WorldWideScience

Sample records for mega plasmid resident

  1. Cereulide synthetase gene cluster from emetic Bacillus cereus: Structure and location on a mega virulence plasmid related to Bacillus anthracis toxin plasmid pXO1

    Wagner Martin

    2006-03-01

    Full Text Available Abstract Background Cereulide, a depsipeptide structurally related to valinomycin, is responsible for the emetic type of gastrointestinal disease caused by Bacillus cereus. Recently, it has been shown that this toxin is produced by a nonribosomal peptide synthetase (NRPS, but its exact genetic organization and biochemical synthesis is unknown. Results The complete sequence of the cereulide synthetase (ces gene cluster, which encodes the enzymatic machinery required for the biosynthesis of cereulide, was dissected. The 24 kb ces gene cluster comprises 7 CDSs and includes, besides the typical NRPS genes like a phosphopantetheinyl transferase and two CDSs encoding enzyme modules for the activation and incorporation of monomers in the growing peptide chain, a CDS encoding a putative hydrolase in the upstream region and an ABC transporter in the downstream part. The enzyme modules responsible for incorporation of the hydroxyl acids showed an unusual structure while the modules responsible for the activation of the amino acids Ala and Val showed the typical domain organization of NRPS. The ces gene locus is flanked by genetic regions with high homology to virulence plasmids of B. cereus, Bacillus thuringiensis and Bacillus anthracis. PFGE and Southern hybridization showed that the ces genes are restricted to emetic B. cereus and indeed located on a 208 kb megaplasmid, which has high similarities to pXO1-like plasmids. Conclusion The ces gene cluster that is located on a pXO1-like virulence plasmid represents, beside the insecticidal and the anthrax toxins, a third type of B. cereus group toxins encoded on megaplasmids. The ces genes are restricted to emetic toxin producers, but pXO1-like plasmids are also present in emetic-like strains. These data might indicate the presence of an ancient plasmid in B. cereus which has acquired different virulence genes over time. Due to the unusual structure of the hydroxyl acid incorporating enzyme modules of Ces

  2. Resident enhanced repair: novel repair process action on plasmid DNA transformed into Escherichia coli K-12

    The survival of UV-irradiated DNA of plasmid NTP16 was monitored after its transformation into recipient cells containing an essentially homologous undamaged plasmid, pLV9. The presence of pLV9 resulted in a substantial increase in the fraction of damaged NTP16 molecules which survived in the recipient cells. This enhanced survival requires the host uvrA+ and uvrB+ gene products, but not the host recA+ gene product. The requirement for both homologous DNA and the uvrA+ gene products suggests that a novel repair process may act on plasmid DNA. Possible mechanisms for this process are considered

  3. Examination of residence time and its relevance to water quality within a coastal mega-structure: The Palm Jumeirah Lagoon

    Cavalcante, Geórgenes H.; Kjerfve, Björn; Feary, David A.

    2012-10-01

    SummaryA numerical modeling study was carried out to compute average residence time in the semi-enclosed lagoon formed by the man-made island Palm Jumeirah (Dubai, United Arab Emirates), termed Palm Jumeirah Lagoon (PJL). The PJL encompasses a main island axis with 17 'fronds' radiating from this axis, all encapsulated within a semi-circular breakwater system. A coupled hydrodynamic and solute transport model was developed for the waters of the PJL, based on depth-integrated conservation equations. Numerical model predictions were then verified against a set of field-measured hydrodynamic data. Model-predicted water elevations and velocities were in good agreement with field measurements. Residence times for this tidal dominated system were investigated through numerical experiments using a conservative tracer as a surrogate. The results indicated that average residence time varied spatially throughout the PJL depending on tidal flushing. Average residence time was unequally distributed throughout the PJL, with the eastern side showing higher flushing times than the western side. In addition, there were also differences between sections of the PJL in average residence time of a tracer: between frond tips and the surrounding breakwater the tracer was reduced to 30-40% of its original value after approximately 1 week, while a tracer placed between the fronds was reduced to 30-40% of its value after 20 days. The findings of this research provide vital information for understanding the water transport process in this man-made lagoon, and will be important in assessing the potential impact on coastal water quality conditions in coastal developments within the Middle East.

  4. Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens.

    Hooykaas, P J; Den Dulk-Ras, H; Ooms, G.; Schilperoort, R.A.

    1980-01-01

    Transfer of octopine Ti plasmids to strains already carrying an octopine Ti plasmid was found to occur at the same (high) frequency as transfer to Ti plasmid lacking recipients, showing that resident Ti plasmids do not exhibit entry exclusion towards incoming Ti plasmids. The resident octopine Ti plasmid was lost by the recipient after the entrance of the incoming Ti plasmid, which is indicative of the incompatibility between the Ti plasmids. Octopine Ti plasmids were found to become establis...

  5. Plasmid-mediated gene transfer between insect-resident bacteria, Enterobacter cloacae, and plant-epiphytic bacteria, Erwinia herbicola, in guts of silkworm larvae.

    Watanabe, K; Sato, M

    1998-11-01

    Five strains of Enterobacter cloacae isolated from several species of plants and insects were able to grow in the guts of silkworm larvae. A much larger population of Ent. cloacae strains was detected in the insect guts and feces collected 3 and 6 days than in samples collected 1 day after feeding artificial diets contaminating these bacteria. Furthermore, insect-origin strains of Ent. cloacae were mated with a donor strain, epiphytic Erwinia herbicola, harboring RSF1010 and pBPW1::Tn7 plasmids in the insect guts by introducing these bacteria through separate artificial diets administered at different times. A number of transconjugants, Ent. cloacae strains which had acquired RSF1010 plasmid, were detected from guts and fecal samples at transfer frequencies of 10(-2) to 10(-3) per recipient. Thus, gene transfer between epiphytic Er. herbicola and insect-resident Ent. cloacae strains in the insect guts was confirmed. These findings may provide significant information about the role of "in insecta mating" in the evolution of these bacteria. PMID:9767717

  6. Computerized mega code recording.

    Burt, T W; Bock, H C

    1988-04-01

    A system has been developed to facilitate recording of advanced cardiac life support mega code testing scenarios. By scanning a paper "keyboard" using a bar code wand attached to a portable microcomputer, the person assigned to record the scenario can easily generate an accurate, complete, timed, and typewritten record of the given situations and the obtained responses. PMID:3354937

  7. Mega Key Authentication Mechanism

    Kloss, Guy

    2016-01-01

    For secure communication it is not just sufficient to use strong cryptography with good and strong keys, but to actually have the assurance, that the keys in use for it are authentic and from the contact one is expecting to communicate with. Without that, it is possible to be subject to impersonation or man-in-the-middle (MitM) attacks. Mega meets this problem by providing a hierarchical authentication mechanism for contacts and their keys. To avoid any hassle when using multiple types of key...

  8. Aircushion Supported Mega-Floaters

    Van Kessel, J.L.F.

    2010-01-01

    The increase of the global population and expanding coastal mega-cities will necessitate an innovative pursuit of the utilization of the ocean space in which mega-floaters will play an important role in the future. These types of structures are very large floating artificial islands that can be used

  9. Photon detector for MEGA

    During this past August and September, we had beam time at LAMPF for an engineering study of the second prototype cylindrical photon pair spectrometer for MEGA. All of the scintillators in the detector, a total of 40, and 40% of the drift chamber cells were instrumented for this run. The main photon arm activities during the run were to compare event patterns in the chamber to our Monte Carlo generated events, to study the trigger rate and to determine the background rates in the various detector elements. At low beam intensity, the event patterns from the chamber closely resembled those generated from the Monte Carlo. The background rates in the scintillators and the innermost drift chamber layer were close to those anticipated from previous studies. However the background rates in the outer two drift chamber layers were substantially higher than we had expected. This high rate was traced to low energy photons interacting with field and sense wires. The trigger studies during the run have led us to consider alternative strategies including two different first stage triggers and a second stage trigger. The combination of the second stage trigger with either of the two first stage triggers is expected to provide good detection efficiency while keeping the raw trigger rate below that required by the data acquisition system. Detailed discussions of both the background and trigger studies are discussed in this report. Since the run, our work on methods to obtain the z-position in the photon arm drift chambers has continued. Our goal is to obtain the z coordinate to 5 mm FWHM. At this level, the z uncertainty makes a negligible contribution to the overall photon energy resolution and only a small contribution to the angular resolution. We have been studying an option which uses delay lines to provide a direct z determination. The results of our study are discussed in this report

  10. Mega-constellations Issues

    Bastida Virgili, Benjamin; Krag, Holger

    2016-07-01

    increase drastically. In this study, we report the detected issues of such a mega-constellation traffic, and we analyse the response of the space object population to the introduction of a large constellation conforming to the post-mission disposal guideline with differing levels of success and with different disposal orbit options.

  11. Mega cultural events: Does attendance affect residents’ perceptions of a city’s identity?

    Santos, José Freitas; Vareiro, Laurentina; Remoaldo, Paula Cristina Almeida; Ribeiro, J. Cadima

    2015-01-01

    Events are frequently planned with a goal of attracting tourists to a destination. However, studies about the impact of a mega cultural event on residents’ identity are scarce. This research is based on the premise that hosting a mega cultural event can, to a significant degree, change a few of the attributes of the city’s identity as it is perceived by its residents. Specifically, the objective of the study is to identify the attributes of the city and compare the differences found between d...

  12. Five Predatory Mega-Journals: A Review

    Beall, Jeffrey

    2013-01-01

    Mega-journals such as PLOS One are an emerging and successful model of scholarly Open Access publishing. Unfortunately, some new, questionable journals have appeared that are copying the megajournal model. This review covers the five predatory mega-journals British Journal of Science, International Journal of Current Research, International Journal of Science and Advanced Technology (IJSAT), International Journal of Sciences (IJSciences), and World Journal of Science and Technology. Each of t...

  13. Mega-supramolecules for safer, cleaner fuel

    Kornfield, Julie

    Guided by the statistical mechanics of ring-chain equilibrium, we designed and synthesized polymers that self-assemble into ``mega-supramolecules'' (>=5,000 kg/mol) at low concentration (400 kg/mol) and end-association strength is optimal (16-18kT). Hydrocarbon liquid fuels are the world's dominant power source (34% of global energy consumption). Transportation relies heavily on such liquids, presenting the risk of explosive post-impact fires. The collapse of the World Trade Center on September 11, 2001 inspired us to revisit polymers for mist control to mitigate post-impact fuel explosions. Rheological and both light and neutron scattering measurements of long end-functional polymers having polycyclooctadiene backbones and acid or amine end groups verify formation of mega-supramolecules. Post-impact flame propagations experiments show that mega-supramolecules control misting. Turbulent flow measurements show that mega-supramolecules reduce drag like ultra-long covalent polymers. With individual building blocks short enough to avoid hydrodynamic chain scission (400filters without degradation. Mega-supramolecules had no adverse effect on power output, fuel efficiency or emissions in diesel engines. In fact, they gave a 12% reduction in diesel soot. Thus, long end-associative polymers may open the way to fuel additives that reduce pollution and improve transportation safety and security.

  14. Plasmid segregation mechanisms

    Ebersbach, Gitte; Gerdes, Kenn; Charbon, Gitte Ebersbach

    2005-01-01

    Bacterial plasmids encode partitioning (par) loci that ensure ordered plasmid segregation prior to cell division. par loci come in two types: those that encode actin-like ATPases and those that encode deviant Walker-type ATPases. ParM, the actin-like ATPase of plasmid R1, forms dynamic filaments...... that segregate plasmids paired at mid-cell to daughter cells. Like microtubules, ParM filaments exhibit dynamic instability (i.e., catastrophic decay) whose regulation is an important component of the DNA segregation process. The Walker box ParA ATPases are related to MinD and form highly dynamic, oscillating...... filaments that are required for the subcellular movement and positioning of plasmids. The role of the observed ATPase oscillation is not yet understood. However, we propose a simple model that couples plasmid segregation to ParA oscillation. The model is consistent with the observed movement...

  15. SPP1-mediated plasmid transduction.

    Canosi, U; Lüder, G; Trautner, T A

    1982-01-01

    The virulent Bacillus subtilis phage SPP1 transduces plasmid DNA. Plasmid-transducing phages contain only plasmid DNA. Such DNA represents a concatemer of monomeric plasmid molecules with the molecular weight of mature SPP1 DNA. Biological parameters of plasmid transduction are described.

  16. Indian manpower for mega nuclear project

    2003-01-01

    "India is supplying critical scientific manpower and high-tech components needed for building a Large Hadron Collider (LHC) - an accelerator used in particle physics research - a mega scientific project of the European Organisation for Nuclear Research (CERN) worth billions of dollars" (1/2 page).

  17. About urban mega regions : knowns and unknowns

    Yusuf, Shahid

    2007-01-01

    Mega urban regions are not a passing phenomenon. They are likely to persist and to enlarge their economic footprints because they benefit from the advantages of market scale, agglomeration economies, location, and the increasing concentration of talented workers. Metropolitan regions which are polycentric, relatively well managed, and have invested heavily in transport infrastructure are able ...

  18. Construction and Use of Flow Cytometry Optimized Plasmid-Sensor Strains

    Bahl, Martin Iain; Oregaard, Gunnar; Sørensen, Søren Johannes;

    2009-01-01

    Determining the stability of plasmids in bacterial populations is traditionally performed by isolating a large number of clones followed by screening for the presence of plasmids by replica transfer to plasmid-selective agar plates. This is often a laborious task, especially when the intrinsic...... stability of the plasmid is high. The method presented here relies on a phenotypic (green fluorescence protein) marker, which is switched on if the host bacteria loses the residing plasmid. The incorporation of flow cytometry for single-cell detection and discrimination between plasmid-free and plasmid......-harboring cells in a bacterial population facilitates a very high throughput of cells and thus provides excellent sensitivity and statistics toward detecting even very low levels of plasmid instability....

  19. The development of plasmid-free strains of Agrobacterium tumefaciens by using incompatibility with a Rhizobium meliloti plasmid to eliminate pAtC58.

    Hynes, M F; Simon, R; Pühler, A

    1985-03-01

    Agrobacterium tumefaciens strains LBA275 and LBA290 were cured of their cryptic plasmid pAtC58 by the introduction of the Rhizobium meliloti plasmid pRme41a, which is incompatible with pAtC58. pRme41a and pTiC58, the resident Ti plasmid of LBA275, were subsequently eliminated by growth at supraoptimal temperature (40 degrees C). The resulting plasmid-free Agrobacterium strains, UBAPF1 and UBAPF2, have proved extremely useful for the study of Rhizobium plasmids. The loss of the cryptic plasmid pAtC58 has no effect on the tumor-forming ability of the Agrobacterium strains; when the Ti plasmid is present, normal tumors are formed on Kalanchoe daigremontiana. PMID:4001194

  20. Overlap extension PCR cloning: a simple and reliable way to create recombinant plasmids.

    Bryksin, Anton V; Matsumura, Ichiro

    2010-06-01

    Here we describe a straightforward, efficient, and reliable way to clone an insert of choice into a plasmid of choice without restriction endonucleases or T4 DNA ligase. Chimeric primers containing plasmid sequence at the 5' ends and insert sequence at the 3' ends were used to PCR-amplify insertion sequences of various sizes, namely the genes for GFP (gfp), beta-d-glucuronidase (gusA), and beta-galactosidase (lacZ), as well as the entire luxABCDE operon. These inserts were employed as mega-primers in a second PCR with a circular plasmid template. The original plasmid templates were then destroyed in restriction digests with DpnI, and the overlap extension PCR products were used to transform competent Escherichia coli cells. Phusion DNA polymerase was used for the amplification and fusion reactions, so both reactions were easy to monitor and optimize. PMID:20569222

  1. Vishal Mega-Mart- An Overview

    Shikha Gupta; Preeti Khatri; Kapil Gulati; Santosh Chauhan

    2010-01-01

    In the background of high consumerism and income of the urban consumers, in recent year, a number of companies have expressed their interest towards retail sector outlets. As a result, numbers of shopping malls have started their operations in metro and urban areas. Pantaloon, big bazaar, Vishal Mega Mart, Reliance Fresh are the best known examples of retail sector outlets in India. Retailing is the interface between the producer and the individual consumer buying for personal consumption. Th...

  2. Knowledge Discovery in Mega-Spectra Archives

    Škoda, Petr; Bromová, P.; Lopatovský, L.; Palička, V.; Vážný, J.

    San Francisco: Astronomical Society of the Pacific, 2015, s. 87-90. (ASP Conference Series. 495). ISBN 9781583818749. [Astronomical Data Analysis Software and Systems /24./. Calgary (CA), 05.10.2014-09.10.2014] R&D Projects: GA ČR GA13-08195S Institutional support: RVO:67985815 Keywords : mega-spectra archives * machine learning techniques Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  3. Overlap extension PCR cloning: a simple and reliable way to create recombinant plasmids

    Bryksin, Anton V.; Matsumura, Ichiro

    2010-01-01

    Here we describe a straightforward, efficient, and reliable way to clone an insert of choice into a plasmid of choice without restriction endonucleases or T4 DNA ligase. Chimeric primers containing plasmid sequence at the 5′ ends and insert sequence at the 3′ ends were used to PCR-amplify insertion sequences of various sizes, namely the genes for GFP (gfp), β-D-glucuronidase (gusA), and β-galactosidase (lacZ), as well as the entire luxABCDE operon. These inserts were employed as mega-primers ...

  4. Using Mahalanobis distance to compare genomic signatures between bacterial plasmids and chromosomes

    Suzuki, Haruo; Sota, Masahiro; Brown, Celeste J.; Top, Eva M.

    2008-01-01

    Plasmids are ubiquitous mobile elements that serve as a pool of many host beneficial traits such as antibiotic resistance in bacterial communities. To understand the importance of plasmids in horizontal gene transfer, we need to gain insight into the ‘evolutionary history’ of these plasmids, i.e. the range of hosts in which they have evolved. Since extensive data support the proposal that foreign DNA acquires the host's nucleotide composition during long-term residence, comparison of nucleoti...

  5. Plasmids encoding therapeutic agents

    Keener, William K.

    2007-08-07

    Plasmids encoding anti-HIV and anti-anthrax therapeutic agents are disclosed. Plasmid pWKK-500 encodes a fusion protein containing DP178 as a targeting moiety, the ricin A chain, an HIV protease cleavable linker, and a truncated ricin B chain. N-terminal extensions of the fusion protein include the maltose binding protein and a Factor Xa protease site. C-terminal extensions include a hydrophobic linker, an L domain motif peptide, a KDEL ER retention signal, another Factor Xa protease site, an out-of-frame buforin II coding sequence, the lacZ.alpha. peptide, and a polyhistidine tag. More than twenty derivatives of plasmid pWKK-500 are described. Plasmids pWKK-700 and pWKK-800 are similar to pWKK-500 wherein the DP178-encoding sequence is substituted by RANTES- and SDF-1-encoding sequences, respectively. Plasmid pWKK-900 is similar to pWKK-500 wherein the HIV protease cleavable linker is substituted by a lethal factor (LF) peptide-cleavable linker.

  6. Toxin plasmids of Clostridium perfringens.

    Li, Jihong; Adams, Vicki; Bannam, Trudi L; Miyamoto, Kazuaki; Garcia, Jorge P; Uzal, Francisco A; Rood, Julian I; McClane, Bruce A

    2013-06-01

    In both humans and animals, Clostridium perfringens is an important cause of histotoxic infections and diseases originating in the intestines, such as enteritis and enterotoxemia. The virulence of this Gram-positive, anaerobic bacterium is heavily dependent upon its prolific toxin-producing ability. Many of the ∼16 toxins produced by C. perfringens are encoded by large plasmids that range in size from ∼45 kb to ∼140 kb. These plasmid-encoded toxins are often closely associated with mobile elements. A C. perfringens strain can carry up to three different toxin plasmids, with a single plasmid carrying up to three distinct toxin genes. Molecular Koch's postulate analyses have established the importance of several plasmid-encoded toxins when C. perfringens disease strains cause enteritis or enterotoxemias. Many toxin plasmids are closely related, suggesting a common evolutionary origin. In particular, most toxin plasmids and some antibiotic resistance plasmids of C. perfringens share an ∼35-kb region containing a Tn916-related conjugation locus named tcp (transfer of clostridial plasmids). This tcp locus can mediate highly efficient conjugative transfer of these toxin or resistance plasmids. For example, conjugative transfer of a toxin plasmid from an infecting strain to C. perfringens normal intestinal flora strains may help to amplify and prolong an infection. Therefore, the presence of toxin genes on conjugative plasmids, particularly in association with insertion sequences that may mobilize these toxin genes, likely provides C. perfringens with considerable virulence plasticity and adaptability when it causes diseases originating in the gastrointestinal tract. PMID:23699255

  7. Plasmid-Chromosome Recombination of Irradiated Shuttle Vector DNA in African Green Monkey Kidney Cells.

    Mudgett, John Stuart

    1987-09-01

    An autonomously replicating shuttle vector was used to investigate the enhancement of plasmid-chromosome recombination in mammalian host cells by ultraviolet light and gamma radiation. Sequences homologous to the shuttle vector were stably inserted into the genome of African Green Monkey kidney cells to act as the target substrate for these recombination events. The SV40- and pBR322-derived plasmid DNA was irradiated with various doses of radiation before transfection into the transformed mammalian host cells. The successful homologous transfer of the bacterial ampicillin resistance (amp^{rm r}) gene from the inserted sequences to replace a mutant amp^->=ne on the shuttle vector was identified by plasmid extraction and transformation into E. coli host cells. Ultraviolet light (UV) was found not to induce homologous plasmid-chromosome recombination, while gamma radiation increased the frequency of recombinant plasmids detected. The introduction of specific double -strand breaks in the plasmid or prolonging the time of plasmid residence in the mammalian host cells also enhanced plasmid-chromosome recombination. In contrast, plasmid mutagenesis was found to be increased by plasmid UV irradiation, but not to change with time. Plasmid survival, recombination, and mutagenesis were not affected by treating the mammalian host cells with UV light prior to plasmid transfection. The amp^{rm r} recombinant plasmid molecules analyzed were found to be mostly the result of nonconservative exchanges which appeared to involve both homologous and possibly nonhomologous interactions with the host chromosome. The observation that these recombinant structures were obtained from all of the plasmid alterations investigated suggests a common mechanistic origin for plasmid -chromosome recombination in these mammalian cells.

  8. Mega electrorheological phenomena in graphene nanogels

    Dhar, Purbarun; Pattamatta, Arvind; Das, Sarit K

    2016-01-01

    Unprecedentedly massive electrorheology has been reported for dilute graphene nanoflakes based ER fluids that have been engineered as novel, readily synthesizable polymeric gels. Polyethylene glycol based graphene gels have been synthesized and very high ER response, 25,000 percent enhancement in viscosity under influence of electric field, has been observed for low concentration systems 2 wt. percent. The gels overcome several drawbacks innate to ER fluids. The gels exhibit long term stability, high graphene packing ratio which ensures very high ER response and the microstructure of the gels ensure that fibrillation of the graphene nanoflakes under field is undisturbed by thermal fluctuations, further leading to mega ER. The gels exhibit large yield stress handling caliber with yield stress observed as high as 13 kPa at 2 wt. perc. graphene. Detailed investigations on the effects of graphene concentration, electric field strength, imposed shear resistance and transients of electric field actuation on the ER ...

  9. Likelihood Analysis for Mega Pixel Maps

    Kogut, Alan J.

    1999-01-01

    The derivation of cosmological parameters from astrophysical data sets routinely involves operations counts which scale as O(N(exp 3) where N is the number of data points. Currently planned missions, including MAP and Planck, will generate sky maps with N(sub d) = 10(exp 6) or more pixels. Simple "brute force" analysis, applied to such mega-pixel data, would require years of computing even on the fastest computers. We describe an algorithm which allows estimation of the likelihood function in the direct pixel basis. The algorithm uses a conjugate gradient approach to evaluate X2 and a geometric approximation to evaluate the determinant. Monte Carlo simulations provide a correction to the determinant, yielding an unbiased estimate of the likelihood surface in an arbitrary region surrounding the likelihood peak. The algorithm requires O(N(sub d)(exp 3/2) operations and O(Nd) storage for each likelihood evaluation, and allows for significant parallel computation.

  10. Growth dependence of conjugation explains limited plasmid invasion in biofilms: an individual‐based modelling study

    Merkey, Brian; Lardon, Laurent; Seoane, Jose Miguel;

    2011-01-01

    Plasmid invasion in biofilms is often surprisingly limited in spite of the close contact of cells in a biofilm. We hypothesized that this poor plasmid spread into deeper biofilm layers is caused by a dependence of conjugation on the growth rate (relative to the maximum growth rate) of the donor....... By extending an individual‐based model of microbial growth and interactions to include the dynamics of plasmid carriage and transfer by individual cells, we were able to conduct in silico tests of this and other hypotheses on the dynamics of conjugal plasmid transfer in biofilms. For a generic model plasmid......, we find that invasion of a resident biofilm is indeed limited when plasmid transfer depends on growth, but not so in the absence of growth dependence. Using sensitivity analysis we also find that parameters related to timing (i.e. a lag before the transconjugant can transfer, transfer proficiency...

  11. Permanent resident

    Fisher, John F.

    2016-01-01

    The training of physicians in the past century was based primarily on responsibility and the chain-of-command. Those with the bulk of that responsibility in the fields of pediatrics and internal medicine were residents. Residents trained the medical students and supervised them carefully in caring for patients. Most attending physicians supervised their teams at arm's length, primarily serving as teachers of the finer points of diagnosis and treatment during set periods of the day or week wit...

  12. Persistence Mechanisms of Conjugative Plasmids

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    maintenance in the host cell. These importantly include the ability to self-mobilize in a process termed conjugative transfer, which may occur across species barriers. Other plasmid stabilizing mechanisms include the multimer resolution system, active partitioning, and post-segregational-killing of plasmid......Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the...... successful propagation and long-term continued existence of these extra-chromosomal elements is extensive. Apart from the accessory genetic elements that may provide plasmid-harboring cells a selective advantage, special focus is placed on the mechanisms conjugative plasmids employ to ensure their stable...

  13. Mega Construction Projects: using stakeholder management for enhanced sustainable construction

    Eyiah-Botwe, E; Aigbavboa, C; Thwala, WD

    2016-01-01

    The need for mega construction projects development for accelerated socio-economic growth is long overdue for developing countries. Some studies have considered stakeholder management and sustainable construction concepts separately without exploring the simultaneous use for mega projects delivery. This paper reviews the two concepts and suggests a process for enhanced sustainable construction delivery. This study forms part of a broader Ph.D. study on “Development of sustainable ...

  14. Permanent resident

    Fisher, John F.

    2016-01-01

    The training of physicians in the past century was based primarily on responsibility and the chain-of-command. Those with the bulk of that responsibility in the fields of pediatrics and internal medicine were residents. Residents trained the medical students and supervised them carefully in caring for patients. Most attending physicians supervised their teams at arm's length, primarily serving as teachers of the finer points of diagnosis and treatment during set periods of the day or week with a perfunctory signature on write-ups or progress notes. Residents endeavored to protect the attending physician from being heavily involved unless they were unsure about a clinical problem. Before contacting the attending physician, a more senior resident would be called. Responsibility was the ultimate teacher. The introduction of diagnosis-related groups by the federal government dramatically changed the health care delivery system, placing greater emphasis on attending physician visibility in the medical record, ultimately resulting in more attending physician involvement in day-to-day care of patients in academic institutions. Without specified content in attending notes, hospital revenues would decline. Although always in charge technically, attending physicians increasingly have assumed the role once dominated by the resident. Using biographical experiences of more than 40 years, the author acknowledges and praises the educational role of responsibility in his own training and laments its declining role in today's students and house staff. PMID:27193992

  15. In Silico Detection and Typing of Plasmids using PlasmidFinder and Plasmid Multilocus Sequence Typing

    Carattoli, Alessandra; Zankari, Ea; García-Fernández, Aurora; Larsen, Mette Voldby; Lund, Ole; Villa, Laura; Aarestrup, Frank Møller; Hasman, Henrik

    2014-01-01

    genomes of multidrug-resistant Enterobacteriaceae species by the rapid detection of known plasmid types. Replicon sequences from 559 fully sequenced plasmids associated with the family Enterobacteriaceae in the NCBI nucleotide database were collected to build a consensus database for integration into a...... plasmid sequence types (STs) and new alleles and ST variants. In conclusion, testing of the two Web tools using both fully assembled plasmid sequences and WGS-generated draft genomes showed them to be able to detect a broad variety of plasmids that are often associated with antimicrobial resistance in......In the work presented here, we designed and developed two easy-to-use Web tools for in silico detection and characterization of whole-genome sequence (WGS) and whole-plasmid sequence data from members of the family Enterobacteriaceae. These tools will facilitate bacterial typing based on draft...

  16. Mutations in a Partitioning Protein and Altered Chromatin Structure at the Partitioning Locus Prevent Cohesin Recruitment by the Saccharomyces cerevisiae Plasmid and Cause Plasmid Missegregation

    Yang, Xian-Mei; Mehta, Shwetal; Uzri, Dina; Jayaram, Makkuni; Velmurugan, Soundarapandian

    2004-01-01

    The 2μm circle is a highly persistent “selfish” DNA element resident in the Saccharomyces cerevisiae nucleus whose stability approaches that of the chromosomes. The plasmid partitioning system, consisting of two plasmid-encoded proteins, Rep1p and Rep2p, and a cis-acting locus, STB, apparently feeds into the chromosome segregation pathway. The Rep proteins assist the recruitment of the yeast cohesin complex to STB during the S phase, presumably to apportion the replicated plasmid molecules eq...

  17. Conjugative plasmids of Neisseria gonorrhoeae.

    Emilia Pachulec

    Full Text Available Many clinical isolates of the human pathogen Neisseria gonorrhoeae contain conjugative plasmids. The host range of these plasmids is limited to Neisseria species, but presence of a tetracycline (tetM determinant inserted in several of these plasmids is an important cause of the rapid spread of tetracycline resistance. Previously plasmids with different backbones (Dutch and American type backbones and with and without different tetM determinants (Dutch and American type tetM determinants have been identified. Within the isolates tested, all plasmids with American or Dutch type tetM determinants contained a Dutch type plasmid backbone. This demonstrated that tetM determinants should not be used to differentiate between conjugal plasmid backbones. The nucleotide sequences of conjugative plasmids with Dutch type plasmid backbones either not containing the tetM determinant (pEP5233 or containing Dutch (pEP5289 or American (pEP5050 type tetM determinants were determined. Analysis of the backbone sequences showed that they belong to a novel IncP1 subfamily divergent from the IncP1alpha, beta, gamma, delta and epsilon subfamilies. The tetM determinants were inserted in a genetic load region found in all these plasmids. Insertion was accompanied by the insertion of a gene with an unknown function, and rearrangement of a toxin/antitoxin gene cluster. The genetic load region contains two toxin/antitoxins of the Zeta/Epsilon toxin/antitoxin family previously only found in Gram positive organisms and the virulence associated protein D of the VapD/VapX toxin/antitoxin family. Remarkably, presence of VapX of pJD1, a small cryptic neisserial plasmid, in the acceptor strain strongly increased the conjugation efficiency, suggesting that it functions as an antitoxin for the conjugative plasmid. The presence of the toxin and antitoxin on different plasmids might explain why the host range of this IncP1 plasmid is limited to Neisseria species. The isolated plasmids

  18. A plasmid in the archaebacterium Sulfolobus acidocaldarius

    Yeats, Siobhán; McWilliam, Peter; Zillig, Wolfram

    1982-01-01

    A plasmid of mol. wt. ∼9 × 106 has been isolated from the archaebacterium Sulfolobus acidocaldarius strain B12. Plasmid production is induced by u.v. radiation. A copy of the plasmid is probably carried by the chromosome, integrated at a specific site. The entire plasmid, and also restriction fragments of it, has been cloned into Escherichia coli plasmid vectors, and the cleavage sites on the plasmid DNA of three restriction endonucleases have been mapped.

  19. Plasmid acquisition in microgravity

    Juergensmeyer, Margaret A.; Juergensmeyer, Elizabeth A.; Guikema, James A.

    1995-01-01

    In microgravity, bacteria often show an increased resistance to antibiotics. Bacteria can develop resistance to an antibiotic after transformation, the acquisition of DNA, usually in the form of a plasmid containing a gene for resistance to one or more antibiotics. In order to study the capacity of bacteria to become resistant to antibiotics in microgravity, we have modified the standard protocol for transformation of Escherichia coli for use in the NASA-flight-certified hardware package, The Fluid Processing Apparatus (FPA). Here we report on the ability of E. coli to remain competent for long periods of time at temperatures that are readily available on the Space Shuttle, and present some preliminary flight results.

  20. Evolved plasmid-host interactions reduce plasmid interference cost.

    Yano, Hirokazu; Wegrzyn, Katarznya; Loftie-Eaton, Wesley; Johnson, Jenny; Deckert, Gail E; Rogers, Linda M; Konieczny, Igor; Top, Eva M

    2016-09-01

    Antibiotic selection drives adaptation of antibiotic resistance plasmids to new bacterial hosts, but the molecular mechanisms are still poorly understood. We previously showed that a broad-host-range plasmid was poorly maintained in Shewanella oneidensis, but rapidly adapted through mutations in the replication initiation gene trfA1. Here we examined if these mutations reduced the fitness cost of TrfA1, and whether this was due to changes in interaction with the host's DNA helicase DnaB. The strains expressing evolved TrfA1 variants showed a higher growth rate than those expressing ancestral TrfA1. The evolved TrfA1 variants showed a lower affinity to the helicase than ancestral TrfA1 and were no longer able to activate the helicase at the oriV without host DnaA. Moreover, persistence of the ancestral plasmid was increased upon overexpression of DnaB. Finally, the evolved TrfA1 variants generated higher plasmid copy numbers than ancestral TrfA1. The findings suggest that ancestral plasmid instability can at least partly be explained by titration of DnaB by TrfA1. Thus under antibiotic selection resistance plasmids can adapt to a novel bacterial host through partial loss of function mutations that simultaneously increase plasmid copy number and decrease unfavorably high affinity to one of the hosts' essential proteins. PMID:27121483

  1. Measuring Polycentricity of Mega-City Regions in China Based on the Intercity Migration Flows

    Mu, Xiaoyan; Yeh, Anthony G. O.

    2016-06-01

    This paper uses the intercity migration flows to examine relations between Chinese cities, identify the important mega-city regions and measure each region's polycentricity from an interaction perspective. Data set contains the long-term residential migration trajectories of three million Sina weibo users across 345 cities. Cities with close connectivity deployed around one or several mega cities are identified as mega-city regions. Features of the mega-city regions are characterized by the strength of migration flows, density of connections, and regional migration patterns. The results show that the disparities exist in different mega-city regions; most mega-city regions are lack of polycentricity.

  2. Defining a quantitative framework for evaluation and optimisation of the environmental impacts of mega-event projects.

    Parkes, Olga; Lettieri, Paola; Bogle, I David L

    2016-02-01

    This paper presents a novel quantitative methodology for the evaluation and optimisation of the environmental impacts of the whole life cycle of a mega-event project: construction and staging the event and post-event site redevelopment and operation. Within the proposed framework, a mathematical model has been developed that takes into account greenhouse gas (GHG) emissions resulting from use of transportation fuel, energy, water and construction materials used at all stages of the mega-event project. The model is applied to a case study - the London Olympic Park. Three potential post-event site design scenarios of the Park have been developed: Business as Usual (BAU), Commercial World (CW) and High Rise High Density (HRHD). A quantitative summary of results demonstrates that the highest GHG emissions associated with the actual event are almost negligible compared to those associated with the legacy phase. The highest share of emissions in the legacy phase is attributed to embodied emissions from construction materials (almost 50% for the BAU and HRHD scenarios) and emissions resulting from the transportation of residents, visitors and employees to/from the site (almost 60% for the CW scenario). The BAU scenario is the one with the lowest GHG emissions compared to the other scenarios. The results also demonstrate how post-event site design scenarios can be optimised to minimise the GHG emissions. The overall outcomes illustrate how the proposed framework can be used to support decision making process for mega-event projects planning. PMID:26686076

  3. The Mega-Terrorism - The Challenge of the Third Millennium

    Daniel Andrișan

    2011-06-01

    Full Text Available The aim of this article is to describe the "new face" of terrorism in the twenty-first centuryindicating the transition to mass destruction weapons (nuclear terrorism, chemical, biological, toethnic-religious terrorism, the occurrence of massive gray area phenomena of terrorism and how thisphenomenon became a strategic weapon. Mega-terrorism has been existing, at a conceptual level,ever since the 70’s, when the experts of this phenomenon tried to find a semantic cover for thesituations that certain organizations, groups or terrorist or extremist sections would get someWeapons of Mass Destruction Systems. Actually, the 11th of September tragedy proves that megaterrorismrepresents the premeditated destruction, the lack of negotiations, of a tactical goal that wasto be accomplished by means of a threat. The mega-terrorism actors do not intend to get themselvesknown to the public, do not require anything, do not see the threat as means or device to reach theirpurpose. The 21 st century mega-terrorism simple logic is materialized in the systemic destroying ofthe enemy, no longer representing a political power or a government, but an entire ‘disobeying’,‘corrupted’, ‘unfaithful’ population indifferent to the mega-terrorist actors’ desires. New dimensionagainst mega-terrorism determines not only a rethinking of how to combat it, but also the realizationof a conceptual legal framework and measures established to materialize the political decision.

  4. Characterization of the particulate air pollution in contrasted mega cities

    This work aims at characterizing the physics and the chemistry that govern particulate air pollution in two mega cities (Paris and Cairo) for which the size distribution and the chemical composition of airborne particles were poorly documented. Seasonal variations of the main aerosol sources and transformation processes are investigated in these two urban centres, with a particular attention to semi-volatile material and secondary organic aerosols. Short-term health effects of Paris size-segregated aerosols, as well as particulate pollution during the Cairo 'Black Cloud' season, are also emphasized here. Finally, the comparison of results obtained for the two mega cities and for another one (Beijing) allows investigating main factors responsible for particulate air pollution in urban centres with contrasted climatic conditions and development levels. Notably, this work also allows the build-up of an experimental dataset which is now available for the modelling of urban air quality and of environmental impacts of mega city air pollution. (author)

  5. A new analysis of the MEGA M31 microlensing events

    Ingrosso, G; De Paolis, F; Jetzer, P; Nucita, A A; Scarpetta, G; Strafella, F; Jetzer, Ph.

    2006-01-01

    We discuss the results of the MEGA microlensing campaign towards M31. Our analysis is based on an analytical evaluation of the microlensing rate, taking into account the observational efficiency as given by the MEGA collaboration. In particular, we study the spatial and time duration distributions of the microlensing events for several mass distribution models of the M31 bulge. We find that only for extreme models of the M31 luminous components it is possible to reconcile the total observed MEGA events with the expected self-lensing contribution. Nevertheless, the expected spatial distribution of self-lensing events is more concentrated and hardly in agreement with the observed distribution. We find it thus difficult to explain all events as being due to self-lensing alone. On the other hand, the small number of events does not yet allow to draw firm conclusions on the halo dark matter fraction in form of MACHOs.

  6. Mega-masers, Dark Energy and the Hubble Constant

    Powerful water maser emission (water mega-masers) can be found in accretion disks in the nuclei of some galaxies. Besides providing a measure of the mass at the nucleus, such mega-masers can be used to determine the distance to the host galaxy, based on a kinematic model. We will explain the importance of determining the Hubble Constant to high accuracy for constraining the equation of state of Dark Energy and describe the Mega-maser Cosmology Project that has the goal of determining the Hubble Constant to better than 3%. Time permitting, we will also present the scientific capabilities of the current and future NRAO facilities: ALMA, EVLA, VLBA and GBT, for addressing key astrophysical problems

  7. Mega-masers, Dark Energy and the Hubble Constant

    Lo, Fred K. Y.

    2007-10-15

    Powerful water maser emission (water mega-masers) can be found in accretion disks in the nuclei of some galaxies. Besides providing a measure of the mass at the nucleus, such mega-masers can be used to determine the distance to the host galaxy, based on a kinematic model. We will explain the importance of determining the Hubble Constant to high accuracy for constraining the equation of state of Dark Energy and describe the Mega-maser Cosmology Project that has the goal of determining the Hubble Constant to better than 3%. Time permitting, we will also present the scientific capabilities of the current and future NRAO facilities: ALMA, EVLA, VLBA and GBT, for addressing key astrophysical problems

  8. The Java-Sumatra Aerial Mega-Tramway

    Bolonkin, Alexander; Cathcart, Richard

    2007-01-01

    A mega-tramway based on the Indonesian islands of Sumatra and Java is proposed to span Sunda Strait. The Java-Sumatra Aerial Mega-Tramway (JSAMT) will be self-elevating and will regularly and cheaply launch passengers and cargoes via two conveyor belt-like facilities using standard winged shipping containers like those currently used by international trucking and ocean shipping industries that are volplaned across the Sunda Strait. The JSAMT will be a self-sustaining toll facility free of any...

  9. Global Analysis and Structural Performance of the Tubed Mega Frame

    ZHANG, Han

    2014-01-01

    The Tubed Mega Frame is a new structure concept for high-rise buildings which is developed by Tyréns. In order to study the structural performance as well as the efficiency of this new concept, a global analysis of the Tubed Mega Frame structure is performed using finite element analysis software ETABS. Besides, the lateral loads that should be applied on the structure according to different codes are also studied. From the design code study for wind loads and seismic design response spectrum...

  10. Plasmid-mediated transformation in Bacillus megaterium.

    Brown, B. J.; Carlton, B C

    1980-01-01

    A transformation system was developed for Bacillus megaterium by using antibiotic resistance plasmid deoxyribonucleic acid molecules derived from Staphylococcus aureus and Bacillus cereus. Lysozyme-generated protoplasts of B. megaterium allowed uptake of plasmid deoxyribonucleic acid in the presence of polyethylene glycol. Transformants expressed the antibiotic resistance determinants present on the plasmid deoxyribonucleic acid, and reisolated plasmid deoxyribonucleic acid yielded restrictio...

  11. Strategies simulation model for the gas business chain MEGAS

    MEGAS is a simulation model representing fundamental parameters of Corpoven's natural gas and NGL production, handling, processing, transportation and distribution systems in the Venezuelan mid-east, as well as its financial implications. Various strategies regarding development, prices, costs, new business opportunities, production scenarios, demand and energy policies can be evaluated through this model in order to determine, after analyzing the economics results, a set of strategies to follow in the mid and long term. MEGAS could be also used to make risk analysis studies, considering that probabilistic parameters and variables like gas quality, production, demand, plant shutdowns and others are to be represented by their distinctive function. It is possible to set up a probabilistic function for each economic indicator or operating variables with an appropriate experiment design. MEGAS is based on a dynamic simulation language, which facilitates both the real system components representation and the main variables statistical data accumulation. It also allows graphical representation of results and the simulation animation. Demand and price forecasts, new projects, costs and capabilities of the systems are some of the model input data. MEGAS should be considered as a tool that eases the strategic planning of the business, making it possible for the Corporation to foresee changes, both in the domestic and international market, to predict how these changes could affect its business affairs and to visualize different return scenarios

  12. The partitioning and copy number control systems of the selfish yeast plasmid: an optimized molecular design for stable persistence in host cells

    Yen-Ting-Liu,; Sau, Saumitra; Ma, Chien-Hui; Kachroo, Aashiq H.; Rowley, Paul A.; Chang, Keng-Ming; Fan, Hsiu-Fang; Jayaram, Makkuni

    2014-01-01

    The multi-copy 2 micron plasmid of Saccharomyces cerevisiae, a resident of the nucleus, is remarkable for its high chromosome-like stability. The plasmid does not appear to contribute to the fitness of the host, nor does it impose a significant metabolic burden on the host at its steady state copy number. The plasmid may be viewed as a highly optimized selfish DNA element whose genome design is devoted entirely towards efficient replication, equal segregation and copy number maintenance. A pa...

  13. Effects of genes exerting growth inhibition and plasmid stability on plasmid maintenance.

    Boe, L; Gerdes, K; Molin, S

    1987-01-01

    Plasmid stabilization mediated by the parA+ and parB+ genes of the R1 plasmid and the ccd+ and sop+ genes of the F plasmid was tested on a mini-R1 plasmid and a pBR322 plasmid derivative. The mini-R1 plasmid is thought to be unstably inherited owing to a low copy number and to random segregation of the plasmid at cell division, whereas cells harboring the pBR322 derivative used in this work are lost through competition with plasmid-free cells, mainly as a result of the shorter generation time...

  14. Repair in E. coli of transforming plasmid DNA damaged by psoralen plus near-ultraviolet irradiation

    Treatment of DNA with psoralen plus near-ultraviolet irradiation gives rise to both monoadducts and cross-links. The authors have examined the repair of plasmid NTP16 DNA treated in this way in vitro and then used to transform E. coli. Monoadducts are found to be potentially lethal, and can be repaired by uvr-dependent and recA-dependent pathways. The presence of a related resident plasmid in the transformed cells can enhance the survival of the incoming damaged NTP16 DNA. This effect is not recA-dependent. Removal of unbound psoralen from the plasmid DNA and exposure to further NUV is known to increase the ratio of cross-links to monoadducts, and the authors demonstrate that such cross-linked plasmid DNA is not readily repaired following transformation. However in the presence of homologous DNA there is evidence for the repair, and hence uptake by the cell, of cross-linked DNA. (Auth.)

  15. Management of infected custom mega prosthesis by Ilizarov method

    Karthik Gudaru

    2015-12-01

    Full Text Available A 26 year old male patient with an aggressive giant cell tumour of the left distal femur was managed by wide excision and insertion of custom mega prosthesis. Patient developed deep infection which did not subside with multiple debridements and antibiotics. Hence the custom mega prosthesis was removed and the bone gap was managed by Ilizarov method. Ilizarov fixation of the left femur and tibia was done. Femoral and tibial corticotomy was done and the bone segments were transported towards the knee to finally achieve a knee arthrodesis. The case illustrates the method and difficulties encountered during the treatment. [Int J Res Med Sci 2015; 3(12.000: 3874-3878

  16. Astrocyte mega-domain hypothesis of the autistic savantism.

    Mitterauer, Bernhard J

    2013-01-01

    Individuals with autism who show high abilities are called savants. Whereas in their brains a disconnection in and between neural networks has been identified, savantism is yet poorly understood. Focusing on astrocyte domain organization, it is hypothesized that local astrocyte mega-organizations may be responsible for exerting high capabilities in brains of autistic savants. Astrocytes, the dominant glial cell type, modulate synaptic information transmission. Each astrocyte is organized in non-overlapping domains. Formally, each astrocyte contacting n-neurons with m-synapses via its processes generates dynamic domains of synaptic interactions based on qualitative computation criteria, and hereby it structures neuronal information processing. If the number of processes is genetically significantly increased, these astrocytes operate in a mega-domain with a higher complexitiy of computation. From this model savant abilities are deduced. PMID:23098371

  17. Genomic and Functional Characterization of qnr-Encoding Plasmids from Municipal Wastewater Biosolid Klebsiella pneumoniae Isolates

    Kaplan, Ella; Sela, Noa; Doron-Faigenboim, Adi; Navon-Venezia, Shiri; Jurkevitch, Edouard; Cytryn, Eddie

    2015-01-01

    -like plasmids concomitant to phylogenetic analysis of housekeeping genes from host Klebsiella strains, revealed that these plasmids are limited to a predominantly human-associated sub-clade of Klebsiella, suggesting that their host range is very narrow. Conversely, the pGNB2-like plasmids had a much broader host range and appeared to be associated with Klebsiella residing in natural environments. This study suggests that: (A) qnrB-harboring multidrug-resistant pKPN3-like plasmids can endure the rigorous wastewater treatment process and may therefore be disseminated to downstream environments; and (B) that small qnrS-harboring pGNB2-like plasmids are ubiquitous in wastewater treatment facilities and are most likely environmental in origin. PMID:26696974

  18. Antiparallel plasmid-plasmid pairing may control P1 plasmid replication.

    Abeles, A L; Austin, S J

    1991-01-01

    The copy number of the P1 plasmid replicon is stringently controlled, giving only one or two copies per newborn cell. Control is achieved by the action of the copy-control locus incA, which contains nine repeats of the 19-basepair binding site for the plasmid-encoded initiator protein RepA. A set of five similar repeats are present in the replication origin where RepA acts to trigger initiation. Using an in vitro replication system consisting of an Escherichia coli extract, the P1 origin as a...

  19. Assessment of MEGA BORG impacts on sea turtles

    Studies were conducted to assess the impacts of the MEGA BORG oil spill on sea turtles in the path of the oil plume. Aerial surveys were performed to determine the presence of turtles and provide a gross visual assessment of potential impacts. Although extensive efforts were made to capture sea turtles around oil and gas platforms only one loggerhead sea turtle, Caretta caretta, was captured. Neither external visual inspection nor laboratory fecal analysis showed evidence of petroleum contamination

  20. ROLE OF MEGA SPORT EVENTS ON BRANDING DESTINATIONS

    Abolfazl Farahani; Habib Honari; Hasan Asadi; Abdul Hamid Zeitoonly; Mohammad Pour Ranjbar

    2011-01-01

    Sporting events to help make creating beautiful scenery and unique areas to tourism. Thepurpose of this study was investigated the role of holding sporting events on destinationsBranding with hosted of mega sports event (Traditional Sport ;hors riding) on branding sportstourism destinations in Golestan province. Data from a questionnaire (Cronbach's alpha = 91%)and interviews were collected. Statistical population of this study was 217 patients (53 expert(cultural heritage; physical education...

  1. Some Aspects of Mega-Floating Airport Design and Production

    Hadžić, Neven; Tomić, Marko; Vladimir, Nikola; Senjanović, Ivo

    2016-01-01

    Mega-Floating Airports (MFA) are unique and complex offshore transport system components that emerged as a consequence of tremendous land price increase in the vicinity of very large coastal cities. An overview of MFAs design and production aspects is presented within this paper including design concept, model tests and full scale measurement, air transport analysis, infrastructure, main particulars and structure, wave breaker, hydroelastic analysis due to wave load and airplane moving ...

  2. Mega borg oil spill: Fate and effect studies

    The Mega Borg, a Norwegian tanker, released an estimated 5.1 million gallons (gal) of Palanca Angola crude oil into the Gulf of Mexico during a lightering accident and subsequent fire. The collection of reports was designed to provide a comprehensive overview of the spill chronology, the fate of the oil released, and subsequent studies that were conducted to assess the impacts of the oil spill on the environment and its biota

  3. The Mega-Terrorism - The Challenge of the Third Millennium

    Daniel Andrișan

    2011-01-01

    The aim of this article is to describe the "new face" of terrorism in the twenty-first centuryindicating the transition to mass destruction weapons (nuclear terrorism, chemical, biological), toethnic-religious terrorism, the occurrence of massive gray area phenomena of terrorism and how thisphenomenon became a strategic weapon. Mega-terrorism has been existing, at a conceptual level,ever since the 70’s, when the experts of this phenomenon tried to find a semantic cover for thesituations that ...

  4. TICKET UNDERPRICING AND PUBLIC SUPPORT FOR MEGA-EVENTS

    Eichhorn, Christoph; Sahm, Marco

    2010-01-01

    The organizer of a mega-event often owns a monopoly for several products like tickets and sponsorship contracts. While ticket prices below the maximum sellout price reduce gate revenues, they increase the degree to which the event is accepted by the population of the host region. Since public support usually serves as an important input factor for sponsors, it increases revenues in the market for sponsorship contracts. Hence, ticket underpricing may well maximize overall profits of the organi...

  5. Plasmid profiling of bacterial isolates from confined environments

    van Houdt, Rob; Provoost, Ann; Coninx, Ilse; Leys, Natalie; Mergeay, Max

    Plasmid profiling of bacterial isolates from confined environments R. Van Houdt, I. Coninx, A. Provoost, N. Leys, and M. Mergeay Expertise group for Molecular and Cellular Biology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre (SCK•CEN), Boeretang 200, B-2400 Mol, Belgium. Human exploration of extreme and isolated hostile environments such as space requires special confined small volume habitats to protect and house the crew. However, human confinement in such small volume habitats has restrictions on waste disposal and personal hygiene and inevitably generates a particular community of microorganisms within the habitat. These microorganisms are mainly originating from the crew (skin, mucous membranes, upper respiratory tract, mouth, and gastrointestinal tract) but also include the residing environmental microorganisms. Earth-based confined habitats such as the Antarctic Research Station Concordia are used as test beds for long-duration spaceflights to study the physiologic and psychological adaptation to isolated environments. The dynamics of the environmental microbial population in such a test bed could render additional insights in assessing the potential health risks in long-duration space missions. Not only total bacterial contamination levels are important, but it is essential to identify also the predominant microbial taxa and their mobile genetic elements (MGE). These MGEs could be exchanged between bacteria by horizontal gene transfer and may alter the pathogenic potential since they often carry antibiotic resistance or more in general adaptation-enhancing traits. In this study several bacterial strains isolated in the Concordia research station were examined for their plasmid content. An optimized protocol for extraction of large plasmids showed the present of at least one plasmid in 50% of the strains. For all strains the minimal inhibitory concentration of a range of antibiotics was determined indicating resistance to

  6. A plasmid in Legionella pneumophila.

    Knudson, G B; Mikesell, P

    1980-01-01

    Sixteen strains from the six serogroups of Legionella pneumophila were examined for the presence of extrachromosomal genetic elements by a modified cleared lysate procedure, dye-buoyant centrifugation, and agarose gel electrophoresis. Two strains, Atlanta-1 and Atlanta-2 from serogroup II, each contained a plasmid of cryptic function with a molecular weight of ca. 30 megadaltons.

  7. Bacterial Plasmids in Antarctic Natural Microbial Assemblages

    Kobori, Hiromi; Sullivan, Cornelius W.; Shizuya, Hiroaki

    1984-01-01

    Samples of psychrophilic and psychrotrophic bacteria were collected from sea ice, seawater, sediments, and benthic or ice-associated animals in McMurdo Sound, Antarctica. A total of 155 strains were isolated and tested for the presence of plasmids by DNA agarose gel electrophoresis. Thirty-one percent of the isolates carried at least one kind of plasmid. Bacterial isolates taken from sediments showed the highest plasmid incidence (42%), and isolates from seawater showed the lowest plasmid inc...

  8. Plasmid maintenance functions encoded on Dictyostelium discoideum nuclear plasmid Ddp1.

    Hughes, J E; H. Kiyosawa; Welker, D L

    1994-01-01

    All of the plasmid-carried genes expressed during vegetative growth are essential for long-term maintenance of plasmid Ddp1 in the nucleus of Dictyostelium discoideum. Deletion of Ddp1 genes expressed only during development had no detectable effect on plasmid maintenance. Deletion of vegetatively expressed genes, either singly or in pairs, resulted in (i) a rapid loss of plasmid from cells grown in the absence of selection for plasmid retention, (ii) variation in the proportion of monomer to...

  9. IncP-1β Plasmid pGNB1 Isolated from a Bacterial Community from a Wastewater Treatment Plant Mediates Decolorization of Triphenylmethane Dyes▿

    Schlüter, Andreas; Krahn, Irene; Kollin, Florian; Bönemann, Gabriele; Stiens, Michael; Szczepanowski, Rafael; Schneiker, Susanne; Pühler, Alfred

    2007-01-01

    Plasmid pGNB1 was isolated from bacteria residing in the activated sludge compartment of a wastewater treatment plant by using a transformation-based approach. This 60-kb plasmid confers resistance to the triphenylmethane dye crystal violet and enables its host bacterium to decolorize crystal violet. Partial sequencing of pGNB1 revealed that its backbone is very similar to that of previously sequenced IncP-1β plasmids. The two accessory regions of the plasmid, one located downstream of the re...

  10. Characterization of plasmids in Erwinia stewartii.

    Coplin, D. L.; Rowan, R G; Chisholm, D A; Whitmoyer, R E

    1981-01-01

    Plasmids in 39 strains of Erwinia stewartii were examined by agarose gel electrophoresis. Most virulent strains had from 11 to 13 plasmids ranging in molecular mass from 2.8 to 210 megadaltons and contained plasmids of 210, 70, 49, 43, 29.5, 16.8, 8.8, and 2.8 megadaltons. Plasmids in strains SW2 and SS104 were characterized by both electron microscopy and agarose gel electrophoresis and may be useful as convenient references for sizing plasmids by electrophoresis. Specific size classes of pl...

  11. Residency Allocation Database

    Department of Veterans Affairs — The Residency Allocation Database is used to determine allocation of funds for residency programs offered by Veterans Affairs Medical Centers (VAMCs). Information...

  12. Social and philosophical conceptualization mega society as the body in the context of global synergetic methodology

    Мельник, Вікторія Володимирівна

    2014-01-01

    This paper analyzes how global body; theoretical and conceptual framework of the society as a single mega social, cultural and global organism; concepts and categories of the mega social context in synergetic methodology as attractors, repeler " cultural circle" , the development of culture in the context mega society; Cultural Dialogue in the global development community. It is proved that cultural interaction seems important structure- factor that binds the human community and discovers ide...

  13. Mechanism Analysis and Parameter Optimization of Mega-Sub-Isolation System

    Xiangxiu Li; Ping Tan; Xiaojun Li; Aiwen Liu

    2016-01-01

    The equation of motion of mega-sub-isolation system is established. The working mechanism of the mega-sub-isolation system is obtained by systematically investigating its dynamic characteristics corresponding to various structural parameters. Considering the number and location of the isolated substructures, a procedure to optimally design the isolator parameters of the mega-sub-isolation system is put forward based on the genetic algorithm with base shear as the optimization objective. The i...

  14. How to make mega-cities energy efficient?

    Aoki, Hitoshi; Aoki, Yoshitaka

    2010-09-15

    Tokyo is a Megalopolis with 40 million+ population. It has an energy efficient profile due to its uniqueness as extensive mass rail transit networks, high density and compact urban formation, compact space oriented life style. The other feature is extensive use of electric heat pumps (EHP), which entails low carbon city profile. Further possibility is prepared with water thermal energy utilization, which is widely available also through EHP particularly in Tokyo central districts, which could make Tokyo one of the lowest carbon cities in the world. Emerging mega-cities are expected to learn from Tokyo's success and not from western conventional models.

  15. Virulence Plasmids of Spore-Forming Bacteria.

    Adams, Vicki; Li, Jihong; Wisniewski, Jessica A; Uzal, Francisco A; Moore, Robert J; McClane, Bruce A; Rood, Julian I

    2014-12-01

    Plasmid-encoded virulence factors are important in the pathogenesis of diseases caused by spore-forming bacteria. Unlike many other bacteria, the most common virulence factors encoded by plasmids in Clostridium and Bacillus species are protein toxins. Clostridium perfringens causes several histotoxic and enterotoxin diseases in both humans and animals and produces a broad range of toxins, including many pore-forming toxins such as C. perfringens enterotoxin, epsilon-toxin, beta-toxin, and NetB. Genetic studies have led to the determination of the role of these toxins in disease pathogenesis. The genes for these toxins are generally carried on large conjugative plasmids that have common core replication, maintenance, and conjugation regions. There is considerable functional information available about the unique tcp conjugation locus carried by these plasmids, but less is known about plasmid maintenance. The latter is intriguing because many C. perfringens isolates stably maintain up to four different, but closely related, toxin plasmids. Toxin genes may also be plasmid-encoded in the neurotoxic clostridia. The tetanus toxin gene is located on a plasmid in Clostridium tetani, but the botulinum toxin genes may be chromosomal, plasmid-determined, or located on bacteriophages in Clostridium botulinum. In Bacillus anthracis it is well established that virulence is plasmid determined, with anthrax toxin genes located on pXO1 and capsule genes on a separate plasmid, pXO2. Orthologs of these plasmids are also found in other members of the Bacillus cereus group such as B. cereus and Bacillus thuringiensis. In B. thuringiensis these plasmids may carry genes encoding one or more insecticidal toxins. PMID:26104459

  16. Novel archaeal plasmid pAH1 and its interactions with the lipothrixvirus AFV1

    Basta, Tamara; Smyth, John; Forterre, Patrick; Prangishvili, David; Peng, Xu

    2009-01-01

    At present very little is known about interactions between extrachromosomal genetic elements in Archaea. Here we describe an Acidianus strain which carries naturally a novel 28 kb conjugative plasmid-like element, pAH1, and also serves as a laboratory host for lipothrixvirus AFV1. In an attempt t...... observed in bacteria where relevant bacteriophages either are dependent on a conjugative plasmid for successful infection or are excluded by a resident plasmid.......At present very little is known about interactions between extrachromosomal genetic elements in Archaea. Here we describe an Acidianus strain which carries naturally a novel 28 kb conjugative plasmid-like element, pAH1, and also serves as a laboratory host for lipothrixvirus AFV1. In an attempt to...... establish a system for studying plasmid-virus interactions we characterized the genome of pAH1 which closely resembles those of the Sulfolobus conjugative plasmids pARN3 and pARN4. pAH1 integrates site specifically into, and excises from, the host chromosome indicating a dynamic interaction with the latter...

  17. ColE1-plasmid production in Escherichia coli: Mathematical Simulation and Experimental Validation

    Inga eFreudenau

    2015-09-01

    Full Text Available Plasmids have become very important as pharmaceutical gene vectors in the fields of gene therapy and genetic vaccination in the last years. In this study, we present a dynamic model to simulate the ColE1-like plasmid replication control, once for a DH5α-strain carrying a low copy plasmid (DH5α-pSUP 201-3 and once for a DH5α-strain carrying a high copy plasmid (DH5α-pCMV-lacZ by using ordinary differential equations (ODE and the MATLAB software. The model includes the plasmid replication control by two regulatory RNA molecules (RNAI and RNAII as well as the replication control by uncharged tRNA molecules. To validate the model, experimental data like RNAI- and RNAII concentration, plasmid copy number (PCN, and growth rate for three different time points in the exponential phase were determined. Depending on the sampled time point, the measured RNAI and RNAII concentrations for DH5α-pSUP 201-3 reside between 6 ±0.7 to 34 ±7 RNAI molecules per cell and 0.44 ±0.1 to 3 ±0.9 RNAII molecules per cell. The determined plasmid copy numbers (PCN averaged between 46 ±26 to 48 ±30 plasmids per cell. The experimentally determined data for DH5α-pCMV-lacZ reside between 345 ±203 to 1086 ±298 RNAI molecules per cell and 22 ±2 to 75 ±10 RNAII molecules per cell with an averaged PCN of 1514 ±1301 to 5806 ±4828 depending on the measured time point. As the model was shown to be consistent with the experimentally determined data, measured at three different time points within the growth of the same strain, we performed predictive simulations concerning the effect of uncharged tRNA molecules on the ColE1-like plasmid replication control. The hypothesis is that these tRNA molecules would have an enhancing effect on the plasmid production. The in silico analysis predicts that uncharged tRNA molecules would indeed increase the pDNA production.

  18. Homemade Site Directed Mutagenesis of Whole Plasmids

    Laible, Mark; Boonrod, Kajohn

    2009-01-01

    Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. With this method the cloned target gene can be altered by substitution, deletion or insertion of a few bases directly into a plasmid. It works by simply amplifying the whole plasmid, in a non PCR-based thermocycling reaction. During the reaction mutagenic primers, carrying the desired mutation, are integrated into the newly synthesized plasmid. In this video tutorial we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid. The protocol works with standard reagents and is independent from commercial kits, which often are very expensive. Applying this protocol can reduce the total cost of a reaction to an eighth of what it costs using some of the commercial kits. In this video we also comment on critical steps during the process and give detailed instructions on how to design the mutagenic primers. PMID:19488024

  19. Plasmid and chromosome partitioning: surprises from phylogeny

    Gerdes, Kenn; Møller-Jensen, Jakob; Bugge Jensen, Rasmus

    2000-01-01

    Plasmids encode partitioning genes (par) that are required for faithful plasmid segregation at cell division. Initially, par loci were identified on plasmids, but more recently they were also found on bacterial chromosomes. We present here a phylogenetic analysis of par loci from plasmids...... and chromosomes from prokaryotic organisms. All known plasmid-encoded par loci specify three components: a cis-acting centromere-like site and two trans-acting proteins that form a nucleoprotein complex at the centromere (i.e. the partition complex). The proteins are encoded by two genes in an operon...... that is autoregulated by the par-encoded proteins. In all cases, the upstream gene encodes an ATPase that is essential for partitioning. Recent cytological analyses indicate that the ATPases function as adaptors between a host-encoded component and the partition complex and thereby tether plasmids and chromosomal...

  20. Local meanings of a sport mega-event's legacies : Stories from a South African urban neighbourhood

    Waardenburg, Maikel; van den Bergh, Marjolein; van Eekeren, Frank

    2015-01-01

    Studies on sport mega-events and their legacies often seem only loosely connected to local experiences. Stories on sport mega-event legacy appear as a setting-the-scene or function as a reference to illustrate specific types of legacy. However, stories themselves are never the primary focus in these

  1. Development of sewage system for mega-city Karachi

    The growth of mega-cities in recent times has brought to the fore a large number of issues with respect environmental conditions such as development of slum areas, poor localities, solid waste disposal, management of sewage system, lack of open spaces and health facilities. One of the major issues effecting environment proper disposal of sewage and development of sewage system including recycling of sewage water and its use. The heavy pressure of population calls for adequate provision of sewage disposal in the new areas and remodeling of systems in the old areas of the cities to ensure a pollution-free environment. Recycling of sewage and prevention of sewage discharge into natural water channels and the sea has to be undertaken on urgent bases. The paper seeks to outline the present status of sewage system of the city of Karachi, the problems involved and the proposals for management and development of the system compatible with the need and requirement of mega-city population. (author)

  2. MegaPipe astrometry for the New Horizons spacecraft

    Gwyn, Stephen D J

    2014-01-01

    The New Horizons spacecraft, launched by NASA in 2006, will arrive in the Pluto-Charon system on July 14, 2015. There, it will spend a few hours imaging Pluto and its moons. It will then have a small amount of reserve propellant which will be used to direct the probe on to a second, yet to be discovered object in the Kuiper Belt. Data from the MegaPrime camera on CFHT was used to build a precise, high density astrometric reference frame for both the final approach into the Pluto system and the search for the secondary target. Pluto currently lies in the galactic plane. This is a hindrance in that there are potential problems with confusion. However, it is also a benefit, since it allows the use of the UCAC4 astrometric reference catalog, which is normally too sparse for use with MegaCam images. The astrometric accuracy of the final catalogs, as measured by the residuals, is 0.02 arcseconds.

  3. Mega Construction Projects: using stakeholder management for enhanced sustainable construction

    Eyiah-Botwe, E

    2016-06-01

    Full Text Available The need for mega construction projects development for accelerated socio-economic growth is long overdue for developing countries. Some studies have considered stakeholder management and sustainable construction concepts separately without exploring the simultaneous use for mega projects delivery. This paper reviews the two concepts and suggests a process for enhanced sustainable construction delivery. This study forms part of a broader Ph.D. study on “Development of sustainable stakeholder management framework for construction projects” aimed at improving stakeholder management process and project delivery. A qualitative research method approach was adopted. An extensive literature review on stakeholder management and sustainable construction was conducted using filtering method for four major journals from the institution database. Identified concepts were developed into a conceptual framework and validated using face to face semi-structured interviews involving ten key stakeholders. The findings are that stakeholder management and sustainability concepts are yet to embrace. This paper suggests a seven-step approach for project managers. (1 Embracing stakeholder management and sustainability concepts, (2 identify stakeholder approach and sustainable principle to adopt, (3 identify and classify project stakeholders, (4 engage stakeholders, (5 analyze stakeholders, (6 manage stakeholders and sustainable principle, (7 monitor and support process.

  4. Uptake of plasmid deoxyribonucleic acid by Haemophilus.

    Gromkova, R; Goodgal, S

    1981-01-01

    The uptake of circular and linear plasmid RSF0885 deoxyribonucleic acids, (DNAs) obtained from Haemophilus parainfluenzae 14, in both homologous and heterologous recipients was studied and compared with that of chromosomal DNA. High concentrations of divalent cations stimulated the uptake of either circular or linear plasmid DNA in H. parainfluenzae 14 competent cells but did not affect the uptake of chromosomal DNA. The biological activity of linear plasmid DNA was similar to that of circula...

  5. [Pregnancy during residency].

    Maas, S M; van 't Hoff, B W; Rings, E H; van der Waals, F W; Büller, H A

    1992-12-19

    The number of female residents in the Netherlands has steadily increased in recent years. Due to the increased time on waiting lists to enter residency programmes and to the increased duration of training, female residents will be older during their residencies. This will probably result in an increased number of pregnancies during residencies. A questionnaire regarding pregnancy during residency was sent to 191 residents in two university hospitals in the Netherlands. The response rate was 74.3%. Fifty percent of the male and only 19% of the female residents had children. No negative effects of a pregnancy on their training were experienced or anticipated by the residents. However, a negative effect on the functioning of the department was expected. No formal provisions, like replacements were available and many solutions to replace pregnant colleagues depended on the flexibility of the colleagues. The wish to have children was high and equally distributed among male and female residents, 92% and 96%, resp. Given the difficulty to seek a permanent position and to have children after residency, the choice of many female residents will be to have their children during residency. This increase in number of pregnancies requires anticipation of the residency programme directors. They should take the lead in proposing adequate regulations. PMID:1470257

  6. pLS010 plasmid vector

    Lacks, Sanford A.; Balganesh, Tanjore S.

    1988-01-01

    Disclosed is recombinant plasmid pLS101, consisting essentially of a 2.0 Kb malM gene fragment ligated to a 4.4 Kb T.sub.c r DNA fragment, which is particularly useful for transforming Gram-positive bacteria. This plasmid contains at least four restriction sites suitable for inserting exogeneous gene sequences. Also disclosed is a method for plasmid isolation by penicillin selection, as well as processes for enrichment of recombinant plasmids in Gram-positive bacterial systems.

  7. Chromate resistance plasmid in Pseudomonas fluorescens.

    Bopp, L H; Chakrabarty, A M; Ehrlich, H. L.

    1983-01-01

    Chromate resistance of Pseudomonas fluorescens LB300, isolated from chromium-contaminated sediment in the upper Hudson River, was found to be plasmid specified. Loss of the plasmid (pLHB1) by spontaneous segregation or mitomycin C curing resulted in a simultaneous loss of chromate resistance. Subsequent transformation of such strains with purified pLHB1 plasmid DNA resulted in a simultaneous re-acquisition of the chromate resistance phenotype and the plasmid. When pLHB1 was transferred by con...

  8. MEGA7: Molecular Evolutionary Genetics Analysis Version 7.0 for Bigger Datasets.

    Kumar, Sudhir; Stecher, Glen; Tamura, Koichiro

    2016-07-01

    We present the latest version of the Molecular Evolutionary Genetics Analysis (Mega) software, which contains many sophisticated methods and tools for phylogenomics and phylomedicine. In this major upgrade, Mega has been optimized for use on 64-bit computing systems for analyzing larger datasets. Researchers can now explore and analyze tens of thousands of sequences in Mega The new version also provides an advanced wizard for building timetrees and includes a new functionality to automatically predict gene duplication events in gene family trees. The 64-bit Mega is made available in two interfaces: graphical and command line. The graphical user interface (GUI) is a native Microsoft Windows application that can also be used on Mac OS X. The command line Mega is available as native applications for Windows, Linux, and Mac OS X. They are intended for use in high-throughput and scripted analysis. Both versions are available from www.megasoftware.net free of charge. PMID:27004904

  9. ANALYSIS OF A MODEL OF PLASMID-BEARING, PLASMID-FREE COMPETITION IN A PULSED CHEMOSTAT

    XIANGYUN SHI; XINYU SONG; XUEYONG ZHOU

    2006-01-01

    We introduce and study a chemostat model with plasmid-bearing, plasmid-free competition and impulsive effect. According to the stability analysis of the boundary periodic solution, we obtain the invasion threshold of the plasmid-free organism and plasmid-bearing organism. Furthermore, by using standard techniques of bifurcation theory, we prove the system has a positive τ-periodic solution, which shows that the impulsive effect destroys the equilibria of the unforced continuous system and ini...

  10. Plasmid ColVBtrp maintenance in Erwinia carotovora.

    Schukin, N N

    1981-01-01

    Plasmid ColVBtrp maintenance in Erwinia carotovora cells was followed by measuring kinetics of elimination of plasmid genetic markers and loss of plasmid deoxyribonucleic acid. An E. carotovora mutant stably carrying plasmid ColVBtrp was isolated. Besides stable plasmid maintenance, the mutant showed altered sensitivity to male-specific phage MS2, sensitivity to drugs, and colony morphology.

  11. The expression of a plasmid-specified exported protein causes structural plasmid instability in Bacillus subtilis

    Cordes, C.; Meima, R; Twiest, B; Kazemier, B; Venema, G; vanDijl, JM; Bron, S

    1996-01-01

    The rolling-circle plasmid pGP1 was used to study the effects of the expression of a plasmid-specified exported protein on structural plasmid stability in Bacillus subtilis. pGP1 contains a fusion between the Bacillus licheniformis penP gene, encoding a C-terminally truncated penicillinase, and the

  12. Resident Characteristics Report

    Department of Housing and Urban Development — The Resident Characteristics Report summarizes general information about households who reside in Public Housing, or who receive Section 8 assistance. The report...

  13. Isolation of Plasmid DNA from Butyrivibrio fibrisolvens†

    Teather, Ronald M.

    1982-01-01

    A procedure based on successive precipitation of cell lysates with sodium dodecyl sulfate-NaCl and polyethylene glycol 6000 was developed which allows the isolation of plasmid DNA from Butyrivibrio fibrisolvens. A survey of B. fibrisolvens strains isolated from the bovine rumen showed that plasmids are a common feature of this species.

  14. Plasmid deoxyribonucleic acid replication in Streptomyces griseus.

    Xue, Y.; Zhuang, Z.; Zhu, Y.; Xu, Y.; Dong, K.

    1981-01-01

    A series of electron micrographs showing the presence of different molecular forms representing various replication stages of plasmid deoxyribonucleic acid from Streptomyces griseus was obtained. Based upon an analysis of these electron micrographs, a tentative model for plasmid deoxyribonucleic acid replication in S. griseus is proposed.

  15. Plasmid-mediated horizontal gene transfer is a coevolutionary process

    Harrison, Ellie; Brockhurst, Michael A

    2012-01-01

    Conjugative plasmids are key agents of horizontal gene transfer (HGT) that accelerate bacterial adaptation by vectoring ecologically important traits between strains and species. However, although many conjugative plasmids carry beneficial traits, all plasmids exert physiological costs-of-carriage on bacteria. The existence of conjugative plasmids, therefore, presents a paradox because non-beneficial plasmids should be lost to purifying selection, whereas beneficial genes carried on plasmids ...

  16. Conservation of plasmid DNA sequences in coronatine-producing pathovars of Pseudomonas syringae

    Bender, C.L.; Young, S.A. (Oklahoma State Univ., Stillwater (United States)); Mitchell, R.E. (Dept. of Scientific and Industrial Research, Auckland (New Zealand))

    1991-04-01

    In Pseudomonas syringae pv. tomato PT23.2, plasmid pPT23A (101 kb) is involved in synthesis of the phytotoxin coronatine. The physical characterization of mutations that abolished coronatine production indicated that at least 30 kb of pPT23A DNA are required for toxin synthesis. In the present study, {sup 32}P-labeled DNA fragments from the 30-kb region of pPT23A hybridized to plasmid DNAs from several coronatine-producing pathovars of P. syringae under conditions of high stringency. These experiments indicated that this region of pPT23A was strongly conserved in large plasmids (90 to 105 kb) that reside in P. syringae pv. atropurpurea, glycinea, and morsprunorum. The functional significance of the observed homology was demonstrated in marker-exchange experiments in which Tn5-inactivated sequences from the 30-kb region of pPT23A were used to mutate coronatine synthesis genes in the three heterologous pathovars. Physical characterization of the Tn5 insertions generated by marker exchange indicated that genes controlling coronatine synthesis in P. syringae pv. atropurpurea 1304, glycinea 4180, and morsprunorum 567 and 3714 were located on the large indigenous plasmids where homology was originally detected. Therefore, coronatine biosynthesis genes are strongly conserved in the plasmid DNAs of four producing pathovars, despite their disparate origins (California, Japan, New Zealand, Great Britain, and Italy).

  17. Conservation of plasmid DNA sequences in coronatine-producing pathovars of Pseudomonas syringae

    In Pseudomonas syringae pv. tomato PT23.2, plasmid pPT23A (101 kb) is involved in synthesis of the phytotoxin coronatine. The physical characterization of mutations that abolished coronatine production indicated that at least 30 kb of pPT23A DNA are required for toxin synthesis. In the present study, 32P-labeled DNA fragments from the 30-kb region of pPT23A hybridized to plasmid DNAs from several coronatine-producing pathovars of P. syringae under conditions of high stringency. These experiments indicated that this region of pPT23A was strongly conserved in large plasmids (90 to 105 kb) that reside in P. syringae pv. atropurpurea, glycinea, and morsprunorum. The functional significance of the observed homology was demonstrated in marker-exchange experiments in which Tn5-inactivated sequences from the 30-kb region of pPT23A were used to mutate coronatine synthesis genes in the three heterologous pathovars. Physical characterization of the Tn5 insertions generated by marker exchange indicated that genes controlling coronatine synthesis in P. syringae pv. atropurpurea 1304, glycinea 4180, and morsprunorum 567 and 3714 were located on the large indigenous plasmids where homology was originally detected. Therefore, coronatine biosynthesis genes are strongly conserved in the plasmid DNAs of four producing pathovars, despite their disparate origins (California, Japan, New Zealand, Great Britain, and Italy)

  18. Investigating fusion plasma instabilities in the Mega Amp Spherical Tokamak using mega electron volt proton emissions (invited)

    The proton detector (PD) measures 3 MeV proton yield distributions from deuterium-deuterium fusion reactions within the Mega Amp Spherical Tokamak (MAST). The PD’s compact four-channel system of collimated and individually oriented silicon detectors probes different regions of the plasma, detecting protons (with gyro radii large enough to be unconfined) leaving the plasma on curved trajectories during neutral beam injection. From first PD data obtained during plasma operation in 2013, proton production rates (up to several hundred kHz and 1 ms time resolution) during sawtooth events were compared to the corresponding MAST neutron camera data. Fitted proton emission profiles in the poloidal plane demonstrate the capabilities of this new system

  19. Bifurcation Analysis of a Chemostat Model of Plasmid-Bearing and Plasmid-Free Competition with Pulsed Input

    Zhong Zhao; Baozhen Wang; Liuyong Pang; Ying Chen

    2014-01-01

    A chemostat model of plasmid-bearing and plasmid-free competition with pulsed input is proposed. The invasion threshold of the plasmid-bearing and plasmid-free organisms is obtained according to the stability of the boundary periodic solution. By use of standard techniques of bifurcation theory, the periodic oscillations in substrate, plasmid-bearing, and plasmid-free organisms are shown when some conditions are satisfied. Our results can be applied to control bioreactor aimed at producing co...

  20. PcrA function in plasmid replication

    Chisty, L. T.

    2014-01-01

    PcrA is a DNA helicase involved in unwinding plasmi ds as a part of a complex in asymmetric rolling - circle replication of certain plasmids carrying antibiotic resistance genes. PcrA translocates on single stranded DNA by coupling ATP hydrolysis to movement on DNA. Initiator protein, RepD is required to nick supercoiled plasmid site - specifically and open an ssDNA stretch that PcrA can bind. The presence of RepD is needed throughout plasmid unwinding to maintain processivity. Using fluo...

  1. Complete sequences of four plasmids of Lactococcus lactis subsp. cremoris SK11 reveal extensive adaptation to the dairy environment.

    Siezen, Roland J; Renckens, Bernadet; van Swam, Iris; Peters, Sander; van Kranenburg, Richard; Kleerebezem, Michiel; de Vos, Willem M

    2005-12-01

    Lactococcus lactis strains are known to carry plasmids encoding industrially important traits. L. lactis subsp. cremoris SK11 is widely used by the dairy industry in cheese making. Its complete plasmid complement was sequenced and found to contain the plasmids pSK11A (10,372 bp), pSK11B (13,332 bp), pSK11L (47,165 bp), and pSK11P (75,814 bp). Six highly homologous repB-containing replicons were found, all belonging to the family of lactococcal theta-type replicons. Twenty-three complete insertion sequence elements segment the plasmids into numerous modules, many of which can be identified as functional units or containing functionally related genes. Plasmid-encoded functions previously known to reside on L. lactis SK11 plasmids were now mapped in detail, e.g., lactose utilization (lacR-lacABCDFEGX), the proteolytic system (prtM-prtP, pepO, pepF), and the oligopeptide permease system (oppDFBCA). Newly identified plasmid-encoded functions could facilitate the uptake of various cations, while the pabA and pabB genes could be essential for folate biosynthesis. A competitive advantage could be obtained by using the putative flavin adenine dinucleotide-dependent d-lactate dehydrogenase and oxalate:formate antiporter for enhanced ATP synthesis, while the activity of the predicted alpha-acetolactate decarboxylase may contribute to the formation of an additional electron sink. Various stress response proteins are plasmid encoded, which could enhance strain robustness. A substantial number of these "adaptation" genes have not been described before on L. lactis plasmids. Moreover, several genes were identified for the first time in L. lactis, possibly reflecting horizontal gene transfer. PMID:16332824

  2. A Functional oriT in the Ptw Plasmid of Burkholderia cenocepacia Can Be Recognized by the R388 Relaxase TrwC

    Fernández-González, Esther; Bakioui, Sawsane; Gomes, Margarida C.; O'Callaghan, David; Vergunst, Annette C.; Sangari, Félix J.; Llosa, Matxalen

    2016-01-01

    Burkholderia cenocepacia is both a plant pathogen and the cause of serious opportunistic infections, particularly in cystic fibrosis patients. B. cenocepacia K56-2 harbors a native plasmid named Ptw for its involvement in the Plant Tissue Watersoaking phenotype. Ptw has also been reported to be important for survival in human cells. Interestingly, the presence of PtwC, a homolog of the conjugative relaxase TrwC of plasmid R388, suggests a possible function for Ptw in conjugative DNA transfer. The ptw region includes Type IV Secretion System genes related to those of the F plasmid. However, genes in the adjacent region shared stronger homology with the R388 genes involved in conjugative DNA metabolism. This region included the putative relaxase ptwC, a putative coupling protein and accessory nicking protein, and a DNA segment with high number of inverted repeats and elevated AT content, suggesting a possible oriT. Although we were unable to detect conjugative transfer of the Ptw resident plasmid, we detected conjugal mobilization of a co-resident plasmid containing the ptw region homologous to R388, demonstrating the cloned ptw region contains an oriT. A similar plasmid lacking ptwC could not be mobilized, suggesting that the putative relaxase PtwC must act in cis on its oriT. Remarkably, we also detected mobilization of a plasmid containing the Ptw oriT by the R388 relaxase TrwC, yet we could not detect PtwC-mediated mobilization of an R388 oriT-containing plasmid. Our data unambiguously show that the Ptw plasmid harbors DNA transfer functions, and suggests the Ptw plasmid may play a dual role in horizontal DNA transfer and eukaryotic infection. PMID:27200362

  3. Enhanced Mission-Enabling Ultra-High Power Solar Array (Mega-ROSA EX) Project

    National Aeronautics and Space Administration — Mega-ROSA-EX is an enhanced, higher stiffness, higher sun-pointing accuracy, higher strength, higher specific power and even larger overall power / deployed size /...

  4. Mega Events and Urban Conflicts in Valencia, Spain: Contesting the New Urban Modernity

    Catherine Trudelle; Luis del Romero Renau

    2011-01-01

    The local and regional administrations of Valencia, Spain, have been working to position the city, which is the country's third largest in terms of population, as an international destination for luxury tourism through sports mega-events. Valencia's new image as a “mega-events city” has been criticized by citizens and urban-based movements on social and environmental grounds, resulting in various urban conflicts. The aim of this paper is to examine the causes and dynamics of these conflicts i...

  5. The Stabilization of High-rise Buildings : An Evaluation of the Tubed Mega Frame Concept

    Sandelin, Christian; Budajev, Evgenij

    2013-01-01

    Building tall has always been an expression of dreams, power and technical advancement. With the greatly increasing urbanization in recent years building tall has become a more viable option for office and residential housing. The Tubed mega frame concept tries to evolve the stabilizing systems of high-rise buildings with its mega frame around the buildings perimeter, created together with a new elevator system; the Articulated Funiculator. This thesis examines the effectiveness of the Tubed ...

  6. Wireless Laser Range Finder System for Vertical Displacement Monitoring of Mega-Trusses during Construction

    Hyo Seon Park; Sewook Son; Se Woon Choi; Yousok Kim

    2013-01-01

    As buildings become increasingly complex, construction monitoring using various sensors is urgently needed for both more systematic and accurate safety management and high-quality productivity in construction. In this study, a monitoring system that is composed of a laser displacement sensor (LDS) and a wireless sensor node was proposed and applied to an irregular building under construction. The subject building consists of large cross-sectional members, such as mega-columns, mega-trusses, a...

  7. The Kalimantan Border Oil Palm Mega-project

    A few years ago, the Indonesian government and sections of the palm oil industry united in the Indonesian Palm Oil Commission (IPOC) to undertake efforts to restore the atrocious public image that the palm oil industry had earned abroad for its role in the demise of Indonesia's tropical rainforests, the massive forest fires and haze in 1997-1998, and for the widespread conflicts between plantation companies and local communities. If IPOC succeeded in restoring the palm oil industry's image abroad, it was shattered again after June 2005 when the Indonesian Minister of Agriculture revealed details of a government plan to develop the world's largest oil palm plantation in a 5-10 kilometer band along the border of Kalimantan and Malaysia. To finance the USD 567 million plantation project, the Indonesian President and Chamber of Commerce and Industry (KADIN) had already met up with the Chinese government and private sector several times, resulting in Memoranda of Understanding between (among other) the Artha Graha and Sinar Mas groups from Indonesia and the Chinese CITIC group and Chinese Development Bank (CDB). The oil palm mega-project, launched in Indonesia under the banner of 'bringing prosperity, security and environmental protection to the Kalimantan border area', turned sour when a business plan developed by the Indonesian State Plantation Corporation (PTPN) began to circulate. This document contained a map that showed beyond doubt how the 1.8 million hectare oil palm project would trash the primary forests of three National Parks, cut through rugged slopes and mountains utterly unsuitable for oil palm cultivation and annihilate the customary rights land of the indigenous Dayak communities in the border area. This report describes what has come of the Kalimantan border oil palm mega-plan since it was announced, who is involved and what research, lobby and campaigning has led to so far. In particular, this study aims to inform civil society organizations, palm oil

  8. The Kalimantan Border Oil Palm Mega-project

    Wakker, E. [AIDEnvironment, Amsterdam (Netherlands)

    2006-04-15

    A few years ago, the Indonesian government and sections of the palm oil industry united in the Indonesian Palm Oil Commission (IPOC) to undertake efforts to restore the atrocious public image that the palm oil industry had earned abroad for its role in the demise of Indonesia's tropical rainforests, the massive forest fires and haze in 1997-1998, and for the widespread conflicts between plantation companies and local communities. If IPOC succeeded in restoring the palm oil industry's image abroad, it was shattered again after June 2005 when the Indonesian Minister of Agriculture revealed details of a government plan to develop the world's largest oil palm plantation in a 5-10 kilometer band along the border of Kalimantan and Malaysia. To finance the USD 567 million plantation project, the Indonesian President and Chamber of Commerce and Industry (KADIN) had already met up with the Chinese government and private sector several times, resulting in Memoranda of Understanding between (among other) the Artha Graha and Sinar Mas groups from Indonesia and the Chinese CITIC group and Chinese Development Bank (CDB). The oil palm mega-project, launched in Indonesia under the banner of 'bringing prosperity, security and environmental protection to the Kalimantan border area', turned sour when a business plan developed by the Indonesian State Plantation Corporation (PTPN) began to circulate. This document contained a map that showed beyond doubt how the 1.8 million hectare oil palm project would trash the primary forests of three National Parks, cut through rugged slopes and mountains utterly unsuitable for oil palm cultivation and annihilate the customary rights land of the indigenous Dayak communities in the border area. This report describes what has come of the Kalimantan border oil palm mega-plan since it was announced, who is involved and what research, lobby and campaigning has led to so far. In particular, this study aims to inform civil

  9. Plasmids as Tools for Containment.

    García, José L; Díaz, Eduardo

    2014-10-01

    Active containment systems are a major tool for reducing the uncertainty associated with the introduction of monocultures, genetically engineered or not, into target habitats for a large number of biotechnological applications (e.g., bioremediation, bioleaching, biopesticides, biofuels, biotransformations, live vaccines, etc.). While biological containment reduces the survival of the introduced organism outside the target habitat and/or upon completion of the projected task, gene containment strategies reduce the lateral spread of the key genetic determinants to indigenous microorganisms. In fundamental research, suicide circuits become relevant tools to address the role of gene transfer, mainly plasmid transfer, in evolution and how this transfer contributes to genome plasticity and to the rapid adaptation of microbial communities to environmental changes. Many lethal functions and regulatory circuits have been used and combined to design efficient containment systems. As many new genomes are being sequenced, novel lethal genes and regulatory elements are available, e.g., new toxin-antitoxin modules, and they could be used to increase further the current containment efficiencies and to expand containment to other organisms. Although the current containment systems can increase the predictability of genetically modified organisms in the environment, containment will never be absolute, due to the existence of mutations that lead to the appearance of surviving subpopulations. In this sense, orthogonal systems (xenobiology) appear to be the solution for setting a functional genetic firewall that will allow absolute containment of recombinant organisms. PMID:26104372

  10. Plasmid DNA fermentation strategies: influence on plasmid stability and cell physiology.

    Silva, Filomena; Queiroz, João A; Domingues, Fernanda C

    2012-03-01

    In order to provide sufficient pharmaceutical-grade plasmid DNA material, it is essential to gain a comprehensive knowledge of the bioprocesses involved; so, the development of protocols and techniques that allow a fast monitoring of process performance is a valuable tool for bioprocess design. Regarding plasmid DNA production, the metabolic stress of the host strain as well as plasmid stability have been identified as two of the key parameters that greatly influence plasmid DNA yields. The present work describes the impact of batch and fed-batch fermentations using different C/N ratios and different feeding profiles on cell physiology and plasmid stability, investigating the potential of these two monitoring techniques as valuable tools for bioprocess development and design. The results obtained in batch fermentations showed that plasmid copy number values suffered a pronounced increase at the end of almost all fermentation conditions tested. Regarding fed-batch fermentations, the strategies with exponential feeding profiles, in contrast with those with constant feeding, showed higher biomass and plasmid yields, the maximum values obtained for these two parameters being 95.64 OD(600) and 344.3 mg plasmid DNA (pDNA)/L, respectively, when using an exponential feed rate of 0.2 h(-1). Despite the results obtained, cell physiology and plasmid stability monitoring revealed that, although higher pDNA overall yields were obtained, this fermentation exhibited lower plasmid stability and percentage of viable cells. In conclusion, this study allowed clarifying the bioprocess performance based on cell physiology and plasmid stability assessment, allowing improvement of the overall process and not only plasmid DNA yield and cell growth. PMID:22089386

  11. Enhancement of plasmid-mediated gene therapy for muscular dystrophy by directed plasmid integration

    Bertoni, Carmen; Jarrahian, Sohail; Wheeler, Thurman M.; LI, YINING; Olivares, Eric C.; Michele P Calos; Rando, Thomas A.

    2005-01-01

    Plasmid-mediated gene therapy can restore dystrophin expression in skeletal muscle in the mdx mouse, a model of Duchenne muscular dystrophy. However, sufficient long-term expression and distribution of dystrophin remain a hurdle for translating this technology into a viable treatment for Duchenne muscular dystrophy. To improve plasmid-mediated gene therapy for muscle diseases, we studied the effects of targeted plasmid integration using a phage integrase (φC31) that can mediate the integratio...

  12. Conjugal mobilization of the mega element carrying mef(E) from Streptococcus salivarius to Streptococcus pneumoniae.

    Santagati, Maria; Lupo, Agnese; Scillato, Marina; Di Martino, Andrea; Stefani, Stefania

    2009-01-01

    We report the isolation and characterization of an unusual strain of Streptococcus salivarius, 3C30, displaying both the macrolide-lincosamide-streptogramin B and the tetracycline resistance phenotypes. It harbours the mef(E), erm(B), and tet(M) genes carried by different genetic elements. The genetic element carrying mef(E), named mega, was investigated by long PCR and sequencing, while the presence of the Tn3872-like element, carrying tet(M) and erm(B), was demonstrated by sequencing of both the int-xis-Tn and the fragment between the two resistance genes. In strain 3C30 the mega element is 5388 bp in size and its nucleotide sequence is identical to that of the element described previously in S. salivarius, with the exception of a 912 bp deletion at the left end. The composite Tn3872-like element appeared to be nonconjugative while the mega element was transferred by conjugation to Streptococcus pneumoniae. It was, however, impossible to transfer it again from these transconjugants to other strains. In addition, only in the 3C30 strain did mega form circular structures, as identified by real-time PCR. In conclusion, we found a clinical strain of S. salivarius carrying both mega and Tn3872-like genetic elements. Mega is transferable by conjugation to S. pneumoniae but it is not transferable again from the transconjugants, suggesting a possible mobilization by recombinases of the coresident Tn3872-like transposon. PMID:19025575

  13. Elimination of multicopy plasmid R6K by bleomycin.

    Attfield, P V; Pinney, R. J.

    1985-01-01

    Bleomycin eliminated multicopy plasmid R6K from growing cells of Escherichia coli AB1157 but failed to cure either of the low-copy plasmids R1 or R46. Measurements of R6K-encoded beta-lactamase and of covalently closed plasmid DNA indicated that the drug causes a progressive reduction in plasmid copy number.

  14. Behavior of IncQ Plasmids in Agrobacterium tumefaciens

    Hille, Jacques; Schilperoort, Rob

    1981-01-01

    Inc-Q plasmids were introduced into Agrobacterium tumefuciens, by mobilization from Escherichia coli with an Inc-P plasmid, or by transformation with purified plasmid DNA. It was found that they were stably maintained. The presence of an Inc-Q plasmid did not influence tumorigenicity. These results

  15. Curing of plasmid pXO1 from Bacillus anthracis using plasmid incompatibility.

    Xiankai Liu

    Full Text Available The large plasmid pXO1 encoding the anthrax toxin is important for the virulence of Bacillus anthracis. It is essential to cure pXO1 from B. anthracis to evaluate its role in the pathogenesis of anthrax infection. Because conventional methods for curing plasmids (e.g., curing agents or growth at elevated temperatures can induce mutations in the host chromosomal DNA, we developed a specific and reliable method to eliminate pXO1 from B. anthracis using plasmid incompatibility. Three putative replication origins of pXO1 were inserted into a temperature-sensitive plasmid to generate three incompatible plasmids. One of the three plasmids successfully eliminated the large plasmid pXO1 from B. anthracis vaccine strain A16R and wild type strain A16. These findings provided additional information about the replication/partitioning of pXO1 and demonstrated that introducing a small incompatible plasmid can generate plasmid-cured strains of B. anthracis without inducing spontaneous mutations in the host chromosome.

  16. Positive epistasis between co-infecting plasmids promotes plasmid survival in bacterial populations

    San Millan, Alvaro; Heilbron, Karl; MacLean, R. Craig

    2014-01-01

    Plasmids have a key role in the horizontal transfer of genes among bacteria. Although plasmids are catalysts for bacterial evolution, it is challenging to understand how they can persist in bacterial populations over the long term because of the burden they impose on their hosts (the ‘plasmid paradox'). This paradox is especially perplexing in the case of ‘small' plasmids, which are unable to self-transfer by conjugation. Here, for the first time, we investigate how interactions between co-in...

  17. Mini-F plasmid genes that couple host cell division to plasmid proliferation.

    Ogura, T; Hiraga, S

    1983-01-01

    A mechanism for stable maintenance of plasmids, besides the replication and partition mechanisms, has been found to be specified by genes of a mini-F plasmid. An oriC plasmid carrying both a mini-F segment necessary for partition [coordinates 46.4-49.4 kilobase pairs (kb) on the F map] and another segment (42.9-43.6 kb), designated ccd (coupled cell division), is more stably maintained than are oriC plasmids carrying only the partition segment; the stability is comparable to that of the paren...

  18. Adaptive Plasmid Evolution Results in Host-Range Expansion of a Broad-Host-Range Plasmid

    De Gelder, Leen; Williams, Julia J.; Ponciano, José M; Sota, Masahiro; Eva M. Top

    2008-01-01

    Little is known about the range of hosts in which broad-host-range (BHR) plasmids can persist in the absence of selection for plasmid-encoded traits, and whether this “long-term host range” can evolve over time. Previously, the BHR multidrug resistance plasmid pB10 was shown to be highly unstable in Stenotrophomonas maltophilia P21 and Pseudomonas putida H2. To investigate whether this plasmid can adapt to such unfavorable hosts, we performed evolution experiments wherein pB10 was maintained ...

  19. Characterization of a Haemophilus ducreyi mobilizing plasmid.

    McNicol, P J; Albritton, W L; Ronald, A R

    1986-01-01

    The OriV site of Haemophilus ducreyi mobilizing plasmid pHD147, determined by replication in Escherichia coli polA, is located close to the OriT site. The OriT site, located by recombination-proficient and -deficient cells, and the OriV site map in a region of pHD147 homologous to the beta-lactamase-specifying plasmids of H. ducreyi and Neisseria gonorrhoeae.

  20. Plasmid and chromosome segregation in prokaryotes

    Møller-Jensen, Jakob; Bugge Jensen, Rasmus; Gerdes, Kenn

    2000-01-01

    Recent major advances in the understanding of prokaryotic DNA segregation have been achieved by using fluorescence microscopy to visualize the localization of cellular components. Plasmids and bacterial chromosomes are partitioned in a highly dynamic fashion, suggesting the presence of a mitotic......-like apparatus in prokaryotes. The identification of chromosomal homologues of the well-characterized plasmid partitioning genes indicates that there could be a general mechanism of bacterial DNA partitioning. Udgivelsesdato: July 1...

  1. Plasmid Evolution and Interaction between the Plasmid Addiction Stability Systems of Two Related Broad-Host-Range IncQ-Like Plasmids

    Deane, Shelly M.; Rawlings, Douglas E

    2004-01-01

    Plasmid pTC-F14 contains a plasmid stability system called pas (plasmid addiction system), which consists of two proteins, a PasA antitoxin and a PasB toxin. This system is closely related to the pas of plasmid pTF-FC2 (81 and 72% amino acid identity for PasA and PasB, respectively) except that the pas of pTF-FC2 contains a third protein, PasC. As both pTC-F14 and pTF-FC2 are highly promiscuous broad-host-range plasmids isolated from bacteria that share a similar ecological niche, the plasmid...

  2. Mega-History and the 21st century singularity puzzle

    Akop P. Nazaretyan

    2015-06-01

    Full Text Available A series of calculations carried out independently by the Australian, Russian and American re- searchers have demonstrated that a crucial global polyfurcation is expected near the middle of the 21st century. This result is drawn by extrapolating into the future the logarithmic acceleration law, which involves the phase transitions in the evolution of biosphere and anthroposphere. The paper investigates the palliatives of the planetary civilization beyond the big evolutionary Singularity in the context of Mega-history and complexity theory worldviews. It gives the mathematical deduction a universal ground and besides, helps involve some recent discoveries in psychology and cultural anthropology to tracing the forecasting attractors and scenarios. The destiny of the Earth (as well as any other planetary civilization may conclusively depend on whether or not the intellectual ac- tor succeeds in developing his inner regulation to balance the potentially unlimited developments in technological power. Particularly, this includes overcoming the macro-group identities, religious and quasi-religious ideologies, which always suggest a friend-or-foe discrimination matrix.

  3. Beyond the MEGA BORG: The future of cooperative damage assessments

    Prespill planning and coordination are the major requirements of industry and government to ensure future cooperative natural resource damage assessments (NRDA). Since oil spills most often occur without warning, both parties must be prepared prior to an oil spill into the environment. Federal and State co-trustees should enter into a Memorandum of Understanding (MOU) to ensure cooperation and coordination among trustees in all NRDA activities. The MOU should provide the framework whereby each trustee's resource interests can be represented. Ideally, MOUs should be prepared during the prespill planning process, although the MEGA BORG MOU was prepared soon after the actual discharge. The establishment of co-trustee working groups will foster the positive working relationships necessary in cooperative NRDAs. The trustees should identify all potential co-trustees in a given area and agree on a mechanism for trustee notification. Criteria for the rapid designation of the Lead Administrative Trustee and approaches for coordination with response agencies and potential responsible parties (PRPs) need to be developed. Most importantly, the trustees should identify PRPs and invite their participation in the prespill planning process

  4. Mega-mergers in the pharmaceutical industry. In whose interests?

    Po, A L

    1998-10-01

    Companies merge to achieve economies of scale. In an industry such as the pharmaceutical industry which relies on a high level of investment in research and development, such mergers appear rational. However, it is not at all obvious that a higher level of investment by a smaller number of firms will necessarily lead to an increased rate of genuine innovations. There is a risk that conflicts of interest and the pursuit of short term gains may encourage more mergers than is optimal for the industry. The impact of mega-mergers in the pharmaceutical industry on research output, employees, shareholders, financial advisers, managers and patients is discussed. A healthy pharmaceutical industry, able to invest the necessary resources in the development of innovative medicines is in the interest of patients and shareholders alike. Over-concentration may interfere with innovative activity and lead to monopolistic power. Close scrutiny of merger activity is important but in a deregulated world, governments may have little power to act. In any case, a drug-specific monopolistic industry may be beneficial to some countries which may therefore be reluctant to act in the interest of the world as a single community in search of more effective medicines. PMID:10344903

  5. FCC resid processing

    This paper narrows the definition of reside processor to those FCC's which run feedstocks containing 1 wt.% or more Conradson carbon residue. With this new definition, the resid survey is revisited to see if any new conclusions can be drawn from the data. The authors break down the numbers and geography of resid processors, feed types, operating variables, and yields. After examining the state of resid processing in the FCC, the paper focuses on the design of cracking catalysts for handling resid feeds. There are important considerations involved in processing resid including high levels of contaminants such as vanadium and nickel, the impact on heat balance, and diffusion effects. Catalysts can be designed to improve the profitability of a resid operation. A clear picture of the roles of zeolite and matrix is presented, along with a discussion of the different types of zeoliters which are commonly used. The paper demonstrates how zeolite and matrix are best combined to meet objectives within a given set of constraints while processing resid

  6. Relationship between plasmid content and auxotype in Neisseria gonorrhoeae isolates.

    Dillon, J R; Pauzé, M

    1981-01-01

    One hundred and forty strains of Neisseria gonorrhoeae, representing 12 different auxotype groups, were examined for differences in plasmid content. Most auxotype groups harbored a phenotypically cryptic 2,6-megadalton plasmid; a few groups also carried a 24.5-megadalton plasmid which has been previously characterized as a transfer plasmid. However, isolates of the proline-, citrulline-, and uracil-requiring (PCU-) auxotype were consistently free of plasmids. The correlation between auxotype ...

  7. Plasmid stability and maintenance of copy number using natural marker

    Hamzah Basil Mohammed; Sudhakar Malla

    2015-01-01

    Present study was conducted to study the plasmid stability with the help of natural plasmid isolated from the bacteria which lodges the ink gland of the sea squid and emits bioluminescence. Isolated bacterial strain was identified by using 16srRNA sequencing and its plasmid DNA was used for the experimental studies. The plasmid is found to be responsible for the bioluminescence. The stability of this plasmid was studied in shake flask method using the different sugar sources (Gluc...

  8. Plasmids spread very fast in heterogeneous bacterial communities.

    Dionisio, Francisco; Matic, Ivan; Radman, Miroslav; Rodrigues, Olivia R; Taddei, François

    2002-01-01

    Conjugative plasmids can mediate gene transfer between bacterial taxa in diverse environments. The ability to donate the F-type conjugative plasmid R1 greatly varies among enteric bacteria due to the interaction of the system that represses sex-pili formations (products of finOP) of plasmids already harbored by a bacterial strain with those of the R1 plasmid. The presence of efficient donors in heterogeneous bacterial populations can accelerate plasmid transfer and can spread by several order...

  9. Plasmid Segregation: Spatial Awareness at the Molecular Level

    Møller-Jensen, Jakob; Gerdes, Kenn

    2007-01-01

    In bacteria, low-copy number plasmids ensure their stable inheritance by partition loci (par), which actively distribute plasmid replicates to each side of the cell division plane. Using time-lapse fluorescence microscopic tracking of segregating plasmid molecules, a new study provides novel...... insight into the workings of the par system from Escherichia coli plasmid R1. Despite its relative simplicity, the plasmid partition spindle shares characteristics with the mitotic machinery of eukaryotic cells....

  10. Mobilization of Thiobacillus ferrooxidans plasmids among Escherichia coli strains.

    Rawlings, D. E.; Woods, D R

    1985-01-01

    Nonconjugative Thiobacillus ferrooxidans plasmids were mobilized at high frequencies among Escherichia coli strains by the IncP plasmid RP4 and at low frequencies by the IncN plasmid R46, but not by the IncW plasmid pSa. The mobilization region of a nonconjugative T. ferrooxidans plasmid was located on a 5.3-kilobase T. ferrooxidans DNA fragment.

  11. Isolation of a Pseudomonas Stutzeri strain that degrades1, 2, 4-trichlorobenzene and characterization of its degradative plasmid

    Lei SONG; Hui WANG; Hanchang SHI; Hongying HU

    2008-01-01

    The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids. The aim of the present work was to know the location of the genes for degrading 1, 2, 4-trichlorobenzen. In this paper a 1, 2, 4-trichlorobenzene-degrading strain THSL-1 was isolated from the soil of Tianjin Chemical Plant using 1, 2, 4-trichlorobenzene as the sole carbon source. The strain was identified as Pseudomonas stutzeri through morphologic survey and 16S rDNA sequence determination. A plasmid was discovered from strain THSL-1 by using the alkali lysis method. When the plasmid was transformed into E. coli. JM109 by the CaCl2 method, the transformant could grow using 1, 2, 4-trichlorobenzene as the sole carbon source and had the degradation function of 1, 2, 4-trichlorobenzene. Therefore, it could be deemed that the plasmid carried the degradative genes of 1, 2, 4-trichlorobenzene. The average size of the plasmid was finally determined to be 40.2 Kb using selectively three kinds of restricted inscribed enzymes (HindIII, BamHI, and XholI) for single cutting and double cutting the plasmid pTHSL-1, respectively.

  12. Inducible Escherichia coli fermentation for increased plasmid DNA production.

    Carnes, Aaron E; Hodgson, Clague P; Williams, James A

    2006-11-01

    Bacterial plasmids are the vectors of choice for DNA vaccines and short-term gene therapeutics. Growing plasmid DNA by microbial (Escherichia coli) fermentation is usually combined with alkaline lysis/chromatography methods of purification. To date, typical plasmid fermentation media and processes result in yields of 100-250 mg of plasmid DNA/l of culture medium, using standard high-copy pUC origin-containing plasmids. In order to address this initial and yield-limiting upstream step, we identified novel fermentation control parameters for fed-batch fermentation. The resulting fermentation strategies significantly increased specific plasmid yield with respect to cell mass while enhancing plasmid integrity and maintaining supercoiled DNA content. Fed-batch fermentation yield exceeding 1000 mg of plasmid DNA/l was obtained after reduction of plasmid-mediated metabolic burden during growth, and yields up to 1500 mg of plasmid DNA/l have been achieved with optimized plasmid backbones. Interestingly, by inducing high plasmid levels after sufficient biomass accumulation at low temperature and restricted growth, cells were able to tolerate significantly higher plasmid quantities than cells grown by conventional processes. This 5-10-fold increase in plasmid yield dramatically decreases plasmid manufacturing costs and improves the effectiveness of downstream purification by reducing the fraction of impurities. PMID:16819941

  13. Conservation of Salmonella typhimurium virulence plasmid maintenance regions among Salmonella serovars as a basis for plasmid curing.

    Tinge, S A; Curtiss, R

    1990-01-01

    The association of large plasmids with virulence in invasive Salmonella serovars has led to a number of studies designed to uncover the role of these plasmids in virulence. This study addresses two aspects of virulence-associated plasmids. The first is the distribution of the replication and maintenance regions among the plasmids of different Salmonella serovars, and the second is the use of the conserved virulence plasmid par region to provide a rapid method for eliminating the virulence pla...

  14. BioShuttle-mediated Plasmid Transfer

    Klaus Braun, Leonie von Brasch, Ruediger Pipkorn, Volker Ehemann, Juergen Jenne, Herbert Spring, Juergen Debus, Bernd Didinger, Werner Rittgen, Waldemar Waldeck

    2007-01-01

    Full Text Available An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantification of the transfer efficiency was achieved by measurements of the sodium iodide symporter activity. EGFP gene expression was measured with Confocal Laser Scanning Microscopy and quantified with biostatistical methods by analysis of the frequency of the amplitude distribution in the CLSM images. The results demonstrate that the “BioShuttle”-Technology is an appropriate tool for an effective transfer of genetic material carried by a plasmid.

  15. BioShuttle-mediated Plasmid Transfer

    Braun, Klaus; von Brasch, Leonie; Pipkorn, Ruediger; Ehemann, Volker; Jenne, Juergen; Spring, Herbert; Debus, Juergen; Didinger, Bernd; Rittgen, Werner; Waldeck, Waldemar

    2007-01-01

    An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantification of the transfer efficiency was achieved by measurements of the sodium iodide symporter activity. EGFP gene expression was measured with Confocal Laser Scanning Microscopy and quantified with biostatistical methods by analysis of the frequency of the amplitude distribution in the CLSM images. The results demonstrate that the “BioShuttle”-Technology is an appropriate tool for an effective transfer of genetic material carried by a plasmid. PMID:18026568

  16. Burnout among Dutch medical residents

    Prins, J.T.; Hoekstra-Weebers, J.E.; van de Wiel, H.B.; Gazendam-Donofrio, S.M.; Sprangers, F.; Jaspers, F.C.; van der Heijden, F.M.

    2007-01-01

    We examined levels of burnout and relationships between burnout, gender, age, years in training, and medical specialty in 158 medical residents working at the University Medical Center Groningen, the Netherlands. Thirteen percent of the residents met the criteria for burnout, with the highest percentage of burnout cases among medical residents in Psychiatry. Significantly more male residents than female residents suffered from severe burnout. Medical residents reported significantly lower mea...

  17. Electrotransfer of Plasmid Vector DNA into Muscle

    Miyazaki, Satsuki; Miyazaki, Jun-Ichi

    Wolff et al. (1990) first reported that plasmid DNA injected into skeletal muscle is taken up by muscle cells and the genes in the plasmid are expressed for more than two months thereafter, although the transfected DNA does not usually undergo chromosomal integration (Wolff et al., 1991, 1992). However, the relatively low expression levels attained by this method have hampered its applications for uses other than as a DNA vaccine (Davis et al., 1995). There are a number of reports analyzing the conditions that affect the efficiency of gene transfer by intramuscular DNA injection and assessing the fine structures of expression plasmid vectors that may affect expression levels (Davis et al., 1993; Liang et al., 1996; Norman et al., 1997). Furthermore, various attempts were done to improve the efficiency of gene transfer by intramus cular DNA injection. Consequently, regenerating muscle was shown to produce 80-fold or more protein than did normal muscle, following injection of an expression plas-mid. Muscle regeneration was induced by treatment with cardiotoxin or bupivacaine (Wells, 1993; Vitadello et al., 1994). We previously demonstrated that by combining a strong promoter and bupivacaine pretreatment intramuscular injection of an IL-5 expression plasmid results in IL-5 production in muscle at a level sufficient to induce marked proliferation of eosinophils in the bone marrow and eosinophil infiltration of various organs (Tokui et al., 1997). It was also reported that a single intramuscular injection of an erythropoietin expression plasmid produced physiologically significant elevations in serum erythropoietin levels and increased hematocrits in adult mice (Tripathy et al., 1996). Hematocrits in these animals remained elevated at >60% for at least 90 days after a single injection. However, improvements to this method have not been sufficient to extend its applications including clinical use.

  18. BioShuttle-mediated Plasmid Transfer

    Braun, Klaus; von Brasch, Leonie; Pipkorn, Ruediger; Ehemann, Volker; Jenne, Juergen; Spring, Herbert; Debus, Juergen; Didinger, Bernd; Rittgen, Werner; Waldeck, Waldemar

    2007-01-01

    An efficient gene transfer into target tissues and cells is needed for safe and effective treatment of genetic diseases like cancer. In this paper, we describe the development of a transport system and show its ability for transporting plasmids. This non-viral peptide-based BioShuttle-mediated transfer system consists of a nuclear localization address sequence realizing the delivery of the plasmid phNIS-IRES-EGFP coding for two independent reporter genes into nuclei of HeLa cells. The quantif...

  19. Improvement of Performance of MegaBlast Algorithm for DNA Sequence Alignment

    Guang-Ming Tan; Lin Xu; Dong-Bo Bu; Sheng-Zhong Feng; Ning-Hui Sun

    2006-01-01

    MegaBlast is one of the most important programs in NCBI BLAST (Basic Local Alignment Search Tool)toolkits. However, MegaBlast is computation and I/O intensive. It consumes a great deal of memory which is proportional to the size of the query sequences set and subject (database) sequences set of product. This paper proposes a new strategy for optimizing MegaBlast. The new strategy exchanges the query and subject sequences sets, and builds a hash table based on new subject sequences. It overlaps I/O with computation, shortens the overall time and reduces the cost of memory,since the memory here is only proportional to the size of subject sequences set. The optimized algorithm is suitable to be parallelized in cluster systems. The parallel algorithm uses query segmentation method. As our experiments shown, the parallel program which is implemented with MPI has fine scalability.

  20. Shear viscosity of shocked metals at mega-bar pressures

    Liu, Fu-Sheng

    2013-06-01

    Viscosity of metals at high pressures and temperatures has been one of the most concerned problems in weapon physics and geophysics, e.g., the shear viscosity coefficients of substances in earth's mantle and earth's core at mega-bar pressures are needed for understanding the core mantle convection in deep earth. But the experimental data is very scarce because the conventional measurement methods can hardly be applied to such compression conditions [1]. In this talk, the principle of small-disturbance perturbation method [2] is re-investigated based on both the analytic solution and the numerical solution of the two-dimentional shock flow of sinusoidal distubance on front. In numerical solution, the real viscosity, which governs the flow behind the shock front and the perturbation damping feature, and the artificial viscosity, whick controls the numerical oscillation, separately treated. The relation between the viscosity of flow and the damping features of perturbation amplitude is quantitatively established for the loading situations of Sakharov's [3] and a flyer-impact situation with a finite disturbance. The later is the theoretical basis to develop a new experimental method, called the flyer-impact small-disturbance method [4]. In the flyer-impact small-disturbance method, the two-stage light-gas gun is used to launch a metal flyer. When the flyer directly impacts on the wedge-shaped sample with a sinusoidal surface, a two-dimensional shock flow of sinusoidal distubance on its front is generated. The amplitude of disturbance and its dependance with propagation distance is measured by use of an electric pin-array probe or a fibre-array probe. Correspondingly, the solution of the flow is given by numerically solving the hydrodynamic equations by the finite difference technique to find out the quantative correlations among the amplitude decay, the initial distribution of flow, the amplitude of initial disturbance, the shear viscosity of the flow, and the material

  1. Competition between Plasmid-Bearing and Plasmid-Free Organisms in a Chemostat with Pulsed Input and Washout

    Sanling Yuan

    2009-01-01

    Full Text Available We consider a model of competition between plasmid-bearing and plasmid-free organisms in the chemostat with pulsed input and washout. We investigate the subsystem with nutrient and plasmid-free organism and study the stability of the boundary periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields the invasion threshold of the plasmid-bearing organism. By using the standard techniques of bifurcation theory, we prove that above this threshold there are periodic oscillations in substrate, plasmid-free, and plasmid-bearing organisms. Numerical simulations are carried out to illustrate our results.

  2. Plasmid maintenance functions of the large virulence plasmid of Shigella flexneri.

    Radnedge, L; Davis, M. A.; Youngren, B; Austin, S. J.

    1997-01-01

    The large virulence plasmid pMYSH6000 of Shigella flexneri contains a replicon and a plasmid maintenance stability determinant (Stb) on adjacent SalI fragments. The presence of a RepFIIA replicon on the SalI C fragment was confirmed, and the complete sequence of the adjacent SalI O fragment was determined. It shows homology to part of the transfer (tra) operon of the F plasmid. Stb stabilizes a partition-defective P1 miniplasmid in Escherichia coli. A 1.1-kb region containing a homolog of the...

  3. Plasmid transfer and plasmid-mediated genetic exchange in Brucella abortus.

    Rigby, C E; Fraser, A.D.

    1989-01-01

    Naturally-occurring plasmids and gene transfer mechanisms have not yet been reported in brucellae. Here we show that Brucella abortus is capable of maintaining and transferring the broad-host-range plasmids pTH10 (IncP), pSa (IncW) and R751 (IncP), and describe pTH10-mediated transfer of B. abortus chromosomal genes to Escherichia coli. All three plasmids transferred by conjugation from E. coli to B. abortus S19, and from B. abortus S19 to B. abortus 292 (biovar 4). They were stably maintaine...

  4. Plasmid transduction by Bacillus subtilis bacteriophage SPP1: effects of DNA homology between plasmid and bacteriophage.

    Deichelbohrer, I; Alonso, J.C.; Lüder, G; Trautner, T A

    1985-01-01

    Any SPP1 DNA restriction fragment cloned into Bacillus subtilis plasmid pC194 or pUB110 increased the transduction frequency of the plasmid by SPP1 100- to 1,000-fold over the transduction level of the plasmid alone. This increment was observed irrespective of whether a fragment contained the SPP1 packaging origin (pac). Furthermore, an SPP1 derivative into whose genome pC194 DNA had been integrated transduced pC194 DNA with a greatly enhanced frequency. Transduction enhancement mediated by D...

  5. Challenges to publishing pharmacy resident research projects from the perspectives of residency program directors and residents

    Olson KL; Irwin AN; Joline BR; Witt DM; Patel RJ

    2013-01-01

    Objective: To identify barriers to completing and publishing pharmacy residency research projects from the perspective of program directors and former residents.Methods: This was a cross-sectional survey of pharmacy residency program directors and former post-graduate year one and two residents. Directors of pharmacy residency programs whose residents present their projects at the Western States Conference (n=216) were invited to complete an online survey and asked to forward the survey to fo...

  6. Identification, characterization and preliminary X-ray diffraction analysis of the rolling-circle replication initiator protein from plasmid pSTK1

    A proteolytically stable fragment of a plasmid replication initiation protein from the thermophile G. stearothermophilus has been biochemically characterized, crystallized and diffraction data collected to a resolution of 2.5 Å. Antibiotic resistance in bacterial pathogens poses an ever-increasing risk to human health. In antibiotic-resistant strains of Staphylococcus aureus this resistance often resides in extra-chromosomal plasmids, such as those of the pT181 family, which replicate via a rolling-circle mechanism mediated by a plasmid-encoded replication initiation protein. Currently, there is no structural information available for the pT181-family Rep proteins. Here, the crystallization of a catalytically active fragment of a homologous replication initiation protein from the thermophile Geobacillus stearothermophilus responsible for the replication of plasmid pSTK1 is reported. Crystals of the RepSTK1 fragment diffracted to a resolution of 2.5 Å and belonged to space group P212121

  7. Changes in medicine: residency

    Robbins RA

    2011-07-01

    Full Text Available No abstract available. Article truncated at 150 words. The most important time in a physician’s educational development is residency, especially the first year. However, residency work and responsibility have come under the scrutiny of a host of agencies and bureaucracies, and therefore, is rapidly changing. Most important in the alphabet soup of regulatory agencies is the Accreditation Council for Graduate Medical Education (ACGME which accredits residencies and ultimately makes the governing rules.Resident work hours have received much attention and are clearly decreasing. However, the decline in work hours began in the 1970’s before the present political push to decrease work hours. The residency I entered in 1976 had every third night call during the first year resident’s 6-9 months on general medicine or wards. It had changed from every other night the year before. On wards, we normally were in the hospital for our 24 hours of call and followed this with a 10-12 hour day before …

  8. Development of large area resistive electrodes for ATLAS NSW MicroMEGAS

    Ochi, Atsuhiko; The ATLAS collaboration

    2015-01-01

    MicroMegas with resistive anode will be used for the NSW upgrade of the ATLAS experiment at LHC. The resistive electrode is one of key technology for MPGDs to prevent sparks. Large area resistive electrodes for the MM have been developed using two different technology; screen printing and carbon sputtering. Maximum size of each resistive foil is 45cm x 220cm with printed pattern of 425 micron pitch strips. Those technologies are also suitable to mass production. The prototypes of series production model have been produced successfully. We will report the development and production status and test results of the resistive MicroMegas.

  9. Mega sporting events: A poisoned chalice or a new dawn for low- and middle-income

    Mark Tomlinson

    2011-06-01

    Full Text Available Mega sporting events in South Africa, which has the largest number of HIV-positive people in the world, and India, with 1.8 million deaths of children under 5 each year and 52 million stunted children, raise questions about the effective and, as importantly, the moral imperative of spending billions of dollars to host a sporting event. From a health perspective, selling alcohol and debt tarnishes further the notion of any intangible benefits of mega events to low- and middle-income countries.

  10. Plasmid maintenance and protein overproduction in selective recycle bioreactors.

    Ogden, K L; Davis, R H

    1991-02-20

    A new plasmid construct has been used in conjunction with selective recycle to successfully maintain otherwise unstable plasmid-bearing E. coli cells in a continuous bioreactor and to produce significant amounts of the plasmid-encoded protein beta-lactamase. The plasmid is constructed so that pilin expression, which leads to bacterial flocculation, is under control of the tac operon. The plasmid-bearing cells are induced to flocculate in the separator, whereas cell growth and product synthesis occur in the main fermentation vessel without the inhibiting effects of pilin production. Selective recycle allows for the maintenance of the plasmid-bearing cells by separating flocculent, plasmid-bearing cells from nonflocculent, segregant cells in an inclined settler, and recycling only the plasmid-bearing cells to the reactor. As a result, product expression levels are maintained that are more than ten times the level achieved without selective recycle. All experimental data agree well with theoretical predictions. PMID:18597374

  11. Simple method for identification of plasmid-coded proteins

    Proteins encoded by plasmid DNA are specifically labeled in uv-irradiated cells of Escherichia coli carrying recA and uvrA mutations because extensive degradation of the chromosome DNA occurs concurrently with amplification of plasmid DNA

  12. DISTRIBUTION OF PLASMIDS IN GROUNDWATER BACTERIA

    Bacteria isolated from groundwater aquifer core materials of pristine aquifers at Lula and Pickett, Oklahoma, and from a site with a history of aromatic hydrocarbon contamination and natural renovation located at Conroe, Texas, were screened for the presence of plasmid Deoxyribon...

  13. Plasmid mediated quinolone resistance in Enterobacteriaceae

    Veldman, K.T.

    2014-01-01

    This thesis describes the occurrence of Plasmid Mediated Quinolone Resistance (PMQR) in Salmonella and E. coli from The Netherlands and other European countries. Furthermore, the genetic background of these genes was characterized. Fluoroquinolones are widely used antibiotics in both human and veter

  14. The influence of biofilms in the biology of plasmids

    Cook, Laura C.C.; Dunny, Gary M.

    2014-01-01

    The field of plasmid biology has historically focused on bacteria growing in liquid culture. Surface attached communities of bacterial biofilms have recently been understood to be the normal environment of bacteria in the natural world. Thus, studies examining plasmid replication, maintenance, and transfer in biofilms are essential for a true understanding of bacterial plasmid biology. This chapter reviews the current knowledge of the interplay between bacterial biofilms and plasmids, focusin...

  15. The 2 micron plasmid purloins the yeast cohesin complex

    Mehta, Shwetal; Yang, Xian Mei; Chan, Clarence S.; Dobson, Melanie J.; Jayaram, Makkuni; Velmurugan, Soundarapandian

    2002-01-01

    The yeast 2 micron plasmid achieves high fidelity segregation by coupling its partitioning pathway to that of the chromosomes. Mutations affecting distinct steps of chromosome segregation cause the plasmid to missegregate in tandem with the chromosomes. In the absence of the plasmid stability system, consisting of the Rep1 and Rep2 proteins and the STB DNA, plasmid and chromosome segregations are uncoupled. The Rep proteins, acting in concert, recruit the yeast cohesin complex to the STB locu...

  16. Linear and Circular Plasmid Content in Borrelia burgdorferi Clinical Isolates

    Iyer, Radha; Kalu, Ogori; Purser, Joye; Norris, Steven; Stevenson, Brian; Schwartz, Ira

    2003-01-01

    The genome of Borrelia burgdorferi, the etiologic agent of Lyme disease, is composed of a linear chromosome and more than 20 linear and circular plasmids. Typically, plasmid content analysis has been carried out by pulsed-field gel electrophoresis and confirmed by Southern hybridization. However, multiple plasmids of virtually identical sizes (e.g., lp28 and cp32) complicate the interpretation of such data. The present study was undertaken to investigate the complete plasmid complements of B....

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

    Dowty, M E; Williams, P; Zhang, G.; 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...

  18. Postsegregational killing does not increase plasmid stability but acts to mediate the exclusion of competing plasmids

    Cooper, Tim F; Heinemann, Jack A.

    2000-01-01

    Postsegregational killing (PSK) systems consist of a tightly linked toxin–antitoxin pair. Antitoxin must be continually produced to prevent the longer lived toxin from killing the cell. PSK systems on plasmids are widely believed to benefit the plasmid by ensuring its stable vertical inheritance. However, experimental tests of this “stability” hypothesis were not consistent with its predictions. We suggest an alternative hypothesis to explain the evolution of PSK: ...

  19. Plasmid Capture by the Bacillus thuringiensis Conjugative Plasmid pXO16▿

    Timmery, Sophie; Modrie, Pauline; Minet, Olivier; Mahillon, Jacques

    2009-01-01

    Conjugation, mobilization, and retromobilization are three related mechanisms of horizontal gene transfer in bacteria. They have been extensively studied in gram-negative species, where retromobilization, the capture of DNA from a recipient by a donor cell, was shown to result from two successive steps: the transfer of the conjugative plasmid from the donor to the recipient followed by the retrotransfer of the mobilizable plasmid to the donor. This successive model was established for gram-ne...

  20. Conjugative plasmids: Vessels of the communal gene pool

    Norman, Anders; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    over large taxonomic distances. These plasmids are collections of discrete regions of genes that function as ‘backbone modules' to undertake different aspects of overall plasmid maintenance and propagation. Conjugative plasmids often carry suites of ‘accessory elements' that contribute adaptive traits...

  1. Compositional discordance between prokaryotic plasmids and host chromosomes

    van Kampen Antoine HC

    2006-02-01

    Full Text Available Abstract Background Most plasmids depend on the host replication machinery and possess partitioning genes. These properties confine plasmids to a limited range of hosts, yielding a close and presumably stable relationship between plasmid and host. Hence, it is anticipated that due to amelioration the dinucleotide composition of plasmids is similar to that of the genome of their hosts. However, plasmids are also thought to play a major role in horizontal gene transfer and thus are frequently exchanged between hosts, suggesting dinucleotide composition dissimilarity between plasmid and host genome. We compared the dinucleotide composition of a large collection of plasmids with that of their host genomes to shed more light on this enigma. Results The dinucleotide frequency, coined the genome signature, facilitates the identification of putative horizontally transferred DNA in complete genome sequences, since it was found to be typical for a certain genome, and similar between related species. By comparison of the genome signature of 230 plasmid sequences with that of the genome of each respective host, we found that in general the genome signature of plasmids is dissimilar from that of their host genome. Conclusion Our results show that the genome signature of plasmids does not resemble that of their host genome. This indicates either absence of amelioration or a less stable relationship between plasmids and their host. We propose an indiscriminate lifestyle for plasmids preserving the genome signature discordance between these episomes and host chromosomes.

  2. Competition between Plasmid-Bearing and Plasmid-Free Organisms in a Chemostat with Pulsed Input and Washout

    Sanling Yuan; Yu Zhao; Anfeng Xiao

    2009-01-01

    We consider a model of competition between plasmid-bearing and plasmid-free organisms in the chemostat with pulsed input and washout. We investigate the subsystem with nutrient and plasmid-free organism and study the stability of the boundary periodic solutions, which are the boundary periodic solutions of the system. The stability analysis of the boundary periodic solution yields the invasion threshold of the plasmid-bearing organism. By using the standard techniques of bifurcation theory, w...

  3. Co-segregation of yeast plasmid sisters under monopolin-directed mitosis suggests association of plasmid sisters with sister chromatids

    Liu, Yen-Ting; Ma, Chien-Hui; Jayaram, Makkuni

    2013-01-01

    The 2-micron plasmid, a high copy extrachromosomal element in Saccharomyces cerevisiae, propagates itself with nearly the same stability as the chromosomes of its host. Plasmid stability is conferred by a partitioning system consisting of the plasmid-coded proteins Rep1 and Rep2 and a cis-acting locus STB. Circumstantial evidence suggests that the partitioning system couples plasmid segregation to chromosome segregation during mitosis. However, the coupling mechanism has not been elucidated. ...

  4. The Residence Life Cinema.

    Dungan, Jane Fidler; Elion, Audrey; Gusmano, Phil

    1997-01-01

    Explores the implementation, results, and the limitations of the Residence Life Cinema program at the University of Memphis. Claims that such programs offer an innovative method for fostering student development by utilizing movies to stimulate affective and cognitive processes in students--processes that may not occur without a catalyst. (RJM)

  5. A comparison of the modern seismogenic Nankai mega-splay fault and the exhumed ancient mega-splay fault, the Nobeoka thrust

    Kimura, G.; Hamahashi, M.; Yamaguchi, A.; Saito, S.; Fukuchi, R.; Kameda, J.; Hamada, Y.; Fujimoto, K.; Hashimoto, Y.; Hina, S.; Eida, M.; Kitamura, Y.

    2012-12-01

    Mega-splay fault branched from plate boundary megathrust in subduction zone is located around the border between outer and inner wedges and is considered to cause great earthquake and tsunami such as 1960 Alaska earthquake, 1944 and 1946 Nankai-Tonankai earthquakes, and 2004 Sumatra earthquakes. Therefore, understanding the fault mechanics of the mega-splay fault is essential toward assessing their role in the plate boundary processes and seismo-tsunamigenesis. Seismic reflection studies for the mega-splay fault in 2D and 3D in the Nankai forearc present the reflector with negative or positive polarities with various amplitudes and suggest complicated petrophysical properties and condition of the fault and its surroundings. The Nankai mega-splay fault at a depth of ~5km is going to be drilled and cored by Integrated Ocean Drilling Program, NantroSEIZE experiments and is expected for great progress of understanding of the fault mechanics. Deep portion of the megasplay fault and its connection to the plate boundary megathrust is, however, impossible to be accessed by direct drilling. Far and near field geophysical observation is therefore only way to access the modern and active megasplay fault. On-land exhumed and fossilized mega-splay faults, on the other hand, give a clue for the fault mechanics when they were active in depth although the exhumation and fossilization process modifies their primary properties due to physico-chemical weathering and crack opening by unloading. Our previous studies from the Nobeoka thrust in Kyushu, southwest Japan present well-preservation of primary faulting processes and clear contrast of physical property between the hanging wall and footwall. We have conducted the seismic, drilling, coring and logging investigation into the Nobeoka thrust to the depth of ~250 m including ~40m hanging wall and ~210 m footwall. The coring was ~99% recovery and full logging was successful. The result of the logging together with triangular S

  6. THE INTEGRATED STATE OF THE ROLLING-CIRCLE PLASMID PTB913 IN THE COMPOSITE BACILLUS PLASMID PTB19

    OSKAM, L; HILLENGA, DJ; VENEMA, G; BRON, S

    1992-01-01

    pTB19, a 27 kb plasmid originating from a thermophilic Bacillus species, contains integrated copies of two rolling-circle type plasmids on a 10.6 kb DNA fragment. In the present study we analysed the part of pTB19 that contains the rolling-circle plasmid pTB913 and the region in between the two roll

  7. Of Mega-Malls and Soft-Shelled Turtles: Deep Ecological Education To Counter Homogeneity.

    Quinn, Michael S.; Scott, Jennifer R.

    1997-01-01

    Attempts to compare the modern retail/entertainment experience of the mega-mall to a singular encounter with a wild animal in its native community context. Explores the differences between seeking amusement and seeking happiness as well as the capacity for experiencing joy. Concludes with some implications of these experiences to the…

  8. Building the MEGA Image-Subtraction Pipeline in the Era of Virtual Observatories

    Alves, D R; Bergier, A; Cseresnjes, P; Gersch, A; Alves, David R.

    2003-01-01

    We are inventing techniques to increase variable source yields from image subtraction analyses. An example innovation that will improve detection efficiency by about 10% is presented. The MEGA image-subtraction pipeline is a software instrument that could evolve into a tool to do microlensing science with virtual observatories.

  9. Unemployment, Entrepreneurial Education and Mega Universities: Challenges to Expanding Access in Education in Nigeria University

    Undie, John Atewhoble; Okafor, Victor

    2014-01-01

    In fundamental economics, individuals acquired education for two broad reasons, as an investment and as consumption. The investment function of education has continued to create tension for job search leading to cases of unemployment. Entrepreneurship education and establishment of mega universities have been identified as panaceas. This paper…

  10. The economic performance of supply chain(s) served by the mega freight transport vehicles

    Janic, M.

    2014-01-01

    This paper deals with the economic performances of supply chain(s) served by different including the mega freight transport vehicles. These performances are considered as a dimension of the supply chain’s sustainability together with the infrastructural, technical/technological, operational, environ

  11. (Mega)structures: Structural Imagination and New Spatial Visions, 1945- 1970

    Pizza de Nanno, Antonio

    2012-01-01

    Reseña 2: Symposium. *(Mega)structures: Structural Imagination and New Spatial Visions, 1945- 1970: recorridos a partir del atlas mnemosyne. Seminario Internacional dirigido por Alessandro De Magistris, Federico Deambrosis y Antonio Pizza. Dipartimento di Architettura e Pianificazione Politecnico di Milano, 22-23 novembre 2011.

  12. Facilitators and Inhibitors of Bidding and Hosting Mega Sporting Events in Iran

    Mohammad Koosha

    2013-01-01

    Full Text Available Legacies of hosting mega sporting events have been attempting idea for both the developed and the developing nations to participate in "bidding" competitions. Through mega sporting events bid process, despite all defined essentials infrastructures, the viewpoint of local organizing committee play a significant role to propose a winning bid and delivery of successful games. This research aims to identify the facilitators and inhibitors of bidding and hosting mega sporting events in Iran from the viewpoints of the Iranian distinguished professors in the sport management and the sport executive managers. Researcher questionnaire and Semi-structure interviews were conducted to gain in depth data. The results indicated that Iran currently has limitations to have winning bid and successful host mega sporting events; even though, it possesses the potential to do so. Public interest and support for hosting the sport events, good security condition against terrorism and tourist attractions are known as the strong points and he challenges and inhibitors which Iran is faced with includes: the qualitative and quantitative weakness in the transportation infrastructures and sport venues, west countries economic boycott, unstable government support and the lack of long-run planning for the events.

  13. OER on the Asian Mega Universities: Developments, Motives, Openness, and Sustainability

    Farisi, Mohammad Imam

    2013-01-01

    The OER movement originated and integrated into ODE developments. Mega Universities (MUs) are among the most important of ODE providers worldwide should be to be the primary organizations for providing access to OER. So far, however, in-depth studies on OER developments in the Asian MUs were very limited. This study focuses on the developments,…

  14. A Mega-project on Space Weather Monitoring Gets the Green Light

    2005-01-01

    @@ A 200-million-yuan ($25 million) mega-project of science research on space weather monitoring, namely the Meridian Space Weather Moni toting Project (Meridian Project for short), proposed by several research institutes and universities in China has been approved recently by the Chinese government.

  15. The bidding paradox: why rational politicians still want to bid for mega sports events

    de Nooij, M.; van den Berg, M.R.

    2013-01-01

    This paper discusses reasons why politicians still favor hosting mega events despite the discouraging evidence regarding their financial benefits: (1) early political enthusiasm, (2) tying side-projects to the bid to raise political support, (3) biased reading of history, (4) the winners curse, (5)

  16. Identify the costs and benefits of bidding for the hosting of a mega-event

    熊淑一

    2014-01-01

    A mega-event which attracts attention from all over the world might have both positive and negative effect on the hosting city (Syme et al.1989).The aim of this paper is to evaluate the costs and benefits of bidding for the hosting of mega-events.It identified legacies of bidding for the hosting of mega-events from following four aspects,which are economics,public life,infrastructure,and image of the hosting city,with the methods of literature review,logic analysis,examples,and contrast analysis.The result of this study unveiled that when a city bids for hosting a mega-event for the purpose of stimulating its local economic,improving civic pride,developing basic public infrastructures,and enhance its city image to the worldwide,it also needs to pay attention to potential drawbacks of hosting the event,such as debt crisis,interfering the daily life of the public.

  17. (Mega)structures: Structural Imagination and New Spatial Visions, 1945- 1970

    Pizza de Nanno, Antonio

    2012-01-01

    Reseña 2: Symposium. *(Mega)structures: Structural Imagination and New Spatial Visions, 1945- 1970: recorridos a partir del atlas mnemosyne. Seminario Internacional dirigido por Alessandro De Magistris, Federico Deambrosis y Antonio Pizza. Dipartimento di Architettura e Pianificazione Politecnico di Milano, 22-23 novembre 2011. Peer Reviewed

  18. Mega-event strategy as a tool of urban transformation: Sydney's experience

    Chen, Y.; Spaans, M.

    2009-01-01

    Mega-event strategies and their impact on host cities have drawn increasing interest, as organising large-scale urban events has become part of a deliberate urban policy strategy to promote local economic growth and put the host city on the world agenda. Thus far, the research addressing what strate

  19. Mega Events and Urban Conflicts in Valencia, Spain: Contesting the New Urban Modernity

    Luis del Romero Renau

    2011-01-01

    Full Text Available The local and regional administrations of Valencia, Spain, have been working to position the city, which is the country's third largest in terms of population, as an international destination for luxury tourism through sports mega-events. Valencia's new image as a “mega-events city” has been criticized by citizens and urban-based movements on social and environmental grounds, resulting in various urban conflicts. The aim of this paper is to examine the causes and dynamics of these conflicts in order to understand the discourse and rationales behind the criticism. This will also include an examination of the ways in which these conflicts were managed by the local administration, especially in the months leading up to and during the events, when the city was receiving worldwide media coverage. Researching local print media, we focused on urban conflicts that took place in Valencia between 1995 and 2010. We also looked at the performance of urban-based movements and the administration as conflicting actors. One of the main findings was the strong consensual authoritarianism manifested by the administration and mega-event organizers when making decisions and managing urban conflicts related to mega-events.

  20. Stable inheritance of plasmid R1 requires two different loci.

    Gerdes, K; Larsen, J E; Molin, S

    1985-01-01

    The largest EcoRI fragment from plasmid R1 mediates a stability phenotype which is required to ensure the stable inheritance of this low-copy-number plasmid. When covalently linked to small, unstable R1 derivatives, this fragment makes the plasmids as stable as the wild-type R1 plasmid. A genetic analysis showed that two independently acting stabilization functions are encoded by this EcoRI fragment, both of which have the potential of partial stabilization of mini-R1 plasmids. The two loci a...

  1. DNA restriction-modification systems mediate plasmid maintenance.

    Kulakauskas, S; Lubys, A; Ehrlich, S. D.

    1995-01-01

    Two plasmid-carried restriction-modification (R-M) systems, EcoRI (from pMB1 of Escherichia coli) and Bsp6I (from pXH13 of Bacillus sp. strain RFL6), enhance plasmid segregational stability in E. coli and Bacillus subtilis, respectively. Inactivation of the endonuclease or the presence of the methylase in trans abolish the stabilizing activity of the R-M systems. We propose that R-M systems mediate plasmid segregational stability by postsegregational killing of plasmid-free cells. Plasmid-enc...

  2. Non-climatic signal in ice core records: lessons from Antarctic mega-dunes

    Ekaykin, A.; Eberlein, L.; Lipenkov, V.; Popov, S.; Scheinert, M.; Schröder, L.; Turkeev, A.

    2015-12-01

    We present the results of glaciological investigations in the mega-dune area located 30 km to the east from Vostok Station (central East Antarctica) implemented during the 58th, 59th and 60th Russian Antarctic Expedition (January 2013-January 2015). Snow accumulation rate and isotope content (δD, δ18O and δ17O) were measured along the 2 km profile across the mega-dune ridge accompanied by precise GPS altitude measurements and GPR survey. It is shown that the spatial variability of snow accumulation and isotope content covaries with the surface slope. The accumulation rate regularly changes by one order of magnitude within the distance < 1 km, with the reduced accumulation at the leeward slope of the dune and increased accumulation in the hollow between the dunes. At the same time, the accumulation rate averaged over the length of a dune wave (22 mm we) corresponds well with the value obtained at Vostok Station, which suggests no additional wind-driven snow sublimation in the mega-dunes compared to the surrounding plateau. The snow isotopic composition is in negative correlation with the snow accumulation. Analyzing dxs/δD and 17O-excess/δD slopes, we conclude that the spatial variability of the snow isotopic composition in the mega-dune area could be explained by post-depositional snow modifications. Using the GPR data, we estimated the apparent dune drift velocity (4.6 ± 1.1 m yr-1). The full cycle of the dune drift is thus about 410 years. Since the spatial anomalies of snow accumulation and isotopic composition are supposed to drift with the dune, an ice core drilled in the mega-dune area would exhibit the non-climatic 410 year cycle of these two parameters. We simulated a vertical profile of snow isotopic composition with such a non-climatic variability, using the data on the dune size and velocity. This artificial profile is then compared with the real vertical profile of snow isotopic composition obtained from a core drilled in the mega-dune area. We

  3. Radar scattering of linear dunes and mega-yardangs: Application to Titan

    Paillou, Philippe; Seignovert, Benoît; Radebaugh, Jani; Wall, Stephen

    2016-05-01

    The Ku-band (13.8 GHz - 2.2 cm) RADAR instrument onboard the Cassini-Huygens spacecraft has revealed the richness of the surface of Titan, as numerous seas, lakes, rivers, cryo-volcanic flows and vast dune fields have been discovered. Linear dunes are a major geomorphological feature present on Titan, covering up to 17% of its surface, mainly in equatorial regions. However, the resolution of the RADAR instrument is not good enough to allow a detailed study of the morphology of these features. In addition, other linear wind-related landforms, such as mega-yardangs (linear wind-abraded ridges formed in cohesive rocks), are likely to present a comparable radar signature that could be confused with the one of dunes. We conducted a comparative study of the radar radiometry of both linear dunes and mega-yardangs, based on representative terrestrial analogues: the linear dunes located in the Great Sand Sea in western Egypt and in the Namib Desert in Namibia, and the mega-yardangs observed in the Lut Desert in eastern Iran and in the Borkou Desert in northern Chad. We analysed the radar scattering of both terrestrial linear dunes and mega-yardangs, using high-resolution radar images acquired by the X-band (9.6 GHz - 3.1 cm) sensor of the TerraSAR-X satellite. Variations seen in the radar response of dunes are the result of a contrast between the dune and interdune scattering, while for mega-yardangs these variations are the result of a contrast between ridges and erosion valleys. We tested a simple surface scattering model, with parameters derived from the local topography and surface roughness estimates, to accurately reproduce the radar signal variations for both landforms. It appears that we can discriminate between two types of dunes - bare interdunes as in Egypt and sand-covered interdunes as in Namibia, and between two types of mega-yardangs - young yardangs as in Iran and older ones as in Chad. We applied our understanding of the radar scattering to the analysis of

  4. Interdecadal variability of the mega-ENSO-NAO synchronization in winter

    Wu, Zhiwei; Zhang, Peng

    2015-08-01

    Mega-El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO), as two principal components of the global air-sea coupling system, may have synchronous or out-synchronous fluctuations during different epochs. Understanding such connection change is instrumental for climate prediction, particularly the decadal prediction. Results in this study show that mega-ENSO has experienced a notable inter-decadal change in its linkage with the winter NAO during the past 56 years: mega-ENSO was significantly correlated with the NAO during 1957-1981 (or synchronous epoch), while such correlation has broken down since 1982 (or out-synchronous epoch). This marked change might be attributed to a sea surface temperature (SST) forcing change in the North Atlantic, based on the observational and numerical evidences in this study. The synchronous epoch is concurrent with the anomalous tropical North Atlantic (TNA) SST forcing, whereas the out-synchronous epoch is associated with the anomalous extra-tropical North Atlantic (XNA) SST forcing. Two possible reasons may explain how the synchronous behaviors between mega-ENSO and the NAO were tied to the TNA SST anomaly (SSTA). There is a positive feedback between the TNA SSTA and the NAO-like atmosphere anomalies, which helps to "prolong" the NAO impacts from the developing phase through mature phase of mega-ENSO. Additionally, the TNA SSTA itself may induce a NAO-like atmosphere anomaly. Since 1982, the TNA SSTA has been replaced by the XNA SSTA and the latter primarily favors a NAO-neutral state in the atmosphere, which ends the synchronous epoch.

  5. Role of Plasmid in Production of Acetobacter Xylinum Biofilms

    Abbas Rezaee

    2005-01-01

    Full Text Available Acetobacter xylinum has the ability to produce cellulotic biofilms. Bacterial cellulose is expected to be used in many industrial or biomedical materials for its unique characteristics. A. xylinum contains a complex system of plasmid DNA molecules. A 44 kilobases (kb plasmid was isolated in wild type of A. xylinum. To improve the cellulose producing ability of A. xylinum, role of the plasmid in production of cellulose was studied. The comparisons between wild type and cured cells of A. xylinum showed that there is considerably difference in cellulose production. In order to study the relationship between plasmid and the rate of cellulose production, bacteria were screened for plasmid profile by a modified method for preparation of plasmid. This method yields high levels of pure plasmid DNA that can be used for common molecular techniques, such as digestion and transformation, with high efficiency.

  6. Deficient sumoylation of yeast 2-micron plasmid proteins Rep1 and Rep2 associated with their loss from the plasmid-partitioning locus and impaired plasmid inheritance.

    Jordan B Pinder

    Full Text Available The 2-micron plasmid of the budding yeast Saccharomyces cerevisiae encodes copy-number amplification and partitioning systems that enable the plasmid to persist despite conferring no advantage to its host. Plasmid partitioning requires interaction of the plasmid Rep1 and Rep2 proteins with each other and with the plasmid-partitioning locus STB. Here we demonstrate that Rep1 stability is reduced in the absence of Rep2, and that both Rep proteins are sumoylated. Lysine-to-arginine substitutions in Rep1 and Rep2 that inhibited their sumoylation perturbed plasmid inheritance without affecting Rep protein stability or two-hybrid interaction between Rep1 and Rep2. One-hybrid and chromatin immunoprecipitation assays revealed that Rep1 was required for efficient retention of Rep2 at STB and that sumoylation-deficient mutants of Rep1 and Rep2 were impaired for association with STB. The normal co-localization of both Rep proteins with the punctate nuclear plasmid foci was also lost when Rep1 was sumoylation-deficient. The correlation of Rep protein sumoylation status with plasmid-partitioning locus association suggests a theme common to eukaryotic chromosome segregation proteins, sumoylated forms of which are found enriched at centromeres, and between the yeast 2-micron plasmid and viral episomes that depend on sumoylation of their maintenance proteins for persistence in their hosts.

  7. Modeling sRNA-regulated Plasmid Maintenance

    Gong, Chen Chris

    2016-01-01

    We study a theoretical model for the toxin-antitoxin (hok/sok) mechanism for plasmid maintenance in bacteria. Toxin-antitoxin systems enforce the maintenance of a plasmid through post-segregational killing of cells that have lost the plasmid. Key to their function is the tight regulation of expression of a protein toxin by an sRNA antitoxin. Here, we focus on the nonlinear nature of the regulatory circuit dynamics of the toxin-antitoxin mechanism. The mechanism relies on a transient increase in protein concentration rather than on the steady state of the genetic circuit. Through a systematic analysis of the parameter dependence of this transient increase, we confirm some known design features of this system and identify new ones: for an efficient toxin-antitoxin mechanism, the synthesis rate of the toxin's mRNA template should be lower that of the sRNA antitoxin, the mRNA template should be more stable than the sRNA antitoxin, and the mRNA-sRNA complex should be more stable than the sRNA antitoxin. Moreover, ...

  8. Mega starbirth cluster is biggest, brightest and hottest ever seen

    2003-10-01

    -European Coordinating Facility in Germany, and a team of international co-authors report the discovery in the 20 October 2003 issue of the Astrophysical Journal. The mega-cluster of stars appears as a puzzling red arc behind a distant galaxy cluster 5400 million light-years away in the northern constellation of Lynx. The arc is the stretched and magnified image of a mysterious celestial object about 12 000 million light-years away (at a redshift of 3.36), far beyond the cluster of galaxies. This means that the remote source existed when the Universe was less than 2000 million years old. Fosbury and colleagues first tried to identify the arc by analysing the light from the object, but the team was not able to recognise the pattern of colours in the spectral signature of the remote object. While looking for matches with the colour spectrum, Fosbury realised that the light was related to that of the nearby Orion Nebula, a star-forming region in our own Milky Way. However where the Orion Nebula is powered by only four hot and bright blue stars, the Lynx Arc must contain around a million such stars! Furthermore, the spectrum shows that the stars in the Lynx Arc are more than twice as hot as the Orion Nebula's central stars, with surface temperatures up to 80 000°C. Though there are much bigger and brighter star-forming regions than the Orion Nebula in our local Universe, none are as bright as the Lynx Arc, nor do they contain such large numbers of hot stars. Even the most massive, normal nearby stars are no hotter than around 40 000°C. However, stars forming from the original, pristine gas in the early Universe can be more massive and consequently much hotter - perhaps up to 120 000°C. The earliest stars may have been as much as several hundred solar masses, but the chemical make-up of the Universe today prevents stars from forming beyond about 100 solar masses. Such 'primordial' super-hot stars are thought to be the first luminous objects to condense after the Big Bang cooled

  9. Lawful Permanent Residents - Annual Report

    Department of Homeland Security — A lawful permanent resident (LPR) or 'green card' recipient is defined by immigration law as a person who has been granted lawful permanent residence in the United...

  10. Determination of Plasmid Segregational Stability in a Growing Bacterial Population.

    Kramer, M Gabriela

    2016-01-01

    Bacterial plasmids are extensively used as cloning vectors for a number of genes for academic and commercial purposes. Moreover, attenuated bacteria carrying recombinant plasmids expressing genes with anti-tumor activity have shown promising therapeutic results in animal models of cancer. Equitable plasmid distribution between daughter cells during cell division, i.e., plasmid segregational stability, depends on many factors, including the plasmid copy number, its replication mechanism, the levels of recombinant gene expression, the type of bacterial host, and the metabolic burden associated with all these factors. Plasmid vectors usually code for antibiotic-resistant functions, and, in order to enrich the culture with bacteria containing plasmids, antibiotic selective pressure is commonly used to eliminate plasmid-free segregants from the growing population. However, administration of antibiotics can be inconvenient for many industrial and therapeutic applications. Extensive ongoing research is being carried out to develop stably-inherited plasmid vectors. Here, I present an easy and precise method for determining the kinetics of plasmid loss or maintenance for every ten generations of bacterial growth in culture. PMID:26846807

  11. Plasmid transfer between bacteria in soil microcosms and the field

    Eric Smit

    1997-01-01

    Full Text Available In ibis review factors influencing conjugal plasmid transfer between bacteria and the possible role of naturally occurring selftransmissible plasmide for the dissemination of recombinant DNA in soil will be discussed. In microcosm studies, plasmid transfer between various species of introduced bacteria has been detected. Moreover, plamid transfer to indigenous soil micoorganisms was observed. Soil is an oligotrophic environment and plasmid transfer occurred mainly under conditions which were nutritionally favourable for bacteria, such as in the plant rhizosphere and in the presence of clay minerais or added nutrients. Mobilizable plasmids, lacking the ability to transfer themselves, have been reported to be transferred in the presence of selftransmissible plasmids. A study comparing conjugal transfer in microcosme with those in the field revealed that the transfer rates found in microcosme and in the field were similar. Transfer of chromosomal DNA by plasmid RP4 could only be shown on filters and was not observed in soil. Transfer of plasmids carrying biodegradative genes appeared to be favoured in the presence of the compound that can be degraded. Evidence was found for the presence of naturally-occurring selftransmissible plasmids in bacteria in the rhizosphere which could mobilize recombinant plasmids.

  12. Characterization of toxin plasmids in Clostridium perfringens type C isolates.

    Gurjar, Abhijit; Li, Jihong; McClane, Bruce A

    2010-11-01

    Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin and beta toxin but often produce additional toxins, e.g., beta2 toxin or enterotoxin. Since plasmid carriage of toxin-encoding genes has not been systematically investigated for type C isolates, the current study used Southern blot hybridization of pulsed-field gels to test whether several toxin genes are plasmid borne among a collection of type C isolates. Those analyses revealed that the surveyed type C isolates carry their beta toxin-encoding gene (cpb) on plasmids ranging in size from ∼65 to ∼110 kb. When present in these type C isolates, the beta2 toxin gene localized to plasmids distinct from the cpb plasmid. However, some enterotoxin-positive type C isolates appeared to carry their enterotoxin-encoding cpe gene on a cpb plasmid. The tpeL gene encoding the large clostridial cytotoxin was localized to the cpb plasmids of some cpe-negative type C isolates. The cpb plasmids in most surveyed isolates were found to carry both IS1151 sequences and the tcp genes, which can mediate conjugative C. perfringens plasmid transfer. A dcm gene, which is often present near C. perfringens plasmid-borne toxin genes, was identified upstream of the cpb gene in many type C isolates. Overlapping PCR analyses suggested that the toxin-encoding plasmids of the surveyed type C isolates differ from the cpe plasmids of type A isolates. These findings provide new insight into plasmids of proven or potential importance for type C virulence. PMID:20823204

  13. Design of Hollow Reinforced Concrete Columns in the Tubed Mega Frame : Dimensionering av ihåliga armerade betongpelare i ”Tubed Mega Frame”

    Tönseth, David; Welchermill, Kristian

    2014-01-01

    A new concept for the structural system for tall buildings, called the “Tubed Mega Frame”, has been developed by Tyréns AB. The structure consists of several hollow reinforced concrete columns at the perimeter of the building and at certain levels, the columns are tied together with perimeter walls. Together they carry all the vertical and lateral loads. A purpose of the new concept is to eliminate the core in the center of the building which allows utilizing more floor spacing compared with...

  14. Challenges to publishing pharmacy resident research projects from the perspectives of residency program directors and residents

    Olson KL

    2013-09-01

    Full Text Available Objective: To identify barriers to completing and publishing pharmacy residency research projects from the perspective of program directors and former residents.Methods: This was a cross-sectional survey of pharmacy residency program directors and former post-graduate year one and two residents. Directors of pharmacy residency programs whose residents present their projects at the Western States Conference (n=216 were invited to complete an online survey and asked to forward the survey to former residents of their program in 2009, 2010, or 2011. The survey focused on four broad areas: 1 demographic characteristics of the residency programs, directors, and residents; 2 perceived value of the research project; 3 perceived barriers with various stages of research; and 4 self-identified barriers to successful research project completion and publication.Results: A total of 32 program directors and 98 residents completed the survey. The minority of programs offered formal residency research training. Both groups reported value in the research project as part of residency training. Significantly more directors reported obtaining institutional review board approval and working through the publication process as barriers to the research project (46.7% vs. 22.6% and 73.3% vs. 43.0%, respectively p<0.05 while residents were more likely to report collecting and analyzing the data as barriers (34.4% vs. 13.3% and 39.8% vs. 20.0%, respectively, p<0.05. Both groups self-identified time constraints and limitations in study design or quality of the study as barriers. However, while program directors also indicated lack of resident motivation (65.5%, residents reported lack of mentorship or program structural issues (43.3%. Conclusion: Overall, while both groups found value in the residency research projects, there were barriers identified by both groups. The results of this study may provide areas of opportunity for improving the quality and publication rates of

  15. Evolving seismogenic plate boundary megathrust and mega-splay faults in subduction zone (Invited)

    Kimura, G.; Hamahashi, M.; Fukuchi, R.; Yamaguchi, A.; Kameda, J.; Kitamura, Y.; Hashimoto, Y.; Hamada, Y.; Saito, S.; Kawasaki, R.

    2013-12-01

    Understanding the fault mechanism and its relationship to the sesimo-tsunamigenesis is a key of the scientific targets of subduction zone and therefore NantroSEIZE project of IODP and future new drilling project of International Ocean Discovery Program keeps focusing on that. Mega-splay fault branched from plate boundary megathrust in subduction zone is located around the border between outer and inner wedges and is considered to cause great earthquake and tsunami such as 1960 Alaska earthquake, 1944 and 1946 Nankai-Tonankai earthquakes, and 2004 Sumatra earthquakes. Seismic reflection studies for the mega-splay fault in 2D and 3D in the Nankai forearc present the reflector with negative or positive polarities with various amplitudes and suggest complicated petrophysical properties and condition of the fault and its surroundings. The Nankai mega-splay fault at a depth of ~5km is going to be drilled and cored by NantroSEIZE experiments and is expected for great progress of understanding of the fault mechanics. Before drilling the really targeted seismogenic fault, we are conducting many exercises of geophysical and geological observations. The core-log-seismic integrated exercise for the exhumed mega-splay fault by drilling was operated for the Nobeoka thrust in the Shimanto Belt, Kyushu, Japan. The Nobeoka thrust was once buried in the depth >~10km and suffered maximum temperature >~300 dgree C. As the core recovery is ~99%, perfect correlation between the core and logging data is possible. Thickness of the fault zone is >200 m with a ~50 cm thick central fault core dividing the phyllitic hanging wall and the footwall of broken-melange like cataclasite. A-few-meter-thick discrete damage zones with fault cores are recognized by difference in physical properties and visual deformation textures at several horizons in the fault zone. Host rocks for those damaged zones are completely lithified cataclasites with abundant mineral veins, which record the older and deeper

  16. pB264, a small, mobilizable, temperature sensitive plasmid from Rhodococcus

    Currie Devin H

    2004-04-01

    Full Text Available Abstract Background Gram-positive bacteria of the genus Rhodococcus have shown an extraordinary capacity for metabolizing recalcitrant organic compounds. One hindrance to the full exploitation of Rhodococcus is the dearth of genetic tools available for strain manipulation. To address this issue, we sought to develop a plasmid-based system for genetic manipulation of a variety of Rhodococcus strains. Results We isolated and sequenced pB264, a 4,970 bp cryptic plasmid from Rhodococcus sp. B264-1 with features of a theta-type replication mechanism. pB264 was nearly identical to pKA22, a previously sequenced but uncharacterized cryptic plasmid. Derivatives of pB264 replicate in a diverse range of Rhodococcus species, showing that this plasmid does not bear the same host range restrictions that have been exhibited by other theta replicating plasmids. Replication or maintenance of pB264 is inhibited at 37°C, making pB264 useful as a suicide vector for genetic manipulation of Rhodococcus. A series of deletions revealed that ca. 1.3 kb from pB264 was sufficient to support replication and stable inheritance of the plasmid. This region includes two open reading frames that encode functions (RepAB that can support replication of pB264 derivatives in trans. Rhodococcus sp. B264-1 will mobilize pB264 into other Rhodococcus species via conjugation, making it possible to genetically modify bacterial strains that are otherwise difficult to transform. The cis-acting element (oriT required for conjugal transfer of pB264 resides within a ca. 0.7 kb region that is distinct from the regions responsible for replication. Conclusion Shuttle vectors derived from pB264 will be useful for genetic studies and strain improvement in Rhodococcus, and will also be useful for studying the processes of theta replication and conjugal transfer among actinomycetes.

  17. Unique type of plasmid maintenance function: postsegregational killing of plasmid-free cells.

    Gerdes, K; Rasmussen, P. B.; Molin, S

    1986-01-01

    The stability locus parB+ of plasmid R1 has been found to specify a unique type of plasmid maintenance function. Two genes, hok (host killing) and sok (suppressor of killing), are required for the stabilizing activity. The hok gene encodes a highly toxic gene product, whose overexpression causes a rapid killing and a concomitant dramatic change in morphology of the host cell. The other gene, sok, was found to encode a product that counteracts the hok gene-mediated killing. The parB+ region wa...

  18. Molecular characterization of "plasmid-free" antibiotic-resistant Haemophilus influenzae.

    Roberts, M C; Smith, A. L.

    1980-01-01

    We examined 14 multiresistant and 8 ampicillin- or tetracycline-resistant Haemophilus influenzae isolates and 4 ampicillin-resistant H. parainfluenzae isolates for plasmid deoxyribonucleic acid. Sixteen strains carried plasmids. Both "plasmid-free" and plasmid-carrying isolates transferred the antibiotic resistance by conjugation. All transconjugants carried plasmid deoxyribonucleic acid, suggesting that the apparent plasmid-free strains contained R plasmids encoding for antibiotic resistance.

  19. Resident Peritoneal NK cells

    Gonzaga, Rosemary; Matzinger, Polly; Perez-Diez, Ainhoa

    2011-01-01

    Here we describe a new population of NK cells that reside in the normal, un-inflamed peritoneal cavity. Phenotypically, they share some similarities with the small population of CD49b negative, CD27 positive immature splenic NK cells, and liver NK cells but differ in their expression of CD62L, TRAIL and EOMES. Functionally, the peritoneal NK cells resemble the immature splenic NK cells in their production of IFN-γ, GM-CSF and TNF-α and in the killing of YAC-1 target cells. We also found that ...

  20. MegaFlex Scale-Up Cost & Risk Reduction for >50kW Future Power Demands Project

    National Aeronautics and Space Administration — As the MegaFlex solar array is scaled for power demands greater than 50kW over the next 20 years and deployed load requirements remain high or increase, advanced...

  1. Pengaruh Inovasi Dan Jiwa Kewirausahaan Terhadap Keberhasilan Usaha (Studi Kasus: Pelaku UMKM Kuliner Chinatown Asia Mega Mas Medan)

    Mawaddah, Nadia Inda

    2016-01-01

    This research was conducted to examine the effect of innovation and entrepreneurs Spirit to business success (Case Study: SMEs Of Kuliner Chinatown Asia Mega Mas Medan). The research was conducted on SMEs in the Asia Mega Mas with a total sample of 35 businesses. The sampling method used in this research was saturated sampling by using descriptive analysis method, statistical analysis method whis consist of double linear regression analysis, simultaneous significance test (F-test), partial si...

  2. Parallels in portraits of leadership in mega churches of Gauteng (RSA) and Florida (USA) / Tsietsi John Maloma

    Maloma, Tsietsi John

    2011-01-01

    This thesis, Parallels in portraits of leadership in mega churches of Gauteng (RSA) and Florida (USA), the researcher, studied literature on church leadership with special reference to the leadership of mega churches. He researched issues relating to the nature of church leadership by exploring relevant Bible passages, the lives of certain Bible characters that the Bible presents as good but not perfect leaders, as well as relevant key theological conceptions of leadership. The study accordin...

  3. Defining a quantitative framework for evaluation and optimisation of the environmental impacts of mega-event projects

    Parkes, O.; Lettieri, P.; Bogle, I. D.

    2016-01-01

    This paper presents a novel quantitative methodology for the evaluation and optimisation of the environmental impacts of the whole life cycle of a mega-event project: construction and staging the event and post-event site redevelopment and operation. Within the proposed framework, a mathematical model has been developed that takes into account greenhouse gas (GHG) emissions resulting from use of transportation fuel, energy, water and construction materials used at all stages of the mega-event...

  4. Nuclear background effects on plasma diagnostics for mega-joule class laser facility

    Estimating the vulnerability is a key challenge for plasma diagnostics designed to operate in radiative background associated with mega-joule class laser facilities. Since DT shots at OMEGA laser facility reproduce the perturbing source expected during the first 100 nanoseconds of a typical DT shot realized at National Ignition Facility (NIF) and Laser MegaJoule facility (LMJ), vulnerability of diagnostic elements such as optical relays or optical analyzers were experimentally studied and, if necessary, hardening approaches have been initiated to authorize their use at higher radiative constraints. Other facilities such as nuclear reactor or accelerator have been also used to estimate vulnerability issues as radiation induced emission of glasses or damage in multilayer coatings. (authors)

  5. Identify the costs and benefits of bidding for the hosting of a mega-event

    熊淑一

    2014-01-01

    A mega-event which attracts attention from all over the world might have both positive and negative effect on the hosting city(Syme et al.1989).The aim of this paper is to evaluate the costs and benefits of bidding for the hosting of megaevents.It identified legacies of bidding for the hosting of megaevents from following four aspects,which are economics,public life,infrastructure,and image of the hosting city,with the methods of literature review,logic analysis,examples,and contrast analysis.The result of this study unveiled that when a city bids for hosting a mega-event for the purpose of stimulating its local economic,improving civic pride,developing basic public infrastructures,and enhance its city image to the worldwide,it also needs to pay attention to potential drawbacks of hosting the event,such as debt crisis,interfering the daily life of the public.

  6. The Moses, mega-Moses, and Armstrong illusions: integrating language comprehension and semantic memory.

    Shafto, M; MacKay, D G

    2000-09-01

    This study develops a new theory of the Moses illusion, observed in responses to general knowledge questions such as, "How many animals of each kind did Moses take on the Ark?" People often respond "two" rather than "zero" despite knowing that Noah, not Moses, launched the Ark. Our theory predicted two additional types of conceptual error demonstrated here: the Armstrong and mega-Moses illusions. The Armstrong illusion involved questions resembling, "What was the famous line uttered by Louis Armstrong when he first set foot on the moon?" People usually comprehend such questions as valid, despite knowing that Louis Armstrong was a jazz musician who never visited the moon. This Armstrong illusion was not due to misperceiving the critical words (Louis Armstrong), and occurred as frequently as the Moses illusion (with critical words embedded in identical sentential contexts), but less frequently than the mega-Moses illusion caused when Moses and Armstrong factors were combined. PMID:11228907

  7. Safety and efficacy of DNA vaccines: Plasmids vs. minicircles

    Stenler, Sofia; Blomberg, Pontus; Smith, Ci Edvard

    2014-01-01

    While DNA vaccination using plasmid vectors is highly attractive, there is a need for further vector optimization regarding safety, stability, and efficiency. In this commentary, we review the minicircle vector (MC), which is an entity devoid of plasmid bacterial sequences, as an alternative to the traditional plasmid construct. The commentary highlights the recent discovery by Stenler et al. (2014) that the small size of an MC enables improved resistance to the shearing forces associated wit...

  8. Pathogenomics of the Virulence Plasmids of Escherichia coli

    Johnson, Timothy J.; Lisa K. Nolan

    2009-01-01

    Summary: Bacterial plasmids are self-replicating, extrachromosomal elements that are key agents of change in microbial populations. They promote the dissemination of a variety of traits, including virulence, enhanced fitness, resistance to antimicrobial agents, and metabolism of rare substances. Escherichia coli, perhaps the most studied of microorganisms, has been found to possess a variety of plasmid types. Included among these are plasmids associated with virulence. Several types of E. col...

  9. Identification of plasmid partition function in coryneform bacteria.

    Kurusu, Y; Satoh, Y.; Inui, M.; Kohama, K; Kobayashi, M.; Terasawa, M.; Yukawa, H

    1991-01-01

    We have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. ...

  10. Transformation of Bacillus thuringiensis protoplasts by plasmid deoxyribonucleic acid.

    Martin, P A; Lohr, J. R.; Dean, D H

    1981-01-01

    A method has been developed to transform plasmid deoxyribonucleic acid into protoplasts of the insect pathogen Bacillus thuringiensis. Protoplasts were formed by treatment of cells with lysozyme. The efficiency of formation of protoplasts was affected by the strain, the media, and the cell density. Deoxyribonucleic acid uptake was induced by polyethylene glycol. Deoxyribonucleic acid from the Staphylococcus aureus plasmid pC194 was used for transformation. Although this plasmid could not be i...

  11. Streamlined Purification of Plasmid DNA From Prokaryotic Cultures

    Pueschel, Laura; Li, Hongshan; Hymes, Matthew

    2011-01-01

    We describe the complete process of AcroPrep Advance Filter Plates for 96 plasmid preparations, starting from prokaryotic culture and ending with high purity DNA. Based on multi-well filtration for bacterial lysate clearance and DNA purification, this method creates a streamlined process for plasmid preparation. Filter plates containing silica-based media can easily be processed by vacuum filtration or centrifuge to yield appreciable quantities of plasmid DNA. Quantitative analyses determine ...

  12. Comparative genetic organization of incompatibility group P degradative plasmids.

    Burlage, R S; Bemis, L A; Layton, A C; Sayler, G. S.; Larimer, F

    1990-01-01

    Plasmids that encode genes for the degradation of recalcitrant compounds are often examined only for characteristics of the degradative pathways and ignore regions that are necessary for plasmid replication, incompatibility, and conjugation. If these characteristics were known, then the mobility of the catabolic genes between species could be predicted and different catabolic pathways might be combined to alter substrate range. Two catabolic plasmids, pSS50 and pSS60, isolated from chlorobiph...

  13. Computer Arithmetic Algorithms for Mega-Digit Floating Point Numbers' Precision

    Musbah J. Aqel; Mohammed H. Saleh

    2007-01-01

    IEEE standard 754 floating point is the most common representation used for floating point numbers, and many computer arithmetic algorithms are developed for basic operations on this standard. In this study, new computer algorithms are proposed to increase the precision range and to solve some problems that are available while using these algorithms. However, these algorithms provide an optional range of required accuracy (Mega-Digit precision) to meet new computer's applications.

  14. OER ON THE ASIAN MEGA UNIVERSITIES: DEVELOPMENTS, MOTIVES, OPENNESS, AND SUSTAINABILITY

    Mohammad Imam FARISI,

    2013-01-01

    The OER movement originated and integrated into ODE developments. Mega Universities (MUs) are among the most important of ODE providers worldwide should be to be the primary organizations for providing access to OER. So far, however, in-depth studies on OER developments in the Asian MUs were very limited. This study focuses on the developments, motives, openness, and sustainability of OER at the six MUs official websites in Asia. Data were collected for six months using the documentation tech...

  15. Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt.

    MacLellan, D.A.; Carroll, D.C.; Gray, R J; Booth, N.; Burza, Matthias; Desjarlais, M. P.; Du, F.; Neely, D; Powell, H. W.; Robinson, A. P. L.; Scott, G. G.; Yuan, X.H.; Wahlström, Claes-Göran; McKenna, P

    2014-01-01

    The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, a...

  16. Multi-dimensional project management models for mega-construction companies and their applications

    2011-01-01

    China is undertaking an increasing number of mega-infrastructure projects along with its rapid economic expansion.For participants in these projects,understand how to adapt the proper and efficient management strategies is critical.In this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model development.Moreover,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

  17. Mitigation technique for use of CMOS image sensors in mega-joule class laser radiative environment

    Presented is a new mitigation technique to improve the radiation tolerance of CMOS image sensors to the radiation constraints associated to the fusion by inertial confinement experiments at mega-joule class laser facilities. Using the global reset mode, results acquired at the OMEGA facility show the efficiency of this technique to reduce by more than 70% the number of white pixels induced by the mixed 14 MeV neutron and gamma-ray pulse. (authors)

  18. Improving Customer Satisfaction and Customer Service Levels : Case: Nakumatt Mega City Supermarket

    Onyango, Shalotte Salmi

    2011-01-01

    The purpose of this thesis was to analyze the current customer satisfaction and service levels of the Nakumatt mega city Supermarket through an efficient customer satisfaction survey. It is important for a company to work towards satisfying customers’ needs and expectations in order to flourish. The main objective of the study was to discover solutions to improve customer satisfaction and to increase the level of Nakumatt customer services in order to retain and attract new customers. Ano...

  19. Sport mega-events: can legacies and development be equitable and sustainable?

    Jay Coakley; Doralice Lange de Souza

    2013-01-01

    Sport mega-events (SMEs) involve struggles to determine the definition of legacy and the outcome priorities that guide legacy planning, funding, and implementation processes. History shows that legacies reflect the interests of capital, and legacy benefits are enjoyed primarily, if not exclusively, by powerful business interests, a few political leaders, and organizations that govern high performance sports. This paper addresses challenges faced by cities and countries that host SMEs, and sho...

  20. Detection of an antioxidant profile in the human brain in vivo via double editing with MEGA-PRESS.

    Terpstra, Melissa; Marjanska, Malgorzata; Henry, Pierre-Gilles; Tkác, Ivan; Gruetter, Rolf

    2006-12-01

    Vitamin C (ascorbate) and glutathione (GSH) are the two most concentrated non-enzymatic antioxidants in the human brain. Double editing with (DEW) MEGA-PRESS at 4T was designed in this study to measure both antioxidants in the same amount of time previously required to measure one. In the occipital lobe of four human subjects, resolved ascorbate (Asc) and GSH resonances were detected repeatedly and simultaneously using DEW MEGA-PRESS. The Asc and GSH concentrations measured using LCModel analysis of DEW MEGA-PRESS spectra were 0.8 +/- 0.1 and 1.0 +/- 0.1 micromol/g (mean +/- SD), with average Cramer-Rao lower bounds (CRLB) of 10% and 7%, respectively. Aside from the effects of J-modulation at a common echo time (TE), double editing did not compromise sensitivity. To determine the extent to which the oxidized forms of Asc and GSH contribute to DEW MEGA-PRESS spectra in vivo, chemical shifts and coupling constants for dehydroascorbate (DHA) and oxidized glutathione (GSSG) were measured at physiologic pH and temperature. DHA does not contribute to the 3.73 ppm DEW MEGA-PRESS Asc resonance. GSSG contributions to the DEW MEGA-PRESS GSH resonance (3.0 ppm) are negligible under physiologic conditions, and would be evidenced by a distinct GSSG resonance (3.3 ppm) at exceptionally high concentrations. PMID:17089366

  1. Construction of a eukaryotic expression plasmid of Humanin*

    Luo, Ben-yan; Chen, Xiang-ming; Tang, Min; Chen, Feng; Chen, Zhi

    2004-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1(-)-Humanin. Methods: The recombinant plasmid pGEMEX-1-Humanin was digested with restriction endonucleases BamH I and Hind III and the Humanin gene fragments, about 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1(-) and the recombinant plasmids pcDNA3.1(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA successfully produced a band whic...

  2. Characterization of a plasmid from moderately halophilic eubacteria

    Fernández Castillo, Rosario; Vargas, C.; Nieto Gutiérrez, Joaquín José; Ventosa Ucero, Antonio; Ruiz Berraquero, Francisco

    1992-01-01

    A plasmid has been isolated for the first time from moderately halophilic eubacteria. Halomonas elongata, Halomonrrs halmphila, Deleya halophila and Vibrio costkola were found to harbour an 11.5 kbp plasmid (pMH1). The plasmid was isolated and characterized after transformation into Escherichia coh'JM101 cells. A restriction map was constructed, and unique restriction sites for EcoRI, EcoRV and ClaI were detected. The occurrence of such a plasmid in the original halophilic strains was confirm...

  3. Characterization of Chlamydia trachomatis Plasmid-Encoded Open Reading Frames

    Gong, Siqi; Yang, Zhangsheng; Lei, Lei; Shen, Li; Zhong, Guangming

    2013-01-01

    The recent success in transformation of Chlamydia trachomatis represents a major advancement in Chlamydia research. Plasmid-free C. trachomatis serovar L2 organisms can be transformed with chlamydial plasmid-based shuttle vectors pGFP::SW2 and pBRCT. Deletion of plasmid genes coding for Pgp1 to Pgp8 in pBRCT led to the identification of Pgp1, -2, -6, and -8 as plasmid maintenance factors; Pgp4 as a transcriptional regulator of chlamydial virulence-associated gene expression; and Pgp3, -5, and...

  4. Plasmid P1 replication: negative control by repeated DNA sequences.

    Chattoraj, D; Cordes, K.; Abeles, A

    1984-01-01

    The incompatibility locus, incA, of the unit-copy plasmid P1 is contained within a fragment that is essentially a set of nine 19-base-pair repeats. One or more copies of the fragment destabilizes the plasmid when present in trans. Here we show that extra copies of incA interfere with plasmid DNA replication and that a deletion of most of incA increases plasmid copy number. Thus, incA is not essential for replication but is required for its control. When cloned in a high-copy-number vector, pi...

  5. Identification of plasmid partition function in coryneform bacteria

    Kurusu, Yasurou; Satoh, Yukie; Inui, Masayuki; Kohama, Keiko; Kobayashi, Miki; Terasawa, Masato; Yukawa, Hideaki (Mitsubishi Petrochemical Co., Ltd., Ibaraki (Japan))

    1991-03-01

    The authors have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. This fragment was able to stabilize the unstable plasmids in cis but not in trans.

  6. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    Bahig E.  Deeb; Abdullah D. Altalhi

    2009-01-01

    Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of s...

  7. Photonic plasmid stability of transformed Salmonella Typhimurium: A comparison of three unique plasmids

    Lay Donald

    2009-07-01

    Full Text Available Abstract Background Acquiring a highly stable photonic plasmid in transformed Salmonella Typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella Typhimurium (S. typh-lux using three different plasmids and characterize their respective photonic properties. Results In presence of ampicillin (AMP, S. typh-lux with pCGLS-1, pAK1-lux and pXEN-1 plasmids exhibited 100% photon-emitting colonies over a 10-d study period. Photon emitters of S. typh-lux with pCGLS-1, pAK1-lux and pXEN-1 without AMP selection decreased over time (P 7 to 1 × 109 CFU, P 0.05; although photonic emissions across a range of bacterial concentrations were not different (1 × 104 to 1 × 106 CFU, P > 0.05. For very low density bacterial concentrations imaged in 96 well plates photonic emissions were positively correlated with bacterial concentration (P 3 to 1 × 105 CFU low to high were different in the 96-well plate format (P Conclusion These data characterize photon stability properties for S. typh-lux transformed with three different photon generating plasmids that may facilitate real-time Salmonella tracking using in vivo or in situ biophotonic paradigms.

  8. Photonic Plasmid Stability of Transformed Salmonella Typhimurium: A Comparison of Three Unique Plasmids

    Background: Acquiring a highly stable photonic plasmid in transformed Salmonella Typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella Typhimurium (S....

  9. Photonic plasmid stability of transformed Salmonella typhimurium: A comparison of three unique plasmids

    Acquiring a highly stable photonic plasmid in transformed Salmonella typhimurium for use in biophotonic studies of bacterial tracking in vivo is critical to experimental paradigm development. The objective of this study was to determine stability of transformed Salmonella typhimurium (S. typh-lux) u...

  10. Mega clinical trials which have shaped the RAS intervention clinical practice.

    Düsing, Rainer

    2016-06-01

    Following extensive clinical research, drugs affecting the renin-angiotensin system have been used for the treatment of patients with congestive heart failure, myocardial infarction, hypertension, diabetic nephropathy, chronic renal failure and for reducing the risk of developing major cardiovascular (CV) events. This review examines all mega trials (those involving >1000 patients) and smaller pivotal trials involving angiotensin-converting enzyme inhibitors (ACE-Is; 25 mega trials) and angiotensin receptor blockers (ARBs; 27 mega trials) to provide perspective on the huge database of evidence that has accumulated on the use of these drugs. Our review demonstrates that ACE-Is and ARBs are generally as effective as conventional therapies in the treatment of hypertension, but offer additional cardioprotective benefits in patients with heart failure, and in those who have experienced myocardial infarction. Also, both ACE-Is and ARBs are capable of renal protection in addition to their blood-pressure-lowering effects. Although ACE-Is and ARBs provide major benefits to CV patients, doubts remain over the concept of blood-pressure-independent CV protection offered by both classes of drugs. ACE-Is and ARBs appear to be equally effective with respect to morbidity and mortality endpoints, but ARBs are better tolerated. Considering the available evidence, the combined use of an ACE-I and ARB should be avoided and full doses of either ACE-I or ARB should be aimed for as evidence suggests they provide a greater prognostic benefit. PMID:27271312

  11. MegaTevs: single-chain dual nucleases for efficient gene disruption.

    Wolfs, Jason M; DaSilva, Matthew; Meister, Sarah E; Wang, Xu; Schild-Poulter, Caroline; Edgell, David R

    2014-07-01

    Targeting gene disruptions in complex genomes relies on imprecise repair by the non-homologous end-joining DNA pathway, creating mutagenic insertions or deletions (indels) at the break point. DNA end-processing enzymes are often co-expressed with genome-editing nucleases to enhance the frequency of indels, as the compatible cohesive ends generated by the nucleases can be precisely repaired, leading to a cycle of cleavage and non-mutagenic repair. Here, we present an alternative strategy to bias repair toward gene disruption by fusing two different nuclease active sites from I-TevI (a GIY-YIG enzyme) and I-OnuI E2 (an engineered meganuclease) into a single polypeptide chain. In vitro, the MegaTev enzyme generates two double-strand breaks to excise an intervening 30-bp fragment. In HEK 293 cells, we observe a high frequency of gene disruption without co-expression of DNA end-processing enzymes. Deep sequencing of disrupted target sites revealed minimal processing, consistent with the MegaTev sequestering the double-strand breaks from the DNA repair machinery. Off-target profiling revealed no detectable cleavage at sites where the I-TevI CNNNG cleavage motif is not appropriately spaced from the I-OnuI binding site. The MegaTev enzyme represents a small, programmable nuclease platform for extremely specific genome-engineering applications. PMID:25013171

  12. The effects of the MEGA BORG spill on Gulf of Mexico shrimp

    A brown shrimp stock model was developed at the NMFS Galveston Laboratory to assess the effects of the MEGA BORG oil spill on the brown shrimp population along the Texas coast. Water and sediment samples from near the MEGA BORG spill area were collected and analyzed by the Geochemical and Environmental Research Group at Texas A ampersand M University. Hydrocarbon concentrations found at the sediment collection stations ranged from 1.38 ug/g to 7.42 ug/g, while concentrations at the water column sampling sites ranged from 0.69 ug/l to 27.39 ug/l. Evaluation of chromatograms and analytical data suggested that sediments from the area contained primarily biogenic hydrocarbons. Only one station had elevated hydrocarbon levels. However, these values were only three to five times higher than the concentrations measured at the other stations. Evaluation of the water samples from the area showed only very low concentration levels of hydrocarbons were present in the water column. A bioassay study was conducted by the US Environmental Protection Agency, Environmental Research Laboratory in Gulf Breeze, Florida. The main conclusion from the bioassay study was that the concentrations of hydrocarbons measured at the field sites where water samples were taken tended to be three orders of magnitude lower than the hydrocarbon concentrations causing toxic responses in mysid and white shrimp. There were no detected effects of the brown shrimp population along the Texas coast from the MEGA BORG oil spill

  13. Radar scattering of linear dunes and mega-yardangs: Application to Titan

    Paillou, Philippe; Radebaugh, Jani; Wall, Stephen

    2015-01-01

    The Ku-band (13.8 GHz - 2.2 cm) RADAR instrument onboard the Cassini-Huygens spacecraft has revealed the richness of the surface of Titan, as numerous seas, lakes, rivers, cryo-volcanic flows and vast dune fields have been discovered. Linear dunes are a major geomorphological feature present on Titan, covering up to 17% of its surface, mainly in equatorial regions. However, the resolution of the RADAR instrument is not good enough to allow a detailed study of the morphology of these features. In addition, other linear wind-related landforms, such as mega-yardangs (linear wind-abraded ridges formed in cohesive rocks), are likely to present a comparable radar signature that could be confused with the one of dunes. We conducted a comparative study of the radar radiometry of both linear dunes and mega-yardangs, based on representative terrestrial analogues: the linear dunes located in the Great Sand Sea in western Egypt and in the Namib Desert in Namibia, and the mega-yardangs observed in the Lut Desert in easter...

  14. Wireless laser range finder system for vertical displacement monitoring of mega-trusses during construction.

    Park, Hyo Seon; Son, Sewook; Choi, Se Woon; Kim, Yousok

    2013-01-01

    As buildings become increasingly complex, construction monitoring using various sensors is urgently needed for both more systematic and accurate safety management and high-quality productivity in construction. In this study, a monitoring system that is composed of a laser displacement sensor (LDS) and a wireless sensor node was proposed and applied to an irregular building under construction. The subject building consists of large cross-sectional members, such as mega-columns, mega-trusses, and edge truss, which secured the large spaces. The mega-trusses and edge truss that support this large space are of the cantilever type. The vertical displacement occurring at the free end of these members was directly measured using an LDS. To validate the accuracy and reliability of the deflection data measured from the LDS, a total station was also employed as a sensor for comparison with the LDS. In addition, the numerical simulation result was compared with the deflection obtained from the LDS and total station. Based on these investigations, the proposed wireless displacement monitoring system was able to improve the construction quality by monitoring the real-time behavior of the structure, and the applicability of the proposed system to buildings under construction for the evaluation of structural safety was confirmed. PMID:23648650

  15. Wireless Laser Range Finder System for Vertical Displacement Monitoring of Mega-Trusses during Construction

    Hyo Seon Park

    2013-05-01

    Full Text Available As buildings become increasingly complex, construction monitoring using various sensors is urgently needed for both more systematic and accurate safety management and high-quality productivity in construction. In this study, a monitoring system that is composed of a laser displacement sensor (LDS and a wireless sensor node was proposed and applied to an irregular building under construction. The subject building consists of large cross-sectional members, such as mega-columns, mega-trusses, and edge truss, which secured the large spaces. The mega-trusses and edge truss that support this large space are of the cantilever type. The vertical displacement occurring at the free end of these members was directly measured using an LDS. To validate the accuracy and reliability of the deflection data measured from the LDS, a total station was also employed as a sensor for comparison with the LDS. In addition, the numerical simulation result was compared with the deflection obtained from the LDS and total station. Based on these investigations, the proposed wireless displacement monitoring system was able to improve the construction quality by monitoring the real-time behavior of the structure, and the applicability of the proposed system to buildings under construction for the evaluation of structural safety was confirmed.

  16. Mega-heatwave temperatures due to combined soil desiccation and atmospheric heat accumulation

    Miralles, Diego G.; Teuling, Adriaan J.; van Heerwaarden, Chiel C.; Vilà-Guerau de Arellano, Jordi

    2014-05-01

    The recent European mega-heatwaves of 2003 and 2010 broke temperature records across Europe. Although events of this magnitude were unprecedented from a historical perspective, they are expected to become common by the end of the century. However, our understanding of extreme heatwave events is limited and their representation in climate models remains imperfect. Here we investigate the physical processes underlying recent mega-heatwaves using satellite and balloon measurements of land and atmospheric conditions from the summers of 2003 in France and 2010 in Russia, in combination with a soil-water-atmosphere model. We find that, in both events, persistent atmospheric pressure patterns induced land-atmosphere feedbacks that led to extreme temperatures. During daytime, heat was supplied by large-scale horizontal advection, warming of an increasingly desiccated land surface and enhanced entrainment of warm air into the atmospheric boundary layer. Overnight, the heat generated during the day was preserved in an anomalous kilometres-deep atmospheric layer located several hundred metres above the surface, available to re-enter the atmospheric boundary layer during the next diurnal cycle. This resulted in a progressive accumulation of heat over several days, which enhanced soil desiccation and led to further escalation in air temperatures. Our findings suggest that the extreme temperatures in mega-heatwaves can be explained by the combined multi-day memory of the land surface and the atmospheric boundary layer.

  17. Bacterial Mitosis: ParM of Plasmid R1 Moves Plasmid DNA by an Actin-like Insertional Polymerization Mechanism

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette;

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...... movement is powered by insertional polymerization of ParM. Consistently, we find that segregating plasmids are positioned at the ends of extending ParM filaments. Thus, the process of R1 plasmid segregation in E. coli appears to be mechanistically analogous to the actin-based motility operating...

  18. Degradative Plasmid and Heavy Metal Resistance Plasmid Naturally Coexist in Phenol and Cyanide Assimilating Bacteria

    Bahig E.  Deeb

    2009-01-01

    Full Text Available Problem statement: Heavy metals are known to be powerful inhibitors of xenobiotics biodegradation activities. Alleviation the inhibitory effect of these metals on the phenol biodegradation activities in presence of heavy metals resistant plasmid was investigated. Approach: Combination of genetic systems of degradation of xenobiotic compound and heavy metal resistance was one of the approaches to the creation of polyfunctional strains for bioremediation of soil after co-contamination with organic pollutants and heavy metals. Results: A bacterial strain Pseudomonas putida PhCN (pPhCN1, pPhCN2 had been obtained. This bacterium contained two plasmids, a 120 Kb catabolic plasmid that encode for breakdown of phenol (pPhCN1 and pPhCN2 plasmid (100 Kb that code for cadmium and copper resistant. Cyanide assimilation by this bacterium was encoded by chromosomal genes. The inhibitory effect of cadmium (Cd2+ or copper (Cu2+ on the degradation of phenol and cyanide by P. putida strains PhCN and PhCN1 (contained pPhCN1 were investigated. The resistant strain PhCN showed high ability to degrade phenol and cyanide in presence of Cd2+ or Cu2+ comparing with the sensitive strain PhCN1. In addition, Cd2+ or Cu2+ was also found to exert a strong inhibitory effect on the C23O dioxygenase enzyme activity in the presence of cyanide as a nitrogen source. Conclusion: The presence of heavy metal resistance plasmid alleviated the inhibitory effect of metals on the phenol and cyanide assimilation by resistant strain.

  19. Induced mutagenesis of plasmids and chromosomal genes inserted into plasmid DNA 1. Mutagenic effects of irradiations

    Effect of two physical agents: UV- and γ-radiation has been considered in comparison. DNA of RSF2124 plasmid, determining colcine synthesis and ampicillin resistance, was used as a model. Mutagenous effect is taken into account according to the appearance of Col--mutants, which are not capable of colicine synthesis. Lethal effect is determined according to ampicillin marker inactivation. After reisolation of plasmid DNA from mutant transformant, new traits and antibiotic resistance are preserved during subsequent transformations and reseedings of transformed colonies, which proves mutational nature of the transformations. Under short-wave UV irradiation (lambda=254 nm) of RSF2124 DNA a clear mutagenous effect is detected: relative amount of Col--mutants at the optimum for mutagenesis doses increased by a factor of 10. Under conditions of W-reactivation (additional UV-irradiation of recipient cells of wild C600 type) of lethal injuries an increase in mutagenous effect was observed, which is reliable for 95%. A distinct increase in mutagenesis (approximately by a factor of 4) is observed during UV-irradiation in small doses of only one recipient cell (a so-called indirect UV-mutagenesis). Thus, according to its ability to W- and indirect UV-mutagenesis plasmid DNA behaves as DNA of moderate phages, which can testify to their evolution relationship. Treatment of plasmid DNA with acridine orange before UV-irradiation protected only from lethal injuries. γ-irradiation of 60Co at inactivation approximately 10-2 increased by an order the yield of Col--mutants. The presence of the plasmid in a cell did not affect its UV-resistance

  20. Mutations in an antisense RNA, involved in the replication control of a repABC plasmid, that disrupt plasmid incompatibility and mediate plasmid speciation.

    Rivera-Urbalejo, América; Pérez-Oseguera, Ángeles; Carreón-Rodríguez, Ofelia E; Cevallos, Miguel A

    2015-03-01

    The maintenance of large plasmid in a wide variety of alpha-proteobacteria depends on the repABC replication/segregation unit. The intergenic repB-repC region of these plasmids encodes a countertranscribed RNA (ctRNA) that modulates the transcription/translation rate of RepC, the initiator protein. The ctRNA acts as a strong incompatibility factor when expressed in trans. We followed a site directed mutagenesis approach to map those sequences of the ctRNA that are required for plasmid incompatibility and for plasmid replication control. We found that the first three nucleotides of the 5'-end of the ctRNA are essential for interactions with its target RNA. We also found that stretches of 4-5 nucleotides of non-complementarity within the first 10 nucleotides of the left arm of the ctRNA and the target RNA are sufficient to avoid plasmid incompatibility. Additionally, miniplasmid derivatives expressing ctRNAs with mutations in the 5' end or small deletions in the ctRNA are capable of controlling their own replication and coexisting with the parental plasmid. We suggest that a mechanism that could have a crucial role in the speciation process of repABC plasmids is to accumulate enough changes in this small region of the ctRNA gene to disrupt heteroduplex formation between the target RNA of one plasmid and the ctRNA of the other. Plasmids carrying these changes will not have defects in their maintenance. PMID:25644116

  1. Resident Exposure to Peripheral Nerve Surgical Procedures During Residency Training.

    Gil, Joseph A; Daniels, Alan H; Akelman, Edward

    2016-05-01

    Background Variability in case exposures has been identified for orthopaedic surgery residents. It is not known if this variability exists for peripheral nerve procedures. Objective The objective of this study was to assess ACGME case log data for graduating orthopaedic surgery, plastic surgery, general surgery, and neurological surgery residents for peripheral nerve surgical procedures and to evaluate intraspecialty and interspecialty variability in case volume. Methods Surgical case logs from 2009 to 2014 for the 4 specialties were compared for peripheral nerve surgery experience. Peripheral nerve case volume between specialties was performed utilizing a paired t test, 95% confidence intervals were calculated, and linear regression was calculated to assess the trends. Results The average number of peripheral nerve procedures performed per graduating resident was 54.2 for orthopaedic surgery residents, 62.8 for independent plastic surgery residents, 84.6 for integrated plastic surgery residents, 22.4 for neurological surgery residents, and 0.4 for surgery residents. Intraspecialty comparison of the 10th and 90th percentile peripheral nerve case volume in 2012 revealed remarkable variability in training. There was a 3.9-fold difference within orthopaedic surgery, a 5.0-fold difference within independent plastic surgery residents, an 8.8-fold difference for residents from integrated plastic surgery programs, and a 7.0-fold difference within the neurological surgery group. Conclusions There is interspecialty and intraspecialty variability in peripheral nerve surgery volume for orthopaedic, plastic, neurological, and general surgery residents. Caseload is not the sole determinant of training quality as mentorship, didactics, case breadth, and complexity play an important role in training. PMID:27168883

  2. Shared residence: lessons from Sweden

    Newnham, Annika

    2011-01-01

    This article, which draws on Swedish experience, argues that the English courts are currently using the shared residence order in ways that are unlikely either to benefit children or produce the intended results. Shared residence is considerably more demanding than co-parenting within an intact family, and attempts to use this order to improve parental co-operation are likely to prove counter productive. Using shared residence to send symbolic messages about parental status is not only contra...

  3. Construction and Application of R Prime Plasmids, Carrying Different Segments of an Octopine Ti Plasmid from Agrobacterium tumefaciens, for Complementation of vir Genes

    Hille, Jacques; Klasen, Ina; Schilperoort, Rob

    1982-01-01

    Several R prime plasmids have been obtained with high efficiency, by enclosing the R plasmid replicator, in an R::Ti cointegrate plasmid, between two copies of the transposon Tn1831, in the same orientation. These R primes carry different segments of an octopine Ti plasmid, and are compatible with T

  4. Production and pharmaceutical formulation of plasmid DNA vaccines

    van der Heijden, I.

    2013-01-01

    Research leading to the thesis ‘Production and pharmaceutical formulation of plasmid DNA vaccines‘ can be divided into two parts. The first part describes the development of a Good Manufacturing Practice (GMP) compliant plasmid DNA production process of pDNA vaccines for the treatment of Human papil

  5. Homology of plasmids in strains of unicellular cyanobacteria

    Hondel, C.A.M.J.J. van den; Keegstra, W.; Borrias, W.E.; Arkel, G.A. van

    1979-01-01

    Six strains of unicellular cyanobacteria were examined for the presence of plasmids. Analysis of lysates of these strains by CsCl-ethidium bromide density centrifugation yielded a major chromosomal DNA band and a minor band containing covalently closed circular plasmid DNA, as shown by electron micr

  6. Plasmid-encoded copper resistance and precipitation by Mycobacterium scrofulaceum.

    Erardi, F X; Failla, M L; Falkinham, J. O.

    1987-01-01

    A copper-tolerant Mycobacterium scrofulaceum strain was able to remove copper from culture medium by sulfate-dependent precipitation as copper sulfide. Such precipitation of copper sulfide was not observed in a derivative that lacks a 173-kilobase plasmid. In addition, the plasmid-carrying strain has a sulfate-independent copper resistance mechanism.

  7. Two novel conjugative plasmids from a single strain of Sulfolobus

    Erauso, G.; Stedman, K.M.; Werken, van de H.J.G.; Zillig, W.; Oost, van der J.

    2006-01-01

    Two conjugative plasmids (CPs) were isolated and characterized from the same 'Sulfolobus islandicus' strain, SOG2/4, The plasmids were separated from each other and transferred into Sulfolobus soltataricus. One has a high copy number and is not stable (pSOG1) whereas the other has a low copy number

  8. Inc A/C Plasmids in Multidrug resistant Salmonella enterica

    Bacteria plasmids are fragments of extra-chromosomal double stranded deoxyribonucleic acid (DNA) that can contain a variety of genes beneficial to the survival of the host bacteria. Classification and tracking of plasmids is beneficial because they are potentially a medium of horizontal gene transf...

  9. Transformation of Bacillus subtilis by single-stranded plasmid DNA.

    Rudolph, C F; Schmidt, B J; Saunders, C W

    1986-01-01

    The single-stranded form of a pE194-based plasmid transformed Bacillus subtilis protoplasts at least as efficiently as did the double-stranded plasmid, but the single-stranded form did not detectably transform B. subtilis competent cells.

  10. Curing of the 2 mu DNA plasmid from Saccharomyces cerevisiae.

    Toh-e, A; Wickner, R B

    1981-01-01

    The 2 mu DNA plasmid is often eliminated from yeast cells when they are transformed with the 2 mu DNA-LEU2-pMB9 composite plasmid pJDB219. Since pJDB219 is subsequently lost with high frequency, derivatives lacking all 2 mu DNA can be prepared from any strain.

  11. Purification of large plasmids with methacrylate monolithic columns.

    Krajnc, Nika Lendero; Smrekar, Franci; Cerne, Jasmina; Raspor, Peter; Modic, Martina; Krgovic, Danijela; Strancar, Ales; Podgornik, Ales

    2009-08-01

    The rapid evolution of gene therapy and DNA vaccines results in an increasing interest in producing large quantities of pharmaceutical grade plasmid DNA. Most current clinical trials involve plasmids of 10 kb or smaller in size, however, future requirements for multigene vectors including extensive control regions may require the production of larger plasmids, e. g., 20 kb and bigger. The objective of this study was to examine certain process conditions for purification of large plasmids with the size of up to 93 kb. Since there is a lack of knowledge about production and purification of bigger plasmid DNA, cell lysis and storage conditions were investigated. The impact of chromatographic system and methacrylate monolithic column on the degradation of plasmid molecules under nonbinding conditions at different flow rates was studied. Furthermore, capacity measurements varying salt concentration in loading buffer were performed and the capacities up to 13 mg of plasmid per mL of the monolithic column were obtained. The capacity flow independence in the range from 130 to 370 cm/h was observed. Using high resolution monolithic column the separation of linear and supercoiled isoforms of large plasmids was obtained. Last but not least, since the baseline separation of RNA and pDNA was achieved, the one step purification on larger CIM DEAE 8 mL tube monolithic column was performed and the fractions were analyzed by CIM analytical monolithic columns. PMID:19598166

  12. Plasmid DNA induces dodecyl triethyl ammonium bromide to aggregate into vesicle

    Xiang Mei Ran; Xia Guo; Jia Tong Ding

    2012-01-01

    Single-chained cationic surfactant dodecyl triethyl ammonium bromide and plasmid DNA together can form vesicles once the concentration of plasmid DNA reaches a critical value (Ccvc).Bigger the size of plasmid DNA,higher the value of Ccvc.

  13. Resident training in pathology: From resident's point of view

    Kemal KÖSEMEHMETOĞLU

    2008-01-01

    Full Text Available In many recent studies in the literature have described and commented on “competency based resident training” in pathology. According to this model, competencies are subclassified in 6 main categories: Patient care, medical knowledge, practice based learning and improvement, interpersonal and communication skills, professionalism, and systems based practice. Assessment of competency forms the main component of this model.Under the framework of Ankara Society of Pathology, a working group, composed of 11 residents, 6 of which representing the Training and Research Hospitals of Ministry of Health and the rest representing the university hospitals in Ankara, was established in order to participate in the think-tank about resident training in pathology. A questionnaire, composed of 12 questions, was prepared. According to this questionnaire, the number of trainers in the university hospitals is much higher than in the commercial hospitals. While the total number of cases and cases per resident do not differ between the university and commercial hospitals, microscopes used for the educational purposes are significantly less in the commercial hospitals, that is due to less number of binocular microscopes. The amount of resident training program, which consists of intra and intersectional meetings, are similar in the university and commercial hospitals, however, theoretic lectures are given only in 3 departments. Residents working in the university hospitals have obviously heavier burden than in the commercial hospitals. Lastly, residents generally exclaimed that the time dedicated to the macroscopy training is less sufficient than time used for the microscopy training.The factors affecting the training of resident in pathology are divided into two main groups: 1 Factors directly affecting training (quality of trainer, time dedicated for education, feed back, eg. and 2 Conditions which waste residents' time. For instant, workload which does need

  14. Construction of a eukaryotic expression plasmid of Humanin

    LUO Ben-yan; CHEN Xiang-ming; TANG Min; CHEN Feng; CHEN Zhi

    2005-01-01

    Objective: To construct a eukaryotic expression plasmid pcDNA3.1 (-)-Humanin. Methods: The recombinant plasm pGEMEX- 1-Humanin was digested with restriction endonucleases BamH I and Hind Ⅲ and the Humanin gene fragments, abo 100 bp length, were obtained. Then the Humanin gene fragments were inserted into eukaryotic expression vector pcDNA3.1 (-) and the recombinant plasmids pcDNA3. l(-)-Humanin were identified by sequencing. Results: Recombinant plasmid DNA succesfully produced a band which had the same size as that of the Humanin positive control. The sequence of recombinant plasmids accorded with the Humnain gene sequence. Conclusions: A eukaryotic expression plasmid of Humanin was successfully constructed.

  15. Permissiveness of soil microbial communities towards broad host range plasmids

    Klümper, Uli

    of fluorescently tagged conjugative plasmids into a soil microbial community in solid-surface filter matings under maximized cell-to-cell contact, followed by quantification of transfer events through advanced fluorescent microscopy, isolation of transconjugants through triple-gated fluorescent activated cell...... using model BHR plasmid pKJK5 introduced through the γ-proteobacterial donor E. coli. I found that the permissiveness towards plasmids was modified through stress on a taxon specific basis and cannot be generally predicted for the whole community. The response of the phylogenetic group was specific...... between phylogenetically distant groups. Finally, I extended the high-throughput method to quantify the potential of a microbial community to actively mobilize and transfer exogenous mobilizable plasmids to its indigenous members. I evaluated the transfer frequency of model plasmid RSF1010 by comparing...

  16. Radiosensitivity of plasmid DNA: role of topology and concentration

    Using the plasmid relaxation assay, the induction of single strand breaks (SSB) by ionizing radiation was investigated in two plasmids of different length, pBS and pSP189. The dose-response was linear for both plasmids but pSP189 exhibited a three times higher sensitivity than mBS. This disparity may be explained by a reduced accessibility to hydroxyl radicals due to a different topology of each plasmid, i.e. degree of compaction, as observed with electron microscopy. pBS plasmid was also exposed at various DNA concentrations to γ rays. The yield of SSB decreased with increasing concentration, suggesting a diminution in the amount of hydroxyl radicals efficient for radiolytic attack. This effect of concentration was also observed with densely ionizing radiation. In conclusion, the accessibility of DNA is a key-parameter in the formation of damage in vitro and in vivo as well. (authors)

  17. Positive selection and compensatory adaptation interact to stabilize non-transmissible plasmids

    Millan, A. San; Peña-Miller, R.; Toll-Riera, M.; Halbert, Z. V.; McLean, A R; Cooper, B. S.; Maclean, R. C.

    2014-01-01

    Plasmids are important drivers of bacterial evolution, but it is challenging to understand how plasmids persist over the long term because plasmid carriage is costly. Classical models predict that horizontal transfer is necessary for plasmid persistence, but recent work shows that almost half of plasmids are non-transmissible. Here we use a combination of mathematical modelling and experimental evolution to investigate how a costly, non-transmissible plasmid, pNUK73, can be maintained in popu...

  18. Requirements for the formation of plasmid-transducing particles of Bacillus subtilis bacteriophage SPP1.

    Alonso, J.C.; Lüder, G; Trautner, T A

    1986-01-01

    We had previously proposed that the production of concatemeric plasmid DNA in plasmid-transducing SPP1 particles is a consequence of phage-directed rolling-circle-type replication of plasmid DNA. The production of such DNA was greatly enhanced when DNA/DNA homology was provided between phage and plasmid DNAs (facilitation of transduction). Here we present evidence that synthesis of concatemeric plasmid DNA can proceed after phage infection under conditions non-permissive for plasmid replicati...

  19. Construction of Streptococcus lactis subsp. lactis Strains with a Single Plasmid Associated with Mucoid Phenotype

    von Wright, Atte; Tynkkynen, Soile

    1987-01-01

    Lactose-fermenting mucoid (Lac+ Muc+) variants of plasmid-free Streptococcus lactis subsp. lactis MG1614 were obtained by protoplast transformation with total plasmid DNA from Muc+S. lactis subsp. cremoris ARH87. By using plasmid DNA from these variants for further transformations followed by novobiocininduced plasmid curing, Lac− Muc+ MG1614 strains containing only a single 30-megadalton plasmid could be constructed. This plasmid, designated pVS5, appeared to be associated with the Muc+ phen...

  20. Plasmid stability in immobilized and free recombinant Escherichia coli JM105(pKK223-200): importance of oxygen diffusion, growth rate, and plasmid copy number.

    de Taxis du Poët, P; Arcand, Y; Bernier, R.; Barbotin, J N; Thomas, D.

    1987-01-01

    Stability of the plasmid pKK223-200 in Escherichia coli JM105 was studied for both free and immobilized cells during continuous culture. The relationship between plasmid copy number, xylanase activity, which was coded for by the plasmid, and growth rate and culture conditions involved complex interactions which determined the plasmid stability. Generally, the plasmid stability was enhanced in cultured immobilized cells compared with free-cell cultures. This stability was associated with modif...

  1. Bifurcation Analysis of a Chemostat Model of Plasmid-Bearing and Plasmid-Free Competition with Pulsed Input

    Zhong Zhao

    2014-01-01

    to the stability of the boundary periodic solution. By use of standard techniques of bifurcation theory, the periodic oscillations in substrate, plasmid-bearing, and plasmid-free organisms are shown when some conditions are satisfied. Our results can be applied to control bioreactor aimed at producing commercial producers through genetically altered organisms.

  2. Residence Hall Seating That Works.

    Wiens, Janet

    2003-01-01

    Describes the seating chosen for residence halls at the Massachusetts Institute of Technology and the University of New England. The seating required depends on ergonomics, aesthetics, durability, cost, and code requirements. In addition, residence halls must have a range of seating types to accommodate various uses. (SLD)

  3. Sexual Education for Psychiatric Residents

    Levine, Stephen B.; Scott, David L.

    2010-01-01

    Objective: The authors seek to promote sexuality curriculum development in departments of psychiatry. Methods: The authors first focus on educational philosophy about what residents can be taught about sexual topics and then provide numerical and narrative resident evaluation data following a 6-month, half day per week rotation in a sexuality…

  4. Cse4 (CenH3) Association with the Saccharomyces cerevisiae Plasmid Partitioning Locus in Its Native and Chromosomally Integrated States: Implications in Centromere Evolution▿ †

    Huang, Chu-Chun; Hajra, Sujata; Ghosh, Santanu Kumar; Jayaram, Makkuni

    2010-01-01

    The histone H3 variant Cse4 specifies centromere identity in Saccharomyces cerevisiae by its incorporation into a special nucleosome positioned at CEN DNA and promotes the assembly of the kinetochore complex, which is required for faithful chromosome segregation. Our previous work showed that Cse4 is also associated with the partitioning locus STB of the 2μm circle—a multicopy plasmid that resides in the yeast nucleus and propagates itself stably. Cse4 is essential for the functional assembly...

  5. La estrategia comunicacional en el sector mega-minero. Un estudio del caso La Alumbrera en Argentina

    Julieta Godfrid

    2016-06-01

    Full Text Available En los últimos años se produjo en la Argentina una rápida expansión de la mega-minería a cielo abierto, lo que vino acompañado de un creciente aumento de la conflictividad socio-ambiental que cuestiona en profundidad las consecuencias de la actividad extractiva. En este contexto, las múltiples críticas a la mega-minería deslegitimaron profundamente la imagen del sector y de las empresas que llevan adelante este tipo de actividad. A partir de allí, las corporaciones mega-mineras se vieron frente a la necesidad de construir una nueva estrategia comunicacional integral que les permitiera mejorar su imagen y construir consenso en torno a la actividad. El presente trabajo indaga en torno a las nuevas estrategias comunicacionales del sector mega-minero que se llevan a cabo bajo el paradigma de la Responsabilidad Social Empresaria y el “marketing experiencial”. Para ello se trabaja a partir del estudio de caso del emprendimiento mega-minero más antiguo del país, la empresa La Alumbrera (Provincia de Catamarca.

  6. Earthquake swarms reveal submarine magma unrest induced by distant mega-earthquakes: Andaman Sea region

    Špičák, Aleš; Vaněk, Jiří

    2016-02-01

    Little is known about earthquake-triggered magma intrusions or eruptions of submarine volcanoes. The analysis of teleseismic earthquake occurrence performed in this study offers a tool to address such enigmatic and inaccessible processes. In the past ten years, the Andaman Sea region repeatedly became a site of shallow earthquake swarms that followed distant mega-earthquakes by days to weeks. The MW 9.1 December 26, 2004 Sumatra-Andaman earthquake was followed by two earthquake swarms about 600 km northward in the Andaman Sea region, delayed by 30 and 35 days, respectively. Earthquakes of one of these seismic episodes, the extensive January 2005 earthquake swarm, migrated laterally at a rate of about 0.25 km per hour during the swarm evolution. The strong Indian Ocean MW 8.6 and 8.2 April 11, 2012 earthquake doublet west of Northern Sumatra was followed by an earthquake swarm approximately 800 km northward in the Andaman Sea region, delayed by 13 days. All the three swarms that followed the 2004 and 2012 mega-earthquakes occurred beneath distinct seamounts and seafloor ridges. Based on the observations of migration of earthquakes during the swarm and swarm occurrence beneath distinct highs at the seafloor, we conclude that these earthquake swarms probably resulted as a consequence of magma unrest induced by static and/or dynamic stress changes following the distant mega-earthquakes. Repeated occurrence of such a phenomenon suggests that the arc magma reservoirs beneath the Andaman Sea have recently reached some form of criticality and are vulnerable to even small stress changes. The Andaman seafloor could thus become a site of submarine volcanic eruptions in near future and deserves close attention of Earth scientists.

  7. Mega-pixel PQR laser chips for interconnect, display ITS, and biocell-tweezers OEIC

    Kwon, O'Dae; Yoon, J. H.; Kim, D. K.; Kim, Y. C.; Lee, S. E.; Kim, S. S.

    2008-02-01

    We describe a photonic quantum ring (PQR) laser device of three dimensional toroidal whispering gallery cavity. We have succeeded in fabricating the first genuine mega-pixel laser chips via regular semiconductor technology. This has been realized since the present injection laser emitting surface-normal dominant 3D whispering gallery modes (WGMs) can be operated CW with extremely low operating currents (μA-nA per pixel), together with the lasing temperature stabilities well above 140 deg C with minimal redshifts, which solves the well-known integration problems facing the conventional VCSEL. Such properties unusual for quantum well lasers become usual because the active region, involving vertically confining DBR structure in addition to the 2D concave WGM geometry, induces a 'photonic quantum ring (PQR)-like' carrier distribution through a photonic quantum corral effect. A few applications of such mega-pixel PQR chips are explained as follows: (A) Next-generation 3D semiconductor technologies demand a strategy on the inter-chip and intra-chip optical interconnect schemes with a key to the high-density emitter array. (B) Due to mounting traffic problems and fatalities ITS technology today is looking for a revolutionary change in the technology. We will thus outline how 'SLEEP-ITS' can emerge with the PQR's position-sensing capability. (C) We describe a recent PQR 'hole' laser of convex WGM: Mega-pixel PQR 'hole' laser chips are even easier to fabricate than PQR 'mesa' lasers. Genuine Laguerre-Gaussian (LG) beam patterns of PQR holes are very promising for biocell manipulations like sorting mouse myeloid leukemia (M1s) cells. (D) Energy saving and 3D speckle-free POR laser can outdo LEDs in view of red GaAs and blue GaN devices fabricated recently.

  8. Air pollution and its impact on human health in mega cities

    One of the major problems faced by the over crowded mega-cities of the world in general and that in third world is the alarming levels of air pollution causing damage to the health of its inhabitants. In Cairo estimated lives lost annually due to air pollution varies between 4000 to 16000 while Delhi has been rated as the most polluted city in the world. Karachi now a mega-city typically represents pollution status of the third world. Major cause of pollution is more than 0.62 millions vehicles on the roads. The pollution due to industries is localized and mainly affects the health of the workers. Measurement carried out for the selected areas along the roads carrying high density traffic show a very high pollution level (CO, 3 to 10 ppm; CO/sub 2/,170 to 350 ppm; HC 0.274 to 0.360 vol. %; particulate matter 67.0 to 565.5 ug/m/sup 3/. A parallel hospital survey to correlate air borne disease with air pollution indicates that over 16600 to 22977 patients suffered from air borne diseases while 6377 from bacterial infection. Analysis showed that 70% of the patients suffering from airborne disease come from the surveyed areas with high level pollution. Cancer is shifting from old age to middle age group indicating deteriorating air environment. Ratio of male to female patients is 2:1, which is indicative of hazardous ambient air quality outside to which men are exposed more than women. The paper discusses in depth the air pollution and its impact on human health in mega cities with Karachi as a case study. (author)

  9. Upgrade of the TAMU MDM-focal plane detector with MicroMegas technology

    Spiridon, A.; Pollacco, E.; Roeder, B. T.; Saastamoinen, A.; Chyzh, R.; Dag, M.; Tribble, R. E.; Trache, L.; Pascovici, G.; De Oliveira, R.

    2016-06-01

    A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10-15% obtained using the existing, conventional ionization chambers.

  10. Tunable mega-ampere electron current propagation in solids by dynamic control of lattice melt.

    MacLellan, D A; Carroll, D C; Gray, R J; Booth, N; Burza, M; Desjarlais, M P; Du, F; Neely, D; Powell, H W; Robinson, A P L; Scott, G G; Yuan, X H; Wahlström, C-G; McKenna, P

    2014-10-31

    The influence of lattice-melt-induced resistivity gradients on the transport of mega-ampere currents of fast electrons in solids is investigated numerically and experimentally using laser-accelerated protons to induce isochoric heating. Tailoring the heating profile enables the resistive magnetic fields which strongly influence the current propagation to be manipulated. This tunable laser-driven process enables important fast electron beam properties, including the beam divergence, profile, and symmetry to be actively tailored, and without recourse to complex target manufacture. PMID:25396375

  11. Development of a hardened imaging system for the Laser MegaJoule

    Rousseau A; Darbon S.; Troussel P.; Caillaud T.; Bourgade J.L.; Turk G; Vigne E.; Hamel M.; Larour J.; Bradley D.; Smalyuk V.; Bell P

    2013-01-01

    The Laser MegaJoule (LMJ) facility will host inertial confinement fusion experiments in order to achieve ignition by imploding a Deuterium-Tritium microballoon. In this context an X-ray imager is necessary to diagnose the core size and shape of the DT-target in the 10–100 keV band in complement of neutron imaging system. Such a diagnostic will be composed of two parts: an X-ray optical system and a detection assembly. Each element will be affected by the harsh environment created by fusion re...

  12. MEGAS: modelling and experiments on gas migration in argillaceous host rocks

    The primary objective of the MEGAS project is to understand the impact of gas generation on argillaceous host rock and this for various generation rates and different host rock conditions. The importance of the phenomena which might occur is determined. The following phenomena are investigated: -reaction of hydrogen with the host rock (clay); - molecular diffusion; -bubble growth; - pressure build up; - creation of preferential pathways and fractures; - two phase flow. The final objective of the project is the validation of a gas migration model; for that purpose, as in situ gas migration experiment is planned in Boom clay at a representative repository depth. 8 refs., 8 figs

  13. New horizons for extreme light physics with mega-science project XCELS

    A short review of the Russian mega-science project XCELS and scientific problems to be solved are presented. We discuss the origin of multi-beam design to attain the highest field magnitude at optimal focusing. Then, we formulate particular physical problems of fundamental interest that can be solved within this project. They include new regimes of single particle motions mostly due to the radiation reaction force (RR) effects when efficient gamma ray generation occurs, new regimes of non-linear electrodynamics, as well as QED resulting in highly efficient plasma converter for gamma rays, and probing non-perturbative QED with dipole or superluminal atto-second pulses

  14. Malaysian Mega Science Framework: The Need for Social Impact and Sustainability Assessment

    Ahmad Zainal A.

    2015-01-01

    Full Text Available This review focuses on issues surrounding wastewater management as part of the National Sustainable Development (2013-2050 under the Malaysian Mega Science Framework. In line with the national priority area of water security, this review will highlight the technical reports compiled by the Academy of Sciences Malaysia (ASM on the challenges of water resource development and wastewater management and treatment. The discussion will dwell on the social impact of pollution in water and wastewater and mitigation plans that need to be put in place to ensure sustainable national development and making water as a National Key Economic Area (NKEA.

  15. Establishment of a production line for the fabrication of mega-curie sealed 60Co sources

    In order to change the status that highly radioactive 60Co sources in China are de- pendent on imports, the fabrication technology of sealed 60Co sources was successfully developed and a mega Curie production line was established. This paper describes the hot cell facilities for the 60Co source encapsulation and quality control, the model and main technical parameters of the sealed 60Co source, the fabrication process, some key techniques in the re- search and development of the sealed 60Co source, etc. (authors)

  16. Road traffic administration and management in the third world mega-city: Lagos, Nigeria

    R.A. Asiyanbola; S.B. Osoba; S.S. Adewale

    2012-01-01

    Observation from the literature shows that a city can only be as big as its transportation facilities can enable its people goes about their businesses, move and distribute their goods and services. In spite of these positive aspects of urban transportation system on one side of the coin, the other side of the coin reflects its negative impact that relate to traffic management and administration and road safety. The daily movement of people and freights within and outside the mega-city of LAG...

  17. MegaSquirt : Asennus, säätäminen ja ohjelmointi

    Kitinmäki, Manne

    2010-01-01

    Tässä työssä esitellään jälkiasennettavan moottorinohjausyksikön, MegaSquirtin asennus Boschin L-Jetronic-yksikön tilalle, sen säätäminen käyttökuntoon sekä oman ohjelmiston tekeminen ohjausyksikön tietojen lukemiseen. Kohdeautona toimii Opel Ascona B vuosimallia 1979, 20E-moottorilla. Asennuksen tarkoituksena on saavuttaa parempi toimivuus tulevaisuudessa, kun moottoria tullaan virittämään enemmän. Laitteisto saatiin asennettua onnistuneesti ja toimimaan kohtalaisen hyvin. Työtä ...

  18. International MegaGauss Science Laboratory at the Institute for Solid State Physics, University of Tokyo

    Takeyama, S.; Kindo, K.

    2006-11-01

    This fiscal year in 2006, the mega-gauss laboratory at Kashiwa, Japan has changed the organization for the purpose of strengthening the high-magnetic field community in Japan. The new facility is composed of two main sections; one is the destructive pulse magnetic field facility with the single turn coil and the electro-magnetic flux compression systems. The part other covers the non-destructive long-pulse magnet coil systems. Our facility will introduce 210 MJ flywheel DC power generator for a 100 T project. Our recent scientific and technological developments are to be briefly described in conjunction with the new projects.

  19. International MegaGauss Science Laboratory at the Institute for Solid State Physics, University of Tokyo

    This fiscal year in 2006, the mega-gauss laboratory at Kashiwa, Japan has changed the organization for the purpose of strengthening the high-magnetic field community in Japan. The new facility is composed of two main sections; one is the destructive pulse magnetic field facility with the single turn coil and the electro-magnetic flux compression systems. The part other covers the non-destructive long-pulse magnet coil systems. Our facility will introduce 210 MJ flywheel DC power generator for a 100 T project. Our recent scientific and technological developments are to be briefly described in conjunction with the new projects

  20. Development of a hardened imaging system for the Laser MegaJoule

    The Laser MegaJoule (LMJ) facility will host inertial confinement fusion experiments in order to achieve ignition by imploding a Deuterium-Tritium micro-balloon. In this context an X-ray imager is necessary to diagnose the core size and shape of the DT-target in the 10-100 keV band in complement of neutron imaging system. Such a diagnostic will be composed of two parts: an X-ray optical system and a detection assembly. Each element will be affected by the harsh environment created by fusion reactions. (authors)

  1. Development of a hardened imaging system for the Laser MegaJoule

    Rousseau A.

    2013-11-01

    Full Text Available The Laser MegaJoule (LMJ facility will host inertial confinement fusion experiments in order to achieve ignition by imploding a Deuterium-Tritium microballoon. In this context an X-ray imager is necessary to diagnose the core size and shape of the DT-target in the 10–100 keV band in complement of neutron imaging system. Such a diagnostic will be composed of two parts: an X-ray optical system and a detection assembly. Each element will be affected by the harsh environment created by fusion reactions.

  2. Plasmid Copy Number Determination by Quantitative Polymerase Chain Reaction.

    Anindyajati; Artarini, A Anita; Riani, Catur; Retnoningrum, Debbie S

    2016-01-01

    Recombinant therapeutic proteins are biopharmaceutical products that develop rapidly for years. Recombinant protein production in certain hosts requires vector expression harboring the gene encoding the corresponding protein. Escherichia coli is the prokaryote organism mostly used in recombinant protein production, commonly using a plasmid as the expression vector. Recombinant protein production is affected by plasmid copy number harboring the encoded gene, hence the determination of plasmid copy number also plays an important role in establishing a recombinant protein production system. On the industrial scale, a low copy number of plasmids are more suitable due to their better stability. In the previous study we constructed pCAD, a plasmid derived from the low copy number pBR322 plasmid. This study was aimed to confirm pCAD's copy number by quantitative polymerase chain reaction (qPCR). Plasmid copy number was determined by comparing the quantification signal from the plasmid to those from the chromosome. Copy number was then calculated by using a known copy number plasmid as a standard. Two pairs of primers, called tdk and ori, were designed for targeting a single gene tdk in the chromosome and a conserved domain in the plasmid's ori, respectively. Primer quality was analyzed in silico using PrimerSelect DNASTAR and PraTo software prior to in vitro evaluation on primer specificity and efficiency as well as optimization of qPCR conditions. Plasmid copy number determination was conducted on E. coli lysates harboring each plasmid, with the number of cells ranging from 10(2)-10(5) cells/μL. Cells were lysed by incubation at 95ºC for 10 minutes, followed by immediate freezing at -4°C. pBR322 plasmid with the copy number of ~19 copies/cell was used as the standard, while pJExpress414-sod plasmid possessing the high copy number pUC ori was also determined to test the method being used. In silico analysis based on primer-primer and primer-template interactions showed

  3. An updated view of plasmid conjugation and mobilization in Staphylococcus.

    Ramsay, Joshua P; Kwong, Stephen M; Murphy, Riley J T; Yui Eto, Karina; Price, Karina J; Nguyen, Quang T; O'Brien, Frances G; Grubb, Warren B; Coombs, Geoffrey W; Firth, Neville

    2016-01-01

    The horizontal gene transfer facilitated by mobile genetic elements impacts almost all areas of bacterial evolution, including the accretion and dissemination of antimicrobial-resistance genes in the human and animal pathogen Staphylococcus aureus. Genome surveys of staphylococcal plasmids have revealed an unexpected paucity of conjugation and mobilization loci, perhaps suggesting that conjugation plays only a minor role in the evolution of this genus. In this letter we present the DNA sequences of historically documented staphylococcal conjugative plasmids and highlight that at least 3 distinct and widely distributed families of conjugative plasmids currently contribute to the dissemination of antimicrobial resistance in Staphylococcus. We also review the recently documented "relaxase-in trans" mechanism of conjugative mobilization facilitated by conjugative plasmids pWBG749 and pSK41, and discuss how this may facilitate the horizontal transmission of around 90% of plasmids that were previously considered non-mobilizable. Finally, we enumerate unique sequenced S. aureus plasmids with a potential mechanism of mobilization and predict that at least 80% of all non-conjugative S. aureus plasmids are mobilizable by at least one mechanism. We suggest that a greater research focus on the molecular biology of conjugation is essential if we are to recognize gene-transfer mechanisms from our increasingly in silico analyses. PMID:27583185

  4. Plasmid-associated sensitivity of Bacillus thuringiensis to UV light

    Spores and vegetative cells of Bacillus thuringiensis were more sensitive to UV light than were spores or cells of plasmid-cured B. thuringiensis strains or of the closely related Bacillus cereus. Introduction of B. thuringiensis plasmids into B. cereus by cell mating increased the UV sensitivity of the cells and spores. Protoxins encoded by one or more B. thuringiensis plasmids were not involved in spore sensitivity, since a B. thuringiensis strain conditional for protoxin accumulation was equally sensitive at the permissive and nonpermissive temperatures. In addition, introduction of either a cloned protoxin gene, the cloning vector, or another plasmid not containing a protoxin gene into a plasmid-cured strain of B. thuringiensis all increased the UV sensitivity of the spores. Although the variety of small, acid-soluble proteins was the same in the spores of all strains examined, the quantity of dipicolinic acid was about twice as high in the plasmid-containing strains, and this may account for the differences in UV sensitivity of the spores. The cells of some strains harboring only B. thuringiensis plasmids were much more sensitive than cells of any of the other strains, and the differences were much greater than observed with spores

  5. Investigation of plasmid-induced growth defect in Pseudomonas putida.

    Mi, Jia; Sydow, Anne; Schempp, Florence; Becher, Daniela; Schewe, Hendrik; Schrader, Jens; Buchhaupt, Markus

    2016-08-10

    Genetic engineering in bacteria mainly relies on the use of plasmids. But despite their pervasive use for physiological studies as well as for the design and optimization of industrially used production strains, only limited information about plasmid induced growth defects is available for different replicons and organisms. Here, we present the identification and characterization of such a phenomenon for Pseudomonas putida transformants carrying the pBBR1-derived plasmid pMiS1. We identified the kanamycin resistance gene and the transcription factor encoding rhaR gene to be causal for the growth defect in P. putida. In contrast, this effect was not observed in Escherichia coli. The plasmid-induced growth defect was eliminated after introduction of a mutation in the plasmid-encoded rep gene, thus enabling construction of the non-toxic variant pMiS4. GFP reporters construct analyses and qPCR experiments revealed a distinctly lowered plasmid copy number for pMiS4, which is probably the reason for alleviation of the growth defect by this mutation. Our work expands the knowledge about plasmid-induced growth defects and provides a useful low-copy pBBR1 replicon variant. PMID:27287537

  6. Sociobiological control of plasmid copy number in bacteria.

    Mukta M Watve

    Full Text Available All genes critical for plasmid replication regulation are located on the plasmid rather than on the host chromosome. It is possible therefore that there can be copy-up "cheater" mutants. In spite of this possibility, low copy number plasmids appear to exist stably in host populations. We examined this paradox using a multilevel selection model. Simulations showed that, a slightly higher copy number mutant could out-compete the wild type. Consequently, another mutant with still higher copy number could invade the first invader. However, the realized benefit of increasing intra-host fitness was saturating whereas that of inter-host fitness was exponential. As a result, above a threshold, intra-host selection was overcompensated by inter-host selection and the low copy number wild type plasmid could back invade a very high copy number plasmid. This led to a rock-paper-scissor (RPS like situation that allowed the coexistence of plasmids with varied copy numbers. Furthermore, another type of cheater that had lost the genes required for conjugation but could hitchhike on a conjugal plasmid, could further reduce the advantage of copy-up mutants. These sociobiological interactions may compliment molecular mechanisms of replication regulation in stabilizing the copy numbers.

  7. Applying Expectancy Theory to residency training: proposing opportunities to understand resident motivation and enhance residency training.

    Shweiki, Ehyal; Martin, Niels D; Beekley, Alec C; Jenoff, Jay S; Koenig, George J; Kaulback, Kris R; Lindenbaum, Gary A; Patel, Pankaj H; Rosen, Matthew M; Weinstein, Michael S; Zubair, Muhammad H; Cohen, Murray J

    2015-01-01

    Medical resident education in the United States has been a matter of national priority for decades, exemplified initially through the Liaison Committee for Graduate Medical Education and then superseded by the Accreditation Council for Graduate Medical Education. A recent Special Report in the New England Journal of Medicine, however, has described resident educational programs to date as prescriptive, noting an absence of innovation in education. Current aims of contemporary medical resident education are thus being directed at ensuring quality in learning as well as in patient care. Achievement and work-motivation theories attempt to explain people's choice, performance, and persistence in tasks. Expectancy Theory as one such theory was reviewed in detail, appearing particularly applicable to surgical residency training. Correlations between Expectancy Theory as a work-motivation theory and residency education were explored. Understanding achievement and work-motivation theories affords an opportunity to gain insight into resident motivation in training. The application of Expectancy Theory in particular provides an innovative perspective into residency education. Afforded are opportunities to promote the development of programmatic methods facilitating surgical resident motivation in education. PMID:25995656

  8. Status and Perspectives of the Mini-MegaTORTORA Wide-field Monitoring System with High Temporal Resolution

    Sergey Karpov

    2013-01-01

    Full Text Available Here we briefly summarize our long-term experience of constructing and operating wide-field monitoring cameras with sub-second temporal resolution to look for optical components of GRBs, fast-moving satellites and meteors. The general hardware requirements for these systems are discussed, along with algorithms for real-time detection and classification of various kinds of short optical transients. We also give a status report on the next generation, the MegaTORTORA multi-objective and transforming monitoring system, whose 6-channel (Mini-MegaTORTORA-Spain and 9-channel prototypes (Mini-MegaTORTORA-Kazan we have been building at SAO RAS. This system combines a wide field of view with subsecond temporal resolution in monitoring regime, and is able, within fractions of a second, to reconfigure itself to follow-up mode, which has better sensitivity and simultaneously provides multi-color and polarimetric information on detected transients.

  9. Separation of plasmid DNA topoisomers by multimodal chromatography.

    Silva-Santos, A Rita; Alves, Cláudia P A; Prazeres, Duarte Miguel F; Azevedo, Ana M

    2016-06-15

    The ability to analyze the distribution of topoisomers in a plasmid DNA sample is important when evaluating the quality of preparations intended for gene therapy and DNA vaccination or when performing biochemical studies on the action of topoisomerases and gyrases. Here, we describe the separation of supercoiled (sc) and open circular (oc) topoisomers by multimodal chromatography. A medium modified with the ligand N-benzyl-N-methyl ethanolamine and an elution scheme with increasing NaCl concentration are used to accomplish the baseline separation of sc and oc plasmid. The utility of the method is demonstrated by quantitating topoisomers in a purified plasmid sample. PMID:27033004

  10. Linearization of donor DNA during plasmid transformation in Neisseria gonorrhoeae.

    Biswas, G D; Burnstein, K. L.; Sparling, P F

    1986-01-01

    We examined the fate of plasmid DNA after uptake during transformation in Neisseria gonorrhoeae. An 11.5-kilobase plasmid, pFA10, was processed to linear double-stranded DNA during uptake by competent cells, but cleavage of pFA10 was not site specific. A minority of pFA10 entered as open circles. A 42-kilobase plasmid, pFA14, was degraded into small fragments during uptake; no intracellular circular forms of pFA14 were evident. Since pFA10 DNA linearized by a restriction enzyme was not furthe...

  11. Irradiation uniformity at the Laser MegaJoule facility in the context of the shock ignition scheme

    Temporal, Mauro; Canaud, B.; Garbett, Warren J.; Ramis Abril, Rafael; Weber, Stefan

    2014-01-01

    The use of the Laser MegaJoule facility within the shock ignition scheme has been considered. In the first part of the study, one-dimensional hydrodynamic calculations were performed for an inertial confinement fusion capsule in the context of the shock ignition scheme providing the energy gain and an estimation of the increase of the peak power due to the reduction of the photon penetration expected during the high-intensity spike pulse. In the second part, we considered a Laser MegaJoule co...

  12. Monte Carlo analysis of the MEGA microlensing events towards M31

    Ingrosso, G; De Paolis, F; Jetzer, P; Nucita, A A; Strafella, F; Jetzer, Ph.

    2005-01-01

    We perform an analytical study and a Monte Carlo (MC) analysis of the main features for microlensing events in pixel lensing observations towards M31. Our main aim is to investigate the lens nature and location of the 14 candidate events found by the MEGA collaboration. Assuming a reference model for the mass distribution in M31 and the standard model for our galaxy, we estimate the MACHO-to-self lensing probability and the event time duration towards M31. Reproducing the MEGA observing conditions, as a result we get the MC event number density distribution as a function of the event full-width half-maximum duration $t_{1/2}$ and the magnitude at maximum $R_{\\mathrm {max}}$. For a MACHO mass of $0.5 M_{\\odot}$ we find typical values of $t_{1/2} \\simeq 20$ day and $R_{\\mathrm {max}} \\simeq 22$, for both MACHO-lensing and self-lensing events occurring beyond about 10 arcminutes from the M31 center. A comparison of the observed features ($t_{1/2}$ and $R_{\\mathrm {max}}$) with our MC results shows that for a MAC...

  13. MegaMol--A Prototyping Framework for Particle-Based Visualization.

    Grottel, Sebastian; Krone, Michael; Muller, Christoph; Reina, Guido; Ertl, Thomas

    2015-02-01

    Visualization applications nowadays not only face increasingly larger datasets, but have to solve increasingly complex research questions. They often require more than a single algorithm and consequently a software solution will exceed the possibilities of simple research prototypes. Well-established systems intended for such complex visual analysis purposes have usually been designed for classical, mesh-based graphics approaches. For particle-based data, however, existing visualization frameworks are too generic - e.g. lacking possibilities for consistent low-level GPU optimization for high-performance graphics - and at the same time are too limited - e.g. by enforcing the use of structures suboptimal for some computations. Thus, we developed the system softwareMegaMol for visualization research on particle-based data. On the one hand, flexible data structures and functional module design allow for easy adaption to changing research questions, e.g. studying vapors in thermodynamics, solid material in physics, or complex functional macromolecules like proteins in biochemistry. Therefore, MegaMol is designed as a development framework. On the other hand, common functionality for data handling and advanced rendering implementations are available and beneficial for all applications. We present several case studies of work implemented using our system as well as a comparison to other freely available or open source systems. PMID:26357030

  14. Natural hazards mapping of mega sea waves on the NW coast of Egypt

    Torab, Magdy; Dalal, Nora

    2015-12-01

    Some boulder fields were deposited by the sea waves during winter storms or by paleo tsunami mega waves and most of these boulders were uprooted from the marine platform and distributed within 90 m of the shoreline, are found up to 4 m above present mean sea level. The objective of this work is defining systematic characterisation of the high-energy depositional contexts working by storms or paleo tsunami deposit, and to reconstruct the history of mega block deposition along the study area, depends upon extensive field surveying and geomorphic mapping by using GIS and GPS techniques as well as statistical analysis of boulders in order to determine both extreme events using the significant wave height and period of maximum observed storms and historical tsunamis along the study area, as well as geomorphic hazard mapping and samples dating. The results show that both possible processes (storm and tsunami waves) can deposit these boulders, it attested at Alexandria for example by the archaeological excavations and historical sources. Tsunami waves and storms cause the displacement of huge boulders from sea bottom and submersible marine terraces (platforms) to the beach due to its major power and ability of carving and graving it is also capable of pulling other boulders from the land and redeposit it on the beach or coastline.

  15. Mega-earthquake recurrences recorded in lacustrine deposits along the Nankai Trough

    Okamura, M.; Matsuoka, H.

    2012-12-01

    We need to understand about mega-earthquake and its cycle for several thousand years after the 2011 off the Pacific coast of Tohoku Earthquake (Mw9.0). We investigated tsunami sediments from the east of Kyushu to the west of Kii Peninsula along the Nankai Torough. Several hundreds of cores yield shallow marine sand and chaotic muddy sand layers intercalated in plant-rich lacustrine sediments. In some case, marine plankton taxa are found in a layer. Almost these layers which cover past 3500 years can be correlated well to the historical earthquake e.g. Tenmu (AD684), Shohei (AD1361) and Hoei (AD1707). These relatively thick tsunami sediments are found in every 300 to 350 years from east of Kyushu Island. Several times in thickness of these Hoei-class tsunami sediments are found from central and eastern-most Shikoku and west of Kii Peninsula. These evidences from tsunami sediment suggest that over Hoei (Mw8.6-8.8) mega-earthquake occur along the Nankai Trough at 2000 years ago.

  16. Mega-science accelerator projects in China and their impact on economy

    Along with the rapid development of national economy in China, a number of mega-science projects have been or being constructed. In respect to the large accelerator-based projects, the Beijing Electron-Positron Colliders (BEPC) and its upgrading project BEPCⅡ, the Hefei Light Source (HLS), the Heavy Ion Research Facility in Lanzhou (HIRFL) and its Cooling Storage Rings (HIRFL-CSR) and the Shanghai Synchrotron Radiation Facility (SSRF) were successfully constructed and put into operation. The Beijing Radioactive Ion Facility (BRIF) and the China Spallation Neutron Source (CSNS) are under construction. A particle accelerator is an integration of many HI-tech components. In order to reach the scientific goal of an accelerator project, a great deal new technologies need to be developed during its construction and operation and thus speed up technology development and this will positively impact on the economy. In this paper, the mega-science accelerator projects are briefly described and applications of accelerators in the economy are reviewed. The paper emphasizes spin-off of the accelerator technology developed during R and D and construction of the projects. Approaches of collaboration between academia and industry are discussed. With some examples, the benefits experienced in the laboratory-industry collaboration and approach of its economic compact are illustrated. (author)

  17. Plasmid pGA1 from Corynebacterium glutamicum codes for a gene product that positively influences plasmid copy number.

    Nesvera, J; Pátek, M; Hochmannová, J; Abrhámová, Z; Becvárová, V; Jelínkova, M; Vohradský, J

    1997-01-01

    The complete nucleotide sequence (4,826 bp) of the cryptic plasmid pGA1 from Corynebacterium glutamicum was determined. DNA sequence analysis revealed four putative coding regions (open reading frame A [ORFA], ORFA2, ORFB, and ORFC). ORFC was identified as a rep gene coding for an initiator of plasmid replication (Rep) according to the high level of homology of its deduced amino acid sequence with the Rep proteins of plasmids pSR1 (from C. glutamicum) and pNG2 (from Corynebacterium diphtheria...

  18. Cloning and Analysis of a Large Plasmid pBMB165 from Bacillus thuringiensis Revealed a Novel Plasmid Organization

    Yueying Wang; Donghai Peng; Zhaoxia Dong; Lei Zhu; Suxia Guo; Ming Sun

    2013-01-01

    In this study, we report a rapid cloning strategy for large native plasmids via a contig linkage map by BAC libraries. Using this method, we cloned a large plasmid pBMB165 from Bacillus thuringiensis serovar tenebrionis strain YBT-1765. Complete sequencing showed that pBMB165 is 77,627 bp long with a GC-content of 35.36%, and contains 103 open reading frames (ORFs). Sequence analysis and comparison reveals that pBMB165 represents a novel plasmid organization: it mainly consists of a pXO2-like...

  19. Gas and Dust Phenomena of Mega-earthquakes and the Cause

    Yue, Z.

    2013-12-01

    A mega-earthquake suddenly releases a large to extremely large amount of kinetic energy within a few tens to two hundreds seconds and over ten to hundreds kilometer distances in the Earth's crust and on ground surface. It also generates seismic waves that can be received globally and co-seismic ground damages such co-seismic ruptures and landslides. However, such vast, dramatic and devastating kinetic actions in the Earth's crustal rocks and on the ground soils cannot be known or predicted by people at few weeks, days, hours, or minutes before they are happening. Although seismologists can develop and use seismometers to report the locations and magnitudes of earthquakes within minutes of their occurrence, they cannot predict earthquakes at present. Therefore, damage earthquakes have caused and would continue to cause huge disasters, fatalities and injuries to our human beings. This problem may indicate that it is necessary to re-examine the cause of mega-earthquakes in addition to the conventional cause of active fault elastic rebounding. In the last ten years, many mega-earthquakes occurred in China and around the Pacific Ocean and caused many casualties to human beings and devastating disasters to environments. The author will give a brief review on the impacts of the mega-earthquakes happened in recent years. He will then present many gas and dust related phenomena associated with the sudden occurrences of these mega earthquakes. They include the 2001 Kunlunshan Earthquake M8.1, 2008 Wenchuan Earthquake M8.0 and the 2010 Yushu Earthquake M7.1 in China, the 2010 Haiti Earthquake M7.0, the 2010 Mexicali Earthquake M7.2, the 2010 Chile Earthquake M8.8, the 2011 Christchurch earthquake M6.3 and the 2011 Japan Earthquake M9.0 around the Pacific Ocean. He will discuss the cause of these gas and dust related phenomena. He will use these phenomena and their common cause to show that the earthquakes were caused the rapid migration and expansion of highly compressed and

  20. Tratamento cirúrgico do megaesôfago recidivado Surgical treatment of recurrent achalasia

    José Luiz Braga de Aquino

    2007-10-01

    Full Text Available OBJETIVO: Avaliar os resultados do tratamento cirúrgico em uma série de pacientes submetidos ao tratamento prévio para megaesôfago que evoluíram com recidiva de sintomas. MÉTODO: Analisou-se os resultados das diversas técnicas operatórias realizadas em 47 pacientes pelo Serviços de Cirurgia Geral e Torácica do HMCP-PUC-Campinas. A morbidade pós-cirúrgica, mortalidade, o alívio ou nova recidiva de sintomas e o tempo de seguimento foram os principais indicadores. Dividiu-se a série em três grupos, de acordo com o grau da afecção: Incipiente (nove casos, Não-avançado (18 casos e avançado (20 casos. As técnicas operatórias utilizadas foram: à cardiomiectomia com fundoplicatura anterior, esofagocardioplastia à Tahl, esofagocardioplastia à Serra-Dória, Esofagectomia Subtotal e Mucosectomia com conservação da túnica muscular esofágica. RESULTADOS: Obteve-se índices de resolutividade satisfatórios com a técnica de cardiomiectomia com fundoplicatura para o megaesôfago Incipiente, com baixa morbidade. Nos megaesôfago não-avançado, as cardiopatias, em especial a esofagocardioplastia à Serra-Dória mostram se mais adequadas. A terapêutica do megaesôfago avançado apresentou as maiores taxas de morbidade e demonstrou superioridade das técnicas mais agressivas em relação às técnicas conservadoras, em especial a mucosectomia com preservação da túnica muscular, sendo esta a técnica com menor morbidade dentro do grupo avançado. CONCLUSÃO: A difícil padronização do tratamento cirúrgico do megaesôfago recidivado deve-se às inúmeras técnicas disponíveis, às habilidades pessoais dos cirurgiões e atenta para a criação de protocolos terapêuticos.BACKGROUND: To evaluate the surgical treatment results in a series of patients submitted to previous treatments for megaesophagus, which their symptoms recurred. METHOD: We analyzed the results of many different surgical techniques performed in 47 patients at the

  1. Residence time vs influence time

    E. J. M. Delhez; de Brye, B.; de Brauwere, A.; Deleersnijder, E.

    2014-01-01

    The concepts of age, residence time, exposure time and influence time provide space and time dependent quantitative measures of the rate at which water masses and pollutants enter and/or leave a control domain. To help avoid confusion between these concepts, this paper provides clear definitions of the residence time and the influence time. The similarities and differences between them are illustrated using both a simplified 1D advection-diffusion model and a realistic two-dimensional model o...

  2. Resilience Approach for Medical Residents

    Bezemer, R.A.; Bos, E.W.

    2014-01-01

    Medical residents are in a vulnerable position. While still in training, they are responsible for patient care. They have a dependent relation with their supervisor and low decision latitude. An intervention was developed to increase individual and system resilience, addressing burnout, patient safety, and intention to leave. A participative development protocol was followed in close collaboration with residents and doctors in a middle-sized general hospital. The evaluation combined a quantit...

  3. A series of template plasmids for Escherichia coli genome engineering.

    Deb, Shalini S; Reshamwala, Shamlan M S; Lali, Arvind M

    2016-06-01

    Metabolic engineering strategies often employ multi-copy episomal vectors to overexpress genes. However, chromosome-based overexpression is preferred as it avoids the use of selective pressure and reduces metabolic burden on the cell. We have constructed a series of template plasmids for λ Red-mediated Escherichia coli genome engineering. The template plasmids allow construction of genome integrating cassettes that can be used to integrate single copies of DNA sequences at predetermined sites or replace promoter regions. The constructed cassettes provide flexibility in terms of expression levels achieved and antibiotics used for selection, as well as allowing construction of marker-free strains. The modular design of the template plasmids allows replacement of genetic parts to construct new templates. Gene integration and promoter replacement using the template plasmids are illustrated. PMID:27071533

  4. Construction and Identification of Plasmid pTA-TUB2

    2003-01-01

    An about 1.40 Kb target gene fragment was yielded by PCR amplification with the plasmid pRB 129,which was identified by restriction enzyme digestion that the PCR product was TU B2 gene.The gene was digested by the restriction enzyme and was linked with pTA plasmid to construct pTA-TU B2 plasmid.The plasmid was transformed into Chaetomium spp.by PEG method and the transformation rate was 27/(2×105) and it is nine times higher than that of pRB 129.The transformants can grow on the PDA containing 1 000 μg*mL-1 carbendazim,which is 1 000 times higher than the original Chaetomium spp.The resistance was stable after 10 times transfer on non-selective medium.

  5. Characterization of Nocardia Plasmid pXT107

    Hai-Yang XIA; Yong-Qiang TIAN; Ran ZHANG; Kai-Chun LIN; Zhong-Jun QIN

    2006-01-01

    Nocardia, Rhodococcus and Streptornyces, all members of the actinomycetes family, are Gram-positive eubacteria with high G+C content and able to form mycelium. We report here a newly identified plasmid pXT107 of Nocardia sp. 107, one of the smallest circular plasmids found in Nocardia.The complete nucleotide sequence of pXT107 consisted of 4335 bp with 65% G+C content, and encoded one replication extragenic palindromic (Rep) and six hypothetical proteins. The Rep, double-strand origin and single-strand origin of pXT107 resembled those of typical rolling-circle-replication plasmids, such as pNI100 of Nocardia, pRE8424 of Rhodococcus and plJ101 of Streptomyces. The Escherichia coli-Nocardia shuttle plasmid pHAQ22, containing thc rep gene of pXT107, is able to propagate in Nocardia but not in Streptomyces.

  6. Plasmid DNA labelled with 14C or 3H

    Plasmid DNA labelled with 14C or 3H in thymine was isolated from the thymine-dependent strain of Escherichia coli 15 SPT bacteria. The specific activity of the plasmid DNA preparations lay in the range from 0.5 to 20 MBq/mg, their relative molecular weight was 1.7 x 106 dalton. Molecular weight, preparation purity, and the degree of damage of the plasmid DNA molecules were examined by UV absorption spectroscopy, by gel electrophoresis, and by electron micrography. The quality of the [thymine-2-14C] plasmid DNA was verified in a diagnostic test for the determination of the anti-dsDNA bonding activity in human serum. (author). 1 tab., 5 figs., 30 refs

  7. Characterization of the Double-Partitioning Modules of R27: Correlating Plasmid Stability with Plasmid Localization

    Trevor D Lawley; Taylor, Diane E.

    2003-01-01

    Plasmid R27 contains two independent partitioning modules, designated Par1 and Par2, within transfer region 2. Par1 is member of the type I partitioning family (Walker-type ATPase), and Par2 is a member of the type II partitioning family (actin-type ATPase). Stability tests of cloned Par1 and Par2 and insertional disruptions of Par1 and Par2 within R27 demonstrated that Par1 is the major stability determinant whereas Par2 is the minor stability determinant. Creation of double-partitioning mut...

  8. The Salmonella typhimurium virulence plasmid encodes a positive regulator of a plasmid-encoded virulence gene.

    Caldwell, A L; Gulig, P A

    1991-01-01

    The 90-kb virulence plasmid of Salmonella typhimurium is necessary for invasion beyond the Peyer's patches to the mesenteric lymph nodes and spleens of orally inoculated mice. Two Tn5 insertions located on the left side of a previously identified 14-kb virulence region (P. A. Gulig and R. Curtiss III, Infect. Immun. 58:3262-3271, 1988) and mapping 272 bp from each other exhibited opposite effects on splenic infection of mice after oral inoculation. spvR23::Tn5 decreased splenic infection by 1...

  9. Research on Trypanosoma cruzi and Analysis of Inflammatory Infiltrate in Esophagus and Colon from Chronic Chagasic Patients with and without Mega

    Eliângela de Castro Côbo

    2012-01-01

    Full Text Available To compare parasitism and inflammatory process in esophagus and colon from chronic chagasic patients, immunohistochemistry was carried out to research for T. cruzi and to evaluate the inflammatory infiltrate in the muscular and myenteric plexus in 39 esophagi (20 with and 19 without megaesophagus and 50 colons (25 with and 25 without megacolon. The frequency of T. cruzi in megaesophagus was 20%, and in megacolon it was 4%. No amastigotes were found in organs without mega; considering the total of esophagi (with and without mega, the frequency of T. cruzi would be 10% and 2% in the colon. Myositis and ganglionitis were more frequent and intense in organs with mega compared to those without mega, and in esophagus compared to colon. Qualitatively, inflammatory infiltration in esophagus and colon, with or without mega, was similar, consisting predominantly of T lymphocytes (CD3+, scarce macrophages (CD68+, and rare B lymphocytes (CD20+.

  10. Comparative analysis of conjugative plasmids mediating gentamicin resistance in Staphylococcus aureus.

    Goering, R. V.; Ruff, E A

    1983-01-01

    Five gentamicin-resistant clinical isolates of Staphylococcus aureus were found to contain self-transmissible plasmids of 32 to 37 megadaltons in size. Restriction endonuclease digests of the plasmids were markedly similar to those of reference plasmids of unrelated geographical origin, thus suggesting the significant contribution of common conjugal plasmids to the emergence of gentamicin resistance in S. aureus populations.

  11. Detection of plasmid deoxyribonucleic acid in an isolate of Lactobacillus acidophilus.

    Klaenhammer, T R; Sutherland, S M

    1980-01-01

    Eight strains of Lactobacillus acidophilus were examined for the presence of plasmid deoxyribonucleic acid, and one, a pig intestinal isolate, showed the presence of a 13.7- and a 6.3-megadalton plasmid. This is the first reported evidence for plasmid deoxyribonucleic acid in Lactobacillus acidophilus. The functions of these plasmids are presently unknown.

  12. Minimum Data Set Active Resident Information Report

    U.S. Department of Health & Human Services — The MDS Active Resident Report summarizes information for residents currently in nursing homes. The source of these counts is the residents MDS assessment record....

  13. Pharmaceutical development of the plasmid DNA vaccine pDERMATT

    Quaak, S.G.L.

    2009-01-01

    The discovery of tumor specific antigens and self tolerance mechanisms against these antigens led to the assumption that antigens circulating at sufficient concentration levels could break this self tolerance mechanism and evoke immunological antitumor effects. pDERMATT (plasmid DNA encoding recombinant MART-1 and tetanus toxin fragment-c) is a plasmid that encodes for MART-1, a melanoma associated antigen that is expressed in a large fraction of melanomas. In animal models administration of ...

  14. A novel chromatographic procedure for purification of bacterial plasmids.

    Bywater, M; Bywater, R; Hellman, L

    1983-07-01

    A new, rapid procedure for purifying bacterial plasmids with high recovery is described. The sequence of operations consists essentially of treatment with alkali, ribonuclease, and proteinase K, followed by chisam extraction and gel filtration on Sephacryl S-1000, and finally a precipitation step using isopropanol at room temperature. The method gives rather good yields of plasmid DNA of high purity, and lends itself to scaling up. PMID:6312836

  15. Isolation and properties of plasmids from Deinococcus radiodurans Sark

    Radioresistant bacterium, Deinococcus radiodurans, can repair completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 kGy. In order to reveal the repair mechanism, it is necessary to develop a cloning vector available for the genetic analysis. We tried to isolate plasmids from D.radiodurans Sark strain. In the present paper the isolation and properties of plasmids were described. (author)

  16. Construction of a bioluminescence reporter plasmid for Francisella tularensis

    Bina, Xiaowen R.; Miller, Mark A.; James E Bina

    2010-01-01

    A Francisella tularensis shuttle vector that constitutively expresses the Photorhabdus luminescens lux operon in type A and type B strains of F. tularensis was constructed. The bioluminescence reporter plasmid was introduced into the live vaccine strain of F. tularensis and used to follow F. tularensis growth in a murine intranasal challenge model in real time by bioluminescence imaging. The results show that the new bioluminescence reporter plasmid represents a useful tool for tularemia rese...

  17. Conjugative plasmid transfer from Enterococcus faecalis to Escherichia coli.

    Trieu-Cuot, P; Carlier, C; Courvalin, P

    1988-01-01

    The possibility of transfer of genetic information by conjugation from gram-positive to gram-negative bacteria was investigated with a pBR322-pAM beta 1 chimeric plasmid, designated pAT191. This shuttle vector, which possesses the tra functions of the streptococcal plasmid pAM beta 1, was conjugatively transferred from Enterococcus faecalis to Escherichia coli with an average frequency of 5 x 10(-9) per donor colony formed after mating.

  18. Intragenic variation by site-specific recombination in the cryptic plasmid of Neisseria gonorrhoeae.

    Hagblom, P; Korch, C; Jonsson, A B; Normark, S

    1986-01-01

    Cryptic plasmid DNA of Neisseria gonorrhoeae was found integrated into the gonococcal chromosome in both plasmid-bearing strains and plasmid-free strains. At several chromosomal locations only segments of the plasmid were found. However, in at least two strains an intact copy of the plasmid seemed to be present with the joints between the plasmid and the chromosomal DNA being located within the cppB gene of the cryptic plasmid. The cppB gene was shown to undergo a sequence-specific intragenic...

  19. Plasmid vector with temperature-controlled gene expression

    In plasmid pBR327, a fragment 169 b.p. long including promotor p3 of the bla gene has been deleted. The deletional derivative so obtained (pSP2) has been used to construct a recombinant plasmid bearing a fragment of phage λ DNA with the p/sub R/ promotor and the gene of the temperature-sensitive repressor cI. It has been shown that the plasmid vector so constructed (pCE119) with promotor cR performs repressor-cI-controlled transcription of the bla gene, as a result of which induction for an hour at 420C leads to an almost 100-fold increase in the amount of product of the bla gene as compared with that at 320C. The possibility of the use of plasmid cPE119 for the expression of other genes has been demonstrated for the case of the semisynthetic β-galactosidase gene of E. coli. In this case, on induction of the cells with recombinant plasmid pCEZ12 for 3 hours at 420C, a 300-fold increase in the amount of active β-galactosidase, as compared with that at 320C, was observed. It is important to point out that under these conditions (at 420C), at least 99% of the cells containing the plasmid retain the phenotype lacZ+, which indicates the stability of the proposed vector system

  20. Transfer of conjugative plasmids among bacteria under environmentally relevant conditions

    Musovic, Sanin

    det oprindelige bakteriesamfund der tager andel i plasmid overførsel blev udviklet. Dyrknings-minimal metode i kombination med reporter gen teknologi og moderne mikroskopi viste en meget høj forekomst af RP4:gfp plasmid overførsel til oprindelige jord bakterier af et bredt værtskab. Der blev også vist......Mobile genetiske elementer (f.eks. plasmider), der ofte bærer ekstra funktioner såsom antibiotikaresistens, eller kataboliske- og xenobiotiske nedbrydnings gener, antages at have en meget vigtigt evolutionær rolle for bakterier. I denne PhD afhandling undersøgte jeg størrelsen af plasmid overførsel...... under de miljørelevante substrat-begrænsede forhold, den del og diversitet af bakteriel samfund der er involveret i overførslen, og effekten af plasmid donor cellens fysiologiske status og de miljørelevante faktorer (selektive tryk) på plasmid spredning. En ny metode til at kvantificere den fraktion af...

  1. The characteristics of micrococcus (deinococcus) radiodurans sark plasmids

    The characterization of micrococcus (deinococcus) radiodurans sark plasmids. This bacterium has been classified as a new genus deinococcus radiodurans which is resistant to gamma-rays. It can repair itself completely almost all of DNA damages including double strand breaks induced by gamma-rays up to about 5 KGy. To reveal the repair mechanism, several investigations had been done to develop a cloning vector available for the genetic analysis. For this purpose D. radiodurans Sark are to be prepared as a vector by studying the characteristics of its plasmid. Plasmids were isolated by electrophoresis using 0.6% low-melting-temperature agarose in TAE and run for 5.5 hours, followed by the identification. An antibiotic marker was also carried out in this experiment to identify its location in the genetic materials of the cell, beside making a restriction map of the plasmid. Results have shown that D. radiodurans Sark has 4 plasmids (P1, P2, P3, and P4) and the refampicin resistant genes were not found in the plasmid. (authors). 14 refs; 4 figs

  2. Plasmid-free T7-based Escherichia coli expression systems.

    Striedner, Gerald; Pfaffenzeller, Irene; Markus, Luchner; Nemecek, Sabine; Grabherr, Reingard; Bayer, Karl

    2010-03-01

    In order to release host cells from plasmid-mediated increases in metabolic load and high gene dosages, we developed a plasmid-free, T7-based E. coli expression system in which the target gene is site-specifically integrated into the genome of the host. With this system, plasmid-loss, a source of instability for conventional expression systems, was eliminated. At the same time, system leakiness, a challenging problem with recombinant systems, was minimized. The efficiency of the T7 RNA polymerase compensates for low gene dosage and provides high rates of recombinant gene expression without fatal consequences to host metabolism. Relative to conventional pET systems, this system permits improved process stability and increases the host cell's capacity for recombinant gene expression, resulting in higher product yields. The stability of the plasmid-free system was proven in chemostat cultivation for 40 generations in a non-induced and for 10 generations in a fully induced state. For this reason plasmid-free systems benefit the development of continuous production processes with E. coli. However, time and effort of the more complex cloning procedure have to be considered in relation to the advantages of plasmid-free systems in upstream-processing. PMID:19891007

  3. Partition-associated incompatibility caused by random assortment of pure plasmid clusters

    Ebersbach, Gitte; Sherratt, David J; Gerdes, Kenn;

    2005-01-01

    Summary Bacterial plasmids and chromosomes encode centromere-like partition loci that actively segregate DNA before cell division. The molecular mechanism behind DNA segregation in bacteria is largely unknown. Here we analyse the mechanism of partition-associated incompatibility for plasmid pB171......, a phenotype associated with all known plasmid-encoded centromere loci. An R1 plasmid carrying par2 from plasmid pB171 was destabilized by the presence of an F plasmid carrying parC1, parC2 or the entire par2 locus of pB171. Strikingly, cytological double-labelling experiments revealed no evidence of long......-lived pairing of plasmids. Instead, pure R1 and F foci were positioned along the length of the cell, and in a random order. Thus, our results raise the possibility that partition-mediated plasmid incompatibility is not caused by pairing of heterologous plasmids but instead by random positioning of pure plasmid...

  4. Applying Expectancy Theory to residency training: proposing opportunities to understand resident motivation and enhance residency training

    Shweiki E

    2015-04-01

    Full Text Available Ehyal Shweiki,1 Niels D Martin,2 Alec C Beekley,1 Jay S Jenoff,1 George J Koenig,1 Kris R Kaulback,1 Gary A Lindenbaum,1 Pankaj H Patel,1 Matthew M Rosen,1 Michael S Weinstein,1 Muhammad H Zubair,2 Murray J Cohen1 1Department of Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA; 2Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA Abstract: Medical resident education in the United States has been a matter of national priority for decades, exemplified initially through the Liaison Committee for Graduate Medical Education and then superseded by the Accreditation Council for Graduate Medical Education. A recent Special Report in the New England Journal of Medicine, however, has described resident educational programs to date as prescriptive, noting an absence of innovation in education. Current aims of contemporary medical resident education are thus being directed at ensuring quality in learning as well as in patient care. Achievement and work-motivation theories attempt to explain people's choice, performance, and persistence in tasks. Expectancy Theory as one such theory was reviewed in detail, appearing particularly applicable to surgical residency training. Correlations between Expectancy Theory as a work-motivation theory and residency education were explored. Understanding achievement and work-motivation theories affords an opportunity to gain insight into resident motivation in training. The application of Expectancy Theory in particular provides an innovative perspective into residency education. Afforded are opportunities to promote the development of programmatic methods facilitating surgical resident motivation in education. Keywords: learning, education, achievement

  5. Tyrosine Partners Coordinate DNA Nicking by the Salmonella typhimurium Plasmid pCU1 Relaxase Enzyme

    Nash, Rebekah P.; Niblock, Franklin C.; Redinbo, Matthew R.

    2011-01-01

    Conjugative plasmid transfer results in the spread of antibiotic resistance genes and virulence factors between bacterial cells. Plasmid transfer is dependent upon the DNA nicking activity of a plasmid-encoded relaxase enzyme. Tyrosine residues within the relaxase cleave the DNA plasmid nic site in a highly sequence-specific manner. The conjugative resistance plasmid pCU1 encodes a relaxase with four tyrosine residues surrounding its active site (Y18,19,26,27). We use activity assays to demon...

  6. Linear Plasmid SLP2 Is Maintained by Partitioning, Intrahyphal Spread, and Conjugal Transfer in Streptomyces▿

    Hsu, Chin-Chen; Chen, Carton W.

    2009-01-01

    Low-copy-number plasmids generally encode a partitioning system to ensure proper segregation after replication. Little is known about partitioning of linear plasmids in Streptomyces. SLP2 is a 50-kb low-copy-number linear plasmid in Streptomyces lividans, which contains a typical parAB partitioning operon. In S. lividans and Streptomyces coelicolor, a parAB deletion resulted in moderate plasmid loss and growth retardation of colonies. The latter was caused by conjugal transfer from plasmid-co...

  7. Transfer of chimeric plasmids among Salmonella typhimurium strains by P22 transduction.

    Orbach, M J; Jackson, E N

    1982-01-01

    Salmonella typhimurium bacteriophage P22 transduced plasmids having P22 sequences inserted in the vector pBR322 with high frequency. Analysis of the structure of the transducing particle DNA and the transduced plasmids indicates that this plasmid transduction involves two homologous recombination events. In the donor cell, a single recombination between the phage and the homologous sequences on the plasmid inserted the plasmid into the phage chromosome, which was then packaged by headfuls int...

  8. Exposing Plasmids as the Achilles’ Heel of Drug-Resistant Bacteria

    Williams, Julia J.; Hergenrother, Paul J.

    2008-01-01

    Many multi-drug resistant bacterial pathogens harbor large plasmids that encode proteins conferring resistance to antibiotics. While the acquisition of these plasmids often enables bacteria to survive in the presence of antibiotics, it is possible that plasmids also represent a vulnerability that can be exploited in tailored antibacterial therapy. This review highlights three recently described strategies designed to specifically combat bacteria harboring such plasmids: Inhibition of plasmid ...

  9. Sequence-nonspecific replication of transfected plasmid DNA in poxvirus-infected cells.

    DeLange, A. M.; McFadden, G

    1986-01-01

    A system in which transfected plasmid DNA replicates in the cytoplasm of poxvirus-infected cells is described. A variety of recombinant plasmids was introduced into poxvirus-infected cells by transfection, and replication of input plasmid DNA was monitored by (i) digestion with restriction enzymes that discriminate between input methylated plasmid DNA and unmethylated DNA produced by replication in mammalian cells; (ii) amplification of intracellular plasmid DNA; and (iii) density shift analy...

  10. Characterization of plasmid burden and copy number in Saccharomyces cerevisiae for optimization of metabolic engineering applications

    Karim, Ashty S.; Curran, Kathleen A.; Alper, Hal S.

    2012-01-01

    Many metabolic engineering and genetic engineering applications in yeast rely on the use of plasmids. Despite their pervasive use and the diverse collections available, there is a fundamental lack of understanding of how commonly used DNA plasmids affect the cell’s ability to grow and how the choice of plasmid components can influence plasmid load and burden. In this study, we characterized the major attributes of the 2μ and centromeric plasmids typically used in yeast by examining the impact...

  11. Hofmeister series salts enhance purification of plasmid DNA by non-ionic detergents

    Lezin, George; Kuehn, Michael R.; Brunelli, Luca

    2011-01-01

    Ion-exchange chromatography is the standard technique used for plasmid DNA purification, an essential molecular biology procedure. Non-ionic detergents (NIDs) have been used for plasmid DNA purification, but it is unclear whether Hofmeister series salts (HSS) change the solubility and phase separation properties of specific NIDs, enhancing plasmid DNA purification. After scaling-up NID-mediated plasmid DNA isolation, we established that NIDs in HSS solutions minimize plasmid DNA contamination...

  12. Comparison of Ti plasmids from three different biotypes of Agrobacterium tumefaciens isolated from grapevines.

    Knauf, V C; Panagopoulos, C G; Nester, E. W.

    1983-01-01

    Twenty-six plasmids from grapevine isolates of Agrobacterium tumefaciens were analyzed by SmaI fingerprinting and by hybridization of nick-translated DNA to DNA of another plasmid. These experiments established that octopine Ti plasmids are not highly conserved, although octopine Ti plasmids from biotype 1 A. tumefaciens strains appeared to be very similar. Octopine Ti plasmids from biotype 3 strains are more variable in terms of host range and SmaI fingerprints, but share extensive DNA homol...

  13. Mega-prizes in medicine: big cash awards may stimulate useful and rapid therapeutic innovation.

    Charlton, Bruce G

    2007-01-01

    Following Horrobin's suggestion of 1986, I argue that offering very large prizes (tens of millions of US dollars, or more) for solving specific therapeutic problems, would be an excellent strategy for promoting the rapid development of effective new treatments. The two mainstream ways of paying for medical research are funding the process with grants or funding the outcome via patent protection. When grants are used to fund the process of research the result tends to be 'pure' science, guided by intrinsic scientific objectives. Practical results, such as useful therapeutic advances, are a by-product. Patent-seeking research, by contrast, is more focused on technology than science. It seeks practical results; and aims to pay for itself (and make a profit) in the long term by generating a patentable product or procedure. Prize-seeking research is subject to different incentives and applicable to different situations than either process-funded or patent-seeking research. Prize seeking researchers have a strong incentive to solve the specified problem as rapidly as possible, but the problem may be solved using old ideas that are scientifically mundane or unpatentable technologies and methods. Prizes therefore seem to generate solutions which are incremental extensions, new applications or novel combinations of already-existing technologies. The main use of mega-prizes in medicine would be to accelerate therapeutic progress in stagnant fields of research and to address urgent problems. For example, medical charities focused on specific diseases should consider accumulating their resources until they can offer a mega-prize for solving a clinical problem of special concern to their patients. Prize money should be big enough to pay for the research and development, the evaluation of the new treatment in a clinical trial, and with a large profit left-over to compensate for the intrinsic risk of competing. Sufficiently large amounts of money, and the prestige and publicity

  14. Shoreface storm morphodynamics and mega-rip evolution at an embayed beach: Bondi Beach, NSW, Australia

    McCarroll, R. Jak; Brander, Robert W.; Turner, Ian L.; Leeuwen, Ben Van

    2016-03-01

    Embayed beach dynamics differ from open beaches due to the nature of headland control. Their resultant morphologies and morphodynamic behaviour are poorly understood due in part to a critical lack of surfzone and nearshore bathymetry observations. This study describes the morphodynamic storm response of a high-energy intermediate, 850 m long embayed beach over a three week period spanning a cluster of storms. A headland and subaqueous ridge protects the northern end of the beach, resulting in an alongshore wave height gradient. Contrary to existing beach state conceptual models, under energetic forcing the beach did not 'reset' or enter a 'cellular mega-rip' beach state. The protected northern end persisted in a low energy state, while the wave exposed southern section transitioned from transverse-bar-and-rip to a complex double-bar system, a process previously undescribed in the literature. Bar-rip morphology at the exposed end of the beach migrated offshore to greater depths, leaving an inner-reflective beach and longshore trough, while a mega-rip channel with 3 m relief developed at the exposed headland. The number of rip channels remained near constant over multiple storm events. Offshore sediment flux was 350 m3/m at the exposed headland and 20 m3/m at the protected end. Alongshore bathymetric non-uniformity decreased over the sub-aerial beach and inner surfzone, but increased in the outer surfzone and beyond. Suggested mechanisms for the persistence of 3D morphology during the cluster of storms include: (i) wave refraction to shore normal within the embayment; (ii) alongshore energy gradients; and (iii) pre-existing bar-rip morphology. Formation of the complex multi-bar state may be related to antecedent morphology, headland geometry, substrate gradient and localised hydrodynamic interactions near the headland. A new conceptual embayed beach state model is proposed for asymmetric, transitional embayed beaches. The model describes a pre-storm embayment where

  15. Episodic sediment disturbance on the mega-splay fault at Tonankai earthquake area, Nankai trough, Japan

    Sakaguchi, A.; Kimura, G.; Strasser, M.; Murayama, M.; Curewitz, D.; Fergusson, C.; Milliken, K.; Nicholson, U.; Screaton, L.; Iodp, E.

    2008-12-01

    The cores at hanging wall (C0004) and footwall (C0008) of mega splay fault are obtained in the Stage 1A of the Nankai Trough Seismogenic Zone Experiment during IODP Expeditions 316 (Kimura et al., 2008). The mega splay fault develops in the area where the coseismic slip (Ichinose et al., 2003) and tsunami source (Baba and Cumming, 2005) are reconstructed for the 1944 Tonankai earthquake. The X-ray computed tomography (X-CT) makes 3D image depending on X-ray attenuation coefficient that is a function of chemical composition and density of the target material. Whereas optical observation my not resolve small differences, emphasizing by the CT-scanner enables to find small difference in sediment composition and structures. The CT image has been taken for all cores during preliminary core processing. Episodic event deposits are found at uppermost core of hanging wall (C0004). The core sample is composed of un-consolidated silt clay and looks homogeneous in optical observation. The X-CT can show complex structure indicating some horizontal layers, scattered mud clasts and mud-filling burrows. The X-CT 3D observation can distinguish a mud clasts and mud-filling burrow. Because tubular burrow is formed by mud- eating worm or mollusks, the cross section area is constant along long axis. On the other hand, the cross section area changes along long axis in distorted shape mud clast. The mud clasts are intercalated between horizontal layers, indicating episodic event. At least five events are observed. The boundary of some mud- clasts are dim, may have suffered diffusion, and this implies very short transportation or in-situ formation. Thus, repeated mud clast deposit was not found at footwall of the fault (C0008). Strong seismic ground motion can shake surface soft sediment, and sediment suspensions were often observed after large earthquakes (Thunell et al., 1999; Itou et al., 2000; Seeber et al., 2007). The difference of occurrence of sediment disturbance between C0004 and

  16. MEGA Node: an implementation of a coarse-grain totally reconfigurable parallel machine

    Blum, M. B.; Burrer, Caroline

    1990-09-01

    The MEGA Node is a loosely coupled highly parallel computer based on transputers. One of its main characteristics is its ability to change the topology of the network using an electronic switch. It covers a range from 128 to 1024 " worker processors" delivering from 550 to 4400 Mflops peak performance. To achieve these performances a hierarchical structure has been adopted. This highly parallel machine is issued from the Esprit I P1085 " Supernode" project. The software has to support a wide spectrum of users going from those who wish to obtain maximum performance from the machine to those who wish to use it as a general purpose multi-user parallel machine. This paper describes the different ways to use the MEGA Node and the software environments provided to satisfy all kind of users. The Helios environment is a good example to explain how an operating system can control this machine particularly the networking management and the fundamental problem of mapping. The MEGA Node has already been used for a wide range of applications like signal/image processing (high and low level) image synthesis scientific and engineering numbercrunching neural network simulation and logic simulation. Only a few of them are discussed in this paper: medical image analysis and vision and ray tracing. 1 Esprit I P1085 project The work done under the Esprit I P1085 project [1] partially funded by CEC was related the development and applications of a low cost high performance multiprocessor machine. The project involved Royal Signals and Radar Establishment (RSRE prime contractor) Inmos Thorn-Emi CRL University of Southampton University of Liverpool Aptor University of Grenoble(Imag) and Telmat Informatique. The objectives of the project were to develop a highly parallel architecture based on transputers and associated system software and applications. To achieve this Inmos developed the T800 transputer starting from the T414 and the consortium defined the whole machine architecture

  17. Student Engagement and Completion in Precalculus Precalculus Mega Section: Efficiently Assisting Student Engagement and Completion with Communications and Information Technology

    Brusi, Rima; Portnoy, Arturo; Toro, Nilsa

    2013-01-01

    The Precalculus Mega Section project was developed with the main purpose of improving the overall performance of the student body in Precalculus, an important gatekeeper course that affects student engagement and completion, with typical drop/failure rates of over 50 percent. Strategies such as integration of technology and additional practice…

  18. Chromosomal mapping of chicken mega-telomere arrays to GGA9, 16, 28 and W using a cytogenomic approach.

    Delany, M E; Gessaro, T M; Rodrigue, K L; Daniels, L M

    2007-01-01

    Four mega-telomere loci were mapped to chicken chromosomes 9, 16, 28, and the W sex chromosome by dual-color fluorescence in situ hybridization using a telomeric sequence probe and BAC clones previously assigned to chicken chromosomes. The in-common features of the mega-telomere chromosomes are that microchromosomes are involved rather than macrochromosomes; in three cases (9, 16, 28) acrocentrics are involved with the mega-telomeres mapping to the p arms. Three of the four chromosomes (9, 16, W) encode tandem repeats which in two cases (9 and 16) involve the ribosomal DNA arrays (the 5S and 18S-5.8S-28S gene repeats, respectively). All involved chromosomes have a typical-sized telomere on the opposite terminus. Intra- and interindividual variation for mega-telomere distribution are discussed in terms of karyotype abnormalities and the potential for mitotic instability of some telomeres. The diversity and distribution of telomere array quantity in the chicken genome should be useful in contributing to research related to telomere length regulation - how and by what mechanism genomes and individual chromosomes establish and maintain distinct sets of telomere array sizes, as well as for future studies related to stability of the chicken genome affecting development, growth, cellular lifespan and disease. An additional impact of this study includes the listing of BAC clones (26 autosomal and six W BACs tested) that were cytogenetically verified; this set of BACs provide a useful tool for future cytogenetic analyses of the microchromosomes. PMID:17675845

  19. Study on semi-active control of mega-sub controlled structure by MR damper subject to random wind loads

    Qin Xiangjun; Zhang Xun'an; Sheldon Cherry

    2008-01-01

    The recently proposed mega-sub controlled structure (MSCS), a new type of structure associated with the design and construction of super-tall buildings, has attracted the attention of designers for use in enhancing the control effectiveness in mega-fi'ame buildings. In this paper, a dynamic equation and method to assemble parameter matrixes for a mega-sub controlled structure under random wind loads is presented. Semi-active control using magnetorheological dampers for the MSCS under random wind loads is investigated, and is compared with a corresponding system without dampers. A parametric study of the relative stiffness ratio and relative mass ratio between the mega-frame and the substructures, as well as the additional column stiffness ratio that influences the response control effectiveness of the MSCS, is discussed. The studies reveal, for the first time, that different control mechanisms exist. The results indicate that the proposed structure employing semi-active control can offer an effective control mechanism. Guidelines for selecting parameters are provided based on the analytical study.

  20. Trend of Scientific Research: Analysis of Mega-Data of Discrete Event Systems Described by Petri Nets and Their Extensions

    Omaima BENATIA

    2016-07-01

    Full Text Available : In this article, we are interested in the discrete event systems modeled by Petri nets and their extensions and we analyze the mega-data of more than one thousand articles published in the last forty years to determine the trend of the scientific research in this domain.

  1. Modelling and evaluating municipal solid waste management strategies in a mega-city: The case of Ho Chi Minh City

    ThiKimOanh, L.; Bloemhof-Ruwaard, J.M.; Buuren, van J.C.L.; Vorst, van der J.G.A.J.; Rulkens, W.H.

    2015-01-01

    Ho Chi Minh City is a large city that will become a mega-city in the near future. The city struggles with a rapidly increasing flow of municipal solid waste and a foreseeable scarcity of land to continue landfilling, the main treatment of municipal solid waste up to now. Therefore, additional munici

  2. Educational Planning and Social Responsibility: Eleven Years of Mega Planning at the Sonora Institute of Technology (ITSON)

    Guerra, Ingrid J.; Rodriguez, Gonzalo

    2005-01-01

    The Instituto Tecnologico de Sonora (ITSON), a public and autonomous university in Cuidad Obregon, Sonora in Mexico has, since its inception, maintained a commitment to society and public service. To transform this commitment into valued results, it has used Mega Planning as its framework over the last eleven years. This article illustrates the…

  3. Conjugative plasmids isolated from bacteria in marine environments show various degrees of homology to each other and are not closely related to well-characterized plasmids.

    Dahlberg, C; Linberg, C; Torsvik, V L; Hermansson, M

    1997-01-01

    Mercury resistance plasmids were exogenously isolated, i.e., recovered after transfer to a model recipient bacterium, from marine air-water interface, bulk water, and biofilm communities during incubation in artificial seawater without added nutrients. Ninety-five plasmids from different environments were classified by restriction endonuclease digestion, and 12 different structural plasmid groups were revealed. The plasmid types isolated from different habitats and from different sampling occ...

  4. Replication of a low-copy-number plasmid by a plasmid DNA-membrane complex extracted from minicells of Escherichia coli.

    Firshein, W; Strumph, P; Benjamin, P; Burnstein, K; Kornacki, J

    1982-01-01

    A DNA-membrane complex was extracted from minicells of an Escherichia coli mutant harboring a "miniplasmid" derivative (11.2 kilobases) of the low-copynumber plasmid RK2 (56 kilobases). The complex contained various species of supercoiled and intermediate forms of plasmid DNA, of which approximately 20% was bound firmly to the membrane after centrifugation in a CsCl density gradient. The plasmid DNA-membrane complex synthesized new plasmid DNA without the addition of exogenous template, enzym...

  5. Plasmids and rickettsial evolution: insight from Rickettsia felis.

    Joseph J Gillespie

    Full Text Available BACKGROUND: The genome sequence of Rickettsia felis revealed a number of rickettsial genetic anomalies that likely contribute not only to a large genome size relative to other rickettsiae, but also to phenotypic oddities that have confounded the categorization of R. felis as either typhus group (TG or spotted fever group (SFG rickettsiae. Most intriguing was the first report from rickettsiae of a conjugative plasmid (pRF that contains 68 putative open reading frames, several of which are predicted to encode proteins with high similarity to conjugative machinery in other plasmid-containing bacteria. METHODOLOGY/PRINCIPAL FINDINGS: Using phylogeny estimation, we determined the mode of inheritance of pRF genes relative to conserved rickettsial chromosomal genes. Phylogenies of chromosomal genes were in agreement with other published rickettsial trees. However, phylogenies including pRF genes yielded different topologies and suggest a close relationship between pRF and ancestral group (AG rickettsiae, including the recently completed genome of R. bellii str. RML369-C. This relatedness is further supported by the distribution of pRF genes across other rickettsiae, as 10 pRF genes (or inactive derivatives also occur in AG (but not SFG rickettsiae, with five of these genes characteristic of typical plasmids. Detailed characterization of pRF genes resulted in two novel findings: the identification of oriV and replication termination regions, and the likelihood that a second proposed plasmid, pRFdelta, is an artifact of the original genome assembly. CONCLUSION/SIGNIFICANCE: Altogether, we propose a new rickettsial classification scheme with the addition of a fourth lineage, transitional group (TRG rickettsiae, that is unique from TG and SFG rickettsiae and harbors genes from possible exchanges with AG rickettsiae via conjugation. We offer insight into the evolution of a plastic plasmid system in rickettsiae, including the role plasmids may have played in

  6. Currents, Water Budget and Turn-Over Time Within A Man-Made Coastal Mega-Structure: Palm Jumeirah, Southern Arabian Gulf, United Arab Emirates

    Cavalcante, G.; Kjerfve, B.

    2009-05-01

    Large-scale land reclamation projects along the coastline of Dubai, United Arab Emirates (UAE), are set to expand from 45 km of natural shoreline to more than 1,500 km by 2010. The increasing scale of coastal development in Dubai has large-scale effects on water movement throughout the project area. Palm Jumeirah is the oldest, most well-developed of several man-made coastal mega-constructions in Dubai. This construction project started 6 years ago, has an overall surface area of 7.9 km2 and a footprint of 23 km2, and is connected to the coast via a 5-km long spine from the mainland to the crescent tip. We made time series observations of hydrographic properties and currents within the Palm Jumeirah Lagoon (PJL) during 29 days in April/May 2008 to examine the current flows, water budget, salt transport, and turn-over time. The currents and water flow within the PJL were quite variable, with stronger currents, greater material transports, lower water temperatures, and slightly lower salinities in areas close to the entrances where flushing is ample. Due to the shallow water depths, we found only weak vertical stratification during a tidal cycle. The lagoon system is comprised of 18 blind channels surrounded by a semi-circular open channel, which in turn is linked to the coastal waters by 4 gaps (one each on the East and West sides and two at the base of the development) in the rocky breakwater that surrounds the development. We found substantial differences in water discharge between the east and west gaps, with high discharge on average exiting the east gap and extremely low water discharge exiting the west gap. Our results indicate that the PJL is flushed unequally between the east and west sides with residence times of 1.2 and 42 days for the east and west sides of the development, respectively. Previous studies of water residence time using the DELFT3D hydrodynamics simulation modeling software did not capture this difference accurately, estimating residence

  7. Mega-city and great earthquake distributions: the search of basic links.

    Levin, Boris; Sasorova, Elena; Domanski, Andrej

    2013-04-01

    The ever-increasing population density in large metropolitan cities near major active faults (e.g. Tokyo, Lisbon, San-Francisco, et al.) and recent catastrophic earthquakes in Japan, Indonesia and Haiti (loss of life more 500000), highlight the need for searching of causal relationships between distributions of earthquake epicenters and mega-cities at the Earth [1]. The latitudinal distribution of mega-cities calculated with using Internet data base, discovers a curious peculiarity: the density of large city numbers, related to 10-degree latitude interval, demonstrates two maximums in middle latitudes (±30-40°) on both sides of the equator. These maximums are separated by clean local minimum near equator, and such objects (mega-cities) are practically absent in the high latitudes. In the last two decades, it was shown [2, 3, 4] that a seismic activity of the Earth is described by the similar bimodal latitudinal distribution. The similarity between bimodal distributions for geophysical phenomena and mega-city locations attracts common attention. The peak values in the both distributions (near ±35°) correspond to location of well-known "critical latitudes" at the planet. These latitudes were determined [5], as the lines of intersection of a sphere and a spheroid of equal volume (±35°15'52″). Increasing of the angular velocity of a celestial body rotation leads to growth of oblateness of planet, and vice versa, the oblateness is decreasing with reducing of velocity of rotation. So, well-known effect of the Earth rotation instability leads to small pulsations of the geoid. In the critical latitudes, the geoid radius-vector is equal to the radius of sphere. The zones of near critical latitudes are characterized by high density of faults in the Earth crust and manifestation of some geological peculiarities (hot spot distribution, large ore deposit distribution, et al.). The active faults existence has led to an emanation of depth fluids, which created the good

  8. X-ray calibration facility for plasma diagnostics of the MegaJoule laser

    The Laser MegaJoule (LMJ) located at CEA-CESTA will be equipped with x-ray plasma diagnostics using different kinds of x-ray components such as filters, mirrors, crystals, detectors and cameras. To guarantee LMJ measurements, detectors such as x-ray cameras need to be regularly calibrated. An x-ray laboratory is devoted to this task and performs absolute x-ray calibrations for similar x-ray cameras running on Laser Integration Line (LIL). This paper presents the x-ray calibration bench with its x-ray tube based High Energy x-ray Source (HEXS) and some calibration results. By mean of an ingenious transposition system under vacuum absolute x-ray calibration of x-ray cameras, like streak and stripline ones, can be carried out. Coupled to a new collimation system with micrometric accuracy on aperture sensitivity quantum efficiency measurements can be achieved with reduced uncertainties. (authors)

  9. Locked on course: Hydro-Quebec's commitment to mega-projects

    Large organizations often escalate their commitments to mega-project development, even after evidence becomes available of adverse environmental consequences or lack of economic feasibility. This escalation of commitment transcends both sectorial and national boundaries. Preeminent examples include controversial nuclear projects in the US, hydroelectric projects like the Three Gorges Dam in China, and transport projects like the Chunnel and the Concorde. In this article, the authors examine the experience of Hydro-Quebec with the Great Whale Project. They argue that Hydro-Quebec escalated its commitment even after serious questions emerged about its environmental impacts and economic feasibility, because of (1) its earlier success with large projects, (2) its engineering culture''s norms for consistency, and (3) its role in the government''s desire for economic and cultural autonomy. Finally, they discuss the changes that are necessary to break commitments to such projects

  10. Meteor observations with Mini-MegaTORTORA wide-field monitoring system

    Karpov, S; Beskin, G; Biryukov, A; Bondar, S; Ivanov, E; Katkova, E; Perkov, A; Sasyuk, V

    2016-01-01

    Here we report on the results of meteor observations with 9-channel Mini-MegaTORTORA (MMT-9) wide-field optical monitoring system with high temporal resolution. During first 1.5 years of operation more than 90 thousands of meteors have been detected, at a rate of 300-350 per night, with durations from 0.1 to 2.5 seconds and angular velocities up to 38 degrees per second. The faintest detected meteors has the peak brightness about 10 mag, while the majority - from 4 to 8 mag. Some of the meteors have been observed in BVR filters simultaneously. Color variations along the trail for them are determined. All parameters of detected meteors are published online. The database also includes the information on 10 thousands meteors detected by our previous FAVOR camera in 2006-2009 years.

  11. Impact of environmental contamination on laser induced damage of silica optics in Laser MegaJoule

    Laser induced damage impact of molecular contamination on fused polished silica samples in a context of high power laser fusion facility, such as Laser MegaJoule (LMJ) has been studied. One of the possible causes of laser induced degradation of optical component is the adsorption of molecular or particular contamination on optical surfaces. In the peculiar case of LMJ, laser irradiation conditions are a fluence of 10 J/cm2, a wavelength of 351 nm, a pulse duration of 3 ns for a single shot/days frequency. Critical compounds have been identified thanks to environmental measurements, analysis of material outgassing, and identification of surface contamination in the critical environments. Experiments of controlled contamination involving these compounds have been conducted in order to understand and model mechanisms of laser damage. Various hypotheses are proposed to explain the damage mechanism. (author)

  12. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

    Weathersby, S. P. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Brown, G. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Centurion, M. [University of Nebraska-Lincoln, 855 N 16th Street, Lincoln, Nebraska 68588, USA; Chase, T. F. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Coffee, R. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Corbett, J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Eichner, J. P. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Frisch, J. C. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Fry, A. R. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Gühr, M. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Hartmann, N. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Hast, C. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Hettel, R. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Jobe, R. K. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Jongewaard, E. N. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Lewandowski, J. R. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Li, R. K. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Lindenberg, A. M. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Makasyuk, I. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; May, J. E. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; McCormick, D. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Nguyen, M. N. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Reid, A. H. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Shen, X. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Sokolowski-Tinten, K. [University of Duisburg-Essen, Lotharstrasse 1, 47048 Duisburg, Germany; Vecchione, T. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Vetter, S. L. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Wu, J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Yang, J. [University of Nebraska-Lincoln, 855 N 16th Street, Lincoln, Nebraska 68588, USA; Dürr, H. A. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Wang, X. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

    2015-07-01

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

  13. Mega Borg oil spill of the Texas coast: An open-water bioremediation test

    Nature has developed hydrocarbons as a part of life. Since the origin of life, more than 60,000 organic molecules have evolved that make up protoplasm; a given percentage of these molecules are hydrocarbons. Commercial hydrocarbon deposits are a by-product of this natural process and a continual source of oil in the aquatic environment through seeps. As a result, nature has also evolved a recycling system for the hydrocarbons. This cycle is the basis for a program of bioremediation using microorganisms. Effort has been made to develop mixed cultures capable of a wide range of hydrocarbon metabolism and co-metabolism. The cultures are economically produced in high concentrations as a dry powder with a shelf life of one year. The result is an economical process for the application of bacteria to hydrocarbon pollutants on water and soils. The process of bioremediation to the recent Mega Borg accident will be discussed

  14. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory

    Weathersby, S. P.; Brown, G.; Chase, T. F.; Coffee, R.; Corbett, J.; Eichner, J. P.; Frisch, J. C.; Fry, A. R.; Gühr, M.; Hartmann, N.; Hast, C.; Hettel, R.; Jobe, R. K.; Jongewaard, E. N.; Lewandowski, J. R.; Li, R. K., E-mail: lrk@slac.stanford.edu; Lindenberg, A. M.; Makasyuk, I.; May, J. E.; McCormick, D. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); and others

    2015-07-15

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability.

  15. Lessons from the Twin Mega-Crises: The Financial Meltdown and the BP Oil Spill

    Hershey H. Friedman

    2014-09-01

    Full Text Available This paper explores the synchronicity of two mega-crises we are now facing: The BP oil spill and the repercussions of the 2008 financial meltdown. It examines some key common threads in both of these crises. The overarching message is that firms must maintain a culture of social responsibility, must behave in an ethical manner, and must do everything possible to avoid societal harm. The three key lessons to be learned from the twin crises are to consider and mange risk in decision making; minimize conflicts of interest in the hope that executives will then not engage in actions that involve excessive risk to stakeholders; and that government regulation can be beneficial, rather than harmful to business and society – as long as it does not stifle innovation and growth.

  16. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory.

    Weathersby, S P; Brown, G; Centurion, M; Chase, T F; Coffee, R; Corbett, J; Eichner, J P; Frisch, J C; Fry, A R; Gühr, M; Hartmann, N; Hast, C; Hettel, R; Jobe, R K; Jongewaard, E N; Lewandowski, J R; Li, R K; Lindenberg, A M; Makasyuk, I; May, J E; McCormick, D; Nguyen, M N; Reid, A H; Shen, X; Sokolowski-Tinten, K; Vecchione, T; Vetter, S L; Wu, J; Yang, J; Dürr, H A; Wang, X J

    2015-07-01

    Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate with outstanding performance. In this paper, we report on the SLAC MeV UED system and its performance, including the reciprocal space resolution, temporal resolution, and machine stability. PMID:26233391

  17. Microbiota do megaesôfago e carcinogênese Megaesophagus microbiota and carcinogenesis

    Denis Pajecki; Bruno Zilberstein; Manoel Armando Azevedo dos Santos; Alina Guimarães Quintanilha; Ivan Cecconello; Joaquim Gama-Rodrigues

    2003-01-01

    INTRODUÇÃO: O risco de desenvolvimento de carcinoma esofágico em portadores de megaesôfago é 33 vezes superior ao da população em geral. Possível explicação para este fenômeno poderia estar relacionada à produção de compostos N-nitrosos na luz do órgão, a partir da transformação de nitratos da dieta em nitritos, mediada por bactérias em suspensão no líquido de estase e com o contato crônico destes carcinógenos com a mucosa esofágica. OBJETIVO: Analisar a microbiota esofágica em pacientes port...

  18. Calculation of prompt doses induced by fusion experiments in Laser MegaJoule facility

    Baggio, Jacques, E-mail: jacques.baggio@projet-lmj.org [CEA/CESTA BP2 33114 Le Barp (France); Jacquet, Henri-Patrick [CEA/DIF, Bruyeres Le Chatel 91297 Arpajon Cedex (France); Schneider, Philippe; Javier, Francois [CEA/CESTA BP2 33114 Le Barp (France)

    2011-10-15

    The Laser MegaJoule (LMJ), built at CEA/CESTA near Bordeaux, France, will conduct research in the field of plasma physics and inertial confinement fusion. Some of these experiments are designed to produce during less than one nanosecond up to 10{sup 19} neutrons at 14 MeV in indirect drive mode. The 300 m long building that hosts both laser sources and target chamber was designed to confine neutron and gamma fluxes in the experiment hall during a shot. Monte Carlo simulations were performed using a TRIPOLI 4 modelling of the facility to ensure that prompt doses in occupied areas inside the facility that host employees during a shot will be sufficiently low. Although significant radiation levels inside the experiment hall, prompt doses in occupied rooms are limited to a few {mu}Sv per shot which is fully compatible with radiation level limits.

  19. Vulnerability of optical detection systems to mega-joule class laser radiative environment

    The Laser MegaJoule (LMJ) facility will host inertial confinement fusion experiments in order to achieve ignition by imploding a Deuterium-Tritium filled micro balloon. In this context an X-ray imaging system is necessary to diagnose the core size and the shape of the target in the 10-100 keV band. Such a diagnostic will be composed of two parts: an X-ray optical system and a detection assembly. The survivability of each element of this diagnostic has to be ensured within the mixed pulse consisting of X-rays, gamma rays and 14 MeV neutrons created by fusion reactions. The design of this diagnostic will take into account optics and detectors vulnerability to neutron yield of at least 1016. In this work, we will present the main results of our vulnerability studies and of our hardening-by-system and hardening-by-design studies. (authors)

  20. Overview of the ARGOS X-ray framing camera for Laser MegaJoule

    Trosseille, C., E-mail: clement.trosseille@cea.fr; Aubert, D.; Auger, L.; Bazzoli, S.; Brunel, P.; Burillo, M.; Chollet, C.; Jasmin, S.; Maruenda, P.; Moreau, I.; Oudot, G.; Raimbourg, J.; Soullié, G.; Stemmler, P.; Zuber, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Beck, T. [CEA, DEN, CADARACHE, F-13108 St Paul lez Durance (France); Gazave, J. [CEA, DAM, CESTA, F-33116 Le Barp (France)

    2014-11-15

    Commissariat à l’Énergie Atomique et aux Énergies Alternatives has developed the ARGOS X-ray framing camera to perform two-dimensional, high-timing resolution imaging of an imploding target on the French high-power laser facility Laser MegaJoule. The main features of this camera are: a microchannel plate gated X-ray detector, a spring-loaded CCD camera that maintains proximity focus in any orientation, and electronics packages that provide remotely-selectable high-voltages to modify the exposure-time of the camera. These components are integrated into an “air-box” that protects them from the harsh environmental conditions. A miniaturized X-ray generator is also part of the device for in situ self-testing purposes.

  1. Characterizing Mega-Earthquake Related Tsunami on Subduction Zones without Large Historical Events

    Williams, C. R.; Lee, R.; Astill, S.; Farahani, R.; Wilson, P. S.; Mohammed, F.

    2014-12-01

    Due to recent large tsunami events (e.g., Chile 2010 and Japan 2011), the insurance industry is very aware of the importance of managing its exposure to tsunami risk. There are currently few tools available to help establish policies for managing and pricing tsunami risk globally. As a starting point and to help address this issue, Risk Management Solutions Inc. (RMS) is developing a global suite of tsunami inundation footprints. This dataset will include both representations of historical events as well as a series of M9 scenarios on subductions zones that have not historical generated mega earthquakes. The latter set is included to address concerns about the completeness of the historical record for mega earthquakes. This concern stems from the fact that the Tohoku Japan earthquake was considerably larger than had been observed in the historical record. Characterizing the source and rupture pattern for the subduction zones without historical events is a poorly constrained process. In many case, the subduction zones can be segmented based on changes in the characteristics of the subducting slab or major ridge systems. For this project, the unit sources from the NOAA propagation database are utilized to leverage the basin wide modeling included in this dataset. The length of the rupture is characterized based on subduction zone segmentation and the slip per unit source can be determined based on the event magnitude (i.e., M9) and moment balancing. As these events have not occurred historically, there is little to constrain the slip distribution. Sensitivity tests on the potential rupture pattern have been undertaken comparing uniform slip to higher shallow slip and tapered slip models. Subduction zones examined include the Makran Trench, the Lesser Antilles and the Hikurangi Trench. The ultimate goal is to create a series of tsunami footprints to help insurers understand their exposures at risk to tsunami inundation around the world.

  2. Predictors of Success in an Anesthesiology Residency.

    Warrick, Shirley S.; Crumrine, Robert S.

    1986-01-01

    Factors that contributed to successful residency performance by anesthesiology residents were examined in order to assist the program's selection committee in developing selection criteria. The best predictor of a resident's academic average in the anethesiology program was the number of years the resident had spent in other specialities.…

  3. Feasibility of an innovative third-year chief resident system: an internal medicine residency leadership study

    Kolade, Victor O; Staton, Lisa J.; Jayarajan, Ramesh; Bentley, Nanette K.; Huang, Xiangke

    2014-01-01

    Introduction: The role of the internal medicine chief resident includes various administrative, academic, social, and educational responsibilities, fulfillment of which prepares residents for further leadership tasks. However, the chief resident position has historically only been held by a few residents. As fourth-year chief residents are becoming less common, we considered a new model for rotating third-year residents as the chief resident.Methods: Online surveys were given to all 29 intern...

  4. Plasma-activated air mediates plasmid DNA delivery in vivo.

    Edelblute, Chelsea M; Heller, Loree C; Malik, Muhammad A; Bulysheva, Anna; Heller, Richard

    2016-01-01

    Plasma-activated air (PAA) provides a noncontact DNA transfer platform. In the current study, PAA was used for the delivery of plasmid DNA in a 3D human skin model, as well as in vivo. Delivery of plasmid DNA encoding luciferase to recellularized dermal constructs was enhanced, resulting in a fourfold increase in luciferase expression over 120 hours compared to injection only (P plasmid DNA encoding green fluorescent protein (GFP) was confirmed in the epidermal layers of the construct. In vivo experiments were performed in BALB/c mice, with skin as the delivery target. PAA exposure significantly enhanced luciferase expression levels 460-fold in exposed sites compared to levels obtained from the injection of plasmid DNA alone (P plasmid DNA encoding GFP to mouse skin was confirmed by immunostaining, where a 3-minute exposure at a 10 mm distance displayed delivery distribution deep within the dermal layers compared to an exposure at 3 mm where GFP expression was localized within the epidermis. Our findings suggest PAA-mediated delivery warrants further exploration as an alternative approach for DNA transfer for skin targets. PMID:27110584

  5. Replicase-based plasmid DNA shows anti-tumor activity

    Weiss Richard

    2011-03-01

    Full Text Available Abstract Background Double stranded RNA (dsRNA has multiple anti-tumor mechanisms. Over the past several decades, there have been numerous attempts to utilize synthetic dsRNA to control tumor growth in animal models and clinical trials. Recently, it became clear that intracellular dsRNA is more effective than extracellular dsRNA on promoting apoptosis and orchestrating adaptive immune responses. To overcome the difficulty in delivering a large dose of synthetic dsRNA into tumors, we propose to deliver a RNA replicase-based plasmid DNA, hypothesizing that the dsRNA generated by the replicase-based plasmid in tumor cells will inhibit tumor growth. Methods The anti-tumor activity of a plasmid (pSIN-β that encodes the sindbis RNA replicase genes (nsp1-4 was evaluated in mice with model tumors (TC-1 lung cancer cells or B16 melanoma cells and compared to a traditional pCMV-β plasmid. Results In cell culture, transfection of tumor cells with pSIN-β generated dsRNA. In mice with model tumors, pSIN-β more effectively delayed tumor growth than pCMV-β, and in some cases, eradicated the tumors. Conclusion RNA replicase-based plasmid may be exploited to generate intracellular dsRNA to control tumor growth.

  6. Replicase-based plasmid DNA shows anti-tumor activity

    Double stranded RNA (dsRNA) has multiple anti-tumor mechanisms. Over the past several decades, there have been numerous attempts to utilize synthetic dsRNA to control tumor growth in animal models and clinical trials. Recently, it became clear that intracellular dsRNA is more effective than extracellular dsRNA on promoting apoptosis and orchestrating adaptive immune responses. To overcome the difficulty in delivering a large dose of synthetic dsRNA into tumors, we propose to deliver a RNA replicase-based plasmid DNA, hypothesizing that the dsRNA generated by the replicase-based plasmid in tumor cells will inhibit tumor growth. The anti-tumor activity of a plasmid (pSIN-β) that encodes the sindbis RNA replicase genes (nsp1-4) was evaluated in mice with model tumors (TC-1 lung cancer cells or B16 melanoma cells) and compared to a traditional pCMV-β plasmid. In cell culture, transfection of tumor cells with pSIN-β generated dsRNA. In mice with model tumors, pSIN-β more effectively delayed tumor growth than pCMV-β, and in some cases, eradicated the tumors. RNA replicase-based plasmid may be exploited to generate intracellular dsRNA to control tumor growth

  7. Functional amyloids as inhibitors of plasmid DNA replication.

    Molina-García, Laura; Gasset-Rosa, Fátima; Moreno-Del Álamo, María; Fernández-Tresguerres, M Elena; Moreno-Díaz de la Espina, Susana; Lurz, Rudi; Giraldo, Rafael

    2016-01-01

    DNA replication is tightly regulated to constrain the genetic material within strict spatiotemporal boundaries and copy numbers. Bacterial plasmids are autonomously replicating DNA molecules of much clinical, environmental and biotechnological interest. A mechanism used by plasmids to prevent over-replication is 'handcuffing', i.e. inactivating the replication origins in two DNA molecules by holding them together through a bridge built by a plasmid-encoded initiator protein (Rep). Besides being involved in handcuffing, the WH1 domain in the RepA protein assembles as amyloid fibres upon binding to DNA in vitro. The amyloid state in proteins is linked to specific human diseases, but determines selectable and epigenetically transmissible phenotypes in microorganisms. Here we have explored the connection between handcuffing and amyloidogenesis of full-length RepA. Using a monoclonal antibody specific for an amyloidogenic conformation of RepA-WH1, we have found that the handcuffed RepA assemblies, either reconstructed in vitro or in plasmids clustering at the bacterial nucleoid, are amyloidogenic. The replication-inhibitory RepA handcuff assembly is, to our knowledge, the first protein amyloid directly dealing with DNA. Built on an amyloid scaffold, bacterial plasmid handcuffs can bring a novel molecular solution to the universal problem of keeping control on DNA replication initiation. PMID:27147472

  8. Dcm methylation is detrimental to plasmid transformation in Clostridium thermocellum

    Guss, Adam M [ORNL; Olson, Daniel G. [Thayer School of Engineering at Dartmouth; Caiazza, Nicky [Mascoma Corporation; Lynd, Lee R [Thayer School of Engineering at Dartmouth

    2012-01-01

    BACKGROUND: Industrial production of biofuels and other products by cellulolytic microorganisms is of interest but hindered by the nascent state of genetic tools. Although a genetic system for Clostridium thermocellum DSM1313 has recently been developed, available methods achieve relatively low efficiency and similar plasmids can transform C. thermocellum at dramatically different efficiencies. RESULTS: We report an increase in transformation efficiency of C. thermocellum for a variety of plasmids by using DNA that has been methylated by Escherichia coli Dam but not Dcm methylases. When isolated from a dam+ dcm+ E. coli strain, pAMG206 transforms C. thermocellum 100-fold better than the similar plasmid pAMG205, which contains an additional Dcm methylation site in the pyrF gene. Upon removal of Dcm methylation, transformation with pAMG206 showed a four- to seven-fold increase in efficiency; however, transformation efficiency of pAMG205 increased 500-fold. Removal of the Dcm methylation site from the pAM205 pyrF gene via silent mutation resulted in increased transformation efficiencies equivalent to that of pAMG206. Upon proper methylation, transformation efficiency of plasmids bearing the pMK3 and pB6A origins of replication increased ca. three orders of magnitude. CONCLUSION: E. coli Dcm methylation decreases transformation efficiency in C. thermocellum DSM1313. The use of properly methylated plasmid DNA should facilitate genetic manipulation of this industrially relevant bacterium.

  9. The Emotional Intelligence of Resident Physicians

    McKinley, Sophia Kim

    2014-01-01

    Since academic literature indicates that emotional intelligence (EI) is tied to work performance, there is increasing interest in understanding physician EI. We studied the EI of resident physicians in surgery, pediatric, and pathology residency programs at three academic centers to describe the EI profiles of residents in different specialties and determine whether gender differences in resident physician EI profiles mirror those in the general population. 325 residents were electronically...

  10. Air-quality measurements in mega-cities: Focus on gaseous organic and particulate pollutants and comparison between two contrasted cities, Paris and Beijing

    The rapid and important development of large urban areas ('mega-cities'), especially in developing countries, causes and will cause serious air-quality problems. Pollutant measurements in these cities help to characterize the chemical nature and the quantity of these pollutants and to constrain air-quality models. This paper focuses on measurements of volatile organic compounds and aerosols that have an important impact on air quality. We present a brief review on existing measurements and experimental strategies in mega-cities and then we show results from recent measurement campaigns that took place in two contrasted mega-cities: Paris and Beijing. (authors)

  11. Mitochondrial pAL2-1 plasmid homologs are senescence factors in Podospora anserina independent of intrinsic senescence

    van Diepeningen, Anne D; Debets, Alfons J M; Slakhorst, S Marijke; Hoekstra, Rolf F

    2008-01-01

    Since the first description of a linear mitochondrial plasmid in Podospora anserina, pAL2-1, and homologous plasmids have gone from being considered beneficial longevity plasmids, via neutral genetic elements, toward mutator plasmids causing senescence. The plasmid has an invertron structure, with t

  12. Resilience Approach for Medical Residents

    Bezemer, R.A.; Bos, E.W.

    2014-01-01

    Medical residents are in a vulnerable position. While still in training, they are responsible for patient care. They have a dependent relation with their supervisor and low decision latitude. An intervention was developed to increase individual and system resilience, addressing burnout, patient safe

  13. Evolution of genes on the Salmonella Virulence plasmid phylogeny revealed from sequencing of the virulence plasmids of S. enterica serotype Dublin and comparative analysis.

    Chu, Chishih; Feng, Ye; Chien, An-Chi; Hu, Songnian; Chu, Chi-Hong; Chiu, Cheng-Hsun

    2008-11-01

    Salmonella enterica serotype Dublin harbors an approximately 80-kb virulence plasmid (pSDV), which mediates systemic infection in cattle. There are two types of pSDV: one is pSDVu (pOU1113) in strain OU7025 and the other pSDVr (pOU1115) in OU7409 (SD Lane) and many clinical isolates. Sequence analysis showed that pSDVr was a recombinant plasmid (co-integrate) of pSDVu and a plasmid similar to a 35-kb indigenous plasmid (pOU1114) of S. Dublin. Most of the F-transfer region in pSDVu was replaced by a DNA segment from the pOU1114-like plasmid containing an extra replicon and a pilX operon encoding for a type IV secretion system to form pSDVr. We reconstructed the particular evolutionary history of the seven virulence plasmids of Salmonella by comparative sequence analysis. The whole evolutionary process might begin with two different F-like plasmids (IncFI and IncFII), which then incorporated the spv operon and fimbriae operon from the chromosome to form the primitive virulence plasmids. Subsequently, these plasmids descended by deletion from a relatively large plasmid to smaller ones, with some recombination events occurring over time. Our results suggest that the phylogeny of virulence plasmids as a result of frequent recombination provides the opportunity for rapid evolution of Salmonella in response to the environmental cues. PMID:18718522

  14. Recombinogenic engineering of conjugative plasmids with fluorescent marker cassettes

    Reisner, A.; Molin, Søren; Zechner, E.L.

    2002-01-01

    An efficient approach for the insertion of fluorescent marker genes with sequence specificity into conjugative plasmids in Escherichia coli is described. For this purpose, homologous recombination of linear double-stranded targeting DNA was mediated by the bacteriophage lambda recombination...... functions using very short regions of homology. Initial manipulation of the IncFII target plasmids R1 and R1drd19 indicated that the linear targeting DNA should be devoid of all extraneous homologies to. the target molecule for optimal insertion specificity. Indeed, a simple recombination assay proved...... resistance genes and fluorescent markers. The choice of 5' non-homologous extensions in primer pairs used for amplifying the marker cassettes determines the site specificity of the targeting DNA. This methodology is applicable to the modification of all plasmids that replicate in E coli and is not restricted...

  15. A novel plasmid pEA68 of Erwinia amylovora and the description of a new family of plasmids.

    Ismail, Emadeldeen; Blom, Jochen; Bultreys, Alain; Ivanović, Milan; Obradović, Aleksa; van Doorn, Joop; Bergsma-Vlami, Maria; Maes, Martine; Willems, Anne; Duffy, Brion; Stockwell, Virginia O; Smits, Theo H M; Puławska, Joanna

    2014-12-01

    Recent genome analysis of Erwinia amylovora, the causal agent of fire blight disease on Rosaceae, has shown that the chromosome is highly conserved among strains and that plasmids are the principal source of genomic diversity. A new circular plasmid, pEA68, was found in E. amylovora strain 692 (LMG 28361), isolated in Poland from Sorbus (mountain ash) with fire blight symptoms. Annotation of the 68,763-bp IncFIIa-type plasmid revealed that it contains 79 predicted CDS, among which two operons (tra, pil) are associated with mobility. The plasmid is maintained stably in E. amylovora and does not possess genes associated with antibiotic resistance or known virulence genes. Curing E. amylovora strain 692 of pEA68 did not influence its virulence in apple shoots nor amylovoran synthesis. Of 488 strains of E. amylovora from seventeen countries, pEA68 was only found in two additional strains from Belgium. Although the spread of pEA68 is currently limited to Europe, pEA68 comprises, together with pEA72 and pEA78 both found in North America, a new plasmid family that spans two continents. PMID:25178659

  16. Characterization of atypical Aeromonas salmonicida isolates by ribotyping and plasmid profiling

    Pedersen, Karl; Dalsgaard, Inger; Larsen, J.L.

    1996-01-01

    ) and plasmid profiles. Most epidemiologically unrelated strains had different ribotypes, whereas isolates from the same outbreak were identical. All strains, except one, carried one or more large plasmids (>55 kbp) and all strains, except two, additionally carried one or more smaller plasmids. Many strains...... isolated from the same outbreak showed different plasmid profiles although some plasmids were identical. The results suggest the existence of several atypical Aer, salmonicida. It also seems that ribotypes are stable properties for these bacteria while the plasmids are more labile....

  17. Anion exchange purification of plasmid DNA using expanded bed adsorption.

    Ferreira, G N; Cabral, J M; Prazeres, D M

    2000-01-01

    Recent developments in gene therapy with non-viral vectors and DNA vaccination have increased the demand for large amounts of pharmaceutical-grade plasmid DNA. The high viscosity of process streams is of major concern in the purification of plasmids, since it can cause high back pressures in column operations, thus limiting the throughput. In order to avoid these high back pressures, expanded bed anion exchange chromatography was evaluated as an alternative to fixed bed chromatography. A Streamline 25 column filled with 100 ml of Streamline QXL media, was equilibrated with 0.5 M NaCl in TE (10 mM Tris, 1 mM EDTA, pH = 8.0) buffer at an upward flow of 300 cmh-1, E. coli lysates (obtained from up to 3 liters of fermentation broth) were injected in the column. After washing out the unbound material, the media was allowed to sediment and the plasmid was eluted with 1 M NaCl in TE buffer at a downward flow of 120 cmh-1. Purification factors of 36 +/- 1 fold, 26 +/- 0.4 plasmid purity, and close to 100% yields were obtained when less than one settled column volume of plasmid feed was injected. However, both recovery yield and purity abruptly decreased when larger amounts were processed-values of 35 +/- 2 and 5 +/- 0.7 were obtained for the recovery yield and purity, respectively, when 250 ml of feedstock were processed. In these cases, gel clogging and expansion collapse were observed. The processing of larger volumes, thus larger plasmid quantities, was only possible by performing an isopropanol precipitation step prior to the chromatographic step. This step led to an enhancement of the purification step. PMID:10840595

  18. Short-lived tectonic switch mechanism for long-term pulses of volcanic activity after mega-thrust earthquakes

    M. Lupi

    2013-06-01

    Full Text Available Eruptive rates in volcanic arcs increase significantly after mega-thrust earthquakes in subduction zones. Over short to intermediate time periods the link between mega-thrust earthquakes and arc response can be attributed to dynamic triggering processes or static stress changes, but a fundamental mechanism that controls long-term pulses of volcanic activity after mega-thrust earthquakes has not been proposed yet. Using geomechanical, geological, and geophysical arguments, we propose that increased eruption rates over longer timescales are due to the relaxation of the compressional regime that accompanies mega-thrust subduction zone earthquakes. More specifically, the reduction of the horizontal stress σh promotes the occurrence of short-lived strike-slip kinematics rather than reverse faulting in the volcanic arc. The relaxation of the pre-earthquake compressional regime facilitates magma mobilization by providing a short-circuit pathway to shallow depths by significantly increasing the hydraulic properties of the system. The timescale for the onset of strike-slip faulting depends on the degree of shear stress accumulated in the arc during inter-seismic periods, which in turn is connected to the degree of strain-partitioning at convergent margins. We performed Coulomb stress transfer analysis to determine the order of magnitude of the stress perturbations in present-day volcanic arcs in response to five actual mega-thrust earthquakes; the 2005 M8.6, 2007 M8.5, and 2007 M7.9 Sumatra earthquakes; the 2010 M8.8 Maule, Chile earthquake; and the 2011 M9.0 Tohoku, Japan earthquake. We find that all, but one, the shallow earthquakes that occurred in the arcs of Sumatra, Chile and Japan show a marked lateral component. Our hypothesis suggests that the long-term response of volcanic arcs to subduction zone mega-thrust earthquakes will be manifested as predominantly strike-slip seismic events, and that these future earthquakes will be followed closely by

  19. Effect of Doximity Residency Rankings on Residency Applicants’ Program Choices

    Aimee M. Rolston

    2015-11-01

    Full Text Available Introduction: Choosing a residency program is a stressful and important decision. Doximity released residency program rankings by specialty in September 2014. This study sought to investigate the impact of those rankings on residency application choices made by fourth year medical students. Methods: A 12-item survey was administered in October 2014 to fourth year medical students at three schools. Students indicated their specialty, awareness of and perceived accuracy of the rankings, and the rankings’ impact on the programs to which they chose to apply. Descriptive statistics were reported for all students and those applying to Emergency Medicine (EM. Results: A total of 461 (75.8% students responded, with 425 applying in one of the 20 Doximity ranked specialties. Of the 425, 247 (58% were aware of the rankings and 177 looked at them. On a 1-100 scale (100=very accurate, students reported a mean ranking accuracy rating of 56.7 (SD 20.3. Forty-five percent of students who looked at the rankings modified the number of programs to which they applied. The majority added programs. Of the 47 students applying to EM, 18 looked at the rankings and 33% changed their application list with most adding programs. Conclusion: The Doximity rankings had real effects on students applying to residencies as almost half of students who looked at the rankings modified their program list. Additionally, students found the rankings to be moderately accurate. Graduating students might benefit from emphasis on more objective characterization of programs to assess in light of their own interests and personal/career goals

  20. Sustained plasmid DNA release from dissolving mineral coatings

    Choi, Siyoung; Murphy, William L.

    2010-01-01

    Calcium phosphate (Ca-P) minerals such as hydroxyapatite are able to bind a diverse range of biological molecules due to the presence of anions and cations in their crystal structure. The well-characterized ability of Ca-P minerals to bind and release plasmid DNA, coupled with the ability of biodegradable Ca-P coatings to form on the surface of common biomaterials, provides a potential mechanism for controlled release of plasmid DNA from various biomaterials. In this study we hypothesized tha...

  1. Restriction Fragment Length Polymorphisms of Virulence Plasmids in Rhodococcus equi

    Takai, Shinji; Shoda, Masato; Sasaki, Yukako; Tsubaki, Shiro; Fortier, Guillaume; Pronost, Stephane; Rahal, Karim; Becu, Teotimo; Begg, Angela; Browning, Glenn; Nicholson, Vivian M.; Prescott, John F.

    1999-01-01

    Virulent Rhodococcus equi, which is a well-known cause of pyogranulomatous pneumonia in foals, possesses a large plasmid encoding virulence-associated 15- to 17-kDa antigens. Foal and soil isolates from five countries—Argentina, Australia, Canada, France, and Japan—were investigated for the presence of 15- to 17-kDa antigens by colony blotting, using the monoclonal antibody 10G5, and the gene coding for 15- to 17-kDa antigens by PCR. Plasmid DNAs extracted from positive isolates were digested...

  2. DNA sequence analysis of plasmids from multidrug resistant Salmonella enterica serotype Heidelberg isolates.

    Jing Han

    Full Text Available Salmonella enterica serovar Heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. Salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. To identify plasmid-associated genes in multidrug resistant S. enterica serovar Heidelberg, antimicrobial resistance plasmids from five isolates were sequenced using the 454 LifeSciences pyrosequencing technology. Four of the isolates contained incompatibility group (Inc A/C multidrug resistance plasmids harboring at least eight antimicrobial resistance genes. Each of these strains also carried a second resistance plasmid including two IncFIB, an IncHI2 and a plasmid lacking an identified Inc group. The fifth isolate contained an IncI1 plasmid, encoding resistance to gentamicin, streptomycin and sulfonamides. Some of the IncA/C plasmids lacked the full concert of transfer genes and yet were able to be conjugally transferred, likely due to the transfer genes carried on the companion plasmids in the strains. Several non-IncA/C resistance plasmids also carried putative virulence genes. When the sequences were compared to previously sequenced plasmids, it was found that while all plasmids demonstrated some similarity to other plasmids, they were unique, often due to differences in mobile genetic elements in the plasmids. Our study suggests that Salmonella Heidelberg isolates harbor plasmids that co-select for antimicrobial resistance and virulence, along with genes that can mediate the transfer of plasmids within and among other bacterial isolates. Prevalence of such plasmids can complicate efforts to control the spread of S. enterica serovar Heidelberg in food animal and human populations.

  3. Genetic Characterization of ExPEC-Like Virulence Plasmids among a Subset of NMEC.

    Nicholson, Bryon A; West, Aaron C; Mangiamele, Paul; Barbieri, Nicolle; Wannemuehler, Yvonne; Nolan, Lisa K; Logue, Catherine M; Li, Ganwu

    2016-01-01

    Neonatal Meningitis Escherichia coli (NMEC) is one of the most common causes of neonatal bacterial meningitis in the US and elsewhere resulting in mortality or neurologic deficits in survivors. Large plasmids have been shown experimentally to increase the virulence of NMEC in the rat model of neonatal meningitis. Here, 9 ExPEC-like plasmids were isolated from NMEC and sequenced to identify the core and accessory plasmid genes of ExPEC-like virulence plasmids in NMEC and create an expanded plasmid phylogeny. Results showed sequenced virulence plasmids carry a strongly conserved core of genes with predicted functions in five distinct categories including: virulence, metabolism, plasmid stability, mobile elements, and unknown genes. The major functions of virulence-associated and plasmid core genes serve to increase in vivo fitness by adding multiple iron uptake systems to the genetic repertoire to facilitate NMEC's survival in the host's low iron environment, and systems to enhance bacterial resistance to host innate immunity. Phylogenetic analysis based on these core plasmid genes showed that at least two lineages of ExPEC-like plasmids could be discerned. Further, virulence plasmids from Avian Pathogenic E. coli and NMEC plasmids could not be differentiated based solely on the genes of the core plasmid genome. PMID:26800268

  4. Genetic Characterization of ExPEC-Like Virulence Plasmids among a Subset of NMEC.

    Bryon A Nicholson

    Full Text Available Neonatal Meningitis Escherichia coli (NMEC is one of the most common causes of neonatal bacterial meningitis in the US and elsewhere resulting in mortality or neurologic deficits in survivors. Large plasmids have been shown experimentally to increase the virulence of NMEC in the rat model of neonatal meningitis. Here, 9 ExPEC-like plasmids were isolated from NMEC and sequenced to identify the core and accessory plasmid genes of ExPEC-like virulence plasmids in NMEC and create an expanded plasmid phylogeny. Results showed sequenced virulence plasmids carry a strongly conserved core of genes with predicted functions in five distinct categories including: virulence, metabolism, plasmid stability, mobile elements, and unknown genes. The major functions of virulence-associated and plasmid core genes serve to increase in vivo fitness by adding multiple iron uptake systems to the genetic repertoire to facilitate NMEC's survival in the host's low iron environment, and systems to enhance bacterial resistance to host innate immunity. Phylogenetic analysis based on these core plasmid genes showed that at least two lineages of ExPEC-like plasmids could be discerned. Further, virulence plasmids from Avian Pathogenic E. coli and NMEC plasmids could not be differentiated based solely on the genes of the core plasmid genome.

  5. Novel DC ring topology and protection system - a comprehensive solution for mega city power grids

    Haj-Maharsi, Mohamed Yassine

    2009-07-01

    The development of mega cities leads to increased load concentration and brings additional challenges to managing the electrical grid while keeping power available for critical loads. Techniques using FACTS devices are being applied to alleviate power management difficulties and to confine faults in their originating areas in order to limit the risk of cascading failures in the grid. The addition of many FACTS devices often results in control and protection coordination difficulties, power oscillations between connected networks, subsynchronous resonance problems, and torsional interactions with nearby generator units. The most effective solution is obtained when the individual AC subsystems representing sources and loads are decoupled so a fault in a given subsystem is not propagated to another subsystem. This solution can be achieved by the deployment of a DC system where power sources and loads are connected to the DC bus through voltage source converters. For a mega city, this would be conceived as a DC ring feeding multiple loads and connected to remote and local power sources. Unfortunately, the lack of fast DC circuit breakers has been one of the key issues affecting extensive applications of DC systems with common DC buses; a DC fault would discharge all the capacitors of the DC bus and cause delays in system recovery and possibly a wide system collapse. In this research, I provide a comprehensive solution to mega city power grid problems by proposing a DC system topology that enables grid expansions without affecting existing protection settings or changing existing AC breaker ratings. I also propose the means for protecting the DC system by designing a fast DC breaker and developing a control algorithm capable of isolating DC faults without blocking converter stations or depleting DC bus capacitors. My contribution is three folds: (1) I modeled and simulated Shanghai power grid and performed a study to identify short circuit and voltage stability problems

  6. Tracking aeolian transport patterns across a mega-nourishment using video imagery

    Wijnberg, Kathelijne; van der Weerd, Lianne; Hulscher, Suzanne

    2014-05-01

    Coastal dune areas protect the hinterland from flooding. In order to maintain the safety level provided by the dunes, it may be necessary to artificially supply the beach-dune system with sand. How to best design these shore nourishments, amongst others with respect to optimal dune growth on the long-term (decadal scale), is not yet clear. One reason for this is that current models for aeolian transport on beaches appear to have limited predictive capabilities regarding annual onshore sediment supply. These limited capabilities may be attributed to the lack of appropriate input data, for instance on moisture content of the beach surface, or shortcomings in process understanding. However, it may also be argued that for the long-term prediction of onshore aeolian sand supply from the beach to the dunes, we may need to develop some aggregated-scale transport equations, because the detailed input data required for the application of process-scale transport equations may never be available in reality. A first step towards the development of such new concepts for aggregated-scale transport equations is to increase phenomenological insight into the characteristics and number of aeolian transport events that account for the annual volume changes of the foredunes. This requires high-frequency, long-term data sets to capture the only intermittently occurring aeolian transport events. Automated video image collection seems a promising way to collect such data. In the present study we describe the movement (direction and speed) of sand patches and aeolian bed forms across a nourished site, using video imagery, to characterize aeolian transport pathways and their variability in time. The study site is a mega-nourishment (21 Mm3 of sand) that was recently constructed at the Dutch coast. This mega-nourishment, also referred to as the Sand Motor, is a pilot project that may potentially replace current practice of more frequently applying small scale nourishments. The mega

  7. Redesigning journal club in residency

    Al Achkar, Morhaf

    2016-01-01

    The gap between production and implementation of knowledge is the main reason for the suboptimal quality of health care. To eliminate this gap and improve the quality of patient care, journal club (JC) in graduate medical education provides an opportunity for learning the skills of evidence-based medicine. JC, however, continues to face many challenges mainly due to poorly defined goals, inadequate preparation, and lack of interest. This article presents an innovative model to prepare and present JC based on three pillars: dialogical learning through group discussion, mentored residents as peer teachers, and including JC as part of a structured curriculum to learn evidence-based medicine. This engaging model has the potential to transform JC from a moribund session that is daunting for residents into a lively discussion to redefine clinical practice using the most current evidence.

  8. Redesigning journal club in residency.

    Al Achkar, Morhaf

    2016-01-01

    The gap between production and implementation of knowledge is the main reason for the suboptimal quality of health care. To eliminate this gap and improve the quality of patient care, journal club (JC) in graduate medical education provides an opportunity for learning the skills of evidence-based medicine. JC, however, continues to face many challenges mainly due to poorly defined goals, inadequate preparation, and lack of interest. This article presents an innovative model to prepare and present JC based on three pillars: dialogical learning through group discussion, mentored residents as peer teachers, and including JC as part of a structured curriculum to learn evidence-based medicine. This engaging model has the potential to transform JC from a moribund session that is daunting for residents into a lively discussion to redefine clinical practice using the most current evidence. PMID:27313486

  9. Family Medicine: A Resident's Perspective

    Kumar, Bipin

    2012-01-01

    Though family medicine has existed as a qualification for more than a decade in India, structured residency based training is a recent phenomenon. A growing number of young physicians are opting for this challenging and exciting new speciality as post graduate qualification through NBE (National Board of Examination) affiliated three year DNB (Diplomate of National Board) training program. MD family medicine is also in offing as Medical Council of India (MCI) has recently notified curriculum ...

  10. Governing mega-events: tools of security risk management for the London 2012 Olympic Games and FIFA 2006 World Cup in Germany

    Jennings, Will; Lodge, Martin

    2011-01-01

    Mega-events present a special venue for the practice of risk management. This article analyses the management of security risks in the case of two sporting mega-events, the London 2012 Olympic Games and the FIFA 2006 World Cup in Germany. To what extent do strategies and practices of risk management resemble each other across events? And what explains similarities or differences in the tools of risk management observed in each of these cases? First, this article explores three theoretical exp...

  11. Aerosol optical properties in a rural environment near the mega-city Guangzhou, China: implications for regional air pollution, radiative forcing and remote sensing

    Zhang, Y. H.; L. M. Zeng; M. Shao; Hu, M.; Kondo, Y.; Miyazaki, Y.; K. Kita; Wiedensohler, A.; Takegawa, N.; Nowak, A.; P. Achtert; Rose, D.; Schmid, O.; Yang, H.; R. M. Garland

    2008-01-01

    The scattering and absorption of solar radiation by atmospheric aerosols is a key element of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however, highly variable and not well characterized, especially near newly emerging mega-cities. In this study, aerosol optical properties were measured at a rural site approximately 60 km northwest of the mega-city Guangzhou in southeast China. The measurements were part of the PRIDE-PRD2006 intens...

  12. Aerosol optical properties in a rural environment near the mega-city Guangzhou, China: implications for regional air pollution and radiative forcing

    R. M. Garland; Yang, H.; Schmid, O.; Rose, D.; Nowak, A.; P. Achtert; Wiedensohler, A.; Takegawa, N.; K. Kita; Miyazaki, Y.; Kondo, Y.; Hu, M.; M. Shao; Zeng, L; Zhang, Y.

    2008-01-01

    The scattering and absorption of solar radiation by atmospheric aerosols is a key element of the Earth's radiative energy balance and climate. The optical properties of aerosol particles are, however, highly variable and not well characterized, especially near newly emerging mega-cities. In this study, aerosol optical properties were measured at a regional background site approximately 60 km northwest of the mega-city Guangzhou in southeast China. The measurements were part of the "...

  13. Real Time Position Detection by Using GPS+GSM+GPRS and Arduino Mega Based Telit GL865

    Baki Koyuncu

    2016-01-01

    Full Text Available A web application on a mobile platform is developed by using GPS, GSMand GPRSon an Arduino Mega board to determine the object positions in real time.The system receives the GPS position data and sends it to a distant server through a GSM channel by using GPRS and an Arduino Mega board. Position data is displayed on a Google map on the server or a mobile cell phone. U BloxLea is deployed as the GPS device, Telit GL865 is used as the combined GSM and GPRS devices. GPS data is received every 1 second and sent every 10 seconds through GSM channel. An SD card is introduced to log the GPS and GSM data. An important advantage of this application is that the user can control the system from a cell phone and receive the location information of the system in real time.

  14. Studies on the drift properties and spatial resolution using a microMEGAS-equipped time projection chamber

    Rosario L Reserva; Dennis C Arogancia; Angelina M Bacala; Khalil Boudjemline; Dan Burke; Paul Colas; Madhu Dixit; Arnaud Giganon; Ioannis Giomataris; Hermogenes C Gooc Jr; Yukihiro Kato; Keisuke Fujii; Hiroyuki Fujishima; Masahiro Habu; Takatoshi Higashi; Makoto Kobayashi; Hirotoshi Kuroiwa; Vincent Lepeltier; Takeshi Matsuda; Osamu Nitoh; Kirsten Sachs; Ronald Dean Settles; Akira Sugiyama; Philippe Rosier; Sachio Matsushita; Keiichi Nakamura; Takashi Watanabe; Atsushi Yamaguchi; Hiroshi Yamaoka; Thomas Zeruerras

    2007-12-01

    R & D studies on the performance as well as on the gas properties of the microMEGAS-based time projection chamber with standard readout were carried out in June 2005 using 4 GeV/c pion beam in a magnetic field from 0 to 1 T at the proton synchrotron beam line at KEK, Japan. Analysis of the electron drift velocity, diffusion constant and point resolution of padrow measurement for MicroMEGAS TPC filled with 95% argon and 5% isobutane gas are presented. The underlying physical mechanism which determines the optimal TPC performance are briefly discussed. Preliminary measurements of gas properties and spatial resolution in close agreement with the analytical calculation and MAGBOLTZ simulation are summarized and presented in this paper.

  15. Study on the effect of humidity and dust on leakage current of bulk micro-MEGAS detector

    Wang, Bo; Qi, Hui-Rong; Liu, Jing; Zhang, Xin-Shuai; Zhang, Tian-Chong; Yi, Fu-Ting; Ou-Yang, Qun; Chen, Yuan-Bo

    2013-01-01

    In this paper, the effect of humidity and dust trapped in avalanche region on leakage current of bulk micro-MEGAS detector is studied. Pyralux PC1025 layers of DuPont are introduced in bulk technique and micro-MEGAS detector with pillars of 300{\\mu}m in diameter is fabricated. Leakage current is tested in air with different humidity. Silicon carbide powder and PMMA (polymethyl methacrylate) powder are added as dust to avalanche region. Leakage current with and without powder is tested in air and results are depicted in the same figure. Test results indicate that leakage current increases with both storage humidity and test humidity, and also increases when powder is introduced in avalanche region.

  16. Micelle size modulation and phase behavior in MEGA-10/Triton X-100 mixtures

    Naous, M., E-mail: elzahraadz@yahoo.fr; Molina-Bolívar, J.A.; Ruiz, C. Carnero, E-mail: ccarnero@uma.es

    2014-12-20

    Highlights: • The size of micelles was studied as a function of the micellar composition, NaCl addition and temperature. • Cloud point can be modulated by changing both micellar composition and NaCl addition. • The energetic quantities at the cloud point were evaluated and discussed. - Abstract: This paper reports the effect of temperature and NaCl addition on micelle size and phase behavior in mixtures of N-decanoyl-N-methylglucamide (MEGA-10) and p-tert-octyl-phenoxy polyethylene (9.5) ether (Triton X-100 or TX100). The size of mixed micelles, as determined by dynamic light scattering (DLS), was found to increase with temperature but to be less pronounced at higher proportions of MEGA-10 in the solution. The cloud point was found to increase with an initial increase in the percentage of sugar-based surfactant in the mixture. This phase separation was sensitive to the presence of NaCl in the micellar solution, which induced a cloud point depression, thereby suggesting that the presence of electrolyte produces a marked alteration of the hydration layer of micelles. A thermodynamic analysis was performed assuming the clouding phenomenon to be a liquid–liquid phase-separation process. The resulting ΔG{sub CP}{sup 0} values were positive for all solutions. The cloud point process was exothermic in nature for the mixed micellar system, as proven by the negative value of ΔH{sub CP}{sup 0}. The process was more exothermic as the proportion of sugar-based surfactant in the mixed micelle increased (with and without NaCl in the solution). Furthermore, the negative values of ΔS{sub CP}{sup 0} indicate that the association of micelles in the clouding phenomenon is entropically unfavorable. It was observed from the enthalpy–temperature plots that the change in heat capacity is negative, thus indicating the important role played by dehydration in this thermodynamic process. This study found that the enthalpy–entropy compensation relationship holds for this

  17. Micelle size modulation and phase behavior in MEGA-10/Triton X-100 mixtures

    Highlights: • The size of micelles was studied as a function of the micellar composition, NaCl addition and temperature. • Cloud point can be modulated by changing both micellar composition and NaCl addition. • The energetic quantities at the cloud point were evaluated and discussed. - Abstract: This paper reports the effect of temperature and NaCl addition on micelle size and phase behavior in mixtures of N-decanoyl-N-methylglucamide (MEGA-10) and p-tert-octyl-phenoxy polyethylene (9.5) ether (Triton X-100 or TX100). The size of mixed micelles, as determined by dynamic light scattering (DLS), was found to increase with temperature but to be less pronounced at higher proportions of MEGA-10 in the solution. The cloud point was found to increase with an initial increase in the percentage of sugar-based surfactant in the mixture. This phase separation was sensitive to the presence of NaCl in the micellar solution, which induced a cloud point depression, thereby suggesting that the presence of electrolyte produces a marked alteration of the hydration layer of micelles. A thermodynamic analysis was performed assuming the clouding phenomenon to be a liquid–liquid phase-separation process. The resulting ΔGCP0 values were positive for all solutions. The cloud point process was exothermic in nature for the mixed micellar system, as proven by the negative value of ΔHCP0. The process was more exothermic as the proportion of sugar-based surfactant in the mixed micelle increased (with and without NaCl in the solution). Furthermore, the negative values of ΔSCP0 indicate that the association of micelles in the clouding phenomenon is entropically unfavorable. It was observed from the enthalpy–temperature plots that the change in heat capacity is negative, thus indicating the important role played by dehydration in this thermodynamic process. This study found that the enthalpy–entropy compensation relationship holds for this process. The micelle–water interactions

  18. [Medical ethics in residency training].

    Civaner, Murat; Sarikaya, Ozlem; Balcioğlu, Harun

    2009-04-01

    Medical ethics education in residency training is one of the hot topics of continuous medical education debates. Its importance and necessity is constantly stressed in declarations and statements on national and international level. Parallel to the major structural changes in the organization and the finance model of health care system, patient-physician relationship, identity of physicianship, social perception and status of profession are changing. Besides, scientific developments and technological advancements create possibilities that never exists before, and bring new ethical dilemmas along with. To be able to transplant human organs has created two major problems for instance; procurement of organs in sufficient numbers, and allocating them to the patients in need by using some prioritizing criteria. All those new and challenging questions force the health care workers to find authentic and justifiable solutions while keeping the basic professional values. In that sense, proper medical ethics education in undergraduate and postgraduate term that would make physician-to-be's and student-physicians acquire the core professional values and skill to notice, analyze and develop justifiable solutions to ethical problems is paramount. This article aims to express the importance of medical ethics education in residency training, and to propose major topics and educational methods to be implemented into. To this aim, first, undergraduate medical education, physician's working conditions, the exam of selection for residency training, and educational environment were revised, and then, some topics and educational methods, which are oriented to educate physicians regarding the professional values that they should have, were proposed. PMID:19357056

  19. Redesigning journal club in residency

    Al Achkar M

    2016-05-01

    Full Text Available Morhaf Al Achkar Department of Family Medicine, Indiana University, Indianapolis, IN, USA Abstract: The gap between production and implementation of knowledge is the main reason for the suboptimal quality of health care. To eliminate this gap and improve the quality of patient care, journal club (JC in graduate medical education provides an opportunity for learning the skills of evidence-based medicine. JC, however, continues to face many challenges mainly due to poorly defined goals, inadequate preparation, and lack of interest. This article presents an innovative model to prepare and present JC based on three pillars: dialogical learning through group discussion, mentored residents as peer teachers, and including JC as part of a structured curriculum to learn evidence-based medicine. This engaging model has the potential to transform JC from a moribund session that is daunting for residents into a lively discussion to redefine clinical practice using the most current evidence. Keywords: journal club, residents, peer teaching, evidence-based medicine, dialogical learning

  20. Survival and evolution of a large multidrug resistance plasmid in new clinical bacterial hosts

    Porse, Andreas; Schønning, Kristian; Munck, Christian;

    2016-01-01

    and population sequencing to show that the long-term persistence and molecular integrity of the plasmid is highly influenced by multiple factors within a 25 kb plasmid region constituting a host-dependent burden. In the E. coli hosts investigated here, improved plasmid stability readily evolves via IS......Large conjugative plasmids are important drivers of bacterial evolution and contribute significantly to the dissemination of antibiotic resistance. Although plasmid borne multidrug resistance is recognized as one of the main challenges in modern medicine, the adaptive forces shaping the evolution...... of these plasmids within pathogenic hosts are poorly understood. Here we study plasmid-host adaptations following transfer of a 73 kb conjugative multidrug resistance plasmid to naïve clinical isolates of Klebsiella pneumoniae and Escherichia coli We use experimental evolution, mathematical modelling...

  1. Survival and evolution of a large multidrug resistance plasmid in new clinical bacterial hosts

    Porse, Andreas; Schønning, Kristian; Munck, Christian;

    2016-01-01

    Large conjugative plasmids are important drivers of bacterial evolution and contribute significantly to the dissemination of antibiotic resistance. Although plasmid borne multidrug resistance is recognized as one of the main challenges in modern medicine, the adaptive forces shaping the evolution...... of these plasmids within pathogenic hosts are poorly understood. Here we study plasmid-host adaptations following transfer of a 73 kb conjugative multidrug resistance plasmid to naïve clinical isolates of Klebsiella pneumoniae and Escherichia coli We use experimental evolution, mathematical modelling and population...... sequencing to show that the long-term persistence and molecular integrity of the plasmid is highly influenced by multiple factors within a 25 kb plasmid region constituting a host-dependent burden. In the E. coli hosts investigated here, improved plasmid stability readily evolves via IS26 mediated deletions...

  2. Conservation of plasmids among plant-pathogenic Pseudomonas syringae isolates of diverse origins.

    von Bodman, S B; Shaw, P D

    1987-05-01

    Thirty isolates of Pseudomonas syringae pv. tabaci, pv. angulata (pathogens on tobacco), pv. coronafaciens, and pv. striafaciens (pathogens on oats) were examined for plasmid DNAs. The strains were obtained from plants throughout the world, some over 50 years ago. Of the 22 tobacco pathogens, 16 contain predominantly one type of plasmid, the pJP27.00 type. The remaining six tobacco-specific strains do not harbor detectable plasmids. The oat pathogens contain one, two, or three plasmids. DNA homology studies indicate that the plasmid DNAs are highly conserved. More importantly, the plasmids harbored by strains isolated from one host plant are conserved most stringently; e.g., the plasmids from the tobacco pathogens are, with one exception, indistinguishable by restriction endonuclease digestion and Southern hybridization. There is also extensive homology among plasmids indigenous to the oat-specific P. syringae pv. coronafaciens and pv. striafaciens strains. PMID:3628554

  3. Possible involvement of a plasmid in arginine auxotrophic mutation of Streptomyces kasugaensis.

    Nakano, M M; Ozawa, K; Ogawara, H

    1980-01-01

    Streptomyces kasugaensis gave arginine auxotrophic mutants at high frequency, The coupled loss and reappearance of plasmid deoxyribonucleic acid with arginine auxotrophy suggested that the insertion of the plasmid into chromosomal deoxyribonucleic acid caused the arginine auxotrophy.

  4. A Time-Efficient and User-Friendly Method for Plasmid DNA Restriction Analysis.

    LaBanca, Frank; Berg, Claire M.

    1998-01-01

    Describes an experiment in which plasmid DNA is digested with restriction enzymes that cleave the plasmid either once or twice. The DNA is stained, loaded on a gel, electrophoresed, and viewed under normal laboratory conditions during electrophoresis. (DDR)

  5. Transcription of ColE1Ap mbeC induced by conjugative plasmids from twelve different incompatibility groups.

    Selvaratnam, S; Gealt, M A

    1993-01-01

    Although nonconjugative mobilizable plasmids require helping functions of conjugative plasmids in order to be mobilized into recipients, at least some genes from the nonconjugative plasmids may be induced to assist in the DNA transfer process. Conjugative plasmids from 12 different incompatibility groups mobilized the nonconjugative plasmid ColE1Ap between Escherichia coli strains. Introduction of any of the conjugative plasmids into the ColE1Ap-containing strain resulted in an induction of m...

  6. Partition locus-based classification of selected plasmids in Klebsiella pneumoniae, Escherichia coli and Salmonella enterica spp.: An additional tool

    Bousquet, A.; Henquet, S.; Compain, F.; Genel, N.; Arlet, G.; Decré, D

    2015-01-01

    The dissemination of antimicrobial resistance genes in Enterobacteriaceae has been largely attributed to plasmids, circular DNA molecules capable of autonomous replication. Whereas high-copy-number plasmids primarily rely on passive diffusion for plasmid maintenance, low-copy-number plasmids utilize so-called partition (par) systems. Plasmid partition relies on three structures, i.e. a centromere like DNA site, a centromere-binding protein and an ATPase or a GTPase motor protein for plasmid p...

  7. Impacts of Mega-droughts on Water and Food Security in the Indo-Gangetic Plains: A Paleoclimate Scenario Analysis

    Zhu, T.; Pitois, G.; Ringler, C.; Wang, D.; Rosegrant, M. W.

    2014-12-01

    Spanning over Pakistan, northern India, Nepal, and Bangladesh, the Indo-Gangetic Plains (IGP) is the home of several hundred million people and the "bread basket" for much of South Asia. The flat terrain, fertile soils, and favorable climate of the IGP make it agriculturally productive. However prolonged droughts caused by consecutive monsoon failures can seriously affect crop production and social wellbeing, in particular for the eastern part of the plains where agriculture remains largely rain-fed. Severe droughts were observed in the IGP historically, and recent paleoclimate studies reveal that more severe and long-lasting "mega-droughts" had happened in the distant past. Agricultural losses from major droughts can dramatically affect food systems and increase the vulnerability of resource-poor people given the delicate balance between food supply and demand under growing natural resource scarcity. To estimate the potential impacts of "mega-droughts" on the water and food systems in the IGP, we develop worst-case drought scenarios through inverse modeling of tree-ring-based PDSI reconstruction that covers the period 1300-1899 (A.D.), and analyze these historic mega-drought scenarios using IFPRI's IMPACT global water and food projections model. The base year of the IMPACT model is parameterized using socioeconomic and engineering data that reflect today's water management and infrastructure, agricultural technologies, population, income, and market institutions. The base year simulation is validated against observations to ensure model fidelity. Anticipated changes of the above factors in the future out to 2050 are specified using demographic and economic growth projections and literature data. Model simulation results represent the consequences of mega-droughts in the IGP given technological and socioeconomic conditions of today and in the future. We also explore policy options for increasing the resilience of water and food systems in the IGP, through scenario

  8. The Role of Mega-events in Country Branding : Case Study on Brand of Ukraine before European Football Championship 2012

    Klonova, Anastasiia

    2012-01-01

    Successful presentation of a country as a brand and positioning its unique image on the global level can give significant opportunities for development and progress of the state in the different areas. This research applies theories on the country branding to estimate impact of mega sport events on the image of state. To accomplish these goal I used case study – formation of brand Ukraine before hosting European Football Championship 2012 (EURO 2012). To investigate  brand strategy of Ukraine...

  9. Perfil de colesterol de ovos comerciais e ovos enriquecidos com ácidos graxos polinsaturados ômega-3

    Mourthé K.; Martins R.T.

    2002-01-01

    Determinou-se quantitativamente, por cromatografia gasosa, o teor colesterol de ovos enriquecidos com ácidos graxos polinsaturados ômega-3 e de ovos comuns disponíveis no mercado de Belo Horizonte/MG. Foram analisadas duas marcas de ovos comuns e duas de ovos enriquecidos com cinco repetições por amostragem. Não houve diferença entre os níveis de colesterol para os tipos de ovos estudados.

  10. EDUCATIONAL USE OF CLOUD COMPUTING AND AT-MEGA MICROCONTROLLER - A CASE STUDY OF AN ALARM SYSTEM

    Tomasz Cieplak; Dariusz Lecyk; Agnieszka Cieplak

    2016-01-01

    The article shows a case study of Cloud Computing model combined with AT-Mega microcontrollers for educational purposes. The presented system takes advantage of many aspects of Internet of Things model, thus conjoining Cloud Management system with measurement-execution module based on Arduino platform. One benefit of this solution is a cost-effective way of showcasing machine and device integration with distinct cloud services. This article is based on practical experience with students' proj...

  11. Antimicrobial endophytic fungal assemblages inhabiting bark of Taxus baccata L. of Indo-Burma mega biodiversity hotspot

    Tayung, K.; Jha, D. K.

    2010-01-01

    Fungal endophytes were isolated from inner bark of Taxus baccata L., an important source of potent anticancer drug taxol. Bark samples were collected from two locations of Arunachal Pradesh, India, part of the Indo-Burma mega biodiversity hotspot, during two seasons i.e. monsoon and winter. Altogether 77 fungal strains representing 18 genera were isolated from T. baccata bark during the present investigation. The colonizing frequency was recorded as 38.5% and the fungal community comprised of...

  12. POTENTIAL OF TSUNAMI GENERATION ALONG THE COLOMBIA/ECUADOR SUBDUCTION MARGIN AND THE DOLORES-GUAYAQUIL MEGA-THRUST

    George Pararas-Carayannis

    2012-01-01

    The Colombia/Ecuador subduction zone is a region where high seismic stress is presently accumulating. Statistical probability studies and GPS measurements of crustal deformation indicate that the region has an increased potential to generate in the near future a major or great tsunamigenic earthquake similar to the 1979 or 1906. Although most of the major earthquakes along this margin usually generate local tsunamis, the recurrence of a great mega-thrust, inter-plate earthquake, similar in ma...

  13. New tetracycline resistance determinant on R plasmids from Vibrio anguillarum.

    Aoki, T.; Satoh, T.; Kitao, T.

    1987-01-01

    Two classes of tetracycline resistance determinants on R plasmids were detected in Vibrio anguillarum strains isolated from ayu (sweat fish; Plecoglossus altivelis) farms in Japan. Tetracycline resistance genes categorized as class B were prevalent from 1973 to 1977; however, a new tetracycline resistance gene, which was not classified into tetracycline resistance determinant class A, B, C, or D, has been prevalent since 1981.

  14. Pharmaceutical development of the plasmid DNA vaccine pDERMATT

    Quaak, S.G.L.

    2009-01-01

    The discovery of tumor specific antigens and self tolerance mechanisms against these antigens led to the assumption that antigens circulating at sufficient concentration levels could break this self tolerance mechanism and evoke immunological antitumor effects. pDERMATT (plasmid DNA encoding recombi

  15. Stability of Integrated Plasmids in the Chromosome of Lactococcus lactis

    Leenhouts, Kees J.; Kok, Jan; Venema, Gerhardus

    1990-01-01

    Derivatives of plasmids pBR322, pUB110, pSC101, and pTB19, all containing an identical fragment of lactococcal chromosomal DNA, were integrated via a Campbell-like mechanism into the same chromosomal site of Lactococcus lactis MG1363, and the transformants were analyzed for the stability of the inte

  16. Plasmid-determined copper resistance in Pseudomonas syringae from impatiens

    Cooksey, D.A. (Univ. of California, Riverside (USA))

    1990-01-01

    A strain of Pseudomonas syringae was recently identified as the cause of a new foliar blight of impatiens. The bacterium was resistant to copper compounds, which are used on a variety of crops for bacterial and fungal disease control. The bacterium contained a single 47-kilobase plasmid (pPSI1) that showed homology to a copper resistance operon previously cloned and characterized from P. syringae pv. tomato plasmid pPT23D (D. Cooksey, Appl. Environ. Microbiol. 53:454-456, 1987). pPSI1 was transformed by electroporation into a copper-sensitive P. syringae strain, and the resulting transformants were copper resistant. A physical map of pPSI1 was constructed, and the extent of homology to pPT23D outside the copper resistance operon was determined in Southern hybridizations. The two plasmids shared approximately 20 kilobases of homologous DNA, with the remainder of each plasmid showing no detectable homology. The homologous regions hybridized strongly, but there was little or no conservation of restriction enzyme recognition sites.

  17. Studying plasmid horizontal transfer in situ: a critical review

    Sørensen, Søren Johannes; Bailey, Mark; Hansen, Lars Hestbjerg;

    2005-01-01

    This review deals with the prospective, experimental documentation of horizontal gene transfer (HGT) and its role in real-time, local adaptation. We have focused on plasmids and their function as an accessory and/or adaptive gene pool. Studies of the extent of HGT in natural environments have...

  18. Use of plasmid DNA for induction of protective immunity

    Lorenzen, Niels

    2004-01-01

    Vaccines based on plasmid DNA have been tested for a number of fish pathogens but so far it is only in case of the rhabdoviruses, where the technology has been a real break through in vaccine research. Aspects of dose, time-course and mechanisms of protection, as well as practical use are discussed....

  19. Multilocus sequence typing of IncN plasmids

    García-Fernández, Aurora; Villa, Laura; Moodley, Arshnee; Hasman, Henrik; Miriagou, Vivi; Guardabassi, Luca; Carattoli, Alessandra

    2011-01-01

    OBJECTIVES: Incompatibility group N (IncN) plasmids have been associated with the dissemination of antimicrobial resistance and are a major vehicle for the spread of blaVIM-1 in humans and blaCTX-M-1 in animals. A plasmid multilocus sequence typing (pMLST) scheme was developed for rapid......, Greece, Denmark, UK and The Netherlands) were classified by DNA sequencing of the amplicons obtained for the repA, traJ and korA loci. RESULTS: Eleven sequence types (STs) were defined on the basis of allele sequences of the three selected loci. Most plasmids carrying blaCTX-M-1 (24/27) isolated in...... spread and persistence of this particular IncN-carrying blaVIM-1 lineage in Greece. CONCLUSIONS: This study proposes the use of pMLST as a suitable and rapid method for identification of IncN epidemic plasmid lineages. The recent spread of blaCTX-M-1 among humans and animals seems to be associated with...

  20. [Transfer of plasmid beta-lactamases in enterobacteria].

    Umaran, A; Garaizar, J; Gallego, L; Colom, K; Cisterna, R

    1989-04-01

    The aim of the present study was to determine which types of beta-lactamases codified by plasmids are transferred by conjugation from several species of enterobacteria. To this end, 352 strains of ampicillin-resistant enterobacteria from clinical samples from the Hospital Civil of Bilbao were evaluated. Their beta-lactamase activity and their capacity to transfer this capacity by conjugation were evaluated. The several types of plasmidic beta-lactamases in the strains that conjugated and in their respective transconjugants were characterized by analytic isoelectric approach, and also the sensitivity of these stains to 20 beta-lactamic antibiotics and the size of their plasmids. Twenty different types were detected, with a clear predominance of TEM 1. Type TEM 2 was found in 19% of the strains which conjugated, and much less commonly the types SHV 1, HMS 1 and a beta-lactamase of an approximate pl of 4.9 were found. The transfer of these beta-lactamases is mediated by a great variety of plasmids and is associated with variable levels of resistance to penicillins and unstable cephalosporins. The presence of betalactamases with activity on the more stable cephalosporins has not been detected. PMID:2490696

  1. Plasmid profiles of clinical and environmental isolates of Legionella pneumophila serogroup 1.

    Maher, W E; Plouffe, J F; Para, M F

    1983-01-01

    Clinical and environmental Legionella pneumophila serogroup 1 isolates from a single water source in Columbus, Ohio, exhibited five different plasmid profiles. The multiplicity of plasmid profiles observed within a single geographic area and a skewed distribution of isolates bearing these plasmid profiles within this area suggest that plasmid analyses will be useful in the study of the epidemiology of Legionnaires disease and the environmental distribution of legionellae.

  2. Plasmid marker rescue transformation proceeds by breakage-reunion in Bacillus subtilis.

    Weinrauch, Y; Dubnau, D

    1987-01-01

    Bacillus subtilis carrying a plasmid which replicates with a copy number of about 1 was transformed with linearized homologous plasmid DNA labeled with the heavy isotopes 2H and 15N, in the presence of 32Pi and 6-(p-hydroxyphenylazo)-uracil to inhibit DNA replication. Plasmid DNA was isolated from the transformed culture and fractionated in cesium chloride density gradients. The distribution of total and donor plasmid DNA was examined, using specific hybridization probes. The synthesis of new...

  3. Incidence of Plasmids in Thermus spp. Isolated in Yellowstone National Park

    Munster, Michael J.; Munster, Ann P.; Sharp, Richard J.

    1985-01-01

    Forty-eight strains of Thermus spp. were isolated from thermal sites in Yellowstone National Park, Wyo., and 62.5% showed evidence of plasmid DNA. Attempts to assign function to the plasmid DNA were unsuccessful, and the presence of plasmid DNA could not be correlated with antibiotic or heavy metal resistance. A number of these cryptic plasmids are now being investigated for their potential as vectors for molecular cloning in Thermus spp.

  4. A DNA polymerase mutation that suppresses the segregation bias of an ARS plasmid in Saccharomyces cerevisiae.

    Houtteman, S W; Elder, R T

    1993-01-01

    Yeast autonomously replicating sequence (ARS) plasmids exhibit an unusual segregation pattern during mitosis. While the nucleus divides equally into mother and daughter cells, all copies of the ARS plasmid will often remain in the mother cell. A screen was designed to isolate mutations that suppress this segregation bias. A plasmid with a weak ARS (wARS) that displayed an extremely high segregation bias was constructed. When cells were grown under selection for the wARS plasmid, the resulting...

  5. Modulation of ColE1-like Plasmid Replication for Recombinant Gene Expression

    Camps, Manel

    2010-01-01

    ColE1-like plasmids constitute the most popular vectors for recombinant protein expression. ColE1 plasmid replication is tightly controlled by an antisense RNA mechanism that is highly dynamic, tuning plasmid metabolic burden to the physiological state of the host. Plasmid homeostasis is upset upon induction of recombinant protein expression because of non-physiological levels of expression and because of the frequently biased amino acid composition of recombinant proteins. Disregulation of p...

  6. Participation of the lytic replicon in bacteriophage P1 plasmid maintenance.

    Yarmolinsky, M B; Hansen, E B; Jafri, S; Chattoraj, D K

    1989-01-01

    P1 bacteriophage carries at least two replicons: a plasmid replicon and a viral lytic replicon. Since the isolated plasmid replicon can maintain itself stably at the low copy number characteristic of intact P1 prophage, it has been assumed that this replicon is responsible for driving prophage replication. We provide evidence that when replication from the plasmid replicon is prevented, prophage replication continues, albeit at a reduced rate. The residual plasmid replication is due to incomp...

  7. Stability in Escherichia coli of an antibiotic resistance plasmid from Bacteroides fragilis.

    Rashtchian, A; Booth, S J

    1981-01-01

    A Bacteroides fragilis strain resistant to penicillin G, tetracycline, and clindamycin was screened for the presence of plasmid deoxyribonucleic acid (DNA). Agarose gel electrophoresis of ethanol-precipitated DNA from cleared lysates of this strain revealed two plasmid DNA bands. The molecular weights of the plasmids were estimated by their relative mobility in agarose gel and compared with standard plasmids with known molecular weights. The molecular weights were 3.40 +/- 0.20 x 10(6) and 1....

  8. Properties of R1162, a broad-host-range, high-copy-number plasmid.

    R. MEYER; Hinds, M; Brasch, M.

    1982-01-01

    Regions of plasmid DNA encoding characteristic properties of the IncQ (P-4) group plasmid R1162 were identified by mutagenesis and in vitro cloning. Coding sequences sufficient for expression of incompatibility and efficient conjugal mobilization by plasmid R751 were found to be linked to the origin of DNA replication. In contrast, there was a region remote from the origin, and active in trans, that was required for plasmid maintenance. A derivative that was temperature sensitive for stabilit...

  9. Characterization of different plasmid-borne dihydropteroate synthases mediating bacterial resistance to sulfonamides.

    Swedberg, G; Sköld, O

    1980-01-01

    Plasmid-borne resistance to sulfonamides was studied in both newly isolated and earlier characterized R plasmids. Two different classes of drug-resistant dihydropteroate synthases were found to be responsible for most cases of plasmid-mediated sulfonamide resistance. The plasmid-coded enzymes could be completely separated from their chromosomal counterpart and also showed differences in heat stability and molecular size. The resistant and chromosomal enzymes could bind the normal substrate, p...

  10. Use of agarose gel electrophoresis of plasmid deoxyribonucleic acid to fingerprint gram-negative bacilli.

    Schaberg, D.R.; Tompkins, L S; Falkow, S

    1981-01-01

    Agarose gel electrophoresis of the plasmid deoxyribonucleic acids from 60 gram-negative bacilli recovered during investigations of nosocomial epidemics was used to fingerprint the strains. This method was as specific at differentiating bacterial strains as more conventional phenotyping methods. In all cases, plasmid band fingerprints of epidermic strains isolates were identical whereas coisolate plasmid deoxyribonucleic acid patterns were different. Agarose gel electrophoresis of plasmid deox...

  11. Identification of tetracycline-resistant R-plasmids in Streptococcus agalactiae (group B).

    Burdett, V

    1980-01-01

    In this report, 30 tetracycline-resistant clinical isolates of group B Streptococcus were examined to assess the extent to which tetracycline resistance is plasmid mediated. Of these, 27 showed no physical or genetic evidence of plasmid-mediated resistance; however, one conjugative and two small (3.5 X 10(6)-dalton) multicopy non-self-transmissible tetracycline resistance plasmids were identified. The conjugative plasmid was transmissible to Streptococcus faecalis as well as to Streptococcus ...

  12. The Salmonella virulence plasmid enhances Salmonella-induced lysis of macrophages and influences inflammatory responses.

    Guilloteau, L. A.; Wallis, T S; A.V. Gautier; Macintyre, S.; Platt, D. J.; Lax, A J

    1996-01-01

    The Salmonella dublin virulence plasmid mediates systemic infection in mice and cattle. Here, we analyze the interaction between wild-type and plasmid-cured Salmonella strains with phagocytes in vitro and in vivo. The intracellular recovery of S. dublin from murine peritoneal and bovine alveolar macrophages cultured in the presence of gentamicin in vitro was not related to virulence plasmid carriage. However, the virulence plasmid increased the lytic activity of S. dublin, Salmonella typhimur...

  13. Complete DNA Sequence and Analysis of the Large Virulence Plasmid of Shigella flexneri

    Venkatesan, Malabi M.; Goldberg, Marcia B.; Rose, Debra J.; Grotbeck, Erik J.; Burland, Valerie; Blattner, Frederick R.

    2001-01-01

    The complete sequence analysis of the 210-kb Shigella flexneri 5a virulence plasmid was determined. Shigella spp. cause dysentery and diarrhea by invasion and spread through the colonic mucosa. Most of the known Shigella virulence determinants are encoded on a large plasmid that is unique to virulent strains of Shigella and enteroinvasive Escherichia coli; these known genes account for approximately 30 to 35% of the virulence plasmid. In the complete sequence of the virulence plasmid, 286 ope...

  14. The critical role of the linear plasmid lp36 in the infectious cycle of Borrelia burgdorferi

    Mollie W Jewett; Lawrence, Kevin; Bestor, Aaron C; Tilly, Kit; Grimm, Dorothee; Shaw, Pamela; VanRaden, Mark; Gherardini, Frank; Rosa, Patricia A.

    2007-01-01

    Borrelia burgdorferi, the aetiological agent of Lyme disease, follows a life cycle that involves passage between the tick vector and the mammalian host. To investigate the role of the 36 kb linear plasmid, lp36 (also designated the B. burgdorferi K plasmid), in the infectious cycle of B. burgdorferi, we examined a clone lacking this plasmid, but containing all other plasmids known to be required for infectivity. Our results indicated that lp36 was not required for spirochete survival in the t...

  15. Conservation of Plasmid-Encoded Traits among Bean-Nodulating Rhizobium Species

    Brom, Susana; Girard, Lourdes; García-de los Santos, Alejandro; Sanjuan-Pinilla, Julio M.; Olivares, José; Sanjuan, Juan

    2002-01-01

    Rhizobium etli type strain CFN42 contains six plasmids. We analyzed the distribution of genetic markers from some of these plasmids in bean-nodulating strains belonging to different species (Rhizobium etli, Rhizobium gallicum, Rhizobium giardinii, Rhizobium leguminosarum, and Sinorhizobium fredii). Our results indicate that independent of geographic origin, R. etli strains usually share not only the pSym plasmid but also other plasmids containing symbiosis-related genes, with a similar organi...

  16. Tn5-mediated transposition of plasmid DNA after transduction to Myxococcus xanthus.

    Downard, J S

    1988-01-01

    After coliphage P1-mediated transfer of Tn5-containing plasmid DNA from Escherichia coli to Myxococcus xanthus, transductants were identified which contained plasmid sequences integrated at many sites on the bacterial chromosome. The unaltered plasmid DNA sequences in these transductants were apparently flanked by intact Tn5 or IS50 sequences. These results suggest that Tn5-mediated transposition has occurred and provide a method for integrating plasmid DNA into the M. xanthus chromosome with...

  17. Rapid procedure for isolation of plasmid DNA and application to epidemiological analysis.

    Takahashi, S; Nagano, Y

    1984-01-01

    A rapid and simple plasmid isolation procedure was developed for the epidemiological analysis of plasmid-mediated antimicrobial resistance. By this method, plasmid DNAs ranging in molecular weight between 2.0 and 122 X 10(6) could be detected. Various bacteria, such as strains of the family Enterobacteriaceae, Pseudomonas aeruginosa, Haemophilus influenzae, and Staphylococcus aureus, could be analyzed. The plasmid DNA obtained could be directly used for restriction endonuclease analysis witho...

  18. Microneedle-mediated transcutaneous immunization with plasmid DNA coated on cationic PLGA nanoparticles

    Kumar, Amit; Wonganan, Piyanuch; Sandoval, Michael A.; Li, Xinran; Zhu, Saijie; Cui, Zhengrong

    2012-01-01

    Previously, it was shown that microneedle-mediated transcutaneous immunization with plasmid DNA can potentially induce a stronger immune response than intramuscular injection of the same plasmid DNA. In the present study, we showed that the immune responses induced by transcutaneous immunization by applying plasmid DNA onto a skin area pretreated with solid microneedles were significantly enhanced by coating the plasmid DNA on the surface of cationic nanoparticles. In addition, the net surfac...

  19. Characterization of the OCT plasmid encoding alkane oxidation and mercury resistance in Pseudomonas putida.

    Harder, P A; Kunz, D A

    1986-01-01

    Transformation of Pseudomonas putida and analysis for plasmid DNA revealed that both n-alkane oxidation and mercury resistance are encoded on a single 220-megadalton OCT plasmid molecule. Derivatives of OCT having lost the mercury resistance function could be readily isolated and contained a smaller plasmid estimated to be 170 megadaltons. The results show that segregation of the mercury resistance property occurs not by loss of a separate MER plasmid as previously thought but by a deletion i...

  20. Enhanced expressions and histological characteristics of intravenously administered plasmid DNA in rat lung.

    Rha, S. J.; Y. P. Wang

    2001-01-01

    Cationic liposome-mediated gene transfection is a promising method for gene therapy. In this study, the transfection efficiency and histological patterns were evaluated in rat lung after intravenous administration via femoral vein of naked plasmid DNA, naked plasmid DNA with pretreatment of DOTAP, and DOTAP-cholesterol-plasmid DNA complex. Plasmid DNA encoding bacterial LacZ gene was used. For quantification of LacZ gene expression, beta-galactosidase assay was performed. For histologic exami...

  1. Comparison of electrically mediated and liposome-complexed plasmid DNA delivery to the skin

    Heller, Loree C.; Jaroszeski, Mark J; Coppola, Domenico; Heller, Richard

    2008-01-01

    Background Electroporation is an established technique for enhancing plasmid delivery to many tissues in vivo, including the skin. We have previously demonstrated efficient delivery of plasmid DNA to the skin utilizing a custom-built four-plate electrode. The experiments described here further evaluate cutaneous plasmid delivery using in vivo electroporation. Plasmid expression levels are compared to those after liposome mediated delivery. Methods Enhanced electrically-mediated delivery, and ...

  2. Communicating mega-projects in the face of uncertainties: Israeli mass media treatment of the Dead Sea Water Canal.

    Fischhendler, Itay; Cohen-Blankshtain, Galit; Shuali, Yoav; Boykoff, Max

    2015-10-01

    Given the potential for uncertainties to influence mega-projects, this study examines how mega-projects are deliberated in the public arena. The paper traces the strategies used to promote the Dead Sea Water Canal. Findings show that the Dead Sea mega-project was encumbered by ample uncertainties. Treatment of uncertainties in early coverage was dominated by economics and raised primarily by politicians, while more contemporary media discourses have been dominated by ecological uncertainties voiced by environmental non-governmental organizations. This change in uncertainty type is explained by the changing nature of the project and by shifts in societal values over time. The study also reveals that 'uncertainty reduction' and to a lesser degree, 'project cancellation', are still the strategies most often used to address uncertainties. Statistical analysis indicates that although uncertainties and strategies are significantly correlated, there may be other intervening variables that affect this correlation. This research also therefore contributes to wider and ongoing considerations of uncertainty in the public arena through various media representational practices. PMID:24357623

  3. MegaSNPHunter: a learning approach to detect disease predisposition SNPs and high level interactions in genome wide association study

    Xue Hong

    2009-01-01

    Full Text Available Abstract Background The interactions of multiple single nucleotide polymorphisms (SNPs are highly hypothesized to affect an individual's susceptibility to complex diseases. Although many works have been done to identify and quantify the importance of multi-SNP interactions, few of them could handle the genome wide data due to the combinatorial explosive search space and the difficulty to statistically evaluate the high-order interactions given limited samples. Results Three comparative experiments are designed to evaluate the performance of MegaSNPHunter. The first experiment uses synthetic data generated on the basis of epistasis models. The second one uses a genome wide study on Parkinson disease (data acquired by using Illumina HumanHap300 SNP chips. The third one chooses the rheumatoid arthritis study from Wellcome Trust Case Control Consortium (WTCCC using Affymetrix GeneChip 500K Mapping Array Set. MegaSNPHunter outperforms the best solution in this area and reports many potential interactions for the two real studies. Conclusion The experimental results on both synthetic data and two real data sets demonstrate that our proposed approach outperforms the best solution that is currently available in handling large-scale SNP data both in terms of speed and in terms of detection of potential interactions that were not identified before. To our knowledge, MegaSNPHunter is the first approach that is capable of identifying the disease-associated SNP interactions from WTCCC studies and is promising for practical disease prognosis.

  4. The Application of GGE Biplot Analysis for Evaluatng Test Locations and Mega-Environment Investigation of Cotton Regional Trials

    XU Nai-yin; Fok Michel; ZHANG Guo-wei; LI Jian; ZHOU Zhi-guo

    2014-01-01

    In the process to the marketing of cultivars, identiifcation of superior test locations within multi-environment variety trial schemes is of critical relevance. It is relevant to breeding organizations as well as to governmental organizations in charge of cultivar registration. Where competition among breeding companies exists, effective and fair multi-environment variety trials are of utmost importance to motivate investment in breeding. The objective of this study was to use genotype main effect plus genotype by environment interaction (GGE) biplot analysis to evaluate test locations in terms of discrimination ability, representativeness and desirability, and to investigate the presence of multiple mega-environments in cotton production in the Yangtze River Valley (YaRV), China. Four traits (cotton lint yield, ifber length, lint breaking tenacity, micronaire) and two composite selection indices were considered. It was found that the assumption of a single mega-environment in theYaRV for cotton production does not hold. The YaRV consists of three cotton mega-environments: a main one represented by 11 locations and two minor ones represented by two test locations each. This demands that the strategy of cotton variety registration or recommendation must be adjusted. GGE biplot analysis has also led to the identiifcation of test location superior for cotton variety evaluation. Although test location desirable for selecting different traits varied greatly, Jinzhou, Hubei Province, China, was found to be desirable for selecting for all traits considered while Jianyang, SichuanProvince, China, was found to be desirable for none.

  5. MegaMiner: A Tool for Lead Identification Through Text Mining Using Chemoinformatics Tools and Cloud Computing Environment.

    Karthikeyan, Muthukumarasamy; Pandit, Yogesh; Pandit, Deepak; Vyas, Renu

    2015-01-01

    Virtual screening is an indispensable tool to cope with the massive amount of data being tossed by the high throughput omics technologies. With the objective of enhancing the automation capability of virtual screening process a robust portal termed MegaMiner has been built using the cloud computing platform wherein the user submits a text query and directly accesses the proposed lead molecules along with their drug-like, lead-like and docking scores. Textual chemical structural data representation is fraught with ambiguity in the absence of a global identifier. We have used a combination of statistical models, chemical dictionary and regular expression for building a disease specific dictionary. To demonstrate the effectiveness of this approach, a case study on malaria has been carried out in the present work. MegaMiner offered superior results compared to other text mining search engines, as established by F score analysis. A single query term 'malaria' in the portlet led to retrieval of related PubMed records, protein classes, drug classes and 8000 scaffolds which were internally processed and filtered to suggest new molecules as potential anti-malarials. The results obtained were validated by docking the virtual molecules into relevant protein targets. It is hoped that MegaMiner will serve as an indispensable tool for not only identifying hidden relationships between various biological and chemical entities but also for building better corpus and ontologies. PMID:26138567

  6. The Chief Resident Role in Emergency Medicine Residency Programs

    Hafner, John W. Jr., MD, MPH

    2010-05-01

    Full Text Available Study Objectives: Although other specialties have examined the role of the chief resident (CR, the role and training of the emergency medicine (EM CR has largely been undefined.Methods: A survey was mailed to all EM CRs and their respective program directors (PD in 124 EM residency programs. The survey consisted of questions defining demographics, duties of the typical CR, and opinions regarding the level of support and training received. Multiple choice, Likert scale (1 strong agreement, 5 strong disagreement and short-answer responses were used. We analyzed associations between CR and PD responses using Chi-square, Student’s T and Mann-Whitney U tests.Results: Seventy-six percent of CRs and 65% of PDs responded and were similar except for age (31 vs. 42 years; p<0.001. CR respondents were most often male, in year 3 of training and held the position for 12 months. CRs and PDs agreed that the assigned level of responsibility is appropriate (2.63 vs. 2.73, p=0.15; but CRs underestimate their influence in the residency program (1.94 vs. 2.34, p=0.002 and the emergency department (2.61 vs. 3.03, p=0.002. The majority of CRs (70% and PDs (77% report participating in an extramural training program, and those CRs who participated in training felt more prepared for their job duties (2.26 vs. 2.73; p=0.03.Conclusion: EM CRs feel they have appropriate job responsibility but believe they are less influential in program and department administration than PD respondents. Extramural training programs for incoming CRs are widely used and felt to be helpful. [West J Emerg Med. 2010; 11(2:120-125.

  7. GeneGuard: A modular plasmid system designed for biosafety.

    Wright, Oliver; Delmans, Mihails; Stan, Guy-Bart; Ellis, Tom

    2015-03-20

    Synthetic biology applications in biosensing, bioremediation, and biomining envision the use of engineered microbes beyond a contained laboratory. Deployment of such microbes in the environment raises concerns of unchecked cellular proliferation or unwanted spread of synthetic genes. While antibiotic-resistant plasmids are the most utilized vectors for introducing synthetic genes into bacteria, they are also inherently insecure, acting naturally to propagate DNA from one cell to another. To introduce security into bacterial synthetic biology, we here took on the task of completely reformatting plasmids to be dependent on their intended host strain and inherently disadvantageous for others. Using conditional origins of replication, rich-media compatible auxotrophies, and toxin-antitoxin pairs we constructed a mutually dependent host-plasmid platform, called GeneGuard. In this, replication initiators for the R6K or ColE2-P9 origins are provided in trans by a specified host, whose essential thyA or dapA gene is translocated from a genomic to a plasmid location. This reciprocal arrangement is stable for at least 100 generations without antibiotic selection and is compatible for use in LB medium and soil. Toxin genes ζ or Kid are also employed in an auxiliary manner to make the vector disadvantageous for strains not expressing their antitoxins. These devices, in isolation and in concert, severely reduce unintentional plasmid propagation in E. coli and B. subtilis and do not disrupt the intended E. coli host's growth dynamics. Our GeneGuard system comprises several versions of modular cargo-ready vectors, along with their requisite genomic integration cassettes, and is demonstrated here as an efficient vector for heavy-metal biosensors. PMID:24847673

  8. Novel plasmid conferring kanamycin and tetracycline resistance in turkey-derived Campylobacter jejuni strain 11601MD

    In Campylobacter spp., resistance to the antibiotics kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095 bp.) harboring tet(O) was identified in...

  9. Usefulness of plasmid profiles for differentiation of Shigella isolates in Bangladesh.

    Tacket, C O; Shahid, N.; Huq, M I; Alim, A R; Cohen, M L

    1984-01-01

    We studied the plasmid profiles of 136 Shigella isolates in Bangladesh to determine whether plasmid profiles could be used for differentiation of strains for epidemiological studies. Many different plasmid patterns were observed within each species, indicating that many genetically different strains of Shigella are responsible for illness in Bangladesh.

  10. Mobilization of a Sym plasmid from a fast-growing cowpea Rhizobium strain.

    Morrison, N.A.; Cen, Y H; Chen, H.C.; Plazinski, J; Ridge, R; Rolfe, B G

    1984-01-01

    A large Sym plasmid from a fast-growing cowpea Rhizobium species was made mobilizable by cointegration with plasmid pSUP1011, which carries the oriT region of RP4. This mobilizable Sym plasmid was transferred to a number of Rhizobium strains, in which nodulation and nitrogen fixation functions for symbiosis with plants of the cowpea group were expressed.

  11. Sustainable urban transport indicators: tool for evaluating transport sustainability in the mega cities of Pakistan

    Urban Transport is an important sector to accomplish the goal of sustainable development in Pakistan. This is important because of the high growth of the transport sector's energy consumption, road crashes and greenhouse gas emissions. This becomes significant in the Pakistani cities where motor vehicle fleet is growing at two to three times the rate of population. Transport Policies has resulted high growth of urban road traffic, increasing air and noise pollution throughout the country. This situation raised the question how to achieve sustainable urban transport in the mega cities of Pakistan? Development of sustainable urban transport indicators will provide an opportunity to analyze current transport policies to assess Pakistan progress towards or away from sustainability. Medium Term Development Framework (2005-10) has selected to analyze against establish sustainable urban transport indicators for Pakistan. On the basis of analysis, it has found that MWF has tried to address transport problem in a piecemeal manner, rather than adopting a holistic approach. Implementing MTDF policies on transport is not fully matched with a long term commitment to achieving sustainable development in Pakistan. (author)

  12. A Miocene hyperdiverse crocodylian community reveals peculiar trophic dynamics in proto-Amazonian mega-wetlands.

    Salas-Gismondi, Rodolfo; Flynn, John J; Baby, Patrice; Tejada-Lara, Julia V; Wesselingh, Frank P; Antoine, Pierre-Olivier

    2015-04-01

    Amazonia contains one of the world's richest biotas, but origins of this diversity remain obscure. Onset of the Amazon River drainage at approximately 10.5 Ma represented a major shift in Neotropical ecosystems, and proto-Amazonian biotas just prior to this pivotal episode are integral to understanding origins of Amazonian biodiversity, yet vertebrate fossil evidence is extraordinarily rare. Two new species-rich bonebeds from late Middle Miocene proto-Amazonian deposits of northeastern Peru document the same hyperdiverse assemblage of seven co-occurring crocodylian species. Besides the large-bodied Purussaurus and Mourasuchus, all other crocodylians are new taxa, including a stem caiman-Gnatusuchus pebasensis-bearing a massive shovel-shaped mandible, procumbent anterior and globular posterior teeth, and a mammal-like diastema. This unusual species is an extreme exemplar of a radiation of small caimans with crushing dentitions recording peculiar feeding strategies correlated with a peak in proto-Amazonian molluscan diversity and abundance. These faunas evolved within dysoxic marshes and swamps of the long-lived Pebas Mega-Wetland System and declined with inception of the transcontinental Amazon drainage, favouring diversification of longirostrine crocodylians and more modern generalist-feeding caimans. The rise and demise of distinctive, highly productive aquatic ecosystems substantially influenced evolution of Amazonian biodiversity hotspots of crocodylians and other organisms throughout the Neogene. PMID:25716785

  13. Application of Proton Deflectometry to Z-Pinch Plasma Systems at the Mega-Ampere Scale

    Mariscal, Derek; McGuffey, Chris; Valenzuela, Julio; Wei, Mingsheng; Beg, Farhat; Presura, Radu; Haque, Showera; Arias, Angel; Covington, Aaron; Sawada, Hiroshi; Chittenden, Jeremy

    2013-10-01

    Measuring magnetic fields in z-pinch plasmas is challenging. Typical laser-probing diagnostics are limited by the critical density and large density gradients, while electrical diagnostics have limited spatial resolution. We report the first demonstration of proton deflectometry of z-pinch plasma systems at the mega-ampere scale. The proton beam was produced using the 10J 0.3ps Leopard laser and coupled to z-pinch plasma produced by Zebra, a 1MA pulsed-power driver at the Nevada Terawatt Facility. The magnetic field distorted the proton beam profile, which was recorded on radiochromic film. The experimental data was compared against integrated modeling using the resistive MHD code, Gorgon, for Z-pinch plasmas, in combination with the hybrid PIC code, LSP, for proton-beam trajectory tracking. This comparison provided the field and current configuration for various plasma loads, including wire and foil z-pinches. Funded by the NSF/DoE Partnership in Basic Plasma Scienceand En- gineering under contracts DE-SC-0001992 / PHY-0903876. Use of the Nevada Terawatt Facility was supported by the US DOE, NNSA, under Contract No. DE-FC52-06NA27616.

  14. Commissioning and clinical implementation of a mega-voltage cone beam CT system for treatment localization

    The improvement in conformal radiotherapy techniques with steep dose gradients has allowed for the delivery of higher doses to a tumor volume while maintaining the sparing of surrounding normal tissue. In this situation, verification of patient setup and evaluation of internal organ motion just prior to radiation delivery is a crucial step. To this end, several volumetric image-guided techniques have been developed for patient localization, such as the Siemens MVision mega-voltage cone beam CT (MV-CBCT) system. In this work, the commissioning and clinical implementation of the MVision system is presented. The geometry and gain calibration procedures for the system are described, and guidelines for quality assurance procedures are provided. Different MV-CBCT clinical protocols, ranging from daily to weekly image-guidance, which includes image acquisition, reconstruction, registration with planning CT, and treatment couch offsets corrections, were commissioned. The image quality characteristics of the MVision system were measured and assessed qualitatively and quantitatively, including the image noise and uniformity, low-contrast resolution, and spatial resolution. Furthermore, the image reconstruction and registration software was evaluated. Data show that a 2 cm large object with 1% electron density contrast can be detected with the MVision system with 10 cGy at isocenter and that the registration software is accurate within 2 mm in the anterior-posterior, left-right, and superior-inferior directions

  15. Expo Pakistan 2005 - the First Ever Mega Showcase of Pakistani Products

    Liu Yun

    2005-01-01

    @@ The First-ever Mega Showcase of Pakistani products for Global Mar-ket, Expo 2005 is being held in Karachi from February 2-5, 2005.This will be the largest ever interna-tional commercial event in Pakistan with about 600 exhibitors of Paki-stani goods and services displaying their products providing opportuni-ties for joint ventures and investment,besides the exhibition. Thus it would be an ideal one-stop sourcing event,showcasing the premium and value-priced products of Pakistan. It brings out the best of Pakistan congregat-ing the buyers and sellers at one place giving them an opportunity to establish new busi-ness alliances in trade, joint ventures and business investments. This exhibition enjoys the full support of the Government and pri-vate sector. The Technical Session and Con-ferences held during Expo Pakistan 2005,will give the participants an opportunity to understand the sectoral and overall opportu-nities that Pakistan offers.

  16. Defining temporal spatial patterns of mega city Istanbul to see the impacts of increasing population.

    Sanli, Fusun Balik; Balcik, Filiz Bektas; Goksel, Cigdem

    2008-11-01

    Rapid land use change has taken place over the last few decades in Istanbul. As most of the metropolitan areas, Istanbul faces increasing problems connected to increasing population and urbanisation. In this study, temporal changes of Istanbul's land use/cover were defined using remotely sensed data and post classification change detection method. For the aim of the study, relevant information was derived from different dated Landsat Thematic Mapper (TM) satellite data by using Unsupervised Iterative Self-Organizing Data Analysis Technique (ISODATA) and results were examined with matrix analysis method. Ground truth data were used for the classification and accuracy assessment of the classification. Temporal changes of land use/cover classes of the mega city Istanbul between the years of 1992, 1997 and 2005 were examined for the management and decision making process. Landsat TM images were classified into six land use/cover types: forest-green area, bare land, water surface, road, urban area, and mining area. The results show that urban areas and road categories are increased greatly by 13,630 and 5,018ha, respectively, but forest-green areas decreased by 77,722ha over 13years between 1992 and 2005. The reason for the decrease in green areas is mainly because of development of unplanned urbanization and unavoidable migration. PMID:18157736

  17. A mega-analysis of genome-wide association studies for major depressive disorder.

    Ripke, Stephan; Wray, Naomi R; Lewis, Cathryn M; Hamilton, Steven P; Weissman, Myrna M; Breen, Gerome; Byrne, Enda M; Blackwood, Douglas H R; Boomsma, Dorret I; Cichon, Sven; Heath, Andrew C; Holsboer, Florian; Lucae, Susanne; Madden, Pamela A F; Martin, Nicholas G; McGuffin, Peter; Muglia, Pierandrea; Noethen, Markus M; Penninx, Brenda P; Pergadia, Michele L; Potash, James B; Rietschel, Marcella; Lin, Danyu; Müller-Myhsok, Bertram; Shi, Jianxin; Steinberg, Stacy; Grabe, Hans J; Lichtenstein, Paul; Magnusson, Patrik; Perlis, Roy H; Preisig, Martin; Smoller, Jordan W; Stefansson, Kari; Uher, Rudolf; Kutalik, Zoltan; Tansey, Katherine E; Teumer, Alexander; Viktorin, Alexander; Barnes, Michael R; Bettecken, Thomas; Binder, Elisabeth B; Breuer, René; Castro, Victor M; Churchill, Susanne E; Coryell, William H; Craddock, Nick; Craig, Ian W; Czamara, Darina; De Geus, Eco J; Degenhardt, Franziska; Farmer, Anne E; Fava, Maurizio; Frank, Josef; Gainer, Vivian S; Gallagher, Patience J; Gordon, Scott D; Goryachev, Sergey; Gross, Magdalena; Guipponi, Michel; Henders, Anjali K; Herms, Stefan; Hickie, Ian B; Hoefels, Susanne; Hoogendijk, Witte; Hottenga, Jouke Jan; Iosifescu, Dan V; Ising, Marcus; Jones, Ian; Jones, Lisa; Jung-Ying, Tzeng; Knowles, James A; Kohane, Isaac S; Kohli, Martin A; Korszun, Ania; Landen, Mikael; Lawson, William B; Lewis, Glyn; Macintyre, Donald; Maier, Wolfgang; Mattheisen, Manuel; McGrath, Patrick J; McIntosh, Andrew; McLean, Alan; Middeldorp, Christel M; Middleton, Lefkos; Montgomery, Grant M; Murphy, Shawn N; Nauck, Matthias; Nolen, Willem A; Nyholt, Dale R; O'Donovan, Michael; Oskarsson, Högni; Pedersen, Nancy; Scheftner, William A; Schulz, Andrea; Schulze, Thomas G; Shyn, Stanley I; Sigurdsson, Engilbert; Slager, Susan L; Smit, Johannes H; Stefansson, Hreinn; Steffens, Michael; Thorgeirsson, Thorgeir; Tozzi, Federica; Treutlein, Jens; Uhr, Manfred; van den Oord, Edwin J C G; Van Grootheest, Gerard; Völzke, Henry; Weilburg, Jeffrey B; Willemsen, Gonneke; Zitman, Frans G; Neale, Benjamin; Daly, Mark; Levinson, Douglas F; Sullivan, Patrick F

    2013-04-01

    Prior genome-wide association studies (GWAS) of major depressive disorder (MDD) have met with limited success. We sought to increase statistical power to detect disease loci by conducting a GWAS mega-analysis for MDD. In the MDD discovery phase, we analyzed more than 1.2 million autosomal and X chromosome single-nucleotide polymorphisms (SNPs) in 18 759 independent and unrelated subjects of recent European ancestry (9240 MDD cases and 9519 controls). In the MDD replication phase, we evaluated 554 SNPs in independent samples (6783 MDD cases and 50 695 controls). We also conducted a cross-disorder meta-analysis using 819 autosomal SNPs with Pgenetic effects typical for complex traits. Therefore, we were unable to identify robust and replicable findings. We discuss what this means for genetic research for MDD. The 3p21.1 MDD-BIP finding should be interpreted with caution as the most significant SNP did not replicate in MDD samples, and genotyping in independent samples will be needed to resolve its status. PMID:22472876

  18. Magneto-Rayleigh-Taylor experiments on a MegaAmpere linear transformer driver

    Zier, J. C.; Gilgenbach, R. M.; Chalenski, D. A.; Lau, Y. Y.; French, D. M.; Gomez, M. R.; Patel, S. G.; Rittersdorf, I. M.; Steiner, A. M.; Weis, M.; Zhang, P.; Mazarakis, M.; Cuneo, M. E.; Lopez, M.

    2012-03-01

    Experiments have been performed on a nominal 100 ns rise time, MegaAmpere (MA)-class linear transformer driver to explore the magneto-Rayleigh-Taylor (MRT) instability in planar geometry. Plasma loads consisted of ablated 400 nm-thick, 1 cm-wide aluminum foils located between two parallel-plate return-current electrodes. Plasma acceleration was adjusted by offsetting the position of the foil (cathode) between the anode plates. Diagnostics included double-pulse, sub-ns laser shadowgraphy, and machine current B-dot loops. Experimental growth rates for MRT on both sides of the ablated aluminum plasma slab were comparable for centered-foils. The MRT growth rate was fastest (98 ns e-folding time) for the foil-offset case where there was a larger magnetic field to accelerate the plasma. Other cases showed slower growth rates with e-folding times of about ˜106 ns. An interpretation of the experimental data in terms of an analytic MRT model is attempted.

  19. Deep imaging of the shell elliptical galaxy NGC 3923 with MegaCam

    Bílek, M.; Cuillandre, J.-C.; Gwyn, S.; Ebrová, I.; Bartošková, K.; Jungwiert, B.; Jílková, L.

    2016-04-01

    Context. The elliptical galaxy NGC 3923 is known to be surrounded by a number of stellar shells, probable remnants of an accreted galaxy. Despite its uniqueness, the deepest images of its outskirts come from the 1980s. On the basis of the modified Newtonian dynamics (MOND), it has recently been predicted that a new shell lies in this region. Aims: We obtain the deepest image ever of the galaxy, map the tidal features in it, and search for the predicted shell. Methods: The image of the galaxy was taken by the MegaCam camera at the Canada-France-Hawaii Telescope in the g'-band. It reached the surface-brightness limit of 29 mag arcsec-2. In addition, we reanalyzed an archival HST image of the galaxy. Results: We detected up to 42 shells in NGC 3923. This is by far the highest number among all shell galaxies. We present the description of the shells and other tidal features in the galaxy. A probable progenitor of some of these features was discovered. The shell system likely originates from two or more progenitors. The predicted shell was not detected, but the new image revealed that the prediction was based on incorrect assumptions and poor data. The reduced images (FITS files) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/588/A77

  20. Physico-chemical characteristics of Jharkhand and West Bengal thermal springs along SONATA mega lineament, India

    Hemant K Singh; D Chandrasekharam; O Vaselli; G Trupti; B Singh; Aref Lashin; Nassir Al Arifi

    2015-03-01

    The chemical and isotopic compositions of thermal springs located along the Son–Narmada–Tapti (SONATA) mega lineament in central India have been investigated. The issuing temperatures of the thermal waters vary from 31° to 89°C for the thermal springs and 24° to 25°C for the cold springs. These thermal springs are located on the Archean Chotanagpur Gneissic Complex (CGC) in the eastern part of peninsular India. The thermal springs are mostly alkaline in nature with pH varying from 7.5 to 9.5. Piper diagram suggests that the chemistry of the thermal waters is compatible with the granitic host rocks through which the waters circulate. Mineral saturation index suggests that the thermal waters are saturated with cristobalite and quartz at lower temperatures (less than ∼130 to 150°C), and calcite and forsterite at higher temperatures (∼160° to 250°C). The estimated reservoir temperature based on chemical geothermometers is in the range of 132°–265°C, which favours a medium enthalpy geothermal system. Oxygen isotope fractionation of Bakreswar and Tantloi thermal springs highlights a higher reservoir temperature than estimated by chemical geothermometer. Positive gravity anomalies over Bakreswar and Tantloi areas strongly suggest a basement/mantle upliftment or mafic intrusion which could account for the heat source close to the surface. However, the large negative gravity anomaly depression around the Surajkund and Katkamsandi thermal springs indicates presence of deep seated faults.

  1. Evidence of ENSO mega-drought triggered collapse of prehistory Aboriginal society in northwest Australia

    McGowan, Hamish; Marx, Samuel; Moss, Patrick; Hammond, Andrew

    2012-11-01

    The Kimberley region of northwest Australia contains one of the World's largest collections of rock art characterised by two distinct art forms; the fine featured anthropomorphic figures of the Gwion Gwion or Bradshaw paintings, and broad stroke Wandjina figures. Luminescence dating of mud wasp nests overlying Gwion Gwion paintings has confirmed an age of at least 17,000 yrs B.P. with the most recent dates for these paintings from around the mid-Holocene (5000 to 7000 yrs B.P.). Radiocarbon dating indicates that the Wandjina rock art then emerged around 3800 to 4000 yrs B.P. following a hiatus of at least 1200 yrs. Here we show that a mid-Holocene ENSO forced collapse of the Australian summer monsoon and ensuing mega-drought spanning approximately 1500 yrs was the likely catalyst of this change in rock art. The severity of the drought we believe was enhanced through positive feedbacks triggered by change in land surface condition and increased aerosol loading of the atmosphere leading to a weakening or failure of monsoon rains. This confirms that pre-historic aboriginal cultures experienced catastrophic upheaval due to rapid natural climate variability and that current abundant seasonal water supplies may fail again if significant change in ENSO occurs.

  2. Strong motion simulation for mega-earthquakes in northern Chile from several potential rupture scenarios

    Otarola, C., Sr.; Ruiz, S.

    2015-12-01

    Large earthquakes happened recently in Northern Chile: Tocopilla 2007 (Mw 7.7) and Iquique 2014 (Mw 8.1). Both events were well recorded by strong motion networks, provided valuable information to be used for forward predictions of ground motions records. In traditional finite-fault stochastic method one generic horizontal component of the synthetic accelerograms are obtained considering only incident vertical rays of S waves. The observed strong motion records show important differences among horizontal and vertical components. Then in order to generate 3 components of strong motion we improve this method to simulate the arrive to free surface of the P, SV and SH waves. We considered the incident and azimuth angles of direct seismic rays propagating for a layered velocity model including the free surface and energy partition. We validate our strong ground motion simulation by comparing the synthetic and observed data in a wide frequency range (0.1-20 Hz) for the Tocopilla (2007) and Iquique (2014) earthquakes. Finally, we use this method to propose the synthetic accelerograms for several potential rupture scenarios for mega-earthquakes in northern Chile, these scenarios were proposed considering coupling models and the historical earthquake records. The results show large PGA values near 1 g, for station located on hard rock. An important trade - off between the PGA and the proposed slip distribution was observed. The maximum slip distribution located in deeper seismogenic contact produce the large PGA in the nearest stations.

  3. Assessment of injury from the MEGA BORG oil spill: A case of cooperative damage assessment

    The tanker MEGA BORG exploded while lightering about 60 miles offshore of Galveston, Texas on 8 June 1990. The explosion was followed by a spectacular fire and major release of Angolan crude. Up to 5.1 million gallons of the 41 million gallon cargo was lost to the sea or burning over a period of seven days. Vessel interests took responsibility for the spill and employed skimming and dispersive cleanup techniques. It is estimated that approximately 126 gallons ultimately reached shore in western Louisiana. Within a day of the explosion, the Norwegian vessel owner, French cargo owner and the Norwegian vessel insurer entered into discussion with the Texas Water Commission and the National Oceanic and Atmospheric Administration regarding damage assessment options. Within the next two days the owners agreed to fund and participate in a cooperative preliminary assessment of environmental injury. Five projects were funded to determine whether there was sufficient injury to justify the completion of a full natural resource damage assessment: (1) Fate of spilled oil; (2) Effects on shrimp fishery; (3) Effects on marine mammals and turtles; (4) Effects of beach oiling and (5) Effects on recreation. Funds were also provided for report preparation and project management. Several issues of major concern were considered by vessel interests prior to agreement. Many of these issues are common to consideration of cooperative assessments and may be critical importance to future incidents particularly if the damage assessment regulations developed pursuant to the Oil Pollution Act encourage cooperative responses

  4. Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe.

    Walkden, N R; Adamek, J; Allan, S; Dudson, B D; Elmore, S; Fishpool, G; Harrison, J; Kirk, A; Komm, M

    2015-02-01

    The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ∼1 kV/m and increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the ER measurements. The uncertainty is most significant in the electric field well inside the separatrix. The electric field is used to estimate toroidal and poloidal rotation velocities from E × B motion. This paper further demonstrates the ability of the ball pen probe to make valuable and important measurements in the boundary plasma of a tokamak. PMID:25725845

  5. A case with oto-spondylo-mega-epiphyseal-dysplasia (OSMED): the clinical recognition and differential diagnosis.

    Karaer, Kadri; Rosti, Rasim Ozgür; Torun, Deniz; Sanal, Hatice Tuba; Bahçe, Muhterem; Güran, Sefik

    2011-01-01

    The oto-spondylo-mega-epiphyseal-dysplasia (OSMED) phenotype is an autosomal recessive trait that is a skeletal dysplasia with the hallmark findings of limb shortening, multiple skeletal and radiological abnormalities, mid-face hypoplasia with a flat nasal bridge, small upturned nasal tip, and sensorineural hearing loss. A 3.5-year-old girl born to consanguineous Turkish parents had characteristic facial features at birth: mid-face hypoplasia, mild hypertelorism, upslanting palpebral fissures, prominent supraorbital ridges, depressed nasal bridge, small upturned nasal tip, long philtrum, and micrognathia. Radiological examination at three years of age revealed large flaring metaphyses and wide flat epiphyses. The humerus and femur showed the characteristic dumbbell shape. She had bilateral hearing loss with no ophthalmologic findings. There is continuing debate over the clinical overlap and differential diagnosis of OSMED syndrome. The patient was examined considering Weissenbacher-Zweymuller, Stickler type 3, Marshall syndrome, and Kniest dysplasia as possible differential diagnoses. We believe that the presented patient clinically manifested features of OSMED syndrome. We would like to point out that the management of OSMED calls for a coordinated multidisciplinary approach. PMID:21980822

  6. Microbiota do megaesôfago e carcinogênese Megaesophagus microbiota and carcinogenesis

    Denis Pajecki

    2003-03-01

    Full Text Available INTRODUÇÃO: O risco de desenvolvimento de carcinoma esofágico em portadores de megaesôfago é 33 vezes superior ao da população em geral. Possível explicação para este fenômeno poderia estar relacionada à produção de compostos N-nitrosos na luz do órgão, a partir da transformação de nitratos da dieta em nitritos, mediada por bactérias em suspensão no líquido de estase e com o contato crônico destes carcinógenos com a mucosa esofágica. OBJETIVO: Analisar a microbiota esofágica em pacientes portadores de megaesôfago de etiologia chagásica, com especial atenção para a presença de bactérias com capacidade de redução de nitratos. CASUÍSTICA: Foram estudados prospectivamente 15 pacientes portadores de megaesôfago chagásico com idades variando de 28 a 73 anos, sendo 9 do sexo feminino e 6 do sexo masculino, que foram divididos em 3 grupos iguais de 5, de acordo com o grau de dilatação do esôfago, segundo a classificação de Rezende et al. (Grau I, Grau II e Grau III. MÉTODO: A coleta do líquido de estase para estudo microbiológico era realizada através de sonda de Levine nº 14, que era passada pela boca, por dentro de uma cânula de intubação orotraqueal nº 7,5, mantendo-se sua extremidade escondida, a fim de evitar sua contaminação. RESULTADOS: Foram obtidas 93,3% de culturas positivas com grande variedade de microrganismos e predomínio de aeróbios Gram-positivos e anaeróbios. As concentrações de microrganismos foram tanto maiores, quanto maior o grau de dilatação do esôfago. Entre os microrganismos encontrados, o Staphylococcus sp, Corynebacterium sp, Peptostreptococcus sp e a Veillonella sp foram aqueles identificados como tendo a capacidade de redução de nitratos a nitritos. CONCLUSÃO: No megaesôfago chagásico há bactérias na luz do órgão com capacidade de redução de nitratos da dieta, passo importante na produção de compostos N-nitrosos.BACKGROUND: The risk of development of

  7. Observational study of aerosol hygroscopic growth factors over rural area near Beijing mega-city

    X. L. Pan

    2009-02-01

    Full Text Available We investigated aerosol hygroscopic growth property and its influence on scattering coefficient using M9003 nephelometers in coupling with a relative humidity controlled inlet system at a rural site near Beijing mega-city (Jingjintang from 24th April to15th May 2006. Inlet relative humidity was controlled in an increasing range of 40%–90% while the aerosol hygroscopic growth factor, f(RH=80%, varied in a range of 1.07–2.35 during the measurement. Estimated periodic mean values of aerosol hygroscopic growth factors are 1.27–1.34, 1.17–1.23, 1.55–1.59 and 2.33–2.48 for clean, dust, urban pollution and mixed pollution periods respectively. An examination of chemical composition of daily filter samples highlighted that aerosol hygroscopicity was generally enhanced with the increasing ratio of ammonium sulfate (AS to organic matter (OMC. Furthermore, strong hygroscopic organic aerosols were observed on 11th (f(RH=80%=2.23 and 15th (f(RH=80%=2.21 of May with organic carbon proportions of PM2.1 reaching 42.3% and 43.0% respectively. Back-trajectory analysis indicated that solar radiation and vertical convective movement along the air mass pathway might strongly influence the hygroscopic properties of organic matter.

  8. Profile measurements in the plasma edge of mega amp spherical tokamak using a ball pen probe

    The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature, and radial electric field on the Mega Amp Spherical Tokamak. The potential profile measured by the BPP is shown to significantly differ from the floating potential both in polarity and profile shape. By combining the BPP potential and the floating potential, the electron temperature can be measured, which is compared with the Thomson scattering (TS) diagnostic. Excellent agreement between the two diagnostics is obtained when secondary electron emission is accounted for in the floating potential. From the BPP profile, an estimate of the radial electric field is extracted which is shown to be of the order ∼1 kV/m and increases with plasma current. Corrections to the BPP measurement, constrained by the TS comparison, introduce uncertainty into the ER measurements. The uncertainty is most significant in the electric field well inside the separatrix. The electric field is used to estimate toroidal and poloidal rotation velocities from E × B motion. This paper further demonstrates the ability of the ball pen probe to make valuable and important measurements in the boundary plasma of a tokamak

  9. Sexual Health Education: A Psychiatric Resident's Perspective

    Waineo, Eva; Arfken, Cynthia L.; Morreale, Mary K.

    2010-01-01

    Objective: This report discusses psychiatric residents' perceptions of sexual health education and their opinions regarding curricular improvements. Methods: An anonymous, web-based survey was sent to residents in one general psychiatry program (N = 33). The response rate was 69.7%. Results: Residents reported inadequate experience in multiple…

  10. Suicidal Thoughts Among Medical Residents with Burnout

    van der Heijden, Frank; Dillingh, Gea; Bakker, Arnold; Prins, Jelle

    2008-01-01

    Objectives: Recent research showed that medical residents have a high risk for developing burnout. The present study investigates the prevalence of burnout and its relationship with suicidal thoughts among medical residents. Methods: All Dutch medical residents (n = 5126) received a self-report ques

  11. 38 CFR 51.110 - Resident assessment.

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Resident assessment. 51...) PER DIEM FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.110 Resident assessment. The... condition a comprehensive, accurate, standardized, reproducible assessment of each resident's...

  12. Negotiations of Acknowledgement among Middle Class Residents

    Andersen, Nina Blom

    2013-01-01

    The article presents an analysis of communication processes between residents, between residents and people in the broader societal context as well as of media coverage of a fireworks disaster in a Danish suburb. It demonstrates how residents (all members of the Danish middle class) were able to...

  13. 38 CFR 51.70 - Resident rights.

    2010-07-01

    ... live in the same facility and both spouses consent to the arrangement. (n) Self-Administration of Drugs... FOR NURSING HOME CARE OF VETERANS IN STATE HOMES Standards § 51.70 Resident rights. The resident has a...; (iii) Physicians of the resident's choice (to provide care in the nursing home, physicians must...

  14. Plasmid vectors for Xylella fastidiosa utilizing a toxin-antitoxin system for plasmid stability in the absence of antibiotic selection

    The phytopathogen Xylella fastidiosa causes disease in a variety of important crop and landscape plants. Functional genetic studies have led to a broader understanding of virulence mechanisms used by this pathogen in the grapevine host. Plasmid shuttle vectors are important tools in studies of bacte...

  15. Cloning, sequencing, and expression in Escherichia coli of lcnB, a third bacteriocin determinant from the lactococcal bacteriocin plasmid p9B4-6.

    van Belkum, Marco J.; Kok, Jan; Venema, Gerhardus

    1992-01-01

    On the bacteriocin plasmid p9B4-6 of Lactococcus lactis subsp. cremoris 9B4, a third bacteriocin determinant was identified. The genes encoding bacteriocin production and immunity resided on a 1.2-kb CelII-ScaI fragment and were located adjacent to one of two previously identified bacteriocin operons (M. J. van Belkum, B. J. Hayema, R. E. Jeeninga, J. Kok, and G. Venema, Appl. Environ. Microbiol. 57:492-498, 1991). The fragment was sequenced and analyzed by deletion and mutation analyses. The...

  16. Expansion of a Plasmid Classification System for Gram-Positive Bacteria and Determination of the Diversity of Plasmids in Staphylococcus aureus Strains of Human, Animal, and Food Origins

    Lozano, Carmen; García-Migura, Lourdes; Aspiroz, Carmen; Zarazaga, Myriam; Torres, Carmen; Aarestrup, Frank Møller

    2012-01-01

    An expansion of a previously described plasmid classification was performed and used to reveal the plasmid content of a collection of 92 Staphylococcus aureus strains of different origins. rep genes of other genera were detected in Staphylococcus. S1 pulsed-field gel electrophoresis (PFGE) hybridizations were performed with 18 representative S. aureus strains, and a high number of plasmids of different sizes and organizations were detected.

  17. Role of the 85-Kilobase Plasmid and Plasmid-Encoded Virulence-Associated Protein A in Intracellular Survival and Virulence of Rhodococcus equi

    Giguère, Steeve; Hondalus, Mary K.; Yager, Julie A.; Darrah, Patricia; Mosser, David M.; Prescott, John F.

    1999-01-01

    Rhodococcus equi is a facultative intracellular pathogen of macrophages and a cause of pneumonia in young horses (foals) and immunocompromised people. Isolates of R. equi from pneumonic foals typically contain large, 85- or 90-kb plasmids encoding a highly immunogenic virulence-associated protein (VapA). The objective of this study was to determine the role of the 85-kb plasmid and VapA in the intracellular survival and virulence of R. equi. Clinical isolates containing the plasmid and expres...

  18. Residència canina

    Rafart Roca, Mariola

    2013-01-01

    L’idea principal d’aquest projecte consisteix en la construcció d’una Residència Canina a la localitat de la Torre d’Oristà (Osona), en una zona de proximitat al poble però dins de terreny rústic. La zona estarà composta per cinc grans espais: - Edifici on s’ubicarà: lavabos, oficina, perruqueria canina i magatzem. - Bateria de gosseres. - Sala de maquinària. - Zona de piscina. - Zona d’esbarjo. A més també es modificarà en petita escala l’entorn de la zona, per adapta...

  19. The stb operon balances the requirements for vegetative stability and conjugative transfer of plasmid R388.

    Catherine Guynet

    2011-05-01

    Full Text Available The conjugative plasmid R388 and a number of other plasmids carry an operon, stbABC, adjacent to the origin of conjugative transfer. We investigated the role of the stbA, stbB, and stbC genes. Deletion of stbA affected both conjugation and stability. It led to a 50-fold increase in R388 transfer frequency, as well as to high plasmid loss. In contrast, deletion of stbB abolished conjugation but provoked no change in plasmid stability. Deletion of stbC showed no effect, neither in conjugation nor in stability. Deletion of the entire stb operon had no effect on conjugation, which remained as in the wild-type plasmid, but led to a plasmid loss phenotype similar to that of the R388ΔstbA mutant. We concluded that StbA is required for plasmid stability and that StbA and StbB control conjugation. We next observed the intracellular positioning of R388 DNA molecules and showed that they localize as discrete foci evenly distributed in live Escherichia coli cells. Plasmid instability of the R388ΔΔstbA mutant correlated with aberrant localization of the plasmid DNA molecules as clusters, either at one cell pole, at both poles, or at the cell center. In contrast, plasmid molecules in the R388ΔΔstbB mutant were mostly excluded from the cell poles. Thus, results indicate that defects in both plasmid maintenance and transfer are a consequence of variations in the intracellular positioning of plasmid DNA. We propose that StbA and StbB constitute an atypical plasmid stabilization system that reconciles two modes of plasmid R388 physiology: a maintenance mode (replication and segregation and a propagation mode (conjugation. The consequences of this novel concept in plasmid physiology will be discussed.

  20. Coupling between the Basic Replicon and the Kis-Kid Maintenance System of Plasmid R1: Modulation by Kis Antitoxin Levels and Involvement in Control of Plasmid Replication

    Juan López-Villarejo; Damián Lobato-Márquez; Ramón Díaz-Orejas

    2015-01-01

    kis-kid, the auxiliary maintenance system of plasmid R1 and copB, the auxiliary copy number control gene of this plasmid, contribute to increase plasmid replication efficiency in cells with lower than average copy number. It is thought that Kis antitoxin levels decrease in these cells and that this acts as the switch that activates the Kid toxin; activated Kid toxin reduces copB-mRNA levels and this increases RepA levels that increases plasmid copy number. In support of this model we now repo...

  1. Coupling between the Basic Replicon and the Kis-Kid Maintenance System of Plasmid R1: Modulation by Kis Antitoxin Levels and Involvement in Control of Plasmid Replication

    Juan López-Villarejo

    2015-02-01

    Full Text Available kis-kid, the auxiliary maintenance system of plasmid R1 and copB, the auxiliary copy number control gene of this plasmid, contribute to increase plasmid replication efficiency in cells with lower than average copy number. It is thought that Kis antitoxin levels decrease in these cells and that this acts as the switch that activates the Kid toxin; activated Kid toxin reduces copB-mRNA levels and this increases RepA levels that increases plasmid copy number. In support of this model we now report that: (i the Kis antitoxin levels do decrease in cells containing a mini-R1 plasmid carrying a repA mutation that reduces plasmid copy number; (ii kid-dependent replication rescue is abolished in cells in which the Kis antitoxin levels or the CopB levels are increased. Unexpectedly we found that this coordination significantly increases both the copy number of the repA mutant and of the wt mini-R1 plasmid. This indicates that the coordination between plasmid replication functions and kis-kid system contributes significantly to control plasmid R1 replication.

  2. Studies on the plasmid stability, plasmid copy number and endo(1, 3)(1, 4) b-glucanase production by free and alginate immobilised recombinant saccharomyces cerevisiae cells

    Canavan, Peter D.

    1994-01-01

    A recombinant yeast strain, Saccharomyces cerevisiae DBY746, containing the plasmid pJG317, was grown in a variety of fermentation modes including batch, serial batch and chemostat culture incorporating a wide range of media types Plasmid pJG317 consists of a 2^-denved yeast episomal plasmid containing the gene which encodes for the bacterial enzyme endo (1,3)(1,4) P-glucanase. The concentration of enzyme produced appears to be proportional to the number of plasmid copies per cell. Specific e...

  3. Escherichia coli dnaT gene function is required for pBR322 plasmid replication but not for R1 plasmid replication.

    Masai, H.; Arai, K.

    1989-01-01

    Plasmid pBR322 was unable to replicate in a temperature-sensitive dnaT1 strain at a nonpermissive temperature, whereas a pBR322-derived plasmid carrying the wild-type dnaT+ gene was able to replicate under the same conditions. In contrast to pBR322, plasmid R1 could replicate in the dnaT1 strain at a nonpermissive temperature. In keeping with this finding, in vitro replication of plasmid R1 did not require DnaT protein.

  4. Enterococcus faecalis hemolysin-bacteriocin plasmids belong to the same incompatibility group.

    Colmar, I; Horaud, T

    1987-01-01

    Plasmid pair coexistence was studied both among nine Enterococcus faecalis hemolysin-bacteriocin (Hly-Bcn) plasmids, including pJH2, pAD1, pAM gamma 1, and pIP964, and between pIP964 and five R plasmids. Some of the Hly-Bcn plasmids used were derivatives encoding resistance to erythromycin or tetracycline. The Hly-Bcn plasmids were incompatible with each other; 40 to 100% displacement was observed bilaterally for eight pairs and unilaterally for one pair. In contrast, pIP964 stably coexisted ...

  5. Structural and genetic analyses of a par locus that regulates plasmid partition in Bacillus subtilis.

    Chang, S.; Chang, S Y; Gray, O

    1987-01-01

    The Bacillus plasmid pLS11 partitions faithfully during cell division. Using a partition-deficient plasmid vector, we randomly cloned DNA fragments of plasmid pLS11 and identified the locus that regulates plasmid partition (par) by cis complementation in Bacillus subtilis. The cloned par gene conferred upon the vector plasmid a high degree of segregational stability. The par locus was mapped to a 167-base-pair segment on pLS11, and its nucleotide sequence was determined. The cloned par fragme...

  6. cmp, a cis-acting plasmid locus that increases interaction between replication origin and initiator protein.

    Gennaro, M L; Novick, R P

    1986-01-01

    pT181, a 4.4-kilobase multicopy plasmid of Staphylococcus aureus, encodes a trans-acting initiator protein, RepC, which was rate limiting for replication. Deletions in a 500-base-pair region of the plasmid external to the minimal replicon decreased the ability of the plasmid to compete with a coexisting incompatible plasmid. These deletions, which define a region called cmp (for competition), appeared to affect the interaction of RepC and the plasmid origin of replication. However, in the hom...

  7. Remarkable stability of an instability-prone lentiviral vector plasmid in Escherichia coli Stbl3

    Al-Allaf, Faisal A.; Tolmachov, Oleg E.; Zambetti, Lia Paola; Tchetchelnitski, Viktoria; Mehmet, Huseyin

    2012-01-01

    Large-scale production of plasmid DNA to prepare therapeutic gene vectors or DNA-based vaccines requires a suitable bacterial host, which can stably maintain the plasmid DNA during industrial cultivation. Plasmid loss during bacterial cell divisions and structural changes in the plasmid DNA can dramatically reduce the yield of the desired recombinant plasmid DNA. While generating an HIV-based gene vector containing a bicistronic expression cassette 5′-Olig2cDNA-IRES-dsRed2-3′, we encountered ...

  8. The incC Sequence Is Required for R27 Plasmid Stability

    Tassinari, Eleonora; Aznar, Sonia; Urcola, Imanol; Prieto, Alejandro; Hüttener, Mário; Juárez, Antonio

    2016-01-01

    IncHI plasmids account for multiple antimicrobial resistance in Salmonella and other enterobacterial genera. These plasmids are generally very stable in their bacterial hosts. R27 is the archetype of IncHI1 plasmids. A high percentage of the R27-encoded open reading frames (ORFs) (66.7%) do not show similarity to any known ORFs. We performed a deletion analysis of all non-essential R27 DNA sequences to search for hitherto non-identified plasmid functions that might be required for plasmid sta...

  9. [Plasmids of streptomycetes strains isolated from soils of Ukraine with different anthropogenic loading].

    Luk'ianchuk, V V; Polishchuk, L V; Matseliukh, B P

    2010-01-01

    Screening of plasmid DNA was carried out among 94 streptomycetes cultures which were isolated from the samples of Ukrainian soils with different anthropogenic contamination. Seventeen streptomycetes strains containing plasmid DNA were found. It is established that some cultures contain more than one plasmid (Streptomyces sp.M15, S.sp.T8, S.sp.T19). Depending on a molecular sizes the found plasmids were divided in 2 groups: 3 kb-15 kb, and 30 kb-70 kb. Research of a few morphological and physiological properties of plasmid strains of streptomycetes was carried out. The paper is presented in Ukrainian. PMID:21117293

  10. recE4-Independent Recombination Between Homologous Deoxyribonucleic Acid Segments of Bacillus subtilis Plasmids

    Tanaka, T

    1980-01-01

    A plasmid (pLS104) carrying a tandem repetition of the leu region of the Bacillus subtilis chromosome arose spontaneously from pLS103, which carried a single copy of the leu region. Plasmid preparations from strains harboring pLS104 also contained the original plasmid, pLS103, and, in some preparations, plasmids carrying three or four repetitions of the leu region. These plasmids were shown to be generated by recombination between homologous deoxyribonucleic acid (DNA) segments in the tandeml...

  11. An Improved Method for Including Upper Size Range Plasmids in Metamobilomes

    Norman, Anders; Riber, Leise; Luo, Wenting; Li, Li Li; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

    2014-01-01

    Two recently developed isolation methods have shown promise when recovering pure community plasmid DNA (metamobilomes/plasmidomes), which is useful in conducting culture-independent investigations into plasmid ecology. However, both methods employ multiple displacement amplification (MDA) to ensure...... suitable quantities of plasmid DNA for high-throughput sequencing. This study demonstrates that MDA greatly favors smaller circular DNA elements (<10 Kbp), which, in turn, leads to stark underrepresentation of upper size range plasmids (>10 Kbp). Throughout the study, we used two model plasmids, a 4.4 Kbp...

  12. Tumor induction by Agrobacterium rhizogenes involves the transfer of plasmid DNA to the plant genome

    White, Frank F; Ghidossi, Gina; Gordon, Milton P.; Nester, Eugene W.

    1982-01-01

    The DNA from tumors of Nicotiana glauca initiated by strains of Agrobacterium rhizogenes was shown to contain sequences that are homologous to the root-inducing (Ri) plasmid of the bacterium. Two independently established tumor lines contained a similar portion of the Ri-plasmid. The Ri-plasmid also hybridized to DNA fragments from uninfected N. glauca. A cosmid clone of the Ri-plasmid encompassing the region containing the Ri-plasmid sequences that are stably transferred to the plant also hy...

  13. 2003 survey of Canadian radiation oncology residents

    Purpose: Radiation oncology's popularity as a career in Canada has surged in the past 5 years. Consequently, resident numbers in Canadian radiation oncology residencies are at all-time highs. This study aimed to survey Canadian radiation oncology residents about their opinions of their specialty and training experiences. Methods and Materials: Residents of Canadian radiation oncology residencies that enroll trainees through the Canadian Resident Matching Service were identified from a national database. Residents were mailed an anonymous survey. Results: Eight of 101 (7.9%) potential respondents were foreign funded. Fifty-two of 101 (51.5%) residents responded. A strong record of graduating its residents was the most important factor residents considered when choosing programs. Satisfaction with their program was expressed by 92.3% of respondents, and 94.3% expressed satisfaction with their specialty. Respondents planning to practice in Canada totaled 80.8%, and 76.9% plan to have academic careers. Respondents identified job availability and receiving adequate teaching from preceptors during residency as their most important concerns. Conclusions: Though most respondents are satisfied with their programs and specialty, job availability and adequate teaching are concerns. In the future, limited time and resources and the continued popularity of radiation oncology as a career will magnify the challenge of training competent radiation oncologists in Canada

  14. Public health education for emergency medicine residents.

    Betz, Marian E; Bernstein, Steven L; Gutman, Deborah C; Tibbles, Carrie D; Joyce, Nina R; Lipton, Robert I; Schweigler, Lisa M; Fisher, Jonathan

    2011-10-01

    Emergency medicine (EM) has an important role in public health, but the ideal approach for teaching public health to EM residents is unclear. As part of the national Regional Public Health-Medicine Education Centers-Graduate Medical Education initiative from the CDC and the American Association of Medical Colleges, three EM programs received funding to create public health curricula for EM residents. Curricula approaches varied by residency. One program used a modular, integrative approach to combine public health and EM clinical topics during usual residency didactics, one partnered with local public health organizations to provide real-world experiences for residents, and one drew on existing national as well as departmental resources to seamlessly integrate more public health-oriented educational activities within the existing residency curriculum. The modular and integrative approaches appeared to have a positive impact on resident attitudes toward public health, and a majority of EM residents at that program believed public health training is important. Reliance on pre-existing community partnerships facilitated development of public health rotations for residents. External funding for these efforts was critical to their success, given the time and financial restraints on residency programs. The optimal approach for public health education for EM residents has not been defined. PMID:21961671

  15. STABILITY OF PLASMIDS IN 5 STRAINS OF SALMONELLA MAINTAINED IN STAB CULTURE AT DIFFERENT TEMPERATURES

    Olsen, J. E.; Brown, D. J.; Baggesen, Dorte Lau;

    1994-01-01

    Four strains of Salmonella berta and one of Salm. enteritidis were stored as stab cultures in sugar-free agar at 5 degrees, 22 degrees and 30 degrees C and in 15% glycerol at -80 degrees C. The stability of the plasmid profiles in each of the strains was monitored over a period of 2.5 years....... Plasmid profiles were stable in all strains stored at -80 degrees C, and only six of 450 colonies examined from strains kept in sugar-free agar at 5 degrees C had lost plasmid molecules. Seventy of 440 colonies from stab cultures that were kept at 22 degrees C, and 71 of 440 colonies at 30 degrees C...... showed changed plasmid profiles. The total number of plasmids lost increased with time, and occasionally, more than one plasmid molecule was lost in the same strain. The virulence associated plasmid of Salm. enteritidis was remarkably stable as it was maintained in all colonies examined at all...

  16. Differences in the stability of the plasmids of Yersinia pestis cultures in vitro: impact on virulence

    TC Leal-Balbino

    2004-11-01

    Full Text Available Plasmid and chromosomal genes encode determinants of virulence for Yersinia pestis, the causative agent of plague. However, in vitro, Y. pestis genome is very plastic and several changes have been described. To evaluate the alterations in the plasmid content of the cultures in vitro and the impact of the alterations to their pathogenicity, three Y. pestis isolates were submitted to serial subculture, analysis of the plasmid content, and testing for the presence of characteristic genes in each plasmid of colonies selected after subculture. Different results were obtained with each strain. The plasmid content of one of them was shown to be stable; no apparent alteration was produced through 32 subcultures. In the other two strains, several alterations were observed. LD50 in mice of the parental strains and the derived cultures with different plasmid content were compared. No changes in the virulence plasmid content could be specifically correlated with changes in the LD50.

  17. Novel assay to measure the plasmid mobilizing potential of mixed microbial communities

    Klümper, Uli; Droumpali, Ariadni; Dechesne, Arnaud;

    2014-01-01

    Mobilizable plasmids lack necessary genes for complete conjugation and are therefore non-self-transmissible. Instead, they rely on the conjugation system of conjugal plasmids to be horizontally transferred to new recipients. While community permissiveness, the fraction of a mixed microbial...... community that can receive self-transmissible conjugal plasmids, has been studied, the intrinsic ability of a community to mobilize plasmids that lack conjugation systems is unexplored. Here, we present a novel framework and experimental method to estimate the mobilization potential of mixed communities. We...... compare the transfer frequency of a mobilizable plasmid to that of a mobilizing and conjugal plasmid measured for a model strain and for the assayed community. With Pseudomonas putida carrying the gfp-tagged mobilizable RSF1010 plasmid as donor strain, we conducted solid surface mating experiments...

  18. Molecular epidemiological study on tetracycline resistance R plasmids in enterohaemorrhagic Escherichia coli O157:H7.

    Makino, S; Asakura, H; Obayashi, T; Shirahata, T; Ikeda, T; Takeshi, K

    1999-08-01

    Restriction patterns obtained with EcoRI and Southern hybridization were used for the differentiation of tetracycline-resistant (Tet(r)) R plasmids in enterobaemorrhagic Escherichia coli (EHEC) O157:H7 isolates from a mass outbreak at a kindergarten in Obihiro-City, Hokkaido, Japan, 1996. Two kinds of Tet(r) R plasmids of 50 and 95 kb were detected. The 50-kb plasmids were identical to each other, while the 93-kb plasmids were of three types that were very similar to each other. The tet genes of both 50- and 95-kb R plasmids were 100% identical to the tet gene of pSC101 and all plasmids hybridized to a probe for tet. Because food-origin O157 strains were sensitive to tetracycline, we concluded that such Tet(r) R-plasmids might transfer to drug-sensitive O157 strains in the infected individuals. PMID:10487638

  19. Molecular epidemiological study on tetracycline resistance R plasmids in enterohaemorrhagic Escherichia coli O157:H7.

    Makino, S.; Asakura, H.; Obayashi, T.; Shirahata, T.; Ikeda, T.; Takeshi, K.

    1999-01-01

    Restriction patterns obtained with EcoRI and Southern hybridization were used for the differentiation of tetracycline-resistant (Tet(r)) R plasmids in enterobaemorrhagic Escherichia coli (EHEC) O157:H7 isolates from a mass outbreak at a kindergarten in Obihiro-City, Hokkaido, Japan, 1996. Two kinds of Tet(r) R plasmids of 50 and 95 kb were detected. The 50-kb plasmids were identical to each other, while the 93-kb plasmids were of three types that were very similar to each other. The tet genes of both 50- and 95-kb R plasmids were 100% identical to the tet gene of pSC101 and all plasmids hybridized to a probe for tet. Because food-origin O157 strains were sensitive to tetracycline, we concluded that such Tet(r) R-plasmids might transfer to drug-sensitive O157 strains in the infected individuals. PMID:10487638

  20. Applying Expectancy Theory to residency training: proposing opportunities to understand resident motivation and enhance residency training

    Shweiki, Ehyal

    2015-01-01

    Ehyal Shweiki,1 Niels D Martin,2 Alec C Beekley,1 Jay S Jenoff,1 George J Koenig,1 Kris R Kaulback,1 Gary A Lindenbaum,1 Pankaj H Patel,1 Matthew M Rosen,1 Michael S Weinstein,1 Muhammad H Zubair,2 Murray J Cohen1 1Department of Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA; 2Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA Abstract: Medical resident education in the United States has been a matter of national ...