite layers which may be connected to cold crystallization and degradation processes taking place during thermal aging. (author)

  13. Conversion of polyhydroxybutyrate (PHB) to methyl crotonate for the production of biobased monomers

    NARCIS (Netherlands)

    Spekreijse, J.; Notre, Le J.E.L.; Sanders, J.P.M.; Scott, E.L.

    2015-01-01

    Within the concept of the replacement of fossil with biobased resources, bacterial polyhydroxybutyrate (PHB) can be obtained from volatile fatt y acids (VFAs) from agro-food waste streams and used as an intermediate toward attractive chemicals. Here we address a crucial step in this process, the

  14. PENGARUH UMPAN TAMBAHAN PADA AKUMULASI POLIHIDROKSIBUTIRAT (PHB OLEH Bacillus cereus IFO 13690 MENGGUNAKAN SUBSTRAT TAPIOKA The Effects of Feeding on Accumulation of Polyhydroxybutyrate (PHB from Tapioca by Bacillus cereus IFO 13690

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    Margono Margono

    2012-05-01

    Full Text Available Bacillus cereus IFO 13690 is Gram positive bacteria that produces polyhydroxybutyrate (PHB. It has amylolytic characteristic that can be cultured using cassava starch. This research reported the ability of B. cereus IFO 13690 on accumulating PHB and the effects of starch and ammonium feeding on cell and PHB productivity. Batch process was conducted with initial starch of 18 g/l, medium pH of 5.6 and medium temperature of 30 oC. Fed batch process was conducted in the same conditions of the optimum batch process with feeding of 2.1 l/hat 7th ­7.65thhours of exponential growth and 1.86 l/hat 10th­10.8thhours of exponential growth. The feeding compositions were starch of 70 g/l and am­ monium sulfate of 20 g/l. The results of batch process showed that the highest accumulation of PHB was achieved with initial ammonium of 1.20 g/l and dissolved oxygen of 5 % air saturation. The highest PHB accumulation of 0.13 g/l was achieved after 29 hours of fermentation. It was similar to 0.005 g/l.h productivity and the PHB content was 2.42%. The productivity of cell and PHB in fed batch process was double compared to the batch process, i.e. 0.39 g/l.h and0.01 g/l.h, respectively. The PHB content in cell dry weight was relatively higher in the fed batch compared to batch process, i.e. 2.50 %. ABSTRAK Bacillus cereus IFO 13690 adalah bakteri Gram positif penghasil polihidroksibutirat(PHB yang bersifat amilolitik sehingga dapat dikulturkan dalam substrat pati. Penelitian ini dimaksudkan untuk melaporkan kemampuan B. cereus IFO 13690 dalam mengakumulasi PHB pada proses batch dan pengaruh penambahan pati serta amonium terhadap produktivitas sel dan PHB pada proses fed batch. Percobaan proses batch dilaksanakan pada konsentrasi pati awal 18 g/l, pH medium 5,6 dan suhu medium 30 oC. Percobaan proses fedbatch dilaksanakan seperti pada proses batch opti­ mum kemudian ditambahkan medium umpan pada saat pertumbuhan eksponensial, yaitu 2,1 l/jam pada saat pertum­ buhan

  15. Estudos das propriedades mecânicas e térmicas do polímero biodegradável poli-3-hidroxibutirato (PHB) e de compósitos PHB/pó de madeira.

    OpenAIRE

    Miriam Lúcia Chiquetto Machado

    2008-01-01

    O objetivo deste trabalho foi o estudo das propriedades mecânicas e térmicas do PHB e de compósitos de PHB/pó de madeira processados, reprocessados e irradiados. Foram preparados compósitos com PHB e pó de madeira com concentrações de PHB/pó de madeira de 90/10, 80/20 e 70/30 (m/m). Foram realizados ensaios de propriedades mecânicas, HDT, ponto de amolecimento Vicat, TGA e DSC. A incorporação do pó de madeira aumentou o grau de cristalinidade e a temperatura de cristalização do polímero, e no...

  16. Improved productivity of poly (3-hydroxybutyrate) (PHB) in thermophilic Chelatococcus daeguensis TAD1 using glycerol as the growth substrate in a fed-batch culture.

    Science.gov (United States)

    Cui, Bin; Huang, Shaobin; Xu, Fuqian; Zhang, Ruijian; Zhang, Yongqing

    2015-07-01

    A particularly successful polyhydroxyalkanoate (PHA) in industrial applications is poly (3-hydroxybutyrate) (PHB). However, one of the major obstacles for wider application of PHB is the cost of its production and purification. Therefore, it is desirable to discover a method for producing PHB in large quantities at a competitive price. Glycerol is a cheap and widely used carbon source that can be applied in PHB production process. There are numerous advantages to operating fermentation at elevated temperatures; only several thermophilic bacteria are able to accumulate PHB when glycerol is the growth substrate. Here, we report on the possibility of increasing PHB production at low cost using thermophilic Chelatococcus daeguensis TAD1 when glycerol is the growth substrate in a fed-batch culture. We found that (1) excess glycerol inhibited PHB accumulation and (2) organic nitrogen sources, such as tryptone and yeast extract, promoted the growth of C. daeguensis TAD1. In the batch fermentation experiments, we found that using glycerol at low concentrations as the sole carbon source, along with the addition of mixed nitrate (NH4Cl, tryptone, and yeast extract), stimulated PHB accumulation in C. daeguensis TAD1. The results showed that the PHB productivity decreased in the following order: two-stage fed-batch fermentation > fed-batch fermentation > batch fermentation. In optimized culture conditions, a PHB amount of 17.4 g l(-1) was obtained using a two-stage feeding regimen, leading to a productivity rate of 0.434 g l(-1) h(-1), which is the highest productivity rate reported for PHB to date. This high PHB biosynthetic productivity could decrease the total production cost, allowing for further development of industrial applications of PHB.

  17. Stenotrophomonas sp. RZS 7, a novel PHB degrader isolated from plastic contaminated soil in Shahada, Maharashtra, Western India.

    Science.gov (United States)

    Wani, S J; Shaikh, S S; Tabassum, B; Thakur, R; Gulati, A; Sayyed, R Z

    2016-12-01

    This paper reports an isolation and identification of novel poly-β-hydroxybutyrate (PHB) degrading bacterium Stenotrophomonas sp. RZS 7 and studies on its extracellular PHB degrading depolymerase enzyme. The bacterium isolated from soil samples of plastic contaminated sites of municipal area in Shahada, Maharashtra, Western India. It was identified as Stenotrophomonas sp. RZS 7 based on polyphasic approach. The bacterium grew well in minimal salt medium (MSM) and produced a zone (4.2 mm) of PHB hydrolysis on MSM containing PHB as the only source of nutrient. An optimum yield of enzyme was obtained on the fifth day of incubation at 37 °C and at pH 6.0. Further increase in enzyme production was recorded with Ca 2+ ions, while other metal ions like Fe 2+ (1 mM) and chemical viz. mercaptoethanol severally affected the production of enzyme.

  18. Effect of Polyhydroxybutyrate (PHB) storage on L-arginine production in recombinant Corynebacterium crenatum using coenzyme regulation.

    Science.gov (United States)

    Xu, Meijuan; Qin, Jingru; Rao, Zhiming; You, Hengyi; Zhang, Xian; Yang, Taowei; Wang, Xiaoyuan; Xu, Zhenghong

    2016-01-19

    Corynebacterium crenatum SYPA 5 is the industrial strain for L-arginine production. Poly-β-hydroxybutyrate (PHB) is a kind of biopolymer stored as bacterial reserve materials for carbon and energy. The introduction of the PHB synthesis pathway into several strains can regulate the global metabolic pathway. In addition, both the pathways of PHB and L-arginine biosynthesis in the cells are NADPH-dependent. NAD kinase could upregulate the NADPH concentration in the bacteria. Thus, it is interesting to investigate how both PHB and NAD kinase affect the L-arginine biosynthesis in C. crenatum SYPA 5. C. crenatum P1 containing PHB synthesis pathway was constructed and cultivated in batch fermentation for 96 h. The enzyme activities of the key enzymes were enhanced comparing to the control strain C. crenatum SYPA 5. More PHB was found in C. crenatum P1, up to 12.7 % of the dry cell weight. Higher growth level and enhanced glucose consumptions were also observed in C. crenatum P1. With respect to the yield of L-arginine, it was 38.54 ± 0.81 g/L, increasing by 20.6 %, comparing to the control under the influence of PHB accumulation. For more NADPH supply, C. crenatum P2 was constructed with overexpression of NAD kinase based on C. crenatum P1. The NADPH concentration was increased in C. crenatum P2 comparing to the control. PHB content reached 15.7 % and 41.11 ± 1.21 g/L L-arginine was obtained in C. crenatum P2, increased by 28.6 %. The transcription levels of key L-arginine synthesis genes, argB, argC, argD and argJ in recombinant C. crenatum increased 1.9-3.0 times compared with the parent strain. Accumulation of PHB by introducing PHB synthesis pathway, together with up-regulation of coenzyme level by overexpressing NAD kinase, enables the recombinant C. crenatum to serve as high-efficiency cell factories in the long-time L-arginine fermentation. Furthermore, batch cultivation of the engineered C. crenatum revealed that it could accumulate both extracellular L

  19. Blendas PHB/copoliésteres biodegradáveis : biodegradação em solo Biodegradable PHB/copolyester blends : biodegradation in soil

    Directory of Open Access Journals (Sweden)

    Suzan A. Casarin

    2013-01-01

    Full Text Available Este trabalho apresenta os resultados do comportamento de blendas do polímero biodegradável PHB poli(hidroxibutirato com os copoliésteres também biodegradáveis EastarBio® e Ecoflex®, na composição de 75% de PHB e 25% dos copoliésteres, em contato com solo composto simulado. Foi também avaliada a influência da adição de pó de serra ou farinha de madeira, na proporção de 70% da blenda e 30% de pó de serra (p.d.s.. A biodegradação foi avaliada para amostras após 30, 60 e 90 dias em contato com solo, através de análises gravimétricas, morfológicas e mecânicas. A preparação inicial dos grânulos dos compostos poliméricos foi feita por extrusão, utilizando uma extrusora dupla-rosca e a moldagem dos corpos de prova foi realizada através da moldagem por injeção. Os materiais estudados biodegradam nas condições testadas. A blenda PHB/EastarBio® (75/25 + 30% p.d.s. apresentou maior redução de massa, 29% após 90 dias. Notou-se que a biodegradação se inicia pela superfície do material e que 90 dias são insuficientes para observar alterações internas.This paper reports on blends made with the biodegradable polymers poly(hydroxybutyrate (PHB and Eastar Bio® or Ecoflex® copolyesters, in contact with simulated compound soil. The blends had 75% of PHB and 25% of copolyesters. We also analyzed the influence from adding 30% of powder-wood or wood flour (WPC to 70% of the blend. Biodegradation was analyzed for samples after 30, 60 and 90 days in contact with soil, through thermogravimetric, morphological and mechanical analyses. The initial preparation of the granules of polymeric compounds was made by extrusion, using a twin-screw extruder and the molding of the specimens was performed by injection molding. The analysis indicated material biodegradation under the conditions tested. The PHB/Eastar Bio® blend (75/25 + 30% WPC exhibited the highest degradation with 29% of mass loss at the end of 90 days. Biodegradation

  20. Effect of Babassu Natural Filler on PBAT/PHB Biodegradable Blends: An Investigation of Thermal, Mechanical, and Morphological Behavior

    Directory of Open Access Journals (Sweden)

    Vinicius C. Beber

    2018-05-01

    Full Text Available Blending of biodegradable polymers in combination with low-price organic fillers has proven to be a suitable approach to produce cost-effective composites in order to address pollution issues and develop products with superior mechanical properties. In the present research work PBAT/PHB/Babassu composites with 25, 50, and 75% of each polymer and 20% of Babassu were produced by melting extrusion. Their thermal, mechanical, and morphological behavior was investigated by differential scanning calorimetry (DSC, tensile testing, and scanning electron microscopy (SEM. Blending PBAT with PHB inhibited the crystallization of both polymers whereas adding Babassu did not significantly change their melting behaviour. Incorporation of Babassu reduced the tensile strength of its respective blends between 4.8 and 32.3%, and elongation at break between 26.0 and 66.3%. PBAT as highly ductile and low crystalline polymer may be seen as a crystallization tool control for PHB as well as a plasticizer to PBAT/PHB blends and PBAT/PHB/Babassu composites. As PBAT content increases: (i elongation at break increases and (ii surface fracture becomes more refined indicating the presence of more energy dissipation mechanisms. As PBAT/PHB/Babassu composites are biodegradable, environmental friendly, and cost effective, products based on these compounds have a great potential since their mechanical properties such as ductility, stiffness, and tensile strength are still suitable for several applications even at lower temperatures (−40 °C.

  1. Model-based intensification of a fed-batch microbial process for the maximization of polyhydroxybutyrate (PHB) production rate.

    Science.gov (United States)

    Penloglou, Giannis; Vasileiadou, Athina; Chatzidoukas, Christos; Kiparissides, Costas

    2017-08-01

    An integrated metabolic-polymerization-macroscopic model, describing the microbial production of polyhydroxybutyrate (PHB) in Azohydromonas lata bacteria, was developed and validated using a comprehensive series of experimental measurements. The model accounted for biomass growth, biopolymer accumulation, carbon and nitrogen sources utilization, oxygen mass transfer and uptake rates and average molecular weights of the accumulated PHB, produced under batch and fed-batch cultivation conditions. Model predictions were in excellent agreement with experimental measurements. The validated model was subsequently utilized to calculate optimal operating conditions and feeding policies for maximizing PHB productivity for desired PHB molecular properties. More specifically, two optimal fed-batch strategies were calculated and experimentally tested: (1) a nitrogen-limited fed-batch policy and (2) a nitrogen sufficient one. The calculated optimal operating policies resulted in a maximum PHB content (94% g/g) in the cultivated bacteria and a biopolymer productivity of 4.2 g/(l h), respectively. Moreover, it was demonstrated that different PHB grades with weight average molecular weights of up to 1513 kg/mol could be produced via the optimal selection of bioprocess operating conditions.

  2. Genetic Algorithmic Optimization of PHB Production by a Mixed Culture in an Optimally Dispersed Fed-batch Bioreactor

    Directory of Open Access Journals (Sweden)

    Pratap R. Patnaik

    2009-10-01

    Full Text Available Poly-β-hydroxybutyrate (PHB is an energy-storage polymer whose properties are similar to those of chemical polymers such as polyethylene and polypropylene. Moreover, PHB is biodegradable, absorbed by human tissues and less energy-consuming than synthetic polymers. Although Ralstonia eutropha is widely used to synthesize PHB, it is inefficient in utilizing glucose and similar sugars. Therefore a co-culture of R. eutropha and Lactobacillus delbrueckii is preferred since the latter can convert glucose to lactate, which R. eutropha can metabolize easily. Tohyama et al. [24] maximized PHB production in a well-mixed fed-batch bioreactor with glucose and (NH42SO4 as the primary substrates. Since production-scale bioreactors often deviate from ideal laboratory-scale reactors, a large bioreactor was simulated by means of a dispersion model with the kinetics determined by Tohyama et al. [24] and dispersion set at an optimum Peclet number of 20 [32]. The time-dependent feed rates of the two substrates were determined through a genetic algorithm (GA to maximize PHB production. This bioreactor produced 22.2% more PHB per liter and 12.8% more cell mass than achieved by Tohyama et al. [24]. These results, and similar observations with other fermentations, indicate the feasibility of enhancing the efficiency of large nonideal bioreactors through GA optimizations.

  3. Low Density Polyethylene (LDPE blends based on Poly(3-Hydroxi-Butyrate (PHB and Guar Gum (GG biodegradable polymers

    Directory of Open Access Journals (Sweden)

    Marisa Cristina Guimarães Rocha

    2015-02-01

    Full Text Available LDPE blends based on PHB and GG biodegradable polymers were prepared by melt mixing in a twin screw extruder. The mechanical properties of the materials were evaluated. Preliminary information about the biodegradation behavior of the specimens was obtained by visual observation of samples removed from the simulated soil in 90 days. The results indicated that LDPE/PHB blends may be used for designing LDPE based materials with increased susceptibility to degradation, if elongation at break and impact properties are not determinant factors of their performance. LDPE based materials on GG present values of flexural and mechanical strength lower than those of LDPE/PHB blends. LDPE/PHB/GG blends exhibit unsatisfactory properties. Apparently, the effect of addition of GG to LDPE on the biodegradation behavior of LDPE/GG blends was less intense than the effect caused by addition of PHB to the blends. Similar observation has occurred with the partial replacement of GG by PHB in the ternary blends.

  4. Biosynthesis of poly(3-hydroxybutyrate) (PHB) by Cupriavidus necator H16 from jatropha oil as carbon source.

    Science.gov (United States)

    Batcha, Abeed Fatima Mohidin; Prasad, D M Reddy; Khan, Maksudur R; Abdullah, Hamidah

    2014-05-01

    Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer that can be synthesized through bacterial fermentation. In this study, Cupriavidus necator H16 is used to synthesize PHB by using Jatropha oil as its sole carbon source. Different variables mainly jatropha oil and urea concentrations, and agitation rate were investigated to determine the optimum condition for microbial fermentation in batch culture. Based on the results, the highest cell dry weight and PHB concentrations of 20.1 and 15.5 g/L, respectively, were obtained when 20 g/L of jatropha oil was used. Ethanol was used as external stress factor and the addition of 1.5 % ethanol at 38 h had a positive effect with a high PHB yield of 0.987 g PHB/g jatropha oil. The kinetic studies for cell growth rate and PHB production were conducted and the data were fitted with Logistic and Leudeking–Piret models. The rate constants were evaluated and the theoretical values were in accordance with the experimental data obtained

  5. Biosynthesis of poly-3-hydroxybutyrate (PHB) from glycerol by Paracoccus denitrificans in a batch bioreactor: effect of process variables.

    Science.gov (United States)

    Kalaiyezhini, D; Ramachandran, K B

    2015-01-01

    In this study, the kinetics of poly-3-hydroxybutyrate (PHB) biosynthesis from glycerol by Paracoccus denitrificans DSMZ 413 were explored in a batch bioreactor. Effects of inorganic and organic nitrogen source, carbon to nitrogen ratio, and other process variables such as pH, aeration, and initial glycerol concentration on PHB production were investigated in a 2.5-L bioreactor. Yeast extract was found to be the best nitrogen source compared to several organic nitrogen sources tested. At pH 6, specific growth rate, product formation rate, and accumulation of PHB within the cell were maximum. Specific growth rate increased with increase in oxygen transfer rate, but moderate oxygen transfer rate promoted PHB production. High glycerol concentration inhibited specific product formation rate but not growth. High initial carbon/nitrogen (C/N) ratio favored PHB accumulation and its productivity. At a C/N ratio of 21.4 (mol mol(-1)), 10.7 g L(-1) of PHB corresponding to 72% of cell dry weight was attained.

  6. Reprocessability of PHB in extrusion: ATR-FTIR, tensile tests and thermal studies

    Directory of Open Access Journals (Sweden)

    Leonardo Fábio Rivas

    Full Text Available Abstract Mechanical recycling of biodegradable plastics has to be encouraged, since the consumption of energy and raw materials can be reduced towards a sustainable development in plastics materials. In this study, the evolution of thermal and mechanical properties, as well as structural changes of poly(hydroxybutyrate (PHB up to three extrusion cycles were investigated. Results indicated a significant reduction in mechanical properties already at the second extrusion cycle, with a reduction above 50% in the third cycle. An increase in the crystallinity index was observed due to chemicrystallization process during degradation by chain scission. On the other hand, significant changes in the chemical structure or in thermal stability of PHB cannot be detected by Fourier transform infrared spectroscopy (FTIR and thermogravimetric analyses (TGA, respectively.

  7. Effect of ageing time on mechanical properties of plasticized poly(hydroxybutyrate) (PHB)

    Science.gov (United States)

    Farris, Giuseppe; Cinelli, Patrizia; Anguillesi, Irene; Salvadori, Sara; Coltelli, Maria-Beatrice; Lazzeri, Andrea

    2014-05-01

    Polyhydroxybutyrate (PHB) based materials were prepared by melt extrusion by using different plasticizers, such as poly(ethylene glycol)s (PEG)s having different molecular weight (400, 1500 and 4000). The plasticizers content was varied in the range 10-20% by weight versus the PHB polymeric matrix. The variation of tensile properties of the different samples was monitored as a function of time of ageing to study the stability of the material. The elastic modulus and tensile strength increased as a function of time, whereas the strain at break decreased. The experimental results were explained by considering both the demixing of the plasticizers and the occurring of secondary crystallization. Moreover the variation in mechanical properties was correlated to the structure and concentration of the different plasticizers employed.

  8. PHB, crystalline and amorphous magnesium alloys: Promising candidates for bioresorbable osteosynthesis implants?

    International Nuclear Information System (INIS)

    Celarek, Anna; Kraus, Tanja; Tschegg, Elmar K.; Fischerauer, Stefan F.; Stanzl-Tschegg, Stefanie; Uggowitzer, Peter J.; Weinberg, Annelie M.

    2012-01-01

    In this study various biodegradable materials were tested for their suitability for use in osteosynthesis implants, in particular as elastically stable intramedullary nails for fracture treatment in paediatric orthopaedics. The materials investigated comprise polyhydroxybutyrate (PHB), which belongs to the polyester family and is produced by microorganisms, with additions of ZrO 2 and a bone graft substitute; two crystalline magnesium alloys with significantly different degradation rates ZX50 (MgZnCa, fast) and WZ21 (MgYZnCa, slow); and MgZnCa bulk metallic glasses (BMG). Push-out tests were conducted after various implantation times in rat femur meta-diaphysis to evaluate the shear forces between the implant material and the bone. The most promising materials are WZ21 and BMG, which exhibit high shear forces and push-out energies. The degradation rate of ZX50 is too fast and thus the alloy does not maintain its mechanical stability long enough during the fracture-healing period. PHB exhibits insufficient mechanical properties: it degrades very slowly and the respective low shear forces and push-out energy levels are unsatisfactory. - Highlights: ► In-vivo (rat model) investigation of biodegradable materials suitable for ESIN. ► Materials: polymer PHB, crystalline Mg ZX50 and Mg WZ21, MgZnCa bulk metallic glasses. ► Evaluated interface shear strength, push-out energies, stiffness, histology. ► Mg WZ21 suitable, other materials only after alterations.

  9. Structural and morphological studies on poly(3-hydroxybutyrate acid) (PHB)/chitosan drug releasing microspheres prepared by both single and double emulsion processes

    Energy Technology Data Exchange (ETDEWEB)

    Shih, W.-J. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Chen, Y.-H. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-kung Road, Kaohsiung 80782, Taiwan (China); Shih, C.-J. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, No. 100, Shih-Chuang 1st Rd., Sanmin District, Kaohsiung 80708, Taiwan (China); Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Dayeh University, 112 Shan-Jiau Road, Da-Tsuen, Changhua 515, Taiwan (China); Wang, M.-C. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-kung Road, Kaohsiung 80782, Taiwan (China) and Department of Materials Science and Engineering, National United University, 1 Lien-Da Road, Kung-ching Li, Miao Li 360, Taiwan (China)]. E-mail: mcwang@cc.kuas.edu.tw

    2007-05-31

    Drug releasing microspheres of poly(3-hydroxybutyric acid)/chitosan (PHB/CTS) with various compositions have been synthesized by both single and double emulsion methods, and collected by a freeze-drying process. In this study, gentamicin was used as an antibacterial medicine coated with PHB. The PHB/CTS microspheres of various compositions prepared by a single emulsion process (SEP) were identified as the major PHB phase together with a minor unknown Phase X by X-ray diffraction (XRD) and FT-IR. However, in the microspheres prepared using a double emulsion process (DEP) the dominant Phase was X and the minor phase was PHB. The size of the PHB/CTS microspheres prepared by SEP increased with the PHB/CTS ratio from 1 {mu}m for 1:1 to 2 {mu}m for 5:1. However, the size of the PHB/CTS microspheres prepared by DEP decreased with the PHB/CTS ratio from 1 {mu}m for 1:1 to 800 nm for 5:1.

  10. Structural and morphological studies on poly(3-hydroxybutyrate acid) (PHB)/chitosan drug releasing microspheres prepared by both single and double emulsion processes

    International Nuclear Information System (INIS)

    Shih, W.-J.; Chen, Y.-H.; Shih, C.-J.; Hon, M.-H.; Wang, M.-C.

    2007-01-01

    Drug releasing microspheres of poly(3-hydroxybutyric acid)/chitosan (PHB/CTS) with various compositions have been synthesized by both single and double emulsion methods, and collected by a freeze-drying process. In this study, gentamicin was used as an antibacterial medicine coated with PHB. The PHB/CTS microspheres of various compositions prepared by a single emulsion process (SEP) were identified as the major PHB phase together with a minor unknown Phase X by X-ray diffraction (XRD) and FT-IR. However, in the microspheres prepared using a double emulsion process (DEP) the dominant Phase was X and the minor phase was PHB. The size of the PHB/CTS microspheres prepared by SEP increased with the PHB/CTS ratio from 1 μm for 1:1 to 2 μm for 5:1. However, the size of the PHB/CTS microspheres prepared by DEP decreased with the PHB/CTS ratio from 1 μm for 1:1 to 800 nm for 5:1

  11. Microbial production, ultrasound-assisted extraction and characterization of biopolymer polyhydroxybutyrate (PHB) from terrestrial (P. hysterophorus) and aquatic (E. crassipes) invasive weeds.

    Science.gov (United States)

    Pradhan, Sushobhan; Borah, Arup Jyoti; Poddar, Maneesh Kumar; Dikshit, Pritam Kumar; Rohidas, Lilendar; Moholkar, Vijayanand S

    2017-10-01

    This study reports synthesis of biodegradable poly(3-hydroxybutyrate) (PHB) polymer from two invasive weeds, viz. P. hysterophorus and E. crassipes. The pentose and hexose-rich hydrolyzates obtained from acid pretreatment and enzymatic hydrolysis of two biomasses were separately fermented using Ralstonia eutropha MTCC 8320 sp. PHB was extracted using sonication and was characterized using FTIR, 1 H and 13 C NMR and XRD. PHB content of dry cell mass was 8.1-21.6% w/w, and the PHB yield was 6.85×10 -3 -36.41×10 -3 % w/w raw biomass. Thermal properties of PHB were determined by TGA, DTG and DSC analysis. PHB obtained from pentose-hydrolyzate had glass transition temperatures of 6°-9°C, while PHB from hexose-rich hydrolyzate had maximum thermal degradation temperatures of 370°-389°C. These thermal properties were comparable to the properties of commercial PHB. Probable causes leading to differences in thermal properties of pentose and hexose-derived PHB are: extent of crystallinity and presence of impurity in the polymer matrix. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Modifications induced by swift heavy ions on poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly(ε-caprolactone) (PCL). Part 2. Radicals characterization

    International Nuclear Information System (INIS)

    Rouxhet, L.; Mestdagh, M.; Legras, R.

    2000-01-01

    Modifications induced by different energetic heavy ions ( 40 Ar 9+ , 80 Kr 15+ , 129 Xe 24+ , 208 Pb 53+ and 208 Pb 56+ ) on poly(ε-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by electron spin resonance (ESR). Indeed, film irradiation by heavy ions leads to, among other phenomena, the formation of radicals in the ion tracks. Thanks to ESR, it is possible to detect these radicals and to identify them or at least to characterize them by following the evolution of the radical signal as a function of parameters, like temperature, or the kinetic of disappearance of the radical species at ambient temperature in vacuum or ambient atmosphere. This study confirmed the generation of radicals by the irradiation of PHB/HV samples with energetic heavy ions reported in the literature. The study on PCL was not pursued after a few preliminary studies, revealing the presence of an ESR signal in the non-irradiated sample. Electronic stopping power has a major influence on radical decrease at ambient temperature. The ion used for the irradiation did not modify very much the radical signal and the evolution of the radicalar signal intensity with temperature. Different reasoning and experiments revealed that the glass transition temperature is a key temperature above which irreversible recombinations of the most stable radicals take place. A simulation study indicated that the most stable radical produced was probably a tertiary radical formed by the stabilization of the secondary radical resulting from the abstraction of a highly mobile hydrogen adjacent to the carbonyl

  13. Direct Production of Propene from the Thermolysis of Poly(β-hydroxybutyrate) (PHB). An Experimental and DFT Investigation.

    Science.gov (United States)

    Clark, Jared M; Pilath, Heidi M; Mittal, Ashutosh; Michener, William E; Robichaud, David J; Johnson, David K

    2016-01-28

    We demonstrate a synthetic route toward the production of propene directly from poly(β-hydroxybutyrate) (PHB), the most common of a wide range of high-molecular-mass microbial polyhydroxyalkanoates. Propene, a major commercial hydrocarbon, was obtained from the depolymerization of PHB and subsequent decarboxylation of the crotonic acid monomer in good yields (up to 75 mol %). The energetics of PHB depolymerization and the gas-phase decarboxylation of crotonic acid were also studied using density functional theory (DFT). The average activation energy for the cleavage of the R'C(O)O-R linkage is calculated to be 163.9 ± 7.0 kJ mol(-1). Intramolecular, autoacceleration effects regarding the depolymerization of PHB, as suggested in some literature accounts, arising from the formation of crotonyl and carboxyl functional groups in the products could not be confirmed by the results of DFT and microkinetic modeling. DFT results, however, suggest that intermolecular catalysis involving terminal carboxyl groups may accelerate PHB depolymerization. Activation energies for this process were estimated to be about 20 kJ mol(-1) lower than that for the noncatalyzed ester cleavage, 144.3 ± 6.4 kJ mol(-1). DFT calculations predict the decarboxylation of crotonic acid to follow second-order kinetics with an activation energy of 147.5 ± 6.3 kJ mol(-1), consistent with that measured experimentally, 146.9 kJ mol(-1). Microkinetic modeling of the PHB to propene overall reaction predicts decarboxylation of crotonic acid to be the rate-limiting step, consistent with experimental observations. The results also indicate that improvements made to enhance the isomerization of crotonic acid to vinylacetic acid will improve the direct conversion of PHB to propene.

  14. Blends of PHB/PEG: obtention of matrices for use as controlled drug release systems; Obtencao de blendas de PHB/PEG para matrizes de sistemas micro e nanoestruturados visando aplicacao em liberacao controlada de farmacos

    Energy Technology Data Exchange (ETDEWEB)

    Catoni, S.E.M.; Gomes, C.A.T.; Trindade, K.N.S.; Schneider, A.L.S.; Pezzin, A.P.T., E-mail: sara.elisamoreira@hotmail.co [Universidade da Regiao de Joinville (UNIVILLE), SC (Brazil); Soldi, V. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2010-07-01

    Different materials have been used in the development of micro-and nanostructured systems for drug release. In general, poly(3-hydroxybutyrate) (PHB) matrixes have high crystallinity degree, justifying its slow degradation. This feature makes the attack of enzymes more difficult. Thus, the surface modification with hydrophilic polymers such as poly(ethylene glycol) (PEG) has been investigated in order to obtain particles which are not recognized and captured by phagocytic cells after in vivo administration, staying for a longer in the systemic circulation. In this work, PHB/PEG films were prepared by casting in different proportions and characterized by XRD, DSC, SEM, GPC and TGA. The films presented high crystallinity degree and showed uniformity, except the 50/50 composition which showed the presence of two phases. The results revealed that increasing percentage of PEG, the Tm of PHB was decreased, the thermal stability was dramatically decreased and molecular weight of the samples was lower. (author)

  15. Influence of nutritional and physicochemical variables on PHB production from raw glycerol obtained from a Colombian biodiesel plant by a wild-type Bacillus megaterium strain.

    Science.gov (United States)

    Moreno, Paalo; Yañez, Camilo; Cardozo, Nilo Sérgio Medeiros; Escalante, Humberto; Combariza, Marianny Y; Guzman, Carolina

    2015-12-25

    Biodegradable polymers are currently viable alternatives to traditional synthetic polymers. For instance, polyhydroxybutyrate (PHB) is intracellularly produced and accumulated by Bacillus species, among others. This study reports several wild-type Bacillus strains with the ability to accumulate PHB using raw glycerol from biodiesel production as the sole carbon source. Out of 15 strains from different sources, B. megaterium B2 was selected as the most promising strain for further statistical optimization of the medium composition. Plackett-Burman and central composite designs were used to establish key variables and optimal culture conditions for PHB production using both 250-mL shake flasks and a 7.5-L bioreactor. Temperature and concentrations of glycerol and Na2HPO4 are the experimental variables with the most significant influence on PHB production by B2. After 14 hours of fermentation in shake flasks with optimized medium, B2 produced 0.43 g/L of PHB with a 34% accumulation in the cells. In contrast, under the same conditions, a maximum PHB concentration of 1.20 g/L in the bioreactor was reached at 11 hours. These values correspond to a 48% and 314% increase in PHB production compared to the initial culture conditions. These results suggest the potential of B2 as a PHB producer using raw glycerol, which is an inexpensive, abundant and readily available carbon source. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Mobilities Mobilities

    Directory of Open Access Journals (Sweden)

    César Pompeyo

    2011-12-01

    Full Text Available Urry, John (2007 Mobilities.Oxford: Polity Press.Urry, John (2007 Mobilities.Oxford: Polity Press.John Urry (1946-, profesor en la Universidad de Lancaster, es un sociólogo de sobra conocido y altamente reputado en el panorama internacional de las ciencias sociales. Su dilatada carrera, aparentemente dispersa y diversificada, ha seguido senderos bastante bien definidos dejando tras de sí un catálogo extenso de obras sociológicas de primer nivel. Sus primeros trabajos se centraban en el campo de la teoría social y la filosofía de las ciencias sociales o de la sociología del poder [...

  17. PHB, crystalline and amorphous magnesium alloys: Promising candidates for bioresorbable osteosynthesis implants?

    Energy Technology Data Exchange (ETDEWEB)

    Celarek, Anna [Institute for Building Construction and Technology E-206-4, Vienna University of Technology, Karlsplatz 13, 1040 Vienna (Austria); Kraus, Tanja [Department of Paediatric Orthopaedics, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Tschegg, Elmar K., E-mail: elmar.tschegg@tuwien.ac.at [Institute for Building Construction and Technology E-206-4, Vienna University of Technology, Karlsplatz 13, 1040 Vienna (Austria); Fischerauer, Stefan F. [Department of Paediatric and Adolescent Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria); Stanzl-Tschegg, Stefanie [Department of Material Sciences and Process Engineering, Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Peter Jordan Str. 82, 1190 Vienna (Austria); Uggowitzer, Peter J. [Department of Materials, Laboratory for Metal Physics and Technology, ETH Zurich, 8093 Zurich (Switzerland); Weinberg, Annelie M. [Department of Paediatric and Adolescent Surgery, Medical University of Graz, Auenbruggerplatz 34, 8036 Graz (Austria)

    2012-08-01

    In this study various biodegradable materials were tested for their suitability for use in osteosynthesis implants, in particular as elastically stable intramedullary nails for fracture treatment in paediatric orthopaedics. The materials investigated comprise polyhydroxybutyrate (PHB), which belongs to the polyester family and is produced by microorganisms, with additions of ZrO{sub 2} and a bone graft substitute; two crystalline magnesium alloys with significantly different degradation rates ZX50 (MgZnCa, fast) and WZ21 (MgYZnCa, slow); and MgZnCa bulk metallic glasses (BMG). Push-out tests were conducted after various implantation times in rat femur meta-diaphysis to evaluate the shear forces between the implant material and the bone. The most promising materials are WZ21 and BMG, which exhibit high shear forces and push-out energies. The degradation rate of ZX50 is too fast and thus the alloy does not maintain its mechanical stability long enough during the fracture-healing period. PHB exhibits insufficient mechanical properties: it degrades very slowly and the respective low shear forces and push-out energy levels are unsatisfactory. - Highlights: Black-Right-Pointing-Pointer In-vivo (rat model) investigation of biodegradable materials suitable for ESIN. Black-Right-Pointing-Pointer Materials: polymer PHB, crystalline Mg ZX50 and Mg WZ21, MgZnCa bulk metallic glasses. Black-Right-Pointing-Pointer Evaluated interface shear strength, push-out energies, stiffness, histology. Black-Right-Pointing-Pointer Mg WZ21 suitable, other materials only after alterations.

  18. Characterization of poly-hydroxybutyrate-hydroxyvalerate (PHB-HV)/corn starch blend films

    OpenAIRE

    Reis, Kelen Cristina dos

    2014-01-01

    Blendas de polihidroxibutirato-hidroxivalerato (PHB-HV) com amido de milho em diferentes concentrações foram preparadas pelo processo "casting" com clorofórmio. As propriedades mecânica, térmica, morfológica e físico-química das blendas foram investigadas usando as análises de textura, calorimetria diferencial de varredura, espectroscopia no infra-vermelho com transformada de Fourier, difração de raio-X, microscopia ótica, microscopia eletrônica de varredura e colorimetria. As propriedades me...

  19. Selection of potent bacterial strain for over-production of PHB by using low cost carbon source for eco-friendly bioplastics

    Directory of Open Access Journals (Sweden)

    Rahat Abdul Rehman

    2015-11-01

    Full Text Available Background: The microbial PHB production is a promising tool for the plastic industry for the synthesis of environmental friendly, biodegradable plastic in contrast to the conventional petro-chemical based non-degradable plastics. The selection of potent bacterial strains, inexpensive carbon source, efficient fermentation and recovery processes are important aspects that were taken into account during this study. Methods: Different bacterial strains i.e. Bacillus Spp, P. putida and P. fluorescens were screened for maximum PHB production. Under media optimization, various carbon and nitrogen sources (alone or in combination were used to achieve the maximum PHB production. Finally the degradation tests of the PHB sheet were also performed to test its biodegradability potential. Results: Shake flask studies have shown the PHB concentrations upto 7.02, 4.50 and 34.4 mg/g of dry cell mass of P. putida, P. fluorescens and Bacillus Spp. respectively. Almost same results were observed at laboratory scale production of PHB in 10 L fermenter i.e. 6.28, 6.23 and 39.5 mg/g of dry cell mass by P. putida, P. fluorescens and Bacillus Spp. respectively. On the basis of these observations, Bacillus Spp. was chosen for laboratory scale PHB production. Corn steep liquor (4% was chosen as the best medium to achieve the highest PHB contents. Isolated PHB has shown biodegradation in soil up to 86.7% at 37oC. Conclusion: The Bacillus Spp. Proved to be the best strain for PHB production on only 4% CSL which is cheapest and easily available.

  20. Generation of poly-β-hydroxybutyrate from acetate in higher plants: Detection of acetoacetyl CoA reductase- and PHB synthase- activities in rice.

    Science.gov (United States)

    Tsuda, Hirohisa; Shiraki, Mari; Inoue, Eri; Saito, Terumi

    2016-08-20

    It has been reported that Poly-β-hydroxybutyrate (PHB) is generated from acetate in the rice root. However, no information is available about the biosynthetic pathway of PHB from acetate in plant cells. In the bacterium Ralstonia eutropha H16 (R. eutropha), PHB is synthesized from acetyl CoA by the consecutive reaction of three enzymes: β-ketothiolase (EC: 2.3.1.9), acetoacetyl CoA reductase (EC: 1.1.1.36) and PHB synthase (EC: 2.3.1.-). Thus, in this study, we examined whether the above three enzymatic activities were also detected in rice seedlings. The results clearly showed that the activities of the above three enzymes were all detected in rice. In particular, the PHB synthase activity was detected specifically in the sonicated particulate fractions (2000g 10min precipitate (ppt) and the 8000g 30min ppt) of rice roots and leaves. In addition to these enzyme activities, several new experimental results were obtained on PHB synthesis in higher plants: (a) (14)C-PHB generated from 2-(14)C-acetate was mainly localized in the 2000g 10min ppt and the 8000g 30min ppt of rice root. (b) Addition of acetate (0.1-10mM) to culture medium of rice seedlings did not increase the content of PHB in the rice root or leaf. (c) In addition to C3 plants, PHB was generated from acetate in a C4 plant (corn) and in a CAM plant (Bryophyllum pinnatum). d) Washing with ethylenediaminetetraacetic acid (EDTA) strongly suggested that the PHB synthesized from acetate was of plant origin and was not bacterial contamination. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. PRODUCCIÓN DE POLI-β -HIDROXIBUTIRATO (PHB β POR Ralstonia eutropha ATCC 17697

    Directory of Open Access Journals (Sweden)

    Barbosa Marcela

    2005-06-01

    Full Text Available Ralstonia eutropha es la bacteria más utilizada en la producción de poli-β-hidroxibutirato (PHB por su capacidad de acumular polímero hasta en un 80% de su peso seco. En el presente trabajo se realizaron fermentaciones por lote alimentado en dos etapas a escala 3 litros usando tres concentraciones de fructosa (5, 10 y 15 g/l. En la primera etapa, manteniendo constante la relación carbono-nitrógeno en 6.85 g C/g N, se buscó obtener una alta concentración celular; en la segunda etapa las células obtenidas se limitaron en la fuente de nitrógeno para permitir la acumulación del biopolímero. La mejor concentración para producir el material es 5 g/l en la cual se obtuvo un porcentaje de acumulación del 66.2%, una velocidad de crecimiento específico inicial de 0.5171 h-1 y una productividad de 0.1245 g PHB/ l h.

  2. Evaluation of PHB/Clay nanocomposite by spin-lattice relaxation time

    Directory of Open Access Journals (Sweden)

    Mariana Bruno

    2008-12-01

    Full Text Available Poly(3-hydroxybutyrate (PHB based on nanocomposites containing different amounts of a commercial organically modified clay (viscogel B7 were prepared employing solution intercalation method. Three solvents, such as: CHCl3, dimethylchloride (DMC and tetrahydrofuran (THF were used. The relationship among the processing conditions; molecular structure and intermolecular interaction, between both nanocomposite components, were investigated using a nuclear magnetic resonance (NMR, as a part of characterization methodology, which has been used by Tavares et al. It involves the hydrogen spin-lattice relaxation time, T1H, by solid state nuclear magnetic resonance, employing low field NMR. X ray diffraction was also employed because it is a conventional technique, generally used to obtain the first information on nanocomposite formation. Changes in PHB crystallinity were observed after the organophilic nanoclay had been incorporated in the polymer matrix. These changes, in the microstructure, were detected by the variation of hydrogen nuclear relaxation time values and by X ray, which showed an increase in the clay interlamelar space due to the intercalation of the polymer in the clay between lamellae. It was also observed, for both techniques, that the solvents affect directly the organization of the crystalline region, promoting a better intercalation, considering that they behave like a plasticizer.

  3. Production of polyhydroxybutyrate in oil palm (Elaeis guineensis Jacq. mediated by microprojectile bombardment of PHB biosynthesis genes into embryogenic calli

    Directory of Open Access Journals (Sweden)

    Ahmad Parveez eGhulam Kadir

    2015-08-01

    Full Text Available Biodegradable plastics, mainly polyhydroxybutyrate (PHB, which are traditionally produced by bacterial cells, have been produced in the cells of more than 15 plant species. Since the production of biodegradable plastics and the synthesis of oil in plants share the same substrate, acetyl-coenzyme A (acetyl-CoA, producing PHB in oil bearing crops, such as oil palm, will be advantageous. In this study, three bacterial genes, bktB, phaB and phaC, which are required for the synthesis of PHB and selectable marker gene, bar, for herbicide Basta resistant, were transformed into embryogenic calli. A number of transformed embryogenic lines resistant to herbicide Basta were obtained and were later regenerated to produce few hundred plantlets. Molecular analyses, including PCR, Southern blot and real-time PCR have demonstrated stable integration and expression of the transgenes in the oil palm genome. HPLC and Nile Blue A staining analyses confirmed the synthesis of PHB in some of the plantlets.

  4. A probiotic Bacillus strain containing amorphous poly-beta-hydroxybutyrate (PHB) stimulates the innate immune response of Penaeus monodon postlarvae.

    Science.gov (United States)

    Laranja, Joseph Leopoldo Q; Amar, Edgar C; Ludevese-Pascual, Gladys L; Niu, Yufeng; Geaga, Mary Joy; De Schryver, Peter; Bossier, Peter

    2017-09-01

    In this study, the PHB-accumulating Bacillus sp. JL47 strain (capable of accumulating 55% PHB on cell dry weight) was investigated for its effects on the immune response of giant tiger shrimp (Penaeus monodon) postlarvae (PL) before and after the Vibrio campbellii challenge. Briefly, shrimp PL were cultured and fed with Artemia nauplii enriched with Bacillus sp. JL47. Shrimp receiving the Artemia nauplii without JL47 enrichment were used as control. After 15 days of feeding, the shrimp were challenged with pathogenic V. campbellii LMG 21363 at 10 6  cells mL -1 by immersion. Relative expression of the immune related genes encoding for prophenoloxidase (proPO), transglutaminase (TGase) and heat shock protein 70 (Hsp70) in the shrimp were measured before (0 h) and after (3, 6, 9, 12, 24 h) the Vibrio challenge by quantitative real-time PCR using β-actin as the reference gene. The expressions of TGase and proPO were significantly up-regulated (p PHB-accumulating Bacillus sp. JL47 in shrimp was due to its capacity to stimulate the innate immune related genes of the shrimp, specifically the proPO and TGase genes. The application of probiotic Bacillus species, capable of accumulating a significant amount of PHB, is suggested as potential immunostimulatory strategy for aquaculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Production of polyhydroxybutyrate in oil palm (Elaeis guineensis Jacq.) mediated by microprojectile bombardment of PHB biosynthesis genes into embryogenic calli

    Science.gov (United States)

    Parveez, Ghulam Kadir Ahmad; Bahariah, Bohari; Ayub, Nor Hanin; Masani, Mat Yunus Abdul; Rasid, Omar Abdul; Tarmizi, Ahmad Hashim; Ishak, Zamzuri

    2015-01-01

    Biodegradable plastics, mainly polyhydroxybutyrate (PHB), which are traditionally produced by bacterial cells, have been produced in the cells of more than 15 plant species. Since the production of biodegradable plastics and the synthesis of oil in plants share the same substrate, acetyl-coenzyme A (acetyl-CoA), producing PHB in oil bearing crops, such as oil palm, will be advantageous. In this study, three bacterial genes, bktB, phaB, and phaC, which are required for the synthesis of PHB and selectable marker gene, bar, for herbicide Basta resistant, were transformed into embryogenic calli. A number of transformed embryogenic lines resistant to herbicide Basta were obtained and were later regenerated to produce few hundred plantlets. Molecular analyses, including polymerase chain reaction (PCR), Southern blot, and real-time PCR have demonstrated stable integration and expression of the transgenes in the oil palm genome. HPLC and Nile blue A staining analyses confirmed the synthesis of PHB in some of the plantlets. PMID:26322053

  6. Model Study To Assess Softwood Hemicellulose Hydrolysates as the Carbon Source for PHB Production in Paraburkholderia sacchari IPT 101.

    Science.gov (United States)

    Dietrich, Karolin; Dumont, Marie-Josée; Schwinghamer, Timothy; Orsat, Valérie; Del Rio, Luis F

    2018-01-08

    Softwood hemicellulose hydrolysates are a cheap source of sugars that can be used as a feedstock to produce polyhydroxybutyrates (PHB), which are biobased and compostable bacterial polyesters. To assess the potential of the hemicellulosic sugars as a carbon source for PHB production, synthetic media containing softwood hemicellulose sugars (glucose, mannose, galactose, xylose, arabinose) and the potentially inhibitory lignocellulose degradation products (acetic acid, 5-hydroxymethylfurfural (HMF), furfural, and vanillin) were fermented with the model strain Paraburkholderia sacchari IPT 101. Relative to pure glucose, individual fermentation for 24 h with 20 g/L mannose or galactose exhibited maximum specific growth rates of 97% and 60%, respectively. On the other hand, with sugar mixtures of glucose, mannose, galactose, xylose, and arabinose, the strain converted all sugars simultaneously to reach a maximum PHB concentration of 5.72 g/L and 80.5% PHB after 51 h. The addition of the inhibitor mixture at the following concentration, sodium acetate (2.11 g/L), HMF (0.67 g/L), furfural (0.66 g/L), and vanillin (0.93 g/L), to the sugar mixture stopped the growth entirely within 24 h. Individually, the inhibitors either had no effect or only reduced growth. Moreover, it was found that a bacterial inoculum with high initial cell density (optical density, OD ≥ 5.6) could overcome the growth inhibition to yield an OD of 13 within 24 h. Therefore, softwood hemicellulose sugars are viable carbon sources for PHB production. Nevertheless, real softwood hemicellulose hydrolysates need detoxification or a high inoculum to overcome inhibitory effects and allow bacterial growth.

  7. Evaluation of biodegradation of bionanocomposites of PHB/PP-g-MA/vermiculite; Avaliacao da biodegradacao de bionanocompositos de PHB/PP-g-MA/vermiculita

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, P.J.P. de; Alves, T.S.; Barbosa, R., E-mail: tsaeng3@yahoo.com.br [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Programa de Pos-Graduacao em Ciencia dos Materiais; Andrade, D. de L.A.C.S. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos- Graduacao em Ciencia e Engenharia de Materiais

    2014-07-01

    In this work, we evaluated the process of biodegradation of PHB bionanocomposites/PP-g-MA/clay. Films were prepared with compositions of 5% PP-g-MA and 3% clay (BIO5); and 2.5% PP-g-MA and 3% clay (BIO2.5). The biodegradation test was conducted according to ASTM G 160-03 for a period of 86 days. The evaluation of biodegradation was performed by optical microscopy (MO), loss of mass, FTIR and XRD. The bionanocomposites presented change of coloration and appearance of fissures. As for loss in mass in the system presented loss of BIO2,5 22.5% and 25.9% BIO5, for 86 days of simulated soil exposure. We also observed by FTIR sharp reduction in intensity of the band corresponding to the C = O groups, indicating that the microbial attack promoted cleavage of the ester group links. By XRD, reduction in the intensity of the peaks and enlargements of the same with increasing exposure time, proving the biodegradation behavior of bionanocomposites. (author)

  8. The biodegradable composites of Polyhydroxybutyrate (phb) reinforced by wood flour: properties and degradation

    OpenAIRE

    Caraschi, José Claudio; UEM; Ramos, Uriá Manzolli; UNESP; Leão, ALcides Lopes; UNESP

    2008-01-01

    O objetivo deste trabalho foi preparar e avaliar compósitos poliméricos mais compatíveis com o ambiente, ou seja, a obtenção de materiais que sejam biodegradáveis e que apresentem uma maior velocidade de degradação no ambiente. Os compósitos foram preparados a partir do plástico biodegradável polihidroxibutirato (PHB) com e sem reforço de farinha de madeira, um resíduo agroindustrial, nas proporções de 10% a 40% em massa, pelo processo de extrusão e moldagem por injeção. As amostras foram ava...

  9. Low density polyethylene (LDPE) / poli (3-hydroxy-butyrate) (PHB) blends filled with castor oil cake

    International Nuclear Information System (INIS)

    Rocha, M.C.G.; Oliveira, C.I.R. de; Sanches, M.C.; Coelho, N.N.

    2014-01-01

    Blends of PHB and LDPE were prepared by melt mixing in a Haake internal mixer. Castor oil pressed cake was used as filler for the blends. In order to improve the interfacial adhesion between the filler and the polymers, a mercerization process with 5% NaOH solution was employed. This process was evaluated by several techniques such as: X-Ray diffraction, infrared spectroscopy and scanning electron microscopy (SEM). The mechanical properties were evaluated by traditional tensile stress-strain tests (ASTM D- 638). The obtained results showed that the mercerization process leads to better adhesion properties. The Young Modulus of the blends presented a tendency to increase with the addition of the castor oil cake.(author)

  10. Chain alignment for improved properties - Optimization of PLA and PHB-V by crystallization and reinforcement

    Science.gov (United States)

    Moser, K.; Bergmann, B.; Diemert, J.; Elsner, P.

    2014-05-01

    In this paper two promising ways to improve the material characteristics of PLA and PHB-V are presented by showing their positive effects on mechanical, optical, and thermal properties. The optimization is achieved by increasing the crystallization from the melt of the polymer chains and the other by means of a reinforcement of the matrices by bio-based materials. In the case of crystallization specific nucleating agents and optimized process parameters promote optimized crystallization conditions and lead particularly in toughness to significant improvements. In addition to crystallization the introduction of cellulose-based reinforcing materials is also a good alternative to improve the ductility of a biopolymer matrix considerably. Due to their polar surface structure cellulose fibres are favouring a very good interaction to the also polar biopolymers. In addition, the polar surfaces of both materials results in very homogeneous dispersion within the compound.

  11. Functional Properties of Plasticized Bio-Based Poly(Lactic Acid)_Poly(Hydroxybutyrate) (PLA_PHB) Films for Active Food Packaging

    OpenAIRE

    Burgos, Nuria; Armentano, Ilaria; Fortunati, Elena; Dominici, Franco; Luzi, Francesca; Fiori, Stefano; Cristofaro, Francesco; Visai, Livia; Jiménez, Alfonso; Kenny, José María

    2017-01-01

    Fully bio-based and biodegradable active films based on poly(lactic acid) (PLA) blended with poly(3-hydroxybutyrate) (PHB) and incorporating lactic acid oligomers (OLA) as plasticizers and carvacrol as active agent were extruded and fully characterized in their functional properties for antimicrobial active packaging. PLA_PHB films showed good barrier to water vapor, while the resistance to oxygen diffusion decreased with the addition of OLA and carvacrol. Their overall migration in aqueous f...

  12. Coupled effects of methane monooxygenase and nitrogen source on growth and poly-β-hydroxybutyrate (PHB) production of Methylosinus trichosporium OB3b.

    Science.gov (United States)

    Zhang, Tingting; Zhou, Jiti; Wang, Xiaowei; Zhang, Yu

    2017-02-01

    The coupled effects of nitrogen source and methane monooxygenase (MMO) on the growth and poly-β-hydroxybutyrate (PHB) accumulation capacity of methanotrophs were explored. The ammonia-supplied methanotrophs expressing soluble MMO (sMMO) grew at the highest rate, while N 2 -fixing bacteria expressing particulate MMO (pMMO) grew at the lowest rate. Further study showed that more hydroxylamine and nitrite was formed by ammonia-supplied bacteria containing pMMO, which might cause their slightly lower growth rate. The highest PHB content (51.0%) was obtained under nitrogen-limiting conditions with the inoculation of nitrate-supplied bacteria containing pMMO. Ammonia-supplied bacteria also accumulated a higher content of PHB (45.2%) with the expression of pMMO, while N 2 -fixing bacteria containing pMMO only showed low PHB production capacity (32.1%). The maximal PHB contents of bacteria expressing sMMO were low, with no significant change under different nitrogen source conditions. The low MMO activity, low cell growth rate and low PHB production capacity of methanotrophs continuously cultivated with N 2 with the expression of pMMO were greatly improved in the cyclic NO 3 - N 2 cultivation regime, indicating that long-term deficiency of nitrogen sources was detrimental to the activity of methanotrophs expressing pMMO. Copyright © 2016. Published by Elsevier B.V.

  13. Influence of gamma radiation on thermal properties and water vapor transmission of poly(3-hydroxybutyrate) (PHB) in blends

    Energy Technology Data Exchange (ETDEWEB)

    Forster, Pedro L.; Martins, Natalia A.; Parra, Duclerc F.; Egute, Nayara S.; Lugao, Ademar B., E-mail: dfparra@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Biodegradable polymers are a newly emerging field. A vast number of biodegradable polymers have been synthesized recently and some microorganisms and enzymes capable of degrading them have been identified. Polyesters such as poly(3-hydroxybutyrate) (PHB) or other polyhydroxyalkanoates (PHAs) have attracted commercial and academic interest as new biodegradable materials. In this work, we investigated the effect of gamma radiation on the thermal properties and biodegradation behavior of PHB in blend with poly(ethyleneglycol)(PEG). The samples were irradiated at gamma radiation of 5 and 10 kGy. The thermal behaviour was investigated by utilization of differential scanning calorimetry (DSC) changes in thermal stability, glass transition and melting point were reported. (author)

  14. Influence of gamma radiation on thermal properties and water vapor transmission of poly(3-hydroxybutyrate) (PHB) in blends

    International Nuclear Information System (INIS)

    Forster, Pedro L.; Martins, Natalia A.; Parra, Duclerc F.; Egute, Nayara S.; Lugao, Ademar B.

    2009-01-01

    Biodegradable polymers are a newly emerging field. A vast number of biodegradable polymers have been synthesized recently and some microorganisms and enzymes capable of degrading them have been identified. Polyesters such as poly(3-hydroxybutyrate) (PHB) or other polyhydroxyalkanoates (PHAs) have attracted commercial and academic interest as new biodegradable materials. In this work, we investigated the effect of gamma radiation on the thermal properties and biodegradation behavior of PHB in blend with poly(ethyleneglycol)(PEG). The samples were irradiated at gamma radiation of 5 and 10 kGy. The thermal behaviour was investigated by utilization of differential scanning calorimetry (DSC) changes in thermal stability, glass transition and melting point were reported. (author)

  15. The presence of PHB granules in cytoplasm protects non-halophilic bacterial cells against the harmful impact of hypertonic environments

    Czech Academy of Sciences Publication Activity Database

    Obruča, S.; Sedláček, P.; Mravec, F.; Krzyžánek, Vladislav; Nebesářová, Jana; Samek, Ota; Kučera, D.; Benešová, P.; Hrubanová, Kamila; Milerová, M.; Márová, I.

    2017-01-01

    Roč. 39, OCT (2017), s. 68-80 ISSN 1871-6784 R&D Projects: GA ČR(CZ) GA15-20645S Institutional support: RVO:68081731 ; RVO:60077344 Keywords : Poly(3-hydroxybutyrate) * PHB * cupriavidus necator * hyperosmotic conditions * plasmolysis * stress conditions Subject RIV: BH - Optics, Masers, Lasers; CE - Biochemistry (BC-A) OBOR OECD: Electrical and electronic engineering; Electrical and electronic engineering (BC-A) Impact factor: 3.813, year: 2016

  16. Biodegradable blends of poly (lactic acid) (PLA) / polyhydroxybutrate (PHB) copolymer and its effects on rheological, thermal and mechanical properties

    Science.gov (United States)

    Sood, Nitin K.

    Poly (Lactic acid) is the most important plastic derived from the renewable resources. PLA based products have extensively been used in the medical industry. However, PLA has a few disadvantages such as inherent brittleness and low toughness despite a high modulus. A focus of this experiment was to study the improvement in toughness of PLA and to study the changes in thermal and rheological properties by blending PLA with a PHB copolymer. Where, PLA and PHB copolymer were melt blended using a twin screw Brabender extruder in the ratios of 100/0, 70/30, 50/50, 30/70, 0/100. Further, the blends were injection molded into tensile bar and impact bars for mechanical testing. Rheological properties were studied using a Galaxy capillary rheometer for melt viscosities and temperature dependence indicated a shear-thinning behavior along with power law model and consistency index. Blends were characterized to study the phase model using a differential scanning calorimetric (DSC), showed two separate phases. Mechanical properties were analyzed using a Tensile and Izod impact test indicating decrease in elastic modulus with increase in toughness and elongation as the PHB copolymer content was increased in the blend.

  17. Adhesive strength of bone-implant interfaces and in-vivo degradation of PHB composites for load-bearing applications.

    Science.gov (United States)

    Meischel, M; Eichler, J; Martinelli, E; Karr, U; Weigel, J; Schmöller, G; Tschegg, E K; Fischerauer, S; Weinberg, A M; Stanzl-Tschegg, S E

    2016-01-01

    Aim of this study was to evaluate the response of bone to novel biodegradable polymeric composite implants in the femora of growing rats. Longitudinal observation of bone reaction at the implant site (BV/TV) as well as resorption of the implanted pins were monitored using in vivo micro-focus computed tomography (µCT). After 12, 24 and 36 weeks femora containing the implants were explanted, scanned with high resolution ex vivo µCT, and the surface roughness of the implants was measured to conclude on the ingrowth capability for bone tissue. Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to observe changes on the surface of Polyhydroxybutyrate (PHB) during degradation and cell ingrowth. Four different composites with zirconium dioxide (ZrO2) and Herafill(®) were compared. After 36 weeks in vivo, none of the implants did show significant degradation. The PHB composite with ZrO2 and a high percentage (30%) of Herafill® as well as the Mg-alloy WZ21 showed the highest values of bone accumulation (increased BV/TV) around the implant. The lowest value was measured in PHB with 3% ZrO2 containing no Herafill®. Roughness measurements as well as EDX and SEM imaging could not reveal any changes on the PHB composites׳ surfaces. Biomechanical parameters, such as the adhesion strength between bone and implant were determined by measuring the shear strength as well as push-out energy of the bone-implant interface. The results showed that improvement of these mechanical properties of the studied PHBs P3Z, P3Z10H and P3Z30H is necessary in order to obtain appropriate load-bearing material. The moduli of elasticity, tensile strength and strain properties of the PHB composites are close to that of bone and thus promising. Compared to clinically used PLGA, PGA and PLA materials, their additional benefit is an unchanged local pH value during degradation, which makes them well tolerated by cells and immune system. They might be used

  18. Evaluation of biodegradation of bionanocomposites of PHB/PP-g-MA/vermiculite

    International Nuclear Information System (INIS)

    Mesquita, P.J.P. de; Alves, T.S.; Barbosa, R.; Andrade, D. de L.A.C.S.

    2014-01-01

    In this work, we evaluated the process of biodegradation of PHB bionanocomposites/PP-g-MA/clay. Films were prepared with compositions of 5% PP-g-MA and 3% clay (BIO5); and 2.5% PP-g-MA and 3% clay (BIO2.5). The biodegradation test was conducted according to ASTM G 160-03 for a period of 86 days. The evaluation of biodegradation was performed by optical microscopy (MO), loss of mass, FTIR and XRD. The bionanocomposites presented change of coloration and appearance of fissures. As for loss in mass in the system presented loss of BIO2,5 22.5% and 25.9% BIO5, for 86 days of simulated soil exposure. We also observed by FTIR sharp reduction in intensity of the band corresponding to the C = O groups, indicating that the microbial attack promoted cleavage of the ester group links. By XRD, reduction in the intensity of the peaks and enlargements of the same with increasing exposure time, proving the biodegradation behavior of bionanocomposites. (author)

  19. Surface changes of biopolymers PHB and PLLA induced by Ar+ plasma treatment and wet etching

    Science.gov (United States)

    Slepičková Kasálková, N.; Slepička, P.; Sajdl, P.; Švorčík, V.

    2014-08-01

    Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar+ plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers - polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

  20. Production of poly-{beta}-hydroxybutyrate (PHB) by Methylobacterium organophilum isolated from a methanotrophic consortium in a two-phase partition bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Zuniga, C., E-mail: cristal7n@gmail.com [Universidad Autonoma Metropolitana-Cuajimalpa, Departamento de Procesos y Tecnologia, Artificios 40, Col. Miguel Hidalgo, C.P. 01120, Mexico D.F. (Mexico); Morales, M., E-mail: mmorales@correo.cua.uam.mx [Universidad Autonoma Metropolitana-Cuajimalpa, Departamento de Procesos y Tecnologia, Artificios 40, Col. Miguel Hidalgo, C.P. 01120, Mexico D.F. (Mexico); Le Borgne, S., E-mail: sylvielb@correo.cua.uam.mx [Universidad Autonoma Metropolitana-Cuajimalpa, Departamento de Procesos y Tecnologia, Artificios 40, Col. Miguel Hidalgo, C.P. 01120, Mexico D.F. (Mexico); Revah, S., E-mail: srevah@correo.cua.uam.mx [Universidad Autonoma Metropolitana-Cuajimalpa, Departamento de Procesos y Tecnologia, Artificios 40, Col. Miguel Hidalgo, C.P. 01120, Mexico D.F. (Mexico)

    2011-06-15

    The biodegradation of methane, a greenhouse gas, and the accumulation of poly-{beta}-hydroxybutyrate (PHB) were studied using a methanotrophic consortium and an isolated strain thereof. The specific rates for methane consumption were 100 and 17mg{sub CH{sub 4}}g{sub x}{sup -1} h{sup -1} for the isolate and the consortium, respectively. Also the effect of including 10% (v v{sup -1}) of silicone oil in a two-phase partitioning bioreactor (TPPB) was assayed for the elimination of 1% methane in air stream. TPPB allowed a 33-45% increase of methane elimination under growing conditions. Nitrogen limitation was assayed in bioreactors to promote PHB production. Under this condition, the specific methane degradation rate remained unchanged for the consortium and decreased to 36mg{sub CH{sub 4}}g{sub x}{sup -1} h{sup -1} for the isolated strain. The accumulated PHB in the reactor was 34% and 38% (w w{sup -1}) for the consortium and the isolate, respectively. The highest productivity was obtained in the TPPB and was 1.61mg{sub PHB}g{sub x}{sup -1} h{sup -1}. The CZ-2 isolate was identified as Methylobacterium organophilum, this is the first study that reports this species as being able to grow on methane and accumulate up to 57% (w w{sup -1}) of PHB under nitrogen limitation in microcosm experiments.

  1. Human procollagen type I surface-modified PHB-based non-woven textile scaffolds for cell growth: preparation and short-term biological tests

    International Nuclear Information System (INIS)

    Kawalec, Michał; Sobota, Michał; Kurcok, Piotr; Sitkowska, Anna; Sieroń, Aleksander L; Komar, Patrycja

    2014-01-01

    3D fine porous structures obtained by electrospinning a poly[(R,S)-3-hydroxybutyrate] (aPHB)/ poly[(R)-3-hydroxybutyrate] (PHB) (85/15 w/w) blend were successfully modified with human procollagen type I by simple immersion of the polyester scaffold in an aqueous solution of the protein. Effective modification of the scaffold with human procollagen I was confirmed by an immunodetection test, which revealed the presence of the procollagen type I as an outer layer even on inner structures of the porous matrixes. Biological tests of 3D fabrics made of the PHB blend provide support for the adhesion and proliferation of human fibroblasts, while their modification with procollagen type I increased the biocompatibility of the final scaffolds significantly, as shown by the notable increase in the number of attached cells during the early hours of their incubation. Based on these findings, human procollagen type I surface-modified aPHB/PHB scaffolds should be considered a promising material in regenerative medicine. (paper)

  2. Development and characterization of a PHB-HV-based 3D scaffold for a tissue engineering and cell-therapy combinatorial approach for spinal cord injury regeneration.

    Science.gov (United States)

    Ribeiro-Samy, Silvina; Silva, Nuno A; Correlo, Vitor M; Fraga, Joana S; Pinto, Luísa; Teixeira-Castro, Andreia; Leite-Almeida, Hugo; Almeida, Armando; Gimble, Jeffrey M; Sousa, Nuno; Salgado, António J; Reis, Rui L

    2013-11-01

    Spinal cord injury (SCI) leads to devastating neurological deficits. Several tissue engineering (TE)-based approaches have been investigated for repairing this condition. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) is found to be particularly attractive for TE applications due to its properties, such as biodegradability, biocompatibility, thermoplasticity and piezoelectricity. Hence, this report addresses the development and characterization of PHB-HV-based 3D scaffolds, produced by freeze-drying, aimed to SCI treatment. The obtained scaffolds reveal an anisotropic morphology with a fully interconnected network of pores. In vitro studies demonstrate a lack of cytotoxic effect of PHB-HV scaffolds. Direct contact assays also reveal their ability to support the culture of CNS-derived cells and mesenchymal-like stem cells from different sources. Finally, histocompatibility studies show that PHB-HV scaffolds are well tolerated by the host tissue, and do not negatively impact the left hindlimb locomotor function recovery. Therefore results herein presented suggest that PHB-HV scaffolds may be suitable for SCI treatment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Trapping of intermediates with substrate analog HBOCoA in the polymerizations catalyzed by class III polyhydroxybutyrate (PHB) synthase from Allochromatium vinosum.

    Science.gov (United States)

    Chen, Chao; Cao, Ruikai; Shrestha, Ruben; Ward, Christina; Katz, Benjamin B; Fischer, Christopher J; Tomich, John M; Li, Ping

    2015-05-15

    Polyhydroxybutyrate (PHB) synthases (PhaCs) catalyze the formation of biodegradable PHB polymers that are considered as an ideal alternative to petroleum-based plastics. To provide strong evidence for the preferred mechanistic model involving covalent and noncovalent intermediates, a substrate analog HBOCoA was synthesized chemoenzymatically. Substitution of sulfur in the native substrate HBCoA with an oxygen in HBOCoA enabled detection of (HB)nOCoA (n = 2-6) intermediates when the polymerization was catalyzed by wild-type (wt-)PhaECAv at 5.84 h(-1). This extremely slow rate is due to thermodynamically unfavorable steps that involve the formation of enzyme-bound PHB species (thioesters) from corresponding CoA oxoesters. Synthesized standards (HB)nOCoA (n = 2-3) were found to undergo both reacylation and hydrolysis catalyzed by the synthase. Distribution of the hydrolysis products highlights the importance of the penultimate ester group as previously suggested. Importantly, the reaction between primed synthase [(3)H]-sT-PhaECAv and HBOCoA yielded [(3)H]-sTet-O-CoA at a rate constant faster than 17.4 s(-1), which represents the first example that a substrate analog undergoes PHB chain elongation at a rate close to that of the native substrate (65.0 s(-1)). Therefore, for the first time with a wt-synthase, strong evidence was obtained to support our favored PHB chain elongation model.

  4. Codelivery for Paclitaxel and Bcl-2 Conversion Gene by PHB-PDMAEMA Amphiphilic Cationic Copolymer for Effective Drug Resistant Cancer Therapy.

    Science.gov (United States)

    Wang, Xiaoyuan; Liow, Sing Shy; Wu, Qiaoqiong; Li, Chuang; Owh, Cally; Li, Zibiao; Loh, Xian Jun; Wu, Yun-Long

    2017-11-01

    Antiapoptotic Bcl-2 protein's upregulated expression is a key reason for drug resistance leading to failure of chemotherapy. In this report, a series of biocompatible amphiphilic cationic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) copolymer, comprising hydrophobic PHB block and cationic PDMAEMA block, is designed to codeliver hydrophobic chemotherapeutic paclitaxel and Bcl-2 converting gene Nur77/ΔDBD with enhanced stability, due to the micelle formation by hydrophobic PHB segment. This copolymer shows less toxicity but similar gene transfection efficiency to polyethyenimine (25k). More importantly, this codelivery approach by PHB-PDMAEMA leads to increased drug resistant HepG2/Bcl-2 cancer cell death, by increased expression of Nur77 proteins in the Bcl-2 present intracellular mitochondria. This work signifies for the first time that cationic amphiphilic PHB-b-PDMAEMA copolymers can be utilized for the drug and gene codelivery to drug resistant cancer cells with high expression of antiapoptosis Bcl-2 protein and the positive results are encouraging for the further design of codelivery platforms for combating drug resistant cancer cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Production of poly-β-hydroxybutyrate (PHB) by Methylobacterium organophilum isolated from a methanotrophic consortium in a two-phase partition bioreactor

    International Nuclear Information System (INIS)

    Zuniga, C.; Morales, M.; Le Borgne, S.; Revah, S.

    2011-01-01

    The biodegradation of methane, a greenhouse gas, and the accumulation of poly-β-hydroxybutyrate (PHB) were studied using a methanotrophic consortium and an isolated strain thereof. The specific rates for methane consumption were 100 and 17mg CH 4 g x -1 h -1 for the isolate and the consortium, respectively. Also the effect of including 10% (v v -1 ) of silicone oil in a two-phase partitioning bioreactor (TPPB) was assayed for the elimination of 1% methane in air stream. TPPB allowed a 33-45% increase of methane elimination under growing conditions. Nitrogen limitation was assayed in bioreactors to promote PHB production. Under this condition, the specific methane degradation rate remained unchanged for the consortium and decreased to 36mg CH 4 g x -1 h -1 for the isolated strain. The accumulated PHB in the reactor was 34% and 38% (w w -1 ) for the consortium and the isolate, respectively. The highest productivity was obtained in the TPPB and was 1.61mg PHB g x -1 h -1 . The CZ-2 isolate was identified as Methylobacterium organophilum, this is the first study that reports this species as being able to grow on methane and accumulate up to 57% (w w -1 ) of PHB under nitrogen limitation in microcosm experiments.

  6. Characterization of PHB, zinc oxide and organophilic clay nanocomposites with low field; Caracterizacao de nanocompositos de PHB com oxido de zinco e argila organofilica por RMN de baixo campo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Mariana B.R.; Tavares, Maria Ines B.; Junior, Alberto W.M.; Neto, Roberto P.C. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Nanoparticles of zinc oxide and organophilic clay (Viscogel B8) were added to PHB matrix in some different proportions. The nanocomposites containing both nanoparticles were obtained from solution casting method using chloroform as solvent. The films obtained were analyzed with X-ray diffraction and low field nuclear magnetic resonance to obtain answers about the interactions, dispersion and homogeneity of nanoparticles in the polymer matrix, just like the synergistic effects and the influence of them over some characteristics of the polymer. The synergistic effect achieved from the addition of both nanoparticles was also observed through hydrogen nuclear relaxation time values. (author)

  7. Synthesis of Diblock copolymer poly-3-hydroxybutyrate -block-poly-3-hydroxyhexanoate [PHB-b-PHHx] by a β-oxidation weakened Pseudomonas putida KT2442

    DEFF Research Database (Denmark)

    Tripathi, Lakshmi; Wu, Lin-Ping; Chen, Jinchun

    2012-01-01

    ), thermo- and mechanical analysis. NMR confirmed the existence of diblock copolymers consisting of 58 mol% PHB as the short chain length block with 42 mol% PHHx as the medium chain length block. The block copolymers had two glass transition temperatures (Tg) at 2.7°C and -16.4°C, one melting temperature...... (Tm) at 172.1°C and one cool crystallization temperature (Tc) at 69.1°C as revealed by differential scanning calorimetry (DSC), respectively. This is the first microbial short-chain-length (scl) and medium-chain-length (mcl) PHA block copolymer reported. CONCLUSIONS: It is possible to produce PHA......BACKGROUND: Block polyhydroxyalkanoates (PHA) were reported to be resistant against polymer aging that negatively affects polymer properties. Recently, more and more attempts have been directed to make PHA block copolymers. Diblock copolymers PHB-b-PHHx consisting of poly-3-hydroxybutyrate (PHB...

  8. Ab initio folding of mixed-fold FSD-EY protein using formula-based polarizable hydrogen bond (PHB) charge model

    Science.gov (United States)

    Zhang, Dawei; Lazim, Raudah; Mun Yip, Yew

    2017-09-01

    We conducted an all-atom ab initio folding of FSD-EY, a protein with a ββα configuration using non-polarizable (AMBER) and polarizable force fields (PHB designed by Gao et al.) in implicit solvent. The effect of reducing the polarization effect integrated into the force field by the PHB model, termed the PHB0.7 was also examined in the folding of FSD-EY. This model incorporates into the force field 70% of the original polarization effect to minimize the likelihood of over-stabilizing the backbone hydrogen bonds. Precise folding of the β-sheet of FSD-EY was further achieved by relaxing the REMD structure obtained in explicit water.

  9. Backup Expression of the PhaP2 Phasin Compensates for phaP1 Deletion in Herbaspirillum seropedicae, Maintaining Fitness and PHB Accumulation.

    Science.gov (United States)

    Alves, Luis P S; Teixeira, Cícero S; Tirapelle, Evandro F; Donatti, Lucélia; Tadra-Sfeir, Michelle Z; Steffens, Maria B R; de Souza, Emanuel M; de Oliveira Pedrosa, Fabio; Chubatsu, Leda S; Müller-Santos, Marcelo

    2016-01-01

    Phasins are important proteins controlling poly-3-hydroxybutyrate (PHB) granules formation, their number into the cell and stability. The genome sequencing of the endophytic and diazotrophic bacterium Herbaspirillum seropedicae SmR1 revealed two homologous phasin genes. To verify the role of the phasins on PHB accumulation in the parental strain H. seropedicae SmR1, isogenic strains defective in the expression of phaP1, phaP2 or both genes were obtained by gene deletion and characterized in this work. Despite of the high sequence similarity between PhaP1 and PhaP2, PhaP1 is the major phasin in H. seropedicae, since its deletion reduced PHB accumulation by ≈50% in comparison to the parental and ΔphaP2. Upon deletion of phaP1, the expression of phaP2 was sixfold enhanced in the ΔphaP1 strain. The responsive backup expression of phaP2 partially rescued the ΔphaP1 mutant, maintaining about 50% of the parental PHB level. The double mutant ΔphaP1.2 did not accumulate PHB in any growth stage and showed a severe reduction of growth when glucose was the carbon source, a clear demonstration of negative impact in the fitness. The co-occurrence of phaP1 and phaP2 homologous in bacteria relatives of H. seropedicae, including other endophytes, indicates that the mechanism of phasin compensation by phaP2 expression may be operating in other organisms, showing that PHB metabolism is a key factor to adaptation and efficiency of endophytic bacteria.

  10. Backup expression of the PhaP2 phasin compensates for phaP1 deletion in Herbaspirillum seropedicae, maintaining fitness and PHB accumulation

    Directory of Open Access Journals (Sweden)

    Luis Paulo Silveira Alves

    2016-05-01

    Full Text Available Phasins are important proteins controlling PHB granules formation, their number into the cell and stability. The genome sequencing of the endophytic and diazotrophic bacterium Herbaspirillum seropedicae SmR1 revealed two homologous phasin genes. To verify the role of the phasins on PHB accumulation in the parental strain H. seropedicae SmR1, isogenic strains defective in the expression of phaP1, phaP2 or both genes were obtained by gene deletion and characterized in this work. Despite of the high sequence similarity between PhaP1 and PhaP2, PhaP1 is the major phasin in H. seropedicae, since its deletion reduced PHB accumulation by ≈ 50 % in comparison to the parental and ΔphaP2. Upon deletion of phaP1, the expression of phaP2 was 6-fold enhanced in the ΔphaP1 strain. The responsive backup expression of phaP2 partially rescued the ΔphaP1 mutant, maintaining about 50% of the parental PHB level. The double mutant ΔphaP1.2 did not accumulate PHB in any growth stage and showed a severe reduction of growth when glucose was the carbon source, a clear demonstration of negative impact in the fitness. The co-occurrence of phaP1 and phaP2 homologous in bacteria relatives of H. seropedicae, including other endophytes, indicates that the mechanism of phasin compensation by phaP2 expression may be operating in other organisms, showing that PHB metabolism is a key factor to adaptation and efficiency of endophytic bacteria.

  11. Mobile marketing for mobile games

    OpenAIRE

    Vu, Giang

    2016-01-01

    Highly developed mobile technology and devices enable the rise of mobile game industry and mobile marketing. Hence mobile marketing for mobile game is an essential key for a mobile game success. Even though there are many articles on marketing for mobile games, there is a need of highly understanding mobile marketing strategies, how to launch a mobile campaign for a mobile game. Besides that, it is essential to understand the relationship between mobile advertising and users behaviours. There...

  12. A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

    Science.gov (United States)

    Lee, Chunghee; Clark, Steven E.

    2015-01-01

    The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

  13. GenBank blastx search result: AK061948 [KOME

    Lifescience Database Archive (English)

    Full Text Available droxybutyrate biosynthetic beta-ketothiolase (phbA), and PHB synthase (phbC) genes, complete cds.|BCT BCT 1e-56 +3 ... ...AK061948 001-042-E07 AF267243.2 Azotobacter vinelandii PhbF (phbF), putative phasin protein PhbP (phbP), putative transcription activator PhbR (phb...R), acetoacetyl-CoA reductase (phbB), polyhy

  14. GenBank blastx search result: AK059654 [KOME

    Lifescience Database Archive (English)

    Full Text Available droxybutyrate biosynthetic beta-ketothiolase (phbA), and PHB synthase (phbC) genes, complete cds.|BCT BCT 3e-82 +1 ... ...AK059654 001-031-C10 AF267243.2 Azotobacter vinelandii PhbF (phbF), putative phasin protein PhbP (phb...P), putative transcription activator PhbR (phbR), acetoacetyl-CoA reductase (phbB), polyhy

  15. The Multiple Functions of Common Microbial Carbon Polymers, Glycogen and PHB, during Stress Responses in the Non-Diazotrophic Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Damrow, Ramon; Maldener, Iris; Zilliges, Yvonne

    2016-01-01

    Classical microbial carbon polymers such as glycogen and polyhydroxybutyrate (PHB) have a crucial impact as both a sink and a reserve under macronutrient stress conditions. Most microbial species exclusively synthesize and degrade either glycogen or PHB. A few bacteria such as the phototrophic model organism Synechocystis sp. PCC 6803 surprisingly produce both physico-chemically different polymers under conditions of high C to N ratios. For the first time, the function and interrelation of both carbon polymers in non-diazotrophic cyanobacteria are analyzed in a comparative physiological study of single- and double-knockout mutants (ΔglgC; ΔphaC; ΔglgC/ΔphaC), respectively. Most of the observed phenotypes are explicitly related to the knockout of glycogen synthesis, highlighting the metabolic, energetic, and structural impact of this process whenever cells switch from an active, photosynthetic 'protein status' to a dormant 'glycogen status'. The carbon flux regulation into glycogen granules is apparently crucial for both phycobilisome degradation and thylakoid layer disassembly in the presence of light. In contrast, PHB synthesis is definitely not involved in this primary acclimation response. Moreover, the very weak interrelations between the two carbon-polymer syntheses indicate that the regulation and role of PHB synthesis in Synechocystis sp. PCC 6803 is different from glycogen synthesis.

  16. Association of PHB 1630 C>T and MTHFR 677 C>T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers

    DEFF Research Database (Denmark)

    Jakubowska, A; Rozkrut, D; Antoniou, A

    2012-01-01

    The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either directly or...

  17. Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

    Science.gov (United States)

    Arrieta, Marina Patricia; Castro-López, María del Mar; Rayón, Emilio; Barral-Losada, Luis Fernando; López-Vilariño, José Manuel; López, Juan; González-Rodríguez, María Victoria

    2014-10-15

    Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB. The quantification of catechin released into a fatty food simulant and the antioxidant effectiveness after the release process were demonstrated. The effect of the materials' exposure to a food simulant was also investigated. PHB-added materials maintained their structural and mechanical properties after 10 days in a test medium that represents the worst foreseeable conditions of the intended use. Thus, plasticized PLA-PHB blends with catechin show their potential as biobased active packaging for fatty food.

  18. Synthesis of Nm-PHB (nanomelanin-polyhydroxy butyrate) nanocomposite film and its protective effect against biofilm-forming multi drug resistant Staphylococcus aureus.

    Science.gov (United States)

    Kiran, George Seghal; Jackson, Stephen A; Priyadharsini, Sethu; Dobson, Alan D W; Selvin, Joseph

    2017-08-22

    Melanin is a dark brown ubiquitous photosynthetic pigment which have many varied and ever expanding applications in fabrication of radio-protective materials, food packaging, cosmetics and in medicine. In this study, melanin production in a Pseudomonas sp. which was isolated from the marine sponge Tetyrina citirna was optimized employing one-factor at a time experiments and characterized for chemical nature and stability. Following sonication nucleated nanomelanin (Nm) particles were formed and evaluated for antibacterial and antioxidant properties. Nanocomposite film was fabricated using combinations (% w/v) of polyhydroxy butyrate-nanomelanin (PHB:Nm) blended with 1% glycerol. The Nm was found to be spherical in shape with a diameter of 100-140 nm and showed strong antimicrobial activity against both Gram positive and Gram negative bacteria. The Nm-PHB nanocomposite film was homogeneous, smooth, without any cracks, and flexible. XRD and DSC data indicated that the film was crystalline in nature, and was thermostable up to 281.87 °C. This study represents the first report on the synthesis of Nm and fabrication of Nm-PHB nanocomposite film which show strong protective effect against multidrug resistant Staphyloccoccus aureus. Thus this Nm-PHB nanocomposite film may find utility as packaging material for food products by protecting the food products from oxidation and bacterial contamination.

  19. Flavagline analog FL3 induces cell cycle arrest in urothelial carcinoma cell of the bladder by inhibiting the Akt/PHB interaction to activate the GADD45α pathway.

    Science.gov (United States)

    Yuan, Gangjun; Chen, Xin; Liu, Zhuowei; Wei, Wensu; Shu, Qinghai; Abou-Hamdan, Hussein; Jiang, Lijuan; Li, Xiangdong; Chen, Rixin; Désaubry, Laurent; Zhou, Fangjian; Xie, Dan

    2018-02-07

    Prohibitin 1 (PHB) is a potential target for the treatment of urothelial carcinoma of the bladder (UCB). FL3 is a newly synthesized agent that inhibits cancer cell proliferation by targeting the PHB protein; however, the effect of FL3 in UCB cells remains unexplored. FL3 was identified to be a potent inhibitor of UCB cell viability using CCK-8 (cell counting kit-8) assay. Then a series of in vitro and in vivo experiments were conducted to further demonstrate the inhibitory effect of FL3 on UCB cell proliferation and to determine the underlying mechanisms. FL3 inhibited UCB cell proliferation and growth both in vitro and in vivo. By targeting the PHB protein, FL3 inhibited the interaction of Akt and PHB as well as Akt-mediated PHB phosphorylation, which consequently decreases the localization of PHB in the mitochondria. In addition, FL3 treatment resulted in cell cycle arrest in the G2/M phase, and this inhibitory effect of FL3 could be mimicked by knockdown of PHB. Through the microarray analysis of mRNA expression after FL3 treatment and knockdown of PHB, we found that the mRNA expression of the growth arrest and DNA damage-inducible alpha (GADD45α) gene were significantly upregulated. When knocked down the expression of GADD45α, the inhibitory effect of FL3 on cell cycle was rescued, suggesting that FL3-induced cell cycle inhibition is GADD45α dependent. Our data provide that FL3 inhibits the interaction of Akt and PHB, which in turn activates the GADD45α-dependent cell cycle inhibition in the G2/M phase.

  20. Synthesis of Diblock copolymer poly-3-hydroxybutyrate -block-poly-3-hydroxyhexanoate [PHB-b-PHHx] by a β-oxidation weakened Pseudomonas putida KT2442.

    Science.gov (United States)

    Tripathi, Lakshmi; Wu, Lin-Ping; Chen, Jinchun; Chen, Guo-Qiang

    2012-04-05

    Block polyhydroxyalkanoates (PHA) were reported to be resistant against polymer aging that negatively affects polymer properties. Recently, more and more attempts have been directed to make PHA block copolymers. Diblock copolymers PHB-b-PHHx consisting of poly-3-hydroxybutyrate (PHB) block covalently bonded with poly-3-hydroxyhexanoate (PHHx) block were for the first time produced successfully by a recombinant Pseudomonas putida KT2442 with its β-oxidation cycle deleted to its maximum. The chloroform extracted polymers were characterized by nuclear magnetic resonance (NMR), thermo- and mechanical analysis. NMR confirmed the existence of diblock copolymers consisting of 58 mol% PHB as the short chain length block with 42 mol% PHHx as the medium chain length block. The block copolymers had two glass transition temperatures (Tg) at 2.7°C and -16.4°C, one melting temperature (Tm) at 172.1°C and one cool crystallization temperature (Tc) at 69.1°C as revealed by differential scanning calorimetry (DSC), respectively. This is the first microbial short-chain-length (scl) and medium-chain-length (mcl) PHA block copolymer reported. It is possible to produce PHA block copolymers of various kinds using the recombinant Pseudomonas putida KT2442 with its β-oxidation cycle deleted to its maximum. In comparison to a random copolymer poly-3-hydroxybutyrate-co-3-hydroxyhexanoate (P(HB-co-HHx)) and a blend sample of PHB and PHHx, the PHB-b-PHHx showed improved structural related mechanical properties.

  1. Low density polyethylene (LDPE) / poli (3-hydroxy-butyrate) (PHB) blends filled with castor oil cake; Misturas de polietileno de baixa densidade (PEBD) e poli(3-hidroxibutirato) (PHB) carregados com torta de mamona (TM)

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, M.C.G.; Oliveira, C.I.R. de; Sanches, M.C.; Coelho, N.N., E-mail: mrocha@iprj.uerj.br [Universidade do Estado do Rio de Janeiro (IP/UERJ), Rio de Janeiro, RJ (Brazil). Instituto Politecnico

    2014-07-01

    Blends of PHB and LDPE were prepared by melt mixing in a Haake internal mixer. Castor oil pressed cake was used as filler for the blends. In order to improve the interfacial adhesion between the filler and the polymers, a mercerization process with 5% NaOH solution was employed. This process was evaluated by several techniques such as: X-Ray diffraction, infrared spectroscopy and scanning electron microscopy (SEM). The mechanical properties were evaluated by traditional tensile stress-strain tests (ASTM D- 638). The obtained results showed that the mercerization process leads to better adhesion properties. The Young Modulus of the blends presented a tendency to increase with the addition of the castor oil cake.(author)

  2. Attachment, proliferation and differentiation of BMSCs on gas-jet/electrospun nHAP/PHB fibrous scaffolds

    International Nuclear Information System (INIS)

    Guan Donghua; Chen Zhiqing; Huang Chunpeng; Lin Yinghe

    2008-01-01

    In this study, poly(3-hydroxybutyrate) (PHB)-based scaffolds containing nanosized hydroxyapatite (nHAP) were manufactured by gas-jet/electrospinning. The morphologies of the scaffolds were characterized. The effect of the scaffolds on attachment, proliferation and differentiation of the bone marrow stroma cells (BMSCs) were accessed by using scanning electron microscopy (SEM), methylthiazol tetrazolium (MTT) assay and alkaline phosphatase (ALP) activity. The results show that the gas-jet/electrospun scaffolds possess an extracellular matrix-like topography. In vitro studies describe that the scaffolds have positive effects on attachment, proliferation and differentiation of BMSCs in vitro. It can be concluded that the scaffolds combing the unique structural features generated by gas-jet/electrospinning with functional factors, have the potential to be used in bone tissue engineering

  3. Wireless mobile Internet security

    CERN Document Server

    Rhee, Man Young

    2013-01-01

      The mobile industry for wireless cellular services has grown at a rapid pace over the past decade. Similarly, Internet service technology has also made dramatic growth through the World Wide Web with a wire line infrastructure. Realization for complete wired/wireless mobile Internet technologies will become the future objectives for convergence of these technologies thr

  4. Prohibitin (PHB) inhibits apoptosis in rat granulosa cells (GCs) through the extracellular signal-regulated kinase 1/2 (ERK1/2) and the Bcl family of proteins.

    Science.gov (United States)

    Chowdhury, Indrajit; Thompson, Winston E; Welch, Crystal; Thomas, Kelwyn; Matthews, Roland

    2013-12-01

    Mammalian ovarian follicular development is tightly regulated by crosstalk between cell death and survival signals, which include both endocrine and intra-ovarian regulators. Whether the follicle ultimately ovulates or undergoes atresia is dependent on the expression and actions of factors promoting follicular cell proliferation, differentiation or apoptosis. Prohibitin (PHB) is a highly conserved, ubiquitous protein that is abundantly expressed in granulosa cells (GCs) and associated with GC differentiation and apoptosis. The current study was designed to characterize the regulation of anti-apoptotic and pro-apoptotic factors in undifferentiated rat GCs (gonadotropin independent phase) governed by PHB. Microarray technology was initially employed to identify potential apoptosis-related genes, whose expression levels within GCs were altered by either staurosporine (STS) alone or STS in presence of ectopically over-expressed PHB. Next, immunoblot studies were performed to examine the expression patterns of selective Bcl-2 family members identified by the microarray analysis, which are commonly regulated in the intrinsic-apoptotic pathway. These studies were designed to measure protein levels of Bcl2 family in relation to expression of the acidic isoform (phosphorylated) PHB and the components of MEK-Erk1/2 pathway. These studies indicated that over-expression of PHB in undifferentiated GCs inhibit apoptosis which concomitantly results in an increased level of the anti-apoptotic proteins Bcl2 and Bclxl, reduced release of cytochrome c from mitochondria and inhibition of caspase-3 activity. In contrast, silencing of PHB expression resulted in change of mitochondrial morphology from the regular reticular network to a fragmented form, which enhanced sensitization of these GCs to the induction of apoptosis. Collectively, these studies have provided new insights on the PHB-mediated anti-apoptotic mechanism, which occurs in undifferentiated GCs through a PHB → Mek-Erk1

  5. Improved fed-batch production of high-purity PHB (poly-3 hydroxy butyrate) by Cupriavidus necator (MTCC 1472) from sucrose-based cheap substrates under response surface-optimized conditions.

    Science.gov (United States)

    Dey, Pinaki; Rangarajan, Vivek

    2017-10-01

    Experimental investigations were carried out for Cupriavidus necator (MTCC 1472)-based improved production of poly-3 hydroxy butyrate (PHB) through induced nitrogen limiting fed-batch cultivation strategies. Initially Plackett-Burman design and response surface methodology were implemented to optimize most influencing process parameters. With optimized process parameter values, continuous feeding strategies ware applied in a 5-l fermenter with table sugar concentration of 100 g/l, nitrogen concentration of 0.12 g/l for fed-batch fermentation with varying dilution rates of 0.02 and 0.046 1/h. To get enriched production of PHB, concentration of the sugar was further increased to 150 and 200 g/l in feeding. Maximum concentrations of PHB achieved were 22.35 and 23.07 g/l at those dilution rates when sugar concentration maintains at 200 g/l in feeding. At maximum concentration of PHB (23.07 g/l), productivity of 0.58 g/l h was achieved with maximum PHB accumulation efficiency up to 64% of the dry weight of biomass. High purity of PHB, close to medical grade was achieved after surfactant hypochlorite extraction method, and it was further confirmed by SEM, EDX, and XRD studies.

  6. Research and development project in fiscal 1989 for fundamental technologies for next generation industries. Achievement report on research and development on photoreactive materials (Research on designing and organizing technology for PHB materials); 1989 nendo hikari hanno zairyo no kenkyu kaihatsu seika hokokusho. PHB zairyo no sekkei to soshikika gijutsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-03-01

    With an objective of putting into practical use the wavelength multiplex recording system applied with the PHB phenomenon, research and development has been performed on material systems making high quality hole production possible at high sensitivity and high density. This paper summarizes the achievements in fiscal 1989. In the discussion of PHB materials, measurements were performed on the triple state of zinc, magnesium, copper and iron complexes of tetra-phenyl porphin and the triple state spectra by using the flash decomposition method in order to develop new photo-gate type material systems. Correlation was discovered between the free energy change in the reaction and the PHB reactivity from the result of the experiments, whereas important findings were obtained for designing the photo-gate type PHB material systems. In the discussion of the wavelength multiplex recording, an optical system was designed and fabricated to perform scanning and detection on sample surface by using laser beam squeezed to a diameter of 100 {mu} m. Discussions were given on the wavelength multiplex recording, position multiplex recording, and high-speed recording using this optical system. As a result, position multiplex holes were produced successfully by using the laser beam squeezed to a diameter of 100 {mu} m on four different positions on the sample surface, when the tetra phenylporphin derivative was used. (NEDO)

  7. Proliferation and skeletal myotube formation capability of C2C12 and H9c2 cells on isotropic and anisotropic electrospun nanofibrous PHB scaffolds

    International Nuclear Information System (INIS)

    Ricotti, Leonardo; Genchi, Giada G; Menciassi, Arianna; Polini, Alessandro; Iandolo, Donata; Pisignano, Dario; Ciofani, Gianni; Mattoli, Virgilio; Vazão, Helena; Ferreira, Lino

    2012-01-01

    This study aims at investigating the behavior in terms of the proliferation and skeletal muscle differentiation capability of two myoblastic cell lines, C2C12 and H9c2, on both isotropic and anisotropic electrospun nanofibrous poly(hydroxybutyrate) (PHB) scaffolds, as well as on PHB films and polystyrene controls. After a careful characterization of the matrices in terms of surface morphology, surface roughness and mechanical properties, the proliferation rate and the capability of the two cell lines to form skeletal myotubes were evaluated. Genetic analyses were also performed in order to assess the differentiation level of the cells on the different substrates. We demonstrated that the aligned nanofibrous mesh decreases the proliferation activity and provides a higher differentiative stimulus. We also clarified how the nanofibrous substrate influences myotube formation, and quantified a series of myotube-related parameters for both C2C12 and H9c2 cells. (paper)

  8. Overcoming STC2 mediated drug resistance through drug and gene co-delivery by PHB-PDMAEMA cationic polyester in liver cancer cells.

    Science.gov (United States)

    Cheng, Hongwei; Wu, Zhixian; Wu, Caisheng; Wang, Xiaoyuan; Liow, Sing Shy; Li, Zibiao; Wu, Yun-Long

    2018-02-01

    Stanniocalcin 2 (STC2) overexpression in hepatocellular carcinoma (HCC) could lead to poor prognosis, which might be due to its induced P-glycoprotein and Bcl-2 protein expression level increase. P-glycoprotein or membrane pump induced drug efflux and altered prosurvival Bcl-2 expression are key mechanisms for drug resistance leading to failure of chemotherapy in HCC. However, current strategy to overcome both P-glycoprotein and Bcl-2 protein induced drug resistance was rarely reported. In this work, we utilized an amphiphilic poly[(R)-3-hydroxybutyrate] (PHB)-b-poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) cationic polyester to encapsulate chemotherapeutic paclitaxel (PTX) in hydrophobic PHB domain and Bcl-2 convertor Nur77/ΔDBD gene (Nur77 without DNA binding domain for mitochondria localization) by formation of polyplex due to cationic PDMAEMA segment, to effectively inhibit the drug resistant HepG2/STC2 and SMCC7721/STC2 liver cancer cell growth. Thanks to the cationic nanoparticle complex formation ability and high transfection efficiency to express Bcl-2 conversion proteins, PHB-PDMAEMA/PTX@polyplex could partially impair P-glycoprotein induced PTX efflux and activate the apoptotic function of previous prosurvival Bcl-2 protein. This is the pioneer report of cationic amphiphilic polyester PHB-PDMAEMA to codeliver anticancer drug and therapeutic plasmid to overcome both pump and non-pump mediated chemotherapeutic resistance in liver cancer cells, which might be inspiring for the application of polyester in personalized cancer therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Viability of HEK 293 cells on poly-β-hydroxybutyrate (PHB) biosynthesized from a mutant Azotobacter vinelandii strain. Cast film and electrospun scaffolds.

    Science.gov (United States)

    Romo-Uribe, Angel; Meneses-Acosta, Angelica; Domínguez-Díaz, Maraolina

    2017-12-01

    Sterilization, cytotoxicity and cell viability are essential properties defining a material for medical applications and these characteristics were investigated for poly(β-hydroxybutyrate) (PHB) of 230kDa obtained by bacterial synthesis from a mutant strain of Azotobacter vinelandii. Cell viability was investigated for two types of PHB scaffolds, solution cast films and non-woven electrospun fibrous membranes, and the efficiency was compared against a culture dish. The biosynthesized PHB was sterilized by ultraviolet radiation and autoclave, it was found that the thermal properties and intrinsic viscosity remained unchanged indicating that the sterilization methods did not degrade the polymer. Sterilized scaffolds were then seeded with human embryonic kidney 293 (HEK 293) cells to evaluate the cytotoxic response. The cell viability of these cells was evaluated for up to six days, and the results showed that the cell morphology was normal, with no cytotoxic effects. The films and electrospun membranes exhibited over 95% cell viability whereas the viability in culture dishes reached only ca. 90%. The electrospun membrane, however, exhibited significantly higher cell density than the cast film suggesting that the fibrous morphology enables better nutrients transfer. The results indicate that the biosynthesized PHB stands UV and autoclave sterilization methods, it is biocompatible and non-toxic for cell growth of human cell lines. Furthermore, cell culture for up to 18 days showed that 62% and 90% of mass was lost for the film and fibrous electrospun scaffold, respectively. This is a favorable outcome for use in tissue engineering where material degradation, as tissue regenerates, is desirable. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The efficacy of Poly-β-Hydroxy Butyrate (PHB)/biosurfactant derived from Staphylococcus hominis against White Spot Syndrome Virus (WSSV) in Penaeus monodon.

    Science.gov (United States)

    Monica, M; Priyanka, T; Akshaya, Murugesan; Rajeswari, V; Sivakumar, Lingappa; Somasundaram, S T; Shenbhagarathai, R

    2017-12-01

    White Spot Syndrome Virus (WSSV) is one of the most important causative agents of Penaeid shrimps diseases that incur heavy losses to the shrimp aquaculture. It has severe impact on the sustainability and the production of Penaeus monodon. Hence, the present study focussed on the investigation of Poly-β-hydroxybutyrate/biosurfactant as immunostimulants against WSSV infected shrimps. Infection of WSSV was periodically checked in all the experimental shrimps using PCR diagnostic kit. After ensuring all shrimps were free of viral infection, experiments were carried out to analyze the nonspecific immune responses (prophenol oxidase, nitro blue tetrazolium reduction assay and total haemocyte count) both in control and experimental group. Further, gills and muscles of Penaeus monodon were subjected to proteome analysis after treated it with PHB/biosurfactant independently in the concentration of 2% and 5% each. Increase in the level of haemocytes was observed in both PHB (26 ± 2 × 10⁴ cells)/biosurfactant (28 ± 2 × 10 4  cells) treated shrimps, when compared with control (17 ± 2 × 10⁴ cells). proPhenolOxidase (proPO) activity was also enhanced in treated groups compared to WSSV infected shrimps. Less production of superoxide anion was observed in control and treated groups. Differences in the protein expression was analyzed in muscle tissue of control, WSSV infected and PHB/biosurfactant treated shrimps. Our finding suggested that partial substitution of feed with 2% PHB and biosurfactant showed increased rate on the survival of WSSV infected P. monodon which might be due to either the over expression/down regulation of proteins that play a vital role in enhancing the immune system/the progression of the disease respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Poly-3-hydroxybutyrate (PHB) production from alkylphenols, mono and poly-aromatic hydrocarbons using Bacillus sp. CYR1: A new strategy for wealth from waste.

    Science.gov (United States)

    Venkateswar Reddy, M; Mawatari, Yasuteru; Yajima, Yuka; Seki, Chigusa; Hoshino, Tamotsu; Chang, Young-Cheol

    2015-09-01

    In the present study five different types of alkylphenols, each of the two different types of mono and poly-aromatic hydrocarbons were selected for degradation, and conversion into poly-3-hydroxybutyrate (PHB) using the Bacillus sp. CYR1. Strain CYR1 showed growth with various toxic organic compounds. Degradation pattern of all the organic compounds at 100 mg/l concentration with or without addition of tween-80 were analyzed using high pressure liquid chromatography (HPLC). Strain CYR1 showed good removal of compounds in the presence of tween-80 within 3 days, but it took 6 days without addition of tween-80. Strain CYR1 showed highest PHB production with phenol (51 ± 5%), naphthalene (42 ± 4%), 4-chlorophenol (32 ± 3%) and 4-nonylphenol (29 ± 3%). The functional groups, structure, and thermal properties of the produced PHB were analyzed. These results denoted that the strain Bacillus sp. CYR1 can be used for conversion of different toxic compounds persistent in wastewaters into useable biological polyesters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Environmentally Friendly Compatibilizers from Soybean Oil for Ternary Blends of Poly(lactic acid-PLA, Poly(ε-caprolactone-PCL and Poly(3-hydroxybutyrate-PHB

    Directory of Open Access Journals (Sweden)

    María Jesús Garcia-Campo

    2017-11-01

    Full Text Available Ternary blends of poly(lactic acid (PLA, poly(3-hydroxybutyrate (PHB and poly(ε-caprolactone (PCL with a constant weight percentage of 60%, 10% and 30% respectively were compatibilized with soybean oil derivatives epoxidized soybean oil (ESO, maleinized soybean oil (MSO and acrylated epoxidized soybean oil (AESO. The potential compatibilization effects of the soybean oil-derivatives was characterized in terms of mechanical, thermal and thermomechanical properties. The effects on morphology were studied by field emission scanning electron microscopy (FESEM. All three soybean oil-based compatibilizers led to a noticeable increase in toughness with a remarkable improvement in elongation at break. On the other hand, both the tensile modulus and strength decreased, but in a lower extent to a typical plasticization effect. Although phase separation occurred, all three soybean oil derivatives led somewhat to compatibilization through reaction between terminal hydroxyl groups in all three biopolyesters (PLA, PHB and PCL and the readily reactive groups in the soybean oil derivatives, that is, epoxy, maleic anhydride and acrylic/epoxy functionalities. In particular, the addition of 5 parts per hundred parts of the blend (phr of ESO gave the maximum elongation at break while the same amount of MSO and AESO gave the maximum toughness, measured through Charpy’s impact tests. In general, the herein-developed materials widen the potential of ternary PLA formulations by a cost effective blending method with PHB and PCL and compatibilization with vegetable oil-based additives.

  13. Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity

    Directory of Open Access Journals (Sweden)

    Boguslawa Żywicka

    2017-10-01

    Full Text Available Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide, (PLGA, and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate (PLGA/PHB. The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

  14. Environmentally Friendly Compatibilizers from Soybean Oil for Ternary Blends of Poly(lactic acid)-PLA, Poly(ε-caprolactone)-PCL and Poly(3-hydroxybutyrate)-PHB.

    Science.gov (United States)

    Garcia-Campo, María Jesús; Quiles-Carrillo, Luis; Masia, Jaime; Reig-Pérez, Miguel Jorge; Montanes, Nestor; Balart, Rafael

    2017-11-22

    Ternary blends of poly(lactic acid) (PLA), poly(3-hydroxybutyrate) (PHB) and poly(ε-caprolactone) (PCL) with a constant weight percentage of 60%, 10% and 30% respectively were compatibilized with soybean oil derivatives epoxidized soybean oil (ESO), maleinized soybean oil (MSO) and acrylated epoxidized soybean oil (AESO). The potential compatibilization effects of the soybean oil-derivatives was characterized in terms of mechanical, thermal and thermomechanical properties. The effects on morphology were studied by field emission scanning electron microscopy (FESEM). All three soybean oil-based compatibilizers led to a noticeable increase in toughness with a remarkable improvement in elongation at break. On the other hand, both the tensile modulus and strength decreased, but in a lower extent to a typical plasticization effect. Although phase separation occurred, all three soybean oil derivatives led somewhat to compatibilization through reaction between terminal hydroxyl groups in all three biopolyesters (PLA, PHB and PCL) and the readily reactive groups in the soybean oil derivatives, that is, epoxy, maleic anhydride and acrylic/epoxy functionalities. In particular, the addition of 5 parts per hundred parts of the blend (phr) of ESO gave the maximum elongation at break while the same amount of MSO and AESO gave the maximum toughness, measured through Charpy's impact tests. In general, the herein-developed materials widen the potential of ternary PLA formulations by a cost effective blending method with PHB and PCL and compatibilization with vegetable oil-based additives.

  15. Mobile Learning Using Mobile Phones

    Science.gov (United States)

    Vicente, Paula

    2013-01-01

    The participation in mobile learning programs is conditioned by having/using mobile communication technology. Those who do not have or use such technology cannot participate in mobile learning programs. This study evaluates who are the most likely participants of mobile learning programs by examining the demographic profile and mobile phone usage…

  16. Complete sequencing of IncI1 sequence type 2 plasmid pJIE512b indicates mobilization of blaCMY-2 from an IncA/C plasmid.

    Science.gov (United States)

    Tagg, Kaitlin A; Iredell, Jonathan R; Partridge, Sally R

    2014-08-01

    Sequencing of pJIE512b, a 92.3-kb IncI1 sequence type 2 (ST2) plasmid carrying bla(CMY-2), revealed a bla(CMY-2) context that appeared to have been mobilized from an IncA/C plasmid by the insertion sequence IS1294. A comparison with published plasmids suggests that bla(CMY-2) has been mobilized from IncA/C to IncI1 plasmids more than once by IS1294-like elements. Alignment of pJIE512b with the only other available IncI1 ST2 plasmid revealed differences across the backbones, indicating variability within this sequence type. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. Staging Mobilities / Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2015-01-01

    , and systems 'hosting' these multiple and complex mobilities are designed and how they are staging these in terms of their physical layout. By analysing specific cases of ‘mobilities design’ related to the four modes of moving; Walk, Bike, Train, and Car, the book uncover important and until now neglected...... is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments, the project...

  18. Mobility management in mobile IP

    Science.gov (United States)

    Medidi, Sirisha; Golshani, Forouzan

    2002-07-01

    There is an emerging interest in integrating mobile wireless communication with the Internet based on the Ipv6 technology. Many issues introduced by the mobility of users arise when such an integration is attempted. This paper addresses the problem of mobility management, i.e., that of tracking the current IP addresses of mobile terminals and sustaining active IP connections as mobiles move. The paper presents some architectural and mobility management options for integrating wireless access to the Internet. We then present performance results for Mobile IPv4, route optimization and Mobile IPv6.

  19. Surface changes of biopolymers PHB and PLLA induced by Ar{sup +} plasma treatment and wet etching

    Energy Technology Data Exchange (ETDEWEB)

    Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2014-08-01

    Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar{sup +} plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers – polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

  20. Avaliação da Biodegradação de Poli-beta-(Hidroxibutirato, Poli-beta-(Hidroxibutirato-co-valerato e Poli-épsilon-(caprolactona em Solo Compostado Evaluation of PHB, PHB-V and PCL biodegradation in composted soil

    Directory of Open Access Journals (Sweden)

    Derval S. Rosa

    2002-10-01

    Full Text Available Na sociedade contemporânea, uma solução ou um equacionamento minimamente satisfatório para os graves problemas ambientais decorrentes da larga utilização de polímeros tem se constituído num dos grandes desafios colocados para a comunidade científica. Na busca por soluções desejáveis, e como alternativa aos polímeros convencionais, os polímeros biodegradáveis têm sido alçados a uma posição de destaque. Dessa maneira, as pesquisas em torno desses compostos também vão adquirindo fundamental importância. Nesse trabalho, apresentamos os resultados da avaliação da biodegradação do poli-beta-(hidroxibutirato (PHB, o poli-beta-(hidroxibutirato-co-valerato (PHB-V e o poli-(épsilon-caprolactona (PCL em solo compostado, utilizando a técnica de biodegradação aeróbia conhecida como Teste de Sturm. As análises térmicas destes polímeros foram realizadas usando calorimetria exploratória diferencial (DSC e a temperatura de fusão e a cristalinidade, para cada polímero, foram determinadas. Os resultados mostraram que o PHB degradou mais rápido que os dois outros polímeros, provavelmente por causa da sua estrutura química que pode ser atacada mais facilmente pelos microorganismos.In contemporary society, a solution or a minimally satisfying approach to the serious environmental problems stemming from the widespread use of polymers has been one of the great challenges the scientific community has had to cope with. The studies around these compounds, including their biodegradability, have acquired fundamental importance. In this work, we present the results from an evaluation of the biodegradation of poly-beta-(hydroxybutyrate (PHB, poly-beta-(hydroxybutyrate-co-valerate (PHB-V and poly-(epsilon-caprolactone (PCL, with products obtained from composting of municipal solid wastes, using the technique of aerobic biodegradation characterization known as Sturm Test. The thermal analysis of these polymers was done using differential

  1. Citocompatibilidade de blendas de poli(p-dioxanona/ poli(hidroxi butirato (PPD/PHB para aplicações em engenharia de tecido cartilaginoso Cytocompatibility of poly(p-dioxanone/ poly(hydroxybutic (PPD/PHB blends to cartilage tissue engineering

    Directory of Open Access Journals (Sweden)

    Andrea R. Esposito

    2010-01-01

    Full Text Available Buscando estratégias que repercutam na melhoria da interação entre materiais poliméricos biorreabsorvíveis e o crescimento celular, o presente estudo in vitro teve como objetivo estudar a influência de blendas de PPD/PHB na adesão celular e crescimento de fibrocondrócitos obtidos a partir de cultura primária. As blendas de PPD/PHB foram preparadas pelo método de evaporação de solvente nas composições 100/0, 60/40 e 50/50 e caracterizadas por microscopia eletrônica de varredura (MEV. Observações ultra-estruturais mostraram alterações na morfologia celular, sugerindo que os fibrocondrócitos podem responder a alterações no substrato alterando seu perfil fenotípico. As análises com MTT demonstraram que as blendas não apresentaram citotoxicidade e permitiram a adesão e proliferação dos fibrocondrócitos sobre os substratos em todas as suas composições. O ensaio colorimétrico com Sirius Red evidenciou a capacidade de manutenção da síntese de matriz extracelular colágena sobre as amostras, concluindo-se que as blendas de PPD/PHB podem ser indicadas para o cultivo celular.In order of seek strategies to improve the interaction between bioreabsorbable polymer materials and cellular growth, this work aimed at evaluating in vitro the influence of PPD/PHB blends on cell adhesion and fibrochondrocytes growth. Fibrochondrocytes cells were obtained by primary extraction from enzymatic digestion methods. The PPD/PHB blends were prepared by casting with 100/0, 60/40 and 50/50 compositions, and were characterized by scanning electron microscopy (SEM. After 6, 48, 120 and 168 hours in culture, ultrastructural observations showed changes in cell morphology, suggesting that the fibrochondrocytes can respond to substrate modifications, changing their phenotypic profile. The MTT analyses showed that the blends did not present cytotoxicity and allowed fibrochondrocytes adhesion and proliferation on the membranes in all compositions

  2. Mobile Election

    OpenAIRE

    Long, Elena; Lovitskii, Vladimir; Thrasher, Michael; Traynor, David

    2009-01-01

    Mobile phones have the potential of fostering political mobilisation. There is a significant political power in mobile technology. Like the Internet, mobile phones facilitate communication and rapid access to information. Compared to the Internet, however, mobile phone diffusion has reached a larger proportion of the population in most countries, and thus the impact of this new medium is conceivably greater. There are now more mobile phones in the UK than there are people (ave...

  3. Mobile Advertising

    OpenAIRE

    Alamuri, Lavanya

    2009-01-01

    The aim of this project was to get an understanding of how companies adopt mobile as an advertising medium. The literature review aided in framing a draft of the factors that affect mobile advertising adoption and possible forms of mobile advertising. Considering the scope of the thesis work, branding strategy, service costs, personalization and privacy and platform were considered to be the factors that could affect the mobile advertising adoption. A few possible forms on mobile device we...

  4. Mobile agents basic concepts, mobility models, and the tracy toolkit

    CERN Document Server

    Braun, Peter

    2005-01-01

    Mobile agents are software nomads that act as your personal representative, working autonomously through networks. They are able to visit network nodes directly using available computing power and are not limited by platform. This emerging field is now poised to become a cornerstone for new Web-based ubiquitous computing environments. Mobile Agents provides a practical introduction to mobile agent technology and surveys the state of the art in mobile agent research. Students and researchers can use the book as an introduction to the concepts and possibilities of this field and as an overview of ongoing research. Developers can use it to identify the capabilities of the technology to decide if mobile agents are the right solution for them. Practioners can also gain hands-on experience in programming mobile agents through exploration of the source code for a complete mobile agent environment available through the companion website.*Summarizes the state of the art in mobile agent research*Identifies the benefits...

  5. Mobilities Design

    DEFF Research Database (Denmark)

    Lanng, Ditte Bendix; Wind, Simon; Jensen, Ole B.

    2017-01-01

    Mobilities comprise a large part of our world and everyday lives, and the mobilities spaces in which we travel are ubiquitous. Yet, ordinary mobilities spaces – such as parking lots, pedestrian tunnels, and road lay-bys – tend to be criticized as typologies that lack consideration for the people...... who use them and for their wider social, aesthetic, cultural, and ecological agency in the city. This is clearly not an unambiguous characterization. But from it follows an urgency to re-examine unheeded mobilities spaces and extend demands of their agency beyond standards of technical efficiency....... This article draws on the recent “mobilities turn” in social science to support such re-examination of mobilities spaces. In social-scientific mobilities research, mobilities are considered the departure point for understanding the socio-material world in which we live. Mobilities are regarded as far more than...

  6. Mobile Workforce, Mobile Technology, Mobile Threats

    International Nuclear Information System (INIS)

    Garcia, J.

    2015-01-01

    Mobile technologies' introduction into the world of safeguards business processes such as inspection creates tremendous opportunity for novel approaches and could result in a number of improvements to such processes. Mobile applications are certainly the wave of the future. The success of the application ecosystems has shown that users want full fidelity, highly-usable, simple purpose applications with simple installation, quick responses and, of course, access to network resources at all times. But the counterpart to opportunity is risk, and the widespread adoption of mobile technologies requires a deep understanding of the threats and vulnerabilities inherent in mobile technologies. Modern mobile devices can be characterized as small computers. As such, the threats against computing infrastructure apply to mobile devices. Meanwhile, the attributes of mobile technology that make it such an obvious benefit over traditional computing platforms all have elements of risk: pervasive, always-on networking; diverse ecosystems; lack of centralized control; constantly shifting technological foundations; intense competition among competitors in the marketplace; the scale of the installation base (from millions to billions); and many more. This paper will explore the diverse and massive environment of mobile, the number of attackers and vast opportunities for compromise. The paper will explain how mobile devices prove valuable targets to both advanced and persistent attackers as well as less-skilled casual hackers. Organized crime, national intelligence agencies, corporate espionage are all part of the landscape. (author)

  7. Functionalized PHB granules provide the basis for the efficient side-chain cleavage of cholesterol and analogs in recombinant Bacillus megaterium.

    Science.gov (United States)

    Gerber, Adrian; Kleser, Michael; Biedendieck, Rebekka; Bernhardt, Rita; Hannemann, Frank

    2015-07-29

    Cholesterol, the precursor of all steroid hormones, is the most abundant steroid in vertebrates and exhibits highly hydrophobic properties, rendering it a difficult substrate for aqueous microbial biotransformations. In the present study, we developed a Bacillus megaterium based whole-cell system that allows the side-chain cleavage of this sterol and investigated the underlying physiological basis of the biocatalysis. CYP11A1, the side-chain cleaving cytochrome P450, was recombinantly expressed in the Gram-positive soil bacterium B. megaterium combined with the required electron transfer proteins. By applying a mixture of 2-hydroxypropyl-β-cyclodextrin and Quillaja saponin as solubilizing agents, the zoosterols cholesterol and 7-dehydrocholesterol, as well as the phytosterol β-sitosterol could be efficiently converted to pregnenolone or 7-dehydropregnenolone. Fluorescence-microscopic analysis revealed that cholesterol accumulates in the carbon and energy storage-serving poly(3-hydroxybutyrate) (PHB) bodies and that the membrane proteins CYP11A1 and its redox partner adrenodoxin reductase (AdR) are likewise localized to their surrounding phospholipid/protein monolayer. The capacity to store cholesterol was absent in a mutant strain devoid of the PHB-producing polymerase subunit PhaC, resulting in a drastically decreased cholesterol conversion rate, while no effect on the expression of the recombinant proteins could be observed. We established a whole-cell system based on B. megaterium, which enables the conversion of the steroid hormone precursor cholesterol to pregnenolone in substantial quantities. We demonstrate that the microorganism's PHB granules, aggregates of bioplastic coated with a protein/phospholipid monolayer, are crucial for the high conversion rate by serving as substrate storage. This microbial system opens the way for an industrial conversion of the abundantly available cholesterol to any type of steroid hormones, which represent one of the

  8. PEMANFAATAN RELAI TUNDA WAKTU DAN KONTAKTOR PADA PANEL HUBUNG BAGI (PHB UNTUK PRAKTEK PENGHASUTAN STARTING MOTOR STAR DELTA

    Directory of Open Access Journals (Sweden)

    I Gede Siden Sudaryana

    2015-07-01

    Full Text Available Tujuan dari pemanfaatan relai tunda watu selanjutnya disebut TDR (Time Delay Relay dan kontaktor adalah sebagai salah satu modul pembelajaran mahasiswa di Laboratorium Teknik Tenaga Listrik sebagai pendukung mata kuliah Panel Hubung Bagi (PHB. Selama ini pemahaman yang dimiliki mahasiswa mengenai sistem kerja TDR dan kontaktor belum maksimal, yang menyebabkan mahasiswa belum siap diterjunkan ke lapangan dunia industri, dikarenakan kurangnya modul praktek di Laboratorium. Berdasarkan hal tersebut perlu dirancang dan dibuat suatu alat berupa Modul Praktek sebagai media pembelajaran tentang pengoperasian TDR dan kontaktor. Modul Praktek ini disusun dalam bentuk modul pembelajaran yang berisi uraian materi, tentang operasi sistem kunci rangakaian Otomatisasi Lampu Taman, sistem Direct On Line (DOL, sistem Interlock hidup secara bergantian, Interlock hidup berurutan, Putar balik Motor, penghasutan/starting motor Star-Delta. Pada kesempatan ini akan dibahas tentang pemanfaatan TDR dan Kontaktor dimana komponen-komponen tersebut adalah sebagai rangkaian kontrol yang dipergunakan pada pengendali sistem penghasutan starting motor star-delta. Sistem hidup berurutan saat push button ON ditekan yaitu rangkaian kontaktor K1 dan K2 yang akan menghubungkan rangkaian motor star, sedang rangkaian kontaktor K1 dan K3 yang akan menghubungkan rangkaian motor menjadi delta. Operasi kontaktor K2 dan K3 bekerja secara berurutan/bergantian. Jika push button OFF ditekan maka semua kontaktor akan terputus. Sistem hidup bergantian menggunakan sistem Interlock dimana K2 dan K3 tidak boleh hidup bersamaan, dimana K3 akan mengalami penundaan waktu selama 5 detik setelah K2 bekerja, sedangkan kontaktor K1 tetap bekerja dengan sistem Direct On Line (DOL. Penundaan waktu bekerjanya kontaktor K3 setelah K2 terputus secara automatis, dengan menggunakan komponen TDR (Time Delay Relay. Hasilnya, dengan pemanfaatan TDR pada rangkaian star-delta mahasiswa lebih mengerti cara kerja

  9. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely that of ‘m......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the background of the ‘mobilities turn’ (e.g. Cresswell 2006, Urry 2007) this book articulates a new and emerging research field, namely...... that of ‘mobilities design’. The book revolves around the following research question: How are design decisions and interventions staging mobilities? It builds upon the Staging Mobilities model (Jensen 2013) in an explorative inquiry into the problems and potentials of the design of mobilities. The exchange value...

  10. Mobile economy

    OpenAIRE

    Turowski, Klaus

    2004-01-01

    Mobile economy : Transaktionen, Prozesse, Anwendungen und Dienste ; 4. Workshop Mobile Commerce, 02.-03. Februar 2004, Univ. Augsburg / K. Turowski ... (Hrsg.). - Bonn : Ges. für Informatik, 2004. - 189 S. : Ill., graph. Darst. - (GI-Edition : Proceedings ; 42)

  11. Mobile marketing

    OpenAIRE

    Gause, Matěj

    2012-01-01

    The goal of bachelor's thesis on the theme "Mobile marketing" is to outline its development and why is this new phenomen so important for all modern companies around the world. The work is not about simple description of mobile marketing media but it vividly informs about the latest trends and news from the world of mobile apps and games. It presents the most successful mobile apps which registered more than billion downloads and from their unique characteristics it unveils great potential of...

  12. Mobile marketing

    OpenAIRE

    KLEČKOVÁ, Zuzana

    2013-01-01

    The main aim of this thesis was to provide a comprehensive overview of the mobile marketing and analyze selected campaigns of Czech mobile marketing in comparison to world successful campaigns. The research contained studying of available literature about the theme to gain general knowledge about the issue. The theoretical part of the thesis contains predominantly various definitions of mobile marketing and its tools, advantages of these tools and some information about Mobile Marketing Assoc...

  13. Síntese e Caracterização de Nanocompósitos de Poli(3-hidroxibutirato) - PHB/ZnO e Poli(tereftalato de etileno) - PET/ZnO

    OpenAIRE

    LIMA JÚNIOR, Reginaldo Gomes de

    2015-01-01

    Neste trabalho o óxido de zinco nanoestruturado (ZnOnano) foi incorporado em duas matrizes poliméricas: o poli(hidroxibutirato), e o poli(tereftalato de etileno), com o objetivo de avaliar o efeito desta adição nas propriedades físicas, químicas, bem como a atividade antimicrobiana para o nanocompósito PHB/ZnOnano, tendo como referência a bactéria Escherichia coli. Filmes de PHB/ZnOnano foram produzidos por casting, com parâmetros de síntese obtidos a partir de um planejamento experimental 24...

  14. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    and lived as people are “staging themselves” (from below). Staging mobilities is a dynamic process between “being staged” (for example, being stopped at traffic lights) and the “mobile staging” of interacting individuals (negotiating a passage on the pavement). Staging Mobilities is about the fact...

  15. Subversive Mobilities

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2013-01-01

    The article approaches mobility through a cultural history of urban conflict. Using a case of “The Copenhagen Trouble,“ a series of riots in the Danish capital around 1900, a space of subversive mobilities is delineated. These turn-of-the-century riots points to a new pattern of mobile gathering...

  16. Completely continuous and weakly completely continuous abstract ...

    Indian Academy of Sciences (India)

    An algebra A is called right completely continuous (right weakly completely continuous) ... Moreover, some applications of these results in group algebras are .... A linear subspace S(G) of L1(G) is said to be a Segal algebra, if it satisfies the.

  17. Mobile Probes in Mobile Learning

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Blomhøj, Ulla; Duvaa, Uffe

    In this paper experiences from using mobile probes in educational design of a mobile learning application is presented. The probing process stems from the cultural probe method, and was influenced by qualitative interview and inquiry approaches. In the project, the mobile phone was not only acting...... as an agent for acquiring empirical data (as the situation in hitherto mobile probe settings) but was also the technological medium for which data should say something about (mobile learning). Consequently, not only the content of the data but also the ways in which data was delivered and handled, provided...... a valuable dimension for investigating mobile use. The data was collected at the same time as design activities took place and the collective data was analysed based on user experience goals and cognitive processes from interaction design and mobile learning. The mobile probe increased the knowledge base...

  18. Mobile Semiotics

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2013-01-01

    This chapter aims to understand the mobile condition of contemporary life with a particular view to the signifying dimension of the environment and its ‘readability’. The chapter explores the potentials of semiotics and its relationship to the new mobilities literature. What takes place...... is a ‘mobile sense making’ where signs and materially situated meanings connect to the moving human body and thus create particular challenges and complexities of making sense of the world. The chapter includes notions of mobility systems and socio-technical networks in order to show how a ‘semiotic layer’ may...... work to afford or restrict mobile practices....

  19. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2014-01-01

    Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation and the mob......Users are already mobile, but the question is to which extent knowledge-based dictionary apps are designed for the mobile user situation. The objective of this article is to analyse the characteristics of the mobile user situation and to look further into the stationary user situation...... and the mobile user situation. The analysis is based on an empirical survey involving ten medical doctors and a monolingual app designed to support cognitive lexicographic functions, cf. (Tarp 2006:61-64). In test A the doctors looked up five medical terms while sitting down at a desk and in test B the doctors...

  20. Mobility Divides

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    Contemporary mobilities are cultural and social manifestations, and the mobile practices in the everyday life of billions of humans are re-configuring senses of place, self, other and relationships to the built environment. The way ‘mobile situations’ are staged in designed and built environments......’ in the everyday life and cast light on how design and ‘materialities of mobilites’ are creating differential mobilities across societies, social networks, and communities of practices.......Contemporary mobilities are cultural and social manifestations, and the mobile practices in the everyday life of billions of humans are re-configuring senses of place, self, other and relationships to the built environment. The way ‘mobile situations’ are staged in designed and built environments...

  1. Mobile Semiotics - signs and mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    a potential for mobilities studies if the awareness of seeing the environment as a semiotic layer and system can be sensitized to the insights of the ‘mobilities turn’. Empirically the paper tentatively explores the usefulness of a mobile semiotics approach to cases such as street signage, airport design...

  2. jQuery Mobile

    CERN Document Server

    Reid, Jon

    2011-01-01

    Native apps have distinct advantages, but the future belongs to mobile web apps that function on a broad range of smartphones and tablets. Get started with jQuery Mobile, the touch-optimized framework for creating apps that look and behave consistently across many devices. This concise book provides HTML5, CSS3, and JavaScript code examples, screen shots, and step-by-step guidance to help you build a complete working app with jQuery Mobile. If you're already familiar with the jQuery JavaScript library, you can use your existing skills to build cross-platform mobile web apps right now. This b

  3. Mobile Sensing Systems

    Science.gov (United States)

    Macias, Elsa; Suarez, Alvaro; Lloret, Jaime

    2013-01-01

    Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high. PMID:24351637

  4. Mobile sensing systems.

    Science.gov (United States)

    Macias, Elsa; Suarez, Alvaro; Lloret, Jaime

    2013-12-16

    Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high.

  5. Mobile Sensing Systems

    Directory of Open Access Journals (Sweden)

    Elsa Macias

    2013-12-01

    Full Text Available Rich-sensor smart phones have made possible the recent birth of the mobile sensing research area as part of ubiquitous sensing which integrates other areas such as wireless sensor networks and web sensing. There are several types of mobile sensing: individual, participatory, opportunistic, crowd, social, etc. The object of sensing can be people-centered or environment-centered. The sensing domain can be home, urban, vehicular… Currently there are barriers that limit the social acceptance of mobile sensing systems. Examples of social barriers are privacy concerns, restrictive laws in some countries and the absence of economic incentives that might encourage people to participate in a sensing campaign. Several technical barriers are phone energy savings and the variety of sensors and software for their management. Some existing surveys partially tackle the topic of mobile sensing systems. Published papers theoretically or partially solve the above barriers. We complete the above surveys with new works, review the barriers of mobile sensing systems and propose some ideas for efficiently implementing sensing, fusion, learning, security, privacy and energy saving for any type of mobile sensing system, and propose several realistic research challenges. The main objective is to reduce the learning curve in mobile sensing systems where the complexity is very high.

  6. Evaluation of the influence of the use of waste from the processing of rice in physicochemical properties and biodegradability of PHB in composites

    Directory of Open Access Journals (Sweden)

    Ana Paula Wünsch Boitt

    2014-12-01

    Full Text Available The high calorific value of rice husks has elevated its reuse as an energy source; however, the burning of these shells generates a waste ash from rice husk ash (RHA, which makes its disposal a concern. Despite advances, biodegradable polymers are not yet able to compete with those of traditional thermoplastics, which have lower production cost and higher performance. Based on this background, this paper studies the feasibility of reuse of RHA as filler in polymer matrices replacing the conventional filler. This study consists of applying different percentages of RHA in the formulation of polyhydroxybutyrate composite (PHB and the use of talc (TA for comparison purposes as conventional filler. The composites used in this assay were obtained by twin-screw extrusion and injection molding of the polymer plus the fillers under study. Physicochemical and biodegradability properties of the composites were evaluated. The composite PHB/RHA was superior in the biodegradability tests and the properties remain practically unchanged in the presence of the filler. Thus, composites with RHA are promising because they take an abundant residue combined with degradation capacity of the polymer, therefore reducing cost and the environmental impact.

  7. Footprint area analysis of binary imaged Cupriavidus necator cells to study PHB production at balanced, transient, and limited growth conditions in a cascade process.

    Science.gov (United States)

    Vadlja, Denis; Koller, Martin; Novak, Mario; Braunegg, Gerhart; Horvat, Predrag

    2016-12-01

    Statistical distribution of cell and poly[3-(R)-hydroxybutyrate] (PHB) granule size and number of granules per cell are investigated for PHB production in a five-stage cascade (5CSTR). Electron microscopic pictures of cells from individual cascade stages (R1-R5) were converted to binary pictures to visualize footprint areas for polyhydroxyalkanoate (PHA) and non-PHA biomass. Results for each stage were correlated to the corresponding experimentally determined kinetics (specific growth rate μ and specific productivity π). Log-normal distribution describes PHA granule size dissimilarity, whereas for R1 and R4, gamma distribution best reflects the situation. R1, devoted to balanced biomass synthesis, predominately contains cells with rather small granules, whereas with increasing residence time τ, maximum and average granule sizes by trend increase, approaching an upper limit determined by the cell's geometry. Generally, an increase of intracellular PHA content and ratio of granule to cell area slow down along the cascade. Further, the number of granules per cell decreases with increasing τ. Data for μ and π obtained by binary picture analysis correlate well with the experimental results. The work describes long-term continuous PHA production under balanced, transient, and nutrient-deficient conditions, as well as their reflection on the granules size, granule number, and cell structure on the microscopic level.

  8. TSD current investigations in pristine and 100 MeV Ni-ion irradiated PET/0.3 PHB polymer liquid crystal

    International Nuclear Information System (INIS)

    Quamara, J.K.; Singh, Nafa; Prabhavathi, T.; Sridharbabu, Y.

    2002-01-01

    The dielectric relaxations investigations have been carried out in pristine as well as 100 MeV 58 Ni ion irradiated (PELLETRON facility, Nuclear Science Center, New Delhi) PET/0.3 PHB PLC samples. Thermally stimulated depolarization current technique (TSDC) has been employed for this purpose. The plc samples were polarized at 180 deg C under the influence of various polarizing fields following the usual method. Three current maxima are observed around 35deg, 120deg and 155degC which are ascribed as β', β and α transitions. These transitions are mainly due to the fast reacting dipoles of PHB regions, dipolar character due to carbonyl groups in PET rich phase and to the cold crystallization of PET. The results confirm the biphasic nature of this plc. The high energy irradiation influences both β and α transitions. Increase in fluence shifts the β peak as well as α peak towards higher temperature. This confirms that high energy irradiation has not only affected the carbonyl groups but has created new phases. (author)

  9. Bacterial Community and PHB-Accumulating Bacteria Associated with the Wall and Specialized Niches of the Hindgut of the Forest Cockchafer (Melolontha hippocastani).

    Science.gov (United States)

    Alonso-Pernas, Pol; Arias-Cordero, Erika; Novoselov, Alexey; Ebert, Christina; Rybak, Jürgen; Kaltenpoth, Martin; Westermann, Martin; Neugebauer, Ute; Boland, Wilhelm

    2017-01-01

    A characterization of the bacterial community of the hindgut wall of two larval and the adult stages of the forest cockchafer ( Melolontha hippocastani ) was carried out using amplicon sequencing of the 16S rRNA gene fragment. We found that, in second-instar larvae, Caulobacteraceae and Pseudomonadaceae showed the highest relative abundances, while in third-instar larvae, the dominant families were Porphyromonadaceae and Bacteroidales-related. In adults, an increase of the relative abundance of Bacteroidetes, Proteobacteria (γ- and δ- classes) and the family Enterococcaceae (Firmicutes) was observed. This suggests that the composition of the hindgut wall community may depend on the insect's life stage. Additionally, specialized bacterial niches hitherto very poorly described in the literature were spotted at both sides of the distal part of the hindgut chamber. We named these structures "pockets." Amplicon sequencing of the 16S rRNA gene fragment revealed that the pockets contained a different bacterial community than the surrounding hindgut wall, dominated by Alcaligenaceae and Micrococcaceae-related families. Poly-β-hydroxybutyrate (PHB) accumulation in the pocket was suggested in isolated Achromobacter sp. by Nile Blue staining, and confirmed by gas chromatography-mass spectrometry analysis (GC-MS) on cultured bacterial mass and whole pocket tissue. Raman micro-spectroscopy allowed to visualize the spatial distribution of PHB accumulating bacteria within the pocket tissue. The presence of this polymer might play a role in the colonization of these specialized niches.

  10. Biological Properties of Low-Toxicity PLGA and PLGA/PHB Fibrous Nanocomposite Implants for Osseous Tissue Regeneration. Part I: Evaluation of Potential Biotoxicity

    Directory of Open Access Journals (Sweden)

    Izabella Krucińska

    2017-11-01

    Full Text Available In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide-co-glycolide (PLGA and syntheticpoly([R,S]-3-hydroxybutyrate, PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes.

  11. Mobile Clouds

    DEFF Research Database (Denmark)

    Fitzek, Frank; Katz, Marcos

    A mobile cloud is a cooperative arrangement of dynamically connected communication nodes sharing opportunistic resources. In this book, authors provide a comprehensive and motivating overview of this rapidly emerging technology. The book explores how distributed resources can be shared by mobile...... users in very different ways and for various purposes. The book provides many stimulating examples of resource-sharing applications. Enabling technologies for mobile clouds are also discussed, highlighting the key role of network coding. Mobile clouds have the potential to enhance communications...... performance, improve utilization of resources and create flexible platforms to share resources in very novel ways. Energy efficient aspects of mobile clouds are discussed in detail, showing how being cooperative can bring mobile users significant energy saving. The book presents and discusses multiple...

  12. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix; Wind, Simon

    2016-01-01

    In this paper, we identify the nexus between design (architecture, urban design, service design, etc.) and mobilities as a new and emerging research field. In this paper, we apply a “situational mobilities” perspective and take point of departure in the pragmatist question: “What design decisions...... and interventions affords this particular mobile situation?” The paper presents the contours of an emerging research agenda within mobilities research. The advent of “mobilities design” as an emerging research field points towards a critical interest in the material as well as practical consequences of contemporary......-making. The paper proposes that increased understanding of the material affordances facilitated through design provides important insight to planning and policymaking that at times might be in risk of becoming too detached from the everyday life of the mobile subject within contemporary mobilities landscapes....

  13. Mobiles Robotersystem

    OpenAIRE

    Schmierer, G.; Wolf, A.

    1999-01-01

    DE 19816893 A UPAB: 20000203 NOVELTY - An optical and or acoustic noticeable advertising and or information carrier (10) is fixed permitting detachment in such a manner at the mobile platform (8), that the advertising and or information carrier does not impair the movability of the mobile platform. The advertising is provided at an exposed place on the mobile platform. USE - Advertising or information communication. ADVANTAGE - Advertising or information is imparted in prominent positioning w...

  14. The complete genome sequencing of Prevotella intermedia strain OMA14 and a subsequent fine-scale, intra-species genomic comparison reveal an unusual amplification of conjugative and mobile transposons and identify a novel Prevotella-lineage-specific repeat.

    Science.gov (United States)

    Naito, Mariko; Ogura, Yoshitoshi; Itoh, Takehiko; Shoji, Mikio; Okamoto, Masaaki; Hayashi, Tetsuya; Nakayama, Koji

    2016-02-01

    Prevotella intermedia is a pathogenic bacterium involved in periodontal diseases. Here, we present the complete genome sequence of a clinical strain, OMA14, of this bacterium along with the results of comparative genome analysis with strain 17 of the same species whose genome has also been sequenced, but not fully analysed yet. The genomes of both strains consist of two circular chromosomes: the larger chromosomes are similar in size and exhibit a high overall linearity of gene organizations, whereas the smaller chromosomes show a significant size variation and have undergone remarkable genome rearrangements. Unique features of the Pre. intermedia genomes are the presence of a remarkable number of essential genes on the second chromosomes and the abundance of conjugative and mobilizable transposons (CTns and MTns). The CTns/MTns are particularly abundant in the second chromosomes, involved in its extensive genome rearrangement, and have introduced a number of strain-specific genes into each strain. We also found a novel 188-bp repeat sequence that has been highly amplified in Pre. intermedia and are specifically distributed among the Pre. intermedia-related species. These findings expand our understanding of the genetic features of Pre. intermedia and the roles of CTns and MTns in the evolution of bacteria. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  15. Association of PHB 1630 C > T and MTHFR 677 C > T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study

    NARCIS (Netherlands)

    Jakubowska, A.; Rozkrut, D.; Antoniou, A.; Hamann, U.; Scott, R. J.; McGuffog, L.; Healy, S.; Sinilnikova, O. M.; Rennert, G.; Lejbkowicz, F.; Flugelman, A.; Andrulis, I. L.; Glendon, G.; Ozcelik, H.; Thomassen, M.; Paligo, M.; Aretini, P.; Kantala, J.; Aroer, B.; Von Wachenfeldt, A.; Liljegren, A.; Loman, N.; Herbst, K.; Kristoffersson, U.; Rosenquist, R.; Karlsson, P.; Stenmark-Askmalm, M.; Melin, B.; Nathanson, K. L.; Domchek, S. M.; Byrski, T.; Huzarski, T.; Gronwald, J.; Menkiszak, J.; Cybulski, C.; Serrano, P.; Osorio, A.; Cajal, T. R.; Tsitlaidou, M.; Benítez, J.; Gilbert, M.; Rookus, M.; Aalfs, C. M.; Kluijt, I.; Boessenkool-Pape, J. L.; Meijers-Heijboer, H. E. J.; Oosterwijk, J. C.; van Asperen, C. J.; Blok, M. J.; Nelen, M. R.; van den Ouweland, A. M. W.; Seynaeve, C.; van der Luijt, R. B.; Devilee, P.; Easton, D. F.; Peock, S.; Frost, D.; Platte, R.; Ellis, S. D.; Fineberg, E.; Evans, D. G.; Lalloo, F.; Eeles, R.; Jacobs, C.; Adlard, J.; Davidson, R.; Eccles, D.; Cole, T.; Cook, J.; Godwin, A.; Bove, B.; Stoppa-Lyonnet, D.; Caux-Moncoutier, V.; Belotti, M.; Tirapo, C.; Mazoyer, S.; Barjhoux, L.; Boutry-Kryza, N.; Pujol, P.; Coupier, I.; Peyrat, J.-P.; Vennin, P.; Muller, D.; Fricker, J.-P.; Venat-Bouvet, L.; Johannsson, O. Th; Isaacs, C.; Schmutzler, R.; Wappenschmidt, B.; Meindl, A.; Arnold, N.; Varon-Mateeva, R.; Niederacher, D.; Sutter, C.; Deissler, H.; Preisler-Adams, S.; Simard, J.; Soucy, P.; Durocher, F.; Chenevix-Trench, G.; Beesley, J.; Chen, X.; Rebbeck, T.; Couch, F.; Wang, X.; Lindor, N.; Fredericksen, Z.; Pankratz, V. S.; Peterlongo, P.; Bonanni, B.; Fortuzzi, S.; Peissel, B.; Szabo, C.; Mai, P. L.; Loud, J. T.; Lubinski, J.; Peock, Susan; Frost, Debra; Platte, Radka; Ellis, Steve D.; Fineberg, Elena; Miedzybrodzka, Zosia; Gregory, Helen; Morrison, Patrick; Jeffers, Lisa; Cole, Trevor; Ong, Kai-Ren; Hoffman, Jonathan; Donaldson, Alan; James, Margaret; Paterson, Joan; Downing, Sarah; Taylor, Amy; Murray, Alexandra; Rogers, Mark T.; McCann, Emma; Kennedy, M. John; Barton, David; Porteous, Mary; Drummond, Sarah; Brewer, Carole; Kivuva, Emma; Searle, Anne; Goodman, Selina; Hill, Kathryn; Davidson, Rosemarie; Murday, Victoria; Bradshaw, Nicola; Snadden, Lesley; Longmuir, Mark; Watt, Catherine; Gibson, Sarah; Haque, Eshika; Tobias, Ed; Duncan, Alexis; Izatt, Louise; Jacobs, Chris; Langman, Caroline; Whaite, Anna; Dorkins, Huw; Barwell, Julian; Adlard, Julian; Chu, Carol; Miller, Julie; Ellis, Ian; Houghton, Catherine; Evans, D. Gareth; Lalloo, Fiona; Taylor, Jane; Side, Lucy; Male, Alison; Berlin, Cheryl; Eason, Jacqueline; Collier, Rebecca; Douglas, Fiona; Claber, Oonagh; Jobson, Irene; Walker, Lisa; McLeod, Diane; Halliday, Dorothy; Durell, Sarah; Stayner, Barbara; Eeles, Ros; Shanley, Susan; Rahman, Nazneen; Houlston, Richard; Bancroft, Elizabeth; D'Mello, Lucia; Page, Elizabeth; Ardern-Jones, Audrey; Kohut, Kelly; Wiggins, Jennifer; Castro, Elena; Mitra, Anita; Robertson, Lisa; Cook, Jackie; Quarrell, Oliver; Bardsley, Cathryn; Hodgson, Shirley; Goff, Sheila; Brice, Glen; Winchester, Lizzie; Eddy, Charlotte; Tripathi, Vishakha; Attard, Virginia; Eccles, Diana; Lucassen, Anneke; Crawford, Gillian; McBride, Donna; Smalley, Sarah; Sinilnikova, Olga; Mazoyer, Sylvie; Barjhoux, Laure; Verny-Pierre, Carole; Giraud, Sophie; Léone, Mélanie; Stoppa-Lyonnet, Dominique; Gauthier-Villars, Marion; Buecher, Bruno; Houdayer, Claude; Moncoutier, Virginie; Belotti, Muriel; Tirapo, Carole; de Pauw, Antoine; Bressac-de-Paillerets, Brigitte; Byrde, Véronique; Caron, Olivier; Lenoir, Gilbert; Bignon, Yves-Jean; Uhrhammer, Nancy; Lasset, Christine; Bonadona, Valérie; Hardouin, Agnès; Berthet, Pascaline; Sobol, Hagay; Bourdon, Violaine; Noguchi, Tetsuro; Remenieras, Audrey; Eisinger, François; Coulet, Florence; Colas, Chrystelle; Soubrier, Florent; Coupier, Isabelle; Pujol, Pascal; Peyrat, Jean-Philippe; Fournier, Joëlle; Révillion, Françoise; Vennin, Philippe; Adenis, Claude; Rouleau, Etienne; Lidereau, Rosette; Demange, Liliane; Nogues, Catherine; Muller, Danièle; Fricker, Jean-Pierre; Barouk-Simonet, Emmanuelle; Bonnet, Françoise; Bubien, Virginie; Sevenet, Nicolas; Longy, Michel; Toulas, Christine; Guimbaud, Rosine; Gladieff, Laurence; Feillel, Viviane; Leroux, Dominique; Dreyfus, Hélène; Rebischung, Christine; Peysselon, Magalie; Coron, Fanny; Faivre, Laurence; Prieur, Fabienne; Lebrun, Marine; Kientz, Caroline; Ferrer, Sandra Fert; Frénay, Marc; Vénat-Bouvet, Laurence; Delnatte, Capucine; Mortemousque, Isabelle; Lynch, Henry T.; Snyder, Carrie L.; Hogervorst, F. B. L.; Verhoef, S.; Verheus, M.; van't Veer, L. J.; van Leeuwen, F. E.; Rookus, M. A.; Collée, M.; Jager, A.; Hooning, M. J.; Tilanus-Linthorst, M. M. A.; Wijnen, J. T.; Vreeswijk, M. P.; Tollenaar, R. A.; Ligtenberg, M. J.; Hoogerbrugge, N.; Ausems, M. G.; van Os, T. A.; Gille, J. J. P.; Waisfisz, Q.; Gomez-Garcia, E. B.; van Roozendaal, C. E.; Blok, Marinus J.; Caanen, B.; van der Hout, A. H.; Mourits, M. J.; Vasen, H. F.; Szabo, C. I.; Zikan, Michal; Pohlreich, Petr; Kleibl, Zdenek; Foretova, Lenka; Eva, Machackova; Miroslava, Lukesova; Claes, Kathleen; de Leeneer, Kim; Poppe, Bruce; de Paepe, Anne; Karlsson, Per; Nordling, Margareta; Bergman, Annika; Einbeigi, Zakaria; Stenmark-Askmalm, Marie; Liedgren, Sigrun; Borg, Ake; Loman, Niklas; Olsson, Håkan; Soller, Maria; Jernström, Helena; Harbst, Katja; Henriksson, Karin; Lindblom, Annika; Arver, Brita; von Wachenfeldt, Anna; Liljegren, Annelie; Barbany-Bustinza, Gisela; Rantala, Johanna; Melin, Beatrice; Grönberg, Henrik; Stattin, Eva-Lena; Emanuelsson, Monica; Ehrencrona, Hans; Rosenquist, Richard; Dahl, Niklas

    2012-01-01

    BACKGROUND: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either

  16. Mobil marketing

    OpenAIRE

    Engelová, Kateřina

    2006-01-01

    Mobil marketing - reklama a podpora prodeje prostřednictvím mobilních telefonů. Technologické a kulturní předpoklady vzniku tohoto odvětví. Mobil marketing a marketingový mix, možnosti synergie. Nástroje mobil marketingu - reklamní SMS a MMS, lokační služby, soutěže, ankety a hlasování, věrnostní systémy, mobilní obsah. Subjekty mobil marketingu. M-komerce. Využití pro podnikové aplikace.

  17. Culture engineering examination and metabolism flux distribution system analysis for madding to convert into poly {beta}- hydroxybutyric acid (PHB) using the hydrogen bacteria of organic acid got in liquid-phase oxidation of lignite; Kattan no ekiso sanka de erareru yukisan wo suiso saikin wo riyoshite pori {beta}-hidorokishi rakusan(PHB) ni henkan saseru tameno baiyo kogakuteki kento to taisha ryusoku bunpu shisutemu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, Kinko; Seki, Suito; Shimizu, Kazuyuki; Mae, Kazuhiro; Miura, Koichi

    1999-04-05

    The culture engineering examination for madding to convert into poly {beta} - hydroxy Wisteria (PHB) which glycolic acid. Acetic acid, ant acid, malonic acid got in liquid-phase oxidation of lignite are raw material of biodegradable plastic using hydrogen bacteria Alcaligenes eutrophus was carried out. It was proven that acetic acid was the most efficiently converted into the PHB as a result of cultivating these organic acid as a single carbon source. And, it was utilized to the bacterial cell at the order of ant acid, acetic acid, glycolic acid, when it was cultivated in mixing organic acid, and it was proven to convert into the PHB. Though the malonic acid was not utilized for the bacterial cell breeding, it was indicated that as the result which analyzed metabolism flow distribution by calculating using the culture data, the succinate dehydrogenase of the tricarboxylic acid (TCA) circuit received competitive inhibition, when this is added in culture middle point, and that the flux of griot lysyl acid route and gluconeogenesis route lowers. And, it was proven that it was utilized in the route which comes to the PHB synthesis from acetoacetyl CoA with the lowering of the ammonia concentration on NADPH produced from the isocitric acid, though it was prior consumed to the glutamic acid of tricarboxylic acid cycle in the route, if ammonia concentration is high. (translated by NEDO)

  18. Mobile phones and mobile communication

    DEFF Research Database (Denmark)

    Ling, Richard; Donner, Jonathan

    With staggering swiftness, the mobile phone has become a fixture of daily life in almost every society on earth. In 2007, the world had over 3 billion mobile subscriptions. Prosperous nations boast of having more subscriptions than people. In the developing world, hundreds of millions of people who...... could never afford a landline telephone now have a mobile number of their own. With a mobile in our hand many of us feel safer, more productive, and more connected to loved ones, but perhaps also more distracted and less involved with things happening immediately around us. Written by two leading...... researchers in the field, this volume presents an overview of the mobile telephone as a social and cultural phenomenon. Research is summarized and made accessible though detailed descriptions of ten mobile users from around the world. These illustrate popular debates, as well as deeper social forces at work...

  19. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different...

  20. Urban Mobility

    DEFF Research Database (Denmark)

    2017-01-01

    This anthology is the proceedings publication from the 2015 NAF Symposium in Malmö, Sweden. The aim of the 2015 NAF Symposium “Urban Mobility – Architectures, Geographies and Social Space” was to facilitate a cross-disciplinary discussion on urban mobility in which the juxtaposition of different ...

  1. Mobile phone

    International Nuclear Information System (INIS)

    2009-01-01

    Almost the entire Norwegian population has cell phone. The usefulness of the cell phone is great, but can use a mobile phone to health or discomfort? How can exposure be reduced? NRPA follows research and provides advice on mobile phone use. (AG)

  2. Intensive mobilities

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    with fieldwork conducted in Canada, Denmark and Australia to develop our understanding of the experiential politics of long distance workers. Rather than focusing on the extensive dimensions of mobilities that are implicated in patterns and trends, our paper turns to the intensive dimensions of this experience......This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of factors...... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance mobilities have not received the attention that they deserve within geographical research on mobilities. This paper combines ideas from mobilities research and contemporary social theory...

  3. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    are often still not engaged with in a sufficiently manner. Often social sciences keep distance to the physical and material as if the social was still to be understood as a realm separate of technology, architecture, and design (for a critique of this see; Latour 2005 and Urry 2000). This paper takes point......Within the so-called ‘mobilities turn’ (Adey 2010; Cresswell 2006; Urry 2007) much research has taken place during the last decade bringing mobilities into the centre of sociological analysis. However, the materiality and spatiality of artefacts, infrastructures, and sites hosting mobilities...... of departure in the sociological perspective termed ‘Staging Mobilities’ (Jensen 2013a) and utilizes this as an analytical frame for exploring cases of mobility design. The paper put focus on how the material shape, design and architectures of technologies, spaces and sites influence mobilities practices...

  4. Mobile probes

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Jørgensen, Anna Neustrup; Noesgaard, Signe Schack

    2016-01-01

    A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed...... to in an interview. This method provided valuable insight into the contextual use, i.e. how did the online resource transfer to the work practice. However, the research team also found that mobile probes may provide the scaffolding necessary for individual and peer learning at a very local (intra-school) community...... level. This paper is an initial investigation of how the mobile probes process proved to engage teachers in their efforts to improve teaching. It also highlights some of the barriers emerging when applying mobile probes as a scaffold for learning....

  5. Mobilities Design

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lanng, Ditte Bendix

    2016-01-01

    of life’ for billions of people in the everyday life. This paper is structured in three parts. After the general introduction we present the mobilities theory perspective of ‘staging mobilities’ and connects this to the empirical phenomenon of parking lots and their design. The paper ends in section three......Contemporary society is marked and defined by the ways in which mobile goods, bodies, vehicles, objects, and data are organized, moved and staged. On the backgound of the ‘mobilities turn’ (for short review paper on this see; Sheller 2011, Vannini 2010) this paper proposes a further development...... of the perspective in the direction of a material and design oriented turn. In order to fulfill this purpose we articulate a new and emerging research field, namely that of ‘mobilities design’. In our understanding time has come to articulate ‘Mobilities Design’ as a dedicated research field in and of its own...

  6. Mobile Lexicography

    DEFF Research Database (Denmark)

    Køhler Simonsen, Henrik

    2015-01-01

    are already mobile – but lexicography is not yet fully ready for the mobile challenge, mobile users and mobile user situations. The article is based on empirical data from two surveys comprising 10 medical doctors, who were asked to look up five medical substances with the medical dictionary app Medicin.......dk and five students, who were asked to look up five terms with the dictionary app Gyldendal Engelsk-Dansk. The empirical data comprise approximately 15 hours of recordings of user behavior, think-aloud data and interview data. The data indicate that there is still much to be done in this area...... and that lexicographic innovation is needed. A new type of users, new user situations and new access methods call for new lexicographic solutions, and this article proposes a six-pointed hexagram model, which can be used during dictionary app design to lexicographically calibrate the six dimensions in mobile...

  7. Restricted Mobilities

    DEFF Research Database (Denmark)

    Nielsen, Mette; Lassen, Claus

    2012-01-01

    communities and shopping centres through mobility lenses. The article shows how different mobility systems enable and restrict the public access to private-public spaces, and it points out that proprietary communities create an unequal potential for human movement and access in the city. The main argument......Privatisation of public spaces in the contemporary city has increased during the last decades but only few studies have approached this field from a mobility perspective. Therefore the article seeks to rectify this by exploring two Australian examples of private spaces in the city; gated...... and stratification mechanisms. In conclusion the article therefore suggests that future urban research and planning also needs a mobile understanding of spaces in the cities and how different mobility systems play an important role to sustain the exclusiveness that often characterises the private/public spaces...

  8. Mobility Work

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Bossen, Claus

    2005-01-01

    We posit the concept of Mobility Work to describe efforts of moving about people and things as part of accomplishing tasks. Mobility work can be seen as a spatial parallel to the concept of articulation work proposed by the sociologist Anselm Strauss. Articulation work describes efforts of coordi....../or resources. To accomplish their work, actors have to make the right configuration of these four aspects emerge.......We posit the concept of Mobility Work to describe efforts of moving about people and things as part of accomplishing tasks. Mobility work can be seen as a spatial parallel to the concept of articulation work proposed by the sociologist Anselm Strauss. Articulation work describes efforts...... of coordination necessary in cooperative work, but focuses, we argue, mainly on the temporal aspects of cooperative work. As a supplement, the concept of mobility work focuses on the spatial aspects of cooperative work. Whereas actors seek to diminish the amount of articulation work needed in collaboration...

  9. Mobility Challenges

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lassen, Claus

    2011-01-01

    This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part...... of the so-called ‘mobility turn’ within social science. The perspective is illustrative for the research efforts at the Centre for Mobility and Urban Studies (C-MUS), Aalborg University. The article presents the contours of a theoretical perspective meeting the challenges to research into contemporary urban...... mobilities. In particular the article discusses 1) the physical city, its infrastructures and technological hardware/software, 2) policies and planning strategies for urban mobility and 3) the lived everyday life in the city and the region....

  10. Mobility Management Algorithms for the Client-Driven Mobility Frame System–Mobility from a Brand New Point of View

    Directory of Open Access Journals (Sweden)

    Péter Fülöp

    2009-01-01

    Full Text Available In this paper a new mobility management is introduced. The main idea in this approach is that the mobil node should manage the mobility for itself not the network. The network nodes provide only basic services for mobile entities: connectivity and administration. We construct a framework called the Client-based Mobility Frame System (CMFS for this mobility environment. We developed the CMFS protocol as a solution over IPv4 and we show how to use Mobile IPv6 to realize our concept. We propose some basic mobility management solutions that can be implemented into the mobile clients and give details about a working simulation of a complete Mobility Management System. Example mobility management approaches such as the centralized- and hierarchical- or cellular-like ones are also defined and hints are given what kind of algorithms might be implemented upon the Client-based Mobility Frame System over IPv4 and IPv6 as well. We introduce some example algorithms that can work with the CMFS making mobility management efficient by minimizing signalling load on the network. In the present work modeling and detailed discussion on the parameters of the algorithms is given and comparison to existing mobility approaches and protocols is done. We prepared a simulation to test our protocol and to back up the proposals we provide the reader with simulation results. We stress that still one the most important benefit of our findings is that all the MNs can run different management strategies and can optimize mobility for themselves.

  11. Lazy Mobile Intruders

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander; Nielson, Flemming; Nielson, Hanne Riis

    2013-01-01

    We present a new technique for analyzing platforms that execute potentially malicious code, such as web-browsers, mobile phones, or virtualized infrastructures. Rather than analyzing given code, we ask what code an intruder could create to break a security goal of the platform. To avoid searching...... that by communication, the malicious code can learn new information that it can use in subsequent operations, or that we may have several pieces of malicious code that can exchange information if they “meet”. To formalize both the platform and the malicious code we use the mobile ambient calculus, since it provides...... a small, abstract formalism that models the essence of mobile code. We provide a decision procedure for security against arbitrary intruder processes when the honest processes can only perform a bounded number of steps and without path constraints in communication. We show that this problem is NP-complete....

  12. Children, mobility, and space

    DEFF Research Database (Denmark)

    Christensen, Pia; Mikkelsen, Miguel Romero; Nielsen, Thomas Alexander Sick

    2011-01-01

    This article discusses the potentials of a mixed methods approach to the study of children’s mobility patterns. The methodology presented here combined ethnographic fieldwork with global positioning system technology and an interactive questionnaire that children completed via mobile phone....... This innovative methodology allowed the researchers to generate a rich understanding of children’s everyday movements. The study combined documentation of children’s subjective experiences with systematic observations, mapping, and survey data. The article sets out lessons learned for future mixed methods...... research into children’s everyday mobility. One such lesson was that it required the interdisciplinary research team to cooperate closely through dialogue, support, and coordination of activities and perspectives. The approach also promoted the children’s commitment to the study....

  13. Dielectric relaxation and spectroscopic investigation of poly hydroxybutyrate PHB blended with polyvinyl acetate PVAc and poly(vinylacetate-co-vinyl alcohol) PACA

    International Nuclear Information System (INIS)

    Abou-Aiad, T.H.M.; Abd-El-Nour, K.N.; Hakim, I.K.; El-Sabee, M.S.

    2005-01-01

    Using frequency response analyzer covering a frequency range from 102 - 106 Hz in a wide range of temperature, the dielectric behaviour of the investigated systems was studied. In order to investigate the relaxation mechanisms of such systems, the dielectric loss data on the frequency domain were analysed using Havriliak-Nagami and/or Frohlich functions in addition to the conductivity term. These mechanisms are discussed in terms of the orientation of the main chain and its related motions. The relaxation times related to both mechanisms noticed for PHB/PVAc blend with composition 50% are found to be higher than those for other compositions. This could be attributed to the interaction that expected through hydrogen bond formation. This result is supported by the data given by FTIR spectroscopy as the carbonyl region at 1750 cm-1 showed a more broad band spectrum when compared with those for the other compositions

  14. Sustainable Mobility

    DEFF Research Database (Denmark)

    Kjærulff, Aslak Aamot

    This paper combines strands of mobilities theory and planning theory, and develops a qualitative approach to look across emerging planning practices. By actively following 8 Danish urban and transport planners, over the course of 2 years, we learn how their practices have changed, inspired...... by mobility management, a concept aiming to reduce carbon emissions from transportation in western societies. The article focuses on how municipal planners formulate the role of mobility management activities organized around private companies, and how their practices are connected to wider ideas on planning....

  15. Latino College Completion: Hawaii

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  16. Latino College Completion: Pennsylvania

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  17. Completeness, supervenience and ontology

    International Nuclear Information System (INIS)

    Maudlin, Tim W E

    2007-01-01

    In 1935, Einstein, Podolsky and Rosen raised the issue of the completeness of the quantum description of a physical system. What they had in mind is whether or not the quantum description is informationally complete, in that all physical features of a system can be recovered from it. In a collapse theory such as the theory of Ghirardi, Rimini and Weber, the quantum wavefunction is informationally complete, and this has often been taken to suggest that according to that theory the wavefunction is all there is. If we distinguish the ontological completeness of a description from its informational completeness, we can see that the best interpretations of the GRW theory must postulate more physical ontology than just the wavefunction

  18. Completeness, supervenience and ontology

    Energy Technology Data Exchange (ETDEWEB)

    Maudlin, Tim W E [Department of Philosophy, Rutgers University, 26 Nichol Avenue, New Brunswick, NJ 08901-1411 (United States)

    2007-03-23

    In 1935, Einstein, Podolsky and Rosen raised the issue of the completeness of the quantum description of a physical system. What they had in mind is whether or not the quantum description is informationally complete, in that all physical features of a system can be recovered from it. In a collapse theory such as the theory of Ghirardi, Rimini and Weber, the quantum wavefunction is informationally complete, and this has often been taken to suggest that according to that theory the wavefunction is all there is. If we distinguish the ontological completeness of a description from its informational completeness, we can see that the best interpretations of the GRW theory must postulate more physical ontology than just the wavefunction.

  19. Complete Ureteral Avulsion

    Directory of Open Access Journals (Sweden)

    V. Gupta

    2005-01-01

    Full Text Available Complete avulsion of the ureter is one of the most serious complications of ureteroscopy. It requires open or laparoscopic intervention for repair. This case report emphasizes its management and presents recommendations for prevention in current urological practice.

  20. Virtualization techniques for mobile systems

    CERN Document Server

    Jaramillo, David; Agarwal, Ankur

    2014-01-01

    This book presents effective ways to partition mobile devices such that the enterprise system access and its information are completely separated from the personal information. For those using mobile devices for personal and business purposes, the ability to keep the data secure and separate is critical. The applications for security in smart platforms range from personal email accounts to global enterprise systems.Several approaches for mobile virtualization are described, all creating secure and secluded environments for enterprise information. The authors present a reference architecture th

  1. Mobile Marketing

    OpenAIRE

    竹安, 数博; Takeyasu, Kazuhiro

    2005-01-01

    This article deals with one of the modern trends in marketing communication, which is mobile marketing. Towards the end of 2008, several projects which use mobile phones for target marketing communication were launched. Commercial SMS´s are sent on the base of agreement or registration of the consumers on special websites, for example hellomobil.cz. The benefit for the consumers is the bonus which can have more forms - not only sending money to the account, free SMS´s/MMS´s and minutes but al...

  2. Mobile Usability

    DEFF Research Database (Denmark)

    Aryana, Bijan; Clemmensen, Torkil

    2013-01-01

    In this article, a country specific comparative mobile usability study is presented, using Iran and Turkey as the two chosen emerging/emergent nation exemplars of smartphone usage and adoption. In a focus group study, three mobile applications were selected by first-time users of smartphones...... personal contacts. The results and analysis establish the existence of country specific issues and concerns, as well as reveal generic usability issues. The article concludes that the source of these issues is most likely due to a combination of certain contextual features endemic to both Iran and Turkey...

  3. Production and characterization of a biodegradable poly (hydroxybutyrate-co-hydroxyvalerate) (PHB-co-PHV) copolymer by moderately haloalkalitolerant Halomonas campisalis MCM B-1027 isolated from Lonar Lake, India.

    Science.gov (United States)

    Kulkarni, S O; Kanekar, P P; Nilegaonkar, S S; Sarnaik, S S; Jog, J P

    2010-12-01

    Several microorganisms produce polyhydroxyalkanoates (PHA). They are accumulated intracellularly as energy storage compounds. The PHAs are of interest because of their potential in biomedical applications. Halophilic bacteria and archaea are known to produce polyhydroxybutyrate (PHB). This paper describes production of a biodegradable copolymer, PHB-co-PHV by a moderately haloalkalitolerant Halomonas campisalis, isolated from Lonar Lake, India. The production of PHA was in the range of 45-81% on dry cell weight basis when the organism was grown in a production medium containing 1% (w/v) maltose and 0.1% (w/v) yeast extract, at pH ranging from 6 to 9 with an inoculum density of 10(5)-10(7) cells/ml of medium, for incubation period of 15-30 h and at 37 degrees C. The polymer produced by the organism is a hydroxyester with molecular weight of 1.3014 x 10(6). Its melting temperature was 171 degrees C. The (1)H NMR analysis revealed that the polymer was a copolymer of PHB-co-PHV. This could be achieved by providing simple carbon source viz. maltose. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Designing Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    How is the width of the pavement shaping the urban experience? How is the material design of transport infrastructure and mobile technology affording social interaction in everyday life spaces? How do people inhabit these spaces with their bodies and in accordance to social and cultural norms...

  5. Mobile IP

    NARCIS (Netherlands)

    Heijenk, Geert; Sallent, S.; Pras, Aiko

    1999-01-01

    The Internet is growing exponentially, both in the amount of traffic carried, and in the amount of hosts connected. IP technology is becoming more and more important, in company networks (Intranets), and also in the core networks for the next generation mobile networks. Further, wireless access to

  6. Mobile Misfortune

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2015-01-01

    of the mobility it enables. This article, thus, looks at the motives and manners in which young men in Bissau become caught up in transnational flows of cocaine. It shows how motion is emotively anchored and affectively bound: tied to and directed toward a feeling of worth and realisation of being, and how...

  7. Going Mobile?

    DEFF Research Database (Denmark)

    Tallon, Loic; Froes, Isabel Cristina G.

    2011-01-01

    If the future is mobile, how is the museum community developing within that future? What are the challenges museums face within it? In which directions should we be seeking to evolve our collective knowledge share? It was to gain observations on questions such as these that the 2011 Museums & Mob...

  8. Resource Mobilization

    International Development Research Centre (IDRC) Digital Library (Canada)

    Annex 1: The Scoping Study on Donor Funding for. Development Research in ... publication of the Resource Mobilization: A Practical Guide for Research .... applied the concept or technique, which validates the practical application of ... some other staff member would write up a grant application addressed to one, two, or a ...

  9. Mobile Phone

    Institute of Scientific and Technical Information of China (English)

    籍万杰

    2004-01-01

    Your mobile phone rings.and instead of usual electronic signals,it's playing your favorite music.A friend sends your favorite song to cheer you up.One day,a record company might forward new records and music videos to your phone.

  10. Completeness of Lyapunov Abstraction

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Sloth, Christoffer

    2013-01-01

    the vector field, which allows the generation of a complete abstraction. To compute the functions that define the subdivision of the state space in an algorithm, we formulate a sum of squares optimization problem. This optimization problem finds the best subdivisioning functions, with respect to the ability......This paper addresses the generation of complete abstractions of polynomial dynamical systems by timed automata. For the proposed abstraction, the state space is divided into cells by sublevel sets of functions. We identify a relation between these functions and their directional derivatives along...

  11. MAPEAMENTO TECNOLÓGICO DO PROCESSO DE OBTENÇÃO DO PHB ATRAVÉS DA ANÁLISE DE PEDIDOS DE PATENTES

    Directory of Open Access Journals (Sweden)

    Larissa Alves de Sousa Costa

    2013-06-01

    Full Text Available Os polihidroxialcanoatos (PHAs são os únicos polímeros de origem microbiana totalmente biodegradável. Eles são sintetizados por diversos microrganismos, possuindo, após extração, propriedades semelhantes ao polipropileno. O polihidroxibutirato (PHB é o polímero mais comum da família dos PHAs e historicamente é o que tem sido mais estudado, ele é obtido a partir da bactéria Cupriavidus necator por fermentação da glicose em meio limitante de fonte de nitrogênio ou fósforo. Devido à importância econômica deste biopolímero, o objetivo deste trabalho foi analisar as potencialidades, características e evolução das competências tecnológicas, traduzidas através de documentos de patentes, no que diz respeito à obtenção do PHB no período de 1979 a 2010. Para tanto, foram analisados banco de dados do Espacenet, do Derwent Innovations Index, do United States Patent and Trademark Office e do Instituto Nacional de Propriedades Industrial. Foram realizadas buscas em relação à evolução anual das patentes depositadas, a origem da tecnologia, os detentores da tecnologia e principais inventores. Os códigos de Classificação Internacional de Patentes de maior incidência no Espacenet e no INPI são das classes C12 (bioquímica e mutações de engenharia genética e C08L (composições de compostos orgânicos macromoleculares, respectivamente. Nas bases pesquisadas, as empresas depositaram mais documentos que as universidades e os centros de pesquisa, sendo os anos de 2006 e 2009 os de maior relevância. Dos países pesquisados, os Estados Unidos foi o que apresentou maior número de registros (34%. O Brasil ainda possui poucas patentes na área, sendo necessários mais incentivos que visem aumentar o cenário inovativo do país.

  12. Construction completion report

    International Nuclear Information System (INIS)

    1990-01-01

    This Construction Completion Report documents the major construction projects at the Waste Isolation Pilot Plant (WIPP) site and related information on contracts, schedules, and other areas which affected construction. This report is not intended to be an exhaustive detailed analysis of construction, but is a general overview and summary of the WIPP construction. 10 refs., 29 figs

  13. Complete Rerouting Protection

    DEFF Research Database (Denmark)

    Stidsen, Thomas K.; Kjærulff, Peter

    2005-01-01

    In this paper we present a new protection method: Complete Rerouting. This is the most capacity e cient protection method for circuit switched networks and it is, to the best of our knowledge, the first time it has been described. We implement a column generation algorithm and test the performance...

  14. Complete French Teach Yourself

    CERN Document Server

    Graham, Gaelle

    2010-01-01

    The best-selling complete course for a fun and effective way to learn French. This ISBN is for the paperback book. The corresponding audio support (ISBN: 9781444100068) is also available. The book and audio support can also be purchased as a pack (ISBN: 9781444100051).

  15. Completeness of Lyapunov Abstraction

    Directory of Open Access Journals (Sweden)

    Rafael Wisniewski

    2013-08-01

    Full Text Available In this work, we continue our study on discrete abstractions of dynamical systems. To this end, we use a family of partitioning functions to generate an abstraction. The intersection of sub-level sets of the partitioning functions defines cells, which are regarded as discrete objects. The union of cells makes up the state space of the dynamical systems. Our construction gives rise to a combinatorial object - a timed automaton. We examine sound and complete abstractions. An abstraction is said to be sound when the flow of the time automata covers the flow lines of the dynamical systems. If the dynamics of the dynamical system and the time automaton are equivalent, the abstraction is complete. The commonly accepted paradigm for partitioning functions is that they ought to be transversal to the studied vector field. We show that there is no complete partitioning with transversal functions, even for particular dynamical systems whose critical sets are isolated critical points. Therefore, we allow the directional derivative along the vector field to be non-positive in this work. This considerably complicates the abstraction technique. For understanding dynamical systems, it is vital to study stable and unstable manifolds and their intersections. These objects appear naturally in this work. Indeed, we show that for an abstraction to be complete, the set of critical points of an abstraction function shall contain either the stable or unstable manifold of the dynamical system.

  16. Dual completion method

    Energy Technology Data Exchange (ETDEWEB)

    Mamedov, N Ya; Kadymova, K S; Dzhafarov, Sh T

    1963-10-28

    One type of dual completion method utilizes a single tubing string. Through the use of the proper tubing equipment, the fluid from the low-productive upper formation is lifted by utilizing the surplus energy of a submerged pump, which handles the production from the lower stratum.

  17. A complete woman

    Indian Academy of Sciences (India)

    Lawrence

    treated me like a son in the way he encouraged my education, while my mother ... cine gives me a lot of satisfaction when I see my patients getting cured. Teaching ... thing in life as a complete woman in different roles – daughter, wife, mother ...

  18. Mobile Customer Relationship Management and Mobile Security

    Science.gov (United States)

    Sanayei, Ali; Mirzaei, Abas

    The purpose of this study is twofold. First, in order to guarantee a coherent discussion about mobile customer relationship management (mCRM), this paper presents a conceptualization of mCRM delineating its unique characteristics because of Among the variety of mobile services, considerable attention has been devoted to mobile marketing and in particular to mobile customer relationship management services. Second, the authors discusses the security risks in mobile computing in different level(user, mobile device, wireless network,...) and finally we focus on enterprise mobile security and it's subgroups with a series of suggestion and solution for improve mobile computing security.

  19. The African Mobile Story

    DEFF Research Database (Denmark)

    This book identifies the factors that has enabled the growth of mobile telephony in Africa. The book covers the regulatory factors, the development and usage of mobile application, mobile security and sustainable power source for mobile networks...

  20. The complete cosmicomics

    CERN Document Server

    Calvino, Italo

    2014-01-01

    The definitive edition of Calvino’s cosmicomics, bringing together all of these enchanting stories—including some never before translated—in one volume for the first time. In Italo Calvino’s cosmicomics, primordial beings cavort on the nearby surface of the moon, play marbles with atoms, and bear ecstatic witness to Earth’s first dawn. Exploring natural phenomena and the origins of the universe, these beloved tales relate complex scientific concepts to our common sensory, emotional, human world. Now, The Complete Cosmicomics brings together all of the cosmicomic stories for the first time. Containing works previously published in Cosmicomics, t zero, and Numbers in the Dark, this single volume also includes seven previously uncollected stories, four of which have never been published in translation in the United States. This “complete and definitive collection” (Evening Standard) reconfirms the cosmicomics as a crowning literary achievement and makes them available to new generations of reader...

  1. CMS Is Finally Completed

    CERN Multimedia

    2008-01-01

    Yet another step in the completion of the Large Hadron Collider was taken yesterday morning, as the final element of the Compact Muon Solenoid was lowered nearly 100 meters bellow ground. After more than eight years of work at the world's most powerful particle accelerator, scientists hope that they will be able to start initial experiments with the LHC until the end of this year.

  2. LEAR construction completed

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    In July 1982, LEAR construction was completed, the individual systems had been dry-tested. On 16 July, the first 50 MeV (309 MeV/c) protons from Linac 1 were injected and circulated. On 11 October, the first antiprotons from the AA, decelerated in the PS to 609 MeV/c, were injected. Also in 1982, acceleration, deceleration and stochastic cooling were successfully tested. See 9007366 for a more detailed description. See also 8201061, 8204131, 8309026.

  3. SHIVA laser: nearing completion

    International Nuclear Information System (INIS)

    Glaze, J.A.; Godwin, R.O.

    1977-01-01

    Construction of the Shiva laser system is nearing completion. This laser will be operating in fall 1977 and will produce over 20 terawatts of focusable power in a subnanosecond pulse. Fusion experiments will begin early in 1978. It is anticipated that thermonuclear energy release equal to one percent that of the incident light energy will be achieved with sub-millimeter deuterium-tritium targets. From other experiments densities in excess of a thousand times that of liquid are also expected

  4. Mobile weatherstation

    International Nuclear Information System (INIS)

    Hahn, H.; Koutny, P.; Schwabach, H.; Eisenwagner, H.

    1981-01-01

    A mobile weatherstation is described which allows to measure the following parameters: airtemperature, relative humidity, winddirection and windspeed. The station consists of three main units: the central station METEODAT, the multiplexer and the weather measure tower with the sensors. The measured data are displayed in digital form in the central unit and can be printed on a teletype. The power supply is either 220 Volt AC or 24 Volt DC. (author)

  5. SCT Barrel Assembly Complete

    CERN Multimedia

    L. Batchelor

    As reported in the April 2005 issue of the ATLAS eNews, the first of the four Semiconductor Tracker (SCT) barrels, complete with modules and services, arrived safely at CERN in January of 2005. In the months since January, the other three completed barrels arrived as well, and integration of the four barrels into the entire barrel assembly commenced at CERN, in the SR1 building on the ATLAS experimental site, in July. Assembly was completed on schedule in September, with the addition of the innermost layer to the 4-barrel assembly. Work is now underway to seal the barrel thermal enclosure. This is necessary in order to enclose the silicon tracker in a nitrogen atmosphere and provide it with faraday-cage protection, and is a delicate and complicated task: 352 silicon module powertapes, 352 readout-fibre bundles, and over 400 Detector Control System sensors must be carefully sealed into the thermal enclosure bulkhead. The team is currently verifying the integrity of the low mass cooling system, which must be d...

  6. Structural Mobility, Exchange Mobility and Subgroup Consistent Mobility Measurement – US–German Mobility Measurements Revisited

    OpenAIRE

    C. SCHLUTER; D. VAN DE GAER

    2008-01-01

    We formalize the concept of structural mobility and use the framework of subgroup consistent mobility measurement to derive a relative and an absolute measure of mobility that is increasing both in upward structural mobility and exchange mobility. In our empirical illustration, we contribute substantively to the ongoing debate about mobility rankings between the USA and Germany.

  7. Mobile-Only Web Survey Respondents

    NARCIS (Netherlands)

    Lugtig, P.J.|info:eu-repo/dai/nl/304824658; Toepoel, V.|info:eu-repo/dai/nl/304576034; amin, alerk

    2016-01-01

    Web surveys are no longer completed on just a desktop or laptop computer. Respondents increasingly use mobile devices, such as tablets and smartphones to complete web surveys. In this article, we study how respondents in the American Life Panel complete surveys using varying devices. We show that

  8. Solid phase extraction of lead, cadmium and zinc on biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer and their determination in water and food samples.

    Science.gov (United States)

    Tuzen, Mustafa; Sahiner, Samet; Hazer, Baki

    2016-11-01

    A new biodegradable polyhydroxybutyrate diethanol amine (PHB-DEA) polymer was used as adsorbent for the sensitive and selective separation, preconcentration and determination of Pb(II), Cd(II) and Zn(II) by using atomic absorption spectrometry. Diethyl dithiocarbamate was used as chelating reagent. Analytical parameters such as pH, eluent type and its volume, flow rates of sample solution, ligand amount, sample volume were optimized. Effects of some cations, anions and transition metal ions were also investigated. Enrichment factor and relative standard deviation were found to be 100 and 3%, respectively. The limits of detection based on three times standard deviation of blanks (N=21) were found 1.05μgL(-1) for Pb(II), 0.42μgL(-1) for Cd(II) and 0.13μgL(-1) for Zn(II). Limits of quantification (10s, N=21) were found 3.47μgL(-1) for Pb(II), 1.39μgL(-1) for Cd(II) and 0.43μgL(-1) for Zn(II). Accuracy evaluation of the method was confirmed with analyses of certified reference materials (NIST SRM 1515 Apple leaves, IAEA 336 Lichen, GBW 07605 Tea). Optimized method was applied to tap water and food samples after microwave digestion method. Cadmium and lead values in some samples were found higher than legal limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Characterisation of copolymer, poly (hydroxybutyrate-co-hydroxyvalerate) (PHB-co-PHV) produced by Halomonas campisalis (MCM B-1027), its biodegradability and potential application.

    Science.gov (United States)

    Kulkarni, Snehal O; Kanekar, Pradnya P; Jog, Jyoti P; Patil, Prashant A; Nilegaonkar, Smita S; Sarnaik, Seema S; Kshirsagar, Pranav R

    2011-06-01

    Characterisation of polyhydroxyalkanoate (PHA) film produced by haloalkalitolerant Halomonas campisalis (MCM B-1027) in 14L SS fermenter revealed it to have composition of monomer units, HB:HV as 96:4 as analysed by (1)H NMR indicating the PHA as a co-polymer of PHB-co-PHV, molecular weight by gel permeation chromatography as 2.08 × 10(6), melting temperature 166.51°C, tensile strength 18.8 MPa; two relaxations namely beta transition corresponding to the glass rubber transition and alpha transition corresponding to crystalline relaxation by Dynamic Mechanical Thermal analysis and only one relaxation corresponding to MWS interfacial polarisation with activation energy of 129 kJ/mol by broadband dielectric spectroscopy. Optical microscopic studies showed typical Maltese-cross pattern of spherulites. The PHA film was found to be biodegradable by standard ASTM method as well as by soil burial method. The leak proof polymer bags prepared from the film could be used as a packaging material. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Compósitos biodegradáveis de polihidroxibutirato (PHB reforçado com farinha de madeira: propriedades e degradação

    Directory of Open Access Journals (Sweden)

    José Claudio Caraschi

    2002-04-01

    Full Text Available O objetivo deste trabalho foi preparar e avaliar compósitos poliméricos mais compatíveis com o ambiente, ou seja, a obtenção de materiais que sejam biodegradáveis e que apresentem uma maior velocidade de degradação no ambiente. Os compósitos foram preparados a partir do plástico biodegradável polihidroxibutirato (PHB com e sem reforço de farinha de madeira, um resíduo agroindustrial, nas proporções de 10% a 40% em massa, pelo processo de extrusão e moldagem por injeção. As amostras foram avaliadas quanto à estabilidade dimensional, à absorção de água, à resistência química e à degradação natural em cinco diferentes situações ambientais, por diversos períodos de tempo. Os resultados obtidos indicaram que todas as amostras sofreram degradações evidenciadas pela perda de massa e pela descoloração em todas as situações avaliadas, e que a utilização de farinha de madeira resultou em materiais com menor resistência química e maiores taxa de absorção de umidade e velocidade de degradação no ambiente.

  11. Students' Perceptions and Experiences of Mobile Learning

    Science.gov (United States)

    Kim, Daesang; Rueckert, Daniel; Kim, Dong-Joong; Seo, Daeryong

    2013-01-01

    This study focused on how students perceive the use of mobile devices to create a personalized learning experience outside the classroom. Fifty-three students in three graduate TESOL classes participated in this study. All participants completed five class projects designed to help them explore mobile learning experiences with their own mobile…

  12. Complete pancreas traumatic transsection

    Directory of Open Access Journals (Sweden)

    H. Hodžić

    2005-02-01

    Full Text Available This report presents a case of a twenty-year old male with complete pancreas breakdown in the middle of its corpus, which was caused by a strong abdomen compression, with injuries of the spleen, the firstjejunumcurve,mesocolon transversum, left kidney, and appereance of retroperitoneal haemathoma. Surgical treatment started 70 minutes after the injury. The treatment consisted of left pancreatectomy with previous spleenectomy, haemostasis of ruptured mesocolon transversum blood vessels, left kidney exploration, suturing of the firstjejunumcurvelession and double abdomen drainage. Posttraumatic pancreatitis which appeared on the second postoperative day and prolonged drain secretion were successfully solved by conservative treatment.

  13. Complete rerouting protection

    DEFF Research Database (Denmark)

    Stidsen, Thomas K.; Kjærulff, Peter

    2006-01-01

    Protection of communication against network failures is becoming increasingly important and in this paper we present the most capacity efficient protection method possible, the complete rerouting protection method, when requiring that all communication should be restored in case of a single link...... network failure. We present a linear programming model of the protection method and a column generation algorithm. For 6 real world networks, the minimal restoration overbuild network capacity is between 13% and 78%. We further study the importance of the density of the network, derive analytical bounds...

  14. Completion of treatment planning

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    The outline of the lecture included the following topics: entering prescription; plan printout; print and transfer DDR; segment BEV; export to R and V; physician approval; and second check. Considerable attention, analysis and discussion. The summary is as follows: Treatment planning completion is a very responsible process which requires maximum attention; Should be independently checked by the planner, physicist, radiation oncologist and a therapist; Should not be done in a last minute rush; Proper communication between team members; Properly set procedure should prevent propagation of an error by one individual to the treatment: the error should be caught by somebody else. (P.A.)

  15. TestComplete cookbook

    CERN Document Server

    Alpaev, Gennadiy

    2013-01-01

    A practical cookbook, with a perfect package of simple, medium, and advanced recipes targeted at basic programmers as well as expert software testers, who will learn to create, manage, and run automated tests. It is packed with problem-solving recipes that are supported by simple examples.If you are a software tester or a programmer who is involved with testing automation using TestComplete, this book is ideal for you! You will be introduced to the very basics of using the tool, as well as polish any previously gained knowledge in using the tool. If you are already aware of programming basics,

  16. Mobile Termination and Mobile Penetration

    OpenAIRE

    Hurkens, Sjaak; Jeon, Doh-Shin

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two oppos- ing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that fi...

  17. Mobile termination and mobile penetration

    OpenAIRE

    Hurkens, Sjaak

    2009-01-01

    In this paper, we study how access pricing affects network competition when subscription demand is elastic and each network uses non-linear prices and can apply termination-based price discrimination. In the case of a fixed per minute termination charge, we find that a reduction of the termination charge below cost has two opposing effects: it softens competition but helps to internalize network externalities. The former reduces mobile penetration while the latter boosts it. We find that firm...

  18. Mobile Payments : Comparison of Mobile Wallet Concepts

    OpenAIRE

    Narayan, Srikant

    2013-01-01

    Mobile payments are an emerging trend and an alternative to traditional payment methods. Mobile payments involve the usage of the mobile phone to handle credit transfers during purchase of goods and peer to peer money transfers referred to as mobile wallet service, instead of depending on bank cards and cash. In this scenario, while the mobile wallet industry still being in its infancy there exist a few drivers of mobile wallet solutions aiming to create a de-facto standard in the mobile mark...

  19. Complete atrioventricular canal.

    Science.gov (United States)

    Calabrò, Raffaele; Limongelli, Giuseppe

    2006-04-05

    Complete atrioventricular canal (CAVC), also referred to as complete atrioventricular septal defect, is characterised by an ostium primum atrial septal defect, a common atrioventricular valve and a variable deficiency of the ventricular septum inflow. CAVC is an uncommon congenital heart disease, accounting for about 3% of cardiac malformations. Atrioventricular canal occurs in two out of every 10,000 live births. Both sexes are equally affected and a striking association with Down syndrome was found. Depending on the morphology of the superior leaflet of the common atrioventricular valve, 3 types of CAVC have been delineated (type A, B and C, according to Rastelli's classification). CAVC results in a significant interatrial and interventricular systemic-to-pulmonary shunt, thus inducing right ventricular pressure and volume overload and pulmonary hypertension. It becomes symptomatic in infancy due to congestive heart failure and failure to thrive. Diagnosis of CAVC might be suspected from electrocardiographic and chest X-ray findings. Echocardiography confirms it and gives anatomical details. Over time, pulmonary hypertension becomes irreversible, thus precluding the surgical therapy. This is the reason why cardiac catheterisation is not mandatory in infants (less than 6 months) but is indicated in older patients if irreversible pulmonary hypertension is suspected. Medical treatment (digitalis, diuretics, vasodilators) plays a role only as a bridge toward surgery, usually performed between the 3rd and 6th month of life.

  20. Complete atrioventricular canal

    Directory of Open Access Journals (Sweden)

    Limongelli Giuseppe

    2006-04-01

    Full Text Available Abstract Complete atrioventricular canal (CAVC, also referred to as complete atrioventricular septal defect, is characterised by an ostium primum atrial septal defect, a common atrioventricular valve and a variable deficiency of the ventricular septum inflow. CAVC is an uncommon congenital heart disease, accounting for about 3% of cardiac malformations. Atrioventricular canal occurs in two out of every 10,000 live births. Both sexes are equally affected and a striking association with Down syndrome was found. Depending on the morphology of the superior leaflet of the common atrioventricular valve, 3 types of CAVC have been delineated (type A, B and C, according to Rastelli's classification. CAVC results in a significant interatrial and interventricular systemic-to-pulmonary shunt, thus inducing right ventricular pressure and volume overload and pulmonary hypertension. It becomes symptomatic in infancy due to congestive heart failure and failure to thrive. Diagnosis of CAVC might be suspected from electrocardiographic and chest X-ray findings. Echocardiography confirms it and gives anatomical details. Over time, pulmonary hypertension becomes irreversible, thus precluding the surgical therapy. This is the reason why cardiac catheterisation is not mandatory in infants (less than 6 months but is indicated in older patients if irreversible pulmonary hypertension is suspected. Medical treatment (digitalis, diuretics, vasodilators plays a role only as a bridge toward surgery, usually performed between the 3rd and 6th month of life.

  1. Barnett shale completions

    Energy Technology Data Exchange (ETDEWEB)

    Schein, G. [BJ Services, Dallas, TX (United States)

    2006-07-01

    Fractured shales yield oil and gas in various basins across the United States. A map indicating these fractured shale source-reservoir systems in the United States was presented along with the numerous similarities and differences that exist among these systems. Hydrocarbons in the organic rich black shale come from the bacterial decomposition of organic matter, primary thermogenic decomposition of organic matter or secondary thermogenic cracking of oil. The shale may be the reservoir or other horizons may be the primary or secondary reservoir. The reservoir has induced micro fractures or tectonic fractures. This paper described the well completions in the Barnett Shale in north Texas with reference to major players, reservoir properties, mineralogy, fluid sensitivity, previous treatments, design criteria and production examples. The Barnett Shale is an organic, black shale with thickness ranging from 100 to 1000 feet. The total organic carbon (TOC) averages 4.5 per cent. The unit has undergone high rate frac treatments. A review of the vertical wells in the Barnett Shale was presented along with the fracture treatment schedule and technology changes. A discussion of refracturing opportunities and proppant settling and transport revealed that additional proppant increases fluid recovery and enhances production. Compatible scale inhibitors and biocides can be beneficial. Horizontal completions in the Barnett Shale have shown better results than vertical wells, as demonstrated in a production comparison of 3 major horizontal wells in the basin. tabs., figs.

  2. Mobile Marketing

    OpenAIRE

    Luengo Cascudo, Alberto

    2010-01-01

    El principal objetivo de este proyecto es explicar y entender la importancia del Mobile Marketing como nueva herramienta de negocio en el Marketing empresarial. Para ello, el primer objetivo es entender los dos factores que para mí son la clave de su importancia: la evolución del entorno tecnológico y el cambio en los hábitos del consumidor. Debido a la novedad de esta nueva forma de Marketing y al hecho de que está en constante definición, es básico exponer de la forma más cla...

  3. GOGOL: ACADEMIC AND COMPLETE

    Directory of Open Access Journals (Sweden)

    Yuri V. Mann

    2016-12-01

    Full Text Available The ever-increasing international interest to Gogol explains the necessity of publishing a new edition of his works. The present Complete Collection of Gogol’s Works and Letters is an academic edition prepared and published by the A. M. Gorky Institute of World Literature of the Russian Academy of Sciences. It draws on rich experience of studying and publishing Gogol’s heritage in Russia but at the same time questions and underscores Gogol’s relevance for the modern reader and his place in the world culture of our time. It intends to fill in the gaps left by the previous scholarly tradition that failed to recognize some of Gogol’s texts as part of his heritage. Such are, for example, dedicatory descriptions in books and business notes. The present edition accounts not only for the completeness of texts but also for their place within the body of Gogol’s work, as part of his life-long creative process. By counterpoising different editions, it attempts to trace down the dynamics of Gogol’s creative thought while at the same time underscores the autonomy and relevance of each period in his career. For example, this collection publishes two different versions (editions of the same work: while the most recent version has become canonical at the expense of the preceding one, the latter still preserves its meaning and historical relevance. The present edition has the advantage over its predecessors since it has an actual, physical opportunity to erase the gaps, e.g. to publish the hitherto unpublished texts. However, the editors realize that new, hitherto unknown gaps may appear and the present edition will become, in its turn, outdated. At this point, there will be a necessity in the new edition.

  4. Wapice News Mobile Application

    OpenAIRE

    Söylemez, Ilke

    2017-01-01

    Since the mobile phones started to have an increasingly significant role in daily life, the mobile application development also started to be an important area in the software industry. The problem for mobile application developers is to develop a mobile application which supports all the devices and platforms on the market. This issue created a need for cross platform mobile applications. The cross platform mobile development refers to the development of mobile applications that could be use...

  5. Handbook of Mobile Systems Applications and Services

    CERN Document Server

    Kumar, Anup

    2012-01-01

    From fundamental concepts and theories to implementation protocols and cutting-edge applications, the Handbook of Mobile Systems Applications and Services supplies a complete examination of the evolution of mobile services technologies. It examines service-oriented architecture (SOA) and explains why SOA and Service Oriented Computing (SOC) will play key roles in the development of future mobile services. Investigating current service discovery frameworks, the book covers the basics of mobile services and applications developed in various contexts. The first section provides readers with the r

  6. Teach yourself visually complete WordPress

    CERN Document Server

    Majure, Janet

    2013-01-01

    Take your WordPress skills to the next level with these tips, tricks, and tasks Congratulations on getting your blog up and running with WordPress! Now are you ready to take it to the next level? Teach Yourself VISUALLY Complete WordPress takes you beyond the blogging basics with expanded tips, tricks, and techniques with clear, step-by-step instructions accompanied by screen shots. This visual book shows you how to incorporate forums, use RSS, obtain and review analytics, work with tools like Google AdSense, and much more.Shows you how to use mobile tools to edit a

  7. Mobile computing initiatives within pharmacy education.

    Science.gov (United States)

    Cain, Jeff; Bird, Eleanora R; Jones, Mikael

    2008-08-15

    To identify mobile computing initiatives within pharmacy education, including how devices are obtained, supported, and utilized within the curriculum. An 18-item questionnaire was developed and delivered to academic affairs deans (or closest equivalent) of 98 colleges and schools of pharmacy. Fifty-four colleges and schools completed the questionnaire for a 55% completion rate. Thirteen of those schools have implemented mobile computing requirements for students. Twenty schools reported they were likely to formally consider implementing a mobile computing initiative within 5 years. Numerous models of mobile computing initiatives exist in terms of device obtainment, technical support, infrastructure, and utilization within the curriculum. Responders identified flexibility in teaching and learning as the most positive aspect of the initiatives and computer-aided distraction as the most negative, Numerous factors should be taken into consideration when deciding if and how a mobile computing requirement should be implemented.

  8. Advertising on mobile applications

    OpenAIRE

    Sobolevsky, Alexandr

    2015-01-01

    The article analyzes the new method of mobile advertising. Advertising in mobile applications - a subspecies of mobile marketing, where advertising is distributed using mobile phones and smartphones. Ad placement is going on inside of applications and games for smartphones. It has a high potential due to the large number of mobile phone users (over 6.5 billion in 2013).

  9. Mobility Balance Sheet 2009

    International Nuclear Information System (INIS)

    Jorritsma, P.; Derriks, H.; Francke, J.; Gordijn, H.; Groot, W.; Harms, L.; Van der Loop, H.; Peer, S.; Savelberg, F.; Wouters, P.

    2009-06-01

    The Mobility Balance Sheet provides an overview of the state of the art of mobility in the Netherlands. In addition to describing the development of mobility this report also provides explanations for the growth of passenger and freight transport. Moreover, the Mobility Balance Sheet also focuses on a topical theme: the effects of economic crises on mobility. [nl

  10. Mobile video with mobile IPv6

    CERN Document Server

    Minoli, Daniel

    2012-01-01

    Increased reliance on mobile devices and streaming of video content are two of the most recent changes that have led those in the video distribution industry to be concerned about the shifting or erosion of traditional advertising revenues. Infrastructure providers also need to position themselves to take advantage of these trends. Mobile Video with Mobile IPv6provides an overview of the current mobile landscape, then delves specifically into the capabilities and operational details of IPv6. The book also addresses 3G and 4G services, the application of Mobile IPv6 to streaming and other mobil

  11. [Social mobilization].

    Science.gov (United States)

    Bop, C

    1990-04-01

    One of the principal recommendations from Alma Ata and the Bamako Initiative was the need for communities to take responsibility for their own health--a recommendation that still remains unmet and in need of reform in Africa because of the severe economic recession and lack of resources allocated for health care in the region. The mobilization of communities "is the opposite of passivity and submission." People must demystify the notion that health care is the exclusive right of health professionals and should realize that they themselves can bring about changes from the household to the village levels; community mobilization is an integral component of development planning. African societies have developed very centralized structures requiring changes that only their own communities can bring about. Because women remain the principal agents for the family's health they should be informed, about the multiple dimensions leading to good health care to enable them to provide the rest of the family with good nourishment and health care follow-up. Children are a vulnerable and important group that require preventive care. A UNICEF experiment in Senegal is training 10-13 year old school children to visit the parents of 5 children, inform them about vaccinating their children, and to follow-up on their activities with these "adopted families." The need for short and long-term IEC interventions in Africa are a priority and effective strategies must be found to reach the majority of the rural populations where all obstacles such as the lack of infrastructure and illiteracy exist. Mali has used traditional theatre "Koteba" to reach the rural populations on a variety of health issues such as oral rehydration and diarrhea as well as the Rural Audio Library (it used cassettes rather than books) to reach villagers in their own languages. The worst obstacle facing Africa today is the refusal of officials in power to allow people to manage their own lives, of which health is a

  12. Potential of a newly developed high-speed near-infrared (NIR) camera (Compovision) in polymer industrial analyses: monitoring crystallinity and crystal evolution of polylactic acid (PLA) and concentration of PLA in PLA/Poly-(R)-3-hydroxybutyrate (PHB) blends.

    Science.gov (United States)

    Ishikawa, Daitaro; Nishii, Takashi; Mizuno, Fumiaki; Sato, Harumi; Kazarian, Sergei G; Ozaki, Yukihiro

    2013-12-01

    This study was carried out to evaluate a new high-speed hyperspectral near-infrared (NIR) camera named Compovision. Quantitative analyses of the crystallinity and crystal evolution of biodegradable polymer, polylactic acid (PLA), and its concentration in PLA/poly-(R)-3-hydroxybutyrate (PHB) blends were investigated using near-infrared (NIR) imaging. This NIR camera can measure two-dimensional NIR spectral data in the 1000-2350 nm region obtaining images with wide field of view of 150 × 250 mm(2) (approximately 100  000 pixels) at high speeds (in less than 5 s). PLA with differing crystallinities between 0 and 50% blended samples with PHB in ratios of 80/20, 60/40, 40/60, 20/80, and pure films of 100% PLA and PHB were prepared. Compovision was used to collect respective NIR spectra in the 1000-2350 nm region and investigate the crystallinity of PLA and its concentration in the blends. The partial least squares (PLS) regression models for the crystallinity of PLA were developed using absorbance, second derivative, and standard normal variate (SNV) spectra from the most informative region of the spectra, between 1600 and 2000 nm. The predicted results of PLS models achieved using the absorbance and second derivative spectra were fairly good with a root mean square error (RMSE) of less than 6.1% and a determination of coefficient (R(2)) of more than 0.88 for PLS factor 1. The results obtained using the SNV spectra yielded the best prediction with the smallest RMSE of 2.93% and the highest R(2) of 0.976. Moreover, PLS models developed for estimating the concentration of PLA in the blend polymers using SNV spectra gave good predicted results where the RMSE was 4.94% and R(2) was 0.98. The SNV-based models provided the best-predicted results, since it can reduce the effects of the spectral changes induced by the inhomogeneity and the thickness of the samples. Wide area crystal evolution of PLA on a plate where a temperature slope of 70-105 °C had occurred was also

  13. Mobile OS Comparative Study

    OpenAIRE

    Joseph, Jyothy; K, Shinto Kurian

    2013-01-01

    In the fast growing mobile revolutionary era, many operating systems are playing vital role in present market. This study is intending to identify the apt and secure mobile based on mobile operating systems capability and user requirements.

  14. Mobile Inquiry Based Learning

    NARCIS (Netherlands)

    Specht, Marcus

    2012-01-01

    Specht, M. (2012, 8 November). Mobile Inquiry Based Learning. Presentation given at the Workshop "Mobile inquiry-based learning" at the Mobile Learning Day 2012 at the Fernuniversität Hagen, Hagen, Germany.

  15. MOBILITY: A SYSTEMS APPROACH

    Directory of Open Access Journals (Sweden)

    Mykola I. Striuk

    2015-10-01

    Full Text Available A comprehensive study on the problem of mobility in the socio-educational and technical systems was carried out: the evolution of the concept of mobility in scientific sources of XIX–XXI centuries was analyzed and the new sources on the issue of mobility introduced into scientific circulation, the interrelation of the types of mobility in the socio-pedagogical and technical systems are theoretically grounded, an integrative model of mobility in the information society is proposed. The major trends in academic mobility are identified (the transition from student mobility to mobility programs and educational services providers, the new mobility programs (franchising, double/joint degrees, combinations, nostrification etc. are characterized. The new types of mobility providers are reviewed and attention is focused on virtual universities that are now the basis of virtual mobility of students and activities which are based on the use of new ICT in higher education, especially – the Internet and mobile learning environments.

  16. Micro Mobility Marketing

    DEFF Research Database (Denmark)

    Hosbond, Jens Henrik; Skov, Mikael B.

    2008-01-01

    , in our case a medium-sized retail supermarket. Two prototypes based on push and pull marketing strategies are implemented and evaluated. Taking outset in a synthesis of central issues in contemporary research on mobile marketing, we discuss their role in micro mobility marketing to point to similarities......Mobile marketing refers to marketing of services or goods using mobile technology and mobile marketing holds potentially great economical opportunities. Traditionally, mobile marketing has been viewed as mobility in the large taking place virtually anywhere, anytime. Further, research shows...... considerable number of studies on push-based SMS mobile marketing campaigns. This paper explores a related yet different form of mobile marketing namely micro mobility marketing. Micro mobility marketing denotes mobility in the small, meaning that promotion of goods takes place within a circumscribed location...

  17. Mobile Search and Advertising

    OpenAIRE

    Lovitskii, Vladimir; McCaffery, Colin; Thrasher, Michael; Traynor, David; Wright, Peter

    2009-01-01

    Mobile advertising is a rapidly growing sector providing brands and marketing agencies the opportunity to connect with consumers beyond traditional and digital media and instead communicate directly on their mobile phones. Mobile advertising will be intrinsically linked with mobile search, which has transported from the internet to the mobile and is identified as an area of potential growth. The result of mobile searching show that as a general rule such search result exceed 1...

  18. Trends in Mobile Marketing

    OpenAIRE

    Chocholová, Petra

    2010-01-01

    The principal aim of this thesis is to assess the state of the mobile marketing as of the first quarter of 2011 and to discuss various scenarios of the future development. This thesis defines the terms "mobile marketing" and "mobile advertising" and identifies the main players in the industry. It explores the main categories of mobile advertising such as mobile messaging, in-content and mobile internet advertising. Later, it analyzes the latest trends in the industry and describes in detail t...

  19. Research and development project in fiscal 1989 for fundamental technologies for next generation industries. Achievement report on research and development on photoreactive materials (Research on enhancement of functional stability of PHB materials); 1989 nendo hikari hanno zairyo no kenkyu kaihatsu seika hokokusho. PHB zairyo no kino anteisei kojo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1990-03-01

    With an objective of establishing the fundamental technologies related to photo reactive materials that can be used for ultra-high density recording, high-resolution indication, and photoswitches by controlling structures and association status of molecules by using actions of light, research and development has been performed. This paper summarizes the achievements in fiscal 1989. In the research of synthesis and evaluation of PHB materials, a possibility was verified to form holes at temperatures higher than the liquid nitrogen temperature on all the materials in which six kinds of ionic porphin derivatives were dispersed into polyvinyl alcohol. Stability of holes in the tetra-alkyl pyridinium porhpn/polymer system was evaluated, the hole half-width was measured accurately by using ring die laser, and the hole forming characteristics were evaluated by means of high-power density and brief laser light irradiation. In search of new guests, a two-photon absorption spectrum measuring instrument was assembled to measure samples having zinc tetra-phenylporphyrin derivative as the guest. In addition, hole formation was discovered in samples having indomethylene based coloring matter as the guest. (NEDO)

  20. Modifications induced by swift heavy ions in poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly(ε-caprolactone) (PCL) films. Part 1. Thermal behaviour and molecular mass modifications

    International Nuclear Information System (INIS)

    Rouxhet, L.; Legras, R.

    2000-01-01

    Modifications induced by different energetic heavy ions in poly(ε-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by the differential scanning calorimetry (DSC) and steric exclusion chromatography (SEC). A certain dose of damages, depending mainly on the charge and mass of the ion and on the intensity of irradiation, has to be overcome in order to detect any effect on PHB/HV. Actually, at a given intensity of irradiation, superior to 10 10 ions/cm 2 , the level of damage intensity increased with the increase in charge and mass of the ion. Moreover, according to the SEC results, there seems to be a critical mass and/or charge threshold above which the dominant type of damages changes. As a matter of fact, high-density irradiation with Ar 9+ and Kr 15+ resulted mainly in chain scission whereas cross-linking was dominant when irradiating the polymer with Xe 24+ and Pb 56+ . The irradiation of PCL in the conditions studied did not modify significantly the values of the melting point, the crystallisation temperature and the molecular masses of the system studied. The main effect of the irradiation detected by the DSC is the cross-linking of the polymer chains

  1. Concatenated image completion via tensor augmentation and completion

    OpenAIRE

    Bengua, Johann A.; Tuan, Hoang D.; Phien, Ho N.; Do, Minh N.

    2016-01-01

    This paper proposes a novel framework called concatenated image completion via tensor augmentation and completion (ICTAC), which recovers missing entries of color images with high accuracy. Typical images are second- or third-order tensors (2D/3D) depending if they are grayscale or color, hence tensor completion algorithms are ideal for their recovery. The proposed framework performs image completion by concatenating copies of a single image that has missing entries into a third-order tensor,...

  2. Combine mobile monitoring conception

    International Nuclear Information System (INIS)

    Stolyarevsky, I.; Ivanov, J.A.; Arkhipov, N.

    2001-01-01

    This work is a document of joint final report of the collaboration between CHESCIR and JAERI on the Subject-1 'A Study on the Measurements and Evaluation of External Dose after Nuclear Accident' of JCP-1 project 'A Study on the Assessment, Analysis and Verification of the Consequences of the accident at Chernobyl' in the framework of the Agreement between JAERI and RIA 'PRIPYAT' (since 1994, CHESCIR) for 1995-1999. The most substantial part of the collaboration was research with using mobile gamma survey system, that was developed in JAERI and equipped with GIS - navigator that was developed in CHESCIR. During collaboration the carbone survey on the network of roads covered most are contaminated by Chernobyl fallout in Ukraine, Belorussia and Russia. Routes of carbone survey, carried out by CHESCIR team together with JAERI and alone for the last 5 years are shown in a non-complete map. Length of all routes taking into considers double raids is longer than 18,000 km. Experimental and methodological experience of mobile monitoring that collected by both sides allows to make considerations and conclusions, which are available in this final report. (J.P.N.)

  3. Combine mobile monitoring conception

    Energy Technology Data Exchange (ETDEWEB)

    Stolyarevsky, I.; Ivanov, J.A.; Arkhipov, N. [Chernobyl Scientific and Technical Center for International Researches (CHESCIR) (Ukraine)] [and others

    2001-03-01

    This work is a document of joint final report of the collaboration between CHESCIR and JAERI on the Subject-1 'A Study on the Measurements and Evaluation of External Dose after Nuclear Accident' of JCP-1 project 'A Study on the Assessment, Analysis and Verification of the Consequences of the accident at Chernobyl' in the framework of the Agreement between JAERI and RIA 'PRIPYAT' (since 1994, CHESCIR) for 1995-1999. The most substantial part of the collaboration was research with using mobile gamma survey system, that was developed in JAERI and equipped with GIS - navigator that was developed in CHESCIR. During collaboration the carbone survey on the network of roads covered most are contaminated by Chernobyl fallout in Ukraine, Belorussia and Russia. Routes of carbone survey, carried out by CHESCIR team together with JAERI and alone for the last 5 years are shown in a non-complete map. Length of all routes taking into considers double raids is longer than 18,000 km. Experimental and methodological experience of mobile monitoring that collected by both sides allows to make considerations and conclusions, which are available in this final report. (J.P.N.)

  4. Mobile Operating Systems

    OpenAIRE

    Vipin Kamboj; Hitesh Gupta

    2012-01-01

    Mobile phones are used by every people in today’s life. We use mobile phones without knowing the different factors that a mobile used including its technology, operating system, CPU ,RAM etc. Many types of operating system are used by different mobile. Every operating system has their advantage

  5. Mobile Africa : an introduction

    NARCIS (Netherlands)

    Bruijn, de M.E.; Dijk, van R.A.; Foeken, D.W.J.

    2001-01-01

    The case studies in this book on mobility in sub-Saharan Africa critically discuss dichotomous interpretations of mobility and reject the idea that migration indicates a breakdown in society. They adopt the approach that sedentary and mobile worlds converge and that mobility is part of the

  6. Mobile nuclear reactor containment vessel

    International Nuclear Information System (INIS)

    Thompson, R.E.; Spurrier, F.R.; Jones, A.R.

    1978-01-01

    A containment vessel for use in mobile nuclear reactor installations is described. The containment vessel completely surrounds the entire primary system, and is located as close to the reactor primary system components as is possible in order to minimize weight. In addition to being designed to withstand a specified internal pressure, the containment vessel is also designed to maintain integrity as a containment vessel in case of a possible collision accident

  7. Evolution of Mobile Applications

    Directory of Open Access Journals (Sweden)

    Phongtraychack Anachack

    2018-01-01

    Full Text Available Currently, we can see the rapid evolution of mobile technology, which involves mobile communication, mobile hardware, and mobile software. Features of mobile phones largely depend on software. In contemporary information and communication age [1–4], mobile application is one of the most concerned and rapidly developing areas. At the same time, the development of mobile application undergoes great changes with the introduction of new software, service platforms and software development kits (SDK. These changes lead to appearance of many new service platforms such as Google with Android and Apple with iOS. This article presents the information about the evolution of mobile application, gives some statistical data on the past and present situation, demonstrates how individual users of mobile devices can benefit, and shows how mobile applications affect society from the ethical perspective.

  8. p-topological Cauchy completions

    Directory of Open Access Journals (Sweden)

    J. Wig

    1999-01-01

    Full Text Available The duality between “regular” and “topological” as convergence space properties extends in a natural way to the more general properties “p-regular” and “p-topological.” Since earlier papers have investigated regular, p-regular, and topological Cauchy completions, we hereby initiate a study of p-topological Cauchy completions. A p-topological Cauchy space has a p-topological completion if and only if it is “cushioned,” meaning that each equivalence class of nonconvergent Cauchy filters contains a smallest filter. For a Cauchy space allowing a p-topological completion, it is shown that a certain class of Reed completions preserve the p-topological property, including the Wyler and Kowalsky completions, which are, respectively, the finest and the coarsest p-topological completions. However, not all p-topological completions are Reed completions. Several extension theorems for p-topological completions are obtained. The most interesting of these states that any Cauchy-continuous map between Cauchy spaces allowing p-topological and p′-topological completions, respectively, can always be extended to a θ-continuous map between any p-topological completion of the first space and any p′-topological completion of the second.

  9. MOBILITY: A SYSTEMS APPROACH

    OpenAIRE

    Mykola I. Striuk; Serhiy O. Semerikov; Andrii M. Striuk

    2015-01-01

    A comprehensive study on the problem of mobility in the socio-educational and technical systems was carried out: the evolution of the concept of mobility in scientific sources of XIX–XXI centuries was analyzed and the new sources on the issue of mobility introduced into scientific circulation, the interrelation of the types of mobility in the socio-pedagogical and technical systems are theoretically grounded, an integrative model of mobility in the information society is proposed. The major t...

  10. Mobile platform security

    CERN Document Server

    Asokan, N; Dmitrienko, Alexandra

    2013-01-01

    Recently, mobile security has garnered considerable interest in both the research community and industry due to the popularity of smartphones. The current smartphone platforms are open systems that allow application development, also for malicious parties. To protect the mobile device, its user, and other mobile ecosystem stakeholders such as network operators, application execution is controlled by a platform security architecture. This book explores how such mobile platform security architectures work. We present a generic model for mobile platform security architectures: the model illustrat

  11. Structure completion for facade layouts

    KAUST Repository

    Fan, Lubin; Musialski, Przemyslaw; Liu, Ligang; Wonka, Peter

    2014-01-01

    completion with large missing parts is an ill-posed problem. Therefore, we combine two sources of information to derive our solution: the observed shapes and a database of complete layouts. The problem is also very difficult, because shape positions

  12. Conceptual spatial representations for indoor mobile robots

    OpenAIRE

    Zender, Henrik; Mozos, Oscar Martinez; Jensfelt, Patric; Kruijff, Geert-Jan M.; Wolfram, Burgard

    2008-01-01

    We present an approach for creating conceptual representations of human-made indoor environments using mobile robots. The concepts refer to spatial and functional properties of typical indoor environments. Following findings in cognitive psychology, our model is composed of layers representing maps at different levels of abstraction. The complete system is integrated in a mobile robot endowed with laser and vision sensors for place and object recognition. The system also incorporate...

  13. Abrechnung mobiler Dienste im Mobile-Payment-Referenzmodell

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  14. Charging of mobile services by mobile payment reference model

    OpenAIRE

    Pousttchi, Key; Wiedemann, Dietmar Georg

    2005-01-01

    The purpose of the paper is to analyze mobile payments in the mobile commerce scenario. Therefore, we first classify the mobile payment in the mobile commerce scenario by explaining general offer models, charging concepts, and intermediaries. Second, we describe the mobile payment reference model, especially, the mobile payment reference organization model and different mobile payment standard types. Finally, we conclude our findings.

  15. The Role of Participatory Design in Mobile Application Development

    Science.gov (United States)

    Hamzah, Almed

    2018-03-01

    Mobile devices are used by people worldwide. It becomes a common equipment to complete a day-to-day activity. Inside the devices, there are numerous mobile applications that have been built for various needs. Some of these are quite successful while the other are not. The development of successful mobile application faces several challenges. In this research, we want to explore the use of participatory design method in mobile application development. Particularly, the aim of the study is to answer the question whether participatory design method has a place in the realm of mobile application development. We established two sessions of workshop to accommodate the participant to take part in the development process of mobile application. The result shows that participatory design method can determine how the user will deal with the limitations of mobile devices. It helps user to create a particular form of interaction that meets mobile devices characteristics.

  16. Head First Mobile Web

    CERN Document Server

    Gardner, Lyza; Grigsby, Jason

    2011-01-01

    Despite the huge number of mobile devices and apps in use today, your business still needs a website. You just need it to be mobile. Head First Mobile Web walks you through the process of making a conventional website work on a variety smartphones and tablets. Put your JavaScript, CSS media query, and HTML5 skills to work-then optimize your site to perform its best in the demanding mobile market. Along the way, you'll discover how to adapt your business strategy to target specific devices. Navigate the increasingly complex mobile landscapeTake both technical and strategic approaches to mobile

  17. Mobile Portal Implementation Strategy

    DEFF Research Database (Denmark)

    Gao, Ping; Damsgaard, Jan

    2005-01-01

    Mobile portal plays an important role in mobile commerce market. Current literature focuses on static analysis on the value chain of mobile portals. This article provides a dynamic perspective on mobile portal strategy. Drawing upon network economics, we describe mobile portal implementation...... as a fourphase process. In different phase, a portal provider has various challenges to overcome and adopt diverse strategies, and correspondingly the regulator has different foci. The conceptual framework proposed in this article offers a basis for further analyses on the market dynamics of mobile commerce......, and can be generalized to studying other networked technologies...

  18. Dynamic Rule Encryption for Mobile Payment

    Directory of Open Access Journals (Sweden)

    Emir Husni

    2017-01-01

    Full Text Available The trend of financial transactions by using a mobile phone or mobile payment increases. By using the mobile payment service, users can save money on mobile phone (handset and separate from the pulse. For protecting users, mobile payment service providers must complete the mobile payment service with the transaction security. One way to provide transaction security is to utilize a secure mobile payment application. This research provides a safety feature used for an Android-based mobile payment application. This security feature is making encryption rules dynamically named Dynamic Rule Encryption (DRE. DRE has the ability to protect data by means of encrypting data with dynamic rules, and DRE also has a token function for an authentication. DRE token raised with dynamic time-based rules. Here, the time is used as a reference with the order of the day in the year (day of the year. The processes of the DRE’s encryption, decryption, and the DRE’s functionality as the token are discussed in this paper. Here, the Hamming distance metric is employed for having maximum differences between plaintext and ciphertext.

  19. Network constellations for mobile payments - Influence of the leading partner on NFC-based mobile digital wallets

    OpenAIRE

    Sánchez Garvín, Mario

    2011-01-01

    The mobile payments industry, which is currently at an early stage of development, is taking the direction to be established mainly as an NFC-based industry, and, moreover, led by the mobile digital wallets setting. A mobile digital wallet is a complete payment app for your NFC-enabled mobile phone that enables consumers to pay at stores at the point of sale with a mobile phone. The digital wallet, which is associated with a credit card, integrates all payment-related services like the manage...

  20. Completeness theorems in transport theory

    International Nuclear Information System (INIS)

    Zweifel, P.F.

    1984-01-01

    Ever since K. M.; Case's famous 1960 paper, transport theorists have been studying the questions of full- and half-range completeness for various transport type equations. The purpose of this note is to try to define exactly what is meant by completeness as it is needed, and used, in solving transport equations and to discuss some of the various techniques which have been, or might be, used to verify completeness. Attention is restricted to the question of full-range completeness. As a paradigm the generalized form of the transport equation first introduced by Beals is adopted

  1. Predictability of Mobile Phone Associations

    DEFF Research Database (Denmark)

    Jensen, Bjørn Sand; Larsen, Jan; Hansen, Lars Kai

    2010-01-01

    Prediction and understanding of human behavior is of high importance in many modern applications and research areas ranging from context-aware services, wireless resource allocation to social sciences. In this study we collect a novel dataset using standard mobile phones and analyze how the predi...... representation, and general behavior. This is of vital interest in the development of context-aware services which rely on forecasting based on mobile phone sensors.......Prediction and understanding of human behavior is of high importance in many modern applications and research areas ranging from context-aware services, wireless resource allocation to social sciences. In this study we collect a novel dataset using standard mobile phones and analyze how...... the predictability of mobile sensors, acting as proxies for humans, change with time scale and sensor type such as GSM and WLAN. Applying recent information theoretic methods, it is demonstrated that an upper bound on predictability is relatively high for all sensors given the complete history (typically above 90...

  2. Ion mobility sensor system

    Science.gov (United States)

    Xu, Jun; Watson, David B.; Whitten, William B.

    2013-01-22

    An ion mobility sensor system including an ion mobility spectrometer and a differential mobility spectrometer coupled to the ion mobility spectrometer. The ion mobility spectrometer has a first chamber having first end and a second end extending along a first direction, and a first electrode system that generates a constant electric field parallel to the first direction. The differential mobility spectrometer includes a second chamber having a third end and a fourth end configured such that a fluid may flow in a second direction from the third end to the fourth end, and a second electrode system that generates an asymmetric electric field within an interior of the second chamber. Additionally, the ion mobility spectrometer and the differential mobility spectrometer form an interface region. Also, the first end and the third end are positioned facing one another so that the constant electric field enters the third end and overlaps the fluid flowing in the second direction.

  3. Seasonality, mobility, and livability.

    Science.gov (United States)

    2012-01-31

    Signature project 4a, Seasonality, Mobility, and Livability investigated the effects of weather, season, built environment, community amenities, attitudes, and demographics on mobility and quality of life (QOL). A four season panel survey exami...

  4. Mobile IP: Security & application

    NARCIS (Netherlands)

    Tuquerres, G.; Salvador, M.R.; Sprenkels, Ron

    1999-01-01

    As required in the TGS Mobile IP Advanced Module, this paper presents a survey of common security threats which mobile IP networks are exposed to as well as some proposed solutions to deal with such threats.

  5. Mobile Phones on Campus

    Institute of Scientific and Technical Information of China (English)

    朴春宝

    2007-01-01

    After entering the 21st century, more and more people have mobile phones in China. At the end of 2002, there were 20 million mobile phone users. By the year 2005 the number has reached up to 30 million.

  6. Mobile Internet Protocol Analysis

    National Research Council Canada - National Science Library

    Brachfeld, Lawrence

    1999-01-01

    ...) and User Datagram Protocol (UDP). Mobile IP allows mobile computers to send and receive packets addressed with their home network IP address, regardless of the IP address of their current point of attachment on the Internet...

  7. Mobile Informal Learning

    NARCIS (Netherlands)

    Glahn, Christian; Börner, Dirk

    2010-01-01

    Glahn, C., & Börner, D. (2009). Mobile Informal Learning. Presented at Mobile Learning in Context Symposium at the Open University of the Netherlands. September, 11, 2009, Heerlen, The Netherlands: Open University of the Netherlands.

  8. The Rise of Mobile Technology on the Financial Sector in Zimbabwe

    OpenAIRE

    Paul Mupfiga; Tafadzwa Padare

    2017-01-01

    The emergence of technology has revolted the way that the financial industry operates and the increasing use of mobile gadgets has changed the banking system from the traditional brick and mortar building to a virtual system. The sudden rise in use and innovation of smart mobile phones, mobile personal computers, tablets and various other mobile electronic gadgets has resulted in the rise of mobile financial products. Rapid quickening innovative headways are making completely new business sug...

  9. Fixed mobile convergence handbook

    CERN Document Server

    Ahson, Syed A

    2010-01-01

    From basic concepts to future directions, this handbook provides technical information on all aspects of fixed-mobile convergence (FMC). The book examines such topics as integrated management architecture, business trends and strategic implications for service providers, personal area networks, mobile controlled handover methods, SIP-based session mobility, and supervisory and notification aggregator service. Case studies are used to illustrate technical and systematic implementation of unified and rationalized internet access by fixed-mobile network convergence. The text examines the technolo

  10. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  11. Mobile Marketing in Japan

    OpenAIRE

    Noah H. N. Lynn; Paul D. Berger

    2014-01-01

    In this paper we describe the state of mobile marketing in Japan. We consider the various aspects of mobile marketing in Japan and what has led to the overwhelming adoption by Japanese youth, and to a degree Japanese society as a whole, of social media and associated activities. This growth of mobile marketing has dramatic, positive implications for marketing, in general, as well as for the sale of selected product classes. We also consider markers for suggesting what the future of mobile mar...

  12. Latino College Completion: New York

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  13. Latino College Completion: United States

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  14. Latino College Completion: South Dakota

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  15. Latino College Completion: North Dakota

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  16. Latino College Completion: New Mexico

    Science.gov (United States)

    Excelencia in Education (NJ1), 2012

    2012-01-01

    In 2009, Excelencia in Education launched the Ensuring America's Future initiative to inform, organize, and engage leaders in a tactical plan to increase Latino college completion. An executive summary of Latino College Completion in 50 states synthesizes information on 50 state factsheets and builds on the national benchmarking guide. Each…

  17. Structure completion for facade layouts

    KAUST Repository

    Fan, Lubin

    2014-11-18

    (Figure Presented) We present a method to complete missing structures in facade layouts. Starting from an abstraction of the partially observed layout as a set of shapes, we can propose one or multiple possible completed layouts. Structure completion with large missing parts is an ill-posed problem. Therefore, we combine two sources of information to derive our solution: the observed shapes and a database of complete layouts. The problem is also very difficult, because shape positions and attributes have to be estimated jointly. Our proposed solution is to break the problem into two components: a statistical model to evaluate layouts and a planning algorithm to generate candidate layouts. This ensures that the completed result is consistent with the observation and the layouts in the database.

  18. Mobile energy sharing futures

    DEFF Research Database (Denmark)

    Worgan, Paul; Knibbe, Jarrod; Plasencia, Diego Martinez

    2016-01-01

    We foresee a future where energy in our mobile devices can be shared and redistributed to suit our current task needs. Many of us are beginning to carry multiple mobile devices and we seek to re-evaluate the traditional view of a mobile device as only accepting energy. In our vision, we can...... sharing futures....

  19. CONCEPT OF MOBILE LEARNING

    Directory of Open Access Journals (Sweden)

    Г О Дуйсеева

    2016-12-01

    Full Text Available This article deals with the definition and the description of mobile learning. Ten years’ experience of the latest mobile technologies use and devices in educational process abroad is analyzed. Prospects and the possibilities of application of these technologies are considered. The basic concepts and development of mobile learning which proposed by scientists for the last years have been given.

  20. Marketing mobile imaging services.

    Science.gov (United States)

    McCue, P

    1987-09-01

    Competition in the mobile imaging arena has put radiologists, radiology directors, and other health care professionals in the unfamiliar position of being marketing agents for their services. Mobile imaging is being promoted through consumer advertising as well as through the traditional route of physician referral. This article offers some of the marketing lessons being learned in the mobile arena.

  1. Mobile Student Information System

    Science.gov (United States)

    Asif, Muhammad; Krogstie, John

    2011-01-01

    Purpose: A mobile student information system (MSIS) based on mobile computing and context-aware application concepts can provide more user-centric information services to students. The purpose of this paper is to describe a system for providing relevant information to students on a mobile platform. Design/methodology/approach: The research…

  2. Complexity of Products of Some Complete and Complete Bipartite Graphs

    Directory of Open Access Journals (Sweden)

    S. N. Daoud

    2013-01-01

    Full Text Available The number of spanning trees in graphs (networks is an important invariant; it is also an important measure of reliability of a network. In this paper, we derive simple formulas of the complexity, number of spanning trees, of products of some complete and complete bipartite graphs such as cartesian product, normal product, composition product, tensor product, and symmetric product, using linear algebra and matrix analysis techniques.

  3. Mobile robot for hazardous environments

    International Nuclear Information System (INIS)

    Bains, N.

    1995-01-01

    This paper describes the architecture and potential applications of the autonomous robot for a known environment (ARK). The ARK project has developed an autonomous mobile robot that can move around by itself in a complicated nuclear environment utilizing a number of sensors for navigation. The primary sensor system is computer vision. The ARK has the intelligence to determine its position utilizing open-quotes natural landmarks,close quotes such as ordinary building features at any point along its path. It is this feature that gives ARK its uniqueness to operate in an industrial type of environment. The prime motivation to develop ARK was the potential application of mobile robots in radioactive areas within nuclear generating stations and for nuclear waste sites. The project budget is $9 million over 4 yr and will be completed in October 1995

  4. Mobile phone based ELISA (MELISA).

    Science.gov (United States)

    Zhdanov, Arsenii; Keefe, Jordan; Franco-Waite, Luis; Konnaiyan, Karthik Raj; Pyayt, Anna

    2018-04-30

    Enzyme-linked immunosorbent assay (ELISA) is one of the most important technologies for biochemical analysis critical for diagnosis and monitoring of many diseases. Traditional systems for ELISA incubation and reading are expensive and bulky, thus cannot be used at point-of-care or in the field. Here, we propose and demonstrate a new miniature mobile phone based system for ELISA (MELISA). This system can be used to complete all steps of the assay, including incubation and reading. It weighs just 1 pound, can be fabricated at low cost, portable, and can transfer test results via mobile phone. We successfully demonstrated how MELISA can be calibrated for accurate measurements of progesterone and demonstrated successful measurements with the calibrated system. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Distributed mobility management - framework & analysis

    NARCIS (Netherlands)

    Liebsch, M.; Seite, P.; Karagiannis, Georgios

    2013-01-01

    Mobile operators consider the distribution of mobility anchors to enable offloading some traffic from their core network. The Distributed Mobility Management (DMM) Working Group is investigating the impact of decentralized mobility management to existing protocol solutions, while taking into account

  6. Trend of Complete Hydatidiform Mole

    Directory of Open Access Journals (Sweden)

    K Thapa

    2010-03-01

    Full Text Available INTRODUCTION: Complete Hydatidiform mole is one of the most frequent abnormal pregnancies. This review studies the trend of complete mole in Paropakar Maternity and Women's hospital and clinical ability to detect it. METHODS: This is a retrospective study of 504 cases of complete hydatidiform mole recorded at Paropakar maternity and women's hospital, Kathmandu, during 2058-2065 B.S. Medical records were reviewed and incidence, clinical presentation and method of diagnosis were studied. RESULTS: During the study period, there were 13,9117 births and 504 complete moles, 12 partial moles, 48 persistent gestational tumours, six choriocarcinoma and four invasive moles recorded in the hospital. The incidence of complete mole was one per 276 births. It was prevalent among women younger than 29 years (80% and among the primigravidae (36.7%. More than 90% women presented in the first half of their pregnancy and vaginal bleeding was the main complaint (68.3%. Suction evacuation, dilation and evacuation followed by sharp curettage and abdominal hysterectomy were performed in 80.6%, 17.6% and 1.2% of the women respectively. Persistent mole and choriocarcinoma developed in 9.5% and 0.4% respectively. CONCLUSIONS: Complete mole has the highest incidence. It affects mostly younger women and presents with vaginal bleeding most of the time, usually in the first half of their pregnancy. Keywords: complete hydatidiform mole, gestational trophoblastic disease, persistent gestational tumours.

  7. Understanding pastoral mobility

    DEFF Research Database (Denmark)

    Adriansen, Hanne Kirstine

    2008-01-01

    Based on a case study from Sahelian Senegal, this paper analyses how various actors perceive the importance of pastoral mobility and presents issues of importance for understanding the use of mobility among Fulani of Ferlo. One knowledge system is a scientific one, the 'new rangeland paradigm...... territory, which they consider their place, but are unwilling to employ large-scale mobility themselves. Mobility is not of importance for their ethnic identity and some use paid herders to care for their livestock. By looking at both knowledge systems, we achieve a better understanding of pastoral mobility...

  8. Mobile Virtual Private Networking

    Science.gov (United States)

    Pulkkis, Göran; Grahn, Kaj; Mårtens, Mathias; Mattsson, Jonny

    Mobile Virtual Private Networking (VPN) solutions based on the Internet Security Protocol (IPSec), Transport Layer Security/Secure Socket Layer (SSL/TLS), Secure Shell (SSH), 3G/GPRS cellular networks, Mobile IP, and the presently experimental Host Identity Protocol (HIP) are described, compared and evaluated. Mobile VPN solutions based on HIP are recommended for future networking because of superior processing efficiency and network capacity demand features. Mobile VPN implementation issues associated with the IP protocol versions IPv4 and IPv6 are also evaluated. Mobile VPN implementation experiences are presented and discussed.

  9. European mobility cultures

    DEFF Research Database (Denmark)

    Haustein, Sonja; Nielsen, Thomas A. Sick

    2016-01-01

    More targeted European policies promoting green travel patterns require better knowledge on differing mobility cultures across European regions. As a basis for this, we clustered the EU population into eight mobility styles based on Eurobarometer data. The mobility styles - including, for example...... positions on the path towards sustainable mobility and therefore different requirements towards European platforms and support measures, e.g. for 'Sustainable Urban Mobility Plans'. The country clusters can provide a starting point for future communication and targeting of European efforts in sustainable...

  10. Cost-effective resource allocation in C-RAN with mobile cloud

    OpenAIRE

    Wang, Kezhi; Yang, Kun; Wang, Xinhou; Magurawalage, Chathura Sarathchandra

    2016-01-01

    Taking full advantages of two cloud-based techniques, i.e., cloud radio access network (C-RAN) and mobile cloud computing (MCC), mobile operators will be able to provide the good service to the mobile user as well as increasing their revenue. This paper aims to minimize the mobile operator's cost while at the same time, meet the task time constraints of the mobile users. In particular, we assume that the mobile cloud first completes the tasks for the mobile user and then transmits the results...

  11. Engaging with mobile methods

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2014-01-01

    This chapter showcases how mobile methods are more than calibrated techniques awaiting application by tourism researchers, but productive in the enactment of the mobile (Law and Urry, 2004). Drawing upon recent findings deriving from a PhD course on mobility and mobile methods it reveals...... the conceptual ambiguousness of the term ‘mobile methods’. In order to explore this ambiguousness the chapter provides a number of examples deriving from tourism research, to explore how mobile methods are always entangled in ideologies, predispositions, conventions and practice-realities. Accordingly......, the engagements with methods are acknowledged to be always political and contextual, reminding us to avoid essentialist discussions regarding research methods. Finally, the chapter draws on recent fieldwork to extend developments in mobilities-oriented tourism research, by employing auto-ethnography to call...

  12. Mobile systems development

    DEFF Research Database (Denmark)

    Pedersen, Ole; Kristiansen, Martin Lund; Kammersgaard, Marc N.

    2007-01-01

    in XP. In general, we find XP well-suited for mobile systems development projects. However, based on our experiences and an analytical comparison we propose the following modifications to XP: Make an essential design to avoid the worst time waste during refactoring. For faster development, reuse code......Development of mobile software is Surrounded by much uncertainty. Immature software platforms on mobile clients, a highly competitive market calling for innovation, efficiency and effectiveness in the development life cycle, and lacking end-user adoption are just some of the realities facing...... development teams in the mobile software industry. By taking a process view on development of mobile systems we seek to explore the strengths and limitations of eXtreme Programming (XP) in the context of mobile software development. Following an experimental approach a mobile systems development project...

  13. Large Hadron Collider nears completion

    CERN Multimedia

    2008-01-01

    Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.

  14. Complete Blood Count (For Parents)

    Science.gov (United States)

    ... Kids Deal With Injections and Blood Tests Blood Culture Anemia Blood Test: Basic Metabolic Panel (BMP) Blood Test: Hemoglobin Basic Blood Chemistry Tests Word! Complete Blood Count (CBC) Medical Tests and Procedures ( ...

  15. Monitoring Completed Navigation Projects Program

    National Research Council Canada - National Science Library

    Bottin, Jr., Robert R

    2001-01-01

    ... (MCNP) Program. The program was formerly known as the Monitoring Completed Coastal Projects Program, but was modified in the late 1990s to include all navigation projects, inland as well as coastal...

  16. Cyberbotics Ltd. Webots™: Professional Mobile Robot Simulation

    Directory of Open Access Journals (Sweden)

    Olivier Michel

    2004-03-01

    Full Text Available Cyberbotics Ltd. develops Webots™, a mobile robotics simulation software that provides you with a rapid prototyping environment for modelling, programming and simulating mobile robots. The provided robot libraries enable you to transfer your control programs to several commercially available real mobile robots. Webots™ lets you define and modify a complete mobile robotics setup, even several different robots sharing the same environment. For each object, you can define a number of properties, such as shape, color, texture, mass, friction, etc. You can equip each robot with a large number of available sensors and actuators. You can program these robots using your favorite development environment, simulate them and optionally transfer the resulting programs onto your real robots. Webots™ has been developed in collaboration with the Swiss Federal Institute of Technology in Lausanne, thoroughly tested, well documented and continuously maintained for over 7 years. It is now the main commercial product available from Cyberbotics Ltd.

  17. WebotsTM: Professional Mobile Robot Simulation

    Directory of Open Access Journals (Sweden)

    Olivier Michel

    2008-11-01

    Full Text Available Cyberbotics Ltd. develops WebotsTM, a mobile robotics simulation software that provides you with a rapid prototyping environment for modelling, programming and simulating mobile robots. The provided robot libraries enable you to transfer your control programs to several commercially available real mobile robots. WebotsTM lets you define and modify a complete mobile robotics setup, even several different robots sharing the same environment. For each object, you can define a number of properties, such as shape, color, texture, mass, friction, etc. You can equip each robot with a large number of available sensors and actuators. You can program these robots using your favorite development environment, simulate them and optionally transfer the resulting programs onto your real robots. WebotsTM has been developed in collaboration with the Swiss Federal Institute of Technology in Lausanne, thoroughly tested, well documented and continuously maintained for over 7 years. It is now the main commercial product available from Cyberbotics Ltd.

  18. Connecting Mobile Users Through Mobile Social Networks

    Directory of Open Access Journals (Sweden)

    Faisal Alkhateeb

    2012-10-01

    Full Text Available Nowadays, social networks become popular with the emerging of web-based social networking services. Recently, several mobile services are developed to connect users to their favourite social networks such as Facebook, Twitter, Flickr, etc. However, these services depends upon the existing web-based social networks. In this paper, we present a mobile service for joining groups across communities. The originality of the work is that the framework of the service allows creating and joining social networks that are self-contained for mobile company servers. The service consists of several sub-services such as users invitation, group finding and others. Users, regardless of their disability, can use the service and its sub-services without the need to create their own accounts on social web sites and thus their own groups. We also propose a privacy control policy for mobile social networks.

  19. Complete colonic duplication in children.

    Science.gov (United States)

    Khaleghnejad Tabari, Ahmad; Mirshemirani, Alireza; Khaleghnejad Tabari, Nasibeh

    2012-01-01

    Complete colonic duplication is a very rare congenital anomaly that may have different presentations according to its location and size. Complete colonic duplication can occur in 15% of gastrointestinal duplication. We report two cases of complete colonic duplications, and their characteristics. We present two patients with complete colonic duplication with different types and presentations. Case 1: A 2- year old boy presented to the clinic with abdominal protrusion, difficulty to defecate, chronic constipation and mucosal prolaps covered bulging (rectocele) since he was 6 months old. The patient had palpable pelvic mass with doughy consistency. Rectal exam confirmed perirectal mass with soft consistency. The patient underwent a surgical operation that had total tubular colorectal duplication with one blind end and was treated with simple fenestration of distal end, and was discharged without complication. After two years follow up, he had normal defecation and good weight gain. Case 2: A 2 -day old infant was referred with imperforate anus and complete duplication of recto-sigmoid colon, diphallus, double bladder, and hypospadiasis. After clinical and paraclinical investigations, he underwent operations in several stages in different periods, and was discharged without complications. After four years follow up, he led a normal life. The patients with complete duplication have to be examined carefully because of the high incidence of other systemic anomalies. Treatment includes simple resection of distal common wall, fenestration, and repair other associated anomalies.

  20. Mobile Health Care: Towards a commercialization of research results

    NARCIS (Netherlands)

    Konstantas, D.; Bults, Richard G.A.; van Halteren, Aart; Wac, K.E.; Jones, Valerie M.; Widya, I.A.; Herzog, R.; Stormer, H.; Meier, A.; Schumacher, M.

    During the last fours years a consortium of universities, hospitals and commercial companies has been working together for the development of innovative systems and services for mobile health care. Two major projects were financed by the European Union allowed us to develop a complete mobile

  1. 30 CFR 36.4 - Mobile diesel-powered transportation equipment for which certificates of approval may be granted.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mobile diesel-powered transportation equipment... REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT General Provisions § 36.4 Mobile... of approval will be granted for completely assembled mobile diesel-powered transportation equipment...

  2. 33 CFR 165.835 - Security Zone; Port of Mobile, Mobile Ship Channel, Mobile, AL.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Port of Mobile, Mobile Ship Channel, Mobile, AL. 165.835 Section 165.835 Navigation and Navigable Waters COAST GUARD... § 165.835 Security Zone; Port of Mobile, Mobile Ship Channel, Mobile, AL. (a) Definition. As used in...

  3. Mobile inspection and repackaging unit

    International Nuclear Information System (INIS)

    Whitney, G.A.; Roberts, R.J.

    1992-12-01

    Storage of large volumes of radioactive mixed waste (RMW) and transuranic waste generated over the past 20 years at the Hanford Site has resulted in various waste management challenges. Presently disposal capacity for this waste type does not exist. The waste wail be stored until processing facilities can be completed to provide treatment and final disposed. Because of the complexity of these wastes, special projects have been initiated to properly manage them. This paper addresses one such project. The goal of this project is to develop a mobile solid waste inspection and repackaging facility for solid RMW and transuranic waste

  4. Mobility Experiences of Adolescents with Cerebral Palsy

    Science.gov (United States)

    Palisano, Robert J.; Shimmell, Lorie J.; Stewart, Debra; Lawless, John J.; Rosenbaum, Peter L.; Russell, Dianne J.

    2009-01-01

    The purpose of this study was to describe how youth with cerebral palsy experience mobility in their daily lives using a phenomenological approach. The participants were 10 youth with cerebral palsy, 17 to 20 years of age, selected using purposeful sampling with maximum variation strategies. A total of 14 interviews were completed. Transcripts…

  5. Urethral mobilization and advancement for distal hypospadias ...

    African Journals Online (AJOL)

    Background/purpose Despite the existence of numerous techniques for the repair of distal penile hypospadias, none of them is completely satisfactory. Advancing the urethra without mobilization for repair of glanular hypospadias has the advantage of avoiding a common problem occurring with other techniques: ...

  6. MOIDSS?- Mobile Online Intelligent Decision Support System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — GRID has had a successfully completed Phase I 'Mobile Online Intelligent Decision Support System' (MOIDSS). The system developed into a total solution that supports...

  7. Mobile Phone Penetration, Mobile Banking and Inclusive Development in Africa

    OpenAIRE

    Asongu, Simplice; Nwachukwu, Jacinta C.

    2016-01-01

    The study assesses the role of mobile phones and mobile banking in decreasing inequality in 52 African countries. The empirical procedure involves first, examining the income-redistributive effect of mobile phone penetration and then investigating the contribution of mobile banking services in this relationship. The findings suggest an equalizing income-redistributive effect of ‘mobile phone penetration’ and ‘mobile banking’, with a higher income-equalizing effect from mobile banking compared...

  8. The fate of completed intentions.

    Science.gov (United States)

    Anderson, Francis T; Einstein, Gilles O

    2017-04-01

    The goal of this research was to determine whether and how people deactivate prospective memory (PM) intentions after they have been completed. One view proposes that PM intentions can be deactivated after completion, such that they no longer come to mind and interfere with current tasks. Another view is that now irrelevant completed PM intentions exhibit persisting activation, and continue to be retrieved. In Experiment 1, participants were given a PM intention embedded within the ongoing task during Phase 1, after which participants were told either that the PM task had been completed or suspended until later. During Phase 2, participants were instructed to perform only the ongoing task and were periodically prompted to report their thoughts. Critically, the PM targets from Phase 1 reappeared in Phase 2. All of our measures, including thoughts reported about the PM task, supported the existence of persisting activation. In Experiment 2, we varied conditions that were expected to mitigate persisting activation. Despite our best attempts to promote deactivation, we found evidence for the persistence of spontaneous retrieval in all groups after intentions were completed. The theoretical and practical implications of this potential dark side to spontaneous retrieval are discussed.

  9. Improving vaccine registries through mobile technologies: a vision for mobile enhanced Immunization information systems.

    Science.gov (United States)

    Wilson, Kumanan; Atkinson, Katherine M; Deeks, Shelley L; Crowcroft, Natasha S

    2016-01-01

    Immunization registries or information systems are critical to improving the quality and evaluating the ongoing success of immunization programs. However, the completeness of these systems is challenged by a myriad of factors including the fragmentation of vaccine administration, increasing mobility of individuals, new vaccine development, use of multiple products, and increasingly frequent changes in recommendations. Mobile technologies could offer a solution, which mitigates some of these challenges. Engaging individuals to have more control of their own immunization information using their mobile devices could improve the timeliness and accuracy of data in central immunization information systems. Other opportunities presented by mobile technologies that could be exploited to improve immunization information systems include mobile reporting of adverse events following immunization, the capacity to scan 2D barcodes, and enabling bidirectional communication between individuals and public health officials. Challenges to utilizing mobile solutions include ensuring privacy of data, access, and equity concerns, obtaining consent and ensuring adoption of technology at sufficiently high rates. By empowering individuals with their own health information, mobile technologies can also serve as a mechanism to transfer immunization information as individuals cross local, regional, and national borders. Ultimately, mobile enhanced immunization information systems can help realize the goal of the individual, the healthcare provider, and public health officials always having access to the same immunization information. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Complete Normal Ordering 1: Foundations

    CERN Document Server

    Ellis, John; Skliros, Dimitri P.

    2016-01-01

    We introduce a new prescription for quantising scalar field theories perturbatively around a true minimum of the full quantum effective action, which is to `complete normal order' the bare action of interest. When the true vacuum of the theory is located at zero field value, the key property of this prescription is the automatic cancellation, to any finite order in perturbation theory, of all tadpole and, more generally, all `cephalopod' Feynman diagrams. The latter are connected diagrams that can be disconnected into two pieces by cutting one internal vertex, with either one or both pieces free from external lines. In addition, this procedure of `complete normal ordering' (which is an extension of the standard field theory definition of normal ordering) reduces by a substantial factor the number of Feynman diagrams to be calculated at any given loop order. We illustrate explicitly the complete normal ordering procedure and the cancellation of cephalopod diagrams in scalar field theories with non-derivative i...

  11. Making Everyday Mobility

    DEFF Research Database (Denmark)

    Wind, Simon

    2013; Urry 2007) and family theory (Holdsworth 2013; Morgan 2011), it is argued that family mobility is far from only an instrumental phenomenon, displacing family members back and forth between activities and doings, but also a type of family practice (Morgan, 2011) carrying social and emotional...... coping process in the family, it is argued that making and performing mobility practices is to be understood as creating elasticity. Following this, it is elasticity that enables family members to stretch to accommodate the family’s practical, social and emotional conditions as well as adapt......Based upon a qualitative PhD study of 11 families everyday mobility, this paper inquiries into the everyday mobility of families with children in the Greater Copenhagen Area and the role mobility plays in contributing to coping in the families’ everyday life. Drawing on Mobilities theory (Jensen...

  12. Mobilities, Futures & the City

    DEFF Research Database (Denmark)

    Freudendal-Pedersen, Malene; Kesselring, Sven

    2016-01-01

    significant attention to these shifts in societies’ discursive patterns and structures. For making up powerful and strong visions and policies for sustainable cities, ‘collaborative storytelling’ plays a key role. The theoretical outset for the research project ‘Mobilities, Futures & the City’, which grounds......The future of cities and regions will be strongly shaped by the mobilities of people, goods, modes of transport, waste and information. In many ways, the ‘why and ‘for what’ often get lost in discourses on planning and designing mobilities. The predominant planning paradigm still conceptualizes...... the future of cities and mobilities as a matter of rather more efficient technologies than of social cohesion, integration and connectivity. Sustainable mobility needs the mobilities of ideas and concepts and the reflexivity of policies. Communicative planning theory and the ‘argumentative turn’ have given...

  13. CERN Mobility Survey

    CERN Multimedia

    GS Department

    2011-01-01

    The Institute of Shipping and Transport of the University of the Aegean and the National Technical University of Athens are partners with CERN in a study of mobility patterns between and within the CERN sites and to that effect have realized a mobility survey dedicated to the CERN community.         The study aims to understand: How you presently get around the CERN sites; What problems you encounter regarding mobility; What your needs are; What improvements you’d like to see; What measures you would like to see implemented most. The replies we receive will enable us to define a general policy promoting the diversity of mobility at CERN and to establish and quantify the strategic actions to be implemented for both the short and medium term. The objectives of the transport mobility plans are to: Facilitate mobility within and between the CERN sites by identifying adequate solutions in response to individual ...

  14. Social Perspectives on Mobility

    DEFF Research Database (Denmark)

    Uth Thomsen, Thyra; Gudmundsson, Henrik; Drewes Nielsen, Lise

    Globalisation is heavily dependent on physical transport, as people and goods travel over longer distances and with higher frequency. Movement and mobility have become integrated parts of late modern identity and practice, and a state of flux can be sensed everywhere. Bringing together the latest...... interdisciplinary theoretical approaches with empirical case studies analysing and appraising innovative policies from Scandinavia, this volume demonstrates that mobility research is a key issue within social enquiry. It addresses three broad themes. Firstly, mobility as a constructed social reality, examining how...... individuals construct notions of mobility in their everyday life and practice. Secondly, mobility as spatial co-ordination and transgression, and finally, mobility as a policy theme, where the contributors explore recent developments in transport policy at national and European levels, suggesting ways forward...

  15. Embodied Cultures of Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2010-01-01

    and material artifacts. The paper target the complex relationship between the moving, sensing body and the material and built environment of infrastructures and mobility modes in order to explore what norms, and meanings, and everyday life mobility cultures are being produced and re-produced in this process....... A particular emphasis is put on how mobilities produce and re-produce norms, meanings and cultures in relation to the Everyday life perspective. By looking into walking, running, cycling, driving and mass transit mobilities different modes of embodied mobility is identified. The theoretical framework is based...... and interaction (Lynch). The argument is thus that understanding embodied cultures of mobilities from the vantage point of this paper lend is self to new interpretations, explorations and understandings of what it means to move within and between other social agents in particular material and physical...

  16. Use of mobile devices to answer online surveys: implications for research.

    Science.gov (United States)

    Cunningham, John A; Neighbors, Clayton; Bertholet, Nicolas; Hendershot, Christian S

    2013-07-08

    There is a growing use of mobile devices to access the Internet. We examined whether participants who used a mobile device to access a brief online survey were quicker to respond to the survey but also, less likely to complete it than participants using a traditional web browser. Using data from a recently completed online intervention trial, we found that participants using mobile devices were quicker to access the survey but less likely to complete it compared to participants using a traditional web browser. More concerning, mobile device users were also less likely to respond to a request to complete a six week follow-up survey compared to those using traditional web browsers. With roughly a third of participants using mobile devices to answer an online survey in this study, the impact of mobile device usage on survey completion rates is a concern. ClinicalTrials.gov: NCT01521078.

  17. Quality attributes for mobile applications

    OpenAIRE

    Fernandes, João M.; Ferreira, André Leite

    2016-01-01

    A mobile application is a type of software application developed to run on a mobile device. The chapter discusses the main characteristics of mobile devices, since they have a great impact on mobile applications. It also presents the classification of mobile applications according to two main types: native and web-based applications. Finally, this chapter identifies the most relevant types of quality attributes for mobile applications. It shows that the relevant quality attributes for mobile ...

  18. Mobile wallets' business models

    OpenAIRE

    Buchinger, Uschi; Ranaivoson, Heritiana; Ballon, Pieter

    2017-01-01

    Background and Purpose: Though Mobile Wallets have the potential to entirely substitute their physical predecessor, many Mobile Wallets narrow their operations to one particular feature. This might be because of strategic business- model design choices to position themselves strategically as intermediates between users and business partners (third parties) in more delimited markets. Thus, Mobile Wallet Applications (MWAs) often represent platforms in narrow two-sided market structures. De...

  19. Mobile learning in medicine

    Science.gov (United States)

    Serkan Güllüoüǧlu, Sabri

    2013-03-01

    This paper outlines the main infrastructure for implicating mobile learning in medicine and present a sample mobile learning application for medical learning within the framework of mobile learning systems. Mobile technology is developing nowadays. In this case it will be useful to develop different learning environments using these innovations in internet based distance education. M-learning makes the most of being on location, providing immediate access, being connected, and acknowledges learning that occurs beyond formal learning settings, in places such as the workplace, home, and outdoors. Central to m-learning is the principle that it is the learner who is mobile rather than the device used to deliver m learning. The integration of mobile technologies into training has made learning more accessible and portable. Mobile technologies make it possible for a learner to have access to a computer and subsequently learning material and activities; at any time and in any place. Mobile devices can include: mobile phone, personal digital assistants (PDAs), personal digital media players (eg iPods, MP3 players), portable digital media players, portable digital multimedia players. Mobile learning (m-learning) is particularly important in medical education, and the major users of mobile devices are in the field of medicine. The contexts and environment in which learning occurs necessitates m-learning. Medical students are placed in hospital/clinical settings very early in training and require access to course information and to record and reflect on their experiences while on the move. As a result of this paper, this paper strives to compare and contrast mobile learning with normal learning in medicine from various perspectives and give insights and advises into the essential characteristics of both for sustaining medical education.

  20. Mobil Viral Pazarlama

    OpenAIRE

    Barutçu, Süleyman

    2011-01-01

    OBJECTIVE: Mobile Viral Marketing, with using mobile phones, is one of the most importantinnovations after Word of Mouth Marketing performed by face to face amongpeople and Viral Marketing performed in the İnternet. The main objective of thisstudy is to call marketing communicators’ and academicians’ attentions whowant to increase the recognition of companies’ products, services and brands tobecome a current issue in the marketplace using Mobile Viral Marketingapplications by reason of techno...

  1. Structural Completeness in Fuzzy Logics

    Czech Academy of Sciences Publication Activity Database

    Cintula, Petr; Metcalfe, G.

    2009-01-01

    Roč. 50, č. 2 (2009), s. 153-183 ISSN 0029-4527 R&D Projects: GA MŠk(CZ) 1M0545 Institutional research plan: CEZ:AV0Z10300504 Keywords : structral logics * fuzzy logics * structural completeness * admissible rules * primitive variety * residuated lattices Subject RIV: BA - General Mathematics

  2. Quantum space and quantum completeness

    Science.gov (United States)

    Jurić, Tajron

    2018-05-01

    Motivated by the question whether quantum gravity can "smear out" the classical singularity we analyze a certain quantum space and its quantum-mechanical completeness. Classical singularity is understood as a geodesic incompleteness, while quantum completeness requires a unique unitary time evolution for test fields propagating on an underlying background. Here the crucial point is that quantum completeness renders the Hamiltonian (or spatial part of the wave operator) to be essentially self-adjoint in order to generate a unique time evolution. We examine a model of quantum space which consists of a noncommutative BTZ black hole probed by a test scalar field. We show that the quantum gravity (noncommutative) effect is to enlarge the domain of BTZ parameters for which the relevant wave operator is essentially self-adjoint. This means that the corresponding quantum space is quantum complete for a larger range of BTZ parameters rendering the conclusion that in the quantum space one observes the effect of "smearing out" the singularity.

  3. Program Costs and Student Completion

    Science.gov (United States)

    Manning, Terri M.; Crosta, Peter M.

    2014-01-01

    Community colleges are under pressure to increase completion rates, prepare students for the workplace, and contain costs. Colleges need to know the financial implications of what are often perceived as routine decisions: course scheduling, program offerings, and the provision of support services. This chapter presents a methodology for estimating…

  4. Completely integrable operator evolutionary equations

    International Nuclear Information System (INIS)

    Chudnovsky, D.V.

    1979-01-01

    The authors present natural generalizations of classical completely integrable equations where the functions are replaced by arbitrary operators. Among these equations are the non-linear Schroedinger, the Korteweg-de Vries, and the modified KdV equations. The Lax representation and the Baecklund transformations are presented. (Auth.)

  5. Globals of Completely Regular Monoids

    Institute of Scientific and Technical Information of China (English)

    Wu Qian-qian; Gan Ai-ping; Du Xian-kun

    2015-01-01

    An element of a semigroup S is called irreducible if it cannot be expressed as a product of two elements in S both distinct from itself. In this paper we show that the class C of all completely regular monoids with irreducible identity elements satisfies the strong isomorphism property and so it is globally determined.

  6. Complete nitrification by Nitrospira bacteria

    DEFF Research Database (Denmark)

    Daims, Holger; Lebedeva, Elena V.; Pjevac, Petra

    2015-01-01

    Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetic...

  7. The Completeness Theorem of Godel

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. The Completeness Theorem of Godel. 2. Henkin's Proof for First Order Logic. S M Srivastava is with the. Indian Statistical,. Institute, Calcutta. He received his PhD from the Indian Statistical. Institute in 1980. His research interests are in descriptive set theory. I Part 1. An Introduction to Math- ematical ...

  8. Spring valve for well completion

    Energy Technology Data Exchange (ETDEWEB)

    Gorbatov, P T

    1966-07-22

    A spring-loaded valve for well completion consists of a housing with a spring-loaded closing element. In order to protect the closing element from corrosion which might lower the pressure drop, the closing element is made in the form of a piston. It is tightly connected with sealing elements. The housing has orifices, overlapping the piston in the initial position.

  9. Largest particle detector nearing completion

    CERN Multimedia

    2006-01-01

    "Construction of another part of the Large Hadron Collider (LHC), the worl's largest particle accelerator at CERN in Switzerland, is nearing completion. The Compact Muon Solenoid (CMS) is oner of the LHC project's four large particle detectors. (1/2 page)

  10. YB0 SERVICES INSTALLATION COMPLETED

    CERN Document Server

    The beauty of the completed YB0 was briefly visible at P5 as preparations continue for Tracker installation. A tremendous effort, lasting 7 months and involving more than 100 workers on the busiest days, resulted in 5700 electrical cables, 780 optical cables with 65k fibre channels, and 550 pipes laid on YB0 for HB, EB and Tracker.

  11. Keeping communication mobile

    International Nuclear Information System (INIS)

    Latimer, Cole

    2010-01-01

    While mobile phones are ubiquitous in nearly all walks of Australia industry, there is still one sector were the technology has been unsurprisingly absent. Aside from the obvious operational hazards that a mobile phone would encounter when being used underground, such as harsh working conditions, dust and heavy knocks, the technology required to actually use a mobile at depths has been in the early stages for some time. However and Australian company, Mine Site Technologies, has taken a leap into this space by designing the world's first mobile phone for underground mining

  12. Mobile Solar Tracker Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NIST's mobile solar tracking facility is used to characterize the electrical performance of photovoltaic panels. It incorporates meteorological instruments, a solar...

  13. Programming the Mobile Web

    CERN Document Server

    Firtman, Maximiliano

    2010-01-01

    Today's market for mobile apps goes beyond the iPhone to include BlackBerry, Nokia, Windows Phone, and smartphones powered by Android, webOS, and other platforms. If you're an experienced web developer, this book shows you how to build a standard app core that you can extend to work with specific devices. You'll learn the particulars and pitfalls of building mobile apps with HTML, CSS, and other standard web tools. You'll also explore platform variations, finicky mobile browsers, Ajax design patterns for mobile, and much more. Before you know it, you'll be able to create mashups using Web 2.

  14. Mobile Test Capabilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Power Mobile Test capabilities are utilized to conduct electrical power quality testing on aircraft and helicopters. This capability allows that the...

  15. Best Sale Mobile Application

    OpenAIRE

    Chittugnanamoorthy, Balakumar

    2014-01-01

    The aim of this thesis was to find a best way to advertise short-term sales and reduce paper waste. Another aim was to help the seller to identify a potential customer for a specific product, by means of providing a number of people accessing an advertisement. A mobile phone is one of the widely used electronic devices by many people. Modern mobile phones support a good internet connection. Also, people carry their mobile devices with them even outside their homes. So a mobile application ...

  16. Proxemic Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Porcheron, Martin; Lucero, Andrés; Quigley, Aaron

    2016-01-01

    and their digital devices (i.e. the proxemic relationships). Building on the ideas of proxemic interactions, this workshop is motivated by the concept of ‘proxemic mobile collocated interactions’, to harness new or existing technologies to create engaging and interactionally relevant experiences. Such approaches......Recent research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices. However, existing practices fail to fully account for the culturally-dependent spatial relationships between people...... in exploring proxemics and mobile collocated interactions....

  17. Practical mobile forensics

    CERN Document Server

    Bommisetty, Satish; Mahalik, Heather

    2014-01-01

    The book is an easy-to-follow guide with clear instructions on various mobile forensic techniques. The chapters and the topics within are structured for a smooth learning curve, which will swiftly empower you to master mobile forensics. If you are a budding forensic analyst, consultant, engineer, or a forensic professional wanting to expand your skillset, this is the book for you. The book will also be beneficial to those with an interest in mobile forensics or wanting to find data lost on mobile devices. It will be helpful to be familiar with forensics in general but no prior experience is re

  18. Mobile computing handbook

    CERN Document Server

    Ilyas, Mohammad

    2004-01-01

    INTRODUCTION AND APPLICATIONS OF MOBILE COMPUTING Wearable Computing,A. Smailagic and D.P. Siewiorek Developing Mobile Applications: A Lime Primer,G.P. Picco, A.L. Murphy, and G.-C. Roman Pervasive Application Development: Approaches and Pitfalls,G. Banavar, N. Cohen, and D. Soroker ISAM, Joining Context-Awareness and Mobility to Building Pervasive Applications,I. Augustin, A. Corrêa Yamin, J.L. Victória Barbosa, L. Cavalheiro da Silva, R. Araújo Real, G. Frainer, G.G. Honrich Cavalheiro, and C.F. Resin Geyer Integrating Mobile Wireless Devices into the Computational Grid,T. Phan, L. Huan

  19. Cooperative Mobile Web Browsing

    DEFF Research Database (Denmark)

    Perrucci, GP; Fitzek, FHP; Zhang, Qi

    2009-01-01

    This paper advocates a novel approach for mobile web browsing based on cooperation among wireless devices within close proximity operating in a cellular environment. In the actual state of the art, mobile phones can access the web using different cellular technologies. However, the supported data......-range links can then be used for cooperative mobile web browsing. By implementing the cooperative web browsing on commercial mobile phones, it will be shown that better performance is achieved in terms of increased data rate and therefore reduced access times, resulting in a significantly enhanced web...

  20. Mobile Project Management

    Directory of Open Access Journals (Sweden)

    Catalin BOJA

    2006-01-01

    Full Text Available Based on the development of new communication and data transfer technologies, the mobile solutions for the management process have been able to provide new ways to conduct management actions. This environment describes methods and tools available only here, which will bring information, speed and efficiency to any stage and component of the management process. The paper takes into discussion the impact of the technological development on the management process paradigm. The paper presents the main aspects regarding the business and management models used in mobile management. The role of mobile multimedia informatics applications in mobile management is highlighted.

  1. Mobility Charters and Manifestos

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    2010-01-01

    This paper explore a number of different cases of articulating notions of ‘correct’ mobility behavior and practice by looking into charters, manifestos and codes of mobility regulation. Within such discourses of ‘correct mobility’ more or less subtle expressions of power as well as normative and ...... ‘Highway Code Booklets’ from the 1930’s, 40’s and 50’s, the ‘City Slow Charter’, the ‘New Urbanism Charter’ as attempts to codify and order mobility and mobile practices.......This paper explore a number of different cases of articulating notions of ‘correct’ mobility behavior and practice by looking into charters, manifestos and codes of mobility regulation. Within such discourses of ‘correct mobility’ more or less subtle expressions of power as well as normative...... and ethical positions on mobility prevail. Such ‘imagined correct mobility behavior’ are drawing on larger issues of societal change that need to be brought out in a critical analysis and discussion reflecting the attempts to control, design and orchestrate mobility patterns. The paper therefore argues within...

  2. The setup of a mobile mobility panel for the Netherlands

    NARCIS (Netherlands)

    Geurs, Karst Teunis; Veenstra, Sander; Thomas, Tom

    2013-01-01

    This paper describes the setup of the Dutch Mobile Mobility Panel project, in which GPS-enabled mobile phones (smartphones) are used as a passive multiple-week and multiple-year travel behaviour data collection tool. The data collection methodology used in the Dutch Mobile Mobility Panel comprised

  3. Mobile lifestyles : Conceptualizing heterogeneity in mobile youth culture

    NARCIS (Netherlands)

    Vanden Abeele, M.M.P.

    2014-01-01

    Adolescents’ characteristic understanding and use of mobile phones have led observers to speak of a “mobile youth culture.” This article explores whether we can differentiate lifestyles within mobile youth culture. We construct a user typology of Flemish adolescent mobile phone users based on mobile

  4. OS Independent Mobile Solutions for Manufacturing Execution Systems

    Directory of Open Access Journals (Sweden)

    Heiko Meyer

    2013-12-01

    Full Text Available From the suppliers' perspective it is best to provide the user of a plant with a mobile solution in the form of perfectly matching Apps for the rolled-out manufacturing execution system. Due to the extremely short innovation cycle in the mobile phone development and not least because of the first iPhone generation launch in 2007 the mobile phone market completely changed over the past four years. Today, a large percentage of the sold devices can be classified as smart phones. The paper describes an easy and reliable way to develop OS independent mobile solutions for all common smartphones based on standard technologies.

  5. Student Use of Mobile Devices in Course Evaluation: A Longitudinal Study

    Science.gov (United States)

    Champagne, Matthew V.

    2013-01-01

    A 2012 survey of higher education found that 27% of colleges and universities were "mobile ready", that is, allowing students to complete course evaluations via mobile devices, and 26% of schools planned to allow the use of mobile devices for course evaluations within the next year. The purpose of this study was to prepare for this…

  6. Mobilizing community energy

    International Nuclear Information System (INIS)

    Bomberg, Elizabeth; McEwen, Nicola

    2012-01-01

    What explains the galvanising of communities to participate actively in energy projects? How do groups mobilize to overcome the often formidable barriers highlighted in the existing literature? Drawing on original qualitative research of 100 community energy groups in Scotland, including six in-depth case studies, we explain how effective mobilization occurs and the political dynamics surrounding such mobilization. To capture these dynamics, we adapt theories offered by literature on social movements, with a particular focus on resource mobilization theories. Applying our adapted framework, we identify two particular sets of resources shaping community energy mobilization: (i) structural resources, which refer to the broad political context structuring and constraining opportunities for community energy mobilization; and (ii) symbolic resources—less tangible resources used to galvanise participants. We investigate to what extent our case study groups were able to draw upon and exploit these resources. We find that structural resources can either facilitate or hinder mobilization; what matters is how state resources are exploited and constraints mitigated. The use of symbolic resources was highly effective in aiding mobilization. Each of the groups examined – despite their considerable variation – effectively exploited symbolic resources such as shared identity or desire for strong, self reliant communities. - Highlights: ► Explains how/why community energy groups mobilize and the political dynamics surrounding it. ► Draws on original qualitative research of 100 community energy groups in Scotland. ► Identifies two particular sets of resources (structural and symbolic) and their importance. ► Explains how these resources shape community energy mobilization in Scotland. ► Provides an original application of resource mobilization theory to the field of energy studies.

  7. Fermentation characteristics in conversion of organic acids obtained by oxidation of low-rank coals to poly({beta}-hydroxybutyrate) using A. eutrophus cells with some analysis on metabolic flux distribution; Kattan no ekisosanka de erareru yukisan wo suiso saikin wo riyoshite pori {beta}-hidorokishi rakusan (PHB) ni henkansaseru tameno baiyo kogakuteki kento to taisha ryusoku bunpu shisutemu kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Tsujimoto, Shoko.; Shin, Huidong.; Shimizu, Kazuyuki. [Kyushu Institute of Technology, Fukuoka (Japan). Department of Biochemical engineering and science; Mae, Kazuhiro.; Miura, Koichi. [Kyoto University, Kyoto (Japan). Department of Chemical Engineering

    1999-03-10

    Fermentation characteristics are investigated for the conversion of glycolate, acetate, formate, and malonate obtained by the oxidation of low-rank coals to poly ({beta}-hydrox butyrate) (PHB) using A. eutrophus cells. Based on the cultivation experiments using one of the organic acids as a sole carbon source, it is found that acetate is the most effectively converted to PHB. When mixed organic acids are used, formate is preferentially consumed, followed by acetate, and finally glycolate. Although malate can not be utilized, it is implied that it might change the pathway flux distributions based on the metabolic flux analysis. Namely, it shows competitive inhibition to succinate dehydrogenase so that its addition during fermentation results in flux reduction from succinate to maleic acid as well as glyoxylate flux and gluconeogenesis flux. It is also found that NADPH generated from isocitrate is preferentially utilized for the reaction from {alpha}-ketoglutarate to glutamate when NH{sub 3} concentration is high, while it is eventually used for the PHB production from acetoacetyl CoA as NH{sub 3} concentration decreases. (author)

  8. Complete spacelike immersions with topology

    International Nuclear Information System (INIS)

    Harris, S.G.

    1988-01-01

    A fairly large class of Lorentz manifolds is defined, called WH normal manifolds, which are approximately those for which timelike infinity is a single point. It is shown that, in such a space, an immersed spacelike hypersurface which is complete must, if it is self-intersecting, not achronal or proper, satisfy strong topological conditions; in particular, if the immersion is injective in the fundamental group, then the hypersurface must be closed, embedded and achronal (i.e. a partial Cauchy surface). WH normal spaces include products of any Riemannian manifold with Minkowski 1-space; in such space, a complete immersed spacelike hypersurface must be immersed as a covering space for the Riemannian factor. (author)

  9. Completeness in Hybrid Type Theory

    DEFF Research Database (Denmark)

    Areces, Carlos; Blackburn, Patrick Rowan; Huertas, Antonia

    2014-01-01

    We show that basic hybridization (adding nominals and @ operators) makes it possible to give straightforward Henkin-style completeness proofs even when the modal logic being hybridized is higher-order. The key ideas are to add nominals as expressions of type t, and to extend to arbitrary types th......-style intensional models; we build, as simply as we can, hybrid logicover Henkin’s logic...

  10. [Anterior guidance in complete dentures].

    Science.gov (United States)

    Dubreuil, J; Trevelo, A

    1990-01-01

    Although the anterior guidance in complete dentures is not really a guide, the arrangement of the anterior maxillary and mandibular prosthetic teeth, defines a propulsive line called the virtual anterior guidance, a part from the cinematic criterias. The influence of this guide on cuspal movement is superior, in all mandibular points, to the influence of the condylar pathway. If this line is not respected, the practitioner may have to do excessive grindings during occlusal adjustments.

  11. Efficient Completion of Weighted Automata

    Directory of Open Access Journals (Sweden)

    Johannes Waldmann

    2016-09-01

    Full Text Available We consider directed graphs with edge labels from a semiring. We present an algorithm that allows efficient execution of queries for existence and weights of paths, and allows updates of the graph: adding nodes and edges, and changing weights of existing edges. We apply this method in the construction of matchbound certificates for automatically proving termination of string rewriting. We re-implement the decomposition/completion algorithm of Endrullis et al. (2006 in our framework, and achieve comparable performance.

  12. Grizzli mobile systems and LPG delivery management; Grizzli mobile systems

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-07-01

    Complete text of publication follows: Grizzli Mobile Systems (and its sister companies) specialists in data communications and system solutions, offer their complete management solution for LPG deliveries, right through from remote reading of the gas level in the tank, through route management, management of the delivery itself and finally on-site invoicing and payment. The system permits a supplier to really differentiate itself from its competitors in terms of customer service and control of its operations. Domestic gas tanks are often difficult to access; visual reading of the gauge is not always easy and often leads to the customer re-ordering in panic mode. The supplier has also to react in panic mode to the customer. Grizzli Mobile Systems has developed a radio module that is fitted to the gas tank that calls, at regular set intervals with the tank level to a Call Rider gateway plug. The Call Rider is a small box plugged into the regular telephone socket (also supplying multiple operator telephony and other home automation services). As soon as the gas level reaches a predetermined minimum level, this radio information is relayed via the Internet to the LPG supplier. The supplier can then arrange (in non-panic mode) to deliver gas to the customer, via conventional means or by use of an interactive radio display (attached to a refrigerator or similar by magnets) that communicates with the Call Rider by radio. Once a delivery date has been set, a Grizzli Mobile Systems' dispatch system, installed at the supplier's headquarters creates and transfers routes via GSM communications to its fleet of delivery vehicles. A main-frame mapping software provides real-time follow-up and status checks of the vehicles using the GPS functionality and imports data back from the vehicles and updates databases. The driver is also assisted in localizing delivery sites. Inside the cabin of the vehicle the driver has available a Fujitsu PenCentra pen computer, a Microsoft

  13. Mobile human-computer interaction perspective on mobile learning

    CSIR Research Space (South Africa)

    Botha, Adèle

    2010-10-01

    Full Text Available Applying a Mobile Human Computer Interaction (MHCI) view to the domain of education using Mobile Learning (Mlearning), the research outlines its understanding of the influences and effects of different interactions on the use of mobile technology...

  14. Complete normal ordering 1: Foundations

    Directory of Open Access Journals (Sweden)

    John Ellis

    2016-08-01

    Full Text Available We introduce a new prescription for quantising scalar field theories (in generic spacetime dimension and background perturbatively around a true minimum of the full quantum effective action, which is to ‘complete normal order’ the bare action of interest. When the true vacuum of the theory is located at zero field value, the key property of this prescription is the automatic cancellation, to any finite order in perturbation theory, of all tadpole and, more generally, all ‘cephalopod’ Feynman diagrams. The latter are connected diagrams that can be disconnected into two pieces by cutting one internal vertex, with either one or both pieces free from external lines. In addition, this procedure of ‘complete normal ordering’ (which is an extension of the standard field theory definition of normal ordering reduces by a substantial factor the number of Feynman diagrams to be calculated at any given loop order. We illustrate explicitly the complete normal ordering procedure and the cancellation of cephalopod diagrams in scalar field theories with non-derivative interactions, and by using a point splitting ‘trick’ we extend this result to theories with derivative interactions, such as those appearing as non-linear σ-models in the world-sheet formulation of string theory. We focus here on theories with trivial vacua, generalising the discussion to non-trivial vacua in a follow-up paper.

  15. Security for Mobility

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming; Buchholtz, Mikael

    2004-01-01

    We show how to use static analysis to provide information about security issues related to mobility. First the syntax and semantics of Mobile Ambients is reviewed and we show how to obtain a so-called 0CFA analysis that can be implemented in polynomial time. Next we consider discretionary access...

  16. Security for Mobility

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming; Buchholtz, Mikael

    2002-01-01

    We show how to use static analysis to provide information about security issues related to mobility. First the syntax and semantics of Mobile Ambients is reviewed and we show how to obtain a so-called 0CFA analysis that can be implemented in polynomial time. Next we consider discretionary access...

  17. Mobile banking in Asia

    OpenAIRE

    Anne Ho

    2010-01-01

    Technology has transformed the banking industry with the introduction of mobile banking services that offer unprecedented convenience and accessibility to customers. This Asia Focus report describes the various approaches to mobile banking in Asia, and examines how particular countries have addressed regulatory issues.

  18. Mobile Christian - shuttle flight

    Science.gov (United States)

    2009-01-01

    Erin Whittle, 14, (seated) and Brianna Johnson, 14, look on as Louis Stork, 13, attempts a simulated landing of a space shuttle at StenniSphere. The young people were part of a group from Mobile Christian School in Mobile, Ala., that visited StenniSphere on April 21.

  19. Designing for mobile interaction

    DEFF Research Database (Denmark)

    Nazzi, Elena

    2009-01-01

    The theme of this PhD project is designing for mobile interaction with devices and services, for the accessing, making, and sharing of information, taking into account the dynamic physical and social settings that embrace this interaction. To narrow down this theme, the whole project focuses...... on the exploitation of social interaction --- in particular among senior citizens --- to enhance and support mobile interaction....

  20. Mobile phone; Mobiltelefon

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Almost the entire Norwegian population has cell phone. The usefulness of the cell phone is great, but can use a mobile phone to health or discomfort? How can exposure be reduced? NRPA follows research and provides advice on mobile phone use. (AG)

  1. Mastering Mobile Security

    Science.gov (United States)

    Panettieri, Joseph C.

    2007-01-01

    Without proper security, mobile devices are easy targets for worms, viruses, and so-called robot ("bot") networks. Hackers increasingly use bot networks to launch massive attacks against eCommerce websites--potentially targeting one's online tuition payment or fundraising/financial development systems. How can one defend his mobile systems against…

  2. Mobile communication security

    NARCIS (Netherlands)

    Broek, F.M.J. van den

    2016-01-01

    Security of the mobile network Fabian van den Broek We looked at the security of the wireless connection between mobile phone and cell towers and suggested possible improvements. The security was analysed on a design level, by looking at the protocols and encryption techniques, but also on an

  3. Mobile spectrometric laboratory

    International Nuclear Information System (INIS)

    Isajenko, K.A.; Lipinski, P.

    2002-01-01

    The article presents the Mobile Spectrometric Laboratory used by Central Laboratory for Radiological Protection since year 2000. The equipment installed in the Mobile Laboratory and its uses is described. The results of international exercises and intercalibrations, in which the Laboratory participated are presented. (author)

  4. Mobile Apps for Librarians

    Science.gov (United States)

    Power, June L.

    2013-01-01

    In an increasing mobile environment, library and reading-related activities often take place on a phone or tablet device. Not only does this mean that library Web sites must keep mobile navigability in mind, but also develop and utilize apps that allow patrons to interact with information and with libraries. While apps do not serve every purpose,…

  5. Mobile-first Bootstrap

    CERN Document Server

    Magno, Alexandre

    2013-01-01

    A practical, step-by-step tutorial on developing websites for mobile using Bootstrap.This book is for anyone who wants to get acquainted with the new features available in Bootstrap 3 and who wants to develop websites with the mobile-first feature of Bootstrap. The reader should have a basic knowledge of Bootstrap as a frontend framework.

  6. Understanding mobile information needs

    OpenAIRE

    Church, Karen; Smyth, Barry

    2008-01-01

    In this paper we describe the results of a four-week diary study of mobile information needs, focusing on the intent behind mobile needs and the importance on context on such needs. We identified three key intents among diary entries: informational, geographical and personal information management (PIM). Furthermore, we found many of these information needs have high temporal and location dependencies.

  7. Mobile Informal Learning

    NARCIS (Netherlands)

    Börner, Dirk; Glahn, Christian; Specht, Marcus

    2009-01-01

    Börner, D., Glahn, C., & Specht, M. (2009). Mobile Informal Learning. Presentation for the Education in the Wild: contextual and location-based mobile learning in action workshop at the STELLAR Alpine Rendez-Vous 2009. November, 30-December, 3, 2009, Garmisch-Partenkirchen, Germany.

  8. Innovazione nel mobile learning

    Directory of Open Access Journals (Sweden)

    Immaculada Arnedillo-Sànchez

    2008-01-01

    Full Text Available Descrizione, da una prospettiva europea, dell’innovazione nel settore del mobile learning e l’utilizzabilita’ del mobile learning in contesti educativi. Vengono illustrate i principali progetti europei di m-learning e si esamina le prospettive pedagogiche e teoriche relative al campo.

  9. Cordless telephone use: implications for mobile phone research.

    Science.gov (United States)

    Redmayne, Mary; Inyang, Imo; Dimitriadis, Christina; Benke, Geza; Abramson, Michael J

    2010-04-01

    Cordless and mobile (cellular) telephone use has increased substantially in recent years causing concerns about possible health effects. This has led to much epidemiological research, but the usual focus is on mobile telephone radiofrequency (RF) exposure only despite cordless RF being very similar. Access to and use of cordless phones were included in the Mobile Radiofrequency Phone Exposed Users Study (MoRPhEUS) of 317 Year 7 students recruited from Melbourne, Australia. Participants completed an exposure questionnaire-87% had a cordless phone at home and 77% owned a mobile phone. There was a statistically significant positive relationship (r = 0.38, p < 0.01) between cordless and mobile phone use. Taken together, this increases total RF exposure and its ratio in high-to-low mobile users. Therefore, the design and analysis of future epidemiological telecommunication studies need to assess cordless phone exposure to accurately evaluate total RF telephone exposure effects.

  10. Children's velo-mobility

    DEFF Research Database (Denmark)

    Carstensen, Trine Agervig; Nielsen, Thomas Sick; Olafsson, Anton Stahl

    2014-01-01

    . How cycling is learned and constituted, and how cycling skills are consolidated, extended and turned into a stabilized practice remains unstudied. Drawing on in-depth interview data from the region of Copenhagen, Denmark, among families with children (N=20) the paper provides new insights into how......Sustainable mobilities play a dominate role in low carbon futures and cycling is an integral element. Children are heirs of transport cultures and crucial for future sustainable mobility. Moreover cycling is important for children’s independent mobility and geographical experience. Dominating...... approaches in transport research, including cycling, understand travel behaviour individualistic and lack to grasp the relational complexities, which are inevitable when considering children’s mobilities. Furthermore has children’s cycling largely been studied as independent mobility and active school travel...

  11. Mobilities and Representations

    DEFF Research Database (Denmark)

    Thelle, Mikkel

    2017-01-01

    to consider how they and their peers are currently confronting representations of mobility. This is particularly timely given the growing academic focus on practices, material mediation, and nonrepresentational theories, as well as on bodily reactions, emotions, and feelings that, according to those theories......As the centerpiece of the eighth T2M yearbook, the following interview about representations of mobility signals a new and exciting focus area for Mobility in History. In future issues we hope to include reviews that grapple more with how mobilities have been imagined and represented in the arts......, literature, and film. Moreover, we hope the authors of future reviews will reflect on the ways they approached those representations. Such commentaries would provide valuable methodological insights, and we hope to begin that effort with this interview. We have asked four prominent mobility scholars...

  12. Mobile Collocated Interactions

    DEFF Research Database (Denmark)

    Lucero, Andrés; Clawson, James; Lyons, Kent

    2015-01-01

    Mobile devices such as smartphones and tablets were originally conceived and have traditionally been utilized for individual use. Research on mobile collocated interactions has been looking at situations in which collocated users engage in collaborative activities using their mobile devices, thus...... going from personal/individual toward shared/multiuser experiences and interactions. However, computers are getting smaller, more powerful, and closer to our bodies. Therefore, mobile collocated interactions research, which originally looked at smartphones and tablets, will inevitably include ever......-smaller computers, ones that can be worn on our wrists or other parts of the body. The focus of this workshop is to bring together a community of researchers, designers and practitioners to explore the potential of extending mobile collocated interactions to the use of wearable devices....

  13. MOBILIZING KNOWLEDGE IN DENMARK

    DEFF Research Database (Denmark)

    Holm, Claus

    2011-01-01

    Knowledge mobilization is not only a new expression in a Danish context. It is also an interesting concept to introduce and discuss. For doesn’t knowledge mobilization have more – or, at least, as much – to do with politics as with education research or education in itself? Doesn’t modern knowledge...... mobilization have to do with a new political will to mobilize the population by creating a connection between education research and education? On the basis of this report on the Danish efforts with respect to ’knowledge mobilization’, these questions can be answered affirmatively; the extent of knowledge...... competition state – that is to be realized by fulfilling the ambitions for comprehensive knowledge mobilization through education.1 On the other hand, Denmark is having a hard time finding a broad consensus when what is, in principle, supposed to be a common political will is to be translated into knowledge...

  14. ESCAP mobile training scheme.

    Science.gov (United States)

    Yasas, F M

    1977-01-01

    In response to a United Nations resolution, the Mobile Training Scheme (MTS) was set up to provide training to the trainers of national cadres engaged in frontline and supervisory tasks in social welfare and rural development. The training is innovative in its being based on an analysis of field realities. The MTS team consisted of a leader, an expert on teaching methods and materials, and an expert on action research and evaluation. The country's trainers from different departments were sent to villages to work for a short period and to report their problems in fulfilling their roles. From these grass roots experiences, they made an analysis of the job, determining what knowledge, attitude and skills it required. Analysis of daily incidents and problems were used to produce indigenous teaching materials drawn from actual field practice. How to consider the problems encountered through government structures for policy making and decisions was also learned. Tasks of the students were to identify the skills needed for role performance by job analysis, daily diaries and project histories; to analyze the particular community by village profiles; to produce indigenous teaching materials; and to practice the role skills by actual role performance. The MTS scheme was tried in Nepal in 1974-75; 3 training programs trained 25 trainers and 51 frontline workers; indigenous teaching materials were created; technical papers written; and consultations were provided. In Afghanistan the scheme was used in 1975-76; 45 participants completed the training; seminars were held; and an ongoing Council was created. It is hoped that the training program will be expanded to other countries.

  15. Mobile Health Information System: A Mobile App

    African Journals Online (AJOL)

    Steve

    It is predicted that mobile technology will have a big impact in healthcare, especially in developing countries. .... Information dissemination is done with the use of posters, fliers and mass media. Below is a picture of what it looks like. Fig 3.2: ...

  16. Mobility management in the future mobile network

    NARCIS (Netherlands)

    Karimzadeh Motallebi Azar, Morteza

    2018-01-01

    The current mobile network architectures are heavily hierarchical, which implies that all traffic must be traversed through a centralized core entity. This makes the network prone to several limitations, e.g., suboptimal communication paths, low scalability, signaling overhead, and single point of

  17. Mobile work: Ergonomics in a rapidly changing work environment.

    Science.gov (United States)

    Honan, Meg

    2015-01-01

    Places of work have been completely transformed by innovations in mobile work tools and ever-present access to internet data. This article characterizes use patterns and provides preliminary considerations for productive and comfortable use of common mobile devices. Two surveys described trends in mobile work. In the first, ergonomics professionals who oversee programs reported common mobile devices, their users and what data is accessed. The second, an end user survey, explored common activities performed on mobile devices, duration of use and locations where mobile work is common. The survey results provide a baseline data point for the status of mobile work in early 2014. Research indicates that additional risks have been introduced to the neck, thumbs and hands when using mobile devices. Possible trends regarding device use and work locations emerge. Intervention studies provide some direction for the practitioner. Practical strategies are outlined to reduce exposure intensity and duration. Contemporary mobile work presents tremendous change and opportunity for ergonomists and researchers to keep pace with fitting the changing models of work to the person. Continued research is needed on current mobile device use patterns to better understand ergonomic risk exposure in this rapidly changing realm.

  18. The Mobile Phone Affinity Scale: Enhancement and Refinement

    Science.gov (United States)

    Rosen, Rochelle K

    2016-01-01

    Background Existing instruments that assess individuals’ relationships with mobile phones tend to focus on negative constructs such as addiction or dependence, and appear to assume that high mobile phone use reflects pathology. Mobile phones can be beneficial for health behavior change, disease management, work productivity, and social connections, so there is a need for an instrument that provides a more balanced assessment of the various aspects of individuals’ relationships with mobile phones. Objective The purpose of this research was to develop, revise, and validate the Mobile Phone Affinity Scale, a multi-scale instrument designed to assess key factors associated with mobile phone use. Methods Participants (N=1058, mean age 33) were recruited from Amazon Mechanical Turk between March and April of 2016 to complete a survey that assessed participants’ mobile phone attitudes and use, anxious and depressive symptoms, and resilience. Results Confirmatory factor analysis supported a 6-factor model. The final measure consisted of 24 items, with 4 items on each of 6 factors: Connectedness, Productivity, Empowerment, Anxious Attachment, Addiction, and Continuous Use. The subscales demonstrated strong internal consistency (Cronbach alpha range=0.76-0.88, mean 0.83), and high item factor loadings (range=0.57-0.87, mean 0.75). Tests for validity further demonstrated support for the individual subscales. Conclusions Mobile phone affinity may have an important impact in the development and effectiveness of mobile health interventions, and continued research is needed to assess its predictive ability in health behavior change interventions delivered via mobile phones. PMID:27979792

  19. Juvenile eye growth, when completed?

    DEFF Research Database (Denmark)

    Fledelius, Hans C; Christensen, Anders S; Fledelius, Christian

    2014-01-01

    PURPOSE: To test Sorsby's classical statement of axial eye growth as completed at the age of 13 years, with a view also to differentiating between basic eye growth and juvenile elongation associated with eventual refractive change towards myopia. METHODS: (i) A total of 160 healthy eyes close...... about age 13 as general limit found support from the cross-sectional data, which suggested stable emmetropic eye size from about 11-12 years, with an average apparently outgrown male emmetropic value of 23.5 mm versus females' 22.9 mm. The longitudinal data, however, showed emmetropic growth also beyond...

  20. Projective modules and complete intersections

    CERN Document Server

    Mandal, Satya

    1997-01-01

    In these notes on "Projective Modules and Complete Intersections" an account on the recent developments in research on this subject is presented. The author's preference for the technique of Patching isotopic isomorphisms due to Quillen, formalized by Plumsted, over the techniques of elementary matrices is evident here. The treatment of Basic Element theory here incorporates Plumstead's idea of the "generalized dimension functions". These notes are highly selfcontained and should be accessible to any graduate student in commutative algebra or algebraic geometry. They include fully self-contained presentations of the theorems of Ferrand-Szpiro, Cowsik-Nori and the techniques of Lindel.

  1. The Bluetooth Based LED Control For Arduino Test Platform By Using Mobile APP

    OpenAIRE

    Yi-Jen Mon

    2015-01-01

    Abstract The Bluetooth is a commonly known convenient and famous communication protocol. In this paper it is used to control LED mounted on Arduino test platform by using the APP of mobile phone. At first the control program is completed by Arduino development software environment then the Android APP is installed in mobile phone. Finally by using the Bluetooth of mobile phone the test platform will be connected. The LED can be controlled by APP of mobile phone. The experiment results are dem...

  2. Exploration of mobile educational technology

    OpenAIRE

    Hosny, W.

    2007-01-01

    Recent advances in mobile and wireless technology could be utilised to enhance the delivery of educational programmes. The use of this technology is known as “Mobile Education”. Mobile education technology provides unique opportunities for educators to flexibly deliver their educational material to learners via mobile services anywhere at any time. Moreover, the material delivered could be adapted to the learners’ needs and preferences. Examples of mobile devices which could be used in mobile...

  3. Client Mobile Software Design Principles for Mobile Learning Systems

    Directory of Open Access Journals (Sweden)

    Qing Tan

    2009-01-01

    Full Text Available In a client-server mobile learning system, client mobile software must run on the mobile phone to acquire, package, and send student’s interaction data via the mobile communications network to the connected mobile application server. The server will receive and process the client data in order to offer appropriate content and learning activities. To develop the mobile learning systems there are a number of very important issues that must be addressed. Mobile phones have scarce computing resources. They consist of heterogeneous devices and use various mobile operating systems, they have limitations with their user/device interaction capabilities, high data communications cost, and must provide for device mobility and portability. In this paper we propose five principles for designing Client mobile learning software. A location-based adaptive mobile learning system is presented as a proof of concept to demonstrate the applicability of these design principles.

  4. Completion of the TRT Barrel

    CERN Multimedia

    Gagnon, P

    On February 3, the US-TRT team proudly completed the installation of the 96th barrel TRT module on its support structure in the SR building at CERN. This happy event came after many years of R&D initiated in the nineties by the TA1 team at CERN, followed by the construction of the modules in three American institutes (Duke, Hampton and Indiana Universities) from 1996 to 2003. In total, the 96 barrel modules contain 52544 kapton straws, each 4 mm in diameter and strung with a 30 micron gold-plated tungsten wire. Each wire was manually inserted, a feat in itself! The inner layer modules contain 329 straws, the middle layer modules have 520 straws and the outer layer, 793 straws. Thirty- two modules of each type form a full layer. Their special geometry was designed such as to leave no dead region. On average, a particle will cross 36 straws. Kirill Egorov, Chuck Mahlon and John Callahan inserted the last module in the Barrel Support Structure. After completion in the US, all modules were transferred...

  5. LHCf completes its first run

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    LHCf, one of the three smaller experiments at the LHC, has completed its first run. The detectors were removed last week and the analysis of data is continuing. The first results will be ready by the end of the year.   One of the two LHCf detectors during the removal operations inside the LHC tunnel. LHCf is made up of two independent detectors located in the tunnel 140 m either side of the ATLAS collision point. The experiment studies the secondary particles created during the head-on collisions in the LHC because they are similar to those created in a cosmic ray shower produced when a cosmic particle hits the Earth’s atmosphere. The focus of the experiment is to compare the various shower models used to estimate the primary energy of ultra-high-energy cosmic rays. The energy of proton-proton collisions at the LHC will be equivalent to a cosmic ray of 1017eV hitting the atmosphere, very close to the highest energies observed in the sky. “We have now completed the fir...

  6. Complete family of separability criteria

    International Nuclear Information System (INIS)

    Doherty, Andrew C.; Spedalieri, Federico M.; Parrilo, Pablo A.

    2004-01-01

    We introduce a family of separability criteria that are based on the existence of extensions of a bipartite quantum state ρ to a larger number of parties satisfying certain symmetry properties. It can be easily shown that all separable states have the required extensions, so the nonexistence of such an extension for a particular state implies that the state is entangled. One of the main advantages of this approach is that searching for the extension can be cast as a convex optimization problem known as a semidefinite program. Whenever an extension does not exist, the dual optimization constructs an explicit entanglement witness for the particular state. These separability tests can be ordered in a hierarchical structure whose first step corresponds to the well-known positive partial transpose (Peres-Horodecki) criterion, and each test in the hierarchy is at least as powerful as the preceding one. This hierarchy is complete, in the sense that any entangled state is guaranteed to fail a test at some finite point in the hierarchy, thus showing it is entangled. The entanglement witnesses corresponding to each step of the hierarchy have well-defined and very interesting algebraic properties that, in turn, allow for a characterization of the interior of the set of positive maps. Coupled with some recent results on the computational complexity of the separability problem, which has been shown to be NP hard, this hierarchy of tests gives a complete and also computationally and theoretically appealing characterization of mixed bipartite entangled states

  7. SPS completes LS1 activities

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    On 27 June, the SPS closed its doors to the LS1 engineers, bringing to an end almost 17 months of activities. The machine now enters the hardware-testing phase in preparation for an October restart.   Photo 1: The SPS transfer tunnel, TT10, reinforced with steal beams. Having completed their LS1 activities right on schedule (to the day!), the SPS team is now preparing the machine for its restart. Over the next eight weeks, hardware tests of the SPS dipole and quadrupole power converters will be underway, led by the TE-EPC (Electrical Power Converters) team. "OP start-up test activities will also be running in parallel, utilising the off hours when EPC is not using the machine," says David McFarlane, the SPS technical coordinator from the Engineering Department. "The primary beam testing phase will start at the beginning of September, once hardware tests and DSO safety tests have been completed." It has been a long journey to this point, with several major...

  8. AEgIS installation completed

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    Gravity. Despite first being described over three centuries ago, it remains one of the least understood of the fundamental forces explored by physicists. At CERN’s recently completed AEgIS experiment, a team has set out to examine the effect of gravity on an as-yet-uncharted realm: antimatter.   The complete AEgIS set-up. Located in the AD hall, the AEgIS experiment plans to  make the first direct measurement of Earth’s gravitation effect on antimatter. By sending a beam of antihydrogen atoms through very thin gratings, the experiment will be able to measure how far the antihydrogen atoms fall and in how much time – giving the AEgIS team a measurement of the gravitational coupling. “By the end of 2012, we had finished by putting all the elements of the experiment together,” explains Michael Doser, AEgIS Spokesperson. “Now we have to show that they can all work together and, unfortunately, we will have no antiproton beams fo...

  9. Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

    Science.gov (United States)

    Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

    2007-06-01

    Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time.

  10. Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

    International Nuclear Information System (INIS)

    Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

    2007-01-01

    Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time

  11. Mobile code security

    Science.gov (United States)

    Ramalingam, Srikumar

    2001-11-01

    A highly secure mobile agent system is very important for a mobile computing environment. The security issues in mobile agent system comprise protecting mobile hosts from malicious agents, protecting agents from other malicious agents, protecting hosts from other malicious hosts and protecting agents from malicious hosts. Using traditional security mechanisms the first three security problems can be solved. Apart from using trusted hardware, very few approaches exist to protect mobile code from malicious hosts. Some of the approaches to solve this problem are the use of trusted computing, computing with encrypted function, steganography, cryptographic traces, Seal Calculas, etc. This paper focuses on the simulation of some of these existing techniques in the designed mobile language. Some new approaches to solve malicious network problem and agent tampering problem are developed using public key encryption system and steganographic concepts. The approaches are based on encrypting and hiding the partial solutions of the mobile agents. The partial results are stored and the address of the storage is destroyed as the agent moves from one host to another host. This allows only the originator to make use of the partial results. Through these approaches some of the existing problems are solved.

  12. Mobile and contextual learning

    Directory of Open Access Journals (Sweden)

    Agnes Kukulska-Hulme

    2009-12-01

    Full Text Available Is mobile learning just a part of everyday learning? This is a relevant question in an age when most people throughout the world now have access to mobile phones and mobility is increasingly taken for granted. In one sense, mobile learning is no different to carrying a textbook or learning through conversations at home, as part of formal education or in the workplace. The technology may be more engaging, but is the learning any different? Despite the ubiquity of mobile phones, smartphones, mp3 players and, increasingly, access to Wi-Fi connections and GPS navigation, the reasons for using mobile and wireless technologies in education are not yet widely known. There is significant specialist expertise, built from ten years of research (and more recently, reflective practice to demonstrate the unique characteristics of mobile learning, which include orchestrating shared learning with personal devices across formal and informal settings, providing immediately useful information, offering timely revision and reflection, connecting real and virtual locations, and enriching field trips and cultural visits. This knowledge needs to be disseminated and examined from new perspectives.

  13. Displays enabling mobile multimedia

    Science.gov (United States)

    Kimmel, Jyrki

    2007-02-01

    With the rapid advances in telecommunications networks, mobile multimedia delivery to handsets is now a reality. While a truly immersive multimedia experience is still far ahead in the mobile world, significant advances have been made in the constituent audio-visual technologies to make this become possible. One of the critical components in multimedia delivery is the mobile handset display. While such alternatives as headset-style near-to-eye displays, autostereoscopic displays, mini-projectors, and roll-out flexible displays can deliver either a larger virtual screen size than the pocketable dimensions of the mobile device can offer, or an added degree of immersion by adding the illusion of the third dimension in the viewing experience, there are still challenges in the full deployment of such displays in real-life mobile communication terminals. Meanwhile, direct-view display technologies have developed steadily, and can provide a development platform for an even better viewing experience for multimedia in the near future. The paper presents an overview of the mobile display technology space with an emphasis on the advances and potential in developing direct-view displays further to meet the goal of enabling multimedia in the mobile domain.

  14. Editorial: Mobile (March 2010

    Directory of Open Access Journals (Sweden)

    Thomas Kunz

    2010-02-01

    Full Text Available Open source software and hardware has become an accepted way of developing new and interesting applications in many information and communication technology domains: operating systems, databases, Web infrastructure, and applications. It's not surprising that with the increasing popularity of mobile handheld devices, users and researchers have explored the power of open approaches to providing innovative new applications and services in this domain. However, unlike personal computers and the Internet, mobile handsets were tightly controlled by mobile network operators (MNOs who developed a vertical ecosystem by integrating the communication infrastructure, the handheld device hardware, and often the applications installed on those devices. The software and protocols running the mobile communications infrastructure and devices are often standardized by membership-only bodies, where large MNOs and manufacturers have a predominant influence. These players invest significant financial resources into shaping the industry along their vision to gain a competitive advantage. A current example is the ongoing battle about the dominant radio access technology for 4G cellular systems: LTE vs. Wimax. These trends have changed recently. Companies such as Google, Nokia, or Openmoko and Industry Alliances such as the Open Handset Alliance are providing the core building blocks, both in hardware as well as software, of increasingly open mobile devices. This issue of the OSBR reviews the relevant trends in the open mobile platform space from a number of perspectives. As the articles in these issue show, there is a lot of exciting ongoing work that brings the power of open source development to the mobile space. This trend is not just confined to the mobile devices as there are also efforts in the development of open mobile infrastructure elements and whole systems.

  15. Evaluating Teleworkers' Acceptance of Mobile Technology: A Study Based on the Utaut Model

    Science.gov (United States)

    Mills, Jamia Sharie

    2016-01-01

    Mobile technology has provided flexible methods for employees to complete work-related tasks without being tied to an office. Research has predicted the level of training on mobile technology may impact a user's ability to complete work responsibilities accurately. This study intended to examine what behavior factors from the unified theory of…

  16. Design and development of the mobile game based on the J2ME technology

    Science.gov (United States)

    He, JunHua

    2012-01-01

    With the continuous improvement of mobile performance, mobile entertainment applications market trend has been increasingly clear, mobile entertainment applications will be after the PC entertainment applications is another important business growth. Through the full analysis of the current mobile entertainment applications market demand and trends, the author has accumulated a lot of theoretical knowledge and practical experience. Rational, using of some new technology for a mobile entertainment games design, and described the development of key technologies required for mobile game an analysis and design of the game, and to achieve a complete game development. Light of the specific mobile game project - "Battle City", detailed the development of a mobile game based on the J2ME platform, the basic steps and the various key elements, focusing on how to use object-oriented thinking on the role of mobile phones in the abstract and Game Animation package, the source code with specific instructions.

  17. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja

    2006-01-01

    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  18. Mobile communication and intermediality

    DEFF Research Database (Denmark)

    Helles, Rasmus

    2013-01-01

    communicative affordances of mobile devices in order to understand how people choose between them for different purposes. It is argued that mobile communication makes intermediality especially central, as the choice of medium is detached from the location of stationary media and begins to follow the user across......The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...

  19. The Cognitive Mobilization Index

    Directory of Open Access Journals (Sweden)

    Antonio Alaminos

    2012-01-01

    Full Text Available This article shows how the cognitive mobilization index, designed for use in observing potential political participation, can be used as an indicator of the political climate that a particular society is going through. Following a discussion of the theoretical elaborations (and their working definitions of the concept of cognitive mobilization, a longitudinal study of various European countries is used to consider the question of how political crises influence cognitive mobilization indexes and what effects they have on the political socialization process among the youngest cohorts.

  20. MOBILE GAME HALMA MULTIPLAYER

    Directory of Open Access Journals (Sweden)

    Muhammad Dhimas

    2015-04-01

    Full Text Available Handphone besides as a communication tool also has a function as a medium of entertainment. Various multimedia services and communications facilities contained therein, one Bluetooth. Games is one application that always exist in the mobile phone, and with a wider variety of games development by utilizing the services in mobile. In this research, the development of the multiplayer games for mobile phones utilizing Bluetooth communication media using the programming language Java Micro Edition (J2ME. Design method using the grapple, NetBeans IDE 6.1 is used as tools to assist programming.