WorldWideScience
1

Sequence-based analysis of pQBR103; a representative of a unique, transfer-proficient mega plasmid resident in the microbial community of sugar beet.  

OpenAIRE

The plasmid pQBR103 was found within Pseudomonas populations colonizing the leaf and root surfaces of sugar beet plants growing at Wytham, Oxfordshire, UK. At 425 kb it is the largest self-transmissible plasmid yet sequenced from the phytosphere. It is known to enhance the competitive fitness of its host, and parts of the plasmid are known to be actively transcribed in the plant environment. Analysis of the complete sequence of this plasmid predicts a coding sequence (CDS)-rich genome contain...

Tett, A.; Spiers, Aj; Crossman, Lc; Ager, D.; Ciric, L.; Dow, Jm; Fry, Jc; Harris, D.; Lilley, A.; Oliver, A.; Parkhill, J.; Quail, Ma; Rainey, Pb; Saunders, Nj; Seeger, K.

2007-01-01

2

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

Directory of Open Access Journals (Sweden)

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, substantial biochemical efforts will be required to dissect the complete biochemical pathway of cereulide synthesis.

Wagner Martin

2006-03-01

3

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

International Nuclear Information System (INIS)

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

4

Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens.  

OpenAIRE

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...

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

1980-01-01

5

The mega cisterna magna.  

Science.gov (United States)

Eleven cases of enlarged cisterna magna were found in a series of 3000 computerized tomography scans. We believe mega cisterna magna by itself is not related to any specific symptoms and may not require further study or treatment. PMID:624967

Adam, R; Greenberg, J O

1978-02-01

6

MegaPipe: the MegaCam image stacking pipeline  

OpenAIRE

This paper describes the MegaPipe image processing pipeline at the Canadian Astronomical Data Centre (CADC). The pipeline takes multiple images from the MegaCam mosaic camera on CFHT and combines them into a single output image. MegaPipe takes as input detrended MegaCam images and does a careful astrometric and photometric calibration on them. The calibrated images are then resampled and combined into image stacks. MegaPipe is run on PI data by request, data from large surve...

Gwyn, Stephen D. J.

2009-01-01

7

Structure of haloacetate-catabolic IncP-1beta plasmid pUO1 and genetic mobility of its residing haloacetate-catabolic transposon.  

Science.gov (United States)

The self-transmissible plasmid pUO1 from Delftia acidovorans strain B carries two haloacetate-catabolic transposons, TnHad1 and TnHad2, and the mer genes for resistance to mercury. The complete 67,066-bp sequence of pUO1 revealed that the mer genes were also carried by two Tn402/Tn5053-like transposons, Tn4671 and Tn4672, and that the pUO1 backbone regions shared 99% identity to those of the archetype IncP-1beta plasmid R751. Comparison of pUO1 with three other IncP-1beta plasmids illustrated the importance of transposon insertion in the diversity and evolution of this group of plasmids. Mutational analysis of the four outermost residues in the inverted repeats (IRs) of TnHad2, a Tn21-related transposon, revealed a crucial role of the second residue of its IRs in transposition. PMID:14594853

Sota, Masahiro; Kawasaki, Haruhiko; Tsuda, Masataka

2003-11-01

8

Mega cisterna magna  

Energy Technology Data Exchange (ETDEWEB)

Computerized tomography (CT) has made it possible to discover various uncommon intracranial structures and to elucidate the morbidity of these pathophysiological conditions. The mega cisterna magna is an example of such a structure being widely known, but the incidence and morbidity being uncertain. Since the mega cisterna magna has shown no special symptoms and signs and does not require any surgical treatment, it was not necessary to diagnose it property before the establishment of routine examination by CT. From April 1979 to June 1980; a total of 2089 patients were examined by CT; of these, 9 cases (0.43%) of mega cisterna magna were identified. The symptoms and signs of those 9 patients were headache, vertigo, nausea, right hemiparesis, convulsive seizure, hyperventilation syndrome, and tremor. One patient was examined for head injury. A plain craniogram revealed a thinness of the occipital bone in 2 cases. The sizes of the mega cisterna magna appearing on CT were from 1.0 x 1.5 cm to 3.5 x 4.0 cm at the level of +40 -60 mm from the plane of the 0/sup 0/ OM line. The craniotomy was performed on one patient who was suspected of having arachnoiditis in the posterior fossa.

Kumagai, Y.; Yamakawa, K.; Tsujita, Y.; Sugiyama, H.; Nawata, H. (Ebara Metropolitan Hospital, Tokyo (Japan))

1981-06-01

9

Muonium and MEGA  

International Nuclear Information System (INIS)

Two types of experiments on muonium are described. The first measures the hyperfine structure interval in muonium, and the second measures the Lamb shift. Another type of experiment is described which searches for the transition (?+e-)?(?-e+). The MEGA experiment is then discussed which searches for the reaction ? ? e + ?. 13 figs., 3 refs

10

Mega cisterna magna  

International Nuclear Information System (INIS)

Computerized tomography (CT) has made it possible to discover various uncommon intracranial structures and to elucidate the morbidity of these pathophysiological conditions. The mega cisterna magna is an example of such a structure being widely known, but the incidence and morbidity being uncertain. Since the mega cisterna magna has shown no special symptoms and signs and does not require any surgical treatment, it was not necessary to diagnose it property before the establishment of routine examination by CT. From April 1979 to June 1980; a total of 2089 patients were examined by CT; of these, 9 cases (0.43%) of mega cisterna magna were identified. The symptoms and signs of those 9 patients were headache, vertigo, nausea, right hemiparesis, convulsive seizure, hyperventilation syndrome, and tremor. One patient was examined for head injury. A plain craniogram revealed a thinness of the occipital bone in 2 cases. The sizes of the mega cisterna magna appearing on CT were from 1.0 x 1.5 cm to 3.5 x 4.0 cm at the level of +40 -60 mm from the plane of the 00 OM line. The craniotomy was performed on one patient who was suspected of having arachnoiditis in the posterior fossa. (J.P.N.)

11

BACTERIAL PLASMIDS  

Directory of Open Access Journals (Sweden)

Full Text Available Plasmids, extrachromosomal DNA, were identified in bacteria pertaining to family of Enterobacteriacae for the very first time. After that, they were discovered in almost every single observed strain. The structure of plasmids is made of circular double chain DNA molecules which are replicated autonomously in a host cell. Their length may vary from few up to several hundred kilobase (kb. Among the bacteria, plasmids are mostly transferred horizontally by conjugation process. Plasmid replication process can be divided into three stages: initiation, elongation, and termination. The process involves DNA helicase I, DNA gyrase, DNA polymerase III, endonuclease, and ligase.Plasmids contain genes essential for plasmid function and their preservation in a host cell (the beginning and the control of replication. Some of them possess genes whichcontrol plasmid stability. There is a common opinion that plasmids are unnecessary fora growth of bacterial population and their vital functions; thus, in many cases they can be taken up or kicked out with no lethal effects to a plasmid host cell. However,there are numerous biological functions of bacteria related to plasmids. Plasmids identification and classification are based upon their genetic features which are presented permanently in all of them, and these are: abilities to preserve themselves in a host cell and to control a replication process. In this way, plasmids classification among incompatibility groups is performed. The method of replicon typing, which is based on genotype and not on phenotype characteristics, has the same results as in compatibility grouping.

Marina Dinic

2007-12-01

12

MegaPipe: the MegaCam image stacking pipeline  

CERN Document Server

This paper describes the MegaPipe image processing pipeline at the Canadian Astronomical Data Centre (CADC). The pipeline takes multiple images from the MegaCam mosaic camera on CFHT and combines them into a single output image. MegaPipe takes as input detrended MegaCam images and does a careful astrometric and photometric calibration on them. The calibrated images are then resampled and combined into image stacks. MegaPipe is run on PI data by request, data from large surveys (the CFHT Legacy Survey and the Next Generation Virgo Survey) and all non-proprietary MegaCam data in the CFHT archive. The stacked images and catalogs derived from these images are available through the CADC website. Currently, 1500 square degrees have been processed.

Gwyn, Stephen D J

2009-01-01

13

The Mega Mesospheric Parachute  

Science.gov (United States)

The current understanding and modeling of the upper reaches of the atmosphere is incomplete. Upper atmospheric interactions with the lower atmosphere, effects of ionizing radiation, high altitude cloud phenomena, and the dynamical interaction with the magnetosphere require greater definition. The scientific objective of obtaining a greater understanding of the upper atmosphere can be achieved by designing, implementing, testing, and utilizing a facility that provides long period in-situ measurements of the mesosphere. Current direct sub-sonic measurements of the upper atmosphere are hampered by the approximately one minute sub-sonic observation window of a ballistic sounding rocket regardless of the launch angle. In-situ measurements at greater than transonic speeds impart energy into the molecular atmospheric system and distort the true atmospheric chemistry. A long duration, sub-sonic capability will significantly enhance our ability to observe and measure: (1) mesospheric lightning phenomena (sprites and blue jets) (2) composition, structure and stratification of noctilucent clouds (3) physics of seasonal radar echoes, gravity wave phenomena (4) chemistry of mesospheric gaseous ratio mixing (5) mesospheric interaction of ionizing radiation (6) dynamic electric and magnetic fields This new facility will also provide local field measurements which complement those that can be obtained through external measurements from satellite and ground-based platforms. The 400 foot (approximately 130 meter) diameter lightweight mega-mesospheric parachute system, deployed with a sounding rocket, is proposed herein as a method to increase sub-sonic mesospheric measurement time periods by more than an order of magnitude. The report outlines a multi-year evolving science instrumentation suite in parallel with the development of the mega meso-chute facility. The developmental issues surrounding the meso-chute are chiefly materials selection (thermal and structural) and deployment mechanism physics. Three mission cases were conceived and developed to include cost and schedules estimates. Each scenario has increasing scientific utility with paralleling launch weight, parachute hang-time, deployment altitude, and parachute size: (1) Case #1: $8.4M@24 months, 6kg payload, 20 min., 50km alt., 80 m. dia. (2) Case #2: $10.4M@24 months, 6kg payload, 20 min., 60km alt, 130m. dia. (3) Case #3: $13.6M@36 months, 30kg payload, 30 min., 90km alt., 200m. dia. The initial breakout cost for the parachute system is approximately $2M@24 months. This report identifies that although the challenges of the mega-meso-chute may be difficult, they can be surmounted and valuable results can be achieved.

Kloesel, Kurt J.; Oberto, Robert; Kinsey, Robert

2005-01-01

14

Mega cisterna magna  

Energy Technology Data Exchange (ETDEWEB)

Reported here are 5 cases of large cisterna magna (mega cisterna magna MCM), MCM has been known commonly to be of radiological interest; a consideration of the literature and of our clinical results has shown that: (1) CT reveals an omega-shaped low-density area in the posterior part of the posterior fossa, without any effect of contrast enhancement. (2) Usually MCM has no mass effect except when it shows the valve phenomenon. (3) MCM by itself has no relation with any specific symptoms and may not require further examination or treatment. CT is a non-invasive method, available for the screening examination of out-patients; the opportunity to locate MCM with exactitude increases with the use of CT.

Suzuki, M.; Ebina, K. (Hirosaki Univ., Aomori (Japan). School of Medicine); Harata, N.

1980-10-01

15

Photon detector for MEGA  

International Nuclear Information System (INIS)

The MEGA photon detector is designed to observe the 52.83-MeV photon produced in a ? ? e? decay with an energy resolution of 1.25 MeV, a position resolution of 2 x 5 mm2, a directional resolution of 10 degree, a time resolution of 500 ps, and an efficiency of about 5.4%. It will consist of three independent concentric cylindrical pair spectrometers mounted within a 1.5 T magnetic field produced by a superconducting solenoid magnet. Each pair spectrometer includes two thin Pb foils to convert photons into e+e- pairs. The two smaller pair spectrometers will have three drift chamber layers to track the e+e- pairs and thereby determine both their locations and their vector momenta. The third pair spectrometer will have four layers of drift chamber, together with a larger turning region, to provide better tracking information for high energy photons. The inner drift chamber layer in each of the spectrometers includes a delay line cathode to determine the z coordinates needed for track reconstruction. An MWPC located between the two Pb layers identifies the conversion layer so that energy loss corrections may be applied, while plastic scintillators provide timing information. During the past year, efforts have focused primarily on software development, completion of the delay line tests, and development of electronics for the scintillators and delay line read-out. Optical windows were glued onto the light guides required for the third pair spectrometer. In addition, major contributions were made to the development of a proposal to measure the Michel parameter, ?, using the MEGA positron detectors

16

Photon detector for MEGA  

International Nuclear Information System (INIS)

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

17

Plasmids in diatom species.  

OpenAIRE

We have discovered plasmids in 5 of 18 diatom species surveyed. In several species, more than one type of plasmid is present. Several of the plasmids show similarity by hybridization previously characterized plasmids in Cylindrotheca fusiformis (J. D. Jacobs et al., unpublished data). Additionally, there is similarity between the plasmids found in C. fusiformis and chloroplast DNA in three diatom species. These results add to the evidence that the plasmids have features of mobile genetic elem...

Hildebrand, M.; Corey, D. K.; Ludwig, J. R.; Kukel, A.; Feng, T. Y.; Volcani, B. E.

1991-01-01

18

The MEGA data acquisition system  

Energy Technology Data Exchange (ETDEWEB)

The MEGA experiment will acquire 3 MB/sec of data into a 9-crate Fastbus system controlled by a single Fastbus master. A second-level trigger will be implemented in a Fermilab Advanced Computer Program (ACP) farm of 32 Motorola 68020 microprocessors. Output from the ACP farm at a rate of 24 KB/sec will be sent to a MicroVAX II for taping.

Oothoudt, M.A.; Amann, J.F.; Bolton, R.D.; Cooper, M.D.; Foreman, W.M.; Hogan, G.E.; Kozlowski, T.; Naivar, F.J.; Smith, W.

1987-08-01

19

The MEGA data acquisition system  

Energy Technology Data Exchange (ETDEWEB)

The MEGA experiment will acquire 3 MB/sec of data into a 9-crate Fastbus system controlled by a single Fastbus master. A second-level trigger will be implemented in a Fermilab Advanced Computer Program (ACP) farm of 32 Motorola 68020 microprocessors. Output from the ACP farm at a rate of 24 KB/sec will be sent to a MicroVAX II for taping. 16 refs.

Oothoudt, M.A.; Amann, J.F.; Bolton, R.D.; Hughes, E.B.; Jui, C.C.H.; Cooper, P.S.; Hahn, K.; Lauer, R.B.; Markey, J.K.

1987-01-01

20

Faithful segregation of the multicopy yeast plasmid through cohesin-mediated recognition of sisters  

OpenAIRE

The 2-?m yeast plasmid, a benign high-copy nuclear parasite, propagates itself with nearly the same fidelity as the chromosomes of its host. Equal plasmid segregation is absolutely dependent on the cohesin complex assembled at the plasmid partitioning locus STB. However, the mechanism of cohesin action in the context of multiple plasmid copies, resident within two separate clusters after DNA replication, is unknown. By using “single-copy” derivatives of the 2-?m plasmid, we demonstrate ...

Ghosh, Santanu K.; Hajra, Sujata; Jayaram, Makkuni

2007-01-01

21

FACT, Mega-ROSA, SOLAROSA  

Science.gov (United States)

The Flexible Array Concentrator Technology (FACT) is a lightweight, high-performance reflective concentrator blanket assembly that can be used on flexible solar array blankets. The FACT concentrator replaces every other row of solar cells on a solar array blanket, significantly reducing the cost of the array. The modular design is highly scalable for the array system designer, and exhibits compact stowage, good off-pointing acceptance, and mass/cost savings. The assembly s relatively low concentration ratio, accompanied by a large radiative area, provides for a low cell operating temperature, and eliminates many of the thermal problems inherent in high-concentration-ratio designs. Unlike other reflector technologies, the FACT concentrator modules function on both z-fold and rolled flexible solar array blankets, as well as rigid array systems. Mega-ROSA (Mega Roll-Out Solar Array) is a new, highly modularized and extremely scalable version of ROSA that provides immense power level range capability from 100 kW to several MW in size. Mega-ROSA will enable extremely high-power spacecraft and SEP-powered missions, including space-tug and largescale planetary science and lunar/asteroid exploration missions. Mega-ROSA's inherent broad power scalability is achieved while retaining ROSA s solar array performance metrics and missionenabling features for lightweight, compact stowage volume and affordability. This innovation will enable future ultra-high-power missions through lowcost (25 to 50% cost savings, depending on PV and blanket technology), lightweight, high specific power (greater than 200 to 400 Watts per kilogram BOL (beginning-of-life) at the wing level depending on PV and blanket technology), compact stowage volume (greater than 50 kilowatts per cubic meter for very large arrays), high reliability, platform simplicity (low failure modes), high deployed strength/stiffness when scaled to huge sizes, and high-voltage operation capability. Mega-ROSA is adaptable to all photovoltaic and concentrator flexible blanket technologies, and can readily accommodate standard multijunction and emerging ultra-lightweight IMM (inverted metamorphic) photovoltaic flexible blanket assemblies, as well as ENTECHs Stretched Lens Array (SLA) and DSSs (Deployable Space Systems) FACT, which allows for cost reduction at the array level.

Spence, Brian; White, Steve; Schmid, Kevin; Douglas Mark

2012-01-01

22

MegaPipe: the MegaCam image stacking pipeline at the Canadian Astronomical Data Centre  

OpenAIRE

This paper describes the MegaPipe image processing pipeline at the Canadian Astronomical Data Centre. The pipeline combines multiple images from the MegaCam mosaic camera on CFHT and combines them into a single output image. MegaPipe takes as input detrended MegaCam images and does a careful astrometric and photometric calibration on them. The calibrated images are then resampled and combined into image stacks. The astrometric calibration of the output images is accurate to ...

Gwyn, Stephen D. J.

2007-01-01

23

Plasmids of Azotobacter vinelandii.  

OpenAIRE

Four laboratory strains and two isolates of Azotobacter vinelandii were found to contain plasmids. Twenty-five laboratory strains which could fix nitrogen did not have free, covalently closed circular plasmid DNA. The plasmids varied in size from 9 to 52 megadaltons, and each strain yielded only one plasmid. No discernible differences in ability to fix nitrogen were found between plasmid-bearing and cured cultures.

Maia, M.; Sanchez, J. M.; Vela, G. R.

1988-01-01

24

Characterization of non-virulence plasmids with homology to the virulence plasmid of Salmonella dublin.  

Science.gov (United States)

Six wild-type (wt) strains of Salmonella typhimurium, one wt strain of S. heidelberg and 12 wt strains of Escherichia coli were isolated based on both hybridization to a 6-kb HindIII fragment of the non-virulence coding part of the S. dublin serovar-specific virulence plasmid and the absence of hybridization to the virulence genes (spv genes) of the same plasmid. Such hybridization was shown to be caused by resident plasmids in all strains and to involve the same region of 30 to 37 kb of consecutive HindIII fragments on the S. dublin virulence plasmid, suggesting a common origin of this plasmid DNA. Nine of the plasmids were selected for detailed characterization and were shown not to be of the same plasmid species. They varied in size between 44 and 88 kb, they showed incompatibility with the plasmid K-MP10, or belonged to incompatibility group X, and with the exception of five plasmids from E. coli, they showed different HindIII restriction profile patterns. PMID:8584797

Aabo, S; Olsen, J E; Threlfall, E J; Brown, D J

1995-01-01

25

Manic episode associated with mega cisterna magna.  

Science.gov (United States)

Mega cisterna magna is a part of "Dandy-Walker Complex" and it is characterized by the enlargement of the cisterna magna, morphologically intact vermis and cerebellar hemispheres. We report a case of manic attack in a 23-year-old man with mega cisterna magna. The patient was treated with quetiapine 1,000 mg/day and sodium valproate 1,500 mg/day and the symptoms were ameliorated within 2.5 months. In this case, mega cisterna magna and manic symptoms may be found together coincidentally or any cerebellar dysfunction due to mega cisterna magna may cause or contribute to the appearance of affective symptoms. To our knowledge, this is the first case reporting manic attack with psychotic symptoms associated with mega cisterna magna. This report suggests that any lesion in the cerebellum might contribute to the occurrences of some affective and psychotic symptoms seen in bipolar disorder. PMID:21253417

Turan, Tayfun; Be?irli, Asl?; Asdemir, Akif; Ozsoy, Saliha; E?el, Ertu?rul

2010-12-01

26

MEGA - A search for ? ? e?  

International Nuclear Information System (INIS)

The MEGA experiment is a search for the decay ? ? e?. Even though there is no fundamental reason to expect lepton number to be a conserved quantity, processes such as ? ? e? have not been observed. (The present upper limit for the branching ratio for ? ? e? is 4.9 x 10-11.) The minimal standard model of electroweak interactions, which is enormously successful, builds in lepton number conservation. However, the decay ? ? e? is expected in many extensions to the standard model, in particular in supersymmetry models. The experimental signature for ? ? e? from decays at rest is the observation of a positron and photon, each of 52.8 MeV , that are back-to-back, in time coincidence, and originate from a common spatial point. The MEGA detector consists of two spectrometers designed to measure the kinematic characteristics of positrons and photons to search for events with this signature. The primary difficulty in the analysis of these data has been the development of reconstruction algorithms that balance efficiency and resolution. Also, many calibrations and corrections are needed to get optimum resolutions. Most surviving candidate events are accidentals. Results of analysis are given

27

Manic Episode Associated with Mega Cisterna Magna  

OpenAIRE

Mega cisterna magna is a part of "Dandy-Walker Complex" and it is characterized by the enlargement of the cisterna magna, morphologically intact vermis and cerebellar hemispheres. We report a case of manic attack in a 23-year-old man with mega cisterna magna. The patient was treated with quetiapine 1,000 mg/day and sodium valproate 1,500 mg/day and the symptoms were ameliorated within 2.5 months. In this case, mega cisterna magna and manic symptoms may be found together coincidentally or any ...

Turan, Tayfun; Bes?irli, Asl?; Asdemir, Akif; O?zsoy, Saliha; Es?el, Ertug?rul

2010-01-01

28

Staphylococcal plasmids that replicate and express erythromycin resistance in both Streptococcus pneumoniae and Escherichia coli.  

OpenAIRE

Plasmid pSA5700 from Staphylococcus aureus coding for erythromycin (EmR) and chloramphenicol (CmR) resistance was transformed into Streptococcus pneumoniae. High-copy-number and EmR constitutive mutants of this plasmid were isolated. Transformation frequencies in S. pneumoniae as high as 70% were obtained with a constitutive plasmid as donor DNA, into a recipient cell containing a resident, inducible, high-copy-number plasmid. With the aid of these high frequencies, the site of constitutive m...

Barany, F.; Boeke, J. D.; Tomasz, A.

1982-01-01

29

Plasmid Mediated Chromate Resistance in Bacteria Isolated from Industrial Waste  

Directory of Open Access Journals (Sweden)

Full Text Available In order to study the genetic basis and mechanism of chromate resistance in chromate resistant bacteria, conjugal transfer as well as curing of plasmids in these bacteria and its effect on chromium uptake are being investigated. From the effluent of Shafiq Tannery, Kasur, Pakistan, four bacterial strains STCr-1, STCr-2, STCr-3 and STCr-4 which could endure 40 mg mL-1 of potassium chromate in nutrient agar medium were isolated. All of them were gram negative, aerobic and motile rods. One strain STCr-1 was identified as Ochrobactrum species by 16S rRNA gene sequence homology. Each strain harboured a single conjugative plasmid, which conferred resistance to chromate. Maximum plasmid transfer was recorded after 24 h of mating except for plasmid residing in STCr-3 (pSH1322, which transferred maximally after 16 h of mating. The plasmids harboring STCr-1 (pSH1320, STCr-3 (pSH1322 and STCr-4 (pSH1323 manifested highest transfer frequency at donor:recipient ratio 1, while plasmid resident of STCr-2 (pSH1321 preferred donor:recipient ratio 5. Transfer frequency of plasmids pSH1320 and pSH1322 was maximal at 28°C and that of pSH1321 and pSH1323 at 37°C. Optimum pH for plasmid transfer was 8 for these plasmids except pSH1320, which opted for pH 6 or 7. Curing of chromate resistant plasmids from these strains was achieved with SDS at high temperature and curing of plasmid was associated with the loss of chromate resistance phenotype. A comparison of Cr uptake by the parental strains and their cured derivatives revealed that plasmids in these strains express high level resistance to chromate by exerting stringent control on the accumulation/uptake of Cr.

Sikander Sultan

2005-01-01

30

Structuring a mega-project  

Energy Technology Data Exchange (ETDEWEB)

This paper presented an overview of mega-project management. Issues concerning scope, cost and schedule were discussed, with reference to the idea that a choice must be made from the outset as to which of the 3 is a main priority. The importance of preparation and the development of a fully resourced plan was emphasized. The use of the parametric 4-D model was discussed. Lessons that the construction industry may learn from manufacturers were presented along with issues of contract development and the role and importance of the project manager. Issues concerning performance measurement were reviewed, including lagging indicators. Project division factors were also discussed, with reference to data lags, naturally concurrent processes and over the fence units. A case study of Walmart was presented. Project design packages and long lead time items were discussed, as were issues concerning human resources. Functional units were examined in relation to zones of influence and unit integration. Various combinations of zones of influence were presented. Issues concerning span of control and varying relationships within a project were discussed. It was emphasized that great deeds can be accomplished by attracting the best people. tabs., figs.

Kutryk, T. [Husky Oil Operations Ltd., Calgary, AB (Canada)

2004-07-01

31

Colicin V virulence plasmids.  

OpenAIRE

ColV plasmids are a heterogeneous group of IncFI plasmids which encode virulence-related properties such as the aerobactin iron uptake system, increased serum survival, and resistance to phagocytosis. These plasmids have been found in invasive strains of Escherichia coli which infect vertebrate hosts including humans and livestock. Colicin V was the first colicin to be identified, in 1925, but not until the field experienced a renewed interest has the mechanism of colicin V activity been expl...

Waters, V. L.; Crosa, J. H.

1991-01-01

32

Innovative European Solutions in Managing the Mega-Crisis  

Science.gov (United States)

The following sections are included: * INTRODUCTION * PREPAREDNESS LEVEL IN EU MEMBER STATES * OPERATIONAL CHALLENGES DUE TO MEGA-CRISIS * REQUIREMENTS FOR MANAGING A MEGA-CRISIS * INNOVATIVE ENDUSER FRIENDLY SOLUTIONS * CONCLUSIONS

Steinhäusler, Friedrich

2014-07-01

33

The MEGA Advanced Compton Telescope Project  

OpenAIRE

The goal of the Medium Energy Gamma-ray Astronomy (MEGA) telescope is to improve sensitivity at medium gamma-ray energies (0.4-50 MeV) by at least an order of magnitude over that of COMPTEL. This will be achieved with a new compact design that allows for a very wide field of view, permitting a sensitive all-sky survey and the monitoring of transient and variable sources. The key science objectives for MEGA include the investigation of cosmic high-energy particle accelerators...

Bloser, P. F.; Andritschke, R.; Kanbach, G.; Schoenfelder, V.; Schopper, F.; Zoglauer, A.; Collaboration, For The Mega

2001-01-01

34

The Mega-journals are coming!  

OpenAIRE

Mega-journals er et nytt begrep og en ny realitet innen vitenskapelige tidsskrifter – selv om de i virkeligheten ikke lenger er tidsskrifter, men artikkeldatabaser. Dette startet med PLoS ONE, som i dag er verdens største tidsskrift målt i antall artikler per år – og det vokser stadig. Fortsetter veksten vil PLoS ONE om få år være verdens eneste STM-tidsskrift. Flere mega-journals er nå startet opp – flere begynte/begynner sin virksomhet i år. Disse tidsskriftene vil trolig medf...

Frantsva?g, Jan Erik

2011-01-01

35

Construction and Use of Flow Cytometry Optimized Plasmid-Sensor Strains : Genomes in Flux  

DEFF Research Database (Denmark)

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.

Bahl, Martin Iain; Oregaard, Gunnar

2009-01-01

36

Faithful segregation of the multicopy yeast plasmid through cohesin-mediated recognition of sisters.  

Science.gov (United States)

The 2-microm yeast plasmid, a benign high-copy nuclear parasite, propagates itself with nearly the same fidelity as the chromosomes of its host. Equal plasmid segregation is absolutely dependent on the cohesin complex assembled at the plasmid partitioning locus STB. However, the mechanism of cohesin action in the context of multiple plasmid copies, resident within two separate clusters after DNA replication, is unknown. By using "single-copy" derivatives of the 2-microm plasmid, we demonstrate that recruitment of cohesin at STB during S phase indeed translates into cohesion between plasmid molecules. Through binary fluorescence tagging, we reveal that segregation of replicated plasmids occurs in a sister-to-sister fashion. Thus, cohesin serves the same fundamental purpose in plasmid and chromosome segregation. PMID:17670945

Ghosh, Santanu K; Hajra, Sujata; Jayaram, Makkuni

2007-08-01

37

Indian manpower for mega nuclear project  

CERN Document Server

"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).

2003-01-01

38

The MEGA Advanced Compton Telescope Project  

CERN Document Server

The goal of the Medium Energy Gamma-ray Astronomy (MEGA) telescope is to improve sensitivity at medium gamma-ray energies (0.4-50 MeV) by at least an order of magnitude over that of COMPTEL. This will be achieved with a new compact design that allows for a very wide field of view, permitting a sensitive all-sky survey and the monitoring of transient and variable sources. The key science objectives for MEGA include the investigation of cosmic high-energy particle accelerators, studies of nucleosynthesis sites using gamma-ray lines, and determination of the large-scale structure of galactic and cosmic diffuse background emission. MEGA records and images gamma-ray events by completely tracking both Compton and pair creation interactions in a tracker of double-sided silicon strip detectors and a calorimeter of CsI crystals able to resolve in three dimensions. We present initial laboratory calibration results from a small prototype MEGA telescope.

Bloser, P F; Kanbach, G; Schönfelder, V; Schopper, Herwig Franz; Zoglauer, A

2002-01-01

39

Plasmids in the environment.  

Science.gov (United States)

Bacterial plasmids existed in bacteria before the antibiotic era but their presence was brought into prominence by the use of antibiotics which selected for antibiotic resistant strains. Subsequently, the range of genes carried on plasmids was shown to extend far beyond those coding for antibiotic resistance. Any consideration of plasmids in the environment, therefore, must include all plasmids whether or not they are genetically linked with antibiotic resistance. Antibiotic resistant bacteria may be found in the environment either by contamination with excreta from man and animals in which the strains were selected, or by their selection within the environment by antibiotics synthesized in situ or reaching the environment in an undegraded form in sewage from man and animals, or from industry. Other agents, also contaminating the environment, exert a selective pressure such as heavy metals in industrial effluents which select for metal resistance. This paper reviews the incidences and role of plasmids in various habitats including natural waters, soil, pastures, farm wastes, and human sewage from both hospitalised and other populations. Aspects of plasmid ecology, their biological role, and the transmissibility of genetic material between bacteria within the environment are considered. Two recent studies in Bristol, UK, are reported. The first was a genetic study on Escherichia coli isolates from calf slurry. Various DNA probes were used to determine the extent of gene exchange between the various serotypes within the natural environment. The second was a preliminary study to determine the stability of a recombinant plasmid, in a wild strain of Escherichia coli of pig origin, after its release into a semi-contained farm situation. It is now recognized that plasmids are widely distributed in bacterial populations in terrestrial and aquatic environments. Many have been detected by their carriage of genes coding for antibiotic or heavy metal resistance. Others, mainly cryptic in nature, have been demonstrated by plasmid profile studies on isolates from various habitats. Plasmids were shown to be present in a relatively few bacteria deposited in culture collections prior to the antibiotic era. Subsequently, the increased prevalence of R plasmids in bacteria in most ecosystems were due mainly to the selective pressure imposed by the use of antibiotics. This pressure may have been exerted either in the environment in which the strains were found or elsewhere, the environment subsequently being contaminated by antibiotic resistant bacteria.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3074480

Linton, A H

1988-01-01

40

Natural plasmids of filamentous fungi.  

OpenAIRE

Among eukaryotes, plasmids have been found in fungi and plants but not in animals. Most plasmids are mitochondrial. In filamentous fungi, plasmids are commonly encountered in isolates from natural populations. Individual populations may show a predominance of one type, but some plasmids have a global distribution, often crossing species boundaries. Surveys have shown that strains can contain more than one type of plasmid and that different types appear to be distributed independently. In cros...

Griffiths, A. J.

1995-01-01

41

Architecture of the MEGA detector trigger  

International Nuclear Information System (INIS)

The trigger for the MEGA detector system is based on signals from single, high-energy photons interacting in one of the three MEGA pair spectrometers. The trigger is divided into a fast and a slow stage. The first stage produces a fast output if a specific pattern of detector hits is observed in the scintillators and high-speed wire chambers of a pair spectrometer. The second, slow-stage interrogates drift chamber hit patterns and provides a veto when the pattern fails a minimal requirement for reconstruction of the hits into a pair of circular orbits. The trigger interacts with the photon detector electronics by gating limited sections of the detector during the read-out of an event. This paper describes the two stage trigger system, the photon detector electronics, and the implementation of the trigger outputs to strobe the data acquisition system. The performance of the trigger is compared to Monte Carlo simulations of the photon detector response. (orig.)

42

Proximal femoral reconstruction with custom mega prosthesis  

OpenAIRE

Seventy-seven patients with proximal femoral tumours underwent limb salvage surgery with custom mega prostheses between July 1989 and January 2002. We describe 44 cases with a mean follow-up of 57.8 months. Forty-one patients presented with malignant neoplasms of which 11 were malignant giant cell tumours, eight were chondrosarcoma and five were metastases. Wide margins were achieved for all malignant tumours, and marginal resection was done for all benign and metastatic lesions. Six patients...

Natarajan, M.; Bose, J. C.; Rajkumar, G.

2003-01-01

43

Psychiatric manifestations associated with mega cisterna magna.  

Science.gov (United States)

The Dandy-Walker variant is a milder form of the Dandy-Walker complex and is characterized by normal-sized posterior fossa, mild vermian hypoplasia, and a cystic lesion that communicates with the fourth ventricle. This syndrome has been described in association with schizophrenia, obsessive-compulsive disorder, manic episode, psychosis (delusional type), and recurrent catatonia. The authors present two cases of mega cisterna magna associated with mania and catatonic schizophrenia. PMID:24763763

Pandurangi, Swapna; Pandurangi, Aditya; Matkar, Abhay; Shetty, Nithin; Patil, Preetam

2014-04-01

44

MEGA: A search for the decay ??e?  

International Nuclear Information System (INIS)

The MEGA experiment is designed to search for the rare decay ??e? with a branching ratio sensitivity of ?5x10-13. Production data have been taken during 1992 and 1993, and the detector is working as expected. Following a complete analysis, the present data set should represent an improvement of 12--15 in sensitivity over the previous limit of ??e?. copyright 1995 American Institute of Physics

45

Plasmids encoding therapeutic agents  

Energy Technology Data Exchange (ETDEWEB)

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.

Keener, William K. (Idaho Falls, ID)

2007-08-07

46

Mega cisterna magna: diagnosis using metrizamide computed tomographic cisternography.  

Science.gov (United States)

The mega cisterna magna is one cause of a midline, extra-axial, posterior fossa cyst. The computed tomographic features and differential diagnosis of midline posterior fossa cystic structures are reviewed, and the clinical features of the mega cisterna magna are discussed. We describe a method of metrizamide cisternography and report a case of mega cisterna magna that was diagnosed by this technique. PMID:7121784

Hough, D R; Mengel, M B; Malik, A H

1982-08-01

47

MEGA6: Molecular Evolutionary Genetics Analysis Version 6.0  

OpenAIRE

We announce the release of an advanced version of the Molecular Evolutionary Genetics Analysis (MEGA) software, which currently contains facilities for building sequence alignments, inferring phylogenetic histories, and conducting molecular evolutionary analysis. In version 6.0, MEGA now enables the inference of timetrees, as it implements the RelTime method for estimating divergence times for all branching points in a phylogeny. A new Timetree Wizard in MEGA6 facilitates this timetree infere...

Tamura, Koichiro; Stecher, Glen; Peterson, Daniel; Filipski, Alan; Kumar, Sudhir

2013-01-01

48

Phytoplasma plasmid DNA extraction.  

Science.gov (United States)

Phytoplasma plasmids have generally been detected from DNA extracted from plants and insects using methods designed for the purification of total phytoplasma DNA. Methods include extraction from tissues that are high in phytoplasma titre, such as the phloem of plants, with the use of CsCl-bisbenzimide gradients that exploit the low G+C content of phytoplasma DNA. Many of the methods employed for phytoplasma purification have been described elsewhere in this book. Here we describe in detail two methods that are specifically aimed at isolating plasmid DNA. PMID:22987431

Andersen, Mark T; Liefting, Lia W

2013-01-01

49

Plasmid Mediated Degradation of Phenol by Two Bacterial Strains Pseudomonas sp. and Staphylococcus sp.  

Directory of Open Access Journals (Sweden)

Full Text Available Two microorganisms, which utilize phenol as a sole source of carbon and energy, were isolated from an enrichment culture. The microorganisms were identified as Pseudomonas sp. and Staphylococcus sp. The bacterial strains were found to harbor three endogenous plasmids. Two of the plasmids were lost when the microorganisms were treated with ethidium bromide. Loss of the plasmids in the organisms were correlated with the loss of the ability to metabolize phenol. Phenotypic testing of the wild type and cured strains revealed that the gene(s responsible for phenol degradation may reside upon the plasmids.

Asif H. Chowdhuryi

2000-01-01

50

O'Mega: An Optimizing Matrix Element Generator  

OpenAIRE

I sketch the architecture of O'Mega, a new optimizing compiler for tree amplitudes in quantum field theory. O'Mega generates the most efficient code currently available for scattering amplitudes for many polarized particles in the standard model. A complete infrastructure for physics beyond the standard model is provided.

Infn, Mauro Morettiuniv Di Ferrara Ferrara; Thorsten OhlTU Darmstadt; Juergen ReuterTU Darmstadt

2014-01-01

51

Population Growth and Policies in Mega-Cities. Sao Paulo.  

Science.gov (United States)

This document is one in a series of studies that focus on the population policies and plans of a number of mega-cities in developing countries. The object of the series is to examine the formulation, implementation, and evaluation of the population policies of mega-cities from a broad perspective, emphasizing the reciprocal links between…

United Nations New York, NY. Dept. of Economic and Social Information and Policy Analysis.

52

Development of MicroMegas for a Digital Hadronic Calorimeter  

OpenAIRE

Recent developments on the MicroMegas prototypes built by use of the bulk technology with analog and digital readout electronics are presented. The main test beam results of a stack of several MicroMegas prototypes fully comply with the needs of a hadronic calorimeter for future particle physics experiments. A technical solution for a large scale prototype is also introduced.

Adloff, Catherine; Blaha, Jan; Espargiliere, Ambroise; Karyotakis, Yannis

2009-01-01

53

Novel Macrolide Resistance Module Carried by the IncP-1? Resistance Plasmid pRSB111, Isolated from a Wastewater Treatment Plant?  

OpenAIRE

The macrolide resistance plasmid pRSB111 was isolated from bacteria residing in the final effluents of a wastewater treatment plant. The 47-kb plasmid confers resistance to azithromycin, clarithromycin, erythromycin, roxithromycin, and tylosin when it is carried by Pseudomonas sp. strain B13 and is very similar to prototype IncP-1? plasmid pB3, which was previously isolated from an activated-sludge bacterial community of a wastewater treatment plant. The two plasmids differ in their accessor...

Szczepanowski, Rafael; Krahn, Irene; Bohn, Nadine; Pu?hler, Alfred; Schlu?ter, Andreas

2006-01-01

54

MEGA6: Molecular Evolutionary Genetics Analysis version 6.0.  

Science.gov (United States)

We announce the release of an advanced version of the Molecular Evolutionary Genetics Analysis (MEGA) software, which currently contains facilities for building sequence alignments, inferring phylogenetic histories, and conducting molecular evolutionary analysis. In version 6.0, MEGA now enables the inference of timetrees, as it implements the RelTime method for estimating divergence times for all branching points in a phylogeny. A new Timetree Wizard in MEGA6 facilitates this timetree inference by providing a graphical user interface (GUI) to specify the phylogeny and calibration constraints step-by-step. This version also contains enhanced algorithms to search for the optimal trees under evolutionary criteria and implements a more advanced memory management that can double the size of sequence data sets to which MEGA can be applied. Both GUI and command-line versions of MEGA6 can be downloaded from www.megasoftware.net free of charge. PMID:24132122

Tamura, Koichiro; Stecher, Glen; Peterson, Daniel; Filipski, Alan; Kumar, Sudhir

2013-12-01

55

First Microlensing Events From The MEGA Survey  

CERN Document Server

We present the first M31 microlensing events from the Microlensing Exploration of the Galaxy and Andromeda (MEGA) survey. MEGA uses several telescopes to detect microlensing towards the nearby Andromeda galaxy, M31, in order to establish whether massive compact objects are a significant contribution to the mass budget of the dark halo of M31. The results presented here are based on observations with the Isaac Newton Telescope on La Palma, during the 1999/00 and 2000/01 observing seasons. In this data set, 14 microlensing events have been detected, 2 of which have been reported previously by the POINT-AGAPE group, and 12 are new events. The timescale distribution of the events is consistent with halo lensing dominating in the outer parts of M31; from the spatial distribution of the events there is some evidence for a far/near side asymmetry. Although the number of events is still quite small, our results are consistent with a significant population of compact objects in the M31 halo.

De Jong, J T A; Crotts, A P S; Sackett, P D; Sutherland, W J; Uglesich, R R; Baltz, E A; Cseresnjes, P; Gyuk, G; Widrow, L M; Jong, Jelte T.A. de; Kuijken, Konrad H.; Crotts, Arlin P.S.; Sackett, Penny D.; Sutherland, Will J.; Uglesich, Robert R.; Baltz, Edward A.; Cseresnjes, Patrick; Gyuk, Geza; Widrow, Lawrence M.

2004-01-01

56

Vishal Mega-Mart- An Overview  

Directory of Open Access Journals (Sweden)

Full Text Available 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. This excludes direct interface between the manufacturer and institutional buyers such as the government and other bulk customers. A retailer is one who stocks the producer’s goods and is involved in the act of selling it to the individual consumer, at a margin of profit. As such, retailing is the last link that connects the individual consumer with the manufacturing and distribution chain. Some of the key features of retailing include: -Selling directly to customers without having any intermediaries-Selling in smaller units / quantities, breaking the bulk-Present in neighborhood or in the location which is quite convenient to the customers.-Very high in numbers-Recognized by their service levels-Fitting any size and or locationThe objective of this article is to study the Marketing Mix and Shareholding pattern of Vishal Mega-Mart, a renowned name in Retail Industry of India.

Shikha Gupta

2010-12-01

57

Persistence Mechanisms of Conjugative Plasmids  

DEFF Research Database (Denmark)

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 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-free cells. Finally, various molecular adaptations of plasmids to better match the genetic background of their bacterial host cell will be described.

Bahl, Martin Iain; Hansen, Lars H.

2009-01-01

58

An improved method for including upper size range plasmids in metamobilomes  

DEFF Research Database (Denmark)

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). Throughout the study, we used two model plasmids, a 4.4 Kbp cloning vector (pBR322), and a 56 Kbp conjugative plasmid (pKJK10), to represent lower- and upper plasmid size ranges, respectively. Subjecting a mixture of these plasmids to the overall isolation protocol revealed a 34-fold over-amplification of pBR322 after MDA. To address this bias, we propose the addition of an electroelution step that separates different plasmid size ranges prior to MDA in order to reduce size-dependent competition during incubation. Subsequent analyses of metamobilome data from wastewater spiked with the model plasmids showed in silica recovery of pKJK10 to be very poor with the established method and a 1,300-fold overrepresentation of pBR322. Conversely, complete recovery of pKJK10 was enabled with the new modified protocol although considerable care must be taken during electroelution to minimize cross-contamination between samples. For further validation, non-spiked wastewater metamobilomes were mapped to more than 2,500 known plasmid genomes. This displayed an overall recovery of plasmids well into the upper size range (median size: 30 kilobases) with the modified protocol. Analysis of de novo assembled metamobilome data also suggested distinctly better recovery of larger plasmids, as gene functions associated with these plasmids, such as conjugation, was exclusively encoded in the data output generated through the modified protocol. Thus, with the suggested modification, access to a large uncharacterized pool of accessory elements that reside on medium-to-large plasmids has been improved. © 2014 Norman et al.

Norman, Anders; Riber, Leise

2014-01-01

59

Likelihood Analysis for Mega-Pixel Maps  

CERN Document Server

The derivation of cosmological parameters from astrophysical data sets routinely involves operations counts which scale as O(N^3) where N is the number of data points. Currently planned missions, including MAP and Planck, will generate sky maps with N = 10^6 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 minimum-variance pixel basis. The algorithm uses a conjugate gradient approach to evaluate chi-squared and a geometric approximation to evaluate the determinant. Monte Carlo simulations provide an exact 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^{3/2}) operations and O(N) storage for each likelihood evaluation, and allows for significant parallel computation.

Kogut, A J

1999-01-01

60

Atlas Test Beam And MicroMegas Detectors  

CERN Document Server

MicroMegas is one of the detector technologies (along with the small Thin Gap Chambers) that has been chosen for precision tracking and triggering purposes of the ATLAS muon forward detectors in the view of LHC luminosity increase. To fulfill the requirements of such upgrade, several prototype MicroMegas detectors were tested in recent test beam campaigns with high energy hadron beams at CERN. The following report describes the way that the MicroMegas detectors work and the procedure of the test beam at Atlas experiment at Cern .

Koutsoupi, Soultana

2014-01-01

61

Geomorphological hierarchies for complex mega-dunes and their implications for mega-dune evolution in the Badain Jaran Desert  

Science.gov (United States)

The evolution of mega-dunes is sometimes attributed to factors other than the wind but evidence for this is lacking. It is assumed that the dominance of wind in maintaining the evolution of mega-dunes should be characterized by regular height-spacing relationships that have been found for simple dunes or wind ripples which are dominantly formed by the wind. In this context, we studied the height-spacing relationship for the complex reversing mega-dunes in the Badain Jaran Desert, which features the tallest mega-dunes in the world. The complex mega-dunes were divided into three hierarchical orders according to the cumulative probability plots of dune height and spacing measurements, and the coefficients of variability of dune heights and spacings were in accordance with values reported for other deserts. The relationship between dune spacing and height for all the three orders of dunes could be expressed reasonably well by a uniform linear function that was also applied to the height-wavelength relationship for wind ripples in other deserts. This relationship was found to be similar to those for several other deserts and subaqueous bedforms. This implies that there should be few unique factors in maintaining the evolution of complex mega-dunes in the Badain Jaran Desert compared with the superimposed simple dunes and dunes in other deserts, dune fields and subaqueous bedforms, and that the tallest mega-dunes on the earth can be maintained by the wind.

Dong, Zhibao; Qian, Guangqiang; Luo, Wanyin; Zhang, Zhengcai; Xiao, Shengchun; Zhao, Aiguo

2009-05-01

62

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

OpenAIRE

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 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 Enterobacteriacea...

Carattoli, Alessandra; Zankari, Ea; Garci?a-ferna?ndez, Aurora; Voldby Larsen, Mette; Lund, Ole; Villa, Laura; Møller Aarestrup, Frank; Hasman, Henrik

2014-01-01

63

Responding to Threats of Climate Change Mega-Catastrophes  

OpenAIRE

There is a low but uncertain probability that climate change could trigger “mega-catastrophes,” severe and at least partly irreversible adverse effects across broad regions. This paper first discusses the state of current knowledge and the defining characteristics of potential climate change mega-catastrophes. While some of these characteristics present difficulties for using standard rational choice methods to evaluate response options, there is still a need to balance the benefits and c...

Kousky, Carolyn; Rostapshova, Olga V.; Toman, Michael; Zeckhauser, Richard Jay

2010-01-01

64

Rare case of dystrophia myotonica with mega cisterna magna.  

Science.gov (United States)

Myotonic dystrophy is also known as dystrophia myotonica (DM). The condition is composed of at least two clinical disorders with overlapping phenotypes and distinct molecular genetic defects: myotonic dystrophy type 1, the classic disease originally described by Steinert, and myotonic dystrophy type 2, also called proximal myotonic myopathy (PROMM). Mega cisterna magna is thought to be an anatomic variant with no clinical significance. We report a rare case of type 1 dystrophia myotonica in combination with mega cisterna magna. PMID:22848312

Pandya, Hetal; Lakhani, Jitendra; Mehta, Jigar; Dodhania, Jimmy

2012-01-01

65

Rare case of dystrophia myotonica with mega cisterna magna  

Directory of Open Access Journals (Sweden)

Full Text Available Myotonic dystrophy is also known as dystrophia myotonica (DM. The condition is composed of at least two clinical disorders with overlapping phenotypes and distinct molecular genetic defects: myotonic dystrophy type 1, the classic disease originally described by Steinert, and myotonic dystrophy type 2, also called proximal myotonic myopathy (PROMM. Mega cisterna magna is thought to be an anatomic variant with no clinical significance. We report a rare case of type 1 dystrophia myotonica in combination with mega cisterna magna.

Hetal Pandya

2012-04-01

66

Ultrasonographic appearance of the mega cisterna magna in the newborn.  

Science.gov (United States)

The mega cisterna magna is a congenital developmental malformation which in the majority of instances is symptomless and does not require further study or surgical treatment. However, differential diagnosis with other cerebellar diseases is often necessary especially in newborn infants. Ultrasonographic recognition of the mega cisterna magna in a newborn infant is reported. The reported case demonstrates the usefulness of the ultrasonographic technique in the study of the posterior cranial fossa abnormalities of newborn infants. PMID:3912472

Cerisoli, M; Sandri, F; Giulioni, M; Pilu, G; Cocchi, G; Bovicelli, L; Salvioli, G P; Alvisi, C

1985-01-01

67

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

DEFF Research Database (Denmark)

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 and scan speed) and spatial reach (EPS yield, conjugal pilus length) are more important for successful plasmid invasionthan the recipients' growth rate or the probability of segregational loss. While this study identifies one factor that can limit plasmid invasion in biofilms, the new individual?based framework introduced in this work is a powerful tool that enables one to test additional hypotheses on the spread and role of plasmids in microbial biofilms.

Merkey, Brian; Lardon, Laurent

2011-01-01

68

Characterization of concatemeric plasmids of Neisseria gonorrhoeae.  

OpenAIRE

Three strains of Neisseria gonorrhoeae carried novel plasmids of 7.8 megadaltons (mdal) molecular mass in addition to plasmids previously observed in this organism. The presence of the 7.8-mdal plasmids was not accompanied by any distinguishable phenotype in the strain possessing them. Analysis of plasmid DNA with restriction endonucleases showed that these plasmids were composed of three directly repeated copies of a 2.6-mdal cryptic plasmid frequently found in N. gonorrhoeae. In addition, t...

Johnson, S. R.; Anderson, B. E.; Biddle, J. W.; Perkins, G. H.; Dewitt, W. E.

1983-01-01

69

Yeast cohesin complex embraces 2 micron plasmid sisters in a tri-linked catenane complex  

OpenAIRE

Sister chromatid cohesion, crucial for faithful segregation of replicated chromosomes in eukaryotes, is mediated by the multi-subunit protein complex cohesin. The Saccharomyces cerevisiae plasmid 2 micron circle mimics chromosomes in assembling cohesin at its partitioning locus. The plasmid is a multi-copy selfish DNA element that resides in the nucleus and propagates itself stably, presumably with assistance from cohesin. In metaphase cell lysates, or fractions enriched for their cohesed sta...

Ghosh, Santanu K.; Huang, Chu-chun; Hajra, Sujata; Jayaram, Makkuni

2009-01-01

70

Top, GigaZ, MegaW  

Energy Technology Data Exchange (ETDEWEB)

We review the physics potential of top mass measurements and the GigaZ/MegaW options of the International Linear Collider (ILC) for probing New Physics models and especially the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that the anticipated experimental accuracies at the ILC for the top-quark mass, mt, the W boson mass, M{sub W}, and the effective leptonic weak mixing angle, sin{sup 2} {theta}{sub eff}, will provide a high sensitivity to quantum effects of New Physics. In particular, a new and more precise measurement of sin{sup 2} {theta}{sub eff}, for which the experimental central value is currently obtained from an average where the most precise single measurements differ by more than three standard deviations, could lead to a situation where both the Standard Model and the MSSM in its most general form are ruled out. Alternatively, the precision measurements may resolve virtual effects of SUSY particles even in scenarios where the SUSY particles are so heavy that they escape direct detection at the LHC and the first phase of the ILC. (orig.)

Heinemeyer, S. [Instituto de Fisica de Cantabria, Santander (Spain); Weiglein, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2010-08-15

71

MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0.  

Science.gov (United States)

We announce the release of the fourth version of MEGA software, which expands on the existing facilities for editing DNA sequence data from autosequencers, mining Web-databases, performing automatic and manual sequence alignment, analyzing sequence alignments to estimate evolutionary distances, inferring phylogenetic trees, and testing evolutionary hypotheses. Version 4 includes a unique facility to generate captions, written in figure legend format, in order to provide natural language descriptions of the models and methods used in the analyses. This facility aims to promote a better understanding of the underlying assumptions used in analyses, and of the results generated. Another new feature is the Maximum Composite Likelihood (MCL) method for estimating evolutionary distances between all pairs of sequences simultaneously, with and without incorporating rate variation among sites and substitution pattern heterogeneities among lineages. This MCL method also can be used to estimate transition/transversion bias and nucleotide substitution pattern without knowledge of the phylogenetic tree. This new version is a native 32-bit Windows application with multi-threading and multi-user supports, and it is also available to run in a Linux desktop environment (via the Wine compatibility layer) and on Intel-based Macintosh computers under the Parallels program. The current version of MEGA is available free of charge at (http://www.megasoftware.net). PMID:17488738

Tamura, Koichiro; Dudley, Joel; Nei, Masatoshi; Kumar, Sudhir

2007-08-01

72

Molecular biology of spiroplasma plasmids.  

OpenAIRE

With one exception, all spiroplasma strains examined contained extrachromosomal DNA, most of which was in the form of covalently closed circular plasmids. One plasmid, pIJ2000, carried by Spiroplasma citri strain ASP-1, was purified and characterized and used to probe for related plasmids in other strains. Unsuccessful attempts were made to clone pIJ2000 into Escherichia coli using the vectors pAT153 and pBR322. However, spiroplasma chromosomal DNA fragments could be cloned without difficulty.

Barber, C. E.; Archer, D. B.; Daniels, M. J.

1983-01-01

73

IncA/C plasmids harboured in serious multidrug-resistant Vibrio cholerae serogroup O139 strains in China.  

Science.gov (United States)

Vibrio cholerae serogroup O139 emerged in 1992 and is one of two major serogroups to have caused cholera epidemics. After 1998, serious multidrug-resistant (MDR) O139 strains quickly became common in China, showing a multidrug resistance profile to eight antibiotics. It is a great threat to public health, and elucidation of its mechanisms of resistance will provide a helpful guide for the clinical treatment and prevention of cholera. In this study, mega-plasmids from MDR V. cholerae O139 strains were identified by pulsed-field gel electrophoresis (PFGE) without enzyme digestion. One plasmid was isolated and sequenced, belonging to the IncA/C family. Ten antibiotic resistance genes were found in the MDR regions, including a blaTEM-20 gene, and these genes endowed the host with resistance to seven antibiotics. This kind of plasmid was positive in 71.2% (198/278) of toxigenic O139 strains, and the rate of plasmid positivity was consistent with the yearly change in MDR rates of these strains. This study reveals an important role of the IncA/C family plasmid in the spread of multiple antibiotic resistance of epidemic V. cholerae serogroup O139 strains, which has recombined with plasmids from different bacterial species and transferred among V. cholerae strains. PMID:25532743

Wang, Ruibai; Yu, Dong; Zhu, Lianhui; Li, Jie; Yue, Junjie; Kan, Biao

2015-03-01

74

The Mega-Terrorism - The Challenge of the Third Millennium  

Directory of Open Access Journals (Sweden)

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.

Daniel Andri?an

2011-06-01

75

Yeast cohesin complex embraces 2 micron plasmid sisters in a tri-linked catenane complex.  

Science.gov (United States)

Sister chromatid cohesion, crucial for faithful segregation of replicated chromosomes in eukaryotes, is mediated by the multi-subunit protein complex cohesin. The Saccharomyces cerevisiae plasmid 2 micron circle mimics chromosomes in assembling cohesin at its partitioning locus. The plasmid is a multi-copy selfish DNA element that resides in the nucleus and propagates itself stably, presumably with assistance from cohesin. In metaphase cell lysates, or fractions enriched for their cohesed state by sedimentation, plasmid molecules are trapped topologically by the protein ring formed by cohesin. They can be released from cohesin's embrace either by linearizing the DNA or by cleaving a cohesin subunit. Assays using two distinctly tagged cohesin molecules argue against the hand-cuff (an associated pair of monomeric cohesin rings) or the bracelet (a dimeric cohesin ring) model as responsible for establishing plasmid cohesion. Our cumulative results most easily fit a model in which a single monomeric cohesin ring, rather than a series of such rings, conjoins a pair of sister plasmids. These features of plasmid cohesion account for its sister-to-sister mode of segregation by cohesin disassembly during anaphase. The mechanistic similarities of cohesion between mini-chromosome sisters and 2 micron plasmid sisters suggest a potential kinship between the plasmid partitioning locus and centromeres. PMID:19920123

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

2010-01-01

76

Structure of mega-hemocyanin reveals protein origami in snails.  

Science.gov (United States)

Mega-hemocyanin is a 13.5 MDa oxygen transporter found in the hemolymph of some snails. Similar to typical gastropod hemocyanins, it is composed of 400 kDa building blocks but has additional 550 kDa subunits. Together, they form a large, completely filled cylinder. The structural basis for this highly complex protein packing is not known so far. Here, we report the electron cryomicroscopy (cryo-EM) structure of mega-hemocyanin complexes from two different snail species. The structures reveal that mega-hemocyanin is composed of flexible building blocks that differ in their conformation, but not in their primary structure. Like a protein origami, these flexible blocks are optimally packed, implementing different local symmetries and pseudosymmetries. A comparison between the two structures suggests a surprisingly simple evolutionary mechanism leading to these large oxygen transporters. PMID:25482543

Gatsogiannis, Christos; Hofnagel, Oliver; Markl, Jürgen; Raunser, Stefan

2015-01-01

77

Mega-masers, Dark Energy and the Hubble Constant  

International Nuclear Information System (INIS)

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

78

Characterization of the particulate air pollution in contrasted mega cities  

International Nuclear Information System (INIS)

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)

79

The employment and fiscal effects of Michigan's MEGA tax credit program  

OpenAIRE

This paper estimates that Michigan's MEGA tax credit program to attract and retain businesses has large employment and fiscal benefits. MEGA provides discretionary tax credits to businesses, with the tax credit tied to the personal income taxes paid by employees on the new or retained jobs. We estimate the economic effects of MEGA using the Upjohn Institute's REMI model, and the research literature on how business location decisions respond to taxes. We estimate the fiscal effects of MEGA bas...

Bartik, Timothy J.; Erickcek, George

2010-01-01

80

Reversible atrial fibrillation secondary to a mega-oesophagus  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Atrial fibrillation (AF is the most common cardiac arrhythmia, and it increases in prevalence with advancing age to about 5% in people older than 65 years. Case presentation We present a rare case of atrial fibrillation secondary to a mega-oesophagus occurring in an 84-years-old Caucasian woman. The patient had a history of progressive dysphagia and the accumulation of food debris lead to mega-oesophagus. Conclusion The diagnosis was made by barium swallow and electrocardiogram; evacuations of 300 ml of the food debris lead to complete resolution of the arrhythmia. The possible aetiology leading to this AF is discussed.

Hopper Colin

2006-12-01

81

Relationship between Nif plasmids of fast-growing Rhizobium species and Ti plasmids of Agrobacterium tumefaciens.  

OpenAIRE

By use of the Southern blot hybridization technique the extent of DNA homology was determined between the Nif plasmid of a number of fast-growing Rhizobium species and Ti plasmids of the octopine (pTiAch5) and nopaline (pTiC58) type. DNA sequences common to these plasmids were located on functional maps of the Ti plasmids. No homology between Nif plasmids and the T region of Ti plasmids was detected.

Prakash, R. K.; Schilperoort, R. A.

1982-01-01

82

Strategies simulation model for the gas business chain MEGAS  

International Nuclear Information System (INIS)

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 affet, to predict how these changes could affect its business affairs and to visualize different return scenarios

83

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

International Nuclear Information System (INIS)

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.)

84

Distribution of virulence plasmids within Salmonellae.  

Science.gov (United States)

The virulence region of the Salmonella dublin 50 MDa plasmid shared homology with 678 of 1021 salmonellae tested in colony hybridization experiments. The majority of S. dublin, S. typhimurium and S. enteritidis isolates tested hybridized with the region whereas, with the exception of S. hessarek, S. pullorum and S. gallinarum, other serotypes did not. Homologous virulence regions were plasmid encoded. In S. typhimurium a common 60 MDa plasmid was present in all phage types tested but not in DT4, DT37 and DT170. Smaller plasmids showing partial homology were found in DT12, DT18, DT193 and DT204C. In S. enteritidis a distinct plasmid profile for each of eight phage types was observed. Hybridizing plasmids were found in DT3, DT4, DT8, DT9 and DT11 whereas DT7, which was plasmid free, and DT10 and DT14, which harboured plasmids, did not hybridize. The extent of homology shared between S. dublin, S. typhimurium and S. enteritidis virulence plasmids was about 10 MDa and appeared conserved. Virulence plasmids from S. typhimurium and S. enteritidis did not show homology with a region of the S. dublin 50 MDa plasmid which was not associated with virulence functions whereas plasmids of about 24 MDa and 38 MDa in some S. typhimurium phage types did. The association of conserved virulence regions upon differing plasmids within salmonellae is discussed with reference to possible mechanisms of distribution and evolution of virulence genes. PMID:2621439

Woodward, M J; McLaren, I; Wray, C

1989-03-01

85

The Global Issue "MEGA-URBANIZATION": AN Unsolvable Challenge for Stakeholders, Researchers and Residents?  

Science.gov (United States)

This study aims at discussing the complex, multi-dimensional issue of the global phenomenon of urbanization. Based on a theoretical review and discussion on the situation of cities, the causes, dimensions and consequences of urban growth the idea is to raise the main questions for future activities to meet this challenge. For it a pragmatic and holistic framework is proposed to systematize the manifold approaches and to stimulate discussions on this issue addressing inter- and transdisciplinary thinking.

Taubenböck, H.

2011-08-01

86

Plasmid profiling of bacterial isolates from confined environments  

Science.gov (United States)

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 different classes of antibiotics including aminoglycosides, penicillins, macrolides and chloramphenicol. Whether these antibiotic resistance determinants are plasmid-bound and whether these traits can be transferred to other bacteria is under investigation.

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

87

Instability of dicentric plasmids in yeast.  

OpenAIRE

Dicentric plasmids containing either two copies of centromere 4 or one copy of centromere 4 and one copy of centromere 3 in the yeast plasmid vector YRp17 were constructed in vitro and introduced into yeast cells by DNA transformation. The resulting colonies were heterogeneous for a mixed population of rearranged plasmids. The rearrangements always involved deletion of one or both centromere sequences originally present on the plasmid. Heterogeneity was due to the continued production of dele...

Mann, C.; Davis, R. W.

1983-01-01

88

Predicting Plasmid Promiscuity Based on Genomic Signature? ‡  

OpenAIRE

Despite the important contribution of self-transmissible plasmids to bacterial evolution, little is understood about the range of hosts in which these plasmids have evolved. Our goal was to infer this so-called evolutionary host range. The nucleotide composition, or genomic signature, of plasmids is often similar to that of the chromosome of their current host, suggesting that plasmids acquire their hosts’ signature over time. Therefore, we examined whether the evolutionary host range of pl...

Suzuki, Haruo; Yano, Hirokazu; Brown, Celeste J.; Top, Eva M.

2010-01-01

89

Plasmids in several strains of Deinococcus radiodurans.  

Science.gov (United States)

Deinococcus radiodurans is known as a radioresistant bacterium. For the construction of the shuttle vector, plasmids of this bacterium were isolated and investigated. At least two new plasmids in the cells of D. radiodurans MR1, KR1 and Sark were found in this experiment. However, a common plasmid among MR1, KR1 and Sark strains could not be found. These plasmids would be useful for the construction of the shuttle vector for cloning radioresistant genes of this bacterium. PMID:8016301

Kikuchi, M; Kitayama, S; Sjarief, S H; Watanabe, H

1994-07-01

90

R-Plasmid Transfer in Zymomonas mobilis  

OpenAIRE

Conjugal transfer of three IncP1 plasmids and one IncFII plasmid into strains of the ethanol-producing bacterium Zymomonas mobilis was obtained. These plasmids were transferred at high frequencies from Escherichia coli and Pseudomonas aeruginosa into Z. mobilis and also between different Z. mobilis strains, using the membrane filter mating technique. Most of the plasmids were stably maintained in Z. mobilis, although there was some evidence of delayed marker expression. A low level of chromos...

Skotnicki, Mary L.; Tribe, David E.; Rogers, Peter L.

1980-01-01

91

A plasmid in Legionella pneumophila.  

OpenAIRE

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.

Knudson, G. B.; Mikesell, P.

1980-01-01

92

Plasmid required for virulence of Agrobacterium tumefaciens.  

Science.gov (United States)

The irreversible loss of crown gall-inducing ability of Agrobacterium tumefaciens strain C-58 during growth at 37 C is shown to be due to loss of a large plasmid (1.2 X 10-8 daltons). The gene responsible for this high rate of plasmid loss at elevated temperatures seems to be located on the plasmid. In addition, another spontaneous avirulent variant, A. tumefaciens strain IIBNV6 is shown to lack the virulence plasmid which its virulent sibling strain, IIBV7, possesses. Deoxyribonucleic acid reassociation measurements prove that the plasmid is eliminated, not integrated into the chromosome, in both of the avirulent derivatives. Transfer of virulence from donor strain C-58 to avirulent recipient strain A136 results from the transfer of a plasmid, which appears identical to the donor plasmid by deoxyribonucleic acid reassociation measurements. The transfer of virulence in another cross, K27 X A136, was also shown to result from the transfer of a large plasmid. These findings establish unequivocally that the large plasmid determines virulence. Two additional genetic determinants have been located on the virulence plasmid of A. tumefaciens strain C-58: the ability to utilize nopaline and sensitivity to a bacteriocin produced by strain 84. The latter trait can be exploited for selection of avirulent plasmid-free derivatives of strain C-58. The trait of nopaline utilization appears to be on the virulence plasmid also in strains IIBV7 and K27. PMID:1141196

Watson, B; Currier, T C; Gordon, M P; Chilton, M D; Nester, E W

1975-07-01

93

Elimination of plasmids by new 4-quinolones.  

OpenAIRE

Nalidixic acid and six of the new 4-quinolones eliminated F'lac and various native R plasmids from Escherichia coli at one half or one quarter the MIC. Four of eight plasmids tested were cured by all derivatives, with frequencies from 10 to 98%. Quinolones did not eliminate all plasmids that were cured by novobiocin, and vice versa.

Weisser, J.; Wiedemann, B.

1985-01-01

94

Building mosaics of therapeutic plasmid gene vectors.  

Science.gov (United States)

Plasmids are circular or linear DNA molecules propagated extra-chromosomally in bacteria. Evolution shaped plasmids are inherently mosaic structures with individual functional units represented by distinct segments in the plasmid genome. The patchwork of plasmid genetic modules is a convenient template and a model for the generation of artificial plasmids used as vehicles for gene delivery into human cells. Plasmid gene vectors are an important tool in gene therapy and in basic biomedical research, where these vectors offer efficient transgene expression in many settings in vitro and in vivo. Plasmid vectors can be attached to nuclear directing ligands or transferred by electroporation as naked DNA to deliver the payload genes to the nuclei of the target cells. Transgene expression silencing by plasmid sequences of bacterial origin and immune stimulation by bacterial unmethylated CpG motifs can be avoided by the generation of plasmid-based minimized DNA vectors, such as minicircles. Systems of efficient site-specific integration into human chromosomes and stable episomal maintenance in human cells are being developed for further reduction of the chances for transgene silencing. The successful generation of plasmid vectors is governed by a number of vector design rules, some of which are common to all gene vectors, while others are specific to plasmid vectors. This review is focused both on the guiding principles and on the technical know-how of plasmid gene vector design. PMID:22023476

Tolmachov, Oleg E

2011-12-01

95

Characterization of plasmids in Erwinia stewartii.  

OpenAIRE

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...

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

1981-01-01

96

Measurement of the Michel Parameters ? with the MEGA positron spectrometer  

International Nuclear Information System (INIS)

? is one of the Michel Parameters in the theoretical expression for the differential decay rate of polarized muons. The MEGA collaboration has recently conducted an experiment that should improve the precision of ? by at least a factor of 2 from its current best value, ? = 0.7518 ± 0.0026. In this experiment, the energies of decay positions were measured. ? can be extracted from the energy spectrum by comparing it with that of Monte Carlo simulations. The experiment was carried out with the existing MEGA positron spectrometer, which consists of 180 strips of plastic scintillator forming two hollow barrels and 8 cylindrically shaped MWPCs arranged such that seven smaller ones surround a larger central one. To understand and elminate possible sources of systematic error, 6 modes of data were taken during the run. Following a brief discussion of the experimental setup, the authors will discuss the major systematic effects and the current status of the data analysis

97

Los Alamos National Laboratory: MegaMath for Elementary Students  

Science.gov (United States)

MegaMath is a project of the Computer Research and Applications Group at Los Alamos National Laboratory that aims to make mathematics accessible to young children. The collaborative project represents the work of classroom teachers, mathematicians, students in education and computer science, elementary school and high school students, school administrators, computer scientists, and parents. An image map is used to invite viewers to explore topics in mathematics, try out games, and read about the project or browse the glossary and reference section. Teachers will find some interesting activities posted, along with related materials on: the Big Ideas and Key Concepts, Background Info, Vocabulary, NCTM Standards, Evaluation, Materials and Preparation, and information For Further Study. MegaMath invites others to join the collaboration via the Internet.

98

The impact of mega sports events on the stock markets  

OpenAIRE

This study attempts to estimate the impact of mega sports events organization on the stock market. For this purpose, there were selected seven sporting events taking place in the World Cup and European Football Championships and summer and winter Olympic Games. Next their impact on national equity markets represented by the major stock indices was determined. The study was conducted in two periods of research, ie the date of publication decision to hold an event and during the ...

Zawadzki, Krystian

2013-01-01

99

Rare case of dystrophia myotonica with mega cisterna magna  

OpenAIRE

Myotonic dystrophy is also known as dystrophia myotonica (DM). The condition is composed of at least two clinical disorders with overlapping phenotypes and distinct molecular genetic defects: myotonic dystrophy type 1, the classic disease originally described by Steinert, and myotonic dystrophy type 2, also called proximal myotonic myopathy (PROMM). Mega cisterna magna is thought to be an anatomic variant with no clinical significance. We report a rare case of type 1 dystrophia myotonica in c...

Hetal Pandya; Jitendra Lakhani; Jigar Mehta; Jimmy Dodhania

2012-01-01

100

The Mega-Terrorism - The Challenge of the Third Millennium  

OpenAIRE

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 tha...

Daniel Andri?an

2011-01-01

101

State of the art: integrating services for mega events  

Scientific Electronic Library Online (English)

Full Text Available This paper describes the state of the art of a simplified model for integration of services in mega events. The project context, which was financed by the National Research Council – CNPq, is divided into six major areas or functional groups: Urban Mobility, Tourism, Airports, Security, Energy and T [...] elecommunications. The proposal is described in layers, as an infrastructure model of integration and services evaluation, describing its main layers and interaction processes. The proposal described in this paper is restricted to the telecommunication subproject; however, in the modeling of the scenario for the study case, it was necessary to consider requirements and variables that are common to all subprojects. In the specification process of these requirements, we noticed important processes that interact with some sectors in the city of São Paulo; however, in the mean time, we noticed some failures regarding the integration and collaboration performed by administrative elements of stadiums as a main focus in the mega event and part of our case study. Currently, the proposal is in its first version as open software for the evaluation of the services quality and the mega event infrastructure through the use of performance indicators.

Jorge R. B., Garay; Gustavo M., Calixto; Alexandre M. De, Oliveira; Marcelo K., Zuffo.

2014-08-01

102

The mechanism of plasmid curing in bacteria.  

Science.gov (United States)

Bacterial plasmids have a major impact on metabolic function. Lactose fermentation of E. coli or hemolysin B transporter expressed by the plasmids that carry these respective genes could be readily obviated by heterocyclic compounds that readily bind to plasmid DNA. These compounds could also reverse the resistance to antibiotics of E. coli, Enterobacter, Proteus, Staphylococcus and Yersinia strains by eliminating plasmids. However, the frequency and extent of this effect was significantly less than might have been expected based on a complex interaction with plasmid DNA. The effects of heterocyclic compounds on the plasmids responsible for the virulence of Yersinia and A. tumefaciens, or on nodulation, nitrogen fixation of Rhizobia accounted for the elimination of 0.1 to 1.0 % of plasmids present in the populations studied. Bacterial plasmids can be eliminated from bacterial species grown as pure or mixed bacterial cultures in the presence of sub-inhibitory concentrations of non-mutagenic heterocyclic compounds. The antiplasmid action of the compounds depends on the chemical structure of amphiphillic compounds having a planar ring system with substitution in the L-molecular region. A symmetrical pi-electron conjugation at the highest occupied molecular orbitals favours the antiplasmid effect. The antiplasmid effect of heterocyclic compounds is expressed differentially in accordance with the structural form of the DNA to which they bind. In this manner "extrachromosomal" plasmid DNA that exists in a superhelical state binds more compound than its linear or open-circular form; and least to the chromosomal DNA of the bacterium, that carries the plasmid. It can also be noted that these compounds are not mutagenic and their antiplasmid effects correlate with the energy of HOMO-orbitals. Plasmid elimination is considered also to take place in ecosystems containing numerous bacterial species. This opens up a new perspective in rational drug design against bacterial plasmids. The inhibition of conjugational transfer of antibiotic resistance plasmid can be exploited to reduce the spread of antibiotic resistance plasmid in the ecosystem. Inhibition of plasmid replication at various stages, as shown in the "rolling circle" model (replication, partition, conjugal transfer) may also be the theoretical basis for the elimination of bacterial virulence in the case of plasmid mediated pathogenicity and antibiotic resistance. The large number of compounds tested for antiplasmid effects provides opportunities for QSAR studies in order to find a correlation between the antiplasmid effect and the supramolecular chemistry of these plasmid curing compounds. Plasmid elimination in vitro provides a method of isolating plasmid free bacteria for biotechnology without any risk of inducing mutations. PMID:16842214

Spengler, Gabriella; Molnár, Annamária; Schelz, Zsuzsanna; Amaral, Leonard; Sharples, Derek; Molnár, Joseph

2006-07-01

103

Acquisition of antibiotic resistance plasmids by enterohemorrhagic Escherichia coli O157:H7 within rumen fluid.  

Science.gov (United States)

The emergence of antibiotic resistance among important foodborne pathogens like Escherichia coli O157:H7 has become an important issue with regard to food safety. In contrast to the case for Salmonella, antibiotic resistance has been slow in its development in E. coli O157:H7 despite the presence of mobile antibiotic resistance genes in other E. coli organisms that inhabit the same animal host. We set out to determine if rumen fluid influences the transfer of plasmid-mediated, antibiotic resistance to E. coli O157:H7. A commensal E. coli strain from a dairy cow was transformed with conjugative R plasmids and served as the donor in matings with naladixic acid-resistant E. coli O157:H7. R plasmids were transferred from the donor E. coli strain to E. coli O157:H7 in both Luria-Bertani (LB) broth and rumen fluid. R plasmids were transferred at a higher frequency to E. coli O157:H7 during 6 h of incubation in rumen fluid at rates comparable to those in LB broth, indicating that conditions in rumen fluid favor the transfer of the plasmids to E. coli O157. This finding suggests that the cow's rumen is a favorable environment for the genetic exchange of plasmids between microflora and resident E. coli O157:H7 in the bovine host. PMID:12092718

Mizan, Shaikh; Lee, Margie D; Harmon, Barry G; Tkalcic, Suzana; Maurer, John J

2002-06-01

104

The MEGA [Muon decays into an Electron and a GAmma ray] hardware trigger system  

International Nuclear Information System (INIS)

The MEGA experiment is designed to search for the rare decay ? ? e ? with a branching ratio sensitivity of /approximately/10-13. As is typical of rare-decay experiments, extensive, online filtering of the data is required for MEGA. The MEGA experiment uses a hardware pattern-recognition system based on Programmable Array Logic (PAL) devices. Additional events are eliminated in an online ACP system before data are written to tape. The MEGA trigger system is generally applicable where high-rate, short-propagation-delay trigger systems are required. This report contains an introduction to the MEGA experiment, a discussion of the MEGA hardware trigger system and a discussion of the system's measured performance. 4 refs., 3 figs

105

The Political Risk of Oil and Gas Mega Projects : A Descriptive Empirical Analysis  

OpenAIRE

Two elements can be seen to evolve progressively with globalization: political risk and mega projects. Although a fair amount of research has been carried out in regards to political risk and mega projects as separate units of investigation, few studies have attempted to combine the two. This thesis fills a void in the existing literature by providing a specialized approach to political risk, focusing on political risk of oil and gas mega projects in particular. Drawing on a comprehensive dat...

Veflen, Martin Elton

2011-01-01

106

The repAC replication system of the Rhizobium leguminosarum pRL7 plasmid is functional: implications regarding the origin and evolution of repABC plasmids.  

Science.gov (United States)

The repABC replication/partitioning systems are commonly found in alpha-proteobacteria plasmids and in secondary chromosomes. All of the elements required for their replication and stable maintenance are encoded within a single transcription unit: the repABC operon. The repC gene encodes an initiator protein, while RepA, RepB and centromere-like sequence (parS) direct plasmid segregation. Strains containing two or more repABC plasmids are a common feature in some alpha proteobacteria groups, indicating that the repABC plasmid family embraces several incompatibility groups. Genes encoded within repABC operons are highly dynamic: each one possess its own distinctive phylogeny and homologous recombination events are common within these operons. Additionally, alpha-proteobacterial genomes contain repAB genes not associated with the ctRNA or with repC as well as plasmids whose replication depends on a ctRNA-repC module without the participation of repAB genes. Some alphaproteobacteria have repC genes clustered with other genes that are not involved in replication/partitioning functions. These atypical associations of genes could have an important role in the origin and diversification of new plasmids. Here we evaluated the functionality and possible evolutionary consequences of one of these atypical gene associations: the repAC genes present in the Rhizobium leguminosarum plasmid pRL7. The repAC genes are organized in an operon and they are capable of sustaining replication but in an unstable manner. RepC was essential for replication, and the origin of replication resides within its coding region. In contrast, RepA plays a minor role in the negative regulation of its own transcription. PMID:22975386

Pérez-Segura, Gabriela; Pérez-Oseguera, Angeles; Cevallos, Miguel A

2013-01-01

107

Homology among nearly all plasmids infecting three Bacillus species.  

OpenAIRE

We have surveyed naturally occurring plasmids in strains of Bacillus subtilis and the closely related species B. mojavensis and B. licheniformis. Previous studies have failed to find host-benefitting functions for plasmids of these species, suggesting that these plasmids are nonmutualistic. Only one type of plasmid was found in each plasmid-bearing strain, suggesting that most of the plasmids infecting these Bacillus species are in the same incompatibility group. A sample of 18 plasmids from ...

Zawadzki, P.; Riley, M. A.; Cohan, F. M.

1996-01-01

108

Plasmid transfer systems in the rhizobia.  

Science.gov (United States)

Rhizobia are agriculturally important bacteria that can form nitrogen-fixing nodules on the roots of leguminous plants. Agricultural application of rhizobial inoculants can play an important role in increasing leguminous crop yields. In temperate rhizobia, genes involved in nodulation and nitrogen fixation are usually located on one or more large plasmids (pSyms) or on symbiotic islands. In addition, other large plasmids of rhizobia carry genes that are beneficial for survival and competition of rhizobia in the rhizosphere. Conjugative transfer of these large plasmids thus plays an important role in the evolution of rhizobia. Therefore, understanding the mechanism of conjugative transfer of large rhizobial plasmids provides foundations for maintaining, monitoring, and predicting the behaviour of these plasmids during field release events. In this minireview, we summarize two types of known rhizobial conjugative plasmids, including quorum sensing regulated plasmids and RctA-repressed plasmids. We provide evidence for the existence of a third type of conjugative plasmid, including pRleVF39c in Rhizobium leguminosarum bv. viciae strain VF39SM, and we provide a comparison of the different types of conjugation genes found in members of the rhizobia that have had their genomes sequenced so far. PMID:19898531

Ding, Hao; Hynes, Michael F

2009-08-01

109

Plasmids in several strains of deinococcus radiodurans  

International Nuclear Information System (INIS)

Deinococcus radiodurans is known as a radioresistant bacterium. For the construction of the shuttle vector, plasmids of this bacterium were isolated and investigated. At least two plasmids in the cells of D. radiodurans MR1, KR1 and Sark were found in this experiment. However, a common plasmid among MR1, KR1 and Sark strains could not be found. These plasmids would be useful for the construction of the shuttle vector for cloning radioresistant genes of this bacterium. 13 refs., 2 figs., 1 tab

110

Characterization of conjugative plasmid EDP208.  

OpenAIRE

EDP208 is a conjugative plasmid belonging to incompatibility group IncF0 lac, A restriction endonuclease map of this plasmid was constructed using five restriction enzymes: BamHI, HindIII, PvuI, SstI, and XhoI. On the basis of these mapping studies, the plasmid was found to be 90 kilobases in length. Clones were constructed from four large HindIII fragments of plasmid EDP208. One fragment, HindIII-20.5, was found to contain the lac genes and the origin of vegetative replication (oriV). Anothe...

Finlay, B. B.; Paranchych, W.; Falkow, S.

1983-01-01

111

Plasmid-associated virulence of Salmonella typhimurium.  

OpenAIRE

We investigated the role of the 100-kilobase (kb) plasmid of Salmonella typhimurium in the virulence of this organism for mice. Three strains, LT2-Z, SR-11, and SL1344, which possessed 100-kb plasmids with identical restriction enzyme digestion profiles, were cured of their respective 100-kb plasmids after Tnmini-tet was used to label plasmids. Curing wild-type virulent strains SR-11 and SL1344 raised peroral 50% lethal doses from 3 x 10(5) and 6 x 10(4) CFU, respectively, to greater than 10(...

Gulig, P. A.; Curtiss, R.

1987-01-01

112

R Plasmids in Corynebacterium xerosis Strains  

OpenAIRE

Plasmids coding for resistance to chloramphenicol, erythromycin, kanamycin, streptomycin, and tetracycline have been found in strains of Corynebacterium xerosis isolated from patients with otitis media.

Kono, Megumi; Sasatsu, Masanori; Aoki, Takashi

1983-01-01

113

The Uruguayan Per mic mega flora. A synthesis  

International Nuclear Information System (INIS)

The Permian mega floras of Uruguay. A synthesis. An analysis of the impression and fossil wood floras from the Permian of Uruguay is given through a series of Tables. These show : (1) the list of taxa, (2) anatomical characters of the woods, (3) data on the micro floral associations, (4) paleoenvironmental information and (5) comparisons with contemporaneous Gondwana floras. The evolutionary degree of the woods is briefly analyzed where they correspond to the so-called transition xilotaphofloras as they present typical Paleozoic anatomical characters but with secondary xylem of more advanced characteristics. (author)

114

Mesozoic evolution of the Tisza Mega-unit  

Science.gov (United States)

The south-eastern part of the basement of the Pannonian Basin is made up of Variscan crystalline complexes and early Mesozoic formations showing striking affinity with the corresponding formations in the southern margin of the European Plate. This large composite structural unit, which is actually an exotic terrane of European Plate origin, has been named the Tisza Mega-unit. Based upon relevant data of the pre-Tertiary basement of southern Hungary the reconstruction of the position of the Tisza Terrane in the early Alpine evolutionary stages, the process of its separation and break-off from the European Plate, and results of its Eo-Alpine deformations are summarised in the present paper. In the Variscan and early Alpine evolutionary stages the area of the later Tisza Mega-unit was located at the margin of the European Plate. During Variscan orogeny terrane accretion led to intensive deformation and metamorphism in this belt. This was followed by transpressional tectonics and the development of molasse basins in the late and post-Variscan stages, and passive margin evolution after the Neotethys opening in the Middle Triassic. The separation of the Tisza Mega-unit began with incipient continental rifting along the axis of the later Ligurian-Penninic-Vahic oceanic branch in the Late Triassic. The end of terrigenous material deposition in the most external zones, and a coeval change in fossil assemblage, point to the separation of the Tisza Block from the European Plate in the Early Bathonian. Significant rotation of the Tisza Mega-unit and coeval paroxysm of alkaline rift-type basalt volcanism took place in the Early Cretaceous. In the mid-Cretaceous, due to the northward motion of the Adria Block and the related closure of the westernmost Neotethys basin, the extensional regime changed to a compressional one, leading to onset of the nappe stacking and low-grade regional metamorphism within the Tisza microplate. In the foreland of the nappe systems flexural basins came into existence that are characterised by flysch-type sedimentation. In the Early Tertiary the north-eastward motion of the Alcapa and Tisza + Dacia Blocks led to the formation of the present-day heterogeneous basement of the Pannonian Basin.

Haas, János; Péró, Csaba

115

How to make mega-cities energy efficient?  

Energy Technology Data Exchange (ETDEWEB)

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.

Aoki, Hitoshi; Aoki, Yoshitaka

2010-09-15

116

Meta, mega e retroanálises correlacionais: comparando dados primários em Psicologia / Correlational meta, mega and retroanalyses: comparing primary data in Psychology / Meta, mega y retroanálisis correlacionales: comparando datos primarios en Psicología  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Na tentativa de promover a transformação de informações em conhecimento, este artigo compara as meta-análises com duas de suas variantes, as mega-análises e as retroanálises, técnicas desenvolvidas para a síntese e a equiparação de resultados pouco precisos ou contraditórios. Enquanto as meta-anális [...] es referem-se à síntese dos resultados de diferentes pesquisas primárias, as mega-análises referem-se à síntese dos dados coletados por pesquisas primárias e as retroanálises à recriação e posterior síntese desses mesmos dados. Por meio de uma simulação, o Estudo 1 pareia o viés médio de meta, mega e retroanálises em função de nove diferentes configurações que variam conforme a quantidade de estudos empregados e do tamanho da amostra individual de cada um desses estudos, nas modalidades de dados completos, leve e severa ausência de dados. No Estudo 2, os mesmos dados utilizados na simulação de ausência severa foram empregados para testar a precisão de mega e retroanálises quando se realiza a imputação de dados. Os resultados apontam para uma leve superioridade geral das mega-análises, diferença essa que diminui, até desaparecer, em situações ideais. Abstract in spanish En la tentativa de fomentar la transformación de informaciones en conocimiento, este artículo compara los meta-análisis con dos de sus variantes, los mega-análisis y los retro-análisis, técnicas desarrolladas para la síntesis y la equiparación de resultados poco precisos o contradictorios. Mientras [...] los meta-análisis se refieren a la síntesis de los resultados de distintas investigaciones primarias, los mega-análisis se refieren a la síntesis de los datos recolectados por investigaciones primarias, y los retro-análisis, a una nueva creación y posterior síntesis de esos mismos datos. Por medio de una simulación, el Estudio 01 parea el sesgo medio de meta-, mega- y retro-análisis en función de nueve distintas configuraciones que varían según la cantidad de estudios llevados a cabo y el tamaño de la muestra individual de cada uno de esos estudios, en las modalidades de datos completos, leve y severa ausencia de datos. En el estudio 02, los mismos datos utilizados en la simulación de ausencia severa han sido empleados para testar la precisión de mega- y retro-análisis cuando se lleva a cabo la imputación de datos. Los resultados señalan hacia una leve superioridad general de los mega-análisis. Esa diferencia disminuye, hasta desaparecer, en situaciones ideales Abstract in english In an attempt to promote the transformation of information into knowledge, this article compares meta-analyses with two of its variants, mega-analyses and retro-analyses, techniques developed to summarize and compare results that are not very accurate or contradictory. While meta-analyses refer to t [...] he synthesis of results of different primary researches. mega-analyses refer to the synthesis of results collected by primary researches and retroanalyses, to the recreation and posterior synthesis of that data. Using a simulation, Study 1 pairs the average trends from meta, mega and retroanalyses regarding nine different configurations that vary according to the number of studies used and the size of the individual sample of each of those studies, in the full data, light data and severe lack of data modes. In Study 2, the same data used in the simulation of severe lack of data were used to test the accuracy of mega and retroanalyses when performing data imputation. The results show a slight general superiority of mega-analyses, a difference that fades away in ideal situations.

Igor Reszka, Pinheiro; Roberto Moraes, Cruz.

2014-06-01

117

A Positive Study on the Residents' Tourism Expectation of Shanghai EXPO  

Directory of Open Access Journals (Sweden)

Full Text Available The attitude, cognition and expectation of residents in certain eventholding destination play a significant role to the success of this mega-event. This research analyzed the expectation of Shangehai residents, as well as the interdependent relationship between residents' expectation and 2010 Shanghai EXPO focusing on 2010 Shanghai EXPO. This study revealed that factor analysis selected 5 tourism expectation factors (infrastructural& environmentalfactor;positive attitude;social phenomenal;economic and price & real estate.Among Shanghai residents' demographic characteristics, except gender, the otherdemographic variables like age,educationallevel, marital level and profession all have obvious differences with the 5expectation factors.multi-regression analysis also revealed that Shanghai residents' expectation has apositive correlation with the active participating attitudes.Inthe end the insufficiency of this study is put forwardand recommendations on the futurestudyare alsogiven.

ZHANG Yun-yao

2010-09-01

118

Mega cisterna magna: a constant variation of the cerebellomedullary cistern associated with cerebral atrophy.  

Science.gov (United States)

Data relating to 31 cases of mega cisterna magna studied by computed tomography are presented. The incidence and the relation of this condition to cerebral atrophy are examined. Mega cisterna magna has a constant incidence in routine CT material and is closely associated with cerebral atrophy. PMID:3748263

Kars, Z; Kiliç, K; Ozgen, T; Bertan, V; Erbengi, A

1986-07-01

119

[A high sensitivity search for MU Gamma: The Mega experiment at LAMPF  

International Nuclear Information System (INIS)

This report describes the work done at Valparaiso University on LAMPF experiment E764, to conclude the neutrino flux calculations, and work done at Valparaiso University and at LANL on LAMPF E969, the MEGA experiment, specifically on the positron arm of the MEGA spectrometer

120

CONSTRUCTION OF PLASMIDS FOR USE IN RISK ASSESSMENT RESEARCH  

Science.gov (United States)

The report describes a series of selftransmissible and nonselftransmissible (cloning vector) plasmids constructed to compare results from different laboratory tests and plasmid systems. Plasmids were designed to overcome problems of reproducibility, confusion due to use of differ...

121

Development of sewage system for mega-city Karachi  

International Nuclear Information System (INIS)

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)

122

MegaPipe astrometry for the New Horizons spacecraft  

Science.gov (United States)

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.

Gwyn, S. D. J.

2014-04-01

123

PLASMIDS FROM ANAEROCELLUM THERMOPHILUM AND USES THEREOF  

DEFF Research Database (Denmark)

The present invention concerns the isolation of plasmids from extremely thermophilic anaerobic microorganisms and their use in genetic transformation of thermophilic and mesophilic microorganisms. More particular the invention concerns the use of thermostable plasmid vectors as tools for creating shuttle vectors for genetic transformation of extremely thermophilic anaerobic microorganisms.

Ahring, Birgitte Kiær Technical University of Denmark,

124

Reporter Plasmid to Identify Cancer Stem Cells  

Science.gov (United States)

The NCI lentiviral plasmid can identify the putative cancer stem cell population through the expression of fluorescent or luminescent proteins and has the potential to advance new therapies. The key feature of the plasmid is a reporter system that only detects cells expressing the core stem cell transcription factors Sox2 and Oct4.

125

Characterization of large linear plasmids in mycobacteria.  

OpenAIRE

Linear plasmids were found in Mycobacterium xenopi, M. branderi, and M. celatum. These elements represented a wide size range (from 20 to 320 kb), had Streptomyces-like terminal structures, and defined five hybridization groups. Cross-hybridization and common restriction fragment length polymorphism patterns of plasmids from the different species suggest either genetic exchange or a common ancestry of the species.

Picardeau, M.; Vincent, V.

1997-01-01

126

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

International Nuclear Information System (INIS)

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)

127

Residency training program: Perceptions of residents  

Directory of Open Access Journals (Sweden)

Full Text Available Background: There is a phobia among doctors for the residency training program, since the establishment of the program over 30 years ago. The reason for establishing the program was mainly to provide the much-needed specialists in medicine. Objectives: To ascertain the perception of the residency training program among residents. Materials and Methods: Structured questionnaires were administered to residents at 3 training institutions in Nigeria. Results: One hundred nineteen (85.5% questionnaires were returned out of 140. The ages of respondents ranged from 27 to 42 years, the median age being 30 years. There were 110 males and 9 females. One hundred six (89.1% were junior residents. Ninety (75.6% were sponsored by the training institutions. Seventy-four (62.25% felt their consultants were contributing just 50% or less to their training. Sixty-two (52.2% of the respondents had attended a revision course, conference or seminar within the last 6 months. Majority of the residents would want better remuneration, up-front payment of examination and revision fees, more teaching by the consultants and less emphasis on the provision of services as ways of improving the program. Conclusion: Majority of the residents are sponsored by the training institutions.

Yusufu L. M. D

2010-06-01

128

Conjugative transfer of the naturally occurring plasmids of Acetobacter xylinum by IncP-plasmid-mediated mobilization.  

OpenAIRE

Broad-host-range plasmids and cloning vectors were conjugatively transferred to Acetobacter xylinum. One of the plasmids, RP4::Mu cts61, was used for the insertion of Tn1 into the 16-, 44-, and 64-kilobase-pair plasmids of A. xylinum. The Tn1-labeled plasmids could be mobilized by a helper plasmid. Many of the Tn1 insertions affected the copy number of the plasmids.

Valla, S.; Coucheron, D. H.; Kjosbakken, J.

1986-01-01

129

Conjugative transfer of the naturally occurring plasmids of Acetobacter xylinum by IncP-plasmid-mediated mobilization.  

Science.gov (United States)

Broad-host-range plasmids and cloning vectors were conjugatively transferred to Acetobacter xylinum. One of the plasmids, RP4::Mu cts61, was used for the insertion of Tn1 into the 16-, 44-, and 64-kilobase-pair plasmids of A. xylinum. The Tn1-labeled plasmids could be mobilized by a helper plasmid. Many of the Tn1 insertions affected the copy number of the plasmids. PMID:3001030

Valla, S; Coucheron, D H; Kjosbakken, J

1986-01-01

130

SiO and CH3OH mega-masers in NGC 1068  

Science.gov (United States)

Maser is an acronym for microwave amplification by stimulated emission of radiation; in astronomy mega-masers are masers in galaxies that are ?106 times more luminous than typical galactic maser sources. Observational studies of mega-masers can help us to understand their origins and characteristics. More importantly, mega-masers can be used as diagnostic tracers to probe the physical properties of their parent galaxies. Since the late 1970s, only three types of molecules have been found to form mega-masers: H2O, OH and H2CO. Here we report the detection of both SiO and CH3OH mega-masers near the centre of Seyfert 2 galaxy NGC 1068 at millimetre wavelengths, obtained using the IRAM 30-m telescope. We argue that the SiO mega-maser originated from the nuclear disk and the CH3OH mega-maser originated from shock fronts. High-resolution observations in the future will enable us to investigate AGN feedback and determine the masses of central supermassive black holes in such galaxies.

Wang, Junzhi; Zhang, Jiangshui; Gao, Yu; Zhang, Zhi-Yu; Li, Di; Fang, Min; Shi, Yong

2014-11-01

131

Does the Earth show up an impending mega-earthquake?  

CERN Document Server

In line of the intermediate-term monitoring of seismic activity aimed at prediction of the world largest earthquakes the seismic dynamics of the Earth's lithosphere is analysed as a single whole, which is the ultimate scale of the complex hierarchical non-linear system. The present study demonstrates that the lithosphere does behave, at least in intermediate-term scale, as non-linear dynamic system that reveals classical symptoms of instability at the approach of catastrophe, i.e., mega-earthquake. These are: (i) transformation of magnitude distribution, (ii) spatial redistribution of seismic activity, (iii) rise and acceleration of activity, (iv) change of dependencies across magnitudes of different types, and other patterns of collective behaviour. The observed global scale seismic behaviour implies the state of criticality of the Earth lithosphere in the last decade.

Romashkova, L L; Kossobokov, Vladimir G.; Romashkova, Leontina L.

2007-01-01

132

HST imaging of MEGA Microlensing Candidates in M31  

Energy Technology Data Exchange (ETDEWEB)

We investigate HST/ACS and WFPC2 images at the positions of five candidate microlensing events from a large survey of variability in M31 (MEGA). Three closely match unresolved sources, and two produce only flux upper limits. All are confined to regions of the color-magnitude diagram where stellar variability is unlikely to be easily confused with microlensing. Red variable stars cannot explain these events (although background supernova are possible for two). If these lenses arise in M31's halo, they are due to masses 0.08 < m/M{sub {circle_dot}} < 0.85 (95% certainty, for a {delta}-function mass distribution), brown dwarfs for disk/disk, and stellar masses for disk/bulge ''self-lensing''.

Cseresnjes, Patrick; Crotts, Arlin P.S.; de Jong, Jelte T.A.; Bergier, Alex; Baltz, Edward A.; Gyuk, Geza; Kuijken, Konrad; Widrow, Lawrence M.; /Columbia U., Astron.; s U., Kingston

2005-07-14

133

Producing mega-pixel CMB maps from differential radiometer data  

CERN Document Server

A major goal of cosmology is to obtain sensitive, high resolution maps of the Cosmic Microwave Background (CMB) anisotropy. Such maps, as would be produced by the recently proposed Microwave Anisotropy Probe (MAP), will contain a wealth of primary information about conditions in the early universe. To mitigate systematic effects when observing the microwave background, it is desirable for the raw data to be collected in differential form: as a set of temperature differences between points in the sky. However, the production of large (mega-pixel) maps from a set of temperature differences is a potentially severe computational challenge. We present a new technique for producing maps from differential radiometer data that has a computational cost that grows in the slowest possible way with increasing angular resolution and number of map pixels. The required central processor (CPU) time is proportional to the number of differential data points and the required random access memory (RAM) is proportional to the num...

Wright, E L; Bennett, C L; Wright, Edward L; Hinshaw, Gary; Bennett, Charles L

1995-01-01

134

Equilibrium and stability of the mega ampere spherical tokamak  

International Nuclear Information System (INIS)

Full text: In this work, the equilibrium and stability of several high performance Mega-Ampere Spherical Tokamak (MAST) plasmas is investigated. Kinetic equilibrium reconstructions, in which the thermal pressure profile is fitted to thermal data, suggest normalized beta ?n up to 4.95 and bootstrap fractions up to 30%. Full-orbit simulations suggest that up to 25% of the total stored energy is in the fast-ion population: lifting ?n to 5.56. Using these reconstructions, ideal MHD stability thresholds of n=1,2 and ( displacements are examined, and it is concluded that passive stabilization may soon be required to access higher performance. Copyright (2005) Australian Institute of Physics

135

Isolation of Z-DNA-containing plasmids.  

OpenAIRE

A purified, monoclonal antibody, specific for the left-handed Z-form of poly(dG-dC), was coupled covalently to Sephacryl S-1000 beads. Such an antibody column provides a convenient method to isolate and purify those plasmid DNAs that contain Z-DNA from a large excess of other DNAs, RNA, etc. From a library of Escherichia coli DNA, cloned into the vector plasmid pUC-8, several recombinant plasmids were isolated, which bind to this antibody. Thus, E. coli contains sequences, which in "natural" ...

Thomae, R.; Beck, S.; Pohl, F. M.

1983-01-01

136

Plasmid-encoded trimethoprim resistance in staphylococci.  

OpenAIRE

High-level (greater than 1,000 micrograms/ml) resistance to the antimicrobial agent trimethoprim was found in 17 of 101 (17%) coagulase-negative staphylococci and 5 of 51 (10%) Staphylococcus aureus from a number of different hospitals in the United States. Resistance was plasmid encoded and could be transferred by conjugation in 4 of the 17 (24%) Tpr coagulase-negative staphylococci and 3 of the 5 (60%) Tpr S. aureus. A 1.2-kilobase segment of plasmid DNA from one of the plasmids (pG01) was ...

Archer, G. L.; Coughter, J. P.; Johnston, J. L.

1986-01-01

137

Transformation of Bacillus polymyxa with plasmid DNA.  

OpenAIRE

A plasmid transformation system was developed for Bacillus polymyxa ATCC 12321 and derivatives of this strain. The method utilizes a penicillin-treated-cell technique to facilitate uptake of the plasmid DNA. Low-frequency transformation (10(-6) per recipient cell) of plasmids pC194, pBD64, and pBC16 was accomplished with this method. Selection for the transformants was accomplished on both hypertonic and nonhypertonic selective media, with the highest rates of recovery occurring on a peptone-...

Mallonee, D. H.; Speckman, R. A.

1989-01-01

138

PcrA function in plasmid replication  

OpenAIRE

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...

Chisty, L. T.

2014-01-01

139

Plasmid and transposon transfer to Thiobacillus ferrooxidans.  

OpenAIRE

The broad-host-range IncP plasmids RP4, R68.45, RP1::Tn501, and pUB307 were transferred to acidophilic, obligately chemolithotrophic Thiobacillus ferrooxidans from Escherichia coli by conjugation. A genetic marker of kanamycin resistance was expressed in T. ferrooxidans. Plasmid RP4 was transferred back to E. coli from T. ferrooxidans. The broad-host-range IncQ vector pJRD215 was mobilized to T. ferrooxidans with the aid of plasmid RP4 integrated in the chromosome of E. coli SM10. pJRD215 was...

Peng, J. B.; Yan, W. M.; Bao, X. Z.

1994-01-01

140

Isolation and characterization of antibiotic resistance plasmids from thermophilic bacilli and construction of deletion plasmids.  

OpenAIRE

Ten plasmids were isolated as covalently closed circular deoxyribonucleic acid from antibiotic-resistant thermophilic bacteria. Of the 10 plasmids tested, 2 could transform Bacillus subtilis, yielding resistance to specific antibiotics. Plasmid pTB20 (2.8 X 10(6) daltons, approximately 24 copies per chromosome) specifies resistance to tetracycline (Tcr), whereas pTB19 (17.2 X 10(6) daltons, approximately 1 copy per chromosome) renders the host resistant to both kanamycin and tetracycline (KMr...

Imanaka, T.; Fujii, M.; Aiba, S.

1981-01-01

141

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

International Nuclear Information System (INIS)

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

142

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

Energy Technology Data Exchange (ETDEWEB)

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.

Perez, R. V., E-mail: rvale006@fiu.edu; Boeglin, W. U.; Angulo, A.; Avila, P.; Leon, O.; Lopez, C. [Department of Physics, Florida International University, 11200 SW 8 ST, CP204, Miami, Florida 33199 (United States); Darrow, D. S. [Princeton Plasma Physics Laboratory, James Forrestal Campus, P.O. Box 451, Princeton, New Jersey 08543 (United States); Cecconello, M.; Klimek, I. [Department of Physics and Astronomy, Uppsala University, Uppsala SE-751 20 (Sweden); Allan, S. Y.; Akers, R. J.; Keeling, D. L.; McClements, K. G.; Scannell, R.; Conway, N. J. [CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Turnyanskiy, M. [ITER Physics Department, EFDA CSU Garching, Boltzmannstrasse 2, D-85748, Garching (Germany); Jones, O. M. [CCFE, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Michael, C. A. [Australian National University, Canberra ACT 0200 (Australia)

2014-11-15

143

Expression plasmids for use in Candida glabrata.  

Science.gov (United States)

We describe a series of CEN/ARS episomal plasmids containing different Candida glabrata promoters, allowing for a range of constitutive or regulated expression of proteins in C. glabrata. The set of promoters includes three constitutive promoters (EGD2pr, HHT2pr, PDC1pr), two macrophage/phagocytosis-induced promoters (ACO2pr, LYS21pr), and one nutritionally regulated promoter (MET3pr). Each promoter was cloned into two plasmid backbones that differ in their selectable marker, URA3, or the dominant-selectable NAT1 gene, which confers resistance to the drug nourseothricin. Expression from the 12 resulting plasmids was assessed using GFP as a reporter and flow cytometry or quantitative reverse-transcription polymerase chain reaction to assess expression levels. Together this set of plasmids expands the toolkit of expression vectors available for use with C. glabrata. PMID:23934995

Zordan, Rebecca E; Ren, Yuxia; Pan, Shih-Jung; Rotondo, Giuseppe; De Las Peñas, Alejandro; Iluore, Joseph; Cormack, Brendan P

2013-10-01

144

Clostridium perfringens type A-E toxin plasmids.  

Science.gov (United States)

Clostridium perfringens relies upon plasmid-encoded toxin genes to cause intestinal infections. These toxin genes are associated with insertion sequences that may facilitate their mobilization and transfer, giving rise to new toxin plasmids with common backbones. Most toxin plasmids carry a transfer of clostridial plasmids locus mediating conjugation, which likely explains the presence of similar toxin plasmids in otherwise unrelated C. perfringens strains. The association of many toxin genes with insertion sequences and conjugative plasmids provides virulence flexibility when causing intestinal infections. However, incompatibility issues apparently limit the number of toxin plasmids maintained by a single cell. PMID:25283728

Freedman, John C; Theoret, James R; Wisniewski, Jessica A; Uzal, Francisco A; Rood, Julian I; McClane, Bruce A

2014-10-01

145

Plasmid and chromosome segregation in prokaryotes  

DEFF Research Database (Denmark)

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

MØller-Jensen, Jakob; Bugge Jensen, Rasmus

2000-01-01

146

Plasmid-mediated mineralization of 4-chlorobiphenyl.  

OpenAIRE

Strains of Alcaligenes and Acinetobacter spp. were isolated from a mixed culture already proven to be proficient at complete mineralization of monohalogenated biphenyls. These strains were shown to harbor a 35 X 10(6)-dalton plasmid mediating a complete pathway for 4-chlorobiphenyl (4CB) oxidation. Subsequent plasmid curing of these bacteria resulted in the abolishment of the 4CB mineralization phenotype and loss of even early 4CB metabolism by Acinetobacter spp. Reestablishment of the Alcali...

Shields, M. S.; Hooper, S. W.; Sayler, G. S.

1985-01-01

147

Plasmid-mediated mineralization of 4-chlorobiphenyl  

International Nuclear Information System (INIS)

Strains of Alcaligenes and Acinetobacter spp. were isolated from a mixed culture already proven to be proficient at complete mineralization of monohalogenated biphenyls. These strains were shown to harbor a 35 x 10(6)-dalton plasmid mediating a complete pathway for 4-chlorobiphenyl (4CB) oxidation. Subsequent plasmid curing of these bacteria resulted in the abolishment of the 4CB mineralization phenotype and loss of even early 4CB metabolism by Acinetobacter spp. Reestablishment of the Alcaligenes plasmid, denoted pSS50, in the cured Acinetobacter spp. via filter surface mating resulted in the restoration of 4CB mineralization abilities. 4CB mineralization, however, proved to be an unstable characteristic in some subcultured strains. Such loss was not found to coincide with any detectable alteration in plasmid size. Cultures capable of complete mineralization, as well as those limited to partial metabolism of 4CB, produced 4-chlorobenzoate as a metabolite. Demonstration of mineralization of a purified 14C-labeled chlorobenzoate showed it to be a true intermediate in 4CB mineralization. Unlike the mineralization capability, the ability to produce a metabolite has proven to be stable on subculture. These results indicate the occurrence of a novel plasmid, or evolved catabolic plasmid, that mediates the complete mineralization of 4CB

148

Engineering large functional plasmids for biosafety.  

Science.gov (United States)

Large bacterial plasmid constructs (generally 25-100 kb, but can be greater), such as those engineered with DNA encoding specific functions such as protein secretion or specialized metabolism, can carry antibiotic resistance genes and/or conjugation systems that typically must be removed before use in medical or environmental settings due to biosafety concerns. However, a convenient in vivo recombineering approach for intact large plasmids to sequentially remove multiple different genes using non-antibiotic selection methods is not described in the literature to our knowledge. We developed strategies and reagents for convenient removal of antibiotic resistance markers and conjugation genes while retaining non-antibiotic-based plasmid selection to increase practical utility of large engineered plasmids. This approach utilizes targeted lambda Red recombination of PCR products encoding the trpE and asd genes and as well as FLP/FRT-mediated marker removal. This is particularly important given that use of restriction enzymes with plasmids of this size is extremely problematic and often not feasible. This report provides the first example of the trpE gene/tryptophan prototrophy being used for recombineering selection. We applied this strategy to the plasmids R995+SPI-1 and R995+SPI-2 which encode cloned type III secretion systems to allow protein secretion and substrate delivery to eukaryotic cells. The resulting constructs are functional, stably maintained under conditions where the original constructs are unstable, completely defective for conjugative transfer, and transferred via electroporation. PMID:24055203

Cangelosi, Chris; Shank, Caroline; Santiago, Clayton; Wilson, James W

2013-11-01

149

Compositional discordance between prokaryotic plasmids and host chromosomes  

OpenAIRE

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 e...

Hc, Kampen Antoine; Cm, Luyf Angela; Bart Aldert; Wj, Passel Mark; van der Ende Arie

2006-01-01

150

Penicillin and tetracycline resistance plasmids in Staphylococcus epidermidis.  

OpenAIRE

The genetic nature of penicillin (Pc) and tetracycline (Tc) resistance plasmids in Staphylococcus epidermidis were studied and compared with those in S. aureus. Of 10 S. epidermidis strains transduced for penicillin resistance, we could isolate Pc plasmids from only 3. One of these plasmids also encoded for cadmium resistance and another encoded for resistance to ethidium bromide, traits also associated with S. aureus Pc plasmids. Endonuclease fingerprinting of the Pc plasmids from the two sp...

Totten, P. A.; Vidal, L.; Baldwin, J. N.

1981-01-01

151

Plasmid DNA from the acetotrophic methanogen Methanosarcina acetivorans.  

OpenAIRE

Nine acetotrophic and three methylotrophic strains of methane-producing bacteria were screened for the presence of plasmid DNA. Plasmids were detected in three marine isolates, including Methanosarcina acetivorans. All three plasmids appeared to be similar based on size and restriction site analyses. The plasmid from M. acetivorans, designated pC2A, was approximately 5.1 kilobase pairs in size and was estimated to be present in a low copy number of six plasmids per genome. Multimers were also...

Sowers, K. R.; Gunsalus, R. P.

1988-01-01

152

[Antibiotic resistance plasmids in various strains of Staphylococcus aureus].  

Science.gov (United States)

Plasmids with the molecular weights of 1.6 to 21.0 MD were detected in Staphylococcus aureus. The plasmids determined resistance to benzylpenicillin, ampicillin, streptomycin, erythromycin, tetracycline, chloramphenicol, arsenate and arsenite. Strain p16 of Staphylococcus aureus contained plasmid pL16 with the molecular weight of 18.0 MD determining resistance to erythromycin, streptomycin, benzylpenicillin and ampicillin. The plasmid has two replication sites and is likely a natural recombinant of two plasmids. PMID:8166563

Gabisoniia, T G; Chanishvili, T G; Makaridze, M R; Chikovani, L A; Adamiia, R Sh; Galushka, F P; Karataev, G I

1993-06-01

153

MEGA: a biologist-centric software for evolutionary analysis of DNA and protein sequences.  

Science.gov (United States)

The Molecular Evolutionary Genetics Analysis (MEGA) software is a desktop application designed for comparative analysis of homologous gene sequences either from multigene families or from different species with a special emphasis on inferring evolutionary relationships and patterns of DNA and protein evolution. In addition to the tools for statistical analysis of data, MEGA provides many convenient facilities for the assembly of sequence data sets from files or web-based repositories, and it includes tools for visual presentation of the results obtained in the form of interactive phylogenetic trees and evolutionary distance matrices. Here we discuss the motivation, design principles and priorities that have shaped the development of MEGA. We also discuss how MEGA might evolve in the future to assist researchers in their growing need to analyze large data set using new computational methods. PMID:18417537

Kumar, Sudhir; Nei, Masatoshi; Dudley, Joel; Tamura, Koichiro

2008-07-01

154

Sustainability as Global Norm: The Greening of Mega-Events in China  

OpenAIRE

This volume explores sports mega-events, their social, political, and cultural characters, the value systems that they inscribe and draw on, the claims they make on us and the claims the organisers make for them, the spatial and ethical relationships they create, and the responses of civil societies to them. Our premise is that sports mega-events are not simply sporting or cultural phenomena. They are also political and economic events, characterised by the generation and projection of symbol...

Mol, A. P. J.; Zhang, L.

2011-01-01

155

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

OpenAIRE

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 ...

Sandelin, Christian; Budajev, Evgenij

2013-01-01

156

Mega events, tourism and local development: the case of Torino 2006  

OpenAIRE

This paper examines the impact of mega-events such as Olympic Games on tourism development in host territories. In the first part, we adopt a territorialization approach to understand the relationship between the event and the host region.A mega-event is conceived as a great chance to generate new territory as it produces both tangible and intangible legacies that remain after the event ends: renewal of facilities for hospitality and accommodation, better infrastructures, better training for ...

Dansero, Egidio; Puttilli, Matteo Girolamo

2010-01-01

157

MEGA: A biologist-centric software for evolutionary analysis of DNA and protein sequences  

OpenAIRE

The Molecular Evolutionary Genetics Analysis (MEGA) software is a desktop application designed for comparative analysis of homologous gene sequences either from multigene families or from different species with a special emphasis on inferring evolutionary relationships and patterns of DNA and protein evolution. In addition to the tools for statistical analysis of data, MEGA provides many convenient facilities for the assembly of sequence data sets from files or web-based repositories, and it ...

Kumar, Sudhir; Nei, Masatoshi; Dudley, Joel; Tamura, Koichiro

2008-01-01

158

High-level plasmid-mediated gentamicin resistance and pheromone response of plasmids present in clinical isolates of Enterococcus faecalis.  

OpenAIRE

Eleven pheromone-responding plasmids encoding erythromycin or gentamicin resistance were isolated from multiresistant clinical Enterococcus faecalis isolates. The plasmids were classified into six types with respect to their pheromone responses. The three erythromycin resistance plasmids responded to different pheromones. Of the eight gentamicin resistance plasmids, four plasmids responded to same pheromone. Southern hybridization studies showed that the genes involved in regulation of the ph...

Shiojima, M.; Tomita, H.; Tanimoto, K.; Fujimoto, S.; Ike, Y.

1997-01-01

159

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

OpenAIRE

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...

Tinge, S. A.; Curtiss, R.

1990-01-01

160

Bacteriophage selection against a plasmid-encoded sex apparatus leads to the loss of antibiotic-resistance plasmids  

OpenAIRE

Antibiotic-resistance genes are often carried by conjugative plasmids, which spread within and between bacterial species. It has long been recognized that some viruses of bacteria (bacteriophage; phage) have evolved to infect and kill plasmid-harbouring cells. This raises a question: can phages cause the loss of plasmid-associated antibiotic resistance by selecting for plasmid-free bacteria, or can bacteria or plasmids evolve resistance to phages in other ways? Here, we show that multiple ant...

Jalasvuori, Matti; Friman, Ville-petri; Nieminen, Anne; Bamford, Jaana K. H.; Buckling, Angus

2011-01-01

161

The Kalimantan Border Oil Palm Mega-project  

International Nuclear Information System (INIS)

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 pad 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 buyers, investors and government bodies outside Indonesia about the undiminished threats to the tropical rainforests and indigenous peoples related to Indonesia's oil palm expansion plans and the government's overall development agenda for Kalimantan

162

The Kalimantan Border Oil Palm Mega-project  

Energy Technology Data Exchange (ETDEWEB)

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 buyers, investors and government bodies outside Indonesia about the undiminished threats to the tropical rainforests and indigenous peoples related to Indonesia's oil palm expansion plans and the government's overall development agenda for Kalimantan.

Wakker, E. [AIDEnvironment, Amsterdam (Netherlands)

2006-04-15

163

Genetic characterization of the conjugative DNA processing system of enterococcal plasmid pCF10.  

Science.gov (United States)

Conjugation is a major contributor to lateral gene transfer in bacteria, and pheromone-inducible conjugation systems in Enterococcus faecalis play an important role in the dissemination of antibiotic resistance and virulence in enterococci and related bacteria. We have genetically dissected the determinants of DNA processing of the enterococcal conjugative plasmid pCF10. Insertional inactivation of a predicted relaxase gene pcfG, via insertion of a splicing-deficient group II intron, severely reduced pCF10 transfer. Restoration of intron splicing ability by genetic complementation restored conjugation. The pCF10 origin of transfer (oriT) was localized to a 40-nucleotide sequence within a non-coding region with sequence similarity to origins of transfer of several other plasmids in gram positive bacteria. Deletion of the oriT reduced pCF10 transfer by more than five orders of magnitude without affecting pCF10-dependent mobilization of co-resident oriT-containing plasmids. Although the host range for pCF10 replication is limited to enterococci, we found that the pCF10 conjugation system promotes mobilization of oriT-containing plasmids to multiple bacterial genera. Therefore, this transfer system may have applications for gene delivery to a variety of poorly-transformed bacteria. PMID:16774784

Staddon, Jack H; Bryan, Edward M; Manias, Dawn A; Chen, Yuqing; Dunny, Gary M

2006-09-01

164

FCC resid processing  

International Nuclear Information System (INIS)

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

165

Photoreactivation of ultraviolet-irradiated, plasmid-bearing and plasmid-free strains of bacillus anthracis  

Energy Technology Data Exchange (ETDEWEB)

The effects of toxin- and capsule-encoding plasmids on the kinetics of UV inactivation of various strains of Bacillus anthracis were investigated. Plasmids pX01 and pX02 had no effect on bacterial UV sensitivity or photoreactivation. Vegetative cells were capable of photoreactivation, but photo-induced repair of UV damage absent in B. anthracis Sterne spores.

Knudson, G.B.

1985-12-19

166

Plasmid Flux in Escherichia coli ST131 Sublineages, Analyzed by Plasmid Constellation Network (PLACNET), a New Method for Plasmid Reconstruction from Whole Genome Sequences  

OpenAIRE

Bacterial whole genome sequence (WGS) methods are rapidly overtaking classical sequence analysis. Many bacterial sequencing projects focus on mobilome changes, since macroevolutionary events, such as the acquisition or loss of mobile genetic elements, mainly plasmids, play essential roles in adaptive evolution. Existing WGS analysis protocols do not assort contigs between plasmids and the main chromosome, thus hampering full analysis of plasmid sequences. We developed a method (called plasmid...

Lanza, Val F.; Toro, Mari?a; Garcilla?n-barcia, M. Pilar; Mora, Azucena; Blanco, Jorge; Coque, Teresa M.; La Cruz, Fernando

2014-01-01

167

Beam shaping in the MegaJoule laser project  

Science.gov (United States)

The LMJ (Laser MegaJoule) is dedicated to inertial confinement fusion. To perform this type of experiment, 160 square beams are frequency converted and focused onto a target filled with a deuterium tritium mixture. We propose to review how these beams are shaped along their propagation through the LMJ. Going upstream from the target to the laser source, specific optics has been designed to meet the beam shaping requirement. A focusing grating and a pseudorandom phase plate concentrate the energy onto the target. A deformable mirror controls and compensates the spatial phase defect occurring during the propagation through the main slab amplifiers. A liquid crystal cell shapes the beam in order to compensate the gain profile of the main amplifiers. It also protects the growth of damages that take place in the final optics of the chain. At last, a phase mirror generates a square flat top mode from a gaussian beam within a regenerative amplifier. All these optical components have one common principle: they control the phase of the spatial laser field.

Luce, Jacques

2011-10-01

168

The CFHT/MegaCam Stripe-82 Survey  

Science.gov (United States)

The CFTH/MegaCam Stripe-82 Survey (CS82) is a joint Canada-France-Brazil project covering ˜ 170 sq. deg. in the SDSS Stripe-82 area down to magnitude 24.1 in the optical i-band with a mean 0.6" seeing (PIs: J.-P. Kneib, A. Leauthaud, M. Makler, L. Van Waerbeke). Its main focus is the study of weak and strong gravitational lensing, with additional applications in other fields such as galaxy evolution and galaxy cluster science. Furthermore, the multitude of existing and future projects in Stripe-82, covering from the radio to the UV and including a large set of spectroscopic data, offers the possibility of exploring applications in many fields of astronomy, thereby enhancing the scientific value of the survey. In this Short Talk, we will give an overview of the main published and ongoing CS82 scientific projects. They include the measurement of the largest contiguous lensing convergence map to date and its peak statistics, providing direct information on the large scale dark matter distribution; the first CMB-lensing × shear cross-correlation measurement, probing the dark matter distribution at redshifts of order 1; galaxy-galaxy lensing measurements around SDSS-III/BOSS galaxies, constraining halo occupation distribution (HOD) models and obtaining complementary mass measurements in combination with BOSS spectroscopic data; the discovery of several new gravitational arc systems and more.

Moraes, B.; Kneib, J.-P.; Leauthaud, A.; Makler, M.; Van Waerbeke, L.; Bundy, K.; Erben, T.; Heymans, C.; Hildebrandt, H.; Miller, L.; Shan, H. Y.; Woods, D.; Charbonnier, A.; Pereira, M. E.

2014-10-01

169

System modelling and identification of Mega-Amp Spherical Tokamak  

Energy Technology Data Exchange (ETDEWEB)

A dynamic system response model for plasma in Mega-Amp Spherical Tokamak (MAST) has been developed using RZIP. This is a linearized tokamak model. It assumes a constant plasma current distribution and axisymmetry. The plasma and conducting structures are approximated by discrete toroidal current filaments. RZIP generates a state-space model of the system behaviour, with PF coil voltages as inputs and various predicted diagnostic measurements as outputs. A separate SIMULINK model has been developed to represent the MAST plant, power supplies and analogue feedback controller. The RZIP and SIMULINK models were combined to produce a complete system model. This combined model was used to simulate test shots under both vacuum and plasma conditions. The two sets of traces cohere reasonably well, with some difference in attenuation levels. System identification experiments were carried out on the PF coils, with particular attention paid to the vertical field coils, under vacuum conditions. The frequency response behaviour was found using an excitation signal comprising a number of sinusoids. The RZIP model was verified by comparing its predicted response with experimental data.

Qin, J. E-mail: j.qin@ic.ac.uk; Limebeer, D.; McArdle, G.J.; Wainwright, J

2001-10-01

170

Plasmid and chromosome partitioning: surprises from phylogeny  

DEFF Research Database (Denmark)

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 origin regions to specific subcellular sites (i.e. the poles or quarter-cell positions). Two types of partitioning ATPases are known: the Walker-type ATPases encoded by the par/sop gene family (type I partitioning loci) and the actin-like ATPase encoded by the par locus of plasmid R1 (type II partitioning locus). A phylogenetic analysis of the large family of Walker type of partitioning ATPases yielded a surprising pattern: most of the plasmid-encoded ATPases clustered into distinct subgroups. Surprisingly, however, the par loci encoding these distinct subgroups have different genetic organizations and thus divide the type I loci into types Ia and Ib. A second surprise was that almost all chromosome-encoded ATPases, including members from both Gram-negative and Gram-positive Bacteria and Archaea, clustered into one distinct subgroup. The phylogenetic tree is consistent with lateral gene transfer between Bacteria and Archaea. Using database mining with the ParM ATPase of plasmid R1, we identified a new par gene family from enteric bacteria. These type II loci, which encode ATPases of the actin type, have a genetic organization similar to that of type Ib loci. Udgivelsesdato: Aug

Gerdes, Kenn; MØller-Jensen, Jakob

2000-01-01

171

“Festivalisation” of Urban Governance in South African Cities: Framing the Urban Social Sustainability of Mega-Event Driven Development from Below  

Directory of Open Access Journals (Sweden)

Full Text Available This article is based on field research in two South African host cities of the Men’s Football World Cup 2010 (eThekwini and Johannesburg. The discussed work is part of the research project “Festivalisation” of Urban Governance: The Production of Socio-Spatial Control in the Context of the FIFA World Cup 2010 in South Africa. In the context of mega-events, impacts and changes on urban development can vary on a spectrum of festivalisation between opposing poles, either “driven by the event”, or on the other hand where existing configurations of actors and established policies are “driving the event”. By drawing on a theoretical framework which is inspired by an analytical understanding of urban governance, our assumptions are that (a different configurations of governance promote different ways of handling the challenges associated to the hosting and (b that different types of “festivalisation” have different consequences and effects for the lived realities of the residents at a local level. The latter is an arena in which urban governance policies are translated, adapted, renegotiated or rejected. We argue that the bringing together of both spheres (local and metropolitan provides a profound understanding of the process of mega-event implementation and its relation to urban social sustainability.

Matthias Fleischer

2013-12-01

172

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

OpenAIRE

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 tha...

Lupi, M.; Miller, S. A.

2013-01-01

173

Changes in medicine: residency  

Directory of Open Access Journals (Sweden)

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 …

Robbins RA

2011-07-01

174

BioShuttle-mediated Plasmid Transfer  

Directory of Open Access Journals (Sweden)

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.

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

2007-01-01

175

Mechanisms for chromosome and plasmid segregation.  

Science.gov (United States)

The fundamental problems in duplicating and transmitting genetic information posed by the geometric and topological features of DNA, combined with its large size, are qualitatively similar for prokaryotic and eukaryotic chromosomes. The evolutionary solutions to these problems reveal common themes. However, depending on differences in their organization, ploidy, and copy number, chromosomes and plasmids display distinct segregation strategies as well. In bacteria, chromosome duplication, likely mediated by a stationary replication factory, is accompanied by rapid, directed migration of the daughter duplexes with assistance from DNA-compacting and perhaps translocating proteins. The segregation of unit-copy or low-copy bacterial plasmids is also regulated spatially and temporally by their respective partitioning systems. Eukaryotic chromosomes utilize variations of a basic pairing and unpairing mechanism for faithful segregation during mitosis and meiosis. Rather surprisingly, the yeast plasmid 2-micron circle also resorts to a similar scheme for equal partitioning during mitosis. PMID:16756491

Ghosh, Santanu Kumar; Hajra, Sujata; Paek, Andrew; Jayaram, Makkuni

2006-01-01

176

Electrotransfer of Plasmid Vector DNA into Muscle  

Science.gov (United States)

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.

Miyazaki, Satsuki; Miyazaki, Jun-Ichi

177

Plasmid Coded Halotolerance in Mangrove Soil Bacteria  

Directory of Open Access Journals (Sweden)

Full Text Available Increasing salinity in the soil and irrigation water is a global concern of paramount importance especially to Pakistan. Isolation was carried out from soil samples of Mangrove area near `REHRI`, two isolates CMG350 (Staphylococcus saprophyticus and CMG351 (Pseudomonas paucimobilis were selected for further studies. Character halotolerance in both the isolates was plasmid born, as cured derivatives lost the character. Maximum accumulation of Na+ i.e., 12.5% was observed by CMG351 whereas 9.8% was observed by CMG350. Halotolerance was found associated with proteins encoded by plasmids.

Nuzhat Ahmed

2003-01-01

178

Stress in Family Practice Residents  

OpenAIRE

Sources and levels of stress, as well as coping mechanisms, perceived by residents in both years of a two-year family practice residency program in Toronto are described. In addition, differences between first- and second-year residents, and between women and men residents, regardless of year, are examined. Results of the survey indicate that the levels of stress are relatively high throughout the two years of residency training. The three most stressful aspects of being a resident are time p...

Rudner, Howard L.

1986-01-01

179

The Challenge of Problem Residents  

OpenAIRE

Internal medicine residency training is demanding and residents can experience a wide variety of professional and personal difficulties. Residency programs everywhere have had and will continue to have problem residents. Training programs should be equipped to effectively identify and manage residents who experience problems. Previous articles that have been published on the topic of problem residents primarily addressed concerns such as impairment due to depression and substance abuse. The c...

Yao, David C.; Wright, Scott M.

2001-01-01

180

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

OpenAIRE

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...

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

1997-01-01

181

Bacillus subtilis (natto) plasmid pLS20 mediates interspecies plasmid transfer.  

OpenAIRE

The 55-kilobase plasmid, pLS20, of Bacillus subtilis (natto) 3335 promotes transfer of the tetracycline resistance plasmid pBC16 from B. subtilis (natto) to the Bacillus species B. anthracis, B. cereus, B. licheniformis, B. megaterium, B. pumilus, B. subtilis, and B. thuringiensis. Frequency of pBC16 transfer ranged from 2.3 x 10(-6) to 2.8 x 10(-3). Evidence for a plasmid-encoded conjugationlike mechanism of genetic exchange includes (i) pLS20+ strains, but not pLS20- strains, functioned as ...

Koehler, T. M.; Thorne, C. B.

1987-01-01

182

Transcription from efficient promoters can interfere with plasmid replication and diminish expression of plasmid specified genes.  

OpenAIRE

The copy number of plasmids containing the ColE1 replicon is affected by changes in the transcriptional activity within the plasmid if these changes lead to transcriptional readthrough into the replication region towards the promoter priming DNA replication. Such readthrough e.g., from the tet region in pBR322 not only causes overproduction of a peptide known to affect the copy number negatively but also appears to interfere negatively with the replication of the plasmid itself. The proper pl...

Stueber, D.; Bujard, H.

1982-01-01

183

Characterization of the nodulation plasmid encoded chemoreceptor gene mcpG from Rhizobium leguminosarum  

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Full Text Available Abstract Background In general, chemotaxis in Rhizobium has not been well characterized. Methyl accepting chemotaxis proteins are sensory proteins important in chemotaxis of numerous bacteria, but their involvement in Rhizobium chemotaxis is unclear and merits further investigation. Results A putative methyl accepting chemotaxis protein gene (mcpG of Rhizobium leguminosarum VF39SM was isolated and characterized. The gene was found to reside on the nodulation plasmid, pRleVF39d. The predicted mcpG ORF displayed motifs common to known methyl-accepting chemotaxis proteins, such as two transmembrane domains and high homology to the conserved methylation and signaling domains of well-characterized MCPs. Phenotypic analysis of mcpG mutants using swarm plates did not identify ligands for this putative receptor. Additionally, gene knockouts of mcpG did not affect a mutant strain's ability to compete for nodulation with the wild type. Notably, mcpG was found to be plasmid-encoded in all strains of R. leguminosarum and R. etli examined, though it was found on the nodulation plasmid only in a minority of strains. Conclusions Based on sequence homology R. leguminosarum mcpG gene codes for a methyl accepting chemotaxis protein. The gene is plasmid localized in numerous Rhizobium spp. Although localized to the sym plasmid of VF39SM mcpG does not appear to participate in early nodulation events. A ligand for McpG remains to be found. Apparent McpG orthologs appear in a diverse range of proteobacteria. Identification and characterization of mcpG adds to the family of mcp genes already identified in this organism.

Del Bel Kate L

2003-01-01

184

Mega-scale glacial lineations and drumlins: a morphological continuum?  

Science.gov (United States)

Mega-scale glacial lineations (MSGL) are highly elongate ridges that maintain a parallel conformity over length of 10s of km. Investigation of relict MSGL suggests that they form under fast flowing ice streams. This has now been verified by direct imaging of the bed of Rutford ice stream, West Antarctica. However, the mechanism(s) of MSGL formation is rather poorly understood, although some divergent theories and models have been suggested. Some of these theories have developed from concepts and models initially proposed to explain the formation of another glacial bedform, the drumlin. This would support the idea of a subglacial bedform continuum, i.e. that a distinction amongst related bedforms is artificial because each 'type' of landform gradually evolves into the other and they are the expression of the same fundamental process of formation. To date, very few (if any?) studies have attempted to systematically quantify the morphometric (size and shape) differences and similarities between drumlins and MSGL using a large database. In this paper, we present the result of an extensive analysis of drumlins and MSGL that are found within a single flow-set formed by the Dubawnt lake palaeo-ice stream on the central Canadian Shield. Thousands of MSGL and drumlins have been mapped there for analysis of bedform length, width, elongation, shape (planar asymmetry) and spatial distribution. Results are also compared to other published studies. Altogether, they strongly suggest that the morphometric difference between a 'drumlin' and 'MSGL' is subtle and that, for most variables, the frequency distribution of one landform population largely overlap with that of the other. This supports the idea that the same process might indeed be responsible for the formation of both.

Spagnolo, M.; Stokes, C. R.; Clark, C. D.; Dunstone, R. B.

2012-04-01

185

Quality Control of Mega Voltage Portal Imaging System  

International Nuclear Information System (INIS)

The Electronic Portal Imaging Device (EPID) is a system used to verify either the correct positioning of the patient during radiotherapy treatment or the linear accelerator beam parameters. The correct position of the patient corresponds to the position at which the patient was scanned at the CT simulator and according to which the therapy plan was made and optimized. Regarding this, besides the advanced treatment planning system and optimized treatment planning techniques, the day-to-day reproduction of simulated conditions is of great importance for the treatment outcome. Therefore, to verify the patient set-up portal imaging should be applied prior to the first treatment session and repeated according to treatment prescriptions during the treatment. In order to achieve full functionality and precision of the EPID, it must be included in radiotherapy Quality Control (QC) programme. The QC of the Mega Voltage portal imaging system was separated in two parts. In the first, the QC of the detector parameters should be performed. For this purpose, the FC2 and QC3 phantoms should be used, along with the Portal Image Processing System program (PIPSpro) package for data analysis. The second part of the QC of the linear accelerator's portal imaging system should include the QC of the CBCT. In this part a set of predefined manufacturer's tests using two different phantoms, one for the geometry calibration and the other for the image quality evaluation, should be performed. Also, the treatment conditions should be simulated using anthropomorphic phantoms and dose distributions for particular EPID protocols should be measured. Procedures for quality control of the portal imaging system developed and implemented at University Hospital Rijeka are presented in this paper.(author)

186

The impact of population change on the growth of mega-cities.  

Science.gov (United States)

The population dynamics of population growth in mega-cities and the contributions of migration to urban growth are described. The policy implications are identified as the need for a continued emphasis on fertility declines, because reductions will have a beneficial effect on reducing the pace of growth of mega-cities. The short-term goal of policy should be to provide urban contraceptive services to female migrants, who should be targeted specifically as a special group. Natural increase will be the main source of growth of mega-cities, and women who migrated during the 1990s will be a part of that natural increase. Reductions in population growth will make it easier for governments to provide services and to manage the large population size in mega-cities, which will continue to exist as long as economic activities are centralized and economic development promotes urbanization and spatial concentration. The emergence of mega-cities with populations of many millions has been a recent and increasing phenomena. The largest cities in 1980 were Tokyo with 16.9 million followed by New York City with 15.6 million. By 1990, the largest mega-cities were Mexico City with 20.2 million, Tokyo with 18.1 million, Sao Paulo with 17.4 million, and New York with 16.2 million. By the year 2000, the expectation is that Mexico City will have 25.6 million, Sao Paulo 22.1 million, Tokyo 19.0 million, Shanghai 17.0 million, and New York 16.8 million. The rankings will change, but the pattern clearly reflects the growth of mega-cities in developing countries. The age structure of urban populations is conducive to population growth. The main component of urban growth in Asia has been migration. Age structure changes have affected migration and will continue to affect fertility in mega-cities. Mega-cities will attract a young population because of the tourist and personnel services sectors which employ large numbers of young people, because of the demand for educated workers who tend to be younger, and because of enhanced opportunities for education. In Asia, economic policies encourage high levels of female labor force participation. PMID:12288070

Guest, P

1994-03-01

187

MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods.  

Science.gov (United States)

Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, biomedicine, and evolution. The newest addition in MEGA5 is a collection of maximum likelihood (ML) analyses for inferring evolutionary trees, selecting best-fit substitution models (nucleotide or amino acid), inferring ancestral states and sequences (along with probabilities), and estimating evolutionary rates site-by-site. In computer simulation analyses, ML tree inference algorithms in MEGA5 compared favorably with other software packages in terms of computational efficiency and the accuracy of the estimates of phylogenetic trees, substitution parameters, and rate variation among sites. The MEGA user interface has now been enhanced to be activity driven to make it easier for the use of both beginners and experienced scientists. This version of MEGA is intended for the Windows platform, and it has been configured for effective use on Mac OS X and Linux desktops. It is available free of charge from http://www.megasoftware.net. PMID:21546353

Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

2011-10-01

188

Plasmid associated with pathogenicity and calcium dependency of Yersinia enterocolitica.  

OpenAIRE

Studies of the virulence and plasmid properties of Yersinia enterocolitica revealed a plasmid, 42.2 +/- 1.1 megadaltons in size, which is associated with the pathogenicity and calcium dependency of this organism.

Gemski, P.; Lazere, J. R.; Casey, T.

1980-01-01

189

Plasmids in methanotrophic bacteria: isolation, characterization and DNA hybridization analysis  

Energy Technology Data Exchange (ETDEWEB)

Ten strains of obligate methanotrophs were screened for the presence of plasmid DNA using a variety of methods. Plasmids were detected in all strains except Methylococcus capsulatus Bath. No significant similarity between plasmids was observed with respect to size or restriction digest patterns except for three strains of Methylosinus trichosporium, which appeared to contain the same three plasmids. Nitrocellulose filter hybridization revealed that the plasmid DNA from the M. trichosporium strains shared a small region of homology with the plasmid DNA from Methylosinus sporium 5. All of the plasmids remain cryptic. As the first step in characterization, a restriction digest map of the 55 kb plasmid found in Methylomonas albus BG8 was constructed. 22 references, 4 figures, 3 tables.

Lidstrom, M.E.; Wopat, A.E.

1984-01-01

190

Mitotic and meiotic stability of linear plasmids in yeast.  

OpenAIRE

Circular recombinant DNA plasmids that contain autonomously replicating sequences (ARSs) are maintained in extrachromosomal form in transformed yeast cells. However, these plasmids are unstable, being rapidly lost from cells growing without selection. Although the stability of such a plasmid can be increased by the presence of yeast centromere DNA (CEN), even CEN plasmids are lost at a high rate compared to a bona fide yeast chromosome. Natural yeast chromosomes are linear molecules; therefor...

Dani, G. M.; Zakian, V. A.

1983-01-01

191

High-frequency rearrangements in Rhizobium leguminosarum bv. phaseoli plasmids.  

OpenAIRE

High-frequency genomic rearrangements affecting the plasmids of Rhizobium leguminosarum bv. phaseoli CFN42 were analyzed. This strain contains six large plasmids ranging in size from 200 to 600 kb. In the absence of any selective pressure, we found 11 strains from 320 analyzed colonies that presented different kinds of plasmid-borne rearrangements, including sequence amplification, deletion, cointegration, and loss of plasmids. These data support the concept that the R. leguminosarum bv. phas...

Brom, S.; Garci?a Los Santos, A.; Lourdes Girard, M.; Da?vila, G.; Palacios, R.; Romero, D.

1991-01-01

192

Self-transmissible plasmid in Zymomonas mobilis carrying antibiotic resistance.  

OpenAIRE

The cryptic plasmid pRUT41 from Zymomonas mobilis was examined for its biological properties. This plasmid was found to be conjugally transferred from Z. mobilis CP4 to Escherichia coli BM21 and to carry genes for antibiotic resistance (gentamicin, kanamycin, and streptomycin). Covalently closed circular plasmid DNA was isolated from eight transconjugants of E. coli BM21. These plasmids were identical in mobility on agarose gels and exhibited the same restriction patterns as the native pRUT41...

Walia, S. K.; Carey, V. C.; All, B. P.; Ingram, L. O.

1984-01-01

193

DISTRIBUTION OF PLASMIDS IN GROUNDWATER BACTERIA  

Science.gov (United States)

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...

194

Molecular delivery of plasmids for genetic vaccination.  

Science.gov (United States)

Plasmid vaccination is a smart gene delivery application mostly achieved through the utilisation of viral or copolymeric systems as surrogated carriers in micro or nano formulations. A common polymeric protocol for plasmid vaccine formulation, which as somewhat been successful, is via the complexation of the DNA molecules with a cationic polymer, and encapsulating in a vehicular carrier polymer. Even though plasmid vaccination research has not witnessed the much anticipated success, due a number of cellular and physicochemical reasons, application of copolymeric carriers with tight functionalities is a promising strategy to optimally deliver the DNA molecules; in view of the available chemistries and physical properties that could be tuned to enable enhanced targeted delivery, uptake and specific transfection. This also enables the targeting of specific epitopes and antigen presenting cells for the treatment of many pathogenic infections and cancer. This paper provides a brief critical review of the current state of plasmid vaccines formulation and molecular delivery with analysis of performance data obtained from clinical trials. PMID:24016267

Mazid, Romiza; Tan, Melvin X; Danquah, Michael K

2013-01-01

195

Transfer of IncN plasmids to Pseudomonas aeruginosa.  

OpenAIRE

Three of four N plasmids tested were found to be conjugatively transferable from Escherichia coli to Pseudomonas aeruginosa. The plasmids in the Pseudomonas transconjugants differed from the plasmids in the donor E. coli with respect to molecular weight, transfer ability, phenotype conferred, and stability. In some cases, the antibiotic and UV resistance genes appeared to integrate into the P. aeruginosa chromosome.

Tardif, G.; Grant, R. B.

1982-01-01

196

Compositional discordance between prokaryotic plasmids and host chromosomes  

Directory of Open Access Journals (Sweden)

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.

van Kampen Antoine HC

2006-02-01

197

Transfer of Plasmids between Bacillus subtilis and Streptococcus lactis  

OpenAIRE

The shuttle plasmid pGK12, as well as several Staphylococcus aureus plasmids, was introduced into Streptococcus lactis by intergeneric protoplast fusion with Bacillus subtilis. The S. aureus plasmids were stably inherited in S. lactis, and so they may possibly be used as cloning vectors in lactic streptococci.

Baigori?, Mario; Sesma, Fernando; Ruiz Holgado, Ai?da P.; Mendoza, Diego

1988-01-01

198

Plasmid mediated enhancement of uv resistance in Streptococcus faecalis  

International Nuclear Information System (INIS)

A 38.5-Mdal plasmid of Streptococcus faecalis subdp. zymogenes has been shown to enhance survival following uv irradiation. In addition, the presence of this plasmid increases the mutation frequencies following uv irradiation and enhanced W-reactivation. The data presented indicate that S. faecalis has an inducible error-prone repair system and that the plasmid enhances these repair functions

199

Mapping of trimethoprim resistance genes from epidemiologically related plasmids.  

OpenAIRE

Trimethoprim resistance dihydrofolate reductase genes from plasmids known to be exchanging between human and animal populations were mapped. The dihydrofolate reductase gene has been highly conserved in all plasmids, but differences in the flanking regions provide evidence that the most recent exchange of plasmids between the two ecosystems has been from animals to humans.

Campbell, I. G.; Mee, B. J.

1987-01-01

200

A Practical Data Recovery Technique for Long-Term Strain Monitoring of Mega Columns during Construction  

Directory of Open Access Journals (Sweden)

Full Text Available A practical data recovery method is proposed for the strain data lost during the safety monitoring of mega columns. The analytical relations among the measured strains are derived to recover the data lost due to unexpected errors in long-term measurement during construction. The proposed technique is applied to recovery of axial strain data of a mega column in an irregular building structure during construction. The axial strain monitoring using the wireless strain sensing system was carried out for one year and five months between 23 July 2010 and 22 February 2012. During the long-term strain sensing, three different types of measurement errors occurred. Using the recovery technique, the strain data that could not be measured at different intervals in the measurement were successfully recovered. It is confirmed that the problems that may occur during long-term wireless strain sensing of mega columns during construction could be resolved through the proposed recovery method.

Hyo Seon Park

2013-08-01

201

Pooling fMRI data: meta-analysis, mega-analysis and multi-center studies  

Directory of Open Access Journals (Sweden)

Full Text Available The quantitative analysis of pooled data from related fMRI experiments has the potential to significantly accelerate progress in brain mapping. Such data-pooling can be achieved through meta-analysis (the pooled analysis of published results, mega-analysis (the pooled analysis of raw data or multi-site studies which can be seen as designed mega-analyses. Current limitations in function-location brain mapping and how data-pooling can be used to remediate them are reviewed, with particular attention to power aggregation and mitigation of false positive results. Some recently developed analysis tools for meta- and mega-analysis are also presented, and recommendations for the conduct of valid fMRI data pooling are formulated.

SergiGCostafreda

2009-09-01

202

Refractory psychosis and prominent cognitive deficits in a patient with mega-cisterna magna.  

Science.gov (United States)

We present a case of refractory psychosis with prominent cognitive deficits in a patient with 'mega-cisterna magna', a congenital defect within the 'Dandy-Walker Complex' continuum. The 21-year-old female had a 3-year history of refractory psychotic symptoms despite adequate antipsychotic treatment. CT and MRI scans disclosed 'mega-cisterna magna'. Thorough neuropsychological testing recorded extensive deficits. Treatment with amisulpride 1200 mg/day resulted in a 30% decrease in PANSS score within 2 months. Then galantamine 8 mg/day was added and PANSS score decreased further by 27% within 2 weeks. Cognitive and social functioning was overall much improved. The effect was sustained in a 24 months follow-up. It is postulated that even a less extended cerebellar lesion, such as mega-cisterna magna, can be associated with psychosis, and in some cases with treatment refractoriness or cognitive dysfunction. Adjuvant galantamine may improve cognitive and psychosocial functioning in these patients. PMID:17150294

Ferentinos, Panayotis P; Kontaxakis, Vassilis P; Havaki-Kontaxaki, Beata J; Paplos, Konstantinos G; Pappa, Dimitra A; Soldatos, Constantin R

2007-03-30

203

Endogenous mutagenesis in recombinant sulfolobus plasmids.  

Science.gov (United States)

Low rates of replication errors in chromosomal genes of Sulfolobus spp. demonstrate that these extreme thermoacidophiles can maintain genome integrity in environments with high temperature and low pH. In contrast to this genetic stability, we observed unusually frequent mutation of the ?-D-glycosidase gene (lacS) of a shuttle plasmid (pJlacS) propagated in Sulfolobus acidocaldarius. The resulting Lac(-) mutants also grew faster than the Lac(+) parent, thereby amplifying the impact of the frequent lacS mutations on the population. We developed a mutant accumulation assay and corrections for the effects of copy number and differential growth for this system; the resulting measurements and calculations yielded a corrected rate of 5.1 × 10(-4) mutational events at the lacS gene per plasmid replication. Analysis of independent lacS mutants revealed three types of mutations: (i) G · C-to-A · T transitions, (ii) slipped-strand events, and (iii) deletions. These mutations were frequent in plasmid-borne lacS expressed at a high level but not in single-copy lacS in the chromosome or at lower levels of expression in a plasmid. Substitution mutations arose at only two of 12 potential priming sites of the DNA primase of the pRN1 replicon, but nearly all these mutations created nonsense (chain termination) codons. The spontaneous mutation rate of plasmid-borne lacS was 175-fold higher under high-expression than under low-expression conditions. The results suggest that important DNA repair or replication fidelity functions are impaired or overwhelmed in pJlacS, with results analogous to those of the "transcription-associated mutagenesis" seen in bacteria and eukaryotes. PMID:23564176

Sakofsky, Cynthia J; Grogan, Dennis W

2013-06-01

204

Yeast telomere repeat sequence (TRS) improves circular plasmid segregation, and TRS plasmid segregation involves the RAP1 gene product.  

OpenAIRE

Telomere repeat sequences (TRSs) can dramatically improve the segregation of unstable circular autonomously replicating sequence (ARS) plasmids in Saccharomyces cerevisiae. Deletion analysis demonstrated that yeast TRSs, which conform to the general sequence (C(1-3)A)n, are able to stabilize circular ARS plasmids. A number of TRS clones of different primary sequence and C(1-3)A tract length confer the plasmid stabilization phenotype. TRS sequences do not appear to improve plasmid replication ...

Longtine, M. S.; Enomoto, S.; Finstad, S. L.; Berman, J.

1992-01-01

205

What makes a “great resident”: the resident perspective  

OpenAIRE

Orthopedic surgery residency training is a difficult endeavor, and the selection of residents that will perform well in a rigorous training program is challenging for residency program directors. Even defining a “great” resident is a difficult endeavor. However, there are certain qualities that anecdotally are associated with high-performing residents, which include being trustworthy, hard-working and efficient, self-directed learners, detail-oriented, and personable. These qualities are ...

Nemani, Venu M.; Park, Caroline; Nawabi, Danyal H.

2014-01-01

206

Plasmids captured in C. metallidurans CH34: defining the PromA family of broad-host-range plasmids.  

Science.gov (United States)

The self-transmissible, broad-host-range (BHR) plasmid pMOL98 was previously isolated from polluted soil using a triparental plasmid capture approach and shown to possess a replicon similar to that of the BHR plasmids pSB102 and pIPO2. Here, complete sequence analysis and comparative genomics reveal that the 55.5 kb nucleotide sequence of pMOL98 shows extensive sequence similarity and synteny with the BHR plasmid family that now includes pIPO2, pSB102, pTER331, and pMRAD02. They share a plasmid backbone comprising replication, partitioning and conjugative transfer functions. Comparison of the variable accessory regions of these plasmids shows that the majority of natural transposons, as well as the mini-transposon used to mark the plasmids, are inserted in the parA locus. The transposon unique to pMOL98 appears to have inserted from the chromosome of the recipient strain used in the plasmid capture procedure. This demonstrates the necessity for careful screening of plasmids and host chromosomes to avoid mis-interpretation of plasmid genome content. The presence of very similar BHR plasmids with different accessory genes in geographically distinct locations suggests an important role in horizontal gene exchange and bacterial adaptation for this recently defined plasmid group, which we propose to name "PromA". PMID:19259779

Van der Auwera, Géraldine A; Król, Jaroslaw E; Suzuki, Haruo; Foster, Brian; Van Houdt, Rob; Brown, Celeste J; Mergeay, Max; Top, Eva M

2009-08-01

207

Exploring the solar system with Mega-Precovery data mining server: strengthening our database and functionalities  

Science.gov (United States)

Mega-Precovery is an online service focused on data mining few collections of instruments archives; with the aim to improve the orbital and physical knowledge of known asteroids and other Solar System objects. Mega-Precovery comprises a collection of millions of images which can be searched for serendipitous recoveries and precoveries (apparitions before discoveries). In this work we present a data mining of ESO WFI and INT WFC archives and some precoveries using this tool; developed within the European Near Earth Asteroid Research project (EURONEAR); in collaboration with the IMCCE Observatoire de Paris.

Char, F.; Vaduvescu, O.; Popescu, M.

208

Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results  

OpenAIRE

We present the first results of a wide field survey for cool brown dwarfs with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and to constrain the field-brown dwarf mass function thanks to a larger sample of L and T dwarfs. We identify candidates in CFHT/MegaCam i' and z' images using optimised psf-fitting within Source Extractor, and follow them up with pointed near-infrared ...

Delorme, Philippe; Willott, Chris; Forveille, Thierry; Delfosse, Xavier; Reyle?, Ce?line; Bertin, Emmanuel; Albert, Loic; Artigau, Etienne; Robin, Annie; Allard, France; Doyon, Rene; Hill, Gary

2008-01-01

209

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

Directory of Open Access Journals (Sweden)

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.

Mark Tomlinson

2011-06-01

210

Transformation of Kluyveromyces lactis by killer plasmid DNA.  

OpenAIRE

Some strains of Kluyveromyces lactis contain two linear double-stranded DNA plasmids, k1 and k2. The presence of the two plasmids confer on the cell a "killer" character, due to the production of a toxin that kills the sensitive cells. We have used one of these linear DNA molecules as a gene vector to transform K. lactis cells. Hybrid plasmids containing parts of the k1 plasmid and the URA3 gene of Saccharomyces cerevisiae have been constructed. We have found that the hybrid plasmids were abl...

Louvencourt, L.; Fukuhara, H.; Heslot, H.; Wesolowski, M.

1983-01-01

211

A mutant defective in partitioning of composite plasmid Rms201.  

OpenAIRE

Escherichia coli harboring mutant plasmids defective in maintenance stability (from the conjugative plasmid Rms201) showed a wide distribution of ampicillin resistance levels, as well as increased frequency of plasmid loss from the cell. The amounts of covalently closed circular deoxyribonucleic acid of mutant plasmid Rms268 and parental plasmid Rms201 per chromosome were 5.3 and 6.1%, respectively. The beta-lactamase activities of strains W3630(Rms268) and W3630(Rms201) were 0.56 and 0.44 U/...

Ike, Y.; Hashimoto, H.; Mitsuhashi, S.

1981-01-01

212

Metals removal from resids  

Energy Technology Data Exchange (ETDEWEB)

Many refiners today are asking how they should process heavy oil and resid. That is a difficult question, which must be faced as supplies of light crudes continue to decline and the markets for low-sulfur fuel oil disappear. This paper discusses the deep demetallation of resid conversion. Examples are given to illustrate the advantages of using a new demetallation, or metals-removal, catalyst upstream of a proven residuum-upgrading catalyst. This two-catalyst combination gives the unicracking/hydrodesulfurization (UK/HDS) technology the increased flexibility to process tougher, higher-metals-residua feedstocks and to operate longer at lower hydrogen pressures.

Miller, J.W.; Skripek, M.; Baron, K.; Lindsay, D.A.

1983-05-01

213

Integrated bariatric surgery residency  

Directory of Open Access Journals (Sweden)

Full Text Available Adam EM Eltorai Warren Alpert Medical School of Brown University, RI, USA Abstract: Obesity is a major public health concern. Given its lasting efficacy for improving obesity and obesity-related diseases, bariatric surgery is an increasingly common treatment option. As the implementation of the Affordable Care Act progresses, the impending physician shortage will become more severe. Thus there will be an even greater need for doctors specialized in the management and treatment of obese patients. The development of integrated bariatric surgery residency programs could be considered and is discussed herein. Keywords: obesity, bariatric surgery, integrated residency, surgery education

Eltorai AE

2014-11-01

214

Excellent Supervision: The Residents' Perspective  

OpenAIRE

Former residents rated their videotaped psychotherapy supervision sessions on how helpful their supervisors were as teachers during the session. Residents' and experts' ratings of the same videotape were compared and found to have no significant correlation. However, male residents were less critical than either female residents or experts. Former residents were also interviewed. Supervisors were rated as excellent when they were accepting and also when they provided guidance about highly cha...

Shanfield, Stephen B.; Hetherly, Vroni V.; Matthews, Kenneth L.

2001-01-01

215

Plasmid flux in Escherichia coli ST131 sublineages, analyzed by plasmid constellation network (PLACNET), a new method for plasmid reconstruction from whole genome sequences.  

Science.gov (United States)

Bacterial whole genome sequence (WGS) methods are rapidly overtaking classical sequence analysis. Many bacterial sequencing projects focus on mobilome changes, since macroevolutionary events, such as the acquisition or loss of mobile genetic elements, mainly plasmids, play essential roles in adaptive evolution. Existing WGS analysis protocols do not assort contigs between plasmids and the main chromosome, thus hampering full analysis of plasmid sequences. We developed a method (called plasmid constellation networks or PLACNET) that identifies, visualizes and analyzes plasmids in WGS projects by creating a network of contig interactions, thus allowing comprehensive plasmid analysis within WGS datasets. The workflow of the method is based on three types of data: assembly information (including scaffold links and coverage), comparison to reference sequences and plasmid-diagnostic sequence features. The resulting network is pruned by expert analysis, to eliminate confounding data, and implemented in a Cytoscape-based graphic representation. To demonstrate PLACNET sensitivity and efficacy, the plasmidome of the Escherichia coli lineage ST131 was analyzed. ST131 is a globally spread clonal group of extraintestinal pathogenic E. coli (ExPEC), comprising different sublineages with ability to acquire and spread antibiotic resistance and virulence genes via plasmids. Results show that plasmids flux in the evolution of this lineage, which is wide open for plasmid exchange. MOBF12/IncF plasmids were pervasive, adding just by themselves more than 350 protein families to the ST131 pangenome. Nearly 50% of the most frequent ?-proteobacterial plasmid groups were found to be present in our limited sample of ten analyzed ST131 genomes, which represent the main ST131 sublineages. PMID:25522143

Lanza, Val F; de Toro, María; Garcillán-Barcia, M Pilar; Mora, Azucena; Blanco, Jorge; Coque, Teresa M; de la Cruz, Fernando

2014-12-01

216

Role of Plasmid in Production of Acetobacter Xylinum Biofilms  

Directory of Open Access Journals (Sweden)

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.

Abbas Rezaee

2005-01-01

217

Plasmids isolated from marine sediment microbial communities contain replication and incompatibility regions unrelated to those of known plasmid groups.  

OpenAIRE

Two hundred ninety-seven bacteria carrying plasmids that range in size from 5 to 250 kb were identified from more than 1,000 aerobic heterotrophic bacteria isolated from coastal California marine sediments. While some isolates contained numerous (three to five) small (5- to 10-kb) plasmids, the majority of the natural isolates typically contained one large (40- to 100-kb) plasmid. By the method of plasmid isolation used in this study, the frequency of plasmid incidence ranged from 24 to 28% d...

Sobecky, P. A.; Mincer, T. J.; Chang, M. C.; Helinski, D. R.

1997-01-01

218

Water Molecule Residence Times  

Science.gov (United States)

How long will a molecule of Water stay in a particular reservoir? What is the average time a molecule of Water will stay in an ocean? What is the average time a molecule of water will stay in a river? A lake? As groundwater? A glacier? How long will a water vapor molecule stay suspended in the atmosphere? Why is the residence ...

Sill - Earth Systems Science

2010-11-16

219

Resident Intern Program.  

Science.gov (United States)

The Resident Intern Program is designed to teach methods courses in concert with student teaching in elementary education for two sequential semesters. The program included two schools identified cooperatively by the Memphis City Schools and Memphis State University. Twenty-two college students, 22 clinical teachers, and four university professors…

Philpot, James C.

220

Linear DNA plasmid pPK2 of Pichia kluyveri: distinction between cytoplasmic and mitochondrial linear plasmids in yeasts.  

Science.gov (United States)

The linear plasmids frequently found in plants and filamentous fungi are associated with mitochondria or chloroplasts. In contrast, all the linear plasmids known in yeasts are cytoplasmic elements. From a strain of the yeast Pichia kluyveri, we have isolated a new linear plasmid, pPK2, which was found to be associated with mitochondria. This 7.1 kilobase pairs-long DNA contained only two genes, which code for DNA and RNA polymerases, as judged from their nucleotide sequences translated by a mitochondrial genetic code. When we examined several recently isolated yeast plasmids for their subcellular localization, we found that two linear plasmids, pPH1 from Pichia heedii, as well as pPK1 from another strain of P. kluyveri, were also localized in mitochondria. These plasmids are the first examples of mitochondria-associated linear plasmids in yeast. All other linear plasmids we examined were of cytoplasmic origin. Whilst the cytoplasmic type linear plasmids were efficiently eliminated by ultraviolet irradiation of host cells, the mitochondria-associated plasmids were highly resistant. The mitochondrial pPK2 plasmid was rapidly lost by treatment of the host cells with ethidum bromide. PMID:10398346

Blaisonneau, J; Nosek, J; Fukuhara, H

1999-06-30

221

Plasmid-mediated quinolone resistance in Australia.  

Science.gov (United States)

The aim of this study was to search for plasmid-encoded quinolone resistance determinants QnrA and QnrS in fluoroquinolone-resistant and extended-spectrum beta-lactamase (ESBL)-producing enterobacterial isolates recovered in Sydney, Australia, in 2002. Twenty-three fluoroquinolone-resistant, of which 16 were also ESBL-positive, enterobacterial and nonrelated isolates were studied. PCR with primers specific for qnrA and qnrS genes and primers specific for a series of ESBL genes were used. A qnrA gene was identified in two ESBL-positive isolates, whereas no qnrS-positive strain was found. The QnrA1 determinant was identified in an Enterobacter cloacae isolate and in a carbapenem-resistant Klebsiella pneumoniae isolate, both of which expressed the same ESBL SHV- 12. Whereas no plasmid was identified in the E. cloacae isolate, K. pneumoniae K149 possessed two conjugative plasmids, one that harbored the qnrA and bla (SHV)-12 genes whereas the other expressed the carbapenemase gene bla (IMP-4). The qnrA gene, was located in both cases downstream of the orf513 recombinase gene and upstream of the qnrA1 gene, a structure identical to that found in sul1-type integron In36 and qnrA-positive strains from Shanghai, China. However, the gene cassettes of the sul1-type integrons were different. This study identified the first plasmid-mediated quinolone resistance determinant in Enterobacteriaceae in Australia. PMID:16922624

Rodriguez-Martinez, Jose-Manuel; Poirel, Laurent; Pascual, Alvaro; Nordmann, Patrice

2006-01-01

222

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

Science.gov (United States)

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-wave vibro-seismic array investigation presents a clear contrast between the hanging wall and footwall. The results indicate how the fossilized megasplay fault is useful to investigate the primary properties in depth,excluding the secondary effects associated with exhumation and surface weathering.

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

223

The Alliance for Cellular Signaling Plasmid Collection  

Science.gov (United States)

Cellular responses to inputs that vary both temporally and spatially are determined by complex relationships between the components of cell signaling networks. Analysis of these relationships requires access to a wide range of experimental reagents and techniques, including the ability to express the protein components of the model cells in a variety of contexts. As part of the Alliance for Cellular Signaling, we developed a robust method for cloning large numbers of signaling ORFs into Gateway® entry vectors, and we created a wide range of compatible expression platforms for proteomics applications. To date, we have generated over 3000 plasmids that are available to the scientific community via the American Type Culture Collection. We have established a website at www.signaling-gateway.org/data/plasmid/ that allows users to browse, search, and blast Alliance for Cellular Signaling plasmids. The collection primarily contains murine signaling ORFs with an emphasis on kinases and G protein signaling genes. Here we describe the cloning, databasing, and application of this proteomics resource for large scale subcellular localization screens in mammalian cell lines. PMID:17192258

Zavzavadjian, Joelle R.; Couture, Sam; Park, Wei Sun; Whalen, James; Lyon, Stephen; Lee, Genie; Fung, Eileen; Mi, Qingli; Liu, Jamie; Wall, Estelle; Santat, Leah; Dhandapani, Kavitha; Kivork, Christine; Driver, Adrienne; Zhu, Xiaocui; Chang, Mi Sook; Randhawa, Baljinder; Gehrig, Elizabeth; Bryan, Heather; Verghese, Mary; Maer, Andreia; Saunders, Brian; Ning, Yuhong; Subramaniam, Shankar; Meyer, Tobias; Simon, Melvin I.; O’Rourke, Nancy; Chandy, Grischa; Fraser, Iain D. C.

2012-01-01

224

Symmetry breaking in homo-oligomers: the curious case of mega-hemocyanin.  

Science.gov (United States)

Mega-hemocyanin is a 13.5 MDa oxygen transporter found in snails. It is built from three stacked rings involving ten subunits each. The cryo-EM structure of the complex presented by Gatsogiannis and colleagues in this issue of Structure revealed an unexpected breaking of 5-fold symmetry in the central ring and a nonequivalent packing of the subunits. PMID:25565100

Garcia Seisdedos, Hector; Steinberg, Avital; Levy, Emmanuel D

2015-01-01

225

Aspectos raciais dos "megas" e da cardiopatia na doença de Chagas crônica  

Directory of Open Access Journals (Sweden)

Full Text Available O estudo de 724 pacientes chagásicos crônicos mostrou que a insuficiência cardíaca congestiva é mais freqüente e de aparecimento mais precoce nos pacientes de raça negra do que nos brancos. A ocorrência de "megas" foi ligeiramente inferior nos chagásicos negros não sendo estatisticamente significativa a diferença observada. A maior freqüência de insuficiência cardíaca nos pretos parece estar relacionada a características biológicas do tecido conjuntivo que condicionam uma resposta fibrosante mais acentuada no miocârdio agredido pela Tripanossomose. Estas observações estariam de acordo com outros estudos sobre a doença de Chagas que admitem ser a denervação o fator mais importante para o aparecimento dos "megas" e a inflamação com fibrose miocârdica acentuada um elemento básico para explicar a insuficiência cardíaca.The study of 724 patients with chronic chagas's disease showed that the cardiac faiture is more frequent and appears earlier in negroes patients when compared to white patients. The occurrence of "megas" was slightly lover in the negroes but the difference was not statisticaiiy significant. The higher frequency of cardiac faiture in the negrões seems to be caused by biological characteristics of the conective tissue which respond to trypanossomiasis with a more severe degree of fibrosis. These findings agree with other reports on Chagas's disease in which it is admitted that the "megas" are chiefly the result of dennervation and cardiac faiture is principally caused by infiammation with myocardial fibrosis.

Lineu José Miziara

1981-06-01

226

Development and calibration of the tracking Compton/Pair telescope MEGA  

Energy Technology Data Exchange (ETDEWEB)

We describe the development and tests of the prototype for a new telescope for Medium Energy Gamma-ray Astronomy (MEGA) in the energy band 0.4-50 MeV. As a successor to COMPTEL and EGRET (at low energies), MEGA aims to improve the sensitivity for astronomical sources by at least an order of magnitude. It could thus fill the severe sensitivity gap between scheduled or operating hard-X-ray and high-energy gamma-ray missions and open the way for a future Advanced Compton Telescope. MEGA records and images {gamma}-rays by completely tracking Compton and Pair creation events in a stack of double-sided Si-strip track detectors surrounded by a pixelated CsI calorimeter. A scaled down prototype has been built and we describe technical details of its design and properties. Results from calibrations using radioactive sources and from measurements with an accelerator generated, fully polarized, {gamma}-ray beam are presented and an outlook to future plans with MEGA is given.

Kanbach, G. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany)]. E-mail: gok@mpe.mpg.de; Andritschke, R. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Zoglauer, A. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Ajello, M. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); McConnell, M.L. [Space Science Center, University of New Hampshire, Durham, NH (United States); Macri, J.R. [Space Science Center, University of New Hampshire, Durham, NH (United States); Ryan, J.M. [Space Science Center, University of New Hampshire, Durham, NH (United States); Bloser, P. [Goddard Space Flight Center, NASA, Greenbelt, MD (United States); Hunter, S. [Goddard Space Flight Center, NASA, Greenbelt, MD (United States); DiCocco, G. [IASF/CNR, Bologna (Italy); Kurfess, J. [Naval Research Laboratory, Washington, DC (United States); Reglero, V. [GACE, University of Valencia (Spain)

2005-04-01

227

Mega-precovery and data mining of near-Earth asteroids and other Solar System objects  

Science.gov (United States)

The vast collection of CCD images and photographic plate archives available from the world-wide archives and telescopes is still insufficiently exploited. Within the EURONEAR project we designed two data mining software with the purpose to search very large collections of archives for images which serendipitously include known asteroids or comets in their field, with the main aims to extend the arc and improve the orbits. In this sense, ''Precovery'' (published in 2008, aiming to search all known NEAs in few archives via IMCCE's SkyBoT server) and ''Mega-Precovery'' (published in 2010, querying the IMCCE's Miriade server) were made available to the community via the EURONEAR website (euronear.imcce.fr). Briefly, Mega-Precovery aims to search one or a few known asteroids or comets in a mega-collection including millions of images from some of the largest observatory archives: ESO (15 instruments served by ESO Archive including VLT), NVO (8 instruments served by U.S. NVO Archive), CADC (11 instruments, including HST and Gemini), plus other important instrument archives: SDSS, CFHTLS, INT-WFC, Subaru-SuprimeCam and AAT-WFI, adding together 39 instruments and 4.3 million images (Mar 2014), and our Mega-Archive is growing. Here we present some of the most important results obtained with our data-mining software and some new planned search options of Mega-Precovery. Particularly, the following capabilities will be added soon: the ING archive (all imaging cameras) will be included and new search options will be made available (such as query by orbital elements and by observations) to be able to target new Solar System objects such as Virtual Impactors, bolides, planetary satellites, TNOs (besides the comets added recently). In order to better characterize the archives, we introduce the ''AOmegaA'' factor (archival etendue) proportional to the AOmega (etendue) and the number of images in an archive. With the aim to enlarge the Mega-Archive database, we invite the observatories (particularly those storing their images online and also those that own plate archives which could be scanned on request) to contact us in order to add their instrument archives (consisting of an ASCII file with telescope pointings in a simple format) to our Mega-Precovery open project. We intend for the future to synchronise our service with the Virtual Observatory.

Popescu, M.; Vaduvescu, O.; Char, F.; Curelaru, L.; Euronear Team

2014-07-01

228

3-D geometry and physical property of the Mega-Splay Fault in Nankai trough  

Science.gov (United States)

The Nankai trough is a subduction zone, where the Philippine Sea plate is being subducted beneath southwest Japan at a rate of ~4-6.5 cm/y at an azimuth of ~300°-315°. A lot of operations have been done in Nankai, such as three-dimensional seismic reflection surveys and Deep Sea Drilling Project (DSDP), Ocean Drilling Program (ODP), Integrated Ocean Drilling Program (IODP). They revealed that there is a large splay fault, referred to as 'Mega-Splay'. The Mega-Splay Fault has caused a series of catastrophic earthquakes and submarine landslides, which may have led to TSUNAMI. Since fault development history may have affected the geometry of the Mega-Splay Fault and physical property within the fault zone, they need to be examined in detail. In this research, we used 3-D pre-stack depth migration (PSDM), 3-D pre-stack time migration (PSTM) and P-wave velocity in C0004B well (Logging data), in order to interpret 3-D structure of Mega-Splay Fault. The analysis in this research is basically divided into two parts. One is structural interpretation of Splay Fault, based on the high amplitude reflection surface on seismic profiles. The other part is acoustic impedance inversion (AI inversion), in which we inverted seismic waveform into physical property (in this study, acoustic impedance), with the P-wave velocity data at C0004B near Mega-Splay Fault. The 3-D PSDM (or PSTM) clearly images details of Splay Fault, with good continuity of reflections along the fault. It is possible on each seismic profile to trace the high amplitude lines, where rock-properties significantly change. Since Mega-Splay Fault has 45-59m width along the wells, we interpreted the upper limit and the lower limit of the Mega-Splay Fault, based on the high amplitude surfaces along 3-D PSDM. Our interpretation shows that the width of Mega-Splay Fault has variation along the fault, and the plan geometry of the fault toe has a salient at the middle of the 3D box area, suggesting the fault could be divided into two segments: the eastern part and western part. In AI inversion, the 3-D PSTM and P-wave velocity at C0004B were used to build a physical property model around Mega-Splay Fault. AI Inversion is a methodology to invert seismic waveforms with physical property data, into acoustic impedance. Acoustic Impedance governs the ability of a rock to allow the passage of an acoustic wave. In this analysis, we used Hampson-Russell STRATA to perform post-stack seismic inversion. Our results show that there is a low acoustic impedance layer in the upper zone of Splay Fault. 3-D distribution of the low acoustic impedance layer in the fault zone has a variation in the width, similar to the 3-D interpretation of the geometry. This suggests that there are a relationship between structural geometry and physical property along the Mega-Splay Fault.

Masui, R.; Tsuji, T.; Yamada, Y.; Environmental Resource; System Engineering laboratory

2011-12-01

229

Plasmid transfer between bacteria in soil microcosms and the field  

Directory of Open Access Journals (Sweden)

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.

Eric Smit

1997-01-01

230

MegaMIR: The Megapixel Mid-Infrared Instrument for the Large Binocular Telescope Interferometer  

Science.gov (United States)

The Megapixel Mid-infrared Instrument (MegaMIR) is a proposed Fizeau-mode camera for the Large Binocular Telescope operating at wavelengths between 5 and 28 micrometers. The camera will be used in conjunction with the Large Binocular Telescope Interferometer (LBTI), a cryogenic optical system that combines the beams from twin 8.4-m telescopes in a phase coherent manner. Unlike other interferometric systems, the co-mounted telescopes on the LBT satisfy the sine condition, providing diffraction-limited resolution over the 40" field of view of the camera. With a 22.8-m baseline, MegaMIR will yield 0.1" angular resolution, making it the highest resolution wide field imager in the thermal infrared for at least the next decade. MegaMIR will utilize a newly developed 1024 x 1024 pixel Si:As detector array that has been optimized for use at high backgrounds. This new detector is a derivative of the Wide-field Infrared Survey Explorer (WISE) low-background detector. The combination of high angular resolution and wide field imaging will be a unique scientific capability for astronomy. Key benefits will be realized in planetary science, galactic, and extra-galactic astronomy. High angular resolution is essential to disentangle highly complex sources, particularly in star formation regions and external galaxies, and MegaMIR provides this performance over a full field of view. Because of the great impact being made by space observatories like the Spitzer Space Telescope, the number of available targets for study has greatly increased in recent years, and MegaMIR will allow efficient follow up science.

Mainzer, Amanda K.; Young, Erick; Hong, John; Werner, Mike; Hinz, Phil; Gorjan, Varoujan; Ressler, Michael E.

2006-01-01

231

Psychiatric Pharmacy Residency Training*  

OpenAIRE

The role of the psychiatric pharmacist in the care of the mentally ill has continually evolved since the late 1960s and early 1970s. Pharmacists in the field of psychiatric pharmacy work to improve the health, safety, and welfare of those impacted by one or more psychiatric conditions. Specialty residency training programs are accredited to establish minimum training standards and a board-certification process ensures that individuals provide a high level of quality of care. It is the positio...

Stoner, Steven C.; Ott, Carol A.; Dipaula, Bethany A.

2010-01-01

232

Conjugative mobilization of a vancomycin resistance plasmid by a putative Enterococcus faecium sex pheromone response plasmid.  

Science.gov (United States)

Recent epidemiological evidence suggests that horizontal gene transfer may be an important mechanism for dissemination of vancomycin resistance. A filter mating survey of 21 VanA Enterococcus faecium isolates from The New York Hospital showed that 14 of these isolates transferred vancomycin resistance (Vmr) to the plasmid-free reference strain Enterococcus faecalis JH2-2. One isolate, E. faecium R7, was selected for further study based on its ability to transfer Vmr to strain JH2-2 in liquid culture. Analysis of the plasmid content of transconjugants revealed three general classes. The predominant class (28 of 47 transconjugants) contained two separate plasmids: pHKK702 and pHKK703. pHKK702 is a 41-kb plasmid that contains an element indistinguishable from the Vmr transposon Tn1546 and an element that hybridizes with an ermB probe from the Staphylococcus aureus erythromycin resistance transposon Tn551. pHKK703 is a 55-kb plasmid that hybridizes with probes for the sex pheromone response genes prgA, prgB, and prgX derived from the E. faecalis plasmid pCF10. The second group of transconjugants (18 of 47) contained various recombinant forms of pHKK702 and pHKK703, whereas a third transconjugant class contained only pHKK702 (1 of 47). Transconjugants that contained both pHKK702 and pHKK703 were able to efficiently transfer Vmr to recipient strains in broth or on filters. However, no transfer of Vmr was detected using the donor containing only pHKK702. The transfer of Vmr from the recombination-deficient derivative of E. faecalis JH2-2 [strain UV202(pHKK702, pHKK703)] was reduced 600-fold compared to that of JH2-2(pHKK702, pHKK703). We propose that pHKK703 functions as an E. faecium sex pheromone response plasmid that conjugatively mobilizes pHKK702, and that a major pathway for this mobilization may require donor-mediated recombination proficiency. This report provides the first example in which a plasmid containing a Tn1546-related element is conjugatively mobilized. PMID:9158753

Heaton, M P; Handwerger, S

1995-01-01

233

Plasmid Introduction in Metal-Stressed, Subsurface-Derived Microcosms: Plasmid Fate and Community Response  

OpenAIRE

The nonconjugal IncQ plasmids pMOL187 and pMOL222, which contain the metal resistance-encoding genes czc and ncc, were introduced by using Escherichia coli as a transitory delivery strain into microcosms containing subsurface-derived parent materials. The microcosms were semicontinuously dosed with an artificial groundwater to set a low-carbon flux and a target metal stress (0, 10, 100, and 1,000 ?M CdCl2), permitting long-term community monitoring. The broad-host-range IncP? plasmid RP4 wa...

Smets, Barth F.; Morrow, Jayne B.; Arango Pinedo, Catalina

2003-01-01

234

Expected residence time model  

International Nuclear Information System (INIS)

The Transportation Technology Department of Sandia National Laboratories develops analytical and computational tools for the US Department of Energy to assess the radiological consequences and risks from the transportation of radioactive materials by all modes. When large quantities of materials are to be transported movements may occur over an extended period of time in what is collectively referred as a ''shipping campaign''. Since the routes over which the shipments occur often remain the same, cumulative exposure to individuals inhabiting the population zones adjacent to the transport links must be estimated. However, individuals do not remain in the same residences throughout their lifetimes and, in fact, move quite often. To appropriately allocate exposures among populations over extended periods of time, perhaps years, requires a model that accounts for three population categories; (1) the original populations residing in the areas adjacent to the transport links, (2) individuals moving out and (3) individuals moving into residences in the designated areas. The model described here accounts for these conditions and will be incorporated as a user option in the RADTRAN computer code for transportation consequence and risk analysis (Reference 1). RADTRAN is a computer code for estimating the consequences and risks associated with the transport of radioactive materials

235

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

Science.gov (United States)

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 plasmids specifically. Colony blots revealed that the par and repB regions of the S. typhimurium virulence plasmid hybridized with 80% of the isolates of S. choleraesuis, S. dublin, S. enteritidis, S. gallinarum, S. pullorum, and S. typhimurium, while the repC region was not detected in any of the isolates of S. dublin, S. gallinarum, or S. pullorum. None of these maintenance regions was found in any of the 30 additional serovars tested. The large plasmids of those serovars that hybridized with par were labeled with a Kmr insert within parA via P22HTint or P1L4 transduction, which destabilized the plasmids and allowed the rapid isolation of plasmid-free derivatives for all of the serovars, except for S. dublin, which exhibited weak homology with par. PMID:2167294

Tinge, S A; Curtiss, R

1990-09-01

236

Transformation of Haemophilus influenzae by plasmid RSF0885  

International Nuclear Information System (INIS)

Plasmid RSF0885, which conferred ampicillin resistance, transformed competent Haemophilus influenzae cells with low efficiency (maximun, less than 0.01%). As judged by competition experiments and uptake of radioactivity, plasmid RSF0885 deoxyribonucleic acid was taken up into competent H. influenzae cells several orders of magnitude less efficiently than H. influenzae chromosomal deoxyribonucleic acid. Plasmid RSF0885 transformed cells with even lower efficiency than could be accounted for by the low uptake. Transformation was not affected by rec-1 and rec-2 mutations in the recipient, and strains cured of the plasmid did not show increased transformation. Plasmid molecules cut once with a restriction enzyme that made blunt ends did not transform. Transformation was favored by the closed circular form of the plasmid

237

Isolation of Clinical Strains of Pseudomonas aeruginosa Harboring Different Plasmids  

Directory of Open Access Journals (Sweden)

Full Text Available Aim of this study was to investigate the presence of plasmids among the strains of P. aeruginosa isolated from clinically diagnosed cases in Tehran in 2006. A total of 38 strains of P. aeruginosa were isolated. With the exception of one isolate, all P. aeruginosa strains harbored at least one plasmid band. The electrophoretic analysis of plasmid DNAs showed different number of plasmid bands among the strains tested. The DNA band of 1.4 kbp was evident in 84.2% of the strains. Approximately 71 and 21% of the isolates harbored concomitantly two and three plasmids, respectively. Isolation of strains with diverse types of plasmids suggests the different cluster of P. aeruginosa might be disseminated during the current study period.

R. Ranjbar

2007-01-01

238

[Conjugative R plasmids isolated from hospital strains of Pseudomonas aeruginosa].  

Science.gov (United States)

It was shown that Pseudomonas aeruginosa hospital strains isolated from patients and environment in the Republican Centre of Burns in Tbilisi contained conjugative R plasmids. The plasmids were marked pM15 and pM19, respectively. The plasmid pM15 determined resistance to carbenicillin, kanamycin and tetracycline and plasmid pM19 determined resistance to carbenicillin, kanamycin, tetracycline, chloramphenicol, gentamicin and streptomycin. Plasmid pM15 had a molecular weight of 45.8 MD and seven sites for EcoRI, six sites for HindIII and five sites for Hpa-I-restrictase. This plasmid, as others, belongs to the Inc-P1 incompatibility group. PMID:1304129

Gabisoniia, T G; Galushka, F P; Chanishvili, T G

1992-12-01

239

Exogenous Isolation of Mobilizing Plasmids from Polluted Soils and Sludges  

OpenAIRE

Exogenous plasmid isolation was used to assess the presence of mobilizing plasmids in several soils and activated sludges. Triparental matings were performed with Escherichia coli (a member of the ? subgroup of the Proteobacteria) as the donor of an IncQ plasmid (pMOL155, containing the heavy metal resistance genes czc: Cor, Znr, and Cdr), Alcaligenes eutrophus (a member of the ? subgroup of the Proteobacteria) as the recipient, and indigenous microorganisms from soil and sludge samples as ...

Top, Eva; Smet, Ingrid; Verstraete, Willy; Dijkmans, Roger; Mergeay, Max

1994-01-01

240

Establishment of a Replicating Plasmid in Rickettsia prowazekii  

OpenAIRE

Rickettsia prowazekii, the causative agent of epidemic typhus, grows only within the cytosol of eukaryotic host cells. This obligate intracellular lifestyle has restricted the genetic analysis of this pathogen and critical tools, such as replicating plasmid vectors, have not been developed for this species. Although replicating plasmids have not been reported in R. prowazekii, the existence of well-characterized plasmids in several less pathogenic rickettsial species provides an opportunity t...

Wood, David O.; Hines, Andria; Tucker, Aimee M.; Woodard, Andrew; Driskell, Lonnie O.; Burkhardt, Nicole Y.; Kurtti, Timothy J.; Baldridge, Gerald D.; Munderloh, Ulrike G.

2012-01-01

241

Genomic comparison of archaeal conjugative plasmids from Sulfolobus  

OpenAIRE

All of the known self-transmissable plasmids of the Archaea have been found in the genus Sulfolobus. To gain more insight into archaeal conjugative processes, four newly isolated self-transmissable plasmids, pKEF9, pHVE14, pARN3 and pARN4, were sequenced and subjected to a comparative sequence analysis with two earlier sequenced plasmids, pNOB8 and pING1. The analyses revealed three conserved and functionally distin...

Bo Greve; Susanne Jensen; Kim Brügger; Wolfram Zillig; Garrett, Roger A.

2004-01-01

242

Comparative genetic organization of incompatibility group P degradative plasmids.  

OpenAIRE

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...

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

1990-01-01

243

Plasmid Recombination in a Rad52 Mutant of Saccharomyces Cerevisiae  

OpenAIRE

Using plasmids capable of undergoing intramolecular recombination, we have compared the rates and the molecular outcomes of recombination events in a wild-type and a rad52 strain of Saccharomyces cerevisiae. The plasmids contain his3 heteroalleles oriented in either an inverted or a direct repeat. Inverted repeat plasmids recombine approximately 20-fold less frequently in the mutant than in the wild-type strain. Most events from both cell types have continuous coconversion tracts extending al...

Dornfeld, K. J.; Livingston, D. M.

1992-01-01

244

Ultrafiltration of supercoiled plasmid DNA : modeling and application  

OpenAIRE

A mass transfer model is proposed for predicting sieving coefficients, Sobs, of supercoiled plasmid DNA (pDNA), in the presence of a salt, in membranes with narrow pores, i.e., pores smaller than the gyration radii of the plasmids to be considered for a certain application. The model assumes that permeation occurs due to plasmid suction at the membrane surface as a result of the convective flow, being the probability of permeation also dependent on the instantaneous molecular conformation of ...

Mora?o, A.; Nunes, J. C.; Sousa, Fani; Amorim, M. T. Pessoa; Escobar, I. C.; Queiroz, J. A.

2011-01-01

245

Plasmid-associated sensitivity of Bacillus thuringiensis to UV light.  

OpenAIRE

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 e...

Benoit, T. G.; Wilson, G. R.; Bull, D. L.; Aronson, A. I.

1990-01-01

246

Vertical Transmission of Biosynthetic Plasmids in Aphid Endosymbionts (Buchnera)  

OpenAIRE

This study tested for horizontal transfer of plasmids among Buchnera aphidicola strains associated with ecologically and phylogenetically related aphid hosts (Uroleucon species). Phylogenetic congruence of Buchnera plasmid (trpEG and leuABC) and chromosomal (dnaN and trpB) genes supports strictly vertical long-term transmission of plasmids, which persist due to their contributions to host nutrition rather than capacity for infectious transfer. Synonymous divergences indicate elevated mutation...

Wernegreen, Jennifer J.; Moran, Nancy A.

2001-01-01

247

Transformation of Rhizobium meliloti 41 with plasmid DNA.  

OpenAIRE

Plasmid pGV1106, a derivative of the wide-host-range plasmid S-a of the W incompatibility group, was introduced into Rhizobium meliloti 41 by plasmid-mediated mobilization to overcome the restriction of foreign DNA. The mobilized plasmid pKK2 differed from the original pGV1106 by an extra piece of DNA of 1.3 kilobase pairs which supposedly originated from pJB3JI used for mobilization. If pKK2 was isolated from R. meliloti 41, it could be successfully reintroduced by transformation. The transf...

Kiss, G. B.; Ka?lma?n, Z.

1982-01-01

248

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

Science.gov (United States)

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 P2?2?2?. PMID:24100563

Carr, Stephen B; Mecia, Lauren B; Phillips, Simon E V; Thomas, Christopher D

2013-10-01

249

Comparative evolutionary diversity and phylogenetic structure across multiple forest dynamics plots: a mega-phylogeny approach  

Science.gov (United States)

Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of phylogenetic diversity in the mega-phylogeny were more consistent, thereby removing a potential source of bias at the plot-level, and demonstrating the value of assessing phylogenetic relationships simultaneously within a mega-phylogeny. An unexpected result of the comparisons among plots based on the mega-phylogeny was that the communities in the ForestGEO plots in general appear to be assemblages of more closely related species than expected by chance, and that differentiation among communities is very low, suggesting deep floristic connections among communities and new avenues for future analyses in community ecology. PMID:25414723

Erickson, David L.; Jones, Frank A.; Swenson, Nathan G.; Pei, Nancai; Bourg, Norman A.; Chen, Wenna; Davies, Stuart J.; Ge, Xue-jun; Hao, Zhanqing; Howe, Robert W.; Huang, Chun-Lin; Larson, Andrew J.; Lum, Shawn K. Y.; Lutz, James A.; Ma, Keping; Meegaskumbura, Madhava; Mi, Xiangcheng; Parker, John D.; Fang-Sun, I.; Wright, S. Joseph; Wolf, Amy T.; Ye, W.; Xing, Dingliang; Zimmerman, Jess K.; Kress, W. John

2014-01-01

250

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

Science.gov (United States)

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 deformation in the maximum depth >10km. Temperature difference between the hanging wall and footwall suggests the displacement along the Nobeoka thrust is >10km, which is almost similar to the mega-splay fault in the Nankai Trough. Geological and physical properties of the Nobeoka thrust suggest an evolving process of the seismogenic mega-splay fault associated with seismogenic up-thrust of the inner wedge of the accretionary prism.

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

2013-12-01

251

Molluscan mega-hemocyanin: an ancient oxygen carrier tuned by a ~550 kDa polypeptide  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The allosteric respiratory protein hemocyanin occurs in gastropods as tubular di-, tri- and multimers of a 35 × 18 nm, ring-like decamer with a collar complex at one opening. The decamer comprises five subunit dimers. The subunit, a 400 kDa polypeptide, is a concatenation of eight paralogous functional units. Their exact topology within the quaternary structure has recently been solved by 3D electron microscopy, providing a molecular model of an entire didecamer (two conjoined decamers. Here we study keyhole limpet hemocyanin (KLH2 tridecamers to unravel the exact association mode of the third decamer. Moreover, we introduce and describe a more complex type of hemocyanin tridecamer discovered in fresh/brackish-water cerithioid snails (Leptoxis, Melanoides, Terebralia. Results The "typical" KLH2 tridecamer is partially hollow, whereas the cerithioid tridecamer is almost completely filled with material; it was therefore termed "mega-hemocyanin". In both types, the staggering angle between adjoining decamers is 36°. The cerithioid tridecamer comprises two typical decamers based on the canonical 400 kDa subunit, flanking a central "mega-decamer" composed of ten unique ~550 kDa subunits. The additional ~150 kDa per subunit substantially enlarge the internal collar complex. Preliminary oxygen binding measurements indicate a moderate hemocyanin oxygen affinity in Leptoxis (p50 ~9 mmHg, and a very high affinity in Melanoides (~3 mmHg and Terebralia (~2 mmHg. Species-specific and individual variation in the proportions of the two subunit types was also observed, leading to differences in the oligomeric states found in the hemolymph. Conclusions In cerithioid hemocyanin tridecamers ("mega-hemocyanin" the collar complex of the central decamer is substantially enlarged and modified. The preliminary O2 binding curves indicate that there are species-specific functional differences in the cerithioid mega-hemocyanins which might reflect different physiological tolerances of these gill-breathing animals. The observed differential expression of the two subunit types of mega-hemocyanin might allow individual respiratory acclimatization. We hypothesize that mega-hemocyanin is a key character supporting the adaptive radiation and invasive capacity of cerithioid snails.

Harasewych Myroslaw G

2010-05-01

252

Comparative evolutionary diversity and phylogenetic structure across multiple forest dynamics plots: a mega-phylogeny approach.  

Science.gov (United States)

Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of phylogenetic diversity in the mega-phylogeny were more consistent, thereby removing a potential source of bias at the plot-level, and demonstrating the value of assessing phylogenetic relationships simultaneously within a mega-phylogeny. An unexpected result of the comparisons among plots based on the mega-phylogeny was that the communities in the ForestGEO plots in general appear to be assemblages of more closely related species than expected by chance, and that differentiation among communities is very low, suggesting deep floristic connections among communities and new avenues for future analyses in community ecology. PMID:25414723

Erickson, David L; Jones, Frank A; Swenson, Nathan G; Pei, Nancai; Bourg, Norman A; Chen, Wenna; Davies, Stuart J; Ge, Xue-Jun; Hao, Zhanqing; Howe, Robert W; Huang, Chun-Lin; Larson, Andrew J; Lum, Shawn K Y; Lutz, James A; Ma, Keping; Meegaskumbura, Madhava; Mi, Xiangcheng; Parker, John D; Fang-Sun, I; Wright, S Joseph; Wolf, Amy T; Ye, W; Xing, Dingliang; Zimmerman, Jess K; Kress, W John

2014-01-01

253

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

Science.gov (United States)

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...

254

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

Directory of Open Access Journals (Sweden)

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.

Lay Donald

2009-07-01

255

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

Science.gov (United States)

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....

256

Nerina Residence: Poster  

OpenAIRE

Built in 1921, this building initially belonged to the Loreto Convent School which was officially opened in 1924. In the 1940s the building was upgraded to a double-storey structure and a right wing was added. The University purchased Brostowe Hall, as it was called, in 1974 and acquired the rest of the convent in 1977. The complex was converted into a women’s residence and in 1992 renamed Nerina. The building is a rare example of the Art Nouveau style, featuring decorative motifs such as c...

Pollastrini, Lara

2009-01-01

257

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

International Nuclear Information System (INIS)

Effect of two physical agents: UV- and ?-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 injuradiation protected only from lethal injuries. ?-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

258

Sequence of Two Plasmids from Clostridium perfringens Chicken Necrotic Enteritis Isolates and Comparison with C. perfringens Conjugative Plasmids  

OpenAIRE

Twenty-six isolates of Clostridium perfringens of different MLST types from chickens with necrotic enteritis (NE) (15 netB-positive) or from healthy chickens (6 netB-positive, 5 netB-negative) were found to contain 1–4 large plasmids, with most netB-positive isolates containing 3 large and variably sized plasmids which were more numerous and larger than plasmids in netB-negative isolates. NetB and cpb2 were found on different plasmids consistent with previous studies. The pathogenicity locu...

Parreira, Valeria R.; Costa, Marcio; Eikmeyer, Felix; Blom, Jochen; Prescott, John F.

2012-01-01

259

Involvement of Tn4430 in transfer of Bacillus anthracis plasmids mediated by Bacillus thuringiensis plasmid pXO12.  

OpenAIRE

The self-transmissible plasmid pXO12 (112.5 kilobases [kb]), originally isolated from strain 4042A of Bacillus thuringiensis subsp. thuringiensis, codes for production of the insecticidal crystal protein (Cry+). The mechanism of pXO12-mediated plasmid transfer was investigated by monitoring the cotransfer of the tetracycline resistance plasmid pBC16 (4.2 kb) and the Bacillus anthracis toxin and capsule plasmids, pXO1 (168 kb) and pXO2 (85.6 kb), respectively. In matings of B. anthracis donors...

Green, B. D.; Battisti, L.; Thorne, C. B.

1989-01-01

260

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

OpenAIRE

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...

Maloma, Tsietsi John

2011-01-01

261

Variability of IncHI1 plasmids from Salmonella typhi with special reference to Peruvian plasmids encoding resistance to trimethoprim and other antibiotics.  

OpenAIRE

In spite of extensive DNA homology among IncHI1 plasmids, ApaI and XbaI restriction digests of plasmids from Peruvian Salmonella typhi varied considerably from other IncHI1 plasmids isolated previously. IncHI1 plasmids appear to be undergoing a process of modular evolution, probably by sequential acquisition of resistance determinants.

Taylor, D. E.; Chumpitaz, J. C.; Goldstein, F.

1985-01-01

262

Photon pair spectrometers in a ? ? e? decay search with the MEGA experiment  

International Nuclear Information System (INIS)

The MEGA experiment at LAMPF is conducting a search for the lepton family number violating decay ?+?e+? with a branching ratio sensitivity of a few parts in 10-13. The detectors are contained in a 1.5 T solenoidal magnetic field. Positrons are confined to the central region and are measured by a set of cylindrical MWPCs. Photons are converted into e+e- pairs by one of three pair spectrometers in the outer region. Each pair spectrometer consists of an inner layer of plastic scintillator, two lead converters separated by a MWPC and three layers of drift chambers. The MEGA collaboration successfully concluded 1992 data taking with a set of positron MWPCs and two pair spectrometers. A brief overview of the pair spectrometer design and performance will be followed by a presentation of results to date of the data analysis

263

Hereditary subependymal heterotopia associated with mega cisterna magna: antenatal diagnosis with magnetic resonance imaging.  

Science.gov (United States)

Bilateral nodular subependymal heterotopia has recently been identified as a hereditary disease linked to the X-chromosome. The sonographic findings are very subtle and difficult to observe during the second trimester when the germinal matrix is at its largest. Fetal magnetic resonance imaging facilitates visualization of the periventricular area. We report a case of bilateral nodular heterotopia associated with mega cisterna magna diagnosed by ultrasound and magnetic resonance imaging at 29 weeks' gestation. Magnetic resonance imaging of the brain of the mother revealed similar findings to those observed in the fetus and neonate. This case confirms the association between mega cisterna magna and bilateral periventricular nodular heterotopia and demonstrates that neuroimaging studies of the mother can contribute to the fetal diagnosis. PMID:12100426

Bargalló, N; Puerto, B; De Juan, C; Martinez-Crespo, J M; Lourdes Olondo, M

2002-07-01

264

Results from beam tests of MEGA's low-mass, high-rate cylindrical MWPCs  

International Nuclear Information System (INIS)

One of the leading experimental projects at LAMPF has been the MEGA experiment. This is an experiment to search for the rare decay ? ? e? with a sensitivity of 10-13. A prime component of this project has been the design and construction of high-rate, low mass MWPCs for the tracking of positrons from muon decay. With rate capabilities of 2 x 104 e+/mm2/s and a thickness of 3 x 10-4 radiation lengths, these chambers are state-of-the-art cylindrical MWPCs. Cylindrical chambers of this size (0.9 m2) and thinness have never been previously constructed. The MEGA project at LAMPF has recently succeeded in building chambers with these necessary performance characteristics as demonstrated by data taken from muon decays, cosmic rays, and sources

265

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

OpenAIRE

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. A...

Onyango, Shalotte Salmi

2011-01-01

266

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

OpenAIRE

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...

Mohammad Imam FARISI,

2013-01-01

267

Decision-making on Mega-projects: Drifting on Political Discontinuity and Market Dynamics:  

OpenAIRE

Decision-making on mega-projects is beset by a multitude of problems. Cost overruns and disappointing achievements are already well documented. Some of these pitfalls appear in the initial stages of the decision-making: the absence of an appropriate problem analysis, the lack of alternatives, ambiguities about scope, no programme of functional requirements, flawed process architecture and the dissemination of contested information. But all sorts of uncertainties arise in the long periods b...

Priemus, H.

2010-01-01

268

Air pollution and its impact on human health in mega cities  

International Nuclear Information System (INIS)

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 cn and its impact on human health in mega cities with Karachi as a case study. (author)

269

Research and Development in Hokuto Mega-solar Power Generation System  

Science.gov (United States)

The first stage 600kW Photovoltaic (PV) system of Hokuto Mega-solar project was installed in Yamanashi Prefecture, Japan, in 2006-2007. And the second stage 1,200kW was finished construction considering the result of 1st stage evaluation, and started measuring/evaluating the data The outline and the developing target of the project are introduced and some results provided so far are discussed in this paper.

Konishi, Hiroo

270

Management of juxta articular giant cell tumors around the knee by custom mega prosthetic arthroplasty  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Juxtaarticular giant cell tumors around the knee are common and pose a special problem of reconstruction after tumor excision. This article analyzes the functional outcome after resection of juxtaarticular giant cell tumors around the knee and replacement by custom mega prosthetic arthroplasty. Materials and Methods: One hundred and forty-three patients with juxtaarticular giant cell tumors around the knee with mean age of 30.8 years (range 15 to 64 years underwent resection and replacement by custom mega prosthetic arthroplasty during the period 1994 to 2005. Eighty-one patients were males and 62 were females. Fourteen patients were in Enneking Stage 2 while 129 patients were in Stage 3. Distal femur was involved in 87 patients and proximal tibia in 56 patients. Forty patients presented with pathological fracture at the time of diagnosis. The technique of sleeve resection of the quadriceps musculature was followed to achieve local clearance in distal femoral tumors, and for proximal tibial lesions resection of the tumor-bearing part and a medial gastronemius rotation flap was used routinely. The prosthesis used was a rotating hinge custom mega prosthesis manufactured locally. Results: The mean follow-up was 5.4 years (1.5 years to 11 years. Functional results were analyzed using Enneking criteria. Excellent results were obtained in 90 patients (62% and 39 patients had good (27% results. Periprosthetic fracture (8.3% and infection (6.9% were the most common complications followed by aseptic loosening (4.2%. Recurrence of lesion was found in only one patient (0.69% who was managed with wide local excision. Conclusion: Custom mega prosthetic arthroplasty is effective in achieving the desired goals of reconstruction with good functional results and least complications in selected patients.

Natarajan Mayil

2007-01-01

271

Strategic place marketing and place branding: 15 years of mega-events in Lisbon  

OpenAIRE

Urban tourism is a relatively recent phenomenon but is now being embraced by most European cities, which are using substantial funds to compete for visitors, thus generating new infrastructures for this process. Cities so as to differentiate themselves from their competitors, attempt to manage their image by strategic place marketing approach. This paper explores the implications and significance of being a host city of mega events. The purpose is to identify the perception of Lisbon’s iden...

Metaxas, Theodore; Bati, Aristea; Filippopoulos, Dimitris; Drakos, Kostas; Tzellou, Vagia

2011-01-01

272

Security Governance and Sport Mega-events: Toward an Interdisciplinary Research Agenda  

OpenAIRE

In the post-9/11 context, security issues have become increasingly central to the hosting of sport mega-event (SMEs). Security budgets for events like the Olympic Games now run into billions of dollars. This article seeks to advance the emerging field of SME security research in substantive and analytical terms. We identify three sets of issues and problems that are taking shape within this field: first, comparative issues in relationship to the Global North and Global South, notably given th...

Giulianotti, Richard; Klauser, Francisco

2011-01-01

273

Meteorology and air-quality in a mega-city: application to Tehran, Iran  

OpenAIRE

The influence of a mega-city on the atmospheric boundary layer and surface conditions was examined in the complex-terrain, semi-arid Tehran region using the Pennsylvania State University/National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5) during a high pollution period. In addition, model sensitivity studies were conducted to evaluate the performance of the urban canopy and urban soil model "SM2-U (3D)" parameterization on the meteorological fields and ground level...

Malakooti, Hossein

2010-01-01

274

Wilms' tumor in a case with Möbius' syndrome associated with arthrogryposis and mega cisterna magna.  

Science.gov (United States)

Möbius' syndrome is a rare congenital anomaly characterized by paralysis of the 7th and other cranial nerves and musculoskeletal abnormalities. We report a patient with Möbius' syndrome associated with arthrogryposis and mega cisterna magna in addition to the classic components of this syndrome. The case is interesting because she developed Wilms' tumor at 21 months of age. To our knowledge, this is the first case of this association reported in the literature. PMID:15032390

Yaris, Nilgun; Aynaci, F Müjgan; Kalyoncu, Mukaddes; Odemi?, Ender; Okten, Aysenur

2004-01-01

275

A Case with Mega Cisterna Magna Renal and Ear Anomalies: Is This a New Syndrome?  

OpenAIRE

Background. Extrarenal pathologies may be associated with renal position and fusion anomalies. According to the literature, our patient is the first horseshoe kidney case that had mega cisterna magna, arachnodactyly, and mild mental retardation. Case Report. A 9-year-old boy admitted because of the myoclonic jerks. He had a dysmorphic face, low-set and cup-shaped ears, arachnodactyly, and mild mental retardation. The patient's laboratory findings were normal except for a mild leucocytosis and...

Çapan Konca; Bahar Caliskan; Mehmet Ali Tas

2013-01-01

276

ADAPTION OF “MEGA EVENT IMPACT SCALE”: VALIDITY AND RELIABILITY STUDY (2011 ERZURUM 25. WINTER UNIVERSIADE)  

OpenAIRE

This study aims at carrying out validity and reliability studies and the adaption of Turkish version of the scale titled “Mega Event Impact Scale” and developed by Jie ve Yan (2010). The scale, which consists of five-point Likert scale 42 items, was administered to the local audience following 2011 Erzurum 25. Winter Universiade. The subjects of the study were 412 people (55 % male and 45 % female), who were chosen through random sampling method. Explanatory factor analysis, applied to de...

Kerem Y?ld?r?m ?im?ek

2012-01-01

277

MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony Methods  

OpenAIRE

Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, bio...

Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

2011-01-01

278

MegaRibavirin Aerosol for the Treatment of Influenza A Virus Infections in Mice  

OpenAIRE

While newer neuraminidase inhibitors have been used recently to treat influenza A and B virus infections, emergence of drug resistance poses potential problems. Previous ribavirin aerosol treatments of influenza were effective and drug resistance was not observed. To make ribavirin aerosol treatment a quicker process and limited to once or twice daily treatments, a MegaRibavirin formulation (100 mg of ribavirin/mL) was developed that when used with the Aerotech II nebulizer was effective in p...

Gilbert, Brian E.; Mcleay, Matthew T.

2008-01-01

279

Low-mass, high-rate cylindrical MWPC's for the MEGA experiment  

International Nuclear Information System (INIS)

The construction of MWPCs for the MEGA experiment at LAMPF are described. The chambers are cylindrical, low mass (3 x 10-4 radiation lengths), and are designed to operate at high rates (3 x 104 /mm2/s). Several novel construction techniques have been developed and custom electronics have been designed to help achieve the required performance, which corresponds to that needed at high luminosity colliders. 4 refs., 3 figs

280

[A review of the firefighting techniques used on the tanker 'Mega Borg' explosion  

International Nuclear Information System (INIS)

This paper reviews the events leading up to the explosion and fire of the Mega Borg, a Norwegian tanker which exploded in the Gulf of Mexico in June of 1990. It briefly discusses the fire fighting strategy used to cool the ship prior to foam application and the types of equipment used. It also briefly discusses the lightering operation and the cargo recovery and dewatering operations which took place after the fire was extinguished

281

Interest in plasmids, Herbert BoyerSite: DNA Interactive (www.dnai.org)  

Science.gov (United States)

Interviewee: Herbert Boyer DNAi Location:Manipulation>Revolution>Players>Herbert Boyer and Stanley Cohen>Interest in plasmids Interest in plasmids Herb Boyer talks about Stanley Cohen's and his interest in plasmids as vectors for DNA.

2008-03-26

282

Guidelines for resident teaching experiences.  

Science.gov (United States)

Postgraduate year one (PGY1) and postgraduate year two (PGY2) residencies serve to develop pharmacists into skillful clinicians who provide advanced patient-centered care in various general and specialized areas of pharmacy practice. Pharmacy residencies are a minimum requirement for many clinical pharmacy positions, as well as for positions in academia. The role of clinical pharmacists typically includes teaching, regardless of whether they pursue an academic appointment. Common teaching duties of pharmacist-clinicians include giving continuing education or other invited presentations, providing education to colleagues regarding clinical initiatives, precepting pharmacy students (early and advanced experiences) and residents, and educating other health care professionals. Although ASHP provides accreditation standards for PGY1 and PGY2 residencies, the standards pertaining to teaching or education training are vague. Through the years, teaching certificate programs that develop residents' teaching skills and better prepare residents for a diverse pharmacy job market have increased in popularity; moreover, teaching certificate programs serve as an attractive recruitment tool. However, the consistency of requirements for teaching certificate programs is lacking, and standardization is needed. The Task Force on Residencies developed two sets of guidelines to define teaching experiences within residencies. The first guideline defines the minimum standards for teaching experiences in any residency-training program. The second guideline is for programs offering a teaching certificate program to provide standardization, ensuring similar outcomes and quality on program completion. One of the main differences between the guidelines is the recommendation that residency programs offering a teaching certificate program be affiliated with an academic institution to provide the pedagogy and variety of teaching experiences for the resident. Residency program directors should consider adopting these guidelines to offer consistent teaching experiences. In addition, residents should inquire about the elements of teaching in a program as an aid to selecting the training best suited to their needs. PMID:23401039

Havrda, Dawn E; Engle, Janet P; Anderson, Keri C; Ray, Shaunta' M; Haines, Seena L; Kane-Gill, Sandra L; Ballard, Stephanie L; Crannage, Andrew J; Rochester, Charmaine D; Parman, Malinda G

2013-07-01

283

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

Directory of Open Access Journals (Sweden)

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.

Hyo Seon Park

2013-05-01

284

Mega-impacts and mantle-melting episodes: tests of possible correlations  

International Nuclear Information System (INIS)

The criteria for recognising the effects of impacts by large-diameter extraterrestrial projectiles (Dp>>10 km) on thin, geothermally active crust must vary fundamentally from those pertaining to impacts on thick, cooler continental crust. Although the bulk of the terrestrial cratering records has been destroyed by both erosion of elevated terrains and plate subduction, or obscured by burial, a search for Precambrian mega-impacts is facilitated by the preservation of their likely secondary effects: mega-earthquake-triggered faults; ensuing diamictites, and the deposits of turbidity currents; microtektites; spherulitic condensates of vaporised asteroid and target materials; and distal tectonic and igeneous effects. Clues to the origin of thermal events are provided by peaks on isotopic-age histograms of precise U-Pb, Ar-Ar, amd Sm-Nd mineral-whole-rock ages. These peaks, spatially corroborated by detailed mapping of Precambrian terrains, support an episodic nature of at least certain major Precambrian events and some correlations with impact events. Preliminary time-series analyses of Precambrian events yield values consistent with the Phanerozoic galactic rotation period (250 ± 50 Ma), and the solar system's cross-galactic-plane oscillation period (33 ± 3 Ma). It has been demonstrated that possible correlations between mega-impacts and tectonic/thermal events are capable of being tested through isotopic-age studies of diamictites and spherule units of impaf diamictites and spherule units of impact origin and of rifting and mafic igneous events. 123 refs., 2 tabs., 7 figs

285

Solubilization of n-alkylbenzenes into decanoyl-N-methylglucamide (Mega-10) solution.  

Science.gov (United States)

Solubilization of benzene, toluene, ethylbenzene, n-propylbenzene, n-butylbenzene, n-pentylbenzene, and n-hexylbenzene into micelles of decanoyl-N-methylglucamide (Mega-10) was studied, where equilibrium concentrations of the above solubilizates were determined spectrophotometrically at 303.2 K. The concentration of the above solubilizates remained constant below the critical micelle concentration (cmc) and increased linearly with an increase in Mega-10 concentration above the cmc. The Gibbs free energy change of the solubilizates from the aqueous bulk to the liquid solubilizate phase was evaluated from the dependence of their aqueous solubility on the alkyl chain length of the solubilizates, which leads to -3.46 kJ mol-1 for DeltaG(0)(CH), the energy change per CH2 group of the alkyl chain. The first stepwise solubilization constant (K(overline)1 ) was evaluated from the slope of the change of solubilizate concentration versus Mega-10 concentration. The Gibbs free energy change (DeltaG(0,s)) for the solubilization decreased linearly with the carbon number of the alkyl chain of the solubilizates, from which DeltaG(0,s)(CH2) as evaluated to be -2.71 kJ mol-1. The similar values above clearly indicate that the location of the alkyl chain is a hydrophobic micellar core, which is also supported by the absorption spectrum of the solubilized molecules. PMID:18052401

Nakamura, Shohei; Kobayashi, Lisa; Tanaka, Ryo; Isoda-Yamashita, Teruyo; Motomura, Konomi; Moroi, Yoshikiyo

2008-01-01

286

NATURAL TRANSFORMATION OF A MARINE VIBRIO SPECIES BY PLASMID DNA  

Science.gov (United States)

A series of thirty marine and estuarine bacterial isolates was examined for the ability to naturally transform with plasmid DNA. One isolate from Tampa Bay, Florida, identified as Vibrio parahaemolyticus, successfully incorporated and maintained the broad host range plasmid pKT23...

287

Broad host range of streptococcal macrolide resistance plasmids.  

OpenAIRE

Four macrolide-lincosamide-streptogramin B resistance plasmids transferred into 13 recipients belonging to Streptococcus, Staphylococcus, and Listeria genera. The plasmids were stably maintained in all new hosts except Streptococcus sanguis, Streptococcus pneumoniae, Staphylococcus aureus, and Listeria innocua and were identical to those found in the corresponding donor strains.

Buu-hoi?, A.; Bieth, G.; Horaud, T.

1984-01-01

288

Replication and maintenance of plasmids in Bacillus subtilis  

OpenAIRE

Plasmids and their derived gene cloning and expression vectors play a prominent role in almost all area's of molecular genetics. A disadvantage, however, is the frequently observed high level of instability of plasmids, especially when they contain heterologous DNA. Two types of instability can be distinguished: structural and segregational instability. ... Zie: Chapter 10

Meijer, Wilhelmus Johannes Jozef

1995-01-01

289

Plasmid-encoded copper resistance and precipitation by Mycobacterium scrofulaceum.  

OpenAIRE

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.

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

1987-01-01

290

Transformation of Bacillus subtilis by single-stranded plasmid DNA.  

OpenAIRE

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.

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

1986-01-01

291

[Plasmids of Bacillus thuringiensis var. galleriae strain 612].  

Science.gov (United States)

We studied Bacillus thuringiensis var galleriae, strain 612 plasmids. B. thuringiensis cells contain double-stranded plasmid DNA molecules (ranging of about 12% from total DNA content) with buoyant density 1.59 g/cm3. Plasmid DNA content was constant during the exponential and stationary phases of bacterial growth. The plasmid fractions consist of DNA molecules with molecular weights of 5.9 x 10(6), 10.0 x 10(6), and 110.9 x 10(6) daltons (pVD1, pVD2 pVD3, respectively). Endonuclease EcoRI cuts the plasmids pVD2 and pVD3 into two and four fragments, respectivelyy, but pVDI seemed to be resistent to EcoRI treatment. We found that pVD2 and pVD3 plasmids contain a common DNA fragment with the molecular weight of 6.7 x 10(6) dalton as it was shown by restriction analysis. In contrast, the same plasmids contain the common fragment with molecular weight of 7.5 x 10(6) dalton as shown by heteroduplex analysis. Plasmid pVD3 has a transposon-like structure. PMID:6252447

Debabov, V G; Khlebalina, O I; Galushka, F P; Sladkova, I A

1980-01-01

292

Autonomous cytoplasmic linear plasmid pPac1-1 of Pichia acaciae: molecular structure and expression studies.  

Science.gov (United States)

The genome organization of the linear DNA-element pPac1-1 from Pichia acaciae was determined. It turned out to be the smallest autonomous cytoplasmic yeast plasmid known so far, consisting of only 12 646 bp, carrying the shortest terminal inverted repeats yet found (138 bp). As for other cytoplasmic linear yeast plasmids, it is characterized by a strikingly high A + T content (75.35%). Ten putative genes (open reading frames, ORFs) reside on the element, leaving only 2.9% of the sequence outside a coding region. Highest similarities of the predicted proteins were obtained for proteins encoded by the three hitherto known autonomous cytoplasmic linear yeast plasmids. Amino acid sequences correspond to predicted polypeptides encoded by ORFs 2-11 of the linear plasmids pGKL2 of Kluyveromyces lactis, pSKL of Saccharomyces kluyveri and pPE1B of Pichia etchellsii. As for the latter, ORF1 existing on the two other plasmids is lacking on pPac1-1. Consistent with cytoplasmic localization, a cytoplasmic promoter termed upstream conserved sequence (UCS) is located in front of each reading frame. RT-PCR transcript analyses for ORFs 8, 9 and 11 proved expression of such genes but functions could not be attributed. The genome organization of pPac1-1 and other autonomous linear elements was found to be almost congruent, irrespective of the accompanying smaller elements, which may or may not encode their own element-specific DNA polymerases. PMID:16652393

Jeske, Stefanie; Meinhardt, Friedhelm

2006-04-30

293

Construction and application of an expression vector from the new plasmid pLAtc1 of Acidithiobacillus caldus.  

Science.gov (United States)

In this study, a recently sequenced 9.8-kb plasmid, pLAtc1, from Acidithiobacillus caldus strain SM-1 was characterized and developed into an expression vector. The pLAtc1 backbone carried an oriV, three rep genes, five mob genes, a Nic site, and an addiction system. Multilocus sequence analysis indicated that pLAtc1 was phylogenetically more related to the IncQ-like broad host range plasmids than to other IncQ plasmids. pLAtc1 was able to replicate and reside in Gram-negative Escherichia coli, Comamonas testosteroni, but not in Gram-positive Corynebacterium glutamicum. pLAtc1 was mobilized via conjugation into E. coli BL21 and A. caldus SM-1 from E. coli S17-1. Quantitative PCR revealed seven and four copies of plasmid in A. caldus and E. coli cells, respectively. The expression vector pLAtcE was constructed from pLAtc1 by introducing a regulatable promoter (P tetH ), a transcriptional terminator, a multiple cloning site, a kanamycin resistance gene, and a streptomycin resistance gene. The functionality of pLAtcE was demonstrated by expressing a gene encoding enhanced green fluorescence protein in E. coli and in A. caldus. pLAtcE was used to express ?-ketoglutarate dehydrogenase (sucAB) and succinate dehydrogenase (sdhA) genes in A. caldus. The newly engineered strain that harbored sucAB and sdhA on a plasmid pLAtcE-sucA-sucB-sdhA grew better than the parent strain SM-1/pLAtcE in tetrathionate and glucose-supplemented medium and produced more acidity and resulted in a more oxidative environment. This study created a useful molecular tool for genetic manipulation of the thermoacidophilic and autotrophic A. caldus. PMID:24445921

Zhang, Ming-Jiang; Jiang, Cheng-Ying; You, Xiao-Yan; Liu, Shuang-Jiang

2014-05-01

294

Phage type conversion in Salmonella enterica serotype Enteritidis caused by the introduction of a resistance plasmid of incompatibility group X (IncX)  

DEFF Research Database (Denmark)

The plasmid pOG670, a 54 kb, conjugative plasmid that specifies resistance to ampicillin and kanamycin and belonging to the incompatibility group X (IncX), was transferred into 10 isolates of Salmonella enterica serotype Enteritidis belonging to 10 different phage types (PT1, 2, 3, 4, 8, 9, 9b, 10, 11 and 13). Acquisition of the plasmid by these strains did not result in the loss of any resident plasmids but resulted in phage type conversion in 8 of the 10 strains (PT1, 2, 4, 8, 9, 9b, 10 and 11). The observed changes in phage type were found to result from the loss of sensitivity to 3 of the 10 typing phages used (phages 3, 5 and 7). Where the conversion resulted in a change to a defined phage type, both the new and original PTs belonged to the same, previously described, evolutionary lines. Enteritidis PTs 1, 4 and 8, commonly associated with poultry world-wide, were converted to PTs 21, 6 and 13a respectively. The results indicate a different route for phage type conversion Enteritidis from others reportedin the literature and, although IncX plasmids are not normally present in PT8 or PT13a, may suggest a possible mechanism/link connecting these phage types.

Brown, D. J.; Baggesen, Dorte Lau

1999-01-01

295

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

OpenAIRE

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 2?m circle—a multicopy plasmid that resides in the yeast nucleus and propagates itself stably. Cse4 is essential for the functional assem...

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

2010-01-01

296

Plasmid-mediated UV-protection in Myxococcus xanthus  

International Nuclear Information System (INIS)

Plasmid R 46 was successfully transferred from Escherichia coli K-12 into Myxococcus xanthus strain MD-1 but not into M. xanthus strain XK. Plasmid R 68.45 was transferred from E. coli K-12 into both strains of M. xanthus. The effects of these plasmids on survival of M. xanthus after ultraviolet (UV) - 254 nm irradiation, the ability of M. xanthus to reactivate irradiated myxophages, and Weigle reactivation of UV-irradiated myxophages by M. xanthus were studied. Plasmid R 46 had no effect on UV survival of M. xanthus, but increased the host's ability to reactivate irradiated myxophages. Plasmid R 68.45 protected M. xanthus strains MD-1 and XK against the lethal effects of UV irradiation and also increased the host's ability to reactivate irradiated myxophages. (orig.)

297

Characterization of a plasmid from moderately halophilic eubacteria.  

Science.gov (United States)

A plasmid has been isolated for the first time from moderately halophilic eubacteria. Halomonas elongata, Halomonas halmophila, Deleya halophila and Vibrio costicola were found to harbour an 11.5 kbp plasmid (pMH1). The plasmid was isolated and characterized after transformation into Escherichia coli 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 confirmed by Southern hybridization. The plasmid carries genetic determinants that mediate resistance to kanamycin, tetracycline, and neomycin. This property, together with its relatively small size, its stability in E. coli cells, and the presence of unique restriction sites, makes pMH1 a good candidate for the development of a cloning vector for moderate halophiles. PMID:1527492

Fernandez-Castillo, R; Vargas, C; Nieto, J J; Ventosa, A; Ruiz-Berraquero, F

1992-06-01

298

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

OpenAIRE

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...

Taxis Du Poe?t, P.; Arcand, Y.; Bernier, R.; Barbotin, J. N.; Thomas, D.

1987-01-01

299

Incorporating resident research into the dermatology residency program  

Directory of Open Access Journals (Sweden)

Full Text Available Richard F Wagner Jr, Sharon S Raimer, Brent C Kelly Department of Dermatology, The University of Texas Medical Branch, Galveston, Texas, USA Abstract: Programmatic changes for the dermatology residency program at The University of Texas Medical Branch were first introduced in 2005, with the faculty goal incorporating formal dermatology research projects into the 3-year postgraduate training period. This curriculum initially developed as a recommendation for voluntary scholarly project activity by residents, but it evolved into a program requirement for all residents in 2009. Departmental support for this activity includes assignment of a faculty mentor with similar interest about the research topic, financial support from the department for needed supplies, materials, and statistical consultation with the Office of Biostatistics for study design and data analysis, a 2-week elective that provides protected time from clinical activities for the purpose of preparing research for publication and submission to a peer-reviewed medical journal, and a departmental award in recognition for the best resident scholarly project each year. Since the inception of this program, five classes have graduated a total of 16 residents. Ten residents submitted their research studies for peer review and published their scholarly projects in seven dermatology journals through the current academic year. These articles included three prospective investigations, three surveys, one article related to dermatology education, one retrospective chart review, one case series, and one article about dermatopathology. An additional article from a 2012 graduate about dermatology education has also been submitted to a journal. This new program for residents was adapted from our historically successful Dermatology Honors Research Program for medical students at The University of Texas Medical Branch. Our experience with this academic initiative to promote dermatology research by residents is outlined. It is recommended that additional residency programs should consider adopting similar research programs to enrich resident education. Keywords: dermatology, resident, research, education, accreditation

Wagner RF Jr

2013-04-01

300

Machiavelli and the chief resident.  

Science.gov (United States)

A good chief resident is under pressure from residents and the department director and must work for the welfare of both the housestaff and the institution. Using precepts from Niccoló Machiavelli's The Prince, the author gives advice for chief residents on how to balance their responsibilities. The author, using Machiavelli's precepts, discusses the difficulties of introducing change, supervising former colleagues and peers, the opprobrium that inevitably attaches to tough decisions, the need to set good examples, and other aspects of being a chief resident. PMID:2372343

Raviglione, M C

1990-06-01

301

Complete nucleotide sequence and organization of the atrazine catabolic plasmid pADP-1 from Pseudomonas sp. strain ADP.  

Science.gov (United States)

The complete 108,845-nucleotide sequence of catabolic plasmid pADP-1 from Pseudomonas sp. strain ADP was determined. Plasmid pADP-1 was previously shown to encode AtzA, AtzB, and AtzC, which catalyze the sequential hydrolytic removal of s-triazine ring substituents from the herbicide atrazine to yield cyanuric acid. Computational analyses indicated that pADP-1 encodes 104 putative open reading frames (ORFs), which are predicted to function in catabolism, transposition, and plasmid maintenance, transfer, and replication. Regions encoding transfer and replication functions of pADP-1 had 80 to 100% amino acid sequence identity to pR751, an IncPbeta plasmid previously isolated from Enterobacter aerogenes. pADP-1 was shown to contain a functional mercury resistance operon with 99% identity to Tn5053. Complete copies of transposases with 99% amino acid sequence identity to TnpA from IS1071 and TnpA from Pseudomonas pseudoalcaligenes were identified and flank each of the atzA, atzB, and atzC genes, forming structures resembling nested catabolic transposons. Functional analyses identified three new catabolic genes, atzD, atzE, and atzF, which participate in atrazine catabolism. Crude extracts from Escherichia coli expressing AtzD hydrolyzed cyanuric acid to biuret. AtzD showed 58% amino acid sequence identity to TrzD, a cyanuric acid amidohydrolase, from Pseudomonas sp. strain NRRLB-12227. Two other genes encoding the further catabolism of cyanuric acid, atzE and atzF, reside in a contiguous cluster adjacent to a potential LysR-type transcriptional regulator. E. coli strains bearing atzE and atzF were shown to encode a biuret hydrolase and allophanate hydrolase, respectively. atzDEF are cotranscribed. AtzE and AtzF are members of a common amidase protein family. These data reveal the complete structure of a catabolic plasmid and show that the atrazine catabolic genes are dispersed on three disparate regions of the plasmid. These results begin to provide insight into how plasmids are structured, and thus evolve, to encode the catabolism of compounds recently added to the biosphere. PMID:11544232

Martinez, B; Tomkins, J; Wackett, L P; Wing, R; Sadowsky, M J

2001-10-01

302

Measurement of residence times and residence-time distributions  

International Nuclear Information System (INIS)

In this chapter the use of radioisotopes for the measurement of residence-times with particular reference to vessel failure in the chemical industry is discussed. Ideal and non-ideal flow models and the more important parameters of models are discussed. Examples are given of the effect of process malfunction on residence times. (U.K.)

303

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

Directory of Open Access Journals (Sweden)

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 qualified staff and increases the burden on residents may be reassigned to medical secretary or pathology assistants; therefore energy of residents can be saved for educational activities. Optimization of physical working conditions, assortment of training programs, rotation in lacking subjects and consultations will enhance the quality of the education of the resident. Feedback assessment of trainer and trainee is an essential part of a training program.In conclusion, an ideal resident from the resident's point of view is the person who is endowed with medical and pathological knowledge, orderly interrelates with staff, professionally communicates with clinicians, manages a laboratory and is trained hard to achieve all the above mentioned competencies.

Kemal KÖSEMEHMETO?LU

2008-01-01

304

Establishment of a Replicating Plasmid in Rickettsia prowazekii  

Science.gov (United States)

Rickettsia prowazekii, the causative agent of epidemic typhus, grows only within the cytosol of eukaryotic host cells. This obligate intracellular lifestyle has restricted the genetic analysis of this pathogen and critical tools, such as replicating plasmid vectors, have not been developed for this species. Although replicating plasmids have not been reported in R. prowazekii, the existence of well-characterized plasmids in several less pathogenic rickettsial species provides an opportunity to expand the genetic systems available for the study of this human pathogen. Competent R. prowazekii were transformed with pRAM18dRGA, a 10.3 kb vector derived from pRAM18 of R. amblyommii. A plasmid-containing population of R. prowazekii was obtained following growth under antibiotic selection, and the rickettsial plasmid was maintained extrachromosomally throughout multiple passages. The transformant population exhibited a generation time comparable to that of the wild type strain with a copy number of approximately 1 plasmid per rickettsia. These results demonstrate for the first time that a plasmid can be maintained in R. prowazekii, providing an important genetic tool for the study of this obligate intracellular pathogen. PMID:22529927

Wood, David O.; Hines, Andria; Tucker, Aimee M.; Woodard, Andrew; Driskell, Lonnie O.; Burkhardt, Nicole Y.; Kurtti, Timothy J.; Baldridge, Gerald D.; Munderloh, Ulrike G.

2012-01-01

305

Antibiotic resistance plasmids of Staphylococcus aureus and their clinical importance  

International Nuclear Information System (INIS)

A variety of plasmids were isolated physically, and most antibiotic resistance is thought to be plasmid mediated. A number of characters (e.g., resistance to erythromycin or methicillin, and production of pigment) are determined by genes that do not give clear indications of either plasmid or chromosomal location. Although the formation of a particular plasmid is probably, even in bacterial terms, a very rare event, once formed such an element can spread rapidly among the bacterial population. The spectacular increase in the incidence of penicillinase-producing hospital strains in the late 1940's could have been due in part to this process. Evidence is stronger, however, for the intercell transfer of recently isolated plasmids coding for resistance to fusidic acid (and penicillinase production), or for neomycin, or for tetracycline resistance. Study of bacterial plasmids can resolve fundamental biochemical problems, and give some insight into the life of the cell at the molecular level. But the immediate application of the study of staphylococcal plasmids may be directed towards improving the effectiveness of antibiotic therapy. The most important aspect of future anti-staphylococcal chemotherapy should thus be the limitation of the use of antibiotics, particularly for application to the skin and nose. (U.S.)

306

Plasmid incidence in bacteria from deep subsurface sediments.  

Science.gov (United States)

Bacteria were isolated from deep terrestrial subsurface sediments underlying the coastal plain of South Carolina. A total of 163 isolates from deep sediments, surface soil, and return drill muds were examined for plasmid DNA content and resistance to the antibiotics penicillin, ampicillin, carbenicillin, streptomycin, kanamycin, and tetracycline. MICs of Cu, Cr, and Hg for each isolate were also determined. The overall frequency of plasmid occurrence in the subsurface bacteria was 33%. Resistance was most frequent to penicillin (70% of all isolates), ampicillin (49%), and carbenicillin (32%) and was concluded to be related to the concentrations of the individual antibiotics in the disks used for assaying resistance and to the production of low levels of beta-lactamase. The frequencies of resistance to penicillin and ampicillin were significantly greater for isolates bearing plasmids than for plasmidless isolates; however, resistance was not transferable to penicillin-sensitive Escherichia coli. Hybridization of subsurface bacterial plasmids and chromosomal DNA with a whole-TOL-plasmid (pWWO) probe revealed some homology of subsurface bacterial plasmid and chromosomal DNAs, indicating a potential for those bacteria to harbor catabolic genes on plasmids or chromosomes. The incidences of antibiotic resistance and MICs of metals for subsurface bacteria were significantly different from those for drill mud bacteria, ruling out the possibility that bacteria from sediments were derived from drill muds. PMID:16347789

Fredrickson, J K; Hicks, R J; Li, S W; Brockman, F J

1988-12-01

307

Plasmid-associated sensitivity of Bacillus thuringiensis to UV light  

Energy Technology Data Exchange (ETDEWEB)

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.

Benoit, T.G.; Wilson, G.R.; Bull, D.L.; Aronson, A.I. (Department of Agriculture, College Station, TX (USA))

1990-08-01

308

Plasmid-associated sensitivity of Bacillus thuringiensis to UV light  

International Nuclear Information System (INIS)

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

309

Multiple enzymatic activities of ParB/Srx superfamily mediate sexual conflict among conjugative plasmids.  

Science.gov (United States)

Conjugative plasmids are typically locked in intergenomic and sexual conflicts with co-resident rivals, whose translocation they block using fertility inhibition factors (FINs). We describe here the first crystal structure of an enigmatic FIN Osa deployed by the proteobacterial plasmid pSa. Osa contains a catalytically active version of the ParB/Sulfiredoxin fold with both ATPase and DNase activity, the latter being regulated by an ATP-dependent switch. Using the Agrobacterium tumefaciens VirB/D4 type IV secretion system (T4SS), a relative of the conjugative T4SS, we demonstrate that catalytically active Osa blocks T-DNA transfer into plants. With a partially reconstituted T4SS in vitro, we show that Osa degrades T-DNA in the T-DNA-VirD2 complex before its translocation. Further, we present evidence for conservation and interplay between ATPase and DNase activities throughout the ParB/Sulfiredoxin fold, using other members of the family, namely P1 ParB and RK2 KorB, which have general functional implications across diverse biological contexts. PMID:25358815

Maindola, Priyank; Raina, Rahul; Goyal, Parveen; Atmakuri, Krishnamohan; Ojha, Abhishek; Gupta, Sourabh; Christie, Peter J; Iyer, Lakshminarayan M; Aravind, L; Arockiasamy, Arulandu

2014-01-01

310

Relevance of the Residence Requirement.  

Science.gov (United States)

With the changes in undergraduate education and the growth of community colleges, the concept of the continuous residence requirement for the baccalaureate degree may be going out of style. There is also increasing demand for changes in residence requirements at the master's level, because many of those pursuing this degree hold full-time jobs.…

Alpert, Daniel

311

Low-level infrared laser effect on plasmid DNA.  

Science.gov (United States)

Low-level laser therapy is used in the treatment of many diseases based on its biostimulative effect. However, the photobiological basis for its mechanism of action and adverse effects are not well understood. The aim of this study, using experimental models, was to evaluate the effects of laser on bacterial plasmids in alkaline agarose gel electrophoresis and Escherichia coli cultures. The electrophoretic profile of bacterial plasmids in alkaline agarose gels were used for studying lesions in DNA exposed to infrared laser. Transformation efficiency and survival of Escherichia coli AB1157 (wild-type), BH20 (fpg/mutM(-)), BW9091 (xth(-)), and DH5?F'Iq (recA(-)) cells harboring pBSK plasmids were used as experimental models to assess the effect of laser on plasmid DNA outside and inside of cells. Data indicate low-level laser: (1) altered the electrophoretic profile of plasmids in alkaline gels at 2,500-Hz pulsed-emission mode but did not alter at continuous wave, 2.5- and 250-Hz pulsed-emission mode; (2) altered the transformation efficiency of plasmids in wild-type and fpg/mutM(-) E. coli cells; (3) altered the survival fpg/mutM(-), xthA(-) and recA(-) E. coli cultures harboring pBSK plasmids. Low-level infrared laser with therapeutic fluencies at high frequency in pulsed-emission modes have effects on bacterial plasmids. Infrared laser action can differently affect the survival of plasmids in E. coli cells proficient and deficient in DNA repair mechanisms, therefore, laser therapy protocol should take into account fluencies, frequencies and wavelength of laser, as well as tissue conditions and genetic characteristics of cells before beginning treatment. PMID:21556926

Fonseca, Adenilson Souza; Geller, Mauro; Bernardo Filho, Mario; Valença, Samuel Santos; de Paoli, Flavia

2012-01-01

312

Plasmid genes required for microcin B17 production.  

OpenAIRE

The production of the antibiotic substance microcin B17 (Mcc) is determined by a 3.5-kilobase DNA fragment from plasmid pMccB17. Several Mcc- mutations on plasmid pMccB17 were obtained by both transposon insertion and nitrosoguanidine mutagenesis. Plasmids carrying these mutations were tested for their ability to complement Mcc- insertion or deletion mutations on pMM102 (pMM102 is a pBR322 derivative carrying the region encoding microcin B17). Results from these experiments indicate that at l...

San Milla?n, J. L.; Kolter, R.; Moreno, F.

1985-01-01

313

Effect of Plasmid Incompatibility on DNA Transfer to Streptococcus cremoris  

OpenAIRE

Several Streptococcus cremoris strains were used in protoplast transformation and interspecific protoplast fusion experiments with Streptococcus lactis and Bacillus subtilis, with pGKV110, pGKV21, and ?pAM?1 as the marker plasmids. ?pAM?1 is a 15.9-kilobase nonconjugative, deletion derivative of pAM?1, which is considerably larger than the pGKV plasmids (approximately 4.5 kilobases). In general, ?pAM?1 was transferred more efficiently than the pGKV plasmids. Using electroporation, we w...

Lelie, Daniel; Vossen, Jos M. B. M.; Venema, Gerard

1988-01-01

314

Early resident-to-resident physics education in diagnostic radiology.  

Science.gov (United States)

The revised ABR board certification process has updated the method by which diagnostic radiology residents are evaluated for competency in clinical radiologic physics. In this work, the author reports the successful design and implementation of a resident-taught physics course consisting of 5 weekly, hour-long lectures intended for incoming first-year radiology residents in their first month of training. To the author's knowledge, this is the first description of a course designed to provide a very early framework for ongoing physics education throughout residency without increasing the didactic burden on faculty members. Twenty-six first-year residents spanning 2 academic years took the course and reported subjective improvement in their knowledge (90%) and interest (75%) in imaging physics and a high level of satisfaction with the use of senior residents as physics educators. Based on the success of this course and the minimal resources required for implementation, this work may serve as a blueprint for other radiology residency programs seeking to develop revised physics curricula. PMID:24139318

Kansagra, Akash P

2014-01-01

315

Sport mega-events: can legacies and development be equitable and sustainable? / Mega-eventos esportivos: podem desenvolvimento e legado ser equalitários e sustentáveis? / Sport mega-eventos: pueden ser legados y el desarrollo equitativo y sostenible?  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Os mega-eventos esportivos (MEE) envolvem lutas para se determinar a definição de legado e as prioridades que guiam os processos de planejamento, financiamento e processos de implementação de resultados. A história mostra que os legados refletem os interesses do capital, e os benefícios são usufruid [...] os principalmente, se não exclusivamente, por interesses empresariais poderosos, por alguns líderes políticos e por organizações que governam o esporte de alto rendimento. Este artigo aborda os desafios enfrentados pelas cidades e países que hospedam MEE e demonstra que legados justos e equalitários e resultados em termos de desenvolvimento são alcançados somente quando as vozes e os interesses da população em geral são ouvidos e considerados como prioridade durante o processo de planejamento, financiamento e implementação. Ele também demonstra que a representação plena no processo de definição e prossecução de legados e a consecução de resultados em termos de desenvolvimento podem ser prejudicados por crenças populares sobre o poder do esporte. Abstract in spanish Los mega-eventos deportivos (DME) implican luchas para determinar la definición del legado y las prioridades que guían los procesos de planificación, financiación financiamiento y ejecución de los resultados. La historia muestra que los legados reflejan los intereses del capital y que los beneficios [...] son disfrutados principalmente, si no exclusivamente por los intereses empresariales poderosos, por algunos líderes políticos y por las organizaciones que dirigen los deportes de alto rendimiento. Este artículo aborda los desafíos que enfrentan las ciudades y los países anfitriones de los DME, y demuestra que legados justos y equitativos y resultados en sentido de desarrollo se logran solamente cuando se considera y se da prioridad a las voces e intereses de la población en general durante el proceso de planificación, financiamiento e implementación. Él también demuestra que la representación plena en el proceso de definición y consecución de los legados y los resultados en sentido de desarrollo pueden ser socavadas por las creencias populares sobre el poder del deporte. Abstract in english 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 shows that fair and equitable legacies and developmental outcomes are achieved only when the voices and interests of the general population are taken into account and given priority during the process of planning, funding and implementation. It also explains how full representation in the process of defining and achieving legacies and developmental outcomes may be undermined by populist beliefs about the power of sport.

Jay, Coakley; Doralice Lange, Souza.

2013-09-01

316

A model of competition between plasmid-bearing and plasmid-free organisms in a chemostat with periodic input  

International Nuclear Information System (INIS)

In this paper, we present and analyze a simple model for a chemostat with plasmid-bearing and plasmid-free organisms and periodically pulsed substrate. We obtain an exact periodic solution with positive concentrations of substrate and plasmid-free organism, and furthermore, we prove that the periodic solution is stable if the impulsive period is more than some critical value and meanwhile we prove that system is permanent if the impulsive period is less than some critical value. Finally, we give a brief discussion and find that periodically pulsed input destroys the equilibria of the unforced continuous system

317

Plasmid- and chromosome-coded aerobactin synthesis in enteric bacteria: insertion sequences flank operon in plasmid-mediated systems.  

OpenAIRE

Large plasmids were detected in two aerobactin-producing enteric bacterial species (Aerobacter aerogenes 62-I, Salmonella arizona SA1, and S. arizona SL5301) and designated pSMN1, pSMN2, and pSMN3, respectively. Other Salmonella spp., namely, S. arizona SL5302, S. arizona SLS, Salmonella austin, and Salmonella memphis, formed aerobactin but contained no detectable large plasmids. S. arizona SL5283 made no aerobactin. A probe consisting of the aerobactin biosynthetic genes cloned on plasmid pA...

Mcdougall, S.; Neilands, J. B.

1984-01-01

318

Solubilization of n-alkylbenzenes into decanoyl-N-methylglucamide (Mega-10) solution; temperature dependence.  

Science.gov (United States)

Solubilization of benzene, toluene, ethylbenzene, n-propylbenzene, n-butylbenzene, n-pentylbenzene, and n-hexylbenzene into micelles of decanoyl-N-methylglucamide (Mega-10) was studied at 303.2, 308.2, 313.2, and 318.2K, where equilibrium concentrations of the above solubilizates were determined spectrophotometrically. The concentration of the above solubilizates remained constant below the critical micelle concentration (cmc) and increased linearly with an increase in Mega-10 concentration above the cmc at each temperature above. The Gibbs free energy change of the solubilizates from aqueous bulk to their liquid solubilizate phase was evaluated from dependence of their aqueous solubility on alkyl chain length of the solubilizates, which leads to the DeltaG(CH0)(2) values (-3.60 to -3.38 kJ mol(-1)), the energy change per CH2 group of the alkyl chain with no strong temperature dependence. The first stepwise solubilization constant (K1) was evaluated from the slope for the change of solubilizate concentration vs. Mega-10 concentration. The Gibbs free energy change (DeltaG(0,s)) for the solubilization decreased linearly with the carbon number of alkyl chain of the solubilizates, and the DeltaG(CH0)(2)(s) values (-2.71 to -2.54 kJ mol(-1)) obtained from the linearity showed a slight increase with temperature. The DeltaG(CH0)(2) values are less than the DeltaG(CH0)(2)(s) values, where the latter values clearly indicate that the location of alkyl chain is a hydrophobic micellar core. The fact is also supported by the absorption spectrum of the solubilized molecules. Temperature dependence of DeltaG(0,s) indicated that the solubilization is entropy-driven for the solubilizates with shorter alkyl chains, while it becomes enthalpy-driven for those with longer alkyl chains. PMID:19150232

Nakamura, Shohei; Kobayashi, Lisa; Tanaka, Ryo; Isoda-Yamashita, Teruyo; Lee, Jungno; Moroi, Yoshikiyo

2009-02-15

319

The role of mega dams in reducing sediment fluxes: A case study of large Asian rivers  

Science.gov (United States)

SummaryIn order to sustain the ever growing population and to meet water and energy requirements of the rapidly growing economies, most of the large rivers draining through East, Southern and Southeast (ESSE) Asian region have been regulated all along their courses, over the past few decades. For instance, ESSE Asian countries (China, Taiwan, Vietnam, Myanmar, Thailand, India, Pakistan and Bangladesh) host about 250 mega dams and several tens of thousands of large and small reservoirs. The present study provides a revised estimate on annual suspended sediment fluxes of the large rivers draining through ESSE region, including the latest data of the Indian peninsula rivers. In the last 50 years, the combined annual sediment flux of the large Chinese rivers has been reduced from 1800 million tons (Mt) to about 370 Mt. We estimate that at present the Indian peninsular rivers collectively transport about 83 Mt of sediment annually. The Ganga-Brahmaputra and the Indus, contribute 850 and 13 Mt of sediments, respectively to the oceans. Our revised estimates suggest that at present the large rivers of ESSE region, collectively delivering ?2150 Mt of sediment annually to the oceans. We show that at decadal scale, decline in sediment fluxes of the large Asian rivers are proportional to the number of mega dams present in the respective catchments. We also demonstrate that storage of sediment-laden water of major flood events (major-event), led to huge sediment trapping behind mega dams. Thus, ongoing and planned dam constructions activities across ESSE Asia may further reduce the annual sediment fluxes.

Gupta, Harish; Kao, Shuh-Ji; Dai, Minhan

2012-09-01

320

Seismic Regime in the Vicinity of the 2011 Tohoku Mega Earthquake (Japan, M w = 9)  

Science.gov (United States)

The 2011 Tohoku mega earthquake ( M w = 9) is unique due to a combination of its large magnitude and the high level of detail of regional seismic data. The authors analyzed the seismic regime in the vicinity of this event using data from the Japan Meteorological Agency catalog and world databases. It was shown that a regional decrease in b-value and of the number of main shocks took place in the 6-7 years prior to the Tohoku mega earthquake. The space-time area of such changes coincided with the development of precursor effects in this area, as revealed by Lyubushin (Geofiz Prots Biosfera 10:9-35, 2011) from the analysis of microseisms recorded by the broadband seismic network F-net in Japan. The combination of episodes of growth in the number of earthquakes, accompanied by a corresponding decrease in the b-value and average depth of the earthquakes, was observed for the foreshock and aftershock sequences of the 2011 Tohoku earthquake. Some of these anomalies were similar to those observed (also post factum) by Katsumata (Earth Planets Space 63:709-712, 2011), Nanjo et al. (Geophys Res Lett 39, 2012), and Huang and Ding (Bull Seismol Soc Am 102:1878-1883, 2012), whereas others were not described before. The correlation of the periods of growth in seismic activity with the decrease of the average depth of earthquakes can be explained by the growth of fluid activity and the tendency of a penetration of low density fluids into the upper horizons of the lithosphere. The unexpectedly strong Tohoku mega earthquake with a rather small rupture area caused an unexpectedly high tsunami wave. From here it seems plausible that M9+ earthquakes with a large tsunami could occur in other subduction zones where such cases were suggested before to be impossible.

Rodkin, M. V.; Tikhonov, I. N.

2014-12-01

321

Mega compartment complex in the Anadarko basin: A completely sealed overpressured phenomenon  

Energy Technology Data Exchange (ETDEWEB)

Integrated pressure, potentiometric, and geologic data demonstrate the existence of a basin-wide, completely sealed overpressured compartment in the Anadarko basin. All reservoirs within this complex exhibit pressure gradients ranging form 0.6 to 0.98 psi/feet, which exceeds the normal gradient of 0.465 psi/feet. These reservoirs have produced large quantities of natural gas, particularly from the Pennsylvanian Red Fork and Morrowan sandstones. This mega compartment complex is enclosed by top, bottom, and lateral seals. The top seal, which is located between 8,500 and 11,000 feet below the surface, is relatively horizontal, dips slightly to the southwest, and appears to cut across stratigraphy. However, the basal seal is stratigraphically controlled and seems to coincide with the Devonian Woodford Shale. The complex is laterally sealed to the south by the Wichita Mountain uplift frontal fault zone and by the convergence of the top and basal seals along the eastern, northern, and western boundaries. Nested within this complex is a myriad of smaller compartments with their own distinct pressure gradients. In addition, local overpressured compartments are present outside the mega compartment complex in normal and near-normal pressured regions. Significant gas fields producing from the Morrow and Red Fork horizons are considered nested compartments within the mega compartment complex. The Southwest Leedey field contains a stratigraphically and/or lithologically sealed Red Fork sandstone compartment. The Upper Morrowan chert conglomerate reservoirs in the Cheyenne field area comprise a compartment with a distinct lateral seal associated with the frontal fault zone of the Wichita Mountain uplift.

Al-Shaieb, Z.; Puckette, J.; Ely, P.; Abdalla, A. (Oklahoma State Univ., Stillwater, OK (United States))

1991-03-01

322

Plasmid content of isolates of Erwinia amylovora from orchards in Washington and Oregon in the USA  

Science.gov (United States)

Nearly all strains of Erwinia amylovora carry plasmid pEA29, which has not been found in other species of bacteria. Additional plasmids have been reported in the pathogen isolates from Western states, such as a plasmid in strain CA11 that carries streptomycin-resistance genes and the plasmid pEU30,...

323

Bacterial plasmids that carry two functional centromere analogs are stable and are partitioned faithfully.  

OpenAIRE

The par genes of unit-copy plasmids P1 and F promote equitable distribution of plasmid copies to daughter cells and can be considered to be functional analogs of eucaryotic centromeres. Composite plasmids were constructed which carry either two functional P1 par regions or one F and one P1 region. Unlike dicentric chromosomes, such plasmids are stably maintained.

Austin, S. J.

1984-01-01

324

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

OpenAIRE

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.

Goering, R. V.; Ruff, E. A.

1983-01-01

325

Role of water-saving devices in reducing urban water consumption in the mega-city of Tehran, case study: a residential complex.  

Science.gov (United States)

Iran is one of 27 countries that are likely to face increasing water shortage crises between now and 2025 unless action is taken to reduce currently high-per-capita urban water consumption. Accordingly, consumption control in the mega-city of Tehran will be an invaluable achievement. A study of Tehran water consumers has determined that household consumers are responsible for 70 percent of the total consumption. Keeping that figure in mind, the authors set out to assess rates of consumption by water fixtures, with an emphasis on household users, and to examine the effects of installing subcounters and reducers. They selected an apartment complex in which it was possible to install water subcounters for each unit. The first step was to evaluate resident attitudes. Block 3, which had 10 units, was selected to cooperate with the project. The second step was to install counters for all 10 units to determine consumption by different fixtures. (The counters were installed in kitchens, in bathrooms, on toilets, on washing machines, and on flash tanks). In the next step, data entry forms for fixture consumption were completed for a period of 10 days. Then single-handle faucets and reducers were installed, and the outcomes were logged for a period of 10 days. Counter readings were performed by the volunteer residents or by educated personnel every 24 hours, and the total volume of inside consumption was compared with the consumption registered by a base counter placed outside each unit. In the course of the project, the consumption per capita was calculated every 24 hours to yield a real and unbiased model that is applicable to city of Tehran. The results showed a total reduction in water consumption of about 20 percent. Thus, with suitable planning and application of cultural and technical methods, it is possible to optimize consumption in Tehran in the near future. PMID:18468223

Bidhendi, Gholamreza Nabi; Nasrabadi, Touraj; Vaghefi, Hamid Reza Sharif; Hoveidi, Hassan; Jafari, Hamid Reza

2008-04-01

326

Festifavelisation: mega-events, slums and strategic city-staging – the example of Rio de Janeiro  

Directory of Open Access Journals (Sweden)

Full Text Available Mega-events are increasingly often taking place in countries of the Global South. In the socio-spatially deeply fragmented host cities these spectacles encompass extremely transformative urban processes. This paper will consider the festivalisation of Rio de Janeiro in the preparatory phase of the 2014 FIFA World Cup and the 2016 Summer Olympics. It focuses on the urban policy in relation to how Rio deals with its favelas. The aim of the article is to critically assess current measures of ‘invisibilisation’, ‘pacification’, ‘beautification’ and ‘touristic staging’ of favelas against the backdrop of the upcoming events.

Steinbrink, Malte

2013-11-01

327

Endoprosthetic reconstruction using total femoral custom mega prosthesis in malignant bone tumours  

OpenAIRE

We analysed 17 patients with primary malignant bone tumour of the femur who underwent limb salvage surgery with the total femoral custom mega prosthesis during the period 1994–2008. The patients were in the age group of 12–73 years, with a mean age of 30.94 years. There were 14 males. The most common diagnosis was osteosarcoma. The average follow-up period was 54.05 months with the longest being 168 months. The average Musculoskeletal Tumour Society (MSTS) functional score was 66.6%. ...

Natarajan, Mayil Vahanan; Balasubramanian, Navin; Jayasankar, Viswanath; Sameer, Mohammad

2009-01-01

328

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

Science.gov (United States)

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

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

329

Development of a hardened imaging system for the Laser MegaJoule  

International Nuclear Information System (INIS)

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)

330

Sinapinic acid clusters distribution from monomer to mega Dalton's region in MALDI process  

Science.gov (United States)

In this work, we report the first complete sinapinic acid clusters distribution from monomer to mega Dalton's region by matrix-assisted laser desorption/ionization (MALDI). A decrease of eight orders in intensity was observed from monomer ion to 10 000-mer ion. The results fit to the model of laser ablation induced desorption process with bimodal power-law dependence. In addition, the detailed measurements on the populations of different sizes of clusters can provide some insight of different models of the mechanism for MALDI.

Lai, Szu-Hsueh; Chang, Kuang-Hua; Lin, Jung-Lee; Wu, Chia-Lin; Chen, Chung-Hsuan

2013-03-01

331

Development of a hardened imaging system for the Laser MegaJoule  

Directory of Open Access Journals (Sweden)

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.

Rousseau A.

2013-11-01

332

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

International Nuclear Information System (INIS)

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

333

Properties of GPS noise at Japan islands before and after Tohoku mega-earthquake  

OpenAIRE

The field of 3-components GPS signals is analyzed for the network of 1203 stations at the Japanese islands from January 30 up to March 26, 2011. This time interval includes just over 40 days of observation before the Tohoku mega-earthquake on March 11, 2011 (M?=?9.0) and nearly 16 days of observation following this event. The signals from each station are three-component time series with time step 30 minutes. We study the statistical properties of the random fluctuations of GPS signals...

Lyubushin, Alexey; Yakovlev, Pavel

2014-01-01

334

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

International Nuclear Information System (INIS)

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)

335

Macroscopic transport of mega-ampere electron currents in aligned carbon-nanotube arrays.  

Science.gov (United States)

We demonstrate that aligned carbon-nanotube arrays are efficient transporters of laser-generated mega-ampere electron currents over distances as large as a millimeter. A direct polarimetric measurement of the temporal and the spatial evolution of the megagauss magnetic fields (as high as 120 MG) at the target rear at an intensity of (10(18)-10(19))??W/cm2 was corroborated by the rear-side hot electron spectra. Simulations show that such high magnetic flux densities can only be generated by a very well collimated fast electron bunch. PMID:23003966

Chatterjee, Gourab; Singh, Prashant Kumar; Ahmed, Saima; Robinson, A P L; Lad, Amit D; Mondal, Sudipta; Narayanan, V; Srivastava, Iti; Koratkar, Nikhil; Pasley, John; Sood, A K; Kumar, G Ravindra

2012-06-01

336

Tunable Mega-Ampere Electron Current Propagation in Solids by Dynamic Control of Lattice Melt  

Science.gov (United States)

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.

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.

2014-10-01

337

[A plasmid vector with temperature-controlled gene expression].  

Science.gov (United States)

A 169 b.p. fragment including the bla gene promoter p3 has been removed from pBR327 plasmid, and the deleted plasmid used for cloning the TaqI/BglII-fragment of the lambda c1857ind- DNA containing promoter pR and gene cI to obtain plasmid pCE119. Cells containing pCE119 produced a high level of beta-lactamase at 42 degrees C, the yield at 42 degrees C being 100 times higher than at 32 degrees C. For cloning and functional assays a pCEZ12 plasmid was constructed, in which promoter pR and repressor cI of lambda phage control the expression of the semi-synthetic beta-galactosidase gene. Yield of beta-galactosidase produced by pCEZ12 at 42 degrees C was ca. 300 times higher than at 32 degrees C. PMID:2988570

Kravchenko, V V; Iamshchikov, V F; Pletnev, A G

1985-04-01

338

Construction of three new Gateway® expression plasmids for Trypanosoma cruzi.  

Science.gov (United States)

We present here three expression plasmids for Trypanosoma cruzi adapted to the Gateway® recombination cloning system. Two of these plasmids were designed to express trypanosomal proteins fused to a double tag for tandem affinity purification (TAPtag). The TAPtag and Gateway® cassette were introduced into an episomal (pTEX) and an integrative (pTREX) plasmid. Both plasmids were assayed by introducing green fluorescent protein (GFP) by recombination and the integrity of the double-tagged protein was determined by western blotting and immunofluorescence microscopy. The third Gateway adapted vector assayed was the inducible pTcINDEX. When tested with GFP, pTcINDEX-GW showed a good response to tetracycline, being less leaky than its precursor (pTcINDEX). PMID:25424446

Alonso, Victoria L; Ritagliati, Carla; Cribb, Pamela; Serra, Esteban C

2014-12-01

339

The centromere-specific histone variant Cse4p (CENP-A) is essential for functional chromatin architecture at the yeast 2-?m circle partitioning locus and promotes equal plasmid segregation  

OpenAIRE

The centromere protein A homologue Cse4p is required for kinetochore assembly and faithful chromosome segregation in Saccharomyces cerevisiae. It has been regarded as the exquisite hallmark of centromeric chromatin. We demonstrate that Cse4 resides at the partitioning locus STB of the 2-?m plasmid. Cse4p-STB association is absolutely dependent on the plasmid partitioning proteins Rep1p and Rep2p and the integrity of the mitotic spindle. The kinetochore mutation ndc10-1 excludes Cse4p from ce...

Hajra, Sujata; Ghosh, Santanu Kumar; Jayaram, Makkuni

2006-01-01

340

Overwork Among Residents in India: A Medical Resident's Perspective  

OpenAIRE

This paper argues that medical residents who do most of the hard work in big hospitals and medical colleges are overworked. A hierarchical organizational structure, staffing patterns, and fear of failure in examinations leads to overwork among residents going unreported. This can lead to poor academic performance and research work. Gaps in communication have serious implications on patient health. Undesirable practices like LAMA (leave against medical advice) also result from overwork. Issues...

Azhar, Gulrez S.; Azhar, Abdullah Z.; Azhar, Ahmad S.

2012-01-01

341

The Chief Resident Role in Emergency Medicine Residency Programs  

OpenAIRE

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, ...

Hafner, John W. Jr; Gardner, Joanna C. Md; Boston, William S.; Aldag, Jean C.

2010-01-01

342

Evaluation of transportan 10 in PEI mediated plasmid delivery assay.  

OpenAIRE

Cell-penetrating peptides (CPPs) are novel high-capacity delivery vectors for different bioactive cargoes. We have evaluated the CPP transportan 10 (TP10) as a delivery vector in different in vitro plasmid delivery assays. Tested methods include: TP10 crosslinked to a plasmid via a peptide nucleic acid (PNA) oligomer, TP10 conjugation with polyethyleneimine (PEI), and addition of unconjugated TP10 to standard PEI transfection assay. We found that without additional DNA condensing agents, TP10...

Kilk, K.; El-andaloussi, S.; Ja?rver, P.; Meikas, A.; Valkna, A.; Bartfai, T.; Kogerman, P; Metsis, M.; Langel, U.

2005-01-01

343

Stress responses and replication of plasmids in bacterial cells  

OpenAIRE

Abstract Plasmids, DNA (or rarely RNA) molecules which replicate in cells autonomously (independently of chromosomes) as non-essential genetic elements, play important roles for microbes grown under specific environmental conditions as well as in scientific laboratories and in biotechnology. For example, bacterial plasmids are excellent models in studies on regulation of DNA replication, and their derivatives are the most commonly used vectors in genetic engineering. Detailed mechanisms of re...

Wegrzyn Alicja; Wegrzyn Grzegorz

2002-01-01

344

Antimicrobial resistance and the ecology of Escherichia coli plasmids.  

OpenAIRE

Four hundred and seven clinical isolates of Escherichia coli were examined for the presence of plasmids. These isolates comprised 189 which were collected irrespective of antimicrobial resistance (VP) and 218 which were collected on the basis of high-level trimethoprim resistance (TPR). The VP isolates were divided into drug sensitive (VPS) and drug-resistant (VPR) subpopulations. Plasmids were detected in 88% of VP isolates (81% of VPS and 94% of VPR) and 98% of TPR isolates. The distributio...

Platt, D. J.; Sommerville, J. S.; Kraft, C. A.; Timbury, M. C.

1984-01-01

345

Conjugative R plasmids in group C and G streptococci.  

OpenAIRE

Two streptococcal isolates of groups C and G harbored conjugative R plasmids with molecular weights of 17 X 10(6) (pIP646) and 20 X 10(6) (pIP920). These plasmids carried genetic markers for resistance to macrolides and related drugs, as well as to chloramphenicol (pIP920), and have very similar HindIII restriction enzyme patterns.

Bougueleret, L.; Bieth, G.; Horodniceanu, T.

1981-01-01

346

Distribution of heterogeneous and homologous plasmids in Bacillus spp.  

OpenAIRE

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5...

Yoshimura, K.; Yamamoto, O.; Seki, T.; Oshima, Y.

1983-01-01

347

Plasmid Incidence in Bacteria from Deep Subsurface Sediments  

OpenAIRE

Bacteria were isolated from deep terrestrial subsurface sediments underlying the coastal plain of South Carolina. A total of 163 isolates from deep sediments, surface soil, and return drill muds were examined for plasmid DNA content and resistance to the antibiotics penicillin, ampicillin, carbenicillin, streptomycin, kanamycin, and tetracycline. MICs of Cu2+, Cr3+, and Hg2+ for each isolate were also determined. The overall frequency of plasmid occurrence in the subsurface bacteria was 33%. ...

Fredrickson, J. K.; Hicks, R. J.; Li, S. W.; Brockman, F. J.

1988-01-01

348

Plasmid-only rescue of influenza A virus vaccine candidates.  

OpenAIRE

The potential threat of another influenza virus pandemic stimulates discussion on how to prepare for such an event. The most reasonable prophylactic approach appears to be the use of effective vaccines. Since influenza and other negative-stranded RNA viruses are amenable to genetic manipulation using transfection by plasmids, it is possible to outline new reverse genetics-based approaches for vaccination against influenza viruses. We suggest three approaches. First, we use a plasmid-only resc...

Schickli, J. H.; Flandorfer, A.; Nakaya, T.; Martinez-sobrido, L.; Garci?a-sastre, A.; Palese, P.

2001-01-01

349

Genetic transformation of Rhizobium leguminosarum by plasmid DNA.  

OpenAIRE

We demonstrated the genetic transformation of Rhizobium leguminosarum by R68.45 plasmid DNA by freezing and thawing cell suspensions in the presence of R68.45 plasmid DNA and 20 mM MgCl2. Clones resistant to kanamycin and tetracycline were recovered at a frequency of 10(-8) per recipient cell. No colonies that were doubly drug resistant were recovered in parallel control experiments.

Bullerjahn, G. S.; Benzinger, R. H.

1982-01-01

350

A Biobrick Library for Cloning Custom Eukaryotic Plasmids  

OpenAIRE

Researchers often require customised variations of plasmids that are not commercially available. Here we demonstrate the applicability and versatility of standard synthetic biological parts (biobricks) to build custom plasmids. For this purpose we have built a collection of 52 parts that include multiple cloning sites (MCS) and common protein tags, protein reporters and selection markers, amongst others. Importantly, most of the parts are designed in a format to allow fusions that maintain th...

Constante, Marco; Gru?nberg, Raik; Isalan, Mark

2011-01-01

351

Characterization of chimeric plasmid cloning vehicles in Bacillus subtilis.  

OpenAIRE

Restriction endonuclease cleavage maps of seven chimeric plasmids that may be used for molecular cloning in Bacillus subtilis are presented. These plasmids all carry multiple antibiotic resistance markers and were constructed by in vitro molecular cloning techniques. Several of the antibiotic resistance markers were shown to undergo insertional inactivation at specific restriction endonuclease sites. Kanamycin inactivation occurred at the BglII site of pUB110 derivatives, erythromycin inactiv...

Gryczan, T.; Shivakumar, A. G.; Dubnau, D.

1980-01-01

352

Nitrogen fixation (nif) genes and large plasmids of Rhizobium japonicum.  

OpenAIRE

The location of structural nitrogen-fixation genes was determined for the slow- and fast-growing types of Rhizobium japonicum. Slow-growing R. japonicum strains do not harbor structural nif genes, homologous to nifD and nifH, on large plasmids (100 to 200 megadaltons). In contrast, all fast-growing R. japonicum strains, except PRC194, contain structural nif genes on large plasmids.

Masterson, R. V.; Russell, P. R.; Atherly, A. G.

1982-01-01

353

Isolation and properties of plasmids from Deinococcus radiodurans Sark  

International Nuclear Information System (INIS)

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)

354

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

Directory of Open Access Journals (Sweden)

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.

Sergey Karpov

2013-01-01

355

The characteristics of micrococcus (deinococcus) radiodurans sark plasmids  

International Nuclear Information System (INIS)

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

356

Plasmid vector with temperature-controlled gene expression  

International Nuclear Information System (INIS)

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 ? 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 ?-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 ?-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

357

The Addgene repository: an international nonprofit plasmid and data resource.  

Science.gov (United States)

The Addgene Repository (http://www.addgene.org) was founded to accelerate research and discovery by improving access to useful, high-quality research materials and information. The repository archives plasmids generated by scientists, conducts quality control, annotates the associated data and makes the plasmids and their data available to the scientific community. Plasmid associated data undergoes ongoing curation by members of the scientific community and by Addgene scientists. The growing database contains information on >31,000 unique plasmids spanning most experimental biological systems and organisms. The library includes a large number of plasmid tools for use in a wide variety of research areas, such as empty backbones, lentiviral resources, fluorescent protein vectors and genome engineering tools. The Addgene Repository database is always evolving with new plasmid deposits so it contains currently pertinent resources while ensuring the information on earlier deposits is still available. Custom search and browse features are available to access information on the diverse collection. Extensive educational materials and information are provided by the database curators to support the scientists that are accessing the repository's materials and data. PMID:25392412

Kamens, Joanne

2015-01-01

358

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

OpenAIRE

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 ...

Williams, Julia J.; Hergenrother, Paul J.

2008-01-01

359

Frequency and Characteristics of Plasmids in Bacteria Isolated from Deep-Sea Amphipods  

OpenAIRE

Bacterial strains isolated from deep-sea amphipods were identified, classified, and screened for plasmid content. Plasmids were common, with 11 of 16 isolates carrying one or more plasmids; these ranged in size from 2.9 to 63 megadaltons. Several of the strains demonstrated distinctly different phenotypic traits yet contained plasmids of the same molecular weight. Results of agarose gel electrophoresis, DNA hybridization, and restriction analysis indicate that the plasmids detected in these d...

Wortman, Alan T.; Colwell, Rita R.

1988-01-01

360

Comparison of DNA sequences required for the function of citrate utilization among different citrate utilization plasmids.  

OpenAIRE

The relatedness of DNA sequences encoding citrate utilization was examined by hybridization with a cloned DNA fragment from a citrate utilization (Cit) plasmid, pOH30221, and DNA of other Cit plasmids. This revealed that there are at least two groups of Cit plasmids: the Inc W Cit plasmids, which show homology with the probe, and the Inc H1 plasmids, which do not.

Shinagawa, M.; Makino, S.; Hirato, T.; Ishiguro, N.; Sato, G.

1982-01-01

361

The distribution of plasmids among a representative collection of Scottish strains of Salmonellae.  

OpenAIRE

The distribution of plasmids was studied in a representative collection of salmonella strains which comprised 98 Salmonella typhimurium and 96 other serotypes. Plasmids were detected in 72% of strains (mean 1.3 plasmids/strain) and individual strains harboured between 0 and 7 plasmids. They were more common among S. typhimurium than other serotypes (incidence 92 and 53%; mean 1.9 and 0.8 plasmids/strain respectively). Although a higher proportion of S. typhimurium (33%) were antibiotic-resist...

Platt, D. J.; Brown, D. J.; Munro, D. S.

1986-01-01

362

Naturally occurring plasmids exhibiting incompatibility with members of incompatibility groups I and P.  

OpenAIRE

From a group of naturally occurring antibiotic resistance plasmids, a number of plasmids were identified which were incompatible with members of incompatibility group P and also incompatibility group I alpha or I gamma. These plasmids also exhibited strong entry exclusion with members of group P only and showed a host range which resembled that of plasmids of group I rather than those of group P. Segregants of a number of these plasmids appeared to have lost some of the incompatability and/or...

Grant, A. J.; Bird, P. I.; Pittard, J.

1980-01-01

363

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

OpenAIRE

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...

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

1983-01-01

364

DNASU plasmid and PSI:Biology-Materials repositories: resources to accelerate biological research  

OpenAIRE

The mission of the DNASU Plasmid Repository is to accelerate research by providing high-quality, annotated plasmid samples and online plasmid resources to the research community through the curated DNASU database, website and repository (http://dnasu.asu.edu or http://dnasu.org). The collection includes plasmids from grant-funded, high-throughput cloning projects performed in our laboratory, plasmids from external researchers, and large collections from consortia such as the ORFeome Collabora...

Seiler, Catherine Y.; Park, Jin G.; Sharma, Amit; Hunter, Preston; Surapaneni, Padmini; Sedillo, Casey; Field, James; Algar, Rhys; Price, Andrea; Steel, Jason; Throop, Andrea; Fiacco, Michael; Labaer, Joshua

2013-01-01

365

Novel Plasmid Transformation Method Mediated by Chrysotile, Sliding Friction, and Elastic Body Exposure  

OpenAIRE

Escherichia coli as a plasmid recipient cell was dispersed in a chrysotile colloidal solution, containing chrysotile adsorbed to plasmid DNA (chrysotile-plasmid cell mixture). Following this, the chrysotile-plasmid cell mixture was dropped onto the surface of an elastic body, such as agarose, and treated physically by sliding a polystyrene streak bar over the elastic body to create friction. Plasmid DNA was easily incorporated into E. coli, and antibiotic resistance was conferred by transform...

Naoto Yoshida; Toshiaki Nakajima-Kambe; Kaori Matsuki; Toshiya Shigeno

2007-01-01

366

24 CFR 206.39 - Principal residence.  

Science.gov (United States)

...2010-04-01 2010-04-01 false Principal residence. 206.39 Section 206.39 Housing...Eligible Mortgagors § 206.39 Principal residence. The property must be the principal residence of each mortgagor at closing. For...

2010-04-01

367

Electron microscope study of a plasmid chimera containing the replication region of the Escherichia coli F plasmid.  

Science.gov (United States)

pML31, a plasmid chimera constructed to contain the replication genes of an Flac plasmid, has been studied by electron microscope methods. Heteroduplex analysis shows that the only F sequence present in pML31 is that with corrdinates 40.3-49.3F. This region has previously been identified as essential for plasmid maintenance. The sequence of pML31, which was derived originally from R6-5, carries the km gene(s) and an inverted duplication of a 1.0-kilobase sequence. On the basis of length measurements, the repeated sequence is different from IS1, IS2, IS3, and an inverted repeat associated with the km gene(s) of plasmid JR67. Images PMID:783125

Guyer, M S; Figurski, D; Davidson, N

1976-01-01

368

IncP-1? plasmids of Comamonas sp. and Delftia sp. strains isolated from a wastewater treatment plant mediate resistance to and decolorization of the triphenylmethane dye crystal violet.  

Science.gov (United States)

The application of toxic triphenylmethane dyes such as crystal violet (CV) in various industrial processes leads to large amounts of dye-contaminated sludges that need to be detoxified. Specific bacteria residing in wastewater treatment plants (WWTPs) are able to degrade triphenylmethane dyes. The objective of this work was to gain insights into the genetic background of bacterial strains capable of CV degradation. Three bacterial strains isolated from a municipal WWTP harboured IncP-1? plasmids mediating resistance to and decolorization of CV. These isolates were assigned to the genera Comamonas and Delftia. The CV-resistance plasmid pKV29 from Delftia sp. KV29 was completely sequenced. In addition, nucleotide sequences of the accessory regions involved in conferring CV resistance were determined for plasmids pKV11 and pKV36 from the other two isolates. Plasmid pKV29 contains typical IncP-1? backbone modules that are highly similar to those of previously sequenced IncP-1? plasmids that confer antibiotic resistance, degradative capabilities or mercury resistance. The accessory regions located between the conjugative transfer (tra) and mating pair formation modules (trb) of all three plasmids analysed share common modules and include a triphenylmethane reductase gene, tmr, that is responsible for decolorization of CV. Moreover, these accessory regions encode other enzymes that are dispensable for CV degradation and hence are involved in so-far-unknown metabolic pathways. Analysis of plasmid-mediated degradation of CV in Escherichia coli by ultra-high-performance liquid chromatography-electrospray ionization-quadrupole-time-of-flight MS revealed that leuco crystal violet was the first degradation product. Michler's ketone and 4-dimethylaminobenzaldehyde appeared as secondary degradation metabolites. Enzymes encoded in the E. coli chromosome seem to be responsible for cleavage of leuco crystal violet. Plasmid-mediated degradation of triphenylmethane dyes such as CV is an option for the biotechnological treatment of sludges contaminated with these dyes. PMID:22653947

Stolze, Yvonne; Eikmeyer, Felix; Wibberg, Daniel; Brandis, Gerrit; Karsten, Christina; Krahn, Irene; Schneiker-Bekel, Susanne; Viehöver, Prisca; Barsch, Aiko; Keck, Matthias; Top, Eva M; Niehaus, Karsten; Schlüter, Andreas

2012-08-01

369

Exogenous Isolation of Antibiotic Resistance Plasmids from Piggery Manure Slurries Reveals a High Prevalence and Diversity of IncQ-Like Plasmids  

OpenAIRE

Antibiotic resistance plasmids were exogenously isolated in biparental matings with piggery manure bacteria as plasmid donors in Escherichia coli CV601 and Pseudomonas putida UWC1 recipients. Surprisingly, IncQ-like plasmids were detected by dot blot hybridization with an IncQ oriV probe in several P. putida UWC1 transconjugants. The capture of IncQ-like plasmids in biparental matings indicates not only their high prevalence in manure slurries but also the presence of efficiently mobilizing p...

Smalla, Kornelia; Heuer, Holger; Go?tz, Antje; Niemeyer, Dagmar; Kro?gerrecklenfort, Ellen; Tietze, Erhard

2001-01-01

370

Expansion of the IncX plasmid family for improved identification and typing of novel plasmids in drug-resistant Enterobacteriaceae  

DEFF Research Database (Denmark)

IncX plasmids are narrow host range plasmids of Enterobactericeae that have been isolated for over 50years. They are known to encode type IV fimbriae enabling their own conjugative transfer, and to provide accessory functions to their host bacteria such as resistance towards antimicrobial agents and biofilm formation. Previous plasmid-based replicon typing procedures have indicated that the prevalence of IncX plasmids is low among members of the Enterobacteriaceae. However, examination of a number of IncX-like plasmid sequences and their occurrence in various organisms suggests that IncX plasmid diversity and prevalence is underappreciated. To address these possible shortcomings, we generated additional plasmid sequences of IncX plasmids of interest and compared them to the genomes of all sequenced IncX-like plasmids. These comparisons revealed that IncX plasmids possess a highly syntenic plasmid backbone, but that they are quite divergent with respect to nucleotide and amino acid similarity. Based on phylogenetic comparisons of the sequenced IncX plasmids, the IncX plasmid group has been expanded to include at least four subtypes, IncX1-IncX4. A revised IncX plasmid replicon typing procedure, based upon these sequences and subtypes, was then developed. Use of this revised typing procedure revealed that IncX plasmid occurrence among bacterial populations is much more common than had previously been acknowledged. Thus, this revised procedure can be used to better discern the occurrence of IncX type plasmids among enterobacterial populations.

Johnson, Timothy J.; Bielak, Eliza Maria

2012-01-01

371

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

International Nuclear Information System (INIS)

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 BEPC?, 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)

372

Mega-Lake in the Kalahari: A Late Pleistocene record of the Palaeolake Makgadikgadi system  

Science.gov (United States)

A distinct series of beach ridges marking the former shorelines of large inter-connected lacustrine basins in the Kalahari can be clearly identified from Landsat imagery and Shuttle Radar Topography Mission (SRTM) data. These basins, which form the terminal sump of the Okavango system in northern Botswana, are now almost completely dry. During the Quaternary they were intermittently occupied by large stable lake bodies and are thought to have periodically filled to a point of coalescence inundating an area that, at its largest extent, encompassed 66,000 km 2. Poor chronological control has previously limited the utility of this important palaeo-archive. As part of a region-wide lake palaeo-shoreline research programme, a systematic optically stimulated luminescence (OSL) dating programme has utilised a lightweight hydraulic auger to take samples at depth from relict shoreline features. Twenty drill-sites have generated 140 samples for dating, establishing a firm chronology for multiple lake full phases in all three component basins (Ngami, Mababe and Makgadikgadi) of this mega-lake. This paper presents the final set of ages in the programme, derived from four cores from the western and north-eastern shorelines of Makgadikgadi, and uses these ages to establish a chronology of mega-lake high-stands during the last ˜300 ka providing a rare directly dated, long terrestrial record of positive hydrological excursions within the southern hemisphere.

Burrough, Sallie L.; Thomas, David S. G.; Bailey, Richard M.

2009-07-01

373

MISR Aerosol Air Mass Type Mapping over Mega-City Environments: Validation and Applications  

Science.gov (United States)

Most aerosol air-quality monitoring in mega-city environments is done from scattered ground stations having detailed chemical and optical sampling capabilities. The Multi-angle Imaging SpectroRadiometer (MISR) can retrieve total-column Aerosol Optical Depth (AOD), along with some information about particle microphysical properties. Although the particle property information from MISR is much less detailed than that obtained from the ground sampling stations, the coverage is extensive, making it possible to put individual surface observations into the context of regional aerosol air mass types. This study presents an analysis of MISR aerosol observations made coincident with aircraft and ground-based instruments during the INTEX-B and DISCOVER-AQ field campaigns. These detailed comparisons of satellite aerosol property retrievals against dedicated field measurements provide the opportunity to validate the retrievals quantitatively at a regional level, to help improve aerosol representation in retrieval algorithms, and to demonstrate the relationships among suborbital measurements through MISR-derived regional aerosol air mass types maps. Validation of MISR retrieved AOD and aerosol properties over the INTEX-B and DISCOVER-AQ study regions will be presented. MISR's ability to distinguish among aerosol air mass types will also be presented, based on high-resolution MISR research retrieval results. The goal of this effort is to use the MISR aerosol property retrievals for mapping both aerosol air mass type and AOD gradients in mega-city environments over the decade-plus that MISR has made global observations.

Patadia, F.; Kahn, R. A.; Limbacher, J.

2012-12-01

374

MISR Aerosol Air Mass Type Mapping over Mega-City: Validation and Applications  

Science.gov (United States)

Most aerosol air-quality monitoring in mega-city environments is done from scattered ground stations having detailed chemical and optical sampling capabilities. Satellite instruments such as the Multi-angle Imaging SpectroRadiometer (MISR) can retrieve total-column Aerosol Optical Depth (AOD), along with some information about particle microphysical properties. Although the particle property information from MISR is much less detailed than that obtained from the ground sampling stations, the coverage is extensive, making it possible to put individual surface observations into the context of regional aerosol air mass types. This study presents an analysis of MISR aerosol observations made coincident with aircraft and ground-based instruments during the INTEX-B field campaign. These detailed comparisons of satellite aerosol property retrievals against dedicated field measurements provide the opportunity to validate the retrievals quantitatively at a regional level, and help to improve aerosol representation in retrieval algorithms. Validation of MISR retrieved AOD and other aerosol properties over the INTEX-B study region in and around Mexico City will be presented. MISR's ability to distinguish among aerosol air mass types will be discussed based on high resolution MISR research retrievals. The goal of this effort is to use the MISR aerosol property retrievals for mapping both aerosol air mass type and AOD gradients in mega-city environments over the decade-plus that MISR has made global observations.

Patadia, F.; Kahn, R. A.

2011-12-01

375

Photon detector for MEGA. Final report, July 16, 1992--May 31, 1993  

International Nuclear Information System (INIS)

During the past year, we have continued our work on the photon detector for the MEGA experiment at Los Alamos. The MEGA photon detector is designed to observe the 52.83 MeV photon produced in a ? ? e? decay with an energy resolution of 1.25 MeV, a position resolution of 2 x 5 mm2, a directional resolution of 10 degree, a time resolution of 500 ps, and an efficiency of about 5.4%. (All quoted resolutions are FWHM.) It consists of three independent concentric cylindrical pair spectrometers mounted within a 1.5 T magnetic field produced by a superconducting solenoid magnet. Each pair spectrometer includes two thin (0.045 radiation lengths each) Pb foils to convert photons into e+e- pairs. The two smaller pair spectrometers have three drift chamber layers to track the e+e- pairs and thereby determine both their locations and their vector momenta. The third pair spectrometer has four layers of drift chamber, together with a larger turning region, to provide better tracking information for high energy photons such as those from the ?0 ? 2? decay

376

The IUE Mega Campaign: Wind Variability and Rotation in Early-Type Stars  

Science.gov (United States)

Wind variability in OB stars may be ubiquitous and a connection between projected stellar rotation velocity and wind activity is well established. However, the origin of this connection is unknown. To probe the nature of the rotation connection, several of the attendees at the workshop on Instability and Variability of Hot-Star Winds drafted an IUE observing proposal. The goal of this program was to follow three stars for several rotations to determine whether the rotation connection is correlative or causal. The stars selected for monitoring all have rotation periods less than or equal to 5 days. They were HD 50896 (WN5), HD 64760 (BO.5 Ib), and HD 66811 (zeta Pup; 04 If(n)). During 16 days of nearly continuous observations in 1995 January (dubbed the 'MEGA' campaign), 444 high-dispersion IUE spectra of these stars were obtained. This Letter presents an overview of the results of the MEGA campaign and provides an introduction to the three following Letters, which discuss the results for each star.

Massa, D.; Fullerton, A. W.; Nichols, J. S.; Owocki, S. P.; Prinja, R. K.; St-Louis, N.; Willis, A. J.; Altner, B.; Bolton, C. T.; Cassinelli, J. P.; Cohen, D.; Cooper, R. G.; Feldmeier, A.; Gayley, K. G.; Harries, T.; Heap, S. R.; Henriksen, R. N.; Howarth, I. D.; Hubeny, I.; Kambe, E.

1995-01-01

377

Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results  

CERN Document Server

We present the first results of a wide field survey for cool brown dwarfs with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and to constrain the field-brown dwarf mass function thanks to a larger sample of L and T dwarfs. We identify candidates in CFHT/MegaCam i' and z' images using optimised psf-fitting within Source Extractor, and follow them up with pointed near-infrared imaging on several telescopes. We have so far analysed over 350 square degrees and found 770 brown dwarf candidates brighter than z'{AB}=22.5. We currently have J-band photometry for 220 of these candidates, which confirms 37% as potential L or T dwarfs. Some are among the reddest and farthest brown dwarfs currently known, including an independent identification of the recently published ULAS J003402.77-005206.7 and the discovery of a second brown dwarf later than T8, CFBDS J005910.83-011401.3. Infrared spectra of three T dwarf candidates ...

Delorme, Philippe; Forveille, Thierry; Delfosse, Xavier; Reylé, Céline; Bertin, Emmanuel; Albert, Loic; Artigau, Etienne; Robin, Annie C; Allard, France; Doyon, Rene; Hill, Gary J

2008-01-01

378

A case with mega cisterna magna renal and ear anomalies: is this a new syndrome?  

Science.gov (United States)

Background. Extrarenal pathologies may be associated with renal position and fusion anomalies. According to the literature, our patient is the first horseshoe kidney case that had mega cisterna magna, arachnodactyly, and mild mental retardation. Case Report. A 9-year-old boy admitted because of the myoclonic jerks. He had a dysmorphic face, low-set and cup-shaped ears, arachnodactyly, and mild mental retardation. The patient's laboratory findings were normal except for a mild leucocytosis and hypochromic microcytic anemia. His cerebrospinal fluid was cytologically and biochemically normal. Cranial MRI revealed 1.5?cm diametered mega cisterna magna in the retrocerebellar region. Although there were no significant epileptical discharges in the electroencephalography, there were slow wave discharges arising from the anterior regions of both hemispheres. Because he had stomachache, abdominal ultrasonography was performed, and horseshoe kidney was determined. Abdominal CT did not reveal any abnormalities except the horseshoe kidney. There were not any cardiac pathologies in echocardiography. He had normal 46XY karyotype and there were no repeated chromosomal derangements, but we could not evaluate for molecular and submicroscopic somatic changes. He was treated with valproic acid and myoclonic jerks did not repeat. Conclusion. We suggest that the presence of these novel findings may represent a newly recognized, separate syndrome. PMID:23762068

Konca, Capan; Caliskan, Bahar; Tas, Mehmet Ali

2013-01-01

379

Design and optimization of MeV class Compton scattering MEGa-ray sources  

Science.gov (United States)

The design and optimization of a Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering source are presented. A new precision source with up to 2.5 MeV photon energies, enabled by state of the art laser and x-band linac technologies, is currently being built at LLNL. Various aspects of the theoretical design, including dose and brightness optimization, will be presented. In particular, while it is known that nonlinear effects occur in such light sources when the laser normalized potential is close to unity, we show that these can appear at lower values of the potential. A three dimensional analytical model and numerical benchmarks have been developed to model the source characteristics, including nonlinear spectra. Since MEGa-ray sources are being developed for precision applications such as nuclear resonance fluorescence, assessing spectral broadening mechanisms is essential. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Albert, Felicie; Anderson, S. G.; Betts, S. M.; Cross, R. R.; Ebbers, C. A.; Houck, T. L.; Gibson, D. J.; Marsh, R. A.; Messerly, M.; Shverdin, M. Y.; Wu, S. S.; Hartemann, F. V.; Siders, C. W.; Scarpetti, R. D.; Barty, C. P. J.

2010-11-01

380

Sustainable Science? Reducing the Carbon Impact of Scientific Mega-Meetings  

Directory of Open Access Journals (Sweden)

Full Text Available Scientists across the globe recognize the importance of reducing carbon emissions to combat climate change.  At the same time, we have increased our carbon footprint through air travel to the growing number of scientific society “mega-meetings” that host thousands of attendees.  Although alternative solutions have been proposed to reduce the environmental impact of annual conferences, these have yet to be evaluated against the business-as-usual scenario.  Here, we use 9 years of annual meeting attendance data from the Ecological Society of America and the Association of American Geographers to assess the efficacy of two additional solutions: 1 alternate large national meetings that require significant air travel with smaller regional meetings that do not; and 2 incorporate geography into the meeting location selection process.  The carbon footprint of annual mega-meetings ranged 3-fold, from 1196-4062 metric tons of CO2.  Results indicate that an alternating schedule of national and regional meetings can reduce conference-related CO2 emissions up to 73%, while improved spatial planning may result in further reductions.  We discuss the benefits and tradeoffs of proposals to green scientific meetings, with a view to spark further debate on how to increase the sustainability of scientific conferences.

Alexandra G. Ponette-González

2011-10-01

381

Radiosensitivity of plasmid DNA: role of topology and concentration  

Science.gov (United States)

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 pBS. 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 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. En utilisant la technique de relaxation de plasmide, l'induction de cassures simple brin (SSB) par les radiations ? a été comparée dans deux plasmides de taille différente, pSP189 et pBS. La relation dose-effet est linéaire pour les deux plasmides, mais il se forme trois fois plus de SSB dans pSP189 que dans pBS. Cette disparité semble pouvoir être reliée au degré de compaction différent des plasmides, observé en microscopie électronique. Elle s'expliquerait en terme d'accessibilité aux espèces radicalaires formées lors de la radiolyse de l'eau. Le plasmide pBS, à différentes concentrations, a été ensuite exposé aux radiations ?. Le taux de cassures décroit lorsque la concentration en ADN croit, suggérant une diminution du nombre de radicaux pouvant efficacement réagir avec l'ADN. Cet effet a également été mis en évidence lors d'une irradiation avec des particules de TEL élevé. En conclusion, l'accessibilité de l'ADN est un paramètre- clé dans la formation des dommages, tant in vitro que in vivo.

Giustranti, C.; Pérez, C.; Rousset, S.; Balanzat, E.; Sage, E.

1999-01-01

382

Geologic support for the putative Borealis basin (Mega-Impact) on Mars  

Science.gov (United States)

A series of recent papers (all in Nature v. 453) using Martian gravity and topography [Andrews-Hanna et al., 2008], 3-D hydrodynamic simulations [Marinova et al., 2008], and 2-D hydrocode models [Nimmo et al., 2008] have eloquently reintroduced the single mega-impact hypothesis for the formation of the Martian hemispheric dichotomy boundary. Although geophysical models often return non-unique solutions, the coalition front presented by these three independent methods to test such a hypothesis lends credibility and demands further evaluation. The central tenet of these works is the proposition that an elliptical basin (long axis 10,600km, ellipticity 1.25) centered at 67N, 208E marks the pre-Tharsis crustal thickness transition and thus the real dichotomy boundary. Evaluation of this new boundary with respect to the geologic record offers new avenues, especially since geologic tests of the mega-impact hypothesis have mostly proved inconclusive because of Mars' multi-stage and multi-process geologic history. Within this survey, a slightly larger ellipse with a long axis of 12,500 km, ellipticity of 1.48, and centered at 65.3N, 250E expands the putative Borealis impact basin (which does not necessarily represent the transient or final impact cavity dimensions, but defines a potential 'affected zone') while maintaining agreement with the original observations with respect to gravity and topography. The 'affected zone' can be defined by basement structure that may become susceptible to later deformation, or it may in fact have been the paleo- topographic expression of the basin. By expanding the overall area (nearly twice the area of the original mega-impact basin proposed by Wilhelms and Squyres in 1984) several geologic features become significant in evaluating the mega-impact story. 1) Valles Marineris is concentric to the putative basin interior and parallels the ellipse margin suggesting that it is the structural manifestation of localized crustal relaxation of the Tharsis volcanic pile over pre-existing basement structure related to Borealis basin subsidence. The present day Valles Marineris may actually represent the 'missing portion' of the original crustal dichotomy trace underneath Tharsis. 2) The 'great faults' (Connerney et al., 2005) that offset the magnetic field pattern radiate from near the center of the putative basin, again suggesting basement structural control related to basin formation. 3) The mysterious Medusa Fossae Formation is completely enclosed within the basin margin and the units' southern contacts fall within 5 km of the same elliptical trace that bisects central Valles Marineris. 4) Chaos regions at the eastern end of Valles Marineris are wholly contained within the basin margin and suggest some kind of marginal control on their locations. 5) Valley network (channel) densities sharply increase outside the basin and are truncated by the Borealis ellipse. Integrating these and other geologic observations (still ongoing) with the newly formulated geophysical methods suggests that a single mega-impact is reemerging as a viable and perhaps preferred mechanism for dichotomy formation.

Bleamaster, L. F.

2008-12-01

383

Gas and Dust Phenomena of Mega-earthquakes and the Cause  

Science.gov (United States)

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 dense natural (methane) gas suddenly escaped from deep crust traps along deep fault zones. References Yue, ZQ, 2009. The source of energy power directly causing the May 12 Wenchuan Earthquake: Huge extremely pressurized natural gases trapped in deep Longmen Shan faults. News Journal of China Society of Rock Mechanics and Engineering, 86 (2009 (2)), 45-50. Yue, ZQ, 2010. Features and mechanism of coseismic surface ruptures by Wenchuan Earthquake. in Rock Stress and Earthquake, edited by Furen Xie, Taylor & Francis Group, London, ISBN 978-0-415-60165-8, 761-768. Yue, ZQ, 2013a. Natural gas eruption mechanism for earthquake landslides: illustrated with comparison between Donghekou and Papandayan Rockslide-debris flows. in Earthquake-induced Landslides, K. Ugai et al. (eds.), Springer-Verlage Berlin, Chapter 51: pp. 485-494 Yue ZQ, 2013b. On incorrectness in elastic rebound theory for cause of earthquakes. Paper No. S20-003 of Session S20, Proceedings of the 13th International Conference on Fracture, June 16-21, Beijing. Yue ZQ, 2013c. On nature of earthquakes with cause of compressed methane gas expansion and migration in crustal rocks, in Proceedings of Fifth Biot Conference on Poromechanics in Memory of Karl von Terzaghi (1883-1963), July 10-12, Vienna, edited by C. Hellmich et al, @ASCE, pp. 507-516.

Yue, Z.

2013-12-01

384

POTENTIAL FOR TRANSDUCTION OF PLASMIDS IN A NATURAL FRESHWATER ENVIRONMENT: EFFECT OF PLASMID DONOR CONCENTRATION AND A NATURAL MICROBIAL COMMUNITY ON TRANSDUCTION IN 'PSEUDOMONAS AERUGINOSA'  

Science.gov (United States)

The transduction of Pseudomonas aeruginosa plasmid Rms149 by the generalized transducing phage DS1 was shown to occur during a nine day incubation of environmental test chambers in a freshwater reservoir. Plasmid DNA was transferred from a nonlysogenic plasmid donor to a DS1 lyso...

385

A mutant defective in partitioning of composite plasmid Rms201.  

Science.gov (United States)

Escherichia coli harboring mutant plasmids defective in maintenance stability (from the conjugative plasmid Rms201) showed a wide distribution of ampicillin resistance levels, as well as increased frequency of plasmid loss from the cell. The amounts of covalently closed circular deoxyribonucleic acid of mutant plasmid Rms268 and parental plasmid Rms201 per chromosome were 5.3 and 6.1%, respectively. The beta-lactamase activities of strains W3630(Rms268) and W3630(Rms201) were 0.56 and 0.44 U/mg of protein, respectively. Frequency of plasmid loss from W3630(Rms268) was about 0.8 to 1.2% per cell generation, 100 times more than that of the wild-type strain. Ampicillin resistance levels of the colonies harboring the mutant plasmid showed a wide distribution, from low (100 micrograms/ml) to high (1,600 micrograms/ml). A miniplasmid (pMS268) with a mass of 7 X 10(6) daltons and encoding ampicillin resistance was isolated from Rms268. Frequency of pMS268 loss from W3630(pMS268) was about 0.8 to 1.9% per cell generation. W3630(pMS268) also showed a wide range of distribution in the levels of ampicillin resistance. These results indicated that the copies of Rms268 in E. coli did not segregate evenly between daughter cells at cell division and that the gene involved was located on the miniplasmid. PMID:6267015

Ike, Y; Hashimoto, H; Mitsuhashi, S

1981-08-01

386

Plasmid Profiles of Antibiotic Resistant Salmonella Species Isolated in Muscat, Oman  

Directory of Open Access Journals (Sweden)

Full Text Available Different Salmonella species (159 strains were isolated from human and non-human sources were exposed to eighteen different antibiotics. 48 strains showed resistance to one or more antibiotics. Resistant strains were examined for their R- plasmids contents by glass fines, boiling miniprep and agarose electrophoresis procedures. All but three of the tested strains from chicken contained a plasmid with similar molecular weight (m.w. even though the strains were resistant to different antibiotics. The remaining three strains contained an additional plasmid with a different electrophoretic migration pattern. Many of the plasmids when digested with endonucleases were found to have similar fragments. Out of four plasmids extracted from Salmonella strains isolated from sheep, three contained one type of a plasmid with similar m.w. and fragmentation. Broad diversity was noted in plasmids extracted from Salmonella strains isolated from humans. Endonuclease digestion of plasmids revealed that some plasmids have a common fingerprint pattern.

S. N. Al-Bahry

2000-01-01

387

Plasmids in Vibrio parahemolyticus strains isolated in Japan and Bangladesh with special reference to different distributions.  

Science.gov (United States)

We surveyed plasmids in naturally occurring Vibrio parahemolyticus strains isolated in Japan and Bangladesh. Among the strains isolated in Japan, about half of the strains isolated from stools of patients of domestic diarrhea outbreaks as well as of travelers returning from East Asia were found to have plasmids, but no strains from foods had plasmids. In contrast, among the strains isolated in Bangladesh, none of the four strains isolated from patients had plasmids, but two out of eight strains isolated from water had plasmids, suggesting that plasmids are common in strains from the water in Bangladesh. All plasmids so far reported in V. parahemolyticus were detected in strains isolated from stools of patients. Incidences of plasmids in this organism were not so high in either area. In Japan, all plasmids were detected in strains from human intestines at 37 C, but in Bangladesh, where the temperature is around 30-40 C, the plasmids were detected in strains from the natural environment. These results suggested the possibility that these plasmids can come from different bacteria under rather high temperatures and that incidences of plasmids are influenced by the incidences of plasmids in bacteria present in the vicinity of V. parahemolyticus strains. None of these plasmids were found to have any relation to the biological characters tested. PMID:6676628

Arai, T; Ando, T; Kusakabe, A; Ullah, M A

1983-01-01

388

Characterization of blaCMY-2 Plasmids in Salmonella and Escherichia coli Isolates from Food Animals in Canada  

OpenAIRE

One hundred thirty-four blaCMY-2 plasmids from Salmonella and Escherichia coli strains from animals and food in Canada were characterized. Five plasmid groups were identified based on replicon type and restriction profiles. Three groups contained E. coli plasmids only. IncA/C plasmids included most multiresistant plasmids and all those of bovine origin.

Martin, Laura C; Weir, Emily K.; Poppe, Cornelis; Reid-smith, Richard J.; Boerlin, Patrick

2012-01-01

389

Replication of an origin-containing derivative of plasmid RK2 dependent on a plasmid function provided in trans  

Science.gov (United States)

pRK212.2, a derivative of the broad host range plasmid RK2, contains two EcoRI cleavage fragments, A and B, neither of which can replicate by itself in Escherichia coli. Fragment A (41.7 kilobases), but not fragment B (14.4 kilobases), can be cloned by insertion into the unrelated plasmids mini-F and ColE1. Fragment B contains the origin of replication and the ampicillin-resistance determinant of RK2. Transformation of E. coli cells containing the mini-F-fragment A hybrid plasmid with fragment B DNA results in the recircularization and replication of fragment B as a nonmobilizable plasmid (pRK2067) with the copy number and incompatibility properties of RK2. Fragment B cannot be cloned in the absence of fragment A because the latter fragment suppresses a function, specified by fragment B, that results in loss of host cell viability. A small segment (2.4 kilobases) of fragment B that contains the RK2 origin of replication but no longer affects host cell growth in the absence of fragment A had been cloned previously by insertion into a ColE1 plasmid. This hybrid plasmid, designated pRK256, will replicate in E. coli polA mutants only when a fragment A-bearing helper plasmid is present. These results demonstrate that the potentially lethal function specified by fragment B of RK2 is not necessary for replication and that at least one trans-acting function is directly involved in RK2 replication. Images PMID:377280

Figurski, David H.; Helinski, Donald R.

1979-01-01

390

Involvement of Tn4430 in transfer of Bacillus anthracis plasmids mediated by Bacillus thuringiensis plasmid pXO12.  

Science.gov (United States)

The self-transmissible plasmid pXO12 (112.5 kilobases [kb]), originally isolated from strain 4042A of Bacillus thuringiensis subsp. thuringiensis, codes for production of the insecticidal crystal protein (Cry+). The mechanism of pXO12-mediated plasmid transfer was investigated by monitoring the cotransfer of the tetracycline resistance plasmid pBC16 (4.2 kb) and the Bacillus anthracis toxin and capsule plasmids, pXO1 (168 kb) and pXO2 (85.6 kb), respectively. In matings of B. anthracis donors with B. anthracis and Bacillus cereus recipients, the number of Tcr transcipients ranged from 4.8 x 10(4) to 3.9 x 10(6)/ml (frequencies ranged from 1.6 x 10(-4) to 7.1 x 10(-2), and 0.3 to 0.4% of them simultaneously inherited pXO1 or pXO2. Physical analysis of the transferred plasmids suggested that pBC16 was transferred by the process of donation and that the large B. anthracis plasmids were transferred by the process of conduction. The transfer of pXO1 and pXO2 involved the transposition of Tn4430 from pXO12 onto these plasmids. DNA-DNA hybridization experiments demonstrated that Tn4430 was located on a 16.0-kb AvaI fragment of pXO12. Examination of Tra- and Cry- derivatives of pXO12 showed that this fragment also harbored information involved in crystal formation and was adjacent to a restriction fragment containing DNA sequences carrying information required for conjugal transfer. PMID:2536653

Green, B D; Battisti, L; Thorne, C B

1989-01-01

391

Bacterial plasmid transfer under space flight conditions: The Mobilisatsia experience  

Science.gov (United States)

Background Microorganisms are subject to a genetic evolution which may lead to the capacity to colonize new environments and to cause infections Central players in this evolutionary process are mobile genetic elements phages plasmids and transposons The latter help to mobilize and reorganize genes be it within a given genome intragenomic mobility or between bacterial cells intercellular mobility Confined environment and space flight related factors such as microgravity and cosmic radiation may influence the frequency with which mobile genetic elements are exchanged between microorganisms Aim Within the frame of the Mobilisatsia experiment a triparental microbial plasmid transfer was promoted aboard the International Space Station ISS The efficiency of the plasmid exchange process was compared with a synchronously performed ground control experiment An experiment was carried out with well-characterized Gram-negative test strains and one experiment was done with Gram-positive test strains Results The experiment took place during the Soyouz Mission 8 to the ISS from April 19th until April 30th 2004 Liquid cultures of the bacterial strains Cupriavidus metallidurans AE815 final recipient Escherichia coli CM1962 carrying a mobilisable vector with a nickel-resistance marker and E coli CM140 carrying the Broad Host Range plasmid RP4 for the Gram-negative experiment and Bacillus thuringiensis Bti AND931 carrying the conjugative plasmid pXO16 Bti 4Q7 with mobilisable vector pC194 carrying a resistance to chloramphenicol and Bti GBJ002

de Boever, P.; Ilyin, V.; Mahillon, J.; Mergeay, M.

392

Transformation of Acetobacter xylinum with plasmid DNA by electroporation.  

Science.gov (United States)

Genetic analysis of Acetobacter xylinum, a cellulose-synthesizing bacterium, has been limited by lack of a successful transformation method. Transformation of A. xylinum was attempted using two broad-host-range plasmids (pUCD2 and pRK248) and a variety of transformation methods. Methods using CaCl2, freeze/thaw treatments, and polyethylene glycol were unsuccessful. Transformation of a cellulose-negative strain of A. xylinum with plasmid DNA has been achieved with high-voltage electroporation. Electroporation conditions of 25 microF capacitance, 2.5 kV, 400 ohms resistance, and pulse lengths of 6-8 ms were applied to a cell/DNA mixture in a 0.2-cm cuvette. Plasmid pUCD2 transformed at an efficiency of 10(6)-10(7) transformants/micrograms DNA and pRK248 yielded 10(5) transformants/micrograms DNA. The frequency of transformation increased linearly with increasing DNA concentration, while transformation efficiency remained constant. pUCD2 was recovered from transformants following chloramphenicol amplification and observed by agarose gel electrophoresis. Both plasmids could be reisolated from Escherichia coli after back-transformation with alkaline lysis DNA preparations from Acetobacter transformants. Electro-transformation of A. xylinum with plasmid DNA suggests its potential use for analysis of the A. xylinum genome. PMID:1461938

Hall, P E; Anderson, S M; Johnston, D M; Cannon, R E

1992-11-01

393

Dcm methylation is detrimental to plasmid transformation in Clostridium thermocellum  

Energy Technology Data Exchange (ETDEWEB)

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.

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

394

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

OpenAIRE

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 inter...

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

2014-01-01

395

Complete Sequence of a blaKPC-Harboring Cointegrate Plasmid Isolated from Escherichia coli.  

Science.gov (United States)

Horizontal transfer of blaKPC-harboring plasmids contributes significantly to the inter- and intraspecies spread of Klebsiella pneumoniae carbapenemase (KPC). Here we report the complete nucleotide sequence of a blaKPC-harboring IncFIA plasmid, pBK32533, from Escherichia coli. pBK32533 is a cointegrate plasmid comprising of a 72-kb sequence identical to that of the nonconjugative pBK30661 plasmid plus an additional 170-kb element that harbors the genes for plasmid transfer. pBK32533 demonstrates how blaKPC can be spread from a nonconjugative plasmid through cointegration. PMID:25753632

Chavda, Kalyan D; Chen, Liang; Jacobs, Michael R; Rojtman, Albert D; Bonomo, Robert A; Kreiswirth, Barry N

2015-05-01

396

Development of a new shuttle plasmid system for Escherichia coli and Clostridium perfringens.  

OpenAIRE

We constructed a 7.9-kilobase-pair recombinant shuttle plasmid, designated pHR106, by combining desired segments of three plasmids: an Escherichia coli plasmid (pSL100) which provides a multiple cloning site, a Clostridium perfringens plasmid (pJU122) which provides a clostridial origin of replication, and an E. coli plasmid (pJIR62) which provides an E. coli origin of replication, an ampicillin resistance gene, and a chloramphenicol resistance gene of clostridial origin. The shuttle plasmid ...

Roberts, I.; Holmes, W. M.; Hylemon, P. B.

1988-01-01

397

Enhancing Mutual Respect among Nursing Assistants, Residents, and Residents' Families.  

Science.gov (United States)

Interviewed nursing assistants (n=40) and nursing facility residents (n=37) regarding ways they experienced respect, disrespect, attachment, and distancing in their relationships with each other. As a result of finding evidence of disrespect, an inservice session on gaining respect as a nursing assistant was presented. (ABL)

Heiselman, Terry; Noelker, Linda S.

1991-01-01

398

Plasmid-Driven Formation of Influenza Virus-Like Particles  

Science.gov (United States)

We established a plasmid-based system for generating infectious influenza virus-like particles entirely from cloned cDNAs. Human embryonic kidney cells (293T) were transfected with plasmids encoding the influenza A virus structural proteins and with a plasmid encoding an influenza virus-like viral RNA (vRNA) which contained an antisense copy of the cDNA for green fluorescence protein (GFP) flanked by an RNA polymerase I promoter and terminator. Intracellular transcription of the latter construct by RNA polymerase I generated GFP vRNA that was packaged into influenza virus-like particles. This system, which produced more than 104 infectious particles per ml of supernatant, would be useful in studies of influenza virus replication and particle formation. It might also benefit efforts in vaccine production and in the development of improved gene therapy vectors. PMID:10590147

Neumann, Gabriele; Watanabe, Tokiko; Kawaoka, Yoshihiro

2000-01-01

399

Fingerprinting of Flavobacterium psychrophilum isolates by ribotyping and plasmid profiling.  

Science.gov (United States)

Flavobacterium psychrophilum is the agent of cold-water disease and rainbow trout fry syndrome in salmonid fish worldwide. Ribosomal RNA gene restriction patterns (ribotypes) and plasmid profiles were determined on a collection of 85 strains isolated from different countries and fish species. Several ribotypes were obtained by using the restriction endonucleases Hinc II and Pvu II. Computer analysis of the ribotypes revealed that some of them were clearly associated with the fish species from which the strains were isolated, whereas no correlation with the geographical origin was found. Most of the strains harboured at least one plasmid and several different plasmid profiles were observed, even among strains sharing the same ribotype. These methods, used alone or in combination with other typing techniques, can be considered powerful tools for the epidemiological tracing of F. psychrophilum infections. PMID:9841121

Chakroun, C; Grimont, F; Urdaci, M C; Bernardet, J F

1998-07-30

400

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

Science.gov (United States)

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

Ismail, Emadeldeen; Blom, Jochen; Bultreys, Alain; Ivanovi?, Milan; Obradovi?, Aleksa; van Doorn, Joop; Bergsma-Vlami, Maria; Maes, Martine; Willems, Anne; Duffy, Brion; Stockwell, Virginia O; Smits, Theo H M; Pu?awska, Joanna

2014-12-01

401

Genetic characterization of plasmid pRJ5 of Staphylococcus aureus compared to plasmid pE194  

International Nuclear Information System (INIS)

The pRJ5, a naturally occurring constitutive macrolide, lincosamide and streptogramin B (MLS) resistance plasmid of Staphylococcus aureus, was compared to pE194, a plasmid that confers the inducible phenotype. pRJ5 was stable in all strains of S. aureus tested, even under growth at 43O C, which distinguished it from pE194 which was shown to be thermo-sensitive for replication. pRJ5, like pE194, was highly unstable in Bacillus subtilis when the cells were grown in nonselective conditions. Multimeric forms of pRJ5 DNA were detected in the few cells of B. subtilis that retained this plasmid. pE194 was transduced by phages ? 11 and ? 443 at frequencies 400 and 20-fold higher, respectively, than pRJ5. Both plasmids were co-transduced with the plasmid pRJ4. pRJ5 was shown to be compatible with pE194. Therefore they belong to distinct Inc groups. Hybridization studies revealed that pRJ5 shares a 1.35 kb region of homology to pE194, which is limited to the erm gene, conferring MLS resistance. (author)

402

The Emotional Intelligence of Resident Physicians  

OpenAIRE

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...

Mckinley, Sophia Kim

2014-01-01

403

Genetic transformation of a clinical (genital tract), plasmid-free isolate of Chlamydia trachomatis: engineering the plasmid as a cloning vector.  

Science.gov (United States)

Our study had three objectives: to extend the plasmid-based transformation protocol to a clinical isolate of C. trachomatis belonging to the trachoma biovar, to provide "proof of principle" that it is possible to "knock out" selected plasmid genes (retaining a replication competent plasmid) and to investigate the plasticity of the plasmid. A recently developed, plasmid-based transformation protocol for LGV isolates of C. trachomatis was modified and a plasmid-free, genital tract C. trachomatis isolate from Sweden (SWFP-) was genetically transformed. Transformation of this non-LGV C. trachomatis host required a centrifugation step, but the absence of the natural plasmid removed the need for plaque purification of transformants. Transformants expressed GFP, were penicillin resistant and iodine stain positive for accumulated glycogen. The transforming plasmid did not recombine with the host chromosome. A derivative of pGFP::SW2 carrying a deletion of the plasmid CDS5 gene was engineered. CDS5 encodes pgp3, a protein secreted from the inclusion into the cell cytoplasm. This plasmid (pCDS5KO) was used to transform C. trachomatis SWFP-, and established that pgp3 is dispensable for plasmid function. The work shows it is possible to selectively delete segments of the chlamydial plasmid, and this is the first step towards a detailed molecular dissection of the role of the plasmid. The 3.6 kb ?-galactosidase cassette was inserted into the deletion site of CDS5 to produce plasmid placZ-CDS5KO. Transformants were penicillin resistant, expressed GFP and stained for glycogen. In addition, they expressed ?-galactosidase showing that the lacZ cassette was functional in C. trachomatis. An assay was developed that allowed the visualisation of individual inclusions by X-gal staining. The ability to express active ?-galactosidase within chlamydial inclusions is an important advance as it allows simple, rapid assays to measure directly chlamydial infectivity without the need for plaquing, fluorescence or antibody staining. PMID:23527131

Wang, Yibing; Kahane, Simona; Cutcliffe, Lesley T; Skilton, Rachel J; Lambden, Paul R; Persson, Kenneth; Bjartling, Carina; Clarke, Ian N

2013-01-01

404

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

Science.gov (United States)

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 conditions for agriculture. Areas of ancient civilizations (Babylonia, Mesopotamia, Greece) always are concentrated near zones of high seismic activity. Catastrophic earthquakes occurred with interval about 200-500 years, and memory of population was limited usually by duration of 2-3 generations, i.e. by interval 50-80 years. The proposed hypothesis of exposed latitudinal zones at the Earth as pulsating geoid may present nowadays basic interest. References. 1.Ben-Zion Y. Earthquake physics and seismic hazard. 8-th Alexander von Humboldt International Conference. EGU Series. Natural Disasters, Global Change, and the Preservation of World Heritage Sites. Cusco. Peru. 2012. P.14. 2.Sun W. Seismic energy distribution in latitude and a possible tidal stress explanation // Physics of the Earth and Planetary Interiors. 1992. Vol. 71. P. 205-216. 3.Levin B.W., Sasorova E.V. Latitudinal distribution of earthquakes in the Andes and its peculiarity. Advances in Geosciences. 2009. 22. 139-145. www.adv.geosci.net/22/139/2009/ 4.Levin B.W., Sasorova E.V. Seismicity of the Pacific region: global feature detection. - M.: Janus-K. 2012. 308 p. 5.Veronnet, Alex. Rotation de l'ellipsoide hétérogène et figure exacte de la Terre. Journal de mathématiques pures et appliquées. 1912. 6e série, tome 8, p. 331-463.

Levin, Boris; Sasorova, Elena; Domanski, Andrej

2013-04-01

405

High-power optical coatings for a mega-joule class ICF laser  

International Nuclear Information System (INIS)

As a consequence of advancements in Inertial Confinement Fusion research, LLNL is developing plans for a new 1.5 to 2 mega-joule solid-state Nd:glass laser designed to achieve fusion ignition. The new design is possible in part due to advances in optical coatings suitable for high power laser systems. High damage threshold mirrors and polarizers are comprised of electron beam deposited dielectric multilayers. Subthreshold illumination, or laser conditioning, of the multilayer coatings results in an increase in the damage thresholds by factors of 2 to 3 at 1.06?m, thus meeting the fluence requirements of the advanced architecture. For anti-reflective coatings, protective organic coatings for non-linear crystals and phase plates for beam smoothing, sol-gel films provide high damage thresholds coatings at low cost

406

MEGA: An experiment to search for ? ? e? at the level of 10-13  

International Nuclear Information System (INIS)

This report describes the status of the MEGA experiment, which is a search for the decay ? ? e? with a branching ratio sensitivity of approximately 10-13. The observation of this decay would contradict the empirically established rule of lepton family number conservation and would indicate the existence of physics outside the standard model of electroweak interactions. The experimental design employs highly modular, fast detectors, state-of-the-art electronics, and a staged trigger with online filters. The detectors are contained in a 15 kG solenoidal field produced by a superconducting magnet. Positrons are confined to the central region and are measured by a set of thin MWPCs. Photons are measured by one of four layers of pair spectrometers in the outer region. Most aspects of the detector design have been validated in engineering runs; data taking will begin in 1990 with the electron arm and one pair spectrometer layer installed. 9 refs., 1 fig

407

La Organización Mundial de Comercio, los acuerdos mega-regionales y los usos estratégicos del regionalismo  

Directory of Open Access Journals (Sweden)

Full Text Available La parálisis de la Ronda Doha, el desarrollo de grandes negociaciones “mega-regionales” y la proliferación de acuerdos preferenciales han avivado los debates sobre la gobernanza del comercio internacional. Mientras que una interpretación benévola sobre estos acuerdos parece estar ganando lugar, en este artículo sostenemos que los atributos del “regionalismo del siglo XXI” son menos novedosos que lo que se insinúa; y que existe una notable continuidad en los incentivos y las características del “nuevo regionalismo” de los noventa y el llamado “regionalismo del siglo XXI”. Afirmamos que aun cuando los componentes discriminatorios de estos regionalismos hayan sido atenuados por el contenido y naturaleza de la agenda regulatoria, el conflicto básico entre las dos modalidades de gobernanza del régimen de comercio internacional sigue vigente.

Roberto Bouzas

2014-01-01

408

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

International Nuclear Information System (INIS)

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

409

Direct-drive shock-ignition for the Laser MegaJoule  

International Nuclear Information System (INIS)

We present a review of direct-drive shock ignition studies done as an alternative for the Laser MegaJoule (LMJ). One and two dimensional systematic analyses of HiPER-like shock-ignited target designs are performed for the fuel assembly irradiation uniformity using the whole LMJ configuration or a part of the facility, and for the uniformity of the ignitor spike. High-gain shock-ignition is shown to be possible with intensity of each quad less than 1015 W/cm2 but low modes asymmetries displace the power required in the ignitor spike towards higher powers. Shock-ignition of Direct-Drive Double-Shell non-cryogenic targets is also addressed. (authors)

410

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

411

Locked on course: Hydro-Quebec`s commitment to mega-projects  

Energy Technology Data Exchange (ETDEWEB)

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.

Maxwell, J.; Briscoe, F.; Suzuki, Tatsujiro [Massachusetts Inst. of Tech., Cambridge, MA (United States); Lee, J.; Stewart, A.

1997-01-01

412

ADAPTION OF “MEGA EVENT IMPACT SCALE”: VALIDITY AND RELIABILITY STUDY (2011 ERZURUM 25. WINTER UNIVERSIADE  

Directory of Open Access Journals (Sweden)

Full Text Available This study aims at carrying out validity and reliability studies and the adaption of Turkish version of the scale titled “Mega Event Impact Scale” and developed by Jie ve Yan (2010. The scale, which consists of five-point Likert scale 42 items, was administered to the local audience following 2011 Erzurum 25. Winter Universiade. The subjects of the study were 412 people (55 % male and 45 % female, who were chosen through random sampling method. Explanatory factor analysis, applied to determine construct validity of the scale, revealed a construct with 36 items and 8 factors. The internalconsistency reliability coefficient for the whole study was found 0.917. The findings showed that internal consistency reliability of factor items had an item / total correlation coefficient ranging between 0.50 and 0.85. The results were discussed in terms of the validity and reliability of the Turkish version of the scale.

Kerem Y?ld?r?m ?im?ek

2012-05-01

413

The first light of Mini-MegaTORTORA wide-field monitoring system  

CERN Document Server

Here we describe the first light of the novel 9-channel wide-field optical monitoring system with sub-second temporal resolution, Mini-MegaTORTORA, which is being tested now at Special Astrophysical Observatory on Russian Caucasus. The system is able to observe the sky simultaneously in either wide (~900 square degrees) or narrow (~100 square degrees) fields of view, either in clear light or with any combination of color (Johnson B, V or R) polarimetric filters installed, with exposure times ranging from 100 ms to 100 s. The primary goal of the system is the detection of rapid -- with sub-second characteristic time-scales -- optical transients, but it may be also used for studying the variability of the sky objects on longer time scales.

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

2014-01-01

414

[Cavum vergae, cyst of cavum septi pellucidi, mega cisterna magna, and general fibrosis syndrome].  

Science.gov (United States)

One family of 17 cases of general fibrosis syndrome was reported. Four out of five patients examined with CT and/or MRI revealed cavum vergae or cyst of the cavum septi pellucidi or mega cisterna magna, which were characterized by existing on the midline of the brain. The patient with cavum vergae had also platybasia. In one patient, surgical correction of vertical deviation and blepharoptosis of both eyes was performed. There was abnormal insertion of the superior and inferior rectus muscles in posterior and nasal direction, and adhesion of the superior oblique muscle to the superior rectus muscle at the point of it's insertion was found in both eyes. Histopathological findings of the extraocular muscles of two patients showed mixture of relatively normal muscle tissues and vast amounts of collagen fibers. Electron microscopically many glycogen granules were found in muscle fibers. From these findings, this syndrome may be based on failure in development and differentiation. PMID:2220498

Nakajima, T; Namishima, S; Takahashi, K; Aonuma, H; Nitta, C; Abe, Y

1990-05-01

415

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

Directory of Open Access Journals (Sweden)

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.

Hershey H. Friedman

2014-09-01

416

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

International Nuclear Information System (INIS)

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

417

Mega-ampere ion currents and nuclear reactions in the focal laser spot  

International Nuclear Information System (INIS)

The plasma response to a picosecond multiterawatt laser-pulse is characterized by several distinctly different time scales. In the present paper we consider the plasma evolution on the slow time scale typical for excitations of the ionic component. A relativistically strong laser pulse (1018-1019 W/cm2) is shown to drive, under proper conditions, mega-ampere ion currents with typical ion energies of 50-150 keV. This feature of the ultra-intense laser-plasma interaction may be of interest for nuclear fusion since the ion energy involved is close to the resonance peak of the cross-section for the D-T reaction

418

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

International Nuclear Information System (INIS)

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)

419

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

International Nuclear Information System (INIS)

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 1019 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 ?Sv per shot which is fully compatible with radiation level limits.

420

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

421

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

International Nuclear Information System (INIS)

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

422

Overview of the ARGOS X-ray framing camera for Laser MegaJoulea)  

Science.gov (United States)

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.

Trosseille, C.; Aubert, D.; Auger, L.; Bazzoli, S.; Beck, T.; Brunel, P.; Burillo, M.; Chollet, C.; Gazave, J.; Jasmin, S.; Maruenda, P.; Moreau, I.; Oudot, G.; Raimbourg, J.; Soullié, G.; Stemmler, P.; Zuber, C.

2014-11-01

423

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

Science.gov (United States)

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. PMID:25430196

Trosseille, C; Aubert, D; Auger, L; Bazzoli, S; Beck, T; Brunel, P; Burillo, M; Chollet, C; Gazave, J; Jasmin, S; Maruenda, P; Moreau, I; Oudot, G; Raimbourg, J; Soullié, G; Stemmler, P; Zuber, C

2014-11-01

424

Leading by Metaphors –A Case Study of a Mega IT Project in a Danish Bank  

DEFF Research Database (Denmark)

Contrary to the existing literature and studies of large-scale IT projects, empirical data from a mega IT project in mid-sized Danish Bank, Jyske Bank, demonstrates a successful implementation of a highly complex IT platform transition. Linguistic representations and especially extensive use of metaphors by executive management to form and shape the megaproject appeared to have significant impact on guidance of individual and collective action, and thereby presumably one of the important factors for the successful implementation. To learn from this case study, we investigate the use of metaphors in the megaproject and discuss how leading by metaphors are enacted. Our findings are that (1) storytelling with metaphors can act as backbone for communication, (2) metaphors can set direction for technical capabilities, and finally (3) metaphors can be used to emphasize emotional intelligence.

Svejvig, Per; Fladkjær Nielsen, Anne-Dorte

2014-01-01

425

Plasmid vector with temperature-controlled gene expression  

Energy Technology Data Exchange (ETDEWEB)

In plasmid pBR327, a fragment 169 b.p. long including promotor p/sub 3/ 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 lambda 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 42/sup 0/C leads to an almost 100-fold increase in the amount of product of the bla gene as compared with that at 32/sup 0/C. The possibility of the use of plasmid cPE119 for the expression of other genes has been demonstrated for the case of the semisynthetic ..beta..-galactosidase gene of E. coli. In this case, on induction of the cells with recombinant plasmid pCEZ12 for 3 hours at 42/sup 0/C, a 300-fold increase in the amount of active ..beta..-galactosidase, as compared with that at 32/sup 0/C, was observed. It is important to point out that under these conditions (at 42/sup 0/C), at least 99% of the cells containing the plasmid retain the phenotype lacZ/sup +/, which indicates the stability of the proposed vector system

Kravchenko, V.V.; Yamshchikov, V.F.; Pletnev, A.G.

1986-02-01

426

The 2007 Bengkulu Earthquake Series in the Context of Mega-Ruptures off South Sumatra  

Science.gov (United States)

We present a seismological and tectonic study of the 2007 Bengkulu series, including an evaluation of the source characteristics of the main three events based on quasi-real time estimators, including the Energy-to-Moment parameter THETA, which suggests a trend towards slowness for the main shock at 11:10 UTC. While the earthquakes took place within the fault area of the great 1833 earthquake, in the probable context of Coulomb stress transfer from the 2004 and 2005 events, the mainshock and its immediate aftershocks define a faulting area significantly smaller than that of the 1833 event, and a preliminary review of plate kinematic models also suggests that the 2007 shock did not release the full strain accumulated since 1833. This is also supported by the seismic moment of the Bengkulu event (5E28 dyn*cm), and by preliminary modeling of the moderate near field tsunami (see Borrero et al., this session). In this context, we address the question of how much slip remains to be released along the 1833 rupture zone and to the South of it, and more generally of the ability for a large, but not gigantic event, to act as a barrier to the propagation of rupture during a future mega-earthquake. Namely, do the 2007 events preclude the future occurrence of a mega-earthquake whose rupture would over-ride the Bengkulu fault area? Historical records in Central and South Peru, as well as the over-riding by the 2004 Sumatra rupture of the 1881 Car Nicobar fault zone, would suggest a "cautiously negative" answer, casting a pessimistic note on far-field tsunami risk for the Southwestern Indian Ocean. ~

Okal, E. A.; Ebeling, C. W.; Stein, S.; Synolakis, C. E.

2007-12-01

427

Sustainable Housing, Population Growth and Poverty: The Implications on Lagos Mega City  

Directory of Open Access Journals (Sweden)

Full Text Available When people affected by poverty are unable to lead a decent life, there is no doubt that there will be a decay of the city. And when there are inadequate and unfit housing, the condition of the environment often result to slums and ghettos, there will be the disaster of homelessness, unplanned and sprawl nature of city growth. The magic year had the consolation slogan of “housing for all by the year 2000” but this has since changed to the hard fact of “ what Nigerians failed to realize is that housing is a thing that every family would need to provide for itself.” The era of subsidy is gone and this reality has raised a lot of pertinent questions especially on where lies the hope for the poor in a mega city? The phenomenal growth of our towns and cities has given rise to conurbation and metropolitan areas, with various planning problems such as traffic congestion, slum, shanty towns, waste management, housing, pollution, poverty and several others. There is no doubt that the impact of rapid population growth on housing development in a developing economy is usually a consequence of the push of the rural areas and the pull of the town. There is always an upsurge and conglomeration of people in city centres with the resultant effects on housing growth arising from acute unemployment. This growth and physical expansion of cities have been accompanied by unplanned urban sprawl, environmental pollution, deterioration, deficiencies in modern basic facilities, and general urban decay. As increased poverty and urbanization exert more pressures on urban facilities, most Nigerian cities tend to have lost their original dignity, social cohesion and administrative efficiency.This paper therefore revealed the consequences of the problems of urbanization in Lagos, it focuses on the spatial growth and the rapid rate of development in Metropolitan Lagos in order to show the significance and the role of public-private-partnership in the Mega City. 

Ola E. Aluko

2011-08-01

428

DNA sequence analysis of plasmids from multidrug resistant Salmonella enterica serotype Heidelberg isolates.  

Science.gov (United States)

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. PMID:23251446

Han, Jing; Lynne, Aaron M; David, Donna E; Tang, Hailin; Xu, Joshua; Nayak, Rajesh; Kaldhone, Pravin; Logue, Catherine M; Foley, Steven L

2012-01-01

429

Supercoiling, knotting and replication fork reversal in partially replicated plasmids  

OpenAIRE

To study the structure of partially replicated plasmids, we cloned the Escherichia coli polar replication terminator TerE in its active orientation at different locations in the ColE1 vector pBR18. The resulting plasmids, pBR18-TerE@StyI and pBR18-TerE@EcoRI, were analyzed by neutral/neutral two-dimensional agarose gel electrophoresis and electron microscopy. Replication forks stop at the Ter-TUS complex, leading to the accumulation of specific replication intermediates with a mass 1.26 times...

Olavarrieta, Leticia; Marti?nez-robles, Mari?a Luisa; Sogo, Jose?; Stasiak, Andrzej Z.; Hernandez, Pablo; Krimer, Dora B.; Schvartzman, Jorge Bernardo

2002-01-01

430

Association of lupin mitochondrial plasmid DNA with mitochondrial protein  

International Nuclear Information System (INIS)

Lupinus albus mitochondrial plasmids and Lupinus mitochondrial and total proteins have been used for studying the formation of complexes by gel retardation and UV crosslinking assays. All the results suggest formation of a specific complex between mitochondrial plasmids and proteins. Lupinus albus mitochondrial proteins recovered from the complex and resolved by two-dimensional gel electrophoresis (2-D SDS-PAGE) displayed a pI of about 5.6 and 5.8 and a molecular weight of 30 and 31 kDa. (author)

431

Plasmid-Encoded Tet B Tetracycline Resistance in Haemophilus parasuis  

OpenAIRE

The complete sequence of two plasmids, pHS-Tet (5.1 kb) and pHS-Rec (9.5 kb), isolated from Haemophilus parasuis strain HS1543 has been obtained. Plasmid pHS-Tet contains four open reading frames including a tet(B) tetracycline resistance gene which unusually did not have an associated tetR repressor gene. From a total of 45 H. parasuis isolates surveyed (15 international reference strains, 15 field isolates selected for their genetic diversity, and 15 recent Australian field isolates), 2 tet...

Lancashire, John F.; Terry, Tamsin D.; Blackall, P. J.; Jennings, Michael P.

2005-01-01

432

Recombination sites in plasmid drug resistance gene amplification.  

OpenAIRE

The resistance plasmid NR1 derivative pRR330 consists of a neomycin-kanamycin resistance gene (neo-kan) flanked by directly repeated sequences of both insertion element IS1 DNA (768 base pairs) and 840 base pairs of DNA which are a part of the chloramphenicol acetyltransferase (cam) gene. Most Escherichia coli cell populations that were cultured in high neomycin concentrations carried plasmids whose neo-kan gene amplification was mediated either by IS1 DNA or by cam DNA as homologous recombin...

Peterson, B. C.; Rownd, R. H.

1985-01-01

433

Restriction Fragment Length Polymorphisms of Virulence Plasmids in Rhodococcus equi  

OpenAIRE

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 dige...

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

434

Evaluation of in Ovo Delivery System for Plasmid DNA Vaccination  

OpenAIRE

In ovo vaccination against Marek`s Disease Virus (MDV) is a common practice in more than 85% of broilers produced in the US. DNA vaccines represent a new tool to prevent infectious diseases in many species, including poultry. An in ovo delivery system for plasmid DNA vaccines is described in which we evaluate the route of delivery (air cell vs amniotic cavity), transfection reagent (IFA+DMSO vs polyethylenimine), dose of plasmid DNA (1 to 100 µg/egg) and the nature of humoral immune response...

Moura, L.; Liu, M.; Vakharia, V. N.

2007-01-01

435

Conjugative plasmids harboring tet(W) and tet(M) involved in the transfer of tetracycline resistance.  

Czech Academy of Sciences Publication Activity Database

Santander : International Society for Plasmid Biology, 2012. [International Plasmid Biology Conference 2012. 12.09.2012-16.09.2012, Santander] Institutional support: RVO:60077344 Keywords : conjugative plasmids harboring * tetracycline resistance Subject RIV: EH - Ecology, Behaviour

Kyselková, Martina; Kopejtka, Karel; Volná, Lucie; Bhumibhamon, G.; Chro?áková, Alica; Jirout, Ji?í; Schmitt, H.; Heuer, H.; Smalla, K.; Elhottová, Dana

436

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

International Nuclear Information System (INIS)

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)

437

Transcription of ColE1Ap mbeC induced by conjugative plasmids from twelve different incompatibility groups.  

OpenAIRE

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...

Selvaratnam, S.; Gealt, M. A.

1993-01-01

438

Transcriptional profiling of human epithelial cells infected with plasmid-bearing and plasmid-deficient Chlamydia trachomatis.  

Science.gov (United States)

Chlamydia trachomatis is an obligate intracellular epitheliotropic bacterial pathogen of humans. Infection of the eye can result in trachoma, the leading cause of preventable blindness in the world. The pathophysiology of blinding trachoma is driven by multiple episodes of reinfection of conjunctival epithelial cells, producing an intense chronic inflammatory response resulting in submucosal tissue remodeling and scarring. Recent reports have shown that infection with trachoma organisms lacking the cryptic chlamydial plasmid is highly attenuated in macaque eyes, a relevant experimental model of human trachoma infection. To better understand the molecular basis of plasmid-mediated infection attenuation and the potential modulation of host immunity, we conducted transcriptional profiling of human epithelial cells infected with C. trachomatis plasmid-bearing (A2497) and plasmid-deficient (A2497P(-)) organisms. Infection of human epithelial cells with either strain increased the expression of host genes coding for proinflammatory (granulocyte-macrophage colony-stimulating factor [GM-CSF], macrophage colony-stimulating factor [MCSF], interleukin-6 [IL-6], IL-8, IL-1?, CXCL1, CXCL2, CXCL3, intercellular adhesion molecule 1 [ICAM1]), chemoattraction (CCL20, CCL5, CXCL10), immune suppression (PD-L1, NFKB1B, TNFAIP3, CGB), apoptosis (CASP9, FAS, IL-24), and cell growth and fibrosis (EGR1 and IL-20) proteins. Statistically significant increases in the levels of expression of many of these genes were found in A2497-infected cells compared to the levels of expression in A2497P(-)-infected cells. Our findings suggest that the chlamydial plasmid plays a focal role in the host cell inflammatory response to infection and immune avoidance. These results provide new insights into the role of the chlamydial plasmid as a chlamydial virulence factor and its contributions to trachoma pathogenesis. PMID:25404022

Porcella, Stephen F; Carlson, John H; Sturdevant, Daniel E; Sturdevant, Gail L; Kanakabandi, Kishore; Virtaneva, Kimmo; Wilder, Hannah; Whitmire, William M; Song, Lihua; Caldwell, Harlan D

2015-02-01

439

On conjugative plasmids: mathematical models of their population dynamics and population genetics  

OpenAIRE

in this thesis several mathematical models are formulated to analyse the population dynamics of plasmids. Furthermore it is investigated how selection affects the characteristics of the population dynamics of plasmids. ... Zie: Summary and general conclusions

Hoeven, Nelly

1985-01-01

440

Conjugal transfer of group B streptococcal plasmids and comobilization of Escherichia coli-Streptococcus shuttle plasmids to Lactobacillus plantarum.  

OpenAIRE

The antibiotic resistance group B streptococcal plasmids, pIP501 and pVA797, were conjugally transferred from Streptococcus faecalis to Lactobacillus plantarum. The Escherichia coli-Streptococcus shuttle plasmids, pVA838 and pSA3, were mobilized from S. sanguis to L. plantarum by pVA797 via cointegrate formation. pVA838 readily resolved from pVA797 and was present in L. plantarum as deletion derivatives. The pVA797::pSA3 cointegrate failed to resolve in L. plantarum.

Shrago, A. W.; Dobrogosz, W. J.

1988-01-01

441

The resolution and regeneration of a cointegrate plasmid reveals a model for plasmid evolution mediated by conjugation and oriT site-specific recombination.  

Science.gov (United States)

Cointegrate plasmids are useful models for the study of plasmid evolution if their evolutionary processes can be replicated under laboratory conditions. pBMB0228, a 17?706?bp native plasmid originally isolated from Bacillus thuringiensis strain YBT-1518, carries two nematicidal crystal protein genes, cry6Aa and cry55Aa. In this study, we show that pBMB0228 is in fact a cointegrate of two plasmids and contains two functional replication regions and two functional mobilization regions. Upon introduction into B.?thuringiensis strain BMB171, pBMB0228 spontaneously resolves into two constituent plasmids via recombination at its oriT1 and oriT2 sites. The resolution does not require conjugation but can be promoted by conjugation. We further confirm that the resolution is mediated by oriT site-specific recombination requiring Mob02281 or Mob02282. Additionally, the two constituent plasmids of pBMB0228 are mobilizable, and can fuse back via oriT site-specific integration after entering into the same cell by conjugation. Our study confirms that native plasmid can reversibly interconvert between a cointegrate structure and its constituent plasmids. This study provides insight into the evolution of cointegrate plasmids, linking plasmid evolution with conjugation and the oriT site-specific recombination function of relaxase. PMID:23826996

Wang, Pengxia; Zhang, Chunyi; Zhu, Yiguang; Deng, Yun; Guo, Suxia; Peng, Donghai; Ruan, Lifang; Sun, Ming

2013-12-01

442

Rapid plasmid library screening using RecA-coated biotinylated probes.  

OpenAIRE

A method for the rapid physical isolation of recombinant plasmids of interest from a mixture of plasmids such as a plasmid cDNA library is presented. This method utilizes the ability of RecA protein to form stable complexes between linear single-stranded and circular double-stranded DNA molecules sharing sequence homology, and procedures allowing isolation of biotinylated nucleic acid. Biotinylated linear DNA probes coated with RecA have been used to screen reconstituted plasmid libraries con...

Rigas, B.; Welcher, A. A.; Ward, D. C.; Weissman, S. M.

1986-01-01

443

Repressor titration: a novel system for selection and stable maintenance of recombinant plasmids.  

OpenAIRE

The propagation of recombinant plasmids in bacterial hosts, particularly in Escherichia coli, is essential for the amplification and manipulation of cloned DNA and the production of recombinant proteins. The isolation of bacterial transformants and subsequent stable plasmid maintenance have traditionally been accomplished using plasmid-borne selectable marker genes. Here we describe a novel system that employs plasmid-mediated repressor titration to activate a chromosomal selectable marker, r...

Williams, S. G.; Cranenburgh, R. M.; Weiss, A. M.; Wrighton, C. J.; Sherratt, D. J.; Hanak, J. A.

1998-01-01

444

IncA/C plasmids: An emerging threat to human and animal health?  

OpenAIRE

Incompatibility group IncA/C plasmids are large, low copy, theta-replicating plasmids that have been described in the literature for over 40 years. However, they have only recently been intensively studied on the genomic level because of their associations with the emergence of multidrug resistance in enteric pathogens of humans and animals. These plasmids are unique among other enterobacterial plasmids in many aspects, including their modular structure and gene content. While the IncA/C plas...

Johnson, Timothy J.; Lang, Kevin S.

2012-01-01

445

Variant mitochondrial plasmids of broad bean arose by recombination and are controlled by the nuclear genome.  

OpenAIRE

Various cytoplasms of broad bean contain three mitochondrial plasmids (mtp1, 2 and 3), previously described. In cytoplasm 350 we have observed several additional mitochondrial plasmids, varying in number and in identity according to the nuclear background. Replacement of the nucleus by backcrossing led to the appearance or disappearance of additional plasmids, indicating that the nuclear genome controls either the creation or the copy level of mitochondrial plasmids. Analysis of eight variant...

Flamand, Marie-christine; Duc, G.; Goblet, J. P.; Hong, L.; Louis, O.; Briquet, Michel; Boutry, Marc

1993-01-01

446

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes  

OpenAIRE

Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured fr...

Brown, Celeste J.; Sen, Diya; Yano, Hirokazu; Bauer, Matthew L.; Rogers, Linda M.; Auwera, Geraldine A.; Top, Eva M.

2013-01-01

447

Isolation and characterization of Pseudomonas aeruginosa R' plasmids constructed by interspecific mating.  

OpenAIRE

Plasmid R68.45 was used to construct R' plasmids carrying a maximum of 4 to 5 map minutes of the Pseudomonas aeruginosa PAO chromosome by interspecific mating, using P. putida PPN as the recipient. These R' plasmids were used to determine the map location of the amiE locus and to identify tentatively a number of P. putida auxotrophic mutations. Some of these R' plasmids could not be maintained in recombination-deficient P. aeruginosa strains.

Morgan, A. F.

1982-01-01

448

A DNA polymerase mutation that suppresses the segregation bias of an ARS plasmid in Saccharomyces cerevisiae.  

OpenAIRE

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...

Houtteman, S. W.; Elder, R. T.

1993-01-01

449

Gene delivery by surface immobilization of plasmid to tissue engineering scaffolds  

OpenAIRE

Biomaterial scaffolds that serve as vehicles for gene delivery to promote expression of inductive factors have numerous regenerative medicine applications. In this report, we investigate plasmid delivery from biomaterial scaffolds using a surface immobilization strategy. Porous scaffolds were fabricated from poly(lactide-co-glycolide) (PLG), and plasmids were immobilized by drying. In vitro plasmid release indicated that the majority (>70%) of adsorbed plasmid was released within 24 hours and...

Salvay, David M.; Zelivyanskaya, Marina; Shea, Lonnie D.

2010-01-01

450

Conservation of Plasmid-Encoded Traits among Bean-Nodulating Rhizobium Species  

OpenAIRE

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...

Brom, Susana; Girard, Lourdes; Garci?a-de Los Santos, Alejandro; Sanjuan-pinilla, Julio M.; Olivares, Jose?; Sanjuan, Juan

2002-01-01

451

Expression of large plasmids in the endosymbiotic form of Rhizobium leguminosarum.  

OpenAIRE

Isolated plasmid DNA from Rhizobium leguminosarum was hybridised with cellular RNA from broth-cultured bacteria and endosymbiotic bacteroids. From these hybridisation, experiments it is concluded that plasmid genes are strongly expressed in bacteroids and only weakly or not at all in bacteria. From the hybridisation of plasmid DNA with the cloned structural nif genes of Klebsiella pneumoniae it is shown that at least part of the nif genes are located on a plasmid.

Krol, A. J. M.; Hontelez, J. G. J.; Bos, R. C.; Kammen, A.

1980-01-01

452

Novel plasmid-mediated beta-lactamase in members of the family Enterobacteriaceae from Ohio.  

OpenAIRE

Epidemiologic studies of plasmid-mediated resistance at the Cleveland Veterans Administration Medical Center revealed that related plasmids had disseminated among members of the family Enterobacteriaceae. We studied the beta-lactamases encoded by these plasmids in Escherichia coli C600 transformants or transconjugants. Substrate and inhibition profiles of the enzymes determined by two of these plasmids suggested an activity resembling TEM-1; however, isoelectric focusing revealed a pI of 7.0....

Shlaes, D. M.; Medeiros, A. A.; Kron, M. A.; Currie-mccumber, C.; Papa, E.; Vartian, C. V.

1986-01-01

453

Analysis of plasmids in nosocomial strains of multiple-antibiotic-resistant Staphylococcus aureus.  

OpenAIRE

Nosocomial infections caused by Staphylococcus aureus strains resistant to methicillin and multiple antibiotics have reached epidemic proportions in Melbourne, Australia, over the past 5 years. Plasmid analysis of representative clinical isolates demonstrated the presence of three classes of plasmid DNA in most strains. Resistance to gentamicin, kanamycin, and tobramycin was usually mediated by an 18-megadalton plasmid but could also be encoded by a related 22-megadalton plasmid. Two distingu...

Lyon, B. R.; May, J. W.; Skurray, R. A.

1983-01-01