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1

Phylogenetic analysis of porcine epidemic diarrhea virus (PEDV) field strains in central China based on the ORF3 gene and the main neutralization epitopes.  

PubMed

Since 2010, porcine epidemic diarrhea has re-emerged with devastating impact on the swine-raising industry in central China. To investigate the epidemic characteristics of PEDV, the complete ORF3 genes of 14 PEDV field strains from central China during 2012 to 2013 were cloned, sequenced and compared with reference strains. Phylogenetic analysis based on the complete ORF3 gene showed that the PEDVs in central China and the reference strains could be divided into three groups: G1, G2, and G3. The 14 PEDV isolates were classified as G1 and showed a close relationship to some Chinese strains isolated previously in central China and differed genetically from recent isolates from southern China, Korean strains (SM98 and DB1865, 2012), the Chinese LZC strain (2007), and the vaccine strain (CV777) being used in China. Our findings suggested that the PEDVs circulating between 2012 and 2013 in central China might have evolved from earlier strains in the local region. To determine the reason for recent vaccination failures, we also studied variations in antigenicity of field strains by analyzing the three neutralizing epitope regions in the S gene. The results showed that the neutralizing epitopes at aa 245-252 were highly conserved, but most of the amino acid changes occurred in the epitope regions aa 7-146 and 271-278. We speculate that the amino acid mutations in the neutralizing epitope regions may be associated with changes in the antigenicity of PEDV and consequently result in vaccination failure. Together, these findings may be useful for understanding the epidemiology of PEDV and may be relevant for designing of new and more efficacious vaccines. PMID:24292967

Li, Renfeng; Qiao, Songlin; Yang, Yanyan; Su, Yunfang; Zhao, Pu; Zhou, Enmin; Zhang, Gaiping

2014-05-01

2

A phage-displayed peptide recognizing porcine aminopeptidase N is a potent small molecule inhibitor of PEDV entry.  

PubMed

Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. These same peptides had no inhibitory effects on infection of Vero cells by porcine epidemic diarrhea virus (PEDV). However, when PEDV, TGEV and porcine pseudorabies virus were incubated with peptide H (HVTTTFAPPPPR), only infection of Vero cells by PEDV was inhibited. Immunofluoresence assays indicated that inhibition of PEDV infection by peptide H was independent of pAPN. Western blots demonstrated that peptide H interacted with PEDV spike protein and that pre-treatment of PEDV with peptide H led to a higher inhibition than synchronous incubation with cells. These results indicate direct interaction with the virus is necessary to inhibit infectivity. Temperature shift assays demonstrated that peptide H inhibited pre-attachment of the virus to the cells. PMID:24889221

Meng, Fandan; Suo, Siqingaowa; Zarlenga, Dante S; Cong, Yingying; Ma, Xiaowei; Zhao, Qiong; Ren, Xiaofeng

2014-05-01

3

Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF 3.  

PubMed

A porcine epidemic diarrhea virus (PEDV) designated DR13 was isolated in Vero cells and serially passaged by level 100. The virus was titrated at regular intervals of the passage level. Open reading frame (ORF) 3 sequences of the virus at passage levels 20, 40, 60, 80, and 100 were aligned and compared using a computer software program. Suitability of the restriction fragment length polymorphism (RFLP) analysis for differentiating the virus from other Korean field strains was investigated. The DR13 field isolate was successively adapted in Vero cells as observed through polymerase chain reaction (PCR) and titration of the virus. RFLP analysis identified change in cleavage sites of HindIII and Xho II from passage levels 75 and 90, respectively; these RFLP patterns of ORF 3 differentiated the Vero cell-adapted virus from its parent strain, DR13, and 12 other strains of PEDV studied. The cell adapted DR13 was tested for its pathogenicity and immunogenicity in piglets and pregnant sows. The results indicated that cell adapted DR13 revealed reduced pathogenicity and induced protective immune response in pigs. Differentiation between highly Vero cell-adapted virus and wild-type virus could be the marker of adaptation to cell culture and a valuable tool for epidemiologic studies of PEDV infections. The results of this study supported that the cell attenuated virus could be applied as a marker vaccine candidate against PEDV infection. PMID:12706667

Song, D S; Yang, J S; Oh, J S; Han, J H; Park, B K

2003-05-16

4

Isolation and Characterization of Porcine Epidemic Diarrhea Viruses Associated with the 2013 Disease Outbreak among Swine in the United States  

PubMed Central

Porcine epidemic diarrhea virus (PEDV) was detected in May 2013 for the first time in U.S. swine and has since caused significant economic loss. Obtaining a U.S. PEDV isolate that can grow efficiently in cell culture is critical for investigating pathogenesis and developing diagnostic assays and for vaccine development. An additional objective was to determine which gene(s) of PEDV is most suitable for studying the genetic relatedness of the virus. Here we describe two PEDV isolates (ISU13-19338E and ISU13-22038) successfully obtained from the small intestines of piglets from sow farms in Indiana and Iowa, respectively. The two isolates have been serially propagated in cell culture for over 30 passages and were characterized for the first 10 passages. Virus production in cell culture was confirmed by PEDV-specific real-time reverse-transcription PCR (RT-PCR), immunofluorescence assays, and electron microscopy. The infectious titers of the viruses during the first 10 passages ranged from 6 × 102 to 2 × 105 50% tissue culture infective doses (TCID50)/ml. In addition, the full-length genome sequences of six viruses (ISU13-19338E homogenate, P3, and P9; ISU13-22038 homogenate, P3, and P9) were determined. Genetically, the two PEDV isolates were relatively stable during the first 10 passages in cell culture. Sequences were also compared to those of 4 additional U.S. PEDV strains and 23 non-U.S. strains. All U.S. PEDV strains were genetically closely related to each other (?99.7% nucleotide identity) and were most genetically similar to Chinese strains reported in 2011 to 2012. Phylogenetic analyses using different genes of PEDV suggested that the full-length spike gene or the S1 portion is appropriate for sequencing to study the genetic relatedness of these viruses.

Chen, Qi; Li, Ganwu; Stasko, Judith; Thomas, Joseph T.; Stensland, Wendy R.; Pillatzki, Angela E.; Gauger, Phillip C.; Schwartz, Kent J.; Madson, Darin; Yoon, Kyoung-Jin; Stevenson, Gregory W.; Burrough, Eric R.; Harmon, Karen M.; Main, Rodger G.

2014-01-01

5

Transverse Magnetic Field Propellant Isolator  

NASA Technical Reports Server (NTRS)

An alternative high voltage isolator for electric propulsion and ground-based ion source applications has been designed and tested. This design employs a transverse magnetic field that increases the breakdown voltage. The design can greatly enhance the operating range of laboratory isolators used for high voltage applications.

Foster, John E.

2000-01-01

6

Expression and Purification of the scFv from Hybridoma Cells Secreting a Monoclonal Antibody Against S Protein of PEDV  

PubMed Central

The variable regions of the heavy chain (VH) and light chain (VL) were amplified by RT-PCR from the hybridoma 6E6, which secretes the monoclonal antibody against PEDV S protein. The VL and VH amplicons were combined using SOE-PCR by a 12 amino acid flexible linker (SSGGGGSGGGGS), which produced the scFv gene (named scFv/6E6). After sequence analysis, the scFv/6E6 gene was cloned into the prokaryotic expression vector pGEX-6p-1 with a GST-tag. The recombinant scFv/6E6 protein was successfully expressed in recombinant Escherichia coli by IPTG induction. Moreover, the recombinant scFv/6E6 protein was purified from the inclusion body form by the gel-cutting measure followed by electroelution and dialysis. The recombinant scFv/6E6 protein reported here will provide some basis for further antiviral drug research based on the scFv molecule.

Zhu, Qinghe; Guo, Donghua; Feng, Li

2013-01-01

7

Magnetic field decay in isolated neutron stars  

Microsoft Academic Search

Three mechanisms that promote the loss of magnetic flux from an isolated neutron star - Ohmic decay, ambipolar diffusion, and Hall drift - are investigated. Equations of motions are solved for charged particles in the presence of a magnetic field and a fixed background of neutrons, while allowing for the creation and destruction of particles by weak interactions. Although these

Peter Goldreich; Andreas Reisenegger

1992-01-01

8

Distributed Field Rotator Composed of Isolated Components  

NASA Astrophysics Data System (ADS)

Transformation optics offers remarkable control over electromagnetic fields and has recently opened an exciting gateway to design 'field rotator devices'. We propose a distributed field rotator with open windows based on composite transformation optics, which consists of a central circular region and several isolated components. The number, position and size of the components can be controlled freely by the design purpose. Full-wave simulations are performed to demonstrate its function, which is equivalent to a classic field rotator. However, such a distributed rotator makes it much easier to access and make use of the rotated field in the central region, compared to the closed classic field rotator, especially in the case of 3D situations.

Liu, Guo-Chang; Li, Chao; Shao, Jin-Jin; Fang, Guang-You

2014-04-01

9

Gradient isolator for flow field of fuel cell assembly  

DOEpatents

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions. 4 figs.

Ernst, W.D.

1999-06-15

10

Gradient isolator for flow field of fuel cell assembly  

DOEpatents

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions.

Ernst, William D. (Troy, NY)

1999-01-01

11

Temperature field in rubber vibration isolators  

NASA Astrophysics Data System (ADS)

The temperature field inside a vibrating rubber solid cylinder is investigated. The rubber cylinder, a specimen of a vibration isolator rubber (Neoprene GR), is subjected to a repeatedly cyclic compressive force by means of an electrodynamic shaker. In the experimental investigation the temperatures at 16 different locations inside the cylinder have been measured by means of copper-constantan thermocouples. After the estimation of the heat generated per unit volume per unit time with the help of the estimated damping and stiffness coefficients of rubber, one can attempt the solution of the heat conduction equation describing the temperature field inside the rubber specimen. The values of the temperature found from the analytical investigation compare fairly well with the experimental measurements.

Abdulhadi, M. Issa

1985-02-01

12

Velocity Field of Isolated Turbulent Puffs  

NASA Astrophysics Data System (ADS)

The velocity field of isolated turbulent puffs was investigated by the PIV technique. Particular attention was paid to the entrainment pattern of isolated puffs. Puffs were generated by injecting seeded air through a 5 mm diameter nozzle into a flow chamber with a weak co-flow. Puffs with a Reynolds number of 5,000 were examined in the range of 35 -- 75 diameters downstream of the nozzle. The injection time was varied in order to assess the effect of injection volume and impulse on the puff structure. The results indicate that as the injection volume increased, puffs elongated in the axial direction. The largest mean and fluctuating velocities were within the central portion of the puff. The maximum turbulent shear stress within the puff was as much as 2.5 times the steady jet value. The vorticity field showed the presence of vorticity throughout the puff volume. The ratio of volume flow rate at the puff center to the steady jet volume flux at the same location was largest for the smallest injection volume. The majority of entrainment into the puff occurs below the puff center while the puff cap pushes out into surrounding fluid.

Ghaem-Maghami, Elham; Johari, Hamid

2006-11-01

13

Isolation, cloning, and pathologic analysis of Trypanosoma evansi field isolates.  

PubMed

In recent years, the emergence of highly pathogenic Trypanosoma evansi strains in the Philippines has resulted in substantial losses in livestock production. In this study, we isolated T. evansi from infected-water buffaloes in the Philippines and analyzed their virulence using mice and cattle. A total of 10 strains of T. evansi were isolated. Evaluation of the virulence of each strain using mice depicted significant differences among the strains in the prepatent period, the level of parasitemia, and the survival time of the infected animals. In mice infected with the highly pathogenic T. evansi, signs of excessive inflammation such as marked splenomegaly and increase more than 6-fold in the number of leukocytes were observed at 8 days post-infection. To study the virulence of the parasite strains in cattle (which are the common T. evansi hosts in Philippines), cattle were infected with the T. evansi isolates that showed high and low virulence in mice. The rate of parasite growth and the length of the prepatent periods were found to be similar to those observed in mice for the respective strains. The cattle infected with the highly pathogenic strain developed anemia and a marked decrease in leukocyte counts. To determine the cause of the pathological changes, we analyzed the expression levels of inflammatory cytokines and observed up-regulation of tumor necrosis factor-? in anemic infected cattle. Our findings suggest that the epidemic of T. evansi in the Philippines is characterized by T. evansi strains with varying virulences from low to very high pathogenicity in cattle. PMID:23354941

Mekata, Hirohisa; Konnai, Satoru; Mingala, Claro N; Abes, Nancy S; Gutierrez, Charito A; Dargantes, Alan P; Witola, William H; Inoue, Noboru; Onuma, Misao; Murata, Shiro; Ohashi, Kazuhiko

2013-04-01

14

Antibiotic susceptibility of Riemerella anatipestifer field isolates.  

PubMed

Kirby-Bauer tests were used to analyze the antibiotic resistance of 224 isolates of Riemerella anatipestifer isolated between 1998 and 2005. Among the 36 antibiotics tested, 50% of the analyzed isolates were resistant to ampicillin, ceftazidime, aztreonam, cefazolin, cefepime, cefuroxime, oxacillin, penicillin G, rifampin, and trimethoprim/sulfamethoxazole. Higher levels of resistance were detected for aztreonam, cefepime, oxacillin, penicillin G, ceftazidime, and trimethoprim/sulfamethoxazole (87.8%, 64.3%, 88.6%, 86.9%, 75.9%, and 79.2% resistance, respectively). The lowest resistance rates were observed for amikacin (9.5%), cefoperazone (7.2%), imipenem (3.2%), and neomycin (9.5%). Four isolates were found to be resistant to 29 different antimicrobials. Riemerella anatipestifer drug resistance profiles changed over time, and the only consistent patterns observed were the resistance of R. anatipestifer to cefoperazone, piperacillin, spectinomycin, and aztreonam. In addition to determining the antibiotic-resistance profiles of R. anatipestifer isolates, we also examine the therapeutic efficacy of these antibiotics against lethal R. anatipestifer infection in ducks in vivo. According to these data, we have extrapolated an antibiotic treatment approach for veterinarians attending flocks of ducks. These data suggest that disk-diffusion analyses can be extrapolated to predict in vivo efficacy, thereby facilitating the identification of effective antibacterial treatments and potentially diminishing the irresponsible use of antibiotics. PMID:20095163

Zhong, Chong Yue; Cheng, An Chun; Wang, Ming Shu; Zhu, De Kang; Luo, Qi Hui; Zhong, Chuan De; Li, Ling; Duan, Ze

2009-12-01

15

In vitro susceptibilities of field isolates of Mycoplasma agalactiae  

Microsoft Academic Search

In order to determine how widespread antibiotic resistance has become to standard treatments, the in vitro susceptibilities of 28 Mycoplasma agalactiae Spanish field isolates to 16 antimicrobial agents were determined using a broth microdilution method. The most effective antimicrobials based on minimum inhibitory concentration (MIC)90 values were fluoroquinolones, tetracyclines and macrolides. Two strains were tetracycline resistant. Streptomycin, erythromycin and nalidixic

N. T. Antunes; M. M. Tavío; P. Assunção; R. S. Rosales; C. Poveda; C. de la Fé; M. C. Gil; J. B. Poveda

2008-01-01

16

Comparative Transcriptional and Genomic Analysis of Plasmodium falciparum Field Isolates  

Microsoft Academic Search

Mechanisms for differential regulation of gene expression may underlie much of the phenotypic variation and adaptability of malaria parasites. Here we describe transcriptional variation among culture-adapted field isolates of Plasmodium falciparum, the species responsible for most malarial disease. It was found that genes coding for parasite protein export into the red cell cytosol and onto its surface, and genes coding

Margaret J. Mackinnon; Jinguang Li; Sachel Mok; Moses M. Kortok; Kevin Marsh; Peter R. Preiser; Zbynek Bozdech

2009-01-01

17

Virulence of South African isolates of Haemophilus paragallinarum. Part 1: NAD-dependent field isolates.  

PubMed

The virulence of four South African field isolates of NAD-dependent Haemophilus paragallinarum, representing the four serovars known to occur in that country, was investigated. During this study an alternative challenge model for infectious coryza was used, in which the infectivity as well the virulence of different isolates could be evaluated. The challenge model consisted of the direct challenge, via intrasinus injection of one chicken in a row of interconnected layer cages, containing 10 chickens, which are subsequently infected by natural routes. A scoring system of the clinical signs was established in which a score is given to the ability of the isolate to produce clinical signs in the challenge birds. The mean daily disease score for the flock can be calculated and plotted on a graph to give a graphic representation of the disease profile. A mean disease score, calculated over a 20-day examination period can be calculated. Isolates can then be compared to each other, either graphically or by a comparison of the mean disease scores. It has been demonstrated using this scoring system that the South African serogroup C isolates appear to be more virulent than the South African serogroup A or B isolates. It was further established that the serovar C-3 isolate appeared to be the most virulent. PMID:12234003

Bragg, R R

2002-06-01

18

Methanococcus thermolithotrophicus Isolated from North Sea Oil Field Reservoir Water  

PubMed Central

Methanococcus thermolithotrophicus ST22 was isolated from produced water of a North Sea oil field, on mineral medium with H(inf2)-CO(inf2) as the sole source of carbon and energy. The isolate grew at 17 to 62(deg)C, with an optimum at 60(deg)C. The pH range was 4.9 to 9.8, with optimal growth at pH 5.1 to 5.9; these characteristics reflected its habitat. Strain ST22 was quickly identified and distinguished from the type strain by immunoblotting.

Nilsen, R. K.; Torsvik, T.

1996-01-01

19

Discovery of an isolated compact elliptical galaxy in the field  

NASA Astrophysics Data System (ADS)

We present the discovery of an isolated compact elliptical (cE) galaxy, found during a search of SDSS DR7 for cE galaxies, and for which we obtained William Herschel Telescope/ACAM imaging. It is ˜900 kpc distant from its nearest neighbour, has an effective r-band radius of ˜500 pc and a B-band mean surface brightness within its effective radius of 19.75 mag arcsec-1. Serendipitous deep SuprimeCam imaging shows that there is no underlying disc. Its isolated position suggests that there is an alternative channel to the stripping scenario for the formation of compact ellipticals. We also report analysis of recent deeper imaging of the previous candidate free-flying cE, which shows that it is, in fact, a normal dwarf elliptical. Hence, the new cE reported here is the first confirmed isolated cE to be found in the field.

Huxor, A. P.; Phillipps, S.; Price, J.

2013-04-01

20

Isolated neuron amplitude spike decrease under static magnetic fields  

NASA Astrophysics Data System (ADS)

Isolated Helix aspersa neurons under strong enough static magnetic fields B (0.07-0.7 T) show a decrease of the spike depolarization voltage of the form ˜exp( ?B2), with ? dependent on neuron parameters. A tentative model is proposed which explains such behaviour through a deactivation of Na +?K +-ATP-ase pumps due to protein superdiamagnetic rotation. Values for the cluster and protein in cluster numbers are estimated.

Azanza, María J.; del Moral, A.

1996-05-01

21

In vitro susceptibilities of field isolates of Mycoplasma agalactiae.  

PubMed

In order to determine how widespread antibiotic resistance has become to standard treatments, the in vitro susceptibilities of 28 Mycoplasma agalactiae Spanish field isolates to 16 antimicrobial agents were determined using a broth microdilution method. The most effective antimicrobials based on minimum inhibitory concentration (MIC)(90) values were fluoroquinolones, tetracyclines and macrolides. Two strains were tetracycline resistant. Streptomycin, erythromycin and nalidixic acid resistance was observed in all strains. PMID:17604191

Antunes, N T; Tavío, M M; Assunção, P; Rosales, R S; Poveda, C; de la Fé, C; Gil, M C; Poveda, J B

2008-09-01

22

Archaeoglobus fulgidus Isolated from Hot North Sea Oil Field Waters  

PubMed Central

A hyperthermophilic sulfate reducer, strain 7324, was isolated from hot (75°C) oil field waters from an oil production platform in the Norwegian sector of the North Sea. It was enriched on a complex medium and isolated on lactate with sulfate. The cells were nonmotile, irregular coccoid to disc shaped, and 0.3 to 1.0 ?m wide. The temperature for growth was between 60 and 85°C with an optimum of 76°C. Lactate, pyruvate, and valerate plus H2 were utilized as carbon and energy sources with sulfate as electron acceptor. Lactate was completely oxidized to CO2. The cells contained an active carbon monoxide dehydrogenase but no 2-oxoglutarate dehydrogenase activity, indicating that lactate was oxidized to CO2 via the acetyl coenzyme A/carbon monoxide dehydrogenase pathway. The cells produced small amounts of methane simultaneously with sulfate reduction. F420 was detected in the cells which showed a blue-green fluorescence at 420 nm. On the basis of morphological, physiological, and serological features, the isolate was classified as an Archaeoglobus sp. Strain 7324 showed 100% DNA-DNA homology with A. fulgidus Z, indicating that it belongs to the species A. fulgidus. Archaeoglobus sp. has been selectively enriched and immunomagnetically captured from oil field waters from three different platforms in the North Sea. Our results show that strain 7324 may grow in oil reservoirs at 70 to 85°C and contribute to hydrogen sulfide formation in this environment. Images

Beeder, Janiche; Nilsen, Roald Kare; Rosnes, Jan Thomas; Torsvik, Terje; Lien, Torleiv

1994-01-01

23

Comparative Transcriptional and Genomic Analysis of Plasmodium falciparum Field Isolates  

PubMed Central

Mechanisms for differential regulation of gene expression may underlie much of the phenotypic variation and adaptability of malaria parasites. Here we describe transcriptional variation among culture-adapted field isolates of Plasmodium falciparum, the species responsible for most malarial disease. It was found that genes coding for parasite protein export into the red cell cytosol and onto its surface, and genes coding for sexual stage proteins involved in parasite transmission are up-regulated in field isolates compared with long-term laboratory isolates. Much of this variability was associated with the loss of small or large chromosomal segments, or other forms of gene copy number variation that are prevalent in the P. falciparum genome (copy number variants, CNVs). Expression levels of genes inside these segments were correlated to that of genes outside and adjacent to the segment boundaries, and this association declined with distance from the CNV boundary. This observation could not be explained by copy number variation in these adjacent genes. This suggests a local-acting regulatory role for CNVs in transcription of neighboring genes and helps explain the chromosomal clustering that we observed here. Transcriptional co-regulation of physical clusters of adaptive genes may provide a way for the parasite to readily adapt to its highly heterogeneous and strongly selective environment.

Mackinnon, Margaret J.; Li, Jinguang; Mok, Sachel; Kortok, Moses M.; Marsh, Kevin; Preiser, Peter R.; Bozdech, Zbynek

2009-01-01

24

Simulations of magnetic fields in isolated disc galaxies  

NASA Astrophysics Data System (ADS)

Magnetic fields are known to be dynamically important in the interstellar medium of our own Galaxy, and they are ubiquitously observed in diffuse gas in the haloes of galaxies and galaxy clusters. Yet, magnetic fields have typically been neglected in studies of the formation of galaxies, leaving their global influence on galaxy formation largely unclear. Here we extend our magnetohydrodynamics (MHD) implementation in the moving-mesh code AREPO to cosmological problems which include radiative cooling and the formation of stars. In particular, we replace our previously employed divergence cleaning approach with a Powell eight-wave scheme, which turns out to be significantly more stable, even in very dynamic environments. We verify the improved accuracy through simulations of the magneto-rotational instability in accretion discs, which reproduce the correct linear growth rate of the instability. Using this new MHD code, we simulate the formation of isolated disc galaxies similar to the Milky Way using idealized initial conditions with and without magnetic fields. We find that the magnetic field strength is quickly amplified in the initial central starburst and the differential rotation of the forming disc, eventually reaching a saturation value. At this point, the magnetic field pressure in the interstellar medium becomes comparable to the thermal pressure, and a further efficient growth of the magnetic field strength is prevented. The additional pressure component leads to a lower star formation rate at late times compared to simulations without magnetic fields, and induces changes in the spiral arm structures of the gas disc. In addition, we observe highly magnetized fountain-like outflows from the disc. These results are robust with numerical resolution and are largely independent of the initial magnetic seed field strength assumed in the initial conditions, as the amplification process is rapid and self-regulated. Our findings suggest an important influence of magnetic fields on galaxy formation and evolution, cautioning against their neglect in theoretical models of structure formation.

Pakmor, Rüdiger; Springel, Volker

2013-06-01

25

Extensive population synthesis of isolated neutron stars with field decay  

NASA Astrophysics Data System (ADS)

We perform population synthesis studies of different types of neutron stars (thermally emitting isolated neutron stars, normal radio pulsars, magnetars) taking into account the magnetic field decay and using results from the most recent advances in neutron star cooling theory. For the first time, we confront our results with observations using simultaneously the Log N--Log S distribution for nearby isolated neutron stars, the Log N--Log L distribution for magnetars, and the distribution of radio pulsars in the P--? diagram. For this purpose, we fix a baseline neutron star model (all microphysics input), and other relevant parameters to standard values (velocity distribution, mass spectrum, etc.), only allowing to vary the initial magnetic field strength. We find that our theoretical model is consistent with all sets of data if the initial magnetic field distribution function follows a log-normal law with < log(B0/[G])>~13.25 and ?log B0~0.6. The typical scenario includes about 10% of neutron stars born as magnetars, significant magnetic field decay during the first million years of a NS life (only about a factor of 2 for low field neutron stars but more than an order of magnitude for magnetars), and a mass distribution function dominated by low mass objects. This model explains satisfactorily all known populations. Evolutionary links between different subclasses may exist, although robust conclusions are not yet possible. We apply the obtained field distribution and the model of decay to study long-term evolution of neuton stars till the stage of accretion from the interstellar medium. It is shown that though the subsonic propeller stage can be relatively long, initially highly magnetized neutron stars (B0>~1013 G) reach the accretion regime within the Galactic lifetime if their kick velocities are not too large. The fact that in previous studies made >10 years ago, such objects were not considered results in a slight increase of the Accretor fraction in comparison with earlier conclusions. Most of the neutron stars similar to the Magnificent seven are expected to become accreting from the interstellar medium after few billion years of their evolution. They are the main predecestors of accreting isolated neutron stars.

Popov, S. B.; Boldin, P. A.; Miralles, J. A.; Pons, J. A.; Posselt, B.

2011-09-01

26

Incipient fault detection and isolation of sensors and field devices  

NASA Astrophysics Data System (ADS)

The purpose of this research is to develop a robust fault detection and isolation method, for detecting faults in process sensors, actuators, controllers and other field devices. The approach to the solution to this problem is summarized below. A novel approach for the validation of control system components and sensors was developed in this research. The process is composed of detecting a system anomaly, isolating the faulty component (such as sensors, actuators, and controllers), computing its deviation from expected value for a given system's normal condition, and finally reconstructing its output when applicable. A variant of the Group Method of Data Handling (GMDH) was developed in this research for generating analytical redundancy from relationships among different system components. A rational function approximation was used for the data-driven modeling scheme. This analytical redundancy is necessary for detecting system anomalies and isolating faulty components. A rule-base expert system was developed in order to isolate the faulty component. The rule-based was established from model-simulated data. A fuzzy-logic estimator was implemented to compute the magnitude of the loop component fault so that the operator or the controller might take corrective actions. This latter engine allows the system to be operated in a normal condition until the next scheduled shutdown, even if a critical component were detected as degrading. The effectiveness of the method developed in this research was demonstrated through simulation and by implementation to an experimental control loop. The test loop consisted of a level control system, flow, pressure, level and temperature measuring sensors, motor-operated valves, and a pump. Commonly observed device faults were imposed in different system components such as pressure transmitters, pumps, and motor-operated valves. This research has resulted in a framework for system component failure detection and isolation, allowing easy implementation of this method in any process control system (power plants, chemical industry, and other manufacturing industry). The technique would also aid the plant personnel in defining the minimal number of sensors to be installed in a process system, necessary for reliable component validation.

Ferreira, Paulo Brasko

27

Bacillus huizhouensis sp. nov., isolated from a paddy field soil.  

PubMed

A Gram-stain positive, facultative aerobic bacterium, designated as strain GSS03(T), was isolated from a paddy field soil. The cells were observed to be endospore forming, rod-shaped and motile with flagella. The organism was found to grow optimally at 35 °C at pH 7.0 and in the presence of 1 % NaCl. The strain was classified as a novel taxon within the genus Bacillus on the basis of phenotypic and phylogenetic analyses. The closest phylogenetic relatives were identified as Bacillus psychrosaccharolyticus DSM 6(T) (97.61 %), Bacillus muralis DSM 16288(T) (97.55 %), Bacillus asahii JCM 12112(T) (97.48 %), Bacillus simplex DSM 1321(T) (97.48 %) and "Bacillus frigoritolerans" DSM 8801(T) (97.38 %). The menaquinone was identified as MK-7, the major cellular fatty acid was identified as anteiso-C15:0 and the major cellular polar lipids as phosphatidylethanolamine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and three unknown polar lipids. The DNA G+C content was determined to be 40.2 mol%. The DNA-DNA relatedness with the closest relatives was below 48 %. Therefore, on the basis of all the results, strain GSS03(T) is considered to represent a novel species within the genus Bacillus, for which the name Bacillus huizhouensis sp. nov. is proposed. The type strain is GSS03(T) (=KCTC 33172(T) =CCTCC AB 2013237(T)). PMID:24903955

Li, Jibing; Yang, Guiqin; Wu, Min; Zhao, Yong; Zhou, Shungui

2014-08-01

28

Serological studies of infectious bronchitis vaccines against Japanese field isolates of homologous and heterologous genotypes.  

PubMed

The genetic diversity of the partial S1 gene involving the hyper variable region for infectious bronchitis (IB) vaccine strains in Japan were compared with those of IB virus isolated from the field in Japan. Field isolates have mainly been classified into three major genotypes, JP-I, JP-II and JP-III, since 2003; however, the 4/91 genotype was detected from recent field isolates in Japan. The virus neutralization (VN) activity with vaccine immunized serum was investigated to evaluate the protective effects of vaccines against Japanese field isolates. In the results of the VN test, antiserum immunized with the GN and C78 (JP-I), TM-86w and Miyazaki (JP-II) and 4/91 (793B) vaccine strains could neutralize a high rate of field isolates of homologous genotype (75% of field isolates of JP-I, 100% of that of JP-II and 100% of that of 793B, respectively). For field isolates of JP-III, even though there are no homologous genotype vaccine strain, some strains of JP-III were neutralized with immune serum from vaccine strains of the heterologous genotype. In this study, a correlation between serological property and genotype was found for JP-I, JP-II and 793B. Our results suggested that an effective vaccine could be predicted in accordance with the genotype of field isolates. PMID:19652475

Shimazaki, Yohko; Harada, Makiko; Horiuchi, Takashi; Yoshida, Keiko; Tanimura, Chieko; Nakamura, Shigeyuki; Mase, Masaji; Suzuki, Shoko

2009-07-01

29

Isolation, characterization, and sensitivity to 2,4-diacetylphloroglucinol of isolates of Phialophora spp. from Washington wheat fields.  

PubMed

Dark pigmented fungi of the Gaeumannomyces-Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 microg ml(-1). A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici. PMID:20373960

Kwak, Youn-Sig; Bakker, Peter A H M; Glandorf, Debora C M; Rice, Jennifer T; Paulitz, Timothy C; Weller, David M

2010-05-01

30

Post-Irradiation Effects in Field-Oxide Isolation Structures  

Microsoft Academic Search

We have studied experimentally the time dependence of leakage currents in six CMOS (complementary metaloxide semiconductor) processes using LOCOS (local oxidation of silicon) isolation structures. These six process lines represent six different U. S. semiconductor companies. In their radiation response, these processes range from very hard to very soft. In the softer processes, the radiation-induced leakage currents are due to

T. R. Oldham; A. J. Lelis; H. E. Boesch; J. M. Benedetto; F. B. McLean; J. M. McGarrity

1987-01-01

31

Resistance of field isolates of Eimeria species to anticoccidial drugs  

Microsoft Academic Search

A study was made of the incidence of coccidial oocysts in the litter of a broiler house used for commercial trials. The following anticoccidial drugs were under investigation: zoalene, Pancoxin, Lerbek and monensin. Mon?ensin was the only drug able to suppress the numbers of oocysts appearing in the litter. Two species of Eimeria were isolated from this site and their

H. D. Chapman

1976-01-01

32

Magnetic near-field measurement for FDI of ZVS full bridge isolated buck converter  

Microsoft Academic Search

) Abstract -- This paper takes place within the more general framework of the faults detection and isolation for multi- sources renewable energy systems by aims of residuals synthesis and analysis. The main contribution is the use of a magnetic near-field measurement to estimate the magnetizing current of the HF transformer used in the ZVS full bridge isolated buck converters.

Francois Guerin; Cecile Labarre; Dimitri Lefebvre

2011-01-01

33

7 CFR 201.76 - Minimum Land, Isolation, Field, and Seed Standards.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Minimum Land, Isolation, Field, and Seed Standards. 201.76 Section 201.76 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.76...

2009-01-01

34

7 CFR 201.76 - Minimum Land, Isolation, Field, and Seed Standards.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Minimum Land, Isolation, Field, and Seed Standards. 201.76 Section 201.76 Agriculture...DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Certified Seed § 201.76...

2010-01-01

35

Full field imaging of isolated metallic nano objects  

NASA Astrophysics Data System (ADS)

Since the detection of nanoparticles is a major issue in nano sciences, we have developed two instruments for the fast imaging of individual nano objects. The first one is based on a spatial modulation of the sample using an incoherent dark field illumination and a multiplexed lock in detection. The second instrument uses digital heterodyne holography. Both instruments make it possible to achieve a high signal-to-noise ratio and therefore to detect very low signal.

Absil, E.; Tessier, G.; Fournier, D.; Gross, M.; Atlan, M.

2009-07-01

36

Invasion Profiles of Brazilian Field Isolates of Plasmodium falciparum: Phenotypic and Genotypic Analyses  

Microsoft Academic Search

The invasion of red blood cells (RBCs) by Plasmodium falciparum is dependent on multiple molecular interactions between erythrocyte receptors and parasite ligands. Invasion studies using culture-adapted par- asite strains have indicated significant receptor heterogeneity. It is not known whether this heterogeneity reflects the parasite invasion arsenal in the field. We have studied the invasion phenotypes of 14 distinct field isolates

Cheryl-Ann Lobo; Karla de Frazao; Marilis Rodriguez; Marion Reid; Mariano Zalis; Sara Lustigman

2004-01-01

37

Experimental comparison of hemolytic and nonhemolytic Ornithobacterium rhinotracheale field isolates in vivo.  

PubMed

Ornithobacterium rhinotracheale (ORT) is a nonhemolytic, gram-negative, pleomorphic, rod-shaped bacterium that causes upper and lower respiratory tract disease in poultry. Recently, hemolytic strains of ORT have been isolated with increasing frequency from field outbreaks. A study was conducted to determine whether the hemolytic phenotype is associated with any change in virulence. Briefly, 225 turkey poults, vaccinated against hemorrhagic enteritis at 4 wk of age, were randomly divided into nine replicates housed in separate rooms: three sham treatment controls (25 poults/replicate), three challenged with a nonhemolytic (NH) field isolate (24 poults/replicate), and three challenged with a hemolytic (H) field isolate (24 poults/replicate). Nine days postvaccination, poults were inoculated intratracheally with either 0.2 ml sterile phosphate-buffered saline (PBS), 2 x 10(8) colony-forming units (CFU) of the NH isolate in 0.2 ml PBS, or 2 x 10(8) CFU of the H isolate in 0.2 ml PBS. Serum and body weights were obtained at 0, 7, 14, and 21 days postinoculation (dpi). Tissues were taken for culture and histopathology from five randomly selected poults/replicates at 7, 14, and 21 dpi. When compared with poults inoculated with the H isolate or controls, those inoculated with the NH isolate showed a highly significant depression in weight gain at 7 dpi. NH poults also had significantly higher levels of antibody against ORT at 14 and 21 dpi. Reisolations decreased over time and, by 21 dpi, only the NH phenotype could be found. Based on a Likert-type scale, poults inoculated with the NH isolate had significantly higher histopathologic lesion scores in lung tissue at 7, 14, and 21 dpi. Results suggest that nonhemolytic field isolates are more virulent then hemolytic ones. These findings are unusual because hemolytic phenotypes are often more virulent in other bacterial species. PMID:24758117

Walters, J; Evans, R; LeRoith, T; Sriranganathan, N; McElroy, A; Pierson, F W

2014-03-01

38

Pulsed-Field Gel Electrophoresis Diversity of Human and Bovine Clinical Salmonella Isolates  

PubMed Central

Abstract Pulsed-field gel electrophoresis (PFGE) characterization of 335 temporally and spatially matched clinical, bovine, and human Salmonella enterica subsp. enterica isolates revealed 167 XbaI PFGE patterns. These isolates were previously classified into 51 serotypes and 73 sequence types, as determined by multilocus sequence typing. Discriminatory power of PFGE (Simpson's index, D?=?0.991) was considerably higher than that of multilocus sequence typing (D?=?0.920) or serotyping (D?=?0.913). Although 128 PFGE types each only represented a single isolate, 8 PFGE types represented >4 isolates, including (i) three serotype Enteritidis and Heidelberg patterns that were only identified among human isolates, (ii) two PFGE patterns (each representing serotypes Bardo and Newport) that were significantly more common among bovine isolates as compared with human isolates; (iii) two PFGE types that each includes two serotypes (4,5,12:i:- and Typhimurium; Thompson and 1,7:-:1,5); and (iv) one PFGE type that includes eight Typhimurium isolates from humans and cattle. Characterization of isolates collected over multiple farm visits indicated that given specific PFGE types persisted over time on 11 farms. On an additional seven farms, isolates with a given sequence type represented multiple PFGE type, which typically only differed by <3 bands, suggesting PFGE type diversification during strain persistence. Sixteen PFGE types were isolated from 2 or more farms, including two widely distributed serotype Newport-associated PFGE types each found on 10 farms. In six instances two or three human isolates collected in the same county in the same or consecutive months represented the same subtypes, suggesting small human case clusters. PFGE-based characterization and surveillance of human and animal isolates can provide improved understanding of Salmonella diversity and epidemiology, including identification of possible host-associated and common, widely distributed PFGE types.

Soyer, Yesim; Alcaine, Samuel D.; Schoonmaker-Bopp, Dainna J.; Root, Timothy P.; Warnick, Lorin D.; McDonough, Patrick L.; Dumas, Nellie B.; Grohn, Yrjo T.

2010-01-01

39

DNA fingerprinting of isolates of Streptococcus mutans by pulsed-field gel electrophoresis.  

PubMed

Forty isolates and five standard laboratory strains, representing serotypes c, e and f of Streptococcus mutans were analyzed by pulsed-field gel electrophoresis (PFGE) after digestion of the genomic DNA with BssH II. The digestion patterns of standard laboratory strains were characteristic of serotypes c, e and f. Serotypes c and f generated diagnostic DNA fragments of approximately 145 kbp and of approximately 130-175 kbp in length, respectively. Serotype e generated a ladder of at least 14 fragments of 15-155 kbp in length. The digestion patterns of isolates were essentially similar to those of the standard laboratory strains. The patterns of almost all isolates obtained from a single individual were identical, but patterns of a few different types were also observed among isolates obtained from two individuals. Digestion with BssH II revealed differences among isolates obtained from different individuals. We used differences in banding patterns among isolates to construct a dendrogram. The dendrogram included two major clusters, one that consisted of isolates of serotypes c and f, and an other that consisted of isolates of serotype e. Our results indicate that BssH II is a useful enzyme for distinguishing among isolates of S. mutans and that digestion patterns obtained by PFGE can be used for chromosomal DNA fingerprinting. PMID:16870412

Mineyama, R; Yoshino, S; Maeda, N

2007-01-01

40

Molecular analysis of Salmonella enteritidis isolates from the Caribbean by pulsed-field gel electrophoresis.  

PubMed

Using pulsed-field gel electrophoresis (PFGE), between 1987 and 1996 we analyzed Salmonella enteritidis isolates from gastroenteritis cases in four Caribbean countries: Barbados, Saint Kitts and Nevis, Saint Lucia, and Trinidad and Tobago. We also determined the resistance of the isolates to 12 antimicrobial agents. Of the 129 isolates of S. enteritidis available for testing, DNA digested by XbaI revealed 13 distinctive PFGE patterns. The most prevalent XbaI PFGE patterns were group 1 (88 of 129 isolates, 68.2%) and group 2 (26 of 129, 20.2%). The patterns found among S. enteritidis isolates correlated with the geographical origin of the isolates. Of the 28 isolates from Barbados, 20 of them (71.4%) belonged to XbaI PFGE group 2, and of the 93 isolates from Trinidad and Tobago, 78 of them (83.9%) belonged to group 1. SpeI digestion of S. enteritidis genome was not as discriminatory as XbaI. Overall, of the 129 isolates, 67 of them (51.9%) exhibited resistance to one or more of the 12 antimicrobial agents that we tested. The prevalence of resistance was 53.8% for the S. enteritidis isolates tested from Trinidad and Tobago, 50.0% for those from Barbados, 28.6% for those from Saint Lucia, and 100.0% for one isolate from the island of Saint Kitts. Resistance was highest to triple sulfur (59 of 129 isolates, 45.7%), followed by furadantoin (10 of 129, 7.8%), ampicillin (7 of 129, 5.4%), and carbamycin (5 of 129, 3.9%). PMID:11190971

Adesiyun, A; Carson, A; McAdoo, K; Bailey, C

2000-11-01

41

Multilocus Sequence Typing Scheme versus Pulsed-Field Gel Electrophoresis for Typing Mycobacterium abscessus Isolates.  

PubMed

Outbreaks of infections by rapidly growing mycobacteria following invasive procedures, such as ophthalmological, laparoscopic, arthroscopic, plastic, and cardiac surgeries, mesotherapy, and vaccination, have been detected in Brazil since 1998. Members of the Mycobacterium chelonae-Mycobacterium abscessus group have caused most of these outbreaks. As part of an epidemiological investigation, the isolates were typed by pulsed-field gel electrophoresis (PFGE). In this project, we performed a large-scale comparison of PFGE profiles with the results of a recently developed multilocus sequence typing (MLST) scheme for M. abscessus. Ninety-three isolates were analyzed, with 40 M. abscessus subsp. abscessus isolates, 47 M. abscessus subsp. bolletii isolates, and six isolates with no assigned subspecies. Forty-five isolates were obtained during five outbreaks, and 48 were sporadic isolates that were not associated with outbreaks. For MLST, seven housekeeping genes (argH, cya, glpK, gnd, murC, pta, and purH) were sequenced, and each isolate was assigned a sequence type (ST) from the combination of obtained alleles. The PFGE patterns of DraI-digested DNA were compared with the MLST results. All isolates were analyzable by both methods. Isolates from monoclonal outbreaks showed unique STs and indistinguishable or very similar PFGE patterns. Thirty-three STs and 49 unique PFGE patterns were identified among the 93 isolates. The Simpson's index of diversity values for MLST and PFGE were 0.69 and 0.93, respectively, for M. abscessus subsp. abscessus and 0.96 and 0.97, respectively, for M. abscessus subsp. bolletii. In conclusion, the MLST scheme showed 100% typeability and grouped monoclonal outbreak isolates in agreement with PFGE, but it was less discriminative than PFGE for M. abscessus. PMID:24899019

Machado, Gabriel Esquitini; Matsumoto, Cristianne Kayoko; Chimara, Erica; Duarte, Rafael da Silva; de Freitas, Denise; Palaci, Moises; Hadad, David Jamil; Lima, Karla Valéria Batista; Lopes, Maria Luiza; Ramos, Jesus Pais; Campos, Carlos Eduardo; Caldas, Paulo César; Heym, Beate; Leão, Sylvia Cardoso

2014-08-01

42

Oligonucleotide fingerprinting detects genetic diversity among Ascochyta rabiei isolates from a single chickpea field in Tunisia  

Microsoft Academic Search

Fifty isolates of Ascochyta rabiei (Pass.) Labr. were hierarchically sampled from four well-separated locations of a single chickpea field in Beja (Tunisia), and single-spored. DNA was isolated from in-vitro-grown mycelia, digested with HinfI or RsaI, and hybridized to a set of synthetic oligonucleotides complementary to simple repetitive sequences. According to the fingerprint patterns derived from the probes (CA)8, (CAA)5, (CAT)5

Hichem Morjane; Jtirg Geistlinger; Moncef Harrabi; Kurt Weising; Giinter Kahl

1994-01-01

43

The use of cycloheximide-treated cells for isolating trachoma agents under field conditions*  

PubMed Central

Standard procedures for the isolation of Chlamydia trachomatis require pretreatment of the tissue culture cells. We evaluated the use of cycloheximide, an antimetabolite that can be added to the cells with the inoculum. Cycloheximide-treated cells provided a sensitive system for isolating trachoma agents. This system was applicable to field studies as requirements for equipment were minimal and the cells were 2 weeks old when inoculated.

Schachter, J.; Dawson, C. R.; Hoshiwara, I.; Daghfous, T.; Banks, J.

1978-01-01

44

Monoclonal antibody characterization of South African field isolates of Haemophilus paragallinarum.  

PubMed

A total of 27 different isolates of Haemophilus paragallinarum were made from chickens between June 1991 and December 1992. All of these isolates were examined by ELISA, by means of a locally produced panel of three monoclonal antibodies (denoted F1, V1 and VF3). The isolates were all of the F1 antigenic type. Three of them showed a weak reaction with the F1 monoclonal antibody, while three other isolates reacted strongly with the F1 as well as with the VF3 Mab. A selection of stored Haemophilus isolates, dating from 1984 to 1985, were also examined with the Mabs and found to be of the F1 antigenic type. Fifteen isolates were collected before 1974, i.e. before the use of Haemophilus vaccines in this country. The majority of them were of the F1 antigenic grouping. Some showed a weak reaction with the F1 Mab; others showed a strong reaction with both the F1 and VF3 Mabs; and a few showed no significant reaction with any of the Mabs used. Strains used for the production of infectious coryza vaccine were also examined with the Mabs. Strain 0083 showed a stronger reaction with the V1 Mab than with the F1 Mab, whereas strain 0222 showed no reaction with any of the Mabs. None of the SA field isolates collected since the use of vaccines exhibits the V1 antigenicity, which is the prevalent antigen of strain 0083. Most (80%) of the SA field isolates showed a stronger reaction with the F1 Mab than did strain 0083. Antigenically silent isolates similar to 0222 (Page's serotype B) were isolated before the use of vaccines, but not since. PMID:7970573

Bragg, R R; Coetzee, L; Verschoor, J A

1993-09-01

45

Serotypes of avian infectious bronchitis virus isolates from field cases in Japan.  

PubMed

Eight etiologic agents isolated from field cases in Japan were identified as isolates of infectious bronchitis virus by agar-gel diffusion, buoyant-density determination on sucrose-density centrifugation, and morphological study by electron microscope of the purified viruses. In studies of the antigenic relationships of the eight isolates and six known infectious bronchitis viruses, antigenic diversity of these viruses was recognized from the degrees of relatedness using a plaque reduction in the "constant-virus decreasing-serum" method. PMID:6186239

Doi, M; Yamakami, T; Koimaru, H; Yoshimura, M; Masu, S; Shirai, J; Kawamura, H

1982-01-01

46

Isolated short attosecond pulse generation in an orthogonally polarized multicycle chirped laser field  

SciTech Connect

We theoretically demonstrate the generation of a high-order harmonic and isolated attosecond pulse in an orthogonally polarized laser field, which is synthesized by an 800-nm chirped laser pulse and an 800-nm chirp-free laser pulse. Owing to the instantaneous frequency increasingly reducing close to the center of the driving pulse, the extreme ultraviolet supercontinuum for the chirped synthesized field is even broader than that for an orthogonal chirp-free two-color laser field. It is found that the broadband supercontinuum spectrum can be achieved for the driving pulse with ten and above optical cycles. After phase compensation an isolated attosecond pulse with a duration of {approx}16 as is produced. Furthermore, the optimization of the chirping rate parameters is investigated to achieve cutoff extension and an isolated short attosecond pulse.

Xu Junjie [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

2011-03-15

47

REVIEWS OF TOPICAL PROBLEMS: Isolated waveguide modes of high-intensity light fields  

NASA Astrophysics Data System (ADS)

Isolated waveguide modes of intense light fields are unique physical objects, which can never be observed in standard optical fibers, hollow waveguides, plasma filaments, or in the bulk of a transparent dielectric or gas. Hollow photonic-crystal fibers can for the first time produce robust isolated truly guided spatial modes of subgigawatt ultrashort light pulses, perform efficient nonlinear-optical transformations of laser fields in such states, and implement new waveguide regimes of coherent excitation and probing of molecular Raman-active modes in the gas phase.

Zheltikov, Aleksei M.

2004-12-01

48

Genetic structure of Plasmodium falciparum field isolates in eastern and north-eastern India  

PubMed Central

Background Molecular techniques have facilitated the studies on genetic diversity of Plasmodium species particularly from field isolates collected directly from patients. The msp-1 and msp-2 are highly polymorphic markers and the large allelic polymorphism has been reported in the block 2 of the msp-1 gene and the central repetitive domain (block3) of the msp-2 gene. Families differing in nucleotide sequences and in number of repetitive sequences (length variation) were used for genotyping purposes. As limited reports are available on the genetic diversity existing among Plasmodium falciparum population of India, this report evaluates the extent of genetic diversity in the field isolates of P. falciparum in eastern and north-eastern regions of India. Methods A study was designed to assess the diversity of msp-1 and msp-2 among the field isolates from India using allele specific nested PCR assays and sequence analysis. Field isolates were collected from five sites distributed in three states namely, Assam, West Bengal and Orissa. Results P. falciparum isolates of the study sites are highly diverse in respect of length as well as sequence motifs with prevalence of all the reported allelic families of msp-1 and msp-2. Prevalence of identical allelic composition as well as high level of sequence identity of alleles suggest a considerable amount of gene flow between the P. falciparum populations of different states. A comparatively higher proportion of multiclonal isolates as well as multiplicity of infection (MOI) was observed among isolates of highly malarious districts Karbi Anglong (Assam) and Sundergarh (Orissa). In all the five sites, R033 family of msp-1 was observed to be monomorphic with an allele size of 150/160 bp. The observed 80–90% sequence identity of Indian isolates with data of other regions suggests that Indian P. falciparum population is a mixture of different strains. Conclusion The present study shows that the field isolates of eastern and north-eastern regions of India are highly diverse in respect of msp-1 (block 2) and msp-2 (central repeat region, block 3). As expected Indian isolates present a picture of diversity closer to southeast Asia, Papua New Guinea and Latin American countries, regions with low to meso-endemicity of malaria in comparison to African regions of hyper- to holo-endemicity.

Joshi, Hema; Valecha, Neena; Verma, Anju; Kaul, Asha; Mallick, Prashant K; Shalini, Sneh; Prajapati, Surendra K; Sharma, Surya K; Dev, Vas; Biswas, Sukla; Nanda, Nutan; Malhotra, MS; Subbarao, Sarala K; Dash, Aditya P

2007-01-01

49

Molecular Typing by Pulsed-Field Gel Electrophoresis of Spanish Animal and Human Listeria monocytogenes Isolates  

PubMed Central

A total of 153 strains of Listeria monocytogenes isolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains of L. monocytogenes displayed 55 pulsotypes. The 84 animal, 51 human, and 18 feedstuff strains displayed 31, 29, and 7 different pulsotypes, respectively, indicating a great genetic diversity among the Spanish L. monocytogenes isolates studied. L. monocytogenes isolates from clinical samples and feedstuffs consumed by the diseased animals were analyzed in 21 flocks. In most cases, clinical strains from different animals of the same flock had identical pulsotypes, confirming the existence of a listeriosis outbreak. L. monocytogenes strains with pulsotypes identical to those of clinical strains were isolated from silage, potatoes, and maize stalks. This is the first study wherein potatoes and maize stalks are epidemiologically linked with clinical listeriosis.

Vela, A. I.; Fernandez-Garayzabal, J. F.; Vazquez, J. A.; Latre, M. V.; Blanco, M. M.; Moreno, M. A.; de la Fuente, L.; Marco, J.; Franco, C.; Cepeda, A.; Rodriguez Moure, A. A.; Suarez, G.; Dominguez, L.

2001-01-01

50

Molecular detection, epidemiology, and genetic characterization of novel European field isolates of equine infectious anemia virus.  

PubMed

The application of molecular diagnostic techniques along with nucleotide sequence determination to permit contemporary phylogenetic analysis of European field isolates of equine infectious anemia virus (EIAV) has not been widely reported. As a result, of extensive testing instigated following the 2006 outbreak of equine infectious anemia in Italy, 24 farms with a history of exposure to this disease were included in this study. New PCR-based methods were developed, which, especially in the case of DNA preparations from peripheral blood cells, showed excellent correlation with OIE-approved agar gel immunodiffusion (AGID) tests for identifying EIAV-infected animals. In contrast, the OIE-recommended oligonucleotide primers for EIAV failed to react with any of the Italian isolates. Similar results were also obtained with samples from four Romanian farms. In addition, for the first time complete characterization of gag genes from five Italian isolates and one Romanian isolate has been achieved, along with acquisition of extensive sequence information (86% of the total gag gene) from four additional EIAV isolates (one Italian and three Romanian). Furthermore, in another 23 cases we accomplished partial characterization of gag gene sequences in the region encoding the viral matrix protein. Analysis of this information suggested that most Italian isolates were geographically restricted, somewhat reminiscent of the "clades" described for human immunodeficiency virus type 1 (HIV-1). Collectively this represents the most comprehensive genetic study of European EIAV isolates conducted to date. PMID:21084503

Cappelli, Katia; Capomaccio, Stefano; Cook, Frank R; Felicetti, Michela; Marenzoni, Maria Luisa; Coppola, Giacomo; Verini-Supplizi, Andrea; Coletti, Mauro; Passamonti, Fabrizio

2011-01-01

51

Invasion Profiles of Brazilian Field Isolates of Plasmodium falciparum: Phenotypic and Genotypic Analyses†  

PubMed Central

The invasion of red blood cells (RBCs) by Plasmodium falciparum is dependent on multiple molecular interactions between erythrocyte receptors and parasite ligands. Invasion studies using culture-adapted parasite strains have indicated significant receptor heterogeneity. It is not known whether this heterogeneity reflects the parasite invasion arsenal in the field. We have studied the invasion phenotypes of 14 distinct field isolates from the Legal Amazon areas of Brazil by using erythrocyte invasion assays to investigate invasion into normal, enzyme-treated, and clinical-mutant RBCs. Analysis of these isolates revealed four distinct invasion profiles. Using En(a?) cells to get an unequivocal estimate of the use of glycophorin A (GPA) as a receptor, we found that the 175-kDa erythrocyte-binding antigen (EBA-175)/GPA pathway was used by a minority of the parasite isolates studied. Although polymorphism of region II domains at specific amino acid positions in both EBA-140 and EBA-181 was found in these field isolates, this did not correlate with invasion profiles and thus receptor selectivity. These studies have further confirmed the existence of a significant diversity of invasion pathways in nature and suggest that additional parasite ligands will have to be targeted to devise global vaccines that will work in the field.

Lobo, Cheryl-Ann; de Frazao, Karla; Rodriguez, Marilis; Reid, Marion; Zalis, Mariano; Lustigman, Sara

2004-01-01

52

Isolation and characterization of Dobrava hantavirus carried by the striped field mouse (Apodemus agrarius) in Estonia  

Microsoft Academic Search

Dobrava hantavirus (DOB) was isolated from the striped field mouse (Apodemus agrarius) trapped on Saaremaa Island, Estonia, and its genetic and antigenic characteristics were subsequently analysed. Phylogenetic analysis showed that the Estonian DOB strain, together with several wild strains carried by Apodemus agrarius, forms a well-supported lineage within the DOB clade. The topography of the trees calculated for the S,

Kirill Nemirov; Olli Vapalahti; Vera Vasilenko; Irina Golovljova; Angelina Plyusnina; Jukka Niemimaa; Juha Laakkonen; Heikki Henttonen; Antti Vaheri; Alexander Plyusnin

1999-01-01

53

In vitro sensitivity of Plasmodium falciparum field isolates to extracts from Cameroonian Annonaceae plants.  

PubMed

In a search for new plant-derived antimalarial extracts, 19 fractions were obtained from three Annonaceae species, Uvariopsis congolana (leaf, stem), Polyalthia oliveri (stem bark), and Enantia chlorantha (stem, stem bark) with yields ranging from 0.33% to 4.60%. The extracts were prepared from 500 g of each plant part, using organic solvents to afford five methanolic fractions (acetogenin rich), five water fractions, five hexane fractions, and four interface precipitates. Evaluation of the activity of fractions in vitro against field isolates of the malaria parasite Plasmodium falciparum showed that acetogenin-rich fractions and interface precipitates were the most potent, with IC(50) values ranging from 0.05 to 8.09 ?g/ml. Sensitivity of parasite isolates to plant extracts varied greatly, with over 100-fold difference from isolate to isolate in some cases. The active acetogenin-rich fractions and interface precipitates were assessed in combination with chloroquine in the same conditions, and showed additive interaction in the huge majority of cases. Synergistic interactions were found in some cases with acetogenin-rich fractions. Acute toxicity of promising fractions was evaluated through oral administration in Swiss albino mice. Tested fractions appeared to be safe, with LD(50) values higher than 2 g/kg. In summary, acetogenin-rich fractions from Annonaceae species showed high potency against P. falciparum field isolates and safety by oral administration in mice, supporting their detailed investigation for antimalarial drug discovery. PMID:21739316

Kemgne, Eugénie Aimée Madiesse; Mbacham, Wilfred Fon; Boyom, Fabrice Fekam; Zollo, Paul Henri Amvam; Tsamo, Etienne; Rosenthal, Philip J

2012-01-01

54

The impact of a magnetic field on ferromagnetic materials isolated using ultraviolet laser ablation  

NASA Astrophysics Data System (ADS)

Laser ablation technology is used to isolate magnetic material to generate a local magnetic field effect. The impact of an induced magnetic field is enhanced by using the external magnetic field and can be widely employed to collect magnetic particles and position biomolecular in the bio-examination field. In addition, the magnetic field is affected and induced by the thermal stress produced after energy is exerted on the materials. Therefore, this study presents the phase of induced magnetic field (PIMF) of ferromagnetic film (Ni—1-?m thick) isolated using a 355-nm pulsed ultraviolet laser. In the experiment, three patterns comprising the following shapes and various isolated angle were designed for testing: hexagon (type I, 120°), L shape (type II, 90°), and cross shape (type III, 90°). The magnetic force microscopy image showed that when the isolating angle decreased, the PIMF increased, the value of which at the periphery of the corner of the type I and II patterns was -3.96° and -4.09°, respectively. In addition, by increasing the ablation time and residual thermal stress remaining in the material to increase the impact of the material's properties when laser scanning speed was reduced from 1,000 to 500 mm/s, the PIMF value increased from -4.09° to -5.82°. The PIMF value of the type III pattern increased to -9.87° because the residual thermal stress was twice that of the type II pattern. In the future, the experimental results can be used as a helpful reference for controlling magnetic particles in biomedical chips.

Tsai, Hsin-Yi; Yang, Ching Ching; Yang, Chih-Chung; Hsiao, Wen-Tse; Huang, Kuo-Cheng

2014-06-01

55

Quantum path controlling in the presence of a low frequency field to generate isolated attosecond pulse  

NASA Astrophysics Data System (ADS)

In this article, an efficient method is presented to generate an isolated attosecond pulse based on synthesized laser field. The 1D time-dependent Schrödinger equation is numerically solved for a helium atom exposed in a strong laser field. Two color fields containing a chirped laser pulse and its half harmonic as control pulse are modulated by a low frequency field to construct the configuration of strong laser field. The effect of low frequency field dominates the effect of the chirp parameter and extremely affects the acceleration step of high-order harmonic generation process. The low frequency field, in the optimized conditions, eliminates the long quantum path completely and only the short quantum path contributes in the higher harmonics emission mechanism. With such scheme, an extra supercontinuum with 700 eV bandwidth can be generated which supports the creation of a 64 attosecond isolated pulse. Moreover, the classical electron dynamics and the time-frequency analysis for explaining the underlying physics of atom-pulse interaction are also presented.

Dashcasan, M.

2014-05-01

56

In vitro antimicrobial activity against reference strains and field isolates of Treponema hyodysenteriae.  

PubMed

The in vitro susceptibilities of eight isolates of Treponema hyodysenteriae from pigs naturally infected with swine dysentery between 1976 and 1983 were determined by an agar dilution technique. Carbadox, olaquindox, tiamulin, metronidazole, furazolidone, and monensin were the most active against these field isolates regardless of the year of recovery. The influence of inoculum size on the MICs against four reference strains of T. hyodysenteriae was studied. Various degrees of activities of ampicillin and lincomycin were found, depending on the inoculum size. The effect of successive in vitro subcultures on the susceptibility of a reference strain of T. hyodysenteriae was examined. The strain resistant to tylosin became susceptible to the drug. PMID:3439804

Kitai, K; Kashiwazaki, M; Adachi, Y; Kunugita, K; Arakawa, A

1987-12-01

57

A new spiroplasma isolate from the field cricket (Gryllus bimaculatus) in Taiwan.  

PubMed

We briefly described the morphology and transmission pathway of a Spiroplasma sp. isolated from the field cricket, Gryllus bimaculatus in Taiwan, followed by the phylogenetic analysis based on the 16S rRNA gene sequence. The cricket spiroplasma infected the hemolymph, gut, muscle tissues and tracheal cells; therefore we suggest that the pathogen invaded tissues and organs from the hemolymph through the tracheal system and the endoplasmic reticular system. Based on 16S rRNA gene sequences and the phylogeny, this spiroplasma was most closely related to Spiroplasma platyhelix (Identity=95%) isolated from the dragonfly Pachydiplax longipennis and belongs to the Ixodetis clade. PMID:24801581

Nai, Yu-Shin; Su, Ping-Yi; Hsu, Yu-Hsiang; Chiang, Ching-Hao; Kim, Jae Su; Chen, Yue-Wen; Wang, Chung-Hsiung

2014-07-01

58

Pulsed field gel electrophoresis analysis of Borrelia burgdorferi sensu lato isolated in Japan and taxonomic implications with Lyme disease spirochetes.  

PubMed

Genomic DNAs of Borrelia burgdorferi sensu lato isolates obtained in Japan sharing different rRNA gene ribotypes were digested with rare-cutter restriction endonucleases and the fragments obtained were separated by pulsed field gel electrophoresis (PFGE). The sizes of large restriction cleavage bands with MluI endonuclease were quite similar among isolates in each ribotype group. On the other hand, the PFGE profiles obtained with the other enzymes (NruI, Sal I or SplI) were rather divergent, and Japanese isolates were distinguishable from the United States and European isolates. The Japanese isolates classified as ribotypes group II (Borrelia garinii) and III (B. afzelii) showed different PFGE patterns from that of European isolates. The isolates grouped into ribotype IV revealed distinctively different PFGE profiles. These results indicate that the Japanese isolates may be genetically divergent and distinct from the United States and European isolates. PMID:7531811

Fukunaga, M; Takahashi, Y

1994-01-01

59

Use of Leishmania donovani Field Isolates Expressing the Luciferase Reporter Gene in In Vitro Drug Screening†  

PubMed Central

Currently available primary screens for the selection of candidate antileishmanial compounds are not ideal. These techniques are time-consuming, laborious, and difficult to scale and require macrophages, which limit their use for high-throughput screening. We have developed Leishmania donovani field isolates that constitutively express the firefly luciferase reporter gene (luc) as a part of an episomal vector. An excellent correlation between parasite number and luciferase activity was observed. luc expression was stable, even in the absence of drug selection, for 4 weeks. The transfectants were infective to macrophages, and intracellular amastigotes exhibited luciferase activity. The suitability of these recombinant field isolates for in vitro screening of antileishmanial drugs was established. The luciferase-expressing sodium stibogluconate-resistant cell lines offer a model for the screening of compounds for resistance. The system is in routine use at the Central Drug Research Institute, Lucknow, India, for high-throughput screening of newly synthesized compounds.

Ashutosh; Gupta, Suman; Ramesh; Sundar, Shyam; Goyal, Neena

2005-01-01

60

The evolution of isolated neutron stars until accretion: the role of the initial magnetic field  

NASA Astrophysics Data System (ADS)

We study the evolution of isolated neutron stars on long time-scales and calculate the distribution of these sources in the main evolutionary stages: ejector, propeller, accretor and georotator. We make comparisons among different initial magnetic field distributions taking into account the possibility of magnetic field decay, and include in our calculations the stage of subsonic propeller. It is shown that though the subsonic propeller stage can be relatively long, initially highly magnetized neutron stars (B0 >~ 1013G) reach the accretion regime within the Galactic lifetime if their kick velocities are not too large. The fact that in previous studies made >10 yr ago such objects were not considered results in a slight increase of the accretor fraction in comparison with earlier conclusions. Most of the neutron stars similar to the Magnificent Seven are expected to become accreting from the interstellar medium after a few billion years of their evolution. They are the main predecessors of accreting isolated neutron stars.

Boldin, P. A.; Popov, S. B.

2010-09-01

61

Hy-wire and fast electric field change measurements near an isolated thunderstorm, appendix C  

NASA Technical Reports Server (NTRS)

Electric field measurements near an isolated thunderstorm at 6.4 km distance are presented from both a tethered balloon experiment called Hy-wire and also from ground based fast and slow electric field change systems. Simultaneous measurements were made of the electric fields during several lightning flashes at the beginning of the storm which the data clearly indicate were cloud-to-ground flashes. In addition to providing a comparison between the Hy-wire technique for measuring electric fields and more traditional methods, these data are interesting because the lightning flashes occurred prior to changes in the dc electric field, although Hy-wire measured changes in the dc field of up to 750 V/m in the direction opposite to the fair weather field a short time later. Also, the dc electric field was observed to decay back to its preflash value after each flash. The data suggest that Hy-wire was at the field reversal distance from this storm and suggest the charge realignment was taking place in the cloud with a time constant on the order of 20 seconds.

Holzworth, R. H.; Levine, D. M.

1983-01-01

62

Outbreak-Related Porcine Epidemic Diarrhea Virus Strains Similar to US Strains, South Korea, 2013  

PubMed Central

In late 2013, outbreaks of porcine epidemic diarrhea virus (PEDV) infection recurred in South Korea. Genetic and phylogenetic analyses showed that isolates from the outbreaks were most closely related to emergent US strains of PEDV. These US strain–like PEDV variants are prevalent in South Korea and responsible for recent outbreaks in the country.

Lee, Sunhee

2014-01-01

63

Characterization and genetic analysis of field isolates of Botryotinia fuckeliana (Botrytis cinerea) resistant to dichlofluanid  

Microsoft Academic Search

Field isolates ofBotryotinia fuckeliana were collected from naturally infected plants. Their responses to the multisite fungicide dichlofluanid in mycelium growth test fell into three phenotypic classes, characterized by the following EC50 (and MIC) values inµg ml-1: sensitivity, 1–3 (6–10); low resistance, 3–10 (> 100); high resistance, 10–30 (> 100). The corresponding values obtained for these classes in a spore germination

Stefania Pollastro; Franco Faretra; Vincenzo Di Canio; Antonietta De Guido

1996-01-01

64

Isolated Electrostatic Structures Observed Throughout the Cluster Orbit: Relationship to Magnetic Field Strength  

Microsoft Academic Search

Isolated electrostatic structures are observed throughout much of the 4 Re by\\u000a19.6 Re Cluster orbit. These structures are observed in the Wideband plasma\\u000awave instrument's waveform data as bipolar and tripolar pulses. These\\u000astructures are observed at all of the boundary layers, in the solar wind and\\u000amagnetosheath, and along auroral field lines at 4.5-6.5 Re. Using the Wideband

J. S. Pickett; L.-J. Chen; S. W. Kahler; O. Santolik; D. A. Gurnett; B. T. Tsurutani; A. Balogh

2004-01-01

65

Isolation of Tricholoma matsutake and T. bakamatsutake cultures from field-collected ectomycorrhizas  

Microsoft Academic Search

Tricholoma matsutake was isolated into pure cultures from field samples of ectomycorrhizas onPinus densiflora. The mycorrhizal tips were collected at different times of the year from a colony ofT. matsutake in aP. densiflora stand. The mycorrhizal tips were continuously washed with sterilized distilled water and diluted Tween 80 solution, surface-sterilized\\u000a with calcium hypochlorite solution, and inoculated on several kinds of

Akiyoshi Yamada; Takeo Ogura; Yosuke Degawa; Masatake Ohmasa

2001-01-01

66

Genetic structure of Plasmodium falciparum field isolates in eastern and north-eastern India  

Microsoft Academic Search

BACKGROUND: Molecular techniques have facilitated the studies on genetic diversity of Plasmodium species particularly from field isolates collected directly from patients. The msp-1 and msp-2 are highly polymorphic markers and the large allelic polymorphism has been reported in the block 2 of the msp-1 gene and the central repetitive domain (block3) of the msp-2 gene. Families differing in nucleotide sequences

Hema Joshi; Neena Valecha; Anju Verma; Asha Kaul; Prashant K Mallick; Sneh Shalini; Surendra K Prajapati; Surya K Sharma; Vas Dev; Sukla Biswas; Nutan Nanda; Malhotra; Sarala K Subbarao; Aditya P Dash

2007-01-01

67

Prevalence of resistance associated polymorphisms in Plasmodium falciparum field isolates from southern Pakistan  

Microsoft Academic Search

BACKGROUND: Scarce data are available on Plasmodium falciparum anti-malarial drug resistance in Pakistan. The aim of this study was, therefore, to determine the prevalence of P. falciparum resistance associated polymorphisms in field isolates from southern Pakistan. METHODS: Blood samples from 244 patients with blood-slide confirmed P. falciparum mono-infections were collected between 2005-2007. Single nucleotide polymorphisms in the P. falciparum chloroquine

Najia Karim Ghanchi; Johan Ursing; Mohammad A Beg; Maria I Veiga; Sana Jafri; Andreas Mårtensson

2011-01-01

68

Pulsed field gel electrophoresis of related Escherichia coli O157 isolates associated with beef cattle and comparison with unrelated isolates from animals, meats and humans.  

PubMed

The pulsed field gel electrophoresis (PFGE) diversity of 51 related Escherichia coli O157 isolates, associated with beef cattle from a single-farm-to-single abattoir (SF-SA) chain of events was determined. The 51 related E. coli O157 isolates from hides, faeces or carcasses of SF-SA cattle produced 11 different PFGE profiles. Also, the PFGE diversity of 6 isolates, associated with a second cattle abattoir, was determined; only two PFGE profiles were found. On the other hand, the PFGE diversity of 136 unrelated E. coli O157 isolates (from healthy meat animals, retail meats and cases of human disease) was also determined. The 136 unrelated E. coli O157 isolates produced 78 different PFGE profiles, most of which (approximately 70%) comprised only one isolate. Overall, the results showed: (a) related E. coli O157 isolates (from both SF-SA events, and the second abattoir) had a markedly narrower clonal profile than the 136 unrelated E. coli O157 isolates; (b) the isolation of identical PFGE types from hide, lairage environment, and carcasses confirms the significance of cross-contamination (both pre-slaughter and during skinning) taking place at abattoirs; and (c) PFGE typing of isolates offers a good tool for tracking sources/routes of such cross-contamination. Such cross-contamination may lead to originally E. coli O157-free animals (and resultant carcasses) becoming contaminated during farm-slaughter-dressing chain of events, so development of efficient control strategies is required. PMID:15109793

Avery, S M; Liebana, E; Hutchison, M L; Buncic, S

2004-04-15

69

Characterization of Meq proteins from field isolates of Marek's disease virus in Japan.  

PubMed

Serotype 1 strains of Marek's disease virus (MDV-1) cause malignant lymphomas in chickens (Marek's disease; MD). Although MD has been controlled by vaccination, field isolates of MDV-1 have tended to increase in virulence and cause MD even in vaccinated chickens. Meq, a putative MDV-1 oncoprotein, resembles the Jun/Fos family of basic leucine zipper (bZIP) transcription factors and can regulate the expression of viral and cellular genes as a homodimer or as a heterodimer with a variety of bZIP family proteins. Sequencing analysis of some of the viral genes of various MDV-1 strains revealed a distinct diversity of and point mutations in Meq, which may contribute to changes in the transcriptional activities of Meq and, consequently, to increases in MDV-1 oncogenicity. However, few reports have characterized MDV-1 strains isolated in Japan. In this study, we established the amino acid sequences of MDV-1 field isolates from Japan in order to determine whether they display a distinct diversity of and point mutations in Meq. In addition, we analyzed the transactivation activities of the Meq proteins in order to evaluate whether the observed mutations affect their functions. Japanese MDV-1 isolates displayed the distinct mutations in basic region 2 (BR2) and proline-rich repeats (PRRs) of the Meq proteins as well as some unique mutations. Reporter assays revealed that the amino acid substitutions in BR2 and the PRRs affected the Meq transactivation activity. These results suggest that the distinct mutations are also present in the Meq proteins of MDV-1 isolates from Japan and affect their transactivation activities. PMID:23352889

Murata, Shiro; Hashiguchi, Tomoyuki; Hayashi, Yuko; Yamamoto, Yuki; Matsuyama-Kato, Ayumi; Takasaki, Sarah; Isezaki, Masayoshi; Onuma, Misao; Konnai, Satoru; Ohashi, Kazuhiko

2013-06-01

70

Detection and Isolation Techniques for Methanogens from Microbial Mats (in the El Tatio Geyser Field, Chile)  

NASA Astrophysics Data System (ADS)

Isolating methanogenic archea from an extreme environment such as El Tatio (high altitude, arid climate) gives insight to the methanogenic taxas able to adapt and grow under extreme conditions. The hydrothermal waters at El Tatio geyser field demonstrate extreme geochemical conditions, with discharge water from springs and geysers at local boiling temperature (85° C) with high levels of arsenic and low DIC levels. Despite these challenges, many of El Tatio’s hundred plus hydrothermal features host extensive microbial mat communities, many showing evidence of methanogenesis. When trying to isolate methanogens unique to this area, various approaches and techniques were used. To detect the presence of methanogens in samples taken from the field, dissolved methane concentrations were determined via gas chromatography (GC) analysis. Samples were then selected for culturing and most probable number (MPN) enumeration, where growth was assessed using both methane production and observations of fluorescence under UV light. PCR was used to see if the archeal DNA was apparent directly from the field, and shotgun cloning was done to determine phylogenetic affiliation. Several culturing techniques were carried out in an attempt to isolate methanogens from samples that showed evidence of methanogenesis. The slant culturing method was used because of the increased surface area for colonization combined with the relative ease of keeping anaerobic. After a few weeks, when colonies were apparent, some were aseptically selected and inoculated to observe growth in a liquid media containing ampicillin to inhibit bacterial growth. Culturing techniques proved successful after inoculation, showing a slow growth of methanogens via GC and autofluorescence. Further PCR tests and subsequent sequencing were done to confirm and identify isolates.

Pearson, E. Z.; Franks, M. A.; Bennett, P.

2010-12-01

71

Virulence of South African isolates of Haemophilus paragallinarum. Part 2: naturally occurring NAD-independent field isolates.  

PubMed

Naturally occurring NAD-independent variants of Haemophilus paragallinarum, which have been isolates from poultry showing clinical signs of infectious coryza, were used to determine their virulence using a newly developed challenge model for infectious coryza. It was established that the NAD-independent isolates belonging to a particular serogroup, were less virulent when compared to the virulence of the NAD-dependent isolates from the same serogroup. It was shown that the virulence of the NAD-independent isolates belonging to serogroup C and serogroup A were very similar to each other. This differs to the results obtained with NAD-dependent isolates reported on previously, in which the serogroup C isolates were found to be more virulent then the serogroup A isolates. PMID:12234004

Bragg, R R

2002-06-01

72

Identification and Characterization of Pathogenic Yersinia enterocolitica Isolates by PCR and Pulsed-Field Gel Electrophoresis  

PubMed Central

Approximately 550 to 600 yersiniosis patients are reported annually in Sweden. Although pigs are thought to be the main reservoir of food-borne pathogenic Yersinia enterocolitica, the role of pork meat as a vehicle for transmission to humans is still unclear. Pork meat collected from refrigerators and local shops frequented by yersiniosis patients (n = 48) were examined for the presence of pathogenic Yersinia spp. A combined culture and PCR method was used for detection, and a multiplex PCR was developed and evaluated as a tool for efficient identification of pathogenic food and patient isolates. The results obtained with the multiplex PCR were compared to phenotypic test results and confirmed by pulsed-field gel electrophoresis (PFGE). In all, 118 pork products (91 raw and 27 ready-to-eat) were collected. Pathogenic Yersinia spp. were detected by PCR in 10% (9 of 91) of the raw pork samples (loin of pork, fillet of pork, pork chop, ham, and minced meat) but in none of the ready-to-eat products. Isolates of Y. enterocolitica bioserotype 4/O:3 were recovered from six of the PCR-positive raw pork samples; all harbored the virulence plasmid. All isolates were recovered from food collected in shops and, thus, none were from the patients' home. When subjected to PFGE, the six isolates displayed four different NotI profiles. The same four NotI profiles were also present among isolates recovered from the yersiniosis patients. The application of a multiplex PCR was shown to be an efficient tool for identification of pathogenic Y. enterocolitica isolates in naturally contaminated raw pork.

Thisted Lambertz, S.; Danielsson-Tham, M.-L.

2005-01-01

73

The Limitations of Pulsed-Field Gel Electrophoresis for Analysis of Yersinia enterocolitica Isolates.  

PubMed

This study describes the analysis of 432 isolates of Yersinia enterocolitica by pulsed-field gel electrophoresis (PFGE). PFGE had a high level of discrimination with biotype 1A isolates (Simpson's Diversity Index 0.997), but with the clinically important biotypes 2, 3 and 4, the discriminatory ability of PFGE was so low as to severely limit its usefulness (DI <0.6). For biotypes 2, 3 and 4, 79% or more of isolates of each biotype were of just three different PFGE profiles. Because of this, four known outbreaks of yersiniosis would not have been identified by PFGE analysis. However, a previously unrecognized potential outbreak of yersiniosis caused by biotype 4 isolates was identified on the basis of a rare PFGE genotype with spatial and temporal clustering. We conclude that PFGE has a very limited application to the genotyping of Y. enterocolitica biotypes 2, 3 and 4, and inferences based on finding indistinguishable PFGE profiles among cases or between cases and sources need to be substantiated using alternative typing tools, or strong epidemiological evidence. PMID:24237638

Gilpin, B J; Robson, B; Lin, S; Hudson, J A; Weaver, L; Dufour, M; Strydom, H

2014-09-01

74

Persistent hog cholera infection detected during virulence typing of 135 field isolates.  

PubMed

During the hog cholera (HC) eradication program in the United States, 135 field isolates were characterized by inoculation into specific-pathogen-free pigs. This gave origin to the classification of 61 (45%) as high virulent, 37 (27%) as low virulent, 29 (22%) as avirulent or immunizing, and 8 (6%) as capable of causing persistent infection. The persistent infections caused by the eight isolates were of long durtion, lasting in one instance to 152 days. The persistently infected pigs remained relatively free of clinical signs of HC but had high concentrations of HC virus (HCV) in their blood. When 6 of these pigs were given a second inoculation (with the virulent Ames strain of HCV), 2 died while the health status of 4 remained unchanged. PMID:6449165

Carbrey, E A; Stewart, W C; Kresse, J I; Snyder, M L

1980-06-01

75

Sequence conservation in field and experimental isolates of Borna disease virus.  

PubMed Central

Coding and noncoding sequences were analyzed from field and experimental isolates of Borna disease virus. For a 24-kDa protein, maximum divergence was 1.5% at the predicted amino acid level and 3.1% at the nucleotide level. For a 40-kDa protein, maximum divergence was 1.1% at the predicted amino acid level and 4.1% at the nucleotide level. The highest variability in sequence (10%) was found in a 40-nucleotide stretch of genomic RNA between coding sequences for the 40- and 24-kDa proteins. The degree of sequence conservation in these isolates, passaged in various host species in vivo and in vitro over a period of 64 years, is unusual for negative-strand RNA viruses.

Schneider, P A; Briese, T; Zimmermann, W; Ludwig, H; Lipkin, W I

1994-01-01

76

First clinical isolates of Cronobacter spp. (Enterobacter sakazakii) in Argentina: characterization and subtyping by pulsed-field gel electrophoresis.  

PubMed

Cronobacter species are opportunistic pathogens associated with severe infections in neonates and immunocompromised infants. From January 2009 through September 2010, two cases of neonatal infections associated with Cronobacter malonaticus and one case associated with Cronobacter sakazakii, two of them fatal, were reported in the same hospital. These are the first clinical isolates of Cronobacter spp. in Argentina. The objective of this work was to characterize and subtype clinical isolates of Cronobacter spp. in neonate patients, as well as to establish the genetic relationship between these isolates and the foodborne isolates previously identified in the country. Pulsed-field gel electrophoresis analysis showed a genetic relationship between the C. malonaticus isolates from two patients. Different results were found when the pulsed-field gel electrophoresis patterns of clinical isolates were compared with those deposited in the National Database of Cronobacter spp. PMID:24165138

Asato, Valeria C; Vilches, Viviana E; Pineda, María G; Casanueva, Enrique; Cane, Alejandro; Moroni, Mirian P; Brengi, Silvina P; Pichel, Mariana G

2013-01-01

77

Geobacter luticola sp. nov., an Fe(III)-reducing bacterium isolated from lotus field mud.  

PubMed

A novel species of Fe(III)-reducing bacterium, designated strain OSK6(T), belonging to the genus Geobacter, was isolated from lotus field mud in Japan. Strain OSK6(T) was isolated using a solid medium containing acetate, Fe(III)-nitrilotriacetate (NTA) and gellan gum. The isolate is a strictly anaerobic, gram-negative, motile, straight rod-shaped bacterium, 0.6-1.9 µm long and 0.2-0.4 µm wide. The growth of the isolate occurred at 20-40 °C with optima of 30-37 °C and pH 6.5-7.5 in the presence of up to 0.5 g NaCl l(-1). The G+C content of the genomic DNA was determined by HPLC to be 59.7 mol%. The major respiratory quinone was MK-8. The major fatty acids were 16?:?1?7c and 16?:?0. Strain OSK6(T) was able to grow with Fe(III)-NTA, ferric citrate, amorphous iron (III) hydroxide and nitrate, but not with fumarate, malate or sulfate as electron acceptors. Among examined substrates grown with Fe(III)-NTA, the isolate grew on acetate, lactate, pyruvate and succinate. Analysis of the near full-length 16S rRNA gene sequence revealed that strain OSK6(T) is closely related to Geobacter daltonii and Geobacter toluenoxydans with 95.6?% similarity to the type strains of these species. On the basis of phylogenetic analysis and physiological tests, strain OSK6(T) is described as a representative of a novel species, Geobacter luticola sp. nov.; the type strain is OSK6(T) (?=?DSM 24905(T)?=?JCM 17780(T)). PMID:22493170

Viulu, Samson; Nakamura, Kohei; Okada, Yurina; Saitou, Sakiko; Takamizawa, Kazuhiro

2013-02-01

78

Molecular characterization and detection of overexpressed C-14 alpha-demethylase-based DMI resistance in Cercospora beticola field isolates  

Microsoft Academic Search

Cercospora beticola strains were isolated from sugar beet fields in N. Greece heavily sprayed with triazoles. Two resistant phenotypes with resistance factors ranging from 18 to 25 and 65 to 115 were identified. Epoxiconazole-resistant isolates were less sensitive to the triazole flutriafol but not to the benzimidazole benomyl and the carboxamide boscalid. No fitness penalties were associated with resistance mutations

D. Nikou; A. Malandrakis; M. Konstantakaki; J. Vontas; A. Markoglou; B. Ziogas

2009-01-01

79

Monoclonal antibodies of African swine fever virus: antigenic differences among field virus isolates and viruses passaged in cell culture.  

PubMed

An analysis of the binding properties of a collection of monoclonal antibodies to African swine fever virus particles showed that virus field isolates passaged in porcine macrophages changed antigenically more than a strain of a cell-adapted virus passaged in Vero cells. From seven clones isolated from the spleen of a field-infected pig, we found four clones that had the same antigenic properties, one clone that had large changes in proteins p150 and p27 and small changes in proteins p37 and p14, and two clones that had minor changes in proteins p150 and p27, respectively. An analysis of the binding properties of the monoclonal antibodies to 23 field isolates from Africa, Europe, and America showed that the African isolates differed among themselves more than the European and the American isolates; in this study we found changes in 8 of the 10 virus proteins tested. The most variable proteins in the African isolates were p150, p27, p14, and p12. In contrast to the African isolates, protein p12 from the non-African viruses did not change. The clustering of the field virus isolates in six antigenic homology groups indicated the existence of a complex variety of African swine fever virus serotypes. PMID:2422393

García-Barreno, B; Sanz, A; Nogal, M L; Viñuela, E; Enjuanes, L

1986-05-01

80

Monoclonal antibodies of African swine fever virus: antigenic differences among field virus isolates and viruses passaged in cell culture.  

PubMed Central

An analysis of the binding properties of a collection of monoclonal antibodies to African swine fever virus particles showed that virus field isolates passaged in porcine macrophages changed antigenically more than a strain of a cell-adapted virus passaged in Vero cells. From seven clones isolated from the spleen of a field-infected pig, we found four clones that had the same antigenic properties, one clone that had large changes in proteins p150 and p27 and small changes in proteins p37 and p14, and two clones that had minor changes in proteins p150 and p27, respectively. An analysis of the binding properties of the monoclonal antibodies to 23 field isolates from Africa, Europe, and America showed that the African isolates differed among themselves more than the European and the American isolates; in this study we found changes in 8 of the 10 virus proteins tested. The most variable proteins in the African isolates were p150, p27, p14, and p12. In contrast to the African isolates, protein p12 from the non-African viruses did not change. The clustering of the field virus isolates in six antigenic homology groups indicated the existence of a complex variety of African swine fever virus serotypes.

Garcia-Barreno, B; Sanz, A; Nogal, M L; Vinuela, E; Enjuanes, L

1986-01-01

81

Breakdown characteristics of an isolated conducting object in a uniform electric field  

NASA Technical Reports Server (NTRS)

A laboratory experiment was conducted to determine the physical processes involved in the electrical breakdown of a particular spark gap arrangement. The gap consists of an isolated conducting ellipsoid located midway between two large flat electrodes. Gradual increase of the applied electric field, E, in the gap produces corona on the ellipsoid tips followed by flashover in a leader-arc sequence. The leader phase consists of the abrupt formation of ionized channels which partially bridge the gap and then decay prior to the arc. Measurements of dE/dt and of current were made, and photographs were taken with an image converter. Experimental parameters are listed.

Grothaus, M. G.; Trost, T. F.

1986-01-01

82

Crystal field theory analysis of rovibrational spectra of carbon monoxide monomers isolated in solid parahydrogen.  

PubMed

We report the first rotationally resolved and completely assigned rovibrational spectrum for a nonhydride molecule rotating in the solid phase: carbon monoxide (CO) monomers isolated in cryogenic solid parahydrogen (p-H(2)). We employ a modified crystal field theory model, in which the CO molecular spectroscopic constants are taken as adjustable parameters, to make good spectroscopic assignments for all the observed features. We discuss the limitations of this approach and highlight the need for improved theoretical models of molecular rotation dynamics in quantum solids. PMID:19566167

Fajardo, Mario E; Lindsay, C Michael; Momose, Takamasa

2009-06-28

83

[Wind tunnel experiment on canopy structural parameters of isolated tree and wind velocity field characters nearby].  

PubMed

The canopy structural parameters(porosity beta and permeability alpha) of isolated tree, and the wind velocity field character nearby were analyzed by wind tunnel experiment. The results show that alpha and beta fitted the function of alpha = beta 0.6, and the wind velocity nearby decreased in ellipsoid contour. The contour increased with increasing tree height and canopy width, and decreased with increasing permeability (or porosity). The isotach became the shape of ellipses or elliptic segments in horizontal and vertical plans. PMID:11767595

Guan, D; Zhu, T

2000-04-01

84

Field isolation for GaN MOSFETs on AlGaN/GaN heterostructure with boron ion implantation  

NASA Astrophysics Data System (ADS)

We report the investigation of boron ion implantation as a device field isolation process for GaN metal-oxide-semiconductor field-effect transistors (MOSFETs) on AlGaN/GaN heterostructure. In the mesa isolation region of a bar-type MOSFET, a parasitic MOS-channel existed and widened the designed channel width, which would result in an overestimated mobility compared with a ring-type MOSFET. After boron ions implantation in the isolation region, the overestimation of field-effect mobility of bar-type MOSFETs was eliminated. The sub-threshold characteristics and on-state drain current of the bar-type MOSFETs coincide with the ring-type devices. Long-channel ring-type MOSFETs, with and without ion implantation, were fabricated on the recess region to evaluate the sub-threshold characteristics. The MOSFETs with boron ions implanted into the recess region showed a low drain current up to the gate bias of 10V. The result indicated that boron ion implantation prevented the formation of parasitic MOS-channel in the isolation region and achieved field isolation. The current–voltage characteristics of MOSFETs with the normal recess condition demonstrated no degradation of device performance after boron ions implanted into the isolation region. Boron ion implantation by further optimization can be a field isolation method for GaN MOSFETs.

Jiang, Y.; Wang, Q. P.; Tamai, K.; Li, L. A.; Shinkai, S.; Miyashita, T.; Motoyama, S.-I.; Wang, D. J.; Ao, J.-P.; Ohno, Y.

2014-05-01

85

Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles  

PubMed Central

Background Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD) profiles and whole cell protein (WCP) lysate profiles as methods for distinguishing H. parasuis reference strains and field isolates. Results The DNA and WCP lysate profiles of 15 reference strains and 31 field isolates of H. parasuis were analyzed using the Dice and neighbor joining algorithms. The results revealed unique and reproducible DNA and protein profiles among the reference strains and field isolates studied. Simpson’s index of diversity showed significant discrimination between isolates when three 10mer primers were combined for the RAPD method and also when both the RAPD and WCP lysate typing methods were combined. Conclusions The RAPD profiles seen among the reference strains and field isolates did not appear to change over time which may reflect a lack of DNA mutations in the genes of the samples. The recent field isolates had different WCP lysate profiles than the reference strains, possibly because the number of passages of the type strains may affect their protein expression.

2012-01-01

86

Coherent control of broadband isolated attosecond pulses in a chirped two-color laser field  

SciTech Connect

A theoretical investigation is presented that uses a strong two-color laser field composed of a linearly chirped fundamental (900 nm) and its subharmonic (1800-nm) laser pulses to control coherently the broadband isolated attosecond pulses in high-order harmonic generations. After the subharmonic field is added, the intrinsic chirp of harmonic emission can be reduced significantly, and consequently, the temporal synchronization of harmonic emission with different photon energies at the level of the single-atom response can be realized. In addition, the scheme is robust against the carrier envelope phase variation to produce a twin pulse of stable sub-100-as duration, and the relative intensity of the twin pulses can be changed just by adjusting the relative time delay of the two driving pulses, which is of benefit in general pump-probe experiments.

Zou Pu; Zeng Zhinan; Zheng Yinghui; Lu Yingying; Liu Peng; Li Ruxin; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

2010-03-15

87

Genotypic diversity in Babesia bovis field isolates and vaccine strains from South Africa.  

PubMed

Genotypic diversity in Babesia bovis (cause of Asiatic redwater in cattle) vaccine strains and field isolates from South Africa were investigated using the Bv80 gene as well as microsatellites. The S11 vaccine strain possessed both A and B alleles of the Bv80 gene, as well as genotypic diversity within each allele type as defined by repeat variation resulting in different amplicon sizes. Rapid serial passage of vaccine strain from passage S10 to S24 resulted in loss of genotypic diversity that yielded a single allele A genotype with an amplicon size of 558 bp. This suggested that clonal selection occurred during rapid passaging. Extensive genotypic diversity exists in 44 field isolates characterized with both Bv80 A and B alleles, but can be readily distinguished from the S24 vaccine strain using either the Bv80 allele specific PCR assays or using multi-locus micro-satellite typing. This indicated that no recent documented clinical cases of Asiatic redwater were caused by the reversion to virulence of the current vaccine strain. PMID:24231390

Combrink, M P; Troskie, P C; Pienaar, R; Latif, A A; Mans, B J

2014-01-31

88

Isolation and Characterization of Strains CVO and FWKO B, Two Novel Nitrate-Reducing, Sulfide-Oxidizing Bacteria Isolated from Oil Field Brine  

Microsoft Academic Search

Bacterial strains CVO and FWKO B were isolated from produced brine at the Coleville oil field in Saskatchewan, Canada. Both strains are obligate chemolithotrophs, with hydrogen, formate, and sulfide serving as the only known energy sources for FWKO B, whereas sulfide and elemental sulfur are the only known electron donors for CVO. Neither strain uses thiosulfate as an energy source.

DIANE GEVERTZ; ANITA J. TELANG; GERRIT VOORDOUW; GARY E. JENNEMAN

2000-01-01

89

Comparison of visually evoked local field potentials in isolated turtle brain: patterned versus blank stimulation.  

PubMed

Isolated turtle brain/eye preparation has recently been used as a bloodless animal model for detecting the magnetic resonance imaging (MRI) signal changes produced by visually evoked neuronal currents. The present work aims to determine whether checkerboard-patterned or full field flash (blank) stimulation should be used in order to achieve stronger neuronal responses in turtle brain/eye preparation. The knowledge gained in this study is essential for optimizing the visual stimulation methods in functional neuroimaging studies using turtle brain/eye preparation. In this study, visually evoked local field potentials (LFPs) were measured and compared in turtle visual cortex and optic tectum elicited by checkerboard and full field flash stimuli with three different inter-stimulus intervals (ISIs=5, 10, and 16s). It was found that the behavior of neuronal adaptation in the cortical and tectal LFP signals for checkerboard stimulation was comparable to flash stimulation. In addition, there was no significant difference in the LFP peak amplitudes (ISI=16s) between these two stimuli. These results indicate that the intensity of neuronal responses to checkerboard is comparable to flash stimulation. These two stimulation methods should be equivalent in functional neuroimaging studies using turtle brain/eye preparation. PMID:20034520

Luo, Qingfei; Lu, Huo; Lu, Hanbing; Yang, Yihong; Gao, Jia-Hong

2010-03-15

90

Isolation and identification of pathogenic microorganisms at wastewater-irrigated fields: ratios in air and wastewater  

SciTech Connect

Samples of air and corresponding wastewater samples were taken at wastewater spray-irrigated fields. The concentrations of salmonellae and enteroviruses present in these samples were determined and compared with those of coliforms, and the ratios between them were calculated. The most common Salmonella serotype in the air was Salmonella ohio, whereas in the wastewater, Salmonella anatum was the most common. Enteroviruses isolated and identified were poliovirus, echovirus, and coxsackievirus type B. From the ratios of salmonellas to coliforms and enteroviruses to coliforms in the air, as compared to these ratios in the wastewater, it was concluded that the suitability of coliforms as an indication of airborne contamination caused by spray irrigation is questionable.

Teltsch, B.; Kedmi, S.; Bonnet, L.; Borenzstajn-Rotem, Y.; Katzenelson, E.

1980-06-01

91

Isolation and Characterization of a Novel Facultative Anaerobic Filamentous Fungus from Japanese Rice Field Soil  

PubMed Central

A novel filamentous fungus strain designated RB-1 was isolated into pure culture from Japanese rice field soil through an anaerobic role tube technique. The strain is a mitosporic fungus that grows in both aerobic and strict anaerobic conditions using various mono-, di-, tri-, and polysaccharides with acetate and ethanol productions. The amount of acetate produced was higher than that of ethanol in both aerobic and anaerobic cultures. The characteristic verrucose or punctuate conidia of RB-1 closely resembled those of some strains of the genus Thermomyces, a thermophilic or mesophilic anamorphic ascomycete. However, based on phylogenetic analysis with the small subunit (SSU) and large subunit (LSU) rDNA sequences, RB-1 was characterized as a member of the class Lecanoromycetes of the phylum Ascomycota. Currently, RB-1 is designated as an anamorphic ascomycete and is phylogenetically considered an incertae sedis within the class Lecanoromycetes.

Tonouchi, Akio

2009-01-01

92

Molecular monitoring of antimalarial drug resistance among Plasmodium falciparum field isolates from Odisha, India.  

PubMed

In the absence of definite marker for artemisinin (ART) resistance, molecular monitoring of its partner drug sulfadoxine pyrimethamine (SP) in artemisinin based combination therapy (ACTs) together with chloroquine (CQ) for which ART is negatively correlated, may predict the effectiveness of ACT. We analyzed 201 Plasmodium falciparum field isolates for drug resistance markers for CQ (pfcrt and pfmdr1), pyrimethamine (pfdhfr) and sulfadoxine (pfdhps). Our study reveals high prevalence and non-random association of resistant mutants (K76T and N86Y) of CQ markers (pfcrt and pfmdr1). The predominance of highly resistant pfdhfr genotypes for SP with intragenic and intergenic pair-wise linkage disequilibrium between single nucleotide polymorphisms of resistant mutants of pfdhfr (C59R and S108N) and pfdhps (S436A, A437G, K540E) warn on further inclusion of SP in ACT. These findings suggest the replacement of SP in ACT with alternative partner drug for better efficacy. PMID:23357175

Das Sutar, Sasmita Kumari; Dhangadamajhi, Gunanidhi; Kar, Shantanu Kumar; Ranjit, Manoranjan

2013-04-01

93

A Phase-Field Model for the Diffusive Melting of Isolated Dendritic Fragments  

NASA Astrophysics Data System (ADS)

A thermal phase-field model constructed in the "thin-interface" limit and incorporating a number of advanced numerical techniques such as adaptive mesh refinement, implicit time stepping, and a multigrid solver has been used to study the isolated diffusive melting of dendritic fragments. The results of the simulations are found to be fully consistent with the experimental observation of such melting in microgravity during the Isothermal Dendrite Growth Experiment. It is found that the rate at which the ratio of semi-major to semi-minor axes changes is a function of the melt Stefan number, which may help explain why both melting at (approximately) constant ratio and melting at slowly increasing ratio have been observed.

Mullis, Andrew M.

2014-06-01

94

De novo assembly of a field isolate genome reveals novel Plasmodium vivax erythrocyte invasion genes.  

PubMed

Recent sequencing of Plasmodium vivax field isolates and monkey-adapted strains enabled characterization of SNPs throughout the genome. These analyses relied on mapping short reads onto the P. vivax reference genome that was generated using DNA from the monkey-adapted strain Salvador I. Any genomic locus deleted in this strain would be lacking in the reference genome sequence and missed in previous analyses. Here, we report de novo assembly of a P. vivax field isolate genome. Out of 2,857 assembled contigs, we identify 362 contigs, each containing more than 5 kb of contiguous DNA sequences absent from the reference genome sequence. These novel P. vivax DNA sequences account for 3.8 million nucleotides and contain 792 predicted genes. Most of these contigs contain members of multigene families and likely originate from telomeric regions. Interestingly, we identify two contigs containing predicted protein coding genes similar to known Plasmodium red blood cell invasion proteins. One gene encodes the reticulocyte-binding protein gene orthologous to P. cynomolgi RBP2e and P. knowlesi NBPXb. The second gene harbors all the hallmarks of a Plasmodium erythrocyte-binding protein, including conserved Duffy-binding like and C-terminus cysteine-rich domains. Phylogenetic analysis shows that this novel gene clusters separately from all known Plasmodium Duffy-binding protein genes. Additional analyses showing that this gene is present in most P. vivax genomes and transcribed in blood-stage parasites suggest that P. vivax red blood cell invasion mechanisms may be more complex than currently understood. The strategy employed here complements previous genomic analyses and takes full advantage of next-generation sequencing data to provide a comprehensive characterization of genetic variations in this important malaria parasite. Further analyses of the novel protein coding genes discovered through de novo assembly have the potential to identify genes that influence key aspects of P. vivax biology, including alternative mechanisms of human erythrocyte invasion. PMID:24340114

Hester, James; Chan, Ernest R; Menard, Didier; Mercereau-Puijalon, Odile; Barnwell, John; Zimmerman, Peter A; Serre, David

2013-12-01

95

De Novo Assembly of a Field Isolate Genome Reveals Novel Plasmodium vivax Erythrocyte Invasion Genes  

PubMed Central

Recent sequencing of Plasmodium vivax field isolates and monkey-adapted strains enabled characterization of SNPs throughout the genome. These analyses relied on mapping short reads onto the P. vivax reference genome that was generated using DNA from the monkey-adapted strain Salvador I. Any genomic locus deleted in this strain would be lacking in the reference genome sequence and missed in previous analyses. Here, we report de novo assembly of a P. vivax field isolate genome. Out of 2,857 assembled contigs, we identify 362 contigs, each containing more than 5 kb of contiguous DNA sequences absent from the reference genome sequence. These novel P. vivax DNA sequences account for 3.8 million nucleotides and contain 792 predicted genes. Most of these contigs contain members of multigene families and likely originate from telomeric regions. Interestingly, we identify two contigs containing predicted protein coding genes similar to known Plasmodium red blood cell invasion proteins. One gene encodes the reticulocyte-binding protein gene orthologous to P. cynomolgi RBP2e and P. knowlesi NBPXb. The second gene harbors all the hallmarks of a Plasmodium erythrocyte-binding protein, including conserved Duffy-binding like and C-terminus cysteine-rich domains. Phylogenetic analysis shows that this novel gene clusters separately from all known Plasmodium Duffy-binding protein genes. Additional analyses showing that this gene is present in most P. vivax genomes and transcribed in blood-stage parasites suggest that P. vivax red blood cell invasion mechanisms may be more complex than currently understood. The strategy employed here complements previous genomic analyses and takes full advantage of next-generation sequencing data to provide a comprehensive characterization of genetic variations in this important malaria parasite. Further analyses of the novel protein coding genes discovered through de novo assembly have the potential to identify genes that influence key aspects of P. vivax biology, including alternative mechanisms of human erythrocyte invasion.

Hester, James; Chan, Ernest R.; Menard, Didier; Mercereau-Puijalon, Odile; Barnwell, John; Zimmerman, Peter A.; Serre, David

2013-01-01

96

Chlorhexidine Digluconate Effects on Planktonic Growth and Biofilm Formation in Some Field Isolates of Animal Bacterial Pathogens  

PubMed Central

Background: To study chlorhexidine digluconate disinfectant effects on planktonic growth and biofilm formation in some bacterial field isolates from animals. Objectives: The current study investigated chlorhexidine digluconate effects on planktonic growth and biofilm formation in some field isolates of veterinary bacterial pathogens. Materials and Methods: Forty clinical isolates of Escherichia coli, Salmonella serotypes, Staphylococcus. aureus and Streptococcus agalactiae (10 isolates for each) were examined for chlorhexidine digluconate effects on biofilm formation and planktonic growth using microtiter plates. In all of the examined strains in the presence of chlorhexidine digluconate, biofilm development and planktonic growth were affected at the same concentrations of the disinfectant. Results: Chlorhexidine digluconate inhibited the planktonic growth of different bacterial species at sub-MICs. But they were able to induce biofilm development of the E. coli, Salmonella spp., S. aureus and Str. agalactiae strains. Conclusions: Bacterial resistance against chlorhexidine is increasing. Sub-MIC doses of chlorhexidine digluconate can stimulate the formation of biofilm strains.

Ebrahimi, Azizollah; Hemati, Majid; Habibian Dehkordi, Saeed; Bahadoran, Shahab; Khoshnood, Sheida; Khubani, Shahin; Dokht Faraj, Mahdi; Hakimi Alni, Reza

2014-01-01

97

Phylogenetic positions of Mn 2+ -oxidizing bacteria and fungi isolated from Mn nodules in rice field subsoils  

Microsoft Academic Search

We isolated manganous ion (Mn2+) oxidizing bacteria and fungi from Mn nodules collected from two Japanese rice fields. The phylogenetic position of the Mn-oxidizing\\u000a bacteria and fungi was determined based on their 16S rDNA and 18S rDNA sequences, respectively. Among 39 bacterial and 25\\u000a fungal isolates, Burkholderia and Acremonium strains were the most common and dominant Mn2+-oxidizing bacteria and fungi,

Vita Ratri Cahyani; Jun Murase; Eiji Ishibashi; Susumu Asakawa; Makoto Kimura

2009-01-01

98

Multiple mechanisms account for variation in base-line sensitivity to azole fungicides in field isolates of Mycosphaerella graminicola.  

PubMed

Molecular mechanisms that account for variation in base-line sensitivity to azole fungicides were examined in a collection of twenty field isolates, collected in France and Germany, of the wheat pathogen Mycosphaerella graminicola (Fuckel) Schroeter. The isolates tested represent the wide baseline sensitivity to the azole fungicide tebuconazole described previously. The isolates were cross-sensitive to other azoles tested, such as cyproconazole and ketoconazole, but not to unrelated chemicals like cycloheximide, kresoxim-methyl or rhodamine 6G. Progenies from a genetic cross between an isolate with an intermediate and a high sensitivity to azoles displayed a continuous range of phenotypes with respect to cyproconazole sensitivity, indicating that variation in azole sensitivity in this haploid organism is polygenic. The basal level of expression of the ATP-binding cassette transporter genes MgAtr1-MgAtr5 from Mgraminicola significantly varied amongst the isolates tested, but no clear increase in the transcript level of a particular MgAtr gene was found in the less sensitive isolates. Cyproconazole strongly induced expression of MgAtr4, but no correlation between expression levels of this gene and azole sensitivity was observed. One isolate with intermediate sensitivity to azoles over-expressed CYP51, encoding cytochrome P450 sterol 14alpha-demethylase from M graminicola. Isolates with a low or high sensitivity to azoles were tested for accumulation of cyproconazole, but no clear correlation between reduced accumulation of the fungicide in mycelium and sensitivity to azoles was observed. Therefore, differences in accumulation cannot account exclusively for the variation in base-line sensitivity of the isolates to azoles. The results indicate that multiple mechanisms account for differences in base-line sensitivity to azoles in field isolates of M graminicola. PMID:14667055

Stergiopoulos, Ioannis; van Nistelrooy, Johannes G M; Kema, Gert H J; De Waard, Maarten A

2003-12-01

99

Excessive magnetic field flux density distribution from overhead isolated powerline conductors due to neutral line current.  

PubMed

Overhead isolated powerline conductors (hereinafter: "OIPLC") are the most compact form for distributing low voltage currents. From the known physics of magnetic field emission from 3-phase power lines, it is expected that excellent symmetry of the 120° shifted phase currents and where compact configuration of the 3-phase+neutral line exist, the phase current vectorial summation of the magnetic field flux density (MFFD) is expected to be extremely low. However, despite this estimation, an unexpectedly very high MFFD was found in at least three towns in Israel. This paper explains the reasons leading to high MFFD emissions from compact OIPLC and the proper technique to fix it. Analysis and measurement results had led to the failure hypothsis of neutral line poor connection design and poor grounding design of the HV-LV utility transformers. The paper elaborates on the low MFFD exposure level setup by the Israeli Environmental Protection Office which adopted a rather conservative precaution principal exposure level (2 mG averaged over 24 h). PMID:23675630

Netzer, Moshe

2013-06-01

100

Laboratory and field evaluations of the efficacy of a fast-killing baculovirus isolate from Spodoptera frugiperda.  

PubMed

Three biopesticide parameters were evaluated for a fast-killing isolate (3AP2) and a wild-type isolate (Sf3) of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV). Both isolates were evaluated for virus production using in vivo methods, for speed of kill based on bioassay of applications to glasshouse-grown and field-grown plants, and for residual insecticidal activity of unformulated virus and an encapsulating formulation to provide UV protection. Two inoculation rates comparing relative in vivo production of the isolates demonstrated 3AP2 inoculated larvae were significantly smaller than Sf3 inoculated larvae at death. At the lower inoculation rate, Sf3 inoculated larvae produced approximately twofold more occlusion bodies as the 3AP2 inoculated larvae. A model system of applications to cabbage plants and a bioassay to observe mortality of neonate S. frugiperda (J.E. Smith) after feeding on samples of treated leaves was used to evaluate speed of kill and residual insecticidal activity. The LT(50) for the 3AP2 isolate was at least 30 h less than the LT(50) for the Sf3 isolate when applied to either glasshouse-grown or field-grown plants. The spray-dried lignin encapsulating formulation provided similar benefits to both virus isolates when exposed to simulated sunlight in the laboratory and to natural sunlight in the field. For treatment applications to field grown cabbage in June, the half-life for efficacy of unformulated virus was <7.5 h compared with a half-life of >26.7 h for encapsulated virus. These results demonstrate that improved technologies can be combined to address characteristics which otherwise can limit the commercial potential of microbial-based biological insecticides. PMID:22100417

Behle, Robert W; Popham, Holly J R

2012-02-01

101

Taibaiella koreensis sp. nov., isolated from soil of a ginseng field.  

PubMed

A Gram-staining-negative, strictly aerobic, motile (by gliding), non-spore-forming and rod-shaped bacterial strain, designated THG-DT86(T), was isolated from soil of a ginseng field of Pocheon province in the Republic of Korea and its taxonomic position was investigated by a polyphasic approach. Growth occurred at 10-35 °C, at pH 6.5-8.5 and with 0-1.5?% (w/v) NaCl on trypticase soy agar. Flexirubin-type pigments were found to be present. On the basis of 16S rRNA gene sequence similarity, strain THG-DT86(T) was shown to belong to the genus Taibaiella and was related to Taibaiella smilacinae PTJT-5(T) (95.3?%). The G+C content of the genomic DNA was 50.1 mol%. The only isoprenoid quinone detected in strain THG-DT86(T) was menaquinone-7 (MK-7) and the only polyamine was homospermidine. The predominant fatty acids were iso-C15?:?0, iso-C17?:?0 3-OH, C16?:?0, iso-C15?:?1 G and iso-C17?:?0, and the major polar lipids were phosphatidylethanolamine, an unidentified aminophosphoglycolipid and an unidentified aminophospholipid. Phenotypic data and phylogenetic inference supported the affiliation of strain THG-DT86(T) to the genus Taibaiella, and a number of biochemical tests differentiated strain THG-DT86(T) from the recognized species of the genus Taibaiella. Therefore, the novel isolate represents a novel species, for which the name Taibaiella koreensis sp. nov. is proposed, with THG-DT86(T) as the type strain (?=?KACC 17171(T)?=?JCM 18823(T)). PMID:24425827

Son, Heung-Min; Kook, MooChang; Kim, Ju-Han; Yi, Tae-Hoo

2014-03-01

102

Molecular characterization of the complete genomes of two new field isolates of Cowpea chlorotic mottle virus, and their phylogenetic analysis.  

PubMed

Cowpea chlorotic mottle virus (CCMV, family Bromoviridae) is found worldwide and has been used as a model virus for a long time, but no data is available about the genetic diversity of field isolates. Recently, two new field isolates (Car1 and Car2) of CCMV obtained from cowpea showed distinct phenotypic symptoms when inoculated to cowpea. CCMV-Car1 induced severe mosaic and interveinal chlorosis, while CCMV-Car2 produced mild mottling and leaf rolling. Both isolates produced asymptomatic infection in Nicotiana benthamiana. The complete genome of both isolates was amplified by reverse transcription-polymerase chain reaction using specific primers against the CCMV sequences available in the GenBank database, cloned and sequenced. Both nucleotide and amino acid sequences were compared between the newly sequenced CCMV isolates and the three previously characterized CCMV strains (T, M1, and R). Phylogenetic analysis of the RNA 1 sequence showed that CCMV-Car1 was in a separate branch from the rest of the CCMV isolates while CCMV-Car2 grouped together with CCMV-R. On the basis of RNA 2 and RNA 3 sequences, two major groupings were obtained. One group included CCMV-Car1 and CCMV-Car2 isolates while the other contained CCMV-T, CCMV-M1, and CCMV-R strains. Recombination programs detected a potential recombination event in the RNA 1 sequence of CCMV-Car2 isolate but not in RNA 2 and RNA 3 sequences. The results showed that both mutations and recombination have played an important role in the genetic diversity of these two new isolates of CCMV. PMID:21537997

Ali, Akhtar; Shafiekhani, Maryam; Olsen, Jolie

2011-08-01

103

Phylogenetic analysis of field isolates of feline calcivirus (FCV) in Japan by sequencing part of its capsid gene.  

PubMed

The molecular epidemiology of the infectious disease caused by feline calcivirus (FCV) in Japan was investigated by analysing the phylogenetic relationship among 21 Japanese field isolates, including the F4 strain, and 30 global isolates. Parts of the capsid gene (B-F) of the isolates were amplified by RT-PCR, and the amino acid sequences were compared with those from the global isolates. Thirty-seven and 14 out of a total of 51 isolates were clustered into two distinct genogroups, I and II respectively, by UPGMA and NJ analysis. Seven of the 21 Japanese isolates (33%) fell into group I together with 30 global isolates, while the other 14 Japanese isolates (67%) belonged to group II. The bootstrap repetition analysis of groups I and II formed by the NJ method gave a value of 99.00%. The 14 latter Japanese isolates were clearly separated from the isolates in group I, and they were different from any previously known FCV, forming a new genogroup, which implies that this lineage has been confined to Japan. Comparing the amino acid sequences shared by groups I and II, the amino acid at position 377 in B region was asparagine (Asn or Asp (NH2)) in group I, while it was lysine (Lys) in all the strains in group II. Similarly, the amino acid at position 539 in the F region was alanine (Ala) or proline (Pro) in group I, while it was valine (Val) in group II; glycine (Gly) at position 557 in group I was serine (Ser) in Group II; and phenylalanine (Phe) or leucine (Leu) at position 566 in genogroup I was tyrosine (Tyr) in group II. PMID:12090292

Sato, Y; Ohe, K; Murakami, M; Fukuyama, M; Furuhata, K; Kishikawa, S; Suzuki, Y; Kiuchi, A; Hara, M; Ishikawa, Y; Taneno, A

2002-04-01

104

Determination of discriminating dose and evaluation of amitraz resistance status in different field isolates of Rhipicephalus (Boophilus) microplus in India.  

PubMed

Field tick isolates of Rhipicephalus (Boophilus) microplus were collected from eleven districts located in the northern and eastern states of India to access the resistance status to "Amitraz". Adult immersion test was optimized using laboratory reared acaricide susceptible IVRI-I line and minimum effective concentration was determined as 487.7 ppm with 95 % confidence interval of 455.8-521.8. The discriminating concentration was determined as 975.4 ppm and was tested on female ticks collected by two stage stratified sampling from organized dairy farms and villages. Based on three variables, viz.,mortality, egg masses and reproductive index, the resistance level was categorized.Resistance to amitraz was detected at level I in 3 isolates (RF = 1.56-5.0), at level II in 6 isolates (RF = 9.3-23.3) and at level III in 1 isolate (RF = 27.3) whereas one isolate was found susceptible. The highest resistance was found in the SKR isolate (RF = 27.3) and minimal resistance was detected in the N-24P isolate (RF = 1.56). These experimental data will help in designing tick control strategy which is suffering from acaricide failure and to overcome development of resistance in ticks. PMID:24659517

Kumar, Sachin; Sharma, Anil Kumar; Ray, D D; Ghosh, Srikant

2014-07-01

105

Field Studies Reveal Strong Postmating Isolation between Ecologically Divergent Butterfly Populations  

PubMed Central

Gene flow between populations that are adapting to distinct environments may be restricted if hybrids inherit maladaptive, intermediate phenotypes. This phenomenon, called extrinsic postzygotic isolation (EPI), is thought to play a critical role in the early stages of speciation. However, despite its intuitive appeal, we know surprisingly little about the strength and prevalence of EPI in nature, and even less about the specific phenotypes that tend to cause problems for hybrids. In this study, we searched for EPI among allopatric populations of the butterfly Euphydryas editha that have specialized on alternative host plants. These populations recall a situation thought typical of the very early stages of speciation. They lack consistent host-associated genetic differentiation at random nuclear loci and show no signs of reproductive incompatibility in the laboratory. However, they do differ consistently in diverse host-related traits. For each of these traits, we first asked whether hybrids between populations that use different hosts (different-host hybrids) were intermediate to parental populations and to hybrids between populations that use the same host (same-host hybrids). We then conducted field experiments to estimate the effects of intermediacy on fitness in nature. Our results revealed strong EPI under field conditions. Different-host hybrids exhibited an array of intermediate traits that were significantly maladaptive, including four behaviors. Intermediate foraging height slowed the growth of larvae, while intermediate oviposition preference, oviposition site height, and clutch size severely reduced the growth and survival of the offspring of adult females. We used our empirical data to construct a fitness surface on which different-host hybrids can be seen to fall in an adaptive valley between two peaks occupied by same-host hybrids. These findings demonstrate how ecological selection against hybrids can create a strong barrier to gene flow at the early stages of adaptive divergence.

McBride, Carolyn S.; Singer, Michael C.

2010-01-01

106

DNA Hybridization Probe for Use in Determining Restricted Nodulation among Bradyrhizobium japonicum Serocluster 123 Field Isolates  

PubMed Central

Several soybean plant introduction (PI) genotypes have recently been described which restrict nodulation of Bradyrhizobium japonicum serocluster 123 in an apparently serogroup-specific manner. While PI 371607 restricts nodulation of strains in serogroup 123 and some in serogroup 127, those in serogroup 129 are not restricted. When DNA regions within and around the B. japonicum I-110 common nodulation genes were used as probes to genomic DNA from the serogroup strains USDA 123, USDA 127, and USDA 129, several of the probes differentially hybridized to the nodulation-restricted and -unrestricted strains. One of the gene regions, cloned in plasmid pMJS12, was subsequently shown to hybridize to 4.6-kilobase EcoRI fragments from DNAs from nodulation-restricted strains and to larger fragments in nodulation-unrestricted strains. To determine if the different hybridization patterns could be used to predict nodulation restriction, we hybridized pMJS12 to EcoRI-digested genomic DNAs from uncharacterized serocluster 123 field isolates. Of the 36 strains examined, 15 were found to have single, major, 4.6-kilobase hybridizing EcoRI fragments. When tested for nodulation, 80% (12 of 15) of the strains were correctly predicted to be restricted for nodulation of the PI genotypes. In addition, hybridization patterns obtained with pMJS12 and nodulation phenotypes on PI 371607 indicated that there are at least three types of serogroup 127 strains. Our results suggest that the pMJS12 gene probe may be useful in selecting compatible host-strain combinations and in determining the suitability of field sites for the placement of soybean genotypes containing restrictive nodulation alleles. Images

Sadowsky, Michael J.; Cregan, Perry B.; Keyser, Harold H.

1990-01-01

107

Relationships among isolates of Botrytis cinerea collected from greenhouses and field locations in Alberta, based on RAPD analysis  

Microsoft Academic Search

This study was undertaken to determine whether there was genetic diversity among isolates of Botrytis cinerea (teleomorph Botryotinia fuckeliana) collected from greenhouses and field locations in Alberta, Canada, and whether genetic diversity could be attributed to collection location and (or) host plant species. The study was conducted to provide basic information that is intended for use in developing effective greenhouse

J. T. Calpas; M. N. Konschuh; C. C. Toews; J. P. Tewari

2006-01-01

108

Genetic variation in open reading frame 2 of field isolates and laboratory strains of equine arteritis virus  

Microsoft Academic Search

The open reading frame 2 (ORF2) of three laboratory strains, the live attenuated vaccine virus, and 18 field isolates of equine arteritis virus (EAV) from Europe and North America was sequenced. The ORF2 of EAV encodes the Gs protein that is abundantly expressed in infected cells but constitutes less than 2% of the virion protein mass. Variation of ORF2 among

Jodi F. Hedges; Udeni B. R. Balasuriya; Peter J. Timoney; William H. McCollum; N. James MacLachlan

1996-01-01

109

Assessment of Plasmodium falciparum resistance to ferroquine (SSR97193) in field isolates and in W2 strain under pressure  

PubMed Central

Background Ferroquine (FQ), or SSR97193, is a novel antimalarial drug currently in phase I clinical trials. FQ is a unique organometallic compound designed to overcome the chloroquine (CQ) resistance problem. FQ revealed to be equally active on CQ-sensitive and CQ-resistant Plasmodium falciparum laboratory strains and field isolates. FQ is also curative on rodent malaria parasites. As FQ will be tested in patients, the potential for resistance to this drug was evaluated. Methods The relationship between CQ-resistant transporter gene genotype and susceptibility to FQ were studied in 33 Cambodian P. falciparum field isolates previously studied for their in vitro response to CQ. In parallel, the ability of the CQ-resistant strain W2, to become resistant to FQ under drug pressure was assessed. Results The IC50 values for FQ in field isolates were found to be unrelated to mutations occurring in the P. falciparum chloroquine resistance transporter (PfCRT) or to the level of expression of the corresponding mRNA. In vitro, under a drug pressure of 100 nM of FQ, transient survival was observed in only one of two experiments. Conclusion Field isolates studies and experimental drug pressure experiments showed that FQ overcomes CQ resistance, which reinforces the potential of this compound as a new antimalarial drug.

Daher, Wassim; Biot, Christophe; Fandeur, Thierry; Jouin, Helene; Pelinski, Lydie; Viscogliosi, Eric; Fraisse, Laurent; Pradines, Bruno; Brocard, Jacques; Khalife, Jamal; Dive, Daniel

2006-01-01

110

Isolation and characterization of Methanoculleus receptaculi sp. nov. from Shengli oil field, China.  

PubMed

Three strictly anaerobic, thermophilic methanogens (ZC-2T, ZC-3 and ZC-6) were isolated from Shengli oil field, China. The 16S rRNA gene sequences of the three strains were nearly identical, possessing > 99.8% sequence similarity. They also possessed high sequence similarity, 97.4%, to Methanoculleus palmolei strain INSLUZ(T) (97.4% and 97.5%, respectively), indicating that they represented a novel species within the genus Methanoculleus. Cells of strain ZC-2T were nonmotile cocci, 0.8-1.7 microm in diameter, and always occurred singly or in pairs. The three strains used H2/CO2 or sodium formate as substrates for methanogenesis but not sodium acetate, trimethylamine, monomethylamine, ethanol, dimethyl sulfide, isopropanol, isobutanol, butan-2-ol or H2/CO. Optimum growth of strain ZC-2T occurred in the presence of 0.2 M NaCl, pH 7.5-7.8 and temperature 50-55 degrees C with a specific growth rate of 0.084 h(-1). The mol% G+C content of the genomic DNA was 55.2 mol%. Based on these phenotypic and phylogenetic characteristics, strains ZC-2T, ZC-3 and ZC-6 are proposed to represent a novel species in the genus Methanoculleus and named Methanoculleus receptaculi sp. nov. The type strain is ZC-2T (CGMCC 1.5087T=DSM 18860T). PMID:18557787

Cheng, Lei; Qiu, Tian-Lei; Li, Xia; Wang, Wei-Dong; Deng, Yu; Yin, Xiao-Bo; Zhang, Hui

2008-08-01

111

Purification and characterization of carboxymethyl cellulase from Bacillus sp. isolated from a paddy field.  

PubMed

A microorganism hydrolyzing carboxymethyl cellulose was isolated from a paddy field and identified as Bacillus sp. Production of cellulase by this bacterium was found to be optimal at pH 6.5, 37 degrees C and 150 rpm of shaking. This cellulase was purified to homogeneity by the combination of ammonium sulphate precipitation, DEAE cellulose, and sephadex G-75 gel filtration chromatography. The cellulase was purified up to 14.5 fold and had a specific activity of 246 U/mg protein. The enzyme was a monomeric cellulase with a relative molecular mass of 58 kDa, as determined by SDS-PAGE. The enzyme exhibited its optimal activity at 50 degrees C and pH 6.0. The enzyme was stable in the pH range of 5.0 to 7.0 and its stability was maintained for 30 min at 50 degrees C and its activity got inhibited by Hg2+, Cu2+, Zn2+, Mg2+, Na2+, and Ca2+. PMID:22708346

Vijayaraghavan, Ponnuswamy; Vincent, S G Prakash

2012-01-01

112

Crystal field splitting of rovibrational transitions of water monomers isolated in solid parahydrogen.  

PubMed

We report polarized infrared absorption spectra of water isotopologues isolated in solid parahydrogen (pH2) which reveal the crystal field induced splittings of the 1 01<--0 00 R(0) lines in the nu1 HDO, nu3 D2O, nu3 HDO, and nu3 H2O fundamental bands. For annealed pH2 solids, these spectra also reveal a strong alignment of the hexagonal-close-packed crystallites' c axes with the deposition substrate surface normal. This alignment effect explains our failure to detect the parallel-polarized components of these R(0) lines in spectra of pH2 solids produced on a transparent deposition substrate [M. E. Fajardo et al., J. Mol. Struct. 695, 111 (2004)]. This lesson applies more generally to comparison of solid pH2 spectra obtained in different laboratories. The spectra are consistent with water monomers existing in solid pH2 as very slightly hindered rotors. The individual components of the R(0) absorption lines show a Lorentzian lineshape, with vibrational depopulation the most important source of line broadening. PMID:18190202

Fajardo, Mario E; Lindsay, C Michael

2008-01-01

113

Variovorax ginsengisoli sp. nov., a denitrifying bacterium isolated from soil of a ginseng field.  

PubMed

A Gram-negative, aerobic or facultatively anaerobic, non-spore-forming, motile, rod-shaped bacterium (strain Gsoil 3165(T)) was isolated from soil of a ginseng field in Pocheon, South Korea. Its taxonomic position was determined by using a polyphasic approach. On the basis of 16S rRNA gene sequence analysis, strain Gsoil 3165(T) was shown to belong to the family Comamonadaceae, class Betaproteobacteria, and was related most closely to the type strains of Variovorax boronicumulans (98.9 % similarity), Variovorax paradoxus (98.3 %), Variovorax soli (98.2 %) and Variovorax dokdonensis (96.6 %). Levels of 16S rRNA gene sequence similarity between strain Gsoil 3165(T) and the type strains of other species in the family Comamonadaceae were less than 97.0 %. The G+C content of the genomic DNA of strain Gsoil 3165(T) was 66 mol%. Phenotypic and chemotaxonomic data (Q-8 as the major ubiquinone; C(16 : 0) and C(17 : 0) cyclo as major fatty acids) supported the affiliation of strain Gsoil 3165(T) to the genus Variovorax. The results of physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain Gsoil 3165(T) from recognized Variovorax species. Gsoil 3165(T) is therefore considered to represent a novel species of the genus Variovorax, for which the name Variovorax ginsengisoli sp. nov. is proposed. The type strain is Gsoil 3165(T) (=KCTC 12583(T) =LMG 23392(T)). PMID:19684323

Im, Wan-Taek; Liu, Qing-Mei; Lee, Kang-Jin; Kim, Se-Young; Lee, Sung-Taik; Yi, Tae-Hoo

2010-07-01

114

Improved protocol for isolation of Campylobacter spp. from retail broiler meat and use of pulsed field gel electrophoresis for the typing of isolates.  

PubMed

To improve the detection of Campylobacter spp. in retail broiler meat, a reference method (R subsamples) based on the enrichment of 25 g of meat in Bolton broth at 42°C under microaerobiosis was compared with an alternative method (A subsamples) consisting in the rinsing of meat samples for 30s in buffered peptone water with antimicrobials with incubation at 42°C under aerobiosis. One piece of meat (breasts, tenderloins and thighs) was rinse in experiment 1 (A1) and two pieces in experiment 2 (A2). Campylobacter spp. were isolated on agar plates and identified by PCR. Retail samples in Alabama had less prevalence (P ? 0.05) than samples in the state of Washington. The percentage of positive was higher (P ? 0.05) in A than in R subsamples and rinsing two pieces of meat yielded the highest percentage of positive subsamples. R subsamples showed variations in the prevalence by product. However, A subsamples had similar prevalence of positives among products compare to the result from reference method. More Campylobacter coli isolates were collected in A2 subsamples. Pulse field gel electrophoresis (PFGE) was used as subtyping method to study the genome similarity among the isolates from all methods. A larger diversity of isolates were detected by PFGE in A2 subsamples. Denaturing gradient gel electrophoresis analysis suggested that the initial bacterial populations of the meat samples impact the final bacterial profile after enrichment. Rinsing broiler meats was less time consuming, required less sample preparation and was more sensitive than the reference method for the isolation of naturally occurring Campylobacter spp. This new method could help with epidemiological and intervention studies to control Campylobacter spp. PMID:23545445

Oyarzabal, Omar A; Williams, Aretha; Zhou, Ping; Samadpour, Mansour

2013-10-01

115

Pedobacter seoulensis sp. nov., isolated from soil of a bamboo field.  

PubMed

A Gram-stain negative, strictly aerobic, motile by gliding, rod-shaped and yellow pigmented strain THG-G12T was isolated from soil of a bamboo field in Seoul, Republic of Korea. Strain THG-G12T was observed to grow well at 20–28 °C and pH 7.0–7.5 in the absence of NaCl on nutrient agar. Based on 16S rRNA gene sequence comparisons, strain THG-G12T was found to be most closely related to Pedobacter ginsengisoli Gsoil 104T (97.5 % sequence similarity), Pedobacter steynii WB2.3-45T (97.4 %), Pedobacter metabolipauper WB2.3-71T (97.2 %), Pedobacter nyackensis NWG-II14T (97.2 %), Pedobacter caeni LMG 22862T (97.1 %) and Pedobacter duraquae WB2.1-25T (97.0 %), but DNA relatedness between strain THG-G12T and its phylogenetically closest neighbours was below 9.5 %. The G+C content of the genomic DNA was determined to be 39.9 mol%. The only isoprenoid quinone detected in strain THG-G12T was menaquinone-7 (MK-7). The major component in the polyamine pattern was sym-homospermidine. The major polar lipids were found to be phosphatidylethanolamine, unidentified phosphoglycolipids, unidentified aminophosphoglycolipids, unidentified aminolipids and unidentified lipids. Strain THG-G12T showed the presence of two ceramide phosphorylethanolamines (CerPE-2? and CerPE-2?), dihydrosphingosines and an unidentified ceramide as the major ceramide. The major fatty acids were identified as summed feature 3 (as defined by the MIDI system; C16:1 ?7c and/or C16:1 ?6c) and iso-C15:0. These data support the affiliation of strain THG-G12T to the genus Pedobacter. The results of physiological and biochemical tests enabled strain THG-G12T to be differentiated genotypically and phenotypically from the recognized species of the genus Pedobacter. Therefore, the novel isolate represents a novel species, for which the name Pedobacter seoulensis sp. nov. is proposed, with THG-G12T as the type strain (=KACC 17529T =JCM 19363T). PMID:24659428

Ngo, Hien T T; Son, Heung-Min; Park, Sang-Yong; Kim, Ki-Young; Yi, Tae-Hoo

2014-05-01

116

Responses of broiler chickens orally challenged with Clostridium perfringens isolated from field cases of necrotic enteritis.  

PubMed

The present study examines the responses of broiler chickens to oral administration of Clostridium perfringens freshly isolated from field cases of necrotic enteritis (NE). The challenge studies included long-term exposure and short-term exposure, factored in with dietary and management variables including high levels of dietary components such as fish meal, meat meal, abrupt change of feed, and fasting. In the long-term exposure trials, the birds were orally inoculated daily, with 1 ml (1.0 or 2 x 10(8) CFU/ml) of an overnight culture of C. perfringens for 7 days. Short-term exposure trials involved challenge with 1 ml (3 x 10(10) CFU/ml) administered as a single dose. The responses of broilers to orally administered C. perfingens under laboratory controlled conditions are presented and discussed in the context of authentic field cases of necrotic enteritis. None of the challenge trials produced overt clinical signs of NE and there were no mortalities associated with oral exposure to high doses of C. perfringens. However, many of the challenged birds showed distinctly pronounced pathological changes in the intestinal tissue. On gross examination the responses in birds challenged orally with C. perfringens could be placed into two categories: (1) no apparent pathological changes in the intestinal tissue and (2) sub-clinical inflammatory responses with focal, multi-focal, locally extensive, or disseminated distribution throughout various sections of duodenum, jejunum, ileum, and ceca. In birds that responded with intestinal lesions, hyperemia and occasional hemorrhages were the main gross changes. In some birds, the mucosa was covered with a brownish material, but typically, the mucosa was lined by yellow or greenish, loosely adherent material. Mild gross changes were seen in some control birds, but both qualitatively and quantitatively, the lesions were distinctly more pronounced in the challenged birds. Upon histological examination, none of the experimentally exposed birds showed overt mucosal necrosis typical of field cases of NE, but typically the lamina propria was hyperemic and infiltrated with numerous inflammatory cells. Most significant changes were seen at the interface of the basal domain of enterocytes and lamina propria. Multifocally, these areas were extensively edematous, allowing for the substantial disturbance of the structural integrity between the lamina propria and the enterocytes. The lesions observed in the present study were consistently reproduced in all of our challenge trials, hence these responses may signify newly emerging patterns of sub-clinical enteric disorders in contemporary strains of poultry. The pathological changes observed in broilers challenged orally with C. perfringens in the present study, differ significantly from those reported previously, and must be clearly differentiated from those described in cases of NE or ulcerative enteritis. Although no overt necrosis of the intestinal mucosa typical of field cases of NE were observed in the present study, the birds challenged with C. perfringens showed strong inflammatory reaction to the introduced pathogens. The distinct features of the microscopic lesions were changes involving apparently normal enterocytes at the interface of the basal domain of villar epithelia and lamina propria. Although the pathological changes in the intestinal tissues observed in our trials appear to be rather subtle when compared to field cases of NE, the nature of these lesions suggest a significant negative effect on the digestive physiology of intestinal mucosa. PMID:16337982

Olkowski, A A; Wojnarowicz, C; Chirino-Trejo, M; Drew, M D

2006-08-01

117

Prophage Sequences Defining Hot Spots of Genome Variation in Salmonella enterica Serovar Typhimurium Can Be Used To Discriminate between Field Isolates  

Microsoft Academic Search

Sixty-one Salmonella enterica serovar Typhimurium isolates of animal and human origin, matched by phage type, antimicrobial resistance pattern, and place of isolation, were analyzed by microbiological and molecular techniques, including pulsed-field gel electrophoresis (PFGE) and plasmid profiling. PFGE identified 10 profiles that clustered by phage type and antibiotic resistance pattern with human and animal isolates distributed among different PFGE profiles.

Fiona J. Cooke; John Wain; Maria Fookes; Alasdair Ivens; Nicholas Thomson; Derek J. Brown; E. John Threlfall; George Gunn; Geoffrey Foster; Gordon Dougan

118

Radiotolerance of microorganisms isolated from radiation fields on a university campus: implications for shallow subsurface growth of microorganisms on Mars  

NASA Astrophysics Data System (ADS)

The surface of Mars is exposed to higher levels of solar and galactic cosmic ray irradiation than Earth due to its very weak magnetic field. Thus, microorganisms that could possibly survive in the shallow subsurface of Mars would likely be radiotolerant. To better understand microorganisms that might reside in this environment of Mars, a number of isolates were obtained from the area around a gamma-radiation source, 137Cs, located on the UMR campus. Radiation sensitivity assays were performed on the isolates as well as on the common bacterium, E. coli. All the organisms tested were able to withstand exposures up to 20 Gy. The E. coli control did not survive exposures of 200 Gy, while the isolate designated 1B-1 could. Another isolate, Cont-1, also withstood this exposure. Each of the isolates produced white growth on solid medium and their cells are rod-shaped. The study of these isolates and similar organisms could enhance our knowledge of these unique extremophilic bacteria and might provide insight into the microorganisms that could be present in the shallow subsurface of Mars.

Mormile, Melanie R.; Elmer, Jacob J.; Spychala, Scott J.

2007-10-01

119

Antitrypanosomal activity of aloin and its derivatives against Trypanosoma congolense field isolate  

PubMed Central

Background There is an urgent need for the development of new, cheap, safe and highly effective drugs against African trypanosomiasis that affects both man and livestock in sub-Saharan Africa including Ethiopia. In the present study the exudate of Aloe gilbertii, an endemic Aloe species of Ethiopia, aloin, aloe-emodin and rhein were tested for their in vitro and in vivo antitrypanosomal activities against Trypanosoma congolense field isolate. Aloin was prepared from the leaf exudate of A. gilbertii by acid catalyzed hydrolysis. Aloe-emodin was obtained by oxidative hydrolysis of aloin, while rhein was subsequently derived from aloe-emodin by oxidation. In vitro trypanocidal activity tests were conducted on parasites obtained from infected mice, while mice infected with T. congolense were used to evaluate in vivo antitrypanosomal activity of the test substances. Results Results of the study showed that all the test substances arrested parasites motility at effective concentration of 4.0 mg/ml within an incubation period ranging from 15 to 40 min. Moreover, the same concentration of the test substances caused loss of infectivity of the parasites to mice during 30 days observation period. Among the tested substances, rhein showed superior activity with minimum inhibitory concentration (MIC) of 0.4 mg/ml. No adverse reactions were observed when the test substances were administered at a dose of 2000 mg/kg. Rhein at doses of 200 and 400 mg/kg, and the exudate, aloin and aloe-emodin at a dose of 400 mg/kg reduced the level of parasitaemia significantly (P?

2014-01-01

120

Terminal voltage control of a wind turbine driven isolated induction generator using stator oriented field control  

Microsoft Academic Search

This paper presents the voltage build up process and terminal voltage control in an isolated wind powered induction generator driven by a variable speed wind turbine using stator flux oriented vector control. Here three-phase induction generator is excited using a PWM inverter\\/rectifier connected to a single capacitor on the DC side. Wind powered isolated induction generators have an input, wind,

D. Seyoum; M. F. Rahman; C. Grantham

2003-01-01

121

Comparison of Mycoplasma agalactiae isolates by pulsed field gel electrophoresis, SDS-PAGE and immunoblotting  

Microsoft Academic Search

We have analyzed 81 isolates of Mycoplasma agalactiae from four different regions of Italy between 1990 and 1995 in order to identify antigenic differences through SDS-PAGE and Western blotting and chromosomal DNA restriction endonuclease cleavage pattern differences. Antigenic variability in M. agalactiae isolates was investigated analyzing hydrophobic membrane protein fractions by immunoblotting using pooled sheep antiserum from naturally infected sheep.

Sebastiana Tola; Graziano Idini; Daniela Manunta; Ida Casciano; angela M. Rocchigiani; Antonio Angioi; Guido Leori

1996-01-01

122

Heterogeneity of molecular resistance patterns in antimony-resistant field isolates of leishmania species from the Western mediterranean area.  

PubMed

Antimonials remain the first-line treatment for the various manifestations of leishmaniasis in most areas where the disease is endemic, and increasing cases of therapeutic failure associated with parasite resistance have been reported. In this study, we assessed the molecular status of 47 clinical isolates of Leishmania causing visceral and cutaneous leishmaniasis from Algeria, Tunisia, and southern France. In total, we examined 14 genes that have been shown to exhibit significant variations in DNA amplification, mRNA levels, or protein expression with respect to resistance to antimonials. The gene status of each clinical isolate was assessed via qPCR and qRT-PCR. We then compared the molecular pattern against the phenotype determined via an in vitro sensitivity test of the clinical isolates against meglumine antimoniate, which is considered the reference technique. Our results demonstrate significant DNA amplification and/or RNA overexpression in 56% of the clinical isolates with the resistant phenotype. All clinical isolates that exhibited significant overexpression of at least 2 genes displayed a resistant phenotype. Among the 14 genes investigated, 10 genes displayed either significant amplification or overexpression in at least 1 clinical isolate; these genes are involved in several metabolic pathways. Moreover, various gene associations were observed depending on the clinical isolates, supporting the multifactorial nature of Leishmania resistance. Molecular resistance features were found in the 3 Leishmania species investigated (Leishmania infantum, Leishmania major, and Leishmania killicki). To our knowledge, this is the first report of the involvement of molecular resistance genes in field isolates of Leishmania major and Leishmania killicki with the resistance phenotype. PMID:24913173

Jeddi, Fakhri; Mary, Charles; Aoun, Karim; Harrat, Zoubir; Bouratbine, Aïda; Faraut, Françoise; Benikhlef, Rezika; Pomares, Christelle; Pratlong, Francine; Marty, Pierre; Piarroux, Renaud

2014-08-01

123

Isolated sub-30-attosecond pulse generation using a multicycle two-color chirped laser and a static electric field  

NASA Astrophysics Data System (ADS)

We present a theoretical investigation of high-order harmonic generation in a chirped two-color laser field, which is synthesized by a 10-fs/800-nm fundamental chirped pulse and a 10-fs/1760-nm subharmonic pulse. It is shown that a supercontinuum can be produced using the multicycle two-color chirped field. However, the supercontinuum reveals a strong modulation structure, which is not good for the generation of an isolated attosecond pulse. By adding a static electric field to the multicycle two-color chirped field, not only the harmonic cutoff is extended remarkably, but also the quantum paths of the high-order harmonic generation (HHG) are modified significantly. As a result, both the extension of the supercontinuum and the selection of a single quantum path are achieved, producing an isolated 23-as pulse with a bandwidth of about 170.6 eV. Furthermore, the influences of the laser intensities on the supercontinuum and isolated attosecond pulse generation are investigated.

Zhang, Gang-Tai

2014-04-01

124

Isolated attosecond pulse generation from pre-excited medium with a chirped and chirped-free two-color field.  

PubMed

We theoretically investigate the isolated attosecond pulse generation from pre-excited medium with a chirped and chirped-free two-color field. It is found that the large initial population of the excited state can lead to the high density of the free electrons in the medium and the large distortion of the driving laser field after propagation, though it benefits large enhancement of harmonic intensity in single atom response. These effects can weaken the phase-match of the macroscopic supercontinuum. On the contrary, the small initial population of 4% can generate well phase-match intense supercontinuum. We also investigate an isolated attosecond pulse generation by using a filter centered on axis to select the harmonics in the far field. Our results reveal that the radius of the spatial filter should be chosen to be small enough to reduce the duration of the isolated attosecond pulse due to the curvature effect of spatiotemporal profiles of the generated attosecond pulses in the far field. PMID:22535063

Du, Hongchuan; Luo, Laoyong; Wang, Xiaoshan; Hu, Bitao

2012-04-23

125

Isolation and Characterization of Strains CVO and FWKO B, Two Novel Nitrate-Reducing, Sulfide-Oxidizing Bacteria Isolated from Oil Field Brine  

PubMed Central

Bacterial strains CVO and FWKO B were isolated from produced brine at the Coleville oil field in Saskatchewan, Canada. Both strains are obligate chemolithotrophs, with hydrogen, formate, and sulfide serving as the only known energy sources for FWKO B, whereas sulfide and elemental sulfur are the only known electron donors for CVO. Neither strain uses thiosulfate as an energy source. Both strains are microaerophiles (1% O2). In addition, CVO grows by denitrification of nitrate or nitrite whereas FWKO B reduces nitrate only to nitrite. Elemental sulfur is the sole product of sulfide oxidation by FWKO B, while CVO produces either elemental sulfur or sulfate, depending on the initial concentration of sulfide. Both strains are capable of growth under strictly autotrophic conditions, but CVO uses acetate as well as CO2 as its sole carbon source. Neither strain reduces sulfate; however, FWKO B reduces sulfur and displays chemolithoautotrophic growth in the presence of elemental sulfur, hydrogen, and CO2. Both strains grow at temperatures between 5 and 40°C. CVO is capable of growth at NaCl concentrations as high as 7%. The present 16s rRNA analysis suggests that both strains are members of the epsilon subdivision of the division Proteobacteria, with CVO most closely related to Thiomicrospira denitrifcans and FWKO B most closely related to members of the genus Arcobacter. The isolation of these two novel chemolithotrophic sulfur bacteria from oil field brine suggests the presence of a subterranean sulfur cycle driven entirely by hydrogen, carbon dioxide, and nitrate.

Gevertz, Diane; Telang, Anita J.; Voordouw, Gerrit; Jenneman, Gary E.

2000-01-01

126

Development of a selective myclobutanil agar (MBA) medium for the isolation of Fusarium species from asparagus fields.  

PubMed

A new selective myclobutanil agar medium for the detection of Fusarium, species is proposed. Ten media formulations based on various selective agents (pentachloronitrobenzene (PCNB), Rose Bengal, malachite green, sodium hypochlorite, captan, benomyl, chlorotalonil, myclobutanil, thiram, and cupric sulfate) were compared. First, mycelium growth and colony appearance of Alternaria alternata, Aspergillus flavus, Cladosporium cladosporioides, Epicoccum nigrum, Fusarium sp., Fuisarium solani, Fusarium moniliforme, Fusarium oxysporum f.sp. dianthi, Penicillium sp., and Trichoderma viride isolates were compared. Second, the ability of the different media to isolate and enumerate fusaria from asparagus fields was evaluated. The myclobutanil-based medium showed the highest selectivity to Fusarium spp. growth but required a slightly longer incubation time (>5 d) than peptone-pentachloronitrobenzene-based agar (PPA) (< 5 d). PPA allowed a faster fusaria growth but also permited the growth of other moulds. The other media were less selective and did not allow to isolate fusaria or to differenciate them from other growing fungi. PMID:12455616

Vujanovic, Vladimir; Hamel, Chantal; Jabaji-Hare, Suha; St-Arnaud, Marc

2002-09-01

127

Species diversity and toxigenic potential of Fusarium graminearum complex isolates from maize fields in northwest Argentina.  

PubMed

Members of the Fusarium graminearum species complex (Fg complex) are the causal agents of ear rot in maize and Fusarium head blight of wheat and other small grain cereals. The potential of these pathogens to contaminate cereals with trichothecene mycotoxins is a health risk for both humans and animals. A survey of ear rot isolates from maize collected in northwest Argentina recovered 66 isolates belonging to the Fg complex. A multilocus genotyping (MLGT) assay for determination of Fg complex species and trichothecene chemotypes was used to identify 56 of these isolates as F. meridionale and 10 isolates as F. boothii. F. meridionale was fixed for the nivalenol (NIV) chemotype, and all of the F. boothii isolates had the 15-acetyldeoxynivalenol (15ADON) chemotype. The results of genetic diversity analysis based on nine variable number tandem repeat (VNTR) loci supported the hypothesis of genetic isolation between F. meridionale and F. boothii, and provided little evidence of geographic substructure among populations of the dominant pathogen species, F. meridionale. This is the first study to indicate that F. meridionale and F. boothii may play a substantial role in the infection and trichothecene contamination of maize in Argentina. In addition, dominance of the NIV chemotype among Fg complex isolates from Argentina is unprecedented, and of significant concern to food safety and animal production. PMID:21277035

Sampietro, D A; Díaz, C G; Gonzalez, V; Vattuone, M A; Ploper, L D; Catalan, C A N; Ward, T J

2011-01-31

128

The imprint of the crustal magnetic field on the thermal spectra and pulse profiles of isolated neutron stars  

NASA Astrophysics Data System (ADS)

Isolated neutron stars (NSs) show a bewildering variety of astrophysical manifestations, presumably shaped by the magnetic field strength and topology at birth. Here, using state-of-the-art calculations of the coupled magnetic and thermal evolution of NSs, we compute the thermal spectra and pulse profiles expected for a variety of initial magnetic field configurations. In particular, we contrast models with purely poloidal magnetic fields to models dominated by a strong internal toroidal component. We find that, while the former displays double-peaked profiles and very low pulsed fractions, in the latter, the anisotropy in the surface temperature produced by the toroidal field often results in a single pulse profile, with pulsed fractions that can exceed the 50-60 per cent level even for perfectly isotropic local emission. We further use our theoretical results to generate simulated `observed' spectra, and show that blackbody (BB) fits result in inferred radii that can be significantly smaller than the actual NS radius, even as low as ˜1-2 km for old NSs with strong internal toroidal fields and a high absorption column density along their line of sight. We compute the size of the inferred BB radius for a few representative magnetic field configurations, NS ages and magnitudes of the column density. Our theoretical results are of direct relevance to the interpretation of X-ray observations of isolated NSs, as well as to the constraints on the equation of state of dense matter through radius measurements.

Perna, Rosalba; Viganò, Daniele; Pons, José A.; Rea, Nanda

2013-09-01

129

Downregulation of Mitogen-Activated Protein Kinase 1 of Leishmania donovani Field Isolates Is Associated with Antimony Resistance  

PubMed Central

Emergence of resistance to pentavalent antimonials has become a severe obstacle in the treatment of visceral leishmaniasis (VL) on the Indian subcontinent. The mechanisms operating in laboratory-generated strains are somewhat known, but the determinants of clinical antimony resistance are not well understood. By utilizing a DNA microarray expression profiling approach, we identified a gene encoding mitogen-activated protein kinase 1 (MAPK1) for the kinetoplast protozoan Leishmania donovani (LdMAPK1) that was consistently downregulated in antimony-resistant field isolates. The expression level of the gene was validated by real-time PCR. Furthermore, decreased expression of LdMAPK1 was also confirmed at the protein level in resistant isolates. Primary structure analysis of LdMAPK1 revealed the presence of all of the characteristic features of MAPK1. When expressed in Escherichia coli, the recombinant enzyme showed kinase activity with myelin basic protein as the substrate and was inhibited by staurosporine. Interestingly, overexpression of this gene in a drug-sensitive laboratory strain and a resistant field isolate resulted in increased the sensitivity of the transfectants to potassium antimony tartrate, suggesting that it has a role in antimony resistance. Our results demonstrate that downregulation of LdMAPK1 may be in part correlated with antimony drug resistance in Indian VL isolates.

Ashutosh; Garg, Mansi; Sundar, Shyam; Duncan, Robert; Nakhasi, Hira L.

2012-01-01

130

Isolation of RNA from field-grown jute (Corchorus capsularis) plant in different developmental stages for effective downstream molecular analysis.  

PubMed

Jute (Corchorus capsularis), as a natural fibre producing plant species, ranks next to cotton only. Today, biotechnological approach has been considered as most accepted means for any genetic improvement of plant species. However, genetic control of the fibre development in jute has not yet been explored sufficiently for desired genetic improvement. One of the major impediments in exploring the genetic architecture in this crop at molecular level is the availability of good quality RNA from field-grown plant tissues mostly due to the presence of high amount of mucilage and phenolics. Development of a suitable RNA isolation method is becoming essential for deciphering developmental stage-specific gene expression pattern related to fibre formation in this crop species. A combination of modified hot borate buffer followed by isopycnic centrifugation (termed as HBIC) was adopted and found to be the best isolation method yielding sufficient quantity (~350-500 ?g/gm fresh tissue) and good quality (A(260/280) ratio 1.88 to 1.91) RNA depending on the developmental stage of stem tissue from field-grown jute plant. The poly A(+) RNA purified from total RNA isolated by the present method was found amenable to efficient RT-PCR and cDNA library construction. The present development of RNA isolation was found to be appropriate for gene expression analysis related to fibre formation in this economically important jute plant in near future. PMID:21327574

Samanta, Pradipta; Sadhukhan, Sanjoy; Das, Subrata; Joshi, Alpana; Sen, Soumitra K; Basu, Asitava

2011-10-01

131

[Synchronization of electrical field potentials in neocortex of rat after isolation of a cortex island in the contralateral brain hemisphere].  

PubMed

A correlation between the number of boutons and synchronization of electrical activity in two sites of the intact right somatosensory cortex of rats was anakyzed at different stages of axonal sprouting elicited by isolation of a cortex slab in the left cortex. Time delay between the development of epileptiform field potentials in two sites of intact cortex located at a distance of 4 mm from each other was determined as a parameter of synchronization. The analysis was carried out in 30 and 90 days after the complete isolation of the neural island in a symmetrical site of the contralateral cortex. Epileptiform activity was induced by penicillin. A significant increase in the number of boutons in the II and V layers of the intact cortex observed 90 days after the isolation of neural island in a symmetrical site of the cortex corresponded to a significant decrease in the delay of electrical activity development. Similar effects were observed in the V layer of the island 30 days after the isolation. The results suggest that the cortex lesion activates formation of new synaptic boutons in a contralateral site and increases a degree of synchronization of electrical activity, which may affect the epileptogenesis. The data suggest that pyramids of the III and, most probably, V layers form a neuronal network in the rat neocortex thus providing synchronization of epileptiform field potentials. PMID:18666572

Marchenko, V G; Pasikova, N V

2008-01-01

132

Existence of variant strains Fowlpox virus integrated with Reticuloendotheliosis virus in its genome in field isolates in Tanzania.  

PubMed

Fowlpox virus (FPV) is one example of poultry viruses which undergoes recombination with Reticuloendotheliosis virus (REV). Trepidation had been raised, and it was well established on augmented pathogenicity of the FPV upon integration of the full intact REV. In this study, we therefore intended at assessing the integration of REV into FPV genome of the field isolates obtained in samples collected from different regions of Tanzania. DNA extraction of 85 samples (scabs) was performed, and FPV-specific PCR was done by the amplification of the highly conserved P4b gene. Evaluation of FPV-REV recombination was done to FPV-specific PCR positively identified samples by amplifying the env gene and REV long terminal repeats (5' LTR). A 578-bp PCR product was amplified from 43 samples. We are reporting for the first time in Tanzania the existence of variant stains of FPV integrated with REV in its genome as 65 % of FPV identified isolates were having full intact REV integration, 21 % had partial FPV-REV env gene integration and 5 % had partial 5' LTR integration. Despite of the fact that FPV-REV integrated stains prevailed, FPV-REV-free isolates (9 %) also existed. In view of the fact that full intact REV integration is connected with increased pathogenicity of FPV, its existence in the FPV genome of most field isolates could have played a role in increased endemic, sporadic and recurring outbreaks in selected areas in Tanzania. PMID:24557589

Mzula, Alexanda; Masola, Selemani N; Kasanga, Christopher J; Wambura, Philemon N

2014-06-01

133

Enzyme Mini-Test for Field Identification of Leishmania isolates from U.S. Military Personnel.  

National Technical Information Service (NTIS)

Certain WRAIR isolates have been characterized for up to 29 enzymes by cellulose acetate electrophoresis (CAE) and were identified as follows: 6 as Leishmania braziliensis braziliensis; 31 as L. b. panamensis,; 3 as L. chagasi; 3 as L. mexicana mexicana; ...

R. D. Kreutzer

1983-01-01

134

Breakdown Characteristics of an Isolated Conducting Object in a Uniform Electric Field.  

National Technical Information Service (NTIS)

A laboratory experiment was conducted to determine the physical processes involved in the electrical breakdown of a particular spark gap arrangement. The gap consists of an isolated conducting ellipsoid located midway between two large flat electrodes. Gr...

M. G. Grothaus T. F. Trost

1986-01-01

135

Draft Genome Sequence of the Field Isolate Brucella melitensis Strain Bm IND1 from India  

PubMed Central

Brucella spp. are facultative intracellular bacterial pathogens causing the zoonotic disease brucellosis. Here, we report the draft genome sequence of the Brucella melitensis strain from India designated Bm IND1, isolated from stomach contents of an aborted goat fetus.

Rao, Sashi Bhushan; Gupta, Vivek K.; Kumar, Mukesh; Hegde, Nagendra R.; Splitter, Gary A.; Reddanna, Pallu

2014-01-01

136

Comparison of in vitro activity of danofloxacin, florfenicol, oxytetracycline, spectinomycin and tilmicosin against recent field isolates of Mycoplasma bovis.  

PubMed

The minimum inhibitory concentrations (MICS) and minimum mycoplasmacidal concentrations (MMCs) of danofloxacin, florfenicol, oxytetracycline, spectinomycin and tilmicosin against 62 recent British field isolates of Mycoplasma bovis were determined in vitro by a broth microdilution method. The isolates were most susceptible todanofloxacin with MIC90 and MMC90 values of 0.5 microg/ml and 1.0 microg/ml, respectively. They were less susceptible to florfenicol with a MIC90 of 16 microg/ml and MMC90 of 32 microg/ml. Oxytetracycline and spectinomycin had only a limited effect against the majority of isolates tested with MIC50s of 32 microg/ml and 4 microg/ml, respectively and MIC90s of 64 microg/ml and more than 128 microg/ml, respectively. Nearly 20 per cent of the isolates were highly resistant to spectinomycin, and tilmicosin was ineffective, with 92 per cent of the isolates having MIC values of 128 microg/ml or greater. There was no evidence of resistance by M bovis to danofloxacin. PMID:10909906

Ayling, R D; Baker, S E; Peek, M L; Simon, A J; Nicholas, R A

2000-06-24

137

Genetic Analysis of Fenhexamid-Resistant Field Isolates of the Phytopathogenic Fungus Botrytis cinerea  

Microsoft Academic Search

The hydroxyanilide fenhexamid, one of the latest antibotrytis fungicides, active especially against leotiomy- cete plant-pathogenic fungi, inhibits 3-ketoreductase of the C-4-demethylation enzyme complex during ergos- terol biosynthesis. We isolated Botrytis cinerea strains resistant to various levels of fenhexamid from French and German vineyards. The sequence of the gene encoding 3-ketoreductase, erg27, varied according to levels of resistance. Highly resistant isolates,

Sabine Fillinger; Pierre Leroux; Christiane Auclair; Christian Barreau; Charbel Al Hajj; Daniele Debieu

2008-01-01

138

Human cytomegalovirus UL131A, UL130 and UL128 genes are highly conserved among field isolates  

Microsoft Academic Search

Summary.  Coding sequences of the UL131A, UL130, and UL128 genes of human cytomegalovirus (HCMV) were found to be highly conserved among\\u000a 34 field isolates from pregnant women with primary HCMV infection and their fetuses or newborns, as well as from solid organ\\u000a transplant recipients and patients with AIDS. No strain clustering was observed. In contrast, sequencing of UL55 (gB coding\\u000a gene)

F. Baldanti; S. Paolucci; G. Campanini; A. Sarasini; E. Percivalle; M. G. Revello; G. Gerna

2006-01-01

139

Intracellular calcium activity in isolated bovine adrenal chromaffin cells in the presence and absence of 60 Hz magnetic fields  

Microsoft Academic Search

This study examined whether 60 Hz magnetic field (MF) exposure alters intracellular calcium levels ((Ca2þ)i) in isolated bovine adrenal chromaffin cells, a classic model of neural responses. (Ca 2þ )i was monitored by fluorescence video imaging of cells loaded with the calcium indicator fluo-4 during exposures to magnetic flux densities of 0.01, 0.1, 1.0, 1.4, or 2.0 mT. MFs generated

Gale L. Craviso; James Poss; Christine Lanctot; Steven S. Lundback; Indira Chatterjee; Nelson G. Publicover

2002-01-01

140

Molecular Typing of Selected Enterococcus faecalis Isolates: Pilot Study Using Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

The present study compared the recently developed multilocus sequence typing (MLST) approach with a well-established molecular typing technique, pulsed-field gel electrophoresis (PFGE), for subspecies differen- tiation of Enterococcus faecalis isolates. We sequenced intragenic regions of three E. faecalis antigen-encoding genes (ace, encoding a collagen and laminin adhesin; efaA, encoding an endocarditis antigen; and salA, encoding a cell wall associated antigen)

Sreedhar R. Nallapareddy; Ruay-Wang Duh; Kavindra V. Singh; Barbara E. Murray

2002-01-01

141

Aquaporin 2 mutations in Trypanosoma brucei gambiense field isolates correlate with decreased susceptibility to pentamidine and melarsoprol.  

PubMed

The predominant mechanism of drug resistance in African trypanosomes is decreased drug uptake due to loss-of-function mutations in the genes for the transporters that mediate drug import. The role of transporters as determinants of drug susceptibility is well documented from laboratory-selected Trypanosoma brucei mutants. But clinical isolates, especially of T. b. gambiense, are less amenable to experimental investigation since they do not readily grow in culture without prior adaptation. Here we analyze a selected panel of 16 T. brucei ssp. field isolates that (i) have been adapted to axenic in vitro cultivation and (ii) mostly stem from treatment-refractory cases. For each isolate, we quantify the sensitivity to melarsoprol, pentamidine, and diminazene, and sequence the genomic loci of the transporter genes TbAT1 and TbAQP2. The former encodes the well-characterized aminopurine permease P2 which transports several trypanocides including melarsoprol, pentamidine, and diminazene. We find that diminazene-resistant field isolates of T. b. brucei and T. b. rhodesiense carry the same set of point mutations in TbAT1 that was previously described from lab mutants. Aquaglyceroporin 2 has only recently been identified as a second transporter involved in melarsoprol/pentamidine cross-resistance. Here we describe two different kinds of TbAQP2 mutations found in T. b. gambiense field isolates: simple loss of TbAQP2, or loss of wild-type TbAQP2 allele combined with the formation of a novel type of TbAQP2/3 chimera. The identified mutant T. b. gambiense are 40- to 50-fold less sensitive to pentamidine and 3- to 5-times less sensitive to melarsoprol than the reference isolates. We thus demonstrate for the first time that rearrangements of the TbAQP2/TbAQP3 locus accompanied by TbAQP2 gene loss also occur in the field, and that the T. b. gambiense carrying such mutations correlate with a significantly reduced susceptibility to pentamidine and melarsoprol. PMID:24130910

Graf, Fabrice E; Ludin, Philipp; Wenzler, Tanja; Kaiser, Marcel; Brun, Reto; Pyana, Patient Pati; Büscher, Philippe; de Koning, Harry P; Horn, David; Mäser, Pascal

2013-01-01

142

Genetic polymorphism of merozoite surface protein-1 and merozoite surface protein-2 in Plasmodium falciparum field isolates from Myanmar  

PubMed Central

Background Merozoite surface protein-1 (MSP-1) and MSP-2 of Plasmodium falciparum are potential vaccine candidate antigens for malaria vaccine development. However, extensive genetic polymorphism of the antigens in field isolates of P. falciparum represents a major obstacle for the development of an effective vaccine. In this study, genetic polymorphism of MSP-1 and MSP-2 among P. falciparum field isolates from Myanmar was analysed. Methods A total of 63 P. falciparum infected blood samples, which were collected from patients attending a regional hospital in Mandalay Division, Myanmar, were used in this study. The regions flanking the highly polymorphic characters, block 2 for MSP-1 and block 3 for MSP-2, were genotyped by allele-specific nested-PCR to analyse the population diversity of the parasite. Sequence analysis of the polymorphic regions of MSP-1 and MSP-2 was also conducted to identify allelic diversity in the parasite population. Results Diverse allelic polymorphism of MSP-1 and MSP-2 was identified in P. falciparum isolates from Myanmar and most of the infections were determined to be mixed infections. Sequence analysis of MSP-1 block 2 revealed that 14 different alleles for MSP-1 (5 for K1 type and 9 for MAD20 type) were identified. For MSP-2 block 3, a total of 22 alleles (7 for FC27 type and 15 for 3D7 type) were identified. Conclusion Extensive genetic polymorphism with diverse allele types was identified in MSP-1 and MSP-2 in P. falciparum field isolates from Myanmar. A high level of mixed infections was also observed, as was a high degree of multiplicity of infection.

2010-01-01

143

Characterization of CbCyp51 from field isolates of Cercospora beticola.  

PubMed

The hemibiotrophic fungus Cercospora beticola causes leaf spot of sugar beet. Leaf spot control measures include the application of sterol demethylation inhibitor (DMI) fungicides. However, reduced sensitivity to DMIs has been reported recently in the Red River Valley sugar beet-growing region of North Dakota and Minnesota. Here, we report the cloning and molecular characterization of CbCyp51, which encodes the DMI target enzyme sterol P450 14?-demethylase in C. beticola. CbCyp51 is a 1,632-bp intron-free gene with obvious homology to other fungal Cyp51 genes and is present as a single copy in the C. beticola genome. Five nucleotide haplotypes were identified which encoded three amino acid sequences. Protein variant 1 composed 79% of the sequenced isolates, followed by protein variant 2 that composed 18% of the sequences and a single isolate representative of protein variant 3. Because resistance to DMIs can be related to polymorphism in promoter or coding sequences, sequence diversity was assessed by sequencing >2,440 nucleotides encompassing CbCyp51 coding and flanking regions from isolates with varying EC(50) values (effective concentration to reduce growth by 50%) to DMI fungicides. However, no mutations or haplotypes were associated with DMI resistance or sensitivity. No evidence for alternative splicing or differential methylation of CbCyp51 was found that might explain reduced sensitivity to DMIs. However, CbCyp51 was overexpressed in isolates with high EC(50) values compared with isolates with low EC(50) values. After exposure to tetraconazole, isolates with high EC(50) values responded with further induction of CbCyp51, with a positive correlation of CbCyp51 expression and tetraconazole concentration up to 2.5 ?g ml(-1). PMID:22085297

Bolton, Melvin D; Birla, Keshav; Rivera-Varas, Viviana; Rudolph, Kurt D; Secor, Gary A

2012-03-01

144

Overexpression of Ubiquitin and Amino Acid Permease Genes in Association with Antimony Resistance in Leishmania tropica Field Isolates  

PubMed Central

The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime®) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

Kazemi-Rad, Elham; Khadem-Erfan, Mohammad Bagher; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Saffari, Mojtaba; Raoofian, Reza

2013-01-01

145

Species diversity and toxigenic potential of Fusarium graminearum complex isolates from maize fields in northwest Argentina  

Microsoft Academic Search

Members of the Fusarium graminearum species complex (Fg complex) are the causal agents of ear rot in maize and Fusarium head blight of wheat and other small grain cereals. The potential of these pathogens to contaminate cereals with trichothecene mycotoxins is a health risk for both humans and animals. A survey of ear rot isolates from maize collected in northwest

D. A. Sampietro; C. G. Díaz; V. Gonzalez; M. A. Vattuone; L. D. Ploper; C. A. N. Catalan; T. J. Ward

2011-01-01

146

Draft Genome Sequence of the Field Isolate Brucella melitensis Strain Bm IND1 from India.  

PubMed

Brucella spp. are facultative intracellular bacterial pathogens causing the zoonotic disease brucellosis. Here, we report the draft genome sequence of the Brucella melitensis strain from India designated Bm IND1, isolated from stomach contents of an aborted goat fetus. PMID:24874680

Rao, Sashi Bhushan; Gupta, Vivek K; Kumar, Mukesh; Hegde, Nagendra R; Splitter, Gary A; Reddanna, Pallu; Radhakrishnan, Girish K

2014-01-01

147

Isolation and identification of atrazine-degrading bacteria from corn field soil in Fars province of Iran.  

PubMed

In this study several agricultural fields with a long history of atrazine application in Fars province of Iran have been explored for their potential of atrazine biodegradation. After several subculturing for a period of 300 days acclimation, leads to an enhancement of atrazine biodegradation rate. A successful enrichment culture with a high capability for atrazine degradation was obtained (88%). A combination of enrichment culture technique, in a basal salt medium containing atrazine and carbon sources under nitrogen limitation and plating on indicator atrazine agar, have permitted the isolation of bacterial consortium with high capability of using atrazine as a nitrogen source. Seven gram-negative and one gram-positive bacterial strain, which were able to use this herbicide as a sole source of nitrogen, were isolated from Darehasalouie Kavar corn field soil. Based on physiological, biochemical and nutritional characteristics, the isolated bacteria were identified as Pseudomonas alcaligenes, Acidovorax sp., Pseudomonas putida, Ralstonia eutrophus, Pseudomonas syiringe, Erwinia tracheiphila, Entrobacter agglomerans and Micrococcus varians. Therefore, the bacterial consortium in liquid culture containing carbon sources and atrazine as a sole source of nitrogen, degrade added atrazine more than 80%. PMID:19069990

Dehghani, M; Nasseri, S; Amin, S; Naddafee, K; Taghavi, M; Yunesian, M; Maleky, N

2007-01-01

148

MAGNETIC FIELD IN THE ISOLATED MASSIVE DENSE CLUMP IRAS 20126+4104  

SciTech Connect

We measured polarized dust emission at 350 {mu}m toward the high-mass star-forming massive dense clump IRAS 20126+4104 using the SHARC II Polarimeter, SHARP, at the Caltech Submillimeter Observatory. Most of the observed magnetic field vectors agree well with magnetic field vectors obtained from a numerical simulation for the case when the global magnetic field lines are inclined with respect to the rotation axis of the dense clump. The results of the numerical simulation show that rotation plays an important role on the evolution of the massive dense clump and its magnetic field. The direction of the cold CO 1-0 bipolar outflow is parallel to the observed magnetic field within the dense clump as well as the global magnetic field, as inferred from optical polarimetry data, indicating that the magnetic field also plays a critical role in an early stage of massive star formation. The large-scale Keplerian disk of the massive (proto)star rotates in an almost opposite sense to the clump's envelope. The observed magnetic field morphology and the counterrotating feature of the massive dense clump system provide hints to constrain the role of magnetic fields in the process of high-mass star formation.

Shinnaga, Hiroko; Phillips, Thomas G. [California Institute of Technology Submillimeter Observatory, 111 Nowelo Street, Hilo, HI 96720 (United States); Novak, Giles [Department of Physics and Astronomy, Northwestern University, 633 Clark Street Evanston, IL 60208 (United States); Vaillancourt, John E. [Stratospheric Observatory for Infrared Astronomy, Universities Space Research Association, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Machida, Masahiro N. [Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Kataoka, Akimasa [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tomisaka, Kohji [National Astronomical Observatory of Japan and Department of Astronomy, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan); Davidson, Jacqueline; Houde, Martin [School of Physics, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Perth (Australia); Dowell, C. Darren [Jet Propulsion Laboratory, California Institute of Technology, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Leeuw, Lerothodi [SETI Institute, 515 North Whisman Avenue, Mountain View, CA 94043 (United States)

2012-05-10

149

Efficacy of commercial canarypox vaccine for protecting Hawai'i 'Amakihi from field isolates of Avipoxvirus  

USGS Publications Warehouse

At least three variants of avian pox virus are present in Hawai‘i - Fowlpox from domestic poultry and a group of genetically distinct viruses that cluster within two clades (Pox Variant 1 and Pox Variant 2) that are most similar to Canarypox based on DNA sequence of the virus 4b core protein gene. We tested whether Hawai‘i ‘Amakihi can be protected from wild virus isolates with an attenuated live Canarypox vaccine that is closely related to isolates that cluster within clade 1 (Pox Variant 1) based on sequence of the attenuated Canarypox virus 4b core protein. Thirty-one (31) Hawai`i ‘Amakihi (Hemignathus virens) with no prior physical evidence of pox infection were collected on Mauna Kea from xeric, high elevation habitats with low pox prevalence and randomly divided into two groups. One group of 16 was vaccinated with Poximmune C® while the other group received a sham vaccination with virus diluent. Four of 15 (27%) vaccinated birds developed potentially life-threatening disseminated lesions or lesions of unusually long duration, while one bird never developed a vaccine-associated lesion or "take". After vaccine-associated lesions healed, vaccinated birds were randomly divided into three groups of five and challenged with either a wild isolate of Fowlpox, a Hawai`i `Amakihi isolate of a Canarypox-like virus from clade 1 (Pox Variant 1) or a Hawai`i `Amakihi isolate of a Canarypox-like virus from clade 2 (Pox Variant 2). Similarly, three random groups of five unvaccinated ‘Amakihi were challenged with the same virus isolates. Vaccinated and unvaccinated ‘Amakihi challenged with Fowlpox had transient infections with no clinical signs of infection. Mortality in vaccinated ‘Amakihi that were challenged with Pox Variant 1 and Pox Variant 2 ranged from 0% (0/5) for Pox Variant 1 to 60% (3/5) for Pox Variant 2. Mortality in unvaccinated ‘Amakihi ranged from 40% (2/5) for Pox Variant 1 to 100% (5/5) for Pox Variant 2. While the vaccine provided some protection against Pox Variant 1, serious side effects and low efficacy against Pox Variant 2 make it risky to use in captive or wild honeycreepers.

Atkinson, Carter T.; Wiegand, Kimberly C.; Triglia, Dennis; Jarvi, Susan I.

2010-01-01

150

Effective Field Method in the Problem of Electromagnetic Wave Propagation Through a Medium With Isolated Inclusions  

Microsoft Academic Search

Effective field method is applied for the calculation of the phase velocities and attenuation factors of plane monochromatic electromagnetic waves in a dielectric medium with an array of spherical inclusions. The results of calculation are investigated in a wide region of the volume concentrations of inclusions and frequencies of the exciting field. The influence of the space distribution of the

S. K. Kanaun; D. Jeulin

1997-01-01

151

Complete Genome Sequence of K14JB01, a Novel Variant Strain of Porcine Epidemic Diarrhea Virus in South Korea  

PubMed Central

A novel variant strain of porcine epidemic diarrhea virus (PEDV) emerged on pig farms in South Korea during late 2013. Genomic DNA isolated from a K14JB01 strain identified in a diarrheal pig showed high sequence similarity to PEDV strains prevailing in the United States in 2013. This is the first study to identify the complete genome sequence of a novel variant PEDV in South Korea.

Cho, Yoon-Young; Lim, Seong-In; Kim, Yong Kwan; Song, Jae-Young; Lee, Joong-Bok

2014-01-01

152

Molecular analysis of Leptospira spp. isolated from humans by restriction fragment length polymorphism, real-time PCR and pulsed-field gel electrophoresis.  

PubMed

A total of 17 Leptospira clinical strains isolated from humans in Croatia were serologically and genetically analysed. For serovar identification, the microscopic agglutination test (MAT) and pulsed-field gel electrophoresis (PFGE) were used. To identify isolates on genomic species level, PCR-based restriction fragment length polymorphism (RFLP) and real-time PCR were performed. MAT revealed the following serogroup affinities: Grippotyphosa (seven isolates), Icterohaemorrhagiae (eight isolates) and Javanica (two isolates). RFLP of PCR products from a 331-bp-long fragment of rrs (16S rRNA gene) digested with endonucleases MnlI and DdeI and real-time PCR revealed three Leptospira genomic species. Grippotyphosa isolates belonged to Leptospira kirschneri, Icterohaemorrhagiae isolates to Leptospira interrogans and Javanica isolates to Leptospira borgpetersenii. Genomic DNA from 17 leptospiral isolates was digested with NotI and SgrAI restriction enzymes and analysed by PFGE. Results showed that seven isolates have the same binding pattern to serovar Grippotyphosa, eight isolates to serovar Icterohaemorrhagiae and two isolates to serovar Poi. Results demonstrate the diversity of leptospires circulating in Croatia. We point out the usefulness of a combination of PFGE, RFLP and real-time PCR as appropriate molecular methods in molecular analysis of leptospires. PMID:19780841

Turk, Nenad; Milas, Zoran; Mojcec, Vesna; Ruzic-Sabljic, Eva; Staresina, Vilim; Stritof, Zrinka; Habus, Josipa; Postic, Daniele

2009-11-01

153

Kenyan Plasmodium falciparum Field Isolates: Correlation between Pyrimethamine and Chlorcycloguanil Activity In Vitro and Point Mutations in the Dihydrofolate Reductase Domain  

Microsoft Academic Search

Sixty-nine Kenyan Plasmodium falciparum field isolates were tested in vitro against pyrimethamine (PM), chlorcycloguanil (CCG), sulfadoxine (SD), and dapsone (DDS), and their dihydrofolate reductase (DHFR) genotypes were determined. The in vitro data show that CCG is more potent than PM and that DDS is more potent than SD. DHFR genotype is correlated with PM and CCG drug response. Isolates can

A. NZILA-MOUNDA; E. K. MBERU; C. H. SIBLEY; C. V. PLOWE; P. A. WINSTANLEY; W. M. WATKINS

1998-01-01

154

Comparison and genomic sizing of Escherichia coli O157:H7 isolates by pulsed-field gel electrophoresis.  

PubMed Central

Genomic DNAs of Escherichia coli O157:H7 strains isolated from patients and food samples were analyzed by pulsed-field gel electrophoresis. The rare-cutting endonucleases SfiI and XbaI generated 6 and 10 distinct genomic profiles, respectively, for the 22 strains analyzed, indicating that this technique may find application for epidemiologic studies. Summation of XbaI fragments from five E. coli O157:H7 strains estimated the genomic length at ca. 4.7 Mb. Images

Harsono, K D; Kaspar, C W; Luchansky, J B

1993-01-01

155

Isolated High-Purity Platinum Nanowire Growth via Field Emission from a Multi-Walled Carbon Nanotube  

NASA Astrophysics Data System (ADS)

Isolated high-purity platinum nanowire growth was presented via field emission from the tip of a multi-walled carbon nanotube (MWCNT) with a precursor of cyclopentadienyl-trimethyl-platinum(IV) (CpPtMe3) inside a scanning electron microscope (SEM). A nanomanipulation system was used to adjust the gap between the anode (tungsten probe) and cathode (MWCNT) in order to control the nanowire growth length which achieved a platinum nanowire length of 1.18 ?m. The chemical composition of the platinum nanowire analyzed by energy-dispersive X-ray spectroscopy (EDS) shows that the purity of the platinum in the nanowire reaches 94.9 wt %.

Yang, Zhan; Nakajima, Masahiro; Saito, Yahachi; Ode, Yasuhito; Fukuda, Toshio

2011-03-01

156

Human isolated ileum: motor responses of the circular muscle to electrical field stimulation and exogenous neuropeptides  

Microsoft Academic Search

(1) Circularly-oriented muscle strips from the human ileum responded to electrical field stimulation (1–50 Hz) with frequency-related primary relaxation at low frequency and primary contractions at high frequencies of stimulation. Both responses were abolished or markedly reduced by tetrodotoxin (1 µM). (2) Atropine (3 µ M) or omega conotoxin (0.1 µM) reduced but dit not abolish contraction to electrical field

Carlo Alberto Maggi; Riccardo Patacchini; Paolo Santicioli; Sandro Giuliani; Damiano Turini; Gabriele Barbanti; Antonio Giachetti; Alberto Meli

1990-01-01

157

Genome Sequences of Porcine Epidemic Diarrhea Virus: In Vivo and In Vitro Phenotypes  

PubMed Central

Since the outbreak of porcine epidemic diarrhea virus (PEDV) in May 2013, U.S. swine producers have lost almost five million baby pigs. In an attempt to understand the evolution of PEDV in the United States and possibly develop a control strategy, we compared the genome sequences of a PEDV strain isolated from an infected piglet against its in vitro adapted version. The original PEDV strain was grown in Vero cells and passed 10 times serially in a MARC145 cell line. The sequence analysis of the native PEDV strain and in vitro passaged virus shows that the cell culture adaptation specifically modifies PEDV spike protein whereas the open reading frame 1a/b (ORF1a/b)-encoded polyprotein, the nucleoprotein, NS3B (ORF3), and membrane and envelope proteins remain unchanged.

Bumgardner, Eric; Bey, Russell F.; Stine, Douglas; Bumgarner, Roger E.

2014-01-01

158

[Isolation of a field strain of Babesia bigemina (Piroplasma: Babesiidae) and establishment of in vitro culture for antigen production].  

PubMed

Isolation of a field strain of Babesia bigemina (Piroplasma: Babesiidae) and establishment of in vitro culture for antigen production. Bovine b abesiosis, caused by Babesia bigemina, is a barrier for livestock development; it results in high economic loss to Mexican livestock. Control requires adequate antigens for diagnosis and vaccination programs. However, because of antigenic variation among Babesia strains, it is necessary to use antigens prepared from local strains. The purpose of the present study was to isolate a local field strain and to establish the in vitro culture of B. bigemina by the evaluation of the constituent's concentration of culture media. Thirty engorged female Boophilus microplus were collected from cattle suffering clinical babesiosis (B. bigemina) in Yucatan state, Mexico. These ticks were sent to the laboratory for detection of Babesia sp. vermicules. Eggs were kept at 83-85 % humidity and 27 degrees C until hatching. Larvae were transferred to an esplenectomized calf (B-1). The resulting nymphs were transferred to an esplenectomized calf (B-2). Twelve days later, B. bigemina (local strain) was detected in calf B-2 and its infected blood was frozen in liquid nitrogen to initiate the in vitro culture. The Microaerophilus Stationary Phase (MASP) in vitro culture method was used to reactivate the parasite. Three different concentrations of culture media (70, 60 and 50%), serum (30, 40 and 50%) and uninfected red blood cells (5, 10 and 15 %) were used in order to know the convenient concentrations to obtain the highest percentage of infected red blood cells (PEI). The cultured strain was used to prepare antigens for the Immunofluorescence Antibody Test (IFAT) and several concentrations of serum and conjugate were tested. Strain isolation was successful; 30 days were needed to obtain a PEI of 1.5%. The isolated strain was frozen in liquid nitrogen and the parasites were reactivated with the in vitro culture MASP method. The concentration of culture media that produced the highest PEI (14%) (p < 0.05) was 30% serum, 70% M199 and 5%. Uninfected Red Blood cells antigens were successfully used in the IFAT and the best dilutions to differentiate between positive and negative controls were serum 1:80 and conjugate 1:80. The isolated B. bigemina local strain requires particular conditions of in vitro culture by the MASP method to reach high numbers of infected red blood cells, needed to prepare and provide high quality antigens for serological diagnosis of B. bigemina. PMID:18457120

Rodríguez-Vivas, Roger I; Quiñones-Avila, Franklin J; Ramírez-Cruz, Genny T; Cruz, David; Wagner, Gale

2007-03-01

159

Comparison of Botrytis cinerea populations isolated from two open-field cultivated host plants.  

PubMed

The necrotrophic fungus Botrytis cinerea is reported to infect more than 220 host plants worldwide. In phylogenetical-taxonomical terms, the pathogen is considered a complex of two cryptic species, group I and group II. We sampled populations of B. cinerea on sympatric strawberry and raspberry cultivars in the North-East of Hungary for three years during flowering and the harvest period. Four hundred and ninety group II B. cinerea isolates were analyzed for the current study. Three different data sets were generated: (i) PCR-RFLP patterns of the ADP-ATP translocase and nitrate reductase genes, (ii) MSB1 minisatellite sequence data, and (iii) the fragment sizes of five microsatellite loci. The structures of the different populations were similar as indicated by Nei's gene diversity and haplotype diversity. The F statistics (Fst, Gst), and the gene flow indicated ongoing differentiation within sympatric populations. The population genetic parameters were influenced by polymorphisms within the three data sets as assessed using Bayesian algorithms. Data Mining analysis pointed towards the five microsatellite loci as the most defining markers to study differentiation in the 490 isolates. The results suggest the occurrence of host-specific, sympatric divergence of generalist phytoparasites in perennial hosts. PMID:23353014

Asadollahi, Mojtaba; Fekete, Erzsébet; Karaffa, Levente; Flipphi, Michel; Árnyasi, Mariann; Esmaeili, Mahdi; Váczy, Kálmán Zoltán; Sándor, Erzsébet

2013-07-19

160

Matrix isolation, zero-field splitting parameters, and photoreactions of septet 2,4,6-trinitrenopyrimidines.  

PubMed

The key intermediates of decomposition of high-energy 2,4,6-triazidopyrimidine and its 5-chloro-substituted derivative, the detonation of which is used for preparation of carbon nitrides, were investigated using electron paramagnetic resonance (EPR) spectroscopy in combination with quantum chemical calculations. The decomposition of the triazides was carried out photochemically, using the matrix isolation technique. The photodecomposition of both triazides with 254 nm light in argon matrices at 5 K occurred selectively to subsequently give the corresponding triplet 4,6-diazido-2-nitrenopyrimidines, quintet 4-azido-2,6-dinitrenopyrimidines, and septet 2,4,6-trinitrenopyrimidines. The latter were photochemically unstable and decomposed to form triplet nitrenes NCN and NNC as well as triplet carbenes NCCCN, HCCN, and HCCCCN. The results obtained provide important information about exchange interactions in high-spin nitrenes with the pyrimidine ring and the mechanism of the formation of carbon nitrides during thermolysis of 2,4,6-triazidopyrimidine. PMID:24905080

Chapyshev, Sergei V; Ushakov, Evgeny N; Neuhaus, Patrik; Sander, Wolfram

2014-07-01

161

Isolated-core excitations in strong electric fields. III. The Ba 6p{sub j}nk series  

SciTech Connect

The cross section for isolated-core excitation (ICE) of barium 6p{sub j}n{sup '}k{sup '} autoionizing states from 6snk Stark levels has been measured as a function of applied electric-field strength. For the most part, states that are well mixed by the applied field have nearly Lorentzian line shapes indicating predominant ICE of a single autoionizing resonance with n{sup '}=n and k{sup '}=k. Small non-Lorentzian shake-up features in the wings of the lines are examined in detail using high laser power to depletion broaden the main resonance and amplify the wings of the line shapes. While analogous shake-up features in zero-field ICE spectra are easily described theoretically, attempts to reproduce the spectra observed in a field generally fail to provide good agreement. Finally, significant differences in excitation of Ba{sup +} 6p{sub 1/2} rather than Ba{sup +} 6p{sub 3/2} cores are observed. (c) 2000 The American Physical Society.

Jones, R. R. [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)] [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States); Lyons, B. J. [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)] [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States); Baig, M. A. [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)] [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States); Djambova, Svetlana T. [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)] [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States); Gallagher, T. F. [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)] [Department of Physics, University of Virginia, Charlottesville, Virginia 22901 (United States)

2000-09-01

162

From Isolation to Collaboration: Rethinking the Preservice Field Experience from a Community Perspective  

ERIC Educational Resources Information Center

In this article, we report the action research that shaped the development of the Growing Career Educators project, a teacher-designed field experience for preservice teachers within a high school in the fifth-largest school district in the country. The research consisted of two cycles of action research, both of which focused on whether a…

Bower, Laura A.; Klecka, Cari L.; Silva, Susan

2010-01-01

163

Impact of porcine group A rotavirus co-infection on porcine epidemic diarrhea virus pathogenicity in piglets.  

PubMed

Porcine epidemic diarrhea virus (PEDV) and porcine group A rotavirus (PGAR) are the main causative agents of acute diarrhea in piglets. In South Korea, PGAR is prevalent in piglets naturally infected with PEDV. Piglets naturally co-infected with PEDV and PGAR appeared to have severe and prolonged diarrhea that was distinct from that commonly observed. The aim of this study was to determine the impact of PGAR co-infection on PEDV pathogenicity in piglets. Thirty-six colostrum-deprived, one-day old, Large White-Duroc crossbred pigs were randomly divided into four equal groups: PEDV, PEDV/PGAR, PGAR, and control groups. The piglets were euthanized at 1, 2, or 3 days post-inoculation (DPI) to measure the villous height:crypt depth (VH:CD) ratio and to collect fecal samples for RT-PCR and virus isolation. No significant differences in mean VH:CD ratio and clinical symptoms (diarrhea, vomiting, dehydration, and anorexia) were observed between the PEDV/PGAR-infected and PEDV-infected groups of piglets at 1, 2 and 3 DPI; however, at 2 and 3 DPI, PGAR was detected in all fecal samples by RT-PCR and virus isolation. These findings failed to detect any interaction between PEDV and porcine rotavirus in the small intestines of piglets, suggesting that concurrent infection of PGAR may not synergistically enhance intestinal villous atrophy of piglets with PEDV disease. We propose that the severe diarrhea exhibited in PEDV and PGAR co-infected piglets may be more associated with the immunity level of the host rather than to any synergistic effect of PGAR on PEDV enteritis. PMID:17727905

Jung, Kwonil; Kang, Bo-Kyu; Lee, Chul-Seung; Song, Dae-Sub

2008-06-01

164

An efficient thermotolerant and halophilic biosurfactant-producing bacterium isolated from Dagang oil field for MEOR application  

NASA Astrophysics Data System (ADS)

Dagang Oil field (Petro China Company Limited) is one of the most productive oil fields in China. In this study, 34 biosurfactant-producing strains were isolated and cultured from petroleum reservoir of Dagang oil field, using haemolytic assay and the qualitative oil-displacement test. On the basis of 16S rDNA analysis, the isolates were closely related to the species in genus Pseudomonas, Staphylococcus and Bacillus. One of the isolates identified as Bacillus subtilis BS2 were selected for further study. This bacterium was able to produce a type of biosurfactant with excessive foam-forming properties at 37ºC as well as at higher temperature of 55ºC. The biosurfactant produced by the strain BS2 could reduce the surface tension of the culture broth from 70.87 mN/m to 28.97 mN/m after 8 days of incubation at 37ºC and to 36.15 mN/m after 20 days of incubation at 55ºC, respectively. The biosurfactant showed stability at high temperature (up to 120ºC), a wide range of pH (2 to 12) and salt concentrations (up to 12%) offering potential for biotechnology. Fourier transform infrared (FT-IR) spectrum of extracted biosurfactant tentatively characterized the produced biosurfactant as glycolipid derivative. Elemental analysis of the biosurfactant by energy dispersive X-ray spectroscopy (EDS) reveals that the biosurfactant was anionic in nature. 15 days of biodegradation of crude oil suggested a preferential usage of n-alkane upon microbial metabolism of BS2 as a carbon substrate and consequently also for the synthesis of biosurfactants. Core flood studies for oil release indicated 9.6% of additional oil recovery over water flooding at 37ºC and 7.2% of additional oil recovery at 55 ºC. Strain BS2 was characterized as an efficient biosurfactant-producing, thermotolerant and halophillic bacterium and has the potential for application for microbial enhanced oil recovery (MEOR) through water flooding in China's oil fields even in situ as adapted to reservoir chemistry and temperature.

Wu, Langping; Richnow, Hans; Yao, Jun; Jain, Anil

2014-05-01

165

Dirac model of an isolated graphene antidot in a magnetic field  

NASA Astrophysics Data System (ADS)

We consider a single graphene antidot, modeled via a circularly symmetric mass term in the Dirac Hamiltonian, in the presence of an external magnetic field. We derive analytical expressions for the eigenstate spinors, and use these to formulate an eigenvalue condition for the system. We find that electron-hole symmetry is broken in the individual valleys, while the combined spectrum of both valleys retains this symmetry. In the limit of an infinite mass term, we arrive at approximate analytical expressions for the energies. We discuss the dependence of the energy spectrum and the eigenstate spinors on the mass term and the magnetic field, as well as on the angular momentum of the eigenstate. We show that the density of states exhibits a very rich structure if the antidot radius is of the order of the magnetic length. By simulating scanning tunneling microscopy measurements, we discuss the possibility of experimentally probing states localized around the antidot.

Pedersen, Jesper Goor; Pedersen, Thomas Garm

2012-01-01

166

Genetic Characterization of Atypical Enteropathogenic Escherichia coli Isolates from Ewes' Milk, Sheep Farm Environments, and Humans by Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis  

PubMed Central

A collection of 81 isolates of enteropathogenic Escherichia coli (EPEC) was obtained from samples of bulk tank sheep milk (62 isolates), ovine feces (4 isolates), sheep farm environment (water, 4 isolates; air, 1 isolate), and human stool samples (9 isolates). The strains were considered atypical EPEC organisms, carrying the eae gene without harboring the pEAF plasmid. Multilocus sequence typing (MLST) was carried out with seven housekeeping genes and 19 sequence types (ST) were detected, with none of them having been previously reported for atypical EPEC. The most frequent ST included 41 strains isolated from milk and human stool samples. Genetic typing by pulsed-field gel electrophoresis (PFGE) resulted in 57 patterns which grouped in 24 clusters. Comparison of strains isolated from the different samples showed phylogenetic relationships between milk and human isolates and also between milk and water isolates. The results obtained show a possible risk for humans due to the presence of atypical EPEC in ewes' milk and suggest a transmission route for this emerging pathogen through contaminated water.

Otero, Veronica; Rodriguez-Calleja, Jose-Maria; Otero, Andres; Garcia-Lopez, Maria-Luisa

2013-01-01

167

Genomic and Pathogenic Studies on a Glycoprotein E Variant Field Isolate of Bovine Herpesvirus 1  

Microsoft Academic Search

Glycoprotein E-negative (gE–) laboratory strains of bovine herpesvirus 1 (BHV-1) were recently introduced as novel marker vaccines, allowing serological discrimination between vaccinated and naturally infected animals on the basis of lack or presence of antibodies against gE epitopes. The applicability of this approach is based on the genetic stability of the gE. However, mutant field variants of BHV-1 with a

L. Egyed; C. Ros; S. Belák

2000-01-01

168

High-resolution melt PCR analysis for rapid identification of Chlamydia abortus live vaccine strain 1B among C. abortus strains and field isolates.  

PubMed

We describe a novel high-resolution melt assay that clearly differentiates Chlamydia abortus live vaccine strain 1B from field C. abortus strains and field wild-type isolates based on previously described single nucleotide polymorphisms. This modern genotyping technique is inexpensive, easy to use, and less time-consuming than PCR-RFLP. PMID:22652433

Vorimore, Fabien; Cavanna, Noémie; Vicari, Nadia; Magnino, Simone; Willems, Hermann; Rodolakis, Annie; Siarkou, Victoria I; Laroucau, Karine

2012-09-01

169

Molecular analysis of field strains of Mycoplasma capricolum subspecies capripneumoniae and Mycoplasma mycoides subspecies mycoides, small colony type isolated from goats in Tanzania  

Microsoft Academic Search

A molecular analysis of strains of Mycoplasma capricolum subsp. capripneumoniae (M. capripneumoniae) and Mycoplasma mycoides subsp. mycoides, small colony type (M. mycoides SC) isolated from goats was performed using the amplified fragment length polymorphism (AFLP) and pulsed-field gel electrophoresis (PFGE) fingerprinting techniques. Among the 11 field strains of M. capripneumoniae from Tanzanian goats, two AFLP patterns were demonstrated, with 10

L. J. M Kusiluka; B Ojeniyi; N. F Friis; B Kokotovic; P Ahrens

2001-01-01

170

Trichothecene genotypes and chemotypes in Fusarium graminearum complex strains isolated from maize fields of northwest Argentina.  

PubMed

Members of the Fusarium graminearum species complex (Fg complex) cause Gibberella ear rot in maize from northwest Argentina. The potential of these pathogens to contaminate maize grains with type B trichothecenes is a health risk for both humans and animals. We evaluated the reliability of multiplex PCR assays based on TRI3 and TRI12 genes, and single PCR assays based on TRI7 and TRI13 genes to infer trichothecene chemotypes of 112 strains of Fg complex collected from northwest Argentina, checking trichothecene production by chemical analysis. Single and multiplex PCR assays indicated that strains belonging to F. meridionale (87/112) had a NIV genotype. The remainder strains (25/112), which belonged to F. boothii, had a DON genotype (based on single PCR assays) or 15ADON genotype (based on multiplex PCR assays). No strains tested were incorrectly diagnosed with a DON/NIV genotype. Chemical analysis indicated that the F. meridionale strains were NIV producers only (44/87), major NIV producers with unexpected high DON/NIV ratios (36/87), or unexpected major DON producers with minor NIV production (7/87). Strains with atypical DON/NIV production seem to be new phenotypes under a putative NIV genotype, since PCR assays do not provide evidences of a new trichothecene genotype. DON production and absence of its acetylated forms were shown for strains of F. boothii. The inconsistencies between genetic and chemical data highlight the risk of inferring the trichothecenes potentially contaminating food and feedstuffs based only on PCR assays. This study confirms for the first time that strains of Fg complex from maize of northwest Argentina are DON and NIV producers. In addition, dominance of NIV producers in the Fg complex population isolated from maize is unprecedented in Argentina, and of significant concern to food safety and animal production. PMID:22119268

Sampietro, Diego A; Ficoseco, María E Aristimuño; Jimenez, Cristina M; Vattuone, Marta A; Catalán, Cesar A

2012-02-01

171

Characterization of humoral responses to soluble trimeric HIV gp140 from a clade A Ugandan field isolate  

PubMed Central

Trimeric soluble forms of HIV gp140 envelope glycoproteins represent one of the closest molecular structures compared to native spikes present on intact virus particles. Trimeric soluble gp140 have been generated by several groups and such molecules have been shown to induce antibodies with neutralizing activity against homologous and heterologous viruses. In the present study, we generated a recombinant trimeric soluble gp140, derived from a previously identified Ugandan A-clade HIV field isolate (gp14094UG018). Antibodies elicited in immunized rabbits show a broad binding pattern to HIV envelopes of different clades. An epitope mapping analysis reveals that, on average, the binding is mostly focused on the C1, C2, V3, V5 and C5 regions. Immune sera show neutralization activity to Tier 1 isolates of different clades, demonstrating cross clade neutralizing activity which needs to be further broadened by possible structural modifications of the clade A gp14094UG018. Our results provide a rationale for the design and evaluation of immunogens and the clade A gp14094UG018 shows promising characteristics for potential involvement in an effective HIV vaccine with broad activity.

2013-01-01

172

Differential identification of Chlamydophila abortus live vaccine strain 1B and C. abortus field isolates by PCR-RFLP.  

PubMed

Comparative genomic analysis of a wild-type strain of the ovine pathogen Chlamydophila abortus and its nitrosoguanidine-induced, temperature-sensitive and virulence-attenuated live vaccine derivative identified point mutations unique to the mutant (Burall et al. [1]). Here, we evaluate the capacity of some of these mutations to either create or eliminate restriction sites using the wild-type strain C. abortus S26/3 as a reference. Three of eight genomic sites with confirmed point mutations (CAB153, CAB636 and CAB648) were retained for analysis as each resulted in the loss of a restriction site in the genome sequence of the vaccine strain. PCR-restriction fragment length polymorphism analysis using restriction enzymes chosen to specifically target the three genomic sites was then applied to a large number of C. abortus field isolates and reference strains. Our results indicate that the three mutations are uniquely present in the vaccine strain, and as such provide easy-to-use markers for the differential identification of the vaccine strain and wild-type isolates. PMID:20600479

Laroucau, Karine; Vorimore, Fabien; Sachse, Konrad; Vretou, Evangelia; Siarkou, Victoria I; Willems, Hermann; Magnino, Simone; Rodolakis, Annie; Bavoil, Patrik M

2010-08-01

173

Methanothermobacter tenebrarum sp. nov., a hydrogenotrophic, thermophilic methanogen isolated from gas-associated formation water of a natural gas field.  

PubMed

A thermophilic and hydrogenotrophic methanogen, strain RMAS(T), was isolated from gas-associated formation water of a gas-producing well in a natural gas field in Japan. Strain RMAS(T) grew solely on H(2)/CO(2) but required Casamino acids, tryptone, yeast extract or vitamins for growth. Growth of strain RMAS(T) was stimulated by acetate. Cells were non-motile, straight rods (0.5×3.5-10.5 µm) and occurred singly or in pairs. Bundles of fimbriae occurred at both poles of cells and the cell wall was thick (approximately 21 nm, as revealed by ultrathin section electron microscopy). Strain RMAS(T) grew at 45-80 °C (optimum, 70 °C), at pH 5.8-8.7 (optimum, pH 6.9-7.7) and with 0.001-20 g NaCl l(-1) (optimum, 2.5 g NaCl l(-1)). Phylogenetic analysis revealed that Methanothermobacter thermautotrophicus ?H(T) was most closely related to the isolate (95.7?% 16S rRNA gene sequence similarity). On the basis of morphological, phenotypic and phylogenetic characteristics, it is clear that strain RMAS(T) represents a novel species of the genus Methanothermobacter, for which we propose the name Methanothermobacter tenebrarum sp. nov. The type strain is RMAS(T) (?=?DSM 23052(T)?=?JCM 16532(T)?=?NBRC 106236(T)). PMID:22561588

Nakamura, Kohei; Takahashi, Azumi; Mori, Chikahiro; Tamaki, Hideyuki; Mochimaru, Hanako; Nakamura, Kazunori; Takamizawa, Kazuhiro; Kamagata, Yoichi

2013-02-01

174

Biodegradation of diesel oil by an Arabian Sea sediment culture isolated from the vicinity of an oil field.  

PubMed

Laboratory scale batch studies were performed to test the diesel oil biodegradation ability of ES1 cultures isolated from Arabian Sea sediments obtained from the vicinity of an oil field. This culture could utilize diesel as the sole source of carbon and energy. Under aerobic conditions, 39% loss of diesel oil was observed over 8 days where 80% of the loss was due to aliphatic constituents. Under anoxic nitrate reducing conditions the rate and extent of degradation was significantly lower, i.e., 18% over 50 days. Salt acclimatized cultures could tolerate salinities up to 3.5% and demonstrated optimal performance at a salinity of 0.5%. The optimum N/P ratio for these cultures was found to be in the range of 2:1-5:1. Addition of two trace elemental substance formulations exhibited a significant inhibitory effect on culture growth. This culture has good potential for decontamination of oil-contaminated marine and subsurface environments. PMID:15288270

Mukherji, Suparna; Jagadevan, Sheeja; Mohapatra, Gita; Vijay, Avinash

2004-12-01

175

Diversity of Listeria monocytogenes isolates of human and food origin studied by serotyping, automated ribotyping and pulsed-field gel electrophoresis.  

PubMed

Automated ribotyping, pulsed-field gel electrophoresis (PFGE) and serotyping were evaluated for the epidemiological study of isolates of Listeria monocytogenes collected in Finland in 1997-1999 from human blood (n = 116) and the food industry (n = 72). The isolates divided into six serotypes, 23 EcoRI ribotypes, 54 AscI PFGE types, and 57 final subtypes if all results were combined. The discrimination index of ribotyping was lower (0.873) than that of PFGE (0.946). Two final subtypes dominated among human isolates, and identical subtypes were also found among food industry isolates. All PFGE types were serotype-specific, whereas two ribotypes included isolates of two serotypes. Isolates of serotype 3a, involved in an outbreak in Finland in 1999, matched one of these ribotypes, which also included some food industry isolates of serotype 1/2a. Ribotyping with EcoRI would not have been sufficient to define the outbreak in Finland caused by serotype 3a isolates. Although ribotyping is applicable as the first method in outbreak situations, human and food isolates with identical ribotypes should be investigated further by PFGE. PMID:15191386

Lukinmaa, S; Aarnisalo, K; Suihko, M-L; Siitonen, A

2004-06-01

176

Biosynthesis of compatible solutes in rhizobial strains isolated from Phaseolus vulgaris nodules in Tunisian fields  

PubMed Central

Background Associated with appropriate crop and soil management, inoculation of legumes with microbial biofertilizers can improve food legume yield and soil fertility and reduce pollution by inorganic fertilizers. Rhizospheric bacteria are subjected to osmotic stress imposed by drought and/or NaCl, two abiotic constraints frequently found in semi-arid lands. Osmostress response in bacteria involves the accumulation of small organic compounds called compatible solutes. Whereas most studies on rhizobial osmoadaptation have focussed on the model species Sinorhizobium meliloti, little is known on the osmoadaptive mechanisms used by native rhizobia, which are good sources of inoculants. In this work, we investigated the synthesis and accumulations of compatible solutes by four rhizobial strains isolated from root nodules of Phaseolus vulgaris in Tunisia, as well as by the reference strain Rhizobium tropici CIAT 899T. Results The most NaCl-tolerant strain was A. tumefaciens 10c2, followed (in decreasing order) by R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3, R. etli 12a3 and R. gallicum bv. phaseoli 8a3. 13C- and 1H-NMR analyses showed that all Rhizobium strains synthesized trehalose whereas A. tumefaciens 10c2 synthesized mannosucrose. Glutamate synthesis was also observed in R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3 and A. tumefaciens 10c2. When added as a carbon source, mannitol was also accumulated by all strains. Accumulation of trehalose in R. tropici CIAT 899 and of mannosucrose in A. tumefaciens 10c2 was osmoregulated, suggesting their involvement in osmotolerance. The phylogenetic analysis of the otsA gene, encoding the trehalose-6-phosphate synthase, suggested the existence of lateral transfer events. In vivo 13C labeling experiments together with genomic analysis led us to propose the uptake and conversion pathways of different carbon sources into trehalose. Collaterally, the ?-1,2-cyclic glucan from R. tropici CIAT 899 was co-extracted with the cytoplasmic compatible solutes and its chemical structure was determined. Conclusions The soil bacteria analyzed in this work accumulated mainly disaccharides in response to NaCl stress. We could not find a direct correlation between the trehalose content of the rhizobial strains and their osmotolerance, suggesting that additional osmoadaptive mechanism should be operating in the most NaCl-tolerant strain R. tropici CIAT 899.

2010-01-01

177

In vitro and in vivo translational efficiencies of the 5' untranslated region from eight genotype 2 bovine viral diarrhea virus field isolates.  

PubMed

We determined the in vitro and in vivo translational efficiency mediated by the internal ribosomal entry site (IRES) from eight BVDV2 field isolates varying in virulence using a bicistronic reporter vector in rabbit reticulocyte lysates (RRL), and in primate and bovine cell lines. Using a T7-promoter system, the high virulence isolates had greater translational efficiencies in bovine lymphocytes (BL-3 cells), than did the low virulence isolates. The low virulence isolates translated with greater efficiencies than the high virulence isolates in RRL, African green monkey kidney (CV-1) and bovine turbinate (BT) cells. Our results demonstrate that despite a high degree of sequence identity in the 5' untranslated region (UTR), subtle differences in the primary and secondary structures, as well as differences in cell lines, influence translational efficiencies. PMID:15629777

Topliff, Christina L; Chon, Seung K; Donis, Ruben O; Eskridge, Kent M; Kelling, Clayton L

2005-01-20

178

In Vitro Susceptibility of Field Isolates of Leishmania donovani to Miltefosine and Amphotericin B: Correlation with Sodium Antimony Gluconate Susceptibility and Implications for Treatment in Areas of Endemicity  

Microsoft Academic Search

Indian Leishmania donovani isolates (n 19) from regional zones representing various levels of antimony resistance displayed significantly (P < 0.01) correlated results with respect to in vitro susceptibility to the antileishmanial drugs sodium antimony gluconate, amphotericin B, and Miltefosine, raising the possibility of cross-resistance mechanisms operating in the field isolates. The results of gene expression analysis of LdMT and LdRos3

Dhiraj Kumar; Arpita Kulshrestha; Ruchi Singh; Poonam Salotra

2009-01-01

179

Isolation of a new flavivirus related to Cell fusing agent virus (CFAV) from field-collected flood-water Aedes mosquitoes sampled from a dambo in central Kenya  

Microsoft Academic Search

Summary.  ?Cell fusing agent virus (CFAV) is an RNA insect virus that was isolated from a line of Aedes aegypti mosquito cells and has been assigned to the family Flaviviridae, genus Flavivirus. We report here the first isolation of a CFA-like virus from field-collected mosquitoes. Mosquito larvae and pupae were sampled\\u000a from flooded dambos in Central Province, Kenya during the short

R. C. Sang; A. Gichogo; J. Gachoya; M. D. Dunster; V. Ofula; A. R. Hunt; M. B. Crabtree; B. R. Miller; L. M. Dunster

2003-01-01

180

Time-resolved pyrolysis field ionization mass spectrometry of humic material isolated from freshwater  

SciTech Connect

The thermal degradation of aquatic humics in combination with mass spectrometric analyses using field ionization (FI) as a soft ionization method is reported. Since FI mass spectra of the pyrolysis (Py) products consist almost exclusively of molecular ions and mass spectrometric fragmentation even of relatively polar substances is strongly reduced, the characterization of biomacromolecules is facilitated and the identification of direct, primary building blocks is achieved. Furthermore, the thermal behavior of characteristic classes of humic constituents is investigated by time/temperature-resolved FI mass spectrometry (MS) with the commercially available direct-probe introduction system. A general characterization of the Py products of humics and the ratios of volatilized matter and residual char are given. These methods permit insight into the thermal degradation processes of complex polymeric biomatter. In contrast to the humic acid (HA) investigated, for fulvic acid (FA) a larger amount of pyrolysates is formed, indicating less thermal stability. The Py mass spectra of the HA and FA show monomers and higher aggregated chemical species of furan, phenol, methoxyphenol, and dimethoxyphenol subunits. Chemical reactions such as alternating methylation and oxidation steps of FA lead to characteristically different results: in the Py mass spectrum of the methylated-oxidized FA the m/z values of benzenecarboxylic acids, methoxybenzene-carboxylic acids, and monobasic aliphatic acids show high intensities, whereas methyl esters of benzenecarboxylic acids and aliphatic dibasic acids dominate in the case of the mass spectrum of the oxidized-methylated FA. 32 references, 5 figures, 4 tables.

Schulten, H.R.; Abbt-Braun, G.; Frimmel, F.H.

1987-04-01

181

Comparison of the sequence of the gene encoding African swine fever virus attachment protein p12 from field virus isolates and viruses passaged in tissue culture.  

PubMed Central

Comparison of the amino acid sequence of the African swine fever virus attachment protein p12 from different field virus isolates, deduced from the nucleotide sequence of the gene, revealed a high degree of conservation. No mutations were found after adaptation to Vero cells, and a polypeptide with similar characteristics was present in an IBRS2-adapted virus. The sequence of the 5' flanking region was conserved among the isolates, whereas sequences downstream of the gene were highly variable in length and contained direct repeats in tandem that may account for the deletions found in different isolates. Protein p12 was synthesized in swine macrophages infected with all of the viruses tested.

Angulo, A; Vinuela, E; Alcami, A

1992-01-01

182

[Molecular epidemiological analysis of an outbreak of Campylobacter jejuni using restriction enzyme double-digestion technique for genotyping of isolates by pulsed-field gel electrophoresis].  

PubMed

In an outbreak of gastroenteritis in elementary school students and their families in Chiba Prefecture, Japan, Campylobacter jejuni was isolated from the stools of 14 patients who developed diarrheal illness after a one-day bus trip. C. jejuni was also isolated from the stools of 3 patients not going on the bus trip. Pulsed-field gel electrophoresis (PFGE) analysis was done on 17 isolates of C. jejuni to study genetic relationships among them. PFGE profiles of isolates treated with restriction enzymes Sma I, Ksp I and Kpn I were separated into 9, 10, and 10 types, but the relationship between PFGE profiles and epidemiological profiles was unclear. Dendrograms of PFGE of isolates double-digested with both Sma I and Ksp I were typed into D1, D2, D3 and D4, and profiles compared to profiles of serotyping and flagellin typing of isolates and epidemiological profiles to evaluate genetical and epidemiological relationships. Thirteen isolates of PFGE type D1 possessed serotype G and flagellin type Al and were isolated from patients going on the bus trip. Type D2 isolated from a student going on the bus trip and type D3 isolates from two students not going on the bus trip had serotype B and flagellin type A2. C. jejuni of PFGE type D4, serotype UT, and flagellin type A3 was also isolated from a student not going on the trip. Our results show that at least two outbreaks of C. jejuni occurred simultaneously in people related to the school. Restriction enzyme double-digestion PFGE was thus useful in the molecular epidemiological analysis of the C. jejuni outbreak. PMID:17176857

Yoda, Kiyoe; Yokoyama, Eiji; Uchimura, Masako

2006-11-01

183

Detection of a bacteriophage gene encoding a Mu-like portal protein in Haemophilus parasuis reference strains and field isolates by nested polymerase chain reaction.  

PubMed

A nested polymerase chain reaction (nPCR) assay was developed to determine the presence of a gene encoding a bacteriophage Mu-like portal protein, gp29, in 15 reference strains and 31 field isolates of Haemophilus parasuis. Specific primers, based on the gene's sequence, were utilized. A majority of the virulent reference strains and field isolates tested harbored the gene. The results suggest that the nPCR technique described in the current report could serve as a tool for epidemiological studies of H. parasuis. PMID:21908286

Zehr, Emilie S; Tabatabai, Louisa B

2011-05-01

184

Plasmid Profile and Pulsed-Field Gel Electrophoresis Analysis of Salmonella enterica Isolates from Humans in Turkey  

PubMed Central

This study was conducted for typing Salmonella enterica subspecies enterica strains in Turkey using pulsed–field gel electrophoresis (PFGE) and plasmid DNA profile analysis. Fourty-two strains were isolated from clinical samples obtained from unrelated patients with acute diarrhea. The samples were collected from state hospitals and public health laboratories located at seven provinces in different regions of Turkey at different times between 2004 and 2010. The strains were determined to belong to 4 different serovars. The Salmonella enterica strains belonged to the serovars Salmonella Enteritidis (n?=?23), Salmonella Infantis (n?=?14), Salmonella Munchen (n?=?2), and Salmonella Typhi (n?=?3). Forty-two Salmonella enterica strains were typed with PFGE methods using XbaI restriction enzyme and plasmid analysis. At the end of typing, 11 different PFGE band profiles were obtained. Four different PFGE profiles (type 1, 4, 9, and 10) were found among serotype S. Enteritidis species, 3 different PFGE profiles (type 3, 5, 6) were found among S. Infantis species, 2 different PFGE profiles were found among S. Typhi species (type 2 and 11), and 2 different PFGE profiles were found among S. Munchen species (type 7, 8). The UPGMA dendrogram was built on the PFGE profiles. In this study, it was determined that 4 strains of 42 Salmonella enterica strains possess no plasmid, while the isolates have 1–3 plasmids ranging from 5.0 to 150 kb and making 12 different plasmid profiles (P1–P12). In this study, we have applied the analysis of the PFGE patterns and used bioinformatics methods to identify both inter and intra serotype relationships of 4 frequently encountered serotypes for the first time in Turkey.

Ozdemir, Kerem; Acar, Sumeyra

2014-01-01

185

Polyclonal infections due to Mycobacterium avium complex in patients with AIDS detected by pulsed-field gel electrophoresis of sequential clinical isolates.  

PubMed Central

Invasive infection with organisms of the Mycobacterium avium complex (MAC) is common among patients with advanced human immunodeficiency virus infection. In previous studies, we analyzed multiple individual colonies of MAC isolated from specimens obtained at the same time and observed that 14 to 20% of patients are simultaneously infected with more than one strain. In this study, we examined sequential isolates from 12 patients with AIDS who had two or more MAC isolates available from clinical specimens collected more than 1 week apart; the intervals between the first and last specimens ranged from 8 to 192 (median, 46) days. For each isolate, restriction digests of genomic DNA were analyzed by pulsed-field gel electrophoresis; DNA was prepared by using a protocol, described here in detail, which had been optimized for conditions of bacterial growth and lysis. The pulsed-field gel electrophoresis analysis identified four patients (33%) infected with two different MAC strains. Both M. avium and M. intracellulare were cultured from blood specimens from two patients. In each of the four patients, the second strain was identified from a culture taken within 14 days of the initial study isolate, and in three of these patients, the first strain was detected again in a subsequent culture. These observations suggest that the presence of two different strains among isolates from sequential cultures may reflect ongoing polyclonal infection. We conclude that polyclonal infection with MAC is common among patients with AIDS. The identification of such infections may be critical in the development of effective treatments. Images

Slutsky, A M; Arbeit, R D; Barber, T W; Rich, J; von Reyn, C F; Pieciak, W; Barlow, M A; Maslow, J N

1994-01-01

186

Magnetic connections of solar formations inside magneto-isolated complexes based on observations of arch structures and calculations of magnetic field lines  

NASA Astrophysics Data System (ADS)

The magnetic connections of solar formations inside magneto-isolated complexes with areas outside the complexes were determined from the loop structures in the upper chromosphere and corona, as well as from calculations of magnetic field lines. It was found that 65% of the constructed field lines are closed within complexes or not closed on the solar surface, while 35% of the field lines intersect the boundary of the complex. Short field lines that intersect the boundary of the complex often connect the points of low intensity. The ends of the long field lines coincide with ends of the arch structures, whose higher parts are not visible in the 17.1 nm line. The short field lines coincide in position with the loop structures at the corona level. It was shown that there are three types of magnetic field variations depending on the height above the complexes.

Fainshtein, V. G.; Malashchuk, V. M.; Stepanian, N. N.; Rudenko, G. V.; Egorov, Ya. I.

2013-06-01

187

Application of Pulsed-Field Gel Electrophoresis and Binary Typing as Tools in Veterinary Clinical Microbiology and Molecular Epidemiologic Analysis of Bovine and Human Staphylococcus aureus Isolates  

Microsoft Academic Search

Thirty-eight bovine mammary Staphylococcus aureus isolates from diverse clinical, temporal, and geograph- ical origins were genotyped by pulsed-field gel electrophoresis (PFGE) after SmaI digestion of prokaryotic DNA and by means of binary typing using 15 strain-specific DNA probes. Seven pulsed-field types and four subtypes were identified, as were 16 binary types. Concordant delineation of genetic relatedness was documented by both

RUTH ZADOKS; WILLEM VAN LEEUWEN; HERMAN BARKEMA; OTLIS SAMPIMON; HENRI VERBRUGH; YNTE HEIN SCHUKKEN; ALEX VAN BELKUM

188

Pulsed-Field Gel Electrophoresis of Staphylococcus aureus Isolates from Atopic Patients Revealing Presence of Similar Strains in Isolates from Children and Their Parents  

Microsoft Academic Search

Skin colonization with Staphylococcus aureus is often associated with atopic dermatitis, and staphylococcal enterotoxins have been implicated in the etiology of atopic disease. In this study, the colonization of patients with atopic dermatitis and their parents was investigated in order to evaluate the possibility of intrafamiliar transmission. S. aureus strains were isolated from 30 of 45 patients (66%). In 19

Sonja Bonness; Christiane Szekat; Natalija Novak; Gabriele Bierbaum

189

Identification of nif genes in N2-fixing bacterial strains isolated from rice fields along the Yangtze River Plain.  

PubMed

The aim of this research was to identify nifH and nifHDKYE ' genes in twenty strains of N2-fixing heterotrophic bacteria isolated from rice fields in the Yangtze River Plain. Southern hybridization of the total DNA from each strain was performed with the Klebsiella pneumoniae nifHDKYE ' gene probe (6.2 kb Eco RI fragment from pSA30) and the Azospirillum brasilense nifH gene probe (0.6 kb Eco RI-Hin dIII fragment from pHU8). We found that Eco RI fragments of total DNA from Aeromonas hydrophila HY2, Bacillus azotoformans FD, Bacillus licheniformis NCH1, NCH5, WH4, Bacillus brevis NC2, Bacillus pumilus NC12, Bacillus cereus NCH2, Citrobacter freundii HY5, HY9, Derxia gummosa HZ5, Pseudomonas mendocina HZ1 and Pseudomonas pseudoalcaligenes WH3 were positively hybridized with both of the probes. Agrobacterium radiobacter HY17, Corynebacterium sp. HY12, YZ and Pseudomonas sp. HY11 had Eco RI fragments hybridized with the K. pneumoniae nifHDKYE ' gene probe. An Eco RI fragment of total DNA from Bacillus megaterium YY4 was positively hybridized to the A. brasilense nifH gene probe. No hybridization sign was found in the total DNA fragments from Alcaligenes cupidus YY6 and Corynebacterium sp. NC11 hybridized with either of the gene probes. The data provide the number and size of EcoRI fragments of the total DNA hybridized with the nif gene probes for these strains of rarely studied species, suggesting additional evidence for N2 fixing and nif gene diversity of N2-fixing bacteria in rice fields along the Yangtze River Plain. PMID:16463319

Xie, Guang Hui; Cui, Zongjun; Yu, Jun; Yan, Jing; Hai, Weili; Steinberger, Yosef

2006-01-01

190

Phylogenetic Analysis of Open Reading Frame 5 of Field Isolates of Equine Arteritis Virus and Identification of Conserved and Nonconserved Regions in the G LEnvelope Glycoprotein  

Microsoft Academic Search

The variation and phylogenetic relationship of open reading frame 5 (ORF5) of 3 different laboratory strains of the original prototype Bucyrus strain of equine arteritis virus (EAV), the modified live virus vaccine (ARVAC, Fort Dodge Laboratories), and 18 field isolates of EAV from North America and Europe were determined by comparison of their gene sequences. The viruses differed from the

UDENI B. R. BALASURIYA; PETER J. TIMONEY; WILLIAM H. McCOLLUM; N. JAMES MacLACHLAN

1995-01-01

191

Flooded Area and Plant Zonation in Isolated Wetlands in Well Fields in the Northern Tampa Bay Region, Florida, Following Reductions in Groundwater-Withdrawal Rates.  

National Technical Information Service (NTIS)

The purpose of this report is to (1) compare the extent and duration of the flooded area in isolated wetlands located in three regional well fields operated by Tampa Bay Water in the northern Tampa Bay region during a period before and a period after redu...

K. H. Haag W. R. Pfeiffer

2012-01-01

192

Cytometric measurement of in vitro inhibition of Plasmodium falciparum field isolates by drugs: a new approach for re-invasion inhibition study  

PubMed Central

Background A flow cytometric method is proposed to study in vitro drug sensitivity of Plasmodium falciparum. Standard [3H]-hypoxanthine incorporation assay gives only information on inhibition of maturation by drugs. This method is usable on field isolates and provides data on both inhibition of maturation and re-invasion. Methods The method is based on the staining of parasites with hydroethidine (HE) and thiazole orange (TO) which allow differential identification of early, trophozoite and late stage of the parasite by flow cytometry. Late stages of the parasites are obtained by incubation in culture for 24 hours. Reinvasion is followed by culturing parasitized red blood cells for 24 h more. Results Compared to the standard [3H]-hypoxanthine incorporation assay, it gave similar results as expressed by 50% inhibitory concentrations for chloroquine of laboratory strains and “fieldisolates. The effect of quinine on the schizont-ring transition was also explored using this method. First data on the inhibition of re-invasion induced by quinine are presented for both P. falciparum-cultured strains and field isolates. Discussion This method is simple to use event for field isolate study. It is suitable to analyse effect of drugs on steps of the parasite life cycle different for the maturation one. Using this method quinine was found to have a inhibitory effect on re-invasion of red cells by Plasmodium.

2014-01-01

193

Distribution of erythrocyte binding antigen 175 (EBA-175) gene dimorphic alleles in Plasmodium falciparum field isolates from Sudan  

PubMed Central

Background The Erythrocyte Binding Antigen (EBA) 175 has been considered as one of the most important Plasmodium falciparum (P. falciparum) merozoite ligands that mediate invasion of the erythrocytes through their sialated receptor: Glycophorin A (GPA). The effect of the EBA 175 dimorphic alleles (F and C) on the severity of the disease is not yet fully understood. Therefore this study was designed to assess the distribution of the divergent dimorphic alleles of P. falciparum EBA-175 (F and C) in three different geographical areas in Sudan and the possible association of this dimorphism with the severity of the disease. Methods A sum of 339 field isolates of P. falciparum obtained from patients in three different geographical areas in Sudan were screened for the dimorphic alleles (F, C) of the EBA-175 using nested PCR. Results The percentage of F, C, and mixed F/C alleles were; 41%, 51%, and 8% respectively. F and C alleles showed significantly different distributions in the various geographic areas (p?=?0.00). There was no significant association between malaria clinical manifestation and P. falciparum EBA-175 F and C alleles frequencies. Conclusions This study showed a significant differential distribution of F and C alleles in different geographical malaria endemic areas. No significant association was observed between F and C alleles and different malaria phenotypes.

2013-01-01

194

Insecticide resistance alleles affect vector competence of Anopheles gambiae s.s. for Plasmodium falciparum field isolates.  

PubMed

The widespread insecticide resistance raises concerns for vector control implementation and sustainability particularly for the control of the main vector of human malaria, Anopheles gambiae sensu stricto. However, the extent to which insecticide resistance mechanisms interfere with the development of the malignant malaria parasite in its vector and their impact on overall malaria transmission remains unknown. We explore the impact of insecticide resistance on the outcome of Plasmodium falciparum infection in its natural vector using three An. gambiae strains sharing a common genetic background, one susceptible to insecticides and two resistant, one homozygous for the ace-1(R) mutation and one for the kdr mutation. Experimental infections of the three strains were conducted in parallel with field isolates of P. falciparum from Burkina Faso (West Africa) by direct membrane feeding assays. Both insecticide resistant mutations influence the outcome of malaria infection by increasing the prevalence of infection. In contrast, the kdr resistant allele is associated with reduced parasite burden in infected individuals at the oocyst stage, when compared to the susceptible strain, while the ace-1 (R) resistant allele showing no such association. Thus insecticide resistance, which is particularly problematic for malaria control efforts, impacts vector competence towards P. falciparum and probably parasite transmission through increased sporozoite prevalence in kdr resistant mosquitoes. These results are of great concern for the epidemiology of malaria considering the widespread pyrethroid resistance currently observed in Sub-Saharan Africa and the efforts deployed to control the disease. PMID:23704944

Alout, Haoues; Ndam, Nicaise Tuikue; Sandeu, Marcel Maurice; Djégbe, Innocent; Chandre, Fabrice; Dabiré, Roch Kounbobr; Djogbénou, Luc Salako; Corbel, Vincent; Cohuet, Anna

2013-01-01

195

Characterization of genetic and biochemical mechanisms of fludioxonil and pyrimethanil resistance in field isolates of Penicillium digitatum.  

PubMed

Genetic and biochemical mechanisms of fludioxonil and pyrimethanil resistance in isolates of Penicillium digitatum were evaluated and compared to those characterized in other fungi. Resistant isolates were naturally occurring in packinghouses and were not associated with crop losses. For the phenylpyrrole fludioxonil, EC50 values were 0.02 to 0.04 microg/ml for sensitive, 0.08 to 0.65 microg/ml for moderately resistant (MR), and > 40 microg/ml for highly resistant (HR) isolates. Two fludioxonil-sensitive isolates evaluated were also significantly more sensitive to the unrelated dicarboximide fungicide iprodione, that also disrupts osmotic regulation, than the MR and HR isolates. There was no consistent relationship, however, between the HR and MR isolates and their sensitivity to iprodione or osmotic stress. Although, two nucleotide substitutions were found in a sequence analysis of the N-terminal amino acid repeat region of the os-1-related histidine kinase gene among isolates of P. digitatum, these were not correlated with fludioxonil resistance. In mycelia not exposed to fludioxonil, the amount of phosphorylated OS-2-related protein (PdOS-2) was higher in fludioxonil-sensitive isolates and lowest in the HR isolate. An increase in PdOS-2 was observed for sensitive and resistant isolates after exposure to fludioxonil. In addition, glycerol content in untreated mycelia of the fludioxonil-sensitive isolate was significantly higher than in resistant isolates. After exposure to fludioxonil, glycerol concentrations significantly increased in the sensitive and MR isolates, but not in the HR isolate. Thus, our studies indicate that the mode of action of fludioxonil in P. digitatum is probably the mitogen-activated protein kinase pathway that stimulates glycerol synthesis in sensitive and MR isolates. The general suppression of this pathway in resistant isolates was supported by the fact that growth and sporulation of MR and HR isolates were significantly reduced from that of sensitive isolates. In studies on the mode of action of anilinopyrimidines (AP), EC50 values for mycelial growth of P. digitatum and the previously characterized Botrytis cinerea were determined for cyprodinil and pyrimethanil using a defined culture medium without and with the addition of selected amino acids and homocysteine. The addition of amino acids resulted in a reduced toxicity of the two AP fungicides in both fungi, but the effect of each additive was significantly lower for P. digitatum than for B. cinerea. This suggests that methionine biosynthesis is not the primary target site of APs in P. digitatum. PMID:18943197

Kanetis, L; Förster, H; Jones, C A; Borkovich, K A; Adaskaveg, J E

2008-02-01

196

The Cytochrome P450 Lanosterol 14?-Demethylase Gene Is a Demethylation Inhibitor Fungicide Resistance Determinant in Monilinia fructicola Field Isolates from Georgia? †  

PubMed Central

Resistance in Monilinia fructicola to demethylation inhibitor (DMI) fungicides is beginning to emerge in North America, but its molecular basis is unknown. Two potential genetic determinants of DMI fungicide resistance including the 14?-demethylase gene (MfCYP51) and the ATP-binding cassette transporter gene MfABC1, were investigated in six resistant (DMI-R) and six sensitive (DMI-S) field isolates. No point mutations leading to an amino acid change were found in the MfCYP51 gene. The constitutive expression of the MfCYP51 gene in DMI-R isolates was significantly higher compared to DMI-S isolates. Gene expression was not induced in mycelium of DMI-R or DMI-S isolates treated with 0.3 ?g of propiconazole/ml. A slightly higher average MfCYP51 copy number value was detected in DMI-R isolates (1.35) compared to DMI-S isolates (1.13); however, this difference could not be verified in Southern hybridization experiments or explain the up to 11-fold-increased MfCYP51 mRNA levels in DMI-R isolates. Analysis of the upstream nucleotide sequence of the MfCYP51 gene revealed a unique 65-bp repetitive element at base pair position ?117 from the translational start site in DMI-R isolates but not in DMI-S isolates. This repetitive element contained a putative promoter and was named Mona. The link between Mona and the DMI resistance phenotype became even more apparent after studying the genetic diversity between the isolates. In contrast to DMI-S isolates, DMI-R isolates contained an MfCYP51 gene of identical nucleotide sequence associated with Mona. Still, DMI-R isolates were not genetically identical as revealed by Microsatellite-PCR analysis. Also, real-time PCR analysis of genomic DNA indicated that the relative copy number of Mona among DMI-S and DMI-R isolates varied, suggesting its potential for mobility. Interestingly, constitutive expression of the MfABC1 gene in DMI-R isolates was slightly lower than that of DMI-S isolates, but expression of the MfABC1 gene in DMI-R isolates was induced in mycelium after propiconazole treatment. Therefore, the MfABC1 gene may play a minor role in DMI fungicide resistance in M. fructicola. Our results strongly suggest that overexpression of the MfCYP51 gene is an important mechanism in conferring DMI fungicide resistance in M. fructicola field isolates from Georgia and that this overexpression is correlated with Mona located upstream of the MfCYP51 gene.

Luo, Chao-Xi; Schnabel, Guido

2008-01-01

197

Further observations on the problem of isolating Mycoplasma suipneumoniae from field cases of enzootic pneumonia in pigs  

PubMed Central

In previous work in this laboratory, Mycoplasma suipneumoniae was recovered in liquid medium from 13% of individual cases and 18% of outbreaks of enzootic pneumonia in pigs. In the work now described, however, these recovery rates, when judged by the same criteria, were 45 and 75%, respectively. As there was evidence to suggest that this second series of pneumonic cases was less suitable for cultural examination than the first series, some of the other factors that might have improved the recovery rate were investigated. Some improvement was probably achieved by inoculating the liquid medium with three or four different dilutions of pneumonic tissue, each dilution always being in duplicate, and by incubating the inoculated tubes for over 3 weeks before discarding them. A second advantage could have derived from the fact that all batches of liquid medium were tested for their ability to support the growth of M. suipneumoniae before being used to culture field material. The effect of varying one constituent at a time was observed in controlled experiments: different batches of pig sera had a marked, variable effect on the growth of both M. suipneumoniae and Mycoplasma hyorhinis; medium made with purchased Hartley's broth was found to be superior to medium incorporating broth made in this laboratory, more so for the growth of M. suipneumoniae than M. hyorhinis; the incorporation of yeast extract made in this laboratory gave a marginal advantage for the growth of M. hyorhinis; and both mycoplasmas grew equally well in medium containing or lacking thallium acetate. Some batches of medium were, by chance, markedly selective for the growth of M. suipneumoniae compared with M. hyorhinis. As the full reasons for this were not known, attempts were made to develop selective media in a more direct way. One such medium contained 5% pig serum and 15% horse serum, and a second was of similar composition, except that the pig serum used inhibited preferentially the growth of M. hyorhinis compared with M. suipneumoniae. Both media markedly favoured the growth of M. suipneumoniae when tested separately with cultures of M. suipneumoniae and M. hyorhinis. The second medium yielded M. suipneumoniae when inoculated with a 10-1 dilution of a culture of M. suipneumoniae and a 10-2 dilution of a culture of M. hyorhinis, whereas a standard batch of liquid medium, similarly inoculated with M. suipneumoniae did not yield this mycoplasma until the M. hyorhinis culture included in the inoculum was diluted to 10-6. Both selective media, when tested on a small number of field cases, gave improved isolations of M. suipneumoniae compared with the routine batches of liquid medium used initially. Considerable difficulty was experienced in producing a sufficiently high level of antibodies to M. hyorhinis in pig sera and to M. suipneumoniae in rabbit sera. This exacerbated the problem of isolating and identifying M. suipneumoniae from field cases of enzootic pneumonia by this cultural method.

Goodwin, R. F. W.; Hurrell, Joan M. W.

1970-01-01

198

Novel approach for the generation of recombinant African swine fever virus from a field isolate using GFP expression and 5-bromo-2'-deoxyuridine selection.  

PubMed

Generation of African swine fever virus (ASFV) recombinants has so far relied mainly on the manipulation of virus strains which had been adapted to growth in cell culture, since field isolates do not usually replicate efficiently in established cell lines. Using wild boar lung cells (WSL) which allow for propagation of ASFV field isolates, a novel approach for the generation of recombinant ASFV directly from field isolates was developed which includes the integration into the viral thymidine kinase (TK) locus of an ASFV p72-promoter driven expression cassette for enhanced green fluorescent protein (EGFP) embedded in a 16 kbp mini F-plasmid into the genome of the ASFV field strain NHV. This procedure enabled the monitoring of recombinant virus replication by EGFP autofluorescence. Selection for the TK-negative (TK(-)) phenotype of the recombinants on TK(-) Vero (VeroTK(-)) cells in the presence of 5-bromo-2'-deoxyuridine (BrdU) led to efficient isolation of recombinant virus due to the elimination of TK(+) wild type virus by BrdU-phosporylation in infected VeroTK(-) cells. The recombinant NHV-dTK-GFP produced titres of both cell-associated and secreted viral progeny in WSL cells similar to parental NHV indicating that insertion of large heterologous sequences into the viral TK locus and EGFP expression do not impair viral replication in these cells. In summary, a novel method has been developed for generation of ASFV recombinants directly from field isolates, providing an efficacious method for further manipulations of wild-type virus genomes. PMID:22498259

Portugal, Raquel; Martins, Carlos; Keil, Günther M

2012-07-01

199

Isolation of halophilic and halotolerant bacteria from a Japanese salt field and comparison of the partial 16S rRNA gene sequence of an extremely halophilic isolate with those of other extreme halophiles  

Microsoft Academic Search

Halophilic and halotolerant bacteria were isolated from soil samples of a Japanese salt field, an environment where salt concentrations vary annually. From 1 g of each of the five samples collected, over 1×103 bacterial colonies (colony forming units (cfu)g-1) grew on agar medium containing 2M Na+. In contrast, 0–4 bacterial colonies (cfu g-1) were observed on agar medium containing 4M

Tomonori Takashina; Kiyotaka Otozati; Tetsuo Hamamoto; Koki Horikoshi

1994-01-01

200

Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot.  

PubMed

Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninety-three Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple-sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil. PMID:24261409

Borrego-Benjumea, Ana; Basallote-Ureba, María J; Melero-Vara, José M; Abbasi, Pervaiz A

2014-04-01

201

Inhibitory activity of ferroquine, versus chloroquine, against western Kenya Plasmodium falciparum field isolates determined by a SYBR Green I in vitro assay.  

PubMed

Ferroquine (FQ), a chloroquine (CQ) analog, is being developed to treat persons with Plasmodium falciparum malaria. In 146 P. falciparum field isolates from western Kenya, we measured 50% inhibitory concentrations (IC(50); nM) of CQ and FQ by a SYBR Green I in vitro assay. Reference clones included W2 (CQ resistant) and D6 (CQ sensitive). Mutation analysis was done for P. falciparum CQ-resistance transporter gene (Pfcrt K76T). Median IC(50) values for FQ were lower than CQ for field isolates and the W2 clone (both P < 0.05). The Pfcrt mutation (76T), which was detected in > 80% of isolates, conferred higher CQ IC(50) values (P < 0.05) and modestly lower FQ IC(50) values (P < 0.05), versus Pfcrt wild type (K76). FQ is more potent than CQ against CQ-resistant P. falciparum field isolates and the W2 clone, and is less affected by Pfcrt 76T. These findings support the notion that FQ could be useful in treating persons with P. falciparum malaria. PMID:22144431

Eyase, Fredrick L; Akala, Hoseah M; Johnson, Jacob D; Walsh, Douglas S

2011-12-01

202

High Genetic Diversity of Enterococcus faecium and Enterococcus faecalis Clinical Isolates by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing from a Hospital in Malaysia  

PubMed Central

Little is known on the genetic relatedness and potential dissemination of particular enterococcal clones in Malaysia. We studied the antibiotic susceptibility profiles of Enterococcus faecium and Enterococcus faecalis and subjected them to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). E. faecium and E. faecalis displayed 27 and 30 pulsotypes, respectively, and 10 representative E. faecium and E. faecalis isolates (five each) yielded few different sequence types (STs): ST17 (2 isolates), ST78, ST203, and ST601 for E. faecium, and ST6, ST16, ST28, ST179, and ST399 for E. faecalis. Resistance to tazobactam-piperacillin and ampicillin amongst E. faecium isolates was highly observed as compared to E. faecalis isolates. All of the isolates were sensitive to vancomycin and teicoplanin. The presence of epidemic and nosocomial strains of selected E. faecium STs: 17, 78, and 203 and E. faecalis ST6 as well as high rates of resistance to multiple antibiotics amongst E. faecium isolates is of a particular concern.

Weng, Poh Leng; Ramli, Ramliza; Shamsudin, Mariana Nor; Cheah, Yoke-Kqueen; Hamat, Rukman Awang

2013-01-01

203

Role of Real-Time Molecular Typing in the Surveillance of Campylobacter Enteritis and Comparison of Pulsed-Field Gel Electrophoresis Profiles from Chicken and Human Isolates  

PubMed Central

The goal of the present study was to assess the contribution of real-time molecular typing, used alone or with clinical surveillance, to the prompt identification of clusters of Campylobacter enteritis. Potential poultry sources were sought by comparing the pulsed-field gel electrophoresis genotypes of human and fresh whole retail chicken isolates collected during the same study period. Among 183 human isolates, 82 (45%) had unique genotypes, 72 (39%) represented 26 clusters of 2 to 7 isolates each, and 29 (16%) represented three clusters of 8 to 11 isolates each. Molecular typing was useful for the confirmation of outbreaks suspected on the basis of epidemiological surveillance, but for most small clusters, no epidemiological link could be established. Thus, the added value of real-time molecular typing is questionable, since the numerous small clusters identified were of unclear public health significance. Among 177 chickens, 41 (23%) yielded campylobacter isolates; of these, 19 (46%) had genotypes similar to those of 41 (22%) human isolates. However, a temporal association was demonstrated in only a minority of cases, and most genotypes were present only in a single species, suggesting that sources other than chickens are important in human campylobacteriosis. Further investigation with samples from water and other possible environmental sources is needed to define the most efficient strategy for the application of molecular typing and identification of the source(s) of sporadic cases of campylobacteriosis.

Michaud, Sophie; Menard, Suzanne; Arbeit, Robert D.

2005-01-01

204

High genetic diversity of Enterococcus faecium and Enterococcus faecalis clinical isolates by pulsed-field gel electrophoresis and multilocus sequence typing from a hospital in Malaysia.  

PubMed

Little is known on the genetic relatedness and potential dissemination of particular enterococcal clones in Malaysia. We studied the antibiotic susceptibility profiles of Enterococcus faecium and Enterococcus faecalis and subjected them to pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). E. faecium and E. faecalis displayed 27 and 30 pulsotypes, respectively, and 10 representative E. faecium and E. faecalis isolates (five each) yielded few different sequence types (STs): ST17 (2 isolates), ST78, ST203, and ST601 for E. faecium, and ST6, ST16, ST28, ST179, and ST399 for E. faecalis. Resistance to tazobactam-piperacillin and ampicillin amongst E. faecium isolates was highly observed as compared to E. faecalis isolates. All of the isolates were sensitive to vancomycin and teicoplanin. The presence of epidemic and nosocomial strains of selected E. faecium STs: 17, 78, and 203 and E. faecalis ST6 as well as high rates of resistance to multiple antibiotics amongst E. faecium isolates is of a particular concern. PMID:23819125

Weng, Poh Leng; Ramli, Ramliza; Shamsudin, Mariana Nor; Cheah, Yoke-Kqueen; Hamat, Rukman Awang

2013-01-01

205

Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa Isolates Exhibiting Practical Field Resistance to a Demethylation Inhibitor Fungicide  

PubMed Central

We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen.

Hulvey, Jon; Popko, James T.; Sang, Hyunkyu; Berg, Andrew

2012-01-01

206

Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa isolates exhibiting practical field resistance to a demethylation inhibitor fungicide.  

PubMed

We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen. PMID:22798361

Hulvey, Jon; Popko, James T; Sang, Hyunkyu; Berg, Andrew; Jung, Geunhwa

2012-09-01

207

Isolation and Characterization of Methanothermobacter crinale sp. nov., a Novel Hydrogenotrophic Methanogen from the Shengli Oil Field?†  

PubMed Central

Syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis is an alternative methanogenic pathway in certain thermophilic anaerobic environments such as high-temperature oil reservoirs and thermophilic biogas reactors. In these environments, the dominant thermophilic methanogens were generally related to uncultured organisms of the genus Methanothermobacter. Here we isolated two representative strains, Tm2T and HMD, from the oil sands and oil production water in the Shengli oil field in the People's Republic of China. The type strain, Tm2T, was nonmotile and stained Gram positive. The cells were straight to slightly curved rods (0.3 ?m in width and 2.2 to 5.9 ?m in length), but some of them possessed a coccal shape connecting with the rods at the ends. Strain Tm2T grew with H2-CO2, but acetate is required. Optimum growth of strain Tm2T occurred in the presence of 0.025 g/liter NaCl at pH 6.9 and a temperature of 65°C. The G+C content of the genomic DNA was 40.1 mol% ± 1.3 mol% (by the thermal denaturation method) or 41.1 mol% (by high-performance liquid chromatography). Analysis of the 16S rRNA gene sequence indicated that Tm2T was most closely related to Methanothermobacter thermautotrophicus ?HT and Methanothermobacter wolfeii VKM B-1829T (both with a sequence similarity of 96.4%). Based on these phenotypic and phylogenic characteristics, a novel species was proposed and named Methanothermobacter crinale sp. nov. The type strain is Tm2T (ACCC 00699T = JCM 17393T).

Cheng, Lei; Dai, Lirong; Li, Xia; Zhang, Hui; Lu, Yahai

2011-01-01

208

Isolation and characterization of Methanothermobacter crinale sp. nov., a novel hydrogenotrophic methanogen from the Shengli oil field.  

PubMed

Syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis is an alternative methanogenic pathway in certain thermophilic anaerobic environments such as high-temperature oil reservoirs and thermophilic biogas reactors. In these environments, the dominant thermophilic methanogens were generally related to uncultured organisms of the genus Methanothermobacter. Here we isolated two representative strains, Tm2(T) and HMD, from the oil sands and oil production water in the Shengli oil field in the People's Republic of China. The type strain, Tm2(T), was nonmotile and stained Gram positive. The cells were straight to slightly curved rods (0.3 ?m in width and 2.2 to 5.9 ?m in length), but some of them possessed a coccal shape connecting with the rods at the ends. Strain Tm2(T) grew with H(2)-CO(2), but acetate is required. Optimum growth of strain Tm2(T) occurred in the presence of 0.025 g/liter NaCl at pH 6.9 and a temperature of 65°C. The G+C content of the genomic DNA was 40.1 mol% ± 1.3 mol% (by the thermal denaturation method) or 41.1 mol% (by high-performance liquid chromatography). Analysis of the 16S rRNA gene sequence indicated that Tm2(T) was most closely related to Methanothermobacter thermautotrophicus ?H(T) and Methanothermobacter wolfeii VKM B-1829(T) (both with a sequence similarity of 96.4%). Based on these phenotypic and phylogenic characteristics, a novel species was proposed and named Methanothermobacter crinale sp. nov. The type strain is Tm2(T) (ACCC 00699(T) = JCM 17393(T)). PMID:21705537

Cheng, Lei; Dai, Lirong; Li, Xia; Zhang, Hui; Lu, Yahai

2011-08-01

209

Reproductive isolation revealed in preliminary crossbreeding experiments using field collected Triatoma dimidiata (Hemiptera: Reduviidae) from three ITS-2 defined groups.  

PubMed

Triatoma dimidiata, a Chagas disease vector distributed in Mexico, Central America, Colombia, Venezuela, Peru and Ecuador, has been studied using genetic markers and four groups have been defined by ITS-2 sequences: 1A, 1B, 2 and 3. To gather evidence on the divergence and reproductive isolation among T. dimidiata ITS-2 groups, we carried out 15 crossbreeding experiments with field-collected sylvan and domestic T. dimidiata from Guatemala where three groups are found: 1A, 2 and 3. Reciprocal crosses between individuals from groups 1A and 2, and a cross between group 2 individuals from different habitats, produced an average 129.78±42.29 eggs with hatching success ranging from 31.6 to 90.1%. The offspring of these crosses reached the adult stage, and crosses between F1 insects produced eggs. These results suggest that there are no pre- or post-zygotic reproductive barriers between groups 1A and 2, or within group 2. Crosses between group 3 females and males from groups 1A or 2 produced on average 85.67±30.26 eggs and none of them hatched. These results support the existence of pre-zygotic barriers between T. dimidiata group 3 and groups 1A and 2. The group 3 individuals were collected in sylvatic environments in Yaxha, Peten, Guatemala. Previously, distinct chromosomal characteristics (cytotype 3) were described in individuals from this population. Based on this evidence we suggest that this population is divergent at the species level from other T. dimidiata populations. PMID:24041592

García, Mauricio; Menes, Marianela; Dorn, Patricia L; Monroy, Carlota; Richards, Bethany; Panzera, Francisco; Bustamante, Dulce María

2013-12-01

210

High prevalence of mutation in the Plasmodium falciparum dhfr and dhps genes in field isolates from Sabah, Northern Borneo  

PubMed Central

Background Sulphadoxine-pyrimethamine (SP) has been in use for the treatment of uncomplicated falciparum malaria in Malaysia since the 1970s and is still widely employed in spite of widespread clinical resistance. Resistance to SP is known to be mediated by mutations in the pfdhfr and pfdhps genes. The aim of the present study was to investigate the distribution of pfdhfr and pfdhps gene polymorphism in Plasmodium falciparum field isolates from Kalabakan, Sabah, in northern Borneo. Methods A total number of 619 individuals were screened from 23 study sites of which 31 were positive for P. falciparum. Analysis of restriction fragment length polymorphisms (RFLP) was used to identify polymorphism in the pfdhfr and pfdhps genes at positions 16, 51, 59, 108, 164 and 437, 540, 581, respectively. Results All samples had at least one mutation in each of the genes associated with drug resistance. The prevalence of pfdhfr 59arg, 164leu and 108asn were 100%, 80.65% and 58.06%, respectively. Pfdhps mutants 437gly and 581gly accounted for 100% and 74.19% respectively. In pfdhfr, the most common mutant genotypes were combination 59arg?+?164leu (22.58%) and 59arg?+?108asn?+?164leu (51.61%). In pfdhps the most common genotype was 437gly?+?581gly (74.19%). One individual (3.22%) harboured parasites with four pfdhfr (16 val?+?59arg?+?108asn?+?164leu) and two pfdhps (437gly?+?581gly) mutations. The highest quintuple pfdhfr/pfdhps (41.94%) was three pfdhfr (59arg?+?108asn?+?164gly) and two pfdhps (437gly?+?581gly). Conclusion The data suggest a high prevalence of genetic variations conferring resistance to SP which can predict treatment failure before becoming clinically evident. In areas like this, the use of SP may no longer be indicated.

2013-01-01

211

Phylogenetic analysis of classical swine fever virus (CSFV) field isolates from outbreaks in South and Central America  

Microsoft Academic Search

To date, there is little information concerning the epidemiological situation of classical swine fever (CSF) in the Americas. Besides summarizing the available data, genotyping of isolates from outbreaks in domestic pigs in several countries of South and Central America was performed. For this, a 190 base fragment of the E2 envelope glycoprotein gene was used. European strains and isolates, and

A. J. Pereda; I. Greiser-Wilke; B. Schmitt; M. A. Rincon; J. D. Mogollon; Z. Y. Sabogal; A. M. Lora; H. Sanguinetti; M. E. Piccone

2005-01-01

212

Optimizing the HRP-2 in vitro malaria drug susceptibility assay using a reference clone to improve comparisons of Plasmodium falciparum field isolates  

PubMed Central

Background Apparent emerging artemisinin-resistant Plasmodium falciparum malaria in Southeast Asia requires development of practical tools to monitor for resistant parasites. Although in vitro anti-malarial susceptibility tests are widely used, uncertainties remain regarding interpretation of P. falciparum field isolate values. Methods Performance parameters of the W2 P. falciparum clone (considered artemisinin “sensitive”) were evaluated as a reference for the HRP-2 immediate ex vivo assay. Variability in W2 IC50s was assessed, including intra- and inter-assay variability among and between technicians in multiple experiments, over five freeze-thaw cycles, over five months of continuous culture, and before and after transport of drug-coated plates to remote field sites. Nominal drug plate concentrations of artesunate (AS) and dihydroartemisinin (DHA) were verified by LC-MS analysis. Plasmodium falciparum field isolate IC50s for DHA from subjects in an artemisinin-resistant area in Cambodia were compared with W2 susceptibility. Results Plate drug concentrations and day-to-day technical assay performance among technicians were important sources of variability for W2 IC50s within and between assays. Freeze-thaw cycles, long-term continuous culture, and transport to and from remote sites had less influence. Despite variability in W2 susceptibility, the median IC50s for DHA for Cambodian field isolates were higher (p <0.0001) than the W2 clone (3.9 nM), both for subjects with expected (less than 72?hours; 6.3 nM) and prolonged (greater or equal to 72?hours; 9.6 nM) parasite clearance times during treatment with artesunate monotherapy. Conclusion The W2 reference clone improved the interpretability of field isolate susceptibility from the immediate ex vivo HRP-2 assay from areas of artemisinin resistance. Methods to increase the reproducibility of plate coating may improve overall assay interpretability and utility.

2012-01-01

213

Comparative analysis of genetic variability among Borrelia burgdorferi isolates from Europe and the United States by restriction enzyme analysis, gene restriction fragment length polymorphism, and pulsed-field gel electrophoresis.  

PubMed Central

The genomes of 62 North American and European Borrelia burgdorferi isolates were examined by restriction endonuclease analysis (REA), gene probe restriction fragment length polymorphism, and pulsed-field gel electrophoresis (PFGE). Hybridization of restriction fragments with the immunologically relevant 83-kDa antigen gene revealed polymorphisms and divided the isolates into three major groups. Group I included all but two of the American isolates and some of the European isolates. One of two Californian isolates (DN 127) and one Ixodes dammini isolate from New York (strain 25015), previously described as atypical, were distinct from the isolates in the three groups. Plasmid profile analysis and REA, the method with the highest level of discrimination, revealed extensive heterogeneity among isolates of the same major group. Our study demonstrates the usefulness of the 83-kDa antigen gene probe for dividing the isolates into major genogroups, whereas REA and plasmid profile analysis allow for a distinction of individual strains within these groups. Images

Zingg, B C; Anderson, J F; Johnson, R C; LeFebvre, R B

1993-01-01

214

Monoclonal antibody-based immunohistochemical detection of porcine epidemic diarrhea virus antigen in formalin-fixed, paraffin-embedded intestinal tissues.  

PubMed

An immunohistochemistry technique was developed for the diagnosis of porcine epidemic diarrhea virus (PEDV). The technique was tested on formalin-fixed, paraffin-embedded intestinal tissues from piglets naturally infected with PEDV. Five different monoclonal antibodies (MAbs) were tested in this study. PEDV antigen was consistently detected in the PLP (4% paraformaldehyde, 100 mM L-lysine dihydrochloride, 10 mM sodium m-periodate in phosphate-buffered saline)-fixed PEDV-infected Vero cells or formalin-fixed, paraffin-embedded intestinal tissues from piglets naturally infected with PEDV. The C9-2-2 MAb gave the strongest reactivity and least background staining, detecting 10 of 10 infected pigs. The positive reaction was cytoplasmic. Positive enterocytes were distributed over the tip and along the sides of atrophied or fused villi in the jejunum and ileum. Positive-staining cells were not detected in the crypts. No staining was observed in cecum and colon. No positive cells were observed when the C9-2-2 MAb was reacted with the tissue sections from noninfected piglets or from transmissible gastroenteritus virus (TGEV)- and rotavirus-infected piglets. The selected anti-PEDV MAbs tested on formalin-fixed, paraffin-embedded tissue sections are useful for diagnosis when virus isolation is not available. This method would be of particular value in countries where both PEDV and TGEV are epizootic and would aid in differentiating between PEDV and TGEV infection. PMID:12968761

Kim, O; Chae, C; Kweon, C H

1999-09-01

215

Genetic Diversity and Biological Control Activity of Novel Species of Closely Related Pseudomonads Isolated from Wheat Field Soils in South Australia  

PubMed Central

Rhizobacteria closely related to two recently described species of pseudomonads, Pseudomonas brassicacearum and Pseudomonas thivervalensis, were isolated from two geographically distinct wheat field soils in South Australia. Isolation was undertaken by either selective plating or immunotrapping utilizing a polyclonal antibody raised against P. brassicacearum. A subset of 42 isolates were characterized by amplified 16S ribosomal DNA restriction analysis (ARDRA), BIOLOG analysis, and gas chromatography-fatty acid methyl ester (GC-FAME) analysis and separated into closely related phenetic groups. More than 75% of isolates tested by ARDRA were found to have >95% similarity to either Pseudomonas corrugata or P. brassicacearum-P. thivervalensis type strains, and all isolates had >90% similarity to either type strain. BIOLOG and GC-FAME clustering showed a >70% match to ARDRA profiles. Strains representing different ARDRA groups were tested in two soil types for biological control activity against the soilborne plant pathogen Gaeumannomyces graminis var. tritici, the causative agent of take-all of wheat and barley. Three isolates out of 11 significantly reduced take-all-induced root lesions on wheat plants grown in a red-brown earth soil. Only one strain, K208, was consistent in reducing disease symptoms in both the acidic red-brown earth and a calcareous sandy loam. Results from this study indicate that P. brassicacearum and P. thivervalensis are present in Australian soils and that a level of genetic diversity exists within these two novel species but that this diversity does not appear to be related to geographic distribution. The result of the glasshouse pot trial suggests that some isolates of these species may have potential as biological control agents for plant disease.

Ross, Ian L.; Alami, Younes; Harvey, Paul R.; Achouak, Wafa; Ryder, Maarten H.

2000-01-01

216

Sequence Variation in the T-Cell Epitopes of the Plasmodium falciparum Circumsporozoite Protein among Field Isolates Is Temporally Stable: a 5-Year Longitudinal Study in Southern Vietnam  

PubMed Central

In an effort to decipher the nature and extent of antigen polymorphisms of malaria parasites in a setting where malaria is hypomesoendemic, we conducted a 5-year longitudinal study (1998 to 2003) by sequencing the Th2R and Th3R epitopes of the circumsporozoite protein (CSP) of 142 Plasmodium falciparum field isolates from Bao Loc, Vietnam. Samples were collected during the high-transmission season, September through December 1998 (n = 43), as well as from July 2000 to August 2001 (n = 34), September 2001 to July 2002 (n?= 33), and August 2002 to July 2003 (n = 32). Marked sequence diversity was noted during the high-transmission season in 1998, but no significant variation in allele frequencies was observed over the years (?2?= 70.003, degrees of freedom = 57, P = 0.116). The apparent temporal stability in allele frequency observed in this Bao Loc malaria setting may suggest that polymorphism in the Th2R and Th3R epitopes is not maintained by frequency-dependent immune selection. By including 36 isolates from Flores Island, Indonesia, and 19 isolates from Thaton, Myanmar, we investigated geographical patterns of sequence polymorphism for these epitopes in Southeast Asia; among the characterized isolates, a globally distributed variant appears to be predominant in Vietnam (75 of 142 isolates, or 52.8%) as well as in Myanmar (15 of 19 isolates, or 78.9%) and Indonesia (31 of 36 isolates, or 86.1%). Further analyses involving worldwide CSP sequences revealed distinct regional patterns, a finding which, together with the unique mutations observed here, may suggest a possible role for host or local factors in the generation of sequence diversity in the T-cell epitopes of CSP.

Jalloh, Amadu; van Thien, Huynh; Ferreira, Marcelo U.; Ohashi, Jun; Matsuoka, Hiroyuki; Kanbe, Toshio; Kikuchi, Akihiko; Kawamoto, Fumihiko

2006-01-01

217

Isolation of an avirulent mutant of Sendai virus with two amino acid mutations from a highly virulent field strain through adaptation to LLC-MK2 cells  

Microsoft Academic Search

A field strain of Sendai virus (SeV) Ohita-M1 (M1) was isolated from an epidemic in an animal lab- oratory by passaging in mice. A mutant strain, Ohita- MVC11 (MVC11), was then obtained by passaging M1 in rhesus monkey (LLC-MK2) cells. MVC11 was adapted to LLC-MK2 cells and produced 20 times higher levels of infectious virus than M1. This increased production

Masae Itoh; Yuji Isegawa; Hak Hott; Morio Homma

218

Molecular characterization of Salmonella enterica serotype Enteritidis isolates from humans by antimicrobial resistance, virulence genes, and pulsed-field gel electrophoresis.  

PubMed

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major serovar associated with human salmonellosis. A total of 425 clinical S. Enteritidis isolates of human origin were collected between June 2009 and September 2010 from North Carolina. The isolates were further characterized for antimicrobial susceptibility, antimicrobial resistance coding determinants, virulence genes, and fingerprint profiles to determine whether they were similar or different to the S. Enteritidis strain responsible for the human outbreak due to consumption of contaminated eggs. Ten different antimicrobial resistance phenotypes were observed with the highest frequency of resistance exhibited to ampicillin (n=10; 2.35%). The isolates were predominantly pansusceptible (n=409; 96.23%); however, seven isolates were multidrug resistant (MDR; i.e., resistant to three or more antimicrobials). Extended spectrum ?-lactamase (ESBL) coding genes (bla(TEM) and bla(PSE)) were detected in the ampicillin-resistant isolates, whereas a single MDR isolate tested positive for class 1 integron (1 kb). The majority of the isolates (n=422; 99.3%) carried the invA, mgtC, stn, sopB, sopE1, and sefA virulence genes. However, 37 (8.7%) and 46 (10.82%) S. Enteritidis isolates tested negative for the plasmid encoded genes spvC and rck, respectively. Pulsed-field gel electrophoresis (PFGE) typing of 118 S. Enteritidis isolates by restriction enzymes XbaI and BlnI resulted in seven clusters, each with a discriminatory index (DI) of 0.715 and 0.785, respectively. The combination of XbaI-BlnI patterns generated a dendrogram with 14 clusters and a higher DI of 0.914. The PFGE profile of 80 isolates matched 100% with the S. Enteritidis strain that has been cited for the recent outbreak in the United States due to consumption of contaminated eggs. In conclusion, we identified a genotypic similar S. Enteritidis population in our study based on antimicrobial susceptibility, virulence gene, and PFGE fingerprint profiles. PMID:22283616

Zou, Ming; Keelara, Shivaramu; Thakur, Siddhartha

2012-03-01

219

A New Approach to Isolating External Magnetic Field Components in Spacecraft Measurements of the Earth's Magnetic Field Using Global Positioning System observables  

NASA Technical Reports Server (NTRS)

We review the problem of separating components of the magnetic field arising from sources in the Earth's core and lithosphere, from those contributions arising external to the Earth, namely ionospheric and magnetospheric fields, in spacecraft measurements of the Earth's magnetic field.

Raymond, C.; Hajj, G.

1994-01-01

220

Stability and fitness of pyraclostrobin- and boscalid-resistant phenotypes in field isolates of Botrytis cinerea from apple.  

PubMed

Phenotype stability, fitness, and competitive ability of pyraclostrobin- and boscalid-resistant isolates of Botrytis cinerea from apple were investigated. Stability of resistance was determined after consecutive transfers on potato dextrose agar (PDA) or being cycled on apple fruit. In vitro fitness components mycelial growth, osmotic sensitivity, conidial germination, and sporulation were evaluated on agar media. Pathogenicity, virulence and sporulation on apple fruit were evaluated at both 20 and 0°C. Competition between fungicide-resistant and -sensitive isolates on apple fruit also was evaluated. Resistance to the two fungicides was retained at levels similar to that of the initial generation after 20 and 10 transfers on PDA and five and three disease cycles on apple fruit at 20 and 0°C, respectively. Great variability in individual fitness components tested was observed among isolates within the same phenotype groups either sensitive or resistant to the fungicides but, when compared as phenotype groups, there were no significant differences in the mean values of these fitness components between resistant and sensitive phenotypes except that the phenotype resistant only to boscalid produced fewer conidia in vitro than sensitive isolates. Resistant isolates were as pathogenic and virulent on apple fruit as sensitive isolates. There was no significant correlation between the values of individual fitness components tested and the level of resistance to pyraclostrobin or boscalid, except that virulence at 20°C positively correlated with the level of resistance to the two fungicides. The final frequency of pyraclostrobin-resistant individuals in the populations was significantly decreased compared with the initial generation and no boscalid-resistant individuals were detected after four disease cycles on apple fruit inoculated with a pair mixture of a dual-sensitive isolate and one isolate each of the three phenotypes resistant to pyraclostrobin, boscalid, or both. The results suggest that resistance of B. cinerea to pyraclostrobin and boscalid was stable in the absence of the fungicides and that resistance to the two fungicides did not significantly impair individual fitness components tested. However, both pyraclostrobin- and boscalid-resistant isolates exhibited competitive disadvantage over the dual-sensitive isolate on apple fruit. PMID:21692646

Kim, Y K; Xiao, C L

2011-11-01

221

Multilocus Sequence Typing Reveals a Lack of Diversity among Escherichia coli O157:H7 Isolates That Are Distinct by Pulsed-Field Gel Electrophoresis  

PubMed Central

Escherichia coli O157:H7 is a major cause of foodborne illness in the United States. Pulsed-field gel electrophoresis (PFGE) is the molecular epidemiologic method mostly commonly used to identify food-borne outbreaks. Although PFGE is a powerful epidemiologic tool, it has disadvantages that make a DNA sequence-based approach potentially attractive. Multilocus sequence typing (MLST) analyzes the internal fragments of housekeeping genes to establish genetic relatedness between isolates. We sequenced selected portions of seven housekeeping genes and two membrane protein genes (ompA and espA) of 77 isolates that were diverse by PFGE to determine whether there was sufficient sequence variation to be useful as an epidemiologic tool. There was no DNA sequence diversity in the sequenced portions of the seven housekeeping genes and espA. For ompA, all but five isolates had sequence identical to that of the reference strains. E. coli O157:H7 has a striking lack of genetic diversity in the genes we explored, even among isolates that are clearly distinct by PFGE. Other approaches to identify improved molecular subtyping methods for E. coli 0157:H7 are needed.

Noller, Anna C.; McEllistrem, M. Catherine; Stine, O. Colin; Morris, Jr., J. Glenn; Boxrud, David J.; Dixon, Bruce; Harrison, Lee H.

2003-01-01

222

Experimental and numerical investigation of the unsteady flow field and tone generation in an isolated centrifugal fan impeller  

Microsoft Academic Search

In spite of a low circumferential Mach number the sound of isolated centrifugal fan impellers is sometimes dominated by distinctive tones at blade passing frequency (BPF) and integer multiples. This paper reports on an experimental and numerical investigation intended to unveil the tone generating mechanism. The sound spectra from three impellers operating at a large range of speed were measured

Daniel Wolfram; Thomas H. Carolus

2010-01-01

223

Pulsed field, PCR ribotyping and multiplex PCR analysis of Yersinia enterocolitica strains isolated from meat food in San Luis Argentina  

Microsoft Academic Search

The characterization of phenotypic and genotypic virulence markers of Yersinia enterocolitica strains belonging to biotypes (B) 1A, 2 and 3, mostly isolated from food in San Luis, Argentina, and the assessment of their genotypic diversity using PFGE and PCR ribotyping, were performed in our laboratory for the first time. Thirty five Y. enterocolitica strains, two reference strains and 33 strains

Cecilia S. M. Lucero Estrada; Lidia del Carmen Velázquez; María Esther Escudero; Gabriela Isabel Favier; Valeria Lazarte; Ana María Stefanini de Guzmán

2011-01-01

224

Virulence and polar tube protein genetic diversity of Nosema ceranae (Microsporidia) field isolates from Northern and Southern Europe in honeybees (Apis mellifera iberiensis).  

PubMed

Infection of honeybees by the microsporidian Nosema ceranae is considered to be one of the factors underlying the increased colony losses and decreased honey production seen in recent years. However, these effects appear to differ in function of the climatic zone, the distinct beekeeping practices and the honeybee species employed. Here, we compared the response of Apis mellifera iberiensis worker bees to experimental infection with field isolates of N.?ceranae from an Oceanic climate zone in Northern Europe (Netherlands) and from a Mediterranean region of Southern Europe (Spain). We found a notable but non-significant trend (P?=?0.097) towards higher honeybee survival for bees infected with N.?ceranae from the Netherlands, although no differences were found between the two isolates in terms of anatomopathological lesions in infected ventricular cells or the morphology of the mature and immature stages of the parasite. In addition, the population genetic survey of the N. ceranae?PTP3 locus revealed high levels of genetic diversity within each isolate, evidence for meiotic recombination, and no signs of differentiation between the Dutch and Spanish populations. A cross-infection study is needed to further explore the differences in virulence observed between the two N.?ceranae populations in field conditions. PMID:24992540

Van der Zee, Romee; Gómez-Moracho, Tamara; Pisa, Lennard; Sagastume, Soledad; García-Palencia, Pilar; Maside, Xulio; Bartolomé, Carolina; Martín-Hernández, Raquel; Higes, Mariano

2014-08-01

225

Three-dimensional MHD simulation of FTEs produced by merging at an isolated point in a sheared magnetic field configuration  

NASA Astrophysics Data System (ADS)

We present predictions for the evolution of FTEs generated by localized bursts of reconnection on a planar magnetopause that separates a magnetosheath region of high densities and weak magnetic field from a magnetospheric region of low densities and strong magnetic field. The magnetic fields present a shear angle of 105 degrees. Reconnection forms a pair of FTEs each crossing the magnetopause in the field reversal region and bulging into the magnetosphere and magnetosheath. At their initial stage they can be characterized as flux tubes since the newly reconnected magnetic field lines are not twisted. Reconnection launches Alfvenic perturbations that propagate along the FTEs generating high-speed jets, which move the pair of FTEs in opposite directions. As the FTE moves, it displaces the ambient magnetic field and plasma producing bipolar magnetic field and plasma velocity signatures normal to the nominal magnetopause in the regions surrounding the FTE. The combination of the ambient plasma with the FTE flows generates a vortical velocity pattern around the reconnected field lines. During its evolution the FTE evolves to a flux rope configuration due to the twist of the magnetic field lines. The alfvenic perturbations propagate faster along the part of the FTE bulging into the magnetosphere than in the magnetosheath, and due to the differences between the plasma and magnetic field properties the perturbations have slightly different signatures in the two regions. As a consequence, the FTEs have different signatures depending on whether the satellite encounters the part bulging into the magnetosphere or into the magnetosheath.

Santos, J. C.; Sibeck, D. G.; Büchner, J.; Gonzalez, W. D.; Ferreira, J. L.

2014-03-01

226

A single isolated sub-50 attosecond pulse generation with a two-color laser field by a frequency-chirping technique  

NASA Astrophysics Data System (ADS)

We discuss the possibility of using the frequency-chirping technique to shorten the duration of the generated single attosecond pulse (SAP) by a two-color laser field of 800 and 1600 nm with few-cycle pulses. By adopting various combinations of the two frequency-chirped laser fields in our numerical simulation of ionizing He atom, we demonstrate that the best possible condition to obtain the shortest SAP is using the same chirping in both the fundamental and the half-harmonic laser fields without any phase effect and any delay time. There is a maximum increment of about 40 eV in the bandwidth of the XUV super-continuum in the cutoff (the second plateau) region. A single isolated attosecond pulse of 48 as can be generated that is further reduced to 9.7 as by phase compensation.

Zhao, Kun; Chu, Tianshu

2011-07-01

227

Comparative analysis of Mycobacterium avium subsp. paratuberculosis isolates from cattle, sheep and goats by short sequence repeat and pulsed-field gel electrophoresis typing  

PubMed Central

Background Mycobacterium avium subsp. paratuberculosis (Map) causes the chronic enteritis called paratuberculosis mainly in cattle, sheep and goats. Evidences that point out an association between Map and Crohn's Disease in humans are increasing. Strain differentiation among Map isolates has proved to be difficult and has limited the study of the molecular epidemiology of paratuberculosis. In order to asses the usefulness of the PCR based short sequence repeat (SSR) analysis of locus 1 and locus 8 in the epidemiological tracing of paratuberculosis strains we here compare for the first time the results of SSR and SnaBI-SpeI pulsed-field gel electrophoresis (PFGE) typing methods in a set of 268 Map isolates from different hosts (cattle, sheep, goats, bison, deer and wild boar). Results A total of nineteen different multi-locus SSR (SSR1_SSR8) types were identified amongst the 268 isolates compared to the 37 multiplex profiles differentiated by the SnaBI-SpeI PFGE. SSR type 7_4 was the predominant genotype (51.2% of all isolates and 54.3% of cattle isolates), but combined with PFGE results the abundance of the most prevalent genotype (7_4&{2-1}) dropped down to 37.7%. SSR types 7_3 and 14_3 were significantly spread amongst isolates recovered from small ruminants. The comparison of SSR1_SSR8 and SnaBI-SpeI PFGE typing of these isolates has shown that both methods perform at similar discriminatory level. These were 0.691 and 0.693, respectively for SSR and PFGE as indicated Simpson's Index of Diversity, and 0.82 when calculated for combined SSR and PFGE genotypes. Overall, SSR1_SSR8 analysis seemed to detect higher levels of within-farm strain diversity and seemed to give higher year-related information. Combination of both typing methods revealed 20 multi-type farms out of the 33 bovine farms studied with more than one isolate. Conclusion The particular SSR and PFGE typing approaches described here are in general agreement but they showed some discrepancies that might reflect differing evolutionary processes of Map strains. Both methods are able to reciprocally complement their results and neither should be replaced with the other if sufficient material and time is available. Overall, the results of our comparative analyses suggest that, based on current methodologies available, a combined approach that includes SSR and PFGE seems to provide the highest level of discrimination for Map strain typing with meaningful epidemiological information.

Sevilla, Iker; Li, Lingling; Amonsin, Alongkorn; Garrido, Joseba M; Geijo, Maria V; Kapur, Vivek; Juste, Ramon A

2008-01-01

228

Pulsed-field gel electrophoresis profile homogeneity of Mycobacterium avium subsp. paratuberculosis isolates from cattle and heterogeneity of those from sheep and goats  

PubMed Central

Background Mycobacterium avium subsp. paratuberculosis (Map) causes paratuberculosis in animals and is suspected of causing Crohn's Disease in humans. Characterization of strains led to classify paratuberculosis isolates in two main types, cattle type strains, found affecting all host species, and sheep type strains, reported affecting mainly sheep. In order to get a better understanding of the epidemiology of paratuberculosis a large set of Map isolates obtained from different species over the last 25 years have been characterized. Five-hundred and twenty isolates from different hosts (cattle, sheep, goats, bison, deer and wild boar) and origins had been cultured and typed by IS1311 restriction-endonuclease-analysis. Two-hundred and sixty-nine isolates were further characterized by pulsed-field gel electrophoresis (PFGE) using SnaBI and SpeI endonucleases. Differences in strain isolation upon various media conditions were also studied. Results All bovines, 4 and 26% of Spanish sheep and goats, respectively, and the deer and wild boar studied, carried IS1311-Cattle type strains. IS1311-Sheep type encompassed 96% and 74% of Spanish sheep and goats, and all three Portuguese sheep. Thirty-seven distinct multiplex PFGE profiles were found, giving 32 novel profiles. Profiles 2-1 and 1-1 accounted for the 85% of cattle isolates. Ten distinct profiles were detected in Spanish sheep, none of them with an incidence higher than 25%. Profile 16-11 (43%) and another three profiles were identified in Spanish caprine cultures. The hierarchical analysis, clustered all profiles found in cattle, "wild" hosts and some small ruminants within the same group. The other group included 11 profiles only found in Spanish sheep and goats, including Spanish pigmented profiles. Differences in growth requirements associated with isolate genotype were observed. Conclusion Cattle in Spain are infected with cattle type strains, while sheep and goats are mainly infected with sheep type strains. Although 7H9 broth based culture media seem to broadly cover the growth requirements of most Map strains, the use of various solid media is recommended to reduce any recovery biases. High genetic homogeneity of isolates from cattle, and heterogeneity of those from sheep and goats have been detected.

Sevilla, Iker; Garrido, Joseba M; Geijo, Marivi; Juste, Ramon A

2007-01-01

229

Prevalence of 5' insertion mutants and analysis of single nucleotide polymorphism in the erythrocyte binding-like 1 (ebl-1) gene in Kenyan Plasmodium falciparum field isolates.  

PubMed

Plasmodium merozoites attach to and invade red blood cells (RBCs) during the erythrocytic cycle. The invasion process requires recognition of RBC surface receptors by proteins of the Plasmodium Duffy binding like erythrocyte binding like (DBL-EBP) family. Clones and isolates of Plasmodium falciparum have varying abilities to utilize different RBC receptors, and multiple distinct pathways so far identified depend on glycophorins A, B, C, and as yet unidentified receptors. At present, five members of the DBL-EBP family have been identified in the P. falciparum genome, based on gene structure and amino acid sequence homology. The cardinal features of this family consist of conserved 5' and 3' cysteine-rich regions (regions II and VI, respectively) whose cysteine residues are highly conserved along with the majority of aromatic amino acids. In contrast to the single DBL-EBP family member in Plasmodium vivax, in P. falciparum all DBL-EBP family members have a duplication of the conserved 5' cysteine-rich region denoted as the F1 and F2 domains. These cysteine-rich regions are considered crucial in recognition of erythrocyte receptors and it has been shown that several bind to glycophorins on the erythrocyte surface. Several studies, on both field isolates and laboratory strains have uncovered a relatively high degree of sequence polymorphism in the DBP-EBL genes. This study is now extended to include field isolates collected from sites within Kenya. DNA isolated from blood samples of infected patients was utilized to amplify the region I sequence of ebl-1 gene in order to investigate polymorphism in the region immediately adjacent to the 5' cysteine-rich domains, and to determine the prevalence of an insertion mutant that effectively knocks out the gene. PMID:19879379

Githui, Elijah K; Peterson, David S; Aman, Rashid A; Abdi, Abdirahman I

2010-08-01

230

In vitro susceptibilities of field isolates of Mycoplasma agalactiae to oxytetracycline, tylosin, enrofloxacin, spiramycin and lincomycin–spectinomycin  

Microsoft Academic Search

The minimum inhibitory concentrations (MICs) of tetracycline, enrofloxacin, tylosin, spiramycin and a lincomycin:spectinomycin 1:2 combination, against 24 Sicilian isolates of Mycoplasma agalactiae, the causative organism of contagious agalactia were determined in vitro by a broth dilution method. Enrofloxacin was the most effective antimicrobial in vitro with a range of MIC values from 0.125 to 0.500?g\\/ml and an MIC50 of 0.203

G. R. Loria; C. Sammartino; R. A. J. Nicholas; R. D. Ayling

2003-01-01

231

Antimalarial Drug Sensitivity Profile of Western Kenya Plasmodium falciparum Field Isolates Determined by a SYBR Green I in vitro Assay and Molecular Analysis  

PubMed Central

In vitro drug sensitivity and molecular analyses of Plasmodium falciparum track drug resistance. DNA-binding fluorescent dyes like SYBR Green I may allow field laboratories, proximal to P. falciparum collection sites, to conduct drug assays. In 2007–2008, we assayed 121 P. falciparum field isolates from western Kenya for 50% inhibitory concentrations (IC50) against 6 antimalarial drugs using a SYBR Green I in vitro assay: 91 immediate ex vivo (IEV) and 30 culture-adapted, along with P. falciparum reference clones D6 (chloroquine [CQ] sensitive) and W2 (CQ resistant). We also assessed P. falciparum mdr1 (Pfmdr1) copy number and single nucleotide polymorphisms (SNPs) at four codons. The IC50s for IEV and culture-adapted P. falciparum isolates were similar, and approximated historical IC50s. For Pfmdr1, mean copy number was 1, with SNPs common at codons 86 and 184. The SYBR Green I assay adapted well to our field-based laboratory, for both IEV and culture-adapted P. falciparum, warranting continued use.

Akala, Hoseah M.; Eyase, Fredrick L.; Cheruiyot, Agnes C.; Omondi, Angela A.; Ogutu, Bernhards R.; Waters, Norman C.; Johnson, Jacob D.; Polhemus, Mark E.; Schnabel, David C.; Walsh, Douglas S.

2011-01-01

232

A Proteomics Screen Implicates HSP83 and a Small Kinetoplastid Calpain-related Protein in Drug Resistance in Leishmania donovani Clinical Field Isolates by Modulating Drug-induced Programmed Cell Death  

Microsoft Academic Search

The therapeutic mainstay against the protozoan parasite Leishmania is still based on the antiquated pentavalent antimonials (Sb(V)), but resistance is increasing in several parts of the world. Resistance is now partly understood in laboratory isolates, but our understanding of resistance in field isolates is lagging behind. We describe here a com- parative analysis of a genetically related pair of Sb(V)-

Baptiste Vergnes; Benjamin Gourbal; Isabelle Girard; Shyam Sundar; Jolyne Drummelsmith; Marc Ouellette

2006-01-01

233

Density functional theory and empirical derived force fields for the delocalized polaron form of polyaniline. Application to properties determination of an isolated oligomer using molecular dynamics simulations  

NASA Astrophysics Data System (ADS)

Normal mode analyses obtained from quantum chemical calculations at the DFT level of theory have been performed for the repetitive unit of the delocalized bipolaron form of polyaniline (PANI). Empirical molecular mechanics force field parameters were consecutively refined using the SPASIBA software and applied to the molecular dynamics properties of an isolated dodeca oligomer model of the leucoemeraldine form of PANI. It is shown that effects of protonation of the emeraldine base spread over the four rings constituting the repeating unit. Molecular dynamics simulations reveal alternative bendings of the whole chain with a time period of 18-20 ps for the model of PANI under study.

Cherrak, Z.; Lagant, P.; Benharrats, N.; Semmoud, A.; Hamdache, F.; Vergoten, G.

2005-05-01

234

Density functional theory and empirical derived force fields for the delocalized polaron form of polyaniline. Application to properties determination of an isolated oligomer using molecular dynamics simulations.  

PubMed

Normal mode analyses obtained from quantum chemical calculations at the DFT level of theory have been performed for the repetitive unit of the delocalized bipolaron form of polyaniline (PANI). Empirical molecular mechanics force field parameters were consecutively refined using the SPASIBA software and applied to the molecular dynamics properties of an isolated dodeca oligomer model of the leucoemeraldine form of PANI. It is shown that effects of protonation of the emeraldine base spread over the four rings constituting the repeating unit. Molecular dynamics simulations reveal alternative bendings of the whole chain with a time period of 18-20 ps for the model of PANI under study. PMID:15820875

Cherrak, Z; Lagant, P; Benharrats, N; Semmoud, A; Hamdache, F; Vergoten, G

2005-05-01

235

Molecular Typing and Epidemiological Study of Salmonella enterica Serotype Typhimurium Isolates from Cattle by Fluorescent Amplified-Fragment Length Polymorphism Fingerprinting and Pulsed-Field Gel Electrophoresis  

PubMed Central

One hundred twenty Salmonella enterica serotype Typhimurium strains, including 103 isolates from cattle gathered between 1977 and 1999 in the prefecture located on the northern-most island of Japan, were analyzed by using fluorescent amplified-fragment length polymorphism (FAFLP) and pulsed-field gel electrophoresis (PFGE) to examine the genotypic basis of the epidemic. Among these strains, there were 17 FAFLP profiles that formed four distinct clusters (A, B, C, and D). Isolates that belonged to cluster A have become increasingly common since 1992 with the increase of bovine salmonellosis caused by serotype Typhimurium. PFGE resolved 25 banding patterns that formed three distinct clusters (I, II, and III). All the isolates that belonged to FAFLP cluster A, in which all the strains of definitive phage type 104 examined were included, were grouped into PFGE cluster I. Taken together, these results indicate that clonal exchange of serotype Typhimurium has taken place since 1992, and they show a remarkable degree of homogeneity at a molecular level among contemporary isolates from cattle in this region. Moreover, we have sequenced two kinds of FAFLP markers, 142-bp and 132-bp fragments, which were identified as a polymorphic marker of strains that belonged to clusters A and C, respectively. The sequence of the 142-bp fragment shows homology with a segment of P22 phage, and that of the 132-bp fragment shows homology with a segment of traG, which is an F plasmid conjugation gene. FAFLP is apparently as well suited for epidemiological typing of serotype Typhimurium as is PFGE, and FAFLP can provide a source of molecular markers useful for studies of genetic variation in natural populations of serotype Typhimurium.

Tamada, Yukihiro; Nakaoka, Yuji; Nishimori, Kei; Doi, Akira; Kumaki, Takahiro; Uemura, Nobuko; Tanaka, Kiyoshi; Makino, Sou-Ichi; Sameshima, Toshiya; Akiba, Masato; Nakazawa, Muneo; Uchida, Ikuo

2001-01-01

236

Genetic polymorphism of merozoite surface protein 2 and prevalence of K76T pfcrt mutation in Plasmodium falciparum field isolates from Congolese children with asymptomatic infections  

PubMed Central

Background In order to prepare the field site for future interventions, the prevalence of asymptomatic Plasmodium falciparum infection was evaluated in a cohort of children living in Brazzaville. Plasmodium falciparum merozoite surface protein 2 gene (msp2) was used to characterize the genetic diversity and the multiplicity of infection. The prevalence of mutant P. falciparum chloroquine resistance transporter (pfcrt) allele in isolates was also determined. Methods Between April and June 2010, 313 children below 10 years of age enrolled in the cohort for malaria surveillance were screened for P. falciparum infection using microscopy and polymerase chain reaction (PCR). The children were selected on the basis of being asymptomatic. Plasmodium falciparum msp2 gene was genotyped by allele-specific nested PCR and the pfcrt K76T mutation was detected using nested PCR followed by restriction endonuclease digestion. Results The prevalence of asymptomatic P. falciparum infections was 8.6% and 16% by microscopy and by PCR respectively. Allele typing of the msp2 gene detected 55% and 45% of 3D7 and FC27 allelic families respectively. The overall multiplicity of infections (MOI) was 1.3. A positive correlation between parasite density and multiplicity of infection was found. The prevalence of the mutant pfcrt allele (T76) in the isolates was 92%. Conclusion This is the first molecular characterization of P. falciparum field isolates in Congolese children, four years after changing the malaria treatment policy from chloroquine (CQ) to artemisinin-based combination therapy (ACT). The low prevalence of asymptomatic infections and MOI is discussed in the light of similar studies conducted in Central Africa.

2012-01-01

237

Geometric Morphometrics of Nine Field Isolates of Aedes aegypti with Different Resistance Levels to Lambda-Cyhalothrin and Relative Fitness of One Artificially Selected for Resistance  

PubMed Central

Aedes aegypti, a mosquito closely associated with humans, is the principal vector of dengue virus which currently infects about 400 million people worldwide. Because there is no way to prevent infection, public health policies focus on vector control; but insecticide-resistance threatens them. However, most insecticide-resistant mosquito populations exhibit fitness costs in absence of insecticides, although these costs vary. Research on components of fitness that vary with insecticide-resistance can help to develop policies for effective integrated management and control. We investigated the relationships in wing size, wing shape, and natural resistance levels to lambda-cyhalothrin of nine field isolates. Also we chose one of these isolates to select in lab for resistance to the insecticide. The main life-traits parameters were assessed to investigate the possible fitness cost and its association with wing size and shape. We found that wing shape, more than wing size, was strongly correlated with resistance levels to lambda-cyhalothrin in field isolates, but founder effects of culture in the laboratory seem to change wing shape (and also wing size) more easily than artificial selection for resistance to that insecticide. Moreover, significant fitness costs were observed in response to insecticide-resistance as proved by the diminished fecundity and survival of females in the selected line and the reversion to susceptibility in 20 generations of the non-selected line. As a practical consequence, we think, mosquito control programs could benefit from this knowledge in implementing efficient strategies to prevent the evolution of resistance. In particular, the knowledge of reversion to susceptibility is important because it can help in planning better strategies of insecticide use to keep useful the few insecticide-molecules currently available.

Jaramillo-O., Nicolas; Fonseca-Gonzalez, Idalyd; Chaverra-Rodriguez, Duverney

2014-01-01

238

Isolated-attosecond-pulse generation from asymmetric molecules with an {omega}+2{omega}/3 multicycle two-color field  

SciTech Connect

The high harmonic generation from asymmetric molecules with an {omega}+2{omega}/3 multicycle bichromatic laser pulse has been investigated. It is shown that the ionization asymmetry in consecutive half optical cycles for asymmetric molecules is further enhanced since the 2{omega}/3 control laser pulse further enhances the amplitude of the ionization peak at the center of the laser pulse. The 2{omega}/3 control laser pulse also significantly enlarges the difference of the photon energies emitted from the ejected electron in the half optical cycle at the central laser pulse and its next half optical cycle. In addition, a broadband supercontinuum is produced in the plateau of the spectrum, from which an isolated 90-as pulse can be directly obtained.

Li Qianguang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Physics, Xiaogan University, Xiaogan 432000 (China); Hong Weiyi; Zhang Qingbin; Wang Shaoyi; Lu Peixiang [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-05-15

239

Observations and simulations of the wind structure in the boundary layer around an isolated mountain during the MATERHORN field experiment  

NASA Astrophysics Data System (ADS)

We investigate atmospheric boundary layer structure and dynamics during an intensive observational period of the Mountain Terrain Atmospheric Modeling and Observations (MATERHORN) Program at Dugway Proving Ground (an army test range in Utah, USA) in Fall 2012. We use high-resolution data from an airborne Doppler lidar that reveal the interaction of the synoptic flows with the evolution of slope and valley flows around an isolated mountain of a horizontal and vertical scale of about 10 km and 1 km, respectively. The measurements at high spatiotemporal resolution allow a thorough evaluation of the Four-Dimensional Weather System (4DWX), a state-of-the-art meteorological analysis, forecast, and decision-support system which is used operationally at Dugway Proving Ground. We also perform very large eddy simulations using 4DWX to investigate in more detail the turbulent structures and their impact on flow dynamics in the convective boundary layer.

De Wekker, S.; Liu, Y.; Knievel, J. C.; Pal, S.; Emmitt, G. D.

2013-12-01

240

Pulsed-Field Gel Electrophoresis Analysis of Vibrio vulnificus Strains Isolated from Taiwan and the United States  

Microsoft Academic Search

Vibrio vulnificus is a marine bacterium that causes human wound infections and septicemia with a high mortality rate. V. vulnificus strains from different clinical and environmental sources or geographic regions have been successfully characterized by ribotyping and several other methods. Pulsed-field gel electrophoresis (PFGE) is a highly discriminative method, but previous studies suggested that it was not suitable for examining

Hin-chung Wong; Shau-Yan Chen; Meng-Yi Chen; James D. Oliver; Lien-I Hor; Wen-Cherng Tsai

2004-01-01

241

Recording performance and thermal stability in perpendicular media with enhancement of grain isolation as well as magnetic anisotropy field  

NASA Astrophysics Data System (ADS)

Magnetic clustering, thermal stability, and recording performance on perpendicular media with multilayered magnetic anisotropy field (Hk)-gradient CoPtCr-oxide/Cap layers with various Ru-oxide layer thicknesses (tRu-oxide) on top of Ru/NiW layers are investigated. With increasing tRu-oxide from 0 to 1.3 nm, Hc and Hs are enhanced but Hn is reduced. Magnetic correlation length (Dn) extracted from a set of major and minor loops significantly decreases but intrinsic switching field distribution remains unaffected. A short-time switching field (Ho) proportional to Hk increases linearly while KuV/kT remains unchanged. Similar KuV/kT is explained by compensation of the reduced Dn with the enhanced Ku induced by a thin Ru-oxide. However, thermal decay rate degrades from 0.06 to 0.32%/decade, which correlates well with Hn. Similar values of initial minor loop slopes indicate no change in magnetic switching behavior. A 1 nm-thick Ru-oxide layer as a well-defined granular template significantly improves recording performance: narrower MCW at 10 T by 8 nm and higher SNR at 2 T by 1.4 dB are observed even at lower OW by 8 dB compared to the media without Ru-oxide. All the recording parameters as a function of Dn correlate well.

Jung, H. S.; Ikeda, Y.; Choe, G.; Shi, Zhupei

2012-04-01

242

Microbial diversity in Los Azufres geothermal field (Michoacán, Mexico) and isolation of representative sulfate and sulfur reducers.  

PubMed

Los Azufres spa consists of a hydrothermal spring system in the Mexican Volcanic Axis. Five samples (two microbial mats, two mud pools and one cenote water), characterized by high acidity (pH between 1 and 3) and temperatures varying from 27 to 87 °C, were investigated for their microbial diversity by Terminal-Restriction Fragment Length Polymorphism (T-RFLP) and 16S rRNA gene library analyses. These data are the first to describe microbial diversity from Los Azufres geothermal belt. The data obtained from both approaches suggested a low bacterial diversity in all five samples. Despite their proximity, the sampling points differed by their physico-chemical conditions (mainly temperature and matrix type) and thus exhibited different dominant bacterial populations: anoxygenic phototrophs related to the genus Rhodobacter in the biomats, colorless sulfur oxidizers Acidithiobacillus sp. in the warm mud and water samples, and Lyzobacter sp.-related populations in the hot mud sample (87 °C). Molecular data also allowed the detection of sulfate and sulfur reducers related to Thermodesulfobium and Desulfurella genera. Several strains affiliated to both genera were enriched or isolated from the mesophilic mud sample. A feature common to all samples was the dominance of bacteria involved in sulfur and iron biogeochemical cycles (Rhodobacter, Acidithiobacillus, Thiomonas, Desulfurella and Thermodesulfobium genera). PMID:24446065

Brito, Elcia M S; Villegas-Negrete, Norberto; Sotelo-González, Irene A; Caretta, César A; Goñi-Urriza, Marisol; Gassie, Claire; Hakil, Florence; Colin, Yannick; Duran, Robert; Gutiérrez-Corona, Felix; Piñón-Castillo, Hilda A; Cuevas-Rodríguez, Germán; Malm, Olaf; Torres, João P M; Fahy, Anne; Reyna-López, Georgina E; Guyoneaud, Rémy

2014-03-01

243

Are isolated wetlands isolated?  

USGS Publications Warehouse

While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

Smith, Loren M.; Euliss, Ned H., Jr.; Haukos, David A.

2011-01-01

244

Leishmania aethiopica Field Isolates Bearing an Endosymbiontic dsRNA Virus Induce Pro-inflammatory Cytokine Response  

PubMed Central

Background Infection with Leishmania parasites causes mainly cutaneous lesions at the site of the sand fly bite. Inflammatory metastatic forms have been reported with Leishmania species such as L. braziliensis, guyanensis and aethiopica. Little is known about the factors underlying such exacerbated clinical presentations. Leishmania RNA virus (LRV) is mainly found within South American Leishmania braziliensis and guyanensis. In a mouse model of L. guyanensis infection, its presence is responsible for an hyper-inflammatory response driven by the recognition of the viral dsRNA genome by the host Toll-like Receptor 3 leading to an exacerbation of the disease. In one instance, LRV was reported outside of South America, namely in the L. major ASKH strain from Turkmenistan, suggesting that LRV appeared before the divergence of Leishmania subgenera. LRV presence inside Leishmania parasites could be one of the factors implicated in disease severity, providing rationale for LRV screening in L. aethiopica. Methodology/Principal Findings A new LRV member was identified in four L. aethiopica strains (LRV-Lae). Three LRV-Lae genomes were sequenced and compared to L. guyanensis LRV1 and L. major LRV2. LRV-Lae more closely resembled LRV2. Despite their similar genomic organization, a notable difference was observed in the region where the capsid protein and viral polymerase open reading frames overlap, with a unique ?1 situation in LRV-Lae. In vitro infection of murine macrophages showed that LRV-Lae induced a TLR3-dependent inflammatory response as previously observed for LRV1. Conclusions/Significance In this study, we report the presence of an immunogenic dsRNA virus in L. aethiopica human isolates. This is the first observation of LRV in Africa, and together with the unique description of LRV2 in Turkmenistan, it confirmed that LRV was present before the divergence of the L. (Leishmania) and (Viannia) subgenera. The potential implication of LRV-Lae on disease severity due to L. aethiopica infections is discussed.

Zangger, Haroun; Hailu, Asrat; Desponds, Chantal; Lye, Lon-Fye; Akopyants, Natalia S.; Dobson, Deborah E.; Ronet, Catherine; Ghalib, Hashim; Beverley, Stephen M.; Fasel, Nicolas

2014-01-01

245

Isolation of a field strain of Brucella abortus from RB51-vaccinated- and brucellosis-seronegative bovine yearlings that calved normally.  

PubMed

A study was carried out in Pichucalco, Chiapas (Mexico) to determine whether recently calved cows or those that aborted shed Brucella. Serological diagnosis of brucellosis was made in all animals (209). Six of the cows that calved normally and two that aborted underwent a bacteriological study of milk and vaginal exudate. Brucella abortus was isolated from vaginal exudate samples in two 3- to 4-year-old seronegative first-birth cows that had calved normally. This was confirmed through bacteriological identification and PCR as a field strain and smooth phenotypes. We conclude that seronegative cows vaccinated with RB51 which calved normally and shed B. abortus in the vaginal exudate after calving could be a serious problem because these cows are overlooked in routine diagnoses and are a source of Brucella infection. PMID:22956439

Arellano-Reynoso, Beatriz; Suárez-Güemes, Francisco; Estrada, Félix Mejía; Michel-GómezFlores, Fernando; Hernández-Castro, Rigoberto; Acosta, Rómulo Beltrán; Díaz-Aparicio, Efrén

2013-02-01

246

Flavobacterium panaciterrae sp. nov., a ?-glucosidase producing bacterium with ginsenoside-converting activity isolated from the soil of a ginseng field.  

PubMed

The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain DCY69(T) is JX233806. A Gram-reaction-negative, oxidase- and catalase-positive, non-gliding motile strain, designated strain DCY69(T), was isolated from the soil of a ginseng field in the Republic of Korea. Colonies of strain DCY69(T) were circular, 0.5-1.5 mm diameter, yellow, and convex on an R2A agar plate after 2 days. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain DCY69(T) belonged to the genus Flavobacterium with 90.5-98.3% gene sequence similarity. The major predominant quinone was MK-6. The major cellular fatty acids were iso-C15:0, iso-C17:0 3-OH, iso-C15:0 3-OH and summed feature 3 (containing C16:1?7c and/or C16:1?6c). The major polar lipids were phosphatidylethanolamine, one unidentified aminolipid and unidentified polar lipids (L1, L2). The genomic DNA G+C content of strain DCY69(T) was 35.0mol%. The strain DCY69(T) transformed ginsenoside Rb1 into Rd and F2. Based on the polyphasic taxonomic data, strain DCY69(T) is considered to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium panaciterrae sp. nov. is proposed. The type strain is DCY69(T)(= KCTC 32392(T) = JCM 19161(T)), isolated from the soil of a ginseng field in the Republic of Korea. PMID:24859863

Jin, Yan; Kim, Yeon-Ju; Hoang, Van-An; Young Jung, Sun; Nguyen, Ngoc-Lan; Woo Min, Jin; Wang, Chao; Yang, Deok-Chun

2014-01-01

247

Isolated colonic tuberculosis  

Microsoft Academic Search

Two cases of isolated colonic tuberculosis are reported, and recent literature on this field is reviewed. Isolated colonic tuberculosis is defined as a tuberculosis which exists in the colon except for ileocaecum, without focus in any other organ. The morphological changes are tuberculous granulation primarily located to the submucosa layer of the colon with smooth surfaces of both mucous and

Y. A. Wang; W. Y. Yu

1987-01-01

248

Benchmark Database on Isolated Small Peptides Containing an Aromatic Side Chain: Comparison Between Wave Function and Density Functional Theory Methods and Empirical Force Field  

SciTech Connect

A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A)—where F and W are of aromatic character—is presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbone–aromatic side chain intramolecular interaction. Consequently, an accurate theoretical study of these systems requires the use of a methodology covering properly the London dispersion forces. For this reason we have assessed the performance of the MP2, SCS-MP2, MP3, TPSS-D, PBE-D, M06-2X, BH&H, TPSS, B3LYP, tight-binding DFT-D methods and ff99 empirical force field compared to CCSD(T)/complete basis set (CBS) limit benchmark data. All the DFT techniques with a ‘-D’ symbol have been augmented by empirical dispersion energy while the M06-2X functional was parameterized to cover the London dispersion energy. For the systems here studied we have concluded that the use of the ff99 force field is not recommended mainly due to problems concerning the assignment of reliable atomic charges. Tight-binding DFT-D is efficient as a screening tool providing reliable geometries. Among the DFT functionals, the M06-2X and TPSS-D show the best performance what is explained by the fact that both procedures cover the dispersion energy. The B3LYP and TPSS functionals—not covering this energy—fail systematically. Both, electronic energies and geometries obtained by means of the wave-function theory methods compare satisfactorily with the CCSD(T)/CBS benchmark data.

Valdes, Haydee; Pluhackova, Kristyna; Pitonak, Michal; Rezac, Jan; Hobza, Pavel

2008-03-13

249

Benchmark database on isolated small peptides containing an aromatic side chain: comparison between wave function and density functional theory methods and empirical force field.  

PubMed

A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A) -- where F and W are of aromatic character -- is presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbone-aromatic side chain intramolecular interaction. Consequently, an accurate theoretical study of these systems requires the use of a methodology covering properly the London dispersion forces. For this reason we have assessed the performance of the MP2, SCS-MP2, MP3, TPSS-D, PBE-D, M06-2X, BH&H, TPSS, B3LYP, tight-binding DFT-D methods and ff99 empirical force field compared to CCSD(T)/complete basis set (CBS) limit benchmark data. All the DFT techniques with a '-D' symbol have been augmented by empirical dispersion energy while the M06-2X functional was parameterized to cover the London dispersion energy. For the systems here studied we have concluded that the use of the ff99 force field is not recommended mainly due to problems concerning the assignment of reliable atomic charges. Tight-binding DFT-D is efficient as a screening tool providing reliable geometries. Among the DFT functionals, the M06-2X and TPSS-D show the best performance what is explained by the fact that both procedures cover the dispersion energy. The B3LYP and TPSS functionals-not covering this energy-fail systematically. Both, electronic energies and geometries obtained by means of the wave-function theory methods compare satisfactorily with the CCSD(T)/CBS benchmark data. PMID:18464990

Valdes, Haydee; Pluhácková, Kristýna; Pitonák, Michal; Rezác, Jan; Hobza, Pavel

2008-05-21

250

Effects of songs and calls on ZENK expression in the auditory telencephalon of field- and isolate-reared black capped chickadees.  

PubMed

We examined the effects of hearing two different conspecific vocalizations on expression of the immediate-early gene ZENK in the caudomedial neostriatum (NCM) and the caudomedial portion of the ventral hyperstriatum (cmHV) in male and female black-capped chickadees (Poecile atricapilla). Both the fee-bee song and the chick-a-dee call induced Zenk protein expression in NCM and in cmHV, however, patterns of expression to songs and calls varied across brain region. In the dorsal region of NCM, fee-bee songs induced more Zenk expression than chick-a-dee calls. In ventral NCM and cmHV, Zenk expression did not differ between songs and calls. We found that sex of the listener also affected Zenk expression: there was more robust ZENK response in males than in females. Finally, we compared field- and isolate-reared chickadees and found similar Zenk expression to fee-bee song in each group. These findings indicated that the type of conspecific vocalization, as well as the sex of the listener, appear to modulate IEG expression in the songbird ascending auditory pathway. PMID:14659578

Phillmore, Leslie S; Bloomfield, Laurie L; Weisman, Ronald G

2003-12-17

251

Isolated thallus-associated compounds from the macroalga Fucus vesiculosus mediate bacterial surface colonization in the field similar to that on the natural alga.  

PubMed

This study investigated whether surface-associated compounds isolated from the macroalga Fucus vesiculosus had the potential to mediate microbial and/or macrobial epibiosis similar to that on the natural alga. To selectively yield thallus-associated compounds and avoid contamination by intracellular algal compounds, cell lysis was monitored by surface microscopy of algal cells and chemical profiling of algal surface extracts by coupled gas chromatography mass spectroscopy. The optimized extraction resulted in polar and non-polar algal surface extracts. The non-polar surface extract was immobilized in hydrogel, the polar surface extract was homogeneously perfused through the gel to ensure a temporally constant delivery of polar extract components. During a 7 day field trial, bacterial biofilms were formed on control gels and gels featuring polar and/or non-polar extract components. PERMANOVA revealed that bacterial community profiles on controls and on gels featuring polar or non-polar extract were significantly different from the profile on F. vesiculosus, while the profile on the gels bearing both polar and non-polar extracts was not. Moreover, the polar surface extracts inhibited the settlement of barnacle cyprids. Considering the pronounced effects of bacterial biofilms on invertebrate larval settlement, these results suggest that algal surface chemistry affects macrofouling not only directly but also indirectly, via its control of biofilm formation and composition. PMID:20054721

Lachnit, Tim; Wahl, Martin; Harder, Tilmann

2010-01-01

252

Comparative purification and characterization of two distinct extracellular monocrotophos hydrolases secreted by Penicillium aculeatum and Fusarium pallidoroseum isolated from agricultural fields.  

PubMed

The present study aimed at a comparative characterization of two distinct extracellular monocrotophos hydrolases, from Penicillium aculeatum ITCC 7980.10 (M3) and Fusarium pallidoroseum ITCC 7785.10 (M4), isolated from agricultural fields. The MCP hydrolases were purified by Sephadex G-100 column and DEAE-Sepharose CL-6B ion-exchange column followed by SDS-PAGE analysis, which showed the presence of two hydrolases, of 33 and 67 kDa respectively. Both enzymes were most active at alkaline pH and were stable over a wide range of temperatures (60-70 °C). Between the strains, the MCP hydrolases from M3 were 2-fold more active than that from M4. Enzyme kinetic studies showed lowest Km (33.52 mM) and highest Vmax (5.18 U/mg protein) for OPH67 of M3 in comparison to the Km and Vmax of the other hydrolases purified from M3 and M4, suggesting that M3 OPH67 was the most efficient MCP hydrolase. To the best of our knowledge, this is the first report of the purification of two distinct extracellular thermostable MCP hydrolases from fungal strains Penicillium aculeatum ITCC 7980.10 and Fusarium pallidoroseum ITCC 7785.10. Owing to its potential MCP hydrolyzing activity, M3 OPH67 can perhaps used directly or in the encapsulated form for remediation of MCP contaminated sites. PMID:23666511

Jain, Rachna; Garg, Veena; Dangwal, Koushalya; Lily, Madhuri Kaushish

2013-01-01

253

The rph1 gene is a common contributor to the evolution of phosphine resistance in independent field isolates of Rhyzopertha dominica.  

PubMed

Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks. PMID:22363668

Mau, Yosep S; Collins, Patrick J; Daglish, Gregory J; Nayak, Manoj K; Pavic, Hervoika; Ebert, Paul R

2012-01-01

254

Sediminibacterium ginsengisoli sp. nov., isolated from soil of a ginseng field, and emended descriptions of the genus Sediminibacterium and of Sediminibacterium salmoneum.  

PubMed

A Gram-negative bacterium, designated DCY13(T), was isolated from soil of a ginseng field in South Korea. Comparative analysis of 16S rRNA gene sequences showed that strain DCY13(T) shared the highest sequence similarity (95.0?%) with Sediminibacterium salmoneum NBRC 103935(T) and 87.6-91.4?% sequence similarity with other members of the family Chitinophagaceae. Cells were non-spore-forming rods, catalase- and oxidase-positive, motile by gliding and facultatively anaerobic. The only respiratory quinone was menaquinone 7 (MK-7) and the major fatty acids were iso-C17?:?0 3-OH, iso-C15?:?0 and iso-C15?:?1 G. The G+C content of the genomic DNA was 47.5±1.0 mol%. In addition to phosphatidylethanolamine, the major polar lipids were two unidentified aminophospholipids, one unidentified aminolipid and three unidentified polar lipids. The major cell-wall sugars were ribose, xylose and galactose. It is proposed that strain DCY13(T) represents a novel species in the genus Sediminibacterium, for which the name Sediminibacterium ginsengisoli sp. nov. is proposed. The type strain is DCY13(T) (?=?KCTC 12833(T) ?=?JCM 15794(T) ?=?DSM 22335(T)). Emended descriptions of the genus Sediminibacterium and of Sediminibacterium salmoneum are also proposed. PMID:22634704

Kim, Yeon-Ju; Nguyen, Ngoc-Lan; Weon, Hang-Yeon; Yang, Deok-Chun

2013-03-01

255

Biodegradation of alachlor in liquid and soil cultures under variable carbon and nitrogen sources by bacterial consortium isolated from corn field soil  

PubMed Central

Alachlor, an aniline herbicide widely used in corn production, is frequently detected in water resources. The main objectives of this research were focused on isolating bacterial consortium capable of alachlor biodegradation, assessing the effects of carbon and nitrogen sources on alachlor biodegradation and evaluating the feasibility of using bacterial consortium in soil culture. Kavar corn field soil with a long history of alachlor application in Fars province of Iran has been explored for their potential of alachlor biodegradation. The influence of different carbon compounds (glucose, sodium citrate, sucrose, starch and the combination of these compounds), the effect of nitrogen sources (ammonium nitrate and urea) and different pH (5.5-8.5) on alachlor removal efficiency by the bacterial consortium in liquid culture were investigated. After a multi-step enrichment program 100 days of acclimation, a culture with the high capability of alachlor degradation was obtained (63%). Glucose and sodium citrate had the highest alachlor reduction rate (85%). Alachlor reduction rate increased more rapidly by the addition of ammonium nitrate (94%) compare to urea. Based on the data obtained in the present study, pH of 7.5 is optimal for alachlor biodegradation. After 30 days of incubation, the percent of alachlor reduction were significantly enhanced in the inoculated soils (74%) as compared to uninoculated control soils (17.67%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with bacterial consortium may enhance the rate of alachlor degradation in a polluted soil.

2013-01-01

256

The effect of 5-HT and electrical field stimulation on the contractility of the whole isolated urinary bladder of Suncus murinus.  

PubMed

The present study used the whole isolated urinary bladder of Suncus murinus, to investigate the effect of exogenously added serotonin (5-HT) and electrical field stimulation (EFS) in the absence and presence of methysergide, a 5-HT1/2/7 receptor antagonist or the selective 5-HT7 receptor antagonist, SB269970. Further experiments investigated the involvement of potassium channel, cholinergic and purinergic systems in mediating the contractile response to EFS. Pre-treatment with methysergide reduced and increased the contractile responses to 5-HT and EFS, respectively. Pre-treatment with SB269970 increased the responses to 5-HT without modifying the EFS-induced contractions. EFS-induced contractions were not modified by pre-treatment with atropine (10?M), ?-?-methylene ATP or glibenclamide. EFS-induced contractions were attenuated by cromakalim (10µM) or atropine (0.1 µM). In conclusion, the 5-HT2 receptors are likely to play a role in mediating the contractile response to 5-HT in detrusor muscle. Furthermore, EFS-induced contractions are mediated through cholinergic and an unknown neurotransmitter which is modulated by K(ATP) channels in the detrusor muscle of Suncus murinus. PMID:24513135

Javid, Farideh A; Palea, Stefano

2014-01-15

257

Biodegradation of alachlor in liquid and soil cultures under variable carbon and nitrogen sources by bacterial consortium isolated from corn field soil.  

PubMed

Alachlor, an aniline herbicide widely used in corn production, is frequently detected in water resources. The main objectives of this research were focused on isolating bacterial consortium capable of alachlor biodegradation, assessing the effects of carbon and nitrogen sources on alachlor biodegradation and evaluating the feasibility of using bacterial consortium in soil culture. Kavar corn field soil with a long history of alachlor application in Fars province of Iran has been explored for their potential of alachlor biodegradation. The influence of different carbon compounds (glucose, sodium citrate, sucrose, starch and the combination of these compounds), the effect of nitrogen sources (ammonium nitrate and urea) and different pH (5.5-8.5) on alachlor removal efficiency by the bacterial consortium in liquid culture were investigated. After a multi-step enrichment program 100 days of acclimation, a culture with the high capability of alachlor degradation was obtained (63%). Glucose and sodium citrate had the highest alachlor reduction rate (85%). Alachlor reduction rate increased more rapidly by the addition of ammonium nitrate (94%) compare to urea. Based on the data obtained in the present study, pH of 7.5 is optimal for alachlor biodegradation. After 30 days of incubation, the percent of alachlor reduction were significantly enhanced in the inoculated soils (74%) as compared to uninoculated control soils (17.67%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with bacterial consortium may enhance the rate of alachlor degradation in a polluted soil. PMID:23452801

Dehghani, Mansooreh; Nasseri, Simin; Zamanian, Zahra

2013-01-01

258

Comparative pulsed-field gel electrophoresis typing of gentamicin-resistant and -susceptible methicillin-resistant Staphylococcus aureus strains isolated in France between 1991 and 1998. Changes in antibiotic susceptibility.  

PubMed

Using macrorestriction of genomic DNA and pulsed-field gel electrophoresis, we examined 504 non-redundant, infection-causing human isolates of methicillin-resistant Staphylococcus aureus susceptible (G(S): 238 isolates) or resistant to gentamicin (G(R): 266 isolates). The strains were isolated at Albert Chenevier Hospital (Créteil, France) between 1 January 1991 and 31 December 1998. Their susceptibility to erythromycin, lincomycin, tetracycline, rifampicin, fusidic acid and fosfomycin was also studied. Seventy-six genotypes were identified (percentage similarity<80). Ten types, each containing at least eight strains, predominated. G(R) strains showed higher genetic polymorphism than G(S) strains: the 266 G(R) isolates belonged to 67 genotypes, five of which predominated (44, 42, 38, 30 and 15 isolates); the 238 G(S) isolates belonged to only 18 types, four of which predominated (112, 83, 11 and 10 isolates). Fifty-six percent of G(R) strains (34 Gt) were resistant to erythromycin, lincomycin, tetracycline and rifampicin, and were isolated at relatively stable frequencies. Resistance to five antibiotics studied (susceptible to fusidic acid) was observed among 16.5% of G(R) strains. The frequency of strains with this profile diminished from 30% in the early 1990s to 10% in 1998. One hundred and twenty-six G(S) isolates were susceptible to all six antibiotics; this profile was only found from 1993 onwards, and was increasingly frequent (60% of G(S) strains in 1996). Resistance to erythromycin and lincomycin only was found in 70 G(S) isolates; this profile accounted for approximately half the isolates in 1992/1993 and only one-third in 1998. These results, obtained over an eight-year period, show an overall increase in antibiotic susceptibility. They confirm the spread of two major clones of MRSA-G(S) and support the hypotheses that G(S) strains derive from G(R) strains that have lost the aac6'-aph2" gene; and that G(S) strains are genetically related to those that were present before the use of gentamicin and persisted at a low frequency until 1992-1993. PMID:12183140

Mangeney, N; Drollee, K; Cloitre, V; Bordes, M; Faubert, E; Dupeyron, C

2002-08-01

259

Terrimicrobium sacchariphilum gen. nov., sp. nov., an anaerobic bacterium of the class 'Spartobacteria' in the phylum Verrucomicrobia, isolated from a rice paddy field.  

PubMed

A strictly anaerobic, mesophilic, carbohydrate-fermenting bacterium, designated NM-5(T), was isolated from a rice paddy field. Cells of strain NM-5(T) were Gram-stain-negative, non-motile, non-spore-forming, short rods (0.5-0.7 µm×0.6-1.2 µm). The strain grew optimally at 37 °C (growth range 20-40 °C) and pH 7.0 (pH 5.5-8.0). The strain could grow fermentatively on arabinose, xylose, fructose, galactose, glucose, ribose, mannose, cellobiose, lactose, maltose and sucrose. The main end-products of glucose fermentation were acetate and propionate. Organic acids, alcohols and amino acids were not utilized for growth. Yeast extract was not required but stimulated the growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite, and Fe (III) nitrilotriacetate were not used as terminal electron acceptors. The DNA G+C content was 46.3 mol%. The major cellular fatty acids were iso-C14?:?0, C18?:?0 and C16?:?0. 16S rRNA gene sequence analysis revealed that strain NM-5(T) belongs to the class 'Spartobacteria', subdivision 2 of the bacterial phylum Verrucomicrobia. Phylogenetically, the closest species was 'Chthoniobacter flavus' (89.6?% similarity in 16S rRNA gene sequence). A novel genus and species, Terrimicrobium sacchariphilum gen. nov., sp. nov., is proposed. The type strain of the type species is NM-5(T) (?=?JCM 17479(T)?=?CGMCC 1.5168(T)). PMID:24535138

Qiu, Yan-Ling; Kuang, Xiao-Zhu; Shi, Xiao-Shuang; Yuan, Xian-Zheng; Guo, Rong-Bo

2014-05-01

260

Transmission blocking activity of Azadirachta indica and Guiera senegalensis extracts on the sporogonic development of Plasmodium falciparum field isolates in Anopheles coluzzii mosquitoes  

PubMed Central

Background Targeting the stages of the malaria parasites responsible for transmission from the human host to the mosquito vector is a key pharmacological strategy for malaria control. Research efforts to identify compounds that are active against these stages have significantly increased in recent years. However, at present, only two drugs are available, namely primaquine and artesunate, which reportedly act on late stage gametocytes. Methods In this study, we assessed the antiplasmodial effects of 5 extracts obtained from the neem tree Azadirachta indica and Guiera senegalensis against the early vector stages of Plasmodium falciparum, using field isolates. In an ex vivo assay gametocytaemic blood was supplemented with the plant extracts and offered to Anopheles coluzzii females by membrane feeding. Transmission blocking activity was evaluated by assessing oocyst prevalence and density on the mosquito midguts. Results Initial screening of the 5 plant extracts at 250 ppm revealed transmission blocking activity in two neem preparations. Up to a concentration of 70 ppm the commercial extract NeemAzal® completely blocked transmission and at 60 ppm mosquitoes of 4 out of 5 replicate groups remained uninfected. Mosquitoes fed on the ethyl acetate phase of neem leaves at 250 ppm showed a reduction in oocyst prevalence of 59.0% (CI95 12.0 - 79.0; p?

2014-01-01

261

Solibius ginsengiterrae gen. nov., sp. nov., isolated from soil of a ginseng field, and emended description of the genus Sediminibacterium and of Sediminibacterium salmoneium.  

PubMed

A novel Gram-staining-negative bacterial strain, designated DCY13T, was isolated from soil of a ginseng field in Korea and characterized by using a polyphasic approach. The phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DCY13T forms a cluster with members of the genera Sediminibacterium, Flavisolibacter, Niabella, Terrimonas, Niastella and Chitinophaga in the family 'Chitinophagaceae', phylum Bacteroidetes, and shares highest sequence similarity (95.2 %) with Sediminibacterium salmoneum NJ-44T. Sequence similarity with other members of the family is 87.6-91.4 %. Cells are non-spore-forming rods, catalase and oxidase-positive, motile by gliding that grow under strictly aerobic conditions. The predominant respiratory quinone is menaquinone MK-7, and the major fatty acids are anteiso-C15:0, iso C16:0, anteiso-C17:0, and iso-C15:0. The G+C content of the genomic DNA is 47.8 mol%. The major cell wall amino acids are D-aspartic acid, D-glycine, D-serine, L-lysine, D-glucosamine, and D-alanine. The major cell wall sugars are ribose, xylose, and galactose. The major polar lipids are phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. It is proposed that strain DCY13T represents a novel genus and species in the family 'Chitinophagaceae' for which the name Solibius ginsengiterrae gen. nov., sp. nov., is proposed. The type strain is DCY13T (= KCTC 12833T = JCM 15794T). Emended descriptions of the genus Sediminibacterium and of S. salmoneum NJ44T are also proposed. PMID:20061500

Kim, Yeon-Ju; Kim, Myung Kyum; Bui, Thi Phuong Nam; Kim, Ho-Bin; Srinivasan, Sathiyaraj; Yang, Deok-Chun

2010-12-01

262

S1 gene characteristics and efficacy of vaccination against infectious bronchitis virus field isolates from the United States and Israel (1996 to 2000)  

Microsoft Academic Search

The S1 genes of isolates of avian coronavirus infectious bronchitis virus (IBV) from commercial chickens in the US and Israel (20 isolates from each country) were studied using reverse transcription-polymerase chain reaction restriction fragment length polymorphism and sequencing. Partial sequences spanning the amino terminus region of S1 from amino acid residues 48 to 219, based on the Beaudette strain, were

J. Gelb Jr; Y. Weisman; B. S. Ladman; R. Meir

2005-01-01

263

Isolated systems in general relativity  

Microsoft Academic Search

Isolated systems in General Relativity were studied. Radiation effects on composite isolated systems are examined. The non-linear asymptotic vacuum field equations were solved in the formalism of Newman and Penrose. A Spin Weight Spherical Harmonics representation of the source was used. The concept of angular momentum is examined for isolated systems in General Relativity. It is argued that, on physical

A. Cresswell

1984-01-01

264

An ELISA optimized for porcine epidemic diarrhoea virus detection in faeces.  

PubMed

Monoclonal antibodies to porcine epidemic diarrhoea virus (PEDV) membrane protein M were prepared and used for the comparative assessment of three blocking ELISA variants to detect PEDV. The competitive blocking ELISA (CB-ELISA) format showed the highest sensitivity, allowing detection of 10(2.5) plaque-forming units of PEDV/ml in culture medium. Its specificity was verified by inclusion of control samples containing transmissible gastroenteritis virus (TGEV) and rotavirus A in each analysis. Eighty porcine field samples of faeces obtained from 38 herds affected with diarrhoea were examined, and PEDV was found in 15 (19%) samples from 6 (16%) herds. The suitability of the CB-ELISA for the screening herds in epizootiologic situations is discussed. PMID:15607079

Rodák, L; Valícek, L; Smíd, B; Nevoránková, Z

2005-01-01

265

SYMBIODINIUM ISOLATES FROM STONY CORAL: ISOLATION, GROWTH CHARACTERISTICS AND EFFECTS OF UV IRRADIATION  

EPA Science Inventory

Symbiodinium spp. Isolates from Stony Coral: Isolation, Growth Characteristics and Effects of UV Irradiation (Abstract). J. Phycol. 37(3):42-43. Symbiodinium species were isolated from Montipora capitata, Acropora palmata and two field samples of Porites porites. Cultures ...

266

Thiofractor thiocaminus gen. nov., sp. nov., a novel hydrogen-oxidizing, sulfur-reducing epsilonproteobacterium isolated from a deep-sea hydrothermal vent chimney in the Nikko Seamount field of the northern Mariana Arc.  

PubMed

A novel chemolithoautotrophic hydrogen-oxidizing and sulfur-reducing bacterium, strain 496Chim(T), was isolated from a deep-sea hydrothermal vent chimney collected from the hydrothermal field at the summit of Nikko Seamount field, in the Mariana Arc. Cells were rods or curved rods, motile by means of a single polar flagellum. Growth was observed between 15 and 45 °C (optimum 37 °C; doubling time, 2.1 h) and between pH 5.3 and 8.0 (optimum pH 6.0). The isolate was a strictly anaerobic, obligate chemolithoautotroph capable of growth using molecular hydrogen as the sole energy source, carbon dioxide as the sole carbon source, ammonium or nitrate as the sole nitrogen source, and elemental sulfur as the electron acceptor. The G+C content of genomic DNA was 35 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the new isolate belonged to the class Epsilonproteobacteria, but the isolate was distantly related to the previously described Epsilonproteobacteria species potentially at the genus level (<90 %). On the basis of its physiological and molecular characteristics, strain 496Chim(T) (=DSM 22050(?) = JCM 15747(?) = NBRC 105224(?)) represents the sole species of a new genus, Thiofractor, for which the name Thiofractor thiocaminus is proposed. PMID:22526267

Makita, Hiroko; Nakagawa, Satoshi; Miyazaki, Masayuki; Nakamura, Ko-ichi; Inagaki, Fumio; Takai, Ken

2012-09-01

267

Polymorphic Amplified Typing Sequences and Pulsed-Field Gel Electrophoresis Yield Comparable Results in the Strain Typing of a Diverse Set of Bovine Escherichia coli O157:H7 Isolates  

PubMed Central

Polymorphic amplified typing sequences (PATS), a PCR-based Escherichia coli O157:H7 (O157) strain typing system, targets insertions-deletions and single nucleotide polymorphisms at XbaI and AvrII restriction enzyme sites, respectively, and the virulence genes (stx1, stx2, eae, hlyA) in the O157 genome. In this study, the ability of PATS to discriminate O157 isolates associated with cattle was evaluated. An in-depth comparison of 25 bovine O157 isolates, from different geographic locations across Northwest United States, showed that about 85% of these isolates shared the same dendogram clade by PATS and pulsed-field gel electrophoresis (PFGE), irrespective of the restriction enzyme sites targeted. The Pearson's correlation coefficient, r, calculated at about 0.4, 0.3, and 0.4 for XbaI-based, AvrII-based and combined-enzymes PATS and PFGE similarities, respectively, indicating that these profiles shared a good but not high correlation, an expected inference given that the two techniques discriminate differently. Isolates that grouped differently were better matched to their locations using PATS. Overall, PATS discriminated the bovine O157 isolates without interpretive biases or sophisticated analytical software, and effectively complemented while not duplicating PFGE. With its quick turnaround time, PATS has excellent potential as a convenient tool for early epidemiological or food safety investigations, enabling rapid notification/implementation of quarantine measures.

Kudva, Indira T.; Davis, Margaret A.; Griffin, Robert W.; Garren, Jeonifer; Murray, Megan; John, Manohar; Hovde, Carolyn J.; Calderwood, Stephen B.

2012-01-01

268

Epidemiological Typing of Isolates from an Outbreak of Infection with Multidrug-ResistantEnterobacter cloacaeby Repetitive Extragenic Palindromic Unit b1-Primed PCR and Pulsed-Field Gel Electrophoresis  

Microsoft Academic Search

An outbreak of multidrug-resistantEnterobacter cloacaeinfection lasted for 4 months in a neonatal intensive care unit (NICU). Forty-six isolates from the NICU and 20 epidemiologically unrelated strains were charac- terized by pulsed-field gel electrophoresis (PFGE) and repetitive extragenic palindromic unit b1-primed PCR (REPUb1-PCR) typing. The PFGE patterns after XbaI restriction of the bacterial DNA were analyzed by computer software (Gelcompar) using

ZHI-YUAN SHI; PETER YUK-FONG LIU; YEU-JUN LAU; YU-HUI LIN; ANDBOR-SHEN HU

1996-01-01

269

Isolation precautions  

MedlinePLUS

Isolation precautions create barriers between people and germs. These types of precautions help prevent the spread of germs in the hospital. Anybody who visits a hospital patient who has an isolation ...

270

Vibration isolation  

NASA Technical Reports Server (NTRS)

Viewgraphs on vibration isolation are presented. Techniques to control and isolate centrifuge disturbances were identified. Topics covered include: disturbance sources in the microgravity environment; microgravity assessment criteria; life sciences centrifuge; flight support equipment for launch; active vibration isolation system; active balancing system; and fuzzy logic control.

Bastin, Paul

1990-01-01

271

Effects of macroscopic propagation on spectra of broadband supercontinuum harmonics and isolated-attosecond-pulse generation: Coherent control of the electron quantum trajectories in two-color laser fields  

NASA Astrophysics Data System (ADS)

Recently it was shown that broadband supercontinuum harmonics can be produced from the long-trajectory electrons in the single-atom response by the coherent control of the electron trajectories through optimized two-color laser fields. Such supercontinuum harmonics can be superposed to generate an isolated sub-30-attosecond (as) pulse [Liu , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.033414 84, 033414 (2011)]. In this paper, we investigate the effect of macroscopic propagation on the supercontinuum harmonic spectra and the subsequent attosecond-pulse generation of atomic hydrogen. The time-dependent Schrödinger equation is solved accurately and efficiently by means of the time-dependent generalized pseudospectral method. The effects of macroscopic propagation are investigated in near and far field by solving Maxwell's equation. The results show that the contribution of short-trajectory electron emission is increased when the macroscopic propagation is considered. However, the characteristics of the dominant long-trajectory electron emission (in the single-atom response case) are not changed, and an isolated 53 as pulse can be generated in the near field. Moreover, in the far field, the contribution of long-trajectory electron emission is still dominant for both on-axis and off-axis cases. As a result, an isolated 42 as pulse can be generated directly. Similar results are obtained when the atomic target position is changed. Therefore, the proposed method for the single ultrashort attosecond-pulse generation can be realized by means of the coherent control of the electron quantum paths in appropriately optimized two-color laser fields.

Li, Peng-Cheng; Chu, Shih-I.

2012-07-01

272

Isolation and purification of an axenic diazotrophic drought-tolerant cyanobacterium, Nostoc commune, from natural cyanobacterial crusts and its utilization for field research on soils polluted with radioisotopes.  

PubMed

Nitrogen fixation and drought tolerance confer the ability to grow on dry land, and some terrestrial cyanobacteria exhibit these properties. These cyanobacteria were isolated in an axenic form from Nostoc commune clusters and other sources by modifying the method used to isolate the nitrogen-fixing and drought-tolerant cyanobacterium Nostoc sp. HK-01. Of these cyanobacteria, N. commune, which is difficult to isolate and purify, uses polysaccharides to maintain water, nitrogen fertilizers for nitrogen fixation, and can live in extreme environments because of desiccation tolerance. In this study, we examined the use of N. commune as biosoil for space agriculture and possible absorption of radioisotopes ((134)Cs, (137)Cs). This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial. PMID:22417797

Katoh, Hiroshi; Furukawa, Jun; Tomita-Yokotani, Kaori; Nishi, Yasuaki

2012-08-01

273

Isolations of Jamestown Canyon virus (Bunyaviridae: Orthobunyavirus) from field-collected mosquitoes (Diptera: Culicidae) in Connecticut, USA: a ten-year analysis, 1997-2006.  

PubMed

Jamestown Canyon virus (JCV) (Bunyaviridae: Orthobunyavirus) is a mosquito-borne zoonosis belonging to the California serogroup. It has a wide geographic distribution, occurring throughout much of temperate North America. White-tailed deer, Odocoileus virginianus are the principal amplification hosts, and boreal Aedes and Ochlerotatus mosquitoes are the primary vectors. A 10-year study was undertaken to identify potential mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the geographic distribution of JCV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. Jamestown Canyon virus was isolated from 22 mosquito species. Five of them, Ochlerotatus canadensis, Oc. cantator, Anopheles punctipennis, Coquillettidia perturbans, and Oc. abserratus were incriminated as the most likely vectors, based on yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Jamestown Canyon virus was isolated from Oc. canadensis more consistently and from a greater range of collection sites than any other species. Frequent virus isolations were also made from Aedes cinereus, Aedes vexans, and Oc. sticticus, and new North American isolation records were established for Anopheles walkeri, Culex restuans, Culiseta morsitans, Oc. sticticus, Oc. taeniorhynchus, and Psorophora ferox. Other species from which JCV was isolated included C. melanura, Oc. aurifer, Oc. communis, Oc. excrucians, Oc. provocans, Oc. sollicitans, Oc. stimulans, Oc. triseriatus, and Oc. trivittatus. Jamestown Canyon virus was widely distributed throughout Connecticut and found to consistently circulate in a diverse array of mosquito vectors. Infected mosquitoes were collected from June through September, and peak infection rates paralleled mosquito abundance from mid-June through mid-July. Infection rates in mosquitoes were consistent from year to year, and overall virus activity was directly related to local mosquito abundance. Infected mosquitoes were equally distributed throughout the state, irrespective of land use, and infection rates were not directly associated with the abundance of white-tailed deer, possibly because of their saturation throughout the region. PMID:18386967

Andreadis, Theodore G; Anderson, John F; Armstrong, Philip M; Main, Andrew J

2008-04-01

274

Pathogenicity of entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana (Hypocreales: Clavicipitaceae) isolates to the adult pea leafminer (Diptera: Agromyzidae) and prospects of an autoinoculation device for infection in the field.  

PubMed

Seventeen isolates of Metarhizium anisopliae (Metschnikoff) Sorokin and three isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) were evaluated for their pathogenicity to the adult pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae), in the laboratory. Flies were contaminated with dry conidia through a velvet material wrapped around the inner side of a cylindrical plastic tube. All the isolates were pathogenic to the pea leafminer, causing mortality between 40 and 100% at 5 d after exposure. The lethal time for 50% mortality (LT(50)) ranged from 2.6 to 5.4 d, whereas the LT(90) values varied between 3.2 and 9.1 d depending on the isolate. An autoinoculation device was evaluated in cage field experiments using only one of the virulent isolates, M. anisopliae ICIPE 20. The device was loaded with 2-3 g of dry conidia. Mortality of up to 100% was observed in flies captured from fungus-treated cages held under laboratory conditions. The average number of spores picked up by a single fly visiting the device increased with days after inoculation. One day after the inoculation, adults picked up an average of 4.1 +/- 0.7 x 10(5) conidia and 39.6 +/- 4.0 x 10(5) conidia 5 d after inoculation. Depending on the sampling date, the LT(50) varied between 1.8 and 3.4 d. Results indicate that some isolates of B. bassiana and M. anisopliae are highly pathogenic to L. huidobrensis, suggesting a potential for their use in the control of this pest. They also suggest the possibility of L. huidobrensis suppression with fungi using an autoinoculation device. PMID:20388276

Migiro, L N; Maniania, N K; Chabi-Olaye, A; Vandenberg, J

2010-04-01

275

Benchmark database on isolated small peptides containing an aromatic side chain: comparison between wave function and density functional theory methods and empirical force field  

Microsoft Academic Search

A detailed quantum chemical study on five peptides (WG, WGG, FGG, GGF and GFA) containing the residues phenylalanyl (F), glycyl (G), tryptophyl (W) and alanyl (A)where F and W are of aromatic characteris presented. When investigating isolated small peptides, the dispersion interaction is the dominant attractive force in the peptide backbonearomatic side chain intramolecular interaction. Consequently, an accurate theoretical study

Haydee Valdes; Kristýna Pluhácková; Michal Pitonák; Jan Rezác; Pavel Hobza

2008-01-01

276

Genetic and phenotypic characterization of a 2006 United States porcine reproductive and respiratory virus isolate associated with high morbidity and mortality in the field.  

PubMed

The objective of this study was to characterize a porcine reproductive and respiratory syndrome virus (PRRSV) isolated from United States pigs experiencing high morbidity (50%) and mortality (20%). The PRRSV isolate, designated NC16845b, was characterized through phenotypic analysis and genomic sequencing and compared to Type 2 PRRSV isolates VR-2332, MN184 and VR-2385. NC16845b demonstrated slower replication in vitro compared to the three other isolates and grew to a peak titer of 5.4×10(5) plaque forming units (PFU) per ml at 60 h post inoculation, which was 4- to 13-fold less than the peak titer of the other three viruses. NC16845b plaques were intermediate size averaging 3.3mm in diameter that was larger than MN184 plaques and smaller than VR-2385 and VR-2332. Using Northern blot analysis, viral and subgenomic RNA were detected that demonstrated variable levels of hybridization in some open reading frames (ORF) compared to the other viruses. NC16845b is 15,389 nucleotides in length and ORF 5 restriction fragment length polymorphism (RFLP) analysis demonstrated a 1-18-2 pattern. Among all available Type 2 complete genome sequences, NC16845b showed the highest nucleotide homology (91.2%) to atypical PRRSV strain JA142. Compared to prototype VR-2332, NC16845b demonstrated marked nucleotide variability within non-structural protein (nsp) 1? and nsp2, and a nucleotide deletion of 24 bases in nsp2. Sequence homology with VR-2332 and MN184 was 88.4% and 82.9%, respectively; homology with the ORF2-7 of VR-2385 was 90.4%. Collectively, these data indicate that, compared to prototype Type 2 PRRSV isolates, NC16845b exhibited slower in vitro growth properties, had regions of heterogeneity within ORF1a that corresponded to at least two individual virus quasispecies, and also contained a continuous 8 amino acid deletion in the nsp2 protein. PMID:21920393

Gauger, Phillip C; Faaberg, Kay S; Guo, Baoqing; Kappes, Matthew A; Opriessnig, Tanja

2012-01-01

277

EKG isolator  

NASA Technical Reports Server (NTRS)

Light beam transmits heartbeat signal from electrodes on patient to electrocardiograph without exposing patient to possible severe electrical shock. System provides complete isolation between patient and EKG instrumentation.

Palmer, E.; Rasquin, J. R.; Smith, H. E.

1971-01-01

278

Isolation of cDNA clones for genes showing enhanced expression in barley leaves during dark-induced senescence as well as during senescence under field conditions  

Microsoft Academic Search

.   Senescence of barley (Hordeum vulgare L. cv. Carina) primary foliage leaves was induced by transfer of the plants into darkness for 2?d. Under these conditions\\u000a senescence was characterized by a light-reversible decline in the efficiency of photosystem II, and in chlorophyll and protein\\u000a contents. To isolate senescence-associated genes a differential display of cDNA fragments amplified from reversely transcribed\\u000a RNA

Tamara Kleber-Janke; Karin Krupinska

1997-01-01

279

Serotype distribution and production of muramidase-released protein, extracellular factor and suilysin by field strains of Streptococcus suis isolated in the United States.  

PubMed

Streptococcus suis is an important swine pathogen and a zoonotic agent. Differences in virulence have been noted among the 33 described serotypes, serotype 2 being considered the most virulent. In this study, we aimed at assessing the serotype distribution and the production of virulence-associated markers by strains recovered from diseased pigs in the United States (U.S.). Results showed that among the 100 strains evaluated, serotype 3 (20% of the isolates) and serotype 2 (17%) were the most prevalent. We then investigated the presence in these isolates of the genes sly, epf and mrp, encoding the virulence-associated markers suilysin (SLY), extracellular factor (EF) and muramidase-released (MRP) protein, respectively. The effective production of the markers by the strains was also verified. Results showed that the presence of the gene did not always correlate with actual expression of the respective protein. In the case of MRP, this was due, in most cases, to frameshift mutations at the 5' end of the gene resulting in premature stop codons. The most prevalent phenotypes among U.S. strains were MRP(+)EF(-)SLY(-) (40%) and MRP(-)EF(-)SLY(+) (35%). Serotype distribution greatly differed from that reported in several European countries, as did the production of virulence markers, particularly for serotype 2. On the other hand, our results for the U.S. S. suis isolates are similar to those reported for Canadian strains, suggesting a common status in North America. PMID:19596529

Fittipaldi, Nahuel; Fuller, Troy E; Teel, Janet F; Wilson, Thomas L; Wolfram, Thaddeus J; Lowery, David E; Gottschalk, Marcelo

2009-11-18

280

[Use of multilocus sequence typing and pulsed-field gel electrophoresis for the study of serogroup B Neisseria meningitidis isolates from Casablanca (Morocco)].  

PubMed

A previous study showed that B:4:P1.15 was the most frequent phenotype of Neisseria meningitidis isolated in Casablanca (Morocco). To determine if there was an epidemic clone, MLST and PFGE were used to compare 13 B:4:P1.15 strains isolated from September 1999 to December 2000. MLST showed 4 Sequence Types (ST): ST-33 was the most frequent ST (9/13 strains) and 4 strains belonged to 3 newly described STs. Twelve stains belonged to ST-32 complex, and one strain presenting a new ST (ST-2502) did not belong to any known ST complex. The analysis by PFGE showed that the strains were subdivided into 7 clusters, and that there was no epidemic clone. MLST is useful for long-term epidemiological studies on N. meningitidis strains from varied geographical origins. PFGE seemed to be well adapted to the comparison of a small number of strains isolated during a short period within a defined community. PMID:16442242

Zerouali, K; Castelli, P; Van Looveren, M; El Mdaghri, N; Boudouma, M; Benbachir, M; Nicolas, P

2006-04-01

281

Detection by Reverse Transcription-PCR and Genetic Characterization of Field Isolates of Swine Hepatitis E Virus from Pigs in Different Geographic Regions of the United States  

PubMed Central

Hepatitis E virus (HEV) is an important public health concern in many developing countries. HEV is also endemic in some industrialized counties, including the United States. With our recent discovery of swine HEV in pigs that is genetically closely related to human HEV, hepatitis E is now considered a zoonotic disease. Human strains of HEV are genetically heterogenic. So far in the United States, only one strain of swine HEV has been identified and characterized from a pig. To determine the extent of genetic variations and the nature of swine HEV infections in U.S. pigs, we developed a universal reverse transcription-PCR (RT-PCR) assay that is capable of detecting genetically divergent strains of HEV. By using this universal RT-PCR assay, we tested fecal and serum samples of pigs of 2 to 4 months of age from 37 different U.S. swine farms for the presence of swine HEV RNA. Thirty-four of the 96 pigs (35%) and 20 of the 37 swine herds (54%) tested were positive for swine HEV RNA. The sequences of a 348-bp region within the ORF2 gene of 27 swine HEV isolates from different geographic regions were determined. Sequence analyses revealed that the 27 U.S. swine HEV isolates shared 88 to 100% nucleotide sequence identities with each other and 89 to 98% identities with the prototype U.S. strain of swine HEV. These U.S. swine HEV isolates are only distantly related to the Taiwanese strains of swine HEV, with about 74 to 78% nucleotide sequence identities; to most known human strains of HEV worldwide, with <79% sequence identities; and to avian HEV, with 54 to 56% sequence identities. Phylogenetic analysis showed that all the U.S. swine HEV isolates identified in this study clustered in the same genotype with the prototype U.S. swine HEV and the two U.S. strains of human HEV. The data from this study indicated that swine HEV is widespread and enzoonotic in U.S. swine herds and that, as is with human HEV, swine HEV isolates from different geographic regions of the world are also genetically heterogenic. These data further raise potential concerns for zoonosis, xenozoonosis, and food safety.

Huang, F. F.; Haqshenas, G.; Guenette, D. K.; Halbur, P. G.; Schommer, S. K.; Pierson, F. W.; Toth, T.E.; Meng, X. J.

2002-01-01

282

Determination of selected pesticides in water samples adjacent to agricultural fields and removal of organophosphorus insecticide chlorpyrifos using soil bacterial isolates  

NASA Astrophysics Data System (ADS)

The use of pesticide for crops leads to serious environmental pollution, therefore, it is essential to monitor and develop approaches to remove pesticide from contaminated environment. In this study, water samples were collected to monitor pesticide residues, and degradation of chlorpyrifos was also performed using soil bacteria. Identification of pesticide residues and determination of their levels were performed by high-performance liquid chromatography with photodiode array detector. Among 12 samples, 10 samples were found contaminated with pesticides. Chlorpyrifos was detected in four tested samples and concentrations ranged from 3.27 to 9.31 ?g/l whereas fenitrothion ranging from (Below Detection Limit, <0.1 ?g/l) to 33.41 ?g/l in the tested samples. Parathion was found in two tested samples at the concentration of 0.73 and 6.23 ?g/l. None of the tested samples was found contaminated with Methoxychlor, DDT and Ethion. Three soil bacterial isolates, Pseudomonas peli BG1, Burkholderia caryophylli BG4 and Brevundimonas diminuta PD6 degraded chlorpyrifos completely in 8, 10 and 10 days, respectively, when 20 mg/l chlorpyrifos was supplied as sole source of carbon. Whereas, BG1, BG4 and PD6 took 14, 16 and 16 days, respectively, for complete removal of 50 mg/l chlorpyrifos. Chlorpyrifos degradation rates were found maximum by all three isolates at 2nd day of incubation for both tested concentrations. The results of the present study suggest the need for regular monitoring of pesticide residues in water, to protect the aquatic environment. Chlorpyrifos degrading bacterial isolates can be used to clean up environmental samples contaminated with the organophosphate pesticides.

Hossain, M. S.; Chowdhury, M. Alamgir Zaman; Pramanik, Md. Kamruzzaman; Rahman, M. A.; Fakhruddin, A. N. M.; Alam, M. Khorshed

2014-03-01

283

Candidate isolated neutron stars and other optically blank x-ray fields identified from the rosat all-sky and sloan digital sky surveys  

SciTech Connect

Only seven radio-quiet isolated neutron stars (INSs) emitting thermal X rays are known, a sample that has yet to definitively address such fundamental issues as the equation of state of degenerate neutron matter. We describe a selection algorithm based on a cross-correlation of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) that identifies X-ray error circles devoid of plausible optical counterparts to the SDSS g {approx} 22 magnitudes limit. We quantitatively characterize these error circles as optically blank; they may host INSs or other similarly exotic X-ray sources such as radio-quiet BL Lacs, obscured AGN, etc. Our search is an order of magnitude more selective than previous searches for optically blank RASS error circles, and excludes the 99.9% of error circles that contain more common X-ray-emitting subclasses. We find 11 candidates, nine of which are new. While our search is designed to find the best INS candidates and not to produce a complete list of INSs in the RASS, it is reassuring that our number of candidates is consistent with predictions from INS population models. Further X-ray observations will obtain pinpoint positions and determine whether these sources are entirely optically blank at g {approx} 22, supporting the presence of likely isolated neutron stars and perhaps enabling detailed follow-up studies of neutron star physics.

Agueros, Marcel A.; Anderson, Scott F.; /Washington U., Seattle, Astron. Dept.; Margon, Bruce; /Baltimore, Space Telescope Sci.; Haberl, Frank; Voges, Wolfgang; /Garching, Max Planck Inst., MPE; Annis, James; /Fermilab; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Brinkmann, Jonathan; /Apache Point Observ.

2005-11-01

284

Genetic Diversity of Food-Isolated Salmonella Strains through Pulsed Field Gel Electrophoresis (PFGE) and Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR)  

PubMed Central

All over the world, the incidence of Salmonella spp contamination on different food sources like broilers, clams and cow milk has increased rapidly in recent years. The multifaceted properties of Salomnella serovars allow the microorganism to grow and multiply in various food matrices, even under adverse conditions. Therefore, methods are needed to detect and trace this pathogen along the entire food supply network. In the present work, PFGE and ERIC-PCR were used to subtype 45 Salmonella isolates belonging to different serovars and derived from different food origins. Among these isolates, S. Enteritidis and S. Kentucky were found to be the most predominant serovars. The Discrimination Index obtained by ERIC-PCR (0.85) was slightly below the acceptable confidence value. The best discriminatory ability was observed when PFGE typing method was used alone (DI?=?0.94) or combined with ERIC-PCR (DI?=?0.93). A wide variety of profiles was observed between the different serovars using PFGE or/and ERIC-PCR. This diversity is particularly important when the sample origins are varied and even within the same sampling origin.

Fendri, Imen; Ben Hassena, Amal; Grosset, Noel; Barkallah, Mohamed; Khannous, Lamia; Chuat, Victoria; Gautier, Michel; Gdoura, Radhouane

2013-01-01

285

Radioactive waste isolation in salt: geochemistry of brine in rock salt in temperature gradients and gamma-radiation fields - a selective annotated bibliography  

SciTech Connect

Evaluation of the extensive research concerning brine geochemistry and transport is critically important to successful exploitation of a salt formation for isolating high-level radioactive waste. This annotated bibliography has been compiled from documents considered to provide classic background material on the interactions between brine and rock salt, as well as the most important results from more recent research. Each summary elucidates the information or data most pertinent to situations encountered in siting, constructing, and operating a mined repository in salt for high-level radioactive waste. The research topics covered include the basic geology, depositional environment, mineralogy, and structure of evaporite and domal salts, as well as fluid inclusions, brine chemistry, thermal and gamma-radiation effects, radionuclide migration, and thermodynamic properties of salts and brines. 4 figs., 6 tabs.

Hull, A.B.; Williams, L.B.

1985-07-01

286

Correlation of SfiI macrorestriction endonuclease fingerprint analysis of Candida parapsilosis isolates with source of isolation  

Microsoft Academic Search

Sfi I macrorestriction digests from whole chromosome DNA preparations of 46 isolates of Candida parapsilosis from vaginal (20 isolates), blood (23 isolates) and soil (three isolates) sources were examined by CHEF-MAPPER pulsed-field electrophoresis. The isolates were grouped into nine macrorestriction endonuclease fingerprint (MEF) classes according to the number or size of the macrorestriction fragments, or both. The electrophoretic karyotype (EK)

E. Pontieri; L. Gregori; M. Gennarelli; T. Ceddia; B. Dallapiccola; F. De Bernardis; G. Carruba

1996-01-01

287

Binding Site Alteration Is Responsible for Field-Isolated Resistance to Bacillus thuringiensis Cry2A Insecticidal Proteins in Two Helicoverpa Species  

PubMed Central

Background Evolution of resistance by target pests is the main threat to the long-term efficacy of crops expressing Bacillus thuringiensis (Bt) insecticidal proteins. Cry2 proteins play a pivotal role in current Bt spray formulations and transgenic crops and they complement Cry1A proteins because of their different mode of action. Their presence is critical in the control of those lepidopteran species, such as Helicoverpa spp., which are not highly susceptible to Cry1A proteins. In Australia, a transgenic variety of cotton expressing Cry1Ac and Cry2Ab (Bollgard II) comprises at least 80% of the total cotton area. Prior to the widespread adoption of Bollgard II, the frequency of alleles conferring resistance to Cry2Ab in field populations of Helicoverpa armigera and Helicoverpa punctigera was significantly higher than anticipated. Colonies established from survivors of F2 screens against Cry2Ab are highly resistant to this toxin, but susceptible to Cry1Ac. Methodology/Principal Findings Bioassays performed with surface-treated artificial diet on neonates of H. armigera and H. punctigera showed that Cry2Ab resistant insects were cross-resistant to Cry2Ae while susceptible to Cry1Ab. Binding analyses with 125I-labeled Cry2Ab were performed with brush border membrane vesicles from midguts of Cry2Ab susceptible and resistant insects. The results of the binding analyses correlated with bioassay data and demonstrated that resistant insects exhibited greatly reduced binding of Cry2Ab toxin to midgut receptors, whereas no change in 125I-labeled-Cry1Ac binding was detected. As previously demonstrated for H. armigera, Cry2Ab binding sites in H. punctigera were shown to be shared by Cry2Ae, which explains why an alteration of the shared binding site would lead to cross-resistance between the two Cry2A toxins. Conclusion/Significance This is the first time that a mechanism of resistance to the Cry2 class of insecticidal proteins has been reported. Because we found the same mechanism of resistance in multiple strains representing several field populations, we conclude that target site alteration is the most likely means that field populations evolve resistance to Cry2 proteins in Helicoverpa spp. Our work also confirms the presence in the insect midgut of specific binding sites for this class of proteins. Characterizing the Cry2 receptors and their mutations that enable resistance could lead to the development of molecular tools to monitor resistance in the field.

Caccia, Silvia; Hernandez-Rodriguez, Carmen Sara; Mahon, Rod J.; Downes, Sharon; James, William; Bautsoens, Nadine; Van Rie, Jeroen; Ferre, Juan

2010-01-01

288

Flooded area and plant zonation in isolated wetlands in well fields in the Northern Tampa Bay Region, Florida, following reductions in groundwater-withdrawal rates  

USGS Publications Warehouse

Four other well-field wetlands (W-41, Q-1, Starkey D, and Starkey E) were mostly dry before reductions in groundwater-withdrawal rates and remained mostly dry after the reductions. W-41 was dry 23 percent less time in the post-reduction period, but most of the increase in flooded area was confined to less than 20 percent of the total wetland area. Q-1 was dry for only 12 percent less time in the post-reduction period. The median elevation of the potentiometric surface of the Upper Floridan aquifer increased beneath W-41 by about 5 feet and beneath Q-1 by about 2 feet after reductions in groundwater-withdrawal rates. The extent and duration of the flooded area was unchanged at Starkey D when the post-reduction period was compared to the pre-reduction period. At Starkey E the extent of the flooded area decreased slightly during the post-reduction period.

Haag, Kim H.; Pfeiffer, William R.

2012-01-01

289

Mirincamycin, an old candidate for malaria combination treatment and prophylaxis in the 21st century: in vitro interaction profiles with potential partner drugs in continuous culture and field isolates  

PubMed Central

Background Spreading resistance of Plasmodium falciparum to existing drugs calls for the search for novel anti-malarial drugs and combinations for the treatment of falciparum malaria. Methods In vitro and ex vivo investigations were conducted with fresh P. falciparum field isolates and culture-adapted P. falciparum clones to evaluate the anti-malarial potential of mirincamycin, a lincosamide, alone and in combination with tafenoquine (TQ), dihydroartemisinin (DHA), and chloroquine (CQ). All samples were tested in a histidine-rich protein 2 (HRP2) drug susceptibility assay. Results Interaction analysis showed additive to synergistic interaction profiles with these potential partner drugs, with an overall geometric mean fractional inhibitory concentration at 50% inhibition (FIC50) of 0.78, 0.80 and 0.80 for mirincamycin with TQ, DHA, and CQ, respectively. Antagonism was not found in any of the tested field isolates or clones. The strongest tendency toward synergy (i.e. the lowest FIC) was seen with a combination ratio of 1:0.27 to 1:7.2 (mean 1:2.7) for the combination with tafenoquine. The optimal combination ratios for DHA and CQ were 1:444.4 to 1:36,000 (mean 1:10,755.5) and 1:2.7 to 1:216 (mean 1:64.5), respectively. No evidence of an activity correlation (i.e. potential cross-resistance) with DHA, mefloquine, quinine or chloroquine was seen whereas a significant correlation with the activity of clindamycin and azithromycin was detected. Conclusions Mirincamycin combinations may be promising candidates for further clinical investigations in the therapy and prophylaxis of multidrug-resistant falciparum malaria or in combination with 4 or 8-aminoquinolines for the treatment and relapse prevention of vivax malaria.

2014-01-01

290

Isolation of a wheat (Triticum aestivum L.) mutant in ABA 8?-hydroxylase gene: effect of reduced ABA catabolism on germination inhibition under field condition  

PubMed Central

Pre-harvest sprouting, the germination of mature seeds on the mother plant under moist condition, is a serious problem in cereals. To investigate the effect of reduced abscisic acid (ABA) catabolism on germination in hexaploid wheat (Triticum aestivum L.), we cloned the wheat ABA 8?-hydroxyase gene which was highly expressed during seed development (TaABA8?OH1) and screened for mutations that lead to reduced ABA catabolism. In a screen for natural variation, one insertion mutation in exon 5 of TaABA8?OH1 on the D genome (TaABA8?OH1-D) was identified in Japanese cultivars including ‘Tamaizumi’. However, a single mutation in TaABA8?OH1-D had no clear effect on germination inhibition in double haploid lines. In a screen for a mutation, one deletion mutant lacking the entire TaABA8?OH1 on the A genome (TaABA8?OH1-A), TM1833, was identified from gamma-ray irradiation lines of ‘Tamaizumi’. TM1833 (a double mutant in TaABA8?OH1-A and TaABA8?OH1-D) showed lower TaABA8?OH1 expression, higher ABA content in embryos during seed development under field condition and lower germination than those in ‘Tamaizumi’ (a single mutant in TaABA8?OH1-D). These results indicate that reduced ABA catabolism through mutations in TaABA8?OH1 may be effective in germination inhibition in field-grown wheat.

Chono, Makiko; Matsunaka, Hitoshi; Seki, Masako; Fujita, Masaya; Kiribuchi-Otobe, Chikako; Oda, Shunsuke; Kojima, Hisayo; Kobayashi, Daisuke; Kawakami, Naoto

2013-01-01

291

Ex vivo anti-malarial drugs sensitivity profile of Plasmodium falciparum field isolates from Burkina Faso five years after the national policy change  

PubMed Central

Background The recent reports on the decreasing susceptibility of Plasmodium falciparum to artemisinin derivatives along the Thailand and Myanmar border are worrying. Indeed it may spread to India and then Africa, repeating the same pattern observed for chloroquine resistance. Therefore, it is essential to start monitoring P. falciparum sensitivity to artemisinin derivatives and its partner drugs in Africa. Efficacy of AL and ASAQ were tested by carrying out an in vivo drug efficacy test, with an ex vivo study against six anti-malarial drugs nested into it. Results of the latter are reported here. Methods Plasmodium falciparum ex-vivo susceptibility to chloroquine (CQ), quinine (Q), lumefantrine (Lum), monodesethylamodiaquine (MDA), piperaquine (PPQ) and dihydroartemisinin (DHA) was investigated in children (6 months – 15 years) with a parasitaemia of at least ?4,000/?l. The modified isotopic microtest technique was used. The results of cellular proliferation were analysed using ICEstimator software to determine the 50% inhibitory concentration (IC50) values. Results DHA was the most potent among the 6 drugs tested, with IC50 values ranging from 0.8 nM to 0.9 nM (Geometric mean IC50?=?0.8 nM; 95% CI [0.8 - 0.9]). High IC50 values ranged between 0.8 nM to 166.1 nM were reported for lumefantrine (Geometric mean IC50?=?25.1 nM; 95% CI [22.4 - 28.2]). MDA and Q IC50s were significantly higher in CQ-resistant than in CQ-sensitive isolates (P?=?0.0001). However, the opposite occurred for Lum and DHA (P?

2014-01-01

292

Study of the bioremediation of atrazine under variable carbon and nitrogen sources by mixed bacterial consortium isolated from corn field soil in Fars province of Iran.  

PubMed

Atrazine herbicide that is widely used in corn production is frequently detected in water resources. The main objectives of this research were focused on assessing the effects of carbon and nitrogen sources on atrazine biodegradation by mixed bacterial consortium and by evaluating the feasibility of using mixed bacterial consortium in soil culture. Shiraz corn field soil with a long history of atrazine application has been explored for their potential of atrazine biodegradation. The influence of different carbon compounds and the effect of nitrogen sources and a different pH (5.5-8.5) on atrazine removal efficiency by mixed bacterial consortium in liquid culture were investigated. Sodium citrate and sucrose had the highest atrazine biodegradation rate (87.22%) among different carbon sources. Atrazine biodegradation rate decreased more quickly by the addition of urea (26.76%) compared to ammonium nitrate. Based on the data obtained in this study, pH of 7.0 is optimum for atrazine biodegradation. After 30 days of incubation, the percent of atrazine reduction rates were significantly enhanced in the inoculated soils (60.5%) as compared to uninoculated control soils (12%) at the soil moisture content of 25%. In conclusion, bioaugmentation of soil with mixed bacterial consortium may enhance the rate of atrazine degradation in a highly polluted soil. PMID:23533452

Dehghani, Mansooreh; Nasseri, Simin; Hashemi, Hassan

2013-01-01

293

Field and laboratory investigations of coring-induced damage in core recovered from Marker Bed 139 at the waste isolation pilot plant underground facility  

SciTech Connect

A combined laboratory and field investigation was carried out to determine the extent of coring-induced damage done to samples cored from Marker Bed 139 at the WIPP site. Coring-induced damage, if present, has the potential to significantly change the properties of the material used for laboratory testing relative to the in situ material properties, resulting in misleading conclusions. In particular, connected, crack-like damage could make the permeability of cored samples orders of magnitude greater than the in situ permeabilities. Our approach compared in situ velocity and resistivity measurements with laboratory measurements of the same properties. Differences between in situ and laboratory results could be attributed to differences in the porosity due to cracks. The question of the origin of the changes could not be answered directly from the results of the measurements. Pre-existing cracks, held closed by the in situ stress, could open when the core was cut free, or new cracks could be generated by coring-induced damage. We used core from closely spaced boreholes at three orientations (0{degree}, {plus_minus}45{degrees} relative to vertical) to address the origin of cracks. The absolute orientation of pre-existing cracks would be constant, independent of the borehole orientation. In contrast, cracks induced by coring were expected to show an orientation dependent on that of the source borehole.

Holcomb, D.J.; Zeuch, D.H.; Morin, K.; Hardy, R.; Tormey, T.V.

1995-09-01

294

Atomically thin nonreciprocal optical isolation  

PubMed Central

Optical isolators will play a critical role in next-generation photonic circuits, but their on-chip integration requires miniaturization with suitable nonreciprocal photonic materials. Here, we theoretically demonstrate the thinnest possible and polarization-selective nonreciprocal isolation for circularly polarized waves by using graphene monolayer under an external magnetic field. The underlying mechanism is that graphene electron velocity can be largely different for the incident wave propagating in opposite directions at cyclotron frequency, making graphene highly conductive and reflective in one propagation direction while transparent in the opposite propagation direction under an external magnetic field. When some practical loss is introduced, nonreciprocal isolation with graphene monolayer still possesses good performance in a broad bandwidth. Our work shows the first study on the extreme limit of thickness for optical isolation and provides theoretical guidance in future practical applications.

Lin, Xiao; Wang, Zuojia; Gao, Fei; Zhang, Baile; Chen, Hongsheng

2014-01-01

295

Atomically thin nonreciprocal optical isolation.  

PubMed

Optical isolators will play a critical role in next-generation photonic circuits, but their on-chip integration requires miniaturization with suitable nonreciprocal photonic materials. Here, we theoretically demonstrate the thinnest possible and polarization-selective nonreciprocal isolation for circularly polarized waves by using graphene monolayer under an external magnetic field. The underlying mechanism is that graphene electron velocity can be largely different for the incident wave propagating in opposite directions at cyclotron frequency, making graphene highly conductive and reflective in one propagation direction while transparent in the opposite propagation direction under an external magnetic field. When some practical loss is introduced, nonreciprocal isolation with graphene monolayer still possesses good performance in a broad bandwidth. Our work shows the first study on the extreme limit of thickness for optical isolation and provides theoretical guidance in future practical applications. PMID:24569672

Lin, Xiao; Wang, Zuojia; Gao, Fei; Zhang, Baile; Chen, Hongsheng

2014-01-01

296

Influence of an inner-sphere K+ ion on the magnetic behavior of N2(3-) radical-bridged dilanthanide complexes isolated using an external magnetic field.  

PubMed

The synthesis and full magnetic characterization of a new series of N2(3-) radical-bridged lanthanide complexes [{(R2N)2(THF)Ln}2(?3-?(2):?(2):?(2)-N2)K] [1-Ln; Ln = Gd, Tb, Dy; NR2 = N(SiMe3)2] are described for comprehensive comparison with the previously reported series [K(18-crown-6)(THF)2]{[(R2N)2(THF)Ln]2(?-?(2):?(2)-N2)} (2-Ln; Ln = Gd, Tb, Dy). Structural characterization of 1-Ln crystals grown with the aid of a Nd2Fe13B magnet reveals inner-sphere coordination of the K(+) counterion within 2.9 Å of the N2(3-) bridge, leading to bending of the planar Ln-(N2(3-))-Ln unit present in 2-Ln. Direct current (dc) magnetic susceptibility measurements performed on 1-Gd reveal antiferromagnetic coupling between the Gd(III) centers and the N2(3-) radical bridge, with a strength matching that obtained previously for 2-Gd at J ? -27 cm(-1). Unexpectedly, however, a competing antiferromagnetic Gd(III)-Gd(III) exchange interaction with J ? -2 cm(-1) also becomes prominent, dramatically changing the magnetic behavior at low temperatures. Alternating current (ac) magnetic susceptibility characterization of 1-Tb and 1-Dy demonstrates these complexes to be single-molecule magnets under zero applied dc field, albeit with relaxation barriers (Ueff = 41.13(4) and 14.95(8) cm(-1), respectively) and blocking temperatures significantly reduced compared to 2-Tb and 2-Dy. These differences are also likely to be a result of the competing antiferromagnetic Ln(III)-Ln(III) exchange interactions of the type quantified in 1-Gd. PMID:24580373

Meihaus, Katie R; Corbey, Jordan F; Fang, Ming; Ziller, Joseph W; Long, Jeffrey R; Evans, William J

2014-03-17

297

Neonatal tactile stimulation reverses the effect of neonatal isolation on open-field and anxiety-like behavior, and pain sensitivity in male and female adult Sprague-Dawley rats.  

PubMed

It is well known that early life events induce long-lasting psychophysiological and psychobiological influences in later life. In rodent studies, environmental enrichment after weaning prevents the adulthood behavioral and emotional disturbances in response to early adversities. We compared the behavioral effect of neonatal isolation (NI) with the effect of NI accompanied by tactile stimulation (NTS) to determine whether NTS could reverse or prevent the effects of NI on the adulthood behavioral and emotional responses to environmental stimuli. In addition, we also examined the sex difference of the NTS effect. Measurements of body weights, an open-field locomotor test, an elevated plus maze test, a hot-plate test, and a contextual fear-conditioning test were performed on postnatal day 60. As compared with rats subjected to NI, rats subjected to NTS showed significantly higher activity and exploration in the open-field locomotor test, lower anxiety-like behavior in the elevated plus maze test, and significantly prolonged latencies in the hot-plate test, and this effect was equal among males and females. In the contextual fear-conditioning test, whereas NTS significantly reduced the enhanced freezing time due to NI in females, no significant difference in the freezing time between NI and NTS was found in males. These findings indicate that adequate tactile stimulation in early life plays an important role in the prevention of disturbances in the behavioral and emotional responses to environmental stimuli in adulthood induced by early adverse experiences. PMID:17854917

Imanaka, A; Morinobu, S; Toki, S; Yamamoto, S; Matsuki, A; Kozuru, T; Yamawaki, S

2008-01-10

298

Isolating Triggered Star Formation  

SciTech Connect

Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.

Barton, Elizabeth J.; Arnold, Jacob A.; /UC, Irvine; Zentner, Andrew R.; /KICP, Chicago /Chicago U., EFI; Bullock, James S.; /UC, Irvine; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

2007-09-12

299

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated ?-Fe2O3 nano-sized particles and assessment of their effects on glutamate transport  

PubMed Central

Summary The manipulation of brain nerve terminals by an external magnetic field promises breakthroughs in nano-neurotechnology. D-Mannose-coated superparamagnetic nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) salts followed by oxidation with sodium hypochlorite and addition of D-mannose. Effects of D-mannose-coated superparamagnetic maghemite (?-Fe2O3) nanoparticles on key characteristics of the glutamatergic neurotransmission were analysed. Using radiolabeled L-[14C]glutamate, it was shown that D-mannose-coated ?-Fe2O3 nanoparticles did not affect high-affinity Na+-dependent uptake, tonic release and the extracellular level of L-[14C]glutamate in isolated rat brain nerve terminals (synaptosomes). Also, the membrane potential of synaptosomes and acidification of synaptic vesicles was not changed as a result of the application of D-mannose-coated ?-Fe2O3 nanoparticles. This was demonstrated with the potential-sensitive fluorescent dye rhodamine 6G and the pH-sensitive dye acridine orange. The study also focused on the analysis of the potential use of these nanoparticles for manipulation of nerve terminals by an external magnetic field. It was shown that more than 84.3 ± 5.0% of L-[14C]glutamate-loaded synaptosomes (1 mg of protein/mL) incubated for 5 min with D-mannose-coated ?-Fe2O3 nanoparticles (250 µg/mL) moved to an area, in which the magnet (250 mT, gradient 5.5 ?/m) was applied compared to 33.5 ± 3.0% of the control and 48.6 ± 3.0% of samples that were treated with uncoated nanoparticles. Therefore, isolated brain nerve terminals can be easily manipulated by an external magnetic field using D-mannose-coated ?-Fe2O3 nanoparticles, while the key characteristics of glutamatergic neurotransmission are not affected. In other words, functionally active synaptosomes labeled with D-mannose-coated ?-Fe2O3 nanoparticles were obtained.

Krisanova, Natalia; Bor?sov, Arsenii; Sivko, Roman; Ostapchenko, Ludmila; Babic, Michal; Horak, Daniel

2014-01-01

300

Manipulation of isolated brain nerve terminals by an external magnetic field using D-mannose-coated ?-Fe2O3 nano-sized particles and assessment of their effects on glutamate transport.  

PubMed

The manipulation of brain nerve terminals by an external magnetic field promises breakthroughs in nano-neurotechnology. D-Mannose-coated superparamagnetic nanoparticles were synthesized by coprecipitation of Fe(II) and Fe(III) salts followed by oxidation with sodium hypochlorite and addition of D-mannose. Effects of D-mannose-coated superparamagnetic maghemite (?-Fe2O3) nanoparticles on key characteristics of the glutamatergic neurotransmission were analysed. Using radiolabeled L-[(14)C]glutamate, it was shown that D-mannose-coated ?-Fe2O3 nanoparticles did not affect high-affinity Na(+)-dependent uptake, tonic release and the extracellular level of L-[(14)C]glutamate in isolated rat brain nerve terminals (synaptosomes). Also, the membrane potential of synaptosomes and acidification of synaptic vesicles was not changed as a result of the application of D-mannose-coated ?-Fe2O3 nanoparticles. This was demonstrated with the potential-sensitive fluorescent dye rhodamine 6G and the pH-sensitive dye acridine orange. The study also focused on the analysis of the potential use of these nanoparticles for manipulation of nerve terminals by an external magnetic field. It was shown that more than 84.3 ± 5.0% of L-[(14)C]glutamate-loaded synaptosomes (1 mg of protein/mL) incubated for 5 min with D-mannose-coated ?-Fe2O3 nanoparticles (250 µg/mL) moved to an area, in which the magnet (250 mT, gradient 5.5 ?/m) was applied compared to 33.5 ± 3.0% of the control and 48.6 ± 3.0% of samples that were treated with uncoated nanoparticles. Therefore, isolated brain nerve terminals can be easily manipulated by an external magnetic field using D-mannose-coated ?-Fe2O3 nanoparticles, while the key characteristics of glutamatergic neurotransmission are not affected. In other words, functionally active synaptosomes labeled with D-mannose-coated ?-Fe2O3 nanoparticles were obtained. PMID:24991515

Borisova, Tatiana; Krisanova, Natalia; Bor?sov, Arsenii; Sivko, Roman; Ostapchenko, Ludmila; Babic, Michal; Horak, Daniel

2014-01-01

301

Vortex Shedding Noise of an Isolated Airfoil.  

National Technical Information Service (NTIS)

The purpose of the study was to determine the vortex shedding noise characteristics of isolated airfoils in a Reynolds number range applicable to full-scale helicopter rotors. Measurements of far-field noise, airfoil surface pressure fluctuations, and cor...

C. L. Munich M. R. Fink P. G. Vogt R. W. Paterson

1971-01-01

302

Epidemiology of Tsutsugamushi disease in relation to the serotypes of Rickettsia tsutsugamushi isolated from patients, field mice, and unfed chiggers on the eastern slope of Mount Fuji, Shizuoka Prefecture, Japan.  

PubMed

A total of 59 strains of Rickettsia tsutsugamushi were isolated from patients (24 isolates), Apodemus speciosus mice (30 isolates), and unfed larvae of Leptotrombidium scutellare (2 isolates) and Leptotrombidium pallidum (3 isolates) in the Gotenba-Oyama District, Shizuoka Prefecture, Japan. All these isolates were classified into the three serotypes Karp, Kawasaki, and Kuroki based on reactivity with strain-specific monoclonal antibodies. Kawasaki- and Karp-type rickettsiae were isolated from L. scutellare and L. pallidum, respectively, and the geographic distribution of patients and rodents infected with these two types of rickettsiae coincided with the areas densely populated by the respective chiggers. From these results, we conclude that Kawasaki-type rickettsiae are transmitted by L. scutellare and Karp-type ones are transmitted by L. pallidum. Kawasaki-type rickettsial infections were prevalent in early autumn, and Karp-type infections showed a peak of occurrence in the late autumn, reflecting the seasonal fluctuations of L. scutellare and L. pallidum. Isolates of Kuroki-type rickettsiae were obtained only from four patients in October and November, and the relationship between this type of rickettsia and its vector species could not be fully defined. PMID:1452653

Kawamori, F; Akiyama, M; Sugieda, M; Kanda, T; Akahane, S; Uchikawa, K; Yamada, Y; Kumada, N; Furuya, Y; Yoshida, Y

1992-11-01

303

Isolated Northern Dunes  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site]

Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

This VIS image was taken at 81 degrees North latitude during Northern spring. In this region, the dunes are isolated from each other. The dunes are just starting to emerge from the winter frost covering appearing dark with bright crests. These dunes are located on top of ice.

Image information: VIS instrument. Latitude 82.1, Longitude 191.3 East (168.7 West). 19 meter/pixel resolution.

Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

2005-01-01

304

Isolated neutron stars in the galaxy: from magnetars to antimagnetars  

SciTech Connect

Using the model with decaying magnetic fields it is possible to describe with one smooth (log-Gaussian) initial magnetic field distribution three types of isolated neutron stars: radiopulsar, magnetars, and cooling close-by compact objects. The same model is used here to make predictions for old accreting isolated neutron stars. It is shown that using the updated field distribution we predict a significant fraction of isolated neutron stars at the stage of accretion despite long subsonic propeller stage.

Boldin, P. A., E-mail: boldin.pavel@gmail.com [Moscow Engineering Physics Institute (State University) (Russian Federation); Popov, S. B., E-mail: polar@sai.msu.ru [Moscow State University, Sternberg Astronomical Institute (Russian Federation)

2012-07-15

305

Semileaky thin-film optical isolator  

SciTech Connect

Two interesting effects have been experimentally demonstrated for the first time: (1) simultaneous reciprocal and nonreciprocal mode conversion to achieve an isolation effect and (2) magneto-optic switching between guided and radiation modes. These effects were observed in connection with the construction of a previously proposed thin-film optical isolator. The isolator consists of a piece of LiNbO/sub 3/ placed on top of a thin film of yttrium ion garnet (YIG) with a selenium layer to avoid optical contact problems. The isolator, which is 1 cm long, exhibited 10 dB of isolation at lambda = 1.15 ..mu..m. The observed isolation was better than theoretical predictions and a mysterious isolation direction dependence on mode order was observed. Although the device had 10 dB of insertion loss and required a magnetic field of 40 Oe, with a slight change in wavelength and film composition, it should be possible to reduce the insertion loss and field required to under 1 dB and 0.1 Oe, respectively. These characteristics combined with broad tolerances on film thickness and the length of the isolation region, broadband operation (from lambda = 1.1 to 4.5 ..mu..m), and easy construction and adjustment make the isolator very attractive for use in integrated optics.

Kirsch, S.T.; Biolsi, W.A.; Blank, S.L.; Tien, P.K.; Martin, R.J.; Bridenbaugh, P.M.; Grabbe, P.

1981-05-01

306

Cyclotide isolation and characterization.  

PubMed

Cyclotides are disulfide-rich cyclic peptides produced by plants with the presumed natural function of defense agents against insect pests. They are present in a wide range of plant tissues, being ribosomally synthesized via precursor proteins that are posttranslationally processed to produce mature peptides with a characteristic cyclic backbone and cystine knot motif associated with their six conserved cysteine residues. Their processing is not fully understood but involves asparaginyl endoproteinase activity. In addition to interest in their defense roles and their unique topologies, cyclotides have attracted attention as potential templates in peptide-based drug design applications. This chapter provides protocols for the isolation of cyclotides from plants, their detection and sequencing by mass spectrometry, and their structural analysis by NMR, as well as describing methods for the isolation of nucleic acid sequences that encode their precursor proteins. Assays to assess their membrane-binding interactions are also described. These protocols provide a "starter kit" for researchers entering the cyclotide field. PMID:23034223

Craik, David J; Henriques, Sonia Troeira; Mylne, Joshua S; Wang, Conan K

2012-01-01

307

Magnetically coupled signal isolator  

NASA Technical Reports Server (NTRS)

A current determiner having an output at which representations of input currents are provided having an input conductor for the input current and a current sensor supported on a substrate electrically isolated from one another but with the sensor positioned in the magnetic fields arising about the input conductor due to any input currents. The sensor extends along the substrate in a direction primarily perpendicular to the extent of the input conductor and is formed of at least a pair of thin-film ferromagnetic layers separated by a non-magnetic conductive layer. The sensor can be electrically connected to electronic circuitry formed in the substrate including a nonlinearity adaptation circuit to provide representations of the input currents of increased accuracy despite nonlinearities in the current sensor, and can include further current sensors in bridge circuits.

Black, Jr., William C. (Inventor); Hermann, Theodore M. (Inventor)

2001-01-01

308

Isolated systems in general relativity  

NASA Astrophysics Data System (ADS)

Isolated systems in General Relativity were studied. Radiation effects on composite isolated systems are examined. The non-linear asymptotic vacuum field equations were solved in the formalism of Newman and Penrose. A Spin Weight Spherical Harmonics representation of the source was used. The concept of angular momentum is examined for isolated systems in General Relativity. It is argued that, on physical grounds, the definition of angular momentum in General Relativity should stem from the expression linear momentum in a way similar to the expression L = rxP used for theories in pseudo-Euclidian spaces. Starting from the most commonly accepted definitions of energy-momentum, it is found that the Landau and Lifshitz quantity which is the only one derived from a symmetric energy momentum expression is also the only one to reduce to the angular momentum of the non-radiative exact Kerr solution. This result is strikingly different from what is usually proposed in the literature.

Cresswell, A.

309

New serotypes of Riemerella anatipestifer isolated from ducks in Thailand  

Microsoft Academic Search

Thirty?two Riemerella anatipestifer isolates from ducks were serotyped by agar gel precepitin test using chicken antisera against serotypes 1 to 19 R. anatipestifer reference strains. The heat stable saline extracts from 29 field isolates reacted with the antisera of serotypes 1, 6, 7, 10, 11, 14, or 19. The isolates belonging to serotype 1 were the most prevalent (56.3%). Antigens

Pornpen Pathanasophon; Takuo Sawada; Tipa Tanticharoenyos

1995-01-01

310

Review on Recent Advances in the Analysis of Isolated Organelles  

PubMed Central

The analysis of isolated organelles is one of the pillars of modern bioanalytical chemistry. This review describes recent developments on the isolation and characterization of isolated organelles both from living organisms and cell cultures. Salient reports on methods to release organelles focused on reproducibility and yield, membrane isolation, and integrated devices for organelle release. New developments on organelle fractionation after their isolation were on the topics of centrifugation, immunocapture, free flow electrophoresis, flow field-flow fractionation, fluorescence activated organelle sorting, laser capture microdissection, and dielectrophoresis. New concepts on characterization of isolated organelles included atomic force microscopy, optical tweezers combined with Raman spectroscopy, organelle sensors, flow cytometry, capillary electrophoresis, and microfluidic devices.

Satori, Chad P.; Kostal, Vratislav; Arriaga, Edgar A.

2012-01-01

311

Gravitational anomaly and Hawking radiation near a weakly isolated horizon  

Microsoft Academic Search

Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near a weakly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near a horizon is a 2-dimensional chiral scalar field. This

Wu Xiaoning; Huang Chaoguang; Sun Jiarui

2008-01-01

312

Optically Isolated Amplifier.  

National Technical Information Service (NTIS)

The design presented was used for biomedical signal detection and monitoring. The amplifier was successfully applied for EMG and ECG research studies. The patient is safely isolated from the processing equipment when using the amplifier. This opto-isolate...

C. J. Smith

1982-01-01

313

Bacillus Odysseyi Isolate.  

National Technical Information Service (NTIS)

The present invention relates to discovery and isolation of a biologically pure culture of a Bacillus odysseyi isolate with high adherence and sterilization resistant properties. B. odysseyi is a round spore forming Bacillus species that produces an exosp...

K. Venkateswaran M. T. La Duc

2007-01-01

314

Psychopathology of social isolation  

PubMed Central

The most important defining factor of being human is the use of symbolic language. Language or communication problem occurs during the growth, the child will have a higher risk of social isolation and then the survival will be threatened constantly. Today, adolescents and youths are familiar with computer and smart-phone devices, and communication with others by these devices is easy than face-to-face communication. As adolescents and youths live in the comfortable and familiar cyber-world rather than actively participating real society, so they make social isolation. Extreme form of this isolation in adolescents and youths is so-called Socially Withdrawn Youth. In this study, the psychopathological factors inducing social isolation were discussed. Development stages of social isolation in relation with types of social isolation, Ego-syntonic isolation and Ego-dystonic isolation, were also considered.

Baek, Sang-Bin

2014-01-01

315

Molecular fingerprinting of clinical isolates of Mycobacterium bovis and Mycobacterium tuberculosis from India by restriction fragment length polymorphism (RFLP)  

Microsoft Academic Search

Forty mycobacterial strains comprising clinical Indian isolates of Mycobacterium tuberculosis (28 field isolates + 1H37 Rv) and Mycobacterium bovis (10 field isolates + 1 AN5) were subjected to restriction fragment length polymorphism analysis (RFLP) using IS6110 and IS1081 probes. Most of these strains originated from dairy cattle herd and human patients from Indian Veterinary research Institute (IVRI) campus isolated from

Sandeep Kumar Singh; Devendra H. Shah

316

Flexure Elastomer Antenna Isolation System.  

National Technical Information Service (NTIS)

A vibration isolation system for a payload. The vibration isolation system provides a level of vibration isolation for all vibration translational and rotational components, while minimizing the moment of the payload mass relative to the isolation system....

A. J. Vajanyi D. Calhoun M. Hoffman R. I. Harless R. T. Fandrich

2004-01-01

317

Correlation of SfiI macrorestriction endonuclease fingerprint analysis of Candida parapsilosis isolates with source of isolation.  

PubMed

SfiI macrorestriction digests from whole chromosome DNA preparations of 46 isolates of Candida parapsilosis from vaginal (20 isolates), blood (23 isolates) and soil (three isolates) sources were examined by CHEF-MAPPER pulsed-field electrophoresis. The isolates were grouped into nine macrorestriction endonuclease fingerprint (MEF) classes according to the number or size of the macrorestriction fragments, or both. The electrophoretic karyotype (EK) was also examined and found to contain 18 karyotypic classes (named A-R). A comparison between SfiI MEF and EK demonstrated that the former correlated much better than the latter with the source of C. parapsilosis isolates. Five SfiI classes (I-V) contained only vaginal isolates (or vaginal and three soil isolates, class I), and the blood isolates were distributed between four classes (VI-IX). This relationship was less evident with the EK classes as several of these were composed of both vaginal and blood isolates (B, G, L and M). The three soil isolates were in class A which also included one vaginal isolate. We conclude that SfiI macrorestriction endonuclease patterns seem to be useful in discriminating among C. parapsilosis isolates, with apparent association with source of isolation. PMID:8810943

Pontieri, E; Gregori, L; Gennarelli, M; Ceddia, T; Novelli, G; Dallapiccola, B; De Bernardis, F; Carruba, G

1996-09-01

318

Seismic assessment of bridge structures isolated by a shape memory alloy/rubber-based isolation system  

NASA Astrophysics Data System (ADS)

This paper explores the effectiveness of shape memory alloy (SMA)/rubber-based isolation systems for seismic protection of bridges against near-field earthquakes by performing a sensitivity analysis. The isolation system considered in this study consists of a laminated rubber bearing, which provides lateral flexibility while supplying high vertical load-carrying capacity, and an auxiliary device made of multiple loops of SMA wires. The SMA device offers additional energy dissipating and re-centering capability. A three-span continuous bridge is modeled with the SMA/rubber-based (SRB) isolation system. Numerical simulations of the bridge are conducted for various near-field ground motions that are spectrally matched to a target design spectrum. The normalized forward transformation strength, forward transformation displacement and pre-strain level of the SMA device, ambient temperature and the lateral stiffness of the rubber bearings are selected as parameters of the sensitivity study. The variation of the seismic response of the bridge with the considered parameters is assessed. Also, the performance of the SRB isolation system with optimal design parameters is compared with an SMA-based sliding isolation system. The results indicate that the SRB isolation system can successfully reduce the seismic response of highway bridges; however, a smart isolation system that combines sliding bearings together with an SMA device is more efficient than the SRB isolation system.

Ozbulut, Osman E.; Hurlebaus, Stefan

2011-01-01

319

Vibration isolation technology experiment  

NASA Technical Reports Server (NTRS)

The objectives of the vibration isolation technology experiment are to demonstrate the viability of the magnetic suspension technology in providing the isolation of large structures elements from the external environment and to quantify the degree of isolation provided by this system. The approach proposed for this experiment is to mount a six-degrees-of-freedom magnetic bearing suspension system at the free end of a shuttle-attached flexible structure such as MAST. The disturbance generator, located on top of the isolation system, will be energized at selected and broadband frequencies to simulate a typical spacecraft vibration environment. Sensors located on the isolation system and the flexible structures element will be used to quantify the degree of isolation provided by this system.

Keckler, C. R.

1984-01-01

320

Listeria fleischmannii sp. nov., isolated from cheese.  

PubMed

A study was performed on three isolates (LU2006-1(T), LU2006-2 and LU2006-3), which were sampled independently from cheese in western Switzerland in 2006, as well as a fourth isolate (A11-3426), which was detected in 2011, using a polyphasic approach. The isolates could all be assigned to the genus Listeria but not to any known species. Phenotypic and chemotaxonomic data were compatible with the genus Listeria and phylogenetic analysis based on 16S rRNA gene sequences confirmed that the closest relationships were with members of this genus. However, DNA-DNA hybridization demonstrated that the isolates did not belong to any currently described species. Cell-wall-binding domains of Listeria monocytogenes bacteriophage endolysins were able to attach to the isolates, confirming their tight relatedness to the genus Listeria. Although PCR targeting the central portion of the flagellin gene flaA was positive, motility was not observed. The four isolates could not be discriminated by Fourier transform infrared spectroscopy or pulsed-field gel electrophoresis. This suggests that they represent a single species, which seems to be adapted to the environment in a cheese-ripening cellar as it was re-isolated from the same type of Swiss cheese after more than 5 years. Conjugation experiments demonstrated that the isolates harbour a transferable resistance to clindamycin. The isolates did not exhibit haemolysis or show any indication of human pathogenicity or virulence. The four isolates are affiliated with the genus Listeria but can be differentiated from all described members of the genus Listeria and therefore they merit being classified as representatives of a novel species, for which we propose the name Listeria fleischmannii sp. nov.; the type strain is LU2006-1(T) (?=?DSM 24998(T) ?=?LMG 26584(T)). PMID:22523164

Bertsch, David; Rau, Jörg; Eugster, Marcel R; Haug, Martina C; Lawson, Paul A; Lacroix, Christophe; Meile, Leo

2013-02-01

321

Inoculation of newly hatched broiler chicks with two Brazilian isolates of Salmonella Heidelberg strains with different virulence gene profiles, antimicrobial resistance, and pulsed field gel electrophoresis patterns to intestinal changes evaluation.  

PubMed

Salmonella Heidelberg is one of the 3 most frequently isolated serovars from human Salmonella cases in Canada, and the fourth most commonly reported Salmonella serovar in human foodborne disease cases in the United States. Since 1962, Salmonella Heidelberg has been isolated and reported in poultry and poultry products in Brazil. The poultry industry has focused efforts on reducing salmonellae incidence in live production in an effort to reduce Salmonella in the processing plant. A better understanding of the initial infection in chicks could provide approaches to control Salmonella contamination. The objective of the present study was to evaluate 2 Salmonella Heidelberg strains that differed in the presence of virulence genes invA, agfA, and lpfA; antimicrobial resistance profiles; and epidemiologic profiles on aspects of pathogenicity and intestinal morphology. Newly hatched broiler chicks were inoculated with 2 strains (SH23 and SH35) of Salmonella Heidelberg and cecal morphometry, histopathology, electron microscopy, and bacterial counts in the liver and cecum were assessed. The SH23 and SH35 strains resulted in different changes in villi height and crypt depth and inflammatory cell infiltration in the cecum. The SH35 group had higher liver and cecum bacterial cell counts when compared with SH23 strains. PMID:19276418

Borsoi, A; Santin, E; Santos, L R; Salle, C T P; Moraes, H L S; Nascimento, V P

2009-04-01

322

Isolating positioning boom for instrument platform  

US Patent & Trademark Office Database

A positioning boom disposed between a space-based observatory platform and its instrument payload provides thermal and dynamic isolation as well as fine pointing and momentum control. The inventive system isolates a sensitive payload from a warm, dynamically noisy spacecraft, which includes a sunshield. Isolation is required in terms of dynamics and heat flow, both in terms of the absolute level and its variance (thermal isolation). The present invention provides intrinsic control over momentum buildup (which is due to the separation of the center of pressure from the center of mass). The space-based platform also provides a view (field of regard) to at least half the sky (in the anti-sun direction).

2007-09-18

323

Serological characterization of Danish Haemophilus parasuis isolates.  

PubMed

A total of 103 Danish Haemophilus parasuis field isolates was collected from diseased pigs in connection with routine diagnostics. The isolates were serotyped using indirect haemagglutination (IHA) and for 57 of the isolates the serotyping was also performed by immunodiffusion. Serovar 5 was the most prevalent (36%), followed by serovar 4 (13%) and serovar 13 (22%), whereas 15% of the strains were nontypeable by IHA. Serovars 1, 2, 6, 7, 9, 12, 14, and 15 were only represented by a small number of isolates. Most of the Danish isolates belong to serovars, which earlier have been shown to be virulent. The strains could be divided into two groups depending on whether they were isolated from cases with systemic disease (polyserositis, arthritis or meningitis) or if they only were found in the lower respiratory tract. The most marked differences were observed for serovar 4, which had a higher prevalence in respiratory disease compared to systemic infection, and for the nontypeable isolates, which were mainly found in cases of systemic infection. PMID:15504597

Angen, Oystein; Svensmark, Birgitta; Mittal, Khyali R

2004-11-15

324

Novel Protocol for Persister Cells Isolation  

PubMed Central

Bacterial persistence, where a fraction of a population presents a transient resistance to bactericidal substances, has great medical importance due to its relation with the appearance of antibiotic resistances and untreatable bacterial chronic infections. The mechanisms behind this phenomenon remain largely unknown in spite of recent advances, in great part because of the difficulty in isolating the very small fraction of the population that is in this state at any given time. Current protocols for persister isolation have resulted in possible biases because of the induction of this state by the protocol itself. Here we present a novel protocol that allows rapid isolation of persister cells both from exponential and stationary phase. Moreover, it is capable of differentiating between type I and type II persister cells, which should allow the field to move beyond its current state of studying only one type. While this protocol prompts a revision of many of the current results, it should greatly facilitate further advances in the field.

Canas-Duarte, Silvia J.; Restrepo, Silvia; Pedraza, Juan Manuel

2014-01-01

325

Cell isolation and culture.  

PubMed

Cell isolation and culture are essential tools for the study of cell function. Isolated cells grown under controlled conditions can be manipulated and imaged at a level of resolution that is not possible in whole animals or even tissue explants. Recent advances have allowed for large-scale isolation and culture of primary C. elegans cells from both embryos and all four larval stages. Isolated cells can be used for single-cell profiling, electrophysiology, and high-resolution microscopy to assay cell autonomous development and behavior. This chapter describes protocols for the isolation and culture of C. elegans embryonic and larval stage cells. Our protocols describe isolation of embryonic and L1 stage cells from nematodes grown on high-density NA22 bacterial plates and isolation of L2 through L4 stage cells from nematodes grown in axenic liquid culture. Both embryonic and larval cells can be isolated from nematode populations within 3 hours and can be cultured for several days. A primer on sterile cell culture techniques is given in the appendices. PMID:23430760

Zhang, Sihui; Kuhn, Jeffrey R

2013-01-01

326

Improved active vibration isolator  

NASA Technical Reports Server (NTRS)

Active vibration isolator simultaneously isolates a flexible structure or payload from disturbances, attenuates the response of a flexible structure to transient disturbances, and maintains the equilibrium position of the payload within predetermined limits over a wide range of steady loads and accelerators.

Dixon, G. V.; Leatherwood, J. D.; Stephens, D. G.

1968-01-01

327

Antimicrobial Resistance in Enterococci Isolated from Turkey Flocks Fed Virginiamycin  

Microsoft Academic Search

From 125 separate cloacal cultures from three turkey flocks fed virginiamycin, 104 Enterococcus faecium and 186 Enterococcus faecalis isolates were obtained. As the turkeys aged, there was a higher percentage of quinupristin-dalfopristin-resistant E. faecium isolates, with isolates from the oldest flock being 100% resistant. There were no vancomycin-resistant enterococci. Results of pulsed-field gel electrophoresis (PFGE) indicated there were 11 PFGE

L. A. WELTON; L. A. THAL; M. B. PERRI; S. DONABEDIAN; J. MCMAHON; J. W. CHOW; M. J. ZERVOS

1998-01-01

328

Antimicrobial-resistant Salmonella serovars isolated from imported foods  

Microsoft Academic Search

A total of 187 Salmonella isolates representing 82 serotypes recovered from 4072 imported foods in the year 2000 by the U.S. Food and Drug Administration field laboratories were tested for their susceptibility to 17 antimicrobials of human and veterinary importance. Fifteen (8%) isolates were resistant to at least one antimicrobial, and five (2.7%) were resistant to three or more antimicrobials.

Shaohua Zhao; Atin R. Datta; Sherry Ayers; Sharon Friedman; Robert D. Walker; David G. White

2003-01-01

329

Fault detection and isolation  

NASA Astrophysics Data System (ADS)

In order for a current satellite-based navigation system (such as the Global Positioning System, GPS) to meet integrity requirements, there must be a way of detecting erroneous measurements, without help from outside the system. This process is called Fault Detection and Isolation (FDI). Fault detection requires at least one redundant measurement, and can be done with a parity space algorithm. The best way around the fault isolation problem is not necessarily isolating the bad measurement, but finding a new combination of measurements which excludes it.

Bernath, Greg

1994-02-01

330

Fault detection and isolation  

NASA Technical Reports Server (NTRS)

In order for a current satellite-based navigation system (such as the Global Positioning System, GPS) to meet integrity requirements, there must be a way of detecting erroneous measurements, without help from outside the system. This process is called Fault Detection and Isolation (FDI). Fault detection requires at least one redundant measurement, and can be done with a parity space algorithm. The best way around the fault isolation problem is not necessarily isolating the bad measurement, but finding a new combination of measurements which excludes it.

Bernath, Greg

1994-01-01

331

Whole Spacecraft Vibration Isolation.  

National Technical Information Service (NTIS)

The Department of Defense identified launch vibration isolation as a major research interest. Reducing the loads a satellite experiences during launch will greatly enhance the reliability, lifetime, and payload to structure ratio. DoD satellite programs s...

G. G. Karahalis

1999-01-01

332

Base isolation: Fresh insight  

SciTech Connect

The objective of the research is a further development of the engineering concept of seismic isolation. Neglecting the transient stage of seismic loading results in a widespread misjudgement: The force of resistance associated with velocity is mostly conceived as a source of damping vibrations, though it is an active force at the same time, during an earthquake type excitation. For very pliant systems such as base isolated structures with relatively low bearing stiffness and with artificially added heavy damping mechanism, the so called `damping`` force may occur even the main pushing force at an earthquake. Thus, one of the two basic pillars of the common seismic isolation philosophy, namely, the doctrine of usefulness and necessity of a strong damping mechanism, is turning out to be a self-deception, sometimes even jeopardizing the safety of structures and discrediting the very idea of seismic isolation. There is a way out: breaking with damping dependancy.

Shustov, V.

1993-07-15

333

Broadband RF Isolator.  

National Technical Information Service (NTIS)

A broadband RF isolator system for connection between RF devices such as colinear antennas is disclosed. In accordance with this invention, two or more antennas are spaced several wavelengths apart, connected to coaxial feeds and choked at their adjacent ...

C. M. Desantis

1981-01-01

334

Isolated lateral rectus myositis.  

PubMed

Orbital myositis is a rare non-granulomatous inflammatory process within the orbit. Grave's disease and lymphoproliferative disorders are considered the most common cause of orbital myositis. The idiopathic form should be considered after exclusion of known causes or associations. Isolated orbital myositis is a very rare form of this disease. We report a case of an isolated lateral rectus myositis to draw the attention of physicians to this condition, as prompt treatment in our patient resulted in complete recovery. PMID:21063661

Obeid, Tahir H; Qanash, Sultan A; Abulaban, Ahmad A; Al-Shamy, Abdalrhman M

2010-11-01

335

Genome conservation in isolates of Leptospira interrogans.  

PubMed Central

Reference strains for each of the 23 serogroups of Leptospira interrogans yielded different pulsed-field gel electrophoresis patterns of NotI digestion products. This was also the case for the 14 serovars belonging to serogroup Icterohaemorrhagiae (with one exception). The NotI restriction patterns of 45 clinical leptospiral isolates belonging to serovar icterohaemorrhagiae were analyzed and compared with those of type strains. No differences were observed between isolates from countries of different continents, namely, France, French Guiana, New Caledonia, and Tahiti. The pattern was indistinguishable from that of the reference strain of serovar icterohaemorrhagiae. Images FIG. 1 FIG. 2 FIG. 3

Herrmann, J L; Baril, C; Bellenger, E; Perolat, P; Baranton, G; Saint Girons, I

1991-01-01

336

Characterization of Salmonella Typhimurium isolates associated with septicemia in swine.  

PubMed

Salmonella Typhimurium is frequently isolated from pigs and may also cause enteric disease in humans. In this study, 33 isolates of S. Typhimurium associated with septicemia in swine (CS) were compared to 33 isolates recovered from healthy animals at slaughter (WCS). The isolates were characterized using phenotyping and genotyping methods. For each isolate, the phage type, antimicrobial resistance, and pulsed-field gel electrophoresis (PFGE) DNA profiles were determined. In addition, the protein profiles of each isolate grown in different conditions were studied by Coomassie Blue-stained sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot. Various phage types were identified. The phage type PT 104 represented 36.4% of all isolates from septicemic pigs. Resistance to as many as 12 antimicrobial agents, including some natural resistances, was found in isolates from CS and WCS. Many genetic profiles were identified among the PT 104 phage types. Although it was not possible to associate one particular protein with septicemic isolates, several highly immunogenic proteins, present in all virulent isolates and in most isolates from clinically healthy animals, were identified. These results indicated that strains associated with septicemia belong to various genetic lineages that can also be recovered from asymptomatic animals at the time of slaughter. PMID:20357952

Bergeron, Nadia; Corriveau, Jonathan; Letellier, Ann; Daigle, France; Quessy, Sylvain

2010-01-01

337

Characterization of Salmonella Typhimurium isolates associated with septicemia in swine  

PubMed Central

Salmonella Typhimurium is frequently isolated from pigs and may also cause enteric disease in humans. In this study, 33 isolates of S. Typhimurium associated with septicemia in swine (CS) were compared to 33 isolates recovered from healthy animals at slaughter (WCS). The isolates were characterized using phenotyping and genotyping methods. For each isolate, the phage type, antimicrobial resistance, and pulsed-field gel electrophoresis (PFGE) DNA profiles were determined. In addition, the protein profiles of each isolate grown in different conditions were studied by Coomassie Blue-stained sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot. Various phage types were identified. The phage type PT 104 represented 36.4% of all isolates from septicemic pigs. Resistance to as many as 12 antimicrobial agents, including some natural resistances, was found in isolates from CS and WCS. Many genetic profiles were identified among the PT 104 phage types. Although it was not possible to associate one particular protein with septicemic isolates, several highly immunogenic proteins, present in all virulent isolates and in most isolates from clinically healthy animals, were identified. These results indicated that strains associated with septicemia belong to various genetic lineages that can also be recovered from asymptomatic animals at the time of slaughter.

Bergeron, Nadia; Corriveau, Jonathan; Letellier, Ann; Daigle, France; Quessy, Sylvain

2010-01-01

338

Isolation of Shigellae  

PubMed Central

The efficiencies of three enrichment broths and four plating media for isolation of enteric pathogens were compared from 1,117 stool specimens. Direct streaking proved to be inferior to enrichment, detecting only 50% of the salmonellae and 61% of the shigellae. By contrast, Selenite Broth (SF) found 90% of the total salmonellae isolates and 82% of the shigellae isolates. Gram-Negative Broth (GN) found 82% and 85%, respectively, but Tetrathionate found only 60% and 39%. Thus, SF and GN were comparable for both salmonellae and shigellae and significantly better than Tetrathionate Broth for both. The plating media compared were MacConkey (MAC), deoxycholate citrate (DC), xylose lysine deoxycholate (XLD), and xylose lysine Brilliant Green (XLBG) Agars. Of the total salmonellae isolated, XLD produced 94%; XLBG, 71%; MAC, 55%; and DC, only 35%. Of shigellae, XLD found 89%; MAC, 75%; XLBG, 63%; and DC, but 27%. The efficacy of XLD is observed to be almost threefold that of DC. The most successful combination of media for the detection of fecal pathogens was GN or SF enrichment broths streaked to XLD plates. These analyses resulted in the isolation of 118 strains of salmonellae and 33 of shigellae.

Taylor, Welton I.; Schelhart, Dorothy

1968-01-01

339

Isolated syndesmosis ankle injury.  

PubMed

Isolated syndesmosis injuries often go unrecognized and are diagnosed as lateral ankle sprains; however, they are more disabling than lateral ankle sprains. The reported incidence of isolated syndesmosis injuries in acute ankle sprains ranges between 1% and 16%. When ankle disability lasts for more than 2 months after an ankle sprain, the incidence increases to 23.6%. Diagnostic workup may include stress radiographs, magnetic resonance imaging, or diagnostic arthroscopy. A simple stress test radiograph may reveal an unstable grade III syndesmosis sprain that may go unrecognized on plain anteroposterior and mortise or lateral radiographs of the ankle. The duration of symptoms in isolated syndesmosis injury is longer and more severe, often leading to chronic symptoms or ankle instability requiring operative stabilization.This article describes the clinical presentation, injury classification, and operative stabilization techniques of isolated syndesmosis injuries. The authors performed their preferred operative stabilization technique for isolated syndesmosis injury-arthroscopic debridement of the ankle with syndesmotic stabilization with a syndesmotic screw-in 4 patients. All patients were evaluated 1 year postoperatively with subjective and objective assessment scales. Three of 4 patients showed good improvement of general subjective ankle symptoms and subjective ankle instability rating and a high Sports Ankle Rating System score after 1 year. PMID:23218625

Valkering, Kars P; Vergroesen, Diederik A; Nolte, Peter A

2012-12-01

340

Isolation of C. elegans and related nematodes.  

PubMed

Isolating Caenorhabditis and other nematodes from the wild first requires field sampling (reviewed in Section 1). The easiest and most efficient way to recover the animals from any substrate is to place the sample onto a standard C. elegans culture plate (Section 2.1). Alternative methods used by nematologists to recover soil nematodes (Sections 2.2, 2.3, and 2.4) are in our hands more difficult to implement and only yield a fraction of the individuals in the sample. A tricky step is to recognize your species of interest out of the zoo of nematode species that comes with a typical sample (Section 3). Culture (Section 4) and freezing (Section 5) conditions are then reviewed. Finally, we briefly summarize the organization and timing of an isolation experiment (Section 6), as well as the available collections (Section 7). Bear in mind that this chapter is strongly focused towards the isolation of Caenorhabditis elegans and close relatives. PMID:24803426

Barrière, Antoine; Félix, Marie-Anne

2014-01-01

341

Genetic Diversity of Gallibacterium anatis Isolates from Different Chicken Flocks  

PubMed Central

Amplified fragment length polymorphisms (AFLPs) were used to characterize the genotypic diversity of a total of 114 Gallibacterium anatis isolates originating from a reference collection representing 15 biovars from four countries and isolates obtained from tracheal and cloacal swab samples of chickens from an organic, egg-producing flock and a layer parent flock. A subset of strains was also characterized by pulsed-field gel electrophoresis and biotyping. The organic flock isolates were characterized by more than 94% genetic similarity, indicating that only a single clone was apparent in the flock. The layer parent flock isolates were grouped into two subclusters, each with similarity above 90%. One subcluster contained only tracheal isolates, while the other primarily included cloacal isolates. In conclusion, we show that AFLP analysis enables fingerprinting of G. anatis, which seems to have a clonal population structure within natural populations. There was further evidence of clonal lineages, which may have adapted to different sites within the same animal.

Bojesen, Anders Miki; Torpdahl, Mia; Christensen, Henrik; Olsen, John Elmerdahl; Bisgaard, Magne

2003-01-01

342

Genetic diversity of Gallibacterium anatis isolates from different chicken flocks.  

PubMed

Amplified fragment length polymorphisms (AFLPs) were used to characterize the genotypic diversity of a total of 114 Gallibacterium anatis isolates originating from a reference collection representing 15 biovars from four countries and isolates obtained from tracheal and cloacal swab samples of chickens from an organic, egg-producing flock and a layer parent flock. A subset of strains was also characterized by pulsed-field gel electrophoresis and biotyping. The organic flock isolates were characterized by more than 94% genetic similarity, indicating that only a single clone was apparent in the flock. The layer parent flock isolates were grouped into two subclusters, each with similarity above 90%. One subcluster contained only tracheal isolates, while the other primarily included cloacal isolates. In conclusion, we show that AFLP analysis enables fingerprinting of G. anatis, which seems to have a clonal population structure within natural populations. There was further evidence of clonal lineages, which may have adapted to different sites within the same animal. PMID:12791918

Bojesen, Anders Miki; Torpdahl, Mia; Christensen, Henrik; Olsen, John Elmerdahl; Bisgaard, Magne

2003-06-01

343

Nucleic acid isolation process  

DOEpatents

A method is provided for isolating DNA from eukaryotic cell and flow sorted chromosomes. When DNA is removed from chromosome and cell structure, detergent and proteolytic digestion products remain with the DNA. These products can be removed with organic extraction, but the process steps associated with organic extraction reduce the size of DNA fragments available for experimental use. The present process removes the waste products by dialyzing a solution containing the DNA against a solution containing polyethylene glycol (PEG). The waste products dialyze into the PEG leaving isolated DNA. The remaining DNA has been prepared with fragments containing more than 160 kb. The isolated DNA has been used in conventional protocols without affect on the protocol.

Longmire, Jonathan L. (Los Alamos, NM); Lewis, Annette K. (La Jolla, CA); Hildebrand, Carl E. (Los Alamos, NM)

1990-01-01

344

Isolated facial cutaneous sarcoidosis  

PubMed Central

Isolated cutaneous sarcoidosis is a rare multisystemic granulomatous disorder of unknown etiology. Cutaneous lesions have been classified into specific and nonspecific depending on the presence of noncaseating granulomas on histopathologic studies. Macrophages most likely initiate the response of sarcoidosis by presenting unidentified antigens to CD4+ lymphocytes. A persistent poorly degradable antigen-driven CMI response leads to cytokine cascade, granulomaformation, and fibrosis. In the present study, we report a case of isolated cutaneous sarcoidosis, localized to the face, in an adolescent girl without systemic manifestations which is a rare entity.

Kumar, Sumir; Garg, Ravinder; Aggarwal, Simmi; Kaur, Jaskanwal

2012-01-01

345

Field Notes  

USGS Multimedia Gallery

The Field Records Collection has many materials types including: field notebooks, sketches, annotated maps, unpublished manuscripts, plane-table sheets, annotated aerial photographs, sample analysis, stratigraphic columns, lithologic logs, and geologic cross sections. Materials in the Field Records ...

2009-04-09

346

Development of a real-time tunable stiffness and damping vibration isolator based on magnetorheological elastomer  

Microsoft Academic Search

A tunable stiffness and damping vibration isolator based on magnetorheological elastomers (MREs) is developed. In this isolator, four MRE elements are used as the tunable springs, whose stiffness can be controlled by varying the magnetic field. A voice coil motor, which is controlled by the relative velocity feedback of the payload, is used as the tunable damper of the isolator.

G. J. Liao; X-L Gong; S. H. Xuan; C. J. Kang; L. H. Zong

2012-01-01

347

Molecular Typing of Mycobacterium bovis Isolates from Cameroon  

PubMed Central

In order to gain a better understanding of the molecular epidemiology of Mycobacterium bovis isolates in Cameroon, 75 isolates of M. bovis collected in three provinces of northern Cameroon were studied by spoligotyping. For 65 of these isolates, typing was also carried out by pulsed-field gel electrophoresis (PFGE) with DraI, and 18 of the isolates were also typed by restriction fragment length polymorphism (RFLP) analysis with probe IS6110-RHS. Molecular typing of the isolates by these techniques revealed a high degree of homogeneity, with 10 spoligotypes for 75 isolates, four PFGE profiles for 65 isolates, and three RFLP types for 18 isolates. Some types were present in the three different provinces, while some were confined to one or two areas. These results suggest that geographical mapping of M. bovis strains could be helpful for the control of bovine tuberculosis at the regional level. An interesting feature of all the spoligotypes was the absence of spacer 30, suggesting a common origin for all of the Cameroon isolates tested; an evolutionary scenario for the isolates is discussed. In addition, a comparison of the three techniques showed that for M. bovis strain differentiation in Cameroon and in surrounding countries, spoligotyping would be a more discriminating and practical tool for molecular typing than the other two techniques used in this study.

Njanpop-Lafourcade, Berthe M.; Inwald, Jacqueline; Ostyn, Annick; Durand, Benoit; Hughes, Steven; Thorel, Marie-Francoise; Hewinson, Glyn; Haddad, Nadia

2001-01-01

348

The Genotypic Characterization of Cronobacter spp. Isolated in China  

PubMed Central

Cronobacter spp. (Enterobacter sakazakii) is an important pathogen contaminating powdered infant formula (PIF). To describe the genotypic diversity of Cronobacter isolated in China, we identified the isolates using fusA allele sequencing, and subtyped all of the isolates using pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and multiple-locus variable-number tandem-repeat analysis (MLVA). A total of 105 isolates were identified, which included C. sakazakii (58 isolates), C. malonaticus (30 isolates), C. dublinensis (11 isolates), C. turicensis (5 isolates), and C. muytjensii (1 isolate). These isolates were showed to have 85 PFGE-patterns, 71 sequence types (STs), and 55 MLVA-patterns. Comparisons among the three molecular subtyping methods revealed that the PFGE method was the most distinguishable tool in identifying clusters of Cronobacter spp. through DNA fingerprinting, and MLST method came second. However, ESTR-1, ESTR-2, ESTR-3, and ESTR-4 were not effective loci for subtyping Cronobacter spp. such that the MLVA method requires further improvement.

Cui, Jinghua; Du, Xiaoli; Liu, Hui; Hu, Guangchun; Lv, Guoping; Xu, Baohong; Yang, Xiaorong; Li, Wei; Cui, Zhigang

2014-01-01

349

Spherically symmetric, metrically static, isolated systems in quasi-metric gravity  

Microsoft Academic Search

The gravitational field exterior respectively interior to a spherically symmetric, isolated body made of perfect fluid is examined within the quasi-metric framework (QMF). It is required that the gravitational field is \\

Dag Ostvang

2007-01-01

350

Development and characterization of a magnetorheological elastomer based adaptive seismic isolator  

NASA Astrophysics Data System (ADS)

One of the main shortcomings in current base isolation design/practice is lack of adaptability. As a result, a base isolation system that is effective for one type earthquake may become ineffective or may have adverse effect for other earthquakes. The vulnerability of traditional base isolation systems can be exaggerated by two types of earthquakes, i.e. near-field earthquakes and far-field earthquakes. This paper addresses the challenge facing current base isolation design/practice by proposing a new type of seismic isolator for the base isolation system, namely an adaptive seismic isolator. The novel adaptive seismic isolator utilizes magnetorheological elastomer (MRE) for its field-sensitive material property. Traditional seismic isolator design with a unique laminated structure of steel and MRE layers has been adopted in the novel MRE seismic isolator. To evaluate and characterize the behavior of the MRE seismic isolator, experimental testing was conducted on a shake table facility under harmonic cycling loading. Experimental results show that the proposed adaptive seismic isolator can successfully alter the lateral stiffness and damping force in real time up to 37% and 45% respectively. Based on the successful development of the novel adaptive seismic isolator, a discussion is also extended to the impact and potential applications of such a device in structural control applications in civil engineering.

Li, Yancheng; Li, Jianchun; Li, Weihua; Samali, Bijan

2013-03-01

351

Active Inertial Vibration Isolators And Dampers  

NASA Technical Reports Server (NTRS)

Report describes development of active inertial vibration isolators and dampers in which actuators electromagnet coils moving linearly within permanent magnetic fields in housings, somewhat as though massive, low-frequency voice coils in loudspeakers. Discusses principle of operation, electrical and mechanical considerations in design of actuators, characteristics of accelerometers, and frequency responses of control systems. Describes design and performance of one- and three-degree-of-freedom vibration-suppressing system based on concept.

Laughlin, Darren; Blackburn, John; Smith, Dennis

1994-01-01

352

Isolated patellofemoral osteoarthritis  

PubMed Central

Background and purpose The optimal treatment for isolated patellofemoral osteoarthritis is unclear at present. We systematically reviewed the highest level of available evidence on the nonoperative and operative treatment of isolated patellofemoral osteoarthritis to develop an evidenced-based discussion of treatment options. Methods A systematic computerized database search (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (PubMed), and EMBASE) was performed in March 2009. The quality of the studies was assessed independently by two authors using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Results We extracted data from 44 articles. The best available evidence for treatment of isolated patellofemoral osteoarthritis is sparse and of generally low methodological quality. Nonoperative treatment using physiotherapy (GRADE: high quality, weak recommendation for use), taping (GRADE: moderate quality, weak recommendation for use), or injection therapy (GRADE: very low quality, weak recommendation for use) may result in short-term relief. Joint-preserving surgical treatment may result in insufficient, unpredictable, or only short-term improvement (GRADE: low quality, weak recommendation against use). Total knee replacement with patellar resurfacing results in predictable and good, durable results (GRADE: low quality, weak recommendation for use). Outcome after patellofemoral arthroplasty in selected patients is good to excellent (GRADE: low quality, weak recommendation for use). Interpretation Methodologically good quality comparative studies, preferably using a patient-relevant outcome instrument, are needed to establish the optimal treatment strategy for patients with isolated patellofemoral osteoarthritis.

Poolman, Rudolf W; van Kampen, Albert

2010-01-01

353

Isolated ACTH Deficiency  

Microsoft Academic Search

Isolated ACTH is a rare cause of secondary adrenocortical insufficiency. The diagnosis is made by the demonstration of low cortisol production with low plasma ACTH, absent adrenal responses to stimulation for pituitary or hypothalamus with intact adrenal response to exogenous ACTH, and normal secretory indices of other pituitary hormones. We conclude that the diagnosis of this condition may be difficult

D. A. de Luis; R. Aller; E. Romero

1998-01-01

354

Aircraft EMP isolation study  

NASA Astrophysics Data System (ADS)

This report presents the results of a preliminary study into methods for electrically isolating the E-4B, the EC-135, and the EC-130 aircraft during EMP tests where the aircraft under test is directly driven by a high-voltage pulser.

Finci, A.; Price, H.; Chao, P.; Mercer, S.; Naff, T.

1980-07-01

355

Isolated gastric Crohn's disease  

PubMed Central

Crohn’s disease (CD) is a chronic idiopathic inflammatory disease of gastrointestinal tract characterized by segmental and transmural involvement of gastrointestinal tract. Ileocolonic and colonic/anorectal is a most common and account for 40% of cases and involvement of small intestine in about 30%. The stomach is rarely the sole or predominant site of CD. To date there are only a few documented case reports of adults with isolated gastric CD and no reports in the pediatric population. Isolated stomach involvement is very unusual presentation accounting for less than 0.07% of all gastrointestinal CD. The diagnosis is difficult to establish in cases of atypical presentation as in isolated gastroduodenal disease. In the absence of any other source of disease and in the presence of nonspecific upper GI endoscopy and histological findings, serological testing can play a vital role in the diagnosis of atypical CD. Recent studies have suggested that perinuclear anti-neutrophil cytoplasmic antibody and anti-Saccharomycescervisia antibody may be used as additional diagnostic tools. The effectiveness of infliximab in isolated gastric CD is limited to only a few case reports of adult patients and the long-term outcome is unknown.

Ingle, Sachin B; Hinge, Chitra R; Dakhure, Sarita; Bhosale, Smita S

2013-01-01

356

Mammary Stem Cell Isolation.  

National Technical Information Service (NTIS)

The objective of this research was to identify mouse mammary gland stem cells, with the ultimate goal being their isolation. We hypothesized that mammary gland stem cells can be identified by generating transgenic mice using a LEF/TCF-dependent reporter g...

D. J. Sussman

2004-01-01

357

Biological Isolation Garment  

NASA Technical Reports Server (NTRS)

A spinoff of astronaut's biological garment will allow hospital patients who are highly vulnerable to infection to leave their sterile habitats for several hours, carrying their germ free environment with them. Garments can be used in any of some 200 hospitals where isolation rooms are installed to treat leukemia.

1976-01-01

358

Fault isolation techniques  

NASA Technical Reports Server (NTRS)

Three major areas that are considered in the development of an overall maintenance scheme of computer equipment are described. The areas of concern related to fault isolation techniques are: the programmer (or user), company and its policies, and the manufacturer of the equipment.

Dumas, A.

1981-01-01

359

Isolated severe bilateral bronchomalacia.  

PubMed

Airway malacia is uncommon condition having symptoms similar to common respiratory illnesses. Any child having persistent wheeze during infancy should be evaluated for airway malacia. The authors report a case of isolated severe bilateral bronchomalacia managed with tracheostomy and continuous positive pressure ventilation. PMID:23715795

Saikia, Bhaskar; Sharma, Pradeep Kumar; Sharma, Rachna; Gagneja, Vikram; Khilnani, Praveen

2014-07-01

360

Phase Field  

NASA Astrophysics Data System (ADS)

The term phase field has recently become known across many fields of materials science. The meaning of phase field is the spatial and temporal order parameter field defined in a continuum-diffused interface model. By using the phase field order parameters, many types of complex microstructure changes observed in materials science are described effectively. This methodology has been referred to as the phase field method, phase field simulation, phase field modeling, phase field approach, etc. In this chapter, the basic concept and theoretical background for the phase field approach is explained in Sects. 21.1 and 21.2. The overview of recent applications of the phase field method is demonstrated in Sects. 21.3 to 21.6.

Koyama, Toshiyuki

361

Magneto-isolated complexes of solar structures  

NASA Astrophysics Data System (ADS)

We propose the concept of a large-scale complex of solar formations with an isolated magnetic field. The complex involves a group of coronal holes, active regions, and regions with intermediate characteristics between a coronal hole and the undisturbed (calm) region. An interesting feature of these complexes is the weak connection between the magnetic fields inside and outside the complexes. Most of the lines of the magnetic flux that emerge from the complex prove to be either opened or closed inside the complex.

Malashchuk, V. M.; Fainshtein, V. G.; Stepanian, N. N.; Rudenko, G. V.; Egorov, Ya. I.

2012-06-01

362

Change in response of bridges isolated with LRBs due to lead core heating  

Microsoft Academic Search

This study focuses on the response of seismic isolated bridges subjected to near-field ground motions with distinct pulse type behavior in terms of maximum isolator displacements (MIDs) and maximum isolator forces (MIFs) transferred to the substructure. The employed isolation systems are composed of lead rubber bearings (LRBs) with bi-linear force-deformation relations that consider cycle-to-cycle deterioration in the yield strength of

Gokhan Ozdemir; Ozgur Avsar; Beyhan Bayhan

2011-01-01

363

The effect of various Mycoplasma bovis isolates on bovine leukocyte responses.  

PubMed

Mycoplasma bovis (M. bovis) contributes to a number of clinical syndromes in cattle; in particular, chronic pneumonia that is poorly responsive to therapy has been increasingly recognized as an important cause of morbidity, mortality, and financial loss. M. bovis impairs host immune function, but little is known about whether field isolates vary significantly in their effect on immune function. This research tested the hypothesis that different field isolates vary in their ability to suppress cellular metabolism and cellular production of radical oxygen species (ROS) by bovine leukocytes. Total blood leukocytes from 6 cattle were exposed to six field isolates, two diagnostic lab isolates, and two high passage laboratory isolates of M. bovis, and ROS production was measured by oxidation of dihydrorhodamine 123 (DHR-123). Cellular metabolism was measured by reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Significant differences in the response to some field isolates were identified. Three field isolates and both diagnostic lab isolates significantly decreased ROS production by leukocytes from multiple cattle, while the high pass laboratory isolates did not. In contrast, MTT reduction was not significantly impaired by any of the M. bovis strains tested. M. bovis impairs ROS production by bovine leukocytes; the magnitude of the effect appears to be isolate-dependent, and is not related to a general impairment of cellular metabolism. Chronic M. bovis infection in some cattle may be related to impaired ability of leukocytes to produce ROS when exposed to M. bovis. PMID:20189247

Wiggins, M C; Woolums, A R; Hurley, D J; Sanchez, S; Ensley, D T; Donovan, D

2011-01-01

364

Tissue Interaction with Nonionizing Electromagnetic Fields. Final Report.  

National Technical Information Service (NTIS)

Studies of the effects of environmental low frequency electromagnetic fields on isolated cellular systems and tissue preparations derived from brain, bone, blood, and pancreas are reported. Behavioral effects of 60 Hz fields were examined in monkeys. Bioe...

W. R. Adey S. M. Bawin A. F. Lawrence S. Lin-Liu R. A. Luben

1981-01-01

365

Einstein’s field equations  

Microsoft Academic Search

Summary  The nature of a static line element in the relativity theory is investigated and it is shown that both the force and the torque\\u000a on an isolated body must vanish if the field equations for empty space are to have a static solution in its neighbourhood.\\u000a It is also shown how a general solution for a static electro-gravitational field can

S. Datta Majumdar

1959-01-01

366

Flares and changing magnetic fields  

Microsoft Academic Search

An observational study of maps of the longitudinal component of the photospheric fields in flaring active regions leads to the following conclusions:(1)The broad-wing Ha kernels characteristic of the impulsive phase of flares occur within 10? of neutral lines encircling features of isolated magnetic polarity (‘satellite sunspots’).(2)Photospheric field changes intimately associated with several importance 1 flares and one importance 2B flare

David M. Rust

1972-01-01

367

High voltage isolation transformer  

NASA Technical Reports Server (NTRS)

A high voltage isolation transformer is provided with primary and secondary coils separated by discrete electrostatic shields from the surfaces of insulating spools on which the coils are wound. The electrostatic shields are formed by coatings of a compound with a low electrical conductivity which completely encase the coils and adhere to the surfaces of the insulating spools adjacent to the coils. Coatings of the compound also line axial bores of the spools, thereby forming electrostatic shields separating the spools from legs of a ferromagnetic core extending through the bores. The transformer is able to isolate a high constant potential applied to one of its coils, without the occurrence of sparking or corona, by coupling the coatings, lining the axial bores to the ferromagnetic core and by coupling one terminal of each coil to the respective coating encasing the coil.

Clatterbuck, C. H.; Ruitberg, A. P. (inventors)

1985-01-01

368

Bacillus odysseyi isolate  

NASA Technical Reports Server (NTRS)

The present invention relates to discovery and isolation of a biologically pure culture of a Bacillus odysseyi isolate with high adherence and sterilization resistant properties. B. odysseyi is a round spore forming Bacillus species that produces an exosporium. This novel species has been characterized on the basis of phenotypic traits, 16S rDNA sequence analysis and DNA-DNA hybridization. According to the results of these analyses, this strain belongs to the genus Bacillus and the type strain is 34hs-1.sup.T (=ATCC PTA-4993.sup.T=NRRL B-30641.sup.T=NBRC 100172.sup.T). The GenBank accession number for the 16S rDNA sequence of strain 34hs-1.sup.T is AF526913.

Venkateswaran, Kasthuri (Inventor); La Duc, Myron Thomas (Inventor)

2007-01-01

369

DNA Isolation from Onion  

NSDL National Science Digital Library

Many students find studying DNA difficult because it is so small that the concepts are quite abstract. This lab enables students to work with DNA concretely by easily isolating chromosomal DNA using the same basic tools and methods that scientists use. The lab is a good introduction to using pipets and to using the metric system. If the chemistry of the solutions is taught it is also a great practical application.

Kate Dollard (Cambridge Rindge and Latin REV)

1994-07-30

370

Isolated polycystic liver disease.  

PubMed

Isolated polycystic liver disease (PCLD) is an autosomal dominant disease with genetic and clinical heterogeneity. Apart from liver cysts, it exhibits few extrahepatic manifestations, and the majority of patients with this condition are asymptomatic or subclinical. However, a small fraction of these patients develop acute liver cyst-related complications and/or massive cystic liver enlargement, causing morbidity and mortality. Currently, the management for symptomatic PCLD is centered on palliating symptoms and treating complications. PMID:20219621

Qian, Qi

2010-03-01

371

ISOLATED POLYCYSTIC LIVER DISEASE  

PubMed Central

Isolated polycystic liver disease (PCLD) is an autosomal dominant disease with genetic and clinical heterogeneity. Apart from liver cysts, it exhibits few extra-hepatic manifestations and the majority of patients with this condition are asymptomatic or subclinical. However, a small fraction of these patients develop acute liver-cyst-related complications and/or massive cystic liver enlargement, causing morbidity and mortality. Currently, the management for symptomatic PCLD is centered on palliating symptoms and treating complications.

Qian, Qi

2010-01-01

372

Isolated Coccygeal Tuberculosis  

PubMed Central

Isolated tuberculosis of the coccyx is extremely rare. A 35-year-old man presented with a 3-month history of coccygeal and gluteal pain. Computed tomography and magnetic resonance imaging revealed osseous destruction and a large enhancing mass involving the coccyx with anterior and posterior extension. Pathologic examination of the surgical specimen revealed necrosis, chronic granulomatous inflammation, and multinucleated giant cells consistent with tuberculosis. This case highlights the importance of considering tuberculosis as a diagnosis even though unusual sites are involved.

Kim, Do Un; Ju, Chang IL

2012-01-01

373

Enrichment culture can bias the isolation of Campylobacter subtypes.  

PubMed

Enrichment culture is often used to isolate Campylobacter. This study compared isolation of Campylobacter spp. from 119 broiler chicken environments from two farms, using Preston and modified Exeter (mExeter) and modified Bolton (mBolton) enrichments. mExeter was significantly more effective in isolating Campylobacter spp. from the environmental samples compared to Preston (P<0.001) and mBolton (P<0.04) broths but there was no significant difference between the latter two methods (P>0.05). Enrichment broth type did not affect isolation from chicken faecal or soil and litter samples. C. jejuni was isolated from significantly more environmental samples using mExeter broth compared to Preston (P<0.01) and mBolton (P<0.003) broths; there was no difference between the latter two methods or between all methods for detection of C. coli (P>0.05). Only C. coli was isolated from the soil and litter samples and although both C. jejuni and C. coli were recovered from the faecal samples there was no effect of using different enrichment broths. The majority of samples where the same species had been isolated yielded the same or closely related genotypes as defined by pulsed-field gel electrophoresis. Isolates recovered using Preston and mBolton broths were less genetically diverse than those from mExeter broth. We conclude that the enrichment method used affects both the number and species of Campylobacter isolated from naturally contaminated samples. PMID:21923970

Williams, L K; Sait, L C; Cogan, T A; Jørgensen, F; Grogono-Thomas, R; Humphrey, T J

2012-07-01

374

AMIGA Project: Quantification of the Isolation of 950 CIG galaxies  

NASA Astrophysics Data System (ADS)

The role of the environment on galaxy evolution is still not fully understood. In order to quantify and set limits on the role of nurture one must identify and study a sample of isolated galaxies. The AMIGA project "Analysis of the Interstellar Medium of Isolated GAlaxies" is doing a multi-wavelength study of a large sample of isolated galaxies in order to examine their interstellar medium and star formation activity. We processed data for 950 galaxies from the Catalogue of Isolated Galaxies (CIG, Karachentseva 1973) and evaluated their isolation using an automated star-galaxy classification procedure (down to MB ˜ 17.5) on large digitised POSS-I fields surrounding each isolated galaxy (within a projected radius of at least 0.5 Mpc). We defined, compared and discussed various criteria to quantify the degree of isolation for these galaxies: e.g. Karachentseva’s revised criterion, local surface density computations, estimation of the external tidal force affecting each is olated galaxy. We found galaxies violating Karachentseva’s original criterion, and we defined various subsamples of galaxies according to their degree of isolation. Additionally, we sought for the redshifts of the primary and companion galaxies to access the radial dimension. We also applied our pipeline to triplets, compact groups and clusters and interpret the isolated galaxy population in light of these control samples.

Verley, S.; Leon, S.; Verdes-Montenegro, L.; Combes, F.; Sabater, J.; Sulentic, J.; Bergond, G.; Espada, D.; Lisenfeld, U.; Odewahn, S. C.

2010-10-01

375

Vaccine efficacy against Ontario isolates of infectious bronchitis virus.  

PubMed

Infectious bronchitis (IB) is an economically important viral disease with worldwide distribution. Every country with an intensive poultry industry has infectious bronchitis virus (IBV). The virus rapidly spreads from bird to bird through horizontal transmission by aerosol or ingestion. Sentinel bird studies were carried out in southern Ontario and IBV has been isolated from layer flocks. Genetic analysis of the S1 region of the strains showed that they were not vaccine related. The pathogenicity of selected Ontario variants of IBV isolates was studied and the subsequent work was to determine the degree of protection against field isolates provided by a commonly used vaccine MILDVAC-Ma5 in Ontario. The protection was evaluated by challenging immunized chickens with the respiratory (IBV-ON1) and nephropathogenic (IBV-ON4) viruses. The mean vaccine efficacy for IBV-ON1 was 66.7% indicating that a Massachusetts serotype vaccine would provide some protection against IBV field isolates. PMID:19794894

Grgi?, Helena; Hunter, D Bruce; Hunton, Peter; Nagy, Eva

2009-07-01

376

Vaccine efficacy against Ontario isolates of infectious bronchitis virus  

PubMed Central

Infectious bronchitis (IB) is an economically important viral disease with worldwide distribution. Every country with an intensive poultry industry has infectious bronchitis virus (IBV). The virus rapidly spreads from bird to bird through horizontal transmission by aerosol or ingestion. Sentinel bird studies were carried out in southern Ontario and IBV has been isolated from layer flocks. Genetic analysis of the S1 region of the strains showed that they were not vaccine related. The pathogenicity of selected Ontario variants of IBV isolates was studied and the subsequent work was to determine the degree of protection against field isolates provided by a commonly used vaccine MILDVAC-Ma5 in Ontario. The protection was evaluated by challenging immunized chickens with the respiratory (IBV-ON1) and nephropathogenic (IBV-ON4) viruses. The mean vaccine efficacy for IBV-ON1 was 66.7% indicating that a Massachusetts serotype vaccine would provide some protection against IBV field isolates.

Grgic, Helena; Hunter, D. Bruce; Hunton, Peter; Nagy, Eva

2009-01-01

377

Magnetic Fields  

NSDL National Science Digital Library

Students visualize the magnetic field of a strong permanent magnet using a compass. The lesson begins with an analogy to the effect of the earth's magnetic field on a compass. Students see the connection that the compass simply responds to the earth's magnetic field since it is the closest, strongest field, and therefore the compass will respond to the field of the permanent magnets, allowing them the ability to map the field of that magnet in the activity. This information will be important in designing a solution to the grand challenge in activity 4 of the unit.

Vu Bioengineering Ret Program

378

Molecular Typing of Aeromonas Isolates in Natural Mineral Waters  

PubMed Central

A total of 103 isolates of Aeromonas spp. were obtained over a 3-year period from a natural mineral water and from surface streams located within the boundaries of the watershed of the natural mineral water wells and were typed by macrorestriction analysis of genomic DNA with XbaI and by pulsed-field gel electrophoresis. All Aeromonas caviae isolates from the natural mineral water belonged to the same clone, and an analogous clonal identity was found among Aeromonas hydrophila isolates. These two clones expressed no hemolytic or cytotoxic activities. Aeromonas isolates from surface waters showed high molecular heterogeneity and were not related to the clones found in the natural mineral water. The presence of aeromonads chronically found in the natural mineral water was a likely consequence of a localized development of a biofilm, with no exogenous contamination of the aquifer. Molecular fingerprinting of drinking water isolates is a useful tool in explaining possible reasons for bacterial occurrences.

Villari, P.; Crispino, M.; Montuori, P.; Boccia, S.

2003-01-01

379

Geographical Isolation Factors: The Literature.  

ERIC Educational Resources Information Center

Drawn from a larger paper on geographical isolation, these pages present a review of literature pertaining to geographical isolation factors. The inclusion of a geographical isolation factor in a state's distribution formula for foundation aid is a mechanism for providing additional revenue to small schools or school districts that, because of…

Bass, Gerald R.

380

Genetic and biological variations among Plutella xylostella granulovirus isolates  

Microsoft Academic Search

Success of a baculovirus in the field depends on the selection and utilization of effective isolates of viruses with increased\\u000a pathogenicity and virulence. Isolates ofPlutella xylostella granuloviruses collected from Kenya and India were compared for genetic variations by restriction endonuclease enzyme analysis\\u000a and for biological activity based on their median lethal concentration and time-to-kill early- and late-third instars. TheP. xylostella

S. Subramanian; R. J. Rabindra; S. Sithanantham

2008-01-01

381

Hollow-cylinder waveguide isolators for use at millimeter wavelengths  

NASA Technical Reports Server (NTRS)

The device considered in this study is a semiconductor waveguide isolator consisting of a hollow column of a semiconductor mounted coaxially in a circular waveguide in a longitudinal dc magnetic field. An elementary and physical analysis based on the excitation of plane waves in the guide and a more rigorous mode-matching analysis (MMA) are presented. These theoretical predictions are compared with experimental results for an InSb isolator at 94 GHz and 75 K.

Kanda, M.; May, W. G.

1974-01-01

382

Molecular characterization of Mycoplasma gallisepticum isolates from turkeys.  

PubMed

Mycoplasma gallisepticum was isolated from several turkey flocks at different locations in the United States that were clinically affected with respiratory disease. Five of these isolates from four series of outbreaks had patterns similar to the 6/85 vaccine strain of M. gallisepticum by random amplified polymorphic DNA (RAPD) analysis using three different primer sets, whereas with a fourth primer set (OPA13 and OPA14), only two of the isolates were similar to 6/85. Results obtained by sequencing portions of the pvpA, gapA, and mgc2 genes and an uncharacterized surface lipoprotein gene indicated that the field isolates had DNA sequences that ranged from 97.6% to 100%, similar to the 6/85 results. In some of the outbreaks there was an indirect association with the presence of commercial layers in the area that had been vaccinated with this vaccine strain, but there was no known close association with vaccinated birds in any of the outbreaks. Turkeys were challenged with two of the field isolates and with 6/85 vaccine strain. Turkeys challenged with the field isolates developed respiratory disease with airsacculitis and a typical M. gallisepticum antibody response, whereas birds challenged with 6/85 developed no respiratory signs or lesions and developed only a weak antibody response. Although these isolates were very similar to the 6/85 vaccine strain, it was not possible to prove that they originated from the vaccine strain-it is possible that they could be naturally occurring field isolates. PMID:15529978

Kleven, S H; Fulton, R M; García, M; Ikuta, V N; Leiting, V A; Liu, T; Ley, D H; Opengart, K N; Rowland, G N; Wallner-Pendleton, E

2004-09-01

383

Visual field  

MedlinePLUS

Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... a map of your entire peripheral vision. Automated perimetry: You sit in front of a concave dome ...

384

The NASA Langley Isolator Dynamics Research Lab  

NASA Technical Reports Server (NTRS)

The Isolator Dynamics Research Lab (IDRL) is under construction at the NASA Langley Research Center in Hampton, Virginia. A unique test apparatus is being fabricated to support both wall and in-stream measurements for investigating the internal flow of a dual-mode scramjet isolator model. The test section is 24 inches long with a 1-inch by 2-inch cross sectional area and is supplied with unheated, dry air through a Mach 2.5 converging-diverging nozzle. The test section is being fabricated with two sets (glass and metallic) of interchangeable sidewalls to support flow visualization and laser-based measurement techniques as well as static pressure, wall temperature, and high frequency pressure measurements. During 2010, a CFD code validation experiment will be conducted in the lab in support of NASA s Fundamental Aerodynamics Program. This paper describes the mechanical design of the Isolator Dynamics Research Lab test apparatus and presents a summary of the measurement techniques planned for investigating the internal flow field of a scramjet isolator model.

Middleton, Troy F.; Balla, Robert J.; Baurle, Robert A.; Humphreys, William M.; Wilson, Lloyd G.

2010-01-01

385

Isolation of Circulating Tumor Cells by Dielectrophoresis  

PubMed Central

Dielectrophoresis (DEP) is an electrokinetic method that allows intrinsic dielectric properties of suspended cells to be exploited for discrimination and separation. It has emerged as a promising method for isolating circulation tumor cells (CTCs) from blood. DEP-isolation of CTCs is independent of cell surface markers. Furthermore, isolated CTCs are viable and can be maintained in culture, suggesting that DEP methods should be more generally applicable than antibody-based approaches. The aim of this article is to review and synthesize for both oncologists and biomedical engineers interested in CTC isolation the pertinent characteristics of DEP and CTCs. The aim is to promote an understanding of the factors involved in realizing DEP-based instruments having both sufficient discrimination and throughput to allow routine analysis of CTCs in clinical practice. The article brings together: (a) the principles of DEP; (b) the biological basis for the dielectric differences between CTCs and blood cells; (c) why such differences are expected to be present for all types of tumors; and (d) instrumentation requirements to process 10 mL blood specimens in less than 1 h to enable routine clinical analysis. The force equilibrium method of dielectrophoretic field-flow fractionation (DEP-FFF) is shown to offer higher discrimination and throughput than earlier DEP trapping methods and to be applicable to clinical studies.

Gascoyne, Peter R. C.; Shim, Sangjo

2014-01-01

386

Silicon ring isolators with bonded nonreciprocal magneto-optic garnets.  

PubMed

A ring isolator is demonstrated for the first time by directly bonding a cerium-substituted yttrium iron garnet (Ce:YIG) onto a silicon ring resonator using oxygen plasma enhanced bonding. The silicon waveguide is 600 nm wide and 295 nm thick with 500-nm-thick Ce:YIG on the top to have reasonable nonreciprocal effect and low optical loss. With a radial magnetic field applied to the ring isolator, it exhibits 9-dB isolation at resonance in the 1550 nm wavelength regime. PMID:21716405

Tien, Ming-Chun; Mizumoto, Tetsuya; Pintus, Paolo; Kromer, Herbert; Bowers, John E

2011-06-01

387

Electrophoretic karyotypes of clinical isolates of Coccidioides immitis.  

PubMed Central

Chromosomes of the fungal respiratory pathogen, Coccidioides immitis, were separated by contour-clamped homogeneous electric field gel electrophoresis. Twelve isolates were examined, the majority of which showed four chromosomes with a range of molecular size from 11.5 to 3.2 Mb. Three isolates (C634, C735, and L) revealed three chromosomal bands under the conditions employed for electrophoretic separation. However, in two of these isolates (C634 and C735), four chromosomes were visible on membrane transfers of pulsed-field gels after Southern hybridization between the chromosomal DNA and selected DNA probes. The probes included a conserved ribosomal gene and three previously described cDNAs isolated from C. immitis expression libraries. The L isolate was determined to have the same genome size as a typical four-chromosome isolate on the basis of microspectrophotometric comparison of fluorescence intensity of the ethidium bromide-stained nuclear DNA. The genome size of C. immitis determined by microspectrophotometry was approximately 28.2 +/- 2.6 Mb. The calculated genome size based on addition of the average molecular weights of chromosomal bands separated by contour-clamped homogeneous electric field gel electrophoresis was approximately equal to the estimate derived from the spectrophotometric analyses. This is the first report of the electrophoretic karyotype of C. immitis. Images

Pan, S; Cole, G T

1992-01-01

388

Genetic Characterization of Rabies Field Isolates from Venezuela  

Microsoft Academic Search

Twenty samples from cases of rabies in humans and domestic animals diagnosed in Venezuela between 1990 and 1994 and one sample from a vampire bat collected in 1976 were characterized by reactivity to monoclonal antibodiesagainsttheviralnucleoproteinandbypatternsofnucleotidesubstitutioninthenucleoproteingene. Three antigenic variants were found: 1, 3, and 5. Antigenic variant 1 included all samples from dogs and humans infected by contact with rabid dogs.

CARLOS A. DEMATTOS; CECILIA C. DEMATTOS; JEAN S. SMITH; EDITH T. MILLER; SARA PAPO; ANTONIO UTRERA; ANDBENNIE I. OSBURN

389

High performance rotational vibration isolator  

NASA Astrophysics Data System (ADS)

We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 +/- 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

Sunderland, Andrew; Blair, David G.; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

2013-10-01

390

Powdery mildew (Leveillula taurica) on greenhouse and field peppers in Ontario – host range, cultivar response and disease management strategies  

Microsoft Academic Search

Leveillula taurica was observed on field pepper at various sites in south-western Ontario in 2005–2007. The field isolates collected from these sites were similar to a greenhouse isolate based on morphological observations. Host range of greenhouse and field isolates was similar, with minor sporulation on potato, carrot and several weeds. The greenhouse pepper cultivar ‘Samanta’ was the most susceptible to

R. F. Cerkauskas; G. Ferguson; M. Banik

2011-01-01

391

Impact of isolation on hospital consumer assessment of healthcare providers and systems scores: is isolation isolating?  

PubMed

The Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey was used to measure the effect of isolation on patient satisfaction. Isolated patients reported lower scores for questions regarding physician communication and staff responsiveness. Overall scores for these domains were lower in isolated than in nonisolated patients. PMID:22476279

Vinski, Joan; Bertin, Mary; Sun, Zhiyuan; Gordon, Steven M; Bokar, Daniel; Merlino, James; Fraser, Thomas G

2012-05-01

392

Computer system isolates faults  

SciTech Connect

Maintaining transaction processing systems in continuous operation, a minicomputer system made by tolerant systems detects and isolates faults, then transfers work loads to the appropriate backup resource. An eternity system is actually 1 to 15 computer systems, called system building blocks, interconnected by a communication network. Modularity is provided by tolerant's flexible architecture technique. This allows a user to expand system capacity with nondedicated computers which can be assigned to tasks such as increasing processing power, user accessibility and database size as dictated by needs. The loosely-coupled nature of the system increases reliability.

Hall, D.E.

1983-11-01

393

Investigation of mercury thruster isolators  

NASA Technical Reports Server (NTRS)

Mercury ion thruster isolator lifetime tests were performed using different isolator materials and geometries. Tests were performed with and without the flow of mercury through the isolators in an oil diffusion pumped vacuum facility and cryogenically pumped bell jar. The onset of leakage current in isolators occurred in time intervals ranging from a few hours to many hundreds of hours. In all cases, surface contamination was responsible for the onset of leakage current and subsequent isolator failure. Rate of increase of leakage current and the leakage current level increased approximately exponentially with isolator temperature. Careful attention to shielding techniques and the elimination of sources of metal oxides appear to have eliminated isolator failures as a thruster life limiting mechanism.

Mantenieks, M. A.

1973-01-01

394

Statistical comparison of isolated and non-isolated auroral substorms  

NASA Astrophysics Data System (ADS)

We present results from a superposed epoch analysis of the morphology and energy deposition of isolated and non-isolated auroral substorms. The study is based on auroral data acquired by the global ultraviolet imager (GUVI) on board the TIMED satellite and a total number of 13717 geomagnetic bay onsets identified with magnetometer data from SuperMAG and published previously by Newell and Gjerloev [2011]. Here the isolated substorms are those having separation of two consecutive onsets no less than 3 hours. While the three phases substorm are clearly shown in both isolated and non-isolated substorms, there are noticeable differences between the two types of substorms: (1) In the growth phase, the nighttime auroral power slightly increases for both types of substorms; isolated (non-isolated) substorms are associated with smaller (greater) nighttime auroral power; (2) In the expansion phase, substorm energy release is greater and more explosive for isolated than non-isolated substorms; (3) The recovery phase period is longer for isolated than for non-isolated substorms; (4) The winter-to-summer auroral power ratio is approximately constant throughout the three substorm phases and the ratio is larger for isolated (30%) than for non-isolated (20%) substorms. We also found that the polar cap area increases during the growth phase until ~10 min prior to the magnetic substorm onset and decreases rapidly after onset. The decrease is associated with the closure of the nightside auroral oval associated with substorm expansion. We found most of these differences can be related to the differences in their solar wind driving. We will present the results in detail and make a conclusion.

Liou, K.; Newell, P. T.; Zhang, Y.; Paxton, L. J.

2012-12-01

395

Isolation and characterization of mesenchymal stem cells.  

PubMed

Mesenchymal stem cells (MSCs) have drawn great interest in the field of regenerative medicine, for cell replacement, immunomodulatory, and gene therapies. It has been shown that these multipotent stromal cells can be isolated from tissues such as bone marrow, adipose tissue, trimester amniotic tissue, umbilical cord blood, and deciduous teeth and can be expanded in adherent culture. They have the capacity to differentiate into cells of the connective tissue lineages in vitro and contribute to tissue parenchyma in vivo. However, proper in vitro manipulation of MSCs is a key issue to reveal a potential therapeutic benefit following transplantation into the patients. This chapter summarizes some of the essential protocols and assays used at our laboratory for the isolation, culture, differentiation, and characterization of mesenchymal stem cells from the bone marrow and adipose tissue. PMID:24473777

Odabas, Sedat; Elçin, A Eser; Elçin, Y Murat

2014-01-01

396