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Sample records for broad host range

  1. The oomycete broad-host-range pathogen Phytophthora capsici.

    Science.gov (United States)

    Lamour, Kurt H; Stam, Remco; Jupe, Julietta; Huitema, Edgar

    2012-05-01

    Phytophthora capsici is a highly dynamic and destructive pathogen of vegetables. It attacks all cucurbits, pepper, tomato and eggplant, and, more recently, snap and lima beans. The disease incidence and severity have increased significantly in recent decades and the molecular resources to study this pathogen are growing and now include a reference genome. At the population level, the epidemiology varies according to the geographical location, with populations in South America dominated by clonal reproduction, and populations in the USA and South Africa composed of many unique genotypes in which sexual reproduction is common. Just as the impact of crop loss as a result of P. capsici has increased in recent decades, there has been a similar increase in the development of new tools and resources to study this devastating pathogen. Phytophthora capsici presents an attractive model for understanding broad-host-range oomycetes, the impact of sexual recombination in field populations and the basic mechanisms of Phytophthora virulence. Kingdom Chromista; Phylum Oomycota; Class Oomycetes; Order Peronosporales; Family Peronosporaceae; Genus Phytophthora; Species capsici. Symptoms vary considerably according to the host, plant part infected and environmental conditions. For example, in dry areas (e.g. southwestern USA and southern France), infection on tomato and bell or chilli pepper is generally on the roots and crown, and the infected plants have a distinctive black/brown lesion visible at the soil line (Fig. 1). In areas in which rainfall is more common (e.g. eastern USA), all parts of the plant are infected, including the roots, crown, foliage and fruit (Fig. 1). Root infections cause damping off in seedlings, whereas, in older plants, it is common to see stunted growth, wilting and, eventually, death. For tomatoes, it is common to see significant adventitious root growth just above an infected tap root, and the stunted plants, although severely compromised, may not die

  2. Broad host range of streptococcal macrolide resistance plasmids.

    OpenAIRE

    Buu-Hoï, A; Bieth, G; Horaud, T

    1984-01-01

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

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

    DEFF Research Database (Denmark)

    Klümper, Uli

    . Plasmids are implicated in the rapid spread of antibiotic resistance and the emergence of multi-resistant pathogenic bacteria, making it crucial to be able to quantify, understand, and, ideally, control plasmid transfer in mixed microbial communities. The fate of plasmids in microbial communities...... for plasmids carrying antibiotic resistance genes is increasingly suspected to majorly contribute to the emergence of multi-resistant pathogens. More specifically, I examined what fraction of a soil microbial community is permissive to plasmids, identified the phylogenetic identity of this fraction and studied......Horizontal transfer of mobile genetic elements facilitates adaptive and evolutionary processes in bacteria. Among the known mobile genetic elements, plasmids can confer their hosts with accessory adaptive traits, such as antibiotic or heavy metal resistances, or additional metabolic pathways...

  4. New Hepatitis B Virus of Cranes That Has an Unexpected Broad Host Range

    Science.gov (United States)

    Prassolov, Alexej; Hohenberg, Heinz; Kalinina, Tatyana; Schneider, Carola; Cova, Lucyna; Krone, Oliver; Frölich, Kai; Will, Hans; Sirma, Hüseyin

    2003-01-01

    All hepadnaviruses known so far have a very limited host range, restricted to their natural hosts and a few closely related species. This is thought to be due mainly to sequence divergence in the large envelope protein and species-specific differences in host components essential for virus propagation. Here we report an infection of cranes with a novel hepadnavirus, designated CHBV, that has an unexpectedly broad host range and is only distantly evolutionarily related to avihepadnaviruses of related hosts. Direct DNA sequencing of amplified CHBV DNA as well a sequencing of cloned viral genomes revealed that CHBV is most closely related to, although distinct from, Ross' goose hepatitis B virus (RGHBV) and slightly less closely related to duck hepatitis B virus (DHBV). Phylogenetically, cranes are very distant from geese and ducks and are most closely related to herons and storks. Naturally occurring hepadnaviruses in the last two species are highly divergent in sequence from RGHBV and DHBV and do not infect ducks or do so only marginally. In contrast, CHBV from crane sera and recombinant CHBV produced from LMH cells infected primary duck hepatocytes almost as efficiently as DHBV did. This is the first report of a rather broad host range of an avihepadnavirus. Our data imply either usage of similar or identical entry pathways and receptors by DHBV and CHBV, unusual host and virus adaptation mechanisms, or divergent evolution of the host genomes and cellular components required for virus propagation. PMID:12525630

  5. Broad host range plasmids can invade an unexpectedly diverse fraction of a soil bacterial community

    DEFF Research Database (Denmark)

    Klümper, Uli; Riber, Leise; Dechesne, Arnaud

    2014-01-01

    range of IncP- and IncPromA-type broad host range plasmids from three proteobacterial donors to a soil bacterial community. We identified transfer to many different recipients belonging to 11 different bacterial phyla. The prevalence of transconjugants belonging to diverse Gram-positive Firmicutes...... and Actinobacteria suggests that inter-Gram plasmid transfer of IncP-1 and IncPromA-type plasmids is a frequent phenomenon. While the plasmid receiving fractions of the community were both plasmid- and donor- dependent, we identified a core super-permissive fraction that could take up different plasmids from diverse...... donor strains. This fraction, comprising 80% of the identified transconjugants, thus has the potential to dominate IncP- and IncPromA-type plasmid transfer in soil. Our results demonstrate that these broad host range plasmids have a hitherto unrecognized potential to transfer readily to very diverse...

  6. Broad-Host-Range IncP-1 plasmids and their resistance potential

    Directory of Open Access Journals (Sweden)

    Magdalena ePopowska

    2013-03-01

    Full Text Available The plasmids of the incompatibility group IncP-1, also called IncP, as extrachromosomal genetic elements can transfer and replicate virtually in all Gram-negative bacteria. They are composed of backbone genes that encode a variety of essential functions and accessory genes that have implications for human health and environmental bioremediation. Broad-host-range IncP plasmids are known to spread genes between distinct phylogenetic groups of bacteria. These genes often code for resistances to a broad spectrum of antibiotics, heavy metals and quaternary ammonium compounds used as disinfectants. The backbone of these plasmids carries modules that enable them to effectively replicate, move to a new host via conjugative transfer and to be stably maintained in bacterial cells. The adaptive, resistance and virulence genes are mainly located on mobile genetic elements integrated between the functional plasmid backbone modules. Environmental studies have demonstrated the wide distribution of IncP-like replicons in manure, soils and wastewater treatment plants. They also are present in strains of pathogenic or opportunistic bacteria, which can be a cause for concern, because they may encode multiresistance. Their broad distribution suggests that IncP plasmids play a crucial role in bacterial adaptation by utilizing horizontal gene transfer. This review summarizes the variety of genetic information and physiological functions carried by IncP plasmids, which can contribute to the spread of antibiotic and heavy metal resistance while also mediating the process of bioremediation of pollutants. Due to the location of the resistance genes on plasmids with a broad host range and the presence of transposons carrying these genes it seems that the spread of these genes would be possible and quite hazardous in infection control. Future studies are required to determine the level of risk of the spread of resistance genes located on these plasmids.

  7. Development of a broad-host-range sacB-based vector for unmarked allelic exchange

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    Marx Christopher J

    2008-02-01

    Full Text Available Abstract Background Although genome sequences are available for an ever-increasing number of bacterial species, the availability of facile genetic tools for physiological analysis have generally lagged substantially behind traditional genetic models. Results Here I describe the development of an improved, broad-host-range "in-out" allelic exchange vector, pCM433, which permits the generation of clean, marker-free genetic manipulations. Wild-type and mutant alleles were reciprocally exchanged at three loci in Methylobacterium extorquens AM1 in order to demonstrate the utility of pCM433. Conclusion The broad-host-range vector for marker-free allelic exchange described here, pCM433, has the advantages of a high copy, general Escherichia coli replicon for easy cloning, an IncP oriT enabling conjugal transfer, an extensive set of restriction sites in its polylinker, three antibiotic markers, and sacB (encoding levansucrase for negative selection upon sucrose plates. These traits should permit pCM433 to be broadly applied across many bacterial taxa for marker-free allelic exchange, which is particularly important if multiple manipulations or more subtle genetic manipulations such as point mutations are desired.

  8. Development of a gene silencing DNA vector derived from a broad host range geminivirus

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    Hancock Leandria C

    2009-07-01

    Full Text Available Abstract Background Gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. The use of viral induced gene silencing (VIGS offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. However, many VIGS vectors are derived from Gemini viruses that have limited host ranges. We present a new, unipartite vector that is derived from a curtovirus that has a broad host range and will be amenable to use in many non-model systems. Results The construction of a gene silencing vector derived from the geminivirus Beet curly top virus (BCTV, named pWSRi, is reported. Two versions of the vector have been developed to allow application by biolistic techniques or by agro-infiltration. We demonstrate its ability to silence nuclear genes including ribulose bisphosphate carboxylase small subunit (rbcS, transketolase, the sulfur allele of magnesium chelatase (ChlI, and two homeotic transcription factors in spinach or tomato by generating gene-specific knock-down phenotypes. Onset of phenotypes occurred 3 to 12 weeks post-inoculation, depending on the target gene, in organs that developed after the application. The vector lacks movement genes and we found no evidence for significant spread from the site of inoculation. However, viral amplification in inoculated tissue was detected and is necessary for systemic silencing, suggesting that signals generated from active viral replicons are efficiently transported within the plant. Conclusion The unique properties of the pWSRi vector, the ability to silence genes in meristem tissue, the separation of virus and silencing phenotypes, and the broad natural host range of BCTV, suggest that it will have wide utility.

  9. Modular broad-host-range expression vectors for single-protein and protein complex purification.

    Science.gov (United States)

    Fodor, Barna D; Kovács, Akos T; Csáki, Róbert; Hunyadi-Gulyás, Eva; Klement, Eva; Maróti, Gergely; Mészáros, Lívia S; Medzihradszky, Katalin F; Rákhely, Gábor; Kovács, Kornél L

    2004-02-01

    A set of modular broad-host-range expression vectors with various affinity tags (six-His-tag, FLAG-tag, Strep-tag II, T7-tag) was created. The complete nucleotide sequences of the vectors are known, and these small vectors can be mobilized by conjugation. They are useful in the purification of proteins and protein complexes from gram-negative bacterial species. The plasmids were easily customized for Thiocapsa roseopersicina, Rhodobacter capsulatus, and Methylococcus capsulatus by inserting an appropriate promoter. These examples demonstrate the versatility and flexibility of the vectors. The constructs harbor the T7 promoter for easy overproduction of the desired protein in an appropriate Escherichia coli host. The vectors were useful in purifying different proteins from T. roseopersicina. The FLAG-tag-Strep-tag II combination was utilized for isolation of the HynL-HypC2 protein complex involved in hydrogenase maturation. These tools should be useful for protein purification and for studying protein-protein interactions in a range of bacterial species.

  10. Construction and characterization of regulated L-arabinose-inducible broad host range expression vectors in Xanthomonas.

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    Sukchawalit, R; Vattanaviboon, P; Sallabhan, R; Mongkolsuk, S

    1999-12-15

    Several versions of broad host range (BHR), L-arabinose-inducible expression vectors were constructed. These expression vectors were based on a high copy number BHR pBBR1MCS-4 replicon that could replicate in both enteric and non-enteric Gram-negative bacteria. Two versions of expression cassettes containing multiple cloning sites either with or without a ribosome binding site were placed under transcriptional control of the Escherichia coli BAD promoter and araC gene. Three versions of vectors containing ampicillin or kanamycin or tetracycline resistance genes as selectable markers were constructed. In all six new L-arabinose-inducible BHR expression vectors containing many unique cloning sites, selectable markers were made to facilitate cloning and expression of genes in various Gram-negative bacteria. A Tn9 chloramphenicol acetyl transferase (cat) gene was cloned into an expression vector, resulting in pBBad18Acat that was used to establish optimal expression conditions (addition of 0.02% L-arabinose to mid-exponential phase cells for at least 1 h) in a Xanthomonas campestris pv. phaseoli. Comparison of the Cat enzyme activities between uninduced and a 180-min L-arabinose-induced culture showed a greater than 150-fold increased Cat specific activity. In addition, L-arabinose induction of exponential phase cells harboring pBBad18Acat gave a higher amount of Cat than similarly treated stationary phase cells. The usefulness of the expression vector was also demonstrated in both enteric and non-enteric Gram-negative bacteria.

  11. Characterization of novel virulent broad-host-range phages of Xylella fastidiosa and Xanthomonas.

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    Ahern, Stephen J; Das, Mayukh; Bhowmick, Tushar Suvra; Young, Ry; Gonzalez, Carlos F

    2014-01-01

    The xylem-limited bacterium Xylella fastidiosa is the causal agent of several plant diseases, most notably Pierce's disease of grape and citrus variegated chlorosis. We report the isolation and characterization of the first virulent phages for X. fastidiosa, siphophages Sano and Salvo and podophages Prado and Paz, with a host range that includes Xanthomonas spp. Phages propagated on homologous hosts had observed adsorption rate constants of ~4 × 10(-12) ml cell(-1) min(-1) for X. fastidiosa strain Temecula 1 and ~5 × 10(-10) to 7 × 10(-10) ml cell(-1) min(-1) for Xanthomonas strain EC-12. Sano and Salvo exhibit >80% nucleotide identity to each other in aligned regions and are syntenic to phage BcepNazgul. We propose that phage BcepNazgul is the founding member of a novel phage type, to which Sano and Salvo belong. The lysis genes of the Nazgul-like phage type include a gene that encodes an outer membrane lipoprotein endolysin and also spanin gene families that provide insight into the evolution of the lysis pathway for phages of Gram-negative hosts. Prado and Paz, although exhibiting no significant DNA homology to each other, are new members of the phiKMV-like phage type, based on the position of the single-subunit RNA polymerase gene. The four phages are type IV pilus dependent for infection of both X. fastidiosa and Xanthomonas. The phages may be useful as agents for an effective and environmentally responsible strategy for the control of diseases caused by X. fastidiosa.

  12. Characterization of Novel Virulent Broad-Host-Range Phages of Xylella fastidiosa and Xanthomonas

    Science.gov (United States)

    Ahern, Stephen J.; Das, Mayukh; Bhowmick, Tushar Suvra; Young, Ry

    2014-01-01

    The xylem-limited bacterium Xylella fastidiosa is the causal agent of several plant diseases, most notably Pierce's disease of grape and citrus variegated chlorosis. We report the isolation and characterization of the first virulent phages for X. fastidiosa, siphophages Sano and Salvo and podophages Prado and Paz, with a host range that includes Xanthomonas spp. Phages propagated on homologous hosts had observed adsorption rate constants of ∼4 × 10−12 ml cell−1 min−1 for X. fastidiosa strain Temecula 1 and ∼5 × 10−10 to 7 × 10−10 ml cell−1 min−1 for Xanthomonas strain EC-12. Sano and Salvo exhibit >80% nucleotide identity to each other in aligned regions and are syntenic to phage BcepNazgul. We propose that phage BcepNazgul is the founding member of a novel phage type, to which Sano and Salvo belong. The lysis genes of the Nazgul-like phage type include a gene that encodes an outer membrane lipoprotein endolysin and also spanin gene families that provide insight into the evolution of the lysis pathway for phages of Gram-negative hosts. Prado and Paz, although exhibiting no significant DNA homology to each other, are new members of the phiKMV-like phage type, based on the position of the single-subunit RNA polymerase gene. The four phages are type IV pilus dependent for infection of both X. fastidiosa and Xanthomonas. The phages may be useful as agents for an effective and environmentally responsible strategy for the control of diseases caused by X. fastidiosa. PMID:24214944

  13. Characterization of JG024, a pseudomonas aeruginosa PB1-like broad host range phage under simulated infection conditions

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    Rohde Manfred

    2010-11-01

    Full Text Available Abstract Background Pseudomonas aeruginosa causes lung infections in patients suffering from the genetic disorder Cystic Fibrosis (CF. Once a chronic lung infection is established, P. aeruginosa cannot be eradicated by antibiotic treatment. Phage therapy is an alternative to treat these chronic P. aeruginosa infections. However, little is known about the factors which influence phage infection of P. aeruginosa under infection conditions and suitable broad host range phages. Results We isolated and characterized a phage, named JG024, which infects a broad range of clinical and environmental P. aeruginosa strains. Sequencing of the phage genome revealed that the phage JG024 is highly related to the ubiquitous and conserved PB1-like phages. The receptor of phage JG024 was determined as lipopolysaccharide. We used an artificial sputum medium to study phage infection under conditions similar to a chronic lung infection. Alginate production was identified as a factor reducing phage infectivity. Conclusions Phage JG024 is a suitable broad host range phage which could be used in phage therapy. Phage infection experiments under simulated chronic lung infection conditions showed that alginate production reduces phage infection efficiency.

  14. Isolation of broad-host-range replicons from marine sediment bacteria.

    Science.gov (United States)

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

    1998-08-01

    Naturally occurring plasmids isolated from heterotrophic bacterial isolates originating from coastal California marine sediments were characterized by analyzing their incompatibility and replication properties. Previously, we reported on the lack of DNA homology between plasmids from the culturable bacterial population of marine sediments and the replicon probes specific for a number of well-characterized incompatibility and replication groups (P. A. Sobecky, T. J. Mincer, M. C. Chang, and D. R. Helinski, Appl. Environ. Microbiol. 63:888-895, 1997). In the present study we isolated 1.8- to 2.3-kb fragments that contain functional replication origins from one relatively large (30-kb) and three small (marine isolates. 16S rRNA sequence analyses indicated that the four plasmid-bearing marine isolates belonged to the alpha and gamma subclasses of the class Proteobacteria. Three of the marine sediment isolates are related to the gamma-3 subclass organisms Vibrio splendidus and Vibrio fischeri, while the fourth isolate may be related to Roseobacter litoralis. Sequence analysis of the plasmid replication regions revealed the presence of features common to replication origins of well-characterized plasmids from clinical bacterial isolates, suggesting that there may be similar mechanisms for plasmid replication initiation in the indigenous plasmids of gram-negative marine sediment bacteria. In addition to replication in Escherichia coli DH5alpha and C2110, the host ranges of the plasmid replicons, designated repSD41, repSD121, repSD164, and repSD172, extended to marine species belonging to the genera Achromobacter, Pseudomonas, Serratia, and Vibrio. While sequence analysis of repSD41 and repSD121 revealed considerable stretches of homology between the two fragments, these regions do not display incompatibility properties against each other. The replication origin repSD41 was detected in 5% of the culturable plasmid-bearing marine sediment bacterial isolates, whereas the

  15. Emerging trends in molecular interactions between plants and the broad host range fungal pathogens Botrytis cinerea and Sclerotinia sclerotiorum

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    Malick eMbengue

    2016-03-01

    Full Text Available Fungal plant pathogens are major threats to food security worldwide. Sclerotinia sclerotiorum and Botrytis cinerea are closely related Ascomycete plant pathogens causing mold diseases on hundreds of plant species. There is no genetic source of complete plant resistance to these broad host range pathogens known to date. Instead, natural plant populations show a continuum of resistance levels controlled by multiple genes, a phenotype designated as quantitative disease resistance. Little is known about the molecular mechanisms controlling the interaction between plants and S. sclerotiorum and B. cinerea but significant advances were made on this topic in the last years. This minireview highlights a selection of nine themes that emerged in recent research reports on the molecular bases of plant-S. sclerotiorum and plant-B. cinerea interactions. On the fungal side, this includes progress on understanding the role of oxalic acid, on the study of fungal small secreted proteins. Next, we discuss the exchanges of small RNA between organisms and the control of cell death in plant and fungi during pathogenic interactions. Finally on the plant side, we highlight defense priming by mechanical signals, the characterization of plant Receptor-like proteins and the hormone abscisic acid in the response to B. cinerea and S. sclerotiorum , the role of plant general transcription machinery and plant small bioactive peptides. These represent nine trends we selected as remarkable in our understanding of fungal molecules causing disease and plant mechanisms associated with disease resistance to two devastating broad host range fungi.

  16. Secretome analysis reveals effector candidates associated with broad host range necrotrophy in the fungal plant pathogen Sclerotinia sclerotiorum.

    Science.gov (United States)

    Guyon, Koanna; Balagué, Claudine; Roby, Dominique; Raffaele, Sylvain

    2014-05-04

    The white mold fungus Sclerotinia sclerotiorum is a devastating necrotrophic plant pathogen with a remarkably broad host range. The interaction of necrotrophs with their hosts is more complex than initially thought, and still poorly understood. We combined bioinformatics approaches to determine the repertoire of S. sclerotiorum effector candidates and conducted detailed sequence and expression analyses on selected candidates. We identified 486 S. sclerotiorum secreted protein genes expressed in planta, many of which have no predicted enzymatic activity and may be involved in the interaction between the fungus and its hosts. We focused on those showing (i) protein domains and motifs found in known fungal effectors, (ii) signatures of positive selection, (iii) recent gene duplication, or (iv) being S. sclerotiorum-specific. We identified 78 effector candidates based on these properties. We analyzed the expression pattern of 16 representative effector candidate genes on four host plants and revealed diverse expression patterns. These results reveal diverse predicted functions and expression patterns in the repertoire of S. sclerotiorum effector candidates. They will facilitate the functional analysis of fungal pathogenicity determinants and should prove useful in the search for plant quantitative disease resistance components active against the white mold.

  17. In vivo excision, cloning, and broad-host-range transfer of large bacterial DNA segments using VEX-Capture.

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    Wilson, James W; Nickerson, Cheryl A

    2007-01-01

    The performance of many bacterial genetic experiments would benefit from a convenient method to clone large sets of genes (20-100+ kb) and transfer these genes to a wide range of other bacterial recipients. The VEX-Capture technique allows such large genomic segments to be cloned in vivo onto a broad-host-range IncP plasmid that is able to self-transfer to a wide variety of Gram-negative bacteria. The advantages of VEX-Capture are its efficiency, specificity, and use of common molecular biological techniques that do not require non-standard equipment and are easily applicable to many types of bacterial species. Here, we describe the VEX-Capture experimental protocol using Salmonella typhimurium as the source of the target DNA segment.

  18. Broad-Host-Range Expression Reveals Native and Host Regulatory Elements That Influence Heterologous Antibiotic Production in Gram-Negative Bacteria

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    Jia Jia Zhang

    2017-09-01

    Full Text Available Heterologous expression has become a powerful tool for studying microbial biosynthetic gene clusters (BGCs. Here, we extend the transformation-associated recombination cloning and heterologous expression platform for microbial BGCs to include Gram-negative proteobacterial expression hosts. Using a broad-host-range expression platform, we test the implicit assumption that biosynthetic pathways are more successfully expressed in more closely related heterologous hosts. Cloning and expression of the violacein BGC from Pseudoalteromonas luteoviolacea 2ta16 revealed robust production in two proteobacterial hosts, Pseudomonas putida KT2440 and Agrobacterium tumefaciens LBA4404, but very little production of the antibiotic in various laboratory strains of Escherichia coli, despite their closer phylogenetic relationship. We identified a nonclustered LuxR-type quorum-sensing receptor from P. luteoviolacea 2ta16, PviR, that increases pathway transcription and violacein production in E. coli by ∼60-fold independently of acyl-homoserine lactone autoinducers. Although E. coli harbors the most similar homolog of PviR identified from all of the hosts tested, overexpression of various E. coli transcription factors did not result in a statistically significant increase in violacein production, while overexpression of two A. tumefaciens PviR homologs significantly increased production. Thus, this work not only introduces a new genetic platform for the heterologous expression of microbial BGCs, it also challenges the assumption that host phylogeny is an accurate predictor of host compatibility.

  19. The broad-host-range plasmid pSFA231 isolated from petroleum-contaminated sediment represents a new member of the PromA plasmid family

    National Research Council Canada - National Science Library

    Li, Xiaobin; Top, Eva M; Wang, Yafei; Brown, Celeste J; Yao, Fei; Yang, Shan; Jiang, Yong; Li, Hui

    2015-01-01

    A self-transmissible broad-host-range (BHR) plasmid pSFA231 was isolated from petroleum-contaminated sediment in Shen-fu wastewater irrigation zone, China, using the triparental mating exogenous plasmid capture method...

  20. The broad-host-range plasmid pSFA231 isolated from petroleum-contaminated sediment represents a new member of the PromA plasmid family

    National Research Council Canada - National Science Library

    Li, Xiaobin; Top, Eva M; Wang, Yafei; Brown, Celeste J; Yao, Fei; Yang, Shan; Jiang, Yong; Li, Hui

    2014-01-01

    A self-transmissible broad-host-range (BHR) plasmid pSFA231 was isolated from petroleum-contaminated sediment in Shen-fu wastewater irrigation zone, China, using the triparental mating exogenous plasmid capture method...

  1. [Isolation and characterization of petroleum catabolic broad-host-range plasmids from Shen-Fu wastewater irrigation zone].

    Science.gov (United States)

    Wang, Ya-Fei; Wang, Ya-Fei; Li, Hui; Li, Xiao-Bin

    2013-11-01

    Based on triparental mating, we isolated a total of eight broad host range (BHR) petroleum hydrocarbon catabolic plasmids from the soils, sediments, and wastewater samples in the Shen-Fu irrigation zone. The antibiotic resistance of the plasmids was tested, and then, the plasmids were transferred to Escherichia coli EC100. The plasmids carrying no antibiotic resistance were tagged by miniTn5 transposon consisting of antibiotic resistant genes. The PCR-based incompatibility test revealed that the pS3-2C and pS4-6G belonged to Inc P group, the pS3-2G, pW22-3G, and pA15-7G belonged to Inc N group, the pS7-2G was identified as Inc W plasmid, and the pA23-1G and pA10-1C were placed into Inc Q group. By adopting the reported PCR amplification methods of petroleum hydrocarbon-degrading catabolic genes, the petroleum-degrading capability of these BHR plasmids were preliminarily analyzed. The plasmids pS3-2G, pS7-2G, pA23-1G, pW22-3G, and pA10-1C carried aromatic ring- hydroxylating dioxygenase gene phdA and toluene monooxygenase gene touA; the plasmid pA15-7G carried touA and toluene dioxygenase gene tod; the plasmid pS3-2C carried ben, phdA, and tod; whereas the pS4-6G only carried ben. The host range test showed that all the isolated plasmids except pS3-2C could be transferred and maintained stably in the representative strains Agrobacterium tumefaciens C58, Cupriavidus necator JMP228, and E. coli EC100 of the alpha-, beta-, and gamma-Proteobacteria, respectively.

  2. Site-specific deletions of chromosomally located DNA segments with the multimer resolution system of broad-host-range plasmid RP4

    DEFF Research Database (Denmark)

    Sternberg, Claus; Eberl, Leo; Sanchezromero, Juan M.

    1995-01-01

    The multimer resolution system (mrs) of the broad-host-range plasmid RP4 has been exploited to develop a general method that permits the precise excision of chromosomal segments in a variety of gram-negative bacteria. The procedure is based on the site-specific recombination between two directly...... transposons inserted in the chromosome of Pseudomonas putida, This strategy permits the stable inheritance of heterologous DNA segments virtually devoid of the sequences used initially to select their insertion....

  3. Complete nucleotide sequence and analysis of two conjugative broad host range plasmids from a marine microbial biofilm.

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    Peter Norberg

    Full Text Available The complete nucleotide sequence of plasmids pMCBF1 and pMCBF6 was determined and analyzed. pMCBF1 and pMCBF6 form a novel clade within the IncP-1 plasmid family designated IncP-1 ς. The plasmids were exogenously isolated earlier from a marine biofilm. pMCBF1 (62 689 base pairs; bp and pMCBF6 (66 729 bp have identical backbones, but differ in their mercury resistance transposons. pMCBF1 carries Tn5053 and pMCBF6 carries Tn5058. Both are flanked by 5 bp direct repeats, typical of replicative transposition. Both insertions are in the vicinity of a resolvase gene in the backbone, supporting the idea that both transposons are "res-site hunters" that preferably insert close to and use external resolvase functions. The similarity of the backbones indicates recent insertion of the two transposons and the ongoing dynamics of plasmid evolution in marine biofilms. Both plasmids also carry the insertion sequence ISPst1, albeit without flanking repeats. ISPs1is located in an unusual site within the control region of the plasmid. In contrast to most known IncP-1 plasmids the pMCBF1/pMCBF6 backbone has no insert between the replication initiation gene (trfA and the vegetative replication origin (oriV. One pMCBF1/pMCBF6 block of about 2.5 kilo bases (kb has no similarity with known sequences in the databases. Furthermore, insertion of three genes with similarity to the multidrug efflux pump operon mexEF and a gene from the NodT family of the tripartite multi-drug resistance-nodulation-division (RND system in Pseudomonas aeruginosa was found. They do not seem to confer antibiotic resistance to the hosts of pMCBF1/pMCBF6, but the presence of RND on promiscuous plasmids may have serious implications for the spread of antibiotic multi-resistance.

  4. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  5. Efficient delivery of large DNA from Escherichia coli to Synechococcus elongatus PCC7942 by broad-host-range conjugal plasmid pUB307.

    Science.gov (United States)

    Itaya, Mitsuhiro; Kusakabe, Hiroko; Sato, Mitsuru; Tomita, Masaru; Sato, Rintaro

    2018-02-06

    Synechococcus elongatus PCC7942, a cyanobacterium that uses light and carbon dioxide to grow, has a high ability to incorporate DNA by transformation. To assess the effective delivery of large DNA in plasmid form, we cloned the endogenous plasmid pANL (46.4 kbp) into a BAC vector of Escherichia coli. The plasmid p38ANL (54.3 kbp) replaced the native plasmid. To assess the delivery of larger DNA into PCC7942, p38ANL was fused to the broad-host-range conjugal transfer plasmid pUB307IP (53.5 kbp). The resulting plasmid pUB307IP501 (107.9 kbp) was transmitted from E. coli to PCC7942 by simple mixing of donor and recipient cultures. PCC7942 transcipients possessed only pUB307IP501, replacing the preexisting pANL. In contrast, the pUB307IP501 plasmid was unable to transform PCC7942, indicating that natural transformation of DNA may be restricted by size limitations. The ability to deliver large DNA by conjugation may lead to genetic engineering in PCC7942. © The Authors 2018. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  6. The broad-host-range plasmid pSFA231 isolated from petroleum-contaminated sediment represents a new member of the PromA plasmid family

    Directory of Open Access Journals (Sweden)

    Xiaobin eLi

    2015-01-01

    Full Text Available A self-transmissible broad-host-range (BHR plasmid pSFA231 was isolated from petroleum-contaminated sediment in Shen-fu wastewater irrigation zone, China, using the triparental mating exogenous plasmid capture method. Based on its complete sequence the plasmid has a size of 41.5 kb and codes for 50 putative open reading frames (orfs, 28 of which represent genes involved in replication, partitioning and transfer functions of the plasmid. Phylogenetic analysis grouped pSFA231 into the newly defined PromA plasmid family, which currently includes five members. Further comparative genomic analysis shows that pSFA231 shares the common backbone regions with the other PromA plasmids, i.e., genes involved in replication, maintenance and control, and conjugative transfer. Nevertheless, phylogenetic divergence was found in specific gene products. We propose to divide the PromA group into two subgroups, PromA-α (pMRAD02, pSB102 and PromA-β (pMOL98, pIPO2T, pSFA231, pTer331, based on the splits network analysis of the RepA protein. Interestingly, a cluster of hypothetical orfs located between parA and traA of pSFA231 shows high similarity with the corresponding regions on pMOL98, pIPO2T and pTer331, suggesting these hypothetical orfs may represent ‘‘essential’’ plasmid backbone genes for the PromA-β subgroup. Alternatively, they may also be accessory genes that were first acquired and then stayed as the plasmid diverged. Our study increases the available collection of complete genome sequences of BHR plasmids, and since pSFA231 is the only characterized PromA plasmid from China, our findings also enhance our understanding of the genetic diversity of this plasmid group in different parts of the world.

  7. The broad-host-range plasmid pSFA231 isolated from petroleum-contaminated sediment represents a new member of the PromA plasmid family.

    Science.gov (United States)

    Li, Xiaobin; Top, Eva M; Wang, Yafei; Brown, Celeste J; Yao, Fei; Yang, Shan; Jiang, Yong; Li, Hui

    2014-01-01

    A self-transmissible broad-host-range (BHR) plasmid pSFA231 was isolated from petroleum-contaminated sediment in Shen-fu wastewater irrigation zone, China, using the triparental mating exogenous plasmid capture method. Based on its complete sequence the plasmid has a size of 41.5 kb and codes for 50 putative open reading frames (orfs), 29 of which represent genes involved in replication, partitioning and transfer functions of the plasmid. Phylogenetic analysis grouped pSFA231 into the newly defined PromA plasmid family, which currently includes five members. Further comparative genomic analysis shows that pSFA231 shares the common backbone regions with the other PromA plasmids, i.e., genes involved in replication, maintenance and control, and conjugative transfer. Nevertheless, phylogenetic divergence was found in specific gene products. We propose to divide the PromA group into two subgroups, PromA-α (pMRAD02, pSB102) and PromA-β (pMOL98, pIPO2T, pSFA231, pTer331), based on the splits network analysis of the RepA protein. Interestingly, a cluster of hypothetical orfs located between parA and traA of pSFA231 shows high similarity with the corresponding regions on pMOL98, pIPO2T, and pTer331, suggesting these hypothetical orfs may represent "essential" plasmid backbone genes for the PromA-β subgroup. Alternatively, they may also be accessory genes that were first acquired and then stayed as the plasmid diverged. Our study increases the available collection of complete genome sequences of BHR plasmids, and since pSFA231 is the only characterized PromA plasmid from China, our findings also enhance our understanding of the genetic diversity of this plasmid group in different parts of the world.

  8. The complete genome sequence of the phytopathogenic fungus Sclerotinia sclerotiorum reveals insights into the genome architecture of broad host range pathogens

    NARCIS (Netherlands)

    Derbyshire, Mark; Denton-Giles, Matthew; Hegedus, Dwayne; Seifbarghi, Shirin; Rollins, Jeffrey; Kan, van Jan; Seidl, Michael F.; Faino, Luigi; Mbengue, Malick; Navaud, Olivier

    2017-01-01

    Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a "two-speed" genome. So

  9. The Complete Genome Sequence of the Phytopathogenic Fungus Sclerotinia sclerotiorum Reveals Insights into the Genome Architecture of Broad Host Range Pathogens

    Science.gov (United States)

    Denton-Giles, Matthew; Hegedus, Dwayne; Seifbarghy, Shirin; Rollins, Jeffrey; van Kan, Jan; Seidl, Michael F.; Faino, Luigi; Mbengue, Malick; Navaud, Olivier; Raffaele, Sylvain; Hammond-Kosack, Kim; Heard, Stephanie; Oliver, Richard

    2017-01-01

    Sclerotinia sclerotiorum is a phytopathogenic fungus with over 400 hosts including numerous economically important cultivated species. This contrasts many economically destructive pathogens that only exhibit a single or very few hosts. Many plant pathogens exhibit a “two-speed” genome. So described because their genomes contain alternating gene rich, repeat sparse and gene poor, repeat-rich regions. In fungi, the repeat-rich regions may be subjected to a process termed repeat-induced point mutation (RIP). Both repeat activity and RIP are thought to play a significant role in evolution of secreted virulence proteins, termed effectors. We present a complete genome sequence of S. sclerotiorum generated using Single Molecule Real-Time Sequencing technology with highly accurate annotations produced using an extensive RNA sequencing data set. We identified 70 effector candidates and have highlighted their in planta expression profiles. Furthermore, we characterized the genome architecture of S. sclerotiorum in comparison to plant pathogens that exhibit “two-speed” genomes. We show that there is a significant association between positions of secreted proteins and regions with a high RIP index in S. sclerotiorum but we did not detect a correlation between secreted protein proportion and GC content. Neither did we detect a negative correlation between CDS content and secreted protein proportion across the S. sclerotiorum genome. We conclude that S. sclerotiorum exhibits subtle signatures of enhanced mutation of secreted proteins in specific genomic compartments as a result of transposition and RIP activity. However, these signatures are not observable at the whole-genome scale. PMID:28204478

  10. Multi-locus genotypes of Enterocytozoon bieneusi in captive Asiatic black bears in southwestern China: High genetic diversity, broad host range, and zoonotic potential

    Science.gov (United States)

    Cao, Xuefeng; Song, Yuan; Wang, Wuyou; Huang, Xiangming; Liu, Xuehan; Hu, Yanchun; Fu, Hualin; He, Min; Wang, Ya; Zhang, Yue; Wu, Kongju; Peng, Guangneng

    2017-01-01

    Enterocytozoon bieneusi is an obligate eukaryotic intracellular parasite that infects a wide variety of vertebrate and invertebrate hosts. Although considerable research has been conducted on this organism, relatively little information is available on the occurrence of E. bieneusi in captive Asiatic black bears. The present study was performed to determine the prevalence, genetic diversity, and zoonotic potential of E. bieneusi in captive Asiatic black bears in zoos in southwestern China. Fecal specimens from Asiatic black bears in four zoos, located in four different cities, were collected and analyzed for the prevalence of E. bieneusi. The average prevalence of E. bieneusi was 27.4% (29/106), with the highest prevalence in Guiyang Zoo (36.4%, 16/44). Altogether, five genotypes of E. bieneusi were identified among the 29 E. bieneusi-positive samples, including three known genotypes (CHB1, SC02, and horse2) and two novel genotypes named ABB1 and ABB2. Multi-locus sequence typing using three microsatellites (MS1, MS3, and MS7) and one minisatellite (MS4) revealed V, III, V, and IV genotypes at these four loci, respectively. Phylogenetic analysis showed that the genotypes SC02 and ABB2 were clustered into group 1 of zoonotic potential, the genotypes CHB1 and ABB1 were clustered into a new group, and the genotype horse2 was clustered into group 6 of unclear zoonotic potential. In conclusion, this study identified two novel E. bieneusi genotypes in captive Asiatic black bears, and used microsatellite and minisatellite markers to reveal E. bieneusi genetic diversity. Moreover, our findings show that genotypes SC02 (identified in humans) and ABB2 belong to group 1 with zoonotic potential, suggesting the risk of transmission of E. bieneusi from Asiatic black bears to humans and other animals. PMID:28182656

  11. Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Ormeño-Orrillo Ernesto

    2012-12-01

    Full Text Available Abstract Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical

  12. Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    2012-01-01

    Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris) in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym) that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean

  13. SVSVGMKPSPRP: a broad range adhesion peptide.

    Science.gov (United States)

    Estephan, Elias; Dao, Jérôme; Saab, Marie-Belle; Panayotov, Ivan; Martin, Marta; Larroque, Christian; Gergely, Csilla; Cuisinier, Frédéric J G; Levallois, Bernard

    2012-12-01

    A combinatorial phage display approach was previously used to evolve a 12-mer peptide (SVSVGMKPSPRP) with the highest affinity for different semiconductor surfaces. The discovery of the multiple occurrences of the SVSVGMKPSPRP sequence in an all-against-all basic local alignment search tool search of PepBank sequences was unexpected, and a Google search using the peptide sequence recovered 58 results concerning 12 patents and 16 scientific publications. The number of patent and articles indicates that the peptide is perhaps a broad range adhesion peptide. To evaluate peptide properties, we conducted a study to investigate peptide adhesion on different inorganic substrates by mass spectrometry and atomic force microscopy for gold, carbon nanotubes, cobalt, chrome alloy, titanium, and titanium alloy substrates. Our results showed that the peptide has a great potential as a linker to functionalize metallic surfaces if specificity is not a key factor. This peptide is not specific to a particular metal surface, but it is a good linker for the functionalization of a wide range of metallic materials. The fact that this peptide has the potential to adsorb on a large set of inorganic surfaces suggests novel promising directions for further investigation. Affinity determination of SVSVGMKPSPRP peptide would be an important issue for eventual commercial uses.

  14. Parasite host range and the evolution of host resistance

    NARCIS (Netherlands)

    Gorter, F.A.; Hall, A.R.; A., Buckling; P.D., Scanlan

    2015-01-01

    Parasite host range plays a pivotal role in the evolution and ecology of hosts
    and the emergence of infectious disease. Although the factors that promote
    host range and the epidemiological consequences of variation in host range
    are relatively well characterized, the effect of parasite

  15. Fluorescence-based Broad Dynamic Range Viscosity Probes.

    Science.gov (United States)

    Dragan, Anatoliy; Graham, August E; Geddes, Chris D

    2014-03-01

    We introduce two new fluorescent viscosity probes, SYBR Green (SG) and PicoGreen (PG), that we have studied over a broad range of viscosity and in collagen solutions. In water, both dyes have low quantum yields and excited state lifetimes, while in viscous solvents or in complex with DNA both parameters dramatically (300-1000-fold) increase. We show that in log-log scale the dependence of the dyes' quantum yield vs. viscosity is linear, the slope of which is sensitive to temperature. Application of SG and PG, as a fluorescence-based broad dynamic range viscosity probes, to the life sciences is discussed.

  16. [Research progress in the structure and fuction of Orthopoxvirus host range genes].

    Science.gov (United States)

    Liu, Zheng; Liu, Ying; Shao, Yi-Ming

    2013-06-01

    Orthopoxvirus vector has a broad prospect in recombinant vaccine research, but the rarely severe side-effect impedes its development. Vaccinia virus and Cowpox virus of Orthopoxvirus have broad host range, and they have typical host range genes as K1L, CP77 and C7L. These three genes affect host range of Vaccinia virus, disturb the cell signaling pathways, suppress immune response and are related to virulence.

  17. New focal plane detector system for the broad range spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Sjoreen, T.P.

    1984-01-01

    A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60.

  18. Host range evaluation and morphological characterization of ...

    African Journals Online (AJOL)

    A total of 29 isolates of Pseudoperonospora cubensis were collected from various cucurbit farms in West Malaysia. Sporangia of 13 isolates had the ability to germinate at 14°C and were used for host range (pathotype) study using leaf disc assay on a set of twelve cucurbit cultivars. Twelve different pathotypes of P. cubensis ...

  19. Bacteriophage ϕMAM1, a viunalikevirus, is a broad-host-range, high-efficiency generalized transducer that infects environmental and clinical isolates of the enterobacterial genera Serratia and Kluyvera.

    Science.gov (United States)

    Matilla, Miguel A; Salmond, George P C

    2014-10-01

    Members of the enterobacterial genus Serratia are ecologically widespread, and some strains are opportunistic human pathogens. Bacteriophage ϕMAM1 was isolated on Serratia plymuthica A153, a biocontrol rhizosphere strain that produces the potently bioactive antifungal and anticancer haterumalide oocydin A. The ϕMAM1 phage is a generalized transducing phage that infects multiple environmental and clinical isolates of Serratia spp. and a rhizosphere strain of Kluyvera cryocrescens. Electron microscopy allowed classification of ϕMAM1 in the family Myoviridae. Bacteriophage ϕMAM1 is virulent, uses capsular polysaccharides as a receptor, and can transduce chromosomal markers at frequencies of up to 7 × 10(-6) transductants per PFU. We also demonstrated transduction of the complete 77-kb oocydin A gene cluster and heterogeneric transduction of a plasmid carrying a type III toxin-antitoxin system. These results support the notion of the potential ecological importance of transducing phages in the acquisition of genes by horizontal gene transfer. Phylogenetic analyses grouped ϕMAM1 within the ViI-like bacteriophages, and genomic analyses revealed that the major differences between ϕMAM1 and other ViI-like phages arise in a region encoding the host recognition determinants. Our results predict that the wider genus of ViI-like phages could be efficient transducing phages, and this possibility has obvious implications for the ecology of horizontal gene transfer, bacterial functional genomics, and synthetic biology. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  20. Rainbow Vectors for Broad-Range Bacterial Fluorescence Labeling.

    Directory of Open Access Journals (Sweden)

    Mariette Barbier

    Full Text Available Since their discovery, fluorescent proteins have been widely used to study protein function, localization or interaction, promoter activity and regulation, drug discovery or for non-invasive imaging. They have been extensively modified to improve brightness, stability, and oligomerization state. However, only a few studies have focused on understanding the dynamics of fluorescent proteins expression in bacteria. In this work, we developed a set plasmids encoding 12 fluorescent proteins for bacterial labeling to facilitate the study of pathogen-host interactions. These broad-spectrum plasmids can be used with a wide variety of Gram-negative microorganisms including Escherichia coli, Pseudomonas aeruginosa, Burkholderia cepacia, Bordetella bronchiseptica, Shigella flexneri or Klebsiella pneumoniae. For comparison, fluorescent protein expression and physical characteristics in Escherichia coli were analyzed using fluorescence microscopy, flow cytometry and in vivo imaging. Fluorescent proteins derived from the Aequorea Victoria family showed high photobleaching, while proteins form the Discosoma sp. and the Fungia coccina family were more photostable for microscopy applications. Only E2-Crimson, mCherry and mKeima were successfully detected for in vivo applications. Overall, E2-Crimson was the fastest maturing protein tested in E. coli with the best overall performance in the study parameters. This study provides a unified comparison and comprehensive characterization of fluorescent protein photostability, maturation and toxicity, and offers general recommendations on the optimal fluorescent proteins for in vitro and in vivo applications.

  1. Microchip green laser sources: broad range of possibilities

    Science.gov (United States)

    Essaian, Stepan; Khaydarov, John; Slavov, Slav; Ter-Mikirtychev, Vartan; Gabrielyan, Gevorg; Keroopyan, Meruzhan; Soghomonyan, Suren

    2012-02-01

    Spectralus presents its progress in development of miniature, highly efficient, and versatile diode-pumped solid-state (DPSS) green laser source, based on a monolithic cavity microchip laser platform. The use of periodically poled MgO-doped Lithium Niobate (PPMgOLN) as the nonlinear frequency doubler together with gain material Nd3+:YVO4 allows obtaining a significant increase in the overall efficiency of the green microchip laser in comparison with other compact green laser source architectures with comparable output power. Originally, this laser source was designed to be part of the miniature and efficient RGB light source for microdisplay-based (LCOS, DLP or similar) mobile projector devices. Recently, we have extended range of operations for our original laser platform. In particular, we demonstrate the following: high peak power (>500mW), high average power (>200mW), broad temperature range of operation (-30°C - 60°C), and low noise CW operation (<0.5% RMS).

  2. Bloodmeal analysis reveals avian Plasmodium infections and broad host preferences of Culicoides (Diptera: Ceratopogonidae vectors.

    Directory of Open Access Journals (Sweden)

    Diego Santiago-Alarcon

    Full Text Available Changing environmental conditions and human encroachment on natural habitats bring human populations closer to novel sources of parasites, which might then develop into new emerging diseases. Diseases transmitted by host generalist vectors are of special interest due to their capacity to move pathogens into novel hosts. We hypothesize that humans using forests for recreation are exposed to a broad range of parasites from wild animals and their vectors. A corollary of this is that new vector-host, parasite-host, and vector-parasite associations could eventually develop. Thus, we expect to observe atypical vector-host associations. Using molecular bloodmeal analysis via amplification of the mtDNA COI gene we identified the vertebrate hosts of Culicoides (Diptera: Ceratopogonidae species in a sub-urban forest of Southwestern Germany. Bloodmeals were also checked for haemosporidian infections by amplifying a fragment of the mtDNA cyt b gene. We identified a total of 20 Culicoides species, thirteen of which fed on humans. From 105 screened bloodmeals we obtained high quality sequences for 77 samples, 73 (94.8% originated from humans, two from livestock (Bos taurus and Equus caballus, and two from wild birds (Sylvia atricapilla and Turdus merula. We found that four Culicoides species previously assumed to feed exclusively on either birds (C. kibunensis or domestic mammals (C. chiopterus, C. deltus, C. scoticus fed also on humans. A total of six Culicoides abdomens were infected with avian haemosporidian parasites (Plasmodium or Haemoproteus, four of those abdomens contained blood derived from humans. Our results suggest that parasites of wild animals may be transferred to humans through infectious bites of Culicoides vectors. Further, we show that Culicoides vectors believed to be a specialist on specific vertebrate groups can have plastic feeding preferences, and that Culicoides are susceptible to infection by Plasmodium parasites, though vector

  3. Host range of meliolaceous fungi in India

    Directory of Open Access Journals (Sweden)

    V.B. Hosagoudar

    2009-05-01

    Full Text Available The order Meliolales comprises two families, namely, Armatellaceae and Meliolaceae. Except the genera Endomeliola and Pauhia, India represents rest of the nine genera of this group. The family Armatellaceae includes two genera, namely, Armatella and Basavamyces. The family Meliolaceae includes seven genera: Amazonia, Appendiculella, Asteridiella, Ectendomeliola, Irenopsis, Meliola and Prataprajella. All these nine genera represent 613 species and infra-specific taxa known till the year 2006, infected 766 host plants belonging to 349 host genera distributed among 104 families. All the host families and the fungal genera are arranged alphabetically with their corresponding parasite and the host plant. The corresponding number after the host family represents the number of meliolaceous taxa known on the members of that family.

  4. High-productivity mask writer with broad operating range

    Science.gov (United States)

    Baik, Ki-Ho; Chakarian, Varoujan; Dean, Bob; Lu, Maiying; Naber, Robert J.; Newman, Thomas H.; Wiltse, Mark; Abboud, Frank E.

    2001-09-01

    Photomask complexity increases rapidly as semiconductor devices continue to shrink and as optical proximity correction becomes commonplace. This trend stresses the performance of mask pattern generators due to the increase in both primary and subresolution features. However, the next-generation MEBES raster scan architecture is well-suited to the challenge of maintaining throughput regardless of increases in pattern complexity. In addition, this new system provides an operating envelope that is sufficiently broad to expose all practical resist materials with a fixed number of writing passes. Write time is independent of material sensitivity, which has the benefits of allowing high-dose processes to be optimized, and also of supporting a wide selection of chemically amplified resist candidates for critical mask patterning. The new system shows the promise of being extendible to the 70 nm technology generation.

  5. Host range evaluation and morphological characterization of ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... pathogens” with high evolutionary potential (Sarris et al.,. 2008). Pathogenic and morphological variation of this oomycete appear to be correlated with host and environ- mental conditions (Lebeda and Widrlechner, 2003), and significant variation has been found at both the individual and population levels.

  6. Host range of emerald ash borer

    Science.gov (United States)

    Robert A. Haack; Toby R. Petrice; Deborah L. Miller; Leah S. Bauer; Nathan M. Schiff

    2004-01-01

    The emerald ash borer (EAB), Agrilus planipennis Fairmaire, is native to China, Korea, Japan, Mongolia, Russia, and Taiwan (Haack et al. 2002). Established populations of EAB were first discovered in Michigan and Ontario in 2002. Smaller populations, which resulted from human assisted movement of infested host material, were found in Ohio, Maryland,...

  7. Parvoviral host range and cell entry mechanisms.

    Science.gov (United States)

    Cotmore, Susan F; Tattersall, Peter

    2007-01-01

    Parvoviruses elaborate rugged nonenveloped icosahedral capsids of approximately 260 A in diameter that comprise just 60 copies of a common core structural polypeptide. While serving as exceptionally durable shells, capable of protecting the single-stranded DNA genome from environmental extremes, the capsid also undergoes sequential conformational changes that allow it to translocate the genome from its initial host cell nucleus all the way into the nucleus of its subsequent host. Lacking a duplex transcription template, the virus must then wait for its host to enter S-phase before it can initiate transcription and usurp the cell's synthetic pathways. Here we review cell entry mechanisms used by parvoviruses. We explore two apparently distinct modes of host cell specificity, first that used by Minute virus of mice, where subtle glycan-specific interactions between host receptors and residues surrounding twofold symmetry axes on the virion surface mediate differentiated cell type target specificity, while the second involves novel protein interactions with the canine transferrin receptor that allow a mutant of the feline leukopenia serotype, Canine parvovirus, to bind to and infect dog cells. We then discuss conformational shifts in the virion that accompany cell entry, causing exposure of a capsid-tethered phospholipase A2 enzymatic core that acts as an endosomolytic agent to mediate virion translocation across the lipid bilayer into the cell cytoplasm. Finally, we discuss virion delivery into the nucleus, and consider the nature of transcriptionally silent DNA species that, escaping detection by the cell, might allow unhampered progress into S-phase and hence unleash the parvoviral Trojan horse.

  8. Thermosensitive Triterpenoid-Appended Polymers with Broad Temperature Tunability Regulated by Host-Guest Chemistry.

    Science.gov (United States)

    Hao, Jie; Gao, Yuxia; Li, Ying; Yan, Qiang; Hu, Jun; Ju, Yong

    2017-09-05

    Thermoresponsive water-soluble polymers are of great importance since they typically show a lower critical solution temperature (LCST) in aqueous media. In this research, the LCST change in broad temperature ranges of copolymers composed of natural glycyrrhetinic acid (GA)-based methacrylate and N,N'-dimethylacrylamides (DMAs) was investigated as a function of the concentration and the content of GA pendants. By complexation of GA pendants with β-cyclodextrin (β-CD), a side-chain polypseudorotaxane was obtained, which exhibited a significant increase in the LCST of copolymers. Moreover, the precisely reversible control of the LCST behavior was realized through adding a competing guest molecule, sodium 1-admantylcarboxylate. This work illustrates a simple and effective approach to endow water-soluble polymers with broad temperature tunability and helps us further understand the effect of a biocompatible host-guest complementary β-CD/GA pair on the thermoresponsive process. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Broad-scale Population Genetics of the Host Sea Anemone, Heteractis magnifica

    KAUST Repository

    Emms, Madeleine

    2015-12-01

    Broad-scale population genetics can reveal population structure across an organism’s entire range, which can enable us to determine the most efficient population-wide management strategy depending on levels of connectivity. Genetic variation and differences in genetic diversity on small-scales have been reported in anemones, but nothing is known about their broad-scale population structure, including that of “host” anemone species, which are increasingly being targeted in the aquarium trade. In this study, microsatellite markers were used as a tool to determine the population structure of a sessile, host anemone species, Heteractis magnifica, across the Indo-Pacific region. In addition, two rDNA markers were used to identify Symbiodinium from the samples, and phylogenetic analyses were used to measure diversity and geographic distribution of Symbiodinium across the region. Significant population structure was identified in H. magnifica across the Indo-Pacific, with at least three genetic breaks, possibly the result of factors such as geographic distance, geographic isolation and environmental variation. Symbiodinium associations were also affected by environmental variation and supported the geographic isolation of some regions. These results suggests that management of H. magnifica must be implemented on a local scale, due to the lack of connectivity between clusters. This study also provides further evidence for the combined effects of geographic distance and environmental distance in explaining genetic variance.

  10. A novel, broad-range, CTXΦ-derived stable integrative expression vector for functional studies.

    Science.gov (United States)

    Das, Bhabatosh; Kumari, Reena; Pant, Archana; Sen Gupta, Sourav; Saxena, Shruti; Mehta, Ojasvi; Nair, Gopinath Balakrish

    2014-12-01

    CTXΦ, a filamentous vibriophage encoding cholera toxin, uses a unique strategy for its lysogeny. The single-stranded phage genome forms intramolecular base-pairing interactions between two inversely oriented XerC and XerD binding sites (XBS) and generates a functional phage attachment site, attP(+), for integration. The attP(+) structure is recognized by the host-encoded tyrosine recombinases XerC and XerD (XerCD), which enables irreversible integration of CTXΦ into the chromosome dimer resolution site (dif) of Vibrio cholerae. The dif site and the XerCD recombinases are widely conserved in bacteria. We took advantage of these conserved attributes to develop a broad-host-range integrative expression vector that could irreversibly integrate into the host chromosome using XerCD recombinases without altering the function of any known open reading frame (ORF). In this study, we engineered two different arabinose-inducible expression vectors, pBD62 and pBD66, using XBS of CTXΦ. pBD62 replicates conditionally and integrates efficiently into the dif of the bacterial chromosome by site-specific recombination using host-encoded XerCD recombinases. The expression level of the gene of interest could be controlled through the PBAD promoter by modulating the functions of the vector-encoded transcriptional factor AraC. We validated the irreversible integration of pBD62 into a wide range of pathogenic and nonpathogenic bacteria, such as V. cholerae, Vibrio fluvialis, Vibrio parahaemolyticus, Escherichia coli, Salmonella enterica, and Klebsiella pneumoniae. Gene expression from the PBAD promoter of integrated vectors was confirmed in V. cholerae using the well-studied reporter genes mCherry, eGFP, and lacZ. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  11. Nanoporous Anodic Alumina 3D FDTD Modelling for a Broad Range of Inter-pore Distances.

    Science.gov (United States)

    Bertó-Roselló, Francesc; Xifré-Pérez, Elisabet; Ferré-Borrull, Josep; Pallarès, Josep; Marsal, Lluis F

    2016-12-01

    The capability of the finite difference time domain (FDTD) method for the numerical modelling of the optical properties of nanoporous anodic alumina (NAA) in a broad range of inter-pore distances is evaluated. FDTD permits taking into account in the same numerical framework all the structural features of NAA, such as the texturization of the interfaces or the incorporation of electrolyte anions in the aluminium oxide host. The evaluation is carried out by comparing reflectance measurements from two samples with two very different inter-pore distances with the simulation results. Results show that considering the texturization is crucial to obtain good agreement with the measurements. On the other hand, including the anionic layer in the model leads to a second-order contribution to the reflectance spectrum.

  12. Broad-scale phylogenomics provides insights into retrovirus–host evolution

    Science.gov (United States)

    Hayward, Alexander; Grabherr, Manfred; Jern, Patric

    2013-01-01

    Genomic data provide an excellent resource to improve understanding of retrovirus evolution and the complex relationships among viruses and their hosts. In conjunction with broad-scale in silico screening of vertebrate genomes, this resource offers an opportunity to complement data on the evolution and frequency of past retroviral spread and so evaluate future risks and limitations for horizontal transmission between different host species. Here, we develop a methodology for extracting phylogenetic signal from large endogenous retrovirus (ERV) datasets by collapsing information to facilitate broad-scale phylogenomics across a wide sample of hosts. Starting with nearly 90,000 ERVs from 60 vertebrate host genomes, we construct phylogenetic hypotheses and draw inferences regarding the designation, host distribution, origin, and transmission of the Gammaretrovirus genus and associated class I ERVs. Our results uncover remarkable depths in retroviral sequence diversity, supported within a phylogenetic context. This finding suggests that current infectious exogenous retrovirus diversity may be underestimated, adding credence to the possibility that many additional exogenous retroviruses may remain to be discovered in vertebrate taxa. We demonstrate a history of frequent horizontal interorder transmissions from a rodent reservoir and suggest that rats may have acted as important overlooked facilitators of gammaretrovirus spread across diverse mammalian hosts. Together, these results demonstrate the promise of the methodology used here to analyze large ERV datasets and improve understanding of retroviral evolution and diversity for utilization in wider applications. PMID:24277832

  13. Broad-scale phylogenomics provides insights into retrovirus-host evolution.

    Science.gov (United States)

    Hayward, Alexander; Grabherr, Manfred; Jern, Patric

    2013-12-10

    Genomic data provide an excellent resource to improve understanding of retrovirus evolution and the complex relationships among viruses and their hosts. In conjunction with broad-scale in silico screening of vertebrate genomes, this resource offers an opportunity to complement data on the evolution and frequency of past retroviral spread and so evaluate future risks and limitations for horizontal transmission between different host species. Here, we develop a methodology for extracting phylogenetic signal from large endogenous retrovirus (ERV) datasets by collapsing information to facilitate broad-scale phylogenomics across a wide sample of hosts. Starting with nearly 90,000 ERVs from 60 vertebrate host genomes, we construct phylogenetic hypotheses and draw inferences regarding the designation, host distribution, origin, and transmission of the Gammaretrovirus genus and associated class I ERVs. Our results uncover remarkable depths in retroviral sequence diversity, supported within a phylogenetic context. This finding suggests that current infectious exogenous retrovirus diversity may be underestimated, adding credence to the possibility that many additional exogenous retroviruses may remain to be discovered in vertebrate taxa. We demonstrate a history of frequent horizontal interorder transmissions from a rodent reservoir and suggest that rats may have acted as important overlooked facilitators of gammaretrovirus spread across diverse mammalian hosts. Together, these results demonstrate the promise of the methodology used here to analyze large ERV datasets and improve understanding of retroviral evolution and diversity for utilization in wider applications.

  14. Development of expanded host range phage active on biofilms of multi-drug resistant Pseudomonas aeruginosa

    Science.gov (United States)

    Mapes, Abigail C.; Trautner, Barbara W.; Liao, Kershena S.; Ramig, Robert F.

    2016-01-01

    ABSTRACT Phage therapy is a promising treatment of multi-drug resistant (MDR) bacterial infections but is limited by the narrow host range of phage. To overcome this limitation, we developed a host range expansion (HRE) protocol that expands the host range of Pseudomonas aeruginosa-specific phage by cycles of co-incubation of phage with multiple P. aeruginosa strains. Application of the HRE protocol to a mixture of 4 phages, using 16 P. aeruginosa strains for development, resulted in undefined phage mixtures with greatly expanded host range. Individual phage clones derived from the undefined mixture had expanded host ranges but no individual clone could lyse all of the strains covered by the undefined mixture from which it was isolated. Reconstituting host range-characterized clones into cocktails produced defined cocktails with predictable and broad host ranges. The undefined mixture from the 30th cycle of the mixed-phage HRE (4ϕC30) showed a dose-dependent ability to prevent biofilm formation by, and to reduce a pre-existing biofilm of, 3 P. aeruginosa clinical isolates that produced high amounts of biofilm. A defined cocktail reconstituted from 3 host range-characterized clones had activity on high biofilm-formers susceptible to the phage. Phage therapy was superior to antibiotic therapy (levofloxacin) in a strain of P. aeruginosa that was resistant to levofloxacin. The HRE protocol establishes a rapid approach to create libraries of phage clones and phage cocktails with broad host range, defined composition and anti-biofilm activity. PMID:27144083

  15. Characterization of non-host resistance in broad bean to the wheat stripe rust pathogen

    Directory of Open Access Journals (Sweden)

    Cheng Yulin

    2012-06-01

    Full Text Available Abstract Background Non-host resistance (NHR confers plant species immunity against the majority of microbial pathogens and represents the most robust and durable form of plant resistance in nature. As one of the main genera of rust fungi with economic and biological importance, Puccinia infects almost all cereals but is unable to cause diseases on legumes. Little is known about the mechanism of this kind of effective defense in legumes to these non-host pathogens. Results In this study, the basis of NHR in broad bean (Vicia faba L. against the wheat stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst, was characterized. No visible symptoms were observed on broad bean leaves inoculated with Pst. Microscopic observations showed that successful location of stomata and haustoria formation were significantly reduced in Pst infection of broad bean. Attempted infection induced the formation of papillae, cell wall thickening, production of reactive oxygen species, callose deposition and accumulation of phenolic compounds in plant cell walls. The few Pst haustoria that did form in broad bean cells were encased in reactive oxygen and callose materials and those cells elicited cell death. Furthermore, a total of seven defense-related genes were identified and found to be up-regulated during the Pst infection. Conclusions The results indicate that NHR in broad bean against Pst results from a continuum of layered defenses, including basic incompatibility, structural and chemical strengthening of cell wall, posthaustorial hypersensitive response and induction of several defense-related genes, demonstrating the multi-layered feature of NHR. This work also provides useful information for further determination of resistance mechanisms in broad bean to rust fungi, especially the adapted important broad bean rust pathogen, Uromyces viciae-fabae, because of strong similarity and association between NHR of plants to unadapted pathogens and basal

  16. Wide host-range cloning for functional metagenomics.

    Science.gov (United States)

    Wexler, Margaret; Johnston, Andrew W B

    2010-01-01

    We describe how wide host-range cloning vectors can lead to more flexible and effective procedures to isolate novel genes by screening metagenomic libraries in a range of bacterial hosts, not just the conventionally used Escherichia coli. We give examples of various wide host-range plasmid, cosmid, and BAC cloning vectors and the types of genes and activities that have been successfully obtained to date. We present a detailed protocol that involves the construction and screening of a metagenomic library comprising fragments of bacterial DNA, obtained from a wastewater treatment plant and cloned in a wide host-range cosmid. We also consider future prospects and how techniques and tools can be improved.

  17. Invasion success of a scarab beetle within its native range: host range expansion versus host-shift

    Directory of Open Access Journals (Sweden)

    Marie-Caroline Lefort

    2014-02-01

    Full Text Available Only recently has it been formally acknowledged that native species can occasionally reach the status of ‘pest’ or ‘invasive species’ within their own native range. The study of such species has potential to help unravel fundamental aspects of biological invasions. A good model for such a study is the New Zealand native scarab beetle, Costelytra zealandica (White, which even in the presence of its natural enemies has become invasive in exotic pastures throughout the country. Because C. zealandica still occurs widely within its native habitat, we hypothesised that this species has only undergone a host range expansion (ability to use equally both an ancestral and new host onto exotic hosts rather than a host shift (loss of fitness on the ancestral host in comparison to the new host. Moreover, this host range expansion could be one of the main drivers of its invasion success. In this study, we investigated the fitness response of populations of C. zealandica from native and exotic flora, to several feeding treatments comprising its main exotic host plant as well as one of its ancestral hosts. Our results suggest that our initial hypothesis was incorrect and that C. zealandica populations occurring in exotic pastures have experienced a host-shift rather than simply a host-range expansion. This finding suggests that an exotic plant introduction can facilitate the evolution of a distinct native host-race, a phenomenon often used as evidence for speciation in phytophagous insects and which may have been instrumental to the invasion success of C. zealandica.

  18. Preference of diamondback moth larvae for novel and original host plant after host range expansion

    NARCIS (Netherlands)

    Henniges-Janssen, K.; Heckel, D.G.; Groot, A.T.

    2014-01-01

    Utilization of a novel plant host by herbivorous insects requires coordination of numerous physiological and behavioral adaptations in both larvae and adults. The recent host range expansion of the crucifer-specialist diamondback moth (DBM), Plutella xylostella L. (Lepidoptera: Plutellidae), to the

  19. HOST PLANT UTILIZATION, HOST RANGE OSCILLATIONS AND DIVERSIFICATION IN NYMPHALID BUTTERFLIES: A PHYLOGENETIC INVESTIGATION

    Science.gov (United States)

    Nylin, Sören; Slove, Jessica; Janz, Niklas

    2014-01-01

    It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the “oscillation hypothesis.” In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. PMID:24372598

  20. Determinants of host species range in plant viruses.

    Science.gov (United States)

    Moury, Benoît; Fabre, Frédéric; Hébrard, Eugénie; Froissart, Rémy

    2017-04-01

    Prediction of pathogen emergence is an important field of research, both in human health and in agronomy. Most studies of pathogen emergence have focused on the ecological or anthropic factors involved rather than on the role of intrinsic pathogen properties. The capacity of pathogens to infect a large set of host species, i.e. to possess a large host range breadth (HRB), is tightly linked to their emergence propensity. Using an extensive plant virus database, we found that four traits related to virus genome or transmission properties were strongly and robustly linked to virus HRB. Broader host ranges were observed for viruses with single-stranded genomes, those with three genome segments and nematode-transmitted viruses. Also, two contrasted groups of seed-transmitted viruses were evidenced. Those with a single-stranded genome had larger HRB than non-seed-transmitted viruses, whereas those with a double-stranded genome (almost exclusively RNA) had an extremely small HRB. From the plant side, the family taxonomic rank appeared as a critical threshold for virus host range, with a highly significant increase in barriers to infection between plant families. Accordingly, the plant-virus infectivity matrix shows a dual structure pattern: a modular pattern mainly due to viruses specialized to infect plants of a given family and a nested pattern due to generalist viruses. These results contribute to a better prediction of virus host jumps and emergence risks.

  1. Xylella fastidiosa: Host Range and Advance in Molecular Identification Techniques

    Science.gov (United States)

    Baldi, Paolo; La Porta, Nicola

    2017-01-01

    In the never ending struggle against plant pathogenic bacteria, a major goal is the early identification and classification of infecting microorganisms. Xylella fastidiosa, a Gram-negative bacterium belonging to the family Xanthmonadaceae, is no exception as this pathogen showed a broad range of vectors and host plants, many of which may carry the pathogen for a long time without showing any symptom. Till the last years, most of the diseases caused by X. fastidiosa have been reported from North and South America, but recently a widespread infection of olive quick decline syndrome caused by this fastidious pathogen appeared in Apulia (south-eastern Italy), and several cases of X. fastidiosa infection have been reported in other European Countries. At least five different subspecies of X. fastidiosa have been reported and classified: fastidiosa, multiplex, pauca, sandyi, and tashke. A sixth subspecies (morus) has been recently proposed. Therefore, it is vital to develop fast and reliable methods that allow the pathogen detection during the very early stages of infection, in order to prevent further spreading of this dangerous bacterium. To this purpose, the classical immunological methods such as ELISA and immunofluorescence are not always sensitive enough. However, PCR-based methods exploiting specific primers for the amplification of target regions of genomic DNA have been developed and are becoming a powerful tool for the detection and identification of many species of bacteria. The aim of this review is to illustrate the application of the most commonly used PCR approaches to X. fastidiosa study, ranging from classical PCR, to several PCR-based detection methods: random amplified polymorphic DNA (RAPD), quantitative real-time PCR (qRT-PCR), nested-PCR (N-PCR), immunocapture PCR (IC-PCR), short sequence repeats (SSRs, also called VNTR), single nucleotide polymorphisms (SNPs) and multilocus sequence typing (MLST). Amplification and sequence analysis of specific

  2. Xylella fastidiosa: Host Range and Advance in Molecular Identification Techniques

    Directory of Open Access Journals (Sweden)

    Paolo Baldi

    2017-06-01

    Full Text Available In the never ending struggle against plant pathogenic bacteria, a major goal is the early identification and classification of infecting microorganisms. Xylella fastidiosa, a Gram-negative bacterium belonging to the family Xanthmonadaceae, is no exception as this pathogen showed a broad range of vectors and host plants, many of which may carry the pathogen for a long time without showing any symptom. Till the last years, most of the diseases caused by X. fastidiosa have been reported from North and South America, but recently a widespread infection of olive quick decline syndrome caused by this fastidious pathogen appeared in Apulia (south-eastern Italy, and several cases of X. fastidiosa infection have been reported in other European Countries. At least five different subspecies of X. fastidiosa have been reported and classified: fastidiosa, multiplex, pauca, sandyi, and tashke. A sixth subspecies (morus has been recently proposed. Therefore, it is vital to develop fast and reliable methods that allow the pathogen detection during the very early stages of infection, in order to prevent further spreading of this dangerous bacterium. To this purpose, the classical immunological methods such as ELISA and immunofluorescence are not always sensitive enough. However, PCR-based methods exploiting specific primers for the amplification of target regions of genomic DNA have been developed and are becoming a powerful tool for the detection and identification of many species of bacteria. The aim of this review is to illustrate the application of the most commonly used PCR approaches to X. fastidiosa study, ranging from classical PCR, to several PCR-based detection methods: random amplified polymorphic DNA (RAPD, quantitative real-time PCR (qRT-PCR, nested-PCR (N-PCR, immunocapture PCR (IC-PCR, short sequence repeats (SSRs, also called VNTR, single nucleotide polymorphisms (SNPs and multilocus sequence typing (MLST. Amplification and sequence analysis of

  3. Xylella fastidiosa: Host Range and Advance in Molecular Identification Techniques.

    Science.gov (United States)

    Baldi, Paolo; La Porta, Nicola

    2017-01-01

    In the never ending struggle against plant pathogenic bacteria, a major goal is the early identification and classification of infecting microorganisms. Xylella fastidiosa, a Gram-negative bacterium belonging to the family Xanthmonadaceae, is no exception as this pathogen showed a broad range of vectors and host plants, many of which may carry the pathogen for a long time without showing any symptom. Till the last years, most of the diseases caused by X. fastidiosa have been reported from North and South America, but recently a widespread infection of olive quick decline syndrome caused by this fastidious pathogen appeared in Apulia (south-eastern Italy), and several cases of X. fastidiosa infection have been reported in other European Countries. At least five different subspecies of X. fastidiosa have been reported and classified: fastidiosa, multiplex, pauca, sandyi, and tashke. A sixth subspecies (morus) has been recently proposed. Therefore, it is vital to develop fast and reliable methods that allow the pathogen detection during the very early stages of infection, in order to prevent further spreading of this dangerous bacterium. To this purpose, the classical immunological methods such as ELISA and immunofluorescence are not always sensitive enough. However, PCR-based methods exploiting specific primers for the amplification of target regions of genomic DNA have been developed and are becoming a powerful tool for the detection and identification of many species of bacteria. The aim of this review is to illustrate the application of the most commonly used PCR approaches to X. fastidiosa study, ranging from classical PCR, to several PCR-based detection methods: random amplified polymorphic DNA (RAPD), quantitative real-time PCR (qRT-PCR), nested-PCR (N-PCR), immunocapture PCR (IC-PCR), short sequence repeats (SSRs, also called VNTR), single nucleotide polymorphisms (SNPs) and multilocus sequence typing (MLST). Amplification and sequence analysis of specific

  4. The host range of Phomopsis cirsii

    DEFF Research Database (Denmark)

    Leth, Vibeke; Andreasen, Christian

    2012-01-01

    echinus, Cirsiumvulgare and Cynaracardunculusvar.scolymus (artichoke) with symptoms such as restricted necrotic leaf spots and too early senescence or death of entire leaf. Eleven hosts for P. cirsii were recorded but despite the expanded range of hosts we expect that its host range will be within...... Cardueae.P.cirsii,poses multi-target potential against several annual and biennial weedy thistles from warmer climates. The pathogenicity of P. cirsii towards the artichoke, however, could limit its field of application especially in the Mediterranean area. The potential of P. cirsii as a control agent......, in areas where artichokes are cultivated, would depend on the existence of P.cirsii resistant varieties or the existence of P.cirsiiisolates non-pathogenic to artichoke....

  5. Foot-and-mouth disease: Host range and pathogenesis

    DEFF Research Database (Denmark)

    Alexandersen, Søren; Mowat, N.

    2005-01-01

    In this chapter the host range of foot-and-mouth disease (FMD) under natural and experimental conditions is reviewed. The routes and sites of infection, incubation periods and clinical and pathological findings are described and highlighted in relation to progress in understanding the pathogenesis...... of FMD....

  6. Interspecific hybridization impacts host range and pathogenicity of filamentous microbes.

    Science.gov (United States)

    Depotter, Jasper Rl; Seidl, Michael F; Wood, Thomas A; Thomma, Bart Phj

    2016-08-01

    Interspecific hybridization is widely observed within diverse eukaryotic taxa, and is considered an important driver for genome evolution. As hybridization fuels genomic and transcriptional alterations, hybrids are adept to respond to environmental changes or to invade novel niches. This may be particularly relevant for organisms that establish symbiotic relationships with host organisms, such as mutualistic symbionts, endophytes and pathogens. The latter group is especially well-known for engaging in everlasting arms races with their hosts. Illustrated by the increased identification of hybrid pathogens with altered virulence or host ranges when compared with their parental lineages, it appears that hybridization is a strong driver for pathogen evolution, and may thus significantly impact agriculture and natural ecosystems. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  7. Climate driven range divergence among host species affects range-wide patterns of parasitism

    Directory of Open Access Journals (Sweden)

    Richard E. Feldman

    2017-01-01

    Full Text Available Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose and Rangifer tarandus (caribou, in North America. We used MaxEnt models to predict the recent (2000 and future (2050 ranges (probabilities of occurrence of the cervids and a parasite Parelaphostrongylus tenuis (brainworm taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.

  8. Activation of toll-like receptors and dendritic cells by a broad range of bacterial molecules

    NARCIS (Netherlands)

    Boele, L.C.L.; Bajramovic, J.J.; Vries, A.M.M.B.C. de; Voskamp-Visser, I.A.I.; Kaman, W.E.; Kleij, D. van der

    2009-01-01

    Activation of pattern recognition receptors such as Toll-like receptors (TLRs) by pathogens leads to activation and maturation of dendritic cells (DC), which orchestrate the development of the adaptive immune response. To create an overview of the effects of a broad range of pathogenic bacteria,

  9. Characterization of a broad range antibacterial substance from a new Bacillus species isolated from Amazon basin.

    Science.gov (United States)

    Motta, Amanda S; Cannavan, Fabiana S; Tsai, Siu-Mui; Brandelli, Adriano

    2007-10-01

    A Bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16S rDNA sequencing. The phylogenetic analysis indicated that this strain has low sequence similarity with most Bacillus spp., suggesting a new species was isolated. The antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. The substance was inhibitory to a broad range of indicator strains, including pathogenic and food spoilage bacteria such as Listeria monocytogenes, B. cereus, Aeromonas hydrophila, Erwinia carotovora, Pasteurella haemolytica, Salmonella Gallinarum, among other. The antibacterial substance was stable over a wide pH range, but it was sensitive to pronase E and lipase. The antibacterial substance was bactericidal and bacteriolytic to L. monocytogenes and B. cereus at 160 AU ml(-1). The identification of a broad range bacteriocin-like inhibitory substance active against L. monocytogenes addresses an important aspect of food protection against pathogens and spoilage microorganisms.

  10. Eilat virus host range restriction is present at multiple levels of the virus life cycle.

    Science.gov (United States)

    Nasar, Farooq; Gorchakov, Rodion V; Tesh, Robert B; Weaver, Scott C

    2015-01-15

    Most alphaviruses are mosquito-borne and exhibit a broad host range, infecting many different vertebrates, including birds, rodents, equids, humans, and nonhuman primates. This ability of most alphaviruses to infect arthropods and vertebrates is essential for their maintenance in nature. Recently, a new alphavirus, Eilat virus (EILV), was described, and in contrast to all other mosquito-borne viruses, it is unable to replicate in vertebrate cell lines. Investigations into the nature of its host range restriction showed the inability of genomic EILV RNA to replicate in vertebrate cells. Here, we investigated whether the EILV host range restriction is present at the entry level and further explored the viral factors responsible for the lack of genomic RNA replication. Utilizing Sindbis virus (SINV) and EILV chimeras, we show that the EILV vertebrate host range restriction is also manifested at the entry level. Furthermore, the EILV RNA replication restriction is independent of the 3' untranslated genome region (UTR). Complementation experiments with SINV suggested that RNA replication is restricted by the inability of the EILV nonstructural proteins to form functional replicative complexes. These data demonstrate that the EILV host range restriction is multigenic, involving at least one gene from both nonstructural protein (nsP) and structural protein (sP) open reading frames (ORFs). As EILV groups phylogenetically within the mosquito-borne virus clade of pathogenic alphaviruses, our findings have important evolutionary implications for arboviruses. Our work explores the nature of host range restriction of the first "mosquito-only alphavirus," EILV. EILV is related to pathogenic mosquito-borne viruses (Eastern equine encephalitis virus [EEEV], Western equine encephalitis virus [WEEV], Venezuelan equine encephalitis virus [VEEV], and Chikungunya virus [CHIKV]) that cause severe disease in humans. Our data demonstrate that EILV is restricted both at entry and genomic

  11. Diverse wild bird host range of Mycoplasma gallisepticum in eastern North America.

    Directory of Open Access Journals (Sweden)

    André A Dhondt

    Full Text Available Emerging infectious diseases often result from pathogens jumping to novel hosts. Identifying possibilities and constraints on host transfer is therefore an important facet of research in disease ecology. Host transfers can be studied for the bacterium Mycoplasma gallisepticum, predominantly a pathogen of poultry until its 1994 appearance and subsequent epidemic spread in a wild songbird, the house finch Haemorhous mexicanus and some other wild birds. We screened a broad range of potential host species for evidence of infection by M. gallisepticum in order to answer 3 questions: (1 is there a host phylogenetic constraint on the likelihood of host infection (house finches compared to other bird species; (2 does opportunity for close proximity (visiting bird feeders increase the likelihood of a potential host being infected; and (3 is there seasonal variation in opportunity for host jumping (winter resident versus summer resident species. We tested for pathogen exposure both by using PCR to test for the presence of M. gallisepticum DNA and by rapid plate agglutination to test for the presence of antibodies. We examined 1,941 individual birds of 53 species from 19 avian families. In 27 species (15 families there was evidence for exposure with M. gallisepticum although conjunctivitis was very rare in non-finches. There was no difference in detection rate between summer and winter residents, nor between feeder birds and species that do not come to feeders. Evidence of M. gallisepticum infection was found in all species for which at least 20 individuals had been sampled. Combining the present results with those of previous studies shows that a diverse range of wild bird species may carry or have been exposed to M. gallisepticum in the USA as well as in Europe and Asia.

  12. Inhibition of influenza virus replication by targeting broad host cell pathways.

    Directory of Open Access Journals (Sweden)

    Isabelle Marois

    Full Text Available Antivirals that are currently used to treat influenza virus infections target components of the virus which can mutate rapidly. Consequently, there has been an increase in the number of resistant strains to one or many antivirals in recent years. Here we compared the antiviral effects of lysosomotropic alkalinizing agents (LAAs and calcium modulators (CMs, which interfere with crucial events in the influenza virus replication cycle, against avian, swine, and human viruses of different subtypes in MDCK cells. We observed that treatment with LAAs, CMs, or a combination of both, significantly inhibited viral replication. Moreover, the drugs were effective even when they were administered 8 h after infection. Finally, analysis of the expression of viral acidic polymerase (PA revealed that both drugs classes interfered with early events in the viral replication cycle. This study demonstrates that targeting broad host cellular pathways can be an efficient strategy to inhibit influenza replication. Furthermore, it provides an interesting avenue for drug development where resistance by the virus might be reduced since the virus is not targeted directly.

  13. Optimizing Taq polymerase concentration for improved signal-to-noise in the broad range detection of low abundance bacteria.

    Directory of Open Access Journals (Sweden)

    Rudolph Spangler

    Full Text Available BACKGROUND: PCR in principle can detect a single target molecule in a reaction mixture. Contaminating bacterial DNA in reagents creates a practical limit on the use of PCR to detect dilute bacterial DNA in environmental or public health samples. The most pernicious source of contamination is microbial DNA in DNA polymerase preparations. Importantly, all commercial Taq polymerase preparations inevitably contain contaminating microbial DNA. Removal of DNA from an enzyme preparation is problematical. METHODOLOGY/PRINCIPAL FINDINGS: This report demonstrates that the background of contaminating DNA detected by quantitative PCR with broad host range primers can be decreased greater than 10-fold through the simple expedient of Taq enzyme dilution, without altering detection of target microbes in samples. The general method is: For any thermostable polymerase used for high-sensitivity detection, do a dilution series of the polymerase crossed with a dilution series of DNA or bacteria that work well with the test primers. For further work use the concentration of polymerase that gave the least signal in its negative control (H(2O while also not changing the threshold cycle for dilutions of spiked DNA or bacteria compared to higher concentrations of Taq polymerase. CONCLUSIONS/SIGNIFICANCE: It is clear from the studies shown in this report that a straightforward procedure of optimizing the Taq polymerase concentration achieved "treatment-free" attenuation of interference by contaminating bacterial DNA in Taq polymerase preparations. This procedure should facilitate detection and quantification with broad host range primers of a small number of bona fide bacteria (as few as one in a sample.

  14. RNA sequencing analysis of the broad-host-range strain Sinorhizobium fredii NGR234 identifies a large set of genes linked to quorum sensing-dependent regulation in the background of a traI and ngrI deletion mutant.

    Science.gov (United States)

    Krysciak, Dagmar; Grote, Jessica; Rodriguez Orbegoso, Mariita; Utpatel, Christian; Förstner, Konrad U; Li, Lei; Schmeisser, Christel; Krishnan, Hari B; Streit, Wolfgang R

    2014-09-01

    The alphaproteobacterium Sinorhizobium fredii NGR234 has an exceptionally wide host range, as it forms nitrogen-fixing nodules with more legumes than any other known microsymbiont. Within its 6.9-Mbp genome, it encodes two N-acyl-homoserine-lactone synthase genes (i.e., traI and ngrI) involved in the biosynthesis of two distinct autoinducer I-type molecules. Here, we report on the construction of an NGR234-ΔtraI and an NGR234-ΔngrI mutant and their genome-wide transcriptome analysis. A high-resolution RNA sequencing (RNA-seq) analysis of early-stationary-phase cultures in the NGR234-ΔtraI background suggested that up to 316 genes were differentially expressed in the NGR234-ΔtraI mutant versus the parent strain. Similarly, in the background of NGR234-ΔngrI 466 differentially regulated genes were identified. Accordingly, a common set of 186 genes was regulated by the TraI/R and NgrI/R regulon. Coregulated genes included 42 flagellar biosynthesis genes and 22 genes linked to exopolysaccharide (EPS) biosynthesis. Among the genes and open reading frames (ORFs) that were differentially regulated in NGR234-ΔtraI were those linked to replication of the pNGR234a symbiotic plasmid and cytochrome c oxidases. Biotin and pyrroloquinoline quinone biosynthesis genes were differentially expressed in the NGR234-ΔngrI mutant as well as the entire cluster of 21 genes linked to assembly of the NGR234 type III secretion system (T3SS-II). Further, we also discovered that genes responsible for rhizopine catabolism in NGR234 were strongly repressed in the presence of high levels of N-acyl-homoserine-lactones. Together with nodulation assays, the RNA-seq-based findings suggested that quorum sensing (QS)-dependent gene regulation appears to be of higher relevance during nonsymbiotic growth rather than for life within root nodules. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  15. Species boundaries and host range of tortoise mites (Uropodoidea phoretic on bark beetles (Scolytinae, using morphometric and molecular markers.

    Directory of Open Access Journals (Sweden)

    Wayne Knee

    Full Text Available Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae, but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1 morphologically defined species are supported by molecular data, and that (2 bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI and nuclear large subunit ribosomal DNA (28S. Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists.

  16. Species boundaries and host range of tortoise mites (Uropodoidea) phoretic on bark beetles (Scolytinae), using morphometric and molecular markers.

    Science.gov (United States)

    Knee, Wayne; Beaulieu, Frédéric; Skevington, Jeffrey H; Kelso, Scott; Cognato, Anthony I; Forbes, Mark R

    2012-01-01

    Understanding the ecology and evolutionary history of symbionts and their hosts requires accurate taxonomic knowledge, including clear species boundaries and phylogenies. Tortoise mites (Mesostigmata: Uropodoidea) are among the most diverse arthropod associates of bark beetles (Curculionidae: Scolytinae), but their taxonomy and host associations are largely unstudied. We tested the hypotheses that (1) morphologically defined species are supported by molecular data, and that (2) bark beetle uropodoids with a broad host range comprise cryptic species. To do so, we assessed the species boundaries of uropodoid mites collected from 51 host species, across 11 countries and 103 sites, using morphometric data as well as partial cytochrome oxidase I (COI) and nuclear large subunit ribosomal DNA (28S). Overall, morphologically defined species were confirmed by molecular datasets, with a few exceptions. Twenty-nine of the 36 uropodoid species (Trichouropoda, Nenteria and Uroobovella) collected in this study had narrow host ranges, while seven species had putative broad host ranges. In all but one species, U. orri, our data supported the existence of these host generalists, which contrasts with the typical finding that widespread generalists are actually complexes of cryptic specialists.

  17. Time-of-flight electron spectrometer for a broad range of kinetic energies

    Energy Technology Data Exchange (ETDEWEB)

    Kothe, Alexander; Metje, Jan; Wilke, Martin; Moguilevski, Alexandre; Engel, Nicholas; Al-Obaidi, Ruba; Richter, Clemens; Golnak, Ronny; Kiyan, Igor Yu.; Aziz, Emad F. [Joint Ultrafast Dynamics Lab in Solutions and at Interfaces (JULiq), Helmholtz-Zentrum Berlin fuer Materialien und Energie (HZB), Albert-Einstein-Str. 15, 12489 Berlin (Germany) and Freie Universitaet Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin (Germany)

    2013-02-15

    A newly constructed time-of-flight electron spectrometer of the magnetic bottle type is characterized for electron detection in a broad range of kinetic energies. The instrument is designed to measure the energy spectra of electrons generated from liquids excited by strong laser fields and photons in the range of extreme ultra violet and soft X-rays. Argon inner shell electrons were recorded to calibrate the spectrometer and investigate its characteristics, such as energy resolution and collection efficiency. Its energy resolution {Delta}E/E of 1.6% allows resolving the Ar 2p spin orbit structure at kinetic energies higher than 100 eV. The collection efficiency is determined and compared to that of the spectrometer in its field-free configuration.

  18. Geographic and host range of the nematode Soboliphyme baturini across Beringia.

    Science.gov (United States)

    Koehler, Anson V A; Hoberg, Eric P; Dokuchaev, Nikolai E; Cook, Joseph A

    2007-10-01

    The nematode Soboliphyme baturini Petrov, 1930, was found to represent a single species with a relatively broad geographic range across Beringia and northwestern North America on the basis of the assessment of molecular sequence data for adult and juvenile parasites. Refuted are hypotheses suggesting that several cryptic species could be partitioned either among an array of mustelid definitive hosts or across the vast region that links North America and Eurasia. Host specificity for this species is examined on the basis of a comprehensive list for definitive hosts, derived from new field surveys and existing literature for S. baturini. Only 5 mustelids (Gulo gulo, Martes americana, M. caurina, M. zibellina, and Neovison vison) appear to have significant roles in the life history, persistence, and transmission of this nematode. Soboliphyme baturini readily switches among M. americana, M. caurina, Mustela erminea, or N. vison at any particular locality throughout its geographic range in North America, although Martes spp. could represent the source for nematodes in a broader array of mustelids. Molecular analyses (243 base pairs of mitochondrial gene nicotinamide dehydrogenase [ND4]) suggest that hypotheses for host specificity across an array of mustelid definitive hosts are not supported. The life cycle of S. baturini is explored through a review of diet literature for 2 marten species, M. americana and M. caurina, and other mustelids across the Holarctic. Shrews (Soricomorpha: Soricidae) comprise >8% of prey for these species of Martes, suggesting their putative role as paratenic hosts. Juvenile nematodes found in the diaphragms of soricids are genetically identical to adult S. baturini found in the stomachs of mustelids at the same locations in both Asia and North America, corroborating a role in transmission for species of Sorex.

  19. Characterization of a broad host-spectrum virulent Salmonella bacteriophage fmb-p1 and its application on duck meat.

    Science.gov (United States)

    Wang, Changbao; Chen, Qiming; Zhang, Chong; Yang, Jie; Lu, Zhaoxin; Lu, Fengxia; Bie, Xiaomei

    2017-05-15

    The aim of this study was to find a virulent bacteriophage for the biocontrol of Salmonella in duck meat. A broad host-spectrum virulent phage, fmb-p1, was isolated and purified from an duck farm, and its host range was determined to include S. Typhimurium, S. Enteritidis, S. Saintpaul, S. Agona, S. Miami, S. Anatum, S. Heidelberg and S. Paratyphi-C. Electron microscopy and genome sequencing showed that fmb-p1 belongs to the family Siphoviridae. The genome of fmb-p1 is composed of a 43,327-bp double-stranded DNA molecule with 60 open reading frames and a total G+C content of 46.09%. There are no deleterious sequences or genes encoding known harmful products in the phage fmb-p1 genome. Phage fmb-p1 was stable under different temperature (40-75°C), pH (4-10) and NaCl solutions (1-11%). The phage treatment (9.9×10 9 PFU/cm 2 ) caused a peak reduction in S. Typhimurium of 4.52 log CFU/cm 2 in ready-to-eat (RTE) duck meat, whereas potassium sorbate treatment (PS, 2mg/cm 2 ) resulted in a 0.05-0.12 log reduction. Compared to PS treatment, there was significant difference in the S. Typhimurium reduction (P˂0.05) by phage treatment at both 4°C and 25°C. The results suggested that phage could be applied to reduce Salmonella, on commercial poultry products. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Relaxations in metallic glasses investigated by a broad frequency and temperature range

    Energy Technology Data Exchange (ETDEWEB)

    Bedorf, Dennis; Koeppe, Thomas; Hachenberg, Joerg; Samwer, Konrad [I. Physikalisches Institut, Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Kahl, Annelen [Keck Laboratories MS 138-78 Caltech, Pasadena CA 91125 (United States); Richert, Ranko [Department of Chemistry and Biochemistry, Arizona State University, Tempe AZ 85287-1604 (United States)

    2007-07-01

    We are interested in glassy dynamics and the atomistic processes leading to different relaxations in amorphous materials. To measure the complex elastic constants, two mechanical spectroscopy techniques were employed. The use of a double-paddle-oscillator (DPO) provides sufficient sensitivity to investigate the loss of even thin films. A DPO is driven in eigenfrequency mode at 5.4 kHz and an amorphous metallic film (PdCuSi) is evaporated onto it and measured under UHV conditions. Cooling and heating enables measurements in a broad temperature range with different heating rates. To survey the elastic constants at higher frequencies, an ultrasonic spectroscopy technique in the MHz regime is used. The pulse-echo method is applied to a bulk metallic glass in order to obtain the shear modulus and attenuation by monitoring shear wave propagation. The results are discussed in the framework of the Cooperative Shear Model.

  1. Monoglyceride-based organogelator for broad-range oil uptake with high capacity.

    Science.gov (United States)

    Wang, Dong; Niu, Jian; Wang, Zhenggong; Jin, Jian

    2015-02-10

    Oil/water separation has been a worldwide subject because of increasing release of oil-containing wastewater as well as several marine oil spills. The phase-selective organogelators (PSOGs) are thought to offer a potential and effective implement for addressing this issue. An ideal PSOG for oil adsorption must fulfill some requirements involving effective gelation, easy synthesis, low cost, and recyclable for reuse. However, beyond those, the ability of gelation for a broad-range oil phase without selectivity is also important. However, most of the reported PSOGs have limitation in this respect thus far. In this paper, a new class of saturated 1-monoglyceride-derived organogelators can efficiently uptake almost all of the common fuel oils from water and gelate organic solvents with extremely low minimum gelation concentration (MGC). In addition, the oils in the gel and gelator molecules can be recovered quantitatively through simple vacuum distillation.

  2. Metabolic Value Chemoattractants Are Preferentially Recognized at Broad Ligand Range Chemoreceptor of Pseudomonas putida KT2440

    Directory of Open Access Journals (Sweden)

    Matilde Fernández

    2017-05-01

    Full Text Available Bacteria have evolved a wide range of chemoreceptors with different ligand specificities. Typically, chemoreceptors bind ligands with elevated specificity and ligands serve as growth substrates. However, there is a chemoreceptor family that has a broad ligand specificity including many compounds that are not of metabolic value. To advance the understanding of this family, we have used the PcaY_PP (PP2643 chemoreceptor of Pseudomonas putida KT2440 as a model. Using Isothermal Titration Calorimetry we showed here that the recombinant ligand binding domain (LBD of PcaY_PP recognizes 17 different C6-ring containing carboxylic acids with KD values between 3.7 and 138 μM and chemoeffector affinity correlated with the magnitude of the chemotactic response. Mutation of the pcaY_PP gene abolished chemotaxis to these compounds; phenotype that was restored following gene complementation. Growth experiments using PcaY_PP ligands as sole C-sources revealed functional relationships between their metabolic potential and affinity for the chemoreceptor. Thus, only 7 PcaY_PP ligands supported growth and their KD values correlated with the length of the bacterial lag phase. Furthermore, PcaY_PP ligands that did not support growth had significantly higher KD values than those that did. The receptor has thus binds preferentially compounds that serve as C-sources and amongst them those that rapidly promote growth. Tightest binding compounds were quinate, shikimate, 3-dehydroshikimate and protocatechuate, which are at the interception of the biosynthetic shikimate and catabolic quinate pathways. Analytical ultracentrifugation studies showed that ligand free PcaY_PP-LBD is present in a monomer-dimer equilibrium (KD = 57.5 μM. Ligand binding caused a complete shift to the dimeric state, which appears to be a general feature of four-helix bundle LBDs. This study indicates that the metabolic potential of compounds is an important parameter in the molecular recognition

  3. Evolution of host range in the follicle mite Demodex kutzeri.

    Science.gov (United States)

    Palopoli, Michael F; Tra, VAN; Matoin, Kassey; Mac, Phuong D

    2017-04-01

    The sequences of four mitochondrial genes were determined for Demodex mites isolated from two distantly related species within the family Cervidae, and identified morphologically as belonging to the species Demodex kutzeri. The sequences were used to test the hypothesis that Demodex are strictly host-specific, and hence cospeciate with their hosts: (1) The estimated divergence time between mites found on elk vs humans agreed closely with a previous estimate of the time that these host species last shared a common ancestor, suggesting cospeciation of mites and hosts, at least over long evolutionary timescales. (2) The extremely low levels of sequence divergence between the mites found on elk vs mule deer hosts indicated that these mites belong to the same species, which suggests that Demodex are able to move across host species boundaries over shorter timescales. Together, the results are consistent with the model that Demodex mites are not strict host-specialists, but instead lose the ability to move between host lineages gradually.

  4. Enhanced primers for amplification of DNA barcodes from a broad range of marine metazoans.

    Science.gov (United States)

    Lobo, Jorge; Costa, Pedro M; Teixeira, Marcos A L; Ferreira, Maria S G; Costa, Maria H; Costa, Filipe O

    2013-09-10

    Building reference libraries of DNA barcodes is relatively straightforward when specifically designed primers are available to amplify the COI-5P region from a relatively narrow taxonomic group (e.g. single class or single order). DNA barcoding marine communities have been comparatively harder to accomplish due to the broad taxonomic diversity and lack of consistently efficient primers. Although some of the so-called "universal" primers have been relatively successful, they still fail to amplify COI-5P of many marine animal groups, while displaying random success even among species within each group. Here we propose a new pair of primers designed to enhance amplification of the COI-5P region in a wide range of marine organisms. Amplification tests conducted on a wide range of marine animal taxa, rendered possible the first-time sequencing of DNA barcodes from eight separated phyla (Annelida, Arthropoda, Chordata, Cnidaria, Echinodermata, Mollusca, Nemertea and Platyhelminthes), comprising a total of 14 classes, 28 orders, 57 families, 68 genus and 76 species. These primers demonstrated to be highly cost-effective, which is of key importance for DNA barcoding procedures, such as for building comprehensive DNA barcode libraries of marine communities, where the processing of a large numbers of specimens from a wide variety of marine taxa is compulsory.

  5. Noradrenaline transmission reducing drugs may protect against a broad range of diseases.

    Science.gov (United States)

    Fitzgerald, P J

    2015-04-01

    1 A growing body of evidence suggests that the signalling molecule, noradrenaline (NA), plays a pathophysiological role in a broad range of psychiatric, neurological and peripheral disorders. Both preclinical and clinical data suggest that elevated NA signalling may be involved in the aetiology of major diseases such as depression, Alzheimer's disease and diabetes mellitus. 2 The molecular pathways by which NA may cause the manifestation of disease remain poorly understood, although they may include G protein-coupled receptor modulation of the Ras/MAP kinase, Stat3 and PI3K pathways, among others. In both individual animals and humans, NA tone may be elevated largely due to genetics, but also because of the exposure to marked psychological stress or trauma, or other environmental factors. 3 As NA is involved in the 'fight or flight' response by the sympathetic nervous system, this transmitter may be elevated in a large number of organisms due to evolutionary selection of enhancing responses to immediate environmental dangers. Likewise, acetylcholine signalling by the parasympathetic ('rest and digest') nervous system may be relatively diminished. This putative autonomic imbalance may result in diminished engagement in homeostatic processes, resulting in the emergence and progression of a number of diseases throughout the body. 4 In this scenario, a large number of individuals may benefit from chronic use of pharmacological agents - such as clonidine, guanfacine, propranolol or prazosin - that diminish NA signalling throughout the body. If so, NA transmission lowering drugs may protect against a wide range of diseases. © 2014 John Wiley & Sons Ltd.

  6. Potent autologous and heterologous neutralizing antibody responses occur in HIV-2 infection across a broad range of infection outcomes.

    Science.gov (United States)

    de Silva, Thushan I; Aasa-Chapman, Marlén; Cotten, Matthew; Hué, Stéphane; Robinson, James; Bibollet-Ruche, Frederic; Sarge-Njie, Ramu; Berry, Neil; Jaye, Assan; Aaby, Peter; Whittle, Hilton; Rowland-Jones, Sarah; Weiss, Robin

    2012-01-01

    Few studies have explored the role of neutralizing antibody (NAb) responses in controlling HIV-2 viremia and disease progression. Using a TZM-bl neutralization assay, we assessed heterologous and autologous NAb responses from a community cohort of HIV-2-infected individuals with a broad range of disease outcomes in rural Guinea-Bissau. All subjects (n = 40) displayed exceptionally high heterologous NAb titers (50% inhibitory plasma dilution or 50% inhibitory concentration [IC(50)], 1:7,000 to 1:1,000,000) against 5 novel primary HIV-2 envelopes and HIV-2 7312A, whereas ROD A and 3 primary envelopes were relatively resistant to neutralization. Most individuals also showed high autologous NAb against contemporaneous envelopes (78% of plasma-envelope combinations in 69 envelopes from 21 subjects), with IC(50)s above 1:10,000. No association between heterologous or autologous NAb titer and greater control of HIV-2 was found. A subset of envelopes was found to be more resistant to neutralization (by plasma and HIV-2 monoclonal antibodies). These envelopes were isolated from individuals with greater intrapatient sequence diversity and were associated with changes in potential N-linked glycosylation sites but not CD4 independence or CXCR4 use. Plasma collected from up to 15 years previously was able to potently neutralize recent autologous envelopes, suggesting a lack of escape from NAb and the persistence of neutralization-sensitive variants over time, despite significant NAb pressure. We conclude that despite the presence of broad and potent NAb responses in HIV-2-infected individuals, these are not the primary forces behind the dichotomous outcomes observed but reveal a limited capacity for adaptive selection and escape from host immunity in HIV-2 infection.

  7. Oxidative Stress and Mitochondrial Dysfunction across Broad-Ranging Pathologies: Toward Mitochondria-Targeted Clinical Strategies

    Directory of Open Access Journals (Sweden)

    Giovanni Pagano

    2014-01-01

    Full Text Available Beyond the disorders recognized as mitochondrial diseases, abnormalities in function and/or ultrastructure of mitochondria have been reported in several unrelated pathologies. These encompass ageing, malformations, and a number of genetic or acquired diseases, as diabetes and cardiologic, haematologic, organ-specific (e.g., eye or liver, neurologic and psychiatric, autoimmune, and dermatologic disorders. The mechanistic grounds for mitochondrial dysfunction (MDF along with the occurrence of oxidative stress (OS have been investigated within the pathogenesis of individual disorders or in groups of interrelated disorders. We attempt to review broad-ranging pathologies that involve mitochondrial-specific deficiencies or rely on cytosol-derived prooxidant states or on autoimmune-induced mitochondrial damage. The established knowledge in these subjects warrants studies aimed at elucidating several open questions that are highlighted in the present review. The relevance of OS and MDF in different pathologies may establish the grounds for chemoprevention trials aimed at compensating OS/MDF by means of antioxidants and mitochondrial nutrients.

  8. Personal glucose meters for detection and quantification of a broad range of analytes

    Science.gov (United States)

    Lu, Yi; Xiang, Yu

    2015-02-03

    A general methodology for the development of highly sensitive and selective sensors that can achieve portable, low-cost and quantitative detection of a broad range of targets using only a personal glucose meter (PGM) is disclosed. The method uses recognition molecules that are specific for a target agent, enzymes that can convert an enzyme substrate into glucose, and PGM. Also provided are sensors, which can include a solid support to which is attached a recognition molecule that permits detection of a target agent, wherein the recognition molecule specifically binds to the target agent in the presence of the target agent but not significantly to other agents as well as an enzyme that can catalyze the conversion of a substance into glucose, wherein the enzyme is attached directly or indirectly to the recognition molecule, and wherein in the presence of the target agent the enzyme can convert the substance into glucose. The disclosed sensors can be part of a lateral flow device. Methods of using such sensors for detecting target agents are also provided.

  9. Tuning the Polarization State of Light over a Broad Frequency Range with Metasurfaces

    Science.gov (United States)

    Wang, Mu; Jiang, Shang-Chi; Wang, Zheng-Han; Xiong, Xiang; Peng, Ru-Wen; Nanjing University Team

    Controlling the polarization state, the transmission direction and the phase of light within a confined space is an important issue in optics. By integrating metallic metastructure and dielectric interlayer, it is possible to realize the dispersion-free broadband device on sub-wavelength scale, where the strong response of the metallic structures helps to decrease the device size while the dielectric interlayer helps to eliminate the dispersion simultaneously in both the amplitude and the phase difference of the reflected/transmitted light. As an examples to apply this concept, a broadband quarter-wave plate and a half-wave plate are experimentally demonstrated. By carefully selecting the structural parameters, the polarization state of light can be freely tuned across a broad frequency range, and all of the polarization states on the Poincaré sphere can be realized dispersion free. Some contents of this talk can be found in the following references: [1] S.-C. Jiang, et al., High-efficiency generation of circularly polarized light via symmetry-induced anomalous reflection,Physical Review B 91, 125421 (2015), [2] S.-C. Jiang, et al., Controlling the Polarization State of Light with a Dispersion-Free Metastructure, Physical Review X 4, 021026 (2014), [3] X. Xiong, et al., Metallic stereostructured layer: an approach for broadband polarization state manipulation,Applied Physics Letters 105, 201105 (2014).

  10. Forest response to elevated CO2 is conserved across a broad range of productivity

    Science.gov (United States)

    Norby, Richard J.; DeLucia, Evan H.; Gielen, Birgit; Calfapietra, Carlo; Giardina, Christian P.; King, John S.; Ledford, Joanne; McCarthy, Heather R.; Moore, David J. P.; Ceulemans, Reinhart; De Angelis, Paolo; Finzi, Adrien C.; Karnosky, David F.; Kubiske, Mark E.; Lukac, Martin; Pregitzer, Kurt S.; Scarascia-Mugnozza, Giuseppe E.; Schlesinger, William H.; Oren, Ram

    2005-01-01

    Climate change predictions derived from coupled carbon-climate models are highly dependent on assumptions about feedbacks between the biosphere and atmosphere. One critical feedback occurs if C uptake by the biosphere increases in response to the fossil-fuel driven increase in atmospheric [CO2] (“CO2 fertilization”), thereby slowing the rate of increase in atmospheric [CO2]. Carbon exchanges between the terrestrial biosphere and atmosphere are often first represented in models as net primary productivity (NPP). However, the contribution of CO2 fertilization to the future global C cycle has been uncertain, especially in forest ecosystems that dominate global NPP, and models that include a feedback between terrestrial biosphere metabolism and atmospheric [CO2] are poorly constrained by experimental evidence. We analyzed the response of NPP to elevated CO2 (≈550 ppm) in four free-air CO2 enrichment experiments in forest stands. We show that the response of forest NPP to elevated [CO2] is highly conserved across a broad range of productivity, with a stimulation at the median of 23 ± 2%. At low leaf area indices, a large portion of the response was attributable to increased light absorption, but as leaf area indices increased, the response to elevated [CO2] was wholly caused by increased light-use efficiency. The surprising consistency of response across diverse sites provides a benchmark to evaluate predictions of ecosystem and global models and allows us now to focus on unresolved questions about carbon partitioning and retention, and spatial variation in NPP response caused by availability of other growth limiting resources. PMID:16330779

  11. Assessment of biofilm removal capacity of a broad host range bacteriophage JHP against Pseudomonas aeruginosa.

    Science.gov (United States)

    Shafique, Muafia; Alvi, Iqbal Ahmad; Abbas, Zaigham; Ur Rehman, Shafiq

    2017-06-01

    Pseudomonas aeruginosa is an efficient biofilm-dwelling microbial pathogen, associated with nosocomial infections. These biofilm-associated infections are resistant to antibiotics and immune defenses, therefore pose major problem against their treatment. This scenario demands alternative therapeutic regimens, and bacteriophage therapy is one among potential strategies for clinical management of multiple drug resistance. In this investigation, the efficacy of a bacteriophage, JHP, is evaluated to eradicate P. aeruginosa biofilms. Growth kinetics of P. aeruginosa biofilm revealed that the highest cell density biofilm (1.5 × 1016 CFU/mL) was established within the polystyrene microtiter plate at 72 h post inoculation. Pseudomonas aeruginosa biofilms of different ages, treated with JHP (0.6 MOI) for different post-infection durations, reduced biomass from 2 to 4.5 logs (60-90%). JHP treatment before biofilm development reduced the bacterial load up to 9 logs (>95% bacterial load reduction) as compared with untreated control, which highlights its potential to prevent biofilm formation in indwelling medical devices. Combinations of JHP with other phages or antibiotics could be an efficient alternative for P. aeruginosa biofilm removal in clinical and industrial settings. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  12. Diversification of broad host range plasmids correlates with the presence of antibiotic resistance genes.

    Science.gov (United States)

    Li, Xiaobin; Wang, Yafei; Brown, Celeste J; Yao, Fei; Jiang, Yong; Top, Eva M; Li, Hui

    2016-01-01

    The IncP-1ε subgroup is a recently identified phylogenetic clade within IncP-1 plasmids, which plays an important role in the spread of antibiotic resistance and degradation of xenobiotic pollutants. Here, four IncP-1ε plasmids were exogenously captured from a petroleum-contaminated habitat in China and compared phylogenetically and genomically with previously reported IncP-1ε and other IncP-1 plasmids. The IncP-1ε plasmids can be clearly subdivided into two subclades, designated as ε-I and ε-II, based on phylogenetic analysis of backbone proteins TraI and TrfA. This was further supported by comparison of concatenated backbone genes. Moreover, the two subclades differed in the transposon types, phenotypes and insertion locations of the accessory elements. The accessory genes on ε-I plasmids were inserted between parA and traC, and harbored ISPa17 and Tn402-like transposon modules, typically carrying antibiotic resistance genes. In contrast, the accessory elements on ε-II plasmids were typically located between trfA and oriV, and contained IS1071, which was commonly inserted within the Tn501-like transposon, typically harboring a cluster of genes encoding mercury resistance and/or catabolic pathways. Our study is one of the first to compare IncP-1 plasmid genomes from China, expands the available collection of IncP-1ε plasmids and enhances our understanding of their diversity, biogeography and evolutionary history. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Genome sequencing and comparative genomics of the broad host-range pathogen Rhizoctonia solani AG8.

    Directory of Open Access Journals (Sweden)

    James K Hane

    2014-05-01

    Full Text Available Rhizoctonia solani is a soil-borne basidiomycete fungus with a necrotrophic lifestyle which is classified into fourteen reproductively incompatible anastomosis groups (AGs. One of these, AG8, is a devastating pathogen causing bare patch of cereals, brassicas and legumes. R. solani is a multinucleate heterokaryon containing significant heterozygosity within a single cell. This complexity posed significant challenges for the assembly of its genome. We present a high quality genome assembly of R. solani AG8 and a manually curated set of 13,964 genes supported by RNA-seq. The AG8 genome assembly used novel methods to produce a haploid representation of its heterokaryotic state. The whole-genomes of AG8, the rice pathogen AG1-IA and the potato pathogen AG3 were observed to be syntenic and co-linear. Genes and functions putatively relevant to pathogenicity were highlighted by comparing AG8 to known pathogenicity genes, orthology databases spanning 197 phytopathogenic taxa and AG1-IA. We also observed SNP-level "hypermutation" of CpG dinucleotides to TpG between AG8 nuclei, with similarities to repeat-induced point mutation (RIP. Interestingly, gene-coding regions were widely affected along with repetitive DNA, which has not been previously observed for RIP in mononuclear fungi of the Pezizomycotina. The rate of heterozygous SNP mutations within this single isolate of AG8 was observed to be higher than SNP mutation rates observed across populations of most fungal species compared. Comparative analyses were combined to predict biological processes relevant to AG8 and 308 proteins with effector-like characteristics, forming a valuable resource for further study of this pathosystem. Predicted effector-like proteins had elevated levels of non-synonymous point mutations relative to synonymous mutations (dN/dS, suggesting that they may be under diversifying selection pressures. In addition, the distant relationship to sequenced necrotrophs of the Ascomycota suggests the R. solani genome sequence may prove to be a useful resource in future comparative analysis of plant pathogens.

  14. Range monitoring in South Africa: a broad perspective. | A.J. ...

    African Journals Online (AJOL)

    Language: English. Keywords: Monitoring goals; Range condition assessments; Resource conservation; range condition assessment; range monitoring; monitoring; context; temporal changes; change; response; management strategy; south ...

  15. Testing and validation of high density resequencing microarray for broad range biothreat agents detection.

    Directory of Open Access Journals (Sweden)

    Tomasz A Leski

    Full Text Available Rapid and effective detection and identification of emerging microbiological threats and potential biowarfare agents is very challenging when using traditional culture-based methods. Contemporary molecular techniques, relying upon reverse transcription and/or polymerase chain reaction (RT-PCR/PCR provide a rapid and effective alternative, however, such assays are generally designed and optimized to detect only a limited number of targets, and seldom are capable of differentiation among variants of detected targets. To meet these challenges, we have designed a broad-range resequencing pathogen microarray (RPM for detection of tropical and emerging infectious agents (TEI including biothreat agents: RPM-TEI v 1.0 (RPM-TEI. The scope of the RPM-TEI assay enables detection and differential identification of 84 types of pathogens and 13 toxin genes, including most of the class A, B and C select agents as defined by the Centers for Disease Control and Prevention (CDC, Atlanta, GA. Due to the high risks associated with handling these particular target pathogens, the sensitivity validation of the RPM-TEI has been performed using an innovative approach, in which synthetic DNA fragments are used as templates for testing the assay's limit of detection (LOD. Assay specificity and sensitivity was subsequently confirmed by testing with full-length genomic nucleic acids of selected agents. The LOD for a majority of the agents detected by RPM-TEI was determined to be at least 10(4 copies per test. Our results also show that the RPM-TEI assay not only detects and identifies agents, but is also able to differentiate near neighbors of the same agent types, such as closely related strains of filoviruses of the Ebola Zaire group, or the Machupo and Lassa arenaviruses. Furthermore, each RPM-TEI assay results in specimen-specific agent gene sequence information that can be used to assess pathogenicity, mutations, and virulence markers, results that are not generally

  16. Host-range evolution in Aphidius parasitoids: fidelity, virulence and fitness trade-offs on an ancestral host.

    Science.gov (United States)

    Henry, Lee M; Roitberg, Bernard D; Gillespie, David R

    2008-03-01

    The diversity of parasitic insects remains one of the most conspicuous patterns on the planet. The principal factor thought to contribute to differentiation of populations and ultimately speciation is the intimate relationship parasites share with hosts and the potential for disruptive selection associated with using different host species. Traits that generate this diversity have been an intensely debated topic of central importance to the evolution of specialization and maintenance of ecological diversity. A fundamental hypothesis surrounding the evolution of specialization is that no single genotype is uniformly superior in all environments. This "trade-off" hypothesis suggests that negative fitness correlations can lead to specialization on different hosts as alternative stable strategies. In this study we demonstrate a trade-off in the ability of the parasitoid, Aphidius ervi, to maintain a high level of fitness on an ancestral and novel host, which suggests a genetic basis for host utilization that may limit host-range expansion in parasitoids. Furthermore, behavioral evidence suggests mechanisms that could promote specialization through induced host fidelity. Results are discussed in the context of host-affiliated ecological selection as a potential source driving diversification in parasitoid communities and the influence of host species heterogeneity on population differentiation and local adaptation.

  17. Broad-temperature range spectroscopy of the two-centre modular redox metalloprotein Desulfovibrio desulfuricans desulfoferrodoxin

    DEFF Research Database (Denmark)

    Andersen, Niels Højmark; Harnung, S.E.; Trabjerg, I.

    2003-01-01

    /VIS, MCD, CD, and EPR spectroscopy. The UV/VIS spectra of grey DFx at room temperature is characterised by broad charge transfer (CT) transitions associated with oxidised centre 1 (495 and 368 nm) and II (335 and 635 nm). The transitions are resolved at 78 K, substantiated by VT-MCD and -CD. The data offer...

  18. Absorption spectroscopy of complex rare earth ion doped hybrid materials over a broad wavelength range

    NARCIS (Netherlands)

    Dekker, R.; Worhoff, Kerstin; Stouwdam, J.W.; van Veggel, F.C.J.M.; Driessen, A.

    In the present work we applied a measurement setup to determine several relevant properties of rare-earth doped nanoparticles dispersed in polymer slab waveguides in a single absorption measurement: background absorption of the polymer host material, water absorption, polymer composition

  19. Absorption spectroscopy of complex rare earth ion doped hybrid materials over a broad wavelength range

    NARCIS (Netherlands)

    Dekker, R.; Worhoff, Kerstin; Stouwdam, J.W.; van Veggel, F.C.J.M.; Driessen, A.

    2005-01-01

    In the present work we applied a measurement setup to determine several relevant properties of rare-earth doped nanoparticles dispersed in polymer slab waveguides in a single absorption measurement: background absorption of the polymer host material, water absorption, polymer composition

  20. Frequency and fitness consequences of bacteriophage φ6 host range mutations.

    Directory of Open Access Journals (Sweden)

    Brian E Ford

    Full Text Available Viruses readily mutate and gain the ability to infect novel hosts, but few data are available regarding the number of possible host range-expanding mutations allowing infection of any given novel host, and the fitness consequences of these mutations on original and novel hosts. To gain insight into the process of host range expansion, we isolated and sequenced 69 independent mutants of the dsRNA bacteriophage Φ6 able to infect the novel host, Pseudomonas pseudoalcaligenes. In total, we found at least 17 unique suites of mutations among these 69 mutants. We assayed fitness for 13 of 17 mutant genotypes on P. pseudoalcaligenes and the standard laboratory host, P. phaseolicola. Mutants exhibited significantly lower fitnesses on P. pseudoalcaligenes compared to P. phaseolicola. Furthermore, 12 of the 13 assayed mutants showed reduced fitness on P. phaseolicola compared to wildtype Φ6, confirming the prevalence of antagonistic pleiotropy during host range expansion. Further experiments revealed that the mechanistic basis of these fitness differences was likely variation in host attachment ability. In addition, using computational protein modeling, we show that host-range expanding mutations occurred in hotspots on the surface of the phage's host attachment protein opposite a putative hydrophobic anchoring domain.

  1. Enhanced primers for amplification of DNA barcodes from a broad range of marine metazoans

    OpenAIRE

    Lobo, Jorge; Costa, Pedro M; Teixeira, Marcos AL; Ferreira, Maria SG; Costa, Maria H; Costa, Filipe O

    2013-01-01

    Background Building reference libraries of DNA barcodes is relatively straightforward when specifically designed primers are available to amplify the COI-5P region from a relatively narrow taxonomic group (e.g. single class or single order). DNA barcoding marine communities have been comparatively harder to accomplish due to the broad taxonomic diversity and lack of consistently efficient primers. Although some of the so-called ?universal? primers have been relatively successful, they still f...

  2. Geographically structured host specificity is caused by the range expansions and host shifts of a symbiotic fungus

    Science.gov (United States)

    Wolfe, Benjamin E; Pringle, Anne

    2012-01-01

    The inability to associate with local species may constrain the spread of mutualists arriving to new habitats, but the fates of introduced, microbial mutualists are largely unknown. The deadly poisonous ectomycorrhizal fungus Amanita phalloides (the death cap) is native to Europe and introduced to the East and West Coasts of North America. By cataloging host associations across the two continents, we record dramatic changes in specificity among the three ranges. On the East Coast, where the fungus is restricted in its distribution, it associates almost exclusively with pines, which are rarely hosts of A. phalloides in its native range. In California, where the fungus is widespread and locally abundant, it associates almost exclusively with oaks, mirroring the host associations observed in Europe. The most common host of the death cap in California is the endemic coast live oak (Quercus agrifolia), and the current distribution of A. phalloides appears constrained within the distribution of Q. agrifolia. In California, host shifts to native plants are also associated with a near doubling in the resources allocated to sexual reproduction and a prolonged fruiting period; mushrooms are twice as large as they are elsewhere and mushrooms are found throughout the year. Host and niche shifts are likely to shape the continuing range expansion of A. phalloides and other ectomycorrhizal fungi introduced across the world. PMID:22134645

  3. Gene family expansions and contractions are associated with host range in plant pathogens of the genus Colletotrichum.

    Science.gov (United States)

    Baroncelli, Riccardo; Amby, Daniel Buchvaldt; Zapparata, Antonio; Sarrocco, Sabrina; Vannacci, Giovanni; Le Floch, Gaétan; Harrison, Richard J; Holub, Eric; Sukno, Serenella A; Sreenivasaprasad, Surapareddy; Thon, Michael R

    2016-08-05

    Many species belonging to the genus Colletotrichum cause anthracnose disease on a wide range of plant species. In addition to their economic impact, the genus Colletotrichum is a useful model for the study of the evolution of host specificity, speciation and reproductive behaviors. Genome projects of Colletotrichum species have already opened a new era for studying the evolution of pathogenesis in fungi. We sequenced and annotated the genomes of four strains in the Colletotrichum acutatum species complex (CAsc), a clade of broad host range pathogens within the genus. The four CAsc proteomes and secretomes along with those representing an additional 13 species (six Colletotrichum spp. and seven other Sordariomycetes) were classified into protein families using a variety of tools. Hierarchical clustering of gene family and functional domain assignments, and phylogenetic analyses revealed lineage specific losses of carbohydrate-active enzymes (CAZymes) and proteases encoding genes in Colletotrichum species that have narrow host range as well as duplications of these families in the CAsc. We also found a lineage specific expansion of necrosis and ethylene-inducing peptide 1 (Nep1)-like protein (NLPs) families within the CAsc. This study illustrates the plasticity of Colletotrichum genomes, and shows that major changes in host range are associated with relatively recent changes in gene content.

  4. Diagnosis of ventricular drainage-related bacterial meningitis by broad-range real-time polymerase chain reaction

    DEFF Research Database (Denmark)

    Deutch, Susanna; Dahlberg, Daniel; Hedegaard, Jesper

    2007-01-01

    OBJECTIVE: To compare a broad-range real-time polymerase chain reaction (PCR) diagnostic strategy with culture to evaluate additional effects on the etiological diagnosis and the quantification of the bacterial load during the course of ventricular drainage-related bacterial meningitis (VR...

  5. Promoting Equitable Biology Lab Instruction by Engaging All Students in a Broad Range of Science Practices: An Exploratory Study

    Science.gov (United States)

    Strimaitis, Anna M.; Southerland, Sherry A.; Sampson, Victor; Enderle, Patrick; Grooms, Jonathon

    2017-01-01

    This study examines what students enrolled in the honors and general sections of a high school biology course offered at the same school learn when they have an opportunity to participate in a broad or narrow range of science practices during their laboratory experiences. The results of our analysis suggest that the students enrolled in the…

  6. Synthesis and Characterization of a Micelle-Based pH Nanosensor with an Unprecedented Broad Measurement Range

    DEFF Research Database (Denmark)

    Ek, Pramod Kumar; Feldborg, Lise N.; Almdal, Kristoffer

    2013-01-01

    ) carboxyfluorescein and a reference fluorophore Alexa 633 to the PAEMA shell region of the micelles. Fluorescence measurements show that these pH nanosensors are sensitive in a surprisingly broad pH range of 3.4–8.0, which is hypothesized to be due to small differences in the individual fluorophores’ local...

  7. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments

    DEFF Research Database (Denmark)

    Zhang, M.; Søndergaard, Rikke Vicki; Ek, Pramod Kumar

    2015-01-01

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements...... of acidic intracellular pH (pH nanosensors. In this paper we successfully developed a multiple sensor, a fluorophore based nanosensor, with an unprecedented broad measurement range from pH 1.4 to 7.0. In this nanosensor, three p......H-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured...

  8. High performance small molecule photodetector with broad spectral response range from 200 to 900 nm

    Science.gov (United States)

    Wu, Shuang-hong; Li, Wen-lian; Chu, Bei; Su, Zi-sheng; Zhang, Feng; Lee, C. S.

    2011-07-01

    We demonstrate a photodetector (PD) with broad spectral response by taking the advantages of more flexible device design in using small molecule materials. The optimized device shows an external quantum efficiency of over 20% from 200 to 900 nm. The high performance is achieved by jointing two donor (D)/acceptor (A) hetero-junctions [m-MTDATA(D)/TiOPc(A) and TiOPc(D)/F16CuPc: PTCDI-C8(A)] such that photoresponses over the deep-ultraviolet (UV) and visible-near infrared regions can be independently optimized. By choosing D- and A-materials with matched energy level alignment, high carrier mobility, and balanced carrier transporting properties, the present PD shows a fast response of 56 ns. The high speed and deep-UV sensitivity might lead to potential military applications such as missile tracking in addition to optical communications, chemical/biological sensing etc.

  9. A broad range quorum sensing inhibitor working through sRNA inhibition

    DEFF Research Database (Denmark)

    Jakobsen, Tim H.; Warming, Anders N.; Vejborg, Rebecca M.

    2017-01-01

    that the repressing effect of ajoene on quorum sensing occurs by inhibition of small regulatory RNAs (sRNA) in P. aeruginosa as well as in Staphylococcus aureus, another important human pathogen that employs quorum sensing to control virulence gene expression. Using various reporter constructs, we found that ajoene...... virulence factors such as hemolysins and proteases were lowered in the presence of ajoene in S. aureus. Importantly, our findings show that sRNAs across bacterial species potentially may qualify as targets of anti-virulence therapy and that ajoene could be a lead structure in search of broad...... lowered expression of the sRNAs RsmY and RsmZ in P. aeruginosa and the small dual-function regulatory RNA, RNAIII in S. aureus, that controls expression of key virulence factors. We confirmed the modulation of RNAIII by RNA sequencing and found that the expression of many QS regulated genes encoding...

  10. Diversity of Bacillus cereus group strains is reflected in their broad range of pathogenicity and diverse ecological lifestyles.

    Science.gov (United States)

    Ceuppens, Siele; Boon, Nico; Uyttendaele, Mieke

    2013-06-01

    Bacillus cereus comprises a highly versatile group of bacteria, which are of particular interest because of their capacity to cause disease. Emetic food poisoning is caused by the toxin cereulide produced during the growth of emetic B. cereus in food, while diarrhoeal food poisoning is the result of enterotoxin production by viable vegetative B. cereus cells in the small intestine, probably in the mucus layer and/or attached to the host's intestinal epithelium. The numbers of B. cereus causing disease are highly variable, depending on diverse factors linked to the host (age, diet, physiology and immunology), bacteria (cellular form, toxin genes and expression) and food (nutritional composition and meal characteristics). Bacillus cereus group strains show impressive ecological diversity, ranging from their saprophytic life cycle in soil to symbiotic (commensal and mutualistic) lifestyles near plant roots and in guts of insects and mammals to various pathogenic ones in diverse insect and mammalian hosts. During all these different ecological lifestyles, their toxins play important roles ranging from providing competitive advantages within microbial communities to inhibition of specific pathogenic organisms for their host and accomplishment of infections by damaging their host's tissues. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  11. Study of transmission line attenuation in broad band millimeter wave frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Hitesh Kumar B. [ITER-India, IPR, Gandhinagar, Gujarat (India); Austin, M. E. [Institute for Fusion Studies, the University of Texas at Austin, Austin, Texas (United States); Ellis, R. F. [Laboratory for Plasma and Fusion Energy Studies, University of Maryland, College Park, Maryland 20742 (United States)

    2013-10-15

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  12. Study of transmission line attenuation in broad band millimeter wave frequency range.

    Science.gov (United States)

    Pandya, Hitesh Kumar B; Austin, M E; Ellis, R F

    2013-10-01

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  13. Design, calibration and application of broad-range optical nanosensors for determining intracellular pH.

    Science.gov (United States)

    Søndergaard, Rikke V; Henriksen, Jonas R; Andresen, Thomas L

    2014-12-01

    Particle-based nanosensors offer a tool for determining the pH in the endosomal-lysosomal system of living cells. Measurements providing absolute values of pH have so far been restricted by the limited sensitivity range of nanosensors, calibration challenges and the complexity of image analysis. This protocol describes the design and application of a polyacrylamide-based nanosensor (∼60 nm) that covalently incorporates two pH-sensitive fluorophores, fluorescein (FS) and Oregon Green (OG), to broaden the sensitivity range of the sensor (pH 3.1-7.0), and uses the pH-insensitive fluorophore rhodamine as a reference fluorophore. The nanosensors are spontaneously taken up via endocytosis and directed to the lysosomes where dynamic changes in pH can be measured with live-cell confocal microscopy. The most important focus areas of the protocol are the choice of pH-sensitive fluorophores, the design of calibration buffers, the determination of the effective range and especially the description of how to critically evaluate results. The entire procedure typically takes 2-3 weeks.

  14. Design, calibration and application of broad-range optical nanosensors for determining intracellular pH

    DEFF Research Database (Denmark)

    Søndergaard, Rikke Vicki; Henriksen, Jonas Rosager; Andresen, Thomas Lars

    2014-01-01

    as a reference fluorophore. The nanosensors are spontaneously taken up via endocytosis and directed to the lysosomes where dynamic changes in pH can be measured with live-cell confocal microscopy. The most important focus areas of the protocol are the choice of pH-sensitive fluorophores, the design......Particle-based nanosensors offer a tool for determining the pH in the endosomal-lysosomal system of living cells. Measurements providing absolute values of pH have so far been restricted by the limited sensitivity range of nanosensors, calibration challenges and the complexity of image analysis...

  15. Experimental Adaptation of Burkholderia cenocepacia to Onion Medium Reduces Host Range ▿ † ‡

    Science.gov (United States)

    Ellis, Crystal N.; Cooper, Vaughn S.

    2010-01-01

    It is unclear whether adaptation to a new host typically broadens or compromises host range, yet the answer bears on the fate of emergent pathogens and symbionts. We investigated this dynamic using a soil isolate of Burkholderia cenocepacia, a species that normally inhabits the rhizosphere, is related to the onion pathogen B. cepacia, and can infect the lungs of cystic fibrosis patients. We hypothesized that adaptation of B. cenocepacia to a novel host would compromise fitness and virulence in alternative hosts. We modeled adaptation to a specific host by experimentally evolving 12 populations of B. cenocepacia in liquid medium composed of macerated onion tissue for 1,000 generations. The mean fitness of all populations increased by 78% relative to the ancestor, but significant variation among lines was observed. Populations also varied in several phenotypes related to host association, including motility, biofilm formation, and quorum-sensing function. Together, these results suggest that each population adapted by fixing different sets of adaptive mutations. However, this adaptation was consistently accompanied by a loss of pathogenicity to the nematode Caenorhabditis elegans; by 500 generations most populations became unable to kill nematodes. In conclusion, we observed a narrowing of host range as a consequence of prolonged adaptation to an environment simulating a specific host, and we suggest that emergent pathogens may face similar consequences if they become host-restricted. PMID:20154121

  16. A plant virus evolved by acquiring multiple nonconserved genes to extend its host range.

    Science.gov (United States)

    Tatineni, Satyanarayana; Robertson, Cecile J; Garnsey, Stephen M; Dawson, William O

    2011-10-18

    Viruses have evolved as combinations of genes whose products interact with cellular components to produce progeny virus throughout the plants. Some viral genes, particularly those that are involved in replication and assembly, tend to be relatively conserved, whereas other genes that have evolved for interactions with the specific host for movement and to counter host-defense systems tend to be less conserved. Closteroviridae encode 1-5 nonconserved ORFs. Citrus tristeza virus (CTV), a Closterovirus, possesses nonconserved p33, p18, and p13 genes that are expendable for systemic infection of the two laboratory hosts, Citrus macrophylla and Mexican lime. In this study, we show that the extended host range of CTV requires these nonconserved genes. The p33 gene was required to systemically infect sour orange and lemon trees, whereas either the p33 or the p18 gene was sufficient for systemic infection of grapefruit trees and the p33 or the p13 gene was sufficient for systemic infection of calamondin plants. Thus, these three genes are required for systemic infection of the full host range of CTV, but different genes were specific for different hosts. Remarkably, either of two genes was sufficient for infection of some citrus hybrids. These findings suggest that CTV acquired multiple nonconserved genes (p33, p18, and p13) and, as a result, gained the ability to interact with multiple hosts, thus extending its host range during the course of evolution. These results greatly extend the complexity of known virus-plant interactions.

  17. Estimation of the RF Characteristics of Absorbing Materials in Broad RF Frequency Ranges

    CERN Document Server

    Fandos, R

    2008-01-01

    Absorbing materials are very often used in RF applications. Their electromagnetic characteristics (relative permittivity εr, loss tangent tan δ and conductivity σ) are needed in order to obtain a high-quality design of the absorbing pieces in the frequency range of interest. Unfortunately, suppliers often do not provide these quantities. A simple technique to determine them, based on the RF measurement of the disturbance created by the insertion of a piece of absorber in a waveguide, is presented in this note. Results for samples of two different materials, silicon carbide and aluminum nitride are presented. While the former has a negligible conductivity at the working frequencies, the conductivity of the latter has to be taken into account in order to obtain a meaningful estimation of εr and tan δ. The equations of Kramers & Kronig have been applied to the data as a cross check, confirming the results.

  18. A broad pH range and processive chitinase from a metagenome library

    Directory of Open Access Journals (Sweden)

    S.S. Thimoteo

    Full Text Available Chitinases are hydrolases that degrade chitin, a polymer of N-acetylglucosamine linked β(1-4 present in the exoskeleton of crustaceans, insects, nematodes and fungal cell walls. A metagenome fosmid library from a wastewater-contaminated soil was functionally screened for chitinase activity leading to the isolation and identification of a chitinase gene named metachi18A. The metachi18A gene was subcloned and overexpressed in Escherichia coli BL21 and the MetaChi18A chitinase was purified by affinity chromatography as a 6xHis-tagged fusion protein. The MetaChi18A enzyme is a 92-kDa protein with a conserved active site domain of glycosyl hydrolases family 18. It hydrolyses colloidal chitin with an optimum pH of 5 and temperature of 50°C. Moreover, the enzyme retained at least 80% of its activity in the pH range from 4 to 9 and 98% at 600 mM NaCl. Thin layer chromatography analyses identified chitobiose as the main product of MetaChi18A on chitin polymers as substrate. Kinetic analysis showed inhibition of MetaChi18A activity at high concentrations of colloidal chitin and 4-methylumbelliferyl N,N′-diacetylchitobiose and sigmoid kinetics at low concentrations of colloidal chitin, indicating a possible conformational change to lead the chitin chain from the chitin-binding to the catalytic domain. The observed stability and activity of MetaChi18A over a wide range of conditions suggest that this chitinase, now characterized, may be suitable for application in the industrial processing of chitin.

  19. Effect of spectral range in surface inactivation of Listeria innocua using broad-spectrum pulsed light.

    Science.gov (United States)

    Woodling, Sarah E; Moraru, Carmen I

    2007-04-01

    Pulsed light (PL) treatment is an alternative to traditional thermal treatment that has the potential to achieve several log-cycle reductions in the concentration of microorganisms. One issue that is still debated is related to what specifically causes cell death after PL treatments. The main objective of this work was to elucidate which portions of the PL range are responsible for bacterial inactivation. Stainless steel coupons with controlled surface properties were inoculated with a known concentration of Listeria innocua in the stationary growth phase and treated with 1 to 12 pulses of light at a pulse rate of 3 pulses per s and a pulse width of 360 micros. The effects of the full spectrum (lambda = 180 to 1,100 nm) were compared with the effects obtained when only certain regions of UV, visible, and near-infrared light were used. The effectiveness of the treatments was determined in parallel by the standard plate count and most-probable-number techniques. At a fluence of about 6 J/cm(2), the full-spectrum PL treatment resulted in a 4.08-log reduction of L. innocua on a Mill finish surface, the removal of lambda light resulted in no lethal effects on L. innocua. Overwhelmingly, the portions of the PL spectrum responsible for bacterial death are the UV-B and UV-C spectral ranges (X light (lambda > 400 nm). This work provides additional supporting evidence that cell death in PL treatment is due to exposure to UV light. Additionally, it was shown that even a minor modification of the light path or the UV light spectrum in PL treatments can have a significant negative impact on the treatment intensity and effectiveness.

  20. Broad-Range Bacterial Capture from Fluid-Samples: Implications for Amplification-Free Contamination Detection

    Directory of Open Access Journals (Sweden)

    Monika WEBER

    2016-08-01

    Full Text Available Fluid-Screen, Inc. presents a bacterial concentration and filtration method based on dielectrophoresis and alternating current kinetics. Dielectrophoresis has been previously shown to induce particle motion; however, bacterial capture efficiency and reproducibility have consistently been low, reducing its potential for practical applications. In this study, we introduce a novel, patent-pending electrode system optimized to simultaneously capture a wide range of bacterial species from a variety of aqueous solutions. Specifically, we show that the method of dielectrophoresis used induces responses in both characteristic Gram- negative Escherichia coli and Gram-positive Enterococcus faecalis bacteria, as well as with Bacillus subtilis and Aestuariimicrobium kwangyangense. We have adapted the electrode design to create a bacterial sample preparatio unit, termed the sample sorter, that is able to capture multiple bacterial species and release them simultaneously for bacterial concentration and exchange from complex matrices to defined buffer media. This technology can be used on its own or in conjunction with standard bacterial detection methods such as mass spectroscopy. The Fluid-Screen product will dramatically improve testing and identification of bacterial contaminants in various industrial settings by eliminating the need for amplification of samples and by reducing the time to identification.

  1. Numerical Upscaling of Transport Through Obstructed Regions Over a Broad Range of Reynolds Numbers

    Science.gov (United States)

    Sund, N. L.; Bolster, D.; Mattis, S. A.

    2014-12-01

    While historically flow and transport in porous media has focused on low Reynolds number and Peclet number regimes there are a variety of examples relevant to environmental fluid dynamics where higher Reynolds number flows are important. A common example might include flow and transport through wetlands where plants act as the solid phase of an effective porous medium. In particular, heterogeneity in the flow field due to presence of the solid phases gives rise to complex transport and mixing behaviors that cannot be upscaled at pre-asymptotic times using conventional approaches. We numerically simulate pore-scale flow and transport through obstructed domains over a range of Reynolds numbers from 15 to 280 and then upscale transport. We upscale using a correlated continuous time random walk (correlated CTRW) model, originally introduced in [1]. We then assess the correlated CTRW's ability to predict observables for both asymptotic and pre-asymptotic time scales and compare our results to those of a classical CTRW to determine when velocity correlations must be accounted for. REFERENCES[1] T.L. Borgne, M. Dentz, J. Carrera: Lagrangian statistical model for transport in highly heterogeneous velocity fields, Physical Review Letters 101 (2008) 090601.

  2. A plasmid-transposon hybrid mutagenesis system effective in a broad range of Enterobacteria

    Directory of Open Access Journals (Sweden)

    Rita eMonson

    2015-12-01

    Full Text Available Random transposon mutagenesis is a powerful technique used to generate libraries of genetic insertions in many different bacterial strains. Here we develop a system facilitating random transposon mutagenesis in a range of different Gram-negative bacterial strains, including Pectobacterium atrosepticum, Citrobacter rodentium, Serratia sp. ATCC39006, Serratia plymuthica, Dickeya dadantii and many more. Transposon mutagenesis was optimized in each of these strains and three studies are presented to show the efficacy of this system. Firstly, the important agricultural pathogen D. dadantii was mutagenized. Two mutants that showed reduced protease production and one mutant producing the previously cryptic pigment, indigoidine, were identified and characterized. Secondly, the enterobacterium, Serratia sp. ATCC39006 was mutagenized and mutants incapable of producing gas vesicles, proteinaceous intracellular organelles, were identified. One of these contained a β-galactosidase transcriptional fusion within the gene gvpA1, essential for gas vesicle production. Finally, the system was used to mutate the biosynthetic gene clusters of the antifungal, anti-oomycete and anticancer polyketide, oocydin A, in the plant-associated enterobacterium, Dickeya solani MK10. The mutagenesis system was developed to allow easy identification of transposon insertion sites by sequencing, after facile generation of a replicon encompassing the transposon and adjacent DNA, post-excision. Furthermore, the system can also create transcriptional fusions with either β-galactosidase or β-glucuronidase as reporters, and exploits a variety of drug resistance markers so that multiple selectable fusions can be generated in a single strain. This system of various transposons has wide utility and can be combined in many different ways.

  3. SN 2010ay IS A LUMINOUS AND BROAD-LINED TYPE Ic SUPERNOVA WITHIN A LOW-METALLICITY HOST GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, N. E.; Soderberg, A. M.; Foley, R. J.; Chornock, R.; Chomiuk, L.; Berger, E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Valenti, S.; Smartt, S.; Botticella, M. T. [Astrophysics Research Centre, School of Maths and Physics, Queen' s University, Belfast BT7 1NN (United Kingdom); Hurley, K. [Space Sciences Laboratory, University of California Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Barthelmy, S. D.; Gehrels, N.; Cline, T. [NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States); Levesque, E. M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Narayan, G. [Department of Physics, Harvard University, Cambridge, MA 02138 (United States); Briggs, M. S.; Connaughton, V. [CSPAR, University of Alabama in Huntsville, Huntsville, AL (United States); Terada, Y. [Department of Physics, Saitama University, Shimo-Okubo, Sakura-ku, Saitama-shi, Saitama 338-8570 (Japan); Golenetskii, S.; Mazets, E., E-mail: nsanders@cfa.harvard.edu [Ioffe Physico-Technical Institute, Laboratory for Experimental Astrophysics, 26 Polytekhnicheskaya, St. Petersburg 194021 (Russian Federation); and others

    2012-09-10

    We report on our serendipitous pre-discovery detection and follow-up observations of the broad-lined Type Ic supernova (SN Ic) 2010ay at z = 0.067 imaged by the Pan-STARRS1 3{pi} survey just {approx}4 days after explosion. The supernova (SN) had a peak luminosity, M{sub R} Almost-Equal-To -20.2 mag, significantly more luminous than known GRB-SNe and one of the most luminous SNe Ib/c ever discovered. The absorption velocity of SN 2010ay is v{sub Si} Almost-Equal-To 19 Multiplication-Sign 10{sup 3} km s{sup -1} at {approx}40 days after explosion, 2-5 times higher than other broad-lined SNe and similar to the GRB-SN 2010bh at comparable epochs. Moreover, the velocity declines {approx}2 times slower than other SNe Ic-BL and GRB-SNe. Assuming that the optical emission is powered by radioactive decay, the peak magnitude implies the synthesis of an unusually large mass of {sup 56}Ni, M{sub Ni} = 0.9 M{sub Sun }. Applying scaling relations to the light curve, we estimate a total ejecta mass, M{sub ej} Almost-Equal-To 4.7 M{sub Sun }, and total kinetic energy, E{sub K} Almost-Equal-To 11 Multiplication-Sign 10{sup 51} erg. The ratio of M{sub Ni} to M{sub ej} is {approx}2 times as large for SN 2010ay as typical GRB-SNe and may suggest an additional energy reservoir. The metallicity (log (O/H){sub PP04} + 12 = 8.19) of the explosion site within the host galaxy places SN 2010ay in the low-metallicity regime populated by GRB-SNe, and {approx}0.5(0.2) dex lower than that typically measured for the host environments of normal (broad-lined) SNe Ic. We constrain any gamma-ray emission with E{sub {gamma}} {approx}< 6 Multiplication-Sign 10{sup 48} erg (25-150 keV), and our deep radio follow-up observations with the Expanded Very Large Array rule out relativistic ejecta with energy E {approx}> 10{sup 48} erg. We therefore rule out the association of a relativistic outflow like those that accompanied SN 1998bw and traditional long-duration gamma-ray bursts (GRBs), but we place less

  4. A plant virus evolved by acquiring multiple nonconserved genes to extend its host range

    Science.gov (United States)

    Tatineni, Satyanarayana; Robertson, Cecile J.; Garnsey, Stephen M.; Dawson, William O.

    2011-01-01

    Viruses have evolved as combinations of genes whose products interact with cellular components to produce progeny virus throughout the plants. Some viral genes, particularly those that are involved in replication and assembly, tend to be relatively conserved, whereas other genes that have evolved for interactions with the specific host for movement and to counter host–defense systems tend to be less conserved. Closteroviridae encode 1–5 nonconserved ORFs. Citrus tristeza virus (CTV), a Closterovirus, possesses nonconserved p33, p18, and p13 genes that are expendable for systemic infection of the two laboratory hosts, Citrus macrophylla and Mexican lime. In this study, we show that the extended host range of CTV requires these nonconserved genes. The p33 gene was required to systemically infect sour orange and lemon trees, whereas either the p33 or the p18 gene was sufficient for systemic infection of grapefruit trees and the p33 or the p13 gene was sufficient for systemic infection of calamondin plants. Thus, these three genes are required for systemic infection of the full host range of CTV, but different genes were specific for different hosts. Remarkably, either of two genes was sufficient for infection of some citrus hybrids. These findings suggest that CTV acquired multiple nonconserved genes (p33, p18, and p13) and, as a result, gained the ability to interact with multiple hosts, thus extending its host range during the course of evolution. These results greatly extend the complexity of known virus–plant interactions. PMID:21987809

  5. Infection of non-host model plant species with the narrow-host-range Cacao swollen shoot virus.

    Science.gov (United States)

    Friscina, Arianna; Chiappetta, Laura; Jacquemond, Mireille; Tepfer, Mark

    2017-02-01

    Cacao swollen shoot virus (CSSV) is a major pathogen of cacao (Theobroma cacao) in Africa, and long-standing efforts to limit its spread by the culling of infected trees have had very limited success. CSSV is a particularly difficult virus to study, as it has a very narrow host range, limited to several tropical tree species. Furthermore, the virus is not mechanically transmissible, and its insect vector can only be used with difficulty. Thus, the only efficient means to infect cacao plants that have been experimentally described so far are by particle bombardment or the agroinoculation of cacao plants with an infectious clone. We have genetically transformed three non-host species with an infectious form of the CSSV genome: two experimental hosts widely used in plant virology (Nicotiana tabacum and N. benthamiana) and the model species Arabidopsis thaliana. In transformed plants of all three species, the CSSV genome was able to replicate, and, in tobacco, CSSV particles could be observed by immunosorbent electron microscopy, demonstrating that the complete virus cycle could be completed in a non-host plant. These results will greatly facilitate the preliminary testing of CSSV control strategies using plants that are easy to raise and to transform genetically. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  6. Improving the catalytic activity of hyperthermophilic Pyrococcus prolidases for detoxification of organophosphorus nerve agents over a broad range of temperatures.

    Science.gov (United States)

    Theriot, Casey M; Du, Xuelian; Tove, Sherry R; Grunden, Amy M

    2010-08-01

    Prolidase isolated from the hyperthermophilic archaeon Pyrococcus furiosus has potential for application for decontamination of organophosphorus compounds in certain pesticides and chemical warfare agents under harsh conditions. However, current applications that use an enzyme-based cocktail are limited by poor long-term enzyme stability and low reactivity over a broad range of temperatures. To obtain a better enzyme for OP nerve agent decontamination and to investigate structural factors that influence protein thermostability and thermoactivity, randomly mutated P. furiosus prolidases were prepared by using XL1-red-based mutagenesis and error-prone PCR. An Escherichia coli strain JD1 (lambdaDE3) (auxotrophic for proline [DeltaproA] and having deletions in pepQ and pepP dipeptidases with specificity for proline-containing dipeptides) was constructed for screening mutant P. furiosus prolidase expression plasmids. JD1 (lambdaDE3) cells were transformed with mutated prolidase expression plasmids and plated on minimal media supplemented with 50 muM Leu-Pro as the only source of proline. By using this positive selection, Pyrococcus prolidase mutants with improved activity over a broader range of temperatures were isolated. The activities of the mutants over a broad temperature range were measured for both Xaa-Pro dipeptides and OP nerve agents, and the thermoactivity and thermostability of the mutants were determined.

  7. Flexible cross-correlated (C2) imaging method for the modal content characterization in a broad range of wavelengths

    DEFF Research Database (Denmark)

    Muliar, Olena; Usuga Castaneda, Mario A.; Michieletto, Mattia

    2017-01-01

    as the phase distribution are extracted by the alternative method of 2D FT filtering. Being exceptionally tunable the flexible C2 method gives an ability to adapt the system’s parameters in a desired manner satisfying even measurements of very specific fiber designs opening up new possibilities for advanced......We demonstrate a flexible cross-correlated (C2) imaging method in the time domain by application of a tunable and highly flexible light source. An advantage of the flexible C2method is shown by characterization of the step-index fiber (SMF28) over a broad range of wavelengths from 870nm to 1090nm...

  8. DNRA and denitrification coexist over a broad range of acetate/N-NO3- ratios, in a chemostat enrichment culture

    Directory of Open Access Journals (Sweden)

    Eveline Maria Van Den Berg

    2016-11-01

    Full Text Available Denitrification and dissimilatory nitrate reduction to ammonium (DNRA compete for nitrate in natural and engineered environments. A known important factor in this microbial competition is the ratio of available electron donor and elector acceptor, here expressed as Ac/N ratio (acetate/nitrate-nitrogen. We studied the impact of the Ac/N ratio on the nitrate reduction pathways in chemostat enrichment cultures, grown on acetate mineral medium. Stepwise, conditions were changed from nitrate limitation to nitrate excess in the system by applying a variable Ac/N ratio in the feed. We observed a clear correlation between Ac/N ratio and DNRA activity and the DNRA population in our reactor. The DNRA bacteria dominated under nitrate limiting conditions in the reactor and were outcompeted by denitrifiers under limitation of acetate. Interestingly, in a broad range of Ac/N ratios a dual limitation of acetate and nitrate occurred with co-occurrence of DNRA bacteria and denitrifiers. To explain these observations, the system was described using a kinetic model. The model illustrates that the Ac/N effect and concomitant broad dual limitation range related to the difference in stoichiometry between both processes, as well as the differences in electron donor and acceptor affinities. Population analysis showed that the presumed DRNA-performing bacteria were the same under nitrate limitation and under dual limiting conditions, whereas the presumed denitrifying population changed under single and dual limitation conditions.

  9. Single-ion polymer electrolyte membranes enable lithium-ion batteries with a broad operating temperature range.

    Science.gov (United States)

    Cai, Weiwei; Zhang, Yunfeng; Li, Jing; Sun, Yubao; Cheng, Hansong

    2014-04-01

    Conductive processes involving lithium ions are analyzed in detail from a mechanistic perspective, and demonstrate that single ion polymeric electrolyte (SIPE) membranes can be used in lithium-ion batteries with a wide operating temperature range (25-80 °C) through systematic optimization of electrodes and electrode/electrolyte interfaces, in sharp contrast to other batteries equipped with SIPE membranes that display appreciable operability only at elevated temperatures (>60 °C). The performance is comparable to that of batteries using liquid electrolyte of inorganic salt, and the batteries exhibit excellent cycle life and rate performance. This significant widening of battery operation temperatures coupled with the inherent flexibility and robustness of the SIPE membranes makes it possible to develop thin and flexible Li-ion batteries for a broad range of applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The role of cell signaling in poxvirus tropism: the case of the M-T5 host range protein of myxoma virus.

    Science.gov (United States)

    Werden, Steven J; McFadden, Grant

    2008-01-01

    Poxviruses demonstrate strict species specificity in vivo that range from narrow to broad, however the fundamental factors that mediate the basis of poxvirus tropism remain poorly understood. It is generally believed that most, if not all, poxviruses can efficiently bind and enter a wide range of mammalian cells and all of the known host anti-viral pathways that block viral replication in nonpremissive cells operate downstream of virus entry. A productive poxvirus infection is heavily dependent upon the production of a vast array of host modulatory products that specifically target and manipulate both extracellular immune response pathways of the host, as well as intracellular signal transduction pathways of the individually infected cells. The unique pathogenesis and host tropism of specific poxviruses can be attributed to the broad diversity of host modulatory proteins they express. Myxoma virus (MV) is a rabbit-specific poxviruses that encodes multiple host range factors, including an ankyrin-repeat protein M-T5, which functions to regulate tropism of MV for rabbit lymphocytes and some human cancer cells. At the molecular level, M-T5 binds and alters at least two distinct cellular proteins: Akt and cullin-1. The direct interaction between M-T5 and Akt was shown to be a key restriction determinant for MV tropism in a spectrum of human cancer cells making MV an excellent oncolytic candidate. Thus, the intricate relationship between viral encoded proteins and components of the host cell signaling networks can have profound impact on poxvirus tropism. The lessons we continue to learn from poxvirus host range factors like M-T5 will provide further insights into the factors that regulate poxvirus tropism and the mechanisms by which poxviruses micromanipulate the signaling pathways of the infected cell.

  11. Hybridization between two cestode species and its consequences for intermediate host range

    Directory of Open Access Journals (Sweden)

    Henrich Tina

    2013-02-01

    Full Text Available Abstract Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii, both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively. Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  12. Hybridization between two cestode species and its consequences for intermediate host range.

    Science.gov (United States)

    Henrich, Tina; Benesh, Daniel P; Kalbe, Martin

    2013-02-07

    Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F(1) hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii), both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively). We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  13. Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts.

    Directory of Open Access Journals (Sweden)

    Luciana de Lima Ferreira

    Full Text Available Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts.

  14. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments.

    Science.gov (United States)

    Zhang, M; Søndergaard, R V; Kumar, E K P; Henriksen, J R; Cui, D; Hammershøj, P; Clausen, M H; Andresen, T L

    2015-11-07

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements of acidic intracellular pH (pH pH 1.4 to 7.0. In this nanosensor, three pH-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured without being too close to the limits of its pH-range. The nanosensor exhibits no susceptibility to interference by other intracellular ions at physiological concentrations. Due to its positive surface charge it is spontaneously internalized by HeLa cells and localizes to the lysosomes where the mean pH was measured at 4.6. This quadruple-labelled nanosensor performs accurate measurements of fluctuations of lysosomal pH in both directions, which was shown by treatment with the V-ATPase inhibitor bafilomycin A1 or its substrate ATP in HeLa cells. These measurements indicate that this novel quadruple-labelled nanosensor is a promising new tool for measuring the pH of acidic compartments in living cells.

  15. Abundance and local range of broad-snouted caiman (Caiman latirostris, Alligatoridae in the northwest of Santa Catarina Island

    Directory of Open Access Journals (Sweden)

    Walfrido Moraes Tomás

    2008-12-01

    Full Text Available This is the first report on the distribution and relative abundance of the broad-snouted caiman on Santa Catarina Island. The study estimated the relative abundance of caiman along the rivers at Estação Ecológica de Carijós, in addition to evaluating the occurrence of this species in the entire area of the Ratones River plain on the northwestern portion of the island. The mean relative abundance obtained by nocturnal counts was 0.25 (±0.07 caiman/km surveyed. There was a weak correlation between the number of caimans and the air temperature. Based on interviews with the local community and nocturnal surveys of caimans in rivers and reservoirs surrounding the protected area, we concluded that the range occupied by caimans covered the entire area of the Ratones river plain, inhabiting natural habitats (rivers, mangroves, swamps as well as artificial habitats (reservoirs and water channels. Although this study provides basic information about the broad-snouted caiman population on this part of the island, it is aimed mainly at providing guidance for future research.

  16. Fundamental host range of Leptoypha hospita (Hemiptera: Tingidae), a potential biological control agent of Chinese privet

    Science.gov (United States)

    Yanzhuo Zhang; James L. Hanula; Scott Horn; Cera Jones; S. Kristine Braman; Jianghua Sun

    2016-01-01

    Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et...

  17. The host range of Aspergillus niger and Fusarium oxysporum in the ...

    African Journals Online (AJOL)

    A study was carried out to determine the host range of two fungal organisms, Fusarium oxysporum, the cause of vegetable root rots and Aspergillus niger, the black mold organism, among the members of the family Solanaceae. The test crops were tomato (Lycopersicon esculentum), pepper (Capsicum annuum), potato ...

  18. Plant host range of Verticillium longisporum and microsclerotia density in Swedisch soils

    NARCIS (Netherlands)

    Johansson, A.; Goud, J.C.; Dixelius, C.

    2006-01-01

    Verticillium longisporum is a soil-borne fungal pathogen causing vascular wilt of Brassica crops. This study was conducted to enhance our knowledge on the host range of V. longisporum. Seven crop species (barley, oat, oilseed rape, pea, red clover, sugar beet and wheat) and five weed species (barren

  19. Evolution of specialization: a phylogenetic study of host range in the red milkweed beetle (Tetraopes tetraophthalmus).

    Science.gov (United States)

    Rasmann, Sergio; Agrawal, Anurag A

    2011-06-01

    Specialization is common in most lineages of insect herbivores, one of the most diverse groups of organisms on earth. To address how and why specialization is maintained over evolutionary time, we hypothesized that plant defense and other ecological attributes of potential host plants would predict the performance of a specialist root-feeding herbivore (the red milkweed beetle, Tetraopes tetraophthalmus). Using a comparative phylogenetic and functional trait approach, we assessed the determinants of insect host range across 18 species of Asclepias. Larval survivorship decreased with increasing phylogenetic distance from the true host, Asclepias syriaca, suggesting that adaptation to plant traits drives specialization. Among several root traits measured, only cardenolides (toxic defense chemicals) correlated with larval survival, and cardenolides also explained the phylogenetic distance effect in phylogenetically controlled multiple regression analyses. Additionally, milkweed species having a known association with other Tetraopes beetles were better hosts than species lacking Tetraopes herbivores, and milkweeds with specific leaf area values (a trait related to leaf function and habitat affiliation) similar to those of A. syriaca were better hosts than species having divergent values. We thus conclude that phylogenetic distance is an integrated measure of phenotypic and ecological attributes of Asclepias species, especially defensive cardenolides, which can be used to explain specialization and constraints on host shifts over evolutionary time.

  20. Development of photonic-crystal-fiber-based optical coupler with a broad operating wavelength range of 800 nm

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Min-Seok; Kwon, Oh-Jang; Kim, Hyun-Joo; Chu, Su-Ho; Kim, Gil-Hwan; Lee, Sang-Bae; Han, Young-Geun [Hanyang University, Seoul (Korea, Republic of)

    2010-12-15

    We developed a broadband optical coupler based on a photonic crystal fiber (PCF), which is very useful for applications to optical coherence tomography (OCT). The PCF-based coupler is fabricated by using a fused biconical tapering (FBT) method. The PCF has six hexagonally-stacked layers of air holes. The PCF-based coupler has a nearly-flat 50/50 coupling ratio in a broad bandwidth range of 800 nm, which is much wider than that previously reported for a PCF-based coupler and a singlemode-fiber-based coupler. The bandwidth and the bandedge wavelength of the broadband coupler are controlled by changing the elongation length. The fabricated broadband optical coupler has great potential for realizing a broadband interferogram with a high resolution in an OCT system.

  1. Expansion of host range as a driving force in the evolution of Toxoplasma

    Directory of Open Access Journals (Sweden)

    John C Boothroyd

    2009-03-01

    Full Text Available The apicomplexan parasite Toxoplasma gondii is unusual in being able to infect almost any cell from almost any warm-blooded animal it encounters. This extraordinary host-range contrasts with its far more particular cousins such as the various species of the malaria parasite Plasmodium where each species of parasite has a single genus or even species of host that it can infect. Genetic and genomic studies have revealed a key role for a number of gene families in how Toxoplasma invades a host cell, modulates gene expression of that cell and successfully evades the resulting immune response. In this review, I will explore the hypothesis that a combination of sexual recombination and expansion of host range may be the major driving forces in the evolution of some of these gene families and the specific genes they encompass. These ideas stem from results and thoughts published by several labs in the last few years but especially recent papers on the role of different forms of rhoptry proteins in the relative virulence of F1 Toxoplasma progeny in a particular host species (mice.

  2. First survey on ecological host range of aphid pathogenic fungi (Phylum Entomophthoromycota) in Tunisia

    DEFF Research Database (Denmark)

    Ben Fekih, Ibtissem; Boukhris-Bouhachem, Sonia; Allagui, Mohamed Bechir

    2015-01-01

    Summary. The natural occurrence of fungal pathogens of aphids and their ecological host range was investigated in Tunisia from 2009 to 2012. The survey focused on aphid infesting different crops and weeds and included 10 different aphid species. Samples were collected from eight agricultural crops...... (Entomophthorales: Ancylistaceae) and Neozygites fresenii (Neozygitales: Neozygitaceae). The occurrence of entomophthoralean fungi depended on the sampling area, the bioclimatic zone, and aphid species. P. neoaphidis and E. planchoniana were the predominant pathogens infecting a wide range of aphid species whereas...... C. obscurus and N. fresenii were sporadically present on a limited number of aphid species. This study is the first survey on ecological host range of entomophthoralean fungi in Tunisia, and the first documentation of C. obscurus and N. fresenii to occur in Tunisia and Maghreb Region....

  3. The Fleas (Siphonaptera in Iran: Diversity, Host Range, and Medical Importance.

    Directory of Open Access Journals (Sweden)

    Naseh Maleki-Ravasan

    2017-01-01

    Full Text Available Flea-borne diseases have a wide distribution in the world. Studies on the identity, abundance, distribution and seasonality of the potential vectors of pathogenic agents (e.g. Yersinia pestis, Francisella tularensis, and Rickettsia felis are necessary tools for controlling and preventing such diseases outbreaks. The improvements of diagnostic tools are partly responsible for an easier detection of otherwise unnoticed agents in the ectoparasitic fauna and as such a good taxonomical knowledge of the potential vectors is crucial. The aims of this study were to make an exhaustive inventory of the literature on the fleas (Siphonaptera and range of associated hosts in Iran, present their known distribution, and discuss their medical importance.The data were obtained by an extensive literature review related to medically significant fleas in Iran published before 31st August 2016. The flea-host specificity was then determined using a family and subfamily-oriented criteria to further realize and quantify the shared and exclusive vertebrate hosts of fleas among Iran fleas. The locations sampled and reported in the literature were primarily from human habitation, livestock farms, poultry, and rodents' burrows of the 31 provinces of the country. The flea fauna were dominated by seven families, namely the Ceratophyllidae, Leptopsyllidae, Pulicidae, Ctenophthalmidae, Coptopsyllidae, Ischnopsyllidae and Vermipsyllidae. The hosts associated with Iran fleas ranged from the small and large mammals to the birds. Pulicidae were associated with 73% (56/77 of identified host species. Flea-host association analysis indicates that rodents are the common hosts of 5 flea families but some sampling bias results in the reduced number of bird host sampled. Analyses of flea-host relationships at the subfamily level showed that most vertebrates hosted fleas belgonging to 3 subfamilies namely Xenopsyllinae (n = 43, Ctenophthalminae (n = 20 and Amphipsyllinae (n = 17. Meriones

  4. Ultra-broad range organic solid-state laser from a dye-doped holographic grating quasi-waveguide configuration

    Science.gov (United States)

    Liu, Minghuan; Liu, Yonggang; Peng, Zenghui; Mu, Quanquan; Cao, Zhaoliang; Lu, Xinghai; Ma, Ji; Xuan, Li

    2017-08-01

    This paper reports the ultra-broad 149.1 nm lasing emission from 573.2 to 722.3 nm using a simple [4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran] (DCM)-doped holographic polymer-dispersed liquid crystal (HPDLC) grating quasi-waveguide configuration by varying the grating period. The lasing emission beams show s-polarization property. The quasi-waveguide structure, which contained the cover glass, the DCM-doped HPDLC grating, the semiconducting polymer film poly[-methoxy-5-(2‧-ethyl-hexyloxy)-1,4-phenylene-vinylene] (MEH-PPV), and the substrate were confirmed to decrease lasing threshold and broaden lasing wavelength. The operational lifetime of the device is 240 000 pulses, which corresponds to an overall laser duration of more than 6 h at a repetition rate of 10 Hz. In addition, the dual-wavelength lasing range from the 8th and 9th order is over 40 nm. The electrical tunability of the dual-wavelength lasing emission is over 1 nm. The experimental results facilitated the decreased lasing threshold and broadened lasing wavelength range of organic solid-state lasers.

  5. High energy storage density over a broad temperature range in sodium bismuth titanate-based lead-free ceramics.

    Science.gov (United States)

    Yang, Haibo; Yan, Fei; Lin, Ying; Wang, Tong; Wang, Fen

    2017-08-18

    A series of (1-x)Bi0.48La0.02Na0.48Li0.02Ti0.98Zr0.02O3-xNa0.73Bi0.09NbO3 ((1-x)LLBNTZ-xNBN) (x = 0-0.14) ceramics were designed and fabricated using the conventional solid-state sintering method. The phase structure, microstructure, dielectric, ferroelectric and energy storage properties of the ceramics were systematically investigated. The results indicate that the addition of Na0.73Bi0.09NbO3 (NBN) could decrease the remnant polarization (P r ) and improve the temperature stability of dielectric constant obviously. The working temperature range satisfying TCC 150 °C ≤±15% of this work spans over 400 °C with the compositions of x ≥ 0.06. The maximum energy storage density can be obtained for the sample with x = 0.10 at room temperature, with an energy storage density of 2.04 J/cm(3) at 178 kV/cm. In addition, the (1-x)LLBNTZ-xNBN ceramics exhibit excellent energy storage properties over a wide temperature range from room temperature to 90 °C. The values of energy storage density and energy storage efficiency is 0.91 J/cm(3) and 79.51%, respectively, for the 0.90LLBNTZ-0.10NBN ceramic at the condition of 100 kV/cm and 90 °C. It can be concluded that the (1-x)LLBNTZ-xNBN ceramics are promising lead-free candidate materials for energy storage devices over a broad temperature range.

  6. Morphology and possible host range of Rhizophydium algavorum sp. Nov.. (Chytridiales) an obligate parasite of algae

    OpenAIRE

    Gromov, B.; Plujusch, A.; Mamkaeva, K.

    1999-01-01

    Culture of Rhizophydium (Chytridiales) was isolated from a little pond near St.-Petersburg and described as representative of a new species Rh. algavorum. It is an obligate parasite of algae with a very wide possible host range. From 137 strains of chlorococcalean algae examined 33 are sensitive, they represent 20 species of 5 genera. Xanthophycean alga Tribonema gayanum is sensitive as well. Parasite forms sessile sphaerical sporangia. Zoospores escape from the sporangium upon the single wid...

  7. Broad-Range Detection of Microorganisms Directly from Bronchoalveolar Lavage Specimens by PCR/Electrospray Ionization-Mass Spectrometry

    Science.gov (United States)

    Ullberg, Måns; Lüthje, Petra; Mölling, Paula; Strålin, Kristoffer

    2017-01-01

    The clinical demand on rapid microbiological diagnostic is constantly increasing. PCR coupled to electrospray ionization-mass spectrometry, PCR/ESI-MS, offers detection and identification of over 750 bacteria and Candida species directly from clinical specimens within 6 hours. In this study, we investigated the clinical performance of the IRIDICA BAC LRT Assay for detection of bacterial pathogens in 121 bronchoalveolar lavage (BAL) samples that were received consecutively at our bacterial laboratory for BAL culture. Commensal or pathogenic microorganisms were detected in 118/121 (98%) BAL samples by PCR/ESI-MS, while in 104/121 (86%) samples by routine culture (PPCR/ESI-MS was evaluated in comparison with conventional culture-based or molecular methods. The agreement between positive findings was overall good. Most Staphylococcus aureus-positive PCR/ESI-MS results were confirmed by culture or species-specific PCR (27/33, 82%). The identity of Streptococcus pneumoniae could however be confirmed for only 6/17 (35%) PCR/ESI-MS-positive samples. Non-cultivable and fastidious pathogens, which were not covered by standard culture procedures were readily detected by PCR/ESI-MS, including Legionella pneumophila, Bordetella pertussis, Norcadia species and Mycoplasma pneumoniae. In conclusion, PCR/ESI-MS detected a broad range of potential pathogens with equal or superior sensitivity compared to conventional methods within few hours directly from BAL samples. This novel method might thus provide a relevant tool for diagnostics in critically ill patients. PMID:28085931

  8. Broad-Range Electrically Tunable Plasmonic Resonances of a Multilayer Coaxial Nanohole Array with an Electroactive Polymer Wrapper.

    Science.gov (United States)

    Zhou, Ziwei; Yu, Ye; Sun, Ningwei; Möhwald, Helmuth; Gu, Panpan; Wang, Liyan; Zhang, Wei; König, Tobias A F; Fery, Andreas; Zhang, Gang

    2017-10-11

    Plasmonic assemblies featuring high sensitivity that can be readily shifted by external fields are the key for sensitive and versatile sensing devices. In this paper, a novel fast-responsive plasmonic nanocomposite composed of a multilayer nanohole array and a responsive electrochromic polymer is proposed with the plasmonic mode appearance vigorously cycled upon orthogonal electrical stimuli. In this nanocomposite, the coaxially stacked plasmonic nanohole arrays can induce multiple intense Fano resonances, which result from the crosstalk between a broad surface plasmon resonance (SPR) and the designed discrete transmission peaks with ultrahigh sensitivity; the polymer wrapper could provide the sensitive nanohole array with real-time-varied surroundings of refractive indices upon electrical stimuli. Therefore, a pronounced pure electroplasmonic shift up to 72 nm is obtained, which is the largest pure electrotuning SPR range to our knowledge. The stacked nanohole arrays here are also directly used as a working electrode, and they ensure sufficient contact between the working electrode (plasmonic structure) and the electroactive polymer, thus providing considerably improved response speed (within 1 s) for real-time sensing and switching.

  9. Sterility Testing of Stem Cell Products by Broad-Range Bacterial 16S Ribosomal DNA Polymerase Chain Reaction.

    Science.gov (United States)

    Tokuno, Osamu; Hayakawa, Akira; Yanai, Tomoko; Mori, Takeshi; Ohnuma, Kenichiro; Tani, Ayumi; Minami, Hironobu; Sugimoto, Takeshi

    2015-01-01

    To evaluate broad-range 16S ribosomal DNA (rDNA) polymerase chain reaction (PCR) as a rapid screening tool to detect bacterial contamination of stem-cell products. We performed the evaluation using whole blood spiked with serially diluted bacterial-type strains. Detection sensitivity was defined as the bacterial concentration for which all replicates were positive at each concentration (100% detection). We tested the sterility of 29 bags of autologous peripheral blood stem cell (PBSC) products harvested at our facility using the 16S rDNA PCR method. The detection sensitivity of 16S rDNA PCR in spiked whole blood was 10¹ to 10² colony-forming units (CFU) per mL, depending on the bacterial strain. We detected no amplified 16S rDNA among the PBSCs we used in this study. The BacT/ALERT automated bacterial culture system that we used also showed no positive signals in any of the PBSCs tested. Our data indicate that bacterial 16S rDNA PCR is a useful alternative for rapid sterility testing, not only for blood products used in transfusion medicine but also for stem-cell products used in regenerative medicine. Copyright© by the American Society for Clinical Pathology (ASCP).

  10. Broad-band Fourier transform spectroradiometer for the characterisation of atmospheric emission in the far infrared spectral range

    Science.gov (United States)

    Palchetti, L.; Bianchini, G.; Esposito, F.

    A spectroradiometer has been developed for the characterisation of the atmospheric emission in the 100-1100 cm-1 spectral range with a resolution of 0.5 cm-1 and a signal-to-noise ratio of 100. This instrument has been studied in the framework of the REFIR (Radiation Explorer in the Far InfraRed) space project, which addresses the need for new data in a range not yet covered by any current or planned space mission for improving our knowledge of the distribution of the atmospheric components that modulate the Earh's emission, such as mid and upper tropospheric water vapour and clouds. The spectroradiometer is a based on a Fourier transform polarising interferometer with a new optical scheme that makes use of four polarising beam splitters and room-temperature pyroelectric detectors. It provides all the desired features including broad spectral coverage, two separated input ports and two output ports, optical compensation for tilt errors in the moving mirror unit, measurement of the overall input signal (both planes of polarization) on the same detector. This optical configuration maximizes the reliability of the spectrometer in particular for long lifetime space operations or for field campaigns and optimizes its performances with room temperature operations. The spectroradiometer is a compact instrument designed both for laboratory applications and for field campaings. In particular it has been designed for operations in high-altitude ground-based campaigns and on a stratospheric balloon platform. This work describes the design and fabrication of this instrument, the results of the spectroscopic characterisation performed in laboratory conditions and under vacuum, and possibly the first tests on atmospheric measurements scheduled for the beginning of 2004 in the South of Italy.

  11. LysM domains mediate lipochitin-oligosaccharide recognition and Nfr genes extend the symbiotic host range

    DEFF Research Database (Denmark)

    Radutoiu, Simona; Madsen, Lene H; Madsen, Esben B

    2007-01-01

    Legume-Rhizobium symbiosis is an example of selective cell recognition controlled by host/non-host determinants. Individual bacterial strains have a distinct host range enabling nodulation of a limited set of legume species and vice versa. We show here that expression of Lotus japonicus Nfr1...

  12. Prediction of steps in the evolution of variola virus host range.

    Directory of Open Access Journals (Sweden)

    Chad Smithson

    Full Text Available Variola virus, the agent of smallpox, has a severely restricted host range (humans but a devastatingly high mortality rate. Although smallpox has been eradicated by a World Health Organization vaccination program, knowledge of the evolutionary processes by which human super-pathogens such as variola virus arise is important. By analyzing the evolution of variola and other closely related poxviruses at the level of single nucleotide polymorphisms we detected a hotspot of genome variation within the smallpox ortholog of the vaccinia virus O1L gene, which is known to be necessary for efficient replication of vaccinia virus in human cells. These mutations in the variola virus ortholog and the subsequent loss of the functional gene from camelpox virus and taterapox virus, the two closest relatives of variola virus, strongly suggest that changes within this region of the genome may have played a key role in the switch to humans as a host for the ancestral virus and the subsequent host-range restriction that must have occurred to create the phenotype exhibited by smallpox.

  13. Host-Range Dynamics of Cochliobolus lunatus: From a Biocontrol Agent to a Severe Environmental Threat

    Directory of Open Access Journals (Sweden)

    Bengyella Louis

    2014-01-01

    Full Text Available We undertook an investigation to advance understanding of the host-range dynamics and biocontrol implications of Cochliobolus lunatus in the past decade. Potato (Solanum tuberosum L farms were routinely surveyed for brown-to-black leaf spot disease caused by C. lunatus. A biphasic gene data set was assembled and databases were mined for reported hosts of C. lunatus in the last decade. The placement of five virulent strains of C. lunatus causing foliar necrosis of potato was studied with microscopic and phylogenetic tools. Analysis of morphology showed intraspecific variations in stromatic tissues among the virulent strains causing foliar necrosis of potato. A maximum likelihood inference based on GPDH locus separated C. lunatus strains into subclusters and revealed the emergence of unclustered strains. The evolving nutritional requirement of C. lunatus in the last decade is exhibited by the invasion of vertebrates, invertebrates, dicots, and monocots. Our results contribute towards a better understanding of the host-range dynamics of C. lunatus and provide useful implications on the threat posed to the environment when C. lunatus is used as a mycoherbicide.

  14. Detection and Host Range Study of Virus Associated with Pepper Yellow Leaf Curl Disease

    Directory of Open Access Journals (Sweden)

    SRI SULANDARI

    2006-03-01

    Full Text Available High incidence of Pepper yellow leaf curl virus (PepYLCV was observed in Indonesia since early 2000. Disease incidence in Yogyakarta, Central and West Java reached 100% on Capsicum frutescens, but only 10-35% on C. annuum. As an exception, the disease incidence on C. annuum cv. TM 999 was in the range of 70-100%. The causal agent of the disease, PepYLCV, was detected by polymerase chain reaction. Viral specific DNA fragment of the size ~1600 bp and ~550 bp was amplified from infected plants using two pairs of geminivirus universal primers pAL1v1978/pAL1c715, and pAv494/pAc1048, respectively. The PepYLCV has an intermediate host range including plants belonging to the family of Solanaceae, Leguminosae, and Compositae. The species belonging to the families of Cucurbitaceae, Malvaceae, Chenopodiaceae, and Amaranthaceae were resistant to the virus. Physalis floridana, is very prospective as a propagation host for the geminivirus infecting pepper. Nicotiana spp., cucumber, watermelon, cotton, and Sida sp. could be used as a differential host. Besides, Capsicum frutescens cv. Cakra, tomato, N. benthamiana, N. glutinosa, and Ageratum conyzoides could be used as indicator plants for the geminivirus infecting pepper.

  15. Secreted effectors in Toxoplasma gondii and related species: determinants of host range and pathogenesis?

    Science.gov (United States)

    English, E D; Adomako-Ankomah, Y; Boyle, J P

    2015-01-01

    Recent years have witnessed the discovery of a number of secreted proteins in Toxoplasma gondii that play important roles in host–pathogen interactions and parasite virulence, particularly in the mouse model. However, the role that these proteins play in driving the unique features of T. gondii compared to some of its nearest apicomplexan relatives (Hammondia hammondi and Neospora caninum) is unknown. These unique features include distinct dissemination characteristics in vivo and a vast host range. In this review we comprehensively survey what is known about disease outcome, the host response and host range for T. gondii, H. hammondi, and N. caninum. We then review what is presently known about recently identified secreted virulence effectors in these three genetically related, but phenotypically distinct, species. Finally we exploit the existence of genome sequences for these three organisms and discuss what is known about the presence, and functionality, of key T. gondii effectors in these three species. PMID:25655311

  16. Broad-Range Detection of Microorganisms Directly from Bronchoalveolar Lavage Specimens by PCR/Electrospray Ionization-Mass Spectrometry.

    Directory of Open Access Journals (Sweden)

    Måns Ullberg

    Full Text Available The clinical demand on rapid microbiological diagnostic is constantly increasing. PCR coupled to electrospray ionization-mass spectrometry, PCR/ESI-MS, offers detection and identification of over 750 bacteria and Candida species directly from clinical specimens within 6 hours. In this study, we investigated the clinical performance of the IRIDICA BAC LRT Assay for detection of bacterial pathogens in 121 bronchoalveolar lavage (BAL samples that were received consecutively at our bacterial laboratory for BAL culture. Commensal or pathogenic microorganisms were detected in 118/121 (98% BAL samples by PCR/ESI-MS, while in 104/121 (86% samples by routine culture (P<0.01. Detection of potentially pathogenic microorganisms by PCR/ESI-MS was evaluated in comparison with conventional culture-based or molecular methods. The agreement between positive findings was overall good. Most Staphylococcus aureus-positive PCR/ESI-MS results were confirmed by culture or species-specific PCR (27/33, 82%. The identity of Streptococcus pneumoniae could however be confirmed for only 6/17 (35% PCR/ESI-MS-positive samples. Non-cultivable and fastidious pathogens, which were not covered by standard culture procedures were readily detected by PCR/ESI-MS, including Legionella pneumophila, Bordetella pertussis, Norcadia species and Mycoplasma pneumoniae. In conclusion, PCR/ESI-MS detected a broad range of potential pathogens with equal or superior sensitivity compared to conventional methods within few hours directly from BAL samples. This novel method might thus provide a relevant tool for diagnostics in critically ill patients.

  17. The broad-spectrum antiviral compound ST-669 restricts chlamydial inclusion development and bacterial growth and localizes to host cell lipid droplets within treated cells.

    Science.gov (United States)

    Sandoz, Kelsi M; Valiant, William G; Eriksen, Steven G; Hruby, Dennis E; Allen, Robert D; Rockey, Daniel D

    2014-07-01

    Novel broad-spectrum antimicrobials are a critical component of a strategy for combating antibiotic-resistant pathogens. In this study, we explored the activity of the broad-spectrum antiviral compound ST-669 for activity against different intracellular bacteria and began a characterization of its mechanism of antimicrobial action. ST-669 inhibits the growth of three different species of chlamydia and the intracellular bacterium Coxiella burnetii in Vero and HeLa cells but not in McCoy (murine) cells. The antichlamydial and anti-C. burnetii activity spectrum was consistent with those observed for tested viruses, suggesting a common mechanism of action. Cycloheximide treatment in the presence of ST-669 abrogated the inhibitory effect, demonstrating that eukaryotic protein synthesis is required for tested activity. Immunofluorescence microscopy demonstrated that different chlamydiae grow atypically in the presence of ST-669, in a manner that suggests the compound affects inclusion formation and organization. Microscopic analysis of cells treated with a fluorescent derivative of ST-669 demonstrated that the compound localized to host cell lipid droplets but not to other organelles or the host cytosol. These results demonstrate that ST-669 affects intracellular growth in a host-cell-dependent manner and interrupts proper development of chlamydial inclusions, possibly through a lipid droplet-dependent process. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Host Range Restriction of Insect-Specific Flaviviruses Occurs at Several Levels of the Viral Life Cycle

    OpenAIRE

    Sandra Junglen; Marvin Korries; Wolfgang Grasse; Janett Wieseler; Anne Kopp; Kyra Hermanns; Moises León-Juóárez; Christian Drosten; Beate Mareike Kummerer; Glenn Randall

    2017-01-01

    ABSTRACT The genus Flavivirus contains emerging arthropod-borne viruses (arboviruses) infecting vertebrates, as well as insect-specific viruses (ISVs) (i.e., viruses whose host range is restricted to insects). ISVs are evolutionary precursors to arboviruses. Knowledge of the nature of the ISV infection block in vertebrates could identify functions necessary for the expansion of the host range toward vertebrates. Mapping of host restrictions by complementation of ISV and arbovirus genome funct...

  19. Identification of host range mutants of myxoma virus with altered oncolytic potential in human glioma cells.

    Science.gov (United States)

    Barrett, John W; Alston, Lindsay R; Wang, Fuan; Stanford, Marianne M; Gilbert, Philippe-Alexandre; Gao, Xiujuan; Jimenez, June; Villeneuve, Danielle; Forsyth, Peter; McFadden, Grant

    2007-12-01

    The authors have recently demonstrated that wild-type myxoma virus (MV) tagged with gfp (vMyxgfp) can generate a tumor-specific infection that productively infects and clears human tumor-derived xenografts when injected intratumorally into human gliomas transplanted into immunodeficient mice (Lun et al, 2005). To expand the understanding of MV tropism in cancer cells from a specific tissue lineage, the authors have screened a series of human glioma cells (U87, U118, U251, U343, U373) for myxoma virus replication and oncolysis. To assess the viral tropism determinants for these infections, the authors have screened myxoma virus knockout constructs that have been deleted for specific host range genes (M-T2, M-T4, M-T5, M11L, and M063), as well as a control MV gene knockout construct with no known host range function (vMyx135KO) but is highly attenuated in rabbits. The authors report wide variation in the ability of various vMyx-hrKOs to replicate and spread in the human glioma cells as measured by early and late viral gene expression. This differential ability to support vMyx-hrKO productive viral replication is consistent with levels of endogenous activated Akt in the various gliomas. The authors have identified one vMyx-hrKO virus (vMyx63KO) and one nonhost range knockout construct (vMyx135KO) that appear to replicate in the gliomas even more efficiently than the wild-type virus and that reduce the viability of the infected gliomas. These knockout viruses also inhibit the proliferation of gliomas in a manner similar to the wild-type virus. Together these data, as well as the fact that these knockout viruses are attenuated in their natural hosts, may represent environmentally safer candidate oncolytic viruses for usage in human trials.

  20. Host Range Specificity of Scymnus camptodromus (Coleoptera: Coccinellidae), A Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae).

    Science.gov (United States)

    Limbu, Samita; Cassidy, Katie; Keena, Melody; Tobin, Patrick; Hoover, Kelli

    2016-02-01

    Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) was brought to the United States from China as a potential biological control agent for hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae). Scymnus camptodromus phenology is closely synchronized with that of A. tsugae and has several characteristics of a promising biological control agent. As a prerequisite to field release, S. camptodromus was evaluated for potential nontarget impacts. In host range studies, the predator was given the choice of sympatric adelgid and nonadelgid prey items. Nontarget testing showed that S. camptodromus will feed to some degree on other adelgid species, but highly prefers A. tsugae. We also evaluated larval development of S. camptodromus on pine bark adelgid (Pineus strobi (Hartig)) (Hemiptera: Adelgidae) and larch adelgid (Adelges laricis Vallot) (Hemiptera: Adelgidae); a small proportion of predator larvae was able to develop to adulthood on P. strobi or A. laricis alone. Scymnus camptodromus showed no interest in feeding on woolly alder aphid (Paraprociphilus tessellatus Fitch) (Hemiptera: Aphididae) or woolly apple aphid (Eriosoma lanigerum (Hausmann)) (Hemiptera: Aphididae), and minimal interest in cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) in choice and no-choice experiments. Scymnus camptodromus females did not oviposit on any host material other than A. tsugae-infested hemlock. Under the circumstances of the study, S. camptodromus appears to be a specific predator of A. tsugae, with minimal risk to nontarget species. Although the predator can develop on P. strobi, the likelihood that S. camptodromus would oviposit on pine hosts of this adelgid is small.

  1. A Single Residue in Ebola Virus Receptor NPC1 Influences Cellular Host Range in Reptiles.

    Science.gov (United States)

    Ndungo, Esther; Herbert, Andrew S; Raaben, Matthijs; Obernosterer, Gregor; Biswas, Rohan; Miller, Emily Happy; Wirchnianski, Ariel S; Carette, Jan E; Brummelkamp, Thijn R; Whelan, Sean P; Dye, John M; Chandran, Kartik

    2016-01-01

    Filoviruses are the causative agents of an increasing number of disease outbreaks in human populations, including the current unprecedented Ebola virus disease (EVD) outbreak in western Africa. One obstacle to controlling these epidemics is our poor understanding of the host range of filoviruses and their natural reservoirs. Here, we investigated the role of the intracellular filovirus receptor, Niemann-Pick C1 (NPC1) as a molecular determinant of Ebola virus (EBOV) host range at the cellular level. Whereas human cells can be infected by EBOV, a cell line derived from a Russell's viper (Daboia russellii) (VH-2) is resistant to infection in an NPC1-dependent manner. We found that VH-2 cells are resistant to EBOV infection because the Russell's viper NPC1 ortholog bound poorly to the EBOV spike glycoprotein (GP). Analysis of panels of viper-human NPC1 chimeras and point mutants allowed us to identify a single amino acid residue in NPC1, at position 503, that bidirectionally influenced both its binding to EBOV GP and its viral receptor activity in cells. Significantly, this single residue change perturbed neither NPC1's endosomal localization nor its housekeeping role in cellular cholesterol trafficking. Together with other recent work, these findings identify sequences in NPC1 that are important for viral receptor activity by virtue of their direct interaction with EBOV GP and suggest that they may influence filovirus host range in nature. Broader surveys of NPC1 orthologs from vertebrates may delineate additional sequence polymorphisms in this gene that control susceptibility to filovirus infection. IMPORTANCE Identifying cellular factors that determine susceptibility to infection can help us understand how Ebola virus is transmitted. We asked if the EBOV receptor Niemann-Pick C1 (NPC1) could explain why reptiles are resistant to EBOV infection. We demonstrate that cells derived from the Russell's viper are not susceptible to infection because EBOV cannot bind to

  2. Adaptive gene amplification as an intermediate step in the expansion of virus host range.

    Directory of Open Access Journals (Sweden)

    Greg Brennan

    2014-03-01

    Full Text Available The majority of recently emerging infectious diseases in humans is due to cross-species pathogen transmissions from animals. To establish a productive infection in new host species, viruses must overcome barriers to replication mediated by diverse and rapidly evolving host restriction factors such as protein kinase R (PKR. Many viral antagonists of these restriction factors are species specific. For example, the rhesus cytomegalovirus PKR antagonist, RhTRS1, inhibits PKR in some African green monkey (AGM cells, but does not inhibit human or rhesus macaque PKR. To model the evolutionary changes necessary for cross-species transmission, we generated a recombinant vaccinia virus that expresses RhTRS1 in a strain that lacks PKR inhibitors E3L and K3L (VVΔEΔK+RhTRS1. Serially passaging VVΔEΔK+RhTRS1 in minimally-permissive AGM cells increased viral replication 10- to 100-fold. Notably, adaptation in these AGM cells also improved virus replication 1000- to 10,000-fold in human and rhesus cells. Genetic analyses including deep sequencing revealed amplification of the rhtrs1 locus in the adapted viruses. Supplying additional rhtrs1 in trans confirmed that amplification alone was sufficient to improve VVΔEΔK+RhTRS1 replication. Viruses with amplified rhtrs1 completely blocked AGM PKR, but only partially blocked human PKR, consistent with the replication properties of these viruses in AGM and human cells. Finally, in contrast to AGM-adapted viruses, which could be serially propagated in human cells, VVΔEΔK+RhTRS1 yielded no progeny virus after only three passages in human cells. Thus, rhtrs1 amplification in a minimally permissive intermediate host was a necessary step, enabling expansion of the virus range to previously nonpermissive hosts. These data support the hypothesis that amplification of a weak viral antagonist may be a general evolutionary mechanism to permit replication in otherwise resistant host species, providing a molecular foothold

  3. Clarification on host range of Didymella pinodes the causal agent of pea ascochyta blight

    Directory of Open Access Journals (Sweden)

    Eleonora eBarilli

    2016-05-01

    Full Text Available Didymella pinodes is the principal causal agent of ascochyta blight, one of the most important fungal diseases of pea (Pisum sativum worldwide. Understanding its host specificity has crucial implications in epidemiology and management; however, this has not been clearly delineated yet. In this study we attempt to clarify the host range of D. pinodes and to compare it with that of other close Didymella spp. D. pinodes was very virulent on pea accessions, although differences in virulence were identified among isolates. On the contrary, studied isolates D. fabae, D. rabiei and D. lentil showed a reduced ability to infect pea not causing macroscopically visible symptoms on any of the pea accessions tested.D. pinodes isolates were also infective to some extend on almost all species tested including species such as Hedysarum coronarium, Lathyrus sativus, Lupinus albus, Medicago spp., Trifolium spp., Trigonella foenum-graecum and Vicia articulata which were not mentioned before as hosts of D. pinodes. On the contrary, D. lentil and D. rabiei were more specific, infecting only lentil and chickpea, respectively. D. fabae was intermediate, infecting mainly faba bean, but also slightly other species such as Glycine max, Phaseolus vulgaris, Trifolium spp., Vicia sativa and V. articulata.DNA sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS was performed to confirm identity of the isolates studies and to determine phylogenetic relationship among the Didymella species, revealing the presence of two clearly distinct clades. Clade one was represented by two supported subclusters including D. fabae isolates as well as D. rabiei with D. lentil isolates. Clade two was the largest and included all the D. pinodes isolates as well as Phoma medicaginis var. pinodella. Genetic distance between D. pinodes and the other Didymella spp. isolates was not correlated with overall differences in pathogenicity. Based on evidences presented here

  4. The effect of short-range host odor stimuli on host fruit finding and feeding behavior of plum curculio adults (Coleoptera: Curculionidae).

    Science.gov (United States)

    Butkewich, S L; Prokopy, R J

    1993-04-01

    In laboratory assays, we investigated responses of female plum curculios (PCs),Conotrachelus nenuphar (Herbst), to host and nonhost fruit or leaf odor when PCs were crawling on experimental tree branchlets or twigs. In choice tests where test specimens were hung from the ends of a wooden crosspiece, PCs made significantly more visits to host plum fruit than to plum leaves, nonhost tomato fruit, wax models of plum fruit, or blanks (wire). In similar tests, PCs made significantly more visits to plum leaves compared to nonhost maple leaves or to blanks. PCs in test chambers that contained host or nonhost odor were significantly more prone to feed on wax plum models in the presence of odor from host fruit or host leaves compared to odor from nonhost fruit or leaves or a water blank. In choice tests offering alternating cluster types on an apple branchlet, PCs visited leaf clusters bearing a host apple fruit more than leaf clusters without a fruit. In tests to assay the distance at which PCs can detect an individual host fruit, PCs crawled from the central stem of an apple branchlet onto a side stem significantly more often when an apple fruit on a side stem was hung 2 cm from the central stem compared to 4 or 8 cm away. Our combined results suggest that PCs use host fruit odor to locate host fruit at close range.

  5. Mapping Type IV Secretion Signals on the Primase Encoded by the Broad-Host-Range Plasmid R1162 (RSF1010).

    Science.gov (United States)

    Meyer, Richard

    2015-10-01

    The plasmid R1162 (RSF1010) encodes a primase essential for its replication. This primase makes up the C-terminal part of MobA, a multifunctional protein with the relaxase as a separate N-terminal domain. The primase is also translated separately as the protein RepB'. Here, we map two signals for type IV secretion onto the recently solved structure of RepB'. One signal is located internally within RepB' and consists of a long α-helix and an adjacent disordered region rich in arginines. The second signal is made up of the same α-helix and a second, arginine-rich region at the C-terminal end of the protein. Successive arginine-to-alanine substitutions revealed that either signal can be utilized by the type IV secretion complex of the plasmid R751. The internal signal also enables conjugal transfer when linked to the relaxase part of MobA. Both signals are similar to those previously identified for type IV secretion substrates in the Vir system of Agrobacterium tumefaciens. Moreover, the C-terminal arginine-rich segment of RepB' has been shown to be secreted by Vir. However, with R751, the signals require MobB, an R1162-encoded accessory protein active in conjugal transfer. The results of two-hybrid assays revealed that MobB interacts, via its membrane-associated domain, with the R751 plasmid coupling protein TraG. In addition, MobB interacts with a region of MobA just outside the RepB' domain. Therefore, MobB is likely an adaptor that is essential for recognition of the primase-associated signals by the R751 secretion machinery. For most plasmids, type IV secretion is an intrinsic part of the mechanism for conjugal transfer. Protein relaxases, bound to the 5' end of the transferring strand, are mobilized into recipient cells by the type IV pathway. In this work, we identify and characterize two signals for secretion in the primase domain of MobA, the relaxase of the IncQ plasmid R1162 (RSF1010). We also show that the adaptor protein MobB is required for engagement of these signals with the R751 coupling protein TraG. These results clarify the location and properties of secretion signals active during the conjugal transfer of plasmid DNA. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  6. Genome degradation in Brucella ovis corresponds with narrowing of its host range and tissue tropism.

    Directory of Open Access Journals (Sweden)

    Renee M Tsolis

    Full Text Available Brucella ovis is a veterinary pathogen associated with epididymitis in sheep. Despite its genetic similarity to the zoonotic pathogens B. abortus, B. melitensis and B. suis, B. ovis does not cause zoonotic disease. Genomic analysis of the type strain ATCC25840 revealed a high percentage of pseudogenes and increased numbers of transposable elements compared to the zoonotic Brucella species, suggesting that genome degradation has occurred concomitant with narrowing of the host range of B. ovis. The absence of genomic island 2, encoding functions required for lipopolysaccharide biosynthesis, as well as inactivation of genes encoding urease, nutrient uptake and utilization, and outer membrane proteins may be factors contributing to the avirulence of B. ovis for humans. A 26.5 kb region of B. ovis ATCC25840 Chromosome II was absent from all the sequenced human pathogenic Brucella genomes, but was present in all of 17 B. ovis isolates tested and in three B. ceti isolates, suggesting that this DNA region may be of use for differentiating B. ovis from other Brucella spp. This is the first genomic analysis of a non-zoonotic Brucella species. The results suggest that inactivation of genes involved in nutrient acquisition and utilization, cell envelope structure and urease may have played a role in narrowing of the tissue tropism and host range of B. ovis.

  7. WATERMELON MOSAIC VIRUS OF PUMPKIN (Cucurbita maxima FROM SULAWESI: IDENTIFICATION, TRANSMISSION, AND HOST RANGE

    Directory of Open Access Journals (Sweden)

    Wasmo Wakmana

    2016-10-01

    Full Text Available A mosaic disease of pumpkin (Cucurbita maxima was spread widely in Sulawesi. Since the virus had not yet been identified, a study was conducted to identify the disease through mechanical inoculation, aphid vector transmission, host range, and electron microscopic test. Crude sap of infected pumpkin leaf samples was rubbed on the cotyledons of healthy pumpkin seedlings for mechanical inoculation. For insect transmission, five infective aphids were infected per seedling. Seedlings of eleven different species were inoculated mechanically for host range test. Clarified sap was examined under the electron microscope. Seeds of two pumpkin fruits from two different infected plants were planted and observed for disease transmission up to one-month old seedlings. The mosaic disease was transmitted mechanically from crude sap of different leaf samples to healthy pumpkin seedlings showing mosaic symptoms. The virus also infected eight cucurbits, i.e., cucumber (Cucumis sativus, green melon (Cucumis melo, orange/rock melon (C. melo, zucchini (Cucurbita pepo, pumpkin (Cucurbita maxima, water melon (Citrulus vulgaris, Bennicosa hispida, and blewah (Cucurbita sp.. Aphids  transmitted the disease from one to other pumpkin seedlings. The virus was not transmitted by seed. The mosaic disease of pumpkin at Maros, South Sulawesi, was associated with flexious particles of approximately 750 nm length, possibly a potyvirus, such as water melon mosaic virus rather than papaya ringspot virus or zucchini yellow mosaic virus.

  8. Natural host-range and experimental transmission of Laem-Singh virus (LSNV).

    Science.gov (United States)

    Kumar, T Sathish; Krishnan, P; Makesh, M; Chaudhari, A; Purushothaman, C S; Rajendran, K V

    2011-08-29

    Slow growth caused by viral diseases has become a major constraint in shrimp aquaculture. Laem-Singh virus (LSNV), a positive-sense single-stranded RNA (ssRNA) virus, has been identified in Penaeus monodon showing slow growth syndrome. To examine the host-range and transmission modes of the virus, 6 species of penaeid shrimp of varying life stages, sourced from the wild and from farms, as well as juvenile mud crabs Scylla serrata, were screened using RT-nested PCR. LSNV was detected in P. monodon, Fenneropenaeus merguiensis, Metapenaeus dobsoni, and Litopenaeus vannamei, but not in E indicus, Marsupenaeus japonicus or S. serrata. LSNV was most prevalent in P. monodon followed by M. dobsoni, F. merguiensis, and L. vannamei, and real-time quantitative RT-PCR (qRT-PCR) showed that LSNV infection loads were highest in P. monodon, followed by L. vannamei, M. dobsoni, and E merguiensis. The nucleotide sequence of the LSNV RdRP gene fragment amplified by RT-nested PCR was highly conserved (99% identity) across these 4 penaeid species. LSNV was detected in both small and normal-sized P. monodon collected from the same pond. In experimental infections of both P. monodon and S. serrata, LSNV infection loads increased over time. The present study extends the known natural penaeid host-range and geographical distribution of LSNV and shows for the first time the potential susceptibility of S. serrata.

  9. Role of SH3b binding domain in a natural deletion mutant of Kayvirus endolysin LysF1 with a broad range of lytic activity.

    Science.gov (United States)

    Benešík, Martin; Nováček, Jiří; Janda, Lubomír; Dopitová, Radka; Pernisová, Markéta; Melková, Kateřina; Tišáková, Lenka; Doškař, Jiří; Žídek, Lukáš; Hejátko, Jan; Pantůček, Roman

    2018-02-01

    The spontaneous host-range mutants 812F1 and K1/420 are derived from polyvalent phage 812 that is almost identical to phage K, belonging to family Myoviridae and genus Kayvirus. Phage K1/420 is used for the phage therapy of staphylococcal infections. Endolysin of these mutants designated LysF1, consisting of an N-terminal cysteine-histidine-dependent aminohydrolase/peptidase (CHAP) domain and C-terminal SH3b cell wall-binding domain, has deleted middle amidase domain compared to wild-type endolysin. In this work, LysF1 and both its domains were prepared as recombinant proteins and their function was analyzed. LysF1 had an antimicrobial effect on 31 Staphylococcus species of the 43 tested. SH3b domain influenced antimicrobial activity of LysF1, since the lytic activity of the truncated variant containing the CHAP domain alone was decreased. The results of a co-sedimentation assay of SH3b domain showed that it was able to bind to three types of purified staphylococcal peptidoglycan 11.2, 11.3, and 11.8 that differ in their peptide bridge, but also to the peptidoglycan type 11.5 of Streptococcus uberis, and this capability was verified in vivo using the fusion protein with GFP and fluorescence microscopy. Using several different approaches, including NMR, we have not confirmed the previously proposed interaction of the SH3b domain with the pentaglycine bridge in the bacterial cell wall. The new naturally raised deletion mutant endolysin LysF1 is smaller than LysK, has a broad lytic spectrum, and therefore is an appropriate enzyme for practical use. The binding spectrum of SH3b domain covering all known staphylococcal peptidoglycan types is a promising feature for creating new chimeolysins by combining it with more effective catalytic domains.

  10. Using Cloud-Hosted Real-time Data Services for the Geosciences (CHORDS) in a range of geoscience applications

    Science.gov (United States)

    Daniels, M. D.; Kerkez, B.; Chandrasekar, V.; Graves, S. J.; Stamps, D. S.; Dye, M. J.; Keiser, K.; Martin, C. L.; Gooch, S. R.

    2016-12-01

    Cloud-Hosted Real-time Data Services for the Geosciences, or CHORDS, addresses the ever-increasing importance of real-time scientific data, particularly in mission critical scenarios, where informed decisions must be made rapidly. Part of the broader EarthCube initiative, CHORDS seeks to investigate the role of real-time data in the geosciences. Many of the phenomenon occurring within the geosciences, ranging from hurricanes and severe weather, to earthquakes, volcanoes and floods, can benefit from better handling of real-time data. The National Science Foundation funds many small teams of researchers residing at Universities whose currently inaccessible measurements could contribute to a better understanding of these phenomenon in order to ultimately improve forecasts and predictions. This lack of easy accessibility prohibits advanced algorithm and workflow development that could be initiated or enhanced by these data streams. Often the development of tools for the broad dissemination of their valuable real-time data is a large IT overhead from a pure scientific perspective, and could benefit from an easy to use, scalable, cloud-based solution to facilitate access. CHORDS proposes to make a very diverse suite of real-time data available to the broader geosciences community in order to allow innovative new science in these areas to thrive. We highlight the recently developed CHORDS portal tools and processing systems aimed at addressing some of the gaps in handling real-time data, particularly in the provisioning of data from the "long-tail" scientific community through a simple interface deployed in the cloud. Examples shown include hydrology, atmosphere and solid earth sensors. Broad use of the CHORDS framework will expand the role of real-time data within the geosciences, and enhance the potential of streaming data sources to enable adaptive experimentation and real-time hypothesis testing. CHORDS enables real-time data to be discovered and accessed using

  11. Climate-driven variation in the intensity of a host-symbiont animal interaction along a broad elevation gradient.

    Directory of Open Access Journals (Sweden)

    Leandro Meléndez

    Full Text Available Gradients of environmental stress may affect biotic interactions in unpredictable ways responding to climate variation, depending on the abiotic stress tolerance of interacting partners. Here, we study the effect of local climate on the intensity of feather mites in six mountain passerines along a 1400 m elevational gradient characterized by shifting temperature and rainfall. Although obligatory symbionts of warm-blooded organisms are assumed to live in mild and homeothermic environments, those inhabiting external, non-blood-irrigated body portions of the host organism, such as feather mites, are expected to endure exposure to the direct influence of a fluctuating climate. As expected, feather mite intensity declined with elevation in all bird species, a pattern that was also found in cold-adapted passerines that have typical alpine habits. The elevation cline was mainly explained by a positive effect of the average temperature upon mite intensity in five of the six species studied. Precipitation explained less variance in mite intensity than average temperature, and showed a negative correlation in half of the studied species. We found no climate-driven migration of mites along the wings of birds, no replacement of mite species along elevation gradients and no association with available food resources for mites (estimated by the size of the uropygial gland. This study suggests that ectosymbionts of warm-blooded animals may be highly sensitive to climatic variation and become less abundant under stressful environmental conditions, providing empirical evidence of the decline of specialized biotic interactions among animal species at high elevations.

  12. Host range of Neozygites floridana isolates (zygomycetes: entomophthorales) to spider mites.

    Science.gov (United States)

    Ribeiro, Ana Elizabete Lopes; Gondim, Manoel Guedes Corrêa; Calderan, Eveline; Delalibera, Italo

    2009-11-01

    Neozygites floridana (Weiser & Muma) (Zygomycetes: Entomophthorales) has been reported infecting naturally at least 18 species of tetranychids worldwide. However, the host range of N. floridana is unknown. Epizootics caused by this pathogen to tetranychid populations indicate that N. floridana has the potential to be used as a biological control agent. However, the virulence and specificity of species and strains of Neozygites need to be assessed in the laboratory to reveal its potential as a biological control agent. N. floridana isolates are currently been investigated in Brazil as biological control agents against the tomato red mite, Tetranychus evansi Baker & Pritchard, and the two-spotted spider mite, Tetranychus urticae Koch. The pathogenicity of five strains of N. floridana obtained from T. urticae, T. evansi and T. ludeni Zacher was assessed against populations of Mononychellus tanajoa (Bondar), Schizotetranychus sacharum Flechtmann & Baker, Tetranychus abacae Baker & Pritchard and Tetranychus armipenis Flechtmann & Baker, in addition to the species from which the fungus was obtained. Mummified mites were placed on leaf discs of the host plant of each tetranychid to promote fungal sporulation, and after 24h the mites were transferred to the leaf discs. Contamination, infection and mummification were evaluated daily for seven days after confinement. Each isolate was pathogenic to three or four out of the six spider mite species tested. However, except for isolate ESALQ1421, all isolates caused higher levels of infection and significant mummification only to the tetranychid species from which they were collected. None of the isolates was pathogenic to S. sacharum and only one isolate infected T. abacae. Alternative hosts may be important for N. floridana survival in tropical regions where resting spores are rarely found.

  13. Lack of clinical manifestations in asymptomatic dengue infection is attributed to broad down-regulation and selective up-regulation of host defence response genes.

    Directory of Open Access Journals (Sweden)

    Adeline S L Yeo

    Full Text Available OBJECTIVES: Dengue represents one of the most serious life-threatening vector-borne infectious diseases that afflicts approximately 50 million people across the globe annually. Whilst symptomatic infections are frequently reported, asymptomatic dengue remains largely unnoticed. Therefore, we sought to investigate the immune correlates conferring protection to individuals that remain clinically asymptomatic. METHODS: We determined the levels of neutralizing antibodies (nAbs and gene expression profiles of host immune factors in individuals with asymptomatic infections, and whose cognate household members showed symptoms consistent to clinical dengue infection. RESULTS: We observed broad down-regulation of host defense response (innate, adaptive and matrix metalloprotease genes in asymptomatic individuals as against symptomatic patients, with selective up-regulation of distinct genes that have been associated with protection. Selected down-regulated genes include: TNF α (TNF, IL8, C1S, factor B (CFB, IL2, IL3, IL4, IL5, IL8, IL9, IL10 and IL13, CD80, CD28, and IL18, MMP8, MMP10, MMP12, MMP15, MMP16, and MMP24. Selected up-regulated genes include: RANTES (CCL5, MIP-1α (CCL3L1/CCL3L3, MIP-1β (CCL4L1, TGFβ (TGFB, and TIMP1. CONCLUSION: Our findings highlight the potential association of certain host genes conferring protection against clinical dengue. These data are valuable to better explore the mysteries behind the hitherto poorly understood immunopathogenesis of subclinical dengue infection.

  14. Genetic diversity and host range variation of Ralstonia solanacearum strains entering North America.

    Science.gov (United States)

    Norman, David J; Zapata, Mildred; Gabriel, Dean W; Duan, Y P; Yuen, Jeanne M F; Mangravita-Novo, Arianna; Donahoo, Ryan S

    2009-09-01

    Each year, large volumes of ornamental and food plant propagative stock are imported into the North America; occasionally, Ralstonia solanacearum is found systemically infecting this plant material. In this study, 107 new R. solanacearum strains were collected over a 10-year period from imported propagative stock and compared with 32 previously characterized R. solanacearum strains using repetitive polymerase chain reaction (rep-PCR) element (BOX, ERIC, and REP) primers. Additional strain comparisons were made by sequencing the endoglucanase and the cytochrome b561 genes. Using rep-PCR primers, populations could be distinguished by biovar and, to a limited extent, country of origin and original host. Similarity coefficients among rep-PCR clusters within biovars were relatively low in many cases, indicating that disease outbreaks over time may have been caused by different clonal populations. Similar population differentiations of R. solanacearum were obtained when comparing strain sequences using either the endoglucanase or cytochrome b561 genes. We found that most of the new biovar 1 strains of R. solanacearum entering the United States were genetically distinct from the biovar 1 strains currently found infecting vegetable production. These introduced biovar 1 strains also had a broader host range and could infect not only tomato, tobacco, and potato but also anthurium and pothos and cause symptoms on banana. All introductions into North America of race 3, biovar 2 strains in the last few years have been linked to geranium production and appeared to be clonal.

  15. Species identification, host range and diversity of Cecidophyopsis mites (Acari: Trombidiformes) infesting Ribes in Latvia.

    Science.gov (United States)

    Stalažs, Arturs; Moročko-Bičevska, Inga

    2016-06-01

    Cecidophyopsis mites are important pests in all cultivation regions of Ribes causing bud galls and sterility. Despite their economic importance, the knowledge on Cecidophyopsis species infesting Ribes in various areas of the world is still deficient. The present study was carried out to identify Cecidophyopsis species occurring in Latvia on cultivated and wild Ribes, to assess their host range and gain insight into the genetic diversity of these insufficiently studied pests by use of multiplex PCR, rDNA sequences and morphological characters. Cecidophyopsis alpina, C. aurea, C. spicata and C. selachodon were detected to occur in all surveyed habitats. For the first time, C. alpina was identified on blackcurrants and redcurrants, and C. aurea on redcurrants, blackcurrants and alpine currants. The presence of C. ribis was not confirmed with molecular tools during this study. Phylogenetic analyses confirmed the presence of four Cecidophyopsis species identified by multiplex PCR. A close phylogenetic relatedness was found for C. aurea and C. alpina, and for C. ribis and C. spicata highlighting the necessity for additional studies. Our findings suggest a need to consider also other Cecidophyopsis species besides C. ribis in breeding programs for host resistance to mites.

  16. Genomic, proteomic and morphological characterization of two novel broad host lytic bacteriophages (phi)PD10.3 and (phi)PD23.1 infecting pectinolytic Pectobacterium spp. and Dickeya spp.

    NARCIS (Netherlands)

    Czajkowski, Robert; Ozymko, Zofia; de Jager, Victor; Siwinska, Joanna; Smolarska, Anna; Ossowicki, Adam; Narajczyk, Magdalena; Lojkowska, Ewa

    2015-01-01

    Pectinolytic Pectobacterium spp. and Dickeya spp. are necrotrophic bacterial pathogens of many important crops, including potato, worldwide. This study reports on the isolation and characterization of broad host lytic bacteriophages able to infect the dominant Pectobacterium spp. and Dickeya spp.

  17. Detection of bacteria in platelet concentrates: comparison of broad-range real-time 16S rDNA polymerase chain reaction and automated culturing

    NARCIS (Netherlands)

    Mohammadi, Tamimount; Pietersz, Ruby N. I.; Vandenbroucke-Grauls, Christina M. J. E.; Savelkoul, Paul H. M.; Reesink, Henk W.

    2005-01-01

    BACKGROUND: Based on real-time polymerase chain reaction (PCR) technology, a broad-range 16S rDNA assay was validated and its performance was compared to that of an automated culture system to determine its usefulness for rapid routine screening of platelet concentrates (PCs). STUDY DESIGN AND

  18. Heat capacity and Joule-Thomson coefficient of selected n-alkanes at 0.1 and 10 MPa in broad temperature ranges

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Varzandeh, Farhad; Stenby, Erling Halfdan

    2017-01-01

    Isobaric heat capacity of six n-alkanes, i.e. n-hexane, n-octane, n-decane, n-dodecane, n-tetradecane and n-hexadecane, was determined with a Calvet type differential heat-flux calorimeter at 0.1 and 10 MPa in a broad temperature range. The measured isobaric heat capacity data were combined...

  19. Disentangling climatic versus biotic drivers of tree range constraints: Broad scale tradeoffs between climate and competion rarely explain local range boundaries

    Science.gov (United States)

    Anderegg, L. D. L.; Hillerislambers, J.

    2016-12-01

    Accurate prediction of climatically-driven range shifts requires knowledge of the dominant forces constraining species ranges, because climatically controlled range boundaries will likely behave differently from biotically controlled range boundaries in a changing climate. Yet the roles of climatic constraints (due to species physiological tolerance) versus biotic constraints (caused by species interactions) on geographic ranges are largely unknown, infusing large uncertainty into projections of future range shifts. Plant species ranges across strong climatic gradients such as elevation gradients are often assumed to represent a tradeoff between climatic constraints on the harsh side of the range and biotic constraints (often competitive constraints) on the climatically benign side. To test this assumption, we collected tree cores from across the elevational range of the three dominant tree species inhabiting each of three climatically disparate mountain slopes and assessed climatic versus competitive constraints on growth at each species' range margins. Across all species and mountains, we found evidence for a tradeoff between climatic and competitve growth constraints. We also found that some individual species did show an apparent trade-off between a climatic constraint at one range margin and a competitive constraint at the other. However, even these simple elevation gradients resulted in complex interactions between temperature, moisture, and competitive constraints such that a climate-competition tradeoff did not explain range constraints for many species. Our results suggest that tree species can be constrained by a simple trade-off between climate and competition, but that the intricacies of real world climate gradients complicate the application of this theory even in apparently harsh environments, such as near high elevation tree line.

  20. Global displacement of canine parvovirus by a host-adapted variant: structural comparison between pandemic viruses with distinct host ranges.

    Science.gov (United States)

    Organtini, Lindsey J; Allison, Andrew B; Lukk, Tiit; Parrish, Colin R; Hafenstein, Susan

    2015-02-01

    Canine parvovirus type 2 (CPV-2) emerged in 1978 and spread worldwide within 2 years. Subsequently, CPV-2 was completely replaced by the variant CPV-2a, which is characterized by four specific capsid (VP2) mutations. The X-ray crystal structure of the CPV-2a capsid shows that each mutation confers small local changes. The loss of a hydrogen bond and introduction of a glycine residue likely introduce flexibility to sites that control interactions with the host receptor, antibodies, and sialic acids. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Sugarcane Aphid (Hemiptera: Aphididae): Host Range and Sorghum Resistance Including Cross-Resistance From Greenbug Sources.

    Science.gov (United States)

    Armstrong, J Scott; Rooney, William L; Peterson, Gary C; Villenueva, Raul T; Brewer, Michael J; Sekula-Ortiz, Danielle

    2015-04-01

    The graminous host range and sources of sorghum [Sorghum bicolor (L.) Moench.] plant resistance, including cross-resistance from greenbug, Schizaphis graminum (Rondani), were studied for the newly emerging sugarcane aphid, Melanaphis sacchari (Zehntner), in greenhouse no-choice experiments and field evaluations. The sugarcane aphid could not survive on field corn, Zea mays (L.), Teff grass, Eragrostis tef (Zucc.), proso millet, Panicum miliaceum L., barley, Hordeum vulgare L., and rye, Secale cereale L. Only sorghum genotypes served as hosts including Johnsongrass, Sorghum halepense (L.), a highly suitable noncrop host that generates high numbers of sugarcane aphid and maintains moderate phenotypic injury. The greenbug-resistant parental line RTx2783 that is resistant to greenbug biotypes C and E was resistant to sugarcane aphid in both greenhouse and field tests, while PI 55607 greenbug resistant to biotypes B, C, and E was highly susceptible. PI 55610 that is greenbug resistant to biotypes B, C, and E maintained moderate resistance to the sugarcane aphid, while greenbug-resistant PI 264453 was highly susceptible to sugarcane aphid. Two lines and two hybrids from the Texas A&M breeding program B11070, B11070, AB11055-WF1-CS1/RTx436, and AB11055-WF1-CS1/RTx437 were highly resistant to sugarcane aphid, as were parental types SC110, SC170, and South African lines Ent62/SADC, (Macia/TAM428)-LL9, (SV1*Sima/IS23250)-LG15. Tam428, a parental line that previously showed moderate resistance in South Africa and India, also showed moderate resistance in these evaluations. Overall, 9 of 20 parental sorghum entries tested for phenotypic damage in the field resulted in good resistance to the sugarcane aphid and should be utilized in breeding programs that develop agronomically acceptable sorghums for the southern regions of the United States. Published by Oxford University Press on behalf of Entomological Society of America. 2015. This work is written by US Government employees

  2. Assessing physiological tipping point of sea urchin larvae exposed to a broad range of pH

    OpenAIRE

    Dorey, Narimane; Lançon, Pauline; Thorndyke, Mike; Dupont, Sam

    2013-01-01

    Our ability to project the impact of global change on marine ecosystem is limited by our poor understanding on how to predict species sensitivity. For example, the impact of ocean acidification is highly species-specific, even in closely related taxa. The aim of this study was to test the hypothesis that the tolerance range of a given species to decreased pH corresponds to their natural range of exposure. Larvae of the green sea urchin Strongylocentrotus droebachiensis were cultured from fert...

  3. Seasonal alterations in host range and fidelity in the polyphagous mirid bug, Apolygus lucorum (Heteroptera: Miridae.

    Directory of Open Access Journals (Sweden)

    Hongsheng Pan

    Full Text Available In herbivorous insects, host plant switching is commonly observed and plays an important role in their annual life cycle. However, much remains to be learned about seasonal host switching of various pestiferous arthropods under natural conditions. From 2006 until 2012, we assessed Apolygus lucorum (Meyer-Dür host plant use in successive spring, summer and winter seasons at one single location (Langfang, China. Data were used to quantify changes in host plant breadth and host fidelity between seasons. Host fidelity of A. lucorum differed between seasons, with 87.9% of spring hosts also used in the summer and 36.1% of summer hosts used in winter. In contrast, as little as 25.6% host plant species were shared between winter and spring. Annual herbaceous plants are most often used for overwintering, while perennial woody plants are relatively important for initial population build-up in the spring. Our study contributes to an improved understanding of evolutionary interactions between A. lucorum and its host plants and lays the groundwork for the design of population management strategies for this important pest in myriad crops.

  4. Life Outcomes and Higher Education: The Need for Longitudinal Research Using a Broad Range of Quality of Life Indicators.

    Science.gov (United States)

    Sheppard-Jones, Kathleen; Kleinert, Harold; Butler, Laura; Whaley, Barry

    2018-02-01

    Higher education is increasingly becoming an option for young adults with intellectual disability (ID). Although initial evaluations of postsecondary education for this population have been promising, a broader "quality of life" framework needs to be adopted in order to truly understand the impact of these programs. Moreover, researchers and program evaluators must collect longitudinal data that follows former students for multiple years and uses multiple measures. We conducted a pilot evaluation of the life outcomes of students who had attended at least two semesters in Kentucky's supported higher education program for students with ID, collecting data on life status and experiences using measures from the National Core Indicators-Adult Consumer Survey. The findings from this pilot study show better outcomes for young adults who participated in a postsecondary education program compared to young adults who did not, but these findings need to be considered in light of several limitations. In many respects, our data provided more new questions than answers. Recommendations for collecting and evaluating broad-based, longitudinal data to gain insight into the potential benefits of postsecondary education for people with intellectual disability are discussed.

  5. Leaf hydraulic vulnerability to drought is linked to site water availability across a broad range of species and climates

    Science.gov (United States)

    Background and Aims: Vulnerability of the leaf hydraulic pathway to water-stress-induced dysfunction is a key component of drought tolerance in plants and may be important in defining species’ climatic range. However, the generality of the association between leaf hydraulic vulnerability and climate...

  6. Piriformospora indica-a mutualistic basidiomycete with an exceptionally large plant host range.

    Science.gov (United States)

    Qiang, Xiaoyu; Weiss, Michael; Kogel, Karl-Heinz; Schäfer, Patrick

    2012-06-01

    Piriformospora indica is a basidiomycete of the order Sebacinales, representing a model for the study of mutualistic symbiosis and, beyond that, the plant immune system. The fungus colonizes the roots of a wide range of vascular plants, increasing their growth, seed yield and adaptation to abiotic and biotic stresses. The fungal colonization of roots begins with a biotrophic growth phase, in which living cells are colonized, and continues with a cell death-dependent phase, in which root cells are actively killed by the fungus. The complexity of sebacinalean symbiosis is further enhanced by the presence of endocellular bacteria which may represent significant determinants for a successful outcome of the symbioses. Molecular ecological analyses have revealed an exceptional relevance of sebacinoid fungi in natural ecosystems worldwide. This natural competence could be rooted in their phenotypic adaptability, which, for instance, allows P. indica to grow readily on various synthetic media and to colonize distinct hosts. In molecular and genetic studies, P. indica's mutualistic colonization strategy has been partly unravelled, showing that the jasmonate pathway is exploited for immune suppression and successful development in roots. Research on P. indica supports efforts to make the bioprotective potential of the fungus accessible for agricultural plant production. The decoding of P. indica's genome has revealed its potential for application as bioagent and for targeted improvement of crop plants in biotechnology-based approaches. © 2011 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2011 BSPP AND BLACKWELL PUBLISHING LTD.

  7. Construction of a self- luminescent cyanobacterial bioreporter that detects a broad range of bioavailable heavy metals in aquatic environments

    Directory of Open Access Journals (Sweden)

    Keila eMartin-Betancor

    2015-03-01

    Full Text Available A self-luminescent bioreporter strain of the unicellular cyanobacterium Synechococcus sp. PCC 7942 was constructed by fusing the promoter region of the smt locus (encoding the transcriptional repressor SmtB and the metallothionein SmtA to luxCDABE from Photorhabdus luminescens; the sensor smtB gene controlling the expression of smtA was cloned in the same vector. The bioreporter performance was tested with a range of heavy metals and was shown to respond linearly to divalent Zn, Cd, Cu, Co, Hg and monovalent Ag. Chemical modelling was used to link bioreporter response with metal speciation and bioavailability. Limits of Detection (LODs, Maximum Permissive Concentrations (MPCs and dynamic ranges for each metal were calculated in terms of free ion concentrations. The ranges of detection varied from 11 to 72 pM for Hg2+ (the ion to which the bioreporter was most sensitive to 1.54-5.35 µM for Cd2+ with an order of decreasing sensitivity as follows: Hg2+ >> Cu2+ >> Ag+ > Co2+ ≥ Zn2+ > Cd2+. However, the maximum induction factor reached 75-fold in the case of Zn2+ and 56-fold in the case of Cd2+, implying that Zn2+ is the preferred metal in vivo for the SmtB sensor, followed by Cd2+, Ag+ and Cu2+ (around 45-50-fold induction, Hg2+ (30-fold and finally Co2+ (20-fold. The bioreporter performance was tested in real environmental samples with different water matrix complexity artificially contaminated with increasing concentrations of Zn, Cd, Ag and Cu, confirming its validity as a sensor of free heavy metal cations bioavailability in aquatic environments.

  8. Ab initio molecular dynamics study of fluid H2O-CO2 mixture in broad pressure-temperature range

    Science.gov (United States)

    Fu, Jie; Zhao, Jijun; Plyasunov, Andrey V.; Belonoshko, Anatoly B.

    2017-11-01

    Properties of H2O and CO2 fluid and their mixtures under extreme pressures and temperatures are poorly known yet critically important in a number of applications. Several hundreds of first-principles molecular dynamics (FPMD) runs have been performed to obtain the pressure-volume-temperature (P-V-T) data on supercritical H2O, CO2, and H2O-CO2 mixtures. The pressure-temperature (P-T) range are from 0.5 GPa to 104 GPa (48.5 GPa for CO2) and from 600 K to 4000 K. Based on these data, we evaluate several existing equations of state (EOS) for the fluid H2O, CO2, and H2O-CO2 mixture. The results show that the EOS for H2O from Belonoshko et al. [Geochim. Cosmochim. Acta 55, 381-387; Geochim. Cosmochim. Acta 55, 3191-3208; Geochim. Cosmochim. Acta 56, 3611-3626; Comput. Geosci. 18, 1267-1269] not only can be used in the studied P-T range but also is accurate enough to be used for prediction of P-V-T data. In addition, IAPWS-95 EOS for H2O shows excellent extrapolation behavior beyond 1.0 GPa and 1273 K. However, for the case of CO2, none of the existing EOS produces data in agreement with the FPMD results. We created new EOS for CO2. The precision of the new EOS is tested by comparison to the calculated P-V-T data, fugacity coefficient of the CO2 fluid derived from high P-T experimental data as well as to the (very scarce) experimental volumetric data in the high P-T range. On the basis of our FPMD data we created a new EOS for H2O-CO2 mixture. The new EOS for the mixture is in reasonable agreement with experimental data.

  9. Assessing physiological tipping point of sea urchin larvae exposed to a broad range of pH.

    Science.gov (United States)

    Dorey, Narimane; Lançon, Pauline; Thorndyke, Mike; Dupont, Sam

    2013-11-01

    Our ability to project the impact of global change on marine ecosystem is limited by our poor understanding on how to predict species sensitivity. For example, the impact of ocean acidification is highly species-specific, even in closely related taxa. The aim of this study was to test the hypothesis that the tolerance range of a given species to decreased pH corresponds to their natural range of exposure. Larvae of the green sea urchin Strongylocentrotus droebachiensis were cultured from fertilization to metamorphic competence (29 days) under a wide range of pH (from pHT  = 8.0/pCO2  ≈ 480 μatm to pHT  = 6.5/pCO2  ≈ 20 000 μatm) covering present (from pHT 8.7 to 7.6), projected near-future variability (from pHT 8.3 to 7.2) and beyond. Decreasing pH impacted all tested parameters (mortality, symmetry, growth, morphometry and respiration). Development of normal, although showing morphological plasticity, swimming larvae was possible as low as pHT  ≥ 7.0. Within that range, decreasing pH increased mortality and asymmetry and decreased body length (BL) growth rate. Larvae raised at lowered pH and with similar BL had shorter arms and a wider body. Relative to a given BL, respiration rates and stomach volume both increased with decreasing pH suggesting changes in energy budget. At the lowest pHs (pHT  ≤ 6.5), all the tested parameters were strongly negatively affected and no larva survived past 13 days post fertilization. In conclusion, sea urchin larvae appeared to be highly plastic when exposed to decreased pH until a physiological tipping point at pHT  = 7.0. However, this plasticity was associated with direct (increased mortality) and indirect (decreased growth) consequences for fitness. © 2013 John Wiley & Sons Ltd.

  10. Influences of the common FTO rs9939609 variant on inflammatory markers throughout a broad range of body mass index

    DEFF Research Database (Denmark)

    Zimmermann, Esther; Skogstrand, Kristin; Hougaard, David M

    2011-01-01

    A recent study reported that the fatness associated A-allele of FTO rs9939609 increased plasma high sensitivity C-reactive protein (hs-CRP) levels independent of fatness. We aimed to investigate if this gene variant had fatness-independent effects on plasma hs-CRP and 10 additional circulating ob...... obesity-related adipokines throughout a broad range of body mass index (BMI) among Danish men....

  11. Characterization of extended range Bonner Sphere Spectrometers in the CERF high-energy broad neutron field at CERN

    Science.gov (United States)

    Agosteo, S.; Bedogni, R.; Caresana, M.; Charitonidis, N.; Chiti, M.; Esposito, A.; Ferrarini, M.; Severino, C.; Silari, M.

    2012-12-01

    The accurate determination of the ambient dose equivalent in the mixed neutron-photon fields encountered around high-energy particle accelerators still represents a challenging task. The main complexity arises from the extreme variability of the neutron energy, which spans over 10 orders of magnitude or more. Operational survey instruments, which response function attempts to mimic the fluence-to-ambient dose equivalent conversion coefficient up to GeV neutrons, are available on the market, but their response is not fully reliable over the entire energy range. Extended range rem counters (ERRC) do not require the exact knowledge of the energy distribution of the neutron field and the calibration can be done with a source spectrum. If the actual neutron field has an energy distribution different from the calibration spectrum, the measurement is affected by an added uncertainty related to the partial overlap of the fluence-to-ambient dose equivalent conversion curve and the response function. For this reason their operational use should always be preceded by an "in-field" calibration, i.e. a calibration made against a reference instrument exposed in the same field where the survey-meter will be employed. In practice the extended-range Bonner Sphere Spectrometer (ERBSS) is the only device which can serve as reference instrument in these fields, because of its wide energy range and the possibility to assess the neutron fluence and the ambient dose equivalent (H*(10)) values with the appropriate accuracy. Nevertheless, the experience gained by a number of experimental groups suggests that mandatory conditions for obtaining accurate results in workplaces are: (1) the use of a well-established response matrix, thus implying validation campaigns in reference monochromatic neutrons fields, (2) the expert and critical use of suitable unfolding codes, and (3) the performance test of the whole system (experimental set-up, elaboration and unfolding procedures) in a well

  12. Unified one-dimensional model of bounded plasma with nonzero ion temperature in a broad pressure range

    Energy Technology Data Exchange (ETDEWEB)

    Palacio Mizrahi, J. H.; Gurovich, V. Tz.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2013-03-15

    A one-dimensional model for steady state plasmas bounded either between large parallel walls, or by a cylinder or a sphere, valid in a wide range of gas pressures, is considered. The model includes nonzero ion temperature, inertial terms in the ion momentum equations, and allows one to calculate the plasma electron temperature and ion current density reaching the wall, as well as the spatial distributions of the ion fluid velocity, plasma density, and plasma potential in the plasma bulk. In addition, the effect of electron inertia is analyzed. The model includes as particular cases several earlier models that were based on a similar set of differential equations, but that are restricted to a specific pressure regime (low, intermediate, or high). Analytical solution is found in planar geometry, and numerical solution is given in cylindrical and spherical geometry. The results obtained are compared with those of earlier models and the differences are analyzed.

  13. Colonization behaviors of mountain pine beetle on novel hosts: Implications for range expansion into northeastern North America.

    Science.gov (United States)

    Rosenberger, Derek W; Venette, Robert C; Maddox, Mitchell P; Aukema, Brian H

    2017-01-01

    As climates change, thermal limits may no longer constrain some native herbivores within their historical ranges. The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a tree-killing bark beetle native to western North America that is currently expanding its range. Continued eastward expansion through the newly invaded and novel jack pine (Pinus banksiana Lamb.) trees of the Canadian boreal forest could result in exposure of several species of novel potential host pines common in northeastern North America to this oligophagous herbivore. Due to the tightly co-evolved relationship between mountain pine beetle and western pine hosts, in which the insect utilizes the defensive chemistry of the host to stimulate mass attacks, we hypothesized that lack of co-evolutionary association would affect the host attraction and acceptance behaviors of this insect among novel hosts, particularly those with little known historical association with an aggressive stem-infesting insect. We studied how beetle behavior differed among the various stages of colonization on newly cut logs of four novel potential pine host species; jack, red (P. resinosa Ait.), eastern white (P. strobus L.) and Scots (P. sylvestris L.) pines, as well as two historical hosts, ponderosa (P. ponderosa Dougl. ex. Laws. var. scopulorum Engelm.) and lodgepole (P. contorta Dougl. var. latifolia Engelm.) pines. Overall, we found that beetle colonization behaviors at each stage in the colonization process differ between pine hosts, likely due to differing chemical and physical bark traits. Pines without co-evolved constitutive defenses against mountain pine beetle exhibited reduced amounts of defensive monoterpenoid chemicals; however, such patterns also reduced beetle attraction and colonization. Neither chemical nor physical defenses fully defended trees against the various stages of host procurement that can result in tree colonization and death.

  14. Host range of symptomatology of Pepino mosaic virus strains occurring in Europe

    DEFF Research Database (Denmark)

    Blystad, Dag-Ragnar; van der Vlugt, René; Alfaro-Fernández, Ana

    2015-01-01

    Pepino mosaic virus (PepMV) has caused great concern in the greenhouse tomato industry after it was found causing a new disease in tomato in 1999. The objective of this paper is to investigate alternative hosts and compare important biological characteristics of the three PepMV strains occurring...... for the three strains tested at 10 different European locations with both international and local cultivars showed that eggplant is an alternative host of PepMV. Sweet pepper is not an important host of PepMV, but potato can be infected when the right isolate is matched with a specific cultivar. Nicotiana...

  15. A three-line lateral flow assay strip for the measurement of C-reactive protein covering a broad physiological concentration range in human sera.

    Science.gov (United States)

    Oh, Young Kyoung; Joung, Hyou-Arm; Han, Hyung Soo; Suk, Ho-Jun; Kim, Min-Gon

    2014-11-15

    The lateral flow assay (LFA) strip sensor possesses many advantages as a diagnostic device, including the capabilities of rapid, one-step assay performance, and high throughput production. A major limitation of the sensor, however, is its difficulty in measuring a broad concentration range of target proteins, including C-reactive protein (CRP), due to the "hook effect." In this study, we report the use of a three-line LFA strip sensor, adding an antigen line to the conventional two-line LFA sensor, for detecting CRP within a broad concentration range in human sera. We introduced an antigen line between test and control lines in the LFA sensor. The antigen line was formed by dispensing a CRP antibody solution followed by a CRP solution in nitrocellulose membrane. All other conditions were identical to those applied to the conventional LFA strip sensor. The CRP level in test samples was generated by data processing from the intensities of three lines. The strip sensor measured a linear detection range of CRP concentration from 1 ng/mL to 500 μg/mL within 10 min, with a calculated detection range of 0.69 ng/mL-1.02 mg/mL. Using the developed three-line LFA sensor, 50 clinical samples were measured at a detection range of 0.4-84.7 μg/mL. This novel and easy-to-use CRP sensor can be a useful tool for rapid, sensitive, and cost-effective detection of a broad physiological concentration range of CRP capabilities that are vital for various diagnostic applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Genetic Diversity and Host Range of Rhizobia Nodulating Lotus tenuis in Typical Soils of the Salado River Basin (Argentina)▿ †

    Science.gov (United States)

    Estrella, María Julia; Muñoz, Socorro; Soto, María José; Ruiz, Oscar; Sanjuán, Juan

    2009-01-01

    A total of 103 root nodule isolates were used to estimate the diversity of bacteria nodulating Lotus tenuis in typical soils of the Salado River Basin. A high level of genetic diversity was revealed by repetitive extragenic palindromic PCR, and 77 isolates with unique genomic fingerprints were further differentiated into two clusters, clusters A and B, after 16S rRNA restriction fragment length polymorphism analysis. Cluster A strains appeared to be related to the genus Mesorhizobium, whereas cluster B was related to the genus Rhizobium. 16S rRNA sequence and phylogenetic analysis further supported the distribution of most of the symbiotic isolates in either Rhizobium or Mesorhizobium: the only exception was isolate BA135, whose 16S rRNA gene was closely related to the 16S rRNA gene of the genus Aminobacter. Most Mesorhizobium-like isolates were closely related to Mesorhizobium amorphae, Mesorhizobium mediterraneum, Mesorhizobium tianshanense, or the broad-host-range strain NZP2037, but surprisingly few isolates grouped with Mesorhizobium loti type strain NZP2213. Rhizobium-like strains were related to Rhizobium gallicum, Rhizobium etli, or Rhizobium tropici, for which Phaseolus vulgaris is a common host. However, no nodC or nifH genes could be amplified from the L. tenuis isolates, suggesting that they have rather divergent symbiosis genes. In contrast, nodC genes from the Mesorhizobium and Aminobacter strains were closely related to nodC genes from narrow-host-range M. loti strains. Likewise, nifH gene sequences were very highly conserved among the Argentinian isolates and reference Lotus rhizobia. The high levels of conservation of the nodC and nifH genes suggest that there was a common origin of the symbiosis genes in narrow-host-range Lotus symbionts, supporting the hypothesis that both intrageneric horizontal gene transfer and intergeneric horizontal gene transfer are important mechanisms for the spread of symbiotic capacity in the Salado River Basin. PMID

  17. Prevalence, Host Range, and Comparative Genomic Analysis of Temperate Ochrobactrum Phages

    Directory of Open Access Journals (Sweden)

    Claudia Jäckel

    2017-06-01

    Full Text Available Ochrobactrum and Brucella are closely related bacteria that populate different habitats and differ in their pathogenic properties. Only little is known about mobile genetic elements in these genera which might be important for survival and virulence. Previous studies on Brucella lysogeny indicated that active phages are rare in this genus. To gain insight into the presence and nature of prophages in Ochrobactrum, temperate phages were isolated from various species and characterized in detail. In silico analyses disclosed numerous prophages in published Ochrobactrum genomes. Induction experiments showed that Ochrobactrum prophages can be induced by various stress factors and that some strains released phage particles even under non-induced conditions. Sixty percent of lysates prepared from 125 strains revealed lytic activity. The host range and DNA similarities of 19 phages belonging to the families Myoviridae, Siphoviridae, or Podoviridae were determined suggesting that they are highly diverse. Some phages showed relationship to the temperate Brucella inopinata phage BiPB01. The genomic sequences of the myovirus POA1180 (41,655 bp and podovirus POI1126 (60,065 bp were analyzed. Phage POA1180 is very similar to a prophage recently identified in a Brucella strain isolated from an exotic frog. The POA1180 genome contains genes which may confer resistance to chromate and the ability to take up sulfate. Phage POI1126 is related to podoviruses of Sinorhizobium meliloti (PCB5, Erwinia pyrifoliae (Pep14, and Burkholderia cenocepacia (BcepIL02 and almost identical to an unnamed plasmid of the Ochrobactrum intermedium strain LMG 3301. Further experiments revealed that the POI1126 prophage indeed replicates as an extrachromosomal element. The data demonstrate for the first time that active prophages are common in Ochrobactrum and suggest that atypical brucellae also may be a reservoir for temperate phages.

  18. Hemoglobin niobate composite based biosensor for efficient determination of hydrogen peroxide in a broad pH range.

    Science.gov (United States)

    Gao, Lu; Gao, Qiuming

    2007-02-15

    Inorganic layered niobates (HCa2Nb3O10) were used as immobilization matrices of hemoglobin (Hb) because of their tunable interlayer spaces, large surface areas and good biocompatibilities. A pair of well-defined, quasi-reversible cycle voltammertric peaks were obtained at the Hb-HCa2Nb3O10 modified pyrolytic graphite electrode, suggesting that the layered niobates facilitate the electron transfer between the proteins and the electrode. Hb-HCa2Nb3O10 modified electrode exhibited electrocatalytic response for monitoring H2O2 with a large linear detection range from 25 microM to 3.0 mM and a relatively high sensitivity of 172 microA mM-1 cm-2. Based on the stabilizing effect of the layered niobates, Hb-HCa2Nb3O10 modified electrode can detect H2O2 in strongly acidic and basic solutions with pH of 1-12, which greatly expands the application fields of biosensors.

  19. Myxobacteria Are Able to Prey Broadly upon Clinically-Relevant Pathogens, Exhibiting a Prey Range Which Cannot Be Explained by Phylogeny

    Directory of Open Access Journals (Sweden)

    Paul G. Livingstone

    2017-08-01

    Full Text Available Myxobacteria are natural predators of microorganisms and the subjects of concerted efforts to identify novel antimicrobial compounds. Myxobacterial predatory activity seems to require more than just the possession of specific antimicrobial metabolites. Thus a holistic approach to studying predation promises novel insights into antimicrobial action. Here, we report the isolation of 113 myxobacteria from samples of soil taken from a range of habitats in mid Wales. Predatory activity of each isolate was quantified against a panel of clinically important prey organisms, including Klebsiella pneumoniae, Proteus mirabilis, Candida albicans, Enterococcus faecalis, and three species of Staphylococcus. Myxobacterial isolates exhibited a wide range of predation activity profiles against the panel of prey. Efficient predation of all prey by isolates within the collection was observed, with K. pneumoniae and C. albicans proving particularly susceptible to myxobacterial predation. Notably efficient predators tended to be proficient at predating multiple prey organisms, suggesting they possess gene(s encoding a broad range killing activity. However, predatory activity was not congruent with phylogeny, suggesting prey range is subject to relatively rapid specialization, potentially involving lateral gene transfer. The broad but patchy prey ranges observed for natural myxobacterial isolates also implies multiple (potentially overlapping genetic determinants are responsible for dictating predatory activity.

  20. Broadly neutralizing influenza hemagglutinin stem-specific antibody CR8020 targets residues that are prone to escape due to host selection pressure.

    Science.gov (United States)

    Tharakaraman, Kannan; Subramanian, Vidya; Cain, David; Sasisekharan, Viswanathan; Sasisekharan, Ram

    2014-05-14

    Broadly neutralizing antibodies (bNAb) that target a conserved region of a viral antigen hold significant therapeutic promise. CR8020 is a bNAb that targets the stem region of influenza A virus (IAV) hemagglutinin (HA). CR8020 is currently being evaluated for prophylactic use against group 2 IAVs in phase II studies. Structural and computational analyses reported here indicate that CR8020 targets HA residues that are prone to antigenic drift and host selection pressure. Critically, CR8020 escape mutation is seen in certain H7N9 viruses from recent outbreaks. Furthermore, the ability of the bNAb Fc region to effectively engage activating Fcγ receptors (FCγR) is essential for antibody efficacy. In this regard, our data indicate that the membrane could sterically hinder the formation of HA-CR8020-FcγRIIa/HA-IgG-FcγRIIIa ternary complexes. Altogether, our analyses suggest that epitope mutability and accessibility to immune complex assembly are important attributes to consider when evaluating bNAb candidates for clinical development. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Characterization of Phytophthora pistaciae, the causal agent of pistachio gummosis, based on host range, morphology, and ribosomal genome

    Directory of Open Access Journals (Sweden)

    Zahra MIRSOLEIMANI

    2014-01-01

    Full Text Available Gummosis is the most important disease of pistachio trees in Iranian pistachio orchards. Phytophthora pistaciae, the main causal agent of this disease, was isolated and described from Kerman province of Iran for the first time. The present study aimed to establish the host range, morphological characteristics and ribosomal genome of P. pistaciae isolates. During 2009–2010, isolates of P. pistaciae were sampled from 12 infected pistachio plantations in Kerman and Yazd provinces of Iran. Based on phylogenetic analysis of ITS regions, all isolates belonged to a monophyletic clade and clustered with P. pistaciae from other studies. The isolates were high temperature tolerant and produced non-papillate, ellipsoid to ovoid sporangia with polar caps, and were non-caducous, sympodial and had internal and external proliferation. The isolates were homothallic and produced spherical oogonia with smooth walls and paragynous, rarely amphigynous, spherical to ovoid antheridia. Oospores were spherical, colorless and aplerotic. Isolates generated chlamydospores in host tissues. The host range of P. pistaciae is not limited to pistachio species. Almond, walnut, apricot, grape, mango, sour cherry, among woody plants, and pea, different types of beans, chickpea, faba bean, safflower and okra, among herbaceous plants, were shown to be potential hosts of the pathogen. This study showed that isolates of P. pistaciae were homogenous in ITS rDNA genome and their host range, and morphological traits were similar. 

  2. Rotylenchulus reniformis on Greenhouse-grown Foliage Plants: Host Range and Sources of Inoculum.

    Science.gov (United States)

    Starr, J L

    1991-10-01

    Two sources of inoculum of reniform nematodes, Rotylenchulus reniformis, were identified for infestation of ornamental foliage plants in commercial greenhouses. These were water from a local canal system and rooted cuttings purchased from other sources. Eight ornamental plant species were identified as good hosts for the reniform nematode, with each species supporting a reniform population density equal to or greater than that supported by 'Rutgers' tomato and a reproduction factor of greater than 1.0. Nine other plant species were identified as poor hosts.

  3. Host range of the European leaf sheath mining midge, Lasioptera donacis Coutin, a biological control of giant reed, Arundo donax

    Science.gov (United States)

    The fundamental host range of the arundo leafminer, Lasioptera donacis a candidate agent for the invasive weed, Arundo donax was evaluated. Lasioptera donacis collects and inserts spores of a saprophytic fungus, Arthrinium arundinis, during oviposition. Larvae feed and develop in the decomposing le...

  4. 'Candidatus Megaira polyxenophila' gen. nov., sp. nov.: considerations on evolutionary history, host range and shift of early divergent rickettsiae.

    Science.gov (United States)

    Schrallhammer, Martina; Ferrantini, Filippo; Vannini, Claudia; Galati, Stefano; Schweikert, Michael; Görtz, Hans-Dieter; Verni, Franco; Petroni, Giulio

    2013-01-01

    "Neglected Rickettsiaceae" (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria.

  5. 'Candidatus Megaira polyxenophila' gen. nov., sp. nov.: considerations on evolutionary history, host range and shift of early divergent rickettsiae.

    Directory of Open Access Journals (Sweden)

    Martina Schrallhammer

    Full Text Available "Neglected Rickettsiaceae" (i.e. those harboured by non-hematophagous eukaryotic hosts display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora; furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta. Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria.

  6. Hierarchical MoS2@MoP core-shell heterojunction electrocatalysts for efficient hydrogen evolution reaction over a broad pH range

    Science.gov (United States)

    Wu, Aiping; Tian, Chungui; Yan, Haijing; Jiao, Yanqing; Yan, Qing; Yang, Guoyu; Fu, Honggang

    2016-05-01

    A low-cost catalyst for the hydrogen evolution reaction (HER) over a broad pH range is highly desired to meet the practical needs in different areas. In this study, hierarchical flower-like MoS2@MoP core-shell heterojunctions (HF-MoSP) are designed as a promising catalyst for HER over a broad pH range. The materials are obtained by the controllable phosphidation of the hierarchical MoS2 flower (HF-MoS2) composed of thin silk belt-like sheets. The phosphidation degree, P/S ratio and work function (WF) of HF-MoSP can be tuned easily over broad range by changing the phosphidation temperature. Under optimized condition, HF-MoSP exhibits excellent electrocatalytic activity for HER with a low onset overpotential of 29 mV and η of 108 mV at 10 mA cm-2 in 0.5 M H2SO4 and retains its good activity for 30 h. In addition, the catalyst shows excellent activity in 1 M KOH with an onset overpotential of 42 mV and η of 119 mV at 10 mA cm-2. The catalysts also exhibit obvious activity in neutral, weak acid and weak alkaline conditions. The good performance is relative to the synergy of the MoP shell and MoS2 core and the high WF of HF-MoSP close to Pt, and the large SBET of HF-MoSP benefited from the hierarchical structure. This study represents the construction of the core-shell heterojunction and provides a new way to provide the low-cost and high-performance catalyst for HER.A low-cost catalyst for the hydrogen evolution reaction (HER) over a broad pH range is highly desired to meet the practical needs in different areas. In this study, hierarchical flower-like MoS2@MoP core-shell heterojunctions (HF-MoSP) are designed as a promising catalyst for HER over a broad pH range. The materials are obtained by the controllable phosphidation of the hierarchical MoS2 flower (HF-MoS2) composed of thin silk belt-like sheets. The phosphidation degree, P/S ratio and work function (WF) of HF-MoSP can be tuned easily over broad range by changing the phosphidation temperature. Under optimized

  7. Comparative genomics of the apicomplexan parasites Toxoplasma gondii and neospora caninum: Coccidia differing in host range and transmission strategy

    KAUST Repository

    Reid, Adam James

    2012-03-22

    Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species.

  8. Comparative genomics of the apicomplexan parasites Toxoplasma gondii and Neospora caninum: Coccidia differing in host range and transmission strategy.

    Directory of Open Access Journals (Sweden)

    Adam James Reid

    Full Text Available Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species.

  9. Fluorescence ratiometric optical broad range pH sensor based on CdSe/ZnS quantum dots and O170 embedded in ethyl cellulose matrix

    Science.gov (United States)

    Chu, Cheng-Shane; Su, Chih-Jen

    2017-04-01

    This paper presents a ratiometric optical broad range pH sensor that comprises an optical fiber coated at one end with CdSe/ZnS quantum dots (QDs) and Oxazine 170 perchlorate (O170) embedded in ethyl cellulose (EC) matrix. The feasibility of coating an optical fiber with the sensing film to fabricate a ratiometric fiber optic broad range pH sensor is investigated. Using an LED with a central wavelength 405 nm as an excitation light source, the CdSe/ZnS QDs shows that the emission wavelength at 575 nm highly sensitive to pH and O170 shows the emission wavelength at 655 nm insensitive to pH. The ratio of fluorescence intensities at 575 nm and 655 nm has a linear relationship with pH in the 0.9-12.2 range. The ratiometric sensing approach presented in this study has the advantage of suppressing spurious fluctuations in the intensity of the excitation source and optical transmission properties of the optical fiber sensor.

  10. Nitrogen-rich functional groups carbon nanoparticles based fluorescent pH sensor with broad-range responding for environmental and live cells applications.

    Science.gov (United States)

    Shi, Bingfang; Su, Yubin; Zhang, Liangliang; Liu, Rongjun; Huang, Mengjiao; Zhao, Shulin

    2016-08-15

    A nitrogen-rich functional groups carbon nanoparticles (N-CNs) based fluorescent pH sensor with a broad-range responding was prepared by one-pot hydrothermal treatment of melamine and triethanolamine. The as-prepared N-CNs exhibited excellent photoluminesence properties with an absolute quantum yield (QY) of 11.0%. Furthermore, the N-CNs possessed a broad-range pH response. The linear pH response range was 3.0 to 12.0, which is much wider than that of previously reported fluorescent pH sensors. The possible mechanism for the pH-sensitive response of the N-CNs was ascribed to photoinduced electron transfer (PET). Cell toxicity experiment showed that the as-prepared N-CNs exhibited low cytotoxicity and excellent biocompatibility with the cell viabilities of more than 87%. The proposed N-CNs-based pH sensor was used for pH monitoring of environmental water samples, and pH fluorescence imaging of live T24 cells. The N-CNs is promising as a convenient and general fluorescent pH sensor for environmental monitoring and bioimaging applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population

    Science.gov (United States)

    Jolles, Anna E.; Ezenwa, Vanessa O.; Smith, Mireya; Steinauer, Michelle L.

    2017-01-01

    Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i) what are the spatial and temporal patterns of schistosome infections; (ii) how do parasite burdens vary over time within individual hosts; and (iii) what host factors (immunological, physiological, co-infection) and environmental factors (season, location) explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates the power of

  12. Host immunity, nutrition and coinfection alter longitudinal infection patterns of schistosomes in a free ranging African buffalo population.

    Directory of Open Access Journals (Sweden)

    Brianna R Beechler

    2017-12-01

    Full Text Available Schistosomes are trematode parasites of global importance, causing infections in millions of people, livestock, and wildlife. Most studies on schistosomiasis, involve human subjects; as such, there is a paucity of longitudinal studies investigating parasite dynamics in the absence of intervention. As a consequence, despite decades of research on schistosomiasis, our understanding of its ecology in natural host populations is centered around how environmental exposure and acquired immunity influence acquisition of parasites, while very little is known about the influence of host physiology, coinfection and clearance in the absence of drug treatment. We used a 4-year study in free-ranging African buffalo to investigate natural schistosome dynamics. We asked (i what are the spatial and temporal patterns of schistosome infections; (ii how do parasite burdens vary over time within individual hosts; and (iii what host factors (immunological, physiological, co-infection and environmental factors (season, location explain patterns of schistosome acquisition and loss in buffalo? Schistosome infections were common among buffalo. Microgeographic structure explained some variation in parasite burdens among hosts, indicating transmission hotspots. Overall, parasite burdens ratcheted up over time; however, gains in schistosome abundance in the dry season were partially offset by losses in the wet season, with some hosts demonstrating complete clearance of infection. Variation among buffalo in schistosome loss was associated with immunologic and nutritional factors, as well as co-infection by the gastrointestinal helminth Cooperia fuelleborni. Our results demonstrate that schistosome infections are surprisingly dynamic in a free-living mammalian host population, and point to a role for host factors in driving variation in parasite clearance, but not parasite acquisition which is driven by seasonal changes and spatial habitat utilization. Our study illustrates

  13. North American tree squirrels and ground squirrels with overlapping ranges host different Cryptosporidium species and genotypes

    Czech Academy of Sciences Publication Activity Database

    Stenger, B.L.S.; Clark, M.E.; Kváč, Martin; Khan, E.; Giddings, C.W.; Prediger, Jitka; McEvoy, J.M.

    2015-01-01

    Roč. 36, 2015-Dec (2015), s. 287-293 ISSN 1567-1348 R&D Projects: GA ČR GA15-01090S Institutional support: RVO:60077344 Keywords : Cryptosporidium * Tree squirrels * Ground squirrels * Host specificity * Zoonotic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.591, year: 2015

  14. Small Ruminant Lentiviruses (SRLVs Break the Species Barrier to Acquire New Host Range

    Directory of Open Access Journals (Sweden)

    Juliano Cezar Minardi da Cruz

    2013-07-01

    Full Text Available Zoonotic events of simian immunodeficiency virus (SIV from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS, one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2, the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV and Maedi-Visna virus (MVV, and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs, affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections

  15. Small ruminant lentiviruses (SRLVs) break the species barrier to acquire new host range.

    Science.gov (United States)

    Minardi da Cruz, Juliano Cezar; Singh, Dinesh Kumar; Lamara, Ali; Chebloune, Yahia

    2013-07-23

    Zoonotic events of simian immunodeficiency virus (SIV) from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2), the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections, in addition to

  16. Expansion of spatial and host range of Puumala virus in Sweden: an increasing threat for humans?

    Science.gov (United States)

    Borg, O; Wille, M; Kjellander, P; Bergvall, U A; Lindgren, P-E; Chirico, J; Lundkvist, Å

    2017-06-01

    Hantaviruses are globally distributed and cause severe human disease. Puumala hantavirus (PUUV) is the most common species in Northern Europe, and the only hantavirus confirmed to circulate in Sweden, restricted to the northern regions of the country. In this study, we aimed to further add to the natural ecology of PUUV in Sweden by investigating prevalence, and spatial and host species infection patterns. Specifically, we wanted to ascertain whether PUUV was present in the natural reservoir, the bank vole (Myodes glareolus) further south than Dalälven river, in south-central Sweden, and whether PUUV can be detected in other rodent species in addition to the natural reservoir. In total, 559 animals were collected at Grimsö (59°43'N; 15°28'E), Sala (59°55'N; 16°36'E) and Bogesund (59°24'N; 18°14'E) in south-central Sweden between May 2013 and November 2014. PUUV ELISA-reactive antibodies were found both in 2013 (22/295) and in 2014 (18/264), and nine samples were confirmed as PUUV-specific by focus reduction neutralization test. Most of the PUUV-specific samples were from the natural host, the bank vole, but also from other rodent hosts, indicating viral spill-over. Finally, we showed that PUUV is present in more highly populated central Sweden.

  17. Novel papillomaviruses in free-ranging Iberian bats: no virus-host co-evolution, no strict host specificity, and hints for recombination.

    Science.gov (United States)

    García-Pérez, Raquel; Ibáñez, Carlos; Godínez, Jose M; Aréchiga, Nidia; Garin, Inazio; Pérez-Suárez, Gonzalo; de Paz, Oscar; Juste, Javier; Echevarría, Juan E; Bravo, Ignacio G

    2014-01-01

    Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus-host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered.

  18. Novel Papillomaviruses in Free-Ranging Iberian Bats: No Virus–Host Co-evolution, No Strict Host Specificity, and Hints for Recombination

    Science.gov (United States)

    García-Pérez, Raquel; Ibáñez, Carlos; Godínez, Jose M.; Aréchiga, Nidia; Garin, Inazio; Pérez-Suárez, Gonzalo; de Paz, Oscar; Juste, Javier; Echevarría, Juan E.; Bravo, Ignacio G.

    2014-01-01

    Papillomaviruses (PVs) are widespread pathogens. However, the extent of PV infections in bats remains largely unknown. This work represents the first comprehensive study of PVs in Iberian bats. We identified four novel PVs in the mucosa of free-ranging Eptesicus serotinus (EserPV1, EserPV2, and EserPV3) and Rhinolophus ferrumequinum (RferPV1) individuals and analyzed their phylogenetic relationships within the viral family. We further assessed their prevalence in different populations of E. serotinus and its close relative E. isabellinus. Although it is frequent to read that PVs co-evolve with their host, that PVs are highly species-specific, and that PVs do not usually recombine, our results suggest otherwise. First, strict virus–host co-evolution is rejected by the existence of five, distantly related bat PV lineages and by the lack of congruence between bats and bat PVs phylogenies. Second, the ability of EserPV2 and EserPV3 to infect two different bat species (E. serotinus and E. isabellinus) argues against strict host specificity. Finally, the description of a second noncoding region in the RferPV1 genome reinforces the view of an increased susceptibility to recombination in the E2-L2 genomic region. These findings prompt the question of whether the prevailing paradigms regarding PVs evolution should be reconsidered. PMID:24391150

  19. Carbon dots with strong excitation-dependent fluorescence changes towards pH. Application as nanosensors for a broad range of pH

    Energy Technology Data Exchange (ETDEWEB)

    Barati, Ali [Faculty of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan (Iran, Islamic Republic of); Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Shamsipur, Mojtaba, E-mail: mshamsipur@yahoo.com [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Abdollahi, Hamid, E-mail: abd@iasbs.ac.ir [Faculty of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan (Iran, Islamic Republic of)

    2016-08-10

    In this study, preparation of novel pH-sensitive N-doped carbon dots (NCDs) using glucose and urea is reported. The prepared NCDs present strong excitation-dependent fluorescence changes towards the pH that is a new behavior from these nanomaterials. By taking advantage of this unique behavior, two separated ratiometric pH sensors using emission spectra of the NCDs for both acidic (pH 2.0 to 8.0) and basic (pH 7.0 to 14.0) ranges of pH are constructed. Additionally, by considering the entire Excitation–Emission Matrix (EEM) of NCDs as analytical signal and using a suitable multivariate calibration method, a broad range of pH from 2.0 to 14.0 was well calibrated. The multivariate calibration method was independent from the concentration of NCDs and resulted in a very low average prediction error of 0.067 pH units. No changes in the predicted pH under UV irradiation (for 3 h) and at high ionic strength (up to 2 M NaCl) indicated the high stability of this pH nanosensor. The practicality of this pH nanosensor for pH determination in real water samples was validated with good accuracy and repeatability. - Highlights: • Novel pH-sensitive carbon dots with strong FL changes towards pH are reported. • Ratiometric FL pH-sensors for both acidic and basic ranges of pH are constructed. • Multivariate calibration methods were used to calibrate a broad range of pH. • Using EEM of carbon dots and ANN, pH from 2.0 to 14.0 was well calibrated. • The pH prediction is stable even at high ionic strength up to 2 M NaCl.

  20. M062 is a host range factor essential for myxoma virus pathogenesis and functions as an antagonist of host SAMD9 in human cells.

    Science.gov (United States)

    Liu, Jia; Wennier, Sonia; Zhang, Leiliang; McFadden, Grant

    2011-04-01

    Myxoma virus (MYXV) M062R is a functional homolog of the C7L family of host range genes from orthopoxviruses. We constructed a targeted M062R-knockout-MYXV (vMyxM062-KO) and characterized its properties in vitro and in vivo. In European rabbits, infection by vMyxM062-KO was completely asymptomatic. The surviving rabbits did not gain full protection against the subsequent lethal-dose challenge with wild-type MYXV. We also looked for cellular tropism defects in a variety of cultured cells. In all of the rabbit cells tested, vMyxM062-KO conducts an abortive infection, although it initiates viral DNA replication. In many, but not all, human cancer cells that are permissive for wild-type MYXV, vMyxM062-KO exhibited a profound replication defect. We categorized human cells tested into two groups: (i) type A, which support productive replication for wild-type MYXV but are unable to produce significant levels of progeny virus by vMyxM062-KO, and (ii) type B, which are permissive to infections by both wild-type MYXV and vMyxM062-KO. Furthermore, using proteomic strategies, we identified sterile α motif domain containing 9 (SAMD9), an interferon-regulated cellular protein implicated in human inflammatory disorders, as a unique host binding partner of M062 in human cells. Significantly, knocking down SAMD9 in type A human cancer cells led to a substantial rescue of vMyxM062-KO infection. In summary, M062 is a novel host range factor that controls productive MYXV replication in rabbit cells and in a wide variety of human cells. M062 also binds and antagonizes cellular SAMD9 in human cells, suggesting that SAMD9 is a novel innate antiviral factor against poxviruses.

  1. M062 Is a Host Range Factor Essential for Myxoma Virus Pathogenesis and Functions as an Antagonist of Host SAMD9 in Human Cells▿ †

    Science.gov (United States)

    Liu, Jia; Wennier, Sonia; Zhang, Leiliang; McFadden, Grant

    2011-01-01

    Myxoma virus (MYXV) M062R is a functional homolog of the C7L family of host range genes from orthopoxviruses. We constructed a targeted M062R-knockout-MYXV (vMyxM062-KO) and characterized its properties in vitro and in vivo. In European rabbits, infection by vMyxM062-KO was completely asymptomatic. The surviving rabbits did not gain full protection against the subsequent lethal-dose challenge with wild-type MYXV. We also looked for cellular tropism defects in a variety of cultured cells. In all of the rabbit cells tested, vMyxM062-KO conducts an abortive infection, although it initiates viral DNA replication. In many, but not all, human cancer cells that are permissive for wild-type MYXV, vMyxM062-KO exhibited a profound replication defect. We categorized human cells tested into two groups: (i) type A, which support productive replication for wild-type MYXV but are unable to produce significant levels of progeny virus by vMyxM062-KO, and (ii) type B, which are permissive to infections by both wild-type MYXV and vMyxM062-KO. Furthermore, using proteomic strategies, we identified sterile α motif domain containing 9 (SAMD9), an interferon-regulated cellular protein implicated in human inflammatory disorders, as a unique host binding partner of M062 in human cells. Significantly, knocking down SAMD9 in type A human cancer cells led to a substantial rescue of vMyxM062-KO infection. In summary, M062 is a novel host range factor that controls productive MYXV replication in rabbit cells and in a wide variety of human cells. M062 also binds and antagonizes cellular SAMD9 in human cells, suggesting that SAMD9 is a novel innate antiviral factor against poxviruses. PMID:21248034

  2. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device.

    Science.gov (United States)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Garty, Guy; Harken, Andrew; Brenner, David J

    2015-09-11

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n)3He and D(d,n)3He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  3. Wide host ranges of herbivorous beetles? Insights from DNA bar coding.

    Directory of Open Access Journals (Sweden)

    Keiko Kishimoto-Yamada

    Full Text Available There are very few studies that have investigated host-specificity among tropical herbivorous insects. Indeed, most of the trophic interactions of herbivorous insects in Southeast Asian tropical rainforests remain unknown, and whether polyphagous feeding is common in the herbivores of this ecosystem has not been determined. The present study employed DNA bar coding to reveal the trophic associations of adult leaf-chewing chrysomelid beetles in a Bornean rainforest. Plant material ingested by the adults was retrieved from the bodies of the insects, and a portion of the chloroplast rbcL sequence was then amplified from this material. The plants were identified at the family level using an existing reference database of chloroplast DNA. Our DNA-based diet analysis of eleven chrysomelid species successfully identified their host plant families and indicated that five beetle species fed on more than two families within the angiosperms, and four species fed on several families of gymnosperms and/or ferns together with multiple angiosperm families. These findings suggest that generalist chrysomelid beetles associated with ecologically and taxonomically distant plants constitute a part of the plant-insect network of the Bornean rainforest.

  4. Roles of host plants in boll weevil range expansion beyond tropical Mesoamerica

    Science.gov (United States)

    New findings on boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), biology and ecology have had repercussions on the current level of understanding about short- and long-range boll weevil dispersal, and range expansion from its original tropical Mesoamerican habitat. The w...

  5. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus via range expansion of Asclepias host plants.

    Directory of Open Access Journals (Sweden)

    Nathan P Lemoine

    Full Text Available Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp. host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in

  6. Climate change may alter breeding ground distributions of eastern migratory monarchs (Danaus plexippus) via range expansion of Asclepias host plants.

    Science.gov (United States)

    Lemoine, Nathan P

    2015-01-01

    Climate change can profoundly alter species' distributions due to changes in temperature, precipitation, or seasonality. Migratory monarch butterflies (Danaus plexippus) may be particularly susceptible to climate-driven changes in host plant abundance or reduced overwintering habitat. For example, climate change may significantly reduce the availability of overwintering habitat by restricting the amount of area with suitable microclimate conditions. However, potential effects of climate change on monarch northward migrations remain largely unknown, particularly with respect to their milkweed (Asclepias spp.) host plants. Given that monarchs largely depend on the genus Asclepias as larval host plants, the effects of climate change on monarch northward migrations will most likely be mediated by climate change effects on Asclepias. Here, I used MaxEnt species distribution modeling to assess potential changes in Asclepias and monarch distributions under moderate and severe climate change scenarios. First, Asclepias distributions were projected to extend northward throughout much of Canada despite considerable variability in the environmental drivers of each individual species. Second, Asclepias distributions were an important predictor of current monarch distributions, indicating that monarchs may be constrained as much by the availability of Asclepias host plants as environmental variables per se. Accordingly, modeling future distributions of monarchs, and indeed any tightly coupled plant-insect system, should incorporate the effects of climate change on host plant distributions. Finally, MaxEnt predictions of Asclepias and monarch distributions were remarkably consistent among general circulation models. Nearly all models predicted that the current monarch summer breeding range will become slightly less suitable for Asclepias and monarchs in the future. Asclepias, and consequently monarchs, should therefore undergo expanded northern range limits in summer months

  7. Aggressiveness and host range of Phoma medicaginis isolated from Medicago species growing in Tunisia

    Directory of Open Access Journals (Sweden)

    Naceur DJEBALI

    2013-05-01

    Full Text Available Aggressiveness of 14 Phoma medicaginis isolates obtained from Medicago truncatula (barrel medic and M. ciliaris (ciliate medic growing in Tunisia was measured after inoculation on leaves and roots of M. truncatula. The ability of one isolate to cause disease on M. sativa (alfalfa, Cicer arietinum (chickpea, Pisum sativum (pea, Lens culinaris (lentil and Phaseolus vulgaris (common bean was also tested. The pathogen caused dark lesions that enlarged and coalesced causing yellowing and premature abscission of leaves, resulting in decreased shoot fresh weight in barrel medic plants. All P. medicaginis isolates infected barrel medic roots causing collar rot, brown root discoloration, yellowing of cotyledons and reduced shoot and root development. The pathogen colonized the cortex and the stele of plants and produced fertile pycnidia on infected roots. Symptoms on leaves allowed for greater discrimination in aggressiveness among isolates in comparison to symptoms on roots. No correlations were observed between the parameters measured on leaves and roots suggesting organ specialization in this pathogen. Phoma medicaginis infected leaves of alfalfa, pea, common bean and chickpea causing necrosis and tissue yellowing at 15 d post inoculation (dpi. Pycnidium production was observed on dead and dying foliar tissues of alfalfa, pea and common bean, but not on chickpea. The pathogen caused symptoms of collar rot and brown root discoloration on alfalfa, chickpea, pea and common bean, but did not cause symptoms on leaves or roots of lentil at 15 dpi. Phoma medicaginis was more pathogenic on barrel medic, the host of origin, in comparison to the other legumes, suggesting that these species are likely to be secondary hosts for this pathogen.

  8. Characterization of 6H-SiC JFET Integrated Circuits Over A Broad Temperature Range from -150 C to +500 C

    Science.gov (United States)

    Neudeck, Philip G.; Krasowski, Michael J.; Chen, Liang-Yu; Prokop, Norman F.

    2009-01-01

    The NASA Glenn Research Center has previously reported prolonged stable operation of simple prototype 6H-SiC JFET integrated circuits (logic gates and amplifier stages) for thousands of hours at +500 C. This paper experimentally investigates the ability of these 6H-SiC JFET devices and integrated circuits to also function at cold temperatures expected to arise in some envisioned applications. Prototype logic gate ICs experimentally demonstrated good functionality down to -125 C without changing circuit input voltages. Cascaded operation of gates at cold temperatures was verified by externally wiring gates together to form a 3-stage ring oscillator. While logic gate output voltages exhibited little change across the broad temperature range from -125 C to +500 C, the change in operating frequency and power consumption of these non-optimized logic gates as a function of temperature was much larger and tracked JFET channel conduction properties.

  9. Host Ranges of Listeria-Specific Bacteriophages from the Turkey Processing Plant Environment in the United States ▿

    Science.gov (United States)

    Kim, Jae-Won; Siletzky, Robin M.; Kathariou, Sophia

    2008-01-01

    Even though at least 400 Listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the Listeria population that becomes established in the plant. In this study, we pursued the isolation of Listeria-specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples were also utilized to isolate Listeria spp. Twelve phages were isolated and classified into three groups in terms of their host range. Of these, nine (group 1) showed a wide host range, including multiple serotypes of Listeria monocytogenes, as well as other Listeria spp. (L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii). The remaining phages mostly infected L. monocytogenes serotype 4b as well as L. innocua, L. ivanovii, and/or L. welshimeri. All but one of the strains of the serotype 4b complex (4b, 4d, 4e) from the processing plant environment could be readily infected by the wide-host-range phages isolated from the environment of the processing plants. However, many strains of other serotypes (1/2a [or 3a] and 1/2b [or 3b]), which represented the majority of L. monocytogenes strains isolated from the environmental samples, were resistant to infection by these phages. Experiments with two phage-resistant strains showed reduced phage adsorption onto the host cells. These findings suggest that phage resistance may be an important component of the ecology of L. monocytogenes in the turkey processing plants. PMID:18791016

  10. Host ranges of Listeria-specific bacteriophages from the turkey processing plant environment in the United States.

    Science.gov (United States)

    Kim, Jae-Won; Siletzky, Robin M; Kathariou, Sophia

    2008-11-01

    Even though at least 400 Listeria phages have been isolated from various sources, limited information is available on phages from the food processing plant environment. Phages in the processing plant environment may play critical roles in determining the Listeria population that becomes established in the plant. In this study, we pursued the isolation of Listeria-specific phages from environmental samples from four turkey processing plants in the United States. These environmental samples were also utilized to isolate Listeria spp. Twelve phages were isolated and classified into three groups in terms of their host range. Of these, nine (group 1) showed a wide host range, including multiple serotypes of Listeria monocytogenes, as well as other Listeria spp. (L. innocua, L. welshimeri, L. seeligeri, and L. ivanovii). The remaining phages mostly infected L. monocytogenes serotype 4b as well as L. innocua, L. ivanovii, and/or L. welshimeri. All but one of the strains of the serotype 4b complex (4b, 4d, 4e) from the processing plant environment could be readily infected by the wide-host-range phages isolated from the environment of the processing plants. However, many strains of other serotypes (1/2a [or 3a] and 1/2b [or 3b]), which represented the majority of L. monocytogenes strains isolated from the environmental samples, were resistant to infection by these phages. Experiments with two phage-resistant strains showed reduced phage adsorption onto the host cells. These findings suggest that phage resistance may be an important component of the ecology of L. monocytogenes in the turkey processing plants.

  11. Investigating the host-range of the rust fungus Puccinia psidii sensu lato across tribes of the family Myrtaceae present in Australia.

    Science.gov (United States)

    Morin, Louise; Aveyard, Ruth; Lidbetter, Jonathan R; Wilson, Peter G

    2012-01-01

    The exotic rust fungus Puccinia psidii sensu lato was first detected in Australia in April 2010. This study aimed to determine the host-range potential of this accession of the rust by testing its pathogenicity on plants of 122 taxa, representative of the 15 tribes of the subfamily Myrtoideae in the family Myrtaceae. Each taxon was tested in two separate trials (unless indicated otherwise) that comprised up to five replicates per taxon and six replicates of a positive control (Syzygium jambos). No visible symptoms were observed on the following four taxa in either trial: Eucalyptus grandis×camaldulensis, E. moluccana, Lophostemon confertus and Sannantha angusta. Only small chlorotic or necrotic flecks without any uredinia (rust fruiting bodies) were observed on inoculated leaves of seven other taxa (Acca sellowiana, Corymbia calophylla 'Rosea', Lophostemon suaveolens, Psidium cattleyanum, P. guajava 'Hawaiian' and 'Indian', Syzygium unipunctatum). Fully-developed uredinia were observed on all replicates across both trials of 28 taxa from 8 tribes belonging to the following 17 genera: Agonis, Austromyrtus, Beaufortia, Callistemon, Calothamnus, Chamelaucium, Darwinia, Eucalyptus, Gossia, Kunzea, Leptospermum, Melaleuca, Metrosideros, Syzygium, Thryptomene, Tristania, Verticordia. In contrast, the remaining 83 taxa inoculated, including the majority of Corymbia and Eucalyptus species, developed a broad range of symptoms, often across the full spectrum, from fully-developed uredinia to no visible symptoms. These results were encouraging as they indicate that some levels of genetic resistance to the rust possibly exist in these taxa. Overall, our results indicated no apparent association between the presence or absence of disease symptoms and the phylogenetic relatedness of taxa. It is most likely that the majority of the thousands of Myrtaceae species found in Australia have the potential to become infected to some degree by the rust, although this wide host range may

  12. A wide host-range metagenomic library from a waste water treatment plant yields a novel alcohol/aldehyde dehydrogenase.

    Science.gov (United States)

    Wexler, Margaret; Bond, Philip L; Richardson, David J; Johnston, Andrew W B

    2005-12-01

    Using DNA obtained from the metagenome of an anaerobic digestor in a waste water treatment plant, we constructed a gene library cloned in the wide host-range cosmid pLAFR3. One cosmid enabled Rhizobium leguminosarum to grow on ethanol as sole carbon and energy source, this being due to the presence of a gene, termed adhEMeta. The AdhEMeta protein most closely resembles the AdhE alcohol dehydrogenase of Clostridium acetobutylicum, where it catalyses the formation of ethanol and butanol in a two-step reductive process. However, cloned adhEMeta did not confer ethanol utilization ability to Escherichia coli or to Pseudomonas aeruginosa, even though it was transcribed in both these hosts. Further, cell-free extracts of E. coli and R. leguminosarum containing cloned adhEMeta had butanol and ethanol dehydrogenase activities when assayed in vitro. In contrast to the well-studied AdhE proteins of C. acetobutylicum and E. coli, the enzyme specified by adhEMeta is not inactivated by oxygen and it enables alcohol to be catabolized. Cloned adhEMeta did, however, confer one phenotype to E. coli. AdhE- mutants of E. coli fail to ferment glucose and introduction of adhEMeta restored the growth of such mutants when grown under fermentative conditions. These observations show that the use of wide host-range vectors enhances the efficacy with which metagenomic libraries can be screened for genes that confer novel functions.

  13. In vitro host range of the Hz-1 nonoccluded virus in insect cell lines.

    Science.gov (United States)

    McIntosh, Arthur H; Grasela, James J; Ignoffo, Carlo M

    2007-01-01

    A total of 13 insect cell lines spanning 4 orders (Lepidoptera, Coleoptera, Diptera, and Homoptera) were tested for their ability to replicate the nonoccluded virus Hz-1. Only the Lepidopteran cell lines supported replication of the virus with TN-CL1 and BCIRL-HZ-AM1 producing the highest titers of 2.4 x 10(8) tissue culture infective dose (TCID)50/ml and 2.0 x 10(8) TCID50/ml, respectively. A codling moth cell line (CP-169) was the only Lepidopteran cell line that did not replicate the virus and transfection of this cell line with Hz-1 DNA failed to replicate the virus. Also, transfection with DNA from a recombinant baculovirus carrying the red fluorescent protein gene (AcMNPVhsp70 Red) was not expressed in CP-169 cells. The replication cycle of Hz-1 in BCIRL-HZ-AM1 cells showed that this virus replicated rapidly starting at 16 h postinoculation (p.i.) and reaching a peak titer of 1.0 x 10(8) TCID50/ml 56 h postinoculation. Hz-1 when compared with several other baculoviruses has the widest in vitro host spectrum.

  14. Dual miRNA targeting restricts host range and attenuates neurovirulence of flaviviruses.

    Directory of Open Access Journals (Sweden)

    Konstantin A Tsetsarkin

    2015-04-01

    Full Text Available Mosquito-borne flaviviruses are among the most significant arboviral pathogens worldwide. Vaccinations and mosquito population control programs remain the most reliable means for flavivirus disease prevention, and live attenuated viruses remain one of the most attractive flavivirus vaccine platforms. Some live attenuated viruses are capable of infecting principle mosquito vectors, as demonstrated in the laboratory, which in combination with their intrinsic genetic instability could potentially lead to a vaccine virus reversion back to wild-type in nature, followed by introduction and dissemination of potentially dangerous viral strains into new geographic locations. To mitigate this risk we developed a microRNA-targeting approach that selectively restricts replication of flavivirus in the mosquito host. Introduction of sequences complementary to a mosquito-specific mir-184 and mir-275 miRNAs individually or in combination into the 3'NCR and/or ORF region resulted in selective restriction of dengue type 4 virus (DEN4 replication in mosquito cell lines and adult Aedes mosquitos. Moreover a combined targeting of DEN4 genome with mosquito-specific and vertebrate CNS-specific mir-124 miRNA can silence viral replication in two evolutionally distant biological systems: mosquitoes and mouse brains. Thus, this approach can reinforce the safety of newly developed or existing vaccines for use in humans and could provide an additional level of biosafety for laboratories using viruses with altered pathogenic or transmissibility characteristics.

  15. Occurrence of Belonolaimus in Sinaloa, Northwestern Mexico: A New Report on Distribution and Host Range.

    Science.gov (United States)

    Mundo-Ocampo, Manuel; Baldwin, J G; Pereira, T J; Camacho-Baez, J R; Armenta-Bojorquez, A D; Camacho-Haro, M; Becker, J O

    2017-03-01

    The present study reports the occurrence of the genus Belonolaimus in the state of Sinaloa, Mexico, associated with native plants (i.e., Ziziphus amole and Stenocereus alamosensis) in a natural coastal ecosystem. Both morphological and molecular approaches were employed to characterize the Sinaloa population. Notwithstanding of some morphological and morphometric variation between Belonolaimus from Sinaloa and other valid species, the characterization indicates that this population might belong to the Belonolaimus longicaudatus species complex. Molecular analyses based on the 28S gene and ITS1-5.8S-ITS2 regions of the ribosomal RNA (rRNA) identified four major clades within Belonolaimus; however, none of the species including B. longicaudatus, B. gracilis, and B. euthychilus were supported as monophyletic; yet monophyly is argued to be a basic requirement of species status. Sequence divergence among different Belonolaimus populations and species varied according to the rRNA dataset (i.e., ITS1-5.8S-ITS2 > 28S > 18S) used, thus showing the importance of using genes with different rates of evolution to estimate species relationships. The fact that Belonolaimus has not been found in other cultivated (including on suitable hosts) areas in Sinaloa and that this population is relatively distant from the common B. longicaudatus groups (i.e., clades A and B) suggests that its appearance was not due to a recent introduction associated with the local agriculture.

  16. Biology and preliminary host range assessment of two potential kudzu biological control agents.

    Science.gov (United States)

    Frye, Matthew J; Hough-Goldstein, Judith; Sun, Jiang-Hua

    2007-12-01

    Two insect species from China, Gonioctena tredecimmaculata (Jacoby) (Coleoptera: Chrysomelidae) and Ornatalcides (Mesalcidodes) trifidus (Pascoe) (Coleoptera: Curculionidae), were studied in quarantine in the United States as potential biological control agents for kudzu, Pueraria montana variety lobata (Willd.) Maesen and S. Almeida. Adults of G. tredecimmaculata were ovoviviparous and reproduced throughout the summer, producing offspring that had an obligate adult diapause. In no-choice tests, adult and larval G. tredecimmaculata rejected most of the plant species tested, but consumed foliage and completed their life cycle on soybean (Glycine max L. Merr.) and on a native woodland plant, hog-peanut (Amphicarpaea bracteata L. Fernald), which are in the same subtribe as kudzu (Glycininae). Insects showed similar responses to field- and greenhouse-grown soybean and kudzu foliage, despite measurable differences in leaf traits: field-grown foliage of both plants had greater leaf toughness, higher total carbon content, higher trichome density, and lower water content than greenhouse foliage. O. trifidus adults also rejected most of the plants tested but fed on and severely damaged potted soybean and hog-peanut plants in addition to kudzu. Further tests in China are needed to determine whether these species will accept nontarget host plants under open-field conditions.

  17. Host Range Restriction of Insect-Specific Flaviviruses Occurs at Several Levels of the Viral Life Cycle.

    Science.gov (United States)

    Junglen, Sandra; Korries, Marvin; Grasse, Wolfgang; Wieseler, Janett; Kopp, Anne; Hermanns, Kyra; León-Juárez, Moises; Drosten, Christian; Kümmerer, Beate Mareike

    2017-01-01

    The genus Flavivirus contains emerging arthropod-borne viruses (arboviruses) infecting vertebrates, as well as insect-specific viruses (ISVs) (i.e., viruses whose host range is restricted to insects). ISVs are evolutionary precursors to arboviruses. Knowledge of the nature of the ISV infection block in vertebrates could identify functions necessary for the expansion of the host range toward vertebrates. Mapping of host restrictions by complementation of ISV and arbovirus genome functions could generate knowledge critical to predicting arbovirus emergence. Here we isolated a novel flavivirus, termed Niénokoué virus (NIEV), from mosquitoes sampled in Côte d'Ivoire. NIEV groups with insect-specific flaviviruses (ISFs) in phylogeny and grows in insect cells but not in vertebrate cells. We generated an infectious NIEV cDNA clone and a NIEV reporter replicon to study growth restrictions of NIEV in comparison to yellow fever virus (YFV), for which the same tools are available. Efficient RNA replication of the NIEV reporter replicon was observed in insect cells but not in vertebrate cells. Initial translation of the input replicon RNA in vertebrate cells was functional, but RNA replication did not occur. Chimeric YFV carrying the envelope proteins of NIEV was recovered via electroporation in C6/36 insect cells but did not infect vertebrate cells, indicating a block at the level of entry. Since the YF/NIEV chimera readily produced infectious particles in insect cells but not in vertebrate cells despite efficient RNA replication, restriction is also determined at the level of assembly/release. Taking the results together, the ability of ISF to infect vertebrates is blocked at several levels, including attachment/entry and RNA replication as well as assembly/release. IMPORTANCE Most viruses of the genus Flavivirus, e.g., YFV and dengue virus, are mosquito borne and transmitted to vertebrates during blood feeding of mosquitoes. Within the last decade, an increasing number

  18. All five host-range variants of Xanthomonas citri carry one pthA homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.

    Science.gov (United States)

    Al-Saadi, Abdulwahid; Reddy, Joseph D; Duan, Yong P; Brunings, Asha M; Yuan, Qiaoping; Gabriel, Dean W

    2007-08-01

    Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and A(w)) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragments that hybridize with pthA, which is essential for the pathogenicity of wide-host-range X. citri group A strain 3213. DNA fragments that hybridized with pthA were cloned from a representative strain from all five groups. Each strain carried one and only one pthA homolog that functionally complemented a knockout mutation of pthA in 3213. Every complementing homolog was of identical size to pthA and carried 17.5 nearly identical, direct tandem repeats, including three new genes from narrow-host-range groups C (pthC), A(w) (pthAW), and A* (pthA*). Every noncomplementing paralog was of a different size; one of these was sequenced from group A* (pthA*-2) and was found to have an intact promoter and full-length reading frame but with 15.5 repeats. None of the complementing homologs nor any of the noncomplementing paralogs conferred avirulence to 3213 on grapefruit or suppressed avirulence of a group A* strain on grapefruit. A knockout mutation of pthC in a group C strain resulted in loss of pathogenicity on lime, but the strain was unaffected in ability to elicit an HR on grapefruit. This pthC- mutant was fully complemented by pthA, pthB, or pthC. Analysis of the predicted amino-acid sequences of all functional pthA homologs and nonfunctional paralogs indicated that the specific sequence of the 17th repeat may be essential for pathogenicity of X. citri on citrus.

  19. Kairomone utilization in the host range evaluation of potential biological control agent Trissolcus japonicus (Hymenoptera: Scelionidae)

    Science.gov (United States)

    The brown marmorated stink bug, Halyomorpha halys, is a highly polyphagous species native to Asia that has become a serious invasive agricultural and nuisance pest across North America. Its ability to feed on over 120 plant species, ranging from field crops and orchard fruit to ornamentals and nativ...

  20. Elevated Norepinephrine may be a Unifying Etiological Factor in the Abuse of a Broad Range of Substances: Alcohol, Nicotine, Marijuana, Heroin, Cocaine, and Caffeine.

    Science.gov (United States)

    Fitzgerald, Paul J

    2013-10-13

    A wide range of commonly abused drugs have effects on the noradrenergic neurotransmitter system, including alterations during acute intoxication and chronic use of these drugs. It is not established, however, that individual differences in noradrenergic signaling, which may be present prior to use of drugs, predispose certain persons to substance abuse. This paper puts forth the novel hypothesis that elevated noradrenergic signaling, which may be raised largely due to genetics but also due to environmental factors, is an etiological factor in the abuse of a wide range of substances, including alcohol, nicotine, marijuana, heroin, cocaine, and caffeine. Data are reviewed for each of these drugs comprising their interaction with norepinephrine during acute intoxication, long-term use, subsequent withdrawal, and stress-induced relapse. In general, the data suggest that these drugs acutely boost noradrenergic signaling, whereas long-term use also affects this neurotransmitter system, possibly suppressing it. During acute withdrawal after chronic drug use, noradrenergic signaling tends to be elevated, consistent with the observation that norepinephrine lowering drugs such as clonidine reduce withdrawal symptoms. Since psychological stress can promote relapse of drug seeking in susceptible individuals and stress produces elevated norepinephrine release, this suggests that these drugs may be suppressing noradrenergic signaling during chronic use or instead elevating it only in reward circuits of the brain. If elevated noradrenergic signaling is an etiological factor in the abuse of a broad range of substances, then chronic use of pharmacological agents that reduce noradrenergic signaling, such as clonidine, guanfacine, lofexidine, propranolol, or prazosin, may help prevent or treat drug abuse in general.

  1. Elevated Norepinephrine may be a Unifying Etiological Factor in the Abuse of a Broad Range of Substances: Alcohol, Nicotine, Marijuana, Heroin, Cocaine, and Caffeine

    Directory of Open Access Journals (Sweden)

    Paul J. Fitzgerald

    2013-01-01

    Full Text Available A wide range of commonly abused drugs have effects on the noradrenergic neurotransmitter system, including alterations during acute intoxication and chronic use of these drugs. It is not established, however, that individual differences in noradrenergic signaling, which may be present prior to use of drugs, predispose certain persons to substance abuse. This paper puts forth the novel hypothesis that elevated noradrenergic signaling, which may be raised largely due to genetics but also due to environmental factors, is an etiological factor in the abuse of a wide range of substances, including alcohol, nicotine, marijuana, heroin, cocaine, and caffeine. Data are reviewed for each of these drugs comprising their interaction with norepinephrine during acute intoxication, long-term use, subsequent withdrawal, and stress-induced relapse. In general, the data suggest that these drugs acutely boost noradrenergic signaling, whereas long-term use also affects this neurotransmitter system, possibly suppressing it. During acute withdrawal after chronic drug use, noradrenergic signaling tends to be elevated, consistent with the observation that norepinephrine lowering drugs such as clonidine reduce withdrawal symptoms. Since psychological stress can promote relapse of drug seeking in susceptible individuals and stress produces elevated norepinephrine release, this suggests that these drugs may be suppressing noradrenergic signaling during chronic use or instead elevating it only in reward circuits of the brain. If elevated noradrenergic signaling is an etiological factor in the abuse of a broad range of substances, then chronic use of pharmacological agents that reduce noradrenergic signaling, such as clonidine, guanfacine, lofexidine, propranolol, or prazosin, may help prevent or treat drug abuse in general.

  2. Molecular diversity of the microsporidium Kneallhazia solenopsae reveals an expanded host range among fire ants in North America.

    Science.gov (United States)

    Ascunce, Marina S; Valles, Steven M; Oi, David H; Shoemaker, Dewayne; Plowes, Robert; Gilbert, Lawrence; LeBrun, Edward G; Sánchez-Arroyo, Hussein; Sanchez-Peña, Sergio

    2010-11-01

    Kneallhazia solenopsae is a pathogenic microsporidium that infects the fire ants Solenopsis invicta and Solenopsis richteri in South America and the USA. In this study, we analyzed the prevalence and molecular diversity of K. solenopsae in fire ants from North and South America. We report the first empirical evidence of K. solenopsae infections in the tropical fire ant, Solenopsis geminata, and S. geminata×Solenopsis xyloni hybrids, revealing an expanded host range for this microsporidium. We also analyzed the molecular diversity at the 16S ribosomal RNA gene in K. solenopsae from the ant hosts S.invicta, S. richteri, S. geminata and S. geminata×S. xyloni hybrids from North America, Argentina and Brazil. We found 22 16S haplotypes. One of these haplotypes (WD_1) appears to be widely distributed, and is found in S. invicta from the USA and S. geminata from southern Mexico. Phylogenetic analyses of 16S sequences revealed that K. solenopsae haplotypes fall into one of two major clades that are differentiated by 2-3%. In some cases, multiple K. solenopsae haplotypes per colony were found, suggesting either an incomplete homogenization among gene copies within the 16S gene cluster or multiple K. solenopsae variants simultaneously infecting host colonies. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Optically Tunable Chiral Plasmonic Guest-Host Cellulose Films Weaved with Long-range Ordered Silver Nanowires.

    Science.gov (United States)

    Chu, Guang; Wang, Xuesi; Chen, Tianrui; Gao, Jianxiong; Gai, Fangyuan; Wang, Yu; Xu, Yan

    2015-06-10

    Plasmonic materials with large chiroptical activity at visible wavelength have attracted considerable attention due to their potential applications in metamaterials. Here we demonstrate a novel guest-host chiral nematic liquid crystal film composed of bulk self-co-assembly of the dispersed plasmonic silver nanowires (AgNWs) and cellulose nanocrystals (CNCs). The AgNWs-CNCs composite films show strong plasmonic optical activities, that are dependent on the chiral photonic properties of the CNCs host medium and orientation of the guest AgNWs. Tunable chiral distribution of the aligned anisotropic AgNWs with long-range order is obtained through the CNCs liquid crystal mediated realignment. The chiral plasmonic optical activity of the AgNWs-CNCs composite films can be tuned by changing the interparticle electrostatic repulsion between the CNCs nanorods and AgNWs. We also observe an electromagnetic energy transfer phenomena among the plasmonic bands of AgNWs, due to the modulation of the photonic band gap of the CNCs host matrix. This facile approach for fabricating chiral macrostructured plasmonic materials with optically tunable property is of interest for a variety of advanced optics applications.

  4. Carotenoid production from n-alkanes with a broad range of chain lengths by the novel species Gordonia ajoucoccus A2(T).

    Science.gov (United States)

    Kim, Jin Ho; Kim, Se Hyeuk; Yoon, Jeong Hoon; Lee, Pyung Cheon

    2014-04-01

    A novel diesel-degrading bacterial strain, A2(T), was isolated from soil that was heavily contaminated with oil. Based on phenotypic, phylogenetic, and DNA analyses, strain A2(T) was identified as a novel species of the genus Gordonia and named Gordonia ajoucoccus A2(T) (KCTC 11900BP and CECT8382). G. ajoucoccus A2(T) is able to synthesize carotenoids and produces mainly γ-carotene and keto-γ-carotene. G. ajoucoccus A2(T) is also capable of assimilating n-alkanes with a broad range of chain lengths (C6, C8-C25). Batch culture of G. ajoucoccus A2(T) in a bioreactor containing 1 % (v/v) hexadecane or 1 % (v/v) commercial diesel yielded 25 mg L⁻¹ and 2.6 mg L⁻¹ of carotenoids, respectively. Gas chromatography/mass spectrometry (GC-MS) analysis of hexadecane and hexane degradation metabolites suggested that G. ajoucoccus A2(T) may possess a terminal oxidation pathway that allows it to utilize n-alkanes and hexane as carbon and energy sources. G. ajoucoccus A2(T) could therefore serve as a good model system for understanding microbial n-alkane degradation pathways. Additionally, the metabolic capabilities of G. ajoucoccus A2(T) suggest potential biotechnological applications, such as the bioproduction of carotenoids from industrial discharge or other sources of n-alkanes.

  5. A cross-sectional study on trans-fatty acids and risk markers of CHD among middle-aged men representing a broad range of BMI

    DEFF Research Database (Denmark)

    Nielsen, Birgit M.; Nielsen, Marie M.; Jakobsen, Marianne U.

    2011-01-01

    Intake of trans-fatty acids (TFA), especially industrially produced TFA (I-TFA), has been associated with the risk of CHD through influence on serum lipid levels. Other causal pathways remain less investigated. In the present cross-sectional study of middle-aged men representing a broad range...... of BMI, the association between intake of TFA, I-TFA and ruminant TFA (R-TFA) and obesity-associated risk markers of CHD was assessed. The study comprised 393 Danish men (median age 49 years) with a median BMI of 28·4 kg/m2. Intake of TFA was estimated based on 7 d dietary records, whereas outcomes...... pressure and insulin homeostasis. Among middle-aged men with a generally low intake of TFA, neither I-TFA nor R-TFA was significantly related to obesity-associated risk markers of CHD. The decreased average intake of I-TFA in Denmark since 1995 is suggested to effectively prevent occurrence of the adverse...

  6. Rapid biodegradation of aflatoxin B1 by metabolites of Fusarium sp. WCQ3361 with broad working temperature range and excellent thermostability.

    Science.gov (United States)

    Wang, Cuiqiong; Li, Zhongyuan; Wang, Hui; Qiu, Haiyan; Zhang, Minghui; Li, Shuang; Luo, Xuegang; Song, Yajian; Zhou, Hao; Ma, Wenjian; Zhang, Tongcun

    2017-03-01

    Contamination of food and feed by aflatoxin B1 (AFB1) poses serious economic and health problems worldwide, so the development of biological methods for effective AFB1 degradation is strongly required. Among three AFB1-degrading microorganisms isolated from moldy peanut, Fusarium sp. WCQ3361 could remove AFB1 extremely effectively, with a degradation ratio of 70.20% after 1 min and 95.38% after 24 h. Its degradation ratio was not much affected by temperature change (0-90 °C) and it also displayed excellent thermostability, maintaining 99.40% residual activity after boiling for 10 min. Since protease K could reduce the AFB1 degradation ratio by 55.15%, it is proposed that the effective component for AFB1 degradation is a protein. The AFB1 degradation ability of Fusarium sp. WCQ3361 was further verified by feed stock detoxification and the MTT test with HepG2 cells. In addition, no degradation products were detected by preliminary liquid chromatography/mass spectrometry, suggesting that AFB1 might be metabolized to products with different chemical characteristics from AFB1. Fusarium sp. WCQ3361 is the first reported AFB1 degradation fungus belonging to the genus Fusarium with broad working temperature range, excellent thermostability and high activity, which provides a potential highly useful solution for dealing with AFB1 contamination in the human diet and animal feed. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  7. Antimicrobial properties of zeolite-X and zeolite-A ion-exchanged with silver, copper, and zinc against a broad range of microorganisms.

    Science.gov (United States)

    Demirci, Selami; Ustaoğlu, Zeynep; Yılmazer, Gonca Altın; Sahin, Fikrettin; Baç, Nurcan

    2014-02-01

    Zeolites are nanoporous alumina silicates composed of silicon, aluminum, and oxygen in a framework with cations, water within pores. Their cation contents can be exchanged with monovalent or divalent ions. In the present study, the antimicrobial (antibacterial, anticandidal, and antifungal) properties of zeolite type X and A, with different Al/Si ratio, ion exchanged with Ag(+), Zn(2+), and Cu(2+) ions were investigated individually. The study presents the synthesis and manufacture of four different zeolite types characterized by scanning electron microscopy and X-ray diffraction. The ion loading capacity of the zeolites was examined and compared with the antimicrobial characteristics against a broad range of microorganisms including bacteria, yeast, and mold. It was observed that Ag(+) ion-loaded zeolites exhibited more antibacterial activity with respect to other metal ion-embedded zeolite samples. The results clearly support that various synthetic zeolites can be ion exchanged with Ag(+), Zn(2+), and Cu(2+) ions to acquire antimicrobial properties or ion-releasing characteristics to provide prolonged or stronger activity. The current study suggested that zeolite formulations could be combined with various materials used in manufacturing medical devices, surfaces, textiles, or household items where antimicrobial properties are required.

  8. Phagocytosis of environmental or metabolic crystalline particles induces cytotoxicity by triggering necroptosis across a broad range of particle size and shape.

    Science.gov (United States)

    Honarpisheh, Mohsen; Foresto-Neto, Orestes; Desai, Jyaysi; Steiger, Stefanie; Gómez, Lidia Anguiano; Popper, Bastian; Boor, Peter; Anders, Hans-Joachim; Mulay, Shrikant R

    2017-11-14

    In crystallopathies, crystals or crystalline particles of environmental and metabolic origin deposit within tissues, induce inflammation, injury and cell death and eventually lead to organ-failure. The NLRP3-inflammasome is involved in mediating crystalline particles-induced inflammation, but pathways leading to cell death are still unknown. Here, we have used broad range of intrinsic and extrinsic crystal- or crystalline particle-sizes and shapes, e.g. calcium phosphate, silica, titanium dioxide, cholesterol, calcium oxalate, and monosodium urate. As kidney is commonly affected by crystallopathies, we used human and murine renal tubular cells as a model system. We showed that all of the analysed crystalline particles induce caspase-independent cell death. Deficiency of MLKL, siRNA knockdown of RIPK3, or inhibitors of necroptosis signaling e.g. RIPK-1 inhibitor necrostatin-1s, RIPK3 inhibitor dabrafenib, and MLKL inhibitor necrosulfonamide, partially protected tubular cells from crystalline particles cytotoxicity. Furthermore, we identify phagocytosis of crystalline particles as an upstream event in their cytotoxicity since a phagocytosis inhibitor, cytochalasin D, prevented their cytotoxicity. Taken together, our data confirmed the involvement of necroptosis as one of the pathways leading to cell death in crystallopathies. Our data identified RIPK-1, RIPK3, and MLKL as molecular targets to limit tissue injury and organ failure in crystallopathies.

  9. Radiometric calibration of optical microscopy and microspectroscopy apparata over a broad spectral range using a special thin-film luminescence standard

    Directory of Open Access Journals (Sweden)

    J. Valenta

    2015-04-01

    Full Text Available Application capabilities of optical microscopes and microspectroscopes can be considerably enhanced by a proper calibration of their spectral sensitivity. We propose and demonstrate a method of relative and absolute calibration of a microspectroscope over an extraordinary broad spectral range covered by two (parallel detection branches in visible and near-infrared spectral regions. The key point of the absolute calibration of a relative spectral sensitivity is application of the standard sample formed by a thin layer of Si nanocrystals with stable and efficient photoluminescence. The spectral PL quantum yield and the PL spatial distribution of the standard sample must be characterized by separate experiments. The absolutely calibrated microspectroscope enables to characterize spectral photon emittance of a studied object or even its luminescence quantum yield (QY if additional knowledge about spatial distribution of emission and about excitance is available. Capabilities of the calibrated microspectroscope are demonstrated by measuring external QY of electroluminescence from a standard poly-Si solar-cell and of photoluminescence of Er-doped Si nanocrystals.

  10. Quantum mechanical free energy profiles with post-quantization restraints: Binding free energy of the water dimer over a broad range of temperatures

    Science.gov (United States)

    Bishop, Kevin P.; Roy, Pierre-Nicholas

    2018-03-01

    Free energy calculations are a crucial part of understanding chemical systems but are often computationally expensive for all but the simplest of systems. Various enhanced sampling techniques have been developed to improve the efficiency of these calculations in numerical simulations. However, the majority of these approaches have been applied using classical molecular dynamics. There are many situations where nuclear quantum effects impact the system of interest and a classical description fails to capture these details. In this work, path integral molecular dynamics has been used in conjunction with umbrella sampling, and it has been observed that correct results are only obtained when the umbrella sampling potential is applied to a single path integral bead post quantization. This method has been validated against a Lennard-Jones benchmark system before being applied to the more complicated water dimer system over a broad range of temperatures. Free energy profiles are obtained, and these are utilized in the calculation of the second virial coefficient as well as the change in free energy from the separated water monomers to the dimer. Comparisons to experimental and ground state calculation values from the literature are made for the second virial coefficient at higher temperature and the dissociation energy of the dimer in the ground state.

  11. Free-ranging Eurasian lynx (Lynx lynx) as host of Toxoplasma gondii in Finland.

    Science.gov (United States)

    Jokelainen, Pikka; Deksne, Gunita; Holmala, Katja; Näreaho, Anu; Laakkonen, Juha; Kojola, Ilpo; Sukura, Antti

    2013-07-01

    We investigated the presence of Toxoplasma gondii infections in Eurasian lynx (Lynx lynx) in Finland by analyzing samples from 337 lynx that were legally hunted during the 2010-2011 season and by performing a retrospective nationwide database search of postmortem toxoplasmosis diagnoses in this species. We detected specific anti-T. gondii IgG antibodies in 290 (86.1%) of the 337 lynx. The method used was a direct agglutination test, and samples positive at the used dilution 1:40 were defined as antibody positive. Older lynx had 14.3 times higher odds of being antibody-positive than did lynx of the presumed age of 7-10 mo, and lynx weighing >15 kg had 16.7 times higher odds of being antibody positive than did those ≤ 15 kg. Lynx from the southwest were more often antibody positive, with an odds ratio 6.3, than lynx from the northeast. None of the 332 fecal samples available was positive for the presence of T. gondii-like oocysts with a quantitative MgSO4 flotation technique, and none of the 167 free-ranging Eurasian lynx examined postmortem by veterinary pathologists from January 2000 to May 2010 had died from toxoplasmosis. Although Finnish lynx were confirmed to commonly encounter T. gondii, we found no evidence of an ongoing contribution to the environmental oocyst burden nor of the lynx dying from the infection.

  12. Isolation and characterization of wide host range lytic bacteriophage AP22 infecting Acinetobacter baumannii.

    Science.gov (United States)

    Popova, Anastasia V; Zhilenkov, Evgeny L; Myakinina, Vera P; Krasilnikova, Valentina M; Volozhantsev, Nikolay V

    2012-07-01

    Acinetobacter baumannii plays a significant role in infecting patients admitted to hospitals. Many A. baumannii infections, including ventilation-associated pneumonia, wound, and bloodstream infections, are common for intensive care and burn units. The ability of the microorganism to acquire resistance to many antibiotics, disinfectants, and dehydration assures its long-term survival in hospital settings. The application of bacteriophages is a potential tool to control A. baumannii infections. Bacteriophage AP22 lytic for A. baumannii was isolated from clinical materials and classified as a member of the Myoviridae family. The phage had an icosahedral head of 64 nm in diameter and a contractile tail of 85-90 nm in length. According to restriction analysis, AP22 had 46-kb double-stranded DNA genome. The phage AP22 exhibited rapid adsorption (> 99% adsorbed in 5 min), a large burst size (240 PFU per cell), and stability to the wide range of pH. The bacteriophage was shown to specifically infect and lyse 68% (89 of 130) genotype-varying multidrug-resistant clinical A. baumannii strains by forming clear zones. Thus, it could be used as a candidate for making up phage cocktails to control A. baumannii-associated nosocomial infections. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  13. Nanohole-based surface plasmon resonance instruments with improved spectral resolution quantify a broad range of antibody-ligand binding kinetics.

    Science.gov (United States)

    Im, Hyungsoon; Sutherland, Jamie N; Maynard, Jennifer A; Oh, Sang-Hyun

    2012-02-21

    We demonstrate an affordable low-noise surface plasmon resonance (SPR) instrument based on extraordinary optical transmission (EOT) in metallic nanohole arrays and quantify a broad range of antibody-ligand binding kinetics with equilibrium dissociation constants ranging from 200 pM to 40 nM. This nanohole-based SPR instrument is straightforward to construct, align, and operate, since it is built around a standard microscope and a portable fiber-optic spectrometer. The measured refractive index resolution of this platform is 3.1 × 10(-6) without on-chip cooling, which is among the lowest reported for SPR sensors based on EOT. This is accomplished via rapid full-spectrum acquisition in 10 ms followed by frame averaging of the EOT spectra, which is made possible by the production of template-stripped gold nanohole arrays with homogeneous optical properties over centimeter-sized areas. Sequential SPR measurements are performed using a 12-channel microfluidic flow cell after optimizing surface modification protocols and antibody injection conditions to minimize mass-transport artifacts. The immobilization of a model ligand, the protective antigen of anthrax on the gold surface, is monitored in real-time with a signal-to-noise ratio of ~860. Subsequently, real-time binding kinetic curves were measured quantitatively between the antigen and a panel of small, 25 kDa single-chain antibodies at concentrations down to 1 nM. These results indicate that nanohole-based SPR instruments have potential for quantitative antibody screening and as a general-purpose platform for integrating SPR sensors with other bioanalytical tools.

  14. Multilayer optics for monochromatic high-resolution X-ray imaging diagnostic in a broad photon energy range from 2 keV to 22 keV

    Energy Technology Data Exchange (ETDEWEB)

    Troussel, Ph., E-mail: philippe.troussel@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Dennetiere, D. [Synchrotron Soleil, L’orme des Merisiers, 91190 Saint-Aubin (France); Maroni, R. [CEA, DAM, DIF, F-91297 Arpajon (France); Høghøj, P.; Hedacq, S. [Xenocs SA, 19, rue François Blumet, F-38360 Sassenage (France); Cibik, L.; Krumrey, M. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany)

    2014-12-11

    The “Commissariat à l’énergie atomique et aux énergies alternatives” (CEA) studies and designs advanced X-ray diagnostics to probe dense plasmas produced at the future Laser MegaJoule (LMJ) facility. Mainly for X-ray imaging with high spatial resolution, different types of multilayer mirrors were developed to provide broadband X-ray reflectance at grazing incidence. These coatings are deposited on two toroidal mirror substrates that are then mounted into a Wolter-type geometry (working at a grazing angle of 0.45°) to realize an X-ray microscope. Non-periodic (depth graded) W/Si multilayer can be used in the broad photon energy range from 2 keV to 22 keV. A third flat mirror can be added for the spectral selection of the microscope. This mirror is coated with a Mo/Si multilayer for which the d-spacing varies in the longitudinal direction to satisfy the Bragg condition within the angular acceptance of the microscope and also to compensate the angular dispersion due to the field of the microscope. We present a study of such a so-called Göbel mirror which was optimized for photon energy of 10.35 keV. The three mirrors were coated using magnetron sputtering technology by Xenocs SA. The reflectance in the entire photon energy range was determined in the laboratory of the Physikalisch-Technische Bundesanstalt (PTB) at the synchrotron radiation facility BESSY II in Berlin.

  15. Structure-based modification of a Clostridium difficile-targeting endolysin affects activity and host range.

    Science.gov (United States)

    Mayer, Melinda J; Garefalaki, Vasiliki; Spoerl, Rebecca; Narbad, Arjan; Meijers, Rob

    2011-10-01

    Endolysin CD27L causes cell lysis of the pathogen Clostridium difficile, a major cause of nosocomial infection. We report a structural and functional analysis of the catalytic activity of CD27L against C. difficile and other bacterial strains. We show that truncation of the endolysin to the N-terminal domain, CD27L1-179, gave an increased lytic activity against cells of C. difficile, while the C-terminal region, CD27L180-270, failed to produce lysis. CD27L1-179 also has increased activity against other bacterial species that are targeted by the full-length protein and in addition was able to lyse some CD27L-insensitive strains. However, CD27L1-179 retained a measure of specificity, failing to lyse a wide range of bacteria. The use of green fluorescent protein (GFP)-labeled proteins demonstrated that both CD27L and CD27L1-179 bound to C. difficile cell walls. The crystal structure of CD27L1-179 confirms that the enzyme is a zinc-dependent N-acetylmuramoyl-l-alanine amidase. A structure-based sequence analysis allowed us to identify four catalytic residues, a proton relay cascade, and a substrate binding pocket. A BLAST search shows that the closest-related amidases almost exclusively target Clostridia. This implied that the catalytic domain alone contained features that target a specific bacterial species. To test this hypothesis, we modified Leu 98 to a Trp residue which is found in an endolysin from a bacteriophage of Listeria monocytogenes (PlyPSA). This mutation in CD27L resulted in an increased activity against selected serotypes of L. monocytogenes, demonstrating the potential to tune the species specificity of the catalytic domain of an endolysin.

  16. An interaction domain in human SAMD9 is essential for myxoma virus host-range determinant M062 antagonism of host anti-viral function.

    Science.gov (United States)

    Nounamo, Bernice; Li, Yibo; O'Byrne, Peter; Kearney, Aoife M; Khan, Amir; Liu, Jia

    2017-03-01

    In humans, deleterious mutations in the sterile α motif domain protein 9 (SAMD9) gene are associated with cancer, inflammation, weakening of the immune response, and developmental arrest. However, the biological function of SAMD9 and its sequence-structure relationships remain to be characterized. Previously, we found that an essential host range factor, M062 protein from myxoma virus (MYXV), antagonized the function of human SAMD9. In this study, we examine the interaction between M062 and human SAMD9 to identify regions that are critical to SAMD9 function. We also characterize the in vitro kinetics of the interaction. In an infection assay, exogenous expression of SAMD9 N-terminus leads to a potent inhibition of wild-type MYXV infection. We reason that this effect is due to the sequestration of viral M062 by the exogenously expressed N-terminal SAMD9 region. Our studies reveal the first molecular insight into viral M062-dependent mechanisms that suppress human SAMD9-associated antiviral function. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Expression levels of the yeast alcohol acetyltransferase genes ATF1, Lg-ATF1, and ATF2 control the formation of a broad range of volatile esters.

    Science.gov (United States)

    Verstrepen, Kevin J; Van Laere, Stijn D M; Vanderhaegen, Bart M P; Derdelinckx, Guy; Dufour, Jean-Pierre; Pretorius, Isak S; Winderickx, Joris; Thevelein, Johan M; Delvaux, Freddy R

    2003-09-01

    Volatile aroma-active esters are responsible for the fruity character of fermented alcoholic beverages such as beer and wine. Esters are produced by fermenting yeast cells in an enzyme-catalyzed intracellular reaction. In order to investigate and compare the roles of the known Saccharomyces cerevisiae alcohol acetyltransferases, Atf1p, Atf2p and Lg-Atf1p, in volatile ester production, the respective genes were either deleted or overexpressed in a laboratory strain and a commercial brewing strain. Subsequently, the ester formation of the transformants was monitored by headspace gas chromatography and gas chromatography combined with mass spectroscopy (GC-MS). Analysis of the fermentation products confirmed that the expression levels of ATF1 and ATF2 greatly affect the production of ethyl acetate and isoamyl acetate. GC-MS analysis revealed that Atf1p and Atf2p are also responsible for the formation of a broad range of less volatile esters, such as propyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate, heptyl acetate, octyl acetate, and phenyl ethyl acetate. With respect to the esters analyzed in this study, Atf2p seemed to play only a minor role compared to Atf1p. The atf1Delta atf2Delta double deletion strain did not form any isoamyl acetate, showing that together, Atf1p and Atf2p are responsible for the total cellular isoamyl alcohol acetyltransferase activity. However, the double deletion strain still produced considerable amounts of certain other esters, such as ethyl acetate (50% of the wild-type strain), propyl acetate (50%), and isobutyl acetate (40%), which provides evidence for the existence of additional, as-yet-unknown ester synthases in the yeast proteome. Interestingly, overexpression of different alleles of ATF1 and ATF2 led to different ester production rates, indicating that differences in the aroma profiles of yeast strains may be partially due to mutations in their ATF genes.

  18. Inactivation of pathogenic viruses by plant-derived tannins: strong effects of extracts from persimmon (Diospyros kaki on a broad range of viruses.

    Directory of Open Access Journals (Sweden)

    Kyoko Ueda

    Full Text Available Tannins, plant-derived polyphenols and other related compounds, have been utilized for a long time in many fields such as the food industry and manufacturing. In this study, we investigated the anti-viral effects of tannins on 12 different viruses including both enveloped viruses (influenza virus H3N2, H5N3, herpes simplex virus-1, vesicular stomatitis virus, Sendai virus and Newcastle disease virus and non-enveloped viruses (poliovirus, coxsachievirus, adenovirus, rotavirus, feline calicivirus and mouse norovirus. We found that extracts from persimmon (Diospyros kaki, which contains ca. 22% of persimmon tannin, reduced viral infectivity in more than 4-log scale against all of the viruses tested, showing strong anti-viral effects against a broad range of viruses. Other tannins derived from green tea, acacia and gallnuts were effective for some of the viruses, while the coffee extracts were not effective for any of the virus. We then investigated the mechanism of the anti-viral effects of persimmon extracts by using mainly influenza virus. Persimmon extracts were effective within 30 seconds at a concentration of 0.25% and inhibited attachment of the virus to cells. Pretreatment of cells with the persimmon extracts before virus infection or post-treatment after virus infection did not inhibit virus replication. Protein aggregation seems to be a fundamental mechanism underlying the anti-viral effect of persimmon tannin, since viral proteins formed aggregates when purified virions were treated with the persimmon extracts and since the anti-viral effect was competitively inhibited by a non-specific protein, bovine serum albumin. Considering that persimmon tannin is a food supplement, it has a potential to be utilized as a safe and highly effective anti-viral reagent against pathogenic viruses.

  19. Evidence for suppression of immunity as a driver for genomic introgressions and host range expansion in races of Albugo candida, a generalist parasite

    DEFF Research Database (Denmark)

    McMullan, Mark; Gardiner, Anastasia; Bailey, Kate

    2015-01-01

    How generalist parasites with wide host ranges can evolve is a central question in parasite evolution. Albugo candida is an obligate biotrophic parasite that consists of many physiological races that each specialize on distinct Brassicaceae host species. By analyzing genome sequence assemblies...

  20. A baseline analysis of the distribution, host-range, and severity of the rust Puccinia Psidii in the Hawaiian islands, 2005-2010

    Science.gov (United States)

    Anderson, Robert C.

    2012-01-01

    Puccinia psidii was first described by Winter (1884) on guava (Psidium guajava L.) in Brazil. The rust is still a major pest of native guava in Brazil and is often referred to as “guava rust” internationally. It is unusual among rust fungi because of its broad and ever-expanding host-range within the Myrtaceae plant family (Simpson et al. 2006). The pathogen is regarded as a major threat to Eucalyptus plantations and other Myrtaceae worldwide (Coutinho et al. 1998, Grgurinovic et al. 2006, Glen et al. 2007). Infections of leaves and meristems are particularly severe on susceptible seedlings, cuttings, young trees, and coppice, causing plants to be stunted and multi-branched, inhibiting normal growth and development, and sometimes causing death to young seedlings (Booth et al. 2000, Rayachhetry et al. 2001). The fungus has expanded its host-range in Brazil, affecting both native and introduced Myrtaceae (Coutinho et al. 1998). Since its discovery in 1884, P. psidii has continually been discovered to have an expanding host-range within the Myrtaceae, affecting hosts throughout much of South and Central America and the Caribbean. Spreading out originally from Brazil in 1884, the fungus has been reported on hosts in the following countries (first record in parentheses): Paraguay (1884), Uruguay (1889), Ecuador (1891), Colombia (1913), Puerto Rico (1913), Cuba (1926), Dominican Republic (1933), Venezuela (1934), Jamaica (1936), Argentina (1946), Dominica (1948), Trinidad and Tobago (1951), Guatemala (1968), United States (Florida; 1977), Mexico (1981), El Salvador (1987), and Costa Rica (1998) (Simpson et al. 2006). It is possible that P. psidii was present in El Salvador and Costa Rica prior to 1980, but was not reported until 1987 and 1998, respectively. Until recently, Puccinia psidii was restricted to the Neotropics, Mexico, and the state of Florida in the United States. While the rust has been present in Florida for over 30 years, only recently has it spread

  1. Is the nestedness of metazoan parasite assemblages of marine fishes from the southeastern Pacific coast a pattern associated with the geographical distributional range of the host?

    Science.gov (United States)

    González, M T; Oliva, M E

    2009-04-01

    Nested structure is a pattern originally described in island biogeography to characterize how a set of species is distributed among a set of islands. In parasite communities, nestedness has been intensively studied among individual fish from a locality. However, nested patterns among parasite assemblages from different host populations (localities) have scarcely been investigated. We recorded the occurrence of parasites in 9 fish species widely distributed along the southeastern Pacific coast to determine whether the ecto- and endoparasite assemblages of marine fishes show a nested structure associated with host distributional range. Nestedness was tested using Brualdi-Sanderson index of discrepancy (BR); and 5 null models incorporated in a 'Nestedness' programme (Ulrich, 2006). The ecto- and endoparasite richness do not show similar patterns of latitudinal gradients among fish hosts, with 33-66% of analysed ectoparasite assemblages, and 25-75% of endoparasite assemblages showing nested structures through the host distributional range. For ectoparasites, species richness gradients and nested structure (when present) might be associated with decreased host densities or could reflect negative environmental conditions in the distributional border of the host species, whereas for endoparasites might be caused by geographical breaks of prey or changes in prey availability (intermediate hosts). The sampled extension of the distributional range of the host species, as well as the lack of specificity of some parasites, could influence the detection of nestedness.

  2. Somatic embryogenesis from seeds in a broad range of Vitis vinifera L. varieties: rescue of true-to-type virus-free plants.

    Science.gov (United States)

    San Pedro, Tània; Gammoudi, Najet; Peiró, Rosa; Olmos, Antonio; Gisbert, Carmina

    2017-11-29

    Somatic embryogenesis is the preferred method for cell to plant regeneration in Vitis vinifera L. However, low frequencies of plant embryo conversion are commonly found. In a previous work we obtained from cut-seeds of a grapevine infected with the Grapevine leafroll associated viruses 1 and 3 (GLRaV-1 and GLRaV-3), high rates of direct regeneration, embryo plant conversion and sanitation. The aim of this study is to evaluate the usefulness of this procedure for regeneration of other grapevine varieties which include some infected with one to three common grapevine viruses (GLRaV-3, Grapevine fanleaf virus (GFLV) and Grapevine fleck virus (GFkV)). As grapevine is highly heterozygous, it was necessary to select from among the virus-free plants those that regenerated from mother tissues around the embryo, (true-to-type). Somatic embryogenesis and plant regeneration were achieved in a first experiment, using cut-seeds from the 14 grapevine varieties Airén, Cabernet Franc, Cabernet Sauvignon, Mencía, Merlot, Monastrell, Petit Verdot, Pinot Blanc (infected by GFLV and GFkV), Pinot Gris, Pinot Meunier, Pinot Noir, Syrah, Tempranillo (infected by GFLV), and Verdil. All regenerated plants were confirmed to be free of GFkV whereas at least 68% sanitation was obtained for GFLV. The SSR profiles of the virus-free plants showed, in both varieties, around 10% regeneration from mother tissue (the same genetic make-up as the mother plant). In a second experiment, this procedure was used to sanitize the varieties Cabernet Franc, Godello, Merlot and Valencí Blanc infected by GLRaV-3, GFkV and/or GFLV. Cut-seeds can be used as explants for embryogenesis induction and plant conversion in a broad range of grapevine varieties. The high regeneration rates obtained with this procedure facilitate the posterior selection of true-to-type virus-free plants. A sanitation rate of 100% was obtained for GFkV as this virus is not seed-transmitted. However, the presence of GLRaV-3 and GFLV in

  3. Comparison of broad range 16S rDNA PCR and conventional blood culture for diagnosis of sepsis in the newborn: a case control study

    Directory of Open Access Journals (Sweden)

    Nakstad Britt

    2009-01-01

    Full Text Available Abstract Background Early onset bacterial sepsis is a feared complication of the newborn. A large proportion of infants admitted to the Neonatal Intensive Care Unit (NICU for suspected sepsis receive treatment with potent systemic antibiotics while a diagnostic workup is in progress. The gold standard for detecting bacterial sepsis is blood culture. However, as pathogens in blood cultures are only detected in approximately 25% of patients, the sensitivity of blood culture is suspected to be low. Therefore, the diagnosis of sepsis is often based on the development of clinical signs, in combination with laboratory tests such as a rise in C – reactive protein (CRP. Molecular assays for the detection of bacterial DNA in the blood represent possible new diagnostic tools for early identification of a bacterial cause. Methods A broad range 16S rDNA polymerase chain reaction (PCR without preincubation was compared to conventional diagnostic work up for clinical sepsis, including BACTEC blood culture, for early determination of bacterial sepsis in the newborn. In addition, the relationship between known risk factors, clinical signs, and laboratory parameters considered in clinical sepsis in the newborn were explored. Results Forty-eight infants with suspected sepsis were included in this study. Thirty-one patients were diagnosed with sepsis, only 6 of these had a positive blood culture. 16S rDNA PCR analysis of blinded blood samples from the 48 infants revealed 10 samples positive for the presence of bacterial DNA. PCR failed to be positive in 2 samples from blood culture positive infants, and was positive in 1 sample where a diagnosis of a non-septic condition was established. Compared to blood culture the diagnosis of bacterial proven sepsis by PCR revealed a 66.7% sensitivity, 87.5% specificity, 95.4% positive and 75% negative predictive value. PCR combined with blood culture revealed bacteria in 35.1% of the patients diagnosed with sepsis

  4. Development and Validation of Broad-Range Qualitative and Clade-Specific Quantitative Molecular Probes for Assessing Mercury Methylation in the Environment.

    Science.gov (United States)

    Christensen, Geoff A; Wymore, Ann M; King, Andrew J; Podar, Mircea; Hurt, Richard A; Santillan, Eugenio U; Soren, Ally; Brandt, Craig C; Brown, Steven D; Palumbo, Anthony V; Wall, Judy D; Gilmour, Cynthia C; Elias, Dwayne A

    2016-10-01

    Two genes, hgcA and hgcB, are essential for microbial mercury (Hg) methylation. Detection and estimation of their abundance, in conjunction with Hg concentration, bioavailability, and biogeochemistry, are critical in determining potential hot spots of methylmercury (MeHg) generation in at-risk environments. We developed broad-range degenerate PCR primers spanning known hgcAB genes to determine the presence of both genes in diverse environments. These primers were tested against an extensive set of pure cultures with published genomes, including 13 Deltaproteobacteria, nine Firmicutes, and nine methanogenic Archaea genomes. A distinct PCR product at the expected size was confirmed for all hgcAB(+) strains tested via Sanger sequencing. Additionally, we developed clade-specific degenerate quantitative PCR (qPCR) primers that targeted hgcA for each of the three dominant Hg-methylating clades. The clade-specific qPCR primers amplified hgcA from 64%, 88%, and 86% of tested pure cultures of Deltaproteobacteria, Firmicutes, and Archaea, respectively, and were highly specific for each clade. Amplification efficiencies and detection limits were quantified for each organism. Primer sensitivity varied among species based on sequence conservation. Finally, to begin to evaluate the utility of our primer sets in nature, we tested hgcA and hgcAB recovery from pure cultures spiked into sand and soil. These novel quantitative molecular tools designed in this study will allow for more accurate identification and quantification of the individual Hg-methylating groups of microorganisms in the environment. The resulting data will be essential in developing accurate and robust predictive models of Hg methylation potential, ideally integrating the geochemistry of Hg methylation to the microbiology and genetics of hgcAB IMPORTANCE: The neurotoxin methylmercury (MeHg) poses a serious risk to human health. MeHg production in nature is associated with anaerobic microorganisms. The recent

  5. Zoospore chemotaxis of closely related legume‐root infecting Phytophthora species towards host isoflavones

    National Research Council Canada - National Science Library

    Hosseini, S; Heyman, F; Olsson, U; Broberg, A; Funck Jensen, D; Karlsson, M

    2014-01-01

    .... Phytophthora niederhauserii is considered to have a broad host range. Zoospores of some P hytophthora species are chemotactically attracted to the isoflavones that are secreted by their host plants...

  6. Tick-Host Range Adaptation: Changes in Protein Profiles in Unfed Adult Ixodes scapularis and Amblyomma americanum Saliva Stimulated to Feed on Different Hosts

    Directory of Open Access Journals (Sweden)

    Lucas Tirloni

    2017-12-01

    Full Text Available Understanding the molecular basis of how ticks adapt to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD epidemiology. There is evidence that ticks differentially express specific sets of genes when stimulated to start feeding. This study was initiated to investigate if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to prepare for feeding. We exposed I. scapularis and A. americanum to feeding stimuli of different hosts (rabbit, human, and dog by keeping unfed adult ticks enclosed in a perforated microfuge in close contact with host skin, but not allowing ticks to attach on host. Our data suggest that ticks of the same species differentially express tick saliva proteins (TSPs when stimulated to start feeding on different hosts. SDS-PAGE and silver staining analysis revealed unique electrophoretic profiles in saliva of I. scapularis and A. americanum that were stimulated to feed on different hosts: rabbit, human, and dog. LC-MS/MS sequencing and pairwise analysis demonstrated that I. scapularis and A. americanum ticks expressed unique protein profiles in their saliva when stimulated to start feeding on different hosts: rabbit, dog, or human. Specifically, our data revealed TSPs that were unique to each treatment and those that were shared between treatments. Overall, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes including: secreted conserved proteins (unknown functions, proteinase inhibitors, lipocalins, extracellular matrix/cell adhesion, heme/iron metabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of research on vaccines against Rhipicephalus microplus, which its natural host, cattle, research on vaccine against other ticks relies feeding ticks

  7. Capripoxvirus G-protein-coupled chemokine receptor: a host-range gene suitable for virus animal origin discrimination.

    Science.gov (United States)

    Le Goff, Christian; Lamien, Charles Euloge; Fakhfakh, Emna; Chadeyras, Amélie; Aba-Adulugba, Elexpeter; Libeau, Geneviève; Tuppurainen, Eeva; Wallace, David B; Adam, Tajelser; Silber, Roland; Gulyaz, Vely; Madani, Hafsa; Caufour, Philippe; Hammami, Salah; Diallo, Adama; Albina, Emmanuel

    2009-08-01

    The genus Capripoxvirus within the family Poxviridae comprises three closely related viruses, namely goat pox, sheep pox and lumpy skin disease viruses. This nomenclature is based on the animal species from which the virus was first isolated, respectively, goat, sheep and cattle. Since capripoxviruses are serologically identical, their specific identification relies exclusively on the use of molecular tools. We describe here the suitability of the G-protein-coupled chemokine receptor (GPCR) gene for use in host-range grouping of capripoxviruses. The analysis of 58 capripoxviruses showed three tight genetic clusters consisting of goat pox, sheep pox and lumpy skin disease viruses. However, a few discrepancies exist with the classical virus-host origin nomenclature: a virus isolated from sheep is grouped in the goat poxvirus clade and vice versa. Intra-group diversity was further observed for the goat pox and lumpy skin disease virus isolates. Despite the presence of nine vaccine strains, no genetic determinants of virulence were identified on the GPCR gene. For sheep poxviruses, the addition or deletion of 21 nucleic acids (7 aa) was consistently observed in the 5' terminal part of the gene. Specific signatures for each cluster were also identified. Prediction of the capripoxvirus GPCR topology, and its comparison with other known mammalian GPCRs and viral homologues, revealed not only a classical GPCR profile in the last three-quarters of the protein but also unique features such as a longer N-terminal end with a proximal hydrophobic alpha-helix and a shorter serine-rich C-tail.

  8. Broad-spectrum inhibition of common respiratory RNA viruses by a pyrimidine synthesis inhibitor with involvement of the host antiviral response.

    Science.gov (United States)

    Cheung, Nam Nam; Lai, Kin Kui; Dai, Jun; Kok, Kin Hang; Chen, Honglin; Chan, Kwok-Hung; Yuen, Kwok-Yung; Kao, Richard Yi Tsun

    2017-05-01

    Our previous screening of 50 240 structurally diverse compounds led to the identification of 39 influenza A virus infection inhibitors (Kao R.Y., Yang D., Lau L.S., Tsui W.H., Hu L. et al. Nat Biotechnol 2010;28:600-605). Further screening of these compounds against common respiratory viruses led to the discovery of compound FA-613. This inhibitor exhibited low micromolar antiviral activity against various influenza A and B virus strains, including the highly pathogenic influenza A strains H5N1 and H7N9, enterovirus A71, respiratory syncytial virus, human rhinovirus A, SARS- and MERS-coronavirus. No significant cellular toxicity was observed at the effective concentrations. Animal studies showed an improved survival rate in BALB/c mice that received intranasal FA-613 treatments against a lethal dose infection of A/HK/415742Md/2009 (H1N1). Further cell-based assays indicated that FA-613 interfer with the de novo pyrimidine biosynthesis pathway by targeting the dihydroorotate dehydrogenase. Surprisingly, FA-613 lost its antiviral potency in the interferon-deficient Vero cell line, while maintaining its inhibitory activity in an interferon-competent cell line which showed elevated expression of host antiviral genes when infected in the presence of FA-613. Further investigation of the specific connection between pyrimidine synthesis inhibition and the induction of host innate immunity might aid clinical development of this type of drug in antiviral therapies. Therefore, in acute cases of respiratory tract infections, when rapid diagnostics of the causative agent are not readily available, an antiviral drug with properties like FA-613 could prove to be very valuable.

  9. The secreted Candida albicans protein Pra1 disrupts host defense by broadly targeting and blocking complement C3 and C3 activation fragments.

    Science.gov (United States)

    Luo, Shanshan; Dasari, Prasad; Reiher, Nadine; Hartmann, Andrea; Jacksch, Susanne; Wende, Elisabeth; Barz, Dagmar; Niemiec, Maria Joanna; Jacobsen, Ilse; Beyersdorf, Niklas; Hünig, Thomas; Klos, Andreas; Skerka, Christine; Zipfel, Peter F

    2018-01-01

    Candida albicans the most frequently isolated clinical fungal pathogen can cause local as well as systemic and life-threatening infections particularly in immune-compromised individuals. A better and more detailed understanding how C. albicans evades human immune attack is therefore needed for identifying fungal immune-evasive proteins and develop new therapies. Here, we identified Pra1, the pH-regulated C. albicans antigen as a hierarchical complement inhibitor that targets C3, the central human complement component. Pra1 cleaved C3 at a unique site and further inhibited effector function of the activation fragments. The newly formed C3a-like peptide lacked the C-terminal arginine residue needed for C3a-receptor binding and activation. Moreover, Pra1 also blocked C3a-like antifungal activity as shown in survival assays, and the C3b-like molecule formed by Pra1 was degraded by the host protease Factor I. Pra1 also bound to C3a and C3b generated by human convertases and blocked their effector functions, like C3a antifungal activity shown by fungal survival, blocked C3a binding to human C3a receptor-expressing HEK cells, activation of Fura2-AM loaded cells, intracellular Ca2+ signaling, IL-8 release, C3b deposition, as well as opsonophagocytosis and killing by human neutrophils. Thus, upon infection C. albicans uses Pra1 to destroy C3 and to disrupt host complement attack. In conclusion, candida Pra1 represents the first fungal C3-cleaving protease identified and functions as a fungal master regulator of innate immunity and as a central fungal immune-escape protein. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Ecology of gastropod and bighorn sheep hosts of lungworm on isolated, semiarid mountain ranges in Utah, USA.

    Science.gov (United States)

    Rogerson, Jared D; Fairbanks, W Sue; Cornicelli, Louis

    2008-01-01

    Isolated, nonmigratory populations of bighorn sheep (Ovis canadensis) may experience high exposure to lungworms (Protostrongylus spp.) through a build-up of fecal material. However, semiarid climates may hinder lungworm transmission by limiting terrestrial gastropods, the intermediate hosts. We assessed potential for lungworm transmission, documented occurrence of transmission, and identified habitat types where transmission was likely to occur on ranges of two recently introduced populations of bighorn sheep in northern Utah. Gastropods were collected weekly on Antelope Island and the Newfoundland Mountains, May-August 2001-02, from each of the four major habitat types (riparian, rock, desert shrub, and grass). Distribution of 113 bighorn sheep groups was observed, and 421 fecal pellet groups were collected to estimate lungworm levels. A total of 1,595 gastropods representing five genera were collected from both ranges. Vallonia made up 85% of all gastropods collected. Of 980 gastropods collected on Antelope Island in 2002, only Vallonia were found infected with protostrongylid-type larvae (10 of 980=1%). Lungworm prevalence in bighorn fecal samples was 97% on Antelope Island and 90% on the Newfoundland Mountains. Lungworm prevalence in lambs indicated lungworm transmission was occurring on Antelope Island. Lungworm transmission was likely occurring in riparian habitat due to abundant gastropods, presence of infected gastropods, and reliance by bighorn sheep on few water sources. Differences in spatial distribution between ram and nursery groups may partly explain higher fecal larvae counts in nursery than in ram groups. We suggest lungworm levels in bighorn sheep on semiarid ranges may increase in dry years as bighorn sheep concentrate use on fewer perennial water sources.

  11. Broad-host-range shuttle vectors for screening of regulated promoter activity in viridans group streptococci : Isolation of a pH-regulated promoter

    NARCIS (Netherlands)

    Vriesema, AJM; Brinkman, René; Kok, J; Zaat, SAJ; Vriesema, Aldwin J.M.; Zaat, Sebastian A.J.

    Viridans group streptococci are major constituents of the normal human oral flora and are also identified as the predominant pathogenic bacteria in native valve infective endocarditis. Little information is available regarding the regulation of gene expression in viridans group streptococci, either

  12. Analysis of the multimer resolution system encoded by the parCBA operon of broad-host-range plasmid RP4

    DEFF Research Database (Denmark)

    Eberl, Leo; Sternberg, Claus; Givskov, Michael Christian

    1994-01-01

    specific sites situated in the promoter region of the parCBA operon. The two ParA proteins that are produced as a result of independent translation initiation at two different start codons within the same open reading frame were overexpressed in Escherichia coli and partially purified. Both forms...

  13. Colonization of Barley by the Broad-Host Hemibiotrophic Pathogen Phytophthora palmivora Uncovers a Leaf Development-Dependent Involvement of Mlo.

    Science.gov (United States)

    Le Fevre, Ruth; O'Boyle, Bridget; Moscou, Matthew J; Schornack, Sebastian

    2016-05-01

    The discovery of barley Mlo demonstrated that filamentous pathogens rely on plant genes to achieve entry and lifecycle completion in barley leaves. While having a dramatic effect on foliar pathogens, it is unclear whether overlapping or distinct mechanisms affect filamentous pathogen infection of roots. To remove the bias connected with using different pathogens to understand colonization mechanisms in different tissues, we have utilized the aggressive hemibiotrophic oomycete pathogen Phytophthora palmivora. P. palmivora colonizes root as well as leaf tissues of barley (Hordeum vulgare). The infection is characterized by a transient biotrophy phase with formation of haustoria. Barley accessions varied in degree of susceptibility, with some accessions fully resistant to leaf infection. Notably, there was no overall correlation between degree of susceptibility in roots compared with leaves, suggesting that variation in different genes influences host susceptibility above and below ground. In addition, a developmental gradient influenced infection, with more extensive colonization observed in mature leaf sectors. The mlo5 mutation attenuates P. palmivora infection but only in young leaf tissues. The barley-P. palmivora interaction represents a simple system to identify and compare genetic components governing quantitative colonization in diverse barley tissue types.

  14. During readaptation in vivo, a tissue culture-adapted strain of feline immunodeficiency virus reverts to broad neutralization resistance at different times in individual hosts but through changes at the same position of the surface glycoprotein.

    Science.gov (United States)

    Bendinelli, M; Pistello, M; Del Mauro, D; Cammarota, G; Maggi, F; Leonildi, A; Giannecchini, S; Bergamini, C; Matteucci, D

    2001-05-01

    The broad resistance to antibody-mediated neutralization of lentiviruses recently isolated from infected hosts is a poorly understood feature which might contribute to the ability of these viruses to persist and to the failure of experimental vaccines to protect against virulent viruses. We studied the underlying molecular mechanisms by examining the evolution of a neutralization-sensitive, tissue culture-adapted strain of feline immunodeficiency virus upon reinoculation into specific-pathogen-free cats. Reversion to broad neutralization resistance was observed in seven of seven inoculated animals and, in individual hosts, started to develop between less than 4 and more than 15 months from infection. After comparison of the envelope sequences of the inoculum virus, of an additional 4 neutralization-sensitive in vitro variants, and of 14 ex vivo-derived variants (6 neutralization sensitive, 5 resistant, and 3 with intermediate phenotype), a Lys-->Asn or -->Glu change at position 481 in the V4 region of the surface glycoprotein appeared as a key player in the reversion. This conclusion was confirmed by mutagenesis of molecularly cloned virus. Analysis of viral quasispecies and biological clones showed that the intermediate phenotype was due to transient coexistence of neutralization-sensitive and -resistant variants. Since the amino acid position involved was the same in four of four recent revertants, it is suggested that the number of residues that control reversion to broad neutralization resistance in FIV might be very limited. Amino acid 481 was found to be changed only in one of three putative long-term revertants. These variants shared a Ser-->Asn change at position 557 in region V5, which probably collaborated with other mutations in long-term maintenance of neutralization resistance, as suggested by the study of mutagenized virus.

  15. Host Range of a Population of Pratylenchus vulnus in Commercial Fruit, Nut, Citrus, and Grape Rootstocks in Spain.

    Science.gov (United States)

    Pinochet, J; Verdejo, S; Soler, A; Canals, J

    1992-12-01

    In a host-range study carried out under greenhouse conditions, a total of 37 commercial fruit tree, grape, and citrus rootstocks were tested for their reaction to a population of the lesion nematode, Pratylenchus vulnus, in Spain. Twenty-five rootstocks had a Pf/Pi > 1.5. These included almond (Desmayo Rojo, 1143), apple (EM-9, EM-106), avocado (Hass), cherry (Santa Lucia 64, Camil, M x M 14, Masto de Montafiana), grape (41-B, Fercal, Ritcher 110), hazelnut (Pauetet), loquat (Nadal), peach (Montclar, GF-305), pear (OHF-333), pistachio (P. atlantica, P. vera, P. terebinthus), plum (San Julian 655-2, Montizo, Pixy, Myrobalan 605), and walnut (Serf). The peach rootstock Nemaguard and the grape 161-49 had Pf/Pi between 1.0 and 1.5 (slightly higher than inoculation level). All the tested citrus (Alemow, rough lemon, Carrizo citrange, sour orange, Troyer citrange, Citrumelo), plus three grape (SO4, Vitis rupestris, 1103-P), and the olive rootstock Arbequina had a Pf/Pi < 1.0.

  16. Inhibition of human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1) infectivity with a broad range of lectins

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Vestergaard, B F

    1991-01-01

    Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV infe......-1 infection, the most potent inhibition was found with the lectin HPA. These results indicate that lectins may have a broad antiviral effect on enveloped viruses only limited by types of oligosaccharides present on individual viruses....

  17. The roles of ecological fitting, phylogeny and physiological equivalence in understanding realized and fundamental host ranges in endoparasitoid wasps.

    Science.gov (United States)

    Harvey, J A; Ximénez de Embún, M G; Bukovinszky, T; Gols, R

    2012-10-01

    Co-evolutionary theory underpins our understanding of interactions in nature involving plant-herbivore and host-parasite interactions. However, many studies that are published in the empirical literature that have explored life history and development strategies between endoparasitoid wasps and their hosts are based on species that have no evolutionary history with one another. Here, we investigated novel associations involving two closely related solitary endoparasitoids that originate from Europe and North America and several of their natural and factitious hosts from both continents. The natural hosts of both species are also closely related, all being members of the same family. We compared development and survival of both parasitoids on the four host species and predicted that parasitoid performance is better on their own natural hosts. In contrast with this expectation, survival, adult size and development time of both parasitoids were similar on all (with one exception) hosts, irrespective as to their geographic origin. Our results show that phylogenetic affinity among the natural and factitious hosts plays an important role in their nutritional suitability for related parasitoids. Evolved traits in parasitoids, such as immune suppression and development, thus enable them to successfully develop in novel host species with which they have no evolutionary history. Our results show that host suitability for specialized organisms like endoparasitoids is closely linked with phylogenetic history and macro-evolution as well as local adaptation and micro-evolution. We argue that the importance of novel interactions and 'ecological fitting' based on phylogeny is a greatly underappreciated concept in many resource-consumer studies. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

  18. The response to selection for broad male response to female sex pheromone and its implications for divergence in close-range mating behavior in the European corn borer moth, Ostrinia nubilalis.

    Science.gov (United States)

    Droney, David C; Musto, Callie J; Mancuso, Katie; Roelofs, Wendell L; Linn, Charles E

    2012-12-01

    Coordinated sexual communication systems, seen in many species of moths, are hypothesized to be under strong stabilizing natural selection. Stabilized communication systems should be resistant to change, but there are examples of species/populations that show great diversification. A possible solution is that it is directional sexual selection on variation in male response that drives evolution. We tested a component of this model by asking whether 'rare' males (ca. 5 % of all males in a population) of the European corn borer moth (ECB), Ostrinia nubilalis, that respond to the sex pheromones of both ECB and a different Ostrinia species (O. furnacalis, the Asian corn borer, ACB), might play an important role in diversification. We specifically tested, via artificial selection, whether this broad male response has an evolvable genetic component. We increased the frequency of broad male response from 5 to 70 % in 19 generations, showing that broad-responding males could be important for the evolution of novel communication systems in ECB. We did not find a broader range of mating acceptance of broad males by females of the base population, however, suggesting that broad response would be unlikely to increase in frequency without the involvement of other factors. However, we found that ECB selection-line females accepted a broader range of courting males, including those of ACB, than did females of the base population. Thus, a genetic correlation exists between broad, long-range response to female sex pheromone and the breadth of female acceptance of males at close range. These results are discussed in the context of evolution of novel communication systems in Ostrinia.

  19. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador

    Science.gov (United States)

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C. Miguel; Vallejo, Gustavo A.

    2015-01-01

    Abstract Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(−)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru. PMID:26645579

  20. Prevalence, Genetic Characterization, and 18S Small Subunit Ribosomal RNA Diversity of Trypanosoma rangeli in Triatomine and Mammal Hosts in Endemic Areas for Chagas Disease in Ecuador.

    Science.gov (United States)

    Ocaña-Mayorga, Sofia; Aguirre-Villacis, Fernanda; Pinto, C Miguel; Vallejo, Gustavo A; Grijalva, Mario J

    2015-12-01

    Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador. This study reports infection with T. rangeli in 18 genera of mammal hosts and five species of triatomines in three environments (domestic, peridomestic, and sylvatic). Higher infection rates were found in the sylvatic environment, in close association with Rhodnius ecuadoriensis. The results of this study extend the range of hosts infected with this parasite and the geographic range of the T. rangeli genotype KP1(-)/lineage C in South America. It was not possible to detect variation on T. rangeli from the central coastal region and southern Ecuador with the analysis of the small subunit ribosomal RNA (SSU-rRNA) gene, even though these areas are ecologically different and a phenotypic subdivision of R. ecuadoriensis has been found. R. ecuadoriensis is considered one of the most important vectors for Chagas disease transmission in Ecuador due to its wide distribution and adaptability to diverse environments. An extensive knowledge of the trypanosomes circulating in this species of triatomine, and associated mammal hosts, is important for delineating transmission dynamics and preventive measures in the endemic areas of Ecuador and Northern Peru.

  1. Recent host range expansion of canine distemper virus and variation in its receptor, the signaling lymphocyte activation molecule, in carnivores.

    Science.gov (United States)

    Ohishi, Kazue; Suzuki, Rintaro; Maeda, Taro; Tsuda, Miwako; Abe, Erika; Yoshida, Takao; Endo, Yasuyuki; Okamura, Maki; Nagamine, Takashi; Yamamoto, Hanae; Ueda, Miya; Maruyama, Tadashi

    2014-07-01

    The signaling lymphocyte activation molecule (SLAM) is a receptor for morbilliviruses. To understand the recent host range expansion of canine distemper virus (CDV) in carnivores, we determined the nucleotide sequences of SLAMs of various carnivores and generated three-dimensional homology SLAM models. Thirty-four amino acid residues were found for the candidates binding to CDV on the interface of the carnivore SLAMs. SLAM of the domestic dog (Canis lupus familiaris) were similar to those of other members of the suborder Caniformia, indicating that the animals in this group have similar sensitivity to dog CDV. However, they were different at nine positions from those of felids. Among the nine residues, four of domestic cat (Felis catus) SLAM (72, 76, 82, and 129) and three of lion (Panthera leo persica) SLAM (72, 82, and 129) were associated with charge alterations, suggesting that the felid interfaces have lower affinities to dog CDV. Only the residue at 76 was different between domestic cat and lion SLAM interfaces. The domestic cat SLAM had threonine at 76, whereas the lion SLAM had arginine, a positively charged residue like that of the dog SLAM. The cat SLAM with threonine is likely to have lower affinity to CDV-H and to confer higher resistance against dog CDV. Thus, the four residues (72, 76, 82, and 129) on carnivore SLAMs are important for the determination of affinity and sensitivity with CDV. Additionally, the CDV-H protein of felid strains had a substitution of histidine for tyrosine at 549 of dog CDV-H and may have higher affinity to lion SLAM. Three-dimensional model construction is a new risk assessment method of morbillivirus infectivity. Because the method is applicable to animals that have no information about virus infection, it is especially useful for morbillivirus risk assessment and wildlife conservation.

  2. The biology and preliminary host range of Megacopta cribraria (Heteroptera: Plataspidae) and its impact on kudzu growth.

    Science.gov (United States)

    Zhang, Yanzhuo; Hanula, James L; Horn, Scott

    2012-02-01

    The bean plataspid, Megacopta cribraria (F.), recently was discovered in the United States feeding on kudzu, Pueraria montana Lour. (Merr.) variety lobata (Willd.), an economically important invasive vine. We studied its biology on kudzu and its impact on kudzu growth. We also tested its ability to use other common forest legumes for oviposition and development. Flight intercept traps operated from 17 May 2010 to 31 May 2011 in a kudzu field near Athens, GA showed three peaks of adult flight activity suggesting there are two generations per year on kudzu. Vine samples examined for eggs from April 2010 to April 2011 and June to October 2011 showed two periods of oviposition activity in 2010, which coincided with the peaks in adult activity. In 2011, the second period of oviposition began on or before 24 June and then egg abundance declined gradually thereafter until late August when we recovered <2 eggs/0.5 m of vine. Samples of the five nymphal instars and adults on vines did not show similar trends in abundance. Adults did not lay eggs on the various legume species tested in 2010 in a no-choice test possibly because the cages were too small. In the 2011 field host range experiments conducted in a kudzu field by using 12 legume species, M. cribraria preferentially oviposited on kudzu over soybean, Glycine max Merrill., but they still laid 320 eggs per plant on soybean. Lespedeza hirta (L.) Hornem. and Lespedeza cuneata (Dum. Cours.) G. Don had 122.2 and 108.4 eggs per plant, respectively. Kudzu and soybean were the only species M. cribraria completed development on. Plots protected from M. cribraria feeding by biweekly insecticide applications had 32.8% more kudzu biomass than unprotected plots. Our results show that M. cribraria has a significant impact on kudzu growth and could help suppress this pest weed.

  3. Six host-range restricted poxviruses from three genera induce distinct gene expression profiles in an in vivo mouse model

    National Research Council Canada - National Science Library

    Offerman, Kristy; Deffur, Armin; Carulei, Olivia; Wilkinson, Robert; Douglass, Nicola; Williamson, Anna-Lise

    2015-01-01

    .... An understanding of the host innate immune responses produced by different poxvirus vectors would aid in the assessment, selection and rational design of improved vaccines for human and veterinary applications...

  4. Broad-scale latitudinal variation in female reproductive success contributes to the maintenance of a geographic range boundary in bagworms (Lepidoptera: Psychidae.

    Directory of Open Access Journals (Sweden)

    Marc Rhainds

    Full Text Available BACKGROUND: Geographic range limits and the factors structuring them are of great interest to biologists, in part because of concerns about how global change may shift range boundaries. However, scientists lack strong mechanistic understanding of the factors that set geographic range limits in empirical systems, especially in animals. METHODOLOGY/PRINCIPAL FINDINGS: Across dozens of populations spread over six degrees of latitude in the American Midwest, female mating success of the evergreen bagworm Thyridopteryx ephemeraeformis (Lepidoptera: Psychidae declines from ∼100% to ∼0% near the edge of the species range. When coupled with additional latitudinal declines in fecundity and in egg and pupal survivorship, a spatial gradient of bagworm reproductive success emerges. This gradient is associated with a progressive decline in local abundance and an increased risk of local population extinction, up to a latitudinal threshold where extremely low female fitness meshes spatially with the species' geographic range boundary. CONCLUSIONS/SIGNIFICANCE: The reduction in fitness of female bagworms near the geographic range limit, which concords with the abundant centre hypothesis from biogeography, provides a concrete, empirical example of how an Allee effect (increased pre-reproductive mortality of females in sparsely populated areas may interact with other demographic factors to induce a geographic range limit.

  5. Myxoma virus M064 is a novel member of the poxvirus C7L superfamily of host range factors that controls the kinetics of myxomatosis in European rabbits.

    Science.gov (United States)

    Liu, Jia; Wennier, Sonia; Moussatche, Nissin; Reinhard, Mary; Condit, Richard; McFadden, Grant

    2012-05-01

    The myxoma virus (MYXV) carries three tandem C7L-like host range genes (M062R, M063R, and M064R). However, despite the fact that the sequences of these three genes are similar, they possess very distinctive functions in vivo. The role of M064 in MYXV pathogenesis was investigated and compared to the roles of M062 and M063. We report that M064 is a virulence factor that contributes to MYXV pathogenesis but lacks the host range properties associated with M062 and M063.

  6. Single Mutations in the VP2 300 Loop Region of the Three-Fold Spike of the Carnivore Parvovirus Capsid Can Determine Host Range

    Science.gov (United States)

    Organtini, Lindsey J.; Zhang, Sheng; Hafenstein, Susan L.; Holmes, Edward C.

    2015-01-01

    ABSTRACT Sylvatic carnivores, such as raccoons, have recently been recognized as important hosts in the evolution of canine parvovirus (CPV), a pandemic pathogen of domestic dogs. Although viruses from raccoons do not efficiently bind the dog transferrin receptor (TfR) or infect dog cells, a single mutation changing an aspartic acid to a glycine at capsid (VP2) position 300 in the prototype raccoon CPV allows dog cell infection. Because VP2 position 300 exhibits extensive amino acid variation among the carnivore parvoviruses, we further investigated its role in determining host range by analyzing its diversity and evolution in nature and by creating a comprehensive set of VP2 position 300 mutants in infectious clones. Notably, some position 300 residues rendered CPV noninfectious for dog, but not cat or fox, cells. Changes of adjacent residues (residues 299 and 301) were also observed often after cell culture passage in different hosts, and some of the mutations mimicked changes seen in viruses recovered from natural infections of alternative hosts, suggesting that compensatory mutations were selected to accommodate the new residue at position 300. Analysis of the TfRs of carnivore hosts used in the experimental evolution studies demonstrated that their glycosylation patterns varied, including a glycan present only on the domestic dog TfR that dictates susceptibility to parvoviruses. Overall, there were significant differences in the abilities of viruses with alternative position 300 residues to bind TfRs and infect different carnivore hosts, demonstrating that the process of infection is highly host dependent and that VP2 position 300 is a key determinant of host range. IMPORTANCE Although the emergence and pandemic spread of canine parvovirus (CPV) are well documented, the carnivore hosts and evolutionary pathways involved in its emergence remain enigmatic. We recently demonstrated that a region in the capsid structure of CPV, centered around VP2 position 300

  7. Intraspecific variability in host manipulation by parasites

    OpenAIRE

    Thomas, F; Brodeur, J; Maure, F.; De Franceschi, N.; Blanchet, S.; Rigaud, T.

    2011-01-01

    Manipulative parasites have the capacity to alter a broad range of phenotypic traits in their hosts, extending from colour, morphology and behaviour. While significant attention has been devoted to describing the diversity of host manipulation among parasite clades, and testing the adaptive value of phenotypic traits that can be manipulated, there is increasing evidence that variation exists in the frequency and intensity of the changes displayed by parasitized individuals within single host-...

  8. Use of a novel cell-based fusion reporter assay to explore the host range of human respiratory syncytial virus F protein

    Directory of Open Access Journals (Sweden)

    Sarisky Robert T

    2005-07-01

    Full Text Available Abstract Human respiratory syncytial virus (HRSV is an important respiratory pathogen primarily affecting infants, young children, transplant recipients and the elderly. The F protein is the only virion envelope protein necessary and sufficient for virus replication and fusion of the viral envelope membrane with the target host cell. During natural infection, HRSV replication is limited to respiratory epithelial cells with disseminated infection rarely, if ever, occurring even in immunocompromised patients. However, in vitro infection of multiple human and non-human cell types other than those of pulmonary tract origin has been reported. To better define host cell surface molecules that mediate viral entry and dissect the factors controlling permissivity for HRSV, we explored the host range of HRSV F protein mediated fusion. Using a novel recombinant reporter gene based fusion assay, HRSV F protein was shown to mediate fusion with cells derived from a wide range of vertebrate species including human, feline, equine, canine, bat, rodent, avian, porcine and even amphibian (Xenopus. That finding was extended using a recombinant HRSV engineered to express green fluorescent protein (GFP, to confirm that viral mRNA expression is limited in several cell types. These findings suggest that HRSV F protein interacts with either highly conserved host cell surface molecules or can use multiple mechanisms to enter cells, and that the primary determinants of HRSV host range are at steps post-entry.

  9. Inhibition of human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1) infectivity with a broad range of lectins

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Vestergaard, B F

    1991-01-01

    Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV infe......-1 infection, the most potent inhibition was found with the lectin HPA. These results indicate that lectins may have a broad antiviral effect on enveloped viruses only limited by types of oligosaccharides present on individual viruses.......Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV...... infection in nanomolar-micromolar concentrations, but no anti-HIV effect was found with the lectin HPA, mainly reacting with O-linked oligosaccharides. HSV-1 infectivity was measured in a plaque reduction assay using Vero cells, and while both N- and O-linked oligosaccharide -specific lectins inhibited HSV...

  10. A C-type lectin isolated from the skin of Japanese bullhead shark (Heterodontus japonicus) binds a remarkably broad range of sugars and induces blood coagulation.

    Science.gov (United States)

    Tsutsui, Shigeyuki; Dotsuta, Yuma; Ono, Ayaka; Suzuki, Masanari; Tateno, Hiroaki; Hirabayashi, Jun; Nakamura, Osamu

    2015-05-01

    The aim of this study was to determine the physiological role of skin lectins of the Japanese bullhead shark (Heterodontus japonicus). A skin extract was subjected to affinity chromatography using seven different sugars as ligands. Molecular mass and N-terminal amino acid sequence analyses indicated elution of the same protein by each of the seven respective cognate ligands from sugar affinity columns. The predicted amino acid sequence encoded by the cDNA of this protein [designated as H. japonicus C-type-lectin (HjCL)] identified it as a novel fish subgroup VII C-type lectin evolutionarily related to snake venom lectins. HjCL was predicted to bind to mannose because of the presence of a Glu-Pro-Asn (EPN) motif; however, haemagglutination inhibition assays and glycoconjugate microarray analysis demonstrated its binding to numerous structurally diverse sugars. Competitive sugar-binding assays using affinity chromatography indicated that HjCL bound multiple sugars via a common carbohydrate-recognition domain. The mRNA encoding HjCL was specifically detected in the skin, and immunohistochemical analysis detected its expression in uncharacterized large cells in the epidermis. HjCL agglutinated the bacterial pathogen Edwardsiella tarda and promoted immediate clotting of shark blood, indicating that HjCL is involved in host defence on the skin surface especially when the shark is injured and bleeds. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  11. White LEDs as broad spectrum light sources for spectrophotometry: demonstration in the visible spectrum range in a diode-array spectrophotometric detector.

    Science.gov (United States)

    Piasecki, Tomasz; Breadmore, Michael C; Macka, Mirek

    2010-11-01

    Although traditional lamps, such as deuterium lamps, are suitable for bench-top instrumentation, their compatibility with the requirements of modern miniaturized instrumentation is limited. This study investigates the option of utilizing solid-state light source technology, namely white LEDs, as a broad band spectrum source for spectrophotometry. Several white light LEDs of both RGB and white phosphorus have been characterized in terms of their emission spectra and energy output and a white phosphorus Luxeon LED was then chosen for demonstration as a light source for visible-spectrum spectrophotometry conducted in CE. The Luxeon LED was fixed onto the base of a dismounted deuterium (D(2) ) lamp so that the light-emitting spot was geometrically positioned exactly where the light-emitting spot of the original D(2) lamp is placed. In this manner, the detector of a commercial CE instrument equipped with a DAD was not modified in any way. As the detector hardware and electronics remained the same, the change of the deuterium lamp for the Luxeon white LED allowed a direct comparison of their performances. Several anionic dyes as model analytes with absorption maxima between 450 and 600 nm were separated by CE in an electrolyte of 0.01 mol/L sodium tetraborate. The absorbance baseline noise as the key parameter was 5 × lower for the white LED lamp, showing clearly superior performance to the deuterium lamp in the available, i.e. visible part of the spectrum. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Transient dominant host-range selection using Chinese hamster ovary cells to generate marker-free recombinant viral vectors from vaccinia virus.

    Science.gov (United States)

    Liu, Liang; Cooper, Tamara; Eldi, Preethi; Garcia-Valtanen, Pablo; Diener, Kerrilyn R; Howley, Paul M; Hayball, John D

    2017-04-01

    Recombinant vaccinia viruses (rVACVs) are promising antigen-delivery systems for vaccine development that are also useful as research tools. Two common methods for selection during construction of rVACV clones are (i) co-insertion of drug resistance or reporter protein genes, which requires the use of additional selection drugs or detection methods, and (ii) dominant host-range selection. The latter uses VACV variants rendered replication-incompetent in host cell lines by the deletion of host-range genes. Replicative ability is restored by co-insertion of the host-range genes, providing for dominant selection of the recombinant viruses. Here, we describe a new method for the construction of rVACVs using the cowpox CP77 protein and unmodified VACV as the starting material. Our selection system will expand the range of tools available for positive selection of rVACV during vector construction, and it is substantially more high-fidelity than approaches based on selection for drug resistance.

  13. Insertion of vaccinia virus C7L host range gene into NYVAC-B genome potentiates immune responses against HIV-1 antigens

    National Research Council Canada - National Science Library

    Nájera, José Luis; Gómez, Carmen Elena; García-Arriaza, Juan; Sorzano, Carlos Oscar; Esteban, Mariano

    2010-01-01

    ... while maintaining an attenuated phenotype in mice. In an effort to improve the immunogenicity of NYVAC, we have developed a novel poxvirus vector by inserting the VACV host-range C7L gene into the genome of NYVAC-B, a recombinant virus that expresses...

  14. ‘Candidatus Megaira polyxenophila’ gen. nov., sp. nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent Rickettsiae

    Science.gov (United States)

    Vannini, Claudia; Galati, Stefano; Schweikert, Michael; Görtz, Hans-Dieter; Verni, Franco; Petroni, Giulio

    2013-01-01

    “Neglected Rickettsiaceae” (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria. PMID:23977321

  15. The roles of ecological fitting, phylogeny and physiological equivalence in understanding realized and fundamental host ranges in endoparasitoid wasps

    NARCIS (Netherlands)

    Harvey, J.A.; Ximenez De Embun, M.G.; Bukovinszky, T.; Gols, R.

    2012-01-01

    Co-evolutionary theory underpins our understanding of interactions in nature involving plant-herbivore and host-parasite interactions. However, many studies that are published in the empirical literature that have explored life history and development strategies between endoparasitoid wasps and

  16. Improving the Catalytic Activity of Hyperthermophilic Pyrococcus horikoshii Prolidase for Detoxification of Organophosphorus Nerve Agents over a Broad Range of Temperatures

    Directory of Open Access Journals (Sweden)

    Casey M. Theriot

    2011-01-01

    Full Text Available Prolidases hydrolyze Xaa-Pro dipeptides and can also cleave the P-F and P-O bonds found in organophosphorus (OP compounds, including the nerve agents soman and sarin. Ph1prol (PH0974 has previously been isolated and characterized from Pyrococcus horikoshii and was shown to have higher catalytic activity over a broader pH range, higher affinity for metal, and increased thermostability compared to P. furiosus prolidase, Pfprol (PF1343. To obtain a better enzyme for OP nerve agent decontamination and to investigate the structural factors that may influence protein thermostability and thermoactivity, randomly mutated Ph1prol enzymes were prepared. Four Ph1prol mutants (A195T/G306S-, Y301C/K342N-, E127G/E252D-, and E36V-Ph1prol were isolated which had greater thermostability and improved activity over a broader range of temperatures against Xaa-Pro dipeptides and OP nerve agents compared to wild type Pyrococcus prolidases.

  17. Responses Of Alpine Vegetation To Global Warming: Insights From Comparing Alpine-Restricted And Broad-Ranging Herbs Along Snowmelt Gradients

    Science.gov (United States)

    Butz, R. J.; Reinhardt, K. S.; Germino, M. J.; Kueppers, L. M.

    2009-12-01

    Many alpine plant species face habitat fragmentation and loss, and even extinction because their narrow elevation, precipitation, and temperature tolerances limit their geographic distribution. In order to assess the impacts of climate change on sensitive native alpine communities we used a variety of methods to look at the seasonal timing of life stages (phenology) and the stress responses (physiology) of alpine species along a natural environmental gradient at Niwot Ridge in the Colorado Rocky Mountains to address the following question: Will alpine plants be impaired in their existing range as a result of climate change? We collected data on date of snowmelt and vegetative and flowering phenology of all alpine species present from snowmelt to senescence in 80 1m2 plots above treeline. In addition, we measured soil temperature and moisture, plant water potential and leaf-level gas exchange early, mid, and late-season on three alpine-restricted and three broader-ranging alpine species: Geum rossii, Artemisia scopulorum, Carex rupestris, Lewisia pygmaea, Tetraneuris grandiflora, and Sibbaldia procumbens. In 2009, the natural variation in snowmelt timing was 40 days (approximately 5.5 weeks) over the 80 plots. Our results suggest that with earlier snowmelt, the number of vascular species per plot increases. However, this increase is almost exclusively attributable to wider ranging species not restricted to the alpine. Plots with intermediate natural snowmelt dates had a higher diversity of alpine-restricted species, photosynthesis, and water-use efficiency, thereby potentially increasing long-term survival rates amongst alpine species. Water stress increased in all species as the season progressed, especially in plots where snow melted earliest. Photosynthetic productivity and diversity of alpine-restricted species was greatest in plots having intermediate melt dates. These findings suggest that shifts in snowmelt date under a warming climate will likely impact the

  18. Rumen microbial community composition varies with diet and host, but a core microbiome is found across a wide geographical range

    Science.gov (United States)

    Henderson, Gemma; Cox, Faith; Ganesh, Siva; Jonker, Arjan; Young, Wayne; Abecia, Leticia; Angarita, Erika; Aravena, Paula; Nora Arenas, Graciela; Ariza, Claudia; Attwood, Graeme T.; Mauricio Avila, Jose; Avila-Stagno, Jorge; Bannink, André; Barahona, Rolando; Batistotti, Mariano; Bertelsen, Mads F.; Brown-Kav, Aya; Carvajal, Andres M.; Cersosimo, Laura; Vieira Chaves, Alexandre; Church, John; Clipson, Nicholas; Cobos-Peralta, Mario A.; Cookson, Adrian L.; Cravero, Silvio; Cristobal Carballo, Omar; Crosley, Katie; Cruz, Gustavo; Cerón Cucchi, María; de la Barra, Rodrigo; De Menezes, Alexandre B.; Detmann, Edenio; Dieho, Kasper; Dijkstra, Jan; dos Reis, William L. S.; Dugan, Mike E. R.; Hadi Ebrahimi, Seyed; Eythórsdóttir, Emma; Nde Fon, Fabian; Fraga, Martín; Franco, Francisco; Friedeman, Chris; Fukuma, Naoki; Gagić, Dragana; Gangnat, Isabelle; Javier Grilli, Diego; Guan, Le Luo; Heidarian Miri, Vahideh; Hernandez-Sanabria, Emma; Gomez, Alma Ximena Ibarra; Isah, Olubukola A.; Ishaq, Suzanne; Jami, Elie; Jelincic, Juan; Kantanen, Juha; Kelly, William J.; Kim, Seon-Ho; Klieve, Athol; Kobayashi, Yasuo; Koike, Satoshi; Kopecny, Jan; Nygaard Kristensen, Torsten; Julie Krizsan, Sophie; LaChance, Hannah; Lachman, Medora; Lamberson, William R.; Lambie, Suzanne; Lassen, Jan; Leahy, Sinead C.; Lee, Sang-Suk; Leiber, Florian; Lewis, Eva; Lin, Bo; Lira, Raúl; Lund, Peter; Macipe, Edgar; Mamuad, Lovelia L.; Cuquetto Mantovani, Hilário; Marcoppido, Gisela Ariana; Márquez, Cristian; Martin, Cécile; Martinez, Gonzalo; Eugenia Martinez, Maria; Lucía Mayorga, Olga; McAllister, Tim A.; McSweeney, Chris; Mestre, Lorena; Minnee, Elena; Mitsumori, Makoto; Mizrahi, Itzhak; Molina, Isabel; Muenger, Andreas; Munoz, Camila; Murovec, Bostjan; Newbold, John; Nsereko, Victor; O’Donovan, Michael; Okunade, Sunday; O’Neill, Brendan; Ospina, Sonia; Ouwerkerk, Diane; Parra, Diana; Pereira, Luiz Gustavo Ribeiro; Pinares-Patino, Cesar; Pope, Phil B.; Poulsen, Morten; Rodehutscord, Markus; Rodriguez, Tatiana; Saito, Kunihiko; Sales, Francisco; Sauer, Catherine; Shingfield, Kevin; Shoji, Noriaki; Simunek, Jiri; Stojanović-Radić, Zorica; Stres, Blaz; Sun, Xuezhao; Swartz, Jeffery; Liang Tan, Zhi; Tapio, Ilma; Taxis, Tasia M.; Tomkins, Nigel; Ungerfeld, Emilio; Valizadeh, Reza; van Adrichem, Peter; Van Hamme, Jonathan; Van Hoven, Woulter; Waghorn, Garry; John Wallace, R.; Wang, Min; Waters, Sinéad M.; Keogh, Kate; Witzig, Maren; Wright, Andre-Denis G.; Yamano, Hidehisa; Yan, Tianhai; Yanez-Ruiz, David R.; Yeoman, Carl J.; Zambrano, Ricardo; Zeitz, Johanna; Zhou, Mi; Wei Zhou, Hua; Xia Zou, Cai; Zunino, Pablo; Janssen, Peter H.

    2015-01-01

    Ruminant livestock are important sources of human food and global greenhouse gas emissions. Feed degradation and methane formation by ruminants rely on metabolic interactions between rumen microbes and affect ruminant productivity. Rumen and camelid foregut microbial community composition was determined in 742 samples from 32 animal species and 35 countries, to estimate if this was influenced by diet, host species, or geography. Similar bacteria and archaea dominated in nearly all samples, while protozoal communities were more variable. The dominant bacteria are poorly characterised, but the methanogenic archaea are better known and highly conserved across the world. This universality and limited diversity could make it possible to mitigate methane emissions by developing strategies that target the few dominant methanogens. Differences in microbial community compositions were predominantly attributable to diet, with the host being less influential. There were few strong co-occurrence patterns between microbes, suggesting that major metabolic interactions are non-selective rather than specific. PMID:26449758

  19. Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

    Directory of Open Access Journals (Sweden)

    Markus Preißinger

    2017-02-01

    Full Text Available Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC can contribute to the reduction of CO2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 °C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

  20. Using a Pareto-optimal solution set to characterize trade-offs between a broad range of values and preferences in climate risk management

    Science.gov (United States)

    Garner, Gregory; Reed, Patrick; Keller, Klaus

    2015-04-01

    Integrated assessment models (IAMs) are often used to inform the design of climate risk management strategies. Previous IAM studies have broken important new ground on analyzing the effects of parametric uncertainties, but they are often silent on the implications of uncertainties regarding the problem formulation. Here we use the Dynamic Integrated model of Climate and the Economy (DICE) to analyze the effects of uncertainty surrounding the definition of the objective(s). The standard DICE model adopts a single objective to maximize a weighted sum of utilities of per-capita consumption. Decision makers, however, are often concerned with a broader range of values and preferences that may be poorly captured by this a priori definition of utility. We reformulate the problem by introducing three additional objectives that represent values such as (i) reliably limiting global average warming to two degrees Celsius and minimizing (ii) the costs of abatement and (iii) the climate change damages. We use advanced multi-objective optimization methods to derive a set of Pareto-optimal solutions over which decision makers can trade-off and assess performance criteria a posteriori. We illustrate the potential for myopia in the traditional problem formulation and discuss the capability of this multiobjective formulation to provide decision support.

  1. An rRT-PCR assay to detect the matrix gene of a broad range of avian paramyxovirus serotype-1 strains.

    Science.gov (United States)

    Hines, Nichole L; Killian, Mary Lea; Pedersen, Janice C; Reising, Monica M; Mosos, Nestor A; Mathieu-Benson, Christian; Miller, Cathy L

    2012-06-01

    The current U.S. Department of Agriculture (USDA)-validated real-time reverse transcription-polymerase chain reaction (rRT-PCR) assay designed to detect the matrix gene of avian paramyxovirus serotype-1 (APMV-1) is the primary screening assay used in the United States. It has previously been shown to be unable to consistently detect all members of class I APMV-1. Diagnostic testing relies on rRT-PCR to quickly detect APMV-1 in wild birds, backyard flocks, live bird markets, commercial poultry, and for export testing. Limitations of the current USDA assay have raised concerns about the potential for some strains of APMV-1 to remain undetected by the primary screening assay. Mismatches in the probe were shown to cause a loss in template binding efficiency, resulting in lack of detection by the assay. Here, we describe the development and analytical validation of a new rRT-PCR assay designed to target a highly conserved region of the matrix gene across a wide range of APMV-1 strains. Limit of detection testing revealed a 3 log10 decrease in sensitivity for one low-virulence strain when compared to the USDA validated assay. Conversely, the assay showed increased sensitivity for a class I isolate and two virulent strains of APMV-1 that were not detected by the USDA-validated assay. The new assay also demonstrated a high degree of specificity by the lack of detection of 43 non-APMV-1 viruses.

  2. Short-term changes in bone formation markers following growth hormone (GH) treatment in short prepubertal children with a broad range of GH secretion.

    Science.gov (United States)

    Andersson, Björn; Swolin-Eide, Diana; Magnusson, Per; Albertsson-Wikland, Kerstin

    2015-01-01

    Growth hormone (GH) promotes longitudinal growth and bone modelling/remodelling. This study investigated the relationship between levels of bone formation markers and growth during GH treatment in prepubertal children with widely ranging GH secretion levels. The study group comprised 113 short prepubertal children (mean age ± SD, 9·37 ± 2·13 years; 99 boys) on GH treatment (33·0 ± 0·06 μg/kg/day) for 1 year. Blood samples were taken at baseline and 1 and 2 weeks, 1 and 3 months, and 1 year after treatment start. Intact amino-terminal propeptide of type I procollagen (PINP), bone-specific alkaline phosphatase (BALP) and osteocalcin were measured using an automated IDS-iSYS immunoassay system. Intact amino-terminal propeptide of type I procollagen (PINP), BALP and osteocalcin, increased in the short-term during GH treatment. PINP after 1 week (P = 0·00077), and BALP and osteocalcin after 1 month (P growth response. No significant correlations were found between BALP and first year growth. Multiple regression analysis showed that bone marker levels together with auxological data and insulin-like growth factor binding protein-3 explained the variation in first year growth response to 36% at start, 32% after 2 weeks and 48% at 3 months. Short-term increases in levels of the bone formation markers PINP, BALP and osteocalcin showed different temporal patterns, but all correlated with first year growth response during GH treatment. These markers may be a useful addition to existing prediction models for growth response. © 2014 John Wiley & Sons Ltd.

  3. Global effects of the DEAD-box RNA helicase DeaD (CsdA) on gene expression over a broad range of temperatures

    Science.gov (United States)

    Vakulskas, Christopher A.; Pannuri, Archana; Cortés-Selva, Diana; Zere, Tesfalem R.; Ahmer, Brian M.; Babitzke, Paul; Romeo, Tony

    2014-01-01

    Summary In Escherichia coli, activity of the global regulatory RNA binding protein CsrA is antagonized by two noncoding sRNAs, CsrB and CsrC, which sequester it away from its lower affinity mRNA targets. Transcription of csrB/C requires the BarA-UvrY two component signal transduction system, which responds to short chain carboxylates. We show that two DEAD-box RNA helicases, DeaD and SrmB, activate csrB/C expression by different pathways. DeaD facilitates uvrY translation by counteracting the inhibitory effect of long distance basepairing between the uvrY mRNA leader and coding region, while SrmB does not affect UvrY or UvrY-phosphate levels. Contrary to the prevailing notion that these helicases act primarily at low temperatures, DeaD and SrmB activated csrB expression over a wide temperature range. High-throughput sequencing of RNA isolated by crosslinking immunoprecipitation (HITS-CLIP) revealed in vivo interactions of DeaD with 39 mRNAs, including those of uvrY and 9 other regulatory genes. Studies on the expression of several of the identified genes revealed regulatory effects of DeaD in all cases and diverse temperature response patterns. Our findings uncover an expanded regulatory role for DeaD, which is mediated through novel mRNA targets, important global regulators and under physiological conditions that were considered to be incompatible with its function. PMID:24708042

  4. Segmentation of brain magnetic resonance images based on multi-atlas likelihood fusion: testing using data with a broad range of anatomical and photometric profiles.

    Science.gov (United States)

    Tang, Xiaoying; Crocetti, Deana; Kutten, Kwame; Ceritoglu, Can; Albert, Marilyn S; Mori, Susumu; Mostofsky, Stewart H; Miller, Michael I

    2015-01-01

    We propose a hierarchical pipeline for skull-stripping and segmentation of anatomical structures of interest from T1-weighted images of the human brain. The pipeline is constructed based on a two-level Bayesian parameter estimation algorithm called multi-atlas likelihood fusion (MALF). In MALF, estimation of the parameter of interest is performed via maximum a posteriori estimation using the expectation-maximization (EM) algorithm. The likelihoods of multiple atlases are fused in the E-step while the optimal estimator, a single maximizer of the fused likelihoods, is then obtained in the M-step. There are two stages in the proposed pipeline; first the input T1-weighted image is automatically skull-stripped via a fast MALF, then internal brain structures of interest are automatically extracted using a regular MALF. We assess the performance of each of the two modules in the pipeline based on two sets of images with markedly different anatomical and photometric contrasts; 3T MPRAGE scans of pediatric subjects with developmental disorders vs. 1.5T SPGR scans of elderly subjects with dementia. Evaluation is performed quantitatively using the Dice overlap as well as qualitatively via visual inspections. As a result, we demonstrate subject-level differences in the performance of the proposed pipeline, which may be accounted for by age, diagnosis, or the imaging parameters (particularly the field strength). For the subcortical and ventricular structures of the two datasets, the hierarchical pipeline is capable of producing automated segmentations with Dice overlaps ranging from 0.8 to 0.964 when compared with the gold standard. Comparisons with other representative segmentation algorithms are presented, relative to which the proposed hierarchical pipeline demonstrates comparative or superior accuracy.

  5. Segmentation of brain magnetic resonance images based on multi-atlas likelihood fusion: testing using data with a broad range of anatomical and photometric profiles

    Directory of Open Access Journals (Sweden)

    Xiaoying eTang

    2015-03-01

    Full Text Available We propose a hierarchical pipeline for skull-stripping and segmentation of anatomical structures of interest from T1-weighted images of the human brain. The pipeline is constructed based on a two-level Bayesian parameter estimation algorithm called multi-atlas likelihood fusion (MALF. In MALF, estimation of the parameter of interest is performed via maximum a posteriori estimation using the expectation-maximization (EM algorithm. The likelihoods of multiple atlases are fused in the E-step while the optimal estimator, a single maximizer of the fused likelihoods, is then obtained in the M-step. There are two stages in the proposed pipeline; first the input T1-weighted image is automatically skull-stripped via a fast MALF, then internal brain structures of interest are automatically extracted using a regular MALF. We assess the performance of each of the two modules in the pipeline based on two sets of images with markedly different anatomical and photometric contrasts; 3T MPRAGE scans of pediatric subjects with developmental disorders versus 1.5T SPGR scans of elderly subjects with dementia. Evaluation is performed quantitatively using the Dice overlap as well as qualitatively via visual inspections. As a result, we demonstrate subject-level differences in the performance of the proposed pipeline, which may be accounted for by age, diagnosis, or the imaging parameters (particularly the field strength. For the subcortical and ventricular structures of the two datasets, the hierarchical pipeline is capable of producing automated segmentations with Dice overlaps ranging from 0.8 to 0.964 when compared with the gold standard. Comparisons with other representative segmentation algorithms are presented, relative to which the proposed hierarchical pipeline demonstrates comparative or superior accuracy.

  6. Examination of Enterococcus faecalis Toxin-Antitoxin System Toxin Fst Function Utilizing a Pheromone-Inducible Expression Vector with Tight Repression and Broad Dynamic Range.

    Science.gov (United States)

    Weaver, Keith E; Chen, Yuqing; Miiller, Elly M; Johnson, Jake N; Dangler, Alex A; Manias, Dawn A; Clem, Aaron M; Schjodt, Daniel J; Dunny, Gary M

    2017-06-15

    Tools for regulated gene expression in Enterococcus faecalis are extremely limited. In this report, we describe the construction of an expression vector for E. faecalis, designated pCIE, utilizing the PQ pheromone-responsive promoter of plasmid pCF10. We demonstrate that this promoter is tightly repressed, responds to nanogram quantities of the peptide pheromone, and has a large dynamic range. To demonstrate its utility, the promoter was used to control expression of the toxic peptides of two par family toxin-antitoxin (TA) loci present in E. faecalis, parpAD1 of the pAD1 plasmid and parEF0409 located on the E. faecalis chromosome. The results demonstrated differences in the modes of regulation of toxin expression and in the effects of toxins of these two related systems. We anticipate that this vector will be useful for further investigation of par TA system function as well as the regulated expression of other genes in E. faecalisIMPORTANCEE. faecalis is an important nosocomial pathogen and a model organism for examination of the genetics and physiology of Gram-positive cocci. While numerous genetic tools have been generated for the manipulation of this organism, vectors for the regulated expression of cloned genes remain limited by high background expression and the use of inducers with undesirable effects on the cell. Here we demonstrate that the PQ pheromone-responsive promoter is repressed tightly enough to allow cloning of TA system toxins and evaluate their effects at very low induction levels. This tool will allow us to more fully examine TA system function in E. faecalis and to further elucidate its potential roles in cell physiology. Copyright © 2017 American Society for Microbiology.

  7. Evaluation of host range and larval feeding impact of Chrysolina aurichalcea asclepiadis (Villa): considerations for biological control of Vincetoxicum in North America.

    Science.gov (United States)

    Weed, Aaron S; Casagrande, Richard A

    2011-12-01

    A biological control program has been initiated against European swallow-worts Vincetoxicum nigrum (L.) Moench. and V. rossicum (Kleopow) Barbar., which are invasive in North America. A population of the leaf beetle Chrysolina aurichalcea asclepiadis (Villa) originating from the western Alps has been under evaluation as a part of this program. The preliminary host range of C. a. asclepiadis was determined among 37 potential host plants. In addition, a prerelease impact study was conducted to determine the effect of larval feeding on the performance of V. nigrum. Under no-choice conditions beetle larvae completed development on nine plant species within the genera Artemisia and Tanacetum (Asteraceae) and Asclepias and Vincetoxicum (Apocynaceae). The host range of adults is broader than larvae (13 plant species within five genera received sustained feeding). Three of the six nontarget species supporting larval development are native to North America, however in separate oviposition tests, female beetles failed to produce eggs when confined to these hosts. In multiple-choice tests, neither larvae nor adults preferred Vincetoxicum spp. to nontarget species. Larval damage by C. a. asclepiadis at densities at and above five larvae per plant substantially reduced growth, biomass, and delayed reproduction of V. nigrum. However, this population of C. a. asclepiadis is polyphagous and unsuitable for biological control of Vincetoxicum because of potential risk of attack to Asclepias tuberosa L. and native North American Asteraceae, particularly Artemisia.

  8. Egg-laying by the butterfly Iphiclides podalirius (Lepidoptera, Papilionidae on alien plants: a broadening of host range or oviposition mistakes?

    Directory of Open Access Journals (Sweden)

    Stefanescu, C.

    2006-06-01

    Full Text Available Iphiclides podalirius is an oligophagous butterfly which feeds on plants of the Rosaceae family. In 2002 and 2005 in NE Spain, we recorded for the first time oviposition on two alien plant species, Cotoneaster franchetii and Spiraea cantoniensis. To ascertain if this unusual behaviour represents a broadening of host range or, alternatively, an oviposition mistake, larval performance on the new plants was investigated in the laboratory and compared with performance on the most common host plants used in the study area. Although larval performance on common hosts differed to some extent, the use of a wide range of plants of different quality at population level may in fact respond to the so-called “spreading of risk” strategy in variable environments. On the other hand, larval performance and survival to adulthood were so low on the two new hosts that our observations probably represent a case of maladaptive oviposition behaviour. This may be due to an evolutionary lag between the newly introduced plants and the insect, although other possible explanations are also taken into account.

  9. Host range of an NPV and a GV isolated from the common cutworm, Agrotis segetum: pathogenicity within the cutworm complex

    NARCIS (Netherlands)

    Bourner, T.C.; Cory, J.S.

    2004-01-01

    The term cutworm covers a range of species with a similar life history that can be very damaging pests on a wide range of crops. Attacks by cutworms are often made up of more than one species; thus, the most cost effective microbial control agent needs to be pathogenic for multiple species within

  10. M-T5, the ankyrin repeat, host range protein of myxoma virus, activates Akt and can be functionally replaced by cellular PIKE-A.

    Science.gov (United States)

    Werden, Steven J; Barrett, John W; Wang, Gen; Stanford, Marianne M; McFadden, Grant

    2007-03-01

    The myxoma virus (MV) ankyrin repeat, host range factor M-T5 has the ability to bind and activate cellular Akt, leading to permissive MV replication in a variety of diverse human cancer cell lines (G. Wang, J. W. Barrett, M. Stanford, S. J. Werden, J. B. Johnston, X. Gao, M. Sun, J. Q. Cheng, and G. McFadden, Proc. Natl. Acad. Sci. USA 103:4640-4645, 2006). The susceptibility of permissive human cancer cells to MV infection is directly correlated with the basal or induced levels of phosphorylated Akt. When M-T5 is deleted from MV, the knockout virus, vMyxT5KO, can no longer productively infect a subset of human cancer cells (designated type II) that exhibit little or no endogenous phosphorylated Akt. In searching for a host counterpart of M-T5, we noted sequence similarity of M-T5 to a recently identified ankyrin repeat cellular binding protein of Akt called PIKE-A. PIKE-A binds and activates the kinase activity of Akt in a GTP-dependent manner and promotes the invasiveness of human cancer cell lines. Here, we demonstrate that transfected PIKE-A is able to rescue the ability of vMyxT5KO to productively infect type II human cancer cells that were previously resistant to infection. Also, cancer cells that were completely nonpermissive for both wild-type and vMyxT5KO infection (called type III) were rendered fully permissive following ectopic expression of PIKE-A. We conclude that the MV M-T5 host range protein is functionally interchangeable with the host PIKE-A protein and that the activation of host Akt by either M-T5 or PIKE-A is critical for the permissiveness of human cancer cells for MV.

  11. Broad temperature range antiferroelectric regular mixtures

    Science.gov (United States)

    Dabrowski, Roman; Czuprynski, Krzysztof; Gasowska, J.; Oton, Jose; Quintana, Xabier; Castillo, P. L.; Bennis, N.

    2004-09-01

    Tristate regular mixtures with different electro-optical properties such as threshold voltage, saturation voltage, holding ratio and response time are presented. The relation of properties with the structure of compounds is discussed. All of mixtures show only moderate dynamic and static contrast but big gray level scale without hysteresis for positive and negative field driving.

  12. African Journals Online: Humanities (broad subject range)

    African Journals Online (AJOL)

    Items 1 - 50 of 55 ... It focuses both on conceptual or theoretical approaches and case studies or essays demonstrating how advanced information technologies further scholarly .... Global Journal of Humanities is aimed at promoting reasearch in all areas of Humanities including philosophy, languages, linguistics, literature, ...

  13. African Journals Online: Humanities (broad subject range)

    African Journals Online (AJOL)

    ... of Uganda and to record for posterity that which in the course of time might be lost, the journal also has widened its purpose to become the society's forum for broader intellectual exchanges and debate about Uganda. The emphasis is to maintain a strong organic linkage with the larger Ugandan public in all its diversity.

  14. Host range and diversity of the genus Geosmithia (Ascomycota: Hypocreales) living in association with bark beetles in the Mediterranean area.

    Science.gov (United States)

    Kolarík, Miroslav; Kostovcík, Martin; Pazoutová, Sylvie

    2007-11-01

    Geosmithia spp. (Ascomycota: Hypocreales) are dry-spored fungi that occur in galleries built by many phloeophagous bark beetles. This study mapped the diversity, host spectrum and area of distribution of Geosmithia spp. occurring in galleries of bark beetle species with a Mediterranean distribution. Eighty-six wood samples of 19 tree species infested by 18 subcortical insect species were collected from across the Mediterranean Basin during the years 2003-2006. Geosmithia spp. were found in 82 samples of angiosperms and two host trees from the family Juniperaceae infested by 14 bark beetles and the bostrichid Scobicia pustulata, suggesting that the association of Geosmithia and phloeophagous bark beetles is very widespread in the Mediterranean. Geosmithia isolates were sorted into 13 operational taxonomic units (OTUs) based on their phenotype similarity and phylogeny of their ITS regions of rDNA (ITS1-5.8S-ITS2). The OTUs represent five known species (G. flava, G. langdonii, G. lavendula, G. pallida, G. putterillii) and seven undescribed taxa. Most of the bark beetles were associated with on average 1-2.5 OTUs per sample. G. lavendula, considered very uncommon in nature, was found as a common associate of bark beetles. Six out of 13 OTUs were found to be distributed in the Mediterranean but not in neighbouring areas of temperate Europe suggesting that Geosmithia spp. have a geographically limited distribution, probably due to their dependency on the geographically limited area of their vectors. The proportion of generalists and specialists among Geosmithia spp. was smaller compared with data from temperate Europe. A possible explanation is the effective dispersal of Geosmithia by polyphagous bostrichids across the niches defined by mutually exclusive bark beetles.

  15. Broad-range detection of arboviruses belonging to Simbu serogroup lineage 1 and specific detection of Akabane, Aino and Peaton viruses by newly developed multiple TaqMan assays.

    Science.gov (United States)

    Shirafuji, Hiroaki; Yazaki, Ryu; Shuto, Yozo; Yanase, Tohru; Kato, Tomoko; Ishikura, Youji; Sakaguchi, Zenjiro; Suzuki, Moemi; Yamakawa, Makoto

    2015-12-01

    TaqMan assays were developed for the broad-range detection of arboviruses belonging to Simbu serogroup lineage 1 in the genus Orthobunyavirus and also for the specific detection of three viruses in the lineage, Akabane, Aino and Peaton viruses (AKAV, AINOV and PEAV, respectively). A primer and probe set was designed for the broad-range detection of Simbu serogroup lineage 1 (Pan-Simbu1 set) mainly targeting AKAV, AINOV, PEAV, Sathuperi and Shamonda viruses (SATV and SHAV), and the forward and reverse primers of the Pan-Simbu1 set were also used for the specific detection of AKAV with another probe (AKAV-specific set). In addition, two more primer and probe sets were designed for AINOV- and PEAV-specific detection, respectively (AINOV- and PEAV-specific sets). All of the four primer and probe sets successfully detected targeted viruses, and thus broad-range and specific detection of all the targeted viruses can be achieved by using two multiplex assays and a single assay in a dual (two-color) assay format when another primer and probe set for a bovine β-actin control is also used. The assays had an analytical sensitivity of 10 copies/tube for AKAV, at least 100 copies/tube for AINOV, 100 copies/tube for PEAV, one copy/tube for SATV and at least 10 copies/tube for SHAV, respectively. Diagnostic sensitivity of the assays was tested with field-collected bovine samples, and the results suggested that the sensitivity was higher than that of a conventional RT-PCR. These data indicate that the newly developed TaqMan assays will be useful tools for the diagnosis and screening of field-collected samples for infections of AKAV and several other arboviruses belonging to the Simbu serogroup lineage 1. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Centrality evolution of the charged–particle pseudorapidity density over a broad pseudorapidity range in Pb–Pb collisions at $\\sqrt{s_{\\rm NN}}=2.76$ TeV

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahn, Sang Un; Aiola, Salvatore; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Millan Almaraz, Jesus Roberto; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Arnaldi, Roberta; Arnold, Oliver Werner; Arsene, Ionut Cristian; Arslandok, Mesut; Audurier, Benjamin; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Barth, Klaus; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Rathijit; Biswas, Saikat; Bjelogrlic, Sandro; Blair, Justin Thomas; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botta, Elena; Boettger, Stefan; Bourjau, Christian; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Bashir Butt, Jamila; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Carnesecchi, Francesca; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Cerkala, Jakub; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Cho, Soyeon; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Conti, Camila; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; Deplano, Caterina; Dhankher, Preeti; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Drozhzhova, Tatiana; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Epple, Eliane; Erazmus, Barbara Ewa; Erdemir, Irem; Erhardt, Filip; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Eum, Jongsik; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Feuillard, Victor Jose Gaston; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Fleck, Martin Gabriel; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Gauger, Erin Frances; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Coral, Diego Mauricio; Gomez Ramirez, Andres; Gonzalez, Victor; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Grachov, Oleg Anatolievich; Graczykowski, Lukasz Kamil; Graham, Katie Leanne; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Gronefeld, Julius Maximilian; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Harris, John William; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hillemanns, Hartmut; Hippolyte, Boris; Hosokawa, Ritsuya; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Inaba, Motoi; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacobs, Peter Martin; Jadhav, Manoj Bhanudas; Jadlovska, Slavka; Jadlovsky, Jan; Jahnke, Cristiane; Jakubowska, Monika Joanna; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karayan, Lilit; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Do Won; Kim, Dong Jo; Kim, Daehyeok; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Klewin, Sebastian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kopcik, Michal; Kour, Mandeep; Kouzinopoulos, Charalampos; Kovalenko, Oleksandr; Kovalenko, Vladimir; Kowalski, Marek; Koyithatta Meethaleveedu, Greeshma; Kralik, Ivan; Kravcakova, Adela; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kumar, Ajay; Kumar, Jitendra; Lokesh, Kumar; Kumar, Shyam; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; 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Riggi, Francesco; Ristea, Catalin-Lucian; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Sefcik, Michal; Seger, Janet Elizabeth; Sekiguchi, Yuko; Sekihata, Daiki; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Senyukov, Serhiy; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Mona; Sharma, Monika; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Sozzi, Federica; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Suljic, Miljenko; Sultanov, Rishat; Sumbera, Michal; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Tabassam, Uzma; Takahashi, Jun; Tambave, Ganesh Jagannath; Tanaka, Naoto; Tangaro, Marco-Antonio; Tarhini, Mohamad; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trombetta, Giuseppe; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Villatoro Tello, Abraham; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Watanabe, Daisuke; Watanabe, Yosuke; Weber, Michael; Weber, Steffen Georg; Weiser, Dennis Franz; Wessels, Johannes Peter; Westerhoff, Uwe; Whitehead, Andile Mothegi; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasar, Cigdem; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yoon, Jin Hee; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zardoshti, Nima; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Chunhui, Zhang; Zhang, Zuman; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

    2016-03-10

    The centrality dependence of the charged–particle pseudorapidity density measured with ALICE in Pb–Pb collisions at $\\sqrt{s_{\\rm NN}}=2.76$ TeV over a broad pseudorapidity range is presented. This Letter extends to more peripheral collisions the previous results reported by ALICE. No strong evolution of the charged–particle pseudorapidity density distributions with centrality is observed, and when the results are normalized to the number of participating nucleons in the collisions, the centrality evolution is likewise small. This suggests that hard contributions to the charged–particle multiplicity are limited. The broad pseudorapidity range allows precise estimates of the total number of produced charged particles which we find to range from $162\\pm 22$(syst.) to $17170\\pm 770$(syst.) in 80–90% and 0–5% central collisions, respectively. The results are compared to models which describe ${\\rm d}N_{\\rm ch}/{\\rm d}\\eta$ at mid–rapidity in the most central Pb–Pb collisions and it is found that t...

  17. Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb–Pb collisions at sNN=2.76 TeV

    Directory of Open Access Journals (Sweden)

    J. Adam

    2016-03-01

    Full Text Available The centrality dependence of the charged-particle pseudorapidity density measured with ALICE in Pb–Pb collisions at sNN=2.76 TeV over a broad pseudorapidity range is presented. This Letter extends the previous results reported by ALICE to more peripheral collisions. No strong change of the overall shape of charged-particle pseudorapidity density distributions with centrality is observed, and when normalised to the number of participating nucleons in the collisions, the evolution over pseudorapidity with centrality is likewise small. The broad pseudorapidity range (−3.5<η<5 allows precise estimates of the total number of produced charged particles which we find to range from 162±22(syst. to 17170±770(syst. in 80–90% and 0–5% central collisions, respectively. The total charged-particle multiplicity is seen to approximately scale with the number of participating nucleons in the collision. This suggests that hard contributions to the charged-particle multiplicity are limited. The results are compared to models which describe dNch/dη at mid-rapidity in the most central Pb–Pb collisions and it is found that these models do not capture all features of the distributions.

  18. Comparative genomic and transcriptome analyses of pathotypes of Xanthomonas citri subsp. citri provide insights into mechanisms of bacterial virulence and host range

    Science.gov (United States)

    2013-01-01

    Background Citrus bacterial canker is a disease that has severe economic impact on citrus industries worldwide and is caused by a few species and pathotypes of Xanthomonas. X. citri subsp. citri strain 306 (XccA306) is a type A (Asiatic) strain with a wide host range, whereas its variant X. citri subsp. citri strain Aw12879 (Xcaw12879, Wellington strain) is restricted to Mexican lime. Results To characterize the mechanism for the differences in host range of XccA and Xcaw, the genome of Xcaw12879 that was completed recently was compared with XccA306 genome. Effectors xopAF and avrGf1 are present in Xcaw12879, but were absent in XccA306. AvrGf1 was shown previously for Xcaw to cause hypersensitive response in Duncan grapefruit. Mutation analysis of xopAF indicates that the gene contributes to Xcaw growth in Mexican lime but does not contribute to the limited host range of Xcaw. RNA-Seq analysis was conducted to compare the expression profiles of Xcaw12879 and XccA306 in Nutrient Broth (NB) medium and XVM2 medium, which induces hrp gene expression. Two hundred ninety two and 281 genes showed differential expression in XVM2 compared to in NB for XccA306 and Xcaw12879, respectively. Twenty-five type 3 secretion system genes were up-regulated in XVM2 for both XccA and Xcaw. Among the 4,370 common genes of Xcaw12879 compared to XccA306, 603 genes in NB and 450 genes in XVM2 conditions were differentially regulated. Xcaw12879 showed higher protease activity than XccA306 whereas Xcaw12879 showed lower pectate lyase activity in comparison to XccA306. Conclusions Comparative genomic analysis of XccA306 and Xcaw12879 identified strain specific genes. Our study indicated that AvrGf1 contributes to the host range limitation of Xcaw12879 whereas XopAF contributes to virulence. Transcriptome analyses of XccA306 and Xcaw12879 presented insights into the expression of the two closely related strains of X. citri subsp. citri. Virulence genes including genes encoding T3SS components

  19. Pathogen-Host Associations and Predicted Range Shifts of Human Monkeypox in Response to Climate Change in Central Africa

    OpenAIRE

    Henri A Thomassen; Trevon Fuller; Salvi Asefi-Najafabady; Julia A G Shiplacoff; Mulembakani, Prime M.; Seth Blumberg; Johnston, Sara C.; Kisalu, Neville K.; Timothée L Kinkela; Fair, Joseph N.; Wolfe, Nathan D.; Shongo, Robert L.; Matthew LeBreton; Hermann Meyer; Wright, Linda L

    2013-01-01

    Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first c...

  20. Towards broad range and highly efficient down-conversion of solar spectrum by Er{sup 3+}-Yb{sup 3+} co-doped nano-structured glass-ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, V.D.; Mendez-Ramos, J. [Departamento de Fisica Fundamental y Experimental, Electronica y Sistemas, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain); Tikhomirov, V.K.; Moshchalkov, V.V. [INPAC-Institute for Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven (Belgium); Yanes, A.C. [Departamento de Fisica Basica, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain)

    2010-10-15

    The efficiency of semiconductor solar cells could be greatly increased by down-conversion processes, which efficiently split incident solar photons into couples of photons with energy over the bandgap. Here, we show new down-conversion mechanisms in Er{sup 3+}-Yb{sup 3+} co-doped glass-ceramics, where the ions are hosted by fluoride nanoparticles embedded in silica glass. By this means, 350-550 nm photons, absorbed by Er{sup 3+} ions, generate pairs of photons at the range of 650-1550 nm, emitted by Er{sup 3+} and Yb{sup 3+}, with a quantum efficiency approaching the maximum of 200%. (author)

  1. Molecular cloning of the plasmid RP4 primase region in a multi-host-range tacP expression vector.

    Science.gov (United States)

    Fürste, J P; Pansegrau, W; Frank, R; Blöcker, H; Scholz, P; Bagdasarian, M; Lanka, E

    1986-01-01

    Plasmid RP4 primase was overproduced by utilizing autoregulated high-level expression vector systems in Escherichia coli and in four other Gram-negative bacterial species. Analysis of the products in E. coli revealed that in addition to the two primase polypeptides of 118 and 80 kDa the pri region of RP4 encodes two smaller proteins of 16.5 and 8.6 kDa. The transcript for the four RP4-specified products is polycistronic. The vector system used in E. coli is based on the plasmid pKK223-3 (Brosius and Holy, 1984), a ColE1-type replicon which contains a polylinker sequence flanked on one side by the controllable tac promoter and on the other side by two strong transcriptional terminators. The gene for the lac repressor (lacIQ) was inserted to render the use of the plasmid independent from repressor-overproducing strains. The gene cartridge essential for high-level expression and selection was combined with the RSF1010 replicon to generate a vector plasmid functioning in a wide variety of Gram-negative hosts. The versatility of the vector family was extended by constructing derivatives that contain the polylinker in inverted orientation relative to the tac promoter. Therefore, the orientation of the cloned fragment can be chosen by 'forced cloning' into the appropriately selected vector.

  2. Characterization of California sea lion polyomavirus 1: expansion of the known host range of the Polyomaviridae to Carnivora.

    Science.gov (United States)

    Wellehan, James F X; Rivera, Rebecca; Archer, Linda L; Benham, Celeste; Muller, Jennifer K; Colegrove, Kathleen M; Gulland, Frances M D; St Leger, Judy A; Venn-Watson, Stephanie K; Nollens, Hendrik H

    2011-07-01

    The genome of a novel polyomavirus first identified in a proliferative tongue lesion of a California sea lion (Zalophus californianus) is reported. This is only the third described polyomavirus of laurasiatherian mammals, is the first of the three associated with a lesion, and is the first known polyomavirus of a host in the order Carnivora. Predicted large T, small t, VP1, VP2, and VP3 genes were identified based on homology to proteins of known polyomaviruses, and a putative agnoprotein was identified based upon its location in the genome. Phylogenetic analysis of the predicted late region proteins found that the laurasiatherian polyomaviruses, together with Squirrel monkey polyomavirus and Murine pneumotropic virus, form a monophyletic clade. Phylogenetic analysis of the early region was more ambiguous. The noncoding control region of California sea lion polyomavirus 1 is unusual in that only two apparent large T binding sites are present; this is less than any other known polyomavirus. The VP1 of this virus has an unusually long carboxy-terminal region. A quantitative polymerase chain reaction was developed and utilized on various samples from 79 additional animals from either managed or wild stranded California sea lion populations, and California sea lion polyomavirus 1 infection was found in 24% of stranded animals. Sequence of additional samples identified four sites of variation in the t antigens, three of which resulted in predicted coding changes. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Presence of Extracellular DNA during Biofilm Formation by Xanthomonas citri subsp. citri Strains with Different Host Range.

    Science.gov (United States)

    Sena-Vélez, Marta; Redondo, Cristina; Graham, James H; Cubero, Jaime

    2016-01-01

    Xanthomonas citri subsp. citri (Xcc) A strain causes citrus bacterial canker, a serious leaf, fruit and stem spotting disease of several Citrus species. X. alfalfae subsp. citrumelonis (Xac) is the cause of citrus bacterial spot, a minor disease of citrus nursery plants and X. campestris pv. campestris (Xc) is a systemic pathogen that causes black rot of cabbage. Xanthomonas spp. form biofilms in planta that facilitate the host infection process. Herein, the role of extracellular DNA (eDNA) was evaluated in the formation and stabilization of the biofilm matrix at different stages of biofilm development. Fluorescence and light microscopy, as well as DNAse treatments, were used to determine the presence of eDNA in biofilms and bacterial cultures. DNAse treatments of Xcc strains and Xac reduced biofilm formation at the initial stage of development, as well as disrupted preformed biofilm. By comparison, no significant effect of the DNAse was detected for biofilm formation by Xc. DNAse effects on biofilm formation or disruption varied among Xcc strains and Xanthomonas species which suggest different roles for eDNA. Variation in the structure of fibers containing eDNA in biofilms, bacterial cultures, and in twitching motility was also visualized by microscopy. The proposed roles for eDNA are as an adhesin in the early stages of biofilm formation, as an structural component of mature bacterial aggregates, and twitching motility structures.

  4. Comparative analysis of the predicted secretomes of Rosaceae scab pathogens Venturia inaequalis and V. pirina reveals expanded effector families and putative determinants of host range.

    Science.gov (United States)

    Deng, Cecilia H; Plummer, Kim M; Jones, Darcy A B; Mesarich, Carl H; Shiller, Jason; Taranto, Adam P; Robinson, Andrew J; Kastner, Patrick; Hall, Nathan E; Templeton, Matthew D; Bowen, Joanna K

    2017-05-02

    Fungal plant pathogens belonging to the genus Venturia cause damaging scab diseases of members of the Rosaceae. In terms of economic impact, the most important of these are V. inaequalis, which infects apple, and V. pirina, which is a pathogen of European pear. Given that Venturia fungi colonise the sub-cuticular space without penetrating plant cells, it is assumed that effectors that contribute to virulence and determination of host range will be secreted into this plant-pathogen interface. Thus the predicted secretomes of a range of isolates of Venturia with distinct host-ranges were interrogated to reveal putative proteins involved in virulence and pathogenicity. Genomes of Venturia pirina (one European pear scab isolate) and Venturia inaequalis (three apple scab, and one loquat scab, isolates) were sequenced and the predicted secretomes of each isolate identified. RNA-Seq was conducted on the apple-specific V. inaequalis isolate Vi1 (in vitro and infected apple leaves) to highlight virulence and pathogenicity components of the secretome. Genes encoding over 600 small secreted proteins (candidate effectors) were identified, most of which are novel to Venturia, with expansion of putative effector families a feature of the genus. Numerous genes with similarity to Leptosphaeria maculans AvrLm6 and the Verticillium spp. Ave1 were identified. Candidates for avirulence effectors with cognate resistance genes involved in race-cultivar specificity were identified, as were putative proteins involved in host-species determination. Candidate effectors were found, on average, to be in regions of relatively low gene-density and in closer proximity to repeats (e.g. transposable elements), compared with core eukaryotic genes. Comparative secretomics has revealed candidate effectors from Venturia fungal plant pathogens that attack pome fruit. Effectors that are putative determinants of host range were identified; both those that may be involved in race-cultivar and host

  5. Host range of the emerald ash borer (Agrilus planipennis) (Coleoptera: Burprestidae): choice and no-choice tests

    Science.gov (United States)

    Andrea C. Anulewicz; Deborah G. McCullough; David A. Cappaert; Therese M. Poland; Derborah L. Miller

    2007-01-01

    Previous literature on the emerald ash borer (EAB) suggests that, in its native range in Asia, EAB will attack species other than ash (Fraxinus), including Ulmus sp. and Juglans sp. In North America, as ash trees die in the core zone of infestation, concern has been raised about the potential for species other...

  6. Salivary gland hypertrophy virus of house flies in Denmark: Prevalence, host range, and comparison with a Florida isolate.

    Science.gov (United States)

    House flies (Musca domestica) infected with Musca domestica salivary gland hypertrophy virus (MdSGHV) were found in fly populations collected from 12 out of 18 Danish livestock farms that were surveyed in 2007 and 2008. Infection rates ranged from 0.5% to 5% and averaged 1.2% overall. None of the ...

  7. Survey of foliar monoterpenes across the range of jack pine reveal three widespread chemotypes: implications to host expansion of invasive mountain pine beetle

    Directory of Open Access Journals (Sweden)

    Spencer eTaft

    2015-05-01

    Full Text Available The secondary compounds of pines (Pinus can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana has a wide natural distribution range in North America (Canada and USA and thus variations in its secondary compounds, particularly monoterpenes, could affect the host expansion of invasive mountain pine beetle (Dendroctonus ponderosae, which has recently expanded its range into the novel jack pine boreal forest. We investigated monoterpene composition of 601 jack pine trees from natural and provenance forest stands representing 63 populations from Alberta to the Atlantic coast. Throughout its range, jack pine exhibited three chemotypes characterized by high proportions of α-pinene, β-pinene, or limonene. The frequency with which the α-pinene and β-pinene chemotypes occurred at individual sites was correlated to climatic variables, such as continentality and mean annual precipitation, as were the individual α-pinene and β-pinene concentrations. However, other monoterpenes were generally not correlated to climatic variables or geographic distribution. Finally, while the enantiomeric ratios of β-pinene and limonene remained constant across jack pine’s distribution, (‒:(+-α-pinene exhibited two separate trends, thereby delineating two α-pinene phenotypes, both of which occurred across jack pine’s range. These significant variations in jack pine monoterpene composition may have cascading effects on the continued eastward spread and success of D. ponderosae in the Canadian boreal forest.

  8. Pathogen-host associations and predicted range shifts of human monkeypox in response to climate change in central Africa.

    Directory of Open Access Journals (Sweden)

    Henri A Thomassen

    Full Text Available Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV, an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX. Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC, and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4(th Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts.

  9. Pathogen-host associations and predicted range shifts of human monkeypox in response to climate change in central Africa.

    Science.gov (United States)

    Thomassen, Henri A; Fuller, Trevon; Asefi-Najafabady, Salvi; Shiplacoff, Julia A G; Mulembakani, Prime M; Blumberg, Seth; Johnston, Sara C; Kisalu, Neville K; Kinkela, Timothée L; Fair, Joseph N; Wolfe, Nathan D; Shongo, Robert L; LeBreton, Matthew; Meyer, Hermann; Wright, Linda L; Muyembe, Jean-Jacques; Buermann, Wolfgang; Okitolonda, Emile; Hensley, Lisa E; Lloyd-Smith, James O; Smith, Thomas B; Rimoin, Anne W

    2013-01-01

    Climate change is predicted to result in changes in the geographic ranges and local prevalence of infectious diseases, either through direct effects on the pathogen, or indirectly through range shifts in vector and reservoir species. To better understand the occurrence of monkeypox virus (MPXV), an emerging Orthopoxvirus in humans, under contemporary and future climate conditions, we used ecological niche modeling techniques in conjunction with climate and remote-sensing variables. We first created spatially explicit probability distributions of its candidate reservoir species in Africa's Congo Basin. Reservoir species distributions were subsequently used to model current and projected future distributions of human monkeypox (MPX). Results indicate that forest clearing and climate are significant driving factors of the transmission of MPX from wildlife to humans under current climate conditions. Models under contemporary climate conditions performed well, as indicated by high values for the area under the receiver operator curve (AUC), and tests on spatially randomly and non-randomly omitted test data. Future projections were made on IPCC 4(th) Assessment climate change scenarios for 2050 and 2080, ranging from more conservative to more aggressive, and representing the potential variation within which range shifts can be expected to occur. Future projections showed range shifts into regions where MPX has not been recorded previously. Increased suitability for MPX was predicted in eastern Democratic Republic of Congo. Models developed here are useful for identifying areas where environmental conditions may become more suitable for human MPX; targeting candidate reservoir species for future screening efforts; and prioritizing regions for future MPX surveillance efforts.

  10. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia.

    Science.gov (United States)

    Mostert, Diane; Molina, Agustin B; Daniells, Jeff; Fourie, Gerda; Hermanto, Catur; Chao, Chih-Ping; Fabregar, Emily; Sinohin, Vida G; Masdek, Nik; Thangavelu, Raman; Li, Chunyu; Yi, Ganyun; Mostert, Lizel; Viljoen, Altus

    2017-01-01

    Fusarium oxysporum formae specialis cubense (Foc) is a soil-borne fungus that causes Fusarium wilt, which is considered to be the most destructive disease of bananas. The fungus is believed to have evolved with its host in the Indo-Malayan region, and from there it was spread to other banana-growing areas with infected planting material. The diversity and distribution of Foc in Asia was investigated. A total of 594 F. oxysporum isolates collected in ten Asian countries were identified by vegetative compatibility groups (VCGs) analysis. To simplify the identification process, the isolates were first divided into DNA lineages using PCR-RFLP analysis. Six lineages and 14 VCGs, representing three Foc races, were identified in this study. The VCG complex 0124/5 was most common in the Indian subcontinent, Vietnam and Cambodia; whereas the VCG complex 01213/16 dominated in the rest of Asia. Sixty-nine F. oxysporum isolates in this study did not match any of the known VCG tester strains. In this study, Foc VCG diversity in Bangladesh, Cambodia and Sri Lanka was determined for the first time and VCGs 01221 and 01222 were first reported from Cambodia and Vietnam. New associations of Foc VCGs and banana cultivars were recorded in all the countries where the fungus was collected. Information obtained in this study could help Asian countries to develop and implement regulatory measures to prevent the incursion of Foc into areas where it does not yet occur. It could also facilitate the deployment of disease resistant banana varieties in infested areas.

  11. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia

    Science.gov (United States)

    Molina, Agustin B.; Daniells, Jeff; Fourie, Gerda; Hermanto, Catur; Chao, Chih-Ping; Fabregar, Emily; Sinohin, Vida G.; Masdek, Nik; Thangavelu, Raman; Li, Chunyu; Yi, Ganyun; Mostert, Lizel; Viljoen, Altus

    2017-01-01

    Fusarium oxysporum formae specialis cubense (Foc) is a soil-borne fungus that causes Fusarium wilt, which is considered to be the most destructive disease of bananas. The fungus is believed to have evolved with its host in the Indo-Malayan region, and from there it was spread to other banana-growing areas with infected planting material. The diversity and distribution of Foc in Asia was investigated. A total of 594 F. oxysporum isolates collected in ten Asian countries were identified by vegetative compatibility groups (VCGs) analysis. To simplify the identification process, the isolates were first divided into DNA lineages using PCR-RFLP analysis. Six lineages and 14 VCGs, representing three Foc races, were identified in this study. The VCG complex 0124/5 was most common in the Indian subcontinent, Vietnam and Cambodia; whereas the VCG complex 01213/16 dominated in the rest of Asia. Sixty-nine F. oxysporum isolates in this study did not match any of the known VCG tester strains. In this study, Foc VCG diversity in Bangladesh, Cambodia and Sri Lanka was determined for the first time and VCGs 01221 and 01222 were first reported from Cambodia and Vietnam. New associations of Foc VCGs and banana cultivars were recorded in all the countries where the fungus was collected. Information obtained in this study could help Asian countries to develop and implement regulatory measures to prevent the incursion of Foc into areas where it does not yet occur. It could also facilitate the deployment of disease resistant banana varieties in infested areas. PMID:28719631

  12. The distribution and host range of the banana Fusarium wilt fungus, Fusarium oxysporum f. sp. cubense, in Asia.

    Directory of Open Access Journals (Sweden)

    Diane Mostert

    Full Text Available Fusarium oxysporum formae specialis cubense (Foc is a soil-borne fungus that causes Fusarium wilt, which is considered to be the most destructive disease of bananas. The fungus is believed to have evolved with its host in the Indo-Malayan region, and from there it was spread to other banana-growing areas with infected planting material. The diversity and distribution of Foc in Asia was investigated. A total of 594 F. oxysporum isolates collected in ten Asian countries were identified by vegetative compatibility groups (VCGs analysis. To simplify the identification process, the isolates were first divided into DNA lineages using PCR-RFLP analysis. Six lineages and 14 VCGs, representing three Foc races, were identified in this study. The VCG complex 0124/5 was most common in the Indian subcontinent, Vietnam and Cambodia; whereas the VCG complex 01213/16 dominated in the rest of Asia. Sixty-nine F. oxysporum isolates in this study did not match any of the known VCG tester strains. In this study, Foc VCG diversity in Bangladesh, Cambodia and Sri Lanka was determined for the first time and VCGs 01221 and 01222 were first reported from Cambodia and Vietnam. New associations of Foc VCGs and banana cultivars were recorded in all the countries where the fungus was collected. Information obtained in this study could help Asian countries to develop and implement regulatory measures to prevent the incursion of Foc into areas where it does not yet occur. It could also facilitate the deployment of disease resistant banana varieties in infested areas.

  13. Genomic, proteomic and morphological characterization of two novel broad host lytic bacteriophages ΦPD10.3 and ΦPD23.1 infecting pectinolytic Pectobacterium spp. and Dickeya spp.

    Directory of Open Access Journals (Sweden)

    Robert Czajkowski

    Full Text Available Pectinolytic Pectobacterium spp. and Dickeya spp. are necrotrophic bacterial pathogens of many important crops, including potato, worldwide. This study reports on the isolation and characterization of broad host lytic bacteriophages able to infect the dominant Pectobacterium spp. and Dickeya spp. affecting potato in Europe viz. Pectobacterium carotovorum subsp. carotovorum (Pcc, P. wasabiae (Pwa and Dickeya solani (Dso with the objective to assess their potential as biological disease control agents. Two lytic bacteriophages infecting stains of Pcc, Pwa and Dso were isolated from potato samples collected from two potato fields in central Poland. The ΦPD10.3 and ΦPD23.1 phages have morphology similar to other members of the Myoviridae family and the Caudovirales order, with a head diameter of 85 and 86 nm and length of tails of 117 and 121 nm, respectively. They were characterized for optimal multiplicity of infection, the rate of adsorption to the Pcc, Pwa and Dso cells, the latent period and the burst size. The phages were genotypically characterized with RAPD-PCR and RFLP techniques. The structural proteomes of both phages were obtained by fractionation of phage proteins by SDS-PAGE. Phage protein identification was performed by liquid chromatography-mass spectrometry (LC-MS analysis. Pulsed-field gel electrophoresis (PFGE, genome sequencing and comparative genome analysis were used to gain knowledge of the length, organization and function of the ΦPD10.3 and ΦPD23.1 genomes. The potential use of ΦPD10.3 and ΦPD23.1 phages for the biocontrol of Pectobacterium spp. and Dickeya spp. infections in potato is discussed.

  14. Adaptation of a polyphagous herbivore to a novel host plant extensively shapes the transcriptome of herbivore and host

    NARCIS (Netherlands)

    Wybouw, N.; Zhurov, V.; Martel, C.; Bruinsma, K.A.; Hendrickx, F.; Grbić, V.; van Leeuwen, T.

    2015-01-01

    Generalist arthropod herbivores rapidly adapt to a broad range of host plants. However, the extent of transcriptional reprogramming in the herbivore and its hosts associated with adaptation remains poorly understood. Using the spider mite Tetranychus urticae and tomato as models with available

  15. Salivary gland hypertrophy virus of house flies in Denmark: Prevalence, host range, and comparison with a Florida isolate

    DEFF Research Database (Denmark)

    Geden, C. J.; Steenberg, T.; Lietze, V.-U.

    2011-01-01

    House flies (Musca domestica) infected with Musca domestica salivary gland hypertrophy virus (MdSGHV) were found in fly populations collected from 12 out of 18 Danish livestock farms that were surveyed in 2007 and 2008. Infection rates ranged from 0.5% to 5% and averaged 1.2%. None of the stable...... flies (Stomoxys calcitrans), rat-tail maggot flies (Eristalis tenax) or yellow dung flies (Scathophaga stercoraria) collected from MdSGHV-positive farms displayed characteristic salivary gland hypertrophy (SGH). In laboratory transmission tests, SGH symptoms were not observed in stable flies, flesh...... in infected house flies, and injection of house flies with homogenates prepared from the salivary glands or ovaries of these species resulted in MdSGHV infection of the challenged house flies. Mortality of virus-injected stable flies was the highest among the five species tested. Virulence of Danish...

  16. Characteristic miRNA expression signature and random forest survival analysis identify potential cancer-driving miRNAs in a broad range of head and neck squamous cell carcinoma subtypes.

    Science.gov (United States)

    Nunez Lopez, Yury O; Victoria, Berta; Golusinski, Pawel; Golusinski, Wojciech; Masternak, Michal M

    2018-01-01

    To characterize the miRNA expression profile in head and neck squamous cell carcinoma (HNSSC) accounting for a broad range of cancer subtypes and consequently identify an optimal miRNA signature with prognostic value. HNSCC is consistently among the most common cancers worldwide. Its mortality rate is about 50% because of the characteristic aggressive behavior of these cancers and the prevalent late diagnosis. The heterogeneity of the disease has hampered the development of robust prognostic tools with broad clinical utility. The Cancer Genome Atlas HNSC dataset was used to analyze level 3 miRNA-Seq data from 497 HNSCC patients. Differential expression (DE) analysis was implemented using the limma package and multivariate linear model that adjusted for the confounding effects of age at diagnosis, gender, race, alcohol history, anatomic neoplasm subdivision, pathologic stage, T and N stages, and vital status. Random forest (RF) for survival analysis was implemented using the randomForestSRC package. A characteristic DE miRNA signature of HNSCC, comprised of 11 upregulated (i.e., miR-196b-5p, miR-1269a, miR-196a-5p, miR-4652-3p, miR-210-3p, miR-1293, miR-615-3p, miR-503-5p, miR-455-3p, miR-205-5p, and miR-21-5p) and 9 downregulated (miR-376c-3p, miR-378c, miR-29c-3p, miR-101-3p, miR-195-5p, miR-299-5p, miR-139-5p, miR-6510-3p, miR-375) miRNAs was identified. An optimal RF survival model was built from seven variables including age at diagnosis, miR-378c, miR-6510-3p, stage N, pathologic stage, gender, and race (listed in order of variable importance). The joint differential miRNA expression and survival analysis controlling for multiple confounding covariates implemented in this study allowed for the identification of a previously undetected prognostic miRNA signature characteristic of a broad range of HNSCC.

  17. Salmonella Pathogenicity and Host Adaptation in Chicken-Associated Serovars

    Science.gov (United States)

    Johnson, Timothy J.; Ricke, Steven C.; Nayak, Rajesh; Danzeisen, Jessica

    2013-01-01

    SUMMARY Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today. PMID:24296573

  18. The entomopathogenic nematode Heterorhabditis megidis: host searching behaviour, infectivity and reproduction

    NARCIS (Netherlands)

    Boff, M.I.C.

    2001-01-01

    Entomopathogenic nematodes in the families Heterorhabditidae and Steinernematidae have considerable potential as biological control agents of soil-inhabiting insect pests. Attributes making these nematodes ideal biological control agents include their broad host range, high virulence,

  19. Mixed quantum/classical calculations of total and differential elastic and rotationally inelastic scattering cross sections for light and heavy reduced masses in a broad range of collision energies.

    Science.gov (United States)

    Semenov, Alexander; Babikov, Dmitri

    2014-01-28

    The mixed quantum/classical theory (MQCT) for rotationally inelastic scattering developed recently [A. Semenov and D. Babikov, J. Chem. Phys. 139, 174108 (2013)] is benchmarked against the full quantum calculations for two molecular systems: He + H2 and Na + N2. This allows testing new method in the cases of light and reasonably heavy reduced masses, for small and large rotational quanta, in a broad range of collision energies and rotational excitations. The resultant collision cross sections vary through ten-orders of magnitude range of values. Both inelastic and elastic channels are considered, as well as differential (over scattering angle) cross sections. In many cases results of the mixed quantum/classical method are hard to distinguish from the full quantum results. In less favorable cases (light masses, larger quanta, and small collision energies) some deviations are observed but, even in the worst cases, they are within 25% or so. The method is computationally cheap and particularly accurate at higher energies, heavier masses, and larger densities of states. At these conditions MQCT represents a useful alternative to the standard full-quantum scattering theory.

  20. Development of a Broad-Range 23S rDNA Real-Time PCR Assay for the Detection and Quantification of Pathogenic Bacteria in Human Whole Blood and Plasma Specimens

    Directory of Open Access Journals (Sweden)

    Paolo Gaibani

    2013-01-01

    Full Text Available Molecular methods are important tools in the diagnosis of bloodstream bacterial infections, in particular in patients treated with antimicrobial therapy, due to their quick turn-around time. Here we describe a new broad-range real-time PCR targeting the 23S rDNA gene and capable to detect as low as 10 plasmid copies per reaction of targeted bacterial 23S rDNA gene. Two commercially available DNA extraction kits were evaluated to assess their efficiency for the extraction of plasma and whole blood samples spiked with different amount of either Staphylococcus aureus or Escherichia coli, in order to find the optimal extraction method to be used. Manual QIAmp extraction method with enzyme pre-treatment resulted the most sensitive for detection of bacterial load. Sensitivity of this novel assay ranged between 10 and 103 CFU per PCR reaction for E. coli and S. aureus in human whole blood samples depending on the extraction methods used. Analysis of plasma samples showed a 10- to 100-fold reduction of bacterial 23S rDNA in comparison to the corresponding whole blood specimens, thus indicating that whole blood is the preferential sample type to be used in this real-time PCR protocol. Our results thus show that the 23S rDNA gene represents an optimal target for bacteria quantification in human whole blood.

  1. Development of a broad-range 23S rDNA real-time PCR assay for the detection and quantification of pathogenic bacteria in human whole blood and plasma specimens.

    Science.gov (United States)

    Gaibani, Paolo; Mariconti, Mara; Bua, Gloria; Bonora, Sonia; Sassera, Davide; Landini, Maria Paola; Mulatto, Patrizia; Novati, Stefano; Bandi, Claudio; Sambri, Vittorio

    2013-01-01

    Molecular methods are important tools in the diagnosis of bloodstream bacterial infections, in particular in patients treated with antimicrobial therapy, due to their quick turn-around time. Here we describe a new broad-range real-time PCR targeting the 23S rDNA gene and capable to detect as low as 10 plasmid copies per reaction of targeted bacterial 23S rDNA gene. Two commercially available DNA extraction kits were evaluated to assess their efficiency for the extraction of plasma and whole blood samples spiked with different amount of either Staphylococcus aureus or Escherichia coli, in order to find the optimal extraction method to be used. Manual QIAmp extraction method with enzyme pre-treatment resulted the most sensitive for detection of bacterial load. Sensitivity of this novel assay ranged between 10 and 10(3) CFU per PCR reaction for E. coli and S. aureus in human whole blood samples depending on the extraction methods used. Analysis of plasma samples showed a 10- to 100-fold reduction of bacterial 23S rDNA in comparison to the corresponding whole blood specimens, thus indicating that whole blood is the preferential sample type to be used in this real-time PCR protocol. Our results thus show that the 23S rDNA gene represents an optimal target for bacteria quantification in human whole blood.

  2. Infection of human cancer cells with myxoma virus requires Akt activation via interaction with a viral ankyrin-repeat host range factor.

    Science.gov (United States)

    Wang, Gen; Barrett, John W; Stanford, Marianne; Werden, Steven J; Johnston, James B; Gao, Xiujuan; Sun, Mei; Cheng, Jin Q; McFadden, Grant

    2006-03-21

    We demonstrate that the susceptibility of human cancer cells to be infected and killed by an oncolytic poxvirus, myxoma virus (MV), is related to the basal level of endogenous phosphorylated Akt. We further demonstrate that nonpermissive tumor cells will switch from resistant to susceptible for MV infection after expression of ectopically active Akt (Myr-Akt) and that permissive cancer cells can be rendered nonpermissive by blocking Akt activation with a dominant-negative inhibitor of Akt. Finally, the activation of Akt by MV involves the formation of a complex between the viral host range ankyrin-repeat protein, M-T5, and Akt. We conclude that the Akt pathway is a key restriction determinant for permissiveness of human cancer cells by MV.

  3. Six host range variants of the xenotropic/polytropic gammaretroviruses define determinants for entry in the XPR1 cell surface receptor

    Directory of Open Access Journals (Sweden)

    Kozak Christine A

    2009-10-01

    Full Text Available Abstract Background The evolutionary interactions between retroviruses and their receptors result in adaptive selection of restriction variants that can allow natural populations to evade retrovirus infection. The mouse xenotropic/polytropic (X/PMV gammaretroviruses rely on the XPR1 cell surface receptor for entry into host cells, and polymorphic variants of this receptor have been identified in different rodent species. Results We screened a panel of X/PMVs for infectivity on rodent cells carrying 6 different XPR1 receptor variants. The X/PMVs included 5 well-characterized laboratory and wild mouse virus isolates as well as a novel cytopathic XMV-related virus, termed Cz524, isolated from an Eastern European wild mouse-derived strain, and XMRV, a xenotropic-like virus isolated from human prostate cancer. The 7 viruses define 6 distinct tropisms. Cz524 and another wild mouse isolate, CasE#1, have unique species tropisms. Among the PMVs, one Friend isolate is restricted by rat cells. Among the XMVs, two isolates, XMRV and AKR6, differ from other XMVs in their PMV-like restriction in hamster cells. We generated a set of Xpr1 mutants and chimeras, and identified critical amino acids in two extracellular loops (ECLs that mediate entry of these different viruses, including 3 residues in ECL3 that are involved in PMV entry (E500, T507, and V508 and can also influence infectivity by AKR6 and Cz524. Conclusion We used a set of natural variants and mutants of Xpr1 to define 6 distinct host range variants among naturally occurring X/PMVs (2 XMV variants, 2 PMVs, 2 different wild mouse variants. We identified critical amino acids in XPR1 that mediate entry of these viruses. These gammaretroviruses and their XPR1 receptor are thus highly functionally polymorphic, a consequence of the evolutionary pressures that favor both host resistance and virus escape mutants. This variation accounts for multiple naturally occurring virus resistance phenotypes and

  4. Geochemistry and geochronology of carbonate-hosted base metal deposits in the southern Brooks Range, Alaska: temporal association with VMS deposits and metallogenic implications

    Science.gov (United States)

    Kelly, Karen; Slack, John; Selby, David

    2009-01-01

    The Brooks Range contains enormous accumulations of zinc and copper, either as VMS or sediment-hosted deposits. The Ruby Creek and Omar deposits are Cu-Co stratabound deposits associated with dolomitic breccias. Numerous volcanogenic Cu-Zn (+/-Ag, Au) deposits are situated ~20 km north of the Ruby Creek deposit. The carbonate-hosted deposits consist of chalcopyrite and bornite that fill open spaces, replace the matrix of the breccias, and occur in later cross-cutting veins. Cobaltiferous pyrite, chalcocite, minor tennantite-tetrahedrite, galena, and sphalerite are also present. At Ruby Creek, phases such as carrollite, renierite, and germanite occur rarely. The deposits have undergone post-depositional metamorphism (Ruby Creek, low greenschist facies; Omar, blueschist facies). The unusual geochemical signature includes Cu-Co +/- Ag, As, Au, Bi, Ge, Hg, Sb, and U with sporadic high Re concentrations (up to 2.7 ppm). New Re-Os data were obtained for chalcopyrite, bornite, and pyrite from the Ruby Creek deposit (analyses of sulfides from Omar are in progress). The data show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the Ruby Creek deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization occurred at 384 +/-4.2 Ma, which coincides with zircon U-Pb ages from igneous rocks that are spatially and genetically associated with VMS deposits. This suggests a temporal link between regional magmatism and hydrothermal mineralization.

  5. Fundamental host range of Pseudophilothrips ichini s.l. (Thysanoptera: Phlaeothripidae): a candidate biological control agent of Schinus terebinthifolius (Sapindales: Anacardiaceae) in the United States.

    Science.gov (United States)

    Cuda, J P; Medal, J C; Gillmore, J L; Habeck, D H; Pedrosa-Macedo, J H

    2009-12-01

    Schinus terebinthifolius Raddi (Sapindales: Anacardiaceae) is a non-native perennial woody plant that is one of the most invasive weeds in Florida, Hawaii, and more recently California and Texas. This plant was introduced into Florida from South America as a landscape ornamental in the late 19th century, eventually escaped cultivation, and now dominates entire ecosystems in south-central Florida. Recent DNA studies have confirmed two separate introductions of S. terebinthifolius in Florida, and there is evidence of hybridization. A thrips, Pseudophilothrips ichini s.l. (Hood) (Thysanoptera: Phlaeothripidae), is commonly found attacking shoots and flowers of S. terebinthifolius in Brazil. Immatures and occasionally adults form large aggregations on young terminal growth (stems and leaves) of the plant. Feeding damage by P. ichini s.l. frequently kills new shoots, which reduces vigor and restricts growth of S. terebinthifolius. Greenhouse and laboratory host range tests with 46 plant species in 18 families and 10 orders were conducted in Paraná, Brazil, and Florida. Results of no-choice, paired-choice, and multiple-choice tests indicated that P. ichini s.l. is capable of reproducing only on S. terebinthifolius and possibly Schinus molle L., an ornamental introduced into California from Peru that has escaped cultivation and is considered invasive. Our results showed that P. ichini s.l. posed minimal risk to mature S. molle plants or the Florida native Metopium toxiferum L. Krug and Urb. In May 2007, the federal interagency Technical Advisory Group for Biological Control Agents of Weeds (TAG) concluded P. ichini s.l. was sufficiently host specific to recommend its release from quarantine.

  6. Evidence of expanded host range and mammalian-associated genetic changes in a duck H9N2 influenza virus following adaptation in quail and chickens.

    Directory of Open Access Journals (Sweden)

    Md Jaber Hossain

    Full Text Available H9N2 avian influenza viruses continue to circulate worldwide; in Asia, H9N2 viruses have caused disease outbreaks and established lineages in land-based poultry. Some H9N2 strains are considered potentially pandemic because they have infected humans causing mild respiratory disease. In addition, some of these H9N2 strains replicate efficiently in mice without prior adaptation suggesting that H9N2 strains are expanding their host range. In order to understand the molecular basis of the interspecies transmission of H9N2 viruses, we adapted in the laboratory a wildtype duck H9N2 virus, influenza A/duck/Hong Kong/702/79 (WT702 virus, in quail and chickens through serial lung passages. We carried out comparative analysis of the replication and transmission in quail and chickens of WT702 and the viruses obtained after 23 serial passages in quail (QA23 followed by 10 serial passages in chickens (QA23CkA10. Although the WT702 virus can replicate and transmit in quail, it replicates poorly and does not transmit in chickens. In contrast, the QA23CkA10 virus was very efficient at replicating and transmitting in quail and chickens. Nucleotide sequence analysis of the QA23 and QA23CkA10 viruses compared to the WT702 virus indicated several nucleotide substitutions resulting in amino acid changes within the surface and internal proteins. In addition, a 21-amino acid deletion was found in the stalk of the NA protein of the QA23 virus and was maintained without further modification in the QA23CkA10 adapted virus. More importantly, both the QA23 and the QA23CkA10 viruses, unlike the WT702 virus, were able to readily infect mice, produce a large-plaque phenotype, showed faster replication kinetics in tissue culture, and resulted in the quick selection of the K627 amino acid mammalian-associated signature in PB2. These results are in agreement with the notion that adaptation of H9 viruses to land-based birds can lead to strains with expanded host range.

  7. The Cotesia sesamiae story: insight into host-range evolution in a Hymenoptera parasitoid and implication for its use in biological control programs.

    Science.gov (United States)

    Kaiser, L; Dupas, S; Branca, A; Herniou, E A; Clarke, C W; Capdevielle Dulac, C; Obonyo, J; Benoist, R; Gauthier, J; Calatayud, P A; Silvain, J F; Le Ru, B P

    2017-12-01

    This review covers nearly 20 years of studies on the ecology, physiology and genetics of the Hymenoptera Cotesia sesamiae, an African parasitoid of Lepidoptera that reduces populations of common maize borers in East and South Africa. The first part of the review presents studies based on sampling of C. sesamiae from maize crops in Kenya. From this agrosystem including one host plant and three main host borer species, studies revealed two genetically differentiated populations of C. sesamiae species adapted to their local host community, and showed that their differentiation involved the joint evolution of virulence genes and sensory mechanisms of host acceptance, reinforced by reproductive incompatibility due to Wolbachia infection status and natural inbreeding. In the second part, we consider the larger ecosystem of wild Poales plant species hosting many Lepidoptera stem borer species that are potential hosts for C. sesamiae. The hypothesis of other host-adapted C. sesamiae populations was investigated based on a large sampling of stem borer larvae on various Poales across sub-Saharan Africa. The sampling provided information on the respective contribution of local hosts, biogeography and Wolbachia in the genetic structure of C. sesamiae populations. Molecular evolution analyses highlighted that several bracovirus genes were under positive selection, some of them being under different selection pressure in C. sesamiae populations adapted to different hosts. This suggests that C. sesamiae host races result from co-evolution acting at the local scale on different bracovirus genes. The third part considers the mechanisms driving specialization. C. sesamiae host races are more or less host-specialized. This character is crucial for efficient and environmentally-safe use of natural enemies for biological control of pests. One method to get an insight in the evolutionary stability of host-parasite associations is to characterize the phylogenetic relationships between

  8. Reconnaissance exploration geochemistry in the central Brooks Range, northern Alaska: Implications for exploration of sediment-hosted zinc-lead-silver deposits

    Science.gov (United States)

    Kelley, K.D.; Kelley, D.L.

    1992-01-01

    A reconnaissance geochemical survey was conducted in the southern Killik River quadrangle, central Brooks Range, northern Alaska. The Brooks Range lies within the zone of continuous permafrost which may partially inhibit chemical weathering and oxidation. The minus 30-mesh and nonmagnetic heavy-mineral concentrate fractions of sediment samples were chosen as the sample media for the survey so that mechanical rather than chemical dispersion patterns would be enhanced. A total of 263 sites were sampled within the southern half of the Killik River quadrangle at an average sample density of approximately one sample per 12 km2. All samples were submitted for multi-element analyses. In the western and central Brooks Range, several known sediment-hosted Zn-Pb-Ag(-Ba) deposits occur within a belt of Paleozoic rocks of the Endicott Mountains allochthon. Exploration for this type of deposit in the Brook Range is difficult, due to the inherently high background values for Ba, Zn and Pb in shale and the common occurrence of metamorphic quartz-calcite veins, many of which contain traces of sulfide minerals. Stream sediments derived from these sources produce numerous geochemical anomalies which are not necessarily associated with significant mineralization. R-mode factor analysis provides a means of distinguishing between element associations related to lithology and those related to possible mineralization. Factor analysis applied to the multi-element data from the southern Killik River quadrangle resulted in the discovery of two additional Zn-Pb-Ag mineral occurrences of considerable areal extent which are 80-100 km east of any previously known deposit. These have been informally named the Kady and Vidlee. Several lithogeochemical element associations, or factors, and three factors which represent sulfide mineralization were identified: Ag-Pb-Zn (galena and sphalerite) and Fe-Ni-Co-Cu (pyrite ?? chalcopyrite) in the concentrate samples and Cd-Zn-Pb-As-Mn in the sediment

  9. Disruption of M-T5, a novel myxoma virus gene member of poxvirus host range superfamily, results in dramatic attenuation of myxomatosis in infected European rabbits.

    Science.gov (United States)

    Mossman, K; Lee, S F; Barry, M; Boshkov, L; McFadden, G

    1996-07-01

    Myxoma virus is a pathogenic poxvirus that induces a lethal myxomatosis disease profile in European rabbits, which is characterized by fulminating lesions at the primary site of inoculation, rapid dissemination to secondary internal organs and peripheral external sites, and supervening gram-negative bacterial infection. Here we describe the role of a novel myxoma virus protein encoded by the M-T5 open reading frame during pathogenesis. The myxoma virus M-T5 protein possesses no significant sequence homology to nonviral proteins but is a member of a larger poxviral superfamily designated host range proteins. An M-T5- mutant virus was constructed by disruption of both copies of the M-T5 gene followed by insertion of the selectable marker p7.5Ecogpt. Although the M-T5- deletion mutant replicated with wild-type kinetics in rabbit fibroblasts, infection of a rabbit CD4+ T-cell line (RL5) with the myxoma virus M-T5- mutant virus resulted in the rapid and complete cessation of both host and viral protein synthesis, accompanied by the manifestation of all the classical features of programmed cell death. Infection of primary rabbit peripheral mononuclear cells with the myxoma virus M-T5-mutant virus resulted in the apoptotic death of nonadherent lymphocytes but not adherent monocytes. Within the European rabbit, disruption of the M-T5 open reading frame caused a dramatic attenuation of the rapidly lethal myxomatosis infection, and none of the infected rabbits displayed any of the characteristic features of myxomatosis. The two most significant histological observations in rabbits infected with the M-T5-mutant virus were (i) the lack of progression of the infection past the primary site of inoculation, coupled with the establishment of a rapid and effective inflammatory reaction, and (ii) the inability of the virus to initiate a cellular reaction within secondary immune organs. We conclude that M-T5 functions as a critical virulence factor by allowing productive infection of

  10. The 2010 Broad Prize

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    A new data analysis, based on data collected as part of The Broad Prize process, provides insights into which large urban school districts in the United States are doing the best job of educating traditionally disadvantaged groups: African-American, Hispanics, and low-income students. Since 2002, The Eli and Edythe Broad Foundation has awarded The…

  11. Broad ligament ectopic pregnancy

    OpenAIRE

    Rama C; Lepakshi G; Raju SN

    2015-01-01

    Pregnancy in the broad ligament is a rare form of ectopic pregnancy with a high risk of maternal mortality. Ultrasonography may help in the early diagnosis but mostly the diagnosis is established during surgery. We report the case of a patient with broad ligament ectopic pregnancy diagnosed intraoperatively. The patient had uneventful postoperative recovery.

  12. Infection with host-range mutant adenovirus 5 suppresses innate immunity and induces systemic CD4+ T cell activation in rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Huma Qureshi

    Full Text Available Ad5 is a common cause of respiratory disease and an occasional cause of gastroenteritis and conjunctivitis, and seroconversion before adolescence is common in humans. To gain some insight into how Ad5 infection affects the immune system of rhesus macaques (RM 18 RM were infected with a host-range mutant Ad5 (Ad5hr by 3 mucosal inoculations. There was a delay of 2 to 6 weeks after the first inoculation before plasmacytoid dendritic cell (pDC frequency and function increased in peripheral blood. Primary Ad5hr infection suppressed IFN-γ mRNA expression, but the second Ad5hr exposure induced a rapid increase in IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC. Primary Ad5hr infection suppressed CCL20, TNF and IL-1 mRNA expression in PBMC, and subsequent virus exposures further dampened expression of these pro-inflammatory cytokines. Primary, but not secondary, Ad5hr inoculation increased the frequency of CXCR3+ CD4+ T cells in blood, while secondary, but not primary, Ad5hr infection transiently increased the frequencies of Ki67+, HLADR+ and CD95+/CCR5+ CD4+ T cells in blood. Ad5hr infection induced polyfunctional CD4 and CD8+ T cells specific for the Ad5 hexon protein in all of the animals. Thus, infection with Ad5hr induced a complex pattern of innate and adaptive immunity in RM that included transient systemic CD4+ T cell activation and suppressed innate immunity on re-exposure to the virus. The complex effects of adenovirus infection on the immune system may help to explain the unexpected results of testing Ad5 vector expressing HIV antigens in Ad5 seropositive people.

  13. Giant Broad Line Regions in Dwarf Seyferts

    Indian Academy of Sciences (India)

    High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some cases, rival those ...

  14. The current Salmonella–host interactome

    Science.gov (United States)

    Schleker, Sylvia; Sun, Jingchun; Raghavan, Balachandran; Srnec, Matthew; Müller, Nicole; Koepfinger, Mary; Murthy, Leelavati; Zhao, Zhongming; Klein-Seetharaman, Judith

    2011-01-01

    Salmonella bacteria cause millions of infections and thousands of deaths every year. This pathogen has an unusually broad host range including humans, animals, and even plants. During infection, Salmonella expresses a variety of virulence factors and effectors that are delivered into the host cell triggering cellular responses through protein–protein interactions (PPIs) with host cell proteins which make the pathogen’s invasion and replication possible. To speed up proteomic efforts in elucidating Salmonella–host interactomes, we carried out a survey of the currently published Salmonella–host PPI. Such a list can serve as the gold standard for computational models aimed at predicting Salmonella–host interactomes through integration of large-scale biological data sources. Manual literature and database search of >2200 journal articles and >100 databases resulted in a gold standard list of currently 62 PPI, including primarily interactions of Salmonella proteins with human and mouse proteins. Only six of these interactions were directly retrievable from PPI databases and 16 were highlighted in databases featuring literature extracts. Thus, the literature survey resulted in the most complete interactome available to date for Salmonella. Pathway analysis using Ingenuity and Broad Gene Set Enrichment Analysis (GSEA) software revealed among general pathways such as MAPK signaling in particular those related to cell death as well as cell morphology, turnover, and interactions, in addition to response to not only Salmonella but also other pathogenic – viral and bacterial – infections. The list of interactions is available at http://www.shiprec.org/indicationslist.htm PMID:22213674

  15. The role of innate Immunity and host specificity in Salmonella infection in vitro

    OpenAIRE

    Walk, Nicole

    2012-01-01

    Salmonella serovars are important zoonotic pathogens, and can cause severe infections in both humans and animals. In the study presented here, comparative in vitro infection studies were performed in two, established cell types (epithelia and macrophage) derived from three different host species origins (porcine, murine and human). Both host-adapted and broad host-range S. enterica spp. enterica serovars (S. Typhimurium, S. Choleraesius, S. Dublin und S. Enteritidis) were used for the infecti...

  16. The freshwater sponge Ephydatia fluviatilis harbours diverse Pseudomonas species (Gammaproteobacteria, Pseudomonadales) with broad-spectrum antimicrobial activity

    NARCIS (Netherlands)

    Keller-Costa, Tina; Jousset, Alexandre; van Overbeek, Leo; van Elsas, Jan Dirk; Costa, Rodrigo

    2014-01-01

    Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is

  17. The Freshwater Sponge Ephydatia fluviatilis Harbours Diverse Pseudomonas Species (Gammaproteobacteria, Pseudomonadales) with Broad-Spectrum Antimicrobial Activity

    NARCIS (Netherlands)

    Keller-Costa, T.; Jousset, A.; Overbeek, van L.S.; Elsas, J.D.; Costa, R.

    2014-01-01

    Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is

  18. Trace metal concentrations in single specimens of the intestinal broad flatworm ( Diphyllobothrium latum), compared to their fish host ( Oncorhynchus mykiss) measured by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, Stefan; Mages, Margarete; Torres, Patricio

    2008-12-01

    The aim of this study was to investigate (1) whether intestine endoparasites ( Diphyllobothrium latum) accumulate trace elements related to its body size and (2) whether parasites bioconcentrate more trace elements than their host. Freshwater fish (rainbow trout Oncorhynchus mykiss) were sampled in the deep, oligotrophic and uncontaminated Lake Riñihue in Southern Chile. The element concentration of different organs (intestine, muscle, liver) and of the intestine endoparasites were analyzed using total reflection X-ray fluorescence spectrometry. The results showed that the mass fraction for Mn, Fe, Ni, Cu, and Pb decreased significantly with the body size (dry weight) of the endoparasite. Only Zn did not reveal such a relationship. Small parasites accumulated up to 80 times more Fe, Ni, Mn, Pb, and Cu than large parasites. Compared to the fish organs, small parasites accumulated in maximum 35 to 307 times more Mn, 5 to 255 times more Fe, 98 to 220 times more Ni, 3 to 175 times more Cu, and 0.4 to 12 times more Zn than the fish. Lead was only found in the endoparasite, but not in the fish organs. We conclude that (1) D. latum is a good indicator for trace element accumulation in fishes and that (2) small endoparasites are more sensitive as bioindicators because they showed higher bioconcentrations of trace metals than larger parasites.

  19. Diversity and Geographical Distribution of Flavobacterium psychrophilum Isolates and Their Phages: Patterns of Susceptibility to Phage Infection and Phage Host Range

    DEFF Research Database (Denmark)

    Castillo, Daniel; Christiansen, Rói Hammershaimb; Espejo, Romilio

    2014-01-01

    in disease control requires detailed knowledge about the diversity and dynamics of host susceptibility to phage infection. For this reason, we examined the genetic diversity of 49 F. psychrophilum strains isolated in three different areas (Chile, Denmark, and USA) through direct genome restriction enzyme...

  20. Triad of human cellular proteins, IRF2, FAM111A, and RFC3, restrict replication of orthopoxvirus SPI-1 host-range mutants.

    Science.gov (United States)

    Panda, Debasis; Fernandez, Daniel J; Lal, Madhu; Buehler, Eugen; Moss, Bernard

    2017-04-04

    Viruses and their hosts can reach balanced states of evolution ensuring mutual survival, which makes it difficult to appreciate the underlying dynamics. To uncover hidden interactions, virus mutants that have lost defense genes may be used. Deletion of the gene that encodes serine protease inhibitor 1 (SPI-1) of rabbitpox virus and vaccinia virus, two closely related orthopoxviruses, prevents their efficient replication in human cells, whereas certain other mammalian cells remain fully permissive. Our high-throughput genome-wide siRNA screen identified host factors that prevent reproduction and spread of the mutant viruses in human cells. More than 20,000 genes were interrogated with individual siRNAs and those that prominently increased replication of the SPI-1 deletion mutant were subjected to a secondary screen. The top hits based on the combined data-replication factor C3 (RFC3), FAM111A, and interferon regulatory factor 2 (IRF2)-were confirmed by custom assays. The siRNAs to RFC1, RFC2, RFC4, and RFC5 mRNAs also enhanced spread of the mutant virus, strengthening the biological significance of the RFC complex as a host restriction factor for poxviruses. Whereas association with proliferating cell nuclear antigen and participation in processive genome replication are common features of FAM111A and RFC, IRF2 is a transcriptional regulator. Microarray analysis, quantitative RT-PCR, and immunoblotting revealed that IRF2 regulated the basal level expression of FAM111A, suggesting that the enhancing effect of depleting IRF2 on replication of the SPI-1 mutant was indirect. Thus, the viral SPI-1 protein and the host IRF2, FAM111A, and RFC complex likely form an interaction network that influences the ability of poxviruses to replicate in human cells.

  1. Draft genome sequences of 53 genetically distinct isolates of Bordetella bronchiseptica representing 11 terrestrial and aquatic hosts

    Science.gov (United States)

    Bordetella bronchiseptica infects a variety of mammalian and avian hosts. Here we report the genome sequences of 53 genetically distinct isolates, acquired from a broad range of terrestrial and aquatic animals. These data will greatly facilitate ongoing efforts to better understand evolution, host...

  2. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range

    Science.gov (United States)

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.

    2013-01-01

    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  3. Identification of Restriction Factors by Human Genome-Wide RNA Interference Screening of Viral Host Range Mutants Exemplified by Discovery of SAMD9 and WDR6 as Inhibitors of the Vaccinia Virus K1L-C7L- Mutant.

    Science.gov (United States)

    Sivan, Gilad; Ormanoglu, Pinar; Buehler, Eugen C; Martin, Scott E; Moss, Bernard

    2015-08-04

    RNA interference (RNAi) screens intended to identify host factors that restrict virus replication may fail if the virus already counteracts host defense mechanisms. To overcome this limitation, we are investigating the use of viral host range mutants that exhibit impaired replication in nonpermissive cells. A vaccinia virus (VACV) mutant with a deletion of both the C7L and K1L genes, K1L(-)C7L(-), which abrogates replication in human cells at a step prior to late gene expression, was chosen for this strategy. We carried out a human genome-wide small interfering RNA (siRNA) screen in HeLa cells infected with a VACV K1L(-)C7L(-) mutant that expresses the green fluorescent protein regulated by a late promoter. This positive-selection screen had remarkably low background levels and resulted in the identification of a few cellular genes, notably SAMD9 and WDR6, from approximately 20,000 tested that dramatically enhanced green fluorescent protein expression. Replication of the mutant virus was enabled by multiple siRNAs to SAMD9 or WDR6. Moreover, SAMD9 and WDR6 clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 knockout HeLa cell lines were permissive for replication of the K1L(-)C7L(-) mutant, in agreement with the siRNA data. Expression of exogenous SAMD9 or interferon regulatory factor 1 restricted replication of the K1L(-)C7L(-) mutant in the SAMD9(-/-) cells. Independent interactions of SAMD9 with the K1 and C7 proteins were suggested by immunoprecipitation. Knockout of WDR6 did not reduce the levels of SAMD9 and interactions of WDR6 with SAMD9, C7, and K1 proteins were not detected, suggesting that these restriction factors act independently but possibly in the same innate defense pathway. The coevolution of microbial pathogens with cells has led to an arms race in which the invader and host continuously struggle to gain the advantage. For this reason, traditional siRNA screens may fail to uncover important immune mechanisms if the pathogens

  4. Gama de hospedeiros e reação de genótipos de tomateiro a Pseudomonas cichorii Host range and genotypes reaction to Pseudomonas cichorii

    Directory of Open Access Journals (Sweden)

    Tadeu Antônio Fernandes da Silva Júnior

    2009-06-01

    in two commercial tomato fields in the State of São Paulo in 2005. In view of this, studies were carried out in order to determine the host range of Pseudomonas cichorii isolates (IBSBF 2309 and IBSBF 2323, obtained from tomato plants at commercial fields located in the cities of Bragança Paulista and Mogi Guaçú, SP, Brazil. Caserta pumpkin, lettuce, purslane, eggplant, beet, broccoli, carrot, Jimson weed, sunflower, tobacco, scarlet eggplant, melon, cucumber, petunia, green pepper, radish, cabbage, arugula, parsley, and tomato plants were spray-inoculated separately with two isolates of P. cichorii obtained from tomato and one from sunflower (GIR-1. The isolates IBSBF 2309 and IBSBF 2323 were pathogenic to purslane, Jimson weed, sunflower, green pepper, and tomato; GIR-1 was only pathogenic to purslane, Jimson weed, and sunflower, but not pathogenic to green pepper or tomato. In Brazil, no sources of resistance to this bacterium are known within the Lycopersicon genus. The reaction of tomato cultivars to the bacterium is also unknown. Twenty-eight tomato genotypes from the Sakata Seed Sudamerica Ltda. Germplasm Bank were evaluated for their reaction to P. cichorii isolates IBSBF 2309 and IBSBF 2323, using the leaf inoculation method. The highest resistance levels were observed in tomato genotypes AF 11768, AF 2521, AF 11766, AF 11772, AF 229, AF 5719-1, and AF 8162. The genotype AF 5719-1, wich has the Pto gene imparting resistance to P. syringae pv. tomato, showed a good level of resistance to P. cichorii. The identification of genotypes with good levels of resistance to this pathogen is important, since they represent potential resources to be used in tomato breeding programs for incorporation of resistance genes against P. cichorii.

  5. Scientific communications: Re-Os sulfide (bornite, chalcopyrite, and pyrite) systematics of the carbonate-hosted copper deposits at ruby creek, southern brooks range, Alaska

    Science.gov (United States)

    Selby, D.; Kelley, K.D.; Hitzman, M.W.; Zieg, J.

    2009-01-01

    New Re-Os data for chalcopyrite, bornite, and pyrite from the carbonate-hosted Cu deposit at Ruby Creek (Bornite), Alaska, show extremely high Re abundances (hundreds of ppb, low ppm) and contain essentially no common Os. The Re-Os data provide the first absolute ages of ore formation for the carbonate-hosted Ruby Creek Cu-(Co) deposit and demonstrate that the Re-Os systematics of pyrite, chalcopyrite, and bornite are unaffected by greenschist metamorphism. The Re-Os data show that the main phase of Cu mineralization pre dominantly occurred at 384 ?? 4.2 Ma, with an earlier phase possibly at ???400 Ma. The Re-Os data are consistent with the observed paragenetic sequence and coincide with zircon U-Pb ages from igneous rocks within the Ambler metallogenic belt, some of which are spatially and genetically associated with regional volcanogenic massive sulfide deposits. The latter may suggest a temporal link between regional magmatism and hydrothermal mineralization in the Ambler district. The utility of bornite and chalcopyrite, in addition to pyrite, contributes to a new understanding of Re-Os geochronology and permits a refinement of the genetic model for the Ruby Creek deposit. ?? 2009 Society of Economices Geologists, Inc.

  6. Parasite assemblages in fish hosts | Iyaji | Bio-Research

    African Journals Online (AJOL)

    A review of various factors affecting parasite assemblages in fish hosts is presented. These factors are broadly divided into two: Biotic and abiotic factors. Biotic factors such as host age and size, host size and parasites size, host specificity, host diet and host sex and their influence on the abundance and distribution of ...

  7. Zig-zagging across Central Europe: recent range extension, dispersal speed and larval hosts of Aproceros leucopoda (Hymenoptera, Argidae in Germany

    Directory of Open Access Journals (Sweden)

    Stephan M. Blank

    2014-12-01

    Full Text Available Aproceros leucopoda, the zig-zag sawfly, an invasive pest of elms (Ulmus spp., was found in two separate areas of Germany through July 2014, i.e., a northern area including the states of Berlin, Brandenburg, Mecklenburg-West Pomerania, Saxony and Saxony-Anhalt, and a southern area in Bavaria. A speed of self-dispersal of 45–90 km/yr has been calculated from earlier and present records. Observations of A. leucopoda in Belgium and the Netherlands during 2013, which are 360–610 km distant from records in Germany of that year, are interpreted as resulting from human-mediated jump dispersal. Larvae, feeding traces and cocoons were frequently found on the native elm species U. minor and U. glabra, whereas none could be detected on U. laevis. Other occurrences were often on Resista® elms, causing severe defoliation in a recent planting. New host plant records for A. leucopoda are: U. minor ‘Webbiana’, U. minor var. suberosa, and the Resista® cultivars U. ‘New Horizon’, U. ‘Regal’ and U. ‘Rebona’. The future dispersal of A. leucopoda throughout most of Germany is expected, because at least U. glabra and U. minor are widespread in this country.

  8. Infections of nervous necrosis virus in wild and cage-reared marine fish from South China Sea with unexpected wide host ranges.

    Science.gov (United States)

    Liu, X D; Huang, J N; Weng, S P; Hu, X Q; Chen, W J; Qin, Z D; Dong, X X; Liu, X L; Zhou, Y; Asim, M; Wang, W M; He, J G; Lin, L

    2015-06-01

    The concerns about the impact of the nervous necrosis virus (NNV) infections in wild fish have been raised. This paper presents the results of quarterly surveys of NNV in wild and cage-reared marine fish from South China Sea. Samples of 892 wild fish belonging to 69 species and 381 cage-reared fish belonging to 11 species were collected and were detected by seminested PCR and nested PCR. In the case of seminested PCR, the positive signal was detected in 3.0% and 3.1% samples of wild and cage-reared fish, respectively. However, by nested RT-PCR, the positive signal was observed in 42.3% and 63.0% samples of wild and cage-reared fish, respectively. If the fish species were considered, the positive signal was detected in 21.7% and 72.7% species of wild and cage-reared fish by seminested PCR assay, respectively. However, by nested RT-PCR, the positive signal was observed in 65.2% and 100% species of wild and cage-reared fish, respectively. The nucleotide sequences of the nested PCR products were determined. Phylogenetic tree showed that all the obtained viral isolates belonged to the red-spotted grouper nervous necrosis virus (RGNNV) genotype. Thirty-five species of the marine fish were the new hosts of NNV. © 2014 John Wiley & Sons Ltd.

  9. Using Ecology, Physiology, and Genomics to Understand Host Specificity in Xanthomonas.

    Science.gov (United States)

    Jacques, Marie-Agnès; Arlat, Matthieu; Boulanger, Alice; Boureau, Tristan; Carrère, Sébastien; Cesbron, Sophie; Chen, Nicolas W G; Cociancich, Stéphane; Darrasse, Armelle; Denancé, Nicolas; Fischer-Le Saux, Marion; Gagnevin, Lionel; Koebnik, Ralf; Lauber, Emmanuelle; Noël, Laurent D; Pieretti, Isabelle; Portier, Perrine; Pruvost, Olivier; Rieux, Adrien; Robène, Isabelle; Royer, Monique; Szurek, Boris; Verdier, Valérie; Vernière, Christian

    2016-08-04

    How pathogens coevolve with and adapt to their hosts are critical to understanding how host jumps and/or acquisition of novel traits can lead to new disease emergences. The Xanthomonas genus includes Gram-negative plant-pathogenic bacteria that collectively infect a broad range of crops and wild plant species. However, individual Xanthomonas strains usually cause disease on only a few plant species and are highly adapted to their hosts, making them pertinent models to study host specificity. This review summarizes our current understanding of the molecular basis of host specificity in the Xanthomonas genus, with a particular focus on the ecology, physiology, and pathogenicity of the bacterium. Despite our limited understanding of the basis of host specificity, type III effectors, microbe-associated molecular patterns, lipopolysaccharides, transcriptional regulators, and chemotactic sensors emerge as key determinants for shaping host specificity.

  10. Association and host selectivity in multi-host pathogens.

    Directory of Open Access Journals (Sweden)

    José M Malpica

    2006-12-01

    Full Text Available The distribution of multi-host pathogens over their host range conditions their population dynamics and structure. Also, host co-infection by different pathogens may have important consequences for the evolution of hosts and pathogens, and host-pathogen co-evolution. Hence it is of interest to know if the distribution of pathogens over their host range is random, or if there are associations between hosts and pathogens, or between pathogens sharing a host. To analyse these issues we propose indices for the observed patterns of host infection by pathogens, and for the observed patterns of co-infection, and tests to analyse if these patterns conform to randomness or reflect associations. Applying these tests to the prevalence of five plant viruses on 21 wild plant species evidenced host-virus associations: most hosts and viruses were selective for viruses and hosts, respectively. Interestingly, the more host-selective viruses were the more prevalent ones, suggesting that host specialisation is a successful strategy for multi-host pathogens. Analyses also showed that viruses tended to associate positively in co-infected hosts. The developed indices and tests provide the tools to analyse how strong and common are these associations among different groups of pathogens, which will help to understand and model the population biology of multi-host pathogens.

  11. Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

    Science.gov (United States)

    Ng, Terry Fei Fan; Willner, Dana L.; Lim, Yan Wei; Schmieder, Robert; Chau, Betty; Nilsson, Christina; Anthony, Simon; Ruan, Yijun; Rohwer, Forest; Breitbart, Mya

    2011-01-01

    Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes. PMID:21674005

  12. African Journals Online: General Science (broad subject range)

    African Journals Online (AJOL)

    Items 1 - 50 of 86 ... Afrique Science publishes experimental, theoretical and applied results in mathematics, physics, chemistry, biology, geology and engineering. .... involving technology for recording and/or analysing humans at work, observational reports from the field, brief research reports/updates, and news and views.

  13. African Journals Online: General Science (broad subject range)

    African Journals Online (AJOL)

    Items 51 - 86 of 86 ... Maritime education and training; Maritime technology; Maritime administration; Maritime environmental and ocean management; Port and shipping administration; Maritime transport and logistics; Maritime policy and practices; Maritime safety and security; Engineering; Information Communication ...

  14. Efficient Space Hardy Thermoelectric Materials with Broad Temperature Range Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this work is to develop new thermoelectric materials for use in fabricating solid state cooling devices and electrical power generators, which are 200 to...

  15. Environmentally stable picosecond fibre laser with broad tuning range

    OpenAIRE

    Traynor, N.J.; Chen, Z. J.; de Porta, J.; Minelly, J. D.; Grudinin, A. B.

    1997-01-01

    We demonstrate a robust, mode-locked, tunable Yb doped fibre laser. The use of dual mode-locked and Q-switched operation in a passively mode-locked configuration allows us to generate 5 ps pulses with a peak power of 750 W at a repetition rate of 100 MHz

  16. African Journals Online: General Science (broad subject range)

    African Journals Online (AJOL)

    Items 51 - 86 of 86 ... MEJSis a peer reviewed half yearly, international, interdisciplinary and free access electronic journal. The scope of the journal includes various aspects of natural and computational sciences in general and geology, chemistry, physics, biology and mathematical sciences in particular. It focuses on both ...

  17. Efficient Space Hardy Thermoelectric Materials with Broad Temperature Range Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this work is developing new thermoelectric materials for use in fabricating solid state cooling devices and electrical power generators, which are 200 to...

  18. Optical fiber voltage sensors for broad temperature ranges

    Science.gov (United States)

    Rose, A. H.; Day, G. W.

    1992-01-01

    We describe the development of an optical fiber ac voltage sensor for aircraft and spacecraft applications. Among the most difficult specifications to meet for this application is a temperature stability of +/- 1 percent from -65 C to +125 C. This stability requires a careful selection of materials, components, and optical configuration with further compensation using an optical-fiber temperature sensor located near the sensing element. The sensor is a polarimetric design, based on the linear electro-optic effect in bulk Bi4Ge3O12. The temperature sensor is also polarimetric, based on the temperature dependence of the birefringence of bulk SiO2. The temperature sensor output is used to automatically adjust the calibration of the instrument.

  19. Increased fuel standards among broad range of energy options

    Science.gov (United States)

    Showstack, Randy

    During simpler times, the mention of the word 'cafe' might have primarily conjured up images of sidewalk coffee and tea bars along Paris' Champs-Elysees. However, with today's concerns about energy needs, CAFE or Corporate Average Fuel Economy standards for automobile fuel efficiency is a hot topic.On August 2, the U.S. House of Representa tives passed an energy bill rejecting a proposal to substantially increase CAFE standards for increasingly popular sport utility vehicles (SUVs). The proposal, which would have required SUVs to increase their current fleet average of 20.5 miles per gallon (mpg) to 27.5 mpg by 2007, to equal the current passenger car fleet requirement, was shelved for a requirement to more modestly raise mpgs by cutting total SUV gasoline usage by 5 billion gallons over 6 years.

  20. A Proposal for a Genome Similarity-Based Taxonomy for Plant-Pathogenic Bacteria that Is Sufficiently Precise to Reflect Phylogeny, Host Range, and Outbreak Affiliation Applied to Pseudomonas syringae sensu lato as a Proof of Concept.

    Science.gov (United States)

    Vinatzer, Boris A; Weisberg, Alexandra J; Monteil, Caroline L; Elmarakeby, Haitham A; Sheppard, Samuel K; Heath, Lenwood S

    2017-01-01

    Taxonomy of plant pathogenic bacteria is challenging because pathogens of different crops often belong to the same named species but current taxonomy does not provide names for bacteria below the subspecies level. The introduction of the host range-based pathovar system in the 1980s provided a temporary solution to this problem but has many limitations. The affordability of genome sequencing now provides the opportunity for developing a new genome-based taxonomic framework. We already proposed to name individual bacterial isolates based on pairwise genome similarity. Here, we expand on this idea and propose to use genome similarity-based codes, which we now call life identification numbers (LINs), to describe and name bacterial taxa. Using 93 genomes of Pseudomonas syringae sensu lato, LINs were compared with a P. syringae genome tree whereby the assigned LINs were found to be informative of a majority of phylogenetic relationships. LINs also reflected host range and outbreak association for strains of P. syringae pathovar actinidiae, a pathovar for which many genome sequences are available. We conclude that LINs could provide the basis for a new taxonomic framework to address the shortcomings of the current pathovar system and to complement the current taxonomic system of bacteria in general.

  1. Broad spectrum antibiotic compounds and use thereof

    Energy Technology Data Exchange (ETDEWEB)

    Koglin, Alexander; Strieker, Matthias

    2016-07-05

    The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

  2. Lack of adaptation to a new host in a generalist herbivore: implications for host plant resistance to twospotted spider mites in cotton.

    Science.gov (United States)

    Miyazaki, Junji; Wilson, Lewis J; Stiller, Warwick N

    2015-04-01

    The twospotted spider mite (Tetranychus urticae Koch) is an important pest of cotton. This pest has a broad host range, but when changing between hosts an initial decline in fitness often occurs. This is usually followed by an increase in fitness after rapid adaptation to the new host, usually within five generations. The generality of this adaptive response was tested by assessing elements of fitness when mites were reared on a host to which they were adapted (Gossypium hirsutum L. cv. Sicot 71) or on a new host, Gossypium arboreum L. (accession BM13H). In a first experiment, mites reared on the new host for ten generations showed declining immature survival compared with those reared on the adapted host. In a second experiment, the intrinsic capacity for increase of mites cultured on the new host for six generations was significantly lower than that of mites cultured on the adapted host for six generations and then transferred to the new host. Hence, exposure to the new host for six or ten generations resulted in declining fitness. This 'negative adaptation' indicates robust antibiosis traits in G. arboreum accession BM13H, which therefore have value in developing mite-resistant G. hirsutum cultivars. © 2014 Society of Chemical Industry.

  3. Niclosamide is a proton carrier and targets acidic endosomes with broad antiviral effects.

    Directory of Open Access Journals (Sweden)

    Andreas Jurgeit

    Full Text Available Viruses use a limited set of host pathways for infection. These pathways represent bona fide antiviral targets with low likelihood of viral resistance. We identified the salicylanilide niclosamide as a broad range antiviral agent targeting acidified endosomes. Niclosamide is approved for human use against helminthic infections, and has anti-neoplastic and antiviral effects. Its mode of action is unknown. Here, we show that niclosamide, which is a weak lipophilic acid inhibited infection with pH-dependent human rhinoviruses (HRV and influenza virus. Structure-activity studies showed that antiviral efficacy and endolysosomal pH neutralization co-tracked, and acidification of the extracellular medium bypassed the virus entry block. Niclosamide did not affect the vacuolar H(+-ATPase, but neutralized coated vesicles or synthetic liposomes, indicating a proton carrier mode-of-action independent of any protein target. This report demonstrates that physico-chemical interference with host pathways has broad range antiviral effects, and provides a proof of concept for the development of host-directed antivirals.

  4. Identification of Restriction Factors by Human Genome-Wide RNA Interference Screening of Viral Host Range Mutants Exemplified by Discovery of SAMD9 and WDR6 as Inhibitors of the Vaccinia Virus K1L−C7L− Mutant

    Science.gov (United States)

    Sivan, Gilad; Ormanoglu, Pinar; Buehler, Eugen C.; Martin, Scott E.

    2015-01-01

    ABSTRACT RNA interference (RNAi) screens intended to identify host factors that restrict virus replication may fail if the virus already counteracts host defense mechanisms. To overcome this limitation, we are investigating the use of viral host range mutants that exhibit impaired replication in nonpermissive cells. A vaccinia virus (VACV) mutant with a deletion of both the C7L and K1L genes, K1L−C7L−, which abrogates replication in human cells at a step prior to late gene expression, was chosen for this strategy. We carried out a human genome-wide small interfering RNA (siRNA) screen in HeLa cells infected with a VACV K1L−C7L− mutant that expresses the green fluorescent protein regulated by a late promoter. This positive-selection screen had remarkably low background levels and resulted in the identification of a few cellular genes, notably SAMD9 and WDR6, from approximately 20,000 tested that dramatically enhanced green fluorescent protein expression. Replication of the mutant virus was enabled by multiple siRNAs to SAMD9 or WDR6. Moreover, SAMD9 and WDR6 clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 knockout HeLa cell lines were permissive for replication of the K1L−C7L− mutant, in agreement with the siRNA data. Expression of exogenous SAMD9 or interferon regulatory factor 1 restricted replication of the K1L−C7L− mutant in the SAMD9−/− cells. Independent interactions of SAMD9 with the K1 and C7 proteins were suggested by immunoprecipitation. Knockout of WDR6 did not reduce the levels of SAMD9 and interactions of WDR6 with SAMD9, C7, and K1 proteins were not detected, suggesting that these restriction factors act independently but possibly in the same innate defense pathway. PMID:26242627

  5. Diagnostic utility of broad range bacterial 16S rRNA gene PCR with degradation of human and free bacterial DNA in bloodstream infection is more sensitive than an in-house developed PCR without degradation of human and free bacterial DNA.

    Science.gov (United States)

    Rogina, Petra; Skvarc, Miha; Stubljar, David; Kofol, Romina; Kaasch, Achim

    2014-01-01

    We compared a commercial broad range 16S rRNA gene PCR assay (SepsiTest) to an in-house developed assay (IHP). We assessed whether CD64 index, a biomarker of bacterial infection, can be used to exclude patients with a low probability of systemic bacterial infection. From January to March 2010, 23 patients with suspected sepsis were enrolled. CD64 index, procalcitonin, and C-reactive protein were measured on admission. Broad range 16S rRNA gene PCR was performed from whole blood (SepsiTest) or blood plasma (IHP) and compared to blood culture results. Blood samples spiked with Staphylococcus aureus were used to assess sensitivity of the molecular assays in vitro. CD64 index was lower in patients where possible sepsis was excluded than in patients with microbiologically confirmed sepsis (P = 0.004). SepsiTest identified more relevant pathogens than blood cultures (P = 0.008); in three patients (13%) results from blood culture and SepsiTest were congruent, whereas in four cases (17.4%) relevant pathogens were detected by SepsiTest only. In vitro spiking experiments suggested equal sensitivity of SepsiTest and IHP. A diagnostic algorithm using CD64 index as a decision maker to perform SepsiTest shows improved detection of pathogens in patients with suspected blood stream infection and may enable earlier targeted antibiotic therapy.

  6. Diagnostic Utility of Broad Range Bacterial 16S rRNA Gene PCR with Degradation of Human and Free Bacterial DNA in Bloodstream Infection Is More Sensitive Than an In-House Developed PCR without Degradation of Human and Free Bacterial DNA

    Directory of Open Access Journals (Sweden)

    Petra Rogina

    2014-01-01

    Full Text Available We compared a commercial broad range 16S rRNA gene PCR assay (SepsiTest to an in-house developed assay (IHP. We assessed whether CD64 index, a biomarker of bacterial infection, can be used to exclude patients with a low probability of systemic bacterial infection. From January to March 2010, 23 patients with suspected sepsis were enrolled. CD64 index, procalcitonin, and C-reactive protein were measured on admission. Broad range 16S rRNA gene PCR was performed from whole blood (SepsiTest or blood plasma (IHP and compared to blood culture results. Blood samples spiked with Staphylococcus aureus were used to assess sensitivity of the molecular assays in vitro. CD64 index was lower in patients where possible sepsis was excluded than in patients with microbiologically confirmed sepsis (P=0.004. SepsiTest identified more relevant pathogens than blood cultures (P=0.008; in three patients (13% results from blood culture and SepsiTest were congruent, whereas in four cases (17.4% relevant pathogens were detected by SepsiTest only. In vitro spiking experiments suggested equal sensitivity of SepsiTest and IHP. A diagnostic algorithm using CD64 index as a decision maker to perform SepsiTest shows improved detection of pathogens in patients with suspected blood stream infection and may enable earlier targeted antibiotic therapy.

  7. Host range, symbiotic effectiveness and nodulation competitiveness ...

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... soil nitrogen status which is a major threat to food production (Sanginga, 2003). Biological ... an important food legume that features prominently in many farming systems in Africa including Ghana (Fening ..... (2005). Role of trehalose transport and utilization in Sinorhizobium meliloti-alfalfa interactions. Mol.

  8. Molecular phylogeny based on mitochondrial genes and evolution of host plant use in the long-horned beetle tribe Lamiini (Coleoptera: Cerambycidae) in Japan.

    Science.gov (United States)

    Toki, W; Kubota, K

    2010-08-01

    The molecular phylogeny of the long-horned beetle tribe Lamiini Mulsant (Coleoptera: Cerambycidae) in Japan (12 genera, 25 species, 3 additional subspecies) was determined based on mitochondrial 16S rRNA and cytochrome oxydase subunit I. The monophyly of the tribe Lamiini was supported, whereas that of the genus Acalolepta Pascoe was unclear. Evolution of host plant use in Lamiini was estimated using the molecular phylogeny. For adult and larval host plant kind-and-condition, the most ancestral state was for weakened to dead broad-leaved trees, whereas derived states favored conifers, healthy broad-leaved trees, and herbs. For adult and larval host range, the most ancestral state was polyphagy, whereas oligophagy and monophagy were derived. Evolution of hosts' idiosyncrasy and that of the insects' host range were related in many lineages. Our results partly support the hypothesis that habitation in living trees requires dietary specialization in phytophagous insects.

  9. Range-wide Determinants of Plague Distribution in North America

    Science.gov (United States)

    Maher, Sean P.; Ellis, Christine; Gage, Kenneth L.; Enscore, Russell E.; Peterson, A. Townsend

    2010-01-01

    Plague, caused by the bacterium Yersinia pestis, is established across western North America, and yet little is known of what determines the broad-scale dimensions of its overall range. We tested whether its North American distribution represents a composite of individual host–plague associations (the “Host Niche Hypothesis”), or whether mammal hosts become infected only at sites overlapping ecological conditions appropriate for plague transmission and maintenance (the “Plague Niche Hypothesis”). We took advantage of a novel data set summarizing plague records in wild mammals newly digitized from paper-based records at the Centers for Disease Control and Prevention to develop range-wide tests of ecological niche similarity between mammal host niches and plague-infected host niches. Results indicate that plague infections occur under circumstances distinct from the broader ecological distribution of hosts, and that plague-infected niches are similar among hosts; hence, evidence coincides with the predictions of the Plague Niche Hypothesis, and contrasts with those of the Host Niche Hypothesis. The “plague niche” is likely driven by ecological requirements of vector flea species. PMID:20889857

  10. Host niches and defensive extended phenotypes structure parasitoid wasp communities.

    Directory of Open Access Journals (Sweden)

    Richard Bailey

    2009-08-01

    spatiotemporal traits on community structure can be high, reaching 62% in one analysis. The observed patterns derive mainly from partial niche specialisation of highly generalist parasitoids with broad host ranges (>20 hosts, rather than strict separation of enemies with narrower host ranges, and so may contribute to maintenance of the richness of generalist parasitoids in gallwasp communities. Though evolutionary escape from parasitoids might most effectively be achieved via changes in host oak taxon, extreme conservatism in this trait for gallwasps suggests that selection is more likely to have acted on gall morphology and location. Any escape from parasitoids associated with evolutionary shifts in these traits has probably only been transient, however, due to subsequent recruitment of parasitoid species already attacking other host galls with similar trait combinations.

  11. Recent range expansion of an intermediate host for animal schistosome parasites in the Indo-Australian Archipelago: phylogeography of the freshwater gastropod Indoplanorbis exustus in South and Southeast Asia.

    Science.gov (United States)

    Gauffre-Autelin, Pauline; von Rintelen, Thomas; Stelbrink, Björn; Albrecht, Christian

    2017-03-06

    The planorbid snail Indoplanorbis exustus is the sole intermediate host for the Schistosoma indicum species group, trematode parasites responsible for cattle schistosomiasis and human cercarial dermatitis. This freshwater snail is widely distributed in Southern Asia, ranging from Iran to China eastwards including India and from the southeastern Himalayas to Southeast Asia southwards. The veterinary and medical importance of this snail explains the interest in understanding its geographical distribution patterns and evolutionary history. In this study, we used a large and comprehensive sampling throughout Indo-Malaya, including specimens from South India and Indonesia, areas that have been formerly less studied. The phylogenetic inference revealed five highly divergent clades (genetic distances among clades: 4.4-13.9%) that are morphologically indistinguishable, supporting the assumption that this presumed nominal species may represent a cryptic species complex. The species group may have originated in the humid subtropical plains of Nepal or in southern adjacent regions in the Early Miocene. The major cladogenetic events leading to the fives clades occurred successively from the Early Miocene to the Early Pleistocene, coinciding with major periods of monsoonal intensification associated with major regional paleogeographic events in the Miocene and repeated climate changes due to the Plio-Pleistocene climatic oscillations. Our coverage of the Indo-Australian Archipelago (IAA) highlights the presence of a single clade there. Contrary to expectations, an AMOVA did not reveal any population genetic structure among islands or along a widely recognised zoogeographical regional barrier, suggesting a recent colonisation independent of natural biogeographical constraints. Neutrality tests and mismatch distributions suggested a sudden demographic and spatial population expansion that could have occurred naturally in the Pleistocene or may possibly result of a modern

  12. Broad-band semiconductor optical amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ding Ying [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)]. E-mail: yingding@red.semi.ac.cn; Kan Qiang [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Wang Junling [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Pan Jiaoqing [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Zhou Fan [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Chen Weixi [School of Physics, Peking University, Beijing 100871 (China); Wang Wei [Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2007-01-15

    Broad-band semiconductor optical amplifiers (SOAs) with different thicknesses and thin bulk tensile-strained active layers were fabricated and studied. Amplified spontaneous emission (ASE) spectra and gain spectra of SOAs were measured and analyzed at different CW biases. A maximal 3 dB ASE bandwidth of 136 nm ranging from 1480 to 1616 nm, and a 3 dB optical amplifier gain bandwidth of about 90 nm ranging from 1510 to 1600 nm, were obtained for the very thin bulk active SOA. Other SOAs characteristics such as saturation output power and polarization sensitivity were measured and compared.

  13. Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

    Directory of Open Access Journals (Sweden)

    Avi Raveh

    Full Text Available Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable

  14. Discovery of potent broad spectrum antivirals derived from marine actinobacteria.

    Science.gov (United States)

    Raveh, Avi; Delekta, Phillip C; Dobry, Craig J; Peng, Weiping; Schultz, Pamela J; Blakely, Pennelope K; Tai, Andrew W; Matainaho, Teatulohi; Irani, David N; Sherman, David H; Miller, David J

    2013-01-01

    Natural products provide a vast array of chemical structures to explore in the discovery of new medicines. Although secondary metabolites produced by microbes have been developed to treat a variety of diseases, including bacterial and fungal infections, to date there has been limited investigation of natural products with antiviral activity. In this report, we used a phenotypic cell-based replicon assay coupled with an iterative biochemical fractionation process to identify, purify, and characterize antiviral compounds produced by marine microbes. We isolated a compound from Streptomyces kaviengensis, a novel actinomycetes isolated from marine sediments obtained off the coast of New Ireland, Papua New Guinea, which we identified as antimycin A1a. This compound displays potent activity against western equine encephalitis virus in cultured cells with half-maximal inhibitory concentrations of less than 4 nM and a selectivity index of greater than 550. Our efforts also revealed that several antimycin A analogues display antiviral activity, and mechanism of action studies confirmed that these Streptomyces-derived secondary metabolites function by inhibiting the cellular mitochondrial electron transport chain, thereby suppressing de novo pyrimidine synthesis. Furthermore, we found that antimycin A functions as a broad spectrum agent with activity against a wide range of RNA viruses in cultured cells, including members of the Togaviridae, Flaviviridae, Bunyaviridae, Picornaviridae, and Paramyxoviridae families. Finally, we demonstrate that antimycin A reduces central nervous system viral titers, improves clinical disease severity, and enhances survival in mice given a lethal challenge with western equine encephalitis virus. Our results provide conclusive validation for using natural product resources derived from marine microbes as source material for antiviral drug discovery, and they indicate that host mitochondrial electron transport is a viable target for the

  15. The predictability of phytophagous insect communities: host specialists as habitat specialists.

    Directory of Open Access Journals (Sweden)

    Jörg Müller

    Full Text Available The difficulties specialized phytophagous insects face in finding habitats with an appropriate host should constrain their dispersal. Within the concept of metacommunities, this leads to the prediction that host-plant specialists should sort into local assemblages according to the local environmental conditions, i.e. habitat conditions, whereas assemblages of host-plant generalists should depend also on regional processes. Our study aimed at ranking the importance of local environmental factors and species composition of the vegetation for predicting the species composition of phytophagous moth assemblages with either a narrow or a broad host range. Our database consists of 351,506 specimens representing 820 species of nocturnal Macrolepidoptera sampled between 1980 and 2006 using light traps in 96 strict forest reserves in southern Germany. Species were grouped as specialists or generalists according to the food plants of the larvae; specialists use host plants belonging to one genus. We used predictive canonical correspondence and co-correspondence analyses to rank the importance of local environmental factors, the species composition of the vegetation and the role of host plants for predicting the species composition of host-plant specialists and generalists. The cross-validatory fit for predicting the species composition of phytophagous moths was higher for host-plant specialists than for host-plant generalists using environmental factors as well as the composition of the vegetation. As expected for host-plant specialists, the species composition of the vegetation was a better predictor of the composition of these assemblages than the environmental variables. But surprisingly, this difference for specialized insects was not due to the occurrence of their host plants. Overall, our study supports the idea that owing to evolutionary constraints in finding a host, host-plant specialists and host-plant generalists follow two different models of

  16. The Broad Superintendents Academy, 2007

    Science.gov (United States)

    Broad Foundation, 2007

    2007-01-01

    The Broad Superintendents Academy is an executive training program that identifies and prepares prominent leaders--executives with experience successfully leading large organizations and a passion for public service--then places them in urban school districts to dramatically improve the quality of education for America's students. This brochure…

  17. Parallel evaluation of broad virus detection methods.

    Science.gov (United States)

    Modrof, Jens; Berting, Andreas; Kreil, Thomas R

    2014-01-01

    The testing for adventitious viruses is of critical importance during development and production of biological products. The recent emergence and ongoing development of broad virus detection methods calls for an evaluation of whether these methods can appropriately be implemented into current adventitious agent testing procedures. To assess the suitability of several broad virus detection methods, a comparative experimental study was conducted: four virus preparations, which were spiked at two different concentrations each into two different cell culture media, were sent to four investigators in a blinded fashion for analysis with broad virus detection methods such as polymerase chain reaction-electrospray ionization mass spectrometry (PCR-ESI/MS), microarray, and two approaches utilizing massively parallel sequencing. The results that were reported by the investigators revealed that all methods were able to identify the majority of samples correctly (mean 83%), with a surprisingly narrow range among the methods, that is, between 72% (PCR-ESI/MS) and 95% (microarray). In addition to the correct results, a variety of unexpected assignments were reported for a minority of samples, again with little variation regarding the methods used (range 20-45%), while false negatives were reported for 0-25% of the samples. Regarding assay sensitivity, the viruses were detected by all methods included in this study at concentrations of about 4-5 log10 quantitative PCR copies/mL, and probably with higher sensitivity in some cases. In summary, the broad virus detection methods investigated were shown to be suitable even for detection of relatively low virus concentrations. However, there is also some potential for the production of false-positive as well as false-negative assignments, which indicates the requirement for further improvements before these methods can be considered for routine use. © PDA, Inc. 2014.

  18. Diversifying selection and host adaptation in two endosymbiont genomes

    Directory of Open Access Journals (Sweden)

    Slatko Barton

    2007-04-01

    Full Text Available Abstract Background The endosymbiont Wolbachia pipientis infects a broad range of arthropod and filarial nematode hosts. These diverse associations form an attractive model for understanding host:symbiont coevolution. Wolbachia's ubiquity and ability to dramatically alter host reproductive biology also form the foundation of research strategies aimed at controlling insect pests and vector-borne disease. The Wolbachia strains that infect nematodes are phylogenetically distinct, strictly vertically transmitted, and required by their hosts for growth and reproduction. Insects in contrast form more fluid associations with Wolbachia. In these taxa, host populations are most often polymorphic for infection, horizontal transmission occurs between distantly related hosts, and direct fitness effects on hosts are mild. Despite extensive interest in the Wolbachia system for many years, relatively little is known about the molecular mechanisms that mediate its varied interactions with different hosts. We have compared the genomes of the Wolbachia that infect Drosophila melanogaster, wMel and the nematode Brugia malayi, wBm to that of an outgroup Anaplasma marginale to identify genes that have experienced diversifying selection in the Wolbachia lineages. The goal of the study was to identify likely molecular mechanisms of the symbiosis and to understand the nature of the diverse association across different hosts. Results The prevalence of selection was far greater in wMel than wBm. Genes contributing to DNA metabolism, cofactor biosynthesis, and secretion were positively selected in both lineages. In wMel there was a greater emphasis on DNA repair, cell division, protein stability, and cell envelope synthesis. Conclusion Secretion pathways and outer surface protein encoding genes are highly affected by selection in keeping with host:parasite theory. If evidence of selection on various cofactor molecules reflects possible provisioning, then both insect as

  19. Apprenticeships at CERN: a host of awards

    CERN Multimedia

    2009-01-01

    This year again, two CERN apprentices have received awards at the end of their training. CERN’s broad range of technical skills means that it can provide training in a wide variety of trades and professions. Denis Fernier receives congratulations from Pierre-François Unger, Counsel state of the canton of Geneva in charge of the department of economics and health. Denis Fernier and Coralie Husi (right) at the prize-giving ceremony of the Union Industrielle de Genève.Every year, CERN hosts six technical apprentices for a four-year period: three electronics technicians and three physics lab technicians. And every year, at the end of their apprenticeships, one or more of them receives an award for being among the best apprentices in Geneva. On 23 September, two young apprentices were honoured by the Union industrielle genevoise (UIG) on passing their exams: Coralie Husi, a physics lab apprentice...

  20. Molecular Markers, MAT and Modeling: New Evidence for Leptospirosis Being Endemic in California Sea Lions, with Periodic Epizootics that Defy the Host-adapted Strain Paradigm

    Science.gov (United States)

    Leptospirosis is a zoonotic disease infecting a broad range of mammalian hosts, and is re-emerging globally in humans and domestic dogs. Disease outbreaks have occurred periodically in California sea lions (Zalophus californianus) off the central and northern coasts of California, with hundreds of a...

  1. Two New Complete Genome Sequences Offer Insight into Host and Tissue Specificity of Plant Pathogenic Xanthomonas spp.▿†

    Science.gov (United States)

    Bogdanove, Adam J.; Koebnik, Ralf; Lu, Hong; Furutani, Ayako; Angiuoli, Samuel V.; Patil, Prabhu B.; Van Sluys, Marie-Anne; Ryan, Robert P.; Meyer, Damien F.; Han, Sang-Wook; Aparna, Gudlur; Rajaram, Misha; Delcher, Arthur L.; Phillippy, Adam M.; Puiu, Daniela; Schatz, Michael C.; Shumway, Martin; Sommer, Daniel D.; Trapnell, Cole; Benahmed, Faiza; Dimitrov, George; Madupu, Ramana; Radune, Diana; Sullivan, Steven; Jha, Gopaljee; Ishihara, Hiromichi; Lee, Sang-Won; Pandey, Alok; Sharma, Vikas; Sriariyanun, Malinee; Szurek, Boris; Vera-Cruz, Casiana M.; Dorman, Karin S.; Ronald, Pamela C.; Verdier, Valérie; Dow, J. Maxwell; Sonti, Ramesh V.; Tsuge, Seiji; Brendel, Volker P.; Rabinowicz, Pablo D.; Leach, Jan E.; White, Frank F.; Salzberg, Steven L.

    2011-01-01

    Xanthomonas is a large genus of bacteria that collectively cause disease on more than 300 plant species. The broad host range of the genus contrasts with stringent host and tissue specificity for individual species and pathovars. Whole-genome sequences of Xanthomonas campestris pv. raphani strain 756C and X. oryzae pv. oryzicola strain BLS256, pathogens that infect the mesophyll tissue of the leading models for plant biology, Arabidopsis thaliana and rice, respectively, were determined and provided insight into the genetic determinants of host and tissue specificity. Comparisons were made with genomes of closely related strains that infect the vascular tissue of the same hosts and across a larger collection of complete Xanthomonas genomes. The results suggest a model in which complex sets of adaptations at the level of gene content account for host specificity and subtler adaptations at the level of amino acid or noncoding regulatory nucleotide sequence determine tissue specificity. PMID:21784931

  2. Effect of host tree species on cellulase activity and bacterial community composition in the gut of larval Asian longhorned beetle.

    Science.gov (United States)

    Geib, Scott M; Jimenez-Gasco, Maria Del Mar; Carlson, John E; Tien, Ming; Hoover, Kelli

    2009-06-01

    Anoplophora glabripennis, the Asian longhorned beetle, is a wood-boring insect that can develop in a wide range of healthy deciduous hosts and requires gut microbes to aid in wood degradation and digestion. Here we show that larval A. glabripennis harbor a diverse gut bacterial community, and this community can be extremely variable when reared in different host trees. A. glabripennis reared in a preferred host (Acer saccharum) had the highest gut bacterial diversity compared with larvae reared either in a secondary host (Quercus palustris), a resistant host (Pyrus calleryana), or on artificial diet. The gut microbial community of larval A. glabripennis collected from field populations on Brooklyn, NY, showed the highest degree of complexity among all samples in this study. Overall, when larvae fed on a preferred host, they harbored a broad diversity of gut bacteria spanning the alpha-, beta-, gamma-Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Cellulase activities (beta-1,4-endoglucanase, beta-1,4-exoglucanase, and beta-1,4-glucosidase) in the guts of larvae fed in a preferred host (A. saccharum) or a secondary host (Q. palustris) were significantly higher than that of artificial diet fed larvae. Larvae that fed on wood from a resistant host (P. calleryana) showed suppressed total gut cellulase activity. Results show that the host tree can impact both gut microbial community complexity and cellulase activity in A. glabripennis.

  3. Comparative host-parasite population genetic structures: obligate fly ectoparasites on Galapagos seabirds.

    Science.gov (United States)

    Levin, Iris I; Parker, Patricia G

    2013-08-01

    Parasites often have shorter generation times and, in some cases, faster mutation rates than their hosts, which can lead to greater population differentiation in the parasite relative to the host. Here we present a population genetic study of two ectoparasitic flies, Olfersia spinifera and Olfersia aenescens compared with their respective bird hosts, great frigatebirds (Fregata minor) and Nazca boobies (Sula granti). Olfersia spinifera is the vector of a haemosporidian parasite, Haemoproteus iwa, which infects frigatebirds throughout their range. Interestingly, there is no genetic differentiation in the haemosporidian parasite across this range despite strong genetic differentiation between Galapagos frigatebirds and their non-Galapagos conspecifics. It is possible that the broad distribution of this one H. iwa lineage could be facilitated by movement of infected O. spinifera. Therefore, we predicted more gene flow in both fly species compared with the bird hosts. Mitochondrial DNA sequence data from three genes per species indicated that despite marked differences in the genetic structure of the bird hosts, gene flow was very high in both fly species. A likely explanation involves non-breeding movements of hosts, including movement of juveniles, and movement by adult birds whose breeding attempt has failed, although we cannot rule out the possibility that closely related host species may be involved.

  4. Genomes of three facultatively symbiotic Frankia sp. strainsreflect host plant biogeography

    Energy Technology Data Exchange (ETDEWEB)

    Normand, Philippe; Lapierre, Pascal; Tisa, Louis S.; Gogarten, J.Peter; Alloisio, Nicole; Bagnarol, Emilie; Bassi, Carla A.; Berry,Alison; Bickhart, Derek M.; Choisne, Nathalie; Couloux, Arnaud; Cournoyer, Benoit; Cruveiller, Stephane; Daubin, Vincent; Demange, Nadia; Francino, M. Pilar; Ggoltsman, Eugene; Huang, Ying; Kopp, Olga; Labarre,Laurent; Lapidus, Alla; Lavire, Celine; Marechal, Joelle; Martinez,Michele; Mastronunzio, Juliana E.; Mullin, Beth; Niemann, James; Pujic,Pierre; Rawnsley, Tania; Rouy, Zoe; Schenowitz, Chantal; Sellstedt,Anita; Tavares, Fernando; Tomkins, Jeffrey P.; Vallenet, David; Valverde,Claudio; Wall, Luis; Wang, Ying; Medigue, Claudine; Benson, David R.

    2006-02-01

    Filamentous actinobacteria from the genus Frankia anddiverse woody trees and shrubs together form N2-fixing actinorhizal rootnodule symbioses that are a major source of new soil nitrogen in widelydiverse biomes 1. Three major clades of Frankia sp. strains are defined;each clade is associated with a defined subset of plants from among theeight actinorhizal plant families 2,3. The evolution arytrajectoriesfollowed by the ancestors of both symbionts leading to current patternsof symbiont compatibility are unknown. Here we show that the competingprocesses of genome expansion and contraction have operated in differentgroups of Frankia strains in a manner that can be related to thespeciation of the plant hosts and their geographic distribution. Wesequenced and compared the genomes from three Frankia sp. strains havingdifferent host plant specificities. The sizes of their genomes variedfrom 5.38 Mbp for a narrow host range strain (HFPCcI3) to 7.50Mbp for amedium host range strain (ACN14a) to 9.08 Mbp for a broad host rangestrain (EAN1pec.) This size divergence is the largest yet reported forsuch closely related bacteria. Since the order of divergence of thestrains is known, the extent of gene deletion, duplication andacquisition could be estimated and was found to be inconcert with thebiogeographic history of the symbioses. Host plant isolation favoredgenome contraction, whereas host plant diversification favored genomeexpansion. The results support the idea that major genome reductions aswell as expansions can occur in facultatively symbiotic soil bacteria asthey respond to new environments in the context of theirsymbioses.

  5. Mode of transmission, host switching, and escape from the Red Queen by viviparous gyrodactylids (Monogenoidea).

    Science.gov (United States)

    Boeger, Walter A; Kritsky, Delane C; Pie, Marcio R; Engers, Kerlen B

    2005-10-01

    Compared to other monogenoidean groups, viviparous gyrodactylids exhibit extraordinary species diversity and broad host range. It has been suggested that this evolutionary success is associated with a suite of morphological and life-history traits that include, in part, continuous transmission (i.e., ability to infect new hosts throughout the gyrodactylid life cycle). Experiments were conducted to explore the putative adaptive advantage of continuous transmission within viviparous gyrodactylids during colonization of new host resources. Differences in infrapopulation growth, such as abundance, prevalence, and duration of the infection, of Gyrodactylus anisopharynx on 3 species of fish--Corydoras paleatus and Corydoras ehrhardti (both natural hosts) as well as Corydoras schwartzi (a host not known to harbor G. anisopharynx)--held under isolated and grouped conditions were determined. Results showed that infrapopulations of G. anisopharynx on C. paleatus and C. schwartzi had higher growth when the parasite had the opportunity for host transfer (grouped hosts). Infrapopulations of G. anisopharynx on isolated and grouped C. ehrhardti showed an opposite trend, although differences in mean duration and maximum abundance were not statistically different. Results obtained from experiments with C. paleatus and C. schwartzi support the hypothesis that continuous transmission in viviparous gyrodactylids enhances colonization success, probably by allowing initial avoidance of Red Queen dynamics. The absence of statistical differences between infrapopulations on isolated and grouped C. ehrhardti suggests that parasite dynamics may be influenced by factors other than continuous transmission in this host.

  6. Calcium Regulation of Hemorrhagic Fever Virus Budding: Mechanistic Implications for Host-Oriented Therapeutic Intervention.

    Directory of Open Access Journals (Sweden)

    Ziying Han

    2015-10-01

    Full Text Available Hemorrhagic fever viruses, including the filoviruses (Ebola and Marburg and arenaviruses (Lassa and Junín viruses, are serious human pathogens for which there are currently no FDA approved therapeutics or vaccines. Importantly, transmission of these viruses, and specifically late steps of budding, critically depend upon host cell machinery. Consequently, strategies which target these mechanisms represent potential targets for broad spectrum host oriented therapeutics. An important cellular signal implicated previously in EBOV budding is calcium. Indeed, host cell calcium signals are increasingly being recognized to play a role in steps of entry, replication, and transmission for a range of viruses, but if and how filoviruses and arenaviruses mobilize calcium and the precise stage of virus transmission regulated by calcium have not been defined. Here we demonstrate that expression of matrix proteins from both filoviruses and arenaviruses triggers an increase in host cytoplasmic Ca2+ concentration by a mechanism that requires host Orai1 channels. Furthermore, we demonstrate that Orai1 regulates both VLP and infectious filovirus and arenavirus production and spread. Notably, suppression of the protein that triggers Orai activation (Stromal Interaction Molecule 1, STIM1 and genetic inactivation or pharmacological blockade of Orai1 channels inhibits VLP and infectious virus egress. These findings are highly significant as they expand our understanding of host mechanisms that may broadly control enveloped RNA virus budding, and they establish Orai and STIM1 as novel targets for broad-spectrum host-oriented therapeutics to combat these emerging BSL-4 pathogens and potentially other enveloped RNA viruses that bud via similar mechanisms.

  7. Design of Metamaterial Surfaces with Broad-band Absorbance

    OpenAIRE

    Wu, Chihhui; Shvets, Gennady

    2011-01-01

    A simple design paradigm for making broad-band ultra-thin plasmonic absorbers is introduced. The absorber's unit cell is composed of sub-units of various sizes, resulting in nearly 100% absorbance at multiple adjacent frequencies and high absorbance over a broad frequency range. A simple theoretical model for designing broad-band absorbers is presented. It uses a single-resonance model to describe the optical response of each sub-unit and employs the series circuit model to predict the overal...

  8. Macroevolution of insect–plant associations: The relevance of host biogeography to host affiliation

    Science.gov (United States)

    Becerra, Judith X.; Venable, D. Lawrence

    1999-01-01

    Identifying the factors that have promoted host shifts by phytophagous insects at a macroevolutionary scale is critical to understanding the associations between plants and insects. We used molecular phylogenies of the beetle genus Blepharida and its host genus Bursera to test whether these insects have been using hosts with widely overlapping ranges over evolutionary time. We also quantified the importance of host range coincidence relative to host chemistry and host phylogenetic relatedness. Overall, the evolution of host use of these insects has not been among hosts that are geographically similar. Host chemistry is the factor that best explains their macroevolutionary patterns of host use. Interestingly, one exceptional polyphagous species has shifted among geographically close chemically dissimilar plants. PMID:10535973

  9. An extremely broad band metamaterial absorber based on destructive interference.

    Science.gov (United States)

    Sun, Jingbo; Liu, Lingyun; Dong, Guoyan; Zhou, Ji

    2011-10-24

    We propose a design of an extremely broad frequency band absorber based on destructive interference mechanism. Metamaterial of multilayered SRRs structure is used to realize a desirable refractive index dispersion spectrum, which can induce a successive anti-reflection in a wide frequency range. The corresponding high absorptance originates from the destructive interference of two reflection waves from the two surfaces of the metamaterial. A strongly absorptive bandwidth of almost 60 GHz is demonstrated in the range of 0 to 70 GHz numerically. This design provides an effective and feasible way to construct broad band absorber in stealth technology, as well as the enhanced transmittance devices. © 2011 Optical Society of America

  10. Feedback from Broad Absorption Line Quasars

    Science.gov (United States)

    Chartas, George; Saez, C.

    2008-03-01

    The fraction of the total bolometric energy released over an AGN's lifetime into the ISM and IGM in the form kinetic energy injection scales as the outflow velocity to the third power so we expect that powerful broad absorption line (BAL) quasars may have mass outflow rates that are large enough to influence significantly the formation of the host galaxy and to regulate the growth of the central black hole. One of the most promising radio quiet quasars for studying the properties of the outflow is the lensed BAL quasar APM 08279+5255. The large flux magnification by a factor of about 100 provided by the gravitational lens effect combined with the large redshift (z = 3.91) of the quasar have provided the highest S/N X-ray spectra of a quasar containing X-ray BALs. We present results from recent monitoring observations of APM 08279+5255. performed with the Suzaku, XMM-Newton and Chandra observatories. Significant variability of the X-ray BALs is detected on timescales as short as 4 days (proper time) implying launching radii of about 6 times the Schwarzschild radius. The fitted width of the X-ray absorption troughs imply a large gradient in the outflow velocity of the X-ray absorbers with projected outflow velocities of up to 0.5c. The notch-like shape of the detected X-ray BALs are similar to those produced in recent numerical simulations (i.e. Schurch & Done 2007) that include radiative transfer calculations through highly ionized X-ray absorbers outflowing at near relativistic velocities. We provide preliminary constraints of the outflows properties.

  11. Broad-spectrum suppression of innate immunity is required for colonization of Arabidopsis roots by the fungus Piriformospora indica.

    Science.gov (United States)

    Jacobs, Sophie; Zechmann, Bernd; Molitor, Alexandra; Trujillo, Marco; Petutschnig, Elena; Lipka, Volker; Likpa, Volker; Kogel, Karl-Heinz; Schäfer, Patrick

    2011-06-01

    Piriformospora indica is a root-colonizing basidiomycete that confers a wide range of beneficial traits to its host. The fungus shows a biotrophic growth phase in Arabidopsis (Arabidopsis thaliana) roots followed by a cell death-associated colonization phase, a colonization strategy that, to our knowledge, has not yet been reported for this plant. P. indica has evolved an extraordinary capacity for plant root colonization. Its broad host spectrum encompasses gymnosperms and monocotyledonous as well as dicotyledonous angiosperms, which suggests that it has an effective mechanism(s) for bypassing or suppressing host immunity. The results of our work argue that P. indica is confronted with a functional root immune system. Moreover, the fungus does not evade detection but rather suppresses immunity triggered by various microbe-associated molecular patterns. This ability to suppress host immunity is compromised in the jasmonate mutants jasmonate insensitive1-1 and jasmonate resistant1-1. A quintuple-DELLA mutant displaying constitutive gibberellin (GA) responses and the GA biosynthesis mutant ga1-6 (for GA requiring 1) showed higher and lower degrees of colonization, respectively, in the cell death-associated stage, suggesting that P. indica recruits GA signaling to help establish proapoptotic root cell colonization. Our study demonstrates that mutualists, like pathogens, are confronted with an effective innate immune system in roots and that colonization success essentially depends on the evolution of strategies for immunosuppression.

  12. Unraveling novel broad-spectrum antibacterial targets in food and waterborne pathogens using comparative genomics and protein interaction network analysis.

    Science.gov (United States)

    Jadhav, Ankush; Shanmugham, Buvaneswari; Rajendiran, Anjana; Pan, Archana

    2014-10-01

    Food and waterborne diseases are a growing concern in terms of human morbidity and mortality worldwide, even in the 21st century, emphasizing the need for new therapeutic interventions for these diseases. The current study aims at prioritizing broad-spectrum antibacterial targets, present in multiple food and waterborne bacterial pathogens, through a comparative genomics strategy coupled with a protein interaction network analysis. The pathways unique and common to all the pathogens under study (viz., methane metabolism, d-alanine metabolism, peptidoglycan biosynthesis, bacterial secretion system, two-component system, C5-branched dibasic acid metabolism), identified by comparative metabolic pathway analysis, were considered for the analysis. The proteins/enzymes involved in these pathways were prioritized following host non-homology analysis, essentiality analysis, gut flora non-homology analysis and protein interaction network analysis. The analyses revealed a set of promising broad-spectrum antibacterial targets, present in multiple food and waterborne pathogens, which are essential for bacterial survival, non-homologous to host and gut flora, and functionally important in the metabolic network. The identified broad-spectrum candidates, namely, integral membrane protein/virulence factor (MviN), preprotein translocase subunits SecB and SecG, carbon storage regulator (CsrA), and nitrogen regulatory protein P-II 1 (GlnB), contributed by the peptidoglycan pathway, bacterial secretion systems and two-component systems, were also found to be present in a wide range of other disease-causing bacteria. Cytoplasmic proteins SecG, CsrA and GlnB were considered as drug targets, while membrane proteins MviN and SecB were classified as vaccine targets. The identified broad-spectrum targets can aid in the design and development of antibacterial agents not only against food and waterborne pathogens but also against other pathogens. Copyright © 2014 Elsevier B.V. All rights

  13. A veritable menagerie of heritable bacteria from ants, butterflies, and beyond: broad molecular surveys and a systematic review.

    Directory of Open Access Journals (Sweden)

    Jacob A Russell

    Full Text Available Maternally transmitted bacteria have been important players in the evolution of insects and other arthropods, affecting their nutrition, defense, development, and reproduction. Wolbachia are the best studied among these and typically the most prevalent. While several other bacteria have independently evolved a heritable lifestyle, less is known about their host ranges. Moreover, most groups of insects have not had their heritable microflora systematically surveyed across a broad range of their taxonomic diversity. To help remedy these shortcomings we used diagnostic PCR to screen for five groups of heritable symbionts-Arsenophonus spp., Cardinium hertigii, Hamiltonella defensa, Spiroplasma spp., and Wolbachia spp.-across the ants and lepidopterans (focusing, in the latter case, on two butterfly families-the Lycaenidae and Nymphalidae. We did not detect Cardinium or Hamiltonella in any host. Wolbachia were the most widespread, while Spiroplasma (ants and lepidopterans and Arsenophonus (ants only were present at low levels. Co-infections with different Wolbachia strains appeared especially common in ants and less so in lepidopterans. While no additional facultative heritable symbionts were found among ants using universal bacterial primers, microbes related to heritable enteric bacteria were detected in several hosts. In summary, our findings show that Wolbachia are the dominant heritable symbionts of ants and at least some lepidopterans. However, a systematic review of symbiont frequencies across host taxa revealed that this is not always the case across other arthropods. Furthermore, comparisons of symbiont frequencies revealed that the prevalence of Wolbachia and other heritable symbionts varies substantially across lower-level arthropod taxa. We discuss the correlates, potential causes, and implications of these patterns, providing hypotheses on host attributes that may shape the distributions of these influential bacteria.

  14. Nanoparticles functionalized with supramolecular host-guest systems for nanomedicine and healthcare.

    Science.gov (United States)

    Wu, Zilong; Song, Nan; Menz, Ryan; Pingali, Bharadwaj; Yang, Ying-Wei; Zheng, Yuebing

    2015-05-01

    Synthetic macrocyclic host compounds can interact with suitable guest molecules via noncovalent interactions to form functional supramolecular systems. With the synergistic integration of the response of molecules and the unique properties at the nanoscale, nanoparticles functionalized with the host-guest supramolecular systems have shown great potentials for a broad range of applications in the fields of nanoscience and nanotechnology. In this review article, we focus on the applications of the nanoparticles functionalized with supramolecular host-guest systems in nanomedicine and healthcare, including therapeutic delivery, imaging, sensing and removal of harmful substances. A large number of examples are included to elucidate the working mechanisms, advantages, limitations and future developments of the nanoparticle-supramolecule systems in these applications.

  15. A reservoir of drug-resistant pathogenic bacteria in asymptomatic hosts.

    Directory of Open Access Journals (Sweden)

    Gabriel G Perron

    Full Text Available The population genetics of pathogenic bacteria has been intensively studied in order to understand the spread of disease and the evolution of virulence and drug resistance. However, much less attention has been paid to bacterial carriage populations, which inhabit hosts without producing disease. Since new virulent strains that cause disease can be recruited from the carriage population of bacteria, our understanding of infectious disease is seriously incomplete without knowledge on the population structure of pathogenic bacteria living in an asymptomatic host. We report the first extensive survey of the abundance and diversity of a human pathogen in asymptomatic animal hosts. We have found that asymptomatic swine from livestock productions frequently carry populations of Salmonella enterica with a broad range of drug-resistant strains and genetic diversity greatly exceeding that previously described. This study shows how agricultural practice and human intervention may lead and influence the evolution of a hidden reservoir of pathogens, with important implications for human health.

  16. A mastoparan-derived peptide has broad-spectrum antiviral activity against enveloped viruses.

    Science.gov (United States)

    Sample, Christopher J; Hudak, Kathryn E; Barefoot, Brice E; Koci, Matthew D; Wanyonyi, Moses S; Abraham, Soman; Staats, Herman F; Ramsburg, Elizabeth A

    2013-10-01

    Broad-spectrum antiviral drugs are urgently needed to treat individuals infected with new and re-emerging viruses, or with viruses that have developed resistance to antiviral therapies. Mammalian natural host defense peptides (mNHP) are short, usually cationic, peptides that have direct antimicrobial activity, and which in some instances activate cell-mediated antiviral immune responses. Although mNHP have potent activity in vitro, efficacy trials in vivo of exogenously provided mNHP have been largely disappointing, and no mNHP are currently licensed for human use. Mastoparan is an invertebrate host defense peptide that penetrates lipid bilayers, and we reasoned that a mastoparan analog might interact with the lipid component of virus membranes and thereby reduce infectivity of enveloped viruses. Our objective was to determine whether mastoparan-derived peptide MP7-NH2 could inactivate viruses of multiple types, and whether it could stimulate cell-mediated antiviral activity. We found that MP7-NH2 potently inactivated a range of enveloped viruses. Consistent with our proposed mechanism of action, MP7-NH2 was not efficacious against a non-enveloped virus. Pre-treatment of cells with MP7-NH2 did not reduce the amount of virus recovered after infection, which suggested that the primary mechanism of action in vitro was direct inactivation of virus by MP7-NH2. These results demonstrate for the first time that a mastoparan derivative has broad-spectrum antiviral activity in vitro and suggest that further investigation of the antiviral properties of mastoparan peptides in vivo is warranted. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Selection of common bean to broad environmental adaptation in Haiti

    Science.gov (United States)

    Common bean (Phaseolus vulgaris L.) cultivars in Haiti need adaptation to a broad range of environments and resistance to the most important diseases such as Bean Golden Yellow Mosaic Virus. The Legume Breeding Program (LBP), a collaborative effort of the AREA project (USAID funded through IFAS/Univ...

  18. Response to host volatiles by native and introduced populations of Dendroctonus valens (Coleoptera: Curculionidae, Scolytinae) in North America and China.  Journal of Chemical Ecology 33: 131-146.

    Science.gov (United States)

    N. Erbilgin; S.R. Mori; J.H. Sun; J.D. Stein; D.R. Owen; L.D. Merrill; R. Campos Bolande; os; K.F. Raffa; T. Mendez Montiel; D.L. Wood; N.E.  Gillette

    2007-01-01

    Bark beetles (Coleoptera: Curculionidae, Scolytinae) have specialized feeding habits, and commonly colonize only one or a few closely related host genera in their geographical ranges. The red turpentine beetle, Dendroctonus valens LeConte, has a broad geographic distribution in North America and exploits volatile cues from a wide variety of pines...

  19. Differential Host Plant-Associated Genetic Variation Between Sympatric Mite Species of the Genus Oligonychus (Acari: Tetranychidae).

    Science.gov (United States)

    Guzman-Valencia, Stephanie; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Vega-Muñoz, Ricardo

    2017-04-01

    Adaptation to different host plants can lead to host-associated differentiation (HAD). The mites Oligonychus perseae and Oligonychus punicae have a broad range of host plants, but, to date, records of them coexisting sympatrically had only been reported on avocado. However, our field observations showed both species coexisting on host plants other than avocado. The lack of previous records of these mites on the host plants studied here suggests only recent divergence to new host plant species. Previous studies showed that O. punicae had a limited migration capacity compared with O. perseae, suggesting that O. punicae is more likely to develop a close host plant relationship leading to HAD. Adults of both species were collected from trees hosting both mite species. Three genera of host plants considered were Persea, Salix, and Alnus; two species within one genus were Alnus jorullensis and Alnus acuminata; and three varieties within one species were Persea americana var. Fuerte, var. Hass, and var. Criollo, a noncommercial variety. Using sequence data from a segment of the mitochondrial cytochrome oxidase subunit I, the phylogenetic relationships and genetic population structure of both mite species in relation to the host plant were determined. Oligonychus perseae populations showed a significant population structure in relation to host plant at the species and genus level, but there was no effect of variety. In contrast, host plant explained none of the genetic variation among O. punicae populations. The potential role of coexistence mechanisms in the contrasting genetic population structure of both mite species is discussed. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. [The broad bean's syndrome in ancient Egypt].

    Science.gov (United States)

    Lippi, D

    1989-01-01

    The problem of broad bean's syndrome and lathyrism in ancient Greece has been deeply studied, with particular referrement to the hypothetic medica and mystical reasons of the Pythagoric order not to eat broad beans. It is impossible to prove Egyptian influence of Phythagora's precept, but we can, however, consider the hypothesis that they had noticed the potential deadly effect of broad beans' use, too, and wonder if their interduction had the same motivations.

  1. Structural host-microbiota interaction networks.

    Science.gov (United States)

    Guven-Maiorov, Emine; Tsai, Chung-Jung; Nussinov, Ruth

    2017-10-01

    Hundreds of different species colonize multicellular organisms making them "metaorganisms". A growing body of data supports the role of microbiota in health and in disease. Grasping the principles of host-microbiota interactions (HMIs) at the molecular level is important since it may provide insights into the mechanisms of infections. The crosstalk between the host and the microbiota may help resolve puzzling questions such as how a microorganism can contribute to both health and disease. Integrated superorganism networks that consider host and microbiota as a whole-may uncover their code, clarifying perhaps the most fundamental question: how they modulate immune surveillance. Within this framework, structural HMI networks can uniquely identify potential microbial effectors that target distinct host nodes or interfere with endogenous host interactions, as well as how mutations on either host or microbial proteins affect the interaction. Furthermore, structural HMIs can help identify master host cell regulator nodes and modules whose tweaking by the microbes promote aberrant activity. Collectively, these data can delineate pathogenic mechanisms and thereby help maximize beneficial therapeutics. To date, challenges in experimental techniques limit large-scale characterization of HMIs. Here we highlight an area in its infancy which we believe will increasingly engage the computational community: predicting interactions across kingdoms, and mapping these on the host cellular networks to figure out how commensal and pathogenic microbiota modulate the host signaling and broadly cross-species consequences.

  2. The anomalous tides near Broad Sound

    Science.gov (United States)

    Middleton, Jason H.; Buchwald, V. T.; Huthnance, John M.

    Observations of tidal current and height, in conjunction with theoretical mathematical models are used to investigate the propagation of the tide near Broad Sound, a narrowing estuary situated on a wide section of continental shelf toward the southern end of the Great Barrier Reef. The observations indicate that the dense offshore reefs severely inhibit tidal flow, with the result that tides flood toward Broad Sound from the north and from the south, along the main lagoon. There is a local magnification of the semi-diurnal tides within Broad Sound itself. Models of flow across reefs confirm the effectiveness of dense, shallow, and broad reefs in acting as a barrier to the tide. The diffraction of tides through large gaps in the reef is modelled using conformal mapping techniques and with the inclusion of energy leakage, the diffraction model predicts magnification of the semi-diurnal tidal heights by a factor of about 4 and a phase lag of 3 h on the shelf near Broad Sound, these values being consistent with observation. The observed convergence of the tide close to, and within Broad Sound itself is consistent with the proximity of the semi-diurnal tidal period to the natural period for flow in Broad Sound, considered as a narrowing estuary. This results in further amplification, by an additional factor of about 1.5, so that the tides in Broad Sound are increased by a factor of between 5 and 6, altogether, compared with those elsewhere on the east Australian coast.

  3. Broad Prize: Do the Successes Spread?

    Science.gov (United States)

    Samuels, Christina A.

    2011-01-01

    When the Broad Prize for Urban Education was created in 2002, billionaire philanthropist Eli Broad said he hoped the awards, in addition to rewarding high-performing school districts, would foster healthy competition; boost the prestige of urban education, long viewed as dysfunctional; and showcase best practices. Over the 10 years the prize has…

  4. Broad Academy's Growing Reach Draws Scrutiny

    Science.gov (United States)

    Samuels, Christina A.

    2011-01-01

    Billionaire businessman Eli Broad, one of the country's most active philanthropists, founded the "Broad Superintendents Academy" in 2002 with an extraordinarily optimistic goal: Find leaders from both inside and outside education, train them, and have them occupying the superintendencies in a third of the 75 largest school districts--all in just…

  5. Early season host plants of Apolygus lucorum (Heteroptera: Miridae) in northern China.

    Science.gov (United States)

    Lu, Yanhui; Jiao, Zhenbiao; Wu, Kongming

    2012-10-01

    Apolygus lucorum (Meyer-Dür) (Heteroptera: Miridae) has become a severe pest of cotton and many other crops in northern China as a result of the widespread adoption of Bacillus thuringiensis (Berliner) cotton, with a corresponding reduction of broad-spectrum insecticide application in cotton fields. From the middle of April to middle June, A. lucorum feeds and develops on other host plants before dispersing to cotton fields. Effective suppression of A. lucorum populations before they enter cotton fields may be an excellent strategy for reducing the occurrence and damage of their subsequent generations in cotton fields. For that, basic information about the host plant range of A. lucorum during the early season is needed. Between 2006 and 2010, a total of 94 plant species from 41 families covering 39,956 square meters of land in natural conditions were sampled using the standard white pan beat method. Sixty-six plant species, including 45 weeds, 10 fruit trees, 5 timber trees, 4 pasture crops, and 2 arable crops were found to be hosts of A. lucorum. Among these species, Descurainia sophia (L.) Webb ex Prantl, Humulus scandens (Loureiro) Merrill, Zizyphus jujuba Miller, Vitis vinifera L., Viciafaba L., and Medicago sativa L. were identified as dominant host species because of their wide distribution and high population densities of A. lucorum. The results of this study provide useful information about the early season host range of A. lucorum, which can be used to develop effective strategies to control the pest before its dispersal to cotton fields.

  6. Distributed Bragg reflector Pb/sub 1/. sqrt. /sub x/Sn/sub x/SePb/sub 1/. sqrt. /sub x/. sqrt. /sub y/Eu/sub y/Sn/sub x/Se diode lasers with a broad single-mode tuning range

    Energy Technology Data Exchange (ETDEWEB)

    Shani, Y.; Rosman, R.; Katzir, A.; Norton, P.; Tacke, M.; Preier, H.M.

    1988-06-01

    Distributed Bragg reflector Pb/sub 1/..sqrt../sub x/Sn/sub x/SePb/sub 1/..sqrt../sub x/..sqrt../sub y/Eu/sub y/Sn/sub x/Se double heterostructure stripe geometry diode lasers were fabricated using molecular-beam epitaxy. Single-mode cw operation at about 7.8 ..mu..m was obtained for heat-sink temperatures in the range 25--75 K. the single-mode continuous tuning range was 10 cm/sup -1/. Tuning the diodes via the injection current, a range of 24 cm/sup -1/ was completely covered with single-mode emission. The reason for this wide tuning range was mode hopping to lower frequencies rather than the usual hopping to higher frequencies

  7. Recent Evolutionary Radiation and Host Plant Specialization in the Xylella fastidiosa Subspecies Native to the United States

    Science.gov (United States)

    Vickerman, Danel B.; Bromley, Robin E.; Russell, Stephanie A.; Hartman, John R.; Morano, Lisa D.; Stouthamer, Richard

    2013-01-01

    The bacterial pathogen, Xylella fastidiosa, infects many plant species in the Americas, making it a good model for investigating the genetics of host adaptation. We used multilocus sequence typing (MLST) to identify isolates of the native U.S. subsp. multiplex that were largely unaffected by intersubspecific homologous recombination (IHR) and to investigate how their evolutionary history influences plant host specialization. We identified 110 “non-IHR” isolates, 2 minimally recombinant “intermediate” ones (including the subspecific type), and 31 with extensive IHR. The non-IHR and intermediate isolates defined 23 sequence types (STs) which we used to identify 22 plant hosts (73% trees) characteristic of the subspecies. Except for almond, subsp. multiplex showed no host overlap with the introduced subspecies (subspecies fastidiosa and sandyi). MLST sequences revealed that subsp. multiplex underwent recent radiation (<25% of subspecies age) which included only limited intrasubspecific recombination (ρ/θ = 0.02); only one isolated lineage (ST50 from ash) was older. A total of 20 of the STs grouped into three loose phylogenetic clusters distinguished by nonoverlapping hosts (excepting purple leaf plum): “almond,” “peach,” and “oak” types. These host differences were not geographical, since all three types also occurred in California. ST designation was a good indicator of host specialization. ST09, widespread in the southeastern United States, only infected oak species, and all peach isolates were ST10 (from California, Florida, and Georgia). Only ST23 had a broad host range. Hosts of related genotypes were sometimes related, but often host groupings crossed plant family or even order, suggesting that phylogenetically plastic features of hosts affect bacterial pathogenicity. PMID:23354698

  8. Tomato yellow vein streak virus: relationship with Bemisia tabaci biotype B and host range Tomato yellow vein streak virus: interação com a Bemisia tabaci biótipo B e gama de hospedeiros

    Directory of Open Access Journals (Sweden)

    Ana Carolina Firmino

    2009-12-01

    Full Text Available The Tomato yellow vein streak virus (ToYVSV is a putative species of begomovirus, which was prevalent on tomato crops in São Paulo State, Brazil, until 2005. The objectives of this study were to evaluate the interaction between ToYVSV and its vector Bemisia tabaci biotype B and to identify alternative hosts for the virus. The minimum acquisition and inoculation access periods of ToYVSV by B. tabaci were 30 min and 10 min, respectively. Seventy five percent of tomato-test plants were infected when the acquisition and inoculation access periods were 24 h. The latent period of the virus in the insect was 16 h. The ToYVSV was retained by B. tabaci until 20 days after acquisition. First generation of adult whiteflies obtained from viruliferous females were virus free as shown by PCR analysis and did not transmit the virus to tomato plants. Out of 34 species of test-plants inoculated with ToYVSV only Capsicum annuum, Chenopodium amaranticolor, C. quinoa, Datura stramonium, Gomphrena globosa, Nicotiana clevelandii and N. tabacum cv. TNN were susceptible to infection. B. tabaci biotype B was able to acquire the virus from all these susceptible species, transmitting it to tomato plants.O Tomato yellow vein streak virus (ToYVSV é uma espécie putativa de begomovirus que infecta o tomateiro (Solanum lycopersicon em diversas regiões do Brasil onde se cultiva essa solanácea, sendo a espécie prevalente no estado de São Paulo até 2005. Estudou-se a interação do ToYVSV com a Bemisia tabaci biótipo B e identificaram-se hospedeiras alternativas deste vírus. Os períodos de acesso mínimo de aquisição (PAA e de inoculação (PAI foram de 30 min e 10 min, respectivamente. A porcentagem de plantas infectadas chegou até cerca de 75% após um PAA e PAI de 24 h. O período de latência do vírus no vetor foi de 16 horas. O ToYVSV foi retido pela B. tabaci até 20 dias após a aquisição do vírus. Não foi detectada transmissão do vírus para prog

  9. Measuring Prevention More Broadly, An Empirical...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Measuring Prevention More Broadly, An Empirical Assessment of CHIPRA Core Measures Differences in CHIP design and structure, across states and over time, may limit...

  10. Prospects for broadly protective influenza vaccines.

    Science.gov (United States)

    Treanor, John Jay

    2015-11-27

    The development of vaccines that could provide broad protection against antigenically variant influenza viruses has long been the ultimate prize in influenza research. Recent developments have pushed us closer to this goal, and such vaccines may now be within reach. This brief review outlines the current approaches to broadly protective vaccines, and the probable hurdles and roadblocks to achieving this goal. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Ltd.. All rights reserved.

  11. Potent host-directed small-molecule inhibitors of myxovirus RNA-dependent RNA-polymerases.

    Directory of Open Access Journals (Sweden)

    Stefanie A Krumm

    Full Text Available Therapeutic targeting of host cell factors required for virus replication rather than of pathogen components opens new perspectives to counteract virus infections. Anticipated advantages of this approach include a heightened barrier against the development of viral resistance and a broadened pathogen target spectrum. Myxoviruses are predominantly associated with acute disease and thus are particularly attractive for this approach since treatment time can be kept limited. To identify inhibitor candidates, we have analyzed hit compounds that emerged from a large-scale high-throughput screen for their ability to block replication of members of both the orthomyxovirus and paramyxovirus families. This has returned a compound class with broad anti-viral activity including potent inhibition of different influenza virus and paramyxovirus strains. After hit-to-lead chemistry, inhibitory concentrations are in the nanomolar range in the context of immortalized cell lines and human PBMCs. The compound shows high metabolic stability when exposed to human S-9 hepatocyte subcellular fractions. Antiviral activity is host-cell species specific and most pronounced in cells of higher mammalian origin, supporting a host-cell target. While the compound induces a temporary cell cycle arrest, host mRNA and protein biosynthesis are largely unaffected and treated cells maintain full metabolic activity. Viral replication is blocked at a post-entry step and resembles the inhibition profile of a known inhibitor of viral RNA-dependent RNA-polymerase (RdRp activity. Direct assessment of RdRp activity in the presence of the reagent reveals strong inhibition both in the context of viral infection and in reporter-based minireplicon assays. In toto, we have identified a compound class with broad viral target range that blocks host factors required for viral RdRp activity. Viral adaptation attempts did not induce resistance after prolonged exposure, in contrast to rapid

  12. Alloyed semiconductor nanocrystals with broad tunable band gaps.

    Science.gov (United States)

    Pan, Daocheng; Weng, Ding; Wang, Xiaolei; Xiao, Qiangfeng; Chen, Wei; Xu, Chuanlai; Yang, Zhengzhong; Lu, Yunfeng

    2009-07-28

    Nearly monodisperse alloyed (CuInS2)x(ZnS)1-x nanocrystals with cubic and hexagonal phases were successfully synthesized for the first time, and the band gaps of these alloyed nanocrystals can be tuned in the broad range of 1.5 to 3.7 eV by changing the ratio of CuInS2 to ZnS.

  13. Host specificity in phylogenetic and geographic space.

    Science.gov (United States)

    Poulin, Robert; Krasnov, Boris R; Mouillot, David

    2011-08-01

    The measurement of host specificity goes well beyond counting how many host species can successfully be used by a parasite. In particular, specificity can be assessed with respect to how closely related the host species are, or whether a parasite exploits the same or different hosts across its entire geographic range. Recent developments in the measurement of biodiversity offer a new set of analytical tools that can be used to quantify the many aspects of host specificity. We describe here the multifaceted nature of host specificity, summarize the indices available to measure its different facets one at a time or in combination, and discuss their implications for parasite evolution and disease epidemiology. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Still a host of hosts for Wolbachia: analysis of recent data suggests that 40% of terrestrial arthropod species are infected.

    Directory of Open Access Journals (Sweden)

    Roman Zug

    Full Text Available Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species.

  15. Understanding Host-Switching by Ecological Fitting.

    Directory of Open Access Journals (Sweden)

    Sabrina B L Araujo

    Full Text Available Despite the fact that parasites are highly specialized with respect to their hosts, empirical evidence demonstrates that host switching rather than co-speciation is the dominant factor influencing the diversification of host-parasite associations. Ecological fitting in sloppy fitness space has been proposed as a mechanism allowing ecological specialists to host-switch readily. That proposal is tested herein using an individual-based model of host switching. The model considers a parasite species exposed to multiple host resources. Through time host range expansion can occur readily without the prior evolution of novel genetic capacities. It also produces non-linear variation in the size of the fitness space. The capacity for host colonization is strongly influenced by propagule pressure early in the process and by the size of the fitness space later. The simulations suggest that co-adaptation may be initiated by the temporary loss of less fit phenotypes. Further, parasites can persist for extended periods in sub-optimal hosts, and thus may colonize distantly related hosts by a "stepping-stone" process.

  16. Myxozoan infections of caecilians demonstrate broad host specificity and indicate a link with human activity

    Czech Academy of Sciences Publication Activity Database

    Hartigan, Ashlie; Wilkinson, M.; Gower, D.J.; Streicher, J.W.; Holzer, Astrid S.; Okamura, B.

    2016-01-01

    Roč. 46, 5-6 (2016), s. 375-381 ISSN 0020-7519 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Myxosporea * Cystodiscus * Amphibian * Gymnophiona * frogs * captivity Subject RIV: EG - Zoology Impact factor: 3.730, year: 2016

  17. Investigating AAK1-and GAK-Regulated Virus-Host Interactions Uncovers Broad-Spectrum Antivirals

    Science.gov (United States)

    2017-02-16

    any virus. To test the hypothesis that HCV particles 157 shuttle with clathrin APs intracellularly, we utilized live cell imaging . The co-trafficking...activity, on HCV particle 179 trafficking by live cell imaging . Treatment of HCV-infected cells with sunitinib and erlotinib 180 reduced motility of...against emerging viral infections. 402 403 Using advanced live cell imaging , we provide the first direct evidence that viral particles co-404

  18. Broad adsorption of sepsis-related PAMP and DAMP molecules, mycotoxins, and cytokines from whole blood using CytoSorb® sorbent porous polymer beads.

    Directory of Open Access Journals (Sweden)

    Maryann C Gruda

    Full Text Available Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. In sepsis and septic shock, pathogen-associated molecular pattern molecules (PAMPS, such as bacterial exotoxins, cause direct cellular damage and/or trigger an immune response in the host often leading to excessive cytokine production, a maladaptive systemic inflammatory response syndrome response (SIRS, and tissue damage that releases DAMPs, such as activated complement and HMGB-1, into the bloodstream causing further organ injury. Cytokine reduction using extracorporeal blood filtration has been correlated with improvement in survival and clinical outcomes in experimental studies and clinical reports, but the ability of this technology to reduce a broader range of inflammatory mediators has not been well-described. This study quantifies the size-selective adsorption of a wide range of sepsis-related inflammatory bacterial and fungal PAMPs, DAMPs and cytokines, in a single compartment, in vitro whole blood recirculation system.Purified proteins were added to whole blood at clinically relevant concentrations and recirculated through a device filled with CytoSorb® hemoadsorbent polymer beads (CytoSorbents Corporation, USA or control (no bead device in vitro. Except for the TNF-α trimer, hemoadsorption through porous polymer bead devices reduced the levels of a broad spectrum of cytokines, DAMPS, PAMPS and mycotoxins by more than 50 percent.This study demonstrates that CytoSorb® hemoadsorbent polymer beads efficiently remove a broad spectrum of toxic PAMPS and DAMPS from blood providing an additional means of reducing the uncontrolled inflammatory cascade that contributes to a maladaptive SIRS response, organ dysfunction and death in patients with a broad range of life-threatening inflammatory conditions such as sepsis, toxic shock syndrome, necrotizing fasciitis, and other severe inflammatory conditions.

  19. Predictors of Host Specificity among Behavior-Manipulating Parasites

    DEFF Research Database (Denmark)

    Fredensborg, B. L.

    2014-01-01

    A trade-off between resource-specialization and the breadth of the ecological niche is one of the most fundamental biological characteristics. A true generalist (Jack-of-all-trades) displays a broad ecological niche with little resource specialization while the opposite is true for a resource...... of parasites and hosts. Using individual and multivariate analyses, I examined the effect of the host’s and parasite’s taxonomy, location of the parasite in the host, type of behavioral change, and the effect of debilitation on host-specificity, measured as the mean taxonomic relatedness of hosts...

  20. Broad-Spectrum Suppression of Innate Immunity Is Required for Colonization of Arabidopsis Roots by the Fungus Piriformospora indica1[C][W

    Science.gov (United States)

    Jacobs, Sophie; Zechmann, Bernd; Molitor, Alexandra; Trujillo, Marco; Petutschnig, Elena; Lipka, Volker; Kogel, Karl-Heinz; Schäfer, Patrick

    2011-01-01

    Piriformospora indica is a root-colonizing basidiomycete that confers a wide range of beneficial traits to its host. The fungus shows a biotrophic growth phase in Arabidopsis (Arabidopsis thaliana) roots followed by a cell death-associated colonization phase, a colonization strategy that, to our knowledge, has not yet been reported for this plant. P. indica has evolved an extraordinary capacity for plant root colonization. Its broad host spectrum encompasses gymnosperms and monocotyledonous as well as dicotyledonous angiosperms, which suggests that it has an effective mechanism(s) for bypassing or suppressing host immunity. The results of our work argue that P. indica is confronted with a functional root immune system. Moreover, the fungus does not evade detection but rather suppresses immunity triggered by various microbe-associated molecular patterns. This ability to suppress host immunity is compromised in the jasmonate mutants jasmonate insensitive1-1 and jasmonate resistant1-1. A quintuple-DELLA mutant displaying constitutive gibberellin (GA) responses and the GA biosynthesis mutant ga1-6 (for GA requiring 1) showed higher and lower degrees of colonization, respectively, in the cell death-associated stage, suggesting that P. indica recruits GA signaling to help establish proapoptotic root cell colonization. Our study demonstrates that mutualists, like pathogens, are confronted with an effective innate immune system in roots and that colonization success essentially depends on the evolution of strategies for immunosuppression. PMID:21474434

  1. Interspecific hybridization impacts host range and pathogenicity of filamentous microbes

    NARCIS (Netherlands)

    Depotter, Jasper R.L.; Seidl, Michael F.; Wood, Thomas A.; Thomma, Bart P.H.J.

    2016-01-01

    Interspecific hybridization is widely observed within diverse eukaryotic taxa, and is considered an important driver for genome evolution. As hybridization fuels genomic and transcriptional alterations, hybrids are adept to respond to environmental changes or to invade novel niches. This may be

  2. Pathogenicity and host range of Heterodera arenaria in coastal foredunes

    NARCIS (Netherlands)

    Van der Stoel, C.D.; Van der Putten, W.H.

    2006-01-01

    In coastal foredunes, the cyst nematode Heterodera arenaria has been supposed to play a role in degeneration of the pioneer grass Ammophila arenaria (marram grass). However, recent field surveys and field inoculation experiments suggested that the abundance of this cyst nematode is controlled by the

  3. Xanthomonas campestris pv musacearum HOST RANGE IN UGANDA

    African Journals Online (AJOL)

    A preserved pure culture was sub—cultured on. YPGA plates, harvested into sterile distilled water after 4 days and was adjusted to 10“ bacterial cells. /rnL by plate count technique. One ml of bacterial suspension was injected into the leaf petiole and shoot tips of the experimental plants of each species including banana as ...

  4. Specialized generalists: constraints on host range in some plusiine caterpillars.

    Science.gov (United States)

    Tune, R; Dussourd, D E

    2000-06-01

    Insects that feed on plants with secretory canals often cut trenches across leaves, thereby depressurizing the canals and eliminating exudation at their distal feeding site. We compared the trenching ability of three species of polyphagous plusiines (Lepidoptera: Noctuidae) and tested if trenching scores correlate with larval growth. The three plusiines (Trichoplusia ni, Pseudoplusia includens, and Rachiplusia ou) were each tested on prickly lettuce, Lactuca serriola (Asteraceae), which has latex canals, and on Italian parsley, Petroselinum crispum (Apiaceae) with oil ducts. To ascertain how secretory canals affect performance, larvae were tested on intact leaves and on excised leaves with depleted canals. T. ni larvae cut trenches in both plant species, whereas P. includens only trenched prickly lettuce and R. ou only trenched Italian parsley. Intact leaves of Italian parsley were acceptable to all three species. Trenching varied in T. ni and R. ou, but did not correlate significantly with larval growth. In contrast, trenching was required for feeding on intact prickly lettuce. Final-instar T. ni all cut trenches and developed rapidly. P. includens varied in trenching and performance; their trenching scores correlated with growth. R. ou larvae did not trench or feed even though most R. ou on intact Italian parsley cut at least partial trenches. All three plusiine species developed rapidly on excised leaves of both plant species, documenting the suitability of these plants when canals are inactivated. Our results document the efficacy of latex canals as a plant defense and suggest that trenching ability alone does not permit feeding. Larvae must also recognize the need to trench and must tolerate deterrent exudates during the trenching procedure.

  5. Human monoclonal antibodies broadly neutralizing against influenza B virus.

    Directory of Open Access Journals (Sweden)

    Mayo Yasugi

    2013-02-01

    Full Text Available Influenza virus has the ability to evade host immune surveillance through rapid viral genetic drift and reassortment; therefore, it remains a continuous public health threat. The development of vaccines producing broadly reactive antibodies, as well as therapeutic strategies using human neutralizing monoclonal antibodies (HuMAbs with global reactivity, has been gathering great interest recently. Here, three hybridoma clones producing HuMAbs against influenza B virus, designated 5A7, 3A2 and 10C4, were prepared using peripheral lymphocytes from vaccinated volunteers, and were investigated for broad cross-reactive neutralizing activity. Of these HuMAbs, 3A2 and 10C4, which recognize the readily mutable 190-helix region near the receptor binding site in the hemagglutinin (HA protein, react only with the Yamagata lineage of influenza B virus. By contrast, HuMAb 5A7 broadly neutralizes influenza B strains that were isolated from 1985 to 2006, belonging to both Yamagata and Victoria lineages. Epitope mapping revealed that 5A7 recognizes 316G, 318C and 321W near the C terminal of HA1, a highly conserved region in influenza B virus. Indeed, no mutations in the amino acid residues of the epitope region were induced, even after the virus was passaged ten times in the presence of HuMAb 5A7. Moreover, 5A7 showed significant therapeutic efficacy in mice, even when it was administered 72 hours post-infection. These results indicate that 5A7 is a promising candidate for developing therapeutics, and provide insight for the development of a universal vaccine against influenza B virus.

  6. Learning from host-defense peptides: cationic, amphipathic peptoids with potent anticancer activity.

    Science.gov (United States)

    Huang, Wei; Seo, Jiwon; Willingham, Stephen B; Czyzewski, Ann M; Gonzalgo, Mark L; Weissman, Irving L; Barron, Annelise E

    2014-01-01

    Cationic, amphipathic host defense peptides represent a promising group of agents to be developed for anticancer applications. Poly-N-substituted glycines, or peptoids, are a class of biostable, peptidomimetic scaffold that can display a great diversity of side chains in highly tunable sequences via facile solid-phase synthesis. Herein, we present a library of anti-proliferative peptoids that mimics the cationic, amphipathic structural feature of the host defense peptides and explore the relationships between the structure, anticancer activity and selectivity of these peptoids. Several peptoids are found to be potent against a broad range of cancer cell lines at low-micromolar concentrations including cancer cells with multidrug resistance (MDR), causing cytotoxicity in a concentration-dependent manner. They can penetrate into cells, but their cytotoxicity primarily involves plasma membrane perturbations. Furthermore, peptoid 1, the most potent peptoid synthesized, significantly inhibited tumor growth in a human breast cancer xenotransplantation model without any noticeable acute adverse effects in mice. Taken together, our work provided important structural information for designing host defense peptides or their mimics for anticancer applications. Several cationic, amphipathic peptoids are very attractive for further development due to their high solubility, stability against protease degradation, their broad, potent cytotoxicity against cancer cells and their ability to overcome multidrug resistance.

  7. Learning from host-defense peptides: cationic, amphipathic peptoids with potent anticancer activity.

    Directory of Open Access Journals (Sweden)

    Wei Huang

    Full Text Available Cationic, amphipathic host defense peptides represent a promising group of agents to be developed for anticancer applications. Poly-N-substituted glycines, or peptoids, are a class of biostable, peptidomimetic scaffold that can display a great diversity of side chains in highly tunable sequences via facile solid-phase synthesis. Herein, we present a library of anti-proliferative peptoids that mimics the cationic, amphipathic structural feature of the host defense peptides and explore the relationships between the structure, anticancer activity and selectivity of these peptoids. Several peptoids are found to be potent against a broad range of cancer cell lines at low-micromolar concentrations including cancer cells with multidrug resistance (MDR, causing cytotoxicity in a concentration-dependent manner. They can penetrate into cells, but their cytotoxicity primarily involves plasma membrane perturbations. Furthermore, peptoid 1, the most potent peptoid synthesized, significantly inhibited tumor growth in a human breast cancer xenotransplantation model without any noticeable acute adverse effects in mice. Taken together, our work provided important structural information for designing host defense peptides or their mimics for anticancer applications. Several cationic, amphipathic peptoids are very attractive for further development due to their high solubility, stability against protease degradation, their broad, potent cytotoxicity against cancer cells and their ability to overcome multidrug resistance.

  8. Teaching the Broad, Interdisciplinary Impact of Evolution

    Science.gov (United States)

    Benson, David; Atlas, Pierre; Haberski, Raymond; Higgs, Jamie; Kiley, Patrick; Maxwell, Michael, Jr.; Mirola, William; Norton, Jamey

    2009-01-01

    As perhaps the most encompassing idea in biology, evolution has impacted not only science, but other academic disciplines as well. The broad, interdisciplinary impact of evolution was the theme of a course taught at Marian College, Indianapolis, Indiana in 2002, 2004, and 2006. Using a strategy that could be readily adopted at other institutions,…

  9. Developing a high quality intercultural relationship: expatriates and their local host

    DEFF Research Database (Denmark)

    van Bakel, Marian; van Oudenhoven, Jan Pieter; Gerritsen, Marinel

    2015-01-01

    range of activities during a period of nine months. Findings – Nine factors influenced the development of the contact (similarities, motivation, benefits, anxiety, expectations, busy schedules, suboptimal timing, communication breakdown, and cultural differences). Key factors were similarities...... is pivotal to benefit most from this experience, this paper examines which factors influence contact quality. Design/methodology/approach – We conducted a case study analysis of thirty-three expatriates and ten accompanying partners who were put in touch with a local host, with whom they undertook a broad......, motivation and benefits. Research limitations/implications – While some of the factors (e.g. similarities) are predictable according to the Social Penetration Theory, four factors were uniquely applicable to purposely created relationships such as contact with a local host: motivation, expectations, anxiety...

  10. History, geography and host use shape genomewide patterns of genetic variation in the redheaded pine sawfly (Neodiprion lecontei).

    Science.gov (United States)

    Bagley, Robin K; Sousa, Vitor C; Niemiller, Matthew L; Linnen, Catherine R

    2017-02-01

    Divergent host use has long been suspected to drive population differentiation and speciation in plant-feeding insects. Evaluating the contribution of divergent host use to genetic differentiation can be difficult, however, as dispersal limitation and population structure may also influence patterns of genetic variation. In this study, we use double-digest restriction-associated DNA (ddRAD) sequencing to test the hypothesis that divergent host use contributes to genetic differentiation among populations of the redheaded pine sawfly (Neodiprion lecontei), a widespread pest that uses multiple Pinus hosts throughout its range in eastern North America. Because this species has a broad range and specializes on host plants known to have migrated extensively during the Pleistocene, we first assess overall genetic structure using model-based and model-free clustering methods and identify three geographically distinct genetic clusters. Next, using a composite-likelihood approach based on the site frequency spectrum and a novel strategy for maximizing the utility of linked RAD markers, we infer the population topology and date divergence to the Pleistocene. Based on existing knowledge of Pinus refugia, estimated demographic parameters and patterns of diversity among sawfly populations, we propose a Pleistocene divergence scenario for N. lecontei. Finally, using Mantel and partial Mantel tests, we identify a significant relationship between genetic distance and geography in all clusters, and between genetic distance and host use in two of three clusters. Overall, our results indicate that Pleistocene isolation, dispersal limitation and ecological divergence all contribute to genomewide differentiation in this species and support the hypothesis that host use is a common driver of population divergence in host-specialized insects. © 2016 John Wiley & Sons Ltd.

  11. The allometry of host-pathogen interactions.

    Directory of Open Access Journals (Sweden)

    Jessica M Cable

    2007-11-01

    Full Text Available Understanding the mechanisms that control rates of disease progression in humans and other species is an important area of research relevant to epidemiology and to translating studies in small laboratory animals to humans. Body size and metabolic rate influence a great number of biological rates and times. We hypothesize that body size and metabolic rate affect rates of pathogenesis, specifically the times between infection and first symptoms or death.We conducted a literature search to find estimates of the time from infection to first symptoms (t(S and to death (t(D for five pathogens infecting a variety of bird and mammal hosts. A broad sampling of diseases (1 bacterial, 1 prion, 3 viruses indicates that pathogenesis is controlled by the scaling of host metabolism. We find that the time for symptoms to appear is a constant fraction of time to death in all but one disease. Our findings also predict that many population-level attributes of disease dynamics are likely to be expressed as dimensionless quantities that are independent of host body size.Our results show that much variability in host pathogenesis can be described by simple power functions consistent with the scaling of host metabolic rate. Assessing how disease progression is controlled by geometric relationships will be important for future research. To our knowledge this is the first study to report the allometric scaling of host/pathogen interactions.

  12. VizieR Online Data Catalog: Broad Hβ emission line in 102 Seyfert galaxies (Runco+, 2016)

    Science.gov (United States)

    Runco, J. N.; Cosens, M.; Bennert, V. N.; Scott, B.; Komossa, S.; Malkan, M. A.; Lazarova, M. S.; Auger, M. W.; Treu, T.; Park, D.

    2018-02-01

    A sample of 102 local (0.02=type-1 Seyfert galaxies was selected from the SDSS data release six (DR6) (Adelman-McCarthy et al. 2008, Cat. II/282). SDSS spectra are obtained from a 2.5 m ground-based telescope with a 3" diameter circular optical fiber and an exposure time of 54 s. SDSS spectra cover a wavelength range of 3800-9200 Å with an instrumental resolution of 170 km/s. The 102 objects selected from SDSS were observed again between 2009 January and 2010 March with the Low Resolution Imaging Spectrometer (LRIS) at the Keck 10 m telescope using a 1"x2" wide rectangular longslit aligned with the major axis of the host galaxy (given by SDSS). For eight objects with significantly weaker or apparently absent broad Hβ emission in the Keck spectra, follow-up observations were conducted in 2013 January and March with the 3 m Shane telescope of Lick observatory using the Kast spectrograph and 60 minutes total exposure time per object. The slit was aligned either along the major axis or perpendicular to it. 1D spectra were extracted using a 4 pixel (~3") width centered on the peak flux to mimic the 3" diameter circular fiber of SDSS. (2 data files).

  13. Symbiodinium (Dinophyceae) community patterns in invertebrate hosts from inshore marginal reefs of the southern Great Barrier Reef, Australia.

    Science.gov (United States)

    Tonk, Linda; Sampayo, Eugenia M; Chai, Aaron; Schrameyer, Verena; Hoegh-Guldberg, Ove

    2017-06-01

    The broad range in physiological variation displayed by Symbiodinium spp. has proven imperative during periods of environmental change and contribute to the survival of their coral host. Characterizing how host and Symbiodinium community assemblages differ across environmentally distinct habitats provides useful information to predict how corals will respond to major environmental change. Despite the extensive characterizations of Symbiodinium diversity found amongst reef cnidarians on the Great Barrier Reef (GBR) substantial biogeographic gaps exist, especially across inshore habitats. Here, we investigate Symbiodinium community patterns in invertebrates from inshore and mid-shelf reefs on the southern GBR, Australia. Dominant Symbiodinium types were characterized using denaturing gradient gel electrophoresis fingerprinting and sequencing of the ITS2 region of the ribosomal DNA. Twenty one genetically distinct Symbiodinium types including four novel types were identified from 321 reef-invertebrate samples comprising three sub-generic clades (A, C, and D). A range of host genera harbored C22a, which is normally rare or absent from inshore or low latitude reefs in the GBR. Multivariate analysis showed that host identity and sea surface temperature best explained the variation in symbiont communities across sites. Patterns of changes in Symbiodinium community assemblage over small geographic distances (100s of kilometers or less) indicate the likelihood that shifts in Symbiodinium distributions and associated host populations, may occur in response to future climate change impacting the GBR. © 2017 Phycological Society of America.

  14. Reviewing host proteins of Rhabdoviridae: Possible leads for lesser ...

    Indian Academy of Sciences (India)

    Rhabdoviridae, characterized by bullet-shaped viruses, is known for its diverse host range, which includes plants, arthropods, fishes and humans. Understanding the viral–host interactions of this family can prove beneficial in developing effective therapeutic strategies. The host proteins interacting with animal rhabdoviruses ...

  15. Compositional discordance between prokaryotic plasmids and host chromosomes

    NARCIS (Netherlands)

    van Passel, M.W.J.; Bart, A.; Luyf, A.C.M.; van Kampen, A.H.C.; van der Ende, A.

    2006-01-01

    Background: Most plasmids depend on the host replication machinery and possess partitioning genes. These properties confine plasmids to a limited range of hosts, yielding a close and presumably stable relationship between plasmid and host. Hence, it is anticipated that due to amelioration the

  16. Atomization of broad specification aircraft fuels

    Science.gov (United States)

    Skifstad, J. G.; Lefebvre, A. H.

    1980-01-01

    The atomization properties of liquid fuels for the potential use in aircraft gas turbine engines are discussed. The significance of these properties are addressed with respect to the ignition and subsequent combustion behavior of the fuel spray/air mixture. It is shown that the fuel properties which affect the atomization behavior (viscosity, surface tension, and density) are less favorable for the broad specification fuels as compared to with those for conventional fuels.

  17. Variation in RNA virus mutation rates across host cells.

    Directory of Open Access Journals (Sweden)

    Marine Combe

    2014-01-01

    Full Text Available It is well established that RNA viruses exhibit higher rates of spontaneous mutation than DNA viruses and microorganisms. However, their mutation rates vary amply, from 10(-6 to 10(-4 substitutions per nucleotide per round of copying (s/n/r and the causes of this variability remain poorly understood. In addition to differences in intrinsic fidelity or error correction capability, viral mutation rates may be dependent on host factors. Here, we assessed the effect of the cellular environment on the rate of spontaneous mutation of the vesicular stomatitis virus (VSV, which has a broad host range and cell tropism. Luria-Delbrück fluctuation tests and sequencing showed that VSV mutated similarly in baby hamster kidney, murine embryonic fibroblasts, colon cancer, and neuroblastoma cells (approx. 10(-5 s/n/r. Cell immortalization through p53 inactivation and oxygen levels (1-21% did not have a significant impact on viral replication fidelity. This shows that previously published mutation rates can be considered reliable despite being based on a narrow and artificial set of laboratory conditions. Interestingly, we also found that VSV mutated approximately four times more slowly in various insect cells compared with mammalian cells. This may contribute to explaining the relatively slow evolution of VSV and other arthropod-borne viruses in nature.

  18. The Freshwater Sponge Ephydatia fluviatilis Harbours Diverse Pseudomonas Species (Gammaproteobacteria, Pseudomonadales) with Broad-Spectrum Antimicrobial Activity

    Science.gov (United States)

    Keller-Costa, Tina; Jousset, Alexandre; van Overbeek, Leo; van Elsas, Jan Dirk; Costa, Rodrigo

    2014-01-01

    Bacteria are believed to play an important role in the fitness and biochemistry of sponges (Porifera). Pseudomonas species (Gammaproteobacteria, Pseudomonadales) are capable of colonizing a broad range of eukaryotic hosts, but knowledge of their diversity and function in freshwater invertebrates is rudimentary. We assessed the diversity, structure and antimicrobial activities of Pseudomonas spp. in the freshwater sponge Ephydatia fluviatilis. Polymerase Chain Reaction – Denaturing Gradient Gel Electrophoresis (PCR-DGGE) fingerprints of the global regulator gene gacA revealed distinct structures between sponge-associated and free-living Pseudomonas communities, unveiling previously unsuspected diversity of these assemblages in freshwater. Community structures varied across E. fluviatilis specimens, yet specific gacA phylotypes could be detected by PCR-DGGE in almost all sponge individuals sampled over two consecutive years. By means of whole-genome fingerprinting, 39 distinct genotypes were found within 90 fluorescent Pseudomonas isolates retrieved from E. fluviatilis. High frequency of in vitro antibacterial (49%), antiprotozoan (35%) and anti-oomycetal (32%) activities was found among these isolates, contrasting less-pronounced basidiomycetal (17%) and ascomycetal (8%) antagonism. Culture extracts of highly predation-resistant isolates rapidly caused complete immobility or lysis of cells of the protozoan Colpoda steinii. Isolates tentatively identified as P. jessenii, P. protegens and P. oryzihabitans showed conspicuous inhibitory traits and correspondence with dominant sponge-associated phylotypes registered by cultivation-independent analysis. Our findings suggest that E. fluviatilis hosts both transient and persistent Pseudomonas symbionts displaying antimicrobial activities of potential ecological and biotechnological value. PMID:24533086

  19. Broad-Band Analysis of Polar Motion Excitations

    Science.gov (United States)

    Chen, J.

    2016-12-01

    Earth rotational changes, i.e. polar motion and length-of-day (LOD), are driven by two types of geophysical excitations: 1) mass redistribution within the Earth system, and 2) angular momentum exchange between the solid Earth (more precisely the crust) and other components of the Earth system. Accurate quantification of Earth rotational excitations has been difficult, due to the lack of global-scale observations of mass redistribution and angular momentum exchange. The over 14-years time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) have provided a unique means for quantifying Earth rotational excitations from mass redistribution in different components of the climate system. Comparisons between observed Earth rotational changes and geophysical excitations estimated from GRACE, satellite laser ranging (SLR) and climate models show that GRACE-derived excitations agree remarkably well with polar motion observations over a broad-band of frequencies. GRACE estimates also suggest that accelerated polar region ice melting in recent years and corresponding sea level rise have played an important role in driving long-term polar motion as well. With several estimates of polar motion excitations, it is possible to estimate broad-band noise variance and noise power spectra in each, given reasonable assumptions about noise independence. Results based on GRACE CSR RL05 solutions clearly outperform other estimates with the lowest noise levels over a broad band of frequencies.

  20. Host age modulates within-host parasite competition

    OpenAIRE

    Izhar, Rony; Routtu, Jarkko; Ben-Ami, Frida

    2015-01-01

    In many host populations, one of the most striking differences among hosts is their age. While parasite prevalence differences in relation to host age are well known, little is known on how host age impacts ecological and evolutionary dynamics of diseases. Using two clones of the water flea Daphnia magna and two clones of its bacterial parasite Pasteuria ramosa, we examined how host age at exposure influences within-host parasite competition and virulence. We found that multiply-exposed hosts...

  1. Hybrid grating reflector with high reflectivity and broad bandwidth

    DEFF Research Database (Denmark)

    Taghizadeh, Alireza; Park, Gyeong Cheol; Mørk, Jesper

    2014-01-01

    We suggest a new type of grating reflector denoted hybrid grating (HG) which shows large reflectivity in a broad wavelength range and has a structure suitable for realizing a vertical cavity laser with ultra-small modal volume. The properties of the grating reflector are investigated numerically...... and explained. The HG consists of an un-patterned III-V layer and a Si grating. The III-V layer has a thickness comparable to the grating layer, introduces more guided mode resonances and significantly increases the bandwidth of the reflector compared to the well-known high-index-contrast grating (HCG...

  2. A CENSUS OF BROAD-LINE ACTIVE GALACTIC NUCLEI IN NEARBY GALAXIES: COEVAL STAR FORMATION AND RAPID BLACK HOLE GROWTH

    Energy Technology Data Exchange (ETDEWEB)

    Trump, Jonathan R.; Fang, Jerome J.; Faber, S. M.; Koo, David C.; Kocevski, Dale D. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Hsu, Alexander D. [The Harker School, 500 Saratoga Avenue, San Jose, CA 95129 (United States)

    2013-02-15

    We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements from the Sloan Digital Sky Survey are used to disentangle AGN and galaxy emission, resulting in estimates of uncontaminated galaxy rest-frame color, luminosity, and stellar mass. Broad-line AGNs are distributed throughout the blue cloud and green valley at a given stellar mass, and are much rarer in quiescent (red sequence) galaxies. This is in contrast to the published host galaxy properties of weaker narrow-line AGNs, indicating that broad-line AGNs occur during a different phase in galaxy evolution. More luminous broad-line AGNs have bluer host galaxies, even at fixed mass, suggesting that the same processes that fuel nuclear activity also efficiently form stars. The data favor processes that simultaneously fuel both star formation activity and rapid supermassive black hole accretion. If AGNs cause feedback on their host galaxies in the nearby universe, the evidence of galaxy-wide quenching must be delayed until after the broad-line AGN phase.

  3. Improve Motor System Efficiency for a Broad Range of Motors with MotorMaster+ International

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-05-01

    Available at no charge, MotorMaster+ International is designed to support motor systems improvement planning at industrial facilities by identifying the most cost-effective choice when deciding to repair or replace older motor models.

  4. Comparison of broad range 16S rDNA PCR to conventional blood ...