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Sample records for resistance determinant widely

  1. Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Leng, Bingfeng; Haaber, Jakob

    2016-01-01

    The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products...... that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We...... with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets...

  2. Nickel-resistance determinants in Acidiphilium sp. PM identified by genome-wide functional screening.

    Directory of Open Access Journals (Sweden)

    Patxi San Martin-Uriz

    Full Text Available Acidiphilium spp. are conspicuous dwellers of acidic, metal-rich environments. Indeed, they are among the most metal-resistant organisms; yet little is known about the mechanisms behind the metal tolerance in this genus. Acidiphilium sp. PM is an environmental isolate from Rio Tinto, an acidic, metal-laden river located in southwestern Spain. The characterization of its metal resistance revealed a remarkable ability to tolerate high Ni concentrations. Here we report the screening of a genomic library of Acidiphilium sp. PM to identify genes involved in Ni resistance. This approach revealed seven different genes conferring Ni resistance to E. coli, two of which form an operon encoding the ATP-dependent protease HslVU (ClpQY. This protease was found to enhance resistance to both Ni and Co in E. coli, a function not previously reported. Other Ni-resistance determinants include genes involved in lipopolysaccharide biosynthesis and the synthesis of branched amino acids. The diversity of molecular functions of the genes recovered in the screening suggests that Ni resistance in Acidiphilium sp. PM probably relies on different molecular mechanisms.

  3. Genome-wide identification of antimicrobial intrinsic resistance determinants in Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Martin Vestergaard

    2016-12-01

    Full Text Available The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin and gentamicin. 68 mutants were confirmed by E-test to display at least two-fold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.

  4. NOVEL ANTIBIOTIC RESISTANCE DETERMINANTS FROM AGRICULTURAL SOIL EXPOSED TO ANTIBIOTICS WIDELY USED IN HUMAN MEDICINE AND ANIMAL FARMING.

    Science.gov (United States)

    Lau, Calvin Ho-Fung; van Engelen, Kalene; Gordon, Stephen; Renaud, Justin; Topp, Edward

    2017-06-16

    Antibiotic resistance has emerged globally as one of the biggest threats to human and animal health. Although the excessive use of antibiotics is recognized for accelerating the selection for resistance, there is a growing body of evidence suggesting that natural environments are "hotspots" for the development of both ancient and contemporary resistance mechanisms. Given that pharmaceuticals can be entrained onto agricultural land through anthropogenic activities, this could be a potential driver for the emergence and dissemination of resistance in soil bacteria. Using functional metagenomics, we interrogated the "resistome" of bacterial communities found in a collection of Canadian agricultural soil, some of which had been receiving antibiotics widely used in human medicine (macrolides) or food animal production (sulfamethazine, chlortetracycline and tylosin) for up to 16 years. Of the 34 new antibiotic resistance genes (ARGs) recovered, the majority were predicted to encode for (multi)drug efflux systems, while a few share little to no homology with established resistance determinants. We characterized several novel gene products, including putative enzymes that can confer high-level resistance against aminoglycosides, sulfonamides, and broad range of beta-lactams, with respect to their resistance mechanisms and clinical significance. By coupling high-resolution proteomics analysis with functional metagenomics, we discovered an unusual peptide, PPP AZI 4 , encoded within an alternative open-reading frame not predicted by bioinformatics tools. Expression of the proline-rich PPP AZI 4 can promote resistance against different macrolides but not other ribosomal-targeting antibiotics, implicating a new macrolide-specific resistance mechanism that could be fundamentally linked to the evolutionary design of this peptide. IMPORTANCE Antibiotic resistance is a clinical phenomenon with an evolutionary link to the microbial pangenome. Genes and protogenes encoding for

  5. Novel Antibiotic Resistance Determinants from Agricultural Soil Exposed to Antibiotics Widely Used in Human Medicine and Animal Farming

    OpenAIRE

    Lau, Calvin Ho-Fung; van Engelen, Kalene; Gordon, Stephen; Renaud, Justin; Topp, Edward

    2017-01-01

    Antibiotic resistance has emerged globally as one of the biggest threats to human and animal health. Although the excessive use of antibiotics is recognized as accelerating the selection for resistance, there is a growing body of evidence suggesting that natural environments are “hot spots” for the development of both ancient and contemporary resistance mechanisms. Given that pharmaceuticals can be entrained onto agricultural land through anthropogenic activities, this could be a potential dr...

  6. Genetic diversity for Russian wheat aphid resistance as determined by genome-wide association mapping and inheritance in progeny

    Science.gov (United States)

    Russian wheat aphid (RWA) is an increasing problem on barley throughout the world. Genetic resistance has been identified and used to create barley germplasm and cultivars adapted to the US. Several mapping studies have been conducted to identify loci associated with resistance, but questions remain...

  7. The wide gap resistive plate chamber

    International Nuclear Information System (INIS)

    Crotty, I.; Lamas Valverde, J.; Hatzifotiadou, D.; Williams, M.C.S.; Zichichi, A.

    1995-01-01

    The resistive plate chamber (RPC) has good time and position resolution; these factors (coupled to its simple construction) make it an attractive candidate for muon trigger systems at future colliders. However, operated in spark mode, the RPC has severe rate problems that make it unusable above 10 Hz/cm 2 . We have previously published our results concerning the operation of the RPC in spark and in avalanche mode; we have shown that the rate limit can be increased to 150 Hz/cm 2 if the RPC is operated in avalanche mode. Here, we discuss the performance of chambers with 6 and 8 mm gas gaps (compared to the more usual 2 mm gap). We outline the reasons for this choice, and also discuss anode versus cathode strip readout. We have measured the efficiency versus flux, and also show that an enhanced rate limit can be obtained if only a small region of the chamber is exposed to the beam (spot illumination). Finally we have tested the performance of chambers constructed with other materials for the resistiv e plate and compare it to chambers constructed with our preferred plastic, melamine laminate. (orig.)

  8. Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis

    KAUST Repository

    Coll, Francesc; Phelan, Jody; Hill-Cawthorne, Grant A.; Nair, Mridul; Mallard, Kim; Ali, Shahjahan; Abdallah, Abdallah; Alghamdi, Saad; Alsomali, Mona; Ahmed, Abdallah O.; Portelli, Stephanie; Oppong, Yaa; Alves, Adriana; Bessa, Theolis Barbosa; Campino, Susana; Caws, Maxine; Chatterjee, Anirvan; Crampin, Amelia C.; Dheda, Keertan; Furnham, Nicholas; Glynn, Judith R.; Grandjean, Louis; Minh Ha, Dang; Hasan, Rumina; Hasan, Zahra; Hibberd, Martin L.; Joloba, Moses; Jones-Ló pez, Edward C.; Matsumoto, Tomoshige; Miranda, Anabela; Moore, David J.; Mocillo, Nora; Panaiotov, Stefan; Parkhill, Julian; Penha, Carlos; Perdigã o, Joã o; Portugal, Isabel; Rchiad, ‍ Zineb; Robledo, Jaime; Sheen, Patricia; Shesha, Nashwa Talaat; Sirgel, Frik A.; Sola, Christophe; Oliveira Sousa, Erivelton; Streicher, Elizabeth M.; Helden, Paul Van; Viveiros, Miguel; Warren, Robert M.; McNerney, Ruth; Pain, Arnab; Clark, Taane G.

    2018-01-01

    To characterize the genetic determinants of resistance to antituberculosis drugs, we performed a genome-wide association study (GWAS) of 6,465 Mycobacterium tuberculosis clinical isolates from more than 30 countries. A GWAS approach within a mixed

  9. The determinants of the antibiotic resistance process.

    Science.gov (United States)

    Franco, Beatriz Espinosa; Altagracia Martínez, Marina; Sánchez Rodríguez, Martha A; Wertheimer, Albert I

    2009-01-01

    The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community. To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem. We conducted a MedLine search using the key words "determinants", "antibiotic", and "antibiotic resistance" to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded. The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance. Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.

  10. Determining the specific electric resistance of rock

    Energy Technology Data Exchange (ETDEWEB)

    Persad' ko, V.Ia.

    1982-01-01

    Data are presented on perfecting the method of laboratory determination of the specific electric resistance of a rock formation. The average error in determining the specific electric resistance of the core at various locations is no more than two percent with low resistance values (2-5 ohms).

  11. Radiation resistance of wide-bandgap semiconductor power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Hazdra, Pavel; Popelka, Stanislav [Department of Microelectronics, Czech Technical University in Prague (Czech Republic)

    2017-04-15

    Radiation resistance of state-of-the-art commercial wide-bandgap power transistors, 1700 V 4H-SiC power MOSFETs and 200 V GaN HEMTs, to the total ionization dose was investigated. Transistors were irradiated with 4.5 MeV electrons with doses up to 2000 kGy. Electrical characteristics and introduced defects were characterized by current-voltage (I-V), capacitance-voltage (C-V), and deep level transient spectroscopy (DLTS) measurements. Results show that already low doses of 4.5 MeV electrons (>1 kGy) cause a significant decrease in threshold voltage of SiC MOSFETs due to embedding of the positive charge into the gate oxide. On the other hand, other parameters like the ON-state resistance are nearly unchanged up to the dose of 20 kGy. At 200 kGy, the threshold voltage returns back close to its original value, however, the ON-state resistance increases and transconductance is lowered. This effect is caused by radiation defects introduced into the low-doped drift region which decrease electron concentration and mobility. GaN HEMTs exhibit significantly higher radiation resistance. They keep within the datasheet specification up to doses of 2000 kGy. Absence of dielectric layer beneath the gate and high concentration of carriers in the two dimensional electron gas channel are the reasons of higher radiation resistance of GaN HEMTs. Their degradation then occurs at much higher doses due to electron mobility degradation. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Novel Cadmium Resistance Determinant in Listeria monocytogenes.

    Science.gov (United States)

    Parsons, Cameron; Lee, Sangmi; Jayeola, Victor; Kathariou, Sophia

    2017-03-01

    Listeria monocytogenes is a foodborne pathogen that can cause severe disease (listeriosis) in susceptible individuals. It is ubiquitous in the environment and often exhibits resistance to heavy metals. One of the determinants that enables Listeria to tolerate exposure to cadmium is the cadAC efflux system, with CadA being a P-type ATPase. Three different cadA genes (designated cadA1 to cadA3 ) were previously characterized in L. monocytogenes A novel putative cadmium resistance gene ( cadA4 ) was recently identified through whole-genome sequencing, but experimental confirmation for its involvement in cadmium resistance is lacking. In this study, we characterized cadA4 in L. monocytogenes strain F8027, a cadmium-resistant strain of serotype 4b. By screening a mariner-based transposon library of this strain, we identified a mutant with reduced tolerance to cadmium and that harbored a single transposon insertion in cadA4 The tolerance to cadmium was restored by genetic complementation with the cadmium resistance cassette ( cadA4C ), and enhanced cadmium tolerance was conferred to two unrelated cadmium-sensitive strains via heterologous complementation with cadA4C Cadmium exposure induced cadA4 expression, even at noninhibitory levels. Virulence assessments in the Galleria mellonella model suggested that a functional cadA4 suppressed virulence, potentially promoting commensal colonization of the insect larvae. Biofilm assays suggested that cadA4 inactivation reduced biofilm formation. These data not only confirm cadA4 as a novel cadmium resistance determinant in L. monocytogenes but also provide evidence for roles in virulence and biofilm formation. IMPORTANCE Listeria monocytogenes is an intracellular foodborne pathogen causing the disease listeriosis, which is responsible for numerous hospitalizations and deaths every year. Among the adaptations that enable the survival of Listeria in the environment are the abilities to persist in biofilms, grow in the cold, and

  13. Genome-wide deficiency screen for the genomic regions responsible for heat resistance in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Teramura Kouhei

    2011-06-01

    Full Text Available Abstract Background Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. Results To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. Conclusion The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.

  14. Distribution of triclosan-resistant genes in major pathogenic microorganisms revealed by metagenome and genome-wide analysis

    Science.gov (United States)

    Khan, Raees; Roy, Nazish; Choi, Kihyuck

    2018-01-01

    The substantial use of triclosan (TCS) has been aimed to kill pathogenic bacteria, but TCS resistance seems to be prevalent in microbial species and limited knowledge exists about TCS resistance determinants in a majority of pathogenic bacteria. We aimed to evaluate the distribution of TCS resistance determinants in major pathogenic bacteria (N = 231) and to assess the enrichment of potentially pathogenic genera in TCS contaminated environments. A TCS-resistant gene (TRG) database was constructed and experimentally validated to predict TCS resistance in major pathogenic bacteria. Genome-wide in silico analysis was performed to define the distribution of TCS-resistant determinants in major pathogens. Microbiome analysis of TCS contaminated soil samples was also performed to investigate the abundance of TCS-resistant pathogens. We experimentally confirmed that TCS resistance could be accurately predicted using genome-wide in silico analysis against TRG database. Predicted TCS resistant phenotypes were observed in all of the tested bacterial strains (N = 17), and heterologous expression of selected TCS resistant genes from those strains conferred expected levels of TCS resistance in an alternative host Escherichia coli. Moreover, genome-wide analysis revealed that potential TCS resistance determinants were abundant among the majority of human-associated pathogens (79%) and soil-borne plant pathogenic bacteria (98%). These included a variety of enoyl-acyl carrier protein reductase (ENRs) homologues, AcrB efflux pumps, and ENR substitutions. FabI ENR, which is the only known effective target for TCS, was either co-localized with other TCS resistance determinants or had TCS resistance-associated substitutions. Furthermore, microbiome analysis revealed that pathogenic genera with intrinsic TCS-resistant determinants exist in TCS contaminated environments. We conclude that TCS may not be as effective against the majority of bacterial pathogens as previously presumed

  15. Distribution of triclosan-resistant genes in major pathogenic microorganisms revealed by metagenome and genome-wide analysis.

    Directory of Open Access Journals (Sweden)

    Raees Khan

    Full Text Available The substantial use of triclosan (TCS has been aimed to kill pathogenic bacteria, but TCS resistance seems to be prevalent in microbial species and limited knowledge exists about TCS resistance determinants in a majority of pathogenic bacteria. We aimed to evaluate the distribution of TCS resistance determinants in major pathogenic bacteria (N = 231 and to assess the enrichment of potentially pathogenic genera in TCS contaminated environments. A TCS-resistant gene (TRG database was constructed and experimentally validated to predict TCS resistance in major pathogenic bacteria. Genome-wide in silico analysis was performed to define the distribution of TCS-resistant determinants in major pathogens. Microbiome analysis of TCS contaminated soil samples was also performed to investigate the abundance of TCS-resistant pathogens. We experimentally confirmed that TCS resistance could be accurately predicted using genome-wide in silico analysis against TRG database. Predicted TCS resistant phenotypes were observed in all of the tested bacterial strains (N = 17, and heterologous expression of selected TCS resistant genes from those strains conferred expected levels of TCS resistance in an alternative host Escherichia coli. Moreover, genome-wide analysis revealed that potential TCS resistance determinants were abundant among the majority of human-associated pathogens (79% and soil-borne plant pathogenic bacteria (98%. These included a variety of enoyl-acyl carrier protein reductase (ENRs homologues, AcrB efflux pumps, and ENR substitutions. FabI ENR, which is the only known effective target for TCS, was either co-localized with other TCS resistance determinants or had TCS resistance-associated substitutions. Furthermore, microbiome analysis revealed that pathogenic genera with intrinsic TCS-resistant determinants exist in TCS contaminated environments. We conclude that TCS may not be as effective against the majority of bacterial pathogens as previously

  16. The determinants of the antibiotic resistance process

    Directory of Open Access Journals (Sweden)

    Beatriz Espinosa Franco

    2009-04-01

    Full Text Available Beatriz Espinosa Franco1, Marina Altagracia Martínez2, Martha A Sánchez Rodríguez1, Albert I Wertheimer31Facultad de Estudios Superiores Zaragoza (UNAM, Mexico; 2Universidad Autónoma Metropolitana Unidad Xochimilco, Mexico; 3Temple University, Philadelphia, Pennsylvania, USABackground: The use of antibiotic drugs triggers a complex interaction involving many biological, sociological, and psychological determinants. Resistance to antibiotics is a serious worldwide problem which is increasing and has implications for morbidity, mortality, and health care both in hospitals and in the community.Objectives: To analyze current research on the determinants of antibiotic resistance and comprehensively review the main factors in the process of resistance in order to aid our understanding and assessment of this problem.Methods: We conducted a MedLine search using the key words “determinants”, “antibiotic”, and “antibiotic resistance” to identify publications between 1995 and 2007 on the determinants of antibiotic resistance. Publications that did not address the determinants of antibiotic resistance were excluded.Results: The process and determinants of antibiotic resistance are described, beginning with the development of antibiotics, resistance and the mechanisms of resistance, sociocultural determinants of resistance, the consequences of antibiotic resistance, and alternative measures proposed to combat antibiotic resistance.Conclusions: Analysis of the published literature identified the main determinants of antibiotic resistance as irrational use of antibiotics in humans and animal species, insufficient patient education when antibiotics are prescribed, lack of guidelines for treatment and control of infections, lack of scientific information for physicians on the rational use of antibiotics, and lack of official government policy on the rational use of antibiotics in public and private hospitals.Keywords: antibiotic drug resistance

  17. Genome-wide analysis of multi- and extensively drug-resistant Mycobacterium tuberculosis

    KAUST Repository

    Coll, Francesc

    2018-01-16

    To characterize the genetic determinants of resistance to antituberculosis drugs, we performed a genome-wide association study (GWAS) of 6,465 Mycobacterium tuberculosis clinical isolates from more than 30 countries. A GWAS approach within a mixed-regression framework was followed by a phylogenetics-based test for independent mutations. In addition to mutations in established and recently described resistance-associated genes, novel mutations were discovered for resistance to cycloserine, ethionamide and para-aminosalicylic acid. The capacity to detect mutations associated with resistance to ethionamide, pyrazinamide, capreomycin, cycloserine and para-aminosalicylic acid was enhanced by inclusion of insertions and deletions. Odds ratios for mutations within candidate genes were found to reflect levels of resistance. New epistatic relationships between candidate drug-resistance-associated genes were identified. Findings also suggest the involvement of efflux pumps (drrA and Rv2688c) in the emergence of resistance. This study will inform the design of new diagnostic tests and expedite the investigation of resistance and compensatory epistatic mechanisms.

  18. Convergent acquisition of antibiotic resistance determinants ...

    African Journals Online (AJOL)

    Convergent acquisition of antibiotic resistance determinants amongst the Enterobacteriaceae isolates of the Mhlathuze River, KwaZulu-Natal (RSA) ... The possibility of transmission of resistant genes between bacteria (especially pathogenic) which invade human and animal populations within this river poses a health risk ...

  19. Bacterial charity work leads to population-wide resistance.

    Science.gov (United States)

    Lee, Henry H; Molla, Michael N; Cantor, Charles R; Collins, James J

    2010-09-02

    Bacteria show remarkable adaptability in the face of antibiotic therapeutics. Resistance alleles in drug target-specific sites and general stress responses have been identified in individual end-point isolates. Less is known, however, about the population dynamics during the development of antibiotic-resistant strains. Here we follow a continuous culture of Escherichia coli facing increasing levels of antibiotic and show that the vast majority of isolates are less resistant than the population as a whole. We find that the few highly resistant mutants improve the survival of the population's less resistant constituents, in part by producing indole, a signalling molecule generated by actively growing, unstressed cells. We show, through transcriptional profiling, that indole serves to turn on drug efflux pumps and oxidative-stress protective mechanisms. The indole production comes at a fitness cost to the highly resistant isolates, and whole-genome sequencing reveals that this bacterial altruism is made possible by drug-resistance mutations unrelated to indole production. This work establishes a population-based resistance mechanism constituting a form of kin selection whereby a small number of resistant mutants can, at some cost to themselves, provide protection to other, more vulnerable, cells, enhancing the survival capacity of the overall population in stressful environments.

  20. Genome-Wide Association Study of Anthracnose Resistance in Andean Beans (Phaseolus vulgaris.

    Directory of Open Access Journals (Sweden)

    Grady H Zuiderveen

    Full Text Available Anthracnose is a seed-borne disease of common bean (Phaseolus vulgaris L. caused by the fungus Colletotrichum lindemuthianum, and the pathogen is cosmopolitan in distribution. The objectives of this study were to identify new sources of anthracnose resistance in a diverse panel of 230 Andean beans comprised of multiple seed types and market classes from the Americas, Africa, and Europe, and explore the genetic basis of this resistance using genome-wide association mapping analysis (GWAS. Twenty-eight of the 230 lines tested were resistant to six out of the eight races screened, but only one cultivar Uyole98 was resistant to all eight races (7, 39, 55, 65, 73, 109, 2047, and 3481 included in the study. Outputs from the GWAS indicated major quantitative trait loci (QTL for resistance on chromosomes, Pv01, Pv02, and Pv04 and two minor QTL on Pv10 and Pv11. Candidate genes associated with the significant SNPs were detected on all five chromosomes. An independent QTL study was conducted to confirm the physical location of the Co-1 locus identified on Pv01 in an F4:6 recombinant inbred line (RIL population. Resistance was determined to be conditioned by the single dominant gene Co-1 that mapped between 50.16 and 50.30 Mb on Pv01, and an InDel marker (NDSU_IND_1_50.2219 tightly linked to the gene was developed. The information reported will provide breeders with new and diverse sources of resistance and genomic regions to target in the development of anthracnose resistance in Andean beans.

  1. Genome-Wide Association Study of Anthracnose Resistance in Andean Beans (Phaseolus vulgaris).

    Science.gov (United States)

    Zuiderveen, Grady H; Padder, Bilal A; Kamfwa, Kelvin; Song, Qijian; Kelly, James D

    2016-01-01

    Anthracnose is a seed-borne disease of common bean (Phaseolus vulgaris L.) caused by the fungus Colletotrichum lindemuthianum, and the pathogen is cosmopolitan in distribution. The objectives of this study were to identify new sources of anthracnose resistance in a diverse panel of 230 Andean beans comprised of multiple seed types and market classes from the Americas, Africa, and Europe, and explore the genetic basis of this resistance using genome-wide association mapping analysis (GWAS). Twenty-eight of the 230 lines tested were resistant to six out of the eight races screened, but only one cultivar Uyole98 was resistant to all eight races (7, 39, 55, 65, 73, 109, 2047, and 3481) included in the study. Outputs from the GWAS indicated major quantitative trait loci (QTL) for resistance on chromosomes, Pv01, Pv02, and Pv04 and two minor QTL on Pv10 and Pv11. Candidate genes associated with the significant SNPs were detected on all five chromosomes. An independent QTL study was conducted to confirm the physical location of the Co-1 locus identified on Pv01 in an F4:6 recombinant inbred line (RIL) population. Resistance was determined to be conditioned by the single dominant gene Co-1 that mapped between 50.16 and 50.30 Mb on Pv01, and an InDel marker (NDSU_IND_1_50.2219) tightly linked to the gene was developed. The information reported will provide breeders with new and diverse sources of resistance and genomic regions to target in the development of anthracnose resistance in Andean beans.

  2. Prevalence and determinants of resistant hypertension among ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research ... Prevalence and determinants of resistant hypertension among hypertensive patients attending a cardiology clinic in ... Obese patients and those suffering from diabetes mellitus, ischemic heart ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  3. Electrical resistivity determination of subsurface layers, subsoil ...

    African Journals Online (AJOL)

    Electrical resistivity determination of subsurface layers, subsoil competence and soil corrosivity at and engineering site location in Akungba-Akoko, ... The study concluded that the characteristics of the earth materials in the site would be favourable to normal engineering structures/materials that may be located on it.

  4. Quantifying the Determinants of Evolutionary Dynamics Leading to Drug Resistance.

    Directory of Open Access Journals (Sweden)

    Guillaume Chevereau

    Full Text Available The emergence of drug resistant pathogens is a serious public health problem. It is a long-standing goal to predict rates of resistance evolution and design optimal treatment strategies accordingly. To this end, it is crucial to reveal the underlying causes of drug-specific differences in the evolutionary dynamics leading to resistance. However, it remains largely unknown why the rates of resistance evolution via spontaneous mutations and the diversity of mutational paths vary substantially between drugs. Here we comprehensively quantify the distribution of fitness effects (DFE of mutations, a key determinant of evolutionary dynamics, in the presence of eight antibiotics representing the main modes of action. Using precise high-throughput fitness measurements for genome-wide Escherichia coli gene deletion strains, we find that the width of the DFE varies dramatically between antibiotics and, contrary to conventional wisdom, for some drugs the DFE width is lower than in the absence of stress. We show that this previously underappreciated divergence in DFE width among antibiotics is largely caused by their distinct drug-specific dose-response characteristics. Unlike the DFE, the magnitude of the changes in tolerated drug concentration resulting from genome-wide mutations is similar for most drugs but exceptionally small for the antibiotic nitrofurantoin, i.e., mutations generally have considerably smaller resistance effects for nitrofurantoin than for other drugs. A population genetics model predicts that resistance evolution for drugs with this property is severely limited and confined to reproducible mutational paths. We tested this prediction in laboratory evolution experiments using the "morbidostat", a device for evolving bacteria in well-controlled drug environments. Nitrofurantoin resistance indeed evolved extremely slowly via reproducible mutations-an almost paradoxical behavior since this drug causes DNA damage and increases the mutation

  5. Simultaneous wide-range stopping power determination for several ions

    Energy Technology Data Exchange (ETDEWEB)

    Alanko, T. E-mail: tommi.alanko@phys.jyu.fi; Trzaska, W.H.; Lyapin, V.; Raeisaenen, J.; Tiourine, G.; Virtanen, A

    2002-05-01

    A new procedure to extract simultaneously continuous stopping power curves for several ions and several absorbers over a wide energy range and with statistical errors reduced to negligible level is presented. The method combines our novel time-of-flight based method with the capability of our K130 cyclotron and ECR ion-source to produce the so-called ion cocktails. The potential of the method is demonstrated with a 6.0 MeV/u cocktail consisting of {sup 16}O{sup 4+}, {sup 28}Si{sup 7+} and {sup 40}Ar{sup 10+} ions. The stopping power in polycarbonate in the energy range of 0.35-5 MeV/u has been determined with absolute uncertainty of less than 2.3% and with relative below 0.2%. The results are compared with literature data and with SRIM2000 parameterisation including cores and bonds corrections.

  6. Genome-Wide Requirements for Resistance to Functionally Distinct DNA-Damaging Agents.

    Directory of Open Access Journals (Sweden)

    2005-08-01

    Full Text Available The mechanistic and therapeutic differences in the cellular response to DNA-damaging compounds are not completely understood, despite intense study. To expand our knowledge of DNA damage, we assayed the effects of 12 closely related DNA-damaging agents on the complete pool of ~4,700 barcoded homozygous deletion strains of Saccharomyces cerevisiae. In our protocol, deletion strains are pooled together and grown competitively in the presence of compound. Relative strain sensitivity is determined by hybridization of PCR-amplified barcodes to an oligonucleotide array carrying the barcode complements. These screens identified genes in well-characterized DNA-damage-response pathways as well as genes whose role in the DNA-damage response had not been previously established. High-throughput individual growth analysis was used to independently confirm microarray results. Each compound produced a unique genome-wide profile. Analysis of these data allowed us to determine the relative importance of DNA-repair modules for resistance to each of the 12 profiled compounds. Clustering the data for 12 distinct compounds uncovered both known and novel functional interactions that comprise the DNA-damage response and allowed us to define the genetic determinants required for repair of interstrand cross-links. Further genetic analysis allowed determination of epistasis for one of these functional groups.

  7. Determining the Resistivity of Resistive Sheets Using Transmission Measurements

    National Research Council Canada - National Science Library

    Hyde, IV, Milo W

    2006-01-01

    In September 2005, radar cross section (RCS) measurements were made of resistive sheets, or R-cards, wrapped around a polystyrene foam cylinder to compare with a newly developed theoretical RCS prediction technique...

  8. genome-wide association and metabolic pathway analysis of corn earworm resistance in maize

    Science.gov (United States)

    Marilyn L. Warburton; Erika D. Womack; Juliet D. Tang; Adam Thrash; J. Spencer Smith; Wenwei Xu; Seth C. Murray; W. Paul Williams

    2018-01-01

    Maize (Zea mays mays L.) is a staple crop of economic, industrial, and food security importance. Damage to the growing ears by corn earworm [Helicoverpa zea (Boddie)] is a major economic burden and increases secondary fungal infections and mycotoxin levels. To identify biochemical pathways associated with native resistance mechanisms, a genome-wide...

  9. Wide-range neutron dose determination with CR-39

    International Nuclear Information System (INIS)

    Arneja, A.R.; Waker, A.J.

    1995-01-01

    Optical density measurements of CR-30 irradiated with 252 Cf neutrons and chemically etched with 6.5 N KOH solution have been used to determine neutron absorbed doses between 0.1 and 10 Gy. Optimum etching conditions will depend upon the absorbed dose. Since it is not always possible to know the range of absorbed dose on a CR-39 dosemeter collected from personnel and area monitor stations in a criticality accident situation, a three-step two-hour chemical etch at 60 o C has been found to be appropriate. If after a total of six hours of chemical etching the optical density is found to be below 0.04 for 500 nm light (transmission > 90%) then further treatment in the form of electrochemical etching can be carried out to determine the lower absorbed dose. In this manner, absorbed doses below 0.1 Gy can be determined by counting tracks over a unit area. (author)

  10. Genome-Wide Association Study of Septoria tritici Blotch Resistance in Ethiopian Durum Wheat Landraces

    Directory of Open Access Journals (Sweden)

    Yosef G. Kidane

    2017-09-01

    Full Text Available Septoria tritici blotch (STB is a devastating fungal disease affecting durum and bread wheat cultivation worldwide. The identification, development, and employment of resistant wheat genetic material is the key to overcoming costs and limitations of fungicide treatments. The search for resistance sources in untapped genetic material may speed up the deployment of STB genetic resistance in the field. Ethiopian durum wheat landraces represent a valuable source of such diversity. In this study, 318 Ethiopian durum wheat genotypes, for the most part traditional landraces, were phenotyped for resistance to different aspects of STB infection. Phenology, yield and yield component traits were concurrently measured the collection. Here we describe the distribution of STB resistance traits in modern varieties and in landraces, and the relation existing between STB resistance and other agronomic traits. STB resistance sources were found in landraces as well as in modern varieties tested, suggesting the presence of alleles of breeding relevance. The genetic material was genotyped with more than 16 thousand genome-wide polymorphic markers to describe the linkage disequilibrium and genetic structure existing within the panel of genotypes, and a genome-wide association (GWA study was run to allow the identification of genomic loci involved in STB resistance. High diversity and low genetic structure in the panel allowed high efficiency GWA. The GWA scan detected five major putative QTL for STB resistance, only partially overlapping those already reported in the wheat literature. We report four putative loci for Septoria resistance with no match in previous literature: two highly significant ones on Chr 3A and 5A, and two suggestive ones on Chr 4B and 5B. Markers underlying these QTL explained as much as 10% of the phenotypic variance for disease resistance. We found three cases in which putative QTL for agronomic traits overlapped marker trait association

  11. Genome-wide re-sequencing of multidrug-resistant Mycobacterium leprae Airaku-3.

    Science.gov (United States)

    Singh, P; Benjak, A; Carat, S; Kai, M; Busso, P; Avanzi, C; Paniz-Mondolfi, A; Peter, C; Harshman, K; Rougemont, J; Matsuoka, M; Cole, S T

    2014-10-01

    Genotyping and molecular characterization of drug resistance mechanisms in Mycobacterium leprae enables disease transmission and drug resistance trends to be monitored. In the present study, we performed genome-wide analysis of Airaku-3, a multidrug-resistant strain with an unknown mechanism of resistance to rifampicin. We identified 12 unique non-synonymous single-nucleotide polymorphisms (SNPs) including two in the transporter-encoding ctpC and ctpI genes. In addition, two SNPs were found that improve the resolution of SNP-based genotyping, particularly for Venezuelan and South East Asian strains of M. leprae. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

  12. Genome-Wide Association Mapping of Stem Rust Resistance in Hordeum vulgare subsp. spontaneum.

    Science.gov (United States)

    Sallam, Ahmad H; Tyagi, Priyanka; Brown-Guedira, Gina; Muehlbauer, Gary J; Hulse, Alex; Steffenson, Brian J

    2017-10-05

    Stem rust was one of the most devastating diseases of barley in North America. Through the deployment of cultivars with the resistance gene Rpg1 , losses to stem rust have been minimal over the past 70 yr. However, there exist both domestic (QCCJB) and foreign (TTKSK aka isolate Ug99) pathotypes with virulence for this important gene. To identify new sources of stem rust resistance for barley, we evaluated the Wild Barley Diversity Collection (WBDC) (314 ecogeographically diverse accessions of Hordeum vulgare subsp. spontaneum ) for seedling resistance to four pathotypes (TTKSK, QCCJB, MCCFC, and HKHJC) of the wheat stem rust pathogen ( Puccinia graminis f. sp. tritici , Pgt ) and one isolate (92-MN-90) of the rye stem rust pathogen ( P. graminis f. sp. secalis , Pgs ). Based on a coefficient of infection, the frequency of resistance in the WBDC was low ranging from 0.6% with HKHJC to 19.4% with 92-MN-90. None of the accessions was resistant to all five cultures of P. graminis A genome-wide association study (GWAS) was conducted to map stem rust resistance loci using 50,842 single-nucleotide polymorphic markers generated by genotype-by-sequencing and ordered using the new barley reference genome assembly. After proper accounting for genetic relatedness and structure among accessions, 45 quantitative trait loci were identified for resistance to P. graminis across all seven barley chromosomes. Three novel loci associated with resistance to TTKSK, QCCJB, MCCFC, and 92-MN-90 were identified on chromosomes 5H and 7H, and two novel loci associated with resistance to HKHJC were identified on chromosomes 1H and 3H. These novel alleles will enhance the diversity of resistance available for cultivated barley. Copyright © 2017 Sallam et al.

  13. Determinants of Growth Hormone Resistance in Malnutrition

    Science.gov (United States)

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

    States of under-nutrition are characterized by growth hormone resistance. Decreased total energy intake, as well as isolated protein-calorie malnutrition and isolated nutrient deficiencies result in elevated growth hormone levels and low levels of IGF-I. We review various states of malnutrition and a disease state characterized by chronic under-nutrition -- anorexia nervosa -- and discuss possible mechanisms contributing to the state of growth hormone resistance, including FGF-21 and SIRT1. We conclude by examining the hypothesis that growth hormone resistance is an adaptive response to states of under-nutrition, in order to maintain euglycemia and preserve energy. PMID:24363451

  14. Genome-wide Association Study Identifies New Loci for Resistance to Leptosphaeria maculans in Canola

    Directory of Open Access Journals (Sweden)

    Harsh Raman

    2016-10-01

    Full Text Available Blackleg, caused by Leptosphaeria maculans, is a significant disease which affects the sustainable production of canola. This study reports a genome-wide association study based on 18,804 polymorphic SNPs to identify loci associated with qualitative and quantitative resistance to L. maculans. Genomic regions delimited with 503 significant SNP markers, that are associated with resistance evaluated using 12 single spore isolates and pathotypes from four canola stubble were identified. Several significant associations were detected at known disease resistance loci including in the vicinity of recently cloned Rlm2/LepR3 genes, and at new loci on chromosomes A01/C01, A02/C02, A03/C03, A05/C05, A06, A08, and A09. In addition, we validated statistically significant associations on A01, A07 and A10 in four genetic mapping populations, demonstrating that GWAS marker loci are indeed associated with resistance to L. maculans. One of the novel loci identified for the first time, Rlm12, conveys adult plant resistance and mapped within 13.2 kb from Arabidopsis R gene of TIR-NBS class. We showed that resistance loci are located in the vicinity of R genes of A. thaliana and B. napus on the sequenced genome of B. napus cv. Darmor-bzh. Significantly associated SNP markers provide a valuable tool to enrich germplasm for favorable alleles in order to improve the level of resistance to L. maculans in canola.

  15. Environmental Sciences Electrical resistivity soundings to determine ...

    African Journals Online (AJOL)

    Wood, leaves, newspaper, cloth, polythene bags, plastics, glass and metal refuse interspersed with soil exhibited resistivity of 11.6 ohm-m and layer thickness of 0.7 m as obtained from the inversion of the sounding. The unsaturated layer has a resistivity of 6.8 ohm-m and thickness of 0.6 m while leachate-saturated is ...

  16. Determination of the Drag Resistance Coefficients of Different Vehicles

    Science.gov (United States)

    Fahsl, Christoph; Vogt, Patrik

    2018-01-01

    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient "c" of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but…

  17. Genome-wide association analysis of oxidative stress resistance in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Allison L Weber

    Full Text Available Aerobic organisms are susceptible to damage by reactive oxygen species. Oxidative stress resistance is a quantitative trait with population variation attributable to the interplay between genetic and environmental factors. Drosophila melanogaster provides an ideal system to study the genetics of variation for resistance to oxidative stress.We used 167 wild-derived inbred lines of the Drosophila Genetic Reference Panel for a genome-wide association study of acute oxidative stress resistance to two oxidizing agents, paraquat and menadione sodium bisulfite. We found significant genetic variation for both stressors. Single nucleotide polymorphisms (SNPs associated with variation in oxidative stress resistance were often sex-specific and agent-dependent, with a small subset common for both sexes or treatments. Associated SNPs had moderately large effects, with an inverse relationship between effect size and allele frequency. Linear models with up to 12 SNPs explained 67-79% and 56-66% of the phenotypic variance for resistance to paraquat and menadione sodium bisulfite, respectively. Many genes implicated were novel with no known role in oxidative stress resistance. Bioinformatics analyses revealed a cellular network comprising DNA metabolism and neuronal development, consistent with targets of oxidative stress-inducing agents. We confirmed associations of seven candidate genes associated with natural variation in oxidative stress resistance through mutational analysis.We identified novel candidate genes associated with variation in resistance to oxidative stress that have context-dependent effects. These results form the basis for future translational studies to identify oxidative stress susceptibility/resistance genes that are evolutionary conserved and might play a role in human disease.

  18. Determination of electrical resistivity of dry coke beds

    Energy Technology Data Exchange (ETDEWEB)

    Eidem, P.A.; Tangstad, M.; Bakken, J.A. [NTNU, Trondheim (Norway)

    2008-02-15

    The electrical resistivity of the coke bed is of great importance when producing FeMn, SiMn, and FeCr in a submerged arc furnace. In these processes, a coke bed is situated below and around the electrode tip and consists of metallurgical coke, slag, gas, and metal droplets. Since the basic mechanisms determining the electrical resistivity of a coke bed is not yet fully understood, this investigation is focused on the resistivity of dry coke beds consisting of different carbonaceous materials, i.e., coke beds containing no slag or metal. A method that reliably compares the electrical bulk resistivity of different metallurgical cokes at 1500{sup o} C to 1600{sup o}C is developed. The apparatus is dimensioned for industrial sized materials, and the electrical resistivity of anthracite, charcoal, petroleum coke, and metallurgical coke has been measured. The resistivity at high temperatures of the Magnitogorsk coke, which has the highest resistivity of the metallurgical cokes investigated, is twice the resistivity of the Corus coke, which has the lowest electrical resistivity. Zdzieszowice and SSAB coke sort in between with decreasing resistivities in the respective order. The electrical resistivity of anthracite, charcoal, and petroleum coke is generally higher than the resistivity of the metallurgical cokes, ranging from about two to about eight times the resistivity of the Corus coke at 1450{sup o}C. The general trend is that the bulk resistivity of carbon materials decreases with increasing temperature and increasing particle size.

  19. Genome-Wide Association Mapping of Crown Rust Resistance in Oat Elite Germplasm.

    Science.gov (United States)

    Klos, Kathy Esvelt; Yimer, Belayneh A; Babiker, Ebrahiem M; Beattie, Aaron D; Bonman, J Michael; Carson, Martin L; Chong, James; Harrison, Stephen A; Ibrahim, Amir M H; Kolb, Frederic L; McCartney, Curt A; McMullen, Michael; Fetch, Jennifer Mitchell; Mohammadi, Mohsen; Murphy, J Paul; Tinker, Nicholas A

    2017-07-01

    Oat crown rust, caused by f. sp. , is a major constraint to oat ( L.) production in many parts of the world. In this first comprehensive multienvironment genome-wide association map of oat crown rust, we used 2972 single-nucleotide polymorphisms (SNPs) genotyped on 631 oat lines for association mapping of quantitative trait loci (QTL). Seedling reaction to crown rust in these lines was assessed as infection type (IT) with each of 10 crown rust isolates. Adult plant reaction was assessed in the field in a total of 10 location-years as percentage severity (SV) and as infection reaction (IR) in a 0-to-1 scale. Overall, 29 SNPs on 12 linkage groups were predictive of crown rust reaction in at least one experiment at a genome-wide level of statistical significance. The QTL identified here include those in regions previously shown to be linked with seedling resistance genes , , , , , and and also with adult-plant resistance and adaptation-related QTL. In addition, QTL on linkage groups Mrg03, Mrg08, and Mrg23 were identified in regions not previously associated with crown rust resistance. Evaluation of marker genotypes in a set of crown rust differential lines supported as the identity of . The SNPs with rare alleles associated with lower disease scores may be suitable for use in marker-assisted selection of oat lines for crown rust resistance. Copyright © 2017 Crop Science Society of America.

  20. Bacterial Multidrug Efflux Pumps: Much More Than Antibiotic Resistance Determinants.

    Science.gov (United States)

    Blanco, Paula; Hernando-Amado, Sara; Reales-Calderon, Jose Antonio; Corona, Fernando; Lira, Felipe; Alcalde-Rico, Manuel; Bernardini, Alejandra; Sanchez, Maria Blanca; Martinez, Jose Luis

    2016-02-16

    Bacterial multidrug efflux pumps are antibiotic resistance determinants present in all microorganisms. With few exceptions, they are chromosomally encoded and present a conserved organization both at the genetic and at the protein levels. In addition, most, if not all, strains of a given bacterial species present the same chromosomally-encoded efflux pumps. Altogether this indicates that multidrug efflux pumps are ancient elements encoded in bacterial genomes long before the recent use of antibiotics for human and animal therapy. In this regard, it is worth mentioning that efflux pumps can extrude a wide range of substrates that include, besides antibiotics, heavy metals, organic pollutants, plant-produced compounds, quorum sensing signals or bacterial metabolites, among others. In the current review, we present information on the different functions that multidrug efflux pumps may have for the bacterial behaviour in different habitats as well as on their regulation by specific signals. Since, in addition to their function in non-clinical ecosystems, multidrug efflux pumps contribute to intrinsic, acquired, and phenotypic resistance of bacterial pathogens, the review also presents information on the search for inhibitors of multidrug efflux pumps, which are currently under development, in the aim of increasing the susceptibility of bacterial pathogens to antibiotics.

  1. Prospecting sugarcane resistance to Sugarcane yellow leaf virus by genome-wide association.

    Science.gov (United States)

    Debibakas, S; Rocher, S; Garsmeur, O; Toubi, L; Roques, D; D'Hont, A; Hoarau, J-Y; Daugrois, J H

    2014-08-01

    Using GWAS approaches, we detected independent resistant markers in sugarcane towards a vectored virus disease. Based on comparative genomics, several candidate genes potentially involved in virus/aphid/plant interactions were pinpointed. Yellow leaf of sugarcane is an emerging viral disease whose causal agent is a Polerovirus, the Sugarcane yellow leaf virus (SCYLV) transmitted by aphids. To identify quantitative trait loci controlling resistance to yellow leaf which are of direct relevance for breeding, we undertook a genome-wide association study (GWAS) on a sugarcane cultivar panel (n = 189) representative of current breeding germplasm. This panel was fingerprinted with 3,949 polymorphic markers (DArT and AFLP). The panel was phenotyped for SCYLV infection in leaves and stalks in two trials for two crop cycles, under natural disease pressure prevalent in Guadeloupe. Mixed linear models including co-factors representing population structure fixed effects and pairwise kinship random effects provided an efficient control of the risk of inflated type-I error at a genome-wide level. Six independent markers were significantly detected in association with SCYLV resistance phenotype. These markers explained individually between 9 and 14 % of the disease variation of the cultivar panel. Their frequency in the panel was relatively low (8-20 %). Among them, two markers were detected repeatedly across the GWAS exercises based on the different disease resistance parameters. These two markers could be blasted on Sorghum bicolor genome and candidate genes potentially involved in plant-aphid or plant-virus interactions were localized in the vicinity of sorghum homologs of sugarcane markers. Our results illustrate the potential of GWAS approaches to prospect among sugarcane germplasm for accessions likely bearing resistance alleles of significant effect useful in breeding programs.

  2. Genome-wide Association Analysis of Powdery Mildew Resistance in U.S. Winter Wheat

    Science.gov (United States)

    Wheat powdery mildew (PM), caused by Blumeria graminis f. sp. tritici, is a major fungal disease of wheat worldwide. It can cause considerable yield losses when epidemics occur. Use of genetic resistance is the most effective approach to control the disease. To determine the genomic regions responsi...

  3. Determination of anthelmintic resistance in goats and sheep using ...

    African Journals Online (AJOL)

    Nematode parasites are known to pose a challenge to small ruminant production in Tanzania due to their fast development of resistance to the commonly used anthelmintics. The objective of this study was to determine the resistance of anthelmintics in small ruminants. A total of 30 sheep and 30 goats aged between 6 and ...

  4. Antimicrobial resistance determinant microarray for analysis of multi-drug resistant isolates

    Science.gov (United States)

    Taitt, Chris Rowe; Leski, Tomasz; Stenger, David; Vora, Gary J.; House, Brent; Nicklasson, Matilda; Pimentel, Guillermo; Zurawski, Daniel V.; Kirkup, Benjamin C.; Craft, David; Waterman, Paige E.; Lesho, Emil P.; Bangurae, Umaru; Ansumana, Rashid

    2012-06-01

    The prevalence of multidrug-resistant infections in personnel wounded in Iraq and Afghanistan has made it challenging for physicians to choose effective therapeutics in a timely fashion. To address the challenge of identifying the potential for drug resistance, we have developed the Antimicrobial Resistance Determinant Microarray (ARDM) to provide DNAbased analysis for over 250 resistance genes covering 12 classes of antibiotics. Over 70 drug-resistant bacteria from different geographic regions have been analyzed on ARDM, with significant differences in patterns of resistance identified: genes for resistance to sulfonamides, trimethoprim, chloramphenicol, rifampin, and macrolide-lincosamidesulfonamide drugs were more frequently identified in isolates from sources in Iraq/Afghanistan. Of particular concern was the presence of genes responsible for resistance to many of the last-resort antibiotics used to treat war traumaassociated infections.

  5. Antimicrobial resistance and resistance gene determinants in clinical Escherichia coli from different animal species in Switzerland.

    Science.gov (United States)

    Lanz, Roland; Kuhnert, Peter; Boerlin, Patrick

    2003-01-02

    Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.

  6. Determination of rolling resistance coefficient based on normal tyre stiffness

    Science.gov (United States)

    Rykov, S. P.; Tarasuyk, V. N.; Koval, V. S.; Ovchinnikova, N. I.; Fedotov, A. I.; Fedotov, K. V.

    2018-03-01

    The purpose of the article is to develop analytical dependence of wheel rolling resistance coefficient based on the mathematical description of normal tyre stiffness. The article uses the methods of non-holonomic mechanics and plane section methods. The article shows that the abscissa of gravity center of tyre stiffness expansion by the length of the contact area is the shift of normal road response. It can be used for determining rolling resistance coefficient. When determining rolling resistance coefficient using ellipsis and power function equations, one can reduce labor costs for testing and increase assessment accuracy.

  7. Genome-wide mapping of virulence in brown planthopper identifies loci that break down host plant resistance.

    Science.gov (United States)

    Jing, Shengli; Zhang, Lei; Ma, Yinhua; Liu, Bingfang; Zhao, Yan; Yu, Hangjin; Zhou, Xi; Qin, Rui; Zhu, Lili; He, Guangcun

    2014-01-01

    Insects and plants have coexisted for over 350 million years and their interactions have affected ecosystems and agricultural practices worldwide. Variation in herbivorous insects' virulence to circumvent host resistance has been extensively documented. However, despite decades of investigation, the genetic foundations of virulence are currently unknown. The brown planthopper (Nilaparvata lugens) is the most destructive rice (Oryza sativa) pest in the world. The identification of the resistance gene Bph1 and its introduction in commercial rice varieties prompted the emergence of a new virulent brown planthopper biotype that was able to break the resistance conferred by Bph1. In this study, we aimed to construct a high density linkage map for the brown planthopper and identify the loci responsible for its virulence in order to determine their genetic architecture. Based on genotyping data for hundreds of molecular markers in three mapping populations, we constructed the most comprehensive linkage map available for this species, covering 96.6% of its genome. Fifteen chromosomes were anchored with 124 gene-specific markers. Using genome-wide scanning and interval mapping, the Qhp7 locus that governs preference for Bph1 plants was mapped to a 0.1 cM region of chromosome 7. In addition, two major QTLs that govern the rate of insect growth on resistant rice plants were identified on chromosomes 5 (Qgr5) and 14 (Qgr14). This is the first study to successfully locate virulence in the genome of this important agricultural insect by marker-based genetic mapping. Our results show that the virulence which overcomes the resistance conferred by Bph1 is controlled by a few major genes and that the components of virulence originate from independent genetic characters. The isolation of these loci will enable the elucidation of the molecular mechanisms underpinning the rice-brown planthopper interaction and facilitate the development of durable approaches for controlling this most

  8. Genome-wide mapping of virulence in brown planthopper identifies loci that break down host plant resistance.

    Directory of Open Access Journals (Sweden)

    Shengli Jing

    Full Text Available Insects and plants have coexisted for over 350 million years and their interactions have affected ecosystems and agricultural practices worldwide. Variation in herbivorous insects' virulence to circumvent host resistance has been extensively documented. However, despite decades of investigation, the genetic foundations of virulence are currently unknown. The brown planthopper (Nilaparvata lugens is the most destructive rice (Oryza sativa pest in the world. The identification of the resistance gene Bph1 and its introduction in commercial rice varieties prompted the emergence of a new virulent brown planthopper biotype that was able to break the resistance conferred by Bph1. In this study, we aimed to construct a high density linkage map for the brown planthopper and identify the loci responsible for its virulence in order to determine their genetic architecture. Based on genotyping data for hundreds of molecular markers in three mapping populations, we constructed the most comprehensive linkage map available for this species, covering 96.6% of its genome. Fifteen chromosomes were anchored with 124 gene-specific markers. Using genome-wide scanning and interval mapping, the Qhp7 locus that governs preference for Bph1 plants was mapped to a 0.1 cM region of chromosome 7. In addition, two major QTLs that govern the rate of insect growth on resistant rice plants were identified on chromosomes 5 (Qgr5 and 14 (Qgr14. This is the first study to successfully locate virulence in the genome of this important agricultural insect by marker-based genetic mapping. Our results show that the virulence which overcomes the resistance conferred by Bph1 is controlled by a few major genes and that the components of virulence originate from independent genetic characters. The isolation of these loci will enable the elucidation of the molecular mechanisms underpinning the rice-brown planthopper interaction and facilitate the development of durable approaches for

  9. Antimicrobial susceptibility and tetracycline resistance determinant genotyping of Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Vazquez, Maria E.; Bager, Ragnhild J.

    2011-01-01

    no determinant was identified.This is the first study to determine the antimicrobial susceptibility of Gallibacterium anatis by MIC revealing that multidrug resistance is very common among G. anatis field isolates. tet(B) was by far the most common determinant identified but future work should aim at identifying......The present investigation was undertaken to assess the antimicrobial susceptibility of a collection of 58 Gallibacterium isolates. All strains were tested by the broth dilution method using the veterinary fastidious medium. A total of 46 field strains were tested, whereof 23 were clinical isolates....... Multidrug resistance (resistance towards≥three drugs) was observed for 65% of the field strains and only two strains were susceptible to all compounds. Most prominently, resistance to tetracycline and sulfamethoxazole was observed in 92% and 97% of the field strains, respectively. For comparison...

  10. Genome-Wide Transcriptional Profiling of Clostridium perfringens SM101 during Sporulation Extends the Core of Putative Sporulation Genes and Genes Determining Spore Properties and Germination Characteristics

    NARCIS (Netherlands)

    Xiao, Y.; Hijum, S.A.F.T. van; Abee, T.; Wells-Bennik, M.H.

    2015-01-01

    The formation of bacterial spores is a highly regulated process and the ultimate properties of the spores are determined during sporulation and subsequent maturation. A wide variety of genes that are expressed during sporulation determine spore properties such as resistance to heat and other adverse

  11. Genome-wide transcriptional profiling of Clostridium perfringens SM101 during sporulation extends the core of putative sporulation genes and genes determining spore properties and germination characteristics

    NARCIS (Netherlands)

    Xiao, Y.; Hijum, van S.A.F.T.; Abee, T.; Wells-Bennik, M.H.J.

    2015-01-01

    The formation of bacterial spores is a highly regulated process and the ultimate properties of the spores are determined during sporulation and subsequent maturation. A wide variety of genes that are expressed during sporulation determine spore properties such as resistance to heat and other adverse

  12. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  13. A genome-wide approach accounting for body mass index identifies genetic variants influencing fasting glycemic traits and insulin resistance

    NARCIS (Netherlands)

    Manning, Alisa K.; Hivert, Marie-France; Scott, Robert A.; Grimsby, Jonna L.; Bouatia-Naji, Nabila; Chen, Han; Rybin, Denis; Liu, Ching-Ti; Bielak, Lawrence F.; Prokopenko, Inga; Amin, Najaf; Barnes, Daniel; Cadby, Gemma; Hottenga, Jouke-Jan; Ingelsson, Erik; Jackson, Anne U.; Johnson, Toby; Kanoni, Stavroula; Ladenvall, Claes; Lagou, Vasiliki; Lahti, Jari; Lecoeur, Cecile; Liu, Yongmei; Martinez-Larrad, Maria Teresa; Montasser, May E.; Navarro, Pau; Perry, John R. B.; Rasmussen-Torvik, Laura J.; Salo, Perttu; Sattar, Naveed; Shungin, Dmitry; Strawbridge, Rona J.; Tanaka, Toshiko; van Duijn, Cornelia M.; An, Ping; de Andrade, Mariza; Andrews, Jeanette S.; Aspelund, Thor; Atalay, Mustafa; Aulchenko, Yurii; Balkau, Beverley; Bandinelli, Stefania; Beckmann, Jacques S.; Beilby, John P.; Bellis, Claire; Bergman, Richard N.; Blangero, John; Boban, Mladen; Kumari, Meena; Penninx, Brenda

    Recent genome-wide association studies have described many loci implicated in type 2 diabetes (T2D) pathophysiology and beta-cell dysfunction but have contributed little to the understanding of the genetic basis of insulin resistance. We hypothesized that genes implicated in insulin resistance

  14. Prevalence of plasmid-mediated quinolone resistance determinants among oxyiminocephalosporin-resistant Enterobacteriaceae in Argentina

    Directory of Open Access Journals (Sweden)

    Giovanna Rincon Cruz

    2013-11-01

    Full Text Available High quinolone resistance rates were observed among oxyiminocephalosporin-resistant enterobacteria. In the present study, we searched for the prevalence of plasmid-mediated quinolone resistance (PMQR genes within the 55 oxyiminocephalosporin-resistant enterobacteria collected in a previous survey. The main PMQR determinants were aac(6'-Ib-cr and qnrB, which had prevalence rates of 42.4% and 33.3%, respectively. The aac(6'-Ib-cr gene was more frequently found in CTX-M-15-producing isolates, while qnrB was homogeneously distributed among all CTX-M producers.

  15. Antimicrobial resistance determinants among anaerobic bacteria isolated from footrot.

    Science.gov (United States)

    Lorenzo, María; García, Nuria; Ayala, Juan Alfonso; Vadillo, Santiago; Píriz, Segundo; Quesada, Alberto

    2012-05-25

    Antibiotic resistance has been evaluated among 36 Gram negative and anaerobic bacilli (10 Bacteroides, 11 Prevotella, 7 Porphyromonas and 8 Fusobacterium strains) isolated from clinical cases of caprine and ovine footrot (necrotic pododermatitis). The initial analysis on this bacterial consortium evaluates the relationships existing among antimicrobial resistance determinants, phenotype expression and mobilization potential. The Bacteroides strains were generally resistant to penicillins, first-generation cephalosporins, tetracycline and erythromycin, and expressed low level of β-lactamase activity. The main determinants found among the Bacteroides strains were cepA and tetQ genes, conferring resistance to β-lactams and tetracycline, respectively. A general susceptibility to β-lactams was shown for most Prevotella, Porphyromonas and Fusobacterium strains, where none of the β-lactamase genes described in Bacteroides was detected. Resistance to tetracycline and/or erythromycin was found among the three bacterial groups. Although tetQ genes were detected for several Prevotella and Porphyromonas strains, a unique ermF positive was revealed among Prevotella strains. The expression of resistance markers was not related with the polymorphism of their coding sequences. However, the finding of sequence signatures for conjugative transposons in the vicinities of tetQ and ermF suggests a mobilization potential that might have contributed to the spread of antimicrobial resistance genes. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Determination of the drag resistance coefficients of different vehicles

    Science.gov (United States)

    Fahsl, Christoph; Vogt, Patrik

    2018-05-01

    While it has been demonstrated how air resistance could be analyzed by using mobile devices, this paper demonstrates a method of how to determine the drag resistance coefficient c of a commercial automobile by using the acceleration sensor of a smartphone or tablet. In an academic context, the drag resistance is often mentioned, but little attention is paid to quantitative measurements. This experiment was driven by the fact that this physical value is most certainly neglected because of its difficult measurability. In addition to that, this experiment gives insights on how the aerodynamic factor of an automobile affects the energy dissipation and thus how much power is required by automobile transportation.

  17. Genetic Determinants of High-Level Oxacillin Resistance in Methicillin-Resistant Staphylococcus aureus.

    Science.gov (United States)

    Pardos de la Gandara, Maria; Borges, Vitor; Chung, Marilyn; Milheiriço, Catarina; Gomes, João Paulo; de Lencastre, Herminia; Tomasz, Alexander

    2018-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) strains carry either a mecA - or a mecC -mediated mechanism of resistance to beta-lactam antibiotics, and the phenotypic expression of resistance shows extensive strain-to-strain variation. In recent communications, we identified the genetic determinants associated with the stringent stress response that play a major role in the antibiotic resistant phenotype of the historically earliest "archaic" clone of MRSA and in the mecC -carrying MRSA strain LGA251. Here, we sought to test whether or not the same genetic determinants also contribute to the resistant phenotype of highly and homogeneously resistant (H*R) derivatives of a major contemporary MRSA clone, USA300. We found that the resistance phenotype was linked to six genes ( fruB , gmk , hpt , purB , prsA , and relA ), which were most frequently targeted among the analyzed 20 H*R strains (one mutation per clone in 19 of the 20 H*R strains). Besides the strong parallels with our previous findings (five of the six genes matched), all but one of the repeatedly targeted genes were found to be linked to guanine metabolism, pointing to the key role that this pathway plays in defining the level of antibiotic resistance independent of the clonal type of MRSA. Copyright © 2018 American Society for Microbiology.

  18. An ultrathin wide-band planar metamaterial absorber based on a fractal frequency selective surface and resistive film

    International Nuclear Information System (INIS)

    Fan Yue-Nong; Cheng Yong-Zhi; Nie Yan; Wang Xian; Gong Rong-Zhou

    2013-01-01

    We propose an ultrathin wide-band metamaterial absorber (MA) based on a Minkowski (MIK) fractal frequency selective surface and resistive film. This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film. The finite element method is used to simulate and analyze the absorption of the MA. Compared with the MA-backed copper film, the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz–20 GHz. The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA. Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled. Finally, further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA. This absorber may be used in many military fields

  19. Determination of slope failure using 2-D resistivity method

    Science.gov (United States)

    Muztaza, Nordiana Mohd; Saad, Rosli; Ismail, Nur Azwin; Bery, Andy Anderson

    2017-07-01

    Landslides and slope failure may give negative economic effects including the cost to repair structures, loss of property value and medical costs in the event of injury. To avoid landslide, slope failure and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. Slope failure classification and various factors contributing to the instability using 2-D resistivity survey conducted in Selangor, Malaysia are described. The study on landslide and slope failure was conducted at Site A and Site B, Selangor using 2-D resistivity method. The implications of the anticipated ground conditions as well as the field observation of the actual conditions are discussed. Nine 2-D resistivity survey lines were conducted in Site A and six 2-D resistivity survey lines with 5 m minimum electrode spacing using Pole-dipole array were performed in Site B. The data were processed using Res2Dinv and Surfer10 software to evaluate the subsurface characteristics. 2-D resistivity results from both locations show that the study areas consist of two main zones. The first zone is alluvium or highly weathered with the resistivity of 100-1000 Ωm at 20-70 m depth. This zone consists of saturated area (1-100 Ωm) and boulders with resistivity value of 1200-3000 Ωm. The second zone with resistivity values of > 3000 Ωm was interpreted as granitic bedrock. The study area was characterized by saturated zones, highly weathered zone, highly contain of sand and boulders that will trigger slope failure in the survey area. Based on the results obtained from the study findings, it can be concluded that 2-D resistivity method is useful method in determination of slope failure.

  20. "Tissue oxygen tension, a determinant of resistance to infection and ...

    African Journals Online (AJOL)

    "Tissue oxygen tension, a determinant of resistance to infection and healing" - An Inaugural Lecture. K Jönsson. Abstract. An Inaugural Lecture Given in the University of Zimbabwe on 21 June 2001. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Wide Distribution of Carbapenem Resistant Acinetobacter baumannii in Burns Patients in Iran

    Directory of Open Access Journals (Sweden)

    zahra eFarshadzadeh

    2015-10-01

    Full Text Available Antimicrobial resistance in carbapenem non-susceptible Acinetobacter baumannii (CNSAb is a major public health concern globally. This study determined the antibiotic resistance and molecular epidemiology of CNSAb isolates from a referral burn center in Tehran, Iran.Sixty-nine CNSAb isolates were tested for susceptibility to antimicrobial agents using the E-test methodology. Multiple locus variable number tandem repeat analysis (MLVA, Multilocus sequence typing and multiplex PCR were performed. PCR assays tested for ambler classes A, B, and D β-lactamases. Detection of ISAba1, characterization of integrons, and biofilm formation were investigated.Fifty-three (77% isolates revealed XDR phenotypes. High prevalence of blaOXA-23-like (88% and blaPER-1 (54% were detected. ISAba1 was detected upstream of blaADC, blaOXA-23-like and blaOXA51-like genes in, 97, 42 and 26% of isolates, respectively. Thirty-one (45% isolates were assigned to International Clone (IC variants. MLVA identified 56 distinct types with 6 clusters and 53 singleton genotypes. Forty previously known MLST sequence types forming 5 clonal complexes were identified. The Class 1 integron (class 1 integrons gene was identified in 84% of the isolates. The most prevalent (33% cassette combination was aacA4-catB8-aadA1. The IC variants were predominant in the A. baumannii lineage with the ability to form strong biofilms.The XDR-CNSAb from burned patients

  2. Determination of Ductile Tearing Resistance Curve in Weld Joints

    International Nuclear Information System (INIS)

    Marie, S.; Gilles, P.; Ould, P.

    2010-01-01

    Steels present in the ductile domain a tearing resistance which increase with the crack propagation up to the failure. This ductile tearing resistance is in general characterised with curves giving the variation of a global parameter (opening displacement at the crack tip delta, integral J) versus the crack extension Delta a. These global approaches depend more or less on the specimen geometry and on the type of the imposed loading. Local approaches based on the description of the ductile tearing mechanisms provide reliable solution to the transferability problem (from the lab specimen to the component) but are complex and costly to use and are not codified. These problems get worse in the case of a weld joint where no standard is available for the measurement of their ductile tearing resistance. But the welded joints are often the weak point of the structure because of greater risk of defects, the heterogeneity of the microstructure of the weld, deformation along the interface between two materials with different yield stress (mismatch).... After briefly recalling the problems of transferability of the ductile tearing resistance curves obtained on lab specimen to the case of components, this article identifies the factors complicating the determination of the toughness in the welded joints and gives recommendations for the experimental determination of ductile tearing resistance curves of welded joints

  3. Genome-wide association mapping of partial resistance to Phytophthora sojae in soybean plant introductions from the Republic of Korea.

    Science.gov (United States)

    Schneider, Rhiannon; Rolling, William; Song, Qijian; Cregan, Perry; Dorrance, Anne E; McHale, Leah K

    2016-08-11

    Phytophthora root and stem rot is one of the most yield-limiting diseases of soybean [Glycine max (L.) Merr], caused by the oomycete Phytophthora sojae. Partial resistance is controlled by several genes and, compared to single gene (Rps gene) resistance to P. sojae, places less selection pressure on P. sojae populations. Thus, partial resistance provides a more durable resistance against the pathogen. In previous work, plant introductions (PIs) originating from the Republic of Korea (S. Korea) have shown to be excellent sources for high levels of partial resistance against P. sojae. Resistance to two highly virulent P. sojae isolates was assessed in 1395 PIs from S. Korea via a greenhouse layer test. Lines exhibiting possible Rps gene immunity or rot due to other pathogens were removed and the remaining 800 lines were used to identify regions of quantitative resistance using genome-wide association mapping. Sixteen SNP markers on chromosomes 3, 13 and 19 were significantly associated with partial resistance to P. sojae and were grouped into seven quantitative trait loci (QTL) by linkage disequilibrium blocks. Two QTL on chromosome 3 and three QTL on chromosome 19 represent possible novel loci for partial resistance to P. sojae. While candidate genes at QTL varied in their predicted functions, the coincidence of QTLs 3-2 and 13-1 on chromosomes 3 and 13, respectively, with Rps genes and resistance gene analogs provided support for the hypothesized mechanism of partial resistance involving weak R-genes. QTL contributing to partial resistance towards P. sojae in soybean germplasm originating from S. Korea were identified. The QTL identified in this study coincide with previously reported QTL, Rps genes, as well as novel loci for partial resistance. Molecular markers associated with these QTL can be used in the marker-assisted introgression of these alleles into elite cultivars. Annotations of genes within QTL allow hypotheses on the possible mechanisms of partial

  4. Development of Elite BPH-Resistant Wide-Spectrum Restorer Lines for Three and Two Line Hybrid Rice.

    Science.gov (United States)

    Fan, Fengfeng; Li, Nengwu; Chen, Yunping; Liu, Xingdan; Sun, Heng; Wang, Jie; He, Guangcun; Zhu, Yingguo; Li, Shaoqing

    2017-01-01

    Hybrid rice has contributed significantly to the world food security. Breeding of elite high-yield, strong-resistant broad-spectrum restorer line is an important strategy for hybrid rice in commercial breeding programs. Here, we developed three elite brown planthopper (BPH)-resistant wide-spectrum restorer lines by pyramiding big-panicle gene Gn8.1 , BPH-resistant genes Bph6 and Bph9 , fertility restorer genes Rf3, Rf4, Rf5 , and Rf6 through molecular marker assisted selection. Resistance analysis revealed that the newly developed restorer lines showed stronger BPH-resistance than any of the single-gene donor parent Luoyang-6 and Luoyang-9. Moreover, the three new restorer lines had broad spectrum recovery capabilities for Honglian CMS, Wild abortive CMS and two-line GMS sterile lines, and higher grain yields than that of the recurrent parent 9,311 under nature field conditions. Importantly, the hybrid crosses also showed good performance for grain yield and BPH-resistance. Thus, the development of elite BPH-resistant wide-spectrum restorer lines has a promising future for breeding of broad spectrum BPH-resistant high-yield varieties.

  5. Genome Wide Analysis of Nucleotide-Binding Site Disease Resistance Genes in Brachypodium distachyon

    Directory of Open Access Journals (Sweden)

    Shenglong Tan

    2012-01-01

    Full Text Available Nucleotide-binding site (NBS disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Many R-genes have been identified in various plant species. However, little is known about the NBS-encoding genes in Brachypodium distachyon. In this study, using computational analysis of the B. distachyon genome, we identified 126 regular NBS-encoding genes and characterized them on the bases of structural diversity, conserved protein motifs, chromosomal locations, gene duplications, promoter region, and phylogenetic relationships. EST hits and full-length cDNA sequences (from Brachypodium database of 126 R-like candidates supported their existence. Based on the occurrence of conserved protein motifs such as coiled-coil (CC, NBS, leucine-rich repeat (LRR, these regular NBS-LRR genes were classified into four subgroups: CC-NBS-LRR, NBS-LRR, CC-NBS, and X-NBS. Further expression analysis of the regular NBS-encoding genes in Brachypodium database revealed that these genes are expressed in a wide range of libraries, including those constructed from various developmental stages, tissue types, and drought challenged or nonchallenged tissue.

  6. Pacific-wide contrast highlights resistance of reef calcifiers to ocean acidification.

    Science.gov (United States)

    Comeau, S; Carpenter, R C; Nojiri, Y; Putnam, H M; Sakai, K; Edmunds, P J

    2014-09-07

    Ocean acidification (OA) and its associated decline in calcium carbonate saturation states is one of the major threats that tropical coral reefs face this century. Previous studies of the effect of OA on coral reef calcifiers have described a wide variety of outcomes for studies using comparable partial pressure of CO2 (pCO2) ranges, suggesting that key questions remain unresolved. One unresolved hypothesis posits that heterogeneity in the response of reef calcifiers to high pCO2 is a result of regional-scale variation in the responses to OA. To test this hypothesis, we incubated two coral taxa (Pocillopora damicornis and massive Porites) and two calcified algae (Porolithon onkodes and Halimeda macroloba) under 400, 700 and 1000 μatm pCO2 levels in experiments in Moorea (French Polynesia), Hawaii (USA) and Okinawa (Japan), where environmental conditions differ. Both corals and H. macroloba were insensitive to OA at all three locations, while the effects of OA on P. onkodes were location-specific. In Moorea and Hawaii, calcification of P. onkodes was depressed by high pCO2, but for specimens in Okinawa, there was no effect of OA. Using a study of large geographical scale, we show that resistance to OA of some reef species is a constitutive character expressed across the Pacific. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  7. Some aspects of radiation resistance of wide-gap metal oxides

    International Nuclear Information System (INIS)

    Lushchik, Aleksandr; Feldbach, Eduard; Galajev, Semjon; Kaerner, Tiit; Liblik, Peeter; Lushchik, Cheslav; Maaroos, Aarne; Nagirnyi, Vitali; Vasil'chenko, Evgeni

    2007-01-01

    Wide-gap oxides drastically differ in radiation resistance against nonimpact mechanisms of defect creation depending on the ratio between the values of the energy gap E g and the formation energy of a pair of Frenkel defects (FD) E FD . Materials with E g >E FD are radiation-sensitive even at a low excitation density, while the efficiency of FD creation in the materials with E g FD is noticeable only under a high excitation density or in the presence of impurity centers serving as the promoters of radiation damage due to the nonimpact mechanisms. Novel experimental results on the FD creation in the bulk of MgO single crystals (E g FD ) irradiated by swift uranium ions at 300 K and 5 keV electrons at 6 K are presented. The prospects of luminescent protection against radiation damage as well as of the decrease of the luminescence efficiency due to the suppression of nonradiative recombination of electrons and holes (both relaxed and nonrelaxed) by doping the material with a sufficient amount of luminescent impurity ions are considered on the example of spectral transformers for plasma display panels

  8. MIRAGE WF infrared scene projector system, with 1536 x 768 wide format resistive array, performance data

    Science.gov (United States)

    Sparkman, Kevin; Laveigne, Joe; Oleson, Jim; Franks, Greg; McHugh, Steve; Lannon, John; Woode, Brian; Greer, Derek; Bui, Nicole

    2009-05-01

    MIRAGE WF is the latest high definition version of the MIRAGE infrared scene projector product line from Santa Barbara Infrared Inc. (SBIR). MIRAGE WF is being developed under the Wide Format Resistive Array (WFRA) program. The WFRA development is one of several efforts within the Infrared Sensor Simulator - Preplanned Product Improvement (IRSS P3I) umbrella funded by the Central Test and Evaluation Investment Program (CTEIP) and led by the US Navy at Patuxent River, MD. Three MIRAGE WF infrared scene projection systems are being delivered as part of the WFRA program. The main differences between the MIRAGE XL (1024x1024) and MIRAGE WF are a 1536x768 emitter array and 100Hz true raster capability. The key emitter requirements that have been measured and will be discussed include: Operability, Maximum Apparent Temperature, Rise Time and Array Uniformity. Key System specifications are: 1536x768 pixels, maximum apparent temperature of 600K, maximum frame rate of 100Hz, raster and snap shot updating, radiance rise and fall time less than 5 ms and windowed mode (1024x768) operation at up to 200 Hz.

  9. Genome-wide association study of pre-harvest sprouting resistance in Chinese wheat founder parents

    Directory of Open Access Journals (Sweden)

    Yu Lin

    2017-07-01

    Full Text Available Abstract Pre-harvest sprouting (PHS is a major abiotic factor affecting grain weight and quality, and is caused by an early break in seed dormancy. Association mapping (AM is used to detect correlations between phenotypes and genotypes based on linkage disequilibrium (LD in wheat breeding programs. We evaluated seed dormancy in 80 Chinese wheat founder parents in five environments and performed a genome-wide association study using 6,057 markers, including 93 simple sequence repeat (SSR, 1,472 diversity array technology (DArT, and 4,492 single nucleotide polymorphism (SNP markers. The general linear model (GLM and the mixed linear model (MLM were used in this study, and two significant markers (tPt-7980 and wPt-6457 were identified. Both markers were located on Chromosome 1B, with wPt-6457 having been identified in a previously reported chromosomal position. The significantly associated loci contain essential information for cloning genes related to resistance to PHS and can be used in wheat breeding programs.

  10. Method of separate determination of high-ohmic sample resistance and contact resistance

    Directory of Open Access Journals (Sweden)

    Vadim A. Golubiatnikov

    2015-09-01

    Full Text Available A method of separate determination of two-pole sample volume resistance and contact resistance is suggested. The method is applicable to high-ohmic semiconductor samples: semi-insulating gallium arsenide, detector cadmium-zinc telluride (CZT, etc. The method is based on near-contact region illumination by monochromatic radiation of variable intensity from light emitting diodes with quantum energies exceeding the band gap of the material. It is necessary to obtain sample photo-current dependence upon light emitting diode current and to find the linear portion of this dependence. Extrapolation of this linear portion to the Y-axis gives the cut-off current. As the bias voltage is known, it is easy to calculate sample volume resistance. Then, using dark current value, one can determine the total contact resistance. The method was tested for n-type semi-insulating GaAs. The contact resistance value was shown to be approximately equal to the sample volume resistance. Thus, the influence of contacts must be taken into account when electrophysical data are analyzed.

  11. Genome wide single cell analysis of chemotherapy resistant metastatic cells in a case of gastroesophageal adenocarcinoma

    International Nuclear Information System (INIS)

    Hjortland, Geir Olav; Fodstad, Oystein; Smeland, Sigbjorn; Hovig, Eivind; Meza-Zepeda, Leonardo A; Beiske, Klaus; Ree, Anne H; Tveito, Siri; Hoifodt, Hanne; Bohler, Per J; Hole, Knut H; Myklebost, Ola

    2011-01-01

    Metastatic progression due to development or enrichment of therapy-resistant tumor cells is eventually lethal. Molecular characterization of such chemotherapy resistant tumor cell clones may identify markers responsible for malignant progression and potential targets for new treatment. Here, in a case of stage IV adenocarcinoma of the gastroesophageal junction, we report the successful genome wide analysis using array comparative genomic hybridization (CGH) of DNA from only fourteen tumor cells using a bead-based single cell selection method from a bone metastasis progressing during chemotherapy. In a case of metastatic adenocarcinoma of the gastroesophageal junction, the progression of bone metastasis was observed during a chemotherapy regimen of epirubicin, oxaliplatin and capecitabine, whereas lung-, liver and lymph node metastases as well as the primary tumor were regressing. A bone marrow aspirate sampled at the site of progressing metastasis in the right iliac bone was performed, and single cell molecular analysis using array-CGH of Epithelial Specific Antigen (ESA)-positive metastatic cells, and revealed two distinct regions of amplification, 12p12.1 and 17q12-q21.2 amplicons, containing the KRAS (12p) and ERBB2 (HER2/NEU) (17q) oncogenes. Further intrapatient tumor heterogeneity of these highlighted gene copy number changes was analyzed by fluorescence in situ hybridization (FISH) in all available primary and metastatic tumor biopsies, and ErbB2 protein expression was investigated by immunohistochemistry. ERBB2 was heterogeneously amplified by FISH analysis in the primary tumor, as well as liver and bone metastasis, but homogenously amplified in biopsy specimens from a progressing bone metastasis after three initial cycles of chemotherapy, indicating a possible enrichment of erbB2 positive tumor cells in the progressing bone marrow metastasis during chemotherapy. A similar amplification profile was detected for wild-type KRAS, although more heterogeneously

  12. Antimicrobial Resistance of Hypervirulent Klebsiella pneumoniae: Epidemiology, Hypervirulence-Associated Determinants, and Resistance Mechanisms

    Directory of Open Access Journals (Sweden)

    Chang-Ro Lee

    2017-11-01

    Full Text Available Klebsiella pneumoniae is one of the most clinically relevant species in immunocompromised individuals responsible for community-acquired and nosocomial infections, including pneumonias, urinary tract infections, bacteremias, and liver abscesses. Since the mid-1980s, hypervirulent K. pneumoniae, generally associated with the hypermucoviscosity phenotype, has emerged as a clinically significant pathogen responsible for serious disseminated infections, such as pyogenic liver abscesses, osteomyelitis, and endophthalmitis, in a generally younger and healthier population. Hypervirulent K. pneumoniae infections were primarily found in East Asia and now are increasingly being reported worldwide. Although most hypervirulent K. pneumoniae isolates are antibiotic-susceptible, some isolates with combined virulence and resistance, such as the carbapenem-resistant hypervirulent K. pneumoniae isolates, are increasingly being detected. The combination of multidrug resistance and enhanced virulence has the potential to cause the next clinical crisis. To better understand the basic biology of hypervirulent K. pneumoniae, this review will provide a summarization and discussion focused on epidemiology, hypervirulence-associated factors, and antibiotic resistance mechanisms of such hypervirulent strains. Epidemiological analysis of recent clinical isolates in China warns the global dissemination of hypervirulent K. pneumoniae strains with extensive antibiotic resistance in the near future. Therefore, an immediate response to recognize the global dissemination of this hypervirulent strain with resistance determinants is an urgent priority.

  13. Determining the resistance of X-pinch plasma

    International Nuclear Information System (INIS)

    Zhao Shen; Zhu Xin-Lei; Zhang Ran; Luo Hai-Yun; Zou Xiao-Bing; Wang Xin-Xin; Xue Chuang; Ning Cheng; Ding Ning; Shu Xiao-Jian

    2013-01-01

    The current and the voltage of an X-pinch were measured. The inductance of the X-pinch was assumed to be a constant and estimated by the calculation of the magnetic field based on the well-known Biot—Savart's Law. The voltage of the inductance was calculated with L · di/dt and subtracted from the measured voltage of the X-pinch. Then, the resistance of the X-pinch was determined and the following results were obtained. At the start of the current flow the resistance of the exploding wires is several tens of Ohms, one order of magnitude, higher than the metallic resistance of the wires at room temperature, and then it falls quickly to about 1 Ω, which reflects the physical processes occurring in the electrically exploding wires, i.e., a current transition from the highly resistive wire core to the highly conductive plasma. It was shown that the inductive contribution to the voltage of the X-pinch is less than the resistive contribution. For the wires we used, the wires' material and diameter have no strong influence on the resistance of the X-pinch, which may be explained by the fact that the current flows through the plasma rather than through the metallic wire itself. As a result, the current is almost equally divided between two parallel X-pinches even though the diameter and material of the wires used for these two X-pinches are significantly different. (physics of gases, plasmas, and electric discharges)

  14. Determination of Serotypes and Antibiotic Resistance in Streptococcus Pneumoniae

    Directory of Open Access Journals (Sweden)

    Deniz Akgun Karapinar

    2016-01-01

    Full Text Available Aim: In this study, the distribution of serogroup/serotype and antibiotic susceptibility testing of Streptococcus pneumoniae strains, recovered from pediatric and adult patients were evaluated. Material and Method: A total of 80 clinical isolates recovered from 19 pediatric and 61 adult patients were performed by latex aglutination method and antibiotic susceptibility tests in Istanbul University, Istanbul Faculty of Medicine, Medical Microbiology Laboratories. Results: Sixty-two strains (76 %, were serogroup/serotyped and 18 (23 % strains couldn%u2019t serogroup/serotyped. The most frequent identified serogroups were 19, 14, 23, 6, 4 in pediatrics, and 3, 19, 23 and 9 in adults. In adults, serogroups 3, 9, 5, 8, 18, 1, 15 were determined, but these serogroups weren%u2019t found in pediatrics. Vaccine serotypes rates were found as 53 % in pediatric and as 85 % in adults. The serogroups 2, 7, 10, 11, 12, 17, 20, 22, 33 were not detected, which are available in vaccine serotypes. Only 1 (1 % strain was found to exhibit low level resistance to penicillin and high level resistance wasn%u2019t found in any strain. Resistant results for trimethoprim-sulfamethoxazole, erythromycin, chloramphenicol and ofloxacin were found as 45 (56 %, 22 (27.5 %, 7 (9 %, 2 (2.5 %, respectively. All strains were found susceptible to vancomycin, linezolid and levofloxacin. The most resistant serogroups were 19, 23, 9 and 14 in the tested antibiotics. Multidrug resistance was found in 9 (11 % strains and these strains were found as serogroups 19, 23, 9, 6 and 14. Discussion: The epidemiological studies are important that the distribution of serotype and antibiotic resistance vary depending on many factors like age, and geographic region.

  15. A Genome-Wide Association Study Reveals Genes Associated with Fusarium Ear Rot Resistance in a Maize Core Diversity Panel

    Science.gov (United States)

    Zila, Charles T.; Samayoa, L. Fernando; Santiago, Rogelio; Butrón, Ana; Holland, James B.

    2013-01-01

    Fusarium ear rot is a common disease of maize that affects food and feed quality globally. Resistance to the disease is highly quantitative, and maize breeders have difficulty incorporating polygenic resistance alleles from unadapted donor sources into elite breeding populations without having a negative impact on agronomic performance. Identification of specific allele variants contributing to improved resistance may be useful to breeders by allowing selection of resistance alleles in coupling phase linkage with favorable agronomic characteristics. We report the results of a genome-wide association study to detect allele variants associated with increased resistance to Fusarium ear rot in a maize core diversity panel of 267 inbred lines evaluated in two sets of environments. We performed association tests with 47,445 single-nucleotide polymorphisms (SNPs) while controlling for background genomic relationships with a mixed model and identified three marker loci significantly associated with disease resistance in at least one subset of environments. Each associated SNP locus had relatively small additive effects on disease resistance (±1.1% on a 0–100% scale), but nevertheless were associated with 3 to 12% of the genotypic variation within or across environment subsets. Two of three identified SNPs colocalized with genes that have been implicated with programmed cell death. An analysis of associated allele frequencies within the major maize subpopulations revealed enrichment for resistance alleles in the tropical/subtropical and popcorn subpopulations compared with other temperate breeding pools. PMID:24048647

  16. A process evaluation of the UK-wide Antibiotic Guardian campaign: developing engagement on antimicrobial resistance.

    Science.gov (United States)

    Bhattacharya, Alex; Hopkins, Susan; Sallis, Anna; Budd, Emma L; Ashiru-Oredope, Diane

    2017-06-01

    Public Health England developed and led a new UK-wide pledge campaign aiming to improve behaviours around the prudent use and prescription of antibiotics. This paper presents a process evaluation for the first season of the campaign to determine the impact of the campaign and inform future campaigns. Data were collected from AntibioticGuardian.com and Google analytics between August 2014 and January 2015. The primary outcome was the decision to pledge and was assessed according to target audience, location, source and route of referral to the website. There were 47 158 unique visits to the website and 12 509 visitors made a pledge (26.5%) to become Antibiotic Guardians (AGs); 69% were healthcare professionals. Social media directed the most traffic to the website (24% of the public that signed up cited social media as how they discovered the campaign), other acquisition routes such as self-directed, email or website referral, were more effective at encouraging visitors to pledge. The campaign completed its goal of 10 000 AGs in the first year. Further work is required to improve engagement with target audiences and determine whether this campaign has an impact on antibiotic consumption and prescribing behaviour among the public and healthcare professionals. © Crown copyright 2016.

  17. Acinetobacter baumannii Isolated from Lebanese Patients: Phenotypes and Genotypes of Resistance, Clonality, and Determinants of Pathogenicity.

    Science.gov (United States)

    Dahdouh, Elias; Hajjar, Micheline; Suarez, Monica; Daoud, Ziad

    2016-01-01

    Introduction: Acinetobacter baumannii is a nosocomial pathogen that usually affects critically ill patients. High mortality rates have been associated with MDR A. baumannii infections. Carbapenem resistance among these isolates is increasing worldwide and is associated with certain International Clones (ICs) and oxacillinases (OXAs). Moreover, this organism possesses a wide range of virulence factors, whose expression is not yet fully understood. In this study, clinical A. baumannii isolates are characterized in terms of antibiotic resistance, mechanisms of carbapenem resistance, clonality, and virulence. Materials and Methods: A. baumannii clinical isolates ( n = 90) where obtained from a tertiary care center in Beirut, Lebanon. API 20NE strips in addition to the amplification of bla OXA-51-like were used for identification. Antibiotic susceptibility testing by disk diffusion was then performed in addition to PCRs for the detection of the most commonly disseminated carbapenemases. Clonality was determined by tri-locus PCR typing and doubling times were determined for isolates with varying susceptibility profiles. Biofilm formation, hemolysis, siderophore production, proteolytic activity, and surface motility was then determined for all the isolates. Statistical analysis was then performed for the determination of associations. Results and Discussion: 81 (90%) of the isolates were resistant to carbapenems. These high rates are similar to other multi-center studies in the country suggesting the need of intervention on a national level. 74 (91.3%) of the carbapenem resistant isolates harbored bla OXA-23-like including two that also harbored bla OXA-24-like . 88.9% of the A. baumannii isolates pertained to ICII and three other international clones were detected, showing the wide dissemination of clones into geographically distinct locations. Virulence profiles were highly diverse and no specific pattern was observed. Nevertheless, an association between motility

  18. Spatial and temporal country-wide survey of temephos resistance in Brazilian populations of Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Mateus Chediak

    2016-01-01

    Full Text Available The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites.

  19. DETERMINING THE THERMAL RESISTANCE OF A VENTILATED HINGED FACADE SYSTEM LAYER

    Directory of Open Access Journals (Sweden)

    Gagarin Vladimir Gennad'evich

    2015-03-01

    Full Text Available Enveloping structures with hinged façade systems are nowadays widely used for moisture control of enveloping structures, prevention of overheating of the structures by insolation, saving the constructions from atmospheric moisture and also for correspondence with the raised requirements to thermal protection of the enveloping structures, aimed also at reducing energy consumption. In the winter conditions the influence of air layer on the thermal insulation parameters is usually neglected. In the article the thermal resistance of an air gap and is considered and its effect in the calculation of the heat resistance of a building envelope with hinged facade system is analyzed in the conditions of cold weather. The thermal resistance of the air layer determines how the heat losses decrease.

  20. Determinants of foamy virus envelope glycoprotein mediated resistance to superinfection

    International Nuclear Information System (INIS)

    Berg, Angelika; Pietschmann, Thomas; Rethwilm, Axel; Lindemann, Dirk

    2003-01-01

    Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR. FV Env requires the extracellular domains of the SU and the TM subunits as well as membrane anchorage, efficient cell surface transport, and most probably correct subunit processing. This is in contrast to murine leukemia virus where secreted proteins comprising the receptor-binding domain in SU are sufficient to induce SIR. Furthermore, we demonstrate that cellular expression of the prototype FV envelope proteins induces SIR against pseudotypes with glycoproteins of other FV species, including of simian, feline, bovine, and equine origin. This implies that all of them use the same receptor molecules for viral entry

  1. Characterization of Insect Resistance Loci in the USDA Soybean Germplasm Collection Using Genome-Wide Association Studies

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    Hao-Xun Chang

    2017-05-01

    Full Text Available Management of insects that cause economic damage to yields of soybean mainly rely on insecticide applications. Sources of resistance in soybean plant introductions (PIs to different insect pests have been reported, and some of these sources, like for the soybean aphid (SBA, have been used to develop resistant soybean cultivars. With the availability of SoySNP50K and the statistical power of genome-wide association studies, we integrated phenotypic data for beet armyworm, Mexican bean beetle (MBB, potato leafhopper (PLH, SBA, soybean looper (SBL, velvetbean caterpillar (VBC, and chewing damage caused by unspecified insects for a comprehensive understanding of insect resistance in the United States Department of Agriculture Soybean Germplasm Collection. We identified significant single nucleotide (SNP polymorphic markers for MBB, PLH, SBL, and VBC, and we highlighted several leucine-rich repeat-containing genes and myeloblastosis transcription factors within the high linkage disequilibrium region surrounding significant SNP markers. Specifically for soybean resistance to PLH, we found the PLH locus is close but distinct to a locus for soybean pubescence density on chromosome 12. The results provide genetic support that pubescence density may not directly link to PLH resistance. This study offers a novel insight of soybean resistance to four insect pests and reviews resistance mapping studies for major soybean insects.

  2. Postulation of rust resistance genes in Nordic spring wheat genotypes and identification of widely effective sources of resistance against the Australian rust flora.

    Science.gov (United States)

    Randhawa, Mandeep; Bansal, Urmil; Lillemo, Morten; Miah, Hanif; Bariana, Harbans

    2016-11-01

    Wild relatives, landraces and cultivars from different geographical regions have been demonstrated as the sources of genetic variation for resistance to rust diseases. This study involved assessment of diversity for resistance to three rust diseases among a set of Nordic spring wheat cultivars. These cultivars were tested at the seedling stage against several pathotypes of three rust pathogens in the greenhouse. All stage stem rust resistance genes Sr7b, Sr8a, Sr12, Sr15, Sr17, Sr23 and Sr30, and leaf rust resistance genes Lr1, Lr3a, Lr13, Lr14a, Lr16 and Lr20 were postulated either singly or in different combinations among these cultivars. A high proportion of cultivars were identified to carry linked rust resistance genes Sr15 and Lr20. Although 51 cultivars showed variation against Puccinia striiformis f. sp. tritici (Pst) pathotypes used in this study, results were not clearly contrasting to enable postulation of stripe rust resistance genes in these genotypes. Stripe rust resistance gene Yr27 was postulated in four cultivars and Yr1 was present in cultivar Zebra. Cultivar Tjalve produced low stripe rust response against all Pst pathotypes indicating the presence either of a widely effective resistance gene or combination of genes with compensating pathogenic specificities. Several cultivars carried moderate to high level of APR to leaf rust and stripe rust. Seedling stem rust susceptible cultivar Aston exhibited moderately resistant to moderately susceptible response, whereas other cultivars belonging to this class were rated moderately susceptible or higher. Molecular markers linked with APR genes Yr48, Lr34/Yr18/Sr57, Lr68 and Sr2 detected the presence of these genes in some genotypes.

  3. Low-cost ultra-wide genotyping using Roche/454 pyrosequencing for surveillance of HIV drug resistance.

    Directory of Open Access Journals (Sweden)

    Dawn M Dudley

    Full Text Available Great efforts have been made to increase accessibility of HIV antiretroviral therapy (ART in low and middle-income countries. The threat of wide-scale emergence of drug resistance could severely hamper ART scale-up efforts. Population-based surveillance of transmitted HIV drug resistance ensures the use of appropriate first-line regimens to maximize efficacy of ART programs where drug options are limited. However, traditional HIV genotyping is extremely expensive, providing a cost barrier to wide-scale and frequent HIV drug resistance surveillance.We have developed a low-cost laboratory-scale next-generation sequencing-based genotyping method to monitor drug resistance. We designed primers specifically to amplify protease and reverse transcriptase from Brazilian HIV subtypes and developed a multiplexing scheme using multiplex identifier tags to minimize cost while providing more robust data than traditional genotyping techniques. Using this approach, we characterized drug resistance from plasma in 81 HIV infected individuals collected in São Paulo, Brazil. We describe the complexities of analyzing next-generation sequencing data and present a simplified open-source workflow to analyze drug resistance data. From this data, we identified drug resistance mutations in 20% of treatment naïve individuals in our cohort, which is similar to frequencies identified using traditional genotyping in Brazilian patient samples.The developed ultra-wide sequencing approach described here allows multiplexing of at least 48 patient samples per sequencing run, 4 times more than the current genotyping method. This method is also 4-fold more sensitive (5% minimal detection frequency vs. 20% at a cost 3-5× less than the traditional Sanger-based genotyping method. Lastly, by using a benchtop next-generation sequencer (Roche/454 GS Junior, this approach can be more easily implemented in low-resource settings. This data provides proof-of-concept that next

  4. Genome-wide mutagenesis and multi-drug resistance in American trypanosomes induced by the front-line drug benznidazole

    KAUST Repository

    Campos, Mônica C.

    2017-10-25

    Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and affects 5–8 million people in Latin America. Although the nitroheterocyclic compound benznidazole has been the front-line drug for several decades, treatment failures are common. Benznidazole is a pro-drug and is bio-activated within the parasite by the mitochondrial nitroreductase TcNTR-1, leading to the generation of reactive metabolites that have trypanocidal activity. To better assess drug action and resistance, we sequenced the genomes of T. cruzi Y strain (35.5 Mb) and three benznidazole-resistant clones derived from a single drug-selected population. This revealed the genome-wide accumulation of mutations in the resistant parasites, in addition to variations in DNA copy-number. We observed mutations in DNA repair genes, linked with increased susceptibility to DNA alkylating and inter-strand cross-linking agents. Stop-codon-generating mutations in TcNTR-1 were associated with cross-resistance to other nitroheterocyclic drugs. Unexpectedly, the clones were also highly resistant to the ergosterol biosynthesis inhibitor posaconazole, a drug proposed for use against T. cruzi infections, in combination with benznidazole. Our findings therefore identify the highly mutagenic activity of benznidazole metabolites in T. cruzi, demonstrate that this can result in multi-drug resistance, and indicate that vigilance will be required if benznidazole is used in combination therapy.

  5. Tutorial: Determination of thermal boundary resistance by molecular dynamics simulations

    Science.gov (United States)

    Liang, Zhi; Hu, Ming

    2018-05-01

    Due to the high surface-to-volume ratio of nanostructured components in microelectronics and other advanced devices, the thermal resistance at material interfaces can strongly affect the overall thermal behavior in these devices. Therefore, the thermal boundary resistance, R, must be taken into account in the thermal analysis of nanoscale structures and devices. This article is a tutorial on the determination of R and the analysis of interfacial thermal transport via molecular dynamics (MD) simulations. In addition to reviewing the commonly used equilibrium and non-equilibrium MD models for the determination of R, we also discuss several MD simulation methods which can be used to understand interfacial thermal transport behavior. To illustrate how these MD models work for various interfaces, we will show several examples of MD simulation results on thermal transport across solid-solid, solid-liquid, and solid-gas interfaces. The advantages and drawbacks of a few other MD models such as approach-to-equilibrium MD and first-principles MD are also discussed.

  6. A genome-wide association study of resistance to HIV infection in highly exposed uninfected individuals with hemophilia A

    Science.gov (United States)

    Lane, Jérôme; McLaren, Paul J.; Dorrell, Lucy; Shianna, Kevin V.; Stemke, Amanda; Pelak, Kimberly; Moore, Stephen; Oldenburg, Johannes; Alvarez-Roman, Maria Teresa; Angelillo-Scherrer, Anne; Boehlen, Francoise; Bolton-Maggs, Paula H.B.; Brand, Brigit; Brown, Deborah; Chiang, Elaine; Cid-Haro, Ana Rosa; Clotet, Bonaventura; Collins, Peter; Colombo, Sara; Dalmau, Judith; Fogarty, Patrick; Giangrande, Paul; Gringeri, Alessandro; Iyer, Rathi; Katsarou, Olga; Kempton, Christine; Kuriakose, Philip; Lin, Judith; Makris, Mike; Manco-Johnson, Marilyn; Tsakiris, Dimitrios A.; Martinez-Picado, Javier; Mauser-Bunschoten, Evelien; Neff, Anne; Oka, Shinichi; Oyesiku, Lara; Parra, Rafael; Peter-Salonen, Kristiina; Powell, Jerry; Recht, Michael; Shapiro, Amy; Stine, Kimo; Talks, Katherine; Telenti, Amalio; Wilde, Jonathan; Yee, Thynn Thynn; Wolinsky, Steven M.; Martinson, Jeremy; Hussain, Shehnaz K.; Bream, Jay H.; Jacobson, Lisa P.; Carrington, Mary; Goedert, James J.; Haynes, Barton F.; McMichael, Andrew J.; Goldstein, David B.; Fellay, Jacques

    2013-01-01

    Human genetic variation contributes to differences in susceptibility to HIV-1 infection. To search for novel host resistance factors, we performed a genome-wide association study (GWAS) in hemophilia patients highly exposed to potentially contaminated factor VIII infusions. Individuals with hemophilia A and a documented history of factor VIII infusions before the introduction of viral inactivation procedures (1979–1984) were recruited from 36 hemophilia treatment centers (HTCs), and their genome-wide genetic variants were compared with those from matched HIV-infected individuals. Homozygous carriers of known CCR5 resistance mutations were excluded. Single nucleotide polymorphisms (SNPs) and inferred copy number variants (CNVs) were tested using logistic regression. In addition, we performed a pathway enrichment analysis, a heritability analysis, and a search for epistatic interactions with CCR5 Δ32 heterozygosity. A total of 560 HIV-uninfected cases were recruited: 36 (6.4%) were homozygous for CCR5 Δ32 or m303. After quality control and SNP imputation, we tested 1 081 435 SNPs and 3686 CNVs for association with HIV-1 serostatus in 431 cases and 765 HIV-infected controls. No SNP or CNV reached genome-wide significance. The additional analyses did not reveal any strong genetic effect. Highly exposed, yet uninfected hemophiliacs form an ideal study group to investigate host resistance factors. Using a genome-wide approach, we did not detect any significant associations between SNPs and HIV-1 susceptibility, indicating that common genetic variants of major effect are unlikely to explain the observed resistance phenotype in this population. PMID:23372042

  7. Distribution of resistance genetic determinants among Vibrio cholerae isolates of 2012 and 2013 outbreaks in IR Iran.

    Science.gov (United States)

    Rezaie, Niloofar; Bakhshi, Bita; Najar-Peerayeh, Shahin

    2017-03-01

    The objective of this study was to characterize antimicrobial resistance determinants in relation to antimicrobial susceptibility and genotyping profile in 20 clinical isolates of Vibrio cholerae. All of the isolates were resistant to streptomycin. The second most prevalent resistance was observed to trimethoprim (75%), co-trimoxazole (60%), tetracycline (50%), and minocycline (45%). About 50% of the isolates fulfilled the criteria of Multi Drug Resistance (MDR) phenotype. None of the isolates carried tet A, B, C, and, D determinants. This finding shows that tetracycline resistance determinants recognized so far, does not satisfactorily describe the 50% tetracycline resistance phenotype in this study, suggesting the possible contribution of other not yet characterized resistance mechanisms involved. Class 1 integron, widely distributed among enteric bacteria, was not detected among V. cholerae strains under study. Conversely, 100% of the isolates harbored SXT constin (int) , among which 70% were positive for dfrA1, strA, and strB genes. The sul1gene was present in 60% of the isolates while none of them contained floR gene. All the isolates uniformly appeared to be identical in fingerprinting profiles expected from outbreak strains. In conclusion, SXT element with its mosaic structure was the exclusive antimicrobial resistance determinant of clonal V. cholerae isolates taken from outbreaks of 2012 and 2013 in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Genome-wide RNAi screen reveals the E3 SUMO-protein ligase gene SIZ1 as a novel determinant of furfural tolerance in Saccharomyces cerevisiae

    OpenAIRE

    Xiao, Han; Zhao, Huimin

    2014-01-01

    Background Furfural is a major growth inhibitor in lignocellulosic hydrolysates and improving furfural tolerance of microorganisms is critical for rapid and efficient fermentation of lignocellulosic biomass. In this study, we used the RNAi-Assisted Genome Evolution (RAGE) method to select for furfural resistant mutants of Saccharomyces cerevisiae, and identified a new determinant of furfural tolerance. Results By using a genome-wide RNAi (RNA-interference) screen in S. cerevisiae for genes in...

  9. A genome-wide approach accounting for body mass index identifies genetic variants influencing fasting glycemic traits and insulin resistance

    Science.gov (United States)

    Manning, Alisa K.; Hivert, Marie-France; Scott, Robert A.; Grimsby, Jonna L.; Bouatia-Naji, Nabila; Chen, Han; Rybin, Denis; Liu, Ching-Ti; Bielak, Lawrence F.; Prokopenko, Inga; Amin, Najaf; Barnes, Daniel; Cadby, Gemma; Hottenga, Jouke-Jan; Ingelsson, Erik; Jackson, Anne U.; Johnson, Toby; Kanoni, Stavroula; Ladenvall, Claes; Lagou, Vasiliki; Lahti, Jari; Lecoeur, Cecile; Liu, Yongmei; Martinez-Larrad, Maria Teresa; Montasser, May E.; Navarro, Pau; Perry, John R. B.; Rasmussen-Torvik, Laura J.; Salo, Perttu; Sattar, Naveed; Shungin, Dmitry; Strawbridge, Rona J.; Tanaka, Toshiko; van Duijn, Cornelia M.; An, Ping; de Andrade, Mariza; Andrews, Jeanette S.; Aspelund, Thor; Atalay, Mustafa; Aulchenko, Yurii; Balkau, Beverley; Bandinelli, Stefania; Beckmann, Jacques S.; Beilby, John P.; Bellis, Claire; Bergman, Richard N.; Blangero, John; Boban, Mladen; Boehnke, Michael; Boerwinkle, Eric; Bonnycastle, Lori L.; Boomsma, Dorret I.; Borecki, Ingrid B.; Böttcher, Yvonne; Bouchard, Claude; Brunner, Eric; Budimir, Danijela; Campbell, Harry; Carlson, Olga; Chines, Peter S.; Clarke, Robert; Collins, Francis S.; Corbatón-Anchuelo, Arturo; Couper, David; de Faire, Ulf; Dedoussis, George V; Deloukas, Panos; Dimitriou, Maria; Egan, Josephine M; Eiriksdottir, Gudny; Erdos, Michael R.; Eriksson, Johan G.; Eury, Elodie; Ferrucci, Luigi; Ford, Ian; Forouhi, Nita G.; Fox, Caroline S; Franzosi, Maria Grazia; Franks, Paul W; Frayling, Timothy M; Froguel, Philippe; Galan, Pilar; de Geus, Eco; Gigante, Bruna; Glazer, Nicole L.; Goel, Anuj; Groop, Leif; Gudnason, Vilmundur; Hallmans, Göran; Hamsten, Anders; Hansson, Ola; Harris, Tamara B.; Hayward, Caroline; Heath, Simon; Hercberg, Serge; Hicks, Andrew A.; Hingorani, Aroon; Hofman, Albert; Hui, Jennie; Hung, Joseph; Jarvelin, Marjo Riitta; Jhun, Min A.; Johnson, Paul C.D.; Jukema, J Wouter; Jula, Antti; Kao, W.H.; Kaprio, Jaakko; Kardia, Sharon L. R.; Keinanen-Kiukaanniemi, Sirkka; Kivimaki, Mika; Kolcic, Ivana; Kovacs, Peter; Kumari, Meena; Kuusisto, Johanna; Kyvik, Kirsten Ohm; Laakso, Markku; Lakka, Timo; Lannfelt, Lars; Lathrop, G Mark; Launer, Lenore J.; Leander, Karin; Li, Guo; Lind, Lars; Lindstrom, Jaana; Lobbens, Stéphane; Loos, Ruth J. F.; Luan, Jian’an; Lyssenko, Valeriya; Mägi, Reedik; Magnusson, Patrik K. E.; Marmot, Michael; Meneton, Pierre; Mohlke, Karen L.; Mooser, Vincent; Morken, Mario A.; Miljkovic, Iva; Narisu, Narisu; O’Connell, Jeff; Ong, Ken K.; Oostra, Ben A.; Palmer, Lyle J.; Palotie, Aarno; Pankow, James S.; Peden, John F.; Pedersen, Nancy L.; Pehlic, Marina; Peltonen, Leena; Penninx, Brenda; Pericic, Marijana; Perola, Markus; Perusse, Louis; Peyser, Patricia A; Polasek, Ozren; Pramstaller, Peter P.; Province, Michael A.; Räikkönen, Katri; Rauramaa, Rainer; Rehnberg, Emil; Rice, Ken; Rotter, Jerome I.; Rudan, Igor; Ruokonen, Aimo; Saaristo, Timo; Sabater-Lleal, Maria; Salomaa, Veikko; Savage, David B.; Saxena, Richa; Schwarz, Peter; Seedorf, Udo; Sennblad, Bengt; Serrano-Rios, Manuel; Shuldiner, Alan R.; Sijbrands, Eric J.G.; Siscovick, David S.; Smit, Johannes H.; Small, Kerrin S.; Smith, Nicholas L.; Smith, Albert Vernon; Stančáková, Alena; Stirrups, Kathleen; Stumvoll, Michael; Sun, Yan V.; Swift, Amy J.; Tönjes, Anke; Tuomilehto, Jaakko; Trompet, Stella; Uitterlinden, Andre G.; Uusitupa, Matti; Vikström, Max; Vitart, Veronique; Vohl, Marie-Claude; Voight, Benjamin F.; Vollenweider, Peter; Waeber, Gerard; Waterworth, Dawn M; Watkins, Hugh; Wheeler, Eleanor; Widen, Elisabeth; Wild, Sarah H.; Willems, Sara M.; Willemsen, Gonneke; Wilson, James F.; Witteman, Jacqueline C.M.; Wright, Alan F.; Yaghootkar, Hanieh; Zelenika, Diana; Zemunik, Tatijana; Zgaga, Lina; Wareham, Nicholas J.; McCarthy, Mark I.; Barroso, Ines; Watanabe, Richard M.; Florez, Jose C.; Dupuis, Josée; Meigs, James B.; Langenberg, Claudia

    2013-01-01

    Recent genome-wide association studies have described many loci implicated in type 2 diabetes (T2D) pathophysiology and beta-cell dysfunction, but contributed little to our understanding of the genetic basis of insulin resistance. We hypothesized that genes implicated in insulin resistance pathways may be uncovered by accounting for differences in body mass index (BMI) and potential interaction between BMI and genetic variants. We applied a novel joint meta-analytical approach to test associations with fasting insulin (FI) and glucose (FG) on a genome-wide scale. We present six previously unknown FI loci at P<5×10−8 in combined discovery and follow-up analyses of 52 studies comprising up to 96,496non-diabetic individuals. Risk variants were associated with higher triglyceride and lower HDL cholesterol levels, suggestive of a role for these FI loci in insulin resistance pathways. The localization of these additional loci will aid further characterization of the role of insulin resistance in T2D pathophysiology. PMID:22581228

  10. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L..

    Directory of Open Access Journals (Sweden)

    Juliana Morini Küpper Cardoso Perseguini

    Full Text Available The common bean (Phaseolus vulgaris L. is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum and angular leaf spot (ALS; Pseudocercospora griseola are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will

  11. Genome-Wide Association Studies of Anthracnose and Angular Leaf Spot Resistance in Common Bean (Phaseolus vulgaris L.).

    Science.gov (United States)

    Perseguini, Juliana Morini Küpper Cardoso; Oblessuc, Paula Rodrigues; Rosa, João Ricardo Bachega Feijó; Gomes, Kleber Alves; Chiorato, Alisson Fernando; Carbonell, Sérgio Augusto Morais; Garcia, Antonio Augusto Franco; Vianello, Rosana Pereira; Benchimol-Reis, Luciana Lasry

    2016-01-01

    The common bean (Phaseolus vulgaris L.) is the world's most important legume for human consumption. Anthracnose (ANT; Colletotrichum lindemuthianum) and angular leaf spot (ALS; Pseudocercospora griseola) are complex diseases that cause major yield losses in common bean. Depending on the cultivar and environmental conditions, anthracnose and angular leaf spot infections can reduce crop yield drastically. This study aimed to estimate linkage disequilibrium levels and identify quantitative resistance loci (QRL) controlling resistance to both ANT and ALS diseases of 180 accessions of common bean using genome-wide association analysis. A randomized complete block design with four replicates was performed for the ANT and ALS experiments, with four plants per genotype in each replicate. Association mapping analyses were performed for ANT and ALS using a mixed linear model approach implemented in TASSEL. A total of 17 and 11 significant statistically associations involving SSRs were detected for ANT and ALS resistance loci, respectively. Using SNPs, 21 and 17 significant statistically associations were obtained for ANT and angular ALS, respectively, providing more associations with this marker. The SSR-IAC167 and PvM95 markers, both located on chromosome Pv03, and the SNP scaffold00021_89379, were associated with both diseases. The other markers were distributed across the entire common bean genome, with chromosomes Pv03 and Pv08 showing the greatest number of loci associated with ANT resistance. The chromosome Pv04 was the most saturated one, with six markers associated with ALS resistance. The telomeric region of this chromosome showed four markers located between approximately 2.5 Mb and 4.4 Mb. Our results demonstrate the great potential of genome-wide association studies to identify QRLs related to ANT and ALS in common bean. The results indicate a quantitative and complex inheritance pattern for both diseases in common bean. Our findings will contribute to more

  12. Strategies for transferring resistance into wheat: from wide crosses to GM cassettes

    Directory of Open Access Journals (Sweden)

    Brande B. H. Wulff

    2014-12-01

    Full Text Available The domestication of wheat in the Fertile Crescent 10,000 years ago led to a genetic bottleneck. Modern agriculture has further narrowed the genetic base by introducing extreme levels of uniformity on a vast spatial and temporal scale. This reduction in genetic complexity renders the crop vulnerable to new and emerging pests and pathogens. The wild relatives of wheat represent an important source of genetic variation for disease resistance. For nearly a century farmers, breeders, and cytogeneticists have sought to access this variation for crop improvement. Several barriers restricting interspecies hybridization and introgression have been overcome, providing the opportunity to tap an extensive reservoir of genetic diversity. Resistance has been introgressed into wheat from at least 52 species from 13 genera, demonstrating the remarkable plasticity of the wheat genome and the importance of such natural variation in wheat breeding. Two main problems hinder the effective deployment of introgressed resistance genes for crop improvement: (1 the simultaneous introduction of genetically linked deleterious traits and (2 the rapid breakdown of resistance when deployed individually. In this review we discuss how recent advances in molecular genomics are providing new opportunities to overcome these problems.

  13. Genome-wide association study of anthracnose resistance in Andean beans

    Science.gov (United States)

    Anthracnose is a seed-borne disease of common bean (Phaseolus vulgaris L.) caused by the fungus Colletotrichum lindemuthianum, and the pathogen is cosmopolitan in distribution. The objectives of this study were to identify new sources of anthracnose resistance in a diverse panel of 230 Andean beans ...

  14. Genome-Wide Association Mapping of and Aspergillus flavus Aflatoxin Accumulation Resistance in Maize

    Science.gov (United States)

    Marilyn L. Warburton; Juliet D. Tang; Gary L. Windham; Leigh K. Hawkins; Seth C. Murray; Wenwei Xu; Debbie Boykin; Andy Perkins; W. Paul Williams

    2015-01-01

    Contamination of maize (Zea mays L.) with aflatoxin, produced by the fungus Aspergillus flavus Link, has severe health and economic consequences. Efforts to reduce aflatoxin accumulation in maize have focused on identifying and selecting germplasm with natural host resistance factors, and several maize lines with significantly...

  15. Determinants of Generic vs. Brand Drug Choice: Evidence from Population-wide Danish Data

    DEFF Research Database (Denmark)

    Skipper, Niels; Vejlin, Rune Majlund

    driven. We use population-wide Danish register data including all prescriptions for seven blockbuster drugs from 1998-2008. At the outset, descriptive statistics suggest large variation in drug choice over doctors. Nonetheless, using a two-way fixed effects model we find that the primary determinants...... of brand drug use are unobserved patient characteristics and price effects, while observed and unobserved doctor characteristics in general explain only 0.7 % of the variation in drug choice. This is suggestive evidence that the doctors in the Danish setting with no incentives to push expensive brand drugs...

  16. Determination of oil in seeds by a wide line NMR instrument

    International Nuclear Information System (INIS)

    Marton, Aurel

    1983-01-01

    The oil content of sunflower, rape and soybean seeds was determined by a wide line NMR instrument. Using various model systems the following conclusions were drawn: the sensitivity of the instrument is much higher for the oil content of the seeds than for their water content. This observation can be interpreted in terms of the longer relaxation time of the water protons. The quantitative determination of the oil content of the seeds can be done with a high accuracy provided that the calibration curve for the respective oil is available and the signal of the solid state components of the seeds is corrected. If the water content of the seeds is reduced below 5 per cent, the oil content values obtained by NMR and extraction techniques are in agreement within the experimental error. (author)

  17. Genome-Wide Association Mapping for Resistance to Leaf and Stripe Rust in Winter-Habit Hexaploid Wheat Landraces.

    Directory of Open Access Journals (Sweden)

    Albert Kertho

    Full Text Available Leaf rust, caused by Puccinia triticina (Pt, and stripe rust, caused by P. striiformis f. sp. tritici (Pst, are destructive foliar diseases of wheat worldwide. Breeding for disease resistance is the preferred strategy of managing both diseases. The continued emergence of new races of Pt and Pst requires a constant search for new sources of resistance. Here we report a genome-wide association analysis of 567 winter wheat (Triticum aestivum landrace accessions using the Infinium iSelect 9K wheat SNP array to identify loci associated with seedling resistance to five races of Pt (MDCL, MFPS, THBL, TDBG, and TBDJ and one race of Pst (PSTv-37 frequently found in the Northern Great Plains of the United States. Mixed linear models identified 65 and eight significant markers associated with leaf rust and stripe rust, respectively. Further, we identified 31 and three QTL associated with resistance to Pt and Pst, respectively. Eleven QTL, identified on chromosomes 3A, 4A, 5A, and 6D, are previously unknown for leaf rust resistance in T. aestivum.

  18. A comparison of the wide gap and narrow gap resistive plate chamber

    International Nuclear Information System (INIS)

    Cerron Zeballos, E.; Crotty, I.; Hatzifotiadou, D.; Valverde, J.L.; Neupane, S.; Peskov, V.; Singh, S.; Williams, M.C.S.; Zichichi, A.

    1996-01-01

    In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances. (orig.)

  19. A comparison of the wide gap and narrow gap resistive plate chamber

    CERN Document Server

    Cerron-Zeballos, E; Hatzifotiadou, D; Lamas-Valverde, J; Neupane, S; Peskov, Vladimir; Singh, S; Williams, M C S; Zichichi, Antonino

    1996-01-01

    In this paper we study the performance of a wide gap RPC and compare it with that of a narrow gap RPC, both operated in avalanche mode. We have studied the total charge produced in the avalanche. We have measured the dependence of the performance with rate. In addition we have considered the effect of the tolerance of gas gap and calculated the power dissipated in these two types of RPC. We find that the narrow gap RPC has better timing ability; however the wide gap has superior rate capability, lower power dissipation in the gas volume and can be constructed with less stringent mechanical tolerances.

  20. Standard practice for determining rail-to-Earth resistance

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers the procedures necessary to follow for measuring resistance-to-earth of the running rails which are used as the conductors for returning the train operating current to the substation in electric mass transit systems. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Allelic variation of bile salt hydrolase genes in Lactobacillus salivarius does not determine bile resistance levels.

    LENUS (Irish Health Repository)

    Fang, Fang

    2009-09-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

  2. Genome-wide association links candidate genes to resistance to Plum Pox Virus in apricot (Prunus armeniaca).

    Science.gov (United States)

    Mariette, Stéphanie; Wong Jun Tai, Fabienne; Roch, Guillaume; Barre, Aurélien; Chague, Aurélie; Decroocq, Stéphane; Groppi, Alexis; Laizet, Yec'han; Lambert, Patrick; Tricon, David; Nikolski, Macha; Audergon, Jean-Marc; Abbott, Albert G; Decroocq, Véronique

    2016-01-01

    In fruit tree species, many important traits have been characterized genetically by using single-family descent mapping in progenies segregating for the traits. However, most mapped loci have not been sufficiently resolved to the individual genes due to insufficient progeny sizes for high resolution mapping and the previous lack of whole-genome sequence resources of the study species. To address this problem for Plum Pox Virus (PPV) candidate resistance gene identification in Prunus species, we implemented a genome-wide association (GWA) approach in apricot. This study exploited the broad genetic diversity of the apricot (Prunus armeniaca) germplasm containing resistance to PPV, next-generation sequence-based genotyping, and the high-quality peach (Prunus persica) genome reference sequence for single nucleotide polymorphism (SNP) identification. The results of this GWA study validated previously reported PPV resistance quantitative trait loci (QTL) intervals, highlighted other potential resistance loci, and resolved each to a limited set of candidate genes for further study. This work substantiates the association genetics approach for resolution of QTL to candidate genes in apricot and suggests that this approach could simplify identification of other candidate genes for other marked trait intervals in this germplasm. © 2015 INRA, UMR 1332 BFP New Phytologist © 2015 New Phytologist Trust.

  3. Crack resistance curves determination of tube cladding material

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, J. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)]. E-mail: johannes.bertsch@psi.ch; Hoffelner, W. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2006-06-30

    Zirconium based alloys have been in use as fuel cladding material in light water reactors since many years. As claddings change their mechanical properties during service, it is essential for the assessment of mechanical integrity to provide parameters for potential rupture behaviour. Usually, fracture mechanics parameters like the fracture toughness K {sub IC} or, for high plastic strains, the J-integral based elastic-plastic fracture toughness J {sub IC} are employed. In claddings with a very small wall thickness the determination of toughness needs the extension of the J-concept beyond limits of standards. In the paper a new method based on the traditional J approach is presented. Crack resistance curves (J-R curves) were created for unirradiated thin walled Zircaloy-4 and aluminium cladding tube pieces at room temperature using the single sample method. The procedure of creating sharp fatigue starter cracks with respect to optical recording was optimized. It is shown that the chosen test method is appropriate for the determination of complete J-R curves including the values J {sub 0.2} (J at 0.2 mm crack length), J {sub m} (J corresponding to the maximum load) and the slope of the curve.

  4. Widespread distribution of a tet W determinant among tetracycline-resistant isolates of the animal pathogen Arcanobacterium pyogenes.

    Science.gov (United States)

    Billington, Stephen J; Songer, J Glenn; Jost, B Helen

    2002-05-01

    Tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen Arcanobacterium pyogenes. The tetracycline resistance determinant cloned from two bovine isolates of A. pyogenes was highly similar at the DNA level (92% identity) to the tet(W) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium Butyrivibrio fibrisolvens. The tet(W) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it is a widely distributed determinant of tetracycline resistance in this organism. In 25% of tetracycline-resistant isolates, the tet(W) gene was associated with a mob gene, encoding a functional mobilization protein, and an origin of transfer, suggesting that the determinant may be transferable to other bacteria. In fact, low-frequency transfer of tet(W) was detected from mob+ A. pyogenes isolates to a tetracycline-sensitive A. pyogenes recipient. The mobile nature of this determinant and the presence of A. pyogenes in the gastrointestinal tract of cattle and pigs suggest that A. pyogenes may have inherited this determinant within the gastrointestinal tracts of these animals.

  5. Determination of ductile tearing resistance J-R curves in welded joints; Determination de courbes de resistance a la dechirure ductile dans les joints soudes

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, Ph.; Ould, P. [AREVA NP, Tour AREVA, 92086 Paris La Defense (France); Marie, St. [CEA Saclay, DM2S, 91191 Gif sur Yvette Cedex (France)

    2010-05-15

    The ductile tearing resistance of steels is generally characterized in terms of resistance curves giving the increase of a resistance parameter such as the crack driving force J or a crack opening displacement as a function of the crack extension {Delta}a. Welded joints are often the weakest part of structures because of greater risk of defects, heterogeneity of the microstructure of the weld, strain concentration along mismatched interfaces. This paper recalls the transferability issues common to all integrity assessments based on tearing resistance curves and points out the difficulties of characterization specific to welds. Several recommendations are proposed for the experimental determination of tearing resistance of welded joints. (authors)

  6. Genome-Wide Association Study Reveals Natural Variations Contributing to Drought Resistance in Crops

    Directory of Open Access Journals (Sweden)

    Hongwei Wang

    2017-06-01

    Full Text Available Crops are often cultivated in regions where they will face environmental adversities; resulting in substantial yield loss which can ultimately lead to food and societal problems. Thus, significant efforts have been made to breed stress tolerant cultivars in an attempt to minimize these problems and to produce more stability with respect to crop yields across broad geographies. Since stress tolerance is a complex and multi-genic trait, advancements with classical breeding approaches have been challenging. On the other hand, molecular breeding, which is based on transgenics, marker-assisted selection and genome editing technologies; holds great promise to enable farmers to better cope with these challenges. However, identification of the key genetic components underlying the trait is critical and will serve as the foundation for future crop genetic improvement. Recently, genome-wide association studies have made significant contributions to facilitate the discovery of natural variation contributing to stress tolerance in crops. From these studies, the identified loci can serve as targets for genomic selection or editing to enable the molecular design of new cultivars. Here, we summarize research progress on this issue and focus on the genetic basis of drought tolerance as revealed by genome-wide association studies and quantitative trait loci mapping. Although many favorable loci have been identified, elucidation of their molecular mechanisms contributing to increased stress tolerance still remains a challenge. Thus, continuous efforts are still required to functionally dissect this complex trait through comprehensive approaches, such as system biological studies. It is expected that proper application of the acquired knowledge will enable the development of stress tolerant cultivars; allowing agricultural production to become more sustainable under dynamic environmental conditions.

  7. Genome-Wide Association Study of the Genetic Determinants of Emphysema Distribution.

    Science.gov (United States)

    Boueiz, Adel; Lutz, Sharon M; Cho, Michael H; Hersh, Craig P; Bowler, Russell P; Washko, George R; Halper-Stromberg, Eitan; Bakke, Per; Gulsvik, Amund; Laird, Nan M; Beaty, Terri H; Coxson, Harvey O; Crapo, James D; Silverman, Edwin K; Castaldi, Peter J; DeMeo, Dawn L

    2017-03-15

    Emphysema has considerable variability in the severity and distribution of parenchymal destruction throughout the lungs. Upper lobe-predominant emphysema has emerged as an important predictor of response to lung volume reduction surgery. Yet, aside from alpha-1 antitrypsin deficiency, the genetic determinants of emphysema distribution remain largely unknown. To identify the genetic influences of emphysema distribution in non-alpha-1 antitrypsin-deficient smokers. A total of 11,532 subjects with complete genotype and computed tomography densitometry data in the COPDGene (Genetic Epidemiology of Chronic Obstructive Pulmonary Disease [COPD]; non-Hispanic white and African American), ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints), and GenKOLS (Genetics of Chronic Obstructive Lung Disease) studies were analyzed. Two computed tomography scan emphysema distribution measures (difference between upper-third and lower-third emphysema; ratio of upper-third to lower-third emphysema) were tested for genetic associations in all study subjects. Separate analyses in each study population were followed by a fixed effect metaanalysis. Single-nucleotide polymorphism-, gene-, and pathway-based approaches were used. In silico functional evaluation was also performed. We identified five loci associated with emphysema distribution at genome-wide significance. These loci included two previously reported associations with COPD susceptibility (4q31 near HHIP and 15q25 near CHRNA5) and three new associations near SOWAHB, TRAPPC9, and KIAA1462. Gene set analysis and in silico functional evaluation revealed pathways and cell types that may potentially contribute to the pathogenesis of emphysema distribution. This multicohort genome-wide association study identified new genomic loci associated with differential emphysematous destruction throughout the lungs. These findings may point to new biologic pathways on which to expand diagnostic and therapeutic

  8. A genome-wide RNAi screen identifies novel targets of neratinib resistance leading to identification of potential drug resistant genetic markers.

    Science.gov (United States)

    Seyhan, Attila A; Varadarajan, Usha; Choe, Sung; Liu, Wei; Ryan, Terence E

    2012-04-01

    Neratinib (HKI-272) is a small molecule tyrosine kinase inhibitor of the ErbB receptor family currently in Phase III clinical trials. Despite its efficacy, the mechanism of potential cellular resistance to neratinib and genes involved with it remains unknown. We have used a pool-based lentiviral genome-wide functional RNAi screen combined with a lethal dose of neratinib to discover chemoresistant interactions with neratinib. Our screen has identified a collection of genes whose inhibition by RNAi led to neratinib resistance including genes involved in oncogenesis (e.g. RAB33A, RAB6A and BCL2L14), transcription factors (e.g. FOXP4, TFEC, ZNF), cellular ion transport (e.g. CLIC3, TRAPPC2P1, P2RX2), protein ubiquitination (e.g. UBL5), cell cycle (e.g. CCNF), and genes known to interact with breast cancer-associated genes (e.g. CCNF, FOXP4, TFEC, several ZNF factors, GNA13, IGFBP1, PMEPA1, SOX5, RAB33A, RAB6A, FXR1, DDO, TFEC, OLFM2). The identification of novel mediators of cellular resistance to neratinib could lead to the identification of new or neoadjuvant drug targets. Their use as patient or treatment selection biomarkers could make the application of anti-ErbB therapeutics more clinically effective.

  9. Transferable chloramphenicol resistance determinant in luminous Vibrio harveyi from penaeid shrimp Penaeus monodon larvae

    Directory of Open Access Journals (Sweden)

    Thangapalam Jawahar Abraham

    2016-12-01

    Full Text Available Antibiotic-resistant luminous Vibrio harveyi strains isolated from Penaeus monodon larvae were screened for the possession of transferable resistance determinants. All the strains were resistant to chloramphenicol and the determinant coding for chloramphenicol resistance was transferred to Escherichia coli at frequencies of 9.50x10-4 to 4.20x10-4. The results probably suggest the excessive use of chloramphenicol in shrimp hatcheries to combat luminous vibriosis.

  10. The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Petersen, Andreas

    2007-01-01

    Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... and Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

  11. Molecular screening of antibiotic-resistant determinants among ...

    African Journals Online (AJOL)

    Background: Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating problem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. Objectives: This study screened for presence of ...

  12. Genetic determinants of antifungal resistance in Candida species ...

    African Journals Online (AJOL)

    In the previous decades, it has been an increase in cases of resistance to antifungal agents used in the prophylaxis and treatment of infections caused by Candida species. The emergence of resistance to drug classes, it is usually explained by genome alterations ranging from point mutations to gain or loss of whole ...

  13. Detection of mutations in quinolone-resistant determining regions in ...

    African Journals Online (AJOL)

    Yomi

    2012-01-16

    Jan 16, 2012 ... Since the use of fluoroquinolone antibiotic in clinical practice was introduced about two decades ago, quinolone-resistant E. coli strains .... containing dehydrated antibiotics (Merlin Diagnostika, Germany) in two–fold dilution. .... alterations in parC play fundamental role in developing high level of resistance ...

  14. Electrical capacity and resistance determination of emitting electric transducer

    International Nuclear Information System (INIS)

    Alba Fernandez, J.; Ramis Soriano, J.

    2000-01-01

    In this work we calculate the electrical resistance and capacity of emitting electric transducer, which is mainly formed, in direct relationship with its properties, by a ceramic capacitor. Our aim is to motivate the students with an attractive element in order to carry out traditional measurements of the charge and discharge transients of a capacitor, implementing high resistance setups. (Author) 5 refs

  15. Prediction of Cacao (Theobroma cacao) Resistance to Moniliophthora spp. Diseases via Genome-Wide Association Analysis and Genomic Selection.

    Science.gov (United States)

    McElroy, Michel S; Navarro, Alberto J R; Mustiga, Guiliana; Stack, Conrad; Gezan, Salvador; Peña, Geover; Sarabia, Widem; Saquicela, Diego; Sotomayor, Ignacio; Douglas, Gavin M; Migicovsky, Zoë; Amores, Freddy; Tarqui, Omar; Myles, Sean; Motamayor, Juan C

    2018-01-01

    Cacao ( Theobroma cacao ) is a globally important crop, and its yield is severely restricted by disease. Two of the most damaging diseases, witches' broom disease (WBD) and frosty pod rot disease (FPRD), are caused by a pair of related fungi: Moniliophthora perniciosa and Moniliophthora roreri , respectively. Resistant cultivars are the most effective long-term strategy to address Moniliophthora diseases, but efficiently generating resistant and productive new cultivars will require robust methods for screening germplasm before field testing. Marker-assisted selection (MAS) and genomic selection (GS) provide two potential avenues for predicting the performance of new genotypes, potentially increasing the selection gain per unit time. To test the effectiveness of these two approaches, we performed a genome-wide association study (GWAS) and GS on three related populations of cacao in Ecuador genotyped with a 15K single nucleotide polymorphism (SNP) microarray for three measures of WBD infection (vegetative broom, cushion broom, and chirimoya pod), one of FPRD (monilia pod) and two productivity traits (total fresh weight of pods and % healthy pods produced). GWAS yielded several SNPs associated with disease resistance in each population, but none were significantly correlated with the same trait in other populations. Genomic selection, using one population as a training set to estimate the phenotypes of the remaining two (composed of different families), varied among traits, from a mean prediction accuracy of 0.46 (vegetative broom) to 0.15 (monilia pod), and varied between training populations. Simulations demonstrated that selecting seedlings using GWAS markers alone generates no improvement over selecting at random, but that GS improves the selection process significantly. Our results suggest that the GWAS markers discovered here are not sufficiently predictive across diverse germplasm to be useful for MAS, but that using all markers in a GS framework holds

  16. Prediction of Cacao (Theobroma cacao Resistance to Moniliophthora spp. Diseases via Genome-Wide Association Analysis and Genomic Selection

    Directory of Open Access Journals (Sweden)

    Michel S. McElroy

    2018-03-01

    Full Text Available Cacao (Theobroma cacao is a globally important crop, and its yield is severely restricted by disease. Two of the most damaging diseases, witches’ broom disease (WBD and frosty pod rot disease (FPRD, are caused by a pair of related fungi: Moniliophthora perniciosa and Moniliophthora roreri, respectively. Resistant cultivars are the most effective long-term strategy to address Moniliophthora diseases, but efficiently generating resistant and productive new cultivars will require robust methods for screening germplasm before field testing. Marker-assisted selection (MAS and genomic selection (GS provide two potential avenues for predicting the performance of new genotypes, potentially increasing the selection gain per unit time. To test the effectiveness of these two approaches, we performed a genome-wide association study (GWAS and GS on three related populations of cacao in Ecuador genotyped with a 15K single nucleotide polymorphism (SNP microarray for three measures of WBD infection (vegetative broom, cushion broom, and chirimoya pod, one of FPRD (monilia pod and two productivity traits (total fresh weight of pods and % healthy pods produced. GWAS yielded several SNPs associated with disease resistance in each population, but none were significantly correlated with the same trait in other populations. Genomic selection, using one population as a training set to estimate the phenotypes of the remaining two (composed of different families, varied among traits, from a mean prediction accuracy of 0.46 (vegetative broom to 0.15 (monilia pod, and varied between training populations. Simulations demonstrated that selecting seedlings using GWAS markers alone generates no improvement over selecting at random, but that GS improves the selection process significantly. Our results suggest that the GWAS markers discovered here are not sufficiently predictive across diverse germplasm to be useful for MAS, but that using all markers in a GS framework holds

  17. Improved annotation of antibiotic resistance determinants reveals microbial resistomes cluster by ecology.

    Science.gov (United States)

    Gibson, Molly K; Forsberg, Kevin J; Dantas, Gautam

    2015-01-01

    Antibiotic resistance is a dire clinical problem with important ecological dimensions. While antibiotic resistance in human pathogens continues to rise at alarming rates, the impact of environmental resistance on human health is still unclear. To investigate the relationship between human-associated and environmental resistomes, we analyzed functional metagenomic selections for resistance against 18 clinically relevant antibiotics from soil and human gut microbiota as well as a set of multidrug-resistant cultured soil isolates. These analyses were enabled by Resfams, a new curated database of protein families and associated highly precise and accurate profile hidden Markov models, confirmed for antibiotic resistance function and organized by ontology. We demonstrate that the antibiotic resistance functions that give rise to the resistance profiles observed in environmental and human-associated microbial communities significantly differ between ecologies. Antibiotic resistance functions that most discriminate between ecologies provide resistance to β-lactams and tetracyclines, two of the most widely used classes of antibiotics in the clinic and agriculture. We also analyzed the antibiotic resistance gene composition of over 6000 sequenced microbial genomes, revealing significant enrichment of resistance functions by both ecology and phylogeny. Together, our results indicate that environmental and human-associated microbial communities harbor distinct resistance genes, suggesting that antibiotic resistance functions are largely constrained by ecology.

  18. Determination of rust resistance genes in pakistani bread wheats

    International Nuclear Information System (INIS)

    Qamar, M.; Ahmad, S.D.; Rabbani, M.A.; Shinwari, Z.K.

    2014-01-01

    Stripe and leaf rusts are the major constraints to bread wheat production in Pakistan. Molecular markers were used to investigate the presence of leaf rust and stripe rust resistance gene cluster Lr34/Yr18 and stem rust resistance gene Sr2 in 52 Pakistani bread wheat cultivars/lines. PCR amplification of DNA fragments using DNA marker csLV-34 showed that 13 of the studied cultivars/lines, namely 03FJ26, NR 337, NR 339, NR 347, NR 350, Manthar, Margalla 99, Iqbal 2000, Saleem 2000, Wafaq 2001, Marwat 2001, Pirsabak 2004 and Fareed 2006 carry leaf rust and stripe rust resistance genes Lr34/Yr18. Stem rust resistance gene Sr2 was observed in 36 Pakistani spring wheat cultivars/lines using stm560.3tgag marker. The slow rusting gene Sr2 needs to be combined with additional stem rust resistance genes to establish durable resistance against Ug99 in modern wheat cultivars. Low frequency of Lr34/Yr18 was found in Pakistani wheats. This gene cluster needs to be incorporated into Pakistani wheats for durable rust resistance. (author)

  19. Efficacy of a hospital-wide environmental cleaning protocol on hospital-acquired methicillin-resistant Staphylococcus aureus rates.

    Science.gov (United States)

    Watson, Paul Andrew; Watson, Luke Robert; Torress-Cook, Alfonso

    2016-07-01

    Environmental contamination has been associated with over half of methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in hospitals. We explored if a hospital-wide environmental and patient cleaning protocol would lower hospital acquired MRSA rates and associated costs. This study evaluates the impact of implementing a hospital-wide environmental and patient cleaning protocol on the rate of MRSA infection and the potential cost benefit of the intervention. A retrospective, pre-post interventional study design was used. The intervention comprised a combination of enhanced environmental cleaning of high touch surfaces, daily washing of patients with benzalkonium chloride, and targeted isolation of patients with active infection. The rate of MRSA infection per 1000 patient days (PD) was compared with the rate after the intervention (Steiros Algorithm ® ) was implemented. A cost-benefit analysis based on the number of MRSA infections avoided was conducted. The MRSA rates decreased by 96% from 3.04 per 1000 PD to 0.11 per 1000 PD ( P reduction in MRSA infections, avoided an estimated $1,655,143 in healthcare costs. Implementation of this hospital-wide protocol appears to be associated with a reduction in the rate of MRSA infection and therefore a reduction in associated healthcare costs.

  20. Genome-wide meta-analysis identifies novel determinants of circulating serum progranulin.

    Science.gov (United States)

    Tönjes, Anke; Scholz, Markus; Krüger, Jacqueline; Krause, Kerstin; Schleinitz, Dorit; Kirsten, Holger; Gebhardt, Claudia; Marzi, Carola; Grallert, Harald; Ladenvall, Claes; Heyne, Henrike; Laurila, Esa; Kriebel, Jennifer; Meisinger, Christa; Rathmann, Wolfgang; Gieger, Christian; Groop, Leif; Prokopenko, Inga; Isomaa, Bo; Beutner, Frank; Kratzsch, Jürgen; Fischer-Rosinsky, Antje; Pfeiffer, Andreas; Krohn, Knut; Spranger, Joachim; Thiery, Joachim; Blüher, Matthias; Stumvoll, Michael; Kovacs, Peter

    2018-02-01

    Progranulin is a secreted protein with important functions in processes including immune and inflammatory response, metabolism and embryonic development. The present study aimed at identification of genetic factors determining progranulin concentrations. We conducted a genome-wide association meta-analysis for serum progranulin in three independent cohorts from Europe: Sorbs (N = 848) and KORA (N = 1628) from Germany and PPP-Botnia (N = 335) from Finland (total N = 2811). Single nucleotide polymorphisms (SNPs) associated with progranulin levels were replicated in two additional German cohorts: LIFE-Heart Study (Leipzig; N = 967) and Metabolic Syndrome Berlin Potsdam (Berlin cohort; N = 833). We measured mRNA expression of genes in peripheral blood mononuclear cells (PBMC) by micro-arrays and performed mRNA expression quantitative trait and expression-progranulin association studies to functionally substantiate identified loci. Finally, we conducted siRNA silencing experiments in vitro to validate potential candidate genes within the associated loci. Heritability of circulating progranulin levels was estimated at 31.8% and 26.1% in the Sorbs and LIFE-Heart cohort, respectively. SNPs at three loci reached study-wide significance (rs660240 in CELSR2-PSRC1-MYBPHL-SORT1, rs4747197 in CDH23-PSAP and rs5848 in GRN) explaining 19.4%/15.0% of the variance and 61%/57% of total heritability in the Sorbs/LIFE-Heart Study. The strongest evidence for association was at rs660240 (P = 5.75 × 10-50), which was also associated with mRNA expression of PSRC1 in PBMC (P = 1.51 × 10-21). Psrc1 knockdown in murine preadipocytes led to a consecutive 30% reduction in progranulin secretion. In conclusion, the present meta-GWAS combined with mRNA expression identified three loci associated with progranulin and supports the role of PSRC1 in the regulation of progranulin secretion. © The Author(s) 2017. Published by Oxford University Press. All rights

  1. Experimental determination of fuel-cladding thermal contact resistance

    International Nuclear Information System (INIS)

    Maglic, K.; Zivotic, Z.

    1968-01-01

    Thermal resistance of the UO 2 fuel - Zr-2 cladding was measure by the same experimental apparatus which was used for measuring the thermal conductivity of ceramic fuel. Thermal resistance was measure for a series of heat flux values and the dependence of thermal resistance on the flux is given within in the range from 0.66 W/cm 2 to 13.3 W/cm 2 . The temperature drop on the contact surface was between 39 deg C and 181.7 deg C, proportional to the increase of the heat flux [sr

  2. Resistance to glufosinate is proportional to phosphinothricin acetyltransferase expression and activity in LibertyLink(®) and WideStrike(®) cotton.

    Science.gov (United States)

    Carbonari, Caio A; Latorre, Débora O; Gomes, Giovanna L G C; Velini, Edivaldo D; Owens, Daniel K; Pan, Zhiqiang; Dayan, Franck E

    2016-04-01

    Insertion of the gene encoding phosphinothricin acetyltransferase (PAT) has resulted in cotton plants resistant to the herbicide glufosinate. However, the lower expression and commensurate reduction in PAT activity is a key factor in the low level of injury observed in the WideStrike(®) cotton and relatively high level of resistance observed in LibertyLink(®) cotton. LibertyLink(®) cotton cultivars are engineered for glufosinate resistance by overexpressing the bar gene that encodes phosphinothricin acetyltransferase (PAT), whereas the insect-resistant WideStrike(®) cultivars were obtained using the similar pat gene as a selectable marker. The latter cultivars carry some level of resistance to glufosinate which enticed certain farmers to select this herbicide for weed control with WideStrike(®) cotton. The potency of glufosinate on conventional FM 993, insect-resistant FM 975WS, and glufosinate-resistant IMACD 6001LL cotton cultivars was evaluated and contrasted to the relative levels of PAT expression and activity. Conventional cotton was sensitive to glufosinate. The single copy of the pat gene present in the insect-resistant cultivar resulted in very low RNA expression of the gene and undetectable PAT activity in in vitro assays. Nonetheless, the presence of this gene provided a good level of resistance to glufosinate in terms of visual injury and effect on photosynthetic electron transport. The injury is proportional to the amount of ammonia accumulation. The strong promoter associated with bar expression in the glufosinate-resistant cultivar led to high RNA expression levels and PAT activity which protected this cultivar from glufosinate injury. While the insect-resistant cultivar demonstrated a good level of resistance to glufosinate, its safety margin is lower than that of the glufosinate-resistant cultivar. Therefore, farmers should be extremely careful in using glufosinate on cultivars not expressly designed and commercialized as resistant to this

  3. Determination of the Resistance of Cone-Shaped Solid Electrodes

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Hendriksen, Peter Vang; Koch, Søren

    2017-01-01

    during processing can be avoided. Newman's formula for current constriction in the electrolyte is then used to deduce the active contact area based on the ohmic resistance of the cell, and from this the surface specific electro-catalytic activity. However, for electrode materials with low electrical......A cone-shaped electrode pressed into an electrolyte can with advantage be utilized to characterize the electro-catalytic properties of the electrode, because it is less dependent on the electrode microstructure than e.g. thin porous composite electrodes, and reactions with the electrolyte occurring...... conductivity (like Ce1-xPrxO2-δ), the resistance of the cell is significantly influenced by the ohmic resistance of the cone electrode, wherefore it must be included. In this work the ohmic resistance of a cone is modelled analytically based on simplified geometries. The two analytical models only differ...

  4. Molecular screening of antibiotic-resistant determinants among ...

    African Journals Online (AJOL)

    In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies ... ocomial opportunistic infections such as urinary tract .... Twelve (20%) of these MDR isolates were from children.

  5. Insertion sequence transposition determines imipenem resistance in Acinetobacter baumannii.

    Science.gov (United States)

    Kuo, Han-Yueh; Chang, Kai-Chih; Liu, Chih-Chin; Tang, Chuan Yi; Peng, Jhih-Hua; Lu, Chia-Wei; Tu, Chi-Chao; Liou, Ming-Li

    2014-10-01

    This study employed genomewide analysis to investigate potential resistance mechanisms in Acinetobacter baumannii following imipenem exposure. Imipenem-selected mutants were generated from the imipenem-susceptible strain ATCC 17978 by multistep selection resistance. Antibiotic susceptibilities were examined, and the selected mutants originated from the ATCC 17978 strain were confirmed by pulsed-field gel electrophoresis. The genomic sequence of a resistant mutant was analyzed using a next-generation sequencing platform, and genetic recombination was further confirmed by PCR. The result showed that phenotypic resistance was observed with carbapenem upon exposure to various concentrations of imipenem. Genomewide analysis showed that ISAba1 transposition was initiated by imipenem exposure at concentrations up to 0.5 mg/L. Transposition of ISAba1 upstream of blaOXA-95 was detected in all the selected mutants. The expression of blaOXA-95 was further analyzed by quantitative PCR, and the results demonstrated that a 200-fold increase in gene expression was required for resistance to imipenem. This study concluded that imipenem exposure at a concentration of 0.5 mg/L mediated the transposition of ISAba1 upstream of the blaOXA-95 gene and resulted in the overexpression of blaOXA-95 gene, which may play a major role in the resistance to imipenem in A. baumannii.

  6. Genome-wide identification of genetic determinants for the cytotoxicity of perifosine

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2008-09-01

    Full Text Available Abstract Perifosine belongs to the class of alkylphospholipid analogues, which act primarily at the cell membrane, thereby targeting signal transduction pathways. In phase I/II clinical trials, perifosine has induced tumour regression and caused disease stabilisation in a variety of tumour types. The genetic determinants responsible for its cytotoxicity have not been comprehensively studied, however. We performed a genome-wide analysis to identify genes whose expression levels or genotypic variation were correlated with the cytotoxicity of perifosine, using public databases on the US National Cancer Institute (NCI-60 human cancer cell lines. For demonstrating drug specificity, the NCI Standard Agent Database (including 171 drugs acting through a variety of mechanisms was used as a control. We identified agents with similar cytotoxicity profiles to that of perifosine in compounds used in the NCI drug screen. Furthermore, Gene Ontology and pathway analyses were carried out on genes more likely to be perifosine specific. The results suggested that genes correlated with perifosine cytotoxicity are connected by certain known pathways that lead to the mitogen-activated protein kinase signalling pathway and apoptosis. Biological processes such as 'response to stress', 'inflammatory response' and 'ubiquitin cycle' were enriched among these genes. Three single nucleotide polymorphisms (SNPs located in CACNA2DI and EXOC4 were found to be correlated with perifosine cytotoxicity. Our results provided a manageable list of genes whose expression levels or genotypic variation were strongly correlated with the cytotoxcity of perifosine. These genes could be targets for further studies using candidate-gene approaches. The results also provided insights into the pharmacodynamics of perifosine.

  7. Factors determining sensitivity or resistance of tumor cell lines towards artesunate.

    Science.gov (United States)

    Sertel, Serkan; Eichhorn, Tolga; Sieber, Sebastian; Sauer, Alexandra; Weiss, Johanna; Plinkert, Peter K; Efferth, Thomas

    2010-04-15

    Clinical oncology is still challenged by the development of drug resistance of tumors that result in poor prognosis for patients. There is an urgent necessity to understand the molecular mechanisms of resistance and to develop novel therapy strategies. Artesunate (ART) is an anti-malarial drug, which also exerts profound cytotoxic activity towards cancer cells. We first applied a gene-hunting approach using cluster and COMPARE analyses of microarray-based transcriptome-wide mRNA expression profiles. Among the genes identified by this approach were genes from diverse functional groups such as structural constituents of ribosomes (RPL6, RPL7, RPS12, RPS15A), kinases (CABC1, CCT2, RPL41), transcriptional and translational regulators (SFRS2, TUFM, ZBTB4), signal transducers (FLNA), control of cell growth and proliferation (RPS6), angiogenesis promoting factors (ITGB1), and others (SLC25A19, NCKAP1, BST1, DBH, FZD7, NACA, MTHFD2). Furthermore, we applied a candidate gene approach and tested the role of resistance mechanisms towards established anti-cancer drugs for ART resistance. By using transfected or knockout cell models we found that the tumor suppressor p16(INK4A) and the anti-oxidant protein, catalase, conferred resistance towards ART, while the oncogene HPV-E6 conferred sensitivity towards ART. The tumor suppressor p53 and its downstream protein, p21, as well as the anti-oxidant manganese-dependent superoxide dismutase did not affect cellular response to ART. In conclusion, our pharmacogenomic approach revealed that response of tumor cells towards ART is multi-factorial and is determined by gene expression associated with either ART sensitivity or resistance. At least some of the functional groups of genes (e.g. angiogenesis promoting factors, cell growth and proliferation-associated genes signal transducers and kinases) are also implicated in clinical responsiveness of tumors towards chemotherapy. It merits further investigation, whether ART is responsive in

  8. Determination of Flow Resistance Coefficient for Vegetation in Open Channel: Laboratory study

    Science.gov (United States)

    Aliza Ahmad, Noor; Ali, ZarinaMd; Arish, Nur Aini Mohd; Munirah Mat Daud, Azra; Fatin Amirah Alias, Nur

    2018-04-01

    This study focused on determination of flow resistances coefficient for grass in an open channel. Laboratory works were conducted to examine the effects of varying of roughness elements on the flume to determine flow resistance coefficient and also to determine the optimum flow resistance with five different flow rate, Q. Laboratory study with two type of vegetation which are Cow Grass and Pearl Grass were implementing to the bed of a flume. The roughness coefficient, n value is determine using Manning’s equation while Soil Conservation Services (SCS) method was used to determine the surface resistance. From the experiment, the flow resistance coefficient for Cow Grass in range 0.0008 - 0.0039 while Pearl Grass value for the flow resistance coefficient are in between 0.0013 - 0.0054. As a conclusion the vegetation roughness value in open channel are depends on density, distribution type of vegetation used and physical characteristic of the vegetation itself

  9. Genome-Wide Association Mapping of Fusarium Head Blight Resistance in Wheat using Genotyping-by-Sequencing

    Directory of Open Access Journals (Sweden)

    Marcio P. Arruda

    2016-03-01

    Full Text Available Fusarium head blight (FHB is one of the most important wheat ( L. diseases worldwide, and host resistance displays complex genetic control. A genome-wide association study (GWAS was performed on 273 winter wheat breeding lines from the midwestern and eastern regions of the United States to identify chromosomal regions associated with FHB resistance. Genotyping-by-sequencing (GBS was used to identify 19,992 single-nucleotide polymorphisms (SNPs covering all 21 wheat chromosomes. Marker–trait associations were performed with different statistical models, the most appropriate being a compressed mixed linear model (cMLM controlling for relatedness and population structure. Ten significant SNP–trait associations were detected on chromosomes 4A, 6A, 7A, 1D, 4D, and 7D, and multiple SNPs were associated with on chromosome 3B. Although combination of favorable alleles of these SNPs resulted in lower levels of severity (SEV, incidence (INC, and deoxynivalenol concentration (DON, lines carrying multiple beneficial alleles were in very low frequency for most traits. These SNPs can now be used for creating new breeding lines with different combinations of favorable alleles. This is one of the first GWAS using genomic resources from the International Wheat Genome Sequencing Consortium (IWGSC.

  10. Crack resistance curve determination of zircaloy-4 cladding

    International Nuclear Information System (INIS)

    Bertsch, J.; Alam, A.; Zubler, R.

    2009-03-01

    Fracture mechanics properties of fuel claddings are of relevance with respect to fuel rod integrity. The integrity of a fuel rod, in turn, is important for the fuel performance, for the safe handling of fuel rods, for the prevention of leakages and subsequent dissemination of fuel, for the avoidance of unnecessary dose rates, and for safe operation. Different factors can strongly deteriorate the mechanical fuel rod properties: irradiation damage, thermo-mechanical impact, corrosion or hydrogen uptake. To investigate the mechanical properties of fuel rod claddings which are used in Swiss nuclear power plants, PSI has initiated a program for mechanical testing. A major issue was the interaction between specific loading devices and the tested cladding tube, e.g. in the form of bending or friction. Particular for Zircaloy is the hexagonal closed packed structure of the zirconium crystallographic lattice. This structure implies plastic deformation mechanisms with specific, preferred orientations. Further, the manufacturing procedure of Zircaloy claddings induces a specific texture which plays a salient role with respect to the embrittlement by irradiation or integration of hydrogen in the form of hydrides. Both, the induced microstructure as well as the plastic deformation behaviour play a role for the mechanical properties. At PSI, in a first step inactive thin walled Zircaloy tubes and, for comparison reasons, plates were tested. The validity of the mechanical testing of the non standard tube and plate geometries had to be verified. The used Zircaloy-4 cladding tube sections and small plates of the same wall thickness have been notched, fatigue pre-cracked and tensile tested to evaluate the fracture toughness properties at room temperature, 300 o C and 350 o C. The crack propagation has been determined optically. The test results of the plates have been further used to validate FEM calculations. For each sample a complete crack resistance (J-R) curve could be

  11. Crack resistance curve determination of zircaloy-4 cladding

    Energy Technology Data Exchange (ETDEWEB)

    Bertsch, J.; Alam, A.; Zubler, R

    2009-03-15

    Fracture mechanics properties of fuel claddings are of relevance with respect to fuel rod integrity. The integrity of a fuel rod, in turn, is important for the fuel performance, for the safe handling of fuel rods, for the prevention of leakages and subsequent dissemination of fuel, for the avoidance of unnecessary dose rates, and for safe operation. Different factors can strongly deteriorate the mechanical fuel rod properties: irradiation damage, thermo-mechanical impact, corrosion or hydrogen uptake. To investigate the mechanical properties of fuel rod claddings which are used in Swiss nuclear power plants, PSI has initiated a program for mechanical testing. A major issue was the interaction between specific loading devices and the tested cladding tube, e.g. in the form of bending or friction. Particular for Zircaloy is the hexagonal closed packed structure of the zirconium crystallographic lattice. This structure implies plastic deformation mechanisms with specific, preferred orientations. Further, the manufacturing procedure of Zircaloy claddings induces a specific texture which plays a salient role with respect to the embrittlement by irradiation or integration of hydrogen in the form of hydrides. Both, the induced microstructure as well as the plastic deformation behaviour play a role for the mechanical properties. At PSI, in a first step inactive thin walled Zircaloy tubes and, for comparison reasons, plates were tested. The validity of the mechanical testing of the non standard tube and plate geometries had to be verified. The used Zircaloy-4 cladding tube sections and small plates of the same wall thickness have been notched, fatigue pre-cracked and tensile tested to evaluate the fracture toughness properties at room temperature, 300 {sup o}C and 350 {sup o}C. The crack propagation has been determined optically. The test results of the plates have been further used to validate FEM calculations. For each sample a complete crack resistance (J-R) curve could

  12. Environmental pollution by antibiotics and by antibiotic resistance determinants

    International Nuclear Information System (INIS)

    Martinez, Jose Luis

    2009-01-01

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  13. Environmental pollution by antibiotics and by antibiotic resistance determinants

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jose Luis, E-mail: jlmtnez@cnb.csic.e [Departamento de Biotecnologia Microbiana, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Darwin 3, Cantoblanco, 28049 Madrid, and CIBERESP (Spain)

    2009-11-15

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  14. Combinations of macrolide resistance determinants in field isolates of Mannheimia haemolytica and Pasteurella multocida

    DEFF Research Database (Denmark)

    Desmolaize, Benoit; Rose, Simon; Wilhelm, Cornelia

    2011-01-01

    of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. The first class has type I macrolide, lincosamide, and streptogramin B antibiotic resistance and, consistent with this, the 23S rRNA nucleotide A2058 is monomethylated by the enzyme product......(E) genes within an isogenic Escherichia coli background to assess their individually contributions to resistance. Our findings indicate what types of compounds might have driven the selection for these resistance determinants....

  15. Genome-Wide Distribution, Organisation and Functional Characterization of Disease Resistance and Defence Response Genes across Rice Species

    Science.gov (United States)

    Singh, Sangeeta; Chand, Suresh; Singh, N. K.; Sharma, Tilak Raj

    2015-01-01

    The resistance (R) genes and defense response (DR) genes have become very important resources for the development of disease resistant cultivars. In the present investigation, genome-wide identification, expression, phylogenetic and synteny analysis was done for R and DR-genes across three species of rice viz: Oryza sativa ssp indica cv 93-11, Oryza sativa ssp japonica and wild rice species, Oryza brachyantha. We used the in silico approach to identify and map 786 R -genes and 167 DR-genes, 672 R-genes and 142 DR-genes, 251 R-genes and 86 DR-genes in the japonica, indica and O. brachyanth a genomes, respectively. Our analysis showed that 60.5% and 55.6% of the R-genes are tandemly repeated within clusters and distributed over all the rice chromosomes in indica and japonica genomes, respectively. The phylogenetic analysis along with motif distribution shows high degree of conservation of R- and DR-genes in clusters. In silico expression analysis of R-genes and DR-genes showed more than 85% were expressed genes showing corresponding EST matches in the databases. This study gave special emphasis on mechanisms of gene evolution and duplication for R and DR genes across species. Analysis of paralogs across rice species indicated 17% and 4.38% R-genes, 29% and 11.63% DR-genes duplication in indica and Oryza brachyantha, as compared to 20% and 26% duplication of R-genes and DR-genes in japonica respectively. We found that during the course of duplication only 9.5% of R- and DR-genes changed their function and rest of the genes have maintained their identity. Syntenic relationship across three genomes inferred that more orthology is shared between indica and japonica genomes as compared to brachyantha genome. Genome wide identification of R-genes and DR-genes in the rice genome will help in allele mining and functional validation of these genes, and to understand molecular mechanism of disease resistance and their evolution in rice and related species. PMID:25902056

  16. Determination of the Antibiotic Resistance Profile of Student Cell Phones

    Directory of Open Access Journals (Sweden)

    Lisa Ann Blankinship

    2012-08-01

    Full Text Available Sampling of common use items (e.g., student cell phones for bacterial presence, identification, and antibiotic resistance profiling helps students to recognize the need for routine cleaning of personal items and encourages thoughtful use of currently available medications. This multilab period project can be used to teach or reinforce several methods from general microbiology including aseptic technique, isolation streak, serial dilution, spread plating, Kirby Bauer testing, unknown identification, and media production. The data generated can be saved and added to each semester, thus providing a data set that reflects a local trend of antibiotic resistance.      

  17. Saturation mapping of QTL region determining resistance specificity ...

    African Journals Online (AJOL)

    Genetic improvement for biotic resistance in rice involves the quantitative nature of inheritance, which reflects the additive effects of several genetic loci throughout the genome. To in silico identify putative candidate genes involved in defense response, we performed in silico anchoring of the QTL genetic marker data to the ...

  18. Two distinct classes of QTL determine rust resistance in sorghum.

    Science.gov (United States)

    Wang, Xuemin; Mace, Emma; Hunt, Colleen; Cruickshank, Alan; Henzell, Robert; Parkes, Heidi; Jordan, David

    2014-12-31

    Agriculture is facing enormous challenges to feed a growing population in the face of rapidly evolving pests and pathogens. The rusts, in particular, are a major pathogen of cereal crops with the potential to cause large reductions in yield. Improving stable disease resistance is an on-going major and challenging focus for many plant breeding programs, due to the rapidly evolving nature of the pathogen. Sorghum is a major summer cereal crop that is also a host for a rust pathogen Puccinia purpurea, which occurs in almost all sorghum growing areas of the world, causing direct and indirect yield losses in sorghum worldwide, however knowledge about its genetic control is still limited. In order to further investigate this issue, QTL and association mapping methods were implemented to study rust resistance in three bi-parental populations and an association mapping set of elite breeding lines in different environments. In total, 64 significant or highly significant QTL and 21 suggestive rust resistance QTL were identified representing 55 unique genomic regions. Comparisons across populations within the current study and with rust QTL identified previously in both sorghum and maize revealed a high degree of correspondence in QTL location. Negative phenotypic correlations were observed between rust, maturity and height, indicating a trend for both early maturing and shorter genotypes to be more susceptible to rust. The significant amount of QTL co-location across traits, in addition to the consistency in the direction of QTL allele effects, has provided evidence to support pleiotropic QTL action across rust, height, maturity and stay-green, supporting the role of carbon stress in susceptibility to rust. Classical rust resistance QTL regions that did not co-locate with height, maturity or stay-green QTL were found to be significantly enriched for the defence-related NBS-encoding gene family, in contrast to the lack of defence-related gene enrichment in multi-trait effect

  19. 30 CFR 27.41 - Test to determine resistance to moisture.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test to determine resistance to moisture. 27.41... determine resistance to moisture. Components, subassemblies, or assemblies, the normal functioning of which might be affected by moisture, shall be tested in atmospheres of high relative humidity (80 percent or...

  20. Identification of New Resistance Loci to African Stem Rust Race TTKSK in Tetraploid Wheats Based on Linkage and Genome-Wide Association Mapping.

    Science.gov (United States)

    Laidò, Giovanni; Panio, Giosuè; Marone, Daniela; Russo, Maria A; Ficco, Donatella B M; Giovanniello, Valentina; Cattivelli, Luigi; Steffenson, Brian; de Vita, Pasquale; Mastrangelo, Anna M

    2015-01-01

    Stem rust, caused by Puccinia graminis Pers. f. sp. tritici Eriks. and E. Henn. (Pgt), is one of the most destructive diseases of wheat. Races of the pathogen in the "Ug99 lineage" are of international concern due to their virulence for widely used stem rust resistance genes and their spread throughout Africa. Disease resistant cultivars provide one of the best means for controlling stem rust. To identify quantitative trait loci (QTL) conferring resistance to African stem rust race TTKSK at the seedling stage, we evaluated an association mapping (AM) panel consisting of 230 tetraploid wheat accessions under greenhouse conditions. A high level of phenotypic variation was observed in response to race TTKSK in the AM panel, allowing for genome-wide association mapping of resistance QTL in wild, landrace, and cultivated tetraploid wheats. Thirty-five resistance QTL were identified on all chromosomes, and seventeen are of particular interest as identified by multiple associations. Many of the identified resistance loci were coincident with previously identified rust resistance genes; however, nine on chromosomes 1AL, 2AL, 4AL, 5BL, and 7BS may be novel. To validate AM results, a biparental population of 146 recombinant inbred lines was also considered, which derived from a cross between the resistant cultivar "Cirillo" and susceptible "Neodur." The stem rust resistance of Cirillo was conferred by a single gene on the distal region of chromosome arm 6AL in an interval map coincident with the resistance gene Sr13, and confirmed one of the resistance loci identified by AM. A search for candidate resistance genes was carried out in the regions where QTL were identified, and many of them corresponded to NBS-LRR genes and protein kinases with LRR domains. The results obtained in the present study are of great interest as a high level of genetic variability for resistance to race TTKSK was described in a germplasm panel comprising most of the tetraploid wheat sub-species.

  1. Determination of the electrical resistivity of vertically aligned carbon nanotubes by scanning probe microscopy

    Science.gov (United States)

    Ageev, O. A.; Il'in, O. I.; Rubashkina, M. V.; Smirnov, V. A.; Fedotov, A. A.; Tsukanova, O. G.

    2015-07-01

    Techniques are developed to determine the resistance per unit length and the electrical resistivity of vertically aligned carbon nanotubes (VA CNTs) using atomic force microscopy (AFM) and scanning tunneling microscopy (STM). These techniques are used to study the resistance of VA CNTs. The resistance of an individual VA CNT calculated with the AFM-based technique is shown to be higher than the resistance of VA CNTs determined by the STM-based technique by a factor of 200, which is related to the influence of the resistance of the contact of an AFM probe to VA CNTs. The resistance per unit length and the electrical resistivity of an individual VA CNT 118 ± 39 nm in diameter and 2.23 ± 0.37 μm in height that are determined by the STM-based technique are 19.28 ± 3.08 kΩ/μm and 8.32 ± 3.18 × 10-4 Ω m, respectively. The STM-based technique developed to determine the resistance per unit length and the electrical resistivity of VA CNTs can be used to diagnose the electrical parameters of VA CNTs and to create VA CNT-based nanoelectronic elements.

  2. Resistance to hepatitis C virus: potential genetic and immunological determinants.

    Science.gov (United States)

    Mina, Michael M; Luciani, Fabio; Cameron, Barbara; Bull, Rowena A; Beard, Michael R; Booth, David; Lloyd, Andrew R

    2015-04-01

    Studies of individuals who were highly exposed but seronegative (HESN) for HIV infection led to the discovery that homozygosity for the Δ32 deletion mutation in the CCR5 gene prevents viral entry into target cells, and is associated with resistance to infection. Additionally, evidence for protective immunity has been noted in some HESN groups, such as sex workers in The Gambia. Population studies of individuals at high risk for hepatitis C virus infection suggest that an HESN phenotype exists. The body of evidence, which suggests that protective immunity allows clearance of hepatitis C virus without seroconversion is growing. Furthermore, proof-of-principle evidence from in-vitro studies shows that genetic polymorphisms can confer resistance to establishment of infection. This Review discusses the possibility that genetic mutations confer resistance against hepatitis C virus, and also explores evidence for protective immunity, including via genetically programmed variations in host responses. The data generally strengthens the notion that investigations of naturally arising polymorphisms within the hepatitis C virus interactome, and genetic association studies of well characterised HESN individuals, could identify potential targets for vaccine design and inform novel therapies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Rapid determination of antibiotic resistance in E. coli using dielectrophoresis

    International Nuclear Information System (INIS)

    Hoettges, Kai F; Dale, Jeremy W; Hughes, Michael P

    2007-01-01

    In recent years, infections due to antibiotic-resistant strains of bacteria such as methillicin-resistant Staphylococcus aureus and ciprofloxacin-resistant Escherichia coli are on the rise, and with them the demand for rapid antibiotic testing is also rising. Conventional tests, such as disc diffusion testing, require a primary sample to be tested in the presence of a number of antibiotics to verify which antibiotics suppress growth, which take approximately 24 h to complete and potentially place the patient at severe risk. In this paper we describe the use of dielectrophoresis as a rapid marker of cell death, by detecting changes in the electrophysiology of the cell caused by the administration of an antibiotic. In contrast to other markers, the electrophysiology of the cell changes rapidly during cell death allowing live cells to be distinguished from dead (or dying) cells without the need for culturing. Using polymyxin B as an example antibiotic, our studies indicate that significant changes in cell characteristics can be observed as soon as 1 h passes after isolating a culture from nutrient broth

  4. Autosomal male determination in a spinosad-resistant housefly strain from Denmark

    DEFF Research Database (Denmark)

    Højland, Dorte H; Scott, Jeffrey G; Vagn Jensen, Karl-Martin

    2014-01-01

    males in this strain. The factor responsible for spinosad resistance in the strain is unknown, but previous studies suggest a role of cytochrome P450s for detoxification of spinosad. Sex determination in the housefly is controlled by a male-determining factor (M), either located on the Y chromosome......BACKGROUND The housefly, Musca domestica L., is a global pest and has developed resistance to most insecticides applied for its control. The insecticide spinosad plays an important role in housefly control. Females of the Danish housefly strain 791spin are threefold more resistant to spinosad than...... of resistance to spinosad. Sex determination in 791spin is due to a male factor on autosome 3. CONCLUSIONS The most likely explanation for the differentiation of spinosad resistance between males and females is a recessive spinosad resistance factor on autosome III. © 2013 Society of Chemical Industry...

  5. Genome-Wide Scan and Test of Candidate Genes in the Snail Biomphalaria glabrata Reveal New Locus Influencing Resistance to Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Jacob A Tennessen

    Full Text Available New strategies to combat the global scourge of schistosomiasis may be revealed by increased understanding of the mechanisms by which the obligate snail host can resist the schistosome parasite. However, few molecular markers linked to resistance have been identified and characterized in snails.Here we test six independent genetic loci for their influence on resistance to Schistosoma mansoni strain PR1 in the 13-16-R1 strain of the snail Biomphalaria glabrata. We first identify a genomic region, RADres, showing the highest differentiation between susceptible and resistant inbred lines among 1611 informative restriction-site associated DNA (RAD markers, and show that it significantly influences resistance in an independent set of 439 outbred snails. The additive effect of each RADres resistance allele is 2-fold, similar to that of the previously identified resistance gene sod1. The data fit a model in which both loci contribute independently and additively to resistance, such that the odds of infection in homozygotes for the resistance alleles at both loci (13% infected is 16-fold lower than the odds of infection in snails without any resistance alleles (70% infected. Genome-wide linkage disequilibrium is high, with both sod1 and RADres residing on haplotype blocks >2 Mb, and with other markers in each block also showing significant effects on resistance; thus the causal genes within these blocks remain to be demonstrated. Other candidate loci had no effect on resistance, including the Guadeloupe Resistance Complex and three genes (aif, infPhox, and prx1 with immunological roles and expression patterns tied to resistance, which must therefore be trans-regulated.The loci RADres and sod1 both have strong effects on resistance to S. mansoni. Future approaches to control schistosomiasis may benefit from further efforts to characterize and harness this natural genetic variation.

  6. Diversity of Antimicrobial Resistance and Virulence Determinants in Pseudomonas aeruginosa Associated with Fresh Vegetables

    Directory of Open Access Journals (Sweden)

    Kashina Allydice-Francis

    2012-01-01

    Full Text Available With the increased focus on healthy eating and consuming raw vegetables, this study assessed the extent of contamination of fresh vegetables by Pseudomonas aeruginosa in Jamaica and examined the antibiotic susceptibility profiles and the presence of various virulence associated determinants of P. aeruginosa. Analyses indicated that vegetables from retail markets and supermarkets were widely contaminated by P. aeruginosa; produce from markets were more frequently contaminated, but the difference was not significant. Lettuce and carrots were the most frequently contaminated vegetables, while tomatoes were the least. Pigment production (Pyoverdine, pyocyanin, pyomelanin and pyorubin, fluorescein and alginate were common in these isolates. Imipenem, gentamicin and ciprofloxacin were the most inhibitory antimicrobial agents. However, isolates were resistant or showed reduced susceptibility to ampicillin, chloramphenicol, sulphamethoxazole/trimethoprim and aztreonam, and up to 35% of the isolates were resistant to four antimicrobial agents. As many as 30% of the isolates were positive for the fpv1 gene, and 13% had multiple genes. Sixty-four percent of the isolates harboured an exoenzyme gene (exoS, exoT, exoU or exoY, and multiple exo genes were common. We conclude that P. aeruginosa is a major contaminant of fresh vegetables, which might be a source of infection for susceptible persons within the community.

  7. Determination of internal series resistance of PV devices: repeatability and uncertainty

    International Nuclear Information System (INIS)

    Trentadue, Germana; Pavanello, Diego; Salis, Elena; Field, Mike; Müllejans, Harald

    2016-01-01

    The calibration of photovoltaic devices requires the measurement of their current–voltage characteristics at standard test conditions (STC). As the latter can only be reached approximately, a curve translation is necessary, requiring among others the internal series resistance of the photovoltaic device as an input parameter. Therefore accurate and reliable determination of the series resistance is important in measurement and test laboratories. This work follows standard IEC 60891 ed 2 (2009) for the determination of the internal series resistance and investigates repeatability and uncertainty of the result in three aspects for a number of typical photovoltaic technologies. Firstly the effect of varying device temperature on the determined series resistance is determined experimentally and compared to a theoretical derivation showing agreement. It is found that the series resistance can be determined with an uncertainty of better than 5% if the device temperature is stable within  ±0.1 °C, whereas the temperature range of  ±2 °C allowed by the standard leads to much larger variations. Secondly the repeatability of the series resistance determination with respect to noise in current–voltage measurement is examined yielding typical values of  ±5%. Thirdly the determination of the series resistance using three different experimental set-ups (solar simulators) shows agreement on the level of  ±5% for crystalline Silicon photovoltaic devices and deviations up to 15% for thin-film devices. It is concluded that the internal series resistance of photovoltaic devices could be determined with an uncertainty of better than 10%. The influence of this uncertainty in series resistance on the electrical performance parameters of photovoltaic devices was estimated and showed a contribution of 0.05% for open-circuit voltage and 0.1% for maximum power. Furthermore it is concluded that the range of device temperatures allowed during determination of series

  8. Genome Wide Association Study for Drought, Aflatoxin Resistance, and Important Agronomic Traits of Maize Hybrids in the Sub-Tropics

    Science.gov (United States)

    Farfan, Ivan D. Barrero; De La Fuente, Gerald N.; Murray, Seth C.; Isakeit, Thomas; Huang, Pei-Cheng; Warburton, Marilyn; Williams, Paul; Windham, Gary L.; Kolomiets, Mike

    2015-01-01

    The primary maize (Zea mays L.) production areas are in temperate regions throughout the world and this is where most maize breeding is focused. Important but lower yielding maize growing regions such as the sub-tropics experience unique challenges, the greatest of which are drought stress and aflatoxin contamination. Here we used a diversity panel consisting of 346 maize inbred lines originating in temperate, sub-tropical and tropical areas testcrossed to stiff-stalk line Tx714 to investigate these traits. Testcross hybrids were evaluated under irrigated and non-irrigated trials for yield, plant height, ear height, days to anthesis, days to silking and other agronomic traits. Irrigated trials were also inoculated with Aspergillus flavus and evaluated for aflatoxin content. Diverse maize testcrosses out-yielded commercial checks in most trials, which indicated the potential for genetic diversity to improve sub-tropical breeding programs. To identify genomic regions associated with yield, aflatoxin resistance and other important agronomic traits, a genome wide association analysis was performed. Using 60,000 SNPs, this study found 10 quantitative trait variants for grain yield, plant and ear height, and flowering time after stringent multiple test corrections, and after fitting different models. Three of these variants explained 5–10% of the variation in grain yield under both water conditions. Multiple identified SNPs co-localized with previously reported QTL, which narrows the possible location of causal polymorphisms. Novel significant SNPs were also identified. This study demonstrated the potential to use genome wide association studies to identify major variants of quantitative and complex traits such as yield under drought that are still segregating between elite inbred lines. PMID:25714370

  9. Genome-wide scan of gastrointestinal nematode resistance in closed Angus population selected for minimized influence of MHC.

    Science.gov (United States)

    Kim, Eui-Soo; Sonstegard, Tad S; da Silva, Marcos V G B; Gasbarre, Louis C; Van Tassell, Curtis P

    2015-01-01

    Genetic markers associated with parasite indicator traits are ideal targets for study of marker assisted selection aimed at controlling infections that reduce herd use of anthelminthics. For this study, we collected gastrointestinal (GI) nematode fecal egg count (FEC) data from post-weaning animals of an Angus resource population challenged to a 26 week natural exposure on pasture. In all, data from 487 animals was collected over a 16 year period between 1992 and 2007, most of which were selected for a specific DRB1 allele to reduce the influence of potential allelic variant effects of the MHC locus. A genome-wide association study (GWAS) based on BovineSNP50 genotypes revealed six genomic regions located on bovine Chromosomes 3, 5, 8, 15 and 27; which were significantly associated (-log10 p=4.3) with Box-Cox transformed mean FEC (BC-MFEC). DAVID analysis of the genes within the significant genomic regions suggested a correlation between our results and annotation for genes involved in inflammatory response to infection. Furthermore, ROH and selection signature analyses provided strong evidence that the genomic regions associated BC-MFEC have not been affected by local autozygosity or recent experimental selection. These findings provide useful information for parasite resistance prediction for young grazing cattle and suggest new candidate gene targets for development of disease-modifying therapies or future studies of host response to GI parasite infection.

  10. Genome-wide scan of gastrointestinal nematode resistance in closed Angus population selected for minimized influence of MHC.

    Directory of Open Access Journals (Sweden)

    Eui-Soo Kim

    Full Text Available Genetic markers associated with parasite indicator traits are ideal targets for study of marker assisted selection aimed at controlling infections that reduce herd use of anthelminthics. For this study, we collected gastrointestinal (GI nematode fecal egg count (FEC data from post-weaning animals of an Angus resource population challenged to a 26 week natural exposure on pasture. In all, data from 487 animals was collected over a 16 year period between 1992 and 2007, most of which were selected for a specific DRB1 allele to reduce the influence of potential allelic variant effects of the MHC locus. A genome-wide association study (GWAS based on BovineSNP50 genotypes revealed six genomic regions located on bovine Chromosomes 3, 5, 8, 15 and 27; which were significantly associated (-log10 p=4.3 with Box-Cox transformed mean FEC (BC-MFEC. DAVID analysis of the genes within the significant genomic regions suggested a correlation between our results and annotation for genes involved in inflammatory response to infection. Furthermore, ROH and selection signature analyses provided strong evidence that the genomic regions associated BC-MFEC have not been affected by local autozygosity or recent experimental selection. These findings provide useful information for parasite resistance prediction for young grazing cattle and suggest new candidate gene targets for development of disease-modifying therapies or future studies of host response to GI parasite infection.

  11. Linezolid-resistant enterococci in Polish hospitals: species, clonality and determinants of linezolid resistance.

    Science.gov (United States)

    Gawryszewska, I; Żabicka, D; Hryniewicz, W; Sadowy, E

    2017-07-01

    The significant increase of the linezolid-resistant enterococci (LRE) has been observed in Polish hospitals since 2012 and our study aimed at elucidating the possible reasons for this phenomenon. Polish LRE isolates were analysed by multilocus-sequence typing (MLST) and multiple locus variable-number tandem repeat (VNTR) analysis (MLVA), polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (PCR-RFLP) to establish clonal relatedness and mechanism of linezolid resistance, respectively. Fifty analysed LRE (2008-2015) included mostly Enterococcus faecium (82%) and Enterococcus faecalis (16%). Enterococcus faecium belonged to the hospital-adapted lineages 17/18 and 78, while E. faecalis isolates represented ST6, a hospital-associated type, and ST116, found in both humans and food-production animals. The G2576T 23S rRNA mutation was the most frequent (94%) mechanism of linezolid/tedizolid resistance of LRE. None of the isolates carried the plasmid-associated gene of Cfr methyltransferase, whereas optrA, encoding the ABC-type drug transporter, was identified in two E. faecalis isolates. In these isolates, optrA was located on a plasmid, transferable to both E. faecium and E. faecalis, whose partial (36.3 kb) sequence was 100% identical to the pE394 plasmid, identified previously in China in both clinical and farm animal isolates. The optrA-E. faecium transconjugant displayed a significant growth deficiency, in contrast to the optrA-E. faecalis. Our study indicates the role of mutation acquisition by hospital-adapted clones of enterococci as a major driver of increasing resistance to linezolid and tedizolid. Transferability and apparent lack of a biological cost of resistance suggest that E. faecalis may be a natural reservoir of optrA, an emerging mechanism of oxazolidinone resistance.

  12. Genetic determinants of cardiovascular events among women with migraine: a genome-wide association study.

    Directory of Open Access Journals (Sweden)

    Markus Schürks

    Full Text Available Migraine is associated with an increased risk for cardiovascular disease (CVD. Both migraine and CVD are highly heritable. However, the genetic liability for CVD among migraineurs is unclear.We performed a genome-wide association study for incident CVD events during 12 years of follow-up among 5,122 migraineurs participating in the population-based Women's Genome Health Study. Migraine was self-reported and CVD events were confirmed after medical records review. We calculated odds ratios (OR and 95% confidence intervals (CI and considered a genome-wide p-value <5×10(-8 as significant.Among the 5,122 women with migraine 164 incident CVD events occurred during follow-up. No SNP was associated with major CVD, ischemic stroke, myocardial infarction, or CVD death at the genome-wide level; however, five SNPs showed association with p<5×10(-6. Among migraineurs with aura rs7698623 in MEPE (OR = 6.37; 95% CI 3.15-12.90; p = 2.7×10(-7 and rs4975709 in IRX4 (OR = 5.06; 95% CI 2.66-9.62; p = 7.7×10(-7 appeared to be associated with ischemic stroke, rs2143678 located close to MDF1 with major CVD (OR = 3.05; 95% CI 1.98-4.69; p = 4.3×10(-7, and the intergenic rs1406961 with CVD death (OR = 12.33; 95% CI 4.62-32.87; p = 5.2×10(-7. Further, rs1047964 in BACE1 appeared to be associated with CVD death among women with any migraine (OR = 4.67; 95% CI 2.53-8.62; p = 8.0×10(-7.Our results provide some suggestion for an association of five SNPs with CVD events among women with migraine; none of the results was genome-wide significant. Four associations appeared among migraineurs with aura, two of those with ischemic stroke. Although our population is among the largest with migraine and incident CVD information, these results must be treated with caution, given the limited number of CVD events among women with migraine and the low minor allele frequencies for three of the SNPs. Our results await independent replication

  13. Prevalence of genetic determinants and phenotypic resistance to ciprofloxacin in Campylobacter jejuni from lithuania

    DEFF Research Database (Denmark)

    Aksomaitiene, Jurgita; Ramonaite, Sigita; Olsen, John E.

    2018-01-01

    Recently, the number of reports on isolation of ciprofloxacin resistant Campylobacter jejuni has increased worldwide. The aim of this study was to determine the prevalence of resistance to ciprofloxacin and its genetic determinants among C. jejuni isolated from humans (n = 100), poultry products (n...... = 96) and wild birds (n = 96) in Lithuania. 91.4% of the C. jejuni isolates were phenotypically resistant to ciprofloxacin. DNA sequence analyses of the gyrA gene from 292 isolates revealed that a change in amino acid sequence, Thr86Ile, was the main substition conferring resistance to ciprofloxacin...... forty-five C. jejuni isolates showed one or more silent mutations, and 32.4% of examined isolates possessed six silent mutations. In addition to the ciprofloxacin resistant isolates harboring only Thr86Ile point mutation (110 isolates), the current study identified resistant isolates (n = 101) harboring...

  14. Molecular Determinants of Radio Resistance in Prostate Cancer

    National Research Council Canada - National Science Library

    Bristow, Robert

    2003-01-01

    ... (given in vivo tumor cell populations). An in vivo program of prostate xenograft radioresponse and patient biopsy studies will determine the level of DNA repair in situ using immunohistochemistry and immunoflorescent markers...

  15. System-wide organization of actin cytoskeleton determines organelle transport in hypocotyl plant cells

    Science.gov (United States)

    Nowak, Jacqueline; Ivakov, Alexander; Somssich, Marc; Persson, Staffan; Nikoloski, Zoran

    2017-01-01

    The actin cytoskeleton is an essential intracellular filamentous structure that underpins cellular transport and cytoplasmic streaming in plant cells. However, the system-level properties of actin-based cellular trafficking remain tenuous, largely due to the inability to quantify key features of the actin cytoskeleton. Here, we developed an automated image-based, network-driven framework to accurately segment and quantify actin cytoskeletal structures and Golgi transport. We show that the actin cytoskeleton in both growing and elongated hypocotyl cells has structural properties facilitating efficient transport. Our findings suggest that the erratic movement of Golgi is a stable cellular phenomenon that might optimize distribution efficiency of cell material. Moreover, we demonstrate that Golgi transport in hypocotyl cells can be accurately predicted from the actin network topology alone. Thus, our framework provides quantitative evidence for system-wide coordination of cellular transport in plant cells and can be readily applied to investigate cytoskeletal organization and transport in other organisms. PMID:28655850

  16. A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis

    Directory of Open Access Journals (Sweden)

    Moy Richard L

    2008-07-01

    Full Text Available Abstract Background Yersinia pestis is the causative agent of plague and a potential agent of bioterrorism and biowarfare. The plague biothreat and the emergence of multidrug-resistant plague underscore the need to increase our understanding of the intrinsic potential of Y. pestis for developing antimicrobial resistance and to anticipate the mechanisms of resistance that may emerge in Y. pestis. Identification of Y. pestis genes that, when overexpressed, are capable of reducing antibiotic susceptibility is a useful strategy to expose genes that this pathogen may rely upon to evolve antibiotic resistance via a vertical modality. In this study, we explored the use of a multicopy suppressor, Escherichia coli host-based screening approach as a means to expose antibiotic resistance determinant candidates in Y. pestis. Results We constructed a multicopy plasmid-based, Y. pestis genome-wide expression library of nearly 16,000 clones in E. coli and screened the library for suppressors of the antimicrobial activity of ofloxacin, a fluoroquinolone antibiotic. The screen permitted the identification of a transcriptional regulator-encoding gene (robAYp that increased the MIC99 of ofloxacin by 23-fold when overexpressed from a multicopy plasmid in Y. pestis. Additionally, we found that robAYp overexpression in Y. pestis conferred low-level resistance to many other antibiotics and increased organic solvent tolerance. Overexpression of robAYp also upregulated the expression of several efflux pumps in Y. pestis. Conclusion Our study provides proof of principle for the use of multicopy suppressor screening based on the tractable and easy-to-manipulate E. coli host as a means to identify antibiotic resistance determinant candidates of Y. pestis.

  17. A novel fusidic acid resistance determinant, fusF, in Staphylococcus cohnii.

    Science.gov (United States)

    Chen, Hsiao-Jan; Hung, Wei-Chun; Lin, Yu-Tzu; Tsai, Jui-Chang; Chiu, Hao-Chieh; Hsueh, Po-Ren; Teng, Lee-Jene

    2015-02-01

    To determine MICs of fusidic acid for and identify genetic determinants of resistance in Staphylococcus cohnii isolates. Susceptibility to fusidic acid was determined by the standard agar dilution method in 24 S. cohnii subsp. urealyticus clinical isolates, 7 S. cohnii subsp. cohnii clinical isolates and 2 reference strains. Sequencing of a novel resistance determinant, fusF, and its flanking regions was performed by long and accurate PCR and inverse PCR. To evaluate the function of fusF, the MIC of fusidic acid was determined for recombinant Staphylococcus aureus carrying a plasmid expressing fusF. A total of 25 S. cohnii subsp. urealyticus (24 clinical isolates and 1 reference strain) and 2 S. cohnii subsp. cohnii displayed low-level resistance to fusidic acid (MICs 2-16 mg/L). Sequencing of a 4259 bp fragment from S. cohnii subsp. urealyticus ATCC 49330 revealed a novel resistance gene, designated fusF, which displayed 70.5% nucleotide and 67.3% amino acid identity to fusD. Expression of fusF in S. aureus confers resistance to fusidic acid. A novel FusB-family gene, fusF, was identified as a major resistance determinant in S. cohnii clinical isolates resistant to fusidic acid. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. A community-wide intercomparison exercise for the determination of dissolved iron in seawater

    NARCIS (Netherlands)

    Bowie, A.R.; Achterberg, E.P.; Croot, P.l.; de Baar, H.J.W.; Laan, P.; Moffett, J.W; Ussher, S.; Worsfold, P.J.

    2006-01-01

    The first large-scale international intercomparison of analytical methods for the determination of dissolved iron in seawater was carried out between October 2000 and December 2002. The exercise was conducted as a rigorously "blind" comparison of 7 analytical techniques by 24 international

  19. Determinants of Severity in Acute Pancreatitis: A Nation-wide Multicenter Prospective Cohort Study.

    Science.gov (United States)

    Sternby, Hanna; Bolado, Federico; Canaval-Zuleta, Héctor J; Marra-López, Carlos; Hernando-Alonso, Ana I; Del-Val-Antoñana, Adolfo; García-Rayado, Guillermo; Rivera-Irigoin, Robin; Grau-García, Francisco J; Oms, Lluís; Millastre-Bocos, Judith; Pascual-Moreno, Isabel; Martínez-Ares, David; Rodríguez-Oballe, Juan A; López-Serrano, Antonio; Ruiz-Rebollo, María L; Viejo-Almanzor, Alejandro; González-de-la-Higuera, Belén; Orive-Calzada, Aitor; Gómez-Anta, Ignacio; Pamies-Guilabert, José; Fernández-Gutiérrez-Del-Álamo, Fátima; Iranzo-González-Cruz, Isabel; Pérez-Muñante, Mónica E; Esteba, María D; Pardillos-Tomé, Ana; Zapater, Pedro; de-Madaria, Enrique

    2018-04-18

    The aim of this study was to compare and validate the different classifications of severity in acute pancreatitis (AP) and to investigate which characteristics of the disease are associated with worse outcomes. AP is a heterogeneous disease, ranging from uneventful cases to patients with considerable morbidity and high mortality rates. Severity classifications based on legitimate determinants of severity are important to correctly describe the course of disease. A prospective multicenter cohort study involving patients with AP from 23 hospitals in Spain. The Atlanta Classification (AC), Revised Atlanta Classification (RAC), and Determinant-based Classification (DBC) were compared. Binary logistic multivariate analysis was performed to investigate independent determinants of severity. A total of 1655 patients were included; 70 patients (4.2%) died. RAC and DBC were equally superior to AC for describing the clinical course of AP. Although any kind of organ failure was associated with increased morbidity and mortality, persistent organ failure (POF) was the most significant determinant of severity. All local complications were associated with worse outcomes. Infected pancreatic necrosis correlated with high morbidity, but in the presence of POF, it was not associated to higher mortality when compared with sterile necrotizing pancreatitis. Exacerbation of previous comorbidity was associated with increased morbidity and mortality. The RAC and DBC both signify an advance in the description and differentiation of AP patients. Herein, we describe the complications of the disease independently associated to morbidity and mortality. Our findings are valuable not only when designing future studies on AP but also for the improvement of current classifications.

  20. Determination of resist parameters using the extended Nijboer-Zernike theory

    NARCIS (Netherlands)

    Dirksen, P.; Braat, J.; Janssen, A.J.E.M.; Leeuwestein, A.; Kwinten, H.; Van Steenwinckel, D.

    2004-01-01

    This study presents an experimental method to determine the resist parameters that are at the origin of a general blurring of the projected aerial image. The resist model includes the effects of diffusion in the horizontal plane and a second cause for image blur that originates from a stochastic

  1. On the difference between optically and electrically determined resistivity of ultra-thin titanium nitride films

    NARCIS (Netherlands)

    Van Hao, B.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

    2013-01-01

    This work reports on the determination and comparison of the resistivity of ultra-thin atomic layer deposited titanium nitride films in the thickness range 0.65–20 nm using spectroscopic ellipsometry and electrical test structures. We found that for films thicker than 4 nm, the resistivity values

  2. Characterization of molecular diversity and genome-wide mapping of loci associated with resistance to stripe rust and stem rust in Ethiopian bread wheat accessions.

    Science.gov (United States)

    Muleta, Kebede T; Rouse, Matthew N; Rynearson, Sheri; Chen, Xianming; Buta, Bedada G; Pumphrey, Michael O

    2017-08-04

    The narrow genetic basis of resistance in modern wheat cultivars and the strong selection response of pathogen populations have been responsible for periodic and devastating epidemics of the wheat rust diseases. Characterizing new sources of resistance and incorporating multiple genes into elite cultivars is the most widely accepted current mechanism to achieve durable varietal performance against changes in pathogen virulence. Here, we report a high-density molecular characterization and genome-wide association study (GWAS) of stripe rust and stem rust resistance in 190 Ethiopian bread wheat lines based on phenotypic data from multi-environment field trials and seedling resistance screening experiments. A total of 24,281 single nucleotide polymorphism (SNP) markers filtered from the wheat 90 K iSelect genotyping assay was used to survey Ethiopian germplasm for population structure, genetic diversity and marker-trait associations. Upon screening for field resistance to stripe rust in the Pacific Northwest of the United States and Ethiopia over multiple growing seasons, and against multiple races of stripe rust and stem rust at seedling stage, eight accessions displayed resistance to all tested races of stem rust and field resistance to stripe rust in all environments. Our GWAS results show 15 loci were significantly associated with seedling and adult plant resistance to stripe rust at false discovery rate (FDR)-adjusted probability (P) rust in the Ethiopian wheat accessions. Many of the identified resistance loci were mapped close to previously identified rust resistance genes; however, three loci on the short arms of chromosomes 5A and 7B for stripe rust resistance and two on chromosomes 3B and 7B for stem rust resistance may be novel. Our results demonstrate that considerable genetic variation resides within the landrace accessions that can be utilized to broaden the genetic base of rust resistance in wheat breeding germplasm. The molecular markers identified in

  3. Determinants of Profitability and Recovery from System-Wide Shocks: The Case of the Airline Industry

    Directory of Open Access Journals (Sweden)

    Benny Mantin

    2012-05-01

    Full Text Available This paper examines the determinants of profitability in the U.S. domestic airline industry, segmented into: operations strategy, productivity, and service measures, using quarterly data between 1995 and 2007. The analysis is performed separately on data prior and post 9/11 attack, revealing, among others, that after 9/11 the profitability of full-service carriers is improving faster than that of focused carriers, and that passengers are more forgivable to service glitches after 9/11 or possibly are associating lack of service with the intensified security measures imposed after 9/11. Focusing the analysis on determinants of consumers’ complaints we find further support for these arguments.

  4. Determination and Application of Comprehensive Specific Frictional Resistance in Heating Engineering

    Directory of Open Access Journals (Sweden)

    Yanan Tian

    2018-01-01

    Full Text Available In this study, we analyze the deficiencies of specific frictional resistance in heating engineering. Based on economic specific frictional resistance, we put forward the concept of comprehensive specific frictional resistance, which considers the multiple factors of technology, economy, regulation modes, pipe segment differences, and medium pressure. Then, we establish a mathematical model of a heating network across its lifespan in order to develop a method for determining the comprehensive specific frictional resistance. Relevant conclusions can be drawn from the results. As an application, we have planned the heating engineering for Yangyuan County in China, which demonstrates the feasibility and superiority of the method.

  5. A measurement method for determination of dc internal resistance of batteries and supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shuhong; Wu, Feng [Department of Materials Science, Beijing Science and Technology University, Beijing 100081 (China); Yang, Liuxiang; Gao, Lijun [Department of Chemistry, NanChang University, JiangXi 330031 (China); Burke, Andrew F. [Institute of Transportation, University of California, Davis, CA 95616 (United States)

    2010-02-15

    Internal resistance is an importance parameter determining the power performance of a battery or supercapacitor. An 8.5 Ah Li-ion battery and a 350 F supercapacitor were tested as examples to validate the measurement method of dc internal resistance. Voltage data were taken at 10 ms, 2 s and 30 s after the current interruption or pulse. The ac resistances at 1 kHz of the battery and supercapacitor were also measured for comparison with the dc values. Based on these tests, it is proposed that the dc internal resistance of the battery and supercapacitor be obtained from {delta}V/{delta}I where the {delta}V is the voltage change after the current interruption, and {delta}I means current change from I to 0. When the voltage change at 10 ms or less is selected, the resistance corresponds to the Ohmic resistance of the device. (author)

  6. 76 FR 60448 - Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton

    Science.gov (United States)

    2011-09-29

    ...] Syngenta Biotechnology, Inc.; Determination of Nonregulated Status for Lepidopteran-Resistant Cotton AGENCY... our determination that a cotton line developed by Syngenta Biotechnology, Inc., designated as event... submitted by Syngenta Biotechnology, Inc., in its petition for a determination of nonregulated status, our...

  7. Identification of loci Associated with Resistance to Root-Rot Diseases in Autotetraploid Alfalfa using Genome-Wide Sequencing and Association Mapping

    Science.gov (United States)

    Alfalfa (Medicago sativa L.) is the world-wide forage crop. Changing trends to multipurpose uses increases demand for alfalfa. However, the production of alfalfa is challenged by endemic and emerging diseases. Identification of genes/loci controlling disease resistance will facilitate breeding for i...

  8. Non-invasive determination of absolute lung resistivity in adults using electrical impedance tomography

    International Nuclear Information System (INIS)

    Zhang, Jie; Patterson, Robert

    2010-01-01

    Lung resistivity is a physiological parameter that describes the electrical characteristics of the lungs. Lung composition changes due to changes in the lung tissues, fluid and air volume. Various diseases that can cause a change in lung composition may be monitored by measuring lung resistivity. Currently, there is no accepted non-invasive method to measure lung resistivity. In this study, we presented a method and framework to non-invasively determine lung resistivity using electrical impedance tomography (EIT). By comparing actual measurements from subjects with data from a 3D human thorax model, an EIT image can be reconstructed to show a resistivity difference between the model and the subject. By adjusting the lung resistivity in the model, the resistivity difference in the lung regions can be reduced to near zero. This resistivity value then is the estimation of the lung resistivity of the subject. Using the proposed method, the lung resistivities of four normal adult males (43 ± 13 years, 78 ± 10 kg) in the supine position at air volumes starting at functional residual capacity (FRC—end expiration) and increasing in 0.5 l steps to 1.5 l were studied. The averaged lung resistivity changes 12.59%, from 1406 Ω cm to 1583 Ω cm, following the inspiration of 1.5 l air from FRC. The coefficients of variation (CV) of precision for the four subjects are less than 10%. The experiment was repeated five times at each air volume on a subject to test the reproducibility. The CVs are less than 3%. The results show that it is feasible to determine absolute lung resistivity using an EIT-based method

  9. Non-invasive determination of absolute lung resistivity in adults using electrical impedance tomography.

    Science.gov (United States)

    Zhang, Jie; Patterson, Robert

    2010-08-01

    Lung resistivity is a physiological parameter that describes the electrical characteristics of the lungs. Lung composition changes due to changes in the lung tissues, fluid and air volume. Various diseases that can cause a change in lung composition may be monitored by measuring lung resistivity. Currently, there is no accepted non-invasive method to measure lung resistivity. In this study, we presented a method and framework to non-invasively determine lung resistivity using electrical impedance tomography (EIT). By comparing actual measurements from subjects with data from a 3D human thorax model, an EIT image can be reconstructed to show a resistivity difference between the model and the subject. By adjusting the lung resistivity in the model, the resistivity difference in the lung regions can be reduced to near zero. This resistivity value then is the estimation of the lung resistivity of the subject. Using the proposed method, the lung resistivities of four normal adult males (43 +/- 13 years, 78 +/- 10 kg) in the supine position at air volumes starting at functional residual capacity (FRC--end expiration) and increasing in 0.5 l steps to 1.5 l were studied. The averaged lung resistivity changes 12.59%, from 1406 Omega cm to 1583 Omega cm, following the inspiration of 1.5 l air from FRC. The coefficients of variation (CV) of precision for the four subjects are less than 10%. The experiment was repeated five times at each air volume on a subject to test the reproducibility. The CVs are less than 3%. The results show that it is feasible to determine absolute lung resistivity using an EIT-based method.

  10. Fluoroquinolone Resistance Mechanisms in an Escherichia coli Isolate, HUE1, Without Quinolone Resistance-Determining Region Mutations

    Directory of Open Access Journals (Sweden)

    Toyotaka eSato

    2013-05-01

    Full Text Available Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor and MarR (MarA repressor were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB−TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.

  11. Mutations inside rifampicin-resistance determining region of rpoB gene associated with rifampicin-resistance in Mycobacterium tuberculosis.

    Science.gov (United States)

    Zaw, Myo T; Emran, Nor A; Lin, Zaw

    2018-04-26

    Rifampicin (RIF) plays a pivotal role in the treatment of tuberculosis due to its bactericidal effects. Because the action of RIF is on rpoB gene encoding RNA polymerase β subunit, 95% of RIF resistant mutations are present in rpoB gene. The majority of the mutations in rpoB gene are found within an 81bp RIF-resistance determining region (RRDR). Literatures on RIF resistant mutations published between 2010 and 2016 were thoroughly reviewed. The most commonly mutated codons in RRDR of rpoB gene are 531, 526 and 516. The possibilities of absence of mutation in RRDR of rpoB gene in MDR-TB isolates in few studies was due to existence of other rare rpoB mutations outside RRDR or different mechanism of rifampicin resistance. Molecular methods which can identify extensive mutations associated with multiple anti-tuberculous drugs are in urgent need so that the research on drug resistant mutations should be extended. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Genome-Wide Transcription and Functional Analyses Reveal Heterogeneous Molecular Mechanisms Driving Pyrethroids Resistance in the Major Malaria Vector Anopheles funestus Across Africa.

    Science.gov (United States)

    Riveron, Jacob M; Ibrahim, Sulaiman S; Mulamba, Charles; Djouaka, Rousseau; Irving, Helen; Wondji, Murielle J; Ishak, Intan H; Wondji, Charles S

    2017-06-07

    Pyrethroid resistance in malaria vector, An. funestus is increasingly reported across Africa, threatening the sustainability of pyrethroid-based control interventions, including long lasting insecticidal nets (LLINs). Managing this problem requires understanding of the molecular basis of the resistance from different regions of the continent, to establish whether it is being driven by a single or independent selective events. Here, using a genome-wide transcription profiling of pyrethroid resistant populations from southern (Malawi), East (Uganda), and West Africa (Benin), we investigated the molecular basis of resistance, revealing strong differences between the different African regions. The duplicated cytochrome P450 genes ( CYP6P9a and CYP6P9b ) which were highly overexpressed in southern Africa are not the most upregulated in other regions, where other genes are more overexpressed, including GSTe2 in West (Benin) and CYP9K1 in East (Uganda). The lack of directional selection on both CYP6P9a and CYP6P9b in Uganda in contrast to southern Africa further supports the limited role of these genes outside southern Africa. However, other genes such as the P450 CYP9J11 are commonly overexpressed in all countries across Africa. Here, CYP9J11 is functionally characterized and shown to confer resistance to pyrethroids and moderate cross-resistance to carbamates (bendiocarb). The consistent overexpression of GSTe2 in Benin is coupled with a role of allelic variation at this gene as GAL4-UAS transgenic expression in Drosophila flies showed that the resistant 119F allele is highly efficient in conferring both DDT and permethrin resistance than the L119. The heterogeneity in the molecular basis of resistance and cross-resistance to insecticides in An. funestus populations throughout sub-Saharan African should be taken into account in designing resistance management strategies. Copyright © 2017 Riveron et al.

  13. Genome-Wide Transcription and Functional Analyses Reveal Heterogeneous Molecular Mechanisms Driving Pyrethroids Resistance in the Major Malaria Vector Anopheles funestus Across Africa

    Science.gov (United States)

    Riveron, Jacob M.; Ibrahim, Sulaiman S.; Mulamba, Charles; Djouaka, Rousseau; Irving, Helen; Wondji, Murielle J.; Ishak, Intan H.; Wondji, Charles S.

    2017-01-01

    Pyrethroid resistance in malaria vector, An. funestus is increasingly reported across Africa, threatening the sustainability of pyrethroid-based control interventions, including long lasting insecticidal nets (LLINs). Managing this problem requires understanding of the molecular basis of the resistance from different regions of the continent, to establish whether it is being driven by a single or independent selective events. Here, using a genome-wide transcription profiling of pyrethroid resistant populations from southern (Malawi), East (Uganda), and West Africa (Benin), we investigated the molecular basis of resistance, revealing strong differences between the different African regions. The duplicated cytochrome P450 genes (CYP6P9a and CYP6P9b) which were highly overexpressed in southern Africa are not the most upregulated in other regions, where other genes are more overexpressed, including GSTe2 in West (Benin) and CYP9K1 in East (Uganda). The lack of directional selection on both CYP6P9a and CYP6P9b in Uganda in contrast to southern Africa further supports the limited role of these genes outside southern Africa. However, other genes such as the P450 CYP9J11 are commonly overexpressed in all countries across Africa. Here, CYP9J11 is functionally characterized and shown to confer resistance to pyrethroids and moderate cross-resistance to carbamates (bendiocarb). The consistent overexpression of GSTe2 in Benin is coupled with a role of allelic variation at this gene as GAL4-UAS transgenic expression in Drosophila flies showed that the resistant 119F allele is highly efficient in conferring both DDT and permethrin resistance than the L119. The heterogeneity in the molecular basis of resistance and cross-resistance to insecticides in An. funestus populations throughout sub-Saharan African should be taken into account in designing resistance management strategies. PMID:28428243

  14. Determination of the attrition resistance of granular charcoals

    International Nuclear Information System (INIS)

    Dietz, V.R.

    1979-01-01

    A laboratory procedure has been developed to evaluate the attrition of granular adsorbent charcoals on passing an air flow through the bed. Two factors observed in plant operations were selected as relevant: (1) the characteristic structural vibrations in plant scale equipment (motors, fans, etc.) that are transmitted to charcoal particles and cause the particles to move and rub each other, and (2) the rapid air flow that results in the movement of the attrited dust. In the test a container for charcoal [50 mm diameter and 50 mm high] was vibrated at a frequency of 60 Hz and at a constant energy input manually controlled using a vibration meter in the acceleration mode. Simultaneously, air was applied and exited through glass fiber filter paper. The quantity of dust trapped on the exit filter was then determined, either optically or gravimetrically. The dust formed per minute (attrition coefficient) was found to approach a constant value. The plateau-values from sequential determinations varied with the source of the charcoal; a 5-fold difference was found among a large variety of commercial products. The first testing of a sample released the excess dust accumulated in previous handling of the charcoal. The plateau values were then attained in the succeeding tests and these were characteristic of the material. The results were compared with those obtained for the same charcoals using older test methods such as the Ball and Pan Hardness Test described in RDTM16-1T

  15. Determination of Kps and β1,H in a wide interval of initial concentrations of lutetium

    International Nuclear Information System (INIS)

    Lopez-G, H.; Jimenez R, M.; Solache R, M.; Rojas H, A.

    2006-01-01

    The solubility product constants and the first of lutetium hydrolysis in the interval of initial concentration of 3.72 X 10 -5 to 2.09 X 10 -3 M of lutetium, in a 2M of NaCIO 4 media, at 303 K and under conditions free of CO 2 its were considered. The solubility diagrams (pLu (ac) -pC H ) by means of a radiochemical method were obtained, and starting from its the pC H values that limit the saturation and no-saturation zones of the solutions were settled down. Those diagrams allowed, also, to calculate the solubility product constants of Lu(OH) 3 . The experimental data to the polynomial solubility equation were adjusted, what allowed to calculate those values of the solubility product constants of Lu(OH) 3 and to determine the first hydrolysis constant. The value of precipitation pC H diminishes when the initial concentration of the lutetium increases, while the values of K ps and β 1,H its remain constant. (Author)

  16. Genome-wide association mapping of anthracnose (Collectotrichum sublineolun) resistance in U.S. sorghum association panel

    Science.gov (United States)

    The productivity and profitability of sorghum [Sorghum bicolor (L.) Moench] is reduced by susceptibility to fungal diseases such as anthracnose, which causes yield loss of both grain and biomass. A limited number of resistant accessions are present in temperate adapted germplasm, while resistant sou...

  17. Molecular Phylogenetics of Transmitted Drug Resistance in Newly Diagnosed HIV Type 1 Individuals in Denmark, a Nation-Wide Study

    DEFF Research Database (Denmark)

    Audelin, Anne Margrethe; Gerstoft, Jan; Obel, Niels

    2011-01-01

    Abstract Highly active antiretroviral treatment is compromised by viral resistance mutations. Transmitted drug resistance (TDR) is therefore monitored closely, but follow-up studies of these patients are limited. Virus from 1405 individuals diagnosed with HIV-1 in Denmark between 2001 and 2009...... without resistance mutations. We observed no difference in progression of the infection between individuals infected with TDR and individuals infected with wild-type HIV-1. The prevalence of TDR is low in Denmark and transmission of dual-drug-resistant HIV-1 is infrequent. The TDR isolates were shown...... resulting in a prevalence of 6.1%, with no changes over time. The main resistance mutations were nucleoside reverse transcriptase inhibitor (NRTI) mutation 215 revertants, as well as nonnucleoside reverse transcriptase inhibitor (NNRTI) mutation 103N/S and protease inhibitor (PI) mutations 90M and 85V...

  18. Molecular phylogenetics of transmitted drug resistance in newly diagnosed HIV Type 1 individuals in Denmark: a nation-wide study

    DEFF Research Database (Denmark)

    Audelin, Anne Margrethe; Gerstoft, Jan; Obel, Niels

    2011-01-01

    Abstract Highly active antiretroviral treatment is compromised by viral resistance mutations. Transmitted drug resistance (TDR) is therefore monitored closely, but follow-up studies of these patients are limited. Virus from 1405 individuals diagnosed with HIV-1 in Denmark between 2001 and 2009...... without resistance mutations. We observed no difference in progression of the infection between individuals infected with TDR and individuals infected with wild-type HIV-1. The prevalence of TDR is low in Denmark and transmission of dual-drug-resistant HIV-1 is infrequent. The TDR isolates were shown...... resulting in a prevalence of 6.1%, with no changes over time. The main resistance mutations were nucleoside reverse transcriptase inhibitor (NRTI) mutation 215 revertants, as well as nonnucleoside reverse transcriptase inhibitor (NNRTI) mutation 103N/S and protease inhibitor (PI) mutations 90M and 85V...

  19. Genome-wide association mapping reveals a rich genetic architecture of stripe rust resistance loci in emmer wheat (Triticum turgidum ssp. dicoccum).

    Science.gov (United States)

    Liu, Weizhen; Maccaferri, Marco; Chen, Xianming; Laghetti, Gaetano; Pignone, Domenico; Pumphrey, Michael; Tuberosa, Roberto

    2017-11-01

    SNP-based genome scanning in worldwide domesticated emmer germplasm showed high genetic diversity, rapid linkage disequilibrium decay and 51 loci for stripe rust resistance, a large proportion of which were novel. Cultivated emmer wheat (Triticum turgidum ssp. dicoccum), one of the oldest domesticated crops in the world, is a potentially rich reservoir of variation for improvement of resistance/tolerance to biotic and abiotic stresses in wheat. Resistance to stripe rust (Puccinia striiformis f. sp. tritici) in emmer wheat has been under-investigated. Here, we employed genome-wide association (GWAS) mapping with a mixed linear model to dissect effective stripe rust resistance loci in a worldwide collection of 176 cultivated emmer wheat accessions. Adult plants were tested in six environments and seedlings were evaluated with five races from the United States and one from Italy under greenhouse conditions. Five accessions were resistant across all experiments. The panel was genotyped with the wheat 90,000 Illumina iSelect single nucleotide polymorphism (SNP) array and 5106 polymorphic SNP markers with mapped positions were obtained. A high level of genetic diversity and fast linkage disequilibrium decay were observed. In total, we identified 14 loci associated with field resistance in multiple environments. Thirty-seven loci were significantly associated with all-stage (seedling) resistance and six of them were effective against multiple races. Of the 51 total loci, 29 were mapped distantly from previously reported stripe rust resistance genes or quantitative trait loci and represent newly discovered resistance loci. Our results suggest that GWAS is an effective method for characterizing genes in cultivated emmer wheat and confirm that emmer wheat is a rich source of stripe rust resistance loci that can be used for wheat improvement.

  20. Determinants of Intravascular Resistance in Indian Diabetic Nephropathy Patients: A Hospital-Based Study

    Directory of Open Access Journals (Sweden)

    Anubhav Thukral

    2011-01-01

    Full Text Available Aims and Objectives. Metabolic dysregulation has failed to explain clinical variability of patients with diabetic nephropathy and hence a renewed interest emerged in haemodynamic factors as determinant of progression and development of diabetic nephropathy. We therefore studied for various factors which can correlate with raised renal vascular resistance in diabetic nephropathy. Material and Methods. Renal vascular resistance was measured in patients with established and incipient diabetic nephropathy and compared with controls using noninvasive color Doppler examinations of intrarenal vasculature. Results. Renal vascular resistance correlated with age, duration of disease, GFR, serum creatinine, and stage of retinopathy. Renal vascular resistance was significantly reduced in patients on treatment with RAAS inhibitors and insulin, than those on OHA and antihypertensives other than RAAS inhibitors. Conclusion. The study implies that renal vascular resistance may help identify diabetics at high risk of developing nephropathy, and these set of patients could be candidates for RAAS inhibition and early insulin therapy even in patients without albuminuria.

  1. Using Resistivity Measurements to Determine Anisotropy in Soil and Weathered Rock

    Directory of Open Access Journals (Sweden)

    S. Soto-Caban

    2013-08-01

    Full Text Available This study uses electrical resistivity measurements of soils and weathered rock to perform a fast and reliable evaluation of field anisotropy. Two test sites at New Concord, Ohio were used for the study. These sites are characterized by different landform and slightly east dipping limestone and siltstone formations of Pennsylvanian age. The measured resistivity ranged from 19 Ω∙m to 100 ��∙m, and varied with depth, landform, and season. The anisotropy was determined by a comparison of resistance values along the directions of strike and the dip. Measurements showed that the orientation of electrical anisotropy in the shallow ground may vary due to fluid connection, which is determined by the pore geometry in soil and rock, as well as by the direction of fluid movement. Results from this study indicated that a portable electrical resistivity meter is sensitive and reliable enough to be used for shallow ground fluid monitoring.

  2. Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels▿ †

    Science.gov (United States)

    Fang, Fang; Li, Yin; Bumann, Mario; Raftis, Emma J.; Casey, Pat G.; Cooney, Jakki C.; Walsh, Martin A.; O'Toole, Paul W.

    2009-01-01

    Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host. PMID:19592587

  3. Antibiotic resistance determinants in a Pseudomonas putida strain isolated from a hospital.

    Directory of Open Access Journals (Sweden)

    Lázaro Molina

    Full Text Available Environmental microbes harbor an enormous pool of antibiotic and biocide resistance genes that can impact the resistance profiles of animal and human pathogens via horizontal gene transfer. Pseudomonas putida strains are ubiquitous in soil and water but have been seldom isolated from humans. We have established a collection of P. putida strains isolated from in-patients in different hospitals in France. One of the isolated strains (HB3267 kills insects and is resistant to the majority of the antibiotics used in laboratories and hospitals, including aminoglycosides, ß-lactams, cationic peptides, chromoprotein enediyne antibiotics, dihydrofolate reductase inhibitors, fluoroquinolones and quinolones, glycopeptide antibiotics, macrolides, polyketides and sulfonamides. Similar to other P. putida clinical isolates the strain was sensitive to amikacin. To shed light on the broad pattern of antibiotic resistance, which is rarely found in clinical isolates of this species, the genome of this strain was sequenced and analysed. The study revealed that the determinants of multiple resistance are both chromosomally-borne as well as located on the pPC9 plasmid. Further analysis indicated that pPC9 has recruited antibiotic and biocide resistance genes from environmental microorganisms as well as from opportunistic and true human pathogens. The pPC9 plasmid is not self-transmissible, but can be mobilized by other bacterial plasmids making it capable of spreading antibiotic resistant determinants to new hosts.

  4. Tests for determining impact resistance and strength of glass used for nuclear waste disposal

    International Nuclear Information System (INIS)

    Bunnell, L.R.

    1979-05-01

    Tests are described for determining the impact resistance (Section A) and static tensile strength (Section B) of glasses containing simulated or actual nuclear wastes. This report describes the development and use of these tests to rank different glasses, to assess effects of devitrification, and to examine the effect of impact energy on resulting surface area. For clarity this report is divided into two sections, Impact Resistance and Tensile Strength

  5. Genetically determined differences in the resistance to myocardial infarction in Wistar and August rats.

    Science.gov (United States)

    Belkina, L M; Saltykova, V A; Pshennikova, M G

    2001-06-01

    In intact August rats, the cardiac contractile function at rest was by 76% higher than in Wistar rats, while their hearts, both intact and after acute myocardial infarction, were more resistant to isometric load than the hearts of Wistar rats. Postinfarction mortality in August rats was 18% vs. 70% in Wistar rats. Adrenoreactivity of the myocardium in August rats was decreased compared to that in Wistar rats. These peculiarities can determine high resistance of August rats to myocardial infarction.

  6. Genome-Wide Transcriptional Profiling of Clostridium perfringens SM101 during Sporulation Extends the Core of Putative Sporulation Genes and Genes Determining Spore Properties and Germination Characteristics.

    Science.gov (United States)

    Xiao, Yinghua; van Hijum, Sacha A F T; Abee, Tjakko; Wells-Bennik, Marjon H J

    2015-01-01

    The formation of bacterial spores is a highly regulated process and the ultimate properties of the spores are determined during sporulation and subsequent maturation. A wide variety of genes that are expressed during sporulation determine spore properties such as resistance to heat and other adverse environmental conditions, dormancy and germination responses. In this study we characterized the sporulation phases of C. perfringens enterotoxic strain SM101 based on morphological characteristics, biomass accumulation (OD600), the total viable counts of cells plus spores, the viable count of heat resistant spores alone, the pH of the supernatant, enterotoxin production and dipicolinic acid accumulation. Subsequently, whole-genome expression profiling during key phases of the sporulation process was performed using DNA microarrays, and genes were clustered based on their time-course expression profiles during sporulation. The majority of previously characterized C. perfringens germination genes showed upregulated expression profiles in time during sporulation and belonged to two main clusters of genes. These clusters with up-regulated genes contained a large number of C. perfringens genes which are homologs of Bacillus genes with roles in sporulation and germination; this study therefore suggests that those homologs are functional in C. perfringens. A comprehensive homology search revealed that approximately half of the upregulated genes in the two clusters are conserved within a broad range of sporeforming Firmicutes. Another 30% of upregulated genes in the two clusters were found only in Clostridium species, while the remaining 20% appeared to be specific for C. perfringens. These newly identified genes may add to the repertoire of genes with roles in sporulation and determining spore properties including germination behavior. Their exact roles remain to be elucidated in future studies.

  7. Translocation of integron-associated resistance in a natural system: Acquisition of resistance determinants by Inc P and Inc W Plasmids from Salmonella enterica Typhimurium DT104

    DEFF Research Database (Denmark)

    Sandvang, Dorthe; Diggle, M.; Platt, D.J.

    2002-01-01

    to determinate the genetic content. Translocation to R751 and R388 was associated with the loss of the indigenous trimethoprim cassette to both plasmids and also acquisition of sulfonamide resistance by R751 and RP4::Tn7, which indicated movement of the 3' terminus of one or both of the DT104 integrons......Salmonella enterica Typhimurium DT104, 961368, a veterinary field isolate that encodes a chromosomal cluster of resistance genes as well as two integrons, was used to study the mobility of resistance cassettes (aadA2 and pse-1) and nonintegron-associated resistance determinants (chloramphenicol...... and tetracycline). A range of natural plasmids was used as targets for the translocation of resistance. Plasmids that acquired resistance from the DT104 chromosome were segregated by conjugation into Escherichia coli K12. Plasmids R751, R388, and RP4::Tn7 acquired several combinations of resistance determinant...

  8. Determining resistance to mastitis in a bovine subject comprises detecting the presence or absence of a genetic marker that is linked to a trait indicative of mastitis resistance

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method for determining mastitis resistance in bovine subjects, wherein mastitis resistance comprise resistance to both sub-clinical and clinical mastitis. In particular, the method of the invention involves identification of genetic markers and/or Quantitative Trait Locus...... (QTL) for the determination of mastitis resistance in a bovine subject. The determination of mastitis resistance involves resolution of the specific microsatellite status. Furthermore, the invention relates to a diagnostic kit for detection of genetic marker(s) associated with mastitis resistance....... The method and kit of the present invention can be applied for selection of bovine subjects for breeding purposes. Thus, the invention provides a method of genetically selecting bovine subjects with mastitis resistance, thereby yielding cows less prone to mastitis...

  9. DETERMINATION OF THE SPECTRUM OF ANTIBIOTIC RESISTANCE GENES HAVE PHENOTYPIC RESISTANT STRAINS OF PARIETAL INTESTINAL MICROBIOTA IN RATS BY RT-PCR

    Directory of Open Access Journals (Sweden)

    Bukina Y.V.

    2016-06-01

    resistance to glycopeptides, particularly vancomycin. Thus, of the 46 strains studied E.faecalis, 10,87% of isolates possessed Van A genes and 8,7% - Van B. Out of 50 studied cultures E.faecium 12% were in their genotype Van A and 4% - Van B. However, the frequency of detection of genes Van A and Van B in E.faecalis strains circulating in Russia, 1,7% and 2,2%, while E.faecium - 9,3% and 11,5% respectively. Bacteria of the family Peptostreptococcaceae these genes were not identified. During the molecular genetic studies we have not detected phenotypically resistant strains that have combined carbapenemases activity. Conclusions. The findings of the research results indicate the presence of carbapenem resistance genes in strains of microorganisms families Enterobacteriaceae, Bacteroidaceae and Pseudomonadaceae (P. aeruginosae, to cephalosporins - Enterobacteriaceae, Bacteroidaceae and Peptostreptococcaceae, vancomycin - from family Enterococcaceae bacteria. Phenotypically resistant strains that have combined carbapenemases activity, not revealed. Despite the wide range of activity of appointment carbapenems, cephalosporins and vancomycin should take into account the results of determination of resistance genes causing resistance to these drugs. It is advisable to creating circulation monitoring program of antibiotic-resistant strains, including those with сarbapenemases activity in humans and in the environment.

  10. Impact of a United Kingdom-wide campaign to tackle antimicrobial resistance on self-reported knowledge and behaviour change.

    Science.gov (United States)

    Chaintarli, Katerina; Ingle, Suzanne M; Bhattacharya, Alex; Ashiru-Oredope, Diane; Oliver, Isabel; Gobin, Maya

    2016-05-12

    As part of the 2014 European Antibiotic Awareness Day plans, a new campaign called Antibiotic Guardian (AG) was launched in the United Kingdom, including an online pledge system to increase commitment from healthcare professionals and members of the public to reduce antimicrobial resistance (AMR). The aim of this evaluation was to determine the impact of the campaign on self-reported knowledge and behaviour around AMR. An online survey was sent to 9016 Antibiotic Guardians (AGs) to assess changes in self-reported knowledge and behaviour (outcomes) following the campaign. Logistic regression models, adjusted for variables including age, sex and pledge group (pledging as member of public or as healthcare professional), were used to estimate associations between outcomes and AG characteristics. 2478 AGs responded to the survey (27.5 % response rate) of whom 1696 (68.4 %) pledged as healthcare professionals and 782 (31.6 %) as members of public (similar proportions to the total number of AGs). 96.3 % of all AGs who responded had prior knowledge of AMR. 73.5 % of participants were female and participants were most commonly between 45 and 54 years old. Two thirds (63.4 %) of participants reported always acting according to their pledge. Members of the public were more likely to act in line with their pledge than professionals (Odds Ratio (OR) =3.60, 95 % Confidence Interval (CI): 2.88-4.51). Approximately half of participants (44.5 %) (both healthcare professionals and members of public) reported that they acquired more knowledge about AMR post-campaign. People that were confused about AMR prior to the campaign acquired more knowledge after the campaign (OR = 3.10, 95 % CI: 1.36-7.09). More participants reported a sense of personal responsibility towards tackling AMR post-campaign, increasing from 58.3 % of participants pre-campaign to 70.5 % post-campaign. This study demonstrated that the campaign increased commitment to tackling AMR in both healthcare

  11. Determination of Screw and Nail Withdrawal Resistance of Some Important Wood Species

    Directory of Open Access Journals (Sweden)

    Alper Aytekin

    2008-04-01

    Full Text Available In this study, screw and nail withdrawal resistance of fir (Abies nordmanniana, oak (Quercus robur L. black pine (Pinus nigra Arnold and Stone pine (Pinus pinea L. wood were determined and compared. The data represent the testing of withdrawal resistance of three types of screws as smart, serrated and conventional and common nails. The specimens were prepared according to TS 6094 standards. The dimensions of the specimens were 5x5x15cm and for all of the directions. Moreover, the specimens were conditioned at ambient room temperature and 65±2% relative humidity. The screws and nails were installed according to ASTM-D 1761 standards. Nail dimensions were 2.5mm diameter and 50 mm length, conventional screws were 4x50mm, serrated screws were 4x45mm and smart screws were 4x50mm. Results show that the maximum screw withdrawal resistance value was found in Stone pine for the serrated screw. There were no significant differences between Stone pine and oak regarding screw withdrawal resistance values. Conventional screw yielded the maximum screw withdrawal resistance value in oak, followed by Stone pine, black pine and fir. Oak wood showed the maximum screw withdrawal resistance value for the smart screw, followed by Stone pine, black pine, and fir. Oak wood showed higher nail withdrawal resistances than softwood species. It was also determined that oak shows the maximum nail withdrawal resistance in all types. The nail withdrawal resistances at the longitudinal direction are lower with respect to radial and tangential directions.

  12. Mini-Mu insertions in the tetracycline resistance determinant from Proteus mirabilis

    Directory of Open Access Journals (Sweden)

    Magalhães V.D.

    1997-01-01

    Full Text Available The inducible tetracycline resistance determinant isolated from Proteus mirabilis cloned into the plasmid pACYC177 was mutagenized by insertion of a mini-Mu-lac phage in order to define the regions in the cloned sequences encoding the structural and regulatory proteins. Three different types of mutants were obtained: one lost the resistance phenotype and became Lac+; another expressed the resistance at lower levels and constitutively; the third was still dependent on induction but showed a lower minimal inhibitory concentration. The mutant phenotypes and the locations of the insertions indicate that the determinant is composed of a repressor gene and a structural gene which are not transcribed divergently as are other known tetracycline determinants isolated from Gram-negative bacteria

  13. The importance of lag time extension in determining bacterial resistance to\\ud antibiotics

    OpenAIRE

    Li, Bing; Qiu, Yong; Shi, Hanchang; Yin, Huabing

    2016-01-01

    It is widely appreciated that widespread antibiotic resistance has significantly reduced the utility of today’s antibiotics. Many antibiotics now fail to cure infectious diseases, although they are classified as effective bactericidal agents based on antibiotic susceptibility tests. Here, via kinetic growth assays, we evaluated the effects of 12 commonly used antibiotics on the lag phase of a range of pure environmental isolates and sludge bacterial communities of high diversity. We show that...

  14. If you see one, have you seen them all?: Community-wide effects of insecticide cross-resistance in zooplankton populations near and far from agriculture.

    Science.gov (United States)

    Bendis, Randall J; Relyea, Rick A

    2016-08-01

    The worldwide use of pesticides has led to increases in agricultural yields by reducing crop losses. However, increased pesticide use has resulted in pesticide-resistant pest species and recent studies have discovered pesticide-resistance in non-target species living close to farms. Such increased tolerance not only affects the species, but can alter the entire food web. Given that some species can evolve not only resistance to a single pesticide, but also cross-resistance to other pesticides that share the same mode of action, one would predict that cross-resistance to pesticides would also have effects on the entire community and affect community stability. To address this hypothesis, we conducted an outdoor mesocosm experiment comprised of 200 identical aquatic communities with phytoplankton, periphyton, and leopard frog (Lithobates pipiens) tadpoles. To these communities, we added one of four Daphnia pulex populations that we previously discovered were either resistant or sensitive to the insecticide of chlorpyrifos as a result of living close to or far from agriculture, respectively. We then exposed the communities to either no insecticide or three different concentrations of AChE-inhibiting insecticides (chlorpyrifos, malathion or carbaryl) or sodium channel-inhibiting insecticides (permethrin or cypermethrin). We discovered that communities containing sensitive Daphnia pulex experienced phytoplankton blooms and subsequent cascades through all trophic groups including amphibians at moderate to high concentrations of all five insecticides. However, communities containing resistant D. pulex were buffered from these effects at low to moderate concentrations of all AChE-inhibiting insecticides, but were not buffered against the pyrethroid insecticides. These data suggest that a simple change in the population-level resistance of zooplankton to a single insecticide can have widespread consequences for community stability and that the effects can be extrapolated

  15. Nation-wide anthropometric survey data in Japan to determine dimensions of total-body phantom for Reference Japanese Man

    International Nuclear Information System (INIS)

    Togo, Masami

    1990-01-01

    In order to estimate radiation dose in Japanese population accurately, a Reference Japanese Man, whose stature and body weight are 170cm and 60kg respectively, is indispensable. The MIRD 5 total-body phantom has only 8 dimensions, i.e. total head height, head length, head breadth, trunk length, trunk breadth, leg length, and breadth and depth of a leg model at its lower end. Based on Japanese anthropometric data, the dimensions were determined and its mathematical descriptions were given. In Japan, annual statistical data of stature, body weight, chest circumference and sitting height for all Japan by sex and age are published. But other nation-wide survey data necessary for determining dimensions of total-body phantom of Reference Japanese Man, are unavailable. Much more national anthropometric data of every kind necessary for defining phantoms must be compiled. (author)

  16. Comparison of Several Methods for Determining the Internal Resistance of Lithium Ion Cells

    Directory of Open Access Journals (Sweden)

    Hans-Georg Schweiger

    2010-06-01

    Full Text Available The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current methods, electrochemical impedance spectroscopy and thermal loss methods. The outcomes of these measurements have been compared with each other. If charge or discharge of the cell is limited, current step methods provide the same results as energy loss methods.

  17. Wide range local resistance imaging on fragile materials by conducting probe atomic force microscopy in intermittent contact mode

    Energy Technology Data Exchange (ETDEWEB)

    Vecchiola, Aymeric [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Concept Scientific Instruments, ZA de Courtaboeuf, 2 rue de la Terre de Feu, 91940 Les Ulis (France); Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Chrétien, Pascal; Schneegans, Olivier; Mencaraglia, Denis; Houzé, Frédéric, E-mail: frederic.houze@geeps.centralesupelec.fr [Laboratoire de Génie électrique et électronique de Paris (GeePs), UMR 8507 CNRS-CentraleSupélec, Paris-Sud and UPMC Universities, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette (France); Delprat, Sophie [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); UPMC, Université Paris 06, 4 place Jussieu, 75005 Paris (France); Bouzehouane, Karim; Seneor, Pierre; Mattana, Richard [Unité Mixte de Physique CNRS-Thales UMR 137, 1 avenue Augustin Fresnel, 91767 Palaiseau (France); Tatay, Sergio [Molecular Science Institute, University of Valencia, 46980 Paterna (Spain); Geffroy, Bernard [Lab. Physique des Interfaces et Couches minces (PICM), UMR 7647 CNRS-École polytechnique, 91128 Palaiseau (France); Lab. d' Innovation en Chimie des Surfaces et Nanosciences (LICSEN), NIMBE UMR 3685 CNRS-CEA Saclay, 91191 Gif-sur-Yvette (France); and others

    2016-06-13

    An imaging technique associating a slowly intermittent contact mode of atomic force microscopy (AFM) with a home-made multi-purpose resistance sensing device is presented. It aims at extending the widespread resistance measurements classically operated in contact mode AFM to broaden their application fields to soft materials (molecular electronics, biology) and fragile or weakly anchored nano-objects, for which nanoscale electrical characterization is highly demanded and often proves to be a challenging task in contact mode. Compared with the state of the art concerning less aggressive solutions for AFM electrical imaging, our technique brings a significantly wider range of resistance measurement (over 10 decades) without any manual switching, which is a major advantage for the characterization of materials with large on-sample resistance variations. After describing the basics of the set-up, we report on preliminary investigations focused on academic samples of self-assembled monolayers with various thicknesses as a demonstrator of the imaging capabilities of our instrument, from qualitative and semi-quantitative viewpoints. Then two application examples are presented, regarding an organic photovoltaic thin film and an array of individual vertical carbon nanotubes. Both attest the relevance of the technique for the control and optimization of technological processes.

  18. Genome-wide identification of lncRNAs associated with chlorantraniliprole resistance in diamondback moth Plutella xylostella (L.).

    Science.gov (United States)

    Zhu, Bin; Xu, Manyu; Shi, Haiyan; Gao, Xiwu; Liang, Pei

    2017-05-15

    Long noncoding RNAs (lncRNAs) are now considered important regulatory factors, with a variety of biological functions in many species including insects. Some lncRNAs have the ability to show rapid responses to diverse stimuli or stress factors and are involved in responses to insecticide. However, there are no reports to date on the characterization of lncRNAs associated with chlorantraniliprole resistance in Plutella xylostella. Nine RNA libraries constructed from one susceptible (CHS) and two chlorantraniliprole-resistant P. xylostella strains (CHR, ZZ) were sequenced, and 1309 lncRNAs were identified, including 877 intergenic lncRNAs, 190 intronic lncRNAs, 76 anti-sense lncRNAs and 166 sense-overlapping lncRNAs. Of the identified lncRNAs, 1059 were novel. Furthermore, we found that 64 lncRNAs were differentially expressed between CHR and CHS and 83 were differentially expressed between ZZ and CHS, of which 22 were differentially expressed in both CHR and ZZ. Most of the differentially expressed lncRNAs were hypothesized to be associated with chlorantraniliprole resistance in P. xylostella. The targets of lncRNAs via cis- ( 0.9 or xylostella. These results will facilitate future studies of the regulatory mechanisms of lncRNAs in chlorantraniliprole and other insecticide resistance and in other biological processes in P. xylostella.

  19. Prevalence of Genotypes That Determine Resistance of Staphylococci to Macrolides and Lincosamides in Serbia

    Directory of Open Access Journals (Sweden)

    Milena Mišić

    2017-08-01

    Full Text Available Macrolides, lincosamides, and streptogramins (MLS resistance genes are responsible for resistance to these antibiotics in Staphylococcus infections. The purpose of the study was to analyze the distribution of the MLS resistance genes in community- and hospital-acquired Staphylococcus isolates. The MLS resistance phenotypes [constitutive resistance to macrolide–lincosamide–streptogramin B (cMLSb, inducible resistance to macrolide–lincosamide–streptogramin B (iMLSb, resistance to macrolide/macrolide–streptogramin B (M/MSb, and resistance to lincosamide–streptogramin A/streptogramin B (LSa/b] were determined by double-disc diffusion method. The presence of the MLS resistance genes (ermA, ermB, ermC, msrA/B, lnuA, lnuB, and lsaA were determined by end-point polymerase chain reaction in 179 isolates of staphylococci collected during 1-year period at the Center for Microbiology of Public Health Institute in Vranje. The most frequent MLS phenotype among staphylococcal isolates, both community-acquired and hospital-acquired, was iMLSb (33.4%. The second most frequent was M/MSb (17.6% with statistically significantly higher number of hospital-acquired staphylococcal isolates (p < 0.05. MLS resistance was mostly determined by the presence of msrA/B (35.0% and ermC (20.8% genes. Examined phenotypes were mostly determined by the presence of one gene, especially by msrA/B (26.3% and ermC (14.5%, but 15.6% was determined by a combination of two or more genes. M/MSb phenotype was the most frequently encoded by msrA/B (95.6% gene, LSa/b phenotype by lnuA (56.3% gene, and iMLSb phenotype by ermC (29.4% and ermA (25.5% genes. Although cMLSb phenotype was mostly determined by the presence of ermC (28.9%, combinations of two or more genes have been present too. This pattern was particularly recorded in methicillin-resistant Staphylococcus aureus (MRSA (58.3% and methicillin-resistant coagulase-negative staphylococci (MRCNS (90.9% isolates with c

  20. Standard test method for determination of resistance to stable crack extension under low-constraint conditions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This standard covers the determination of the resistance to stable crack extension in metallic materials in terms of the critical crack-tip-opening angle (CTOAc), ψc and/or the crack-opening displacement (COD), δ5 resistance curve (1). This method applies specifically to fatigue pre-cracked specimens that exhibit low constraint (crack-length-to-thickness and un-cracked ligament-to-thickness ratios greater than or equal to 4) and that are tested under slowly increasing remote applied displacement. The recommended specimens are the compact-tension, C(T), and middle-crack-tension, M(T), specimens. The fracture resistance determined in accordance with this standard is measured as ψc (critical CTOA value) and/or δ5 (critical COD resistance curve) as a function of crack extension. Both fracture resistance parameters are characterized using either a single-specimen or multiple-specimen procedures. These fracture quantities are determined under the opening mode (Mode I) of loading. Influences of environment a...

  1. Socioeconomic Determinants of Ciprofloxacin-Resistant Shigella Infections in Bangladeshi Children

    Directory of Open Access Journals (Sweden)

    Randon J. Gruninger

    2017-03-01

    Full Text Available Background: Shigella species (spp. are a leading cause of moderate to severe diarrhea in children worldwide. The recent emergence of quinolone-resistant Shigella spp. gives cause for concern, and South Asia has been identified as a reservoir for global spread. The influence of socioeconomic status on antimicrobial resistance in developing countries, such as those in South Asia, remains unknown. Methods: We used data collected from 2009 to 2014 from a hospital specializing in the treatment of diarrhea in Dhaka, Bangladesh, to determine the relationship between ciprofloxacin-resistant Shigella spp. isolates and measures of socioeconomic status in Bangladeshi children less than 5 years of age. Results: We found 2.7% (230/8, 672 of children who presented with diarrhea had Shigella spp. isolated from their stool, and 50% (115/230 had resistance to ciprofloxacin. Using multivariable logistic regression analysis, we found that children from families where the father’s income was in the highest quintile had significantly higher odds of having ciprofloxacin-resistant Shigella spp. compared to children in the lowest quintile (OR = 6.1, CI 1.9-19. Factors protective against the development of resistance included access to improved sanitation (OR = 0.27, CI 0.11-0.7, and improved water sources (OR = 0.48, CI 0.25-0.92. We did not find a relationship between ciprofloxacin resistance and other proxies for socioeconomic status, including the presence of animals in the home, nutritional status, paternal education level, and the number of family members in the home. Conclusions: Although the associations between wealth and antimicrobial resistance are not fully understood, possible explanations include increased access and use of antibiotics, greater access to healthcare facilities and thus resistant pathogens, or greater consumption of commercially produced foods prepared with antibiotics.

  2. Application of Genome Wide Association and Genomic Prediction for Improvement of Cacao Productivity and Resistance to Black and Frosty Pod Diseases

    Directory of Open Access Journals (Sweden)

    J. Alberto Romero Navarro

    2017-11-01

    Full Text Available Chocolate is a highly valued and palatable confectionery product. Chocolate is primarily made from the processed seeds of the tree species Theobroma cacao. Cacao cultivation is highly relevant for small-holder farmers throughout the tropics, yet its productivity remains limited by low yields and widespread pathogens. A panel of 148 improved cacao clones was assembled based on productivity and disease resistance, and phenotypic single-tree replicated clonal evaluation was performed for 8 years. Using high-density markers, the diversity of clones was expressed relative to 10 known ancestral cacao populations, and significant effects of ancestry were observed in productivity and disease resistance. Genome-wide association (GWA was performed, and six markers were significantly associated with frosty pod disease resistance. In addition, genomic selection was performed, and consistent with the observed extensive linkage disequilibrium, high predictive ability was observed at low marker densities for all traits. Finally, quantitative trait locus mapping and differential expression analysis of two cultivars with contrasting disease phenotypes were performed to identify genes underlying frosty pod disease resistance, identifying a significant quantitative trait locus and 35 differentially expressed genes using two independent differential expression analyses. These results indicate that in breeding populations of heterozygous and recently admixed individuals, mapping approaches can be used for low complexity traits like pod color cacao, or in other species single gene disease resistance, however genomic selection for quantitative traits remains highly effective relative to mapping. Our results can help guide the breeding process for sustainable improved cacao productivity.

  3. Genome-Wide Association Study with Sequence Variants Identifies Candidate Genes for Mastitis Resistance in Dairy Cattle

    DEFF Research Database (Denmark)

    Sahana, Goutam; Guldbrandtsen, Bernt; Bendixen, Christian

    Six genomic regions affecting clinical mastitis were identified through a GWAS study with imputed BovineHD chip genotype data in the Nordic Holstein cattle population. The association analyses were carried out using a SNP-by-SNP analysis by fitting the regression of allele dosage and a polygenic...... Effect Predictor (VEP) vers. 2.6 using ENSEMBL vers. 67 databases. Candidate polymorphisms affecting clinical mastitis were selected based on their association with the traits and functional annotations. A strong positional candidate gene for mastitis resistance on chromosome-6 is the NPFFR2 which...... Factor Receptor Alpha (LIFR) emerged as a strong candidate gene for mastitis resistance. The LIFR gene is involved in acute phase response and is expressed in saliva and mammary gland....

  4. Genome-wide identification and characterization of NB-ARC resistant genes in wheat (Triticum aestivum L.) and their expression during leaf rust infection.

    Science.gov (United States)

    Chandra, Saket; Kazmi, Andaleeb Z; Ahmed, Zainab; Roychowdhury, Gargi; Kumari, Veena; Kumar, Manish; Mukhopadhyay, Kunal

    2017-07-01

    NB-ARC domain-containing resistance genes from the wheat genome were identified, characterized and localized on chromosome arms that displayed differential yet positive response during incompatible and compatible leaf rust interactions. Wheat (Triticum aestivum L.) is an important cereal crop; however, its production is affected severely by numerous diseases including rusts. An efficient, cost-effective and ecologically viable approach to control pathogens is through host resistance. In wheat, high numbers of resistance loci are present but only few have been identified and cloned. A comprehensive analysis of the NB-ARC-containing genes in complete wheat genome was accomplished in this study. Complete NB-ARC encoding genes were mined from the Ensembl Plants database to predict 604 NB-ARC containing sequences using the HMM approach. Genome-wide analysis of orthologous clusters in the NB-ARC-containing sequences of wheat and other members of the Poaceae family revealed maximum homology with Oryza sativa indica and Brachypodium distachyon. The identification of overlap between orthologous clusters enabled the elucidation of the function and evolution of resistance proteins. The distributions of the NB-ARC domain-containing sequences were found to be balanced among the three wheat sub-genomes. Wheat chromosome arms 4AL and 7BL had the most NB-ARC domain-containing contigs. The spatio-temporal expression profiling studies exemplified the positive role of these genes in resistant and susceptible wheat plants during incompatible and compatible interaction in response to the leaf rust pathogen Puccinia triticina. Two NB-ARC domain-containing sequences were modelled in silico, cloned and sequenced to analyze their fine structures. The data obtained in this study will augment isolation, characterization and application NB-ARC resistance genes in marker-assisted selection based breeding programs for improving rust resistance in wheat.

  5. Genome-Wide Association Study for Identification and Validation of Novel SNP Markers for Sr6 Stem Rust Resistance Gene in Bread Wheat.

    Science.gov (United States)

    Mourad, Amira M I; Sallam, Ahmed; Belamkar, Vikas; Wegulo, Stephen; Bowden, Robert; Jin, Yue; Mahdy, Ezzat; Bakheit, Bahy; El-Wafaa, Atif A; Poland, Jesse; Baenziger, Peter S

    2018-01-01

    Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat ( Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of stem rust resistance in Nebraska winter wheat, we applied genome-wide association study (GWAS) on a set of 270 winter wheat genotypes (A-set). Genotyping was carried out using genotyping-by-sequencing and ∼35,000 high-quality SNPs were identified. The tested genotypes were evaluated for their resistance to the common stem rust race in Nebraska (QFCSC) in two replications. Marker-trait association identified 32 SNP markers, which were significantly (Bonferroni corrected P < 0.05) associated with the resistance on chromosome 2D. The chromosomal location of the significant SNPs (chromosome 2D) matched the location of Sr6 gene which was expected in these genotypes based on pedigree information. A highly significant linkage disequilibrium (LD, r 2 ) was found between the significant SNPs and the specific SSR marker for the Sr6 gene ( Xcfd43 ). This suggests the significant SNP markers are tagging Sr6 gene. Out of the 32 significant SNPs, eight SNPs were in six genes that are annotated as being linked to disease resistance in the IWGSC RefSeq v1.0. The 32 significant SNP markers were located in nine haplotype blocks. All the 32 significant SNPs were validated in a set of 60 different genotypes (V-set) using single marker analysis. SNP markers identified in this study can be used in marker-assisted selection, genomic selection, and to develop KASP (Kompetitive Allele Specific PCR) marker for the Sr6 gene. Novel SNPs for Sr6 gene, an important stem rust resistant gene, were identified and validated in this study. These SNPs can be used to improve stem rust resistance in wheat.

  6. Antibiotic Resistance in Foodborne Pathogens

    OpenAIRE

    Walsh, Ciara; Duffy, Geraldine

    2013-01-01

    Wide-spread antibiotic resistance among bacterial pathogens is now a serious public health issue and multi-antibiotic resistance has been reported in many foodborne pathogens including Salmonella and E. coli. A study to determine antibiotic resistance profiles of a range of Salmonella and Verocytotoxigenic E.coli (VTEC) isolated from Irish foods revealed significant levels of antibiotic resistance in the strains. S. typhimurium DT104 were multiantibiotic resistant with 97% resistant to 7 anti...

  7. Determination Pattern of Antibiotic Resistance in Entropathogenic Escherichia coli Strains Isolated from Children with Diarrhea

    Directory of Open Access Journals (Sweden)

    P. Karami

    2012-04-01

    Full Text Available Introduction & Objective: Diarrheal diseases are considered a major health problem, especially in children. Enteropathogenic Escherichia coli (EPEC strains are the common cause of diarrhea in children especially in developing countries. Because of undesirable effects of diarrhea and its interference with children's growth, in some cases antibiotic treatment is recommended. In recent years, resistance toward common and effective antibiotics in the treatment of infectious diseases became one of the most important challenges in medical society, for this purpose, antibiotic sensitivity and resistance of strains in every geographical zone must be determined. So in this study, of antibiotic patterns of these bacteria were examined.Materials & Methods: This cross-sectional study was performed on 192 strains of Enteropathogen Escherichia coli isolated from children who were suffering from diarrhea in 1389-1390 in the microbiology laboratory of Hamadan University of medical sciences. To identify these strains, standard biochemical and serology tests were used. The antibiotic sensitivity test of these isolates was carried out with disc diffusion agar method according to the CLSI standards for 14 different antibiotics disc. Resistance toward 3 or more than 3 classes of antibiotics were defined as multidrug resistance.Results: The result of this study shows EPEC strains had the highest resistance to cefpodoxime (97%, trimethoprim (60.7%, tetracycline (58.4% and ampicillin (45.8%. Multidrug resistance was 68.7 percent. These strains also showed the highest sensitivity against imipenem, ceftriaxone, and ciprofloxacin antibiotics.Conclusion: EPEC strains that were studied with resistance to ampicillin, tetracycline and convenient sensitivity against fluoroquinolones are one of the major factors in children’s diarrhea. A result of this research suggests that antimicrobial resistance in Escherichia coli strains are high and prescribing and antibiotic is not

  8. Fine mapping of a Phytophthora-resistance gene RpsWY in soybean (Glycine max L.) by high-throughput genome-wide sequencing.

    Science.gov (United States)

    Cheng, Yanbo; Ma, Qibin; Ren, Hailong; Xia, Qiuju; Song, Enliang; Tan, Zhiyuan; Li, Shuxian; Zhang, Gengyun; Nian, Hai

    2017-05-01

    Using a combination of phenotypic screening, genetic and statistical analyses, and high-throughput genome-wide sequencing, we have finely mapped a dominant Phytophthora resistance gene in soybean cultivar Wayao. Phytophthora root rot (PRR) caused by Phytophthora sojae is one of the most important soil-borne diseases in many soybean-production regions in the world. Identification of resistant gene(s) and incorporating them into elite varieties are an effective way for breeding to prevent soybean from being harmed by this disease. Two soybean populations of 191 F 2 individuals and 196 F 7:8 recombinant inbred lines (RILs) were developed to map Rps gene by crossing a susceptible cultivar Huachun 2 with the resistant cultivar Wayao. Genetic analysis of the F 2 population indicated that PRR resistance in Wayao was controlled by a single dominant gene, temporarily named RpsWY, which was mapped on chromosome 3. A high-density genetic linkage bin map was constructed using 3469 recombination bins of the RILs to explore the candidate genes by the high-throughput genome-wide sequencing. The results of genotypic analysis showed that the RpsWY gene was located in bin 401 between 4466230 and 4502773 bp on chromosome 3 through line 71 and 100 of the RILs. Four predicted genes (Glyma03g04350, Glyma03g04360, Glyma03g04370, and Glyma03g04380) were found at the narrowed region of 36.5 kb in bin 401. These results suggest that the high-throughput genome-wide resequencing is an effective method to fine map PRR candidate genes.

  9. Determination of Soil Moisture Content using Laboratory Experimental and Field Electrical Resistivity Values

    Science.gov (United States)

    Hazreek, Z. A. M.; Rosli, S.; Fauziah, A.; Wijeyesekera, D. C.; Ashraf, M. I. M.; Faizal, T. B. M.; Kamarudin, A. F.; Rais, Y.; Dan, M. F. Md; Azhar, A. T. S.; Hafiz, Z. M.

    2018-04-01

    The efficiency of civil engineering structure require comprehensive geotechnical data obtained from site investigation. In the past, conventional site investigation was heavily related to drilling techniques thus suffer from several limitations such as time consuming, expensive and limited data collection. Consequently, this study presents determination of soil moisture content using laboratory experimental and field electrical resistivity values (ERV). Field and laboratory electrical resistivity (ER) test were performed using ABEM SAS4000 and Nilsson400 soil resistance meter. Soil sample used for resistivity test was tested for characterization test specifically on particle size distribution and moisture content test according to BS1377 (1990). Field ER data was processed using RES2DINV software while laboratory ER data was analyzed using SPSS and Excel software. Correlation of ERV and moisture content shows some medium relationship due to its r = 0.506. Moreover, coefficient of determination, R2 analyzed has demonstrate that the statistical correlation obtain was very good due to its R2 value of 0.9382. In order to determine soil moisture content based on statistical correlation (w = 110.68ρ-0.347), correction factor, C was established through laboratory and field ERV given as 19.27. Finally, this study has shown that soil basic geotechnical properties with particular reference to water content was applicably determined using integration of laboratory and field ERV data analysis thus able to compliment conventional approach due to its economic, fast and wider data coverage.

  10. Determination of resistance to salt crystallization on natural stone measured with ultrasonic wave

    DEFF Research Database (Denmark)

    Alm, D.; Brix, S.; Kjærgaard, H. Howe

    2008-01-01

    and after salt exposure. Four different stones are investigated: the limestone Bateig Azul, the sandstone Oberkirchener, the limestone Perlatino, and the limestone Travertine. The procedure for the salt crystallization test is EN 12370 standard “Natural stone test methods – Determination of resistance...

  11. The role of height-associated loci identified in genome wide association studies in the determination of pediatric stature

    Directory of Open Access Journals (Sweden)

    Frackelton Edward C

    2010-06-01

    Full Text Available Abstract Background Human height is considered highly heritable and correlated with certain disorders, such as type 2 diabetes and cancer. Despite environmental influences, genetic factors are known to play an important role in stature determination. A number of genetic determinants of adult height have already been established through genome wide association studies. Methods To examine 51 single nucleotide polymorphisms (SNPs corresponding to the 46 previously reported genomic loci for height in 8,184 European American children with height measurements. We leveraged genotyping data from our ongoing GWA study of height variation in children in order to query the 51 SNPs in this pediatric cohort. Results Sixteen of these SNPs yielded at least nominally significant association to height, representing fifteen different loci including EFEMP1-PNPT1, GPR126, C6orf173, SPAG17, Histone class 1, HLA class III and GDF5-UQCC. Other loci revealed no evidence for association, including HMGA1 and HMGA2. For the 16 associated variants, the genotype score explained 1.64% of the total variation for height z-score. Conclusion Among 46 loci that have been reported to associate with adult height to date, at least 15 also contribute to the determination of height in childhood.

  12. Antibiotic Resistance Determinant-Focused Acinetobacter baumannii Vaccine Designed Using Reverse Vaccinology.

    Science.gov (United States)

    Ni, Zhaohui; Chen, Yan; Ong, Edison; He, Yongqun

    2017-02-21

    As one of the most influential and troublesome human pathogens, Acinetobacter baumannii ( A. baumannii ) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1). CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA), 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.

  13. Significance of Coexisting Mutations on Determination of the Degree of Isoniazid Resistance in Mycobacterium tuberculosis Strains.

    Science.gov (United States)

    Karunaratne, Galbokka Hewage Roshanthi Eranga; Wijesundera, Sandhya Sulochana; Vidanagama, Dhammika; Adikaram, Chamila Priyangani; Perera, Jennifer

    2018-04-23

    The emergence and spread of drug-resistant tuberculosis (TB) pose a threat to TB control in Sri Lanka. Isoniazid (INH) is a key element of the first-line anti-TB treatment regimen. Resistance to INH is mainly associated with point mutations in katG, inhA, and ahpC genes. The objective of this study was to determine mutations of these three genes in INH-resistant Mycobacterium tuberculosis (MTb) strains in Sri Lanka. Complete nucleotide sequence of the three genes was amplified by polymerase chain reaction and subjected to DNA sequencing. Point mutations in the katG gene were identified in 93% isolates, of which the majority (78.6%) were at codon 315. Mutations at codons 212 and 293 of the katG gene have not been reported previously. Novel mutations were recognized in the promoter region of the inhA gene (C deletion at -34), fabG1 gene (codon 27), and ahpC gene (codon 39). Single S315T mutation in the katG gene led to a high level of resistance, while a low level of resistance with high frequency (41%) was observed when katG codon 315 coexisted with the mutation at codon 463. Since most of the observed mutations of all three genes coexisted with the katG315 mutation, screening of katG315 mutations will be a useful marker for molecular detection of INH resistance of MTb in Sri Lanka.

  14. An Autonomous Ultra-Wide Band-Based Attitude and Position Determination Technique for Indoor Mobile Laser Scanning

    Directory of Open Access Journals (Sweden)

    Lawrence Lau

    2018-04-01

    Full Text Available Mobile laser scanning (MLS has been widely used in three-dimensional (3D city modelling data collection, such as Google cars for Google Map/Earth. Building Information Modelling (BIM has recently emerged and become prominent. 3D models of buildings are essential for BIM. Static laser scanning is usually used to generate 3D models for BIM, but this method is inefficient if a building is very large, or it has many turns and narrow corridors. This paper proposes using MLS for BIM 3D data collection. The positions and attitudes of the mobile laser scanner are important for the correct georeferencing of the 3D models. This paper proposes using three high-precision ultra-wide band (UWB tags to determine the positions and attitudes of the mobile laser scanner. The accuracy of UWB-based MLS 3D models is assessed by comparing the coordinates of target points, as measured by static laser scanning and a total station survey.

  15. Insulin Sensitivity Determines Effects of Insulin and Meal Ingestion on Systemic Vascular Resistance in Healthy Subjects.

    Science.gov (United States)

    Woerdeman, Jorn; Meijer, Rick I; Eringa, Etto C; Hoekstra, Trynke; Smulders, Yvo M; Serné, Erik H

    2016-01-01

    In addition to insulin's metabolic actions, insulin can dilate arterioles which increase blood flow to metabolically active tissues. This effect is blunted in insulin-resistant subjects. Insulin's effect on SVR, determined by resistance arterioles, has, however, rarely been examined directly. We determined the effects of both hyperinsulinemia and a mixed meal on SVR and its relationship with insulin sensitivity. Thirty-seven lean and obese women underwent a hyperinsulinemic-euglycemic clamp, and 24 obese volunteers underwent a mixed-meal test. SVR was assessed using CPP before and during hyperinsulinemia as well as before and 60 and 120 minutes after a meal. SVR decreased significantly during hyperinsulinemia (-13%; p Insulin decreased SVR more strongly in insulin-sensitive individuals (standardized β: -0.44; p = 0.01). In addition, SVR at 60 minutes after meal ingestion was inversely related to the Matsuda index (β: -0.39; p = 0.04) and the change in postprandial SVR was directly related to postprandial glycemia (β: 0.53; p insulin resistance. This suggests that resistance to insulin-induced vasodilatation contributes to regulation of vascular resistance. © 2015 John Wiley & Sons Ltd.

  16. Exploration of genetically determined resistance against hepatitis C infection in high-risk injecting drug users.

    Science.gov (United States)

    Sugden, P B; Cameron, B; Luciani, F; Lloyd, A R

    2014-08-01

    Genetic resistance to specific infections is well recognized. In hepatitis C virus (HCV) infection, genetic polymorphisms in IL-28B and the killer cell immunoglobulin-like receptors (KIR) and their HLA class I ligands have been shown to affect clearance of the virus following infection. There are limited data regarding resistance to established HCV infection. Reliable quantification of repeated exposure in high-risk populations, such as injecting drug users (IDU), is a key limitation of previous studies of resistance. Behavioural data and DNA from IDU (n = 210) in the Hepatitis C Incidence and Transmission Study in prisons (HITS-p) cohort were genotyped for polymorphisms in: IL-28B, peptidyl-prolyl isomerase A (PPIA), HLA-C and KIR2. To quantify risk, a composite risk index based on factors predictive of incident HCV infection was derived. Logistic regression analysis revealed the risk index was strongly associated with incident HCV infection (P C1, or their combination. A framework for the investigation of genetic determinants of resistance to HCV infection has been developed. Several candidate gene associations were investigated and excluded. Further investigation of genetic determinants of resistance to HCV infection is warranted. © 2014 John Wiley & Sons Ltd.

  17. State-wide surveillance of antibiotic resistance patterns and spa types of methicillin-resistant Staphylococcus aureus from blood cultures in North Rhine-Westphalia, 2011-2013.

    Science.gov (United States)

    Cuny, C; Layer, F; Werner, G; Harmsen, D; Daniels-Haardt, I; Jurke, A; Mellmann, A; Witte, W; Köck, R

    2015-08-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of bacteraemia. We aimed to obtain a complete picture of severe MRSA infections by characterizing all MRSA isolates from bloodstream infections in the largest German federal state (North Rhine-Westphalia, 18 million inhabitants) using S. aureus protein A (spa) sequence-typing and antimicrobial susceptibility testing. MRSA isolates (n = 1952) were collected prospectively (2011-2013) and spa-typed. Among 181 different spa types, t003 (n = 746 isolates; 38.2%) and t032 (n = 594; 30.4%) were predominant. Analysis of the geographical occurrence of spa clonal complexes (spa-CCs) and spa types revealed divergent distribution between federal state districts for spa-CCs 003 (p resistant to fluoroquinolones, 78% to erythromycin, 70% to clindamycin, 4% to gentamicin, 2% to rifampicin, 0.4% to daptomycin, 0.1% to linezolid and 0% to vancomycin, respectively. Vancomycin MICs of 2 mg/L involved 0.5% of the isolates. In conclusion, the detection of regional molecular clusters added valuable information for epidemiological case tracing and allowed conclusions to be reached on the importance of newly emerging MRSA reservoirs, such as livestock (spa-CC011), for MRSA bacteraemia in some parts of the federal state. Susceptibility testing revealed broad resistance to substances used for oral treatment, but demonstrated that those antibiotics that are mostly applied for treatment of MRSA bacteraemia and important combination partners were highly susceptible. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Wide dissemination of linezolid-resistant Staphylococcus epidermidis in Greece is associated with a linezolid-dependent ST22 clone.

    Science.gov (United States)

    Karavasilis, Vasilios; Zarkotou, Olympia; Panopoulou, Maria; Kachrimanidou, Melina; Themeli-Digalaki, Katerina; Stylianakis, Antonios; Gennimata, Vassiliki; Ntokou, Eleni; Stathopoulos, Constantinos; Tsakris, Athanasios; Pournaras, Spyros

    2015-01-01

    Dependence on linezolid was recently described as significant growth acceleration of linezolid-resistant Staphylococcus epidermidis (LRSE) isolates upon linezolid exposure. We investigated the possible contribution of linezolid dependence to LRSE dissemination in Greece. Linezolid resistance rates were estimated in six tertiary hospitals located throughout Greece between 2011 and 2013. Sixty-three randomly selected LRSE recovered in these hospitals during this period were studied. Growth curve analysis was conducted with and without linezolid. Clonality of the isolates was investigated by PFGE and MLST. During the study period, the LRSE rate in the participating hospitals rose significantly from 6.9% to 9% (P = 0.006); the increase was more prominent in ICUs (from 15.1% to 20.9%; P = 0.005). Forty-seven (74.6%) of the 63 LRSE, derived from all study hospitals, clearly exhibited linezolid dependence, growing significantly faster in the presence of 16 and 32 mg/L linezolid. Of note, 61 (96.8%) LRSE exhibited a single macrorestriction pattern and belonged to ST22, which included all linezolid-dependent LRSE. The remaining two LRSE belonged to unique STs. Five of six linezolid-dependent isolates tested also exhibited linezolid dependence upon exposure to 8 mg/L linezolid. Interestingly, five of six ST22 linezolid-non-dependent isolates tested developed linezolid dependence when linezolid exposure preceded growth analysis. The rapid LRSE dissemination in Greek hospitals threatens linezolid activity. The observation that most LRSE belonged to ST22 and expressed dependence on linezolid clearly implies that the spread of linezolid resistance should have been driven by this trait, which provided the LRSE with a selective advantage under linezolid pressure. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Use of the azimuthal resistivity technique for determination of regional azimuth of transmissivity

    Science.gov (United States)

    Carlson, D.

    2010-01-01

    Many bedrock units contain joint sets that commonly act as preferred paths for the movement of water, electrical charge, and possible contaminants associated with production or transit of crude oil or refined products. To facilitate the development of remediation programs, a need exists to reliably determine regional-scale properties of these joint sets: azimuth of transmissivity ellipse, dominant set, and trend(s). The surface azimuthal electrical resistivity survey method used for local in situ studies can be a noninvasive, reliable, efficient, and relatively cost-effective method for regional studies. The azimuthal resistivity survey method combines the use of standard resistivity equipment with a Wenner array rotated about a fixed center point, at selected degree intervals, which yields an apparent resistivity ellipse from which joint-set orientation can be determined. Regional application of the azimuthal survey method was tested at 17 sites in an approximately 500 km2 (193 mi2) area around Milwaukee, Wisconsin, with less than 15m (50 ft) overburden above the dolomite. Results of 26 azimuthal surveys were compared and determined to be consistent with the results of two other methods: direct observation of joint-set orientation and transmissivity ellipses from multiple-well-aquifer tests. The average of joint-set trend determined by azimuthal surveys is within 2.5?? of the average of joint-set trend determined by direct observation of major joint sets at 24 sites. The average of maximum of transmissivity trend determined by azimuthal surveys is within 5.7?? of the average of maximum of transmissivity trend determined for 14 multiple-well-aquifer tests. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  20. A genome-wide approach accounting for body mass index identifies genetic variants influencing fasting glycemic traits and insulin resistance

    DEFF Research Database (Denmark)

    Manning, Alisa K; Hivert, Marie-France; Scott, Robert A

    2012-01-01

    pathways might be uncovered by accounting for differences in body mass index (BMI) and potential interactions between BMI and genetic variants. We applied a joint meta-analysis approach to test associations with fasting insulin and glucose on a genome-wide scale. We present six previously unknown loci...... associated with fasting insulin at P triglyceride and lower high-density lipoprotein (HDL) cholesterol levels, suggesting a role for these loci...

  1. A genome-wide association study of a global rice panel reveals resistance in Oryza sativa to root-knot nematodes.

    Science.gov (United States)

    Dimkpa, Stanley O N; Lahari, Zobaida; Shrestha, Roshi; Douglas, Alex; Gheysen, Godelieve; Price, Adam H

    2016-02-01

    The root-knot nematode Meloidogyne graminicola is one of the most serious nematode pests worldwide and represents a major constraint on rice production. While variation in the susceptibility of Asian rice (Oryza sativa) exists, so far no strong and reliable resistance has been reported. Quantitative trait loci for partial resistance have been reported but no underlying genes have been tagged or cloned. Here, 332 accessions of the Rice Diversity Panel 1 were assessed for gall formation, revealing large variation across all subpopulations of rice and higher susceptibility in temperate japonica accessions. Accessions Khao Pahk Maw and LD 24 appeared to be resistant, which was confirmed in large pot experiments where no galls were observed. Detailed observations on these two accessions revealed no nematodes inside the roots 2 days after inoculation and very few females after 17 days (5 in Khao Pahk Maw and 100 in the susceptible controls). These two cultivars appear ideal donors for breeding root-knot nematode resistance. A genome-wide association study revealed 11 quantitative trait loci, two of which are close to epistatic loci detected in the Bala x Azucena population. The discussion highlights a small number of candidate genes worth exploring further, in particular many genes with lectin domains and genes on chromosome 11 with homology to the Hordeum Mla locus. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  2. Variable wide range of lens power and its improvement in a liquid-crystal lens using highly resistive films divided into two regions with different diameters

    Science.gov (United States)

    Kawamura, Marenori; Sato, Susumu

    2018-05-01

    The variable range of lens power of a liquid-crystal (LC) lens driven by two voltages is discussed on the basis of calculated and experimental results. The LC lens has two electrodes, which are a circularly hole-patterned electrode and a circular electrode, in addition to a common electrode, and highly resistive transparent films. The variable range of lens power increases with increasing driving voltage applied across the circularly hole-patterned electrode and the common electrode, and with decreasing diameter of highly resistive films. However, the optical-phase retardation profile tends to deviate from a parabolic curve in these cases. As a method to improve the trade-off properties, the highly resistive film is divided into two regions with different diameters, where the sheet resistance of an outer film is larger than that of an inner one. The improved LC lens has a lens power that varies in a wide range, and it exhibits a good parabolic phase retardation profile.

  3. Genome-wide analysis of the regulatory function mediated by the small regulatory psm-mec RNA of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Cheung, Gordon Y C; Villaruz, Amer E; Joo, Hwang-Soo; Duong, Anthony C; Yeh, Anthony J; Nguyen, Thuan H; Sturdevant, Daniel E; Queck, S Y; Otto, M

    2014-07-01

    Several methicillin resistance (SCCmec) clusters characteristic of hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) strains harbor the psm-mec locus. In addition to encoding the cytolysin, phenol-soluble modulin (PSM)-mec, this locus has been attributed gene regulatory functions. Here we employed genome-wide transcriptional profiling to define the regulatory function of the psm-mec locus. The immune evasion factor protein A emerged as the primary conserved and strongly regulated target of psm-mec, an effect we show is mediated by the psm-mec RNA. Furthermore, the psm-mec locus exerted regulatory effects that were more moderate in extent. For example, expression of PSM-mec limited expression of mecA, thereby decreasing methicillin resistance. Our study shows that the psm-mec locus has a rare dual regulatory RNA and encoded cytolysin function. Furthermore, our findings reveal a specific mechanism underscoring the recently emerging concept that S. aureus strains balance pronounced virulence and high expression of antibiotic resistance. Published by Elsevier GmbH.

  4. Determination of a Wear Initiation Cycle by using a Contact Resistance Measurement in Nuclear Fuel Fretting

    International Nuclear Information System (INIS)

    Lee, Young Ho; Kim, Hyung Kyu

    2008-01-01

    In nuclear fuel fretting, the improving of the contact condition with a modified spring shape is a useful method for increasing the wear resistance of the nuclear fuel rod. This is because the fretting wear resistance between the fuel rod and grid spring is mainly affected by the grid spring shape rather than the environment, the contact modes, etc. In addition, the wear resistance is affected by the wear debris behavior between contact surfaces. So, it is expected that the wear initiation of each spring shape should be determined in order to evaluate a wear resistance. However, it is almost impossible to measure the wear behavior in contact surfaces on a real time basis because the contact surfaces are always hidden. Besides, the results of the worn surface observation after the fretting wear tests are restricted to archive the information on the wear debris behavior and the formation mechanism of the wear scar. In order to evaluate the wear behavior during the fretting wear tests, it is proposed that the contact resistance measurement is a useful method for examining the wear initiation cycle and modes. Generally, fretting wear damages are rapidly progressed by a localized plastic deformation between the contact surfaces, crack initiation and fracture of the deformed surface with a strain hardening difference between a surface and a subsurface and finally a detachment of wear debris. After this, wear debris is easily oxidized by frictional heat, test environment, etc. At this time, a small amount of electric current applied between the contact surfaces will be influenced by the wear debris, which could be an obstacle to an electric current flow. So, it is possible to archive the information on the wear behavior by measuring the contact resistance. In order to determine the wear initiation cycle during the fretting wear tests, in this study, fretting wear tests have been performed by applying a constant electric current in room temperature air

  5. Comparative Analysis of Three Methods for Determination of Imipenem Resistance in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Tanaz Zabihi

    2016-02-01

    Full Text Available "> Background: These days, the antibiotic resistance of Pseudomonas aeruginosa isolates toimipenem has significantly increased. Therefore the study of resistance to imipenem in thisorganism to imipenem in determining the appropriate treatment is crucial and necessary. The goalof this study is to compare three phenotypic methods of E-test, disk diffusion and micro brothdilution in the study of resistance to imipenem in clinical isolates of P. aeruginosa.Methods: Within a 6-month interval, 120 clinical specimens were collected and evaluated. Allisolates were identified as P. aeruginosa by standard biochemical tests and amplification of 16SrRNA gene. Three phenotypic methods of E-test, disk diffusion, and micro broth dilution wereused to determine imipenem resistance in P. aeruginosa isolates.Results: Of the 96 P. aeruginosa isolates studied for their resistance to imipenem by the use ofE-test, disk diffusion and micro broth dilution methods, 38.5% of the strains in micro broth dilutionmethod and 33.3% in the two methods of E-test and disk diffusion were resistant to imipenem. Therate of sensitivity and specificity of disk diffusion and E-test methods were 100%, 90.1%, and theywere 100% and 83.1% for micro broth dilution, respectively.Conclusions: With regard to the results obtained from the comparison of the three methods100% agreement were observed among the antimicrobial susceptibility results obtained by the Etest and disk diffusion methods (P ≥ 0.05. Therefore, the use of disk diffusion method can bean appropriate replacement for E-test method with regard to its being easy and cost-effective.

  6. Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Ana Teresa P. Carvalho

    2014-01-01

    Full Text Available OBJECTIVES: Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro. METHODS: We analyzed 123 Crohn's disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn's disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations. RESULTS: No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn's disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn's disease than in ulcerative colitis (p = 0.047. A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn's disease (OR: 4.13; p = 0.009, whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094. In Crohn's disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010. However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories. CONCLUSION: The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn's disease. This association with Crohn's disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut

  7. The costs of infection and resistance as determinants of West Nile virus susceptibility in Culex mosquitoes

    Directory of Open Access Journals (Sweden)

    Styer Linda M

    2011-10-01

    Full Text Available Abstract Background Understanding the phenotypic consequences of interactions between arthropod-borne viruses (arboviruses and their mosquito hosts has direct implications for predicting the evolution of these relationships and the potential for changes in epidemiological patterns. Although arboviruses are generally not highly pathogenic to mosquitoes, pathology has at times been noted. Here, in order to evaluate the potential costs of West Nile virus (WNV infection and resistance in a primary WNV vector, and to assess the extent to which virus-vector relationships are species-specific, we performed fitness studies with and without WNV exposure using a highly susceptible Culex pipiens mosquito colony. Specifically, we measured and compared survival, fecundity, and feeding rates in bloodfed mosquitoes that were (i infected following WNV exposure (susceptible, (ii uninfected following WNV exposure (resistant, or (iii unexposed. Results In contrast to our previous findings with a relatively resistant Cx. tarsalis colony, WNV infection did not alter fecundity or blood-feeding behaviour of Cx. pipiens, yet results do indicate that resistance to infection is associated with a fitness cost in terms of mosquito survival. Conclusions The identification of species-specific differences provides an evolutionary explanation for variability in vector susceptibility to arboviruses and suggests that understanding the costs of infection and resistance are important factors in determining the potential competence of vector populations for arboviruses.

  8. Identification and Determination of Drug Resistant of Candida species isolated from Hospital Acquired Infections

    Directory of Open Access Journals (Sweden)

    Kambiz Diba

    2015-01-01

    Full Text Available Background & aim: Currently, the use of antifungal azole group and yeasts resistant to these drugs is increasing. The aim of this study was to isolate and identify the yeasts obtained from candidiasis patients and furthermore determining thier antifungal resistance. Methods: In the present descriptive study, infections samples were collected from 256 patients with suspected nosocomial candidiasis, then direct exam and culture were performed. Yeast colonies were identified using phenotypic methods, polymerase chain reaction method and enzyme digestion. Data were analyzed using Descriptive statistical tests. Results: Of sixty isolated yeast, thirty-seven cases of Candida albicans (61.6%, seven cases of C. krusei and C. glabrata (11.6% each, five cases of C. dubliniensis (8.3% and four cases of C. tropicalis (6.6% were indicated. The study showed that the sensitivity of C. albicans and C. cruise species to amphotericin B was negligible in disk diffusion and very sensitve in microdilution. Conclusion: Inspite of the results of antifungal susceptibility test of strains studied did not show high resistance, but screening for drug-resistant Candida isolates in Candida infection by disk diffusion and microdilution methods for new cases of drug resistance is reasonable.

  9. Effectiveness of hospital-wide methicillin-resistant Staphylococcus aureus (MRSA infection control policies differs by ward specialty.

    Directory of Open Access Journals (Sweden)

    Rosemarie Sadsad

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major cause of preventable nosocomial infections and is endemic in hospitals worldwide. The effectiveness of infection control policies varies significantly across hospital settings. The impact of the hospital context towards the rate of nosocomial MRSA infections and the success of infection control is understudied. We conducted a modelling study to evaluate several infection control policies in surgical, intensive care, and medical ward specialties, each with distinct ward conditions and policies, of a tertiary public hospital in Sydney, Australia. We reconfirm hand hygiene as the most successful policy and find it to be necessary for the success of other policies. Active screening for MRSA, patient isolation in single-bed rooms, and additional staffing were found to be less effective. Across these ward specialties, MRSA transmission risk varied by 13% and reductions in the prevalence and nosocomial incidence rate of MRSA due to infection control policies varied by up to 45%. Different levels of infection control were required to reduce and control nosocomial MRSA infections for each ward specialty. Infection control policies and policy targets should be specific for the ward and context of the hospital. The model we developed is generic and can be calibrated to represent different ward settings and pathogens transmitted between patients indirectly through health care workers. This can aid the timely and cost effective design of synergistic and context specific infection control policies.

  10. System and method for determining stator winding resistance in an AC motor

    Science.gov (United States)

    Lu, Bin [Kenosha, WI; Habetler, Thomas G [Snellville, GA; Zhang, Pinjia [Atlanta, GA; Theisen, Peter J [West Bend, WI

    2011-05-31

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  11. The determination of multiple resistance, inheritance and cytochrome P450 activity in bifenthrinresistant Tetranychus urticae Koch (Acari: Tetranychidae)

    OpenAIRE

    AY, Recep; YORULMAZ, Sibel

    2010-01-01

    In this study, multiple resistance, inheritance and cytochrome P450 enzyme activity were determined in Tetranychus urticae Koch (SAK) population after 20 selections for bifenthrin resistance. Selection study and LC50, 60 levels of SAK population of T. urticae were determined by dry film method. LC50 level of the SAK population selected twenty times with bifenthrin was increased from 984.49 to 11914.40 µl l-1 distiled water. Selected population showing 21.84 fold resistances was named ...

  12. Microcontroller based Stator Winding Resistance Determination of Induction Motor Drive on Temperature Variations

    OpenAIRE

    Siraj Ahmed T; Sukhdeo Sao; K.S.R Anjaneyulu

    2014-01-01

    In this paper an experiment has been conducted to determine the online stator winding resistance of an induction motor, in industries as well as domestic purpose induction motors is largely utilized, as it has both applications of variable and constant torque operation nature. The major requirement of an electric drive system is its independent control of torque and speed; this is achieved in DC motor Drive but has more disadvantages. With the help of fast acting switching devices it is possi...

  13. Efficiency determination of resistive plate chambers for fast quasi-monoenergetic neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Roeder, M.; Cowan, T.E.; Kempe, M.; Yakorev, D. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Dresden (Germany); Elekes, Z. [MTA ATOMKI, Debrecen (Hungary); Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Aumann, T.; Caesar, C. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Technische Universitaet Darmstadt, Darmstadt (Germany); Bemmerer, D.; Sobiella, M.; Stach, D.; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Boretzky, K.; Hehner, J.; Heil, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Maroussov, V. [Universitaet zu Koeln, Koeln (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Nusair, O. [GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Al-Balqa Applied University, Salt (Jordan); Prokofiev, A.V. [Uppsala University, The Svedberg Laboratory, Uppsala (Sweden); Reifarth, R. [Johann Wolfgang Goethe - Universitaet, Frankfurt am Main (Germany); Zilges, A. [Universitaet zu Koeln, Koeln (Germany); Zuber, K. [Technische Universitaet Dresden, Dresden (Germany); Collaboration: R3B Collaboration

    2014-07-15

    Composite detectors made of stainless-steel converters and multigap resistive plate chambers have been irradiated with quasi-monoenergetic neutrons with a peak energy of 175 MeV. The neutron detection efficiency has been determined using two different methods. The data are in agreement with the output of Monte Carlo simulations. The simulations are then extended to study the response of a hypothetical array made of these detectors to energetic neutrons from a radioactive ion beam experiment. (orig.)

  14. Determination of Antimicrobial Activity and Resistance to Oxidation of Moringa peregrina Seed Oil

    Directory of Open Access Journals (Sweden)

    Ioanna Chinou

    2012-02-01

    Full Text Available The antimicrobial activity of the oil extracted with n-hexane from the seeds of Moringa peregrina was tested against Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Candida albicans, C. tropicalis and C. glabrata. The oil proved effective against all of the tested microorganisms. Standard antibiotics (netilmycin, 5-flucytocine, intraconazole and 7-amino-4-methylcoumarin-3-acetic acid were used for comparison. The resistance to oxidation of the extracted seed oil was also determined.

  15. Determination of Inorganic Arsenic in a Wide Range of Food Matrices using Hydride Generation - Atomic Absorption Spectrometry.

    Science.gov (United States)

    de la Calle, Maria B; Devesa, Vicenta; Fiamegos, Yiannis; Vélez, Dinoraz

    2017-09-01

    The European Food Safety Authority (EFSA) underlined in its Scientific Opinion on Arsenic in Food that in order to support a sound exposure assessment to inorganic arsenic through diet, information about distribution of arsenic species in various food types must be generated. A method, previously validated in a collaborative trial, has been applied to determine inorganic arsenic in a wide variety of food matrices, covering grains, mushrooms and food of marine origin (31 samples in total). The method is based on detection by flow injection-hydride generation-atomic absorption spectrometry of the iAs selectively extracted into chloroform after digestion of the proteins with concentrated HCl. The method is characterized by a limit of quantification of 10 µg/kg dry weight, which allowed quantification of inorganic arsenic in a large amount of food matrices. Information is provided about performance scores given to results obtained with this method and which were reported by different laboratories in several proficiency tests. The percentage of satisfactory results obtained with the discussed method is higher than that of the results obtained with other analytical approaches.

  16. World-wide and regional intercomparison for the determination of trace elements in tuna fish homogenate sample IAEA-350

    Energy Technology Data Exchange (ETDEWEB)

    Mee, L D; Oregioni, B; Horvat, M [International Atomic Energy Agency, Marine Environment Laboratory, Monaco (Monaco)

    1992-12-01

    The accurate and precise determination of trace elements in marine biological samples is an important aspect of marine pollution studies, especially regarding studies of human exposure to toxic elements through sea food consumption. Past intercomparison studies conducted by the Marine Environment Laboratory of IAEA (formerly the International Laboratory of Marine Radioactivity) have focused upon various marine organisms including fish, bivalves and crustaceans. The present intercalibration exercise was designed in order to satisfy the increased demand for certified reference materials of various origins and the wide range of parameters that should be studied. Additionally, different instrumental techniques, both nuclear and non-nuclear, were compared, and evaluated. By statistically examining the data from this study, the material can be certified for future use as a reference material. The present report presents the entire experimental data set ana a statistical evaluation of the results for each parameter. It should enable individual participants to assess their performance and make appropriate modifications to their laboratory's analytical procedures where necessary. Additionally, a graphical evaluation is made of the data for parameters where a consensus value could not easily be achieved in order to examine the source of any systematic errors. The exercise was designed to satisfy the requirements of participants in IAEA's Analytical Quality Assurance Service as well as laboratories involved in UNEP's Regional Seas Programme and similar activities conducted within the auspices of GIPME (Global Investigations of Pollution in the Marine Environment)

  17. Genome-wide identification and role of MKK and MPK gene families in clubroot resistance of Brassica rapa.

    Science.gov (United States)

    Piao, Yinglan; Jin, Kaining; He, Ying; Liu, Jiaxiu; Liu, Shuang; Li, Xiaonan; Piao, Zhongyun

    2018-01-01

    Mitogen-activated protein kinase (MAPK or MPK) cascades play key roles in responses to various biotic stresses, as well as in plant growth and development. However, the responses of MPK and MPK kinase (MKK) in Chinese cabbage (Brassica rapa ssp. pekinensis) to Plasmodiophora brassicae, a causal agent of clubroot disease in Brassica crops, are still not clear. In the present study, a total of 11 B. rapa MKK (BraMKK) and 30 BraMPK genes were identified and unevenly distributed in 6 and 10 chromosomes, respectively. The synteny analysis indicated that these genes experienced whole-genome triplication and segmental and tandem duplication during or after the divergence of B. rapa, accompanied by the loss of three MKK and two MPK orthologs of Arabidopsis. The BraMKK and BraMPK genes were classified into four groups with similar intron/exon structures and conserved motifs in each group. A quantitative PCR analysis showed that the majority of BraMKK and BraMPK genes were natively expressed in roots, hypocotyls, and leaves, whereas 5 BraMKK and 16 BraMPK genes up-regulated in the roots upon P. brassicae infection. Additionally, these 5 BraMKK and 16 BraMPK genes exhibited a significantly different expression pattern between a pair of clubroot-resistant/susceptible near-isogenic lines (NILs). Furthermore, the possible modules of MKK-MPK involved in B. rapa-P. brassicae interaction are also discussed. The present study will provide functional clues for further characterization of the MAPK cascades in B. rapa.

  18. Implementation of a reference standard and proficiency testing programme by the World Wide Antimalarial Resistance Network (WWARN

    Directory of Open Access Journals (Sweden)

    Barnes Karen I

    2010-12-01

    Full Text Available Abstract Background The Worldwide Antimalarial Resistance Network (WWARN is a global collaboration to support the objective that anyone affected by malaria receives effective and safe drug treatment. The Pharmacology module aims to inform optimal anti-malarial drug selection. There is an urgent need to define the drug exposure - effect relationship for most anti-malarial drugs. Few anti-malarials have had their therapeutic blood concentration levels defined. One of the main challenges in assessing safety and efficacy data in relation to drug concentrations is the comparability of data generated from different laboratories. To explain differences in anti-malarial pharmacokinetics in studies with different measurement laboratories it is necessary to confirm the accuracy of the assay methods. This requires the establishment of an external quality assurance process to assure results that can be compared. This paper describes this process. Methods The pharmacology module of WWARN has established a quality assurance/quality control (QA/QC programme consisting of two separate components: 1. A proficiency testing programme where blank human plasma spiked with certified reference material (CRM in different concentrations is sent out to participating bioanalytical laboratories. 2. A certified reference standard programme where accurately weighed amounts of certified anti-malarial reference standards, metabolites, and internal standards are sent to participating bioanalytical and in vitro laboratories. Conclusion The proficiency testing programme is designed as a cooperative effort to help participating laboratories assess their ability to carry out drug analysis, resolve any potential problem areas and to improve their results - and, in so doing, to improve the quality of anti-malarial pharmacokinetic data published and shared with WWARN. By utilizing the same source of standards for all laboratories, it is possible to minimize bias arising from poor

  19. Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco.

    Science.gov (United States)

    Murgia, Manuela; Bouchrif, Brahim; Timinouni, Mohammed; Al-Qahtani, Ahmed; Al-Ahdal, Mohammed N; Cappuccinelli, Pietro; Rubino, Salvatore; Paglietti, Bianca

    2015-12-23

    Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Isolation and Determination of Antibiotic Resistance Patterns in Nontyphoid Salmonella spp isolated from chicken

    Directory of Open Access Journals (Sweden)

    Seyyedeh Hoorieh Fallah

    2013-01-01

    Full Text Available Background: Salmonellosis is one of the most common food borne diseases in industrial and developing countries. In recent years, an increase in antimicrobial drug resistance, among non-typhoid Salmonella spp has been observed. Objectives: The aim of this study was to isolate and determine antibiotic resistance pattern in non-typhoid Salmonella spp. Materials and Methods: This descriptive study was done on 100 samples of chickens collected from 196 retail markets and was examined for the presence of Salmonella using standard bacteriological procedures and stereotyping kit. Antimicrobial susceptibility testing was performed by disk diffusion methods according to the National Committee for Clinical Laboratory Standards (CLSI. The data were analyzed by using the SPSS software version 18. Result: Forty- four percent of samples were contaminated with Salmonella infection and 56% didn’t have any contamination. The stereotyping results showed that 34 of 44 isolates of Salmonella belonged to Salmonella infantis (79.5 %, one strain (2.3% of group C and 8 strain (18.2% of group D. However, all these strains were sensitive to Cefotaxime and Ciprofloxacin, and 100% were resistant to Nalidixic acid, Tetracyclin and Sterptomycin. The most common resistance pattern (34.1% was towards six antibiotics, and 6.8% of strains were resistant to at least three antibiotics. Conclusion: High levels of resistance to antibiotics that are used commonly for human and poultry can be a warning for our community health and this information must be used to form important strategies for improvement of infection control.

  1. Determination of Insulin Resistance and Beta Cell Function in Healthy Obese and Non-obese Individuals

    International Nuclear Information System (INIS)

    Kazmi, A.; Sattar, A.; Tariq, K. M.; Najamussahar; Hashim, R.; Almani, M. I.

    2013-01-01

    Objective: To determine insulin resistance and beta cell function in healthy obese and nonobese individuals of the local population. Study Design: Case control study. Place and Duration of Study: AFIP Rawalpindi in collaboration with department of medicine military hospital(MH) Rawalpindi, from Aug 2008 to Mar 2009. Methods: Eighty obese(n=40) and non-obese(n=40) subjects were selected by non-probability convenience sampling. Plasma insulin, glucose, and serum total cholestrol were estimated in fasting state. Insulin resistance was calculated by HOMA-IR and beta cell function by HOMA- equation. Results: Significant differences were observed between obese and non-obese individuals regarding insulin resistance, beta cell function, and BMI and serum total cholesterol. Mean insulin resistance in obese group was found to be 11.1 +- 5.1(range 7.0-16.2) and in non-obese group it was 0.9+-0.4 (range 0.5-1.3). This difference was highly significant (p=0.001). There was a highly significant difference between the two groups in term of beta cell function with mean rank 60.1 for obese group and 20.9 non obese groups (Asym sig. 2 tailed 0.000). Also the correlation (r = 0.064) between insulin resistance and beta cell function in obese group is highly significant (p = 0.000). Mean serum leptin levels were lower (6.3 ng/ml) in non-obese, and high (57.2 ng/ml) in the obese group. Conclusions: Insulin resistance is found higher in obese individuals. Beta cell function is significantly different between obese and non-obese groups. (author)

  2. A Novel QTL for Powdery Mildew Resistance in Nordic Spring Barley (Hordeum vulgare L. ssp. vulgare) Revealed by Genome-Wide Association Study.

    Science.gov (United States)

    Bengtsson, Therése; Åhman, Inger; Manninen, Outi; Reitan, Lars; Christerson, Therese; Due Jensen, Jens; Krusell, Lene; Jahoor, Ahmed; Orabi, Jihad

    2017-01-01

    The powdery mildew fungus, Blumeria graminis f. sp. hordei is a worldwide threat to barley ( Hordeum vulgare L. ssp. vulgare ) production. One way to control the disease is by the development and deployment of resistant cultivars. A genome-wide association study was performed in a Nordic spring barley panel consisting of 169 genotypes, to identify marker-trait associations significant for powdery mildew. Powdery mildew was scored during three years (2012-2014) in four different locations within the Nordic region. There were strong correlations between data from all locations and years. In total four QTLs were identified, one located on chromosome 4H in the same region as the previously identified mlo locus and three on chromosome 6H. Out of these three QTLs identified on chromosome 6H, two are in the same region as previously reported QTLs for powdery mildew resistance, whereas one QTL appears to be novel. The top NCBI BLASTn hit of the SNP markers within the novel QTL predicted the responsible gene to be the 26S proteasome regulatory subunit, RPN1, which is required for innate immunity and powdery mildew-induced cell death in Arabidopsis . The results from this study have revealed SNP marker candidates that can be exploited for use in marker-assisted selection and stacking of genes for powdery mildew resistance in barley.

  3. Correlation of proteome-wide changes with social immunity behaviors provides insight into resistance to the parasitic mite, Varroa destructor, in the honey bee (Apis mellifera).

    Science.gov (United States)

    Parker, Robert; Guarna, M Marta; Melathopoulos, Andony P; Moon, Kyung-Mee; White, Rick; Huxter, Elizabeth; Pernal, Stephen F; Foster, Leonard J

    2012-06-29

    Disease is a major factor driving the evolution of many organisms. In honey bees, selection for social behavioral responses is the primary adaptive process facilitating disease resistance. One such process, hygienic behavior, enables bees to resist multiple diseases, including the damaging parasitic mite Varroa destructor. The genetic elements and biochemical factors that drive the expression of these adaptations are currently unknown. Proteomics provides a tool to identify proteins that control behavioral processes, and these proteins can be used as biomarkers to aid identification of disease tolerant colonies. We sampled a large cohort of commercial queen lineages, recording overall mite infestation, hygiene, and the specific hygienic response to V. destructor. We performed proteome-wide correlation analyses in larval integument and adult antennae, identifying several proteins highly predictive of behavior and reduced hive infestation. In the larva, response to wounding was identified as a key adaptive process leading to reduced infestation, and chitin biosynthesis and immune responses appear to represent important disease resistant adaptations. The speed of hygienic behavior may be underpinned by changes in the antenna proteome, and chemosensory and neurological processes could also provide specificity for detection of V. destructor in antennae. Our results provide, for the first time, some insight into how complex behavioural adaptations manifest in the proteome of honey bees. The most important biochemical correlations provide clues as to the underlying molecular mechanisms of social and innate immunity of honey bees. Such changes are indicative of potential divergence in processes controlling the hive-worker maturation.

  4. Determination of response time of resistance thermometers by in situ measurements

    International Nuclear Information System (INIS)

    Goncalves, I.M.P.; Soares, A.J.

    1986-01-01

    The loop-current-step-response test provides a mean for determining the time constant of resistance thermometers. The test consists in heating the sensor a few degrees above ambient temperature by causing a step perurbation in the electric current that flows through the sensor leads. The developed mathematical transformation permits to use data collected during the internal heating transient to predict the sensor response to perturbations in fluid temperature. Experimental data obtained show that time constant determined by this method is within 15 percent of the true value. (Author) [pt

  5. The rarely reported tet(31) tetracycline resistance determinant is common in Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Bager, Ragnhild J.; Ifrah, Dan

    2011-01-01

    The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most pre...... from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida....

  6. Buprofezin susceptibility survey, resistance selection and preliminary determination of the resistance mechanism in Nilaparvata lugens (Homoptera: Delphacidae).

    Science.gov (United States)

    Wang, Yanhua; Gao, Congfen; Xu, Zhiping; Zhu, Yu Cheng; Zhang, Jiushuang; Li, Wenhong; Dai, Dejiang; Lin, Youwei; Zhou, Weijun; Shen, Jinliang

    2008-10-01

    Buprofezin has been used for many years to control Nilaparvata lugens (Stål). Assessment of susceptibility change in the insect is essential for maintaining control efficiency and resistance management. Eleven-year surveys showed that most field populations were susceptible before 2004. However, substantially higher levels of resistance (up to 28-fold) were found in most of the rice fields in China after 2004. A field population was collected and periodically selected for buprofezin resistance in the laboratory. After 65 generations (56 were selected), the colony successfully obtained 3599-fold resistance to buprofezin. Synergism tests showed that O,O-diethyl-O-phenyl phosphorothioate (SV1), piperonyl butoxide (PBO) and diethyl maleate (DEM) increased buprofezin toxicity in the resistant strain by only 1.5-1.6 fold, suggesting that esterases, P450-monooxygenases and glutathione S-transferases had no substantial effect on buprofezin resistance development. The results from this study indicate that N. lugens has the potential to develop high resistance to buprofezin. A resistance management program with rotation of buprofezin and other pesticides may efficiently delay or slow down resistance development in the insect. Further investigation is also necessary to understand the resistance mechanisms in N. lugens.

  7. Metagenomic profiling of microbial composition and antibiotic resistance determinants in Puget Sound.

    Science.gov (United States)

    Port, Jesse A; Wallace, James C; Griffith, William C; Faustman, Elaine M

    2012-01-01

    Human-health relevant impacts on marine ecosystems are increasing on both spatial and temporal scales. Traditional indicators for environmental health monitoring and microbial risk assessment have relied primarily on single species analyses and have provided only limited spatial and temporal information. More high-throughput, broad-scale approaches to evaluate these impacts are therefore needed to provide a platform for informing public health. This study uses shotgun metagenomics to survey the taxonomic composition and antibiotic resistance determinant content of surface water bacterial communities in the Puget Sound estuary. Metagenomic DNA was collected at six sites in Puget Sound in addition to one wastewater treatment plant (WWTP) that discharges into the Sound and pyrosequenced. A total of ~550 Mbp (1.4 million reads) were obtained, 22 Mbp of which could be assembled into contigs. While the taxonomic and resistance determinant profiles across the open Sound samples were similar, unique signatures were identified when comparing these profiles across the open Sound, a nearshore marina and WWTP effluent. The open Sound was dominated by α-Proteobacteria (in particular Rhodobacterales sp.), γ-Proteobacteria and Bacteroidetes while the marina and effluent had increased abundances of Actinobacteria, β-Proteobacteria and Firmicutes. There was a significant increase in the antibiotic resistance gene signal from the open Sound to marina to WWTP effluent, suggestive of a potential link to human impacts. Mobile genetic elements associated with environmental and pathogenic bacteria were also differentially abundant across the samples. This study is the first comparative metagenomic survey of Puget Sound and provides baseline data for further assessments of community composition and antibiotic resistance determinants in the environment using next generation sequencing technologies. In addition, these genomic signals of potential human impact can be used to guide initial

  8. Metagenomic profiling of microbial composition and antibiotic resistance determinants in Puget Sound.

    Directory of Open Access Journals (Sweden)

    Jesse A Port

    Full Text Available Human-health relevant impacts on marine ecosystems are increasing on both spatial and temporal scales. Traditional indicators for environmental health monitoring and microbial risk assessment have relied primarily on single species analyses and have provided only limited spatial and temporal information. More high-throughput, broad-scale approaches to evaluate these impacts are therefore needed to provide a platform for informing public health. This study uses shotgun metagenomics to survey the taxonomic composition and antibiotic resistance determinant content of surface water bacterial communities in the Puget Sound estuary. Metagenomic DNA was collected at six sites in Puget Sound in addition to one wastewater treatment plant (WWTP that discharges into the Sound and pyrosequenced. A total of ~550 Mbp (1.4 million reads were obtained, 22 Mbp of which could be assembled into contigs. While the taxonomic and resistance determinant profiles across the open Sound samples were similar, unique signatures were identified when comparing these profiles across the open Sound, a nearshore marina and WWTP effluent. The open Sound was dominated by α-Proteobacteria (in particular Rhodobacterales sp., γ-Proteobacteria and Bacteroidetes while the marina and effluent had increased abundances of Actinobacteria, β-Proteobacteria and Firmicutes. There was a significant increase in the antibiotic resistance gene signal from the open Sound to marina to WWTP effluent, suggestive of a potential link to human impacts. Mobile genetic elements associated with environmental and pathogenic bacteria were also differentially abundant across the samples. This study is the first comparative metagenomic survey of Puget Sound and provides baseline data for further assessments of community composition and antibiotic resistance determinants in the environment using next generation sequencing technologies. In addition, these genomic signals of potential human impact can be used

  9. Genome-wide association mapping of resistance to eyespot disease (Pseudocercosporella herpotrichoides) in European winter wheat (Triticum aestivum L.) and fine-mapping of Pch1.

    Science.gov (United States)

    Zanke, Christine D; Rodemann, Bernd; Ling, Jie; Muqaddasi, Quddoos H; Plieske, Jörg; Polley, Andreas; Kollers, Sonja; Ebmeyer, Erhard; Korzun, Viktor; Argillier, Odile; Stiewe, Gunther; Zschäckel, Thomas; Ganal, Martin W; Röder, Marion S

    2017-03-01

    Genotypes with recombination events in the Triticum ventricosum introgression on chromosome 7D allowed to fine-map resistance gene Pch1, the main source of eyespot resistance in European winter wheat cultivars. Eyespot (also called Strawbreaker) is a common and serious fungal disease of winter wheat caused by the necrotrophic fungi Oculimacula yallundae and Oculimacula acuformis (former name Pseudocercosporella herpotrichoides). A genome-wide association study (GWAS) for eyespot was performed with 732 microsatellite markers (SSR) and 7761 mapped SNP markers derived from the 90 K iSELECT wheat array using a panel of 168 European winter wheat varieties as well as three spring wheat varieties and phenotypic evaluation of eyespot in field tests in three environments. Best linear unbiased estimations (BLUEs) were calculated across all trials and ranged from 1.20 (most resistant) to 5.73 (most susceptible) with an average value of 4.24 and a heritability of H 2  = 0.91. A total of 108 SSR and 235 SNP marker-trait associations (MTAs) were identified by considering associations with a -log 10 (P value) ≥3.0. Significant MTAs for eyespot-score BLUEs were found on chromosomes 1D, 2A, 2D, 3D, 5A, 5D, 6A, 7A and 7D for the SSR markers and chromosomes 1B, 2A, 2B, 2D, 3B and 7D for the SNP markers. For 18 varieties (10.5%), a highly resistant phenotype was detected that was linked to the presence of the resistance gene Pch1 on chromosome 7D. The identification of genotypes with recombination events in the introgressed genomic segment from Triticum ventricosum harboring the Pch1 resistance gene on chromosome 7DL allowed the fine-mapping of this gene using additional SNP markers and a potential candidate gene Traes_7DL_973A33763 coding for a CC-NBS-LRR class protein was identified.

  10. Antimicrobial resistance determinants in Staphylococcus spp. recovered from birds of prey in Portugal.

    Science.gov (United States)

    Sousa, Margarida; Silva, Nuno; Igrejas, Gilberto; Silva, Filipe; Sargo, Roberto; Alegria, Nuno; Benito, Daniel; Gómez, Paula; Lozano, Carmen; Gómez-Sanz, Elena; Torres, Carmen; Caniça, Manuela; Poeta, Patrícia

    2014-07-16

    Antibiotic resistance among wild animals represent an emerging public health concern. The objective of this study was to analyze the staphylococcal nasal microbiota in birds of prey and their content in antimicrobial resistance determinants. Nasal samples from 16 birds of prey were collected, swabs were dipped and incubated into BHI broth [6.5% NaCl] and later seeded on manitol salt agar and oxacillin-resistance screening agar base media. Staphylococcal colonies were isolated from both media and were identified by biochemical and molecular methods. Susceptibility testing to 18 antimicrobial agents was performed by disk-diffusion method. Six of the 16 tested animals carried staphylococci (37.5%) and 7 isolates of the following species were recovered: Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Staphylococcus sciuri rodentium, Staphylococcus cohnii urealitycum, and Staphylococcus gallinarum. The S. aureus isolate was penicillin-resistant (with blaZ gene) but methicillin-susceptible and was ascribed to spa-type t012, sequence-type ST30 and agr-type III. The S. epidermidis isolate carried blaZ, mecA, mrs(A/B), mphC, tet(K), drfA, and fusC genes, ica operon, and was typed as ST35. The genes ant6'-Ia, tet(K), tet(L), dfrG, cat221, cat194, and cat223 were detected in S. saprophyticus or S. gallinarum isolates. Birds of prey seem to be a natural reservoir of S. aureus and coagulase-negative staphylococci resistant to multiple antibiotics. Due to the convergence between habitats, the contact between wildlife, other animals and humans is now more common and this involves an increased possibility of interchange of these microorganisms in the different ecosystems. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Establishment of a nested-ASP-PCR method to determine the clarithromycin resistance of Helicobacter pylori.

    Science.gov (United States)

    Luo, Xiao-Feng; Jiao, Jian-Hua; Zhang, Wen-Yue; Pu, Han-Ming; Qu, Bao-Jin; Yang, Bing-Ya; Hou, Min; Ji, Min-Jun

    2016-07-07

    To investigate clarithromycin resistance positions 2142, 2143 and 2144 of the 23SrRNA gene in Helicobacter pylori (H. pylori) by nested-allele specific primer-polymerase chain reaction (nested-ASP-PCR). The gastric tissue and saliva samples from 99 patients with positive results of the rapid urease test (RUT) were collected. The nested-ASP-PCR method was carried out with the external primers and inner allele-specific primers corresponding to the reference strain and clinical strains. Thirty gastric tissue and saliva samples were tested to determine the sensitivity of nested-ASP-PCR and ASP-PCR methods. Then, clarithromycin resistance was detected for 99 clinical samples by using different methods, including nested-ASP-PCR, bacterial culture and disk diffusion. The nested-ASP-PCR method was successfully established to test the resistance mutation points 2142, 2143 and 2144 of the 23SrRNA gene of H. pylori. Among 30 samples of gastric tissue and saliva, the H. pylori detection rate of nested-ASP-PCR was 90% and 83.33%, while the detection rate of ASP-PCR was just 63% and 56.67%. Especially in the saliva samples, nested-ASP-PCR showed much higher sensitivity in H. pylori detection and resistance mutation rates than ASP-PCR. In the 99 RUT-positive gastric tissue and saliva samples, the H. pylori-positive detection rate by nested-ASP-PCR was 87 (87.88%) and 67 (67.68%), in which there were 30 wild-type and 57 mutated strains in gastric tissue and 22 wild-type and 45 mutated strains in saliva. Genotype analysis showed that three-points mixed mutations were quite common, but different resistant strains were present in gastric mucosa and saliva. Compared to the high sensitivity shown by nested-ASP-PCR, the positive detection of bacterial culture with gastric tissue samples was 50 cases, in which only 26 drug-resistant strains were found through analyzing minimum inhibitory zone of clarithromycin. The nested-ASP-PCR assay showed higher detection sensitivity than ASP-PCR and

  12. Detection of Hereditary 1,25-Hydroxyvitamin D-Resistant Rickets Caused by Uniparental Disomy of Chromosome 12 Using Genome-Wide Single Nucleotide Polymorphism Array.

    Directory of Open Access Journals (Sweden)

    Mayuko Tamura

    Full Text Available Hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR is an autosomal recessive disease caused by biallelic mutations in the vitamin D receptor (VDR gene. No patients have been reported with uniparental disomy (UPD.Using genome-wide single nucleotide polymorphism (SNP array to confirm whether HVDRR was caused by UPD of chromosome 12.A 2-year-old girl with alopecia and short stature and without any family history of consanguinity was diagnosed with HVDRR by typical laboratory data findings and clinical features of rickets. Sequence analysis of VDR was performed, and the origin of the homozygous mutation was investigated by target SNP sequencing, short tandem repeat analysis, and genome-wide SNP array.The patient had a homozygous p.Arg73Ter nonsense mutation. Her mother was heterozygous for the mutation, but her father was negative. We excluded gross deletion of the father's allele or paternal discordance. Genome-wide SNP array of the family (the patient and her parents showed complete maternal isodisomy of chromosome 12. She was successfully treated with high-dose oral calcium.This is the first report of HVDRR caused by UPD, and the third case of complete UPD of chromosome 12, in the published literature. Genome-wide SNP array was useful for detecting isodisomy and the parental origin of the allele. Comprehensive examination of the homozygous state is essential for accurate genetic counseling of recurrence risk and appropriate monitoring for other chromosome 12 related disorders. Furthermore, oral calcium therapy was effective as an initial treatment for rickets in this instance.

  13. Diversity of Antimicrobial Resistance and Virulence Determinants in Pseudomonas aeruginosa Associated with Fresh Vegetables

    OpenAIRE

    Allydice-Francis, Kashina; Brown, Paul D.

    2012-01-01

    With the increased focus on healthy eating and consuming raw vegetables, this study assessed the extent of contamination of fresh vegetables by Pseudomonas aeruginosa in Jamaica and examined the antibiotic susceptibility profiles and the presence of various virulence associated determinants of P. aeruginosa. Analyses indicated that vegetables from retail markets and supermarkets were widely contaminated by P. aeruginosa; produce from markets were more frequently contaminated, but the differen...

  14. Determination of Germination Response to Temperature and Water Potential for a Wide Range of Cover Crop Species and Related Functional Groups.

    Science.gov (United States)

    Tribouillois, Hélène; Dürr, Carolyne; Demilly, Didier; Wagner, Marie-Hélène; Justes, Eric

    2016-01-01

    A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop

  15. Exploration of a new method in determining the glass transition temperature of BMGs by electrical resistivity

    Science.gov (United States)

    Guo, Jing; Zu, Fangqiu; Chen, Zhihao; Zheng, Shubin; Yuan, Yuan

    2005-07-01

    Based on a brief retrospect of the method in establishing Tg of the bulk metallic glasses (BMGs), some perplexities concerning this are pointed out. With the experimental results of Zr-Al-Ni-Cu-X (Nb,Ti) BMGs, a electrical resistivity method is proposed to determine the glass transition temperature of BMGs. With the method, we define two kinds of characteristic temperature related to the glass transition, Tg-dep and Tg-int, respectively. By comparing Tg-dep and Tg-int with Tg determined by the DSC method, we have found that, for the same alloy at the same heating rate, Tg-dep is very close to Tg-onset while Tg-int is approximate to Tg-mid. As a method to determine the glass transition temperature, the electrical resistivity method has proved to be more convenient and practical in comparison with the DSC method, especially when the DSC curve cannot show the glass transition character of BMGs. In addition, we would emphasize that when we refer to Tg, it is necessary to expatiate on the way of denoting the glass transition temperature, such as Tg-dep or Tg-int ( Tg-onset or Tg-mid), and on the heating rate, in order to avoid ambiguity.

  16. Some Remarks on the Accuracy of Wave Resistance Determination From Wave Measurements along a Parallel Cut

    OpenAIRE

    Moriconi, Alessandro; Lalli, Francesco; Di Felice, Fabio; Esposito, Pier Giorgio; Piscopia, Rodolfo

    1998-01-01

    In the present work some of the main error sources in the wave pattern resistance determination were investigated. The experimental data obtained at the Italian Ship Model Basin (longitudinal wave profiles generated by the steady motion of the Series 60 model and a hard chine Catamaran) were analyzed. It was found that, within the range of Froude numbers tested (.225 ≤ Fr ≤ .345 for the Series 60 and .5 ≤ Fr ≤ 1 for the Catamaran) two sources of uncertainty play a sign...

  17. Determining the fracture resistance of advanced SiC fiber reinforced SiC matrix composites

    International Nuclear Information System (INIS)

    Nozawa, T.; Katoh, Y.; Kishimoto, H.

    2007-01-01

    Full text of publication follows: One of the perceived advantages for highly-crystalline and stoichiometric silicon carbide (SiC) and SiC composites, e.g., advanced SiC fiber reinforced chemically-vapor-infiltrated (CVI) SiC matrix composites, is the retention of fast fracture properties after neutron irradiation at high-temperatures (∼1000 deg. C) to intermediate-doses (∼15 dpa). Accordingly, it has been clarified that the maximum allowable stress (or strain) limit seems unaffected in certain irradiation conditions. Meanwhile, understanding the mechanism of crack propagation from flaws, as potential weakest link to cause composite failure, is somehow lacking, despite that determining the strength criterion based on the fracture mechanics will eventually become important considering the nature of composites' fracture. This study aims to evaluate crack propagation behaviors of advanced SiC/SiC and to provide fundamentals on fracture resistance of the composites to define the strength limit for the practical component design. For those purposes, the effects of irreversible energies related to interfacial de-bonding, fiber bridging, and microcrack forming on the fracture resistance were evaluated. Two-dimensional SiC/SiC composites were fabricated by CVI or nano-infiltration and transient-eutectic-phase (NITE ) methods. Hi-Nicalon TM Type-S or Tyranno TM -SA fibers were used as reinforcements. In-plane mode-I fracture resistance was evaluated by the single edge notched bend technique. The key finding is the continuous Load increase with the crack growth for any types of advanced composites, while many studies specified the gradual load decrease for the conventional composites once the crack initiates. This high quasi-ductility appeared due primarily to high friction (>100 MPa) at the fiber/matrix interface using rough SiC fibers. The preliminary analysis based on the linear elastic fracture mechanics, which does not consider the effects of irreversible energy

  18. Draft Genome Sequence of Neisseria gonorrhoeae Strain NG_869 with Penicillin, Tetracycline and Ciprofloxacin Resistance Determinants Isolated from Malaysia

    OpenAIRE

    Ang, Geik Yong; Yu, Choo Yee; Yong, Delicia Ann; Cheong, Yuet Meng; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae and the increasing reports of multidrug-resistant gonococcal isolates are a global public health care concern. Herein, we report the genome sequence of N. gonorrhoeae strain NG_869 isolated from Malaysia which may provide insights into the drug resistance determinants in gonococcal bacteria.

  19. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    NARCIS (Netherlands)

    Ruiz, Stephanie J.; Schuurman-Wolters, Gea K.; Poolman, Bert

    2016-01-01

    BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s) by which BilE mediates bile resistance are unknown. BilE shares significant sequence

  20. A Laboratory Exercise in Physics: Determining the Resistance of Single Resistors and Series and Parallel Combinations of Resistance.

    Science.gov (United States)

    Schlenker, Richard M.

    Presented is a secondary level physics unit which introduces students to electrical resistance in series and parallel combinations, use of the voltmeter and ammeter, wiring simple circuits, and writing scientific reports. (SL)

  1. Next-Generation Sequencing Approaches in Genome-Wide Discovery of Single Nucleotide Polymorphism Markers Associated with Pungency and Disease Resistance in Pepper.

    Science.gov (United States)

    Manivannan, Abinaya; Kim, Jin-Hee; Yang, Eun-Young; Ahn, Yul-Kyun; Lee, Eun-Su; Choi, Sena; Kim, Do-Sun

    2018-01-01

    Pepper is an economically important horticultural plant that has been widely used for its pungency and spicy taste in worldwide cuisines. Therefore, the domestication of pepper has been carried out since antiquity. Owing to meet the growing demand for pepper with high quality, organoleptic property, nutraceutical contents, and disease tolerance, genomics assisted breeding techniques can be incorporated to develop novel pepper varieties with desired traits. The application of next-generation sequencing (NGS) approaches has reformed the plant breeding technology especially in the area of molecular marker assisted breeding. The availability of genomic information aids in the deeper understanding of several molecular mechanisms behind the vital physiological processes. In addition, the NGS methods facilitate the genome-wide discovery of DNA based markers linked to key genes involved in important biological phenomenon. Among the molecular markers, single nucleotide polymorphism (SNP) indulges various benefits in comparison with other existing DNA based markers. The present review concentrates on the impact of NGS approaches in the discovery of useful SNP markers associated with pungency and disease resistance in pepper. The information provided in the current endeavor can be utilized for the betterment of pepper breeding in future.

  2. Next-Generation Sequencing Approaches in Genome-Wide Discovery of Single Nucleotide Polymorphism Markers Associated with Pungency and Disease Resistance in Pepper

    Directory of Open Access Journals (Sweden)

    Abinaya Manivannan

    2018-01-01

    Full Text Available Pepper is an economically important horticultural plant that has been widely used for its pungency and spicy taste in worldwide cuisines. Therefore, the domestication of pepper has been carried out since antiquity. Owing to meet the growing demand for pepper with high quality, organoleptic property, nutraceutical contents, and disease tolerance, genomics assisted breeding techniques can be incorporated to develop novel pepper varieties with desired traits. The application of next-generation sequencing (NGS approaches has reformed the plant breeding technology especially in the area of molecular marker assisted breeding. The availability of genomic information aids in the deeper understanding of several molecular mechanisms behind the vital physiological processes. In addition, the NGS methods facilitate the genome-wide discovery of DNA based markers linked to key genes involved in important biological phenomenon. Among the molecular markers, single nucleotide polymorphism (SNP indulges various benefits in comparison with other existing DNA based markers. The present review concentrates on the impact of NGS approaches in the discovery of useful SNP markers associated with pungency and disease resistance in pepper. The information provided in the current endeavor can be utilized for the betterment of pepper breeding in future.

  3. Molecular mechanisms of plasmid-determined mercury and cadmium resistances in bacteria

    International Nuclear Information System (INIS)

    Nucifora, G.

    1989-01-01

    The structural basis for induction of the broad spectrum mercurial resistance operon of pDU1358 with inorganic mercury and with phenylmercury acetate was addressed by DNA sequencing analysis (that showed that a major difference occurred in the 3' 29 base pairs of the ital merR gene compared to the merR genes of Tn501 and R100) and by lac-fusion transcription experiments regulated by merR in trans. The lac-fusion results were compared with those from a narrow spectrum operon, and the pDU1358 merR deleted at the 3' end. A hybrid mer operon containing the merR gene from pDU1358 and lacking the merB gene was inducible by both phenylmercury and inorganic Hg 2+ , showing that organomercurial lyase is not needed for induction by organomercurials. A mutant form of pDU1358 merR missing the C-terminal 17 amino acids responded to inorganic Hg 2+ but not to phenylmercury, indicating that the C-terminal region of the MerR protein of the pDU1358 mer operon is required for the recognition of phenylmercury acetate. The down regulation of the mer operon by the merD gene was also measured in trans with complementing mer operons of pDU1358 or R100 or merD - mutants. In the presence of the merD gene, beta-galactosidase activity was lowered by 2 to 4 fold. The merD gene gene product was visualized by autoradiography. The Cd 2+ resistance determinant cadA of S. aureus was investigated. The nucleotide sequence of the DNA fragment containing the cadA determinant revealed two open reading frames the larger one of which is essential for expression of cadmium resistance

  4. Molecular characterization and determination of antimicrobial resistance of Mycoplasma gallisepticum isolated from chickens.

    Science.gov (United States)

    Pakpinyo, Somsak; Sasipreeyajan, Jiroj

    2007-11-15

    In this study, three consecutive approaches of molecular characterization, determination of minimum inhibitory concentration (MIC) and antimicrobial tested on Mycoplasma gallisepticum (MG) isolated from chicken farms were investigated. These approaches were conducted between 2004 and 2005 to 134 MG samples collected from five different regions of the intensive farming area of Thailand. Twenty MG isolates and four reference strains including S6, F, ts-11, and 6/85 were classified according to Random Amplification of Polymorphic DNA (RAPD) patterns prior to the antimicrobial tests. These isolates exhibited 5 different genotypes (A-E). Consequently, MG isolates representing each genotype were tested on 11 registered antibiotics. The levels of MIC were determined. Three antibiotics, doxycycline (0.20 microg/ml), tiamulin (0.10 microg/ml), and tylosin (0.33 microg/ml), gave the least MICs among all effective drugs. Break point comparisons of each antimicrobial suggested that the MG isolates were most sensitive to lincomycin, oxytetracycline, tiamulin, and tylosin. Some MG isolates had an intermediate effect on josamycin and were resistant to enrofloxacin and erythromycin. Our results also indicated that MG isolated and collected from the region and nearby districts had similar RAPD patterns showing properties of antimicrobial resistance. The RAPD patterns may imply the frequent use of antibiotics and a resistant strain of MG. This is the first report of genetic characterization using RAPD reflected by the levels of MIC against MG. The information is useful to plan for prophylactic and therapeutic impacts on the poultry industry especially in the area of intensive use of antibiotics.

  5. Determinants of carriage of resistant Staphylococcus aureus among S. aureus carriers in the Indonesian population inside and outside hospitals

    NARCIS (Netherlands)

    E.S. Lestari (Endang Sri); D.O. Duerink (Offra); U. Hadi (Usman); J.A. Severin (Juliëtte); N.J.D. Nagelkerke (Nico); K. Kuntaman (Kuntaman); H. Wahjono (Hendro); W. Gardjito (Widjoseno); A. Soejoenoes (Ariawan); P. van den Broek (Peterhans); M. Keuter (Monique); I.C. Gyssens (Inge); H.A. Verbrugh (Henri)

    2010-01-01

    textabstractOBJECTIVES: To identify determinants of carriage of resistant Staphylococcus aureus in both hospitalized patients and individuals from the community in two urban centres in Indonesia. METHODS: Staphylococcus aureus cultures and data on recent antibiotic use, demographic, socioeconomic,

  6. DETERMINATION OF THE ISSUE CONCERNING THE LIFT RESISTANCE FACTOR OF LIGHTWEIGHT CAR

    Directory of Open Access Journals (Sweden)

    A. O. Shvets

    2015-10-01

    Full Text Available Purpose. The analytical study of the connection between the longitudinal force, acting on the light-weight car, lateral and vertical forces of interaction in the contact zone «wheel – rail» with the lift resistance factor value is to provide a simple relationships between them. Methodology. Research was conducted by the method of mathematical modeling of loading the freight car when driving at different speeds on straight and curved sections of a track. Findings. Even in the absence of «lift» accordingly the classical train stability theory, as the hinge-rod system, the presence of the longitudinal compressive forces may become a factor provoking cars derailment. The main reason of wheel climbing on rails is the combination of processes of dynamic interaction between the hunting vehicle and the track with simultaneous action of longitudinal compressive forces, and not the destabilization of train as a hingedrod system. To assess the impact of the longitudinal forces value on the lift resistance factor there are presented the calculation results for the empty gondola car motion, model No. 12-532, on 250 m radius curve with 150 mm rise and cross starting of car underframe relating to the track axis in 50 mm guiding section. The calculations were made in such a curve excluding the inertial forces from outstanding acceleration and taking into account the unbalanced acceleration with the permissible speed of 65 km/h. Originality. This study provides the technique of determining the lift resistance factor by longitudinal forces, which is somewhat different from the standard one, as well as evaluates impact of rolling stock speed on this factor. Practical value. The authors clarify the current method of determining the lift resistance factor by longitudinal forces and assess the impact of rolling stock speed on the value of this factor. From these studies one can conclude that because of cars hunting their lift is possible even when the train as

  7. DETERMINATION THE PERMISSIBLE FORCES IN ASSESSING THE LIFT RESISTANT FACTOR OF FREIGHT CARS IN TRAINS

    Directory of Open Access Journals (Sweden)

    A. O. Shvets

    2016-02-01

    Full Text Available Purpose. In the analytical research are considered: 1 relationships between the longitudinal force acting on the car in the train; 2 lateral and vertical forces of interaction in the contact zone «wheel – rail»; 3 dynamic indicators of cars with the magnitude of the car lift resistance factor; 4 obtaining of the dependencies between them. Methodology. The study was conducted by an analytical method assessing the sustainability of the freight car when driving at different speeds on the straight and curved track sections. Findings. In the process of studying the motion of the train, in the investigation of transport events, as well as during the training on the simulator operator, to assess the actions of the driver, the values of the longitudinal forces in the inter car connections are used. To calculate the longitudinal compressive forces, acting on the car, in which car lift resistance factor will be equal to the allowable value (critical force. To assess the impact on the value of the longitudinal force speed, coefficients of the vertical and horizontal dynamics, as well as the wind load on the side surface of the car body are the results of calculations of motion of the empty gondola car, model № 12-532 curve radius of 250 m with a rise of 150 mm and a transverse run of body of car frame relative to the track axis of the guide section 50 mm. Originality. In this study, the technique of determining the longitudinal compressive force was shown, that is somewhat different from the standard. So, as well as assessing the impact on it the speed of rolling coefficients of vertical and horizontal dynamics and wind load on the side surface of the car body. Practical value. The authors developed proposals on the enhancement of existing methods for determining the value of the longitudinal compressive forces acting on the car in which the safety value of the car lift resistance factor will be equal to the allowable value. It will evaluate the

  8. Systematic errors of EIT systems determined by easily-scalable resistive phantoms.

    Science.gov (United States)

    Hahn, G; Just, A; Dittmar, J; Hellige, G

    2008-06-01

    We present a simple method to determine systematic errors that will occur in the measurements by EIT systems. The approach is based on very simple scalable resistive phantoms for EIT systems using a 16 electrode adjacent drive pattern. The output voltage of the phantoms is constant for all combinations of current injection and voltage measurements and the trans-impedance of each phantom is determined by only one component. It can be chosen independently from the input and output impedance, which can be set in order to simulate measurements on the human thorax. Additional serial adapters allow investigation of the influence of the contact impedance at the electrodes on resulting errors. Since real errors depend on the dynamic properties of an EIT system, the following parameters are accessible: crosstalk, the absolute error of each driving/sensing channel and the signal to noise ratio in each channel. Measurements were performed on a Goe-MF II EIT system under four different simulated operational conditions. We found that systematic measurement errors always exceeded the error level of stochastic noise since the Goe-MF II system had been optimized for a sufficient signal to noise ratio but not for accuracy. In time difference imaging and functional EIT (f-EIT) systematic errors are reduced to a minimum by dividing the raw data by reference data. This is not the case in absolute EIT (a-EIT) where the resistivity of the examined object is determined on an absolute scale. We conclude that a reduction of systematic errors has to be one major goal in future system design.

  9. Systematic errors of EIT systems determined by easily-scalable resistive phantoms

    International Nuclear Information System (INIS)

    Hahn, G; Just, A; Dittmar, J; Hellige, G

    2008-01-01

    We present a simple method to determine systematic errors that will occur in the measurements by EIT systems. The approach is based on very simple scalable resistive phantoms for EIT systems using a 16 electrode adjacent drive pattern. The output voltage of the phantoms is constant for all combinations of current injection and voltage measurements and the trans-impedance of each phantom is determined by only one component. It can be chosen independently from the input and output impedance, which can be set in order to simulate measurements on the human thorax. Additional serial adapters allow investigation of the influence of the contact impedance at the electrodes on resulting errors. Since real errors depend on the dynamic properties of an EIT system, the following parameters are accessible: crosstalk, the absolute error of each driving/sensing channel and the signal to noise ratio in each channel. Measurements were performed on a Goe-MF II EIT system under four different simulated operational conditions. We found that systematic measurement errors always exceeded the error level of stochastic noise since the Goe-MF II system had been optimized for a sufficient signal to noise ratio but not for accuracy. In time difference imaging and functional EIT (f-EIT) systematic errors are reduced to a minimum by dividing the raw data by reference data. This is not the case in absolute EIT (a-EIT) where the resistivity of the examined object is determined on an absolute scale. We conclude that a reduction of systematic errors has to be one major goal in future system design

  10. Lysosomes and unfolded protein response, determinants of differential resistance of melanoma cells to vinca alkaloids.

    Science.gov (United States)

    Vincent, Laure-Anais; Attaoua, Chaker; Bellis, Michel; Rozkydalova, Lucie; Hadj-Kaddour, Kamel; Vian, Laurence; Cuq, Pierre

    2015-04-01

    On account of its strong ability to become chemoresistant after a primary response to drugs, malignant melanoma (MM) remains a therapeutic challenge. This study focuses on acquired resistance to vinca alkaloids (VAs) using VA-resistant MM cell lines (CAL1R-VCR, CAL1R-VDS, and CAL1R-VRB), established by long-term continuous exposure of parental CAL1-wt cells to vincristine (VCR), vindesine (VDS), or vinorelbine (VRB), respectively. Transcriptomic profiling using rma and rdam methods led to distinguish two cell groups: CAL1R-VCR and CAL1R-VDS, CAL1R-VRB, and CAL1-wt. mgsa of the specifically altered genes in the first group evidenced the GO terms 'lysosomal lumen' and 'vacuolar lumen' linked to underexpressed genes, and 'endoplasmic reticulum (ER) stress response' associated with overexpressed genes. A specific reduction of lysosomal enzymes, independent of acidic vacuole organelle (AVO) turnover, was observed (LTG probe) in CAL1R-VCR and CAL1R-VDS cells. It was associated with the specific lowering of cathepsin B and L, known to be involved in the lysosomal pathway of apoptosis. Confirming gene profiling, the same groups (CAL1R-VCR and CAL1R-VDS, CAL1-wt and CAL1R-VRB) could be distinguished regarding the VA-mediated changes on mean size areas and on acidic compartment volumes. These two parameters were reduced in CAL1R-VCR and CAL1R-VDS cells, suggesting a smaller AVO accumulation and thus a reduced sensitivity to lysosomal membrane permeabilization-mediated apoptosis. In addition, 'ER stress response' inhibition by tauroursodeoxycholic acid induced a higher VA sensitization of the first cell group. In conclusion, lysosomes and unfolded protein response could be key determinants of the differential resistance of MM to VAs. © 2015 Société Française de Pharmacologie et de Thérapeutique.

  11. A genome-wide identification of chromosomal regions determining nitrogen use efficiency components in wheat (Triticum aestivum L.).

    Science.gov (United States)

    Cormier, Fabien; Le Gouis, Jacques; Dubreuil, Pierre; Lafarge, Stéphane; Praud, Sébastien

    2014-12-01

    This study identified 333 genomic regions associated to 28 traits related to nitrogen use efficiency in European winter wheat using genome-wide association in a 214-varieties panel experimented in eight environments. Improving nitrogen use efficiency is a key factor to sustainably ensure global production increase. However, while high-throughput screening methods remain at a developmental stage, genetic progress may be mainly driven by marker-assisted selection. The objective of this study was to identify chromosomal regions associated with nitrogen use efficiency-related traits in bread wheat (Triticum aestivum L.) using a genome-wide association approach. Two hundred and fourteen European elite varieties were characterised for 28 traits related to nitrogen use efficiency in eight environments in which two different nitrogen fertilisation levels were tested. The genome-wide association study was carried out using 23,603 SNP with a mixed model for taking into account parentage relationships among varieties. We identified 1,010 significantly associated SNP which defined 333 chromosomal regions associated with at least one trait and found colocalisations for 39 % of these chromosomal regions. A method based on linkage disequilibrium to define the associated region was suggested and discussed with reference to false positive rate. Through a network approach, colocalisations were analysed and highlighted the impact of genomic regions controlling nitrogen status at flowering, precocity, and nitrogen utilisation on global agronomic performance. We were able to explain 40 ± 10 % of the total genetic variation. Numerous colocalisations with previously published genomic regions were observed with such candidate genes as Ppd-D1, Rht-D1, NADH-Gogat, and GSe. We highlighted selection pressure on yield and nitrogen utilisation discussing allele frequencies in associated regions.

  12. Genome-wide DNA methylation maps in follicular lymphoma cells determined by methylation-enriched bisulfite sequencing.

    Directory of Open Access Journals (Sweden)

    Jeong-Hyeon Choi

    Full Text Available BACKGROUND: Follicular lymphoma (FL is a form of non-Hodgkin's lymphoma (NHL that arises from germinal center (GC B-cells. Despite the significant advances in immunotherapy, FL is still not curable. Beyond transcriptional profiling and genomics datasets, there currently is no epigenome-scale dataset or integrative biology approach that can adequately model this disease and therefore identify novel mechanisms and targets for successful prevention and treatment of FL. METHODOLOGY/PRINCIPAL FINDINGS: We performed methylation-enriched genome-wide bisulfite sequencing of FL cells and normal CD19(+ B-cells using 454 sequencing technology. The methylated DNA fragments were enriched with methyl-binding proteins, treated with bisulfite, and sequenced using the Roche-454 GS FLX sequencer. The total number of bases covered in the human genome was 18.2 and 49.3 million including 726,003 and 1.3 million CpGs in FL and CD19(+ B-cells, respectively. 11,971 and 7,882 methylated regions of interest (MRIs were identified respectively. The genome-wide distribution of these MRIs displayed significant differences between FL and normal B-cells. A reverse trend in the distribution of MRIs between the promoter and the gene body was observed in FL and CD19(+ B-cells. The MRIs identified in FL cells also correlated well with transcriptomic data and ChIP-on-Chip analyses of genome-wide histone modifications such as tri-methyl-H3K27, and tri-methyl-H3K4, indicating a concerted epigenetic alteration in FL cells. CONCLUSIONS/SIGNIFICANCE: This study is the first to provide a large scale and comprehensive analysis of the DNA methylation sequence composition and distribution in the FL epigenome. These integrated approaches have led to the discovery of novel and frequent targets of aberrant epigenetic alterations. The genome-wide bisulfite sequencing approach developed here can be a useful tool for profiling DNA methylation in clinical samples.

  13. Automated systems in the identification and determination of methicillin resistance among coagulase negative staphylococci

    Directory of Open Access Journals (Sweden)

    Juliana Caierão

    2006-05-01

    Full Text Available Coagulase-negative staphylococci (CoNS are an important cause of nosocomial bacteremia, specially in patients with indwelling devices or those submitted to invasive medical procedures. The identification of species and the accurate and rapid detection of methicillin resistance are directly dependent on the quality of the identification and susceptibility tests used, either manual or automated. The objective of this study was to evaluate the accuracy of two automated systems MicroScan and Vitek - in the identification of CoNS species and determination of susceptibility to methicillin, considering as gold standard the biochemical tests and the characterization of the mecA gene by polymerase chain reaction, respectively. MicroScan presented better results in the identification of CoNS species (accuracy of 96.8 vs 78.8%, respectively; isolates from the following species had no precise identification: Staphylococcus haemolyticus, S. simulans, and S. capitis. Both systems were similar in the characterization of methicillin resistance. The higher discrepancies for gene mec detection were observed among species other than S. epidermidis (S. hominis, S. saprophyticus, S. sciuri, S. haemolyticus, S. warneri, S. cohnii, and those with borderline MICs.

  14. A proposed analytic framework for determining the impact of an antimicrobial resistance intervention.

    Science.gov (United States)

    Grohn, Yrjo T; Carson, Carolee; Lanzas, Cristina; Pullum, Laura; Stanhope, Michael; Volkova, Victoriya

    2017-06-01

    Antimicrobial use (AMU) is increasingly threatened by antimicrobial resistance (AMR). The FDA is implementing risk mitigation measures promoting prudent AMU in food animals. Their evaluation is crucial: the AMU/AMR relationship is complex; a suitable framework to analyze interventions is unavailable. Systems science analysis, depicting variables and their associations, would help integrate mathematics/epidemiology to evaluate the relationship. This would identify informative data and models to evaluate interventions. This National Institute for Mathematical and Biological Synthesis AMR Working Group's report proposes a system framework to address the methodological gap linking livestock AMU and AMR in foodborne bacteria. It could evaluate how AMU (and interventions) impact AMR. We will evaluate pharmacokinetic/dynamic modeling techniques for projecting AMR selection pressure on enteric bacteria. We study two methods to model phenotypic AMR changes in bacteria in the food supply and evolutionary genotypic analyses determining molecular changes in phenotypic AMR. Systems science analysis integrates the methods, showing how resistance in the food supply is explained by AMU and concurrent factors influencing the whole system. This process is updated with data and techniques to improve prediction and inform improvements for AMU/AMR surveillance. Our proposed framework reflects both the AMR system's complexity, and desire for simple, reliable conclusions.

  15. Molecular Characterization of Copper and Cadmium Resistance Determinants in the Biomining Thermoacidophilic Archaeon Sulfolobus metallicus

    Directory of Open Access Journals (Sweden)

    Alvaro Orell

    2013-01-01

    Full Text Available Sulfolobus metallicus is a thermoacidophilic crenarchaeon used in high-temperature bioleaching processes that is able to grow under stressing conditions such as high concentrations of heavy metals. Nevertheless, the genetic and biochemical mechanisms responsible for heavy metal resistance in S. metallicus remain uncharacterized. Proteomic analysis of S. metallicus cells exposed to 100 mM Cu revealed that 18 out of 30 upregulated proteins are related to the production and conversion of energy, amino acids biosynthesis, and stress responses. Ten of these last proteins were also up-regulated in S. metallicus treated in the presence of 1 mM Cd suggesting that at least in part, a common general response to these two heavy metals. The S. metallicus genome contained two complete cop gene clusters, each encoding a metallochaperone (CopM, a Cu-exporting ATPase (CopA, and a transcriptional regulator (CopT. Transcriptional expression analysis revealed that copM and copA from each cop gene cluster were cotranscribed and their transcript levels increased when S. metallicus was grown either in the presence of Cu or using chalcopyrite (CuFeS2 as oxidizable substrate. This study shows for the first time the presence of a duplicated version of the cop gene cluster in Archaea and characterizes some of the Cu and Cd resistance determinants in a thermophilic archaeon employed for industrial biomining.

  16. Glucocorticoid and cytokine crosstalk: Feedback, feedforward, and co-regulatory interactions determine repression or resistance.

    Science.gov (United States)

    Newton, Robert; Shah, Suharsh; Altonsy, Mohammed O; Gerber, Antony N

    2017-04-28

    Inflammatory signals induce feedback and feedforward systems that provide temporal control. Although glucocorticoids can repress inflammatory gene expression, glucocorticoid receptor recruitment increases expression of negative feedback and feedforward regulators, including the phosphatase, DUSP1, the ubiquitin-modifying enzyme, TNFAIP3, or the mRNA-destabilizing protein, ZFP36. Moreover, glucocorticoid receptor cooperativity with factors, including nuclear factor-κB (NF-κB), may enhance regulator expression to promote repression. Conversely, MAPKs, which are inhibited by glucocorticoids, provide feedforward control to limit expression of the transcription factor IRF1, and the chemokine, CXCL10. We propose that modulation of feedback and feedforward control can determine repression or resistance of inflammatory gene expression toglucocorticoid. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Determination of the resistance to tensile fracture of refractory mixtures of gunite

    International Nuclear Information System (INIS)

    Gomez Sanchez, A; Tomba Martinez, A.G

    2004-01-01

    The determination of the mechanical properties of cooled refractory mixtures is useful since it allows the materials to be compared for the purposes of selection and reports on their degree of internal cohesion, green or calcination, so that their structural ability can be estimated, especially during installation. Given the testing difficulties originating in the fragility of the ceramic materials, the tension test is not generally used in refractories. However, ASTM C-307 94 determines the tensile strength of cured chemical-resistant materials, for which this work considered the possibility of testing cement-based monolithic refractories in this non conventional condition. The tensile resistance to the fracture of three different refractory mixtures (A, B 1 and B 2 ), used in heat repairing by gunite in coking ovens, that were characterized by chemical, granulometric, and mineralogical analysis pycnometric density measurements. The pieces for the tests ('bone' type: length = 75 mm, maximum width = 40 mm, minimum width = 25 mm, thickness = 10 - 25 mm) were prepared by ramming of mixtures of material/water in a metallic mold; they were sinterized (1200 o C, 1h) and characterized by measures of bulk density, porosity and observation of the surface texture, in green and calcinated. The tensile tests, based on ASTM C-307 94, were performed in an Instron model 4467 machine in open air, at room temperature and position control (0.5 mm/min). The following values were obtained, in kPa: AW347±308; B 1 W738±130; B 2 W604±64. These values were lower than those for the tensile fracture module (MOR), although they displayed an equivalent order: A≤B 2 ≤B 1 . This was related to the characteristics of each refractory mixture and at the end of the pieces tested (CW)

  18. Distribution of extended-spectrum cephalosporin resistance determinants in Salmonella enterica and Escherichia coli isolated from broilers in southern Japan.

    Science.gov (United States)

    Shahada, F; Chuma, T; Kosugi, G; Kusumoto, M; Iwata, T; Akiba, M

    2013-06-01

    This study was conducted to investigate the distribution and diversity of extended-spectrum cephalosporin (ESC) resistance determinants in Salmonella enterica and Escherichia coli obtained from the same cecal samples and to provide evidence of transmission of the resistance determinants among these bacteria in broiler farms in southern Japan. Salmonella enterica and E. coli were characterized by serotyping and multilocus sequence typing, respectively. An antimicrobial susceptibility test, plasmid analysis, and identification and localization of resistance genes were performed to determine the relatedness of ESC resistance determinants among the isolates. Of 48 flocks examined, 14 had S. enterica. In total, 57 S. enterica isolates were obtained, 45 of which showed ESC resistance. Extended-spectrum cephalosporin-resistant E. coli were also obtained from all of these ESC-resistant Salmonella-positive samples. β-Lactamase genes, blaTEM-52 (38 isolates), blaCTX-M-14 (1 isolate), and blaCMY-2 (6 isolates), were carried by conjugative untypable or IncP plasmids detected in the S. enterica serovars Infantis and Manhattan. The β-lactamase genes blaCTX-M-14 (3 isolates), blaCTX-M-15 (3 isolates), blaSHV-2 (1 isolate), blaSHV-12 (2 isolates), and blaCMY-2 (32 isolates) associated with IncI1-Iγ, IncFIB, IncFIC, IncK, IncB/O, and IncY plasmids were detected in E. coli co-isolates. Restriction mapping revealed similar plasmids in Salmonella Infantis and Salmonella Manhattan and in different sequence types of E. coli. Intraspecies transmission of plasmids was suggested within S. enterica and E. coli populations, whereas interspecies transmission was not observed. This study highlights the importance of plasmids as carriers of ESC resistance determinants.

  19. Cloning and DNA sequence of the mercuric- and organomercurial-resistance determinants of plasmid pDU1358

    International Nuclear Information System (INIS)

    Griffin, H.G.; Foster, T.J.; Silver, S.; Misra, T.K.

    1987-01-01

    The broad-spectrum mercurial-resistance plasmid pDU1358 was analyzed by cloning the resistance determinants and preparing a physical and genetic map of a 45-kilobase (kb) region of the plasmid that contains two separate mercurial-resistance operons that mapped about 20 kb apart. One encoded narrow-spectrum mercurial resistance to Hg 2+ and a few organomercurials; the other specified broad-spectrum resistance to phenylmercury and additional organomercurials. Each determinant governed mercurial transport functions. Southern DNA x DNA hybridization experiments using gene-specific probes from the plasmid R100 mer operon indicated close homology with the R100 deteminant. The 2153 base pairs of the promoter-distal part of the broad-spectrum Hg 2+ -resistance operon of pDU1358 were sequenced. This region included the 3'-terminal part of the merA gene, merD, unidentified reading frame URF1, and a part of URF2 homologous to previously sequenced determinants of plasmid R100. Between the merA and merD genes, an open reading frame encoding a 212 amino acid polypeptide was identified as the merB gene that determines the enzyme organomercurial lyase that cleaves the C-Hg bond of phenylmercury

  20. A State-Wide Survey of South Australian Secondary Schools to Determine the Current Emphasis on Ergonomics and Computer Use

    Science.gov (United States)

    Sawyer, Janet; Penman, Joy

    2012-01-01

    This study investigated the pattern of teaching of healthy computing skills to high school students in South Australia. A survey approach was used to collect data, specifically to determine the emphasis placed by schools on ergonomics that relate to computer use. Participating schools were recruited through the Department for Education and Child…

  1. Improved annotation of antibiotic resistance determinants reveals microbial resistomes cluster by ecology

    OpenAIRE

    Gibson, Molly K; Forsberg, Kevin J; Dantas, Gautam

    2014-01-01

    Antibiotic resistance is a dire clinical problem with important ecological dimensions. While antibiotic resistance in human pathogens continues to rise at alarming rates, the impact of environmental resistance on human health is still unclear. To investigate the relationship between human-associated and environmental resistomes, we analyzed functional metagenomic selections for resistance against 18 clinically relevant antibiotics from soil and human gut microbiota as well as a set of multidr...

  2. Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Guardabassi, L.

    2005-01-01

    A novel tetracycline resistance determinant named Tet 39 was found in unrelated Acinetobacter strains isolated from freshwater trout farms (n=4) and sewage (n=6) in Denmark, and from a clinical specimen in the Netherlands (n=1). The determinant was located on transferable plasmids and consisted o...

  3. Prevalence and determinants of fecal colonization with vancomycin-resistant Enterococcus in hospitalized patients in The Netherlands

    NARCIS (Netherlands)

    van den Braak, N.; Ott, A.; van Belkum, A.; Kluytmans, J. A.; Koeleman, J. G.; Spanjaard, L.; Voss, A.; Weersink, A. J.; Vandenbroucke-Grauls, C. M.; Buiting, A. G.; Verbrugh, H. A.; Endtz, H. P.

    2000-01-01

    To determine the prevalence and determinants of fecal carriage of vancomycin-resistant enterococci (VRE) in intensive care unit (ICU), hematology-oncology, and hemodialysis patients in The Netherlands. Descriptive, multicenter study, with yearly 1-week point-prevalence assessments between 1995 and

  4. Contact-free sheet resistance determination of large area graphene layers by an open dielectric loaded microwave cavity

    International Nuclear Information System (INIS)

    Shaforost, O.; Wang, K.; Adabi, M.; Guo, Z.; Hanham, S.; Klein, N.; Goniszewski, S.; Gallop, J.; Hao, L.

    2015-01-01

    A method for contact-free determination of the sheet resistance of large-area and arbitrary shaped wafers or sheets coated with graphene and other (semi) conducting ultrathin layers is described, which is based on an open dielectric loaded microwave cavity. The sample under test is exposed to the evanescent resonant field outside the cavity. A comparison with a closed cavity configuration revealed that radiation losses have no significant influence of the experimental results. Moreover, the microwave sheet resistance results show good agreement with the dc conductivity determined by four-probe van der Pauw measurements on a set of CVD samples transferred on quartz. As an example of a practical application, correlations between the sheet resistance and deposition conditions for CVD graphene transferred on quartz wafers are described. Our method has a high potential as measurement standard for contact-free sheet resistance measurement and mapping of large area graphene samples

  5. Genetically Determined Insulin Resistance is Characterized by Down-Regulation of Mitochondrial Oxidative Metabolism in Human Skeletal Muscle

    DEFF Research Database (Denmark)

    Kristensen, Jonas M; Skov, Vibe; Wojtaszewski, Jørgen

    2010-01-01

    Transcriptional profiling of skeletal muscle from patients with type 2 diabetes and high-risk individuals have demonstrated a co-ordinated down-regulation of oxidative phosphorylation (OxPhos) genes, suggesting a link between insulin resistance and mitochondrial dysfunction. However, whether...... mitochondrial dysfunction is a cause or consequence of insulin resistance remains to be clarified. In the present study, we tested the hypothesis that mitochondrial oxidative metabolism was down-regulated in skeletal muscle of patients with genetically determined insulin resistance. Skeletal muscle biopsies.......02), and complex V (ATP5B; p=0.005). Our data demonstrate that genetically determined insulin resistance is associated with a co-ordinated down-regulation of OxPhos components both at the transcriptional and translational level. These findings suggest that an impaired biological response to insulin in skeletal...

  6. Determining the bounds of skilful forecast range for probabilistic prediction of system-wide wind power generation

    Directory of Open Access Journals (Sweden)

    Dirk Cannon

    2017-06-01

    Full Text Available State-of-the-art wind power forecasts beyond a few hours ahead rely on global numerical weather prediction models to forecast the future large-scale atmospheric state. Often they provide initial and boundary conditions for nested high resolution simulations. In this paper, both upper and lower bounds on forecast range are identified within which global ensemble forecasts provide skilful information for system-wide wind power applications. An upper bound on forecast range is associated with the limit of predictability, beyond which forecasts have no more skill than predictions based on climatological statistics. A lower bound is defined at the lead time beyond which the resolved uncertainty associated with estimating the future large-scale atmospheric state is larger than the unresolved uncertainty associated with estimating the system-wide wind power response to a given large-scale state.The bounds of skilful ensemble forecast range are quantified for three leading global forecast systems. The power system of Great Britain (GB is used as an example because independent verifying data is available from National Grid. The upper bound defined by forecasts of GB-total wind power generation at a specific point in time is found to be 6–8 days. The lower bound is found to be 1.4–2.4 days. Both bounds depend on the global forecast system and vary seasonally. In addition, forecasts of the probability of an extreme power ramp event were found to possess a shorter limit of predictability (4.5–5.5 days. The upper bound on this forecast range can only be extended by improving the global forecast system (outside the control of most users or by changing the metric used in the probability forecast. Improved downscaling and microscale modelling of the wind farm response may act to decrease the lower bound. The potential gain from such improvements have diminishing returns beyond the short-range (out to around 2 days.

  7. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    OpenAIRE

    Stephanie J. Ruiz; Gea K. Schuurman-Wolters; Bert Poolman

    2016-01-01

    BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s) by which BilE mediates bile resistance are unknown. BilE shares significant sequence similarity with ATP-binding cassette (ABC) importers that contribute to virulence and stress responses by importing quaternary ammonium compounds that act as compatible solutes. Assays using related co...

  8. Adiponectin expression in visceral adiposity is an important determinant of insulin resistance in morbid obesity.

    Science.gov (United States)

    Sirbu, Anca Elena; Buburuzan, Laura; Kevorkian, Steliana; Martin, Sorina; Barbu, Carmen; Copaescu, Catalin; Smeu, Bogdan; Fica, Simona

    2018-04-12

    Visceral adiposity is associated with decreased serum adiponectin levels, peripheral resistance to insulin and an increased risk of cardio-metabolic complications. However, the link between adiponectin expression in visceral adipose tissue (VAT), its serum levels and metabolic protection is controversial. The aim of this study was to investigate the relationship between the adiponectin gene expression in VAT and clinical and metabolic parameters in patients with severe obesity. This is a cross-sectional study that included 51 severely obese patients (age 43.24±11.29 years, BMI 45.13±8.67 kg/m2), extensively evaluated clinically and biologically (metabolic tests, serum adiponectin measurements, HOMA-IR) before bariatric surgery. Omental adipose tissue was sampled during the intervention and the relative quantification of adiponectin gene expression was performed by real-time PCR, using beta-actin as reference gene. Adiponectin mRNA in VAT was significantly higher in obese insulin-sensitive patients than in the rest of obese patients (p<0.05) and negatively correlated with HOMA-IR (r =-0.354, p=0.016) and uric acid (r =-0.304, p=0.045). After adjustment for gender, TG/HDL ratio and uric acid, adiponectin expresion (β= -0.439, p=0.001), waist circumference (β=0.467, p=0.001) and serum adiponectin (β =-0.339, p=0.011) remained significantly associated with HOMA-IR, together explaining more than 50% of its variation. In severely obese patients, adiponectin gene expression in VAT is negatively correlated with serum levels of uric acid and is an independent determinant, together with anthropometric parameters of visceral obesity and serum adiponectin levels, of insulin resistance.

  9. Solid oxide fuel cell cathode infiltrate particle size control and oxygen surface exchange resistance determination

    Science.gov (United States)

    Burye, Theodore E.

    Over the past decade, nano-sized Mixed Ionic Electronic Conducting (MIEC) -- micro-sized Ionic Conducting (IC) composite cathodes produced by the infiltration method have received much attention in the literature due to their low polarization resistance (RP) at intermediate (500-700°C) operating temperatures. Small infiltrated MIEC oxide nano-particle size and low intrinsic MIEC oxygen surface exchange resistance (Rs) have been two critical factors allowing these Nano-Micro-Composite Cathodes (NMCCs) to achieve high performance and/or low temperature operation. Unfortunately, previous studies have not found a reliable method to control or reduce infiltrated nano-particle size. In addition, controversy exists on the best MIEC infiltrate composition because: 1) Rs measurements on infiltrated MIEC particles are presently unavailable in the literature, and 2) bulk and thin film Rs measurements on nominally identical MIEC compositions often vary by up to 3 orders of magnitude. Here, two processing techniques, precursor nitrate solution desiccation and ceria oxide pre-infiltration, were developed to systematically produce a reduction in the average La0.6Sr0.4Co0.8Fe 0.2O3-delta (LSCF) infiltrated nano-particle size from 50 nm to 22 nm. This particle size reduction reduced the SOFC operating temperature, (defined as the temperature where RP=0.1 Ocm 2) from 650°C to 540°C. In addition, Rs values for infiltrated MIEC particles were determined for the first time through finite element modeling calculations on 3D Focused Ion Beam-Scanning Electron Microscope (FIB-SEM) reconstructions of electrochemically characterized infiltrated electrodes.

  10. A genome-wide association study identifies rs2000999 as a strong genetic determinant of circulating haptoglobin levels.

    Directory of Open Access Journals (Sweden)

    Philippe Froguel

    Full Text Available Haptoglobin is an acute phase inflammatory marker. Its main function is to bind hemoglobin released from erythrocytes to aid its elimination, and thereby haptoglobin prevents the generation of reactive oxygen species in the blood. Haptoglobin levels have been repeatedly associated with a variety of inflammation-linked infectious and non-infectious diseases, including malaria, tuberculosis, human immunodeficiency virus, hepatitis C, diabetes, carotid atherosclerosis, and acute myocardial infarction. However, a comprehensive genetic assessment of the inter-individual variability of circulating haptoglobin levels has not been conducted so far.We used a genome-wide association study initially conducted in 631 French children followed by a replication in three additional European sample sets and we identified a common single nucleotide polymorphism (SNP, rs2000999 located in the Haptoglobin gene (HP as a strong genetic predictor of circulating Haptoglobin levels (P(overall = 8.1 × 10(-59, explaining 45.4% of its genetic variability (11.8% of Hp global variance. The functional relevance of rs2000999 was further demonstrated by its specific association with HP mRNA levels (β = 0.23 ± 0.08, P = 0.007. Finally, SNP rs2000999 was associated with decreased total and low-density lipoprotein cholesterol in 8,789 European children (P(total cholesterol = 0.002 and P(LDL = 0.0008.Given the central position of haptoglobin in many inflammation-related metabolic pathways, the relevance of rs2000999 genotyping when evaluating haptoglobin concentration should be further investigated in order to improve its diagnostic/therapeutic and/or prevention impact.

  11. Genetic Architecture of Aluminum Tolerance in Rice (Oryza sativa) Determined through Genome-Wide Association Analysis and QTL Mapping

    Science.gov (United States)

    Famoso, Adam N.; Zhao, Keyan; Clark, Randy T.; Tung, Chih-Wei; Wright, Mark H.; Bustamante, Carlos; Kochian, Leon V.; McCouch, Susan R.

    2011-01-01

    Aluminum (Al) toxicity is a primary limitation to crop productivity on acid soils, and rice has been demonstrated to be significantly more Al tolerant than other cereal crops. However, the mechanisms of rice Al tolerance are largely unknown, and no genes underlying natural variation have been reported. We screened 383 diverse rice accessions, conducted a genome-wide association (GWA) study, and conducted QTL mapping in two bi-parental populations using three estimates of Al tolerance based on root growth. Subpopulation structure explained 57% of the phenotypic variation, and the mean Al tolerance in Japonica was twice that of Indica. Forty-eight regions associated with Al tolerance were identified by GWA analysis, most of which were subpopulation-specific. Four of these regions co-localized with a priori candidate genes, and two highly significant regions co-localized with previously identified QTLs. Three regions corresponding to induced Al-sensitive rice mutants (ART1, STAR2, Nrat1) were identified through bi-parental QTL mapping or GWA to be involved in natural variation for Al tolerance. Haplotype analysis around the Nrat1 gene identified susceptible and tolerant haplotypes explaining 40% of the Al tolerance variation within the aus subpopulation, and sequence analysis of Nrat1 identified a trio of non-synonymous mutations predictive of Al sensitivity in our diversity panel. GWA analysis discovered more phenotype–genotype associations and provided higher resolution, but QTL mapping identified critical rare and/or subpopulation-specific alleles not detected by GWA analysis. Mapping using Indica/Japonica populations identified QTLs associated with transgressive variation where alleles from a susceptible aus or indica parent enhanced Al tolerance in a tolerant Japonica background. This work supports the hypothesis that selectively introgressing alleles across subpopulations is an efficient approach for trait enhancement in plant breeding programs and

  12. Biofilm plasmids with a rhamnose operon are widely distributed determinants of the 'swim-or-stick' lifestyle in roseobacters.

    Science.gov (United States)

    Michael, Victoria; Frank, Oliver; Bartling, Pascal; Scheuner, Carmen; Göker, Markus; Brinkmann, Henner; Petersen, Jörn

    2016-10-01

    Alphaproteobacteria of the metabolically versatile Roseobacter group (Rhodobacteraceae) are abundant in marine ecosystems and represent dominant primary colonizers of submerged surfaces. Motility and attachment are the prerequisite for the characteristic 'swim-or-stick' lifestyle of many representatives such as Phaeobacter inhibens DSM 17395. It has recently been shown that plasmid curing of its 65-kb RepA-I-type replicon with >20 genes for exopolysaccharide biosynthesis including a rhamnose operon results in nearly complete loss of motility and biofilm formation. The current study is based on the assumption that homologous biofilm plasmids are widely distributed. We analyzed 33 roseobacters that represent the phylogenetic diversity of this lineage and documented attachment as well as swimming motility for 60% of the strains. All strong biofilm formers were also motile, which is in agreement with the proposed mechanism of surface attachment. We established transposon mutants for the four genes of the rhamnose operon from P. inhibens and proved its crucial role in biofilm formation. In the Roseobacter group, two-thirds of the predicted biofilm plasmids represent the RepA-I type and their physiological role was experimentally validated via plasmid curing for four additional strains. Horizontal transfer of these replicons was documented by a comparison of the RepA-I phylogeny with the species tree. A gene content analysis of 35 RepA-I plasmids revealed a core set of genes, including the rhamnose operon and a specific ABC transporter for polysaccharide export. Taken together, our data show that RepA-I-type biofilm plasmids are essential for the sessile mode of life in the majority of cultivated roseobacters.

  13. World-wide intercomparison exercise for the determination of trace elements in Fucus sample IAEA-140. Report no. 64

    International Nuclear Information System (INIS)

    Coquery, M.; Carvalho, F.P.; Horvat, M.; Azemard, S.

    1997-09-01

    The accurate and precise determination of trace elements in marine samples is fundamental to pollution assessment in coastal and marine environments. Analyses of sea plants are important to investigate the uptake of toxic elements along the trophic chain and sea plants may be used as indicators for water pollution and to compare the levels of contamination of different aquatic environments. IAEA. together with UNEP and the Intergovernmental Oceanographic Commission (IOC) work closely with other producers of Reference Materials in order to assure a continuous supply of these vital compounds for quality assurance procedures. A full catalogue of materials is published regularly. The Marine Environmental Studies Laboratory (MESL) of IAEA-MEL has conducted intercomparison exercises on trace elements for over twenty years as part of its contribution to IAEA's Analytical Quality Control Service, UNEP's Regional Seas Programme. and, occasionally, in association with the IOC GIPME (Global Investigation of the Pollution in the Marine Environment) programme. This report describes the performance of laboratories in one intercomparison run conducted during 1996 that was organized for the determination of trace elements in a marine macro algae (Fucus sp.) sample. This study was intended to give laboratories responsible for trace element analyses of marine materials an opportunity for checking their analytical performance

  14. Sharing individual patient and parasite-level data through the WorldWide Antimalarial Resistance Network platform: A qualitative case study [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Elizabeth Pisani

    2017-08-01

    Full Text Available Background: Increasingly, biomedical researchers are encouraged or required by research funders and journals to share their data, but there's very little guidance on how to do that equitably and usefully, especially in resource-constrained settings. We performed an in-depth case study of one data sharing pioneer: the WorldWide Antimalarial Resistance Network (WWARN. Methods: The case study included a records review, a quantitative analysis of WAARN-related publications, in-depth interviews with 47 people familiar with WWARN, and a witness seminar involving a sub-set of 11 interviewees. Results: WWARN originally aimed to collate clinical, in vitro, pharmacological and molecular data into linked, open-access databases intended to serve as a public resource to guide antimalarial drug treatment policies. Our study describes how WWARN navigated challenging institutional and academic incentive structures, alongside funders' reluctance to invest in capacity building in malaria-endemic countries, which impeded data sharing. The network increased data contributions by focusing on providing free, online tools to improve the quality and efficiency of data collection, and by inviting collaborative authorship on papers addressing policy-relevant questions that could only be answered through pooled analyses. By July 1, 2016, the database included standardised data from 103 molecular studies and 186 clinical trials, representing 135,000 individual patients. Developing the database took longer and cost more than anticipated, and efforts to increase equity for data contributors are on-going. However, analyses of the pooled data have generated new methods and influenced malaria treatment recommendations globally. Despite not achieving the initial goal of real-time surveillance, WWARN has developed strong data governance and curation tools, which are now being adapted relatively quickly for other diseases. Conclusions: To be useful, data sharing requires

  15. Determination of antibiotic resistance of lactic acid bacteria isolated from traditional Turkish fermented dairy products.

    Science.gov (United States)

    Erginkaya, Z; Turhan, E U; Tatlı, D

    2018-01-01

    In this study, the antibiotic resistance (AR) of lactic acid bacteria (LAB) isolated from traditional Turkish fermented dairy products was investigated. Yogurt, white cheese, tulum cheese, cokelek, camız cream and kefir as dairy products were collected from various supermarkets. Lactic acid bacteria such as Lactobacillus spp., Streptococcus spp., Bifidobacterium spp., and Enterecoccus spp. were isolated from these dairy products. Lactobacillus spp. were resistant to vancomycin (58%), erythromycin (10.8%), tetracycline (4.3%), gentamicin (28%), and ciprofloxacin (26%). Streptococcus spp. were resistant to vancomycin (40%), erythromycin (10%), chloramphenicol (10%), gentamicin (20%), and ciprofloxacin (30%). Bifidobacterium spp. were resistant to vancomycin (60%), E 15 (6.6%), gentamicin (20%), and ciprofloxacin (33%). Enterococcus spp. were resistant to vancomycin (100%), erythromycin (100%), rifampin (100%), and ciprofloxacin (100%). As a result, LAB islated from dairy products in this study showed mostly resistance to vancomycin.

  16. Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore.

    Science.gov (United States)

    Fraser, Kevin C; Stutchbury, Bridget J M; Silverio, Cassandra; Kramer, Patrick M; Barrow, John; Newstead, David; Mickle, Nanette; Cousens, Bruce F; Lee, J Charlene; Morrison, Danielle M; Shaheen, Tim; Mammenga, Paul; Applegate, Kelly; Tautin, John

    2012-12-22

    North American birds that feed on flying insects are experiencing steep population declines, particularly long-distance migratory populations in the northern breeding range. We determine, for the first time, the level of migratory connectivity across the range of a songbird using direct tracking of individuals, and test whether declining northern populations have higher exposure to agricultural landscapes at their non-breeding grounds in South America. We used light-level geolocators to track purple martins, Progne subis, originating from North American breeding populations, coast-to-coast (n = 95 individuals). We show that breeding populations of the eastern subspecies, P. s. subis, that are separated by ca. 2000 km, nevertheless have almost completely overlapping non-breeding ranges in Brazil. Most (76%) P. s. subis overwintered in northern Brazil near the Amazon River, not in the agricultural landscape of southern Brazil. Individual non-breeding sites had an average of 91 per cent forest and only 4 per cent agricultural ground cover within a 50 km radius, and birds originating from declining northern breeding populations were not more exposed to agricultural landscapes than stable southern breeding populations. Our results show that differences in wintering location and habitat do not explain recent trends in breeding population declines in this species, and instead northern populations may be constrained in their ability to respond to climate change.

  17. Determination of the specific resistance of individual freestanding ZnO nanowires with the low energy electron point source microscope

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Dirk Henning; Beyer, Andre; Voelkel, Berthold; Goelzhaeuser, Armin [Physik Supramolekularer Systeme, Universitaet Bielefeld (Germany); Schlenker, Eva; Bakin, Andrey; Waag, Andreas [Institut fuer Halbleitertechnik, Technische Universitaet Braunschweig (Germany)

    2008-07-01

    A low energy electron point source (LEEPS) microscope is used to determine the electrical conductivity of individual freestanding ZnO nanowires in UHV. The nanowires were contacted with a manipulation tip and I-V curves were taken at different wire lengths. From those, the specific resistance was calculated and separated from the contact resistance. By comparing the specific resistances of ZnO nanowires with diameters between 1100 and 48 nm, a large surface contribution for the thin nanowires was found. A geometric model for separation between surface and bulk contributions is given. The results of electrical transport measurements on vapor phase grown ZnO nanowires are discussed, as well as the size dependence of the wire resistance.

  18. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    Energy Technology Data Exchange (ETDEWEB)

    Saw, S. H. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); Lee, S. [INTI University College, Nilai 71800 (Malaysia); Institute for Plasma Focus Studies, 32 Oakpark Drive, Chadstone, Victoria 3148 (Australia); National Institute of Education, Nanyang Technological University, Singapore 637616 (Singapore); Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A. [INTI University College, Nilai 71800 (Malaysia)

    2010-05-15

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L{sub 0}, and resistance r{sub 0} to be obtained using lightly damped sinusoid equations given the bank capacitance C{sub 0}. However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  19. Detection of Genes that Determine Maize Grain Quality Characteristics and Resistance to Stress Factors

    Directory of Open Access Journals (Sweden)

    Markovskyi, O.V.

    2014-01-01

    Full Text Available 200 experimental maize samples (Maize Company were examined for the presence of genes that determine the quality characteristics of grain (wx and fl-2 genes, herbicide (bar (pat, epsps genes and insect (cry-genes resistance. The total DNA was extracted from maize living plant tissue. Primers to detect wx, fl-2, bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 genes were designed and selected. Multiplex and Touchdown PCR were worked out. PCR amplification of certain sequences was carried out. No transgenes (bar (pat, mepsps, CP4 epsps, cry1A(b, cry1F, cry1A.105, mcry3A, cry2Ab2, cry3Bb1, cry34Ab1, cry35Ab1 were found among 200 analyzed experimental maize samples. At the same time, fl-2 gene was found in 41 samples, wx gene was found in 192 analyzed samples.

  20. In situ determination of the static inductance and resistance of a plasma focus capacitor bank

    International Nuclear Information System (INIS)

    Saw, S. H.; Lee, S.; Roy, F.; Chong, P. L.; Vengadeswaran, V.; Sidik, A. S. M.; Leong, Y. W.; Singh, A.

    2010-01-01

    The static (unloaded) electrical parameters of a capacitor bank are of utmost importance for the purpose of modeling the system as a whole when the capacitor bank is discharged into its dynamic electromagnetic load. Using a physical short circuit across the electromagnetic load is usually technically difficult and is unnecessary. The discharge can be operated at the highest pressure permissible in order to minimize current sheet motion, thus simulating zero dynamic load, to enable bank parameters, static inductance L 0 , and resistance r 0 to be obtained using lightly damped sinusoid equations given the bank capacitance C 0 . However, for a plasma focus, even at the highest permissible pressure it is found that there is significant residual motion, so that the assumption of a zero dynamic load introduces unacceptable errors into the determination of the circuit parameters. To overcome this problem, the Lee model code is used to fit the computed current trace to the measured current waveform. Hence the dynamics is incorporated into the solution and the capacitor bank parameters are computed using the Lee model code, and more accurate static bank parameters are obtained.

  1. A genome-wide association study of field and seedling response to stem rust pathogen races reveals combinations of race-specific resistance genes in North American spring wheat

    Science.gov (United States)

    Stem rust of wheat caused by the fungal pathogen Puccinia graminis f. sp. tritici historically caused major yield losses of wheat worldwide. To understand the genetic basis of stem rust resistance in conventional North American spring wheat, genome-wide association analysis (GWAS) was conducted on a...

  2. Skid resistance determination for pavement management and wet-weather road safety

    Directory of Open Access Journals (Sweden)

    T.F. Fwa

    2017-09-01

    Full Text Available Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the skid resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement skid resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement skid resistance under various rainfall intensities, the minimum skid resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum skid resistance threshold is inadequate to offer a complete description of the skid resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum skid resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement skid resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element skid resistance simulation model to predict skid resistance. The application of the proposed approach and the skid resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.

  3. Determination of nonlinear resistance voltage-current relationships by measuring harmonics

    Science.gov (United States)

    Stafford, J. M.

    1971-01-01

    Test configuration measures harmonic signal amplitudes generated in nonlinear resistance. Vacuum-type voltmeter measures low frequency sinusoidal input signal amplitude and wave-analyzer measures amplitude of harmonic signals generated in junction. Input signal harmonics amplitude must not exceed that of harmonics generated in nonlinear resistance.

  4. Mechanisms of Linezolid Resistance among Coagulase-Negative Staphylococci Determined by Whole-Genome Sequencing

    Science.gov (United States)

    Tewhey, Ryan; Gu, Bing; Kelesidis, Theodoros; Charlton, Carmen; Bobenchik, April; Hindler, Janet; Schork, Nicholas J.

    2014-01-01

    ABSTRACT Linezolid resistance is uncommon among staphylococci, but approximately 2% of clinical isolates of coagulase-negative staphylococci (CoNS) may exhibit resistance to linezolid (MIC, ≥8 µg/ml). We performed whole-genome sequencing (WGS) to characterize the resistance mechanisms and genetic backgrounds of 28 linezolid-resistant CoNS (21 Staphylococcus epidermidis isolates and 7 Staphylococcus haemolyticus isolates) obtained from blood cultures at a large teaching health system in California between 2007 and 2012. The following well-characterized mutations associated with linezolid resistance were identified in the 23S rRNA: G2576U, G2447U, and U2504A, along with the mutation C2534U. Mutations in the L3 and L4 riboproteins, at sites previously associated with linezolid resistance, were also identified in 20 isolates. The majority of isolates harbored more than one mutation in the 23S rRNA and L3 and L4 genes. In addition, the cfr methylase gene was found in almost half (48%) of S. epidermidis isolates. cfr had been only rarely identified in staphylococci in the United States prior to this study. Isolates of the same sequence type were identified with unique mutations associated with linezolid resistance, suggesting independent acquisition of linezolid resistance in each isolate. PMID:24915435

  5. GenoType HelicoDR test in the determination of antimicrobial resistance of Helicobacter pylori in Korea.

    Science.gov (United States)

    Lee, Jung Won; Kim, Nayoung; Nam, Ryoung Hee; Park, Ji Hyun; Choi, Yoon Jin; Kim, Jung Mogg; Kim, Joo Sung; Jung, Hyun Chae

    2014-09-01

    Antimicrobial resistance of Helicobacter pylori is most important factor in eradication success. GenoType HelicoDR test has been developed for rapid detection of antimicrobial resistance. The present study evaluated the clinical usefulness of GenoType HelicoDR test in Korea. To detect 23S rRNA for clarithromycin resistance and gyrA mutations for fluoroquinolone resistance, both DNA sequencing after minimal inhibitory test (MIC) and GenoType HelicoDR test were performed in H. pylori isolates from the gastric mucosa of 101 patients. The eradication results of clarithromycin and moxifloxacin-containing triple therapy were evaluated by the 23S rRNA and gyrA mutations. For 42 isolates with A2143G mutation by GenoType HelicoDR, 83.3% (35/42) of concordance rate was estimated with DNA sequencing method and 85.7% (36/42) for MIC test. For 43 isolates with N87K mutation by GenoType HelicoDR, 71.1% (31/43) of concordance rate was estimated with DNA sequencing and 88.4% (38/43) for MIC test. The sensitivity and specificity of GenoType HelicoDR test in determination of 23S rRNA mutation were 94.9% and 87.1%, and those of gyrA 98.2% and 80.0%. The sensitivity and specificity of GenoType HelicoDR test in determination of clarithromycin resistance based on MIC test were 55.0% and 80.0%, for fluoroquinolone 74.4% and 70.0%. GenoType HelicoDR test is useful to determine mutations responsible for clarithromycin or fluoroquinolone-containing eradication failure but has a limitation for the clinical applicability in determination of resistance.

  6. Determinants of between-country differences in ambulatory antibiotic use and antibiotic resistance in Europe: a longitudinal observational study.

    Science.gov (United States)

    Blommaert, A; Marais, C; Hens, N; Coenen, S; Muller, A; Goossens, H; Beutels, P

    2014-02-01

    To identify key determinants explaining country-year variations in antibiotic use and resistance. Ambulatory antibiotic use data [in defined daily doses per 1000 inhabitants per day (DIDs)] for 19 European countries from 1999 to 2007 were collected, along with 181 variables describing countries in terms of their agriculture, culture, demography, disease burden, education, healthcare organization and socioeconomics. After assessing data availability, overlap and relevance, multiple imputation generalized estimating equations were applied with a stepwise selection procedure to select significant determinants of global antibiotic use (expressed in DIDs), relative use of subgroups (amoxicillin and co-amoxiclav) and resistance of Escherichia coli and Streptococcus pneumoniae. Relative humidity, healthcare expenditure proportional to gross domestic product, feelings of distrust, proportion of population aged >65 years and availability of treatment guidelines were associated with higher total antibiotic use expressed in DIDs. Restrictions on marketing activities towards prescribers, population density, number of antibiotics, educational attainment and degree of atheism were associated with a lower number of total DIDs used. Relative prescribing of amoxicillin and co-amoxiclav was mainly determined by healthcare system choices [e.g. general practitioner (GP) registration and restricted marketing]. Specific antibiotic use was found to be a significant determinant of resistance for some but not all drug/organism combinations. Incentives to stimulate GP gatekeeping were associated with lower levels of resistance, and life expectancy at age 65+ and atheism were associated with more resistance. Myriad factors influence antibiotic use and resistance at the country level and an important part of these can be modified by policy choices.

  7. Determinants of Antimicrobial Resistance in Escherichia coli Strains Isolated from Faeces and Urine of Women with Recurrent Urinary Tract Infections

    NARCIS (Netherlands)

    den Heijer, Casper D. J.; Beerepoot, Mariëlle A. J.; Prins, Jan M.; Geerlings, Suzanne E.; Stobberingh, Ellen E.

    2012-01-01

    For women with recurrent urinary tract infections (rUTI), the contribution of antibiotic use versus patient-related factors in determining the presence of antimicrobial resistance in faecal and urinary Escherichia coli, obtained from the same patient population, has not been assessed yet. Within the

  8. Method of determination of temperature and heat resistance of the points on the integrated circuit crystal surface

    Directory of Open Access Journals (Sweden)

    Popov V. M.

    2011-12-01

    Full Text Available Method for visualization of integrated circuit (IC surface temperature by means of the liquid crystal film deposited from solution on its surface is proposed. The boundaries of local regions represent isotherms with corresponding phase transitions. On the base of isotherms positions and consumed by IC power thermal resistances between crystal and environment are determined.

  9. Determination of withdrawal resistance of staple joints constructed with various members of upholstered furniture

    Directory of Open Access Journals (Sweden)

    saeid Kazemi Najafi

    2017-05-01

    Full Text Available The goal of this study was to investigate the effects of joints members type (oriented strand lumber, plywood and poplar wood (Populusdeltoides, penetration deeps of staple (12 and 17mm and adhesives (with and without adhesive on face and edge withdrawal resistance of joints fabricated with staple. Experimental specimens under withdrawal load test of face and edge consisted of two principal structural members, main member and a secondary member which were joined together by one staple. The results showed that joint member, penetration deeps and adhesive significantly influence on the withdrawal resistance. Staple withdrawal resistance in the face was higher than that in the edge. Staple holding resistance increased with the increase of penetration deep and the withdrawal resistance of joints fabricated by adhesive was higher than those without adhesive. The joints made by oriented strand lumber exhibited better performance than other two members and joints made with poplar wood had higher resistance than plywood joints. The highest face (2326N and edge (1265N withdrawal resistances were obtained from joints prepared from oriented strand lumber with adhesive and17mm penetration deeps.

  10. Pathogenicity determinants and antibiotic resistance profiles of enterococci from foods of animal origin in Turkey.

    Science.gov (United States)

    Elal Mus, Tulay; Cetinkaya, Figen; Cibik, Recep; Soyutemiz, Gul Ece; Simsek, Husniye; Coplu, Nilay

    2017-12-01

    In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.

  11. The Application of 2-D Resistivity and Self Potential (SP) Methods in Determining the Water Flow

    Science.gov (United States)

    Nordiana, M. M.; Tajudeen Olugbenga, Adeeko; Afiq Saharudin, Muhamad; nabila, S.; El Hidayah Ismail, Noer

    2018-04-01

    Existence of water flow at urban area will decrease the shear strength and increase hydraulic conductivity of soil which finally caused subsurface problems at this area. To avoid landslide, slope instability and disturbance of the ecosystem, good and detailed planning must be done when developing hilly area. The understanding about geological condition has to be considering before construction activities be done. Six 2-D resistivity survey lines with minimum 5 m electrode spacing were executed using Pole-dipole array. The field investigation such as borehole was carried out at multiple locations in the area where the 2-D resistivity method have been conducted. The directions and intensities of the water were evaluated with self-potential (SP) method. Subsequently, the results from borehole were used to verify the results of electrical resistivity method. Interpretation of 2-D resistivity data showed a low resistivity value (ohm-m), which appears to be a zone that is fully saturated with sandy silt and this could be an influence factor the increasing water level because sandy silt is highly permeable in nature. The borehole, support the results of 2-D resistivity method relating a saturated zone in the survey area. There is a good correlation between the 2-D resistivity investigations and the results of borehole records.

  12. New test procedure to determine fuel's knock resistance; Neues Kraftstoffpruefverfahren zur Bestimmung der Klopffestigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Karl [Hochschule Ingolstadt (Germany). Thermodynamik und Verbrennungsmotoren; Hauber, Johann; Raba, Andreas [Hochschule Ingolstadt (Germany). Inst. fuer Angewandte Forschung; Nell, Robert [Rofa Laboratory and Process Analyzers, Kritzendorf (Austria). Bereich Produktentwicklung

    2013-07-15

    Knock resistance is one of the most important quality features of gasoline that is determined by standardised motor test procedures. These procedures were developed more than 80 years ago and have been used nearly unchanged since then. During a four-year research project at Ingolstadt University of Applied Sciences, the procedures for determination of octane numbers were analysed in order to develop a new engine-based test method. (orig.)

  13. Genetic Determinants of Cisplatin Resistance in Patients With Advanced Germ Cell Tumors.

    Science.gov (United States)

    Bagrodia, Aditya; Lee, Byron H; Lee, William; Cha, Eugene K; Sfakianos, John P; Iyer, Gopa; Pietzak, Eugene J; Gao, Sizhi Paul; Zabor, Emily C; Ostrovnaya, Irina; Kaffenberger, Samuel D; Syed, Aijazuddin; Arcila, Maria E; Chaganti, Raju S; Kundra, Ritika; Eng, Jana; Hreiki, Joseph; Vacic, Vladimir; Arora, Kanika; Oschwald, Dayna M; Berger, Michael F; Bajorin, Dean F; Bains, Manjit S; Schultz, Nikolaus; Reuter, Victor E; Sheinfeld, Joel; Bosl, George J; Al-Ahmadie, Hikmat A; Solit, David B; Feldman, Darren R

    2016-11-20

    Purpose Owing to its exquisite chemotherapy sensitivity, most patients with metastatic germ cell tumors (GCTs) are cured with cisplatin-based chemotherapy. However, up to 30% of patients with advanced GCT exhibit cisplatin resistance, which requires intensive salvage treatment, and have a 50% risk of cancer-related death. To identify a genetic basis for cisplatin resistance, we performed whole-exome and targeted sequencing of cisplatin-sensitive and cisplatin-resistant GCTs. Methods Men with GCT who received a cisplatin-containing chemotherapy regimen and had available tumor tissue were eligible to participate in this study. Whole-exome sequencing or targeted exon-capture-based sequencing was performed on 180 tumors. Patients were categorized as cisplatin sensitive or cisplatin resistant by using a combination of postchemotherapy parameters, including serum tumor marker levels, radiology, and pathology at surgical resection of residual disease. Results TP53 alterations were present exclusively in cisplatin-resistant tumors and were particularly prevalent among primary mediastinal nonseminomas (72%). TP53 pathway alterations including MDM2 amplifications were more common among patients with adverse clinical features, categorized as poor risk according to the International Germ Cell Cancer Collaborative Group (IGCCCG) model. Despite this association, TP53 and MDM2 alterations predicted adverse prognosis independent of the IGCCCG model. Actionable alterations, including novel RAC1 mutations, were detected in 55% of cisplatin-resistant GCTs. Conclusion In GCT, TP53 and MDM2 alterations were associated with cisplatin resistance and inferior outcomes, independent of the IGCCCG model. The finding of frequent TP53 alterations among mediastinal primary nonseminomas may explain the more frequent chemoresistance observed with this tumor subtype. A substantial portion of cisplatin-resistant GCTs harbor actionable alterations, which might respond to targeted therapies. Genomic

  14. An NS5A single optimized method to determine genotype, subtype and resistance profiles of Hepatitis C strains.

    Directory of Open Access Journals (Sweden)

    Elisabeth Andre-Garnier

    Full Text Available The objective was to develop a method of HCV genome sequencing that allowed simultaneous genotyping and NS5A inhibitor resistance profiling. In order to validate the use of a unique RT-PCR for genotypes 1-5, 142 plasma samples from patients infected with HCV were analysed. The NS4B-NS5A partial region was successfully amplified and sequenced in all samples. In parallel, partial NS3 sequences were analyzed obtained for genotyping. Phylogenetic analysis showed concordance of genotypes and subtypes with a bootstrap >95% for each type cluster. NS5A resistance mutations were analyzed using the Geno2pheno [hcv] v0.92 tool and compared to the list of known Resistant Associated Substitutions recently published. In conclusion, this tool allows determination of HCV genotypes, subtypes and identification of NS5A resistance mutations. This single method can be used to detect pre-existing resistance mutations in NS5A before treatment and to check the emergence of resistant viruses while undergoing treatment in major HCV genotypes (G1-5 in the EU and the US.

  15. Informed herbivore movement and interplant communication determine the effects of induced resistance in an individual-based model.

    Science.gov (United States)

    Rubin, Ilan N; Ellner, Stephen P; Kessler, André; Morrell, Kimberly A

    2015-09-01

    1. Plant induced resistance to herbivory affects the spatial distribution of herbivores, as well as their performance. In recent years, theories regarding the benefit to plants of induced resistance have shifted from ideas of optimal resource allocation towards a more eclectic set of theories that consider spatial and temporal plant variability and the spatial distribution of herbivores among plants. However, consensus is lacking on whether induced resistance causes increased herbivore aggregation or increased evenness, as both trends have been experimentally documented. 2. We created a spatial individual-based model that can describe many plant-herbivore systems with induced resistance, in order to analyse how different aspects of induced resistance might affect herbivore distribution, and the total damage to a plant population, during a growing season. 3. We analyse the specific effects on herbivore aggregation of informed herbivore movement (preferential movement to less-damaged plants) and of information transfer between plants about herbivore attacks, in order to identify mechanisms driving both aggregation and evenness. We also investigate how the resulting herbivore distributions affect the total damage to plants and aggregation of damage. 4. Even, random and aggregated herbivore distributions can all occur in our model with induced resistance. Highest levels of aggregation occurred in the models with informed herbivore movement, and the most even distributions occurred when the average number of herbivores per plant was low. With constitutive resistance, only random distributions occur. Damage to plants was spatially correlated, unless plants recover very quickly from damage; herbivore spatial autocorrelation was always weak. 5. Our model and results provide a simple explanation for the apparent conflict between experimental results, indicating that both increased aggregation and increased evenness of herbivores can result from induced resistance. We

  16. In vitro antimicrobial susceptibility and genetic resistance determinants of Streptococcus agalactiae isolated from mastitic cows in Brazilian dairy herds

    Directory of Open Access Journals (Sweden)

    Juliana Rosa da Silva

    2017-08-01

    Full Text Available Streptococcus agalactiae is one of the main causative agents of bovine mastitis and is associated with several economic losses for producers. Few studies have evaluated antimicrobial susceptibility and the prevalence of genetic resistance determinants among isolates of this bacterium from Brazilian dairy cattle. This work aimed to evaluate the frequency of the antimicrobial resistance genes ermA, ermB, mefA, tetO, tetM, aphA3, and aad-6, and in vitro susceptibility to the antimicrobials amikacin, erythromycin, clindamycin, tetracycline, gentamicin, penicillin, ceftiofur, and cefalotin, and the associations between resistance genotypes and phenotypes among 118 S. agalactiae isolates obtained from mastitic cows in Brazilian dairy herds. Of the resistance genes examined, ermB was found in 19 isolates (16.1%, tetO in 23 (19.5%, and tetM in 24 (20.3%. The genes ermA, mefA, aphA3, and aad-6 were not identified. There was an association between the presence of genes ermB, tetM, and tetO and phenotypic resistance to erythromycin, clindamycin, and tetracycline. Rates of resistance to the tested antibiotics varied, as follows: erythromycin (19.5%, tetracycline (35.6%, gentamicin (9.3%, clindamycin (20.3%, penicillin (3.4%, and amikacin (38.1%; conversely, all isolates were susceptible to ceftiofur and cefalotin. Antimicrobial resistance testing facilitates the treatment decision process, allowing the most judicious choice of antibiotics. Moreover, it enables regional and temporal monitoring of the resistance dynamics of this pathogen of high importance to human and animal health.

  17. Country-wide surveillance of molecular markers of antimalarial drug resistance in Senegal by use of positive Malaria Rapid Diagnostic Tests

    DEFF Research Database (Denmark)

    Ndiaye, Magatte; Sow, Doudou; Nag, Sidsel

    2017-01-01

    of drug resistance. Therefore, surveillance of drug resistance in the malaria parasites is essential. The objective of this pilot study was to test the feasibility of routinely sampled malaria rapid diagnostic tests (RDTs) at a national scale to assess the temporal changes in the molecular profiles...... of antimalarial drug resistance markers of Plasmodium falciparum parasites. Overall, 9,549 positive malaria RDTs were collected from 14 health facilities across the country. A limited random set of RDTs were analyzed regarding Pfcrt gene polymorphisms at codon 72-76. Overall, a high but varied prevalence (> 50...

  18. Enhanced resistance to fluoroquinolones in laboratory-grown mutants & clinical isolates of Shigella due to synergism between efflux pump expression & mutations in quinolone resistance determining region

    Directory of Open Access Journals (Sweden)

    Neelam Taneja

    2015-01-01

    Full Text Available Background & objectives: There is a worldwide emergence of fluoroquinolone resistance in Shigella species. To understand the molecular mechanisms associated with fluoroquinolone resistance, naturally occurring fluoroquinolone-resistant strains and laboratory-induced spontaneous mutants of Shigella spp. were used and the relative contributions of acrAB-tolC efflux pumps, gyrase and topoisomerase target gene mutations towards fluoroquinolone resistance were determined. Methods: Eight Shigella flexneri and six S. dysenteriae clinical isolates were studied. Three consecutive mutants resistant to ciprofloxacin for S. flexneri SFM1 (≥0.25 µg/ml, SFM2 (≥4 µg/ml and SFM3 (≥32 µg/ml were selected in 15 steps from susceptible isolates by serial exposure to increasing concentrations of nalidixic acid and ciprofloxacin. Similarly, two mutants for S. dysenteriae SDM1 (≥0.25 µg/ml and SDM2 (≥4 µg/ml were selected in eight steps. After PCR amplification sequence analyses of gyrase and topoisomerase target genes were performed. Expression of efflux genes acrA, acrB, acrR and tolC was measured using real-time PCR. Results: Mutations were observed in gyrA Ser [83]→Leu, Asp [87]→Asn/Gly, Val [196]→Ala and in parC Phe [93]→Val, Ser [80]→Ile, Asp [101]→Glu and Asp [110]→Glu. Overall, acrA and acrB overexpression was associated with fluoroquinolone resistance ( p0 <0.05; while tolC and acrR expression levels did not. Interpretation & conclusions: Fluoroquinolone resistance in Shigella spp. is the end product of either a single or a combination of mutations in QRDRs and/ or efflux activity. Novel polymorphisms were observed at Val [196]→Ala in gyrA in clinical isolates and Phe [93]→Val, Asp [101]→Glu, Asp [110]→Glu and in parC in majority of laboratory-grown mutants.

  19. Automated ribotyping and antibiotic resistance determining of Bacillus spp from conjunctiva of diabetic patients

    Directory of Open Access Journals (Sweden)

    Sertaç Argun Kıvanç

    2014-02-01

    Conclusion: Diabetic patients seem to be more prone to B. cereus infections than healthy individuals. It would be greatly beneficial to understand and recognize the prevalence of microorganisms and their resistance patterns for better outcome in ocular surgeries.

  20. Genetic Determinants of Drug Resistance in Mycobacterium tuberculosis and Their Diagnostic Value

    NARCIS (Netherlands)

    Farhat, M.R.; Sultana, R.; Iartchouk, O.; Bozeman, S.; Galagan, J.; Sisk, P.; Stolte, C.; Nebenzahl-Guimaraes, H.; Jacobson, K.; Sloutsky, A.; Kaur, D.; Posey, J.; Kreiswirth, B.N.; Kurepina, N.; Rigouts, L.; Streicher, E.M.; Victor, T.C.; Warren, R.M.; Soolingen, D. van; Murray, M.

    2016-01-01

    RATIONALE: The development of molecular diagnostics that detect both the presence of Mycobacterium tuberculosis in clinical samples and drug resistance-conferring mutations promises to revolutionize patient care and interrupt transmission by ensuring early diagnosis. However, these tools require the

  1. Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, M.; Ulanová, Dana; Šanderová, P.; Omelka, M.; Kameník, Zdeněk; Olšovská, J.; Kopecký, J.

    2015-01-01

    Roč. 15, APR 2015 (2015) ISSN 1471-2180 Institutional support: RVO:61388971 Keywords : Actinobacteria * 16S rRNA diversity * Resistance genes Subject RIV: EH - Ecology, Behaviour Impact factor: 2.581, year: 2015

  2. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc; McNerney, Ruth; Preston, Mark D; Guerra-Assunç ã o, José Afonso; Warry, Andrew; Hill-Cawthorne, Grant A.; Mallard, Kim; Nair, Mridul; Miranda, Anabela; Alves, Adriana; Perdigã o, Joã o; Viveiros, Miguel; Portugal, Isabel; Hasan, Zahra; Hasan, Rumina; Glynn, Judith R; Martin, Nigel; Pain, Arnab; Clark, Taane G

    2015-01-01

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data

  3. Identifying Chloris Species from Cuban Citrus Orchards and Determining Their Glyphosate-Resistance Status

    Directory of Open Access Journals (Sweden)

    Enzo R. Bracamonte

    2017-11-01

    Full Text Available The Chloris genus is a C4 photosynthetic species mainly distributed in tropical and subtropical regions. Populations of three Chloris species occurring in citrus orchards from central Cuba, under long history glyphosate-based weed management, were studied for glyphosate-resistant status by characterizing their herbicide resistance/tolerance mechanisms. Morphological and molecular analyses allowed these species to be identified as C. ciliata Sw., Chloris elata Desv., and Chloris barbata Sw. Based on the glyphosate rate that causes 50% mortality of the treated plants, glyphosate resistance (R was confirmed only in C. elata, The R population was 6.1-fold more resistant compared to the susceptible (S population. In addition, R plants of C. elata accumulated 4.6-fold less shikimate after glyphosate application than S plants. Meanwhile, populations of C. barbata and C. ciliata with or without glyphosate application histories showed similar LD50 values and shikimic acid accumulation rates, demonstrating that resistance to glyphosate have not evolved in these species. Plants of R and S populations of C. elata differed in 14C-glyphosate absorption and translocation. The R population exhibited 27.3-fold greater 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS activity than the S population due to a target site mutation corresponding to a Pro-106-Ser substitution found in the EPSPS gene. These reports show the innate tolerance to glyphosate of C. barbata and C. ciliata, and confirm the resistance of C. elata to this herbicide, showing that both non-target site and target-site mechanisms are involved in its resistance to glyphosate. This is the first case of herbicide resistance in Cuba.

  4. Epistatic determinism of durum wheat resistance to the wheat spindle streak mosaic virus.

    Science.gov (United States)

    Holtz, Yan; Bonnefoy, Michel; Viader, Véronique; Ardisson, Morgane; Rode, Nicolas O; Poux, Gérard; Roumet, Pierre; Marie-Jeanne, Véronique; Ranwez, Vincent; Santoni, Sylvain; Gouache, David; David, Jacques L

    2017-07-01

    The resistance of durum wheat to the Wheat spindle streak mosaic virus (WSSMV) is controlled by two main QTLs on chromosomes 7A and 7B, with a huge epistatic effect. Wheat spindle streak mosaic virus (WSSMV) is a major disease of durum wheat in Europe and North America. Breeding WSSMV-resistant cultivars is currently the only way to control the virus since no treatment is available. This paper reports studies of the inheritance of WSSMV resistance using two related durum wheat populations obtained by crossing two elite cultivars with a WSSMV-resistant emmer cultivar. In 2012 and 2015, 354 recombinant inbred lines (RIL) were phenotyped using visual notations, ELISA and qPCR and genotyped using locus targeted capture and sequencing. This allowed us to build a consensus genetic map of 8568 markers and identify three chromosomal regions involved in WSSMV resistance. Two major regions (located on chromosomes 7A and 7B) jointly explain, on the basis of epistatic interactions, up to 43% of the phenotypic variation. Flanking sequences of our genetic markers are provided to facilitate future marker-assisted selection of WSSMV-resistant cultivars.

  5. Resistance to infection with Eimeria vermiformis in mouse radiation chimeras is determined by donor bone-marrow cells

    International Nuclear Information System (INIS)

    Joysey, H.S.; Wakelin, D.; Rose, M.E.

    1988-01-01

    The course of infection with Eimeria vermiformis was determined in BALB/b, BALB/c, and C57BL/10ScSn (B10) mice and in radiation chimeras prepared from the H-2-compatible BALB/b and B10 mice. The BALB strains, irrespective of H-2 haplotype, were resistant, the B10 mice were susceptible, and in the chimeras infection was characterized by the genotype of the donated bone-marrow cells and not by the phenotype of the recipient. Thus, the genetic control of relative resistance or susceptibility to infection with this parasite is expressed through bone-marrow-derived cells

  6. Validation of the method for determination of the thermal resistance of fouling in shell and tube heat exchangers

    International Nuclear Information System (INIS)

    Markowski, Mariusz; Trafczynski, Marian; Urbaniec, Krzysztof

    2013-01-01

    Highlights: • Heat recovery in a heat exchanger network (HEN). • A novel method for on-line determination of the thermal resistance of fouling is presented. • Details are developed for shell and tube heat exchangers. • The method was validated and sensibility analysis was carried out. • Developed approach allows long-term monitoring of changes in the HEN efficiency. - Abstract: A novel method for on-line determination of the thermal resistance of fouling in shell and tube heat exchangers is presented. It can be applied under the condition that the data on pressure, temperature, mass flowrate and thermophysical properties of both heat-exchanging media are continuously available. The calculation algorithm for use in the novel method is robust and ensures reliable determination of the thermal resistance of fouling even if the operating parameters fluctuate. The method was validated using measurement data retrieved from the operation records of a heat exchanger network connected with a crude distillation unit rated 800 t/h. Sensibility analysis of the method was carried out and the calculated values of the thermal resistance of fouling were critically reviewed considering the results of qualitative evaluation of fouling layers in the exchangers inspected during plant overhaul

  7. Genome wide discovery of long intergenic non-coding RNAs in Diamondback moth (Plutella xylostella) and their expression in insecticide resistant strains

    Science.gov (United States)

    Etebari, Kayvan; Furlong, Michael J.; Asgari, Sassan

    2015-01-01

    Long non-coding RNAs (lncRNAs) play important roles in genomic imprinting, cancer, differentiation and regulation of gene expression. Here, we identified 3844 long intergenic ncRNAs (lincRNA) in Plutella xylostella, which is a notorious pest of cruciferous plants that has developed field resistance to all classes of insecticides, including Bacillus thuringiensis (Bt) endotoxins. Further, we found that some of those lincRNAs may potentially serve as precursors for the production of small ncRNAs. We found 280 and 350 lincRNAs that are differentially expressed in Chlorpyrifos and Fipronil resistant larvae. A survey on P. xylostella midgut transcriptome data from Bt-resistant populations revealed 59 altered lincRNA in two resistant strains compared with the susceptible population. We validated the transcript levels of a number of putative lincRNAs in deltamethrin-resistant larvae that were exposed to deltamethrin, which indicated that this group of lincRNAs might be involved in the response to xenobiotics in this insect. To functionally characterize DBM lincRNAs, gene ontology (GO) enrichment of their associated protein-coding genes was extracted and showed over representation of protein, DNA and RNA binding GO terms. The data presented here will facilitate future studies to unravel the function of lincRNAs in insecticide resistance or the response to xenobiotics of eukaryotic cells. PMID:26411386

  8. Stab resistant body armour

    OpenAIRE

    Horsfall, I

    2000-01-01

    There is now a widely accepted need for stab resistant body armour for the police in the UK. However, very little research has been done on knife resistant systems and the penetration mechanics of sharp projectiles are poorly understood. This thesis explores the general background to knife attack and defence with a particular emphasis on the penetration mechanics of edged weapons. The energy and velocity that can be achieved in stabbing actions has been determined for a numb...

  9. Unique Determinants of Neuraminidase Inhibitor Resistance among N3, N7, and N9 Avian Influenza Viruses.

    Science.gov (United States)

    Song, Min-Suk; Marathe, Bindumadhav M; Kumar, Gyanendra; Wong, Sook-San; Rubrum, Adam; Zanin, Mark; Choi, Young-Ki; Webster, Robert G; Govorkova, Elena A; Webby, Richard J

    2015-11-01

    Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only numerous NAI-resistant

  10. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    International Nuclear Information System (INIS)

    Koshikawa, Tomihiko

    1994-01-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.)

  11. Handling technique of spore-forming bacteria in radiation sterilization. 2. Determination of numbers and radiation resistance of spores

    Energy Technology Data Exchange (ETDEWEB)

    Koshikawa, Tomihiko [Japan Radioisotope Association, Shiga (Japan). Koka Laboratory

    1994-12-01

    Stepwise ten-fold dilution of bacterial solution is required in the determination of bacterial spores. For this, the selection of diluted solution is important according to the purpose of experiment. First, the preparation of suspension of bacterial spores and selection of diluted solution are presented. Then, a method for determining the number of bacterial spores in materials is outlined in terms of dilution methods of bacterial solution (shaking and homogenization) and application method of diluted solution to the plating medium. Finally, a method for determining radiation resistance of spore-forming bacteria is explained according to the measurement conditions (suspension of bacterial spores and filters applied with bacterial spores). (N.K.).

  12. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Adrian Biddle

    2016-02-01

    Full Text Available Cancer stem cells (CSCs drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT and mesenchymal-to-epithelial transition (MET to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC, we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44highEpCAMlow/−CD24+ cell surface marker profile. Treatment with TGFβ and retinoic acid (RA enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

  13. Phenotypic Plasticity Determines Cancer Stem Cell Therapeutic Resistance in Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Biddle, Adrian; Gammon, Luke; Liang, Xiao; Costea, Daniela Elena; Mackenzie, Ian C

    2016-02-01

    Cancer stem cells (CSCs) drive tumour spread and therapeutic resistance, and can undergo epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET) to switch between epithelial and post-EMT sub-populations. Examining oral squamous cell carcinoma (OSCC), we now show that increased phenotypic plasticity, the ability to undergo EMT/MET, underlies increased CSC therapeutic resistance within both the epithelial and post-EMT sub-populations. The post-EMT CSCs that possess plasticity exhibit particularly enhanced therapeutic resistance and are defined by a CD44(high)EpCAM(low/-) CD24(+) cell surface marker profile. Treatment with TGFβ and retinoic acid (RA) enabled enrichment of this sub-population for therapeutic testing, through which the endoplasmic reticulum (ER) stressor and autophagy inhibitor Thapsigargin was shown to selectively target these cells. Demonstration of the link between phenotypic plasticity and therapeutic resistance, and development of an in vitro method for enrichment of a highly resistant CSC sub-population, provides an opportunity for the development of improved chemotherapeutic agents that can eliminate CSCs.

  14. Analytical profiling of mutations in quinolone resistance determining region of gyrA gene among UPEC.

    Directory of Open Access Journals (Sweden)

    Lesley R Varughese

    Full Text Available Mutations in gyrA are the primary cause of quinolone resistance encountered in gram-negative clinical isolates. The prospect of this work was to analyze the role of gyrA mutations in eliciting high quinolone resistance in uropathogenic E.coli (UPEC through molecular docking studies. Quinolone susceptibility testing of 18 E.coli strains isolated from UTI patients revealed unusually high resistance level to all the quinolones used; especially norfloxacin and ciprofloxacin. The QRDR of gyrA was amplified and sequenced. Mutations identified in gyrA of E.coli included Ser83Leu, Asp87Asn and Ala93Gly/Glu. Contrasting previous reports, we found Ser83Leu substitution in sensitive strains. Strains with S83L, D87N and A93E (A15 and A26 demonstrated norfloxacin MICs ≥1024mg/L which could be proof that Asp87Asn is necessary for resistance phenotype. Resistance to levofloxacin was comparatively lower in all the isolates. Docking of 4 quinolones (ciprofloxacin, ofloxacin, levofloxacin and norfloxacin to normal and mutated E.coli gyrase A protein demonstrated lower binding energies for the latter, with significant displacement of norfloxacin in the mutated GyrA complex and least displacement in case of levofloxacin.

  15. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae

    Directory of Open Access Journals (Sweden)

    Cynthia Annes Rubião

    2017-08-01

    Full Text Available ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN of Total Coliforms (TC, Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several antimicrobial resistance genes to pathogenic bacteria, including those from Gram-negative group. The oysters were bought from local fishermen and a total of 123 individuals were analyzed. The TC, E. coli and Enterococcus spp. MPN mean were 26,300/100 g, 3,260/100 g and 2,820/100 g, respectively. The only correlation found was between TC and E. coli. Two strains of Enterococcus spp. were resistant to three different antimicrobial categories, including a high level resistance to streptomycin. One strain presented intermediate resistance to vancomycin. The E. coli levels exceeded the limits established by international legislation. This microbiological contamination in oysters reflects the water pollution and indicates a probable contamination of other seafood species from this mangrove, which can represent a risk for consumers and a threat to the environment and public health.

  16. A technique for the determination of center of gravity and rolling resistance for tilt-seat wheelchairs.

    Science.gov (United States)

    Lemaire, E D; Lamontagne, M; Barclay, H W; John, T; Martel, G

    1991-01-01

    A balance platform setup was defined for use in the determination of the center of gravity in the sagittal plane for a wheelchair and patient. Using the center of gravity information, measurements from the wheelchair and patient (weight, tire coefficients of friction), and various assumptions (constant speed, level-concrete surface, patient-wheelchair system is a rigid body), a method for estimating the rolling resistance for a wheelchair was outlined. The center of gravity and rolling resistance techniques were validated against criterion values (center of gravity error = 1 percent, rolling resistance root mean square error = 0.33 N, rolling resistance Pearson correlation coefficient = 0.995). Consistent results were also obtained from a test dummy and five subjects. Once the center of gravity is known, it is possible to evaluate the stability of a wheelchair (in terms of tipping over) and the interaction between the level of stability and rolling resistance. These quantitative measures are expected to be of use in the setup of wheelchairs with a variable seat angle and variable wheelbase length or when making comparisons between different wheelchairs.

  17. Determination of food colorants in a wide variety of food matrices by microemulsion electrokinetic capillary chromatography. Considerations on the found concentrations and regulated consumption limits.

    Science.gov (United States)

    Bordagaray, Ane; Garcia-Arrona, Rosa; Vidal, Maider; Ostra, Miren

    2018-10-01

    Color additives are used widely by the food industry to confer a desirable appearance. Some of the most used colorants (Tartrazine (E102), Sunset Yellow (E110), Red Allure (E129) and Blue Brilliant (E133)) were determined in this study using microemulsion electrokinetic capillary chromatography (MEEKC). Regression coefficients were greater than 0.9981; intra- and inter-day precisions, in terms of percentage RSD, were less than 7.01% and 8.55%, respectively; recoveries were between 90 and 100% in most cases. LODs and LOQs ranged from 0.24 to 1.21 mg L -1 and from 0.80 to 4.03 mg L -1 , respectively. Moreover, MEEKC consumed less solvent than HPLC, making the analysis more environmentally friendly. The proposed method is suitable for the determination of colorants in a wide variety of foods. Results showed that consumers should be aware of colorants to avoid consumption exceeding recommended amounts. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Determine the Impact of Novel BRCA1 Translation Start Sites on Therapy Resistance in Ovarian Cancer

    Science.gov (United States)

    2017-09-01

    Award Number: W81XWH-15-1-0197 TITLE: PRINCIPAL INVESTIGATOR: Neil Johnson, Ph.D. CONTRACTING ORGANIZATION: Institute for Cancer Research...Therapy Resistance in Ovarian Cancer The views, opinions and/or findings contained in this report are those of the author(s) and should not be...Start Sites on Therapy 5b. GRANT NUMBER Resistance in Ovarian Cancer W81XWH-15-1-0197 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Neil

  19. Multiplex PCR To Identify Macrolide Resistance Determinants in Mannheimia haemolytica and Pasteurella multocida

    DEFF Research Database (Denmark)

    Rose, Simon; Desmolaize, Benoit; Jaju, Puneet

    2012-01-01

    The bacterial pathogens Mannheimia haemolytica and Pasteurella multocida are major etiological agents in respiratory tract infections of cattle. Although these infections can generally be successfully treated with veterinary macrolide antibiotics, a few recent isolates have shown resistance...... to these drugs. Macrolide resistance in members of the family Pasteurellaceae is conferred by combinations of at least three genes: erm(42), which encodes a monomethyltransferase and confers a type I MLS(B) (macrolide, lincosamide, and streptogramin B) phenotype; msr(E), which encodes a macrolide efflux pump...

  20. Determination of charge transfer resistance and capacitance of microbial fuel cell through a transient response analysis of cell voltage.

    Science.gov (United States)

    Ha, Phuc Thi; Moon, Hyunsoo; Kim, Byung Hong; Ng, How Yong; Chang, In Seop

    2010-03-15

    An alternative method for determining the charge transfer resistance and double-layer capacitance of microbial fuel cells (MFCs), easily implemented without a potentiostat, was developed. A dynamic model with two parameters, the charge transfer resistance and double-layer capacitance of electrodes, was derived from a linear differential equation to depict the current generation with respect to activation overvoltage. This model was then used to fit the transient cell voltage response to the current step change during the continuous operation of a flat-plate type MFC fed with acetate. Variations of the charge transfer resistance and the capacitance value with respect to the MFC design conditions (biocatalyst existence and electrode area) and operating parameters (acetate concentration and buffer strength in the catholyte) were then determined to elucidate the validity of the proposed method. This model was able to describe the dynamic behavior of the MFC during current change in the activation loss region; having an R(2) value of over 0.99 in most tests. Variations of the charge transfer resistance value (thousands of Omega) according to the change of the design factors and operational factors were well-correlated with the corresponding MFC performances. However, though the capacitance values (approximately 0.02 F) reflected the expected trend according to the electrode area change and catalyst property, they did not show significant variation with changes in either the acetate concentration or buffer strength. (c) 2009 Elsevier B.V. All rights reserved.

  1. Distribution of virulence determinants among antimicrobial-resistant and antimicrobial-susceptible Escherichia coli implicated in urinary tract infections.

    Science.gov (United States)

    Stephenson, Sam; Brown, P D

    2016-01-01

    Uropathogenic Escherichia coli (UPEC) rely on the correlation of virulence expression with antimicrobial resistance to persist and cause severe urinary tract infections (UTIs). We assessed the virulence pattern and prevalence among UPEC strains susceptible and resistant to multiple antimicrobial classes. A total of 174 non-duplicate UPEC strains from patients with clinically significant UTIs were analysed for susceptibility to aminoglycoside, antifolate, cephalosporin, nitrofuran and quinolone antibiotics for the production of extended-spectrum β-lactamases and for the presence of six virulence determinants encoding adhesins (afimbrial, Type 1 fimbriae, P and S-fimbriae) and toxins (cytotoxic necrotising factor and haemolysin). Relatively high resistance rates to nalidixic acid, ciprofloxacin, cephalothin and trimethoprim-sulfamethoxazole (82%, 78%, 62% and 59%, respectively) were observed. Fourteen distinct patterns were identified for the virulence determinants such as afaBC, cnfI, fimH, hylA, papEF and sfaDE. The toxin gene, cnfI (75.3%), was the second most prevalent marker to the adhesin, fimH (97.1%). The significant association of sfaDE/hylA (P < 0.01) among antimicrobial resistant and susceptible strains was also observed notwithstanding an overall greater occurrence of virulence factors among the latter. This study provides a snapshot of UPEC complexity in Jamaica and highlights the significant clonal heterogeneity among strains. Such outcomes emphasise the need for evidence-based strategies in the effective management and control of UTIs.

  2. Genome-wide and expression-profiling analyses suggest the main cytochrome P450 genes related to pyrethroid resistance in the malaria vector, Anopheles sinensis (Diptera Culicidae).

    Science.gov (United States)

    Yan, Zheng-Wen; He, Zheng-Bo; Yan, Zhen-Tian; Si, Feng-Ling; Zhou, Yong; Chen, Bin

    2018-02-02

    Anopheles sinensis is one of the major malaria vectors. However, pyrethroid resistance in An. sinensis is threatening malaria control. Cytochrome P450-mediated detoxification is an important pyrethroid resistance mechanism that has been unexplored in An. sinensis. In this study, we performed a comprehensive analysis of the An. sinensis P450 gene superfamily with special attention to their role in pyrethroid resistance using bioinformatics and molecular approaches. Our data revealed the presence of 112 individual P450 genes in An. sinensis, which were classified into four major clans (mitochondrial, CYP2, CYP3 and CYP4), 18 families and 50 subfamilies. Sixty-seven genes formed nine gene clusters, and genes within the same cluster and the same gene family had a similar gene structure. Phylogenetic analysis showed that most of An. sinensis P450s (82/112) had very close 1: 1 orthology with Anopheles gambiae P450s. Five genes (AsCYP6Z2, AsCYP6P3v1, AsCYP6P3v2, AsCYP9J5 and AsCYP306A1) were significantly upregulated in three pyrethroid-resistant populations in both RNA-seq and RT-qPCR analyses, suggesting that they could be the most important P450 genes involved in pyrethroid resistance in An. sinensis. Our study provides insight on the diversity of An. sinensis P450 superfamily and basis for further elucidating pyrethroid resistance mechanism in this mosquito species. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  3. Determining resistance to mastitis in a bovine subject involves detecting presence or absence of genetic marker associated with trait indicative of mastitis resistance of the bovine subject and/or off-spring from it

    DEFF Research Database (Denmark)

    2010-01-01

    NOVELTY - Determining (m1) resistance to mastitis in a bovine subject, involves detecting in a sample from the bovine subject the presence or absence of at least one genetic marker that is associated with at least one trait indicative of mastitis resistance of the bovine subject and/or off......-spring from it, where the genetic marker is located on the bovine chromosome BTA11 in the region flanked by and including the zeta-chain associated protein 70kD (ZAP70) and CD8B genes, where the presence or absence of the genetic marker is indicative of mastitis resistance. USE - For determining resistance...... to mastitis in a bovine subject for determining mastitis resistance in a bovine subject; for detecting the presence or absence in a bovine subject of at least one genetic marker associated with resistance to mastitis; and for estimating breeding value in respect of susceptibility to mastitis in a bovine...

  4. Electrical resistance determination of actual contact area of cold welded metal joints

    Science.gov (United States)

    Hordon, M. J.

    1970-01-01

    Method measures the area of the bonded zone of a compression weld by observing the electrical resistance of the weld zone while the load changes from full compression until the joint ruptures under tension. The ratio of bonding force to maximum tensile load varies considerably.

  5. Resistance of Gram-positive bacteria to nisin is not determined by Lipid II levels

    NARCIS (Netherlands)

    Kramer, NE; Smid, EJ; Kok, J; de Kruijff, B; Kuipers, OP; Breukink, E; Kramer, Naomi E.; Smid, Eddy J.

    2004-01-01

    Lipid II is essential for nisin-mediated pore formation at nano-molar concentrations. We tested whether nisin resistance could result from different Lipid II levels, by comparing the maximal Lipid II pool in Micrococcus flavus (sensitive) and Listeria monocytogenes (relatively insensitive) and their

  6. Pea weevil damage and chemical characteristics of pea cultivars determining their resistance to Bruchus pisorum L.

    Science.gov (United States)

    Nikolova, I

    2016-04-01

    Bruchus pisorum (L.) is one of the most intractable pest problems of cultivated pea in Europe. Development of resistant cultivars is very important to environmental protection and would solve this problem to a great extent. Therefore, the resistance of five spring pea cultivars was studied to B. pisorum: Glyans, Modus; Kamerton and Svit and Pleven 4 based on the weevil damage and chemical composition of seeds. The seeds were classified as three types: healthy seeds (type one), damaged seeds with parasitoid emergence holes (type two) and damaged seeds with bruchid emergence holes (type three). From visibly damaged pea seeds by pea weevil B. pisorum was isolated the parasitoid Triaspis thoracica Curtis (Hymenoptera, Braconidae). Modus, followed by Glyans was outlined as resistant cultivars against the pea weevil. They had the lowest total damaged seed degree, loss in weight of damaged seeds (type two and type three) and values of susceptibility coefficients. A strong negative relationship (r = -0.838) between the weight of type one seeds and the proportion of type three seeds was found. Cultivars with lower protein and phosphorus (P) content had a lower level of damage. The crude protein, crude fiber and P content in damaged seeds significantly or no significantly were increased as compared with the healthy seeds due to weevil damage. The P content had the highest significant influence on pea weevil infestation. Use of chemical markers for resistance to the creation of new pea cultivars can be effective method for defense and control against B. pisorum.

  7. An in vitro study to determine fracture resistance of tooth roots after different instrumentation techniques

    Directory of Open Access Journals (Sweden)

    Marri Shilpa Reddy

    2016-01-01

    Conclusion: Preparation of canals with a conventional hand instrumentation technique using 0.02 taper K-files showed highest fracture resistance with least amount of dentin removed at all levels followed by Endowave, ProTaper Hand, and Rotary files.

  8. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Glaysher, Sharon; Modi, Paul; Rahamim, Joe; Smith, Mark E; Amer, Khalid; Addis, Bruce; Poole, Matthew; Narayanan, Ajit; Gulliford, Tim J; Andreotti, Peter E; Cree, Ian A; Yiannakis, Dennis; Gabriel, Francis G; Johnson, Penny; Polak, Marta E; Knight, Louise A; Goldthorpe, Zoe; Peregrin, Katharine; Gyi, Mya

    2009-01-01

    NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA) and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE) tissue. There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer

  9. Resistance gene expression determines the in vitro chemosensitivity of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Amer Khalid

    2009-08-01

    Full Text Available Abstract Background NSCLC exhibits considerable heterogeneity in its sensitivity to chemotherapy and similar heterogeneity is noted in vitro in a variety of model systems. This study has tested the hypothesis that the molecular basis of the observed in vitro chemosensitivity of NSCLC lies within the known resistance mechanisms inherent to these patients' tumors. Methods The chemosensitivity of a series of 49 NSCLC tumors was assessed using the ATP-based tumor chemosensitivity assay (ATP-TCA and compared with quantitative expression of resistance genes measured by RT-PCR in a Taqman Array™ following extraction of RNA from formalin-fixed paraffin-embedded (FFPE tissue. Results There was considerable heterogeneity between tumors within the ATP-TCA, and while this showed no direct correlation with individual gene expression, there was strong correlation of multi-gene signatures for many of the single agents and combinations tested. For instance, docetaxel activity showed some dependence on the expression of drug pumps, while cisplatin activity showed some dependence on DNA repair enzyme expression. Activity of both drugs was influenced more strongly still by the expression of anti- and pro-apoptotic genes by the tumor for both docetaxel and cisplatin. The doublet combinations of cisplatin with gemcitabine and cisplatin with docetaxel showed gene expression signatures incorporating resistance mechanisms for both agents. Conclusion Genes predicted to be involved in known mechanisms drug sensitivity and resistance correlate well with in vitro chemosensitivity and may allow the definition of predictive signatures to guide individualized chemotherapy in lung cancer.

  10. Phylogenetic relatedness determined between antibiotic resistance and 16S rRNA genes in actinobacteria.

    Science.gov (United States)

    Sagova-Mareckova, Marketa; Ulanova, Dana; Sanderova, Petra; Omelka, Marek; Kamenik, Zdenek; Olsovska, Jana; Kopecky, Jan

    2015-04-01

    Distribution and evolutionary history of resistance genes in environmental actinobacteria provide information on intensity of antibiosis and evolution of specific secondary metabolic pathways at a given site. To this day, actinobacteria producing biologically active compounds were isolated mostly from soil but only a limited range of soil environments were commonly sampled. Consequently, soil remains an unexplored environment in search for novel producers and related evolutionary questions. Ninety actinobacteria strains isolated at contrasting soil sites were characterized phylogenetically by 16S rRNA gene, for presence of erm and ABC transporter resistance genes and antibiotic production. An analogous analysis was performed in silico with 246 and 31 strains from Integrated Microbial Genomes (JGI_IMG) database selected by the presence of ABC transporter genes and erm genes, respectively. In the isolates, distances of erm gene sequences were significantly correlated to phylogenetic distances based on 16S rRNA genes, while ABC transporter gene distances were not. The phylogenetic distance of isolates was significantly correlated to soil pH and organic matter content of isolation sites. In the analysis of JGI_IMG datasets the correlation between phylogeny of resistance genes and the strain phylogeny based on 16S rRNA genes or five housekeeping genes was observed for both the erm genes and ABC transporter genes in both actinobacteria and streptomycetes. However, in the analysis of sequences from genomes where both resistance genes occurred together the correlation was observed for both ABC transporter and erm genes in actinobacteria but in streptomycetes only in the erm gene. The type of erm resistance gene sequences was influenced by linkage to 16S rRNA gene sequences and site characteristics. The phylogeny of ABC transporter gene was correlated to 16S rRNA genes mainly above the genus level. The results support the concept of new specific secondary metabolite

  11. Genome-Wide High-Throughput Screening to Investigate Essential Genes Involved in Methicillin-Resistant Staphylococcus aureus Sequence Type 398 Survival

    DEFF Research Database (Denmark)

    Christiansen, Mette Theilgaard; Kaas, Rolf Sommer; Chaudhuri, Roy R.

    2014-01-01

    Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) Sequence Type 398 (ST398) is an opportunistic pathogen that is able to colonize and cause disease in several animal species including humans. To better understand the adaptation, evolution, transmission and pathogenic...

  12. Genome-wide association study for Identification and validation of novel SNP markers for Sr6 stem rust resistance gene in bread wheat

    Science.gov (United States)

    Stem rust (caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn.), is a major disease in wheat (Triticum aestivium L.). However, in recent years it occurs rarely in Nebraska due to weather and the effective selection and gene pyramiding of resistance genes. To understand the genetic basis of...

  13. Empirical ranking of a wide range of WC-Co grades in terms of their abrasion resistance measured by the ASTM standard B 611-85 test

    CSIR Research Space (South Africa)

    O'Quigley, DGF

    1997-01-01

    Full Text Available This paper reports the results of a comprehensive investigation into the abrasion resistance of WC-Co alloys, as measured by the ASTM Standard B 611-85 test. The alloys ranged from 3 to 50 wt% and from 0.6 to 5 mu-m average grain size. Careful...

  14. Electric resistivity distribution in the Earth's crust and upper mantle for the southern East European Platform and Crimea from area-wide 2D models

    Science.gov (United States)

    Logvinov, Igor M.; Tarasov, Viktor N.

    2018-03-01

    Previously obtained magnetotelluric 2D models for 30 profiles made it possible to create an overview model of electric resistivity for the territory between 28°E and 36°E and between 44.5°N and 52.5°N. It allows us to distinguish a number of low resistivity objects (LRO) with resistivities lower than 100 Ω m the Earth's crust and mantle. Two regional conductivity anomalies are traced. The Kirovograd conductivity anomaly extends south to the Crimea mountains. A new regional conductivity anomaly (Konkskaya) can be distinguished along the southern slope of the Ukrainian Shield from 29° to 34°E. In addition, many local LROs have been identified. According to the modeling results, the local low resistivity objects on the East European Platform appear along fault zones activated during last 5-7 M years and the model suggests their relation to known zones of graphitization and polymetallic ore deposits. Local LROs in the Dnieper-Donets Basin correlate with the main oil and natural gas fields in this area. The depth of the anomalous objects amounts to 5-22 km. This is consistent with the hypotheses that hydrocarbon deposits are related to generation and transport zones of carbon-bearing fluids.

  15. Genome-Wide Identification of Chalcone Reductase Gene Family in Soybean: Insight into Root-Specific GmCHRs and Phytophthora sojae Resistance

    Directory of Open Access Journals (Sweden)

    Caroline J. Sepiol

    2017-12-01

    Full Text Available Soybean (Glycine max [L.] Merr is one of the main grain legumes worldwide. Soybean farmers lose billions of dollars’ worth of yield annually due to root and stem rot disease caused by the oomycete Phytophthora sojae. Many strategies have been developed to combat the disease, however, these methods have proven ineffective in the long term. A more cost effective and durable approach is to select a trait naturally found in soybean that can increase resistance. One such trait is the increased production of phytoalexin glyceollins in soybean. Glyceollins are isoflavonoids, synthesized via the legume-specific branch of general phenylpropanoid pathway. The first key enzyme exclusively involved in glyceollin synthesis is chalcone reductase (CHR which coacts with chalcone synthase for the production of isoliquiritigenin, the precursor for glyceollin biosynthesis. Here we report the identification of 14 putative CHR genes in soybean where 11 of them are predicted to be functional. Our results show that GmCHRs display tissue-specific gene expression, and that only root-specific GmCHRs are induced upon P. sojae infection. Among 4 root-specific GmCHRs, GmCHR2A is located near a QTL that is linked to P. sojae resistance suggesting GmCHR2A as a novel locus for partial resistance that can be utilized for resistance breeding.

  16. Genome-wide sequencing and an open reading frame analysis of dichlorodiphenyltrichloroethane (DDT) susceptible (91-C) and resistant (91-R) Drosophila melanogaster laboratory populations

    Science.gov (United States)

    The Drosophila melanogaster 91-R and 91-C strains are of common origin, however, 91-R has been intensely selected for dichlorodiphenyltrichloroethane (DDT) resistance over six decades while 91-C has been maintained as the non-selected control strain. These fly strains represent a unique genetic res...

  17. Enterococcus spp. Resistant to Multiple Antimicrobial Drugs and Determination of Fecal Contamination Levels in Mangrove Oysters (Crassostrea rhizophorae)

    OpenAIRE

    Rubião, Cynthia Annes; Franco, Robson Maia; Mesquita, Eliana de Fátima Marques de; Miguel, Marco Antonio Lemos; Cabral, Claudius Couto; Fonseca, Ana Beatriz Monteiro

    2017-01-01

    ABSTRACT The aim of this study was to determine and compare the Most Probable Number (MPN) of Total Coliforms (TC), Escherichia coli and Enterococcus spp. and to characterize the antimicrobial resistance profiles of Enterococcus spp. isolated from oysters collected in the Barra de Guaratiba Mangrove, Rio de Janeiro, Brazil. The enumeration of E. coli has been used to indicate fecal contamination and hygienic-sanitary conditions of bivalve molluscs. Enterococci are capable to transfer several ...

  18. Impact determination of strength and resistance training on Glycoside hemoglobin and blood sugar on patients with type II diabetes”

    OpenAIRE

    Bahman Hasanvand; Kobra Karami; Abdollah Khodadi; Mehdi Valipour

    2011-01-01

    Background : This study determined the impact of strength and resistance training on hemoglobin Glycoside and glucose in type II diabetic patients in Khorramabad in 2009. Materials and Methods: This quasi-experimental study was carried out on 30 men with type 2 diabetes referred to laboratories in Khorramabad, selected by screening and interview and purposeful sampling . After the subjects completed questionnaires of medical records and written consent, they were randomly divided into th...

  19. Resistivity method contribution in determining of fault zone and hydro-geophysical characteristics of carbonate aquifer, eastern desert, Egypt

    Science.gov (United States)

    Ammar, A. I.; Kamal, K. A.

    2018-03-01

    Determination of fault zone and hydro-geophysical characteristics of the fractured aquifers are complicated, because their fractures are controlled by different factors. Therefore, 60 VESs were carried out as well as 17 productive wells for determining the locations of the fault zones and the characteristics of the carbonate aquifer at the eastern desert, Egypt. The general curve type of the recorded rock units was QKH. These curves were used in delineating the zones of faults according to the application of the new assumptions. The main aquifer was included at end of the K-curve type and front of the H-curve type. The subsurface layers classified into seven different geoelectric layers. The fractured shaly limestone and fractured limestone layers were the main aquifer and their resistivity changed from low to medium (11-93 Ω m). The hydro-geophysical properties of this aquifer such as the areas of very high, high, and intermediate fracture densities of high groundwater accumulations, salinity, shale content, porosity distribution, and recharging and flowing of groundwater were determined. The statistical analysis appeared that depending of aquifer resistivity on the water salinities (T.D.S.) and water resistivities add to the fracture density and shale content. The T.D.S. increasing were controlled by Na+, Cl-, Ca2+, Mg2+, and then (SO4)2-, respectively. The porosity was calculated and its average value was 19%. The hydrochemical analysis of groundwater appeared that its type was brackish and the arrangements of cation concentrations were Na+ > Ca2+ > Mg2+ > K+ and anion concentrations were Cl- > (SO4)2- > HCO3 - > CO3 -. The groundwater was characterized by sodium-bicarbonate and sodium-sulfate genetic water types and meteoric in origin. Hence, it can use the DC-resistivity method in delineating the fault zone and determining the hydro-geophysical characteristics of the fractured aquifer with taking into account the quality of measurements and interpretation.

  20. Identification of Loci Associated with Drought Resistance Traits in Heterozygous Autotetraploid Alfalfa (Medicago sativa L.) Using Genome-Wide Association Studies with Genotyping by Sequencing.

    Science.gov (United States)

    Zhang, Tiejun; Yu, Long-Xi; Zheng, Ping; Li, Yajun; Rivera, Martha; Main, Dorrie; Greene, Stephanie L

    2015-01-01

    Drought resistance is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. Identification of genes involved in drought tolerance will facilitate breeding for improving drought resistance and water use efficiency in alfalfa. Our objective was to use a diversity panel of alfalfa accessions comprised of 198 cultivars and landraces to identify genes involved in drought tolerance. The panel was selected from the USDA-ARS National Plant Germplasm System alfalfa collection and genotyped using genotyping by sequencing. A greenhouse procedure was used for phenotyping two important traits associated with drought tolerance: drought resistance index (DRI) and relative leaf water content (RWC). Marker-trait association identified nineteen and fifteen loci associated with DRI and RWC, respectively. Alignments of target sequences flanking to the resistance loci against the reference genome of M. truncatula revealed multiple chromosomal locations. Markers associated with DRI are located on all chromosomes while markers associated with RWC are located on chromosomes 1, 2, 3, 4, 5, 6 and 7. Co-localizations of significant markers between DRI and RWC were found on chromosomes 3, 5 and 7. Most loci associated with DRI in this work overlap with the reported QTLs associated with biomass under drought in alfalfa. Additional significant markers were targeted to several contigs with unknown chromosomal locations. BLAST search using their flanking sequences revealed homology to several annotated genes with functions in stress tolerance. With further validation, these markers may be used for marker-assisted breeding new alfalfa varieties with drought resistance and enhanced water use efficiency.

  1. Determination of antimicrobial and heavy metal resistance profiles of some bacteria isolated from aquatic amphibian and reptile species.

    Science.gov (United States)

    Hacioglu, Nurcihan; Tosunoglu, Murat

    2014-01-01

    The aim of the present study was to determine the level of antibiotic resistance patterns and distribution of heavy metal resistance of bacterial isolates from aquatic animals (Lissotriton vulgaris, Pelophylax ridibundus, Emys orbicularis, Mauremys rivulata, and Natrix natrix) in Turkey (Kavak Delta). A total of 153 bacteria have been successfully isolated from cloaca and oral samples of the aquatic amphibians and reptilians which were found, namely, Aeromonas sp. (n = 29), Plesiomonas sp. (n = 7), Vibrio sp. (n = 12), Citrobacter sp. (n = 12), Enterobacter sp. (n = 11), Escherichia sp. (n = 22), Klebsiella sp. (n = 22), Edwardsiella sp. (n = 6), Hafnia sp. (n = 1), Proteus sp. (n = 19), Providencia sp. (n = 8), and Pseudomonas sp. (n = 4). In terms of antibiotic and heavy metal susceptibility testing, each isolate was tested against 12 antibiotics and 4 metals. There was a high incidence of resistance to cefoxitin (46.40 %), ampicillin (44.44 %), erythromycin (35.29 %), and a low incidence of resistance to gentamicin (6.53 %), kanamycin (8.49 %), chloramphenicol (9.15 %), and cefotaxime (10.45 %). The multiple antibiotic resistance index of each bacterial species indicated that bacteria from raised amphibians and reptiles have been exposed to tested antibiotics, with results ranging from 0 to 0.58. Most isolates showed tolerance to different concentrations of heavy metals, and minimal inhibition concentrations ranged from100 to >3,200 μg/mL. According to these results, a significant occurrence of bacteria in the internal organs of reptiles and amphibians, with a high incidence of resistance against antibiotics and heavy metals, may risk aquatic animals and the public health. These data appoint the importance of epidemiological surveillance and microbiological monitoring and reinforce the need to implement environment protection programs for amphibian and reptile species.

  2. Prevalence of virulence determinants and antimicrobial resistance among commensal Escherichia coli derived from dairy and beef cattle.

    Science.gov (United States)

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-19

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  3. Typing of Staphylococcus aureus in order to determine the spread of drug resistant strains inside and outside hospital environment.

    Science.gov (United States)

    Pobiega, Monika; Wójkowska-Mach, Jadwiga; Heczko, Piotr B

    2013-01-01

    Staphylococcus aureus is one of the most important etiological factors of both nosocomial and community-acquired infections. Multidrug-resistant S. aureus is frequently isolated nowadays. Antibiotics used on the hospital ward exert a selective pressure on the strains and favor resistant strains. Multidrug-resistant and highly virulent strains can spread not only within the hospital but also between hospitals. Numerous studies show a predominance of one clone on a specific territory. The spread of such dangerous clones to neighboring countries and the entire continent is possible. Typing methods are very useful in infection control and prevention. Modern methods which are based on sequencing are necessary in rationalizing of infection control programs. Typing of Staphylococcus aureus includes methods that allow to determine the spread of drug-resistant pathogens. 'Gold standard' is pulsed-field gel electrophoresis (PFGE), which relies on separating the DNA fragments after restriction cutting. MLST (Multi Locus Sequence Typing) is based on a comparison of"housekeeping" gene sequences controlling the basic cell functions. With the MLST method, it is possible to demonstrate a broad, international spread of the specific clones. However, for epidemiological investigations, MLST seems to be too time-consuming and expensive to be used as a basic typing tool. The complementary method is spa typing, based on the sequencing of short repetitive sequences of the polymorphic X region from the gene encoding protein A. This method can be used for studying molecular evolution of S. aureus, as well as for testing for hospital outbreaks. It is faster and cheaper than MLST. It is also necessary to subtype the elements responsible for methycillin resistance (SCCmec), which allows to distinguish MRSA (Methicillin-resistant Staphylococcus aureus) clones with a common ancestor, but different epidemiological origin. All of those methods have their specific advantages and disadvantages and

  4. A method to determine the kink resistance of stents and stent delivery systems according to international standards

    Directory of Open Access Journals (Sweden)

    Brandt-Wunderlich Christoph

    2016-09-01

    Full Text Available The kink behavior of vascular stents is of particular interest for clinicians, stent manufacturers and regulatory as a kinked stent generates a lumen loss in the stented vessel and can lead to in-stent restenosis. In this study methods to determine the kink resistance of stents and stent delivery systems according to the ISO 25539-2 and FDA guidance no. 1545 were presented. The methods are applicable for balloon expandable stents as well as for self-expanding stents and determine the lumen loss and residual diameter change dependent on the specific bending radius.

  5. A Wide Linearity Range Method for the Determination of Lenalidomide in Plasma by High-Performance Liquid Chromatography: Application to Pharmacokinetic Studies.

    Science.gov (United States)

    Guglieri-López, Beatriz; Pérez-Pitarch, Alejandro; Martinez-Gómez, Maria Amparo; Porta-Oltra, Begoña; Climente-Martí, Mónica; Merino-Sanjuán, Matilde

    2016-12-01

    A wide linearity range analytical method for the determination of lenalidomide in patients with multiple myeloma for pharmacokinetic studies is required. Plasma samples were ultrasonicated for protein precipitation. A solid-phase extraction was performed. The eluted samples were evaporated to dryness under vacuum, and the solid obtained was diluted and injected into the high-performance liquid chromatography (HPLC) system. Separation of lenalidomide was performed on an Xterra RP C18 (250 mm length × 4.6 mm i.d., 5 µm) using a mobile phase consisting of phosphate buffer/acetonitrile (85:15, v/v, pH 3.2) at a flow rate of 0.5 mL · min -1 The samples were monitored at a wavelength of 311 nm. A linear relationship with good correlation coefficient (r = 0.997, n = 9) was found between the peak area and lenalidomide concentrations in the range of 100 to 950 ng · mL -1 The limits of detection and quantitation were 28 and 100 ng · mL -1 , respectively. The intra- and interassay precisions were satisfactory, and the accuracy of the method was proved. In conclusion, the proposed method is suitable for the accurate quantification of lenalidomide in human plasma with a wide linear range, from 100 to 950 ng · mL -1 This is a valuable method for pharmacokinetic studies of lenalidomide in human subjects. © 2016 Society for Laboratory Automation and Screening.

  6. Report on the IAEA-CU-2006-03 world-wide open proficiency test on the determination of gamma emitting radionuclides

    International Nuclear Information System (INIS)

    Shakhashiro, A.; Sansone, U.; Trinkl, A.; Makarewicz, M.; Yonezawa, C.; Kim, C.K.; Kis-Benedek, G.; Benesch, T.; Schorn, R.

    2007-05-01

    The results of analytical measurements play a vital role in our daily lives. Analytical data may be the basis upon which economic, legal or environmental management decisions are made, and they are essential in international trade, environmental protection, safe transportation, law enforcement, consumer safety and the preservation of human health. As an incorrect decision can be extremely costly and detrimental, it is essential that such measurements are accurate, reliable, cost effective and defensible. In addition, measurements performed by laboratories located worldwide should yield traceable and comparable results. Proficiency testing is a method for regularly assessing the accuracy of the analytical data produced by the laboratories of particular measurements. The IAEA-CU-2006-03 world-wide proficiency test (PT) on the determination of gamma emitting radionuclides in water grass and soil is conducted by the Chemistry Unit of the IAEA's Laboratories located in Seibersdorf (Austria), which is actively involved in the production and characterization of matrix reference materials of terrestrial origin, widely used for method validation and organization of proficiency tests and intercomparison studies. The Chemistry Unit is a part of the Physics, Chemistry and Instrumentation Laboratory. This report describes the sample preparation methodology, data evaluation approach, summary evaluation of each nuclide and individual evaluation report for each laboratory

  7. Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

    Science.gov (United States)

    McDougal, Chris; Eberhart, Chad; Lee, Erik

    2016-01-01

    Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

  8. Use of P-32 for determining varietal resistance of rice to brown planthopper (Nilaparvata lugens stal)

    Energy Technology Data Exchange (ETDEWEB)

    Kuswadi, A.N. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

    1981-07-01

    The resistance was assessed based on the feeding activities of the insect on 15-day old seedling of six test varieties namely TN 1, Asahan, Brantas, Citarum, Serayu and Mudgo. A level of 175 ..mu..Ci per seedling appeared to give sufficiently high absorption of radiophosphorus by the brown planthoppers. The level of radioactivity in the brown planthopper fed for 24 hours on labelled rice plants appeared to be correlated with the susceptibility of the rice plant to brown planthopper. The radioactivity in the honeydew of those hoppers was less correlated with the rice susceptibility. The promising resistance screening method using P-32 tracer is thus more reliable when the radioactivity is detected in the insect rather than in the honeydew.

  9. Experimental Determination of Frost Resistance of Autoclaved Aerated Concrete at Different Levels of Moisture Saturation

    Science.gov (United States)

    Kočí, Václav; Maděra, Jiří; Jerman, Miloš; Černý, Robert

    2018-06-01

    The ability of porous building materials to stand up to moisture phase changes induced by alternating environment is described mostly by means of their frost resistance. However, the test conditions defined by relevant standards might not capture the real situation on building site in various locations. In particular, the prescribed full water saturation of analyzed specimens during the whole time of a freeze/thaw experiment presents an ultimate case only but certainly not an everyday reality. Even the materials of surface layers are mostly exposed to such severe conditions just for a limited period of time. In this paper, the experimental analysis of frost resistance of three different types of autoclaved aerated concrete (AAC) is performed in an extended way, including not only the standard testing but also the investigation of dry- and partially saturated samples. A complementary computational analysis of an AAC building envelope in Central European climate is presented as well, in order to illustrate the likely hygric conditions in the wall. Experimental results show that according to the standard test the loss of compressive strength, as well as the loss of mass after 25 cycles, is acceptable for all studied samples but after 50 cycles only the material with the compressive strength of 4 MPa performs satisfactorily. On the other hand, the tests with initially dried or partially saturated samples indicate a good frost resistance of all studied materials for both 25 and 50 cycles.

  10. Environmental determinants of type 1 diabetes: a role for overweight and insulin resistance.

    Science.gov (United States)

    Islam, Sadia T; Srinivasan, Shubha; Craig, Maria E

    2014-11-01

    Rates of type 1 diabetes are rising globally, with a decreasing proportion of high-risk genotypes and twin concordance rates below 50%. Therefore, environmental factors such as viruses, nutrition and overweight have been examined as putative aetiological agents. The accelerator hypothesis proposes that overweight and insulin resistance are central to both type 1 and type 2 diabetes and may explain, in part, the rise in type 1 diabetes incidence. The temporal rise in body mass index at type 1 diabetes onset and the observation that pre-diabetic children are heavier and more insulin resistant than their peers suggests convergence of type 1 and type 2 diabetes phenotypes. The influence of insulin resistance may begin in utero, although the aetiological role of birthweight in type 1 diabetes remains unclear. Further research to elucidate the role of these modifiable risk factors in today's obesogenic environment may provide future potential for diabetes prevention. © 2014 The Authors. Journal of Paediatrics and Child Health © 2014 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  11. Study on contamination of sheep meat in Shahrekord area with Listeria ivanovii and determination its antibiotic resistance pattern

    Directory of Open Access Journals (Sweden)

    Farid Khalili Borujeni

    2013-06-01

    Full Text Available Background and objectives: Listeria monocytogenes and Listeria ivanovii are two pathogenic species of Listeria. The role of Listeria ivanovii is important in abortion, stillbirth, septicemia in animals and this bacterium sometimes is pathogenic in humans. Contamination of ovine carcasses during the slaughter and processing can cause foodborne infections in humans. In this study we examined the contamination of sheep meat in slaughter house of Shahrekord city to Listeria ivanovii and determined its antibiotic resistance pattern.Material and Methods: A total 200 samples of sheep meat were collected from abattoir and processed by use of two enrichment method. After doing specific biochemical tests and PCR, Listeria spp was identified and antibiotic resistance of isolated Listeria were tested by the agar disc diffusion method. Results: The contamination of sheep carcasses with listeria was 2.5% (5 out of 200 samples. All five isolates (2.5% were recognized as Listeria ivanovii and were resistant to four antibiotics, sensitive to six antibiotics and intermediate to other antibiotics.  Conclusion: According to the contamination rate in sheep carcasses with Listeria ivanovii and the relatively high antibiotic resistance specified in this bacteria, the role of red meat in transmission of Listeria spp. and appropriate use of antibiotics against this bacteria should be considered.

  12. The survey of shigellosis frequency and determination of antibiotic resistance profile of isolated strains from infected children in Tehran

    Directory of Open Access Journals (Sweden)

    Shahla Abbaspour

    2014-04-01

    Full Text Available Background: Shigellosis is endemic throughout the world and it is among the most common causes of bacterial diarrheal diseases. Antibiotic resistance of Shigella is becoming a progressive problem in world. The aim of this study was the survey of shigellosis frequency and determination of antibiotic resistance profile of isolated strains from infected children in Tehran. Material and Methods: This study conducted on 9131 patients with acute diarrheal disease. For isolation of Shigella spp. from stool samples, culture performed on different selective and differential media. After confirmation of bacteria by biochemical tests, susceptibility testing was done by disc diffusion method according to clinical and laboratory standards (CLSI recomendations. Results: Among 9131 stool samples, Shigella spp. was isolated from 90 cases. Shigella sonnei was the most common isolated species. 92/2 % of isolates were resistant to cotrimoxazole. In contrast, most of the Shigella spp. was founded to be sensitive to ciprofloxacin, imipenem and third-generation cephalosporins. Conclusion: Surveillance programs on antimicrobial resistance not only identify pathogenic bacterial species, by reporting data like serotyping, microorganisms incidence rates, and susceptibility to the antimicrobial agents currently used for treatment, but also contribute to monitoring the intervention strategies including removing organism from reservoirs.

  13. Preliminary report for analysis of genome wide mutations from four ciprofloxacin resistant B. anthracis Sterne isolates generated by Illumina, 454 sequencing and microarrays for DHS

    Energy Technology Data Exchange (ETDEWEB)

    Jaing, Crystal [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vergez, Lisa [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hinckley, Aubree [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thissen, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gardner, Shea [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McLoughlin, Kevin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jackson, Paul [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ellingson, Sally [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hauser, Loren [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Brettin, Tom [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Fofanov, Viacheslav [Eureka Genomics, Hercules, CA (United States); Koshinsky, Heather [Eureka Genomics, Hercules, CA (United States); Fofanov, Yuriy [Univ. of Houston, TX (United States)

    2011-06-21

    The objective of this project is to provide DHS a comprehensive evaluation of the current genomic technologies including genotyping, Taqman PCR, multiple locus variable tandem repeat analysis (MLVA), microarray and high-throughput DNA sequencing in the analysis of biothreat agents from complex environmental samples. As the result of a different DHS project, we have selected for and isolated a large number of ciprofloxacin resistant B. anthracis Sterne isolates. These isolates vary in the concentrations of ciprofloxacin that they can tolerate, suggesting multiple mutations in the samples. In collaboration with University of Houston, Eureka Genomics and Oak Ridge National Laboratory, we analyzed the ciprofloxacin resistant B. anthracis Sterne isolates by microarray hybridization, Illumina and Roche 454 sequencing to understand the error rates and sensitivity of the different methods. The report provides an assessment of the results and a complete set of all protocols used and all data generated along with information to interpret the protocols and data sets.

  14. An alternative hypothesis to the widely held view that renal excretion of sodium accounts for resistance to salt-induced hypertension

    Czech Academy of Sciences Publication Activity Database

    Kurtz, T. W.; DiCarlo, S. E.; Pravenec, Michal; Schmidlin, O.; Tanaka, M.; Morris Jr., R. C.

    2016-01-01

    Roč. 90, č. 5 (2016), s. 965-973 ISSN 0085-2538 Grant - others:AV ČR(CZ) AP1502 Program:Akademická prémie - Praemium Academiae Institutional support: RVO:67985823 Keywords : blood pressure * hypertension * kidney * salt * salt-resistance * salt-sensitivity * sodium * sodium chloride Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 8.395, year: 2016

  15. [Determination of drug resistance mutations of NS3 inhibitors in chronic hepatitis C patients infected with genotype 1].

    Science.gov (United States)

    Şanlıdağ, Tamer; Sayan, Murat; Akçalı, Sinem; Kasap, Elmas; Buran, Tahir; Arıkan, Ayşe

    2017-04-01

    Direct-acting antiviral agents (DAA) such as NS3 protease inhibitors is the first class of drugs used for chronic hepatitis C (CHC) treatment. NS3 inhibitors (PI) with low genetic barrier have been approved to be used in the CHC genotype 1 infections, and in the treatment of compensated liver disease including cirrhosis together with pegile interferon and ribavirin. Consequently, the development of drug resistance during DAA treatment of CHC is a major problem. NS3 resistant variants can be detected before treatment as they can occurnaturally. The aim of this study was to investigate new and old generation NS3 inhibitors resistance mutations before DAA treatment in hepatitis C virus (HCV) that were isolated from CHC. The present study was conducted in 2015 and included 97 naive DAA patients infected with HCV genotype 1, who were diagnosed in Manisa and Kocaeli cities of Turkey. Magnetic particle based HCV RNA extraction and than RNA detection and quantification were performed using commercial real-time PCR assay QIASypmhony + Rotorgene Q/ArtusHCV QS-RGQ and COBAS Ampliprep/COBAS TaqMan HCV Tests. HCV NS3 viral protease genome region was amplified with PCR and mutation analysis was performed by Sanger dideoxy sequencing technique of NS3 protease codons (codon 32-185). HCV NS3 protease inhibitors; asunaprevir, boceprevir, faldaprevir, grazoprevir, pariteprevir, simeprevir and telaprevir were analysed for resistant mutations by Geno2pheno-HCV resistance tool. HCV was genotyped in all patients and 88 patients (n= 88/97, 91%) had genotype 1. Eight (n= 8/97, 8.2%) and 80 (n= 80/97, 82.4%) HCC patients were subgenotyped as 1a and 1b, respectively. Many aminoacid substitutions and resistance mutations were determined in 39/88 (44%) patients in the study group. Q80L, S122C/N, S138W were defined as potential substitutions (6/88 patients; 7%); R109K, R117C, S122G, I132V, I170V, N174S were described as potential resistance (34/88 patients; 39%); V36L, T54S, V55A, Q80H were

  16. Genome-wide identification of long non-coding RNA genes and their association with insecticide resistance and metamorphosis in diamondback moth, Plutella xylostella.

    Science.gov (United States)

    Liu, Feiling; Guo, Dianhao; Yuan, Zhuting; Chen, Chen; Xiao, Huamei

    2017-11-20

    Long non-coding RNA (lncRNA) is a class of noncoding RNA >200 bp in length that has essential roles in regulating a variety of biological processes. Here, we constructed a computational pipeline to identify lncRNA genes in the diamondback moth (Plutella xylostella), a major insect pest of cruciferous vegetables. In total, 3,324 lncRNAs corresponding to 2,475 loci were identified from 13 RNA-Seq datasets, including samples from parasitized, insecticide-resistant strains and different developmental stages. The identified P. xylostella lncRNAs had shorter transcripts and fewer exons than protein-coding genes. Seven out of nine randomly selected lncRNAs were validated by strand-specific RT-PCR. In total, 54-172 lncRNAs were specifically expressed in the insecticide resistant strains, among which one lncRNA was located adjacent to the sodium channel gene. In addition, 63-135 lncRNAs were specifically expressed in different developmental stages, among which three lncRNAs overlapped or were located adjacent to the metamorphosis-associated genes. These lncRNAs were either strongly or weakly co-expressed with their overlapping or neighboring mRNA genes. In summary, we identified thousands of lncRNAs and presented evidence that lncRNAs might have key roles in conferring insecticide resistance and regulating the metamorphosis development in P. xylostella.

  17. Analysis of β-Lactamase Resistance Determinants in Enterobacteriaceae from Chicago Children: a Multicenter Survey

    Science.gov (United States)

    Hujer, Andrea M.; Marshall, Steven H.; Domitrovic, T. Nicholas; Rudin, Susan D.; Zheng, Xiaotian; Qureshi, Nadia K.; Hayden, Mary K.; Scaggs, Felicia A.; Karadkhele, Anand; Bonomo, Robert A.

    2016-01-01

    Multidrug-resistant (MDR) Enterobacteriaceae infections are increasing in U.S. children; however, there is a paucity of multicentered analyses of antibiotic resistance genes responsible for MDR phenotypes among pediatric Enterobacteriaceae isolates. In this study, 225 isolates phenotypically identified as extended-spectrum β-lactamase (ESBL) or carbapenemase producers, recovered from children ages 0 to 18 years hospitalized between January 2011 and April 2015 at three Chicago area hospitals, were analyzed. We used DNA microarray platforms to detect ESBL, plasmid-mediated AmpC (pAmpC), and carbapenemase type β-lactamase (bla) genes. Repetitive-sequence-based PCR and multilocus sequence typing (MLST) were performed to assess isolate similarity. Plasmid replicon typing was conducted to classify plasmids. The median patient age was 4.2 years, 56% were female, and 44% presented in the outpatient setting. The majority (60.9%) of isolates were Escherichia coli and from urinary sources (69.8%). Of 225 isolates exhibiting ESBL- or carbapenemase-producing phenotypes, 90.7% contained a bla gene. The most common genotype was the blaCTX-M-1 group (49.8%); 1.8% were carbapenem-resistant Enterobacteriaceae (three blaKPC and one blaIMP). Overall, pAmpC (blaACT/MIR and blaCMY) were present in 14.2%. The predominant E. coli phylogenetic group was the virulent B2 group (67.6%) associated with ST43/ST131 (Pasteur/Achtman MLST scheme) containing the blaCTX-M-1 group (84%), and plasmid replicon types FIA, FII, and FIB. K. pneumoniae harboring blaKPC were non-ST258 with replicon types I1 and A/C. Enterobacter spp. carrying blaACT/MIR contained plasmid replicon FIIA. We found that β-lactam resistance in children is diverse and that certain resistance mechanisms differ from known circulating genotypes in adults in an endemic area. The potential impact of complex molecular types and the silent dissemination of MDR Enterobacteriaceae in a vulnerable population needs to be studied further

  18. Determination of the influence of dispersion pattern of pesticide-resistant individuals on the reliability of resistance estimates using different sampling plans.

    Science.gov (United States)

    Shah, R; Worner, S P; Chapman, R B

    2012-10-01

    Pesticide resistance monitoring includes resistance detection and subsequent documentation/ measurement. Resistance detection would require at least one (≥1) resistant individual(s) to be present in a sample to initiate management strategies. Resistance documentation, on the other hand, would attempt to get an estimate of the entire population (≥90%) of the resistant individuals. A computer simulation model was used to compare the efficiency of simple random and systematic sampling plans to detect resistant individuals and to document their frequencies when the resistant individuals were randomly or patchily distributed. A patchy dispersion pattern of resistant individuals influenced the sampling efficiency of systematic sampling plans while the efficiency of random sampling was independent of such patchiness. When resistant individuals were randomly distributed, sample sizes required to detect at least one resistant individual (resistance detection) with a probability of 0.95 were 300 (1%) and 50 (10% and 20%); whereas, when resistant individuals were patchily distributed, using systematic sampling, sample sizes required for such detection were 6000 (1%), 600 (10%) and 300 (20%). Sample sizes of 900 and 400 would be required to detect ≥90% of resistant individuals (resistance documentation) with a probability of 0.95 when resistant individuals were randomly dispersed and present at a frequency of 10% and 20%, respectively; whereas, when resistant individuals were patchily distributed, using systematic sampling, a sample size of 3000 and 1500, respectively, was necessary. Small sample sizes either underestimated or overestimated the resistance frequency. A simple random sampling plan is, therefore, recommended for insecticide resistance detection and subsequent documentation.

  19. Determination of tungsten in high-alloy steels and heat resisting alloys by isotope dilution-spark source mass spectrometry

    International Nuclear Information System (INIS)

    Saito, Morimasa; Yamada, Kei; Okochi, Haruno; Hirose, Fumio

    1983-01-01

    Tungsten in high-alloy steels and heat-resisting alloys was determined by isotope dilution method combined with spark source mass spectrometry by using 183 W enriched tungsten. The spike solution was prepared by fusing tungsten trioxide in sodium carbonate. A high-alloy steel sample was dissolved in the mixture of sulfuric acid and phosphoric acid together with the spike solution; a sample of heat resisting alloy was similarly dissolved in the mixture of hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. The solution was evaporated to give dense white fumes. Tungsten was separated from the residue by a conventional cinchonine salt-precipitation method. The salt was ignited, and the residue was mixed with graphite powder and pressed into electrodes. The isotope 183 W and 184 W were measured. The method was applied to the determination of tungsten in JSS and NBS standard high-alloy steels and JAERI standard nickel- and NBS standard cobalt-base heat resisting alloys containing more than 0.05% tungsten. The results were obtained with satisfactory precision and accuracy. However, the results obtained for JSS standard high- speed steels containing molybdenum tended to be significantly lower than the certified values. (author)

  20. Biofilm is a Major Virulence Determinant in Bacterial Colonization of Chronic Skin Ulcers Independently from the Multidrug Resistant Phenotype

    Directory of Open Access Journals (Sweden)

    Enea Gino Di Domenico

    2017-05-01

    Full Text Available Bacterial biofilm is a major factor in delayed wound healing and high levels of biofilm production have been repeatedly described in multidrug resistant organisms (MDROs. Nevertheless, a quantitative correlation between biofilm production and the profile of antimicrobial drug resistance in delayed wound healing remains to be determined. Microbial identification, antibiotic susceptibility and biofilm production were assessed in 135 clinical isolates from 87 patients. Gram-negative bacteria were the most represented microorganisms (60.8% with MDROs accounting for 31.8% of the total isolates. Assessment of biofilm production revealed that 80% of the strains were able to form biofilm. A comparable level of biofilm production was found with both MDRO and not-MDRO with no significant differences between groups. All the methicillin-resistant Staphylococcus aureus (MRSA and 80% of Pseudomonas aeruginosa MDR strains were found as moderate/high biofilm producers. Conversely, less than 17% of Klebsiella pneumoniae extended-spectrum beta-lactamase (ESBL, Escherichia coli-ESBL and Acinetobacter baumannii were moderate/high biofilm producers. Notably, those strains classified as non-biofilm producers, were always associated with biofilm producer bacteria in polymicrobial colonization. This study shows that biofilm producers were present in all chronic skin ulcers, suggesting that biofilm represents a key virulence determinant in promoting bacterial persistence and chronicity of ulcerative lesions independently from the MDRO phenotype.

  1. A Simple and Sensitive Plant-Based Western Corn Rootworm Bioassay Method for Resistance Determination and Event Selection.

    Science.gov (United States)

    Wen, Zhimou; Chen, Jeng Shong

    2018-05-26

    We report here a simple and sensitive plant-based western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), bioassay method that allows for examination of multiple parameters for both plants and insects in a single experimental setup within a short duration. For plants, injury to roots can be visually examined, fresh root weight can be measured, and expression of trait protein in plant roots can be analyzed. For insects, in addition to survival, larval growth and development can be evaluated in several aspects including body weight gain, body length, and head capsule width. We demonstrated using the method that eCry3.1Ab-expressing 5307 corn was very effective against western corn rootworm by eliciting high mortality and significantly inhibiting larval growth and development. We also validated that the method allowed determination of resistance in an eCry3.1Ab-resistant western corn rootworm strain. While data presented in this paper demonstrate the usefulness of the method for selection of events of protein traits and for determination of resistance in laboratory populations, we envision that the method can be applied in much broader applications.

  2. Characterization of antibiotic resistance in Salmonella enterica isolates determined from ready-to-eat (RTE) salad vegetables.

    Science.gov (United States)

    Taban, Birce Mercanoglu; Aytac, Sait Aykut; Akkoc, Nefise; Akcelik, Mustafa

    2013-01-01

    In the last decade, ready-to-eat (RTE) salad vegetables are gaining increasing importance in human diet. However, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. During 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in Ankara, and were examined for Salmonella contamination. Salmonella screening was performed by using anti-Salmonella magnetic beads system and polymerase chain reaction (PCR) identification of the suspected colonies. Then, the antibiotic resistance profiles of four Salmonella strains identified (strains RTE-1, RTE-2, RTE-3, and RTE-4) were also investigated, since the mechanism by which Salmonella spp. have accumulated antibiotic resistance genes is of interest. All strains showed resistance against sulfonamides (MIC > 128 mg/L). Further results suggested that associated sulfonamide resistance genes were encoded by the 55.0 kb plasmid of strain RTE-1 that involves no integrons. As a result of using two primers (P1254 and P1283) in randomly amplified polymorphic DNA-PCR (RAPD-PCR) analysis, two common amplicons (364 bp and 1065 bp) were determined. The findings of this study provide support to the adoption of guidelines for the prudent use of antibiotics in order to reduce the number of pathogens present on vegetable and fruit farms. Besides, since it is shown that these bacteria started to gain resistance to antibiotics, it is necessary to further investigate the prevalence of them in foods.

  3. Characterization of antibiotic resistance in Salmonella enterica isolates determined from ready-to-eat (RTE salad vegetables

    Directory of Open Access Journals (Sweden)

    Birce Mercanoglu Taban

    2013-01-01

    Full Text Available In the last decade, ready-to-eat (RTE salad vegetables are gaining increasing importance in human diet. However, since they are consumed fresh, inadequate washing during processing can bring on some foodborne illnesses, like salmonellosis, since these food items have natural contamination from soil and water. During 2009-2010, a total of 81 samples were purchased arbitrarily from local markets in Ankara, and were examined for Salmonella contamination. Salmonella screening was performed by using anti-Salmonella magnetic beads system and polymerase chain reaction (PCR identification of the suspected colonies. Then, the antibiotic resistance profiles of four Salmonella strains identified (strains RTE-1, RTE-2, RTE-3, and RTE-4 were also investigated, since the mechanism by which Salmonella spp. have accumulated antibiotic resistance genes is of interest. All strains showed resistance against sulfonamides (MIC > 128 mg/L. Further results suggested that associated sulfonamide resistance genes were encoded by the 55.0 kb plasmid of strain RTE-1 that involves no integrons. As a result of using two primers (P1254 and P1283 in randomly amplified polymorphic DNA-PCR (RAPD-PCR analysis, two common amplicons (364 bp and 1065 bp were determined. The findings of this study provide support to the adoption of guidelines for the prudent use of antibiotics in order to reduce the number of pathogens present on vegetable and fruit farms. Besides, since it is shown that these bacteria started to gain resistance to antibiotics, it is necessary to further investigate the prevalence of them in foods.

  4. Determination of physiological, taxonomic, and molecular characteristics of a cultivable arsenic-resistant bacterial community.

    Science.gov (United States)

    Cordi, A; Pagnout, C; Devin, S; Poirel, J; Billard, P; Dollard, M A; Bauda, P

    2015-09-01

    A collection of 219 bacterial arsenic-resistant isolates was constituted from neutral arsenic mine drainage sediments. Isolates were grown aerobically or anaerobically during 21 days on solid DR2A medium using agar or gelan gum as gelling agent, with 7 mM As(III) or 20 mM As(V) as selective pressure. Interestingly, the sum of the different incubation conditions used (arsenic form, gelling agent, oxygen pressure) results in an overall increase of the isolate diversity. Isolated strains mainly belonged to Proteobacteria (63%), Actinobacteria (25%), and Bacteroidetes (10%). The most representative genera were Pseudomonas (20%), Acinetobacter (8%), and Serratia (15%) among the Proteobacteria; Rhodococcus (13%) and Microbacterium (5%) among Actinobacteria; and Flavobacterium (13%) among the Bacteroidetes. Isolates were screened for the presence of arsenic-related genes (arsB, ACR3(1), ACR3(2), aioA, arsM, and arrA). In this way, 106 ACR3(1)-, 74 arsB-, 22 aioA-, 14 ACR3(2)-, and one arsM-positive PCR products were obtained and sequenced. Analysis of isolate sensitivity toward metalloids (arsenite, arsenate, and antimonite) revealed correlations between taxonomy, sensitivity, and genotype. Antimonite sensitivity correlated with the presence of ACR3(1) mainly present in Bacteroidetes and Actinobacteria, and arsenite or antimonite resistance correlated with arsB gene presence. The presence of either aioA gene or several different arsenite carrier genes did not ensure a high level of arsenic resistance in the tested conditions.

  5. Milk contamination and resistance to processing conditions determine the fate of Lactococcus lactis bacteriophages in dairies.

    Science.gov (United States)

    Madera, Carmen; Monjardín, Cristina; Suárez, Juan E

    2004-12-01

    Milk contamination by phages, the susceptibility of the phages to pasteurization, and the high levels of resistance to phage infection of starter strains condition the evolution dynamics of phage populations in dairy environments. Approximately 10% (83 of 900) of raw milk samples contained phages of the quasi-species c2 (72%), 936 (24%), and P335 (4%). However, 936 phages were isolated from 20 of 24 (85%) whey samples, while c2 was detected in only one (4%) of these samples. This switch may have been due to the higher susceptibility of c2 to pasteurization (936-like phages were found to be approximately 35 times more resistant than c2 strains to treatment of contaminated milk in a plate heat exchanger at 72 degrees C for 15 s). The restriction patterns of 936-like phages isolated from milk and whey were different, indicating that survival to pasteurization does not result in direct contamination of the dairy environment. The main alternative source of phages (commercial bacterial starters) does not appear to significantly contribute to phage contamination. Twenty-four strains isolated from nine starter formulations were generally resistant to phage infection, and very small progeny were generated upon induction of the lytic cycle of resident prophages. Thus, we postulate that a continuous supply of contaminated milk, followed by pasteurization, creates a factory environment rich in diverse 936 phage strains. This equilibrium would be broken if a particular starter strain turned out to be susceptible to infection by one of these 936-like phages, which, as a consequence, became prevalent.

  6. Porosity determination from 2-D resistivity method in studying the slope failures

    Science.gov (United States)

    Maslinda, Umi; Nordiana, M. M.; Bery, A. A.

    2017-07-01

    Slope failures have become the main focus for infrastructures development on hilly areas in Malaysia especially the development of tourism and residential. Lack of understanding and information of the subsoil conditions and geotechnical issues are the main cause of the slope failures. The failures happened are due to a combination of few factors such as topography, climate, geology and land use. 2-D resistivity method was conducted at the collapsed area in Selangor. The 2-D resistivity was done to study the instability of the area. The collapsed occurred because of the subsurface materials was unstable. Pole-dipole array was used with 5 m minimum electrode spacing for the 2-D resistivity method. The data was processed using Res2Dinv software and the porosity was calculated using Archie's law equation. The results show that the saturated zone (1-100 Ωm), alluvium or highly weathered rock (100-1000 Ωm), boulders (1600-7000 Ωm) and granitic bedrock (>7000 Ωm). Generally, the slope failures or landslides occur during the wet season or after rainfall. It is because of the water infiltrate to the slope and cause the saturation of the slope which can lead to landslides. Then, the porosity of saturated zone is usually high because of the water content. The area of alluvium or highly weathered rock and saturated zone have high porosity (>20%) and the high porosity also dominated at almost all the collapsed area which means that the materials with porosity >20% is potential to be saturated, unstable and might trigger slope failures.

  7. Determination of the resistance types to Spodoptera cosmioides (Walker (Lepidoptera: Noctuidae in soybean genotypes

    Directory of Open Access Journals (Sweden)

    Arlindo Leal Boiça Júnior

    2015-04-01

    Full Text Available The aim of this work was to evaluate the resistance types in soybean genotypes to Spodoptera cosmioides (Walker in laboratory. Soybean genotypes assessed were as follows: ‘IAC 100’ (resistance standard, ‘BR16’ (susceptible standard, ‘Dowling’, PI 227687, PI 274454, ‘IGRA RA 626 RR’, PI 227682, ‘BRSGO 8360’, ‘IGRA RA 516 RR’ and ‘P 98Y11 RR’. Free-choice and no-choice feeding non-preference tests were done using two newly-hatched larvae per genotype or one third-instar larva per genotype in both tests. Larvae attractiveness was evaluated in different times, and at the end of the experiments the leaf area consumed was quantified. In the antibiosis test, newly-hatched larvae were individualized into Petri dishes, where leaflets of the genotypes were offered over the larval stage, and the following biological parameters were assessed: period and viability of larvae, pupae and overall (larvae + pupae, weight of larvae and pupae, sex ratio and adults longevity. Overall, in the feeding preference tests, significant differences were not found in leaf consumption among the genotypes. In the antibiosis assay, genotypes PI 227687, PI 227682 and ‘IAC 100’ caused 100% larval mortality and the lowest weight of larvae, ranging between 37.65 and 85.56 mg. All soybean genotypes evaluated do not exhibit feeding non-preference type resistance to S. cosmioides, and PI 227687, PI 227682 and ‘IAC 100’ highlighted for possessing antibiosis.

  8. Is heart rate variability a feasible method to determine anaerobic threshold in progressive resistance exercise in coronary artery disease?

    Science.gov (United States)

    Sperling, Milena P R; Simões, Rodrigo P; Caruso, Flávia C R; Mendes, Renata G; Arena, Ross; Borghi-Silva, Audrey

    2016-01-01

    Recent studies have shown that the magnitude of the metabolic and autonomic responses during progressive resistance exercise (PRE) is associated with the determination of the anaerobic threshold (AT). AT is an important parameter to determine intensity in dynamic exercise. To investigate the metabolic and cardiac autonomic responses during dynamic resistance exercise in patients with Coronary Artery Disease (CAD). Twenty men (age = 63±7 years) with CAD [Left Ventricular Ejection Fraction (LVEF) = 60±10%] underwent a PRE protocol on a leg press until maximal exertion. The protocol began at 10% of One Repetition Maximum Test (1-RM), with subsequent increases of 10% until maximal exhaustion. Heart Rate Variability (HRV) indices from Poincaré plots (SD1, SD2, SD1/SD2) and time domain (rMSSD and RMSM), and blood lactate were determined at rest and during PRE. Significant alterations in HRV and blood lactate were observed starting at 30% of 1-RM (p<0.05). Bland-Altman plots revealed a consistent agreement between blood lactate threshold (LT) and rMSSD threshold (rMSSDT) and between LT and SD1 threshold (SD1T). Relative values of 1-RM in all LT, rMSSDT and SD1T did not differ (29%±5 vs 28%±5 vs 29%±5 Kg, respectively). HRV during PRE could be a feasible noninvasive method of determining AT in CAD patients to plan intensities during cardiac rehabilitation.

  9. Direct resolution and quantitative analysis of flurbiprofen enantiomers using microcrystalline cellulose triacetate plates: applications to the enantiomeric purity control and optical isomer determination in widely consumed drugs.

    Science.gov (United States)

    Del Bubba, M; Checchini, L; Ciofi, L; Furlanetto, S; Lepri, L

    2014-01-01

    Flurbiprofen enantiomers have very different pharmacological properties, since the (S)-(+) form has a much higher anti-inflammatory activity than the (R)-(-) isomer, the latter being responsible for very undesirable side effects, such as gastrointestinal irritation. Based on the different biological properties of flurbiprofen enantiomers, the development of chiral chromatographic methods for the control of the enantiomeric purity is a very important topic. In this study the separation of flurbiprofen enantiomers was achieved using for the first time noncommercial MCTA layers with polyvinyl alcohol as binder, which gives to these plates a mechanical stability equivalent to that of marketed ones. Baseline resolution (α = 1.31; RS = 2.0) was obtained with ethanol-acetic acid solution (pH 3.0 ± 0.1; 60:40, v/v) as eluent and a migration distance of about 14.5 cm. Under these experimental conditions, the thin-layer chromatography determination of the enantiomeric purity of the pharmacologically active (S)-(+)-flurbiprofen in the presence of 1% of the undesired (R)-(-) form was demonstrated. Moreover, the quantitative analysis of flurbiprofen enantiomers was achieved, obtaining quantification limits and detection limits of 50 and 25 ng of each enantiomer applied to the plate, respectively. The method was succesfully applied to the enantiomer determination in widely consumed drugs, obtaining results consistent with the flurbiprofen content declared in the drug facts. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Recommendations to address the difficulties encountered when determining linezolid resistance from whole genome sequencing data.

    Science.gov (United States)

    Beukers, Alicia G; Hasman, Henrik; Hegstad, Kristin; van Hal, Sebastiaan J

    2018-05-29

    Mutations associated with linezolid resistance within the V domain of 23S rRNA are annotated using an Escherichia coli numbering system. The 23S rRNA gene varies in length, nucleotide sequence and copy number between bacterial species. Consequently, this numbering system is not intuitive and can lead to confusion when locating mutation sites using whole genome sequencing data. Using the mutation G2576T as an example, we demonstrate the difficulties associated with using the E. coli numbering system. © Crown copyright 2018.

  11. Determination of the resistance of fabric printed with triclosan microcapsules to the action of soil micro-flora

    Science.gov (United States)

    Golja, B.; Forte Tavčer, P.

    2017-10-01

    Microcapsules with a pressure-sensitive melamine-formaldehyde wall and triclosan core were printed to 100% cotton fabric with screen printing technique. Previous research showed excellent antibacterial activity (estimated for E. Coli and S. Aureus) of such fabric, so our aim in this research was to determine its resistance to the action of microorganisms present in the soil. The soil burial test was conducted. The breaking strength of the buried samples was measured and also the scanning electron microscope analysis was done. The results showed that none of the samples are resistant to decay. It is evident from SEM micrographs that on all of the buried samples greater morphological changes occur due to the functions of the soil microflora. It can be concluded that the samples printed with triclosan microcapsules are biodegradable which is environmentally preferable.

  12. Determination of Abundance of Tellurite-Resistant Bacteria and the Ability of Remove of them from Qom Province Industrial Wastewater, Qom, Iran

    Directory of Open Access Journals (Sweden)

    Mahboubeh Soleimani Sasani

    2013-02-01

    Full Text Available Background and Objectives: Accumulation of toxic oxyanion of potassium tellurite, which has increased in the environment due to industrial activities, can cause complications in human, such as skin irritation, dermatitis, anorexia, tremor, nausea, vomiting, nervous system stimulation, convulsion, and respiratory arrest. The purpose of this research was to isolate tellurite-resistant bacteria, determine the minimum inhibitory concentration (MIC, and evaluate bioreduction of tellurite in strains.Methods: MIC was measured by agar dilution method in 84 resistant strains isolated from wastewater. QWTm6 strain with tolerance of tellurite concentration of 6684μg/ml was selected as superior strain. Toleration of this level of tellurite has not been reported yet. Results: According to biochemical, phenotypic, and physiological characteristics, QWTm6 was initially classified into Staphylococcus genus. Using the spectrophotometric technique and DDTC reagent (A340nm & sodium diethyldithiocarbamate trihydrate, maximum elimination was seen in 0.4mM concentration of potassium tellurite in 24 hours. The strain showed high ability in the elimination of toxic oxyanion of potassium tellurite under a wide range of factors such as pH=(5-11, temperature (15-50◦C, blender speed (50, 100, 150, and 200rpm, various oxyanion concentrations (0.04-1mM, and different percentages of NaCl (0-20%. This strain was also resistant to penicillin, cefixime, tetracycline, chloramphenicol, streptomycin, neomycin, erythromycin, gentamicin, kanamycin, norfloxacin, and ciprofloxacin.Conclusion: The results of this study showed that QWTm6 could be introduced in the international societies as an acceptable candidate for bioremediation, because of its high ability in removal and reduction of potassium tellurite.

  13. Insulin resistance determined by Homeostasis Model Assessment (HOMA) and associations with metabolic syndrome among Chinese children and teenagers.

    Science.gov (United States)

    Yin, Jinhua; Li, Ming; Xu, Lu; Wang, Ying; Cheng, Hong; Zhao, Xiaoyuan; Mi, Jie

    2013-11-15

    The aim of this study is to assess the association between the degree of insulin resistance and the different components of the metabolic syndrome among Chinese children and adolescents. Moreover, to determine the cut-off values for homeostasis model assessment of insulin resistance (HOMA-IR) at MS risk. 3203 Chinese children aged 6 to 18 years were recruited. Anthropometric and biochemical parameters were measured. Metabolic syndrome (MS) was identified by a modified Adult Treatment Panel III (ATP III) definition. HOMA-IR index was calculated and the normal reference ranges were defined from the healthy participants. Receiver operating characteristic (ROC) analysis was used to find the optimal cutoff of HOMA-IR for diagnosis of MS. With the increase of insulin resistance (quintile of HOMA-IR value), the ORs of suffering MS or its related components were significantly increased. Participants in the highest quintile of HOMA-IR were about 60 times more likely to be classified with metabolic syndrome than those in the lowest quintile group. Similarly, the mean values of insulin and HOMA-IR increased with the number of MS components. The present HOMA-IR cutoff point corresponding to the 95th percentile of our healthy reference children was 3.0 for whole participants, 2.6 for children in prepubertal stage and 3.2 in pubertal period, respectively. The optimal point for diagnosis of MS was 2.3 in total participants, 1.7 in prepubertal children and 2.6 in pubertal adolescents, respectively, by ROC curve, which yielded high sensitivity and moderate specificity for a screening test. According to HOMA-IR > 3.0, the prevalence of insulin resistance in obese or MS children were 44.3% and 61.6% respectively. Our data indicates insulin resistance is common among Chinese obese children and adolescents, and is strongly related to MS risk, therefore requiring consideration early in life. As a reliable measure of insulin resistance and assessment of MS risk, the optimal HOMA-IR cut

  14. Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

    Science.gov (United States)

    Carlson, D.

    2010-01-01

    Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  15. The Escherichia coli BtuE protein functions as a resistance determinant against reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Felipe A Arenas

    2011-01-01

    Full Text Available This work shows that the recently described Escherichia coli BtuE peroxidase protects the bacterium against oxidative stress that is generated by tellurite and by other reactive oxygen species elicitors (ROS. Cells lacking btuE (ΔbtuE displayed higher sensitivity to K(2TeO(3 and other oxidative stress-generating agents than did the isogenic, parental, wild-type strain. They also exhibited increased levels of cytoplasmic reactive oxygen species, oxidized proteins, thiobarbituric acid reactive substances, and lipoperoxides. E. coli ΔbtuE that was exposed to tellurite or H(2O(2 did not show growth changes relative to wild type cells either in aerobic or anaerobic conditions. Nevertheless, the elimination of btuE from cells deficient in catalases/peroxidases (Hpx(- resulted in impaired growth and resistance to these toxicants only in aerobic conditions, suggesting that BtuE is involved in the defense against oxidative damage. Genetic complementation of E. coli ΔbtuE restored toxicant resistance to levels exhibited by the wild type strain. As expected, btuE overexpression resulted in decreased amounts of oxidative damage products as well as in lower transcriptional levels of the oxidative stress-induced genes ibpA, soxS and katG.

  16. Determination of Soft Lithology Causes The Land Subsidence in Coastal Semarang City by Resistivity Methods

    Science.gov (United States)

    Widada, Sugeng; Saputra, Sidhi; Hariadi

    2018-02-01

    Semarang City is located in the northern coastal plain of Java which is geologically composed of alluvial deposits. The process of the sediment diagenesis has caused a land subsidence. On the other hand, the development of the industrial, service, education and housing sectors has increased the number of building significantly. The number of building makes the pressure of land surface increased, and finally, this also increased the rate of land subsidence. The drilling data indicates that not all layers of lithology are soft layers supporting the land subsidence. However, vertical distribution of the soft layer is still unclear. This study used Resistivity method to map out the soft zone layers of lithology. Schlumberger electrode configuration with sounding system method was selected to find a good vertical resolution and maximum depth. The results showed that the lithology layer with resistivity less than 3 ohm is a layer of clay and sandy clay that has the low bearing capacity so easily compressed by pressure load. A high land subsidence is happening in the thick soft layer. The thickness of that layer is smaller toward the direction of avoiding the beach. The improvement of the bearing capacity of this layer is expected to be a solution to the problem of land subsidence.

  17. Determination of work function of graphene under a metal electrode and its role in contact resistance.

    Science.gov (United States)

    Song, Seung Min; Park, Jong Kyung; Sul, One Jae; Cho, Byung Jin

    2012-08-08

    Although the work function of graphene under a given metal electrode is critical information for the realization of high-performance graphene-based electronic devices, relatively little relevant research has been carried out to date. In this work, the work function values of graphene under various metals are accurately measured for the first time through a detailed analysis of the capacitance-voltage (C-V) characteristics of a metal-graphene-oxide-semiconductor (MGOS) capacitor structure. In contrast to the high work function of exposed graphene of 4.89-5.16 eV, the work function of graphene under a metal electrode varies depending on the metal species. With a Cr/Au or Ni contact, the work function of graphene is pinned to that of the contacted metal, whereas with a Pd or Au contact the work function assumes a value of ∼4.62 eV regardless of the work function of the contact metal. A study of the gate voltage dependence on the contact resistance shows that the latter case provides lower contact resistance.

  18. Estimation of hydraulic conductivity on clay content in soil determined from resistivity data

    Energy Technology Data Exchange (ETDEWEB)

    Shevnin, Vladimir; Delgado-Rodriguez, Omar; Mousatov, Aleksandr [Mexican Petroleum Institute, Mexico, D.F. (Mexico); Ryjov, Albert [Moscow State Geological Prospecting Academy, Geophysical Faculty, Moscow (Russian Federation)

    2006-07-15

    The influence of clay content in sandy and clayey soils on hydraulic conductivity (filtration coefficient) is considered. A review of published experimental data on the relationship of hydraulic conductivity with soil lithology and grain size, as dependent on clay content is presented. Theoretical calculations include clay content. Experimental and calculated data agree, and several approximation formulas for filtration coefficient vs clay content are presented. Clay content in soil is estimated from electric resistivity data obtained from 2D VES interpretation. A two-step method is proposed, the first step including clay content calculating from soil resistivity and groundwater salinity, and the second step including filtration coefficient estimating from clay content. Two applications are presented. [Spanish] El contenido de arcilla en suelos areno-arcillosos influye sobre la permeabilidad hidraulica (coeficiente de filtracion). Se presenta una revision de datos experimentales publicados que relacionan el coeficiente de filtracion con el tipo litologico del suelo y el tamano de las particulas. A partir de calculos teoricos, se modifican las conocidas formulas que relacionan el coeficiente de filtracion con el contenido de arcilla. Se estima el contenido de arcilla a partir de los datos interpretados por el metodo SEV, y se propone un procedimiento para la estimacion del coeficiente de filtracion: (a) calculo del contenido de arcilla a partir de la resistividad del suelo y de la salinidad del agua subterranea, (b) estimacion del coeficiente de filtracion a partir del contenido de arcilla. Se presentan algunos ejemplos de la aplicacion de esta metodologia.

  19. NIRS determination of non-structural carbohydrates, water soluble carbohydrates and other nutritive quality traits in whole plant maize with wide range variability

    Directory of Open Access Journals (Sweden)

    L. Campo

    2013-05-01

    Full Text Available The aim of this work was to study the potential of near-infrared reflectance spectroscopy (NIRS to predict non-structural carbohydrates (NSC, water soluble carbohydrates (WSC, in vitro organic dry matter digestibility (IVOMD, organic matter (OM, crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF and starch in samples of whole plant maize with a wide range of variability. The samples were analyzed in reflectance mode by a spectrophotometer FOSS NIRSystems 6500. Four hundred and fifty samples of wide spectrum from different origin were selected out of 3000 scanned for the calibration set, whereas 87 independent random samples were used in the external validation. The goodness of the calibration models was evaluated using the following statistics: coefficient of determination (R2, standard error of cross-validation (SECV, standard error of prediction for external validation (SEP and the RPDCV and RPDP indexes [ratios of standard deviation (SD of reference analysis data to SECV and SEP, respectively]. The smaller the SECV and SEP and the greater the RPDCV and RPDP, the predictions are better. Trait measurement units were g/100g of dry matter (DM, except for IVOMD (g/100g OM. The SECV and RPDCV statistics of the calibration set were 1.34 and 3.2 for WSC, 2.57 and 3 for NSC and 2.3 and 2.2 for IVOMD, respectively. The SEP and RPDP statistics for external validation were 0.74 and 4.7 for WSC, 2.14 and 2.5 for NSC and 1.68 and 1.6 for IVOMD respectively. It can be concluded that the NIRS technique can be used to predict WSC and NSC with good accuracy, whereas prediction of IVOMD showed a lesser accuracy. NIRS predictions of OM, CP, NDF, ADF and starch also showed good accuracy.

  20. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2001-01-01

    . Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among...

  1. Applicability of the lattice Boltzmann method to determine the ohmic resistance in equivalent resistor connections

    Science.gov (United States)

    Espinoza-Andaluz, Mayken; Barzola, Julio; Guarochico-Moreira, Víctor H.; Andersson, Martin

    2017-12-01

    Knowing the ohmic resistance in the materials allow to know in advance its electrical behavior when a potential difference is applied, and therefore the prediction of the electrical performance can be achieved in a most certain manner. Although the Lattice Boltzmann method (LBM) has been applied to solve several physical phenomena in complex geometries, it has only been used to describe the fluid phase, but applicability studies of LBM on the solid-electric-conducting material have not been carried out yet. The purpose of this paper is to demonstrate the accuracy of calculating the equivalent resistor connections using LBM. Several series and parallel resistor connections are effected. All the computations are carried out with 3D models, and the domain materials are designed by the authors.

  2. Rapid determination of anti-tuberculosis drug resistance from whole-genome sequences

    KAUST Repository

    Coll, Francesc

    2015-05-27

    Mycobacterium tuberculosis drug resistance (DR) challenges effective tuberculosis disease control. Current molecular tests examine limited numbers of mutations, and although whole genome sequencing approaches could fully characterise DR, data complexity has restricted their clinical application. A library (1,325 mutations) predictive of DR for 15 anti-tuberculosis drugs was compiled and validated for 11 of them using genomic-phenotypic data from 792 strains. A rapid online ‘TB-Profiler’ tool was developed to report DR and strain-type profiles directly from raw sequences. Using our DR mutation library, in silico diagnostic accuracy was superior to some commercial diagnostics and alternative databases. The library will facilitate sequence-based drug-susceptibility testing.

  3. Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome

    Science.gov (United States)

    Paniagua, Juan Antonio

    2016-01-01

    Obesity is an excessive accumulation of body fat that may be harmful to health. Today, obesity is a major public health problem, affecting in greater or lesser proportion all demographic groups. Obesity is estimated by body mass index (BMI) in a clinical setting, but BMI reports neither body composition nor the location of excess body fat. Deaths from cardiovascular diseases, cancer and diabetes accounted for approximately 65% of all deaths, and adiposity and mainly abdominal adiposity are associated with all these disorders. Adipose tissue could expand to inflexibility levels. Then, adiposity is associated with a state of low-grade chronic inflammation, with increased tumor necrosis factor-α and interleukin-6 release, which interfere with adipose cell differentiation, and the action pattern of adiponectin and leptin until the adipose tissue begins to be dysfunctional. In this state the subject presents insulin resistance and hyperinsulinemia, probably the first step of a dysfunctional metabolic system. Subsequent to central obesity, insulin resistance, hyperglycemia, hypertriglyceridemia, hypoalphalipoproteinemia, hypertension and fatty liver are grouped in the so-called metabolic syndrome (MetS). In subjects with MetS an energy balance is critical to maintain a healthy body weight, mainly limiting the intake of high energy density foods (fat). However, high-carbohydrate rich (CHO) diets increase postprandial peaks of insulin and glucose. Triglyceride-rich lipoproteins are also increased, which interferes with reverse cholesterol transport lowering high-density lipoprotein cholesterol. In addition, CHO-rich diets could move fat from peripheral to central deposits and reduce adiponectin activity in peripheral adipose tissue. All these are improved with monounsaturated fatty acid-rich diets. Lastly, increased portions of ω-3 and ω-6 fatty acids also decrease triglyceride levels, and complement the healthy diet that is recommended in patients with MetS. PMID

  4. Nutrition, insulin resistance and dysfunctional adipose tissue determine the different components of metabolic syndrome

    Institute of Scientific and Technical Information of China (English)

    Juan; Antonio; Paniagua[1,2

    2016-01-01

    Obesity is an excessive accumulation of body fat that may be harmful to health. Today, obesity is a major public health problem, affecting in greater or lesser proportion all demographic groups. Obesity is estimated by body mass index (BMI) in a clinical setting, but BMI reports neither body composition nor the location of excess body fat.Deaths from cardiovascular diseases, cancer and diabetes accounted for approximately 65% of all deaths, and adiposity and mainly abdominal adiposity are associated with all these disorders. Adipose tissue could expand to inflexibility levels. Then, adiposity is associated with a state of low-grade chronic inflammation, with increased tumor necrosis factor-α and interleukin-6 release, which interfere with adipose cell differentiation, and the action pattern of adiponectin and leptin until the adipose tissue begins to be dysfunctional. In this state the subject presents insulin resistance and hyperinsulinemia, probably the first step of a dysfunctional metabolic system. Subsequent to central obesity, insulin resistance, hyperglycemia,hypertriglyceridemia, hypoalphalipoproteinemia, hypertension and fatty liver are grouped in the so-called metabolic syndrome (MetS). In subjects with MetS an energy balance is critical to maintain a healthy body weight, mainly limiting the intake of high energy density foods (fat). However, high-carbohydrate rich (CHO) diets increase postprandial peaks of insulin and glucose.Triglyceride-rich lipoproteins are also increased, which interferes with reverse cholesterol transport lowering highdensity lipoprotein cholesterol. In addition, CHO-rich diets could move fat from peripheral to central deposits and reduce adiponectin activity in peripheral adipose tissue. All these are improved with monounsaturated fatty acid-rich diets. Lastly, increased portions of ω-3 and ω-6 fatty acids also decrease triglyceride levels, and complement the healthy diet that is recommended in patients with MetS.

  5. Determination of antibiotic resistance profile in Klebsiella pneumonia strains isolated from urinary tract infections of patients hospitalized in Peyambaran hospital (Tehran-Iran

    Directory of Open Access Journals (Sweden)

    Marzieh Tavakol

    2017-04-01

    Full Text Available Background: Urinary tract infection (UTI is the second prevalent infection in human mostly caused by Escherichia coli and Klebsiella pneumonia. The aim of this study was to determine the antibiotic resistance profile and detect the prevalence of antibiotic resistance encoding genes in K .pneumoniae isolated from UTI. Materials and Methods: Fifty K. pneumonia strains isolated from 122 UTI samples of hospitalized patients in Payambaran Hospital (Tehran, Iran which were subjected to this study (2014 were confirmed by standard biochemical tests. Isolates were tested for susceptibility to 10 antimicrobial drugs by using disk diffusion method. Antibiotic resistance encoding genes frequently include the aadA1, aac(3-IV, sul1, blaSHV, Cat1, cmlA, tetA, tetB, dfrA1, CITM, qnr in isolates were determined by PCR. Results: The highest antibiotic resistance in K. pneumoniae isolates were for Tetracycline and the lowest resistance (2% for Gentamicin and Imipenem. To determine the frequency of antibiotic resistant genes, 64% and 4% of isolates had tetA and Gentamicin-(aac(3-IV resistant genes, respectively. Conclusion: Frequency of antibiotic resistance encoding genes may have important and basic role in the occurrence and transfer of antibiotic resistance which can be due to the indiscriminate use of antibiotics.

  6. Maternal malnutrition and offspring sex determine juvenile obesity and metabolic disorders in a swine model of leptin resistance.

    Directory of Open Access Journals (Sweden)

    Alicia Barbero

    Full Text Available The present study aimed to determine, in a swine model of leptin resistance, the effects of type and timing of maternal malnutrition on growth patterns, adiposity and metabolic features of the progeny when exposed to an obesogenic diet during their juvenile development and possible concomitant effects of the offspring sex. Thus, four groups were considered. A CONTROL group involved pigs born from sows fed with a diet fulfilling their daily maintenance requirements for pregnancy. The treated groups involved the progeny of females fed with the same diet but fulfilling either 160% or 50% of pregnancy requirements during the entire gestation (OVERFED and UNDERFED, respectively or 100% of requirements until Day 35 of pregnancy and 50% of such amount from Day 36 onwards (LATE-UNDERFED. OVERFED and UNDERFED offspring were more prone to higher corpulence and fat deposition from early postnatal stages, during breast-feeding; adiposity increased significantly when exposed to obesogenic diets, especially in females. The effects of sex were even more remarkable in LATE-UNDERFED offspring, which had similar corpulence to CONTROL piglets; however, females showed a clear predisposition to obesity. Furthermore, the three groups of pigs with maternal malnutrition showed evidences of metabolic syndrome and, in the case of individuals born from OVERFED sows, even of insulin resistance and the prodrome of type-2 diabetes. These findings support the main role of early nutritional programming in the current rise of obesity and associated diseases in ethnics with leptin resistance.

  7. The evaluation of the classical Kirby-Bauer antibiogram method for the determination of antibiotic resistant microorganisms in tap water

    Directory of Open Access Journals (Sweden)

    Siedlecka Agata

    2017-01-01

    Full Text Available Water supply systems are the main source of potable water for many inhabitants. The European Union and Polish laws demand high quality of tap water, but the aspect of antibiotic resistant bacteria (ARB is not mentioned. The special emphasis is placed on the presence of pathogenic microorganisms in water, determining by the presence of chosen indicators. Although these regulations provide quite good quality of drinking water, the neglect of resistance vectors could lead to a serious threat to human health. In this study the randomly chosen sample of water from the Wroclaw water supply system was tested in order to evaluate the usefulness of Kirby-Bauer antibiogram method for the assessment of the presence of ARB. The susceptibility testing with 6 chosen antibiotics was performed on bacterial strains isolated from the sample. The diameters of growth inhibition zones were measured and the preliminary identification of strains was carried out, including Gram staining and bacterial cellular morphologies assessments. Although full recognition of the drug resistance phenomenon demands the identification of bacterial species for the comparison with susceptibility testing guidelines, this preliminary research could answer the question, whether the Kirby-Bauer method is sufficient for investigations of ARB dwelling in Wroclaw tap water or the other solution should be applied.

  8. Laboratory determination of chemotherapeutic drug resistance in tumor cells from patients with leukemia, using a fluorometric microculture cytotoxicity assay (FMCA).

    Science.gov (United States)

    Larsson, R; Kristensen, J; Sandberg, C; Nygren, P

    1992-01-21

    An automated fluorometric microculture cytotoxicity assay (FMCA) based on the measurement of fluorescence generated from cellular hydrolysis of fluorescein diacetate (FDA) to fluorescein was employed for chemotherapeutic-drug-sensitivity testing of tumor-cell suspensions from patients with leukemia. Fluorescence was linearly related to cell number, and reproducible measurements of drug sensitivity could be performed using fresh or cryopreserved leukemia cells. A marked heterogeneity with respect to chemotherapeutic drug sensitivity was observed for a panel of cytotoxic drugs tested in 43 samples from 35 patients with treated or untreated acute and chronic leukemia. For samples obtained from patients with chronic lymphocytic and acute myelocytic leukemia, sensitivity profiles for standard drugs corresponded to known clinical activity and the assay detected primary and acquired drug resistance. Individual in vitro/in vivo correlations indicated high specificity with respect to the identification of drug resistance. The results suggest that the FMCA may be a simple and rapid method for in vivo-representative determinations of chemotherapeutic drug resistance in tumor cells obtained from patients with leukemia.

  9. Determination antimicrobial resistance profile of Acinetobacter strains isolated from hospitalized patients in Different Part of Taleghani Hospital (Ahvaz, Iran

    Directory of Open Access Journals (Sweden)

    Khadijah Ahmadi

    2014-10-01

    Full Text Available Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial infections such as meningitis, endocarditis, skin and soft tissue infections, urinary tract infection, conjunctivitis, burn wound infection and bacteremia. This organism has been shown resistance to different antimicrobial agents. The aim of this study was to determination antibiotic resistance profile of Acinetobacter strains isolated from hospitalized patients in Taleghani hospital (Ahvaz, Iran. Materials and Methods: This cross-sectional study was conducted on 43 Acinetobacter strains isolated from hospitalized patients. Clinical specimens were cultured on microbiological media. Subsequently, drug susceptibility test was performed using the disc diffusion method according to CLSI recommendations. Results: Acinetobacter strains were isolated from different specimens consisting biopsy 24 (55.8%, wound 13 (30/2% and blood 6 (14%. In antimicrobial susceptibility testing, colistin exhibited the greatest activity (60.5% against isolated strains. 33 (76/7% isolates demonstrated resistance to imipenem. Conclusion: In outbreak situations, surveillance cultures of patients involved in the outbreak or who are deemed at risk for colonization/infection with the outbreak organism are often parts of the planned intervention.

  10. Crystal Structure of the Substrate-Binding Domain from Listeria monocytogenes Bile-Resistance Determinant BilE

    Directory of Open Access Journals (Sweden)

    Stephanie J. Ruiz

    2016-12-01

    Full Text Available BilE has been reported as a bile resistance determinant that plays an important role in colonization of the gastrointestinal tract by Listeria monocytogenes, the causative agent of listeriosis. The mechanism(s by which BilE mediates bile resistance are unknown. BilE shares significant sequence similarity with ATP-binding cassette (ABC importers that contribute to virulence and stress responses by importing quaternary ammonium compounds that act as compatible solutes. Assays using related compounds have failed to demonstrate transport mediated by BilE. The putative substrate-binding domain (SBD of BilE was expressed in isolation and the crystal structure solved at 1.5 Å. Although the overall fold is characteristic of SBDs, the binding site varies considerably relative to the well-characterized homologs ProX from Archaeoglobus fulgidus and OpuBC and OpuCC from Bacillus subtilis. This suggests that BilE may bind an as-yet unknown ligand. Elucidation of the natural substrate of BilE could reveal a novel bile resistance mechanism.

  11. Salting-out-enhanced ionic liquid microextraction with a dual-role solvent for simultaneous determination of trace pollutants with a wide polarity range in aqueous samples.

    Science.gov (United States)

    Gao, Man; Qu, Jingang; Chen, Kai; Jin, Lide; Dahlgren, Randy Alan; Wang, Huili; Tan, Chengxia; Wang, Xuedong

    2017-11-01

    In real aquatic environments, many occupational pollutants with a wide range of polarities coexist at nanogram to milligram per liter levels. Most reported microextraction methods focus on extracting compounds with similar properties (e.g., polarity or specific functional groups). Herein, we developed a salting-out-enhanced ionic liquid microextraction based on a dual-role solvent (SILM-DS) for simultaneous detection of tetracycline, doxycycline, bisphenol A, triclosan, and methyltriclosan, with log K ow ranging from -1.32 to 5.40 in complex milk and environmental water matrices. The disperser in the ionic-liquid-based dispersive liquid-liquid microextraction was converted to the extraction solvent in the subsequent salting-out-assisted microextraction procedures, and thus a single solvent performed a dual role as both extractant and disperser in the SILM-DS process. Acetonitrile was selected as the dual-role solvent because of its strong affinity for both ionic liquids and water, as well as the extractant in the salting-out step. Optimized experimental conditions were 115 μL [C 8 MIM][PF 6 ] as extractor, 1200 μL acetonitrile as dual-role solvent, pH 2.0, 5.0 min ultrasound extraction time, 3.0 g Na 2 SO 4 , and 3.0 min vortex extraction time. Under optimized conditions, the recoveries of the five pollutants ranged from 74.5 to 106.9%, and their LODs were 0.12-0.75 μg kg -1 in milk samples and 0.11-0.79 μg L -1 in environmental waters. Experimental precision based on relative standard deviation was 1.4-6.4% for intraday and 2.3-6.5% for interday analyses. Compared with previous methods, the prominent advantages of the newly developed method are simultaneous determination of pollutants with a wide range of polarities and a substantially reduced workload for ordinary environmental monitoring and food tests. Therefore, the new method has great application potential for simultaneous determination of trace pollutants with strongly contrasting polarities in several

  12. Characterisation and determination of virus resistance among cowpea [Vigna unguiculata (L.) Walp.] Genotypes

    International Nuclear Information System (INIS)

    Tettey, Carlos Kweku

    2017-07-01

    Several households in Ghana feed on cowpea [Vigna unguiculata (L.) Walp.] which serves as good source of protein. However, cowpea viral diseases and the lack of adaptable cultivars have become a limiting factor in cowpea production. This work therefore sought to explore morphogenetic diversity and viral resistance traits in cowpea germplasm to improve productivity. Thirty-eight exotic and local cowpea genotypes were cultivated at the Teaching and Research Field of the School of Agriculture, the University of Cape Coast. Two plants were maintained per stand at planting distance of 50 cm x 30 cm with three replications in a randomized complete block layout during the major (June – September) and minor seasons (November – February). The cowpea genotypes were characterised using both morphological and molecular methods to assess diversity in the coastal savanna agro-ecological zone of Ghana. They were also screened for resistance to cowpea viruses using visual scale on-field and DAS-ELISA protocol. The cowpeas showed significant (P < 0.05) variations in plant height, canopy diameter, number of branches, area of leaf, days to 50% flowering, days to pod maturity, pod length, number of seeds per pod and hundred seed weight. There were significant and positive correlations between pod weight and seed yield (r = 0.985, P < 0.05), plant height and canopy diameter (r = 0.576, P < 0.05), canopy diameter and number of branches (r = 0.576) as well as pod length and the number of seeds per pod (r = 0.530, P < 0.05). Hundred seed weight ranged from 10.03 g to 22.7 g. On the whole, 23 quantitative and qualitative parameters differentiated the cowpea genotypes into two main clusters with sub-clusters. Genomic analysis involving nine polymorphic SSR primers showed a mean genetic diversity of 0.7, polymorphic information content of 0.67 and allele frequency of 0.4 among the cowpea genotypes, which were differentiated into two main clusters with sub-clusters. Incidence and severity

  13. Novel molecular determinants of viral susceptibility and resistance in the lipidome of Emiliania huxleyi.

    Science.gov (United States)

    Fulton, James M; Fredricks, Helen F; Bidle, Kay D; Vardi, Assaf; Kendrick, B Jacob; DiTullio, Giacomo R; Van Mooy, Benjamin A S

    2014-04-01

    Viruses play a key role in controlling the population dynamics of algae, including Emiliania huxleyi, a globally distributed haptophyte with calcite coccoliths that comprise ca. 50% of the sinking carbonate flux from the surface ocean. Emiliania huxleyi viruses (EhVs) routinely infect and terminate E. huxleyi blooms. EhVs are surrounded by a lipid envelope, which we found to be comprised largely of glycosphingolipids (GSLs) with lesser amounts of polar glycerolipids. Infection appears to involve membrane fusion between the virus and host, and we hypothesized that specific polar lipids may facilitate virus attachment. We identified three novel intact polar lipids in E. huxleyi strain CCMP 374 and EhV86, including a GSL with a monosaccharide sialic acid headgroup (sGSL); for all 11 E. huxleyi strains we tested, there was a direct relationship between sGSL content and sensitivity to infection by EhV1, EhV86 and EhV163. In mesocosms, the E. huxleyi population with greatest initial sGSL content had the highest rate of virus-induced mortality. We propose potential physiological roles for sGSL that would be beneficial for growth but leave cells susceptible to infection, thus furthering the discussion of Red Queen-based co-evolution and the cost(s) of sensitivity and resistance in the dynamic E. huxleyi-EhV system. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Lab on a chip sensor for rapid detection and antibiotic resistance determination of Staphylococcus aureus.

    Science.gov (United States)

    Abeyrathne, Chathurika D; Huynh, Duc H; Mcintire, Thomas W; Nguyen, Thanh C; Nasr, Babak; Zantomio, Daniela; Chana, Gursharan; Abbott, Iain; Choong, Peter; Catton, Mike; Skafidas, Efstratios

    2016-03-21

    The Gram-positive bacterium, Staphylococcus aureus (S. aureus), is a major pathogen responsible for a variety of infectious diseases ranging from cellulitis to more serious conditions such as septic arthritis and septicaemia. Timely treatment with appropriate antibiotic therapy is essential to ensure clinical defervescence and to prevent further complications such as infective endocarditis or organ impairment due to septic shock. To date, initial antibiotic choice is empirical, using a "best guess" of likely organism and sensitivity- an approach adopted due to the lack of rapid identification methods for bacteria. Current culture based methods take up to 5 days to identify the causative bacterial pathogen and its antibiotic sensitivity. This paper provides proof of concept for a biosensor, based on interdigitated electrodes, to detect the presence of S. aureus and ascertain its sensitivity to flucloxacillin rapidly (within 2 hours) in a cost effective manner. The proposed method is label-free and uses non-faradic measurements. This is the first study to successfully employ interdigitated electrodes for the rapid detection of antibiotic resistance. The method described has important potential outcomes of faster definitive antibiotic treatment and more rapid clinical response to treatment.

  15. Genetic determinants of heel bone properties: genome-wide association meta-analysis and replication in the GEFOS/GENOMOS consortium

    Science.gov (United States)

    Moayyeri, Alireza; Hsu, Yi-Hsiang; Karasik, David; Estrada, Karol; Xiao, Su-Mei; Nielson, Carrie; Srikanth, Priya; Giroux, Sylvie; Wilson, Scott G.; Zheng, Hou-Feng; Smith, Albert V.; Pye, Stephen R.; Leo, Paul J.; Teumer, Alexander; Hwang, Joo-Yeon; Ohlsson, Claes; McGuigan, Fiona; Minster, Ryan L.; Hayward, Caroline; Olmos, José M.; Lyytikäinen, Leo-Pekka; Lewis, Joshua R.; Swart, Karin M.A.; Masi, Laura; Oldmeadow, Chris; Holliday, Elizabeth G.; Cheng, Sulin; van Schoor, Natasja M.; Harvey, Nicholas C.; Kruk, Marcin; del Greco M, Fabiola; Igl, Wilmar; Trummer, Olivia; Grigoriou, Efi; Luben, Robert; Liu, Ching-Ti; Zhou, Yanhua; Oei, Ling; Medina-Gomez, Carolina; Zmuda, Joseph; Tranah, Greg; Brown, Suzanne J.; Williams, Frances M.; Soranzo, Nicole; Jakobsdottir, Johanna; Siggeirsdottir, Kristin; Holliday, Kate L.; Hannemann, Anke; Go, Min Jin; Garcia, Melissa; Polasek, Ozren; Laaksonen, Marika; Zhu, Kun; Enneman, Anke W.; McEvoy, Mark; Peel, Roseanne; Sham, Pak Chung; Jaworski, Maciej; Johansson, Åsa; Hicks, Andrew A.; Pludowski, Pawel; Scott, Rodney; Dhonukshe-Rutten, Rosalie A.M.; van der Velde, Nathalie; Kähönen, Mika; Viikari, Jorma S.; Sievänen, Harri; Raitakari, Olli T.; González-Macías, Jesús; Hernández, Jose L.; Mellström, Dan; Ljunggren, Östen; Cho, Yoon Shin; Völker, Uwe; Nauck, Matthias; Homuth, Georg; Völzke, Henry; Haring, Robin; Brown, Matthew A.; McCloskey, Eugene; Nicholson, Geoffrey C.; Eastell, Richard; Eisman, John A.; Jones, Graeme; Reid, Ian R.; Dennison, Elaine M.; Wark, John; Boonen, Steven; Vanderschueren, Dirk; Wu, Frederick C.W.; Aspelund, Thor; Richards, J. Brent; Bauer, Doug; Hofman, Albert; Khaw, Kay-Tee; Dedoussis, George; Obermayer-Pietsch, Barbara; Gyllensten, Ulf; Pramstaller, Peter P.; Lorenc, Roman S.; Cooper, Cyrus; Kung, Annie Wai Chee; Lips, Paul; Alen, Markku; Attia, John; Brandi, Maria Luisa; de Groot, Lisette C.P.G.M.; Lehtimäki, Terho; Riancho, José A.; Campbell, Harry; Liu, Yongmei; Harris, Tamara B.; Akesson, Kristina; Karlsson, Magnus; Lee, Jong-Young; Wallaschofski, Henri; Duncan, Emma L.; O'Neill, Terence W.; Gudnason, Vilmundur; Spector, Timothy D.; Rousseau, François; Orwoll, Eric; Cummings, Steven R.; Wareham, Nick J.; Rivadeneira, Fernando; Uitterlinden, Andre G.; Prince, Richard L.; Kiel, Douglas P.; Reeve, Jonathan; Kaptoge, Stephen K.

    2014-01-01

    Quantitative ultrasound of the heel captures heel bone properties that independently predict fracture risk and, with bone mineral density (BMD) assessed by X-ray (DXA), may be convenient alternatives for evaluating osteoporosis and fracture risk. We performed a meta-analysis of genome-wide association (GWA) studies to assess the genetic determinants of heel broadband ultrasound attenuation (BUA; n = 14 260), velocity of sound (VOS; n = 15 514) and BMD (n = 4566) in 13 discovery cohorts. Independent replication involved seven cohorts with GWA data (in silico n = 11 452) and new genotyping in 15 cohorts (de novo n = 24 902). In combined random effects, meta-analysis of the discovery and replication cohorts, nine single nucleotide polymorphisms (SNPs) had genome-wide significant (P < 5 × 10−8) associations with heel bone properties. Alongside SNPs within or near previously identified osteoporosis susceptibility genes including ESR1 (6q25.1: rs4869739, rs3020331, rs2982552), SPTBN1 (2p16.2: rs11898505), RSPO3 (6q22.33: rs7741021), WNT16 (7q31.31: rs2908007), DKK1 (10q21.1: rs7902708) and GPATCH1 (19q13.11: rs10416265), we identified a new locus on chromosome 11q14.2 (rs597319 close to TMEM135, a gene recently linked to osteoblastogenesis and longevity) significantly associated with both BUA and VOS (P < 8.23 × 10−14). In meta-analyses involving 25 cohorts with up to 14 985 fracture cases, six of 10 SNPs associated with heel bone properties at P < 5 × 10−6 also had the expected direction of association with any fracture (P < 0.05), including three SNPs with P < 0.005: 6q22.33 (rs7741021), 7q31.31 (rs2908007) and 10q21.1 (rs7902708). In conclusion, this GWA study reveals the effect of several genes common to central DXA-derived BMD and heel ultrasound/DXA measures and points to a new genetic locus with potential implications for better understanding of osteoporosis pathophysiology. PMID:24430505

  16. Tungsten determination in heat resistant nickel-base-alloys by the method of atomic absorption

    International Nuclear Information System (INIS)

    Gregorczyk, S.; Wycislik, A.

    1980-01-01

    A method of atomic absorption was developed. It allows for the tungsten to be determined in heatresistant nickel-base-alloys within the range 0.01 to 7%. It consists in precipitating tungsten acid in the presence of alkaloids with its following decomposition by hydrofluoric acid in the teflon bomb. (author)

  17. Determination of formation heterogeneity at a range of scales using novel multi-electrode resistivity scanning techniques

    International Nuclear Information System (INIS)

    Williams, G.M.; Jackson, P.D.; Ward, R.S.; Sen, M.A.; Meldrum, P.; Lovell, M.

    1991-01-01

    The traditional method of measuring ground resistivity involves passing a current through two outer electrodes, measuring the potential developed across two electrodes in between, and applying Ohm's Law. In the RESCAN system developed by the British Geological Survey, each electrode can be electronically selected and controlled by software to either pass current or measure potential. Thousands of electrodes can be attached to the system either in 2-D surface arrays or along special plastic covered probes driven vertically into the ground or emplaced in boreholes. Under computer control, the resistivity distribution within the emplaced array can be determined automatically with unprecedented detail and speed, and may be displayed as an image. So far, the RESCAN system has been applied at the meso-scale in monitoring the radial migration of an electrolyte introduced into a recharge well in an unconsolidated aquifer; and CORSCAN at the micro-scale on drill cores to evaluate spatial variability in physical properties. The RESCAN technique has considerable potential for determining formation heterogeneity at different scales and provides a basis for developing stochastic models of groundwater and solute flow in heterogeneous systems. 13 figs.; 1 tab.; 12 refs

  18. A standardized method to determine the concentration of extracellular vesicles using tunable resistive pulse sensing

    Directory of Open Access Journals (Sweden)

    Robert Vogel

    2016-09-01

    Full Text Available Background: Understanding the pathogenic role of extracellular vesicles (EVs in disease and their potential diagnostic and therapeutic utility is extremely reliant on in-depth quantification, measurement and identification of EV sub-populations. Quantification of EVs has presented several challenges, predominantly due to the small size of vesicles such as exosomes and the availability of various technologies to measure nanosized particles, each technology having its own limitations. Materials and Methods: A standardized methodology to measure the concentration of extracellular vesicles (EVs has been developed and tested. The method is based on measuring the EV concentration as a function of a defined size range. Blood plasma EVs are isolated and purified using size exclusion columns (qEV and consecutively measured with tunable resistive pulse sensing (TRPS. Six independent research groups measured liposome and EV samples with the aim to evaluate the developed methodology. Each group measured identical samples using up to 5 nanopores with 3 repeat measurements per pore. Descriptive statistics and unsupervised multivariate data analysis with principal component analysis (PCA were used to evaluate reproducibility across the groups and to explore and visualise possible patterns and outliers in EV and liposome data sets. Results: PCA revealed good reproducibility within and between laboratories, with few minor outlying samples. Measured mean liposome (not filtered with qEV and EV (filtered with qEV concentrations had coefficients of variance of 23.9% and 52.5%, respectively. The increased variance of the EV concentration measurements could be attributed to the use of qEVs and the polydisperse nature of EVs. Conclusion: The results of this study demonstrate the feasibility of this standardized methodology to facilitate comparable and reproducible EV concentration measurements.

  19. Longitudinal prospective observational type study about determinants of renal resistive index variations in chronic renal failure patients treated with conventional medical and dietetic therapy

    Directory of Open Access Journals (Sweden)

    Simone Brardi

    2017-12-01

    Full Text Available Objective: This longitudinal prospective observational type study was conceived with the aim to examine the impact on renal resistive index (RRI of the variables that we can manipulate with therapeutic and or dietetic interventions in a chronic kidney disease population in order to known which of these variables was statistically related to changes in RRI and therefore could become the object of the greatest therapeutic effort. Material and methods: This study was undertaken between May 2016 to May 2017 in the outpatient nephrology and urology clinic of San Donato Hospital in Arezzo. The study population (84 patients: 47 males and 37 females was randomly selected among the chronic kidney patients (with various degrees of renal impairment affected by hypertension and or diabetes mellitus. After a comprehensive medical examination these patients were submitted to determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and finally renal Doppler ultrasonography. Then the patients were submitted to a full therapeutic and dietetic intervention to ameliorate the renal impairment by a wide range of actions and after on average a one-year interval were submitted again to a new medical examination and a second determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and a new renal Doppler ultrasonography too. Results: The comparison between basal and final data revealed a slight reduction in the mean of bilateral renal resistance indices (Delta RRI: -0.0182 ± 0.08, associated to a slight increase in the mean glomerular filtration rate (Delta GFR: 0.8738 ± 10.95 ml/min/1.73 m2, a reduction in mean body weight (Delta weight: -1.9548 ± 5.26 Kg and mean BMI (Delta BMI: -0.7643 ± 2.10 Kg/m2 as well as a reduction in the mean systolic blood pressure (Delta systolic blood pressure: -8.8333 ± 25.19 mmHg. Statistical analysis showed statistically significant correlations (p < 0.05 between

  20. Wide Bandgap Extrinsic Photoconductive Switches

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-07-03

    Semi-insulating Gallium Nitride, 4H and 6H Silicon Carbide are attractive materials for compact, high voltage, extrinsic, photoconductive switches due to their wide bandgap, high dark resistance, high critical electric field strength and high electron saturation velocity. These wide bandgap semiconductors are made semi-insulating by the addition of vanadium (4H and 6HSiC) and iron (2H-GaN) impurities that form deep acceptors. These deep acceptors trap electrons donated from shallow donor impurities. The electrons can be optically excited from these deep acceptor levels into the conduction band to transition the wide bandgap semiconductor materials from a semi-insulating to a conducting state. Extrinsic photoconductive switches with opposing electrodes have been constructed using vanadium compensated 6H-SiC and iron compensated 2H-GaN. These extrinsic photoconductive switches were tested at high voltage and high power to determine if they could be successfully used as the closing switch in compact medical accelerators.

  1. Determination of the corrosion rate of zinc by measuring the polarization resistance

    International Nuclear Information System (INIS)

    Roeschenbleck, B.; Koenig, W.

    1982-01-01

    Zinc is an important common metal. It should be noticeably attacked just by water as a result of its basic character. However, this is not the case, firstly because it tends to form protective layers and furthermore pure zinc has a high hydrogen overpressure. Zinc is often used as cathodic protection of iron. In order to assess the protective effect, the corrosion rate depending on the pH-value is important. A report is given here on the problems involved in determining these values. (orig./RW) [de

  2. Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. 1.2 This test method defines test specimens and methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice ball impact resistance is beyond the scope of this test method. 1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls. 1.5 This test method may be applied to concentrator and nonconcentrator modules. 1.6 The v...

  3. Balance between Apical Membrane Growth and Luminal Matrix Resistance Determines Epithelial Tubule Shape

    Directory of Open Access Journals (Sweden)

    Bo Dong

    2014-05-01

    Full Text Available The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape.

  4. Balance between apical membrane growth and luminal matrix resistance determines epithelial tubule shape.

    Science.gov (United States)

    Dong, Bo; Hannezo, Edouard; Hayashi, Shigeo

    2014-05-22

    The morphological stability of biological tubes is crucial for the efficient circulation of fluids and gases. Failure of this stability causes irregularly shaped tubes found in multiple pathological conditions. Here, we report that Drosophila mutants of the ESCRT III component Shrub/Vps32 exhibit a strikingly elongated sinusoidal tube phenotype. This is caused by excessive apical membrane synthesis accompanied by the ectopic accumulation and overactivation of Crumbs in swollen endosomes. Furthermore, we demonstrate that the apical extracellular matrix (aECM) of the tracheal tube is a viscoelastic material coupled with the apical membrane. We present a simple mechanical model in which aECM elasticity, apical membrane growth, and their interaction are three vital parameters determining the stability of biological tubes. Our findings demonstrate a mechanical role for the extracellular matrix and suggest that the interaction of the apical membrane and an elastic aECM determines the final morphology of biological tubes independent of cell shape. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  5. In Vitro Activity of Ertapenem versus Ceftriaxone against Neisseria gonorrhoeae Isolates with Highly Diverse Ceftriaxone MIC Values and Effects of Ceftriaxone Resistance Determinants: Ertapenem for Treatment of Gonorrhea?

    Science.gov (United States)

    Golparian, Daniel; Limnios, Athena; Whiley, David; Ohnishi, Makoto; Lahra, Monica M.; Tapsall, John W.

    2012-01-01

    Clinical resistance to the currently recommended extended-spectrum cephalosporins (ESCs), the last remaining treatment options for gonorrhea, is being reported. Gonorrhea may become untreatable, and new treatment options are crucial. We investigated the in vitro activity of ertapenem, relative to ceftriaxone, against N. gonorrhoeae isolates and the effects of ESC resistance determinants on ertapenem. MICs were determined using agar dilution technique or Etest for international reference strains (n = 17) and clinical N. gonorrhoeae isolates (n = 257), which included the two extensively drug-resistant (XDR) strains H041 and F89 and additional isolates with high ESC MICs, clinical ESC resistance, and other types of clinical high-level and multidrug resistance (MDR). Genetic resistance determinants for ESCs (penA, mtrR, and penB) were sequenced. In general, the MICs of ertapenem (MIC50 = 0.032 μg/ml; MIC90 = 0.064 μg/ml) paralleled those of ceftriaxone (MIC50 = 0.032 μg/ml; MIC90 = 0.125 μg/ml). The ESC resistance determinants mainly increased the ertapenem MIC and ceftriaxone MIC at similar levels. However, the MIC ranges for ertapenem (0.002 to 0.125 μg/ml) and ceftriaxone (gonorrhea, particularly for the currently identified ESC-resistant cases and possibly in a dual antimicrobial therapy regimen. However, further knowledge regarding the genetic determinants (and their evolution) conferring resistance to both antimicrobials, and clear correlates between genetic and phenotypic laboratory parameters and clinical treatment outcomes, is essential. PMID:22547617

  6. Lipooligosaccharide structure is an important determinant in the resistance of Neisseria gonorrhoeae to antimicrobial agents of innate host defense

    Directory of Open Access Journals (Sweden)

    Jacqueline T Balthazar

    2011-02-01

    Full Text Available The strict human pathogen Neisseria gonorrhoeae has caused the sexually transmitted infection termed gonorrhea for thousands of years. Over the millennia, the gonococcus has likely evolved mechanisms to evade host defense systems that operate on the genital mucosal surfaces in both males and females. Past research has shown that the presence or modification of certain cell envelope structures can significantly impact levels of gonococcal susceptibility to host-derived antimicrobial compounds that bathe genital mucosal surfaces and participate in innate host defense against invading pathogens. In order to facilitate the identification of gonococcal genes that are important in determining levels of bacterial susceptibility to mediators of innate host defense, we used the Himar I mariner in vitro mutagenesis system to construct a transposon insertion library in strain F62. As proof of principle that this strategy would be suitable for this purpose, we screened the library for mutants expressing decreased susceptibility to the bacteriolytic action of normal human serum (NHS. We found that a transposon insertion in the lgtD gene, which encodes an N-acetylgalactosamine transferase involved in the extension of the α-chain of lipooligosaccharide (LOS, could confer decreased susceptibility of strain F62 to complement-mediated killing by NHS. By complementation and chemical analyses, we demonstrated both linkage of the transposon insertion to the NHS-resistance phenotype and chemical changes in LOS structure that resulted from loss of LgtD production. Further truncation of the LOS α-chain or loss of phosphoethanolamine (PEA from the lipid A region of LOS also impacted levels of NHS-resistance. PEA decoration of lipid A also increased gonococcal resistance to the model cationic antimicrobial polymyxin B. Taken together, we conclude that the Himar I mariner in vitro mutagenesis procedure can facilitate studies on structures involved in gonococcal

  7. Radiation resistance of wide band gap n+/p AlInGaP solar cell for high-efficient multijunction space solar cells

    International Nuclear Information System (INIS)

    Lee, Hae-Seok; Yamaguchi, Masafumi; Ekins-Daukes, Nicholas J.; Khan, Aurangzeb; Takamoto, Tatsuya; Imaizumi, Mitsuru; Ohshima, Takeshi; Itoh, Hisayoshi

    2007-01-01

    The effects of 30 keV proton irradiation on n + /p AlInGaP solar cells are presented here. As the proton fluence increases to more than 1x10 10 cm -2 , the maximum power P max of the cell decreases markedly due to the introduction of defects by proton irradiation. From the changes in minority-carrier diffusion length determined by quantum efficiency modeling as a function of fluence, the damage constant K L for p-AlInGaP was estimated to be about 5.0x10 -5 . This value is comparable to that observed from 3 MeV proton-irradiated p-InGaP whereas it is lower than that observed from 3 MeV proton-irradiated p-InGaAsP and p-InGaAs cells. The maximum power recovery of the cell was observed by minority-carrier-injection-enhanced annealing (1 A/cm 2 ), and the annealing activation energy for 30 keV proton-irradiation-induced defects in p-AlInGaP was determined as ΔE=0.42 eV. (author)

  8. Genome-Wide Association Study among Four Horse Breeds Identifies a Common Haplotype Associated with In Vitro CD3+ T Cell Susceptibility/Resistance to Equine Arteritis Virus Infection ▿

    Science.gov (United States)

    Go, Yun Young; Bailey, Ernest; Cook, Deborah G.; Coleman, Stephen J.; MacLeod, James N.; Chen, Kuey-Chu; Timoney, Peter J.; Balasuriya, Udeni B. R.

    2011-01-01

    Previously, we have shown that horses could be divided into susceptible and resistant groups based on an in vitro assay using dual-color flow cytometric analysis of CD3+ T cells infected with equine arteritis virus (EAV). Here, we demonstrate that the differences in in vitro susceptibility of equine CD3+ T lymphocytes to EAV infection have a genetic basis. To investigate the possible hereditary basis for this trait, we conducted a genome-wide association study (GWAS) to compare susceptible and resistant phenotypes. Testing of 267 DNA samples from four horse breeds that had a susceptible or a resistant CD3+ T lymphocyte phenotype using both Illumina Equine SNP50 BeadChip and Sequenom's MassARRAY system identified a common, genetically dominant haplotype associated with the susceptible phenotype in a region of equine chromosome 11 (ECA11), positions 49572804 to 49643932. The presence of a common haplotype indicates that the trait occurred in a common ancestor of all four breeds, suggesting that it may be segregated among other modern horse breeds. Biological pathway analysis revealed several cellular genes within this region of ECA11 encoding proteins associated with virus attachment and entry, cytoskeletal organization, and NF-κB pathways that may be associated with the trait responsible for the in vitro susceptibility/resistance of CD3+ T lymphocytes to EAV infection. The data presented in this study demonstrated a strong association of genetic markers with the trait, representing de facto proof that the trait is under genetic control. To our knowledge, this is the first GWAS of an equine infectious disease and the first GWAS of equine viral arteritis. PMID:21994447

  9. IGF-1 and Insulin Resistance Are Major Determinants of Common Carotid Artery Thickness in Morbidly Obese Young Patients.

    Science.gov (United States)

    Sirbu, Anca; Nicolae, Horia; Martin, Sorina; Barbu, Carmen; Copaescu, Catalin; Florea, Suzana; Panea, Cristina; Fica, Simona

    2016-03-01

    We assessed the relationship between insulin resistance, serum insulin-like growth factor 1 (IGF-1) levels, and common carotid intima-media thickness (CC-IMT) in morbidly obese young patients. A total of 249 patients (aged 37.9 ± 9.8 years, body mass index [BMI] 45.6 ± 8.3 kg/m(2)) were evaluated (metabolic tests, serum IGF-1 measurements, homeostasis model assessment-insulin resistance [HOMA-IR], and ultrasonographically assessed CC-IMT) in a research program for bariatric surgery candidates. After adjusting for age, gender, BMI, systolic blood pressure, uric acid, antihypertensive and lipid-lowering treatment, metabolic syndrome, and metabolic class, both HOMA-IR and IGF-1 z-score were significantly associated with CC-IMT. These results were confirmed in logistic regression analysis, in which age (β = 1.11, P = .001), gender (β = 3.19, P = .001), HOMA-IR (β = 1.221, P = .005), and IGF-1 z-score (β = 1.734, P = .009) were the only independent determinants of abnormal CC-IMT, presumably modulating the effect of the other risk factors included in the regression. Area under the receiver-operating characteristic curve for the model was 0.841 (confidence interval: 0.776-0.907; P IGF-1 z-score are significantly associated with CC-IMT, independent of other major cardiovascular risk factors. © The Author(s) 2015.

  10. Enhanced proline synthesis may determine resistance to salt stress in tomato cultivars

    International Nuclear Information System (INIS)

    Ali, S.; Khan, N.U.

    2011-01-01

    The physiological and biochemical responses of tomato cultivars were studied at Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan during 2005-2006 for salt tolerance. Tomato cultivars were Roma Rio Super, Roma V.F., Chinese 87-5, Rio Grand and Super Blocky and subjected to salt stress (75 mM NaCl). Fresh weight, dry weight, and ions sodium and potassium accumulation, Na/sup +/K sup +/ ratio and proline content were determined after imposing the tomato cultivars to NaCl salt for 80 days. Salt stress significantly decreased the fresh and dry weight in Roma Rio Super, Roma V.F, Chinese 87-5 and Rio Grand, however, in Super Blocky the fresh and dry weight were enhanced under stress conditions. Salinity stress increased sodium uptake from 191.828 to 436.170 mu mg/sup -1/ D wt while potassium accumulation decreased from 1033.12 to 926.80 mu mg/sup -1/ D wt resulting in higher Na/sup +/ ratio in stressed (0.48 g) as compared to unstressed control (0.19). The mean proline contents also increased from 28.95 to 40.96 mu M Proline g/sup -1/ F. wt with the maximum increase (57.378%) in Super Blocky followed by Rio Grand (49.325%). (author)

  11. Molecular screening of antibiotic-resistant determinants among multidrug-resistant clinical isolates of Proteus mirabilis from SouthWest Nigeria.

    Science.gov (United States)

    Alabi, Olumuyiwa Samuel; Mendonça, Nuno; Adeleke, Olufemi Ezekiel; da Silva, Gabriela Jorge

    2017-06-01

    Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating problem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. This study screened for presence of transferable resistance genes and mobile genetic elements (MGEs) such as integron among multi-drug resistant (MDR) P. mirabilis . A total of 108 P. mirabilis strains collected from five tertiary hospitals in SouthWest Nigeria were subjected to antibiotic susceptibility study using disc-diffusion method. Transferable resistance genes and MGEs were amplified using Polymerase chain reaction (PCR) analysis and amplicons sequenced. Varied resistance was observed against all the antibiotics tested. About 56% of the isolates were MDR including those from 0-12 years old children. PCR analysis revealed the presence of aac(6')-Ib (33.3%), plasmid mediated quinolone resistance (PMQR) genes [qnrA (36.7%), acc(6')-Ib-cr (5%)], TEM (48.3%), CTX-M (6.7%) and integrons class 1 (58.3%) and class 2 (26.7%). Sequencing analysis revealed bla TEM-1 , bla CTX-M-15 associated with IS Ecp1 and eight different arrays of gene cassettes: aadA1, aadA1-qacH, aadB-aadA2, aadA5, dfrA7, dfrA15, dfrA17, dfrA17-aadA5 . Transferable resistance genes in association with MGEs are present in Nigerian P. mirabilis thus their potential in disseminating resistance.

  12. Standard Practice for Determining Resistance of Solar Collector Covers to Hail by Impact With Propelled Ice Balls

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This practice covers a procedure for determining the ability of cover plates for flat-plate solar collectors to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. This practice is not intended to apply to photovoltaic cells or arrays. 1.2 This practice defines two types of test specimens, describes methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, and specifies parameters that must be recorded and reported. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice-ball impact resistance is beyond the scope of this practice. 1.4 The size of ice ball to be used in conducting this test is not specified in this practice. This practice can be used with various sizes of ice balls. 1.5 The categories of solar collector cover plat...

  13. Load and resistance factor design calibration to determine a resistance factor for the modification of the Kansas Department of Transportation-Engineering News Record formula.

    Science.gov (United States)

    2014-02-01

    This report contains the results of a study describing the development of resistance factors for use : with the Kansas Department of Transportation (KDOT) Engineering News Record (ENR) formula for driven : piles. KDOT has verified driven pile resista...

  14. Overexpression of Aldo-Keto-Reductase in Azole-resistant Clinical Isolates of Candida Glabrata Determined by cDNA-AFLP

    Directory of Open Access Journals (Sweden)

    Mansour Heidari

    2013-01-01

    Full Text Available Background: Candida glabrata causes significant medical problems in immunocompromised patients. Many strains of this yeast are intrinsically resistant to azole antifungal agents, and treatment is problematic, leading to high morbidity and mortality rates in immunosuppressed individuals. The primary goal of this study was to investigate the genes involved in the drug resistance of clinical isolates of C. glabrata.Methods: The clinical isolates of C. glabrata were collected in an epidemiological survey of candidal infection inimmunocompromised patients and consisted of four fluconazole and itraconazole resistant isolates, two fluconazoleand itraconazole sensitive isolates, and C. glabrata CBS 138 as reference strain. Antifungal susceptibility patterns ofthe organisms were determined beforehand by the Clinical and Laboratory Standards Institute (CLSI. The potentialgene(s implicated in antifungal resistance were investigated using complementary DNA- Amplified Fragment Length Polymorphism (cDNA-AFLP. Semi-quantitative RT-PCR was carried out to evaluate the expression of gene(s in resistant isolates as compared to sensitive and reference strains.Results and conclusions: The aldo-keto-reductase superfamily (AKR gene was upregulated in the resistant clinicalisolates as assessed by cDNA-AFLP. Semi-quantitative RT-PCR revealed AKR mRNA expression approximately twice that seen in the sensitive isolates. Overexpression of the AKR gene was associated with increased fluconazole and itraconazole resistance in C. glabrata. The data suggest that upregulation of the AKR gene might give a new insight into the mechanism of azole resistance.

  15. Longitudinal prospective observational type study about determinants of renal resistive index variations in chronic renal failure patients treated with conventional medical and dietetic therapy.

    Science.gov (United States)

    Brardi, Simone; Cevenini, Gabriele; Giovannelli, Vanni; Romano, Giuseppe

    2017-12-31

    This longitudinal prospective observational type study was conceived with the aim to examine the impact on renal resistive index (RRI) of the variables that we can manipulate with therapeutic and or dietetic interventions in a chronic kidney disease population in order to known which of these variables was statistically related to changes in RRI and therefore could become the object of the greatest therapeutic effort. This study was undertaken between May 2016 to May 2017 in the outpatient nephrology and urology clinic of San Donato Hospital in Arezzo. The study population (84 patients: 47 males and 37 females) was randomly selected among the chronic kidney patients (with various degrees of renal impairment) affected by hypertension and or diabetes mellitus. After a comprehensive medical examination these patients were submitted to determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and finally renal Doppler ultrasonography. Then the patients were submitted to a full therapeutic and dietetic intervention to ameliorate the renal impairment by a wide range of actions and after on average a one-year interval were submitted again to a new medical examination and a second determination of serum creatinine, glycated hemoglobin, 24-hour urinary albumin excretion and a new renal Doppler ultrasonography too. The comparison between basal and final data revealed a slight reduction in the mean of bilateral renal resistance indices (Delta RRI: -0.0182 ± 0.08), associated to a slight increase in the mean glomerular filtration rate (Delta GFR: 0.8738 ± 10.95 ml/min/1.73 m2), a reduction in mean body weight (Delta weight: -1.9548 ± 5.26 Kg) and mean BMI (Delta BMI: -0.7643 ± 2.10 Kg/m2) as well as a reduction in the mean systolic blood pressure (Delta systolic blood pressure: -8.8333 ± 25.19 mmHg). Statistical analysis showed statistically significant correlations (p chronic renal failure and as a valuable tool to drive the clinical

  16. In vitro transfer of methicillin resistance determinants mecA from methicillin resistant Staphylococcus aureus (MRSA) to methicillin susceptible Staphylococcus aureus (MSSA).

    Science.gov (United States)

    Bitrus, Asinamai Athliamai; Zunita, Zakaria; Bejo, Siti Khairani; Othman, Sarah; Nadzir, Nur Adilah Ahmad

    2017-04-04

    Staphylococcus aureus more than any other human pathogen is a better model for the study of the adaptive evolution of bacterial resistance to antibiotics, as it has demonstrated a remarkable ability in its response to new antibiotics. This study was designed to investigate the in vitro transfer of mecA gene from methicillin resistant S. aureus to methicillin susceptible S. aureus. The recipient transconjugants were resistant to erythromycin, cefpodoxime and were mecA positive. PCR amplification of mecA after mix culture plating on Luria Bertani agar containing 100 μg/mL showed that 75% of the donor and 58.3% of the recipient transconjugants were mecA positive. Additionally, 61.5% of both the donor cells and recipient transconjugants were mecA positive, while 46.2% and 41.75% of both donor and recipient transconjugants were mecA positive on LB agar containing 50 μg/mL and 30 μg/mL respectively. In this study, the direction of transfer of phenotypic resistance as well as mecA was observed to have occurred from the donor to the recipient strains. This study affirmed the importance of horizontal transfer events in the dissemination of antibiotics resistance among different strains of MRSA.

  17. Determination of residence times of ions in a resistive glass selected ion flow-drift tube using the Hadamard transformation.

    Science.gov (United States)

    Spesyvyi, Anatolii; Španěl, Patrik

    2015-09-15

    Selected ion flow tube mass spectrometry, SIFT-MS, used for trace gas analyses has certain fundamental limitations that could be alleviated by adding a facility that allows reaction times and ion interaction energies to be varied. Thus, a selected ion flow-drift tube, SIFDT, has been created to explore the influence of an embedded electric field on these parameters and on reaction processes. The new SIFTD instrument was constructed using a miniature resistive glass drift tube. Arrival times of ions, t, analysed by a downstream quadrupole mass spectrometer over the m/z range 10-100 were studied by modulating the injected ion current using a gate lens. Single pulse modulation was compared with pseudorandom time multiplexing exploiting the Hadamard transformation. A simple model involving analysis of ethanol and water vapour mixture in air was used to explore the advantages of the SIFDT concept to SIFT-MS analysis. It is shown that the resistive glass drift tube is suitable for SIFDT experiments. The Hadamard transformation can be used to routinely determine reagent ion residence time in the flow-drift tube and also to observe differences in arrival times for different product ions. Two-dimensional data combining arrival time and mass spectra can be obtained rapidly. The calculated ion drift velocities vary with the reduced field strength, E/N, and the calculated ion mobilities agree with theoretical and previous literature values. This study has provided evidence that the SIFDT-MS technique can be implemented in a miniature and low-cost instrument and two- or three-dimensional data can be obtained (product ion count rates as functions of m/z, t and E/N) using the Hadamard transformation thus providing exciting possibilities for further analytical additions and extensions of the SIFT-MS technique. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Determination of tetracycline resistance genes in Vibrio cholerae O1 biotype El Tor serotype Inaba strains isolated from outbreaks occurred in Iran in 2013

    Directory of Open Access Journals (Sweden)

    Azin Khany

    2016-05-01

    Full Text Available V. cholerae is the causative agent of potentially life threatening diarrheal disease named as cholera. Cholera is an endemic disease in Iran. Encountered increasing resistance of V. cholerae to commonly used antibiotics such as tetracycline has led to major challenges in the treatment of this disease .The present study was carried out to determine the prevalence of drug resistance as well as molecular bases of resistant V.cholerae strains which were isolated from patients in cholera outbreaks during summer of 2013 in Iran. Susceptibly testing was performed on V.cholerae strains isolated from stool of patients suffering from cholera in Iranian reference health laboratory by E -test MIC method as recommended by CLSI guideline. Antibiotic strips used included Ampicillin, Ciprofloxacin, Nalidixic acid, Cefixime , Tetracycline, Erythromycin and Trimethoprim-sulfamethoxazole .Regarding observed dominant pattern of tetracycline resistance comparing to results of previous years ,we decided to confirm the resistance by detecting the tetA , tetB and tetC by Polymerase chain reaction method. The results of antibiotic susceptibility testing revealed 100% resistance of isolated strains to tetracycline. Data obtained from PCR reaction on resistant strains for tetA, tetB and tetC showed that 45(44.1%, 37(36.2% and 70(68.6% were containing tetA, tetB and tetC gene respectively. Moreover, the frequency of tetA+tetB, tetA+C, tetB+tetC , tetA+tetB+tetC also were determined as 9(8.8%, 32(31.3%, 19(18.6% and 8(7.8% respectively. This study revealed the pattern of drug resistance distribution of isolates harboring tetA, tetB, tetC genes in relation to sex, age and nationality of patients and the cities where the cases were reported. A significant correlation was obtained between reported geographical incidence and drug resistant strains.

  19. Genome-wide meta-analysis identifies regions on 7p21 (AHR and 15q24 (CYP1A2 as determinants of habitual caffeine consumption.

    Directory of Open Access Journals (Sweden)

    Marilyn C Cornelis

    2011-04-01

    Full Text Available We report the first genome-wide association study of habitual caffeine intake. We included 47,341 individuals of European descent based on five population-based studies within the United States. In a meta-analysis adjusted for age, sex, smoking, and eigenvectors of population variation, two loci achieved genome-wide significance: 7p21 (P = 2.4 × 10(-19, near AHR, and 15q24 (P = 5.2 × 10(-14, between CYP1A1 and CYP1A2. Both the AHR and CYP1A2 genes are biologically plausible candidates as CYP1A2 metabolizes caffeine and AHR regulates CYP1A2.

  20. NIRS determination of non-structural carbohydrates, water soluble carbohydrates and other nutritive quality traits in whole plant maize with wide range variability

    OpenAIRE

    L. Campo; A. B. Monteagudo; B. Salleres; P. Castro; J. Moreno-Gonzalez

    2013-01-01

    The aim of this work was to study the potential of near-infrared reflectance spectroscopy (NIRS) to predict non-structural carbohydrates (NSC), water soluble carbohydrates (WSC), in vitro organic dry matter digestibility (IVOMD), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and starch in samples of whole plant maize with a wide range of variability. The samples were analyzed in reflectance mode by a spectrophotometer FOSS NIRSystems 6500. ...

  1. Characterization of CTX-M enzymes, quinolone resistance determinants, and antimicrobial residues from hospital sewage, wastewater treatment plant, and river water.

    Science.gov (United States)

    Conte, Danieli; Palmeiro, Jussara Kasuko; da Silva Nogueira, Keite; de Lima, Thiago Marenda Rosa; Cardoso, Marco André; Pontarolo, Roberto; Degaut Pontes, Flávia Lada; Dalla-Costa, Libera Maria

    2017-02-01

    Multidrug-resistant (MDR) bacteria are widespread in hospitals and have been increasingly isolated from aquatic environments. The aim of the present study was to characterize extended-spectrum β-lactamase (ESBL) and quinolone-resistant Enterobacteriaceae from a hospital effluent, sanitary effluent, inflow sewage, aeration tank, and outflow sewage within a wastewater treatment plant (WWTP), as well as river water upstream and downstream (URW and DRW, respectively), of the point where the WWTP treated effluent was discharged. β-lactamase (bla) genes, plasmid-mediated quinolone resistance (PMQR), and quinolone resistance-determining regions (QRDRs) were assessed by amplification and sequencing in 55 ESBL-positive and/or quinolone-resistant isolates. Ciprofloxacin residue was evaluated by high performance liquid chromatography. ESBL-producing isolates were identified in both raw (n=29) and treated (n=26) water; they included Escherichia coli (32), Klebsiella pneumoniae (22) and Klebsiella oxytoca (1). Resistance to both cephalosporins and quinolone was observed in 34.4% of E. coli and 27.3% of K. pneumoniae. Resistance to carbapenems was found in 5.4% of K. pneumoniae and in K. oxytoca. Results indicate the presence of bla CTX-M (51/55, 92.7%) and bla SHV (8/55, 14.5%) ESBLs, and bla GES (2/55, 3.6%) carbapenemase-encoding resistance determinants. Genes conferring quinolone resistance were detected at all sites, except in the inflow sewage and aeration tanks. Quinolone resistance was primarily attributed to amino acid substitutions in the QRDR of GyrA (47%) or to the presence of PMQR (aac-(6')-Ib-cr, oqxAB, qnrS, and/or qnrB; 52.9%) determinants. Ciprofloxacin residue was absent only from URW. Our results have shown strains carrying ESBL genes, PMQR determinants, and mutations in the gyrA QRDR genes mainly in hospital effluent, URW, and DRW samples. Antimicrobial use, and the inefficient removal of MDR bacteria and antibiotic residue during sewage treatment, may

  2. Transcriptome Response to Heavy Metals in Sinorhizobium meliloti CCNWSX0020 Reveals New Metal Resistance Determinants That Also Promote Bioremediation by Medicago lupulina in Metal-Contaminated Soil.

    Science.gov (United States)

    Lu, Mingmei; Jiao, Shuo; Gao, Enting; Song, Xiuyong; Li, Zhefei; Hao, Xiuli; Rensing, Christopher; Wei, Gehong

    2017-10-15

    The symbiosis of the highly metal-resistant Sinorhizobium meliloti CCNWSX0020 and Medicago lupulina has been considered an efficient tool for bioremediation of heavy metal-polluted soils. However, the metal resistance mechanisms of S. meliloti CCNWSX00200 have not been elucidated in detail. Here we employed a comparative transcriptome approach to analyze the defense mechanisms of S. meliloti CCNWSX00200 against Cu or Zn exposure. Six highly upregulated transcripts involved in Cu and Zn resistance were identified through deletion mutagenesis, including genes encoding a multicopper oxidase (CueO), an outer membrane protein (Omp), sulfite oxidoreductases (YedYZ), and three hypothetical proteins (a CusA-like protein, a FixH-like protein, and an unknown protein), and the corresponding mutant strains showed various degrees of sensitivity to multiple metals. The Cu-sensitive mutant (Δ cueO ) and three mutants that were both Cu and Zn sensitive (Δ yedYZ , Δ cusA -like, and Δ fixH -like) were selected for further study of the effects of these metal resistance determinants on bioremediation. The results showed that inoculation with the Δ cueO mutant severely inhibited infection establishment and nodulation of M. lupulina under Cu stress, while inoculation with the Δ yedYZ and Δ fixH -like mutants decreased just the early infection frequency and nodulation under Cu and Zn stresses. In contrast, inoculation with the Δ cusA -like mutant almost led to loss of the symbiotic capacity of M. lupulina to even grow in uncontaminated soil. Moreover, the antioxidant enzyme activity and metal accumulation in roots of M. lupulina inoculated with all mutants were lower than those with the wild-type strain. These results suggest that heavy metal resistance determinants may promote bioremediation by directly or indirectly influencing formation of the rhizobium-legume symbiosis. IMPORTANCE Rhizobium-legume symbiosis has been promoted as an appropriate tool for bioremediation of heavy

  3. Tetracycline resistance and presence of tetracycline resistance determinants .i.tet./i.(V) and .i.tap./i. in rapidly growing mycobacteria from agricultural soils and clinical isolates

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Chroňáková, Alica; Volná, Lucie; Němec, Jan; Ulmann, V.; Scharfen, J.; Elhottová, Dana

    2012-01-01

    Roč. 27, č. 4 (2012), s. 413-422 ISSN 1342-6311 R&D Projects: GA ČR GAP504/10/2077; GA MŠk LC06066 Institutional support: RVO:60077344 Keywords : efflux pump * rapidly growing Mycobacterium * tetracycline resistance * tap * tet (V) Subject RIV: EH - Ecology, Behaviour Impact factor: 2.444, year: 2012

  4. Comparison of in vitro efficacy of linezolid and vancomycin by determining their minimum inhibitory concentrations against methicillin resistant Staphylococcus aureus (MRSA)

    International Nuclear Information System (INIS)

    Kaleem, F.; Usman, J.; Hassan, A.

    2011-01-01

    Objectives: To compare the in vitro activities of vancomycin and linezolid against methicillin resistant Staphyloccus aureus in our set up to help in formulating a better empirical treatment and reduce the emergence of vancomycin resistant Staphylococcus aureus. Methods: The study was conducted over a period of 6 months(July 1, 2009 - Dec 1, 2009). Fifty Methicillin resistant Staphylococcus aureus isolated from the clinical isolates of Military Hospital Rawalpindi were subjected to the determination of Minimum inhibitory concentrations of linezolid and vancomycin using E-strips. Results: All the isolated organisms were uniformly susceptible to both the antibiotics. Vancomycin showed higher minimum inhibitory concentrations (MICs) as compared to linezolid MICs. Conclusion: This study suggests that linezolid and vancomycin have similar in vitro efficacy for methicillin resistant Staphyloccus aureus infections. (author)

  5. Determining the boundary of inclusions with known conductivities using a Levenberg–Marquardt algorithm by electrical resistance tomography

    International Nuclear Information System (INIS)

    Tan, Chao; Xu, Yaoyuan; Dong, Feng

    2011-01-01

    Electrical resistance tomography (ERT) is a non-intrusive technique to image the electrical conductivity distribution of a closed vessel by injecting exciting current into the vessel and measuring the boundary voltages induced. ERT image reconstruction is characterized as a severely nonlinear and ill-posed inverse problem with many unknowns. In recent years, a growing number of papers have been published which aim to determine the locations and shapes of inclusions by assuming that their conductivities are piecewise constant and isotropic. In this work, the boundary of inclusions is reconstructed by ERT with a boundary element method. The Jacobian matrix of the forward problem is first calculated with a direct linearization method based on the boundary element, and validated through comparison with that determined by the finite element method and analytical method. A boundary reconstruction algorithm is later presented based on the Levenberg–Marquardt (L-M) method. Several numerical simulations and static experiments were conducted to study the reconstruction quality, where much importance was given to the smoothness of boundaries in the reconstruction; thus, a restriction of the curve radius is introduced to adjust the damping parameter for the L-M algorithm. Analytical results on the stability and precision of the boundary reconstruction demonstrate that stable reconstruction can be achieved when the conductivity of the objects differs much from that of the background medium, and convex boundaries can also be precisely reconstructed. Contrarily, the reconstructions for inclusions with similar conductivities to the background medium are not stable. The situation of an incorrect initial estimation of the inclusions' number is numerically studied and the results show that the boundary of inclusions could be correctly reconstructed with a splitting/merging function under the aforementioned proper operation condition of the present algorithm

  6. Prevalence of quinolone resistance determinant qnrA6 among broad- and extended-spectrum beta-lactam-resistant Proteus mirabilis and Morganella morganii clinical isolates with sul1-type class 1 integron association in a Tunisian Hospital.

    Science.gov (United States)

    Mahrouki, Sihem; Perilli, Mariagrazia; Bourouis, Amel; Chihi, Hela; Ferjani, Mustapha; Ben Moussa, Mohamed; Amicosante, Gianfranco; Belhadj, Omrane

    2013-08-01

    The aim of this study was to investigate the prevalence and the emergence of plasmid-mediated quinolone resistance among broad-spectrum beta-lactam-resistant Proteus mirabilis and Morganella morganii clinical isolates recovered in the Military Hospital in Tunisia. Of 200 strains examined, 50 exhibited resistance to quinolones. Quinolone resistance determinants (qnr and aac(6')-Ib-cr) were characterized by multiplex PCR and sequencing. Chromosomal quinolone resistance mutations in the quinolone resistance-determining region (QRDR) and class 1 integron characterization were analysed by PCR and sequencing. The clonal relationship between the isolates was studied by pulsed-field gel electrophoresis (PFGE). Fourteen isolates harboured qnrA6 and among them 8 (57%) were extended-spectrum beta-lactamase (ESBL) producers, whilst 12 (85%) isolates harboured blaDHA-1. Mutations in the QRDR were detected in gyrA (Ser83Ile, Glu87Lys), gyrB (Ser464Phe), and parC (Ser80Ile). qnrA6 and blaDHA-1 genes were found embedded in complex sul1-type class 1 integrons. A gene cassette carrying aac(6')-Ib-cr was found located in the class 1 integron upstream of the qacEΔ1 gene. According to the PFGE analysis, the isolates were clonally unrelated. This is the first description in North Africa of class 1 integrons carrying blaDHA-1, qnrA6 gene, and aac(6')-Ib-cr determinants in clinical strains of Proteus mirabilis and Morganella morganii.

  7. Determination of antimicrobial resistance of Enterococcus strains isolated from pigs and their genotypic characterization by method of amplification of DNA fragments surrounding rare restriction sites (ADSRRS fingerprinting).

    Science.gov (United States)

    Nowakiewicz, Aneta; Ziółkowska, Grażyna; Trościańczyk, Aleksandra; Zięba, Przemysław; Gnat, Sebastian

    2017-03-01

    In this study, we analysed phenotypic resistance profiles and their reflection in the genomic profiles of Enterococcus spp. strains isolated from pigs raised on different farms. Samples were collected from five pig farms (n=90 animals) and tested for Enterococcus. MICs of 12 antimicrobials were determined using the broth microdilution method, and epidemiological molecular analysis of strains belonging to selected species (faecalis, faecium and hirae) was performed using the ADSRRS-fingerprinting (amplification of DNA fragments surrounding rare restriction sites) method with a few modifications. The highest percentage of strains was resistant to tetracycline (73.4 %), erythromycin and tylosin (42.5 %) and rifampin (25.2 %), and a large number of strains exhibited high-level resistance to both kanamycin (25.2 %) and streptomycin (27.6 %). The strains of E. faecalis, E. faecium and E. hirae (n=184) revealed varied phenotypic resistance profiles, among which as many as seven met the criteria for multidrug resistance (30.4 % of strains tested). ADSRRS-fingerprinting analysis produced 17 genotypic profiles of individual strains which were correlated with their phenotypic resistance profiles. Only E. hirae strains susceptible to all of the chemotherapeutics tested had two different ADSRRS profiles. Moreover, eight animals were carriers of more than one genotype belonging to the same Enterococcus spp., mainly E. faecalis. Given the possibility of transmission to humans of the high-resistance/multidrug resistance enterococci and the significant role of pigs as food animals in this process, it is necessary to introduce a multilevel control strategy by carrying out research on the resistance and molecular characteristics of indicator bacterial strains isolated from animals on individual farms.

  8. A New Method for Blood NT-proBNP Determination Based on a Near-infrared Point of Care Testing Device with High Sensitivity and Wide Scope.

    Science.gov (United States)

    Zhang, Xiao Guang; Shu, Yao Gen; Gao, Ju; Wang, Xuan; Liu, Li Peng; Wang, Meng; Cao, Yu Xi; Zeng, Yi

    2017-06-01

    To develop a rapid, highly sensitive, and quantitative method for the detection of NT-proBNP levels based on a near-infrared point-of-care diagnostic (POCT) device with wide scope. The lateral flow assay (LFA) strip of NT-proBNP was first prepared to achieve rapid detection. Then, the antibody pairs for NT-proBNP were screened and labeled with the near-infrared fluorescent dye Dylight-800. The capture antibody was fixed on a nitrocellulose membrane by a scribing device. Serial dilutions of serum samples were prepared using NT-proBNP-free serum series. The prepared test strips, combined with a near-infrared POCT device, were validated by known concentrations of clinical samples. The POCT device gave the output of the ratio of the intensity of the fluorescence signal of the detection line to that of the quality control line. The relationship between the ratio value and the concentration of the specimen was plotted as a work curve. The results of 62 clinical specimens obtained from our method were compared in parallel with those obtained from the Roche E411 kit. Based on the log-log plot, the new method demonstrated that there was a good linear relationship between the ratio value and NT-proBNP concentrations ranging from 20 pg/mL to 10 ng/mL. The results of the 62 clinical specimens measured by our method showed a good linear correlation with those measured by the Roche E411 kit. The new LFA detection method of NT-proBNP levels based on the near-infrared POCT device was rapid and highly sensitive with wide scope and was thus suitable for rapid and early clinical diagnosis of cardiac impairment. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  9. Economic Differentiation as a Determinant of Higher Education Pricing and Expenditure Policies and State-wide Public Policy: Implications for Governance. ASHE 1983 Annual Meeting Paper.

    Science.gov (United States)

    Alfred, Richard L.

    A study of the impact of economic differentiation on institutional pricing and expenditure policies, higher education public policy, and governance in public colleges and universities is described. It is suggested that economic differentiation is a likely determinant of variation in institutional expenditure and pricing policies and higher…

  10. Determination of coagulation inhibitor levels and resistance to activated protein C in patients undergoing gastric surgery for benign and malignant disorders

    DEFF Research Database (Denmark)

    Andersen, B S; Rahr, H B; Sørensen, J V

    1997-01-01

    The aim of the present study was to determine plasma levels of protein C antigen (PC:Ag) and activity (PC:Act), tissue factor pathway inhibitor (TFPI), protein S (PS), antithrombin (AT), heparin cofactor II (HCII), and resistance to activated protein C (APCR) before, during and after elective gas...

  11. Oridonin Targets Multiple Drug-Resistant Tumor Cells as Determined by in Silico and in Vitro Analyses

    Directory of Open Access Journals (Sweden)

    Onat Kadioglu

    2018-04-01

    Full Text Available Drug resistance is one of the main reasons of chemotherapy failure. Therefore, overcoming drug resistance is an invaluable approach to identify novel anticancer drugs that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients for effective chemotherapy. Oridonin is a cytotoxic diterpenoid isolated from Rabdosia rubescens with in vivo anticancer activity. In the present study, we evaluated the cytotoxicity of oridonin toward a panel of drug-resistant cancer cells overexpressing ABCB1, ABCG2, or ΔEGFR or with a knockout deletion of TP53. Interestingly, oridonin revealed lower degree of resistance than the control drug, doxorubicin. Molecular docking analyses pointed out that oridonin can interact with Akt/EGFR pathway proteins with comparable binding energies and similar docking poses as the known inhibitors. Molecular dynamics results validated the stable conformation of oridonin docking pose on Akt kinase domain. Western blot experiments clearly revealed dose-dependent downregulation of Akt and STAT3. Pharmacogenomics analyses pointed to a mRNA signature that predicted sensitivity and resistance to oridonin. In conclusion, oridonin bypasses major drug resistance mechanisms and targets Akt pathway and might be effective toward drug refractory tumors. The identification of oridonin-specific gene expressions may be useful for the development of personalized treatment approaches.

  12. Biochemical identification and determination of antimicrobial resistance in clinical isolates of anaerobic bacteria obtained from the Hospital San Juan de Dios in the period 2009 to 2011

    International Nuclear Information System (INIS)

    Meza Pena, Maria Daniela

    2014-01-01

    Clinical isolates of 81 anaerobic bacteria isolated are identified to patients of the Hospital San Juan de Dios, between 2009 to 2011; by algorithms that have employed biochemical methods of reference chemical samples. Antimicrobial resistance is determined. The miniaturized methods and biochemical algorithms proposed were compared to identify differences between methods. The minimum inhibitory concentration of metronidazole, clindamycin, amoxicillin, tetracycline and cefotaxime are determined to 81 anaerobic bacteria isolated from the Hospital mentioned [es

  13. Human Management of a Wild Plant Modulates the Evolutionary Dynamics of a Gene Determining Recessive Resistance to Virus Infection.

    Science.gov (United States)

    Poulicard, Nils; Pacios, Luis Fernández; Gallois, Jean-Luc; Piñero, Daniel; García-Arenal, Fernando

    2016-08-01

    This work analyses the genetic variation and evolutionary patterns of recessive resistance loci involved in matching-allele (MA) host-pathogen interactions, focusing on the pvr2 resistance gene to potyviruses of the wild pepper Capsicum annuum glabriusculum (chiltepin). Chiltepin grows in a variety of wild habitats in Mexico, and its cultivation in home gardens started about 25 years ago. Potyvirus infection of Capsicum plants requires the physical interaction of the viral VPg with the pvr2 product, the translation initiation factor eIF4E1. Mutations impairing this interaction result in resistance, according to the MA model. The diversity of pvr2/eIF4E1 in wild and cultivated chiltepin populations from six biogeographical provinces in Mexico was analysed in 109 full-length coding sequences from 97 plants. Eleven alleles were found, and their interaction with potyvirus VPg in yeast-two-hybrid assays, plus infection assays of plants, identified six resistance alleles. Mapping resistance mutations on a pvr2/eIF4E1 model structure showed that most were around the cap-binding pocket and strongly altered its surface electrostatic potential, suggesting resistance-associated costs due to functional constraints. The pvr2/eIF4E1 phylogeny established that susceptibility was ancestral and resistance was derived. The spatial structure of pvr2/eIF4E1 diversity differed from that of neutral markers, but no evidence of selection for resistance was found in wild populations. In contrast, the resistance alleles were much more frequent, and positive selection stronger, in cultivated chiltepin populations, where diversification of pvr2/eIF4E1 was higher. This analysis of the genetic variation of a recessive resistance gene involved in MA host-pathogen interactions in populations of a wild plant show that evolutionary patterns differ according to the plant habitat, wild or cultivated. It also demonstrates that human management of the plant population has profound effects on the

  14. Human Management of a Wild Plant Modulates the Evolutionary Dynamics of a Gene Determining Recessive Resistance to Virus Infection.

    Directory of Open Access Journals (Sweden)

    Nils Poulicard

    2016-08-01

    Full Text Available This work analyses the genetic variation and evolutionary patterns of recessive resistance loci involved in matching-allele (MA host-pathogen interactions, focusing on the pvr2 resistance gene to potyviruses of the wild pepper Capsicum annuum glabriusculum (chiltepin. Chiltepin grows in a variety of wild habitats in Mexico, and its cultivation in home gardens started about 25 years ago. Potyvirus infection of Capsicum plants requires the physical interaction of the viral VPg with the pvr2 product, the translation initiation factor eIF4E1. Mutations impairing this interaction result in resistance, according to the MA model. The diversity of pvr2/eIF4E1 in wild and cultivated chiltepin populations from six biogeographical provinces in Mexico was analysed in 109 full-length coding sequences from 97 plants. Eleven alleles were found, and their interaction with potyvirus VPg in yeast-two-hybrid assays, plus infection assays of plants, identified six resistance alleles. Mapping resistance mutations on a pvr2/eIF4E1 model structure showed that most were around the cap-binding pocket and strongly altered its surface electrostatic potential, suggesting resistance-associated costs due to functional constraints. The pvr2/eIF4E1 phylogeny established that susceptibility was ancestral and resistance was derived. The spatial structure of pvr2/eIF4E1 diversity differed from that of neutral markers, but no evidence of selection for resistance was found in wild populations. In contrast, the resistance alleles were much more frequent, and positive selection stronger, in cultivated chiltepin populations, where diversification of pvr2/eIF4E1 was higher. This analysis of the genetic variation of a recessive resistance gene involved in MA host-pathogen interactions in populations of a wild plant show that evolutionary patterns differ according to the plant habitat, wild or cultivated. It also demonstrates that human management of the plant population has profound

  15. Complete genome sequence of hypervirulent and outbreak-associated Acinetobacter baumannii strain LAC-4: epidemiology, resistance genetic determinants and potential virulence factors

    Science.gov (United States)

    Ou, Hong-Yu; Kuang, Shan N.; He, Xinyi; Molgora, Brenda M.; Ewing, Peter J.; Deng, Zixin; Osby, Melanie; Chen, Wangxue; Xu, H. Howard

    2015-01-01

    Acinetobacter baumannii is an important human pathogen due to its multi-drug resistance. In this study, the genome of an ST10 outbreak A. baumannii isolate LAC-4 was completely sequenced to better understand its epidemiology, antibiotic resistance genetic determinants and potential virulence factors. Compared with 20 other complete genomes of A. baumannii, LAC-4 genome harbors at least 12 copies of five distinct insertion sequences. It contains 12 and 14 copies of two novel IS elements, ISAba25 and ISAba26, respectively. Additionally, three novel composite transposons were identified: Tn6250, Tn6251 and Tn6252, two of which contain resistance genes. The antibiotic resistance genetic determinants on the LAC-4 genome correlate well with observed antimicrobial susceptibility patterns. Moreover, twelve genomic islands (GI) were identified in LAC-4 genome. Among them, the 33.4-kb GI12 contains a large number of genes which constitute the K (capsule) locus. LAC-4 harbors several unique putative virulence factor loci. Furthermore, LAC-4 and all 19 other outbreak isolates were found to harbor a heme oxygenase gene (hemO)-containing gene cluster. The sequencing of the first complete genome of an ST10 A. baumannii clinical strain should accelerate our understanding of the epidemiology, mechanisms of resistance and virulence of A. baumannii. PMID:25728466

  16. World-wide and regional intercomparison for the determination of organochlorine compounds and petroleum hydrocarbons in sediment sample IAEA-357. Report no. 51

    International Nuclear Information System (INIS)

    Villeneuve, J.P.; Mee, L.D.

    1992-06-01

    This report describes the results of IAEA/UNEP intercomparison run 357 for the chemical analysis of organochlorine compounds and petroleum hydrocarbons in marine sediments. The Marine Environmental Studies Laboratory (MESL) of IAEA-MEL has conducted intercomparison exercises on trace organic compounds for over ten years as part of its contribution to IAEA's analytical quality control service and UNEP's regional seas programme and occasionally in association with the intergovernmental oceanographic Commission (of UNESCO) GIPME programme. Results of previous exercises have revealed serious problems for many regional laboratories to obtain comparable data. This, in turn, has raised serious concerns on the validity of region-wide or global marine pollution assessments. Even more worrisome was the apparent lack of improvement in data quality from exercise to exercise. As a consequence of the above situation, it was decided to seek increased support for quality assurance programmes. Staff of MESL, with funding from UNEP, the World bank and regional trust funds, embarked on a campaign to train analysts in modern measurement techniques, supply appropriate and reliable reference methods and materials and, where possible, to improve analytical instruments in member states laboratories. This work continues at present and recent training programmes have been conducted in the Wider Caribbean, East Africa, The Gulf and the Mediterranean

  17. Determinants of virulence and of resistance to ceftiofur, gentamicin, and spectinomycin in clinical Escherichia coli from broiler chickens in Québec, Canada.

    Science.gov (United States)

    Chalmers, Gabhan; Cormier, Ashley C; Nadeau, Marie; Côté, Geneviève; Reid-Smith, Richard J; Boerlin, Patrick

    2017-05-01

    Antimicrobials are frequently used for the prevention of avian colibacillosis, with gentamicin used for this purpose in Québec until 2003. Ceftiofur was also used similarly, but voluntarily withdrawn in 2005 due to increasing resistance. Spectinomycin-lincomycin was employed as a replacement, but ceftiofur use was partially reinstated in 2007 until its definitive ban by the poultry industry in 2014. Gentamicin resistance frequency increased during the past decade in clinical Escherichia coli isolates from broiler chickens in Québec, despite this antimicrobial no longer being used. Since this increase coincided with the use of spectinomycin-lincomycin, co-selection of gentamicin resistance through spectinomycin was suspected. Therefore, relationships between spectinomycin, gentamicin, and ceftiofur resistance determinants were investigated here. The distribution of 13 avian pathogenic E. coli virulence-associated genes and their association with spectinomycin resistance were also assessed. A sample of 586 E. coli isolates from chickens with colibacillosis in Québec between 2009 and 2013 was used. The major genes identified for resistance to ceftiofur, gentamicin, and spectinomycin were bla CMY , aac(3)-VI, and aadA, respectively. The aadA and aac(3)-VI genes were strongly associated and shown to be located on a modified class 1 integron. The aadA and bla CMY genes were negatively associated, but when present together, were generally located on the same plasmids. No statistical positive association was observed between aadA and virulence genes, and virulence genes were only rarely detected on plasmids encoding spectinomycin resistance. Thus, the use of spectinomycin-lincomycin may likely select for gentamicin but not ceftiofur resistance, nor for any of the virulence-associated genes investigated. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Glued versus stapled anastomosis of the colon: An experimental study to determine comparative resistance to intraluminal pressure

    Directory of Open Access Journals (Sweden)

    Jiri Paral

    2014-07-01

    Conclusion: Healing with absorbable synthetic glue was as good as with staples. Glued anastomoses resisted pressures that were statistically significantly higher than physiological intraluminal colon pressures but lower than stapled ones.

  19. Genome-wide discovery of novel M1T1 group A streptococcal determinants important for fitness and virulence during soft-tissue infection.

    Directory of Open Access Journals (Sweden)

    Yoann Le Breton

    2017-08-01

    Full Text Available The Group A Streptococcus remains a significant human pathogen causing a wide array of disease ranging from self-limiting to life-threatening invasive infections. Epithelium (skin or throat colonization with progression to the subepithelial tissues is the common step in all GAS infections. Here, we used transposon-sequencing (Tn-seq to define the GAS 5448 genetic requirements for in vivo fitness in subepithelial tissue. A near-saturation transposon library of the M1T1 GAS 5448 strain was injected subcutaneously into mice, producing suppurative inflammation at 24 h that progressed to prominent abscesses with tissue necrosis at 48 h. The library composition was monitored en masse by Tn-seq and ratios of mutant abundance comparing the output (12, 24 and 48 h versus input (T0 mutant pools were calculated for each gene. We identified a total of 273 subcutaneous fitness (scf genes with 147 genes (55 of unknown function critical for the M1T1 GAS 5448 fitness in vivo; and 126 genes (53 of unknown function potentially linked to in vivo fitness advantage. Selected scf genes were validated in competitive subcutaneous infection with parental 5448. Two uncharacterized genes, scfA and scfB, encoding putative membrane-associated proteins and conserved among Gram-positive pathogens, were further characterized. Defined scfAB mutants in GAS were outcompeted by wild type 5448 in vivo, attenuated for lesion formation in the soft tissue infection model and dissemination to the bloodstream. We hypothesize that scfAB play an integral role in enhancing adaptation and fitness of GAS during localized skin infection, and potentially in propagation to other deeper host environments.

  20. Crave, like, eat: determinants of food intake in a sample of children and adolescents with a wide range in body mass

    Directory of Open Access Journals (Sweden)

    Johannes Hofmann

    2016-09-01

    Full Text Available Obesity is heterogeneous condition with obese individuals displaying different eating patterns. Growing evidence suggests that there is a subgroup of obese adults that is marked by frequent and intense food cravings and addiction-like consumption of high-calorie foods. Little is known, however, about such a subgroup of obese individuals in childhood and adolescence. In the present study, a sample of children and adolescents with a wide range in body mass was investigated and trait food craving, liking for and intake of high- and low-calorie foods was measured. One-hundred and forty-two children and adolescents (51.4% female, n = 73; Mage = 13.7 years, SD = 2.25; MBMI-SDS = 1.26, SD = 1.50 completed the Food Cravings Questionnaire - Trait, then viewed pictures of high- and low-calorie foods and rated their liking for them, and subsequently consumed some of these foods in a bogus taste test. Contrary to expectations, higher body mass was associated with lower consumption of high-calorie foods. However, there was an interaction between body mass and trait food craving when predicting food consumption: in obese participants, higher trait food craving was associated with higher consumption of high-calorie foods and this association was not found in normal-weight participants. The relationship between trait food craving and high-calorie food consumption within obese individuals was mediated by higher liking for high-calorie foods (but not by liking for low-calorie foods. Thus, similar to adults, a subgroup of obese children and adolescents - characterized by high trait food craving - seems to exist, calling for specific targeted treatment strategies.

  1. Genome-wide discovery of novel M1T1 group A streptococcal determinants important for fitness and virulence during soft-tissue infection.

    Science.gov (United States)

    Le Breton, Yoann; Belew, Ashton T; Freiberg, Jeffrey A; Sundar, Ganesh S; Islam, Emrul; Lieberman, Joshua; Shirtliff, Mark E; Tettelin, Hervé; El-Sayed, Najib M; McIver, Kevin S

    2017-08-01

    The Group A Streptococcus remains a significant human pathogen causing a wide array of disease ranging from self-limiting to life-threatening invasive infections. Epithelium (skin or throat) colonization with progression to the subepithelial tissues is the common step in all GAS infections. Here, we used transposon-sequencing (Tn-seq) to define the GAS 5448 genetic requirements for in vivo fitness in subepithelial tissue. A near-saturation transposon library of the M1T1 GAS 5448 strain was injected subcutaneously into mice, producing suppurative inflammation at 24 h that progressed to prominent abscesses with tissue necrosis at 48 h. The library composition was monitored en masse by Tn-seq and ratios of mutant abundance comparing the output (12, 24 and 48 h) versus input (T0) mutant pools were calculated for each gene. We identified a total of 273 subcutaneous fitness (scf) genes with 147 genes (55 of unknown function) critical for the M1T1 GAS 5448 fitness in vivo; and 126 genes (53 of unknown function) potentially linked to in vivo fitness advantage. Selected scf genes were validated in competitive subcutaneous infection with parental 5448. Two uncharacterized genes, scfA and scfB, encoding putative membrane-associated proteins and conserved among Gram-positive pathogens, were further characterized. Defined scfAB mutants in GAS were outcompeted by wild type 5448 in vivo, attenuated for lesion formation in the soft tissue infection model and dissemination to the bloodstream. We hypothesize that scfAB play an integral role in enhancing adaptation and fitness of GAS during localized skin infection, and potentially in propagation to other deeper host environments.

  2. Characterization of the etiological structure and genotypically determined phenotypic resistance to carbapenems of infectious complications leading pathogens in critically ill patients

    Directory of Open Access Journals (Sweden)

    O. A. Nazarchuk

    2018-06-01

    Full Text Available The aim is to investigate the genotypically determined phenotypic resistance to carbapenems of gram-negative microorganisms isolated from patients with critical states. Material and methods. Microbiological etiology of infectious complications in critically ill patients (n = 726 was investigated. In total, during the years 2011–2016, 933 clinical strains of infectious complications pathogens from patients with severe burns (n = 435 and from patients treated in intensive care units (n = 291 were isolated and identified. The sensitivity of microorganisms clinical isolates to antibiotics was investigated by means of the standard microbiological methods. In gram-negative bacteria resistant to carbapenems, a molecular genetic study of mechanisms of resistance, determined by the presence of VIM genes, was carried out using the method of real-time polymerase chain reaction. Results. Studies have shown that gram-negative microorganisms (Acinetobacter spp. – 36.3 %, P. aeruginosa – 31.7 %, Enterobacter spp. – 13.5 %, Proteus spp. – 7.9 %, E. coli – 3.8 %; K. pneumoniae – 3.6 %, etc. account for a significant part of infectious complications pathogens structure in critically ill patients. A. baumannii strains (67 % have expressed phenotypic resistance to most antibiotics, in particular to carbapenems (up to 63.2 %. Poly-antibiotic resistance was also found in P. aeruginosa (72 %, and above one the 3rd part of strains of this pathogen was found to have phenotypic resistance to carbapenems. In-depth study of molecular genetic determinants of the resistance mechanism to β-lactam antibiotics among clinical strains of gram-negative bacteria there was proved VIM-induced resistance to carbapenems in A. baumannii, P. aeruginosa, P. mirabilis. Conclusions. Enterobacteriaceae and non-fermenting gram-negative microorganisms (P. aeruginosa, P. mirabilis, A. baumannii, which are the leading causative agents of infectious complications in patients with

  3. Detection of coliform bacteria, determination of phylogenetic typing and antibiotic resistance profile of Escherichia coli in qanats and springs of East-Azerbaijan province

    Directory of Open Access Journals (Sweden)

    N. Shabani Lokarani

    2017-05-01

    Full Text Available Escherichia coli as a fecal contamination and is considered as an index in water. The aim of this study was to determine the phenotypic and genotypic characteristics of E. coli and antibiotic resistance of the isolates collected from qanats and springs in East-Azerbaijan province. For this purpose, 118 samples were selected from above mentioned area and examined by MPN method. The positive coliform samples were identified by phenotypic and genotypic methods. Afterwards, to determine the genetic diversity of E. coli isolates, phylogenetic typing we conducted by means of multiplex PCR. To determine the antibiotic resistance profile, antibiotic discs of Nalidixic Acid, Co-trimoxazol, Amoxicillin, Gentamaicin Ciprofloxacin, Chloramphenicol, Imipenem, Cefotaxime and Ceftazidime antibiogram were used. Based on results, 48% of the samples were evaluated as positive for coliform including 40% for E. coli and 19% for Klebsiella. Amongst 23 isolates confirmed as E. coli by PCR. Phylogenetic typing revealed  that 44% of E. coli strains belonged to type D and B2 and 56% belonged to A and B1 phylotypes. Antimicrobial susceptibility pattern showed that 92% of E. coli isolates were resistant to Amoxicillin. All E. coli isolates were sensitive to Imipenem. It was concluded that presence of pathogenic E. coli with high rate of antibacterial resistance in waters source could be considered as a human health hazard.

  4. Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

    Science.gov (United States)

    Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

    1998-01-01

    Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected

  5. Prevalence of community-associated multi-resistant Staphylococcus ...

    African Journals Online (AJOL)

    Antimicrobial resistance has become a great public health problem worldwide and multi-drugvresistance Staphylococcus aureus has been widely reported