Flower infection of Brassica oleracea with Xanthomonas campestris pv. campestris results in high levels of seed infection

NARCIS (Netherlands)

Wolf, van der J.M.; Zouwen, van der P.S.; Heijden, van der L.

2013-01-01

During seed production, Brassica seed may become infected with Xanthomonas campestris pv. campestris after systemic colonization of plants upon leaf infection, or alternatively, after flower infection. Polytunnel experiments were conducted in 2007 and 2008 to study the relative importance of these

Meningitis due to Xanthomonas maltophilia.

Directory of Open Access Journals (Sweden)

Girijaratnakumari T

1993-07-01

Full Text Available During 1st week of post-operative period, a 28 year old female patient operated for left cerebellopontine angle tumor, continued to get fever. Lumbar puncture did not reveal any organisms. She responded to ciprofloxacin. Two months later, she was readmitted with signs and symptoms of meningitis. The CSF tapped on lumbar puncture grew Xanthomonas maltophilia, Gram negative bacilli, sensitive to various antibiotics, ciprofloxacin being one of them. The patient was given ciprofloxacin for 3 weeks. On follow up, a year later she was found to be asymptomatic.

Slaat Xanthomonas dit jaar weer toe in Prunus laurocerasus

NARCIS (Netherlands)

Doorn, van J.; Dalfsen, van P.; Pham, K.T.K.

2012-01-01

Een diagnostische test moet duidelijk maken of er sprake is van Xanthomonas in Prunus laurocerasus. De bacterieziekte is namelijk makkelijk te verwarren met andere ziekten. Onderzoek, gefinancierd door het Productschap Tuinbouw, richt zich op het toetsen van moerplanten voordat hier van gestekt gaat

Natural occurrence and pathogenicity of Xanthomonas bacteria on ...

African Journals Online (AJOL)

The objectives of this study were to verify the presence of Xanthomonas bacteria on plants growing in and around enset gardens in South and Southwest Ethiopia, and to elucidate the pathogenicity of Xcm strains to cultivated and wild plants. Several economical and ornamental plants were assessed for wilting in South and ...

Genomic survey of pathogenicity determinants and VNTR markers in the cassava bacterial pathogen Xanthomonas axonopodis pv. Manihotis strain CIO151.

Science.gov (United States)

Arrieta-Ortiz, Mario L; Rodríguez-R, Luis M; Pérez-Quintero, Álvaro L; Poulin, Lucie; Díaz, Ana C; Arias Rojas, Nathalia; Trujillo, Cesar; Restrepo Benavides, Mariana; Bart, Rebecca; Boch, Jens; Boureau, Tristan; Darrasse, Armelle; David, Perrine; Dugé de Bernonville, Thomas; Fontanilla, Paula; Gagnevin, Lionel; Guérin, Fabien; Jacques, Marie-Agnès; Lauber, Emmanuelle; Lefeuvre, Pierre; Medina, Cesar; Medina, Edgar; Montenegro, Nathaly; Muñoz Bodnar, Alejandra; Noël, Laurent D; Ortiz Quiñones, Juan F; Osorio, Daniela; Pardo, Carolina; Patil, Prabhu B; Poussier, Stéphane; Pruvost, Olivier; Robène-Soustrade, Isabelle; Ryan, Robert P; Tabima, Javier; Urrego Morales, Oscar G; Vernière, Christian; Carrere, Sébastien; Verdier, Valérie; Szurek, Boris; Restrepo, Silvia; López, Camilo; Koebnik, Ralf; Bernal, Adriana

2013-01-01

Xanthomonas axonopodis pv. manihotis (Xam) is the causal agent of bacterial blight of cassava, which is among the main components of human diet in Africa and South America. Current information about the molecular pathogenicity factors involved in the infection process of this organism is limited. Previous studies in other bacteria in this genus suggest that advanced draft genome sequences are valuable resources for molecular studies on their interaction with plants and could provide valuable tools for diagnostics and detection. Here we have generated the first manually annotated high-quality draft genome sequence of Xam strain CIO151. Its genomic structure is similar to that of other xanthomonads, especially Xanthomonas euvesicatoria and Xanthomonas citri pv. citri species. Several putative pathogenicity factors were identified, including type III effectors, cell wall-degrading enzymes and clusters encoding protein secretion systems. Specific characteristics in this genome include changes in the xanthomonadin cluster that could explain the lack of typical yellow color in all strains of this pathovar and the presence of 50 regions in the genome with atypical nucleotide composition. The genome sequence was used to predict and evaluate 22 variable number of tandem repeat (VNTR) loci that were subsequently demonstrated as polymorphic in representative Xam strains. Our results demonstrate that Xanthomonas axonopodis pv. manihotis strain CIO151 possesses ten clusters of pathogenicity factors conserved within the genus Xanthomonas. We report 126 genes that are potentially unique to Xam, as well as potential horizontal transfer events in the history of the genome. The relation of these regions with virulence and pathogenicity could explain several aspects of the biology of this pathogen, including its ability to colonize both vascular and non-vascular tissues of cassava plants. A set of 16 robust, polymorphic VNTR loci will be useful to develop a multi-locus VNTR analysis

Xanthomonas citri pv. citri pathotypes

DEFF Research Database (Denmark)

Di Lorenzo, Flaviana; Silipo, Alba; Gersby, Lotte Bettina Andersen

2017-01-01

Xanthomonas citri pv. citri is the pathogen responsible for Asiatic citrus canker, one of the most serious citrus diseases worldwide. The lipopolysaccharide (LPS) molecule has been demonstrated to be involved in X. citri pv. citri virulence. Despite enormous progress in investigations of the mole...

Ecological genomics in Xanthomonas: the nature of genetic adaptation with homologous recombination and host shifts

KAUST Repository

Huang, Chao-Li; Pu, Pei-Hua; Huang, Hao-Jen; Sung, Huang-Mo; Liaw, Hung-Jiun; Chen, Yi-Min; Chen, Chien-Ming; Huang, Ming-Ban; Osada, Naoki; Gojobori, Takashi; Pai, Tun-Wen; Chen, Yu-Tin; Hwang, Chi-Chuan; Chiang, Tzen-Yuh

2015-01-01

Background: Comparative genomics provides insights into the diversification of bacterial species. Bacterial speciation usually takes place with lasting homologous recombination, which not only acts as a cohering force between diverging lineages but brings advantageous alleles favored by natural selection, and results in ecologically distinct species, e.g., frequent host shift in Xanthomonas pathogenic to various plants. Results: Using whole-genome sequences, we examined the genetic divergence in Xanthomonas campestris that infected Brassicaceae, and X. citri, pathogenic to a wider host range. Genetic differentiation between two incipient races of X. citri pv. mangiferaeindicae was attributable to a DNA fragment introduced by phages. In contrast to most portions of the genome that had nearly equivalent levels of genetic divergence between subspecies as a result of the accumulation of point mutations, 10% of the core genome involving with homologous recombination contributed to the diversification in Xanthomonas, as revealed by the correlation between homologous recombination and genomic divergence. Interestingly, 179 genes were under positive selection; 98 (54.7%) of these genes were involved in homologous recombination, indicating that foreign genetic fragments may have caused the adaptive diversification, especially in lineages with nutritional transitions. Homologous recombination may have provided genetic materials for the natural selection, and host shifts likely triggered ecological adaptation in Xanthomonas. To a certain extent, we observed positive selection nevertheless contributed to ecological divergence beyond host shifting. Conclusion: Altogether, mediated with lasting gene flow, species formation in Xanthomonas was likely governed by natural selection that played a key role in helping the deviating populations to explore novel niches (hosts) or respond to environmental cues, subsequently triggering species diversification. © Huang et al.

Ecological genomics in Xanthomonas: the nature of genetic adaptation with homologous recombination and host shifts

KAUST Repository

Huang, Chao-Li

2015-03-15

Background: Comparative genomics provides insights into the diversification of bacterial species. Bacterial speciation usually takes place with lasting homologous recombination, which not only acts as a cohering force between diverging lineages but brings advantageous alleles favored by natural selection, and results in ecologically distinct species, e.g., frequent host shift in Xanthomonas pathogenic to various plants. Results: Using whole-genome sequences, we examined the genetic divergence in Xanthomonas campestris that infected Brassicaceae, and X. citri, pathogenic to a wider host range. Genetic differentiation between two incipient races of X. citri pv. mangiferaeindicae was attributable to a DNA fragment introduced by phages. In contrast to most portions of the genome that had nearly equivalent levels of genetic divergence between subspecies as a result of the accumulation of point mutations, 10% of the core genome involving with homologous recombination contributed to the diversification in Xanthomonas, as revealed by the correlation between homologous recombination and genomic divergence. Interestingly, 179 genes were under positive selection; 98 (54.7%) of these genes were involved in homologous recombination, indicating that foreign genetic fragments may have caused the adaptive diversification, especially in lineages with nutritional transitions. Homologous recombination may have provided genetic materials for the natural selection, and host shifts likely triggered ecological adaptation in Xanthomonas. To a certain extent, we observed positive selection nevertheless contributed to ecological divergence beyond host shifting. Conclusion: Altogether, mediated with lasting gene flow, species formation in Xanthomonas was likely governed by natural selection that played a key role in helping the deviating populations to explore novel niches (hosts) or respond to environmental cues, subsequently triggering species diversification. © Huang et al.

Proposal of Xanthomonas translucens pv. pistaciae pv. nov., pathogenic to pistachio (Pistacia vera).

Science.gov (United States)

Giblot-Ducray, Danièle; Marefat, Alireza; Gillings, Michael R; Parkinson, Neil M; Bowman, John P; Ophel-Keller, Kathy; Taylor, Cathy; Facelli, Evelina; Scott, Eileen S

2009-12-01

Strains of Xanthomonas translucens have caused dieback in the Australian pistachio industry for the last 15 years. Such pathogenicity to a dicotyledonous woody host contrasts with that of other pathovars of X. translucens, which are characterized by their pathogenicity to monocotyledonous plant families. Further investigations, using DNA-DNA hybridization, gyrB gene sequencing and integron screening, were conducted to confirm the taxonomic status of the X. translucens pathogenic to pistachio. DNA-DNA hybridization provided a clear classification, at the species level, of the pistachio pathogen as a X. translucens. In the gyrB-based phylogeny, strains of the pistachio pathogen clustered among the X. translucens pathovars as two distinct lineages. Integron screening revealed that the cassette arrays of strains of the pistachio pathogen were different from those of other Xanthomonas species, and again distinguished two groups. Together with previously reported pathogenicity data, these results confirm that the pistachio pathogen is a new pathovar of X. translucens and allow hypotheses about its origin. The proposed name is Xanthomonas translucens pv. pistaciae pv. nov.

Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains; Caracterizacao quimica de biopolimeros sintetizados por Xanthomonas campestris pv pruni

Energy Technology Data Exchange (ETDEWEB)

Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia [Universidade Federal de Pelotas, RS (Brazil). Centro de Biotecnologia]. E-mail: angelita@ufpel.tche.br; claire@ufpel.tche.br; ligia@ufpel.tche.br; Galland, Griselda [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Qumica

2001-07-01

In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The {sup 13}C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

Evaluation of the radioimmunoassay, indirect enzyme linked immunosorbent assay, and dot blot assay for the identification of Xanthomonas campestris pv. phaseoli

Energy Technology Data Exchange (ETDEWEB)

Malin, E; Belden, E L; Roth, D

1985-09-01

A radioimmunoassay (RIA), an indirect competitive enzyme-linked immunosorbent assay (ELISA), and a dot-blot modification of the ELISA were evaluated for detection and identification of Xanthomonas campestris pv. phaseoli (X. c. pv. phaseoli). RIA and the dot blot tests were specific for X. c. pv. phaseoli; however, significant cross reactions occurred in the indirect competitive ELISA when using anti-X. c. pv. phaseoli antiserum against other closely related bacteria. The sensitivity level of all procedures for X. c. pv. phaseoli was approximately l0/sup 5/ colony forming unitsmL. All procedures were unsatisfactory in reliably detecting low levels of X. c. pv. phaseoli directly from extracts of bean seed. However when used in conjunction with ilution plating the dot blot assay and the RIA would be useful in specifically identifying X. c. pv. phaseoli. The relative merits of these tests for identification of X. c. pv. phaseoli are discussed.

A TALE of transposition: Tn3-like transposons play a major role in the spread of pathogenicity determinants of Xanthomonas citri and other xanthomonads.

Science.gov (United States)

Ferreira, Rafael Marini; de Oliveira, Amanda Carolina P; Moreira, Leandro M; Belasque, José; Gourbeyre, Edith; Siguier, Patricia; Ferro, Maria Inês T; Ferro, Jesus A; Chandler, Michael; Varani, Alessandro M

2015-02-17

Members of the genus Xanthomonas are among the most important phytopathogens. A key feature of Xanthomonas pathogenesis is the translocation of type III secretion system (T3SS) effector proteins (T3SEs) into the plant target cells via a T3SS. Several T3SEs and a murein lytic transglycosylase gene (mlt, required for citrus canker symptoms) are found associated with three transposition-related genes in Xanthomonas citri plasmid pXAC64. These are flanked by short inverted repeats (IRs). The region was identified as a transposon, TnXax1, with typical Tn3 family features, including a transposase and two recombination genes. Two 14-bp palindromic sequences within a 193-bp potential resolution site occur between the recombination genes. Additional derivatives carrying different T3SEs and other passenger genes occur in different Xanthomonas species. The T3SEs include transcription activator-like effectors (TALEs). Certain TALEs are flanked by the same IRs as found in TnXax1 to form mobile insertion cassettes (MICs), suggesting that they may be transmitted horizontally. A significant number of MICs carrying other passenger genes (including a number of TALE genes) were also identified, flanked by the same TnXax1 IRs and delimited by 5-bp target site duplications. We conclude that a large fraction of T3SEs, including individual TALEs and potential pathogenicity determinants, have spread by transposition and that TnXax1, which exhibits all of the essential characteristics of a functional transposon, may be involved in driving MIC transposition. We also propose that TALE genes may diversify by fork slippage during the replicative Tn3 family transposition. These mechanisms may play a crucial role in the emergence of Xanthomonas pathogenicity. Xanthomonas genomes carry many insertion sequences (IS) and transposons, which play an important role in their evolution and architecture. This study reveals a key relationship between transposons and pathogenicity determinants in

Banana Xanthomonas wilt in Ethiopia: Occurrence and insect vector ...

African Journals Online (AJOL)

Bacterial wilt caused by Xanthomonas vasicola pv. musacearum (Xvm) is an important disease of enset and banana in south and south-western Ethiopia where, the diversity of the insect fauna on banana inflorescences was unknown and the role of insects as vectors of the disease had not been studied. The objectives of ...

Structural and physiological analyses of the alkanesulphonate-binding protein (SsuA of the citrus pathogen Xanthomonas citri.

Directory of Open Access Journals (Sweden)

Fabiano Tófoli de Araújo

Full Text Available BACKGROUND: The uptake of sulphur-containing compounds plays a pivotal role in the physiology of bacteria that live in aerobic soils where organosulfur compounds such as sulphonates and sulphate esters represent more than 95% of the available sulphur. Until now, no information has been available on the uptake of sulphonates by bacterial plant pathogens, particularly those of the Xanthomonas genus, which encompasses several pathogenic species. In the present study, we characterised the alkanesulphonate uptake system (Ssu of Xanthomonas axonopodis pv. citri 306 strain (X. citri, the etiological agent of citrus canker. METHODOLOGY/PRINCIPAL FINDINGS: A single operon-like gene cluster (ssuEDACB that encodes both the sulphur uptake system and enzymes involved in desulphurisation was detected in the genomes of X. citri and of the closely related species. We characterised X. citri SsuA protein, a periplasmic alkanesulphonate-binding protein that, together with SsuC and SsuB, defines the alkanesulphonate uptake system. The crystal structure of SsuA bound to MOPS, MES and HEPES, which is herein described for the first time, provides evidence for the importance of a conserved dipole in sulphate group coordination, identifies specific amino acids interacting with the sulphate group and shows the presence of a rather large binding pocket that explains the rather wide range of molecules recognised by the protein. Isolation of an isogenic ssuA-knockout derivative of the X. citri 306 strain showed that disruption of alkanesulphonate uptake affects both xanthan gum production and generation of canker lesions in sweet orange leaves. CONCLUSIONS/SIGNIFICANCE: The present study unravels unique structural and functional features of the X. citri SsuA protein and provides the first experimental evidence that an ABC uptake system affects the virulence of this phytopathogen.

Advanced Copper Composites Against Copper-Tolerant Xanthomonas perforans and Tomato Bacterial Spot.

Science.gov (United States)

Strayer-Scherer, A; Liao, Y Y; Young, M; Ritchie, L; Vallad, G E; Santra, S; Freeman, J H; Clark, D; Jones, J B; Paret, M L

2018-02-01

Bacterial spot, caused by Xanthomonas spp., is a widespread and damaging bacterial disease of tomato (Solanum lycopersicum). For disease management, growers rely on copper bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. This study evaluated the antibacterial activity of the new copper composites core-shell copper (CS-Cu), multivalent copper (MV-Cu), and fixed quaternary ammonium copper (FQ-Cu) as potential alternatives to commercially available micron-sized copper bactericides for controlling copper-tolerant Xanthomonas perforans. In vitro, metallic copper from CS-Cu and FQ-Cu at 100 μg/ml killed the copper-tolerant X. perforans strain within 1 h of exposure. In contrast, none of the micron-sized copper rates (100 to 1,000 μg/ml) from Kocide 3000 significantly reduced copper-tolerant X. perforans populations after 48 h of exposure compared with the water control (P copper-based treatments killed the copper-sensitive X. perforans strain within 1 h. Greenhouse studies demonstrated that all copper composites significantly reduced bacterial spot disease severity when compared with copper-mancozeb and water controls (P copper composites significantly reduced disease severity when compared with water controls, using 80% less metallic copper in comparison with copper-mancozeb in field studies (P copper composites have the potential to manage copper-tolerant X. perforans and tomato bacterial spot.

Multiplexed lateral flow microarray assay for detection of citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis pv citri

Energy Technology Data Exchange (ETDEWEB)

Cary,; Bruce, R [Santa Fe, NM; Stubben, Christopher J [Los Alamos, NM

2011-03-22

The invention provides highly sensitive and specific assays for the major citrus pathogens Xylella fastidiosa and Xanthomonas axonopodis, including a field deployable multiplexed assay capable of rapidly assaying for both pathogens simultaneously. The assays are directed at particular gene targets derived from pathogenic strains that specifically cause the major citrus diseases of citrus variegated chlorosis (Xylella fastidiosa 9a5c) and citrus canker (Xanthomonas axonopodis pv citri). The citrus pathogen assays of the invention offer femtomole sensitivity, excellent linear dynamic range, and rapid and specific detection.

Assessment of genetic diversity of Xanthomonas oryzae pv. oryzae

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

@@Bacterial blight of rice, caused by Xanthomonas oryzae pv. Oryzae(Xoo. ), is one of the major rice diseases in China. Making clear the shift of genetic diversity of the pathogen will provide important information for rice breeding. Strains collected from 11 provinces located in Southern region of the Changjiang River in China were assessed by using inoculation method and IS-PCR(Insertion Sequence-Based Polymerase Chain Reaction) analysis.

Comparative proteomic analysis of Xanthomonas citri ssp. citri periplasmic proteins reveals changes in cellular envelope metabolism during in vitro pathogenicity induction.

Science.gov (United States)

Artier, Juliana; da Silva Zandonadi, Flávia; de Souza Carvalho, Flávia Maria; Pauletti, Bianca Alves; Leme, Adriana Franco Paes; Carnielli, Carolina Moretto; Selistre-de-Araujo, Heloisa Sobreiro; Bertolini, Maria Célia; Ferro, Jesus Aparecido; Belasque Júnior, José; de Oliveira, Julio Cezar Franco; Novo-Mansur, Maria Teresa Marques

2018-01-01

Citrus canker is a plant disease caused by Gram-negative bacteria from the genus Xanthomonas. The most virulent species is Xanthomonas citri ssp. citri (XAC), which attacks a wide range of citrus hosts. Differential proteomic analysis of the periplasm-enriched fraction was performed for XAC cells grown in pathogenicity-inducing (XAM-M) and pathogenicity-non-inducing (nutrient broth) media using two-dimensional electrophoresis combined with liquid chromatography-tandem mass spectrometry. Amongst the 40 proteins identified, transglycosylase was detected in a highly abundant spot in XAC cells grown under inducing condition. Additional up-regulated proteins related to cellular envelope metabolism included glucose-1-phosphate thymidylyltransferase, dTDP-4-dehydrorhamnose-3,5-epimerase and peptidyl-prolyl cis-trans-isomerase. Phosphoglucomutase and superoxide dismutase proteins, known to be involved in pathogenicity in other Xanthomonas species or organisms, were also detected. Western blot and quantitative real-time polymerase chain reaction analyses for transglycosylase and superoxide dismutase confirmed that these proteins were up-regulated under inducing condition, consistent with the proteomic results. Multiple spots for the 60-kDa chaperonin and glyceraldehyde-3-phosphate dehydrogenase were identified, suggesting the presence of post-translational modifications. We propose that substantial alterations in cellular envelope metabolism occur during the XAC infectious process, which are related to several aspects, from defence against reactive oxygen species to exopolysaccharide synthesis. Our results provide new candidates for virulence-related proteins, whose abundance correlates with the induction of pathogenicity and virulence genes, such as hrpD6, hrpG, hrpB7, hpa1 and hrpX. The results present new potential targets against XAC to be investigated in further functional studies. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Transmission of Xanthomonas campestris pv. campestris in seed production crops of cauliflower

NARCIS (Netherlands)

Kastelein, P.; Krijger, M.C.; Zouwen, van der P.S.; Steen, van der J.J.M.; Stevens, L.H.; Wolf, van der J.M.; Fernandes Vieira, J.; Amaral Villela, F.

2014-01-01

n 2011, two polytunnel greenhouse experiments were conducted on seed production farms, one under conventional conditions in the South-West (Rilland) and the other under organic conditions in the East (Voorst) of the Netherlands, to study transmission routes of Xanthomonas campestris pv. campestris

Correction: Studholme et al., Draft Genome Sequences of Xanthomonas sacchari and Two Banana-Associated Xanthomonads Reveal Insights into the Xanthomonas Group 1 clade. Genes 2011, 2, 1050–1065.

Directory of Open Access Journals (Sweden)

Murray Grant

2012-01-01

Full Text Available Following publication of our article [1], we found errors in analyses performed by the corresponding author (DJS related to the phylogenetic relationship between Xylella species and the other xanthomonads. These errors do not make any difference to the main findings and conclusions reported in our paper. For example, the phylogenetic positions of NCPPB1131, NCPPB1132 and NCPPB4393 within the Group 1 Xanthomonas species are unaffected. However, we wish to apologize to the authors of a previous work [2] for creating any negative impression on the quality of their phylogenetic analyses and to take this opportunity to rectify the errors. [...

Distinct gene expression profile of Xanthomonas retroflexus engaged in synergistic multispecies biofilm formation

DEFF Research Database (Denmark)

Hansen, Lea Benedicte Skov; Ren, Dawei; Burmølle, Mette

2017-01-01

biofilms. This study presents a comparative gene expression analysis of the Xanthomonas retroflexus transcriptome when grown in a single-species biofilm and in dual-and four-species consortia with Stenotrophomonas rhizophila, Microbacterium oxydans and Paenibacillus amylolyticus. The results revealed...

Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains

International Nuclear Information System (INIS)

Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia; Galland, Griselda

2001-01-01

In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The 13 C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

Chemical products induce resistance to Xanthomonas perforans in tomato

Directory of Open Access Journals (Sweden)

Adriana Terumi Itako

2015-09-01

Full Text Available The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM (0.025 g.L−1, fluazinam (0.25 g.L−1, pyraclostrobin (0.08 g.L−1, pyraclostrobin + methiran (0.02 g.L−1 + 2.2 g.L−1, copper oxychloride (1.50 g.L−1, mancozeb + copper oxychloride (0.88 g.L−1 + 0.60 g.L−1, and oxytetracycline (0.40 g.L−1 on control of bacterial spot. Tomatoes Santa Clara and Gisele cultivars were pulverized 3 days before inoculation with Xanthomonas perforans. The production of enzymes associated with resistance induction (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, β-1,3-glucanase, and protease was quantified from leaf samples collected 24 hours before and 24 hours after chemical spraying and at 1, 2, 4, 6, and 8 days after bacterial inoculation. All products tested controlled bacterial spot, but only ASM, pyraclostrobin, and pyraclostrobin + metiram increased the production of peroxidase in the leaves of the two tomato cultivars, and increased the production of polyphenol oxidase and β-1,3-glucanase in the Santa Clara cultivar.

Chemical products induce resistance to Xanthomonas perforans in tomato.

Science.gov (United States)

Itako, Adriana Terumi; Tolentino Júnior, João Batista; Silva Júnior, Tadeu Antônio Fernandes da; Soman, José Marcelo; Maringoni, Antonio Carlos

2015-01-01

The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM) (0.025 g.L(-1)), fluazinam (0.25 g.L(-1)), pyraclostrobin (0.08 g.L(-1)), pyraclostrobin + methiran (0.02 g.L(-1) + 2.2 g.L(-1)), copper oxychloride (1.50 g.L(-1)), mancozeb + copper oxychloride (0.88 g.L(-1) + 0.60 g.L(-1)), and oxytetracycline (0.40 g.L(-1))) on control of bacterial spot. Tomatoes Santa Clara and Gisele cultivars were pulverized 3 days before inoculation with Xanthomonas perforans. The production of enzymes associated with resistance induction (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, β-1,3-glucanase, and protease) was quantified from leaf samples collected 24 hours before and 24 hours after chemical spraying and at 1, 2, 4, 6, and 8 days after bacterial inoculation. All products tested controlled bacterial spot, but only ASM, pyraclostrobin, and pyraclostrobin + metiram increased the production of peroxidase in the leaves of the two tomato cultivars, and increased the production of polyphenol oxidase and β-1,3-glucanase in the Santa Clara cultivar.

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; 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.

Induction of mutations in citrus for the development of resistance to Xanthomonas citri (Hasse) Dowson

International Nuclear Information System (INIS)

Zubrzycki, H.M.; Diamante de Zubrzycki, A.

1982-01-01

With the aim of obtaining resistance to Xanthomonas citri in citrus, mutagenic treatment was carried out with X-rays and gamma rays on buds and seedlings. As a prerequisite, attempts were made to determine some physiological and structural differences in leaves in order to evaluate and analyse the reaction to the bacterium in qualitative and quantitative terms. Citrus were found to present 3-4 annual sproutings, each having a different intensity. Grapefruit showed a greater initial increase and final length than orange, but lemon growth was greater than all the others. According to their growth, leaves clustered in three groups. Those in the middle part of the sprout showed the greatest daily increase, followed in decreasing order by those of the base and those of the apex. In orange cultivars with different degrees of reaction to Xanthomonas citri a direct association between daily growth of leaves and susceptibility was found. In fully developed leaves the number of stomata per surface unit presented an inverse ratio with susceptibility. It was observed that in a given genotype the stomata frequency per surface unit was higher in young leaves than in developed ones. Also a direct association between the leaf area and the number of stomata per leaf was found. Natural field infections were measured in leaves of developed plants. Infection in each of the 3-4 annual sproutings depends on environmental factors during the growth period and the predisposition period of the leaves. The available variation for reaction to Xanthomonas citri was higher in oranges than in grapefruit. The abscission of each leaf depends on its degree of infection, but the cultivars classed as more resistant are those requiring a smaller affected area to provoke the leaf abscission. However, abscission of a leaf is independent of the fate of the neighbouring ones. The existence of a continuous grading of infection damage within the orange cultivars suggests a genetic component for resistance

Multiplex PCR for specific and robust detection of Xanthomonas campestris pv. musacearum in pure culture and infected plant material

DEFF Research Database (Denmark)

Adriko, John; Aritua, V.; Mortensen, Carmen Nieves

2012-01-01

The present study developed a pathovar-specific PCR for the detection of Xanthomonas campestris pv. musacearum (Xcm), the cause of banana xanthomonas wilt, by amplification of a 265-bp region of the gene encoding the general secretion pathway protein D (GspD). A distinct DNA fragment......-specific PCR was successfully multiplexed with internal control primers targeting 16S rDNA for application on DNA from bacterial cultures and with primers targeting plant mitochondrial 26S rDNA for application on DNA extracted from plant material. Diagnostic discrimination of healthy and infected plants...

Deduction of upstream sequences of Xanthomonas campestris flagellar genes responding to transcription activation by FleQ

International Nuclear Information System (INIS)

Hu, R.-M.; Yang, T.-C.; Yang, S.-H.; Tseng, Y.-H.

2005-01-01

Xanthomonas campestris pv. campestris (Xcc), a close relative to Pseudomonas aeruginosa, is the pathogen causing black rot in cruciferous plants. In P. aeruginosa, FleQ serves as a cognate activator of σ 54 in transcription from several σ 54 -dependent promoters of flagellar genes. These P. aeruginosa promoters have been analyzed for FleQ-binding sequences; however, no consensus was deduced. Xcc, although lacks fleSR, has a fleQ homologue residing among over 40 contiguously clustered flagellar genes. A fleQ mutant, Xc17fleQ, constructed by insertional mutation is deficient in FleQ protein, non-flagellated, and immobile. Transcriptional fusion assays on six putative σ 54 -dependent promoters of the flagellar genes, fliE, fliQ, fliL, flgG, flgB, and flhF, indicated that each of them is also FleQ dependent. Each of these promoters has a sequence with weak consensus to 5'-gaaacCCgccgCcgctTt-3', immediately upstream of the predicted σ 54 -binding site, with an imperfect inverted repeat containing a GC-rich center flanked by several A and T at 5'- and 3'-ends, respectively. Replacing this region in fliE promoter with a HindIII recognition sequence abolished the transcription, indicating that this region responds to transcription activation by FleQ

Acquisition and evolution of plant pathogenesis-associated gene clusters and candidate determinants of tissue-specificity in xanthomonas.

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Hong Lu

Full Text Available Xanthomonas is a large genus of plant-associated and plant-pathogenic bacteria. Collectively, members cause diseases on over 392 plant species. Individually, they exhibit marked host- and tissue-specificity. The determinants of this specificity are unknown.To assess potential contributions to host- and tissue-specificity, pathogenesis-associated gene clusters were compared across genomes of eight Xanthomonas strains representing vascular or non-vascular pathogens of rice, brassicas, pepper and tomato, and citrus. The gum cluster for extracellular polysaccharide is conserved except for gumN and sequences downstream. The xcs and xps clusters for type II secretion are conserved, except in the rice pathogens, in which xcs is missing. In the otherwise conserved hrp cluster, sequences flanking the core genes for type III secretion vary with respect to insertion sequence element and putative effector gene content. Variation at the rpf (regulation of pathogenicity factors cluster is more pronounced, though genes with established functional relevance are conserved. A cluster for synthesis of lipopolysaccharide varies highly, suggesting multiple horizontal gene transfers and reassortments, but this variation does not correlate with host- or tissue-specificity. Phylogenetic trees based on amino acid alignments of gum, xps, xcs, hrp, and rpf cluster products generally reflect strain phylogeny. However, amino acid residues at four positions correlate with tissue specificity, revealing hpaA and xpsD as candidate determinants. Examination of genome sequences of xanthomonads Xylella fastidiosa and Stenotrophomonas maltophilia revealed that the hrp, gum, and xcs clusters are recent acquisitions in the Xanthomonas lineage.Our results provide insight into the ancestral Xanthomonas genome and indicate that differentiation with respect to host- and tissue-specificity involved not major modifications or wholesale exchange of clusters, but subtle changes in a small

A simple method for DNA isolation from Xanthomonas spp.

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Gomes Luiz Humberto

2000-01-01

Full Text Available A simple DNA isolation method was developed with routine chemicals that yields high quality and integrity preparations when compared to some of the most well known protocols. The method described does not require the use of lysing enzymes, water bath and the DNA was obtained within 40 minutes The amount of nucleic acid extracted (measured in terms of absorbancy at 260 nm from strains of Xanthomonas spp., Pseudomonas spp. and Erwinia spp. was two to five times higher than that of the most commonly used method.

The role of type III effectors from Xanthomonas axonopodis pv. manihotis in virulence and suppression of plant immunity.

Science.gov (United States)

Medina, Cesar Augusto; Reyes, Paola Andrea; Trujillo, Cesar Augusto; Gonzalez, Juan Luis; Bejarano, David Alejandro; Montenegro, Nathaly Andrea; Jacobs, Jonathan M; Joe, Anna; Restrepo, Silvia; Alfano, James R; Bernal, Adriana

2018-03-01

Xanthomonas axonopodis pv. manihotis (Xam) causes cassava bacterial blight, the most important bacterial disease of cassava. Xam, like other Xanthomonas species, requires type III effectors (T3Es) for maximal virulence. Xam strain CIO151 possesses 17 predicted T3Es belonging to the Xanthomonas outer protein (Xop) class. This work aimed to characterize nine Xop effectors present in Xam CIO151 for their role in virulence and modulation of plant immunity. Our findings demonstrate the importance of XopZ, XopX, XopAO1 and AvrBs2 for full virulence, as well as a redundant function in virulence between XopN and XopQ in susceptible cassava plants. We tested their role in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) using heterologous systems. AvrBs2, XopR and XopAO1 are capable of suppressing PTI. ETI suppression activity was only detected for XopE4 and XopAO1. These results demonstrate the overall importance and diversity in functions of major virulence effectors AvrBs2 and XopAO1 in Xam during cassava infection. © 2017 BSPP AND JOHN WILEY & SONS LTD.

The molybdate-binding protein (ModA) of the plant pathogen Xanthomonas axonopodis pv. citri.

Science.gov (United States)

Balan, Andrea; Santacruz, Carolina P; Moutran, Alexandre; Ferreira, Rita C C; Medrano, Francisco J; Pérez, Carlos A; Ramos, Carlos H I; Ferreira, Luís C S

2006-12-01

The modABC operon of phytopathogen Xanthomonas axonopodis pv. citri (X. citri) encodes a putative ABC transporter involved in the uptake of the molybdate and tungstate anions. Sequence analyses showed high similarity values of ModA orthologs found in X. campestris pv. campestris (X. campestris) and Escherichia coli. The X. citri modA gene was cloned in pET28a and the recombinant protein, expressed in the E. coli BL21 (DE3) strain, purified by immobilized metal affinity chromatography. The purified protein remained soluble and specifically bound molybdate and tungstate with K(d) 0.29+/-0.12 microM and 0.58+/-0.14 microM, respectively. Additionally binding of molybdate drastically enhanced the thermal stability of the recombinant ModA as compared to the apoprotein. This is the first characterization of a ModA ortholog expressed by a phytopathogen and represents an important tool for functional, biochemical and structural analyses of molybdate transport in Xanthomonas species.

Crystallization, data collection and data processing of maltose-binding protein (MalE) from the phytopathogen Xanthomonas axonopodis pv. citri

International Nuclear Information System (INIS)

Souza, C. S.; Ferreira, L. C. S.; Thomas, L.; Barbosa, J. A. R. G.; Balan, A.

2009-01-01

The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6 1 22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 Å, and contained two molecules in the asymetric unit. It diffracted to 2.24 Å resolution

PRODUÇÃO, PROPRIEDADES REOLÓGICAS E COMPOSIÇÃO QUÍMICA DA XANTANA PRODUZIDA POR Xanthomonas axonopodis pv. phaseoli

OpenAIRE

Mayer, Lauri; Vendruscolo, Claire Tondo; Silva, Wladimir Padilha da; Moura, Andrea Bittencourt

2008-01-01

Goma xantana é um heteropolissacarídeo bacteriano sintetizado por várias espécies do gênero Xanthomonas. Devido principalmente às suas excelentes propriedades reológicas, encontra diversas aplicações na indústria alimentícia, petrolífera, cosmética e em produtos farmacêuticos. Este trabalho objetivou a produção, a análise da viscosidade, do comportamento reológico e a composição química da goma xantana produzida por sete cepas de Xanthomonas axonopodis pv. phaseoli. A produção de xantana vari...

Biofertilizantes no controle da mancha bacteriana (Xanthomonas spp.) do tomateiro

OpenAIRE

Rodrigues,Vinícius William Borges; Bueno,Thays Vieira; Tebaldi,Nilvanira Donizete

2016-01-01

RESUMO A mancha bacteriana do tomateiro, causada por quatro espécies de Xanthomonas pode provocar perdas significativas na produção da cultura e a utilização de biofertilizantes na proteção de plantas tende a reduzir a incidência de doenças. O objetivo do trabalho foi avaliar o efeito dos biofertilizantes no controle preventivo e curativo da mancha bacteriana do tomateiro. Para o controle preventivo da doença, plantas de tomate cultivar Santa Cruz Kada, com 3 a 4 folhas foram pulverizadas com...

Reaction of common bean lines to Xanthomonas axonopodis pv. phaseoli and Curtobacterium flaccumfaciens pv. flaccumfaciens

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Tamires Ribeiro

2016-12-01

Full Text Available The aim of this study was to evaluate the resistance of 58 common bean lines against common bacterial blight (Xanthomonas axonopodis pv. phaseoli and bacterial wilt (Curtobacterium flaccumfaciens pv. flaccumfaciens. The experimental design consisted of completely randomized blocks, with four replications per pathogen. The results were subjected to variance analysis by the F test at 1% probability. Significant differences between the treatments indicated different resistance levels among the lines against both pathogens. According to the Scott-Knott test, six lines were resistant to Xanthomonas axonopodis pv. phaseoli, 14 moderately resistant, and 38 susceptible. To Curtobacterium flaccumfaciens pv. flaccumfaciens, 11 lines were resistant, 26 moderately resistant and 21 susceptible. Among these, the lines Pr10-3-4/1, Pr10-5-2/1 and Pr10-5- 2/2 of the black bean group and C10-2-4/2 of the Carioca group were resistant to both major bacterial diseases affecting common bean in Brazil.

Pathogenic and genetic diversity of Xanthomonas translucens pv. undulosa in North Dakota.

Science.gov (United States)

Adhikari, Tika B; Gurung, Suraj; Hansen, Jana M; Bonman, J Michael

2012-04-01

Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa, has become more prevalent recently in North Dakota and neighboring states. From five locations in North Dakota, 226 strains of X. translucens pv. undulosa were collected and evaluated for pathogenicity and then selected strains were inoculated on a set of 12 wheat cultivars and other cereal hosts. The genetic diversity of all strains was determined using repetitive sequence-based polymerase chain reaction (rep-PCR) and insertion sequence-based (IS)-PCR. Bacterial strains were pathogenic on wheat and barley but symptom severity was greatest on wheat. Strains varied greatly in aggressiveness, and wheat cultivars also showed differential responses to several strains. The 16S ribosomal DNA sequences of the strains were identical, and distinct from those of the other Xanthomonas pathovars. Combined rep-PCR and IS-PCR data produced 213 haplotypes. Similar haplotypes were detected in more than one location. Although diversity was greatest (≈92%) among individuals within a location, statistically significant (P ≤ 0.001 or 0.05) genetic differentiation among locations was estimated, indicating geographic differentiation between pathogen populations. The results of this study provide information on the pathogen diversity in North Dakota, which will be useful to better identify and characterize resistant germplasm.

Expression of Xylella fastidiosa RpfF in citrus disrupts signaling in Xanthomonas citri subsp. citri and thereby its virulence.

Science.gov (United States)

Caserta, R; Picchi, S C; Takita, M A; Tomaz, J P; Pereira, W E L; Machado, M A; Ionescu, M; Lindow, S; De Souza, A A

2014-11-01

Xylella fastidiosa and Xanthomonas citri subsp. citri, that cause citrus variegated chlorosis (CVC) and citrus canker diseases, respectively, utilize diffusible signal factor (DSF) for quorum sensing. DSF, produced by RpfF, are similar fatty acids in both organisms, although a different set of genes is regulated by DSF in each species. Because of this similarity, Xylella fastidiosa DSF might be recognized and affect the biology of Xanthomonas citri. Therefore, transgenic Citrus sinensis and Carrizo citrange plants overexpressing the Xylella fastidiosa rpfF were inoculated with Xanthomonas citri and changes in symptoms of citrus canker were observed. X. citri biofilms formed only at wound sites on transgenic leaves and were thicker; however, bacteria were unable to break through the tissue and form pustules elsewhere. Although abundant growth of X. citri occurred at wound sites on inoculated transgenic leaves, little growth was observed on unwounded tissue. Genes in the DFS-responsive core in X. citri were downregulated in bacteria isolated from transgenic leaves. DSF-dependent expression of engA was suppressed in cells exposed to xylem sap from transgenic plants. Thus, altered symptom development appears to be due to reduced expression of virulence genes because of the presence of antagonists of DSF signaling in X. citri in rpfF-expressing plants.

Xanthomonas citri MinC Oscillates from Pole to Pole to Ensure Proper Cell Division and Shape

NARCIS (Netherlands)

Soibelmann Glock Lorenzoni, André; Dantas, Giordanni; Bergsma, Tessa; Ferreira, Henrique; Scheffers, Dirk

2017-01-01

Xanthomonas citri (Xac) is the causal agent of citrus canker, a disease that affects citrus crops and causes economic impact worldwide. To further characterize cell division in this plant pathogen, we investigated the role of the protein MinC in cell division, chromosome segregation, and

Resistance of sweet orange Pera (Citrus sinensis) genotypes to Xanthomonas citri subsp. citri under field conditions

Science.gov (United States)

Citrus canker control is based on protection measures and eradication of plants infected with Xanthomonas citri subsp. citri. Although these measures show satisfactory results, the use of resistant genotypes is an important alternative for citrus canker control. The aim of this study was to evaluate...

Biofertilizantes no controle da mancha bacteriana (Xanthomonas spp. do tomateiro

Directory of Open Access Journals (Sweden)

Vinícius William Borges Rodrigues

2016-03-01

Full Text Available RESUMO A mancha bacteriana do tomateiro, causada por quatro espécies de Xanthomonas pode provocar perdas significativas na produção da cultura e a utilização de biofertilizantes na proteção de plantas tende a reduzir a incidência de doenças. O objetivo do trabalho foi avaliar o efeito dos biofertilizantes no controle preventivo e curativo da mancha bacteriana do tomateiro. Para o controle preventivo da doença, plantas de tomate cultivar Santa Cruz Kada, com 3 a 4 folhas foram pulverizadas com os biofertilizantes (Soil-Set, Agro-Mos e Cop-R-Quick e água (testemunha; e dois dias após foram inoculadas por aspersão com a suspensão bacteriana nas concentrações 109 UFC mL-1 (OD550=0,5 e 106UFC mL-1, com o isolado UFU A35 de Xanthomonas sp. Para o controle curativo, as plantas foram inoculadas com a suspensão bacteriana, e dois dias após foram pulverizadas com os biofertilizantes e água. A severidade da mancha bacteriana foi avaliada usando uma escala diagramática; aos 3, 5, 8, 11 e 14 dias após a inoculação e calculada a área abaixo da curva de progresso de doença (AACPD. O controle preventivo foi mais eficiente no manejo da mancha bacteriana do tomateiro, e os diferentes biofertilizantes reduziram a severidade da doença.

A cell wall-degrading esterase of Xanthomonas oryzae requires a unique substrate recognition module for pathogenesis on rice.

Science.gov (United States)

Aparna, Gudlur; Chatterjee, Avradip; Sonti, Ramesh V; Sankaranarayanan, Rajan

2009-06-01

Xanthomonas oryzae pv oryzae (Xoo) causes bacterial blight, a serious disease of rice (Oryza sativa). LipA is a secretory virulence factor of Xoo, implicated in degradation of rice cell walls and the concomitant elicitation of innate immune responses, such as callose deposition and programmed cell death. Here, we present the high-resolution structural characterization of LipA that reveals an all-helical ligand binding module as a distinct functional attachment to the canonical hydrolase catalytic domain. We demonstrate that the enzyme binds to a glycoside ligand through a rigid pocket comprising distinct carbohydrate-specific and acyl chain recognition sites where the catalytic triad is situated 15 A from the anchored carbohydrate. Point mutations disrupting the carbohydrate anchor site or blocking the pocket, even at a considerable distance from the enzyme active site, can abrogate in planta LipA function, exemplified by loss of both virulence and the ability to elicit host defense responses. A high conservation of the module across genus Xanthomonas emphasizes the significance of this unique plant cell wall-degrading function for this important group of plant pathogenic bacteria. A comparison with the related structural families illustrates how a typical lipase is recruited to act on plant cell walls to promote virulence, thus providing a remarkable example of the emergence of novel functions around existing scaffolds for increased proficiency of pathogenesis during pathogen-plant coevolution.

Investigation of a Quadruplex-Forming Repeat Sequence Highly Enriched in Xanthomonas and Nostoc sp.

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Charlotte Rehm

Full Text Available In prokaryotes simple sequence repeats (SSRs with unit sizes of 1-5 nucleotides (nt are causative for phase and antigenic variation. Although an increased abundance of heptameric repeats was noticed in bacteria, reports about SSRs of 6-9 nt are rare. In particular G-rich repeat sequences with the propensity to fold into G-quadruplex (G4 structures have received little attention. In silico analysis of prokaryotic genomes show putative G4 forming sequences to be abundant. This report focuses on a surprisingly enriched G-rich repeat of the type GGGNATC in Xanthomonas and cyanobacteria such as Nostoc. We studied in detail the genomes of Xanthomonas campestris pv. campestris ATCC 33913 (Xcc, Xanthomonas axonopodis pv. citri str. 306 (Xac, and Nostoc sp. strain PCC7120 (Ana. In all three organisms repeats are spread all over the genome with an over-representation in non-coding regions. Extensive variation of the number of repetitive units was observed with repeat numbers ranging from two up to 26 units. However a clear preference for four units was detected. The strong bias for four units coincides with the requirement of four consecutive G-tracts for G4 formation. Evidence for G4 formation of the consensus repeat sequences was found in biophysical studies utilizing CD spectroscopy. The G-rich repeats are preferably located between aligned open reading frames (ORFs and are under-represented in coding regions or between divergent ORFs. The G-rich repeats are preferentially located within a distance of 50 bp upstream of an ORF on the anti-sense strand or within 50 bp from the stop codon on the sense strand. Analysis of whole transcriptome sequence data showed that the majority of repeat sequences are transcribed. The genetic loci in the vicinity of repeat regions show increased genomic stability. In conclusion, we introduce and characterize a special class of highly abundant and wide-spread quadruplex-forming repeat sequences in bacteria.

Investigation of a Quadruplex-Forming Repeat Sequence Highly Enriched in Xanthomonas and Nostoc sp.

Science.gov (United States)

Rehm, Charlotte; Wurmthaler, Lena A; Li, Yuanhao; Frickey, Tancred; Hartig, Jörg S

2015-01-01

In prokaryotes simple sequence repeats (SSRs) with unit sizes of 1-5 nucleotides (nt) are causative for phase and antigenic variation. Although an increased abundance of heptameric repeats was noticed in bacteria, reports about SSRs of 6-9 nt are rare. In particular G-rich repeat sequences with the propensity to fold into G-quadruplex (G4) structures have received little attention. In silico analysis of prokaryotic genomes show putative G4 forming sequences to be abundant. This report focuses on a surprisingly enriched G-rich repeat of the type GGGNATC in Xanthomonas and cyanobacteria such as Nostoc. We studied in detail the genomes of Xanthomonas campestris pv. campestris ATCC 33913 (Xcc), Xanthomonas axonopodis pv. citri str. 306 (Xac), and Nostoc sp. strain PCC7120 (Ana). In all three organisms repeats are spread all over the genome with an over-representation in non-coding regions. Extensive variation of the number of repetitive units was observed with repeat numbers ranging from two up to 26 units. However a clear preference for four units was detected. The strong bias for four units coincides with the requirement of four consecutive G-tracts for G4 formation. Evidence for G4 formation of the consensus repeat sequences was found in biophysical studies utilizing CD spectroscopy. The G-rich repeats are preferably located between aligned open reading frames (ORFs) and are under-represented in coding regions or between divergent ORFs. The G-rich repeats are preferentially located within a distance of 50 bp upstream of an ORF on the anti-sense strand or within 50 bp from the stop codon on the sense strand. Analysis of whole transcriptome sequence data showed that the majority of repeat sequences are transcribed. The genetic loci in the vicinity of repeat regions show increased genomic stability. In conclusion, we introduce and characterize a special class of highly abundant and wide-spread quadruplex-forming repeat sequences in bacteria.

MALDI-TOF-MS with PLS Modeling Enables Strain Typing of the Bacterial Plant Pathogen Xanthomonas axonopodis

Science.gov (United States)

Sindt, Nathan M.; Robison, Faith; Brick, Mark A.; Schwartz, Howard F.; Heuberger, Adam L.; Prenni, Jessica E.

2018-02-01

Matrix-assisted desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) is a fast and effective tool for microbial species identification. However, current approaches are limited to species-level identification even when genetic differences are known. Here, we present a novel workflow that applies the statistical method of partial least squares discriminant analysis (PLS-DA) to MALDI-TOF-MS protein fingerprint data of Xanthomonas axonopodis, an important bacterial plant pathogen of fruit and vegetable crops. Mass spectra of 32 X. axonopodis strains were used to create a mass spectral library and PLS-DA was employed to model the closely related strains. A robust workflow was designed to optimize the PLS-DA model by assessing the model performance over a range of signal-to-noise ratios (s/n) and mass filter (MF) thresholds. The optimized parameters were observed to be s/n = 3 and MF = 0.7. The model correctly classified 83% of spectra withheld from the model as a test set. A new decision rule was developed, termed the rolled-up Maximum Decision Rule (ruMDR), and this method improved identification rates to 92%. These results demonstrate that MALDI-TOF-MS protein fingerprints of bacterial isolates can be utilized to enable identification at the strain level. Furthermore, the open-source framework of this workflow allows for broad implementation across various instrument platforms as well as integration with alternative modeling and classification algorithms.

Influence of epidemiological factors on the bioherbicidal efficacy of a Xanthomonas capestris isolate on common cocklebur (Xanthium strumarium)

Science.gov (United States)

Greenhouse and controlled-environment studies were conducted to determine the effects of incubation temperature, dew period temperature and duration, plant growth stage, and cell concentration on the bioherbicidal efficacy of a highly virulent isolate (LVA987) of the bacterial pathogen, Xanthomonas ...

Mutagenesis of Xanthomonas campestris and selection of strains with enhanced Xanthan production

International Nuclear Information System (INIS)

Kamal, F.; Mehrgan, H.; Mazaheri, M.; Mortazavi, A. R.

2003-01-01

Xanthan gum is microbial polysaccharide of great commercial importance as it has been unusual rheological properties in solution and consequent range of applications. In this study, a series of mutants were isolated from Xanthomonas PTSS 1473 by ethyl methanesulfonate mutagenesis. The polysaccharide yield of one mutant, XC1473E 2 , was 30% better than that of the parent strain. It also showed higher xanthan formation of glucose consumption rates compared to the parent strain. xanthan produced by the mutant and enhanced viscosity, higher pseudo plasticity and larger molecular weight. Since mutant XC1473E 2 appeared white on agar plates, it underwent pigment extraction with methanol. Contrary to the parent strain, the mutant showed no absorption at 443 nm, i.e. the wavelength related to yellow pigment. This finding suggested that yellow pigmentation and normal xanthan biosynthesis are not necessarily concurrent. In general, mutant ZC1473e 2 seems to be a strain with interesting characteristics for use in commercial production of Xanthan

A loop-mediated isothermal amplification assay and sample preparation procedure for sensitive detection of Xanthomonas fragariae in strawberry

Science.gov (United States)

Xanthomonas fragariae is a bacterium that causes angular leaf spot of strawberry. Asymptomatic infections are common and contribute to the difficulties in disease management. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) assay with a bacterial enrichment proced...

Caracterização de isolados de Xanthomonas axonopodis pv. manihotis = Characterization of isolates of Xanthomonas axonopodis pv. manihotis

Directory of Open Access Journals (Sweden)

Roberto Luis Portz

2006-07-01

Full Text Available A bacteriose (Xanthomonas axonopodis pv. manihotis e a doenca de maior importancia economica na cultura da mandioca. Para estudar a variabilidade genetica desta bacteria no Oeste do Parana, foram realizados levantamentos em Entre Rios do Oeste, Marechal Candido Rondon, Mercedes, Missal, Nova Santa Rosa e Pato Bragado. Os isolados foram caracterizados em relacao a atividade de amilase, ƒ¿ e ƒÀ-esterase e agressividade. Dos 61 materiais vegetais coletados, obtiveram-se 19 isolados da bacteria, com maior incidencia para variedades de mesa em relacao aqueles para industria. Manivas provenientes de Pato Bragado, Entre Rios do Oeste e Mercedes apresentaram incidencias de 10, 27 e 10%, respectivamente, valores inferiores aos de Marechal Candido Rondon (50% e Nova Santa Rosa (58%. Os isolados foram agrupados em cinco, seis e 12 grupos em relacao a capacidade amilolitica, agressividade e isoenzimas de esterase, respectivamente. Nao houve relacao entre atividade de amilase e agressividade. Isolados de Marechal Candido Rondon foram mais agressivos que os provenientes das outras regioes. O agrupamento com base em esterase permitiu verificar que isolados provenientes de Entre Rios do Oeste, Nova Santa Rosa e Mercedes apresentaram alto grau de similaridade. Estes resultados indicam haver diferenciacaoentre os isolados da bacteria presentes nos municipios amostrados.The bacterial blight (Xanthomonas axonopodis pv. manihotis is the most important disease of cassava. To study the genetic variability of pathogen in the West of Parana, a research was carried out at Entre Rios do Oeste, Marechal Candido Rondon, Mercedes, Missal, Nova Santa Rosa and Pato Bragado. The isolates were characterized to amylase activity, ƒ¿ and ƒÀ-esterase and aggressiveness. From 61 collected materials, were obtained 19 bacterial isolates, with larger incidence for varieties of human consume than those for industry. Stems from Pato Bragado, Entre Rios do Oeste and Mercedes

Efect of aqueous extract from turmeric (Curcuma longa L.) in Xanthomonas axonopodis pv. manihotis.

OpenAIRE

Odair Josà Kuhn

2003-01-01

The cassava bacterial blight caused by Xanthomonas axonopodis pv. manihotis is the most importance disease of the culture and it is distributed in all the places where it is cultivated. Infected stems constitute themselves in the principal way of the bacterium dissemination to new cultivation areas. The chemical control of phytobacteria is difficult due to the products shortage, as well as, the existing ones are used exclusively in plantations of high economic value. By the other hand, the al...

Defense-Related Responses in Fruit of the Nonhost Chili Pepper against Xanthomonas axonopodis pv. glycines Infection

Directory of Open Access Journals (Sweden)

Sung Pae Chang

2016-08-01

Full Text Available Xanthomonas axonopodis pv. glycines (Xag is a necrotrophic bacterial pathogen of the soybean that causes bacterial pustules and is a nonhost pathogen of the chili pepper. In the current study, chili pepper fruit wound inoculated in planta with Xag 8ra formed necrotic lesions on the fruit surface and induced several structural and chemical barriers systemically in the fruit tissue. The initial defense response included programmed cell death of necrotizing and necrotized cells, which was characterized by nuclear DNA cleavage, as detected by TUNEL-confocal laser scanning microscopy (CLSM, and phosphatidylserine exposure on cell walls distal to the infection site, as detected by Annexin V FLUOS-CLSM. These two responses may facilitate cell killing and enhance transportation of cell wall materials used for cell wall thickening, respectively. The cells beneath the necrotic tissue were enlarged and divided to form periclinal cell walls, resulting in extensive formation of several parallel boundary layers at the later stages of infection, accompanying the deposition of wall fortification materials for strengthening structural defenses. These results suggest that nonhost resistance of chili pepper fruit against the nonhost necrotrophic pathogen Xag 8ra is activated systematically from the initial infection until termination of the infection cycle, resulting in complete inhibition of bacterial pathogenesis by utilizing organ-specific in situ physiological events governed by the expression of genes in the plant fruit organ.

Tranformasi Fragmen Dna Kromosom Xanthomonas Campestris ke dalam Escherichia Coli

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Wibowo Mangunwardoyo

2002-04-01

Full Text Available Research on DNA transformation of Xanthomonas campestris into Escherichia coli DH5αα using plasmid vector Escherichia coli (pUC19. was carried out. DNA chromosome was isolated using CTAB method, alkali lysis method was used to isolate DNA plasmid. Both of DNA plasmid and chromosome were digested using restriction enzyme EcoRI. Competent cell was prepared with CaCl2 and heat shock method for transformation procedure. The result revealed transformation obtain 5 white colonies, with transformation frequency was 1,22 x 10-8 colony/competent cell. Electrophoresis analysis showed the DNA fragment (insert in range 0.5 – 7,5 kb. Further research should be carried out to prepare the genomic library to obtain better result of transformant.

Shifts of microbial communities of wheat (Triticum aestivum L.) cultivation in a closed artificial ecosystem.

Science.gov (United States)

Qin, Youcai; Fu, Yuming; Dong, Chen; Jia, Nannan; Liu, Hong

2016-05-01

The microbial communities of plant ecosystems are in relation to plant growing environment, but the alteration in biodiversity of rhizosphere and phyllosphere microbial communities in closed and controlled environments is unknown. The purpose of this study is to analyze the change regularity of microbial communities with wheat plants dependent-cultivated in a closed artificial ecosystem. The microbial community structures in closed-environment treatment plants were investigated by a culture-dependent approach, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and Illumina Miseq high-throughput sequencing. The results indicated that the number of microbes decreased along with time, and the magnitude of bacteria, fungi, and actinomycetes were 10(7)-10(8), 10(5), and 10(3)-10(4) CFU/g (dry weight), respectively. The analysis of PCR-DGGE and Illumina Miseq revealed that the wheat leaf surface and near-root substrate had different microbial communities at different periods of wheat ecosystem development and showed that the relative highest diversity of microbial communities appeared at late and middle periods of the plant ecosystem, respectively. The results also indicated that the wheat leaf and substrate had different microbial community compositions, and the wheat substrate had higher richness of microbial community than the leaf. Flavobacterium, Pseudomonas, Paenibacillus, Enterobacter, Penicillium, Rhodotorula, Acremonium, and Alternaria were dominant in the wheat leaf samples, and Pedobacter, Flavobacterium, Halomonas, Marinobacter, Salinimicrobium, Lysobacter, Pseudomonas, Halobacillus, Xanthomonas, Acremonium, Monographella, and Penicillium were dominant populations in the wheat near-root substrate samples.

In planta gene expression analysis of Xanthomonas oryzae pathovar oryzae, African strain MAI1

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Verdier Valérie

2010-06-01

Full Text Available Abstract Background Bacterial leaf blight causes significant yield losses in rice crops throughout Asia and Africa. Although both the Asian and African strains of the pathogen, Xanthomonas oryzae pv. oryzae (Xoo, induce similar symptoms, they are nevertheless genetically different, with the African strains being more closely related to the Asian X. oryzae pv. oryzicola (Xoc. Results Changes in gene expression of the African Xoo strain MAI1 in the susceptible rice cultivar Nipponbare were profiled, using an SSH Xoo DNA microarray. Microarray hybridization was performed comparing bacteria recovered from plant tissues at 1, 3, and 6 days after inoculation (dai with bacteria grown in vitro. A total of 710 bacterial genes were found to be differentially expressed, with 407 up-regulated and 303 down-regulated. Expression profiling indicated that less than 20% of the 710 bacterial transcripts were induced in the first 24 h after inoculation, whereas 63% were differentially expressed at 6 dai. The 710 differentially expressed genes were one-end sequenced. 535 sequences were obtained from which 147 non-redundant sequences were identified. Differentially expressed genes were related to metabolism, secretion and transport, pathogen adherence to plant tissues, plant cell-wall degradation, IS elements, and virulence. In addition, various other genes encoding proteins with unknown function or showing no similarity to other proteins were also induced. The Xoo MAI1 non-redundant set of sequences was compared against several X. oryzae genomes, revealing a specific group of genes that was present only in MAI1. Numerous IS elements were also found to be differentially expressed. Quantitative real-time PCR confirmed 86% of the identified profile on a set of 14 genes selected according to the microarray analysis. Conclusions This is the first report to compare the expression of Xoo genes in planta across different time points during infection. This work shows that

Development of immunofluorescence colony staining (IFC) for detection of Xanthomonas campestris pv. vesicatoria and Clavibacter michiganensis subsp michiganensis in tomato seeds

NARCIS (Netherlands)

Nemeth, J.; Vuurde, van J.W.L.

2006-01-01

Immunofluorescence colony-staining (IFC) is based on sample pour plating in combination with immunofluorescence staining for recognition of the target colony. IFC was optimised for detecting Xanthomonas campestris pv. vesicatoria (Xcv) and Clavibacter michiganensis subsp. michiganensis (Cmm) in

Structure of a Novel N-acetyl-L-citrulline Deacetylase from Xanthomonas campestris

Energy Technology Data Exchange (ETDEWEB)

Shi,D.; Yu, X.; Roth, L.; Tuchman, M.; Allewell, N.

2007-01-01

The structure of a novel acetylcitrulline deacetylase from the plant pathogen Xanthomonas campestris has been solved by multiple-wavelength anomalous dispersion (MAD) using crystals grown from selenomethionine-substituted protein and refined at 1.75 {angstrom} resolution. The asymmetric unit of the crystal contains one monomer consisting of two domains, a catalytic domain and a dimerization domain. The catalytic domain is able to bind a single Co(II) ion at the active site with no change in confirmation. the dimerization domain forms an interface between two monomers related by a crystallographic two-fold symmetry axis. The interface is maintained by hydrophobic interactions between helices and hydrogen bonding between two {beta} strands that form a continuous {beta} sheet across the dimer interface. Because the dimers are also related by two-fold crystallographic axes, they pack together across the crystal via the dimerization domain, suggesting that higher order oligomers may form in solution. The polypeptide fold of the monomer is similar to the fold of Pseudomonas sp. carboxypeptidase G2 and Neisseria meningitidis succinyl diaminopimelate desuccinylase. Structural comparison among these enzymes allowed modeling of substrate binding and suggests a possible catalytic mechanism, in which Glu130 functions as a bifunctional general acid-base catalyst and the metal ion polarizes the carbonyl of the acetyl group.

12 CFR 225.123 - Activities closely related to banking.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Activities closely related to banking. 225.123 Section 225.123 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL... Holding Companies Interpretations § 225.123 Activities closely related to banking. (a) Effective June 15...

Glycerol as a carbon source for xantan production by Xanthomonas campestris isolates

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Bajić Bojana Ž.

2015-01-01

Full Text Available The success of xanthan biosynthesis depends on several factors, most importantly the genetic potential of the production microorganism and cultivation media composition. Cultivation media composition affects the yield and quality of the desired product as well as production costs. This is why many studies focus on finding cheap alternative raw materials, especially carbon sources, to replace commercially used glucose and sucrose. In addition to the Xanthomonas campestris ATCC 13951 which is the primary industrial production microorganism, other Xanthomonas strains can produce xanthan as well. Under the same conditions, different strains produce different amounts of the biopolymer of varying quality. The aim of this paper is to compare producibility of phytopathogenic X. campestris strains, isolated from the environment with the reference X. campestris ATCC 13951 strain and to estimate the possibility of xanthan production using alternative glycerol-based media than the synthetic glucose-based media. Submerged cultivation on the medium based on glucose or glycerol (2.0 %w/v was performed using the reference strain and eight isolated X. campestris strains. In order to assess the success of biosynthesis, xanthan yield and rheological properties were determined. Strains isolated from the environment produced yields between 2.98 g/L and 12.17 g/L on the glucose-based medium and 1.68 g/L and 6.31 g/L on the glycerol-based medium. Additionally, X. campestris ATCC 13951 provided the highest yield when using glucose (13.24 g/L, as well as glycerol-based medium (7.44 g/L. The obtained results indicate that in the applied experimental conditions and using all tested strains, glycerol is viable as a carbon source for the production of xanthan.

Effector Mimics and Integrated Decoys, the Never-Ending Arms Race between Rice and Xanthomonas oryzae

OpenAIRE

Zuluaga, Paola; Szurek, Boris; Koebnik, Ralf; Kroj, Thomas; Morel, Jean-Benoit

2017-01-01

Plants are constantly challenged by a wide range of pathogens and have therefore evolved an array of mechanisms to defend against them. In response to these defense systems, pathogens have evolved strategies to avoid recognition and suppress plant defenses (Brown and Tellier, 2011). Three recent reports dealing with the resistance of rice to Xanthomonas oryzae have added a new twist to our understanding of this fascinating co-evolutionary arms race (Ji et al., 2016; Read et al., 2016; Triplet...

The inheritance of resistance to bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in three lettuce cultivars

Science.gov (United States)

Lettuce yields can be reduced by the disease bacterial leaf spot (BLS) caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) and host resistance is the most feasible method to reduce disease losses. The cultivars La Brillante, Pavane, and Little Gem express an incompatible host-pathogen in...

Transgenic expression of the rice Xa21 pattern-recognition receptor in banana (Musa sp.) confers resistance to Xanthomonas campestris pv. musacearum.

Science.gov (United States)

Tripathi, Jaindra N; Lorenzen, Jim; Bahar, Ofir; Ronald, Pamela; Tripathi, Leena

2014-08-01

Banana Xanthomonas wilt (BXW), caused by the bacterium Xanthomonas campestris pv. musacearum (Xcm), is the most devastating disease of banana in east and central Africa. The spread of BXW threatens the livelihood of millions of African farmers who depend on banana for food security and income. There are no commercial chemicals, biocontrol agents or resistant cultivars available to control BXW. Here, we take advantage of the robust resistance conferred by the rice pattern-recognition receptor (PRR), XA21, to the rice pathogen Xanthomonas oryzae pv. oryzae (Xoo). We identified a set of genes required for activation of Xa21-mediated immunity (rax) that were conserved in both Xoo and Xcm. Based on the conservation, we hypothesized that intergeneric transfer of Xa21 would confer resistance to Xcm. We evaluated 25 transgenic lines of the banana cultivar 'Gonja manjaya' (AAB) using a rapid bioassay and 12 transgenic lines in the glasshouse for resistance against Xcm. About 50% of the transgenic lines showed complete resistance to Xcm in both assays. In contrast, all of the nontransgenic control plants showed severe symptoms that progressed to complete wilting. These results indicate that the constitutive expression of the rice Xa21 gene in banana results in enhanced resistance against Xcm. Furthermore, this work demonstrates the feasibility of PRR gene transfer between monocotyledonous species and provides a valuable new tool for controlling the BXW pandemic of banana, a staple food for 100 million people in east Africa. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

Science.gov (United States)

Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

First report in Ghana of #Xanthomonas citri# pv. #mangiferaeindicae# causing mango bacterial canker on #Mangifera indica#

OpenAIRE

Pruvost, Olivier; Boyer, Claudine; Vital, Karine; Gagnevin, Lionel; De Bruno Austin, L.; Rey, Jean-Yves

2011-01-01

Bacterial canker of mango (or bacterial black spot), caused by Xanthomonas citri pv. mangiferaeindicae, is an economically important disease in tropical and subtropical producing areas (1). X. citri pv. mangiferaeindicae can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Several months after infection, leaf lesions dry and turn light brown or ash gray. Severe leaf infection may result in abscission. F...

Meio semi-seletivo para isolamento de Xanthomonas campestris pv. viticola

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Peixoto Ana Rosa

2006-01-01

Full Text Available O cancro bacteriano causado por Xanthomonas campestris pv. viticola é a fitobacteriose mais importante da videira no Submédio São Francisco. O isolamento de X. campestris pv. viticola de tecidos vegetais infectados é dificultado pela presença de contaminantes bacterianos, entre os quais Microbacterium barkeri. Objetivando-se a formulação de meio de cultura semi-seletivo, 22 isolados de X. campestris pv. viticola foram testados com relação a 30 antibióticos. O meio semi-seletivo NYDAM (extrato de carne 3, peptona 5, glicose 10, extrato de levedura 5, ágar 18 e ampicilina 0,1 em g L-1 inibiu M. barkeri e bactérias fitopatogênicas podendo ser utilizado para isolar X. campestris pv. viticola de hospedeiros com infecção natural em campo.

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

OpenAIRE

Lucas,Gilvaine Ciavareli; Alves,Eduardo; Pereira,Ricardo Borges; Perina,Fabiano José; Souza,Ricardo Magela de

2012-01-01

The objective of this work was to evaluate the effects of plant essential oils (EOs) on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings unde...

A Xanthomonas citri subsp citri hypothetical protein related to virulence contains a non-functional HD domain and is implicated in flagellar motility.

Science.gov (United States)

Vieira, F C F; Gonçalves, A M; Mendoza, E F R; Ferreira, R M; Costa, M L M; Balbuena, T S; Sebinelli, H G; Ciancaglini, P; Pizauro Junior, J M; Ferro, J A

2017-08-31

Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp citri (Xac), severely affects most economically important citrus varieties worldwide. A previous study showed that disruption of the ORF XAC1201 from the Xac 306 strain by transposon Tn5 decreased bacterium virulence in the Rangpur lime host (Citrus limonia L. Osbeck). However, little is known regarding the possible function of the hypothetical protein XAC1201 and how it affects the virulence of Xac 306. Here, we confirmed that disruption of ORF XAC1201 reduces Xac 306 virulence in two different hosts, delaying the onset of typical symptoms. In silico analysis suggested that XAC1201 interacts with the flagellar proteins FliM and FliL, known to be an important factor for virulence. In fact, motility assays revealed that the XAC1201 mutant has a significant difference in motility compared to the wild-type Xac 306. Also, a 3-D structure model revealed modified cofactor binding sites and suggested that XAC1201 has a non-functional HD domain. This hypothesis was confirmed by enzymatic assays performed in purified, XAC1201 recombinant protein expressed in Escherichia coli, which revealed no significant activities previously associated with HD domains for the tested substrates. Thus, the role of the XAC1201 protein in Xac 306 virulence seems to be related to flagellar motility, although a non-classic role for the HD domain cannot be dismissed.

Diffusible signal factor family signals provide a fitness advantage to Xanthomonas campestris pv. campestris in interspecies competition.

Science.gov (United States)

Deng, Yinyue; Wu, Jien; Yin, Wenfang; Li, Peng; Zhou, Jianuan; Chen, Shaohua; He, Fei; Cai, Jun; Zhang, Lian-Hui

2016-05-01

Diffusible signal factor (DSF) represents a new class of widely conserved quorum sensing signals, which regulates various biological functions through intra- or interspecies signaling. The previous studies identified that there is an antagonistic interaction between Xanthomonas and Bacillus species bacteria in natural ecosystem, but the detailed molecular mechanism of interspecies competition is not clear. This study showed that Xanthomonas campestris pv. campestris (Xcc) interfered with morphological transition and sporulation of Bacillus thuringiensis in mixed cultures, whereas abrogation of the DSF synthase RpfF reduced the interference. DSF inhibited B. thuringiensis cell division and sporulation through modulation of ftsZ, which encodes an important cell division protein in bacterial cells. In addition, RpfF is essential for production of six DSF-family signals in Xcc, which employ the same signaling pathways to regulate biological functions in Xcc and play similar effects on reduction of cell division, sporulation and antibiotic resistance of B. thuringiensis. Furthermore, abrogation of RpfF decreased the competitive capability of Xcc against B. thuringiensis on the surface of Chinese cabbage leaves. Our findings provide new insights into the role of DSF-family signals in interspecies competition and depict molecular mechanisms with which Xcc competes with B. thuringiensis. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa.

Science.gov (United States)

Ainembabazi, John Herbert; Tripathi, Leena; Rusike, Joseph; Abdoulaye, Tahirou; Manyong, Victor

2015-01-01

Credible empirical evidence is scanty on the social implications of genetically modified (GM) crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA). GM banana has a potential to control the destructive banana Xanthomonas wilt disease. To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease. The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA. We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana. On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production. The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries.

Establishment of an inducing medium for type III effector secretion in Xanthomonas campestris pv. campestris

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Guo-Feng Jiang

2013-09-01

Full Text Available It is well known that the type III secretion system (T3SS and type III (T3 effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2 which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2 is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME. Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.

12 CFR 225.126 - Activities not closely related to banking.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Activities not closely related to banking. 225.126 Section 225.126 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE... Financial Holding Companies Interpretations § 225.126 Activities not closely related to banking. Pursuant to...

Effector Mimics and Integrated Decoys, the Never-Ending Arms Race between Rice and Xanthomonas oryzae.

Science.gov (United States)

Zuluaga, Paola; Szurek, Boris; Koebnik, Ralf; Kroj, Thomas; Morel, Jean-Benoit

2017-01-01

Plants are constantly challenged by a wide range of pathogens and have therefore evolved an array of mechanisms to defend against them. In response to these defense systems, pathogens have evolved strategies to avoid recognition and suppress plant defenses (Brown and Tellier, 2011). Three recent reports dealing with the resistance of rice to Xanthomonas oryzae have added a new twist to our understanding of this fascinating co-evolutionary arms race (Ji et al., 2016; Read et al., 2016; Triplett et al., 2016). They show that pathogens also develop sophisticated effector mimics to trick recognition.

Pooling ASR data for closely related languages

CSIR Research Space (South Africa)

Van Heerden, C

2010-05-01

Full Text Available We describe several experiments that were conducted to assess the viability of data pooling as a means to improve speech-recognition performance for under-resourced languages. Two groups of closely related languages from the Southern Bantu language...

Surface layers of Xanthomonas malvacearum, the cause of bacterial blight of cotton.

Science.gov (United States)

Verma, J P; Formanek, H

1981-01-01

Mureins were isolated from two strains of Xanthomonas malvacearum, a phytopathogenic bacterium causing bacterial blight of cotton. The purity of murein was 70-95 % and the amino acid and amino sugar components (glutamic acid, alanina, meso-disminopimelic acid, muramic acid and glucosamine) were present at the molar ratio of 1:1.9:1:l.12.0.85. The bacterium secreted a copious amount of slime which masked itd surface structure. The slime was composed of densley interwoven network of filamentous material originating from the cell surface and extended into the medium without and discernable boundary. The slime was secreted through surface layers pores by force, giving the effect of a spray or jet. Slime also played a role in chain formatin of baterial cells.

XocR, a LuxR solo required for virulence in Xanthomonas oryzae pv. oryzicola.

Science.gov (United States)

Xu, Huiyong; Zhao, Yancun; Qian, Guoliang; Liu, Fengquan

2015-01-01

Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak (BLS) in rice, a serious bacterial disease of rice in Asia and parts of Africa. The virulence mechanisms of Xoc are not entirely clear and control measures for BLS are poorly developed. The solo LuxR proteins are widespread and shown to be involved in virulence in some plant associated bacteria (PAB). Here, we have cloned and characterized a PAB LuxR solo from Xoc, named as XocR. Mutation of xocR almost completely impaired the virulence ability of Xoc on host rice, but did not alter the ability to trigger HR (hypersensitive response, a programmed cell death) on non-host (plant) tobacco, suggesting the diversity of function of xocR in host and non-host plants. We also provide evidence to show that xocR is involved in the regulation of growth-independent cell motility in response to a yet-to-be-identified rice signal, as mutation of xocR impaired cell swimming motility of wild-type Rs105 in the presence but not absence of rice macerate. We further found that xocR regulated the transcription of two characterized virulence-associated genes (recN and trpE) in the presence of rice macerate. The promoter regions of recN and trpE possessed a potential binding motif (an imperfect pip box-like element) of XocR, raising the possibility that XocR might directly bind the promoter regions of these two genes to regulate their transcriptional activity. Our studies add a new member of PAB LuxR solos and also provide new insights into the role of PAB LuxR solo in the virulence of Xanthomonas species.

Produção de goma xantana por cepas nativas de Xanthomonas campestris a partir de casca de cacau ou soro de leite Production of xanthan gum by Xanthomonas campestris strains native from bark cocoa or whey

Directory of Open Access Journals (Sweden)

Denis de M. Diniz

2012-01-01

Full Text Available Foi estudada a otimização do processo de produção de goma xantana a partir de casca de cacau ou soro de leite como fonte de carbono, e determinou-se o rendimento da goma obtida pela bioconversão de casca de cacau e soro de leite com a Xanthomonas campestris 1182. A goma foi produzida em meios com potássio e nitrogênio a 25 °C, 250 rpm por 120 horas. Os rendimentos foram: 2,335 g.L-1 para a sacarose; 4,995 g.L-1 para a casca de cacau seca e 12,01 g.L-1 utilizando soro de leite. Portanto, é viável a produção de goma xantana utilizando fontes de carbono como a casca de cacau e o soro de leite.The optimization of the production process of xanthan gum from cocoa husks or milk whey as carbon source was studied, and the production rate of gum obtained by the bioconversion of cocoa pods and whey was determined, using Xanthomonas campestris 1182. The gum was produced in a medium with potassium and nitrogen at 25 °C, 250 rpm for 120 hours. The results were: 2.335 g.L-1 for sucrose; 4.995 g.L-1 for cocoa dry pods and 12.01 g.L-1 using whey. Therefore, the production of xanthan gum is feasible upon using carbon sources such as cocoa hulls and whey.

Cloning of a two-component signal transduction system of Xanthomonas campestris pv. phaseoli var. fuscans strain BXPF65

DEFF Research Database (Denmark)

Chan, JWYF; Maynard, Scott; Goodwin, PH

1998-01-01

A putative two-component signal transduction system was amplified and cloned from the plant pathogenic bacterium Xanthomonas campestris pv. phaseoli var. fuscans isolate BXPF65. The 620 bp amplified fragment was sequenced and analyzed with the BLAST Enhanced Alignment Utility (BEAUTY). BEAUTY...... that the putative histidine kinase has homology with conserved “transmitter” domains of sensor proteins in two-component signal transduction systems. RFLP analysis using the putative signal transduction system showed polymorphisms among the strains....

The Host Plant Metabolite Glucose Is the Precursor of Diffusible Signal Factor (DSF) Family Signals in Xanthomonas campestris

OpenAIRE

Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

2015-01-01

Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous ad...

Limpeza clonal de mudas de videira infectadas por Xanthomonas campestris pv. viticola Clonal cleaning of grapevine plants infected by Xanthomonas campestris pv. viticola

Directory of Open Access Journals (Sweden)

Adriano Márcio Freire Silva

2013-03-01

Full Text Available O cancro bacteriano da videira é causado por Xanthomonas campestris pv. viticola (Xcv. Visando à limpeza clonal de mudas de 'Red Globe', foram estudados: tamanho ideal de ápices e gemas axilares para cultivo em meio de Galzy modificado (MGM; efeito da termoterapia (38ºC/30 dias; e ação de antibióticos na eliminação de Xcv em videiras infectadas. Os percentuais de contaminação por Xcv e de regeneração foram analisados, e as plantas obtidas foram indexadas em meio ágar nutritivo-dextrose-extrato de levedura-ampicilina (NYDAM, seguindo-se teste de patogenicidade. O cultivo de explantes com 3 mm possibilitou a obtenção de plantas livres da bactéria, com regeneração 14,3 vezes maior que explantes com 1 mm. A termoterapia de mudas infectadas, associada ao cultivo in vitro, não eliminou o patógeno. O cultivo de explantes com 10 mm, durante 40 dias em MGM + cefotaxima (300 mg L-1, proporcionou limpeza clonal das mudas. A indexação de plantas de videira regeneradas in vitro, quanto à infecção por Xcv utilizando NYDAM, seguida de teste de patogenicidade, é uma alternativa econômica e eficiente para produção de mudas de alta qualidade fitossanitária.Bacterial canker is caused by Xanthomonas campestris pv. viticola (Xcv. In order to eliminate Xcv from 'Red Globe' plants it was studied: optimal size of meristem tips and axillary buds for cultivation in modified Galzy's medium (MGM; effects of thermotherapy (38ºC/30 days; and action of antibiotics in the elimination of Xcv in infected grapevines. The percentages of contamination by Xcv and regeneration were analyzed and plants obtained were indexed using the semi-selective culture medium nutrient agar-dextrose-yeast extract-ampicilin (NYDAM followed by a pathogenicity test. The cultivation of 3 mm explants permitted to obtain plants free of bacteria with regeneration 14.3 times higher than 1 mm explants. The thermotherapy of infected plants associated to the in vitro culture

Monitoring the occurrence of bacterial spot of tomato and pepper in the Czech Republic and development of new PCR primers for detection of Xanthomonas vesicatoria

Czech Academy of Sciences Publication Activity Database

Beran, P.; Mráz, Ivan; Kokošková, B.; Bohatá, A.

2015-01-01

Roč. 141, č. 3 (2015), s. 617-621 ISSN 0929-1873 R&D Projects: GA MZe QH71229 Institutional support: RVO:60077344 Keywords : Oligonucleotides * atpD * Xanthomonas euvesicatoria * Lycopersicon esculentum Subject RIV: EE - Microbiology, Virology Impact factor: 1.494, year: 2015

Optimization of medium composition for the production of compounds effective against Xanthomonas campestris by bacillus subtilis

Directory of Open Access Journals (Sweden)

Rončević Zorana Z.

2014-01-01

Full Text Available The biocontrol agents are a very promising alternative to synthetic pesticides that are presently used to control plant diseases caused by phytopathogenic microorganisms. Members of the Bacillus genera are soil bacteria that produce significant quantities of agriculturally important bioactive compounds. Production of these compounds can be improved by changing the nutritional and environmental conditions. The aim of this study was the optimization of medium composition, using response surface methodology, for the production of compounds effective against Xanthomonas campestris ATCC 13951 by Bacillus subtilis ATCC 6633. To study the production of antimicrobial compounds by selected Bacillus strain, the producing microorganisms were cultivated on nutrient broth. The inhibition zone diameter of 18.0 mm obtained by the diffusion-disc method indicated that the used Bacillus subtilis strain produces compounds with antimicrobial activity against Xanthomonas campestris ATCC 13951. To optimize the composition of the cultivation medium in terms of glycerol, sodium nitrite and phosphates content, experiments were carried out in accordance with Box-Behnken design, and optimization of multiple responses was performed using the concept of desirability function. The developed model predicted that the maximum inhibition zone diameter (26.23 mm against tested phytopathogen is achieved when the initial content of glycerol, sodium nitrite and phosphate were 50.00 g/L, 2.85 g/L and 11.00 g/L, respectively. To minimize the consumption of medium components and costs of effluents processing, additional optimization set was made. The techno-economic analysis of the obtained results has to be done to select optimal medium composition for industrial production of antimicrobial compounds.

Biological Functions of ilvC in Branched-Chain Fatty Acid Synthesis and Diffusible Signal Factor Family Production in Xanthomonas campestris

OpenAIRE

Kai-Huai Li; Yong-Hong Yu; Hui-Juan Dong; Wen-Bin Zhang; Jin-Cheng Ma; Hai-Hong Wang

2017-01-01

In bacteria, the metabolism of branched-chain amino acids (BCAAs) is tightly associated with branched-chain fatty acids (BCFAs) synthetic pathways. Although previous studies have reported on BCFAs biosynthesis, more detailed associations between BCAAs metabolism and BCFAs biosynthesis remain to be addressed. In this study, we deleted the ilvC gene, which encodes ketol-acid reductoisomerase in the BCAAs synthetic pathway, from the Xanthomonas campestris pv. campestris (Xcc) genome. We characte...

The apo structure of sucrose hydrolase from Xanthomonas campestris pv. campestris shows an open active-site groove

DEFF Research Database (Denmark)

Champion, Elise; Remaud-Simeon, Magali; Skov, Lars Kobberøe

2009-01-01

Glycoside hydrolase family 13 (GH-13) mainly contains starch-degrading or starch-modifying enzymes. Sucrose hydrolases utilize sucrose instead of amylose as the primary glucosyl donor. Here, the catalytic properties and X-ray structure of sucrose hydrolase from Xanthomonas campestris pv. campestris...... of GH-13. Comparisons with structures of the highly similar sucrose hydrolase from X. axonopodis pv. glycines most notably showed that residues Arg516 and Asp138, which form a salt bridge in the X. axonopodis sucrose complex and define part of the subsite -1 glucosyl-binding determinants...

Virulence of Xanthomonas translucens pv. poae Isolated from Poa annua

Directory of Open Access Journals (Sweden)

Arielle Chaves

2013-03-01

Full Text Available Bacterial wilt is a vascular wilt disease caused by Xanthomonas translucens pv. poae that infects Poa annua, a grass that is commonly found on golf course greens throughout the world. Bacterial wilt causes symptoms of etiolation, wilting, and foliar necrosis. The damage is most prevalent during the summer and the pathogen can kill turf under conditions optimal for disease development. Fifteen isolates of X. translucens pv. poae were collected from northern regions in the United States and tested for virulence against P. annua. All 15 isolates were pathogenic on P. annua, but demonstrated variable levels of virulence when inoculated onto P. annua under greenhouse conditions. The isolates were divided into two virulence groups. The first group containing four isolates generally resulted in less than 40% mortality following inoculation. The second group, containing the other eleven isolates, produced between 90 and 100% mortality following inoculation. These results suggest that differences in the virulence of bacterial populations present on a golf course may result in more or less severe amounts of observed disease.

A specific interdomain interaction preserves the structural and binding properties of the ModA protein from the phytopathogen Xanthomonas citri domain interaction and transport in ModA.

Science.gov (United States)

Santacruz-Perez, Carolina; Pegos, Vanessa Rodrigues; Honorato, Rodrigo V; Verli, Hugo; Lindahl, Erik; Barbosa, João Alexandre Ribeiro Gonçalves; Balan, Andrea

2013-11-01

The periplasmic-binding proteins in ATP-binding cassette systems (ABC Transporters) are responsible for the capture and delivery of ligands to their specific transporters, triggering a series of ATP-driven conformational changes that leads to the transport of the ligand. Structurally consisting of two lobes, the proteins change conformation after interaction with the ligand. The structure of the molybdate-binding protein (ModA) from Xanthomonas citri, bound to molybdate, was previously solved by our group and an interdomain interaction, mediated by a salt bridge between K127 and D59, apparently supports the binding properties and keeps the domains closed. To determinate the importance of this interaction, we built two ModA mutants, K127S and D59A, and analysed their functional and structural properties. Based on a set of spectroscopic experiments, crystallisation trials, structure determination and molecular dynamics (MD) simulations, we showed that the salt bridge is essential to maintain the structure and binding properties. Additionally, the MD simulations revealed that this mutant adopted a more compact structure that packed down the ligand-binding pocket. From the closed bound to open structure, the positioning of the helices forming the dipole and the salt bridge are essential to induce an intermediate state. Copyright © 2013 Elsevier Inc. All rights reserved.

Mutual intelligibility between closely related language in Europe.

NARCIS (Netherlands)

Gooskens, Charlotte; van Heuven, Vincent; Golubovic, Jelena; Schüppert, Anja; Swarte, Femke; Voigt, Stefanie

2018-01-01

By means of a large-scale web-based investigation, we established the degree of mutual intelligibility of 16 closely related spoken languages within the Germanic, Slavic and Romance language families in Europe. We first present the results of a selection of 1833 listeners representing the mutual

29 CFR 541.703 - Directly and closely related.

Science.gov (United States)

2010-07-01

... transit, is performing exempt work. If the employee also spends part of the day taking telephone orders... employee's exempt work cannot be performed properly. Work “directly and closely related” to the performance... related to exempt work: (1) Keeping time, production or sales records for subordinates is work directly...

Detection of bacteriocins produced by plant pathogenic bacteria from the general Erwinia, Pseudomonas and Xanthomonas

International Nuclear Information System (INIS)

Biagi, C.M.R. de

1992-01-01

Detection of bacteriocin production was studied under distinct conditions using strains of plant pathogenic bacteria from the genera Erwinia, Pseudomonas and Xanthomonas. 58.06%, 79.31% and 40.00% of producing strains were found respectively in the three groups of bacteria using the 523 medium which was the best for the detection of bacteriocin production. Increasing agar concentrations added to the medium up to 1,5% improved the detection. The amount of medium added to the Petri dishes did not affect bacteriocin production. The longest incubation time (72 h.) improved the detection of haloes production. Ultra-violet irradiation in low dosages seems to improve the visualization of haloes production but this is dependent on the tested strains. (author)

Mutual intelligibility between closely related languages in Europe

NARCIS (Netherlands)

Gooskens, C.; Heuven, van V.J.J.P.; Golubović, J.; Schüppert, A.; Swarte, F.; Voigt, S.

2017-01-01

By means of a large-scale web-based investigation, we established the degree of mutual intelligibility of 16 closely related spoken languages within the Germanic, Slavic and Romance language families in Europe. We first present the results of a selection of 1833 listeners representing the mutual

Host range of Xanthomonas sp., causal agent of the false red stripe of sugarcane, among grasses

OpenAIRE

Mantovani, Elaine Spindola; Marini, Danyelle Cristine; Giglioti, Éder Antônio

2006-01-01

Falsa estria vermelha (FEV), uma nova doença causada por Xanthomonas sp., é diferente diferente de todas as outras doenças já descritas em cana-de-açúcar. Ela está distribuída por toda as principais regiões canavieiras do centro-sul do Brasil, mas ainda não foi detectada no norte e nordeste do Brasil nem em qualquer outro país. O presente estudo determinou a gama de culturas e plantas daninhas hospedeiras da bactéria dentre espécies pertencentes às gramíneas, através de inoculação por injeção...

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice

OpenAIRE

Tayi, Lavanya; Maku, Roshan V.; Patel, Hitendra Kumar; Sonti, Ramesh V.

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bi...

Development of a Species-specific PCR Assay for Three Xanthomonas Species, Causing Bulb and Flower Diseases, Based on Their Genome Sequences

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Chang-Gi Back

2015-09-01

Full Text Available In this study, we developed a species-specific PCR assay for rapid and accurate detection of three Xanthomonas species, X. axonopodis pv. poinsettiicola (XAP, X. hyacinthi (XH and X. campestris pv. zantedeschiae (XCZ, based on their draft genome sequences. XAP, XH and XCZ genomes consist of single chromosomes that contain 5,221, 4,395 and 7,986 protein coding genes, respectively. Species-specific primers were designed from variable regions of the draft genome sequence data and assessed by a PCR-based detection method. These primers were also tested for specificity against 17 allied Xanthomonas species as well as against the host DNA and the microbial community of the host surface. Three primer sets were found to be very specific and no amplification product was obtained with the host DNA and the microbial community of the host surface. In addition, a detection limit of 1 pg/μl per PCR reaction was detected when these primer sets were used to amplify corresponding bacterial DNAs. Therefore, these primer sets and the developed species-specific PCR assay represent a valuable, sensitive, and rapid diagnostic tool that can be used to detect three specific pathogens at early stages of infection and may help control diseases.

Reaction of detached leaves of different varieties of sweet orange (Citrus sinensis L. Osbeck) to inoculation with Xanthomonas citri subsp. citri (ex Hasse) Gabriel et al.

Science.gov (United States)

Asiatic citrus canker (ACC) (caused by Xanthomonas citri subsp citri, Xcc) is a major disease of citrus in wet tropical and subtropical production regions. Screening for resistance is important to breeding programs. The objective of this study was to evaluate a detached leaf method to compare nine d...

Návrh a testování specifických primerů pro detekci karanténní bakterie Xanthomonas vesicatoria

Czech Academy of Sciences Publication Activity Database

Beran, Pavel; Mráz, Ivan

2011-01-01

Roč. 12, - (2011), s. 205-208 ISSN 0139-6013. [Aktuální poznatky v pěstování, šlechtění, ochraně rostlin a zpracování produktů. Brno, 15.11.2011-16.11.2011] R&D Projects: GA MZe QH71229 Institutional research plan: CEZ:AV0Z50510513 Keywords : Xanthomonas vesicatoria * PCR * detection * primers Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection

12 CFR 225.131 - Activities closely related to banking.

Science.gov (United States)

2010-01-01

...; operation and management of a trust department; international banking; foreign exchange transactions... specialized lending provisions; marketing operations, including research, market development and advertising... Holding Companies Interpretations § 225.131 Activities closely related to banking. (a) Bank management...

Identification and characterisation of Xanthomonas campestris pv

African Journals Online (AJOL)

Ednar Wulff

2013-02-06

Feb 6, 2013 ... Race type differentiation tests revealed the Xcc strains from Mozambique as members of race 1. ... However, differentiation of Xcc strains from closely related pathovars that are pathogenic on ..... village leadership, extension service officers and the cabbage growers in the survey area. REFERENCES.

Close relatives find meaning to cope with cancer diagnosis and treatment of family members.

Science.gov (United States)

Feyh, Janelle M; Levine, Ellen G; Clay, Karine

2012-12-01

Pediatric palliative care has recently become a priority in the health care field and is implemented at the time of diagnosis rather than days or weeks before the child's death. Social constructivism theory in which humans generate meaning from their experiences was utilized as a general framework to determine the impact of pediatric palliative care on close relatives. The purpose of this grounded theory study was to generate a substantive theory that explains how close relatives such as grandparents, aunts, and uncles of a child with cancer experience palliative care. The participants of the study included close relatives of children in palliative care. Semistructured interviews and journaling were used to collect data. Initial, focused, and axial coding procedures were used to manage the data and a content analysis of the textual data was performed. Findings from the data suggested a process of finding meaning which helps close relatives to let go of what they cannot control while holding on to what they can control. Social change implications of this study may include improving health care programming for close relatives utilizing supportive-expressive measures. This programming may promote mental health of the close relatives who will learn to deal with their adjustment difficulties and improve their coping skills.

Close pairs of relative equilibria for identical point vortices

DEFF Research Database (Denmark)

Dirksen, Tobias; Aref, Hassan

2011-01-01

Numerical solution of the classical problem of relative equilibria for identical point vortices on the unbounded plane reveals configurations that are very close to the analytically known, centered, symmetrically arranged, nested equilateral triangles. New numerical solutions of this kind are fou...

Inoculação e sobrevivência de Xanthomonas vesicatoria em sementes de tomateiro Inoculation and survival of Xanthomonas vesicatoria on tomato seeds

Directory of Open Access Journals (Sweden)

Fábio Mathias Corrêa

2008-02-01

Full Text Available Para avaliar o efeito de métodos de inocuação de Xanthomonas vesicatoria (Doidge (9 em sementes de tomate sobre a qualidade da semente e transmissão da fitobactéria compararam-se os tratamentos: 1 inoculação a vácuo com suspensão de células de X. vesicatoria em STP (0,005M, pH 7,4 e NaCl 0,85%; 2 imersão por 24 horas em suspensão de células de X. vesicatoria em STP; 3 vácuo em solução STP; 4 imersão por 24 horas em STP; 5 imersão por 5 min. em álcool etílico e 6 semente original. As avaliações foram realizadas por testes de germinação e isolamentos em meio Nutriente Agar Modificado (NAM aos 1, 15, 30 e 45 dias após aplicação dos tratamentos. Em seguida, avaliou-se o efeito da umidade (4% e 8% e o armazenamento das sementes inoculadas e variações de umidade antes da realização dos testes sobre a sobrevivência e recuperação de X. vesicatoria. Os métodos de inoculação testados podem ser utilizados em trabalhos de rotina, porém, as sementes devem ser utilizadas até 30 dias após a inoculação a partir de quando ocorre uma redução acentuada na taxa de recuperação da fitobactéria. A umidade das sementes interfere na sobrevivência e na transmissão de X. vesicatoria pelas sementes de tomate.The efficiency of six methods of Xanthomonas vesicatoria (Doidge (9 inoculation on tomato seeds, and their effects on seed quality were tested : 1 vacuum inoculation with X. vesicatoria cell suspension in PB (0.005M, pH 7.4 e NaCl 0.85%; 2 immersion for 24 hours in with X. vesicatoria cell suspension and PB. 3 vacuum and saline solution in phosphate buffer; 4 immersion in PB for 24 hours; 5 seeds + ethanol; 6 control. Evaluations were performed for germination test and isolation in Modified Agar Nutrient (NAM at 1, 15, 30 and 45 days after treatments imposition. The moisture effect on the transmission of X. vesicatoria seeds inoculated under vacuum, followed or not by air drying at 30±1 ºC, until 4% and 8% moisture

Brain death: close relatives' use of imagery as a descriptor of experience.

Science.gov (United States)

Frid, Ingvar; Haljamäe, Hengo; Ohlén, Joakim; Bergbom, Ingegerd

2007-04-01

This paper is a report of a study to explore the use of imagery to describe the experience of confronting brain death in a close relative. The brain death of a loved one has been described as an extremely difficult experience for close relatives, evoking feelings of anger, emotional pain, disbelief, guilt and suffering. It can also be difficult for relatives to distinguish brain death from the state of coma and thus difficult to apprehend information about the diagnosis. Narrative theory and a hermeneutic phenomenological method guided the interpretation of 17 narratives from close relatives of brain dead patients. All narratives were scrutinized for experiences of brain death. Data were primarily collected in 1999. The primary analysis related to close relatives' experience of brain death in a loved one. A secondary analysis of the imagery they used to describe their experience was carried out in 2003. Six categories of imagery used to describe the experience of confronting a diagnosis of brain death in a loved one emerged: chaotic unreality; inner collapse; sense of forlornness; clinging to the hope of survival; reconciliation with the reality of death; receiving care which gives comfort. Participants also identified two pairs of dimensions to describe their feelings about the relationship between their brain dead relative's body and personhood: presence-absence and divisibility-indivisibility. Being confronted with brain death meant entering into the anteroom of death, facing a loved one who is 'living-dead', and experiencing a chaotic drama of suffering. It is very important for members of the intensive care unit team to recognize, face and respond to these relatives' chaotic experiences, which cause them to need affirmation, comfort and caring. Relatives' use of imagery could be the starting point for a caring conversation about their experiences, either in conversations at the time of the death or when relatives are contacted in a later follow-up.

Transcriptome-based differentiation of closely-related Miscanthus lines.

Directory of Open Access Journals (Sweden)

Philippe Chouvarine

Full Text Available BACKGROUND: Distinguishing between individuals is critical to those conducting animal/plant breeding, food safety/quality research, diagnostic and clinical testing, and evolutionary biology studies. Classical genetic identification studies are based on marker polymorphisms, but polymorphism-based techniques are time and labor intensive and often cannot distinguish between closely related individuals. Illumina sequencing technologies provide the detailed sequence data required for rapid and efficient differentiation of related species, lines/cultivars, and individuals in a cost-effective manner. Here we describe the use of Illumina high-throughput exome sequencing, coupled with SNP mapping, as a rapid means of distinguishing between related cultivars of the lignocellulosic bioenergy crop giant miscanthus (Miscanthus × giganteus. We provide the first exome sequence database for Miscanthus species complete with Gene Ontology (GO functional annotations. RESULTS: A SNP comparative analysis of rhizome-derived cDNA sequences was successfully utilized to distinguish three Miscanthus × giganteus cultivars from each other and from other Miscanthus species. Moreover, the resulting phylogenetic tree generated from SNP frequency data parallels the known breeding history of the plants examined. Some of the giant miscanthus plants exhibit considerable sequence divergence. CONCLUSIONS: Here we describe an analysis of Miscanthus in which high-throughput exome sequencing was utilized to differentiate between closely related genotypes despite the current lack of a reference genome sequence. We functionally annotated the exome sequences and provide resources to support Miscanthus systems biology. In addition, we demonstrate the use of the commercial high-performance cloud computing to do computational GO annotation.

12 CFR 225.129 - Activities closely related to banking.

Science.gov (United States)

2010-01-01

... competitive advantage over firms competing with other holding company affiliates. To reduce the possibility... Board's amendment of § 225.4(a), which adds courier services to the list of closely related activities... generally in the provision of transportation services. During the course of the Board's proceedings...

31 CFR 515.561 - Persons visiting close relatives in Cuba.

Science.gov (United States)

2010-07-01

... Cuba. 515.561 Section 515.561 Money and Finance: Treasury Regulations Relating to Money and Finance... Cuba. (a) General license. (1) Persons subject to the jurisdiction of the United States and persons... close relative, as defined in § 515.339 of this part, who is a national of Cuba, as defined in § 515.302...

Transcriptional responses of Italian ryegrass during interaction with Xanthomonas translucens pv. graminis reveal novel candidate genes for bacterial wilt resistance

DEFF Research Database (Denmark)

Wichmann, Fabienne; Asp, Torben; Widmer, Franko

2011-01-01

Xanthomonas translucens pv. graminis (Xtg) causes bacterial wilt, a severe disease of forage grasses such as Italian ryegrass (Lolium multiflorum Lam.). In order to gain a more detailed understanding of the genetic control of resistance mechanisms and to provide prerequisites for marker assisted...... selection, the partial transcriptomes of two Italian ryegrass genotypes, one resistant and one susceptible to bacterial wilt were compared at four time points after Xtg infection. A cDNA microarray developed from a perennial ryegrass (Lolium perenne) expressed sequence tag set consisting of 9,990 unique...

Characterization of hypersensitive resistance to bacterial spot race T3 (Xanthomonas perforans) from tomato accession PI 128216.

Science.gov (United States)

Robbins, Matthew D; Darrigues, Audrey; Sim, Sung-Chur; Masud, Mohammed Abu Taher; Francis, David M

2009-09-01

Bacterial spot of tomato is caused by four species of Xanthomonas. The accession PI 128216 (Solanum pimpinellifolium) displays a hypersensitive reaction (HR) to race T3 strains (predominantely Xanthomonas perforans). We developed an inbred backcross (IBC) population (BC(2)S(5), 178 families) derived from PI 128216 and OH88119 (S. lycopersicum) as the susceptible recurrent parent for simultaneous introgression and genetic analysis of the HR response. These IBC families were evaluated in the greenhouse for HR to race T3 strain Xcv761. The IBC population was genotyped with molecular markers distributed throughout the genome in order to identify candidate loci conferring resistance. We treated the IBC population as a hypothesis forming generation to guide validation in subsequent crosses. Nonparametric analysis identified an association between HR and markers clustered on chromosome 11 (P P > 0.002). Further analysis of the IBC population suggested that markers on chromosome 6 and 11 failed to assort independently, a phenomenon known as gametic phase disequilibrium. Therefore, to validate marker-trait linkages, resistant IBC plants were crossed with OH88119 and BC(3)F(2) progeny were evaluated for HR in the greenhouse. In these subsequent populations, the HR response was associated with the chromosome 11 markers (P 0.25). Independent F(2) families were developed by crossing resistant IBC lines to OH8245, OH88119, and OH7530. These populations were genotyped, organized into classes based on chromosome 11 markers, and evaluated for resistance in the field. The PI 128216 locus on chromosome 11 provided resistance that was dependent on gene dosage and genetic background. These results define a single locus, Rx-4, from PI 128216, which provides resistance to bacterial spot race T3, has additive gene action, and is located on chromosome 11.

Unusual Growth Phase and Oxygen Tension Regulation of Oxidative Stress Protection Enzymes, Catalase and Superoxide Dismutase, in the Phytopathogen Xanthomonas oryzae pv. oryzae

OpenAIRE

Chamnongpol, S.; Mongkolsuk, S.; Vattanaviboon, P.; Fuangthong, M.

1995-01-01

The enzymes catalase and superoxide dismutase play major roles in protecting phytopathogenic bacteria from oxidative stress. In Xanthomonas species, these enzymes are regulated by both growth phase and oxygen tension. The highest enzyme levels were detected within 1 h of growth. Continued growth resulted in a decline of both enzyme activities. High oxygen tension was an inducing signal for both enzyme activities. An 80,000-Da monofunctional catalase and a manganese superoxide dismutase were t...

Antagonism of yeasts to Xanthomonas campestris pv. campestris on cabbage phylloplane in field Antagonismo de leveduras a Xanthomonas campestris pv. campestris no filoplano de repolho em condições de campo

Directory of Open Access Journals (Sweden)

Sayonara M.P. Assis

1999-07-01

Full Text Available Twenty yeast isolates, obtained from cabbage phylloplane, were evaluated for antagonistic activity against Xanthomonas campestris pv. campestris, in field. Plants of cabbage cv. Midori were pulverized simultaneously with suspensions of antagonists and pathogen. After 10 days, plants were evaluated through percentage of foliar area with lesions. Percentage of disease severity reduction (DSR% was also calculated. Yeast isolates LR32, LR42 and LR19 showed, respectively, 72, 75 and 79% of DSR. These antagonists were tested in seven different application periods in relation to pathogen inoculation (T1=4 d before; T2=simultaneously; T3=4 d after; T4=4 d before + simultaneously; T5=4 d after + simultaneously; T6=4 d before + 4 d after; T7=4 d before + simultaneously + 4 d after. The highest DSRs were showed by LR42 (71%, LR42 (67%, LR35 (69% and LR19 (68% in the treatments T7, T4, T5 and T6, which significantly differed from the others. The same yeast antagonists were also tested for black rot control using different cabbage cultivars (Fuyutoyo, Master-325, Matsukaze, Midori, Sekai I and Red Winner. The DSRs varied from 58 to 61%, and there was no significant difference among cultivars.Vinte isolados de leveduras, obtidos a partir do filoplano de repolho foram avaliados pela atividade antagônica contra Xanthomonas campestris pv. campestris, em condições de campo. Plantas de repolho cv. Midori foram pulverizadas simultaneamente com suspensões do antagonista e do patógeno. Após 10 dias, as plantas foram avaliadas através da porcentagem de área foliar infectada. A porcentagem de redução da severidade da doença (DSR%, também foi calculada. Os isolados de leveduras LR32, LR42 e LR19 apresentaram, respectivamente, 72, 75 e 79% de DSR. Estes isolados foram testados em sete diferentes períodos de aplicação dos antagonistas em relação a inoculação do patógeno. (T1=4d antes; T2=simultaneamente; T3=4 d após; T4=4 d antes + simultaneamente; T5

Detecting Horizontal Gene Transfer between Closely Related Taxa.

Directory of Open Access Journals (Sweden)

Orit Adato

2015-10-01

Full Text Available Horizontal gene transfer (HGT, the transfer of genetic material between organisms, is crucial for genetic innovation and the evolution of genome architecture. Existing HGT detection algorithms rely on a strong phylogenetic signal distinguishing the transferred sequence from ancestral (vertically derived genes in its recipient genome. Detecting HGT between closely related species or strains is challenging, as the phylogenetic signal is usually weak and the nucleotide composition is normally nearly identical. Nevertheless, there is a great importance in detecting HGT between congeneric species or strains, especially in clinical microbiology, where understanding the emergence of new virulent and drug-resistant strains is crucial, and often time-sensitive. We developed a novel, self-contained technique named Near HGT, based on the synteny index, to measure the divergence of a gene from its native genomic environment and used it to identify candidate HGT events between closely related strains. The method confirms candidate transferred genes based on the constant relative mutability (CRM. Using CRM, the algorithm assigns a confidence score based on "unusual" sequence divergence. A gene exhibiting exceptional deviations according to both synteny and mutability criteria, is considered a validated HGT product. We first employed the technique to a set of three E. coli strains and detected several highly probable horizontally acquired genes. We then compared the method to existing HGT detection tools using a larger strain data set. When combined with additional approaches our new algorithm provides richer picture and brings us closer to the goal of detecting all newly acquired genes in a particular strain.

Relationship of Dyadic Closeness with Work-Related Stress: A Daily Diary Study

Science.gov (United States)

Lavee, Yoav; Ben-Ari, Adital

2007-01-01

We examined the association between work-related stress of both spouses and daily fluctuations in their affective states and dyadic closeness. Daily diary data from 169 Israeli dual-earner couples were analyzed using multilevel modeling. The findings indicate that work stress has no direct effect on dyadic closeness but rather is mediated by the…

Use of Wild Relatives and Closely Related Species to Adapt Common Bean to Climate Change

Directory of Open Access Journals (Sweden)

James D. Kelly

2013-05-01

Full Text Available Common bean (Phaseolus vulgaris L. is an important legume crop worldwide. However, abiotic and biotic stress limits bean yields to <600 kg ha−1 in low-income countries. Current low yields result in food insecurity, while demands for increased yields to match the rate of population growth combined with the threat of climate change are significant. Novel and significant advances in genetic improvement using untapped genetic diversity available in crop wild relatives and closely related species must be further explored. A meeting was organized by the Global Crop Diversity Trust to consider strategies for common bean improvement. This review resulted from that meeting and considers our current understanding of the genetic resources available for common bean improvement and the progress that has been achieved thus far through introgression of genetic diversity from wild relatives of common bean, and from closely related species, including: P. acutifolius, P. coccineus, P. costaricensis and P. dumosus. Newly developed genomic tools and their potential applications are presented. A broad outline of research for use of these genetic resources for common bean improvement in a ten-year multi-disciplinary effort is presented.

Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

2017-12-01

The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

Interaction of the phage-xanthomonas campestris (Pammel) Dowson at the eletronic microscopy level, Virazole effect and radioautographic study of the phage action on the host

International Nuclear Information System (INIS)

Sittolin, I.M.

1982-04-01

A bacteriophage from the cabbage tissue infected with Xanthomonas campestris is described. The infection process is studied through a negative staining technique (PTA) and ultrathin section. The effect of Virazole, an antivirus agent, is tested. Radioautography showed that the phage presented a reasonable domain on the bacterial host genome since the beginning of the treatment. Sorological reactions indicated the induction of specific antibodies for the phage. (M.A.C.) [pt

eShadow: A tool for comparing closely related sequences

Energy Technology Data Exchange (ETDEWEB)

Ovcharenko, Ivan; Boffelli, Dario; Loots, Gabriela G.

2004-01-15

Primate sequence comparisons are difficult to interpret due to the high degree of sequence similarity shared between such closely related species. Recently, a novel method, phylogenetic shadowing, has been pioneered for predicting functional elements in the human genome through the analysis of multiple primate sequence alignments. We have expanded this theoretical approach to create a computational tool, eShadow, for the identification of elements under selective pressure in multiple sequence alignments of closely related genomes, such as in comparisons of human to primate or mouse to rat DNA. This tool integrates two different statistical methods and allows for the dynamic visualization of the resulting conservation profile. eShadow also includes a versatile optimization module capable of training the underlying Hidden Markov Model to differentially predict functional sequences. This module grants the tool high flexibility in the analysis of multiple sequence alignments and in comparing sequences with different divergence rates. Here, we describe the eShadow comparative tool and its potential uses for analyzing both multiple nucleotide and protein alignments to predict putative functional elements. The eShadow tool is publicly available at http://eshadow.dcode.org/

MultiLocus Sequence Analysis- and Amplified Fragment Length Polymorphism-based characterization of xanthomonads associated with bacterial spot of tomato and pepper and their relatedness to Xanthomonas species.

Science.gov (United States)

Hamza, A A; Robene-Soustrade, I; Jouen, E; Lefeuvre, P; Chiroleu, F; Fisher-Le Saux, M; Gagnevin, L; Pruvost, O

2012-05-01

MultiLocus Sequence Analysis (MLSA) and Amplified Fragment Length Polymorphism (AFLP) were used to measure the genetic relatedness of a comprehensive collection of xanthomonads pathogenic to solaneous hosts to Xanthomonas species. The MLSA scheme was based on partial sequences of four housekeeping genes (atpD, dnaK, efp and gyrB). Globally, MLSA data unambiguously identified strains causing bacterial spot of tomato and pepper at the species level and was consistent with AFLP data. Genetic distances derived from both techniques showed a close relatedness of (i) X. euvesicatoria, X. perforans and X. alfalfae and (ii) X. gardneri and X. cynarae. Maximum likelihood tree topologies derived from each gene portion and the concatenated data set for species in the X. campestris 16S rRNA core (i.e. the species cluster comprising all strains causing bacterial spot of tomato and pepper) were not congruent, consistent with the detection of several putative recombination events in our data sets by several recombination search algorithms. One recombinant region in atpD was identified in most strains of X. euvesicatoria including the type strain. Copyright © 2012 Elsevier GmbH. All rights reserved.

Impact of Engineered Nanoparticles on Virulence of Xanthomonas oryzae pv oryzae and on Rice Sensitivity at its Infection

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Giuliano Degrassi

2014-12-01

Full Text Available The present work of nanocotoxicity wants to propose a new plant model starting from the rice plant. The model takes into consideration the impact of engineered nanoparticles (Ag, Co, Ni, CeO2, Fe3O4, TiO2 on rice plants that were weakened by infections of Xanthomonas oryzae pv oryzae bacteria. The results indicate that some NPs increase the rice sensitivity to the pathogen while others decrease the virulence of the pathogen towards rice. No-enrichment in component metal concentration is detected in above organs of rice, with exception of Ni-NPs treatment. An imbalance of major elements in infected rice crops treated with NPs was investigated.

Screening of gamma radiation-induced pathogen resistance rice lines against Xanthomonas oryzae pv. oryzae

Energy Technology Data Exchange (ETDEWEB)

Lim, Chan Ju; Lee, Ha Yeon; Kim, Woong Bom; Ahmad, Raza; Moon, Jae Sun; Kwon, Suk Yoon [Korea Research Institute of Beoscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Dong Sub [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2010-09-15

Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of M{sub 3}, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In M{sub 4} generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

Convex optimisation approach to constrained fuel optimal control of spacecraft in close relative motion

Science.gov (United States)

Massioni, Paolo; Massari, Mauro

2018-05-01

This paper describes an interesting and powerful approach to the constrained fuel-optimal control of spacecraft in close relative motion. The proposed approach is well suited for problems under linear dynamic equations, therefore perfectly fitting to the case of spacecraft flying in close relative motion. If the solution of the optimisation is approximated as a polynomial with respect to the time variable, then the problem can be approached with a technique developed in the control engineering community, known as "Sum Of Squares" (SOS), and the constraints can be reduced to bounds on the polynomials. Such a technique allows rewriting polynomial bounding problems in the form of convex optimisation problems, at the cost of a certain amount of conservatism. The principles of the techniques are explained and some application related to spacecraft flying in close relative motion are shown.

Extracted facial feature of racial closely related faces

Science.gov (United States)

Liewchavalit, Chalothorn; Akiba, Masakazu; Kanno, Tsuneo; Nagao, Tomoharu

2010-02-01

Human faces contain a lot of demographic information such as identity, gender, age, race and emotion. Human being can perceive these pieces of information and use it as an important clue in social interaction with other people. Race perception is considered the most delicacy and sensitive parts of face perception. There are many research concerning image-base race recognition, but most of them are focus on major race group such as Caucasoid, Negroid and Mongoloid. This paper focuses on how people classify race of the racial closely related group. As a sample of racial closely related group, we choose Japanese and Thai face to represents difference between Northern and Southern Mongoloid. Three psychological experiment was performed to study the strategies of face perception on race classification. As a result of psychological experiment, it can be suggested that race perception is an ability that can be learn. Eyes and eyebrows are the most attention point and eyes is a significant factor in race perception. The Principal Component Analysis (PCA) was performed to extract facial features of sample race group. Extracted race features of texture and shape were used to synthesize faces. As the result, it can be suggested that racial feature is rely on detailed texture rather than shape feature. This research is a indispensable important fundamental research on the race perception which are essential in the establishment of human-like race recognition system.

Closed-form summations of Dowker's and related trigonometric sums

Science.gov (United States)

Cvijović, Djurdje; Srivastava, H. M.

2012-09-01

Through a unified and relatively simple approach which uses complex contour integrals, particularly convenient integration contours and calculus of residues, closed-form summation formulas for 12 very general families of trigonometric sums are deduced. One of them is a family of cosecant sums which was first summed in closed form in a series of papers by Dowker (1987 Phys. Rev. D 36 3095-101 1989 J. Math. Phys. 30 770-3 1992 J. Phys. A: Math. Gen. 25 2641-8), whose method has inspired our work in this area. All of the formulas derived here involve the higher-order Bernoulli polynomials. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker's 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’.

Pathotype profile of Xanthomonas oryzae pv. oryzae isolates from North Sumatera

Science.gov (United States)

Noer, Z.; Hasanuddin; Lisnawita; Suryanto, D.

2018-02-01

The Bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most important diseases and has caused crop failure in rice crops. This pathogen infects the leaves in all plant growth phases. The purpose of this study is to investigation 10 Xoo isolates pathotype obtained from North Sumatra based on their interactions with 10 near-isogenic rice lines (NIL) of IRRI. The results showed that there are 6 pathotypes of virulence in North Sumatra, they are; pathotype I with incompatible interaction to all Xa genes, pathotype II with compatible interaction to Xa1 and Xa3 genes, while it has incompatible interaction to other genes, pathotype III with compatible interaction to Xa1, Xa5, Xa7, Xa8, Xa10 and Xa11 genes, but it has incompatible interaction to other genes, pathotype IV with compatible interaction to all Xa genes, pathotype V with compatible interaction to Xa1 gene and incompatible interaction to other genes, and pathotype VI with compatible interaction to Xa3 gene and incompatible interaction to other genes. Based on the resistant genes in each individual Xa2, Xa4, and Xa21 genes are the combination of Xa genes which are most suitable for use in the development of rice cultivars in North Sumatra.

Novel Rosaceae plant elicitor peptides as sustainable tools to control Xanthomonas arboricola pv. pruni in Prunus spp.

Science.gov (United States)

Ruiz, Cristina; Nadal, Anna; Montesinos, Emilio; Pla, Maria

2018-02-01

Fruit crops are regarded as important health promoters and constitute a major part of global agricultural production, and Rosaceae species are of high economic impact. Their culture is threatened by bacterial diseases, whose control is based on preventative treatments using compounds of limited efficacy and negative environmental impact. One of the most economically relevant examples is the pathogen Xanthomonas arboricola pv. pruni (Xap) affecting Prunus spp. The plant immune response against pathogens can be triggered and amplified by plant elicitor peptides (Peps), perceived by specific receptors (PEPRs). Although they have been described in various angiosperms, scarce information is available on Rosaceae species. Here, we identified the Pep precursor (PROPEP), Pep and PEPR orthologues of 10 Rosaceae species and confirmed the presence of the Pep/PEPR system in this family. We showed the perception and elicitor activity of Rosaceae Peps using the Prunus-Xap pathosystem as proof-of-concept. Treatment with nanomolar doses of Peps induced the corresponding PROPEP and a set of defence-related genes in Prunus leaves, and enhanced resistance against Xap. Peps from the same species had the highest efficiencies. Rosaceae Peps could potentially be used to develop natural, targeted and environmentally friendly strategies to enhance the resistance of Prunus species against biotic attackers. © 2017 BSPP AND JOHN WILEY & SONS LTD.

Bioconversion from crude glycerin by Xanthomonas campestris 2103: xanthan production and characterization

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L. V. Brandão

2013-12-01

Full Text Available The production and rheological properties of xanthan gum from crude glycerin fermentation, a primary by-product of the biodiesel industry with environmental and health risks, were evaluated. Batch fermentations (28 °C/250 rpm /120 h were carried out using crude glycerin, 0.01% urea and 0.1% KH2PO4, (% w/v, and compared to a sucrose control under the same operational conditions, using Xanthomonas campestris strain 2103 isolate from Brazil. Its maximal production by crude glycerin fermentation was 7.23±0.1 g·L-1 at 120 h, with an apparent viscosity of 642.57 mPa·s, (2 % w/v, 25 °C, 25 s-1, 70% and 30% higher than from sucrose fermentation, respectively. Its molecular weight varied from 28.2 to 36.2×10(6 Da. The Ostwald-de-Waele model parameters (K and n indicated a pseudoplastic behavior at all concentrations (0.5 to 2.0 %, w/v and temperatures (25-85 °C, while its consistency index indicated promising rheological properties for drilling fluid applications. Therefore, crude glycerin has potential as a cost-effective and alternative substrate for non-food grade xanthan production.

Anxiety, depression and PTSD-related symptoms in spouses and close relatives of burn survivors: When the supporter needs to be supported.

Science.gov (United States)

Bond, Suzie; Gourlay, Catherine; Desjardins, Alexandra; Bodson-Clermont, Paule; Boucher, Marie-Ève

2017-05-01

The aim of the study was to assess the prevalence of anxiety, depression and PTSD-related symptoms reported by spouses and close relatives of adult burn survivors. Potential associations between these symptoms and variables such as the severity of the burn were also explored. Participants were spouses (n=31) and close relatives (n=25) of hospitalized patients with acute burns. Anxiety and depression symptoms were assessed by the Hospital Distress Anxiety and Depression Scale and PTSD-related symptoms by the Modified PTSD Symptom Scale at both admission to and discharge from the burn unit. At admission, 77% of spouses and 56% of close relatives of burn patients reported anxiety, depression or PTSD-related symptoms in the clinical range. While spouses had higher scores than close relatives on symptom measures, significant differences were only established for anxiety symptoms (p<.02). A significant effect was found for gender, with women reporting more anxiety (p=.01) and depression (p=.02) symptoms than men. Results also showed a main effect for time, with anxiety (p<.0001), depression (p<.0001) and PTSD-related (p<.0001) symptoms being higher at admission than at discharge. Variables associated with the index patient, such as total body surface area burned, length of stay, number of ventilated days, facial burns, or level of care at admission, were not associated with outcome measures. Spouses and close relatives of burn survivors showed high levels of psychological distress in the first few days following admission, and more than a quarter still reported symptoms in the clinical range at discharge. Our analysis points to the need to offer psychological support and guidance to family members so that they can in turn provide effective support to the burn survivor. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Evolutionary history of the plant pathogenic bacterium Xanthomonas axonopodis.

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Nadia Mhedbi-Hajri

Full Text Available Deciphering mechanisms shaping bacterial diversity should help to build tools to predict the emergence of infectious diseases. Xanthomonads are plant pathogenic bacteria found worldwide. Xanthomonas axonopodis is a genetically heterogeneous species clustering, into six groups, strains that are collectively pathogenic on a large number of plants. However, each strain displays a narrow host range. We address the question of the nature of the evolutionary processes--geographical and ecological speciation--that shaped this diversity. We assembled a large collection of X. axonopodis strains that were isolated over a long period, over continents, and from various hosts. Based on the sequence analysis of seven housekeeping genes, we found that recombination occurred as frequently as point mutation in the evolutionary history of X. axonopodis. However, the impact of recombination was about three times greater than the impact of mutation on the diversity observed in the whole dataset. We then reconstructed the clonal genealogy of the strains using coalescent and genealogy approaches and we studied the diversification of the pathogen using a model of divergence with migration. The suggested scenario involves a first step of generalist diversification that spanned over the last 25,000 years. A second step of ecology-driven specialization occurred during the past two centuries. Eventually, secondary contacts between host-specialized strains probably occurred as a result of agricultural development and intensification, allowing genetic exchanges of virulence-associated genes. These transfers may have favored the emergence of novel pathotypes. Finally, we argue that the largest ecological entity within X. axonopodis is the pathovar.

OxyR-regulated catalase CatB promotes the virulence in rice via detoxifying hydrogen peroxide in Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Yu, Chao; Wang, Nu; Wu, Maosen; Tian, Fang; Chen, Huamin; Yang, Fenghuan; Yuan, Xiaochen; Yang, Ching-Hong; He, Chenyang

2016-11-08

To facilitate infection, Xanthomonas oryzae pv. oryzae (Xoo), the bacterial blight pathogen of rice, needs to degrade hydrogen peroxide (H 2 O 2 ) generated by the host defense response via a mechanism that is mediated by the transcriptional regulator OxyR. The catalase (CAT) gene catB has previously been shown to belong to the OxyR regulon in Xoo. However, its expression patterns and function in H 2 O 2 detoxification and bacterial pathogenicity on rice remain to be elucidated. The catB gene encodes a putative catalase and is highly conserved in the sequenced strains of Xanthomonas spp. β-galactosidase analysis and electrophoretic mobility shift assays (EMSA) showed that OxyR positively regulated the transcription of catB by directly binding to its promoter region. The quantitative real-time PCR (qRT-PCR) assays revealed that the expression levels of catB and oxyR were significantly induced by H 2 O 2 . Deletion of catB or oxyR drastically impaired bacterial viability in the presence of extracellular H 2 O 2 and reduced CAT activity, demonstrating that CatB and OxyR contribute to H 2 O 2 detoxification in Xoo. In addition, ΔcatB and ΔoxyR displayed shorter bacterial blight lesions and reduced bacterial growth in rice compared to the wild-type stain, indicating that CatB and OxyR play essential roles in the virulence of Xoo. Transcription of catB is enhanced by OxyR in response to exogenous H 2 O 2 . CatB functions as an active catalase that is required for the full virulence of Xoo in rice.

Closed-form summations of Dowker's and related trigonometric sums

International Nuclear Information System (INIS)

Cvijović, Djurdje; Srivastava, H M

2012-01-01

Through a unified and relatively simple approach which uses complex contour integrals, particularly convenient integration contours and calculus of residues, closed-form summation formulas for 12 very general families of trigonometric sums are deduced. One of them is a family of cosecant sums which was first summed in closed form in a series of papers by Dowker (1987 Phys. Rev. D 36 3095–101; 1989 J. Math. Phys. 30 770–3; 1992 J. Phys. A: Math. Gen. 25 2641–8), whose method has inspired our work in this area. All of the formulas derived here involve the higher-order Bernoulli polynomials. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker's 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’. (paper)

Ectopic accumulation of linalool confers resistance to Xanthomonas citri subsp. citri in transgenic sweet orange plants.

Science.gov (United States)

Shimada, Takehiko; Endo, Tomoko; Rodríguez, Ana; Fujii, Hiroshi; Goto, Shingo; Matsuura, Takakazu; Hojo, Yuko; Ikeda, Yoko; Mori, Izumi C; Fujikawa, Takashi; Peña, Leandro; Omura, Mitsuo

2017-05-01

In order to clarify whether high linalool content in citrus leaves alone induces strong field resistance to citrus canker caused by Xanthomonas citri subsp. citri (Xcc), and to assess whether this trait can be transferred to a citrus type highly sensitive to the bacterium, transgenic 'Hamlin' sweet orange (Citrus sinensis L. Osbeck) plants over-expressing a linalool synthase gene (CuSTS3-1) were generated. Transgenic lines (LIL) with the highest linalool content showed strong resistance to citrus canker when spray inoculated with the bacterium. In LIL plants inoculated by wounding (multiple-needle inoculation), the linalool level was correlated with the repression of the bacterial titer and up-regulation of defense-related genes. The exogenous application of salicylic acid, methyl jasmonate or linalool triggered responses similar to those constitutively induced in LIL plants. The linalool content in Ponkan mandarin leaves was significantly higher than that of leaves from six other representative citrus genotypes with different susceptibilities to Xcc. We propose that linalool-mediated resistance might be unique to citrus tissues accumulating large amounts of volatile organic compounds in oil cells. Linalool might act not only as a direct antibacterial agent, but also as a signal molecule involved in triggering a non-host resistance response against Xcc. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Occurrence of Xanthomonas campestris pv. campestris (Pammel, 1895 Dowson 1939, on Brassicas in Montenegro

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Dragana Radunović

2012-01-01

Full Text Available Brassicas form the most important group of vegetable crops in Montenegro. The cabbage(Brassica oleracea var. capitata is most commonly grown, although other brassicas,particularly kale, Brussels sprout, cauliflower and broccoli, have been increasingly producedsince recently. One of the specialties of vegetable production in Montenegro is growing ofcollard (Brassica oleracea var. acephala, which is the simplest variety of the Brassica oleraceaspecies and in the nearest relation with their wild ancestor – the sylvestris variety.Diseases are the main restrictive factors for successful production of these vegetables.Susceptibility of the cultivars and inadequate control often result in more or less damagedcrops in some plots.Causal agents of brassica diseases, especially bacterial, have not been investigated inMontenegro until 2009. Since the symptoms observed in 2009 were „V” shaped leaf edgenecrosis and black rot of vascular tissue, it was assumed that they were caused by plantpathogenic bacterium Xanthomonas campestris pv. campestris.Samples of the infected plants were collected from different localities in Montenegro.Isolation and identification of the bacterium were performed using laboratory methodsaccording to Schaad (1980, Lelliott and Stead (1987 and Arsenijević (1997. Examinationof chosen bacterial isolates was conducted using both, classical bacteriological methods(examination of their pathogenic, morphological, cultivation and biochemical and physiologicalcharacteristics, and ELISA test.The obtained results confirmed the presence of X.campestris pv. campestris (Pammel,1895 Dowson 1939, on cabbage, kale, broccoli and collard in Montenegro. This is the firstexperimental evidence that collard is the host of X. campestris pv. campestris in Montenegro.

Differences in memory dynamics between two closely related parasitoid wasp species

NARCIS (Netherlands)

Bleeker, M.A.K.; Smid, H.M.; Steidle, J.L.M.; Kruidhof, H.M.; van Loon, J.J.A.; Vet, L.E.M.

2006-01-01

The two closely related parasitoids Cotesia glomerata and C. rubecula (Hymenoptera: Braconidae) coexist in The Netherlands where they occupy slightly different niches. When searching for their caterpillar hosts, they use host plant odours that are released upon feeding by the caterpillars. The

Respuesta de 41 variedades prometedoras de caña de azúcar a la enfermedad de la escaldadura de la hoja (Xanthomonas albilineans).

OpenAIRE

López Vázquez, José de Jesús

2013-01-01

La escaldadura de la hoja (Xanthomonas albilineans), es una de las enfermedades bacterianas de mayor importancia en el cultivo de caña de azúcar. Afecta la calidad del jugo y en variedades susceptibles ocasiona pérdidas estimadas entre el 90 y 100%. Con el objetivo fue caracterizar molecularmente el agente causal, evaluar el método apropiado de inoculación y evaluar la respuesta de 41 variedades de caña de azúcar a la escaldadura de la hoja. Las variedades fueron inoculadas en campo por tres ...

In Vitro and In Vivo Antibacterial Activity of Some Organic and Inorganic Salts Against Asiatic Citrus Canker Agent Xanthomonas Citri Subsp. Citri

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Vahideh Hasabi

2014-07-01

Full Text Available Asiatic citrus canker caused by Xanthomonas citri subsp. citri is becoming a disease of high economic impact, affecting all types of important citrus crops. In this study, the potential antibacterial activity of ten organic and inorganic salts on X. citri subsp. citri and on citrus canker disease development was evaluated. Among the salt compounds, copper, iron and zinc inorganic salts particularly zinc (with the highest diameter of inhibition, the lowest MIC and MBC values and the highest bacterial growth inhibitory effect had direct antibacterial activity and strongly reduced the development of canker disease and bacterial population of lime plants.

PATHOTYPE GROUPING OF Xanthomonas oryzae pv. oryzae ISOLATES FROM SOUTH SULAWESI AND SOUTHEAST SULAWESI

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Andi Khaeruni

2013-06-01

Full Text Available Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo is an important rice disease, and has caused significant economic losses. This research aimed to determine the pathotype grouping and the distribution of Xoo isolates of South and Southeast Sulawesi. In order to obtain the information, 61 Xoo isolates of South Sulawesi and 29 isolates of Southeast Sulawesi were evaluated for their pathotype grouping against 5 diffential varieties. Research results showed that in South Sulawesi there were 2 pathotype groups, namely pathotype IV (32.79% and pathotype VIII(67.21%. Pathotype VIII was widely distributed over the Western and Central areas of South Sulawesi, whereas pathotype IV was widely distributed over the Southern area. In Southeast Sulawesi, it was found 5 pathotypes, namely pathotypes IV (27.58%, VI (10.34%, VIII (13.79%, IX (20.68%, and X (27.58%, with a limited and scattered distribution pattern on several areas. These results indicate that Xoo pathotype groups in South Sulawesi and Southeast Sulawesi are varied and tend to sift to more virulent pathotypes.

Different transcriptional response to Xanthomonas citri subsp. citri between kumquat and sweet orange with contrasting canker tolerance.

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Xing-Zheng Fu

Full Text Available Citrus canker disease caused by Xanthomonas citri subsp. citri (Xcc is one of the most devastating biotic stresses affecting the citrus industry. Meiwa kumquat (Fortunella crassifolia is canker-resistant, while Newhall navel orange (Citrus sinensis Osbeck is canker-sensitive. To understand the molecular mechanisms underlying the differences in responses to Xcc, transcriptomic profiles of these two genotypes following Xcc attack were compared by using the Affymetrix citrus genome GeneChip. A total of 794 and 1324 differentially expressed genes (DEGs were identified as canker-responsive genes in Meiwa and Newhall, respectively. Of these, 230 genes were expressed in common between both genotypes, while 564 and 1094 genes were only significantly expressed in either Meiwa or Newhall. Gene ontology (GO annotation and Singular Enrichment Analysis (SEA of the DEGs showed that genes related to the cell wall and polysaccharide metabolism were induced for basic defense in both Meiwa and Newhall, such as chitinase, glucanase and thaumatin-like protein. Moreover, apart from inducing basic defense, Meiwa showed specially upregulated expression of several genes involved in the response to biotic stimulus, defense response, and cation binding as comparing with Newhall. And in Newhall, abundant photosynthesis-related genes were significantly down-regulated, which may be in order to ensure the basic defense. This study revealed different molecular responses to canker disease in Meiwa and Newhall, affording insight into the response to canker and providing valuable information for the identification of potential genes for engineering canker tolerance in the future.

Biological, serological and molecular techniques to xanthomonas axonopodis pv. Ci tri Asymptomatic detection

International Nuclear Information System (INIS)

Peyrou, M.; Del Campo, R.; Russi, P.; Mara, H.; Rigamonti, N.; Larrechart, L.; Perez, E.

2012-01-01

Xanthomonas axonopodis pv. ci tri (X ac) produces citrus canker disease in all citrus commercial species. The bacteria can be disseminated through vegetative propagation material in asymptomatic form. To optimize bacteria detection techniques applicable to asymptomatic citrus plant tissue routine analysis, ELISA, Immunofluorescence, Pcr, qRT P CR and host plant inoculation (bioassay) diagnostic techniques were compared. Tests were made from decimal dilutions between 108 uf6.ml-1 and 102 ufc.mL-1 using a pure culture of 49b strain.The detection level obtained was 1.8 x 102 ufc.mL-1 using Inmunofluorescence; 1.8x104 ufc.mL-1 with indirect ELISA, 1.8 x 103 ufc.mL-1 by means of PCR; 10 ufc.mL-1 through of qRT P CR and 230 ufc.mL-1 in sour orange inoculated plants. The experiment was repeated at least three times for each technique. Considering this result, and taking into account that sensitivity, practicity and cost, are important when a great number of plants need to be tested, the PCR and inoculation in host plants were those that met the best characteristics to be evaluated in asymptomatic plant material

Xanthan biosynthesis by Xanthomonas campestris ATCC 13951 on wastewaters from white grape processing

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Rončević Zorana

2017-01-01

Full Text Available Wastewaters from grape processing in wineries are characterized by large seasonal fluctuations in volume and composition, and are often discarded into environment with little or no treatment. The biotechnological production of valuable products is the most promising alternative for reducing the negative environmental impact and recycling these effluents. Results from previous study show that mixed winery wastewaters, after additional optimization of the medium preparation, may be a suitable raw material for industrial xanthan production. Therefore, the aim of this work was to examine the possibility of xanthan production by Xanthomonas campestris ATCC 13951 on mixed wastewaters from different stages of white grape processing in winery with initial sugars content of 20 g/L. In addition to the media characteristics and indicators of biopolymer quality, raw xanthan yield and degree of sugars conversion into product were determined in order to examine the success of performed bioprocess. The results for biopolymer yield (14.66 g/L and sugars conversion into desired product (70.21% obtained in applied experimental conditions confirm that wastewaters from white grape processing have a great potential to be used as a substrate for xanthan biosynthesis.

Insights into xanthomonas axonopodis pv. Citri biofilm through proteomics

KAUST Repository

Zimaro, Tamara

2013-08-07

Background: Xanthomonas axonopodis pv. Citri (X. a. pv. Citri) causes citrus canker that can result in defoliation and premature fruit drop with significant production losses worldwide. Biofilm formation is an important process in bacterial pathogens and several lines of evidence suggest that in X. a. pv. Citri this process is a requirement to achieve maximal virulence since it has a major role in host interactions. In this study, proteomics was used to gain further insights into the functions of biofilms. Results: In order to identify differentially expressed proteins, a comparative proteomic study using 2D difference gel electrophoresis was carried out on X. a. pv. Citri mature biofilm and planktonic cells. The biofilm proteome showed major variations in the composition of outer membrane proteins and receptor or transport proteins. Among them, several porins and TonB-dependent receptor were differentially regulated in the biofilm compared to the planktonic cells, indicating that these proteins may serve in maintaining specific membrane-associated functions including signaling and cellular homeostasis. In biofilms, UDP-glucose dehydrogenase with a major role in exopolysaccharide production and the non-fimbrial adhesin YapH involved in adherence were over-expressed, while a polynucleotide phosphorylase that was demonstrated to negatively control biofilm formation in E. coli was down-regulated. In addition, several proteins involved in protein synthesis, folding and stabilization were up-regulated in biofilms. Interestingly, some proteins related to energy production, such as ATP-synthase were down-regulated in biofilms. Moreover, a number of enzymes of the tricarboxylic acid cycle were differentially expressed. In addition, X. a. pv. Citri biofilms also showed down-regulation of several antioxidant enzymes. The respective gene expression patterns of several identified proteins in both X. a. pv. Citri mature biofilm and planktonic cells were evaluated by

Characterization of the sulfate uptake and assimilation pathway from Xanthomonas citri - targets for bacterial growth inhibitors

Energy Technology Data Exchange (ETDEWEB)

Tambascia, C.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

2012-07-01

Full text: Microorganisms require sulfur for growth and obtain it either for inorganic sulfate or organosulfur compounds. ATP-Binding Cassete (SulT family) or major facilitator superfamily-type (SulP) transporters are responsible for the sulfate transport into the cell. In Xanthomonas citri, the phytopathogenic bacterium that causes the canker citrus disease, there are no reports related to the importance of these transporters during in vitro or in vivo infection. We identified in X. citri genome all the genes that belong to the well-characterized cys regulon from Escherichia coli and Salmonella typhimurium, which includes three ABC transporters and all the enzymes necessary for sulfate oxide reduction to sulfide and cysteine. Once these genes have been shown to be extremely important for bacteria growth and development in different environments, we chose the sbpcysWUA and cysDNCHIJG operons, which encodes the ABC inorganic sulfate ABC transporter and all the enzymes necessary for conversion of sulfate in cysteine, respectively. As a step for crystallization trials and resolution of their tridimensional structures, the referred genes were amplified and cloned into the cloning vector pGEM T-easy. In addition, using bioinformatics tools and molecular modeling we characterized all the protein functions as well as built tridimensional models of their structure for determination of the active sites. The importance of each protein is discussed aiming the discovery of a good target for development of inhibitors that could block the bacterium growth. (author)

Characterization of the sulfate uptake and assimilation pathway from Xanthomonas citri - targets for bacterial growth inhibitors

International Nuclear Information System (INIS)

Tambascia, C.; Balan, A.

2012-01-01

Full text: Microorganisms require sulfur for growth and obtain it either for inorganic sulfate or organosulfur compounds. ATP-Binding Cassete (SulT family) or major facilitator superfamily-type (SulP) transporters are responsible for the sulfate transport into the cell. In Xanthomonas citri, the phytopathogenic bacterium that causes the canker citrus disease, there are no reports related to the importance of these transporters during in vitro or in vivo infection. We identified in X. citri genome all the genes that belong to the well-characterized cys regulon from Escherichia coli and Salmonella typhimurium, which includes three ABC transporters and all the enzymes necessary for sulfate oxide reduction to sulfide and cysteine. Once these genes have been shown to be extremely important for bacteria growth and development in different environments, we chose the sbpcysWUA and cysDNCHIJG operons, which encodes the ABC inorganic sulfate ABC transporter and all the enzymes necessary for conversion of sulfate in cysteine, respectively. As a step for crystallization trials and resolution of their tridimensional structures, the referred genes were amplified and cloned into the cloning vector pGEM T-easy. In addition, using bioinformatics tools and molecular modeling we characterized all the protein functions as well as built tridimensional models of their structure for determination of the active sites. The importance of each protein is discussed aiming the discovery of a good target for development of inhibitors that could block the bacterium growth. (author)

Gramíneas hospedeiras de Xanthomonas sp., agente causal da falsa estria vermelha da cana-de-açúcar Host range of Xanthomonas sp., causal agent of the false red stripe of sugarcane, among grasses

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Elaine Spindola Mantovani

2006-06-01

Full Text Available Falsa estria vermelha (FEV, uma nova doença causada por Xanthomonas sp., é diferente diferente de todas as outras doenças já descritas em cana-de-açúcar. Ela está distribuída por toda as principais regiões canavieiras do centro-sul do Brasil, mas ainda não foi detectada no norte e nordeste do Brasil nem em qualquer outro país. O presente estudo determinou a gama de culturas e plantas daninhas hospedeiras da bactéria dentre espécies pertencentes às gramíneas, através de inoculação por injeção e pulverização de suspensão bacteriana. Além da cana-de-açúcar, entre as 31 diferentes espécies estudadas, apenas sorgo, milho e aveia apresentaram sintomas, 15 dias após a inoculação. Em sorgo, no ponto de inoculação, apareceram estrias avermelhadas coalescentes. As folhas apresentaram típicas estrias vermelhas finas (1 mm, longas e paralelas às nervuras, com presença de exsudato bacteriano. Até mesmo as inflorescências apresentaram pontuações avermelhadas. Plantas de milho inoculadas com seringa apresentaram sintomas de anasarca e descoloração de tecidos ao redor do ponto de inoculação e estrias cloróticas (2-3 mm no limbo foliar; porém, sem exsudato de bactéria. Apenas folhas de cevada apresentaram sintomas quando inoculadas por pulverização. As lesões iniciais eram estrias e manchas de cor palha, evoluindo para uma necrose total das folhas, causando a morte das plantas. A partir de folhas sintomáticas de cana-de-açúcar, sorgo, milho e aveia, realizaram-se re-isolamentos, obtendo-se culturas puras de Xanthomonas sp. cuja identidade foi comprovada através de testes sorológicos e por Rep-PCR. Diante desses resultados, surge a necessidade de realização de inspeções e campos de cultivo de sorgo, milho e aveia para verificar a presença da bactéria da FEV e determinar se o patógeno pode infectar essas culturas naturalmente.False Red Stripe (FRS, a new disease caused by Xanthomonas sp., is different

The Arabidopsis flagellin receptor FLS2 mediates the perception of Xanthomonas Ax21 secreted peptides.

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Danna, Cristian H; Millet, Yves A; Koller, Teresa; Han, Sang-Wook; Bent, Andrew F; Ronald, Pamela C; Ausubel, Frederick M

2011-05-31

Detection of microbes by plants relies in part on an array of pattern-recognition receptors that recognize conserved microbial signatures, so-called "microbe-associated molecular patterns." The Arabidopsis thaliana receptor-like kinase FLS2 is the pattern-recognition receptor for bacterial flagellin. Similarly to FLS2, the rice transmembrane protein XA21 is the receptor for the sulfated form of the Xanthomonas oryzae pv. oryzae secreted protein Ax21. Here we show that Ax21-derived peptides activate Arabidopsis immunity, triggering responses similar to those elicited by flagellin, including an oxidative burst, induction of defense-response genes, and enhanced resistance to bacterial pathogens. To identify Arabidopsis Xa21 functional homologs, we used a reverse genetics approach to screen T-DNA insertion mutants corresponding to all 47 of the Arabidopsis genes encoding non-RD kinases belonging to the interleukin-1 receptor-associated kinase (IRAK) family. Surprisingly, among all of these mutant lines, only fls2 mutants exhibited a significant loss of response to Ax21-derived peptides. Ax21 peptides also failed to activate defense-related responses in an fls2-24 mutant that does not bind Flg22. Moreover, a Flg22Δ2 variant of Flg22 that binds to FLS2 but does not activate FLS2-mediated signaling suppressed Ax21-derived peptide signaling, indicating mutually exclusive perception of Flg22 or Ax21 peptides by FLS2. The data indicate that FLS2 functions beyond flagellin perception to detect other microbe-associated molecular patterns.

A simple method to design non-collision relative orbits for close spacecraft formation flying

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Jiang, Wei; Li, JunFeng; Jiang, FangHua; Bernelli-Zazzera, Franco

2018-05-01

A set of linearized relative motion equations of spacecraft flying on unperturbed elliptical orbits are specialized for particular cases, where the leader orbit is circular or equatorial. Based on these extended equations, we are able to analyze the relative motion regulation between a pair of spacecraft flying on arbitrary unperturbed orbits with the same semi-major axis in close formation. Given the initial orbital elements of the leader, this paper presents a simple way to design initial relative orbital elements of close spacecraft with the same semi-major axis, thus preventing collision under non-perturbed conditions. Considering the mean influence of J 2 perturbation, namely secular J 2 perturbation, we derive the mean derivatives of orbital element differences, and then expand them to first order. Thus the first order expansion of orbital element differences can be added to the relative motion equations for further analysis. For a pair of spacecraft that will never collide under non-perturbed situations, we present a simple method to determine whether a collision will occur when J 2 perturbation is considered. Examples are given to prove the validity of the extended relative motion equations and to illustrate how the methods presented can be used. The simple method for designing initial relative orbital elements proposed here could be helpful to the preliminary design of the relative orbital elements between spacecraft in a close formation, when collision avoidance is necessary.

[Phylogenetic analysis of closely related Leuconostoc citreum species based on partial housekeeping genes].

Science.gov (United States)

Lv, Qiang; Chen, Ming; Xu, Haiyan; Song, Yuqin; Sun, Zhihong; Dan, Tong; Sun, Tiansong

2013-07-04

Using the 16S rRNA, dnaA, murC and pyrG gene sequences, we identified the phylogenetic relationship among closely related Leuconostoc citreum species. Seven Leu. citreum strains originally isolated from sourdough were characterized by PCR methods to amplify the dnaA, murC and pyrG gene sequences, which were determined to assess the suitability as phylogenetic markers. Then, we estimated the genetic distance and constructed the phylogenetic trees including 16S rRNA and above mentioned three housekeeping genes combining with published corresponding sequences. By comparing the phylogenetic trees, the topology of three housekeeping genes trees were consistent with that of 16S rRNA gene. The homology of closely related Leu. citreum species among dnaA, murC, pyrG and 16S rRNA gene sequences were different, ranged from75.5% to 97.2%, 50.2% to 99.7%, 65.0% to 99.8% and 98.5% 100%, respectively. The phylogenetic relationship of three housekeeping genes sequences were highly consistent with the results of 16S rRNA gene sequence, while the genetic distance of these housekeeping genes were extremely high than 16S rRNA gene. Consequently, the dnaA, murC and pyrG gene are suitable for classification and identification closely related Leu. citreum species.

The relation of close friends to cognitive performance in old age: the mediating role of leisure activities.

Science.gov (United States)

Ihle, Andreas; Oris, Michel; Baeriswyl, Marie; Kliegel, Matthias

2018-06-01

ABSTRACTBackground:From a conceptual point of view, close friends are an important resource for promoting activity engagement in old age. Leisure activity engagement in turn is a key predictor of cognitive performance. Empirically, it remains unclear so far whether leisure activity engagement mediates between having close friends on the one hand and cognitive performance on the other, which we investigated in a large sample of older adults. We assessed cognitive performance (Mill Hill vocabulary scale and Trail Making Test (TMT) parts A and B) in 2,812 older adults. Participants reported information on leisure activity engagement and close friends. A larger number of leisure activities and a larger number of close friends were significantly related to better cognitive performance in the Mill Hill vocabulary scale and TMT parts A and B. A larger number of close friends were significantly related to a larger number of leisure activities. The number of leisure activities mediated more than half of the relation of the number of close friends to performance in all three cognitive measures. Having close friends may be helpful to stimulate and promote activity participation in old age. By enhancing individuals' cognitive reserve, this may finally preserve their cognitive performance level in old age.

M-GCAT: interactively and efficiently constructing large-scale multiple genome comparison frameworks in closely related species

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Messeguer Xavier

2006-10-01

Full Text Available Abstract Background Due to recent advances in whole genome shotgun sequencing and assembly technologies, the financial cost of decoding an organism's DNA has been drastically reduced, resulting in a recent explosion of genomic sequencing projects. This increase in related genomic data will allow for in depth studies of evolution in closely related species through multiple whole genome comparisons. Results To facilitate such comparisons, we present an interactive multiple genome comparison and alignment tool, M-GCAT, that can efficiently construct multiple genome comparison frameworks in closely related species. M-GCAT is able to compare and identify highly conserved regions in up to 20 closely related bacterial species in minutes on a standard computer, and as many as 90 (containing 75 cloned genomes from a set of 15 published enterobacterial genomes in an hour. M-GCAT also incorporates a novel comparative genomics data visualization interface allowing the user to globally and locally examine and inspect the conserved regions and gene annotations. Conclusion M-GCAT is an interactive comparative genomics tool well suited for quickly generating multiple genome comparisons frameworks and alignments among closely related species. M-GCAT is freely available for download for academic and non-commercial use at: http://alggen.lsi.upc.es/recerca/align/mgcat/intro-mgcat.html.

1H HRMAS NMR spectroscopy and chemometrics for evaluation of metabolic changes in citrus sinensis Caused by Xanthomonas axonopodis pv. citri

International Nuclear Information System (INIS)

Silva, Lorena M.A.; Alves Filho, Elenilson G.; Choze, Rafael; Liao, Luciano M.; Alcantara, Glaucia B.

2012-01-01

Xanthomonas axonopodis (Xac) bacterium causes one of the most feared and untreatable diseases in citriculture: citrus canker. To understand the response mechanisms of orange trees when attacked by Xac, leaves and fruits of Citrus sinensis were directly evaluated by HRMAS NMR (high resolution magic angle spinning nuclear magnetic resonance) spectroscopy. This technique allows the analysis of samples without laborious pre-treatments and also allows access to important information about chemical composition of samples. The orange tree leaves and fruit peels investigated in this study demonstrated the biochemical changes caused by Xac. Aided by chemometric analysis, the HRMAS NMR results show relevant changes in amino acids, carbohydrates, organic acids and terpenoids content. (author)

Comparative RNA-seq analysis of early-infected peach leaves by the invasive phytopathogen Xanthomonas arboricola pv. pruni.

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Didier Socquet-Juglard

Full Text Available Xanthomonas arboricola pv. pruni is a quarantine bacterial pathogen that threatens peach production by causing necrotic spots on leaves and fruits, thus with the potential of severely reducing yields. The current understanding of the host plant defense responses to the pathogen is very limited. Using whole transcriptome sequencing, differential gene expression was analyzed at two time points, 2 h and 12 h post inoculation (hpi, by comparing the inoculated samples to their respective controls. On the total of 19,781 known peach genes that were expressed in all time points and conditions, 34 and 263 were differentially expressed at 2 and 12 hpi, respectively. Of those, 82% and 40% were up-regulated, respectively; and 18% and 60% were down-regulated, respectively. The functional annotation based on gene ontology (GO analysis highlighted that genes involved in metabolic process and response to stress were particularly represented at 2 hpi whereas at 12 hpi cellular and metabolic processes were the categories with the highest number of genes differentially expressed. Of particular interest among the differentially expressed genes identified were several pathogen-associated molecular pattern (PAMP receptors, disease resistance genes including several RPM1-like and pathogenesis related thaumatin encoding genes. Other genes involved in photosynthesis, in cell wall reorganization, in hormone signaling pathways or encoding cytochrome were also differentially expressed. In addition, novel transcripts were identified, providing another basis for further characterization of plant defense-related genes. Overall, this study gives a first insight of the peach defense mechanisms during the very early stages of infection with a bacterial disease in the case of a compatible interaction.

Comparative Transcriptome Profiling of Rice Near-Isogenic Line Carrying Xa23 under Infection of Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Tariq, Rezwan; Wang, Chunlian; Qin, Tengfei; Xu, Feifei; Tang, Yongchao; Gao, Ying; Ji, Zhiyuan; Zhao, Kaijun

2018-03-02

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae ( Xoo ), is an overwhelming disease in rice-growing regions worldwide. Our previous studies revealed that the executor R gene Xa23 confers broad-spectrum disease resistance to all naturally occurring biotypes of Xoo . In this study, comparative transcriptomic profiling of two near-isogenic lines (NILs), CBB23 (harboring Xa23 ) and JG30 (without Xa23 ), before and after infection of the Xoo strain, PXO99 A , was done by RNA sequencing, to identify genes associated with the resistance. After high throughput sequencing, 1645 differentially expressed genes (DEGs) were identified between CBB23 and JG30 at different time points. Gene Ontlogy (GO) analysis categorized the DEGs into biological process, molecular function, and cellular component. KEGG analysis categorized the DEGs into different pathways, and phenylpropanoid biosynthesis was the most prominent pathway, followed by biosynthesis of plant hormones, flavonoid biosynthesis, and glycolysis/gluconeogenesis. Further analysis led to the identification of differentially expressed transcription factors (TFs) and different kinase responsive genes in CBB23, than that in JG30. Besides TFs and kinase responsive genes, DEGs related to ethylene, jasmonic acid, and secondary metabolites were also identified in both genotypes after PXO99 A infection. The data of DEGs are a precious resource for further clarifying the network of Xa23 -mediated resistance.

Limpeza clonal de mudas de videira infectadas por Xanthomonas campestris pv. viticola

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Adriano Márcio Freire Silva

2013-03-01

Full Text Available O cancro bacteriano da videira é causado por Xanthomonas campestris pv. viticola (Xcv. Visando à limpeza clonal de mudas de 'Red Globe', foram estudados: tamanho ideal de ápices e gemas axilares para cultivo em meio de Galzy modificado (MGM; efeito da termoterapia (38ºC/30 dias; e ação de antibióticos na eliminação de Xcv em videiras infectadas. Os percentuais de contaminação por Xcv e de regeneração foram analisados, e as plantas obtidas foram indexadas em meio ágar nutritivo-dextrose-extrato de levedura-ampicilina (NYDAM, seguindo-se teste de patogenicidade. O cultivo de explantes com 3 mm possibilitou a obtenção de plantas livres da bactéria, com regeneração 14,3 vezes maior que explantes com 1 mm. A termoterapia de mudas infectadas, associada ao cultivo in vitro, não eliminou o patógeno. O cultivo de explantes com 10 mm, durante 40 dias em MGM + cefotaxima (300 mg L-1, proporcionou limpeza clonal das mudas. A indexação de plantas de videira regeneradas in vitro, quanto à infecção por Xcv utilizando NYDAM, seguida de teste de patogenicidade, é uma alternativa econômica e eficiente para produção de mudas de alta qualidade fitossanitária.

Immunity at Cauliflower Hydathodes Controls Systemic Infection by Xanthomonas campestris pv campestris.

Science.gov (United States)

Cerutti, Aude; Jauneau, Alain; Auriac, Marie-Christine; Lauber, Emmanuelle; Martinez, Yves; Chiarenza, Serge; Leonhardt, Nathalie; Berthomé, Richard; Noël, Laurent D

2017-06-01

Hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. We report here on the detailed anatomy of cauliflower ( Brassica oleracea ) and Arabidopsis ( Arabidopsis thaliana ) hydathodes. Hydathode surface presents pores resembling stomata giving access to large cavities. Beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. Arabidopsis hydathode pores were responsive to ABA and light similar to stomata. The flg22 flagellin peptide, a well-characterized elicitor of plant basal immunity, did not induce closure of hydathode pores in contrast to stomata. Because hydathodes are natural infection routes for several pathogens, we investigated hydathode infection by the adapted vascular phytopathogenic bacterium Xanthomonas campestris pv campestris ( Xcc ), the causal agent of black rot disease of Brassicaceae. Microscopic observations of hydathodes six days postinoculation indicated a digestion of the epithem cells and a high bacterial multiplication. Postinvasive immunity was shown to limit pathogen growth in the epithem and is actively suppressed by the type III secretion system and its effector proteins. Altogether, these results give a detailed anatomic description of Brassicaceae hydathodes and highlight the efficient use of this tissue as an initial niche for subsequent vascular systemic dissemination of Xcc in distant plant tissues. © 2017 American Society of Plant Biologists. All Rights Reserved.

Relational mobility explains between- and within-culture differences in self-disclosure to close friends.

Science.gov (United States)

Schug, Joanna; Yuki, Masaki; Maddux, William

2010-10-01

In the current research, we tested a novel explanation for previously demonstrated findings that East Asians disclose less personal information to other people than do Westerners. We propose that both between- and within-culture differences in self-disclosure to close friends may be explained by the construct of relational mobility, the general degree to which individuals in a society have opportunities to form new relationships and terminate old ones. In Study 1, we found that cross-cultural differences (Japan vs. United States) in self-disclosure to a close friend were mediated by individuals' perceptions of relational mobility. In Study 2, two separate measures of relational mobility predicted self-disclosure within a single culture (Japan), and this relationship was mediated by the motivation to engage in self-disclosure to strengthen personal relationships. We conclude that societies and social contexts higher in relational mobility (in which relationships can be formed and dissolved relatively easily) produce stronger incentives for self-disclosure as a social-commitment device.

Preparation, crystallization and preliminary X-ray characterization of a conserved hypothetical protein XC1692 from Xanthomonas campestris

International Nuclear Information System (INIS)

Chin, Ko-Hsin; Huang, Zhao-Wei; Wei, Kun-Chou; Chou, Chia-Cheng; Lee, Cheng-Chung; Shr, Hui-Lin; Gao, Fei Philip; Lyu, Ping-Chiang; Wang, Andrew H.-J.; Chou, Shan-Ho

2005-01-01

A conserved hypothetical protein XC1692 from X. campestris pv. campestris has been overexpressed in E. coli. The purified recombinant protein crystallized in a variety of forms and diffracted to a resolution of at least 1.45 Å. Xanthomonas campestris pv. campestris strain 17 is a Gram-negative yellow-pigmented pathogenic bacterium that causes black rot, one of the major worldwide diseases of cruciferous crops. Its genome contains approximately 4500 genes, one third of which have no known structure and/or function yet are highly conserved among several different bacterial genuses. One of these gene products is XC1692 protein, containing 141 amino acids. It was overexpressed in Escherichia coli, purified and crystallized in a variety of forms using the hanging-drop vapour-diffusion method. The crystals diffract to at least 1.45 Å resolution. They are hexagonal and belong to space group P6 3 , with unit-cell parameters a = b = 56.9, c = 71.0 Å. They contain one molecule per asymmetric unit

Crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri

International Nuclear Information System (INIS)

Santacruz, C. P.; Balan, A.; Ferreira, L. C. S.; Barbosa, J. A. R. G.

2006-01-01

The molybdate-binding protein (ModA) from X. axonopodis pv. citri was crystallized with sodium molybdate in the presence of PEG or sulfate. The crystal diffracted to a maximum resolution of 1.7 Å and belongs to the orthorhombic space group C222 1, with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 Å using synchrotron radiation. The crystal belongs to the orthorhombic space group C222 1 , with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress

Crystallization, data collection and phasing of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri

Energy Technology Data Exchange (ETDEWEB)

Santacruz, C. P.; Balan, A.; Ferreira, L. C. S. [Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil); Barbosa, J. A. R. G., E-mail: joao@lnls.br [Centro de Biologia Molecular e Estrutural (CeBiMe), Laboratório Nacional de Luz Síncrotron (LNLS), CP 6192, Campinas, SP 13084-971 (Brazil); Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, São Paulo, SP (Brazil)

2006-03-01

The molybdate-binding protein (ModA) from X. axonopodis pv. citri was crystallized with sodium molybdate in the presence of PEG or sulfate. The crystal diffracted to a maximum resolution of 1.7 Å and belongs to the orthorhombic space group C222{sub 1,} with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 Å using synchrotron radiation. The crystal belongs to the orthorhombic space group C222{sub 1}, with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 Å. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress.

A mutation in the aroE gene affects pigment production, virulence, and chemotaxis in Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Kim, Hong-Il; Noh, Tae-Hwan; Lee, Chang-Soo; Park, Young-Jin

2015-01-01

Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB) in rice. To study its function, a random insertion mutation library of Xoo was constructed using the Tn5 transposon. A mutant strain with decreased virulence against the susceptible rice cultivar IR24 was isolated from the library (aroE mutant), which also had extremely low pigment production. Thermal asymmetric interlaced-polymerase chain reaction (TAIL-PCR) and sequence analysis of the mutant revealed that the transposon was inserted into the aroE gene (encoding shikimate dehydrogenase). To investigate gene expression changes in the pigment- and virulence-deficient mutant, DNA microarray analysis was performed, which showed downregulation of 20 genes involved in the chemotaxis of Xoo. Our findings reveal that mutation of the aroE gene affects virulence and pigment production, as well as expression of genes involved in Xoo chemotaxis. Copyright © 2014 Elsevier GmbH. All rights reserved.

Development and validation of a real-time quantitative PCR assay to detect Xanthomonas axonopodis pv. allii from onion seed.

Science.gov (United States)

Robène, Isabelle; Perret, Marion; Jouen, Emmanuel; Escalon, Aline; Maillot, Marie-Véronique; Chabirand, Aude; Moreau, Aurélie; Laurent, Annie; Chiroleu, Frédéric; Pruvost, Olivier

2015-07-01

Bacterial blight of onion is an emerging disease threatening world onion production. The causal agent Xanthomonas axonopodis pv. allii is seed transmitted and a reliable and sensitive tool is needed to monitor seed exchanges. A triplex quantitative real-time PCR assay was developed targeting two X. axonopodis pv. allii-specific markers and an internal control chosen in 5.8S rRNA gene from Alliaceae. Amplification of at least one marker indicates the presence of the bacterium in seed extracts. This real-time PCR assay detected all the 79 X. axonopodis pv. allii strains tested and excluded 85.2% of the 135 non-target strains and particularly all 39 saprophytic and pathogenic bacteria associated with onion. Cross-reactions were mainly obtained for strains assigned to nine phylogenetically related X. axonopodis pathovars. The cycle cut-off was estimated statistically at 36.3 considering a risk of false positive of 1%. The limit of detection obtained in at least 95% of the time (LOD 95%) was 5×10(3) CFU/g (colony forming unit/g). The sensitivity threshold was found to be 1 infected seed in 32,790 seeds. This real-time PCR assay should be useful for preventing the long-distance spread of X. axonopodis pv. allii via contaminated seed lots and determining the epidemiology of the bacterium. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification of an Extracellular Endoglucanase That Is Required for Full Virulence in Xanthomonas citri subsp. citri.

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Tian Xia

Full Text Available Xanthomonas citri subsp. citri causes citrus canker disease, which is characterized by the formation of water-soaked lesions, white or yellow spongy pustules and brown corky canker. In this work, we report the contribution of extracellular endoglucanase to canker development during infection. The ectopic expression of nine putative cellulases in Escherichia coli indicated that two endoglucanases, BglC3 and EngXCA, show carboxymethyl cellulase activity. Both bglC3 and engXCA genes were transcribed in X. citri subsp. citri, however, only BglC3 protein was detected outside the cell in western blot analysis. The deletion of bglC3 gene resulted in complete loss of extracellular carboxymethyl cellulase activity and delayed the onset of canker symptoms in both infiltration- and wound-inoculation assays. When growing in plant tissue, the cell density of bglC3 mutant was lower than that of the wild type. Our data demonstrated that BglC3 is an extracellular endoglucanase required for the full virulence of X. citri subsp. citri.

Studies on the physiological changes in the rice plants infected with Xanthomonas campestris pv. oryzae, (3)

International Nuclear Information System (INIS)

Watanabe, Minoru; Samejima, Shin-ichi; Hosokawa, Daijiro

1980-01-01

Accumulation of 14 C-photosynthetic assimilates in rice leaves infected with Xanthomonas campestris pv. oryzae was studied by using autoradiography for the purpose of elucidating the movement of nutrients from healthy tissues to the infected parts. When rice plants were exposed to 14 CO 2 immediately after inoculation, 14 C-photosynthetic assimilates did not accumulate in and around the inoculated spots of leaves until the lesions became visible, i.e., approximately 7 days after inoculation. When the leaves were exposed to 14 CO 2 before visible lesions appeared, 2 and 5 days after inoculation, the assimilates did not accumulate in the inoculated areas, but apparently accumulated in the lesions 24 hr later on from the exposure of leaves with visible lesions. In the newly formed lesions, accumulation site corresponded to the yellow streak parts of lesions along leaf veins. In the large and old lesions, assimilates hardly any accumulated in the center of lesions, grayish-white in color, but accumulated in the border parts of lesions adjacent to healthy tissues which are developing and yellow streak in symptoms. (author)

Cultivar Variation in Hormonal Balance Is a Significant Determinant of Disease Susceptibility to Xanthomonas campestris pv. campestris in Brassica napus

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Md. Tabibul Islam

2017-12-01

Full Text Available This study aimed to directly elucidate cultivar variation in disease susceptibility and disease responses in relation to hormonal status in the interaction of Brassica napus cultivars and Xanthomonas campestris pv. campestris (Xcc, the causal agent of black rot disease. Fully expanded leaves of six B. napus cultivars (cvs. Capitol, Youngsan, Saturnin, Colosse, Tamra, and Mosa were inoculated with Xcc. At 14 days post-inoculation with Xcc, cultivar variation in susceptibility or resistance was interpreted with defense responses as estimated by redox status, defensive metabolites, and expression of phenylpropanoid synthesis-related genes in relation to endogenous hormonal status. Disease susceptibility of six cultivars was distinguished by necrotic lesions in the Xcc-inoculated leaves and characterized concurrently based on the higher increase in reactive oxygen species and lipid peroxidation. Among these cultivars, as the susceptibility was higher, the ratios of abscisic acid (ABA/jasmonic acid (JA and salicylic acid (SA/JA tended to increase with enhanced expression of SA signaling regulatory gene NPR1 and transcriptional factor TGA1 and antagonistic suppression of JA-regulated gene PDF 1.2. In the resistant cultivar (cv. Capitol, accumulation of defensive metabolites with enhanced expression of genes involved in flavonoids (chalcone synthase, proanthocyanidins (anthocyanidin reductase, and hydroxycinnamic acids (ferulate-5-hydroxylase biosynthesis and higher redox status were observed, whereas the opposite results were obtained for susceptible cultivars (cvs. Mosa and Tamra. These results clearly indicate that cultivar variation in susceptibility to infection by Xcc was determined by enhanced alteration of the SA/JA ratio, as a negative regulator of redox status and phenylpropanoid synthesis in the Brasica napus–Xcc pathosystem.

High diversity in neuropeptide immunoreactivity patterns among three closely related species of Dinophilidae (Annelida)

DEFF Research Database (Denmark)

Kerbl, Alexandra; Conzelmann, Markus; Jékely, Gáspár

2017-01-01

Neuropeptides are conserved metazoan signaling molecules, and represent useful markers for comparative investigations on the morphology and function of the nervous system. However, little is known about the variation of neuropeptide expression patterns across closely related species in invertebrate...... groups other than insects. In this study, we compare the immunoreactivity patterns of 14 neuropeptides in three closely related microscopic dinophilid annelids (Dinophilus gyrociliatus, D. taeniatus and Trilobodrilus axi). The brains of all three species were found to consist of around 700 somata...... species. FMRFamide, MLD/pedal peptide, allatotropin, RNamide, excitatory peptide, and FVRIamide showed a broad localization within the brain, while calcitonin, SIFamide, vasotocin, RGWamide, DLamide, FLamide, FVamide, MIP, and serotonin were present in fewer cells in demarcated regions. The different...

Using mass spectrometry for identification of ABC transporters from Xanthomonas citri and mutants expressed in different growth conditions

International Nuclear Information System (INIS)

Faria, J.N.; Balan, A.; Paes Leme, A.F.

2012-01-01

Full text: Xanthomonas citri is a phytopathogenic bacterium that infects citrus plants causing significant losses for the economy. In our group, we have focused on the identification and characterization of ABC transport proteins of this bacterium, in order to determinate their function for growth in vitro and in vivo, during infection. ABC transporters represent one of the largest families of proteins, which transport since small molecules as ions up to oligopeptides and sugars. In prokaryotic cells many works have reported the ABC transport function in pathogenesis, resistance, biofilm formation, infectivity and DNA repair, but until our knowledge, there is no data related to these transporters and X. citri. So, In order to determinate which transporters are expressed in X. citri, we started a proteomic analysis based on mono and bi-dimensional gels associated to mass spectrometry analyses. After growing X. citri and two different mutants deleted for ssuA and nitA genes in LB and minimum media, cellular extracts were obtained and used for preparation of mono and bi-dimensional gels. Seven bands covering the expected mass of ABC transporter components (20 kDa to 50 kDa) in SDS-PAGE were cut off the gel, treated with trypsin and submitted to the MS for protein identification. The results of 2D gels were good enough and will serve as a standard for development of similar experiments in large scale. (author)

Immunity at Cauliflower Hydathodes Controls Systemic Infection by Xanthomonas campestris pv campestris1

Science.gov (United States)

Cerutti, Aude; Jauneau, Alain; Auriac, Marie-Christine; Lauber, Emmanuelle; Martinez, Yves; Chiarenza, Serge

2017-01-01

Hydathodes are water pores found on leaves of a wide range of vascular plants and are the sites of guttation. We report here on the detailed anatomy of cauliflower (Brassica oleracea) and Arabidopsis (Arabidopsis thaliana) hydathodes. Hydathode surface presents pores resembling stomata giving access to large cavities. Beneath, the epithem is composed of a lacunar and highly vascularized parenchyma offering a direct connection between leaf surface and xylem vessels. Arabidopsis hydathode pores were responsive to ABA and light similar to stomata. The flg22 flagellin peptide, a well-characterized elicitor of plant basal immunity, did not induce closure of hydathode pores in contrast to stomata. Because hydathodes are natural infection routes for several pathogens, we investigated hydathode infection by the adapted vascular phytopathogenic bacterium Xanthomonas campestris pv campestris (Xcc), the causal agent of black rot disease of Brassicaceae. Microscopic observations of hydathodes six days postinoculation indicated a digestion of the epithem cells and a high bacterial multiplication. Postinvasive immunity was shown to limit pathogen growth in the epithem and is actively suppressed by the type III secretion system and its effector proteins. Altogether, these results give a detailed anatomic description of Brassicaceae hydathodes and highlight the efficient use of this tissue as an initial niche for subsequent vascular systemic dissemination of Xcc in distant plant tissues. PMID:28184011

Power, attraction, and reference in macrolevel social relations: An analysis of closed groups and closed societies based on the psychology of the “Soviet person”

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Radina Nadezhda K.

2017-03-01

Full Text Available In this article the features of social-relationship systems are analyzed based on the data from a sociopsychological empirical study conducted in two stages (2002 and 2014 on a large sample with the help of g. Kelly’s Repertory grid Technique. A. V. Petrovsky’s three-factor interpersonal-relationships model as interpreted for closed groups by M. Yu. Kondratev and the concept of the closed society as described by Karl Popper provide the foundation for the theoretical hypothesis we tested. The empirical data obtained in 2002 came from 391 participants of different ages who were living in provincial towns in the Nizhny Novgorod region. The elderly respondents (232 people had lived almost all their lives under the Soviet regime; the middle-aged respondents (159 people got their education and started their careers in the USSR. Soviet society is considered to be closed because of its authoritarian and collectivist nature, static social structure, and dogmatic ideology. It is argued that both closed societies and closed groups are characterized by a rigid hierarchical social structure, isolation from other systems, and depersonalization of social relations. We have proved that members of a closed group and citizens of a closed society have similar social-relationship matrices.

Nanotechnology in plant disease management: DNA-directed silver nanoparticles on graphene oxide as an antibacterial against Xanthomonas perforans.

Science.gov (United States)

Ocsoy, Ismail; Paret, Mathews L; Ocsoy, Muserref Arslan; Kunwar, Sanju; Chen, Tao; You, Mingxu; Tan, Weihong

2013-10-22

Bacterial spot caused by Xanthomonas perforans is a major disease of tomatoes, leading to reduction in production by 10-50%. While copper (Cu)-based bactericides have been used for disease management, most of the X. perforans strains isolated from tomatoes in Florida and other locations worldwide are Cu-resistant. We have developed DNA-directed silver (Ag) nanoparticles (NPs) grown on graphene oxide (GO). These Ag@dsDNA@GO composites effectively decrease X. perforans cell viability in culture and on plants. At the very low concentration of 16 ppm of Ag@dsDNA@GO, composites show excellent antibacterial capability in culture with significant advantages in improved stability, enhanced antibacterial activity, and stronger adsorption properties. Application of Ag@dsDNA@GO at 100 ppm on tomato transplants in a greenhouse experiment significantly reduced the severity of bacterial spot disease compared to untreated plants, giving results similar to those of the current grower standard treatment, with no phytotoxicity.

Inter- and intra-guild interactions related to aphids in nettle (Urtica dioica L.) strips closed to field crops.

OpenAIRE

Alhmedi, A.; Haubruge, Eric; Bodson, Bernard; Francis, Frédéric

2006-01-01

A field experiment designed to assess the biodiversity related to nettle strips closed to crops, and more particularly the aphid and related beneficial populations, was established in experimental farm located in Gembloux (Belgium). Margin strips of nettle (Urtica dioica) closed to wheat (Triticum aestivum), green pea (Pisum sativum) and rape (Brassicae napus) fields were investigated. The diversity, abundance of aphids and related predators were analysed according to the plant crop species a...

Xanthomonas euvesicatoria Causes Bacterial Spot Disease on Pepper Plant in Korea

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Min-Seong Kyeon

2016-10-01

Full Text Available In 2004, bacterial spot-causing xanthomonads (BSX were reclassified into 4 species—Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes—gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

A universal nonlinear relation among boundary states in closed string field theory

International Nuclear Information System (INIS)

Kishimoto, Isao; Matsuo, Yutaka; Watanabe, Eitoku

2004-01-01

We show that the boundary states satisfy a nonlinear relation (the idempotency equation) with respect to the star product of closed string field theory. This relation is universal in the sense that various D-branes, including the infinitesimally deformed ones, satisfy the same equation, including the coefficient. This paper generalizes our analysis [hep-th/0306189] in the following senses. (1) We present a background-independent formulation based on conformal field theory. It illuminates the geometric nature of the relation and allows us to more systematically analyze the variations around the D-brane background. (2) We show that the Witten-type star product satisfies a similar relation but with a more divergent coefficient. (3) We determine the coefficient of the relation analytically. The result shows that the α parameter can be formally factored out, and the relation becomes universal. We present a conjecture on vacuum theory based on this computation. (author)

Rice Snl6, a cinnamoyl-CoA reductase-like gene family member, is required for NH1-mediated immunity to Xanthomonas oryzae pv. oryzae.

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Rebecca S Bart

2010-09-01

Full Text Available Rice NH1 (NPR1 homolog 1 is a key mediator of innate immunity. In both plants and animals, the innate immune response is often accompanied by rapid cell death at the site of pathogen infection. Over-expression of NH1 in rice results in resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo, constitutive expression of defense related genes and enhanced benzothiadiazole (BTH- mediated cell death. Here we describe a forward genetic screen that identified a suppressor of NH1-mediated lesion formation and resistance, snl6. Comparative genome hybridization and fine mapping rapidly identified the genomic location of the Snl6 gene. Snl6 is a member of the cinnamoyl-CoA reductase (CCR-like gene family. We show that Snl6 is required for NH1-mediated resistance to Xoo. Further, we show that Snl6 is required for pathogenesis-related gene expression. In contrast to previously described CCR family members, disruption of Snl6 does not result in an obvious morphologic phenotype. Snl6 mutants have reduced lignin content and increased sugar extractability, an important trait for the production of cellulosic biofuels. These results suggest the existence of a conserved group of CCR-like genes involved in the defense response, and with the potential to alter lignin content without affecting development.

The Dynamic Genome and Transcriptome of the Human Fungal Pathogen Blastomyces and Close Relative Emmonsia

OpenAIRE

Muñoz, José F.; Gauthier, Gregory M.; Desjardins, Christopher A.; Gallo, Juan E.; Holder, Jason; Sullivan, Thomas D.; Marty, Amber J.; Carmen, John C.; Chen, Zehua; Ding, Li; Gujja, Sharvari; Magrini, Vincent; Misas, Elizabeth; Mitreva, Makedonka; Priest, Margaret

2015-01-01

Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated...

Detection of Xanthomonas axonopodis pv. Phaseoli and Pseudomonas savastanoi pv. Phaseolicola on bean seed using a Milk-tween medium

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Popović Tatjana

2012-01-01

Full Text Available Bean production is threaten by phytopathogenic bacteria causing agents of blights, Xanthomonas axonopodis pv. phaseoli (Xap and Pseudomonas savastanoi pv. phaseolicola (Psp. Since there is no satisfactory chemical control for the disease, the recommended measures are preventive and include use of healthy seed, crop rotation, deep plowing and use of resistant cultivars. In this work we involved a detection method for isolation of Xap and Psp from bean seed to semi-selective medium Milk Agar Tween (MT. On this medium, Xap formed yellow, mucoid and convex colonies with two hydrolysis zones (less milk and more enlightened, and Psp formed whitish-cream, flat and round colonies. The identification of Xap and Psp was confirmed using the ELISA and PCR. Due to its selectivity, easy preparation and possibility of simultaneous detection of bacteria Xap and Psp, MT medium can be recommended for routine test of seed health for local seed or seed from import.

Negative aspects of close social relations and 10-year incident ischaemic heart disease hospitalization among middle-aged Danes

DEFF Research Database (Denmark)

Lund, Rikke; Rod, Naja Hulvej; Thielen, Karsten

2014-01-01

BACKGROUND: Little is known about the association between negative aspects of close social relations and development of ischaemic heart disease (IHD). We aim to address if the experience of worries/demands and conflicts with close social relations are related to risk of first-time hospitalization...... National Patient Registry. Cox regression analysis was used to analyse data and all analyses were adjusted for age, gender, social class, cohabitation, and depressive symptoms. RESULTS: Worries/demands from and conflicts with children were associated with IHD hospitalization in an exposure-dependent manner...

Direct suppression of a rice bacterial blight (Xanthomonas oryzae pv. oryzae) by monoterpene (S)-limonene.

Science.gov (United States)

Lee, Gun Woong; Chung, Moon-Soo; Kang, Mihyung; Chung, Byung Yeoup; Lee, Sungbeom

2016-05-01

Rice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is a severe disease of rice plants. Upon pathogen infection, rice biosynthesizes phytoalexins, including diterpenoids such as momilactones, phytocassanes, and oryzalexins. However, information on headspace volatiles in response to Xoo infection is limited. We have examined headspace volatile terpenes, induced by the infection of Xoo, and investigated their biological roles in the rice plant. Monoterpenes α-thujene, α-pinene, sabinene, myrcene, α-terpene, and (S)-limonene and sesquiterpenes cyclosativene, α-copaene, and β-elemene were detected from 1-week-old Xoo-infected rice seedlings, by solid-phase microextraction-gas chromatography-mass spectrometry. All monoterpenes were constitutively released from rice seedlings before Xoo infection. However, (S)-limonene emission was further elicited after exposure of the seedlings to Xoo in coincidence with upregulation of limonene synthase gene (OsTPS20) transcripts. Only the stereospecific (S)-limonene [and not (R)-limonene or other monoterpenes] severely inhibited Xoo growth, as confirmed by disc diffusion and liquid culture assays. Rice seedlings showed suppressed pathogenic symptoms suggestive of resistance to Xoo infection after foliar treatment with (S)-limonene. Collectively, our findings suggest that (S)-limonene is a volatile phytoanticipin, which plays a significant role in suppressing Xoo growth in rice seedlings.

Antibacterial activity of essential oils on Xanthomonas vesicatoria and control of bacterial spot in tomato

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Gilvaine Ciavareli Lucas

2012-03-01

Full Text Available The objective of this work was to evaluate the effects of plant essential oils (EOs on the growth of Xanthomonas vesicatoria, on bacterial morphology and ultrastructure, and on the severity of tomato bacterial spot. EOs from citronella, clove, cinnamon, lemongrass, eucalyptus, thyme, and tea tree were evaluated in vitro at concentrations of 0.1, 1.0, 10, and 100% in 1.0% powdered milk. The effect of EOs, at 0.1%, on the severity of tomato bacterial spot was evaluated in tomato seedlings under greenhouse conditions. The effects of citronella, lemongrass, clove, and tea tree EOs, at 0.1%, on X. vesicatoria cells were evaluated by transmission electron microscopy. All EOs showed direct toxic effect on the bacteria at a 10%-concentration in vitro. Under greenhouse conditions, the EOs of clove, citronella, tea tree, and lemongrass reduced disease severity. EOs of clove and tea tree, and streptomycin sulfate promoted loss of electron-dense material and alterations in the cytoplasm, whereas EO of tea tree promoted cytoplasm vacuolation, and those of citronella, lemongrass, clove, and tea tree caused damage to the bacterial cell wall. The EOs at a concentration of 0.1% reduce the severity of the disease.

Action of Chitosan Against Xanthomonas Pathogenic Bacteria Isolated from Euphorbia pulcherrima

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Yanli Wang

2012-06-01

Full Text Available The antibacterial activity and mechanism of two kinds of chitosan were investigated against twelve Xanthomonas strains recovered from Euphorbia pulcherrima. Results indicated that both chitosans markedly inhibited bacterial growth based on OD loss. Furthermore, the release of DNA and RNA from three selected strains was increased by both chitosans. However, the release of intracellular proteins was inhibited by both chitosans at different concentration and incubation times, except chitosan A at 0.1 mg/mL for 0.5 h incubation and 0.2 mg/mL for 2.0 h incubation increased the release of proteins, indicating the complexity of the interaction and cell membranes, which was affected by incubation time, bacterial species, chitosan type and concentration. Transmission electron microscopic observations revealed that chitosan caused changes in protoplast concentration and surface morphology. In some cells, the membranes and walls were badly distorted and disrupted, while other cells were enveloped by a thick and compact ribbon-like layer. The contrary influence on cell morphology may explain the differential effect in the release of material. In addition, scanning electron microscope and biofilm formation test revealed that both chitosans removed biofilm biomass. Overall, this study showed that membrane and biofilm play an important role in the antibacterial mechanism of chitosan.

Language Adaptation for Extending Post-Editing Estimates for Closely Related Languages

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Rios Miguel

2016-10-01

Full Text Available This paper presents an open-source toolkit for predicting human post-editing efforts for closely related languages. At the moment, training resources for the Quality Estimation task are available for very few language directions and domains. Available resources can be expanded on the assumption that MT errors and the amount of post-editing required to correct them are comparable across related languages, even if the feature frequencies differ. In this paper we report a toolkit for achieving language adaptation, which is based on learning new feature representation using transfer learning methods. In particular, we report performance of a method based on Self-Taught Learning which adapts the English-Spanish pair to produce Quality Estimation models for translation from English into Portuguese, Italian and other Romance languages using the publicly available Autodesk dataset.

Differentiation of closely related fungi by electronic nose analysis

DEFF Research Database (Denmark)

Karlshøj, Kristian; Nielsen, Per Væggemose; Larsen, Thomas Ostenfeld

2007-01-01

the electronic nose potentially responded to, volatile metabolites were collected, by diffusive sampling overnight onto tubes containing Tenax TA, between the 7th and 8th day of Incubation.Volatiles were analyzed by gas chromatography coupled to mass spectrometry and the results indicated that mail alcohols...... as well as the noacheese ociated P. expansum have been investigated by electronic nose, GC-MS, and LGMS analysis. The isolates were inoculated on yeast extract sucroseagar in 20-mL headspace flasks and electronicnose analysis was performed daily for a-74period. To assess which volatile metabolites...... by high pressure liquid chromatography, coupled-to a diode array detector and a time of flight mass spectrometer. Several mycotoxins were detected in samples from the specles P.nordicum, P.roqueforti, P.paneum, P.carneum, and P.expansum. Differentiation of closely related mycotoxin producing fungi...

Synthesis of UDP-apiose in Bacteria: The marine phototroph Geminicoccus roseus and the plant pathogen Xanthomonas pisi.

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James Amor Smith

Full Text Available The branched-chain sugar apiose was widely assumed to be synthesized only by plant species. In plants, apiose-containing polysaccharides are found in vascularized plant cell walls as the pectic polymers rhamnogalacturonan II and apiogalacturonan. Apiosylated secondary metabolites are also common in many plant species including ancestral avascular bryophytes and green algae. Apiosyl-residues have not been documented in bacteria. In a screen for new bacterial glycan structures, we detected small amounts of apiose in methanolic extracts of the aerobic phototroph Geminicoccus roseus and the pathogenic soil-dwelling bacteria Xanthomonas pisi. Apiose was also present in the cell pellet of X. pisi. Examination of these bacterial genomes uncovered genes with relatively low protein homology to plant UDP-apiose/UDP-xylose synthase (UAS. Phylogenetic analysis revealed that these bacterial UAS-like homologs belong in a clade distinct to UAS and separated from other nucleotide sugar biosynthetic enzymes. Recombinant expression of three bacterial UAS-like proteins demonstrates that they actively convert UDP-glucuronic acid to UDP-apiose and UDP-xylose. Both UDP-apiose and UDP-xylose were detectable in cell cultures of G. roseus and X. pisi. We could not, however, definitively identify the apiosides made by these bacteria, but the detection of apiosides coupled with the in vivo transcription of bUAS and production of UDP-apiose clearly demonstrate that these microbes have evolved the ability to incorporate apiose into glycans during their lifecycles. While this is the first report to describe enzymes for the formation of activated apiose in bacteria, the advantage of synthesizing apiose-containing glycans in bacteria remains unknown. The characteristics of bUAS and its products are discussed.

Classification of plant associated bacteria using RIF, a computationally derived DNA marker.

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Kevin L Schneider

Full Text Available A DNA marker that distinguishes plant associated bacteria at the species level and below was derived by comparing six sequenced genomes of Xanthomonas, a genus that contains many important phytopathogens. This DNA marker comprises a portion of the dnaA replication initiation factor (RIF. Unlike the rRNA genes, dnaA is a single copy gene in the vast majority of sequenced bacterial genomes, and amplification of RIF requires genus-specific primers. In silico analysis revealed that RIF has equal or greater ability to differentiate closely related species of Xanthomonas than the widely used ribosomal intergenic spacer region (ITS. Furthermore, in a set of 263 Xanthomonas, Ralstonia and Clavibacter strains, the RIF marker was directly sequenced in both directions with a success rate approximately 16% higher than that for ITS. RIF frameworks for Xanthomonas, Ralstonia and Clavibacter were constructed using 682 reference strains representing different species, subspecies, pathovars, races, hosts and geographic regions, and contain a total of 109 different RIF sequences. RIF sequences showed subspecific groupings but did not place strains of X. campestris or X. axonopodis into currently named pathovars nor R. solanacearum strains into their respective races, confirming previous conclusions that pathovar and race designations do not necessarily reflect genetic relationships. The RIF marker also was sequenced for 24 reference strains from three genera in the Enterobacteriaceae: Pectobacterium, Pantoea and Dickeya. RIF sequences of 70 previously uncharacterized strains of Ralstonia, Clavibacter, Pectobacterium and Dickeya matched, or were similar to, those of known reference strains, illustrating the utility of the frameworks to classify bacteria below the species level and rapidly match unknown isolates to reference strains. The RIF sequence frameworks are available at the online RIF database, RIFdb, and can be queried for diagnostic purposes with RIF

Novel intron markers to study the phylogeny of closely related mammalian species

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Castresana Jose

2010-11-01

Full Text Available Abstract Background Multilocus phylogenies can be used to infer the species tree of a group of closely related species. In species trees, the nodes represent the actual separation between species, thus providing essential information about their evolutionary history. In addition, multilocus phylogenies can help in analyses of species delimitation, gene flow and genetic differentiation within species. However, few adequate markers are available for such studies. Results In order to develop nuclear markers that can be useful in multilocus studies of mammals, we analyzed the mammalian genomes of human, chimpanzee, macaque, dog and cow. Rodents were excluded due to their unusual genomic features. Introns were extracted from the mammalian genomes because of their greater genetic variability and ease of amplification from the flanking exons. To an initial set of more than 10,000 one-to-one orthologous introns we applied several filters to select introns that belong to single-copy genes, show neutral evolutionary rates and have an adequate length for their amplification. This analysis led to a final list of 224 intron markers randomly distributed along the genome. To experimentally test their validity, we amplified twelve of these introns in a panel of six mammalian species. The result was that seven of these introns gave rise to a PCR band of the expected size in all species. In addition, we sequenced these bands and analyzed the accumulation of substitutions in these introns in five pairs of closely related species. The results showed that the estimated genetic distances in the five species pairs was quite variable among introns and that this divergence cannot be directly predicted from the overall intron divergence in mammals. Conclusions We have designed a new set of 224 nuclear introns with optimal features for the phylogeny of closely related mammalian species. A large proportion of the introns tested experimentally showed a perfect amplification

Expression, purification, crystallization and preliminary X-ray analysis of YaeQ (XAC2396) from Xanthomonas axonopodis pv. citri

International Nuclear Information System (INIS)

Guzzo, Cristiane R.; Nagem, Ronaldo A. P.; Galvão-Botton, Leonor M. P.; Guimarães, Beatriz G.; Medrano, Francisco J.; Barbosa, João A. R. G.; Farah, Chuck S.

2005-01-01

The first crystallographic study of a member of the YaeQ family of proteins, which are conserved in a small group of Gram-negative bacteria, most of which are animal or plant pathogens, is reported. Diffraction data were collected to 1.9 Å resolution and an interpretable electron-density map was obtained. Xanthomonas axonopodis pv. citri YaeQ (XAC2396) is a member of a family of bacterial proteins conserved in several Gram-negative pathogens. Here, the cloning, expression, purification and crystallization of the 182-residue (20.6 kDa) YaeQ protein are described. Recombinant YaeQ containing selenomethionine was crystallized in space group P2 1 and crystals diffracted to 1.9 Å resolution at a synchrotron source. The unit-cell parameters are a = 39.75, b = 91.88, c = 48.03 Å, β = 108.37°. The calculated Matthews coefficient suggests the presence of two YaeQ molecules in the asymmetric unit. Initial experimental phases were calculated by the multiple-wavelength anomalous dispersion technique and an interpretable electron-density map was obtained

Crystallographic structure and substrate-binding interactions of the molybdate-binding protein of the phytopathogen Xanthomonas axonopodis pv. citri.

Science.gov (United States)

Balan, Andrea; Santacruz-Pérez, Carolina; Moutran, Alexandre; Ferreira, Luís Carlos Souza; Neshich, Goran; Gonçalves Barbosa, João Alexandre Ribeiro

2008-02-01

In Xanthomonas axonopodis pv. citri (Xac or X. citri), the modA gene codes for a periplasmic protein (ModA) that is capable of binding molybdate and tungstate as part of the ABC-type transporter required for the uptake of micronutrients. In this study, we report the crystallographic structure of the Xac ModA protein with bound molybdate. The Xac ModA structure is similar to orthologs with known three-dimensional structures and consists of two nearly symmetrical domains separated by a hinge region where the oxyanion-binding site lies. Phylogenetic analysis of different ModA orthologs based on sequence alignments revealed three groups of molybdate-binding proteins: bacterial phytopathogens, enterobacteria and soil bacteria. Even though the ModA orthologs are segregated into different groups, the ligand-binding hydrogen bonds are mostly conserved, except for Archaeglobus fulgidus ModA. A detailed discussion of hydrophobic interactions in the active site is presented and two new residues, Ala38 and Ser151, are shown to be part of the ligand-binding pocket.

Differences in mating strategies in two closely related small ermine moth species (Lepidoptera: Yponomeutidae)

NARCIS (Netherlands)

Bakker, A.C.; van Ginkel, W.E.; Roessingh, P.; Menken, S.B.J.

2008-01-01

The degree of polyandry in a species is linked to other life history traits such as egg maturation, life span, and male ejaculate size and quality. The study of differences in mating strategies between closely related species can provide a better understanding of the evolution of these strategies

Phylogeny Inference of Closely Related Bacterial Genomes: Combining the Features of Both Overlapping Genes and Collinear Genomic Regions

Science.gov (United States)

Zhang, Yan-Cong; Lin, Kui

2015-01-01

Overlapping genes (OGs) represent one type of widespread genomic feature in bacterial genomes and have been used as rare genomic markers in phylogeny inference of closely related bacterial species. However, the inference may experience a decrease in performance for phylogenomic analysis of too closely or too distantly related genomes. Another drawback of OGs as phylogenetic markers is that they usually take little account of the effects of genomic rearrangement on the similarity estimation, such as intra-chromosome/genome translocations, horizontal gene transfer, and gene losses. To explore such effects on the accuracy of phylogeny reconstruction, we combine phylogenetic signals of OGs with collinear genomic regions, here called locally collinear blocks (LCBs). By putting these together, we refine our previous metric of pairwise similarity between two closely related bacterial genomes. As a case study, we used this new method to reconstruct the phylogenies of 88 Enterobacteriale genomes of the class Gammaproteobacteria. Our results demonstrated that the topological accuracy of the inferred phylogeny was improved when both OGs and LCBs were simultaneously considered, suggesting that combining these two phylogenetic markers may reduce, to some extent, the influence of gene loss on phylogeny inference. Such phylogenomic studies, we believe, will help us to explore a more effective approach to increasing the robustness of phylogeny reconstruction of closely related bacterial organisms. PMID:26715828

Genetic basis of hybrid male sterility among three closely related species of Drosophila.

Science.gov (United States)

Mishra, Paras Kumar; Singh, B N

2005-05-01

The genetic basis of hybrid male sterility among three closely related species, Drosophila bipectinata, D. parabipectinata and D. malerkotliana has been investigated by using backcross analysis methods. The role of Y chromosome, major hybrid sterility (MHS) genes (genetic factors) and cytoplasm (non-genetic factor) have been studied in the hybrids of these three species. In the species pair, bipectinata--parabipectinata, Y chromosome introgression of parabipectinata in the genomic background of bipectinata and the reciprocal Y chromosome introgression were unsuccessful as all males in second backcross generation were sterile. Neither MHS genes nor cytoplasm was found important for sterility. This suggests the involvement of X-Y, X-autosomes or polygenic interactions in hybrid male sterility. In bipectinata--malerkotliana and parabipectinata--malerkotliana species pairs, Y chromosome substitution in reciprocal crosses did not affect male fertility. Backcross analyses also show no involvement of MHS genes or cytoplasm in hybrid male sterility in these two species pairs. Therefore, X- autosome interaction or polygenic interaction is supposed to be involved in hybrid male sterility in these two species pairs. These findings also provide evidence that even in closely related species, genetic interactions underlying hybrid male sterility may vary.

Family Communication Patterns and Relational Maintenance Behavior: Direct and Mediated Associations with Friendship Closeness

Science.gov (United States)

Ledbetter, Andrew M.

2009-01-01

In this study, both face-to-face and online relational maintenance behaviors were tested as mediators of family communication patterns and closeness with a same-sex friend. Participants included 417 young adults recruited from communication courses at a large university in the Midwestern United States. The obtained structural model demonstrated…

Preparation, crystallization and preliminary X-ray analysis of XC2382, an ApaG protein of unknown structure from Xanthomonas campestris

International Nuclear Information System (INIS)

Chin, Ko-Hsin; Chou, Chia-Cheng; Lee, Cheng-Chung; Shr, Hui-Lin; Lyu, Ping-Chiang; Wang, Andrew H.-J.; Chou, Shan-Ho

2005-01-01

A putative ApaG gene product from X. campestris pv. campestris was overexpressed in E. coli, purified and crystallized. The crystals diffracted to a resolution of at least 2.3 Å. Xanthomonas campestris pv. campestris is the causative agent of black rot, one of the major worldwide diseases of cruciferous crops. Its genome encodes approximately 4500 proteins, roughly one third of which have unknown function. XC2382 is one such protein, with a MW of 14.2 kDa. Based on a bioinformatics study, it was annotated as an ApaG gene product that serves multiple functions. The ApaG protein has been overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of at least 2.30 Å. They are tetragonal and belong to space group P4 1/3 , with unit-cell parameters a = b = 57.6, c = 122.9 Å. There are two, three or four molecules in the asymmetric unit

Biological Functions of ilvC in Branched-Chain Fatty Acid Synthesis and Diffusible Signal Factor Family Production in Xanthomonas campestris

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Kai-Huai Li

2017-12-01

Full Text Available In bacteria, the metabolism of branched-chain amino acids (BCAAs is tightly associated with branched-chain fatty acids (BCFAs synthetic pathways. Although previous studies have reported on BCFAs biosynthesis, more detailed associations between BCAAs metabolism and BCFAs biosynthesis remain to be addressed. In this study, we deleted the ilvC gene, which encodes ketol-acid reductoisomerase in the BCAAs synthetic pathway, from the Xanthomonas campestris pv. campestris (Xcc genome. We characterized gene functions in BCFAs biosynthesis and production of the diffusible signal factor (DSF family signals. Disruption of ilvC caused Xcc to become auxotrophic for valine and isoleucine, and lose the ability to synthesize BCFAs via carbohydrate metabolism. Furthermore, ilvC mutant reduced the ability to produce DSF-family signals, especially branched-chain DSF-family signals, which might be the main reason for Xcc reduction of pathogenesis toward host plants. In this report, we confirmed that BCFAs do not have major functions in acclimatizing Xcc cells to low temperatures.

Analysis of outer membrane vesicle associated proteins isolated from the plant pathogenic bacterium Xanthomonas campestris pv. campestris

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Niehaus Karsten

2008-06-01

Full Text Available Abstract Background Outer membrane vesicles (OMVs are released from the outer membrane of many Gram-negative bacteria. These extracellular compartments are known to transport compounds involved in cell-cell signalling as well as virulence associated proteins, e.g. the cytolysine from enterotoxic E. coli. Results We have demonstrated that Xanthomonas campestris pv. campestris (Xcc releases OMVs into the culture supernatant during growth. A proteome study identified 31 different proteins that associate with the OMV fraction of which half are virulence-associated. A comparison with the most abundant outer membrane (OM proteins revealed that some proteins are enriched in the OMV fraction. This may be connected to differences in the LPS composition between the OMVs and the OM. Furthermore, a comparison of the OMV proteomes from two different culture media indicated that the culture conditions have an impact on the protein composition. Interestingly, the proteins that are common to both culture conditions are mainly involved in virulence. Conclusion Outer membrane vesicles released from the OM of Xcc contain membrane- and virulence-associated proteins. Future experiments will prove whether these structures can serve as "vehicles" for the transport of virulence factors into the host membrane.

Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

Science.gov (United States)

Blair, Jaime E; Coffey, Michael D; Martin, Frank N

2012-01-01

To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria.

Science.gov (United States)

Yim, W J; Kim, K Y; Lee, Y W; Sundaram, S P; Lee, Y; Sa, T M

2014-07-15

Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato. Copyright © 2014 Elsevier GmbH. All rights reserved.

Genetic diversity of Xanthomonas axonopodis pv. citri based on plasmid profile and pulsed field gel electrophoresis

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Carvalho Flávia Maria de Souza

2005-01-01

Full Text Available Xanthomonas axonopodis pv. citri strains that cause disease in citrus were investigated by pulsed field and plasmid profile analysis. For the first method, genomic DNA was digested by the rare-cutting enzymes Xba I and Vsp I. The strains evaluated were collected in seven different States of Brazil and in Argentina, Bolivia, Paraguay and Uruguay. Genetic variability was found among strains of X. axonopodis pv. citri from different geographical areas Argentina, Bolivia and Uruguay, with similarities varying from 0.62 to 0.83. However, the strains collected in Brazil, despite being from different States, have shown a genetic similarity ranging from 0.83 to 1.00. Cluster analysis showed a relationship between genomic similarity and geographical origin of the strains. Plasmids were observed in all strains, with a total of five different plasmids, with sizes between 57.7 and 83.0 kilobases. The 72.6 kb plasmid was the most frequent, present in 15 out of 22 strains, while the 68.1 kb plasmid was observed in two strains only. Although the plasmid diversity detected in the present study was not very great, the X. axonopodis pv. citri strains evaluated showed a considerable degree of diversity with regard to this extrachromosomal genetic element.

Artificial light at night affects sleep behaviour differently in two closely related songbird species.

Science.gov (United States)

Sun, Jiachen; Raap, Thomas; Pinxten, Rianne; Eens, Marcel

2017-12-01

Artificial light at night (ALAN) or light pollution is an increasing and worldwide problem. There is growing concern that because of the disruption of natural light cycles, ALAN may pose serious risks for wildlife. While ALAN has been shown to affect many aspects of animal behaviour and physiology, few studies have experimentally studied whether individuals of different species in the wild respond differently to ALAN. Here, we investigated the effect of ALAN on sleep behaviour in two closely related songbird species inhabiting the same study area and roosting/breeding in similar nest boxes. We experimentally exposed free-living great tits (Parus major) and blue tits (Cyanistes caeruleus) to artificial light inside their nest boxes and observed changes in their sleep behaviour compared to the previous night when the nest boxes were dark. In line with previous studies, sleep behaviour of both species did not differ under dark conditions. ALAN disrupted sleep in both great and blue tits. However, compared to blue tits, great tits showed more pronounced effects and more aspects of sleep were affected. Light exposed great tits entered the nest boxes and fell asleep later, woke up and exited the nest boxes earlier, and the total sleep amount and sleep percentage were reduced. By contrast, these changes in sleep behaviour were not found in light exposed blue tits. Our field experiment, using exactly the same light manipulation in both species, provides direct evidence that two closely related species respond differently to ALAN, while their sleep behaviour under dark conditions was similar. Our research suggests that findings for one species cannot necessarily be generalised to other species, even closely-related species. Furthermore, species-specific effects could have implications for community dynamics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interspecific competition, predation, and the coexistence of three closely related neotropical armoured catfishes (Siluriformes - Callichthyidae)

NARCIS (Netherlands)

Mol, J.H.A.

1995-01-01

Tropical ecosystems are renowned for their high biodiversity with many closely related species living together. Alpha diversity of tropical freshwater fishes is also extremely high, as exemplified by the cichlid fauna of the Great African lakes and the neotropical characins. Since

Elucidation of Operon Structures across Closely Related Bacterial Genomes

Science.gov (United States)

Li, Guojun

2014-01-01

About half of the protein-coding genes in prokaryotic genomes are organized into operons to facilitate co-regulation during transcription. With the evolution of genomes, operon structures are undergoing changes which could coordinate diverse gene expression patterns in response to various stimuli during the life cycle of a bacterial cell. Here we developed a graph-based model to elucidate the diversity of operon structures across a set of closely related bacterial genomes. In the constructed graph, each node represents one orthologous gene group (OGG) and a pair of nodes will be connected if any two genes, from the corresponding two OGGs respectively, are located in the same operon as immediate neighbors in any of the considered genomes. Through identifying the connected components in the above graph, we found that genes in a connected component are likely to be functionally related and these identified components tend to form treelike topology, such as paths and stars, corresponding to different biological mechanisms in transcriptional regulation as follows. Specifically, (i) a path-structure component integrates genes encoding a protein complex, such as ribosome; and (ii) a star-structure component not only groups related genes together, but also reflects the key functional roles of the central node of this component, such as the ABC transporter with a transporter permease and substrate-binding proteins surrounding it. Most interestingly, the genes from organisms with highly diverse living environments, i.e., biomass degraders and animal pathogens of clostridia in our study, can be clearly classified into different topological groups on some connected components. PMID:24959722

The type III protein secretion system contributes to Xanthomonas citri subsp. citri biofilm formation

KAUST Repository

Zimaro, Tamara

2014-04-18

Background: Several bacterial plant pathogens colonize their hosts through the secretion of effector proteins by a Type III protein secretion system (T3SS). The role of T3SS in bacterial pathogenesis is well established but whether this system is involved in multicellular processes, such as bacterial biofilm formation has not been elucidated. Here, the phytopathogen Xanthomonas citri subsp. citri (X. citri) was used as a model to gain further insights about the role of the T3SS in biofilm formation. Results: The capacity of biofilm formation of different X. citri T3SS mutants was compared to the wild type strain and it was observed that this secretion system was necessary for this process. Moreover, the T3SS mutants adhered proficiently to leaf surfaces but were impaired in leaf-associated growth. A proteomic study of biofilm cells showed that the lack of the T3SS causes changes in the expression of proteins involved in metabolic processes, energy generation, exopolysaccharide (EPS) production and bacterial motility as well as outer membrane proteins. Furthermore, EPS production and bacterial motility were also altered in the T3SS mutants. Conclusions: Our results indicate a novel role for T3SS in X. citri in the modulation of biofilm formation. Since this process increases X. citri virulence, this study reveals new functions of T3SS in pathogenesis. 2014 Zimaro et al.; licensee BioMed Central Ltd.

Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

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Da-Ran Kim

2016-08-01

Full Text Available Strawberry bacterial angular leaf spot (ALS disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are 20°C and the pathogen suffers mortality above 32°C. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August, the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%. To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

Relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae).

Science.gov (United States)

Blasina, Gabriela; Molina, Juan; Lopez Cazorla, Andrea; Díaz de Astarloa, Juan

This study explores the relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae) that are known to differ in their trophic habits. Only adult specimens were analyzed: 103 Cynoscion guatucupa, 77 Pogonias cromis, 61 Micropogonias furnieri, and 48 Menticirrhus americanus. The four species presented divergent ecomorphological traits related to swimming agility, prey spotting and capture, and the potential size of prey they were able to swallow. Results suggest that these sciaenid species can partition the food resources, even though they completely overlap in space. Differences in their ecomorphological traits appear to correlate closely with the diet and consequently could explain the trophic differentiation observed. Arguably, these ecomorphological differences play a significant role in the coexistence of the adults of these sympatric fish species. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Inhibition of Xanthomonas fragariae, Causative Agent of Angular Leaf Spot of Strawberry, through Iron Deprivation

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Peter Henry

2016-10-01

Full Text Available In commercial production settings, few options exist to prevent or treat angular leaf spot of strawberry, a disease of economic importance and caused by the bacterial pathogen Xanthomonas fragariae (Xfr. In the process of isolating and identifying Xfr bacteria from symptomatic plants, we observed growth inhibition of Xfr by bacterial isolates from the same leaf macerates. Identified as species of Pseudomonas and Rhizobium, these isolates were confirmed to suppress growth of Xfr in agar overlay plates and in microtiter plate cultures, as did our reference strain Pseudomonas putida KT2440. Screening of a transposon mutant library of KT2440 revealed that disruption of the biosynthetic pathway for the siderophore pyoverdine resulted in complete loss of Xfr antagonism, suggesting iron competition as a mode of action. Antagonism could be replicated on plate and in culture by addition of purified pyoverdine or by addition of the chelating agents tannic acid and dipyridyl, while supplementing the medium with iron negated the inhibitory effects of pyoverdine, tannic acid and dipyridyl. When co-inoculated with tannic acid onto strawberry plants, Xfr’s ability to cause foliar symptoms was greatly reduced, suggesting a possible opportunity for iron-based management of angular leaf spot. We discuss our findings in the context of ‘nutritional immunity’, the idea that plant hosts restrict pathogens access to iron, either directly, or indirectly through their associated microbiota.

The Pathogenomic Sequence Analysis of B. cereus and B.thuringiensis Isolates Closely Related to Bacillus anthracis

Energy Technology Data Exchange (ETDEWEB)

Han, Cliff S.; Xie, Gary; Challacombe, Jean F.; Altherr, MichaelR.; Smriti, B.; Bruce, David; Campbell, Connie S.; Campbell, Mary L.; Chen, Jin; Chertkov, Olga; Cleland, Cathy; Dimitrijevic-Bussod, M.; Doggett, Norman A.; Fawcett, John J.; Glavina, Tijana; Goodwin, Lynne A.; Hill, Karen K.; Hitchcock, Penny; Jackson, Paul J.; Keim, Paul; Kewalramani, Avinash Ramesh; Longmire, Jon; Lucas, Susan; Malfatti,Stephanie; McMurry, Kim; Meincke, Linda J.; Misra, Monica; Moseman,Bernice L.; Mundt, Mark; Munk, A. Christine; Okinaka, Richard T.; Parson-Quintana, B.; Reilly, Lee P.; Richardson, Paul; Robinson, DonnaL.; Rubin, Eddy; Saunders, Elizabeth; Tapia, Roxanne; Tesmer, Judith G.; Thayer, Nina; Thompson, Linda S.; Tice, Hope; Ticknor, Lawrence O.; Wills, Patti L.; Gilna, Payl; Brettin, Thomas S.

2005-08-18

The sequencing and analysis of two close relatives of Bacillus anthracis are reported. AFLP analysis of over 300 isolates of B.cereus, B. thuringiensis and B. anthracis identified two isolates as being very closely related to B. anthracis. One, a B. cereus, BcE33L, was isolated from a zebra carcass in Nambia; the second, a B. thuringiensis, 97-27, was isolated from a necrotic human wound. The B. cereus appears to be the closest anthracis relative sequenced to date. A core genome of over 3,900 genes was compiled for the Bacillus cereus group, including Banthracis. Comparative analysis of these two genomes with other members of the B. cereus group provides insight into the evolutionary relationships among these organisms. Evidence is presented that differential regulation modulates virulence, rather than simple acquisition of virulence factors. These genome sequences provide insight into the molecular mechanisms contributing to the host range and virulence of this group of organisms.

Influência da natureza do rejeito agroindustrial fermentado por Xanthomonas axonopodis pv. manihotis nas propriedades das gomas xantana resultantes

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Denilson de Jesus Assis

2014-01-01

Full Text Available Um destino para resíduos agro-industriais é usá-los como substratos fermentescíveis, diminuindo o custo na produção de produtos com alto valor agregado. Este trabalho avaliou a influência da natureza dos resíduos fermentescíveis e das cepas de Xanthomonas sobre a produção e propriedades do biopolímero resultante. A produção foi realizada em agitador orbital (250 rpm / 28 °C / 120 h por fermentação de sacarose (controle, glicerina residual do biodiesel e resíduo líquido de sisal. Tanto a composição do substrato como as cepas mostraram um forte efeito sobre a produção (0,36-2,40 gL- 1, viscosidade aparente (13,73 para 36,31 mPa.s e massa molecular (2,1-5,9 × 10(6 Da da goma de xantana resultante, não influenciando o comportamento pseudoplástico de soluções aquosas dos biopolímeros.

Species tree estimation for the late blight pathogen, Phytophthora infestans, and close relatives.

Directory of Open Access Journals (Sweden)

Jaime E Blair

Full Text Available To better understand the evolutionary history of a group of organisms, an accurate estimate of the species phylogeny must be known. Traditionally, gene trees have served as a proxy for the species tree, although it was acknowledged early on that these trees represented different evolutionary processes. Discordances among gene trees and between the gene trees and the species tree are also expected in closely related species that have rapidly diverged, due to processes such as the incomplete sorting of ancestral polymorphisms. Recently, methods have been developed for the explicit estimation of species trees, using information from multilocus gene trees while accommodating heterogeneity among them. Here we have used three distinct approaches to estimate the species tree for five Phytophthora pathogens, including P. infestans, the causal agent of late blight disease in potato and tomato. Our concatenation-based "supergene" approach was unable to resolve relationships even with data from both the nuclear and mitochondrial genomes, and from multiple isolates per species. Our multispecies coalescent approach using both Bayesian and maximum likelihood methods was able to estimate a moderately supported species tree showing a close relationship among P. infestans, P. andina, and P. ipomoeae. The topology of the species tree was also identical to the dominant phylogenetic history estimated in our third approach, Bayesian concordance analysis. Our results support previous suggestions that P. andina is a hybrid species, with P. infestans representing one parental lineage. The other parental lineage is not known, but represents an independent evolutionary lineage more closely related to P. ipomoeae. While all five species likely originated in the New World, further study is needed to determine when and under what conditions this hybridization event may have occurred.

Non-coding changes cause sex-specific wing size differences between closely related species of Nasonia

NARCIS (Netherlands)

Loehlin, David W.; Oliveira, Deodoro C. S. G.; Edwards, Rachel; Giebel, Jonathan D.; Clark, Michael E.; Cattani, M. Victoria; van de Zande, Louis; Verhulst, Eveline C.; Beukeboom, Leo W.; Munoz-Torres, Monica; Werren, John H.

The genetic basis of morphological differences among species is still poorly understood. We investigated the genetic basis of sex-specific differences in wing size between two closely related species of Nasonia by positional cloning a major male-specific locus, wing-size1 (ws1). Male wing size

The Xanthomonas Ax21 protein is processed by the general secretory system and is secreted in association with outer membrane vesicles

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Ofir Bahar

2014-01-01

Full Text Available Pattern recognition receptors (PRRs play an important role in detecting invading pathogens and mounting a robust defense response to restrict infection. In rice, one of the best characterized PRRs is XA21, a leucine rich repeat receptor-like kinase that confers broad-spectrum resistance to multiple strains of the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo. In 2009 we reported that an Xoo protein, called Ax21, is secreted by a type I-secretion system and that it serves to activate XA21-mediated immunity. This report has recently been retracted. Here we present data that corrects our previous model. We first show that Ax21 secretion does not depend on the predicted type I secretion system and that it is processed by the general secretion (Sec system. We further show that Ax21 is an outer membrane protein, secreted in association with outer membrane vesicles. Finally, we provide data showing that ax21 knockout strains do not overcome XA21-mediated immunity.

Production of inulinase by Xanthomonas campestris pv phaseoli using onion (Allium cepa) and garlic (Allium sativum) peels in solid state cultivation.

Science.gov (United States)

Ayyachamy, M; Khelawan, K; Pillay, D; Permaul, K; Singh, S

2007-10-01

To access inulinase production by Xanthomonas campestris pv phaseoli using the submerged and solid state cultivation (SSC) methods. Various carbon sources, inulin-rich solid substrates and pure synthetic inulin were tested for their efficiency in inulinase induction. The highest inulinase production (17.42 IU ml(-1)) in submerged cultures of X. campestris was observed with inulin as a carbon source with an initial pH, temperature and agitation of 7.0, 37 degrees C and 150 rev min(-1) respectively. Among the various substrates, garlic peels (117 IU gds(-1)) and onion peels (101 IU gds(-1)) were found to be the best for inulinase production. The inulinase production level of X. campestris was 6.7-fold higher in garlic and 5.8-fold in onion, under optimized SSC conditions compared with the submerged culture. This is the first report on inulinase production from garlic and onion peels by X. campestris using SSC. SSC is an efficient method for inulinase production by X. campestris for commercial applications.

A Murine Herpesvirus Closely Related to Ubiquitous Human Herpesviruses Causes T-Cell Depletion.

Science.gov (United States)

Patel, Swapneel J; Zhao, Guoyan; Penna, Vinay R; Park, Eugene; Lauron, Elvin J; Harvey, Ian B; Beatty, Wandy L; Plougastel-Douglas, Beatrice; Poursine-Laurent, Jennifer; Fremont, Daved H; Wang, David; Yokoyama, Wayne M

2017-05-01

The human roseoloviruses human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 comprise the Roseolovirus genus of the human Betaherpesvirinae subfamily. Infections with these viruses have been implicated in many diseases; however, it has been challenging to establish infections with roseoloviruses as direct drivers of pathology, because they are nearly ubiquitous and display species-specific tropism. Furthermore, controlled study of infection has been hampered by the lack of experimental models, and until now, a mouse roseolovirus has not been identified. Herein we describe a virus that causes severe thymic necrosis in neonatal mice, characterized by a loss of CD4 + T cells. These phenotypes resemble those caused by the previously described mouse thymic virus (MTV), a putative herpesvirus that has not been molecularly characterized. By next-generation sequencing of infected tissue homogenates, we assembled a contiguous 174-kb genome sequence containing 128 unique predicted open reading frames (ORFs), many of which were most closely related to herpesvirus genes. Moreover, the structure of the virus genome and phylogenetic analysis of multiple genes strongly suggested that this virus is a betaherpesvirus more closely related to the roseoloviruses, HHV-6A, HHV-6B, and HHV-7, than to another murine betaherpesvirus, mouse cytomegalovirus (MCMV). As such, we have named this virus murine roseolovirus (MRV) because these data strongly suggest that MRV is a mouse homolog of HHV-6A, HHV-6B, and HHV-7. IMPORTANCE Herein we describe the complete genome sequence of a novel murine herpesvirus. By sequence and phylogenetic analyses, we show that it is a betaherpesvirus most closely related to the roseoloviruses, human herpesviruses 6A, 6B, and 7. These data combined with physiological similarities with human roseoloviruses collectively suggest that this virus is a murine roseolovirus (MRV), the first definitively described rodent roseolovirus, to our knowledge. Many biological and

Integrative analysis of single nucleotide polymorphisms and gene expression efficiently distinguishes samples from closely related ethnic populations

Directory of Open Access Journals (Sweden)

Yang Hsin-Chou

2012-07-01

Full Text Available Abstract Background Ancestry informative markers (AIMs are a type of genetic marker that is informative for tracing the ancestral ethnicity of individuals. Application of AIMs has gained substantial attention in population genetics, forensic sciences, and medical genetics. Single nucleotide polymorphisms (SNPs, the materials of AIMs, are useful for classifying individuals from distinct continental origins but cannot discriminate individuals with subtle genetic differences from closely related ancestral lineages. Proof-of-principle studies have shown that gene expression (GE also is a heritable human variation that exhibits differential intensity distributions among ethnic groups. GE supplies ethnic information supplemental to SNPs; this motivated us to integrate SNP and GE markers to construct AIM panels with a reduced number of required markers and provide high accuracy in ancestry inference. Few studies in the literature have considered GE in this aspect, and none have integrated SNP and GE markers to aid classification of samples from closely related ethnic populations. Results We integrated a forward variable selection procedure into flexible discriminant analysis to identify key SNP and/or GE markers with the highest cross-validation prediction accuracy. By analyzing genome-wide SNP and/or GE markers in 210 independent samples from four ethnic groups in the HapMap II Project, we found that average testing accuracies for a majority of classification analyses were quite high, except for SNP-only analyses that were performed to discern study samples containing individuals from two close Asian populations. The average testing accuracies ranged from 0.53 to 0.79 for SNP-only analyses and increased to around 0.90 when GE markers were integrated together with SNP markers for the classification of samples from closely related Asian populations. Compared to GE-only analyses, integrative analyses of SNP and GE markers showed comparable testing

Cognitive functioning is more closely related to real-life mobility than to laboratory-based mobility parameters

NARCIS (Netherlands)

Giannouli, Eleftheria; Bock, Otmar; Zijlstra, Wiebren

2018-01-01

Increasing evidence indicates that mobility depends on cognitive resources, but the exact relationships between various cognitive functions and different mobility parameters still need to be investigated. This study examines the hypothesis that cognitive functioning is more closely related to

Co-regulation of Iron Metabolism and Virulence Associated Functions by Iron and XibR, a Novel Iron Binding Transcription Factor, in the Plant Pathogen Xanthomonas.

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Sheo Shankar Pandey

2016-11-01

Full Text Available Abilities of bacterial pathogens to adapt to the iron limitation present in hosts is critical to their virulence. Bacterial pathogens have evolved diverse strategies to coordinately regulate iron metabolism and virulence associated functions to maintain iron homeostasis in response to changing iron availability in the environment. In many bacteria the ferric uptake regulator (Fur functions as transcription factor that utilize ferrous form of iron as cofactor to regulate transcription of iron metabolism and many cellular functions. However, mechanisms of fine-tuning and coordinated regulation of virulence associated function beyond iron and Fur-Fe2+ remain undefined. In this study, we show that a novel transcriptional regulator XibR (named Xanthomonas iron binding regulator of the NtrC family, is required for fine-tuning and co-coordinately regulating the expression of several iron regulated genes and virulence associated functions in phytopathogen Xanthomonas campestris pv. campestris (Xcc. Genome wide expression analysis of iron-starvation stimulon and XibR regulon, GUS assays, genetic and functional studies of xibR mutant revealed that XibR positively regulates functions involved in iron storage and uptake, chemotaxis, motility and negatively regulates siderophore production, in response to iron. Furthermore, chromatin immunoprecipitation followed by quantitative real-time PCR indicated that iron promoted binding of the XibR to the upstream regulatory sequence of operon's involved in chemotaxis and motility. Circular dichroism spectroscopy showed that purified XibR bound ferric form of iron. Electrophoretic mobility shift assay revealed that iron positively affected the binding of XibR to the upstream regulatory sequences of the target virulence genes, an effect that was reversed by ferric iron chelator deferoxamine. Taken together, these data revealed that how XibR coordinately regulates virulence associated and iron metabolism functions in

Influence of agitation and aeration in xanthan production by Xanthomonas campestris pv pruni strain 101 Influencia de la agitación y la aireación en la producción de xantano por Xanthomonas campestris pv. pruni cepa 101

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C. D. Borges

2008-06-01

Full Text Available Production, viscosity, and chemical composition of xanthan synthesized by bacterium Xanthomonas campestris pv pruni strain 101 were evaluated in bioreactor systems. During the process, the volumetric oxygen mass transfer coefficient (kLa and the biomass were determined and the pH was monitored. The cultures were grown in a 3 l bioreactor, with aeration and agitation varying as follows: conditions (A 300 rpm, 3 vvm and (B 200 rpm, 2 vvm, at 28 °C. Our results showed that gum production was dependent on kLa, with a maximum yield of 8.15 g/l at 300 rpm, 3 vvm, 54 h of fermentation, kLa 21.4/h, while biomass was not affected. All aqueous solutions of 3% (w/v xanthans synthesized showed a pseudoplastic behavior. The highest viscosity was reached under the strongest aeration/agitation conditions. All xanthan samples contained glucose, mannose, rhamnose, and glucuronic acid as their main components. The highest agitation and aeration rates used under condition A (300 rpm and 3 vvm favorably influenced the yield and viscosity of the xanthan produced by bacterium X. campestris pv pruni 101 at different fermentation times.Se evaluó la producción, viscosidad y composición química del xantano sintetizado por la bacteria Xanthomonas campestris pv. pruni cepa 101 en un fermentador. Durante el proceso se controló el pH y se determinaron el coeficiente de transferencia de masa de oxígeno (kLa y la producción de masa celular seca. Los cultivos se realizaron en un fermentador de 3 l variando la aireación y la agitación, en las siguientes condiciones: (A 300 rpm, 3 vvm y (B 200 rpm, 2 vvm; a 28 °C. Nuestros resultados mostraron que la producción de goma fue dependiente del kLa, con un rendimiento máximo de 8,15 g/l a 300 rpm y 3 vvm a las 54 h de fermentación, kLa de 21,4/h, mientras que la producción de biomasa no se afectó. Todas las soluciones acuosas de xantano al 3% (m/v sintetizadas presentaron comportamiento pseudoplástico. La mayor

Legal questions relating to nuclear installations close to national frontiers

International Nuclear Information System (INIS)

Zieger, G.

1983-01-01

Main emphasis is placed on the criteria to decide whether the construction and operation of a nulcear power plant close to a national frontier is permissible or not. The author discusses the relevant provisions of the international law and those of the Treaty of Rome pertaining to the settlement of conflicts between neighbour states. According to the opinion of the author, nuclear installations close to borders are incompatible with international law only if they do not comply with accepted safety standards. The international agreements do not prohibit the construction of nuclear installations close to frontiers. It would be desirable, however, the author says, to conclude international treaties providing for mutual consultation and information, thus offering a platform for discussing controversial national interests; this idea already being put into practice in customary international law. (WB) [de

Pipe closing device

International Nuclear Information System (INIS)

Klahn, F.C.; Nolan, J.H.; Wills, C.

1979-01-01

The closing device closes the upper end of a support tube for monitoring samples. It meshes with the upper connecting piece of the monitorung sample capsule, and loads the capsule within the bore of the support tube, so that it is fixed but can be released. The closing device consists of an interlocking component with a chamber and several ratchets which hang down. The interlocking component surrounds the actuating component for positioning the ratchets. The interlocking and actuating components are movable axially relative to each other. (DG) [de

Using the concept of pseudo amino acid composition to predict resistance gene against Xanthomonas oryzae pv. oryzae in rice: an approach from chaos games representation.

Science.gov (United States)

Jingbo, Xia; Silan, Zhang; Feng, Shi; Huijuan, Xiong; Xuehai, Hu; Xiaohui, Niu; Zhi, Li

2011-09-07

To evaluate the possibility of an unknown protein to be a resistant gene against Xanthomonas oryzae pv. oryzae, a different mode of pseudo amino acid composition (PseAAC) is proposed to formulate the protein samples by integrating the amino acid composition, as well as the Chaos games representation (CGR) method. Some numerical comparisons of triangle, quadrangle and 12-vertex polygon CGR are carried to evaluate the efficiency of using these fractal figures in classifiers. The numerical results show that among the three polygon methods, triangle method owns a good fractal visualization and performs the best in the classifier construction. By using triangle + 12-vertex polygon CGR as the mathematical feature, the classifier achieves 98.13% in Jackknife test and MCC achieves 0.8462. Copyright © 2011 Elsevier Ltd. All rights reserved.

Embarrassment When Illness Strikes A Close Relative: A World Mental Health Survey Consortium Multi-Site Study

Science.gov (United States)

Ahmedani, Brian K.; Kubiak, Sheryl Pimlott; Kessler, Ronald C.; de Graaf, Ron; Alonso, Jordi; Bruffaerts, Ronny; Zarkov, Zahari; Viana, Maria Carmen; Huang, Y.Q.; Hu, Chiyi; Posada-Villa, Jose A.; Lepine, Jean-Pierre; Angermeyer, Matthias C.; de Girolamo, Giovanni; Karam, Aimee N.; Medina-Mora, Maria Elena; Gureje, Oye; Ferry, Finola; Sagar, Rajesh; Anthony, James C.

2014-01-01

Background This global study seeks to estimate the degree to which a family member might feel embarrassed when a close relative is suffering from an alcohol, drug, or mental health condition (ADMC) versus a general medical condition (GMC). To date, most studies have considered embarrassment and stigma in society and internalized by the afflicted individual, but have not assessed family embarrassment in a large scale study. Method In 16 sites of the World Mental Health Surveys (WMHS), standardized assessments were completed including items on family embarrassment. Site matching was used to constrain local socially shared determinants of stigma-related feelings, enabling a conditional logistic regression model that estimates the embarrassment close relatives may hold in relation to family members affected by an ADMC, GMC, or both conditions. Results There was a statistically robust association such that subgroups with an ADMC-affected relative were more likely to feel embarrassed as compared to subgroups with a relative affected by a GMC (p<0.001), even with covariate adjustments for age and sex. Conclusions The pattern of evidence from this research is consistent with conceptual models for interventions that target individual- and family-level stigma-related feelings of embarrassment as might be part of the obstacles to effective early intervention and treatment for ADMC conditions. Macro-level interventions are underway, but micro-level interventions also may be required among family members, along with care for each person with an ADMC. PMID:23298443

Calcium signaling in closely related protozoan groups (Alveolata): non-parasitic ciliates (Paramecium, Tetrahymena) vs. parasitic Apicomplexa (Plasmodium, Toxoplasma).

Science.gov (United States)

Plattner, H; Sehring, I M; Mohamed, I K; Miranda, K; De Souza, W; Billington, R; Genazzani, A; Ladenburger, E-M

2012-05-01

The importance of Ca2+-signaling for many subcellular processes is well established in higher eukaryotes, whereas information about protozoa is restricted. Recent genome analyses have stimulated such work also with Alveolates, such as ciliates (Paramecium, Tetrahymena) and their pathogenic close relatives, the Apicomplexa (Plasmodium, Toxoplasma). Here we compare Ca2+ signaling in the two closely related groups. Acidic Ca2+ stores have been characterized in detail in Apicomplexa, but hardly in ciliates. Two-pore channels engaged in Ca2+-release from acidic stores in higher eukaryotes have not been stingently characterized in either group. Both groups are endowed with plasma membrane- and endoplasmic reticulum-type Ca2+-ATPases (PMCA, SERCA), respectively. Only recently was it possible to identify in Paramecium a number of homologs of ryanodine and inositol 1,3,4-trisphosphate receptors (RyR, IP3R) and to localize them to widely different organelles participating in vesicle trafficking. For Apicomplexa, physiological experiments suggest the presence of related channels although their identity remains elusive. In Paramecium, IP3Rs are constitutively active in the contractile vacuole complex; RyR-related channels in alveolar sacs are activated during exocytosis stimulation, whereas in the parasites the homologous structure (inner membrane complex) may no longer function as a Ca2+ store. Scrutinized comparison of the two closely related protozoan phyla may stimulate further work and elucidate adaptation to parasitic life. See also "Conclusions" section. Copyright © 2012 Elsevier Ltd. All rights reserved.

Disease Development and Symptom Expression of Xanthomonas axonopodis pv. citri in Various Citrus Plant Tissues.

Science.gov (United States)

Vernière, C J; Gottwald, T R; Pruvost, O

2003-07-01

ABSTRACT Experimental inoculations of Xanthomonas axonopodis pv. citri in different tissues of Tahiti lime and Pineapple sweet orange were conducted monthly under natural conditions on Réunion Island. The interactions between a set of environmental and epidemic variables associated with disease expression and 184 different factor combinations were investigated to determine the parameters needed to explain Asiatic citrus canker (ACC) disease expression. Area under the disease progress curve (AUDPC), inoculation date (Id), fruit and leaf age ratings (FAR and LAR), and number of days during the first 2 weeks postinoculation for which the temperature was less than 14 degrees C (T(min)) or more than 28 degrees C (T(max)) were retained by principal component analysis and canonical correlation analysis as the most meaningful epidemic and environmental variables, respectively. AUDPC as the strongest dependent variable and combinations of the environmental variables as independent variables were used in multiple regression analyses. Tissue age rating at the time of infection was a good predictor for disease resulting from spray inoculation on fruits and leaves and also on fruits following a wound inoculation. Temperature, as expressed by T(min) or T(max), was also a significant factor in determining disease development described by AUDPC. Mature green stems were highly susceptible after wounding, similarly to leaves, but buds and leaf scars expressed the lowest susceptibility. These variations in disease expression according to the tissues will have different impacts on ACC epidemiology.

Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution

OpenAIRE

Filée, Jonathan

2015-01-01

Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales). Origin and evolution of these Giant Viruses (GVs) remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for five groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no tr...

”How do the patients and their close relatives experience The Coordinated Investigation Model of Dementia in the North Denmark Region?”

DEFF Research Database (Denmark)

Hulgaard, Hanne; Ottesen, Aase Marie

How do the patients and their close relatives experience The Coordinated Investigation Model of Dementia in the North Denmark Region? The aim of the project was to investigate how the patients and their close relatives experienced the investigation and the subsequent social medicine intervention,...... with lowest effective cost. A formal agreement regarding follow-up should be implemented. The relatives should be more involved during both investigation period and in the socio-medical follow-up....

Signals of speciation: Volatile organic compounds resolve closely related sagebrush taxa, suggesting their importance in evolution

Science.gov (United States)

Deidre M. Jaeger; Justin B. Runyon; Bryce A. Richardson

2016-01-01

Volatile organic compounds (VOCs) play important roles in the environmental adaptation and fitness of plants. Comparison of the qualitative and quantitative differences in VOCs among closely related taxa and assessing the effects of environment on their emissions are important steps to deducing VOC function and evolutionary importance.

Phylogenetic reconstruction and DNA barcoding for closely related pine moth species (Dendrolimus) in China with multiple gene markers.

Science.gov (United States)

Dai, Qing-Yan; Gao, Qiang; Wu, Chun-Sheng; Chesters, Douglas; Zhu, Chao-Dong; Zhang, Ai-Bing

2012-01-01

Unlike distinct species, closely related species offer a great challenge for phylogeny reconstruction and species identification with DNA barcoding due to their often overlapping genetic variation. We tested a sibling species group of pine moth pests in China with a standard cytochrome c oxidase subunit I (COI) gene and two alternative internal transcribed spacer (ITS) genes (ITS1 and ITS2). Five different phylogenetic/DNA barcoding analysis methods (Maximum likelihood (ML)/Neighbor-joining (NJ), "best close match" (BCM), Minimum distance (MD), and BP-based method (BP)), representing commonly used methodology (tree-based and non-tree based) in the field, were applied to both single-gene and multiple-gene analyses. Our results demonstrated clear reciprocal species monophyly for three relatively distant related species, Dendrolimus superans, D. houi, D. kikuchii, as recovered by both single and multiple genes while the phylogenetic relationship of three closely related species, D. punctatus, D. tabulaeformis, D. spectabilis, could not be resolved with the traditional tree-building methods. Additionally, we find the standard COI barcode outperforms two nuclear ITS genes, whatever the methods used. On average, the COI barcode achieved a success rate of 94.10-97.40%, while ITS1 and ITS2 obtained a success rate of 64.70-81.60%, indicating ITS genes are less suitable for species identification in this case. We propose the use of an overall success rate of species identification that takes both sequencing success and assignation success into account, since species identification success rates with multiple-gene barcoding system were generally overestimated, especially by tree-based methods, where only successfully sequenced DNA sequences were used to construct a phylogenetic tree. Non-tree based methods, such as MD, BCM, and BP approaches, presented advantages over tree-based methods by reporting the overall success rates with statistical significance. In addition, our

Phylogenetic reconstruction and DNA barcoding for closely related pine moth species (Dendrolimus in China with multiple gene markers.

Directory of Open Access Journals (Sweden)

Qing-Yan Dai

Full Text Available Unlike distinct species, closely related species offer a great challenge for phylogeny reconstruction and species identification with DNA barcoding due to their often overlapping genetic variation. We tested a sibling species group of pine moth pests in China with a standard cytochrome c oxidase subunit I (COI gene and two alternative internal transcribed spacer (ITS genes (ITS1 and ITS2. Five different phylogenetic/DNA barcoding analysis methods (Maximum likelihood (ML/Neighbor-joining (NJ, "best close match" (BCM, Minimum distance (MD, and BP-based method (BP, representing commonly used methodology (tree-based and non-tree based in the field, were applied to both single-gene and multiple-gene analyses. Our results demonstrated clear reciprocal species monophyly for three relatively distant related species, Dendrolimus superans, D. houi, D. kikuchii, as recovered by both single and multiple genes while the phylogenetic relationship of three closely related species, D. punctatus, D. tabulaeformis, D. spectabilis, could not be resolved with the traditional tree-building methods. Additionally, we find the standard COI barcode outperforms two nuclear ITS genes, whatever the methods used. On average, the COI barcode achieved a success rate of 94.10-97.40%, while ITS1 and ITS2 obtained a success rate of 64.70-81.60%, indicating ITS genes are less suitable for species identification in this case. We propose the use of an overall success rate of species identification that takes both sequencing success and assignation success into account, since species identification success rates with multiple-gene barcoding system were generally overestimated, especially by tree-based methods, where only successfully sequenced DNA sequences were used to construct a phylogenetic tree. Non-tree based methods, such as MD, BCM, and BP approaches, presented advantages over tree-based methods by reporting the overall success rates with statistical significance. In

Functionally relevant diversity of closely related Nitrospira in activated sludge.

Science.gov (United States)

Gruber-Dorninger, Christiane; Pester, Michael; Kitzinger, Katharina; Savio, Domenico F; Loy, Alexander; Rattei, Thomas; Wagner, Michael; Daims, Holger

2015-03-01

Nitrospira are chemolithoautotrophic nitrite-oxidizing bacteria that catalyze the second step of nitrification in most oxic habitats and are important for excess nitrogen removal from sewage in wastewater treatment plants (WWTPs). To date, little is known about their diversity and ecological niche partitioning within complex communities. In this study, the fine-scale community structure and function of Nitrospira was analyzed in two full-scale WWTPs as model ecosystems. In Nitrospira-specific 16S rRNA clone libraries retrieved from each plant, closely related phylogenetic clusters (16S rRNA identities between clusters ranged from 95.8% to 99.6%) within Nitrospira lineages I and II were found. Newly designed probes for fluorescence in situ hybridization (FISH) allowed the specific detection of several of these clusters, whose coexistence in the WWTPs was shown for prolonged periods of several years. In situ ecophysiological analyses based on FISH, relative abundance and spatial arrangement quantification, as well as microautoradiography revealed functional differences of these Nitrospira clusters regarding the preferred nitrite concentration, the utilization of formate as substrate and the spatial coaggregation with ammonia-oxidizing bacteria as symbiotic partners. Amplicon pyrosequencing of the nxrB gene, which encodes subunit beta of nitrite oxidoreductase of Nitrospira, revealed in one of the WWTPs as many as 121 species-level nxrB operational taxonomic units with highly uneven relative abundances in the amplicon library. These results show a previously unrecognized high diversity of Nitrospira in engineered systems, which is at least partially linked to niche differentiation and may have important implications for process stability.

Relational Mobility Explains Between- and Within-Culture Differences in Self-Disclosure to Close Friends

OpenAIRE

Schug, Joanna; Yuki, Masaki; Maddux, William W.

2010-01-01

The current research proposes a novel explanation for previously demonstrated findings that East Asians disclose less personal information to others than do Westerners. We propose that both between- and within-culture differences in self-disclosure toward close friends may be explained by the construct of "relational mobility" - the general degree to which individuals in the society have the opportunities to form new and terminate old relationships. In Study 1, we found that cross-cultural di...

Bud structure, position and fate generate various branching patterns along shoots of closely related Rosaceae species: a review

Directory of Open Access Journals (Sweden)

Evelyne eCostes

2014-12-01

Full Text Available Branching in temperate plants is closely linked to bud fates, either floral or vegetative. Here, we review how the fate of meristematic tissues contained in buds and their position along a shoot imprint specific branching patterns which differ among species. Through examples chosen in closely related species in different genera of the Rosaceae family, a panorama of patterns is apparent. Patterns depend on whether vegetative and floral buds are borne individually or together in mixed buds, develop as the shoot grows or after a rest period, and are located in axillary or terminal positions along the parent shoot. The resulting branching patterns are conserved among varieties in a given species but progressively change with the parent shoot length during plant ontogeny. They can also be modulated by agronomic and environmental conditions. The existence of various organizations in the topology and fate of meristematic tissues and their appendages in closely related species questions the between-species conservation of physiological and molecular mechanisms leading to bud outgrowth vs quiescence and to floral induction vs vegetative development.

Bud structure, position and fate generate various branching patterns along shoots of closely related Rosaceae species: a review.

Science.gov (United States)

Costes, Evelyne; Crespel, Laurent; Denoyes, Béatrice; Morel, Philippe; Demene, Marie-Noëlle; Lauri, Pierre-Eric; Wenden, Bénédicte

2014-01-01

Branching in temperate plants is closely linked to bud fates, either floral or vegetative. Here, we review how the fate of meristematic tissues contained in buds and their position along a shoot imprint specific branching patterns which differ among species. Through examples chosen in closely related species in different genera of the Rosaceae family, a panorama of patterns is apparent. Patterns depend on whether vegetative and floral buds are borne individually or together in mixed buds, develop as the shoot grows or after a rest period, and are located in axillary or terminal positions along the parent shoot. The resulting branching patterns are conserved among varieties in a given species but progressively change with the parent shoot length during plant ontogeny. They can also be modulated by agronomic and environmental conditions. The existence of various organizations in the topology and fate of meristematic tissues and their appendages in closely related species questions the between-species conservation of physiological and molecular mechanisms leading to bud outgrowth vs. quiescence and to floral induction vs. vegetative development.

The experience of being a middle-aged close relative of a person who has suffered a stroke--six months after discharge from a rehabilitation clinic.

Science.gov (United States)

Bäckström, Britt; Sundin, Karin

2010-03-01

Being a close relative brings with it a large number of consequences, with the life situation changing over time. The aim of this study was to illuminate the experiences of being a middle-aged close relative of a person who has suffered a stroke 6 months after being discharged from a medical rehabilitation clinic. Narrative interviews were conducted with nine middle-aged close relatives and analysed using a content analysis with a latent approach. The analysis revealed that being close to someone who had suffered a stroke 6 months after discharge meant; a struggling for control and a renewal of family life in the shadow of suffering and hope. The middle-aged close relatives began to perceive the changed reality. They were struggling to take on something new, become reconciled and find a balance in their family life. Their ability to work, relief from caring concerns and having support and togetherness with others seemed to be essential for the close relatives in their efforts to manage their life situation and maintain their well-being. Having reached the 'halfway point' in their lives and still with half of their life in front of them created worries. They felt dejected about their changed relationships and roles, experience a sense of loss of shared child responsibilities, a negative impact on their marital relationships and sexual satisfaction. They felt trapped in a caring role and they worried about how to endure in the future. The middle-aged close relatives' experiences were of being alone and neglected, in an arduous and complex life situation filled with loss and grief. The findings highlights that health professionals need to see and listen to the close relatives' experiences of transition in order to provide appropriate support adjusted to their varying needs during a time of renewal.

The LOV protein of Xanthomonas citri subsp. citri plays a significant role in the counteraction of plant immune responses during citrus canker.

Directory of Open Access Journals (Sweden)

Ivana Kraiselburd

Full Text Available Pathogens interaction with a host plant starts a set of immune responses that result in complex changes in gene expression and plant physiology. Light is an important modulator of plant defense response and recent studies have evidenced the novel influence of this environmental stimulus in the virulence of several bacterial pathogens. Xanthomonas citri subsp. citri is the bacterium responsible for citrus canker disease, which affects most citrus cultivars. The ability of this bacterium to colonize host plants is influenced by bacterial blue-light sensing through a LOV-domain protein and disease symptoms are considerably altered upon deletion of this protein. In this work we aimed to unravel the role of this photoreceptor during the bacterial counteraction of plant immune responses leading to citrus canker development. We performed a transcriptomic analysis in Citrus sinensis leaves inoculated with the wild type X. citri subsp. citri and with a mutant strain lacking the LOV protein by a cDNA microarray and evaluated the differentially regulated genes corresponding to specific biological processes. A down-regulation of photosynthesis-related genes (together with a corresponding decrease in photosynthesis rates was observed upon bacterial infection, this effect being more pronounced in plants infected with the lov-mutant bacterial strain. Infection with this strain was also accompanied with the up-regulation of several secondary metabolism- and defense response-related genes. Moreover, we found that relevant plant physiological alterations triggered by pathogen attack such as cell wall fortification and tissue disruption were amplified during the lov-mutant strain infection. These results suggest the participation of the LOV-domain protein from X. citri subsp. citri in the bacterial counteraction of host plant defense response, contributing in this way to disease development.

The LOV Protein of Xanthomonas citri subsp. citri Plays a Significant Role in the Counteraction of Plant Immune Responses during Citrus Canker

Science.gov (United States)

Kraiselburd, Ivana; Daurelio, Lucas D.; Tondo, María Laura; Merelo, Paz; Cortadi, Adriana A.; Talón, Manuel; Tadeo, Francisco R.; Orellano, Elena G.

2013-01-01

Pathogens interaction with a host plant starts a set of immune responses that result in complex changes in gene expression and plant physiology. Light is an important modulator of plant defense response and recent studies have evidenced the novel influence of this environmental stimulus in the virulence of several bacterial pathogens. Xanthomonas citri subsp. citri is the bacterium responsible for citrus canker disease, which affects most citrus cultivars. The ability of this bacterium to colonize host plants is influenced by bacterial blue-light sensing through a LOV-domain protein and disease symptoms are considerably altered upon deletion of this protein. In this work we aimed to unravel the role of this photoreceptor during the bacterial counteraction of plant immune responses leading to citrus canker development. We performed a transcriptomic analysis in Citrus sinensis leaves inoculated with the wild type X. citri subsp. citri and with a mutant strain lacking the LOV protein by a cDNA microarray and evaluated the differentially regulated genes corresponding to specific biological processes. A down-regulation of photosynthesis-related genes (together with a corresponding decrease in photosynthesis rates) was observed upon bacterial infection, this effect being more pronounced in plants infected with the lov-mutant bacterial strain. Infection with this strain was also accompanied with the up-regulation of several secondary metabolism- and defense response-related genes. Moreover, we found that relevant plant physiological alterations triggered by pathogen attack such as cell wall fortification and tissue disruption were amplified during the lov-mutant strain infection. These results suggest the participation of the LOV-domain protein from X. citri subsp. citri in the bacterial counteraction of host plant defense response, contributing in this way to disease development. PMID:24260514

Acción inhibitoria de una cepa de Zymomonas mobilis mobilis aislada de caña de azúcar sobre Xanthomonas citri subsp. citri, agente causal de la cancrosis de los cítricos Inhibition of Xanthomonas citri subsp. citri, causal agent of citrus canker, by a strain of Zymomonas mobilis mobilis isolated from sugarcane

Directory of Open Access Journals (Sweden)

María E. Romero

2008-06-01

Full Text Available Zymomonas mobilis mobilis (Zm produce factores antimicrobianos que actúan sobre un amplio espectro de microorganismos patógenos para el hombre, animales y plantas. Un problema importante a resolver en los tratamientos con antimicrobianos, es el desarrollo de resistencia a compuestos empleados actualmente, no siendo las bacterias fitopatógenas una excepción. En el presente trabajo se realizaron ensayos de antagonismo con células (pruebas de estrías cruzadas y sobrenadantes concentrados (Sc (por difusión en agar preparados a partir de cultivos de Zm (aislada de jugo de caña de azúcar producido en Tucumán, frente a la bacteria causal de la cancrosis: Xanthomonas citri subsp. citri. Se evaluaron aislamientos de Xcc sensibles (Xc y resistentes (Xcr a compuestos a base de cobre. Los resultados obtenidos mostraron que la bacteria testigo fue inhibida totalmente por las células de Zm, ejerciendo un efecto bactericida. En los ensayos de difusión en el agar se observó que tanto Xc, como Xcr fueron sensibles al Sc de Zm. Se sabe, por estudios anteriores, que los metabolitos de Zymomonas tienen un efecto deletéreo en la membrana celular de E. coli AB1133, inhibiéndose la respiración de la bacteria inmediatamente de agregado Sc (60 UA. En el presente trabajo se observó el mismo efecto, inhibición total de la respiración en Xc, luego del agregado del Sc (60 UA. Por lo observado, se deduce que el blanco de acción de los metabolitos antimicrobianos de Sc en Xc, sería el mismo que el de E. coli AB1133. Con los resultados obtenidos se considera de interés encarar el estudio de los compuestos de Zm para ser empleados en el control de enfermedades que afectan los cultivos de valor económico de la región, como es el caso de la cancrosis, como así también profundizar acerca de la acción de dichos metabolitos en la membrana de Xanthomonas citri subsp. citri.Zymomonas mobilis mobilis (Zm produces antimicrobial factors, which have an effect on

Comparative genomics of four closely related Clostridium perfringens bacteriophages reveals variable evolution among core genes with therapeutic potential

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Siragusa Gregory R

2011-06-01

Full Text Available Abstract Background Because biotechnological uses of bacteriophage gene products as alternatives to conventional antibiotics will require a thorough understanding of their genomic context, we sequenced and analyzed the genomes of four closely related phages isolated from Clostridium perfringens, an important agricultural and human pathogen. Results Phage whole-genome tetra-nucleotide signatures and proteomic tree topologies correlated closely with host phylogeny. Comparisons of our phage genomes to 26 others revealed three shared COGs; of particular interest within this core genome was an endolysin (PF01520, an N-acetylmuramoyl-L-alanine amidase and a holin (PF04531. Comparative analyses of the evolutionary history and genomic context of these common phage proteins revealed two important results: 1 strongly significant host-specific sequence variation within the endolysin, and 2 a protein domain architecture apparently unique to our phage genomes in which the endolysin is located upstream of its associated holin. Endolysin sequences from our phages were one of two very distinct genotypes distinguished by variability within the putative enzymatically-active domain. The shared or core genome was comprised of genes with multiple sequence types belonging to five pfam families, and genes belonging to 12 pfam families, including the holin genes, which were nearly identical. Conclusions Significant genomic diversity exists even among closely-related bacteriophages. Holins and endolysins represent conserved functions across divergent phage genomes and, as we demonstrate here, endolysins can have significant variability and host-specificity even among closely-related genomes. Endolysins in our phage genomes may be subject to different selective pressures than the rest of the genome. These findings may have important implications for potential biotechnological applications of phage gene products.

Genetically modified yeast of the species Issatchenkia orientalis and closely relates species, and fermentation processes using same

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Suominen, Pirkko [Maple Grove, MN; Aristidou, Aristos [Highland Ranch, CO; Pentilla, Merja [Helsinki, FI; Ilmen, Marja [Helsinki, FI; Ruohonen, Laura [Helsinki, FI; Koivuranta, Kari [Vantaa, FI; Roberg-Perez, Kevin [Minneapolis, MN

2012-01-17

Cells of the species Issatchenkia orientalis and closely related yeast species are transformed with a vector to introduce an exogenous lactate dehydrogenase gene. The cells produce lactic acid efficiently and are resistant at low pH, high lactate titer conditions.

Amplification of DNA of Xanthomonas axonopodis pv. citri from historic citrus canker herbarium specimens.

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Li, Wenbin; Brlansky, Ronald H; Hartung, John S

2006-05-01

Herbaria are important resources for the study of the origins and dispersal of plant pathogens, particularly bacterial plant pathogens that incite local lesions in which large numbers of pathogen genomes are concentrated. Xanthomonas axonopodis pv. citri (Xac), the causal agent of citrus bacterial canker disease, is a notable example of such a pathogen. The appearance of novel strains of the pathogen in Florida and elsewhere make it increasingly important to understand the relationships among strains of this pathogen. USDA-ARS at Beltsville, Maryland maintains approximately 700 herbarium specimens with citrus canker disease lesions up to 90 years old, originally collected from all over the world, and so is an important resource for phytogeographic studies of this bacterium. Unfortunately, DNA in herbarium specimens is degraded and may contain high levels of inhibitors of PCR. In this study, we compared a total of 23 DNA isolation techniques in combination with 31 novel primer pairs in order to develop an efficient protocol for the analysis of Xac DNA in herbarium specimens. We identified the most reliable extraction method, identified in terms of successful amplification by our panel of 31 primer pairs. We also identified the most robust primer pairs, identified as successful in the largest number of extracts prepared by different methods. We amplified Xac genomic sequences up to 542 bp long from herbarium samples up to 89 years old. Primers varied in effectiveness, with some primer pairs amplifying Xac DNA from a 1/10,000 dilution of extract from a single lesion from a citrus canker herbarium specimen. Our methodology will be useful to identify pathogens and perform molecular analyses of bacterial and possibly fungal genomes from herbarium specimens.

Genotipos de frijol (Phaseolus Vulgaris l. resistentes a Xanthomonas campestris pv. phaseoli de Mexico

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Rosa Navarrete

2000-01-01

Full Text Available Genotipos de frijol (Phaseolus vulgaris L. resistentes a Xanthomonas campestris pv. phaseoli de México. Durante 1995 se evaluó la reacción de genotipos de frijol de diversos origenes a Xcp, bajo condiciones de invernadero en el Campo Experimental del Valle de México, del INIFAP. Se realizaron tres experimentos con a120, b44 y csiete genotipos de frijol. Las plantas se inocularon por corte con navajas en la etapa V3, a y b con una mezcla de nueve cepas de Xcp y el c, con cada una de siete cepas con diferente grado de patogenicidad. La severidad se evaluó 20 días después de la inoculación, por comparación con una escala visual de nueve grados. Los datos se analizaron bajo un diseño completamente al azar. En a, los genotipos que mostraron reacción de resistencia a Xcp fueron: A 36, A 475, G 5686, G 11867, Harowood, SEA 14, XAN 266, MCD 4012 y REN 27. En b los genotipos resistentes fueron: Sequía Durango, Taylor y XAN 30. En los experimentos anteriores la severidad de la enfermedad mostró una distribución normal, con el máximo número de genotipos en el grado de severidad cinco en a y seis en b. Los resultados obtenidos indican que el uso de mezclas de cepas de bacterias con diferente patogenicidad es eficiente para identificar genotipos de frijol resistentes a Xcp. Los genotipos resistentes identificados en el último experimento, mostraron respuesta diferencial e interacciones genotipo por cepa. REN 27 y SEA 14 mostraron resistencia a las cepas utilizadas

Studies on the physiological changes in the rice plants infected with Xanthomonas campestris pv. of oryzae, (4)

International Nuclear Information System (INIS)

Watanabe, Minoru; Samejima, Shin-ichi; Hayashi, Nobuo; Hosokawa, Daijiro

1980-01-01

The translocation and accumulation of 14 C-photosynthetic assimilates in rice plants infected with Xanthomonas campestris pv. oryzae were investigated. Approximately the same quantities of assimilates were detected in healthy and infected leaves 1 day after photosynthesis, but 1.7 times as much as healthy leaves assimilates were still remained in infected leaves 7 days after photosynthesis. Much more 14 C-photosynthetic assimilates were generally detected in leaf blade than in leaf sheath or in root within 1 day after photosynthesis, but detected in leaf sheath than in leaf blade later than 2 days after photosynthesis. The rates of translocation of 14 C-assimilates from leaf blade to leaf sheath were lower in inoculated rice plants than in healthy ones. In both healthy and inoculated leaves of susceptible and resistant cultivars, there was a tendency that 14 C-sugar contents decreased, but 14 C-organic acid and -amino acid contents increased gradually after photosynthesis. Incorporation of 14 C-photosynthetic assimilates into invading bacterial cells which were separated from leaf tissues by the methods of leakage and Millipore filtration was not detected immediately after photosynthesis, but became apparent 5 days after photosynthesis. The leakage of 14 C-photosynthetic assimilates from leaf tissues into bathing solution was about 4 times higher in infected leaves than in healthy ones 5 days after photosynthesis, suggesting that the permeability in infected leaf tissues would increase. (author)

Crystallization and preliminary crystallographic studies of LipA, a secretory lipase/esterase from Xanthomonas oryzae pv. oryzae

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Aparna, Gudlur; Chatterjee, Avradip; Jha, Gopaljee; Sonti, Ramesh V.; Sankaranarayanan, Rajan, E-mail: sankar@ccmb.res.in [Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad 500 007 (India)

2007-08-01

The crystallization and preliminary crystallographic studies of LipA, a lipase/esterase secreted by X. oryzae pv. oryzae during its infection of rice plants, are reported. Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight, a serious disease of rice. Several enzymes that are secreted through the type II secretion system of this bacterium play an important role in the plant–microbe interaction, being important for virulence and also being able to induce potent host defence responses. One of these enzymes is a secretory lipase/esterase, LipA, which shows a very weak homology to other bacterial lipases and gives a positive tributyrin plate assay. In this study, LipA was purified from the culture supernatant of an overexpressing clone of X. oryzae pv. oryzae and two types of crystals belonging to space group C2 but with two different unit-cell parameters were obtained using the hanging-drop vapour-diffusion method. Type I crystals diffract to a maximum resolution of 1.89 Å and have unit-cell parameters a = 93.1, b = 62.3, c = 66.1 Å, β = 90.8°. Type II crystals have unit-cell parameters a = 103.6, b = 54.6, c = 66.3 Å, β = 92.6° and diffract to 1.86 Å. Solvent-content analysis shows one monomer in the asymmetric unit in both the crystal forms.

Morphological and biochemical characterization of xanthomonas campestris (pammel) dawson pv. Sesame and it's management by bacterial antagonists

International Nuclear Information System (INIS)

Naqvi, S.F.; Haq, M.I.U.; Tahir, M.I.; Khan, M.A.; Ali, Z.

2013-01-01

Isolates of Xanthomonas campestris (Pammel) Dawson pv. sesami (Xcs) were collected from various locations in Pakistan and were characterized using several biochemical tests including; (KOH) string test, gram staining, H/sub 2/S production, catalase activity, oxidation/fermentation of glucose, oxidase activity and nitrate reduction. The isolates were positive in tests for KOH string assay, H/sub 2/S, catalase and showed negative reactions in gram staining, oxidase test and nitrate reduction while oxidative utilization of glucose was observed. To develop biological control for the pathogen we isolated numerous bacteria from the rhizosphere of sesame plants and screened them for antagonism against the pathogen using the zone inhibition method. Out of 87 isolates, 9 isolates were inhibitory to the pathogen in vitro. Pseudomonas fluorescens ID-3 exhibited the highest zone of inhibition i.e. 7.97mm. All antagonistic isolates were tested for disease control under greenhouse conditions. Four sesame lines that were found to be moderately resistant in previous studies (i.e. 95001, 96007, 96019, and 20003) were selected for evaluating biocontrol efficacy. The isolates were found to control the disease and reduced severity to 3% compared to untreated plants. The isolate P. fluorescens ID-3 was considered to provide the best disease control with each cultivar. Average biocontrol efficiency (BE) of ID-3 was 78.25% while the best BE was obtained in line 96019, i.e. 81%. (author)

Xanthomonas citri ssp. citri requires the outer membrane porin OprB for maximal virulence and biofilm formation.

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Ficarra, Florencia A; Grandellis, Carolina; Galván, Estela M; Ielpi, Luis; Feil, Regina; Lunn, John E; Gottig, Natalia; Ottado, Jorgelina

2017-06-01

Xanthomonas citri ssp. citri (Xcc) causes canker disease in citrus, and biofilm formation is critical for the disease cycle. OprB (Outer membrane protein B) has been shown previously to be more abundant in Xcc biofilms compared with the planktonic state. In this work, we showed that the loss of OprB in an oprB mutant abolishes bacterial biofilm formation and adherence to the host, and also compromises virulence and efficient epiphytic survival of the bacteria. Moreover, the oprB mutant is impaired in bacterial stress resistance. OprB belongs to a family of carbohydrate transport proteins, and the uptake of glucose is decreased in the mutant strain, indicating that OprB transports glucose. Loss of OprB leads to increased production of xanthan exopolysaccharide, and the carbohydrate intermediates of xanthan biosynthesis are also elevated in the mutant. The xanthan produced by the mutant has a higher viscosity and, unlike wild-type xanthan, completely lacks pyruvylation. Overall, these results suggest that Xcc reprogrammes its carbon metabolism when it senses a shortage of glucose input. The participation of OprB in the process of biofilm formation and virulence, as well as in metabolic changes to redirect the carbon flux, is discussed. Our results demonstrate the importance of environmental nutrient supply and glucose uptake via OprB for Xcc virulence. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Aconitase B is required for optimal growth of Xanthomonas campestris pv. vesicatoria in pepper plants.

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Janine Kirchberg

Full Text Available The aerobic plant pathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv colonizes the intercellular spaces of pepper and tomato. One enzyme that might contribute to the successful proliferation of Xcv in the host is the iron-sulfur protein aconitase, which catalyzes the conversion of citrate to isocitrate in the tricarboxylic acid (TCA cycle and might also sense reactive oxygen species (ROS and changes in cellular iron levels. Xcv contains three putative aconitases, two of which, acnA and acnB, are encoded by a single chromosomal locus. The focus of this study is aconitase B (AcnB. acnB is co-transcribed with two genes, XCV1925 and XCV1926, encoding putative nucleic acid-binding proteins. In vitro growth of acnB mutants was like wild type, whereas in planta growth and symptom formation in pepper plants were impaired. While acnA, XCV1925 or XCV1926 mutants showed a wild-type phenotype with respect to bacterial growth and in planta symptom formation, proliferation of the acnB mutant in susceptible pepper plants was significantly impaired. Furthermore, the deletion of acnB led to reduced HR induction in resistant pepper plants and an increased susceptibility to the superoxide-generating compound menadione. As AcnB complemented the growth deficiency of an Escherichia coli aconitase mutant, it is likely to be an active aconitase. We therefore propose that optimal growth and survival of Xcv in pepper plants depends on AcnB, which might be required for the utilization of citrate as carbon source and could also help protect the bacterium against oxidative stress.

Exploiting fine-scale genetic and physiological variation of closely related microbes to reveal unknown enzyme functions.

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Badur, Ahmet H; Plutz, Matthew J; Yalamanchili, Geethika; Jagtap, Sujit Sadashiv; Schweder, Thomas; Unfried, Frank; Markert, Stephanie; Polz, Martin F; Hehemann, Jan-Hendrik; Rao, Christopher V

2017-08-04

Polysaccharide degradation by marine microbes represents one of the largest and most rapid heterotrophic transformations of organic matter in the environment. Microbes employ systems of complementary carbohydrate-specific enzymes to deconstruct algal or plant polysaccharides (glycans) into monosaccharides. Because of the high diversity of glycan substrates, the functions of these enzymes are often difficult to establish. One solution to this problem may lie within naturally occurring microdiversity; varying numbers of enzymes, due to gene loss, duplication, or transfer, among closely related environmental microbes create metabolic differences akin to those generated by knock-out strains engineered in the laboratory used to establish the functions of unknown genes. Inspired by this natural fine-scale microbial diversity, we show here that it can be used to develop hypotheses guiding biochemical experiments for establishing the role of these enzymes in nature. In this work, we investigated alginate degradation among closely related strains of the marine bacterium Vibrio splendidus One strain, V. splendidus 13B01, exhibited high extracellular alginate lyase activity compared with other V. splendidus strains. To identify the enzymes responsible for this high extracellular activity, we compared V. splendidus 13B01 with the previously characterized V. splendidus 12B01, which has low extracellular activity and lacks two alginate lyase genes present in V. splendidus 13B01. Using a combination of genomics, proteomics, biochemical, and functional screening, we identified a polysaccharide lyase family 7 enzyme that is unique to V. splendidus 13B01, secreted, and responsible for the rapid digestion of extracellular alginate. These results demonstrate the value of querying the enzymatic repertoires of closely related microbes to rapidly pinpoint key proteins with beneficial functions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

USE OF COMPETITIVE DNA HYBRIDIZATION TO IDENTIFY DIFFERENCES IN THE GENOMES OF TWO CLOSELY RELATED FECAL INDICATOR BACTERIA

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Although recent technological advances in DNA sequencing and computational biology now allow scientists to compare entire microbial genomes, comparisons of closely related bacterial species and individual isolates by whole-genome sequencing approaches remains prohibitively expens...

The novel virulence-related gene nlxA in the lipopolysaccharide cluster of Xanthomonas citri ssp. citri is involved in the production of lipopolysaccharide and extracellular polysaccharide, motility, biofilm formation and stress resistance.

Science.gov (United States)

Yan, Qing; Hu, Xiufang; Wang, Nian

2012-10-01

Lipopolysaccharide (LPS) is an important virulence factor of Xanthomonas citri ssp. citri, the causative agent of citrus canker disease. In this research, a novel gene, designated as nlxA (novel LPS cluster gene of X. citri ssp. citri), in the LPS cluster of X. citri ssp. citri 306, was characterized. Our results indicate that nlxA is required for O-polysaccharide biosynthesis by encoding a putative rhamnosyltransferase. This is supported by several lines of evidence: (i) NlxA shares 40.14% identity with WsaF, which acts as a rhamnosyltransferase; (ii) sodium dodecylsulphate-polyacrylamide gel electrophoresis analysis showed that four bands of the O-antigen part of LPS were missing in the LPS production of the nlxA mutant; this is also consistent with a previous report that the O-antigen moiety of LPS of X. citri ssp. citri is composed of a rhamnose homo-oligosaccharide; (iii) mutation of nlxA resulted in a significant reduction in the resistance of X. citri ssp. citri to different stresses, including sodium dodecylsulphate, polymyxin B, H(2)O(2), phenol, CuSO(4) and ZnSO(4). In addition, our results indicate that nlxA plays an important role in extracellular polysaccharide production, biofilm formation, stress resistance, motility on semi-solid plates, virulence and in planta growth in the host plant grapefruit. © 2012 THE AUTHORS. MOLECULAR PLANT PATHOLOGY © 2012 BSPP AND BLACKWELL PUBLISHING LTD.

A Risk Assessment Model for Bacterial Leaf Spot of Pepper (Capsicum annuum), Caused by Xanthomonas euvesicatoria, Based on Concentrations of Macronutrients, Micronutrients, and Micronutrient Ratios.

Science.gov (United States)

Dutta, B; Langston, D B; Luo, X; Carlson, S; Kichler, J; Gitaitis, R

2017-11-01

The phytopathogenic bacterium Xanthomonas euvesicatoria causes bacterial leaf spot (BLS) of pepper and has a worldwide distribution. BLS is difficult to control and an integrated management strategy that incorporates crop rotation, use of clean seed and clean plants, weed control, resistant varieties, applications of bactericides, biocontrol agents, and systemic acquired resistance (SAR) inducers is generally recommended. However, even with that arsenal of weapons, BLS can still be responsible for severe losses under favorable environmental conditions. Thus, additional tools need to be added to an overall integrated management strategy to combat BLS. In this article, we developed several models from 2012 to 2014 that were based on how macronutrients, micronutrients, and micronutrient ratios affect BLS severity. Factors used to select a model for validation included highly significant P values, high adjusted R 2 values, low variance inflation factor values (macronutrient and micronutrient concentrations affect plant disease resistance genes in the SAR pathway.

Bacillus Strains Most Closely Related to Bacillus nealsonii Are Not Effectively Circumscribed within the Taxonomic Species Definition

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K. Kealy Peak

2011-01-01

Full Text Available Bacillus strains with >99.7% 16S rRNA gene sequence similarity were characterized with DNA:DNA hybridization, cellular fatty acid (CFA analysis, and testing of 100 phenotypic traits. When paired with the most closely related type strain, percent DNA:DNA similarities (% S for six Bacillus strains were all far below the recommended 70% threshold value for species circumscription with Bacillus nealsonii. An apparent genomic group of four Bacillus strain pairings with 94%–70% S was contradicted by the failure of the strains to cluster in CFA- and phenotype-based dendrograms as well as by their differentiation with 9–13 species level discriminators such as nitrate reduction, temperature range, and acid production from carbohydrates. The novel Bacillus strains were monophyletic and very closely related based on 16S rRNA gene sequence. Coherent genomic groups were not however supported by similarly organized phenotypic clusters. Therefore, the strains were not effectively circumscribed within the taxonomic species definition.

Floral nectary, nectar production dynamics, and floral reproductive isolation among closely related species of Pedicularis.

Science.gov (United States)

Liu, Ya-Nan; Li, Yan; Yang, Fu-Sheng; Wang, Xiao-Quan

2016-02-01

Floral nectar is thought to be one of the most important rewards that attract pollinators in Pedicularis; however, few studies have examined variation of nectary structure and/or nectar secretion in the genus, particularly among closely related species. Here we investigated nectary morphology, nectar quality, and nectar production dynamics in flowers of Pedicularis section Cyathophora. We found a conical floral nectary at the base of the ovary in species of the rex-thamnophila clade. Stomata were found on the surface of the nectary, and copious starch grains were detected in the nectary tissues. In contrast, a semi-annular nectary was found in flowers of the species of the superba clade. Only a few starch grains were observed in tissues of the semi-annular nectary, and the nectar sugar concentration in these flowers was much lower than that in the flowers of the rex-thamnophila clade. Our results indicate that the floral nectary has experienced considerable morphological, structural, and functional differentiation among closely related species of Pedicularis. This could have affected nectar production, leading to a shift of the pollination mode. Our results also imply that variation of the nectary morphology and nectar production may have played an important role in the speciation of sect. Cyathophora. © 2015 Institute of Botany, Chinese Academy of Sciences.

[Identification and analysis of Corydalis boweri, Meconopsis horridula and their close related species of the same genus by using ITS2 DNA barcode].

Science.gov (United States)

Dou, Rong-kun; Bi, Zhen-fei; Bai, Rui-xue; Ren, Yao-yao; Tan, Rui; Song, Liang-ke; Li, Di-qiang; Mao, Can-quan

2015-04-01

The study is aimed to ensure the quality and safety of medicinal plants by using ITS2 DNA barcode technology to identify Corydalis boweri, Meconopsis horridula and their close related species. The DNA of 13 herb samples including C. boweri and M. horridula from Lhasa of Tibet was extracted, ITS PCR were amplified and sequenced. Both assembled and web downloaded 71 ITS2 sequences were removed of 5. 8S and 28S. Multiple sequence alignment was completed and the intraspecific and interspecific genetic distances were calculated by MEGA 5.0, while the neighbor-joining phylogenetic trees were constructed. We also predicted the ITS2 secondary structure of C. boweri, M. horridula and their close related species. The results showed that ITS2 as DNA barcode was able to identify C. boweri, M. horridula as well as well as their close related species effectively. The established based on ITS2 barcode method provides the regular and safe detection technology for identification of C. boweri, M. horridula and their close related species, adulterants and counterfeits, in order to ensure their quality control, safe medication, reasonable development and utilization.

Open-closed homotopy algebra in mathematical physics

International Nuclear Information System (INIS)

Kajiura, Hiroshige; Stasheff, Jim

2006-01-01

In this paper we discuss various aspects of open-closed homotopy algebras (OCHAs) presented in our previous paper, inspired by Zwiebach's open-closed string field theory, but that first paper concentrated on the mathematical aspects. Here we show how an OCHA is obtained by extracting the tree part of Zwiebach's quantum open-closed string field theory. We clarify the explicit relation of an OCHA with Kontsevich's deformation quantization and with the B-models of homological mirror symmetry. An explicit form of the minimal model for an OCHA is given as well as its relation to the perturbative expansion of open-closed string field theory. We show that our open-closed homotopy algebra gives us a general scheme for deformation of open string structures (A ∞ algebras) by closed strings (L ∞ algebras)

The Role of Documentation Quality in Anesthesia-Related Closed Claims: A Descriptive Qualitative Study.

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Wilbanks, Bryan A; Geisz-Everson, Marjorie; Boust, Rebecca R

2016-09-01

Clinical documentation is a critical tool in supporting care provided to patients. Sound documentation provides a picture of clinical events that can be used to improve patient care. However, many other uses for clinical documentation are equally important. Such documentation informs clinical decision support tools, creates a legal record of patient care, assists in financial reimbursement of services, and serves as a repository for secondary data analysis. Conversely, poor documentation can impair patient safety and increase malpractice risk exposure by reflecting poor or inaccurate information that ultimately may guide patient care decisions.Through an examination of anesthesia-related closed claims, a descriptive qualitative study emerged, which explored the antecedents and consequences of documentation quality in the claims reviewed. A secondary data analysis utilized a database generated by the American Association of Nurse Anesthetists Foundation closed claim review team. Four major themes emerged from the analysis. Themes 1, 2, and 4 primarily describe how poor documentation quality can have negative consequences for clinicians. The third theme primarily describes how poor documentation quality that can negatively affect patient safety.

The weathervane model, a functional and structural organization of the two-component alkanesulfonate oxidoreductase SsuD from Xanthomonas citri

International Nuclear Information System (INIS)

Pegos, V.R.; Oliveira, P.S.L.; Balan, A.

2012-01-01

Full text: In Xanthomonas citri, the phytopathogen responsible for the canker citrus disease, we identified in the ssuABCDE operon, genes encoding the alkanesulfonate ABC transporter as well as the two enzymes responsible for oxido reduction of the respective substrates. SsuD and SsuE proteins represent a two-component system that can be assigned to the group of FMNH 2 -dependent monooxygenases. How- ever, despite of the biochemical information about SsuD and SsuE orthologs from Escherichia coli, there is no structural information of how the two proteins work together. In this work, we used ultracentrifugation, SAXS data and molecular modeling to construct a structural/functional model, which consists of eight molecules organized in a weathervane shape. Through this model, SsuD ligand-binding site for NADPH 2 and FMN substrates is clearly exposed, in a way that might allow the protein-protein interactions with SsuE. Moreover, based on molecular dynamics simulations of SsuD in apo state, docked with NADPH 2 , FMN or both substrates, we characterized the residues of the pocket, the mechanism of substrate interaction and transfer of electrons from NADPH 2 to FMN. This is the first report that links functional and biochemical data with structural analyses. (author)

Experiments for habitation-related technologies in closed system

International Nuclear Information System (INIS)

Masuda, Tsuyoshi; Tako, Yasuhiro

2006-01-01

Preliminary habitation experiments, including facility implementation tests, investigation of work load and psychological and physiological effect of human subjects, environmental monitoring tests, and integrated implementation tests were performed in Closed Ecology Experiment Facilities (CEEF). Results showed insufficient ability of CO 2 separator, issues of overtime work of subjects and inadequate communication between subjects and supporting staff outside the modules. Countermeasures for these issues were developed. Results show that habitation experiments from fiscal year 2005 on the CEEF were judged to be feasible. (author)

27 CFR 70.485 - Closing agreements.

Science.gov (United States)

2010-04-01

... Relating to Alcohol, Tobacco, Firearms, and Explosives Administrative Remedies § 70.485 Closing agreements... disadvantage through consummation of such an agreement. (b) Scope of closing agreement—(1) In general. A...

On integrable c < 1 open-closed string theory

International Nuclear Information System (INIS)

Johnson, C.V.

1994-01-01

The integrable structure of open-closed string theories in the (p, q) conformal minimal model backgrounds is presented. The relation between the τ-function of the closed string theory and that of the open-closed string theory is uncovered. The resulting description of the open-closed string theory is shown to fit very naturally into the framework of the sl(q, C) KdV hierarchies. In particular, the twisted bosons which underlie and organise the structure of the closed string theory play a similar role here and may be employed to derive loop equations and correlation function recursion relations for the open-closed strings in a simple way. (orig.)

Allelic Tests and Sequence Analysis of Three Genes for Resistance to Xanthomonas perforans Race T3 in Tomato

Institute of Scientific and Technical Information of China (English)

ZHAO Baimei; CAO Haipeng; DUAN Junjie; YANG Wencai

2015-01-01

Three crosses,Hawaii7981×PI128216,Hawaii7981×LA1589,and PI128216×LA1589,were made to develop F2 populations for testing allelism among three genes Xv3,Rx4,and RxLA1589 conferring resistance to bacterial spot caused by Xanthomonas perforans race T3 in tomato. Each population consisted of 535–1 655 individuals. An infiltration method was used to inoculate the leaves of the parental and F2 plants as well as the susceptible control OH88119 for detecting hypersensitive resistance（HR）. The results showed that all the tomato plants except OH88119 had HR to race T3,indicating that Xv3,Rx4,and RxLA1589 were allelic genes. Genomic DNA fragments of the Rx4 alleles from Hawaii7981,PI128216,and LA1589 were amplified using gene-specific primers and sequenced. No sequence variation was observed in the coding region of Rx4 in the three resistant lines. Based on the published map positions of these loci as well as the allelic tests and sequence data obtained in this study,we speculated that Xv3,Rx4,and RxLA1589 were the same gene. The results will provide useful information for understanding the mechanism of resistance to race T3 and developing resistant tomato varieties.

Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines

DEFF Research Database (Denmark)

Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

2012-01-01

It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

Recent speciation in three closely related sympatric specialists: inferences using multi-locus sequence, post-mating isolation and endosymbiont data.

Directory of Open Access Journals (Sweden)

Huai-Jun Xue

Full Text Available Shifting between unrelated host plants is relatively rare for phytophagous insects, and distinct host specificity may play crucial roles in reproductive isolation. However, the isolation status and the relationship between parental divergence and post-mating isolation among closely related sympatric specialists are still poorly understood. Here, multi-locus sequence were used to estimate the relationship among three host plant-specific closely related flea beetles, Altica cirsicola, A. fragariae and A. viridicyanea (abbreviated as AC, AF and AV respectively. The tree topologies were inconsistent using different gene or different combinations of gene fragments. The relationship of AF+(AC+AV was supported, however, by both gene tree and species tree based on concatenated data. Post-mating reproductive data on the results of crossing these three species are best interpreted in the light of a well established phylogeny. Nuclear-induced but not Wolbachia-induced unidirectional cytoplasmic incompatibility, which was detected in AC-AF and AF-AV but not in AC-AV, may also suggest more close genetic affinity between AC and AV. Prevalence of Wolbachia in these three beetles, and the endosymbiont in most individuals of AV and AC sharing a same wsp haplotype may give another evidence of AF+(AC+AV. Our study also suggested that these three flea beetles diverged in a relative short time (0.94 My, which may be the result of shifting between unrelated host plants and distinct host specificity. Incomplete post-mating isolation while almost complete lineage sorting indicated that effective pre-mating isolation among these three species should have evolved.

Specificity of herbivore-induced hormonal signaling and defensive traits in five closely related milkweeds (Asclepias spp.).

Science.gov (United States)

Agrawal, Anurag A; Hastings, Amy P; Patrick, Eamonn T; Knight, Anna C

2014-07-01

Despite the recognition that phytohormonal signaling mediates induced responses to herbivory, we still have little understanding of how such signaling varies among closely related species and may generate herbivore-specific induced responses. We studied closely related milkweeds (Asclepias) to link: 1) plant damage by two specialist chewing herbivores (milkweed leaf beetles Labidomera clivicolis and monarch caterpillars Danaus plexippus); 2) production of the phytohormones jasmonic acid (JA), salicylic acid (SA), and abscisic acid (ABA); 3) induction of defensive cardenolides and latex; and 4) impacts on Danaus caterpillars. We first show that A. syriaca exhibits induced resistance following monarch herbivory (i.e., reduced monarch growth on previously damaged plants), while the defensively dissimilar A. tuberosa does not. We next worked with a broader group of five Asclepias, including these two species, that are highly divergent in defensive traits yet from the same clade. Three of the five species showed herbivore-induced changes in cardenolides, while induced latex was found in four species. Among the phytohormones, JA and ABA showed specific responses (although they generally increased) to insect species and among the plant species. In contrast, SA responses were consistent among plant and herbivore species, showing a decline following herbivore attack. Jasmonic acid showed a positive quantitative relationship only with latex, and this was strongest in plants damaged by D. plexippus. Although phytohormones showed qualitative tradeoffs (i.e., treatments that enhanced JA reduced SA), the few significant individual plant-level correlations among hormones were positive, and these were strongest between JA and ABA in monarch damaged plants. We conclude that: 1) latex exudation is positively associated with endogenous JA levels, even among low-latex species; 2) correlations among milkweed hormones are generally positive, although herbivore damage induces a

Improvement of xanthan gum production in batch culture using ...

African Journals Online (AJOL)

Yomi

2011-12-21

Dec 21, 2011 ... In this study, the effect of acetic acid on the improvement of xanthan biosynthesis by Xanthomonas campestris b82 was investigated. ... shown that citric acid that is used as a chelating agent in medium to prevent the ... pH value close to the acid pKa) in the medium in one pulse, 30 h after incubation (at the ...

Species-specific relationships between water transparency and male coloration within and between two closely related Lake Victoria cichlid species

NARCIS (Netherlands)

Castillo Cajas, Ruth F; Selz, Oliver M; Ripmeester, Erwin A P; Seehausen, Ole; Maan, Martine E

2012-01-01

Environmental variation in signalling conditions affects animal communication traits, with possible consequences for sexual selection and reproductive isolation. Using spectrophotometry, we studied how male coloration within and between populations of two closely related Lake Victoria cichlid

Increased genetic divergence between two closely related fir species in areas of range overlap

Science.gov (United States)

Wang, Jing; Abbott, Richard J; Ingvarsson, Pär K; Liu, Jianquan

2014-01-01

Because of introgressive hybridization, closely related species can be more similar to each other in areas of range overlap (parapatry or sympatry) than in areas where they are geographically isolated from each other (allopatry). Here, we report the reverse situation based on nuclear genetic divergence between two fir species, Abies chensiensis and Abies fargesii, in China, at sites where they are parapatric relative to where they are allopatric. We examined genetic divergence across 126 amplified fragment length polymorphism (AFLP) markers in a set of 172 individuals sampled from both allopatric and parapatric populations of the two species. Our analyses demonstrated that AFLP divergence was much greater between the species when comparisons were made between parapatric populations than between allopatric populations. We suggest that selection in parapatry may have largely contributed to this increased divergence. PMID:24772279

Using SNPs with varying specificity to quantify hybridization between closely related but genetically distinct moth populations in the wild

Science.gov (United States)

Invasive insect species can potentially hybridize with closely related native populations to produce new phenotypes with deleterious economic and environmental consequences. Monitoring such events is often problematic because populations that can interbreed are typically sufficiently similar that it...

Poecilia picta, a Close Relative to the Guppy, Exhibits Red Male Coloration Polymorphism: A System for Phylogenetic Comparisons.

Directory of Open Access Journals (Sweden)

Anna K Lindholm

Full Text Available Studies on the evolution of female preference and male color polymorphism frequently focus on single species since traits and preferences are thought to co-evolve. The guppy, Poecilia reticulata, has long been a premier model for such studies because female preferences and orange coloration are well known to covary, especially in upstream/downstream pairs of populations. However, focused single species studies lack the explanatory power of the comparative method, which requires detailed knowledge of multiple species with known evolutionary relationships. Here we describe a red color polymorphism in Poecilia picta, a close relative to guppies. We show that this polymorphism is restricted to males and is maintained in natural populations of mainland South America. Using tests of female preference we show female P. picta are not more attracted to red males, despite preferences for red/orange in closely related species, such as P. reticulata and P. parae. Male color patterns in these closely related species are different from P. picta in that they occur in discrete patches and are frequently Y chromosome-linked. P. reticulata have an almost infinite number of male patterns, while P. parae males occur in discrete morphs. We show the red male polymorphism in P. picta extends continuously throughout the body and is not a Y-linked trait despite the theoretical prediction that sexually-selected characters should often be linked to the heterogametic sex chromosome. The presence/absence of red male coloration of P. picta described here makes this an ideal system for phylogenetic comparisons that could reveal the evolutionary forces maintaining mate choice and color polymorphisms in this speciose group.

Serological cross-reactivity between Merkel cell polyomavirus and two closely related chimpanzee polyomaviruses.

Directory of Open Access Journals (Sweden)

Jérôme T J Nicol

Full Text Available Phylogenetic analyses based on the major capsid protein sequence indicate that Merkel cell polyomavirus (MCPyV and chimpanzee polyomaviruses (PtvPyV1, PtvPyV2, and similarly Trichodysplasia spinulosa-associated polyomavirus (TSPyV and the orangutan polyomavirus (OraPyV1 are closely related. The existence of cross-reactivity between these polyomaviruses was therefore investigated. The findings indicated serological identity between the two chimpanzee polyomaviruses investigated and a high level of cross-reactivity with Merkel cell polyomavirus. In contrast, cross-reactivity was not observed between TSPyV and OraPyV1. Furthermore, specific antibodies to chimpanzee polyomaviruses were detected in chimpanzee sera by pre-incubation of sera with the different antigens, but not in human sera.

The giant zooxanthellae-bearing ciliate Maristentor dinoferus (Heterotrichea) is closely related to folliculinidae.

Science.gov (United States)

Miao, Wei; Simpson, Alastair G B; Fu, Chengjie; Lobban, Christopher S

2005-01-01

The small subunit rDNA sequence of Maristentor dinoferus (Lobban, Schefter, Simpson, Pochon, Pawlowski, and Foissner, 2002) was determined and compared with sequences from other Heterotrichea and Karyorelictea. Maristentor resembles Stentor in basic morphology and had been provisionally assigned to Stentoridae. However, our phylogenetic analyses show that Maristentor is more closely related to Folliculinidae. Our results support the creation of a separate family for Maristentor, Maristentoridae n. fam., and also confirm the phylogenetic grouping of Folliculindae, Stentoridae, Blepharismidae, and Maristentoridae, which we informally call 'stentorids'. Maristentor, rather than Stentor itself, appears to be most significant in understanding the origins of folliculinids from their aloricate ancestors. Our analyses suggest continued uncertainty in the exact placement of the root of heterotrichs with this phylogenetic marker.

Structure and Origin of Xanthomonas arboricola pv. pruni Populations Causing Bacterial Spot of Stone Fruit Trees in Western Europe.

Science.gov (United States)

Boudon, Sylvain; Manceau, Charles; Nottéghem, Jean-Loup

2005-09-01

ABSTRACT Xanthomonas arboricola pv. pruni, the causal agent of bacterial spot on stone fruit, was found in 1995 in several orchards in southeastern France. We studied population genetics of this emerging pathogen in comparison with populations from the United States, where the disease was first described, and from Italy, where the disease has occurred since 1920. Four housekeeping genes (atpD, dnaK, efp, and glnA) and the intergenic transcribed spacer region were sequenced from a total of 3.9 kb of sequences, and fluorescent amplified fragment length polymorphism (FAFLP) analysis was performed. A collection of 64 X. arboricola pv. pruni strains, including 23 strains from France, was analyzed. The X. arboricola pv. pruni population had a low diversity because no sequence polymorphisms were observed. Population diversity revealed by FAFLP was lower for the West European population than for the American population. The same bacterial genotype was detected from five countries on three continents, a geographic distribution that can be explained by human-aided migration of bacteria. Our data support the hypothesis that the pathogen originated in the United States and subsequently has been disseminated to other stone-fruit-growing regions of the world. In France, emergence of this disease was due to a recent introduction of the most prevalent genotype of the bacterium found worldwide.

The rice XA21 ectodomain fused to the Arabidopsis EFR cytoplasmic domain confers resistance to Xanthomonas oryzae pv. oryzae.

Science.gov (United States)

Thomas, Nicholas C; Oksenberg, Nir; Liu, Furong; Caddell, Daniel; Nalyvayko, Alina; Nguyen, Yen; Schwessinger, Benjamin; Ronald, Pamela C

2018-01-01

Rice ( Oryza sativa ) plants expressing the XA21 cell-surface receptor kinase are resistant to Xanthomonas oryzae pv. oryzae (Xoo) infection. We previously demonstrated that expressing a chimeric protein containing the ELONGATION FACTOR Tu RECEPTOR (EFR) ectodomain and the XA21 endodomain (EFR:XA21) in rice does not confer robust resistance to Xoo . To test if the XA21 ectodomain is required for Xoo resistance, we produced transgenic rice lines expressing a chimeric protein consisting of the XA21 ectodomain and EFR endodomain (XA21:EFR) and inoculated these lines with Xoo . We also tested if the XA21:EFR rice plants respond to a synthetic sulfated 21 amino acid derivative (RaxX21-sY) of the activator of XA21-mediated immunity, RaxX. We found that five independently transformed XA21:EFR rice lines displayed resistance to Xoo as measured by lesion length analysis, and showed that five lines share characteristic markers of the XA21 defense response (generation of reactive oxygen species and defense response gene expression) after treatment with RaxX21-sY. Our results indicate that expression of the XA21:EFR chimeric receptor in rice confers resistance to Xoo . These results suggest that the endodomain of the EFR and XA21 immune receptors are interchangeable and the XA21 ectodomain is the key determinant conferring robust resistance to Xoo .

Isolation and characterisation of a ruminant alphaherpesvirus closely related to bovine herpesvirus 1 in a free-ranging red deer

Directory of Open Access Journals (Sweden)

Belák Sándor

2007-09-01

Full Text Available Abstract Background The genus Varicellovirus of the Herpesviridae subfamily Alphaherpesvirinae includes a cluster of viruses antigenically and genetically related to bovine herpesvirus 1 (BoHV-1: namely bovine herpesvirus 5 (BoHV-5, bubaline herpesvirus 1 (BuHV-1, caprine herpesvirus 1 (CpHV-1, cervid herpesviruses 1 (CvHV-1 and 2 (CvHV-2 and elk herpesvirus 1 (ElkHV-1. Considering the serological relationship between these ruminant alphaherpesviruses, several surveys have studied the occurrence of BoHV-1 related virus infection in wild and domestic ruminant species. In this way, a recent investigation has indicated, in Belgium, a high increase in the serological prevalence of BoHV-1 related virus infection in free-ranging red deer population. In this context, it has been decided to investigate the presence of an alphaherpesvirus spreading in the Belgian free-ranging red deer population. Results The current study reports the first isolation in a free-ranging red deer of a BoHV-1 closely related virus. The isolate was antigenically, genomically and genetically characterised by comparison with several ruminant alphaherpesvirus. Immunofluorescence assays revealed the isolate was antigenically distinct from bovine and caprine alphaherpesviruses. Similarly, BamHI and BstEII restriction analyses demonstrated the genomic difference between the isolate and the other ruminant alphaherpesviruses. Next, the sequencing of selected parts of UL27 and US8 genes showed a high degree of homologies between each BoHV-1 related ruminant alphaherpesvirus and the isolate. Besides the close relationship between all ruminant alphaherpesviruses, the phylogenetic analysis revealed that the isolate clustered with CvHV-1. Conclusion The first isolation of a virus closely related to BoHV-1 in a free-ranging red deer is reported. Data demonstrate that a CvHV-1 strain, named Anlier, circulates in wild red deer in continental Europe. Anlier strain show consistent differences

Crystallization and preliminary X-ray diffraction analysis of XAC1151, a small heat-shock protein from Xanthomonas axonopodis pv. citri belonging to the α-crystallin family

Energy Technology Data Exchange (ETDEWEB)

Hilario, Eduardo; Teixeira, Elaine Cristina; Pedroso, Gisele Audrei; Bertolini, Maria Célia [Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, Araraquara-SP (Brazil); Medrano, Francisco Javier, E-mail: fjmedrano@yahoo.com [Departamento de Cristalografia de Proteínas, Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, Caixa Postal 6192, CEP 13084-971, Campinas-SP (Brazil); Departamento de Bioquímica e Tecnologia Química, Instituto de Química, Universidade Estadual Paulista, Araraquara-SP (Brazil)

2006-05-01

XAC1151, a small heat-shock protein from X. axonopodis pv. citri belonging to the α-crystallin family, was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. X-ray diffraction data were collected to 1.65 Å resolution using a synchrotron-radiation source. The hspA gene (XAC1151) from Xanthomonas axonopodis pv. citri encodes a protein of 158 amino acids that belongs to the small heat-shock protein (sHSP) family of proteins. These proteins function as molecular chaperones by preventing protein aggregation. The protein was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. X-ray diffraction data were collected to 1.65 Å resolution using a synchrotron-radiation source. The crystal belongs to the rhombohedral space group R3, with unit-cell parameters a = b = 128.7, c = 55.3 Å. The crystal structure was solved by molecular-replacement methods. Structure refinement is in progress.

Cell wall-bound invertase limits sucrose export and is involved in symptom development and inhibition of photosynthesis during compatible interaction between tomato and Xanthomonas campestris pv vesicatoria.

Science.gov (United States)

Kocal, Nurcan; Sonnewald, Uwe; Sonnewald, Sophia

2008-11-01

Cell wall-bound invertase (cw-Inv) plays an important role in carbohydrate partitioning and regulation of sink-source interaction. There is increasing evidence that pathogens interfere with sink-source interaction, and induction of cw-Inv activity has frequently been shown in response to pathogen infection. To investigate the role of cw-Inv, transgenic tomato (Solanum lycopersicum) plants silenced for the major leaf cw-Inv isoforms were generated and analyzed during normal growth and during the compatible interaction with Xanthomonas campestris pv vesicatoria. Under normal growth conditions, activities of sucrolytic enzymes as well as photosynthesis and respiration were unaltered in the transgenic plants compared with wild-type plants. However, starch levels of source leaves were strongly reduced, which was most likely caused by an enhanced sucrose exudation rate. Following X. campestris pv vesicatoria infection, cw-Inv-silenced plants showed an increased sucrose to hexose ratio in the apoplast of leaves. Symptom development, inhibition of photosynthesis, and expression of photosynthetic genes were clearly delayed in transgenic plants compared with wild-type plants. In addition, induction of senescence-associated and pathogenesis-related genes observed in infected wild-type plants was abolished in cw-Inv-silenced tomato lines. These changes were not associated with decreased bacterial growth. In conclusion, cw-Inv restricts carbon export from source leaves and regulates the sucrose to hexose ratio in the apoplast. Furthermore, an increased apoplastic hexose to sucrose ratio can be linked to inhibition of photosynthesis and induction of pathogenesis-related gene expression but does not significantly influence bacterial growth. Indirectly, bacteria may benefit from low invertase activity, since the longevity of host cells is raised and basal defense might be dampened.

Non-commercial surrogacy among close relatives in Vietnam: policy and ethical implications.

Science.gov (United States)

Hibino, Yuri

2018-04-19

Altruistic surrogacy among close relatives has been legal in Vietnam since the beginning of 2015. Following the revision of the Marriage and Family Law, there have been dozens of cases of surrogacy, and instances of successful pregnancy and childbirth have also been reported. Although surrogacy was completely prohibited in 2003, numerous local brokers offered commercial surrogacy services. Today, surrogacy is permitted under very limited conditions, and commercial surrogacy is prohibited. However, brokers continue to offer illegal commercial surrogacy services, and some even present its incidence may be increasing. In terms of women's roles, Vietnamese society places the highest value on motherhood, and childless couples are stigmatized. Thus, the demand for surrogates is high in Vietnam, rendering it difficult for family members to meet the needs of all those seeking these services. This article considers the consequences and implications of the new surrogacy policy in Vietnam based on field research.

Cloning, crystallization and preliminary X-ray studies of XC2981 from Xanthomonas campestris, a putative CutA1 protein involved in copper-ion homeostasis

International Nuclear Information System (INIS)

Lin, Chien-Hung; Chin, Ko-Hsin; Gao, Fei Philip; Lyu, Ping-Chiang; Shr, Hui-Lin; Wang, Andrew H.-J.; Chou, Shan-Ho

2006-01-01

A probable copper-ion tolerance protein from the plant pathogen X. campestris has been overexpressed in E. coli, purified and crystallized. Divalent metal ions play key roles in all living organisms, serving as cofactors for many proteins involved in a variety of electron-transfer activities. However, copper ions are highly toxic when an excessive amount is accumulated in a cell. CutA1 is a protein found in all kingdoms of life that is believed to participate in copper-ion tolerance in Escherichia coli, although its specific function remains unknown. Several crystal structures of multimeric CutA1 with different rotation angles and degrees of interaction between trimer interfaces have been reported. Here, the cloning, expression, crystallization and preliminary X-ray analysis of XC2981, a possible CutA1 protein present in the plant pathogen Xanthomonas campestris, are reported. The XC2981 crystals diffracted to a resolution of 2.6 Å. They are cubic and belong to space group I23, with unit-cell parameters a = b = c = 130.73 Å

Identification of Bacterial Plant Pathogens Using Multilocus Polymerase Chain Reaction/Electrospray Ionization-Mass Spectrometry

Science.gov (United States)

2008-01-01

pathogens also have been detected and identified by numerous nucleic acid-based techniques, including Southern blot hybridization and direct nucleotide...Xanthomonas axonopodis pv. vitians FB-1309; ATCC19320 Lettuce ; USA 1 Xanthomonas axonopodis sp. alfalfae XA129; Med. 2 Alfalfa; Sudan 1 Xanthomonas

Evaluation of multiple approaches to identify genome-wide polymorphisms in closely related genotypes of sweet cherry (Prunus avium L.

Directory of Open Access Journals (Sweden)

Seanna Hewitt

Full Text Available Identification of genetic polymorphisms and subsequent development of molecular markers is important for marker assisted breeding of superior cultivars of economically important species. Sweet cherry (Prunus avium L. is an economically important non-climacteric tree fruit crop in the Rosaceae family and has undergone a genetic bottleneck due to breeding, resulting in limited genetic diversity in the germplasm that is utilized for breeding new cultivars. Therefore, it is critical to recognize the best platforms for identifying genome-wide polymorphisms that can help identify, and consequently preserve, the diversity in a genetically constrained species. For the identification of polymorphisms in five closely related genotypes of sweet cherry, a gel-based approach (TRAP, reduced representation sequencing (TRAPseq, a 6k cherry SNParray, and whole genome sequencing (WGS approaches were evaluated in the identification of genome-wide polymorphisms in sweet cherry cultivars. All platforms facilitated detection of polymorphisms among the genotypes with variable efficiency. In assessing multiple SNP detection platforms, this study has demonstrated that a combination of appropriate approaches is necessary for efficient polymorphism identification, especially between closely related cultivars of a species. The information generated in this study provides a valuable resource for future genetic and genomic studies in sweet cherry, and the insights gained from the evaluation of multiple approaches can be utilized for other closely related species with limited genetic diversity in the breeding germplasm. Keywords: Polymorphisms, Prunus avium, Next-generation sequencing, Target region amplification polymorphism (TRAP, Genetic diversity, SNParray, Reduced representation sequencing, Whole genome sequencing (WGS

Closed orbit related problems: Correction, feedback, and analysis

International Nuclear Information System (INIS)

Bozoki, E.S.

1995-01-01

Orbit correction - moving the orbit to a desired orbit, orbit stability - keeping the orbit on the desired orbit using feedback to filter out unwanted noise, and orbit analysis - to learn more about the model of the machine, are strongly interrelated. They are the three facets of the same problem. The better one knows the model of the machine, the better the predictions that can be made on the behavior of the machine (inverse modeling) and the more accurately one can control the machine. On the other hand, one of the tools to learn more about the machine (modeling) is to study and analyze the orbit response to open-quotes kicks.close quotes

Cloning, expression, crystallization and preliminary X-ray analysis of a putative multiple antibiotic resistance repressor protein (MarR) from Xanthomonas campestris

International Nuclear Information System (INIS)

Tu, Zhi-Le; Li, Juo-Ning; Chin, Ko-Hsin; Chou, Chia-Cheng; Lee, Cheng-Chung; Shr, Hui-Lin; Lyu, Ping-Chiang; Gao, Fei Philip; Wang, Andrew H.-J.; Chou, Shan-Ho

2005-01-01

A putative repressor for the multiple antibiotic resistance operon from a plant pathogen X. campestris pv. campestris has been overexpressed in E. coli, purified and crystallized. The crystals diffracted to 2.3 Å with good quality. The multiple antibiotic resistance operon (marRAB) is a member of the multidrug-resistance system. When induced, this operon enhances resistance of bacteria to a variety of medically important antibiotics, causing a serious global health problem. MarR is a marR-encoded protein that represses the transcription of the marRAB operon. Through binding with salicylate and certain antibiotics, however, MarR can derepress and activate the marRAB operon. In this report, the cloning, expression, crystallization and preliminary X-ray analysis of XC1739, a putative MarR repressor protein present in the Xanthomonas campestris pv. campestris, a Gram-negative bacterium causing major worldwide disease of cruciferous crops, are described. The XC1739 crystals diffracted to a resolution of at least 1.8 Å. They are orthorhombic and belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 39.5, b = 54.2 and c = 139.5 Å, respectively. They contain two molecules in the asymmetric unit from calculation of the self-rotation function

Structural and functional analyses of the putrescine binding protein PotF from Xanthomonas citri

International Nuclear Information System (INIS)

Santana, L.D.F.; Balan, A.

2012-01-01

Full text: The focus of our group is to determinate the role of ABC transporters in the physiology and growth of Xanthomonas citri, a phytopathogenic bacteria that infects citrus plants causing significant losses for the economy. One of the ABC transporters identified in the X. citri genome and that was showed to be active during the infection in Citrus sinensis plants was the putrescine transporter. This transporter consists of two internal membrane proteins PotG and PotH that form a pore, a cytoplasmic protein that gives energy for the transport and the periplasmic-binding protein PotF, which is responsible for the affinity and specificity of the system. Its function is associated to the microbial carcinogenesis, biofilm formation, escape from phagolysosomes, bacteriocin production, toxin activity and protection from oxidative and acid stress. In this work, we show for the first time, the expression, purification, functional and structural analyses of the X. citri PotF protein. The PotF was expressed from Escherichia coli cells strain Arctic, as a 40 kDa soluble protein, after induction of IPTG for twenty four hours at thirteen deg C. Using immobilized metal affinity chromatography for purification, the protein was eluted in the fractions with 10-500 mM of imidazole. To test the folding and cability to bind putrescine, spectroscopic analyses were performed using circular dichroism and intrinsic fluorescence. The data showed that PotF suffers conformational changes in presence of ligands and in different pH, suggesting a possible interaction with the tested ligand. Moreover, based on bioinformatics studies and molecular modeling analyses, we showed that X. citri PotF is highly conserved when compared to orthologs present in other bacteria, including the residues that form the ligand-binding site. The production of PotF in a soluble and stable form will allow us to start the crystallization trials in attempt to solve its structure. (author)

Structural and functional analyses of the putrescine binding protein PotF from Xanthomonas citri

Energy Technology Data Exchange (ETDEWEB)

Santana, L.D.F.; Balan, A. [Laboratorio Nacional de Biociencias - LNBIO, Campinas, SP (Brazil)

2012-07-01

Full text: The focus of our group is to determinate the role of ABC transporters in the physiology and growth of Xanthomonas citri, a phytopathogenic bacteria that infects citrus plants causing significant losses for the economy. One of the ABC transporters identified in the X. citri genome and that was showed to be active during the infection in Citrus sinensis plants was the putrescine transporter. This transporter consists of two internal membrane proteins PotG and PotH that form a pore, a cytoplasmic protein that gives energy for the transport and the periplasmic-binding protein PotF, which is responsible for the affinity and specificity of the system. Its function is associated to the microbial carcinogenesis, biofilm formation, escape from phagolysosomes, bacteriocin production, toxin activity and protection from oxidative and acid stress. In this work, we show for the first time, the expression, purification, functional and structural analyses of the X. citri PotF protein. The PotF was expressed from Escherichia coli cells strain Arctic, as a 40 kDa soluble protein, after induction of IPTG for twenty four hours at thirteen deg C. Using immobilized metal affinity chromatography for purification, the protein was eluted in the fractions with 10-500 mM of imidazole. To test the folding and cability to bind putrescine, spectroscopic analyses were performed using circular dichroism and intrinsic fluorescence. The data showed that PotF suffers conformational changes in presence of ligands and in different pH, suggesting a possible interaction with the tested ligand. Moreover, based on bioinformatics studies and molecular modeling analyses, we showed that X. citri PotF is highly conserved when compared to orthologs present in other bacteria, including the residues that form the ligand-binding site. The production of PotF in a soluble and stable form will allow us to start the crystallization trials in attempt to solve its structure. (author)

Close and distant: Contrasting the metabolism of two closely related subspecies of Scots pine under the effects of folivory and summer drought

Energy Technology Data Exchange (ETDEWEB)

Rivas-Ubach, Albert; Sardans, J.; Hodar, Jose A.; Garcia-Porta, Joan; Guenther, Alex B.; Pasa Tolic, Ljiljana; Oravec, Michal; Urban, Otmar; Penuelas, Josep

2017-09-25

The metabolome, the chemical phenotype of an organism, should be shaped by evolution. Metabolomes depend on genetic composition and expression, which can be sources of evolutionary inertia, so most aspects of metabolomes should be similar in closely related sympatric species. We examined the metabolomes of two sympatric subspecies of Pinus sylvestris in Sierra Nevada (southern Iberian Peninsula), one introduced (ssp. iberica) and one autochthonous (ssp. nevadensis), in summer and winter and exposed to folivory by the pine processionary moth. The overall metabolomes differed between the subspecies but both tended to respond more similarly to folivory. The metabolomes of the subspecies were more dissimilar in summer than in winter, and iberica trees had higher concentrations of metabolites directly related to drought stress. Our results suggest that certain plant metabolic responses associated with folivory have been conserved throughout evolutionary history. The larger divergence between subspecies metabolomes in summer is likely due to the warmer and drier conditions that the northern iberica subspecies experience in Sierra Nevada. Our results provide crucial insights into how iberica populations would respond to the predicted conditions of climate change under an increased defoliation, two recent severe issues in the Mediterranean Basin.

CREB expression in the brains of two closely related parasitic wasp species that differ in long-term memory formation

NARCIS (Netherlands)

Van den Berg, M.; Verbaarschot, P.; Hontelez, S.; Vet, L.E.M.; Dicke, M.; Smid, H.M.

2010-01-01

The cAMP/PKA signalling pathway and transcription factor cAMP response element-binding protein (CREB) play key roles in long-term memory (LTM) formation. We used two closely related parasitic wasp species, Cotesia glomerata and Cotesia rubecula, which were previously shown to be different in LTM

Composition of the essential oils from underground parts of Valeriana officinalis L. s.l. and several closely related taxa

NARCIS (Netherlands)

Bos, Rein; Woerdenbag, Herman J.; Hendriks, Henk; Scheffer, Johannes J. C.

1997-01-01

The volatile constituents from roots and rhizomes of Valeriana officinalis L. s.l. and of several closely related Valeriana taxa were investigated by GC and GCMS (EI and NICI) analysis. Seeds were obtained from different botanical gardens in Europe, and the plants investigated were grown in an

Differential regulation of two closely related integrative and conjugative elements from Streptococcus thermophilus

Directory of Open Access Journals (Sweden)

Carraro Nicolas

2011-10-01

Full Text Available Abstract Background Two closely related ICEs, ICESt1 and ICESt3, have been identified in the lactic acid bacterium Streptococcus thermophilus. While their conjugation and recombination modules are almost identical (95% nucleotide identity and their regulation modules related, previous work has demonstrated that transconjugants carrying ICESt3 were generated at rate exceeding by a 1000 factor that of ICESt1. Results The functional regulation of ICESt1 and ICESt3 transcription, excision and replication were investigated under different conditions (exponential growth or stationary phase, DNA damage by exposition to mitomycin C. Analysis revealed an identical transcriptional organization of their recombination and conjugation modules (long unique transcript whereas the transcriptional organization of their regulation modules were found to be different (two operons in ICESt1 but only one in ICESt3 and to depend on the conditions (promoter specific of stationary phase in ICESt3. For both elements, stationary phase and DNA damage lead to the rise of transcript levels of the conjugation-recombination and regulation modules. Whatever the growth culture conditions, excision of ICESt1 was found to be lower than that of ICESt3, which is consistent with weaker transfer frequencies. Furthermore, for both elements, excision increases in stationary phase (8.9-fold for ICESt1 and 1.31-fold for ICESt3 and is strongly enhanced by DNA damage (38-fold for ICESt1 and 18-fold for ICESt3. Although ICEs are generally not described as replicative elements, the copy number of ICESt3 exhibited a sharp increase (9.6-fold after mitomycin C exposure of its harboring strain CNRZ385. This result was not observed when ICESt3 was introduced in a strain deriving ICESt1 host strain CNRZ368, deleted for this element. This finding suggests an impact of the host cell on ICE behavior. Conclusions All together, these results suggest a novel mechanism of regulation shared by ICESt1

Inter- and intra-guild interactions related to aphids in nettle (Urtica dioica L.) strips closed to field crops.

Science.gov (United States)

Alhmedi, A; Haubruge, E; Bodson, B; Francis, F

2006-01-01

A field experiment designed to assess the biodiversity related to nettle strips closed to crops, and more particularly the aphid and related beneficial populations, was established in experimental farm located in Gembloux (Belgium). Margin strips of nettle (Urtica dioica) closed to wheat (Triticum aestivum), green pea (Pisum sativum) and rape (Brassicae napus) fields were investigated. The diversity, abundance of aphids and related predators were analysed according to the plant crop species and the differential pesticide application (treated plot and control). Insects were visually observed every week during all the cultivation season. Two main families of aphidophagous predators were found in all field crops and nettle, the Coccinellidae and Syrphidae. The diversity of the aphidophagous predators was shown to be higher on nettle than in field crops, particularly the Chrysopidae, the Anthocoridae and the Miridae. However, a striking difference of ladybird abundance was observed according to the aphid host plant. In one side, Coccinella septempunctata was much more abundant on Acyrthosiphon pisum infested green pea than on the other host plant species. At the opposite, higher occurrence of Harmonia axyridis was observed on the aphid infested nettle plants than on the crop plants. In particular, none of H. axyridis was found in wheat crop. Also, more than only a significant positive correlation between predator and aphid abundance, specialised relations between particular aphid species and some so-called generalist predators was determined in the fields. Finally, intraguild interactions between the aphidophagous predators was assessed and shown that only a significant negative correlation between Episyrphus balteatus and H. axyridis related to the nettle aphid, Micrlophium carnosum, was observed. The relative distribution of the ladybirds, namely C. septempunctata and H. axyridis according to the host plant, nettle strips and crop plots was discussed in relation to

Inverted duplication including Endothelin 3 closely related to dermal hyperpigmentation in Silkie chickens

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Ming TIAN,Suyun FANG,Yanqiang WANG,Xiaorong GU,Chungang FENG,Rui HAO,Xiaoxiang HU,Ning LI

2014-06-01

Full Text Available The dermal hyperpigmentation phenotype in chickens is controlled by the dominant fibromelanosis allele. One of the ten unique characteristics of Silkie chickens is the fibromelanosis phenotype, which is pigmentation in the dermal layer of the skin and connective tissue. In this study, we found a mutation of fibromelanosis, a genomic rearrangement that included an inverted duplication of endothelin3 (EDN3, is responsible. We show that, as a stimulator of melanoblast proliferation, EDN3 expression was increased in silkie embryos and in both skin and muscle throughout adulthood. EDN3 expression led to an increase in expression of the downstream genes EDNRB2 and TYRP2, and was closely relate with the hyperpigmentation phenotype. We examined eight different Chinese chicken breeds showing hyperpigmentation and conclude that this structural genetic variant exists in all fibromelanosis chicken breeds.

Diffusible Signal Factor (DSF) Synthase RpfF of Xylella fastidiosa Is a Multifunction Protein Also Required for Response to DSF

OpenAIRE

Ionescu, Michael; Baccari, Clelia; Da Silva, Aline Maria; Garcia, Angelica; Yokota, Kenji; Lindow, Steven E.

2013-01-01

Xylella fastidiosa, like related Xanthomonas species, employs an Rpf cell-cell communication system consisting of a diffusible signal factor (DSF) synthase, RpfF, and a DSF sensor, RpfC, to coordinate expression of virulence genes. While phenotypes of a ΔrpfF strain in Xanthomonas campestris could be complemented by its own DSF, the DSF produced by X. fastidiosa (XfDSF) did not restore expression of the XfDSF-dependent genes hxfA and hxfB to a ΔrpfF strain of X. fastidiosa, suggesting that Rp...

Endophytic Streptomyces spp. as Biocontrol Agents of Rice Bacterial Leaf Blight Pathogen (Xanthomonas oryzae pv. oryzae

Directory of Open Access Journals (Sweden)

RATIH DEWI HASTUTI

2012-12-01

Full Text Available Xanthomonas oryzae pv. oryzae (Xoo, a causal agent of bacterial leaf blight (BLB, is one of the most important pathogens of rice. The effectiveness of ten Streptomyces spp. isolates in suppressing Xoo disease was assessed in planta and in vitro. In planta experiments were carried out in a greenhouse and arranged in a randomized completely block design (RCBD with three replications. Twenty treatments were tested which included plants inoculated with both Streptomyces spp. and Xoo, and plants inoculated with only Streptomyces spp. Plants inoculated with Xoo and sprayed with a chemical bactericide, and plants inoculated with only Xoo served as positive controls, whereas plants not inoculated with either Streptomyces spp. or Xoo were used as negative controls. The results showed that the effect of endophytic Streptomyces spp. on BLB disease expressed as area under disease progress curve (AUDPC was not significantly different to that on control plants (P > 0.05. However, plants inoculated with endophytic Streptomyces spp. were significantly taller and produced higher tiller number than control plants (P < 0.05. Streptomyces spp. isolate AB131-1 gave the highest plant height. In vitro studies on biocontrol mechanisms of selected Streptomyces spp. isolates showed that isolate LBR02 gave the highest inhibition activity on Xoo growth, followed by AB131-1 and AB131-2. Two isolates (AB131-1 and LBR02 were able to produce chitinase, phosphatase, and siderophore which included biocontrol characteristics. Morphological and colonization studies under SEM and light microscopy confirmed that the three isolates were endophytic Streptomyces spp. from different species. These studies found that the paddy plant which was inoculated with endophytic Streptomyces spp. AB131-1 and infected by Xoo could increase the height of plant and number of tillers.

Transcriptome reprogramming of resistant and susceptible peach genotypes during Xanthomonas arboricola pv. pruni early leaf infection.

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Fabio Gervasi

Full Text Available Bacterial spot caused by Xanthomonas arboricola pv. pruni (Xap is a major threat to Prunus species worldwide. The molecular mechanisms of peach resistance to Xap during early leaf infection were investigated by RNA-Seq analysis of two Prunus persica cultivars, 'Redkist' (resistant, and 'JH Hale' (susceptible at 30 minutes, 1 and 3 hours-post-infection (hpi. Both cultivars exhibited extensive modulation of gene expression at 30 mpi, which reduced significantly at 1 hpi, increasing again at 3 hpi. Overall, 714 differentially expressed genes (DEGs were detected in 'Redkist' (12% at 30 mpi and 1 hpi and 88% at 3 hpi. In 'JH Hale', 821 DEGs were identified (47% at 30 mpi and 1 hpi and 53% at 3 hpi. Highly up-regulated genes (fold change > 100 at 3 hpi exhibited higher fold change values in 'Redkist' than in 'JH Hale'. RNA-Seq bioinformatics analyses were validated by RT-qPCR. In both cultivars, DEGs included genes with putative roles in perception, signal transduction, secondary metabolism, and transcription regulation, and there were defense responses in both cultivars, with enrichment for the gene ontology terms, 'immune system process', 'defense response', and 'cell death'. There were particular differences between the cultivars in the intensity and kinetics of modulation of expression of genes with putative roles in transcriptional activity, secondary metabolism, photosynthesis, and receptor and signaling processes. Analysis of differential exon usage (DEU revealed that both cultivars initiated remodeling their transcriptomes at 30 mpi; however, 'Redkist' exhibited alternative exon usage for a greater number of genes at every time point compared with 'JH Hale'. Candidate resistance genes (WRKY-like, CRK-like, Copper amine oxidase-like, and TIR-NBS-LRR-like are of interest for further functional characterization with the aim of elucidating their role in Prunus spp. resistance to Xap.

49 CFR 236.786 - Principle, closed circuit.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Principle, closed circuit. 236.786 Section 236.786 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Principle, closed circuit. The principle of circuit design where a normally energized electric circuit which...

Multilocus Sequence Typing Reveals Relevant Genetic Variation and Different Evolutionary Dynamics among Strains of Xanthomonas arboricola pv. juglandis

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Marco Scortichini

2010-11-01

Full Text Available Forty-five Xanthomonas arboricola pv. juglandis (Xaj strains originating from Juglans regia cultivation in different countries were molecularly typed by means of MultiLocus Sequence Typing (MLST, using acnB, gapA, gyrB and rpoD gene fragments. A total of 2.5 kilobases was used to infer the phylogenetic relationship among the strains and possible recombination events. Haplotype diversity, linkage disequilibrium analysis, selection tests, gene flow estimates and codon adaptation index were also assessed. The dendrograms built by maximum likelihood with concatenated nucleotide and amino acid sequences revealed two major and two minor phylotypes. The same haplotype was found in strains originating from different continents, and different haplotypes were found in strains isolated in the same year from the same location. A recombination breakpoint was detected within the rpoD gene fragment. At the pathovar level, the Xaj populations studied here are clonal and under neutral selection. However, four Xaj strains isolated from walnut fruits with apical necrosis are under diversifying selection, suggesting a possible new adaptation. Gene flow estimates do not support the hypothesis of geographic isolation of the strains, even though the genetic diversity between the strains increases as the geographic distance between them increases. A triplet deletion, causing the absence of valine, was found in the rpoD fragment of all 45 Xaj strains when compared with X. axonopodis pv. citri strain 306. The codon adaptation index was high in all four genes studied, indicating a relevant metabolic activity.

The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris.

Science.gov (United States)

Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

2015-04-01

Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

La proteína PthB de Xanthomonas axonopodis pv. manihotis es autoactiva en ensayos de doble hibrido

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Juliana Gil

2011-01-01

Full Text Available La bacteriosis vascular de yuca producida por la bacteria Xanthomonas axonopodis pv. manihotis (Xam es uno de los factores limitantes para la producción de yuca. Dentro de los primeros factores de patogenicidad identificados en esta bacteria se encuentra el gen pthB. La proteína PthB pertenece a la familia de efectores PthA/AvrBs3, que se caracterizan por presentar dominios NLS (Nuclear Localization Signal y un dominio AAD (Acidic Activation Domain, lo cual sugiere que estas proteínas actúan como factores de transcripción. La identificación de las proteínas de yuca que interactúan con PthB permitiría dar luces sobre la función de esta proteína en la patogenicidad de esta bacteria. En este trabajo se clonó pthB en una fusión traduccional con el BD (Binding Domain del factor de transcripción GAL4. Después de transformar este constructo en una cepa de levadura, se observó autoactivación de los genes reporteros, incluso a concentraciones altas de 3-AT. La eliminación del primer, segundo o de los dos NLS y del AAD no eliminaron la capacidad de autoactivación de los genes reporteros mediada por PthB. Estos resultados indican la imposibilidad de su utilización en un tamizaje de una librería de ADNc de yuca para identificar las proteínas que interactúan con PthB.

Expression, crystallization and preliminary X-ray crystallographic analysis of Xoo0352, d-alanine-d-alanine ligase A, from Xanthomonas oryzae pv. oryzae

International Nuclear Information System (INIS)

Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Kim, Hyesoon; Ahn, Yeh-Jin; Kim, Jeong-Gu; Lee, Byoung-Moo; Kang, Lin-Woo

2008-01-01

Xoo0352, which encodes d-alanine-d-alanine ligase A (DdlA), from X. oryzae pv. oryzae was cloned, purified and crystallized. Preliminary X-ray crystallographic analysis of DdlA crystals was performed. Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), which is one of the most devastating diseases of rice in most rice-growing countries. d-Alanine-d-alanine ligase A (DdlA), coded by the Xoo0352 gene, was expressed, purified and crystallized. DdlA is an enzyme that is involved in d-alanine metabolism and the biosynthesis of an essential bacterial peptidoglycan precursor, in which it catalyzes the formation of d-alanyl-d-alanine from two d-alanines, and is thus an attractive antibacterial drug target against Xoo. The DdlA crystals diffracted to 2.3 Å resolution and belonged to the primitive tetragonal space group P4 3 2 1 2, with unit-cell parameters a = b = 83.0, c = 97.6 Å. There is one molecule in the asymmetric unit, with a corresponding V M of 1.88 Å 3 Da −1 and a solvent content of 34.6%. The initial structure was determined by molecular replacement using d-alanine-d-alanine ligase from Staphylococcus aureus as a template model

22 CFR 1500.9 - Transcripts, recording of closed meetings.

Science.gov (United States)

2010-04-01

..., closed to the public. (b) The Foundation, after review by the General Counsel, shall make promptly... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Transcripts, recording of closed meetings. 1500.9 Section 1500.9 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION SUNSHINE REGULATIONS § 1500.9...

Close monitoring as a contextual stimulator : How need for structure affects the relation between close monitoring and work outcomes

NARCIS (Netherlands)

Rietzschel, Eric F.; Slijkhuis, Marjette; Van Yperen, Nico W.

2014-01-01

In this article, we argue and demonstrate that employees' Personal Need for Structure (PNS) moderates the negative effects of close monitoring on job satisfaction, intrinsic work motivation, and innovative job performance (as rated by their supervisors). In a field study (N=295), we found that

A comparative approach to closed-loop computation.

Science.gov (United States)

Roth, E; Sponberg, S; Cowan, N J

2014-04-01

Neural computation is inescapably closed-loop: the nervous system processes sensory signals to shape motor output, and motor output consequently shapes sensory input. Technological advances have enabled neuroscientists to close, open, and alter feedback loops in a wide range of experimental preparations. The experimental capability of manipulating the topology-that is, how information can flow between subsystems-provides new opportunities to understand the mechanisms and computations underlying behavior. These experiments encompass a spectrum of approaches from fully open-loop, restrained preparations to the fully closed-loop character of free behavior. Control theory and system identification provide a clear computational framework for relating these experimental approaches. We describe recent progress and new directions for translating experiments at one level in this spectrum to predictions at another level. Operating across this spectrum can reveal new understanding of how low-level neural mechanisms relate to high-level function during closed-loop behavior. Copyright © 2013 Elsevier Ltd. All rights reserved.

Closed 1-forms in topology and geometric group theory

Energy Technology Data Exchange (ETDEWEB)

Farber, Michael; Schuetz, Dirk [University of Durham, Durham (United Kingdom); Geoghegan, Ross [State University of New York, New York (United States)

2010-01-01

In this article we describe relations of the topology of closed 1-forms to the group-theoretic invariants of Bieri-Neumann-Strebel-Renz. Starting with a survey, we extend these Sigma invariants to finite CW-complexes and show that many properties of the group-theoretic version have analogous statements. In particular, we show the relation between Sigma invariants and finiteness properties of certain infinite covering spaces. We also discuss applications of these invariants to the Lusternik-Schnirelmann category of a closed 1-form and to the existence of a non-singular closed 1-form in a given cohomology class on a high-dimensional closed manifold. Bibliography: 32 titles.

Bioinformatics analysis to assess potential risks of allergenicity and toxicity of HRAP and PFLP proteins in genetically modified bananas resistant to Xanthomonas wilt disease.

Science.gov (United States)

Jin, Yuan; Goodman, Richard E; Tetteh, Afua O; Lu, Mei; Tripathi, Leena

2017-11-01

Banana Xanthomonas wilt (BXW) disease threatens banana production and food security throughout East Africa. Natural resistance is lacking among common cultivars. Genetically modified (GM) bananas resistant to BXW disease were developed by inserting the hypersensitive response-assisting protein (Hrap) or/and the plant ferredoxin-like protein (Pflp) gene(s) from sweet pepper (Capsicum annuum). Several of these GM banana events showed 100% resistance to BXW disease under field conditions in Uganda. The current study evaluated the potential allergenicity and toxicity of the expressed proteins HRAP and PFLP based on evaluation of published information on the history of safe use of the natural source of the proteins as well as established bioinformatics sequence comparison methods to known allergens (www.AllergenOnline.org and NCBI Protein) and toxins (NCBI Protein). The results did not identify potential risks of allergy and toxicity to either HRAP or PFLP proteins expressed in the GM bananas that might suggest potential health risks to humans. We recognize that additional tests including stability of these proteins in pepsin assay, nutrient analysis and possibly an acute rodent toxicity assay may be required by national regulatory authorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparison of closely related, uncultivated Coxiella tick endosymbiont population genomes reveals clues about the mechanisms of symbiosis.

Science.gov (United States)

Tsementzi, Despina; Castro Gordillo, Juan; Mahagna, Mustafa; Gottlieb, Yuval; Konstantinidis, Konstantinos T

2018-05-01

Understanding the symbiotic interaction between Coxiella-like endosymbionts (CLE) and their tick hosts is challenging due to lack of isolates and difficulties in tick functional assays. Here we sequenced the metagenome of a CLE population from wild Rhipicephalus sanguineus ticks (CRs) and compared it to the previously published genome of its close relative, CLE of R. turanicus (CRt). The tick hosts are closely related sympatric species, and their two endosymbiont genomes are highly similar with only minor differences in gene content. Both genomes encode numerous pseudogenes, consistent with an ongoing genome reduction process. In silico flux balance metabolic analysis (FBA) revealed the excess production of L-proline for both genomes, indicating a possible proline transport from Coxiella to the tick. Additionally, both CR genomes encode multiple copies of the proline/betaine transporter, proP gene. Modelling additional Coxiellaceae members including other tick CLE, did not identify proline as an excreted metabolite. Although both CRs and CRt genomes encode intact B vitamin synthesis pathway genes, which are presumed to underlay the mechanism of CLE-tick symbiosis, the FBA analysis indicated no changes for their products. Therefore, this study provides new testable hypotheses for the symbiosis mechanism and a better understanding of CLE genome evolution and diversity. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

22 CFR 507.8 - Recording keeping of closed meetings.

Science.gov (United States)

2010-04-01

... of a meeting, closed to the public. (b) The Board, after review by the Chairman, shall make promptly... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Recording keeping of closed meetings. 507.8 Section 507.8 Foreign Relations BROADCASTING BOARD OF GOVERNORS RULES FOR IMPLEMENTING OPEN MEETINGS UNDER...

Precision of jaw-closing movements for different jaw gaps.

Science.gov (United States)

Hellmann, Daniel; Becker, Georg; Giannakopoulos, Nikolaos N; Eberhard, Lydia; Fingerhut, Christopher; Rammelsberg, Peter; Schindler, Hans J

2014-02-01

Jaw-closing movements are basic components of physiological motor actions precisely achieving intercuspation without significant interference. The main purpose of this study was to test the hypothesis that, despite an imperfect intercuspal position, the precision of jaw-closing movements fluctuates within the range of physiological closing movements indispensable for meeting intercuspation without significant interference. For 35 healthy subjects, condylar and incisal point positions for fast and slow jaw-closing, interrupted at different jaw gaps by the use of frontal occlusal plateaus, were compared with uninterrupted physiological jaw closing, with identical jaw gaps, using a telemetric system for measuring jaw position. Examiner-guided centric relation served as a clinically relevant reference position. For jaw gaps ≤4 mm, no significant horizontal or vertical displacement differences were observed for the incisal or condylar points among physiological, fast, and slow jaw-closing. However, the jaw positions under these three closing conditions differed significantly from guided centric relation for nearly all experimental jaw gaps. The findings provide evidence of stringent neuromuscular control of jaw-closing movements in the vicinity of intercuspation. These results might be of clinical relevance to occlusal intervention with different objectives. © 2013 Eur J Oral Sci.

Chromatographic resolution of closely related species in pharmaceutical chemistry: dehalogenation impurities and mixtures of halogen isomers.

Science.gov (United States)

Regalado, Erik L; Zhuang, Ping; Chen, Yadan; Makarov, Alexey A; Schafer, Wes A; McGachy, Neil; Welch, Christopher J

2014-01-07

In recent years, the use of halogen-containing molecules has proliferated in the pharmaceutical industry, where the incorporation of halogens, especially fluorine, has become vitally important for blocking metabolism and enhancing the biological activity of pharmaceuticals. The chromatographic separation of halogen-containing pharmaceuticals from associated isomers or dehalogenation impurities can sometimes be quite difficult. In an attempt to identify the best current tools available for addressing this important problem, a survey of the suitability of four chromatographic method development platforms (ultra high-performance liquid chromatography (UHPLC), core shell HPLC, achiral supercritical fluid chromatography (SFC) and chiral SFC) for separating closely related mixtures of halogen-containing pharmaceuticals and their dehalogenated isosteres is described. Of the 132 column and mobile phase combinations examined for each mixture, a small subset of conditions were found to afford the best overall performance, with a single UHPLC method (2.1 × 50 mm, 1.9 μm Hypersil Gold PFP, acetonitrile/methanol based aqueous eluents containing either phosphoric or perchloric acid with 150 mM sodium perchlorate) affording excellent separation for all samples. Similarly, a survey of several families of closely related halogen-containing small molecules representing the diversity of impurities that can sometimes be found in purchased starting materials for synthesis revealed chiral SFC (Chiralcel OJ-3 and Chiralpak IB, isopropanol or ethanol with 25 mM isobutylamine/carbon dioxide) as well as the UHPLC (2.1 × 50 mm, 1.8 μm ZORBAX RRHD Eclipse Plus C18 and the Gold PFP, acetonitrile/methanol based aqueous eluents containing phosphoric acid) as preferred methods.

PSP: rapid identification of orthologous coding genes under positive selection across multiple closely related prokaryotic genomes.

Science.gov (United States)

Su, Fei; Ou, Hong-Yu; Tao, Fei; Tang, Hongzhi; Xu, Ping

2013-12-27

With genomic sequences of many closely related bacterial strains made available by deep sequencing, it is now possible to investigate trends in prokaryotic microevolution. Positive selection is a sub-process of microevolution, in which a particular mutation is favored, causing the allele frequency to continuously shift in one direction. Wide scanning of prokaryotic genomes has shown that positive selection at the molecular level is much more frequent than expected. Genes with significant positive selection may play key roles in bacterial adaption to different environmental pressures. However, selection pressure analyses are computationally intensive and awkward to configure. Here we describe an open access web server, which is designated as PSP (Positive Selection analysis for Prokaryotic genomes) for performing evolutionary analysis on orthologous coding genes, specially designed for rapid comparison of dozens of closely related prokaryotic genomes. Remarkably, PSP facilitates functional exploration at the multiple levels by assignments and enrichments of KO, GO or COG terms. To illustrate this user-friendly tool, we analyzed Escherichia coli and Bacillus cereus genomes and found that several genes, which play key roles in human infection and antibiotic resistance, show significant evidence of positive selection. PSP is freely available to all users without any login requirement at: http://db-mml.sjtu.edu.cn/PSP/. PSP ultimately allows researchers to do genome-scale analysis for evolutionary selection across multiple prokaryotic genomes rapidly and easily, and identify the genes undergoing positive selection, which may play key roles in the interactions of host-pathogen and/or environmental adaptation.

Caracterização de isolados de Xanthomonas campestris pv campestris de sistemas de produção orgânico e reação de brássicas à podridão-negra Characterization of strains of Xanthomonas campestris pv campestris from organic farming systems and reaction of brassicas to black rot

Directory of Open Access Journals (Sweden)

Liliana Andréa dos Santos

2008-12-01

Full Text Available Noventa isolados de Xanthomonas campestris pv. campestris (Xcc de brássicas oriundas de sistemas de produção orgânico das Zonas da Mata e Agreste de Pernambuco foram caracterizados com base na sensibilidade a antibióticos e sulfato de cobre e atividade de esterase. A maioria apresentou alta sensibilidade à tetraciclina (76,6%, eritromicina (63,3% e estreptomicina (63,3%, resistência à amoxicilina (70%, gentamicina (40,0% e norfloxacin (45,5% e média sensibilidade (44,4% ou resistência (44,4% à neomicina. Cinqüenta e cinco isolados de Xcc foram resistentes ao sulfato de cobre na concentração de 50 mg/mL e todos foram sensíveis ao produto na concentração de 200 mg/mL. Atividade de esterase foi apresentada por 92,22% dos isolados. A análise Euclidiana por ligação simples evidenciou variabilidade entre os isolados separando-os em sete grupos de similaridade. Foi estudada também a reação de 14 cultivares de brássicas à podridão-negra, utilizando o isolado "B21" de Xcc. As cultivares diferiram significativamente entre si em relação ao período de incubação, incidência e severidade final da doença. Os maiores valores de severidade final da doença foram verificados em brócolos "Ramoso", couve-flor "Bola de Neve" e "Piracicaba de Verão", e repolho "Chato de Quintal". Os híbridos de couve-chinesa "AF 70", "AF 72", "AF 69" e "AF 66" mostraram-se altamente resistentes à doença, enquanto que brócolos "Ramoso" e "Precoce Piracicaba", couve-flor "Piracicaba de Verão" e "Híbrido Cindy" e repolho "60 Dias" foram medianamente resistentes.Ninety strains of Xanthomonas campestris pv. campestris (Xcc from brassicas grown under organic farming systems in the "Mata" and "Agreste" regions of Pernambuco, Brazil, were characterized based upon sensitivity to antibiotics and copper sulfate, and esterase activity. Most of the strains showed high sensitivity to tetracycline (76.6%, erythromycin (63.3% and streptomycin (63

Reconstruction of molecular phylogeny of closely related Amorphophallus species of India using plastid DNA marker and fingerprinting approaches.

Science.gov (United States)

Gholave, Avinash R; Pawar, Kiran D; Yadav, Shrirang R; Bapat, Vishwas A; Jadhav, Jyoti P

2017-01-01

Plastid DNA markers sequencing and DNA fingerprinting approaches were used and compared for resolving molecular phylogeny of closely related, previously unexplored Amorphophallus species of India. The utility of individual plastid markers namely rbcL , matK , trnH - psbA , trnLC - trnLD , their combined dataset and two fingerprinting techniques viz. RAPD and ISSR were tested for their efficacy to resolves Amorphophallus species into three sections specific clades namely Rhaphiophallus , Conophallus and Amorphophallus . In the present study, sequences of these four plastid DNA regions as well as RAPD and ISSR profiles of 16 Amorphophallus species together with six varieties of two species were generated and analyzed. Maximum likelihood and Bayesian Inference based construction of phylogenetic trees indicated that among the four plastid DNA regions tested individually and their combined dataset, rbcL was found best suited for resolving closely related Amorphophallus species into section specific clades. When analyzed individually, rbcL exhibited better discrimination ability than matK , trnH - psbA , trnLC - trnLD and combination of all four tested plastid markers. Among two fingerprinting techniques used, the resolution of Amorphophallus species using RAPD was better than ISSR and combination of RAPD +ISSR and in congruence with resolution based on rbcL .

Closed forms for conformally flat Green's functions

International Nuclear Information System (INIS)

Brown, M.R.; Grove, P.G.; Ottewill, A.C.

1981-01-01

A closed form is obtained for the massless scalar Green's function on Rindler space. This is related by conformal transformation to the Green's function for a massless, conformally coupled scalar field on the open Einstein universe. A closed form is also obtained for the corresponding Green's function on the Einstein static universe. (author)

Phenology, growth, and fecundity as determinants of distribution in closely related nonnative taxa

Science.gov (United States)

Marushia, Robin G.; Brooks, Matthew L.; Holt, Jodie S.

2012-01-01

Invasive species researchers often ask: Why do some species invade certain habitats while others do not? Ecological theories predict that taxonomically related species may invade similar habitats, but some related species exhibit contrasting invasion patterns. Brassica nigra, Brassica tournefortii, and Hirschfeldia incana are dominant, closely related nonnative species that have overlapping, but dissimilar, distributions. Brassica tournefortii is rapidly spreading in warm deserts of the southwestern United States, whereas B. nigra and H. incana are primarily limited to semiarid and mesic regions. We compared traits of B. tournefortii that might confer invasiveness in deserts with those of related species that have not invaded desert ecosystems. Brassica tournefortii, B. nigra and H. incana were compared in controlled experiments conducted outdoors in a mesic site (Riverside, CA) and a desert site (Blue Diamond, NV), and in greenhouses, over 3 yr. Desert and mesic B. tournefortii populations were also compared to determine whether locally adapted ecotypes contribute to desert invasion. Experimental variables included common garden sites and soil water availability. Response variables included emergence, growth, phenology, and reproduction. There was no evidence for B. tournefortii ecotypes, but B. tournefortii had a more rapid phenology than B. nigra or H. incana. Brassica tournefortii was less affected by site and water availability than B. nigra and H. incana, but was smaller and less fecund regardless of experimental conditions. Rapid phenology allows B. tournefortii to reproduce consistently under variable, stressful conditions such as those found in Southwestern deserts. Although more successful in milder, mesic ecosystems, B. nigra and H. incana may be limited by their ability to reproduce under desert conditions. Rapid phenology and drought response partition invasion patterns of nonnative mustards along a gradient of aridity in the southwestern United States

Migratory New World blackbirds (icterids are more neophobic than closely related resident icterids.

Directory of Open Access Journals (Sweden)

Claudia Mettke-Hofmann

Full Text Available Environments undergo short-term and long-term changes due to natural or human-induced events. Animals differ in their ability to cope with such changes which can be related to their ecology. Changes in the environment often elicit avoidance reactions (neophobia which protect animals from dangerous situations but can also inhibit exploration and familiarization with novel situations and thus, learning about new resources. Studies investigating the relationship between a species' ecology and its neophobia have so far been restricted to comparing only a few species and mainly in captivity. The current study investigated neophobia reactions to experimentally-induced changes in the natural environment of six closely-related blackbird species (Icteridae, including two species represented by two distinct populations. For analyses, neophobic reactions (difference in number of birds feeding and time spent feeding with and without novel objects were related to several measures of ecological plasticity and the migratory strategy (resident or migratory of the population. Phylogenetic relationships were incorporated into the analysis. The degree of neophobia was related to migratory strategy with migrants expressing much higher neophobia (fewer birds feeding and for a shorter time with objects present than residents. Furthermore, neophobia showed a relationship to diet breadth with fewer individuals of diet generalists than specialists returning when objects were present supporting the dangerous niche hypothesis. Residents may have evolved lower neophobia as costs of missing out on opportunities may be higher for residents than migrants as the former are restricted to a smaller area. Lower neophobia allows them approaching changes in the environment (e.g. novel objects quickly, thereby securing access to resources. Additionally, residents have a greater familiarity with similar situations in the area than migrants and the latter may, therefore, initially

Evolution of Enzymatic Activities in the Enolase Superfamily: L-Fuconate Dehydratase from Xanthomonas campestris

Energy Technology Data Exchange (ETDEWEB)

Yew,W.; Fedorov, A.; Fedorov, E.; Rakus, J.; Pierce, R.; Almo, S.; Gerlt, J.

2006-01-01

Many members of the mechanistically diverse enolase superfamily have unknown functions. In this report the authors use both genome (operon) context and screening of a library of acid sugars to assign the L-fuconate dehydratase (FucD) function to a member of the mandelate racemase (MR) subgroup of the superfamily encoded by the Xanthomonas campestris pv. campestris str. ATCC 33913 genome (GI: 21233491). Orthologues of FucD are found in both bacteria and eukaryotes, the latter including the rTS beta protein in Homo sapiens that has been implicated in regulating thymidylate synthase activity. As suggested by sequence alignments and confirmed by high-resolution structures in the presence of active site ligands, FucD and MR share the same active site motif of functional groups: three carboxylate ligands for the essential Mg2+ located at the ends of th third, fourth, and fifth-strands in the (/)7-barrel domain (Asp 248, Glu 274, and Glu 301, respectively), a Lys-x-Lys motif at the end of the second-strand (Lys 218 and Lys 220), a His-Asp dyad at the end of the seventh and sixth-strands (His 351 and Asp 324, respectively), and a Glue at the end of the eighth-strand (Glu 382). The mechanism of the FucD reaction involves initial abstraction of the 2-proton by Lys 220, acid catalysis of the vinylogous-elimination of the 3-OH group by His 351, and stereospecific ketonization of the resulting 2-keto-3-deoxy-L-fuconate product. Screening of the library of acid sugars revealed substrate and functional promiscuity: In addition to L-fuconate, FucD also catalyzes the dehydration of L-galactonate, D-arabinonate, D-altronate, L-talonate, and D-ribonate. The dehydrations of L-fuconate, L-galactonate, and D-arabinonate are initiated by abstraction of the 2-protons by Lys 220. The dehydrations of L-talonate and D-ribonate are initiated by abstraction of the 2-protons by His 351; however, protonation of the enediolate intermediates by the conjugate acid of Lys 220 yields L

Structure of XC6422 from Xanthomonas campestris at 1.6 Å resolution: a small serine α/β-hydrolase

Energy Technology Data Exchange (ETDEWEB)

Yang, Chao-Yu; Chin, Ko-Hsin [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China); Chou, Chia-Cheng; Wang, Andrew H.-J. [Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei,Taiwan (China); Core Facility for Protein Crystallography, Academia Sinica, Nankang, Taipei,Taiwan (China); Chou, Shan-Ho, E-mail: shchou@nchu.edu.tw [Institute of Biochemistry, National Chung-Hsing University, Taichung 40227,Taiwan (China)

2006-06-01

The crystal structure of a conserved hypothetical protein from X. campestris has been determined to a resolution of 1.6 Å. The determined X. campestris structure shows that it belongs to the superfamily of serine α/β hydrolase, with an extra strand preceding the first β-strand to lead to extensive subunit interactions in the crystal. XC6422 is a conserved hypothetical protein from Xanthomonas campestris pathovar campestris (Xcc), a Gram-negative yellow-pigmented pathogenic bacterium that causes black rot, one of the major worldwide diseases of cruciferous crops. The protein consists of 220 amino acids and its structure has been determined to 1.6 Å resolution using the multi-wavelength anomalous dispersion (MAD) method. Although it has very low sequence identity to protein sequences in the PDB (less than 20%), the determined structure nevertheless shows that it belongs to the superfamily of serine α/β-hydrolases, with an active site that is fully accessible to solvent owing to the absence of a lid domain. Modelling studies with the serine esterase inhibitor E600 indicate that XC6422 adopts a conserved Ser-His-Asp catalytic triad common to this superfamily and has a preformed oxyanion hole for catalytic activation. These structural features suggest that XC6422 is most likely to be a hydrolase active on a soluble ester or a small lipid. An extra strand preceding the first β-strand in the canonical α/β-hydrolase fold leads to extensive subunit interactions between XC6422 monomers, which may explain why XC6422 crystals of good diffraction quality can grow to dimensions of up to 1.5 mm in a few days.

Closely related freshwater macrophyte species, Ceratophyllum demersum and C. submersum, differ in temperature response

DEFF Research Database (Denmark)

Hyldgaard, Benita; Sorrell, Brian Keith; Brix, Hans

2014-01-01

1. The importance of temperature responses of photosynthesis and respiration in determining species distributions was compared in two closely related freshwater macrophytes, Ceratophyllum demersum and C. submersum. The two species differed significantly in response to temperature in the short...... and distributional patterns corresponded well with the long-term (weeks) results obtained, but with some important deviations. The long-term responses of the two species to low temperature (12 °C) were more similar than expected. In contrast, high temperature (35 °C), which stimulated photosynthesis in C. submersum...... in the short term, inhibited photosynthesis in the long term and resulted in lower growth rates of C. submersum, both compared to C. demersum and to growth rates at intermediate temperatures (18 and 25 °C). 3. The long-term acclimation strategy differed between the two species. Ceratophyllum demersum achieved...

On H-closed and U-closed functions | Cammaroto | Quaestiones ...

African Journals Online (AJOL)

In this article, we extend the work on H-closed functions started by Cammaroto, Fedorchuk and Porter in 1998. Also, U-closed functions are introduced and characterized in terms of filters and adherence. The hereditary and productivity properties are examined and developed for both H-closed and U-closed functions.

On θ-generalized closed sets

Directory of Open Access Journals (Sweden)

Julian Dontchev

1999-01-01

θ-generalized Λ-sets and R0-, T1/2- and T1-spaces are characterized. The relations with other notions directly or indirectly connected with generalized closed sets are investigated. The notion of TGO-connectedness is introduced.

Posttraumatic Stress Disorder After Bereavement: Early Psychological Sequelae of Losing a Close Relative Due to Terminal Cancer

DEFF Research Database (Denmark)

Kristensen, T. E.; Elklit, A.; Karstoft, K. I.

2012-01-01

Very few studies have investigated posttraumatic stress disorder (PTSD) as a consequence of bereavement from terminal illness. Therefore, knowledge on the traumatizing effects of bereavement and risk factors for traumatization from bereavement is rather sparse. This study investigated prevalence...... and predictors of PTSD in a group of people who had recently lost a close relative due to incurable cancer. The participants were 132 persons who were assessed with the Harvard Trauma Questionnaire, the Trauma Symptom Checklist, and the Crisis Support Scale. One month after the loss, 29.5% of the subjects had...

Closed-Loop Surface Related Multiple Estimation

NARCIS (Netherlands)

Lopez Angarita, G.A.

2016-01-01

Surface-related multiple elimination (SRME) is one of the most commonly used methods for suppressing surface multiples. However, in order to obtain an accurate surface multiple estimation, dense source and receiver sampling is required. The traditional approach to this problem is performing data

Four Closely Related HIV-1 CRF01_AE/CRF07_BC Recombinant Forms Identified in East China.

Science.gov (United States)

Li, Fan; Li, Yuxueyun; Feng, Yi; Hu, Jing; Ruan, Yuhua; Xing, Hui; Shao, Yiming

2017-07-01

Five near full-length genomes of novel second-generation HIV-1 recombinant virus (JS150021, JS150029, JS150129, JS150132, and AH150183) were identified from five HIV-positive people in Jiangsu and Anhui province, east China. Phylogenic analyses showed that these five sequences are all composed of two well-established circulating recombinant forms (CRFs) CRF07_BC and CRF01_AE, grouped into four new discovered recombinant forms, which show several very similar but not identical recombinant breakpoints. The four recombinant forms are also identified to be a sort of family or related viruses, seems to be the results of different recombination events. The emergence of a serious new closely related CRF07_BC/CRF01_AE recombinant strain indicates the increasing complexity of sexual transmission of the HIV-1 epidemic in China.

Exact results for ABJ Wilson loops and open-closed duality

Energy Technology Data Exchange (ETDEWEB)

Hatsuda, Yasuyuki [Département de Physique Théorique et section de Mathématiques, Université de Genève,Genève, CH-1211 (Switzerland); Okuyama, Kazumi [Department of Physics, Shinshu University,Matsumoto 390-8621 (Japan)

2016-10-24

We find new exact relations between the partition function and vacuum expectation values (VEVs) of 1/2 BPS Wilson loops in ABJ theory, which allow us to predict the large N expansions of the 1/2 BPS Wilson loops from known results of the partition function. These relations are interpreted as an open-closed duality where the closed string background is shifted by the insertion of Wilson loops due to a back-reaction. Using the connection between ABJ theory and the topological string on local ℙ{sup 1}×ℙ{sup 1}, we explicitly write down non-trivial relations between open and closed string amplitudes.

A closed-loop hybrid physiological model relating to subjects under physical stress.

Science.gov (United States)

El-Samahy, Emad; Mahfouf, Mahdi; Linkens, Derek A

2006-11-01

The objective of this research study is to derive a comprehensive physiological model relating to subjects under physical stress conditions. The model should describe the behaviour of the cardiovascular system, respiratory system, thermoregulation and brain activity in response to physical workload. An experimental testing rig was built which consists of recumbent high performance bicycle for inducing the physical load and a data acquisition system comprising monitors and PCs. The signals acquired and used within this study are the blood pressure, heart rate, respiration, body temperature, and EEG signals. The proposed model is based on a grey-box based modelling approach which was used because of the sufficient level of details it provides. Cardiovascular and EEG Data relating to 16 healthy subject volunteers (data from 12 subjects were used for training/validation and the data from 4 subjects were used for model testing) were collected using the Finapres and the ProComp+ monitors. For model validation, residual analysis via the computing of the confidence intervals as well as related histograms was performed. Closed-loop simulations for different subjects showed that the model can provide reliable predictions for heart rate, blood pressure, body temperature, respiration, and the EEG signals. These findings were also reinforced by the residual analyses data obtained, which suggested that the residuals were within the 90% confidence bands and that the corresponding histograms were of a normal distribution. A higher intelligent level was added to the model, based on neural networks, to extend the capabilities of the model to predict over a wide range of subjects dynamics. The elicited physiological model describing the effect of physiological stress on several physiological variables can be used to predict performance breakdown of operators in critical environments. Such a model architecture lends itself naturally to exploitation via feedback control in a 'reverse

Wing pattern morphology of three closely related Melitaea (Lepidoptera, Nymphalidae) species reveals highly inaccurate external morphology-based species identification

OpenAIRE

Jugovic,Jure; Koren,Toni

2014-01-01

Wing morphology of the three closely related species of Melitaea – M. athalia (Rottemburg, 1775), M. aurelia (Nickerl, 1850) and M. britomartis Assmann, 1847 – co-occurring in the Balkans (SE Europe) was investigated in detail through visual inspection, morphometric analysis and multivariate statistical analysis. Results are compared to recent phylogenetic studies, searching for concordant patterns and discrepancies between the two approaches. The morphology of the genitalic structures is als...

Masticatory function and oral health-related quality of life in patients after partial maxillectomies with closed or open defects.

Science.gov (United States)

Said, Mohamed M; Otomaru, Takafumi; Yeerken, Yesiboli; Taniguchi, Hisashi

2017-07-01

The healing pattern after surgical resection of tumors of the oral cavity involving the maxilla may vary from one patient to another. The result may be open communication between the oral and nasal cavities (open defect) or complete oronasal separation after healing of the defect area (closed defect). The purpose of this clinical study was to compare masticatory function and oral health-related quality of life (OHRQoL) between patients with closed and open defects who had undergone a partial maxillectomy and were wearing dentomaxillary prostheses. Thirty-eight participants who had undergone a partial maxillectomy and who were wearing dentomaxillary prostheses were enrolled between September 2014 and April 2016. Participants were assigned to 2 groups according to the type of defect after healing: 19 participants had a closed defect, and 19 participants had an open defect. Masticatory function was evaluated objectively and subjectively. The objective measurement was food-mixing ability, which was assessed using color-changeable chewing gum. The subjective measurement was perceived mastication ability, rated as a masticatory score based on the patient's responses to a 35-item food intake questionnaire. OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI). The GOHAI questionnaire consists of 12 items reflecting 3 hypothesized domains of the impact of oral disease: physical function, psychosocial function, and pain or discomfort. Differences in the scores obtained by the 3 measurements were compared between the 2 groups, using the Wilcoxon rank-sum test (α=.05). No significant differences were seen between the 2 groups in objective mixing ability, subjective masticatory score, or GOHAI (P>.05). Regarding the GOHAI physical function domain, only the swallowing item was significantly lower (P=.025) in participants with an open defect than in participants with a closed defect. Regarding the GOHAI psychological function domain, the item related to

Inducible Expression of the De-Novo Designed Antimicrobial Peptide SP1-1 in Tomato Confers Resistance to Xanthomonas campestris pv. vesicatoria.

Directory of Open Access Journals (Sweden)

Areli Herrera Diaz

Full Text Available Antimicrobial peptides (AMPs are small peptides with less than 50 amino acids and are part of the innate immune response in almost all organisms, including bacteria, vertebrates, invertebrates and plants. AMPs are active against a broad-spectrum of pathogens. The inducible expression of AMPs in plants is a promising approach to combat plant pathogens with minimal negative side effects, such as phytotoxicity or infertility. In this study, inducible expression of the de-novo designed AMP SP1-1 in Micro Tom tomato protected tomato fruits against bacterial spot disease caused by Xanthomonas campestris pv. vesicatoria. The peptide SP1-1 was targeted to the apoplast which is the primary infection site for plant pathogens, by fusing SP1-1 peptide to the signal peptide RsAFP1 of radish (Raphanus sativus. The pathogen inducibility of the expression was enabled by using an optimized inducible 4XW2/4XS promoter. As a result, the tomato fruits of independently generated SP1-1 transgenic lines were significantly more resistant to X. campestris pv. vesicatoria than WT tomato fruits. In transgenic lines, bacterial infection was reduced up to 65% in comparison to the infection of WT plants. Our study demonstrates that the combination of the 4XW2/4XS cis-element from parsley with the synthetic antimicrobial peptide SP1-1 is a good alternative to protect tomato fruits against infections with X. campestris pv. vesicatoria.

A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

Science.gov (United States)

Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

2013-06-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

OpenAIRE

Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

Preadolescents' and Adolescents' Online Communication and Their Closeness to Friends

Science.gov (United States)

Valkenburg, Patti M.; Peter, Jochen

2007-01-01

The 1st goal of this study was to investigate how online communication is related to the closeness of existing friendships. Drawing from a sample of 794 preadolescents and adolescents, the authors found that online communication was positively related to the closeness of friendships. However, this effect held only for respondents who primarily…

Vibrio vulnificus phage PV94 is closely related to temperate phages of V. cholerae and other Vibrio species.

Directory of Open Access Journals (Sweden)

Mark Pryshliak

Full Text Available BACKGROUND: Vibrio vulnificus is an important pathogen which can cause serious infections in humans. Yet, there is limited knowledge on its virulence factors and the question whether temperate phages might be involved in pathogenicity, as is the case with V. cholerae. Thus far, only two phages (SSP002 and VvAW1 infecting V. vulnificus have been genetically characterized. These phages were isolated from the environment and are not related to Vibrio cholerae phages. The lack of information on temperate V. vulnificus phages prompted us to isolate those phages from lysogenic strains and to compare them with phages of other Vibrio species. RESULTS: In this study the temperate phage PV94 was isolated from a V. vulnificus biotype 1 strain by mitomycin C induction. PV94 is a myovirus whose genome is a linear double-stranded DNA of 33,828 bp with 5'-protruding ends. Sequence analysis of PV94 revealed a modular organization of the genome. The left half of the genome comprising the immunity region and genes for the integrase, terminase and replication proteins shows similarites to V. cholerae kappa phages whereas the right half containing genes for structural proteins is closely related to a prophage residing in V. furnissii NCTC 11218. CONCLUSION: We present the first genomic sequence of a temperate phage isolated from a human V. vulnificus isolate. The sequence analysis of the PV94 genome demonstrates the wide distribution of closely related prophages in various Vibrio species. Moreover, the mosaicism of the PV94 genome indicates a high degree of horizontal genetic exchange within the genus Vibrio, by which V. vulnificus might acquire virulence-associated genes from other species.

Point Cloud Based Relative Pose Estimation of a Satellite in Close Range

Directory of Open Access Journals (Sweden)

Lujiang Liu

2016-06-01

Full Text Available Determination of the relative pose of satellites is essential in space rendezvous operations and on-orbit servicing missions. The key problems are the adoption of suitable sensor on board of a chaser and efficient techniques for pose estimation. This paper aims to estimate the pose of a target satellite in close range on the basis of its known model by using point cloud data generated by a flash LIDAR sensor. A novel model based pose estimation method is proposed; it includes a fast and reliable pose initial acquisition method based on global optimal searching by processing the dense point cloud data directly, and a pose tracking method based on Iterative Closest Point algorithm. Also, a simulation system is presented in this paper in order to evaluate the performance of the sensor and generate simulated sensor point cloud data. It also provides truth pose of the test target so that the pose estimation error can be quantified. To investigate the effectiveness of the proposed approach and achievable pose accuracy, numerical simulation experiments are performed; results demonstrate algorithm capability of operating with point cloud directly and large pose variations. Also, a field testing experiment is conducted and results show that the proposed method is effective.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

Science.gov (United States)

Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis

Directory of Open Access Journals (Sweden)

Abdjad Asih Nawangsih

2011-04-01

Full Text Available Xanthomonas oryzae pv oryzae the Causal Agent of Bacterial Leaf Blight of rice: Isolation, Characterization, and Study of Transposon Mutagenesis. X. oryzae pv. oryzae (Xoo causes bacterial leaf blight (BLB of rice (Oryza sativa L., a major disease that constrains production of the staple crop in many countries of the world. Identification of X. oryzae pv. oryzae (Xoo was conducted based on the disease symptoms, pathogenicity, morphological, physiological, and genetic characteristics of bacterial cultures isolated from the infected plants. Fifty bacterial isolates predicted as Xoo have been successfully isolated. They are aerobic, rod shaped, and Gram negative bacteria. The isolates were evaluated for their hypersensitivity in tobacco and pathogenicity in rice plant. Fifty isolates induced hypersensitive reaction in tobacco and showed pathogenicity symptom in rice in different length. Based on physiological test, hypersensitivity and pathogenicity reactions, three bacterial isolates strongly predicted as Xoo, i.e. STG21, STG42, and STG46, were non indole formation, non pigment fluorescent, hydrolyzed casein, catalase activity positive, but negative oxidase. Partial sequencing of 16S rRNA genes of STG21 and STG42 showed 80% and 82% homology with X. oryzae, respectively, while STG46 showed 84% homology with X. campestris. Mini-Tn5 transposon mutagenesis of STG21 generated one of the mutants (M5 lossed it’s ability to induce hypersensitive reaction in tobacco plant and deficient in pathogenicity on rice. The lesion length of rice leaf caused by the mutant M5 decreased up to 80%.

Links between Adolescents’ Closeness to Adoptive Parents and Attachment Style in Young Adulthood

Science.gov (United States)

Grant-Marsney, Holly A.; Grotevant, Harold D.; Sayer, Aline G.

2014-01-01

This study examined whether adolescents’ closeness to adoptive parents (APs) predicted attachment styles in close relationships outside their family during young adulthood. In a longitudinal study of domestic infant adoptions, closeness to adoptive mother and adoptive father was assessed in 156 adolescents (M = 15.7 years). Approximately nine years later (M = 25.0 years), closeness to parents was assessed again as well as attachment style in their close relationships. Multilevel modeling was used to predict attachment style in young adulthood from the average and discrepancy of closeness to adolescents’ adoptive mothers and fathers and the change over time in closeness to APs. Less avoidant attachment style was predicted by stronger closeness to both APs during adolescence. Increased closeness to APs over time was related to less anxiety in close relationships. Higher closeness over time to either AP was related to less avoidance and anxiety in close relationships. PMID:25859067

Links between Adolescents' Closeness to Adoptive Parents and Attachment Style in Young Adulthood.

Science.gov (United States)

Grant-Marsney, Holly A; Grotevant, Harold D; Sayer, Aline G

2015-04-01

This study examined whether adolescents' closeness to adoptive parents (APs) predicted attachment styles in close relationships outside their family during young adulthood. In a longitudinal study of domestic infant adoptions, closeness to adoptive mother and adoptive father was assessed in 156 adolescents ( M = 15.7 years). Approximately nine years later ( M = 25.0 years), closeness to parents was assessed again as well as attachment style in their close relationships. Multilevel modeling was used to predict attachment style in young adulthood from the average and discrepancy of closeness to adolescents' adoptive mothers and fathers and the change over time in closeness to APs. Less avoidant attachment style was predicted by stronger closeness to both APs during adolescence. Increased closeness to APs over time was related to less anxiety in close relationships. Higher closeness over time to either AP was related to less avoidance and anxiety in close relationships.

A rare sugar, d-allose, confers resistance to rice bacterial blight with upregulation of defense-related genes in Oryza sativa.

Science.gov (United States)

Kano, Akihito; Gomi, Kenji; Yamasaki-Kokudo, Yumiko; Satoh, Masaru; Fukumoto, Takeshi; Ohtani, Kouhei; Tajima, Shigeyuki; Izumori, Ken; Tanaka, Keiji; Ishida, Yutaka; Tada, Yasuomi; Nishizawa, Yoko; Akimitsu, Kazuya

2010-01-01

We investigated responses of rice plant to three rare sugars, d-altrose, d-sorbose, and d-allose, due to establishment of mass production methods for these rare sugars. Root growth and shoot growth were significantly inhibited by d-allose but not by the other rare sugars. A large-scale gene expression analysis using a rice microarray revealed that d-allose treatment causes a high upregulation of many defense-related, pathogenesis-related (PR) protein genes in rice. The PR protein genes were not upregulated by other rare sugars. Furthermore, d-allose treatment of rice plants conferred limited resistance of the rice against the pathogen Xanthomonas oryzae pv. oryzae but the other tested sugars did not. These results indicate that d-allose has a growth inhibitory effect but might prove to be a candidate elicitor for reducing disease development in rice.

Ortholog Alleles at Xa3/Xa26 Locus Confer Conserved Race-Specific Resistance against Xanthomonas oryzae in Rice

Institute of Scientific and Technical Information of China (English)

Hong-Jing Li; Xiang-Hua Li; Jing-Hua Xiao; Rod A. Wing; Shi-Ping Wang

2012-01-01

The rice disease resistance (R) gene Xa3/Xa26 (having also been named Xa3 and Xa26) against Xanthomonas oryzae pv.oryzae (Xoo),which causes bacterial blight disease,belongs to a multiple gene family clustered in chromosome 11 and is from an AA genome rice cultivar (Oryza sativa L.).This family encodes leucine-rich repeat (LRR) receptor kinasetype proteins.Here,we show that the orthologs (alleles) of Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3,from wild Oryza species O.officinalis (CC genome) and O.minuta (BBCC genome),respectively,were also R genes against Xoo.Xa3/Xa26-2 and Xa3/Xa26-3 conferred resistance to 16 of the 18 Xoo strains examined.Comparative sequence analysis of the Xa3/Xa26 families in the two wild Oryza species showed that Xa3/Xa26-3 appeared to have originated from the CC genome of O.minuta.The predicted proteins encoded by Xa3/Xa26,Xa3/Xa26-2,and Xa3/Xa26-3 share 91-99％ sequence identity and 94-99％ sequence similarity.Transgenic plants carrying a single copy of Xa3/Xa26,Xa3/Xa26-2,or Xa3/Xa26-3,in the same genetic background,showed a similar resistance spectrum to a set of Xoo strains,although plants carrying Xa3/Xa26-2 or Xa3/Xa26-3 showed lower resistance levels than the plants carrying Xa3/Xa26.These results suggest that the Xa3/Xa26 locus predates the speciation of A and C genome,which is approximately 7.5 million years ago.Thus,the resistance specificity of this locus has been conserved for a long time.

A condition closely mimicking IgG4-related disease despite the absence of serum IgG4 elevation and IgG4-positive plasma cell infiltration.

Science.gov (United States)

Hara, Satoshi; Kawano, Mitsuhiro; Mizushima, Ichiro; Yamada, Kazunori; Fujita, Kentaro; Harada, Kenichi; Matsumura, Masami; Yamagishi, Masakazu; Sato, Yasuharu; Yamaguchi, Yutaka; Nakanuma, Yasuni; Nagata, Michio

2016-09-01

We describe a 74-year-old Japanese man with systemic fibroinflammatory conditions closely resembling those of immunoglobulin G4-related disease (IgG4-RD). Radiology and histology showed characteristics of IgG4-related tubulointerstitial nephritis, despite normal serum IgG4 value and scanty IgG4-positive plasma cell infiltration in each organ. This case suggests that a condition closely mimicking IgG4-RD may develop without IgG4-positive plasma cells and those exceptional cases should also be taken into account in the differential diagnosis of IgG4-RD.

A study on some welfare-related parameters of hDAF transgenic pigs when compared with their conventional close relatives.

Science.gov (United States)

Martelli, G; Sardi, L; Stancampiano, L; Govoni, N; Zannoni, A; Nannoni, E; Forni, M; Bacci, M L

2014-05-01

Pigs are increasingly used in medical research as transgenic laboratory animals; however, little knowledge is presently available concerning their welfare assessment. The aim of the present study was to investigate some welfare-related parameters of transgenic pigs intended for xenotrasplantation (human decay-accelerating factor (hDAF)) when compared with their conventional (i.e. not transgenic) close relatives (full sibs and half sibs). A total of 14 Large White female transgenic pigs and 10 female non-transgenic (conventional) pigs from four litters were used. All pigs were from the same conventional boar, donor of the semen treated for sperm-mediated gene transfer. During the experiment, BW ranged from 50 to about 80 kg and pigs were weighed at the beginning and at the end of the experiment. Animals were subjected to a set of behavioural tests: a human approach test (HAT), a novel object test (NOT) and an open-door test (ODT). Food preferences were tested through the offer of different foods (banana, apple, carrot, cracker and lemon). During a 4-day period, pigs were diurnally videotaped to study the prevalence of the different behaviours and social interactions (aggressive and non-aggressive interactions). At the end of the trial, cortisol level had been assessed on bristles. No significant differences (P>0.05) were observed between hDAF transgenic and conventional pigs with respect to growth traits, reactivity towards unexpected situations (HAT, NOT, ODT), food preferences, main behavioural traits, social interactions and hair cortisol.

Graph topologies on closed multifunctions

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Giuseppe Di Maio

2003-10-01

Full Text Available In this paper we study function space topologies on closed multifunctions, i.e. closed relations on X x Y using various hypertopologies. The hypertopologies are in essence, graph topologies i.e topologies on functions considered as graphs which are subsets of X x Y . We also study several topologies, including one that is derived from the Attouch-Wets filter on the range. We state embedding theorems which enable us to generalize and prove some recent results in the literature with the use of known results in the hyperspace of the range space and in the function space topologies of ordinary functions.

Distinctive Features of Oral Cancer in Changhua County: High Incidence, Buccal Mucosa Preponderance, and a Close Relation to Betel Quid Chewing Habit

Directory of Open Access Journals (Sweden)

Che-Chun Su

2007-01-01

Conclusion: We conclude that the high incidence and buccal mucosa preponderance of oral cancer in Changhua may have an exceptionally close relation with patients' betel quid chewing habit, and other unknown etiologic factors may also be present locally. [J Formos Med Assoc 2007;106(3:225-233

Ademe et Vous. Research Newsletter No. 13, December 2015. Air quality and climate change: two closely-related issues

International Nuclear Information System (INIS)

Varet, Anne; Guignard, Stephanie

2015-12-01

This Research letter is the last in a series of three letters dedicated to climate change, produced in the run up to COP21. It covers the research carried out and the results obtained, with the support of ADEME, in terms of air quality and climate change. Content: - Air quality and climate change: two closely-related issues; - Significant Results: Implementing solutions to improve air quality in a wider context of climate change; - Meeting...: Vincent-Henri Peuch and Nathalie Poisson: 'Air and climate quality - developing joint solutions: a necessity'

CatB is Critical for Total Catalase Activity and Reduces Bactericidal Effects of Phenazine-1-Carboxylic Acid on Xanthomonas oryzae pv. oryzae and X. oryzae pv. oryzicola.

Science.gov (United States)

Pan, Xiayan; Wu, Jian; Xu, Shu; Duan, Yabing; Zhou, Mingguo

2017-02-01

Rice bacterial leaf blight, caused by Xanthomonas oryzae pv. oryzae, and rice bacterial leaf streak, caused by X. oryzae pv. oryzicola, are major diseases of rice. Phenazine-1-carboxylic acid (PCA) is a natural product that is isolated from Pseudomonas spp. and is used to control many important rice diseases in China. We previously reported that PCA disturbs the redox balance, which results in the accumulation of reactive oxygen species in X. oryzae pv. oryzae. In this study, we found that PCA significantly upregulated the transcript levels of catB and katE, which encode catalases, and that PCA sensitivity was reduced when X. oryzae pvs. oryzae and oryzicola were cultured with exogenous catalase. Furthermore, catB deletion mutants of X. oryzae pvs. oryzae and oryzicola showed dramatically decreased total catalase activity, increased sensitivity to PCA, and reduced virulence in rice. In contrast, deletion mutants of srpA and katG, which also encode catalases, exhibited little change in PCA sensitivity. The results indicate that catB in both X. oryzae pvs. oryzae and oryzicola encodes a catalase that helps protect the bacteria against PCA-induced stress.

Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species.

Science.gov (United States)

Du, Shuhui; Wang, Zhaoshan; Ingvarsson, Pär K; Wang, Dongsheng; Wang, Junhui; Wu, Zhiqiang; Tembrock, Luke R; Zhang, Jianguo

2015-10-01

Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P. tremula and P. davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P. tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles in the formation of the disjunct distributions and divergence of these three Populus species. © 2015 John Wiley & Sons Ltd.

Drought responses of three closely related Caragana species: implication for their vicarious distribution.

Science.gov (United States)

Ma, Fei; Na, Xiaofan; Xu, Tingting

2016-05-01

Drought is a major environmental constraint affecting growth and distribution of plants in the desert region of the Inner Mongolia plateau. Caragana microphylla, C. liouana, and C. korshinskii are phylogenetically close but distribute vicariously in Mongolia plateau. To gain a better understanding of the ecological differentiation between these three species, we examined the leaf gas exchange, growth, water use efficiency, biomass accumulation and allocation by subjecting their seedlings to low and high drought treatments in a glasshouse. Increasing drought stress had a significant effect on many aspects of seedling performance in all species, but the physiology and growth varied with species in response to drought. C. korshinskii exhibited lower sensitivity of photosynthetic rate and growth, lower specific leaf area, higher biomass allocation to roots, higher levels of water use efficiency to drought compared with the other two species. Only minor interspecific differences in growth performances were observed between C. liouana and C. microphylla. These results indicated that faster seedling growth rate and more efficient water use of C. korshinskii should confer increased drought tolerance and facilitate its establishment in more severe drought regions relative to C. liouana and C. microphylla.

Closeness, autonomy, equity, and relationship satisfaction in lesbian couples

NARCIS (Netherlands)

Schreurs, KMG; Buunk, BP

1996-01-01

It is often assumed that in lesbian relationships a high degree of closeness is reached at the expense of autonomy of the partners. The present study among 119 Dutch lesbian couples examined the effect on relational satisfaction of two dimensions of closeness, emotional dependency and intimacy, and

Closed medical negligence claims can drive patient safety and reduce litigation.

Science.gov (United States)

Pegalis, Steven E; Bal, B Sonny

2012-05-01

Medical liability reform is viewed by many physician groups as a means of reducing medical malpractice litigation and lowering healthcare costs. However, alternative approaches such as closed medical negligence claims data may also achieve these goals. We asked whether information gleaned from closed claims related to medical negligence could promote patient safety and reduce costs related to medical liability. Specifically, we investigated whether physician groups have examined such data to identify error patterns and to then institute specific patient treatment protocols. We searched for medical societies that have systematically examined closed medical negligence claims in their specialty to develop specific standards of physician conduct. We then searched the medical literature for published evidence of the efficacy, if any, related to the patient safety measures thus developed. Anesthesia and obstetric physician societies have successfully targeted costs and related concerns arising from medical malpractice lawsuits by using data from closed claims to develop patient safety and treatment guidelines. In both specialties, after institution of safety measures derived from closed medical negligence claims, the incidence and costs related to medical malpractice decreased and physician satisfaction improved. Tort reform, in the form of legislatively prescribed limits on damages arising from lawsuits, is not the only means of addressing the incidence and costs related to medical malpractice litigation. As the experience of anesthesia and obstetric physicians has demonstrated, safety guidelines derived from analyzing past medical malpractice litigation can achieve the same goals while also promoting patient safety.

Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

Directory of Open Access Journals (Sweden)

QUEIROZ J. M.

2002-01-01

Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

The Dynamic Genome and Transcriptome of the Human Fungal Pathogen Blastomyces and Close Relative Emmonsia.

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José F Muñoz

2015-10-01

Full Text Available Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics

The Dynamic Genome and Transcriptome of the Human Fungal Pathogen Blastomyces and Close Relative Emmonsia.

Science.gov (United States)

Muñoz, José F; Gauthier, Gregory M; Desjardins, Christopher A; Gallo, Juan E; Holder, Jason; Sullivan, Thomas D; Marty, Amber J; Carmen, John C; Chen, Zehua; Ding, Li; Gujja, Sharvari; Magrini, Vincent; Misas, Elizabeth; Mitreva, Makedonka; Priest, Margaret; Saif, Sakina; Whiston, Emily A; Young, Sarah; Zeng, Qiandong; Goldman, William E; Mardis, Elaine R; Taylor, John W; McEwen, Juan G; Clay, Oliver K; Klein, Bruce S; Cuomo, Christina A

2015-10-01

Three closely related thermally dimorphic pathogens are causal agents of major fungal diseases affecting humans in the Americas: blastomycosis, histoplasmosis and paracoccidioidomycosis. Here we report the genome sequence and analysis of four strains of the etiological agent of blastomycosis, Blastomyces, and two species of the related genus Emmonsia, typically pathogens of small mammals. Compared to related species, Blastomyces genomes are highly expanded, with long, often sharply demarcated tracts of low GC-content sequence. These GC-poor isochore-like regions are enriched for gypsy elements, are variable in total size between isolates, and are least expanded in the avirulent B. dermatitidis strain ER-3 as compared with the virulent B. gilchristii strain SLH14081. The lack of similar regions in related species suggests these isochore-like regions originated recently in the ancestor of the Blastomyces lineage. While gene content is highly conserved between Blastomyces and related fungi, we identified changes in copy number of genes potentially involved in host interaction, including proteases and characterized antigens. In addition, we studied gene expression changes of B. dermatitidis during the interaction of the infectious yeast form with macrophages and in a mouse model. Both experiments highlight a strong antioxidant defense response in Blastomyces, and upregulation of dioxygenases in vivo suggests that dioxide produced by antioxidants may be further utilized for amino acid metabolism. We identify a number of functional categories upregulated exclusively in vivo, such as secreted proteins, zinc acquisition proteins, and cysteine and tryptophan metabolism, which may include critical virulence factors missed before in in vitro studies. Across the dimorphic fungi, loss of certain zinc acquisition genes and differences in amino acid metabolism suggest unique adaptations of Blastomyces to its host environment. These results reveal the dynamics of genome evolution

Structural and Pharmacological Effects of Ring-Closing Metathesis in Peptides

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Pål Rongved

2010-09-01

Full Text Available Applications of ring-closing alkene metathesis (RCM in acyclic α- and β-peptides and closely related systems are reviewed, with a special emphasis on the structural and pharmacological effects of cyclization by RCM.

Close-range photogrammetry for aircraft quality control

Science.gov (United States)

Schwartz, D. S.

Close range photogrammetry is applicable to quality assurance inspections, design data acquisition, and test management support tasks, yielding significant cost avoidance and increased productivity. An understanding of mensuration parameters and their related accuracies is fundamental to the successful application of industrial close range photogrammetry. Attention is presently given to these parameters and to the use of computer modelling as an aid to the photogrammetric entrepreneur in industry. Suggested improvements to cameras and film readers for industrial applications are discussed.

The γ-gliadin multigene family in common wheat (Triticum aestivum and its closely related species

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Chen Qing

2009-04-01

Full Text Available Abstract Background The unique properties of wheat flour primarily depend on gluten, which is the most important source of protein for human being. γ-Gliadins have been considered to be the most ancient of the wheat gluten family. The complex family structure of γ-gliadins complicates the determination of their function. Moreover, γ-gliadins contain several sets of celiac disease epitopes. However, no systematic research has been conducted yet. Results A total of 170 γ-gliadin genes were isolated from common wheat and its closely related species, among which 138 sequences are putatively functional. The ORF lengths of these sequences range from 678 to 1089 bp, and the repetitive region is mainly responsible for the size heterogeneity of γ-gliadins. The repeat motif P(Q/L/S/T/I/V/R/AF(S/Y/V/Q/I/C/LP(R/L/S/T/H/C/YQ1–2(P(S/L/T/A/F/HQQ1–2is repeated from 7 to 22 times. Sequence polymorphism and linkage disequilibrium analyses show that γ-gliadins are highly diverse. Phylogenic analyses indicate that there is no obvious discrimination between Sitopsis and Ae. tauschii at the Gli-1 loci, compared with diploid wheat. According to the number and placement of cysteine residues, we defined nine cysteine patterns and 17 subgroups. Alternatively, we classified γ-gliadins into two types based on the length of repetitive domain. Amino acid composition analyses indicate that there is a wide range of essential amino acids in γ-gliadins, and those γ-gliadins from subgroup SG-10 and SG-12 and γ-gliadins with a short repetitive domain are more nutritional. A screening of toxic epitopes shows that γ-gliadins with a pattern of C9 and γ-gliadins with a short repetitive domain almost lack any epitopes. Conclusion γ-Gliadin sequences in wheat and closely related Aegilops species are diverse. Each group/subgroup contributes differently to nutritional quality and epitope content. It is suggested that the genes with a short repetitive domain are more

Generalized modal analysis for closed-loop piezoelectric devices

International Nuclear Information System (INIS)

Giraud-Audine, Christophe; Giraud, Frédéric; Amberg, Michel; Lemaire-Semail, Betty

2015-01-01

Stress in a piezoelectric material can be controlled by imposing an electrical field. Thanks to feedback, this electrical field can be a function of some strain-related measurement so as to confer on the piezoelectric device a closed-loop macroscopic behaviour. In this paper we address the modelling of such a system by extending the modal decomposition methods to account for the closed loop. To do so, the boundary conditions are modified to include the electrical feedback circuit, hence allowing a closed-loop modal analysis. A case study is used to illustrate the theory and to validate it. The main advantage of the method is that design issues such as the coupling factor of the device and closed-loop stability are simultaneously captured. (paper)

Molecular study on the carAB operon reveals that carB gene is required for swimming and biofilm formation in Xanthomonas citri subsp. citri.

Science.gov (United States)

Zhuo, Tao; Rou, Wei; Song, Xue; Guo, Jing; Fan, Xiaojing; Kamau, Gicharu Gibson; Zou, Huasong

2015-10-23

The carA and carB genes code the small and large subunits of carbamoyl-phosphate synthase (CPS) that responsible for arginine and pyrimidine production. The purpose of this work was to study the gene organization and expression pattern of carAB operon, and the biological functions of carA and carB genes in Xanthomonas citri subsp. citri. RT-PCR method was employed to identify the full length of carAB operon transcript in X. citri subsp. citri. The promoter of carAB operon was predicted and analyzed its activity by fusing a GUS reporter gene. The swimming motility was tested on 0.25% agar NY plates with 1% glucose. Biofilm was measured by cell adhesion to polyvinyl chloride 96-well plate. The results indicated that carAB operon was composed of five gene members carA-orf-carB-greA-rpfE. A single promoter was predicted from the nucleotide sequence upstream of carAB operon, and its sensitivity to glutamic acid, uracil and arginine was confirmed by fusing a GUS reporter gene. Deletion mutagenesis of carB gene resulted in reduced abilities in swimming on soft solid media and in forming biofilm on polystyrene microtiter plates. From these results, we concluded that carAB operon was involved in multiple biological processes in X. citri subsp. citri.

An operon for production of bioactive gibberellin A4 phytohormone with wide distribution in the bacterial rice leaf streak pathogen Xanthomonas oryzae pv. oryzicola.

Science.gov (United States)

Nagel, Raimund; Turrini, Paula C G; Nett, Ryan S; Leach, Jan E; Verdier, Valérie; Van Sluys, Marie-Anne; Peters, Reuben J

2017-05-01

Phytopathogens have developed elaborate mechanisms to attenuate the defense response of their host plants, including convergent evolution of complex pathways for production of the GA phytohormones, which were actually first isolated from the rice fungal pathogen Gibberella fujikuroi. The rice bacterial pathogen Xanthomonas oryzae pv. oryzicola (Xoc) has been demonstrated to contain a biosynthetic operon with cyclases capable of producing the universal GA precursor ent-kaurene. Genetic (knock-out) studies indicate that the derived diterpenoid serves as a virulence factor for this rice leaf streak pathogen, serving to reduce the jasmonic acid-mediated defense response. Here the functions of the remaining genes in the Xoc operon are elucidated and the distribution of the operon in X. oryzae is investigated in over 100 isolates. The Xoc operon leads to production of the bioactive GA 4 , an additional step beyond production of the penultimate precursor GA 9 mediated by the homologous operons recently characterized from rhizobia. Moreover, this GA biosynthetic operon was found to be widespread in Xoc (> 90%), but absent in the other major X. oryzae pathovar. These results indicate selective pressure for production of GA 4 in the distinct lifestyle of Xoc, and the importance of GA to both fungal and bacterial pathogens of rice. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

The Xanthomonas campestris type III effector XopJ targets the host cell proteasome to suppress salicylic-acid mediated plant defence.

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Suayib Üstün

Full Text Available The phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria (Xcv requires type III effector proteins (T3Es for virulence. After translocation into the host cell, T3Es are thought to interact with components of host immunity to suppress defence responses. XopJ is a T3E protein from Xcv that interferes with plant immune responses; however, its host cellular target is unknown. Here we show that XopJ interacts with the proteasomal subunit RPT6 in yeast and in planta to inhibit proteasome activity. A C235A mutation within the catalytic triad of XopJ as well as a G2A exchange within the N-terminal myristoylation motif abolishes the ability of XopJ to inhibit the proteasome. Xcv ΔxopJ mutants are impaired in growth and display accelerated symptom development including tissue necrosis on susceptible pepper leaves. Application of the proteasome inhibitor MG132 restored the ability of the Xcv ΔxopJ to attenuate the development of leaf necrosis. The XopJ dependent delay of tissue degeneration correlates with reduced levels of salicylic acid (SA and changes in defence- and senescence-associated gene expression. Necrosis upon infection with Xcv ΔxopJ was greatly reduced in pepper plants with reduced expression of NPR1, a central regulator of SA responses, demonstrating the involvement of SA-signalling in the development of XopJ dependent phenotypes. Our results suggest that XopJ-mediated inhibition of the proteasome interferes with SA-dependent defence response to attenuate onset of necrosis and to alter host transcription. A central role of the proteasome in plant defence is discussed.

Mutations and/or close relatives? Six case work examples where 49 autosomal SNPs were used as supplementary markers

DEFF Research Database (Denmark)

Børsting, Claus; Morling, Niels

2011-01-01

ID multiplex assay. The six cases included two duos, two trios and two cases, where the alleged father was not available for testing and one or two of his close relatives were tested instead. The SNP investigation was more informative than the STR investigation in all six cases. In two cases, the alleged...... father would have been falsely included based on the STR results, while the SNP results showed that the alleged father was not the true parent. These case work examples underline the importance of performing supplementary investigations in selected cases and demonstrate the usefulness of the SNPfor...

Active fault diagnosis in closed-loop uncertain systems

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2006-01-01

Fault diagnosis of parametric faults in closed-loop uncertain systems by using an auxiliary input vector is considered in this paper, i.e. active fault diagnosis (AFD). The active fault diagnosis is based directly on the socalled fault signature matrix, related to the YJBK (Youla, Jabr, Bongiorno...... and Kucera) parameterization. Conditions are given for exact detection and isolation of parametric faults in closed-loop uncertain systems....

On the efficient determination of most near neighbors horseshoes, hand grenades, web search and other situations when close is close enough

CERN Document Server

Manasse, Mark S

2012-01-01

The time-worn aphorism ""close only counts in horseshoes and hand-grenades"" is clearly inadequate. Close also counts in golf, shuffleboard, archery, darts, curling, and other games of accuracy in which hitting the precise center of the target isn't to be expected every time, or in which we can expect to be driven from the target by skilled opponents. This lecture is not devoted to sports discussions, but to efficient algorithms for determining pairs of closely related web pages -- and a few other situations in which we have found that inexact matching is good enough; where proximity suffices.

Conserved PCR primer set designing for closely-related species to complete mitochondrial genome sequencing using a sliding window-based PSO algorithm.

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Cheng-Hong Yang

Full Text Available BACKGROUND: Complete mitochondrial (mt genome sequencing is becoming increasingly common for phylogenetic reconstruction and as a model for genome evolution. For long template sequencing, i.e., like the entire mtDNA, it is essential to design primers for Polymerase Chain Reaction (PCR amplicons which are partly overlapping each other. The presented chromosome walking strategy provides the overlapping design to solve the problem for unreliable sequencing data at the 5' end and provides the effective sequencing. However, current algorithms and tools are mostly focused on the primer design for a local region in the genomic sequence. Accordingly, it is still challenging to provide the primer sets for the entire mtDNA. METHODOLOGY/PRINCIPAL FINDINGS: The purpose of this study is to develop an integrated primer design algorithm for entire mt genome in general, and for the common primer sets for closely-related species in particular. We introduce ClustalW to generate the multiple sequence alignment needed to find the conserved sequences in closely-related species. These conserved sequences are suitable for designing the common primers for the entire mtDNA. Using a heuristic algorithm particle swarm optimization (PSO, all the designed primers were computationally validated to fit the common primer design constraints, such as the melting temperature, primer length and GC content, PCR product length, secondary structure, specificity, and terminal limitation. The overlap requirement for PCR amplicons in the entire mtDNA is satisfied by defining the overlapping region with the sliding window technology. Finally, primer sets were designed within the overlapping region. The primer sets for the entire mtDNA sequences were successfully demonstrated in the example of two closely-related fish species. The pseudo code for the primer design algorithm is provided. CONCLUSIONS/SIGNIFICANCE: In conclusion, it can be said that our proposed sliding window-based PSO

Genome-wide Identification and Expression Analysis of Calcium-dependent Protein Kinase and Its Closely Related Kinase Genes in Capsicum annuum

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hanyang ecai

2015-09-01

Full Text Available As Ca2+ sensors and effectors, calcium-dependent protein kinases (CDPKs play important roles in regulating the downstream components of calcium signaling, which are ubiquitously involved in plant growth, development, and response to environmental cues. However, no CDPKs have been characterized in Capsicum annuum thus far. Herein, a comprehensive analysis of genes encoding pepper CDPKs and CDPK-related protein kinases (CRKs was performed, and 31 CDPK genes and five closely related kinase genes were identified, which were phylogenetically divided into four distinct subfamilies and unevenly distributed across nine chromosomes. Conserved sequence and exon-intron structures were found to be shared by pepper CDPKs within the same subfamily, and the expansion of the CaCPK family in pepper was found to be due to segmental duplication events. Five CDPKs in the Capsicum annuum variety CM334 were found to be mutated in the Chiltepin variety, and one CDPK present in CM334 was lost in Chiltepin. The majority of CDPK and CRK genes were expressed in different pepper tissues and developmental stages, and 10, 12, and eight CDPK genes were transcriptionally modified by salt, heat, and Ralstonia solanacearum stresses, respectively. Furthermore, these genes were found to respond specifically to one stress as well as respond synergistically to two stresses or three stresses, suggesting that these CDPK genes might be involved in the specific or synergistic response of pepper to salt, heat, and R. solanacearum. Our results lay the foundation for future functional characterization of pepper CDPK and its closely related gene families.

Study on closed cycle MHD generation systems; Closed cycle MHD hatsuden system no kento

Energy Technology Data Exchange (ETDEWEB)

NONE

1988-03-01

The closed cycle noble gas MHD generation systems are surveyed and studied. The concept of closed cycle noble gas MHD generation is confirmed to extract high enthalpy, and now going into the engineering demonstration stage from the basic research stage. These systems have various characteristics. The highest working temperature is around 1,700 degrees C, which is close to that associated with the existing techniques. Use of helium or argon gas as the working fluid makes the system relatively free of various problems, e.g., corrosion. It can attain a much higher efficiency than the combined cycle involving gas turbine. It suffers less heat loss in the passages, is suitable for small- to medium-capacity power generation systems, and copes with varying load. The compact power generation passages decrease required size of the superconducting magnet. The technical problems to be solved include optimization of power generation conditions, demonstration of durability of the power generation passages, injection/recovery of the seed material, treatment of the working gas to remove molecular impurities, and development of heat exchangers serviceable at high temperature produced by direct combustion of coal. The conceptual designs of the triple combined system are completed. (NEDO)

Closing the loop.

Science.gov (United States)

Dassau, E; Atlas, E; Phillip, M

2010-02-01

The dream of closing the loop is actually the dream of creating an artificial pancreas and freeing the patients from being involved with the care of their own diabetes. Insulin-dependent diabetes (type 1) is a chronic incurable disease which requires constant therapy without the possibility of any 'holidays' or insulin-free days. It means that patients have to inject insulin every day of their life, several times per day, and in order to do it safely they also have to measure their blood glucose levels several times per day. Patients need to plan their meals, their physical activities and their insulin regime - there is only very small room for spontaneous activities. This is why the desire for an artificial pancreas is so strong despite the fact that it will not cure the diabetic patients. Attempts to develop a closed-loop system started in the 1960s but never got to a clinical practical stage of development. In recent years the availability of continuous glucose sensors revived those efforts and stimulated the clinician and researchers to believe that closing the loop might be possible nowadays. Many papers have been published over the years describing several different ideas on how to close the loop. Most of the suggested systems have a sensing arm that measures the blood glucose repeatedly or continuously, an insulin delivery arm that injects insulin upon command and a computer that makes the decisions of when and how much insulin to deliver. The differences between the various published systems in the literature are mainly in their control algorithms. However, there are also differences related to the method and site of glucose measurement and insulin delivery. SC glucose measurements and insulin delivery are the most studied option but other combinations of insulin measurements and glucose delivery including intravascular and intraperitoneal (IP) are explored. We tried to select recent publications that we believe had influenced and inspired people interested

A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

Directory of Open Access Journals (Sweden)

Ottado Jorgelina

2010-03-01

Full Text Available Abstract Background Plant natriuretic peptides (PNPs belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival. Results Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 α subunit, maturase K, and α- and β-tubulin. Conclusions We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence.

Attention to affective pictures in closed head injury: event-related brain potentials and cardiac responses.

Science.gov (United States)

Solbakk, Anne-Kristin; Reinvang, Ivar; Svebak, Sven; Nielsen, Christopher S; Sundet, Kjetil

2005-02-01

We examined whether closed head injury patients show altered patterns of selective attention to stimulus categories that naturally evoke differential responses in healthy people. Self-reported rating and electrophysiological (event-related potentials [ERPs], heart rate [HR]) responses to affective pictures were studied in patients with mild head injury (n = 20; CT/MRI negative), in patients with predominantly frontal brain lesions (n = 12; CT/MRI confirmed), and in healthy controls (n = 20). Affective valence similarly modulated HR and ERP responses in all groups, but group differences occurred that were independent of picture valence. The attenuation of P3-slow wave amplitudes in the mild head injury group indicates a reduction in the engagement of attentional resources to the task. In contrast, the general enhancement of ERP amplitudes at occipital sites in the group with primarily frontal brain injury may reflect disinhibition of input at sensory receptive areas, possibly due to a deficit in top-down modulation performed by anterior control systems.

Closed forms and multi-moment maps

DEFF Research Database (Denmark)

Madsen, Thomas Bruun; Swann, Andrew Francis

2013-01-01

We extend the notion of multi-moment map to geometries defined by closed forms of arbitrary degree. We give fundamental existence and uniqueness results and discuss a number of essential examples, including geometries related to special holonomy. For forms of degree four, multi-moment maps are gu...

Relation between premorbid adjustment, duration of untreated psychosis and close interpersonal trauma in first-episode psychosis

DEFF Research Database (Denmark)

Haahr, Ulrik Helt; Larsen, Tor Ketil; Simonsen, Erik

2018-01-01

Trauma Survey at their 5 years follow-up interview. RESULTS: Half of the patients reported that they had experienced interpersonal trauma and one-third reported having experienced close interpersonal trauma before the age of 18. Women reported more sexual abuse, physical attacks and emotional...... different types of trauma, in particular close interpersonal traumas experienced before the age of 18, premorbid factors and baseline clinical characteristics in a sample of first-episode psychosis patients. METHODS: A total of 191 patients from the 'TIPS' cohort completed assessment with the Brief Betrayal...... and physical maltreatment than men. There were significant associations between early interpersonal trauma and premorbid adjustment and duration of untreated psychosis, but no significant associations with length of education, comorbid substance use or baseline clinical symptomatology. CONCLUSIONS: Close...

NCBI nr-aa BLAST: CBRC-TNIG-22-0185 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TNIG-22-0185 ref|YP_451103.1| manganese transport protein [Xanthomonas oryzae ...pv. oryzae MAFF 311018] dbj|BAE68829.1| manganese transport protein [Xanthomonas oryzae pv. oryzae MAFF 311018] YP_451103.1 0.030 28% ...

Frost related dieback in Estonian energy plantations of willows in relation to fertilisation and pathogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Cambours, M.A.; Nejad, P. [Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, Box 7026, 750 07 Uppsala (Sweden); Heinsoo, K. [Institute of Zoology and Botany, Estonian Agricultural University, Riia 181, 51014 Tartu (Estonia); Granhall, U. [Department of Microbiology, Swedish University of Agricultural Sciences, Box 7025, 750 07 Uppsala (Sweden)

2006-03-15

Two 9-year old Estonian Salix plantations suffering from dieback were studied: one situated on poor mineral soil and divided into fertilised and unfertilised plots (Saare plantation) and another growing on a well-decomposed and nitrogen-rich organic soil, without fertiliser application (Kambja plantation). Bacteria from internal tissues of visually damaged shoots from seven clones were isolated in spring and autumn. The strains were subsequently biochemically characterised and tested for ice nucleation activity and pathogenicity on Salix. Some strains were also analysed with 16S rRNA. High numbers of culturable bacteria were found, belonging mainly to Erwinia, Sphingomonas, Pseudomonas and Xanthomonas spp. Fertilised plots were significantly more colonised by bacteria than unfertilised plots and also more extensively damaged, showing a lower density of living plants after 7 years of culture. More ice nucleation active (INA) strains were found in Saare fertilised plots and at Kambja than in Saare unfertilised plots. Likewise, most pathogenic strains were isolated from Saare fertilised plots and from Kambja. For some of the willow clones studied, dieback appeared to be related to both clonal frost sensitivity and abundance of INA and pathogenic bacteria. The plantations probably suffered from the presence of high amounts of pathogens and from frost related injuries aggravated by INA bacteria. Most probably the fertilisation at Saare and the nitrogen-rich soil at Kambja created a favourable environment for bacterial development and led to high dieback levels after the first harvest. (author)

Experimental simulation of closed timelike curves.

Science.gov (United States)

Ringbauer, Martin; Broome, Matthew A; Myers, Casey R; White, Andrew G; Ralph, Timothy C

2014-06-19

Closed timelike curves are among the most controversial features of modern physics. As legitimate solutions to Einstein's field equations, they allow for time travel, which instinctively seems paradoxical. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. The study of these systems therefore provides valuable insight into nonlinearities and the emergence of causal structures in quantum mechanics--essential for any formulation of a quantum theory of gravity. Here we experimentally simulate the nonlinear behaviour of a qubit interacting unitarily with an older version of itself, addressing some of the fascinating effects that arise in systems traversing a closed timelike curve. These include perfect discrimination of non-orthogonal states and, most intriguingly, the ability to distinguish nominally equivalent ways of preparing pure quantum states. Finally, we examine the dependence of these effects on the initial qubit state, the form of the unitary interaction and the influence of decoherence.

22 CFR 708.6 - Records of closed meetings.

Science.gov (United States)

2010-04-01

... days from the date of receipt of the request for review (excluding Saturdays, Sundays, and legal public... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Records of closed meetings. 708.6 Section 708.6 Foreign Relations OVERSEAS PRIVATE INVESTMENT CORPORATION ADMINISTRATIVE PROVISIONS SUNSHINE REGULATIONS...

Eyes-Closed Single-Limb Balance is Not Related to Hypermobility Status in Dancers.

Science.gov (United States)

Marulli, Tiffany A; Harmon-Matthews, Lindsay E; Davis-Coen, J Hope; Willigenburg, Nienke W; Hewett, Timothy E

2017-06-15

Hypermobility may be associated with decreased lower extremity proprioception, which in turn may increase injury risk. The prevalence of hypermobility in dancers varies across studies, but joint hypermobility appears to be more common in dancers than in the general population. The purpose of this study was to determine how hypermobility affects eyes-closed single-limb balance as an indirect measure of proprioception in dancers. The secondary aim was to compare hypermobility and balance across dancer affiliation groups. Data were collected from 45 professional dancers, 11 collegiate modern dancers, 227 student dancers, and 15 pre-professional dancers during routine dance screens. Dancer hypermobility status was assessed via an eight-point Beighton-Horan Laxity test. Single-limb balance time, in seconds, was assessed in parallel position with the eyes closed. Hypermobile (HM) and non-hypermobile (NHM) dancers showed very similar balance times (HM median: 36.5 seconds; NHM median: 33.0 seconds; p = 0.982). Hypermobility was not significantly different between dancer affiliation groups (p = 0.154): 47% in ballet academy students, 27% in collegiate modern dancers, 62% in pre-professional dancers, and 36% in professional dancers. The student, pre-professional, and professional ballet dancers all demonstrated longer balance times than the collegiate modern dancers; however, this difference was only significant between the professional ballet dancers and collegiate modern dancers (p = 0.026). Dancers demonstrated a higher prevalence of hypermobility than what has been reported for the general population. Joint hypermobility did not affect eyes-closed single-limb balance time. Future studies are needed to determine if joint hypermobility affects more sensitive measures of proprioception and risk of injury.

[Analysis of literature citations in original articles published in Spanish and international nursing journals and journals in 2 closely related disciplines].

Science.gov (United States)

Muñoz-Soler, Verónica; Flores-López, María José; Cabañero-Martínez, María José; Richart-Martínez, Miguel

2007-01-01

To compare Spanish nursing journals with 2 English-language standard journals, as well as Spanish journals in closely related disciplines, to identify possible quantitative and qualitative shortcomings in scientific documentation. We performed a descriptive, cross-sectional study of the references contained in 796 articles from 6 Spanish journals from 3 health disciplines (2000-2002) and 2 English-language nursing journals (2000-2001). The number of references, type of publication cited, and language of the document cited were compared in individual journals, and in journals grouped by discipline and according to language. Spanish-language nursing journals had the lowest mean number of references per article (X- = 16.20) when compared with psychology journals (X- = 31.24), medical journals (X- = 31.39) and international nursing journals (X- = 37.11). Among Spanish journals, citation of English-language publications was most frequent in medical journals (X- = 26.28) and least frequent in nursing journals (X- = 6.04). In contrast, citation of Spanish documents was most frequent in nursing journals (X- = 9.79) and least frequent in medical journals (X- = 4.43). Although scientific publication of Spanish nursing has improved, it is not comparable to publication of closely related disciplines and international nursing. The low citation of English documents clearly reveals the risk of scientific insularity.

Sensibilidade a cobre, estreptomicina e oxitetraciclina em Xanthomonas spp. associadas à mancha-bacteriana do tomate para processamento industrial

Directory of Open Access Journals (Sweden)

Quezado-Duval Alice Maria

2003-01-01

Full Text Available Apesar de amplamente empregados em lavouras de tomate para processamento industrial no Brasil, fungicidas cúpricos e antibióticos registrados para uso agrícola nem sempre resultam em controle eficiente das bacterioses que afetam a cultura. O aparecimento de estirpes resistentes é uma das causas dessa baixa eficiência. Avaliou-se, in vitro, a sensibilidade a cobre, estreptomicina e oxitetraciclina de 389 isolados de Xanthomonas spp. associadas à mancha-bacteriana do tomateiro, sendo 92 de X. axonopodis pv. vesicatoria (60 do grupo "A"/raça T1 e 32 do "C"/raça T3, 93 de X. vesicatoria (grupo "B"/raça T2 e 204 de X. gardneri (grupo "D"/raça T2. Os isolados foram obtidos de plantas doentes em campos comerciais de tomate para processamento industrial nos estados de Goiás, Minas Gerais, Pernambuco e Bahia, nos anos de 1995 a 1998 e em 2000. Alíquotas de 5 ml de suspensões bacterianas foram depositadas em meio Nutriente-Ágar suplementado com sulfato de cobre, nas concentrações de 50 e 200 µg/ml; sulfato de estreptomicina, a 25 e 200 µg/ml e cloridrato de oxitetraciclina, a 25 µg/ml. Nenhum isolado foi resistente a oxitetraciclina, como também nenhum foi resistente ao cobre na concentração de 200 µg/ml do sulfato de cobre. No entanto, houve diferença entre isolados quanto à sensibilidade ao sulfato de cobre na concentração de 50 µg/ml e ao sulfato de estreptomicina nas duas concentrações empregadas. As freqüências de isolados de X. gardneri, X. axonopodis pv. vesicatoria (grupos "A" e "C" e X. vesicatoria resistentes à estreptomicina (25 µg/ml do produto usado foram, respectivamente, 98%, 38% e 2%, ao passo que, ao cobre, foram, respectivamente, 48%, 4% e 74%. Todos os isolados do grupo "C" foram sensíveis à estreptomicina e 97% sensíveis ao cobre.

Transcriptome sequencing of Crucihimalaya himalaica (Brassicaceae) reveals how Arabidopsis close relative adapt to the Qinghai-Tibet Plateau

Science.gov (United States)

Qiao, Qin; Wang, Qia; Han, Xi; Guan, Yanlong; Sun, Hang; Zhong, Yang; Huang, Jinling; Zhang, Ticao

2016-02-01

The extreme environment of the Qinghai-Tibet Plateau (QTP) provides an ideal natural laboratory for studies on adaptive evolution. Few genome/transcriptome based studies have been conducted on how plants adapt to the environments of QTP compared to numerous studies on vertebrates. Crucihimalaya himalaica is a close relative of Arabidopsis with typical QTP distribution, and is hoped to be a new model system to study speciation and ecological adaptation in extreme environment. In this study, we de novo generated a transcriptome sequence of C. himalaica, with a total of 49,438 unigenes. Compared to five relatives, 10,487 orthogroups were shared by all six species, and 4,286 orthogroups contain putative single copy gene. Further analysis identified 487 extremely significantly positively selected genes (PSGs) in C. himalaica transcriptome. Theses PSGs were enriched in functions related to specific adaptation traits, such as response to radiation, DNA repair, nitrogen metabolism, and stabilization of membrane. These functions are responsible for the adaptation of C. himalaica to the high radiation, soil depletion and low temperature environments on QTP. Our findings indicate that C. himalaica has evolved complex strategies for adapting to the extreme environments on QTP and provide novel insights into genetic mechanisms of highland adaptation in plants.

Niche segregation in two closely related species of stickleback along a physiological axis: explaining multidecadel changes in fish distribution from iron-induced respiratory impairment

NARCIS (Netherlands)

Verberk, W.C.E.P.; Munckhof, van den P.J.J.; Pollux, B.J.A.

2012-01-01

Acute exposure to iron can be lethal to fish, but long-term sublethal impacts of iron require further study. Here we investigated whether the spatial and temporal distribution (1967–2004) of two closely related species of stickleback matched the spatial distribution of iron concentrations in the

Are the metabolomic responses to folivory of closely related plant species linked to macroevolutionary and plant-folivore coevolutionary processes?

Energy Technology Data Exchange (ETDEWEB)

Rivas-Ubach, Albert [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington 99354 USA; CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; Hódar, José A. [Grupo de Ecología Terrestre, Departamento de Biología Animal y Ecología, Facultad de Ciencias, Universidad de Granada, 18071 Granada Spain; Sardans, Jordi [CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; CSIC, Global Ecology Unit CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès 08913 Catalonia Spain; Kyle, Jennifer E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland Washington 99354 USA; Kim, Young-Mo [Biological Sciences Division, Pacific Northwest National Laboratory, Richland Washington 99354 USA; Oravec, Michal [Global Change Research Centre, Academy of Sciences of the Czech Republic, Bĕlidla 4a CZ-603 00 Brno Czech Republic; Urban, Otmar [Global Change Research Centre, Academy of Sciences of the Czech Republic, Bĕlidla 4a CZ-603 00 Brno Czech Republic; Guenther, Alex [Department of Earth System Science, University of California, Irvine California 92697 USA; Peñuelas, Josep [CREAF, Cerdanyola del Vallès 08913 Catalonia Spain; CSIC, Global Ecology Unit CREAF-CEAB-CSIC-UAB, Cerdanyola del Vallès 08913 Catalonia Spain

2016-06-02

The debate whether the coevolution of plants and insects or macroevolutionary processes (phylogeny) is the main driver determining the arsenal of molecular defensive compounds of plants remains unresolved. Attacks by herbivorous insects affect not only the composition of defensive compounds in plants but the entire metabolome (the set of molecular metabolites), including defensive compounds. Metabolomes are the final products of genotypes and are directly affected by macroevolutionary processes, so closely related species should have similar metabolomic compositions and may respond in similar ways to attacks by folivores. We analyzed the elemental compositions and metabolomes of needles from Pinus pinaster, P. nigra and P. sylvestris to determine if these closely related Pinus species with different coevolutionary histories with the caterpillars of the processionary moth respond similarly to attacks by this lepidopteran. All pines had different metabolomes and metabolic responses to herbivorous attack. The metabolomic variation among the pine species and the responses to folivory reflected their macroevolutionary relationships, with P. pinaster having the most divergent metabolome. The concentrations of phenolic metabolites were generally not higher in the attacked trees, which had lower concentrations of terpenes, suggesting that herbivores avoid individuals with high concentrations of terpenes. Our results suggest that macroevolutionary history plays important roles in the metabolomic responses of these pine species to folivory, but plant-insect coevolution probably constrains those responses. Combinations of different evolutionary factors and trade-offs are likely responsible for the different responses of each species to folivory, which is not necessarily exclusively linked to plant-insect coevolution.

Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution.

Directory of Open Access Journals (Sweden)

Jonathan eFilée

2015-06-01

Full Text Available Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales. Origin and evolution of these Giant Viruses (GVs remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for 5 groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no trend of genome expansion or general tendency of genome contraction. Instead, GV genomes accumulated genomic mutations over the time with gene gains compensating the different losses. In addition, each lineage displays specific patterns of genome evolution. Mimiviridae (megaviruses and mimiviruses and Chlorella Phycodnaviruses evolved mainly by duplications and losses of genes belonging to large paralogous families (including movements of diverse mobiles genetic elements, whereas Micromonas and Ostreococcus Phycodnaviruses derive most of their genetic novelties thought lateral gene transfers. Taken together, these data support an accordion-like model of evolution in which GV genomes have undergone successive steps of gene gain and gene loss, accrediting the hypothesis that genome gigantism appears early, before the diversification of the different GV lineages.

Genomic comparison of closely related Giant Viruses supports an accordion-like model of evolution.

Science.gov (United States)

Filée, Jonathan

2015-01-01

Genome gigantism occurs so far in Phycodnaviridae and Mimiviridae (order Megavirales). Origin and evolution of these Giant Viruses (GVs) remain open questions. Interestingly, availability of a collection of closely related GV genomes enabling genomic comparisons offer the opportunity to better understand the different evolutionary forces acting on these genomes. Whole genome alignment for five groups of viruses belonging to the Mimiviridae and Phycodnaviridae families show that there is no trend of genome expansion or general tendency of genome contraction. Instead, GV genomes accumulated genomic mutations over the time with gene gains compensating the different losses. In addition, each lineage displays specific patterns of genome evolution. Mimiviridae (megaviruses and mimiviruses) and Chlorella Phycodnaviruses evolved mainly by duplications and losses of genes belonging to large paralogous families (including movements of diverse mobiles genetic elements), whereas Micromonas and Ostreococcus Phycodnaviruses derive most of their genetic novelties thought lateral gene transfers. Taken together, these data support an accordion-like model of evolution in which GV genomes have undergone successive steps of gene gain and gene loss, accrediting the hypothesis that genome gigantism appears early, before the diversification of the different GV lineages.

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

Directory of Open Access Journals (Sweden)

Lavanya Tayi

Full Text Available Xanthomonas oryzae pv.oryzae (Xoo causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA, one pectin methyl esterase (pmt and two pectate lyases (pel and pelL. There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43 grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA. Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43 in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

Efeito do tratamento de bacelos de videira 'Red Globe' no controle do cancro bacteriano causado por Xanthomonas campestris pv. viticola

Directory of Open Access Journals (Sweden)

Carine Rosa Naue

2014-12-01

Full Text Available A disseminação de Xanthomonas campestris pv. viticola (Xcv, agente do cancro bacteriano da videira, ocorre, dentre outras formas, por meio de mudas e bacelos infectados. Foi estudada a obtenção de material propagativo livre do patógeno, testando a eficiência do tratamento de bacelos com termoterapia, bactericidas e sanitizantes. Os isolados de Xcv foram testados quanto à patogenicidade e realizado o teste de sensibilidade in vitro aos produtos, em diferentes concentrações. A erradicação de Xcv em bacelos de videira foi testada em experimentos com termoterapia (50ºC por 30 e 40 min; 53ºC por 5 e 10 min; bactericidas [oxitetraciclina+sulfato de cobre (150+2.000; 165+2.200; 180+2.400 e 195+2.600 mg L-1 de H2O e oxitetraciclina (600; 700; 800 e 900 mg L-1]; e sanitizantes [cloreto de dodecildimetil amônio (600; 1.200; 1.800; 2.400 e 3.000 µL L-1; hipoclorito de sódio (5.000; 10.000; 20.000; 30.000 e 40.000 µL L-1 e cloreto de benzalcônio (125; 167;250; 334 e 500 µL L-1]. Foram avaliados período de incubação, incidência e severidade da doença. O bactericida oxitetraciclina e os sanitizantes cloreto de dodecildimetil amônio e hipoclorito de sódio proporcionaram os maiores halos de inibição de Xcv in vitro. No entanto, apesar dos diversos tratamentos testados, não foi possível recomendar tratamento termoterápico ou produto que erradicasse Xcv de bacelos infectados. Porém, ficou confirmada a grande importância destes na disseminação do agente do cancro bacteriano da videira.

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

Science.gov (United States)

Tayi, Lavanya; Maku, Roshan V; Patel, Hitendra Kumar; Sonti, Ramesh V

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG) degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA), one pectin methyl esterase (pmt) and two pectate lyases (pel and pelL). There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43) grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA). Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43) in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

NCBI nr-aa BLAST: CBRC-PMAR-01-0384 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PMAR-01-0384 ref|YP_200844.1| putative manganese transport protein MntH [Xanth...omonas oryzae pv. oryzae KACC10331] gb|AAW75459.1| manganese transport protein [Xanthomonas oryzae pv. oryzae KACC10331] YP_200844.1 1.7 33% ...

NCBI nr-aa BLAST: CBRC-TNIG-22-0185 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-TNIG-22-0185 ref|YP_200844.1| putative manganese transport protein MntH [Xanth...omonas oryzae pv. oryzae KACC10331] gb|AAW75459.1| manganese transport protein [Xanthomonas oryzae pv. oryzae KACC10331] YP_200844.1 0.030 28% ...

Asteroseismic effects in close binary stars

Science.gov (United States)

Springer, Ofer M.; Shaviv, Nir J.

2013-09-01

Turbulent processes in the convective envelopes of the Sun and stars have been shown to be a source of internal acoustic excitations. In single stars, acoustic waves having frequencies below a certain cut-off frequency propagate nearly adiabatically and are effectively trapped below the photosphere where they are internally reflected. This reflection essentially occurs where the local wavelength becomes comparable to the pressure scale height. In close binary stars, the sound speed is a constant on equipotentials, while the pressure scale height, which depends on the local effective gravity, varies on equipotentials and may be much greater near the inner Lagrangian point (L1). As a result, waves reaching the vicinity of L1 may propagate unimpeded into low-density regions, where they tend to dissipate quickly due to non-linear and radiative effects. We study the three-dimensional propagation and enhanced damping of such waves inside a set of close binary stellar models using a WKB approximation of the acoustic field. We find that these waves can have much higher damping rates in close binaries, compared to their non-binary counterparts. We also find that the relative distribution of acoustic energy density at the visible surface of close binaries develops a ring-like feature at specific acoustic frequencies and binary separations.

Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study

Science.gov (United States)

Davies, Kimberley T. A.; Gentleman, W. C.; DiBacco, C.; Johnson, C. L.

2015-09-01

This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.

Xanthomonas oryzae pv. oryzae TALE proteins recruit OsTFIIAγ1 to compensate for the absence of OsTFIIAγ5 in bacterial blight in rice.

Science.gov (United States)

Ma, Wenxiu; Zou, Lifang; Ji, Zhiyuan; Xu, Xiameng; Xu, Zhengyin; Yang, Yangyang; Alfano, James R; Chen, Gongyou

2018-04-28

Xanthomonas oryzae pv. oryzae (Xoo), causal agent of bacterial blight (BB) of rice, uses transcription activator-like effectors (TALEs) to interact with the basal transcription factor gama subunit OsTFIIAγ5 (Xa5) and activates transcription of host genes. However, how OsTFIIAγ1, the other OsTFIIAγ protein, functions in the presence of TALEs remains unclear. In this study, we show that OsTFIIAγ1 plays a compensatory role in the absence of Xa5. The expression of OsTFIIAγ1, which is activated by TALE PthXo7, increased the expression of host genes targeted by avirulent and virulent TALEs. Defective OsTFIIAγ1 rice lines showed reduced expression of the TALE-targeted susceptibility (S) genes, OsSWEET11 and OsSWEET14, which resulted in increased BB resistance. Selected TALEs (PthXo1, AvrXa7, and AvrXa27) were evaluated for interactions with OsTFIIAγ1, Xa5 and xa5 (naturally-occurring mutant form of Xa5) using biomolecular fluorescence complementation (BiFC) and microscale thermophoresis (MST). BiFC and MST demonstrated that the three TALEs bind Xa5 and OsTFIIAγ1 with a stronger affinity than xa5. These results provide insight into the complex roles of OsTFIIAγ1 and OsTFIIAγ5 in TALE-mediated host gene transcription. This article is protected by copyright. All rights reserved. © 2018 BSPP and John Wiley & Sons Ltd.

Aspergillus waksmanii sp. nov. and Aspergillus marvanovae sp. nov., two closely related species in section Fumigati

DEFF Research Database (Denmark)

Hubka, Vit; Peterson, Stephen W.; Frisvad, Jens Christian

2013-01-01

Two new and phylogenetically closely related species in Aspergillus section Fumigati are described and illustrated. Homothallic Aspergillus waksmanii sp. nov. was isolated from New Jersey soil (USA) and is represented by the ex-type isolate NRRL 179T (=CCF 4266T=Thom 4138.HS2T=IBT 31900T......). Aspergillus marvanovae sp. nov. was isolated from water with high boracic acid anions content in Dukovany nuclear power station (Czech Republic). The sexual stage of this species is unknown, but the MAT1-1 locus was successfully amplified suggesting that the species is probably heterothallic and teleomorphic...... but is represented by only the ex-type isolate CCM 8003T (=CCF 4037T=NRRL 62486T=IBT 31279T=IFM 60873T). Both species can be distinguished from all previously described species in section Fumigati based on morphology, maximum growth temperature, sequence data from five unlinked loci and unique secondary metabolites...

extraction of high quality dna from polysaccharides-secreting ...

African Journals Online (AJOL)

cistvr

A DNA extraction method using CTAB was used for the isolation of genomic DNA from ten. Xanthomonas campestris pathovars, ten isolates of Xanthomonas albilineans and one isolate of. Pseudomonas rubrisubalbicans. High quality DNA was obtained that was ideal for molecular analy- ses. Extracellular polysaccharides ...

Report on {open_quotes}inspection of human subject research in intelligence and intelligence-related projects{close_quotes}

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-01-16

Executive Order 12333, {open_quotes}United States Intelligence Activities,{close_quotes} (1) designates the Department`s intelligence element as a member of the Intelligence Community, and (2) states that no agency within the Intelligence community shall sponsor, contract for or conduct research on human subjects except in accordance with guidelines issued by the Department of Health and Human Services. The Federal policy for the Protection of Human Subjects, which was based on Department of Health and Human Services regulations, was promulgated in Title 10 Code of Federal Regulations Part 745 by the Department of Energy. The purpose of this inspection was to review the internal control procedures used by the Office of Nonproliferation and National Security to manage selected intelligence and intelligence-related projects that involve human subject research.

A Suppressor of the Menadione-Hypersensitive Phenotype of a Xanthomonas campestris pv. phaseoli oxyR Mutant Reveals a Novel Mechanism of Toxicity and the Protective Role of Alkyl Hydroperoxide Reductase

Science.gov (United States)

Vattanaviboon, Paiboon; Whangsuk, Wirongrong; Mongkolsuk, Skorn

2003-01-01

We isolated menadione-resistant mutants of Xanthomonas campestris pv. phaseoli oxyR (oxyRXp). The oxyRR2Xp mutant was hyperresistant to the superoxide generators menadione and plumbagin and was moderately resistant to H2O2 and tert-butyl hydroperoxide. Analysis of enzymes involved in oxidative-stress protection in the oxyRR2Xp mutant revealed a >10-fold increase in AhpC and AhpF levels, while the levels of superoxide dismutase (SOD), catalase, and the organic hydroperoxide resistance protein (Ohr) were not significantly altered. Inactivation of ahpC in the oxyRR2Xp mutant resulted in increased sensitivity to menadione killing. Moreover, high levels of expression of cloned ahpC and ahpF in the oxyRXp mutant complemented the menadione hypersensitivity phenotype. High levels of other oxidant-scavenging enzymes such as catalase and SOD did not protect the cells from menadione toxicity. These data strongly suggest that the toxicity of superoxide generators could be mediated via organic peroxide production and that alkyl hydroperoxide reductase has an important novel function in the protection against the toxicity of these compounds in X. campestris. PMID:12591894

Structures of closed and open conformations of dimeric human ATM

Science.gov (United States)

Baretić, Domagoj; Pollard, Hannah K.; Fisher, David I.; Johnson, Christopher M.; Santhanam, Balaji; Truman, Caroline M.; Kouba, Tomas; Fersht, Alan R.; Phillips, Christopher; Williams, Roger L.

2017-01-01

ATM (ataxia-telangiectasia mutated) is a phosphatidylinositol 3-kinase–related protein kinase (PIKK) best known for its role in DNA damage response. ATM also functions in oxidative stress response, insulin signaling, and neurogenesis. Our electron cryomicroscopy (cryo-EM) suggests that human ATM is in a dynamic equilibrium between closed and open dimers. In the closed state, the PIKK regulatory domain blocks the peptide substrate–binding site, suggesting that this conformation may represent an inactive or basally active enzyme. The active site is held in this closed conformation by interaction with a long helical hairpin in the TRD3 (tetratricopeptide repeats domain 3) domain of the symmetry-related molecule. The open dimer has two protomers with only a limited contact interface, and it lacks the intermolecular interactions that block the peptide-binding site in the closed dimer. This suggests that the open conformation may be more active. The ATM structure shows the detailed topology of the regulator-interacting N-terminal helical solenoid. The ATM conformational dynamics shown by the structures represent an important step in understanding the enzyme regulation. PMID:28508083

A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

KAUST Repository

Garavaglia, Betiana S; Thomas, Ludivine; Zimaro, Tamara; Gottig, Natalia; Daurelio, Lucas D; Ndimba, Bongani; Orellano, Elena G; Ottado, Jorgelina; Gehring, Christoph A

2010-01-01

Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

A plant natriuretic peptide-like molecule of the pathogen Xanthomonas axonopodis pv. citri causes rapid changes in the proteome of its citrus host

KAUST Repository

Garavaglia, Betiana S

2010-03-21

Background: Plant natriuretic peptides (PNPs) belong to a novel class of peptidic signaling molecules that share some structural similarity to the N-terminal domain of expansins and affect physiological processes such as water and ion homeostasis at nano-molar concentrations. The citrus pathogen Xanthomonas axonopodis pv. citri possesses a PNP-like peptide (XacPNP) uniquely present in this bacteria. Previously we observed that the expression of XacPNP is induced upon infection and that lesions produced in leaves infected with a XacPNP deletion mutant were more necrotic and lead to earlier bacterial cell death, suggesting that the plant-like bacterial PNP enables the plant pathogen to modify host responses in order to create conditions favorable to its own survival.Results: Here we measured chlorophyll fluorescence parameters and water potential of citrus leaves infiltrated with recombinant purified XacPNP and demonstrate that the peptide improves the physiological conditions of the tissue. Importantly, the proteomic analysis revealed that these responses are mirrored by rapid changes in the host proteome that include the up-regulation of Rubisco activase, ATP synthase CF1 ? subunit, maturase K, and ?- and ?-tubulin.Conclusions: We demonstrate that XacPNP induces changes in host photosynthesis at the level of protein expression and in photosynthetic efficiency in particular. Our findings suggest that the biotrophic pathogen can use the plant-like hormone to modulate the host cellular environment and in particular host metabolism and that such modulations weaken host defence. 2010 Garavaglia et al; licensee BioMed Central Ltd.

Evaluation of Occupational Closed Globe Eye Injuries

Directory of Open Access Journals (Sweden)

Berna Akova-Budak

2016-01-01

Full Text Available Aim: To evaluate closed glob injuries related to occupational accidents of patients who had official occupational accident records. Material and Method: The medical records of patients with ocular injuries who referred to Department of Ophthalmology or emergency of Uludag University, School of Medicine between January 2010 and December 2013 with official occupational accident report were retrospectively reviewed. The patients with closed globe injuries following trauma were included. Age, sex, the injured eye, the cause of the trauma, whether the precautions were taken or not by the patient, the damage due to trauma were recorded. Results: According to the official records, 108 patients referred to our clinic with closed globe injury related to occupational accident. One hundred twenty eyes of 108 patients ( 2 females, 106 males were evaluated. The mean age of the patients was 33±8.6 years. The most frequent cause of injury was foreign bodies on the ocular surface followed by blunt trauma. The mean age of the patients injured with foreign bodies was found to be significantly lower than the patients injured with blunt objects (p=0.039. Thirteen patients reported that they had used preventive equipment. Discussion: It is of utmost importance that the awareness of the workers should be raised and they should be educated about the use of preventive equipment to prevent the occupational eye injuries. The education of particularly the younger patients about the occupational injuries when they begin to work may decrease the rate of occupational accident related eye injuries.

Closed depression topography and Harps soil, revisited

Science.gov (United States)

The Harps soil (Fine-loamy, mixed superactive, mesic Typic Calciaquoll) developed around wetland depressions. The purpose of this study is 1) to delineate surface deposition of carbonates representing Harps soil which results from outward and upward flow around closed depressions, and 2) to relate t...

Co-evolution in a landrace meta-population: two closely related pathogens interacting with the same host can lead to different adaptive outcomes.

Science.gov (United States)

Rau, Domenico; Rodriguez, Monica; Leonarda Murgia, Maria; Balmas, Virgilio; Bitocchi, Elena; Bellucci, Elisa; Nanni, Laura; Attene, Giovanna; Papa, Roberto

2015-08-07

We examined the local adaptation patterns in a system comprising several interconnected heterogeneous plant populations from which populations of two phylogenetically closely related pathogens were also sampled. The host is Hordeum vulgare (cultivated barley); the pathogens are Pyrenophora teres f. teres (net form) and Pyrenophora teres f. maculata (spot form), the causal agents of barley net blotch. We integrated two approaches, the comparison between the population structures of the host and the pathogens, and a cross-inoculation test. We demonstrated that two closely related pathogens with very similar niche specialisation and life-styles can give rise to different co-evolutionary outcomes on the same host. Indeed, we detected local adaptation for the net form of the pathogen but not for the spot form. We also provided evidence that an a-priori well-known resistance quantitative-trait-locus on barley chromosome 6H is involved in the co-evolutionary 'arms race' between the plant and the net-form pathogen. Moreover, data suggested latitudinal clines of host resistance and that different ecological conditions can result in differential selective pressures at different sites. Our data are of interest for on-farm conservation of plant genetic resources, as also in establishing efficient breeding programs and strategies for deployment of resistance genes of P. teres.

ORF Alignment: NC_006834 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available NC_006834 gi|58582167 >1iwlA 2 180 70 254 2e-49 ... ref|YP_201183.1| outer-membrane lipoproteins... ... outer-membrane lipoproteins carrier protein precursor ... [Xanthomonas oryzae pv. oryzae KAC... carrier protein precursor [Xanthomonas ... oryzae pv. oryzae KACC10331] gb|AAW75798.1| ...

Authentication of Closely Related Fish and Derived Fish Products Using Tandem Mass Spectrometry and Spectral Library Matching.

Science.gov (United States)

Nessen, Merel A; van der Zwaan, Dennis J; Grevers, Sander; Dalebout, Hans; Staats, Martijn; Kok, Esther; Palmblad, Magnus

2016-05-11

Proteomics methodology has seen increased application in food authentication, including tandem mass spectrometry of targeted species-specific peptides in raw, processed, or mixed food products. We have previously described an alternative principle that uses untargeted data acquisition and spectral library matching, essentially spectral counting, to compare and identify samples without the need for genomic sequence information in food species populations. Here, we present an interlaboratory comparison demonstrating how a method based on this principle performs in a realistic context. We also increasingly challenge the method by using data from different types of mass spectrometers, by trying to distinguish closely related and commercially important flatfish, and by analyzing heavily contaminated samples. The method was found to be robust in different laboratories, and 94-97% of the analyzed samples were correctly identified, including all processed and contaminated samples.

Leave for illness/accident or in the event of illness of a close relative - New medical certificate templates

CERN Multimedia

HR department

2016-01-01

Medical certificate templates are now available in the Admin e-guide (follow the “Forms and templates” link):    Medical certificate for illness/accident Medical certificate for a medical examination or treatment Medical certificate in the event of illness of a close relative These templates are provided for the convenience of members of the personnel and their use is recommended but not compulsory. Other forms of medical certificates issued by a medical doctor may also be submitted, provided they contain the same items of information as those given in the templates. More information on the applicable rules and on the way leave is managed at CERN can be found in the Admin e-guide web pages. Human Resources department HR.leave@cern.ch

gum production by Xanthomonas campestris pv

African Journals Online (AJOL)

DR TONUKARI NYEROVWO

2012-09-11

Sep 11, 2012 ... 8004) for xanthan gum production in this study. ... strain for xanthan gum production using cassava starch in industrial applications. ... the cassava price is cost-effective relative to other ... For amylase activity determination, a crude enzyme sample (1 ml) .... time point to stop fermentation from an economic.

Conformational changes associated with the binding of zinc acetate at the putative active site of XcTcmJ, a cupin from Xanthomonas campestris pv. campestris

International Nuclear Information System (INIS)

Axelrod, Herbert L.; Kozbial, Piotr; McMullan, Daniel; Krishna, S. Sri; Miller, Mitchell D.; Abdubek, Polat; Acosta, Claire; Astakhova, Tamara; Carlton, Dennis; Caruthers, Jonathan; Chiu, Hsiu-Ju; Clayton, Thomas; Deller, Marc C.; Duan, Lian; Elias, Ylva; Feuerhelm, Julie; Grzechnik, Slawomir K.; Grant, Joanna C.; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kumar, Abhinav; Marciano, David; Morse, Andrew T.; Murphy, Kevin D.; Nigoghossian, Edward; Okach, Linda; Oommachen, Silvya; Paulsen, Jessica; Reyes, Ron; Rife, Christopher L.; Tien, Henry J.; Trout, Christina V.; Bedem, Henry van den; Weekes, Dana; White, Aprilfawn; Xu, Qingping; Zubieta, Chloe; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

2009-01-01

The crystal structure of an RmlC-type cupin with zinc acetate bound at the putative active site reveals significant differences from a previous structure without any bound ligand. The functional implications of the ligand-induced conformational changes are discussed. In the plant pathogen Xanthomonas campestris pv. campestris, the product of the tcmJ gene, XcTcmJ, encodes a protein belonging to the RmlC family of cupins. XcTcmJ was crystallized in a monoclinic space group (C2) in the presence of zinc acetate and the structure was determined to 1.6 Å resolution. Previously, the apo structure has been reported in the absence of any bound metal ion [Chin et al. (2006 ▶), Proteins, 65, 1046–1050]. The most significant difference between the apo structure and the structure of XcTcmJ described here is a reorganization of the binding site for zinc acetate, which was most likely acquired from the crystallization solution. This site is located in the conserved metal ion-binding domain at the putative active site of XcTcmJ. In addition, an acetate was also bound within coordination distance of the zinc. In order to accommodate this binding, rearrangement of a conserved histidine ligand is required as well as several nearby residues within and around the putative active site. These observations indicate that binding of zinc serves a functional role in this cupin protein

Nucleosome-coupled expression differences in closely-related species

Directory of Open Access Journals (Sweden)

Gebbia Marinella

2011-09-01

Full Text Available Abstract Background Genome-wide nucleosome occupancy is negatively related to the average level of transcription factor motif binding based on studies in yeast and several other model organisms. The degree to which nucleosome-motif interactions relate to phenotypic changes across species is, however, unknown. Results We address this challenge by generating nucleosome positioning and cell cycle expression data for Saccharomyces bayanus and show that differences in nucleosome occupancy reflect cell cycle expression divergence between two yeast species, S. bayanus and S. cerevisiae. Specifically, genes with nucleosome-depleted MBP1 motifs upstream of their coding sequence show periodic expression during the cell cycle, whereas genes with nucleosome-shielded motifs do not. In addition, conserved cell cycle regulatory motifs across these two species are more nucleosome-depleted compared to those that are not conserved, suggesting that the degree of conservation of regulatory sites varies, and is reflected by nucleosome occupancy patterns. Finally, many changes in cell cycle gene expression patterns across species can be correlated to changes in nucleosome occupancy on motifs (rather than to the presence or absence of motifs. Conclusions Our observations suggest that alteration of nucleosome occupancy is a previously uncharacterized feature related to the divergence of cell cycle expression between species.

Ecology and distribution of two sympatric, closely related sponge species, Halichondria panicea (Pallas, 1766) and H. bowerbanki Burton, 1930 (Porifera, Demospongiae), with remarks on their speciation

NARCIS (Netherlands)

Vethaak, A.D.; Cronie, R.J.A.; Soest, van R.W.M.

1982-01-01

North Atlantic coastal waters harbour two closely related sympatric sponges belonging to the genus Halichondria, viz. H. panicea and H. bowerbanki. From the study of their littoral and sublittoral microdistribution and ecology in the Oosterschelde area (= Eastern Scheldt, S.W. part of The

[Jealousy in close relationships: personal, relational and situational variables].

Science.gov (United States)

Demirtaş, H Andaç; Dönmez, Ali

2006-01-01

In this study, the effects of personal, situational, and relational variables (such as age, gender, gender role orientation, duration of relationship, relational satisfaction, and physical attractiveness of the partner) on jealousy are investigated. A sample of 454 individuals currently involved in dating or marital relationships (48 % married, 52 % unmarried) completed the Romantic Jealousy Questionnaire, Bem Sex Role Inventory, and Rosenberg Self-Esteem Scale. Stepwise regression analyses and 2 (gender) x2 (gender role orientation) x2 (relational type) ANOVA's were submitted for analyzing the data. Analysis indicated that unmarried people reported higher levels of jealousy than married people (F1-446 = 5.029). Married women reported less jealousy than unmarried women and married women reported more jealousy than married men. Age, relational satisfaction level, expectation level about the duration of the relationship, and physical attractiveness of the partner were unique predictors of the reported level of jealousy (R2 = 0.12; adjusted R2 = 0.11; P physical, emotional, and cognitive responses to jealousy compared to men. Women used more constructive (F1-446 = 6.27) and less destructive strategies than men (F1-446 = 6.27). Unmarried people used more destructive strategies than married people (F1-446 = 3.84). Age, self-esteem, and the duration of the relationship were unique predictors of coping strategies. The present study revealed that jealousy was a multidimensional variable. In particular, relational type, self-esteem, age, relational satisfaction, and sex are highly correlated with jealousy.

A closed unventilated chamber for the measurement of transepidermal water loss.

Science.gov (United States)

Nuutinen, Jouni; Alanen, Esko; Autio, Pekka; Lahtinen, Marjo-Riitta; Harvima, Ilkka; Lahtinen, Tapani

2003-05-01

Open chamber systems for measuring transepidermal water loss (TEWL) have limitations related to ambient and body-induced airflows near the probe, probe size, measurement sites and angles, and measurement range. The aim of the present investigation was to develop a closed chamber system for the TEWL measurement without significant blocking of normal evaporation through the skin. Additionally, in order to use the evaporimeter to measure evaporation rates through other biological and non-biological specimens and in the field applications, a small portable, battery-operated device was a design criteria. A closed unventilated chamber (inner volume 2.0 cm(3) was constructed. For the skin measurement, the chamber with one side open (open surface area 1.0 cm(2) is placed on the skin. The skin application time was investigated at low and high evaporation rates in order to assess the blocking effect of the chamber on normal evaporation. From the rising linear part of the relative humidity (RH) in the chamber the slope was registered. The slope was calibrated into a TEWL value by evaporating water at different temperatures and measuring the water loss of heated samples with a laboratory scale. The closed chamber evaporation technique was compared with a conventional evaporimeter based on an open chamber method (DermaLab), Cortex Technology, Hadsund, Denmark). The reproducibility of the closed chamber method was measured with the water samples and with volar forearm and palm of the hand in 10 healthy volunteers. The skin application time varied between 7 and 9 s and the linear slope region between 3 and 5 s at the evaporation rates of 3-220 g/m(2) h. A correlation coefficient between the TEWL value from the closed chamber measurements and the readings of the laboratory scale was 0.99 (P measurements with the water samples was 4.0% at the evaporation rate of 40 g/m(2) h. A correlation coefficient of the TEWL values between the closed chamber and open chamber measurements was 0

Phytophthora megakarya and P. palmivora, closely related causal agents of cacao black pod rot, underwent increases in genome sizes and gene numbers by different mechanisms

Science.gov (United States)

Phytophthora megakarya (Pmeg) and P. palmivora (Ppal) are closely related species causing black pod rot of cacao. While Ppal is a cosmopolitan plant pathogen, cacao is the only known host of importance for Pmeg. Pmeg is more virulent on cacao than Ppal. Therefore, we have sequenced both the Pmeg and...

Efficient dynamic modeling of manipulators containing closed kinematic loops

Science.gov (United States)

Ferretti, Gianni; Rocco, Paolo

An approach to efficiently solve the forward dynamics problem for manipulators containing closed chains is proposed. The two main distinctive features of this approach are: the dynamics of the equivalent open loop tree structures (any closed loop can be in general modeled by imposing some additional kinematic constraints to a suitable tree structure) is computed through an efficient Newton Euler formulation; the constraint equations relative to the most commonly adopted closed chains in industrial manipulators are explicitly solved, thus, overcoming the redundancy of Lagrange's multipliers method while avoiding the inefficiency due to a numerical solution of the implicit constraint equations. The constraint equations considered for an explicit solution are those imposed by articulated gear mechanisms and planar closed chains (pantograph type structures). Articulated gear mechanisms are actually used in all industrial robots to transmit motion from actuators to links, while planar closed chains are usefully employed to increase the stiffness of the manipulators and their load capacity, as well to reduce the kinematic coupling of joint axes. The accuracy and the efficiency of the proposed approach are shown through a simulation test.

Behaviour and design considerations for continuous flow closed-open-closed liquid microchannels.

Science.gov (United States)

Melin, Jessica; van der Wijngaart, Wouter; Stemme, Göran

2005-06-01

This paper introduces a method of combining open and closed microchannels in a single component in a novel way which couples the benefits of both open and closed microfluidic systems and introduces interesting on-chip microfluidic behaviour. Fluid behaviour in such a component, based on continuous pressure driven flow and surface tension, is discussed in terms of cross sectional flow behaviour, robustness, flow-pressure performance, and its application to microfluidic interfacing. The closed-open-closed microchannel possesses the versatility of upstream and downstream closed microfluidics along with open fluidic direct access. The device has the advantage of eliminating gas bubbles present upstream when these enter the open channel section. The unique behaviour of this device opens the door to applications including direct liquid sample interfacing without the need for additional and bulky sample tubing.

Close correlation of herpes zoster-induced voiding dysfunction with severity of zoster-related pain: A single faculty retrospective study.

Science.gov (United States)

Fujii, Mizue; Takahashi, Ichiro; Honma, Masaru; Ishida-Yamamoto, Akemi

2015-11-01

Herpes zoster (HZ), a common vesiculo-erythematous skin disease associated with reactivation of varicella zoster virus in the cranial nerve, dorsal root, and autonomic ganglia, is accompanied by several related symptoms represented by postherpetic neuralgia. Among them, involvement of vesicorectal dysfunction is relatively rare. The vesicorectal symptom can usually be recovered in transient course, but is quite important in terms of impaired quality of life. Male individuals affected with HZ and skin lesions on sacral dermatome have been reported as independent risk factors of zoster-related voiding dysfunction. In this study, urinary symptoms were focused upon and six patients with zoster-related voiding dysfunction at a single faculty of dermatology in Japan from 2009 to 2014 were retrospectively analyzed. All patients showed HZ lesions on the sacral area and the urinary symptom recovered in approximately 2 months (14 days to 7 months). The term of treatment for zoster-associated urinary dysfunction was positively correlated with that for zoster-related pain without significance (r = 0.661, P = 0.153). Average treatment term for pain relief of sacral HZ accompanied by voiding dysfunction (91.3 ± 76.44 days) was significantly longer than that of sacral HZ without urinary symptom (18.9 ± 20.42 days) (P = 0.032). These results suggested that zoster-related voiding dysfunction would mainly be involved in sacral HZ and closely associated with severity of zoster-related pain. Dermatologists should be aware that severe zoster-related pain accompanied by sacral HZ, which is related to prolonged treatment of pain relief, can be a predictive factor of voiding dysfunction. © 2015 Japanese Dermatological Association.

Black hole in closed spacetime with an anisotropic fluid

Science.gov (United States)

Kim, Hyeong-Chan

2017-09-01

We study spherically symmetric geometries made of anisotropic perfect fluid based on general relativity. The purpose of this work is to find and classify black hole solutions in closed spacetime. In a general setting, we find that a static and closed space exists only when the radial pressure is negative but its size is smaller than the density. The Einstein equation is eventually cast into a first-order autonomous equation on a two-dimensional plane of scale-invariant variables, which are equivalent to the Tolman-Oppenheimer-Volkoff equation in general relativity. Then, we display various solution curves numerically. An exact solution describing a black hole solution in a closed spacetime was known in [I. Cho and H. C. Kim, Phys. Rev. D 95, 084052 (2017), 10.1103/PhysRevD.95.084052], which bears a naked singularity and negative-energy era. We find that these two deficits can be remedied when ρ +3 p1>0 and ρ +p1+2 p2<0 , where the second violates the strong energy condition.

Simulation and correction of the closed orbit in the cooler synchrotron COSY

International Nuclear Information System (INIS)

Dinev, D.

1990-11-01

In this paper the problem of COSY closed orbit control and its correction is discussed. The results of a simulation of the COSY closed orbit and its correction using different correction methods are given. The interactive computer program ORBIT, created especially for the simulation and correction of the COSY closed orbit, is described. The paper includes as well a survey of the orbit correction methods and related topics. (orig.)

Developmental success, stability, and plasticity in closely related parthenogenetic and sexual lizards (Heteronotia, Gekkonidae).

Science.gov (United States)

Kearney, Michael; Shine, Richard

2004-07-01

The developmental trajectory of an organism is influenced by the interaction between its genes and the environment in which it develops. For example, the phenotypic traits of a hatchling reptile can be influenced by the organism's genotype, by incubation temperature, and by genetically coded norms of reaction for thermally labile traits. The evolution of parthenogenesis provides a unique opportunity to explore such effects: a hybrid origin of this trait in vertebrates modifies important aspects of the genotype (e.g., heterozygosity, polyploidy) and may thus impact not only on the phenotype generally, but also on the ways in which incubation temperature affects expression of the phenotype. The scarcity of vertebrate parthenogenesis has been attributed to developmental disruptions, but previous work has rarely considered reaction norms of embryogenesis in this respect. We used closely related sexual and asexual races of the Australian gecko Heteronotia binoei, which include those with multiple origins of parthenogenesis, to explore the ways in which reproductive modes (sexual, asexual), incubation temperatures (24, 27, and 30 degrees C), and the interaction between these factors affected hatchling phenotypes. The hatchling traits we considered included incubation period, incidence of deformities, hatchling survivorship, body size and shape, scalation (including fluctuating asymmetry), locomotor performance, and growth rate. Developmental success was slightly reduced (higher proportion of abnormal offspring) in parthenogenetic lineages although there was no major difference in hatching success. Incubation temperature affected a suite of traits including incubation period, tail length, body mass relative to egg mass, labial scale counts, running speed, growth rate, and hatchling survival. Our data also reveal an interaction between reproductive modes and thermal regimes, with the phenotypic traits of parthenogenetic lizards less sensitive to incubation temperature than

Sentence comprehension following moderate closed head injury in adults.

Science.gov (United States)

Leikin, Mark; Ibrahim, Raphiq; Aharon-Peretz, Judith

2012-09-01

The current study explores sentence comprehension impairments among adults following moderate closed head injury. It was hypothesized that if the factor of syntactic complexity significantly affects sentence comprehension in these patients, it would testify to the existence of syntactic processing deficit along with working-memory problems. Thirty-six adults (18 closed head injury patients and 18 healthy controls matched in age, gender, and IQ) participated in the study. A picture-sentence matching task together with various tests for memory, language, and reading abilities were used to explore whether sentence comprehension impairments exist as a result of a deficit in syntactic processing or of working-memory dysfunction. Results indicate significant impairment in sentence comprehension among adults with closed head injury compared with their non-head-injured peers. Results also reveal that closed head injury patients demonstrate considerable decline in working memory, short-term memory, and semantic knowledge. Analysis of the results shows that memory impairment and syntactic complexity contribute significantly to sentence comprehension difficulties in closed head injury patients. At the same time, the presentation mode (spoken or written language) was found to have no effect on comprehension among adults with closed head injury, and their reading abilities appear to be relatively intact.

Testing DNA barcodes in closely related species of Curcuma (Zingiberaceae) from Myanmar and China.

Science.gov (United States)

Chen, Juan; Zhao, Jietang; Erickson, David L; Xia, Nianhe; Kress, W John

2015-03-01

The genus Curcuma L. is commonly used as spices, medicines, dyes and ornamentals. Owing to its economic significance and lack of clear-cut morphological differences between species, this genus is an ideal case for developing DNA barcodes. In this study, four chloroplast DNA regions (matK, rbcL, trnH-psbA and trnL-F) and one nuclear region (ITS2) were generated for 44 Curcuma species and five species from closely related genera, represented by 96 samples. PCR amplification success rate, intra- and inter-specific genetic distance variation and the correct identification percentage were taken into account to assess candidate barcode regions. PCR and sequence success rate were high in matK (89.7%), rbcL (100%), trnH-psbA (100%), trnL-F (95.7%) and ITS2 (82.6%) regions. The results further showed that four candidate chloroplast barcoding regions (matK, rbcL, trnH-psbA and trnL-F) yield no barcode gaps, indicating that the genus Curcuma represents a challenging group for DNA barcoding. The ITS2 region presented large interspecific variation and provided the highest correct identification rates (46.7%) based on BLASTClust method among the five regions. However, the ITS2 only provided 7.9% based on NJ tree method. An increase in discriminatory power needs the development of more variable markers. © 2014 John Wiley & Sons Ltd.

Evidence for nonallopatric speciation among closely related sympatric Heliotropium species in the Atacama Desert.

Science.gov (United States)

Luebert, Federico; Jacobs, Pit; Hilger, Hartmut H; Muller, Ludo A H

2014-02-01

The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus Heliotropium in the Atacama Desert. We used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using divergence outlier analysis (DOA). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among-species differentiation accounts for 35% of the total genetic differentiation (F ST = 0.35), and F ST between species pairs is positively correlated with phylogenetic distance. DOA suggests that few loci are subject to positive selection, which is in line with a scenario of nonallopatric speciation. These results support the idea that sympatric species of Heliotropium sect. Cochranea are under an ongoing speciation process, characterized by a fluctuation of population ranges in response to pulses of arid and humid periods during Quaternary times.

Like will to like: abundances of closely related species can predict susceptibility to intestinal colonization by pathogenic and commensal bacteria.

Science.gov (United States)

Stecher, Bärbel; Chaffron, Samuel; Käppeli, Rina; Hapfelmeier, Siegfried; Freedrich, Susanne; Weber, Thomas C; Kirundi, Jorum; Suar, Mrutyunjay; McCoy, Kathy D; von Mering, Christian; Macpherson, Andrew J; Hardt, Wolf-Dietrich

2010-01-01

The intestinal ecosystem is formed by a complex, yet highly characteristic microbial community. The parameters defining whether this community permits invasion of a new bacterial species are unclear. In particular, inhibition of enteropathogen infection by the gut microbiota ( = colonization resistance) is poorly understood. To analyze the mechanisms of microbiota-mediated protection from Salmonella enterica induced enterocolitis, we used a mouse infection model and large scale high-throughput pyrosequencing. In contrast to conventional mice (CON), mice with a gut microbiota of low complexity (LCM) were highly susceptible to S. enterica induced colonization and enterocolitis. Colonization resistance was partially restored in LCM-animals by co-housing with conventional mice for 21 days (LCM(con21)). 16S rRNA sequence analysis comparing LCM, LCM(con21) and CON gut microbiota revealed that gut microbiota complexity increased upon conventionalization and correlated with increased resistance to S. enterica infection. Comparative microbiota analysis of mice with varying degrees of colonization resistance allowed us to identify intestinal ecosystem characteristics associated with susceptibility to S. enterica infection. Moreover, this system enabled us to gain further insights into the general principles of gut ecosystem invasion by non-pathogenic, commensal bacteria. Mice harboring high commensal E. coli densities were more susceptible to S. enterica induced gut inflammation. Similarly, mice with high titers of Lactobacilli were more efficiently colonized by a commensal Lactobacillus reuteri(RR) strain after oral inoculation. Upon examination of 16S rRNA sequence data from 9 CON mice we found that closely related phylotypes generally display significantly correlated abundances (co-occurrence), more so than distantly related phylotypes. Thus, in essence, the presence of closely related species can increase the chance of invasion of newly incoming species into the gut

N=1 Mirror Symmetry and Open/Closed String Duality

CERN Document Server

Mayr, Peter

2002-01-01

We show that the exact N=1 superpotential of a class of 4d string compactifications is computed by the closed topological string compactified to two dimensions. A relation to the open topological string is used to define a special geometry for N=1 mirror symmetry. Flat coordinates, an N=1 mirror map for chiral multiplets and the exact instanton corrected superpotential are obtained from the periods of a system of differential equations. The result points to a new class of open/closed string dualities which map individual string world-sheets with boundary to ones without. It predicts an mathematically unexpected coincidence of the closed string Gromov-Witten invariants of one Calabi-Yau geometry with the open string invariants of the dual Calabi-Yau.

Utilização do soro de mandioca como substrato fermentativo para a biosíntese de goma xantana: viscosidade aparente e produção Use of the cassava serum as fermentative substrate in xanthan gum biosynthesis: apparent viscosity and production

Directory of Open Access Journals (Sweden)

Líllian V. Brandão

2010-09-01

Full Text Available Goma xantana é um biopolímero comercial produzido por fermentação de glicose e Xanthomonas com larga aplicação industrial. O objetivo deste trabalho foi estudar a síntese e a viscosidade da goma obtida por cepas nativas de Xanthomonas campestris utilizando soro de mandioca como substrato fermentativo alternativo. Três tipos de Xanthomonas foram utilizados. A maior produção foi de 13,83 g.L-1 obtida do meio fermentativo com X. campestris mangiferaeindicae a 25 ºC, 250 rpm por 120 horas apresentando uma viscosidade aparente de 96,14 cP na concentração de 2,0% de solução de xantana a 25 s-1, 25 ºC. O uso do resíduo industrial de soro de mandioca para biossíntese da xantana é uma alternativa de baixo custo para o processo fermentativo e um destino para esse soro.Xanthan gum is a commercial biopolymer produced by fermentation of glucose and Xanthomonas with many industrial applications. The objective of this work was to study the synthesis and the viscosity of xanthan obtained from native strains of Xanthomonas campestris using cassava as an alternative fermentative substrate. Three kinds of Xanthomonas were used. The highest production was 13.83 g.L-1 obtained with X. campestris mangiferaeindicae fermented at 25 ºC, 250 rpm during 120 hours and presenting apparent viscosity 96.14 cP in the concentration of 2.0% of xanthan solution at 25 s-1, 25 ºC. The use of the industrial residue of cassava serum for biosynthesis of xanthan is a low cost alternative for the fermentation process and a noble use for this waste.

Acute effects on pulmonary function in young healthy adults exposed to traffic-related air pollution in semi-closed transport hub in Beijing.

Science.gov (United States)

Huang, Jing; Deng, Furong; Wu, Shaowei; Zhao, Yan; Shima, Masayuki; Guo, Bin; Liu, Qichen; Guo, Xinbiao

2016-09-01

Transport hub is an important part of urban comprehensive transportation system. Traffic-related air pollution can reach high level because of difficulty of diffusion and increase of emission in transport hub. However, whether exposure in this semi-closed traffic micro-environment causes acute changes in pulmonary function of commuters still needs to be explored. Forty young healthy adults participated in this randomized, crossover study. Each participant underwent 2 h exposure in a designated transport hub and, on a separate occasion, in an appointed park. Personal exposures to fine particulate matter (PM 2.5 ), black carbon (BC) and carbon monoxide (CO) were measured. Forced expiratory volume in 1 s (FEV 1 ) and peak expiratory flow (PEF) were assessed pre-, during and post-exposure. Mixed linear models were used to analyze the pulmonary effects of traffic-related air pollutants. Participants had significantly higher exposures to PM 2.5 , BC and CO in the transport hub than in the park. Exposure in transport hub induced significant reductions in FEV 1 and PEF compared with the park during exposure 1 and 2 h. The reductions were significant associated with traffic-related air pollutants. For instance, per 10 μg/m 3 increment in PM 2.5 was associated with -0.15 % (95 % CI -0.28, -0.02 %) reduction in FEV 1 during exposure 2 h. However, effects became attenuate after 2 h exposure. Short-term exposure in transport hub had acute reduction effects on pulmonary function. More attention should be paid to the health effects of exposure in the semi-closed traffic micro-environment.

The Social Psychology of Gender Differences and Procedural Justice in Close Relationships

NARCIS (Netherlands)

Tumewu, M.

2007-01-01

In this dissertation the influence of procedural justice on the reactions of men and women in contexts related to close relationships. Women are thought to be more sensitive to procedural justice than men because women are more caring towards others and value their close relationships more than men.

School Closings in Philadelphia

Science.gov (United States)

Jack, James; Sludden, John

2013-01-01

In 2012, the School District of Philadelphia closed six schools. In 2013, it closed 24. The closure of 30 schools has occurred amid a financial crisis, headlined by the district's $1.35 billion deficit. School closures are one piece of the district's plan to cut expenditures and close its budget gap. The closures are also intended to make…

Hedonic Benefits of Close and Distant Interaction Partners: The Mediating Roles of Social Approval and Authenticity.

Science.gov (United States)

Venaglia, Rachel B; Lemay, Edward P

2017-09-01

The current research utilized ecological momentary assessment methodology to examine affective responses to interacting with close versus distant interaction partners during naturally occurring social interactions, and to test predictions regarding the mediating roles of perceived social approval and authenticity. Analysis of 4,602 social interactions reported by 176 participants suggested that, relative to interactions with distant partners, interactions with close partners were characterized by more positive affect. This effect was mediated by perceived social approval and authenticity. These findings suggest that social interactions with close others confer greater hedonic benefits relative to interactions with distant partners due to greater confidence in social approval and feelings of authenticity. Exploratory analyses suggested that interactions with close partners featured warmer and less shy behavior, and that participants who placed more importance on close relationships (as measured by high relational-interdependent self-construal) experienced more approval and authenticity in their interactions, particularly with distant partners.

2018-03-13T08:12:57Z https://www.ajol.info/index.php/all/oai oai:ojs ...

African Journals Online (AJOL)

Acidovorax avenae subsp. avenae ainsi que Xanthomonas oryzae pv. oryzae ont été chacune détectées dans 50 % des échantillons et Burkholderia Glumae dans 16,66 %. 52 % des bactéries identifiées se rapportent à Acidovorax avenae subsp. avenae, 35 % à Xanthomonas oryzae pv. oryzae et 13 % à Burkholderia ...

Four aspects of self-image close to death at home

Directory of Open Access Journals (Sweden)

Ida Carlander

2011-04-01

Full Text Available Living close to death means an inevitable confrontation with one's own existential limitation. In this article, we argue that everyday life close to death embodies an identity work in progress. We used a narrative approach and a holistic-content reading to analyze 12 interviews conducted with three persons close to death. By illuminating the unique stories and identifying patterns among the participants’ narratives, we found four themes exemplifying important aspects of the identity work related to everyday life close to death. Two of the themes, named “Inside and outside of me” and “Searching for togetherness,” represented the core of the self-image and were framed by the other themes, “My place in space” and “My death and my time.” Our findings elucidate the way the individual stories moved between the past, the present, and the future. This study challenges the idea that everyday life close to impending death primarily means limitations. The findings show that the search for meaning, new knowledge, and community can form a part of a conscious and ongoing identity work close to death.

Four aspects of self-image close to death at home

Science.gov (United States)

Carlander, Ida; Ternestedt, Britt-Marie; Sahlberg-Blom, Eva; Hellström, Ingrid; Sandberg, Jonas

2011-01-01

Living close to death means an inevitable confrontation with one's own existential limitation. In this article, we argue that everyday life close to death embodies an identity work in progress. We used a narrative approach and a holistic-content reading to analyze 12 interviews conducted with three persons close to death. By illuminating the unique stories and identifying patterns among the participants’ narratives, we found four themes exemplifying important aspects of the identity work related to everyday life close to death. Two of the themes, named “Inside and outside of me” and “Searching for togetherness,” represented the core of the self-image and were framed by the other themes, “My place in space” and “My death and my time.” Our findings elucidate the way the individual stories moved between the past, the present, and the future. This study challenges the idea that everyday life close to impending death primarily means limitations. The findings show that the search for meaning, new knowledge, and community can form a part of a conscious and ongoing identity work close to death. PMID:21526139

Complaints related to mandibular function impairment after closed treatment of fractures of the mandibular condyle

NARCIS (Netherlands)

Niezen, E. T.; Bos, R. R. M.; de Bont, L. G. M.; Stegenga, B.; Dijkstra, P. U.

This study analysed the relationship between complaints and mandibular function after closed treatment of fractures of the mandibular condyle in a prospective study. In a I-year follow-up, complaints were assessed during physical examination and function was assessed using the mandibular function

Romantic relationships and psychological distress among adolescents: Moderating role of friendship closeness.

Science.gov (United States)

Chow, Chong Man; Ruhl, Holly; Buhrmester, Duane

2015-11-01

The formation of romantic relationships and friendships in adolescence is a defining milestone in the progression toward social maturity. Thus, examining adolescents' friendship and romantic experiences serves a vital role in understanding their psychological adjustment. The main purposes of the current study were to examine (a) whether romantic involvement, romantic security, and friendship closeness were independently predictive of late adolescents' depression and loneliness, and (b) whether friendship closeness would moderate the negative effects of adolescents' lower degrees of romantic involvement and romantic security on depression and loneliness. Data came from 12th grade adolescents (N = 110, 53 females) as well as their parents and a same-sex best friend. Adolescents reported on their romantic involvement, romantic security, and psychological distress. Parent reports of adolescents' depressive symptoms and friend reports of friendship closeness were also included. Higher degrees of romantic involvement and friendship closeness were related to lower degrees of loneliness. Higher degrees of romantic security were related to lower degrees of depression and loneliness. The effect of romantic involvement on depression and loneliness was moderated by friendship closeness. Also, the effect of romantic security on loneliness was moderated by friendship closeness. Future research should focus on the interactive roles that friendships and romantic relationships play in the emergence of psychopathology during adolescence. © The Author(s) 2015.

Temperature as an ecological factor in the distribution of two closely related freshwater Triclads: an experimental study. [Polycelis tenuis, polycelis nigra

Energy Technology Data Exchange (ETDEWEB)

Lascombe, C.; Pattee, E.; Bornard, C.

1975-01-01

The influence of temperature on the ecophysiology of two closely related limnophilic Triclads, Polycelis tenuis and P. nigra, in the Lyons region was investigated. Both species have the same physiological rate in the middle zone of the temperature range, but P. tenuis prevails at both ends of the range. It tolerates higher temperatures and its reproduction rate is greater in the cold. Also, because of the existence of physiological races, it seems adapted to a greater diversity of situations. It appears as a real eurytherm. These different points contribute to the explanation of the habitat of both species in the region.

Genomics of Sponge-Associated Streptomyces spp. Closely Related to Streptomyces albus J1074: Insights into Marine Adaptation and Secondary Metabolite Biosynthesis Potential

Science.gov (United States)

Ian, Elena; Malko, Dmitry B.; Sekurova, Olga N.; Bredholt, Harald; Rückert, Christian; Borisova, Marina E.; Albersmeier, Andreas; Kalinowski, Jörn; Gelfand, Mikhail S.; Zotchev, Sergey B.

2014-01-01

A total of 74 actinomycete isolates were cultivated from two marine sponges, Geodia barretti and Phakellia ventilabrum collected at the same spot at the bottom of the Trondheim fjord (Norway). Phylogenetic analyses of sponge-associated actinomycetes based on the 16S rRNA gene sequences demonstrated the presence of species belonging to the genera Streptomyces, Nocardiopsis, Rhodococcus, Pseudonocardia and Micromonospora. Most isolates required sea water for growth, suggesting them being adapted to the marine environment. Phylogenetic analysis of Streptomyces spp. revealed two isolates that originated from different sponges and had 99.7% identity in their 16S rRNA gene sequences, indicating that they represent very closely related strains. Sequencing, annotation, and analyses of the genomes of these Streptomyces isolates demonstrated that they are sister organisms closely related to terrestrial Streptomyces albus J1074. Unlike S. albus J1074, the two sponge streptomycetes grew and differentiated faster on the medium containing sea water. Comparative genomics revealed several genes presumably responsible for partial marine adaptation of these isolates. Genome mining targeted to secondary metabolite biosynthesis gene clusters identified several of those, which were not present in S. albus J1074, and likely to have been retained from a common ancestor, or acquired from other actinomycetes. Certain genes and gene clusters were shown to be differentially acquired or lost, supporting the hypothesis of divergent evolution of the two Streptomyces species in different sponge hosts. PMID:24819608

Phylogeny, Traits, and Biodiversity of a Neotropical Bat Assemblage: Close Relatives Show Similar Responses to Local Deforestation.

Science.gov (United States)

Frank, Hannah K; Frishkoff, Luke O; Mendenhall, Chase D; Daily, Gretchen C; Hadly, Elizabeth A

2017-08-01

If species' evolutionary pasts predetermine their responses to evolutionarily novel stressors, then phylogeny could predict species survival in an increasingly human-dominated world. To understand the role of phylogenetic relatedness in structuring responses to rapid environmental change, we focused on assemblages of Neotropical bats, an ecologically diverse and functionally important group. We examined how taxonomic and phylogenetic diversity shift between tropical forest and farmland. We then explored the importance of evolutionary history by ascertaining whether close relatives share similar responses to environmental change and which species traits might mediate these trends. We analyzed a 5-year data set (5,011 captures) from 18 sites in a countryside landscape in southern Costa Rica using statistical models that account and correct for imperfect detection of species across sites, spatial autocorrelation, and consideration of spatial scale. Taxonomic and phylogenetic diversity decreased with deforestation, and assemblages became more phylogenetically clustered. Species' responses to deforestation were strongly phylogenetically correlated. Body mass and absolute wing loading explained a substantial portion of species variation in species' habitat preferences, likely related to these traits' influence on maneuverability in cluttered forest environments. Our findings highlight the role that evolutionary history plays in determining which species will survive human impacts and the need to consider diversity metrics, evolutionary history, and traits together when making predictions about species persistence for conservation or ecosystem functioning.

Yeasts from Scarlet ibises (Eudocimus ruber): A focus on monitoring the antifungal susceptibility of Candida famata and closely related species.

Science.gov (United States)

Brilhante, Raimunda Sâmia Nogueira; Silva, Aline Lobão da; Monteiro, Frederico Ozanan Barros; Guedes, Glaucia Morgana de Melo; Sales, Jamille Alencar; Oliveira, Jonathas Sales de; Maia Junior, José Erisvaldo; Miranda, Stefânia Araújo; Sidrim, José Júlio Costa; Alencar, Lucas Pereira de; Castelo-Branco, Débora Souza Collares Maia; Cordeiro, Rossana de Aguiar; Pereira Neto, Waldemiro de Aquino; Rocha, Marcos Fábio Gadelha

2017-10-01

This study aimed to identify yeasts from the gastrointestinal tract of scarlet ibises (Eudocimus ruber) and from plant material collected from the environment where they live. Then, the isolates phenotypically identified as Candida famata were submitted to molecular identification of their closely related species and evaluated for their antifungal susceptibility and possible resistance mechanisms to antifungal drugs. Cloacal swabs from 20 scarlet ibises kept in captivity at Mangal das Garças Park (Brazil), pooled stool samples (n = 20) and samples of trunks and hollow of trees (n = 20) obtained from their enclosures were collected. The samples were seeded on Sabouraud agar supplemented with chloramphenicol. The 48 recovered isolates were phenotypically identified as 15 Candida famata, 13 Candida catenulata, 2 Candida intermedia, 1 Candida lusitaniae, 2 Candida guilliermondii, 1 Candida kefyr, 1 Candida amapae, 1 Candida krusei, 8 Trichosporon spp., and 4 Rhodotorula spp. The C. famata isolates were further identified as 3 C. famata, 8 Debaryomyces nepalensis, and 4 C. palmioleophila. All C. famata and C. palmioleophila were susceptible to caspofungin and itraconazole, while one D. nepalensis was resistant to fluconazole and voriconazole. This same isolate and another D. nepalensis had lower amphotericin B susceptibility. The azole resistant strain had an increased efflux of rhodamine 6G and an alteration in the membrane sterol content, demonstrating multifactorial resistance mechanism. Finally, this research shows that scarlet ibises and their environment harbor C. famata and closely related species, including antifungal resistant isolates, emphasizing the need of monitoring the antifungal susceptibility of these yeast species. © The Author 2017. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Death of a Close Relative and the Risk of Suicide in Sweden-A Large Scale Register-Based Case-Crossover Study.

Directory of Open Access Journals (Sweden)

Hanna Mogensen

Full Text Available Bereavement is thought to be a risk factor for suicide but the association has not been thoroughly investigated according to specific sensitive time periods and risk groups using a self-matched design. We aimed to 1 determine the risk of suicide within the first year after death of a close relative, 2 investigate if and how the risk changes within this time window and 3 determine if sex, age, and type of relationship, affect this association.A self-matched, case-crossover study was performed by linking Swedish registers. In total, 31 059 individuals with suicide between 1990 and 2011 were included. Different periods within the year prior to the suicide were compared with corresponding periods one year earlier in the same individual's life. Conditional logistic regression was used to calculate odds ratios (OR and 95% confidence intervals (CI for suicide after death of a close relative.Increased ORs of suicide were seen during the first month, OR 1·77 (95% CI 1·35-2·34, and the first half-year, 1·27 (1·13-1·43. An even higher OR was found within the first week, 3·43 (1·89-6·22. Patterns were similar for women and men and across age groups. Death of a partner or child but not death of a sibling or parent was associated with a significantly increased suicide risk. The strongest association was seen after death of a partner in individuals aged 45 and older.These findings provide knowledge of sensitive time periods and at-risk groups in the early period of bereavement. Due to the use of a self-matched study design, methodological challenges of unmeasured residual confounding could be overcome.

Analysis of DNA methylation related to rice adult plant resistance to bacterial blight based on methylation-sensitive AFLP (MSAP) analysis.

Science.gov (United States)

Sha, A H; Lin, X H; Huang, J B; Zhang, D P

2005-07-01

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. The rice cultivar Wase Aikoku 3 becomes resistant to the blight pathogen Xanthomonas oryzae pv. oryzae at the adult stage. Using methylation-sensitive amplified polymorphism (MSAP) analysis, we compared the patterns of cytosine methylation in seedlings and adult plants of the rice cultivar Wase Aikoku 3 that had been inoculated with the pathogen Xanthomonas oryzae pv. oryzae, subjected to mock inoculation or left untreated. In all, 2000 DNA fragments, each representing a recognition site cleaved by either or both of two isoschizomers, were amplified using 60 pairs of selective primers. A total of 380 sites were found to be methylated. Of these, 45 showed differential cytosine methylation among the seedlings and adult plants subjected to different treatments, and overall levels of methylation were higher in adult plants than in seedlings. All polymorphic fragments were sequenced, and six showed homology to genes that code for products of known function. Northern analysis of three fragments indicated that their expression varied with methylation pattern, with hypermethylation being correlated with repression of transcription, as expected. The results suggest that significant differences in cytosine methylation exist between seedlings and adult plants, and that hypermethylation or hypomethylation of specific genes may be involved in the development of adult plant resistance (APR) in rice plants.

Close binary stars

International Nuclear Information System (INIS)

Larsson-Leander, G.

1979-01-01

Studies of close binary stars are being persued more vigorously than ever, with about 3000 research papers and notes pertaining to the field being published during the triennium 1976-1978. Many major advances and spectacular discoveries were made, mostly due to increased observational efficiency and precision, especially in the X-ray, radio, and ultraviolet domains. Progress reports are presented in the following areas: observational techniques, methods of analyzing light curves, observational data, physical data, structure and models of close binaries, statistical investigations, and origin and evolution of close binaries. Reports from the Coordinates Programs Committee, the Committee for Extra-Terrestrial Observations and the Working Group on RS CVn binaries are included. (Auth./C.F.)

75 FR 7370 - Closed Captioning of Video Programming; Closed Captioning Requirements for Digital Television...

Science.gov (United States)

2010-02-19

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 79 [CG Docket No. 05-231; ET Docket No. 99-254; FCC 08-255] Closed Captioning of Video Programming; Closed Captioning Requirements for Digital Television... Captioning of Video Programming; Closed Captioning Requirements for Digital Television Receivers, Declaratory...

Transcriptome analysis of WRKY gene family in Oryza officinalis Wall ex Watt and WRKY genes involved in responses to Xanthomonas oryzae pv. oryzae stress.

Science.gov (United States)

Jiang, Chunmiao; Shen, Qingxi J; Wang, Bo; He, Bin; Xiao, Suqin; Chen, Ling; Yu, Tengqiong; Ke, Xue; Zhong, Qiaofang; Fu, Jian; Chen, Yue; Wang, Lingxian; Yin, Fuyou; Zhang, Dunyu; Ghidan, Walid; Huang, Xingqi; Cheng, Zaiquan

2017-01-01

Oryza officinalis Wall ex Watt, a very important and special wild rice species, shows abundant genetic diversity and disease resistance features, especially high resistance to bacterial blight. The molecular mechanisms of bacterial blight resistance in O. officinalis have not yet been elucidated. The WRKY transcription factor family is one of the largest gene families involved in plant growth, development and stress response. However, little is known about the numbers, structure, molecular phylogenetics, and expression of the WRKY genes under Xanthomonas oryzae pv. oryzae (Xoo) stress in O. officinalis due to lacking of O. officinalis genome. Therefore, based on the RNA-sequencing data of O. officinalis, we performed a comprehensive study of WRKY genes in O. officinalis and identified 89 OoWRKY genes. Then 89 OoWRKY genes were classified into three groups based on the WRKY domains and zinc finger motifs. Phylogenetic analysis strongly supported that the evolution of OoWRKY genes were consistent with previous studies of WRKYs, and subgroup IIc OoWRKY genes were the original ancestors of some group II and group III OoWRKYs. Among the 89 OoWRKY genes, eight OoWRKYs displayed significantly different expression (>2-fold, pWRKY family of transcription factors in O.officinalis. Insight was gained into the classification, evolution, and function of the OoWRKY genes, revealing the putative roles of eight significantly different expression OoWRKYs in Xoo strains PXO99 and C5 stress responses in O.officinalis. This study provided a better understanding of the evolution and functions of O. officinalis WRKY genes, and suggested that manipulating eight significantly different expression OoWRKYs would enhance resistance to bacterial blight.

Finger taps and constipation are closely related to symptoms of overactive bladder in male patients with Parkinson's disease.

Science.gov (United States)

Tsujimura, Akira; Yamamoto, Yoichi; Sakoda, Saburo; Okuda, Hidenobu; Yamamoto, Keisuke; Fukuhara, Shinichiro; Yoshioka, Iwao; Kiuchi, Hiroshi; Takao, Tetsuya; Miyagawa, Yasushi; Nonomura, Norio

2014-01-01

To assess which motor and non-motor symptoms are closely related to overactive bladder severity in male patients with Parkinson's disease. A total of 160 male patients (mean age 71.4 ± 8.2 years) diagnosed with Parkinson's disease were included in the present study at Osaka University and affiliated hospitals. The severity of Parkinson's disease was classified as stage 3, 4 or 5 based on the Hoehn and Yahr staging system. Disease duration was 8.9 ± 5.1 years. Age, seven items from the Unified Parkinson's Disease Rating Scale motor section part III and three non-motor symptoms were assessed by multivariate analysis for their impact on the overactive bladder symptom score, a specific questionnaire for overactive bladder. Overactive bladder symptom score was significantly higher in the group with severe motor symptoms related to finger taps and gait than in the group with mild motor symptoms related to these two factors. Furthermore, overactive bladder symptom score of patients with erectile dysfunction and constipation was significantly higher than that in patients without these symptoms. Multivariate analysis identified only finger taps and constipation as factors independently associated with overactive bladder symptom score. Although a study on a larger scale is required to further assess the association of Parkinson's disease symptoms with overactive bladder symptom score, information on finger taps and severity of constipation should be obtained when assessing urological patients with Parkinson's disease. © 2013 The Japanese Urological Association.

Depression, anxiety and quality of life in suicide survivors: a comparison of close and distant relationships.

Science.gov (United States)

Mitchell, Ann M; Sakraida, Teresa J; Kim, Yookyung; Bullian, Leann; Chiappetta, Laurel

2009-02-01

The study's purpose was to describe and compare depression, anxiety, and quality of life, by degree of relationship, between closely related and distantly related survivors (persons close to the suicide victim, or "suicide survivors"; N = 60) during the acute phase of bereavement (within 1 month of the death). The close relationship category included spouses, parents, children, and siblings, whereas the distant relationship category included in-laws, aunts/uncles, and nieces/nephews. Analysis of covariance examined differences between the two groups on the symptom measures. Results indicate that, after controlling for age and gender effects, closely related survivors had significantly higher mean levels of depression and anxiety and had lower levels of mental health quality of life. There were no statistically significant differences on the physical health quality of life subscale.

Symmetry and history quantum theory: An analog of Wigner close-quote s theorem

International Nuclear Information System (INIS)

Schreckenberg, S.

1996-01-01

The basic ingredients of the open-quote open-quote consistent histories close-quote close-quote approach to quantum theory are a space UP of open-quote open-quote history propositions close-quote close-quote and a space D of open-quote open-quote decoherence functionals.close-quote close-quote In this article we consider such history quantum theories in the case where UP is given by the set of projectors P(V) on some Hilbert space V. We define the notion of a open-quote open-quote physical symmetry of a history quantum theory close-quote close-quote (PSHQT) and specify such objects exhaustively with the aid of an analog of Wigner close-quote s theorem. In order to prove this theorem we investigate the structure of D, define the notion of an open-quote open-quote elementary decoherence functional,close-quote close-quote and show that each decoherence functional can be expanded as a certain combination of these functionals. We call two history quantum theories that are related by a PSHQT open-quote open-quote physically equivalent close-quote close-quote and show explicitly, in the case of history quantum mechanics, how this notion is compatible with one that has appeared previously. copyright 1996 American Institute of Physics

Actor-Observer Bias in Close Relationships: The Role of Self-Knowledge and Self-Related Language.

Science.gov (United States)

Fiedler, Klaus; And Others

1995-01-01

Studied attributional biases in close relationships. Found that partner attributions prevail at the abstract level of adjectives, whereas self-attributions resided at the concrete level of action verbs. Findings underscore language's importance in attributional biases and reveal how people talk in less abstract terms about the self than about…

Closed model of the earth's magnetosphere

International Nuclear Information System (INIS)

Piddington, J.H.

1979-01-01

The existence of large-scale motions within the earth's magnetosphere and that of a long magnetotail were predicted in 1960 as results of a hypothetical frictional interaction between the solar wind and the geomagnetic field. The boundary layer model of this interaction involves the flow of magnetosheath plasma in a magnetospheric boundary layer. The flow is across magnetic field lines, and so the layer must be polarized, with a space charge field nearly balancing the induction field V x B. The space charge tends to discharge through the ionosphere, thus providing some magnetic and related activity as well as the Lorentz frictional force. This closed magnetosphere model has been largely neglected in favor of the reconnection model but is now strongly supported by observational results and their interpretation as follows. (1) The evidence for the reconnection model, increasing activity with a southward interplanetary field and invasion of the polar caps by flare particles, is shown to be equally compatible with the closed field model. (2) The magnetotail grows by the motions of closed flux tubes through the dawn and dusk meridians, a process which depends on the nature of the boundary between magnetosphere and magnetosheath plasmas and perhaps also on the solar wind dynamo. Both of these features depend, in turn, on the direction of the interplanetary magnetic field. (3) Closed field lines entering the tail may be stretched to a few tens of earth radii and then contract back to the corotating magnetosphere. Others enter the long tail and are stretched to hundreds of earth radii and so are pervious to fast solar particles. (4) A new model of the magnetospheric substorm involves the entry of closed field lines into the tail and their rapid return to the corotating magnetosphere. The return is due, first, to the release of their trapped plasma as it becomes electrically polarized and, second, to mounting magnetic and plasma stresses in the inflated magnetotail

Detecção, transmissão e efeito de Xanthomonas campestris pv. campestris na qualidade fisiológica de sementes de brócolis Detection, transmission and effect of Xanthomonas campestris pv. campestris in the physiological quality of broccoli seeds

Directory of Open Access Journals (Sweden)

Nilvanira Donizeti Tebaldi

2007-12-01

Full Text Available A detecção, a transmissão e o efeito de Xanthomonas campestris pv. campestris (Xcc na qualidade fisiológica de sementes de brócolis (Brassica oleracea var. italica foram avaliados, a partir de sementes obtidas de plantas ("Baron, Flórida, Hana Midori Sakata, Precoce Piracicaba de Verão, Ramoso Santana e Sabre" inoculadas com a bactéria, em condições de campo. Para a detecção do patógeno nas sementes foram utilizados os meios de cultura semi-seletivos: SX ágar, NSCAA e BSCAA; a taxa de transmissão da bactéria pelas sementes às plântulas foi avaliada usando semeadura em areia e meio de cultura contido em tubo de ensaio. Para a avaliação da qualidade fisiológica de sementes foram realizados o teste padrão de germinação e os testes de vigor: envelhecimento acelerado, índice de velocidade de emergência, crescimento de plântulas e massa seca. De acordo com os resultados, o meio de cultura semi-seletivo NSCAA foi mais eficaz para detectar Xcc em sementes de brócolis; não houve diferença significativa entre os genótipos na taxa de transmissão da bactéria pelas sementes e Xcc não afetou a germinação e o vigor das sementes.The detection, transmission and the effect of Xanthomomas campestris pv. campestris (Xcc in the physiological quality of broccoli seeds were evaluated. The seeds were obtained from inoculated field plants (`Baron', `Flórida', `Hana Midori Sakata', `Precoce Piracicaba de Verão', `Ramoso Santana' and `Sabre' genotypes with the bacterium. For the seed pathogen detection the semi-selective medium were used: starch for xanthomonads (SX agar, nutrient starch cycloheximide antibiotic agar (NSCAA and basal starch cycloheximide antibiotic agar (BSCAA; the bacteria seeds transmission percentage was evaluated using sand and test tube. The physiological seed quality was evaluated by the standard germination and vigor tests: the accelerated aging, speed of emergence, seedling growth and seedling dry weight. The

Detecção, transmissão e efeito de Xanthomonas campestris pv. campestris na qualidade fisiológica de sementes de brócolis Detection, transmission and effect of Xanthomonas campestris pv. campestris in the physiological quality of broccoli seeds

Directory of Open Access Journals (Sweden)

Nilvanira Donizete Tebaldi

2007-09-01

Full Text Available A detecção, a transmissão e o efeito de Xanthomonas campestris pv. campestris (Xcc na qualidade fisiológica de sementes de brócolis (Brassica oleracea var. italica foram avaliadas, a partir de sementes obtidas de plantas ("Baron, Flórida, Hana Midori Sakata, Precoce Piracicaba de Verão, Ramoso Santana e Sabre" inoculadas com a bactéria, em condições de campo. Para a detecção do patógeno nas sementes foram utilizados os meios de cultura semi-seletivos: SX ágar, NSCAA e BSCAA; a taxa de transmissão da bactéria pelas sementes às plântulas foi avaliada usando semeadura em areia e meio de cultura contido em tubo de ensaio. Para a avaliação da qualidade fisiológica das sementes foram realizados o teste padrão de germinação e os testes de vigor: envelhecimento acelerado, índice de velocidade de emergência, crescimento das plântulas e massa seca. De acordo com os resultados, o meio de cultura semi-seletivo NSCAA foi mais eficaz para detectar Xcc em sementes de brócolis; não houve diferença significativa entre os genótipos na taxa de transmissão da bactéria pelas sementes e Xcc não afetou a germinação e o vigor das sementes.The detection, transmission and the effect of Xanthomomas campestris pv. campestris (Xcc in the physiological quality of broccoli seeds were evaluated. The seeds were obtained from inoculated field plants ('Baron', 'Flórida', 'Hana Midori Sakata', 'Precoce Piracicaba de Verão', 'Ramoso Santana' and 'Sabre' genotypes with the bacterium. For the seed pathogen detection the semi-selective medium were used: starch for xanthomonads (SX agar, nutrient starch cycloheximide antibiotic agar (NSCAA and basal starch cycloheximide antibiotic agar (BSCAA; the bacteria seeds transmission percentage was evaluated using sand and test tube. The physiological seed quality was evaluated by the standard germination and vigor tests: the accelerated aging, speed of emergence, seedling growth and seedling dry weight

On semi star generalized closed sets in bitopological spaces.

Directory of Open Access Journals (Sweden)

K. Kannan

2010-07-01

Full Text Available K. Chandrasekhara Rao and K. Joseph [5] introduced the concepts of semi star generalized open sets and semi star generalized closed sets in a topological space. The same concept was extended to bitopological spaces by K. Chan-drasekhara Rao and K. Kannan [6,7]. In this paper, we continue the study of τ1τ2-s∗g closed sets inbitopology and we introduced the newly related concept of pairwise s∗g-continuous mappings. Also S∗GO-connectedness and S∗GO-compactness are introduced in bitopological spaces and some of their properties are established.

Judging Criterion of Controlled Structures with Closely Spaced Natural Frequencies

International Nuclear Information System (INIS)

Xie Faxiang; Sun Limin

2010-01-01

The structures with closely spaced natural frequencies widely exist in civil engineering; however, the judging criterion of the density of closely spaced frequencies is in dispute. This paper suggests a judging criterion for structures with closely spaced natural frequencies based on the analysis on a controlled 2-DOF structure. The analysis results indicate that the optimal control gain of the structure with velocity feedback is dependent on the frequency density parameter of structure and the maximum attainable additional modal damping ratio is 1.72 times of the frequency density parameter when state feedback is applied. Based on a brief review on the previous researches, a judging criterion related the minimum frequency density parameter and the required mode damping ratio was proposed.

Rapid identification of closely related muscle foods by vibrational spectroscopy and machine learning.

Science.gov (United States)

Ellis, David I; Broadhurst, David; Clarke, Sarah J; Goodacre, Royston

2005-12-01

Muscle foods are an integral part of the human diet and during the last few decades consumption of poultry products in particular has increased significantly. It is important for consumers, retailers and food regulatory bodies that these products are of a consistently high quality, authentic, and have not been subjected to adulteration by any lower-grade material either by accident or for economic gain. A variety of methods have been developed for the identification and authentication of muscle foods. However, none of these are rapid or non-invasive, all are time-consuming and difficulties have been encountered in discriminating between the commercially important avian species. Whilst previous attempts have been made to discriminate between muscle foods using infrared spectroscopy, these have had limited success, in particular regarding the closely related poultry species, chicken and turkey. Moreover, this study includes novel data since no attempts have been made to discriminate between both the species and the distinct muscle groups within these species, and this is the first application of Raman spectroscopy to the study of muscle foods. Samples of pre-packed meat and poultry were acquired and FT-IR and Raman measurements taken directly from the meat surface. Qualitative interpretation of FT-IR and Raman spectra at the species and muscle group levels were possible using discriminant function analysis. Genetic algorithms were used to elucidate meaningful interpretation of FT-IR results in (bio)chemical terms and we show that specific wavenumbers, and therefore chemical species, were discriminatory for each type (species and muscle) of poultry sample. We believe that this approach would aid food regulatory bodies in the rapid identification of meat and poultry products and shows particular potential for rapid assessment of food adulteration.

Glycolysis Is Dynamic and Relates Closely to Respiration Rate in Stored Sugarbeet Roots

Directory of Open Access Journals (Sweden)

Clarice A. Megguer

2017-05-01

storage and that changes in glycolysis are closely related to changes in sugarbeet root respiration.

Generalized Polar Decompositions for Closed Operators in Hilbert Spaces and Some Applications

OpenAIRE

Gesztesy, Fritz; Malamud, Mark; Mitrea, Marius; Naboko, Serguei

2008-01-01

We study generalized polar decompositions of densely defined, closed linear operators in Hilbert spaces and provide some applications to relatively (form) bounded and relatively (form) compact perturbations of self-adjoint, normal, and m-sectorial operators.

7 CFR 1735.94 - Final approval and closing procedure.

Science.gov (United States)

2010-01-01

..., DEPARTMENT OF AGRICULTURE GENERAL POLICIES, TYPES OF LOANS, LOAN REQUIREMENTS-TELECOMMUNICATIONS PROGRAM Requirements for All Acquisitions and Mergers § 1735.94 Final approval and closing procedure. (a) Legal documents relating to the acquisition or merger, including copies of required franchises, commission orders...

Quantization of bosonic closed strings and the Liouville model

International Nuclear Information System (INIS)

Paycha, S.

1988-01-01

The author shows that by means of a reasonable interpretation of the Lebesgue measure describing the partition function the quantization of closed bosonic strings described by compact surfaces of genus p>1 can be related to that of the Liouville model. (HSI)

29 CFR 1209.05 - Closing of meetings; reasons therefor.

Science.gov (United States)

2010-07-01

....05 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD PUBLIC OBSERVATION OF NATIONAL MEDIATION BOARD MEETINGS § 1209.05 Closing of meetings; reasons therefor. (a) Except where the...) (matters specifically exempted from disclosure by statute); (c)(4) (trade secrets and commercial or...

A Three Level Framework for Closed-Loop Supply Chain Management—Linking Society, Chain and Actor Level

Directory of Open Access Journals (Sweden)

Stefan Seuring

2011-04-01

Full Text Available Supply chain management and closed-loop supply chain management (CLSCM have developed into established concepts in recent years. The related material cycles and product returns form an important part of all related processes with high potential for reducing environmental burden. The paper proposes a framework for (environmentally triggered closed-loop supply chain management, spanning three different levels: the societal or governance, the chain and the actor level. Within each level, a set of activities or processes can be identified. Taken together, the levels allow a comprehensive analysis of a closed-loop supply chain system. This is illustrated building on two case studies in the textile and apparel industry, where closed-loop supply chains have been designed to take specific apparel products back. The case studies are analyzed against all three levels and allow exemplification of related challenges and interrelations among the three levels. The three levels contribute to the further comprehension of the multiple issues having to be taken into account for successfully implementing closed-loop supply chains.

Visual perception can account for the close relation between numerosity processing and computational fluency.

Science.gov (United States)

Zhou, Xinlin; Wei, Wei; Zhang, Yiyun; Cui, Jiaxin; Chen, Chuansheng

2015-01-01

Studies have shown that numerosity processing (e.g., comparison of numbers of dots in two dot arrays) is significantly correlated with arithmetic performance. Researchers have attributed this association to the fact that both tasks share magnitude processing. The current investigation tested an alternative hypothesis, which states that visual perceptual ability (as measured by a figure-matching task) can account for the close relation between numerosity processing and arithmetic performance (computational fluency). Four hundred and twenty four third- to fifth-grade children (220 boys and 204 girls, 8.0-11.0 years old; 120 third graders, 146 fourth graders, and 158 fifth graders) were recruited from two schools (one urban and one suburban) in Beijing, China. Six classes were randomly selected from each school, and all students in each selected class participated in the study. All children were given a series of cognitive and mathematical tests, including numerosity comparison, figure matching, forward verbal working memory, visual tracing, non-verbal matrices reasoning, mental rotation, choice reaction time, arithmetic tests and curriculum-based mathematical achievement test. Results showed that figure-matching ability had higher correlations with numerosity processing and computational fluency than did other cognitive factors (e.g., forward verbal working memory, visual tracing, non-verbal matrix reasoning, mental rotation, and choice reaction time). More important, hierarchical multiple regression showed that figure matching ability accounted for the well-established association between numerosity processing and computational fluency. In support of the visual perception hypothesis, the results suggest that visual perceptual ability, rather than magnitude processing, may be the shared component of numerosity processing and arithmetic performance.

Genomic resources for gene discovery, functional genome annotation, and evolutionary studies of maize and its close relatives.

Science.gov (United States)

Wang, Chao; Shi, Xue; Liu, Lin; Li, Haiyan; Ammiraju, Jetty S S; Kudrna, David A; Xiong, Wentao; Wang, Hao; Dai, Zhaozhao; Zheng, Yonglian; Lai, Jinsheng; Jin, Weiwei; Messing, Joachim; Bennetzen, Jeffrey L; Wing, Rod A; Luo, Meizhong

2013-11-01

Maize is one of the most important food crops and a key model for genetics and developmental biology. A genetically anchored and high-quality draft genome sequence of maize inbred B73 has been obtained to serve as a reference sequence. To facilitate evolutionary studies in maize and its close relatives, much like the Oryza Map Alignment Project (OMAP) (www.OMAP.org) bacterial artificial chromosome (BAC) resource did for the rice community, we constructed BAC libraries for maize inbred lines Zheng58, Chang7-2, and Mo17 and maize wild relatives Zea mays ssp. parviglumis and Tripsacum dactyloides. Furthermore, to extend functional genomic studies to maize and sorghum, we also constructed binary BAC (BIBAC) libraries for the maize inbred B73 and the sorghum landrace Nengsi-1. The BAC/BIBAC vectors facilitate transfer of large intact DNA inserts from BAC clones to the BIBAC vector and functional complementation of large DNA fragments. These seven Zea Map Alignment Project (ZMAP) BAC/BIBAC libraries have average insert sizes ranging from 92 to 148 kb, organellar DNA from 0.17 to 2.3%, empty vector rates between 0.35 and 5.56%, and genome equivalents of 4.7- to 8.4-fold. The usefulness of the Parviglumis and Tripsacum BAC libraries was demonstrated by mapping clones to the reference genome. Novel genes and alleles present in these ZMAP libraries can now be used for functional complementation studies and positional or homology-based cloning of genes for translational genomics.

Gustatory sensitivity and food acceptance in two phylogenetically closely related papilionid species: Papilio hospiton and Papilio machaon.

Science.gov (United States)

Sollai, Giorgia; Tomassini Barbarossa, Iole; Masala, Carla; Solari, Paolo; Crnjar, Roberto

2014-01-01

In herbivorous insects, food selection depends on sensitivity to specific chemical stimuli from host-plants as well as to secondary metabolites (bitter) and to sugars (phagostimulatory). Bitter compounds are noxious, unpalatable or both and evoke an aversive feeding response. Instead, sugars and sugar alcohols play a critical role in determining and enhancing the palatability of foods. We assumed that peripheral taste sensitivity may be related to the width of the host selection. Our model consists of two closely phylogenetically related Papilionid species exhibiting a difference in host plant choice: Papilio hospiton and Papilio machaon. The spike activity of the lateral and medial maxillary styloconic taste sensilla was recorded following stimulation with several carbohydrates, nicotine and NaCl, with the aim of characterizing their gustatory receptor neurons and of comparing their response patterns in the light of their different acceptability in feeding behaviour. The results show that: a) each sensillum houses phagostimulant and phagodeterrent cells; b) the spike activity of the gustatory neurons in response to different taste stimuli is higher in P. hospiton than in P. machaon; c) sugar solutions inhibit the spike activity of the deterrent and salt cells, and the suppression is higher in P. machaon than in P. hospiton. In conclusion, we propose that the different balance between the phagostimulant and phagodeterrent inputs from GRNs of maxillary sensilla may contribute in determining the difference in food choice and host range.

Gustatory sensitivity and food acceptance in two phylogenetically closely related papilionid species: Papilio hospiton and Papilio machaon.

Directory of Open Access Journals (Sweden)

Giorgia Sollai

Full Text Available In herbivorous insects, food selection depends on sensitivity to specific chemical stimuli from host-plants as well as to secondary metabolites (bitter and to sugars (phagostimulatory. Bitter compounds are noxious, unpalatable or both and evoke an aversive feeding response. Instead, sugars and sugar alcohols play a critical role in determining and enhancing the palatability of foods. We assumed that peripheral taste sensitivity may be related to the width of the host selection. Our model consists of two closely phylogenetically related Papilionid species exhibiting a difference in host plant choice: Papilio hospiton and Papilio machaon. The spike activity of the lateral and medial maxillary styloconic taste sensilla was recorded following stimulation with several carbohydrates, nicotine and NaCl, with the aim of characterizing their gustatory receptor neurons and of comparing their response patterns in the light of their different acceptability in feeding behaviour. The results show that: a each sensillum houses phagostimulant and phagodeterrent cells; b the spike activity of the gustatory neurons in response to different taste stimuli is higher in P. hospiton than in P. machaon; c sugar solutions inhibit the spike activity of the deterrent and salt cells, and the suppression is higher in P. machaon than in P. hospiton. In conclusion, we propose that the different balance between the phagostimulant and phagodeterrent inputs from GRNs of maxillary sensilla may contribute in determining the difference in food choice and host range.

Closing in on chemical bonds by opening up relativity theory.

Science.gov (United States)

Whitney, Cynthia K

2008-03-01

This paper develops a connection between the phenomenology of chemical bonding and the theory of relativity. Empirical correlations between electron numbers in atoms and chemical bond stabilities in molecules are first reviewed and extended. Quantitative chemical bond strengths are then related to ionization potentials in elements. Striking patterns in ionization potentials are revealed when the data are viewed in an element-independent way, where element-specific details are removed via an appropriate scaling law. The scale factor involved is not explained by quantum mechanics; it is revealed only when one goes back further, to the development of Einstein's special relativity theory.

27 CFR 44.146 - Closing.

Science.gov (United States)

2010-04-01

... PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Operations by Export Warehouse Proprietors Inventories § 44.146 Closing. A closing inventory shall be made by the export warehouse proprietor when he transfers ownership or concludes business. Where the proprietor transfers ownership the closing inventory shall be made...

Biologically Costly Altruism Depends on Emotional Closeness among Step but Not Half or Full Sibling

Directory of Open Access Journals (Sweden)

Paola Bressan

2009-01-01

Full Text Available We studied altruistic behaviors of varying biological cost (high, medium, and low among siblings of varying genetic relatedness (full, half, and step. In agreement with inclusive fitness theory, the relative importance of either reliable (such as co-residence or heuristic (such as emotional closeness kinship cues depended crucially on the costs of help. When help did not endanger the altruist's life, thus making reciprocation possible, emotional closeness was the strongest predictor of altruism; perceived physical and psychological similarity to the sibling amplified altruistic behavior via their association with emotional closeness. When help endangered the altruist's life, thus making reciprocation unlikely, the strongest predictor of altruism was the ancestrally valid kinship cue of co-residence duration. Emotional closeness predicted costly altruism only for step siblings; its effects were nonsignificant when siblings were genetically related. Our findings support the idea that emotional closeness promotes costly altruistic behavior by serving as a surrogate kinship cue when more reliable cues are missing.

Rapid differentiation of closely related isolates of two plant viruses by polymerase chain reaction and restriction fragment length polymorphism analysis.

Science.gov (United States)

Barbara, D J; Morton, A; Spence, N J; Miller, A

1995-09-01

Immunocapture reverse transcriptase-polymerase chain reaction (RT-PCR) followed by restriction fragment length polymorphism (RFLP) analysis of the product has been shown to be an effective procedure for discriminating serologically indistinguishable isolates of two plant viruses, raspberry bushy dwarf (RBDV) and zucchini yellow mosaic (ZYMV). For both viruses, only limited sequence information was available at the time of primer design, but most of the isolates which were tested could be amplified (the one exception being a serologically quite distinct isolate of ZYMV). Restriction endonucleases revealing diagnostic RFLPs were readily identified. Each of two isolates of ZYMV could be detected in the presence of the other and the relative proportions approximately quantified by visual estimation of the relative intensity of the appropriate bands. A range of isolates of different RBDV pathotypes were compared; isolates were grouped in ways that accorded with their known history. Computer analysis of the published sequence from which the primers had been derived showed the sequenced isolate to be identical with an isolate imported from the USSR. The PCR/RFLP procedure is rapid (it can be completed in less than 2 days), effective and will probably be generally applicable to distinguishing closely related virus isolates, even where little sequence information is available.

A simple multistage closed-(box+reservoir model of chemical evolution

Directory of Open Access Journals (Sweden)

Caimmi R.

2011-01-01

Full Text Available Simple closed-box (CB models of chemical evolution are extended on two respects, namely (i simple closed-(box+reservoir (CBR models allowing gas outflow from the box into the reservoir (Hartwick 1976 or gas inflow into the box from the reservoir (Caimmi 2007 with rate proportional to the star formation rate, and (ii simple multistage closed-(box+reservoir (MCBR models allowing different stages of evolution characterized by different inflow or outflow rates. The theoretical differential oxygen abundance distribution (TDOD predicted by the model maintains close to a continuous broken straight line. An application is made where a fictitious sample is built up from two distinct samples of halo stars and taken as representative of the inner Galactic halo. The related empirical differential oxygen abundance distribution (EDOD is represented, to an acceptable extent, as a continuous broken line for two viable [O/H]-[Fe/H] empirical relations. The slopes and the intercepts of the regression lines are determined, and then used as input parameters to MCBR models. Within the errors (-+σ, regression line slopes correspond to a large inflow during the earlier stage of evolution and to low or moderate outflow during the subsequent stages. A possible inner halo - outer (metal-poor bulge connection is also briefly discussed. Quantitative results cannot be considered for applications to the inner Galactic halo, unless selection effects and disk contamination are removed from halo samples, and discrepancies between different oxygen abundance determination methods are explained.

27 CFR 40.426 - Closing.

Science.gov (United States)

2010-04-01

... TOBACCO Manufacture of Cigarette Papers and Tubes Operations by Manufacturers § 40.426 Closing. A closing report, covering the period from the first of the month to the date of the closing inventory, shall be made with such inventory. (72 Stat. 1422; 26 U.S.C. 5722) Inventories ...

7 CFR 1927.56 - Scheduling loan closing.

Science.gov (United States)

2010-01-01

... REGULATIONS TITLE CLEARANCE AND LOAN CLOSING Real Estate Title Clearance and Loan Closing § 1927.56 Scheduling loan closing. The agency, in coordination with the closing agent, will arrange a loan closing and send loan closing instructions, on an agency form to the closing agent when the agency determines that the...

Corrigendum to “Relative humidity effects on water vapour fluxes measured with closed-path eddy-covariance systems with short sampling lines” [Agric. Forest Meteorol. 165 (2012) 53–63

DEFF Research Database (Denmark)

Fratini, Gerardo; Ibrom, Andreas; Arriga, Nicola

2012-01-01

It has been formerly recognised that increasing relative humidity in the sampling line of closed-path eddy-covariance systems leads to increasing attenuation of water vapour turbulent fluctuations, resulting in strong latent heat flux losses. This occurrence has been analyzed for very long (50 m...... from eddy-covariance systems featuring short (4 m) and very short (1 m) sampling lines running at the same clover field and show that relative humidity effects persist also for these setups, and should not be neglected. Starting from the work of Ibrom and co-workers, we propose a mixed method...... and correction method proposed here is deemed applicable to closed-path systems featuring a broad range of sampling lines, and indeed applicable also to passive gases as a special case. The methods described in this paper are incorporated, as processing options, in the free and open-source eddy...

Eyes wide shut: amygdala mediates eyes-closed effect on emotional experience with music.

Science.gov (United States)

Lerner, Yulia; Papo, David; Zhdanov, Andrey; Belozersky, Libi; Hendler, Talma

2009-07-15

The perceived emotional value of stimuli and, as a consequence the subjective emotional experience with them, can be affected by context-dependent styles of processing. Therefore, the investigation of the neural correlates of emotional experience requires accounting for such a variable, a matter of an experimental challenge. Closing the eyes affects the style of attending to auditory stimuli by modifying the perceptual relationship with the environment without changing the stimulus itself. In the current study, we used fMRI to characterize the neural mediators of such modification on the experience of emotionality in music. We assumed that closed eyes position will reveal interplay between different levels of neural processing of emotions. More specifically, we focused on the amygdala as a central node of the limbic system and on its co-activation with the Locus Ceruleus (LC) and Ventral Prefrontal Cortex (VPFC); regions involved in processing of, respectively, 'low', visceral-, and 'high', cognitive-related, values of emotional stimuli. Fifteen healthy subjects listened to negative and neutral music excerpts with eyes closed or open. As expected, behavioral results showed that closing the eyes while listening to emotional music resulted in enhanced rating of emotionality, specifically of negative music. In correspondence, fMRI results showed greater activation in the amygdala when subjects listened to the emotional music with eyes closed relative to eyes open. More so, by using voxel-based correlation and a dynamic causal model analyses we demonstrated that increased amygdala activation to negative music with eyes closed led to increased activations in the LC and VPFC. This finding supports a system-based model of perceived emotionality in which the amygdala has a central role in mediating the effect of context-based processing style by recruiting neural operations involved in both visceral (i.e. 'low') and cognitive (i.e. 'high') related processes of emotions.

Restaurants closed over Christmas

CERN Multimedia

2011-01-01

The restaurants will be closed during the Christmas holiday period : please note that all three CERN Restaurants will be closed from 5 p.m. on Wednesday, 21 December until Wednesday, 4 January inclusive. The Restaurants will reopen on Thursday, 5 January 2012.

Closing-in without severe drawing disorders: the "fatal" consequences of pathological attraction.

Science.gov (United States)

Conson, Massimiliano; Salzano, Sara; Manzo, Valentino; Grossi, Dario; Trojano, Luigi

2009-03-01

The closing-in phenomenon (CIP) is often observed in patients with severe drawing disorders, but its cognitive bases are not well understood. We describe an experimental investigation aimed to clarify the nature of closing-in and its relationships with drawing disorders in a patient with corticobasal degeneration. In copying simple or complex stimuli (Experiment 1), the patient showed adherent and near types of closing-in, not affected by stimulus complexity, and produced distorted and often unrecognisable drawings. On the contrary, in drawing to dictation (without any available model), patients' performances significantly improved with respect to copying (Experiment 2). These data were consistent with the hypothesis that in some patients closing-in may develop from frontal-related release of approach behaviour even in the absence of relevant visuoperceptual impairments. By asking the patient to reproduce given spatial locations within circular frames (Experiment 3), we could further demonstrate the sparing of visuospatial processing and the frontal genesis of closing-in. These findings allowed us to speculate on the heterogeneous nature of closing-in.

Trehalose 6-phosphate signal is closely related to sorbitol in apple (Malus domestica Borkh. cv. Gala

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Wen Zhang

2017-02-01

Full Text Available Trehalose-6-phosphate (Tre6P is a precursor of trehalose, which is widespread in nature and greatly influences plant growth and development. Tre6P acts as a signal of carbon availability in many plants, but little is known about the function of Tre6P in rosaceous plants, which have specific sorbitol biosynthesis and transportation pathways. In the present study, Tre6P levels and Sorbitol:Tre6P ratios were analyzed in apple (Malus domestica, Borkh. cv. Gala. Tre6P levels were positively correlated with sorbitol content but negatively correlated with sucrose, glucose, and fructose content in developing fruit. However, under sorbitol-limited conditions, Tre6P levels were positively correlated with both sorbitol and sucrose. In the presence of different exogenous sugar supply, Tre6P levels increased corresponding with sorbitol, but this was not the case with sucrose. In addition, Tre6P content and sorbitol:Tre6P ratios were more highly correlated with ADP-glucose levels under sorbitol-limited conditions and fruit development stages, respectively. These results suggest that Tre6P is more closely related to sorbitol than other soluble sugars and has an important role in influencing carbon metabolism in apple.

Trehalose 6-phosphate signal is closely related to sorbitol in apple (Malus domestica Borkh. cv. Gala)

Science.gov (United States)

Zhang, Wen; Lunn, John E.; Feil, Regina; Wang, Yufei; Zhao, Jingjing; Tao, Hongxia; Zhao, Zhengyang

2017-01-01

ABSTRACT Trehalose-6-phosphate (Tre6P) is a precursor of trehalose, which is widespread in nature and greatly influences plant growth and development. Tre6P acts as a signal of carbon availability in many plants, but little is known about the function of Tre6P in rosaceous plants, which have specific sorbitol biosynthesis and transportation pathways. In the present study, Tre6P levels and Sorbitol:Tre6P ratios were analyzed in apple (Malus domestica, Borkh. cv. Gala). Tre6P levels were positively correlated with sorbitol content but negatively correlated with sucrose, glucose, and fructose content in developing fruit. However, under sorbitol-limited conditions, Tre6P levels were positively correlated with both sorbitol and sucrose. In the presence of different exogenous sugar supply, Tre6P levels increased corresponding with sorbitol, but this was not the case with sucrose. In addition, Tre6P content and sorbitol:Tre6P ratios were more highly correlated with ADP-glucose levels under sorbitol-limited conditions and fruit development stages, respectively. These results suggest that Tre6P is more closely related to sorbitol than other soluble sugars and has an important role in influencing carbon metabolism in apple. PMID:28069587

The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses

KAUST Repository

Piazza, A.

2015-03-14

Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant\\'s metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant\\'s metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant\\'s resources after infection, but on the other hand, it is a tell-tale sign of the pathogen\\'s presence that triggers the plant to defend itself against infection. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Nucleonics, and nuclear matter in 10{sup {minus}20} secs. before the close of {open_quotes}Big Bang{close_quotes}

Energy Technology Data Exchange (ETDEWEB)

Ayub, S.M.

1995-10-01

The Nuclear picture 10{sup -20} secs. after the thermonuclear creation of the Universe {approximately}8 Billion years ago (as also evidenced by Hubble Telescope) was published. Relativity concepts predict the Nuclear picture l0{sup -20} secs. before the {open_quote}G{close_quote} collapse of the Universe, by the progressive decline of expansion,and H. Constant. No double-nuclei, anymore. Only Neutrinos, as predicted by International Scientists, and fragments of Black Holes. Universe {open_quote}r{close_quote}=60 Billion Light-Years. At the Zero Point, N.Force,and 3 other Forces merging into Super-G. Time, Space, becoming identical, and all Physical Laws vanishing. The final will be Nuclear Matter compact of {approximately} <13Km.> 10Km., {open_quote}r{close_quote}, P=10{sup 15}-10{sup 18} Temp. > 10{sup 10} Deg. C. P> 10{sup 18} will cause another thermonuclear Bang`. Super-computers, also, cannot predict beyond this point. There will be the Creator, and a compact of Nuclear Matter. In the absence of Physical Laws, there can be no further predictability. What initiated by the N. Force, has culminated into a compact of Nuclear Matter- - how interesting!

Tornado type closed magnetic trap for an ECR source

CERN Document Server

Abramova, K B; Voronin, A V; Zorin, V G

1999-01-01

We propose to use a Tornado type closed magnetic trap for creation of a source of mul-ticharged ions with plasma heating by microwave radiation. Plasma loss in closed traps is deter-mined by diffusion across the magnetic field, which increases substantially plasma confinement time as compared to the classical mirror trap [1]. We propose to extract ions with the aid of additional coils which partially destroy the closed structure of the magnetic lines in the trap, but don not influence the total confinement time. This allows for producing a controlled plasma flux that depends on the magnetic field of the additional coil. The Tornado trap also possesses merits such as an opportunity to produce high magnetic fields up to 3 T, which makes possible heating and confinement of plasma with a high density of electrons; plasma stability to magneto-hydrodynamic perturbations because the magnetic field structure corresponds to the "min B" configuration; and relatively low costs. All estimates and calculations were carrie...

HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

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Xiaoping Zhang

2013-12-01

Full Text Available Bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo, is one of the most destructive diseases of rice (Oryza sativa L. worldwide. The type III secretion system (T3SS of Xoo, encoded by the hrp (hypersensitive response and pathogenicity genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response (HR in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation. Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc (hrp-conserved gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99A mutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into

HrcQ is necessary for Xanthomonas oryzae pv. oryzae HR-induction in non-host tobacco and pathogenicity in host rice

Institute of Scientific and Technical Information of China (English)

Xiaoping; Zhang; Chunlian; Wang; Chongke; Zheng; Jinying; Che; Yanqiang; Li; Kaijun; Zhao

2013-01-01

Bacterial blight, caused by Xanthomonas oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice(Oryza sativa L.) worldwide. The type III secretion system(T3SS) of Xoo, encoded by the hrp(hypersensitive response and pathogenicity) genes, plays critical roles in conferring pathogenicity in host rice and triggering a hypersensitive response(HR) in non-host plants. To investigate the major genes conferring the pathogenicity and avirulence of Xoo, we previously constructed a random Tn5-insertion mutant library of Xoo strain PXO99A. We report here the isolation and characterization of a Tn5-insertion mutant PXM69. Tn5-insertion mutants were screened on indica rice JG30, which is highly susceptible to PXO99A, by leaf-cutting inoculation.Four mutants with reduced virulence were obtained after two rounds of screening. Among them, the mutant PXM69 had completely lost virulence to the rice host and ability to elicit HR in non-host tobacco. Southern blotting analysis showed a single copy of a Tn5-insertion in the genome of PXM69. PCR walking and sequencing analysis revealed that the Tn5 transposon was inserted at nucleotide position 70,192–70,201 in the genome of PXO99A, disrupting the type III hrc(hrp-conserved) gene hrcQ, the first gene in the D operon of the hrp cluster in Xoo. To confirm the relationship between the Tn5-insertion and the avirulence phenotype of PXM69, we used the marker exchange mutagenesis to create a PXO99Amutant, ΔhrcQ::KAN, in which the hrcQ was disrupted by a kanamycin-encoding gene cassette at the same site as that of the Tn5-insertion. ΔhrcQ::KAN showed the same phenotype as mutant PXM69. Reintroduction of the wild-type hrcQ gene partially complemented the pathogenic function of PXM69. RT-PCR and cellulase secretion assays showed that the Tn5-disruption of hrcQ did not affect transcription of downstream genes in the D operon and function of the type II secretion system. Our results provide new insights into the pathogenic

Minding the close relationship.

Science.gov (United States)

Harvey, J H; Omarzu, J

1997-01-01

In this theoretical analysis, we argue that a process referred to as minding is essential for a couple to feel mutually close and satisfied in a close relationship over a long period Minding represents a package of mutual self-disclosure, other forms of goal-oriented behavior aimed at facilitating the relationship, and attributions about self's and other's motivations, intentions, and Mort in the relationship. Self-disclosure and attribution activities in minding are aimed at getting to know the other, trying to understand the other's motivations and deeper disposition as they pertain to the relationship, and showing respect and acceptance for knowledge gained about other. We link the concept of minding to other major ideas and literatures about how couples achieve closeness: self-disclosure and social penetration, intimacy, empathy and empathic accuracy, and love and self-expansion. We argue that the minding process articulated here has not previously been delineated and that it is a useful composite notion about essential steps in bonding among humans. We also argue that the minding concept stretches our understanding of the interface of attribution and close relationships. We present research possibilities and implications and consider possible alternative positions and counter arguments about the merits of the minding idea for close relationship satisfaction.

The parametric open-plus-closed-loop control of chaotic maps and its robustness

International Nuclear Information System (INIS)

Chen Liqun

2004-01-01

This paper proposes a parametric open-plus-closed-loop control approach to controlling chaos. The logistic map is treated as an example to demonstrate the application of the proposed approach. It is proved that the approach is robust to the model error. Its relations to the open-plus-closed-loop control and the parametric entrainment control are discussed

Roto-translation motion of the stars in close binary systems

International Nuclear Information System (INIS)

Medvedeva, A A

2013-01-01

This article has to show that the model of p-h which is used to determine the change of the semi major axis of the relative orbit stars is incorrect and leads to large errors in the determination of semi-major axis. The new model, suitable for the elliptical orbits of the stars. To determine relative motion of stars in a close binary system in this paper uses a numerical integration of the equations of motion with the reactive forces, including the rotational component of attraction between the stars and the stream flows into the substance. The calculations of elliptical orbits of close binary stars show that the effect of the reactive force on the evolution of the orbits of stars may be different. The results can be refined by introducing other disturbing factors and making new assumptions based on observations

7 CFR 764.402 - Loan closing.

Science.gov (United States)

2010-01-01

... SPECIAL PROGRAMS DIRECT LOAN MAKING Loan Decision and Closing § 764.402 Loan closing. (a) Signature... information for the Agency to reconfirm approval and proceed with loan closing. (3) The Agency or closing... account will be used according to subpart B of part 761 of this chapter when these processes are not...

The existential function of close relationships: introducing death into the science of love.

Science.gov (United States)

Mikulincer, Mario; Florian, Victor; Hirschberger, Gilad

2003-01-01

Originally, terror management theory proposed two psychological mechanisms in dealing with the terror of death awareness-cultural worldview validation and self-esteem enhancement. In this article, we would like to promote the idea of close relationships as an additional death-anxiety buffering mechanism and review a growing body of empirical data that support this contention. Based on a comprehensive analysis of the sociocultural and personal functions of close relationships, we formulate two basic hypotheses that have received empirical support in a series of experimental studies. First, death reminders heighten the motivation to form and maintain close relationships. Second, the maintenance of close relationships provides a symbolic shield against the terror of death, whereas the breaking of close relationships results in an upsurge of death awareness. In addition, we present empirical evidence supporting the possibility that close relationships function as a related yet separate mechanism from the self-esteem and cultural worldview defenses.

Formation of planetary nebulae with close binary nuclei

Energy Technology Data Exchange (ETDEWEB)

Livio, M; Salzman, J; Shaviv, G [Tel Aviv Univ. (Israel). Dept. of Physics and Astronomy

1979-07-01

A model for the formation of planetary nebulae with a close binary as a nucleus is presented. The model is based on mass loss instability at L/sub 2/. The instability is demonstrated. The conditions on the mass loss are formulated and analysed. The observational consequence of the model is described briefly and its relation to symbiotic stars and cataclysmic binaries discussed.

Burnout and engagement: Identical twins or just close relatives?

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Toon W. Taris

2017-06-01

Full Text Available Past research has frequently cast doubts on the theoretical and empirical distinction between the concepts of work engagement and burnout. Drawing on cross-sectional survey data from 1535 Dutch police officers, the current study examined (a the associations among the two core dimensions of burnout (i.e. exhaustion and cynicism and work engagement (vigor and dedication; and (b the concurrent and discriminant validity of these dimensions by relating these four dimensions to various important job demands and job resources. Confirmatory factor analysis showed that the distinction between burnout and engagement is elusive. Moreover, although the indicators of burnout and those of engagement differed in terms of their job-related correlates, these patterns of associations only partly supported previous theorizing on the antecedents of burnout and engagement. We conclude that burnout and engagement are to a large degree overlapping concepts and that their conceptual and empirical differences should not be overestimated.

Closed string field theory

International Nuclear Information System (INIS)

Strominger, A.

1987-01-01

A gauge invariant cubic action describing bosonic closed string field theory is constructed. The gauge symmetries include local spacetime diffeomorphisms. The conventional closed string spectrum and trilinear couplings are reproduced after spontaneous symmetry breaking. The action S is constructed from the usual ''open string'' field of ghost number minus one half. It is given by the associator of the string field product which is non-vanishing because of associativity anomalies. S does not describe open string propagation because open string states associate and can thereby be shifted away. A field theory of closed and open strings can be obtained by adding to S the cubic open string action. (orig.)

Using SSR-HRM to Identify Closely Related Species in Herbal Medicine Products: A Case Study on Licorice.

Science.gov (United States)

Li, Jingjian; Xiong, Chao; He, Xia; Lu, Zhaocen; Zhang, Xin; Chen, Xiaoyang; Sun, Wei

2018-01-01

Traditional herbal medicines have played important roles in the ways of life of people around the world since ancient times. Despite the advanced medical technology of the modern world, herbal medicines are still used as popular alternatives to synthetic drugs. Due to the increasing demand for herbal medicines, plant species identification has become an important tool to prevent substitution and adulteration. Here we propose a method for biological assessment of the quality of prescribed species in the Chinese Pharmacopoeia by use of high resolution melting (HRM) analysis of microsatellite loci. We tested this method on licorice, a traditional herbal medicine with a long history. Results showed that nine simple sequence repeat (SSR) markers produced distinct melting curve profiles for the five licorice species investigated using HRM analysis. These results were validated by capillary electrophoresis. We applied this protocol to commercially available licorice products, thus enabling the consistent identification of 11 labels with non-declared Glycyrrhiza species. This novel strategy may thus facilitate DNA barcoding as a method of identification of closely related species in herbal medicine products. Based on this study, a brief operating procedure for using the SSR-HRM protocol for herbal authentication is provided.

SRB states and nonequilibrium statistical mechanics close to equilibrium

OpenAIRE

Gallavotti, Giovannni; Ruelle, David

1996-01-01

Nonequilibrium statistical mechanics close to equilibrium is studied using SRB states and a formula for their derivatives with respect to parameters. We write general expressions for the thermodynamic fluxes (or currents) and the transport coefficients, generalizing previous results. In this framework we give a general proof of the Onsager reciprocity relations.

Model for lattice dynamics of hexagonal close packed metals

Energy Technology Data Exchange (ETDEWEB)

Singh, R K [Tata Inst. of Fundamental Research, Bombay (India); Kumar, S [Meerut Coll. (India). Dept. of Physics

1977-11-19

A lattice dynamical model, which satisfies the requirements of translational invariance as well as the static equilibrium of hexagonal close packed lattice, has been proposed and applied to study the phonon dispersion relations in magnesium. The results revealed by this model have been claimed to be better than earlier ones.

Closed-loop Supply Chain as an Agent of Sustainable Development

Directory of Open Access Journals (Sweden)

Shu-San Gan

2015-06-01

Full Text Available Sustainability has recently become an important issue which received growing attentions from government, society, industries as well as academia. There have been concerns on relatively rapid growth in population and increased quality of life despite limited natural resources and landfill capacity. Closed-loop Supply Chain (CLSC is one of many approaches to mitigate the abovementioned disproportion. This article aims to study closed-loop supply chain by explaining the definition, description, pros and contras, relevance, case studies from literature, and potential research; such that its role as an agent of sustainable development can be recognized.

Contribution of rpfB to cell-to-cell signal synthesis, virulence, and vector transmission of Xylella fastidiosa.

Science.gov (United States)

Almeida, Rodrigo P P; Killiny, Nabil; Newman, Karyn L; Chatterjee, Subhadeep; Ionescu, Michael; Lindow, Steven E

2012-04-01

In Xylella fastidiosa the fatty acid signal molecule diffusible signaling factor (DSF) is produced and sensed by components of the regulation of pathogenicity factors (rpf) cluster; lack of DSF production in RpfF mutants results in a non-vector-transmissible phenotype yet cells are hypervirulent to grape. rpfB has not been characterized in Xylella fastidiosa, although its homolog has been suggested to be required for DSF synthesis in Xanthomonas campestris pv. campestris. We show that RpfB is involved in DSF processing in both Xylella fastidiosa and Xanthomonas campestris, affecting the profile of DSF-like fatty acids observed in thin-layer chromatography. Although three fatty acids whose production is dependent on RpfF were detected in Xylella fastidiosa and Xanthomonas campestris wild-type strains, their respective rpfB mutants accumulated primarily one chemical species. Although no quantifiable effect of rpfB on plant colonization by Xylella fastidiosa was found, insect colonization and transmission was reduced. Thus, RpfB apparently is involved in DSF processing, and like Xanthomonas campestris, Xylella fastidiosa also produces multiple DSF molecules. It is possible that Xylella fastidiosa coordinates host vector and plant colonization by varying the proportions of different forms of DSF signals via RpfB.

Operating room fires: a closed claims analysis.

Science.gov (United States)

Mehta, Sonya P; Bhananker, Sanjay M; Posner, Karen L; Domino, Karen B

2013-05-01

To assess patterns of injury and liability associated with operating room (OR) fires, closed malpractice claims in the American Society of Anesthesiologists Closed Claims Database since 1985 were reviewed. All claims related to fires in the OR were compared with nonfire-related surgical anesthesia claims. An analysis of fire-related claims was performed to identify causative factors. There were 103 OR fire claims (1.9% of 5,297 surgical claims). Electrocautery was the ignition source in 90% of fire claims. OR fire claims more frequently involved older outpatients compared with other surgical anesthesia claims (P fire claims (P fires (n = 93) increased over time (P fires occurred during head, neck, or upper chest procedures (high-fire-risk procedures). Oxygen served as the oxidizer in 95% of electrocautery-induced OR fires (84% with open delivery system). Most electrocautery-induced fires (n = 75, 81%) occurred during monitored anesthesia care. Oxygen was administered via an open delivery system in all high-risk procedures during monitored anesthesia care. In contrast, alcohol-containing prep solutions and volatile compounds were present in only 15% of OR fires during monitored anesthesia care. Electrocautery-induced fires during monitored anesthesia care were the most common cause of OR fires claims. Recognition of the fire triad (oxidizer, fuel, and ignition source), particularly the critical role of supplemental oxygen by an open delivery system during use of the electrocautery, is crucial to prevent OR fires. Continuing education and communication among OR personnel along with fire prevention protocols in high-fire-risk procedures may reduce the occurrence of OR fires.

The role of horizontal transfer in the evolution of a highly variable lipopolysaccharide biosynthesis locus in xanthomonads that infect rice, citrus and crucifers

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Bogdanove Adam J

2007-12-01

Full Text Available Abstract Background Lipopolysaccharide (LPS is a pathogen associated molecular pattern (PAMP of animal and plant pathogenic bacteria. Variation at the interstrain level is common in LPS biosynthetic gene clusters of animal pathogenic bacteria. This variation has been proposed to play a role in evading the host immune system. Even though LPS is a modulator of plant defense responses, reports of interstrain variation in LPS gene clusters of plant pathogenic bacteria are rare. Results In this study we report the complete sequence of a variant 19.9 kb LPS locus present in the BXO8 strain of Xanthomonas oryzae pv. oryzae (Xoo, the bacterial blight pathogen of rice. This region is completely different in size, number and organization of genes from the LPS locus present in most other strains of Xoo from India and Asia. Surprisingly, except for one ORF, all the other ORFs at the BXO8 LPS locus are orthologous to the genes present at this locus in a sequenced strain of X. axonopodis pv. citri (Xac; a pathogen of citrus plants. One end of the BXO8 LPS gene cluster, comprised of ten genes, is also present in the related rice pathogen, X. oryzae pv. oryzicola (Xoc. In Xoc, the remainder of the LPS gene cluster, consisting of seven genes, is novel and unrelated to LPS gene clusters of any of the sequenced xanthomonads. We also report substantial interstrain variation suggestive of very recent horizontal gene transfer (HGT at the LPS biosynthetic locus of Xanthomonas campestris pv. campestris (Xcc, the black rot pathogen of crucifers. Conclusion Our analyses indicate that HGT has altered the LPS locus during the evolution of Xanthomonas oryzae pathovars and suggest that the ancestor of all Xanthomonas oryzae pathovars had an Xac type of LPS gene cluster. Our finding of interstrain variation in two major xanthomonad pathogens infecting different hosts suggests that the LPS locus in plant pathogenic bacteria, as in animal pathogens, is under intense

Different strategies of osmoadaptation in the closely related marine myxobacteria Enhygromyxa salina SWB007 and Plesiocystis pacifica SIR-1.

Science.gov (United States)

Amiri Moghaddam, Jamshid; Boehringer, Nils; Burdziak, Amal; Kunte, Hans-Jörg; Galinski, Erwin A; Schäberle, Till F

2016-02-03

Only a few myxobacteria are known to date which are classified as marine due to their salt-dependency. In this study, the salt tolerance mechanism of these bacteria was investigated. Therefore, a growth medium was designed, in which the mutated Escherichia coli strain BKA13 served as sole food source for the predatory, heterotrophic myxobacteria. This enabled measurement of the osmolytes without any background and revealed that the closely related strains Enhygromyxa salina SWB007 and Plesiocystis pacifica SIR-1 developed different strategies to handle salt stress. P. pacifica SIR-1, which was grown between 1-4 % NaCl, relies solely on the accumulation of amino acids, while E. salina SWB007, which was grown between 0.5-3 % NaCl, employs, beside betaine, hydroxyectoine as the major compatible solute. In accordance with this analysis, only in the latter strain a gene locus was identified which codes for genes corresponding to the biosynthesis of betaine, ectoine, and hydroxyectoine.