WorldWideScience

Sample records for twilight-active firefly photinus

  1. Flash signal evolution in Photinus fireflies: character displacement and signal exploitation in a visual communication system.

    Science.gov (United States)

    Stanger-Hall, Kathrin F; Lloyd, James E

    2015-03-01

    Animal communication is an intriguing topic in evolutionary biology. In this comprehensive study of visual signal evolution, we used a phylogenetic approach to study the evolution of the flash communication system of North American fireflies. The North American firefly genus Photinus contains 35 described species with simple ON-OFF visual signals, and information on habitat types, sympatric congeners, and predators. This makes them an ideal study system to test hypotheses on the evolution of male and female visual signal traits. Our analysis of 34 Photinus species suggests two temporal pattern generators: one for flash duration and one for flash intervals. Reproductive character displacement was a main factor for signal divergence in male flash duration among sympatric Photinus species. Male flash pattern intervals (i.e., the duration of the dark periods between signals) were positively correlated with the number of sympatric Photuris fireflies, which include predators of Photinus. Females of different Photinus species differ in their response preferences to male traits. As in other communication systems, firefly male sexual signals seem to be a compromise between optimizing mating success (sexual selection) and minimizing predation risk (natural selection). An integrative model for Photinus signal evolution is proposed.

  2. Preparation of recombinant firefly luciferase by a simple and rapid expression and purification method and its application in bacterial detection

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A simple and rapid expression and purification method of recombinant firefly luciferase was developed for bacteria detection. A modified luciferase gene from North American firefly Photinus pyralis was cloned into pET28a expression vector and the recombinant protein was produced in Escherichia coli BL21. The recombinant luciferase,equipped with a polyhistidine affinity tag,was purified by immobilized metal ion affinity chromatography (IMAC). The approach generated an abundant expression and an efficient pur...

  3. Cloning of the Orange Light-Producing Luciferase from Photinus scintillans-A New Proposal on how Bioluminescence Color is Determined.

    Science.gov (United States)

    Branchini, Bruce R; Southworth, Tara L; Fontaine, Danielle M; Murtiashaw, Martha H; McGurk, Alex; Talukder, Munya H; Qureshi, Rakhshi; Yetil, Deniz; Sundlov, Jesse A; Gulick, Andrew M

    2017-03-01

    Unlike the enchanting yellow-green flashes of light produced on warm summer evenings by Photinus pyralis, the most common firefly species in North America, the orange lights of Photinus scintillans are infrequently observed. These Photinus species, and likely all bioluminescent beetles, use the same substrates beetle luciferin, ATP and oxygen to produce light. It is the structure of the particular luciferase enzyme that is the key to determining the color of the emitted light. We report here the molecular cloning of the P. scintillans luc gene and the expression and characterization of the corresponding novel recombinant luciferase enzyme. A comparison of the amino acid sequence with that of the highly similar P. pyralis enzyme and subsequent mutagenesis studies revealed that the single conservative amino acid change tyrosine to phenylalanine at position 255 accounted for the entire emission color difference. Additional mutagenesis and crystallographic studies were performed on a H-bond network, which includes the position 255 residue and five other stringently conserved beetle luciferase residues, that is proximal to the substrate/emitter binding site. The results are interpreted in the context of a speculative proposal that this network is key to the understanding of bioluminescence color determination. © 2016 The American Society of Photobiology.

  4. Near infrared bioluminescence resonance energy transfer from firefly luciferase—quantum dot bionanoconjugates

    Science.gov (United States)

    Alam, Rabeka; Karam, Liliana M.; Doane, Tennyson L.; Zylstra, Joshua; Fontaine, Danielle M.; Branchini, Bruce R.; Maye, Mathew M.

    2014-12-01

    The bioluminescence resonance energy transfer (BRET) between firefly luciferase enzymes and semiconductive quantum dots (QDs) with near infrared emission is described. The QD were phase transferred to aqueous buffers using a histidine mediated phase transfer route, and incubated with a hexahistidine tagged, green emitting variant of firefly luciferase from Photinus pyralis (PPyGRTS). The PPyGRTS were bound to the QD interface via the hexahistidine tag, which effectively displaces the histidine layer and binds directly to the QD interfaces, allowing for short donor-acceptor distances (˜5.5 nm). Due to this, high BRET efficiency ratios of ˜5 were obtained. These PPyGRTS-QD bio-nano conjugates were characterized by transmission electron microscopy, thermal gravimetric analysis, Fourier transform infrared spectroscopy and BRET emission studies. The final optimized conjugate was easily observable by night vision imaging, demonstrating the potential of these materials in imaging and signaling/sensing applications.

  5. Dragonflies and Fireflies

    Science.gov (United States)

    Mannlein, Sally

    2009-01-01

    Most first-graders are interested in insects. In this article, the author describes a lesson, "Dragonflies and Fireflies," which is a first-grade lesson showing drawing, symmetry, neighboring colors (analogous) and watercolor techniques.

  6. A transgenic rat with ubiquitous expression of firefly luciferase gene

    Science.gov (United States)

    Hakamata, Yoji; Murakami, Takashi; Kobayashi, Eiji

    2006-02-01

    In vivo imaging strategies provide cellular and molecular events in real time that helps us to understand biological processes in living animals. The development of molecular tags such as green fluorescent proteins and luciferase from the firefly Photinus pyralis has lead to a revolution in the visualization of complex biochemical processes. We developed a novel inbred transgenic rat strain containing firefly luciferase based on the transgenic (Tg) technique in rats. This Tg rat expressed the luciferase gene ubiquitously under control of the ROSA26 promoter. Cellular immune responsiveness against the luciferase protein was evaluated using conventional skin grafting and resulted in the long-term acceptance of Tg rat skin on wild-type rats. Strikingly, organ transplant with heart and small bowel demonstrated organ viability and graft survival, suggesting that cells from luciferase-Tg are transplantable to track their fate. Taking advantage of the less immunogenic luciferase, we also tested the role of hepatocyte-infusion in a liver injury model, and bone marrow-derived cells in a skin defect model. Employed in conjunction with modern advances in optical imaging, this luciferase-Tg rat system provides an innovative animal tool and a new means of facilitating biomedical research such as in the case of regeneration medicine.

  7. A New Modified Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Medha Gupta

    2016-07-01

    Full Text Available Nature inspired meta-heuristic algorithms studies the emergent collective intelligence of groups of simple agents. Firefly Algorithm is one of the new such swarm-based metaheuristic algorithm inspired by the flashing behavior of fireflies. The algorithm was first proposed in 2008 and since then has been successfully used for solving various optimization problems. In this work, we intend to propose a new modified version of Firefly algorithm (MoFA and later its performance is compared with the standard firefly algorithm along with various other meta-heuristic algorithms. Numerical studies and results demonstrate that the proposed algorithm is superior to existing algorithms.

  8. IPAC Firefly Development Roadmap

    OpenAIRE

    Wu, Xiuqin

    2015-01-01

    IPAC Firefly package has been developed in IRSA (NASA/IPAC Infrared Science Archive) in last six years. It is a software package utilizing state-of-the art AJAX technology to provide an interactive web user interface for astronomers. It has been used to build Spitzer Heritage Archive, WISE Image Service, Planck Visualization, PTF Image Service, and the new IRSA finder chart. It provides three major components: table display, FITS images visualization, and 2D plot. All three highly interactive...

  9. Robust red-emission spectra and yields in firefly bioluminescence against temperature changes

    Science.gov (United States)

    Mochizuki, Toshimitsu; Wang, Yu; Hiyama, Miyabi; Akiyama, Hidefumi

    2014-05-01

    We measured the quantitative spectra of firefly (Photinus pyralis) bioluminescence at various temperatures to investigate the temperature dependence of the luciferin-luciferase reaction at 15-34 °C. The quantitative spectra were decomposed very well into red (1.9 eV), orange (2.0 eV), and green (2.2 eV) Gaussian components. The intensity of the green component was the only temperature sensitive quantity that linearly decreased as the temperature increased at pH 7 and 8. We found the quantitative bioluminescence spectra to be robust below 2.0 eV against temperature and other experimental conditions. The revealed robustness of the red emissions should be useful for quantitative applications such as adenosine-5'-triphosphate detection.

  10. Firefly: embracing future web technologies

    Science.gov (United States)

    Roby, W.; Wu, X.; Goldina, T.; Joliet, E.; Ly, L.; Mi, W.; Wang, C.; Zhang, Lijun; Ciardi, D.; Dubois-Felsmann, G.

    2016-07-01

    At IPAC/Caltech, we have developed the Firefly web archive and visualization system. Used in production for the last eight years in many missions, Firefly gives the scientist significant capabilities to study data. Firefly provided the first completely web based FITS viewer as well as a growing set of tabular and plotting visualizers. Further, it will be used for the science user interface of the LSST telescope which goes online in 2021. Firefly must meet the needs of archive access and visualization for the 2021 LSST telescope and must serve astronomers beyond the year 2030. Recently, our team has faced the fact that the technology behind Firefly software was becoming obsolete. We were searching for ways to utilize the current breakthroughs in maintaining stability, testability, speed, and reliability of large web applications, which Firefly exemplifies. In the last year, we have ported the Firefly to cutting edge web technologies. Embarking on this massive overhaul is no small feat to say the least. Choosing the technologies that will maintain a forward trajectory in a future development project is always hard and often overwhelming. When a team must port 150,000 lines of code for a production-level product there is little room to make poor choices. This paper will give an overview of the most modern web technologies and lessons learned in our conversion from GWT based system to React/Redux based system.

  11. A multi-group firefly algorithm for numerical optimization

    Science.gov (United States)

    Tong, Nan; Fu, Qiang; Zhong, Caiming; Wang, Pengjun

    2017-08-01

    To solve the problem of premature convergence of firefly algorithm (FA), this paper analyzes the evolution mechanism of the algorithm, and proposes an improved Firefly algorithm based on modified evolution model and multi-group learning mechanism (IMGFA). A Firefly colony is divided into several subgroups with different model parameters. Within each subgroup, the optimal firefly is responsible for leading the others fireflies to implement the early global evolution, and establish the information mutual system among the fireflies. And then, each firefly achieves local search by following the brighter firefly in its neighbors. At the same time, learning mechanism among the best fireflies in various subgroups to exchange information can help the population to obtain global optimization goals more effectively. Experimental results verify the effectiveness of the proposed algorithm.

  12. IPAC Firefly package goes open source

    Science.gov (United States)

    Wu, Xiuqin; Roby, William; Goldina, Tatiana; Ly, Loi; IRSA IPAC

    2015-01-01

    IPAC Firefly package has been developed in IRSA (NASA/IPAC Infrared Science Archive) in last six years. It is a software package utilizing state-of-the art AJAX technology to provide an interactive web user interface for astronomers. It has been used to build Spitzer Heritage Archive, WISE Image Service, Planck Visualization, PTF Image Service, and the new IRSA finder chart. It provides three major components: table display, FITS images visualization, and 2D plot. All three highly interactive components can work together using the same data model or separately to provide any combinations of interactivities among them. Firefly toolkits provide an easy way to put interactivities in an otherwise static web page. With a few lines of simple JavaScript embebded in a web page, Firefly toolkits can add manipulative functions to a static table, display a FITS image, or draw an XY 2D plot interactively.FIrefly will be in the GItHub soon.

  13. Memetic firefly algorithm for combinatorial optimization

    CERN Document Server

    Fister, Iztok; Fister, Iztok; Brest, Janez

    2012-01-01

    Firefly algorithms belong to modern meta-heuristic algorithms inspired by nature that can be successfully applied to continuous optimization problems. In this paper, we have been applied the firefly algorithm, hybridized with local search heuristic, to combinatorial optimization problems, where we use graph 3-coloring problems as test benchmarks. The results of the proposed memetic firefly algorithm (MFFA) were compared with the results of the Hybrid Evolutionary Algorithm (HEA), Tabucol, and the evolutionary algorithm with SAW method (EA-SAW) by coloring the suite of medium-scaled random graphs (graphs with 500 vertices) generated using the Culberson random graph generator. The results of firefly algorithm were very promising and showed a potential that this algorithm could successfully be applied in near future to the other combinatorial optimization problems as well.

  14. Study of firefly luciferin oxidation and isomerism as possible inhibition pathways for firefly bioluminescence

    Science.gov (United States)

    Pinto da Silva, Luís; Esteves da Silva, Joaquim C. G.

    2014-01-01

    Firefly bioluminescence presents a light emitting profile with a form of a flash, due to the firefly luciferase-catalyzed formation of inhibitory products. These impair the binding of the substrate luciferin to the active site of the enzyme. However, this luciferase catalyzed pathways may not be the only ones responsible for the flash profile. The oxidation and isomerisation of the substrate luciferin lead to the formation of compounds that are also known inhibitors of firefly bioluminescence. So, the objective of this Letter was to analyze if these reactions could be capable of interfering with the bioluminescence reaction.

  15. Modulations in the light of the firefly

    Indian Academy of Sciences (India)

    Anurup Gohain Barua

    2013-03-01

    Continuous light could be produced from the firefly by making it inhale vapours of ethyl acetate. Here we perform such a control experiment on the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae), and analyse the light in the microsecond time scale. The amplitude of the continuous train of triangular pulses is apparently altered in accordance with the instantaneous values of a hypothetical signal, which exhibits pulse amplitude modulation (PAM). In addition to sampling in amplitude, this scheme apparently provides sampling in time, representing pulse width modulation (PWM). A Fourier transform spectrum of this waveform shows the `carrier’ frequency and the accompanying `side bands’.

  16. An enhanced chimeric firefly luciferase-inspired enzyme for ATP detection and bioluminescence reporter and imaging applications.

    Science.gov (United States)

    Branchini, Bruce R; Southworth, Tara L; Fontaine, Danielle M; Kohrt, Dawn; Talukder, Munya; Michelini, Elisa; Cevenini, Luca; Roda, Aldo; Grossel, Martha J

    2015-09-01

    Firefly luciferases, which emit visible light in a highly specific ATP-dependent process, have been adapted for a variety of applications, including gene reporter assays, whole-cell biosensor measurements, and in vivo imaging. We previously reported the approximately 2-fold enhanced activity and 1.4-fold greater bioluminescence quantum yield properties of a chimeric enzyme that contains the N-domain of Photinus pyralis luciferase joined to the C-domain of Luciola italica luciferase. Subsequently, we identified 5 amino acid changes based on L. italica that are the main determinants of the improved bioluminescence properties. Further engineering to enhance thermal and pH stability produced a novel luciferase called PLG2. We present here a systematic comparison of the spectral and physical properties of the new protein with P. pyralis luciferase and demonstrate the potential of PLG2 for use in assays based on the detection of femtomole levels of ATP. In addition, we compared the performance of a mammalian codon-optimized version of the cDNA for PLG2 with the luc2 gene in HEK293T cells. Using an optimized low-cost assay system, PLG2 activity can be monitored in mammalian cell lysates and living cells with 4.4-fold and approximately 3.0-fold greater sensitivity, respectively. PLG2 could be an improved alternative to Promega's luc2 for reporter and imaging applications.

  17. An enhanced chimeric firefly luciferase-inspired enzyme for ATP detection and bioluminescence reporter and imaging applications

    Science.gov (United States)

    Branchini, Bruce R.; Southworth, Tara L.; Fontaine, Danielle M.; Kohrt, Dawn; Talukder, Munya; Michelini, Elisa; Cevenini, Luca; Roda, Aldo; Grossel, Martha J.

    2015-01-01

    Firefly luciferases, which emit visible light in a highly specific ATP-dependent process, have been adapted for a variety of applications including gene reporter assays, whole-cell biosensor measurements and in vivo imaging. We have previously reported the ~2-fold enhanced activity and 1.4-greater bioluminescence quantum yield properties of a chimeric enzyme that contains the N-domain of Photinus pyralis luciferase joined to the C-domain of Luciola italica luciferase. Subsequently, we identified 5 amino acid changes based on L. italica that are the main determinants of the improved bioluminescence properties. Further engineering to enhance thermal and pH stability produced a novel luciferase called PLG2. We present here a systematic comparison of the spectral and physical properties of the new protein with P. pyralis luciferase and demonstrate the potential of PLG2 for use in assays based on the detection of femtomol levels of ATP. Additionally, we compared the performance of a mammalian codon-optimized version of the cDNA for PLG2 with the luc2 gene in HEK293T cells. Using an optimized low-cost assay system, PLG2 activity can be monitored in mammalian cell lysates and in living cells offering an improved alternative to Promega’s luc2 for reporter and imaging applications. PMID:26049097

  18. First lasing, capabilities, and flexibilities of FIREFLY

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, K.W.; Smith, T.I. [Stanford Univ., CA (United States)

    1995-12-31

    FIREFLY is a free electron law that was designed to produce picosecond pulses of light in the range between 15 and 100 microns. It uses an inexpensive electromagnetic wiggler and variable outcoupling to provide maximum flexibility for user experiments. FIREFLY first lased on November 23, 1994, and has now operated from 15 to 65 microns. It has lased in both a traditional undulator configuration and as an optical klystron, and has also lased on the third harmonic between 9 and 11microns. We present measurements, of optical spectral width and pulse width at a range of wavelengths in both configurations. We also compare direct measurements of electron beam extraction, efficiency with observed optical power for fundamental, third harmonic, arid optical klystron operation. We discuss wavelength switching between adjacent peaks in the gain spectrum of an optical klystron, observed for the first time in FIREFLY. Finally, we focus on issues relevant to experimentation with FIREFLY, including continuously variable outcoupling, optical mode quality, and beam handling in the far-infrared.

  19. Identification of paralogous genes of firefly luciferase in the Japanese firefly, Luciola cruciata.

    Science.gov (United States)

    Oba, Yuichi; Sato, Mitsunori; Ohta, Yuichiro; Inouye, Satoshi

    2006-03-01

    Two homologous genes of firefly luciferase, LcLL1 and LcLL2, were cloned from the Japanese firefly Luciola cruciata, and were expressed and characterized. The gene product of LcLL1 had long-chain fatty acyl-CoA synthetic activity, but not luciferase activity. The other gene product of LcLL2 did not show enzymatic activities of acyl-CoA synthetase and luciferase. RT-PCR analysis showed that the transcript of LcLL1 was abundant in larva but very low in adult, while LcLL2 was expressed in both larva and adult. Phylogenetic analysis indicated that LcLL1 and LcLL2 are paralogous genes of firefly luciferase. Recently, we found that CG6178 in Drosophila melanogaster is an orthologue of firefly luciferase and shows fatty acyl-CoA synthetic activity, but not luciferase activity. These results suggest that firefly luciferase might be evolved from a fatty acyl-CoA synthetase by gene duplication in insects.

  20. Multicolor Bioluminescence Obtained Using Firefly Luciferin.

    Science.gov (United States)

    Kiyama, Masahiro; Saito, Ryohei; Iwano, Satoshi; Obata, Rika; Niwa, Haruki; Maki, Shojiro A

    2016-01-01

    Firefly bioluminescence is widely used in life science research as a useful analysis tool. For example, the adenosine-5`-triphosphate (ATP)-dependent enzymatic firefly bioluminescence reaction has long been utilized as a microbial monitoring tool. Rapid and sensitive firefly luciferin-luciferase combinations are used not only to measure cell viability but also for reporter-gene assays. Recently, bioluminescence was utilized as a noninvasive, real-time imaging tool for living subjects to monitor cells and biological events. However, the number of commercialized luciferase genes is limited and tissue-permeable near-infrared (NIR) region emitting light is required for in vivo imaging. In this review, recent studies describing synthetic luciferin analogues predicted to have red-shifted bioluminescence are summarized. Luciferase substrates emitting red, green, and blue light that were designed and developed in our laboratory are presented. The longest emission wavelength of the synthesized luciferin analogues was recorded at 675 nm, which is within the NIR region. This compound is now commercially available as "Aka Lumine®".

  1. Firefly Algorithm for Economic Power Dispatching With Pollutants Emission

    Directory of Open Access Journals (Sweden)

    Latifa DEKHICI

    2012-01-01

    Full Text Available Bio-inspired algorithms become among the most powerful algorithms for optimization. In this paper, we intend to provide one of the recent bio-inspired metaheuristic which is the Firefly Algorithm (FF to optimize power dispatching. For evaluation, we adapt the particle swarm optimization to the problem in the same way as the firefly algorithm. The application is done in an IEEE-14 and on two thermal plant networks. In one of the examples, we neglect power loss and pollutant emissions. The comparison with the particle swarm optimization (PSO, demonstrate the efficiency of firefly algorithm to reach the best cost in less than one second.

  2. Creation of High Efficient Firefly Luciferase

    Science.gov (United States)

    Nakatsu, Toru

    Firefly emits visible yellow-green light. The bioluminescence reaction is carried out by the enzyme luciferase. The bioluminescence of luciferase is widely used as an excellent tool for monitoring gene expression, the measurement of the amount of ATP and in vivo imaging. Recently a study of the cancer metastasis is carried out by in vivo luminescence imaging system, because luminescence imaging is less toxic and more useful for long-term assay than fluorescence imaging by GFP. However the luminescence is much dimmer than fluorescence. Then bioluminescence imaging in living organisms demands the high efficient luciferase which emits near infrared lights or enhances the emission intensity. Here I introduce an idea for creating the high efficient luciferase based on the crystal structure.

  3. Fiber optic biosensor of immobilized firefly luciferase

    Institute of Scientific and Technical Information of China (English)

    蔡谨; 吉鑫松; 等

    2002-01-01

    Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B,The kinetic properties of immobilized luciferase were extensively studied.The Km' for D-luciferin is 11.9umol/L,the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25℃ respectively.A luminescence fiber optic biosensor,making use of immobilized crude luciferase was developed for assay of ATP.The peak light intensity was linear with respect to ATP concentration in range of 10-9-10-5mol/L.A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.

  4. Fiber optic biosensor of immobilized firefly luciferase

    Institute of Scientific and Technical Information of China (English)

    蔡谨; 孟文芳; 吉鑫松

    2002-01-01

    Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. The Km′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25℃ respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10-9-10-5 mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.

  5. User extensibility of the Firefly astronomical visualization software

    Science.gov (United States)

    Dubois-Felsmann, Gregory P.; Goldina, Tatiana; Ly, Loi; Roby, William; Wu, Xiuqin; Zhang, Lijun

    2016-01-01

    We have developed mechanisms for extending the functionality of the open-source Firefly astronomical visualization software with user-supplied code. Firefly is a toolkit for the construction of Web-based applications for visualizing astronomical images and tabular data, with the software distribution also including a basic general-purpose pre-built application. The Firefly tools are the base for NASA's IRSA archive as well as other web applications developed at IPAC.Recent releases include new public APIs allowing the extension of Firefly functionality in various ways. New Javascript APIs allow customization of the interface presented in the browser, including the ability to define buttons for custom actions that can be performed on points, lines, and regions in images. New Python APIs allow the invocation of operations in a Firefly-based application, allowing it to serve as a display engine for FITS images and other astronomical data. In addition, the Firefly web server side has been enhanced with the ability to invoke user-supplied processes that can produce either image or tabular results based on operations on data from the application or external sources. For instance, the user can define an operation to perform source detection on a graphically selected region in an image and return the results for display as a table and/or x-y plot. User processes can be defined in any language supported on the server host; our current efforts have focused on Python. This mechanism has been used to support the integration of Firefly with the LSST project's software stack, with reusable "tasks" from the LSST stack configurable as extensions to Firefly.

  6. Why is firefly oxyluciferin a notoriously labile substance?

    Science.gov (United States)

    Maltsev, Oleg V; Nath, Naba K; Naumov, Panče; Hintermann, Lukas

    2014-01-13

    The chemistry of firefly bioluminescence is important for numerous applications in biochemistry and analytical chemistry. The emitter of this bioluminescent system, firefly oxyluciferin, is difficult to handle. The cause of its lability was clarified while its synthesis was reinvestigated. A side product was identified and characterized by NMR spectroscopy and X-ray crystallography. The reason for the lability of oxyluciferin is now ascribed to autodimerization of the coexisting enol and keto forms in a Mannich-type reaction.

  7. Crystal structure of firefly luciferase throws light on a superfamily of adenylate-forming enzymes

    National Research Council Canada - National Science Library

    Conti, Elena; Franks, Nick P; Brick, Peter

    1996-01-01

    Firefly luciferase is a 62 kDa protein that catalyzes the production of light. In the presence of MgATP and molecular oxygen, the enzyme oxidizes its substrate, firefly luciferin, emitting yellow-green light...

  8. Biosynthesis of firefly luciferin in adult lantern: decarboxylation of L-cysteine is a key step for benzothiazole ring formation in firefly luciferin synthesis.

    Directory of Open Access Journals (Sweden)

    Yuichi Oba

    Full Text Available BACKGROUND: Bioluminescence in fireflies and click beetles is produced by a luciferase-luciferin reaction. The luminescence property and protein structure of firefly luciferase have been investigated, and its cDNA has been used for various assay systems. The chemical structure of firefly luciferin was identified as the D-form in 1963 and studies on the biosynthesis of firefly luciferin began early in the 1970's. Incorporation experiments using (14C-labeled compounds were performed, and cysteine and benzoquinone/hydroquinone were proposed to be biosynthetic component for firefly luciferin. However, there have been no clear conclusions regarding the biosynthetic components of firefly luciferin over 30 years. METHODOLOGY/PRINCIPAL FINDINGS: Incorporation studies were performed by injecting stable isotope-labeled compounds, including L-[U-(13C3]-cysteine, L-[1-(13C]-cysteine, L-[3-(13C]-cysteine, 1,4-[D6]-hydroquinone, and p-[2,3,5,6-D]-benzoquinone, into the adult lantern of the living Japanese firefly Luciola lateralis. After extracting firefly luciferin from the lantern, the incorporation of stable isotope-labeled compounds into firefly luciferin was identified by LC/ESI-TOF-MS. The positions of the stable isotope atoms in firefly luciferin were determined by the mass fragmentation of firefly luciferin. CONCLUSIONS: We demonstrated for the first time that D- and L-firefly luciferins are biosynthesized in the lantern of the adult firefly from two L-cysteine molecules with p-benzoquinone/1,4-hydroquinone, accompanied by the decarboxylation of L-cysteine.

  9. Cuckoo search and firefly algorithm theory and applications

    CERN Document Server

    2014-01-01

    Nature-inspired algorithms such as cuckoo search and firefly algorithm have become popular and widely used in recent years in many applications. These algorithms are flexible, efficient and easy to implement. New progress has been made in the last few years, and it is timely to summarize the latest developments of cuckoo search and firefly algorithm and their diverse applications. This book will review both theoretical studies and applications with detailed algorithm analysis, implementation and case studies so that readers can benefit most from this book.  Application topics are contributed by many leading experts in the field. Topics include cuckoo search, firefly algorithm, algorithm analysis, feature selection, image processing, travelling salesman problem, neural network, GPU optimization, scheduling, queuing, multi-objective manufacturing optimization, semantic web service, shape optimization, and others.   This book can serve as an ideal reference for both graduates and researchers in computer scienc...

  10. Octopamine: presence in firefly lantern suggests a transmitter role.

    Science.gov (United States)

    Robertson, H A; Carlson, A D

    1976-01-01

    The lantern of the adult firefly is innervated by a nerve supply with endings similar to other known monoaminergic nerves. However, catecholamines could not be detected in the nerve endings and noradrenaline and adrenaline were relatively weak agonists in eliciting a flash of light when applied to the lantern in vitro. Firefly lanterns were assayed for octopamine using a sensitive, specific enzymatic assay in which octopamine is enzymatically converted to 3H-synephrine and quantitated by liquid scintillation counting. The presence of substantial amounts (125 ng/g tissue) of octopamine was demonstrated and confirmed by thin layer chromatography. On the basis of this and earlier work, it is suggested that the nerves to the firefly lantern are octopaminergic.

  11. Transient transfection and expression of firefly luciferase in Giardia lamblia.

    OpenAIRE

    1995-01-01

    We have developed a gene transfer system for the protozoan parasite Giardia lamblia. This organism is responsible for many cases of diarrhea worldwide and is considered to be one of the most primitive eukaryotes. Expression of a heterologous gene was detected in this parasite after electroporation with appropriate DNA constructs. We constructed a series of transfection plasmids using flanking sequences of the Giardia glutamate dehydrogenase (GDH) gene to drive expression of the firefly lucife...

  12. Excited-State Dynamics of Oxyluciferin in Firefly Luciferase

    KAUST Repository

    Snellenburg, Joris J.

    2016-11-23

    The color variations of light emitted by some natural and mutant luciferases are normally attributed to collective factors referred to as microenvironment effects; however, the exact nature of these interactions between the emitting molecule (oxyluciferin) and the active site remains elusive. Although model studies of noncomplexed oxyluciferin and its variants have greatly advanced the understanding of its photochemistry, extrapolation of the conclusions to the real system requires assumptions about the polarity and proticity of the active site. To decipher the intricate excited-state dynamics, global and target analysis is performed here for the first time on the steady-state and time-resolved spectra of firefly oxyluciferin complexed with luciferase from the Japanese firefly (Luciola cruciata). The experimental steady-state and time resolved luminescence spectra of the oxyluciferin/luciferase complex in solution are compared with the broadband time-resolved firefly bioluminescence recorded in vivo. The results demonstrate that de-excitation of the luminophore results in a complex cascade of photoinduced proton transfer processes and can be interpreted by the pH dependence of the emitted light. It is confirmed that proton transfer is the central event in the spectrochemistry of this system for which any assignment of the pH dependent emission to a single chemical species would be an oversimplification.

  13. Bouc–Wen hysteresis model identification using Modified Firefly Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Zaman, Mohammad Asif, E-mail: zaman@stanford.edu [Department of Electrical Engineering, Stanford University (United States); Sikder, Urmita [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley (United States)

    2015-12-01

    The parameters of Bouc–Wen hysteresis model are identified using a Modified Firefly Algorithm. The proposed algorithm uses dynamic process control parameters to improve its performance. The algorithm is used to find the model parameter values that results in the least amount of error between a set of given data points and points obtained from the Bouc–Wen model. The performance of the algorithm is compared with the performance of conventional Firefly Algorithm, Genetic Algorithm and Differential Evolution algorithm in terms of convergence rate and accuracy. Compared to the other three optimization algorithms, the proposed algorithm is found to have good convergence rate with high degree of accuracy in identifying Bouc–Wen model parameters. Finally, the proposed method is used to find the Bouc–Wen model parameters from experimental data. The obtained model is found to be in good agreement with measured data. - Highlights: • We describe a new method to find the Bouc–Wen hysteresis model parameters. • We propose a Modified Firefly Algorithm. • We compare our method with existing methods to find that the proposed method performs better. • We use our model to fit experimental results. Good agreement is found.

  14. Application of firefly algorithm to the dynamic model updating problem

    Science.gov (United States)

    Shabbir, Faisal; Omenzetter, Piotr

    2015-04-01

    Model updating can be considered as a branch of optimization problems in which calibration of the finite element (FE) model is undertaken by comparing the modal properties of the actual structure with these of the FE predictions. The attainment of a global solution in a multi dimensional search space is a challenging problem. The nature-inspired algorithms have gained increasing attention in the previous decade for solving such complex optimization problems. This study applies the novel Firefly Algorithm (FA), a global optimization search technique, to a dynamic model updating problem. This is to the authors' best knowledge the first time FA is applied to model updating. The working of FA is inspired by the flashing characteristics of fireflies. Each firefly represents a randomly generated solution which is assigned brightness according to the value of the objective function. The physical structure under consideration is a full scale cable stayed pedestrian bridge with composite bridge deck. Data from dynamic testing of the bridge was used to correlate and update the initial model by using FA. The algorithm aimed at minimizing the difference between the natural frequencies and mode shapes of the structure. The performance of the algorithm is analyzed in finding the optimal solution in a multi dimensional search space. The paper concludes with an investigation of the efficacy of the algorithm in obtaining a reference finite element model which correctly represents the as-built original structure.

  15. Assessment of environmental factors that affect the fireflies for ecotourism in Unesco Tasik Chini biosphere reserve

    Science.gov (United States)

    Roslan, Norzeana; Sulaiman, Norela

    2015-09-01

    This study was conducted to study the firefly species found in Tasik Chini, the soil factors that suitable for larval development fireflies flashes, and the sociological aspects of the community's availability to engage in firefly ecotourism. This was achieved through firefly sampling, soil analysis, abiotic data collection and by questionnaire surveys from local community perceptions and knowledge on fireflies and ecotourism. Fireflies sampling were conducted from December 2011 to January 2013 at Kampung Melai and Kampung Cenahan. Three non-synchronize fireflies genus were found, namely Colophotia sp., Pygoluciola sp., and Pyrocoelia sp. A total of 25 questionnaires were given to four groups of respondents consisting orang asli (5 respondents), boat operator (2 respondents), resort workers (5 respondents) and FELDA residents (13 respondents). The questionnaires were analysed using Rasch Winstep Software based on Rasch Measurement Model. Results of the survey indicated that the local community was not ready for ecotourism in their area. Meanwhile, the soil pH was very acidic and the heavy metals concentration was high, which is not good for the development of firefly larvae. In conclusion, Tasik Chini was not having the potential for ecotourism. Despite the fact, improvement of soils with soil remediation methods can be apply for enhancing larvae development and having more awareness campaign of ecotourism to local community.

  16. Building Twilight "Light Sensors" to Study the Effects of Light Pollution on Fireflies

    Science.gov (United States)

    Thancharoen, Anchana; Branham, Marc A.; Lloyd, James E.

    2008-01-01

    Light pollution negatively affects many nocturnal organisms. We outline two experiments that can be conducted by students to examine the effects of light pollution on firefly behavior. Inexpensive electronic light sensors, which are easy to construct and calibrate, are used to sample light levels along transects in spaces where fireflies are…

  17. Search for an optimal light-extracting surface derived from the morphology of a firefly lantern

    Science.gov (United States)

    Bay, Annick; Sarrazin, Michaël; Vigneron, Jean Pol

    2013-02-01

    Fireflies light up our warm summer evenings. There is more physics behind these little animals than any one of us could imagine. We analyze from a physical point of view one structure found on the firefly lantern, the one which best improves light extraction. Moreover, simulations will be done to show why this specific structure may be more effective than one designed by humans.

  18. Performance evaluation of firefly algorithm with variation in sorting for non-linear benchmark problems

    Science.gov (United States)

    Umbarkar, A. J.; Balande, U. T.; Seth, P. D.

    2017-06-01

    The field of nature inspired computing and optimization techniques have evolved to solve difficult optimization problems in diverse fields of engineering, science and technology. The firefly attraction process is mimicked in the algorithm for solving optimization problems. In Firefly Algorithm (FA) sorting of fireflies is done by using sorting algorithm. The original FA is proposed with bubble sort for ranking the fireflies. In this paper, the quick sort replaces bubble sort to decrease the time complexity of FA. The dataset used is unconstrained benchmark functions from CEC 2005 [22]. The comparison of FA using bubble sort and FA using quick sort is performed with respect to best, worst, mean, standard deviation, number of comparisons and execution time. The experimental result shows that FA using quick sort requires less number of comparisons but requires more execution time. The increased number of fireflies helps to converge into optimal solution whereas by varying dimension for algorithm performed better at a lower dimension than higher dimension.

  19. Reliable Mobile Ad-Hoc Network Routing Using Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    D Jinil Persis

    2016-05-01

    Full Text Available Routing in Mobile Ad-hoc NETwork (MANET is a contemporary graph problem that is solved using various shortest path search techniques. The routing algorithms employed in modern routers use deterministic algorithms that extract an exact non-dominated set of solutions from the search space. The search efficiency of these algorithms is found to have an exponential time complexity in the worst case. Moreover this problem is a multi-objective optimization problem in nature for MANET and it is required to consider changing topology layout. This study attempts to employ a formulation incorporating objectives viz., delay, hop-distance, load, cost and reliability that has significant impact on network performance. Simulation with different random topologies has been carried out to illustrate the implementation of an exhaustive search algorithm and it is observed that the algorithm could handle small-scale networks limited to 15 nodes. A random search meta-heuristic that adopts the nature of firefly swarm has been proposed for larger networks to yield an approximated non-dominated path set. Firefly Algorithm is found to perform better than the exact algorithm in terms of scalability and computational time.

  20. Accretion stream mapping with genetically modified "fire-flies"

    CERN Document Server

    Bridge, C M; Cropper, M; Ramsay, G

    2004-01-01

    We apply an eclipse mapping technique using `genetically modified fire-flies' to the eclipse light curves of HU Aqr and EP Dra. The technique makes as few assumptions as possible about the location of accretion stream material, allowing the emission to be located anywhere within the Roche lobe of the white dwarf. We model two consecutive eclipses in the UBVR_c band for HU Aqr, and four consecutive `white'-light eclipses for EP Dra, to determine the changing brightness distribution of stream material. We find fire-fly distributions which are consistent with accretion through a curtain of material in both HU Aqr and EP Dra, and show that the previously assumed two part ballistic and magnetic trajectory is a good approximation for polars. Model fits to the colour band data of HU Aqr indicate that the material confined to the magnetic field lines is brightest, and most of the emission originates from close to the white dwarf. There is evidence for emission from close to a calculated ballistic stream in both HU Aq...

  1. Biologically inspired LED lens from cuticular nanostructures of firefly lantern.

    Science.gov (United States)

    Kim, Jae-Jun; Lee, Youngseop; Kim, Ha Gon; Choi, Ki-Ju; Kweon, Hee-Seok; Park, Seongchong; Jeong, Ki-Hun

    2012-11-13

    Cuticular nanostructures found in insects effectively manage light for light polarization, structural color, or optical index matching within an ultrathin natural scale. These nanostructures are mainly dedicated to manage incoming light and recently inspired many imaging and display applications. A bioluminescent organ, such as a firefly lantern, helps to out-couple light from the body in a highly efficient fashion for delivering strong optical signals in sexual communication. However, the cuticular nanostructures, except the light-producing reactions, have not been well investigated for physical principles and engineering biomimetics. Here we report a unique observation of high-transmission nanostructures on a firefly lantern and its biological inspiration for highly efficient LED illumination. Both numerical and experimental results clearly reveal high transmission through the nanostructures inspired from the lantern cuticle. The nanostructures on an LED lens surface were fabricated by using a large-area nanotemplating and reconfigurable nanomolding with heat-induced shear thinning. The biologically inspired LED lens, distinct from a smooth surface lens, substantially increases light transmission over visible ranges, comparable to conventional antireflection coating. This biological inspiration can offer new opportunities for increasing the light extraction efficiency of high-power LED packages.

  2. Theoretical tuning of the firefly bioluminescence spectra by the modification of oxyluciferin

    Science.gov (United States)

    Cheng, Yuan-Yuan; Zhu, Jia; Liu, Ya-Jun

    2014-01-01

    Extending the firefly bioluminescence is of practical significance for the improved visualization of living cells and the development of a multicolor reporter. Tuning the color of bioluminescence in fireflies mainly involves the modification of luciferase and luciferin. In this Letter, we theoretically studied the emission spectra of 9 firefly oxyluciferin analogs in the gas phase and in solutions. Three density functionals, including B3LYP, CAM-B3LYP and M06-2X, were employed to theoretically predict the efficiently luminescent analogs. The reliable functionals for calculating the targeted systems were suggested. The luminescence efficiency, solvent effects, and substituent effects are discussed based on the calculated results.

  3. The light of the firefly under the influence of ethyl acetate

    Indian Academy of Sciences (India)

    Anurup Gohain Barua; Subhash Rajbongshi

    2010-06-01

    When a firefly is made to inhale ethyl acetate vapour, a constant glow appears after a few minutes from its abdominal lantern. This control experiment has been performed by a few workers to record the emission spectrum of the firefly. However, a time-resolved experiment performed by us on this continuous light emitted by the species Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) reveals that it is composed of a continuous train of tiny pulses! The nature of the pulses suggests that an oscillatory chemical reaction continues in the microsecond time scale in the lantern of the anaesthetized firefly.

  4. Bioinspired photonic structures by the reflector layer of firefly lantern for highly efficient chemiluminescence

    Science.gov (United States)

    Chen, Linfeng; Shi, Xiaodi; Li, Mingzhu; Hu, Junping; Sun, Shufeng; Su, Bin; Wen, Yongqiang; Han, Dong; Jiang, Lei; Song, Yanlin

    2015-08-01

    Fireflies have drawn considerable attention for thousands of years due to their highly efficient bioluminescence, which is important for fundamental research and photonic applications. However, there are few reports on the reflector layer (RL) of firefly lantern, which contributes to the bright luminescence. Here we presented the detailed microstructure of the RL consisting of random hollow granules, which had high reflectance in the range from 450 nm to 800 nm. Inspired by the firefly lantern, artificial films with high reflectance in the visible region were fabricated using hollow silica microparticles mimicking the structure of the RL. Additionally, the bioinspired structures provided an efficient RL for the chemiluminescence system and could substantially enhance the initial chemiluminescence intensity. The work not only provides new insight into the bright bioluminescence of fireflies, but also is importance for the design of photonic materials for theranostics, detection, and imaging.

  5. Effect of very high magnetic field on the optical properties of firefly light emitter oxyluciferin

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Weihang; Nakamura, Daisuke [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Wang, Yu [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences (China); Mochizuki, Toshimitsu [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, 2-2-9 Machiike-dai, Koriyama, Fukushima 963-0215 (Japan); Akiyama, Hidefumi [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Takeyama, Shojiro, E-mail: takeyama@issp.u-tokyo.ac.jp [Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan)

    2015-09-15

    Magnetic field effect on enzymatic reactions is under intensive study in the past decades. Recently, it was reported that firefly bioluminescence was suppressed and red-shifted significantly when exposed to external magnetic field. However in this work, by means of selective excitation, we confirmed that emission properties of firefly light emitter “oxyluciferin” are completely immune to external magnetic field of up to 53 T. These findings pose strong contrast to existing relevant results. Potential reasons for the discrepancies found and the underlying physics towards the understanding of firefly bioluminescence were discussed. - Highlights: • Effect of ultra-high magnetic field on the optical properties of firefly light emitter oxyluciferin was reported. • Emission properties of oxyluciferin were confirmed to be immune to external high magnetic fields up to 53 T. • .Potential reasons for the discrepancies between our results and previous reports and the underlying physics were discussed.

  6. Excited-state proton transfer of firefly dehydroluciferin.

    Science.gov (United States)

    Presiado, Itay; Erez, Yuval; Simkovitch, Ron; Shomer, Shay; Gepshtein, Rinat; Pinto da Silva, Luís; Esteves da Silva, Joaquim C G; Huppert, Dan

    2012-11-08

    Steady-state and time-resolved emission techniques were used to study the protolytic processes in the excited state of dehydroluciferin, a nonbioluminescent product of the firefly enzyme luciferase. We found that the ESPT rate coefficient is only 1.1 × 10(10) s(-1), whereas those of d-luciferin and oxyluciferin are 3.7 × 10(10) and 2.1 × 10(10) s(-1), respectively. We measured the ESPT rate in water-methanol mixtures, and we found that the rate decreases nonlinearly as the methanol content in the mixture increases. The deprotonated form of dehydroluciferin has a bimodal decay with short- and long-time decay components, as was previously found for both D-luciferin and oxyluciferin. In weakly acidic aqueous solutions, the deprotonated form's emission is efficiently quenched. We attribute this observation to the ground-state protonation of the thiazole nitrogen, whose pK(a) value is ~3.

  7. Preparation and epitope characterization of monoclonal antibodies against firefly luciferase

    Institute of Scientific and Technical Information of China (English)

    徐沁; 丁建芳; 胡红雨; 许根俊

    1999-01-01

    The 6-His tagged firefly luciferase was highly expressed in E. coli and purified to homogeneity by affinity chromatography and gel filtration. After immunizing Balb/c mice with the antigen, 6 hybridomas clones were found to secrete monoelonal antibodies (mAbs) and the mAbs were also purified separately. The competitive binding experiments show that 2 mAbs can bind heat-denatured antigen or its proteolytic fragments but not the native lueiferase, suggesting that their epitopes might be accommodated in the internal segments of the protein. On the other hand, the other 4 mAbs are capable of binding both native and denatured antigens. It infers that their epitopes locate in the segments on the protein surface. The results also suggest that the six mAbs are all sequence-specific.

  8. A LOAD BALANCING MODEL USING FIREFLY ALGORITHM IN CLOUD COMPUTING

    Directory of Open Access Journals (Sweden)

    A. Paulin Florence

    2014-01-01

    Full Text Available Cloud computing is a model that points at streamlining the on-demand provisioning of software, hardware and data as services and providing end-users with flexible and scalable services accessible through the Internet. The main objective of the proposed approach is to maximize the resource utilization and provide a good balanced load among all the resources in cloud servers. Initially, a load model of every resource will be derived based on several factors such as, memory usage, processing time and access rate. Based on the newly derived load index, the current load will be computed for all the resources shared in virtual machine of cloud servers. Once the load index is computed for all the resources, load balancing operation will be initiated to effectively use the resources dynamically with the process of assigning resources to the corresponding node to reduce the load value. So, assigning of resources to proper nodes is an optimal distribution problem so that many optimization algorithms such as genetic algorithm and modified genetic algorithm are utilized for load balancing. These algorithms are not much effective in providing the neighbour solutions since it does not overcome exploration and exploration problem. So, utilizing the effective optimization procedure instead of genetic algorithm can lead to better load balancing since it is a traditional and old algorithm. Accordingly, I have planned to utilize a recent optimization algorithm, called firefly algorithm to do the load balancing operation in our proposed work. At first, the index table will be maintained by considering the availability of virtual servers and sequence of request. Then, load index will be computed based on the newly derived formulae. Based on load index, load balancing operation will be carried out using firefly algorithm. The performance analysis produced expected results and thus proved the proposed approach is efficient in optimizing schedules by balancing the

  9. Continuous firefly algorithm applied to PWR core pattern enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Poursalehi, N., E-mail: npsalehi@yahoo.com [Engineering Department, Shahid Beheshti University, G.C., P.O. Box 1983963113, Tehran (Iran, Islamic Republic of); Zolfaghari, A.; Minuchehr, A.; Moghaddam, H.K. [Engineering Department, Shahid Beheshti University, G.C., P.O. Box 1983963113, Tehran (Iran, Islamic Republic of)

    2013-05-15

    Highlights: ► Numerical results indicate the reliability of CFA for the nuclear reactor LPO. ► The major advantages of CFA are its light computational cost and fast convergence. ► Our experiments demonstrate the ability of CFA to obtain the near optimal loading pattern. -- Abstract: In this research, the new meta-heuristic optimization strategy, firefly algorithm, is developed for the nuclear reactor loading pattern optimization problem. Two main goals in reactor core fuel management optimization are maximizing the core multiplication factor (K{sub eff}) in order to extract the maximum cycle energy and minimizing the power peaking factor due to safety constraints. In this work, we define a multi-objective fitness function according to above goals for the core fuel arrangement enhancement. In order to evaluate and demonstrate the ability of continuous firefly algorithm (CFA) to find the near optimal loading pattern, we developed CFA nodal expansion code (CFANEC) for the fuel management operation. This code consists of two main modules including CFA optimization program and a developed core analysis code implementing nodal expansion method to calculate with coarse meshes by dimensions of fuel assemblies. At first, CFA is applied for the Foxholes test case with continuous variables in order to validate CFA and then for KWU PWR using a decoding strategy for discrete variables. Results indicate the efficiency and relatively fast convergence of CFA in obtaining near optimal loading pattern with respect to considered fitness function. At last, our experience with the CFA confirms that the CFA is easy to implement and reliable.

  10. Firefly Algorithm for Cardinality Constrained Mean-Variance Portfolio Optimization Problem with Entropy Diversity Constraint

    Directory of Open Access Journals (Sweden)

    Nebojsa Bacanin

    2014-01-01

    portfolio model with entropy constraint. Firefly algorithm is one of the latest, very successful swarm intelligence algorithm; however, it exhibits some deficiencies when applied to constrained problems. To overcome lack of exploration power during early iterations, we modified the algorithm and tested it on standard portfolio benchmark data sets used in the literature. Our proposed modified firefly algorithm proved to be better than other state-of-the-art algorithms, while introduction of entropy diversity constraint further improved results.

  11. Search for an optimal light-extracting surface derived from the morphology of a firefly lantern

    CERN Document Server

    Bay, Annick; Vigneron, Jean Pol

    2012-01-01

    Fireflies lighten up our warm summer evenings. There is more physic behind these little animals than anyone of us could imagine. In this paper we analyze from a physical point of view one structure found on the firefly lantern, the one which best improves light extraction. Moreover, simulations will be done to show why this specific structure may be more effective than a "human-thought" one.

  12. An Improved Technique Based on Firefly Algorithm to Estimate the Parameters of the Photovoltaic Model

    Directory of Open Access Journals (Sweden)

    Issa Ahmed Abed

    2016-12-01

    Full Text Available This paper present a method to enhance the firefly algorithm by coupling with a local search. The constructed technique is applied to identify the solar parameters model where the method has been proved its ability to obtain the photovoltaic parameters model. Standard firefly algorithm (FA, electromagnetism-like (EM algorithm, and electromagnetism-like without local (EMW search algorithm all are compared with the suggested method to test its capability to solve this model.

  13. One-pot non-enzymatic formation of firefly luciferin in a neutral buffer from p-benzoquinone and cysteine.

    Science.gov (United States)

    Kanie, Shusei; Nishikawa, Toshio; Ojika, Makoto; Oba, Yuichi

    2016-04-21

    Firefly luciferin, the substrate for the bioluminescence reaction of luminous beetles, possesses a benzothiazole ring, which is rare in nature. Here, we demonstrate a novel one-pot reaction to give firefly luciferin in a neutral buffer from p-benzoquinone and cysteine without any synthetic reagents or enzymes. The formation of firefly luciferin was low in yield in various neutral buffers, whereas it was inhibited or completely prevented in acidic or basic buffers, in organic solvents, or under a nitrogen atmosphere. Labelling analysis of the firefly luciferin using stable isotopic cysteines showed that the benzothiazole ring was formed via the decarboxylation and carbon-sulfur bond rearrangement of cysteine. These findings imply that the biosynthesis of firefly luciferin can be developed/evolved from the non-enzymatic production of firefly luciferin using common primary biosynthetic units, p-benzoquinone and cysteine.

  14. Selection of parameters for advanced machining processes using firefly algorithm

    Directory of Open Access Journals (Sweden)

    Rajkamal Shukla

    2017-02-01

    Full Text Available Advanced machining processes (AMPs are widely utilized in industries for machining complex geometries and intricate profiles. In this paper, two significant processes such as electric discharge machining (EDM and abrasive water jet machining (AWJM are considered to get the optimum values of responses for the given range of process parameters. The firefly algorithm (FA is attempted to the considered processes to obtain optimized parameters and the results obtained are compared with the results given by previous researchers. The variation of process parameters with respect to the responses are plotted to confirm the optimum results obtained using FA. In EDM process, the performance parameter “MRR” is increased from 159.70 gm/min to 181.6723 gm/min, while “Ra” and “REWR” are decreased from 6.21 μm to 3.6767 μm and 6.21% to 6.324 × 10−5% respectively. In AWJM process, the value of the “kerf” and “Ra” are decreased from 0.858 mm to 0.3704 mm and 5.41 mm to 4.443 mm respectively. In both the processes, the obtained results show a significant improvement in the responses.

  15. Arterial cannula shape optimization by means of the rotational firefly algorithm

    Science.gov (United States)

    Tesch, K.; Kaczorowska, K.

    2016-03-01

    This article presents global optimization results of arterial cannula shapes by means of the newly modified firefly algorithm. The search for the optimal arterial cannula shape is necessary in order to minimize losses and prepare the flow that leaves the circulatory support system of a ventricle (i.e. blood pump) before it reaches the heart. A modification of the standard firefly algorithm, the so-called rotational firefly algorithm, is introduced. It is shown that the rotational firefly algorithm allows for better exploration of search spaces which results in faster convergence and better solutions in comparison with its standard version. This is particularly pronounced for smaller population sizes. Furthermore, it maintains greater diversity of populations for a longer time. A small population size and a low number of iterations are necessary to keep to a minimum the computational cost of the objective function of the problem, which comes from numerical solution of the nonlinear partial differential equations. Moreover, both versions of the firefly algorithm are compared to the state of the art, namely the differential evolution and covariance matrix adaptation evolution strategies.

  16. Firefly courtship as the basis of the synchronization-response principle

    Science.gov (United States)

    Ramírez Ávila, G. M.; Deneubourg, J.-L.; Guisset, J.-L.; Wessel, N.; Kurths, J.

    2011-06-01

    Response to synchronization seems to be a widespread phenomenon specially in biological systems. We highlight this phenomenon studying the courtship of flashing fireflies in which a typical collective rhythm occurring only among the males arises and it is followed by a response of the females. Based on a model issued from electronic fireflies, we explain the synchronization of the males and the active responses of the females in the courtship of mingled (both sexes) populations of fireflies. The model also explains the courtship behavior of other species whose interactions follow the same logic even if their physical features are different. Moreover, the model can make predictions on the behavior of mingled and mixed (natural and artificial) groups of such animals. This finding could be considered as the basis of a new principle, namely the synchronization-response.

  17. Firefly Clock Synchronization in an 802.15.4 Wireless Network

    Directory of Open Access Journals (Sweden)

    Elmenreich Wilfried

    2009-01-01

    Full Text Available This paper describes the design and implementation of a distributed self-stabilizing clock synchronization algorithm based on the biological example of Asian Fireflies. Huge swarms of these fireflies use the principle of pulse coupled oscillators in order to synchronously emit light flashes to attract mating partners. When applying this algorithm to real sensor networks, typically, nodes cannot receive messages while transmitting, which prevents the networked nodes from reaching synchronization. In order to counteract this deafness problem, we adopt a variant of the Reachback Firefly Algorithm to distribute the timing of light flashes in a given time window without affecting the quality of the synchronization. A case study implemented on 802.15.4 Zigbee nodes presents the application of this approach for a time-triggered communication scheduling and coordinated duty cycling in order to enhance the battery lifetime of the nodes.

  18. In vivo bioluminescence emissions of the firefly Luciola praeusta at low temperatures.

    Science.gov (United States)

    Sharma, Upamanyu; Goswami, Angana; Rabha, Mana Mohan; Barua, Anurup Gohain

    2016-08-01

    Dependences of light emission from fireflies on external factors like temperature and magnetic field have been studied in recent times. Interesting conclusions have been drawn and hypotheses put forward in those studies. Here we report steady-state and time-resolved emissions of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera: Lampyridae: Luciolinae) at temperatures below 20°C. Intensity profiles of emission spectra remain the same as those recorded at normal or high temperatures. Two-flash combinations are frequently formed, giving the appearance of the resolution of a simple flash into two. Simple flashes also become abnormally broad with no uniformity in the increase of their durations. The flashes obtained from fireflies at low temperatures are compared and contrasted with the ones under a strong static magnetic field.

  19. FireFly: reconfigurable optical wireless networking data centers

    Science.gov (United States)

    Kavehrad, Mohsen; Deng, Peng; Gupta, H.; Longtin, J.; Das, S. R.; Sekar, V.

    2017-01-01

    We explore a novel, free-space optics based approach for building data center interconnects. Data centers (DCs) are a critical piece of today's networked applications in both private and public sectors. The key factors that have driven this trend are economies of scale, reduced management costs, better utilization of hardware via statistical multiplexing, and the ability to elastically scale applications in response to changing workload patterns. A robust DC network fabric is fundamental to the success of DCs and to ensure that the network does not become a bottleneck for high-performance applications. In this context, DC network design must satisfy several goals: high performance (e.g., high throughput and low latency), low equipment and management cost, robustness to dynamic traffic patterns, incremental expandability to add new servers or racks, and other practical concerns such as cabling complexity, and power and cooling costs. Current DC network architectures do not seem to provide a satisfactory solution, with respect to the above requirements. In particular, traditional static (wired) networks are either overprovisioned or oversubscribed. Recent works have tried to overcome the above limitations by augmenting a static (wired) "core" with some flexible links (RF-wireless or optical). These augmented architectures show promise, but offer only incremental improvement in performance. Specifically, RFwireless based augmented solutions also offer only limited performance improvement, due to inherent interference and range constraints of RF links. This paper explores an alternative design point—a fully flexible and all-wireless DC interrack network based on free-space optical (FSO) links. We call this FireFly as in; Free-space optical Inter-Rack nEtwork with high FLexibilitY. We will present our designs and tests using various configurations that can help the performance and reliability of the FSO links.

  20. Bioluminescence emissions of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae)

    Indian Academy of Sciences (India)

    A Gohain Barua; S Hazarika; N M Saikia; G D Baruah

    2009-06-01

    We recorded the in vivo emission and time-resolved spectra of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae). The emission spectrum shows that the full width at half maximum (FWHM) value for this particular species is 55 nm, which is significantly narrower than the in vivo half-widths reported till now. The time-resolved spectrum reveals that a flash of about 100 ms duration is, in fact, composed of a number of microsecond pulses. This suggests that the speed of the enzyme-catalysed chemiluminescence reaction in the firefly for the emission of light is much faster than was previously believed.

  1. Bioluminescence emissions of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae)

    Indian Academy of Sciences (India)

    A Gohain Barua; S Hazarika; N M Saikia; G D Baruah

    2009-09-01

    We recorded the in vivo emission and time-resolved spectra of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae). The emission spectrum shows that the full width at half maximum (FWHM) value for this particular species is 55 nm, which is significantly narrower than the in vivo half-widths reported till now. The time-resolved spectrum reveals that a flash of about 100 ms duration is, in fact, composed of a number of microsecond pulses. This suggests that the speed of the enzyme-catalysed chemiluminescence reaction in the firefly for the emission of light is much faster than was previously believed.

  2. Three-Dimensional Path Planning Method for Autonomous Underwater Vehicle Based on Modified Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Chang Liu

    2015-01-01

    Full Text Available Path planning is a classic optimization problem which can be solved by many optimization algorithms. The complexity of three-dimensional (3D path planning for autonomous underwater vehicles (AUVs requires the optimization algorithm to have a quick convergence speed. This work provides a new 3D path planning method for AUV using a modified firefly algorithm. In order to solve the problem of slow convergence of the basic firefly algorithm, an improved method was proposed. In the modified firefly algorithm, the parameters of the algorithm and the random movement steps can be adjusted according to the operating process. At the same time, an autonomous flight strategy is introduced to avoid instances of invalid flight. An excluding operator was used to improve the effect of obstacle avoidance, and a contracting operator was used to enhance the convergence speed and the smoothness of the path. The performance of the modified firefly algorithm and the effectiveness of the 3D path planning method were proved through a varied set of experiments.

  3. Testing a Firefly-Inspired Synchronization Algorithm in a Complex Wireless Sensor Network

    Science.gov (United States)

    Hao, Chuangbo; Song, Ping; Yang, Cheng; Liu, Xiongjun

    2017-01-01

    Data acquisition is the foundation of soft sensor and data fusion. Distributed data acquisition and its synchronization are the important technologies to ensure the accuracy of soft sensors. As a research topic in bionic science, the firefly-inspired algorithm has attracted widespread attention as a new synchronization method. Aiming at reducing the design difficulty of firefly-inspired synchronization algorithms for Wireless Sensor Networks (WSNs) with complex topologies, this paper presents a firefly-inspired synchronization algorithm based on a multiscale discrete phase model that can optimize the performance tradeoff between the network scalability and synchronization capability in a complex wireless sensor network. The synchronization process can be regarded as a Markov state transition, which ensures the stability of this algorithm. Compared with the Miroll and Steven model and Reachback Firefly Algorithm, the proposed algorithm obtains better stability and performance. Finally, its practicality has been experimentally confirmed using 30 nodes in a real multi-hop topology with low quality links. PMID:28282899

  4. A new approach to optic disc detection in human retinal images using the firefly algorithm.

    Science.gov (United States)

    Rahebi, Javad; Hardalaç, Fırat

    2016-03-01

    There are various methods and algorithms to detect the optic discs in retinal images. In recent years, much attention has been given to the utilization of the intelligent algorithms. In this paper, we present a new automated method of optic disc detection in human retinal images using the firefly algorithm. The firefly intelligent algorithm is an emerging intelligent algorithm that was inspired by the social behavior of fireflies. The population in this algorithm includes the fireflies, each of which has a specific rate of lighting or fitness. In this method, the insects are compared two by two, and the less attractive insects can be observed to move toward the more attractive insects. Finally, one of the insects is selected as the most attractive, and this insect presents the optimum response to the problem in question. Here, we used the light intensity of the pixels of the retinal image pixels instead of firefly lightings. The movement of these insects due to local fluctuations produces different light intensity values in the images. Because the optic disc is the brightest area in the retinal images, all of the insects move toward brightest area and thus specify the location of the optic disc in the image. The results of implementation show that proposed algorithm could acquire an accuracy rate of 100 % in DRIVE dataset, 95 % in STARE dataset, and 94.38 % in DiaRetDB1 dataset. The results of implementation reveal high capability and accuracy of proposed algorithm in the detection of the optic disc from retinal images. Also, recorded required time for the detection of the optic disc in these images is 2.13 s for DRIVE dataset, 2.81 s for STARE dataset, and 3.52 s for DiaRetDB1 dataset accordingly. These time values are average value.

  5. A clustering method of Chinese medicine prescriptions based on modified firefly algorithm.

    Science.gov (United States)

    Yuan, Feng; Liu, Hong; Chen, Shou-Qiang; Xu, Liang

    2016-12-01

    This paper is aimed to study the clustering method for Chinese medicine (CM) medical cases. The traditional K-means clustering algorithm had shortcomings such as dependence of results on the selection of initial value, trapping in local optimum when processing prescriptions form CM medical cases. Therefore, a new clustering method based on the collaboration of firefly algorithm and simulated annealing algorithm was proposed. This algorithm dynamically determined the iteration of firefly algorithm and simulates sampling of annealing algorithm by fitness changes, and increased the diversity of swarm through expansion of the scope of the sudden jump, thereby effectively avoiding premature problem. The results from confirmatory experiments for CM medical cases suggested that, comparing with traditional K-means clustering algorithms, this method was greatly improved in the individual diversity and the obtained clustering results, the computing results from this method had a certain reference value for cluster analysis on CM prescriptions.

  6. Firefly: A HOT camera core for thermal imagers with enhanced functionality

    Science.gov (United States)

    Pillans, Luke; Harmer, Jack; Edwards, Tim

    2015-06-01

    Raising the operating temperature of mercury cadmium telluride infrared detectors from 80K to above 160K creates new applications for high performance infrared imagers by vastly reducing the size, weight and power consumption of the integrated cryogenic cooler. Realizing the benefits of Higher Operating Temperature (HOT) requires a new kind of infrared camera core with the flexibility to address emerging applications in handheld, weapon mounted and UAV markets. This paper discusses the Firefly core developed to address these needs by Selex ES in Southampton UK. Firefly represents a fundamental redesign of the infrared signal chain reducing power consumption and providing compatibility with low cost, low power Commercial Off-The-Shelf (COTS) computing technology. This paper describes key innovations in this signal chain: a ROIC purpose built to minimize power consumption in the proximity electronics, GPU based image processing of infrared video, and a software customisable infrared core which can communicate wirelessly with other Battlespace systems.

  7. Bioheterojunction Effect on Fluorescence Origin and Efficiency Improvement of Firefly Chromophores

    CERN Document Server

    Cai, Duanjun; Milne, Bruce F; Nogueira, Fernando; 10.1021/jz1009532

    2010-01-01

    We propose the heterojunction effect in the analysis of the fluorescence mechanism of the firefly chromophore. Following this analysis, and with respect to the HOMO-LUMO gap alignment between the chromophore's functional fragments, three main heterojunction types (I, II, and I*) are identified. Time-dependent density-functional theory optical absorption calculations for the firefly chromophore show that the strongest excitation appears in the deprotonated anion state of the keto form. This can be explained by its high HOMO-LUMO overlap due to strong bio-heterojunction confinement. It is also found that the nitrogen atom in the thiazolyl rings, due to its larger electronegativity, plays a key role in the emission process, its importance growing when HOMO and LUMO overlap at its location. This principle is applied to enhance the chromophore's fluorescence efficiency and to guide the functionalization of molecular optoelectronic devices.

  8. Bioinspired Molecular Lantern: Tuning the Firefly Oxyluciferin Emission with Host-Guest Chemistry.

    Science.gov (United States)

    Saleh, Na'il; Suwaid, Abdul Rahman Ba; Alhalabi, Ahmad; Abuibaid, Ahmed Z A; Maltsev, Oleg V; Hintermann, Lukas; Naumov, Panče

    2016-08-11

    Fireflies generate flashes of visible light via luciferase-catalyzed chemiexcitation of the substrate (luciferin) to the first excited state of the emitter (oxyluciferin). Microenvironment effects are often invoked to explain the effects of the luciferase active pocket on the emission; however, the exceedingly complex spectrochemistry and synthetic burdens have precluded elucidation of the nature of these interactions. To decipher the effects of microenvironment on the light emission, here the hydrophobic interior of cucurbit[7]uril (CB7) is used to mimic the nonpolar active pocket of luciferase. The hydrophobic interior of CB7 induces shifts of the ground-state pKas by 1.9-2.5 units to higher values. Upon sequestration, the emission maxima of neutral firefly oxyluciferin and its conjugate monodeprotonated base are blue-shifted by 40 and 39 nm, respectively, resulting in visual color changes of the emitted light.

  9. Quantitative analysis of protein-protein interactions by split firefly luciferase complementation in plant protoplasts.

    Science.gov (United States)

    Li, Jian-Feng; Zhang, Dandan

    2014-07-01

    This unit describes the split firefly luciferase complementation (SFLC) assay, a high-throughput quantitative method that can be used to investigate protein-protein interactions (PPIs) in plant mesophyll protoplasts. In SFLC, the two proteins to be tested for interaction are expressed as chimeric proteins, each fused to a different half of firefly luciferase. If the proteins interact, a functional luciferase can be transitorily reconstituted, and is detected using the cell-permeable substrate D-luciferin. An advantage of the SFLC assay is that dynamic changes in PPIs in a cell can be detected in a near real-time manner. Another advantage is the unusually high DNA co-transfection and protein expression efficiencies that can be achieved in plant protoplasts, thereby enhancing the throughput of the method.

  10. Ab initio investigation on the structures and spectra of the firefly luciferin

    Institute of Scientific and Technical Information of China (English)

    LIU; YaJun; FANG; WeiHai

    2007-01-01

    The ground state (S0) geometry of the firefly luciferin (LH2) was optimized by both DFT B3LYP and CASSCF methods. The vertical excitation energies (Tv) of three low-lying states (S1, S2, and S3) were calculated by TD-DFT B3LYP//CASSCF method. The S1 geometry was optimized by CASSCF method. Its Tv and the transition energy (Te) were calculated by MS-CASPT2//CASSCF method. Both the TD-DFT and MS-CASPT2 calculated S1 state Tv values agree with the experimental one. The IPEA shift greatly affects the MS-CASPT2 calculated Tv values. Some important excited states of LH2 and oxyluciferin (oxyLH2) are charge-transfer states and have more than one dominant configuration, so for deeply researching the firefly bioluminescence, the multireference calculations are desired.

  11. Extension of the firefly algorithm and preference rules for solving MINLP problems

    Science.gov (United States)

    Costa, M. Fernanda P.; Francisco, Rogério B.; Rocha, Ana Maria A. C.; Fernandes, Edite M. G. P.

    2017-07-01

    An extension of the firefly algorithm (FA) for solving mixed-integer nonlinear programming (MINLP) problems is presented. Although penalty functions are nowadays frequently used to handle integrality conditions and inequality and equality constraints, this paper proposes the implementation within the FA of a simple rounded-based heuristic and four preference rules to find and converge to MINLP feasible solutions. Preliminary numerical experiments are carried out to validate the proposed methodology.

  12. Quantum Yield Determination Based on Photon Number Measurement, Protocols for Firefly Bioluminescence Reactions.

    Science.gov (United States)

    Niwa, Kazuki

    2016-01-01

    Quantum yield (QY), which is defined as the probability of photon production by a single bio/chemiluminescence reaction, is an important factor to characterize luminescence light intensity emitted diffusively from the reaction solution mixture. Here, methods to measure number of photons to determine QY according to the techniques of national radiometry standards are described. As an example, experiments using firefly bioluminescence reactions are introduced.

  13. Molecular Origin of Color Variation in Firefly (Beetle) Bioluminescence: A Chemical Basis for Biological Imaging.

    Science.gov (United States)

    Hirano, Takashi

    2016-01-01

    Firefly shows bioluminescence by "luciferin-luciferase" (L-L) reaction using luciferin, luciferase, ATP and O2. The chemical photon generation by an enzymatic reaction is widely utilized for analytical methods including biological imaging in the life science fields. To expand photondetecting analyses with firefly bioluminescence, it is important for users to understand the chemical basis of the L-L reaction. In particular, the emission color variation of the L-L reaction is one of the distinguishing characteristics for multicolor luciferase assay and in vivo imaging. From the viewpoint of fundamental chemistry, this review explains the recent progress in the studies on the molecular mechanism of emission color variation after showing the outline of the reaction mechanism of the whole L-L reaction. On the basis of the mechanism, the progresses in organic synthesis of luciferin analogs modulating their emission colors are also presented to support further developments of red/near infrared in vivo biological imaging utility of firefly bioluminescence.

  14. Firefly Algorithm for Cardinality Constrained Mean-Variance Portfolio Optimization Problem with Entropy Diversity Constraint

    Science.gov (United States)

    2014-01-01

    Portfolio optimization (selection) problem is an important and hard optimization problem that, with the addition of necessary realistic constraints, becomes computationally intractable. Nature-inspired metaheuristics are appropriate for solving such problems; however, literature review shows that there are very few applications of nature-inspired metaheuristics to portfolio optimization problem. This is especially true for swarm intelligence algorithms which represent the newer branch of nature-inspired algorithms. No application of any swarm intelligence metaheuristics to cardinality constrained mean-variance (CCMV) portfolio problem with entropy constraint was found in the literature. This paper introduces modified firefly algorithm (FA) for the CCMV portfolio model with entropy constraint. Firefly algorithm is one of the latest, very successful swarm intelligence algorithm; however, it exhibits some deficiencies when applied to constrained problems. To overcome lack of exploration power during early iterations, we modified the algorithm and tested it on standard portfolio benchmark data sets used in the literature. Our proposed modified firefly algorithm proved to be better than other state-of-the-art algorithms, while introduction of entropy diversity constraint further improved results. PMID:24991645

  15. Total evidence phylogeny and the evolution of adult bioluminescence in fireflies (Coleoptera: Lampyridae).

    Science.gov (United States)

    Martin, Gavin J; Branham, Marc A; Whiting, Michael F; Bybee, Seth M

    2017-02-01

    Fireflies are some of the most captivating organisms on the planet. They have a rich history as subjects of scientific study, especially in relation to their bioluminescent behavior. Yet, the phylogenetic relationships of fireflies are still poorly understood. Here, we present the first total evidence approach to reconstruct lampyrid phylogeny using both a molecular matrix from six loci and an extensive morphological matrix. Using this phylogeny we test the hypothesis that adult bioluminescence evolved after the origin of the firefly clade. The ancestral state of adult bioluminescence is recovered as non-bioluminescent with one to six gains and five to ten subsequent losses. The monophyly of the family, as well as the subfamilies is also tested. Ototretinae, Cyphonocerinae, Luciolinae (incl. Pristolycus), Amydetinae, "cheguevarinae" sensu Jeng 2008, and Photurinae are highly supported as monophyletic. With the exception of four taxa, Lampyrinae is also recovered as monophyletic with high support. Based on phylogenetic and morphological data Lamprohiza, Phausis, and Lamprigera are transferred to Lampyridae incertae sedis.

  16. Comparative Study of Krill Herd, Firefly and Cuckoo Search Algorithms for Unimodal and Multimodal Optimization

    Directory of Open Access Journals (Sweden)

    Gobind Preet Singh

    2014-02-01

    Full Text Available Today, in computer science, a computational challenge exists in finding a globally optimized solution from an enormously large search space. Various meta-heuristic methods can be used for finding the solution in a large search space. These methods can be explained as iterative search processes that efficiently perform the exploration and exploitation in the solution space. In this context, three such nature inspired meta-heuristic algorithms namely Krill Herd Algorithm (KH, Firefly Algorithm (FA and Cuckoo search Algorithm (CS can be used to find optimal solutions of various mathematical optimization problems. In this paper, the proposed algorithms were used to find the optimal solution of fifteen unimodal and multimodal benchmark test functions commonly used in the field of optimization and then compare their performances on the basis of efficiency, convergence, time and conclude that for both unimodal and multimodal optimization Cuckoo Search Algorithm via Lévy flight has outperformed others and for multimodal optimization Krill Herd algorithm is superior than Firefly algorithm but for unimodal optimization Firefly is superior than Krill Herd algorithm.

  17. A Comparative Study of Genetic and Firefly Algorithms for Sensor Placement in Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Guang-Dong Zhou

    2015-01-01

    Full Text Available Optimal sensor placement (OSP is an important task during the implementation of sophisticated structural health monitoring (SHM systems for large-scale structures. In this paper, a comparative study between the genetic algorithm (GA and the firefly algorithm (FA in solving the OSP problem is conducted. To overcome the drawback related to the inapplicability of the FA in optimization problems with discrete variables, some improvements are proposed, including the one-dimensional binary coding system, the Hamming distance between any two fireflies, and the semioriented movement scheme; also, a simple discrete firefly algorithm (SDFA is developed. The capabilities of the SDFA and the GA in finding the optimal sensor locations are evaluated using two disparate objective functions in a numerical example with a long-span benchmark cable-stayed bridge. The results show that the developed SDFA can find the optimal sensor configuration with high reliability. The comparative study indicates that the SDFA outperforms the GA in terms of algorithm complexity, computational efficiency, and result quality. The optimization mechanism of the FA has the potential to be extended to a wide range of optimization problems.

  18. Firefly: an optical lithographic system for the fabrication of holographic security labels

    Science.gov (United States)

    Calderón, Jorge; Rincón, Oscar; Amézquita, Ricardo; Pulido, Iván.; Amézquita, Sebastián.; Bernal, Andrés.; Romero, Luis; Agudelo, Viviana

    2016-03-01

    This paper introduces Firefly, an optical lithography origination system that has been developed to produce holographic masters of high quality. This mask-less lithography system has a resolution of 418 nm half-pitch, and generates holographic masters with the optical characteristics required for security applications of level 1 (visual verification), level 2 (pocket reader verification) and level 3 (forensic verification). The holographic master constitutes the main core of the manufacturing process of security holographic labels used for the authentication of products and documents worldwide. Additionally, the Firefly is equipped with a software tool that allows for the hologram design from graphic formats stored in bitmaps. The software is capable of generating and configuring basic optical effects such as animation and color, as well as effects of high complexity such as Fresnel lenses, engraves and encrypted images, among others. The Firefly technology gathers together optical lithography, digital image processing and the most advanced control systems, making possible a competitive equipment that challenges the best technologies in the industry of holographic generation around the world. In this paper, a general description of the origination system is provided as well as some examples of its capabilities.

  19. Uptake kinetics and biodistribution of C-14-D-luciferin-a radiolabeled substrate for the firefly luciferase catalyzed bioluminescence reaction : impact on bioluminescence based reporter gene imaging

    NARCIS (Netherlands)

    Berger, Frank; Paulmurugan, Ramasamy; Bhaumik, Srabani; Gambhir, Sanjiv Sam

    2008-01-01

    Purpose Firefly luciferase catalyzes the oxidative decarboxylation of D-luciferin to oxyluciferin in the presence of cofactors, producing bioluminescence. This reaction is used in optical bioluminescence-based molecular imaging approaches to detect the expression of the firefly luciferase reporter g

  20. A Firefly Learning Module for Environmental Sustainable Development in Samutsongkhram Province, THAILAND

    Directory of Open Access Journals (Sweden)

    Jongdee To-im

    2012-01-01

    Full Text Available A firefly learning module for the sustainable development was developed for Thai secondary school students in the study province. A deeper connection between environment, social and economic dimensions, which lies at the core of sustainability, became the key issue for this learning module. Also an important dimension of the module was the empowerment of the students themselves. Through brainstorming and ensuring activities, students were expected to act at the local level and to develop a deeper sense of responsibility. This study aimed at to develop learning module based on both the principle of inquiry approaches and the collaboration of a community of learners. Mixed methods paradigm was employed for data collection and analysis. Four data collection techniques: classroom observations, interviews, written documents, and questionnaire were employed. The Statistical Package for the Social Sciences was applied for quantitative data analysis. The qualitative data were analyzed using open and axial coding techniques. The analyzed data were categorized to describe context of developed learning module, the students’ conceptual understanding, and awareness toward ecosystems and firefly conservation. The study involved one-9th grade class of twenty students from one school in Samutsongkhram Province, Thailand. The results indicated that the developed learning module improved students’ conceptual understanding, perceptions, and self-reported behavior toward ecosystems and firefly conservation. The results of the effectiveness of this learning module clearly showed that the students gained significantly higher score in conceptual understanding and perceptions after participating in this learning module. The results from interviews showed that the students changed from a poor to a very good level of understanding after involvement in this learning module. The results also indicated that none of the students remained at the poor level after

  1. A HYBRID FIREFLY ALGORITHM WITH FUZZY-C MEAN ALGORITHM FOR MRI BRAIN SEGMENTATION

    Directory of Open Access Journals (Sweden)

    Mutasem K. Alsmadi

    2014-01-01

    Full Text Available Image processing is one of the essential tasks to extract suspicious region and robust features from the Magnetic Resonance Imaging (MRI. A numbers of the segmentation algorithms were developed in order to satisfy and increasing the accuracy of brain tumor detection. In the medical image processing brain image segmentation is considered as a complex and challenging part. Fuzzy c-means is unsupervised method that has been implemented for clustering of the MRI and different purposes such as recognition of the pattern of interest and image segmentation. However; fuzzy c-means algorithm still suffers many drawbacks, such as low convergence rate, getting stuck in the local minima and vulnerable to initialization sensitivity. Firefly algorithm is a new population-based optimization method that has been used successfully for solving many complex problems. This paper proposed a new dynamic and intelligent clustering method for brain tumor segmentation using the hybridization of Firefly Algorithm (FA with Fuzzy C-Means algorithm (FCM. In order to automatically segment MRI brain images and improve the capability of the FCM to automatically elicit the proper number and location of cluster centres and the number of pixels in each cluster in the abnormal (multiple sclerosis lesions MRI images. The experimental results proved the effectiveness of the proposed FAFCM in enhancing the performance of the traditional FCM clustering. Moreover; the superiority of the FAFCM with other state-of-the-art segmentation methods is shown qualitatively and quantitatively. Conclusion: A novel efficient and reliable clustering algorithm presented in this work, which is called FAFCM based on the hybridization of the firefly algorithm with fuzzy c-mean clustering algorithm. Automatically; the hybridized algorithm has the capability to cluster and segment MRI brain images.

  2. A firefly algorithm for solving competitive location-design problem: a case study

    Science.gov (United States)

    Sadjadi, Seyed Jafar; Ashtiani, Milad Gorji; Ramezanian, Reza; Makui, Ahmad

    2016-07-01

    This paper aims at determining the optimal number of new facilities besides specifying both the optimal location and design level of them under the budget constraint in a competitive environment by a novel hybrid continuous and discrete firefly algorithm. A real-world application of locating new chain stores in the city of Tehran, Iran, is used and the results are analyzed. In addition, several examples have been solved to evaluate the efficiency of the proposed model and algorithm. The results demonstrate that the performed method provides good-quality results for the test problems.

  3. Quantum/molecular mechanics study of firefly bioluminescence on luciferase oxidative conformation

    Science.gov (United States)

    Pinto da Silva, Luís; Esteves da Silva, Joaquim C. G.

    2014-07-01

    This is the first report of a computational study of the color tuning mechanism of firefly bioluminescence, using the oxidative conformation of luciferase. The results of these calculations demonstrated that the electrostatic field generated by luciferase is fundamental both for the emission shift and efficiency. Further calculations indicated that a shift in emission is achieved by modulating the energy, at different degrees, of the emissive and ground states. These differences in energy modulation will then lead to changes in the energy gap between the states.

  4. Continuous Firefly Algorithm for Optimal Tuning of Pid Controller in Avr System

    Science.gov (United States)

    Bendjeghaba, Omar

    2014-01-01

    This paper presents a tuning approach based on Continuous firefly algorithm (CFA) to obtain the proportional-integral- derivative (PID) controller parameters in Automatic Voltage Regulator system (AVR). In the tuning processes the CFA is iterated to reach the optimal or the near optimal of PID controller parameters when the main goal is to improve the AVR step response characteristics. Conducted simulations show the effectiveness and the efficiency of the proposed approach. Furthermore the proposed approach can improve the dynamic of the AVR system. Compared with particle swarm optimization (PSO), the new CFA tuning method has better control system performance in terms of time domain specifications and set-point tracking.

  5. Virus-mediated expression of firefly luciferase in the parasitic protozoan Giardia lamblia.

    OpenAIRE

    1995-01-01

    Giardia lamblia, a prevalent human pathogen and one of the lineages that branched earliest from prokaryotes, can be infected with a double-stranded RNA virus, giardiavirus (GLV). The 6,277-bp viral genome has been previously cloned (A.L. Wang, H.-M. Yang, K.A. Shen, and C.C. Wang, Proc. Natl. Acad. Sci. USA 90:8595-8599, 1993; C.-H. Wu, C.C. Wang, H.M. Yang, and A.L. Wang, Gene, in press) and was converted to a transfection vector for G. lamblia in the present study. By flanking the firefly l...

  6. Gross anatomy of central nervous system in firefly, Pteroptyx tener (Coleoptera: Lampyridae)

    Science.gov (United States)

    Hudawiyah, Nur; Wahida, O. Nurul; Norela, S.

    2015-09-01

    This paper describes for the first time the organization and fine structure of the central nervous system (CNS) in the fireflies, Pteroptyx tener (Coleoptera: Lampyridae). The morphology of the CNS was examined by using Carl Zeiss AxioScope A1 photomicroscope with iSolution Lite software. Some specific structural features such as the localization of protocerebrum, deutocerebrum and tritocerebrum in the brain region were analyzed. Other than that, the nerve cord and its peripheral structure were also analyzed. This study suggests that, there is a very obvious difference between male and female central nervous system which illustrates that they may differ in function in controlling physiological and behavioral activities.

  7. Genome Size in North American Fireflies: Substantial Variation Likely Driven by Neutral Processes

    Science.gov (United States)

    Johnston, J. Spencer; Stanger-Hall, Kathrin F.; Hjelmen, Carl E.; Hanrahan, Shawn J.; Korunes, Katharine; Hall, David

    2017-01-01

    Abstract Eukaryotic genomes show tremendous size variation across taxa. Proximate explanations for genome size variation include differences in ploidy and amounts of noncoding DNA, especially repetitive DNA. Ultimate explanations include selection on physiological correlates of genome size such as cell size, which in turn influence body size, resulting in the often-observed correlation between body size and genome size. In this study, we examined body size and repetitive DNA elements in relationship to the evolution of genome size in North American representatives of a single beetle family, the Lampyridae (fireflies). The 23 species considered represent an excellent study system because of the greater than 5-fold range of genome sizes, documented here using flow cytometry, and the 3-fold range in body size, measured using pronotum width. We also identified common genomic repetitive elements using low-coverage sequencing. We found a positive relationship between genome size and repetitive DNA, particularly retrotransposons. Both genome size and these elements were evolving as expected given phylogenetic relatedness. We also tested whether genome size varied with body size and found no relationship. Together, our results suggest that genome size is evolving neutrally in fireflies. PMID:28541478

  8. The evolution of adult light emission color in North American fireflies.

    Science.gov (United States)

    Hall, David W; Sander, Sarah E; Pallansch, Jennifer C; Stanger-Hall, Kathrin F

    2016-09-01

    Firefly species (Lampyridae) vary in the color of their adult bioluminescence. It has been hypothesized that color is selected to enhance detection by conspecifics. One mechanism to improve visibility of the signal is to increase contrast against ambient light. High contrast implies that fireflies active early in the evening will emit yellower luminescence to contrast against ambient light reflected from green vegetation, especially in habitats with high vegetation cover. Another mechanism to improve visibility is to use reflection off the background to enhance the light signal. Reflectance predicts that sedentary females will produce greener light to maximize reflection off the green vegetation on which they signal. To test these predictions, we recorded over 7500 light emission spectra and determined peak emission wavelength for 675 males, representing 24 species, at 57 field sites across the Eastern United States. We found support for both hypotheses: males active early in more vegetated habitats produced yellower flashes in comparison to later-active males with greener flashes. Further, in two of the eight species with female data, female light emissions were significantly greener as compared to males.

  9. Scaling Laws in the Transient Dynamics of Firefly-like Oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Rubido, N; Cabeza, C; Marti, A [Igua 4225, Instituto de Fisica, Facultad de Ciencias, Montevideo (Uruguay); Ramirez Avila, G M, E-mail: nrubido@fisica.edu.uy [Institut fuer Physik, Humboldt Universitaet zu Berlin (Germany)

    2011-03-01

    Fireflies constitute a paradigm of pulse-coupled oscillators. In order to tackle the problems related to synchronisation transients of pulse-coupled oscillators, a Light-Controlled Oscillator (LCO) model is presented. A single LCO constitutes a one-dimensional relaxation oscillator described by two distinct time-scales meant to mimic fireflies in the sense that: it is capable of emitting light in a pulse-like fashion and detect the emitted by others in order to adjust its oscillation. We present dynamical results for two interacting LCOs in the torus for all possible coupling configurations. Transient times to the synchronous limit cycle are obtained experimentally and numerically as a function of initial conditions and coupling strengths. Scaling laws are found based on dimensional analysis and critical exponents calculated, thus, global dynamic is restricted. Furthermore, an analytical orthogonal transformation that allows to calculate Floquet multipliers directly from the time series is presented. As a consequence, local dynamics is also fully characterized. This transformation can be easily extended to a system with an arbitrary number of interacting LCOs.

  10. Compensation for longitudinal chromatic aberration in the eye of the firefly squid, Watasenia scintillans.

    Science.gov (United States)

    Kröger, Ronald H H; Gislén, Anna

    2004-01-01

    The camera eyes of fishes and cephalopods have come forth by convergent evolution. In a variety of vertebrates capable of color vision, longitudinal chromatic aberration (LCA) of the optical system is corrected for by the exactly tuned longitudinal spherical aberration (LSA) of the crystalline lens. The LSA leads to multiple focal lengths, such that several wavelengths can be focused on the retina. We investigated whether that is also the case in the firefly squid (Watasenia scintillans), a cephalopod species that is likely to have color vision. It was found that the lens of W. scintillans is virtually free of LSA and uncorrected for LCA. However, the eye does not suffer from LCA because of a banked retina. Photoreceptors sensitive to short and long wavelengths are located at appropriate distances from the lens, such that they receive well-focused images. Such a design is an excellent solution for the firefly squid because a large area of the retina is monochromatically organized and it allows for double use of the surface area in the dichromatically organized part of the retina. However, it is not a universal solution since compensation for LCA by a banked retina requires that eye size and/or spectral separation between photopigments is small.

  11. Optimizing real power loss and voltage stability limit of a large transmission network using firefly algorithm

    Directory of Open Access Journals (Sweden)

    P. Balachennaiah

    2016-06-01

    Full Text Available This paper proposes a Firefly algorithm based technique to optimize the control variables for simultaneous optimization of real power loss and voltage stability limit of the transmission system. Mathematically, this issue can be formulated as nonlinear equality and inequality constrained optimization problem with an objective function integrating both real power loss and voltage stability limit. Transformers taps, unified power flow controller and its parameters have been included as control variables in the problem formulation. The effectiveness of the proposed algorithm has been tested on New England 39-bus system. Simulation results obtained with the proposed algorithm are compared with the real coded genetic algorithm for single objective of real power loss minimization and multi-objective of real power loss minimization and voltage stability limit maximization. Also, a classical optimization method known as interior point successive linear programming technique is considered here to compare the results of firefly algorithm for single objective of real power loss minimization. Simulation results confirm the potentiality of the proposed algorithm in solving optimization problems.

  12. Multiuser Detection in MIMO-OFDM Wireless Communication System Using Hybrid Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    B. Sathish Kumar

    2014-05-01

    Full Text Available In recent years, future generation wireless communication technologies are most the prominent fields in which many innovative techniques are used for effective communication. Orthogonal frequency-division multiplexing is one of the important technologies used for communication in future generation technologies. Although it gives efficient results, it has some problems during the implementation in real-time. MIMO and OFDM are integrated to have both their benefits. But, noise and interference are the major issues in the MIMO OFDM systems. To overcome these issues multiuser detection method is used in MIMO OFDM. Several algorithms and mathematical formulations have been presented for solving multiuser detection problem in MIMO OFDM systems. The algorithms such as genetic simulated annealing algorithm, hybrid ant colony optimization algorithm are used for multiuser detection problem in previous studies. But, due to the limitations of those optimization algorithms, the results obtained are not significant. In this research, to overcome the noise and interference problems, hybrid firefly optimization algorithm based on the evolutionary algorithm is proposed. The proposed algorithm is compared with the existing multiuser detection algorithm such as particle swarm optimization, CEFM-GADA [complementary error function mutation (CEFM and a differential algorithm (DA genetic algorithm (GA] and Hybrid firefly optimization algorithm based on evolutionary algorithm. The simulation results shows that performance of the proposed algorithm is better than the existing algorithm and it provides a satisfactory trade-off between computational complexity and detection performance

  13. Endmember extraction from hyperspectral image based on discrete firefly algorithm (EE-DFA)

    Science.gov (United States)

    Zhang, Chengye; Qin, Qiming; Zhang, Tianyuan; Sun, Yuanheng; Chen, Chao

    2017-04-01

    This study proposed a novel method to extract endmembers from hyperspectral image based on discrete firefly algorithm (EE-DFA). Endmembers are the input of many spectral unmixing algorithms. Hence, in this paper, endmember extraction from hyperspectral image is regarded as a combinational optimization problem to get best spectral unmixing results, which can be solved by the discrete firefly algorithm. Two series of experiments were conducted on the synthetic hyperspectral datasets with different SNR and the AVIRIS Cuprite dataset, respectively. The experimental results were compared with the endmembers extracted by four popular methods: the sequential maximum angle convex cone (SMACC), N-FINDR, Vertex Component Analysis (VCA), and Minimum Volume Constrained Nonnegative Matrix Factorization (MVC-NMF). What's more, the effect of the parameters in the proposed method was tested on both synthetic hyperspectral datasets and AVIRIS Cuprite dataset, and the recommended parameters setting was proposed. The results in this study demonstrated that the proposed EE-DFA method showed better performance than the existing popular methods. Moreover, EE-DFA is robust under different SNR conditions.

  14. Firefly as a novel swarm intelligence variable selection method in spectroscopy.

    Science.gov (United States)

    Goodarzi, Mohammad; dos Santos Coelho, Leandro

    2014-12-10

    A critical step in multivariate calibration is wavelength selection, which is used to build models with better prediction performance when applied to spectral data. Up to now, many feature selection techniques have been developed. Among all different types of feature selection techniques, those based on swarm intelligence optimization methodologies are more interesting since they are usually simulated based on animal and insect life behavior to, e.g., find the shortest path between a food source and their nests. This decision is made by a crowd, leading to a more robust model with less falling in local minima during the optimization cycle. This paper represents a novel feature selection approach to the selection of spectroscopic data, leading to more robust calibration models. The performance of the firefly algorithm, a swarm intelligence paradigm, was evaluated and compared with genetic algorithm and particle swarm optimization. All three techniques were coupled with partial least squares (PLS) and applied to three spectroscopic data sets. They demonstrate improved prediction results in comparison to when only a PLS model was built using all wavelengths. Results show that firefly algorithm as a novel swarm paradigm leads to a lower number of selected wavelengths while the prediction performance of built PLS stays the same.

  15. Adaptive Firefly Optimization on Reducing High Dimensional Weighted Word Affinity Graph

    Directory of Open Access Journals (Sweden)

    Dr. Poonam Yadhav

    2014-12-01

    Full Text Available Document analysis and retrieval system can best define an efficient information retrieval system. Among various processing stages in a document analysis and retrieval system, feature descriptors at processing volume limit require more importance while developing the system. This is mainly because of the increase in probability of getting high dimensional semantic description. This increases the vitality of opting a robust dimensionality reduction method for our retrieval system. Principle Component Analysis (PCA, Independent Component Analysis (ICA, etc are the most popular dimensionality reduction methods. However, they are highly complex while handling nonlinear data with multiple characteristics. Optimization algorithms can be a good alternative for the traditional methods. In fact, classical optimization algorithms such as Genetic Algorithm (GA, Particle Swarm Optimization (PSO, etc have been widely applied. However, the data handling remains inefficient under current data exploding scenario. In our previous work, we have exploited Firefly Algorithm (FA to solve the optimization problem. Due to parameter selection dilemma in traditional FA, this paper concentrates on using Adaptive Firefly Algorithm (AFA. AFA adaptively varies step search of solutions and hence improves the convergence rate of the algorithm. As a result, near – optimal solution can be obtained qualitatively. We further recommend the dimensionality reduction method to handle weighted word affinity graph to improve the retrieval efficiency.

  16. Application of Firefly Algorithm for Parameter Estimation of Damped Compound Pendulum

    Directory of Open Access Journals (Sweden)

    Saad Mohd Sazli

    2016-01-01

    Full Text Available This paper presents an investigation into the parameter estimation of the damped compound pendulum using Firefly algorithm method. In estimating the damped compound pendulum, the system necessarily needs a good model. Therefore, the aim of the work described in this paper is to obtain a dynamic model of the damped compound pendulum. By considering a discrete time form for the system, an autoregressive with exogenous input (ARX model structures was selected. In order to collect input-output data from the experiment, the PRBS signal is used to be input signal to regulate the motor speed. Where, the output signal is taken from position sensor. Firefly algorithm (FA algorithm is used to estimate the model parameters based on model 2nd orders. The model validation was done by comparing the measured output against the predicted output in terms of the closeness of both outputs via mean square error (MSE value. The performance of FA is measured in terms of mean square error (MSE.

  17. Optimal battery sizing in photovoltaic based distributed generation using enhanced opposition-based firefly algorithm for voltage rise mitigation.

    Science.gov (United States)

    Wong, Ling Ai; Shareef, Hussain; Mohamed, Azah; Ibrahim, Ahmad Asrul

    2014-01-01

    This paper presents the application of enhanced opposition-based firefly algorithm in obtaining the optimal battery energy storage systems (BESS) sizing in photovoltaic generation integrated radial distribution network in order to mitigate the voltage rise problem. Initially, the performance of the original firefly algorithm is enhanced by utilizing the opposition-based learning and introducing inertia weight. After evaluating the performance of the enhanced opposition-based firefly algorithm (EOFA) with fifteen benchmark functions, it is then adopted to determine the optimal size for BESS. Two optimization processes are conducted where the first optimization aims to obtain the optimal battery output power on hourly basis and the second optimization aims to obtain the optimal BESS capacity by considering the state of charge constraint of BESS. The effectiveness of the proposed method is validated by applying the algorithm to the 69-bus distribution system and by comparing the performance of EOFA with conventional firefly algorithm and gravitational search algorithm. Results show that EOFA has the best performance comparatively in terms of mitigating the voltage rise problem.

  18. Optimal Battery Sizing in Photovoltaic Based Distributed Generation Using Enhanced Opposition-Based Firefly Algorithm for Voltage Rise Mitigation

    Directory of Open Access Journals (Sweden)

    Ling Ai Wong

    2014-01-01

    Full Text Available This paper presents the application of enhanced opposition-based firefly algorithm in obtaining the optimal battery energy storage systems (BESS sizing in photovoltaic generation integrated radial distribution network in order to mitigate the voltage rise problem. Initially, the performance of the original firefly algorithm is enhanced by utilizing the opposition-based learning and introducing inertia weight. After evaluating the performance of the enhanced opposition-based firefly algorithm (EOFA with fifteen benchmark functions, it is then adopted to determine the optimal size for BESS. Two optimization processes are conducted where the first optimization aims to obtain the optimal battery output power on hourly basis and the second optimization aims to obtain the optimal BESS capacity by considering the state of charge constraint of BESS. The effectiveness of the proposed method is validated by applying the algorithm to the 69-bus distribution system and by comparing the performance of EOFA with conventional firefly algorithm and gravitational search algorithm. Results show that EOFA has the best performance comparatively in terms of mitigating the voltage rise problem.

  19. Phylogeny of North American fireflies (Coleoptera: Lampyridae): implications for the evolution of light signals.

    Science.gov (United States)

    Stanger-Hall, Kathrin F; Lloyd, James E; Hillis, David M

    2007-10-01

    Representatives of the beetle family Lampyridae ("fireflies", "lightningbugs") are well known for their use of light signals for species recognition during mate search. However, not all species in this family use light for mate attraction, but use chemical signals instead. The lampyrids have a worldwide distribution with more than 2000 described species, but very little is known about their phylogenetic relationships. Within North America, some lampyrids use pheromones as the major mating signal whereas others use visual signals such as extended glows or short light flashes. Here, we use a phylogenetic approach to illuminate the relationships of North American lampyrids and the evolution of their mating signals. Specifically, to establish the first phylogeny of all North American lampyrid genera, we sequenced nuclear (18S) and mitochondrial (16S and COI) genes to investigate the phylogenetic relationships of 26 species from 16 North American (NA) genera and one species from the genus Pterotus that was removed recently from the Lampyridae. To test the monophyly of the NA firefly fauna we sequenced the same genes from three European lampyrids and three Asian lampyrids, and included all available Genbank data (27 additional Asian lampyrids and a former lampyrid from Asia, Rhagophthalmus). Our results show that the North American lampyrids are not monophyletic. Different subgroups are closely related to species from Europe, Asia and tropical America, respectively. The present classification of fireflies into subfamilies and tribes is not, for the most part, supported by our phylogenetic analysis. Two former lampyrid genera, Pterotus and Rhagophthalmus, which have recently been removed from this family, are in fact nested within the Lampyridae. Further, we found that the use of light as a sexual signal may have originated one or four times among lampyrids, followed by nine or four losses, respectively. Short flashes originated at least twice and possibly three times

  20. Improved light extraction in the bioluminescent lantern of a Photuris firefly (Lampyridae)

    CERN Document Server

    Bay, Annick; Suhonen, Heikki; Vigneron, Jean Pol

    2012-01-01

    A common problem of light sources emitting from an homogeneous high-refractive index medium into air is the loss of photons by total internal reflection. Bioluminescent organisms, as well as artificial devices, have to face this problem. It is expected that life, with its mechanisms for evolution, would have selected appropriate optical structures to get around this problem, at least partially. The morphology of the lantern of a specific firefly in the genus Photuris has been examined. The optical properties of the different parts of this lantern have been modelled, in order to determine their positive or adverse effect with regard to the global light extraction. We conclude that the most efficient pieces of the lantern structure are the misfit of the external scales (which produce abrupt roughness in air) and the lowering of the refractive index at the level of the cluster of photocytes, where the bioluminescent production takes place.

  1. Establishment of a transient transfection system and expression of firefly luciferase in Entamoeba invadens.

    Science.gov (United States)

    Singh, Nishant; Ojha, Sandeep; Bhattacharya, Alok; Bhattacharya, Sudha

    2012-05-01

    Entamoeba invadens is used as a model system to study trophozoite to cyst differentiation since Entamoeba histolytica, the causative agent of amoebiasis cannot encyst in culture. However, a system for introduction of cloned genes in E. invadens is not available. Here we report an electroporation-based method for transfection of E. invadens tophozoites and demonstrate the expression of firefly luciferase reporter gene driven from the E. invadens ribosomal protein L3 promoter. The efficiency of luciferase expression driven from the promoters of three different E. invadens genes (rpl3, rps10 and h2b) was tested and found to correlate with the in vivo expression levels of the respective gene. This system will permit the analysis of regulatory elements required for gene expression in E. invadens.

  2. Solving machine loading problem of flexible manufacturing systems using a modified discrete firefly algorithm

    Directory of Open Access Journals (Sweden)

    Eleonora Bottani

    2017-06-01

    Full Text Available This paper proposes a modified discrete firefly algorithm (DFA applied to the machine loading problem of the flexible manufacturing systems (FMSs starting from the mathematical formulation adopted by Swarnkar & Tiwari (2004. The aim of the problem is to identify the optimal jobs sequence that simultaneously maximizes the throughput and minimizes the system unbalance according to given technological constraints (e.g. available tool slots and machining time. The results of the algorithm proposed have been compared with the existing and most recent swarm-based approaches available in the open literature using as benchmark the set of ten problems proposed by Mukhopadhyay et al. (1992. The algorithm shows results that are comparable and sometimes even better than most of the other approaches considering both the quality of the results provided and the computational times obtained.

  3. Improved light extraction in the bioluminescent lantern of a Photuris firefly (Lampyridae)

    Science.gov (United States)

    Bay, Annick; Cloetens, Peter; Suhonen, Heikki; Vigneron, Jean Pol

    2013-01-01

    A common problem of light sources emitting from an homogeneous high-refractive index medium into air is the loss of photons by total internal reflection. Bioluminescent organisms, as well as artificial devices, have to face this problem. It is expected that life, with its mechanisms for evolution, would have selected appropriate optical structures to get around this problem, at least partially. The morphology of the lantern of a specific firefly in the genus Photuris has been examined. The optical properties of the different parts of this lantern have been modeled, in order to determine their positive or adverse effect with regard to the global light extraction. We conclude that the most efficient pieces of the lantern structure are the misfit of the external scales (which produce abrupt roughness in air) and the lowering of the refractive index at the level of the cluster of photocytes, where the bioluminescent production takes place.

  4. Point mutations in firefly luciferase C-domain demonstrate its significance in green color of bioluminescence.

    Science.gov (United States)

    Modestova, Yulia; Koksharov, Mikhail I; Ugarova, Natalia N

    2014-09-01

    Firefly luciferase is a two-domain enzyme that catalyzes the bioluminescent reaction of firefly luciferin oxidation. Color of the emitted light depends on the structure of the enzyme, yet the exact color-tuning mechanism remains unknown by now, and the role of the C-domain in it is rarely discussed, because a very few color-shifting mutations in the C-domain were described. Recently we reported a strong red-shifting mutation E457K in the C-domain; the bioluminescence spectra of this enzyme were independent of temperature or pH. In the present study we investigated the role of the residue E457 in the enzyme using the Luciola mingrelica luciferase with a thermostabilized N-domain as a parent enzyme for site-directed mutagenesis. We obtained a set of mutants and studied their catalytic properties, thermal stability and bioluminescence spectra. Experimental spectra were represented as a sum of two components (bioluminescence spectra of putative "red" and "green" emitters); λmax of these components were constant for all the mutants, but the ratio of these emitters was defined by temperature and mutations in the C-domain. We suggest that each emitter is stabilized by a specific conformation of the active site; thus, enzymes with two forms of the active site coexist in the reactive media. The rigid structure of the C-domain is crucial for maintaining the conformation corresponding to the "green" emitter. We presume that the emitters are the keto- and enol forms of oxyluciferin.

  5. Japanese Interest in “Hotaru” (Fireflies and “Kabuto-Mushi” (Japanese Rhinoceros Beetles Corresponds with Seasonality in Visible Abundance

    Directory of Open Access Journals (Sweden)

    Kenta Takada

    2012-04-01

    Full Text Available Seasonal changes in the popularity of fireflies [usually Genji-fireflies (Luciola cruciata Motschulsky in Japan] and Japanese rhinoceros beetles [Allomyrina dichotoma (Linne] were investigated to examine whether contemporary Japanese are interested in visible emergence of these insects as seasonal events. The popularity of fireflies and Japanese rhinoceros beetles was assessed by the Google search volume of their Japanese names, “Hotaru” and “Kabuto-mushi” in Japanese Katakana script using Google Trends. The search volume index for fireflies and Japanese rhinoceros beetles was distributed across seasons with a clear peak in only particular times of each year from 2004 to 2011. In addition, the seasonal peak of popularity for fireflies occurred at the beginning of June, whereas that for Japanese rhinoceros beetles occurred from the middle of July to the beginning of August. Thus seasonal peak of each species coincided with the peak period of the emergence of each adult stage. These findings indicated that the Japanese are interested in these insects primarily during the time when the two species are most visibly abundant. Although untested, this could suggest that fireflies and Japanese rhinoceros beetles are perceived by the general public as indicators or symbols of summer in Japan.

  6. Reliability-Based Design Optimization of Trusses with Linked-Discrete Design Variables using the Improved Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    N. M. Okasha

    2016-04-01

    Full Text Available In this paper, an approach for conducting a Reliability-Based Design Optimization (RBDO of truss structures with linked-discrete design variables is proposed. The sections of the truss members are selected from the AISC standard tables and thus the design variables that represent the properties of each section are linked. Latin hypercube sampling is used in the evaluation of the structural reliability. The improved firefly algorithm is used for the optimization solution process. It was found that in order to use the improved firefly algorithm for efficiently solving problems of reliability-based design optimization with linked-discrete design variables; it needs to be modified as proposed in this paper to accelerate its convergence.

  7. Identification of cis-acting signals in the giardiavirus (GLV) genome required for expression of firefly luciferase in Giardia lamblia.

    OpenAIRE

    1996-01-01

    Giardiavirus (GLV) is a 6,277-bp double-stranded RNA virus of Giardia lamblia, one of the earliest eukaryotic divergents from the prokaryotes. Our previous success in GLV-mediated transfection of G. lamblia has provided an effective way of monitoring the mechanisms underlining GLV gene replication and mRNA translation in this organism. Here we have investigated the cis-acting signals in the GLV genome that regulate replication, transcription, and translation of an inserted firefly luciferase ...

  8. A novel firefly luciferase biosensor enhances the detection of apoptosis induced by ESAT-6 family proteins of Mycobacterium tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Junwei; Zhang, Huan; Fang, Liurong; Xi, Yongqiang; Zhou, Yanrong; Luo, Rui; Wang, Dang, E-mail: wangdang511@126.com; Xiao, Shaobo; Chen, Huanchun

    2014-10-03

    Highlights: • We developed a novel firefly luciferase based biosensor to detect apoptosis. • The novel biosensor 233-DnaE-DEVDG was reliable, sensitive and convenient. • 233-DnaE-DEVDG faithfully indicated ESAT-6 family proteins of Mycobacterium tuberculosis induced apoptosis. • EsxA, esxT and esxL in ESAT-6 family proteins induced apoptosis. • Activation of nuclear factor-κB (NF-κB) participated in esxT-induced apoptosis. - Abstract: The activation of caspase-3 is a key surrogate marker for detecting apoptosis. To quantitate caspase-3 activity, we constructed a biosensor comprising a recombinant firefly luciferase containing a caspase-3 cleavage site. When apoptosis was induced, caspase-3 cleavage of the biosensor activated firefly luciferase by a factor greater than 25. The assay conveniently detected apoptosis in real time, indicating that it will facilitate drug discovery. We screened ESAT-6 family proteins of Mycobacterium tuberculosis and found that esxA, esxT and esxL induced apoptosis. Further, activation of nuclear factor-κB (NF-κB) and the NF-κB-regulated genes encoding tumor necrosis factor-α (TNF-α) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) participated in esxT-induced apoptosis. We conclude that this assay is useful for high-throughput screening to identify and characterize proteins and drugs that regulate apoptosis.

  9. An Optimal Energy Management System for Electric Vehicles using Firefly Optimization Algorithm based Dynamic EDF Scheduling

    Directory of Open Access Journals (Sweden)

    E.Kayalvizhi

    2015-08-01

    Full Text Available Mitigation of global warming gases from burning gasoline for transportation in vehicles is one of the biggest and most complex issues the world has ever faced. In an intention to eradicate the environmental crisis caused due to global warming, electric vehicles were been introduced that are powered by electric motor which works on the energy stored in a battery pack. Inspired by the research on power management in electric vehicles, this paper focuses on the development of an energy management system for electric vehicles (EMSEV to optimally balance the energy from battery pack. The proposed methodology uses firefly optimization algorithm to optimize the power consumption of the devices like electric motor, power steering, air conditioner, power window, automatic door locks, radio, speaker, horn, wiper, GPS, internal and external lights etc., from the battery in electric vehicles. Depending upon the distance to cover and the battery availability, the devices are made to switch down automatically through dynamic EDF scheduling. CAN protocol is used for effective communication between the devices and the controller. Simulation results are obtained using MATLAB.

  10. Weighing Efficiency-Robustness in Supply Chain Disruption by Multi-Objective Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Tong Shu

    2016-03-01

    Full Text Available This paper investigates various supply chain disruptions in terms of scenario planning, including node disruption and chain disruption; namely, disruptions in distribution centers and disruptions between manufacturing centers and distribution centers. Meanwhile, it also focuses on the simultaneous disruption on one node or a number of nodes, simultaneous disruption in one chain or a number of chains and the corresponding mathematical models and exemplification in relation to numerous manufacturing centers and diverse products. Robustness of the design of the supply chain network is examined by weighing efficiency against robustness during supply chain disruptions. Efficiency is represented by operating cost; robustness is indicated by the expected disruption cost and the weighing issue is calculated by the multi-objective firefly algorithm for consistency in the results. It has been shown that the total cost achieved by the optimal target function is lower than that at the most effective time of supply chains. In other words, the decrease of expected disruption cost by improving robustness in supply chains is greater than the increase of operating cost by reducing efficiency, thus leading to cost advantage. Consequently, by approximating the Pareto Front Chart of weighing between efficiency and robustness, enterprises can choose appropriate efficiency and robustness for their longer-term development.

  11. The reaction process of firefly bioluminescence triggered by photolysis of caged-ATP.

    Science.gov (United States)

    Kageyama, Takeshi; Tanaka, Masatoshi; Sekiya, Takao; Ohno, Shin-Ya; Wada, Naohisa

    2011-01-01

    The reaction process of firefly bioluminescence was studied by photolyzing caged-ATP to adenosine triphosphate (ATP) within 100 ms. The intensity of luminescence increases markedly to reach a maximum within 1 s, maintains almost the same intensity up to 5 s and then decays monotonically. The rise γ(1) and decay γ(2) rate constants were determined to be about 5 s(-1) and 1 × 10(-2) s(-1), respectively, so as to phenomenologically fit the time course. A second luminescence peak appears after around 350 s. The dependence of the rate constants on the concentrations of reactants and a viscous reagent revealed that two kinds of reaction contribute the observed time course: (1) an intrinsic reaction by ATP photolyzed from caged-ATP that is already trapped in luciferase; and (2) a diffusion-controlled reaction by free ATP in the buffer solution outside luciferase. Numerical analysis based on reaction kinetics related γ(1) and γ(2) to the rate constants of a three-step reaction model, and accurately described the effects of concentration of reactants and a viscous reagent on the time courses of bioluminescence. Thus, it has been clearly concluded that the binding mode of caged-ATP at the catalytic center of luciferase is very different from that of ATP.

  12. A Heuristic Approach for optimization of Non Linear process using Firefly Algorithm and Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    M. Kandasamy

    2014-12-01

    Full Text Available A comparison study of Firefly Algorithm (FA and Bacterial Foraging Algorithm (BFO optimization is carried out by applying them to a Non Linear pH neutralization process. In process control engineering, the Proportional, Derivative, Integral controller tuning parameters are deciding the performance of the controller to ensure the good performance of the plant. The FA and BFO algorithms are applied to obtain the optimum values of controller parameters. The performance indicators such as servo response and regulatory response tests are carried out to evaluate the efficiency of the heuristic algorithm based controllers. The error minimization criterion such as Integral Absolute Error (IAE, Integral Square Error (ISE, Integral Time Square Error (ITSE, Integral Time Absolute Error (ITAE and Time domain specifications – rise time, Peak Overshoot and settling time are considered for the study of the performance of the controllers. The study indicates that, FA tuned PID controller provides marginally better set point tracking, load disturbance rejection, time domain specifications and error minimization for the Non Linear pH neutralization process compared to BFO tuned PID controller.

  13. Firefly Luciferase Mutants Allow Substrate-Selective Bioluminescence Imaging in the Mouse Brain.

    Science.gov (United States)

    Adams, Spencer T; Mofford, David M; Reddy, G S Kiran Kumar; Miller, Stephen C

    2016-04-11

    Bioluminescence imaging is a powerful approach for visualizing specific events occurring inside live mice. Animals can be made to glow in response to the expression of a gene, the activity of an enzyme, or the growth of a tumor. But bioluminescence requires the interaction of a luciferase enzyme with a small-molecule luciferin, and its scope has been limited by the mere handful of natural combinations. Herein, we show that mutants of firefly luciferase can discriminate between natural and synthetic substrates in the brains of live mice. When using adeno-associated viral (AAV) vectors to express luciferases in the brain, we found that mutant luciferases that are inactive or weakly active with d-luciferin can light up brightly when treated with the aminoluciferins CycLuc1 and CycLuc2 or their respective FAAH-sensitive luciferin amides. Further development of selective luciferases promises to expand the power of bioluminescence and allow multiple events to be imaged in the same live animal.

  14. Gaussia Luciferase for Bioluminescence Tumor Monitoring in Comparison with Firefly Luciferase

    Directory of Open Access Journals (Sweden)

    Yusuke Inoue

    2011-09-01

    Full Text Available Gaussia luciferase (Gluc is a secreted reporter, and its expression in living animals can be assessed by in vivo bioluminescence imaging (BLI or blood assays. We characterized Gluc as an in vivo reporter in comparison with firefly luciferase (Fluc. Mice were inoculated subcutaneously with tumor cells expressing both Fluc and Gluc and underwent Flue BLI, Gluc BLI, blood assays of Glue activity, and caliper measurement. In Gluc BLI, the signal from the tumor peaked immediately and then decreased rapidly. In the longitudinal monitoring, all measures indicated an increase in tumor burden early after cell inoculation. However, the increase reached plateaus in Gluc BLI and Fluc BLI despite a continuous increase in the caliper measurement and Gluc blood assay. Significant correlations were found between the measures, and the correlation between the blood signal and caliper volume was especially high. Gluc allows tumor monitoring in mice and should be applicable to dual-reporter assessment in combination with Fluc. The Gluc blood assay appears to provide a reliable indicator of viable tumor burden, and the combination of a blood assay and in vivo BLI using Glue should be promising for quantifying and localizing the tumors.

  15. A novel nature inspired firefly algorithm with higher order neural network: Performance analysis

    Directory of Open Access Journals (Sweden)

    Janmenjoy Nayak

    2016-03-01

    Full Text Available The applications of both Feed Forward Neural network and Multilayer perceptron are very diverse and saturated. But the linear threshold unit of feed forward networks causes fast learning with limited capabilities, while due to multilayering, the back propagation of errors exhibits slow training speed in MLP. So, a higher order network can be constructed by correlating between the input variables to perform nonlinear mapping using the single layer of input units for overcoming the above drawbacks. In this paper, a Firefly based higher order neural network has been proposed for data classification for maintaining fast learning and avoids the exponential increase of processing units. A vast literature survey has been conducted to review the state of the art of the previous developed models. The performance of the proposed method has been tested with various benchmark datasets from UCI machine learning repository and compared with the performance of other established models. Experimental results imply that the proposed method is fast, steady, reliable and provides better classification accuracy than others.

  16. Excited-state intermolecular proton transfer of firefly luciferin III. Proton transfer to a mild base.

    Science.gov (United States)

    Presiado, Itay; Erez, Yuval; Huppert, Dan

    2010-12-30

    Steady-state and time-resolved techniques were employed to study the excited-state proton transfer (ESPT) from d-luciferin, the natural substrate of the firefly luciferase, to the mild acetate base in aqueous solutions. We found that in 1 M aqueous solutions of acetate or higher, a proton transfer (PT) process to the acetate takes place within 30 ps in both H(2)O and D(2)O solutions. The time-resolved emission signal is composed of three components. We found that the short-time component decay time is 300 and 600 fs in H(2)O and D(2)O, respectively. This component is attributed either to a PT process via the shortest water bridged complex available, ROH··H(2)O··Ac(-), or to PT taking place within a contact ion pair. The second time component of 2000 and 3000 fs for H(2)O and D(2)O, respectively, is attributed to ROH* acetate complex, whose proton wire is longer by one water molecule. The decay rate of the third, long-time component is proportional to the acetate concentration. We attribute it to the diffusion-assisted reaction as well as to PT process to the solvent.

  17. Solution to automatic generation control problem using firefly algorithm optimized I(λ)D(µ) controller.

    Science.gov (United States)

    Debbarma, Sanjoy; Saikia, Lalit Chandra; Sinha, Nidul

    2014-03-01

    Present work focused on automatic generation control (AGC) of a three unequal area thermal systems considering reheat turbines and appropriate generation rate constraints (GRC). A fractional order (FO) controller named as I(λ)D(µ) controller based on crone approximation is proposed for the first time as an appropriate technique to solve the multi-area AGC problem in power systems. A recently developed metaheuristic algorithm known as firefly algorithm (FA) is used for the simultaneous optimization of the gains and other parameters such as order of integrator (λ) and differentiator (μ) of I(λ)D(µ) controller and governor speed regulation parameters (R). The dynamic responses corresponding to optimized I(λ)D(µ) controller gains, λ, μ, and R are compared with that of classical integer order (IO) controllers such as I, PI and PID controllers. Simulation results show that the proposed I(λ)D(µ) controller provides more improved dynamic responses and outperforms the IO based classical controllers. Further, sensitivity analysis confirms the robustness of the so optimized I(λ)D(µ) controller to wide changes in system loading conditions and size and position of SLP. Proposed controller is also found to have performed well as compared to IO based controllers when SLP takes place simultaneously in any two areas or all the areas. Robustness of the proposed I(λ)D(µ) controller is also tested against system parameter variations.

  18. Vibrational spectra of chemical and isotopic variants of oxyluciferin, the light emitter of firefly bioluminescence.

    Science.gov (United States)

    Maltsev, Oleg V; Yue, Ling; Rebarz, Mateusz; Hintermann, Lukas; Sliwa, Michel; Ruckebusch, Cyril; Pejov, Ljupčo; Liu, Ya-Jun; Naumov, Panče

    2014-08-18

    The chemical complexity of oxyluciferin (OxyLH2), the light-emitting molecule in the bioluminescence of fireflies, originates from the possibility of keto/enol tautomerism and single or double deprotonation. Herein, we present detailed infrared spectroscopic analysis of OxyLH2 and several of its chemical isomers and isotopomers. To facilitate the future characterization of its biogenic forms, we provide accurate assignments of the solid-state and solution FTIR spectra of OxyLH2 based on comparison to six isotopically labeled variants ([2-(13)C]-OxyLH2, [3-(15)N]-OxyLH2, [4-(13)C]-OxyLH2, [5-(13)C]-OxyLH2, [2'-(13)C]-OxyLH2, [3'-(15)N]-OxyLH2), five closely related structural analogues, and theoretically computed spectra. The computed DFT harmonic vibrational force fields (B3LYP and M06 functionals with basis sets of varying flexibility up to 6-311++G**) reproduce well the observed shifts in the IR spectra of both isotopically labeled and structurally related analogues.

  19. Receptors for /sup 3/H-octopamine in the adult firefly light organ

    Energy Technology Data Exchange (ETDEWEB)

    Hashemzadeh, H.; Hollingworth, R.M.; Voliva, A.

    1985-08-05

    /sup 3/H-Octopamine binds reversibly and with high affinity to sites on adult firefly light organ membranes. The binding is characterized by multiple affinities. Scatchard analysis supported a two site binding model with a tentative Kd value of about 1 nM for the high affinity component. The more abundant lower affinity site had a Kd value of about 60 nM. Guanyl nucleotides (Gpp(NH)p and GTP) greatly reduced the apparent number of octopamine binding sites. Competition studies with known octopaminergic agonists including the formamidine pesticides chlordimeform (CDM) and N-demethylchlordimeform (DCDM) showed the following rank order of potencies in displacing octopamine: DCDM > octopamine = synephrine > naphazoline > clonidine > CDM. It was also observed that phentolamine was much more active than propranolol in antagonizing OA-binding. These relative activities are similar to the abilities of the same compounds to alter adenylate cyclase activity in light organ homogenates. Together with the effect of GTP on binding, these results suggest that the binding sites are functional octopamine receptors of the light organ. 27 references, 3 figures, 1 table.

  20. Intraoperative localization of the parathyroid glands with indocyanine green and Firefly(R) technology during BABA robotic thyroidectomy.

    Science.gov (United States)

    Yu, Hyeong Won; Chung, Joon Woo; Yi, Jin Wook; Song, Ra-Yeong; Lee, Joon-Hyop; Kwon, Hyungju; Kim, Su-Jin; Chai, Young Jun; Choi, June Young; Lee, Kyu Eun

    2017-07-01

    It is unclear whether near-infrared (NIR) light-induced indocyanine green (ICG) fluorescence can effectively identify, and thus permit the preservation of, parathyroid glands in bilateral axillo-breast approach (BABA) robotic thyroidectomy. This case-control study with a prospectively recruited consecutive series and a retrospectively selected control group assessed the usefulness of ICG with Firefly(R) technology to identify the parathyroid glands intraoperatively during BABA robotic thyroidectomy. All consecutive patients (N = 22) who were scheduled to undergo BABA robotic thyroidectomy for papillary thyroid carcinoma in December 2013-August 2015 and met the study eligibility criteria were recruited prospectively. ICG fluorescence was used with the Firefly system (NIR illuminator: 805 nm; filter: 825 nm) integrated in the da Vinci Si robot system to identify the lower parathyroid glands. Parathyroid hormone levels were recorded on postoperative days 0, 1, 2, and 14. Propensity score matching was used to identify an age-, gender-, tumor size-, and operation type-matched group of control patients who underwent BABA robotic thyroidectomy without the Firefly system. The two groups were compared in terms of parathyroid-related outcomes. ICG fluorescence-mediated identification of the parathyroid and thyroid glands required on average (range) 203 ± 89 (125-331) and 207 ± 112 (130-356) s, respectively. The mean (range) fluorescence duration in these glands was 20.8 ± 6.0 (16.6-35.8) and 20.1 ± 7.3 (15.5-33.8) min, respectively. The ICG group had a significantly lower rate of incidental parathyroidectomy than the control group (0 vs. 15.9%, P = 0.048). ICG with NIR light may feasibly and safely identify the parathyroid glands in BABA robotic thyroidectomy.

  1. Optimasi Time Dial Setting (TDS Relay Arus Lebih Menggunakan Adaptive Modified Firefly Algorithm Pada Sistem Kelistrikan PT. Pupuk Kalimantan Timur

    Directory of Open Access Journals (Sweden)

    Vincentius Raki Mahindhara

    2017-01-01

    Full Text Available Penggunaan relay arus lebih (over current relay pada industri memerlukan pengaturan beberapa parameter seperti arus pickup (Ip, time dial setting (TDS, serta waktu operasi (top. Dalam standard acuan dicantumkan batasan-batasan dan formulasi dalam menentukan parameter tersebut. Salah satu permasalahan adalah penentuan TDS pada relay inverse (Kode ANSI 51. Umumnya penentuan nilai TDS dilakukan dengan metode trial and error, hal ini dirasa kurang efektif sehingga diusulkan suatu metode baru dalam menentukan TDS pada sistem kelistrikan eksisting PT. Pupuk Kalimantan Timur. Digunakan algoritma adaptive firefly yang dimodifikasi dalam menyelesaikan permasalahan dengan mempertimbangkan kurva starting motor dan perbedaan tipe kurva antar relay

  2. ECG based Atrial Fibrillation detection using Sequency Ordered Complex Hadamard Transform and Hybrid Firefly Algorithm

    Directory of Open Access Journals (Sweden)

    Padmavathi Kora

    2017-06-01

    Full Text Available Electrocardiogram (ECG, a non-invasive diagnostic technique, used for detecting cardiac arrhythmia. From last decade industry dealing with biomedical instrumentation and research, demanding an advancement in its ability to distinguish different cardiac arrhythmia. Atrial Fibrillation (AF is an irregular rhythm of the human heart. During AF, the atrial moments are quicker than the normal rate. As blood is not completely ejected out of atria, chances for the formation of blood clots in atrium. These abnormalities in the heart can be identified by the changes in the morphology of the ECG. The first step in the detection of AF is preprocessing of ECG, which removes noise using filters. Feature extraction is the next key process in this research. Recent feature extraction methods, such as Auto Regressive (AR modeling, Magnitude Squared Coherence (MSC and Wavelet Coherence (WTC using standard database (MIT-BIH, yielded a lot of features. Many of these features might be insignificant containing some redundant and non-discriminatory features that introduce computational burden and loss of performance. This paper presents fast Conjugate Symmetric Sequency Ordered Complex Hadamard Transform (CS-SCHT for extracting relevant features from the ECG signal. The sparse matrix factorization method is used for developing fast and efficient CS-SCHT algorithm and its computational performance is examined and compared to that of the HT and NCHT. The applications of the CS-SCHT in the ECG-based AF detection is also discussed. These fast CS-SCHT features are optimized using Hybrid Firefly and Particle Swarm Optimization (FFPSO to increase the performance of the classifier.

  3. Improving accuracy of intraoperative diagnosis of endometriosis: Role of firefly in minimal access robotic surgery

    Directory of Open Access Journals (Sweden)

    John R Lue

    2016-01-01

    Full Text Available Endometriosis continues to be a major primary gynecologic etiology of chronic pelvic pain. The symptom profile, which includes cyclic pelvic pain, dysmenorrhea, and dyspareunia or dyschezia, is nonspecific and does not correlate with the extent or severity of disease. Trans-vaginal or trans-rectal ultrasound, as well as magnetic resonance imaging, can help visualize endometriomas and deeply infiltrating endometriosis. Additionally, there have been no serum marker tests available so far. However, even intraoperatively, the diagnosis may be missed, leading to under diagnosis and delayed or noninitiation of treatment. There are thought to be three distinct endometriotic lesions of the pelvis that are seen laparoscopically. The first is that which is visible on the pelvic peritoneal surface or the surface of the ovary, which is commonly termed peritoneal endometriosis. Second, endometriotic lesions that occur within the ovary and form cysts that are often lined with endometrioid mucosa are termed endometriomas. Lastly, rectovaginal endometriomas are endometriotic lesions that contain a mixture of adipose and fibrous tissue located between the rectum and vagina. All of these lesions can be singular or multiple and the pelvis may contain one or all three types of lesions. The shared histologic feature with all three lesions is the presence of endometrial epithelial cells or endometrial stroma. During a diagnostic procedure, the da-Vinci robot and its firefly mode allow for three dimensional visualization and seven degrees of instrument articulation for meticulous dissection of fibrotic areas of peritoneum that may contain deep infiltrating lesions of endometriosis. This case report describes a relatively new and innovative technique for effectively diagnosing and successfully treating endometriosis when other less invasive methods have failed.

  4. Molecular basis for the high-affinity binding and stabilization of firefly luciferase by PTC124

    Energy Technology Data Exchange (ETDEWEB)

    Auld, Douglas S.; Lovell, Scott; Thorne, Natasha; Lea, Wendy A.; Maloney, David J.; Shen, Min; Rai, Ganesha; Battaile, Kevin P.; Thomas, Craig J.; Simeonov, Anton; Hanzlik, Robert P.; Inglese, James (NIH); (Kansas); (HWMRI)

    2010-04-07

    Firefly luciferase (FLuc), an ATP-dependent bioluminescent reporter enzyme, is broadly used in chemical biology and drug discovery assays. PTC124 Ataluren; (3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid) discovered in an FLuc-based assay targeting nonsense codon suppression, is an unusually potent FLuc-inhibitor. Paradoxically, PTC124 and related analogs increase cellular FLuc activity levels by posttranslational stabilization. In this study, we show that FLuc inhibition and stabilization is the result of an inhibitory product formed during the FLuc-catalyzed reaction between its natural substrate, ATP, and PTC124. A 2.0 {angstrom} cocrystal structure revealed the inhibitor to be the acyl-AMP mixed-anhydride adduct PTC124-AMP, which was subsequently synthesized and shown to be a high-affinity multisubstrate adduct inhibitor (MAI; KD = 120 pM) of FLuc. Biochemical assays, liquid chromatography/mass spectrometry, and near-attack conformer modeling demonstrate that formation of this novel MAI is absolutely dependent upon the precise positioning and reactivity of a key meta-carboxylate of PTC124 within the FLuc active site. We also demonstrate that the inhibitory activity of PTC124-AMP is relieved by free coenzyme A, a component present at high concentrations in luciferase detection reagents used for cell-based assays. This explains why PTC124 can appear to increase, instead of inhibit, FLuc activity in cell-based reporter gene assays. To our knowledge, this is an unusual example in which the 'off-target' effect of a small molecule is mediated by an MAI mechanism.

  5. A modified firefly algorithm applied to the nuclear reload problem of a pressurized water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Iona Maghali Santos de; Schirru, Roberto, E-mail: ioliveira@con.ufrj.b, E-mail: schirru@lmp.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

    2011-07-01

    The Nuclear Reactor Reload Problem (NRRP) is an issue of great importance and concern in nuclear engineering. It is the problem related with the periodic operation of replacing part of the fuel of a nuclear reactor. Traditionally, this procedure occurs after a period of operation called a cycle, or whenever the nuclear power plant is unable to continue operating at its nominal power. Studied for more than 40 years, the NRRP still remains a challenge for many optimization techniques due to its multiple objectives concerning economics, safety and reactor physics calculations. Characteristics such as non-linearity, multimodality and high dimensionality also make the NRRP a very complex optimization problem. In broad terms, it aims at getting the best arrangement of fuel in the nuclear reactor core that leads to a maximization of the operating time. The primary goal is to design fuel loading patterns (LPs) so that the core produces the required energy output in an economical way, without violating safety limits. Since multiple feasible solutions can be obtained to this problem, judicious optimization is required in order to identify the most economical among them. In this sense, this paper presents a new contribution in this area and introduces a modified firefly algorithm (FA) to perform LPs optimization for a pressurized water reactor. Based on the original FA introduced by Xin-She Yang in 2008, the proposed methodology seems to be very promising as an optimizer to the NRRP. The experiments performed and the comparisons with some well known best performing algorithms from the literature, confirm this statement. (author)

  6. Uric Acid Spherulites in the Reflector Layer of Firefly Light Organ

    Science.gov (United States)

    Goh, King-Siang; Sheu, Hwo-Shuenn; Hua, Tzu-En; Kang, Mei-Hua; Li, Chia-Wei

    2013-01-01

    Background In firefly light organs, reflector layer is a specialized tissue which is believed to play a key role for increasing the bioluminescence intensity through reflection. However, the nature of this unique tissue remains elusive. In this report, we investigated the role, fine structure and nature of the reflector layer in the light organ of adult Luciola cerata. Principal Findings Our results indicated that the reflector layer is capable of reflecting bioluminescence, and contains abundant uric acid. Electron microscopy (EM) demonstrated that the cytosol of the reflector layer's cells is filled with densely packed spherical granules, which should be the uric acid granules. These granules are highly regular in size (∼700 nm in diameter), and exhibit a radial internal structure. X-ray diffraction (XRD) analyses revealed that an intense single peak pattern with a d-spacing value of 0.320 nm is specifically detected in the light organ, and is highly similar to the diffraction peak pattern and d-spacing value of needle-formed crystals of monosodium urate monohydrate. However, the molar ratio evaluation of uric acid to various cations (K+, Na+, Ca2+ and Mg2+) in the light organ deduced that only a few uric acid molecules were in the form of urate salts. Thus, non-salt uric acid should be the source of the diffraction signal detected in the light organ. Conclusions In the light organ, the intense single peak diffraction signal might come from a unique needle-like uric acid form, which is different from other known structures of non-salt uric acid form. The finding of a radial structure in the granules of reflector layer implies that the spherical uric acid granules might be formed by the radial arrangement of needle-formed packing matter. PMID:23441187

  7. Firefly bioluminescent assay of ATP in the presence of ATP extractant by using liposomes.

    Science.gov (United States)

    Kamidate, Tamio; Yanashita, Kenji; Tani, Hirofumi; Ishida, Akihiko; Notani, Mizuyo

    2006-01-01

    Liposomes containing phosphatidylcholine (PC) and cholesterol (Chol) were applied to the enhancer for firefly bioluminescence (BL) assay for ATP in the presence of cationic surfactants using as an extractant for the release of ATP from living cells. Benzalkonium chloride (BAC) was used as an ATP extractant. However, BAC seriously inhibited the activity of luciferase, thus resulting in the remarkable decrease in the sensitivity of the BL assay for ATP. On the other hand, we found that BAC was associated with liposomes to form cationic liposomes containing BAC. The association rate of BAC with liposomes was faster than that of BAC with luciferase. As a result, the inhibitory effect of BAC on luciferase was eliminated in the presence of liposomes. In addition, cationic liposomes thus formed enhanced BL emission. BL measurement conditions were optimized in terms of liposome charge type, liposome size, and total concentration of PC and Chol. ATP can be sensitively determined without dilution of analytical samples by using liposomes. The detection limit of ATP with and without liposomes was 100 amol and 25 fmol in aqueous ATP standard solutions containing 0.06% BAC, respectively. The method was applied to the determination of ATP in Escherichia coli extracts. The BL intensity was linear from 4 x 10(4) to 1 x 10(7) cells mL(-1) in the absence of liposomes. On the other hand, the BL intensity was linear from 4 x 10(3) to 4 x 10(6) cells mL(-1) in the presence of liposomes. The detection limit of ATP in E. coli extracts was improved by a factor of 10 via use of liposomes.

  8. Molecular basis for the high-affinity binding and stabilization of firefly luciferase by PTC124

    Science.gov (United States)

    Auld, Douglas S.; Lovell, Scott; Thorne, Natasha; Lea, Wendy A.; Maloney, David J.; Shen, Min; Rai, Ganesha; Battaile, Kevin P.; Thomas, Craig J.; Simeonov, Anton; Hanzlik, Robert P.; Inglese, James

    2010-01-01

    Firefly luciferase (FLuc), an ATP-dependent bioluminescent reporter enzyme, is broadly used in chemical biology and drug discovery assays. PTC124 (Ataluren; (3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid) discovered in an FLuc-based assay targeting nonsense codon suppression, is an unusually potent FLuc-inhibitor. Paradoxically, PTC124 and related analogs increase cellular FLuc activity levels by posttranslational stabilization. In this study, we show that FLuc inhibition and stabilization is the result of an inhibitory product formed during the FLuc-catalyzed reaction between its natural substrate, ATP, and PTC124. A 2.0 Å cocrystal structure revealed the inhibitor to be the acyl-AMP mixed-anhydride adduct PTC124-AMP, which was subsequently synthesized and shown to be a high-affinity multisubstrate adduct inhibitor (MAI; KD = 120 pM) of FLuc. Biochemical assays, liquid chromatography/mass spectrometry, and near-attack conformer modeling demonstrate that formation of this novel MAI is absolutely dependent upon the precise positioning and reactivity of a key meta-carboxylate of PTC124 within the FLuc active site. We also demonstrate that the inhibitory activity of PTC124-AMP is relieved by free coenzyme A, a component present at high concentrations in luciferase detection reagents used for cell-based assays. This explains why PTC124 can appear to increase, instead of inhibit, FLuc activity in cell-based reporter gene assays. To our knowledge, this is an unusual example in which the “off-target” effect of a small molecule is mediated by an MAI mechanism. PMID:20194791

  9. Firefly algorithm versus genetic algorithm as powerful variable selection tools and their effect on different multivariate calibration models in spectroscopy: A comparative study

    Science.gov (United States)

    Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

    2017-01-01

    For the first time, a new variable selection method based on swarm intelligence namely firefly algorithm is coupled with three different multivariate calibration models namely, concentration residual augmented classical least squares, artificial neural network and support vector regression in UV spectral data. A comparative study between the firefly algorithm and the well-known genetic algorithm was developed. The discussion revealed the superiority of using this new powerful algorithm over the well-known genetic algorithm. Moreover, different statistical tests were performed and no significant differences were found between all the models regarding their predictabilities. This ensures that simpler and faster models were obtained without any deterioration of the quality of the calibration.

  10. Phylogeny of fireflies (Coleoptera: Lampyridae) inferred from mitochondrial 16S ribosomal DNA, with references to morphological and ethological traits

    Institute of Scientific and Technical Information of China (English)

    LI Xueyan; YANG Shuang; XIE Meng; LIANG Xingcai

    2006-01-01

    We sequenced partial mitochondrial 16S ribosomal DNA (16S rDNA) of 18 firefly species from Southwest of China.Combined with homologous sequences previously reported, phylogenetic trees including Japanese, Korean and Chinese species were reconstructed by neighbor-joining, maximum parsimony and Bayesian methods. All reconstructions agree on most nodes of the trees. Monophyly of Lampyridae is not supported because Rhagophthalmus ohbai in Rhagophthalmidae is included within it. Lamprigera, a genus placed unreliably in Lampyrinae, shows a close relationship to Amydetinae. Monophyly of Luciolinae is not supported because Pristolycus sagulatus (Lampyrinae) is included within it. In the Luciolinae, monophyly of Curtos and Hotaria is well established, respectively, but both morphological and molecular data continue to indicate that Luciola is not monophyletic and its subdivision is indeed necessary. Within the Lampyrinae, both Pyrocoelia and Diaphanes are not monophyletic, but monophyly of Pyrocoelia + Diaphanes is well supported. Phylogeny of Diaphanes is discussed for the first time. Generic placement of a newly discovered species (Diaphanes pectinealis Li et Liang)sharing some characters of Pyrocoelia and Diaphanes challenges the delimitation of these two similar genera. With references to the firefly mating systems, we suggest that more emphases should be placed on those sexually selected characters such as antennal structure in taxonomy of Lampyridae.

  11. Firefly Luciferase-Based Sequential Bioluminescence Resonance Energy Transfer (BRET)-Fluorescence Resonance Energy Transfer (FRET) Protease Assays.

    Science.gov (United States)

    Branchini, Bruce

    2016-01-01

    We describe here the preparation of ratiometric luminescent probes that contain two well-separated emission peaks produced by a sequential bioluminescence resonance energy transfer (BRET)-fluorescence resonance energy transfer (FRET) process. The probes are single soluble fusion proteins consisting of a thermostable firefly luciferase variant that catalyzes yellow-green (560 nm maximum) bioluminescence and a red fluorescent protein covalently labeled with a near-Infrared fluorescent dye. The two proteins are connected by a decapeptide containing a protease recognition site specific for factor Xa, thrombin, or caspase 3. The rates of protease cleavage of the fusion protein substrates were monitored by recording emission spectra and plotting the change in peak ratios over time. Detection limits of 0.41 nM for caspase 3, 1.0 nM for thrombin, and 58 nM for factor Xa were realized with a scanning fluorometer. This method successfully employs an efficient sequential BRET-FRET energy transfer process based on firefly luciferase bioluminescence to assay physiologically important protease activities and should be generally applicable to the measurement of any endoprotease lacking accessible cysteine residues.

  12. Large-scale protein-protein interaction analysis in Arabidopsis mesophyll protoplasts by split firefly luciferase complementation.

    Directory of Open Access Journals (Sweden)

    Jian-Feng Li

    Full Text Available Protein-protein interactions (PPIs constitute the regulatory network that coordinates diverse cellular functions. There are growing needs in plant research for creating protein interaction maps behind complex cellular processes and at a systems biology level. However, only a few approaches have been successfully used for large-scale surveys of PPIs in plants, each having advantages and disadvantages. Here we present split firefly luciferase complementation (SFLC as a highly sensitive and noninvasive technique for in planta PPI investigation. In this assay, the separate halves of a firefly luciferase can come into close proximity and transiently restore its catalytic activity only when their fusion partners, namely the two proteins of interest, interact with each other. This assay was conferred with quantitativeness and high throughput potential when the Arabidopsis mesophyll protoplast system and a microplate luminometer were employed for protein expression and luciferase measurement, respectively. Using the SFLC assay, we could monitor the dynamics of rapamycin-induced and ascomycin-disrupted interaction between Arabidopsis FRB and human FKBP proteins in a near real-time manner. As a proof of concept for large-scale PPI survey, we further applied the SFLC assay to testing 132 binary PPIs among 8 auxin response factors (ARFs and 12 Aux/IAA proteins from Arabidopsis. Our results demonstrated that the SFLC assay is ideal for in vivo quantitative PPI analysis in plant cells and is particularly powerful for large-scale binary PPI screens.

  13. The function of Hox and appendage-patterning genes in the development of an evolutionary novelty, the Photuris firefly lantern.

    Science.gov (United States)

    Stansbury, Matthew S; Moczek, Armin P

    2014-05-01

    Uncovering the mechanisms underlying the evolution of novel traits is a central challenge in biology. The lanterns of fireflies are complex traits that lack even remote homology to structures outside luminescent beetle families. Representing unambiguous novelties by the strictest definition, their developmental underpinnings may provide clues to their origin and offer insights into the mechanisms of innovation in developmental evolution. Lanterns develop within the context of abdominal Hox expression domains, and we hypothesized that lantern formation may be instructed in part by these highly conserved transcription factors. We show that transcript depletion of Abdominal-B in Photuris fireflies results in extensive disruption of the adult lantern, suggesting that the evolution of adult lanterns involved the acquisition of a novel regulatory role for this Hox gene. Using the same approach, we show that the Hox gene abdominal-A may control important secondary aspects of lantern development. Lastly, we hypothesized that lantern evolution may have involved the recruitment of dormant abdominal appendage-patterning domains; however, transcript depletion of two genes, Distal-less and dachshund, suggests that they do not contribute to lantern development. Our results suggest that complex novelties can arise within the confines of ancestral regulatory landscapes through acquisition of novel targets without compromising ancestral functions.

  14. An Efficient Multi-path Routing Algorithm Based on Hybrid Firefly Algorithm for Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    K. Kumaravel

    2015-05-01

    Full Text Available Wireless Mesh Network (WMN uses the latest technology which helps in providing end users a high quality service referred to as the Internet’s “last mile”. Also considering WMN one of the most important technologies that are employed is multicast communication. Among the several issues routing which is significantly an important issue is addressed by every WMN technologies and this is done during the process of data transmission. The IEEE 802.11s Standard entails and sets procedures which need to be followed to facilitate interconnection and thus be able to devise an appropriate WMN. There has been introduction of several protocols by many authors which are mainly devised on the basis of machine learning and artificial intelligence. Multi-path routing may be considered as one such routing method which facilitates transmission of data over several paths, proving its capabilities as a useful strategy for achieving reliability in WMN. Though, multi-path routing in any manner cannot really guarantee deterministic transmission. As here there are multiple paths available for enabling data transmission from source to destination node. The algorithm that had been employed before in the studies conducted did not take in to consideration routing metrics which include energy aware metrics that are used for path selection during transferring of data. The following study proposes use of the hybrid multipath routing algorithm while taking in to consideration routing metrics which include energy, minimal loss for efficient path selection and transferring of data. Proposed algorithm here has two phases. In the first phase prim’s algorithm has been proposed so that in networks route discovery may be possible. For the second one the Hybrid firefly algorithm which is based on harmony search has been employed for selection of the most suitable and best through proper analysis of metrics which include energy awareness and minimal loss for every path that has

  15. Monitoring immediate-early gene expression through firefly luciferase imaging of HRS/J hairless mice

    Directory of Open Access Journals (Sweden)

    Geusz Michael E

    2003-08-01

    Full Text Available Abstract Background Gene promoters fused to the firefly luciferase gene (luc are useful for examining gene regulation in live transgenic mice and they provide unique views of functioning organs. The dynamics of gene expression in cells and tissues expressing luciferase can be observed by imaging this enzyme's bioluminescent oxidation of luciferin. Neural pathways involved in specific behaviors have been identified by localizing expression of immediate-early genes such as c-fos. A transgenic mouse line with luc controlled by the human c-fos promoter (fos::luc has enabled gene expression imaging in brain slice cultures. To optimize imaging of immediate-early gene expression throughout intact mice, the present study examined fos::luc mice and a second transgenic mouse containing luc controlled by the human cytomegalovirus immediate-early gene 1 promoter and enhancer (CMV::luc. Because skin pigments and hair can significantly scatter light from underlying structures, the two transgenic lines were crossed with a hairless albino mouse (HRS/J to explore which deep structures could be imaged. Furthermore, live anesthetized mice were compared with overdosed mice. Results Bioluminescence imaging of anesthetized mice over several weeks corresponded with expression patterns in mice imaged rapidly after a lethal overdose. Both fos::luc and CMV::luc mice showed quantifiable bright bioluminescence in ear, nose, paws, and tail whether they were anesthetized or overdosed. CMV::luc and fos::luc neonates had bioluminescence patterns similar to those of adults, although intensity was significantly higher in neonates. CMV::luc mice crossed with HRS/J mice had high expression in bone, claws, head, pancreas, and skeletal muscle, but less in extremities than haired CMV::luc mice. Imaging of brain bioluminescence through the neonatal skull was also practical. By imaging luciferin autofluorescence it was clear that substrate distribution did not restrict bioluminescence

  16. Optimal overlayer inspired by Photuris firefly improves light-extraction efficiency of existing light-emitting diodes.

    Science.gov (United States)

    Bay, Annick; André, Nicolas; Sarrazin, Michaël; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

    2013-01-14

    In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is described. The purpose of this overlayer is to improve light extraction into air from the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp. The actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. This two-dimensional pattern contrasts other designs by its unusual profile, its larger dimensions and the fact that it can be tailored to an existing diode design rather than requiring a complete redesign of the diode geometry. The gain of light extraction reaches values up to 55% with respect to the reference unprocessed LED.

  17. A dual-color far-red to near-infrared firefly luciferin analogue designed for multiparametric bioluminescence imaging.

    Science.gov (United States)

    Jathoul, Amit P; Grounds, Helen; Anderson, James C; Pule, Martin A

    2014-11-24

    Red-shifted bioluminescent emitters allow improved in vivo tissue penetration and signal quantification, and have led to the development of beetle luciferin analogues that elicit red-shifted bioluminescence with firefly luciferase (Fluc). However, unlike natural luciferin, none have been shown to emit different colors with different luciferases. We have synthesized and tested the first dual-color, far-red to near-infrared (nIR) emitting analogue of beetle luciferin, which, akin to natural luciferin, exhibits pH dependent fluorescence spectra and emits bioluminescence of different colors with different engineered Fluc enzymes. Our analogue produces different far-red to nIR emission maxima up to λ(max)=706 nm with different Fluc mutants. This emission is the most red-shifted bioluminescence reported without using a resonance energy transfer acceptor. This improvement should allow tissues to be more effectively probed using multiparametric deep-tissue bioluminescence imaging.

  18. From Nonlinear Optimization to Convex Optimization through Firefly Algorithm and Indirect Approach with Applications to CAD/CAM

    Directory of Open Access Journals (Sweden)

    Akemi Gálvez

    2013-01-01

    Full Text Available Fitting spline curves to data points is a very important issue in many applied fields. It is also challenging, because these curves typically depend on many continuous variables in a highly interrelated nonlinear way. In general, it is not possible to compute these parameters analytically, so the problem is formulated as a continuous nonlinear optimization problem, for which traditional optimization techniques usually fail. This paper presents a new bioinspired method to tackle this issue. In this method, optimization is performed through a combination of two techniques. Firstly, we apply the indirect approach to the knots, in which they are not initially the subject of optimization but precomputed with a coarse approximation scheme. Secondly, a powerful bioinspired metaheuristic technique, the firefly algorithm, is applied to optimization of data parameterization; then, the knot vector is refined by using De Boor’s method, thus yielding a better approximation to the optimal knot vector. This scheme converts the original nonlinear continuous optimization problem into a convex optimization problem, solved by singular value decomposition. Our method is applied to some illustrative real-world examples from the CAD/CAM field. Our experimental results show that the proposed scheme can solve the original continuous nonlinear optimization problem very efficiently.

  19. A Novel RSSI Prediction Using Imperialist Competition Algorithm (ICA), Radial Basis Function (RBF) and Firefly Algorithm (FFA) in Wireless Networks

    Science.gov (United States)

    Goudarzi, Shidrokh; Haslina Hassan, Wan; Abdalla Hashim, Aisha-Hassan; Soleymani, Seyed Ahmad; Anisi, Mohammad Hossein; Zakaria, Omar M.

    2016-01-01

    This study aims to design a vertical handover prediction method to minimize unnecessary handovers for a mobile node (MN) during the vertical handover process. This relies on a novel method for the prediction of a received signal strength indicator (RSSI) referred to as IRBF-FFA, which is designed by utilizing the imperialist competition algorithm (ICA) to train the radial basis function (RBF), and by hybridizing with the firefly algorithm (FFA) to predict the optimal solution. The prediction accuracy of the proposed IRBF–FFA model was validated by comparing it to support vector machines (SVMs) and multilayer perceptron (MLP) models. In order to assess the model’s performance, we measured the coefficient of determination (R2), correlation coefficient (r), root mean square error (RMSE) and mean absolute percentage error (MAPE). The achieved results indicate that the IRBF–FFA model provides more precise predictions compared to different ANNs, namely, support vector machines (SVMs) and multilayer perceptron (MLP). The performance of the proposed model is analyzed through simulated and real-time RSSI measurements. The results also suggest that the IRBF–FFA model can be applied as an efficient technique for the accurate prediction of vertical handover. PMID:27438600

  20. The application of Firefly algorithm in an Adaptive Emergency Evacuation Centre Management (AEECM) for dynamic relocation of flood victims

    Science.gov (United States)

    ChePa, Noraziah; Hashim, Nor Laily; Yusof, Yuhanis; Hussain, Azham

    2016-08-01

    Flood evacuation centre is defined as a temporary location or area of people from disaster particularly flood as a rescue or precautionary measure. Gazetted evacuation centres are normally located at secure places which have small chances from being drowned by flood. However, due to extreme flood several evacuation centres in Kelantan were unexpectedly drowned. Currently, there is no study done on proposing a decision support aid to reallocate victims and resources of the evacuation centre when the situation getting worsens. Therefore, this study proposes a decision aid model to be utilized in realizing an adaptive emergency evacuation centre management system. This study undergoes two main phases; development of algorithm and models, and development of a web-based and mobile app. The proposed model operates using Firefly multi-objective optimization algorithm that creates an optimal schedule for the relocation of victims and resources for an evacuation centre. The proposed decision aid model and the adaptive system can be applied in supporting the National Security Council's respond mechanisms for handling disaster management level II (State level) especially in providing better management of the flood evacuating centres.

  1. Recombinant Pseudorabies Virus (PRV Expressing Firefly Luciferase Effectively Screened for CRISPR/Cas9 Single Guide RNAs and Antiviral Compounds

    Directory of Open Access Journals (Sweden)

    Yan-Dong Tang

    2016-03-01

    Full Text Available A Pseudorabies virus (PRV variant has emerged in China since 2011 that is not protected by commercial vaccines, and has not been well studied. The PRV genome is large and difficult to manipulate, but it is feasible to use clustered, regularly interspaced short palindromic repeats (CRISPR/Cas9 technology. However, identification of single guide RNA (sgRNA through screening is critical to the CRISPR/Cas9 system, and is traditionally time and labor intensive, and not suitable for rapid and high throughput screening of effective PRV sgRNAs. In this study, we developed a recombinant PRV strain expressing firefly luciferase and enhanced green fluorescent protein (EGFP as a reporter virus for PRV-specific sgRNA screens and rapid evaluation of antiviral compounds. Luciferase activity was apparent as soon as 4 h after infection and was stably expressed through 10 passages. In a proof of the principle screen, we were able to identify several PRV specific sgRNAs and confirmed that they inhibited PRV replication using traditional methods. Using the reporter virus, we also identified PRV variants lacking US3, US2, and US9 gene function, and showed anti-PRV activity for chloroquine. Our results suggest that the reporter PRV strain will be a useful tool for basic virology studies, and for developing PRV control and prevention measures.

  2. Application of Firefly Algorithm in Optimization of Chemical Production Process%萤火虫算法在化工过程优化中的应用

    Institute of Scientific and Technical Information of China (English)

    常晓萍; 杜文芳; 王凌; 何学甫

    2014-01-01

    近些年以来,以萤火虫算法为代表的群智能优化算法由于具有强大的寻优功能而得到了广泛的应用。在化工生产的过程中,采用萤火虫算法和Matlab语言对实际问题进行优化的同时还采用了苯-甲苯闪蒸过程对其进行了仿真计算。仿真结果表明,气相产物中苯的产量在有效的调节温度、压力以及分流系数的条件下能够达到最大,不仅实现了苯-甲苯闪蒸过程的最优化,同时还充分证明了在解决化工生产过程的优化问题上采用萤火虫算法是有效的。%In recent years, the swarm intelligence optimization algorithm represented by the firefly algorithm with powerful optimization seeking function has been widely used. In the process of chemical production, the actual problems are optimized by firefly algorithm and Matlab language, at the same time, and the simulation calculation is carried out by benzene-toluene flash process. The simulation results show that the output of benzene in the gaseous phase products can achieve maximum under the condition of effective regulation of temperature, pressure, and shunt coefficient, which not only realized the optimization of benzene-toluene flash process, but also fully demonstrated that it's effective to solve the optimization problem in the process of chemical production with the firefly algorithm.

  3. 一种混沌多样性控制的萤火虫优化算法%A firefly algorithm with chaotic diversity control

    Institute of Scientific and Technical Information of China (English)

    徐华丽; 苏守宝; 严仍荣; 马艳

    2014-01-01

    To overcome the disadvantage of premature convergence in the firefly algorithm , a firefly algorithm based on chaos diversity control (CDFA ) was proposed .Applying chaotic mapping ,CDFA achieved an initial firefly population that is high quality and uniformly distributed ;it then disturbed some individuals with low fitness values by chaotic mapping in the process of the search so as to keep the group's activity and reduce the possibility of falling into local optimum ;meanw hile , in order to increase the diversity of the population , the proposed algorithm used the physical reflection theory to control the position of the firefly outside the borders .Experimental results of bench mark functions show that CDFA can effectively improve the ability of the global search and local exploitation and has a better optimization precision and convergence rate than the basic FA .%针对基本萤火虫算法存在早熟停滞现象,提出了一种混沌多样性控制的萤火虫优化算法。运用混沌映射产生均匀分布的萤火虫初始位置,获得质量较好的初始解;在搜索过程中对适应值低的部分萤火虫进行混沌扰动,以保持群体活性,减小陷入局部最优的可能性;同时利用真实物理反弹理论对超越边界萤火虫位置进行控制,提高种群的多样性。用标准测试函数测试,实验结果表明,该算法能有效地提高了算法的全局搜索和局部开发能力,寻优精度和收敛速度明显提高。

  4. Gender on the raggedy edge of the 'Verse : En studie av maskulinitet, femininitet och våld i Joss Whedons Firefly och Serenity

    OpenAIRE

    Geijer, Linnéa, Alexandra

    2015-01-01

    Abstract/Sammanfattning Syftet med detta arbete är att med en narratologisk metod undersöka hur femininitet och maskulinitet representeras i relation till våld i serien Firefly och filmen Serenity. Detta görs med fokus på huvudkaraktärerna Malcolm ’Mal’ Reynolds och River Tam. Som teoretisk grund används teorier om och kring representation, stereotyper, genussystemet, samt maskulinitet och våld. Våldet undersöks utifrån tre aspekter, hur karaktärerna utsätts för våld, hur de använder sig av ...

  5. TDDFT Study of the Electronic Structure, Absorption and Emission Spectra of the Light Emitters of the Amazing Firefly Bioluminescence and Solvation Effects on the Spectra

    Institute of Scientific and Technical Information of China (English)

    REN,Ai-Min; GUO,Jing-Fu; FENG,Ji-Kang; ZOU,Lu-Yi; LI,Zhong-Wei; GODDARD,John,David

    2008-01-01

    The ground and excited state properties of luciferin (LH2) and oxyluciferin (OxyLH2), the bioluminescent chemicals in the firefly, have been characterized using density functional theory (DFT) and time dependent DFT (TDDFT) methods. The effects of solvation on the electronic absorption and emission spectra of luciferin and oxyluciferin were predicted with a self-consistent isodensity polarized continuum model of the solvent using TDDFT.The S0→S1 vertical excitation energies in the gas phase and in water were obtained. Optimizations of the excited state geometries permitted the first predictions of the fluorescence spectra for these biologically important molecules. Shifts in both of the absorption and emission spectra on proceeding from the gas phase to aqueous solution were also predicted.

  6. Firefly Femmes Fatales

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik; Queiroz, Joao; El-Hani, Charbel

    2009-01-01

    Artiklen undersöger kommunikations- og deceptionsstrategier hos ildfluer og beskriver dem i Peirceanske termer. Specielt argumenteres det at Peirces begreb for udsagn - dicisign - er nödvendigt for beskrivelsen af disse fänomener......Artiklen undersöger kommunikations- og deceptionsstrategier hos ildfluer og beskriver dem i Peirceanske termer. Specielt argumenteres det at Peirces begreb for udsagn - dicisign - er nödvendigt for beskrivelsen af disse fänomener...

  7. Firefly Femmes Fatales

    DEFF Research Database (Denmark)

    Stjernfelt, Frederik; Queiroz, Joao; El-Hani, Charbel

    2009-01-01

    Artiklen undersöger kommunikations- og deceptionsstrategier hos ildfluer og beskriver dem i Peirceanske termer. Specielt argumenteres det at Peirces begreb for udsagn - dicisign - er nödvendigt for beskrivelsen af disse fänomener...

  8. Optimization of soil water characteristic curves parameters by modified firefly algorithm%基于改进萤火虫算法的土壤水分特征曲线参数优化

    Institute of Scientific and Technical Information of China (English)

    付强; 蒋睿奇; 王子龙; 李天霄

    2015-01-01

    Inacurate estimation of parameters of soil water characteristic curves can cause simulation results of soil moisture models. This paper introduced firefly algorithm to solve the nonlinear fitting problem of soil water characteristic curve model (Van Genuchten) parameters. In the algorithm principle, the force of attraction and light are based on the distance between different individuals, based on which the whole population is divided into a number of subgroups at the beginning, and every sub-population gathered around local optimal value. All sub-population can optimize at the same time, improving the efficiency, and the global optimal solution is found between all these local optimal values. Compared with the particle swarm algorithm, the firefly algorithm does not use perception such as individual best position, the global optimal position to control calculation, which avoids the potential defects such as premature convergence. In addition, the algorithm dose not set speed for fireflies, which avoids the problem that the speed exceeds a threshold. But, when firefly individuals approach the optimal value, it is likely to move longer than the distance between the individual and the optimal value, therefore resulting in the jump-over of the optimal value and reaching the other side. If this situation appears repeatedly, it will affect the convergence speed and accuracy of algorithm. So in this paper we turned the fixed step length into a variant step length that changed according to the between-firefly distance, and thus the firefly algorithm had a better global optimization ability at the beginning and rapidly found the position adjacent to the optimal value region, in the end it had a good local search ability and was able to find the overall optimal value. The test samples came from test field of College of Water Conservancy and Architecture in Northeast Agricultural University(126°45'32″E、45°44'41″N), China. Black soil in Harbin area can represent the

  9. Strategy of mutual compensation of green and red mutants of firefly luciferase identifies a mutation of the highly conservative residue E457 with a strong red shift of bioluminescence.

    Science.gov (United States)

    Koksharov, Mikhail I; Ugarova, Natalia N

    2013-11-01

    Bioluminescence spectra of firefly luciferases demonstrate highly pH-sensitive spectra changing the color from green to red light when pH is lowered from alkaline to acidic. This reflects a change of ratio of the green and red emitters in the bimodal spectra of bioluminescence. We show that the mutations strongly stabilizing green (Y35N) or red (H433Y) emission compensate each other leading to the WT color of firefly luciferase. We further used this compensating ability of Y35N to search for strong red-shifting mutations in the C-domain of firefly luciferase by random mutagenesis. The discovered mutation E457K substantially increased the contribution of the red emitter and caused a 12 nm red shift of the green emitter as well. E457 is highly conservative not only in beetle luciferases but also in a whole ANL superfamily of adenylating enzymes and forms a conservative structural hydrogen bond with V471. Our results suggest that the removal of this hydrogen bond only mildly affects luciferase properties and that most of the effect of E457K is caused by the introduction of positive charge. E457 forms a salt bridge with R534 in most ANL enzymes including pH-insensitive luciferases which is absent in pH-sensitive firefly luciferases. The mutant A534R shows that this salt bridge is not important for pH-sensitivity but considerably improves in vivo thermostability. Although E457 is located far from the oxyluciferin-binding site, the properties of the mutant E457K suggest that it affects color by influencing the AMP binding.

  10. Time courses and time-resolved spectra of firefly bioluminescence initiated by two methods of ATP injection and photolysis of caged ATP.

    Science.gov (United States)

    Yanagisawa, Yuki; Kageyama, Takeshi; Wada, Naohisa; Tanaka, Masatoshi; Ohno, Shin-Ya

    2013-01-01

    The time-dependent characteristics of firefly bioluminescence initiated by manual injection of adenosine triphosphate (ATP) into buffer solution containing luciferin (Ln), luciferase (Luc) and Mg(2+) were measured with a resolution of 10 ms, and compared with those obtained by photolysis of caged ATP. The time course depends on pH; both rise and decay rates decrease when pH is lowered from 7.8 to 6.8. In contrast, the parameter λ in the kinetic formula related to diffusion of ATP is almost independent of pH. The pH dependence of the time course of bioluminescence can be explained by the same pH tendency as the rate of ATP binding at the active site of Luc. The time-resolved spectra can be decomposed into two Gaussian components with maxima at 2.2 and 2.0 eV. At pH 7.8, the band at 2.2 eV is more intense than that at 2.0 eV for all three concentration conditions. At lower pH, the band at 2.2 eV becomes weaker than that at 2.0 eV. The intensity ratio of the 2.0 and 2.2 eV bands is constant for duration time of 600 s for both injection and photolysis experiments, and the above conclusions are unaffected by the concentration ratio [Ln]/[Luc].

  11. 基于萤火虫算法的神经网络CPI预测模型%Neural Network Prediction Model of CPI Using Firefly Algorithm Training

    Institute of Scientific and Technical Information of China (English)

    彭伟; 汪镭

    2012-01-01

    This paper uses firefly algorithm to train neural network model using for predicting consumer price index It specifies the model constructing process, train method and simulation By collecting data from Statistics Bureau, the papers sets up an algorithm model in matlab and calculate the simulating result It proves to be good in accuracy and satisfies the predicting standard The work will be positive in the macroeconomic policy decision%通过萤火虫算法来训练神经网络模型,将模型运用于消费者物价指数(CPI)的预测.阐述模型的建立,训练优化和仿真方法.收集国家统计局的统计数据,通过matlab建立算法模型,得到仿真结果.实验证明模型具有较高的预测精度,满足预测要求,对于未来我国的经济调控具有一定意义.

  12. Comparison of human optimized bacterial luciferase, firefly luciferase, and green fluorescent protein for continuous imaging of cell culture and animal models

    Science.gov (United States)

    Close, Dan M.; Hahn, Ruth E.; Patterson, Stacey S.; Baek, Seung J.; Ripp, Steven A.; Sayler, Gary S.

    2011-01-01

    Bioluminescent and fluorescent reporter systems have enabled the rapid and continued growth of the optical imaging field over the last two decades. Of particular interest has been noninvasive signal detection from mammalian tissues under both cell culture and whole animal settings. Here we report on the advantages and limitations of imaging using a recently introduced bacterial luciferase (lux) reporter system engineered for increased bioluminescent expression in the mammalian cellular environment. Comparison with the bioluminescent firefly luciferase (Luc) system and green fluorescent protein system under cell culture conditions demonstrated a reduced average radiance, but maintained a more constant level of bioluminescent output without the need for substrate addition or exogenous excitation to elicit the production of signal. Comparison with the Luc system following subcutaneous and intraperitoneal injection into nude mice hosts demonstrated the ability to obtain similar detection patterns with in vitro experiments at cell population sizes above 2.5 × 104 cells but at the cost of increasing overall image integration time. PMID:21529093

  13. An optimal light-extracting overlayer, inspired by the lantern of a Photuris firefly, to improve the external efficiency of existing light-emitting diodes

    CERN Document Server

    Bay, Annick; Sarrazin, Michael; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

    2012-01-01

    Actual light emission diodes (LED) have most often good internal efficiencies but poor external efficiencies due to total internal reflection at the air interface. In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is investigated. The purpose of this overlayer is to improve light extraction into air, after the photons have been generated in the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp., described by Bay et al. : a surface with an asymmetrical triangular profile (a "factory-roof" shape), developed on the scale of a few micrometers, thus somewhat larger than usually suggested in the related literature. The profile of the overlayer corrugated surface of the coating film was copied from the natural model. Yet, the actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. The optimization proc...

  14. Firefly algorithm optimized fuzzy PID controller for AGC of multi-area multi-source power systems with UPFC and SMES

    Directory of Open Access Journals (Sweden)

    Pratap Chandra Pradhan

    2016-03-01

    Full Text Available In this paper, a Firefly Algorithm (FA optimized fuzzy PID controller is proposed for Automatic Generation Control (AGC of multi-area multi-source power system. Initially, a two area six units power system is used and the gains of the fuzzy PID controller are optimized employing FA optimization technique using an ITAE criterion. The superiority of the proposed FA optimized fuzzy PID controller has been demonstrated by comparing the results with some recently published approaches such as optimal control and Differential Evolution (DE optimized PID controller for the identical interconnected power system. Then, physical constraints such as Time Delay (TD, reheat turbine and Generation Rate Constraint (GRC are included in the system model and the superiority of FA is demonstrated by comparing the results over DE, Gravitational Search Algorithm (GSA and Genetic Algorithm (GA optimization techniques for the same interconnected power system. Additionally, a Unified Power Flow Controller (UPFC is placed in the tie-line and Superconducting Magnetic Energy Storage (SMES units are considered in both areas. Simulation results show that the system performances are improved significantly with the proposed UPFC and SMES units. Sensitivity analysis of the system is performed by varying the system parameters and operating load conditions from their nominal values. It is observed that the optimum gains of the proposed controller need not be reset even if the system is subjected to wide variation in loading condition and system parameters. Finally, the effectiveness of the proposed controller design is verified by considering different types of load patterns.

  15. Studies on South-east Asian fireflies: Abscondita, a new genus with details of life history, flashing patterns and behaviour of Abs. chinensis (L.) and Abs. terminalis (Olivier) (Coleoptera: Lampyridae: Luciolinae).

    Science.gov (United States)

    Ballantyne, Lesley; Fu, Xinhua; Lambkin, Christine; Jeng, Ming-Luen; Faust, Lynn; Wijekoon, M C D; Li, Daiqin; Zhu, Tengfui

    2013-01-01

    Abscondita, a new genus of fireflies from South-east Asia, is described from males and females of Abs. anceyi (Olivier 1883), Abs. cerata (Olivier 1911), Abs. chinensis (L. 1767), Abs. perplexa (Walker 1858), Abs. promelaena (Walker 1858) and Abs. terminalis (Olivier 1883), all transferred from Luciola Laporte. Both L. dubia Olivier 1903 and L. dejeani Gemminger 1870 are synonymised with Luciola perplexa (Walker), and L. aegrota Olivier 1891 and L. melaspis Bourgeois 1909 with L. promelaena Walker. Females are characterised by their bursa plates. Larvae are associated and described for Abs. anceyi (Olivier), Abs. chinensis (L.) and Abs. terminalis (Olivier). Taxonomic issues regarding the identification of species with very similar colouration of pale dorsum and black tipped elytra are addressed and in some cases resolved. A neotype for Luciola chinensis (L.) is erected and Luciola praeusta (Kiesenwetter 1874) is synonymised with L. chinensis (L.). Descriptions of life histories, biology and flashing patterns of populations of Abs. chinensis and Abs. terminalis from central China are included. A bs. terminalis is the first Asian firefly known to possess multiple flash trains where males are documented to display with repeating flash trains.

  16. 基于萤火虫算法的自动化仓储货位优化分配研究%Slotting allocation optimization of automated warehouse based on firefly algorithm

    Institute of Scientific and Technical Information of China (English)

    朱靖; 章瑶易; 贺青

    2016-01-01

    为解决自动化仪表仓储系统货位优化问题,提出一种基于萤火虫算法的仓储货位优化方法,以仓储货位入库的时间为目标函数,利用最小时间法实现货位的最优分配,通过实际的案例,验证了萤火虫算法在立体表库货位优化中的有效性。%In order to solve the problem of the allotting allocation optimization in automated instrument warehouse sys-tem, improve the efficiency of storage system, this paper proposes the warehouse optimization method based on the firefly algorithm, which takes the storage location time as objective function, and adopts least time to achieve optimal allocation.The relevant case analysis verified the effectiveness of firefly algorithm in three-dimensional slotting opti-mization.

  17. Bug City: Ladybugs & Fireflies [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon, including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic…

  18. Bug City: Ladybugs & Fireflies [Videotape].

    Science.gov (United States)

    1998

    "Bug City" is a video series created to help children (grades 1-6) learn about insects and other small critters. All aspects of bug life are touched upon, including body structure, food, habitat, life cycle, mating habits, camouflage, mutualism (symbiosis), adaptations, social behavior, and more. Each program features dramatic…

  19. An improved firefly algorithm for the blocking flow shop scheduling problem%改进的萤火虫算法求解阻塞流水线调度问题

    Institute of Scientific and Technical Information of China (English)

    郭丽萍; 李向涛; 谷文祥; 殷明浩

    2013-01-01

    为了提高阻塞流水线调度问题的求解性能,提出了一种改进的萤火虫算法来求解阻塞流水线调度问题.首先,提出一种离散机制把个体的实数编码形式转换成离散的作业序列,从而使算法能够应用于离散问题求解;其次,设计一种双重初始化方法,并将NEH启发式方法应用到初始化中来,使算法有一个较优的初始化环境,提高初始种群的解的质量;此外,重新设计了算法中个体的移动方式来增大搜索域;最后,以一定概率对种群中的个体进行局部搜索,加强算法的局部搜索性能.通过对Taillard数据集中部分实例进行求解,实验结果验证了新算法的有效性.%In order to improve the solving performance of the blocking flow shop scheduling problem, the researcher proposes to examine an improved firefly algorithm. Firstly, a discrete mechanism was proposed to convert the real coded form of individuals to discrete job sequences, so that the algorithm could be used to deal with discrete problems. Secondly, a double-initialization method was designed and the NEH ( Nawaz-Enscore-Ham) heuristic method was applied to the initialization, which provided a superior initial environment and improved the quality of the solution of the initial population. In addition, the research paper focused on redesigning the movement pattern of individuals to enhance the search space. Finally, a local search algorithm was applied to individuals with a certain probability, for the purpose of enhancing the ability to search locally. The improved firefly algorithm was then tested utilizing the Taillard datasets, and the results verified the effectiveness of the new algorithm.

  20. Finding hotspot topics using link analysis and clustering blog topics w ith firefly algorithm%基于链接和萤火虫算法聚类博文发现热点话题

    Institute of Scientific and Technical Information of China (English)

    王雅琳; 陆向艳; 钟诚

    2015-01-01

    针对已有的基于链接分析的热点发现方法存在准确度较低、易受作弊链接影响、易产生主题漂移现象等问题,利用复杂网络簇结构具有高度主题相关的特点,提出一种融合应用链接分析和萤火虫算法聚类博文的热点话题发现算法。以博文页面为节点,与博文内容相同或相关的链接作为边,根据博文及博主的相关属性,综合评定页面权重,建立博客话题模型;运用萤火虫算法对博文进行聚类获得聚类中心,按页面权重将聚类中心从大到小排序,形成热点话题热度排行。实验结果表明,该方法能够发现精度更高、数量更多的博客热点话题。%To address the problem that the existing hotspot topics finding methods use link analysis to obtain the results ,which results in lower precision ,vulnerability to cheating links and emerging topic drift phenomenon ,a hotspot topic discovery algo‐rithm using link analysis and firefly algorithm to cluster Blog articles was proposed based on the feature of highly relevant subject of cluster structures in complex networks .Blog article pages and the links of the same or relative Blog articles were represented by nodes and edges respectively ,and the weights of Blog article pages were evaluated using the relative attributes of Blog articles and Bloggers ,and then the Blog topic model was established .Firefly algorithm was used to cluster the Blog articles to form the cluster centers ,and these cluster centers were sorted using the weights of the Blog article pages to obtain the ranking of hotspot topics .The experimental results show that the proposed method can find more Blog hotspot topics with higher precision .

  1. Construction of Firefly Luciferase Expression Vector Driven by Mouse WNT1 Gene Promoter%小鼠WNT1基因启动子控制的萤火虫荧光素酶表达载体的构建

    Institute of Scientific and Technical Information of China (English)

    秦大妮; 周泽民; 沈惠平; 余章斌; 韩树萍

    2012-01-01

    目的 构建小鼠WNT1基因启动子控制的萤火虫荧光索酶表达载体,并检测其在P19细胞中的表达.方法 采用PCR方法获得WNT1基因启动子最小功能单位和3'UTR区域在内的DNA片段.双酶切后插入到pGL3-Basic载体中构成重组表达载体,使萤火虫荧光素酶报告基因的表达受WNT1启动子控制.将构建的重组表达载体或pGL3-Basic载体分别与内参质粒pRL-SV40(表达海肾荧光素酶)共转染P19细胞,24h后用双荧光检测试剂盒测定萤火虫荧光素酶及海肾荧光素酶活性.结果 重组表达载体经双酶切及测序鉴定证明构建正确,空白对照组(荧光强度比值:2.8204±0.2944)与对照组(荧光强度比值:3.0508±0.3037)及WNT-3' UTR突变组(荧光强度比值:51.4758±0.9837)比较,差异均有统计学意义(Pa<0.001),该重组表达载体在P19细胞特异性高表达萤火虫荧光素酶.结论 成功构建小鼠WNT1基因启动子控制的萤火虫荧光素酶表达载体,并检测到该载体在P19细胞的特异性表达.%Objective To construct firefly luciferase expression vector driven by mouse WNT1 gene promoter and determine its expression in PI 9 cell. Methods A fragment including the smallest functional unit of WNT1 gene promoter and 3'UTR regions of the DNA was amplified and inserted into pGL3 - Basic vector which contained a firefly luciferase reporter gene driven by WNT1 promoter. The recombinant vector or pGL3 - Basic vector was co - tranafected together with pRL — cytomegalovirus ( CMV) vector containing renila luciferase reporter gene into P19 ceil. Firefly and reniia luciferase activities were analyzed 24 h later by using of dual luciferase reporter assay system. Results Restriction enzyme double digestion and sequencing analysis confirmed correct construction of recombinant expression vector containing WNT1 promoter controlled firefly luciferase reporter gene. The study compared the blank control group (fluorescence intensity ratio;2. 820 4

  2. Interconversion of ketoprofen recognition in firefly luciferase-catalyzed enantioselective thioesterification reaction using from Pylocoeria miyako (PmL) and Hotaria parvura (HpL) just by mutating two amino acid residues.

    Science.gov (United States)

    Kato, Dai-ichiro; Hiraishi, Yoshihiro; Maenaka, Mika; Yokoyama, Keisuke; Niwa, Kazuki; Ohmiya, Yoshihiro; Takeo, Masahiro; Negoro, Seiji

    2013-11-01

    We identified the critical amino acid residues for substrate recognition using two firefly luciferases from Pylocoeria miyako (PmL) and Hotaria parvura (HpL), as these two luciferase enzymes exhibit different activities toward ketoprofen. Specifically, PmL can catalyze the apparent enantioselective thioesterification reaction, while HpL cannot. By comparing the amino acid sequences around the active site, we identified two residues (I350 and M397 in PmL and F351 and S398 in HpL) that were different between the two enzymes, and the replacement of these amino acids resulted in changing the ketoprofen recognition pattern. The inactive HpL was converted to the active enzyme toward ketoprofen and vice versa for PmL. These residues also affected the enantioselectivity toward ketoprofen; however, the bioluminescent color was not affected. In addition, using molecular dynamics calculations, the replacement of these two amino acids induced changes in the state of hydrogen bonding between ketoprofen and the S349 side chain through the active site water. As S349 is not considered to influence color tuning, these changes specifically caused the differences in ketoprofen recognition in the enzyme.

  3. 萤火虫算法求解具有人员柔性的 FSP 问题*%Application of Firefly Algorithm in Flow Shop Scheduling Problem with Personnel Flexibility

    Institute of Scientific and Technical Information of China (English)

    吴小康; 叶春明

    2014-01-01

    Personnel Flexibility Flow Shop Scheduling Problem is more realistic and practical than classical FSP .First , the personnel‐machine diagram is proposed .Second ,it extends the PM matrix and FI index to measure the personnel flexibil‐ity .After improving the classical FSP model ,it is used to solve the Car system problems and practical example through two steps by firefly algorithm at last .All of these prove that it is effective and feasible .%具有人员柔性的FS P问题较之于经典的FS P问题更具有现实性和应用前景。首先提出人员‐机器关系图并引出度量人员柔性的PM矩阵和FI指数,然后对传统FSP模型进行补充和改进,以萤火虫算法为工具,通过人员模式的选择和对应模式下的问题寻优两大步骤进行求解并利用经典Car类问题进行仿真,最后将其应用于实例求解。仿真和实例求解结果都充分说明了算法的有效性和可行性。

  4. Owl, werewolf, firefly: Animal trace narrator

    Directory of Open Access Journals (Sweden)

    Raquel Wandelli Loth

    2016-06-01

    Full Text Available The route by a network of narrators from different eras finds a trace of animality in the look and in the flâneur writing, since Restif de La Bretonne proposed, in the eighteenth century, the similarity between the reporter/narrator and a night bird. This track permits that one proposes the category of the owl-narrator, which puts into practice an inhuman method of looking at the shadow areas of the cities. Here considered as narratives of the dark, this cartography runs several textualities intertwined by the desire to see what is beneath the everyday life – from Bretonne and Mercier, through Poe, Baudelaire, João do Rio and arriving to Clarice Lispector. Sometimes, the owl narrative disappears to resurge in every city where there is a stubborn wanderer who overcomes the invisibility spot on the human eye. The crowds go ahead inattentively, overshadowed by the proliferation of signs and advertisements, they march to the future without looking back. The owl does not; it retains the time to envision the disappearance of singularities and to foresee what the today story points out as more clandestine. As claims Benjamin (1994, p. 231, “thinking not only includes the movement of ideas, but also their immobilization”. The walk by the early writer-reporters allows us to consider that the owl-flâneur inaugurates not only himself, but also this kind of narrative based on a poetic of looking to the rubble. The physical roaming characterizes it, but does not determine the narrative, as it does not determine the trip, the inner displacement. Mostly, the impulse to see the unknown awakens other obscured powers, reintegrating them to the perception of the urban movements and driving the narrative to walk, to hear, to smell, to feel. In the nightly flight by means of a pivoting look, literature announces the survivals that do not cease to disappear in front of the contemporary life.

  5. Stream eclipse mapping with 'fire-flies'

    CERN Document Server

    Bridge, C M; Cropper, M; Ramsay, G; Hakala, Pasi; Cropper, Mark; Ramsay, Gavin

    2003-01-01

    We apply a new method of eclipse mapping to the light curves of eclipsing polars. The technique aims to locate the bright emission associated with the accretion stream, using a technique that makes the fewest prior assumptions about the location of the accretion stream material. We have obtained data of EP Dra and HU Aqr with the S-Cam 2 superconducting tunnel junction camera using the William Herschel Telescope. The location of emission regions in both systems show that previously assumed trajectories are consistent with those found using our technique. Most of the emission is located in a region where we expect material to be confined to magnetic field lines, particularly for HU Aqr, while there appears to be less emission from where we conventionally expect material to follow a ballistic trajectory from the L1-point.

  6. Immobilized Bioluminescent Reagents in Flow Injection Analysis.

    Science.gov (United States)

    Nabi, Abdul

    Available from UMI in association with The British Library. Bioluminescent reactions exhibits two important characteristics from an analytical viewpoint; they are selective and highly sensitive. Furthermore, bioluminescent emissions are easily measured with a simple flow-through detector based on a photomultiplier tube and the rapid and reproducible mixing of sample and expensive reagent is best achieved by a flow injection manifold. The two most important bioluminescent systems are the enzyme (luciferase)/substrate (luciferin) combinations extracted from fireflies (Photinus pyralis) and marine bacteria (Virio harveyi) which requires ATP and NAD(P)H respectively as cofactors. Reactions that generate or consume these cofactors can also be coupled to the bioluminescent reaction to provide assays for a wide range of clinically important species. A flow injection manifold for the study of bioluminescent reactions is described, as are procedures for the extraction, purification and immobilization of firefly and bacterial luciferase and oxidoreductase. Results are presented for the determination of ATP using firefly system and the determination of other enzymes and substrates participating in ATP-converting reactions e.g. creatine kinase, ATP-sulphurylase, pyruvate kinase, creatine phosphate, pyrophosphate and phophoenolypyruvate. Similarly results are presented for the determination of NAD(P)H, FMN, FMNH_2 and several dehydrogenases which produce NAD(P)H and their substrates, e.g. alcohol, L-lactate, L-malate, L-glutamate, Glucose-6-phosphate and primary bile acid.

  7. Optogenetic control of ATP release

    Science.gov (United States)

    Lewis, Matthew A.; Joshi, Bipin; Gu, Ling; Feranchak, Andrew; Mohanty, Samarendra K.

    2013-03-01

    Controlled release of ATP can be used for understanding extracellular purinergic signaling. While coarse mechanical forces and hypotonic stimulation have been utilized in the past to initiate ATP release from cells, these methods are neither spatially accurate nor temporally precise. Further, these methods cannot be utilized in a highly effective cell-specific manner. To mitigate the uncertainties regarding cellular-specificity and spatio-temporal release of ATP, we herein demonstrate use of optogenetics for ATP release. ATP release in response to optogenetic stimulation was monitored by Luciferin-Luciferase assay (North American firefly, photinus pyralis) using luminometer as well as mesoscopic bioluminescence imaging. Our result demonstrates repetitive release of ATP subsequent to optogenetic stimulation. It is thus feasible that purinergic signaling can be directly detected via imaging if the stimulus can be confined to single cell or in a spatially-defined group of cells. This study opens up new avenue to interrogate the mechanisms of purinergic signaling.

  8. Codon optimization of genes for efficient protein expression in mammalian cells by selection of only preferred human codons.

    Science.gov (United States)

    Inouye, Satoshi; Sahara-Miura, Yuiko; Sato, Jun-ichi; Suzuki, Takahiro

    2015-05-01

    A simple design method for codon optimization of genes to express a heterologous protein in mammalian cells is described. Codon optimization was performed by choosing only codons preferentially used in humans and with over 60% GC content, and the method was named the "preferred human codon-optimized method." To test our simple rule for codon optimization, the preferred human codon-optimized genes for six proteins containing photoproteins (aequorin and clytin II) and luciferases (Gaussia luciferase, Renilla luciferase, and firefly luciferases from Photinus pyralis and Luciola cruciata) were chemically synthesized and transiently expressed in Chinese hamster ovary-K1 cells. All preferred human codon-optimized genes showed higher luminescence activity than the corresponding wild-type genes. Our simple design method could be used to improve protein expression in mammalian cells efficiently. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Evaluation of the performance of different firefly algorithms to the ...

    African Journals Online (AJOL)

    3Department of Electrical Power and Machines, Faculty of Engineering, Ain ... DOI: http://dx.doi.org/10.4314/ijest.v9i2.1. 1. ... In this paper, these three variants are applied to solve the nonlinear ELD problem. ..... Learning and Computing, Vol.

  10. Laboratory procedures manual for the firefly luciferase assay for adenosine triphosphate (ATP)

    Science.gov (United States)

    Chappelle, E. W.; Picciolo, G. L.; Curtis, C. A.; Knust, E. A.; Nibley, D. A.; Vance, R. B.

    1975-01-01

    A manual on the procedures and instruments developed for the adenosine triphosphate (ATP) luciferase assay is presented. Data cover, laboratory maintenance, maintenance of bacterial cultures, bacteria measurement, reagents, luciferase procedures, and determination of microbal susceptibility to antibiotics.

  11. The Dance of Fireflies. Orality and Transmission in Virgilio Sieni’s Work

    Directory of Open Access Journals (Sweden)

    Rossella Mazzaglia

    2011-12-01

    Full Text Available This essay investigates the meaning of  contemporary dance transmission through an analysis of the creative and pedagogical work lead by the Tuscan artist Virgilio Sieni. Adopting the concept of orality, the author goes through his career, from the early stages of his education to his present activity both with his dance company and with the Accademia il gesto, particularly focusing on recent accomplishments and projects. On the one hand, she articulates on the process of dissolution of the dance tradition that his work witnesses, by extending references and motivations to a vaster context concerning the art and the human cultural heritage (with particular emphasis on the Italian one. On the other, she shows the consequent redefinition of the meaning, methods and targets of transmission in a dialectical confrontation with contemporaneity, intended as an attitude towards one’s own present and not only as a chronological phase of history. Readapting Didi-Huberamn’s politics of survival perspective, the author further recognizes, in the aesthetic and human encounter among people of different background and age, the way Sieni draws the present near the past, the individual identity near the collective one, through the transmission of his aesthetic gesture.

  12. Systematic review of the firefly genus Scissicauda (Coleoptera, Lampyridae, Amydetinae) from Brazil

    Science.gov (United States)

    Silveira, Luiz Felipe Lima Da; Mermudes, José Ricardo M.; Bocakova, Milada

    2016-01-01

    Abstract The Amydetinae genus Scissicauda McDermott, 1964 is reviewed and redescribed. We describe Scissicauda balena sp. n. from Brazil as new, and provide illustrations of the structural features and a key to species of both sexes. PMID:27006595

  13. Working and reference check list for fireflies of Melanesia (Coleoptera: Lampyridae: Luciolinae).

    Science.gov (United States)

    Ballantyne, Lesley A; Lloyd, James E

    2013-11-13

    Twenty-three species of Lampyridae (fifteen of them new) collected during the 1969-70 Alpha Helix scientific expedition to New Guinea are now characterized by both behavioural and taxonomic data. For ease of identification, relocation of specimens, and location of all pertinent literature this check list is presented.

  14. Inhibition of firefly luciferase by general anesthetics: effect on in vitro and in vivo bioluminescence imaging.

    Directory of Open Access Journals (Sweden)

    Marleen Keyaerts

    Full Text Available UNLABELLED: Bioluminescence imaging is routinely performed in anesthetized mice. Often isoflurane anesthesia is used because of its ease of use and fast induction/recovery. However, general anesthetics have been described as important inhibitors of the luciferase enzyme reaction. AIM: To investigate frequently used mouse anesthetics for their direct effect on the luciferase reaction, both in vitro and in vivo. MATERIALS AND METHODS: isoflurane, sevoflurane, desflurane, ketamine, xylazine, medetomidine, pentobarbital and avertin were tested in vitro on luciferase-expressing intact cells, and for non-volatile anesthetics on intact cells and cell lysates. In vivo, isoflurane was compared to unanesthetized animals and different anesthetics. Differences in maximal photon emission and time-to-peak photon emission were analyzed. RESULTS: All volatile anesthetics showed a clear inhibitory effect on the luciferase activity of 50% at physiological concentrations. Avertin had a stronger inhibitory effect of 80%. For ketamine and xylazine, increased photon emission was observed in intact cells, but this was not present in cell lysate assays, and was most likely due to cell toxicity and increased cell membrane permeability. In vivo, the highest signal intensities were measured in unanesthetized mice and pentobarbital anesthetized mice, followed by avertin. Isoflurane and ketamine/medetomidine anesthetized mice showed the lowest photon emission (40% of unanesthetized, with significantly longer time-to-peak than unanesthetized, pentobarbital or avertin-anesthetized mice. We conclude that, although strong inhibitory effects of anesthetics are present in vitro, their effect on in vivo BLI quantification is mainly due to their hemodynamic effects on mice and only to a lesser extent due to the direct inhibitory effect.

  15. Taxonomy of the Brazilian firefly Cladodes illigeri (Coleoptera, Lampyridae: morphology and new records

    Directory of Open Access Journals (Sweden)

    Luiz Felipe Lima da Silveira

    2015-09-01

    Full Text Available ABSTRACT Cladodes illigeri (Kirby, 1818 is redescribed, and can be distinguished by the following features: color pattern overall black, paired spots and elytral margins pale yellow; pygidium bisinuate, posterior angles rounded, as long as median margin; and aedeagus with phallus 1/3 shorter than the parameres, which are sinuated apically. Cladodes lamellicornis (Motschulsky, 1854 is proposed as a junior synomym of C. illigeri. New records from the Atlantic Rainforest and illustrations for structural features are provided.

  16. Experimental optimization of the FireFly 600 photovoltaic off-grid system.

    Energy Technology Data Exchange (ETDEWEB)

    Boyson, William Earl; Orozco, Ron (Energia Total, Ltd., Corrales, NM); Ralph, Mark E.; Brown, Marlene Laura; King, David L.; Hund, Thomas D.

    2003-10-01

    A comprehensive evaluation and experimental optimization of the FireFly{trademark} 600 off-grid photovoltaic system manufactured by Energia Total, Ltd. was conducted at Sandia National Laboratories in May and June of 2001. This evaluation was conducted at the request of the manufacturer and addressed performance of individual system components, overall system functionality and performance, safety concerns, and compliance with applicable codes and standards. A primary goal of the effort was to identify areas for improvement in performance, reliability, and safety. New system test procedures were developed during the effort.

  17. A novel high-throughput vaccinia virus neutralization assay and preexisting immunity in populations from different geographic regions in China.

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    Full Text Available BACKGROUND: Pre-existing immunity to Vaccinia Tian Tan virus (VTT resulting from a large vaccination campaign against smallpox prior to the early 1980s in China, has been a major issue for application of VTT-vector based vaccines. It is essential to establish a sensitive and high-throughput neutralization assay to understand the epidemiology of Vaccinia-specific immunity in current populations in China. METHODOLOGY/PRINCIPAL FINDINGS: A new anti-Vaccinia virus (VACV neutralization assay that used the attenuated replication-competent VTT carrying the firefly luciferase gene of Photinus pyralis (rTV-Fluc was established and standardized for critical parameters that included the choice of cell line, viral infection dose, and the infection time. The current study evaluated the maintenance of virus-specific immunity after smallpox vaccination by conducting a non-randomized, cross-sectional analysis of antiviral antibody-mediated immune responses in volunteers examined 30-55 years after vaccination. The rTV-Fluc neutralization assay was able to detect neutralizing antibodies (NAbs against Vaccinia virus without the ability to differentiate strains of Vaccinia virus. We showed that the neutralizing titers measured by our assay were similar to those obtained by the traditional plaque reduction neutralization test (PRNT. Using this assay, we found a low prevalence of NAb to VTT (7.6% in individuals born before 1980 from Beijing and Anhui provinces in China, and when present, anti-VTT NAb titers were low. No NAbs were detected in all 222 samples from individuals born after 1980. There was no significant difference observed for titer or prevalence by gender, age range and geographic origin. CONCLUSION: A simplified, sensitive, standardized, reproducible, and high-throughput assay was developed for the quantitation of NAbs against different Vaccinia strains. The current study provides useful insights for the future development of VTT-based vaccination in

  18. A Novel High-Throughput Vaccinia Virus Neutralization Assay and Preexisting Immunity in Populations from Different Geographic Regions in China

    Science.gov (United States)

    Liu, Qiang; Huang, Weijin; Nie, Jianhui; Zhu, Rong; Gao, Dongying; Song, Aijing; Meng, Shufang; Xu, Xuemei; Wang, Youchun

    2012-01-01

    Background Pre-existing immunity to Vaccinia Tian Tan virus (VTT) resulting from a large vaccination campaign against smallpox prior to the early 1980s in China, has been a major issue for application of VTT-vector based vaccines. It is essential to establish a sensitive and high-throughput neutralization assay to understand the epidemiology of Vaccinia-specific immunity in current populations in China. Methodology/Principal Findings A new anti-Vaccinia virus (VACV) neutralization assay that used the attenuated replication-competent VTT carrying the firefly luciferase gene of Photinus pyralis (rTV-Fluc) was established and standardized for critical parameters that included the choice of cell line, viral infection dose, and the infection time. The current study evaluated the maintenance of virus-specific immunity after smallpox vaccination by conducting a non-randomized, cross-sectional analysis of antiviral antibody-mediated immune responses in volunteers examined 30–55 years after vaccination. The rTV-Fluc neutralization assay was able to detect neutralizing antibodies (NAbs) against Vaccinia virus without the ability to differentiate strains of Vaccinia virus. We showed that the neutralizing titers measured by our assay were similar to those obtained by the traditional plaque reduction neutralization test (PRNT). Using this assay, we found a low prevalence of NAb to VTT (7.6%) in individuals born before 1980 from Beijing and Anhui provinces in China, and when present, anti-VTT NAb titers were low. No NAbs were detected in all 222 samples from individuals born after 1980. There was no significant difference observed for titer or prevalence by gender, age range and geographic origin. Conclusion A simplified, sensitive, standardized, reproducible, and high-throughput assay was developed for the quantitation of NAbs against different Vaccinia strains. The current study provides useful insights for the future development of VTT-based vaccination in Beijing and Anhui

  19. A novel high-throughput vaccinia virus neutralization assay and preexisting immunity in populations from different geographic regions in China.

    Science.gov (United States)

    Liu, Qiang; Huang, Weijin; Nie, Jianhui; Zhu, Rong; Gao, Dongying; Song, Aijing; Meng, Shufang; Xu, Xuemei; Wang, Youchun

    2012-01-01

    Pre-existing immunity to Vaccinia Tian Tan virus (VTT) resulting from a large vaccination campaign against smallpox prior to the early 1980s in China, has been a major issue for application of VTT-vector based vaccines. It is essential to establish a sensitive and high-throughput neutralization assay to understand the epidemiology of Vaccinia-specific immunity in current populations in China. A new anti-Vaccinia virus (VACV) neutralization assay that used the attenuated replication-competent VTT carrying the firefly luciferase gene of Photinus pyralis (rTV-Fluc) was established and standardized for critical parameters that included the choice of cell line, viral infection dose, and the infection time. The current study evaluated the maintenance of virus-specific immunity after smallpox vaccination by conducting a non-randomized, cross-sectional analysis of antiviral antibody-mediated immune responses in volunteers examined 30-55 years after vaccination. The rTV-Fluc neutralization assay was able to detect neutralizing antibodies (NAbs) against Vaccinia virus without the ability to differentiate strains of Vaccinia virus. We showed that the neutralizing titers measured by our assay were similar to those obtained by the traditional plaque reduction neutralization test (PRNT). Using this assay, we found a low prevalence of NAb to VTT (7.6%) in individuals born before 1980 from Beijing and Anhui provinces in China, and when present, anti-VTT NAb titers were low. No NAbs were detected in all 222 samples from individuals born after 1980. There was no significant difference observed for titer or prevalence by gender, age range and geographic origin. A simplified, sensitive, standardized, reproducible, and high-throughput assay was developed for the quantitation of NAbs against different Vaccinia strains. The current study provides useful insights for the future development of VTT-based vaccination in Beijing and Anhui provinces of China.

  20. Frequency and phase synchronization in large groups: Low dimensional description of synchronized clapping, firefly flashing, and cricket chirping

    Science.gov (United States)

    Ott, Edward; Antonsen, Thomas M.

    2017-05-01

    A common observation is that large groups of oscillatory biological units often have the ability to synchronize. A paradigmatic model of such behavior is provided by the Kuramoto model, which achieves synchronization through coupling of the phase dynamics of individual oscillators, while each oscillator maintains a different constant inherent natural frequency. Here we consider the biologically likely possibility that the oscillatory units may be capable of enhancing their synchronization ability by adaptive frequency dynamics. We propose a simple augmentation of the Kuramoto model which does this. We also show that, by the use of a previously developed technique [Ott and Antonsen, Chaos 18, 037113 (2008)], it is possible to reduce the resulting dynamics to a lower dimensional system for the macroscopic evolution of the oscillator ensemble. By employing this reduction, we investigate the dynamics of our system, finding a characteristic hysteretic behavior and enhancement of the quality of the achieved synchronization.

  1. Excited-state intermolecular proton transfer of firefly luciferin V. Direct proton transfer to fluoride and other mild bases.

    Science.gov (United States)

    Presiado, Itay; Gepshtein, Rinat; Erez, Yuval; Huppert, Dan

    2011-07-07

    We studied the direct proton transfer (PT) from electronically excited D-luciferin to several mild bases. The fluorescence up-conversion technique is used to measure the rise and decay of the fluorescence signals of the protonated and deprotonated species of D-luciferin. From a base concentration of 0.25 M or higher the proton transfer rates to the fluoride, dihdyrogen phosphate or acetate bases are fast and comparable. The fluorescence signals are nonexponential and complex. We suggest that the fastest decay component arises from a direct proton transfer process from the hydroxyl group of D-luciferin to the mild base. The proton donor and acceptor molecules form an ion pair prior to photoexcitation. Upon photoexcitation solvent rearrangement occurs on a 1 ps time-scale. The PT reaction time constant is ∼2 ps for all three bases. A second decay component of about 10 ps is attributed to the proton transfer in a contact pair bridged by one water molecule. The longest decay component is due to both the excited-state proton transfer (ESPT) to the solvent and the diffusion-assisted PT process between a photoacid and a base pair positioned remotely from each other prior to photoexcitation.

  2. Recombinant Pseudorabies Virus (PRV) Expressing Firefly Luciferase Effectively Screened for CRISPR/Cas9 Single Guide RNAs and Antiviral Compounds

    OpenAIRE

    2016-01-01

    A Pseudorabies virus (PRV) variant has emerged in China since 2011 that is not protected by commercial vaccines, and has not been well studied. The PRV genome is large and difficult to manipulate, but it is feasible to use clustered, regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology. However, identification of single guide RNA (sgRNA) through screening is critical to the CRISPR/Cas9 system, and is traditionally time and labor intensive, and not suitable for rapid and hi...

  3. Sensitive Dual Color in vivo Bioluminescence Imaging Using a New Red Codon Optimized Firefly Luciferase and a Green Click Beetle Luciferase

    Science.gov (United States)

    2011-04-01

    expression of the bacterial luciferase gene cassette ( lux ) in a mammalian cell line. PLoS One 5: e12441. 6. Cheong WF, Prahl SA, Welch AJ (1990) A...Chemistry, Connecticut College, New London, Connecticut, United States of America Abstract Background: Despite a plethora of bioluminescent reporter genes ...challenging. This is partly attributable to the lack of optimization of cell reporter gene expression as well as too much spectral overlap of the color- coupled

  4. A Hybrid Method Based on Singular Spectrum Analysis, Firefly Algorithm, and BP Neural Network for Short-Term Wind Speed Forecasting

    Directory of Open Access Journals (Sweden)

    Yuyang Gao

    2016-09-01

    Full Text Available With increasing importance being attached to big data mining, analysis, and forecasting in the field of wind energy, how to select an optimization model to improve the forecasting accuracy of the wind speed time series is not only an extremely challenging problem, but also a problem of concern for economic forecasting. The artificial intelligence model is widely used in forecasting and data processing, but the individual back-propagation artificial neural network cannot always satisfy the time series forecasting needs. Thus, a hybrid forecasting approach has been proposed in this study, which consists of data preprocessing, parameter optimization and a neural network for advancing the accuracy of short-term wind speed forecasting. According to the case study, in which the data are collected from Peng Lai, a city located in China, the simulation results indicate that the hybrid forecasting method yields better predictions compared to the individual BP, which indicates that the hybrid method exhibits stronger forecasting ability.

  5. Forging Partnerships to Improve Teaching: A Science Specialist School Shows a Way Forward

    Science.gov (United States)

    Hingley, Phil; Jarvis, Tina

    2009-01-01

    In September 2005, Beaumont Leys Secondary School gained Specialist Science status. As part of this new role the secondary school decided to support its ten feeder primary schools, which were close enough geographically to allow both daytime and twilight activities. Having gathered information about their in-service needs, Beaumont Leys offered a…

  6. Bioluminescence.

    Science.gov (United States)

    Jones, M. Gail

    1993-01-01

    Describes bioluminescence and the chemistry of how it occurs. Presents information for conducting the following classroom activities: (1) firefly mimic; (2) modeling deep-sea fish; (3) sea fireflies; and (4) the chemistry of light. (PR)

  7. Further studies on south eastern Asian Luciolinae: 1. Sclerotia Ballantyne, a new genus of fireflies with back swimming larvae 2. Triangulara Pimpasalee, a new genus from Thailand (Coleoptera: Lampyridae).

    Science.gov (United States)

    Ballantyne, Lesley A; Lambkin, Christine L; Luan, Xin; Boontop, Yuvarin; Nak-Eiam, Sorasak; Pimpasalee, Suttisan; Silalom, Sommyot; Thancharoen, Anchana

    2016-09-23

    Sclerotia Ballantyne gen. nov. is established for seven species. Sclerotia aquatilis (Thancharoen, 2007), Scl. brahmina (Bourgeois, 1890), Scl. carinata (Gorham, 1880), Scl. flavida (Hope, 1845), Scl. seriata (Olivier, 1891), and Scl. substriata (Gorham, 1880) are transferred from Luciola Laporte. Sclerotia fui sp. nov. from China is described as new. Luciola cingulata Olivier, 1885 is synonymised with Luciola substriata Gorham. Luciola formosana Pic, 1916 is removed from synonymy with Luciola substriata and newly synonymised with Luciola flavida (Hope). Males are characterised by linear elytral punctation, a set of three sclerites surrounding the aedeagal sheath and a light organ in ventrite 7 with emarginated anterior margin. Associated females lack bursa plates. Larvae associated for three species are back swimmers, having heavily sclerotised exoskeleton and a metapneustic respiratory system. Males and associated females are keyed. Analysis of molecular evidence for Chinese populations of three species indicates monophyly of Sclerotia Ballantyne gen. nov. and distinct separation from other genera.Triangulara Pimpasalee gen. nov. is described from Tri. frontoflava Pimpasalee gen. et sp. nov. from Thailand. It is superficially similar to Sclerotia gen. nov. but larger, and specimens in collections appear to have been confused with the similarly coloured Scl. substriata (Gorham) comb. nov. Males differ in having an elongate triangular light organ in ventrite 7 and are without sclerites around the aedeagal sheath. Larvae are not reliably associated but may be aquatic.

  8. Dicty_cDB: Contig-U11930-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available :none) Hyphomonas neptunium ATCC 15444... 71 2e-10 D25416_1( D25416 |pid:none) Firefly mRNA for luciferase, ...stonia eutropha H16 chromosom... 67 4e-09 D25415_1( D25415 |pid:none) Firefly mRN

  9. Nanowire Photovoltaic Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Firefly, in collaboration with Rochester Institute of Technology, proposes an STTR program for the development of a space solar cell having record efficiency...

  10. Hiilgav, aga... vol.2 / Alar Niineväli

    Index Scriptorium Estoniae

    Niineväli, Alar

    2008-01-01

    Ameerika telesarjad, mis on heatasemelised, kuid tootjate poolt liiga vara ära lõpetatud, enamasti kasumlikkusest lähtudes : "Action" (1999), "Now and Again" (1999), "Firefly" (2002), "Freaks and Geeks" (1999), "Undeclared" (2001)

  11. Analytical Applications of Bioluminescence and Chemiluminescence

    Science.gov (United States)

    Chappelle, E. W. (Editor); Picciolo, G. L. (Editor)

    1975-01-01

    Bioluminescence and chemiluminescence studies were used to measure the amount of adenosine triphosphate and therefore the amount of energy available. Firefly luciferase - luciferin enzyme system was emphasized. Photometer designs are also considered.

  12. In a series of studies some years ago, RE Young and his colleagues ...

    African Journals Online (AJOL)

    spamer

    the eye photophores on the ventral surface of the eyeball of the Japanese firefly squid Watasenia scintillans. ... the central region of the photophore is conducted along the “rods”, each of ... (which measure the intensity of downwelling light;.

  13. Hiilgav, aga... vol.2 / Alar Niineväli

    Index Scriptorium Estoniae

    Niineväli, Alar

    2008-01-01

    Ameerika telesarjad, mis on heatasemelised, kuid tootjate poolt liiga vara ära lõpetatud, enamasti kasumlikkusest lähtudes : "Action" (1999), "Now and Again" (1999), "Firefly" (2002), "Freaks and Geeks" (1999), "Undeclared" (2001)

  14. Wide Bandgap Nanostructured Space Photovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Firefly, in collaboration with Rochester Institute of Technology, proposes an STTR program for the development of a wide-bandgap GaP-based space solar cell capable...

  15. Cycloheximide- and puromycin-induced heat resistance : different effects on cytoplasmic and nuclear luciferases

    NARCIS (Netherlands)

    Michels, AA; Kanon, B; Konings, AWT; Bensaude, O; Kampinga, HH

    2000-01-01

    Inhibition of translation can result in cytoprotection against heat shock. The mechanism of this protection has remained elusive so far. Here, the thermoprotective effects of the translation inhibitor cycloheximide (CHX) and puromycin were investigated, using as reporter firefly luciferase localized

  16. Yuki Midorikawa's Dream of Ecstasy between Nostalgia and Utopia——About Fireflies in the Forest by Yuki Midorikawa%衔辛流连怀旧与乌托邦之间(之二)——绿川幸《萤火之森》回望记

    Institute of Scientific and Technical Information of China (English)

    李娜; 陈良菊

    2014-01-01

    《萤火之森》是绿川幸老师又一部美丽的作品:幽婉淡定的文本叙事中,饱含着浑然天成的脉脉温情与屡屡惆怅.动画内容由浅吟低酌的爱情落笔,一面探寻生命的本质,一面澄思人与世界之关系.看似“常规”的外显形式,更是囊括进诸多有关灵魂万物的审美因素.

  17. Crystal structure of native and a mutant of Lampyris turkestanicus luciferase implicate in bioluminescence color shift.

    Science.gov (United States)

    Kheirabadi, Mitra; Sharafian, Zohreh; Naderi-Manesh, Hossein; Heineman, Udo; Gohlke, Ulrich; Hosseinkhani, Saman

    2013-12-01

    Firefly bioluminescence reaction in the presence of Mg(2+), ATP and molecular oxygen is carried out by luciferase. The luciferase structure alterations or modifications of assay conditions determine the bioluminescence color of firefly luciferase. Among different beetle luciferases, Phrixothrix hirtus railroad worm emits either yellow or red bioluminescence color. Sequence alignment analysis shows that the red-emitter luciferase from Phrixothrix hirtus has an additional arginine residue at 353 that is absent in other firefly luciferases. It was reported that insertion of Arg in an important flexible loop350-359 showed changes in bioluminescence color from green to red and the optimum temperature activity was also increased. To explain the color tuning mechanism of firefly luciferase, the structure of native and a mutant (E354R/356R/H431Y) of Lampyris turkestanicus luciferase is determined at 2.7Å and 2.2Å resolutions, respectively. The comparison of structure of both types of Lampyris turkestanicus luciferases reveals that the conformation of this flexible loop is significantly changed by addition of two Arg in this region. Moreover, its surface accessibility is affected considerably and some ionic bonds are made by addition of two positive charge residues. Furthermore, we noticed that the hydrogen bonding pattern of His431 with the flexible loop is changed by replacing this residue with Tyr at this position. Juxtaposition of a flexible loop (residues 351-359) in firefly luciferase and corresponding ionic and hydrogen bonds are essential for color emission.

  18. Efficient in vivo gene transfer to xenotransplanted human skin by lentivirus-mediated, but not by AAV-directed, gene delivery

    DEFF Research Database (Denmark)

    Jakobsen, Maria Vad; Askou, Anne Louise; Dokkedahl, Karin Stenderup

    in a xenotransplanted mouse model. Vector constructs encoding firefly luciferase were packaged in AAV capsids of serotype 1, 2, 5, 6, 8, and 9 and separately administered by intradermal injection in human skin transplants. For all serotypes, live bioimaging demonstrated low levels of transgene expression in the human......Skin is an easily accessible organ, and therapeutic gene transfer to skin remains an attractive alternative for treatment of skin diseases. We compared the potential usefulness of various serotypes of recombinant AAV vectors and lentiviral vectors for gene transfer to human skin...... skin graft, and firefly luciferase expression was observed primarily in neighboring tissue beneath or surrounding the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin...

  19. Luciferin Amides Enable in Vivo Bioluminescence Detection of Endogenous Fatty Acid Amide Hydrolase Activity.

    Science.gov (United States)

    Mofford, David M; Adams, Spencer T; Reddy, G S Kiran Kumar; Reddy, Gadarla Randheer; Miller, Stephen C

    2015-07-15

    Firefly luciferase is homologous to fatty acyl-CoA synthetases. We hypothesized that the firefly luciferase substrate d-luciferin and its analogs are fatty acid mimics that are ideally suited to probe the chemistry of enzymes that release fatty acid products. Here, we synthesized luciferin amides and found that these molecules are hydrolyzed to substrates for firefly luciferase by the enzyme fatty acid amide hydrolase (FAAH). In the presence of luciferase, these molecules enable highly sensitive and selective bioluminescent detection of FAAH activity in vitro, in live cells, and in vivo. The potency and tissue distribution of FAAH inhibitors can be imaged in live mice, and luciferin amides serve as exemplary reagents for greatly improved bioluminescence imaging in FAAH-expressing tissues such as the brain.

  20. AN ARTIFICIAL FISH SWARM OPTIMIZED FUZZY MRI IMAGE SEGMENTATION APPROACH FOR IMPROVING IDENTIFICATION OF BRAIN TUMOUR

    Directory of Open Access Journals (Sweden)

    R.Jagadeesan

    2013-07-01

    Full Text Available In image processing, it is difficult to detect the abnormalities in brain especially in MRI brain images. Also the tumor segmentation from MRI image data is an important; however it is time consumingwhile carried out by medical specialists. A lot of methods have been proposed to solve MR images problems, quite difficult to develop an automated recognition system which could process on a large information of patient and provide a correct estimation. Hence enhanced k-means and fuzzy c-means with firefly algorithm for a segmentation of brain magnetic resonance images were developed. Thisalgorithm is based on maximum measure of the distance function which is found for cluster center detection process using the Mahalanobis concept. Particularly the firefly algorithm is implemented tooptimize the Fuzzy C-means membership function for better accuracy segmentation process. At the same time the convergence criteria is fixed for the efficient clustering method. The Firefly algorithmparameters are set fixed and they do not adjust by the time. As well Firefly algorithm does not memorize any history of better situation for each firefly and this reasons they travel in any case of it, and they miss their situations. So there is a need of better algorithm that could provide even better solution than the firefly algorithm. To attain this requirement as a proposed work the Artificial Fish Swarm Algorithm to optimize the fuzzy membership function. During surveying of the previous literature, it has been found out that no work has been done in segmentation of brain tumor using AFSA based clustering. In AFSA, artificial fishes for next movement act completely independent from past and next movement is justrelated to current position of artificial fish and its other companions which lead to select best initial centers for the MRI brain tumor segmentation. Experimental results show that presented method has an acceptable performance than the previous method.

  1. Missing The Point: An Exploration of How to Guide Users’ Attention During Cinematic Virtual Reality

    DEFF Research Database (Denmark)

    Nielsen, Lasse T.; Møller, Matias B.; Hartmeyer, Sune D.

    2016-01-01

    Recent technological advances have brought Virtual Reality (VR) into the homes of consumers, and there is a growing interest in bringing cinematic experiences from the screen and into VR. How-ever, cinematic VR limits filmmakers’ ability to effectively guide the audience’s attention. In this pape...... to follow a firefly with their gaze. The results revealed interesting, albeit statistically insignificant, indications that assuming control of the user’s action may negatively influence presence, whereas the firefly was perceived as significantly more helpful....

  2. The application of a photon-counting camera in very sensitive, bioluminescence-enhanced detection systems for protein blotting. Ultrasensitive detection systems for protein blotting and DNA hybridization, II.

    Science.gov (United States)

    Hauber, R; Miska, W; Schleinkofer, L; Geiger, R

    1988-03-01

    A relatively simple, very sensitive bioluminescence-enhanced detection system for protein blots was described recently. This method utilizes antibodies conjugated with alkaline phosphatase. Alkaline phosphatase releases D-luciferin (Photinus pyralis) from D-luciferin-O-phosphate. Liberated D-luciferin reacts with luciferase, ATP and oxygen with light emission. The light produced is measured with a very sensitive photon counting camera (Argus 100), permitting visualization and localization of the alkaline phosphatase-conjugated antibodies on nitrocellulose sheets. Under non-optimized conditions the limit of detection is at present 5 to 500 fg of protein (rabbit immunoglobulin G), corresponding to 30 to 3 amol. The method is therefore 10(5) times more sensitive than other used at present.

  3. Transcriptome analysis reveals candidate genes involved in luciferin metabolism in Luciola aquatilis (Coleoptera: Lampyridae)

    Science.gov (United States)

    Vongsangnak, Wanwipa; Chumnanpuen, Pramote

    2016-01-01

    Bioluminescence, which living organisms such as fireflies emit light, has been studied extensively for over half a century. This intriguing reaction, having its origins in nature where glowing insects can signal things such as attraction or defense, is now widely used in biotechnology with applications of bioluminescence and chemiluminescence. Luciferase, a key enzyme in this reaction, has been well characterized; however, the enzymes involved in the biosynthetic pathway of its substrate, luciferin, remains unsolved at present. To elucidate the luciferin metabolism, we performed a de novo transcriptome analysis using larvae of the firefly species, Luciola aquatilis. Here, a comparative analysis is performed with the model coleopteran insect Tribolium casteneum to elucidate the metabolic pathways in L. aquatilis. Based on a template luciferin biosynthetic pathway, combined with a range of protein and pathway databases, and various prediction tools for functional annotation, the candidate genes, enzymes, and biochemical reactions involved in luciferin metabolism are proposed for L. aquatilis. The candidate gene expression is validated in the adult L. aquatilis using reverse transcription PCR (RT-PCR). This study provides useful information on the bio-production of luciferin in the firefly and will benefit to future applications of the valuable firefly bioluminescence system. PMID:27761329

  4. Method of detecting and counting bacteria in body fluids

    Science.gov (United States)

    Chappelle, E. W.; Picciolo, G. L. (Inventor)

    1973-01-01

    A novel method is reported for determining bacterial levels in urine samples, which method depends on the quantitative determination of bacterial adenosine triphosphate (ATP) in the presence of non-bacterial ATP. After the removal of non-bacterial ATP, the bacterial ATP is released by cell rupture and is measured by an enzymatic bioluminescent assay using an enzyme obtained from the firefly.

  5. 77 FR 44434 - Airworthiness Directives; Various Restricted Category Helicopters

    Science.gov (United States)

    2012-07-30

    ... State University); Firefly Aviation Helicopter Services (previously Erickson Air-Crane Co.); California... Services (previously Erickson Air-Crane Co.); California Department of Forestry; Garlick Helicopters, Inc... (previously Erickson Air-Crane Co.); California Department of Forestry; Garlick Helicopters, Inc.; Global...

  6. The Representation of Authors and Illustrators of Color in School-Based Book Clubs

    Science.gov (United States)

    McNair, Jonda C.

    2008-01-01

    The purpose of this study was to examine Firefly (Preschool) and Seesaw (K-1) Scholastic book club order forms for a period of one year--from September of 2004 through June of 2005--in order to determine which authors and illustrators of children's literature, particularly those of color, were routinely included and excluded. This study was…

  7. Genetic Algoritm Eclipse Mapping

    Science.gov (United States)

    Halevin, A. V.

    In this paper we analyse capabilities of eclipse mapping technique, based on genetic algorithm optimization. To model of accretion disk we used the "fire-flies" conception. This model allows us to reconstruct the distribution of radiating medium in the disk using less number of free parameters than in other methods. Test models show that we can achieve good approximation without optimizing techniques.

  8. The NS3 protein of rice hoja blanca virus suppresses RNA silencing in mammalian cells

    NARCIS (Netherlands)

    Schnettler, E.; Hemmes, J.C.; Goldbach, R.W.; Prins, M.W.

    2008-01-01

    The NS3 protein of the tenuivirus rice hoja blanca virus (RHBV) has previously been shown to represent the viral RNA interference (RNAi) suppressor and is active in both plant and insect cells by binding short interfering RNAs (siRNAs) in vitro. Using a firefly luciferase-based silencing assay it is

  9. Dissecting and Targeting Latent Metastasis

    Science.gov (United States)

    2014-09-01

    cultured in RPMI 1640 medium with 10% FBS and 2 mM L-Glutamine. For lentivirus production, 293T cells were cultured in DME media supplemented with 10...E. et al. Kinetics of regulated protein-protein interactions revealed with firefly luciferase complementation imaging in cells and living animals

  10. 愛知教育大学の学生による訪問科学実験のための生物発光化学発光の化学マジック実験法の検討

    OpenAIRE

    戸谷, 義明

    2006-01-01

    The visiting university students from Aichi University of Education have exhibited the scientific experimental demonstration at various schools and scientific exhibitions since 1997. For the visiting exhibition of the chemical demonstration, "Chemical Magic", the experimental methods in bioluminescence and chemiluminescence were investigated. Five luminescent systems, "Chemilumine-scence of Luminol", "Vargula Bioluminescence", "Firefly Bioluminescence", "Bioluminescence of Photoprotein Aequor...

  11. 21 CFR 864.7040 - Adenosine triphosphate release assay.

    Science.gov (United States)

    2010-04-01

    ... device that measures the release of adenosine triphosphate (ATP) from platelets following aggregation. This measurement is made on platelet-rich plasma using a photometer and a luminescent firefly extract. Simultaneous measurements of platelet aggregation and ATP release are used to evaluate platelet...

  12. Increased Na+/K(+)-pump activity and adenosine triphosphate utilization after compound 48/80-induced histamine secretion from rat mast cells

    DEFF Research Database (Denmark)

    Johansen, Torben; Praetorius, Birger Hans

    1994-01-01

    -production were measured by the bioluminescence technique (firefly lantern) and by measurement of the lactate production under anaerobic conditions (antimycin A, oligomycin), respectively. There was an increased requirement for ATP after the secretory response associated with an increased activity of the Na...

  13. Circular polarization observed in bioluminescence

    NARCIS (Netherlands)

    Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

    1980-01-01

    While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and

  14. IN VIVO BIOLUMINESCENT IMAGING OF SCHWANN CELLS IN A POLY(DL-LACTIDE-epsilon-CAPROLACTONE) NERVE GUIDE

    NARCIS (Netherlands)

    Ma, Ming-San; Van Dam, Gooitzen; Meek, Marcel; Boddeke, Erik; Copray, Sjef

    2009-01-01

    Nerve guides seeded with Schwann cells (SCs) promote axonal regeneration in peripheral nerve lesions. We examined the applicability of bioluminescent imaging (BLI) for monitoring the fate of SCs in nerve guides after implantation. Rat SCs were transfected with the firefly luciferase (Fluc) gene and

  15. International Conference: Fundamentals of Laser Assisted Micro- & Nanotechnologies (FLAMN-07). Workshop: Laser Cleaning and Artworks Conservation (LCAC). St. Petersburg, Russia, 25-28 June 2007. Abstracts

    Science.gov (United States)

    2007-06-28

    fungi, lichens and other biological growth. For removal of patinations from the surface of white marble a Nd:YAG free- running laser (model Smart...Expression plasmid DNA for a firefly luminescence enzyme, luciferase, was injected into tibial muscle and mousse, and then laser-induced shock wave was

  16. [Expression of thermostable recombiant Luciola lateralis luciferase and development of heat-stable pyrosequencing system].

    Science.gov (United States)

    Xu, Shu; Zou, Bingjie; Wang, Jianping; Wu, Haiping; Zhou, Guohua

    2012-06-01

    Pyrosequencing is a tool based on bioluminescence reaction for real-time analyzing DNA sequences. The sensitivity of pyrosequencing mainly depends on luciferase in reaction mixture. However, the instability of pyrosequencing reagents caused by fragile wild Photinus pyralis luciferase (PpL) in conventional pyrosequencing usually leads to unsatisfied results, which limits the application of pyrosequencing. In order to improve the stability of pyrosequencing reagents, the coding sequences of mutant thermostable Luciola lateralis luciferase (rt-LlL) was synthesized, and inserted into the plasmid of pET28a(+) to express the thermostable rt-LlL with a 6 x His-tag in the N terminal. The purified rt-LlL with the molecular mass of 60 kDa was obtained by Ni-affinity chromatography. The specific activity of rt-LlL was determined as 4.29 x 10(10) RLU/mg. Moreover, the thermostability of rt-LlL was investigated, and the results showed that rt-LlL had activity at 50 degrees C, and remained 90% of activity after incubated at 40 degrees C for 25 min. Finally, rt-LlL was used to substitute commercial Photinus pyralis luciferase in conventional pyrosequencing reagent to get thermostable pyrosequencing reagent. Comparing with conventional pyrosequencing reagent, the thermostable pyrosequencing reagent is more stable, and it's activity would not lose when incubated at 37 degrees C for 1 h. This study laid foundation of establishing reliable and stable pyrosequencing system which would be applied in Point-of-Care Testing.

  17. Why aye-ayes see blue.

    Science.gov (United States)

    Melin, Amanda D; Moritz, Gillian L; Fosbury, Robert A E; Kawamura, Shoji; Dominy, Nathaniel J

    2012-03-01

    The capacity for cone-mediated color vision varies among nocturnal primates. Some species are colorblind, having lost the functionality of their short-wavelength-sensitive-1 (SWS1) opsin pigment gene. In other species, such as the aye-aye (Daubentonia madagascariensis), the SWS1 gene remains intact. Recent studies focused on aye-ayes indicate that this gene has been maintained by natural selection and that the pigment has a peak sensitivity (lambda(max)) of 406 nm, which is -20 nm closer to the ultraviolet region of the spectrum than in most primates. The functional significance behind the retention and unusual lambda(max) of this opsin pigment is unknown, and it is perplexing given that all mammals are presumed to be colorblind in the dark. Here we comment on this puzzle and discuss recent findings on the color vision intensity thresholds of terrestrial vertebrates with comparable optics to aye-ayes. We draw attention to the twilight activities of aye-ayes and report that twilight is enriched in short-wavelength (bluish) light. We also show that the intensity of twilight and full moonlight is probably sufficient to support cone-mediated color vision. We speculate that the intact SWS1 opsin pigment gene of aye-ayes is a crepuscular adaptation and we report on the blueness of potential visual targets, such as scent marks and the brilliant blue arils of Ravenala madagascariensis.

  18. Proton mediated control of biochemical reactions with bioelectronic pH modulation

    Science.gov (United States)

    Deng, Yingxin; Miyake, Takeo; Keene, Scott; Josberger, Erik E.; Rolandi, Marco

    2016-04-01

    In Nature, protons (H+) can mediate metabolic process through enzymatic reactions. Examples include glucose oxidation with glucose dehydrogenase to regulate blood glucose level, alcohol dissolution into carboxylic acid through alcohol dehydrogenase, and voltage-regulated H+ channels activating bioluminescence in firefly and jellyfish. Artificial devices that control H+ currents and H+ concentration (pH) are able to actively influence biochemical processes. Here, we demonstrate a biotransducer that monitors and actively regulates pH-responsive enzymatic reactions by monitoring and controlling the flow of H+ between PdHx contacts and solution. The present transducer records bistable pH modulation from an “enzymatic flip-flop” circuit that comprises glucose dehydrogenase and alcohol dehydrogenase. The transducer also controls bioluminescence from firefly luciferase by affecting solution pH.

  19. Reporter gene assay for the quantification of the activity and neutralizing antibody response to TNFα antagonists

    DEFF Research Database (Denmark)

    Lallemand, Christophe; Kavrochorianou, Nadia; Steenholdt, Casper;

    2011-01-01

    relative to Renilla luciferase expression. Thus, results are independent of cell number or differences in cell viability, resulting in intra and inter assay coefficients of variation of 10% or less. Normalization of results relative to the expression of an internal standard also provides a means......A cell-based assay has been developed for the quantification of the activity of TNFa antagonists based on human erythroleukemic K562 cells transfected with a NF¿B regulated firefly luciferase reporter-gene construct. Both drug activity and anti-drug neutralizing antibodies can be quantified...... with a high degree of precision within 2h, and without interference from cytokines and other factors known to activate NF¿B. The assay cells also contain the Renilla luciferase reporter gene under the control of a constitutive promoter that allows TNFa-induced firefly luciferase activity to be normalized...

  20. Reporter gene assay for the quantification of the activity and neutralizing antibody response to TNFα antagonists

    DEFF Research Database (Denmark)

    Lallemand, Christophe; Kavrochorianou, Nadia; Steenholdt, Casper;

    2011-01-01

    relative to Renilla luciferase expression. Thus, results are independent of cell number or differences in cell viability, resulting in intra and inter assay coefficients of variation of 10% or less. Normalization of results relative to the expression of an internal standard also provides a means......A cell-based assay has been developed for the quantification of the activity of TNFα antagonists based on human erythroleukemic K562 cells transfected with a NFκB regulated firefly luciferase reporter-gene construct. Both drug activity and anti-drug neutralizing antibodies can be quantified...... with a high degree of precision within 2h, and without interference from cytokines and other factors known to activate NFκB. The assay cells also contain the Renilla luciferase reporter gene under the control of a constitutive promoter that allows TNFα-induced firefly luciferase activity to be normalized...

  1. Recent advances in swarm intelligence and evolutionary computation

    CERN Document Server

    2015-01-01

    This timely review volume summarizes the state-of-the-art developments in nature-inspired algorithms and applications with the emphasis on swarm intelligence and bio-inspired computation. Topics include the analysis and overview of swarm intelligence and evolutionary computation, hybrid metaheuristic algorithms, bat algorithm, discrete cuckoo search, firefly algorithm, particle swarm optimization, and harmony search as well as convergent hybridization. Application case studies have focused on the dehydration of fruits and vegetables by the firefly algorithm and goal programming, feature selection by the binary flower pollination algorithm, job shop scheduling, single row facility layout optimization, training of feed-forward neural networks, damage and stiffness identification, synthesis of cross-ambiguity functions by the bat algorithm, web document clustering, truss analysis, water distribution networks, sustainable building designs and others. As a timely review, this book can serve as an ideal reference f...

  2. Posttranslationally caused bioluminescence burst of the Escherichia coli luciferase reporter strain.

    Science.gov (United States)

    Ideguchi, Yamato; Oshikoshi, Yuta; Ryo, Masashi; Motoki, Shogo; Kuwano, Takashi; Tezuka, Takafumi; Aoki, Setsuyuki

    2016-01-01

    We continuously monitored bioluminescence from a wild-type reporter strain of Escherichia coli (lacp::luc+/WT), which carries the promoter of the lac operon (lacp) fused with the firefly luciferase gene (luc+). This strain showed a bioluminescence burst when shifted into the stationary growth phase. Bioluminescence profiles of other wild-type reporter strains (rpsPp::luc+ and argAp::luc+) and gene-deletion reporter strains (lacp::luc+/crp- and lacp::luc+/lacI-) indicate that transcriptional regulation is not responsible for generation of the burst. Consistently, changes in the luciferase protein levels did not recapitulate the profile of the burst. On the other hand, dissolved oxygen levels increased over the period across the burst, suggesting that the burst is, at least partially, caused by an increase in intracellular oxygen levels. We discuss limits of the firefly luciferase when used as a reporter for gene expression and its potential utility for monitoring metabolic changes in cells.

  3. Speech Emotion Recognition Using Fuzzy Logic Classifier

    Directory of Open Access Journals (Sweden)

    Daniar aghsanavard

    2016-01-01

    Full Text Available Over the last two decades, emotions, speech recognition and signal processing have been one of the most significant issues in the adoption of techniques to detect them. Each method has advantages and disadvantages. This paper tries to suggest fuzzy speech emotion recognition based on the classification of speech's signals in order to better recognition along with a higher speed. In this system, the use of fuzzy logic system with 5 layers, which is the combination of neural progressive network and algorithm optimization of firefly, first, speech samples have been given to input of fuzzy orbit and then, signals will be investigated and primary classified in a fuzzy framework. In this model, a pattern of signals will be created for each class of signals, which results in reduction of signal data dimension as well as easier speech recognition. The obtained experimental results show that our proposed method (categorized by firefly, improves recognition of utterances.

  4. Nature-inspired optimization algorithms

    CERN Document Server

    Yang, Xin-She

    2014-01-01

    Nature-Inspired Optimization Algorithms provides a systematic introduction to all major nature-inspired algorithms for optimization. The book's unified approach, balancing algorithm introduction, theoretical background and practical implementation, complements extensive literature with well-chosen case studies to illustrate how these algorithms work. Topics include particle swarm optimization, ant and bee algorithms, simulated annealing, cuckoo search, firefly algorithm, bat algorithm, flower algorithm, harmony search, algorithm analysis, constraint handling, hybrid methods, parameter tuning

  5. Bioluminescence assay for cell viability.

    Science.gov (United States)

    Lomakina, G Yu; Modestova, Yu A; Ugarova, N N

    2015-06-01

    Theoretical aspects of the adenosine triphosphate bioluminescence assay based on the use of the firefly luciferin-luciferase system are considered, as well as its application for assessing cell viability in microbiology, sanitation, medicine, and ecology. Various approaches for the analysis of individual or mixed cultures of microorganisms are presented, and capabilities of the method for investigation of biological processes in live cells including necrosis, apoptosis, as well as for investigation of the dynamics of metabolism are described.

  6. Bioluminescent imaging of vaccinia virus infection in immunocompetent and immunodeficient rats as a model for human smallpox

    OpenAIRE

    Qiang Liu; Changfa Fan; Shuya Zhou; Yanan Guo; Qin Zuo; Jian Ma; Susu Liu; Xi Wu; Zexu Peng; Tao Fan; Chaoshe Guo; Yuelei Shen; Weijin Huang; Baowen Li; Zhengming He

    2015-01-01

    Due to the increasing concern of using smallpox virus as biological weapons for terrorist attack, there is renewed interest in studying the pathogenesis of human smallpox and development of new therapies. Animal models are highly demanded for efficacy and safety examination of new vaccines and therapeutic drugs. Here, we demonstrated that both wild type and immunodeficient rats infected with an engineered vaccinia virus carrying Firefly luciferase reporter gene (rTV-Fluc) could recapitulate i...

  7. Plasmid DNA entry into postmitotic nuclei of primary rat myotubes.

    OpenAIRE

    Dowty, M E; Williams, P.; G. Zhang; Hagstrom, J E; Wolff, J A

    1995-01-01

    These studies were initiated to elucidate the mechanism of DNA nuclear transport in mammalian cells. Biotin- or gold-labeled plasmid and plasmid DNA expression vectors for Escherichia coli beta-galactosidase or firefly luciferase were microinjected into the cytoplasm of primary rat myotubes in culture. Plasmid DNA was expressed in up to 70% of the injected myotubes, which indicates that it entered intact, postmitotic nuclei. The nuclear transport of plasmid DNA occurred through the nuclear po...

  8. Cell-Penetrating Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate Cancer

    Science.gov (United States)

    2015-10-01

    observations with DHT -stimulated luciferase activity assays, enzalutamide had no effect on the constitutive induction of luciferase activity by the AR...to expess firefly luciferase under the control of a synthetic ARE. Similar studies were also performed with intact LNCaP cells stimulated with DHT ...enzalutamide. B. Demonstration that 3E10-AR441 can inhibit non-genomic, AR-dependent signaling. These studies used LNCaP cells stimulated with DHT , with a

  9. Assembly of Two Transgenes in an Artificial Chromatin Domain Gives Highly Coordinated Expression in Tobacco

    OpenAIRE

    2002-01-01

    The chromatin loop model predicts that genes within the same chromatin domain exhibit coordinated regulation. We here present the first direct experimental support for this model in plants. Two reporter genes, the E. coli beta-glucuronidase gene and the firefly luciferase gene, driven by different promoters, were placed between copies of the chicken lysozyme A element, a member of the matrix-associated region (MAR) group of chromatin boundary elements, and introduced in tobacco (Nicotiana tab...

  10. Role of IKKs and Transcription Factor NF-kB in Prostate Tumorigenesis

    Science.gov (United States)

    2006-05-01

    luciferase reporter – Firefly luciferase (FL) under a 5 kB promoter kindly provided by Dr WC Greene ( Gladstone Institute for Virology and Immunology...alpha. Acknowledgements We thank Dr WC Greene ( Gladstone Institute for Virology and Immunology, University of California, San Francisco, CA, USA) and Dr F...Muenchen HJ, Lin DL, Walsh MA, Keller ET, Pienta KJ. (2000). Clin Cancer Res 6: 1969 –1977. Murata T, Shimada M, Kadono H, Sakakibara S, Yoshino T, Masuda

  11. Integration of Environmental Sensors with BIM: case studies using Arduino, Dynamo, and the Revit API

    OpenAIRE

    Kensek, K. M.

    2014-01-01

    This paper investigates the feasibility of connecting environmental sensors such as light, humidity, or CO2 receptors to a building information model (BIM). A base case was created in Rhino; using Grasshopper and Firefly, a simple digital model responded to lighting-levels detected by a photoresistor on an Arduino board. The case study was duplicated using Revit Architecture, a popular BIM software, and Dynamo, a visual programming environment, in an innovative application. Another case study...

  12. Chemical production of excited states in biology: mechanism, regulation and function. Renewal proposal and tri-annual summary report, July 1, 1974--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, H H

    1977-01-01

    Progress is reported on studies of molecular mechanisms involved in bioluminescent reactions in fireflies, in purified calcium-activated photoproteins from marine microorganisms, and in marine dinoflagellates. The role of luciferase binding protein mechanisms in photon-stimulated bioluminescence is discussed. The use of chemiluminescence as an assay technique for nicotine in tobacco smoke and carcinogenic hydrocarbons in environmental samples is proposed and the requirements for such an assay system are reviewed.

  13. Competition between influenza A virus genome segments.

    Directory of Open Access Journals (Sweden)

    Ivy Widjaja

    Full Text Available Influenza A virus (IAV contains a segmented negative-strand RNA genome. How IAV balances the replication and transcription of its multiple genome segments is not understood. We developed a dual competition assay based on the co-transfection of firefly or Gaussia luciferase-encoding genome segments together with plasmids encoding IAV polymerase subunits and nucleoprotein. At limiting amounts of polymerase subunits, expression of the firefly luciferase segment was negatively affected by the presence of its Gaussia luciferase counterpart, indicative of competition between reporter genome segments. This competition could be relieved by increasing or decreasing the relative amounts of firefly or Gaussia reporter segment, respectively. The balance between the luciferase expression levels was also affected by the identity of the untranslated regions (UTRs as well as segment length. In general it appeared that genome segments displaying inherent higher expression levels were more efficient competitors of another segment. When natural genome segments were tested for their ability to suppress reporter gene expression, shorter genome segments generally reduced firefly luciferase expression to a larger extent, with the M and NS segments having the largest effect. The balance between different reporter segments was most dramatically affected by the introduction of UTR panhandle-stabilizing mutations. Furthermore, only reporter genome segments carrying these mutations were able to efficiently compete with the natural genome segments in infected cells. Our data indicate that IAV genome segments compete for available polymerases. Competition is affected by segment length, coding region, and UTRs. This competition is probably most apparent early during infection, when limiting amounts of polymerases are present, and may contribute to the regulation of segment-specific replication and transcription.

  14. Researchers Discover Plants Biological Clock

    Institute of Scientific and Technical Information of China (English)

    王全良

    1996-01-01

    Scientists who created glow-in-the-dark plants by shooting up seedlingswith firefly DNA have identified the first biological clock gene in plants. Discovery of the timepiece gene, which controls such biological rhythmsas daily leaf movements and proe openings, flower-blooming schedules andphotosynthesis cycles, could lead to a host of applications in ornamental horti-culture, agriculture and even human health. Many researchers believe that

  15. Prediction of Shanghai Index based on Additive Legendre Neural Network

    Directory of Open Access Journals (Sweden)

    Yang Bin

    2017-01-01

    Full Text Available In this paper, a novel Legendre neural network model is proposed, namely additive Legendre neural network (ALNN. A new hybrid evolutionary method besed on binary particle swarm optimization (BPSO algorithm and firefly algorithm is proposed to optimize the structure and parameters of ALNN model. Shanghai stock exchange composite index is used to evaluate the performance of ALNN. Results reveal that ALNN performs better than LNN model.

  16. Rozvoj hudební tvořivosti žáků na základě Karafiátových Broučků

    OpenAIRE

    ŠIMKOVÁ, Klára

    2013-01-01

    This thesis is devoted to musical creativity of children and its development. It is divided into two parts - theoretical and practical. Theoretical part deals with the definition of musical creativity of children, its place in school and the benefits of its development. The practical part is followed by musical project designed primarily for music lessons at the first schools. The project is connected with the storyline Fireflies of Jan Karafiát.

  17. Research on Glowworm Swarm Optimization with Ethnic Division

    Directory of Open Access Journals (Sweden)

    Huabei Nie

    2014-02-01

    Full Text Available Glowworm swarm optimization (GSO algorithm is a new intelligent optimization algorithm. Based on the problems of GSO, such as easy to fall into local optimum, slow convergence speed and low optimization precision, an improved GSO with group division is presented. Using shuffled frog leaping algorithm (SFLA, glowworms are divide into different ethnic groups, and local search and global information exchange method improves the GSO performance. The mechanism based on particle position update mechanism in PSO is proposed in order to improve glowworm diversity. By using chaos optimization technique, glowworm groups are initialized, and the algorithm can obtain high quality initial solutions group. Finally, with the classical test functions, the simulation results show that, the GSO with hybrid behavior has better convergence speed and precision. According to the different types of firefly and cold light color is not the same, the glowworm swarm is divided into two sub group, to complete the aspects of paired glowworm swarm population quantity change. Then the cloth Valley bird search algorithm, cloth Valley bird by Levi to fly to the best way to choose size, this kind of flying mode with the machine more strong, will this flight mode into two populations of fireflies swarm evolutionary algorithm. Finish the fireflies optimization path of improvement

  18. Flow injection analysis with bioluminescence-based fiber-optic biosensors

    Science.gov (United States)

    Blum, Loic J.; Gautier, Sabine; Coulet, Pierre R.

    1991-09-01

    Fiber optic biosensors based on the firefly and the bacterial bioluminescence reactions have been constructed and incorporated in a specially designed flow-cell for the sensitive determination of ATP and NADH, respectively. The bioluminescence enzymes were immobilized on preactivated polyamide membranes which were placed in close contact with the surface on one end of a glass-fiber bundle, the other end being connected to the photomultiplier tube of a luminometer. When using the continuous-flow device with the firefly luciferase or the bacterial system immobilized separately on different membranes, the detection limit for ATP and NADH were 0.25 and 2 pmol, respectively. The versatility of the fiber optic probe has been improved by co-immobilizing the bacterial bioluminescent system and the firefly luciferase on the same support enabling the use of a single sensor for the selective, specific, and alternate determination of these two analytes. Compatible reaction conditions preserving the activity of each co-immobilized enzyme without impairing its stability were found. The selection of the appropriate reaction medium was done using a four port valve. Alternate quantification of ATP and NADH could then be performed in the linear ranges 0.25 pmol - 3 nmol and 5 pmol - 1 nmol, respectively with a RSD of 4.0 - 4.5%.

  19. A luciferin analogue generating near-infrared bioluminescence achieves highly sensitive deep-tissue imaging.

    Science.gov (United States)

    Kuchimaru, Takahiro; Iwano, Satoshi; Kiyama, Masahiro; Mitsumata, Shun; Kadonosono, Tetsuya; Niwa, Haruki; Maki, Shojiro; Kizaka-Kondoh, Shinae

    2016-06-14

    In preclinical cancer research, bioluminescence imaging with firefly luciferase and D-luciferin has become a standard to monitor biological processes both in vitro and in vivo. However, the emission maximum (λmax) of bioluminescence produced by D-luciferin is 562 nm where light is not highly penetrable in biological tissues. This emphasizes a need for developing a red-shifted bioluminescence imaging system to improve detection sensitivity of targets in deep tissue. Here we characterize the bioluminescent properties of the newly synthesized luciferin analogue, AkaLumine-HCl. The bioluminescence produced by AkaLumine-HCl in reactions with native firefly luciferase is in the near-infrared wavelength ranges (λmax=677 nm), and yields significantly increased target-detection sensitivity from deep tissues with maximal signals attained at very low concentrations, as compared with D-luciferin and emerging synthetic luciferin CycLuc1. These characteristics offer a more sensitive and accurate method for non-invasive bioluminescence imaging with native firefly luciferase in various animal models.

  20. Use of near infrared fluorescence during robot-assisted laparoscopic partial nephrectomy.

    Science.gov (United States)

    Cornejo-Dávila, V; Nazmy, M; Kella, N; Palmeros-Rodríguez, M A; Morales-Montor, J G; Pacheco-Gahbler, C

    2016-04-01

    Partial nephrectomy is the treatment of choice for T1a tumours. The open approach is still the standard method. Robot-assisted laparoscopic surgery offers advantages that are applicable to partial nephrectomy, such as the use of the Firefly® system with near-infrared fluorescence. To demonstrate the implementation of fluorescence in nephron-sparing surgery. This case concerned a 37-year-old female smoker, with obesity. The patient had a right kidney tumour measuring 31 mm, which was found using tomography. She therefore underwent robot-assisted laparoscopic partial nephrectomy, with a warm ischaemia time of 22 minutes and the use of fluorescence with the Firefly® system to guide the resection. There were no complications. The tumour was a pT1aN0M0 renal cell carcinoma, with negative margins. Robot-assisted renal laparoscopic surgery is employed for nephron-sparing surgery, with good oncological and functional results. The combination of the Firefly® technology and intraoperative ultrasound can more accurately delimit the extent of the lesion, increase the negative margins and decrease the ischaemia time. Near-infrared fluorescence in robot-assisted partial nephrectomy is useful for guiding the tumour resection and can potentially improve the oncological and functional results. Copyright © 2015 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Next Generation Search Interfaces

    Science.gov (United States)

    Roby, W.; Wu, X.; Ly, L.; Goldina, T.

    2015-09-01

    Astronomers are constantly looking for easier ways to access multiple data sets. While much effort is spent on VO, little thought is given to the types of User Interfaces we need to effectively search this sort of data. For instance, an astronomer might need to search Spitzer, WISE, and 2MASS catalogs and images then see the results presented together in one UI. Moving seamlessly between data sets is key to presenting integrated results. Results need to be viewed using first class, web based, integrated FITS viewers, XY Plots, and advanced table display tools. These components should be able to handle very large datasets. To make a powerful Web based UI that can manage and present multiple searches to the user requires taking advantage of many HTML5 features. AJAX is used to start searches and present results. Push notifications (Server Sent Events) monitor background jobs. Canvas is required for advanced result displays. Lesser known CSS3 technologies makes it all flow seamlessly together. At IPAC, we have been developing our Firefly toolkit for several years. We are now using it to solve this multiple data set, multiple queries, and integrated presentation problem to create a powerful research experience. Firefly was created in IRSA, the NASA/IPAC Infrared Science Archive (http://irsa.ipac.caltech.edu). Firefly is the core for applications serving many project archives, including Spitzer, Planck, WISE, PTF, LSST and others. It is also used in IRSA's new Finder Chart and catalog and image displays.

  2. Cancer specificity of promoters of the genes involved in cell proliferation control.

    Science.gov (United States)

    Kashkin, K N; Chernov, I P; Stukacheva, E A; Kopantzev, E P; Monastyrskaya, G S; Uspenskaya, N Ya; Sverdlov, E D

    2013-07-01

    Core promoters with adjacent regions of the human genes CDC6, POLD1, CKS1B, MCM2, and PLK1 were cloned into a pGL3 vector in front of the Photinus pyrails gene Luc in order to study the tumor specificity of the promoters. The cloned promoters were compared in their ability to direct luciferase expression in different human cancer cells and in normal fibroblasts. The cancer-specific promoter BIRC5 and non-specific CMV immediately early gene promoter were used for comparison. All cloned promoters were shown to be substantially more active in cancer cells than in fibroblasts, while the PLK1 promoter was the most cancer-specific and promising one. The specificity of the promoters to cancer cells descended in the series PLK1, CKS1B, POLD1, MCM2, and CDC6. The bidirectional activity of the cloned CKS1B promoter was demonstrated. It apparently directs the expression of the SHC1 gene, which is located in a "head-to-head" position to the CKS1B gene in the human genome. This feature should be taken into account in future use of the CKS1B promoter. The cloned promoters may be used in artificial genetic constructions for cancer gene therapy.

  3. Structural evolution of luciferase activity in Zophobas mealworm AMP/CoA-ligase (protoluciferase) through site-directed mutagenesis of the luciferin binding site.

    Science.gov (United States)

    Prado, R A; Barbosa, J A; Ohmiya, Y; Viviani, V R

    2011-07-01

    The structural origin and evolution of bioluminescent activity of beetle luciferases from AMP/CoA ligases remains a mystery. Previously we cloned the luciferase-like enzyme from Zophobas morio mealworm, a reasonable protoluciferase model that could shine light on this mystery. Kinetic characterization and studies with D- and L-luciferin and their adenylates showed that stereoselectivity constitutes a critical feature for the origin of luciferase activity in AMP/CoA ligases. Comparison of the primary structures and modeling studies of this protoluciferase and the three main families of beetle luciferases showed that the carboxylic acid substrate binding site of this enzyme is smaller and more hydrophobic than the luciferin binding site of beetle luciferases, showing several substitutions of otherwise conserved residues. Thus, here we performed a site-directed mutagenesis survey of the carboxylic binding site motifs of the protoluciferase by replacing their residues by the respective conserved ones found in beetle luciferases in order to identify the structural determinants of luciferase/oxygenase activity. Although most of the substitutions had negative impact on the luminescence activity of the protoluciferase, only the substitution I327T improved the luminescence activity, resulting in a broad and 15 nm blue-shifted luminescence spectrum. Such substitution indicates the importance of the loop motif 322YGMSEI327 (341YGLTETT347 in Photinus pyralis luciferase) for luciferase activity, and indicates a possible route for the evolution of bioluminescence function of beetle luciferases.

  4. Spectroscopic and functional characterization of Lampyris turkestanicus Iuciferase: a comparative study

    Institute of Scientific and Technical Information of China (English)

    Mojtaba Mortazavi; Saman Hosseinkhani; Khosro Khajeh; Bijan Ranjbar; A.Rahman Emamzadeh

    2008-01-01

    Functional expression and spectroscopic analysis of luciferases from Lampyris turkestanicus and Photinus pyralis were carried out. cDNA encoding L. turkestanicus luciferase was isolated by reverse transcription-polymerase chain reaction, cloned, and functionally expressed in Escherichia coil. The luciferases were purified to homogeneity using Ni-nitrilotriacetic acid Sepharose, and kinetic properties of luciferase from L. turkestanicus were compared with that from P.pyralis. Amino acid differences in its primary structures in relation to P.pyralis luciferase brought about changes in the kinetic properties of the enzyme as evidenced by substantial lowering of Km for ATP, increased light decay time, and decreased thermostability. Luciferase from L.turkestanicus was used to carry out Michaelis-Menten kinetics with a Km of 95.5 μM for A TP and 20 μM for inciferin.Maximum activity was recorded at pH 8.5, so it might be a suitable reporter for microbial screening at alkaline pH.Tryptophan fluorescence for P.pyralis luciferase was higher than L. turkestanicus luciferase. Substitution of some residues in L. turkestanicus hiciferase appears to change the kinetic properties by inducing a substantial tertiary structural change, without a large effect on secondary structural elements, as revealed by intrinsic and extrinsic fluorescence, Fourier transform infrared spectroscopy, and near-ultraviolet circular dichroism spectra.

  5. Dual-color bioluminescent bioreporter for forensic analysis: evidence of androgenic and anti-androgenic activity of illicit drugs.

    Science.gov (United States)

    Cevenini, Luca; Michelini, Elisa; D'Elia, Marcello; Guardigli, Massimo; Roda, Aldo

    2013-01-01

    Bioassays represent promising complementary techniques to conventional analytical approaches used in doping analysis to detect illicit drugs like anabolic-androgenic steroids (AAS). The fact that all AAS share a common mechanism of action via the human androgen receptor (hAR) enables the use of bioassays, relying on the activation of hAR as antidoping screening tools. Previously, we developed a dual-color bioreporter based on yeast cells engineered to express hAR and androgen response elements driving the expression of the bioluminescent (BL) reporter protein Photinus pyralis luciferase. A second reporter protein, the red-emitting luciferase PpyRE8, was introduced in the bioreporter as internal viability control. Here, we report the first forensic application of a straightforward, accurate, and cost-effective bioassay, relying on spectral resolution of the two BL signals, in 96-microwell format. The bioreporter responds to dihydrotestosterone as reference androgen in a concentration-dependent manner from 0.08 to 1,000 nM with intra- and inter-assay variation coefficients of 11.4 % and 13.1 %, respectively. We also demonstrated the suitability of this dual-color bioreporter to assess (anti)-androgenic activity of pure AAS, mixtures of AAS, and other illicit drugs provided by the Scientific Police. Significant anti-androgenic activity was observed in samples labeled as marijuana and hashish, containing Δ(9)-tetrahydrocannabinol as major constituent.

  6. Probing Bioluminescence Resonance Energy Transfer in Quantum Rod-Luciferase Nanoconjugates.

    Science.gov (United States)

    Alam, Rabeka; Karam, Liliana M; Doane, Tennyson L; Coopersmith, Kaitlin; Fontaine, Danielle M; Branchini, Bruce R; Maye, Mathew M

    2016-02-23

    We describe the necessary design criteria to create highly efficient energy transfer conjugates containing luciferase enzymes derived from Photinus pyralis (Ppy) and semiconductor quantum rods (QRs) with rod-in-rod (r/r) microstructure. By fine-tuning the synthetic conditions, CdSe/CdS r/r-QRs were prepared with two different emission colors and three different aspect ratios (l/w) each. These were hybridized with blue, green, and red emitting Ppy, leading to a number of new BRET nanoconjugates. Measurements of the emission BRET ratio (BR) indicate that the resulting energy transfer is highly dependent on QR energy accepting properties, which include absorption, quantum yield, and optical anisotropy, as well as its morphological and topological properties, such as aspect ratio and defect concentration. The highest BR was found using r/r-QRs with lower l/w that were conjugated with red Ppy, which may be activating one of the anisotropic CdSe core energy levels. The role QR surface defects play on Ppy binding, and energy transfer was studied by growth of gold nanoparticles at the defects, which indicated that each QR set has different sites. The Ppy binding at those sites is suggested by the observed BRET red-shift as a function of Ppy-to-QR loading (L), where the lowest L results in highest efficiency and furthest shift.

  7. Real time imaging of live cell ATP leaking or release events by chemiluminescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yun [Iowa State Univ., Ames, IA (United States)

    2008-12-18

    The purpose of this research was to expand the chemiluminescence microscopy applications in live bacterial/mammalian cell imaging and to improve the detection sensitivity for ATP leaking or release events. We first demonstrated that chemiluminescence (CL) imaging can be used to interrogate single bacterial cells. While using a luminometer allows detecting ATP from cell lysate extracted from at least 10 bacterial cells, all previous cell CL detection never reached this sensitivity of single bacteria level. We approached this goal with a different strategy from before: instead of breaking bacterial cell membrane and trying to capture the transiently diluted ATP with the firefly luciferase CL assay, we introduced the firefly luciferase enzyme into bacteria using the modern genetic techniques and placed the CL reaction substrate D-luciferin outside the cells. By damaging the cell membrane with various antibacterial drugs including antibiotics such as Penicillins and bacteriophages, the D-luciferin molecules diffused inside the cell and initiated the reaction that produces CL light. As firefly luciferases are large protein molecules which are retained within the cells before the total rupture and intracellular ATP concentration is high at the millmolar level, the CL reaction of firefly luciferase, ATP and D-luciferin can be kept for a relatively long time within the cells acting as a reaction container to generate enough photons for detection by the extremely sensitive intensified charge coupled device (ICCD) camera. The result was inspiring as various single bacterium lysis and leakage events were monitored with 10-s temporal resolution movies. We also found a new way of enhancing diffusion D-luciferin into cells by dehydrating the bacteria. Then we started with this novel single bacterial CL imaging technique, and applied it for quantifying gene expression levels from individual bacterial cells. Previous published result in single cell gene expression quantification

  8. ATP生物发光测定试剂研究进展%Reserach progress on ATP bioluminescence reagent

    Institute of Scientific and Technical Information of China (English)

    吴慧清; 李程思; 吴清平; 张菊梅

    2012-01-01

    Firefly luciferase is the key component of ATP bioluminescence reagent, gained from firefly lantern throuh extraction and purification or preparation through genetic engineering, the performance of ATP bioluminescence reagent was decided by the vitality and the purity of firefly luciferase.Up to now, many present advanced technology were applied on preparation the reagent such as genetic engineering, ATP amplification device, stabilization technology of luciferase protein and luminescence, and so on.Now research focus on improving detection sensitivity and luminescence performance of the ATP bioluminescence reagents, further raising the adaptability of ATP bioluminescence reagents.%萤火虫荧光素酶是ATP生物发光试剂的关键组成部分,可通过萤火虫尾提取纯化或基因工程技术制备,酶的活力和纯度决定了ATP生物发光试剂的性能.迄今许多先进技术在ATP生物发光试剂的制备中均有应用,包括酶基因工程改造技术、ATP循环的酶法放大技术、荧光素酶蛋白的活力及发光稳定技术,特异的细胞ATP提取技术等.ATP生物发光试剂的研究焦点主要集中在提高发光试剂的检测灵敏度和性能、增加产品的适应性等方面.

  9. Measurements of serum glucose using the luciferin/Luciferase system and a liquid scintillation spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Idahl, L.A.; Sandstroem, P.E.; Sehlin, J.

    1986-05-15

    A single-step assay for serum glucose measurements is described. The assay is based on the phosphorylation of D-glucose by glucokinase and the measurement of ATP consumption by firefly luciferase. The luminescence is recorded in an ordinary liquid scintillation spectrometer. The use of stable reagents and a stable final signal (light emission) makes it possible to analyze a large number of samples in each assay run. The assay is of particular value when repeated serum glucose determinations are performed on samples from small laboratory animals.

  10. Effects of continuous chlorination on entrained estuarine plankton

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, S.J.; Foulk, H.R.

    1980-01-01

    Technical report: The effects of continuous chlorination in running sea water on entrained plankton were examined. The concentration of ATP was used as an indicator of biomass because: it is present in all living cells; the concentration is proportional to the living biomass; and dead cells lose ATP rapidly. Effects were measured by bioluminescence; luciferin-luciferase reagents from firefly lanterns were used to analyze ATP concentration. Results indicate that ATP measurement is an accurate, effective means of evaluating damage done to planktonic organisms by continuous chlorination. Further studies of the effects of low-concentration, continuous chlorination are recommended. (13 references, 1 table)

  11. Adenosine triphosphate (ATP) as a possible indicator of extraterrestrial biology

    Science.gov (United States)

    Chappelle, E. W.; Picciolo, G. L.

    1974-01-01

    The ubiquity of adenosine triphosphate (ATP) in terrestrial organisms provides the basis for proposing the assay of this vital metabolic intermediate for detecting extraterrestrial biological activity. If an organic carbon chemistry is present on the planets, the occurrence of ATP is possible either from biosynthetic or purely chemical reactions. However, ATP's relative complexity minimizes the probability of abiogenic synthesis. A sensitive technique for the quantitative detection of ATP was developed using the firefly bioluminescent reaction. The procedure was used successfully for the determination of the ATP content of soil and bacteria. This technique is also being investigated from the standpoint of its application in clinical medicine.

  12. A question of scale

    CERN Document Server

    Vicsek, Tamás

    2010-01-01

    If you search for 'collective behaviour' with your web browser most of the texts popping up will be about group activities of humans, including riots, fashion and mass panic. Nevertheless, collective behaviour is also considered to be an important aspect of observed phenomena in atoms and molecules, for example, during spontaneous magnetization. In your web search, you might also find articles on collectively migrating bacteria, insects or birds; or phenomena where groups of organisms or non- living objects synchronize their signals or motion (think of fireflies flashing in unison or people clapping in phase during rhythmic applause).

  13. Optimized extreme learning machine for urban land cover classification using hyperspectral imagery

    Science.gov (United States)

    Su, Hongjun; Tian, Shufang; Cai, Yue; Sheng, Yehua; Chen, Chen; Najafian, Maryam

    2016-11-01

    This work presents a new urban land cover classification framework using the firefly algorithm (FA) optimized extreme learning machine (ELM). FA is adopted to optimize the regularization coefficient C and Gaussian kernel s for kernel ELM. Additionally, effectiveness of spectral features derived from an FA-based band selection algorithm is studied for the proposed classification task. Three sets of hyperspectral databases were recorded using different sensors, namely HYDICE, HyMap, and AVIRIS. Our study shows that the proposed method outperforms traditional classification algorithms such as SVM and reduces computational cost significantly.

  14. Bioluminometric assay of ATP in mouse brain: Determinant factors for enhanced test sensitivity

    Indian Academy of Sciences (India)

    Haseeb Ahmad Khan

    2003-06-01

    Firefly luciferase bioluminescence (FLB) is a highly sensitive and specific method for the analysis of adenosine-5-triphosphate (ATP) in biological samples. Earlier attempts to modify the FLB test for enhanced sensitivity have been typically based on in vitro cell systems. This study reports an optimized FLB procedure for the analysis of ATP in small tissue samples. The results showed that the sensitivity of the FLB test can be enhanced several fold by using ultraturax homogenizer, perchloric acid extraction, neutralization of acid extract and its optimal dilution, before performing the assay reaction.

  15. Luminescence as a Continuous Real-Time Reporter of Promoter Activity in Yeast Undergoing Respiratory Oscillations or Cell Division Rhythms

    Science.gov (United States)

    Robertson, J. Brian; Johnson, Carl Hirschie

    2012-01-01

    This chapter describes a method for generating yeast respiratory oscillations in continuous culture and monitoring rhythmic promoter activity of the culture by automated real-time recording of luminescence. These techniques chiefly require the use of a strain of Saccharomyces cerevisiae that has been genetically modified to express firefly luciferase under the control of a promoter of interest and a continuous culture bioreactor that incorporates a photomultiplier apparatus for detecting light emission. Additionally, this chapter describes a method for observing rhythmic (cell cycle-related) promoter activity in small batch cultures of yeast through luminescence monitoring. PMID:21468985

  16. Reporter Proteins in Whole-Cell Optical Bioreporter Detection Systems, Biosensor Integrations, and Biosensing Applications

    Science.gov (United States)

    Close, Dan M.; Ripp, Steven; Sayler, Gary S.

    2009-01-01

    Whole-cell, genetically modified bioreporters are designed to emit detectable signals in response to a target analyte or related group of analytes. When integrated with a transducer capable of measuring those signals, a biosensor results that acts as a self-contained analytical system useful in basic and applied environmental, medical, pharmacological, and agricultural sciences. Historically, these devices have focused on signaling proteins such as green fluorescent protein, aequorin, firefly luciferase, and/or bacterial luciferase. The biochemistry and genetic development of these sensor systems as well as the advantages, challenges, and common applications of each one will be discussed. PMID:22291559

  17. Reporter Proteins in Whole-Cell Optical Bioreporter Detection Systems, Biosensor Integrations, and Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Gary S. Sayler

    2009-11-01

    Full Text Available Whole-cell, genetically modified bioreporters are designed to emit detectable signals in response to a target analyte or related group of analytes. When integrated with a transducer capable of measuring those signals, a biosensor results that acts as a self-contained analytical system useful in basic and applied environmental, medical, pharmacological, and agricultural sciences. Historically, these devices have focused on signaling proteins such as green fluorescent protein, aequorin, firefly luciferase, and/or bacterial luciferase. The biochemistry and genetic development of these sensor systems as well as the advantages, challenges, and common applications of each one will be discussed.

  18. The world made by Noble prize : chemistry volume II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-06-15

    This book has two parts of items related chemistry. The contents of the first part are Preface, Alfred Bemhard Nobel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne, and firefly. The contents of the second part are PET-MRI, Color photo, Holography, Art diamond, an incandescent lamp and Neon Sign, Imitation works, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Propane gas, Water Car, Estate agency Mars, and reference.

  19. The world made by Noble prize : chemistry volume I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-06-15

    This book contains two parts about items by chemistry. The first part introduces Alfred Bernhard Nodel, Pioneers without Nobel Prize, Garbage Bag, Non-sticky Frying Pan, Nylon Stockings, Plastic Electricity, Synthetic Dyestuff, Gin and Tonic, Soccer Ball, Fertilizer, DDT, Dentifrice, Kimchi, Makgeolli, Ice cream, Anodyne and Firefly. The second part lists PET-MRI, Color photo, Holography, Art diamond Incandescent lamp and Neon Sign, Imitation work, Alchemy, Nuclear Power plant, Synthetic Oil and Sugar, Freon gas, Water Car, Estate agency Mars, and winners of Nobel prize in physics.

  20. Fusion genetic analysis of jasmonate-signalling mutants in Arabidopsis

    DEFF Research Database (Denmark)

    Jensen, Anders Bøgh; Raventos, D.; Mundy, John Williams

    2002-01-01

    Jasmonates induce plant-defence responses and act to regulate defence-related genes including positive feedback of the lipoxygenase 2 (LOX2) gene involved in jasmonate synthesis. To identify jasmonate-signalling mutants, we used a fusion genetic strategy in which the firefly luciferase (FLUC...... as two recessive mutants, designated joe1 and 2, that overexpress the reporter. Genetic analysis indicated that reporter overexpression in the joe mutants requires COI. joe1 responded to MeJA with increased anthocyanin accumulation, while joe2 responded with decreased root growth inhibition. In addition...

  1. Characterization of Steroid Receptor RNA Activator Protein Function in Modulating the Estrogen Signaling Pathway

    Science.gov (United States)

    2008-03-01

    upstream of the firefly luciferase cDNA) and 0.1 lg of renilla luciferase reporter vector (Promega, Madison, WI) using the lipo - fectamine reagent...regulatory factor 1 JUN + V-jun sarcoma virus 17 oncogene homologue JUN B + JUNB proto-oncogene LDB1 ++ LIM domain binding 1 LHX2 ++ LIM homeobox 2...0.021 ESR2 Estrogen receptor 2 (ER beta) 1.73 331 0.029 STC2 Stanniocalcin 2 1.20 230 0.009 JUN V-jun sarcoma virus 17 oncogene homolog (avian

  2. New Breed of Mice May Improve Accuracy for Preclinical Testing of Cancer Drugs | Poster

    Science.gov (United States)

    A new breed of lab animals, dubbed “glowing head mice,” may do a better job than conventional mice in predicting the success of experimental cancer drugs—while also helping to meet an urgent need for more realistic preclinical animal models. The mice were developed to tolerate often-used light-emitting molecules, such as luciferase from fireflies and green fluorescent protein (GFP) from jellyfish. These “optical reporters” are useful for monitoring the effect of experimental therapies in live animals over time because they emit an immediate and easily detected light signal showing whether a tumor inside the animal’s body is shrinking as desired.

  3. Chemiluminescence of Organic Compounds.

    Science.gov (United States)

    1981-04-07

    Brandl , 1979 ; Kamiva, 1980) and bioluminescence (M-(’ipr;i, 1976; Henry and Michelson, I078 ; Hlastins,,g and Wilson, 1976 ; Cormier et al., 1975...mechanism for the firefly by pur- porting to show that Co., formed L., not labeled. However, the recognition of the danger of compLete isotopic...R. F and Kearns, 1). K. (1966-T.- en. hvs; *4 , 145. Brandl , II. (1979). Natuirwiss. )(thmOM. 29, 0 5. C(alvert, J. C. and Pitts, .. N. (1966

  4. Theoretical mechanics: Crowd synchrony on the Millennium Bridge

    Science.gov (United States)

    Strogatz, Steven H.; Abrams, Daniel M.; McRobie, Allan; Eckhardt, Bruno; Ott, Edward

    2005-11-01

    Soon after the crowd streamed on to London's Millennium Bridge on the day it opened, the bridge started to sway from side to side: many pedestrians fell spontaneously into step with the bridge's vibrations, inadvertently amplifying them. Here we model this unexpected and now notorious phenomenon - which was not due to the bridge's innovative design as was first thought - by adapting ideas originally developed to describe the collective synchronization of biological oscillators such as neurons and fireflies. Our approach should help engineers to estimate the damping needed to stabilize other exceptionally crowded footbridges against synchronous lateral excitation by pedestrians.

  5. A New Metaheuristic Bat-Inspired Algorithm

    CERN Document Server

    Yang, Xin-She

    2010-01-01

    Metaheuristic algorithms such as particle swarm optimization, firefly algorithm and harmony search are now becoming powerful methods for solving many tough optimization problems. In this paper, we propose a new metaheuristic method, the Bat Algorithm, based on the echolocation behaviour of bats. We also intend to combine the advantages of existing algorithms into the new bat algorithm. After a detailed formulation and explanation of its implementation, we will then compare the proposed algorithm with other existing algorithms, including genetic algorithms and particle swarm optimization. Simulations show that the proposed algorithm seems much superior to other algorithms, and further studies are also discussed.

  6. Fast vector quantization using a Bat algorithm for image compression

    Directory of Open Access Journals (Sweden)

    Chiranjeevi Karri

    2016-06-01

    Full Text Available Linde–Buzo–Gray (LBG, a traditional method of vector quantization (VQ generates a local optimal codebook which results in lower PSNR value. The performance of vector quantization (VQ depends on the appropriate codebook, so researchers proposed optimization techniques for global codebook generation. Particle swarm optimization (PSO and Firefly algorithm (FA generate an efficient codebook, but undergoes instability in convergence when particle velocity is high and non-availability of brighter fireflies in the search space respectively. In this paper, we propose a new algorithm called BA-LBG which uses Bat Algorithm on initial solution of LBG. It produces an efficient codebook with less computational time and results very good PSNR due to its automatic zooming feature using adjustable pulse emission rate and loudness of bats. From the results, we observed that BA-LBG has high PSNR compared to LBG, PSO-LBG, Quantum PSO-LBG, HBMO-LBG and FA-LBG, and its average convergence speed is 1.841 times faster than HBMO-LBG and FA-LBG but no significance difference with PSO.

  7. The influence of hypoxia on bioluminescence in luciferase-transfected gliosarcoma tumor cells in vitro.

    Science.gov (United States)

    Moriyama, Eduardo H; Niedre, Mark J; Jarvi, Mark T; Mocanu, Joseph D; Moriyama, Yumi; Subarsky, Patrick; Li, Buhong; Lilge, Lothar D; Wilson, Brian C

    2008-06-01

    Firefly luciferase catalyzes the emission of light from luciferin in the presence of oxygen and adenosine triphosphate. This bioluminescence is commonly employed in imaging mode to monitor tumor growth and treatment responses in vivo. A potential concern is that, since solid tumors are often hypoxic, either constitutively and/or as a result of treatment, the oxygen available for the bioluminescence reaction could be reduced to limiting levels, leading to underestimation of the actual number of luciferase-labeled cells during in vivo experiments. We present studies of the oxygen dependence of bioluminescence in vitro in rat 9 L gliosarcoma cells tagged with the firefly luciferase gene (9L(luc)). We demonstrate that the bioluminescence signal decreases at pO(2) ATP due to the reduction of mitochondrial membrane potential. Hence, the data suggest that the decrease of intracellular ATP level in vitro is the limiting factor for bioluminescence reaction and so is responsible for the reduction of bioluminescence signal in 9L(luc) cells in acute hypoxia, rather than luciferase expression or oxygen itself.

  8. Bridging the phenotypic gap: Real-time assessment of mitochondrial function and metabolism of the nematode Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Flett Aileen

    2008-04-01

    Full Text Available Abstract Background The ATP levels of an organism are an important physiological parameter that is affected by genetic make up, ageing, stress and disease. Results We have generated luminescent C. elegans through ubiquitous, constitutive expression of firefly luciferase, widely used for in vitro ATP determination. We hypothesise that whole animal luminescence reflects its intracellular ATP levels in vivo. To test this, we characterised the bioluminescence response of C. elegans during sublethal exposure to, and recovery from azide, a treatment that inhibits mitochondrial respiration reversibly, and causes ATP depletion. Consistent with our expectations, in vivo luminescence decreased with increasing sublethal azide levels, and recovered fully when worms were removed from azide. Firefly luciferase expression levels, stability and activity did not influence the final luminescence. Bioluminescence also reflected the lowered activity of the electron transport chain achieved with RNA interference (RNAi of genes encoding respiratory chain components. Conclusion Results indicated that C. elegans luminescence reports on ATP levels in real-time. For the first time, we are able to directly assess the metabolism of a whole, living, multicellular organism by determination of the relative ATP levels. This will enable genetic analysis based on a readily quantifiable metabolic phenotype and will provide novel insights into mechanisms of fitness and disease that are likely to be of relevance for other organisms, as well as the worm.

  9. Meta-Heuristics Algorithms based on the Grouping of Animals by Social Behavior for the Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Jorge A. Ruiz-Vanoye

    2012-07-01

    Full Text Available In this paper, we show a survey of meta-heuristics algorithms based on grouping of animals by social behavior for the Traveling Salesman Problem, and propose a new classification of meta-heuristics algorithms (not based on swarm intelligence theory based on grouping of animals: swarm algorithms, schools algorithms, flocks algorithms and herds algorithms: a The swarm algorithms (inspired by the insect swarms and zooplankton swarms: Ant Colony Optimization algorithm – ACO (inspired by the research on the behavior of ant colonies, Firefly Algorithm (based on fireflies, Marriage in Honey Bees Optimization Algorithm - MBO algorithm (inspired by the Honey Bee, Wasp Swarm Algorithm (inspired on the Parasitic wasps, Termite Algorithm (inspired by the termites, Mosquito swarms Algorithm – MSA (inspired by mosquito swarms, zooplankton swarms Algorithm - ZSA (inspired by the Zooplankton and Bumblebees Swarms Algorithm – BSA (inspired by Bumblebees. b The school algorithms (inspired by the fish schools: The Particle Swarm Optimization algorithm – PSO (inspired by social behavior and movement dynamics of fish or schooling. c The flock algorithms (inspired by the bird flocks: the flocking algorithm, and the Particle Swarm Optimization algorithm (inspired on the dynamics of the birds, d The herd and pack Algorithms (inspired by the mammal herds and packs: bat algorithm (inspired by bat, wolf pack search algorithm - WPS (inspired by wolfs, Rats herds algorithm - RATHA (inspired by Rats, Dolphins Herds Algorithm - DHA (inspired by Dolphins and the feral-dogs herd algorithm - FDHA (inspired by feral-dogs herd.

  10. Effect of heavy atoms in bioluminescent reactions.

    Science.gov (United States)

    Kirillova, Tamara N; Kudryasheva, Nadezhda S

    2007-03-01

    Bioluminescent reactions of luminous organisms are excellent models for studying the effects of heavy atoms on enzymatic processes. The effects of potassium halides with halide anions of different atomic weight were compared in bioluminescent reactions of the firefly (Luciola mingrelica), a marine coelenterate (Obelia longissima), and a marine bacterium (Photobacterium leiognathi). Two mechanisms of the effects of the halides were examined-the physicochemical effect of the external heavy atom, based on spin-orbit interactions in electron-excited structures, and the biochemical effect, i.e. interactions with the enzymes resulting in changes of enzymatic activity. The physicochemical effect was evaluated by using photoexcitation of model fluorescent compounds (flavin mononucleotide, firefly luciferin, and coelenteramide) of similar structure to the bioluminescence emitters. The bioluminescent and photoluminescent inhibition coefficients were calculated and compared for the luminous organisms to evaluate the relative contributions of the two mechanisms. The biochemical mechanism was found to be dominant. Hence, the bioluminescent reactions can be used as assays to monitor enzyme inhibition, in metabolic processes, by Br or I-containing compounds.

  11. Geolocating thermal binoculars based on a software defined camera core incorporating HOT MCT grown by MOVPE

    Science.gov (United States)

    Pillans, Luke; Harmer, Jack; Edwards, Tim; Richardson, Lee

    2016-05-01

    Geolocation is the process of calculating a target position based on bearing and range relative to the known location of the observer. A high performance thermal imager with integrated geolocation functions is a powerful long range targeting device. Firefly is a software defined camera core incorporating a system-on-a-chip processor running the AndroidTM operating system. The processor has a range of industry standard serial interfaces which were used to interface to peripheral devices including a laser rangefinder and a digital magnetic compass. The core has built in Global Positioning System (GPS) which provides the third variable required for geolocation. The graphical capability of Firefly allowed flexibility in the design of the man-machine interface (MMI), so the finished system can give access to extensive functionality without appearing cumbersome or over-complicated to the user. This paper covers both the hardware and software design of the system, including how the camera core influenced the selection of peripheral hardware, and the MMI design process which incorporated user feedback at various stages.

  12. Biologically Inspired Intercellular Slot Synchronization

    Directory of Open Access Journals (Sweden)

    Alexander Tyrrell

    2009-01-01

    Full Text Available The present article develops a decentralized interbase station slot synchronization algorithm suitable for cellular mobile communication systems. The proposed cellular firefly synchronization (CelFSync algorithm is derived from the theory of pulse-coupled oscillators, common to describe synchronization phenomena in biological systems, such as the spontaneous synchronization of fireflies. In order to maintain synchronization among base stations (BSs, even when there is no direct link between adjacent BSs, some selected user terminals (UTs participate in the network synchronization process. Synchronization emerges by exchanging two distinct synchronization words, one transmitted by BSs and the other by active UTs, without any a priori assumption on the initial timing misalignments of BSs and UTs. In large-scale networks with inter-BS site distances up to a few kilometers, propagation delays severely affect the attainable timing accuracy of CelFSync. We show that by an appropriate combination of CelFSync with the timing advance procedure, which aligns uplink transmission of UTs to arrive simultaneously at the BS, a timing accuracy within a fraction of the inter-BS propagation delay is retained.

  13. Highly Potent Cell-Permeable and Impermeable NanoLuc Luciferase Inhibitors.

    Science.gov (United States)

    Walker, Joel R; Hall, Mary P; Zimprich, Chad A; Robers, Matthew B; Duellman, Sarah J; Machleidt, Thomas; Rodriguez, Jacquelynn; Zhou, Wenhui

    2017-04-21

    Novel engineered NanoLuc (Nluc) luciferase being smaller, brighter, and superior to traditional firefly (Fluc) or Renilla (Rluc) provides a great opportunity for the development of numerous biological, biomedical, clinical, and food and environmental safety applications. This new platform created an urgent need for Nluc inhibitors that could allow selective bioluminescent suppression and multiplexing compatibility with existing luminescence or fluorescence assays. Starting from thienopyrrole carboxylate 1, a hit from a 42 000 PubChem compound library with a low micromolar IC50 against Nluc, we derivatized four different structural fragments to discover a family of potent, single digit nanomolar, cell permeable inhibitors. Further elaboration revealed a channel that allowed access to the external Nluc surface, resulting in a series of highly potent cell impermeable Nluc inhibitors with negatively charged groups likely extending to the protein surface. The permeability was evaluated by comparing EC50 shifts calculated from both live and lysed cells expressing Nluc cytosolically. Luminescence imaging further confirmed that cell permeable compounds inhibit both intracellular and extracellular Nluc, whereas less permeable compounds differentially inhibit extracellular Nluc and Nluc on the cell surface. The compounds displayed little to no toxicity to cells and high luciferase specificity, showing no activity against firefly luciferase or even the closely related NanoBit system. Looking forward, the structural motifs used to gain access to the Nluc surface can also be appended with other functional groups, and therefore interesting opportunities for developing assays based on relief-of-inhibition can be envisioned.

  14. Intelligent Technique for Signal Processing to Identify the Brain Disorder for Epilepsy Captures Using Fuzzy Systems

    Directory of Open Access Journals (Sweden)

    Gurumurthy Sasikumar

    2016-01-01

    Full Text Available The new direction of understand the signal that is created from the brain organization is one of the main chores in the brain signal processing. Amid all the neurological disorders the human brain epilepsy is measured as one of the extreme prevalent and then programmed artificial intelligence detection technique is an essential due to the crooked and unpredictable nature of happening of epileptic seizures. We proposed an Improved Fuzzy firefly algorithm, which would enhance the classification of the brain signal efficiently with minimum iteration. An important bunching technique created on fuzzy logic is the Fuzzy C means. Together in the feature domain with the spatial domain the features gained after multichannel EEG signals remained combined by means of fuzzy algorithms. And for better precision segmentation process the firefly algorithm is applied to optimize the Fuzzy C-means membership function. Simultaneously for the efficient clustering method the convergence criteria are set. On the whole the proposed technique yields more accurate results and that gives an edge over other techniques. This proposed algorithm result compared with other algorithms like fuzzy c means algorithm and PSO algorithm.

  15. 求解柔性作业车间调度问题的VEDFA算法与实现%VEDFA algorithm for flexible job-shop scheduling problem and its implementation

    Institute of Scientific and Technical Information of China (English)

    孙斌; 余杰; 吉卫喜; 王煜

    2015-01-01

    针对柔性作业车间调度问题(Flexible Job-Shop Problem,FJSP)的特点以及求解方法,提出了病毒离散萤火虫算法(Virus co-Evolution Discrete Firefly Algorithm,VEDFA)来求解FJSP.该算法采用启发式规则与随机的方法产生初始种群,并对标准萤火虫算法进行改进,提出一种离散萤火虫算法.将病毒遗传算法中的病毒个体引入离散萤火虫算法(Discrete Firefly Algorithm,DFA)以加强局部搜索能力与动态搜索能力,并使用Interchange邻域结构的局部搜索来改善最优解.最后通过实验证明了该算法可以很好地解决FJSP.

  16. Wavelength switching in an optical klystron

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, K.W.; Smith, T.I. [Stanford Univ., CA (United States)

    1995-12-31

    A symmetric optical klystron consists of two identical undulator sections separated a dispersive section. For a device of a given length, an optical klystron is capable of producing much more bunching, and therefore more gain, than a traditional undulator. Another consequence of introducing dispersion between two undulator sections is that the overall spontaneous radiation pattern results from the interference between the two undulator sections, and as such resembles a standard undulator radiation pattern modulated by a sinusoidal interference term. The presence of several wavelength peaks in the spontaneous lineshape implies an equal number of peaks in the gain spectrum. If the strength of the dispersion section is adjusted to provide nearly equal gain on the two largest of these peaks, then they will compete, and the FEL may switch wavelengths based on noise, cavity length, or other perturbations. We provide the first observations of this behavior, using the FIREFLY system at the Stanford Picosecond FEL Center. In FIREFLY, relative wavelength switching by more than 3%--more than twice the laser linewidth-has been observed by varying dispersion section strength, while at intermediate points stable switching has also been observed as a function of cavity length.

  17. Bioluminescent system for dynamic imaging of cell and animal behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  18. Sync the emerging science of spontaneous order

    CERN Document Server

    Strogatz, Steven

    2003-01-01

    At the heart of the universe is a steady, insistent beat, the sound of cycles in sync. Along the tidal rivers of Malaysia, thousands of fireflies congregate and flash in unison; the moon spins in perfect resonance with its orbit around the earth; our hearts depend on the synchronous firing of ten thousand pacemaker cells. While the forces that synchronize the flashing of fireflies may seem to have nothing to do with our heart cells, there is in fact a deep connection. Synchrony is a science in its infancy, and Strogatz is a pioneer in this new frontier in which mathematicians and physicists attempt to pinpoint just how spontaneous order emerges from chaos. From underground caves in Texas where a French scientist spent six months alone tracking his sleep-wake cycle, to the home of a Dutch physicist who in 1665 discovered two of his pendulum clocks swinging in perfect time, this fascinating book spans disciplines, continents, and centuries. Engagingly written for readers of books such as Chaos and The Elegant ...

  19. Activity of the TonEBP/OREBP transactivation domain varies directly with extracellular NaCl concentration.

    Science.gov (United States)

    Ferraris, Joan D; Williams, Chester K; Persaud, Prita; Zhang, Zheng; Chen, Ye; Burg, Maurice B

    2002-01-22

    Hypertonicity-induced binding of the transcription factor TonEBP/OREBP to its cognate DNA element, ORE/TonE, is associated with increased transcription of several osmotically regulated genes. Previously, it was found that hypertonicity rapidly causes nuclear translocation and phosphorylation of TonEBP/OREBP and, more slowly, increases TonEBP/OREBP abundance. Also, the C terminus of TonEBP/OREBP was found to contain a transactivation domain (TAD). We have now tested for tonicity dependence of the TAD activity of the 983 C-terminal amino acids of TonEBP/OREBP. HepG2 cells were cotransfected with a reporter construct and one of several TAD expression vector constructs. The reporter construct contained GAL4 DNA binding elements, a minimal promoter, and the Photinus luciferase gene. TAD expression vectors generate chimeras comprised of the GAL4 DNA binding domain fused to (i) the 983 C-terminal amino acids of TonEBP/OREBP, (ii) 17 glutamine residues, (iii) the TAD of c-Jun, or (iv) no TAD. All TAD-containing chimeras were functional at normal extracellular osmolality (300 mosmol/kg), but the activity only of the chimera containing the 983 C-terminal amino acids of TonEBP/OREBP varied with extracellular NaCl concentration, decreasing by >80% at 200 mosmol/kg and increasing 8-fold at 500 mosmol/kg. The chimera containing the 983 C-terminal amino acids of TonEBP/OREBP was constitutively localized to the nucleus and showed tonicity-dependent posttranslational modification consistent with phosphorylation. The activity at 500 mosmol/kg was reduced by herbimycin, a tyrosine kinase inhibitor and by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, a protein kinase CK2 inhibitor. Thus, the 983 C-terminal amino acids of TonEBP/OREBP contain a TAD that is regulated osmotically, apparently by tonicity-dependent phosphorylation.

  20. A Dual Luciferase Reporter System for B. burgdorferi Measures Transcriptional Activity during Tick-Pathogen Interactions

    Directory of Open Access Journals (Sweden)

    Philip P. Adams

    2017-05-01

    Full Text Available Knowledge of the transcriptional responses of vector-borne pathogens at the vector-pathogen interface is critical for understanding disease transmission. Borrelia (Borreliella burgdorferi, the causative agent of Lyme disease in the United States, is transmitted by the bite of infected Ixodes sp. ticks. It is known that B. burgdorferi has altered patterns of gene expression during tick acquisition, persistence and transmission. Recently, we and others have discovered in vitro expression of RNAs found internal, overlapping, and antisense to annotated open reading frames in the B. burgdorferi genome. However, there is a lack of molecular genetic tools for B. burgdorferi for quantitative, strand-specific, comparative analysis of these transcripts in distinct environments such as the arthropod vector. To address this need, we have developed a dual luciferase reporter system to quantify B. burgdorferi promoter activities in a strand-specific manner. We demonstrate that constitutive expression of a B. burgdorferi codon-optimized Renilla reniformis luciferase gene (rlucBb allows normalization of the activity of a promoter of interest when fused to the B. burgdorferi codon-optimized Photinus pyralis luciferase gene (flucBb on the same plasmid. Using the well characterized, differentially regulated, promoters for flagellin (flaBp, outer surface protein A (ospAp and outer surface protein C (ospCp, we document the efficacy of the dual luciferase system for quantitation of promoter activities during in vitro growth and in infected ticks. Cumulatively, the dual luciferase method outlined herein is the first dual reporter system for B. burgdorferi, providing a novel and highly versatile approach for strand-specific molecular genetic analyses.

  1. Distinctive properties of the 5'-untranslated region of human hsp70 mRNA.

    Science.gov (United States)

    Rubtsova, Maria P; Sizova, Daria V; Dmitriev, Sergei E; Ivanov, Dmitri S; Prassolov, Vladimir S; Shatsky, Ivan N

    2003-06-20

    A relaxed cap-dependence of translation of the mRNA-encoding mammalian heat shock protein Hsp70 may suggest that its 5'-untranslated region (UTR) possesses an internal ribosome entry site (IRES). In this study, this possibility has been tested in transfected cells using plasmids that express dicistronic mRNAs. Using a reporter gene construct, Renilla luciferase/Photinus pyralis luciferase, we show that the 216-nt long 5'-UTR of Hsp70 mRNA acts as an IRES that directs ribosomes to the downstream start codon by a cap-independent mechanism. The relative activity of this IRES (100-fold over the empty vector) is similar to that of the classical picornaviral IRESs. Additional controls indicate that this high expression of the downstream reporter is not due to readthrough from the upstream cistron, nor is it due to translation of cryptic monocistronic transcripts. The effect of small deletions within the 5'-UTR of Hsp70 mRNA on the IRES activity varies in dependence on their position within the 5'-UTR sequence. With the exception of deletion of nt 33-50, it is small for the 5'-terminal half of the 5'-UTR and rather strong for the 3'-terminal section. However, neither of these small deletions abolishes the IRES activity completely. Excision of larger sections (>50 nt) by truncation of the 5'-UTR from the 5'-end or by internal deleting results in a dramatic impairment of the IRES function. Taken together, these data suggest that the IRES activity of the 5'-UTR of Hsp70 mRNA requires integrity of almost the entire sequence of the 5'-UTR. The data are discussed in terms of a model that allows a three-dimensional rather than linear mode of selection of the initiation region surrounding the start codon of Hsp70 mRNA.

  2. Expression of thermostable recombiant Luciola lateralis luciferase and development of heat-stable pyrosequencing system%耐热荧光素酶的表达及热稳定焦磷酸测序体系的建立

    Institute of Scientific and Technical Information of China (English)

    徐澍; 邹秉杰; 王建平; 武海萍; 周国华

    2012-01-01

    Pyrosequencing is a tool based on bioluminescence reaction for real-time analyzing DNA sequences. The sensitivity of pyrosequencing mainly depends on luciferase in reaction mixture. However, the instability of pyrosequencing reagents caused by fragile wild Photinus pyralis luciferase (PpL) in conventional pyrosequencing usually leads to unsatisfied results, which limits the application of pyrosequencing. In order to improve the stability of pyrosequencing reagents, the coding sequences of mutant thermostable Luciola lateralis luciferase (rt-LlL) was synthesized, and inserted into the plasmid of pET28a(+) to express the thermostable rt-LlL with a 6×His-tag in the N terminal. The purified rt-LlL with the molecular mass of 60 kDa was obtained by Ni-affinity chromatography. The specific activity of rt-LlL was determined as 4.29×1010 RLU/mg. Moreover, the thermostability of rt-LlL was investigated, and the results showed that rt-LlL had activity at 50 ℃, and remained 90% of activity after incubated at 40 ℃ for 25 min. Finally, rt-LlL was used to substitute commercial Photinus pyralis luciferase in conventional pyrosequencing reagent to get thermostable pyrosequencing reagent. Comparing with conventional pyrosequencing reagent, the thermostable pyrosequencing reagent is more stable, and it's activity would not lose when incubated at 37 ℃ for 1 h. This study laid foundation of establishing reliable and stable pyrosequencing system which would be applied in Point-of-Care Testing.%焦磷酸测序是一种基于生物发光反应的实时DNA序列测定技术,其反应体系中的荧光素酶决定测序反应的灵敏度.传统焦测序反应使用的是野生型北美荧光素酶Photinus pyralis luciferase (PpL),该酶热稳定性较差,因此由该酶配制的焦磷酸测序反应体系对热不稳定,影响焦磷酸测序的灵敏度.为了建立热稳定的焦磷酸测序反应体系,全合成了耐热突变日本萤火虫荧光素酶的编码序列,并将

  3. Glu311 and Arg337 Stabilize a Closed Active-site Conformation and Provide a Critical Catalytic Base and Countercation for Green Bioluminescence in Beetle Luciferases.

    Science.gov (United States)

    Viviani, V R; Simões, A; Bevilaqua, V R; Gabriel, G V M; Arnoldi, F G C; Hirano, T

    2016-08-30

    Beetle luciferases elicit the emission of different bioluminescence colors from green to red. Whereas firefly luciferases emit yellow-green light and are pH-sensitive, undergoing a typical red-shift at acidic pH and higher temperatures and in the presence of divalent heavy metals, click beetle and railroadworm luciferases emit a wider range of colors from green to red but are pH-independent. Despite many decades of study, the structural determinants and mechanisms of bioluminescence colors and pH sensitivity remain enigmatic. Here, through modeling studies, site-directed mutagenesis, and spectral and kinetic studies using recombinant luciferases from the three main families of bioluminescent beetles that emit different colors of light (Macrolampis sp2 firefly, Phrixotrix hirtus railroadworm, and Pyrearinus termitilluminans click beetle), we investigated the role of E311 and R337 in bioluminescence color determination. All mutations of these residues in firefly luciferase produced red mutants, indicating that the preservation of opposite charges and the lengths of the side chains of E311 and R337 are essential for keeping a salt bridge that stabilizes a closed hydrophobic conformation favorable for green light emission. Kinetic studies indicate that residue R337 is important for binding luciferin and creating a positively charged environment around excited oxyluciferin phenolate. In Pyrearinus green-emitting luciferase, the R334A mutation causes a 27 nm red-shift, whereas in Phrixotrix red-emitting luciferase, the L334R mutation causes a blue-shift that is no longer affected by guanidine. These results provide compelling evidence that the presence of arginine at position 334 is essential for blue-shifting the emission spectra of most beetle luciferases. Therefore, residues E311 and R337 play both structural and catalytic roles in bioluminescence color determination, by stabilizing a closed hydrophobic conformation favorable for green light emission, and also

  4. Studies in swarm intelligence techniques for annual crop planning problem in a new irrigation scheme

    Directory of Open Access Journals (Sweden)

    Adewumi, Aderemi Oluyinka

    2013-11-01

    Full Text Available Annual crop planning (ACP is an NP-Hard type optimisation problem in agricultural planning. It involves finding optimal solutions for the seasonal allocations of a limited amount of agricultural land among the various competing crops that need to be grown on it. This study investigates the effectiveness of employing three relatively new Swarm Intelligence (SI techniques in determining solutions to an ACP problem at a new irrigation scheme. The SI metaheuristics studied include Cuckoo Search (CS, Firefly Algorithm (FA, and Glow-worm Swarm Optimisation (GSO. The solutions determined by these SI techniques are compared against the solutions of Genetic Algorithm (GA, another population-based metaheuristic technique. This helps to determine the relative merits of the solutions found by the SI techniques. The results show that the SI algorithms delivered solutions superior to those of GA in determining solutions to the ACP problem at a new irrigation scheme.

  5. Constructing and Analyzing Fusion Promoter of Partial Sericin 1 and Bombyx A3 Cytoplasmic Actin

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Previous report showed that the 209 bp DNA sequence upstream of the sericin 1 transcriptional start site (-586 to -378 bp) is involved in promoting transcription and responsible for the tissue specificity of sericin 1 promoter in silkworm Bombyx mori. In the present study, this 209 bp sequence exhibited enhancive effect by assembling in two different locations of ubiquitous Bombyx A3 cytoplasmic actin promoter. Sf-9 cells were transfected with recombinant plasmids using Cellfectin reagent. Firefly luciferase gene located downstream of fusion promoter was considered as a reporter, whereas the activity of the co-transfected Renilla luciferase gene (pGL2-SV40) provides an internal control. This 209 bp region up-regulates the strength of A3 promoter significantly (P < 0.01) when it enters into A3 promoter with respect to the position in sericin 1 gene promoter. This 209-bp fragment was almost functionless when being located upstream of A3 promoter.

  6. Application of ATP measurements to the microbiological evaluation of a petroleum reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Jones, P.M.

    1981-06-01

    The objective of the work reported in this document was to determine whether the bioluminescent luciferin/luciferase based adenosine triphosphate (ATP) assay could be used as a rapid field tests for determining the presence and numbers of microorganisms in oil field fluids. The ATP-photometric technique employed is based on the ATP-mediated bioluminescent oxidation of firefly luciferin. Light production is stoichiometrically related to ATP concentration; ATP concentration is related to numbers of living organisms present in a sample. Samples used in this study comprised reservoir fluids collected from several Southern California oilfields. Based on experimental evidence, it was concluded that the ATP assay could be profitably applied to Microbially Enhanced Oil Recovery (MEOR) process monitoring and control. The theoretical basis for the assay, field-usage methodologies, and fundamentals of data interpretation are presented to make the document usable as a field manual.

  7. Bioluminescence Methods for Assaying Kinases in Quantitative High-Throughput Screening (qHTS) Format Applied to Yes1 Tyrosine Kinase, Glucokinase, and PI5P4Kα Lipid Kinase.

    Science.gov (United States)

    Davis, Mindy I; Auld, Douglas S; Inglese, James

    2016-01-01

    Assays in which the detection of a biological phenomenon is coupled to the production of bioluminescence by luciferase have gained widespread use. As firefly luciferases (FLuc) and kinases share a common substrate (ATP), coupling of a kinase to FLuc allows for the amount of ATP remaining following a kinase reaction to be assessed by quantitating the amount of luminescence produced. Alternatively, the amount of ADP produced by the kinase reaction can be coupled to FLuc through a two-step process. This chapter describes the bioluminescent assays that were developed for three classes of kinases (lipid, protein, and metabolic kinases) and miniaturized to 1536-well format, enabling their use for quantitative high-throughput (qHTS) of small-molecule libraries.

  8. Bioluminescence microscopy: application to ATP measurements in single living cells

    Science.gov (United States)

    Brau, Frederic; Helle, Pierre; Bernengo, Jean C.

    1997-12-01

    Bioluminescence microscopy can be used to measure intracellular cofactors and ionic concentrations (Ca2+, K+, ATP, NADH), as an alternative to micro- spectrophotometry and micro-fluorimetry, due to the development of sensitive detectors (cooled photomultipliers tubes and CCD). The main limitation comes from the very small and brief intensity of the emitted light. Our instrumentation based on an inverted microscope, equipped with high aperture immersion lenses is presented. Light intensity measurements are carried out through a photomultiplier sorted for low dark current and cooled at -5 degree(s)C to reduce thermal noise. Our first aim is to quantify ATP on single living cells using the firefly luciferin-luciferase couple. Experimental and kinetic aspects are presented to emphasize the potentialities of the technique.

  9. Different types of maximum power point tracking techniques for renewable energy systems: A survey

    Science.gov (United States)

    Khan, Mohammad Junaid; Shukla, Praveen; Mustafa, Rashid; Chatterji, S.; Mathew, Lini

    2016-03-01

    Global demand for electricity is increasing while production of energy from fossil fuels is declining and therefore the obvious choice of the clean energy source that is abundant and could provide security for development future is energy from the sun. In this paper, the characteristic of the supply voltage of the photovoltaic generator is nonlinear and exhibits multiple peaks, including many local peaks and a global peak in non-uniform irradiance. To keep global peak, MPPT is the important component of photovoltaic systems. Although many review articles discussed conventional techniques such as P & O, incremental conductance, the correlation ripple control and very few attempts have been made with intelligent MPPT techniques. This document also discusses different algorithms based on fuzzy logic, Ant Colony Optimization, Genetic Algorithm, artificial neural networks, Particle Swarm Optimization Algorithm Firefly, Extremum seeking control method and hybrid methods applied to the monitoring of maximum value of power at point in systems of photovoltaic under changing conditions of irradiance.

  10. Integrated Flight Trajectory Control Development Program.

    Science.gov (United States)

    1981-08-01

    H mt4V m non 0 )w Mp t ) .4 w’ ) sOi =) U-C ) 1*- 64*- 0 L, 1 * ) *~U c 3to~ u) uO f 0w -4. O1 I4) 00 r 40 41 4.) Oc W ko .0 OC Ow 0 .41 urLu E 63 The...AFKY3200--d NO CALL 0 soYES WAI NO W/o ABORTED? AlEnIRN 1AMORTOO. Figure A-5. IFTC/Firefly II Integration Flow Charts (3 of 21) 91 860T YS EPMI Mm EO...SESS ATS-1 FC)G FiueA5YFCFrfyI an gato Flow hrs(3o1 W~m L c H" /10YE m ya W"M TUM RA= AUM AJWAT wo ITEMM-1 PC ns RM FNELATM COMKW 20 Cr*FWE PMJ. y

  11. Adenosine triphosphate in cholinergic vesicles isolated from the electric organ of Electrophorus electricus.

    Science.gov (United States)

    Zimmermann, H; Denston, C R

    1976-07-30

    Synaptic vesicles have been isolated from the electirc organ of the bony fish Electrophorus electricus using sucrose step gradients and zonal centrifugation. Although the acetylcholine (ACh) content of the Electrophorus electric organ is only 2% of that of Torpedo, ACh and ATP can readily be measured in the peak fractions using the leech microassay and the firefly luciferin luciferase assay respectively. The protein content of the vesicle fraction in experiments with Electrophorus was much higher than with Torpedo, but a possible contamination of this fraction with mitochondrial or cytoplasmic particles could be excluded. The ACh to ATP ratio of 10.8 is close to that found for cholinergic vesicles isolated from Torpedo and also to that of other amine storing granules.

  12. 3rd International Conference on Harmony Search Algorithm

    CERN Document Server

    2017-01-01

    This book presents state-of-the-art technical contributions based around one of the most successful evolutionary optimization algorithms published to date: Harmony Search. Contributions span from novel technical derivations of this algorithm to applications in the broad fields of civil engineering, energy, transportation & mobility and health, among many others and focus not only on its cross-domain applicability, but also on its core evolutionary operators, including elements inspired from other meta-heuristics. The global scientific community is witnessing an upsurge in groundbreaking, new advances in all areas of computational intelligence, with a particular flurry of research focusing on evolutionary computation and bio-inspired optimization. Observed processes in nature and sociology have provided the basis for innovative algorithmic developments aimed at leveraging the inherent capability to adapt characterized by various animals, including ants, fireflies, wolves and humans. However, it is the beha...

  13. Intuitionistic Trapezoidal Fuzzy Group Decision-Making Based on Prospect Choquet Integral Operator and Grey Projection Pursuit Dynamic Cluster

    Directory of Open Access Journals (Sweden)

    Jiahang Yuan

    2017-01-01

    Full Text Available In consideration of the interaction among attributes and the influence of decision makers’ risk attitude, this paper proposes an intuitionistic trapezoidal fuzzy aggregation operator based on Choquet integral and prospect theory. With respect to a multiattribute group decision-making problem, the prospect value functions of intuitionistic trapezoidal fuzzy numbers are aggregated by the proposed operator; then a grey relation-projection pursuit dynamic cluster method is developed to obtain the ranking of alternatives; the firefly algorithm is used to optimize the objective function of projection for obtaining the best projection direction of grey correlation projection values, and the grey correlation projection values are evaluated, which are applied to classify, rank, and prefer the alternatives. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.

  14. 糖尿病风险识别系统的研究与开发%Research and Development of Diabetes Mellitus Risk Identification System

    Institute of Scientific and Technical Information of China (English)

    吴雨晨; 张琪君

    2016-01-01

    This paper uses the Naive Bayesian classification method and firefly algorithm to designed a diabetes diagno-sis model,and develops a diabetes risk identification system based on this model,in order to help medical staff to diagnose diabetes,and improves the accuracy and efficiency of diagnosis.%利用朴素贝叶斯分类方法和萤火虫算法构造糖尿病诊断模型,并基于此模型开发了一个糖尿病风险识别系统,能有效辅助医护人员进行糖尿病诊断,提高诊断的准确率和效率。

  15. Structure and weights optimisation of a modified Elman network emotion classifier using hybrid computational intelligence algorithms: a comparative study

    Science.gov (United States)

    Sheikhan, Mansour; Abbasnezhad Arabi, Mahdi; Gharavian, Davood

    2015-10-01

    Artificial neural networks are efficient models in pattern recognition applications, but their performance is dependent on employing suitable structure and connection weights. This study used a hybrid method for obtaining the optimal weight set and architecture of a recurrent neural emotion classifier based on gravitational search algorithm (GSA) and its binary version (BGSA), respectively. By considering the features of speech signal that were related to prosody, voice quality, and spectrum, a rich feature set was constructed. To select more efficient features, a fast feature selection method was employed. The performance of the proposed hybrid GSA-BGSA method was compared with similar hybrid methods based on particle swarm optimisation (PSO) algorithm and its binary version, PSO and discrete firefly algorithm, and hybrid of error back-propagation and genetic algorithm that were used for optimisation. Experimental tests on Berlin emotional database demonstrated the superior performance of the proposed method using a lighter network structure.

  16. Nature-inspired computation in engineering

    CERN Document Server

    2016-01-01

    This timely review book summarizes the state-of-the-art developments in nature-inspired optimization algorithms and their applications in engineering. Algorithms and topics include the overview and history of nature-inspired algorithms, discrete firefly algorithm, discrete cuckoo search, plant propagation algorithm, parameter-free bat algorithm, gravitational search, biogeography-based algorithm, differential evolution, particle swarm optimization and others. Applications include vehicle routing, swarming robots, discrete and combinatorial optimization, clustering of wireless sensor networks, cell formation, economic load dispatch, metamodeling, surrogated-assisted cooperative co-evolution, data fitting and reverse engineering as well as other case studies in engineering. This book will be an ideal reference for researchers, lecturers, graduates and engineers who are interested in nature-inspired computation, artificial intelligence and computational intelligence. It can also serve as a reference for relevant...

  17. Optimisation of ATP determination in drinking water

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    Adenosine Triphosphate (ATP) can be used as a relative measure of cell activity, and is measured by the light output from the reaction between luciferin and ATP catalyzed by firefly luciferase. The measurement has potential as a monitoring and surveillance tool within drinking water distribution......, since the method is very sensitive (detects 0.5 ng ATP/L) and results are obtained within minutes. When calculating the ATP value a number of parameters need to be considered. These were investigate by use of two different reagent kits (PCP-kit and Lumin(ATE)/Lumin(EX)-kit), internal standard...... and an Advance Coupe luminometer. The investigations showed a 60 times higher response of the PCP-kit, making it more suitable for measurement of samples with low ATP content. ATP-standard dilutions prepared in tap water were stable for at least 15 months when stored frozen at -80ºC, and storage of large...

  18. Intratumoral DNA electroporation induces anti-tumor immunity and tumor regression.

    Science.gov (United States)

    Radkevich-Brown, Olga; Piechocki, Marie P; Back, Jessica B; Weise, Amy M; Pilon-Thomas, Shari; Wei, Wei-Zen

    2010-03-01

    In situ expression of a foreign antigen and an immune-modulating cytokine by intratumoral DNA electroporation was tested as a cancer therapy regimen. Transgene expression in the tumors was sustained for 2-3 weeks after intratumoral electroporation with mammalian expression plasmid containing firefly luciferase cDNA. Electroporation with cDNA encoding tetanus toxin fragment C (TetC) induced tetanus toxin-binding antibody, demonstrating immune recognition of the transgene product. Intratumoral electroporation with TetC and IL-12 cDNA after mice were treated with CD25 mAb to remove regulatory T cells induced IFN-gamma producing T-cell response to tumor-associated antigen, heavy inflammatory infiltration, regression of established tumors and immune memory to protect mice from repeated tumor challenge. Intratumoral expression of immune-modulating molecules may be most suitable in the neoadjuvant setting to enhance the therapeutic efficacy and provide long-term protection.

  19. Optimisation of ATP determination in drinking water

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Albrechtsen, Hans-Jørgen

    Adenosine Triphosphate (ATP) can be used as a relative measure of cell activity, and is measured by the light output from the reaction between luciferin and ATP catalyzed by firefly luciferase. The measurement has potential as a monitoring and surveillance tool within drinking water distribution......, since the method is very sensitive (detects 0.5 ng ATP/L) and results are obtained within minutes. When calculating the ATP value a number of parameters need to be considered. These were investigate by use of two different reagent kits (PCP-kit and Lumin(ATE)/Lumin(EX)-kit), internal standard...... and an Advance Coupe luminometer. The investigations showed a 60 times higher response of the PCP-kit, making it more suitable for measurement of samples with low ATP content. ATP-standard dilutions prepared in tap water were stable for at least 15 months when stored frozen at -80ºC, and storage of large...

  20. Setup of IN VIVO Breast Cancer Models for Nanodrug Testing

    DEFF Research Database (Denmark)

    Schifter, Søren

    2013-01-01

    Synthetic lethality is a promising concept for future cancer treatment and using siRNAs as the synthetic lethal drug component allows for also covering the space considered as non-druggable by conventional small molecule drugs. Systemic administration of naked siRNA, however, does not result...... for detection of the primary tumor and metastasis and the efficacy of siRNA delivery is measured by reporter gene-targeting siRNAs and in vivo imaging. The use of a uniform siRNA not affecting cellular processes would allow for standardized assessment of siRNA delivery to cancer cells without interferences via...... differential knockdown efficacies and the readout can directly be performed by quantitative imaging using a Caliper IVIS system. In one line of experiments, we engineered non-metastatic MCF-7 breast cancer cells to express the luminescent reporter firefly luciferase (Luc2) along with a pro-metastatic micro...

  1. Development of bioluminescent chick chorioallantoic membrane (CAM) models for primary pancreatic cancer cells: a platform for drug testing.

    Science.gov (United States)

    Rovithi, Maria; Avan, Amir; Funel, Niccola; Leon, Leticia G; Gomez, Valentina E; Wurdinger, Thomas; Griffioen, Arjan W; Verheul, Henk M W; Giovannetti, Elisa

    2017-03-17

    The aim of the present study was to develop chick-embryo chorioallantoic membrane (CAM) bioluminescent tumor models employing low passage cell cultures obtained from primary pancreatic ductal adenocarcinoma (PDAC) cells. Primary PDAC cells transduced with lentivirus expressing Firefly-luciferase (Fluc) were established and inoculated onto the CAM membrane, with >80% engraftment. Fluc signal reliably correlated with tumor growth. Tumor features were evaluated by immunohistochemistry and genetic analyses, including analysis of mutations and mRNA expression of PDAC pivotal genes, as well as microRNA (miRNA) profiling. These studies showed that CAM tumors had histopathological and genetic characteristic comparable to the original tumors. We subsequently tested the modulation of key miRNAs and the activity of gemcitabine and crizotinib on CAM tumors, showing that combination treatment resulted in 63% inhibition of tumor growth as compared to control (p testing, providing insights on molecular mechanisms underlying antitumor activity of new drugs/combinations.

  2. Extraction and purification of a luminiferous substance from the luminous mushroom Mycena chlorophos

    Science.gov (United States)

    Hayashi, Shuhei; Fukushima, Ryuichi; Wada, Naohisa

    2012-01-01

    Bioluminescence has attracted considerable attention in the area of biophysics, primarily because the phenomenon can fundamentally be interpreted as the conversion of chemical to light energy. Although the molecular mechanisms underlying luminescence have been studied extensively in fireflies and bacteria, few studies have been undertaken in luminous fungi. This relative lack of information is likely due to the absence of a common and species-specific reaction-type in the luminous fungi examined to date. We recently succeeded in extracting, for the first time, a luminiferous substance from the fungus Mycena chlorophos. The substance was purified and characterized according to its chemical and optical properties. It is hoped that this information will facilitate the clarification of a novel molecular mechanism in fungal bioluminescence systems. PMID:27493527

  3. Spatial Distribution of Transgenic Protein After Gene Electrotransfer to Porcine Muscle

    DEFF Research Database (Denmark)

    Spanggaard, Iben; Corydon, Thomas; Hojman, Pernille

    2012-01-01

    Abstract Gene electrotransfer is an effective nonviral technique for delivery of plasmid DNA into tissues. From a clinical perspective, muscle is an attractive target tissue as long-term, high-level transgenic expression can be achieved. Spatial distribution of the transgenic protein following gene...... electrotransfer to muscle in a large animal model has not yet been investigated. In this study, 17 different doses of plasmid DNA (1-1500 μg firefly luciferase pCMV-Luc) were delivered in vivo to porcine gluteal muscle using electroporation. Forty-eight hours post treatment several biopsies were obtained from...... each transfection site in order to examine the spatial distribution of the transgenic product. We found a significantly higher luciferase activity in biopsies from the center of the transfection site compared to biopsies taken adjacent to the center, 1 and 2 cm along muscle fiber orientation (p...

  4. Mathematical Modelling and Parameter Optimization of Pulsating Heat Pipes

    CERN Document Server

    Yang, Xin-She; Luan, Tao; Koziel, Slawomir

    2014-01-01

    Proper heat transfer management is important to key electronic components in microelectronic applications. Pulsating heat pipes (PHP) can be an efficient solution to such heat transfer problems. However, mathematical modelling of a PHP system is still very challenging, due to the complexity and multiphysics nature of the system. In this work, we present a simplified, two-phase heat transfer model, and our analysis shows that it can make good predictions about startup characteristics. Furthermore, by considering parameter estimation as a nonlinear constrained optimization problem, we have used the firefly algorithm to find parameter estimates efficiently. We have also demonstrated that it is possible to obtain good estimates of key parameters using very limited experimental data.

  5. Development of an Axial Flux MEMS BLDC Micromotor with Increased Efficiency and Power Density

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ding

    2015-06-01

    Full Text Available This paper presents a rigorous design and optimization of an axial flux microelectromechanical systems (MEMS brushless dc (BLDC micromotor with dual rotor improving both efficiency and power density with an external diameter of only around 10 mm. The stator is made of two layers of windings by MEMS technology. The rotor is developed by film permanent magnets assembled over the rotor yoke. The characteristics of the MEMS micromotor are analyzed and modeled through a 3-D magnetic equivalent circuit (MEC taking the leakage flux and fringing effect into account. Such a model yields a relatively accurate prediction of the flux in the air gap, back electromotive force (EMF and electromagnetic torque, whilst being computationally efficient. Based on 3-D MEC model the multi-objective firefly algorithm (MOFA is developed for the optimal design of this special machine. Both 3-D finite element (FE simulation and experiments are employed to validate the MEC model and MOFA optimization design.

  6. Titration-based screening for evaluation of natural product extracts: identification of an aspulvinone family of luciferase inhibitors

    Science.gov (United States)

    Cruz, Patricia G.; Auld, Douglas S.; Schultz, Pamela J.; Lovell, Scott; Battaile, Kevin P.; MacArthur, Ryan; Shen, Min; Tamayo-Castillo, Giselle; Inglese, James; Sherman, David H.

    2011-01-01

    The chemical diversity of nature has tremendous potential for discovery of new molecular probes and medicinal agents. However, sensitivity of HTS assays to interfering components of crude extracts derived from plants, macro- and microorganisms has curtailed their use in lead discovery efforts. Here we describe a process for leveraging the concentration-response curves (CRCs) obtained from quantitative HTS to improve the initial selection of “actives” from a library of partially fractionated natural product extracts derived from marine actinomycetes and fungi. By using pharmacological activity, the first-pass CRC paradigm aims to improve the probability that labor-intensive subsequent steps of re-culturing, extraction and bioassay-guided isolation of active component(s) target the most promising strains and growth conditions. We illustrate how this process identified a family of fungal metabolites as potent inhibitors of firefly luciferase, subsequently resolved in molecular detail by x-ray crystallography. PMID:22118678

  7. Sensor fusion IV: Control paradigms and data structures; Proceedings of the Meeting, Boston, MA, Nov. 12-15, 1991

    Science.gov (United States)

    Schenker, Paul S. (Editor)

    1992-01-01

    Various papers on control paradigms and data structures in sensor fusion are presented. The general topics addressed include: decision models and computational methods, sensor modeling and data representation, active sensing strategies, geometric planning and visualization, task-driven sensing, motion analysis, models motivated biology and psychology, decentralized detection and distributed decision, data fusion architectures, robust estimation of shapes and features, application and implementation. Some of the individual subjects considered are: the Firefly experiment on neural networks for distributed sensor data fusion, manifold traversing as a model for learning control of autonomous robots, choice of coordinate systems for multiple sensor fusion, continuous motion using task-directed stereo vision, interactive and cooperative sensing and control for advanced teleoperation, knowledge-based imaging for terrain analysis, physical and digital simulations for IVA robotics.

  8. Light without substrate amendment: the bacterial luciferase gene cassette as a mammalian bioreporter

    Science.gov (United States)

    Close, Dan M.; Xu, Tingting; Smartt, Abby E.; Jegier, Pat; Ripp, Steven A.; Sayler, Gary S.

    2011-06-01

    Bioluminescent production represents a facile method for bioreporter detection in mammalian tissues. The lack of endogenous bioluminescent reactions in these tissues allows for high signal to noise ratios even at low signal strength compared to fluorescent signal detection. While the luciferase enzymes commonly employed for bioluminescent detection are those from class Insecta (firefly and click beetle luciferases), these are handicapped in that they require concurrent administration of a luciferin compound to elicit a bioluminescent signal. The bacterial luciferase (lux) gene cassette offers the advantages common to other bioluminescent proteins, but is simultaneously capable of synthesizing its own luciferin substrates using endogenously available cellular compounds. The longstanding shortcoming of the lux cassette has been its recalcitrance to function in the mammalian cellular environment. This paper will present an overview of the work completed to date to overcome this limitation and provide examples of mammalian lux-based bioreporter technologies that could provide the framework for advanced, biomedically relevant real-time sensor development.

  9. Lucciole e farfalle per un’immagine dialettica

    Directory of Open Access Journals (Sweden)

    Elisabetta Villari

    2012-05-01

    Full Text Available This text as a postscript to the essay by Georges Didi Huberman who invites us to consider overturning a note metaphor of the disappearance of fireflies Pasolini speaks of "des Lucioles Survivance" Didi Huberman's provocation  is to resume the expression of Pasolini's writings  viewed by Guy Debord and Walter Benjamin refers to the political situation in Italy today and would like to make us reflect on a very topical subject as Berlusconi's Italy and a possible "resistance". This project intends to make a story pointing out that this symptom Sciascia had already used the metaphor about the Moro murder in the seventies after the death of Pasolini and it is important to remember and retrace your policy for this analysis that the book invites us to do, but do not forget some crucial steps to avoid the risk of the “eternal return of the same”.

  10. APPROACHES TO ENGINEER STABILITY OF BEETLE LUCIFERASES

    Directory of Open Access Journals (Sweden)

    Mikhail I. Koksharov

    2012-09-01

    Full Text Available Luciferase enzymes from fireflies and other beetles have many important applications in molecular biology, biotechnology, analytical chemistry and several other areas. Many novel beetle luciferases with promising properties have been reported in the recent years. However, actual and potential applications of wild-type beetle luciferases are often limited by insufficient stability or decrease in activity of the enzyme at the conditions of a particular assay. Various examples of genetic engineering of the enhanced beetle luciferases have been reported that successfully solve or alleviate many of these limitations. This mini-review summarizes the recent advances in development of mutant luciferases with improved stability and activity characteristics. It discusses the common limitations of wild-type luciferases in different applications and presents the efficient approaches that can be used to address these problems.

  11. Synthesis of unstable cyclic peroxides for chemiluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Bartoloni, Fernando H.; Oliveira, Marcelo A. de; Augusto, Felipe A.; Ciscato, Luiz Francisco M.L.; Bastos, Erick L.; Baader, Wilhelm J., E-mail: wjbaader@iq.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

    2012-11-15

    Cyclic four-membered ring peroxides are important high-energy intermediates in a variety of chemi and bioluminescence transformations. Specifically, a-peroxy lactones (1,2-dioxetanones) have been considered as model systems for efficient firefly bioluminescence. However, the preparation of such highly unstable compounds is extremely difficult and, therefore, only few research groups have been able to study the properties of these substances. In this study, the synthesis, purification and characterization of three 1,2-dioxetanones are reported and a detailed procedure for the known synthesis of diphenoyl peroxide, another important model compound for the chemical generation of electronically excited states, is provided. For most of these peroxides, the complete spectroscopic characterization is reported here for the first time. (author)

  12. Evaluation of the magnetic field requirements for nanomagnetic gene transfection

    Directory of Open Access Journals (Sweden)

    A. Fouriki

    2010-07-01

    Full Text Available The objective of this work was to examine the effects of magnet distance (and by proxy, field strength on nanomagnetic transfection efficiency. Methods: non-viral magnetic nanoparticle-based transfection was evaluated using both static and oscillating magnet arrays. Results: Fluorescence intensity (firefly luciferase of transfected H292 cells showed no increase using a 96-well NdFeB magnet array when the magnets were 5 mm from the cell culture plate or nearer. At 6 mm and higher, fluorescence intensity decreased systematically. Conclusion: In all cases, fluorescence intensity was higher when using an oscillating array compared to a static array. For distances closer than 5 mm, the oscillating system also outperformed Lipofectamine 2000™.

  13. Setup of IN VIVO Breast Cancer Models for Nanodrug Testing

    DEFF Research Database (Denmark)

    Schifter, Søren

    for detection of the primary tumor and metastasis and the efficacy of siRNA delivery is measured by reporter gene-targeting siRNAs and in vivo imaging. The use of a uniform siRNA not affecting cellular processes would allow for standardized assessment of siRNA delivery to cancer cells without interferences via......RNA/aptamer conjugates, or carriers such as liposome/chitosan/micelle spheres. As a first step towards testing of the efficacy of siRNA delivery in vivo via different conjugates and complexes, we aimed at developing a standardized breast cancer model system in mice. In this conception, a reporter gene is used...... differential knockdown efficacies and the readout can directly be performed by quantitative imaging using a Caliper IVIS system. In one line of experiments, we engineered non-metastatic MCF-7 breast cancer cells to express the luminescent reporter firefly luciferase (Luc2) along with a pro-metastatic micro...

  14. How to suppress undesired synchronization

    CERN Document Server

    Louzada, V H P; Andrade, J S; Herrmann, H J

    2012-01-01

    It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected ele...

  15. Learning from nature: Nature-inspired algorithms

    DEFF Research Database (Denmark)

    Albeanu, Grigore; Madsen, Henrik; Popentiu-Vladicescu, Florin

    2016-01-01

    During last decade, the nature has inspired researchers to develop new algorithms. The largest collection of nature-inspired algorithms is biology-inspired: swarm intelligence (particle swarm optimization, ant colony optimization, cuckoo search, bees' algorithm, bat algorithm, firefly algorithm etc...... on collective social behaviour of organisms, researchers have developed optimization strategies taking into account not only the individuals, but also groups and environment. However, learning from nature, new classes of approaches can be identified, tested and compared against already available algorithms....... This work reviews the most effective nature-inspired algorithms and describes learning strategies based on nature oriented thinking. Examples and the benefits obtained from applying nature-inspired strategies in test generation, learners group optimization, and artificial immune systems for learning...

  16. Sensor fusion IV: Control paradigms and data structures; Proceedings of the Meeting, Boston, MA, Nov. 12-15, 1991

    Science.gov (United States)

    Schenker, Paul S. (Editor)

    1992-01-01

    Various papers on control paradigms and data structures in sensor fusion are presented. The general topics addressed include: decision models and computational methods, sensor modeling and data representation, active sensing strategies, geometric planning and visualization, task-driven sensing, motion analysis, models motivated biology and psychology, decentralized detection and distributed decision, data fusion architectures, robust estimation of shapes and features, application and implementation. Some of the individual subjects considered are: the Firefly experiment on neural networks for distributed sensor data fusion, manifold traversing as a model for learning control of autonomous robots, choice of coordinate systems for multiple sensor fusion, continuous motion using task-directed stereo vision, interactive and cooperative sensing and control for advanced teleoperation, knowledge-based imaging for terrain analysis, physical and digital simulations for IVA robotics.

  17. Dual-Color Click Beetle Luciferase Heteroprotein Fragment Complementation Assays

    Science.gov (United States)

    Villalobos, Victor; Naik, Snehal; Bruinsma, Monique; Dothager, Robin S.; Pan, Mei-Hsiu; Samrakandi, Mustapha; Moss, Britney; Elhammali, Adnan; Piwnica-Worms, David

    2010-01-01

    Summary Understanding the functional complexity of protein interactions requires mapping biomolecular complexes within the cellular environment over biologically-relevant time scales. Herein we describe a novel set of reversible, multicolored heteroprotein complementation fragments based on various firefly and click beetle luciferases that utilize the same substrate, D-luciferin. Luciferase heteroprotein fragment complementation systems enabled dual-color quantification of two discreet pairs of interacting proteins simultaneously or two distinct proteins interacting with a third shared protein in live cells. Using real-time analysis of click beetle green and click beetle red luciferase heteroprotein fragment complementation applied to β-TrCP, an E3-ligase common to the regulation of both β-catenin and IκBα, GSK3β was identified as a novel candidate kinase regulating IκBα processing. These dual-color protein interaction switches may enable directed dynamic analysis of a variety of protein interactions in living cells. PMID:20851351

  18. Energy-Efficient Train Operation Using Nature-Inspired Algorithms

    Directory of Open Access Journals (Sweden)

    Kemal Keskin

    2017-01-01

    Full Text Available A train operation optimization by minimizing its traction energy subject to various constraints is carried out using nature-inspired evolutionary algorithms. The optimization process results in switching points that initiate cruising and coasting phases of the driving. Due to nonlinear optimization formulation of the problem, nature-inspired evolutionary search methods, Genetic Simulated Annealing, Firefly, and Big Bang-Big Crunch algorithms were employed in this study. As a case study a real-like train and test track from a part of Eskisehir light rail network were modeled. Speed limitations, various track alignments, maximum allowable trip time, and changes in train mass were considered, and punctuality was put into objective function as a penalty factor. Results have shown that all three evolutionary methods generated effective and consistent solutions. However, it has also been shown that each one has different accuracy and convergence characteristics.

  19. Evolution of the complement system in protostomes revealed by de novo transcriptome analysis of six species of Arthropoda.

    Science.gov (United States)

    Sekiguchi, Reo; Nonaka, Masaru

    2015-05-01

    To elucidate the evolutionary history of the complement system in Arthropoda, de novo transcriptome analysis was performed with six species among the Chelicerata, Myriapoda, and Crustacea, and complement genes were identified based on their characteristic domain structures. Complement C3 and factor B (FB) were identified from a sea spider, a jumping spider, and a centipede, but not from a sea firefly or two millipede species. No additional complement components identifiable by their characteristic domain structures were found from any of these six species. These results together with genome sequence information for several species of the Hexapoda suggest that the common ancestor of the Arthropoda possessed a simple complement system comprising C3 and FB, and thus resembled the alternative pathway of the mammalian complement system. It was lost at least twice independently during the evolution of Arthropoda in the millipede lineage and in the common ancestor of Crustacea and Hexapoda.

  20. Elliptical Antenna Array Synthesis Using Backtracking Search Optimisation Algorithm

    Directory of Open Access Journals (Sweden)

    Kerim Guney

    2016-04-01

    Full Text Available The design of the elliptical antenna arrays is relatively new research area in the antenna array community. Backtracking search optimisation algorithm (BSA is employed for the synthesis of elliptical antenna arrays having different number of array elements. For this aim, BSA is used to calculate the optimum angular position and amplitude values of the array elements. BSA is a population-based iterative evolutionary algorithm. The remarkable properties of BSA are that it has a good optimisation performance, simple implementation structure, and few control parameters. The results of BSA are compared with those of self-adaptive differential evolution algorithm, firefly algorithm, biogeography based optimisation algorithm, and genetic algorithm. The results show that BSA can reach better solutions than the compared optimisation algorithms. Iterative performances of BSA are also compared with those of bacterial foraging algorithm and differential search algorithm.

  1. 2nd International Conference on Harmony Search Algorithm

    CERN Document Server

    Geem, Zong

    2016-01-01

    The Harmony Search Algorithm (HSA) is one of the most well-known techniques in the field of soft computing, an important paradigm in the science and engineering community.  This volume, the proceedings of the 2nd International Conference on Harmony Search Algorithm 2015 (ICHSA 2015), brings together contributions describing the latest developments in the field of soft computing with a special focus on HSA techniques. It includes coverage of new methods that have potentially immense application in various fields. Contributed articles cover aspects of the following topics related to the Harmony Search Algorithm: analytical studies; improved, hybrid and multi-objective variants; parameter tuning; and large-scale applications.  The book also contains papers discussing recent advances on the following topics: genetic algorithms; evolutionary strategies; the firefly algorithm and cuckoo search; particle swarm optimization and ant colony optimization; simulated annealing; and local search techniques.   This book ...

  2. Artificial Intelligence in Civil Engineering

    Directory of Open Access Journals (Sweden)

    Pengzhen Lu

    2012-01-01

    Full Text Available Artificial intelligence is a branch of computer science, involved in the research, design, and application of intelligent computer. Traditional methods for modeling and optimizing complex structure systems require huge amounts of computing resources, and artificial-intelligence-based solutions can often provide valuable alternatives for efficiently solving problems in the civil engineering. This paper summarizes recently developed methods and theories in the developing direction for applications of artificial intelligence in civil engineering, including evolutionary computation, neural networks, fuzzy systems, expert system, reasoning, classification, and learning, as well as others like chaos theory, cuckoo search, firefly algorithm, knowledge-based engineering, and simulated annealing. The main research trends are also pointed out in the end. The paper provides an overview of the advances of artificial intelligence applied in civil engineering.

  3. rAAV Vectors as Safe and Efficient Tools for the Stable Delivery of Genes to Primary Human Chondrosarcoma Cells In Vitro and In Situ

    Directory of Open Access Journals (Sweden)

    Henning Madry

    2012-01-01

    Full Text Available Treatment of chondrosarcoma remains a major challenge in orthopaedic oncology. Gene transfer strategies based on recombinant adenoassociated viral (rAAV vectors may provide powerful tools to develop new, efficient therapeutic options against these tumors. In the present study, we tested the hypothesis that rAAV is adapted for a stable and safe delivery of foreign sequences in human chondrosarcoma tissue by transducing primary human chondrosarcoma cells in vitro and in situ with different reporter genes (E. coli lacZ, firefly luc, Discosoma sp. RFP. The effects of rAAV administration upon cell survival and metabolic activities were also evaluated to monitor possibly detrimental effects of the gene transfer method. Remarkably, we provide evidence that efficient and prolonged expression of transgene sequences via rAAV can be safely achieved in all the systems investigated, demonstrating the potential of the approach of direct application of therapeutic gene vectors as a means to treat chondrosarcoma.

  4. A Modified Heuristic-Block Protocol Model for Privacy and Concurrency in Cloud

    Directory of Open Access Journals (Sweden)

    Akhilesh Kumar Bhardwaj

    2015-09-01

    Full Text Available With boost in the figure of cloud users and the magnitude of sensitive data on cloud, shielding of cloud has become more important. Competent methods are consistently desirable to ensure the information privacy and load management of outsource data on un-trusted cloud servers. The base of our proposed idea is the chronological display of metaheuristic firefly algorithm and blocks based Merkle hash tree protocol. This pool of combination significantly reduces the communication delay and I/O costs. The projected scheme in addition considers the dynamic data operations at block level while maintaining the equivalent security assurance. Our method makes use of third party auditor to periodically verify the data stored at cloud provider side. Our elucidation removes the burden of verification from the user side and alleviates both the user’s and storage service’s fear about data outburst and data corruptions.

  5. A Luciferase Functional Quantitative Assay for Measuring NF-ĸB Promoter Transactivation Mediated by HTLV-1 and HTLV-2 Tax Proteins.

    Science.gov (United States)

    Bergamo, Elisa; Diani, Erica; Bertazzoni, Umberto; Romanelli, Maria Grazia

    2017-01-01

    HTLV-1 and HTLV-2 viruses express Tax transactivator proteins required for viral genome transcription and capable of transforming cells in vivo and in vitro. Although Tax oncogenic potential needs to be further elucidated, it is well established that Tax proteins activate, among others, transcription factors of the NF-ĸB family, which are involved in immune and inflammatory responses, cell growth, apoptosis, stress responses and oncogenesis. Here, we describe a reporter gene assay applied for quantitative analysis of Tax-dependent NF-ĸB activation. The procedure is based on co-transfection of two individual vectors containing the cDNA for firefly and Renilla luciferase enzymes and vectors expressing Tax proteins. The luciferase expression is driven by cis-NF-ĸB promoter regulatory elements responsive to Tax transactivating factor. This assay is particularly useful to investigate Tax influence on NF-ĸB activation mediated by viral or host factors.

  6. Approaches to engineer stability of beetle luciferases

    Directory of Open Access Journals (Sweden)

    Mikhail Koksharov

    2012-09-01

    Full Text Available Luciferase enzymes from fireflies and other beetles have many important applications in molecular biology, biotechnology, analytical chemistry and several other areas. Many novel beetle luciferases with promising properties have been reported in the recent years. However, actual and potential applications of wild-type beetle luciferases are often limited by insufficient stability or decrease in activity of the enzyme at the conditions of a particular assay. Various examples of genetic engineering of the enhanced beetle luciferases have been reported that successfully solve or alleviate many of these limitations. This mini-review summarizes the recent advances in development of mutant luciferases with improved stability and activity characteristics. It discusses the common limitations of wild-type luciferases in different applications and presents the efficient approaches that can be used to address these problems.

  7. On the Effectiveness of Nature-Inspired Metaheuristic Algorithms for Performing Phase Equilibrium Thermodynamic Calculations

    Directory of Open Access Journals (Sweden)

    Seif-Eddeen K. Fateen

    2014-01-01

    Full Text Available The search for reliable and efficient global optimization algorithms for solving phase stability and phase equilibrium problems in applied thermodynamics is an ongoing area of research. In this study, we evaluated and compared the reliability and efficiency of eight selected nature-inspired metaheuristic algorithms for solving difficult phase stability and phase equilibrium problems. These algorithms are the cuckoo search (CS, intelligent firefly (IFA, bat (BA, artificial bee colony (ABC, MAKHA, a hybrid between monkey algorithm and krill herd algorithm, covariance matrix adaptation evolution strategy (CMAES, magnetic charged system search (MCSS, and bare bones particle swarm optimization (BBPSO. The results clearly showed that CS is the most reliable of all methods as it successfully solved all thermodynamic problems tested in this study. CS proved to be a promising nature-inspired optimization method to perform applied thermodynamic calculations for process design.

  8. Multiobjective Optimization of Irreversible Thermal Engine Using Mutable Smart Bee Algorithm

    Directory of Open Access Journals (Sweden)

    M. Gorji-Bandpy

    2012-01-01

    Full Text Available A new method called mutable smart bee (MSB algorithm proposed for cooperative optimizing of the maximum power output (MPO and minimum entropy generation (MEG of an Atkinson cycle as a multiobjective, multi-modal mechanical problem. This method utilizes mutable smart bee instead of classical bees. The results have been checked with some of the most common optimizing algorithms like Karaboga’s original artificial bee colony, bees algorithm (BA, improved particle swarm optimization (IPSO, Lukasik firefly algorithm (LFFA, and self-adaptive penalty function genetic algorithm (SAPF-GA. According to obtained results, it can be concluded that Mutable Smart Bee (MSB is capable to maintain its historical memory for the location and quality of food sources and also a little chance of mutation is considered for this bee. These features were found as strong elements for mining data in constraint areas and the results will prove this claim.

  9. Improved cell-free RNA and protein synthesis system.

    Directory of Open Access Journals (Sweden)

    Jun Li

    Full Text Available Cell-free RNA and protein synthesis (CFPS is becoming increasingly used for protein production as yields increase and costs decrease. Advances in reconstituted CFPS systems such as the Protein synthesis Using Recombinant Elements (PURE system offer new opportunities to tailor the reactions for specialized applications including in vitro protein evolution, protein microarrays, isotopic labeling, and incorporating unnatural amino acids. In this study, using firefly luciferase synthesis as a reporter system, we improved PURE system productivity up to 5 fold by adding or adjusting a variety of factors that affect transcription and translation, including Elongation factors (EF-Ts, EF-Tu, EF-G, and EF4, ribosome recycling factor (RRF, release factors (RF1, RF2, RF3, chaperones (GroEL/ES, BSA and tRNAs. The work provides a more efficient defined in vitro transcription and translation system and a deeper understanding of the factors that limit the whole system efficiency.

  10. Estrogen-Related Receptor alpha (ERR (alpha))-Coactivator Interactions as Targets for Discovery of New Anti-Breast Cancer Therapeutics

    Science.gov (United States)

    2007-03-01

    Lu c. A ct . ( re l. to T AT A- lu c) A. pTATA-Luc pERE(5x)-Luc pERRE (5x)-Luc - - - Figure 3. GRIP1 is a specific coactivator of “activated” ERRα...AGGTCACAGTGACCT-3’) upstream of the firefly luciferase reporter gene. pERRE (5x)-Luc contains five copies of the consensus estrogen-related receptor response...7 7- 42 3 ER R α 1 ER R α 1 7 7- 42 3 pTATA-Luc pERE(5x)-Luc pERRE (5x)-Luc Expression plasmid: Reporter: ER R α 1 ER R α 1 7 7- 42 3- - - B. 12

  11. Titration-based screening for evaluation of natural product extracts: identification of an aspulvinone family of luciferase inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, P.G.; Auld, D.S.; Schultz, P.J.; Lovell, S.; Battaile, K.P.; MacArthur, R.; Shen, M.; Tamayo-Castillo, G.; Inglese, J.; Sherman, D.H. (Michigan); (NIH); (Kansas); (Costa Rica); (HWMRI)

    2011-11-28

    The chemical diversity of nature has tremendous potential for the discovery of molecular probes and medicinal agents. However, sensitivity of HTS assays to interfering components of crude extracts derived from plants, and macro- and microorganisms has curtailed their use in lead discovery. Here, we describe a process for leveraging the concentration-response curves obtained from quantitative HTS to improve the initial selection of actives from a library of partially fractionated natural product extracts derived from marine actinomycetes and fungi. By using pharmacological activity, the first-pass CRC paradigm improves the probability that labor-intensive subsequent steps of reculturing, extraction, and bioassay-guided isolation of active component(s) target the most promising strains and growth conditions. We illustrate how this process identified a family of fungal metabolites as potent inhibitors of firefly luciferase, subsequently resolved in molecular detail by X-ray crystallography.

  12. A pharmacologist's journey in medical education:a personal history

    Institute of Scientific and Technical Information of China (English)

    E E DANIEL

    2004-01-01

    @@ My journey as an educator in Pharmacology began in 1949, when, after finishing my MA in Biology at Johns Hopkins, I decided that I wanted to be involved in science with more relevance to humans. I had been chasing fireflies around the parks of Baltimore and measuring luminescence in bacteria for my Master's work,but found it not very satisfying. I hoped that Pharmacology would provide a discipline with relevance to human welfare because of its role on study of drug actions and therapeutics and with many possibilities in basic science because of the need to know how drugs act and their availability to define physiology and pathophysiology by intervention in function. In retrospect,this hope has proved correct, at least from my viewpoint and that explains why I am still doing pharmacology teaching and research 54 years on.

  13. Short-fragment DNA-mediated in vivo DNA electroporation delivery.

    Science.gov (United States)

    Peng, Jinliang; Zhao, Yonggang; Xu, Yuhong

    2014-01-01

    Electroporation is an effective physical delivery method. A variety of factors have been shown to affect the electroporation-mediated gene delivery efficiency. Here we report the usefulness of noncoding short-fragment DNA (sf-DNA) for facilitating electroporation-mediated gene transfer. The plasmid pGL3-control encoding firefly luciferase was injected into tissue together with or without sf-DNA in different length or dose. Immediately after injection, the tissues were electroporated and the level of luciferase activity was assessed 24 h later. The results showed that plasmid DNA formulated with sf-DNA resulted in significant improvement in electroporation-mediated gene transfer efficiency. The effect is dose and length dependent, and also found in low-voltage electroporation. These results indicated that sf-DNA can be used as a helper molecule to improve the electroporation-mediated gene transfection efficiency.

  14. Wolf Pack Algorithm for Unconstrained Global Optimization

    Directory of Open Access Journals (Sweden)

    Hu-Sheng Wu

    2014-01-01

    Full Text Available The wolf pack unites and cooperates closely to hunt for the prey in the Tibetan Plateau, which shows wonderful skills and amazing strategies. Inspired by their prey hunting behaviors and distribution mode, we abstracted three intelligent behaviors, scouting, calling, and besieging, and two intelligent rules, winner-take-all generation rule of lead wolf and stronger-survive renewing rule of wolf pack. Then we proposed a new heuristic swarm intelligent method, named wolf pack algorithm (WPA. Experiments are conducted on a suit of benchmark functions with different characteristics, unimodal/multimodal, separable/nonseparable, and the impact of several distance measurements and parameters on WPA is discussed. What is more, the compared simulation experiments with other five typical intelligent algorithms, genetic algorithm, particle swarm optimization algorithm, artificial fish swarm algorithm, artificial bee colony algorithm, and firefly algorithm, show that WPA has better convergence and robustness, especially for high-dimensional functions.

  15. Quantitative bioluminescence imaging of mouse tumor models.

    Science.gov (United States)

    Tseng, Jen-Chieh; Kung, Andrew L

    2015-01-05

    Bioluminescence imaging (BLI) has become an essential technique for preclinical evaluation of anticancer therapeutics and provides sensitive and quantitative measurements of tumor burden in experimental cancer models. For light generation, a vector encoding firefly luciferase is introduced into human cancer cells that are grown as tumor xenografts in immunocompromised hosts, and the enzyme substrate luciferin is injected into the host. Alternatively, the reporter gene can be expressed in genetically engineered mouse models to determine the onset and progression of disease. In addition to expression of an ectopic luciferase enzyme, bioluminescence requires oxygen and ATP, thus only viable luciferase-expressing cells or tissues are capable of producing bioluminescence signals. Here, we summarize a BLI protocol that takes advantage of advances in hardware, especially the cooled charge-coupled device camera, to enable detection of bioluminescence in living animals with high sensitivity and a large dynamic range.

  16. A biocompatible, highly efficient click reaction and its applications.

    Science.gov (United States)

    Yuan, Yue; Liang, Gaolin

    2014-02-14

    Herein, we review the development, optimization, applications and potential prospects of a novel click reaction based on the condensation reaction between 2-cyanobenzothiazole (CBT) and D-cysteine (D-Cys) in fireflies. This click condensation reaction has obvious advantages in biocompatibility, efficiency and stability in aqueous environments. Optimization of this click reaction has been carried out so that it can be controlled by pH change, reduction, or enzymatic cleavage to synthesize large molecules and self-assembled nanostructures, or enhance probe signals. Consequently, this CBT-based click reaction has been and could be successfully applied to a wide range of biomedical applications such as molecular imaging (e.g., optical imaging, nuclear imaging and magnetic resonance imaging), biomolecular detection, drug delivery and other potentialities.

  17. Relative quantification of protein-protein interactions using a dual luciferase reporter pull-down assay system.

    Directory of Open Access Journals (Sweden)

    Shuaizheng Jia

    Full Text Available The identification and quantitative analysis of protein-protein interactions are essential to the functional characterization of proteins in the post-proteomics era. The methods currently available are generally time-consuming, technically complicated, insensitive and/or semi-quantitative. The lack of simple, sensitive approaches to precisely quantify protein-protein interactions still prevents our understanding of the functions of many proteins. Here, we develop a novel dual luciferase reporter pull-down assay by combining a biotinylated Firefly luciferase pull-down assay with a dual luciferase reporter assay. The biotinylated Firefly luciferase-tagged protein enables rapid and efficient isolation of a putative Renilla luciferase-tagged binding protein from a relatively small amount of sample. Both of these proteins can be quantitatively detected using the dual luciferase reporter assay system. Protein-protein interactions, including Fos-Jun located in the nucleus; MAVS-TRAF3 in cytoplasm; inducible IRF3 dimerization; viral protein-regulated interactions, such as MAVS-MAVS and MAVS-TRAF3; IRF3 dimerization; and protein interaction domain mapping, are studied using this novel assay system. Herein, we demonstrate that this dual luciferase reporter pull-down assay enables the quantification of the relative amounts of interacting proteins that bind to streptavidin-coupled beads for protein purification. This study provides a simple, rapid, sensitive, and efficient approach to identify and quantify relative protein-protein interactions. Importantly, the dual luciferase reporter pull-down method will facilitate the functional determination of proteins.

  18. Real-time Assessment of Streptococcus mutans Biofilm Metabolism on Resin Composite

    Science.gov (United States)

    Florez, Fernando Luis Esteban; Hiers, Rochelle Denise; Smart, Kristin; Kreth, Jens; Qi, Fengxia; Merritt, Justin; Khajotia, Sharukh Soli

    2016-01-01

    Objectives The release of unpolymerized monomers and by-products of resin composites influences biofilm growth and confounds the measurement of metabolic activity. Current assays to measure biofilm viability have critical limitations and are typically not performed on relevant substrates. The objective of the present study was to determine the utility of firefly luciferase assay for quantification of the viability of intact biofilms on a resin composite substrate, and correlate the results with a standard method (viable colony counts). Methods Disk-shaped specimens of a dental resin composite were fabricated, wet-polished, UV-sterilized, and stored in water. Biofilms of S. mutans (strain UA159 modified by insertion of constitutively expressed firefly luc gene) were grown (1:500 dilution; anaerobic conditions, 24h, 37°C) in two media concentrations (0.35x and 0.65x THY medium supplemented with 0.1% sucrose; n=15/group). An additional group of specimens with biofilms grown in 0.65x + sucrose media was treated with chlorhexidine gluconate solution to serve as the control group. Bioluminescence measurements of non-disrupted biofilms were obtained after addition of D-luciferin substrate. The adherent biofilms were removed by sonication, and bioluminescence of sonicated bacteria was then measured. Viable colony counts were performed after plating sonicated bacteria on THY agar plates supplemented with spectinomycin. Bioluminescence values and cell counts were correlated using Spearman Correlation tests (α=0.05). Results Strong positive correlations between viable colony counts and bioluminescence values, both before- and after-sonication, validated the utility of this assay. Significance A novel non-disruptive, real-time bioluminescence assay is presented for quantification of intact S. mutans biofilms grown on a resin composite, and potentially on antibacterial materials and other types of dental biomaterials. PMID:27515531

  19. Automatic generation control of multi-area power systems with diverse energy sources using Teaching Learning Based Optimization algorithm

    Directory of Open Access Journals (Sweden)

    Rabindra Kumar Sahu

    2016-03-01

    Full Text Available This paper presents the design and analysis of Proportional-Integral-Double Derivative (PIDD controller for Automatic Generation Control (AGC of multi-area power systems with diverse energy sources using Teaching Learning Based Optimization (TLBO algorithm. At first, a two-area reheat thermal power system with appropriate Generation Rate Constraint (GRC is considered. The design problem is formulated as an optimization problem and TLBO is employed to optimize the parameters of the PIDD controller. The superiority of the proposed TLBO based PIDD controller has been demonstrated by comparing the results with recently published optimization technique such as hybrid Firefly Algorithm and Pattern Search (hFA-PS, Firefly Algorithm (FA, Bacteria Foraging Optimization Algorithm (BFOA, Genetic Algorithm (GA and conventional Ziegler Nichols (ZN for the same interconnected power system. Also, the proposed approach has been extended to two-area power system with diverse sources of generation like thermal, hydro, wind and diesel units. The system model includes boiler dynamics, GRC and Governor Dead Band (GDB non-linearity. It is observed from simulation results that the performance of the proposed approach provides better dynamic responses by comparing the results with recently published in the literature. Further, the study is extended to a three unequal-area thermal power system with different controllers in each area and the results are compared with published FA optimized PID controller for the same system under study. Finally, sensitivity analysis is performed by varying the system parameters and operating load conditions in the range of ±25% from their nominal values to test the robustness.

  20. Noninvasive Imaging of Hypoxia-Inducible Factor-1α Gene Therapy for Myocardial Ischemia

    Science.gov (United States)

    Chen, Ian Y.; Gheysens, Olivier; Li, Zongjin; Rasooly, Julia A.; Wang, Qian; Paulmurugan, Ramasamy; Rosenberg, Jarrett; Rodriguez-Porcel, Martin; Willmann, Juergen K.; Wang, David S.; Contag, Christopher H.; Robbins, Robert C.; Wu, Joseph C.

    2013-01-01

    Abstract Hypoxia-inducible factor-1 alpha (HIF-1α) gene therapy holds great promise for the treatment of myocardial ischemia. Both preclinical and clinical evaluations of this therapy are underway and can benefit from a vector strategy that allows noninvasive assessment of HIF-1α expression as an objective measure of gene delivery. We have developed a novel bidirectional plasmid vector (pcTnT-HIF-1α-VP2-TSTA-fluc), which employs the cardiac troponin T (cTnT) promoter in conjunction with a two-step transcriptional amplification (TSTA) system to drive the linked expression of a recombinant HIF-1α gene (HIF-1α-VP2) and the firefly luciferase gene (fluc). The firefly luciferase (FLuc) activity serves as a surrogate for HIF-1α-VP2 expression, and can be noninvasively assessed in mice using bioluminescence imaging after vector delivery. Transfection of cultured HL-1 cardiomyocytes with pcTnT-HIF-1α-VP2-TSTA-fluc led to a strong correlation between FLuc and HIF-1α-dependent vascular endothelial growth factor expression (r2=0.88). Intramyocardial delivery of pcTnT-HIF-1α-VP2-TSTA-fluc into infarcted mouse myocardium led to persistent HIF-1α-VP2 expression for 4 weeks, even though it improved neither CD31+ microvessel density nor echocardiographically determined left ventricular systolic function. These results lend support to recent findings of suboptimal efficacy associated with plasmid-mediated HIF-1α therapy. The imaging techniques developed herein should be useful for further optimizing HIF-1α-VP2 therapy in preclinical models of myocardial ischemia. PMID:23937265

  1. QM/MM Structure, Enantioselectivity and Spectroscopy of HydroxyRetinals and Insights into the Evolution of Color Vision in Small White Butterflies

    Science.gov (United States)

    Sekharan, Sivakumar; Yokoyama, Shozo

    2011-01-01

    Since Vogt’s discovery of A3-retinal or 3-hydroxyretinal in insects in 1983 and Matsui’s discovery of A4-retinal or 4-hydroxyretinal in firefly squid in 1988, hydroxyretinal-protein interactions mediating vision remains largely unexplored. In the present study, A3- and A4-retinals are theoretically incorporated into squid and bovine visual pigments using the hybrid quantum mechanics/molecular mechanics (SORCI+Q//B3LYP/6-31G(d):Amber96) method and insights into the structure, enantioselectivity and spectroscopy are gathered and presented for the first time. Contrary to general perception, our findings rule out the formation of hydrogen bond between the hydroxyl-bearing β-ionone ring part of retinal and opsin. Compared to A1-pigments, A3- and A4-pigments exhibit slightly blue-shifted absorption maxima due to increase in bond-length alternation of the hydroxyretinal. We suggest that, (i) The binding site of firefly squid (Watasenia scintillians) opsin is very similar to that of the Japanese common squid (Todarodes pacificus) opsin, (ii) Molecular mechanism of spectral tuning in the small white butterflies involve sites S116, T185 and breaking of hydrogen bond between sites E180 and T185; and finally, (iii) A3-retinal may have occurred during the conversion of A1- to A2-retinal and insects may have acquired them, in order to absorb light in the blue-green wavelength region and to speed up the G-protein signaling cascade. PMID:22087641

  2. Specific expression of bioluminescence reporter gene in cardiomyocyte regulated by tissue specific promoter

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Vu Hong; Tae, Seong Ho; Le, Nguyen Uyen Chi; Min, Jung Joon [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-07-01

    As the human heart is not capable of regenerating the great numbers of cardiac cells that are lost after myocardial infarction, impaired cardiac function is the inevitable result of ischemic disease. Recently, human embryonic stem cells (hESCs) have gained popularity as a potentially ideal cell candidate for tissue regeneration. In particular, hESCs are capable of cardiac lineage-specific differentiation and confer improvement of cardiac function following transplantation into animal models. Although such data are encouraging, the specific strategy for in vivo and non-invasive detection of differentiated cardiac lineage is still limited. Therefore, in the present study, we established the gene construction in which the optical reporter gene Firefly luciferase was controlled by Myosin Heavy Chain promoter for specific expressing in heart cells. The vector consisting of - MHC promoter and a firefly luciferase coding sequence flanked by full-length bovine growth hormone (BGH) 3'-polyadenylation sequence based on pcDNA3.1- vector backbone. To test the specific transcription of this promoter in g of MHC-Fluc or CMV-Flue (for control) plasmid DNA in myocardial tissue, 20 phosphate-buffered saline was directly injected into mouse myocardium through a midline sternotomy and liver. After 1 week of injection, MHC-Fluc expression was detected from heart region which was observed under cooled CCD camera of in vivo imaging system but not from liver. In control group injected with CMV-Flue, the bioluminescence was detected from all these organs. The expression of Flue under control of Myosin Heavy Chain promoter may become a suitable optical reporter gene for stem cell-derived cardiac lineage differentiation study.

  3. Dual monitoring using {sup 124}I-FIAU and bioluminescence for HSV1-tk suicide gene therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T. S.; Kim, J. H.; Kwon, H. C. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)

    2007-07-01

    Herpes simplex virus type I thymidine kinase (HSV-tk) is the most common reporter gene and is used in cancer gene therapy with a prodrug nucleoside analog, ganciclovir (GCV). The aim of this study is to evaluate therapeutic efficacy of suicide gene therapy with 2'-fluoro-2'-deoxy-1-D-arabinofuranosyl-5-[{sup 124}I] iodouracil ({sup 124}I - FIAU) and bioluminescence in retrovirally HSV -tk and firefly luciferase transduced hepatoma model. The HSV -tk and firefly luciferase (Luc) was retrovirally transduced and expressed in MCA rat Morris hepatoma cells. Nude mice with subcutaneous tumors, MCA and MCA-TK-Luc, were subjected to GCV treatment (50mg/Kg/d intraperitoneally) for 5 day. PET imaging and biodistribution with ({sup 124}I-FIAU) were performed at before and after initiation of therapy with GCV. Bioluminescent signal was also measured during GCV treatment. Before GCV treatment, no significant difference in tumor volume was found in tumors between MCA and MCA-TK-Luc. After GCV treatment, tumor volume of MCA-TK-Luc markedly reduced compared to that of MCA. In biodistribution study, {sup 124}I-FIAU uptake after GCV therapy significantly decreased compared with pretreatment levels (34.8 13.67 %ID/g vs 7.6 2.59 %ID/g) and bioluminescent signal was also significantly decreased compared with pretreatment levels. In small animal PET imaging, {sup 124}I-FIAU selectively localized in HSV -tk expressing tumor and the therapeutic efficacy of GCV treatment was evaluated by {sup 124}I-FIAU PET imaging. {sup 124}I-FIAU PET and bioluminescence imaging in HSV-tk suicide gene therapy were effective to evaluate the therapeutic response. {sup 124}I-FIAU may serve as an efficient and selective agent for monitoring of transduced HSV1-tk gene expression in vivo in clinical trials.

  4. Non-invasive bioluminescence imaging to monitor the immunological control of a plasmablastic lymphoma-like B cell neoplasia after hematopoietic cell transplantation.

    Directory of Open Access Journals (Sweden)

    Martin Chopra

    Full Text Available To promote cancer research and to develop innovative therapies, refined pre-clinical mouse tumor models that mimic the actual disease in humans are of dire need. A number of neoplasms along the B cell lineage are commonly initiated by a translocation recombining c-myc with the immunoglobulin heavy-chain gene locus. The translocation is modeled in the C.129S1-Igha(tm1(MycJanz/J mouse which has been previously engineered to express c-myc under the control of the endogenous IgH promoter. This transgenic mouse exhibits B cell hyperplasia and develops diverse B cell tumors. We have isolated tumor cells from the spleen of a C.129S1-Igha(tm1(MycJanz/J mouse that spontaneously developed a plasmablastic lymphoma-like disease. These cells were cultured, transduced to express eGFP and firefly luciferase, and gave rise to a highly aggressive, transplantable B cell lymphoma cell line, termed IM380. This model bears several advantages over other models as it is genetically induced and mimics the translocation that is detectable in a number of human B cell lymphomas. The growth of the tumor cells, their dissemination, and response to treatment within immunocompetent hosts can be imaged non-invasively in vivo due to their expression of firefly luciferase. IM380 cells are radioresistant in vivo and mice with established tumors can be allogeneically transplanted to analyze graft-versus-tumor effects of transplanted T cells. Allogeneic hematopoietic stem cell transplantation of tumor-bearing mice results in prolonged survival. These traits make the IM380 model very valuable for the study of B cell lymphoma pathophysiology and for the development of innovative cancer therapies.

  5. Alternative translational initiation of ATP sulfurylase underlying dual localization of sulfate assimilation pathways in plastids and cytosol in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Anne-Sophie eBohrer

    2015-01-01

    Full Text Available Plants assimilate inorganic sulfate into sulfur-containing vital metabolites. ATP sulfurylase (ATPS is the enzyme catalyzing the key entry step of the sulfate assimilation pathway in both plastids and cytosol in plants. Arabidopsis thaliana has four ATPS genes (ATPS1, -2, -3 and -4 encoding ATPS pre-proteins containing N-terminal transit peptide sequences for plastid targeting, however, the genetic identity of the cytosolic ATPS has remained unverified. Here we show that Arabidopsis ATPS2 dually encodes plastidic and cytosolic ATPS isoforms, differentiating their subcellular localizations by initiating translation at AUGMet1 to produce plastid-targeted ATPS2 pre-proteins or at AUGMet52 or AUGMet58 within the transit peptide to have ATPS2 stay in cytosol. Translational initiation of ATPS2 at AUGMet52 or AUGMet58 was verified by expressing a tandem-fused synthetic gene, ATPS2(5’UTR-His12:Renilla luciferase:ATPS2(Ile13-Val77:firefly luciferase, under a single constitutively active CaMV 35S promoter in Arabidopsis protoplasts and examining the activities of two different luciferases translated in-frame with split N-terminal portions of ATPS2. Introducing missense mutations at AUGMet52 and AUGMet58 significantly reduced the firefly luciferase activity, while AUGMet52 was a relatively preferred site for the alternative translational initiation. The activity of luciferase fusion protein starting at AUGMet52 or AUGMet58 was not modulated by changes in sulfate conditions. The dual localizations of ATPS2 in plastids and cytosol were further evidenced by expression of ATPS2-GFP fusion proteins in Arabidopsis protoplasts and transgenic lines, while they were also under control of tissue-specific ATPS2 promoter activity found predominantly in leaf epidermal cells, guard cells, vascular tissues and roots.

  6. A quantitative and high-throughput assay of human papillomavirus DNA replication.

    Science.gov (United States)

    Gagnon, David; Fradet-Turcotte, Amélie; Archambault, Jacques

    2015-01-01

    Replication of the human papillomavirus (HPV) double-stranded DNA genome is accomplished by the two viral proteins E1 and E2 in concert with host DNA replication factors. HPV DNA replication is an established model of eukaryotic DNA replication and a potential target for antiviral therapy. Assays to measure the transient replication of HPV DNA in transfected cells have been developed, which rely on a plasmid carrying the viral origin of DNA replication (ori) together with expression vectors for E1 and E2. Replication of the ori-plasmid is typically measured by Southern blotting or PCR analysis of newly replicated DNA (i.e., DpnI digested DNA) several days post-transfection. Although extremely valuable, these assays have been difficult to perform in a high-throughput and quantitative manner. Here, we describe a modified version of the transient DNA replication assay that circumvents these limitations by incorporating a firefly luciferase expression cassette in cis of the ori. Replication of this ori-plasmid by E1 and E2 results in increased levels of firefly luciferase activity that can be accurately quantified and normalized to those of Renilla luciferase expressed from a control plasmid, thus obviating the need for DNA extraction, digestion, and analysis. We provide a detailed protocol for performing the HPV type 31 DNA replication assay in a 96-well plate format suitable for small-molecule screening and EC50 determinations. The quantitative and high-throughput nature of the assay should greatly facilitate the study of HPV DNA replication and the identification of inhibitors thereof.

  7. Investigating Performance of Various Natural Computing Algorithms

    Directory of Open Access Journals (Sweden)

    Bharat V. Chawda

    2017-01-01

    Full Text Available Nature is there since millenniums. Natural elements have withstood harsh complexities since years and have proved their efficiency in tackling them. This aspect has inspired many researchers to design algorithms based on phenomena in the natural world since the last couple of decades. Such algorithms are known as natural computing algorithms or nature inspired algorithms. These algorithms have established their ability to solve a large number of real-world complex problems by providing optimal solutions within the reasonable time duration. This paper presents an investigation by assessing the performance of some of the well-known natural computing algorithms with their variations. These algorithms include Genetic Algorithms, Ant Colony Optimization, River Formation Dynamics, Firefly Algorithm and Cuckoo Search. The Traveling Sales man Problem is used here as a test bed problem for performance evaluation of these algorithms. It is a kind of combinatorial optimization problem and known as one the most famous NP-Hard problems. It is simple and easy to understand, but at the same time, very difficult to find the optimal solution in a reasonable time – particularly with the increase in a number of cities. The source code for the above natural computing algorithms is developed in MATLAB R2015b and applied on several TSP instances given in TSPLIB library. Results obtained are analyzed based on various criteria such as tour length, required iterations, convergence time and quality of solutions. Conclusions derived from this analysis help to establish the superiority of Firefly Algorithms over the other algorithms in comparative terms.

  8. Mechanism of PTC124 activity in cell-based luciferase assays of nonsense codon suppression

    Science.gov (United States)

    Auld, Douglas S.; Thorne, Natasha; Maguire, William F.; Inglese, James

    2009-01-01

    High-throughput screening (HTS) assays used in drug discovery frequently use reporter enzymes such as firefly luciferase (FLuc) as indicators of target activity. An important caveat to consider, however, is that compounds can directly affect the reporter, leading to nonspecific but highly reproducible assay signal modulation. In rare cases, this activity appears counterintuitive; for example, some FLuc inhibitors, acting through posttranslational Fluc reporter stabilization, appear to activate gene expression. Previous efforts to characterize molecules that influence luciferase activity identified a subset of 3,5-diaryl-oxadiazole-containing compounds as FLuc inhibitors. Here, we evaluate a number of compounds with this structural motif for activity against FLuc. One such compound is PTC124 {3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid}, a molecule originally identified in a cell-based FLuc assay as having nonsense codon suppression activity [Welch EM, et al., Nature (2007) 447:87–91]. We find that the potency of FLuc inhibition for the tested compounds strictly correlates with their activity in a FLuc reporter cell-based nonsense codon assay, with PTC124 emerging as the most potent FLuc inhibitor (IC50 = 7 ± 1 nM). However, these compounds, including PTC124, fail to show nonsense codon suppression activity when Renilla reniformis luciferase (RLuc) is used as a reporter and are inactive against the RLuc enzyme. This suggests that the initial discovery of PTC124 may have been biased by its direct effect on the FLuc reporter, implicating firefly luciferase as a molecular target of PTC124. Our results demonstrate the value of understanding potential interactions between reporter enzymes and chemical compounds and emphasize the importance of implementing the appropriate control assays before interpreting HTS results. PMID:19208811

  9. Optimization of conditions for gene delivery system based on PEI

    Directory of Open Access Journals (Sweden)

    Roya Cheraghi

    2017-01-01

    Full Text Available Objective(s: PEI based nanoparticle (NP due to dual capabilities of proton sponge and DNA binding is known as powerful tool for nucleic acid delivery to cells. However, serious cytotoxicity and complicated conditions, which govern NPs properties and its interactions with cells practically, hindered achievement to high transfection efficiency. Here, we have tried to optimize the properties of PEI/ firefly luciferase plasmid complexes and cellular condition to improve transfection efficiency. Materials and Methods: For this purpose, firefly luciferase, as a robust gene reporter, was complexed with PEI to prepare NPs with different size and charge. The physicochemical properties of nanoparticles were evaluated using agarose gel retardation and dynamic light scattering.  MCF7 and BT474 cells at different confluency were also transfected with prepared nanoparticles at various concentrations for short and long times. Results: The branched PEI can instantaneously bind to DNA and form cationic NPs. The results demonstrated the production of nanoparticles with size about 100-500 nm dependent on N/P ratio. Moreover, increase of nanoparticles concentration on the cell surface drastically improved the transfection rate, so at a concentration of 30 ng/ìl, the highest transfection efficiency was achieved. On the other side, at confluency between 40-60%, the maximum efficiency was obtained. The result demonstrated that N/P ratio of 12 could establish an optimized ratio between transfection efficiency and cytotoxicity of PEI/plasmid nanoparticles. The increase of NPs N/P ratio led to significant cytotoxicity. Conclusion: Obtained results verified the optimum conditions for PEI based gene delivery in different cell lines.

  10. Introduction of optical reporter gene into cancer and immune cells using lentiviral vector

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung Joon; Le, Uyenchi N.; Moon, Sung Min; Heo, Young Jun; Song, Ho Chun; Bom, Hee Seung [School of Medicine, Chonnam National University, Gwangju (Korea, Republic of); Kim, Yeon Soo [Schoole of Medicine, Inje University, Seoul (Korea, Republic of)

    2004-07-01

    For some applications such as gene therapy or reporter gene imaging, a gene has to be introduced into the organism of interest. Adenoviral vectors are capable of transducing both replicating and non-dividing cells. The adenoviral vectors do not integrate their DNA into host DNA, but do lead to an immune response. Lentiviruses belong to the retrovirus family and are capable of infecting both dividing and non-dividing cells. The human immunodeficiency virus (HIV) is an example of a lentavirus. A disabled HIV virus has been developed and could be used for in vivo gene delivery. A portion of the viral genome which encodes for accessory proteins canbe deleted without affecting production of the vector and efficiency of infection. Lentiviral delivery into various rodent tissues shows sustained expression of the transgene of up to six months. Furthermore, there seems to be little or no immune response with these vectors. These lentiviral vectors hold significant promise for in vivo gene delivery. We constructed lentiviral vector encoding firefly luciferase (Fluc) and eGFP. Fluc-eGFP fusion gene was inserted into multiple cloning sites of pLentiM1.3 vector. Reporter gene (Fluc-eGFP) was designed to be driven by murine CMV promoter with enhanced efficacy of transgene expression as compared to human CMV promoter. We transfected pLenti1.3-Fluc into human cervix cancer cell line (HeLa) and murine T lymphocytes. We also constructed adenovirus encoding Fluc and transfected to HeLa and T cells. This LentiM1.3-Fluc was transfected into HeLa cells and murine T lymphocytes in vitro, showing consistent expression of eGFP under the fluorescence microscopy from the 2nd day of transfection. Firefly luciferase reporter gene was not expressed in immune cells when it is mediated by adenovirus. Lentivirus was validated as a useful vector for both immune and cancer cells.

  11. Tumor Irradiation Increases the Recruitment of Circulating Mesenchymal Stem Cells into the Tumor Microenvironment

    Science.gov (United States)

    Klopp, Ann H.; Spaeth, Erika L.; Dembinski, Jennifer L.; Woodward, Wendy A.; Munshi, Anupama; Meyn, Raymond E.; Cox, James D.; Andreeff, Michael; Marini, Frank C.

    2011-01-01

    Mesenchymal stem cells (MSC) migrate to and proliferate within sites of inflammation and tumors as part of the tissue remodeling process. Radiation increases the expression of inflammatory mediators that could enhance the recruitment of MSC into the tumor microenvironment. To investigate this, bilateral murine 4T1 breast carcinomas (expressing renilla luciferase) were irradiated unilaterally (1 or 2 Gy). Twenty-four hours later, 2 × 105 MSC-expressing firefly luciferase were injected i.v. Mice were then monitored with bioluminescent imaging for expression of both renilla (tumor) and firefly (MSC) luciferase. Forty-eight hours postirradiation, levels of MSC engraftment were 34% higher in tumors receiving 2 Gy (P = 0.004) than in the contralateral unirradiated limb. Immunohistochemical staining of tumor sections from mice treated unilaterally with 2 Gy revealed higher levels of MSC in the parenchyma of radiated tumors, whereas a higher proportion of MSC remained vasculature-associated in unirradiated tumors. To discern the potential mediators involved in MSC attraction, in vitro migration assays showed a 50% to 80% increase in MSC migration towards conditioned media from 1 to 5 Gy-irradiated 4T1 cells compared with unirradiated 4T1 cells. Irradiated 4T1 cells had increased expression of the cytokines, transforming growth factor-β1, vascular endothelial growth factor, and platelet-derived growth factor-BB, and this up-regulation was confirmed by immunohistochemistry in tumors irradiated in vivo. Interestingly, the chemokine receptor CCR2 was found to be up-regulated in MSC exposed to irradiated tumor cells and inhibition of CCR2 led to a marked decrease of MSC migration in vitro. In conclusion, clinically relevant low doses of irradiation increase the tropism for and engraftment of MSC in the tumor microenvironment. PMID:18089798

  12. Expression of sarcomeric tropomyosin in striated muscles in axolotl treated with shz-1, a small cardiogenic molecule.

    Science.gov (United States)

    Nan, Changlong; Dube, Syamalima; Matoq, Amr; Mikesell, Lauren; Abbott, Lynn; Alshiekh-Nasany, Ruham; Chionuma, Henry; Huang, Xupei; Poiesz, Bernard J; Dube, Dipak K

    2015-01-01

    We evaluated the effect of shz-1, a cardiogenic molecule, on the expression of various tropomyosin (TM) isoforms in the Mexican axolotl (Ambystoma mexicanum) hearts. qRT-PCR data show a ~1.5-fold increase in cardiac transcripts of the Nkx2.5 gene, which plays a crucial role in cardiogenesis in vertebrates. Shz-1 augments the expression of transcripts of the total sarcomeric TPM1 (both TPM1α & TPM1κ) and sarcomeric TPM4α. In order to understand the mechanism by which shz-1 augments the expression of sarcomeric TPM transcription in axolotl hearts, we transfected C2C12 cells with pGL3.axolotl. We transfected C2C12 cells with pGL3-axolotl TPM4 promoter constructs containing the firefly luciferase reporter gene. The transfected C2C12 cells were grown in the absence or presence of shz-1 (5 μM). Subsequently, we determined the firefly luciferase activity in the extracts of transfected cells. The results suggest that shz-1 activates the axolotl TPM4 promoter-driven ectopic expression in C2C12 cells. Also, we transfected C2C12 cells with a pGL3.1 vector containing the promoter of the mouse skeletal muscle troponin-I and observed a similar increase in the luciferase activity in shz-1-treated cells. We conclude that shz-1 activates the promoters of a variety of genes including axolotl TPM4. We have quantified the expression of the total sarcomeric TPM1 and observed a 1.5-fold increase in treated cells. Western blot analyses with CH1 monoclonal antibody specific for sarcomeric isoforms show that shz-1 does not increase the expression of TM protein in axolotl hearts, whereas it does in C2C12 cells. These findings support our hypothesis that cardiac TM expression in axolotl undergoes translational control.

  13. Enhancement of allele discrimination by introduction of nucleotide mismatches into siRNA in allele-specific gene silencing by RNAi.

    Directory of Open Access Journals (Sweden)

    Yusuke Ohnishi

    Full Text Available Allele-specific gene silencing by RNA interference (RNAi is therapeutically useful for specifically inhibiting the expression of disease-associated alleles without suppressing the expression of corresponding wild-type alleles. To realize such allele-specific RNAi (ASP-RNAi, the design and assessment of small interfering RNA (siRNA duplexes conferring ASP-RNAi is vital; however, it is also difficult. In a previous study, we developed an assay system to assess ASP-RNAi with mutant and wild-type reporter alleles encoding the Photinus and Renilla luciferase genes. In line with experiments using the system, we realized that it is necessary and important to enhance allele discrimination between mutant and corresponding wild-type alleles. Here, we describe the improvement of ASP-RNAi against mutant alleles carrying single nucleotide variations by introducing base substitutions into siRNA sequences, where original variations are present in the central position. Artificially mismatched siRNAs or short-hairpin RNAs (shRNAs against mutant alleles of the human Prion Protein (PRNP gene, which appear to be associated with susceptibility to prion diseases, were examined using this assessment system. The data indicates that introduction of a one-base mismatch into the siRNAs and shRNAs was able to enhance discrimination between the mutant and wild-type alleles. Interestingly, the introduced mismatches that conferred marked improvement in ASP-RNAi, appeared to be largely present in the guide siRNA elements, corresponding to the 'seed region' of microRNAs. Due to the essential role of the 'seed region' of microRNAs in their association with target RNAs, it is conceivable that disruption of the base-pairing interactions in the corresponding seed region, as well as the central position (involved in cleavage of target RNAs, of guide siRNA elements could influence allele discrimination. In addition, we also suggest that nucleotide mismatches at the 3'-ends of sense

  14. Construction and Properties of a Microbial Whole-cell Sensor CB10 for the Bioavailability Detection of Cr6+%Cr6+生物可利用度检测的微生物全细胞传感器CB10的构建及其响应特征

    Institute of Scientific and Technical Information of China (English)

    侯启会; 马安周; 庄绪亮; 庄国强

    2013-01-01

    为实现重金属污染环境中 Cr6-的生物可利用度评价,进而为Cr6的污染治理提供可靠依据,本研究采用分子生物技术,以重金属广谱抗性菌株Cupriavidus metallidurans CH34的pMOL28质粒上铬抗性调控系统的启动子和调控蛋白基因为传感器调控元件,以北美萤火虫Photinus pyralis的萤火虫荧光素酶基因luc为报告基因构建了一种可对Cr6+生物可利用度进行检测的微生物全细胞传感器CB10,并探究了其在不同检测条下的响应特征.结果表明,微生物全细胞传感器CB10在30 min内即可响应一定浓度的Cr6+;其对Cr6的检测最低限LOD为2μmol· L-1;当Cr6的浓度为20 ~ 200 μmol·L-1时,CB10的响应能力与Cr6+浓度线性相关,进而传感器CB10可对该范围内的Cr6+生物可利用度进行定量分析(R2=0.980 55);当重金属诱导浓度为10~ 50 μmol·L-1时,CB10对Cr6+具有较强的响应特异性;本研究也发现,较高浓度的pb2+、Mn2+和Sb2+也可以产生对CB10的诱导能力;诱导温度为30℃,pH为7时,CB10的响应效率最高;诱导温度为15 ~ 30℃,pH为4~7时,CB10响应能力表现稳定.CB10具备较强的响应速率、灵敏度、特异性和稳定性,具备对水体重金属进行快速检测和土壤重金属的生物可利用进行评价的潜力.%A microbial whole-cell biosensor CB10 for the bioavailability assessing of Cr6+ was constructed by molecular biotechnology. The regulatory gene and promoter of CB10 was from the chromium resistance system of plasmid pMOL28 from Cupriavidus metallidurans CH34, and the reporter gene of CB10 was luc which was derived from Photinus pyralis. Finally, its response characteristic was discussed under different incubation conditions e. g. pH and temperature. The results showed that a microbial whole-cell biosensor CB10 had been successfully constructed which could respond to Cr6+ within 30 min , with a LOD for Cr6+ of 2 μmol·L-1. When the incubation concentration of

  15. Long term expression of bicistronic vector driven by the FGF-1 IRES in mouse muscle

    Directory of Open Access Journals (Sweden)

    Van den Berghe Loïc

    2007-10-01

    Full Text Available Abstract Background Electrotransfer of plasmid DNA into skeletal muscle is a promising strategy for the delivery of therapeutic molecules targeting various muscular diseases, cancer and lower-limb ischemia. Internal Ribosome Entry Sites (IRESs allow co-expression of proteins of interest from a single transcriptional unit. IRESs are RNA elements that have been found in viral RNAs as well as a variety of cellular mRNAs with long 5' untranslated regions. While the encephalomyocarditis virus (EMCV IRES is often used in expression vectors, we have shown that the FGF-1 IRES is equally active to drive short term transgene expression in mouse muscle. To compare the ability of the FGF-1 IRES to drive long term expression against the EMCV and FGF-2 IRESs, we performed analyses of expression kinetics using bicistronic vectors that express the bioluminescent renilla and firefly luciferase reporter genes. Long term expression of bicistronic vectors was also compared to that of monocistronic vectors. Bioluminescence was quantified ex vivo using a luminometer and in vivo using a CCD camera that monitors luminescence within live animals. Results Our data demonstrate that the efficiency of the FGF-1 IRES is comparable to that of the EMCV IRES for long term expression of bicistronic transgenes in mouse muscle, whereas the FGF-2 IRES has a very poor activity. Interestingly, we show that despite the global decrease of vector expression over time, the ratio of firefly to renilla luciferase remains stable with bicistronic vectors containing the FGF-1 or FGF-2 IRES and is slightly affected with the EMCV IRES, whereas it is clearly unstable for mixed monocistronic vectors. In addition, long term expression more drastically decreases with monocistronic vectors, and is different for single or mixed vector injection. Conclusion These data validate the use of bicistronic vectors rather than mixed monocistronic vectors for long term expression, and support the use of the

  16. 基于多群体改进萤火虫算法的UCAV协同多目标分配%Target Assignment in Cooperative Attacking of UCAVs Based on Multi-Intelligence Improved Glowworm Swarm Optimization Algorithm

    Institute of Scientific and Technical Information of China (English)

    王永泉; 罗建军

    2014-01-01

    对多UCAV协同攻击目标分配问题进行了研究。以收益指标、消耗指标及航程指标为准则建立数学模型,采用改进的萤火虫优化算法对模型进行求解;对基本萤火虫优化算法进行了改进,给出了新的萤火虫更新策略,引入了局部搜索及全局信息交换机制,并将萤火虫优化算法与混合蛙跳算法融合,实现了多智能群体共同进化,提出了一种基于多群体改进萤火虫优化算法的UCAV目标分配算法;针对UCAV协同攻击决策特点,设计了萤火虫离散编码方式,最终得到多UCAV协同攻击最优分配方案。仿真结果表明,多群体萤火虫优化算法能够稳定快速地给出目标分配最优方案。%A target allocation algorithm based on multi-intelligence improved glowworm swarm optimization ( MIG-SO) algorithm is proposed. A model of decision-making is built up by taking benefit index, loss index and range in-dex as the criteria, and the MIGSO is used to solve the model. Finally the optimal allocation scheme for multi-air-craft cooperative attacking is gotten. According to the characteristics of UCAV attack decision making, a special coding for firefly particle and firefly update strategy is presented. With shuffled frog leaping algorithm (SFLA), glowworms are divided into different ethnic groups, and local search and global information exchange method im-proves GSO performance. SFLA is also combined with GSO, which realize the co-evolution of the two kinds of groups. The simulation results shows that the MIGSO algorithm can give the optimal target assignment solution quickly and effectively.

  17. 求解WSNs覆盖优化的改进萤火虫优化算法%Improved glowworm swarm optimization algorithm for coverage optimization of wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    许江涛

    2013-01-01

    In order to improve the coverage quality of wireless sensor networks,reduce energy consumption and prolong the survival period, a coverage optimization algorithm based on improved glowworm swarm optimization (IGSO) algorithm is presented. This paper uses the IGSO to solve the model of coverage optimization in WSN which is built up by taking node balance and network coverage rate as the criterions and the optimal coverage solution in WSN is realized. Based on the problems of the traditional GSC,such as low convergence efficiency,the firefly population division thought is introduced, which increases the diversity of population. The chaos optimization technique is used to improve the quality of initial solutions group for the firefly population initialization. The simulation results show that,the IGSO can effectively give the network coverage optimization scheme,and improve network energy consumption and survival time.%为了提高无线传感器网络覆盖质量,降低能量消耗和延长生存周期,提出了一种基于改进萤火虫优化算法的网络覆盖算法.算法以网络覆盖率及节点均衡性为指标建立网络覆盖数学模型,采用改进的萤火虫算法对模型进行求解,从而得到无线传感器网络节点的最优化部署.针对传统萤火虫算法收敛效率低的缺陷,引入萤火虫群体族群划分思想,增加了群体多样性;利用混沌优化技术,对萤火虫群体初始化,提高了群体初始解质量.仿真结果表明,改进的萤火虫算法快速有效的给出了网络覆盖最优方案,并明显改善了网络能量消耗及生存时间.

  18. Power Allocation for Multi-relay Cooperative Systems Based on Glowworm Swarm Optimization Algorithm%基于萤火虫算法的多中继功率分配

    Institute of Scientific and Technical Information of China (English)

    唐思腾; 刘紫燕; 帅暘

    2014-01-01

    To fully realize the potentials of relay-assisted transmission and reduce the computational com-plexity of power allocation for multi-relay cooperative communication systems,a power allocation scheme based on glowworm swarm optimization( GSO) algorithm is proposed. With a total transmiting power and per-node transmitting power constraints,the power allocation optimization model is presented to maximize the average signal-to-noise ratio( SNR) . The objective function is selected as fitness function of GSO,sta-tus of fireflies is measured by a vector,of which each element represents power of source node and the relay node,respectively. Most fireflies in the GSO gather at the location where the fitness function value is the best,i. e. asymptotically optimal power allocation scheme is obtained. Simulation and numerical results demonstrate that power allocation scheme based on GSO achieves better performance with lower bit error rate up to 2. 44% ~6. 17% compared with equal power allocation(EPA).%为了充分实现中继协作,降低多中继协作通信系统功率分配优化问题的计算复杂度,提出了基于萤火虫算法的多中继功率分配方案。在一定的总功率和节点功率约束下,以最大化平均信噪比为优化目标函数,建立了多中继协作系统的功率分配最优化模型。选取该目标函数作为萤火虫的适应度函数,用向量表示萤火虫的状态,该向量的维数为待分配源节点和中继节点的个数,通过萤火虫聚集得到种群中最好的萤火虫,即可获得渐进最优功率分配。仿真结果表明,与平均功率分配相比,基于萤火虫算法的功率分配方案能降低2.44%~6.17%的比特差错率,提高了系统性能。

  19. 物联网感知层多Sink节点关联算法研究%Research on Multi-Sink Node Association Algorithm of Internet of Things Perception Layer

    Institute of Scientific and Technical Information of China (English)

    王华东; 王大羽

    2015-01-01

    针对大规模无线传感器网络采用单一的Sink节点容易造成网络"能量空洞"效应,而多Sink节点数量和位置的合理部署能有效延长无线传感器网络寿命、控制网络成本,同时多Sink节点数量和位置是一个NP--难问题,因此提出新颖的萤火虫算法对多Sink节点布局模型问题进行求解计算,并对算法的计算精度、效率进行了分析.通过理论分析和仿真验证表明,结果表明文中提出基于萤火虫算法的多Sink节点布局模型与随机分布,基于遗传算法、蚁群算法的多Sink节点部署算法相比,能够有效降低无线传感器网络的能量消耗,减少端到端网络延时,降低网络部署成本,提高网络服务效率,延长网络的生存期.%In large-scale wireless sensor networks monitoring environment,using a single Sink node in the network is likely to cause "energy hole" effect ,while Sink node number and location of proper deployment can cost effectively extend the lifetime of wireless sensor networks,control network costs,at the same time multi-Sink node number and location is an NP - hard problem.Therefore propose the firefly algorithm to solve the problems of the multiple Sink node layout model calculation,and analyses the calculation accuracy and efficiency of algorithm.Theoretical analysis and simulation results show that the proposed in this paper based on the firefly algorithm Sink node layout model with random distribution,based on genetic algorithm,ant colony algorithm Sink node deployment algorithm,can effectively reduce the energy consumption of wireless sensor networks,reducing end-to-end network delay,reduce network deployment costs,improve network efficiency and prolong the lifetime of the network.

  20. Genetic manipulation of Schistosoma haematobium, the neglected schistosome.

    Directory of Open Access Journals (Sweden)

    Gabriel Rinaldi

    2011-10-01

    Full Text Available BACKGROUND: Minimal information on the genome and proteome of Schistosoma haematobium is available, in marked contrast to the situation with the other major species of human schistosomes for which draft genome sequences have been reported. Accordingly, little is known about functional genomics in S. haematobium, including the utility or not of RNA interference techniques that, if available, promise to guide development of new interventions for schistosomiasis haematobia. METHODS/FINDINGS: Here we isolated and cultured developmental stages of S. haematobium, derived from experimentally infected hamsters. Targeting different developmental stages, we investigated the utility of soaking and/or square wave electroporation in order to transfect S. haematobium with nucleic acid reporters including Cy3-labeled small RNAs, messenger RNA encoding firefly luciferase, and short interfering RNAs (siRNAs. Three hours after incubation of S. haematobium eggs in 50 ng/µl Cy3-labeled siRNA, fluorescent foci were evident indicating that labeled siRNA had penetrated into miracidia developing within the egg shell. Firefly luciferase activity was detected three hours after square wave electroporation of the schistosome eggs and adult worms in 150 ng/µl of mRNA. RNA interference knockdown (silencing of reporter luciferase activity was seen following the introduction of dsRNA specific for luciferase mRNA in eggs, schistosomules and mixed sex adults. Moreover, introduction of an endogenous gene-specific siRNA into adult schistosomes silenced transcription of tetraspanin 2 (Sh-tsp-2, the apparent orthologue of the Schistosoma mansoni gene Sm-tsp-2 which encodes the surface localized structural and signaling protein Sm-TSP-2. Together, knockdown of reporter luciferase and Sh-tsp-2 indicated the presence of an intact RNAi pathway in S. haematobium. Also, we employed laser scanning confocal microscopy to view the adult stages of S. haematobium. CONCLUSIONS: These findings

  1. Integration of Environmental Sensors with BIM: case studies using Arduino, Dynamo, and the Revit API

    Directory of Open Access Journals (Sweden)

    Kensek, K. M.

    2014-12-01

    Full Text Available This paper investigates the feasibility of connecting environmental sensors such as light, humidity, or CO2 receptors to a building information model (BIM. A base case was created in Rhino; using Grasshopper and Firefly, a simple digital model responded to lighting-levels detected by a photoresistor on an Arduino board. The case study was duplicated using Revit Architecture, a popular BIM software, and Dynamo, a visual programming environment, in an innovative application. Another case study followed a similar procedure by implementing the Revit API directly instead of using Dynamo. Then the process was reversed to demonstrate that not only could data could be sent from sensors to change the 3D model, but changes to parameters of a 3D model could effect a physical model through the use of actuators. It is intended that these virtual/physical prototypes could be used as the basis for testing intelligent façade systems before constructing full size mock-ups.Este estudio investiga la posibilidad de conectar sensores ambientales como de luz, humedad, o dióxido de carbono con un modelo de información de un edificio (siglas BIM en inglés. Un caso base fue creado en Rhino; usando Grasshopper and Firefly, donde un simple modelo digital respondió a niveles de luz detectados por un foto resistor en una tarjeta Arduino. El caso de estudio fue duplicado usando Revit Architecture, una herramienta popular en BIM, y Dynamo, un ambiente de programación gráfica, en una creativa aplicación. Un segundo caso de estudio siguió un procedimiento similar implementando Revit API directamente en vez de usar Dynamo. Entonces el proceso fue revertido para demostrar que no solamente la información podría ser enviada desde sensores para cambiar el modelo tridimensional, pero cambios en los parámetros de un modelo tridimensional podrían afectar un modelo físico mediante el uso de actuadores. Se espera que esos modelos virtuales puedan ser usados como base para

  2. Construction and identification of helper plasmids of newcastle disease virus Italien strain

    Directory of Open Access Journals (Sweden)

    Zhen REN

    2012-07-01

    Full Text Available Objective Newcastle disease virus (NDV is a naturally oncolytic virus that has been shown to be safe and effective for cancer therapy. NDV virions possess a non-segmented negative-sense single-stranded RNA genome which contains six genes encoding the nucleocapsid protein (NP, phosphoprotein (P, large polymerase protein (L, matrix protein, fusion protein, and hemagglutinin-neuraminidase. The ribonucleoprotein (RNP complex consisting of the genomic RNA and the three proteins NP, P, and L are the active template for transcription and replication of the viral genome. The purpose of this study was to construct the expression plasmids of NP, P and L genes of NDV Italien strain in which phage T7 promoter was a transcription promoter for the aim of generation of recombinant NDV. Methods NP, P and L genes were cloned from the genome RNA of NDV Italien followed by introduction into the downstream of T7 promoter and internal ribosome entry sites to construct the expression plasmids of NP, P and L, respectively. Expression of exogenous gene in BSR-T7/5 cells which constitutively express phage T7 RNA polymerase and transfected with plasmids of NP and P was detected by indirect immunofluorescence assay. The function of NP, P and L proteins expressed by constructed plasmids to facilitate the genomic RNA to form RNP complex was tested using minigenome of NDV Italien carrying firefly luciferase as a reporter gene. Results The expression plasmids of NP, P and L genes were confirmed by DNA sequencing. Using the indirect immunofluorescence assay, we detected the expression of viral NP and P proteins in BSR-T7/5 cells. When the helper plasmids were co-transfected with NDV minigenome plasmid, the expression of firefly luciferase was more significant compared with the control group (P < 0.001. Conclusion The helper plasmids of NDV Italien strain using T7 promoter as a transcription promoter has been constructed successfully, and it provides a basis for the

  3. Development and characterization of a green fluorescent protein-based rat cell bioassay system for detection of AH receptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Bin; Denison, M. [California Univ., Davis, CA (United States). Dept. of Environmental Toxicology

    2004-09-15

    Proper epidemiological, risk assessment and exposure analysis of TCDD and related HAHs requires accurate measurements of these chemicals both in the species of interest and in various exposure matrices (i.e. biological, environmental, food and feed). While high-resolution instrumental analysis techniques are established for these chemicals, these procedures are very costly, time-consuming and are impractical for large scale sampling studies. Accordingly, numerous bioanalytical methods have been developed for the detection of these chemicals in extracts from a variety of matrices, the majority of which take the advantage of the ability of these chemicals to activate one or more aspects of the AhR-dependent mechanism of action. One of the most sensitive bioassay systems developed to date is the so-called CALUX (Chemically Activated Luciferase Expression) assay, which is based on novel recombinant cell lines that contain a stably transfected dioxin (AhR)-responsive firefly luciferase gene. Treatment of these cells with TCDD and related HAHs and polycyclic aromatic hydrocarbons (PAHs), as well as other AhR ligands, results in induction of reporter gene expression in a time-, dose-, AhR-, and chemical-specific manner. The level of reporter gene expression correlates with the total concentration of the TCDD-like AhR inducers (agonists) present in the sample. Although the firefly luciferase reporter gene contributes to the high degree of sensitivity of the assay, it also has limitations with respect to our need for a rapid and inexpensive bioassay for high-throughput screening analysis. Accordingly, we previously developed a stably transfected murine cell line containing an AhRresponsive enhanced green fluorescent protein (EGFP) reporter gene. This cell line provided us with a high-throughput cell bioassay system for identification and characterization of AhR agonists and antagonists. Here we have extended these studies and describe the development, optimization, and

  4. Short-term wind speed forecasting based on WD-CFA-LSSVM model%基于小波变换和改进萤火虫算法优化LSSVM的短期风速预测

    Institute of Scientific and Technical Information of China (English)

    方必武; 刘涤尘; 王波; 闫秉科; 汪勋婷

    2016-01-01

    准确预测风速对风电规模化并网至关重要。为提高短期风速预测精度,提出一种基于小波分解和改进的萤火虫算法优化最小二乘支持向量机超参数的风速预测模型。首先利用小波变换将风速时序分解为近似序列和细节序列,然后对各序列分别利用一种新颖的混沌萤火虫算法优化LSSVM进行预测,最后将各序列预测值叠加得到最终风速预测值。在两种时间尺度的实测数据上进行仿真计算。结果表明,该算法较交叉验证的 LSSVM, IPSO-LSSVM, WD-DE-LSSVM及BP神经网络等多种经典算法预测精度更高,表明了该算法的有效性和优越性。%Accurately predicting wind speed is of key importance for large scale wind power connecting to the grid. To improve the short-term wind speed forecasting accuracy, a least squares support vector machine wind speed prediction model based on wavelet decomposition and improved firefly algorithm is proposed. Firstly, the actual wind speed series is decomposed and reconstructed to approximate series and detail series, then the series are separately predicted by LSSVM optimized by chaotic firefly algorithm, at last the separate prediction series are superposed as the ultimate prediction wind speed. To verify the proposed model, two different time scale actual wind speed data are applied to simulation. The results show that the proposed model has higher prediction accuracy than classical model like CV-LSSVM, IPSO-LSSVM, WD-DE-LSSVM and BP neural networks, showing its validity and superiority.

  5. A Saccharomyces cerevisiae assay system to investigate ligand/AdipoR1 interactions that lead to cellular signaling.

    Directory of Open Access Journals (Sweden)

    Mustapha Aouida

    Full Text Available Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p. The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA signaling and AMP activated protein kinase (AMPK phosphorylation in S. cerevisiae, which are

  6. A Saccharomyces cerevisiae Assay System to Investigate Ligand/AdipoR1 Interactions That Lead to Cellular Signaling

    KAUST Repository

    Aouida, Mustapha

    2013-06-07

    Adiponectin is a mammalian hormone that exerts anti-diabetic, anti-cancer and cardioprotective effects through interaction with its major ubiquitously expressed plasma membrane localized receptors, AdipoR1 and AdipoR2. Here, we report a Saccharomyces cerevisiae based method for investigating agonist-AdipoR interactions that is amenable for high-throughput scale-up and can be used to study both AdipoRs separately. Agonist-AdipoR1 interactions are detected using a split firefly luciferase assay based on reconstitution of firefly luciferase (Luc) activity due to juxtaposition of its N- and C-terminal fragments, NLuc and CLuc, by ligand induced interaction of the chimeric proteins CLuc-AdipoR1 and APPL1-NLuc (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif 1-NLuc) in a S. cerevisiae strain lacking the yeast homolog of AdipoRs (Izh2p). The assay monitors the earliest known step in the adiponectin-AdipoR anti-diabetic signaling cascade. We demonstrate that reconstituted Luc activity can be detected in colonies or cells using a CCD camera and quantified in cell suspensions using a microplate reader. AdipoR1-APPL1 interaction occurs in absence of ligand but can be stimulated specifically by agonists such as adiponectin and the tobacco protein osmotin that was shown to have AdipoR-dependent adiponectin-like biological activity in mammalian cells. To further validate this assay, we have modeled the three dimensional structures of receptor-ligand complexes of membrane-embedded AdipoR1 with cyclic peptides derived from osmotin or osmotin-like plant proteins. We demonstrate that the calculated AdipoR1-peptide binding energies correlate with the peptides\\' ability to behave as AdipoR1 agonists in the split luciferase assay. Further, we demonstrate agonist-AdipoR dependent activation of protein kinase A (PKA) signaling and AMP activated protein kinase (AMPK) phosphorylation in S. cerevisiae, which are homologous to

  7. Sodium Iodide Symporter PET and BLI Noninvasively Reveal Mesoangioblast Survival in Dystrophic Mice

    Directory of Open Access Journals (Sweden)

    Bryan Holvoet

    2015-12-01

    Full Text Available Muscular dystrophies are a heterogeneous group of myopathies, characterized by muscle weakness and degeneration, without curative treatment. Mesoangioblasts (MABs have been proposed as a potential regenerative therapy. To improve our understanding of the in vivo behavior of MABs and the effect of different immunosuppressive therapies, like cyclosporine A or co-stimulation-adhesion blockade therapy, on cell survival noninvasive cell monitoring is required. Therefore, cells were transduced with a lentiviral vector encoding firefly luciferase (Fluc and the human sodium iodide transporter (hNIS to allow cell monitoring via bioluminescence imaging (BLI and small-animal positron emission tomography (PET. Non-H2 matched mMABs were injected in the femoral artery of dystrophic mice and were clearly visible via small-animal PET and BLI. Based on noninvasive imaging data, we were able to show that co-stim was clearly superior to CsA in reducing cell rejection and this was mediated via a reduction in cytotoxic T cells and upregulation of regulatory T cells.

  8. An Improved Glowworm Swarm Optimization Algorithm with Changing Step%一种改进的变步长的萤火虫算法

    Institute of Scientific and Technical Information of China (English)

    李恒; 郭星; 李炜

    2016-01-01

    为了克服人工萤火虫算法(Glowworm swarm optimization,GSO)在求解全局优化问题时,存在收敛速度慢,求解精度不高、易陷入局部最优等问题。提出了一种改进的变步长自适应的萤火虫优化算法。采用该算法可在一定程度上避免因过早的成熟陷入局部最优,并且可在后期达到更高的精确度。实验仿真证明,该算法较明显的提高了其收敛速度和精确度。%In order to overcome the basic artificial firefly algorithm (Glowworm swarm optimization,GSO)in solving global optimization problems,slow convergence speed,precision is not high,easily falling into the master problem. So,The paper puts forward an improved variable step optimization algorithm.To some extent,adopt the algorithm can avoid premature mature into a local optimum,and can achieve a higher accuracy in the later.Through simulation experiment,proves that the algorithm on the convergence speed and precision are obviously improved.

  9. 带高斯变异的人工萤火虫优化算法%Artificial glowworm swarm optimization algorithm with Gauss mutation

    Institute of Scientific and Technical Information of China (English)

    莫愿斌; 刘付永; 张宇楠

    2013-01-01

    针对基本萤火虫优化算法在求解函数全局最优值时的不足,提出了一种带高斯变异的人工萤火虫优化算法.该算法在萤火虫的移动过程中,应用了高斯变异策略,从而在一定程度上避免了算法陷入局部最优,且能获得精度更高的解.通过对六个标准测试函数进行测试,结果表明,改进后的人工萤火虫算法比基本萤火虫优化算法有更高的收敛速度、求解精度和收敛成功率.%According to the basic glowworm swarm optimization algorithm problems in solving the function of global optimal value, the paper put forward an artificial glowworm swarm optimization algorithm with Gauss mutation. The algorithm used a Gauss mutation strategy in the firefly mobile process, to prevent the algorithm into a local optimum in a certain extent, and obtained a more accurate solution. Finally, the test results of six standard test functions show that, the improved algorithm has higher convergence speed, solution precision and convergence rate of success than the basic GSO algorithm.

  10. 萤火虫算法的研究进展%The Research Progress of Glowworm Swarm Optimization

    Institute of Scientific and Technical Information of China (English)

    程春英

    2015-01-01

    Glowworm swarm optimization is a new type of swarm intelligence optimization algorithm by simulating the fireflies in foraging and mating habits of each other due to the light and attract mobile behavior to solve the optimal problem of.The Glowworm swarm optimization has strong robustness and stochastic searching capability, has been widely used in function optimization,clustering problems, robot cooperation,and many other aspects.This article expounds the basic principles of Glowworm swarm optimization,the existing various kinds of improved algorithm is given,and put forward the development direction of Glowworm swarm optimization.%萤火虫算法是通过模拟萤火虫在觅食和求偶等生活习性中产生的因光而吸引移动的行为来解决最优问题的一种新型群体智能优化算法。萤火虫算法因具有较强的鲁棒性和随机搜索性,已广泛地应用于函数寻优、聚类问题、机器人协作等多个方面。本文阐述了萤火虫算法的基本原理,给出了现有的各种改进算法,并展望了萤火虫算法的发展方向。

  11. A transgenic mouse model expressing an ERα folding biosensor reveals the effects of Bisphenol A on estrogen receptor signaling

    Science.gov (United States)

    Sekar, Thillai V.; Foygel, Kira; Massoud, Tarik F.; Gambhir, Sanjiv S.; Paulmurugan, Ramasamy

    2016-01-01

    Estrogen receptor-α (ERα) plays an important role in normal and abnormal physiology of the human reproductive system by interacting with the endogenous ligand estradiol (E2). However, other ligands, either analogous or dissimilar to E2, also bind to ERα. This may create unintentional activation of ER signaling in reproductive tissues that can lead to cancer development. We developed a transgenic mouse model that constitutively expresses a firefly luciferase (FLuc) split reporter complementation biosensor (NFLuc-ER-LBDG521T-CFLuc) to simultaneously evaluate the dynamics and potency of ligands that bind to ERα. We first validated this model using various ER ligands, including Raloxifene, Diethylstilbestrol, E2, and 4-hydroxytamoxifen, by employing FLuc-based optical bioluminescence imaging of living mice. We then used the model to investigate the carcinogenic property of Bisphenol A (BPA), an environmental estrogen, by long-term exposure at full and half environmental doses. We showed significant carcinogenic effects on female animals while revealing activated downstream ER signaling as measured by bioluminescence imaging. BPA induced tumor-like outgrowths in female transgenic mice, histopathologically confirmed to be neoplastic and epithelial in origin. This transgenic mouse model expressing an ERα folding-biosensor is useful in evaluation of estrogenic ligands and their downstream effects, and in studying environmental estrogen induced carcinogenesis in vivo. PMID:27721470

  12. Experimental Validation of Plasma Metasurfaces as Tunable THz Reflectors

    Science.gov (United States)

    Colon Quinones, Roberto; Underwood, Thomas; Cappelli, Mark

    2016-10-01

    Measurements are presented which validate the use of plasma metasurfaces (PMs) as potential tunable THz reflectors. The PM considered here is an n x n array of laser produced plasma kernels generated by focusing the fundamental output from a 2 J/p Q-switched Nd:YAG laser through a multi-lens array (MLA) and into a gas of varying pressure. An M Squared Firefly-THz laser is used to generate a collimated pulse of THz light, which is then directed to the PM at varying angles of incidence. The reflected energy is measured using a Gentec-EO SDX-1187 joulemeter probe to characterize the surface impedance or reflectivity. In this presentation, we will compare the measured reflectance to values obtained from theoretical predictions and 3D finite-difference time-domain (FDTD) simulations. Work supported by the Air Force Office of Scientific Research (AFOSR). R. Colon Quinones and T. Underwood acknowledge the support of the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

  13. Reporter Gene-Facilitated Detection of Compounds in Arabidopsis Leaf Extracts that Activate the Karrikin Signalling Pathway

    Directory of Open Access Journals (Sweden)

    Yueming Kelly Sun

    2016-12-01

    Full Text Available Karrikins are potent germination stimulants generated by the combustion of plant matter. Treatment of Arabidopsis with karrikins triggers a signalling process that is dependent upon a putative receptor protein KARRIKIN INSENSITIVE 2 (KAI2. KAI2 is a homologue of DWARF 14 (D14, the receptor for endogenous strigolactone hormones. Genetic analyses suggest that KAI2 also perceives endogenous signal(s that are not strigolactones. Activation of KAI2 by addition of karrikins to Arabidopsis plants induces expression of transcripts including D14-LIKE 2 (DLK2. We constructed the synthetic reporter gene DLK2:LUC in Arabidopsis, which comprises the firefly luciferase gene (LUC driven by the DLK2 promoter. Here we describe a luminescence-based reporter assay with Arabidopsis seeds to detect chemical signals that can activate the KAI2 signalling pathway. We demonstrate that the DLK2:LUC assay can selectively and sensitively detect karrikins and a functionally similar synthetic strigolactone analogue. Crucially we show that crude extracts from Arabidopsis leaves can also activate DLK2:LUC in a KAI2-dependent manner. Our work provides the first direct evidence for the existence of endogenous chemical signals that can activate the KAI2-mediated signalling pathway in Arabidopsis. This sensitive reporter system can now be used for the bioassay-guided purification and identification of putative endogenous KAI2 ligands or their precursors, and endogenous compounds that might modulate the KAI2 signalling pathway.

  14. Artificial Intelligence Mechanisms on Interactive Modified Simplex Method with Desirability Function for Optimising Surface Lapping Process

    Directory of Open Access Journals (Sweden)

    Pongchanun Luangpaiboon

    2014-01-01

    Full Text Available A study has been made to optimise the influential parameters of surface lapping process. Lapping time, lapping speed, downward pressure, and charging pressure were chosen from the preliminary studies as parameters to determine process performances in terms of material removal, lap width, and clamp force. The desirability functions of the-nominal-the-best were used to compromise multiple responses into the overall desirability function level or D response. The conventional modified simplex or Nelder-Mead simplex method and the interactive desirability function are performed to optimise online the parameter levels in order to maximise the D response. In order to determine the lapping process parameters effectively, this research then applies two powerful artificial intelligence optimisation mechanisms from harmony search and firefly algorithms. The recommended condition of (lapping time, lapping speed, downward pressure, and charging pressure at (33, 35, 6.0, and 5.0 has been verified by performing confirmation experiments. It showed that the D response level increased to 0.96. When compared with the current operating condition, there is a decrease of the material removal and lap width with the improved process performance indices of 2.01 and 1.14, respectively. Similarly, there is an increase of the clamp force with the improved process performance index of 1.58.

  15. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Liu, Yan-Hong [Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin, Heilongjiang 150081 (China); Li, Yan; Wang, Jia-Ye [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Hattori, Toshio [Department of Emerging Infectious Diseases, Division of Internal Medicine, Graduate School of Medicine, Tohoku University, Sendai 9808574 (Japan); Ling, Hong, E-mail: lingh@ems.hrbmu.edu.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Department of Parasitology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China); Zhang, Feng-Min, E-mail: fengminzhang@yahoo.com.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China)

    2010-01-22

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  16. Immunomagnetic separation and rapid detection of bacteria using bioluminescence and microfluidics.

    Science.gov (United States)

    Qiu, Jingmin; Zhou, Yun; Chen, Hui; Lin, Jin-Ming

    2009-08-15

    This paper describes an immunomagnetic separation of target bacterial cells from others by using magnetic bead. The surface of bead was coated with antibodies which can capture specific organism. The binding efficiency of immunomagnetic bead (IMB) capturing target bacterial cells was higher than 98% when the concentrations of target and interferent bacterial cells were at the same level. The concentration of bacteria was determined indirectly by detecting adenosine 5'-triphosphate (ATP) employing bioluminescence (BL) reaction of firefly luciferin-ATP. Benzalkonium chloride (BAC) was used as an ATP extractant from living bacterial cells. We found that BAC could enhance the light emission when the concentration of BAC was less than 5.3 x 10(-2)% (w/v) and the BL intensity reached its maximum at the concentration of BAC was 2.7 x 10(-2)%, which was 10-fold stronger than that without BAC. Based on the principle of the IMB, a microfluidic chip combined with immunofluorescence assay for separating and detecting bacteria simultaneously was also developed. The IMBs were magnetically fixed in the bead-beds of chip channels with a 3-mm diameter of NdFeB permanent magnet. The target bacterial cells can be captured magnetically and observed by a fluorescent microscope.

  17. Bioluminescence regenerative cycle (BRC) system for nucleic acid quantification assays

    Science.gov (United States)

    Hassibi, Arjang; Lee, Thomas H.; Davis, Ronald W.; Pourmand, Nader

    2003-07-01

    A new label-free methodology for nucleic acid quantification has been developed where the number of pyrophosphate molecules (PPi) released during polymerization of the target nucleic acid is counted and correlated to DNA copy number. The technique uses the enzymatic complex of ATP-sulfurylase and firefly luciferase to generate photons from PPi. An enzymatic unity gain positive feedback is also implemented to regenerate the photon generation process and compensate any decay in light intensity by self regulation. Due to this positive feedback, the total number of photons generated by the bioluminescence regenerative cycle (BRC) can potentially be orders of magnitude higher than typical chemiluminescent processes. A system level kinetic model that incorporates the effects of contaminations and detector noise was used to show that the photon generation process is in fact steady and also proportional to the nucleic acid quantity. Here we show that BRC is capable of detecting quantities of DNA as low as 1 amol (10-18 mole) in 40μlit aqueous solutions, and this enzymatic assay has a controllable dynamic range of 5 orders of magnitude. The sensitivity of this technology, due to the excess number of photons generated by the regenerative cycle, is not constrained by detector performance, but rather by possible PPi or ATP (adenosine triphosphate) contamination, or background bioluminescence of the enzymatic complex.

  18. An efficient extraction method for quantitation of adenosine triphosphate in mammalian tissues and cells.

    Science.gov (United States)

    Chida, Junji; Yamane, Kazuhiko; Takei, Tunetomo; Kido, Hiroshi

    2012-05-21

    Firefly bioluminescence is widely used in the measurement of adenosine 5'-triphosphate (ATP) levels in biological materials. For such assays in tissues and cells, ATP must be extracted away from protein in the initial step and extraction efficacy is the main determinant of the assay accuracy. Extraction reagents recommended in the commercially available ATP assay kits are chaotropic reagents, trichloroacetic acid (TCA), perchloric acid (PCA), and ethylene glycol (EG), which extract nucleotides through protein precipitation and/or nucleotidase inactivation. We found that these reagents are particularly useful for measuring ATP levels in materials with relatively low protein concentrations such as blood cells, cultured cells, and bacteria. However, these methods are not suitable for ATP extraction from tissues with high protein concentrations, because some ATP may be co-precipitated with the insolubilized protein during homogenization and extraction, and it could also be precipitated by neutralization in the acid extracts. Here we found that a phenol-based extraction method markedly increased the ATP and other nucleotides extracted from tissues. In addition, phenol extraction does not require neutralization before the luciferin-luciferase assay step. ATP levels analyzed by luciferase assay in various tissues extracted by Tris-EDTA-saturated phenol (phenol-TE) were over 17.8-fold higher than those extracted by TCA and over 550-fold higher than those in EG extracts. Here we report a simple, rapid, and reliable phenol-TE extraction procedure for ATP measurement in tissues and cells by luciferase assay.

  19. Characterization and function of stentorin, the photoreceptor protein in Stentor coeruleus

    Energy Technology Data Exchange (ETDEWEB)

    Huh, J.W.

    1987-01-01

    Stentorin is a photoreceptor protein that is responsible for the step-up photophobic response and the negative phototaxis of an aneural unicellular ciliate protozoan, Stentor coeruleus. This protein was solubilized from the membrane of pigment granules and purified by the combination of gel filtration, hydroxylapatite chromatography, and DEAE-sepharose anionic exchange chromatography. SDS polyacrylamide gel electrophoresis revealed two red fluorescent bands for the purified stentorin reflecting the microheterogeneity of stentorin. The fluorescence lifetime study of stentorin employing the deuterium solvent isotope effect was conducted to confirm the proton dissociation from the chromophore at the excited state as a primary signal in the photosensory transduction in S. coeruleus. The increase of the amplitude of the anionic lifetime component in going from H/sub 2/O buffer to D/sub 2/O buffer is suggestive of the existence of the conjugate acid-base network of the photoreceptor protein for fast proton transfer. ATP-involvement in the photoresponse of S. coeruleus was investigated by using the firefly bioluminescence for ATP assay and the incorporation of /sup 32/Pi into ATP. Light-induced ATP level variation was detected only when cellular ATP was extracted by the boiling water method. The cellular ATP level was constant regardless of light illumination when extracted by trichloroacetic acid (TCA).

  20. A novel Listeria monocytogenes-based DNA delivery system for cancer gene therapy.

    LENUS (Irish Health Repository)

    van Pijkeren, Jan Peter

    2012-01-31

    Bacteria-mediated transfer of plasmid DNA to mammalian cells (bactofection) has been shown to have significant potential as an approach to express heterologous proteins in various cell types. This is achieved through entry of the entire bacterium into cells, followed by release of plasmid DNA. In a murine model, we show that Listeria monocytogenes can invade and spread in tumors, and establish the use of Listeria to deliver genes to tumors in vivo. A novel approach to vector lysis and release of plasmid DNA through antibiotic administration was developed. Ampicillin administration facilitated both plasmid transfer and safety control of vector. To further improve on the gene delivery system, we selected a Listeria monocytogenes derivative that is more sensitive to ampicillin, and less pathogenic than the wild-type strain. Incorporation of a eukaryotic-transcribed lysin cassette in the plasmid further increased bacterial lysis. Successful gene delivery of firefly luciferase to growing tumors in murine models and to patient breast tumor samples ex vivo was achieved. The model described encompasses a three-phase treatment regimen, involving (1) intratumoral administration of vector followed by a period of vector spread, (2) systemic ampicillin administration to induce vector lysis and plasmid transfer, and (3) systemic administration of combined moxifloxacin and ampicillin to eliminate systemic vector. For the first time, our results reveal the potential of Listeria monocytogenes for in vivo gene delivery.

  1. Towards semi-automatic rock mass discontinuity orientation and set analysis from 3D point clouds

    Science.gov (United States)

    Guo, Jiateng; Liu, Shanjun; Zhang, Peina; Wu, Lixin; Zhou, Wenhui; Yu, Yinan

    2017-06-01

    Obtaining accurate information on rock mass discontinuities for deformation analysis and the evaluation of rock mass stability is important. Obtaining measurements for high and steep zones with the traditional compass method is difficult. Photogrammetry, three-dimensional (3D) laser scanning and other remote sensing methods have gradually become mainstream methods. In this study, a method that is based on a 3D point cloud is proposed to semi-automatically extract rock mass structural plane information. The original data are pre-treated prior to segmentation by removing outlier points. The next step is to segment the point cloud into different point subsets. Various parameters, such as the normal, dip/direction and dip, can be calculated for each point subset after obtaining the equation of the best fit plane for the relevant point subset. A cluster analysis (a point subset that satisfies some conditions and thus forms a cluster) is performed based on the normal vectors by introducing the firefly algorithm (FA) and the fuzzy c-means (FCM) algorithm. Finally, clusters that belong to the same discontinuity sets are merged and coloured for visualization purposes. A prototype system is developed based on this method to extract the points of the rock discontinuity from a 3D point cloud. A comparison with existing software shows that this method is feasible. This method can provide a reference for rock mechanics, 3D geological modelling and other related fields.

  2. Rational Design of a Triple Reporter Gene for Multimodality Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Ya-Ju Hsieh

    2014-01-01

    Full Text Available Multimodality imaging using noncytotoxic triple fusion (TF reporter genes is an important application for cell-based tracking, drug screening, and therapy. The firefly luciferase (fl, monomeric red fluorescence protein (mrfp, and truncated herpes simplex virus type 1 thymidine kinase SR39 mutant (ttksr39 were fused together to create TF reporter gene constructs with different order. The enzymatic activities of TF protein in vitro and in vivo were determined by luciferase reporter assay, H-FEAU cellular uptake experiment, bioluminescence imaging, and micropositron emission tomography (microPET. The TF construct expressed in H1299 cells possesses luciferase activity and red fluorescence. The tTKSR39 activity is preserved in TF protein and mediates high levels of H-FEAU accumulation and significant cell death from ganciclovir (GCV prodrug activation. In living animals, the luciferase and tTKSR39 activities of TF protein have also been successfully validated by multimodality imaging systems. The red fluorescence signal is relatively weak for in vivo imaging but may expedite FACS-based selection of TF reporter expressing cells. We have developed an optimized triple fusion reporter construct DsRedm-fl-ttksr39 for more effective and sensitive in vivo animal imaging using fluorescence, bioluminescence, and PET imaging modalities, which may facilitate different fields of biomedical research and applications.

  3. Application of genetic programming in shape optimization of concrete gravity dams by metaheuristics

    Directory of Open Access Journals (Sweden)

    Abdolhossein Baghlani

    2014-12-01

    Full Text Available A gravity dam maintains its stability against the external loads by its massive size. Hence, minimization of the weight of the dam can remarkably reduce the construction costs. In this paper, a procedure for finding optimal shape of concrete gravity dams with a computationally efficient approach is introduced. Genetic programming (GP in conjunction with metaheuristics is used for this purpose. As a case study, shape optimization of the Bluestone dam is presented. Pseudo-dynamic analysis is carried out on a total number of 322 models in order to establish a database of the results. This database is then used to find appropriate relations based on GP for design criteria of the dam. This procedure eliminates the necessity of the time-consuming process of structural analyses in evolutionary optimization methods. The method is hybridized with three different metaheuristics, including particle swarm optimization, firefly algorithm (FA, and teaching–learning-based optimization, and a comparison is made. The results show that although all algorithms are very suitable, FA is slightly superior to other two algorithms in finding a lighter structure in less number of iterations. The proposed method reduces the weight of dam up to 14.6% with very low computational effort.

  4. Consensus and Synchronization in Complex Networks

    CERN Document Server

    2013-01-01

    Synchronization in complex networks is one of the most captivating cooperative phenomena in nature and has been shown to be of fundamental importance in such varied circumstances as the continued existence of species, the functioning of heart pacemaker cells, epileptic seizures, neuronal firing in the feline visual cortex and cognitive tasks in humans. E.g. coupled visual and acoustic interactions make fireflies flash, crickets chirp, and an audience clap in unison. On the other hand, in distributed systems and networks, it is often necessary for some or all of the nodes to calculate some function of certain parameters, e.g. sink nodes in sensor networks being tasked with calculating the average measurement value of all the sensors or multi-agent systems in which all agents are required to coordinate their speed and direction. When all nodes calculate the same function of the initial values in the system, they are said to reach consensus. Such concepts - sometimes also called state agreement, rendezvous, and ...

  5. Synthetic dual-input mammalian genetic circuits enable tunable and stringent transcription control by chemical and light.

    Science.gov (United States)

    Chen, Xianjun; Li, Ting; Wang, Xue; Du, Zengmin; Liu, Renmei; Yang, Yi

    2016-04-01

    Programmable transcription factors can enable precise control of gene expression triggered by a chemical inducer or light. To obtain versatile transgene system with combined benefits of a chemical inducer and light inducer, we created various chimeric promoters through the assembly of different copies of the tet operator and Gal4 operator module, which simultaneously responded to a tetracycline-responsive transcription factor and a light-switchable transactivator. The activities of these chimeric promoters can be regulated by tetracycline and blue light synergistically or antagonistically. Further studies of the antagonistic genetic circuit exhibited high spatiotemporal resolution and extremely low leaky expression, which therefore could be used to spatially and stringently control the expression of highly toxic protein Diphtheria toxin A for light regulated gene therapy. When transferring plasmids engineered for the gene switch-driven expression of a firefly luciferase (Fluc) into mice, the Fluc expression levels of the treated animals directly correlated with the tetracycline and light input program. We suggest that dual-input genetic circuits using TET and light that serve as triggers to achieve expression profiles may enable the design of robust therapeutic gene circuits for gene- and cell-based therapies.

  6. 群体智能和智能优化算法%Swarm intelligence and smart optimization algorithms

    Institute of Scientific and Technical Information of China (English)

    杨新社; 贺兴时

    2013-01-01

    通常元启发式优化算法是基于群体智能的算法,这些算法通常被称为智能算法。此文综述一些广泛应用的优化算法,包括蚁群算法、蜜蜂算法、蝙蝠算法、布谷鸟搜索、萤火虫算法和粒子群优化。同时,还讨论启发式算法中具有挑战性的问题如参数调整和参数控制。%Metaheuristic optimization algorithms are usually based on swarm intelligence ,and these algorithms are often referred to as smart algorithms .We review some of the widely used algorithms for optimization ,including ant and bee algorithms ,bat algorithm ,cuckoo search , firefly algorithm and particle swarm optimization .We also discuss the challenging issues con-cerning parameter tuning and parameter control in metaheuristic algorithms .

  7. Triple Bioluminescence Imaging for In Vivo Monitoring of Cellular Processes

    Directory of Open Access Journals (Sweden)

    Casey A Maguire

    2013-01-01

    Full Text Available Bioluminescence imaging (BLI has shown to be crucial for monitoring in vivo biological processes. So far, only dual bioluminescence imaging using firefly (Fluc and Renilla or Gaussia (Gluc luciferase has been achieved due to the lack of availability of other efficiently expressed luciferases using different substrates. Here, we characterized a codon-optimized luciferase from Vargula hilgendorfii (Vluc as a reporter for mammalian gene expression. We showed that Vluc can be multiplexed with Gluc and Fluc for sequential imaging of three distinct cellular phenomena in the same biological system using vargulin, coelenterazine, and D-luciferin substrates, respectively. We applied this triple imaging system to monitor the effect of soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL delivered using an adeno-associated viral vector (AAV on brain tumors in mice. Vluc imaging showed efficient sTRAIL gene delivery to the brain, while Fluc imaging revealed a robust antiglioma therapy. Further, nuclear factor-κB (NF-κB activation in response to sTRAIL binding to glioma cells death receptors was monitored by Gluc imaging. This work is the first demonstration of trimodal in vivo bioluminescence imaging and will have a broad applicability in many different fields including immunology, oncology, virology, and neuroscience.

  8. Fully codon-optimized luciferase uncovers novel temperature characteristics of the Neurospora clock.

    Science.gov (United States)

    Gooch, Van D; Mehra, Arun; Larrondo, Luis F; Fox, Julie; Touroutoutoudis, Melissa; Loros, Jennifer J; Dunlap, Jay C

    2008-01-01

    We report the complete reconstruction of the firefly luciferase gene, fully codon optimized for expression in Neurospora crassa. This reporter enhances light output by approximately 4 log orders over that with previously available versions, now producing light that is visible to the naked eye and sufficient for monitoring the activities of many poorly expressed genes. Time lapse photography of strains growing in race tubes, in which the frq or eas/ccg-2 promoter is used to drive luciferase, shows the highest levels of luciferase activity near the growth front and newly formed conidial bands. Further, we have established a sorbose medium colony assay that will facilitate luciferase-based screens. The signals from sorbose-grown colonies of strains in which the frq promoter drives luciferase exhibit the properties of circadian rhythms and can be tracked for many days to weeks. This reporter now makes it possible to follow the clock in real time, even in strains or under conditions in which the circadian rhythm in conidial banding is not expressed. This property has been used to discover short, ca. 15-h period rhythms at high temperatures, at which banding becomes difficult to observe in race tubes, and to generate a high-resolution temperature phase-response curve.

  9. Noninvasive bioluminescence imaging of the dynamics of sanguinarine induced apoptosis via activation of reactive oxygen species.

    Science.gov (United States)

    Wang, Yan; Zhang, Beilei; Liu, Wei; Dai, Yunpeng; Shi, Yaru; Zeng, Qi; Wang, Fu

    2016-04-19

    Most chemotherapeutic drugs exert their anti-tumor effects primarily by triggering a final pathway leading to apoptosis. Noninvasive imaging of apoptotic events in preclinical models would greatly facilitate the development of apoptosis-inducing compounds and evaluation of their therapeutic efficacy. Here we employed a cyclic firefly luciferase (cFluc) reporter to screen potential pro-apoptotic compounds from a number of natural agents. We demonstrated that sanguinarine (SANG) could induce apoptosis in a dose- and time-dependent manner in UM-SCC-22B head and neck cancer cells. Moreover, SANG-induced apoptosis was associated with the generation of reactive oxygen species (ROS) and activation of c-Jun-N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) signal pathways. After intravenous administration with SANG in 22B-cFluc xenograft models, a dramatic increase of luminescence signal can be detected as early as 48 h post-treatment, as revealed by longitudinal bioluminescence imaging in vivo. Remarkable apoptotic cells reflected from ex vivo TUNEL staining confirmed the imaging results. Importantly, SANG treatment caused distinct tumor growth retardation in mice compared with the vehicle-treated group. Taken together, our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cFluc reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation.

  10. NanoLuc: A Small Luciferase Is Brightening Up the Field of Bioluminescence.

    Science.gov (United States)

    England, Christopher G; Ehlerding, Emily B; Cai, Weibo

    2016-05-18

    The biomedical field has greatly benefited from the discovery of bioluminescent proteins. Currently, scientists employ bioluminescent systems for numerous biomedical applications, ranging from highly sensitive cellular assays to bioluminescence-based molecular imaging. Traditionally, these systems are based on Firefly and Renilla luciferases; however, the applicability of these enzymes is limited by their size, stability, and luminescence efficiency. NanoLuc (NLuc), a novel bioluminescence platform, offers several advantages over established systems, including enhanced stability, smaller size, and >150-fold increase in luminescence. In addition, the substrate for NLuc displays enhanced stability and lower background activity, opening up new possibilities in the field of bioluminescence imaging. The NLuc system is incredibly versatile and may be utilized for a wide array of applications. The increased sensitivity, high stability, and small size of the NLuc system have the potential to drastically change the field of reporter assays in the future. However, as with all such technology, NLuc has limitations (including a nonideal emission for in vivo applications and its unique substrate) which may cause it to find restricted use in certain areas of molecular biology. As this unique technology continues to broaden, NLuc may have a significant impact in both preclinical and clinical fields, with potential roles in disease detection, molecular imaging, and therapeutic monitoring. This review will present the NLuc technology to the scientific community in a nonbiased manner, allowing the audience to adopt their own views of this novel system.

  11. Bioluminescent imaging of vaccinia virus infection in immunocompetent and immunodeficient rats as a model for human smallpox

    Science.gov (United States)

    Liu, Qiang; Fan, Changfa; Zhou, Shuya; Guo, Yanan; Zuo, Qin; Ma, Jian; Liu, Susu; Wu, Xi; Peng, Zexu; Fan, Tao; Guo, Chaoshe; Shen, Yuelei; Huang, Weijin; Li, Baowen; He, Zhengming; Wang, Youchun

    2015-01-01

    Due to the increasing concern of using smallpox virus as biological weapons for terrorist attack, there is renewed interest in studying the pathogenesis of human smallpox and development of new therapies. Animal models are highly demanded for efficacy and safety examination of new vaccines and therapeutic drugs. Here, we demonstrated that both wild type and immunodeficient rats infected with an engineered vaccinia virus carrying Firefly luciferase reporter gene (rTV-Fluc) could recapitulate infectious and clinical features of human smallpox. Vaccinia viral infection in wild type Sprague-Dawley (SD) rats displayed a diffusible pattern in various organs, including liver, head and limbs. The intensity of bioluminescence generated from rTV-Fluc correlated well with viral loads in tissues. Moreover, neutralizing antibodies had a protective effect against virus reinfection. The recombination activating gene 2 (Rag2) knockout rats generated by transcription activator-like effector nucleases (TALENs) technology were further used to examine the infectivity of the rTV-Fluc in immunodeficient populations. Here we demonstrated that Rag2-/- rats were more susceptible to rTV-Fluc than SD rats with a slower virus clearance rate. Therefore, the rTV-Fluc/SD rats and rTV-Fluc/Rag2-/- rats are suitable visualization models, which recapitulate wild type or immunodeficient populations respectively, for testing human smallpox vaccine and antiviral drugs. PMID:26235050

  12. The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons.

    Science.gov (United States)

    Nicoll, Michael P; Hann, William; Shivkumar, Maitreyi; Harman, Laura E R; Connor, Viv; Coleman, Heather M; Proença, João T; Efstathiou, Stacey

    2016-04-01

    Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir.

  13. Rapid and Quantitative Assessment of Cancer Treatment Response Using In Vivo Bioluminescence Imaging

    Directory of Open Access Journals (Sweden)

    Alnawaz Rehemtulla

    2000-01-01

    Full Text Available Current assessment of orthotopic tumor models in animals utilizes survival as the primary therapeutic end point. In vivo bioluminescence imaging (BLI is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating antineoplastic therapies [1 ]. Using human tumor cell lines constitutively expressing luciferase, the kinetics of tumor growth and response to therapy have been assessed in intraperitoneal [2], subcutaneous, and intravascular [3] cancer models. However, use of this approach for evaluating orthotopic tumor models has not been demonstrated. In this report, the ability of BLI to noninvasively quantitate the growth and therapeuticinduced cell kill of orthotopic rat brain tumors derived from 9L gliosarcoma cells genetically engineered to stably express firefly luciferase (9LLuc was investigated. Intracerebral tumor burden was monitored over time by quantitation of photon emission and tumor volume using a cryogenically cooled CCD camera and magnetic resonance imaging (MRI, respectively. There was excellent correlation (r=0.91 between detected photons and tumor volume. A quantitative comparison of tumor cell kill determined from serial MRI volume measurements and BLI photon counts following 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU treatment revealed that both imaging modalities yielded statistically similar cell kill values (P=.951. These results provide direct validation of BLI imaging as a powerful and quantitative tool for the assessment of antineoplastic therapies in living animals.

  14. Towards Enhancement of Performance of K-Means Clustering Using Nature-Inspired Optimization Algorithms

    Directory of Open Access Journals (Sweden)

    Simon Fong

    2014-01-01

    Full Text Available Traditional K-means clustering algorithms have the drawback of getting stuck at local optima that depend on the random values of initial centroids. Optimization algorithms have their advantages in guiding iterative computation to search for global optima while avoiding local optima. The algorithms help speed up the clustering process by converging into a global optimum early with multiple search agents in action. Inspired by nature, some contemporary optimization algorithms which include Ant, Bat, Cuckoo, Firefly, and Wolf search algorithms mimic the swarming behavior allowing them to cooperatively steer towards an optimal objective within a reasonable time. It is known that these so-called nature-inspired optimization algorithms have their own characteristics as well as pros and cons in different applications. When these algorithms are combined with K-means clustering mechanism for the sake of enhancing its clustering quality by avoiding local optima and finding global optima, the new hybrids are anticipated to produce unprecedented performance. In this paper, we report the results of our evaluation experiments on the integration of nature-inspired optimization methods into K-means algorithms. In addition to the standard evaluation metrics in evaluating clustering quality, the extended K-means algorithms that are empowered by nature-inspired optimization methods are applied on image segmentation as a case study of application scenario.

  15. The 5′-untranslated region of the mouse mammary tumor virus mRNA exhibits cap-independent translation initiation

    Science.gov (United States)

    Vallejos, Maricarmen; Ramdohr, Pablo; Valiente-Echeverría, Fernando; Tapia, Karla; Rodriguez, Felipe E.; Lowy, Fernando; Huidobro-Toro, J. Pablo; Dangerfield, John A.; López-Lastra, Marcelo

    2010-01-01

    In this study, we demonstrate the identification of an internal ribosome entry site (IRES) within the 5′-untranslated region (5′-UTR) of the mouse mammary tumor virus (MMTV). The 5′-UTR of the full-length mRNA derived from the infectious, complete MMTV genome was cloned into a dual luciferase reporter construct containing an upstream Renilla luciferase gene (RLuc) and a downstream firefly luciferase gene (FLuc). In rabbit reticulocyte lysate, the MMTV 5′-UTR was capable of driving translation of the second cistron. In vitro translational activity from the MMTV 5′-UTR was resistant to the addition of m7GpppG cap-analog and cleavage of eIF4G by foot-and-mouth disease virus (FMDV) L-protease. IRES activity was also demonstrated in the Xenopus laevis oocyte by micro-injection of capped and polyadenylated bicistronic RNAs harboring the MMTV-5′-UTR. Finally, transfection assays showed that the MMTV-IRES exhibits cell type-dependent translational activity, suggesting a requirement for as yet unidentified cellular factors for its optimal function. PMID:19889724

  16. Construction of an Artificial MicroRNA Expression Vector for Simultaneous Inhibition of Multiple Genes in Mammalian Cells

    Directory of Open Access Journals (Sweden)

    Deyin Guo

    2009-05-01

    Full Text Available Recently, artificial microRNA (amiRNA has become a promising RNA interference (RNAi technology. Here, we describe a flexible and reliable method for constructing both single- and multi-amiRNA expression vectors. Two universal primers, together with two specific primers carrying the encoding sequence of amiRNA were designed and utilized to synthesize the functional amiRNA cassette through a one-step PCR. With appropriate restriction sites, the synthesized amiRNA cassettes can be cloned into any site of different destination vectors. Using the method, we constructed both single- and multi-amiRNA expression vectors to target three reporter genes, which code firefly luciferase (Fluc, enhanced green fluorescent protein (EGFP and β-galactosidase (LacZ, respectively. The expressions of three genes were all specifically inhibited by either the corresponding single- or the multi-amiRNA expression vector in 293T cells. And the RNAi efficiency of each amiRNA produced by both single- and multi-amiRNA expression vectors was comparable.

  17. Image-guided genomic analysis of tissue response to laser-induced thermal stress

    Science.gov (United States)

    Mackanos, Mark A.; Helms, Mike; Kalish, Flora; Contag, Christopher H.

    2011-05-01

    The cytoprotective response to thermal injury is characterized by transcriptional activation of ``heat shock proteins'' (hsp) and proinflammatory proteins. Expression of these proteins may predict cellular survival. Microarray analyses were performed to identify spatially distinct gene expression patterns responding to thermal injury. Laser injury zones were identified by expression of a transgene reporter comprised of the 70 kD hsp gene and the firefly luciferase coding sequence. Zones included the laser spot, the surrounding region where hsp70-luc expression was increased, and a region adjacent to the surrounding region. A total of 145 genes were up-regulated in the laser irradiated region, while 69 were up-regulated in the adjacent region. At 7 hours the chemokine Cxcl3 was the highest expressed gene in the laser spot (24 fold) and adjacent region (32 fold). Chemokines were the most common up-regulated genes identified. Microarray gene expression was successfully validated using qRT- polymerase chain reaction for selected genes of interest. The early response genes are likely involved in cytoprotection and initiation of the healing response. Their regulatory elements will benefit creating the next generation reporter mice and controlling expression of therapeutic proteins. The identified genes serve as drug development targets that may prevent acute tissue damage and accelerate healing.

  18. Sleeping Beauty transposon system is a reliable gene delivery tool for hereditary tyrosinaemia type 1 disease gene therapy: size of the foreign gene decides the timing of stable integration into the host chromosomes.

    Science.gov (United States)

    Pan, X-J; Ma, Z-Z; Zhang, Q-J; Fan, L; Li, Q-H

    2012-01-01

    This study investigated compensation for loss of the fumaryl-acetoacetate hydrolase gene (Fah) by gene therapy using the Sleeping Beauty transposon system (SBTS), in a hereditary tyrosinaemia type 1 (HT-1) mouse model (Fah-/-). Twenty Fah-/- study mice, five wild-type positive controls and five Fah-/- negative controls were included. All Fah-/- mice received 2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclo hexaedione (NTBC). Fah-/- study mice were randomly injected with one of two SBTS constructs: Fah-SBTS (containing mouse Fah gene), or forkhead box M1b (FOXM1B)-Fah-SBTS (containing mouse Fah and human FOXM1B genes). Firefly luciferase-SBTS was injected as a trace marker. NTBC treatment stopped after construct injection; Fah-/- negative controls were kept healthy with continued NTBC. Mice were weighed daily; the luciferase signal was monitored by in vivo bioluminescence, and Fah and FOXM1B gene expression were evaluated. The Fah gene integrated into the mouse chromosomes within 1 week of Fah-SBTS injection (mice survived without NTBC thereafter) and within 1 month of FOXM1B-Fah-SBTS injection (mice lost weight dramatically and needed additional NTBC). The shorter Fah gene had an advantage over the longer FOXM1B-Fah gene for stable integration into the host mouse chromosomes.

  19. In vivo bioluminescence imaging of neurogenesis - the role of the blood brain barrier in an experimental model of Parkinson's disease.

    Science.gov (United States)

    Fricke, Inga B; Schelhaas, Sonja; Zinnhardt, Bastian; Viel, Thomas; Hermann, Sven; Couillard-Després, Sébastien; Jacobs, Andreas H

    2017-02-13

    Bioluminescence imaging in transgenic mice expressing firefly luciferase in Doublecortin(+) (Dcx) neuroblasts might serve as a powerful tool to study the role of neurogenesis in models of brain injury and neurodegeneration using non-invasive, longitudinal in vivo imaging. Therefore, we aimed to use BLI in B6(Cg)-Tyrc-2J/J Dcx-Luc (Doublecortin-Luciferase, Dcx-Luc) mice to investigate its suitability to assess neurogenesis in a unilateral injection model of Parkinson's disease. We further aimed to assess the blood brain barrier leakage associated with the intranigral 6-OHDA injection to evaluate its impact on substrate delivery and bioluminescence signal intensity. Two weeks after lesion, we observed an increase in bioluminescence signal in the ipsilateral hippocampal region in both, 6-OHDA and vehicle injected Dcx-Luc mice. At the same time, no corresponding increase in Dcx(+) neuroblast numbers could be observed in the dentate gyrus of C57Bl6 mice. Blood brain barrier leakage was observed in the hippocampal region and in the degenerating substantia nigra of C57Bl6 mice in vivo using T1 weighted Magnetic Resonance Imaging with Gadovist(®) and ex vivo using Evans Blue Fluorescence Reflectance Imaging and mouse Immunoglobulin G staining. Our data suggests a BLI signal dependency on blood brain barrier permeability, underlining a major pitfall of substrate/tracer dependent imaging in invasive disease models.

  20. A Hybrid Approach to Solve a Model of Closed-Loop Supply Chain

    Directory of Open Access Journals (Sweden)

    Nafiseh Tokhmehchi

    2015-01-01

    Full Text Available This paper investigates a closed-loop supply chain network, including plants, demand centers, as well as collection centers, and disposal centers. In forward flow, the products are directly sent to demand centers, after being produced by plants, but in the reverse flow, reused products are returned to collection centers and, after investigating, are partly sent to disposal centers and the other part is resent to plants for remanufacturing. The proposed mathematical model is based on mixed-integer programming and helps minimizing the total cost. Total costs include the expenditure of establishing new centers, producing new products, cargo transport in the network, and disposal. The model aims to answer these two questions. (1 What number and in which places the plants, collection centers, and disposal centers will be constructed. (2 What amount of products will be flowing in each segment of the chain, in order to minimize the total cost. Four types of tuned metaheuristic algorithms were used, which are hybrid forms of genetic and firefly algorithms. Finally an adequate number of instances are generated to analyse the behavior of proposed algorithms. Computational results reveal that iterative sequentialization hybrid provides better solution compared with the other approaches in large size.

  1. Evaluation of the influenza A replicon for transient expression of recombinant proteins in mammalian cells.

    Science.gov (United States)

    Krammer, Florian; Pontiller, Jens; Tauer, Christopher; Palmberger, Dieter; Maccani, Andreas; Baumann, Martina; Grabherr, Reingard

    2010-10-11

    Recombinant protein expression in mammalian cells has become a very important technique over the last twenty years. It is mainly used for production of complex proteins for biopharmaceutical applications. Transient recombinant protein expression is a possible strategy to produce high quality material for preclinical trials within days. Viral replicon based expression systems have been established over the years and are ideal for transient protein expression. In this study we describe the evaluation of an influenza A replicon for the expression of recombinant proteins. We investigated transfection and expression levels in HEK-293 cells with EGFP and firefly luciferase as reporter proteins. Furthermore, we studied the influence of different influenza non-coding regions and temperature optima for protein expression as well. Additionally, we exploited the viral replication machinery for the expression of an antiviral protein, the human monoclonal anti-HIV-gp41 antibody 3D6. Finally we could demonstrate that the expression of a single secreted protein, an antibody light chain, by the influenza replicon, resulted in fivefold higher expression levels compared to the usually used CMV promoter based expression. We emphasize that the influenza A replicon system is feasible for high level expression of complex proteins in mammalian cells.

  2. Evaluation of canonical siRNA and Dicer substrate RNA for inhibition of hepatitis C virus genome replication--a comparative study.

    Directory of Open Access Journals (Sweden)

    Bruno Carneiro

    Full Text Available Hepatitis C virus (HCV frequently establishes persistent infections in the liver, leading to the development of chronic hepatitis and, potentially, to liver cirrhosis and hepatocellular carcinoma at later stages. The objective of this study was to test the ability of five Dicer substrate siRNAs (DsiRNA to inhibit HCV replication and to compare these molecules to canonical 21 nt siRNA. DsiRNA molecules were designed to target five distinct regions of the HCV genome - the 5' UTR and the coding regions for NS3, NS4B, NS5A or NS5B. These molecules were transfected into Huh7.5 cells that stably harboured an HCV subgenomic replicon expressing a firefly luciferase/neoR reporter (SGR-Feo-JFH-1 and were also tested on HCVcc-infected cells. All of the DsiRNAs inhibited HCV replication in both the subgenomic system and HCVcc-infected cells. When DsiRNAs were transfected prior to infection with HCVcc, the inhibition levels reached 99.5%. When directly compared, canonical siRNA and DsiRNA exhibited similar potency of virus inhibition. Furthermore, both types of molecules exhibited similar dynamics of inhibition and frequencies of resistant mutants after 21 days of treatment. Thus, DsiRNA molecules are as potent as 21 nt siRNAs for the inhibition of HCV replication and may provide future approaches for HCV therapy if the emergence of resistant mutants can be addressed.

  3. "Past the brink of tacit support": Fan activism and the Whedonverses

    Directory of Open Access Journals (Sweden)

    Tanya R. Cochran

    2012-06-01

    Full Text Available For decades, the phrase fan activism has referred almost exclusively to television fans' efforts to save their favorite series. These campaigns—dating at least as far back as the original Star Trek (1966–69 to the more recent Farscape (1999–2003, Firefly (2002–3, Jericho (2006–8, and Veronica Mars (2004–7, among others—appear effective at catalyzing fan involvement, yet are largely ineffective at saving series. In other words, while it may achieve some secondary, albeit significant, victories such as tighter-knit relationships among fans, fan crusading rarely seems to end with the supposed primary goal of activist labors: more installments of the texts devotees admire and love. Recently, however, the phenomenon of fan activism has taken on a new dimension, and scholars are beginning to take note by asking several important questions. As Henry Jenkins asks, how does a fan move from "participatory culture to public participation"? And what does this move mean? As one might expect, there are many reasons for and implications that emerge from this reallocation of such devoted attention. To explore some of those reasons and implications, the author considers some of the devotees of television auteur Joss Whedon, their activist efforts, and the distinct ways Whedon inspires a politically participatory fan following. Ultimately, the author contends that through their activism, many enthusiasts of the Whedonverses extend the worlds of Whedon's stories by consciously constructing a sociopolitical, feminist identity.

  4. Metabolic inactivation of the circadian transmitter, pigment dispersing factor (PDF), by neprilysin-like peptidases in Drosophila.

    Science.gov (United States)

    Isaac, R Elwyn; Johnson, Erik C; Audsley, Neil; Shirras, Alan D

    2007-12-01

    Recent studies have firmly established pigment dispersing factor (PDF), a C-terminally amidated octodecapeptide, as a key neurotransmitter regulating rhythmic circadian locomotory behaviours in adult Drosophila melanogaster. The mechanisms by which PDF functions as a circadian peptide transmitter are not fully understood, however; in particular, nothing is known about the role of extracellular peptidases in terminating PDF signalling at synapses. In this study we show that PDF is susceptible to hydrolysis by neprilysin, an endopeptidase that is enriched in synaptic membranes of mammals and insects. Neprilysin cleaves PDF at the internal Ser7-Leu8 peptide bond to generate PDF1-7 and PDF8-18. Neither of these fragments were able to increase intracellular cAMP levels in HEK293 cells cotransfected with the Drosophila PDF receptor cDNA and a firefly luciferase reporter gene, confirming that such cleavage results in PDF inactivation. The Ser7-Leu8 peptide bond was also the principal cleavage site when PDF was incubated with membranes prepared from heads of adult Drosophila. This endopeptidase activity was inhibited by the neprilysin inhibitors phosphoramidon (IC(50,) 0.15 micromol l(-1)) and thiorphan (IC(50,) 1.2 micromol l(-1)). We propose that cleavage by a member of the Drosophila neprilysin family of endopeptidases is the most likely mechanism for inactivating synaptic PDF and that neprilysin might have an important role in regulating PDF signals within circadian neural circuits.

  5. A lack of premature termination codon read-through efficacy of PTC124 (Ataluren in a diverse array of reporter assays.

    Directory of Open Access Journals (Sweden)

    Stuart P McElroy

    Full Text Available The drug molecule PTC124 (Ataluren has been described as a read-through agent, capable of suppressing premature termination codons (PTCs and restoring functional protein production from genes disrupted by nonsense mutations. Following the discovery of PTC124 there was some controversy regarding its mechanism of action with two reports attributing its activity to an off-target effect on the Firefly luciferase (FLuc reporter used in the development of the molecule. Despite questions remaining as to its mechanism of action, development of PTC124 continued into the clinic and it is being actively pursued as a potential nonsense mutation therapy. To thoroughly test the ability of PTC124 to read through nonsense mutations, we conducted a detailed assessment comparing the efficacy of PTC124 with the classical aminoglycoside antibiotic read-through agent geneticin (G418 across a diverse range of in vitro reporter assays. We can confirm the off-target FLuc activity of PTC124 but found that, while G418 exhibits varying activity in every read-through assay, there is no evidence of activity for PTC124.

  6. Conjugates of amino acids and peptides with 5-o-mycaminosyltylonolide and their interaction with the ribosomal exit tunnel.

    Science.gov (United States)

    Shishkina, Anna; Makarov, Gennady; Tereshchenkov, Andrey; Korshunova, Galina; Sumbatyan, Nataliya; Golovin, Andrey; Svetlov, Maxim; Bogdanov, Alexey

    2013-11-20

    During protein synthesis the nascent polypeptide chain (NC) extends through the ribosomal exit tunnel (NPET). Also, the large group of macrolide antibiotics binds in the nascent peptide exit tunnel. In some cases interaction of NC with NPET leads to the ribosome stalling, a significant event in regulation of translation. In other cases NC-ribosome interactions lead to pauses in translation that play an important role in cotranslational folding of polypeptides emerging from the ribosome. The precise mechanism of NC recognition in NPET as well as factors that determine NC conformation in the ribosomal tunnel are unknown. A number of derivatives of the macrolide antibiotic 5-O-mycaminosyltylonolide (OMT) containing N-acylated amino acid or peptide residues were synthesized in order to study potential sites of NC-NPET interactions. The target compounds were prepared by conjugation of protected amino acids and peptides with the C23 hydroxyl group of the macrolide. These OMT derivatives showed high although varying abilities to inhibit the firefly luciferase synthesis in vitro. Three glycil-containing derivatives appeared to be strong inhibitors of translation, more potent than parental OMT. Molecular dynamics (MD) simulation of complexes of tylosin, OMT, and some of OMT derivatives with the large ribosomal subunit of E. coli illuminated a plausible reason for the high inhibitory activity of Boc-Gly-OMT. In addition, the MD study detected a new putative site of interaction of the nascent polypeptide chain with the NPET walls.

  7. Non-invasive Bioluminescence Imaging of Myoblast-Mediated Hypoxia-Inducible Factor-1 Alpha Gene Transfer

    Science.gov (United States)

    Gheysens, Olivier; Chen, Ian Y.; Rodriguez-Porcel, Martin; Chan, Carmel; Rasooly, Julia; Vaerenberg, Caroline; Paulmurugan, Ramasamy; Willmann, Juergen K.; Deroose, Christophe; Wu, Joseph; Gambhir, Sanjiv S.

    2011-01-01

    Purpose We tested a novel imaging strategy, in which both the survival of transplanted myoblasts and their therapeutic transgene expression, a recombinant hypoxia-inducible factor-1α (HIF-1α-VP2), can be monitored using firefly luciferase (fluc) and Renilla luciferase (hrl) bioluminescence reporter genes, respectively. Procedures The plasmid pUbi-hrl-pUbi-HIF-1α-VP2, which expresses both hrl and HIF-1α-VP2 using two ubiquitin promoters, was characterized in vitro. C2c12 myoblasts stably expressing fluc and transiently transfected with pUbi-hrl-pUbi-HIF-1α-VP2 were injected into the mouse hindlimb. Both hrl and fluc expression were monitored using bioluminescence imaging (BLI). Results Strong correlations existed between the expression of hRL and each of HIF-1α-VP2, VEGF, and PlGF (r2>0.83, r2>0.82, and r2>0.97, respectively). In vivo, both transplanted cells and HIF-1α-VP2 transgene expression were successfully imaged using BLI. Conclusions An objective evaluation of myoblast-mediated gene transfer in living mice can be performed by monitoring both the survival and the transgene expression of transplanted myoblasts using the techniques developed herein. PMID:21267661

  8. Disruption of Arabidopsis CHY1 Reveals an Important Role of Metabolic Status in Plant Cold Stress Signaling

    Institute of Scientific and Technical Information of China (English)

    Chun-Hai Dong; Bethany K. Zolman; Bonnie Bartel; Byeong-ha Lee; Becky Stevenson; Manu Agarwal; Jian-Kang Zhu

    2009-01-01

    To study cold signaling, we screened for Arabidopsis mutants with altered cold-induced transcription of a firefly luciferase reporter gene driven by the CBF3 promoter (CBF3-LUC). One mutant, chyl-10, displayed reduced cold-induction of CBF3-LUC luminescence. RNA gel blot analysis revealed that expression of endogenous CBFs also was reduced in the chy1 mutant, chyl-10 mutant plants are more sensitive to freezing treatment than wild-type after cold acclimation. Both the wild-type and chy1 mutant plants are sensitive to darkness-induced starvation at warm temperatures, although chy1 plants are slightly more sensitive. This dark-sensitivity is suppressed by cold temperature in the wildtype but not in chy1. Constitutive CBF3 expression partially rescues the sensitivity of chy1-10 plants to dark treatment in the cold. The chy1 mutant accumulates higher levels of reactive oxygen species, and application of hydrogen peroxide can reduce cold-induction of CBF3-LUC in wild-type. Map-based cloning of the gene defective in the mutant revealed a nonsense mutation in CHY1, which encodes a peroxisomal β-hydroxyisobutyryl (HIBYL)-CoA hydrolase needed for valine catabolism and fatty acid β-oxidation. Our results suggest a role for peroxisomal metabolism in cold stress signaling, and plant tolerance to cold stress and darkness-induced starvation.

  9. A versatile ΦC31 based reporter system for measuring AP-1 and Nrf2 signaling in Drosophila and in tissue culture.

    Directory of Open Access Journals (Sweden)

    Nirmalya Chatterjee

    Full Text Available This paper describes the construction and characterization of a system of transcriptional reporter genes for monitoring the activity of signaling pathways and gene regulation mechanisms in intact Drosophila, dissected tissues or cultured cells. Transgenic integration of the reporters into the Drosophila germline was performed in a site-directed manner, using ΦC31 integrase. This strategy avoids variable position effects and assures low base level activity and high signal responsiveness. Defined integration sites furthermore enable the experimenter to compare the activity of different reporters in one organism. The reporter constructs have a modular design to facilitate the combination of promoter elements (synthetic transcription factor binding sites or natural regulatory sequences, reporter genes (eGFP, or DsRed.T4, and genomic integration sites. The system was used to analyze and compare the activity and signal response profiles of two stress inducible transcription factors, AP-1 and Nrf2. To complement the transgenic reporter fly lines, tissue culture assays were developed in which the same synthetic ARE and TRE elements control the expression of firefly luciferase.

  10. Bioluminescence-mediated longitudinal monitoring of adipose-derived stem cells in a large mammal ex vivo organ culture.

    Science.gov (United States)

    Peeters, Mirte; van Rijn, Sjoerd; Vergroesen, Pieter-Paul A; Paul, Cornelis P L; Noske, David P; Vandertop, W Peter; Wurdinger, Thomas; Helder, Marco N

    2015-09-09

    Recently, ex vivo three-dimensional organ culture systems have emerged to study the physiology and pathophysiology of human organs. These systems also have potential as a translational tool in tissue engineering; however, this potential is limited by our ability to longitudinally monitor the fate and action of cells used in regenerative therapies. Therefore, we investigated luciferase-mediated bioluminescence imaging (BLI) as a non-invasive technique to continuously monitor cellular behavior in ex vivo whole organ culture. Goat adipose-derived stem cells (gADSCs) were transduced with either Firefly luciferase (Fluc) or Gaussia luciferase (Gluc) reporter genes and injected in isolated goat intervertebral discs (IVD). Luciferase activity was monitored by BLI for at least seven days of culture. Additionally, possible confounders specific to avascular organ culture were investigated. Gluc imaging proved to be more suitable compared to Fluc in monitoring gADSCs in goat IVDs. We conclude that BLI is a promising tool to monitor spatial and temporal cellular behavior in ex vivo organ culture. Hence, ex vivo organ culture systems allow pre-screening and pre-validation of novel therapeutic concepts prior to in vivo large animal experimentation. Thereby, organ culture systems can reduce animal use, and improve the speed of innovation by overcoming technological, ethical and financial challenges.

  11. ATP as a biomarker of viable microorganisms in clean-room facilities

    Science.gov (United States)

    Venkateswaran, Kasthuri; Hattori, Noriaki; La Duc, Myron T.; Kern, Roger

    2003-01-01

    A new firefly luciferase bioluminescence assay method that differentiates free extracellular ATP (dead cells, etc.) from intracellular ATP (viable microbes) was used to determine the viable microbial cleanliness of various clean-room facilities. For comparison, samples were taken from both clean-rooms, where the air was filtered to remove particles >0.5 microm, and ordinary rooms with unfiltered air. The intracellular ATP was determined after enzymatically degrading the sample's free ATP. Also for comparison, cultivable microbial populations were counted on nutrient-rich trypticase soy agar (TSA) plates. Both the cultivable and ATP-based determinations indicate that the microbial burden was lower in clean-room facilities than in ordinary rooms. However, there was no direct correlation between the two sets of measurements because the two assays measured very different populations. A large fraction of the samples yielded no colony formers on TSA, but were positive for intracellular ATP. Subsequently, genomic DNA was isolated directly from selected samples and 16S rDNA fragments were cloned and sequenced, identifying nearest neighbors, many of which are known to be noncultivable in the media employed. It was concluded that viable microbial contamination can be reliably monitored by measurement of intracellular ATP, and that this method may be considered superior to cultivable colony counts due to its speed and its ability to report the presence of viable but noncultivable organisms. When the detection of nonviable microbes is of interest, the ATP assay can be supplemented with DNA analysis.

  12. The Application of Collaborative Business Intelligence Technology in the Hospital SPD Logistics Management Model.

    Science.gov (United States)

    Liu, Tongzhu; Shen, Aizong; Hu, Xiaojian; Tong, Guixian; Gu, Wei

    2017-06-01

    We aimed to apply collaborative business intelligence (BI) system to hospital supply, processing and distribution (SPD) logistics management model. We searched Engineering Village database, China National Knowledge Infrastructure (CNKI) and Google for articles (Published from 2011 to 2016), books, Web pages, etc., to understand SPD and BI related theories and recent research status. For the application of collaborative BI technology in the hospital SPD logistics management model, we realized this by leveraging data mining techniques to discover knowledge from complex data and collaborative techniques to improve the theories of business process. For the application of BI system, we: (i) proposed a layered structure of collaborative BI system for intelligent management in hospital logistics; (ii) built data warehouse for the collaborative BI system; (iii) improved data mining techniques such as supporting vector machines (SVM) and swarm intelligence firefly algorithm to solve key problems in hospital logistics collaborative BI system; (iv) researched the collaborative techniques oriented to data and business process optimization to improve the business processes of hospital logistics management. Proper combination of SPD model and BI system will improve the management of logistics in the hospitals. The successful implementation of the study requires: (i) to innovate and improve the traditional SPD model and make appropriate implement plans and schedules for the application of BI system according to the actual situations of hospitals; (ii) the collaborative participation of internal departments in hospital including the department of information, logistics, nursing, medical and financial; (iii) timely response of external suppliers.

  13. Enhanced recombinant protein production and differential expression of molecular chaperones in sf-caspase-1-repressed stable cells after baculovirus infection

    Directory of Open Access Journals (Sweden)

    Lai Yiu-Kay

    2012-11-01

    Full Text Available Abstract Background There are few studies that have examined the potential of RNA inference (RNAi to increase protein production in the baculovirus expression vector system (BEVS. Spodoptera frugiperda (fall armyworm (Sf-caspase-1-repressed stable cells exhibit resistance to apoptosis and enhancement of recombinant protein production. However, the mechanism of recombinant protein augmentation in baculovirus-infected Caspase-repressed insect cells has not been elucidated. Results In the current study, we utilized RNAi-mediated Sf-caspase-1-repressed stable cells to clarify how the resistance to apoptosis can enhance both intracellular (firefly luciferase and extracellular (secreted alkaline phosphatase [SEAP] recombinant protein production in BEVS. Since the expression of molecular chaperones is strongly associated with the maximal production of exogenous proteins in BEVS, the differential expression of molecular chaperones in baculovirus-infected stable cells was also analyzed in this study. Conclusion The data indicated that the retention of expression of molecular chaperones in baculovirus-infected Sf-caspase-1-repressed stable cells give the higher recombinant protein accumulation.

  14. Continuous, real-time bioimaging of chemical bioavailability and toxicology using autonomously bioluminescent human cell lines

    Science.gov (United States)

    Xu, Tingting; Close, Dan M.; Webb, James D.; Price, Sarah L.; Ripp, Steven A.; Sayler, Gary S.

    2015-01-01

    Bioluminescent imaging is an emerging biomedical surveillance strategy that uses external cameras to detect in vivo light generated in small animal models of human physiology or in vitro light generated in tissue culture or tissue scaffold mimics of human anatomy. The most widely utilized of reporters is the firefly luciferase (luc) gene; however, it generates light only upon addition of a chemical substrate, thus only generating intermittent single time point data snapshots. To overcome this disadvantage, we have demonstrated substrate-independent bioluminescent imaging using an optimized bacterial bioluminescence (lux) system. The lux reporter produces bioluminescence autonomously using components found naturally within the cell, thereby allowing imaging to occur continuously and in real-time over the lifetime of the host. We have validated this technology in human cells with demonstrated chemical toxicological profiling against exotoxin exposures at signal strengths comparable to existing luc systems (~1.33 × 107 photons/second). As a proof-in-principle demonstration, we have engineered breast carcinoma cells to express bioluminescence for real-time screening of endocrine disrupting chemicals and validated detection of 17β-estradiol (EC50 = ~ 10 pM). These and other applications of this new reporter technology will be discussed as potential new pathways towards improved models of target chemical bioavailability, toxicology, efficacy, and human safety. PMID:26516295

  15. Autonomously Bioluminescent Mammalian Cells for Continuous and Real-time Monitoring of Cytotoxicity

    Science.gov (United States)

    Xu, Tingting; Close, Dan M.; Webb, James D.; Ripp, Steven A.; Sayler, Gary S.

    2013-01-01

    Mammalian cell-based in vitro assays have been widely employed as alternatives to animal testing for toxicological studies but have been limited due to the high monetary and time costs of parallel sample preparation that are necessitated due to the destructive nature of firefly luciferase-based screening methods. This video describes the utilization of autonomously bioluminescent mammalian cells, which do not require the destructive addition of a luciferin substrate, as an inexpensive and facile method for monitoring the cytotoxic effects of a compound of interest. Mammalian cells stably expressing the full bacterial bioluminescence (luxCDABEfrp) gene cassette autonomously produce an optical signal that peaks at 490 nm without the addition of an expensive and possibly interfering luciferin substrate, excitation by an external energy source, or destruction of the sample that is traditionally performed during optical imaging procedures. This independence from external stimulation places the burden for maintaining the bioluminescent reaction solely on the cell, meaning that the resultant signal is only detected during active metabolism. This characteristic makes the lux-expressing cell line an excellent candidate for use as a biosentinel against cytotoxic effects because changes in bioluminescent production are indicative of adverse effects on cellular growth and metabolism. Similarly, the autonomous nature and lack of required sample destruction permits repeated imaging of the same sample in real-time throughout the period of toxicant exposure and can be performed across multiple samples using existing imaging equipment in an automated fashion. PMID:24193545

  16. Development of bioluminescent chick chorioallantoic membrane (CAM) models for primary pancreatic cancer cells: a platform for drug testing

    Science.gov (United States)

    Rovithi, Maria; Avan, Amir; Funel, Niccola; Leon, Leticia G.; Gomez, Valentina E.; Wurdinger, Thomas; Griffioen, Arjan W.; Verheul, Henk M. W.; Giovannetti, Elisa

    2017-01-01

    The aim of the present study was to develop chick-embryo chorioallantoic membrane (CAM) bioluminescent tumor models employing low passage cell cultures obtained from primary pancreatic ductal adenocarcinoma (PDAC) cells. Primary PDAC cells transduced with lentivirus expressing Firefly-luciferase (Fluc) were established and inoculated onto the CAM membrane, with >80% engraftment. Fluc signal reliably correlated with tumor growth. Tumor features were evaluated by immunohistochemistry and genetic analyses, including analysis of mutations and mRNA expression of PDAC pivotal genes, as well as microRNA (miRNA) profiling. These studies showed that CAM tumors had histopathological and genetic characteristic comparable to the original tumors. We subsequently tested the modulation of key miRNAs and the activity of gemcitabine and crizotinib on CAM tumors, showing that combination treatment resulted in 63% inhibition of tumor growth as compared to control (p < 0.01). These results were associated with reduced expression of miR-21 and increased expression of miR-155. Our study provides the first evidence that transduced primary PDAC cells can form tumors on the CAM, retaining several histopathological and (epi)genetic characteristics of original tumors. Moreover, our results support the use of these models for drug testing, providing insights on molecular mechanisms underlying antitumor activity of new drugs/combinations. PMID:28304379

  17. A bioluminescence reporter mouse that monitors expression of constitutively active β-catenin

    Science.gov (United States)

    Kommagani, Ramakrishna; Peavey, Mary C.; Hai, Lan; Lonard, David M.; Lydon, John P.

    2017-01-01

    This short technical report describes the generation and characterization of a bioluminescence reporter mouse that is engineered to detect and longitudinally monitor the expression of doxycycline-induced constitutively active β-catenin. The new responder transgenic mouse contains the TetO-ΔN89β-CatTMILA transgene, which consists of the tet-operator followed by a bicistronic sequence encoding a stabilized form of active β-catenin (ΔN89β-catenin), an internal ribosome entry site, and the firefly luciferase gene. To confirm that the transgene operates as designed, TetO-ΔN89β-CatTMILA transgenic mouse lines were crossed with an effector mouse that harbors the mouse mammary tumor virus-reverse tetracycline transactivator (MMTV-rtTA) transgene (termed MTB hereon), which primarily targets rtTA expression to the mammary epithelium. Following doxycycline administration, the resultant MTB/CatTMILA bigenic reporter exhibited precocious lobuloalveologenesis, ductal hyperplasia, and mammary adenocarcinomas, which were visualized and monitored by in vivo bioluminescence detection. Therefore, we predict that the TetO-ΔN89β-CatTMILA transgenic responder mouse—when crossed with the appropriate effector transgenic—will have wide-applicability to non-invasively monitor the influence of constitutively active β-catenin expression on cell-fate specification, proliferation, differentiation, and neoplastic transformation in a broad spectrum of target tissues. PMID:28253313

  18. Ex vivo intracoronary gene transfer of adeno-associated virus 2 leads to superior transduction over serotypes 8 and 9 in rat heart transplants.

    Science.gov (United States)

    Raissadati, Alireza; Jokinen, Janne J; Syrjälä, Simo O; Keränen, Mikko A I; Krebs, Rainer; Tuuminen, Raimo; Arnaudova, Ralica; Rouvinen, Eeva; Anisimov, Andrey; Soronen, Jarkko; Pajusola, Katri; Alitalo, Kari; Nykänen, Antti I; Lemström, Karl

    2013-11-01

    Heart transplant gene therapy requires vectors with long-lasting gene expression, high cardiotropism, and minimal pathological effects. Here, we examined transduction properties of ex vivo intracoronary delivery of adeno-associated virus (AAV) serotype 2, 8, and 9 in rat syngenic and allogenic heart transplants. Adult Dark Agouti (DA) rat hearts were intracoronarily perfused ex vivo with AAV2, AAV8, or AAV9 encoding firefly luciferase and transplanted heterotopically into the abdomen of syngenic DA or allogenic Wistar-Furth (WF) recipients. Serial in vivo bioluminescent imaging of syngraft and allograft recipients was performed for 6 months and 4 weeks, respectively. Grafts were removed for PCR-, RT-PCR, and luminometer analysis. In vivo bioluminescent imaging of recipients showed that AAV9 induced a prominent and stable luciferase activity in the abdomen, when compared with AAV2 and AAV8. However, ex vivo analyses revealed that intracoronary perfusion with AAV2 resulted in the highest heart transplant transduction levels in syngrafts and allografts. Ex vivo intracoronary delivery of AAV2 resulted in efficient transgene expression in heart transplants, whereas intracoronary AAV9 escapes into adjacent tissues. In terms of cardiac transduction, these results suggest AAV2 as a potential vector for gene therapy in preclinical heart transplants studies, and highlight the importance of delivery route in gene transfer studies.

  19. Lights on for HIF-1α: genetically enhanced mouse cardiomyocytes for heart tissue imaging.

    Science.gov (United States)

    Hesse, Amke R; Levent, Elif; Zieseniss, Anke; Tiburcy, Malte; Zimmermann, Wolfram H; Katschinski, Dörthe M

    2014-01-01

    The hypoxia inducible factor-1 (HIF-1) is a suitable marker for tissue oxygenation. We intended to develop cardiomyocytes (CMs) expressing the oxygen-dependent degradation domain of HIF-1α fused to the firefly luciferase (ODD-Luc) followed by proof-of-concept for its applicability in the assessment of heart muscle oxygenation. We first generated embryonic stem cell (ESC) lines (ODD-Luc ESCs) from a Tg ROSA26 ODD-Luc/+ mouse. Subsequent CMs selection was facilitated by stable integration of an antibiotic resistance expressed under the control of the αMHC promoter. ODD-Luc ESCs showed a strong Luc-signal within 1 h of hypoxia (1% oxygen), which coincided with endogenous HIF-1α. Engineered heart muscle (EHM) constructed with ODD-Luc CMs confirmed the utility of the model to sense hypoxia, and monitor reoxygenation also in a multicellular heart muscle model. Pharmacologically induced inotropy/chronotropy under isoprenaline resulted in enhanced Luc-signal suggesting enhanced oxygen consumption, leading to notable myocardial hypoxia. ODD-Luc-CMs can be used to monitor dynamic changes of cardiomyocyte oxygenation in living heart muscle samples. We provide proof-of-concept for pharmacologically induced myocardial interventions and envision applications of the developed model in drug screens and fundamental studies of ischemia/reperfusion injury. © 2014 S. Karger AG, Basel.

  20. Lights on for HIF-1α: Genetically Enhanced Mouse Cardiomyocytes for Heart Tissue Imaging

    Directory of Open Access Journals (Sweden)

    Amke R. Hesse

    2014-07-01

    Full Text Available Background/Aims: The hypoxia inducible factor-1 (HIF-1 is a suitable marker for tissue oxygenation. We intended to develop cardiomyocytes (CMs expressing the oxygen-dependent degradation domain of HIF-1α fused to the firefly luciferase (ODD-Luc followed by proof-of-concept for its applicability in the assessment of heart muscle oxygenation. Methods and Results: We first generated embryonic stem cell (ESC lines (ODD-Luc ESCs from a Tg ROSA26 ODD-Luc/+ mouse. Subsequent CMs selection was facilitated by stable integration of an antibiotic resistance expressed under the control of the αMHC promoter. ODD-Luc ESCs showed a strong Luc-signal within 1 h of hypoxia (1% oxygen, which coincided with endogenous HIF-1α. Engineered heart muscle (EHM constructed with ODD-Luc CMs confirmed the utility of the model to sense hypoxia, and monitor reoxygenation also in a multicellular heart muscle model. Pharmacologically induced inotropy/chronotropy under isoprenaline resulted in enhanced Luc-signal suggesting enhanced oxygen consumption, leading to notable myocardial hypoxia. Conclusions: ODD-Luc-CMs can be used to monitor dynamic changes of cardiomyocyte oxygenation in living heart muscle samples. We provide proof-of-concept for pharmacologically induced myocardial interventions and envision applications of the developed model in drug screens and fundamental studies of ischemia/reperfusion injury.

  1. 猪瘟病毒对IFN-β启动子活化%The activation of IFN-β promoter mediated by classical swine fever virus

    Institute of Scientific and Technical Information of China (English)

    夏燕华; 赵天生

    2012-01-01

    Classical swine fever virus can persistently infect swine for its ability to escape the killing of immune system. In order to prove it,Newcastle disease virus as IFN inducer,firefly luciferase reporter system was used to test the effect on interferon-beta promoter induced by CSFV Shimen strain. Results demonstrate that CSFV can't induce IFN-βpromoter but can obviously inhibit the NDV-mediated-activation, which prove that CSFV escape from the killing of immune system by inhibiting IFN production. The research partly explains why CSFV can establish persistent infection in swine.%猪瘟病毒(Classical swine fever virus,CSFV)之所以能在猪体中建立持续感染,与其逃避宿主的免疫清除有关,据此,本课题以新城疫病毒(Newcastle disease virus,NDV)作为诱导剂,利用荧光素酶报告基因系统测定了CSFV Shimen株对IFN-β启动子活化的影响.结果表明CSFV不仅不能活化IFN-β启动子,而且能明显抑制NDV对IFN-β启动子的活化作用,说明CSFV可通过抑制IFN产生来逃避机体的免疫清除,为病毒建立持续性感染创造条件.

  2. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Tana A. Omokoko

    2016-01-01

    Full Text Available Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard 51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the 51Cr release and further confirmed the assay’s ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay’s combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies.

  3. A SURVEY ON THE ALGORITHMIC APPROACH USED IN ROUTING FOR PLACEMENT AND ROUTING FLOW

    Directory of Open Access Journals (Sweden)

    KOMAL

    2014-06-01

    Full Text Available Routing is one of the long-drawn-out processes after placement in VLSI design. The routing provides the path for nets on chip to interconnect the pins on the pads or blocks at the chip boundary. This paper provides a systematic insight of interconnect of nets in ‘Placement and Routing Flow’ based on various methods (global routing and detailed routing. Further, the work reported so far has been compared with a multiple techniques for multiple factors such as reduction in wire-length, short execution time, fast and accurate congestion, improvement in complexity, signal integrity and crosstalk. Here the methodologies adopts are the Routing congestion estimator algorithm, Ant Colony Optimization. Firefly Algorithm, Monotonic Staircase Routing and so on. It is also observed that Pattern Based Routing is much faster than the Maze Routing, and the improved parameters are there is no over-congestion and 100% routablity with Monotonic Staircase Channels. zero overflow by Simulated-Evolution(Sim-E, and Complexity improved by a Fuzzified Approach Towards Global Routing.

  4. The Fibonacci Life-Chart Method (FLCM) as a foundation for Carl Jung's theory of synchronicity.

    Science.gov (United States)

    Sacco, Robert G

    2016-04-01

    Since the scientific method requires events to be subject to controlled examination it would seem that synchronicities are not scientifically investigable. Jung speculated that because these incredible events are like the random sparks of a firefly they cannot be pinned down. However, doubting Jung's doubts, the author provides a possible method of elucidating these seemingly random and elusive events. The author draws on a new method, designated the Fibonacci Life-Chart Method (FLCM), which categorizes phase transitions and Phi fractal scaling in human development based on the occurrence of Fibonacci numbers in biological cell division and self-organizing systems. The FLCM offers an orientation towards psychological experience that may have relevance to Jung's theory of synchronicity in which connections are deemed to be intrinsically meaningful rather than demonstrable consequences of cause and effect. In such a model synchronistic events can be seen to be, as the self-organizing system enlarges, manifestations of self-organized critical moments and Phi fractal scaling. Recommendations for future studies include testing the results of the FLCM using case reports of synchronistic and spiritual experiences. © 2016, The Society of Analytical Psychology.

  5. A New Hybrid Model Based on Data Preprocessing and an Intelligent Optimization Algorithm for Electrical Power System Forecasting

    Directory of Open Access Journals (Sweden)

    Ping Jiang

    2015-01-01

    Full Text Available The establishment of electrical power system cannot only benefit the reasonable distribution and management in energy resources, but also satisfy the increasing demand for electricity. The electrical power system construction is often a pivotal part in the national and regional economic development plan. This paper constructs a hybrid model, known as the E-MFA-BP model, that can forecast indices in the electrical power system, including wind speed, electrical load, and electricity price. Firstly, the ensemble empirical mode decomposition can be applied to eliminate the noise of original time series data. After data preprocessing, the back propagation neural network model is applied to carry out the forecasting. Owing to the instability of its structure, the modified firefly algorithm is employed to optimize the weight and threshold values of back propagation to obtain a hybrid model with higher forecasting quality. Three experiments are carried out to verify the effectiveness of the model. Through comparison with other traditional well-known forecasting models, and models optimized by other optimization algorithms, the experimental results demonstrate that the hybrid model has the best forecasting performance.

  6. Recombinant receptor/reporter gene bioassays for assessing the estrogenic and dioxin-like activities of xenobiotics and complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zacharewski, T. [Univ. of Western Ontario, London, Ontario (Canada). Dept. of Pharmacology and Toxicology

    1995-12-31

    Exposure to naturally occurring or synthetic substances that possess sex steroid and/or dioxin-like activity may have long range effects on human health, reproductive fitness and environmental quality. Results from recent epidemiological studies have suggested that xenobiotics with sex steroid activity may contribute to the development of hormone-dependent cancers and disorders in the male reproductive tract as well as attenuate sperm production. However, most of these compounds, which are referred to as endocrine disruptors, are structurally dissimilar to sex steroids. Yet, based upon ambiguous assays, it has been conceded that the effects of these compounds are mediated by receptors. The authors have taken advantage of the mechanism of action of these compounds to develop recombinant receptor/reporter gene bioassays for environmental estrogens and dioxin-like compounds. The assays use an easily measurable enzyme activity (i.e. firefly luciferase), exhibit improved sensitivity and selectivity and are amenable to automation. Data will be presented demonstrating that phytoestrogens (e.g. genistein) and xenobiotics such as pesticides (e.g. DDT, Kepone), nonionic surfactants (e.g. p-nonylphenol), and precursors used in the manufacture of plastics (e.g. Bisphenol A) exhibit estrogenic activity. In addition, the assays have been used to detect estrogenic and dioxin-like activity in complex mixtures such as pulp and paper mill black liquor and effluent. These results demonstrate the utility of recombinant receptor/reporter gene bioassays for identifying substances or complex mixtures with estrogenic and/or dioxin-like activity.

  7. Development of Endothelial-Specific Single Inducible Lentiviral Vectors for Genetic Engineering of Endothelial Progenitor Cells.

    Science.gov (United States)

    Yang, Guanghua; Kramer, M Gabriela; Fernandez-Ruiz, Veronica; Kawa, Milosz P; Huang, Xin; Liu, Zhongmin; Prieto, Jesus; Qian, Cheng

    2015-11-27

    Endothelial progenitor cells (EPC) are able to migrate to tumor vasculature. These cells, if genetically modified, can be used as vehicles to deliver toxic material to, or express anticancer proteins in tumor. To test this hypothesis, we developed several single, endothelial-specific, and doxycycline-inducible self-inactivating (SIN) lentiviral vectors. Two distinct expression cassettes were inserted into a SIN-vector: one controlled by an endothelial lineage-specific, murine vascular endothelial cadherin (mVEcad) promoter for the expression of a transactivator, rtTA2S-M2; and the other driven by an inducible promoter, TREalb, for a firefly luciferase reporter gene. We compared the expression levels of luciferase in different vector constructs, containing either the same or opposite orientation with respect to the vector sequence. The results showed that the vector with these two expression cassettes placed in opposite directions was optimal, characterized by a robust induction of the transgene expression (17.7- to 73-fold) in the presence of doxycycline in several endothelial cell lines, but without leakiness when uninduced. In conclusion, an endothelial lineage-specific single inducible SIN lentiviral vector has been developed. Such a lentiviral vector can be used to endow endothelial progenitor cells with anti-tumor properties.

  8. Travelling Wave Pulse Coupled Oscillator (TWPCO) Using a Self-Organizing Scheme for Energy-Efficient Wireless Sensor Networks

    Science.gov (United States)

    Hanapi, Zurina Mohd; Othman, Mohamed; Zukarnain, Zuriati Ahmad

    2017-01-01

    Recently, Pulse Coupled Oscillator (PCO)-based travelling waves have attracted substantial attention by researchers in wireless sensor network (WSN) synchronization. Because WSNs are generally artificial occurrences that mimic natural phenomena, the PCO utilizes firefly synchronization of attracting mating partners for modelling the WSN. However, given that sensor nodes are unable to receive messages while transmitting data packets (due to deafness), the PCO model may not be efficient for sensor network modelling. To overcome this limitation, this paper proposed a new scheme called the Travelling Wave Pulse Coupled Oscillator (TWPCO). For this, the study used a self-organizing scheme for energy-efficient WSNs that adopted travelling wave biologically inspired network systems based on phase locking of the PCO model to counteract deafness. From the simulation, it was found that the proposed TWPCO scheme attained a steady state after a number of cycles. It also showed superior performance compared to other mechanisms, with a reduction in the total energy consumption of 25%. The results showed that the performance improved by 13% in terms of data gathering. Based on the results, the proposed scheme avoids the deafness that occurs in the transmit state in WSNs and increases the data collection throughout the transmission states in WSNs. PMID:28056020

  9. An autoinhibited coiled-coil design strategy for split-protein protease sensors.

    Science.gov (United States)

    Shekhawat, Sujan S; Porter, Jason R; Sriprasad, Akshay; Ghosh, Indraneel

    2009-10-28

    Proteases are widely studied as they are integral players in cell-cycle control and apoptosis. We report a new approach for the design of a family of genetically encoded turn-on protease biosensors. In our design, an autoinhibited coiled-coil switch is turned on upon proteolytic cleavage, which results in the complementation of split-protein reporters. Utilizing this new autoinhibition design paradigm, we present the rational construction and optimization of three generations of protease biosensors, with the final design providing a 1000-fold increase in bioluminescent signal upon addition of the TEV protease. We demonstrate the generality of the approach utilizing two different split-protein reporters, firefly luciferase and beta-lactamase, while also testing our design in the context of a therapeutically relevant protease, caspase-3. Finally, we present a dual protease sensor geometry that allows for the use of these turn-on sensors as potential AND logic gates. Thus, these studies potentially provide a new method for the design and implementation of genetically encoded turn-on protease sensors while also providing a general autoinhibited coiled-coil strategy for controlling the activity of fragmented proteins.

  10. Factors Influencing Quantification of in Vivo Bioluminescence Imaging: Application to Assessment of Pancreatic Islet Transplants

    Directory of Open Access Journals (Sweden)

    John Virostko

    2004-10-01

    Full Text Available The aim of this study is to determine and characterize factors influencing in vivo bioluminescence imaging (BLI and apply them to the specific application of imaging transplanted pancreatic islets. Noninvasive quantitative assessment of transplanted pancreatic islets poses a formidable challenge. Murine pancreatic islets expressing firefly luciferase were transplanted under the renal capsule or into the portal vein of nonobese diabetic–severe combined immunodeficiency mice and the bioluminescence was quantified with a cooled charge coupled device camera and digital photon image analysis. The important, but often neglected, effects of wound healing, mouse positioning, and transplantation site on bioluminescence measurements were investigated by imaging a constant emission, isotropic light-emitting bead (λ = 600 implanted at the renal or hepatic site. The renal beads emitted nearly four times more light than hepatic beads with a smaller spot size, indicating that light absorption and scatter are greatly influenced by the transplant site and must be accounted for in BLI measurements. Detected luminescence decreased with increasing angle between the mouse surface normal and optical axis. By defining imaging parameters such as postsurgical effects, animal positioning, and light attenuation as a function of transplant site, this study develops BLI as a useful imaging modality for quantitative assessment of islets post-transplantation.

  11. Nanowire Photovoltaic Devices

    Science.gov (United States)

    Forbes, David

    2015-01-01

    Firefly Technologies, in collaboration with the Rochester Institute of Technology and the University of Wisconsin-Madison, developed synthesis methods for highly strained nanowires. Two synthesis routes resulted in successful nanowire epitaxy: direct nucleation and growth on the substrate and a novel selective-epitaxy route based on nanolithography using diblock copolymers. The indium-arsenide (InAs) nanowires are implemented in situ within the epitaxy environment-a significant innovation relative to conventional semiconductor nanowire generation using ex situ gold nanoparticles. The introduction of these nanoscale features may enable an intermediate band solar cell while simultaneously increasing the effective absorption volume that can otherwise limit short-circuit current generated by thin quantized layers. The use of nanowires for photovoltaics decouples the absorption process from the current extraction process by virtue of the high aspect ratio. While no functional solar cells resulted from this effort, considerable fundamental understanding of the nanowire epitaxy kinetics and nanopatterning process was developed. This approach could, in principle, be an enabling technology for heterointegration of dissimilar materials. The technology also is applicable to virtual substrates. Incorporating nanowires onto a recrystallized germanium/metal foil substrate would potentially solve the problem of grain boundary shunting of generated carriers by restricting the cross-sectional area of the nanowire (tens of nanometers in diameter) to sizes smaller than the recrystallized grains (0.5 to 1 micron(exp 2).

  12. Chebyshev polynomial functions based locally recurrent neuro-fuzzy information system for prediction of financial and energy market data

    Directory of Open Access Journals (Sweden)

    A.K. Parida

    2016-09-01

    Full Text Available In this paper Chebyshev polynomial functions based locally recurrent neuro-fuzzy information system is presented for the prediction and analysis of financial and electrical energy market data. The normally used TSK-type feedforward fuzzy neural network is unable to take the full advantage of the use of the linear fuzzy rule base in accurate input–output mapping and hence the consequent part of the rule base is made nonlinear using polynomial or arithmetic basis functions. Further the Chebyshev polynomial functions provide an expanded nonlinear transformation to the input space thereby increasing its dimension for capturing the nonlinearities and chaotic variations in financial or energy market data streams. Also the locally recurrent neuro-fuzzy information system (LRNFIS includes feedback loops both at the firing strength layer and the output layer to allow signal flow both in forward and backward directions, thereby making the LRNFIS mimic a dynamic system that provides fast convergence and accuracy in predicting time series fluctuations. Instead of using forward and backward least mean square (FBLMS learning algorithm, an improved Firefly-Harmony search (IFFHS learning algorithm is used to estimate the parameters of the consequent part and feedback loop parameters for better stability and convergence. Several real world financial and energy market time series databases are used for performance validation of the proposed LRNFIS model.

  13. Theoretical modeling of the spectroscopic absorption properties of luciferin and oxyluciferin: A critical comparison with recent experimental studies

    Energy Technology Data Exchange (ETDEWEB)

    Anselmi, Massimiliano, E-mail: m.anselmi@caspur.it [Department of Chemistry, University of Rome ' La Sapienza' , P.le Aldo Moro 5, 00185 Rome (Italy); Marocchi, Simone [Department of Chemistry, University of Rome ' La Sapienza' , P.le Aldo Moro 5, 00185 Rome (Italy); Aschi, Massimiliano [Department of Chemistry, Chemical Engineering and Materials, University of L' Aquila, Via Vetoio (Coppito 1), 67100 Coppito, L' Aquila (Italy); Amadei, Andrea [Department of Chemistry, University of Rome ' Tor Vergata' , Via della Ricerca Scientifica 1, 00133 Rome (Italy)

    2012-01-02

    Highlights: Black-Right-Pointing-Pointer The calculated absorption spectra were compared with experimental data. Black-Right-Pointing-Pointer Shapes and absorption maxima were reproduced for luciferin and oxyluciferin spectra. Black-Right-Pointing-Pointer The effect of the solvent largely changes the electronic transition probabilities. Black-Right-Pointing-Pointer Higher excitations provide an important contribution to the main absorption peak. - Abstract: Firefly luciferin and its oxidated form, oxyluciferin, are two heterocyclic compounds involved in the enzymatic reaction, catalyzed by redox proteins called luciferases, which provides the bioluminescence in a wide group of arthropods. Whereas the electronic absorption spectra of D-luciferin in water at different pHs are known since 1960s, only recently reliable experimental electronic spectra of oxyluciferin have become available. In addition oxyluciferin is involved in a triple chemical equilibria (deprotonation of the two hydroxyl groups and keto-enol tautomerism of the 4-hydroxythiazole ring), that obligates to select during an experiment a predominant species, tuning pH or solvent polarity besides introducing chemical modifications. In this study we report the absorption spectra of luciferin and oxyluciferin in each principal chemical form, calculated by means of perturbed matrix method (PMM), which allowed us to successfully introduce the effect of the solvent on the spectroscopic absorption properties, and compare the result with available experimental data.

  14. Frequency and character of alternative somatic recombination fates of paralogous genes during T-DNA integration.

    Science.gov (United States)

    Jelesko, John G; Carter, Kristy; Kinoshita, Yuki; Gruissem, Wilhelm

    2005-09-01

    A synthetic RBCSB gene cluster was transformed into Arabidopsis in order to simultaneously evaluate the frequency and character of somatic illegitimate recombination, homologous recombination, and targeted gene replacement events associated with T-DNA-mediated transformation. The most frequent type of recombination event observed was illegitimate integration of the T-DNA without activation of the silent DeltaRBCS1B: LUC transgene. Sixteen luc(+) (firefly luciferase positive) T1 plants were isolated. Six of these were due to illegitimate recombination events resulting in a gene trapping effect. Nine resulted from homologous recombination between paralogous RBCSB sequences associated with T-DNA integration. The frequency of somatic homologous recombination associated with T-DNA integration was almost 200 times higher than previously reported rates of meiotic homologous recombination with the same genes. The distribution of (somatic homologous) recombination resolution sites generally fits a fractional interval length model. However, a small region adjacent to an indel showed a significant over-representation of resolution sites, suggesting that DNA mismatch recognition may also play an important role in the positioning of somatic resolution sites. The frequency of somatic resolution within exon-2 was significantly different from that previously observed during meiotic recombination.

  15. Evaluation of impaired beta-cell function in nonobese-diabetic (NOD) mouse model using bioluminescence imaging.

    Science.gov (United States)

    Sever, Dror; Eldor, Roy; Sadoun, Gadi; Amior, Livnat; Dubois, Daniele; Boitard, Christian; Aflalo, Claude; Melloul, Danielle

    2011-02-01

    Insulin-producing pancreatic β cells are functionally impaired or destroyed in diabetes mellitus. The onset of type 1 diabetes (T1D) represents the culmination of a prolonged prediabetic phase of immune-mediated β-cell destruction. To assess the in vivo metabolic status of these cells, we used the ATP-sensitive firefly luciferase bioluminescence imaging approach, as a noninvasive probe to monitor pathological alterations in β-cell function in the nonobese-diabetic (NOD) mouse model of T1D. Hence, we generated the ToIβ-NOD transgenic mice in which doxycycline-inducible luciferase gene is selectively expressed in β cells. A sharp reduction in bioluminescence emitted in vivo from β cells at the early stages, preceded by several weeks of a limited reduction in β-cell mass. Since this decline could be due to the ongoing inflammatory process occurring in vivo, we exposed control islets to inflammatory cytokines and observed a dramatic decrease in luciferase luminescence, which appears to be due in part to a decrease in protein levels and a drop in intracellular ATP levels. This is the first evidence that selective expression of the luciferase gene represents a sensitive method for noninvasive in vivo monitoring of early β-cell dysfunction, subtle metabolic changes, such as endogenous ATP levels, indicative of a pathological condition in a tissue at the cellular level.

  16. Biomarkers for monitoring efficacy of bioremediation by microbial inoculants

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, J.K.; Elvang, A.M. [Stockholm University (Sweden). Arrhenius Laboratories for Natural Sciences; Bjorklof, K.; Jorgensen, K.S. [Finnish Environment Institute, Helsinki (Finland). Research Laboratory

    2000-07-01

    Bioaugmentation of contaminated sites with microbes that are adapted or genetically engineered for degradation of specific toxic compounds is an area that is currently being explored as a clean-up option. Biomarkers have been developed to track the survival and efficacy of specific bacteria that are used as inocula for bioremediation of contaminated soil. Examples of biomarkers include the Iuc gene, encoding firefly luciferase and the gfp gene, encoding the green fluorescent protein (GFP). The luc gene was used to tag different bacteria used for bioremediation of gasoline or chlorophenols. The bacteria were monitored on the basis of luciferase activity in cell extracts from soil. The gfp gene was also used to monitor bacteria during degradation of chlorophenol in soil, based on fluorescence of the GFP protein. Other biomarkers can also be used for monitoring of microbial inocula used for bioaugmentation of contaminated sites. The choice of biomarker and monitoring system depends on the particular site, bacterial strain and sensitivity and specificity of detection required. (author)

  17. Allosteric regulation of phosphofructokinase controls the emergence of glycolytic oscillations in isolated yeast cells.

    Science.gov (United States)

    Gustavsson, Anna-Karin; van Niekerk, David D; Adiels, Caroline B; Kooi, Bob; Goksör, Mattias; Snoep, Jacky L

    2014-06-01

    Oscillations are widely distributed in nature and synchronization of oscillators has been described at the cellular level (e.g. heart cells) and at the population level (e.g. fireflies). Yeast glycolysis is the best known oscillatory system, although it has been studied almost exclusively at the population level (i.e. limited to observations of average behaviour in synchronized cultures). We studied individual yeast cells that were positioned with optical tweezers in a microfluidic chamber to determine the precise conditions for autonomous glycolytic oscillations. Hopf bifurcation points were determined experimentally in individual cells as a function of glucose and cyanide concentrations. The experiments were analyzed in a detailed mathematical model and could be interpreted in terms of an oscillatory manifold in a three-dimensional state-space; crossing the boundaries of the manifold coincides with the onset of oscillations and positioning along the longitudinal axis of the volume sets the period. The oscillatory manifold could be approximated by allosteric control values of phosphofructokinase for ATP and AMP. The mathematical models described here have been submitted to the JWS Online Cellular Systems Modelling Database and can be accessed at http://jjj.mib.ac.uk/webMathematica/UItester.jsp?modelName=gustavsson5. [Database section added 14 May 2014 after original online publication]. © 2014 FEBS.

  18. Safe and Objective Assay of Enterovirus 71 Neutralizing Antibodies via Pseudovirus

    Institute of Scientific and Technical Information of China (English)

    JIN Jun; XU Lin; GUO Shi-jie; SUN Shi-yang; ZHANG Shu; ZHU Chang-lin; KONG Wei; JIANG Chun-lai

    2012-01-01

    Current serum neutralization assays based on the inhibition of the eytopathic effect(Nt-CPE) need to manipulate live viruses,which are time-consuming,labor-intensive,and have the potential exposure to infectious agents,so a safe and objective assay via pseudovirus for the fast and efficient detection of enterovirus 71(EV71 ) neutralizing antibodies was developed.First,we generated EV71 pseudovirus containing firefly luciferase gene in place of the capsid gene P1 in EV71 genome.Vero cells infected with 200 CCID50(50% cell culture infective dose) of EV71 pseudovirus for 24 h were found to have the best performance.Seval sera were measured by EV71 pseudoparticle neutralization assay(Nt-PPN) and the conventional serological method Nt-CPE.Neutralizing antibody titers measured by Nt-PPN and those obtained by Nt-CPE demonstrate a high correlation between the two methods.Overall,the PPN assay represents a valid alternative to conventional serological methods for the evaluation of EV71 neutralizing antibodies.This method can be used for detecting neutralizing antibodies of other picornaviruses,such as hepatitis A virus(HAV) and coxsackievirus 16(CVA16),and make it possible to determine whether there is cross-reactivity between EV71 and CVA16.

  19. ATP as a biomarker of viable microorganisms in clean-room facilities

    Science.gov (United States)

    Venkateswaran, Kasthuri; Hattori, Noriaki; La Duc, Myron T.; Kern, Roger

    2003-01-01

    A new firefly luciferase bioluminescence assay method that differentiates free extracellular ATP (dead cells, etc.) from intracellular ATP (viable microbes) was used to determine the viable microbial cleanliness of various clean-room facilities. For comparison, samples were taken from both clean-rooms, where the air was filtered to remove particles >0.5 microm, and ordinary rooms with unfiltered air. The intracellular ATP was determined after enzymatically degrading the sample's free ATP. Also for comparison, cultivable microbial populations were counted on nutrient-rich trypticase soy agar (TSA) plates. Both the cultivable and ATP-based determinations indicate that the microbial burden was lower in clean-room facilities than in ordinary rooms. However, there was no direct correlation between the two sets of measurements because the two assays measured very different populations. A large fraction of the samples yielded no colony formers on TSA, but were positive for intracellular ATP. Subsequently, genomic DNA was isolated directly from selected samples and 16S rDNA fragments were cloned and sequenced, identifying nearest neighbors, many of which are known to be noncultivable in the media employed. It was concluded that viable microbial contamination can be reliably monitored by measurement of intracellular ATP, and that this method may be considered superior to cultivable colony counts due to its speed and its ability to report the presence of viable but noncultivable organisms. When the detection of nonviable microbes is of interest, the ATP assay can be supplemented with DNA analysis.

  20. Validation of an interferon stimulatory response element reporter gene assay for quantifying type I interferons.

    Science.gov (United States)

    McCoski, S R; Xie, M; Hall, E B; Mercadante, P M; Spencer, T E; Lonergan, P; Ealy, A D

    2014-04-01

    The goal of this work was to develop a virus-free, cell-based interferon (IFN) bioassay and determine the utility of this assay on biological samples that contained IFN-τ, the trophoblast-secreted maternal recognition of pregnancy factor in ruminants. Madin-Darby bovine kidney cells were transduced with lentiviral particles that contained a firefly luciferase reporter construct driven by an IFN stimulatory response element (ISRE). Stably transduced cells were selected with the use of puromycin resistance. A linear, dose-responsive response was detected with human IFN-α and ovine IFN-τ. Interferon activity was detected in conditioned media from bovine trophoblast cells and uterine flushes collected from sheep and cattle. Activity also was detected in media collected after individual or small group culture of in vitro-produced bovine blastocysts at day 8 to 10 after fertilization. In summary, this IFN stimulatory response element-reporter assay may be used as an alternative to virus-dependent, cytopathic assays. It contains a similar sensitivity to IFNs and can be completed in a shorter time than cytopathic assays and does not require heightened biosafety conditions after cell transduction. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Luciferase does not Alter Metabolism in Cancer Cells

    Science.gov (United States)

    Johnson, Caroline H.; Fisher, Timothy S.; Hoang, Linh T.; Felding, Brunhilde H.; Siuzdak, Gary; O’Brien, Peter J.

    2014-01-01

    Luciferase transfected cell lines are used extensively for cancer models, revealing valuable biological information about disease mechanisms. However, these genetically encoded reporters, while useful for monitoring tumor response in cancer models, can impact cell metabolism. Indeed firefly luciferase and fatty acyl-CoA synthetases differ by a single amino acid, raising the possibility that luciferase activity might alter metabolism and introduce experimental artifacts. Therefore knowledge of the metabolic response to luciferase transfection is of significant importance, especially given the thousands of research studies using luciferase as an in vivo bioluminescence imaging (BLI) reporter. Untargeted metabolomics experiments were performed to examine three different types of lymphoblastic leukemia cell lines (Ramos, Raji and SUP T1) commonly used in cancer research, each were analyzed with and without vector transduction. The Raji model was also tested under perturbed starvation conditions to examine potential luciferase-mediated stress responses. The results showed that no significant metabolic differences were observed between parental and luciferase transduced cells for each cell line, and that luciferase overexpression does not alter cell metabolism under basal or perturbed conditions. PMID:24791164

  2. Towards enhancement of performance of K-means clustering using nature-inspired optimization algorithms.

    Science.gov (United States)

    Fong, Simon; Deb, Suash; Yang, Xin-She; Zhuang, Yan

    2014-01-01

    Traditional K-means clustering algorithms have the drawback of getting stuck at local optima that depend on the random values of initial centroids. Optimization algorithms have their advantages in guiding iterative computation to search for global optima while avoiding local optima. The algorithms help speed up the clustering process by converging into a global optimum early with multiple search agents in action. Inspired by nature, some contemporary optimization algorithms which include Ant, Bat, Cuckoo, Firefly, and Wolf search algorithms mimic the swarming behavior allowing them to cooperatively steer towards an optimal objective within a reasonable time. It is known that these so-called nature-inspired optimization algorithms have their own characteristics as well as pros and cons in different applications. When these algorithms are combined with K-means clustering mechanism for the sake of enhancing its clustering quality by avoiding local optima and finding global optima, the new hybrids are anticipated to produce unprecedented performance. In this paper, we report the results of our evaluation experiments on the integration of nature-inspired optimization methods into K-means algorithms. In addition to the standard evaluation metrics in evaluating clustering quality, the extended K-means algorithms that are empowered by nature-inspired optimization methods are applied on image segmentation as a case study of application scenario.

  3. Rad51 Promoter-Targeted Gene Therapy Is Effective for In Vivo Visualization and Treatment of Cancer

    Science.gov (United States)

    Hine, Christopher M; Seluanov, Andrei; Gorbunova, Vera

    2012-01-01

    Rad51 protein is overexpressed in a wide range of human cancers. Our previous in vitro studies demonstrated that a construct comprised Rad51 promoter driving expression of the diphtheria toxin A gene (pRad51-diphtheria toxin A (DTA)) destroys a variety of human cancer cell lines, with minimal to no toxicity to normal human cells. Here we delivered Rad51 promoter-based constructs in vivo using linear polyethylenimine nanoparticles, in vivo jetPEI, to visualize and treat tumors in mice with HeLa xenografts. For tumor detection, we used pRad51-Luc, a construct containing the firefly luciferase under the Rad51 promoter, administered by intraperitoneal (IP) injection. Tumors were detected with an in vivo bioluminescent camera. All mice with cancer displayed strong bioluminescence, while mice without cancer displayed no detectable bioluminescence. Treatment with pRad51-DTA/jetPEI decreased tumor mass of subcutaneous (SC) and IP tumors by sixfold and fourfold, respectively, along with the strong reduction of malignant ascites. Fifty percent of the mice with SC tumors were cancer-free after six pRad51-DTA/jetPEI injections, and for the mice with IP tumors, mean survival time increased by 90% compared to control mice. This study demonstrates the clinical potential of pRad51-based constructs delivered by nanoparticles for the diagnostics and treatment of a wide range of cancers. PMID:22008909

  4. An Mx1 promoter-reporter system to study interferon pathways in rainbow trout.

    Science.gov (United States)

    Collet, Bertrand; Boudinot, Pierre; Benmansour, Abdenour; Secombes, Christopher J

    2004-06-01

    A rainbow trout interferon (IFN) reporter system has been established by selection of a stable cell line, RTG-P1, transfected with a plasmid expressing the firefly luciferase gene under the control of the promoter for the IFN-induced gene Mx1. After 148 passages, the luciferase expression was still highly induced by polyinosinic:polycytidylic acid (poly I:C) in RTG-P1 cells. Different IFN inducers (dsRNA, viral hemorrhagic septicaemia virus or conditioned medium containing rainbow trout antiviral activity) were able to stimulate the IFN-reporter system in RTG-P1, showing that this cell line can be used to study the activation of the IFN pathway in various contexts. Pyrrolidine dithiocarbamate (PDTC), an NF-kappaB inhibitor, significantly blocked poly I:C induced luciferase accumulation in RTG-P1 at intermediate doses (1-10 microM), suggesting that Mx1 induction through the IFN signalling pathway is NF-kappaB-dependent in fish. This inhibition was not observed for doses of 50 microM or higher. The RTG-P1 reporter system constitutes an interesting tool to study the induction and regulation of IFN signalling in teleost fish.

  5. A recombinant CHSE-214 cell line expressing an Mx1 promoter-reporter system responds to both interferon type I and type II from salmonids and represents a versatile tool to study the IFN-system in teleost fish.

    Science.gov (United States)

    Jørgensen, Jorunn B; Johansen, Audny; Hegseth, Marit N; Zou, Jun; Robertsen, Børre; Collet, Bertrand; Secombes, Christopher J

    2007-12-01

    A transgenic cell line for the detection of salmon interferons (IFNs) has been established. It is based on a CHSE-214 cell line containing a reporter construct expressing firefly luciferase under the control of the rainbow trout promoter for the IFN-induced Mx1 gene. This cell line, named CHSE-Mx10, showed IFN-induced luciferase expression after more than 80 passages, confirming the stability of this cell line. Interestingly, the Mx promoter was shown to respond to both salmon IFN-alpha/beta and trout IFN-gamma in a dose-dependent manner, while there was no response to TNF-alpha and IL-1beta. IFN-alpha/beta activity could be measured at a range of 9-150 U/ml, and IFN-gamma showed activity between 10 and 100 ng/ml. The reproducibility of both responses was good. The CHSE-Mx10 reporter system constitutes a versatile tool to study the induction and regulation of IFN signaling in teleost fish. A preliminary study presented herein suggests that both infectious pancreas necrosis virus (IPNV) and salmon pancreas disease virus (SPDV) may block activation of the Mx promoter in CHSE-Mx10 stimulated with IFN-alpha/beta.

  6. Synchronization Analysis: Are such Nonlinear Techniques Useful for Earth Sciences? (Invited)

    Science.gov (United States)

    Kurths, J.

    2009-12-01

    Synchronization phenomena are abundant in nature, science, engineering and social life, such as in organ pipes, fireflies and even in the mechanics of bridges. But synchronization was first recognized by Christiaan Huygens in 1665 for coupled pendulum clocks; this was the beginning of nonlinear sciences. In the last two decades, this concept has been successfully extended to more complex systems and the following basic phenomena have been found in coupled chaotic systems: complete synchronization (CS), generalized synchronization (GS), and phase synchronization (PS). Here we discuss two general concepts of nonlinear dynamics how to identify such complex synchronization phenomena in multivariate time series; the first is based on the Hilbert transform and the second one on recurrence. We show that the corresponding methods can be applied even to rather short and somewhat non-stationary data. Finally, applications are presented to study dynamic teleconnections, such as El Nino - Monsoon interactions. References Pikovsky, A., M. Rosenblum, and J. Kurths, Synchronization - A Universal Concept in Nonlinear Sciences, Cambridge University Press 2001. Boccaletti, S., J. Kurths, G. Osipov, and C. Zhou, Phys. Rep. 2002, 366, 1. Maraun, D., and J. Kurths, Geophys. Res. Lett. 2005, 32, L15709 Marwan, N., Thiel, M., Romano, M., and J. Kurths, Phys. Rep. 2007, 438, 237. Tokuda, I., Kurths, J., Kiss, I., and J. Hudson, Europhys. Lett. 2008 83, 50003.

  7. Development of a Fish Cell Biosensor System for Genotoxicity Detection Based on DNA Damage-Induced Trans-Activation of p21 Gene Expression

    Directory of Open Access Journals (Sweden)

    Huarong Guo

    2012-09-01

    Full Text Available p21CIP1/WAF1 is a p53-target gene in response to cellular DNA damage. Here we report the development of a fish cell biosensor system for high throughput genotoxicity detection of new drugs, by stably integrating two reporter plasmids of pGL3-p21-luc (human p21 promoter linked to firefly luciferase and pRL-CMV-luc (CMV promoter linked to Renilla luciferase into marine flatfish flounder gill (FG cells, referred to as p21FGLuc. Initial validation of this genotoxicity biosensor system showed that p21FGLuc cells had a wild-type p53 signaling pathway and responded positively to the challenge of both directly acting genotoxic agents (bleomycin and mitomycin C and indirectly acting genotoxic agents (cyclophosphamide with metabolic activation, but negatively to cyclophosphamide without metabolic activation and the non-genotoxic agents ethanol and D-mannitol, thus confirming a high specificity and sensitivity, fast and stable response to genotoxic agents for this easily maintained fish cell biosensor system. This system was especially useful in the genotoxicity detection of Di(2-ethylhexyl phthalate (DEHP, a rodent carcinogen, but negatively reported in most non-mammalian in vitro mutation assays, by providing a strong indication of genotoxicity for DEHP. A limitation for this biosensor system was that it might give false positive results in response to sodium butyrate and any other agents, which can trans-activate the p21 gene in a p53-independent manner.

  8. An optimized triple modality reporter for quantitative in vivo tumor imaging and therapy evaluation.

    Science.gov (United States)

    Levin, Rachel A; Felsen, Csilla N; Yang, Jin; Lin, John Y; Whitney, Michael A; Nguyen, Quyen T; Tsien, Roger Y

    2014-01-01

    We present an optimized triple modality reporter construct combining a far-red fluorescent protein (E2-Crimson), enhanced firefly luciferase enzyme (Luc2), and truncated wild type herpes simplex virus I thymidine kinase (wttk) that allows for sensitive, long-term tracking of tumor growth in vivo by fluorescence, bioluminescence, and positron emission tomography. Two human cancer cell lines (MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer) were successfully transduced to express this triple modality reporter. Fluorescence and bioluminescence imaging of the triple modality reporter were used to accurately quantify the therapeutic responses of MDA-MB-231 tumors to the chemotherapeutic agent monomethyl auristatin E in vivo in athymic nude mice. Positive correlation was observed between the fluorescence and bioluminescence signals, and these signals were also positively correlated with the ex vivo tumor weights. This is the first reported use of both fluorescence and bioluminescence signals from a multi-modality reporter construct to measure drug efficacy in vivo.

  9. An optimized triple modality reporter for quantitative in vivo tumor imaging and therapy evaluation.

    Directory of Open Access Journals (Sweden)

    Rachel A Levin

    Full Text Available We present an optimized triple modality reporter construct combining a far-red fluorescent protein (E2-Crimson, enhanced firefly luciferase enzyme (Luc2, and truncated wild type herpes simplex virus I thymidine kinase (wttk that allows for sensitive, long-term tracking of tumor growth in vivo by fluorescence, bioluminescence, and positron emission tomography. Two human cancer cell lines (MDA-MB-231 breast cancer and HT-1080 fibrosarcoma cancer were successfully transduced to express this triple modality reporter. Fluorescence and bioluminescence imaging of the triple modality reporter were used to accurately quantify the therapeutic responses of MDA-MB-231 tumors to the chemotherapeutic agent monomethyl auristatin E in vivo in athymic nude mice. Positive correlation was observed between the fluorescence and bioluminescence signals, and these signals were also positively correlated with the ex vivo tumor weights. This is the first reported use of both fluorescence and bioluminescence signals from a multi-modality reporter construct to measure drug efficacy in vivo.

  10. β3-Naphthoflavone Can Inhibit Luciferase Activity%β-萘黄酮能抑制荧光素酶活性

    Institute of Scientific and Technical Information of China (English)

    王胜; 陈云芳; 付欣; 洪伟; 李冰

    2011-01-01

    Objective: To investigate the effect of p-Naphthoflavone on the firefly luciferase activity. Methods: A549, HepG2, HeLa, MCF-7, Bel-7402, 16HBE cells were transfected with GCLC5'-upstream regulatory sequence driven PGL3-enhancer-Luciferase reporter vector (PL45)and treated with β-NF. The dual-luciferase reporter assay system was used to analyze the effect of β-Naphthoflavone on the expression of GCLC gene. Western blot was used to detect the change of protein level. AS49 and HepG2 cells were transfected with the eukaryotic expression vector pRC/CMV2- luc+ and treated with β-NF. The dual-luciferase reporter assay system was used to analyze the effect of β-Naphthoflavone on the firefly luciferase activity. AS49 and HepG2 cells were transfected with the PL45 vector, cells were lysed, then treated with β-NF for 25 min to analyze the effect of β-NF on the firefly luciferase activity. Results: In all the cells, the relative luciferase activity of β-NF treatment group was significantly lower compared with that in DMSO control group (P<0.01). The result of western bot showed that the expression of GCLC were higher inβ-NF treatment group than that in DMSO control group. In A549 and HepG2 cells, after transfected with pRC/CMV2- luc+ vector, the relative luciferase activity of β-NF treatment group was lower than that in DMSO control group (P<0.01 ).A549 and HepG2 cells were transfected with PL45 vector, then lysed, and the relative luciferase activity in β-NF treatment group was lower than that in DMSO control group (P<0.01).Conclusion: β-Naphthoflavone directly inhibits Firefly Luciferase activity.%目的:研究β-蔡黄酮对荧光素酶活性的影响.方法:利用人GCLC基因调控序列驱动的GCLC-PGL3-enhancer-Luciferase报道载体( PL45)转染人肺腺癌细胞A549,人肝癌细胞HepG2,人子宫颈癌细胞HeLa,人乳腺癌细胞MCF-7,人肝癌细胞Bel-7402,人支气管上皮细胞16HBE,β-萘黄酮刺激后,双荧光素酶报告基因检测系统分

  11. Gomisin N in the herbal drug gomishi (Schisandra chinensis) suppresses inducible nitric oxide synthase gene via C/EBPβ and NF-κB in rat hepatocytes.

    Science.gov (United States)

    Takimoto, Yuna; Qian, Hai-Yan; Yoshigai, Emi; Okumura, Tadayoshi; Ikeya, Yukinobu; Nishizawa, Mikio

    2013-01-15

    Gomishi is the dried fruit of Schisandra chinensis Baillon (Fructus Schisandrae chinensis, FSC) and has been used in Japanese Kampo medicine to treat inflammatory and liver diseases. However, it is unclear which constituent of FSC is primarily responsible for its pharmacological effects. FSC was extracted with methanol, fractionated by hydrophobicity, and further purified. We measured the effects of each fraction or constituent thereof on the induction of the inflammatory mediator nitric oxide (NO), which was induced by interleukin 1β in primary cultured rat hepatocytes. The hydrophobic fraction markedly suppressed NO induction and reduced the expression of inducible nitric oxide syntheses (iNOS) in interleukin 1β-treated hepatocytes. Gomisin N and γ-schizandrin, two major constituents of the hydrophobic fraction, significantly reduced NO production and the levels of the iNOS protein, mRNA, and antisense transcript. Gomisin N and γ-schizandrin also decreased the transcription of interleukin 1β and inflammatory chemokines. The overexpression of the p65 subunit of nuclear factor κB or CCAAT/enhancer-binding protein β increased the promoter activity of the iNOS gene in the firefly luciferase assay, whereas gomisin N decreased the promoter activity. The anti-inflammatory activity of FSC and its constituents were analysed, and we demonstrated that gomisin N and γ-schizandrin are involved in the hepatoprotective effect of the FSC extract, which has therapeutic potential for liver disease.

  12. Intracranial elimination of human glioblastoma brain tumors in nude rats using the bispecific ligand-directed toxin, DTEGF13 and convection enhanced delivery.

    Science.gov (United States)

    Oh, Seunguk; Ohlfest, John R; Todhunter, Deborah A; Vallera, Vincent D; Hall, Walter A; Chen, Hua; Vallera, Daniel A

    2009-12-01

    A bispecific ligand-directed toxin (BLT) consisting of human interleukin-13, epithelial growth factor, and the first 389 amino acids of diphtheria toxin was assembled in order to target human glioblastoma. In vitro, DTEGF13 selectively killed the human glioblastoma cell line U87-luc as well as other human glioblastomas. DTEGF13 fulfilled the requirement of a successful BLT by having greater activity than either of its monospecific counterparts or their mixture proving it necessary to have both ligands on the same single chain molecule. Aggressive brain tumors established intracranially (IC) in nude rats with U87 glioma genetically marked with a firefly luciferase reporter gene were treated with two injections of DTEGF13 using convection enhanced delivery resulting in tumor eradication in 50% of the rats which survived with tumor free status at least 110 days post tumor inoculation. An irrelevant BLT control did not protect establishing specificity. The bispecific DTEGF13 MTD dose was measured at 2 microg/injection or 0.5 microg/kg and toxicity studies indicated safety in this dose. Combination of monospecific DTEGF and DTIL13 did not inhibit tumor growth. ELISA assay indicated that anti-DT antibodies were not generated in normal immunocompetent rats given identical intracranial DTEGF13 therapy. Thus, DTEGF13 is safe and efficacious as an alternative drug for glioblastoma therapy and warrants further study.

  13. Design and analysis of tilt integral derivative controller with filter for load frequency control of multi-area interconnected power systems.

    Science.gov (United States)

    Kumar Sahu, Rabindra; Panda, Sidhartha; Biswal, Ashutosh; Chandra Sekhar, G T

    2016-03-01

    In this paper, a novel Tilt Integral Derivative controller with Filter (TIDF) is proposed for Load Frequency Control (LFC) of multi-area power systems. Initially, a two-area power system is considered and the parameters of the TIDF controller are optimized using Differential Evolution (DE) algorithm employing an Integral of Time multiplied Absolute Error (ITAE) criterion. The superiority of the proposed approach is demonstrated by comparing the results with some recently published heuristic approaches such as Firefly Algorithm (FA), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) optimized PID controllers for the same interconnected power system. Investigations reveal that proposed TIDF controllers provide better dynamic response compared to PID controller in terms of minimum undershoots and settling times of frequency as well as tie-line power deviations following a disturbance. The proposed approach is also extended to two widely used three area test systems considering nonlinearities such as Generation Rate Constraint (GRC) and Governor Dead Band (GDB). To improve the performance of the system, a Thyristor Controlled Series Compensator (TCSC) is also considered and the performance of TIDF controller in presence of TCSC is investigated. It is observed that system performance improves with the inclusion of TCSC. Finally, sensitivity analysis is carried out to test the robustness of the proposed controller by varying the system parameters, operating condition and load pattern. It is observed that the proposed controllers are robust and perform satisfactorily with variations in operating condition, system parameters and load pattern.

  14. Travelling Wave Pulse Coupled Oscillator (TWPCO) Using a Self-Organizing Scheme for Energy-Efficient Wireless Sensor Networks.

    Science.gov (United States)

    Al-Mekhlafi, Zeyad Ghaleb; Hanapi, Zurina Mohd; Othman, Mohamed; Zukarnain, Zuriati Ahmad

    2017-01-01

    Recently, Pulse Coupled Oscillator (PCO)-based travelling waves have attracted substantial attention by researchers in wireless sensor network (WSN) synchronization. Because WSNs are generally artificial occurrences that mimic natural phenomena, the PCO utilizes firefly synchronization of attracting mating partners for modelling the WSN. However, given that sensor nodes are unable to receive messages while transmitting data packets (due to deafness), the PCO model may not be efficient for sensor network modelling. To overcome this limitation, this paper proposed a new scheme called the Travelling Wave Pulse Coupled Oscillator (TWPCO). For this, the study used a self-organizing scheme for energy-efficient WSNs that adopted travelling wave biologically inspired network systems based on phase locking of the PCO model to counteract deafness. From the simulation, it was found that the proposed TWPCO scheme attained a steady state after a number of cycles. It also showed superior performance compared to other mechanisms, with a reduction in the total energy consumption of 25%. The results showed that the performance improved by 13% in terms of data gathering. Based on the results, the proposed scheme avoids the deafness that occurs in the transmit state in WSNs and increases the data collection throughout the transmission states in WSNs.

  15. Analysis of the sericin1 promoter and assisted detection of exogenous gene expression efficiency in the silkworm Bombyx mori L.

    Science.gov (United States)

    Ye, Lupeng; Qian, Qiujie; Zhang, Yuyu; You, Zhengying; Che, Jiaqian; Song, Jia; Zhong, Boxiong

    2015-02-06

    In genetics, the promoter is one of the most important regulatory elements controlling the spatiotemporal expression of a target gene. However, most studies have focused on core or proximal promoter regions, and information on regions that are more distant from the 5'-flanking region of the proximal promoter is often lacking. Here, approximately 4-kb of the sericin1 (Ser1) promoter was predicted to contain many potential transcriptional factor binding sites (TFBSs). Transgenic experiments have revealed that more TFBSs included in the promoter improved gene transcription. However, multi-copy proximal Ser1 promoter combinations did not improve gene expression at the transcriptional level. Instead, increasing the promoter copy number repressed transcription. Furthermore, a correlation analysis between two contiguous genes, firefly luciferase (FLuc) and EGFP, was conducted at the transcriptional level; a significant correlation was obtained regardless of the insertion site. The ELISA results also revealed a significant correlation between the transcriptional and translational EGFP levels. Therefore, the exogenous gene expression level can be predicted by simply detecting an adjacent EGFP. In conclusion, our results provide important insights for further investigations into the molecular mechanisms underlying promoter function. Additionally, a new approach was developed to quickly screen transgenic strains that highly express exogenous genes.

  16. Theophylline-dependent riboswitch as a novel genetic tool for strict regulation of protein expression in Cyanobacterium Synechococcus elongatus PCC 7942.

    Science.gov (United States)

    Nakahira, Yoichi; Ogawa, Atsushi; Asano, Hiroyuki; Oyama, Tokitaka; Tozawa, Yuzuru

    2013-10-01

    The cyanobacterium Synechococcus elongatus PCC 7942 is a major model species for studies of photosynthesis. It is are also a potential cell factory for the production of renewable biofuels and valuable chemicals. We employed engineered riboswitches to control translational initiation of target genes in this cyanobacterium. A firefly luciferase reporter assay revealed that three theophylline riboswitches performed as expected in the cyanobacterium. Riboswitch-E* exhibited very low leaky expression of luciferase and superior and dose-dependent on/off regulation of protein expression by theophylline. The maximum magnitude of the induction vs. basal level was ∼190-fold. Furthermore, the induction level was responsive to a wide range of theophylline concentrations in the medium, from 0 to 2 mM, facilitating the fine-tuning of luciferase expression. We adapted this riboswitch to another gene regulation system, in which expression of the circadian clock kaiC gene product is controlled by the theophylline concentration in the culture medium. The results demonstrated that the adequately adjusted expression level of KaiC restored complete circadian rhythm in the kaiC-deficient arrhythmic mutant. This theophylline-dependent riboswitch system has potential for various applications as a useful genetic tool in cyanobacteria.

  17. Meeting report for Odd Pols 2016: Ann Arbor 2.0.

    Science.gov (United States)

    Roy-Engel, Astrid M

    2017-05-15

    The Tenth International Conference on Transcription by RNA Polymerases I, III, IV and V (the 'Odd Pols') was held June 24-28, 2016 at the University of Michigan, Ann Arbor, USA and organized by David Engelke, Deborah Johnson, Richard Maraia, Lawrence Rothblum, David Schneider, Andrzej Wierzbicki and Astrid Engel. The organizers are grateful for the support from the Rackham Graduate School of the University of Michigan for providing the meeting venue. The environment provided a great background with unexpected encounters with fireflies, free live music and a festive fireworks display. The meeting was composed of eleven oral sessions and a poster session. The keynote speaker, Dave Engelke, opened the meeting with his presentation entitled "A personal history of pol III transcription - how we got here from the 'good old days'." The meeting drew attendees from sixteen countries that shared their research discoveries. Here we present some of the highlights from the meeting using summaries provided by the participants. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A multimodality imaging model to track viable breast cancer cells from single arrest to metastasis in the mouse brain

    Science.gov (United States)

    Parkins, Katie M.; Hamilton, Amanda M.; Makela, Ashley V.; Chen, Yuanxin; Foster, Paula J.; Ronald, John A.

    2016-10-01

    Cellular MRI involves sensitive visualization of iron-labeled cells in vivo but cannot differentiate between dead and viable cells. Bioluminescence imaging (BLI) measures cellular viability, and thus we explored combining these tools to provide a more holistic view of metastatic cancer cell fate in mice. Human breast carcinoma cells stably expressing Firefly luciferase were loaded with iron particles, injected into the left ventricle, and BLI and MRI were performed on days 0, 8, 21 and 28. The number of brain MR signal voids (i.e., iron-loaded cells) on day 0 significantly correlated with BLI signal. Both BLI and MRI signals decreased from day 0 to day 8, indicating a loss of viable cells rather than a loss of iron label. Total brain MR tumour volume on day 28 also correlated with BLI signal. Overall, BLI complemented our sensitive cellular MRI technologies well, allowing us for the first time to screen animals for successful injections, and, in addition to MR measures of cell arrest and tumor burden, provided longitudinal measures of cancer cell viability in individual animals. We predict this novel multimodality molecular imaging framework will be useful for evaluating the efficacy of emerging anti-cancer drugs at different stages of the metastatic cascade.

  19. Investigation into the efficiency of different bionic algorithm combinations for a COBRA meta-heuristic

    Science.gov (United States)

    Akhmedova, Sh; Semenkin, E.

    2017-02-01

    Previously, a meta-heuristic approach, called Co-Operation of Biology-Related Algorithms or COBRA, for solving real-parameter optimization problems was introduced and described. COBRA’s basic idea consists of a cooperative work of five well-known bionic algorithms such as Particle Swarm Optimization, the Wolf Pack Search, the Firefly Algorithm, the Cuckoo Search Algorithm and the Bat Algorithm, which were chosen due to the similarity of their schemes. The performance of this meta-heuristic was evaluated on a set of test functions and its workability was demonstrated. Thus it was established that the idea of the algorithms’ cooperative work is useful. However, it is unclear which bionic algorithms should be included in this cooperation and how many of them. Therefore, the five above-listed algorithms and additionally the Fish School Search algorithm were used for the development of five different modifications of COBRA by varying the number of component-algorithms. These modifications were tested on the same set of functions and the best of them was found. Ways of further improving the COBRA algorithm are then discussed.

  20. Combined cisplatin and aurora inhibitor treatment increase neuroblastoma cell death but surviving cells overproduce BDNF.

    Science.gov (United States)

    Polacchini, Alessio; Albani, Clara; Baj, Gabriele; Colliva, Andrea; Carpinelli, Patrizia; Tongiorgi, Enrico

    2016-07-15

    Drug-resistance to chemotherapics in aggressive neuroblastoma (NB) is characterized by enhanced cell survival mediated by TrkB and its ligand, brain-derived neurotrophic factor (BDNF); thus reduction in BDNF levels represent a promising strategy to overcome drug-resistance, but how chemotherapics regulate BDNF is unknown. Here, cisplatin treatment in SK-N-BE neuroblastoma upregulated multiple BDNF transcripts, except exons 5 and 8 variants. Cisplatin increased BDNF mRNA and protein, and enhanced translation of a firefly reporter gene flanked by BDNF 5'UTR exons 1, 2c, 4 or 6 and 3'UTR-long. To block BDNF translation we focused on aurora kinases inhibitors which are proposed as new chemotherapeutics. NB cell survival after 24 h treatment was 43% with cisplatin, and 22% by cisplatin+aurora kinase inhibitor PHA-680632, while the aurora kinases inhibitor alone was less effective; however the combined treatment induced a paradoxical increase of BDNF in surviving cells with strong translational activation of exon6-3'UTR-long transcript, while translation of BDNF transcripts 1, 2C and 4 was suppressed. In conclusion, combined cisplatin and aurora kinase inhibitor treatment increases cell death, but induces BDNF overproduction in surviving cells through an aurora kinase-independent mechanism.

  1. Minor C-geranylated flavanones from Paulownia tomentosa fruits with MRSA antibacterial activity.

    Science.gov (United States)

    Navrátilová, Alice; Schneiderová, Kristýna; Veselá, Daniela; Hanáková, Zuzana; Fontana, Anna; Dall'Acqua, Stefano; Cvačka, Josef; Innocenti, Gabbriella; Novotná, Jana; Urbanová, Marie; Pelletier, Jerry; Čížek, Alois; Žemličková, Helena; Šmejkal, Karel

    2013-05-01

    Exhaustive chromatographic separation of the chloroform portion of the ethanolic extract obtained from Paulownia tomentosa (Thunb). Steud. (Paulowniaceae) fruits has led to isolation of ten C-6 geranylated flavanones tomentodiplacone C-I and mimulone C-E, featured by 3'-methoxy and 4'-hydroxy or 4'-hydroxy substitution of the B-ring of the flavonoid, respectively. The structures of these compounds were determined by using mass spectrometry (including HRMS) and 1D and 2D NMR spectroscopy. The absolute configurations of the compounds at C-2 were determined using circular dichroism. The obtained compounds showed the presence of a geranyl moiety functionalized by a carbonyl, hydroxyl or methoxyl group, or by formation of tetrahydrofuran or fused-pyrane ring, respectively. All of the flavanones described were isolated for the first time from a natural source. The antibacterial activities of selected compounds isolated along with the previously isolated geranylated flavanones were evaluated against a common panel of microbes and MRSA strains. The selected isolated compounds were tested for their ability to affect eukaryotic translation initiation via dual-luciferase reporter assay (firefly and renilla).

  2. ATF-2 stimulates the human insulin promoter through the conserved CRE2 sequence.

    Science.gov (United States)

    Hay, Colin W; Ferguson, Laura A; Docherty, Kevin

    2007-02-01

    The insulin promoter contains a number of dissimilar cis-acting regulatory elements that bind a range of tissue specific and ubiquitous transcription factors. Of the regulatory elements within the insulin promoter, the cyclic AMP responsive element (CRE) binds by far the most diverse array of transcription factors. Rodent insulin promoters have a single CRE site, whereas there are four CREs within the human insulin gene, of which CRE2 is the only one conserved between species. The aim of this study was to characterise the human CRE2 site and to investigate the effects of the two principal CRE-associated transcription factors; CREB-1 and ATF-2. Co-transfection of INS-1 pancreatic beta-cells with promoter constructs containing the human insulin gene promoter placed upstream of the firefly luciferase reporter gene and expression plasmids for ATF-2 or CREB-1 showed that ATF-2 stimulated transcriptional activity while CREB-1 elicited an inhibitory effect. Mutagenesis of CRE2 diminished the effect of ATF-2 but not that of CREB-1. ATF-2 was shown to bind to the CRE2 site by electrophoretic mobility shift assay and by chromatin immunoprecipitation, while siRNA mediated knockdown of ATF-2 diminished the stimulatory effects of cAMP related signalling on promoter activity. These results suggest that ATF-2 may be a key regulator of the human insulin promoter possibly stimulating activity in response to extracellular signals.

  3. Development and characterization of a Pseudomonas aeruginosa in vitro coupled transcription-translation assay system for evaluation of translation inhibitors

    Science.gov (United States)

    Fyfe, Corey; Sutcliffe, Joyce A.; Grossman, Trudy H.

    2013-01-01

    Bacterial transcription and translation have proven to be effective targets for broad-spectrum antimicrobial therapies owing to the critical role they play in bacterial propagation and the overall conservation of the associated machinery involved. Escherichia coli is the most common source of S30 extract used in bacterial in vitro coupled transcription-translation assays, however, transcription-translation assays in other important pathogens including Staphylococcus aureus and Streptococcus pneumoniae have been described (Murray et al., 2001; Dandliker et al., 2003). Pseudomonas aeruginosa is an important and difficult-to-treat Gram-negative pathogen. In a drug discovery program, to de-risk any potential species specificity of novel inhibitors, we developed and optimized a robust method for the preparation of S30 extract from P. aeruginosa strain PAO1. Further, a P. aeruginosa transcription-translation assay using a firefly luciferase reporter plasmid was validated and compared to an E. coli S30-based system using a wide range of antibiotics encompassing multiple classes of translation inhibitors. Results showed a similar ranking of the activities of known inhibitors, illustrative of the high degree of conservation between the transcription-translation pathways in both organisms. PMID:22677604

  4. Activation of BmGSTd1 promoter and regulation by transcription factor Krüppel (Kr) in silkworm, Bombyx mori.

    Science.gov (United States)

    Zhao, Guodong; Wang, Binbin; Liu, Yunlei; Du, Jie; Li, Bing; Chen, Yuhua; Xu, Yaxiang; Shen, Weide; Xia, Qingyou; Wei, Zhengguo

    2014-11-10

    The Glutathione S-transferases (GSTs) are a large family of multifunctional enzymes, many of which play an important role in the detoxification of endogenous and exogenous toxic substances. In this research, firstly, we measured the rutin-induced transcriptional level of BmGSTd1 gene by using real-time quantitative RT-PCR method and dual spike-in strategy. The activities of the BmGSTd1 promoter in various tissues of silkworm were measured by firefly luciferase activity and normalized by the Renilla luciferase activity. Results showed that the activity of the BmGSTd1 promoter were highest in Malpighian tubule, followed by fat body, silk gland, hemocyte, epidermis, and midgut. The essential region for basal and rutin-induced transcriptional activity was -1573 to -931bp in Malpighian tubule and fat body of silkworm. Promoter truncation analysis using a dual-luciferase reporter assay in BmN cells showed that the region -1288 to -1202bp for BmGSTd1 gene was essential for basal and rutin-induced transcriptional activity. Sequence analysis of this region revealed several potential transcriptional regulatory elements such as Bcd and Kr. The mutation of core base of Kr site demonstrated that Kr functioned positively in rutin-mediated BmGSTd1 transcription.

  5. Spatially Resolved Stellar Populations Of Nearby Post-Starburst Galaxies In SDSS-IV MaNGA

    Science.gov (United States)

    Liu, Charles; Betances, Ashley; Bonilla, Alaina Marie; Gonzalez, Andrea; Migliore, Christina; Goddard, Daniel; Masters, Karen; SDSS-IV MaNGA Team

    2016-01-01

    We have selected five galaxies in the Mapping Nearby Galaxies at APO (MaNGA) project of the latest generation of the Sloan Digital Sky Survey (SDSS-IV) identified as post-starburst (E+A) systems, in the transition between "blue cloud" and "red sequence" galaxies. We measure the equivalent widths of the Balmer series, D4000 break, and metal lines across each galaxy, and produce maps of the stellar age, stellar mass, and metallicities of each galaxy using FIREFLY, a full spectral analysis code. We have found that the measured properties of the galaxies overall generally matches well with single-aperture SDSS spectra from which the original post-starburst identifications were made. The variation in the spatial distributions of the stellar populations, in particular the A-stars, give us insight into the details of the transitional E+A quenching phase. This work was supported by the Alfred P. Sloan Foundation via the SDSS-IV Faculty and Student Team (FAST) initiative, ARC Agreement No. SSP483 to the CUNY College of Staten Island.

  6. Rational design of novel N-alkyl-N capped biostable RNA nanostructures for efficient long-term inhibition of gene expression

    Science.gov (United States)

    Terrazas, Montserrat; Ivani, Ivan; Villegas, Núria; Paris, Clément; Salvans, Cándida; Brun-Heath, Isabelle; Orozco, Modesto

    2016-01-01

    Computational techniques have been used to design a novel class of RNA architecture with expected improved resistance to nuclease degradation, while showing interference RNA activity. The in silico designed structure consists of a 24–29 bp duplex RNA region linked on both ends by N-alkyl-N dimeric nucleotides (BCn dimers; n = number of carbon atoms of the alkyl chain). A series of N-alkyl-N capped dumbbell-shaped structures were efficiently synthesized by double ligation of BCn-loop hairpins. The resulting BCn-loop dumbbells displayed experimentally higher biostability than their 3′-N-alkyl-N linear version, and were active against a range of mRNA targets. We studied first the effect of the alkyl chain and stem lengths on RNAi activity in a screen involving two series of dumbbell analogues targeting Renilla and Firefly luciferase genes. The best dumbbell design (containing BC6 loops and 29 bp) was successfully used to silence GRB7 expression in HER2+ breast cancer cells for longer periods of time than natural siRNAs and known biostable dumbbells. This BC6-loop dumbbell-shaped structure displayed greater anti-proliferative activity than natural siRNAs. PMID:26975656

  7. Amplification, expression, and packaging of a foreign gene by giardiavirus in Giardia lamblia.

    Science.gov (United States)

    Yu, D C; Wang, A L; Wang, C C

    1996-12-01

    Giardia lamblia is an intestinal protozoan parasite and one of the earliest eukaryotic divergents. The trophozoite multiplies via asexual binary fission and lacks all natural means of lateral gene transfer. A system is developed here for long-term expression of a foreign gene in this organism by exploiting recombinant virions derived from the giardiavirus (GLV), a double-stranded RNA virus that infects many Giardia isolates. An in vitro transcript of the cloned GLV cDNA, comprising the firefly luciferase-encoding region flanked by 5' and 3' fragments of GLV positive-strand RNA, was electroporated into GLV-infected trophozoites. Luciferase activity in electroporated cells peaked on day 2 at levels 6 orders of magnitude above background. Expression of this foreign gene remained at 80% of its peak level after 30 days in the absence of selective pressure. The chimeric RNA was replicated as double-stranded RNA and packaged into virus-like particles. The recombinant virions were partially purified from the wild-type helper virus by CsCl equilibrium density-gradient centrifugation and used to superinfect Giardia trophozoites. At multiplicities of infection of 100 or higher, these chimeric virions were able to initiate new rounds of expression of luciferase activity in the superinfected cells. Thus, the engineered virion can be successfully used to introduce and efficiently express a heterologous gene in this eukaryotic microorganism.

  8. A lack of premature termination codon read-through efficacy of PTC124 (Ataluren) in a diverse array of reporter assays.

    Science.gov (United States)

    McElroy, Stuart P; Nomura, Toshifumi; Torrie, Leah S; Warbrick, Emma; Gartner, Ulrike; Wood, Gavin; McLean, W H Irwin

    2013-01-01

    The drug molecule PTC124 (Ataluren) has been described as a read-through agent, capable of suppressing premature termination codons (PTCs) and restoring functional protein production from genes disrupted by nonsense mutations. Following the discovery of PTC124 there was some controversy regarding its mechanism of action with two reports attributing its activity to an off-target effect on the Firefly luciferase (FLuc) reporter used in the development of the molecule. Despite questions remaining as to its mechanism of action, development of PTC124 continued into the clinic and it is being actively pursued as a potential nonsense mutation therapy. To thoroughly test the ability of PTC124 to read through nonsense mutations, we conducted a detailed assessment comparing the efficacy of PTC124 with the classical aminoglycoside antibiotic read-through agent geneticin (G418) across a diverse range of in vitro reporter assays. We can confirm the off-target FLuc activity of PTC124 but found that, while G418 exhibits varying activity in every read-through assay, there is no evidence of activity for PTC124.

  9. Chemical stress sensitive luminescent human cells: molecular biology approach using inducible Drosophila melanogaster hsp22 promoter.

    Science.gov (United States)

    Mandon, C A; Diaz, C; Arrigo, A-P; Blum, L J

    2005-09-23

    A whole-cell bioassay has been developed for the total toxicity testing of liquid samples. The method is based on the induction of the bioluminescent activity of genetically manipulated mammalian cells. For that purpose, transfection was used to introduce, in HeLa cells, a DNA sensing element that responds to chemical stress agents (heavy metals, genotoxic agents, and endocrine-disrupting chemicals). Such element was designed to direct the expression of a reporting gene (firefly luciferase) through the activation of Drosophila melanogaster hsp22 promoter. A molecular approach was conducted to optimize hsp22 promoter element in order to decrease the background expression level of the reporting gene and to increase the sensitivity of the bioassay for testing endocrine disruptors. As a result, in the presence of 20-100 microM cadmium chloride, a 6-fold increase in luciferase expression was obtained using a specially designed truncated hsp22 promoter construction. The following chemicals known to be found in the polluted samples were tested: CdCl2, Cd(NO3)2, NaAsO2, alachlore, fentine acetate, thiram, and maneb. The stressing effect of each of them was sensitively detected by the present bioassay in the 0.05-50 microM concentration range.

  10. Healing with animals in the Levant from the 10th to the 18th century

    Directory of Open Access Journals (Sweden)

    Lev Efraim

    2006-02-01

    Full Text Available Abstract Animals and products derived from different organs of their bodies have constituted part of the inventory of medicinal substances used in various cultures since ancient times. The article reviews the history of healing with animals in the Levant (The Land of Israel and parts of present-day Syria, Lebanon, and Jordan, defined by the Muslims in the Middle Ages as Bilad al-Sham in the medieval and early Ottoman periods. Intensive research into the phenomenon of zootherapy in the medieval and early Ottoman Levant has yielded forty-eight substances of animal origin that were used medicinally. The vast majority of these substances were local and relatively easy to obtain. Most of the substances were domestic (honey, wax, silkworm, etc., others were part of the local wildlife (adder, cuttle fish, flycatcher, firefly, frog, triton, scorpion, etc., part of the usual medieval household (milk, egg, cheese, lamb, etc., or parasites (louse, mouse, stinkbug, etc.. Fewer substances were not local but exotic, and therefore rare and expensive (beaver testicles, musk oil, coral, ambergris, etc.. The range of symptoms that the substances of animal origin were used to treat was extensive and included most of the known diseases and maladies of that era: mainly hemorrhoids, burns, impotence, wounds, and skin, eye, and stomach diseases. Changes in the moral outlook of modern societies caused the use of several substances of animal origin to cease in the course of history. These include mummy, silkworm, stinkbug, scarabees, snail, scorpion, and triton.

  11. Construction and applications of rabbit hemorrhagic disease virus replicon.

    Science.gov (United States)

    Wang, Binbin; Zhe, Mingjia; Chen, Zongyan; Li, Chuanfeng; Meng, Chunchun; Zhang, Miaotao; Liu, Guangqing

    2013-01-01

    The study of rabbit hemorrhagic disease virus (RHDV) has long been hindered by the absence of an in vitro culture system. In this study, using RHDV as a model, a series of DNA-based reporter replicons were constructed in which the firefly luciferase (Fluc) gene was fused in-frame with the open reading frame of the replicon. In this construct, the Fluc gene was inserted where the coding region of viral structural protein was deleted and was under the control of a minimal cytomegalovirus (CMV) immediate-early promoter. Fluc activity analysis showed that these reporter replicons replicate efficiently in mammalian cells. On the basis of the replicon, 5'non-coding regions (5'NCR) and genome-linked protein (VPg) were deleted, and the effect on the expression of replicon was analyzed. The results showed that the expression level of Fluc was reduced in the absence of 5'NCR and VPg, suggesting that the 5'NCR and VPg may play an important role in replication and/or translation of RHDV. To further verify the speculation, we also constructed a replication deficient mutant (pRHDV-luc/Δ3D), and the impact of 5'NCR and VPg deletion on viral translation efficiency was analyzed, our results indicated that both VPg and 5'NCR were involved in RHDV translation.

  12. Evaluation of monkeypox virus infection of prairie dogs (Cynomys ludovicianus) using in vivo bioluminescent imaging

    Science.gov (United States)

    Falendysz, Elizabeth A.; Londoño-Navas, Angela M.; Meteyer, Carol U.; Pussini, Nicola; Lopera, Juan G.; Osorio, Jorge E.; Rocke, Tonie E.

    2014-01-01

    Monkeypox (MPX) is a re-emerging zoonotic disease that is endemic in Central and West Africa, where it can cause a smallpox-like disease in humans. Despite many epidemiologic and field investigations of MPX, no definitive reservoir species has been identified. Using recombinant viruses expressing the firefly luciferase (luc) gene, we previously demonstrated the suitability of in vivo bioluminescent imaging (BLI) to study the pathogenesis of MPX in animal models. Here, we evaluated BLI as a novel approach for tracking MPX virus infection in black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs were affected during a multistate outbreak of MPX in the US in 2003 and have since been used as an animal model of this disease. Our BLI results were compared with PCR and virus isolation from tissues collected postmortem. Virus was easily detected and quantified in skin and superficial tissues by BLI before and during clinical phases, as well as in subclinical secondary cases, but was not reliably detected in deep tissues such as the lung. Although there are limitations to viral detection in larger wild rodent species, BLI can enhance the use of prairie dogs as an animal model of MPX and can be used for the study of infection, disease progression, and transmission in potential wild rodent reservoirs.

  13. Application of Heuristic and Metaheuristic Algorithms in Solving Constrained Weber Problem with Feasible Region Bounded by Arcs

    Directory of Open Access Journals (Sweden)

    Igor Stojanović

    2017-01-01

    Full Text Available The continuous planar facility location problem with the connected region of feasible solutions bounded by arcs is a particular case of the constrained Weber problem. This problem is a continuous optimization problem which has a nonconvex feasible set of constraints. This paper suggests appropriate modifications of four metaheuristic algorithms which are defined with the aim of solving this type of nonconvex optimization problems. Also, a comparison of these algorithms to each other as well as to the heuristic algorithm is presented. The artificial bee colony algorithm, firefly algorithm, and their recently proposed improved versions for constrained optimization are appropriately modified and applied to the case study. The heuristic algorithm based on modified Weiszfeld procedure is also implemented for the purpose of comparison with the metaheuristic approaches. Obtained numerical results show that metaheuristic algorithms can be successfully applied to solve the instances of this problem of up to 500 constraints. Among these four algorithms, the improved version of artificial bee algorithm is the most efficient with respect to the quality of the solution, robustness, and the computational efficiency.

  14. O menino e o efeito pirilampo: um estudo em psicossomática

    Directory of Open Access Journals (Sweden)

    Adriana Campos de Cerqueira Leite

    2003-06-01

    Full Text Available Este trabalho tem como objetivo discutir um fenômeno psicossomático - a alopécia - que marca a história de Yuri desde os seus três anos de idade. A metodologia utilizada é a de um estudo de caso, evidenciando os significantes que foram timbrados nessa criança com síndrome de Down e o lugar por ela ocupado no discurso parental. Fica evidente que o fenômeno psicossomático ataca o real do corpo, produzindo um imaginário familiar impossibilitado de ser atravessado pela ordem do simbólico. A direção do tratamento é a de produzir cadeia nas complexas relações entre as funções biológicas do corpo e da linguagem.The boy and the fire-fly effect. A study on psychosomatics. This work aims at discussing a psychosomatic phenomenon - alopecia - that has been marking the history of Yuri since he was three years old. The methodology used is that of a case study, which evidences the significant that were stamped on that child with Down syndrome and the place he occupies in the discourse of his parents. Obviously, this psychosomatic phenomenon attacks the real of the body, producing a family imaginary cut from the symbolic order. The treatment direction is to produce chains among the complex relationships between the biological functions of the body and the language.

  15. Continuous, real-time bioimaging of chemical bioavailability and toxicology using autonomously bioluminescent human cell lines

    Science.gov (United States)

    Xu, Tingting; Close, Dan M.; Webb, James D.; Price, Sarah L.; Ripp, Steven A.; Sayler, Gary S.

    2013-05-01

    Bioluminescent imaging is an emerging biomedical surveillance strategy that uses external cameras to detect in vivo light generated in small animal models of human physiology or in vitro light generated in tissue culture or tissue scaffold mimics of human anatomy. The most widely utilized of reporters is the firefly luciferase (luc) gene; however, it generates light only upon addition of a chemical substrate, thus only generating intermittent single time point data snapshots. To overcome this disadvantage, we have demonstrated substrate-independent bioluminescent imaging using an optimized bacterial bioluminescence (lux) system. The lux reporter produces bioluminescence autonomously using components found naturally within the cell, thereby allowing imaging to occur continuously and in real-time over the lifetime of the host. We have validated this technology in human cells with demonstrated chemical toxicological profiling against exotoxin exposures at signal strengths comparable to existing luc systems (~1.33 × 107 photons/second). As a proof-in-principle demonstration, we have engineered breast carcinoma cells to express bioluminescence for real-time screening of endocrine disrupting chemicals and validated detection of 17β-estradiol (EC50 = ~ 10 pM). These and other applications of this new reporter technology will be discussed as potential new pathways towards improved models of target chemical bioavailability, toxicology, efficacy, and human safety.

  16. Non-invasive monitoring of carcinogenesis in N-nitrosodiethylamine induced liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ju Hui; Kang, Joo Hyun; Lee, Yong Jin; Lee, Tae Sup; Kim, Kwang Il; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Park, Young Seo [Kyungwon University, Seongnam (Korea, Republic of)

    2010-10-15

    Molecular imaging based on reporter gene expression allows tissue-specific events or processes to be measured using the bioluminescence imaging (BLI) reporter gene expression vector controlled by specific enhancer/promoters. Alpha-fetoprotein (AFP), which is a tumor marker, is a serum glycoprotein that is expressed normally by fetal liver and yolk-sac cells, as well as in trace amounts in the fetal gastrointestinal tract. The serum concentration of AFP decreases rapidly after birth and its expression is repressed in adults. Approximately 80% of HCC patients show an increase in the AFP level. Therefore, AFP has been used for many years as a diagnostic and prognostic serum marker for HCC and transgenic system for AFP was proposed as a valuable tool for elucidation of mechanism of transcriptional regulation during liver development and hepatocarcinogenesis. In this study, firefly luciferase (fLuc) expressing transgenic mice controlled by the AFP enhancer/ promoter (enh/promoter) were produced to screen for the development of AFP-producing liver cancer. These models are expected to be useful for monitoring agents or drugs that modulate the AFP level as well as for measuring the specific signaling events important for liver cancer development

  17. Probing the ATP-Binding Pocket of Protein Kinase DYRK1A with Benzothiazole Fragment Molecules.

    Science.gov (United States)

    Rothweiler, Ulli; Stensen, Wenche; Brandsdal, Bjørn Olav; Isaksson, Johan; Leeson, Frederick Alan; Engh, Richard Alan; Svendsen, John S Mjøen

    2016-11-10

    DYRK1A has emerged as a potential target for therapies of Alzheimer's disease using small molecules. On the basis of the observation of selective DYRK1A inhibition by firefly d-luciferin, we have explored static and dynamic structural properties of fragment sized variants of the benzothiazole scaffold with respect to DYRK1A using X-ray crystallography and NMR techniques. The compounds have excellent ligand efficiencies and show a remarkable diversity of binding modes in dynamic equilibrium. Binding geometries are determined in part by interactions often considered "weak", including "orthogonal multipolar" types represented by, for example, F-CO, sulfur-aromatic, and halogen-aromatic interactions, together with hydrogen bonds that are modulated by variation of electron withdrawing groups. These studies show how the benzothiazole scaffold is highly promising for the development of therapeutic DYRK1A inhibitors. In addition, the subtleties of the binding interactions, including dynamics, show how full structural studies are required to fully interpret the essential physical determinants of binding.

  18. RNA helicase YTHDC2 promotes cancer metastasis via the enhancement of the efficiency by which HIF-1α mRNA is translated.

    Science.gov (United States)

    Tanabe, Atsushi; Tanikawa, Kenya; Tsunetomi, Mai; Takai, Kaori; Ikeda, Hiroto; Konno, Junpei; Torigoe, Toshihiko; Maeda, Hideki; Kutomi, Goro; Okita, Kenji; Mori, Mitsuru; Sahara, Hiroeki

    2016-06-28

    YTH domain containing 2 (YTHDC2) is a member of the DExD/H-box family of ATP-dependent RNA helicases. We previously found that YTHDC2 expression is up-regulated in several human cancer cells. In this study, we demonstrate novel roles for YTHDC2 in metastasis of colon tumor cells via translation-dependent pathway. Knockdown of YTHDC2 attenuated protein expression of metastasis-related genes, such as hypoxia-inducible factor-1alpha (HIF-1α), and inhibited metastasis of colon tumor cells in vitro and in vivo. To confirm that YTHDC2 promotes translation initiation by unwinding the 5'-untranslated region (5'UTR) of mRNA, we constructed a firefly luciferase reporter containing the 5'UTR of the HIF-1α mRNA and showed reduction in luciferase activity in YTHDC2-silenced cells. Furthermore, we examined expression levels of YTHDC2 by immunohistochemical staining in human colon cancer tissues from 72 patients and found a significantly positive correlation between YTHDC2 expression and the tumor stage, including metastasis. In conclusion, these results suggest that the RNA helicase YTHDC2 contributes to colon tumor metastasis by promoting translation of HIF-1α and that YTHDC2 is potentially a diagnostic marker and target gene for treating colon cancer patients.

  19. Construction of yellow fever virus subgenomic replicons by yeast-based homologous recombination cloning technique

    Directory of Open Access Journals (Sweden)

    Sabrina R.A. Queiroz

    2013-03-01

    Full Text Available RNA replicon derived from Flavivirus genome is a valuable tool for studying viral replication independent of virion assembly and maturation, besides being a great potencial for heterologous gene expression. In this study we described the construction of subgenomic replicons of yellow fever virus by yeast-based homologous recombination technique. The plasmid containing the yellow fever 17D strain replicon (pBSC-repYFV-17D, previously characterized, was handled to heterologous expression of the green fluorescent protein (repYFV-17D-GFP and firefly luciferase (repYFV-17D-Luc reporter genes. Both replicons were constructed by homologous recombination between the linearized vector pBSC-repYFV-17D and the PCR product containing homologous 25 nucleotides ends incorporated into PCR primers. The genomic organization of these constructs is similar to repYFV-17D, but with insertion of the reporter gene between the remaining 63 N-terminal nucleotides of the capsid protein and 72 C-terminal nucleotides of the E protein. The replicons repYFV-17D-GFP and repYFV-17D-Luc showed efficient replication and expression of the reporter genes. The yeast-based homologous recombination technique used in this study proved to be applicable for manipulation of the yellow fever virus genome in order to construct subgenomic replicons.

  20. A multimodality imaging model to track viable breast cancer cells from single arrest to metastasis in the mouse brain

    Science.gov (United States)

    Parkins, Katie M.; Hamilton, Amanda M.; Makela, Ashley V.; Chen, Yuanxin; Foster, Paula J.; Ronald, John A.

    2016-01-01

    Cellular MRI involves sensitive visualization of iron-labeled cells in vivo but cannot differentiate between dead and viable cells. Bioluminescence imaging (BLI) measures cellular viability, and thus we explored combining these tools to provide a more holistic view of metastatic cancer cell fate in mice. Human breast carcinoma cells stably expressing Firefly luciferase were loaded with iron particles, injected into the left ventricle, and BLI and MRI were performed on days 0, 8, 21 and 28. The number of brain MR signal voids (i.e., iron-loaded cells) on day 0 significantly correlated with BLI signal. Both BLI and MRI signals decreased from day 0 to day 8, indicating a loss of viable cells rather than a loss of iron label. Total brain MR tumour volume on day 28 also correlated with BLI signal. Overall, BLI complemented our sensitive cellular MRI technologies well, allowing us for the first time to screen animals for successful injections, and, in addition to MR measures of cell arrest and tumor burden, provided longitudinal measures of cancer cell viability in individual animals. We predict this novel multimodality molecular imaging framework will be useful for evaluating the efficacy of emerging anti-cancer drugs at different stages of the metastatic cascade. PMID:27767185

  1. Non-invasive quantification of brain tumor-induced astrogliosis

    Directory of Open Access Journals (Sweden)

    Baird Andrew

    2011-01-01

    Full Text Available Abstract Background CNS injury including stroke, infection, and tumor growth lead to astrogliosis, a process that involves upregulation of glial fibrillary acidic protein (GFAP in astrocytes. However, the kinetics of astrogliosis that is related to these insults (i.e. tumor is largely unknown. Results Using transgenic mice expressing firefly luciferase under the regulation of the GFAP promoter (GFAP-luc, we developed a model system to monitor astrogliosis upon tumor growth in a rapid, non-invasive manner. A biphasic induction of astrogliosis was observed in our xenograft model in which an early phase of activation of GFAP was associated with inflammatory response followed by a secondary, long-term upregulation of GFAP. These animals reveal GFAP activation with kinetics that is in parallel with tumor growth. Furthermore, a strong correlation between astrogliosis and tumor size was observed. Conclusions Our results suggest that non-invasive, quantitative bioluminescent imaging using GFAP-luc reporter animal is a useful tool to monitor temporal-spatial kinetics of host-mediated astrogliosis that is associated with glioma and metastatic brain tumor growth.

  2. Monitoring and quantitative assessment of tumor burden using in vivo bioluminescence imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.-C. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China); Hwang, Jeng-Jong [Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China)]. E-mail: jjhwang@ym.edu.tw; Ting, G. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China); Tseng, Y.-L. [Taiwan Liposome Company, Taipei 115, Taiwan (China); Wang, S.-J. [Department of Nuclear Medicine, Veterans General Hospital, Taipei 112, Taiwan (China); Whang-Peng, J. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China)

    2007-02-01

    In vivo bioluminescence imaging (BLI) is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating tumor growth. In this study, the kinetic of tumor growth has been assessed in C26 colon carcinoma bearing BALB/c mouse model. The ability of BLI to noninvasively quantitate the growth of subcutaneous tumors transplanted with C26 cells genetically engineered to stably express firefly luciferase and herpes simplex virus type-1 thymidine kinase (C26/tk-luc). A good correlation (R {sup 2}=0.998) of photon emission to the cell number was found in vitro. Tumor burden and tumor volume were monitored in vivo over time by quantitation of photon emission using Xenogen IVIS 50 and standard external caliper measurement, respectively. At various time intervals, tumor-bearing mice were imaged to determine the correlation of in vivo BLI to tumor volume. However, a correlation of BLI to tumor volume was observed when tumor volume was smaller than 1000 mm{sup 3} (R {sup 2}=0.907). {gamma} Scintigraphy combined with [{sup 131}I]FIAU was another imaging modality used for verifying the previous results. In conclusion, this study showed that bioluminescence imaging is a powerful and quantitative tool for the direct assay to monitor tumor growth in vivo. The dual reporter genes transfected tumor-bearing animal model can be applied in the evaluation of the efficacy of new developed anti-cancer drugs.

  3. Low levels of aflatoxin B1, ricin, and milk enhance recombinant protein production in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Reuven Rasooly

    Full Text Available Gene expression in transduced mammalian cells correlates with virus titer, but high doses of vector for gene therapy leads to toxicity in humans and in animals. Changing the optimal tissue culture medium by adding low levels of environmental stressors, such as 1 µM of the fungal toxin aflatoxin B1 (AFB1, 1 ng of the castor bean protein toxin ricin, or 1% reconstituted milk, enhances transcription and increases production of proteins in transduced mammalian cells as demonstrated by production of the following three recombinant proteins: firefly luciferase, β-galactosidase, and green fluorescent protein (GFP. Higher concentrations of the stress-producing substances damage the cells beyond recovery, resulting in inhibited gene expression and cell death. We also evaluated the effect of the stressor substances on the enhanced infectivity of virus. The presented findings extend methods for large-scale transient recombinant protein production in mammalian cells and suggest that it may be possible to reduce the cytotoxicity of the adenovirus by reducing the virus titer without adversely affecting gene expression levels.

  4. Enhancing the response of CALUX and CAFLUX cell bioassays for quantitative detection of dioxin-like compounds

    Institute of Scientific and Technical Information of China (English)

    BASTON; David; S.; KHAN; Elaine; SORRENTINO; Claudio; DENISON; Michael; S.

    2010-01-01

    Reporter genes produce a protein product in transfected cells that can be easily measured in intact or lysed cells and they have been extensively used in numerous basic and applied research applications.Over the past 10 years,reporter gene assays have been widely accepted and used for analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like compounds in various types of matrices,such as biological,environmental,food and feed samples,given that high-resolution instrumental analysis techniques are impractical for large-scale screening analysis.The most sensitive cell-based reporter gene bioassay systems developed are the mechanism-based CALUX(Chemically Activated Luciferase Expression) and CAFLUX(Chemically Activated Fluorescent Expression) bioassays,which utilize recombinant cell lines containing stably transfected dioxin(AhR) responsive firefly luciferase or enhanced green fluorescent protein(EGFP) reporter genes,respectively.While the current CALUX and CAFLUX bioassays are very sensitive,increasing their lower limit of sensitivity,magnitude of response and dynamic range for chemical detection would significantly increase their utility,particularly for those samples that contain low levels of dioxin-like HAHs(i.e.,serum) .In this study,we report that the addition of modulators of cell signaling pathways or modification of cell culture conditions results in significant improvement in the magnitude and overall responsiveness of the existing CALUX and CAFLUX cell bioassays.

  5. Gemcitabine upregulates ABCG2/BCRP and modulates the intracellular pharmacokinetic profiles of bioluminescence in pancreatic cancer cells.

    Science.gov (United States)

    Sun, Yue; Gu, Mancang; Zhu, Lixin; Liu, Junying; Xiong, Yang; Wei, Yinghui; Li, Fanzhu

    2016-03-01

    A lack of methods capable of exploring real-time intracellular drug deposition has since limited the investigation of gemcitabine-induced multidrug resistance in vitro and in vivo. Specifically, resistance induced by D-luciferin, a substrate of the breast cancer resistance protein (ABCG2/BCRP), has recently attracted clinical attention, but further investigation has been limited. Herein, the intracellular pharmacokinetic behavior of D-luciferin was investigated in pancreatic cancer cell lines in real time by using bioluminescence imaging. To achieve this feat, BxPC3 and Panc1 pancreatic cancer cells overexpressing firefly luciferase were treated with gemcitabine in a dose and time gradient manner in vitro. The intracellular pharmacokinetic profiles of each group were then determined through the acquisition of bioluminescent signal intensity of D-luciferin in cells. Simultaneously, key pharmacokinetic parameters including area under the curve, elimination rate constant (K), and mean resident time were calculated according to the noncompartment model. ABCG2 protein levels following gemcitabine treatment were detected through western blot, and gemcitabine showed no significant effect on luciferase activity over dimethyl sulfoxide (DMSO) as a control (P>0.05). However, gemcitabine significantly increased K values while suppressing area under the curve and mean resident time compared with DMSO (PBxPC3 and Panc1 cells in a dose-response manner. Advances made herein illustrate the versatility of the in-vitro bioluminescent model and its capability to observe the onset of chemoresistance in real time.

  6. P19 of Tomato Bushy Stunt Virus Suppresses RNA Silencing Induced by Short Hairpin RNA in Mammal Cells

    Institute of Scientific and Technical Information of China (English)

    Wei-xian CHEN; Juan CHEN; Zhen-zhen ZHANG; Ai-long HUANG

    2007-01-01

    To counteract the immune system in parasitic hosts, some viruses encode proteins to suppress the RNA interference (RNAi) effect. In this report, we established two RNAi systems to be easily observed with strong and obvious effect. The function of the P19 of tomato bushy stunt virus, which suppresses RNAi in mammal cells, was then studied using these two systems. Short hairpin RNAs targeting green fluorescence protein (pshRNA-GFP) and firefly luciferase (pshRNA-luc) were designed and inserted into a eukaryotic transcriptional vector pTZU6+1, respectively. The shRNA expressing vectors were co-transfected with plasmids containing the target gene with or without P19. The GFP expression level was assayed by fluorescence microscopy, Western blotting and RT-PCR. The luciferase expression level was analyzed by the dual-luciferase assay system. pshRNA designed in this study down-regulated the target gene specifically and efficiently, with a decrease of expression of both genes of about 70%, respectively. When P19 was introduced into the RNAi systems, the expression of both GFP and the luciferase were mostly recovered compared with the control groups. The RNAi systems of GFP and luciferase were constructed successfully, demonstrating that P19 of tomato bushy stunt virus has the ability to counteract the RNAi effect induced by shRNA in mammal cells.

  7. In Vivo Follow-up of Brain Tumor Growth via Bioluminescence Imaging and Fluorescence Tomography

    Directory of Open Access Journals (Sweden)

    Coralie Genevois

    2016-10-01

    Full Text Available Reporter gene-based strategies are widely used in experimental oncology. Bioluminescence imaging (BLI using the firefly luciferase (Fluc as a reporter gene and d-luciferin as a substrate is currently the most widely employed technique. The present paper compares the performances of BLI imaging with fluorescence imaging using the near infrared fluorescent protein (iRFP to monitor brain tumor growth in mice. Fluorescence imaging includes fluorescence reflectance imaging (FRI, fluorescence diffuse optical tomography (fDOT, and fluorescence molecular Imaging (FMT®. A U87 cell line was genetically modified for constitutive expression of both the encoding Fluc and iRFP reporter genes and assayed for cell, subcutaneous tumor and brain tumor imaging. On cultured cells, BLI was more sensitive than FRI; in vivo, tumors were first detected by BLI. Fluorescence of iRFP provided convenient tools such as flux cytometry, direct detection of the fluorescent protein on histological slices, and fluorescent tomography that allowed for 3D localization and absolute quantification of the fluorescent signal in brain tumors.

  8. Role of Superoxide in Bioluminescence†%超氧负离子在生物发光中的作用

    Institute of Scientific and Technical Information of China (English)

    罗艳玲; 刘亚军

    2015-01-01

    Following the introduction on reactive oxygen species and superoxide, this review summarized the role of supe­roxide in bioluminescence, and elaborated theoretical and experimental research progress of super­ oxide reaction in several different bioluminescent systems. The role of superoxide in bioluminescence was de­ scribed in firefly, bacteria, fungi and dinoflagellate bioluminescent processes. The production, function and reaction of superoxide in bacteria bioluminescence was explained in details according to our recent study.%活性氧物种和超氧负离子是生物体内的重要物质,本文通过超氧负离子在生物发光反应中的作用,针对几种不同的典型生物发光体系,综述了超氧负离子参与发光反应的相关理论和实验研究进展。

  9. In vivo Brain Delivery of v-myc Overproduced Human Neural Stem Cells via the Intranasal Pathway: Tumor Characteristics in the Lung of a Nude Mouse

    Directory of Open Access Journals (Sweden)

    Eun Seong Lee

    2015-01-01

    Full Text Available We aimed to monitor the successful brain delivery of stem cells via the intranasal route and to observe the long-term consequence of the immortalized human neural stem cells in the lungs of a nude mouse model. Stably immortalized HB1.F3 human neural stem cells with firefly luciferase gene (F3-effluc were intranasally delivered to BALB/c nude mice. Bioluminescence images were serially acquired until 41 days in vivo and at 4 hours and 41 days ex vivo after intranasal delivery. Lungs were evaluated by histopathology. After intranasal delivery of F3-effluc cells, the intense in vivo signals were detected in the nasal area, migrated toward the brain areas at 4 hours (4 of 13, 30.8%, and gradually decreased for 2 days. The brain signals were confirmed by ex vivo imaging (2 of 4, 50%. In the mice with initial lung signals (4 of 9, 44.4%, the lung signals disappeared for 5 days but reappeared 2 weeks later. The intense lung signals were confirmed to originate from the tumors in the lungs formed by F3-effluc cells by ex vivo imaging and histopathology. We propose that intranasal delivery of immortalized stem cells should be monitored for their successful delivery to the brain and their tumorigenicity longitudinally.

  10. Light Emission Requires Exposure to the Atmosphere in Ex Vivo Bioluminescence Imaging

    Directory of Open Access Journals (Sweden)

    Yusuke Inoue

    2006-04-01

    Full Text Available The identification of organs bearing luciferase activity by in vivo bioluminescence imaging (BLI is often difficult, and ex vivo imaging of excised organs plays a complementary role. This study investigated the importance of exposure to the atmosphere in ex vivo BLI. Mice were inoculated with murine pro-B cell line Ba/F3 transduced with firefly luciferase and p190 BCR-ABL. They were killed following in vivo BLI, and whole-body imaging was done after death and then after intraperitoneal air injection. In addition, the right knee was exposed and imaged before and after the adjacent bones were cut. Extensive light signals were seen on in vivo imaging. The luminescence disappeared after the animal was killed, and air injection restored the light emission from the abdomen only, suggesting a critical role of atmospheric oxygen in luminescence after death. Although no substantial light signal at the right knee was seen before bone cutting, light emission was evident after cutting. In conclusion, in ex vivo BLI, light emission requires exposure to the atmosphere. Bone destruction is required to demonstrate luciferase activity in the bone marrow after death.

  11. Functional imaging of interleukin 1 beta expression in inflammatory process using bioluminescence imaging in transgenic mice

    Directory of Open Access Journals (Sweden)

    Liu Zhihui

    2008-08-01

    Full Text Available Abstract Background Interleukin 1 beta (IL-1β plays an important role in a number of chronic and acute inflammatory diseases. To understand the role of IL-1β in disease processes and develop an in vivo screening system for anti-inflammatory drugs, a transgenic mouse line was generated which incorporated the transgene firefly luciferase gene driven by a 4.5-kb fragment of the human IL-1β gene promoter. Luciferase gene expression was monitored in live mice under anesthesia using bioluminescence imaging in a number of inflammatory disease models. Results In a LPS-induced sepsis model, dramatic increase in luciferase activity was observed in the mice. This transgene induction was time dependent and correlated with an increase of endogenous IL-1β mRNA and pro-IL-1β protein levels in the mice. In a zymosan-induced arthritis model and an oxazolone-induced skin hypersensitivity reaction model, luciferase expression was locally induced in the zymosan injected knee joint and in the ear with oxazolone application, respectively. Dexamethasone suppressed the expression of luciferase gene both in the acute sepsis model and in the acute arthritis model. Conclusion Our data suggest that the transgenic mice model could be used to study transcriptional regulation of the IL-1β gene expression in the inflammatory process and evaluation the effect of anti-inflammatory drug in vivo.

  12. Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo

    Directory of Open Access Journals (Sweden)

    Rasko John EJ

    2010-11-01

    Full Text Available Abstract Live animal imaging is becoming an increasingly common technique for accurate and quantitative assessment of tumor burden over time. Bioluminescence imaging systems rely on a bioluminescent signal from tumor cells, typically generated from expression of the firefly luciferase gene. However, previous reports have suggested that either a high level of luciferase or the resultant light reaction produced upon addition of D-luciferin substrate can have a negative influence on tumor cell growth. To address this issue, we designed an expression vector that allows simultaneous fluorescence and luminescence imaging. Using fluorescence activated cell sorting (FACS, we generated clonal cell populations from a human breast cancer (MCF-7 and a mouse melanoma (B16-F10 cell line that stably expressed different levels of luciferase. We then compared the growth capabilities of these clones in vitro by MTT proliferation assay and in vivo by bioluminescence imaging of tumor growth in live mice. Surprisingly, we found that neither the amount of luciferase nor biophotonic activity was sufficient to inhibit tumor cell growth, in vitro or in vivo. These results suggest that luciferase toxicity is not a necessary consideration when designing bioluminescence experiments, and therefore our approach can be used to rapidly generate high levels of luciferase expression for sensitive imaging experiments.

  13. Molecular Imaging of Bone Marrow Mononuclear Cell Survival and Homing in Murine Peripheral Artery Disease

    Science.gov (United States)

    van der Bogt, Koen E.A.; Hellingman, Alwine A.; Lijkwan, Maarten A.; Bos, Ernst-Jan; de Vries, Margreet R.; Fischbein, Michael P.; Quax, Paul H.; Robbins, Robert C.; Hamming, Jaap F.; Wu, Joseph C.

    2013-01-01

    Introduction Bone marrow mononuclear cell (MNC) therapy is a promising treatment for peripheral artery disease (PAD). This study aims to provide insight into cellular kinetics using molecular imaging following different transplantation methods. Methods and Results MNCs were isolated from F6 transgenic mice (FVB background) that express firefly luciferase (Fluc) and green fluorescence protein (GFP). Male FVB and C57Bl6 mice (n=50) underwent femoral artery ligation and were randomized into 4 groups receiving: (1) single intramuscular (i.m.) injection of 2×106 MNC; (2) four weekly i.m. injections of 5×105 MNC; (3) 2×106 MNCs intravenously (i.v.); and (4) PBS. Cellular kinetics, measured by in vivo bioluminescence imaging (BLI), revealed near-complete donor cell death 4 weeks after i.m. transplantation. Following i.v. transplantation, BLI monitored cells homed in on the injured area in the limb, as well as to the liver, spleen, and bone marrow. Ex vivo BLI showed presence of MNCs in the scar tissue and adductor muscle. However, no significant effects on neovascularisation were observed as monitored by Laser-Doppler-Perfusion-Imaging and histology. Conclusion This is one of the first studies to assess kinetics of transplanted MNCs in PAD using in vivo molecular imaging. MNC survival is short lived and MNCs do not significantly stimulate perfusion in this model. PMID:22239892

  14. Optimized extract preparation methods and reaction conditions for improved yeast cell-free protein synthesis.

    Science.gov (United States)

    Hodgman, C Eric; Jewett, Michael C

    2013-10-01

    Cell-free protein synthesis (CFPS) has emerged as a powerful platform technology to help satisfy the growing demand for simple, affordable, and efficient protein production. In this article, we describe a novel CFPS platform derived from the popular bio-manufacturing organism Saccharomyces cerevisiae. By developing a streamlined crude extract preparation protocol and optimizing the CFPS reaction conditions we were able to achieve active firefly luciferase synthesis yields of 7.7 ± 0.5 µg mL(-1) with batch reactions lasting up to 2 h. This duration of synthesis is the longest ever reported for a yeast CFPS batch reaction. Furthermore, by removing extraneous processing steps and eliminating expensive reagents from the cell-free reaction, we have increased relative product yield (µg protein synthesized per $ reagent cost) over an alternative commonly used method up to 2000-fold from ∼2 × 10(-4) to ∼4 × 10(-1)  µg $(-1) , which now puts the yeast CPFS platform on par with other eukaryotic CFPS platforms commercially available. Our results set the stage for developing a yeast CFPS platform that provides for high-yielding and cost-effective expression of a variety of protein therapeutics and protein libraries.

  15. A New Indicator Cell Line Established to Monitor Bovine Foamy Virus Infection

    Institute of Scientific and Technical Information of China (English)

    Hong-yan Guo; Zhi-bin Liang; Yue Li; Juan Tan; Qi-min Chen; Wen-tao Qiao

    2011-01-01

    In order to improve the accuracy for quantitating the bovine foamy virus(BFV)in vitro,we developed a baby hamster kidney cell(BHK)-21-derived indicator cell line containing a plasmid that encodes the firefly luciferase driven by the BFV long terminal repeat promoter(LTR,from -7 to 1012). The BFV titer could be determined by detecting the luciferase expression since the viral trans-activator BTas protein activates the promoter activity of the LTR. One clone,designated BFVL,was selected from ten neomycin-resistant clones.BFVL showed a specific and inducible dose-and time-dependent luciferase activity in response to BFV infection.Although the changes in luciferase activity of BFVL peaked at 84 h post infection,it was possible to differentiate infected and uninfected cells at 48 h post infection. A linear relationship was established between the multiplicity of infection(MOI)of BFV and the activated ratio of luciferase expression in BFVL. Moreover,the sensitivity of the BFVL-based assay for detecting infectious BFV was 10,000 times higher than the conventional CPE-based assay at 48 h post infection. These findings suggest that the BFVL-based assay is rapid,easy,sensitive,quantitative and specific for detection of BFV infection.

  16. Light emission miracle in the sea and preeminent applications of bioluminescence in recent new biotechnology.

    Science.gov (United States)

    Sharifian, Sana; Homaei, Ahmad; Hemmati, Roohullah; Khajeh, Khosro

    2017-07-01

    Bioluminescence is referred to the light emission by a living organism due to a specific biochemical reaction. This interesting feature of the organisms could highly influences behavioral and ecosystem dynamics. Luminescence, mostly observed in marine species, is generally higher in deep-living genera than in benthic or shallow organisms. However, among creatures living in land, fireflies, beetles, springtails and fungi have shown some bioluminescent activities. Classically, the emission of light is catalyzed by luciferase from a substrate. Interestingly, light-emitting organisms are more abundant and widespread in marine than terrestrial environments. Novel tools derived from understanding bioluminescent reactions have led to countless valuable applications in modern biotechnology and biochemical engineering. Here, we overview some main properties bioluminescence in marine organism from bacteria to fishes following the latest advances and new discoveries of state-of-the-art bioluminescent tools in molecular biology, bioluminescent bioassays and imaging. The overview showed available and wide biotechnological tools of bioluminescence take advantage of its high detectability, high sensitive, low toxic and quantum efficiency which make wide usage as reporter of many biological functions in different fields, such as studying bacterial pathogens, ecotoxicology, food toxicity, tracking cells of interest in vivo, protein-protein interactions, gene expression and circadian rhythms. With the recent invention of luminescent reporters, future possibilities for the development of additional reporter applications are promising. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Molecular basis for the blue bioluminescence of the Australian glow-worm Arachnocampa richardsae (Diptera: Keroplatidae).

    Science.gov (United States)

    Trowell, Stephen C; Dacres, Helen; Dumancic, Mira M; Leitch, Virginia; Rickards, Rodney W

    2016-09-16

    Bioluminescence is the emission of visible light by living organisms. Here we describe the isolation and characterisation of a cDNA encoding a MW ≈ 59,000 Da luciferase from the Australian glow-worm, Arachnocampa richardsae. The enzyme is a member of the acyl-CoA ligase superfamily and produces blue light on addition of D-luciferin. These results are contrary to earlier reports (Lee, J., Photochem Photobiol 24, 279-285 (1976), Viviani, V. R., Hastings, J. W. & Wilson, T., Photochem Photobiol 75, 22-27 (2002)), which suggested glow-worm luciferase has MW ≈ 36,000 Da and is unreactive with beetle luciferin. There are more than 2000 species of firefly, which all produce emissions from D-luciferin in the green to red regions of the electromagnetic spectrum. Although blue-emitting luciferases are known from marine organisms, they belong to different structural families and use a different substrate. The observation of blue emission from a D-luciferin-using enzyme is therefore unprecedented.

  18. A New Biobjective Model to Optimize Integrated Redundancy Allocation and Reliability-Centered Maintenance Problems in a System Using Metaheuristics

    Directory of Open Access Journals (Sweden)

    Shima MohammadZadeh Dogahe

    2015-01-01

    Full Text Available A novel integrated model is proposed to optimize the redundancy allocation problem (RAP and the reliability-centered maintenance (RCM simultaneously. A system of both repairable and nonrepairable components has been considered. In this system, electronic components are nonrepairable while mechanical components are mostly repairable. For nonrepairable components, a redundancy allocation problem is dealt with to determine optimal redundancy strategy and number of redundant components to be implemented in each subsystem. In addition, a maintenance scheduling problem is considered for repairable components in order to identify the best maintenance policy and optimize system reliability. Both active and cold standby redundancy strategies have been taken into account for electronic components. Also, net present value of the secondary cost including operational and maintenance costs has been calculated. The problem is formulated as a biobjective mathematical programming model aiming to reach a tradeoff between system reliability and cost. Three metaheuristic algorithms are employed to solve the proposed model: Nondominated Sorting Genetic Algorithm (NSGA-II, Multiobjective Particle Swarm Optimization (MOPSO, and Multiobjective Firefly Algorithm (MOFA. Several test problems are solved using the mentioned algorithms to test efficiency and effectiveness of the solution approaches and obtained results are analyzed.

  19. Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Koehorst-van Putten, Herma J J; Wolters, Anne-Marie A; Pereira-Bertram, Isolde M; van den Berg, Hans H J; van der Krol, Alexander R; Visser, Richard G F

    2012-12-01

    In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,167 bp) was cloned into binary vectors to drive expression of the firefly luciferase gene. Cassava cultivar Adira 4 was transformed with this construct or a control construct in which the luciferase gene was cloned behind the 35S promoter. Luciferase activity was measured in leaves, stems, roots and tuberous roots. As expected, the 35S promoter induced luciferase activity in all organs at similar levels, whereas the GBSSI promoter showed very low expression in leaves, stems and roots, but very high expression in tuberous roots. These results show that the cassava GBSSI promoter is an excellent candidate to achieve tuberous root-specific expression in cassava.

  20. Optogenetic inhibition of neurons by internal light production

    Directory of Open Access Journals (Sweden)

    Benjamin eLand

    2014-04-01

    Full Text Available Optogenetics is an extremely powerful tool for selective neuronal activation/inhibition and dissection of neural circuits. However, a limitation of in vivo optogenetics is that an animal must be tethered to an optical fiber for delivery of light. Here, we describe a new method for in vivo, optogenetic inhibition of neural activity using an internal, animal-generated light source based on firefly luciferase. Two adeno-associated viruses encoding luciferase were tested and both produced concentration-dependent light after administration of the substrate, luciferin. Mice were co-infected with halorhodopsin- and luciferase-expressing viruses in the striatum, and luciferin administration significantly reduced Fos activity compared to control animals infected with halorhodopsin only. Recordings of neuronal activity in behaving animals confirmed that firing was greatly reduced after luciferin administration. Finally, amphetamine-induced locomotor activity was reduced in halorhodopsin/luciferase mice pre-injected with luciferin compared to controls. This demonstrates that virally encoded luciferase is able to generate sufficient light to activate halorhodopsin and suppress neural activity and change behavior. This approach could be used to generate inhibition in response to activation of specific molecular pathways.