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Sample records for repeated ixodes scapularis

  1. Pathogenicity of entomopathogenic fungus Metarhizium anisopliae (Deuteromycetes) to Ixodes scapularis (Acari: Ixodidae)

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    Zhioua, E.; Browning, M.; Johnson, P.W.; Ginsberg, H.S.; LeBrun, R.A.

    1997-01-01

    The entomopathogenic fungus Metarhizium anisopliae is highly pathogenic to the black-legged tick, Ixodes scapularis. Spore concentrations of 108/ml for engorged larvae and 107/ml for engorged females resulted in 100% tick mortality, 2 wk post-infection. The LC50 value for engorged larvae (concentration to kill 50% of ticks) was 107 spores/ml. Metarhizium anisopliae shows considerable potential as a microbial control agent for the management of Ixodes scapularis.

  2. Identification and characterization of Ixodes scapularis antigens that elicit tick immunity using yeast surface display.

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    Tim J Schuijt

    2011-01-01

    Full Text Available Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary antigens that react with tick-immune serum. We constructed an Ixodes scapularis nymphal salivary gland yeast surface display library and screened the library with nymph-immune rabbit sera and identified five salivary antigens. Four of these proteins, designated P8, P19, P23 and P32, had a predicted signal sequence. We generated recombinant (r P8, P19 and P23 in a Drosophila expression system for functional and immunization studies. rP8 showed anti-complement activity and rP23 demonstrated anti-coagulant activity. Ixodes scapularis feeding was significantly impaired when nymphs were fed on rabbits immunized with a cocktail of rP8, rP19 and rP23, a hall mark of tick-immunity. These studies also suggest that these antigens may serve as potential vaccine candidates to thwart tick feeding.

  3. Molecular characterization of novel sulfotransferases from the tick, Ixodes scapularis

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    King Roberta S

    2011-06-01

    Full Text Available Abstract Background Ixodes scapularis, commonly known as the blacklegged or deer tick, is the main vector of Lyme disease in the United States. Recent progress in transcriptome research has uncovered hundreds of different proteins expressed in the salivary glands of hard ticks, the majority of which have no known function, and include many novel protein families. We recently identified transcripts coding for two putative cytosolic sulfotransferases in these ticks which recognized phenolic monoamines as their substrates. In this current study, we characterize the genetic expression of these two cytosolic sulfotransferases throughout the tick life cycle as well as the enzymatic properties of the corresponding recombinant proteins. Interestingly, the resultant recombinant proteins showed sulfotransferase activity against both neurotransmitters dopamine and octopamine. Results The two sulfotransferase genes were coded as Ixosc SULT 1 & 2 and corresponding proteins were referred as Ixosc Sult 1 and 2. Using gene-specific primers, the sulfotransferase transcripts were detected throughout the blacklegged tick life cycle, including eggs, larvae, nymphs, adult salivary glands and adult midgut. Notably, the mRNA and protein levels were altered upon feeding during both the larval and nymphal life stages. Quantitative PCR results confirm that Ixosc SULT1 was statistically increased upon blood feeding while Ixosc SULT 2 was decreased. This altered expression led us to further characterize the function of these proteins in the Ixodid tick. The sulfotransferase genes were cloned and expressed in a bacterial expression system, and purified recombinant proteins Ixosc Sult 1(R and 2(R showed sulfotransferase activity against neurotransmitters dopamine and octopamine as well as the common sulfotransferase substrate p-nitrophenol. Thus, dopamine- or octopamine-sulfonation may be involved in altering the biological signal for salivary secretion in I. scapularis

  4. Relative humidity and activity patterns of Ixodes scapularis (Acari: Ixodidae)

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    Berger, K.A.; Ginsberg, Howard S.; Gonzalez, L.; Mather, T.N.

    2014-01-01

    Laboratory studies have shown clear relationships between relative humidity (RH) and the activity and survival of Ixodes scapularis Say (blacklegged tick). However, field studies have produced conflicting results. We examined this relationship using weekly tick count totals and hourly RH observations at three field sites, stratified by latitude, within the state of Rhode Island. Records of nymphal tick abundance were compared with several RH-related variables (e.g., RH at time of sampling and mean weekly daytime RH). In total, 825 nymphs were sampled in 2009, a year of greater precipitation, with a weighted average leaf litter RH recorded at time of sampling of 85.22%. Alternatively, 649 nymphs were collected in 2010, a year of relatively low precipitation, and a weighted average RH recorded at time of sampling was 75.51%. Negative binomial regression analysis of tick count totals identified cumulative hours <82% RH threshold as a significant factor observed in both years (2009: P = 0.0037; 2010: P < 0.0001). Mean weekly daytime RH did not significantly predict tick activity in either year. However, mean weekly daytime RH recorded with 1-wk lag before sample date was a significant variable (P = 0.0016) in 2010. These results suggest a lag effect between moisture availability and patterns of tick activity and abundance. Differences in the relative importance of each RH variable between years may have been due to abnormally wet summer conditions in 2009.

  5. Anaplasma phagocytophilum Infection Subverts Carbohydrate Metabolic Pathways in the Tick Vector, Ixodes scapularis

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

    2017-01-01

    Roč. 7, 7 February (2017), č. článku 23. ISSN 2235-2988 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * glucose metabolism * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

  6. Ixodes scapularis Tick Cells Control Anaplasma phagocytophilum Infection by Increasing the Synthesis of Phosphoenolpyruvate from Tyrosine

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; Espinosa, P. J.; Obregon, D. A.; Alberdi, P.; de la Fuente, J.

    2017-01-01

    Roč. 7, AUG 17 (2017), č. článku 375. ISSN 2235-2988 Institutional support: RVO:60077344 Keywords : proteomics * transcriptomics * phosphoenolpyruvate * glycerol-3-phosphate * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.300, year: 2016

  7. Ixodes scapularis saliva mitigates inflammatory cytokine secretion during Anaplasma phagocytophilum stimulation of immune cells

    Czech Academy of Sciences Publication Activity Database

    Chen, G.; Severo, M. S.; Sohail, M.; Sakhon, O. S.; Wikel, S. K.; Kotsyfakis, Michalis; Pedra, J. H. F.

    2012-01-01

    Roč. 5, č. 1 (2012), s. 229 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Tick * Ixodes scapularis * Saliva * Anaplasma phagocytophilum * Rickettsial agent Subject RIV: EC - Immunology Impact factor: 3.246, year: 2012 http://www.parasitesandvectors.com/content/5/1/229

  8. Efficacy of granular deltamethrin against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidade) nymphs.

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    Schulze, T L; Jordan, R A; Hung, R W; Taylor, R C; Markowski, D; Chomsky, M S

    2001-03-01

    A single barrier application of granular deltamethrin to the woodland edges of a forested residential community in late spring significantly reduced the abundance of Ixodes scapularis Say nymphs. The application also suppressed the population of Amblyomma americanum (L.) nymphs, which recently became established in the study area. The efficacy of deltamethrin is compared with other commonly used acaricides.

  9. Modeling the geographic distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the contiguous United States

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    Hahn, Micah; Jarnevich, Catherine S.; Monaghan, Andrew J.; Eisen, Rebecca J.

    2016-01-01

    In addition to serving as vectors of several other human pathogens, the black-legged tick, Ixodes scapularis Say, and western black-legged tick, Ixodes pacificus Cooley and Kohls, are the primary vectors of the spirochete (Borrelia burgdorferi ) that causes Lyme disease, the most common vector-borne disease in the United States. Over the past two decades, the geographic range of I. pacificus has changed modestly while, in contrast, the I. scapularis range has expanded substantially, which likely contributes to the concurrent expansion in the distribution of human Lyme disease cases in the Northeastern, North-Central and Mid-Atlantic states. Identifying counties that contain suitable habitat for these ticks that have not yet reported established vector populations can aid in targeting limited vector surveillance resources to areas where tick invasion and potential human risk are likely to occur. We used county-level vector distribution information and ensemble modeling to map the potential distribution of I. scapularis and I. pacificus in the contiguous United States as a function of climate, elevation, and forest cover. Results show that I. pacificus is currently present within much of the range classified by our model as suitable for establishment. In contrast, environmental conditions are suitable for I. scapularis to continue expanding its range into northwestern Minnesota, central and northern Michigan, within the Ohio River Valley, and inland from the southeastern and Gulf coasts. Overall, our ensemble models show suitable habitat for I. scapularis in 441 eastern counties and for I. pacificus in 11 western counties where surveillance records have not yet supported classification of the counties as established.

  10. Pathogenicity of Metarhizium anisopliae (Deuteromycetes) and permethrin to Ixodes scapularis (Acari: Ixodidae) nymphs

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    Hornbostel, V.L.; Zhioua, Elyes; Benjamin, Michael A.; Ginsberg, Howard S.; Ostfeld, Richard S.

    2005-01-01

    Effectiveness of the entomopathogenic fungus Metarhizium anisopliae, for controlling nymphal Ixodes scapularis, was tested in laboratory and field trials. In the laboratory, M. anisopliae (Metschnikoff) Sorokin strain ESC1 was moderately pathogenic, with an LC50 of 107 spores/ml and induced 70% mortality at 109 spores/ml. In a field study, however, 109 spores/ml M. anisopliae did not effectively control questing I. scapularis nymphs, and significant differences were not detected in pre- and post-treatment densities. For nymphs collected and returned to the laboratory for observation, mortality was low in treatment groups, ranging from 20 to 36%. To assess whether a chemical acaricide would synergistically enhance pathogenicity of the fungus, we challenged unfed nymphal I. scapularis with combinations of M. anisopliae and permethrin, a relatively safe pyrethroid acaricide, in two separate bioassays. Significant interactions between M. anisopliae and permethrin were not observed, supporting neither synergism nor antagonism.

  11. Genomic insights into the Ixodes scapularis tick vector of Lyme disease

    DEFF Research Database (Denmark)

    Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.

    2016-01-01

    Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects...... proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent....

  12. Water absorption through salivary gland type I acini in the blacklegged tick, Ixodes scapularis

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    Donghun Kim

    2017-10-01

    Full Text Available Tick salivary glands play critical roles in maintaining water balance for survival, as they eliminate excess water and ions during blood feeding on hosts. In the long duration of fasting in the off-host period, ticks secrete hygroscopic saliva into the mouth cavity to uptake atmospheric water vapor. Type I acini of tick salivary glands are speculated to be involved in secretion of hygroscopic saliva based on ultrastructure studies. However, we recently proposed that type I acini play a role in resorption of water/ions from the primary saliva produced by other salivary acini (i.e., types II and III during the tick blood feeding phase. In this study, we tested the function of type I acini in unfed female Ixodes scapularis. The route of ingested water was tracked after forced feeding of water with fluorescent dye rhodamine123. We found that type-I acini of the salivary glands, but not type II and III, are responsible for water uptake. In addition, the ingestion of water through the midgut was also observed. Injection or feeding of ouabain, a Na/K-ATPase inhibitor, suppressed water absorption in type I acini. When I. scapularis was offered a droplet of water, ticks rarely imbibed water directly (5%, while some approached the water droplet to use the high humidity formed in the vicinity of the droplet (23%. We conclude that during both on- and off-host stages, type I acini in salivary glands of female Ixodes scapularis absorb water and ions.

  13. Susceptibility of Four Tick Species Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus (Acari: Ixodidae) to Nootkatone

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    The essential oil nootkatone has shown acaricidal activity on ticks. The toxicity of nootkatone was determined in laboratory assays using a vial coating technique against unfed nymphs of four Ixodid ticks: Amblyomma americanum L., Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicepha...

  14. The role of Ixodes scapularis, Borrelia burgdorferi and wildlife hosts in Lyme disease prevalence: A quantitative review.

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    Halsey, Samniqueka J; Allan, Brian F; Miller, James R

    2018-04-16

    Due to the ongoing expansion of Ixodes scapularis (blacklegged tick) throughout the northeastern and midwestern United States, there is need to identify the role wildlife hosts play in the establishment and maintenance of tick populations. To quantify and synthesize the patterns of I. scapularis and Borrelia burgdorferi sensu stricto and sensu lato prevalence relative to wildlife hosts, we reviewed the findings of independent studies conducted throughout the United States. We performed a comprehensive literature search from 1970 to 2017 using the ISS Web of Science Core Collection and the keywords "Ixodes scapularis," "Ixodes dammini" and "Borrelia burgdorferi." We identified 116 studies for inclusion in our meta-analysis, with 187,414 individual wildlife hosts captured and examined for I. scapularis and either the host or ticks collected subsequently tested for B. burgdorferi. We found that only 13% of the wildlife mammals sampled comprised species other than Odocoileus virginianus (white-tailed deer) and Peromyscus leucopus (white-footed mouse). To examine whether there were regional differences between the Northeast, Midwest and the Southeast U.S. in I. scapularis infestation rates on wildlife hosts, we used general linear models (glm), with post hoc pairwise comparisons. In most cases, detection of I. scapularis and B. burgdorferi was significantly higher in the Northeast than the Midwest. Using data on host-specific I. scapularis infestation prevalence, B. burgdorferi prevalence in feeding larvae, and host permissiveness, we developed an epizootiological model to determine the relative contributions of individual hosts to B. burgdorferi-infected nymphs. Our model provides additional evidence that wildlife hosts other than P. leucopus may contribute more to Lyme disease risk than commonly thought. To aid in understanding the ecology of Lyme disease, we propose that additional studies sample non-Peromyscus spp. hosts to obtain more detailed tick and pathogen

  15. Expansion of the Lyme Disease Vector Ixodes scapularis in Canada inferred from CMIP5 Climate Projections

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    McPherson, Michelle Yvonne; García-García, Almudena; José Cuesta-Valero, Francisco; Beltrami, Hugo; Hansen-Ketchum, Patti; MacDougall, Donna; Hume Ogden, Nicholas

    2017-04-01

    A number of studies have assessed possible climate change impacts on the Lyme disease vector, Ixodes scapularis. However, most have used surface air temperature from only one climate model simulation and/or one emission scenario, representing only one possible climate future. We quantified effects of different Representative Concentration Pathway (RCP) and climate model outputs on the projected future changes in the basic reproduction number (R0) of I. scapularis to explore uncertainties in future R0 estimates. We used surface air temperature generated by a complete set of General Circulation Models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) to hindcast historical and forecast future effects of climate change on the R0 of I. scapularis. As in previous studies, R0 of I. scapularis increased with a warming climate under future projected climate. Increases in the multi-model mean R0 values showed significant changes over time under all RCP scenarios, however; only the estimated R0 mean values between RCP6.0 and RCP8.5 showed statistically significant differences. Our results highlight the potential for climate change to have an effect on future Lyme disease risk in Canada even if the Paris Agreement's goal to keep global warming below 2°C is achieved, although mitigation reducing emissions from RCP8.5 levels to those of RCP6.0 or less would be expected to slow tick invasion after the 2030s. On-going planning is needed to inform and guide adaptation in light of the projected range of possible futures.

  16. Reciprocal Regulation of NF-kB (Relish) and Subolesin in the Tick Vector, Ixodes scapularis

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    Galindo, Ruth C.; Kocan, Katherine M.; Blouin, Edmour F.; Mitra, Ruchira; Alberdi, Pilar; Villar, Margarita; de la Fuente, José

    2013-01-01

    Background Tick Subolesin and its ortholog in insects and vertebrates, Akirin, have been suggested to play a role in the immune response through regulation of nuclear factor-kappa B (NF-kB)-dependent and independent gene expression via interaction with intermediate proteins that interact with NF-kB and other regulatory proteins, bind DNA or remodel chromatin to regulate gene expression. The objective of this study was to characterize the structure and regulation of subolesin in Ixodes scapularis. I. scapularis is a vector of emerging pathogens such as Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti that cause in humans Lyme disease, anaplasmosis and babesiosis, respectively. The genome of I. scapularis was recently sequenced, and this tick serves as a model organism for the study of vector-host-pathogen interactions. However, basic biological questions such as gene organization and regulation are largely unknown in ticks and other arthropod vectors. Principal Findings The results presented here provide evidence that subolesin/akirin are evolutionarily conserved at several levels (primary sequence, gene organization and function), thus supporting their crucial biological function in metazoans. These results showed that NF-kB (Relish) is involved in the regulation of subolesin expression in ticks, suggesting that as in other organisms, different NF-kB integral subunits and/or unknown interacting proteins regulate the specificity of the NF-kB-mediated gene expression. These results suggested a regulatory network involving cross-regulation between NF-kB (Relish) and Subolesin and Subolesin auto-regulation with possible implications in tick immune response to bacterial infection. Significance These results advance our understanding of gene organization and regulation in I. scapularis and have important implications for arthropod vectors genetics and immunology highlighting the possible role of NF-kB and Subolesin/Akirin in vector

  17. An Assessment for the Presence of Powassan Virus in Ixodes scapularis Nymphs from Locations in Virginia, Maryland, New Jersey, Pennsylvania, New York, and Connecticut

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    2013-03-21

    1214-7 46. Kislenko GS, Chunikhin SP, Rasnitsyn SP, Kurenkov VB, Izotov VK. 1982. [Reproduction of Powassan and West Nile viruses in Aedes aegypti ...Ixodes scapularis (Say 1821), an aggressive tick that readily bites humans. This study collected I. scapularis from sites along the U.S. East Coast...68 Appendix 3: Sampling times and collection rates (Ticks

  18. Repellent activity of fractioned compounds from Chamaecyparis nootkatensis essential oil against nymphal Ixodes scapularis (Acari: Ixodidae).

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    Dietrich, Gabrielle; Dolan, Marc C; Peralta-Cruz, Javier; Schmidt, Jason; Piesman, Joseph; Eisen, Rebecca J; Karchesy, Joseph J

    2006-09-01

    Preliminary repellent activity of 14 natural products isolated from essential oil components extracted from the heartwood of Alaska yellow cedar, Chamaecyparis nootkatensis (D. Don) Spach., were evaluated against nymphal Ixodes scapularis Say in a laboratory bioassay and compared with technical grade N,N-diethyl-3-methylbenzamide (deet). Four hours after treatment, nootkatone and valencene-13-ol had repellent concentration (RC)50 values of 0.0458 and 0.0712% (wt:vol), respectively; two additional Alaska yellow cedar compounds, nootkatone 1 --> 10 epoxide and carvacrol had reported RC50 values of 0.0858 and 0.112%, respectively. The observed RC50 value for deet was 0.0728% (wt:vol). Although not statistically significantly more active than deet, the ability of these natural products to repel ticks at relatively low concentrations may represent a potential alternative to synthetic commercial repellents.

  19. Immunity against Ixodes scapularis salivary proteins expressed within 24 hours of attachment thwarts tick feeding and impairs Borrelia transmission.

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    Sukanya Narasimhan

    2007-05-01

    Full Text Available In North America, the black-legged tick, Ixodes scapularis, an obligate haematophagus arthropod, is a vector of several human pathogens including Borrelia burgdorferi, the Lyme disease agent. In this report, we show that the tick salivary gland transcriptome and proteome is dynamic and changes during the process of engorgement. We demonstrate, using a guinea pig model of I. scapularis feeding and B. burgdorferi transmission, that immunity directed against salivary proteins expressed in the first 24 h of tick attachment - and not later - is sufficient to evoke all the hallmarks of acquired tick-immunity, to thwart tick feeding and also to impair Borrelia transmission. Defining this subset of proteins will promote a mechanistic understanding of novel I. scapularis proteins critical for the initiation of tick feeding and for Borrelia transmission.

  20. Defensins from the tick Ixodes scapularis are effective against phytopathogenic fungi and the human bacterial pathogen Listeria grayi

    Czech Academy of Sciences Publication Activity Database

    Tonk, Miray; Cabezas-Cruz, A.; Valdés, James J.; Rego, Ryan O. M.; Chrudimská, Tereza; Strnad, Martin; Šíma, Radek; Bell-Sakyi, L.; Franta, Z.; Vilcinskas, A.; Grubhoffer, Libor; Rahnamaeian, M.

    2014-01-01

    Roč. 7, DEC 3 2015 (2014), s. 554 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA MŠk(CZ) EE2.3.30.0032; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : Antimicrobial peptide * Defensin * Listeria grayi * Fusarium spp * Ixodes scapularis * Tick cell line Subject RIV: EE - Microbiology, Virology Impact factor: 3.430, year: 2014

  1. Efficacy of Plant-Derived and Synthetic Compounds on Clothing as Repellents Against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae)

    Science.gov (United States)

    2012-01-01

    efÞcacy of the repellent deet against Aedes aegypti . J. Am. Mosq. Control Assoc. 14: 178Ð182. Robbins, P. J., and M. G. Cherniack. 1986. Review of...number of reported Lyme disease cases reached an all- time high of35,000 in 2008 (CDC 2010). The blacklegged tick, Ixodes scapularis Say, the principal...Paddock 2003, Mixson et al. 2006, Apperson et al. 2008). Repellents remain the primary method of personal protection against tick bites (Piesman and

  2. Prevalence of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in Ixodes scapularis (Acari: Ixodidae) adults in New Jersey, 2000-2001.

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    Schulze, Terry L; Jordan, Robert A; Hung, Robert W; Puelle, Rose S; Markowski, Daniel; Chomsky, Martin S

    2003-07-01

    Using polymerase chain reaction, we analyzed 529 Ixodes scapularis Say adults collected from 16 of New Jersey's 21 counties for the presence of Borrelia burgdorferi, the etiological agent of Lyme disease. Overall, 261 (49.3%) were positive. B. burgdorferi was detected in ticks obtained from each county and from 53 of the 58 (93.1%) municipalities surveyed. The observed statewide prevalence in New Jersey is similar to those reported from other northeastern and mid-Atlantic states.

  3. Tissue-specific signatures in the transcriptional response to Anaplasma phagocytophilum infection of Ixodes scapularis and Ixodes ricinus tick cell lines

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    Pilar eAlberdi

    2016-02-01

    Full Text Available Anaplasma phagocytophilum are transmitted by Ixodes spp. ticks and have become one of the most common and relevant tick-borne pathogens due to their impact on human and animal health. Recent results have increased our understanding of the molecular interactions between Ixodes scapularis and A. phagocytophilum through the demonstration of tissue-specific molecular pathways that ensure pathogen infection, development and transmission by ticks. However, little is known about the Ixodes ricinus genes and proteins involved in the response to A. phagocytophilum infection. The tick species I. scapularis and I. ricinus are evolutionarily closely related and therefore similar responses are expected in A. phagocytophilum-infected cells. However, differences may exist between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cells associated with tissue-specific signatures of these cell lines. To address this hypothesis, the transcriptional response to A. phagocytophilum infection was characterized by RNA sequencing and compared between I. scapularis ISE6 and I. ricinus IRE/CTVM20 tick cell lines. The transcriptional response to infection of I. scapularis ISE6 cells resembled that of tick hemocytes while the response in I. ricinus IRE/CTVM20 cells was more closely related to that reported previously in infected tick midguts. The inhibition of cell apoptosis by A. phagocytophilum appears to be a key adaptation mechanism to facilitate infection of both vertebrate and tick cells and was used to investigate further the tissue-specific response of tick cell lines to pathogen infection. The results supported a role for the intrinsic pathway in the inhibition of cell apoptosis by A. phagocytophilum infection of I. scapularis ISE6 cells. In contrast, the results in I. ricinus IRE/CTVM20 cells were similar to those obtained in tick midguts and suggested a role for the JAK/STAT pathway in the inhibition of apoptosis in tick cells infected with A. phagocytophilum

  4. Efficacy of plant-derived and synthetic compounds on clothing as repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

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    Jordan, Robert A; Schulze, Terry L; Dolan, Marc C

    2012-01-01

    We conducted field trials to compare the relative repellent activity of two natural product compounds (nootkatone and carvacrol) with commercially available plant-derived (EcoSMART organic insect repellent) and permethrin-based (Repel Permanone) repellents against adult Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) by using treated coveralls. One day after treatment, nootkatone and carvacrol provided 100% repellency of I. scapularis adults, with nootkatone maintaining complete protection through 3 d, whereas carvacrol showed steadily declining repellency against I. scapularis during the 7-d course of the trials. Nootkatone was at least as effective against host-seeking A. americanum as against I. scapularis through 3 d. Carvacrol provided little protection against A. americanum adults. Both natural compounds performed well initially in comparison with the commercial products. After 7 d, nootkatone was the most effective against both species followed in order of activity by Permanone, EcoSMART, and carvacrol. Nootkatone seems to have offer considerable potential as a clothing repellent against both I. scapularis and A. americanum.

  5. Ixodes scapularis tick serine proteinase inhibitor (serpin gene family; annotation and transcriptional analysis

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    Chalaire Katelyn C

    2009-05-01

    Full Text Available Abstract Background Serine proteinase inhibitors (Serpins are a large superfamily of structurally related, but functionally diverse proteins that control essential proteolytic pathways in most branches of life. Given their importance in the biology of many organisms, the concept that ticks might utilize serpins to evade host defenses and immunizing against or disrupting their functions as targets for tick control is an appealing option. Results A sequence homology search strategy has allowed us to identify at least 45 tick serpin genes in the Ixodes scapularis genome that are structurally segregated into 32 intronless and 13 intron-containing genes. Nine of the intron-containing serpins occur in a cluster of 11 genes that span 170 kb of DNA sequence. Based on consensus amino acid residues in the reactive center loop (RCL and signal peptide scanning, 93% are putatively inhibitory while 82% are putatively extracellular. Among the 11 different amino acid residues that are predicted at the P1 sites, 16 sequences possess basic amino acid (R/K residues. Temporal and spatial expression analyses revealed that 40 of the 45 serpins are differentially expressed in salivary glands (SG and/or midguts (MG of unfed and partially fed ticks. Ten of the 38 serpin genes were expressed from six to 24 hrs of feeding while six and fives genes each are predominantly or exclusively expressed in either MG and SG respectively. Conclusion Given the diversity among tick species, sizes of tick serpin families are likely to be variable. However this study provides insight on the potential sizes of serpin protein families in ticks. Ticks must overcome inflammation, complement activation and blood coagulation to complete feeding. Since these pathways are regulated by serpins that have basic residues at their P1 sites, we speculate that I. scapularis may utilize some of the serpins reported in this study to manipulate host defense. We have discussed our data in the context of

  6. Genomic insights into the Ixodes scapularis tick vector of Lyme disease

    Science.gov (United States)

    Gulia-Nuss, Monika; Nuss, Andrew B.; Meyer, Jason M.; Sonenshine, Daniel E.; Roe, R. Michael; Waterhouse, Robert M.; Sattelle, David B.; de la Fuente, José; Ribeiro, Jose M.; Megy, Karine; Thimmapuram, Jyothi; Miller, Jason R.; Walenz, Brian P.; Koren, Sergey; Hostetler, Jessica B.; Thiagarajan, Mathangi; Joardar, Vinita S.; Hannick, Linda I.; Bidwell, Shelby; Hammond, Martin P.; Young, Sarah; Zeng, Qiandong; Abrudan, Jenica L.; Almeida, Francisca C.; Ayllón, Nieves; Bhide, Ketaki; Bissinger, Brooke W.; Bonzon-Kulichenko, Elena; Buckingham, Steven D.; Caffrey, Daniel R.; Caimano, Melissa J.; Croset, Vincent; Driscoll, Timothy; Gilbert, Don; Gillespie, Joseph J.; Giraldo-Calderón, Gloria I.; Grabowski, Jeffrey M.; Jiang, David; Khalil, Sayed M. S.; Kim, Donghun; Kocan, Katherine M.; Koči, Juraj; Kuhn, Richard J.; Kurtti, Timothy J.; Lees, Kristin; Lang, Emma G.; Kennedy, Ryan C.; Kwon, Hyeogsun; Perera, Rushika; Qi, Yumin; Radolf, Justin D.; Sakamoto, Joyce M.; Sánchez-Gracia, Alejandro; Severo, Maiara S.; Silverman, Neal; Šimo, Ladislav; Tojo, Marta; Tornador, Cristian; Van Zee, Janice P.; Vázquez, Jesús; Vieira, Filipe G.; Villar, Margarita; Wespiser, Adam R.; Yang, Yunlong; Zhu, Jiwei; Arensburger, Peter; Pietrantonio, Patricia V.; Barker, Stephen C.; Shao, Renfu; Zdobnov, Evgeny M.; Hauser, Frank; Grimmelikhuijzen, Cornelis J. P.; Park, Yoonseong; Rozas, Julio; Benton, Richard; Pedra, Joao H. F.; Nelson, David R.; Unger, Maria F.; Tubio, Jose M. C.; Tu, Zhijian; Robertson, Hugh M.; Shumway, Martin; Sutton, Granger; Wortman, Jennifer R.; Lawson, Daniel; Wikel, Stephen K.; Nene, Vishvanath M.; Fraser, Claire M.; Collins, Frank H.; Birren, Bruce; Nelson, Karen E.; Caler, Elisabet; Hill, Catherine A.

    2016-01-01

    Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick–host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host ‘questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent. PMID:26856261

  7. A Risk Model for the Lyme Disease Vector Ixodes scapularis (Acari: Ixodidae) in the Prairie Provinces of Canada.

    Science.gov (United States)

    Gabriele-Rivet, Vanessa; Koffi, Jules K; Pelcat, Yann; Arsenault, Julie; Cheng, Angela; Lindsay, L Robbin; Lysyk, Timothy J; Rochon, Kateryn; Ogden, Nicholas H

    2017-07-01

    Lyme disease is emerging in Canada due to geographic range expansion of the tick vector Ixodes scapularis Say. Recent areas of emergence include parts of the southeastern Canadian Prairie region. We developed a map of potential risk areas for future I. scapularis establishment in the Canadian Prairie Provinces. Six I. scapularis risk algorithms were developed using different formulations of three indices for environmental suitability: temperature using annual cumulative degree-days > 0 °C (DD > 0 °C; obtained from Moderate Resolution Imaging Spectroradiometer satellite data as an index of conditions that allow I. scapularis to complete its life cycle), habitat as a combined geolayer of forest cover and agricultural land use, and rainfall. The relative performance of these risk algorithms was assessed using receiver-operating characteristic (ROC) area under the curve (AUC) analysis with data on presence-absence of I. scapularis obtained from recent field surveillance in the Prairie Provinces accumulated from a number of sources. The ROC AUC values for the risk algorithms were significantly different (P  0 °C, habitat as a simple dichotomous variable of presence or absence of forest, and normalized rainfall had the highest AUC of 0.74, representing "fair to good" performance of the risk algorithm. This algorithm had good (>80%) sensitivity in predicting positive I. scapularis surveillance sites, but low (50%) specificity as expected in this region where not all environmentally suitable habitats are expected to be occupied. Further prospective studies are needed to validate and perhaps improve the risk algorithm. © Crown copyright 2017.

  8. Adverse moisture events predict seasonal abundance of Lyme disease vector ticks (Ixodes scapularis)

    Science.gov (United States)

    Berger, Kathryn A.; Ginsberg, Howard S.; Dugas, Katherine D.; Hamel, Lutz H.; Mather, Thomas N.

    2014-01-01

    Background: Lyme borreliosis (LB) is the most commonly reported vector-borne disease in north temperate regions worldwide, affecting an estimated 300,000 people annually in the United States alone. The incidence of LB is correlated with human exposure to its vector, the blacklegged tick (Ixodes scapularis). To date, attempts to model tick encounter risk based on environmental parameters have been equivocal. Previous studies have not considered (1) the differences between relative humidity (RH) in leaf litter and at weather stations, (2) the RH threshold that affects nymphal blacklegged tick survival, and (3) the time required below the threshold to induce mortality. We clarify the association between environmental moisture and tick survival by presenting a significant relationship between the total number of tick adverse moisture events (TAMEs - calculated as microclimatic periods below a RH threshold) and tick abundance each year.Methods: We used a 14-year continuous statewide tick surveillance database and corresponding weather data from Rhode Island (RI), USA, to assess the effects of TAMEs on nymphal populations of I. scapularis. These TAMEs were defined as extended periods of time (>8 h below 82% RH in leaf litter). We fit a sigmoid curve comparing weather station data to those collected by loggers placed in tick habitats to estimate RH experienced by nymphal ticks, and compiled the number of historical TAMEs during the 14-year record.Results: The total number of TAMEs in June of each year was negatively related to total seasonal nymphal tick densities, suggesting that sub-threshold humidity episodes >8 h in duration naturally lowered nymphal blacklegged tick abundance. Furthermore, TAMEs were positively related to the ratio of tick abundance early in the season when compared to late season, suggesting that lower than average tick abundance for a given year resulted from tick mortality and not from other factors.Conclusions: Our results clarify the mechanism

  9. The Ixodes scapularis Salivary Protein, Salp15, Prevents the Association of HIV-1 gp120 and CD4

    OpenAIRE

    Juncadella, Ignacio J.; Garg, Renu; Bates, Tonya C.; Olivera, Elias R.; Anguita, Juan

    2007-01-01

    Ixodes scapularis salivary protein, Salp15, inhibits CD4+ T cell activation by binding to the most-extracellular domains of the CD4 molecule, potentially overlapping with the gp120-binding region. We now show that Salp15 inhibits the interaction of gp120 and CD4. Furthermore, Salp15 prevents syncytia formation between HL2/3 (a stable HeLa cell line expressing the envelope protein) and CD4-expressing cells. Salp15 prevented gp120-CD4 interaction at least partially through its direct interactio...

  10. Identification of Novel Viruses in Amblyomma americanum, Dermacentor variabilis, and Ixodes scapularis Ticks

    Science.gov (United States)

    Sameroff, Stephen; Tagliafierro, Teresa; Jain, Komal; Williams, Simon H.; Cucura, D. Moses; Rochlin, Ilia; Monzon, Javier; Carpi, Giovanna; Tufts, Danielle; Diuk-Wasser, Maria; Brinkerhoff, Jory; Lipkin, W. Ian

    2018-01-01

    ABSTRACT Ticks carry a wide range of known human and animal pathogens and are postulated to carry others with the potential to cause disease. Here we report a discovery effort wherein unbiased high-throughput sequencing was used to characterize the virome of 2,021 ticks, including Ixodes scapularis (n = 1,138), Amblyomma americanum (n = 720), and Dermacentor variabilis (n = 163), collected in New York, Connecticut, and Virginia in 2015 and 2016. We identified 33 viruses, including 24 putative novel viral species. The most frequently detected viruses were phylogenetically related to members of the Bunyaviridae and Rhabdoviridae families, as well as the recently proposed Chuviridae. Our work expands our understanding of tick viromes and underscores the high viral diversity that is present in ticks. IMPORTANCE The incidence of tick-borne disease is increasing, driven by rapid geographical expansion of ticks and the discovery of new tick-associated pathogens. The examination of the tick microbiome is essential in order to understand the relationship between microbes and their tick hosts and to facilitate the identification of new tick-borne pathogens. Genomic analyses using unbiased high-throughput sequencing platforms have proven valuable for investigations of tick bacterial diversity, but the examination of tick viromes has historically not been well explored. By performing a comprehensive virome analysis of the three primary tick species associated with human disease in the United States, we gained substantial insight into tick virome diversity and can begin to assess a potential role of these viruses in the tick life cycle. PMID:29564401

  11. Characterization of Ixophilin, a thrombin inhibitor from the gut of Ixodes scapularis.

    Directory of Open Access Journals (Sweden)

    Sukanya Narasimhan

    Full Text Available Ixodes scapularis, the black-legged tick, vectors several human pathogens including Borrelia burgdorferi, the agent of Lyme disease in North America. Pathogen transmission to the vertebrate host occurs when infected ticks feed on the mammalian host to obtain a blood meal. Efforts to understand how the tick confronts host hemostatic mechanisms and imbibes a fluid blood meal have largely focused on the anticoagulation strategies of tick saliva. The blood meal that enters the tick gut remains in a fluid state for several days during the process of feeding, and the role of the tick gut in maintaining the blood-meal fluid is not understood. We now demonstrate that the tick gut produces a potent inhibitor of thrombin, a key enzyme in the mammalian coagulation cascade. Chromatographic fractionation of engorged tick gut proteins identified one predominant thrombin inhibitory activity associated with an approximately 18 kDa protein, henceforth referred to as Ixophilin. The ixophilin gene was preferentially transcribed in the guts of feeding nymphs. Expression began after 24 hours of feeding, coincident with the flow of host blood into the tick gut. Immunity against Ixophilin delayed tick feeding, and decreased feeding efficiency significantly. Surprisingly, immunity against Ixophilin resulted in increased Borrelia burgdorferi transmission to the host, possibly due to delayed feeding and increased transmission opportunity. These observations illuminate the potential drawbacks of targeting individual tick proteins in a functional suite. They also underscore the need to identify the "anticoagulome" of the tick gut, and to prioritize a critical subset of anticoagulants that could be targeted to efficiently thwart tick feeding, and block pathogen transmission to the vertebrate host.

  12. Combining public participatory surveillance and occupancy modelling to predict the distributional response of Ixodes scapularis to climate change.

    Science.gov (United States)

    Lieske, David J; Lloyd, Vett K

    2018-03-01

    Ixodes scapularis, a known vector of Borrelia burgdorferi sensu stricto (Bbss), is undergoing range expansion in many parts of Canada. The province of New Brunswick, which borders jurisdictions with established populations of I. scapularis, constitutes a range expansion zone for this species. To better understand the current and potential future distribution of this tick under climate change projections, this study applied occupancy modelling to distributional records of adult ticks that successfully overwintered, obtained through passive surveillance. This study indicates that I. scapularis occurs throughout the southern-most portion of the province, in close proximity to coastlines and major waterways. Milder winter conditions, as indicated by the number of degree days model with a predictive accuracy of 0.845 (range: 0.828-0.893). Both RCP 4.5 and RCP 8.5 climate projections predict that a significant proportion of the province (roughly a quarter to a third) will be highly suitable for I. scapularis by the 2080s. Comparison with cases of canine infection show good spatial agreement with baseline model predictions, but the presence of canine Borrelia infections beyond the climate envelope, defined by the highest probabilities of tick occurrence, suggest the presence of Bbss-carrying ticks distributed by long-range dispersal events. This research demonstrates that predictive statistical modelling of multi-year surveillance information is an efficient way to identify areas where I. scapularis is most likely to occur, and can be used to guide subsequent active sampling efforts in order to better understand fine scale species distributional patterns. Copyright © 2018 The Authors. Published by Elsevier GmbH.. All rights reserved.

  13. Field and laboratory responses of adult Ixodes scapularis (Acari: Ixodidae) to kairomones produced by white-tailed deer.

    Science.gov (United States)

    Carroll, J F; Mills, G D; Schmidtmann, E T

    1996-07-01

    In a field test, adult blacklegged ticks, Ixodes scapularis Say, of both sexes exhibited an arrestant response to substances associated with external glands on the legs of white-tailed deer, Odocoileus virginianus (Zimmermann), their principal host. Substances rubbed from the pelage covering tarsal and interdigital glands were applied to artificial vantage points simulating vegetation on which I. scapularis adults wait for host contact. A combination of tarsal substances (applied to the apex of the simulated vantage point) and interdigital gland substances (applied to the horizontal base) elicited a greater response than either treatment alone. A minimal response was observed on untreated vantage points. In laboratory bioassays using glass tubing as vantage points, substances associated with preorbital glands of deer elicited a strong arrestant response among I. scapularis females, whereas samples rubbed from the forehead, back, and a nonglandular area on deer tarsi evoked weak arrestant responses. These results support the hypothesis that the kairomonal properties of host-generated residues, either in conjunction with or in lieu of the effects of carbon dioxide, help account for the prevalence of host-seeking ticks along animal trails.

  14. Efficacy and environmental persistence of nootkatone for the control of the blacklegged tick, Ixodes scapularis (Acari: Ixodidae) in the residential landscape

    Science.gov (United States)

    We evaluated the ability of the plant-derived compound nootkatone to control nymphs of the blacklegged tick, Ixodes scapularis Say, applied to the perimeter of lawns around homes in Lyme disease endemic areas of Connecticut. Three formulations of nootkatone ranging from 0.05 to 0.84% (0.06 to 1.03 g...

  15. Preliminary survey for entomopathogenic fungi associated with Ixodes scapularis>/i> (Acari: Ixodidae) in southern New York and New England, USA

    Science.gov (United States)

    Zhioua, Elyes; Ginsberg, Howard S.; Humber, Richard A.; LeBrun, Roger A.

    1999-01-01

    Free-living larval, nymphal, and adult Ixodes scapularis Say were collected from scattered locales in southern New England and New York to determine infection rates with entomopathogenic fungi. Infection rates of larvae, nymphs, males, and females were 0% (571), 0% (272), 0% (57), and 4.3% (47), respectively. Two entomopathogenic fungi were isolated from field-collected I. scapularis females from Fire Island, NY. Isolates were identified as Verticillium lecanii (Zimmermann) Viegas and Verticillium sp. (a member of the Verticillium lecanii species complex).Ixodes scapularis Say is the principal vector of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner (Burgdorfer et al. 1982, Johnson et al. 1984), the etiologic agent of Lyme disease in the northeastern and upper-midwestern United States. Control of I. scapularis is based on chemical treatment (Mather et al. 1987b; Schulze et al. 1987, 1991), environmental management (Wilson et al. 1988, Schulze et al. 1995), and habitat modification (Wilson 1986). These methods have shown variable success, and some potentially have negative environmental effects (Wilson and Deblinger 1993, Ginsberg 1994).Studies concerning natural predators, parasitoids, and pathogens of I. scapularis are rare. The use of ground-dwelling birds as tick predators has had only limited success (Duffy et al. 1992). Nymphal I. scapularis are often infected with the parasitic wasp Ixodiphagus hookeri (Howard) (Mather et al. 1987a, Hu et al. 1993, Stafford et al. 1996, Hu and Hyland 1997), but this wasp does not effectively control I. scapularis populations (Stafford et al. 1996). The entomopathogenic nematodes Steinernema carpocapsae (Weiser) and S. glaseri (Steiner) are pathogenic only to engorged female I. scapularis, and thus have limited applicability (Zhioua et al. 1995). In contrast, the entomogenous fungus Metarhizium anisopliae (Metschnikoff) Sorokin is highly pathogenic to all stages of I. scapularis, unfed as well as engorged

  16. Ability of two natural products, nootkatone and carvacrol, to suppress Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey.

    Science.gov (United States)

    Dolan, Marc C; Jordan, Robert A; Schulze, Terry L; Schulze, Christopher J; Manning, Mark Cornell; Ruffolo, Daniel; Schmidt, Jason P; Piesman, Joseph; Karchesy, Joseph J

    2009-12-01

    We evaluated the ability of the natural, plant-derived acaricides nootkatone and carvacrol to suppress Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae). Aqueous formulations of 1 and 5% nootkatone applied by backpack sprayer to the forest litter layer completely suppressed I. scapularis nymphs through 2 d. Thereafter, the level of reduction gradually declined to nootkatone was less effective, but at a 5% concentration, the level of control was similar or greater to that observed with I. scapularis through 21 d postapplication. Initial applications of 0.05% carvacrol were ineffective, but a 5% carvacrol formulation completely suppressed nymphs of both species through 2 d and resulted in significant reduction in I. scapularis and A. americanum nymphs through 28 and 14 d postapplication, respectively. Backpack sprayer applications of 5% nootkatone to the shrub and litter layers resulted in 100% control of I. scapularis adults through 6 d, but the level of reduction declined to 71.5% at 28 d postapplication. By contrast, high-pressure applications of 2% nootkatone to the litter layer resulted in 96.2-100% suppression of both I. scapularis and A. americanum nymphs through 42 d, whereas much lower control was obtained from the same formulation applied by backpack sprayer. Backpack sprayer application of a 3.1% nootkatone nanoemulsion resulted in 97.5-98.9 and 99.3-100% reduction in I. scapularis and A. americanum nymphs, respectively, at 1 d postapplication. Between 7 d and 35 d postapplication, the level of control varied between 57.1% and 92.5% for I. scapularis and between 78.5 and 97.1% for A. americanum nymphs. The ability of natural products to quickly suppress and maintain significant control of populations of these medically important ticks at relatively low concentrations may represent a future alternative to the use of conventional synthetic acaricides.

  17. Potential of Tenebrio molitor (Coleoptera: Tenebrionidae) as a bioassay probe for Metarhizium brunneum (Hypocreales: Clavicipitaceae) activity against Ixodes scapularis (Acari: Ixodidae).

    Science.gov (United States)

    Bharadwaj, Anuja; Stafford, Kirby C

    2011-12-01

    The yellow mealworm, Tenebrio molitor L., has been used to indicate qualitatively the presence of entomopathogenic fungi in the soil or as a model for evaluating stress and other factors on fungal activity. Although this beetle appears highly susceptible to many of these fungi, little quantitative information is available on the sensitivity of T. molitor to a specific fungus and, therefore, fungal presence or as an indicator for pathogenicity to other species. The purpose of this study was to establish the suitability of T. molitor larvae as a bioassay probe for Metarhizium brunneum for comparison against the blacklegged tick, Ixodes scapularis. Nine concentrations of M. brunneum strain F52 ranging from 1.0 x 10(1) to 8.4 x 10(8) conidial/ml were simultaneously tested against T. molitor larvae and I. scapularis adults. Larvae of yellow mealworm were less sensitive to M. brunneum than I. scapularis adults (LC50's 4.4 x 10(7) and 1.7 x 10(5) conidia/ml, respectively, 4-wk post-treatment). The greater sensitivity of I. scapularis to the fungus suggests that the detection of fungal mycosis in mealworms would indicate sufficient inoculum to be pathogenic to I. scapularis and make this insect a suitable probe for evaluation of the presence and activity of M. brunneum against the blacklegged tick in field applications.

  18. No Observed Effect of Landscape Fragmentation on Pathogen Infection Prevalence in Blacklegged Ticks (Ixodes scapularis in the Northeastern United States.

    Directory of Open Access Journals (Sweden)

    Christine P Zolnik

    Full Text Available Pathogen prevalence within blacklegged ticks (Ixodes scapularis Say, 1821 tends to vary across sites and geographic regions, but the underlying causes of this variation are not well understood. Efforts to understand the ecology of Lyme disease have led to the proposition that sites with higher host diversity will result in lower disease risk due to an increase in the abundance of inefficient reservoir species relative to the abundance of species that are highly competent reservoirs. Although the Lyme disease transmission cycle is often cited as a model for this "dilution effect hypothesis", little empirical evidence exists to support that claim. Here we tested the dilution effect hypothesis for two pathogens transmitted by the blacklegged tick along an urban-to-rural gradient in the northeastern United States using landscape fragmentation as a proxy for host biodiversity. Percent impervious surface and habitat fragment size around each site were determined to assess the effect of landscape fragmentation on nymphal blacklegged tick infection with Borrelia burgdorferi and Anaplasma phagocytophilum. Our results do not support the dilution effect hypothesis for either pathogen and are in agreement with the few studies to date that have tested this idea using either a landscape proxy or direct measures of host biodiversity.

  19. Tick histamine release factor is critical for Ixodes scapularis engorgement and transmission of the lyme disease agent.

    Directory of Open Access Journals (Sweden)

    Jianfeng Dai

    2010-11-01

    Full Text Available Ticks are distributed worldwide and affect human and animal health by transmitting diverse infectious agents. Effective vaccines against most tick-borne pathogens are not currently available. In this study, we characterized a tick histamine release factor (tHRF from Ixodes scapularis and addressed the vaccine potential of this antigen in the context of tick engorgement and B. burgdorferi transmission. Results from western blotting and quantitative Reverse Transcription-PCR showed that tHRF is secreted in tick saliva, and upregulated in Borrelia burgdorferi-infected ticks. Further, the expression of tHRF was coincident with the rapid feeding phase of the tick, suggesting a role for tHRF in tick engorgement and concomitantly, for efficient B. burgdorferi transmission. Silencing tHRF by RNA interference (RNAi significantly impaired tick feeding and decreased B. burgdorferi burden in mice. Interfering with tHRF by actively immunizing mice with recombinant tHRF, or passively transferring tHRF antiserum, also markedly reduced the efficiency of tick feeding and B. burgdorferi burden in mice. Recombinant tHRF was able to bind to host basophils and stimulate histamine release. Therefore, we speculate that tHRF might function in vivo to modulate vascular permeability and increase blood flow to the tick bite-site, facilitating tick engorgement. These findings suggest that blocking tHRF might offer a viable strategy to complement ongoing efforts to develop vaccines to block tick feeding and transmission of tick-borne pathogens.

  20. To beat or not to beat a tick: comparison of DNA extraction methods for ticks (Ixodes scapularis

    Directory of Open Access Journals (Sweden)

    Alyssa D. Ammazzalorso

    2015-08-01

    Full Text Available Background. Blacklegged ticks (Ixodes scapularis are important disease vectors in the United States, known to transmit a variety of pathogens to humans, including bacteria, protozoa, and viruses. Their importance as a disease vector necessitates reliable and comparable methods for extracting microbial DNA from ticks. Furthermore, to explore the population genetics or genomics of this tick, appropriate DNA extraction techniques are needed for both the vector and its microbes. Although a few studies have investigated different methods of DNA isolation from ticks, they are limited in the number and types of DNA extraction and lack species-specific quantification of DNA yield.Methods. Here we determined the most efficient and consistent method of DNA extraction from two different developmental stages of I. scapularis—nymph and adult—that are the most important for disease transmission. We used various methods of physical disruption of the hard, chitinous exoskeleton, as well as commercial and non-commercial DNA isolation kits. To gauge the effectiveness of these methods, we quantified the DNA yield and confirmed the DNA quality via PCR of both tick and microbial genetic material.Results. DNA extraction using the Thermo GeneJET Genomic DNA Purification Kit resulted in the highest DNA yields and the most consistent PCR amplification when combined with either cutting or bead beating with select matrices across life stages. DNA isolation methods using ammonium hydroxide as well as the MoBio PowerSoil kit also produced strong and successful PCR amplification, but only for females.Discussion. We contrasted a variety of readily available methods of DNA extraction from single individual blacklegged ticks and presented the results through a quantitative and qualitative assessment.

  1. Effects of Japanese barberry (Ranunculales: Berberidaceae) removal and resulting microclimatic changes on Ixodes scapularis (Acari: Ixodidae) abundances in Connecticut, USA.

    Science.gov (United States)

    Williams, Scott C; Ward, Jeffrey S

    2010-12-01

    Japanese barberry (Berberis thunbergii de Candolle) is a thorny, perennial, exotic, invasive shrub that is well established throughout much of the eastern United States. It can form dense thickets that limit native herbaceous and woody regeneration, alter soil structure and function, and harbor increased blacklegged tick (Ixodes scapularis Say) populations. This study examined a potential causal mechanism for the link between Japanese barberry and blacklegged ticks to determine if eliminating Japanese barberry could reduce tick abundance and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner). Japanese barberry was controlled at five study areas throughout Connecticut; adult ticks were sampled over three years. Each area had three habitat plots: areas where barberry was controlled, areas where barberry remained intact, and areas where barberry was minimal or absent. Sampled ticks were retained and tested for B. burgdorferi presence. At two study areas, temperature and relative humidity data loggers were deployed in each of the three habitat plots over two growing seasons. Intact barberry stands had 280 ± 51 B. burgdorferi-infected adult ticks/ha, which was significantly higher than for controlled (121 ± 17/ha) and no barberry (30 ± 10/ha) areas. Microclimatic conditions where Japanese barberry was controlled were similar to areas without barberry. Japanese barberry infestations are favorable habitat for ticks, as they provide a buffered microclimate that limits desiccation-induced tick mortality. Control of Japanese barberry reduced the number of ticks infected with B. burgdorferi by nearly 60% by reverting microclimatic conditions to those more typical of native northeastern forests. © 2010 Entomological Society of America

  2. Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA.

    Science.gov (United States)

    Williams, Scott C; Linske, Megan A; Ward, Jeffrey S

    2017-12-08

    Japanese barberry (Berberis thunbergii de Candolle; Ranunculales: Berberidaceae) is an exotic invasive shrub that escaped cultivation in the United States and is now permanently established in many eastern and midwestern states. This study examined the long-term impacts of Japanese barberry management on blacklegged tick (Ixodes scapularis Say; Acari: Ixodidae) abundances and associated prevalence of Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner; Spirochaetales: Spirochaetaceae), the etiologic agent of Lyme disease. At six locations across Connecticut, adult I. scapularis were sampled for up to 10 yr. At each location, we sampled an area where barberry infestations were unmanipulated, adjacent areas where barberry was virtually nonexistent, and areas where barberry was managed utilizing a variety of techniques. Barberry management reduced B. burgdorferi-infected adult I. scapularis (BBIAIS) abundances (191/ha ± 64 SE) over 6 yr to statistically indifferent from that of no barberry areas (140/ha ± 47 SE; P = 0.080) and significantly less than intact barberry stands (458/ha ± 80 SE; P = 0.026). Over 9 yr, BBIAIS abundances in managed barberry remained lower than intact barberry stands (P = 0.037), but increased to be significantly greater than no barberry areas (P = 0.007) as cover increased over time. Longer-term data further document that Japanese barberry infestations are favorable habitat for I. scapularis. Control of Japanese barberry and other invasives should be at least on a 5-yr rotation to maintain low levels of invasive cover and eliminate humidity refugia to expose juvenile I. scapularis to more hostile environmental conditions in the interest of public health. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Efficacy of sarolaner in the prevention of Borrelia burgdorferi and Anaplasma phagocytophilum transmission from infected Ixodes scapularis to dogs.

    Science.gov (United States)

    Honsberger, Nicole A; Six, Robert H; Heinz, Thomas J; Weber, Angela; Mahabir, Sean P; Berg, Thomas C

    2016-05-30

    The efficacy of sarolaner (Simparica™, Zoetis) to prevent transmission primarily of Borrelia burgdorferi and secondarily of Anaplasma phagocytophilum from infected wild-caught Ixodes scapularis to dogs was evaluated in a placebo-controlled laboratory study. Twenty-four purpose-bred laboratory Beagles seronegative for B. burgdorferi and A. phagocytophilum antibodies were allocated randomly to one of three treatment groups: placebo administered orally on Days 0 and 7, or sarolaner at 2mg/kg administered orally on Day 0 (28 days prior to tick infestation) or on Day 7 (21 days prior to tick infestation). On Day 28, each dog was infested with approximately 25 female and 25 male wild caught adult I. scapularis that were determined to have prevalence of 57% for B. burgdorferi and 6.7% for A. phagocytophilum by PCR. In situ tick counts were conducted on Days 29 and 30. On Day 33, all ticks were counted and removed. Acaricidal efficacy was calculated based on the reduction of geometric mean live tick counts in the sarolaner-treated groups compared to the placebo-treated group for each tick count. Blood samples collected from each dog on Days 27, 49, 63, 77, 91 and 104 were tested for the presence of B. burgdorferi and A. phagocytophilum antibodies using the SNAP(®) 4Dx(®) Plus Test, and quantitatively assayed for B. burgdorferi antibodies using an ELISA test. Skin biopsies collected on Day 104 were tested for the presence of B. burgdorferi by bacterial culture and PCR. Geometric mean live tick counts for placebo-treated dogs were 14.8, 12.8, and 19.1 on Days 29, 30, and 33, respectively. The percent reductions in mean live tick counts at 1, 2, and 5 days after infestation were 86.3%, 100%, and 100% for the group treated with sarolaner 21 days prior to infestation, and 90.9%, 97.1%, and 100% for the group treated with sarolaner 28 days prior to infestation. Geometric mean live tick counts for both sarolaner-treated groups were significantly lower than those for the

  4. Suppression of host-seeking Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) nymphs after dual applications of plant-derived acaricides in New Jersey.

    Science.gov (United States)

    Jordan, Robert A; Dolan, Marc C; Piesman, Joseph; Schulze, Terry L

    2011-04-01

    We evaluated the ability of dual applications of natural, plant-derived acaricides to suppress nymphal Ixodes scapularis Say and Amblyomma americanum (L.) (Acari: Ixodidae) in a Lyme disease endemic area of New Jersey. An aqueous formulation of 2% nootkatone provided >90% control of I. scapularis through 7 d. Control declined to 80.9% at 14 d, and a second application was made that provided >95% control through the remaining 4 wk of the nymphal season. Nootkatone provided >90% control of A. americanum through 35 d postapplication. Applications of 2% carvacrol and EcoTrol T&O resulted in rapid knockdown of both tick species, but control declined significantly to 76.7 and 73.7%, respectively, after 14 d when a second application was made that extended control of both tick species to between 86.2 and 94.8% at 21 d. Subsequently, control declined steadily in all plots by 42 d postapplication except for I. scapularis in carvacrol-treated plots, where levels of control >90% were observed through 35 d. Of the three compounds tested, 2% nootkatone provided the most consistent results, with 96.5 and 91.9% control of I. scapularis and A. americanum through 42 and 35 d, respectively. The ability of plant-derived natural products to quickly suppress and maintain significant control of populations of these medically important ticks may represent a future alternative to the use of conventional synthetic acaricides. In addition, the demonstrated efficacy of properly-timed backpack sprayer application may enable homeowner access to these minimal-risk acaricides.

  5. Identification and Characterization of Ixodes scapularis Antigens That Elicit Tick Immunity Using Yeast Surface Display

    NARCIS (Netherlands)

    Schuijt, T.J.; Narasimhan, S.; Daffre, S.; Deponte, K.; Hovius, J.W.R.; van 't Veer, C.; van der Poll, T.; Bakhtiari, K.; Meijers, J.C.M.; Boder, E.T.; van Dam, A.P.; Fikrig, E.

    2011-01-01

    Repeated exposure of rabbits and other animals to ticks results in acquired resistance or immunity to subsequent tick bites and is partially elicited by antibodies directed against tick antigens. In this study we demonstrate the utility of a yeast surface display approach to identify tick salivary

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

    Directory of Open Access Journals (Sweden)

    Lucas Tirloni

    2017-12-01

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

  7. Susceptibility of four tick species, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus (Acari: Ixodidae), to nootkatone from essential oil of grapefruit.

    Science.gov (United States)

    Flor-Weiler, Lina B; Behle, Robert W; Stafford, Kirby C

    2011-03-01

    Toxicity of nootkatone was determined in laboratory assays against unfed nymphs of Amblyomma americanum L., Dermacentor variabilis (Say), Ixodes scapularis Say, and Rhipicephalus sanguineus Latreille. We determined the 50% lethal concentration (LC50) and 90% lethal concentration (LC90) of nootkatone by recording tick mortality 24 h after exposure in treated glass vials. Nymphs were susceptible to nootkatone with LC50 values of 0.352, 0.233, 0.169, and 0.197 microg/cm2, and LC90 values of 1.001, 0.644, 0.549, and 0.485 microg/cm2 for A. americanum, D. variabilis, I. scapularis, and R. sanguineus, respectively. The LC50 value for R. sanquineus was not significantly different from D. variabilis or I. scapularis. Other LC50 comparisons were significantly different. The LC90 for A. americanum was higher when compared with the three other tick species, which were not significantly different. Because nootkatone is volatile, we measured the amount of nootkatone recovered from duplicate-treated vials before tick exposure and from vials after tick exposure. Nootkatone recovered from vials before exposure ranged from 82 to 112% of the expected amounts. The nootkatone recovered after the 24-h exposure period ranged from 89% from vials coated with higher concentrations of nootkatone, down to 29% from vials coated with low nootkatone concentrations. Determination of the nootkatone residue after vial coating demonstrated loss of the active compound while verifying the levels of tick exposure. Toxicity of low concentrations of nootkatone to the active questing stage of ticks reported in this study provides a reference point for future formulation research to exploit nootkatone as a safe and environment-friendly tick control.

  8. Ixodes scapularis and Ixodes ricinus tick cell lines respond to infection with tick-borne encephalitis virus: transcriptomic and proteomic analysis

    Czech Academy of Sciences Publication Activity Database

    Weisheit, S.; Villar, M.; Tykalová, Hana; Popara, M.; Loecherbach, J.; Watson, M.; Růžek, Daniel; Grubhoffer, Libor; de la Fuente, J.; Fazakerley, J.K.; Bell-Sakyi, L.

    2015-01-01

    Roč. 8, NOV 18 2015 (2015), s. 599 ISSN 1756-3305 R&D Projects: GA ČR GA15-03044S; GA ČR GAP502/11/2116 EU Projects: European Commission(XE) 238511 Institutional support: RVO:60077344 Keywords : tisk * Ixodes * flavivirus * tick-borne encephalitis virus * tick cell line * innate immunity * antiviral response Subject RIV: EE - Microbiology, Virology Impact factor: 3.234, year: 2015

  9. Experimental use of two standard tick collection methods to evaluate the relative effectiveness of several plant-derived and synthetic repellents against Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

    Science.gov (United States)

    Schulze, Terry L; Jordan, Robert A; Dolan, Marc C

    2011-12-01

    We used two standard tick collection methods to test the relative effectiveness of two natural product compounds (nootkatone and carvacrol, classified as an eremophilene sesquiterpene and a monoterpene, respectively, that are derived from botanical sources) with commercially-available plant-derived (EcoSMART Organic Insect Repellent, comprised of plant essential oils) and permethrin-based (Repel Permanone) repellents against Ixodes scapularis Say and Amblyomma americanum (L.). Cloth drags were equally effective in sampling both species of host-seeking nymphs, whereas CO, traps attracted primarily A. americanum. All four repellents performed well on drags, with nootkatone and Permanone Repel (100% repelled through 14 d) slightly more effective than carvacrol and EcoSMART (90.7% and 97.7% repelled at 14 d, respectively) at repelling I. scapularis nymphs. Although the same trend in percent repellency was noted in the CO2 trap trial against both A. americanum nymphs and adults, EcoSMART outperformed Permanone in repelling A. Americanum nymphs after 14 d in the drag trial. Generally, the effectiveness of all repellents tested declined over time. The use of tick drags and CO2 traps was rapid, inexpensive, and easy to use in determining the relative effectiveness of repellents in the field.

  10. The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

    Energy Technology Data Exchange (ETDEWEB)

    Kotsyfakis, Michalis; Horka, Helena; Salat, Jiri; Andersen, John F. (South Bohemia); (ASCR-ICP); (NIAID)

    2010-11-17

    We have previously demonstrated that two salivary cysteine protease inhibitors from the Borrelia burgdorferi (Lyme disease) vector Ixodes scapularis - namely sialostatins L and L2 - play an important role in tick biology, as demonstrated by the fact that silencing of both sialostatins in tandem results in severe feeding defects. Here we show that sialostatin L2 - but not sialostatin L - facilitates the growth of B. burgdorferi in murine skin. To examine the structural basis underlying these differential effects of the two sialostatins, we have determined the crystal structures of both sialostatin L and L2. This is the first structural analysis of cystatins from an invertebrate source. Sialostatin L2 crystallizes as a monomer with an 'unusual' conformation of the N-terminus, while sialostatin L crystallizes as a domain-swapped dimer with an N-terminal conformation similar to other cystatins. Deletion of the 'unusual' N-terminal five residues of sialostatin L2 results in marked changes in its selectivity, suggesting that this region is a particularly important determinant of the biochemical activity of sialostatin L2. Collectively, our results reveal the structure of two tick salivary components that facilitate vector blood feeding and that one of them also supports pathogen transmission to the vertebrate host.

  11. Effects of tick control by acaricide self-treatment of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens.

    Science.gov (United States)

    Hoen, Anne Gatewood; Rollend, Lindsay G; Papero, Michele A; Carroll, John F; Daniels, Thomas J; Mather, Thomas N; Schulze, Terry L; Stafford, Kirby C; Fish, Durland

    2009-08-01

    We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three Ixodes scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the "4-Poster" device and from control areas over a 6-year period in five geographically diverse study locations in the Northeastern United States and tested for infection with two known agents of human disease, Borrelia burgdorferi and Anaplasma phagocytophilum, and for a novel relapsing fever-group spirochete related to Borrelia miyamotoi. Overall, 38.2% of adults and 12.5% of nymphs were infected with B. burgdorferi; 8.5% of adults and 4.2% of nymphs were infected with A. phagocytophilum; and 1.9% of adults and 0.8% of nymphs were infected with B. miyamotoi. In most cases, treatment with the 4-Poster device was not associated with changes in the prevalence of infection with any of these three microorganisms among nymphal or adult ticks. However, the density of nymphs infected with B. burgdorferi, and consequently the entomologic risk for Lyme disease, was reduced overall by 68% in treated areas compared to control areas among the five study sites at the end of the study. The frequency of bacterial coinfections in ticks was generally equal to the product of the proportion of ticks infected with a single bacterium, indicating that enzootic maintenance of these pathogens is independent. We conclude that controlling ticks on deer by self-application of acaricide results in an overall decrease in the human risk for exposure to these three bacterial agents, which is due solely to a reduction in tick density.

  12. Identification of Salp15 homologues in Ixodes ricinus ticks

    NARCIS (Netherlands)

    Hovius, J. W. R.; Ramamoorthi, N.; van't Veer, C.; de Groot, K. A.; Nijhof, A. M.; Jongejan, F.; van Dam, A. P.; Fikrig, E.

    2007-01-01

    The 15-kDa Ixodes scapularis salivary gland protein Salp15 protects Borrelia burgdorferi sensu stricto from antibody-mediated killing and facilitates infection of the mammalian host. In addition, Salp 15 has been shown to inhibit T-cell activation. We determined whether Ixodes ricinus, the major

  13. Effects of tick control by acaricide self-treatement of white-tailed deer on host-seeking tick infection prevalence and entomologic risk for Ixodes scapularis-borne pathogens

    Science.gov (United States)

    We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three I. scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the ‘4-Poster’ device and from control a...

  14. Preferential protection of Borrelia burgdorferi sensu stricto by a Salp15 homologue in Ixodes ricinus saliva

    NARCIS (Netherlands)

    Hovius, J. W.; Schuijt, T. J.; de Groot, K. A.; Roelofs, J. J. T. H.; Oei, G. A.; Marquart, J. A.; de Beer, R.; van 't Veer, C.; van der Poll, T.; Ramamoorthi, N.; Fikrig, E.; van Dam, A. P.

    2008-01-01

    BACKGROUND: Ixodes ticks are the main vectors for Borrelia burgdorferi sensu lato. In the United States, B. burgdorferi is the sole causative agent of Lyme borreliosis and is transmitted by Ixodes scapularis. In Europe, 3 Borrelia species-B. burgdorferi, B. garinii, and B. afzelii-are prevalent,

  15. Molecular Detection and Identification of Rickettsia Species in Ixodes pacificus in California

    Science.gov (United States)

    Phan, Jimmy Ninh; Lu, Casey Roy; Bender, William Garrett; Smoak, Robert Marion

    2011-01-01

    Abstract We amplified 16S rRNA, gltA, and ompA genes from Ixodes pacificus by polymerase chain reaction. Sequencing, BLAST analysis, and phylogenetic constructions indicated that two Rickettsia phylotypes are present in I. pacificus. While phylotype G021 has high homology to Ixodes scapularis endosymbiotic Rickettsia, phylotype G022 is a deeply branched novel spotted fever group Rickettsia. PMID:21413886

  16. An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement

    NARCIS (Netherlands)

    Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J.; Oei, Anneke; Nijhof, Ard M.; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D.; Hovius, Joppe W. R.

    2016-01-01

    We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement

  17. Ixodes ticks belonging to the Ixodes ricinus complex encode a family of anticomplement proteins.

    Science.gov (United States)

    Daix, V; Schroeder, H; Praet, N; Georgin, J-P; Chiappino, I; Gillet, L; de Fays, K; Decrem, Y; Leboulle, G; Godfroid, E; Bollen, A; Pastoret, P-P; Gern, L; Sharp, P M; Vanderplasschen, A

    2007-04-01

    The alternative pathway of complement is an important innate defence against pathogens including ticks. This component of the immune system has selected for pathogens that have evolved countermeasures. Recently, a salivary protein able to inhibit the alternative pathway was cloned from the American tick Ixodes scapularis (Valenzuela et al., 2000; J. Biol. Chem. 275, 18717-18723). Here, we isolated two different sequences, similar to Isac, from the transcriptome of I. ricinus salivary glands. Expression of these sequences revealed that they both encode secreted proteins able to inhibit the complement alternative pathway. These proteins, called I. ricinus anticomplement (IRAC) protein I and II, are coexpressed constitutively in I. ricinus salivary glands and are upregulated during blood feeding. Also, we demonstrated that they are the products of different genes and not of alleles of the same locus. Finally, phylogenetic analyses demonstrate that ticks belonging to the Ixodes ricinus complex encode a family of relatively small anticomplement molecules undergoing diversification by positive Darwinian selection.

  18. Homogeneity of Powassan virus populations in naturally infected Ixodes scapularis

    International Nuclear Information System (INIS)

    Brackney, Doug E.; Brown, Ivy K.; Nofchissey, Robert A.; Fitzpatrick, Kelly A.; Ebel, Gregory D.

    2010-01-01

    Powassan virus (POWV, Flaviviridae: Flavivirus) is the sole North American member of the tick-borne encephalitis complex and consists of two distinct lineages that are maintained in ecologically discrete enzootic transmission cycles. The underlying genetic mechanisms that lead to niche partitioning in arboviruses are poorly understood. Therefore, intra- and interhost genetic diversity was analyzed to determine if POWV exists as a quasispecies in nature and quantify selective pressures within and between hosts. In contrast to previous reports for West Nile virus (WNV), significant intrahost genetic diversity was not observed. However, pN (0.238) and d N /d S ratios (0.092) for interhost diversity were similar to those of WNV. Combined, these data suggest that purifying selection and/or population bottlenecks constrain quasispecies diversity within ticks. These same selective and stochastic mechanisms appear to drive minor sequence changes between ticks. Moreover, Powassan virus populations seem not to be structured as quasispecies in naturally infected adult deer ticks.

  19. Identification and characterization of histidine-rich peptides from hard ticks Ixodes ricinus and Ixodes scapularis.

    OpenAIRE

    DORŇÁKOVÁ, Veronika

    2011-01-01

    Antimicrobial (cationic) proteins play an important role in innate imunity. Such proteins can possess antibacterial, antiendotoxic or fungicidal abilities. The rising resistence of microbes to common antibiotics evokes acute need of studying more endogenous proteins to reveal new potential antibiotics. Ticks, the blood-feeding ectoparasites with effectual defense system, present an endless source of newly described and unknown antimicrobial peptides/proteins with significant theurapeutic pote...

  20. Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex

    Science.gov (United States)

    Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R. Jory; Gonzalez, Antonio; Parobek, Christian M.; Juliano, Jonathan J.; Andreadis, Theodore G.; Falco, Richard C.; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A.; Roe, R. Michael; Apperson, Charles S.; Knight, Rob

    2015-01-01

    Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. PMID:26150449

  1. Variation in the Microbiota of Ixodes Ticks with Regard to Geography, Species, and Sex.

    Science.gov (United States)

    Van Treuren, Will; Ponnusamy, Loganathan; Brinkerhoff, R Jory; Gonzalez, Antonio; Parobek, Christian M; Juliano, Jonathan J; Andreadis, Theodore G; Falco, Richard C; Ziegler, Lorenza Beati; Hathaway, Nicholas; Keeler, Corinna; Emch, Michael; Bailey, Jeffrey A; Roe, R Michael; Apperson, Charles S; Knight, Rob; Meshnick, Steven R

    2015-09-01

    Ixodes scapularis is the principal vector of Lyme disease on the East Coast and in the upper Midwest regions of the United States, yet the tick is also present in the Southeast, where Lyme disease is absent or rare. A closely related species, I. affinis, also carries the pathogen in the South but does not seem to transmit it to humans. In order to better understand the geographic diversity of the tick, we analyzed the microbiota of 104 adult I. scapularis and 13 adult I. affinis ticks captured in 19 locations in South Carolina, North Carolina, Virginia, Connecticut, and New York. Initially, ticks from 4 sites were analyzed by 454 pyrosequencing. Subsequently, ticks from these sites plus 15 others were analyzed by sequencing with an Illumina MiSeq machine. By both analyses, the microbiomes of female ticks were significantly less diverse than those of male ticks. The dissimilarity between tick microbiomes increased with distance between sites, and the state in which a tick was collected could be inferred from its microbiota. The genus Rickettsia was prominent in all locations. Borrelia was also present in most locations and was present at especially high levels in one site in western Virginia. In contrast, members of the family Enterobacteriaceae were very common in North Carolina I. scapularis ticks but uncommon in I. scapularis ticks from other sites and in North Carolina I. affinis ticks. These data suggest substantial variations in the Ixodes microbiota in association with geography, species, and sex. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. An Ixodes ricinus Tick Salivary Lectin Pathway Inhibitor Protects Borrelia burgdorferi sensu lato from Human Complement.

    Science.gov (United States)

    Wagemakers, Alex; Coumou, Jeroen; Schuijt, Tim J; Oei, Anneke; Nijhof, Ard M; van 't Veer, Cornelis; van der Poll, Tom; Bins, Adriaan D; Hovius, Joppe W R

    2016-04-01

    We previously identified tick salivary lectin pathway inhibitor (TSLPI) in Ixodes scapularis, a vector for Borrelia burgdorferi sensu stricto (s.s.) in North America. TSLPI is a salivary protein facilitating B. burgdorferi s.s. transmission and acquisition by inhibiting the host lectin complement pathway through interference with mannose binding lectin (MBL) activity. Since Ixodes ricinus is the predominant vector for Lyme borreliosis in Europe and transmits several complement sensitive B. burgdorferi sensu lato (s.l.) strains, we aimed to identify, describe, and characterize the I. ricinus ortholog of TSLPI. We performed (q)PCRs on I. ricinus salivary gland cDNA to identify a TSLPI ortholog. Next, we generated recombinant (r)TSLPI in a Drosophila expression system and examined inhibition of the MBL complement pathway and complement-mediated killing of B. burgdorferi s.l. in vitro. We identified a TSLPI ortholog in I. ricinus salivary glands with 93% homology at the RNA and 89% at the protein level compared to I. scapularis TSLPI, which was upregulated during tick feeding. In silico analysis revealed that TSLPI appears to be part of a larger family of Ixodes salivary proteins among which I. persulcatus basic tail salivary proteins and I. scapularis TSLPI and Salp14. I. ricinus rTSLPI inhibited the MBL complement pathway and protected B. burgdorferi s.s. and Borrelia garinii from complement-mediated killing. We have identified a TSLPI ortholog, which protects B. burgdorferi s.l. from complement-mediated killing in I. ricinus, the major vector for tick-borne diseases in Europe.

  3. [Changes in the expression of salivary gland genes in Ixodes persulcatus (Ixodidae) depending on the stage of tick feeding].

    Science.gov (United States)

    Shtannikov, A V; Perovskaia, O N; Reshetniak, T V; Repolovskaia, T V; Panfertsev, E A; Sergeeva, E E; Gutova, V P; Vasil'eva, I S; Ershova, A S; Prilipov, A G; Biketov, S F; Zeidner, N

    2009-01-01

    By using the guanidine-isothiocyanate test, the authors isolated a summary RNA preparation from Ixodes persulcatus salivary gland extracts. Activity products of the genes responsible for the expression of some salivary proteins were first identified using the RT-PCR. It has been shown that, firstly, I. persulcatus synthesizes at least 3 transcripts homologous to the respective salivary components of the related species I. scapularis, the translation product of which is likely to be immunodominant antigens; secondly, the number of each of these transcripts, as in I. scapularis, depends on the stage of tick feeding. The changes in the expression of each transcript are specific: monotonously increasing changes in Salp 17 and cyclic ones in Salp 16, and synthesis, only when the ticks are fully ingested, in Salp 25.

  4. Identification and Characterization of Anaplasma phagocytophilum Proteins Involved in Infection of the Tick Vector, Ixodes scapularis

    Czech Academy of Sciences Publication Activity Database

    Villar, M.; Ayllón, N.; Kocan, K.M.; Bonzón-Kulichenko, E.; Alberdi, P.; Blouin, E.F.; Weisheit, S.; Mateos-Hernández, L.; Cabezas-Cruz, A.; Bell-Sakyi, L.; Vancová, Marie; Bílý, Tomáš; Meyer, D.F.; Štěrba, Ján; Contreras, M.; Rudenko, Natalia; Grubhoffer, Libor; Vázquez, J.; de la Fuente, J.

    2015-01-01

    Roč. 10, č. 9 (2015), e0137237 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) 238511; European Commission(XE) 278976 Institutional support: RVO:60077344 Keywords : secretion system * outer membrane vesicles * gene expression Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.057, year: 2015

  5. The efficacy of repellents against Aedes, Anopheles, Culex and Ixodes spp. - a literature review.

    Science.gov (United States)

    Lupi, Eleonora; Hatz, Christoph; Schlagenhauf, Patricia

    2013-01-01

    Travellers are confronted with a variety of vector-borne threats. Is one type of repellent effective against all biting vectors? The aim of this review is to examine the literature, up to December 31st, 2012, regarding repellent efficacy. We searched PubMed for relevant papers. Repellents of interest were DEET, Icaridin as well as other piperidine-derived products (SS220), Insect Repellent (IR) 3535 (ethyl-butylacetyl-amino-propionat, EBAAP) and plant-derived products, including Citriodora (para-menthane-3,8-diol). As vectors, we considered the mosquito species Anopheles, Aedes and Culex as well as the tick species Ixodes. We selected only studies evaluating the protective efficacy of repellents on human skin. We reviewed a total of 102 publications. Repellents were evaluated regarding complete protection time or as percentage efficacy [%] in a time interval. We found no standardized study for tick bite prevention. Regarding Aedes, DEET at concentration of 20% or more, showed the best efficacy providing up to 10 h protection. Citriodora repellency against this mosquito genus was lower compared to the other products. Also between subspecies a difference could be observed: Ae. aegypti proved more difficult to repel than Ae. Albopictus. Fewer studies have been conducted on mosquito species Anopheles and Culex. The repellency profile against Anopheles species was similar for the four principal repellents of interest, providing on average 4-10 h of protection. Culex mosquitoes are easier to repel and all four repellents provided good protection. Few studies have been conducted on the tick species Ixodes. According to our results, the longest protection against Ixodes scapularis was provided by repellents containing IR3535, while DEET and commercial products containing Icaridin or PMD showed a better response than IR3535 against Ixodes ricinus. Many plant-based repellents provide only short duration protection. Adding vanillin 5% to plant-based repellents and to DEET

  6. The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis

    Science.gov (United States)

    Bodnar, James; Mortazavi, Bobak; Laurent, Timothy; Deason, Jeff; Thephavongsa, Khanhkeo; Zhong, Jianmin

    2015-01-01

    Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host’s fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS) required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis. PMID:26650541

  7. IMMUNOTHERAPY OF IXODES TICK BORRELIOSIS IN CHILDREN

    Directory of Open Access Journals (Sweden)

    A. A. Chernikova

    2017-01-01

    Full Text Available The article presents the basic information relating to the clinical and immunological features of ixodes tick-borne borreliosis in children living in the Primorsky region. Research objective: to to analyze the effectiveness of the inclusion to the treatment scheme meglumine acridon acetate (cycloferon in pills for the treatment of children with ixodes tick-borne borreliosis.The study included 55 children with ixodes tick-borne borreliosis at the age of 4–12 years: 25 children of the main group and 30 children of the comparison group who received traditional therapy. In the treatment scheme of children of the main group, the drug meglumine acridon acetate (cycloferon was included. The use of cycloferon in the complex therapy of patients with ixodes tick-borne borreliosis resulted in a reduction in the duration of the manifestation of the main clinical symptoms of the disease, facilitated the synthesis of serum interleukine IL-10 by blood cells and inhibited the production of interleukine-1α and γ-interferon, which led to a faster formation of Th1 / Th2 type Immune response. Positive dynamics during treatment persisted in the study of the catamnesis of the patients observed for 5 years after the disease. There were no cases of chronic ixodes tick-borne borreliosis. 

  8. Systems Biology of Tissue-Specific Response to Anaplasma phagocytophilum Reveals Differentiated Apoptosis in the Tick Vector Ixodes scapularis

    Czech Academy of Sciences Publication Activity Database

    Ayllón, N.; Villar, M.; Galindo, R. C.; Kocan, K.M.; Šíma, Radek; López, J.A.; Vázquez, J.; Alberdi, P.; Cabezas-Cruz, A.; Kopáček, Petr; de la Fuente, J.

    2015-01-01

    Roč. 11, č. 3 (2015), e1005120 ISSN 1553-7404 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GP13-12816P Institutional support: RVO:60077344 Keywords : gene expression * human neutrophils * cancer cells Subject RIV: EC - Immunology Impact factor: 6.661, year: 2015

  9. Outer surface protein B is critical for Borrelia burgdorferi adherence and survival within Ixodes ticks.

    Directory of Open Access Journals (Sweden)

    Girish Neelakanta

    2007-03-01

    Full Text Available Survival of Borrelia burgdorferi in ticks and mammals is facilitated, at least in part, by the selective expression of lipoproteins. Outer surface protein (Osp A participates in spirochete adherence to the tick gut. As ospB is expressed on a bicistronic operon with ospA, we have now investigated the role of OspB by generating an OspB-deficient B. burgdorferi and examining its phenotype throughout the spirochete life cycle. Similar to wild-type isolates, the OspB-deficient B. burgdorferi were able to readily infect and persist in mice. OspB-deficient B. burgdorferi were capable of migrating to the feeding ticks but had an impaired ability to adhere to the tick gut and survive within the vector. Furthermore, the OspB-deficient B. burgdorferi bound poorly to tick gut extracts. The complementation of the OspB-deficient spirochete in trans, with a wild-type copy of ospB gene, restored its ability to bind tick gut. Taken together, these data suggest that OspB has an important role within Ixodes scapularis and that B. burgdorferi relies upon multiple genes to efficiently persist in ticks.

  10. Comportamento de Aedes albopictus e de Ae. scapularis adultos (Diptera: Culicidae no Sudeste do Brasil Adults Aedes albopictus and Ae. scapularis behavior (Diptera: Culidae in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    2000-10-01

    Full Text Available OBJETIVO: Observar e comparar o comportamento das espécies de Aedes albopictus e de Ae. scapularis, na localidade de Pedrinhas, litoral sul do Estado de São Paulo, Brasil. MÉTODOS: As observações foram feitas de outubro de 1996 a janeiro de 2000. Foram realizadas coletas sistemáticas de formas adultas mediante a utilização de isca humana, aspirações ambientais e armadilha tipo Shannon. A domiciliação foi estimada pelo índice de Nuorteva e pela razão de sinantropia. RESULTADOS: Foram feitas 87 coletas diurnas, com a obtenção de 872 adultos fêmeas. As médias de Williams', multiplicadas por 100, foram de 118 e 21 para Ae. albopictus nos horários de 7h às 18h e de 18h às 20h, respectivamente. Quanto a Ae. scapularis, foram de 100 e 106 nos mesmos períodos. Esse último revelou pico de atividade crepuscular vespertina. Na aspiração de abrigos, obteve-se o total de 1.124 espécimens, dos quais 226 Ae. albopictus e 898 Ae. scapularis. O período de janeiro a maio correspondeu ao de maior rendimento para ambos os mosquitos. Quanto à armadilha de Shannon, as coletas realizadas na mata revelaram a ausência de Ae. albopictus. No que concerne à domiciliação, esse último mostrou os maiores valores de índices, enquanto Ae. scapularis revelou comportamento de tipo ubiquista. CONCLUSÕES: Os resultados confirmam outras observações, permitindo levantar hipóteses. Em relação a Ae. scapularis, sugere-se que possa existir fenômeno de diapausa das fêmeas no período verão-outono, a qual cessaria no inverno-primavera quando então a atividade seria retomada. Quanto a Ae. albopictus, os dados sugerem que se trata de população em processo adaptativo ao novo ambiente.OBJECTIVE: Aedes albopictus and Ae. scapularis were found living together in the Pedrinhas Village, Southeastern of São Paulo State, Brazil. This finding was a good opportunity to make observations about the mosquitoes' behavior. METHODS: From October 1996 to

  11. Microtomography of the Baltic amber tick Ixodes succineus reveals affinities with the modern Asian disease vector Ixodes ovatus

    Energy Technology Data Exchange (ETDEWEB)

    Dunlop, Jason A.; Apanaskevich, Dmitry A.; Lehmann, Jens; Hoffmann, René; Fusseis, Florian; Ehlke, Moritz; Zachow, Stefan; Xiao, Xianghui

    2016-10-10

    Background: Fossil ticks are extremely rare, whereby Ixodes succineus Weidner, 1964 from Eocene (ca. 44–49 Ma) Baltic amber is one of the oldest examples of a living hard tick genus (Ixodida: Ixodidae). Previous work suggested it was most closely related to the modern and widespread European sheep tick Ixodes ricinus (Linneaus, 1758). Results: Restudy using phase contrast synchrotron x-ray tomography yielded images of exceptional quality. These confirm the fossil’s referral to Ixodes Latreille, 1795, but the characters resolved here suggest instead affinities with the Asian subgenus Partipalpiger Hoogstraal et al., 1973 and its single living (and medically significant) species Ixodes ovatus Neumann, 1899. We redescribe the amber fossil here as Ixodes (Partipalpiger) succineus. Conclusions: Our data suggest that Ixodes ricinus is unlikely to be directly derived from Weidner’s amber species, but instead reveals that the Partipalpiger lineage was originally more widely distributed across the northern hemisphere. The closeness of Ixodes (P.) succineus to a living vector of a wide range of pathogens offers the potential to correlate its spatial and temporal position (northern Europe, nearly 50 million years ago) with the estimated origination dates of various tick-borne diseases.

  12. Anaplasma phagocytophilum increases the levels of histone modifying enzymes to inhibit cell apoptosis and facilitate pathogen infection in the tick vector Ixodes scapularis

    Czech Academy of Sciences Publication Activity Database

    Cabezas-Cruz, A.; Alberdi, P.; Ayllón, N.; Valdés, James J.; Pierce, R.; Villar, M.; de la Fuente, J.

    2016-01-01

    Roč. 11, č. 4 (2016), s. 303-319 ISSN 1559-2294 EU Projects: European Commission(XE) 278976 - ANTIGONE; European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : Anaplasma * epigenetic s * histone modifying enzyme * histone * pathogen * tick Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.394, year: 2016

  13. The effectiveness of permethrin-treated deer stations for control of the Lyme disease vector Ixodes scapularis on Cape Cod and the islands: a five year experiment

    Science.gov (United States)

    The use of animal host-targeted pesticide application to control blacklegged ticks, which transmit the Lyme disease bacterium between wildlife hosts and humans, is receiving increased attention as an approach to Lyme disease risk management. Included among the attractive features...

  14. Implications of climate change on the distribution of the tick vector Ixodes scapularis and risk for Lyme disease in the Texas-Mexico transboundary region

    Science.gov (United States)

    Disease risk maps are important tools that help ascertain the likelihood of exposure to specific infectious agents. Understanding how climate change may affect the suitability of habitats for ticks will improve the accuracy of risk maps of tick-borne pathogen transmission in humans and domestic anim...

  15. Acaricidal Treatment of White-Tailed Deer to Control Ixodes Scapularis (Acari: Ixodidae) in a New York Lyme Disease-Endemic Community

    Science.gov (United States)

    The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann) against ticks using the acaricide amitraz was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21–24 of the 4-Posters were distribut...

  16. The effectiveness of permethrin-treated deer stations for control of the Lyme disease vector Ixodes scapularis on Cape Cod and the Islands

    Science.gov (United States)

    The use of animal host-targeted pesticide application to control blacklegged ticks, which transmit the Lyme disease bacterium between wildlife hosts and humans, is receiving increased attention as an approach to Lyme disease risk management. Included among the attractive feature...

  17. Absence of Lyme disease spirochetes in larval ixodes ricinus ticks

    Czech Academy of Sciences Publication Activity Database

    Richter, D.; Debski, A.; Hubálek, Zdeněk; Matuschka, F.-R.

    2012-01-01

    Roč. 12, č. 1 (2012), s. 21-27 ISSN 1530-3667 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : blood meal * Borrelia * Ixodes * Lyme disease * Vertical transmission Subject RIV: EE - Microbiology, Virology Impact factor: 2.277, year: 2012

  18. The extensible alloscutal cuticle of the tick, Ixodes ricinus

    DEFF Research Database (Denmark)

    Andersen, Svend Olav; Roepstorff, Peter

    2005-01-01

    The proteins in the distensible alloscutal cuticle of the blood-feeding tick, Ixodes ricinus, have been characterized by electrophoresis and chromatography, two of the proteins were purified and their total amino acid sequence determined. They show sequence similarity to cuticular proteins from t...

  19. Rickettsiae in questing Ixodes ricinus ticks in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Venclíková, Kristýna; Rudolf, Ivo; Mendel, Jan; Betášová, Lenka; Hubálek, Zdeněk

    2014-01-01

    Roč. 5, č. 2 (2014), s. 135-138 ISSN 1877-959X Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Anaplasma phagocytophilum * Rickettsia spp. * Rickettsia helvetica * Rickettsia monacensis * Candidatus Neoehrlichia mikurensis Subject RIV: EE - Microbiology, Virology Impact factor: 2.718, year: 2014

  20. Exotic Rickettsiae in Ixodes ricinus: fact or artifact?

    NARCIS (Netherlands)

    Tijsse-Klasen, E.; Fonville, M.; Overbeek, van L.S.; Reimerink, J.H.J.; Sprong, H.

    2010-01-01

    Several pathogenic Rickettsia species can be transmitted via Ixodes ricinus ticks to humans and animals. Surveys of I. ricinus for the presence of Rickettsiae using part of its 16S rRNA gene yield a plethora of new and different Rickettsia sequences. Interpreting these data is sometimes difficult

  1. Borreliae in Ixodes ricinus ticks feeding on humans

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina

    2004-01-01

    Roč. 18, č. 3 (2004), s. 228-231 ISSN 0269-283X R&D Projects: GA ČR GA206/03/0726; GA AV ČR IBS6093007 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Ixodes ricinus * Lyme disease Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.405, year: 2004

  2. Longitudinal surveillance of the tick Ixodes ricinus for borreliae

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina

    2003-01-01

    Roč. 17, č. 1 (2003), s. 46-51 ISSN 0269-283X R&D Projects: GA ČR GA206/00/1204; GA AV ČR IBS6093007 Institutional research plan: CEZ:AV0Z6093917 Keywords : Borrelia burgdorferi * Ixodes ricinus * Lyme disease Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.040, year: 2003

  3. Ixodes ricinus defensins attack distantly-related pathogens

    Czech Academy of Sciences Publication Activity Database

    Tonk, M.; Cabezas-Cruz, A.; Valdés, James J.; Rego, Ryan O. M.; Grubhoffer, Libor; Estrada--Pena, A.; Vilcinskas, A.; Kotsyfakis, Michalis; Rahnamaeian, M.

    2015-01-01

    Roč. 53, č. 2 (2015), s. 358-365 ISSN 0145-305X R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GAP502/12/2409 EU Projects: European Commission(XE) 278976 Institutional support: RVO:60077344 Keywords : Antimicrobial peptide * Defensin * Ixodes ricinus * Listeria monocytogenes * Staphylococcus aureus * Staphylococcus epidermidis * Escherichia coli * Pseudomonas aeruginosa * Fusarium spp Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.620, year: 2015

  4. Prevalence of tick-borne pathogens in questing Ixodes ricinus ticks in urban and suburban areas of Switzerland

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    Corinne P. Oechslin

    2017-11-01

    Full Text Available Abstract Background Throughout Europe, Ixodes ricinus transmits numerous pathogens. Its widespread distribution is not limited to rural but also includes urbanized areas. To date, comprehensive data on pathogen carrier rates of I. ricinus ticks in urban areas of Switzerland is lacking. Results Ixodes ricinus ticks sampled at 18 (sub- urban collection sites throughout Switzerland showed carrier rates of 0% for tick-borne encephalitis virus, 18.0% for Borrelia burgdorferi (sensu lato, 2.5% for Borrelia miyamotoi, 13.5% for Rickettsia spp., 1.4% for Anaplasma phagocytophilum, 6.2% for "Candidatus Neoehrlichia mikurensis", and 0.8% for Babesia venatorum (Babesia sp., EU1. Site-specific prevalence at collection sites with n > 45 ticks (n = 9 significantly differed for B. burgdorferi (s.l., Rickettsia spp., and "Ca. N. mikurensis", but were not related to the habitat type. Three hundred fifty eight out of 1078 I. ricinus ticks (33.2% tested positive for at least one pathogen. Thereof, about 20% (71/358 were carrying two or three different potentially disease-causing agents. Using next generation sequencing, we could detect true pathogens, tick symbionts and organisms of environmental or human origin in ten selected samples. Conclusions Our data document the presence of pathogens in the (sub- urban I. ricinus tick population in Switzerland, with carrier rates as high as those in rural regions. Carriage of multiple pathogens was repeatedly observed, demonstrating the risk of acquiring multiple infections as a consequence of a tick bite.

  5. Anaplasma phagocytophilum in questing Ixodes ricinus ticks from Romania.

    Science.gov (United States)

    Matei, Ioana Adriana; Kalmár, Zsuzsa; Magdaş, Cristian; Magdaş, Virginia; Toriay, Hortenzia; Dumitrache, Mirabela Oana; Ionică, Angela Monica; D'Amico, Gianluca; Sándor, Attila D; Mărcuţan, Daniel Ioan; Domşa, Cristian; Gherman, Călin Mircea; Mihalca, Andrei Daniel

    2015-04-01

    Granulocytic anaplasmosis is a common vector-borne disease of humans and animals with natural transmission cycle that involves tick vectors, among which Ixodes ricinus is the most important. The present paper reports the prevalence and geographical distribution of A. phagocytophilum in 10,438 questing Ixodes ricinus ticks collected at 113 locations from 40 counties of Romania. The unfed ticks were examined for the presence of A. phagocytophilum by PCR targeting a portion of ankA gene. The overall prevalence of infection was 3.42%, with local prevalences ranging between 0.29% and 22.45%, with an average prevalence of 5.39% in the infected localities. The infection with A. phagocytophilum was detected in 72 out of 113 localities and in 34 out of 40 counties. The highest prevalence was recorded in females followed by males and nymphs. The results and the distribution model have shown a large distribution of A. phagocytophilum, covering Romania's entire territory. This study is the first large scale survey of the presence of A. phagocytophilum in questing I. ricinus ticks from Romania. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Climate change and Ixodes tick-borne diseases of humans.

    Science.gov (United States)

    Ostfeld, Richard S; Brunner, Jesse L

    2015-04-05

    The evidence that climate warming is changing the distribution of Ixodes ticks and the pathogens they transmit is reviewed and evaluated. The primary approaches are either phenomenological, which typically assume that climate alone limits current and future distributions, or mechanistic, asking which tick-demographic parameters are affected by specific abiotic conditions. Both approaches have promise but are severely limited when applied separately. For instance, phenomenological approaches (e.g. climate envelope models) often select abiotic variables arbitrarily and produce results that can be hard to interpret biologically. On the other hand, although laboratory studies demonstrate strict temperature and humidity thresholds for tick survival, these limits rarely apply to field situations. Similarly, no studies address the influence of abiotic conditions on more than a few life stages, transitions or demographic processes, preventing comprehensive assessments. Nevertheless, despite their divergent approaches, both mechanistic and phenomenological models suggest dramatic range expansions of Ixodes ticks and tick-borne disease as the climate warms. The predicted distributions, however, vary strongly with the models' assumptions, which are rarely tested against reasonable alternatives. These inconsistencies, limited data about key tick-demographic and climatic processes and only limited incorporation of non-climatic processes have weakened the application of this rich area of research to public health policy or actions. We urge further investigation of the influence of climate on vertebrate hosts and tick-borne pathogen dynamics. In addition, testing model assumptions and mechanisms in a range of natural contexts and comparing their relative importance as competing models in a rigorous statistical framework will significantly advance our understanding of how climate change will alter the distribution, dynamics and risk of tick-borne disease.

  7. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    evaluating the deployment repeatability builds upon the testing or analysis of deployment kinematics (Chapter 6) and adds repetition. Introduction...material yield or failure during a test. For the purposes of this chapter, zero shift will refer to permanent changes in the structure, while reversible ...the content of other chapters in this book: Gravity Compensation (Chapter 4) and Deployment Kinematics and Dynamics (Chapter 6). Repeating the

  8. Biting activity of Aedes scapularis (Rondani and Haemagogus mosquitoes in Southern Brazil (Diptera: Culicidae Atividade hematófaga de mosquitos Aedes scapularis (Rondani e Haemagogus no sul do Brasil (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1988-04-01

    Full Text Available The biting activity of a population of Aedes scapularis (Rondani, Haemagogus capricornii Lutz and Hg. leucocelaenus (Dyar and Shannon in Southern Brazil was studied between March 1980 and April 1983. Data were obtained with 25-hour human bait catches in three areas with patchy residual forests, named "Jacaré-Pepira", "Lupo" Farm, and "Sta. Helena" Farm, in the highland region of S. Paulo State (Brazil. Data obtained on Ae. scapularis were compared with those formerly gathered in the "Ribeira'' Valley lowlands, and were similar, except in the "Lupo" Farm study area, where a precrepuscular peak was observed, not recorded at the "Jacaré-Pepira" site or in the "Ribeira" Valley. In all the areas this mosquito showed diurnal and nocturnal activity, but was most active during the evening crepuscular period. These observations support the hypothesis about the successful adaptation of Ae. scapularis to man-made environments and have epidemiological implications that arise from it. As for Haemagogus, results obtained on the "Lupo" and "Sta. Helena" regions agree with previous data obtained in several other regions and show its diurnal activity. The proximity of "Lupo" Farm, where Hg. capricornii and Hg. leucocelaenus showed considerable activity, to "Araraquara" city where Aedes aegypti was recently found, raises some epidemiological considerations about the possibility of urban yellow fever resurgence.No período de março de 1980 a abril de 1983 foi estudada a atividade hematófaga de uma população de Aedes scapularis (Rondani, Haemagogus capricornii Lutz, Hg. leucocelaenus (Dyar e Shannon, na região sul do Brasil. Os dados foram obtidos com o emprego de isca humana, mediante captura de 25 horas de duração e correspondente a três áreas, contendo manchas de floresta residual, denominadas Jacaré-Pepira, Fazenda Lupo e Fazenda Santa Helena. Os resultados relativos a Ae. scapularis foram comparados com as coletas anteriormente feitas em áreas de

  9. Comparative Metagenomic Profiling of Symbiotic Bacterial Communities Associated with Ixodes persulcatus, Ixodes pavlovskyi and Dermacentor reticulatus Ticks.

    Science.gov (United States)

    Kurilshikov, Alexander; Livanova, Natalya N; Fomenko, Nataliya V; Tupikin, Alexey E; Rar, Vera A; Kabilov, Marsel R; Livanov, Stanislav G; Tikunova, Nina V

    2015-01-01

    Ixodes persulcatus, Ixodes pavlovskyi, and Dermacentor reticulatus ticks inhabiting Western Siberia are responsible for the transmission of a number of etiological agents that cause human and animal tick-borne diseases. Because these ticks are abundant in the suburbs of large cities, agricultural areas, and popular tourist sites and frequently attack people and livestock, data regarding the microbiomes of these organisms are required. Using metagenomic 16S profiling, we evaluate bacterial communities associated with I. persulcatus, I. pavlovskyi, and D. reticulatus ticks collected from the Novosibirsk region of Russia. A total of 1214 ticks were used for this study. DNA extracted from the ticks was pooled according to tick species and sex. Sequencing of the V3-V5 domains of 16S rRNA genes was performed using the Illumina Miseq platform. The following bacterial genera were prevalent in the examined communities: Acinetobacter (all three tick species), Rickettsia (I. persulcatus and D. reticulatus) and Francisella (D. reticulatus). B. burgdorferi sensu lato and B. miyamotoi sequences were detected in I. persulcatus and I. pavlovskyi but not in D. reticulatus ticks. The pooled samples of all tick species studied contained bacteria from the Anaplasmataceae family, although their occurrence was low. DNA from A. phagocytophilum and Candidatus Neoehrlichia mikurensis was first observed in I. pavlovskyi ticks. Significant inter-species differences in the number of bacterial taxa as well as intra-species diversity related to tick sex were observed. The bacterial communities associated with the I. pavlovskyi ticks displayed a higher biodiversity compared with those of the I. persulcatus and D. reticulatus ticks. Bacterial community structure was also diverse across the studied tick species, as shown by permutational analysis of variance using the Bray-Curtis dissimilarity metric (p = 0.002). Between-sex variation was confirmed by PERMANOVA testing in I. persulcatus (p = 0

  10. Comparative Metagenomic Profiling of Symbiotic Bacterial Communities Associated with Ixodes persulcatus, Ixodes pavlovskyi and Dermacentor reticulatus Ticks.

    Directory of Open Access Journals (Sweden)

    Alexander Kurilshikov

    Full Text Available Ixodes persulcatus, Ixodes pavlovskyi, and Dermacentor reticulatus ticks inhabiting Western Siberia are responsible for the transmission of a number of etiological agents that cause human and animal tick-borne diseases. Because these ticks are abundant in the suburbs of large cities, agricultural areas, and popular tourist sites and frequently attack people and livestock, data regarding the microbiomes of these organisms are required. Using metagenomic 16S profiling, we evaluate bacterial communities associated with I. persulcatus, I. pavlovskyi, and D. reticulatus ticks collected from the Novosibirsk region of Russia. A total of 1214 ticks were used for this study. DNA extracted from the ticks was pooled according to tick species and sex. Sequencing of the V3-V5 domains of 16S rRNA genes was performed using the Illumina Miseq platform. The following bacterial genera were prevalent in the examined communities: Acinetobacter (all three tick species, Rickettsia (I. persulcatus and D. reticulatus and Francisella (D. reticulatus. B. burgdorferi sensu lato and B. miyamotoi sequences were detected in I. persulcatus and I. pavlovskyi but not in D. reticulatus ticks. The pooled samples of all tick species studied contained bacteria from the Anaplasmataceae family, although their occurrence was low. DNA from A. phagocytophilum and Candidatus Neoehrlichia mikurensis was first observed in I. pavlovskyi ticks. Significant inter-species differences in the number of bacterial taxa as well as intra-species diversity related to tick sex were observed. The bacterial communities associated with the I. pavlovskyi ticks displayed a higher biodiversity compared with those of the I. persulcatus and D. reticulatus ticks. Bacterial community structure was also diverse across the studied tick species, as shown by permutational analysis of variance using the Bray-Curtis dissimilarity metric (p = 0.002. Between-sex variation was confirmed by PERMANOVA testing in I

  11. Experimental evidence against transmission of Hepatozoon canis by Ixodes ricinus.

    Science.gov (United States)

    Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Dantas-Torres, Filipe; Mencke, Norbert; Baneth, Gad; Otranto, Domenico

    2013-09-01

    Hepatozoon canis is among the most widespread tick-borne protozoa infecting domestic and wild carnivores. Its distribution is related to the occurrence of its major vector, the brown dog tick Rhipicephalus sanguineus. However, the role of Ixodes ricinus as a vector of H. canis has been hypothesized. In the present study, the development of H. canis was investigated in I. ricinus and R. sanguineus nymphs collected from a naturally infested dog. All I. ricinus ticks examined (n=133) were negative by cytological examination at days 20, 30, and 90 post collection, although H. canis DNA was detected in one nymph at day 20 and in 2 nymphs at day 30 post collection. On the other hand, H. canis sporogony was documented by cytology, and H. canis DNA was detected by PCR in R. sanguineus at day 30 post collection. These results indicate that H. canis sporogony does not occur in I. ricinus, but in R. sanguineus, suggesting that I. ricinus does not act as a vector of H. canis. Copyright © 2013 Elsevier GmbH. All rights reserved.

  12. Repeating Marx

    DEFF Research Database (Denmark)

    Fuchs, Christian; Monticelli, Lara

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

  13. Deployment Repeatability

    Science.gov (United States)

    2016-08-31

    large cohort of trials to spot unusual cases. However, deployment repeatability is inherently a nonlinear phenomenon, which makes modeling difficult...and GEMS tip position were both tracked during ground testing by a laser target tracking system. Earlier SAILMAST testing in 2005 [8] used...recalls the strategy used by SRTM, where a constellation of lights was installed at the tip of the boom and a modified star tracker was used to track tip

  14. Genetic Diversity of Salp15 in the Ixodes ricinus Complex (Acari: Ixodidae)

    OpenAIRE

    Wang, Xin; Huang, Yong; Niu, Si-bo; Jiang, Bao-Gui; Jia, Na; van der Geest, Leo; Ni, Xue-bing; Sun, Yi; Cao, Wu-Chun

    2014-01-01

    Salp15, a 15-kDa tick salivary gland protein, is both essential for ticks to successfully obtain host blood and also facilitates transmission of Lyme borreliosis. To determine whether the Salp15 gene is expressed in Ixodes persulcatus and Ixodes sinensis, principle vectors of Lyme borreliosis in China, we studied transcriptions of this gene in semi-engorged larvae, nymph and adults of these two species. A total of eight Salp15 homologues, five in I. persulcatus and three in I. sinensis, were ...

  15. Diversity of Babesia in Ixodes ricinus ticks in Poland.

    Science.gov (United States)

    Welc-Falęciak, R; Bajer, A; Paziewska-Harris, A; Baumann-Popczyk, A; Siński, E

    2012-01-01

    The aims of this study were: (1) to estimate Babesia prevalence in the most common species of tick in Poland, Ixodes ricinus, in two recreational areas (Urwitałt in the Mazury Lake District and Bielański Forest in Warsaw), and (2) to evaluate the molecular diversity of Babesia isolates in questing I. ricinus in Poland. Questing ticks were collected from vegetation in forest areas in Urwitałt near Mikołajki and in Bielański Forest (Warsaw). Purified genomic DNA was used with specific primers to amplify a fragment of the Babesia spp. 18S rRNA gene. Tick-drag indices for I. ricinus were high in both study areas, reaching somewhat higher values in Urwitałt than in Bielański Forest. The overall prevalence of Babesia spp. in examined ticks was 1.6%. In Urwitałt, two strains of B. microti were identified using rRNA sequences: the enzootic Munich strain and an isolate close to the zoonotic Jena strain. The proportion of infections due to these two strains in questing ticks reversed over a six-year period. During 3 years of study in Bielański Forest, all Babesia isolates obtained from I. ricinus were identical to Babesia sp. EU1 (B. venatorum), previously recognized as an agent of human babesiosis. This study has confirmed the presence of enzoonotic and zoonotic Babesia species/strains in the abundant human-biting tick I. ricinus in recreational areas in Poland. It has also shown that the distribution of different genotypes has changed over time, however the reasons for these fluctuations still remain to be investigated.

  16. Ultrastructure and lectin characterization of granular salivary cells from Ixodes ricinus females

    Czech Academy of Sciences Publication Activity Database

    Vancová, Marie; Zacharovová, Klára; Grubhoffer, Libor; Nebesářová, Jana

    2006-01-01

    Roč. 92, č. 3 (2006), s. 431-440 ISSN 0022-3395 R&D Projects: GA ČR GA206/03/1323 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * salivary glands * lectin labeling Subject RIV: EE - Microbiology, Virology Impact factor: 1.300, year: 2006

  17. Molecular identification of hard ticks (Ixodes sp.) infesting rodents in Selangor, Malaysia

    Science.gov (United States)

    Ishak, Siti Nabilah; Shiang, Lim Fang; Taib, Farah Shafawati Mohd; Jing, Khoo Jing; Nor, Shukor Md; Yusof, Muhammad Afif; Sah, Shahrul Anuar Mohd; Sitam, Frankie Thomas; Japning, Jeffrine Rovie Ryan

    2018-04-01

    This study aims to identify hard ticks (Ixodes sp.) infesting rodents in three different sites in Selangor, Malaysia using a molecular approach. A total of 11 individual ticks infesting four different host species (Rattus tiomanicus, Rattus ratus, Maxomys surifer and Sundamys muelleri) were examined based on its morphological features, followed by molecular identification using mitochondrial 16S rDNA gene. Confirmation of the species identity was accomplished by using BLAST program. Clustering analysis based on 16S rDNA sequences was carried out by constructing Neighbour-joining (NJ) and Maximum parsimony (MP) tree using MEGA 7 to clarify the genetic identity of Ixodes sp. Based on morphological features, all individual ticks were only able to be identified up to genus level as most of the samples were fully engorged, damaged and lacked morphological characters. However, molecular analysis of samples revealed 99% similarity with Ixodes granulatus from the GenBank database. Thus, the result of this study showed that all these ticks (Ixodes granulatus) were genetically affiliated to a monophyletic group with highly homogenous sequences.

  18. An Ehrlichia strain from a llama (Lama glama) and Llama-associated ticks (Ixodes pacificus).

    Science.gov (United States)

    Barlough, J E; Madigan, J E; Turoff, D R; Clover, J R; Shelly, S M; Dumler, J S

    1997-01-01

    An ehrlichia was identified in the blood of a diseased llama (lama glama). Sequencing of its 16S rRNA gene showed the ehrlichia to be closely related to members of the Ehrlichia phagocytophila genogroup. The agent was also found in a pool of ticks (Ixodes pacificus) collected at the llama site. PMID:9157118

  19. Differential expression of Ixodes ricinus tick genes induced by blood feeding or Borrelia burgdorferi infection

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Edwards, M. J.; Grubhoffer, Libor

    2005-01-01

    Roč. 42, č. 1 (2005), s. 36-41 ISSN 0022-2585 R&D Projects: GA AV ČR IAA6022306 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Borrelia burgdorferi * subtractive hybridization Subject RIV: EE - Microbiology, Virology Impact factor: 1.489, year: 2005

  20. Occurrence of multiple infections with different Borrelia burgdorferi genospecies in Danish Ixodes ricinus nymphs

    DEFF Research Database (Denmark)

    Andersen, Jean Vennestrøm; Egholm, H.; Mikkelsen, Per Jensen

    2008-01-01

    The pathogen Borrelia burgdorferi causes Lyme Borreliosis in human and animals world-wide. In Europe the pathogen is transmitted to the host by the vector Ixodes ricinus. The nymph is the primary instar for transmission to humans. We here study the infection rate of five Borrelia genospecies: B...

  1. Ixodes ricinus tick saliva modulates tick-borne encephalitis virus infection of dendritic cells

    Czech Academy of Sciences Publication Activity Database

    Fialová, Anna; Cimburek, Zdeněk; Iezzi, G.; Kopecký, Jan

    2010-01-01

    Roč. 12, č. 7 (2010), s. 580-585 ISSN 1286-4579 R&D Projects: GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z50200510 Keywords : Tick-borne encephalitis virus * Dendritic cell * Tick saliva * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.726, year: 2010

  2. Seasonal correlation of sporadic schizophrenia to Ixodes ticks and Lyme borreliosis

    Directory of Open Access Journals (Sweden)

    Fritzsche Markus

    2002-11-01

    Full Text Available Abstract Background Being born in winter and spring is considered one of the most robust epidemiological risk factors for schizophrenia. The aetiology and exact timing of this birth excess, however, has remained elusive so far. Since during phylogeny, Borrelia DNA has led to multiple germ-line mutations within the CB1 candidate gene for schizophrenia, a meta analysis has been performed of all papers on schizophrenic birth excesses with no less than 3000 cases each. All published numerical data were then plotted against the seasonal distributions of Ixodes ticks worldwide. Results In the United States, Europe and Japan the birth excesses of those individuals who later in life develop schizophrenia mirror the seasonal distribution of Ixodes ticks nine months earlier at the time of conception. South of the Wallace Line, which limits the spread of Ixodes ticks and Borrelia burgdorferi into Australia, seasonal trends are less significant, and in Singapore, being non-endemic for Ixodes ticks and Lyme disease, schizophrenic birth excesses are absent. Conclusion At present, it cannot be excluded that prenatal infection by B. burgdorferi is harmful to the implanting human blastocyst. The epidemiological clustering of sporadic schizophrenia by season and locality rather emphasises the risk to the unborn of developing a congenital, yet preventable brain disorder later in life.

  3. Babesia sp. EU1 from Roe Deer and Transmission within Ixodes ricinus

    Science.gov (United States)

    Jouglin, Maggy; L’Hostis, Monique; Chauvin, Alain

    2007-01-01

    We report in vitro culture of zoonotic Babesia sp. EU1 from blood samples of roe deer in France. This study provides evidence of transovarial and transstadial transmission of the parasite within Ixodes ricinus, which suggests that this tick could be a vector and reservoir of EU1. PMID:17953093

  4. Vaccination against Bm86 Homologues in Rabbits Does Not Impair Ixodes ricinus Feeding or Oviposition

    NARCIS (Netherlands)

    Coumou, Jeroen; Wagemakers, Alex; Trentelman, Jos J.; Nijhof, Ard M.; Hovius, Joppe W.

    2014-01-01

    Human tick-borne diseases that are transmitted by Ixodes ricinus, such as Lyme borreliosis and tick borne encephalitis, are on the rise in Europe. Diminishing I. ricinus populations in nature can reduce tick exposure to humans, and one way to do so is by developing an anti-vector vaccine against

  5. Human pathogenic borreliae in Ixodes ricinus ticks in natural and urban ecosystem (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Venclíková, Kristýna; Betášová, Lenka; Šikutová, Silvie; Jedličková, Petra; Hubálek, Zdeněk; Rudolf, Ivo

    2014-01-01

    Roč. 59, č. 4 (2014), s. 717-720 ISSN 1230-2821 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Ixodes ricinus * Borrelia burgdorgeri s.l. * genomic species * ixodid ticks Subject RIV: EE - Microbiology, Virology Impact factor: 0.905, year: 2014

  6. First detection of Borrelia miyamotoi in Ixodes ricinus ticks from northern Italy.

    NARCIS (Netherlands)

    Ravagnan, Silvia; Tomassone, Laura; Montarsi, Fabrizio; Krawczyk, Aleksandra Iwona; Mastrorilli, Eleonora; Sprong, Hein; Milani, Adelaide; Rossi, Luca; Capelli, Gioia

    2018-01-01

    Borrelia miyamotoi is a spirochete transmitted by several ixodid tick species. It causes a relapsing fever in humans and is currently considered as an emerging pathogen. In Europe, B. miyamotoi seems to occur at low prevalence in Ixodes ricinus ticks but has a wide distribution. Here we report the

  7. Behavioural responses of Ixodes ricinus nymphs to carbon dioxide and rodent odour

    NARCIS (Netherlands)

    Duijvendijk, van G.; Gort, G.; Sprong, H.; Takken, W.

    2017-01-01

    Many haematophagous ectoparasites use carbon dioxide (CO2) and host odour to detect and locate their hosts. The tick Ixodes ricinus (Linnaeus) (Ixodida: Ixodidae) walks only small distances and quests in vegetation until it encounters a host. The differential effects of CO2 and host odour on the

  8. The crystal structures of two salivary cystatins from the tick Ixodes scapularis and the effect of these inhibitors on the establishment of Borrelia burgdorferi infection in a murine model

    Czech Academy of Sciences Publication Activity Database

    Kotsyfakis, Michalis; Horká, Helena; Salát, Jiří; Andersen, J. F.

    2010-01-01

    Roč. 77, č. 2 (2010), s. 456-470 ISSN 0950-382X R&D Projects: GA AV ČR KJB500960702; GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60220518 Keywords : INVARIANT CHAIN FRAGMENT * EGG-WHITE CYSTATIN * CATHEPSIN-L * CYSTEINE PROTEINASES * SIALOSTATIN-L * ENDOPEPTIDASE Subject RIV: EC - Immunology Impact factor: 4.819, year: 2010

  9. THE ANALYSIS OF IXODES TICKS INFESTATION WITH TBEV IN KIROV REGION

    Directory of Open Access Journals (Sweden)

    E. A. Bessolitsyna

    2014-01-01

    Full Text Available The objects of this study are Ixodes ticks which were collected in different areas of Kirov province. The aim of the study is to determine the proportion of TBEV infected ticks using the reverse transcription and PCR, dependingon time, place, and methods of collection in the Kirov province as well as of ticks specific and sexual identity. The study found that from the two tick species that were tested only taiga tick (Ixodes persulcatus but not the meadow thick (Dermacentor reticulatus was the TBEV vector. Study also has shown that both males and females ticks can be the TBEV vectors. Moreover, it was proved the importance of ticks testing which were gathered not only from human but also from animals, primary from dogs, and from the plants.

  10. Ixodes ricinus as vector and reservoir of Borrelia burgdorferi in an urban environment

    Directory of Open Access Journals (Sweden)

    Rajković Dragana V.

    2005-01-01

    Full Text Available As specific arthropods, ticks in urban environments transmit the agents of dangerous contagious diseases endangering human and animal health. They are vectors of numerous infective agents that cause serious diseases of animals such as babesiosis and ehrlichiosis. Tick populations maintain and transmit an increas­ing number of different infective agents. In regard to the human population, they transmit the agents of tick encephalitis, Omsk hemorrhagic disease, Crim-Congo hemorrhagic disease, Kyasa-nur forest fever, ixodid fever, Q fever, Rocky Mountain spotted fever, tularemia, Siberian tick typhus and Lyme disease the last of which according to acarological references has become the dominant zoonosis in over 140 of the world's countries. In urban environments ticks represent problem both for their epidemiological significance and as organisms whose presence disturbs people during their work and rest. In Europe, the two most fre­quent species and Ixodes ricinus and Ixodes persulcatus. Both species have a wide spectrum of hosts.

  11. Babesia microti (Piroplasmida: Babesiidae) in nymphal Ixodes ricinus (Acari: Ixodidae) in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Golovchenko, Maryna; Šikutová, Silvie; Rudenko, Natalia; Grubhoffer, Libor; Hubálek, Zdeněk

    2005-01-01

    Roč. 52, č. 3 (2005), s. 274-276 ISSN 0015-5683 R&D Projects: GA ČR(CZ) GA206/03/0726 Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z60220518 Keywords : Babesia microti * Ixodes ricinus Subject RIV: EE - Microbiology, Virology Impact factor: 1.138, year: 2005 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=20766

  12. Optimization of the solid-phase microextraction method in the determination of Ixodes ricinus (L.) volatiles

    Czech Academy of Sciences Publication Activity Database

    Zahradníčková, Helena; Bouman, Edwin Arien Poul

    2006-01-01

    Roč. 29, č. 2 (2006), s. 236-241 ISSN 1615-9306 R&D Projects: GA ČR(CZ) GA206/04/0751 Institutional research plan: CEZ:AV0Z50070508; CEZ:AV0Z60220518 Keywords : GC/MS * Ixodes ricinus * solid-phase microextraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.535, year: 2006

  13. Experimental inoculation of beagle dogs with Ehrlichia species detected from Ixodes ovatus

    OpenAIRE

    Watanabe, Malaika; Oikawa, T; Hiraoka, Hiroko; Kaneko, N; Itamoto, Kazuhito; Mizuno, Tohru; Okuda, Masaru; Inokuma, Hisashi

    2006-01-01

    Three beagle dogs were inoculated with mice spleen/liver homogenate infected with Ehrlichia species detected from Ixodes ovatus (EIO) and one dog was used as a control. All three infected dogs did not show clinical signs of disease except for mild pyrexia throughout the 41-day study period. Splenomegaly was observed from Day 7 post-inoculation (p.i.) in two of the dogs. Hematological and biochemical abnormalities included mild thrombocytopenia, hypoproteinaemia, hypoalbuminaemia and increased...

  14. Identification and partial characterisation of new members of the Ixodes ricinus defensin family

    Czech Academy of Sciences Publication Activity Database

    Tonk, Miray; Cabezas Cruz, Alejandro; Valdés, James J.; Rego, Ryan O. M.; Rudenko, Natalia; Golovchenko, Maryna; Bell-Sakyi, L.; de la Fuente, J.; Grubhoffer, Libor

    2014-01-01

    Roč. 540, č. 2 (2014), s. 146-152 ISSN 0378-1119 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : antimicrobial peptide * defensin * Ixodes ricinus * tick * tick cell line Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.138, year: 2014

  15. [Characteristics of the distribution of Ixodes persulcatus in the forest-park area of Novosibirsk].

    Science.gov (United States)

    Sapegina, V F; Dorontsova, V A; Telegin, V I; Ibleva, N G; Dobrotvorskiĭ, A K

    1985-01-01

    Only one species of ixodid ticks Ixodes persulcatus occurs in the forest-park zone. Conditions of foliage forests with high grass, where occur hosts of all developmental phases of ticks (elks, hares, rodents, insectivores), are most favourable for I. persulcatus. Preimaginal phases of I. persulcatus feed, in general, on dominant species (common shrew, redbacked and narrow-skulled voles, field mouse and northern birch mouse).

  16. NCBI nr-aa BLAST: CBRC-MDOM-02-0026 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MDOM-02-0026 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 5e-51 48% ...

  17. NCBI nr-aa BLAST: CBRC-PVAM-01-1566 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-PVAM-01-1566 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 4e-13 42% ...

  18. NCBI nr-aa BLAST: CBRC-GGOR-01-1493 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-GGOR-01-1493 ref|XP_002416287.1| glycine rich secreted cement protein, putativ...e [Ixodes scapularis] gb|EEC19954.1| glycine rich secreted cement protein, putative [Ixodes scapularis] XP_002416287.1 7e-28 46% ...

  19. Genetic variability of Rickettsia spp. in Ixodes persulcatus/Ixodes trianguliceps sympatric areas from Western Siberia, Russia: Identification of a new Candidatus Rickettsia species.

    Science.gov (United States)

    Igolkina, Yana P; Rar, Vera A; Yakimenko, Valeriy V; Malkova, Marina G; Tancev, Aleksey K; Tikunov, Artem Yu; Epikhina, Tamara I; Tikunova, Nina V

    2015-08-01

    Rickettsia spp. are the causative agents of a number of diseases in humans. These bacteria are transmitted by arthropods, including ixodid ticks. DNA of several Rickettsia spp. was identified in Ixodes persulcatus ticks, however, the association of Ixodes trianguliceps ticks with Rickettsia spp. is unknown. In our study, blood samples of small mammals (n=108), unfed adult I. persulcatus ticks (n=136), and I. persulcatus (n=12) and I. trianguliceps (n=34) ticks feeding on voles were collected in two I. persulcatus/I. trianguliceps sympatric areas in Western Siberia. Using nested PCR, ticks and blood samples were studied for the presence of Rickettsia spp. Three distinct Rickettsia species were found in ticks, but no Rickettsia species were found in the blood of examined voles. Candidatus Rickettsia tarasevichiae DNA was detected in 89.7% of unfed I. persulcatus, 91.7% of engorged I. persulcatus and 14.7% of I. trianguliceps ticks. Rickettsia helvetica DNA was detected in 5.9% of I. trianguliceps ticks. In addition, a new Rickettsia genetic variant was found in 32.4% of I. trianguliceps ticks. Sequence analysis of the 16S rRNA, gltA, ompA, оmpB and sca4 genes was performed and, in accordance with genetic criteria, a new Rickettsia genetic variant was classified as a new Candidatus Rickettsia species. We propose to name this species Candidatus Rickettsia uralica, according to the territory where this species was initially identified. Candidatus Rickettsia uralica was found to belong to the spotted fever group. The data obtained in this study leads us to propose that Candidatus Rickettsia uralica is associated with I. trianguliceps ticks. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution

    Science.gov (United States)

    2010-01-01

    Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969). Note. The tick from Valle de Bravo, Estado de México, was...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la Investigación (PROFIP). Tila María Pérez, Curator of CNAC

  1. Functional characterization of two defensin isoforms of the hard tick Ixodes ricinus

    Czech Academy of Sciences Publication Activity Database

    Chrudimská, Tereza; Slaninová, Jiřina; Rudenko, Natalia; Růžek, Daniel; Grubhoffer, Libor

    2011-01-01

    Roč. 4, č. 1 (2011), e63 ISSN 1756-3305 R&D Projects: GA MŠk(CZ) LC06009; GA ČR GA206/09/1782; GA ČR GD206/09/H026; GA ČR(CZ) GAP302/11/1901 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40550506 Keywords : defensin * antimicrobial compounds * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.937, year: 2011

  2. The Ixodes (Acari: Ixodidae) of Mexico: Parasite-Host and Host-Parasite Checklists

    Science.gov (United States)

    2007-08-20

    en Peligro de Extinción. Comisión Nacional para el Cono- cimiento y Uso de la Biodiversidad, Fondo de Cultura Económica, Instituto de Ecología, UNAM...the largest genus of ticks in the world, currently comprising 243 species (Guglielmone et al. 2006), more than one quarter of the global tick fauna ...include it in the Mexican tick fauna . Ixodes bequaerti Cooley and Kohls Previous record CHIAPAS: 1&, Catharinus (sic), 4-V-1942, NA [Cooley & Kohls, 1945

  3. IrFC - An Ixodes ricinus injury-responsive molecule related to Limulus Factor C

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Veronika; Hartmann, David; Grunclová, Lenka; Šíma, Radek; Flemming, Tina; Hajdušek, Ondřej; Kopáček, Petr

    2014-01-01

    Roč. 46, č. 2 (2014), s. 439-447 ISSN 0145-305X R&D Projects: GA ČR GAP506/10/2136; GA ČR GP13-27630P; GA ČR GP13-12816P; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Complement * Innate immunity * Limulus Clotting Factor C * Phagocytosis * RNA interference * Tick Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 2.815, year: 2014

  4. Presence of potentially pathogenic Babesia sp. for human in Ixodes ricinus in Switzerland.

    Science.gov (United States)

    Casati, Simona; Sager, Heinz; Gern, Lise; Piffaretti, Jean-Claude

    2006-01-01

    We have designed and performed a new PCR method based on the 18S rRNA in order to individuate the presence and the identity of Babesia parasites. Out of 1159 Ixodes ricinus (Acari: Ixodidae) ticks collected in four areas of Switzerland, nine were found to contain Babesia DNA. Sequencing of the short amplicon obtained (411-452 bp) allowed the identification of three human pathogenic species: Babesia microti, B. divergens, for the first time in Switzerland, Babesia sp. EU1. We also report coinfections with B. sp. EU1-Borrelia burgdorferi sensu stricto and Babesia sp. EU1-B. afzelii.

  5. Uptake and incorporation of sialic acid by the tick Ixodes ricinus

    Czech Academy of Sciences Publication Activity Database

    Vancová, Marie; Štěrba, J.; Dupejová, Jarmila; Simonová, Z.; Nebesářová, Jana; Novotný, M. V.; Grubhoffer, Libor

    2012-01-01

    Roč. 58, č. 9 (2012), s. 1277-1287 ISSN 0022-1910 R&D Projects: GA AV ČR KJB600960906; GA ČR GA206/09/1782; GA ČR GD206/09/H026; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Tick * Ixodes ricinus * Sialic acid * Basement membrane * Mass spectrometry * Electron microscopy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.379, year: 2012

  6. Molecular cloning, sequencing and recombinant expression of a ...

    African Journals Online (AJOL)

    The 4D8 gene was recently discovered in Ixodes scapularis and identified as a tick protective antigen. Vaccination using recombinant 4D8 from I. scapularis showed a significant reduction against I. scapularis tick infestation in a sheep model. This protein is expressed in both salivary gland and gut tissues, and is thought to ...

  7. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic. Part I. Ixodes ricinus ticks and tick-borne encephalitis virus

    Czech Academy of Sciences Publication Activity Database

    Daniel, M.; Danielová, V.; Kříž, B.; Růžek, Daniel; Fialová, A.; Malý, M.; Materna, J.; Pejčoch, M.; Erhart, Jan

    2016-01-01

    Roč. 65, č. 2 (2016), s. 118-128 ISSN 1210-7913 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * tick-borne encephalitis virus * occurence * altitude * region * season Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.500, year: 2016

  8. Genetic diversity of Ixodes ricinus (Ixodida: Ixodidae) ticks in sympatric and allopatric zones in Baltic countries.

    Science.gov (United States)

    Paulauskas, A; Galdikaitė-Brazienė, E; Radzijevskaja, J; Aleksandravičienė, A; Galdikas, M

    2016-12-01

    Ixodes ricinus (Linnaeus 1758) and Ixodes persulcatus (Schulze 1930) ticks are involved in the transmission of a wide variety of pathogens with considerable impact on human and animal health. The co-distribution zone of these two tick species is situated in the Baltic countries, which provides a special setting for the population studies. In the present study, genetic variability of I. ricinus ticks collected in allopatric and sympatric locations in the Baltic countries has been investigated using a sequence analysis of the mitochondrial DNA control region, 16S rRNA and cytb genes. There were 32 haplotypes (Hd: 0.8551) and 27 haplotypes (Hd:0.8213) of control region sequences from ticks in allopatric and sympatric zones detected, respectively. Out of 47 16S rRNA gene haplotypes, 32 haplotypes (Hd: 0.7213) were found in the allopatric zone and 27 (Hd:0.9572) in the sympatric zone. The Cytb gene was very conserved and monomorphic in ticks from the allopatric zone, whereas three unique haplotypes were observed in the sympatric zone. The higher number of unique haplotypes of the control region was detected in the allopatric zone. Median joining network and Fst analysis did not reveal a clear separation between ticks from the two zones. © 2016 The Society for Vector Ecology.

  9. Arsenophonus nasoniae and Rickettsiae Infection of Ixodes ricinus Due to Parasitic Wasp Ixodiphagus hookeri.

    Directory of Open Access Journals (Sweden)

    Monika Bohacsova

    Full Text Available Arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. Following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified A. nasoniae in wasps emerging from parasitised nymphs. We confirmed that 28.1% of Ixodiphagus hookeri wasps parasitizing Ixodes ricinus ticks were infected by A. nasoniae. Moreover, in examined I. ricinus nymphs, A. nasoniae was detected only in those, which were parasitized by the wasp. However, in part of the adult wasps as well as in some ticks that contained wasp's DNA, we did not confirm A. nasoniae. We also found, that in spite of reported male-killing, some newly emerged adult wasp males were also infected by A. nasoniae. Additionally, we amplified the DNA of Rickettsia helvetica and Rickettsia monacensis (known to be Ixodes ricinus-associated bacteria in adult parasitoid wasps. This may be related either with the digested bacterial DNA in wasp body lumen or with a role of wasps in circulation of rickettsiae among tick vectors.

  10. Detection and identification of Rickettsia species in Ixodes tick populations from Estonia.

    Science.gov (United States)

    Katargina, Olga; Geller, Julia; Ivanova, Anna; Värv, Kairi; Tefanova, Valentina; Vene, Sirkka; Lundkvist, Åke; Golovljova, Irina

    2015-09-01

    A total of 1640 ticks collected in different geographical parts of Estonia were screened for the presence of Rickettsia species DNA by real-time PCR. DNA of Rickettsia was detected in 83 out of 1640 questing ticks with an overall prevalence of 5.1%. The majority of the ticks infected by rickettsiae were Ixodes ricinus (74 of 83), while 9 of the 83 positive ticks were Ixodes persulcatus. For rickettsial species identification, a part of the citrate synthase gltA gene was sequenced. The majority of the positive samples were identified as Rickettsia helvetica (81 out of 83) and two of the samples were identified as Rickettsia monacensis and Candidatus R. tarasevichiae, respectively. Genetic characterization based on the partial gltA gene showed that the Estonian sequences within the R. helvetica, R. monacensis and Candidatus R. tarasevichiae species demonstrated 100% similarity with sequences deposited in GenBank, originating from Rickettsia species distributed over large territories from Europe to Asia. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. Detection and characterization of Babesia species in Ixodes ticks in Estonia.

    Science.gov (United States)

    Katargina, Olga; Geller, Julia; Vasilenko, Veera; Kuznetsova, Tatiana; Järvekülg, Lilian; Vene, Sirkka; Lundkvist, Åke; Golovljova, Irina

    2011-07-01

    The presence of Babesia spp. was studied in 2603 Ixodes ricinus and Ixodes persulcatus ticks collected at seven sites in Estonia. By reverse line blot screening, Babesia spp. was detected in 36 (1.4%) ticks, among them 18 (0.7%) were further recognized by a Babesia microti probe, 3 (0.1%) by a Babesia divergens probe, and the other 15 (0.6%) were recognized only by the universal Babesia spp. "catch all" probe. Sequence analyses of 6 of these 15 samples revealed that all of them belonged to Babesia sp. EU1. B. microti was detected in both tick species I. ricinus and I. persulcatus at the seven sites, whereas B. divergens-like and Babesia sp. EU1 were found only in I. persulcatus and I. ricinus, respectively. Genetic characterization based on partial 18S rRNA showed that the Estonian sequences of B. microti, B. divergens-like, and Babesia sp. EU1 share a high rate of similarity and are closely related to sequences from other European countries, Siberia, and United States. The present study demonstrated for the first time the existence and distribution of Babesia spp. in I. persulcatus and I. ricinus ticks in Estonia.

  12. Variability and action mechanism of a family of anticomplement proteins in Ixodes ricinus.

    Directory of Open Access Journals (Sweden)

    Bernard Couvreur

    Full Text Available BACKGROUND: Ticks are blood feeding arachnids that characteristically take a long blood meal. They must therefore counteract host defence mechanisms such as hemostasis, inflammation and the immune response. This is achieved by expressing batteries of salivary proteins coded by multigene families. METHODOLOGY/PRINCIPAL FINDINGS: We report the in-depth analysis of a tick multigene family and describe five new anticomplement proteins in Ixodes ricinus. Compared to previously described Ixodes anticomplement proteins, these segregated into a new phylogenetic group or subfamily. These proteins have a novel action mechanism as they specifically bind to properdin, leading to the inhibition of C3 convertase and the alternative complement pathway. An excess of non-synonymous over synonymous changes indicated that coding sequences had undergone diversifying selection. Diversification was not associated with structural, biochemical or functional diversity, adaptation to host species or stage specificity but rather to differences in antigenicity. CONCLUSIONS/SIGNIFICANCE: Anticomplement proteins from I. ricinus are the first inhibitors that specifically target a positive regulator of complement, properdin. They may provide new tools for the investigation of role of properdin in physiological and pathophysiological mechanisms. They may also be useful in disorders affecting the alternative complement pathway. Looking for and detecting the different selection pressures involved will help in understanding the evolution of multigene families and hematophagy in arthropods.

  13. ´Candidatus Midichloria mitochondrii´, an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle

    Czech Academy of Sciences Publication Activity Database

    Sassera, D.; Beninati, T.; Bandi, C.; Bouman, Edwin Arien Poul; Sacchi, L.; Fabbi, M.; Lo, N.

    2006-01-01

    Roč. 56, č. 11 (2006), s. 2535-2540 ISSN 1466-5026 R&D Projects: GA ČR GA206/04/0751 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * endosymbiont * intramitochondrial Subject RIV: EH - Ecology, Behaviour Impact factor: 2.662, year: 2006

  14. Isolation, cultivation and identification of Borrelia burgdorferi genospecies from Ixodes ricinus ticks from the city of Brno, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Pejchalová, K.; Žákovská, A.; Mejzlíková, M.; Halouzka, Jiří; Dendis, M.

    2007-01-01

    Roč. 14, č. 1 (2007), s. 75-79 ISSN 1232-1966 Institutional research plan: CEZ:AV0Z60930519 Keywords : Borrelia burgdorferi * cultivation * DFM method * Ixodes ricinus * Lyme Subject RIV: EE - Microbiology, Virology Impact factor: 1.074, year: 2007 http://www.aaem.pl/pdf/1475.pdf

  15. Arthropod repellency, especially tick (Ixodes ricinus), exerted by extract from Artemisia abrotanum and essential oil from flowers of Dianthus caryophyllum.

    Science.gov (United States)

    Tunón, H; Thorsell, W; Mikiver, A; Malander, I

    2006-06-01

    A toluene extract of southernwood (Artemisia abrotanum) and the essential oil from flowers of carnation (Dianthus caryophyllum ) exerted pronounced a repellent effect both against ticks (nymphs of Ixodes ricinus) and yellow fever mosquitoes (Aedes aegypti). The most potent repellents found were coumarin and thujyl alcohol from A. abrotanum and phenylethanol from D. caryophyllum where coumarin and thujyl alcohol were also detected.

  16. 'Candidatus Rickettsia mendelii', a novel basal group rickettsia detected in Ixodes ricinus ticks in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hajdušková, Eva; Literák, I.; Papoušek, I.; Costa, F.B.; Nováková, M.; Labruna, M. B.; Zdražilová-Dubská, L.

    2016-01-01

    Roč. 7, č. 3 (2016), s. 482-486 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : Rickettsiae * Candidatus Rickettsia mendelii * Ixodes ricinus * basal group rickettsiae * ticks * Czech Republic Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.230, year: 2016

  17. Identification of Borrelia burgdorferi genospecies isolated from Ixodes ricinus ticks in the South Moravian region of the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Bonczek, Ondřej; Žákovská, A.; Vargová, L.; Šerý, Omar

    2015-01-01

    Roč. 22, č. 4 (2015), s. 642-646 ISSN 1232-1966 Institutional support: RVO:67985904 Keywords : Borrelia burgdorferi s. I. * Borrelia spielmanii * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.895, year: 2015

  18. First evidence of Babesia venatorum and Babesia capreoli in questing Ixodes ricinus ticks in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Venclíková, Kristýna; Mendel, Jan; Betášová, Lenka; Hubálek, Zdeněk; Rudolf, Ivo

    2015-01-01

    Roč. 22, č. 2 (2015), s. 212-214 ISSN 1232-1966 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Babesia sp. EU1 * Babesia venatorum * Babesia capreoli * Ixodes ricinus * ixodid ticks Subject RIV: EE - Microbiology, Virology Impact factor: 0.895, year: 2015

  19. Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests

    NARCIS (Netherlands)

    Hofmeester, Tim R.; Sprong, Hein; Jansen, Patrick A.; Prins, Herbert H.T.; Wieren, Van Sipke E.

    2017-01-01

    Background: Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density

  20. Transmission differentials for multible pathogens as inferred from their prevalence in larva, nymph and sult of Ixodes ricinus (Acari: Ixodidae)

    DEFF Research Database (Denmark)

    Jensen, Per M.; Christoffersen, Christian S.; Moutailler, Sara

    2017-01-01

    Ixodes ricinus serves as vector for a range of microorganisms capable of causing clinical illness in humans. The microorganisms occur in the same vector populations and are generally affected by the same tick-host interactions. Still, the instars have different host preferences which should...

  1. Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests.

    NARCIS (Netherlands)

    Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E

    2017-01-01

    Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as

  2. O virus do mixoma no coelho do mato (Sylvilagus minenses, sua transmissão pelos Aedes scapularis e aegypti

    Directory of Open Access Journals (Sweden)

    Henrique Beaurepaire Aragão

    1943-01-01

    Full Text Available The brazilian wild rabbit (Sylvilagus minensis is sensible to the virus of the mixomatosis but the desease takes on it a mild character, lasts for long time and generally do not kill the animal. The tumors are generally smaller and less numerous than those of the domestic rabbit, but sometimes there were noted large and flat lesions (fig. 3. The natural infection of the wild rabbit may be quite common not only because many rabbits caught in the country were found to be immune as also because it was found among the animals caught in the country near Rio, one that was infected with mixomatosis. The experimental infection of the Sylvilagus may be easily obtained by cutan, subcutan or conjuntival way and also when a health wild rabbit is placed in the same cage with a sick domestic animal. It is also possible to obtain the infection of the wild and domestic rabbits by the bite of infected blood sucking insects as fleas and mosquitoes. The infected mosquito can transmit the disease 2 or 3 times til 17 days after an infective meal on a sick rabbit. The transmission is a mecanical one and only the proboscis of the insect contains the virus as it was shown by the inoculation of emulsions of the proboscis, thorax and abdomen of the mosquito. Though mecanical this kind of transmission acts as an important epidemiological mean of dissemination of the deseasse and splains the suddendly outbreaks of mixomatosis in rabbits breedings where no new rabbits were introduced since very long time. The transmition of mixomatosis by fleas (Slenopsylla was at first demonstrated by us, then S. Torres pointed out the capacity of Culex fatigans to transmit the desease and now we have proved that Aedes scapularis and Aedes aegypti were also able to transmit it (Foto 1 and 2. The virus of the mixomatosis (Chlamidozoon mixoma is seen on the smeavs of the tumors of the wild reabbit with the same morphology, as in the material of the domestic animal.

  3. Ixodes ricinus tick lipocalins: identification, cloning, phylogenetic analysis and biochemical characterization.

    Directory of Open Access Journals (Sweden)

    Jérôme Beaufays

    Full Text Available BACKGROUND: During their blood meal, ticks secrete a wide variety of proteins that interfere with their host's defense mechanisms. Among these proteins, lipocalins play a major role in the modulation of the inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: Screening a cDNA library in association with RT-PCR and RACE methodologies allowed us to identify 14 new lipocalin genes in the salivary glands of the Ixodes ricinus hard tick. A computational in-depth structural analysis confirmed that LIRs belong to the lipocalin family. These proteins were called LIR for "Lipocalin from I. ricinus" and numbered from 1 to 14 (LIR1 to LIR14. According to their percentage identity/similarity, LIR proteins may be assigned to 6 distinct phylogenetic groups. The mature proteins have calculated pM and pI varying from 21.8 kDa to 37.2 kDa and from 4.45 to 9.57 respectively. In a western blot analysis, all recombinant LIRs appeared as a series of thin bands at 50-70 kDa, suggesting extensive glycosylation, which was experimentally confirmed by treatment with N-glycosidase F. In addition, the in vivo expression analysis of LIRs in I. ricinus, examined by RT-PCR, showed homogeneous expression profiles for certain phylogenetic groups and relatively heterogeneous profiles for other groups. Finally, we demonstrated that LIR6 codes for a protein that specifically binds leukotriene B4. CONCLUSIONS/SIGNIFICANCE: This work confirms that, regarding their biochemical properties, expression profile, and sequence signature, lipocalins in Ixodes hard tick genus, and more specifically in the Ixodes ricinus species, are segregated into distinct phylogenetic groups suggesting potential distinct function. This was particularly demonstrated by the ability of LIR6 to scavenge leukotriene B4. The other LIRs did not bind any of the ligands tested, such as 5-hydroxytryptamine, ADP, norepinephrine, platelet activating factor, prostaglandins D2 and E2, and finally leukotrienes B4 and C

  4. Characterization of the early local immune response to Ixodes ricinus tick bites in human skin.

    Science.gov (United States)

    Glatz, Martin; Means, Terry; Haas, Josef; Steere, Allen C; Müllegger, Robert R

    2017-03-01

    Little is known about the immunomodulation by tick saliva during a natural tick bite in human skin, the site of the tick-host interaction. We examined the expression of chemokines, cytokines and leucocyte markers on the mRNA levels and histopathologic changes in human skin biopsies of tick bites (n=37) compared to unaffected skin (n=9). Early tick-bite skin lesions (skin. With longer tick attachment (>24 hours), the numbers of innate immune cells and mediators (not significantly) declined, whereas the numbers of lymphocytes (not significantly) increased. Natural tick bites by Ixodes ricinus ticks initially elicit a strong local innate immune response in human skin. Beyond 24 hours of tick attachment, this response usually becomes less, perhaps because of immunomodulation by tick saliva. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. [Search for protective antigens in Ixodes persulcatus (ixodidae) salivary gland extracts].

    Science.gov (United States)

    Shtannikov, A V; Reshetniak, T V; Repolovskaia, T V; Panfertsev, E A; Perovskaia, O N; Gutova, V P; Vasil'eva, I S; Ershova, A S; Prilipov, A G; Biketov, S F; Zeidner, N

    2010-01-01

    RT-PCR evaluation of the activity of eight Ixodes persulcatus salivary gland genes shows clear distinctions in their expression depending of the stage of tick feeding. Out of them, only Salp 10 and Salp 15 proteins may be regarded as candidates for protective antigens to develop anti-tick and anti-Borrelia vaccines. Firstly they play an important role in feeding a tick and modifying a host's immune response. Secondly, the increasing expression of the salp 10 and salp 10 genes begins at early tick feeding stages. Thirdly, the activity of these genes increases with the beginning of feeding by tens and hundreds times and keeps at this level until the third tick feeding stage is over.

  6. Experimental in vitro transmission of Babesia sp. (EU1) by Ixodes ricinus.

    Science.gov (United States)

    Bonnet, Sarah; Brisseau, Nadine; Hermouet, Axelle; Jouglin, Maggy; Chauvin, Alain

    2009-01-01

    Babesia sp. (EU1), first characterized in 2003, has been implicated in human cases of babesiosis in Italy, Austria and Germany. It has been identified in roe deer and in its suspected tick vector, Ixodes ricinus, in several European countries. The aim of the present study was to validate the competence of I. ricinus as a vector of Babesia sp. (EU1) via experimental infections. For this purpose, a parasite strain isolated from roe deer was cloned in sheep erythrocytes. After experimental infections, parasite DNA was successfully amplified by PCR in both eggs and larvae originating from infected I. ricinus females and in the salivary glands of females exposed to Babesia sp. (EU1) as nymphs. We also demonstrate that infected females were able to transmit parasite DNA during a new blood meal. Together with previous epidemiological studies, these results validate I. ricinus as a competent vector for Babesia sp. (EU1).

  7. Infestation of mammals by Ixodes ricinus ticks (Acari: Ixodidae) in south-central Sweden.

    Science.gov (United States)

    Tälleklint, L; Jaenson, T G

    1997-12-01

    Infestation by Ixodes ricinus ticks on rodents, hares and cervids was examined at Bogesund, 10 km north of Stockholm, in south-central Sweden during 1991-1994 and on varying hares (Lepus timidus) at Stora Karlsö and Gotska Sandön in the Baltic Sea during 1992-1993. At Bogesund, there were great differences between two consecutive years in the number of I. ricinus larvae infesting bank voles (Clethrionomys glareolus). The seasonal pattern of infestation by I. ricinus larvae and nymphs on bank voles was unimodal in 1991, with peaks in June-July and bimodal in 1992, with peaks in June and August. Male bank voles, compared to females and older voles, compared to young voles, harboured greater numbers of I. ricinus ticks. Apodemus mice, compared to bank voles, harboured greater numbers of I. ricinus ticks. Ixodes ricinus larvae engorged on Apodemus mice were heavier than larvae engorged on bank voles and resulted in larger nymphs. However, there was no difference in the proportions of viable nymphs resulting from larvae engorged on mice or voles. The ranges in the numbers of I. ricinus ticks infesting individual hosts were 1-451 for rodents, 16-2374 for hares and 428-2072 for roe deer (Capreolus capreolus). These ranges of tick numbers are estimated to represent potential blood losses from individual hosts of approximately 0.2-65% for rodents, 0.2-13% for hares and 0.3-9.0% for roe deer. Within the populations of all host species examined, the distributions of all stages of I. ricinus were clumped, with most host individuals harbouring few ticks and only a few individuals harbouring many ticks. The data suggest that, even though a small proportion of tick hosts may be severely affected, the direct effects of feeding by I. ricinus are unlikely to play an important role on mammal population dynamics.

  8. Detection of Anaplasma phagocytophilum DNA in Ixodes Ticks (Acari: Ixodidae) from Madeira Island and Setúbal District, Mainland Portugal

    Science.gov (United States)

    Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

    2004-01-01

    A total of 278 Ixodes ticks, collected from Madeira Island and Setúbal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setúbal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setúbal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus. PMID:15498168

  9. Detection of Anaplasma phagocytophilum DNA in Ixodes ticks (Acari: Ixodidae) from Madeira Island and Setubal District, mainland Portugal.

    Science.gov (United States)

    Santos, Ana Sofia; Santos-Silva, Maria Margarida; Almeida, Victor Carlos; Bacellar, Fátima; Dumler, John Stephen

    2004-09-01

    A total of 278 Ixodes ticks, collected from Madeira Island and Setubal District, mainland Portugal, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Six (4%) of 142 Ixodes ricinus nymphs collected in Madeira Island and 1 nymph and 1 male (2%) of 93 I. ventalloi collected in Setubal District tested positive for A. phagocytophilum msp2 genes or rrs. Infection was not detected among 43 I. ricinus on mainland Portugal. All PCR products were confirmed by nucleotide sequencing to be identical or to be most closely related to A. phagocytophilum. To our knowledge, this is the first evidence of A. phagocytophilum in ticks from Setubal District, mainland Portugal, and the first documentation of Anaplasma infection in I. ventalloi. Moreover, these findings confirm the persistence of A. phagocytophilum in Madeira Island's I. ricinus.

  10. Two ways of experimental infection of Ixodes ricinus ticks (Acari: Ixodidae) with spirochetes of Borrelia burgdorferi sensu lato complex

    Czech Academy of Sciences Publication Activity Database

    Fišerová, Lenka; Černá, Kateřina; Horká, Helena; Kopecký, Jan

    2008-01-01

    Roč. 55, č. 2 (2008), s. 150-154 ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Lyme disease spirochete * Borrelia burgdorferi * Borrelia baronii * Borrelia afzelii * tick * Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 1.307, year: 2008

  11. Effect of salivary gland extract from Ixodes ricinus ticks on the proliferation of Borrelia burgdorferi sensu stricto in vivo

    Czech Academy of Sciences Publication Activity Database

    Macháčková, Martina; Oborník, Miroslav; Kopecký, Jan

    2006-01-01

    Roč. 53, č. 2 (2006), s. 153-158 ISSN 0015-5683 R&D Projects: GA ČR GA524/05/0811 Grant - others:Studentská grantová agentura, Biologická fakulta Jihočeské univerzity(CZ) SGA2004/009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi * Ixodes ricinus * saliva-activated transmission Subject RIV: EC - Immunology Impact factor: 1.511, year: 2006

  12. Effect of forest clearing on the abundance of Ixodes ricinus ticks and the prevalence of Borrelia burgdorferi s.l

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina; Šikutová, Silvie; Rudolf, Ivo

    2006-01-01

    Roč. 20, č. 2 (2006), s. 166-172 ISSN 0269-283X R&D Projects: GA ČR GA206/03/0726 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : Ixodes ricinus * Borrelia burgdorferi sensu lato * Lyme borreliosis risk Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 2.033, year: 2006

  13. Salivary gland extract from engorged Ixodes ricinus (Acari: Ixodidae) stimulates in vitro growth of Borrelia burgdorferi sensu lato

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Šikutová, Silvie; Kopecký, Jan; Hubálek, Zdeněk

    2010-01-01

    Roč. 50, č. 3 (2010), s. 294-298 ISSN 0233-111X R&D Projects: GA ČR GA206/03/0726; GA AV ČR IAA600960811 Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z60220518 Keywords : salivary gland extract * Ixodes ricinus ticks * Borrelia burgdorferi sensu lato Subject RIV: EE - Microbiology, Virology Impact factor: 1.395, year: 2010

  14. Europe-Wide Meta-Analysis of Borrelia burgdorferi Sensu Lato Prevalence in Questing Ixodes ricinus Ticks

    Czech Academy of Sciences Publication Activity Database

    Strnad, Martin; Hönig, Václav; Růžek, Daniel; Grubhoffer, Libor; Rego, Ryan O. M.

    2017-01-01

    Roč. 83, č. 15 (2017), č. článku e00609-17. ISSN 0099-2240 EU Projects: European Commission(XE) 278976 - ANTIGONE; European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Borrelia burgdorferi sensu lato * tick * Ixodes ricinus * genospecies * meta-analysis * Lyme borreliosis * Lyme disease Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.807, year: 2016

  15. Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments

    OpenAIRE

    Ehrmann, Steffen; Ruyts, Sanne C.; Scherer-Lorenzen, Michael; Bauhus, Jürgen; Brunet, Jörg; Cousins, Sara A. O.; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Gärtner, Stefanie; Hansen, Karin; Kolb, Annette

    2018-01-01

    Background The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes ...

  16. Broad-range survey of vector-borne pathogens and tick host identification of Ixodes ricinus from Southern Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hönig, Václav; Carolan, H. E.; Vavrušková, Zuzana; Massire, C.; Mosel, M.l R.; Crowder, C. D.; Rounds, M. A.; Ecker, D. J.; Růžek, Daniel; Grubhoffer, Libor; Luft, B. J.; Eshoo, M. W.

    2017-01-01

    Roč. 93, č. 11 (2017), č. článku fix129. ISSN 0168-6496 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : burgdorferi sensu-lato * tick * Ixodes ricinus * pcr-esi/ms * Borrelia * host * Lyme borreliosis * Babesia * Anaplasma * Rickettsia Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.720, year: 2016

  17. Functional expression and characterization of cathepsin B and L from the gut of the tick Ixodes ricinus

    Czech Academy of Sciences Publication Activity Database

    Franta, Zdeněk; Pěničková, Helena; Dvorak, J.; Schneider, E. I.; Horn, Martin; Mareš, Michael; Sojka, Daniel; McKerrow, J. H.; Caffrey, C. R.; Kopáček, Petr

    2009-01-01

    Roč. 276, S1 (2009), s. 309-309 ISSN 1742-464X. [34th FEBS Congress: Life's Molecular Interactions. 04.07.2009-09.07.2009, Prague] R&D Projects: GA AV ČR IAA600960910; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40550506 Keywords : cathepsin B and L * Ixodes ricinus * functionl expresssion Subject RIV: EB - Genetics ; Molecular Biology

  18. Revisiting the TALE repeat.

    Science.gov (United States)

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  19. Reconfigurable multiport EPON repeater

    Science.gov (United States)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  20. Quantum repeated games revisited

    International Nuclear Information System (INIS)

    Frąckiewicz, Piotr

    2012-01-01

    We present a scheme for playing quantum repeated 2 × 2 games based on Marinatto and Weber’s approach to quantum games. As a potential application, we study the twice repeated Prisoner’s Dilemma game. We show that results not available in the classical game can be obtained when the game is played in the quantum way. Before we present our idea, we comment on the previous scheme of playing quantum repeated games proposed by Iqbal and Toor. We point out the drawbacks that make their results unacceptable. (paper)

  1. Preferências alimentares e domiciliação de mosquitos Culicidae no Vale do Ribeira, São Paulo, Brasil, com especial referência a Aedes scapularis e a Culex (Melanoconion Feeding preferences and domiciliation of Culicidae mosquitoes in the Ribeira Valley, S. Paulo State, Brazil, with particular reference to Aedes scapularis and Culex (Melanoconion

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1989-02-01

    Full Text Available Apresentam-se novos dados sobre a identificação do sangue ingerido por culicídeos ingurgitados e coletados em quatro localidades do Vale do Ribeira, Estado de São Paulo (Brasil, no período de fevereiro a novembro de 1986, e que já tinham sido sede de observações anteriores. São fornecidos dados sobre a distribuição de algumas espécies relacionadas ao tipo de ambiente. Focalizam-se Ae. scapularis e representantes de Culex (Melanoconion, principalmente Cx. ribeirensis e Cx. sacchettae. Foi possível a identificação de 651 repastos sangüíneos. Confirmou-se a preferência de Ae. scapularis por mamíferos de grande porte representados por bovinos, eqüinos e o próprio homem, tendo reagido a todos os anti-soros testados, com exceção do correspondente a animais de sangue frio representados por anfíbio. Cx. ribeirensis revelou resultados que sugerem possível preferência por mamíferos. As duas espécies supracitadas mostram tendência nítida para adaptação ao ambiente modificado pelo homem e capacidade de evolução de seus hábitos de possível domiciliação. Quanto aos outros culicídeos, as coletas de An. bellator, An. cruzii e Cq. chrysonotum limitaram-se à isca humana que a segunda dessas espécies rendeu 31,6% do total de fêmeas capturadas.New results on blood-meal identification and the environmental distribution of mosquitoes collected in four different Ribeira Valley (S. Paulo State, Brazil environments, during the period February to November 1986, are presented. Sources of 651 blood-meals were identified. The preference of Ae. scapularis for large mammals, chiefly cattle, horse and even man, was confirmed. Data suggests that a similar behavioral pattern is presented by Cx. ribeirensis. Both mosquitoes seem to be strongly attracted by peridomiciliar blood sources represented by domestic animals sheltered in that environment. Nevertheless, the female of Ae. scapularis females may use the extradomiciliary environment

  2. Repeat migration and disappointment.

    Science.gov (United States)

    Grant, E K; Vanderkamp, J

    1986-01-01

    This article investigates the determinants of repeat migration among the 44 regions of Canada, using information from a large micro-database which spans the period 1968 to 1971. The explanation of repeat migration probabilities is a difficult task, and this attempt is only partly successful. May of the explanatory variables are not significant, and the overall explanatory power of the equations is not high. In the area of personal characteristics, the variables related to age, sex, and marital status are generally significant and with expected signs. The distance variable has a strongly positive effect on onward move probabilities. Variables related to prior migration experience have an important impact that differs between return and onward probabilities. In particular, the occurrence of prior moves has a striking effect on the probability of onward migration. The variable representing disappointment, or relative success of the initial move, plays a significant role in explaining repeat migration probabilities. The disappointment variable represents the ratio of actural versus expected wage income in the year after the initial move, and its effect on both repeat migration probabilities is always negative and almost always highly significant. The repeat probabilities diminish after a year's stay in the destination region, but disappointment in the most recent year still has a bearing on the delayed repeat probabilities. While the quantitative impact of the disappointment variable is not large, it is difficult to draw comparisons since similar estimates are not available elsewhere.

  3. Rickettsia vini n. sp. (Rickettsiaceae) infecting the tick Ixodes arboricola (Acari: Ixodidae).

    Science.gov (United States)

    Novakova, Marketa; Costa, Francisco B; Krause, Frantisek; Literak, Ivan; Labruna, Marcelo B

    2016-08-26

    Recently, a new rickettsia named 'Candidatus Rickettsia vini' belonging to the spotted fever group has been molecularly detected in Ixodes arboricola ticks in Spain, the Czech Republic, Slovakia and Turkey, with prevalence reaching up to 100 %. The aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new Rickettsia species. A total of 148 ornitophilic nidicolous ticks Ixodes arboricola were collected in a forest near Breclav (Czech Republic) and examined for rickettsiae. Shell vial technique was applied to isolate rickettsiae in Vero cells. Rickettsial isolation was confirmed by optical microscopy and sequencing of partial sequences of the rickettsial genes gltA, ompA, ompB, and htrA. Laboratory guinea pigs and chickens were used for experimental infestations and infections. Animal blood sera were tested by immunofluorescence assay employing crude antigens of various rickettsiae. Rickettsia vini n. sp. was successfully isolated from three males of I. arboricola. Phylogenetic analysis of fragments of 1092, 590, 800, and 497 nucleotides of the gltA, ompA, ompB, and htrA genes, respectively, showed closest proximity of R. vini n. sp. to Rickettsia japonica and Rickettsia heilongjiangensis belonging to the spotted fever group. Experimental infection of guinea pigs and chickens with R. vini led to various levels of cross-reactions of R. vini-homologous antibodies with Rickettsia rickettsii, Rickettsia parkeri, 'Candidatus Rickettsia amblyommii', Rickettsia rhipicephali, Rickettsia bellii, and Rickettsia felis. Laboratory infestations by R. vini-infected I. arboricola larvae on chickens led to no seroconversion to R. vini n. sp., nor cross-reactions with R. rickettsii, R. parkeri, 'Ca. R. amblyommii', R. rhipicephali, R. bellii or R. felis. Our results suggest that R. vini n. sp. is possibly a tick endosymbiont, not pathogenic for guinea pigs and chickens. Regarding specific phenotypic characters and significant differences of DNA

  4. Crystallization and diffraction analysis of the serpin IRS-2 from the hard tick Ixodes ricinus

    International Nuclear Information System (INIS)

    Kovářová, Zuzana; Chmelař, Jindřich; Šanda, Miloslav; Brynda, Jiří; Mareš, Michael; Řezáčová, Pavlína

    2010-01-01

    Cleavage of the serpin IRS-2 from the hard tick I. ricinus by contaminating proteolytic activity mimicked the specific processing of the serpin by its target protease and resulted in a more stable form of the serpin which produced crystals that diffracted to 1.8 Å resolution. IRS-2 from the hard tick Ixodes ricinus belongs to the serpin family of protease inhibitors. It is produced in the salivary glands of the tick and its anti-inflammatory activity suggests that it plays a role in parasite–host interaction. Recombinant IRS-2 prepared by heterologous expression in a bacterial system was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to the primitive tetragonal space group P4 3 and diffracted to 1.8 Å resolution. Mass-spectrometric and electrophoretic analyses revealed that IRS-2 was cleaved by contaminating proteases during crystallization. This processing of IRS-2 mimicked the specific cleavage of the serpin by its target protease and resulted in a more stable form (the so-called relaxed conformation), which produced well diffracting crystals. Activity profiling with specific substrates and inhibitors demonstrated traces of serine and cysteine proteases in the protein stock solution

  5. Exon variability of gene encoding glycerol-3-phosphate dehydrogenase of Ixodes ricinus ticks*

    Directory of Open Access Journals (Sweden)

    Radulović Ž.

    2010-12-01

    Full Text Available We have previously found apparent differences in Gpdh allele frequences between borrelia infected and uninfected Ixodes ricinus as revealed by native gel electrophoresis of allozyme polymorphisms. The present study deals with the genetic basis of the observed allozyme polymorphism. Multiple sequence alignment of 36 Gpdh open reading frames identified a total of 40 polymorphic nucleotide sites. Of the 40 polymorphic nucleotide sites, 34 were silent (did not result in amino acid residue change, while six were active causing a change in the amino acid chain. All polymorphic amino acid sites were situated within the N-terminal NAD-binding domain, whereas the C-terminal substrate-binding domain was highly conserved. Analysis of the obtained Gpdh sequences and GPDH allozyme polymorphisms for individual ticks pointed to amino acid changes at positions 61 (glycine-to-glutamic acid, 64 (serineto- cysteine and 102 (glycine-to-arginine as a key for differential mobility of GPDH allozymes in an electric field. Our findings are discussed in the context of the molecular basis of I. ricinus host finding behavior.

  6. Prevalence of pathogenic bacteria in Ixodes ricinus ticks in Central Bohemia.

    Science.gov (United States)

    Klubal, Radek; Kopecky, Jan; Nesvorna, Marta; Sparagano, Olivier A E; Thomayerova, Jana; Hubert, Jan

    2016-01-01

    Bacteria associated with the tick Ixodes ricinus were assessed in specimens unattached or attached to the skin of cats, dogs and humans, collected in the Czech Republic. The bacteria were detected by PCR in 97 of 142 pooled samples including 204 ticks, i.e. 1-7 ticks per sample, collected at the same time from one host. A fragment of the bacterial 16S rRNA gene was amplified, cloned and sequenced from 32 randomly selected samples. The most frequent sequences were those related to Candidatus Midichloria midichlori (71% of cloned sequences), followed by Diplorickettsia (13%), Spiroplasma (3%), Rickettsia (3%), Pasteurella (3%), Morganella (3%), Pseudomonas (2%), Bacillus (1%), Methylobacterium (1%) and Phyllobacterium (1%). The phylogenetic analysis of Spiroplasma 16S rRNA gene sequences showed two groups related to Spiroplasma eriocheiris and Spiroplasma melliferum, respectively. Using group-specific primers, the following potentially pathogenic bacteria were detected: Borellia (in 20% of the 142 samples), Rickettsia (12%), Spiroplasma (5%), Diplorickettsia (5%) and Anaplasma (2%). In total, 68% of I. ricinus samples (97/142) contained detectable bacteria and 13% contained two or more putative pathogenic groups. The prevalence of tick-borne bacteria was similar to the observations in other European countries.

  7. Nonspecific Bacterial Flora Isolated from the Body Surface and Inside Ixodes ricinus Ticks.

    Science.gov (United States)

    Okła, Hubert; Sosnowska, Malwina; Jasik, Krzysztof P; Słodki, Jan; Wojtyczka, Robert D

    2012-09-28

    Ixodes ricinus and other representatives of the order Ixodida are vectors of typical pathogens: Borrelia burgdorferi sensu lato, Anaplasma phagocytophilium, Babesia spp., a tick-borne encephalitis virus, and other microorganisms which are important from a medical and veterinary point of view. The presented study focuses on the verification of nonspecific bacterial flora of I. ricinus. We analyzed ticks collected in a forest region in Silesia, an industrial district in Poland. Methods of classical microbiology and biochemical assays (API 20 NE test, API Staph test and MICRONAUT System) were used for isolation and identification of microorganisms living on the body surface of I. ricinus and inside ticks. The results show the presence of various bacteria on the surface and inside ticks' bodies. During the study, we isolated Acinetobacter lwoffi, Pseudomonas fluorescens, Aeromonas hydrophila, Achromobacter denitrificans, Alcaligenes faecalis, Stenotrophomonas maltophilia, Pseudomonas oryzihabitans, Micrococcus spp., Kocuria varians, Staphylococcus lentus, Kocuria kristinae, Streptococcus pneumoniae, Rhizobium radiobacter, Staphylococcus xylosus. Majority of the isolated species are non-pathogenic environmental microorganisms, but some of the isolated bacterial strains could cause severe infections.

  8. The prevalence of Anaplasma phagocytophilum in questing Ixodes ricinus ticks in SW Poland.

    Science.gov (United States)

    Kiewra, Dorota; Zaleśny, Grzegorz; Czułowska, Aleksandra

    2014-01-01

    Ticks constitute important vectors of human and animal pathogens. Besides the Lyme borreliosis and tick-borne encephalitis, other pathogens such as Babesia spp., Rickettsia spp., and Anaplasma phagocytophilum, are of increasing public health interest. In Poland, as in other European countries, Ixodes ricinus, the most prevalent tick species responsible for the majority of tick bites in humans, is the main vector of A. phagocytophilum. The aim of the study was to estimate the infection level of I. ricinus with A. phagocytophilum in selected districts, not previously surveyed for the presence of this agent. Sampling of questing ticks was performed in 12 forested sites, located in four districts (Legnica, Milicz, Lubań, and Oława) in SW Poland. Altogether, 792 ticks (151 females, 101 males, and 540 nymphs) representing I. ricinus were checked for the presence of A. phagocytophilum. The average infection level was 4.3%, with higher rate reported for adult ticks. The highest percentage of infected adults was observed in Milicz (17.4%) and the lowest in Oława (6.8%). The abundance of questing I. ricinus in all examined sites as well as the infection with A. phagocytophilum indicate for the first time the risk for HGA transmission in SW Poland.

  9. Multi-criteria Decision Analysis to Model Ixodes ricinus Habitat Suitability.

    Science.gov (United States)

    Rousseau, Raphaël; McGrath, Guy; McMahon, Barry J; Vanwambeke, Sophie O

    2017-09-01

    Tick-borne diseases present a major threat to both human and livestock health throughout Europe. The risk of infection is directly related to the presence of its vector. Thereby it is important to know their distribution, which is strongly associated with environmental factors: the presence and availability of a suitable habitat, of a suitable climate and of hosts. The present study models the habitat suitability for Ixodes ricinus in Ireland, where data on tick distribution are scarce. Tick habitat suitability was estimated at a coarse scale (10 km) with a multi-criteria decision analysis (MCDA) method according to four different scenarios (depending on the variables used and on the weights granted to each of them). The western part of Ireland and the Wicklow mountains in the East were estimated to be the most suitable areas for I. ricinus in the island. There was a good level of agreement between results from the MCDA and recorded tick presence. The different scenarios did not affect the spatial outputs substantially. The current study suggests that tick habitat suitability can be mapped accurately at a coarse scale in a data-scarce context using knowledge-based methods. It can serve as a guideline for future countrywide sampling that would help to determine local risk of tick presence and refining knowledge on tick habitat suitability in Ireland.

  10. A Novel Rickettsia Species Detected in Vole Ticks (Ixodes angustus) from Western Canada

    Science.gov (United States)

    Anstead, Clare A.

    2013-01-01

    The genomic DNA of ixodid ticks from western Canada was tested by PCR for the presence of Rickettsia. No rickettsiae were detected in Ixodes sculptus, whereas 18% of the I. angustus and 42% of the Dermacentor andersoni organisms examined were PCR positive for Rickettsia. The rickettsiae from each tick species were characterized genetically using multiple genes. Rickettsiae within the D. andersoni organisms had sequences at four genes that matched those of R. peacockii. In contrast, the Rickettsia present within the larvae, nymphs, and adults of I. angustus had novel DNA sequences at four of the genes characterized compared to the sequences available from GenBank for all recognized species of Rickettsia and all other putative species within the genus. Phylogenetic analyses of the sequence data revealed that the rickettsiae in I. angustus do not belong to the spotted fever, transitional, or typhus groups of rickettsiae but are most closely related to “Candidatus Rickettsia kingi” and belong to a clade that also includes R. canadensis, “Candidatus Rickettsia tarasevichiae,” and “Candidatus Rickettsia monteiroi.” PMID:24077705

  11. Low prevalence of Borrelia bavariensis in Ixodes ricinus ticks in southeastern Austria.

    Science.gov (United States)

    Glatz, Martin; Muellegger, Robert R; Hizo-Teufel, Cecilia; Fingerle, Volker

    2014-10-01

    Borrelia bavariensis was recently described as a distinct genospecies among the B. burgdorferi sensu lato complex. The prevalence of B. bavariensis in Austria, a highly endemic area for tick-transmitted pathogens, is scarcely characterized. To investigate the prevalence of B. bavariensis in Ixodes ricinus ticks we reevaluated the results of a study conducted in 518 ticks from southeastern Austria collected in 2002 and 2003. The presence of B. burgdorferi s.l.-specific DNA in ticks was analyzed by a PCR for the outer surface protein A (ospA) gene. Borrelia species were differentiated by restriction fragment length polymorphism (RFLP) analysis, and samples positive for B. bavariensis were further analyzed by multilocus sequence analysis. Two of 133 (1.5%) B. burgdorferi s.l.-positive I. ricinus ticks were infected with B. bavariensis. Both specimens were coinfected with the OspA serotype 5 of B. garinii. Borrelia bavariensis is present; however, seem to be rare in I. ricinus ticks in southeastern Austria. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. From Chemistry to Behavior. Molecular Structure and Bioactivity of Repellents against Ixodes ricinus Ticks.

    Directory of Open Access Journals (Sweden)

    Simone Del Fabbro

    Full Text Available Tick-borne zoonoses are considered as emerging diseases. Tick repellents represent an effective tool for reducing the risk of tick bite and pathogens transmission. Previous work demonstrated the repellent activity of the phenylpropanoid eugenol against Ixodes ricinus; here we investigate the relationship between molecular structure and repellency in a group of substances related to that compound. We report the biological activity of 18 compounds varying for the presence/number of several moieties, including hydroxyl and methoxy groups and carbon side-chain. Each compound was tested at different doses with a bioassay designed to measure repellency against individual tick nymphs. Both vapor pressure and chemical features of the tested compounds appeared to be related to repellency. In particular, the hydroxyl and methoxy groups as well as the side-chain on the benzene ring seem to play a role. These results are discussed in light of available data on chemical perception in ticks. In the course of the study new repellent compounds were identified; the biological activity of some of them (at least as effective as the "gold standard" repellent DEET appears to be very promising from a practical point of view.

  13. How ticks get under your skin: insertion mechanics of the feeding apparatus of Ixodes ricinus ticks

    Science.gov (United States)

    Richter, Dania; Matuschka, Franz-Rainer; Spielman, Andrew; Mahadevan, L.

    2013-01-01

    The tick Ixodes ricinus uses its mouthparts to penetrate the skin of its host and to remain attached for about a week, during which time Lyme disease spirochaetes may pass from the tick to the host. To understand how the tick achieves both tasks, penetration and attachment, with the same set of implements, we recorded the insertion events by cinematography, interpreted the mouthparts’ function by scanning electron microscopy and identified their points of articulation by confocal microscopy. Our structural dynamic observations suggest that the process of insertion and attachment occurs via a ratchet-like mechanism with two distinct stages. Initially, the two telescoping chelicerae pierce the skin and, by moving alternately, generate a toehold. Subsequently, a breaststroke-like motion, effected by simultaneous flexure and retraction of both chelicerae, pulls in the barbed hypostome. This combination of a flexible, dynamic mechanical ratchet and a static holdfast thus allows the tick to solve the problem of how to penetrate skin and also remain stuck for long periods of time. PMID:24174106

  14. Essential oils of aromatic Egyptian plants repel nymphs of the tick Ixodes ricinus (Acari: Ixodidae).

    Science.gov (United States)

    El-Seedi, Hesham R; Azeem, Muhammad; Khalil, Nasr S; Sakr, Hanem H; Khalifa, Shaden A M; Awang, Khalijah; Saeed, Aamer; Farag, Mohamed A; AlAjmi, Mohamed F; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2017-09-01

    Due to the role of Ixodes ricinus (L.) (Acari: Ixodidae) in the transmission of many serious pathogens, personal protection against bites of this tick is essential. In the present study the essential oils from 11 aromatic Egyptian plants were isolated and their repellent activity against I. ricinus nymphs was evaluated Three oils (i.e. Conyza dioscoridis L., Artemisia herba-alba Asso and Calendula officinalis L.) elicited high repellent activity in vitro of 94, 84.2 and 82%, respectively. The most active essential oil (C. dioscoridis) was applied in the field at a concentration of 6.5 µg/cm 2 and elicited a significant repellent activity against I. ricinus nymphs by 61.1%. The most repellent plants C. dioscoridis, C. officinalis and A. herba-alba yielded essential oils by 0.17, 0.11 and 0.14%, respectively. These oils were further investigated using gas chromatography-mass spectrometry analysis. α-Cadinol (10.7%) and hexadecanoic acid (10.5%) were the major components of C. dioscoridis whereas in C. officinalis, α-cadinol (21.2%) and carvone (18.2%) were major components. Artemisia herba-alba contained piperitone (26.5%), ethyl cinnamate (9.5%), camphor (7.7%) and hexadecanoic acid (6.9%). Essential oils of these three plants have a potential to be used for personal protection against tick bites.

  15. Vector competence of the tick Ixodes ricinus for transmission of Bartonella birtlesii.

    Directory of Open Access Journals (Sweden)

    Caroline Reis

    Full Text Available Bartonella spp. are facultative intracellular vector-borne bacteria associated with several emerging diseases in humans and animals all over the world. The potential for involvement of ticks in transmission of Bartonella spp. has been heartily debated for many years. However, most of the data supporting bartonellae transmission by ticks come from molecular and serological epidemiological surveys in humans and animals providing only indirect evidences without a direct proof of tick vector competence for transmission of bartonellae. We used a murine model to assess the vector competence of Ixodes ricinus for Bartonella birtlesii. Larval and nymphal I. ricinus were fed on a B. birtlesii-infected mouse. The nymphs successfully transmitted B. birtlesii to naïve mice as bacteria were recovered from both the mouse blood and liver at seven and 16 days after tick bites. The female adults successfully emitted the bacteria into uninfected blood after three or more days of tick attachment, when fed via membrane feeding system. Histochemical staining showed the presence of bacteria in salivary glands and muscle tissues of partially engorged adult ticks, which had molted from the infected nymphs. These results confirm the vector competence of I. ricinus for B. birtlesii and represent the first in vivo demonstration of a Bartonella sp. transmission by ticks. Consequently, bartonelloses should be now included in the differential diagnosis for patients exposed to tick bites.

  16. Aggregation in the tick Ixodes ricinus (Acari: Ixodidae): use and reuse of questing vantage points.

    Science.gov (United States)

    Healy, John A E; Bourke, Patrick

    2008-03-01

    Ongoing work in oak woods in Killarney National Park in southwestern Ireland is focusing on the factors influencing the fine-scale aggregated distribution of Ixodes ricinus L. (Acari: Ixodidae) on the ground. The extent of reuse of stems of vegetation as questing points by adult ticks was determined by paint-marking stems on which ticks were found, counting and removing these ticks, and subsequently reexamining the same stems for ticks on two further occasions. Overall, an estimated 2,967 stems in 123 separate rush plants (Juncus effusus L.) were examined. Statistical analysis of the data demonstrated a highly significant reoccupancy by ticks of stems previously and recently used. Furthermore, it is shown that the extent of stem reuse by ticks is significantly and positively correlated with the numbers of ticks originally observed on those stems. Although other factors may be involved in generating clumping of ticks, the results are compatible with the proposition that aggregation of I. ricinus on the ground is pheromone-mediated. The findings are discussed in relation to what is known about the powers of lateral movement of I. ricinus on the ground and the possible implications for the performance of tick traps.

  17. The Pentapeptide Repeat Proteins

    OpenAIRE

    Vetting, Matthew W.; Hegde, Subray S.; Fajardo, J. Eduardo; Fiser, Andras; Roderick, Steven L.; Takiff, Howard E.; Blanchard, John S.

    2006-01-01

    The Pentapeptide Repeat Protein (PRP) family has over 500 members in the prokaryotic and eukaryotic kingdoms. These proteins are composed of, or contain domains composed of, tandemly repeated amino acid sequences with a consensus sequence of [S,T,A,V][D,N][L,F]-[S,T,R][G]. The biochemical function of the vast majority of PRP family members is unknown. The three-dimensional structure of the first member of the PRP family was determined for the fluoroquinolone resistance protein (MfpA) from Myc...

  18. Repeated Causal Decision Making

    Science.gov (United States)

    Hagmayer, York; Meder, Bjorn

    2013-01-01

    Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

  19. simple sequence repeat (SSR)

    African Journals Online (AJOL)

    In the present study, 78 mapped simple sequence repeat (SSR) markers representing 11 linkage groups of adzuki bean were evaluated for transferability to mungbean and related Vigna spp. 41 markers amplified characteristic bands in at least one Vigna species. The transferability percentage across the genotypes ranged ...

  20. The Genus Ixodes (Acari: Ixodidae) in Mexico: Adult Identification Keys, Diagnoses, Hosts, and Distribution (El genero Ixodes (Acari: Ixodidae) en Mexico: claves de identificacion para adultos, diagnosis, huespedes y distribucion)

    Science.gov (United States)

    2010-01-01

    also from Estado de México (Hoffmann, 1969). Hosts in Mexico. Cricetidae and Hominidae ( Homo sapiens Linnaeus, 1758) (Mammalia) (Hoffmann, 1969...distribution El género Ixodes (Acari: Ixodidae) en México: claves de identifi cación para adultos, diagnosis, huéspedes y distribución Carmen Guzmán...postdoctoral scholarship under the Programa de Formación e Incorporación de Profesores de Carrera en Facultades y Escuelas para el Fortalecimiento de la

  1. Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes ricinus ticks from different sites of North-Eastern Poland.

    Science.gov (United States)

    Dunaj, Justyna; Zajkowska, Joanna Maria; Kondrusik, Maciej; Gern, Lise; Rais, Oliver; Moniuszko, Anna; Pancewicz, Sławomir; Świerzbińska, Renata

    2014-01-01

    RLB (Reverse Line Blot Hybridization) is a molecular biology technique that might be used for Borrelia burgdorferi sensu lato (sl) DNA detection with genospecies specification. Among B. burgdorferi sl genospecies at least 7 are regarded as pathogenic in Europe. The aim of the study was to evaluate the frequency of different Borrelia genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. Ixodes ricinus ticks were collected in May - June, from 6 different sites in North-Eastern Poland (Jakubin, Kolno, Grajewo, Suwałki, Siemiatycze, Białowieża) by flagging. Extracted DNA was amplified by polymerase chain reaction (PCR) targeting the intergenic spacer 5S 23S of B. burgdorferi sl. PCR products were hybridised to 15 different oligonucleotide probes for 9 different Borrelia genospecies (B. burgdorferi sl, B. burgdorferi ss, B. garinii, B. afzelii, B. valaisiana, B. lusitaniae, B. spielmanii, B. bissettii and B. relapsing fever-like spirochetes (B. myamotoi)) by RLB. Borrelia genospecies DNA was detected in 205 Ixodes ricinus ticks. Among 14 infected with Borrelia ticks, 4 were identified as B. garinii and 10 as B. afzelii. Higher numbers of infected ticks were noticed in the eastern part of the research area, where large forest complexes dominate. Nymphs appeared to be the most frequently infected tick stage, which has an epidemiological meaning in the incidence of Lyme borreliosis. The study demonstrated that RLB might be easily used in Borrelia DNA detection with genospecies-identification, and indicated the domination of B. afzelii and B. garinii in ticks from North-Eastern Poland.

  2. High degree of mitochondrial gene heterogeneity in the bat tick species Ixodes vespertilionis, I. ariadnae and I. simplex from Eurasia.

    Science.gov (United States)

    Hornok, Sándor; Estrada-Peña, Agustín; Kontschán, Jenő; Plantard, Olivier; Kunz, Bernd; Mihalca, Andrei D; Thabah, Adora; Tomanović, Snežana; Burazerović, Jelena; Takács, Nóra; Görföl, Tamás; Estók, Péter; Tu, Vuong Tan; Szőke, Krisztina; Fernández de Mera, Isabel G; de la Fuente, José; Takahashi, Mamoru; Yamauchi, Takeo; Takano, Ai

    2015-09-17

    Phylogeographical studies allow precise genetic comparison of specimens, which were collected over large geographical ranges and belong to the same or closely related animal species. These methods have also been used to compare ticks of veterinary-medical importance. However, relevant data are missing in the case of ixodid ticks of bats, despite (1) the vast geographical range of both Ixodes vespertilionis and Ixodes simplex, and (2) the considerable uncertainty in their taxonomy, which is currently unresolvable by morphological clues. In the present study 21 ticks were selected from collections or were freshly removed from bats or cave walls in six European and four Asian countries. The DNA was extracted and PCRs were performed to amplify part of the cytochrome oxidase I (COI), 16S and 12S rDNA genes, followed by sequencing for identification and molecular-phylogenetic comparison. No morphological differences were observed between Ixodes vespertilionis specimens from Spain and from other parts of Europe, but corresponding genotypes had only 94.6 % COI sequence identity. An I. vespertilionis specimen collected in Vietnam was different both morphologically and genetically (i.e. with only 84.1 % COI sequence identity in comparison with I. vespertilionis from Europe). Two ticks (collected in Vietnam and in Japan) formed a monophyletic clade and shared morphological features with I. ariadnae, recently described and hitherto only reported in Europe. In addition, two Asiatic specimens of I. simplex were shown to differ markedly from European genotypes of the same species. Phylogenetic relationships of ticks showed similar clustering patterns with those of their associated bat host species. Although all three ixodid bat tick species evaluated in the present study appear to be widespread in Eurasia, they exhibit pronounced genetic differences. Data of this study also reflect that I. vespertilionis may represent a species complex.

  3. Tick thioester-containing proteins and phagocytosis do not affect transmission of Borrelia afzelii from the competent vector ixodes ricinus

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Veronika; Hajdušek, Ondřej; Hönig Mondeková, Helena; Šíma, Radek; Kopáček, Petr

    2017-01-01

    Roč. 7, MAR (2017), č. článku 73. ISSN 2235-2988 R&D Projects: GA ČR GJ15-12006Y; GA ČR GA13-11043S; GA ČR GA17-27386S; GA ČR GA17-27393S EU Projects: European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Borrelia * complement * Ixodes * phagocytosis * thioester-containing proteins Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 4.300, year: 2016

  4. The majority of sialylated glycoproteins in adult Ixodes ricinus ticks originate in the host, not the tick

    Czech Academy of Sciences Publication Activity Database

    Štěrba, Ján; Vancová, Marie; Štěrbová, Jarmila; Bell-Sakyi, L.; Grubhoffer, Libor

    2014-01-01

    Roč. 389, MAY 2014 (2014), s. 93-99 ISSN 0008-6215 R&D Projects: GA ČR(CZ) GAP302/11/1901; GA ČR GAP302/12/2490; GA MŠk(CZ) LC06009; GA MŠk(CZ) EE2.3.30.0032; GA ČR GA206/09/1782 Institutional support: RVO:60077344 Keywords : tick * Ixodes ricinus * sialic acid * tick cell line Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.929, year: 2014

  5. First molecular evidence of potentially zoonotic Babesia microti and Babesia sp. EU1 in Ixodes ricinus ticks in Belgium

    OpenAIRE

    Lempereur, L.; De Cat, A.; Caron, Y.; Madder, M.; Claerebout, E.; Saegerman, C.; Losson, B.

    2011-01-01

    We report the first molecular evidence of the presence of Babesia sp. EU1 and Babesia microti in Ixodes ricinus ticks in Belgium. A 1-year national survey collected 1005 ticks from cats and dogs. A polymerase chain reaction technique amplifying a part of the 18S rRNA gene detected Babesia spp. in 11 out of 841 selected and validated tick extracts. Subsequent sequencing identified Ba. microti (n = 3) and Babesia sp. EU1 (n = 6). This study has demonstrated a low infection rate (1.31% with 95% ...

  6. Characterization of Ixodes ricinus fibrinogen-related proteins (Ixoderins) discloses their function in the tick innate immunity

    Czech Academy of Sciences Publication Activity Database

    Hönig Mondeková, Helena; Šíma, Radek; Urbanová, Veronika; Kovář, Vojtěch; Rego, Ryan O. M.; Grubhoffer, Libor; Kopáček, Petr; Hajdušek, Ondřej

    2017-01-01

    Roč. 7, DEC (2017), č. článku 509. ISSN 2235-2988 R&D Projects: GA ČR GA17-27386S; GA ČR GA17-27393S; GA ČR GJ15-12006Y; GA ČR GA13-11043S EU Projects: European Commission(XE) 602272 - ANTIDotE Institutional support: RVO:60077344 Keywords : Fibrinogen-related protein * Ixoderin * Ixodes * Lectin * RNAi * Tick Subject RIV: EC - Immunology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.300, year: 2016

  7. Diversity of viruses in Ixodes ricinus, and characterization of a neurotropic strain of Eyach virus

    Directory of Open Access Journals (Sweden)

    S. Moutailler

    2016-05-01

    Full Text Available Ticks transmit more pathogens—including bacteria, parasites and viruses—than any other arthropod vector. Although the epidemiological status of many tick-borne bacteria is very well characterized, tick-borne viruses are still relatively under-studied. Recently, several novel tick-borne viruses have been isolated from human febrile illnesses following tick bites, indicating the existence of other potential new and unknown tick-borne viruses. We used high-throughput sequencing to analyse the virome of Ixodes ricinus, the main vector of tick-borne pathogens in Europe. The majority of collected viral sequences were assigned to two potentially novel Nairovirus and Phlebovirus viruses, with prevalence rates ranging from 3.95% to 23.88% in adults and estimated to be between 0.14% and 72.16% in nymphs. These viruses could not be isolated from the brains of inoculated immunocompromised mice, perhaps indicating that they are unable to infect vertebrates. Within the I. ricinus virome, we also identified contigs with >90% identity to the known Eyach virus. Initially isolated in the 1980s, this virus was indirectly associated with human disease, but had never been extensively studied. Eyach virus prevalence varied between 0.07% and 5.26% in ticks from the French Ardennes and Alsace regions. Eyach virus was successfully isolated following intracerebral inoculation of immunocompromised mice with Eyach virus-positive tick extracts. This virus was also able to multiply and persist in the blood of immunocompetent mice inoculated by intraperitoneal injection, and caused brain infections in three of nine juveniles, without any obvious deleterious effects.

  8. Infections and Coinfections of Questing Ixodes ricinus Ticks by Emerging Zoonotic Pathogens in Western Switzerland

    Science.gov (United States)

    Lommano, Elena; Bertaiola, Luce; Dupasquier, Christèle

    2012-01-01

    In Europe, Ixodes ricinus is the vector of many pathogens of medical and veterinary relevance, among them Borrelia burgdorferi sensu lato and tick-borne encephalitis virus, which have been the subject of numerous investigations. Less is known about the occurrence of emerging tick-borne pathogens like Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and Anaplasma phagocytophilum in questing ticks. In this study, questing nymph and adult I. ricinus ticks were collected at 11 sites located in Western Switzerland. A total of 1,476 ticks were analyzed individually for the simultaneous presence of B. burgdorferi sensu lato, Rickettsia spp., Babesia spp., “Candidatus Neoehrlichia mikurensis,” and A. phagocytophilum. B. burgdorferi sensu lato, Rickettsia spp., and “Candidatus Neoehrlichia mikurensis” were detected in ticks at all sites with global prevalences of 22.5%, 10.2%, and 6.4%, respectively. Babesia- and A. phagocytophilum-infected ticks showed a more restricted geographic distribution, and their prevalences were lower (1.9% and 1.5%, respectively). Species rarely reported in Switzerland, like Borrelia spielmanii, Borrelia lusitaniae, and Rickettsia monacensis, were identified. Infections with more than one pathogenic species, involving mostly Borrelia spp. and Rickettsia helvetica, were detected in 19.6% of infected ticks. Globally, 34.2% of ticks were infected with at least one pathogen. The diversity of tick-borne pathogens detected in I. ricinus in this study and the frequency of coinfections underline the need to take them seriously into consideration when evaluating the risks of infection following a tick bite. PMID:22522688

  9. Infection of Ixodes ricinus by Borrelia burgdorferi sensu lato in peri-urban forests of France.

    Directory of Open Access Journals (Sweden)

    Axelle Marchant

    Full Text Available Lyme borreliosis is the most common tick-borne disease in the northern hemisphere. In Europe, it is transmitted by Ixodes ticks that carry bacteria belonging to the Borrelia burgdorferi sensu lato complex. The objective of this work was to explore eco-epidemiological factors of Lyme borreliosis in peri-urban forests of France (Sénart, Notre-Dame and Rambouillet. We investigated whether the introduction of Tamias sibiricus in Sénart could alter the density of infected ticks. Moreover, the density and tick infection were investigated according to the tree species found in various patches of Sénart forest. For this purpose, ticks were sampled during 3 years. In the Sénart forest, the density of nymph and adult ticks showed no significant difference between 2008, 2009 and 2011. The nymph density varied significantly as a function of the month of collection. Regarding the nymphs, a higher rate of infection and infected density were found in 2009. Plots with chipmunks (C presented a lower density of both nymphs and adult ticks than plots without chipmunks (NC did. A higher rate of infection of nymphs with Borrelia was seen in C plots. The prevalence of the various species of Borrelia was also found to vary between C and NC plots with the year of the collect. The presence of chestnut trees positively influenced the density of both nymphs and adults. The infected nymph density showed a significant difference depending on the peri-urban forest studied, Sénart being higher than Rambouillet. The prevalence of Borrelia species also differed between the various forests studied. Concerning the putative role that Tamias sibiricus may play in the transmission of Borrelia, our results suggest that its presence is correlated with a higher rate of infection of questing ticks by Borrelia genospecies and if its population increases, it could play a significant role in the risk of transmission of Lyme borreliosis.

  10. Driving forces for changes in geographical distribution of Ixodes ricinus ticks in Europe

    Directory of Open Access Journals (Sweden)

    Medlock Jolyon M

    2013-01-01

    Full Text Available Abstract Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick’s geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.

  11. Diversity of viruses in Ixodes ricinus, and characterization of a neurotropic strain of Eyach virus.

    Science.gov (United States)

    Moutailler, S; Popovici, I; Devillers, E; Vayssier-Taussat, M; Eloit, M

    2016-05-01

    Ticks transmit more pathogens-including bacteria, parasites and viruses-than any other arthropod vector. Although the epidemiological status of many tick-borne bacteria is very well characterized, tick-borne viruses are still relatively under-studied. Recently, several novel tick-borne viruses have been isolated from human febrile illnesses following tick bites, indicating the existence of other potential new and unknown tick-borne viruses. We used high-throughput sequencing to analyse the virome of Ixodes ricinus, the main vector of tick-borne pathogens in Europe. The majority of collected viral sequences were assigned to two potentially novel Nairovirus and Phlebovirus viruses, with prevalence rates ranging from 3.95% to 23.88% in adults and estimated to be between 0.14% and 72.16% in nymphs. These viruses could not be isolated from the brains of inoculated immunocompromised mice, perhaps indicating that they are unable to infect vertebrates. Within the I. ricinus virome, we also identified contigs with >90% identity to the known Eyach virus. Initially isolated in the 1980s, this virus was indirectly associated with human disease, but had never been extensively studied. Eyach virus prevalence varied between 0.07% and 5.26% in ticks from the French Ardennes and Alsace regions. Eyach virus was successfully isolated following intracerebral inoculation of immunocompromised mice with Eyach virus-positive tick extracts. This virus was also able to multiply and persist in the blood of immunocompetent mice inoculated by intraperitoneal injection, and caused brain infections in three of nine juveniles, without any obvious deleterious effects.

  12. Dynamics of digestive proteolytic system during blood feeding of the hard tick Ixodes ricinus

    Directory of Open Access Journals (Sweden)

    Sojka Daniel

    2010-12-01

    Full Text Available Abstract Background Ticks are vectors of a wide variety of pathogens causing severe diseases in humans and domestic animals. Intestinal digestion of the host blood is an essential process of tick physiology and also a limiting factor for pathogen transmission since the tick gut represents the primary site for pathogen infection and proliferation. Using the model tick Ixodes ricinus, the European Lyme disease vector, we have previously demonstrated by genetic and biochemical analyses that host blood is degraded in the tick gut by a network of acidic peptidases of the aspartic and cysteine classes. Results This study reveals the digestive machinery of the I. ricinus during the course of blood-feeding on the host. The dynamic profiling of concentrations, activities and mRNA expressions of the major digestive enzymes demonstrates that the de novo synthesis of peptidases triggers the dramatic increase of the hemoglobinolytic activity along the feeding period. Overall hemoglobinolysis, as well as the activity of digestive peptidases are negligible at the early stage of feeding, but increase dramatically towards the end of the slow feeding period, reaching maxima in fully fed ticks. This finding contradicts the established opinion that blood digestion is reduced at the end of engorgement. Furthermore, we show that the digestive proteolysis is localized intracellularly throughout the whole duration of feeding. Conclusions Results suggest that the egressing proteolytic system in the early stage of feeding and digestion is a potential target for efficient impairment, most likely by blocking its components via antibodies present in the host blood. Therefore, digestive enzymes are promising candidates for development of novel 'anti-tick' vaccines capable of tick control and even transmission of tick-borne pathogens.

  13. Description of a new tick species, Ixodes collaris n. sp. (Acari: Ixodidae), from bats (Chiroptera: Hipposideridae, Rhinolophidae) in Vietnam.

    Science.gov (United States)

    Hornok, Sándor; Görföl, Tamás; Estók, Péter; Tu, Vuong Tan; Kontschán, Jenő

    2016-06-10

    In a recent study on ixodid bat ticks from Eurasia, a high genetic difference was found between Ixodes vespertilionis from Europe and Vietnam. Accordingly, it was proposed that I. vespertilionis is a species complex, with at least one additional, hitherto undescribed species. The aim of the present study was to investigate the morphology of bat ticks from Vietnam and to assess their taxonomic status in comparison with those collected in Europe. Ixodid bat ticks (two females and two nymphs) collected from the pomona leaf-nosed bat (Hipposideros pomona) (Hipposideridae) and intermediate horseshoe bat (Rhinolophus affinis) (Rhinolophidae) in Vietnam showed major morphological differences from European isolates of I. vespertilionis, including the shape of the scutum, the enclosure and shape of porose areas, the presence of a caudo-lateral collar-like ridge ventrally on the basis capituli, polytrich coxae with short setae, and grouped (non-linear) arrangement of anterior pit sensillae in Haller's organ. In this study the female and the nymph of an ixodid bat tick species from Vietnam are described for the first time. The genetic and morphological differences between I. vespertilionis Koch, 1844 and these bat ticks from Vietnam justify the status of the latter as a distinct species, Ixodes collaris Hornok n. sp.

  14. The role of rodents in the ecology of Ixodes ricinus and associated pathogens in Central and Eastern Europe.

    Science.gov (United States)

    Mihalca, Andrei D; Sándor, Attila D

    2013-01-01

    Rodents comprise more species than any other mammal order. Most rodents are considered keystone species in their ecological communities, hence the survival of many other species in the ecosystem depend on them. From medical point of view, this is particularly important for rodent-dependent pathogens. In the particular case of tick-borne diseases, rodents are important as hosts for vector ticks and as reservoir hosts (Lyme borreliosis, human granulocytic anaplasmosis, Crimean-Congo hemorrhagic fever, Tick-borne relapsing fevers, tick-borne rickettsioses, babesiosis). Community and population ecology of rodents was shown to be correlated with disease ecology in the case of many tick-borne diseases. In Eastern Europe, several adult hard-tick species use rodents as their principal hosts: Ixodes apronophorus, I. crenulatus, I. laguri, I. redikorzevi, I. trianguliceps. However, the majority of ticks feeding on rodents are immature stages of ticks which as adults are parasitic on larger mammals. Larvae and nymphs of Ixodes ricinus, the most abundant and medically important tick from Europe, are commonly found on rodents. This is particularly important, as many rodents are synanthropic and, together with other micromammals and birds are often the only available natural hosts for ticks in urban environments. This work reviews the correlated ecology of rodents and I. ricinus.

  15. Prevalence of Borrelia burgdorferi sensu lato genospecies in host-seeking Ixodes ricinus ticks in selected South Bohemian locations (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Danielová, V.; Daniel, M.; Rudenko, Natalia; Golovchenko, Maryna

    2004-01-01

    Roč. 12, č. 3 (2004), s. 151-156 ISSN 1210-7778 R&D Projects: GA ČR GA524/03/1326 Institutional research plan: CEZ:AV0Z6022909 Keywords : Ixodes ricinus * Borrelia * Czech Republic Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine

  16. Ixodes ricinus and its transmitted pathogens in urban and peri-urban areas in Europe: new hazards and relevance for public health

    Czech Academy of Sciences Publication Activity Database

    Rizzoli, A.; Silaghi, C.; Obiegala, A.; Rudolf, Ivo; Hubálek, Zdeněk; Földvári, G.; Plantard, O.; Vayssier-Taussat, M.; Bonnet, S.; Špitalská, E.; Kazimírová, M.

    2014-01-01

    Roč. 2, č. 251 (2014) ISSN 2296-2565 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : ticks * Ixodes ricinus * tick-borne pathogens * urban habitats * Europe Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology

  17. Vertical distribution of the tick Ixodes ricinus and tick-borne pathogens in the Northern Moravian mountaines correlated with climate warming (Jeseníky mts., Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Daniel, M.; Materna, J.; Hönig, Václav; Metelka, L.; Danielová, V.; Harčarik, J.; Kliegrová, S.; Grubhoffer, Libor

    2009-01-01

    Roč. 17, č. 3 (2009), s. 139-145 ISSN 1210-7778 R&D Projects: GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Borrelia burgdorferi genospecies * tick-borne encephalitis virus * vertical distribution * climate warming Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology

  18. The Tick Salivary Protein Sialostatin L2 Inhibits Caspase-1-Mediated Inflammation during Anaplasma phagocytophilum Infection

    Czech Academy of Sciences Publication Activity Database

    Chen, G.; Wang, X.; Sakhon, O. S.; Sohail, M.; Brown, L.J.; Sircar, M.; Snyder, G.A.; Sundberg, E.J.; Ulland, T.K.; Olivier, A.K.; Andersen, J. F.; Zhou, Y.; Shi, G.-P.; Sutterwala, F.S.; Kotsyfakis, Michalis; Pedra, J. H. F.

    2014-01-01

    Roč. 82, č. 6 (2014), s. 2553-2564 ISSN 0019-9567 Institutional support: RVO:60077344 Keywords : granulocytic ehrlichiosis agent * Ixodes scapularis * tumor necrosis factor Subject RIV: EC - Immunology Impact factor: 3.731, year: 2014

  19. Ehrlichiosis

    Science.gov (United States)

    ... Ehrlichia bacteria can be carried by the: American dog tick Deer tick ( Ixodes scapularis ), which can also ... your vital signs, including: Blood pressure Heart rate Temperature Other tests include: Complete blood count ( CBC ) Granulocyte ...

  20. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-12-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  1. Environmental drivers of Ixodes ricinus abundance in forest fragments of rural European landscapes.

    Science.gov (United States)

    Ehrmann, Steffen; Liira, Jaan; Gärtner, Stefanie; Hansen, Karin; Brunet, Jörg; Cousins, Sara A O; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Kolb, Annette; Lenoir, Jonathan; Lindgren, Jessica; Naaf, Tobias; Paal, Taavi; Valdés, Alicia; Verheyen, Kris; Wulf, Monika; Scherer-Lorenzen, Michael

    2017-09-06

    The castor bean tick (Ixodes ricinus) transmits infectious diseases such as Lyme borreliosis, which constitutes an important ecosystem disservice. Despite many local studies, a comprehensive understanding of the key drivers of tick abundance at the continental scale is still lacking. We analyze a large set of environmental factors as potential drivers of I. ricinus abundance. Our multi-scale study was carried out in deciduous forest fragments dispersed within two contrasting rural landscapes of eight regions, along a macroclimatic gradient stretching from southern France to central Sweden and Estonia. We surveyed the abundance of I. ricinus, plant community composition, forest structure and soil properties and compiled data on landscape structure, macroclimate and habitat properties. We used linear mixed models to analyze patterns and derived the relative importance of the significant drivers. Many drivers had, on their own, either a moderate or small explanatory value for the abundance of I. ricinus, but combined they explained a substantial part of variation. This emphasizes the complex ecology of I. ricinus and the relevance of environmental factors for tick abundance. Macroclimate only explained a small fraction of variation, while properties of macro- and microhabitat, which buffer macroclimate, had a considerable impact on tick abundance. The amount of forest and the composition of the surrounding rural landscape were additionally important drivers of tick abundance. Functional (dispersules) and structural (density of tree and shrub layers) properties of the habitat patch played an important role. Various diversity metrics had only a small relative importance. Ontogenetic tick stages showed pronounced differences in their response. The abundance of nymphs and adults is explained by the preceding stage with a positive relationship, indicating a cumulative effect of drivers. Our findings suggest that the ecosystem disservices of tick-borne diseases, via the

  2. Association of Borrelia and Rickettsia spp. and bacterial loads in Ixodes ricinus ticks.

    Science.gov (United States)

    Raulf, Marie-Kristin; Jordan, Daniela; Fingerle, Volker; Strube, Christina

    2018-01-01

    In recent years, awareness of coinfections has increased as synergistic or antagonistic effects on interacting bacteria have been observed. To date, several reports on coinfections of ticks with Rickettsia and Borrelia spp. are available. However, associations are rarely described and studies are based on rather low sample sizes. In the present study, coinfections of Ixodes ricinus with these pathogens were investigated by determining their association in a meta-analysis. A total of 5079 tick samples examined for Rickettsia and Borrelia spp. via probe-based quantitative real-time PCR in previous prevalence studies or as submitted diagnostic material were included. In Borrelia-positive ticks, genospecies were determined by Reverse Line Blot. Determination of bacterial loads resulted in an increase between developmental tick stages with highest mean bacterial loads in female ticks (7.96×10 4 in Borrelia single-infected, 4.87×10 5 in Rickettsia single-infected and 3.22×10 5 in Borrelia-Rickettsia coinfected females). The determined Borrelia-Rickettsia tick coinfection rate was 12.3% (626/5079) with a significant difference to the expected coinfection rate of 9.0% (457/5079). A significant slight association as well as correlation between Borrelia and Rickettsia were determined. In addition, a significant interrelation of the bacterial load in coinfected ticks was shown. At the level of Borrelia genospecies, significant weak associations with Rickettsia spp. were detected for B. afzelii, B. garinii/bavariensis, B. valaisiana and B. lusitaniae. The positive association provides evidence for interactions between Borrelia and Rickettsia spp. in the tick vector, presumably resulting in higher bacterial replication rates in the tick vector and possibly the reservoir host. However, coinfection may impact the vector negatively as indicated by an absent increase in coinfection rates from nymphs to adults. Future studies are needed to investigate the underlying mechanisms of

  3. Repeat Customer Success in Extension

    Science.gov (United States)

    Bess, Melissa M.; Traub, Sarah M.

    2013-01-01

    Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

  4. 78 FR 65594 - Vehicular Repeaters

    Science.gov (United States)

    2013-11-01

    ... coordinators estimate the effect on coordination fees? Does the supposed benefit that mobile repeater stations... allow the licensing and operation of vehicular repeater systems and other mobile repeaters by public... email: [email protected] or phone: 202-418- 0530 or TTY: 202-418-0432. For detailed instructions for...

  5. Repeated causal decision making.

    Science.gov (United States)

    Hagmayer, York; Meder, Björn

    2013-01-01

    Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in such situations and how they use their knowledge to adapt to changes in the decision context. Our studies show that decision makers' behavior is strongly contingent on their causal beliefs and that people exploit their causal knowledge to assess the consequences of changes in the decision problem. A high consistency between hypotheses about causal structure, causally expected values, and actual choices was observed. The experiments show that (a) existing causal hypotheses guide the interpretation of decision feedback, (b) consequences of decisions are used to revise existing causal beliefs, and (c) decision makers use the experienced feedback to induce a causal model of the choice situation even when they have no initial causal hypotheses, which (d) enables them to adapt their choices to changes of the decision problem. (PsycINFO Database Record (c) 2013 APA, all rights reserved).

  6. The Presence of Borrelia miyamotoi, A Relapsing Fever Spirochaete, in Questing Ixodes ricinus in Belgium and in The Netherlands.

    Science.gov (United States)

    Cochez, C; Heyman, P; Heylen, D; Fonville, M; Hengeveld, P; Takken, W; Simons, L; Sprong, H

    2015-08-01

    Borrelia miyamotoi is a tick-borne bacterium that may cause relapsing fever in humans. As this pathogen has been discovered in Europe only recently, only little is known about its local impact on human health and its spatial distribution. In this study, we show the results of PCR screenings for B. miyamotoi in flagged Ixodes ricinus from Belgium and the Netherlands. B. miyamotoi was detected in nine of thirteen, and three of five locations from the Netherlands and Belgium, respectively. These outcomes indicate that B. miyamotoi is more spread than previously thought. The mean infection rate B. miyamotoi was 1.14% for Belgium and 3.84% for the Netherlands. © 2014 Blackwell Verlag GmbH.

  7. First molecular evidence of potentially zoonotic Babesia microti and Babesia sp. EU1 in Ixodes ricinus ticks in Belgium.

    Science.gov (United States)

    Lempereur, Laetitia; De Cat, Ann; Caron, Yannick; Madder, Maxime; Claerebout, Edwin; Saegerman, Claude; Losson, Bertrand

    2011-02-01

    We report the first molecular evidence of the presence of Babesia sp. EU1 and Babesia microti in Ixodes ricinus ticks in Belgium. A 1-year national survey collected 1005 ticks from cats and dogs. A polymerase chain reaction technique amplifying a part of the 18S rRNA gene detected Babesia spp. in 11 out of 841 selected and validated tick extracts. Subsequent sequencing identified Ba. microti (n=3) and Babesia sp. EU1 (n=6). This study has demonstrated a low infection rate (1.31% with 95% CI: 0.65-2.33) of Babesia spp. carriage in I. ricinus ticks in Belgium but, for the first time, reports two potentially zoonotic species belonging to this genus. Coinfection with Ba. microti and Borrelia burgdorferi sensu stricto also was demonstrated. In addition, this study clearly demonstrates that inhibitors of polymerase chain reaction amplification are present in engorged ticks.

  8. Large scale spatial risk and comparative prevalence of Borrelia miyamotoi and Borrelia burgdorferi sensu lato in Ixodes pacificus.

    Directory of Open Access Journals (Sweden)

    Kerry Padgett

    Full Text Available Borrelia miyamotoi is a newly described emerging pathogen transmitted to people by Ixodes species ticks and found in temperate regions of North America, Europe, and Asia. There is limited understanding of large scale entomological risk patterns of B. miyamotoi and of Borreila burgdorferi sensu stricto (ss, the agent of Lyme disease, in western North America. In this study, B. miyamotoi, a relapsing fever spirochete, was detected in adult (n=70 and nymphal (n=36 Ixodes pacificus ticks collected from 24 of 48 California counties that were surveyed over a 13 year period. Statewide prevalence of B. burgdorferi sensu lato (sl, which includes B. burgdorferi ss, and B. miyamotoi were similar in adult I. pacificus (0.6% and 0.8%, respectively. In contrast, the prevalence of B. burgdorferi sl was almost 2.5 times higher than B. miyamotoi in nymphal I. pacificus (3.2% versus 1.4%. These results suggest similar risk of exposure to B. burgdorferi sl and B. miyamotoi from adult I. pacificus tick bites in California, but a higher risk of contracting B. burgdorferi sl than B. miyamotoi from nymphal tick bites. While regional risk of exposure to these two spirochetes varies, the highest risk for both species is found in north and central coastal California and the Sierra Nevada foothill region, and the lowest risk is in southern California; nevertheless, tick-bite avoidance measures should be implemented in all regions of California. This is the first study to comprehensively evaluate entomologic risk for B. miyamotoi and B. burgdorferi for both adult and nymphal I. pacificus, an important human biting tick in western North America.

  9. Europe-Wide Meta-Analysis of Borrelia burgdorferi Sensu Lato Prevalence in Questing Ixodes ricinus Ticks.

    Science.gov (United States)

    Strnad, Martin; Hönig, Václav; Růžek, Daniel; Grubhoffer, Libor; Rego, Ryan O M

    2017-08-01

    Lyme borreliosis is the most common zoonotic disease transmitted by ticks in Europe and North America. Despite having multiple tick vectors, the causative agent, Borrelia burgdorferi sensu lato , is vectored mainly by Ixodes ricinus in Europe. In the present study, we aimed to review and summarize the existing data published from 2010 to 2016 concerning the prevalence of B. burgdorferi sensu lato spirochetes in questing I. ricinus ticks. The primary focus was to evaluate the infection rate of these bacteria in ticks, accounting for tick stage, adult tick gender, region, and detection method, as well as to investigate any changes in prevalence over time. The data obtained were compared to the findings of a previous metastudy. The literature search identified data from 23 countries, with 115,028 ticks, in total, inspected for infection with B. burgdorferi sensu lato We showed that the infection rate was significantly higher in adults than in nymphs and in females than in males. We found significant differences between European regions, with the highest infection rates in Central Europe. The most common genospecies were B. afzelii and B. garinii , despite a negative correlation of their prevalence rates. No statistically significant differences were found among the prevalence rates determined by conventional PCR, nested PCR, and real-time PCR. IMPORTANCE Borrelia burgdorferi sensu lato is a pathogenic bacterium whose clinical manifestations are associated with Lyme borreliosis. This vector-borne disease is a major public health concern in Europe and North America and may lead to severe arthritic, cardiovascular, and neurological complications if left untreated. Although pathogen prevalence is considered an important predictor of infection risk, solitary isolated data have only limited value. Here we provide summarized information about the prevalence of B. burgdorferi sensu lato spirochetes among host-seeking Ixodes ricinus ticks, the principal tick vector of

  10. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  11. The occurrence of Ixodes ricinus ticks and important tick-borne pathogens in areas with high tick-borne encephalitis prevalence in different altitudinal levels of the Czech Republic Part II. Ixodes ricinus ticks and genospecies of Borrelia burgdorferi sensu lato complex

    Czech Academy of Sciences Publication Activity Database

    Daniel, M.; Rudenko, Natalia; Golovchenko, Maryna; Danielová, V.; Fialová, A.; Kříž, B.; Malý, M.

    2016-01-01

    Roč. 65, č. 2 (2016), s. 182-192 ISSN 1210-7913 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * Borrelia afezelii * B. garinii * B. burgdorferi s. s. * B. bavariensis * B. valaisiana * B. spielmanii * B. lusitaniae * B. bissettii * distribution * altitude * season * medical importance Subject RIV: EE - Microbiology, Virology Impact factor: 0.500, year: 2016

  12. Effect of the salivary gland and midgut extracts from Ixodes ricinus and Dermacentor reticulatus (Acari : Ixodidae) on the growth of Borrelia garinii in vitro

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Hubálek, Zdeněk

    2003-01-01

    Roč. 50, č. 2 (2003), s. 159-160 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022001; GA ČR GA206/00/1204; GA ČR GA206/03/0726 Institutional research plan: CEZ:AV0Z6093917 Keywords : Ixodes ricinus * Dermacentor reticulatus Subject RIV: EE - Microbiology, Virology Impact factor: 0.469, year: 2003 http://folia.paru.cas.cz/pdfs/showpdf.php?pdf=20661

  13. Abundance of Ixodes ricinus and prevalence of Borrelia burgdorferi s.l. in the nature reserve Siebengebirge, Germany, in comparison to three former studies from 1978 onwards

    Czech Academy of Sciences Publication Activity Database

    Schwarz, Alexandra; Hönig, Václav; Vavrušková, Zuzana; Grubhoffer, Libor; Balczun, C.; Albring, A.; Schaub, G. A.

    2012-01-01

    Roč. 5, NOV 21 (2012) ISSN 1756-3305 R&D Projects: GA ČR GD206/09/H026; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * Tick density * Borrelia prevalence * Borrelia lusitaniae * Multiple infections * Siebengebirge Subject RIV: EC - Immunology Impact factor: 3.246, year: 2012 http://www.parasitesandvectors.com/content/5/1/268

  14. IrML – a gene encoding a new member of the ML protein family from the hard tick, Ixodes ricinus

    Czech Academy of Sciences Publication Activity Database

    Horáčková, J.; Rudenko, Natalia; Golovchenko, Maryna; Havlíková, S.; Grubhoffer, Libor

    2010-01-01

    Roč. 35, č. 2 (2010), s. 410-418 ISSN 1081-1710 R&D Projects: GA ČR(CZ) GA524/06/1479; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * tick * ML-domain containing protein * in situ hybridization * gene expression * ML (MD-2-related lipid-recognition) domain Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.256, year: 2010

  15. Film repeats in radiology department

    International Nuclear Information System (INIS)

    Suwan, A. Z.; Al-Shakharah, A. I

    1997-01-01

    During a one year period, 4910 radiographs of 55780 films were repeated. The objective of our study was to analyse and to classify the causes in order to minimize the repeats, cut the expenses and to provide optimal radiographs for accurate diagnosis. Analysis of the different factors revealed that, 43.6% of film repeats in our service were due to faults in exposure factors, centering comprises 15.9% of the repeats, while too much collimation was responsible for 7.6% of these repeats. All of which can be decreased by awareness and programmed training of technicians. Film blurring caused by patient motion was also responsible for 4.9% for radiographs reexamination, which can be minimized by detailed explanation to the patient and providing the necessary privacy. Fogging of X-Ray films by improper storage or inadequate handling or processing faults were responsible for 14.5% in repeats in our study. Methods and criteria for proper storage and handling of films were discussed. Recommendation for using modern day-light and laser processor has been high lighted. Artefacts are noticeably high in our cases, due to spinal dresses and frequent usage of precious metals for c osmotic purposes in this part of the world. The repeated films comprise 8.8% of all films We conclude that, the main factor responsible for repeats of up to 81.6% of cases was the technologists, thus emphasizing the importance of adequate training of the technologists. (authors). 15 refs., 9 figs., 1 table

  16. Nifty Nines and Repeating Decimals

    Science.gov (United States)

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  17. Repeated Prescribed Burning in Aspen

    Science.gov (United States)

    Donald A. Perala

    1974-01-01

    Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

  18. Tevatron serial data repeater system

    International Nuclear Information System (INIS)

    Ducar, R.J.

    1981-01-01

    A ten megabit per second serial data repeater system has been developed for the 6.28km Tevatron accelerator. The repeaters are positioned at each of the thirty service buildings and accommodate control and abort system communications as well as distribution of the Tevatron time and energy clocks. The repeaters are transparent to the particular protocol of the transmissions. Serial data are encoded locally as unipolar two volt signals employing the self-clocking Manchester Bi-Phase code. The repeaters modulate the local signals to low-power bursts of 50 MHz rf carrier for the 260m transmission between service buildings. The repeaters also demodulate the transmission and restructure the data for local utilization. The employment of frequency discrimination techniques yields high immunity to the characteristic noise spectrum

  19. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  20. Repeatability of visual acuity measurement.

    Science.gov (United States)

    Raasch, T W; Bailey, I L; Bullimore, M A

    1998-05-01

    This study investigates features of visual acuity chart design and acuity testing scoring methods which affect the validity and repeatability of visual acuity measurements. Visual acuity was measured using the Sloan and British Standard letter series, and Landolt rings. Identifiability of the different letters as a function of size was estimated, and expressed in the form of frequency-of-seeing curves. These functions were then used to simulate acuity measurements with a variety of chart designs and scoring criteria. Systematic relationships exist between chart design parameters and acuity score, and acuity score repeatability. In particular, an important feature of a chart, that largely determines the repeatability of visual acuity measurement, is the amount of size change attributed to each letter. The methods used to score visual acuity performance also affect repeatability. It is possible to evaluate acuity score validity and repeatability using the statistical principles discussed here.

  1. Description of the immature stages and redescription of the female of Ixodes schulzei Aragão & Fonseca, 1951 (Acari: Ixodidae), an endemic tick species of Brazil.

    Science.gov (United States)

    Barros-Battesti, Darci M; Onofrio, Valeria C; Faccini, João L H; Labruna, Marcelo B; Arruda-Santos, Ana D; Giacomin, Flávia G

    2007-11-01

    Ixodes schulzei Aragão & Fonseca, 1951 is a tick endemic to Brazil, where nine species of Ixodes Latreille, 1796 are currently known to occur. Larvae, nymphs and females of I. schulzei were obtained from a laboratory colony originating from an engorged female collected on a free-living water rat Nectomys squamipes from the Santa Branca municipality, São Paulo State. Only female ticks were obtained from engorged nymphs. Unfed immature and female adult specimens were measured and the descriptions were based on optical and scanning electron microscopy, as were drawings of some features of the larva. Both immature stages present the very long palpi and basis capituli, and the female has large, contiguous porose areas. However, the basis capituli is triangular, with a slight central elevation in the larva and nymph, whereas in the female this area is depressed. The I. schulzei types deposited at the FIOCRUZ (Instituto Oswaldo Cruz) were also examined, as was other material from collections, such as the IBSP (Coleção Acarológica do Instituto Butantan), CNC-FMVZ/USP (Coleção Nacional de Carrapatos da Faculdade de Medicina Veterinária e Zootecnia da USP) and USNTC (United States National Tick Collection). In addition, the relationship between I. schulzei and other immature neotropical species of Ixodes is discussed.

  2. Genomic Resources Notes accepted 1 April 2014 – 31 May 2014

    Czech Academy of Sciences Publication Activity Database

    Contreras, M.; de la Fuente, J.; Estrada-Pena, A.; Grubhoffer, Libor; Tobes, R.

    2014-01-01

    Roč. 14, č. 5 (2014), s. 1095-1095 ISSN 1755-098X Institutional support: RVO:60077344 Keywords : global transcriptome comparison * Ixodes scapularis * Ixodes ricinus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.712, year: 2014

  3. A case of Guillain — Barre syndrome associated with ixodes tick borreliosis and listeriosis

    Directory of Open Access Journals (Sweden)

    O.N. Domashenko

    2017-03-01

    , colorless, contains protein 0.71g/l, cytosis makes 1 cell per mcl (lymphocyte, red cell count was 1–3 per mcl, positive Pandy’s test, and glucose ratio of 3.9 mmol/l. IIFT (IgM, liquor as of 07.11.2016 indentified: negative Rubella virus; measles, mumps, Varicella zoster virus, adenovirus type 3; EBV, capsid antigen; Treponema pallidum; Toxoplasma gondii; HSV type I; negative HSV type II; Coxsackie virus type B1; Coxsackie virus type А7; Echo virus type 7; positive Borrelia afzelii; Borrelia burgdorferi sensu stricto; Borrelia garinii; Listeria monocytogenes 1/2а; Listeria monocytogenes 4b; СМV; negative Hemophilus influenza. PCR (liquor as of 07.11.2016 showed: no Toxoplasma gondii, Human herpes virus type 6, СМV. IgM antibodies profile to Borrelia antigens in the immunoblotting reaction (blood as of 09.11.2016 revealed specific antibodies of IgM class to Borrelia garinii (Flagellin, OspC; OspC to Borrelia afzelii — negative; OspC to Borrelia burgdorferi — negative. There was diagnosed Guillain — Barre acute inflammatory-allergic polyneuropathy (Landry type with pronounced quadriparesis, bulbar syndrome, oculomotor dysfunctions, associated with ixodes tick borreliosis and listeriosis, which were confirmed by IgM revealed to Borrelia garinii (IIFT in the liquor and Western blot reaction in the blood, IgM to Listeria monocytogenes 1/2а, 4b (IIFT in the liquor. The therapy included immunovenin, 5 sessions of plasmapheresis, cefepime, retarpen, cytoflavinum, cycloferonum, ceraxon, actovegin, neuromidin, proserinum, combilipen, diclophenacum, nucleo CMP, mexidol, fluconazole, probiotics, glucose solution, panangin, insulin, L-lysine aescinat, berlithion, suprastin, lasix, berlipril, bisoprololum, tube feeding, APV, microclysters. Since the 48th day of the disease the state of the patient started improving and the rapid recovery of neurological status was observed. Independent breathing restored. The laryngeal-pharyngeal reflexes, sensitive and motor activity

  4. On the complexity of measuring forests microclimate and interpreting its relevance in habitat ecology: the example of Ixodes ricinus ticks

    Directory of Open Access Journals (Sweden)

    Denise Boehnke

    2017-11-01

    Full Text Available Abstract Background Ecological field research on the influence of meteorological parameters on a forest inhabiting species is confronted with the complex relations between measured data and the real conditions the species is exposed to. This study highlights this complexity for the example of Ixodes ricinus. This species lives mainly in forest habitats near the ground, but field research on impacts of meteorological conditions on population dynamics is often based on data from nearby official weather stations or occasional in situ measurements. In addition, studies use very different data approaches to analyze comparable research questions. This study is an extensive examination of the methodology used to analyze the impact of meteorological parameters on Ixodes ricinus and proposes a methodological approach that tackles the underlying complexity. Methods Our specifically developed measurement concept was implemented at 25 forest study sites across Baden-Württemberg, Germany. Meteorological weather stations recorded data in situ and continuously between summer 2012 and autumn 2015, including relative humidity measures in the litter layer and different heights above it (50 cm, 2 m. Hourly averages of relative humidity were calculated and compared with data from the nearest official weather station. Results Data measured directly in the forest can differ dramatically from conditions recorded at official weather stations. In general, data indicate a remarkable relative humidity decrease from inside to outside the forest and from ground to atmosphere. Relative humidity measured in the litter layer were, on average, 24% higher than the official data and were much more balanced, especially in summer. Conclusions The results illustrate the need for, and benefit of, continuous in situ measurements to grasp the complex relative humidity conditions in forests. Data from official weather stations do not accurately represent actual humidity conditions in

  5. On the complexity of measuring forests microclimate and interpreting its relevance in habitat ecology: the example of Ixodes ricinus ticks.

    Science.gov (United States)

    Boehnke, Denise; Gebhardt, Reiner; Petney, Trevor; Norra, Stefan

    2017-11-06

    Ecological field research on the influence of meteorological parameters on a forest inhabiting species is confronted with the complex relations between measured data and the real conditions the species is exposed to. This study highlights this complexity for the example of Ixodes ricinus. This species lives mainly in forest habitats near the ground, but field research on impacts of meteorological conditions on population dynamics is often based on data from nearby official weather stations or occasional in situ measurements. In addition, studies use very different data approaches to analyze comparable research questions. This study is an extensive examination of the methodology used to analyze the impact of meteorological parameters on Ixodes ricinus and proposes a methodological approach that tackles the underlying complexity. Our specifically developed measurement concept was implemented at 25 forest study sites across Baden-Württemberg, Germany. Meteorological weather stations recorded data in situ and continuously between summer 2012 and autumn 2015, including relative humidity measures in the litter layer and different heights above it (50 cm, 2 m). Hourly averages of relative humidity were calculated and compared with data from the nearest official weather station. Data measured directly in the forest can differ dramatically from conditions recorded at official weather stations. In general, data indicate a remarkable relative humidity decrease from inside to outside the forest and from ground to atmosphere. Relative humidity measured in the litter layer were, on average, 24% higher than the official data and were much more balanced, especially in summer. The results illustrate the need for, and benefit of, continuous in situ measurements to grasp the complex relative humidity conditions in forests. Data from official weather stations do not accurately represent actual humidity conditions in forest stands and the explanatory power of short period and

  6. Analysis of repeated measures data

    CERN Document Server

    Islam, M Ataharul

    2017-01-01

    This book presents a broad range of statistical techniques to address emerging needs in the field of repeated measures. It also provides a comprehensive overview of extensions of generalized linear models for the bivariate exponential family of distributions, which represent a new development in analysing repeated measures data. The demand for statistical models for correlated outcomes has grown rapidly recently, mainly due to presence of two types of underlying associations: associations between outcomes, and associations between explanatory variables and outcomes. The book systematically addresses key problems arising in the modelling of repeated measures data, bearing in mind those factors that play a major role in estimating the underlying relationships between covariates and outcome variables for correlated outcome data. In addition, it presents new approaches to addressing current challenges in the field of repeated measures and models based on conditional and joint probabilities. Markov models of first...

  7. Repeated DNA sequences in fungi

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, S K

    1974-11-01

    Several fungal species, representatives of all broad groups like basidiomycetes, ascomycetes and phycomycetes, were examined for the nature of repeated DNA sequences by DNA:DNA reassociation studies using hydroxyapatite chromatography. All of the fungal species tested contained 10 to 20 percent repeated DNA sequences. There are approximately 100 to 110 copies of repeated DNA sequences of approximately 4 x 10/sup 7/ daltons piece size of each. Repeated DNA sequence homoduplexes showed on average 5/sup 0/C difference of T/sub e/50 (temperature at which 50 percent duplexes dissociate) values from the corresponding homoduplexes of unfractionated whole DNA. It is suggested that a part of repetitive sequences in fungi constitutes mitochondrial DNA and a part of it constitutes nuclear DNA. (auth)

  8. Fostering repeat donations in Ghana.

    Science.gov (United States)

    Owusu-Ofori, S; Asenso-Mensah, K; Boateng, P; Sarkodie, F; Allain, J-P

    2010-01-01

    Most African countries are challenged in recruiting and retaining voluntary blood donors by cost and other complexities and in establishing and implementing national blood policies. The availability of replacement donors who are a cheaper source of blood has not enhanced repeat voluntary donor initiatives. An overview of activities for recruiting and retaining voluntary blood donors was carried out. Donor records from mobile sessions were reviewed from 2002 to 2008. A total of 71,701 blood donations; 45,515 (63.5%) being voluntary donations with 11,680 (25%) repeat donations were collected during the study period. Donations from schools and colleges contributed a steady 60% of total voluntary whilst radio station blood drives increased contribution from 10 to 27%. Though Muslim population is less than 20%, blood collection was above the 30-donation cost-effectiveness threshold with a repeat donation trend reaching 60%. In contrast Christian worshippers provided donations. Repeat donation trends amongst school donors and radio blood drives were 20% and 70% respectively. Repeat donations rates have been variable amongst different blood donor groups in Kumasi, Ghana. The impact of community leaders in propagating altruism cannot be overemphasized. Programs aiming at motivating replacement donors to be repeat donors should be developed and assessed. Copyright 2009 The International Association for Biologicals. All rights reserved.

  9. Crowdsourcing-based nationwide tick collection reveals the distribution of Ixodes ricinus and I. persulcatus and associated pathogens in Finland.

    Science.gov (United States)

    Laaksonen, Maija; Sajanti, Eeva; Sormunen, Jani J; Penttinen, Ritva; Hänninen, Jari; Ruohomäki, Kai; Sääksjärvi, Ilari; Vesterinen, Eero J; Vuorinen, Ilppo; Hytönen, Jukka; Klemola, Tero

    2017-05-10

    A national crowdsourcing-based tick collection campaign was organized in 2015 with the objective of producing novel data on tick distribution and tick-borne pathogens in Finland. Nearly 20 000 Ixodes ticks were collected. The collected material revealed the nationwide distribution of I. persulcatus for the first time and a shift northwards in the distribution of I. ricinus in Finland. A subset of 2038 tick samples containing both species was screened for Borrelia burgdorferi sensu lato (the prevalence was 14.2% for I. ricinus and 19.8% for I. persulcatus), B. miyamotoi (0.2% and 0.4%, respectively) and tick-borne encephalitis virus (TBEV; 0.2% and 3.0%, respectively). We also report new risk areas for TBEV in Finland and, for the first time, the presence of B. miyamotoi in ticks from mainland Finland. Most importantly, our study demonstrates the overwhelming power of citizen science in accomplishing a collection effort that would have been impossible with the scientific community alone.

  10. Chemical composition and repellency of essential oils from four medicinal plants against Ixodes ricinus nymphs (Acari: Ixodidae).

    Science.gov (United States)

    El-Seedi, Hesham R; Khalil, Nasr S; Azeem, Muhammad; Taher, Eman A; Göransson, Ulf; Pålsson, Katinka; Borg-Karlson, Anna-Karin

    2012-09-01

    In our search for effective tick repellents from plant origin, we investigated the effect of essential oils of four medicinal and culinary plants belonging to the family Lamiaceae on nymphs of the tick Ixodes ricinus (L.). The essential oils of the dry leaves of Rosmarinus officinalis (Rosemary) (L.), Mentha spicata (Spearmint) (L.), Origanum majorana (Majoram) (L.), and Ocimum basilicum (Basil) (L.) were isolated by steam distillation and 15 microg/cm2 concentration of oils was tested against ticks in a laboratory bioassay. The oils of R. officinalis, M. spicata, and O. majorana showed strong repellency against the ticks 100, 93.2, and 84.3%, respectively, whereas O. basilicum only showed 64.5% repellency. When tested in the field, the oils of R. officinalis and M. spicata showed 68.3 and 59.4% repellency at a concentration of 6.5 microg/cm2 on the test cloths. The oils were analyzed by gas chromatography mass spectrometry and the major compounds from the most repellent oils were 1,8-cineole, camphor, linalool, 4-terpineol, borneol, and carvone.

  11. Characterization of Ixodes ricinus Fibrinogen-Related Proteins (Ixoderins Discloses Their Function in the Tick Innate Immunity

    Directory of Open Access Journals (Sweden)

    Helena Honig Mondekova

    2017-12-01

    Full Text Available Ticks are important vectors of serious human and animal disease-causing organisms, but their innate immunity can fight invading pathogens and may have the ability to reduce or block transmission to mammalian hosts. Lectins, sugar-binding proteins, can distinguish between self and non-self-oligosaccharide motifs on pathogen surfaces. Although tick hemolymph possesses strong lectin activity, and several lectins have already been isolated and characterized, little is known about the implementation of these molecules in tick immunity. Here, we have described and functionally characterized fibrinogen-related protein (FReP lectins in Ixodes ticks. We have shown that the FReP family contains at least 27 genes (ixoderins, ixo that could, based on phylogenetic and expression analyses, be divided into three groups with differing degrees of expansion. By using RNA interference-mediated gene silencing (RNAi we demonstrated that IXO-A was the main lectin in tick hemolymph. Further, we found that ixoderins were important for phagocytosis of Gram-negative bacteria and yeasts by tick hemocytes and that their expression was upregulated upon injection of microbes, wounding, or after blood feeding. However, although the tick hemocytes could swiftly phagocytose Borrelia afzelii spirochetes, their transmission and burst of infection in mice was not altered. Our results demonstrate that tick ixoderins are crucial immune proteins that work as opsonins in the tick hemolymph, targeting microbes for phagocytosis or lysis.

  12. Bat ticks revisited: Ixodes ariadnae sp. nov. and allopatric genotypes of I. vespertilionis in caves of Hungary.

    Science.gov (United States)

    Hornok, Sándor; Kontschán, Jenő; Kováts, Dávid; Kovács, Richárd; Angyal, Dorottya; Görföl, Tamás; Polacsek, Zsolt; Kalmár, Zsuzsa; Mihalca, Andrei D

    2014-04-27

    In Europe two ixodid bat tick species, Ixodes vespertilionis and I. simplex were hitherto known to occur. Bat ticks were collected from cave walls and bats in Hungary. Their morphology and genotypes were compared with microscopy and conventional PCR (followed by sequencing), respectively. A year-round activity of I. vespertilionis was observed. Molecular analysis of the cytochrome oxidase subunit I (COI) gene of twenty ticks from different caves showed that the occurrence of the most common genotype was associated with the caves close to each other. A few specimens of a morphologically different tick variant were also found and their COI analysis revealed only 86-88% sequence homology with I. simplex and I. vespertilionis, respectively. The microenvironment of caves (well separated from each other) appears to support the existence of allopatric I. vespertilionis COI genotypes, most likely related to the distance between caves and to bat migration over-bridging certain caves. The name I. ariadnae sp. nov. is given to the new tick species described here for the first time.

  13. Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus

    Science.gov (United States)

    Genchi, Marco; Prati, Paola; Vicari, Nadia; Manfredini, Andrea; Sacchi, Luciano; Clementi, Emanuela; Bandi, Claudio; Epis, Sara; Fabbi, Massimo

    2015-01-01

    Background Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results. Objective The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus. Results Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes. Conclusions These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents), that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view. PMID:26244842

  14. Francisella tularensis: No Evidence for Transovarial Transmission in the Tularemia Tick Vectors Dermacentor reticulatus and Ixodes ricinus.

    Directory of Open Access Journals (Sweden)

    Marco Genchi

    Full Text Available Tularemia is a zoonosis caused by the Francisella tularensis, a highly infectious Gram-negative coccobacillus. Due to easy dissemination, multiple routes of infection, high environmental contamination and morbidity and mortality rates, Francisella is considered a potential bioterrorism threat and classified as a category A select agent by the CDC. Tick bites are among the most prevalent modes of transmission, and ticks have been indicated as a possible reservoir, although their reservoir competence has yet to be defined. Tick-borne transmission of F. tularensis was recognized in 1923, and transstadial transmission has been demonstrated in several tick species. Studies on transovarial transmission, however, have reported conflicting results.The aim of this study was to evaluate the role of ticks as reservoirs for Francisella, assessing the transovarial transmission of F. tularensis subsp. holarctica in ticks, using experimentally-infected females of Dermacentor reticulatus and Ixodes ricinus.Transmission electron microscopy and fluorescence in situ hybridization showed F. tularensis within oocytes. However, cultures and bioassays of eggs and larvae were negative; in addition, microscopy techniques revealed bacterial degeneration/death in the oocytes.These results suggest that bacterial death might occur in oocytes, preventing the transovarial transmission of Francisella. We can speculate that Francisella does not have a defined reservoir, but that rather various biological niches (e.g. ticks, rodents, that allow the bacterium to persist in the environment. Our results, suggesting that ticks are not competent for the bacterium vertical transmission, are congruent with this view.

  15. Ir-LBP, an ixodes ricinus tick salivary LTB4-binding lipocalin, interferes with host neutrophil function.

    Directory of Open Access Journals (Sweden)

    Jérôme Beaufays

    Full Text Available BACKGROUND: During their blood meal, ticks secrete a wide variety of proteins that can interfere with their host's defense mechanisms. Among these proteins, lipocalins play a major role in the modulation of the inflammatory response. METHODOLOGY/PRINCIPAL FINDINGS: We previously identified 14 new lipocalin genes in the tick Ixodes ricinus. One of them codes for a protein that specifically binds leukotriene B4 with a very high affinity (Kd: +/-1 nM, similar to that of the neutrophil transmembrane receptor BLT1. By in silico approaches, we modeled the 3D structure of the protein and the binding of LTB4 into the ligand pocket. This protein, called Ir-LBP, inhibits neutrophil chemotaxis in vitro and delays LTB4-induced apoptosis. Ir-LBP also inhibits the host inflammatory response in vivo by decreasing the number and activation of neutrophils located at the tick bite site. Thus, Ir-LBP participates in the tick's ability to interfere with proper neutrophil function in inflammation. CONCLUSIONS/SIGNIFICANCE: These elements suggest that Ir-LBP is a "scavenger" of LTB4, which, in combination with other factors, such as histamine-binding proteins or proteins inhibiting the classical or alternative complement pathways, permits the tick to properly manage its blood meal. Moreover, with regard to its properties, Ir-LBP could possibly be used as a therapeutic tool for illnesses associated with an increased LTB4 production.

  16. The occurrence of Spotted Fever Group (SFG) Rickettsiae in Ixodes ricinus ticks (Acari: Ixodidae) in northern Poland.

    Science.gov (United States)

    Stańczak, Joanna

    2006-10-01

    Ixodes ricinus, the most commonly observed tick species in Poland, is known vector of microorganisms pathogenic for humans as TBE virus, Borrelia burgdorferi s.1., Anaplasma phagocytophilum and Babesia sp. in this country. Our study aimed to find out whether this tick can also transmit also rickettsiae of the spotted fever group (SFG). DNA extracts from 560 ticks (28 females, 34 males, and 488 nymphs) collected in different wooded areas in northern Poland were examined by PCR for the detection of Rickettsia sp., using a primer set RpCS.877p and RpCS.1258n designated to amplify a 381-bp fragment of gltA gene. A total of 2.9% ticks was found to be positive. The percentage of infected females and males was comparable (10.5% and 11.8%, respectively) and 6.6-7.6 times higher than in nymphs (1.6%). Sequences of four PCR-derived DNA fragments (acc. no. DQ672603) demonstrated 99% similarity with the sequence of Rickettsia helvetica deposited in GenBank. The results obtained suggest the possible role of I. ricinus as a source of a microorganism, which recently has been identified as an agent of human rickettsioses in Europe.

  17. 'Candidatus Rickettsia mendelii', a novel basal group rickettsia detected in Ixodes ricinus ticks in the Czech Republic.

    Science.gov (United States)

    Hajduskova, Eva; Literak, Ivan; Papousek, Ivo; Costa, Francisco B; Novakova, Marketa; Labruna, Marcelo B; Zdrazilova-Dubska, Lenka

    2016-04-01

    A novel rickettsial sequence in the citrate synthase gltA gene indicating a novel Rickettsia species has been detected in 7 out of 4524 Ixodes ricinus ticks examined within several surveys performed in the Czech Republic from 2005 to 2009. This new Candidatus Rickettsia sp. sequence has been found in 2 nymphs feeding on wild birds (Luscinia megarhynchos and Erithacus rubecula), in a male tick from vegetation, and 4 ticks feeding on a dog (3 males, 1 female tick). Portions of the ompA, ompB, sca4, and htrA genes were not amplifiable in these samples. A maximum likelihood tree of rickettsiae based on comparisons of partial amino acid sequences of citrate synthase and nucleotide sequences of 16S rDNA genes and phylogenetic analysis revealed a basal position of the novel species in the proximity of R. bellii and R. canadensis. The novel species has been named 'Candidatus Rickettsia mendelii' after the founder of genetics, Gregor Mendel. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Detection of Rickettsia helvetica and Candidatus R. tarasevichiae DNA in Ixodes persulcatus ticks collected in Northeastern European Russia (Komi Republic).

    Science.gov (United States)

    Kartashov, Mikhail Yu; Glushkova, Ludmila I; Mikryukova, Tamara P; Korabelnikov, Igor V; Egorova, Yulia I; Tupota, Natalia L; Protopopova, Elena V; Konovalova, Svetlana N; Ternovoi, Vladimir A; Loktev, Valery B

    2017-06-01

    The number of tick-borne infections in the northern European regions of Russia has increased considerably in the last years. In the present study, 676 unfed adult Ixodes persulcatus ticks were collected in the Komi Republic from 2011 to 2013 to study tick-borne rickettsioses. Rickettsia spp. DNA was detected by PCR in 51 (7.6%) ticks. The nucleotide sequence analysis of gltA fragments (765bp) from 51 ticks indicated that 60.8% and 39.2% of the ticks were infected with Rickettsia helvetica and Candidatus R. tarasevichiae, respectively. The gltA fragments showed 100% identity with those of Candidatus R. tarasevichiae previously discovered in Siberia and China, whereas R. helvetica showed 99.9% sequence identity with European isolates. The ompB had 8 nucleotide substitutions, 6 of which resulted in amino acid substitutions. In the sca9 gene, 3 nucleotide substitutions were detected, and only one resulted in amino acid substitution. The smpA, ompW, and β-lactamase genes of R. helvetica also showed a high level of sequence identity. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. First evidence of Babesia venatorum and Babesia capreoli in questing Ixodes ricinus ticks in the Czech Republic.

    Science.gov (United States)

    Venclikova, Kristyna; Mendel, Jan; Betasova, Lenka; Hubalek, Zdenek; Rudolf, Ivo

    2015-01-01

    Ixodes ricinus is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of Babesia spp. in host-seeking I. ricinus in urban and natural habitats. PCR was applied on samples to assess prevalence of Babesia spp. in questing ixodid ticks. Sequencing was used for Babesia species determination. 1,473 I. ricinus ticks (1,294 nymphs, 99 males and 80 females) were examined for the presence of Babesia spp. at the two study sites. Minimum infection rate for Babesia spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem). Two Babesia species were identified by sequencing: B. venatorum (formerly called Babesia sp. EU1) and B. capreoli. The results obtained represent the first evidence of the occurrence of B. venatorum and B. capreoli in host-seeking I. ricinus ticks in the Czech Republic.

  20. An ELISA to Detect Serum Antibodies to the Salivary Gland Toxin of Ixodes holocyclus Neumann in Dogs and Rodents

    Directory of Open Access Journals (Sweden)

    S. Hall-Mendelin

    2011-01-01

    Full Text Available The Ixodes holocyclus tick causes paralysis in up to 10,000 companion and domestic animals each year in Australia. Treatment requires the removal of the parasite and the administration of a commercial tick antiserum that is prepared from hyperimmune dogs. Each batch of this serum is initially tested for toxin-neutralising potency in a mouse bioassay that is expensive, time consuming, and subjective. With the aim of developing a rapid in vitro assay to replace the bioassay, we used a partially purified antigen prepared from I. holocyclus salivary glands to develop an ELISA to detect toxin-reactive antibodies in hyperimmune dog sera. The optimised ELISA reliably detected antibodies reactive to I. holocyclus salivary gland antigens. Parallel testing of sera with a negative control antigen prepared from the salivary glands of the nontoxic tick Rhipicephalus (Boophilus microplus provided further evidence that we were detecting toxin-specific antibodies in the assay. Using the ELISA, we could also detect antibodies induced in rats after experimental infestation with I. holocyclus. This assay shows promise as an alternative means of assessing the potency of batches of hyperimmune dog serum and to screen for toxin-reactive monoclonal antibodies produced from immunised rodents.

  1. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    Science.gov (United States)

    Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

    2014-02-01

    The Gd5Ge2Si2 alloy and the off-stoichiometric Ni50Mn35In15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd5Ge2Si2 and Ni50Mn35In15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis.

  2. Hysteresis of magnetostructural transitions: Repeatable and non-repeatable processes

    International Nuclear Information System (INIS)

    Provenzano, Virgil; Della Torre, Edward; Bennett, Lawrence H.; ElBidweihy, Hatem

    2014-01-01

    The Gd 5 Ge 2 Si 2 alloy and the off-stoichiometric Ni 50 Mn 35 In 15 Heusler alloy belong to a special class of metallic materials that exhibit first-order magnetostructural transitions near room temperature. The magnetic properties of this class of materials have been extensively studied due to their interesting magnetic behavior and their potential for a number of technological applications such as refrigerants for near-room-temperature magnetic refrigeration. The thermally driven first-order transitions in these materials can be field-induced in the reverse order by applying a strong enough field. The field-induced transitions are typically accompanied by the presence of large magnetic hysteresis, the characteristics of which are a complicated function of temperature, field, and magneto-thermal history. In this study we show that the virgin curve, the major loop, and sequentially measured MH loops are the results of both repeatable and non-repeatable processes, in which the starting magnetostructural state, prior to the cycling of field, plays a major role. Using the Gd 5 Ge 2 Si 2 and Ni 50 Mn 35 In 15 alloys, as model materials, we show that a starting single phase state results in fully repeatable processes and large magnetic hysteresis, whereas a mixed phase starting state results in non-repeatable processes and smaller hysteresis

  3. Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes cinus ticks from different sites of North-Eastern Poland

    Directory of Open Access Journals (Sweden)

    Justyna Dunaj

    2014-06-01

    Full Text Available Introduction. RLB (Reverse Line Blot Hybridization is a molecular biology technique that might be used for [i]Borrelia burgdorferi [/i]sensu lato (sl DNA detection with genospecies specification. Among[i] B. burgdorferi[/i] sl genospecies at least 7 are regarded as pathogenic in Europe. objective. The aim of the study was to evaluate the frequency of different [i]Borrelia[/i] genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. materials and method. Ixodes ricinus ticks were collected in May – June, from 6 different sites in North-Eastern Poland (Jakubin, Kolno, Grajewo, Suwałki, Siemiatycze, Białowieża by flagging. Extracted DNA was amplified by polymerase chain reaction (PCR targeting the intergenic spacer 5S 23S of [i]B. burgdorferi sl.[/i] PCR products were hybridised to 15 different oligonucleotide probes for 9 different [i]Borrelia [/i]genospecies ([i]B. burgdorferi sl, B. burgdorferi ss, B. garinii, B. afzelii, B. valaisiana, B. lusitaniae, B. spielmanii, B. bissettii and B. relapsing[/i] fever-like spirochetes (B. myamotoi by RLB. results. [i]Borrelia [/i]genospecies DNA was detected in 205 Ixodes ricinus ticks. Among 14 infected with [i]Borrelia[/i] ticks, 4 were identified as B. garinii and 10 as B. afzelii. Higher numbers of infected ticks were noticed in the eastern part of the research area, where large forest complexes dominate. Nymphs appeared to be the most frequently infected tick stage, which has an epidemiological meaning in the incidence of Lyme borreliosis. conclusions. The study demonstrated that RLB might be easily used in [i]Borrelia[/i] DNA detection with genospecies-identification, and indicated the domination of [i]B. afzelii and B. garinii [/i]in ticks from North-Eastern Poland.

  4. Coordination in continuously repeated games

    NARCIS (Netherlands)

    Weeren, A.J.T.M.; Schumacher, J.M.; Engwerda, J.C.

    1995-01-01

    In this paper we propose a model to describe the effectiveness of coordination in a continuously repeated two-player game. We study how the choice of a decision rule by a coordinator affects the strategic behavior of the players, resulting in more or less cooperation. Our model requires the analysis

  5. Repeated checking causes memory distrust

    NARCIS (Netherlands)

    van den Hout, M.; Kindt, M.

    2003-01-01

    This paper attempts to explain why in obsessive-compulsive disorder (OCD) checkers distrust in memory persists despite extensive checking. It is argued that: (1) repeated checking increases familiarity with the issues checked; (2) increased familiarity promotes conceptual processing which inhibits

  6. Borrelia burgdorferi genospecies detection by RLB hybridization in Ixodes cinus ticks from different sites of North-Eastern Poland

    OpenAIRE

    Justyna Dunaj; Joanna Maria Zajkowska; Maciej Kondrusik; Lise Gern; Oliver Rais; Anna Moniuszko; Sławomir Pancewicz; Renata Świerzbińska

    2014-01-01

    Introduction. RLB (Reverse Line Blot Hybridization) is a molecular biology technique that might be used for [i]Borrelia burgdorferi [/i]sensu lato (sl) DNA detection with genospecies specification. Among[i] B. burgdorferi[/i] sl genospecies at least 7 are regarded as pathogenic in Europe. objective. The aim of the study was to evaluate the frequency of different [i]Borrelia[/i] genospecies DNA detection in Ixodes ricinus ticks in the endemic area of North-Eastern Poland by using RLB. ...

  7. Thioester-containing proteins of the tick Ixodes ricinus: Gene expression, response to microbial challenge and their role in phagocytosis of the yeast Candida albicans

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Veronika; Šíma, Radek; Šauman, Ivo; Hajdušek, Ondřej; Kopáček, Petr

    2015-01-01

    Roč. 48, č. 1 (2015), s. 55-64 ISSN 0145-305X R&D Projects: GA ČR GAP506/10/2136; GA ČR GA13-11043S; GA ČR GP13-27630P; GA ČR GP13-12816P; GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) 316304 - MODBIOLIN Institutional support: RVO:60077344 Keywords : Candida albicans * Complement * Innate immunity * Phagocytosis * Thioester-containing proteins * Tick Ixodes ricinus Subject RIV: EC - Immunology Impact factor: 3.620, year: 2015

  8. Detection of Borrelia lusitaniae, Rickettsia sp. IRS3, Rickettsia monacensis, and Anaplasma phagocytophilum in Ixodes ricinus collected in Madeira Island, Portugal.

    Science.gov (United States)

    de Carvalho, Isabel Lopes; Milhano, Natacha; Santos, Ana Sofia; Almeida, Victor; Barros, Silvia C; De Sousa, Rita; Núncio, Maria Sofia

    2008-08-01

    A total of 300 Ixodes ricinus ticks were tested by polymerase chain reaction (PCR) for the presence of Borrelia spp., Rickettsia spp., and Anaplasma phagocytophilum. Sequence analysis demonstrated 8 (2.7%) ticks infected with B. lusitaniae, 60 (20%) with Rickettsia spp., and 1 (0.3%) with A. phagocytophilum. Seven (2.3%) ticks were coinfected with B. lusitaniae and Rickettsia spp., 2 (0.6%) with R. monacensis, and 5 (1.7%) with Rickettsia sp. IRS3. The results of this study suggest simultaneous transmission of multiple tick-borne agents on Madeira Island, Portugal.

  9. Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden

    Directory of Open Access Journals (Sweden)

    Jaenson Thomas GT

    2012-01-01

    Full Text Available Abstract Background Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB spirochaetes, the tick-borne encephalitis virus (TBEV and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. Methods A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Results Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the

  10. Changes in the geographical distribution and abundance of the tick Ixodes ricinus during the past 30 years in Sweden.

    Science.gov (United States)

    Jaenson, Thomas G T; Jaenson, David G E; Eisen, Lars; Petersson, Erik; Lindgren, Elisabet

    2012-01-10

    Ixodes ricinus is the main vector in Europe of human-pathogenic Lyme borreliosis (LB) spirochaetes, the tick-borne encephalitis virus (TBEV) and other pathogens of humans and domesticated mammals. The results of a previous 1994 questionnaire, directed at people living in Central and North Sweden (Svealand and Norrland) and aiming to gather information about tick exposure for humans and domestic animals, suggested that Ixodes ricinus ticks had become more widespread in Central Sweden and the southern part of North Sweden from the early 1980s to the early 1990s. To investigate whether the expansion of the tick's northern geographical range and the increasing abundance of ticks in Sweden were still occurring, in 2009 we performed a follow-up survey 16 years after the initial study. A questionnaire similar to the one used in the 1994 study was published in Swedish magazines aimed at dog owners, home owners, and hunters. The questionnaire was published together with a popular science article about the tick's biology and role as a pathogen vector in Sweden. The magazines were selected to get information from people familiar with ticks and who spend time in areas where ticks might be present. Analyses of data from both surveys revealed that during the near 30-year period from the early 1980s to 2008, I. ricinus has expanded its distribution range northwards. In the early 1990s ticks were found in new areas along the northern coastline of the Baltic Sea, while in the 2009 study, ticks were reported for the first time from many locations in North Sweden. This included locations as far north as 66°N and places in the interior part of North Sweden. During this 16-year period the tick's range in Sweden was estimated to have increased by 9.9%. Most of the range expansion occurred in North Sweden (north of 60°N) where the tick's coverage area doubled from 12.5% in the early 1990s to 26.8% in 2008. Moreover, according to the respondents, the abundance of ticks had increased

  11. Molecular detection and phylogenetic analysis of Hepatozoon spp. in questing Ixodes ricinus ticks and rodents from Slovakia and Czech Republic.

    Science.gov (United States)

    Hamšíková, Zuzana; Silaghi, Cornelia; Rudolf, Ivo; Venclíková, Kristýna; Mahríková, Lenka; Slovák, Mirko; Mendel, Jan; Blažejová, Hana; Berthová, Lenka; Kocianová, Elena; Hubálek, Zdeněk; Schnittger, Leonhard; Kazimírová, Mária

    2016-10-01

    By amplification and sequencing of 18S rRNA gene fragments, Hepatozoon spp. DNA was detected in 0.08 % (4/5057) and 0.04 % (1/2473) of questing Ixodes ricinus ticks from Slovakia and Czech Republic, respectively. Hepatozoon spp. DNA was also detected in spleen and/or lungs of 4.45 % (27/606) of rodents from Slovakia. Prevalence of infection was significantly higher in Myodes glareolus (11.45 %) than in Apodemus spp. (0.28 %) (P Hepatozoon spp. gene amplicons from I. ricinus showed 100 % identity with Hepatozoon canis isolates from red foxes or dogs in Europe. Phylogenetic analysis showed that at least two H. canis 18S rRNA genotypes exist in Slovakia of which one was identified also in the Czech Republic. The finding of H. canis in questing I. ricinus suggests the geographical spread of the parasite and a potential role of other ticks as its vectors in areas where Rhipicephalus sanguineus is not endemic. Sequencing of 18S rRNA gene amplicons from M. glareolus revealed the presence of two closely related genetic variants, Hepatozoon sp. SK1 and Hepatozoon sp. SK2, showing 99-100 % identity with isolates from M. glareolus from other European countries. Phylogenetic analysis demonstrates that 18S rRNA variants SK1 and SK2 correspond to previously described genotypes UR1 and UR2 of H. erhardovae, respectively. The isolate from Apodemus flavicollis (Hepatozoon sp. SK3b) was 99 % identical with isolates from reptiles in Africa and Asia. Further studies are necessary to identify the taxonomic status of Hepatozoon spp. parasitizing rodents in Europe and the host-parasite interactions in natural foci.

  12. Modelling the Phenological Relationships of Questing Immature Ixodes Ricinus (Ixodidae) Using Temperature and NDVI Data.

    Science.gov (United States)

    Alonso-Carné, J; García-Martín, A; Estrada-Peña, A

    2016-02-01

    All active stages of the tick Ixodes ricinus were collected monthly at two sites in northern Spain between the years 2000 and 2007. We used percentile accumulation of the active stage in the environment to evaluate simple and coherent correlations between accumulation of the active stages of larvae and nymphs and medium-resolution MODIS satellite-derived information on the climate, including monthly and accumulated temperature and the Normalized Difference Vegetation Index (NDVI). This framework is not intended to predict the actual abundance of ticks in the field as a measure of the hazard to humans, but to provide a basic structure for addressing the phenology of the tick in its geographic range. We demonstrated that the accumulation of larval ticks in the active stage is a sigmoid function of the accumulated temperature from the beginning of the calendar year. We also demonstrated that the accumulated temperature necessary to recruit nymphs from the questing larval stage is a function of the changes in accumulated larvae and nymphs and the accumulated temperature and NDVI recorded by the Aqua sensor. The low p-values obtained in the regressions confirmed that such recruitment can be calculated using time intervals to estimate, for example, the beginning of the questing period or the time of the year when a population peak can be expected. The comparison among predicted and actual accumulated temperatures between larvae and nymph recruitment had an averaged error of ±20 days in one complete year. The use of accumulated temperature and NDVI proposed in this study opens up the re-evaluation of reports on the phenology of the tick in Europe. This framework is intended to evaluate the same correlations along the tick's range and predict its phenological patterns in areas of pathogen transmission risk for humans. © 2015 Blackwell Verlag GmbH.

  13. The integration of multiple independent data reveals an unusual response to Pleistocene climatic changes in the hard tick Ixodes ricinus.

    Science.gov (United States)

    Porretta, Daniele; Mastrantonio, Valentina; Mona, Stefano; Epis, Sara; Montagna, Matteo; Sassera, Davide; Bandi, Claudio; Urbanelli, Sandra

    2013-03-01

    In the last few years, improved analytical tools and the integration of genetic data with multiple sources of information have shown that temperate species exhibited more complex responses to ice ages than previously thought. In this study, we investigated how Pleistocene climatic changes affected the current distribution and genetic diversity of European populations of the tick Ixodes ricinus, an ectoparasite with high ecological plasticity. We first used mitochondrial and nuclear genetic markers to investigate the phylogeographic structure of the species and its Pleistocene history using coalescent-based methods; then we used species distribution modelling to infer the climatic niche of the species at last glacial maximum; finally, we reviewed the literature on the I. ricinus hosts to identify the locations of their glacial refugia. Our results support the scenario that during the last glacial phase, I. ricinus never experienced a prolonged allopatric divergence in separate glacial refugia, but persisted with interconnected populations across Southern and Central Europe. The generalist behaviour in host choice of I. ricinus would have played a major role in maintaining connections between its populations. Although most of the hosts persisted in separate refugia, from the point of view of I. ricinus, they represented a continuity of 'bridges' among populations. Our study highlights the importance of species-specific ecology in affecting responses to Pleistocene glacial-interglacial cycles. Together with other cases in Europe and elsewhere, it contributes to setting new hypotheses on how species with wide ecological plasticity coped with Pleistocene climatic changes. © 2013 Blackwell Publishing Ltd.

  14. Spotted fever Rickettsia species in Hyalomma and Ixodes ticks infesting migratory birds in the European Mediterranean area

    Science.gov (United States)

    2014-01-01

    Background A few billion birds migrate annually between their breeding grounds in Europe and their wintering grounds in Africa. Many bird species are tick-infested, and as a result of their innate migratory behavior, they contribute significantly to the geographic distribution of pathogens, including spotted fever rickettsiae. The aim of the present study was to characterize, in samples from two consecutive years, the potential role of migrant birds captured in Europe as disseminators of Rickettsia-infected ticks. Methods Ticks were collected from a total of 14,789 birds during their seasonal migration northwards in spring 2009 and 2010 at bird observatories on two Mediterranean islands: Capri and Antikythira. All ticks were subjected to RNA extraction followed by cDNA synthesis and individually assayed with a real-time PCR targeting the citrate synthase (gltA) gene. For species identification of Rickettsia, multiple genes were sequenced. Results Three hundred and ninety-eight (2.7%) of all captured birds were tick-infested; some birds carried more than one tick. A total number of 734 ticks were analysed of which 353 ± 1 (48%) were Rickettsia-positive; 96% were infected with Rickettsia aeschlimannii and 4% with Rickettsia africae or unidentified Rickettsia species. The predominant tick taxon, Hyalomma marginatum sensu lato constituted 90% (n = 658) of the ticks collected. The remaining ticks were Ixodes frontalis, Amblyomma sp., Haemaphysalis sp., Rhipicephalus sp. and unidentified ixodids. Most ticks were nymphs (66%) followed by larvae (27%) and adult female ticks (0.5%). The majority (65%) of ticks was engorged and nearly all ticks contained visible blood. Conclusions Migratory birds appear to have a great impact on the dissemination of Rickettsia-infected ticks, some of which may originate from distant locations. The potential ecological, medical and veterinary implications of such Rickettsia infections need further examination. PMID:25011617

  15. Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

    Directory of Open Access Journals (Sweden)

    Gaasenbeek Cor

    2009-09-01

    Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

  16. Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East.

    Science.gov (United States)

    Igolkina, Y; Bondarenko, E; Rar, V; Epikhina, T; Vysochina, N; Pukhovskaya, N; Tikunov, A; Ivanov, L; Golovljova, I; Ivanov, М; Tikunova, N

    2016-10-01

    Rickettsia spp. are intracellular Gram-negative bacteria transmitted by arthropods. Two potentially pathogenic rickettsiae, Candidatus Rickettsia tarasevichiae and Rickettsia helvetica, have been found in unfed adult Ixodes persulcatus ticks. The aim of this study was to assess the prevalence and genetic variability of Rickettsia spp. in I. persulcatus ticks collected from different locations in the Russian Far East. In total, 604 adult I. persulcatus ticks collected from four sites in the Khabarovsk Territory (continental area) and one site in Sakhalin Island were examined for the presence of Rickettsia spp. by real-time PCR. Nested PCR with species-specific primers and sequencing were used for genotyping of revealed rickettsiae. The overall prevalence of Rickettsia spp. in ticks collected in different sites varied from 67.9 to 90.7%. However, the proportion of different Rickettsia species observed in ticks from Sakhalin Island significantly differed from that in ticks from the Khabarovsk Territory. In Sakhalin Island, R. helvetica prevailed in examined ticks, while Candidatus R. tarasevichiae was predominant in the Khabarovsk Territory. For gltA and ompB gene fragments, the sequences obtained for Candidatus R. tarasevichiae from all studied sites were identical to each other and to the known sequences of this species. According to sequence analysis of gltA, оmpB and sca4 genes, R. helvetica isolates from Sakhalin Island and the Khabarovsk Territory were identical to each other, but they differed from R. helvetica from other regions and from those found in other tick species. For the first time, DNA of pathogenic Rickettsia heilongjiangensis was detected in I. persulcatus ticks in two sites from the Khabarovsk Territory. The gltA, ompA and оmpB gene sequences of R. heilongjiangensis were identical to or had solitary mismatches with the corresponding sequences of R. heilongjiangensis found in other tick species. Copyright © 2016 Elsevier GmbH. All rights

  17. Diversity of Babesia and Rickettsia species in questing Ixodes ricinus: a longitudinal study in urban, pasture, and natural habitats.

    Science.gov (United States)

    Overzier, Evelyn; Pfister, Kurt; Thiel, Claudia; Herb, Ingrid; Mahling, Monia; Silaghi, Cornelia

    2013-08-01

    In a previous study, our group investigated the Babesia spp. prevalence in questing Ixodes ricinus ticks from nine city parks in South Germany in the years 2009 and 2010. We showed predominant prevalence of B. venatorum (in previous literature also known as Babesia sp. EU1), especially in those parks in a more natural condition and with occurrence of large wild animals, such as roe deer. To obtain longitudinal data and to broaden the knowledge about this pathogen, further investigations were carried out in 2011 and 2012 in four of those city parks. Two additional habitat types were chosen for comparison of prevalence data and species analysis focusing on occurrence of potential reservoir hosts. A total of 10,303 questing I. ricinus were collected in four city parks, a pasture, and a natural area in Bavaria, and a representative number of samples were investigated for prevalence of DNA of Babesia spp. (n=4381) and Rickettsia spp. (n=2186) by PCR. In the natural and pasture area, a significantly higher Babesia spp. prevalence compared to the urban area was detected. The natural area revealed sequences of B. microti, B. venatorum, and B. capreoli. In the pasture and urban habitat, predominantly B. venatorum was found, whereas B. capreoli was less frequent and only one B. microti-infected tick was found. All B. microti sequences were 100% identical to the zoonotic Jena/Germany strain. For Rickettsia spp., the significantly highest prevalence was also detected in the natural and pasture areas, whereas lower prevalence was found in the urban area. Sequence analysis revealed R. helvetica (98%) and R. monacensis (2%). Prevalence rates and occurrence of Babesia spp. and Rickettsia spp. differed in urban, pasture and natural sites, most likely depending on the habitat structure (natural or cultivated) and therefore on the appearance and availability of reservoir hosts like roe deer or small mammals.

  18. Behavioral asymmetries in ticks - Lateralized questing of Ixodes ricinus to a mechatronic apparatus delivering host-borne cues.

    Science.gov (United States)

    Benelli, Giovanni; Romano, Donato; Rocchigiani, Guido; Caselli, Alice; Mancianti, Francesca; Canale, Angelo; Stefanini, Cesare

    2018-02-01

    Ticks are considered among the most dangerous arthropod vectors of disease agents to both humans and animals worldwide. Lateralization contributes to biological fitness in many animals, conferring important functional advantages, therefore studying its role in tick perception would critically improve our knowledge about their host-seeking behavior. In this research, we evaluated if Ixodes ricinus (L.) (Ixodiidae) ticks have a preference in using the right or the left foreleg to climb on a host. We developed a mechatronic device moving a tuft of fox skin with fur as host-mimicking combination of cues. This engineered approach allows to display a realistic combination of both visual and olfactory host-borne stimuli, which is prolonged over the time and standardized for each replicate. In the first experiment, the mechatronic apparatus delivered host-borne cues frontally, to evaluate the leg preference during questing as response to a symmetrical stimulus. In the second experiment, host-borne cues were provided laterally, in an equal proportion to the left and to the right of the tick, to investigate if the host direction affected the questing behavior. In both experiments, the large majority of the tested ticks showed individual-level left-biased questing acts, if compared to the ticks showing right-biased ones. Furthermore, population-level left-biased questing responses were observed post-exposure to host-mimicking cues provided frontally or laterally to the tick. Overall, this is the first report on behavioral asymmetries in ticks of medical and veterinary importance. Moreover, the mechatronic apparatus developed in this research can be exploited to evaluate the impact of repellents on tick questing in highly reproducible standardized conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Online learning in repeated auctions

    OpenAIRE

    Weed, Jonathan; Perchet, Vianney; Rigollet, Philippe

    2015-01-01

    Motivated by online advertising auctions, we consider repeated Vickrey auctions where goods of unknown value are sold sequentially and bidders only learn (potentially noisy) information about a good's value once it is purchased. We adopt an online learning approach with bandit feedback to model this problem and derive bidding strategies for two models: stochastic and adversarial. In the stochastic model, the observed values of the goods are random variables centered around the true value of t...

  20. A repeating fast radio burst.

    Science.gov (United States)

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  1. Improving repeatability by improving quality

    Energy Technology Data Exchange (ETDEWEB)

    Ronen, Shuki; Ackers, Mark; Schlumberger, Geco-Prakla; Brink, Mundy

    1998-12-31

    Time lapse (4-D) seismic is a promising tool for reservoir characterization and monitoring. The method is apparently simple: to acquire data repeatedly over the same reservoir, process and interpret the data sets, then changes between the data sets indicate changes in the reservoir. A problem with time lapse seismic data is that reservoirs are a relatively small part of the earth and important reservoir changes may cause very small differences to the time lapse data. The challenge is to acquire and process economical time lapse data such that reservoir changes can be detected above the noise of varying acquisition and environment. 7 refs., 9 figs.

  2. Telomerase Repeated Amplification Protocol (TRAP).

    Science.gov (United States)

    Mender, Ilgen; Shay, Jerry W

    2015-11-20

    Telomeres are found at the end of eukaryotic linear chromosomes, and proteins that bind to telomeres protect DNA from being recognized as double-strand breaks thus preventing end-to-end fusions (Griffith et al. , 1999). However, due to the end replication problem and other factors such as oxidative damage, the limited life span of cultured cells (Hayflick limit) results in progressive shortening of these protective structures (Hayflick and Moorhead, 1961; Olovnikov, 1973). The ribonucleoprotein enzyme complex telomerase-consisting of a protein catalytic component hTERT and a functional RNA component hTR or hTERC - counteracts telomere shortening by adding telomeric repeats to the end of chromosomes in ~90% of primary human tumors and in some transiently proliferating stem-like cells (Shay and Wright, 1996; Shay and Wright, 2001). This results in continuous proliferation of cells which is a hallmark of cancer. Therefore, telomere biology has a central role in aging, cancer progression/metastasis as well as targeted cancer therapies. There are commonly used methods in telomere biology such as Telomere Restriction Fragment (TRF) (Mender and Shay, 2015b), Telomere Repeat Amplification Protocol (TRAP) and Telomere dysfunction Induced Foci (TIF) analysis (Mender and Shay, 2015a). In this detailed protocol we describe Telomere Repeat Amplification Protocol (TRAP). The TRAP assay is a popular method to determine telomerase activity in mammalian cells and tissue samples (Kim et al. , 1994). The TRAP assay includes three steps: extension, amplification, and detection of telomerase products. In the extension step, telomeric repeats are added to the telomerase substrate (which is actually a non telomeric oligonucleotide, TS) by telomerase. In the amplification step, the extension products are amplified by the polymerase chain reaction (PCR) using specific primers (TS upstream primer and ACX downstream primer) and in the detection step, the presence or absence of telomerase is

  3. Coordinated hybrid automatic repeat request

    KAUST Repository

    Makki, Behrooz

    2014-11-01

    We develop a coordinated hybrid automatic repeat request (HARQ) approach. With the proposed scheme, if a user message is correctly decoded in the first HARQ rounds, its spectrum is allocated to other users, to improve the network outage probability and the users\\' fairness. The results, which are obtained for single- and multiple-antenna setups, demonstrate the efficiency of the proposed approach in different conditions. For instance, with a maximum of M retransmissions and single transmit/receive antennas, the diversity gain of a user increases from M to (J+1)(M-1)+1 where J is the number of users helping that user.

  4. Habitat properties are key drivers of Borrelia burgdorferi (s.l.) prevalence in Ixodes ricinus populations of deciduous forest fragments.

    Science.gov (United States)

    Ehrmann, Steffen; Ruyts, Sanne C; Scherer-Lorenzen, Michael; Bauhus, Jürgen; Brunet, Jörg; Cousins, Sara A O; Deconchat, Marc; Decocq, Guillaume; De Frenne, Pieter; De Smedt, Pallieter; Diekmann, Martin; Gallet-Moron, Emilie; Gärtner, Stefanie; Hansen, Karin; Kolb, Annette; Lenoir, Jonathan; Lindgren, Jessica; Naaf, Tobias; Paal, Taavi; Panning, Marcus; Prinz, Maren; Valdés, Alicia; Verheyen, Kris; Wulf, Monika; Liira, Jaan

    2018-01-08

    The tick Ixodes ricinus has considerable impact on the health of humans and other terrestrial animals because it transmits several tick-borne pathogens (TBPs) such as B. burgdorferi (sensu lato), which causes Lyme borreliosis (LB). Small forest patches of agricultural landscapes provide many ecosystem services and also the disservice of LB risk. Biotic interactions and environmental filtering shape tick host communities distinctively between specific regions of Europe, which makes evaluating the dilution effect hypothesis and its influence across various scales challenging. Latitude, macroclimate, landscape and habitat properties drive both hosts and ticks and are comparable metrics across Europe. Therefore, we instead assess these environmental drivers as indicators and determine their respective roles for the prevalence of B. burgdorferi in I. ricinus. We sampled I. ricinus and measured environmental properties of macroclimate, landscape and habitat quality of forest patches in agricultural landscapes along a European macroclimatic gradient. We used linear mixed models to determine significant drivers and their relative importance for nymphal and adult B. burgdorferi prevalence. We suggest a new prevalence index, which is pool-size independent. During summer months, our prevalence index varied between 0 and 0.4 per forest patch, indicating a low to moderate disservice. Habitat properties exerted a fourfold larger influence on B. burgdorferi prevalence than macroclimate and landscape properties combined. Increasingly available ecotone habitat of focal forest patches diluted and edge density at landscape scale amplified B. burgdorferi prevalence. Indicators of habitat attractiveness for tick hosts (food resources and shelter) were the most important predictors within habitat patches. More diverse and abundant macro- and microhabitat had a diluting effect, as it presumably diversifies the niches for tick-hosts and decreases the probability of contact between ticks

  5. Effects of global changes on the climatic niche of the tick Ixodes ricinus inferred by species distribution modelling.

    Science.gov (United States)

    Porretta, Daniele; Mastrantonio, Valentina; Amendolia, Sara; Gaiarsa, Stefano; Epis, Sara; Genchi, Claudio; Bandi, Claudio; Otranto, Domenico; Urbanelli, Sandra

    2013-09-19

    Global climate change can seriously impact on the epidemiological dynamics of vector-borne diseases. In this study we investigated how future climatic changes could affect the climatic niche of Ixodes ricinus (Acari, Ixodida), among the most important vectors of pathogens of medical and veterinary concern in Europe. Species Distribution Modelling (SDM) was used to reconstruct the climatic niche of I. ricinus, and to project it into the future conditions for 2050 and 2080, under two scenarios: a continuous human demographic growth and a severe increase of gas emissions (scenario A2), and a scenario that proposes lower human demographic growth than A2, and a more sustainable gas emissions (scenario B2). Models were reconstructed using the algorithm of "maximum entropy", as implemented in the software Maxent 3.3.3e; 4,544 occurrence points and 15 bioclimatic variables were used. In both scenarios an increase of climatic niche of about two times greater than the current area was predicted as well as a higher climatic suitability under the scenario B2 than A2. Such an increase occurred both in a latitudinal and longitudinal way, including northern Eurasian regions (e.g. Sweden and Russia), that were previously unsuitable for the species. Our models are congruent with the predictions of range expansion already observed in I. ricinus at a regional scale and provide a qualitative and quantitative assessment of the future climatically suitable areas for I. ricinus at a continental scale. Although the use of SDM at a higher resolution should be integrated by a more refined analysis of further abiotic and biotic data, the results presented here suggest that under future climatic scenarios most of the current distribution area of I. ricinus could remain suitable and significantly increase at a continental geographic scale. Therefore disease outbreaks of pathogens transmitted by this tick species could emerge in previous non-endemic geographic areas. Further studies will

  6. Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany

    Directory of Open Access Journals (Sweden)

    Mahling Monia

    2011-07-01

    Full Text Available Abstract Background Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010 and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. Results The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25, B. divergens (n = 1, B. divergens/capreoli (n = 1, B. gibsoni-like (n = 1, R. helvetica (n = 272, R. monacensis IrR/Munich (n = 12 and unspecified R. monacensis (n = 1. The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27, but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. Conclusions I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green

  7. Prevalence of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks and assessment of entomological risk index at localities in Belgrade

    Directory of Open Access Journals (Sweden)

    Krstić Milena

    2016-01-01

    Full Text Available Background/Aim. The first case of human Lyme borreliosis (LB in Serbia was recorded in 1987. The number of reported LB cases has increased in the past decade. The aim of this study was to estimate the density of Ixodes ricinus (I. ricinus ticks, the prevalence of Borrelia burgdorferi sensu lato (B. burgdorferi in them, and entomological risk index (ERI at 19 Belgrade localities which were grouped into three categories (forests, parkforests, parks. The values of ERI were compared with the number of tick bites in humans. Methods. Ticks were collected monthly by using the flag hours method and the infection rate was determined by using dark field microscopy. The ERI value was calculated for each locality where the ticks were collected. The related data about tick bites was obtained from the patient protocol of the Institute of Epidemiology, Military Medical Academy, Belgrade. Results. The total number of collected ticks, the number of nymphs and the infection rates of the nymphs were significantly higher in forests (p < 0.05 than park-forests and parks. Statistically, the ERI value was significantly higher in forests than parks of Belgrade (χ2 = 7.78, p < 0.01. In March and July, the ERI value was also significantly higher in forests, than park-forests (p < 0.01 and parks (p < 0.01. May was the month with the highest ERI value in each ecological category (forests p < 0.05; park-forests p < 0.01; parks p < 0.001. However, the number of tick bites in humans did not correlate with ERI values. Conclusion. The obtained results indicate that the risk of tick bite and human exposure to B. burgdorferi sensu lato is present at all selected localities in Belgrade. For a more comprehensive Lyme disease risk assessment the method of entomological risk index assessment should be combined with other methods, taking into consideration all tick stages and the behaviour and habits of people who may get infected B. burgdorferi sensu lato.

  8. Occurrence of Babesia spp., Rickettsia spp. and Bartonella spp. in Ixodes ricinus in Bavarian public parks, Germany.

    Science.gov (United States)

    Schorn, Sabine; Pfister, Kurt; Reulen, Holger; Mahling, Monia; Silaghi, Cornelia

    2011-07-15

    Only limited information is available about the occurrence of ticks and tick-borne pathogens in public parks, which are areas strongly influenced by human beings. For this reason, Ixodes ricinus were collected in public parks of different Bavarian cities in a 2-year survey (2009 and 2010) and screened for DNA of Babesia spp., Rickettsia spp. and Bartonella spp. by PCR. Species identification was performed by sequence analysis and alignment with existing sequences in GenBank. Additionally, coinfections with Anaplasma phagocytophilum were investigated. The following prevalences were detected: Babesia spp.: 0.4% (n = 17, including one pool of two larvae) in 2009 and 0.5 to 0.7% (n = 11, including one pool of five larvae) in 2010; Rickettsia spp.: 6.4 to 7.7% (n = 285, including 16 pools of 76 larvae) in 2009. DNA of Bartonella spp. in I. ricinus in Bavarian public parks could not be identified. Sequence analysis revealed the following species: Babesia sp. EU1 (n = 25), B. divergens (n = 1), B. divergens/capreoli (n = 1), B. gibsoni-like (n = 1), R. helvetica (n = 272), R. monacensis IrR/Munich (n = 12) and unspecified R. monacensis (n = 1). The majority of coinfections were R. helvetica with A. phagocytophilum (n = 27), but coinfections between Babesia spp. and A. phagocytophilum, or Babesia spp. and R. helvetica were also detected. I. ricinus ticks in urban areas of Germany harbor several tick-borne pathogens and coinfections were also observed. Public parks are of particularly great interest regarding the epidemiology of tick-borne pathogens, because of differences in both the prevalence of pathogens in ticks as well as a varying species arrangement when compared to woodland areas. The record of DNA of a Babesia gibsoni-like pathogen detected in I. ricinus suggests that I. ricinus may harbor and transmit more Babesia spp. than previously known. Because of their high recreational value for human beings, urban green areas are likely to remain in the research focus on

  9. Multi-source analysis reveals latitudinal and altitudinal shifts in range of Ixodes ricinus at its northern distribution limit

    Directory of Open Access Journals (Sweden)

    Kristoffersen Anja B

    2011-05-01

    Full Text Available Abstract Background There is increasing evidence for a latitudinal and altitudinal shift in the distribution range of Ixodes ricinus. The reported incidence of tick-borne disease in humans is on the rise in many European countries and has raised political concern and attracted media attention. It is disputed which factors are responsible for these trends, though many ascribe shifts in distribution range to climate changes. Any possible climate effect would be most easily noticeable close to the tick's geographical distribution limits. In Norway- being the northern limit of this species in Europe- no documentation of changes in range has been published. The objectives of this study were to describe the distribution of I. ricinus in Norway and to evaluate if any range shifts have occurred relative to historical descriptions. Methods Multiple data sources - such as tick-sighting reports from veterinarians, hunters, and the general public - and surveillance of human and animal tick-borne diseases were compared to describe the present distribution of I. ricinus in Norway. Correlation between data sources and visual comparison of maps revealed spatial consistency. In order to identify the main spatial pattern of tick abundance, a principal component analysis (PCA was used to obtain a weighted mean of four data sources. The weighted mean explained 67% of the variation of the data sources covering Norway's 430 municipalities and was used to depict the present distribution of I. ricinus. To evaluate if any geographical range shift has occurred in recent decades, the present distribution was compared to historical data from 1943 and 1983. Results Tick-borne disease and/or observations of I. ricinus was reported in municipalities up to an altitude of 583 metres above sea level (MASL and is now present in coastal municipalities north to approximately 69°N. Conclusion I. ricinus is currently found further north and at higher altitudes than described in

  10. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.; Maity, A.; Mammen, E.; Yu, K.

    2009-01-01

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements

  11. Topological characteristics of helical repeat proteins

    NARCIS (Netherlands)

    Groves, M R; Barford, D

    The recent elucidation of protein structures based upon repeating amino acid motifs, including the armadillo motif, the HEAT motif and tetratricopeptide repeats, reveals that they belong to the class of helical repeat proteins. These proteins share the common property of being assembled from tandem

  12. Digital storage of repeated signals

    International Nuclear Information System (INIS)

    Prozorov, S.P.

    1984-01-01

    An independent digital storage system designed for repeated signal discrimination from background noises is described. The signal averaging is performed off-line in the real time mode by means of multiple selection of the investigated signal and integration in each point. Digital values are added in a simple summator and the result is recorded the storage device with the volume of 1024X20 bit from where it can be output on an oscillograph, a plotter or transmitted to a compUter for subsequent processing. The described storage is reliable and simple device on one base of which the systems for the nuclear magnetic resonapce signal acquisition in different experiments are developed

  13. Hungarian repeat station survey, 2010

    Directory of Open Access Journals (Sweden)

    Péter Kovács

    2013-03-01

    Full Text Available The last Hungarian repeat station survey was completed between October 2010 and February 2011. Declination, inclination and the total field were observed using one-axial DMI fluxgate magnetometer mounted on Zeiss20A theodolite and GSM 19 Overhauser magnetometer. The magnetic elements of the sites were reduced to the epoch of 2010.5 on the basis of the continuous recordings of Tihany Geophysical Observatory. In stations located far from the reference observatory, the observations were carried out in the morning and afternoon in order to decrease the effect of the distant temporal correction. To further increase the accuracy, on-site dIdD variometer has also been installed near the Aggtelek station, in the Baradla cave, during the survey of the easternmost sites. The paper presents the technical details and the results of our last campaign. The improvement of the accuracy of the temporal reduction by the use of the local variometer is also reported.

  14. Linear Synchronous Motor Repeatability Tests

    International Nuclear Information System (INIS)

    Ward, C.R.

    2002-01-01

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility

  15. Two-dimensional quantum repeaters

    Science.gov (United States)

    Wallnöfer, J.; Zwerger, M.; Muschik, C.; Sangouard, N.; Dür, W.

    2016-11-01

    The endeavor to develop quantum networks gave rise to a rapidly developing field with far-reaching applications such as secure communication and the realization of distributed computing tasks. This ultimately calls for the creation of flexible multiuser structures that allow for quantum communication between arbitrary pairs of parties in the network and facilitate also multiuser applications. To address this challenge, we propose a two-dimensional quantum repeater architecture to establish long-distance entanglement shared between multiple communication partners in the presence of channel noise and imperfect local control operations. The scheme is based on the creation of self-similar multiqubit entanglement structures at growing scale, where variants of entanglement swapping and multiparty entanglement purification are combined to create high-fidelity entangled states. We show how such networks can be implemented using trapped ions in cavities.

  16. Hybrid FRC under repeated loading

    International Nuclear Information System (INIS)

    Komlos, K.; Babal, B.; Nuernbergerova, T.

    1993-01-01

    Fibre reinforced concretes (FRC) containing several volume fractions in different ratios of two types of fibres - polypropylene and steel, were tested under repeated loading. Mechanical properties of specimens - cubes 150/150/150 mm (for compressive strength), prisms 100/100/400 (for flexural strength), short cylinders 150/60 mm (for impact strength) have been experimentally investigated before and after cyclic loading at the age of 28 days curing time. Mix proportions were designed after DIN 1045 with max. aggregate size 8 mm and grading curve B 8. Portland Cement PC 400 in the amount of 450 kg. m -3 was applied and W/C ratio 0.55. Workability of mixes was measured by Vebe method and regulated by plasticizing admixture Ligoplast Na. Maximum hybrid fibre volume fraction (polypropylene + steel) was 1.0%. Dynamic forces generated in Schenck testing machine with frequency 16 Hz had sinusoidal wave form varying between 0.7 and 0.1 of static mechanical characteristics. The number of cycles in all tests was 10 5 . The residual MOR at static four point bending test and working diagram force-deflection was carried out as well. The impact properties after repeated loading in compression were tested by means of falling weight test. Relationships between composition of fibre composites with different combination of polypropylene (0.2, 0.3, 0.5% by volume) and steel (0.5, 0.7, and 0.8% by volume) fibre content were obtained and technological properties of mixes as well. (author)

  17. Quality control during repeated fryings

    Directory of Open Access Journals (Sweden)

    Cuesta, C.

    1998-08-01

    Full Text Available Most of the debate ¡s about how the slow or frequent turnover of fresh fat affects the deterioration, of fat used in frying. Then, the modification of different oils used in repeated fryings of potatoes without or with turnover of fresh oil, under similar frying conditions, was evaluated by two criteria: by measuring the total polar component isolated by column chromatography and by the evaluation of the specific compounds related to thermoxidative and hydrolytic alteration by High Performance Size Exclusion Chromatography (HPSEC. The results indicate that with frequent turnover of fresh oil, the critical level of 25% of polar material is rarely reached, and there are fewer problems with fat deterioration because the frying tended to increase the level of polar material and thermoxidative compounds (polymers and dimers of triglycerides and oxidized triglycerides in the fryer oil during the first fryings, followed by minor changes and a tendency to reach a near-steady state in successive fryings. However, in repeated frying of potatoes using a null turnover the alteration rate was higher being linear the relationship found between polar material or the different thermoxidative compounds and the number of fryings. On the other hand chemical reactions produced during deep-fat frying can be minimized by using proper oils. In addition the increased level of consumers awareness toward fat composition and its impact on human health could had an impact on the selection of fats for snacks and for industry. In this way monoenic fats are the most adequate from a nutritional point of view and for its oxidative stability during frying.

  18. The Rare ospC Allele L of Borrelia burgdorferi Sensu Stricto, Commonly Found among Samples Collected in a Coastal Plain Area of the Southeastern United States, Is Associated with Ixodes affinis Ticks and Local Rodent Hosts Peromyscus gossypinus and Sigmodon hispidus

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor; Oliver, J. H., Jr.

    2013-01-01

    Roč. 79, č. 4 (2013), s. 1403-1406 ISSN 0099-2240 Grant - others:NIH(US) R37AI-24899 Institutional support: RVO:60077344 Keywords : lyme disease * genetic diversity * scapularis tick * Acari * North Carolina * heterogenity * polymorphism * cultivation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.952, year: 2013

  19. The parasitism of Ixodes luciae (Acari: Ixodidae on marsupials and rodents in Peruvian Amazon O parasitismo do Ixodes luciae (Acari: ixodidae em marsupiais e em roedores na Amazônia Peruana

    Directory of Open Access Journals (Sweden)

    María Mónica Díaz

    2009-01-01

    Full Text Available In this work the infestation with I. luciae on Didelphimorphia and Rodentia in different environments of Peruvian Amazon was studied. Didelphimorphia was represented by the family Didelphidae. Specimens belonging to Caluromys lanatus, Didelphis marsupialis, Marmosops sp.2, Metachirus nudicaudatus, Philander andersoni and Philander opossum were infested with adults I. luciae and one Micoureus sp. was infested with larvae. In Rodentia, the infestation with I. luciae nymphs was restricted to Hylaeamys perenensis, Hylaeamys yunganus and Oligoryzomys microtis, while one Oecomys bicolor (all Cricetidae was infested with larvae of this species. The few larvae were found on rodents captured in primary forest. The only significant difference (P No presente trabalho, infestações por Ixodes luciae em Didelphimorphia e Rodentia em diferentes ambientes da Amazônia peruana foram estudadas. Didelphimorphia foi representada pela família Didelphidae. Espécimes pertencentes a Caluromys lanatus, Didelphis marsupialis, Marmosops sp., Metachirus nudicaudatus, Philander andersoni e Philander opossum foram encontrados infestadas por adultos de I. luciae; um Micoureus sp. foi encontrado infestado por larvas. Em Rodentia, a infestação por ninfas de I. luciae estiveram restritas a Hylaeamys perenensis, Hylaeamys yunganus e Oligoryzomys microtis, enquanto que um Oecomys bicolor (todos Cricetidae esteve infestado por larvas de I. luciae. As poucas larvas foram encontradas em roedores capturados na floresta primária. A única diferença significante (P < 0.05 na prevalência de carrapatos adultos em Didelphimorphia foi entre P. andersoni e M. nudicaudatus (distribuição chi-quadrado. A distribuição de carrapatos adultos foi significativamente diferente em P. andersoni quando comparado com M. nudicaudatus, P. opossum e D. marsupialis (teste Kruskal-Wallis. Nenhum efeito significante do mês ou ambiente foi observado em relação à infestação por carrapato

  20. Ticks and tick-borne pathogens in South Bohemia (Czech Republic) – Spatial variability in Ixodes ricinus abundance, Borrelia burgdorferi and tick-borne encephalitis virus prevalence

    Czech Academy of Sciences Publication Activity Database

    Hönig, Václav; Švec, P.; Halas, Petr; Vavrušková, Zuzana; Tykalová, Hana; Kilian, Patrik; Vetišková, Vendula; Dorňáková, Veronika; Štěrbová, Jarmila; Šimonová, Zuzana; Erhart, Jan; Štěrba, Ján; Golovchenko, Maryna; Rudenko, Natalia; Grubhoffer, Libor

    2015-01-01

    Roč. 6, č. 5 (2015), s. 559-567 ISSN 1877-959X R&D Projects: GA ČR GD206/09/H026; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:68145535 ; RVO:60077344 Keywords : tick * tick-borne encephalitis * ixodes ricinus * environmental factors * lyme borreliosis Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology; EB - Genetics ; Molecular Biology (BC-A) Impact factor: 2.690, year: 2015 http://ac.els-cdn.com/S1877959X15000783/1-s2.0-S1877959X15000783-main.pdf?_tid=8785a702-8de3-11e5-bd28-00000aacb35f&acdnat=1447844587_a91b4e4d404a70fda98b06e4950edb11

  1. The leucine-rich repeat structure.

    Science.gov (United States)

    Bella, J; Hindle, K L; McEwan, P A; Lovell, S C

    2008-08-01

    The leucine-rich repeat is a widespread structural motif of 20-30 amino acids with a characteristic repetitive sequence pattern rich in leucines. Leucine-rich repeat domains are built from tandems of two or more repeats and form curved solenoid structures that are particularly suitable for protein-protein interactions. Thousands of protein sequences containing leucine-rich repeats have been identified by automatic annotation methods. Three-dimensional structures of leucine-rich repeat domains determined to date reveal a degree of structural variability that translates into the considerable functional versatility of this protein superfamily. As the essential structural principles become well established, the leucine-rich repeat architecture is emerging as an attractive framework for structural prediction and protein engineering. This review presents an update of the current understanding of leucine-rich repeat structure at the primary, secondary, tertiary and quaternary levels and discusses specific examples from recently determined three-dimensional structures.

  2. Integration of a Tick-Borne Encephalitis Virus and Borrelia burgdorferi sensu lato into Mountain Ecosystems, Following a Shift in the Altitudinal Limit of Distribution of Their Vector, Ixodes ricinus (Krkonoše Mountains, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Danielová, V.; Daniel, M.; Schwarzová, L.; Materna, J.; Rudenko, Natalia; Golovchenko, Maryna; Holubová, J.; Grubhoffer, Libor; Kilian, P.

    2010-01-01

    Roč. 10, č. 3 (2010), s. 223-230 ISSN 1530-3667 Grant - others:GA ČR(CZ) GA310/06/1546 Institutional research plan: CEZ:AV0Z60220518 Keywords : Borrelia burgdorferi genospecies * Climate * Ixodes ricinus tick * Mountain ecosystems * Tick-borne encephalitis virus Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.733, year: 2010

  3. Gene organization of a novel defensin of Ixodes ricinus: first annotation of an intron/exon structure in a hard tick defensin gene and first evidence of the occurrence of two isoforms of one member of the arthropod defensin family

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor

    2007-01-01

    Roč. 16, č. 4 (2007), s. 501-507 ISSN 0962-1075 R&D Projects: GA MŠk(CZ) LC06009; GA ČR(CZ) GA524/06/1479 Institutional research plan: CEZ:AV0Z60220518 Keywords : defensin * Ixodes ricinus * intron/exon structure * immune response * antimicrobial activity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.787, year: 2007

  4. Der-p2 (Dermatophagoides pteronyssinus) allergen-like protein from the hard tick Ixodes ricinus - a novel member of ML (MD-2-related lipid-recognition) domain protein family

    Czech Academy of Sciences Publication Activity Database

    Horáčková, Jana; Rudenko, Natalia; Golovchenko, Maryna; Grubhoffer, Libor

    2010-01-01

    Roč. 137, č. 7 (2010), s. 1139-1149 ISSN 0031-1820 R&D Projects: GA ČR(CZ) GA524/06/1479 Institutional research plan: CEZ:AV0Z60220518 Keywords : Der-p2 allergen-like protein * Ixodes ricinus * tick, * ML protein family * IgE-binding activity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.522, year: 2010

  5. Survey of ticks (Acari: Ixodidae) and tick-borne pathogens in North Dakota.

    Science.gov (United States)

    Russart, Nathan M; Dougherty, Michael W; Vaughan, Jefferson A

    2014-09-01

    Ticks were sampled at nine locations throughout North Dakota during early summer of 2010, using flagging techniques and small mammals trapping. In total, 1,762 ticks were collected from eight of the nine locations. The dominant species were Dermacentor variabilis (Say) (82%), found throughout the state, and Ixodes scapularis Say (17%), found in northeastern counties. A few nymphal and adult I. scapularis tested positive for Borrelia burgdorferi (3%) and Anaplasma phagocytophilum (8%). This is the first report of I. scapularis and associated pathogens occurring in North Dakota and provides evidence for continued westward expansion of this important vector tick species in the United States.

  6. Detection of Lyme Disease Bacterium, Borrelia burgdorferi sensu lato, in Blacklegged Ticks Collected in the Grand River Valley, Ontario, Canada

    Science.gov (United States)

    Scott, John D.; Foley, Janet E.; Anderson, John F.; Clark, Kerry L.; Durden, Lance A.

    2017-01-01

    We document the presence of blacklegged ticks, Ixodes scapularis, in the Grand River valley, Centre Wellington, Ontario. Overall, 15 (36%) of 42 I. scapularis adults collected from 41 mammalian hosts (dogs, cats, humans) were positive for the Lyme disease bacterium, Borrelia burgdorferi sensu lato (s.l.). Using real-time PCR testing and DNA sequencing of the flagellin (fla) gene, we determined that Borrelia amplicons extracted from I. scapularis adults belonged to B. burgdorferi sensu stricto (s.s.), which is pathogenic to humans and certain domestic animals. Based on the distribution of I. scapularis adults within the river basin, it appears likely that migratory birds provide an annual influx of I. scapularis immatures during northward spring migration. Health-care providers need to be aware that local residents can present with Lyme disease symptoms anytime during the year. PMID:28260991

  7. Repeatability & Workability Evaluation of SIGMOD 2009

    KAUST Repository

    Manegold, Stefan

    2010-12-15

    SIGMOD 2008 was the first database conference that offered to test submitters\\' programs against their data to verify the repeatability of the experiments published [1]. Given the positive feedback concerning the SIGMOD 2008 repeatability initiative, SIGMOD 2009 modified and expanded the initiative with a workability assessment.

  8. simple sequence repeats (EST-SSR)

    African Journals Online (AJOL)

    Yomi

    2012-01-19

    Jan 19, 2012 ... 212 primer pairs selected, based on repeat patterns of n≥8 for di-, tri-, tetra- and penta-nucleotide repeat ... Cluster analysis revealed a high genetic similarity among the sugarcane (Saccharum spp.) breeding lines which could reduce the genetic gain in ..... The multiple allele characteristic of SSR com-.

  9. Repeatability & Workability Evaluation of SIGMOD 2009

    KAUST Repository

    Manegold, Stefan; Manolescu, Ioana; Afanasiev, Loredana; Feng, Jieling; Gou, G.; Hadjieleftheriou, Marios; Harizopoulos, Stavros; Kalnis, Panos; Karanasos, Konstantinos; Laurent, Dominique; Lupu, M.; Onose, N.; Ré , C.; Sans, Virginie; Senellart, Pierre; Wu, T.; Shasha, Dennis E.

    2010-01-01

    SIGMOD 2008 was the first database conference that offered to test submitters' programs against their data to verify the repeatability of the experiments published [1]. Given the positive feedback concerning the SIGMOD 2008 repeatability initiative, SIGMOD 2009 modified and expanded the initiative with a workability assessment.

  10. UK 2009-2010 repeat station report

    Directory of Open Access Journals (Sweden)

    Thomas J.G. Shanahan

    2013-03-01

    Full Text Available The British Geological Survey is responsible for conducting the UK geomagnetic repeat station programme. Measurements made at the UK repeat station sites are used in conjunction with the three UK magnetic observatories: Hartland, Eskdalemuir and Lerwick, to produce a regional model of the local field each year. The UK network of repeat stations comprises 41 stations which are occupied at approximately 3-4 year intervals. Practices for conducting repeat station measurements continue to evolve as advances are made in survey instrumentation and as the usage of the data continues to change. Here, a summary of the 2009 and 2010 UK repeat station surveys is presented, highlighting the measurement process and techniques, density of network, reduction process and recent results.

  11. Contributions to the phylogeny of Ixodes (Pholeoixodes canisuga, I. (Ph. kaiseri, I. (Ph. hexagonus and a simple pictorial key for the identification of their females

    Directory of Open Access Journals (Sweden)

    Sándor Hornok

    2017-11-01

    Full Text Available Abstract Background In Europe, hard ticks of the subgenus Pholeoixodes (Ixodidae: Ixodes are usually associated with burrow-dwelling mammals and terrestrial birds. Reports of Pholeoixodes spp. from carnivores are frequently contradictory, and their identification is not based on key diagnostic characters. Therefore, the aims of the present study were to identify ticks collected from dogs, foxes and badgers in several European countries, and to reassess their systematic status with molecular analyses using two mitochondrial markers. Results Between 2003 and 2017, 144 Pholeoixodes spp. ticks were collected in nine European countries. From accurate descriptions and comparison with type-materials, a simple illustrated identification key was compiled for adult females, by focusing on the shape of the anterior surface of basis capituli. Based on this key, 71 female ticks were identified as I. canisuga, 21 as I. kaiseri and 21 as I. hexagonus. DNA was extracted from these 113 female ticks, and from further 31 specimens. Fragments of two mitochondrial genes, cox1 (cytochrome c oxidase subunit 1 and 16S rRNA, were amplified and sequenced. Ixodes kaiseri had nine unique cox1 haplotypes, which showed 99.2–100% sequence identity, whereas I. canisuga and I. hexagonus had eleven and five cox1 haplotypes, respectively, with 99.5–100% sequence identity. The distribution of cox1 haplotypes reflected a geographical pattern. Pholeoixodes spp. ticks had fewer 16S rRNA haplotypes, with a lower degree of intraspecific divergence (99.5–100% sequence identity and no geographical clustering. Phylogenetic analyses were in agreement with morphology: I. kaiseri and I. hexagonus (with the similar shape of the anterior surface of basis capituli were genetically more closely related to each other than to I. canisuga. Phylogenetic analyses also showed that the subgenus Eschatocephalus (bat ticks clustered within the subgenus Pholeoixodes. Conclusions A simple

  12. The Tick Salivary Protein Salp15 Inhibits the Killing of Serum-Sensitive Borrelia burgdorferi Sensu Lato Isolates▿

    OpenAIRE

    Schuijt, Tim J.; Hovius, Joppe W. R.; van Burgel, Nathalie D.; Ramamoorthi, Nandhini; Fikrig, Erol; van Dam, Alje P.

    2008-01-01

    Borrelia burgdorferi, the agent of Lyme disease, is transmitted by ticks. During transmission from the tick to the host, spirochetes are delivered with tick saliva, which contains the salivary protein Salp15. Salp15 has been shown to protect spirochetes against B. burgdorferi-specific antibodies. We now show that Salp15 from both Ixodes ricinus and Ixodes scapularis protects serum-sensitive isolates of Borrelia burgdorferi sensu lato against complement-mediated killing. I. ricinus Salp15 show...

  13. Soluble cysteine-rich tick saliva proteins Salp15 and Iric-1 from E. coli

    OpenAIRE

    Kolb, Philipp; Vorreiter, Jolanta; Habicht, J?ri; Bentrop, Detlef; Wallich, Reinhard; Nassal, Michael

    2014-01-01

    Ticks transmit numerous pathogens, including borreliae, which cause Lyme disease. Tick saliva contains a complex mix of anti-host defense factors, including the immunosuppressive cysteine-rich secretory glycoprotein Salp15 from Ixodes scapularis ticks and orthologs like Iric-1 from Ixodes ricinus. All tick-borne microbes benefit from the immunosuppression at the tick bite site; in addition, borreliae exploit the binding of Salp15 to their outer surface protein C (OspC) for enhanced transmissi...

  14. A Novel Scoring System Approach to Assess Patients with Lyme Disease (Nutech Functional Score)

    OpenAIRE

    Geeta Shroff; Petra Hopf-Seidel

    2018-01-01

    Introduction: A bacterial infection by Borrelia burgdorferi referred to as Lyme disease (LD) or borreliosis is transmitted mostly by a bite of the tick Ixodes scapularis in the USA and Ixodes ricinus in Europe. Various tests are used for the diagnosis of LD, but their results are often unreliable. We compiled a list of clinically visible and patient-reported symptoms that are associated with LD. Based on this list, we developed a novel scoring system. Methodology: Nutech functional Score (NF...

  15. Development of analog watch with minute repeater

    Science.gov (United States)

    Okigami, Tomio; Aoyama, Shigeru; Osa, Takashi; Igarashi, Kiyotaka; Ikegami, Tomomi

    A complementary metal oxide semiconductor with large scale integration was developed for an electronic minute repeater. It is equipped with the synthetic struck sound circuit to generate natural struck sound necessary for the minute repeater. This circuit consists of an envelope curve drawing circuit, frequency mixer, polyphonic mixer, and booster circuit made by using analog circuit technology. This large scale integration is a single chip microcomputer with motor drivers and input ports in addition to the synthetic struck sound circuit, and it is possible to make an electronic system of minute repeater at a very low cost in comparison with the conventional type.

  16. Preventing Repeat Teen Births PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second public service announcement is based on the April 2013 CDC Vital Signs report, which discusses repeat teen births and ways teens, parents and guardians, health care providers, and communities can help prevent them.

  17. Molecular Survey on Rickettsia spp., Anaplasma phagocytophilum, Borrelia burgdorferi Sensu Lato, and Babesia spp. in Ixodes ricinus Ticks Infesting Dogs in Central Italy.

    Science.gov (United States)

    Morganti, Giulia; Gavaudan, Stefano; Canonico, Cristina; Ravagnan, Silvia; Olivieri, Emanuela; Diaferia, Manuela; Marenzoni, Maria Luisa; Antognoni, Maria Teresa; Capelli, Gioia; Silaghi, Cornelia; Veronesi, Fabrizia

    2017-11-01

    Dogs are a common feeding hosts for Ixodes ricinus and may act as reservoir hosts for zoonotic tick-borne pathogens (TBPs) and as carriers of infected ticks into human settings. The aim of this work was to evaluate the presence of several selected TBPs of significant public health concern by molecular methods in I. ricinus recovered from dogs living in urban and suburban settings in central Italy. A total of 212 I. ricinus specimens were collected from the coat of domestic dogs. DNA was extracted from each specimen individually and tested for Rickettsia spp., Borrelia burgdorferi sensu lato, Babesia spp., and Anaplasma phagocytophilum, using real-time and conventional PCR protocols, followed by sequencing. Sixty-one ticks (28.8%) tested positive for TBPs; 57 samples were infected by one pathogen, while four showed coinfections. Rickettsia spp. was detected in 39 specimens (18.4%), of which 32 were identified as Rickettsia monacensis and seven as Rickettsia helvetica. Twenty-two samples (10.4%) tested positive for A. phagocytophilum; Borrelia lusitaniae and Borrelia afzelii were detected in two specimens and one specimen, respectively. One tick (0.5%) was found to be positive for Babesia venatorum (EU1). Our findings reveal the significant exposure of dogs to TBPs of public health concern and provide data on the role of dogs in the circulation of I. ricinus-borne pathogens in central Italy.

  18. First evidence of [i]Babesia venatorum[/i] and [i]Babesia capreoli[/i] in questing Ixodes ricinus ticks in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Kristyna Venclikova

    2015-05-01

    Full Text Available Introduction and objective. [i]Ixodes ricinus[/i] is the most common tick species occurring in Central Europe and it serves as a principal vector of emerging human pathogens. The aim of this study was to determine the prevalence of [i]Babesia spp[/i]. in host-seeking [i]I. ricinus[/i] in urban and natural habitats. Materials and methods. PCR was applied on samples to assess prevalence of [i]Babesia spp.[/i] in questing ixodid ticks. Sequencing was used for [i]Babesia[/i] species determination. Results. 1,473 [i]I. ricinus[/i] ticks (1,294 nymphs, 99 males and 80 females were examined for the presence of [i]Babesia spp[/i]. at the two study sites. Minimum infection rate for [i]Babesia[/i] spp. was found to be 0.5% (infected I. ricinus nymphs were only detected in the natural ecosystem. Two[i] Babesia[/i] species were identified by sequencing: [i]B. venatorum[/i] (formerly called[i] Babesia[/i] sp. EU1 and [i]B. capreoli. [/i] Conclusions. The results obtained represent the first evidence of the occurrence of [i]B. venatorum[/i] and [i]B. capreoli[/i] in host-seeking[i] I. ricinus[/i] ticks in the Czech Republic.

  19. Digital repeat analysis; setup and operation.

    Science.gov (United States)

    Nol, J; Isouard, G; Mirecki, J

    2006-06-01

    Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors.

  20. Automated genotyping of dinucleotide repeat markers

    Energy Technology Data Exchange (ETDEWEB)

    Perlin, M.W.; Hoffman, E.P. [Carnegie Mellon Univ., Pittsburgh, PA (United States)]|[Univ. of Pittsburgh, PA (United States)

    1994-09-01

    The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

  1. Role of memory errors in quantum repeaters

    International Nuclear Information System (INIS)

    Hartmann, L.; Kraus, B.; Briegel, H.-J.; Duer, W.

    2007-01-01

    We investigate the influence of memory errors in the quantum repeater scheme for long-range quantum communication. We show that the communication distance is limited in standard operation mode due to memory errors resulting from unavoidable waiting times for classical signals. We show how to overcome these limitations by (i) improving local memory and (ii) introducing two operational modes of the quantum repeater. In both operational modes, the repeater is run blindly, i.e., without waiting for classical signals to arrive. In the first scheme, entanglement purification protocols based on one-way classical communication are used allowing to communicate over arbitrary distances. However, the error thresholds for noise in local control operations are very stringent. The second scheme makes use of entanglement purification protocols with two-way classical communication and inherits the favorable error thresholds of the repeater run in standard mode. One can increase the possible communication distance by an order of magnitude with reasonable overhead in physical resources. We outline the architecture of a quantum repeater that can possibly ensure intercontinental quantum communication

  2. Safety of Repeated Yttrium-90 Radioembolization

    International Nuclear Information System (INIS)

    Lam, Marnix G. E. H.; Louie, John D.; Iagaru, Andrei H.; Goris, Michael L.; Sze, Daniel Y.

    2013-01-01

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver’s cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51–71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction

  3. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    International Nuclear Information System (INIS)

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-01-01

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80–90). The mean retreatment dose was 84.4 Gy (range, 60–90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  4. Safety of Repeated Yttrium-90 Radioembolization

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Marnix G. E. H.; Louie, John D. [Stanford University School of Medicine, Division of Interventional Radiology (United States); Iagaru, Andrei H.; Goris, Michael L. [Stanford University School of Medicine, Division of Nuclear Medicine (United States); Sze, Daniel Y., E-mail: dansze@stanford.edu [Stanford University School of Medicine, Division of Interventional Radiology (United States)

    2013-10-15

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

  5. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    Energy Technology Data Exchange (ETDEWEB)

    Aubuchon, Adam C., E-mail: acaubuchon@gmail.com [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Chan, Michael D. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Lovato, James F. [Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC (United States); Balamucki, Christopher J. [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ellis, Thomas L.; Tatter, Stephen B. [Department of Neurosurgery, Wake Forest University School of Medicine, Winston-Salem, NC (United States); McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G. [Department of Radiation Oncology, Wake Forest University School of Medicine, Winston-Salem, NC (United States)

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  6. Repeating pneumatic pellet injector in JAERI

    International Nuclear Information System (INIS)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi; Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author)

  7. Repeating pneumatic pellet injector in JAERI

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Satoshi; Hasegawa, Kouichi; Suzuki, Sadaaki; Miura, Yukitoshi (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment); Oda, Yasushi; Onozuka, Masanori; Tsujimura, Seiichi.

    1992-09-01

    A repeating pneumatic pellet injector has been developed and constructed at Japan Atomic Energy Research Institute. This injector can provide repetitive pellet injection to fuel tokamak plasmas for an extended period of time, aiming at the improvement of plasma performance. The pellets with nearly identical speed and mass can be repeatedly injected with a repetition rate of 2-3.3 Hz and a speed of up to 1.7 km/s by controlling the temperature of the cryogenic system, the piston speed and the pressure of the propellant gas. (author).

  8. Molecular biology of tick Acetylcholinesterases – a minireview

    Science.gov (United States)

    Ticks are important hematophagous arthropod ectoparasites and like mosquitoes, are vectors for a wide variety of human and animal pathogens. Ticks have significant world-wide health and economic impacts. In the U.S., major impacts include the ability of the blacklegged tick, Ixodes scapularis, to tr...

  9. Detection of Borrelia burgdorferi sensu stricto in Amblyomma americanum ticks in the southeastern United States: the case of selective compatibility

    Czech Academy of Sciences Publication Activity Database

    Rudenko, Natalia; Golovchenko, Maryna; Clark, K.; Oliver, J.; Grubhoffer, Libor

    2016-01-01

    Roč. 5, MAY 25 (2016), č. článku e48. ISSN 2222-1751 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : lyme disease spirochete * Dermacentor variabilis * Ixodes scapularis * Ixodidae * Acari * strain Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 5.605, year: 2016

  10. EST Table: DC572689 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available DC572689 E_FL_wd--_27G20_R_0 10/09/28 53 %/126 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

  11. EST Table: DC572641 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available DC572641 E_FL_wd--_27E09_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

  12. EST Table: DC563666 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available DC563666 E_FL_wd--_01A16_R_0 10/09/28 53 %/141 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

  13. EST Table: DC566703 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available DC566703 E_FL_wd--_09O22_R_0 10/09/28 52 %/145 aa ref|XP_002400269.1| DNA mismatch repair protein mlh1..., putative [Ixodes scapularis] gb|EEC09245.1| DNA mismatch repair protein mlh1, putative

  14. Remodeling of tick cytoskeleton in response to infection with Anaplasma phagocytophilum

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; Alberdi, P.; Valdés, James J.; Villar, M.; de la Fuente, J.

    2017-01-01

    Roč. 22, Jun 1 (2017), s. 1830-1844 ISSN 1093-4715 EU Projects: European Commission(XE) 278976 - ANTIGONE Institutional support: RVO:60077344 Keywords : cytoskeleton * proteomics * transcriptomics * Ixodes scapularis * Anaplasma phagocytophilum Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology

  15. A formulation to encapusulate nootkatone oil for tick control

    Science.gov (United States)

    Nootkatone is a component of grapefruit oil that is toxic to the disease vectoring tick, Ixodes scapularis Say, but unfortunately causes phytotoxicity to treated plants and has a short residual activity due to volatility. We prepared an encapsulated formulation of nootkatone using lignin to compare...

  16. Climate of origin affects tick (Ixodes ricinus) host-seeking behavior in response to temperature: implications for resilience to climate change?

    Science.gov (United States)

    Gilbert, Lucy; Aungier, Jennifer; Tomkins, Joseph L

    2014-04-01

    Climate warming is changing distributions and phenologies of many organisms and may also impact on vectors of disease-causing pathogens. In Europe, the tick Ixodes ricinus is the primary vector of medically important pathogens (e.g., Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis). How might climate change affect I. ricinus host-seeking behavior (questing)? We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. We predicted that ticks from cooler climates quest at cooler temperatures than those from warmer climates. This would suggest that I. ricinus can adapt and therefore have the potential to be resilient to climate change. I. ricinus were collected from a cline of climates using a latitudinal gradient (northeast Scotland, North Wales, South England, and central France). Under laboratory conditions, ticks were subjected to temperature increases of 1°C per day, from 6 to 15°C. The proportion of ticks questing was recorded five times per temperature (i.e., per day). The theoretical potential to quest was then estimated for each population over the year for future climate change projections. As predicted, more ticks from cooler climates quested at lower temperatures than did ticks from warmer climates. The proportion of ticks questing was strongly associated with key climate parameters from each location. Our projections, based on temperature alone, suggested that populations could advance their activity season by a month under climate change, which has implications for exposure periods of hosts to tick-borne pathogens. Our findings suggest that I. ricinus have adapted their behavior in response to climate, implying some potential to adapt to climate change. Predictive models of I. ricinus dynamics and disease risk over continental scales would benefit from knowledge of these differences between populations.

  17. Profiling of proteolytic enzymes in the gut of the tick Ixodes ricinus reveals an evolutionarily conserved network of aspartic and cysteine peptidases

    Directory of Open Access Journals (Sweden)

    Mareš Michael

    2008-03-01

    Full Text Available Abstract Background Ticks are vectors for a variety of viral, bacterial and parasitic diseases in human and domestic animals. To survive and reproduce ticks feed on host blood, yet our understanding of the intestinal proteolytic machinery used to derive absorbable nutrients from the blood meal is poor. Intestinal digestive processes are limiting factors for pathogen transmission since the tick gut presents the primary site of infection. Moreover, digestive enzymes may find practical application as anti-tick vaccine targets. Results Using the hard tick, Ixodes ricinus, we performed a functional activity scan of the peptidase complement in gut tissue extracts that demonstrated the presence of five types of peptidases of the cysteine and aspartic classes. We followed up with genetic screens of gut-derived cDNA to identify and clone genes encoding the cysteine peptidases cathepsins B, L and C, an asparaginyl endopeptidase (legumain, and the aspartic peptidase, cathepsin D. By RT-PCR, expression of asparaginyl endopeptidase and cathepsins B and D was restricted to gut tissue and to those developmental stages feeding on blood. Conclusion Overall, our results demonstrate the presence of a network of cysteine and aspartic peptidases that conceivably operates to digest host blood proteins in a concerted manner. Significantly, the peptidase components of this digestive network are orthologous to those described in other parasites, including nematodes and flatworms. Accordingly, the present data and those available for other tick species support the notion of an evolutionary conservation of a cysteine/aspartic peptidase system for digestion that includes ticks, but differs from that of insects relying on serine peptidases.

  18. Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests.

    Directory of Open Access Journals (Sweden)

    Ralf Lauterbach

    Full Text Available Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008-2010 in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming.

  19. Identification of host blood-meal sources and Borrelia in field-collected Ixodes ricinus ticks in north-western Poland

    Directory of Open Access Journals (Sweden)

    Beata Wodecka

    2015-12-01

    Full Text Available Forest animals play fundamental roles in the maintenance of [i]Ixodes ricinus[/i] and [i]Borrelia[/i] species in the forest biotope. To identify the forest vertebrate species that are host for I. ricinus and for the recognition of the reservoirs of [i]Borrelia[/i] species, the blood-meal of 325 [i]I. ricinus[/i] ticks collected at two forest sites in north-western Poland were analysed. Nested PCR was used to detect polymorphisms in a fragment of the mitochondrial 12S rRNA gene for the identification of the hosts species. The products were digested with the restriction enzymes, a combination that allows the identification of 60 vertebrate species, comprising 17 bird, 4 reptile and 39 mammalian species. Host DNA was detected in 244 (75%[i] I. ricinus[/i] individuals, with the species being detected and classified for 210 (86% samples. The restriction patterns resulted in the identification of 14 vertebrate species, including 2 species of birds, lizard, badger, rabbit, deer; most of the samples contained DNA from wild boar ([i]Sus scrofa[/i], red fox ([i]Vulpes vulpes[/i], red deer ([i]Cervus elaphus[/i] and roe deer ([i]Capreolus capreolus[/i]. Identification of Borrelia species was based on the flaB gene using nested PCR coupled to RFLP. This method allows the identification of all [i]Borrelia[/i] species transmitted by [i]I. ricinus [/i]in Europe, including [i]B. miyamotoi[/i] and 3 genetic variants of [i]B. garinii[/i]. In the studied isolates, 2 species belonging to [i]B. burgdorferi[/i] sensu lato were identified – B. [i]garinii [/i]and B. [i]afzelii[/i], and B. [i]miyamotoi,[/i] which are related to relapsing fever borreliae.

  20. Detection of Rickettsia helvetica in Ixodes ricinus infesting wild and domestic animals and in a botfly larva (Cephenemyia stimulator) infesting roe deer in Germany.

    Science.gov (United States)

    Scheid, Patrick; Speck, Stephanie; Schwarzenberger, Rafael; Litzinger, Mark; Balczun, Carsten; Dobler, Gerhard

    2016-10-01

    Ixodes ricinus is a well-known vector of different human pathogens including Rickettsia helvetica. The role of wild mammals in the distribution and probable maintenance of Rickettsia in nature is still to be determined. We therefore investigated various parasites from different wild mammals as well as companion animals for the presence of Rickettsia. A total of 606 I. ricinus, 38 Cephenemyia stimulator (botfly larvae), one Dermacentor reticulatus, 24 Haematopinus suis (hog lice) and 30 Lipoptena cervi (deer flies) were collected from free-ranging animals during seasonal hunting, and from companion animals. Sample sites included hunting leases at three main sampling areas and five additional areas in West and Central Germany. All collected parasites were screened for Rickettsia spp. and I. ricinus were investigated for tick-borne encephalitis virus (TBEV) in addition. While no TBEV was detected, the minimum infection rate (MIR) of I. ricinus with Rickettsia was 4.1% referring to all sampling sites and up to 6.9% at the main sampling site in Koblenz area. Sequencing of a fragment of the ompB gene identified R. helvetica. Approximately one third (29.5%) of the animals carried Rickettsia-positive ticks and the MIR in ticks infesting wild mammals ranged from 4.1% (roe deer) to 9.5%. These data affirm the widespread distribution of R. helvetica in Germany. One botfly larva from roe deer also harboured R. helvetica. Botfly larvae are obligate parasites of the nasal cavity, pharynx and throat of cervids and feed on cell fragments and blood. Based on this one might hypothesise that R. helvetica likely induces rickettsemia in cervids thus possibly contributing to maintenance and distribution of this rickettsia in the field. Copyright © 2016 Elsevier GmbH. All rights reserved.

  1. Prevalence of infection with Rickettsia helvetica in Ixodes ricinus ticks feeding on non-rickettsiemic rodent hosts in sylvatic habitats of west-central Poland.

    Science.gov (United States)

    Biernat, Beata; Stańczak, Joanna; Michalik, Jerzy; Sikora, Bożena; Wierzbicka, Anna

    2016-02-01

    Ixodes ricinus is the most prevalent and widely distributed tick species in European countries and plays a principal role in transmission of a wide range of microbial pathogens. It is also a main vector and reservoir of Rickettsia spp. of the spotted fever group with the infection level ranging in Poland from 1.3% to 11.4%. Nevertheless, little research has been conducted so far to identify reservoir hosts for these pathogens. A survey was undertaken to investigate the presence of Rickettsia spp. in wild small rodents and detached I. ricinus. Rodents, Apodemus flavicollis mice and Myodes glareolus voles were captured in typically sylvatic habitats of west-central Poland. Blood samples and collected ticks were analyzed by conventional, semi-nested and nested PCRs. Rickettsial species were determined by sequence analysis of obtained fragments of gltA and 16S rRNA genes. A total of 2339 immature I. ricinus (mostly larvae) were collected from 158 animals. Proportion of hosts carrying ticks was 84%, being higher for A. flavicollis than for M. glareolus. Rickettsia helvetica, the only species identified, was detected in 8% of 12 nymphs and in at least 10.7% (MIR) of 804 larvae investigated. Prevalence of infected ticks on both rodent species was comparable (10.8 vs. 9%). None of blood samples tested was positive for Rickettsia spp. The results showed that in sylvatic habitats the level of infestation with larval I. ricinus was higher in A. flavicollis mice in comparison with M. glareolus voles. They show that R. helvetica frequently occurred in ticks feeding on rodents. Positive immature ticks were collected from non-rickettsiemic hosts what might suggest a vertical route of their infection (transovarial and/or transstadial) or a very short-lasting rickettsiemia in rodents. A natural vertebrate reservoir host for R. helvetica remains to be determined. Copyright © 2015 Elsevier GmbH. All rights reserved.

  2. Molecular analysis of Ixodes rugicollis, Candidatus Neoehrlichia sp. (FU98) and a novel Babesia genotype from a European badger (Meles meles).

    Science.gov (United States)

    Hornok, Sándor; Trauttwein, Klaudia; Takács, Nóra; Hodžić, Adnan; Duscher, Georg Gerhard; Kontschán, Jenő

    2017-01-01

    The European badger (Meles meles) is a widespread mammal in most countries of the European continent, with increasingly recognized veterinary/medical importance owing to its preferred habitats (including pastures and urban environments), broad spectrum of food items, and role as a game hunting target. However, ticks and tick-borne pathogens associated with badgers are only partly known, and most of them have not yet been analysed with molecular biological methods The aim of this study was to perform molecular taxonomic analysis of ticks collected from a road-killed European badger, as well as to molecularly investigate its ticks and blood sample for the presence of Anaplasmataceae and piroplasms. Ticks from the badger were morphologically identified as females of Ixodes rugicollis. Based on its cytochrome oxidase subunit I (COI) and 16S rRNA sequences, I. rugicollis phylogenetically clustered together with I. lividus and I. arboricola, i.e. other members of the subgenus Pholeoixodes. The blood sample of the badger contained the DNA of Candidatus Neoehrlichia sp. (FU98) recently identified in red fox in Austria and the Czech Republic. This genotype is most closely related to Ca. N. lotoris (from raccoons in North America), and has lower sequence identity with the I. ricinus-transmitted zoonotic agent, Ca. N. mikurensis found in Eurasia. In the blood of the badger and in one female I. rugicollis, the DNA of a new Babesia genotype was also present, which differed from a piroplasm detected in M. meles in Spain, and clustered phylogenetically in the B. microti clade. Phylogenetic analysis of I. rugicollis (based on two genetic markers) confirms its status in subgenus Pholeoixodes. Ca. Neoehrlichia sp. (FU98) was identified for the first time in M. meles and in Hungary. In addition, a molecularly previously not yet characterized Babesia genotype occurs in badgers in Central Europe. Copyright © 2016 Elsevier GmbH. All rights reserved.

  3. The impact of climate change on the expansion of Ixodes persulcatus habitat and the incidence of tick-borne encephalitis in the north of European Russia

    Science.gov (United States)

    Tokarevich, Nikolay K.; Tronin, Andrey A.; Blinova, Olga V.; Buzinov, Roman V.; Boltenkov, Vitaliy P.; Yurasova, Elena D.; Nurse, Jo

    2011-01-01

    Background The increase in tick-borne encephalitis (TBE) incidence is observed in recent decades in a number of subarctic countries. The reasons of it are widely discussed in scientific publications. The objective of this study was to understand if the climate change in Arkhangelsk Oblast (AO) situated in the north of European subarctic zone of Russia has real impact on the northward expansion of Ixodid ticks and stipulates the increase in TBE incidence. Methods This study analyzes: TBE incidence in AO and throughout Russia, the results of Ixodid ticks collecting in a number of sites in AO, and TBE virus prevalence in those ticks, the data on tick bite incidence in AO, and meteorological data on AO mean annual air temperatures and precipitations. Results It is established that in recent years TBE incidence in AO tended to increase contrary to its apparent decrease nationwide. In last 10 years, there was nearly 50-fold rise in TBE incidence in AO when compared with 1980–1989. Probably, the increase both in mean annual air temperatures and temperatures during tick active season resulted in the northward expansion of Ixodes Persulcatus, main TBE virus vector. The Ixodid ticks expansion is confirmed both by the results of ticks flagging from the surface vegetation and by the tick bite incidence in the population of AO locations earlier free from ticks. Our mathematical (correlation and regression) analysis of available data revealed a distinct correlation between TBE incidence and the growth of mean annual air temperatures in AO in 1990–2009. Conclusion Not ruling out other factors, we conclude that climate change contributed much to the TBE incidence increase in AO. PMID:22028678

  4. Repeating and non-repeating fast radio bursts from binary neutron star mergers

    Science.gov (United States)

    Yamasaki, Shotaro; Totani, Tomonori; Kiuchi, Kenta

    2018-04-01

    Most fast radio bursts (FRB) do not show evidence of repetition, and such non-repeating FRBs may be produced at the time of a merger of binary neutron stars (BNS), provided that the BNS merger rate is close to the high end of the currently possible range. However, the merger environment is polluted by dynamical ejecta, which may prohibit the radio signal from propagating. We examine this by using a general-relativistic simulation of a BNS merger, and show that the ejecta appears about 1 ms after the rotation speed of the merged star becomes the maximum. Therefore there is a time window in which an FRB signal can reach outside, and the short duration of non-repeating FRBs can be explained by screening after ejecta formation. A fraction of BNS mergers may leave a rapidly rotating and stable neutron star, and such objects may be the origin of repeating FRBs like FRB 121102. We show that a merger remnant would appear as a repeating FRB on a time scale of ˜1-10 yr, and expected properties are consistent with the observations of FRB 121102. We construct an FRB rate evolution model that includes these two populations of repeating and non-repeating FRBs from BNS mergers, and show that the detection rate of repeating FRBs relative to non-repeating ones rapidly increases with improving search sensitivity. This may explain why only the repeating FRB 121102 was discovered by the most sensitive FRB search with Arecibo. Several predictions are made, including the appearance of a repeating FRB 1-10 yr after a BNS merger that is localized by gravitational waves and subsequent electromagnetic radiation.

  5. Ecological Panel Inference from Repeated Cross Sections

    NARCIS (Netherlands)

    Pelzer, Ben; Eisinga, Rob; Franses, Philip Hans

    2004-01-01

    This chapter presents a Markov chain model for the estimation of individual-level binary transitions from a time series of independent repeated cross-sectional (RCS) samples. Although RCS samples lack direct information on individual turnover, it is demonstrated here that it is possible with these

  6. Preventing Repeat Teen Births PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2013-04-02

    This 60 second public service announcement is based on the April 2013 CDC Vital Signs report, which discusses repeat teen births and ways teens, parents and guardians, health care providers, and communities can help prevent them.  Created: 4/2/2013 by Centers for Disease Control and Prevention (CDC).   Date Released: 4/2/2013.

  7. Costly renegotiation in repeated Bertand games

    DEFF Research Database (Denmark)

    Andersson, Ola; Wengström, Erik Roland

    2010-01-01

    This paper extends the concept of weak renegotiation-proof equilibrium (WRP) to allow for costly renegotiation and shows that even small renegotiation costs can have dramatic effects on the set of equilibria. More specifically, the paper analyzes the infinitely repeated Bertrand game. It is shown...

  8. On Solving Intransitivities in Repeated Pairwise Choices

    NARCIS (Netherlands)

    A. Maas (Arne); Th.G.G. Bezembinder (Thom); P.P. Wakker (Peter)

    1995-01-01

    textabstractAn operational method is presented for deriving a linear ranking of alternatives from repeated paired comparisons of the alternatives. Intransitivities in the observed preferences are cleared away by the introduction of decision errors of varying importance. An observed preference

  9. Repeated checking induces uncertainty about future threat

    NARCIS (Netherlands)

    Giele, C.L.|info:eu-repo/dai/nl/318754460; Engelhard, I.M.|info:eu-repo/dai/nl/239681533; van den Hout, M.A.|info:eu-repo/dai/nl/070445354; Dek, E.C.P.|info:eu-repo/dai/nl/313959552; Damstra, Marianne; Douma, Ellen

    2015-01-01

    Studies have shown that obsessive-compulsive (OC) -like repeated checking paradoxically increases memory uncertainty. This study tested if checking also induces uncertainty about future threat by impairing the distinction between danger and safety cues. Participants (n = 54) engaged in a simulated

  10. FRB 121102: A Starquake-induced Repeater?

    Science.gov (United States)

    Wang, Weiyang; Luo, Rui; Yue, Han; Chen, Xuelei; Lee, Kejia; Xu, Renxin

    2018-01-01

    Since its initial discovery, the fast radio burst (FRB) FRB 121102 has been found to be repeating with millisecond-duration pulses. Very recently, 14 new bursts were detected by the Green Bank Telescope during its continuous monitoring observations. In this paper, we show that the burst energy distribution has a power-law form which is very similar to the Gutenberg–Richter law of earthquakes. In addition, the distribution of burst waiting time can be described as a Poissonian or Gaussian distribution, which is consistent with earthquakes, while the aftershock sequence exhibits some local correlations. These findings suggest that the repeating FRB pulses may originate from the starquakes of a pulsar. Noting that the soft gamma-ray repeaters (SGRs) also exhibit such distributions, the FRB could be powered by some starquake mechanisms associated with the SGRs, including the crustal activity of a magnetar or solidification-induced stress of a newborn strangeon star. These conjectures could be tested with more repeating samples.

  11. On balanced minimal repeated measurements designs

    Directory of Open Access Journals (Sweden)

    Shakeel Ahmad Mir

    2014-10-01

    Full Text Available Repeated Measurements designs are concerned with scientific experiments in which each experimental unit is assigned more than once to a treatment either different or identical. This class of designs has the property that the unbiased estimators for elementary contrasts among direct and residual effects are obtainable. Afsarinejad (1983 provided a method of constructing balanced Minimal Repeated Measurements designs p < t , when t is an odd or prime power, one or more than one treatment may occur more than once in some sequences and  designs so constructed no longer remain uniform in periods. In this paper an attempt has been made to provide a new method to overcome this drawback. Specifically, two cases have been considered                RM[t,n=t(t-t/(p-1,p], λ2=1 for balanced minimal repeated measurements designs and  RM[t,n=2t(t-t/(p-1,p], λ2=2 for balanced  repeated measurements designs. In addition , a method has been provided for constructing              extra-balanced minimal designs for special case RM[t,n=t2/(p-1,p], λ2=1.

  12. Repeater For A Digital-Communication Bus

    Science.gov (United States)

    Torres-Guzman, Esteban; Olson, Stephen; Heaps, Tim

    1993-01-01

    Digital repeater circuit designed to extend range of communication on MIL-STD-1553 bus beyond original maximum allowable length of 300 ft. Circuit provides two-way communication, one way at time, and conforms to specifications of MIL-STD-1553. Crosstalk and instability eliminated.

  13. The paralogous salivary anti-complement proteins IRAC I and IRAC II encoded by Ixodes ricinus ticks have broad and complementary inhibitory activities against the complement of different host species.

    Science.gov (United States)

    Schroeder, Hélène; Daix, Virginie; Gillet, Laurent; Renauld, Jean-Christophe; Vanderplasschen, Alain

    2007-02-01

    Several observations suggest that inhibition of the host complement alternative pathway by Ixodes tick saliva is crucial to achieve blood feeding. We recently described two paralogous anti-complement proteins called Ixodes ricinus anti-complement (IRAC) proteins I and II co-expressed in I. ricinus salivary glands. Phylogenetic analyses suggested that these sequences were diversifying by a process of positive Darwinian selection, possibly leading to molecules with different biological properties. In the present study, we tested the hypothesis that each paralogue may have different inhibitory activities against the complement of different natural host species, thereby contributing to broaden the host range of I. ricinus ticks. IRAC I and IRAC II were tested against the complement of eight I. ricinus natural host species (six mammals and two birds). The results demonstrate that IRAC I and IRAC II have broad and complementary inhibition activities against the complement of different host species. This report is the first description of paralogous anti-complement molecules encoded by a pathogen with broad and complementary inhibitory activities against the complement of different host species.

  14. Overcoming fixation with repeated memory suppression.

    Science.gov (United States)

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  15. Deception and Retribution in Repeated Ultimatum Bargaining.

    Science.gov (United States)

    Boles; Croson; Murnighan

    2000-11-01

    This paper investigates the dynamics of deception and retribution in repeated ultimatum bargaining. Anonymous dyads exchanged messages and offers in a series of four ultimatum bargaining games that had prospects for relatively large monetary outcomes. Variations in each party's knowledge of the other's resources and alternatives created opportunities for deception. Revelation of prior unknowns exposed deceptions and created opportunities for retribution in subsequent interactions. Results showed that although proposers and responders chose deceptive strategies almost equally, proposers told more outright lies. Both were more deceptive when their private information was never revealed, and proposers were most deceptive when their potential profits were largest. Revelation of proposers' lies had little effect on their subsequent behavior even though responders rejected their offers more than similar offers from truthful proposers or proposers whose prior deceit was never revealed. The discussion and conclusions address the dynamics of deception and retribution in repeated bargaining interactions. Copyright 2000 Academic Press.

  16. Learning With Repeated-Game Strategies

    Directory of Open Access Journals (Sweden)

    Christos A. Ioannou

    2014-07-01

    Full Text Available We use the self-tuning Experience Weighted Attraction model with repeated-game strategies as a computer testbed to examine the relative frequency, speed of convergence and progression of a set of repeated-game strategies in four symmetric 2x2 games: Prisoner's Dilemma, Battle of the Sexes, Stag-Hunt, and Chicken. In the Prisoner's Dilemma game, we fi□nd that the strategy with the most occurrences is the Grim-Trigger. In the Battle of the Sexes game, a cooperative pair that alternates between the two pure-strategy Nash equilibria emerges as the one with the most occurrences. In the Stag-Hunt and Chicken games, the Win-Stay, Lose-Shift and Grim-Trigger strategies are the ones with the most occurrences. Overall, the pairs that converged quickly ended up at the cooperative outcomes, whereas the ones that were extremely slow to reach convergence ended up at non-cooperative outcomes.

  17. Governing conditions of repeatable Barkhausen noise response

    International Nuclear Information System (INIS)

    Stupakov, O.; Pal'a, J.; Takagi, T.; Uchimoto, T.

    2009-01-01

    The paper is devoted to the establishment of experimental conditions, which ensure the repeatability of magnetic Barkhausen noise testing in practice. For this task, the measurements were performed on open flat samples using different experimental configurations, including: different magnetization frequencies, sampling rates, and filter cut-off frequencies; using a sample-wrapped coil and using attached pick-up coils of various dimensions, with different lift-offs of a single yoke magnet and of the attached coil. The sample magnetization was controlled by a vertical array of three Hall sensors; their readings were extrapolated to the sample surface to precisely define its field. After analysis of the results, a scheme for an optimized sensor with a controlled field waveform was suggested to improve the measurement repeatability. The important issues of signal processing and parameter applicability were also discussed in detail.

  18. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.

    2009-05-20

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements. We allow for a working covariance matrix for the regression errors, showing that our method is most efficient when the correct covariance matrix is used. The component functions achieve the known asymptotic variance lower bound for the scalar argument case. Smooth backfitting also leads directly to design-independent biases in the local linear case. Simulations show our estimator has smaller variance than the usual kernel estimator. This is also illustrated by an example from nutritional epidemiology. © 2009 Biometrika Trust.

  19. Repeated interactions in open quantum systems

    Energy Technology Data Exchange (ETDEWEB)

    Bruneau, Laurent, E-mail: laurent.bruneau@u-cergy.fr [Laboratoire AGM, Université de Cergy-Pontoise, Site Saint-Martin, BP 222, 95302 Cergy-Pontoise (France); Joye, Alain, E-mail: Alain.Joye@ujf-grenoble.fr [Institut Fourier, UMR 5582, CNRS-Université Grenoble I, BP 74, 38402 Saint-Martin d’Hères (France); Merkli, Marco, E-mail: merkli@mun.ca [Department of Mathematics and Statistics Memorial University of Newfoundland, St. John' s, NL Canada A1C 5S7 (Canada)

    2014-07-15

    Analyzing the dynamics of open quantum systems has a long history in mathematics and physics. Depending on the system at hand, basic physical phenomena that one would like to explain are, for example, convergence to equilibrium, the dynamics of quantum coherences (decoherence) and quantum correlations (entanglement), or the emergence of heat and particle fluxes in non-equilibrium situations. From the mathematical physics perspective, one of the main challenges is to derive the irreversible dynamics of the open system, starting from a unitary dynamics of the system and its environment. The repeated interactions systems considered in these notes are models of non-equilibrium quantum statistical mechanics. They are relevant in quantum optics, and more generally, serve as a relatively well treatable approximation of a more difficult quantum dynamics. In particular, the repeated interaction models allow to determine the large time (stationary) asymptotics of quantum systems out of equilibrium.

  20. Toxicological characteristics of petroleum products repeated exposure

    Directory of Open Access Journals (Sweden)

    V.M. Rubin

    2015-03-01

    Full Text Available Abstract. The ability of petroleum products to initiate cumulative effects was assessed in experimental intragastric admission to male albino rats for one month. The analysis of skin-resorptive effects was performed using "test-tube" method on the skin of rats’ tails. It has been established that petroleum products can penetrate the intact skin and, with repeated admission, cause a general toxic effect. There were reductions bodyweights, the negative effect on the function of the kidneys and liver, changes of hematological parameters, as well as activation of the antioksidatnoy system. Repeated intragastric administration does not lead to the death of the animals testifying to the lack of accumulation capacity for petroleum products at the level of functional mortal effects, the cumulation coefficient being > 5.1. Negative impact on urinary function and hepatobiliary system, changes in hematological parameters and activation of the «lipid peroxidation – antioksidant defense» were observed.

  1. Childhood experiences and repeated suicidal behavior

    DEFF Research Database (Denmark)

    Krarup, Gertrud; Nielsen, Bent; Rask, P

    1991-01-01

    The aim of this study was to elucidate the influence of various events in childhood on suicidal behavior in adult age. For this purpose, 99 patients admitted to the Department of Psychiatry of Odense University Hospital after making a suicide attempt were followed for 5 years, to register repeated...... that the psychological climate of the home may be more important than the rupture of early home life. It is noteworthy that the group of repeaters, as against the first-evers, could be characterized by personality disorders and abuse, especially of alcohol: disorders known to be precipitated by a discordant childhood....... It is commonly agreed that the experience in childhood of suicidal behavior among family members or other persons in the close environment is of importance in future suicidal risk. The results of this study indicate that the predictive value of this factor mainly applies to attempts with no fatal outcome...

  2. Repeated radiation injuries by fission products

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.

    1986-01-01

    Attention is given to repeated radiation injuries during internal irradiation of theoretical and practical interest, particularly in case of the intake into organism of young products of nuclear fission (PNF). The results of experiments with dogs with repeated radioactive iodine injury the isotopes of which (131-135sub(I)) constitute a considerable part of PNF activity are discussed. The blood reaction and protein metabolism state have been studied. Observations for dogs have been continued for about 4 years. The doses for thyroid, gastrointestinal tract and liver subjected to the most intensive irradiation consituted in the first series of experiments after the first intake about 3;0.3;0.05 Gy, after the second - 5;0.5;0.08 Gy and in the second series of experiments - 3;0.3;0.05 Gy and 0.6;0.06;0.01 Gy, respectively. Hematologic factors,thyroid function, changes in exchange and immunologic reactivity have been studied. The dogs have been under observation for 5 years. It is shown in case of repeated intake of Isup(131) PNF into animals organism in quantity which does not cause during the acute period a clinically outlined sickness, substantial differences in the organism reaction as compared with the first intake of radionuclides have not been found. The presence of residual radiation injuries did not cause charging action during the acute period during PNF and repeated intake which in the author's opinion testifies to perfection of compensator mechanisms in case of intake of such quantities of radioactive products. At the remote periods blastomogenic action manifested which is estimated as a result of general biological action of radionuclides administered to the organism. The necessity in subsequent investigations for obtaining the data on organism reactivity, clinic and pathogenesis with the aim of prophylaxis and treatment of such injuries is indicated

  3. Repeated extraction of DNA from FTA cards

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Ferrero, Laura; Børsting, Claus

    2011-01-01

    Extraction of DNA using magnetic bead based techniques on automated DNA extraction instruments provides a fast, reliable and reproducible method for DNA extraction from various matrices. However, the yield of extracted DNA from FTA-cards is typically low. Here, we demonstrate that it is possible...... to repeatedly extract DNA from the processed FTA-disk. The method increases the yield from the nanogram range to the microgram range....

  4. Electrochemical detection of DNA triplet repeat expansion

    Czech Academy of Sciences Publication Activity Database

    Fojta, Miroslav; Havran, Luděk; Vojtíšková, Marie; Paleček, Emil

    2004-01-01

    Roč. 126, č. 21 (2004), s. 6532-6533 ISSN 0002-7863 R&D Projects: GA AV ČR IAA4004402; GA AV ČR IBS5004355; GA AV ČR KJB4004302; GA AV ČR KSK4055109 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA triplet repeat expansion * PCR amplification * neurodegenerative diseases Subject RIV: BO - Biophysics Impact factor: 6.903, year: 2004

  5. Repeatability and Workability Evaluation of SIGMOD 2011

    DEFF Research Database (Denmark)

    2011-01-01

    SIGMOD has offered, since 2008, to verify the experiments published in the papers accepted at the conference. This year, we have been in charge of reproducing the experiments provided by the authors (repeatability), and exploring changes to experiment parameters (workability). In this paper, we a...... find that most experiments are distributed as Linux packages accompanied by instructions on how to setup and run the experiments. We are still far from the vision of executable papers...

  6. Repeat Stereotactic Radiosurgery for Acoustic Neuromas

    International Nuclear Information System (INIS)

    Kano, Hideyuki; Kondziolka, Douglas; Niranjan, Ajay M.Ch.; Flannery, Thomas J.; Flickinger, John C.; Lunsford, L. Dade

    2010-01-01

    Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months). Results: At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS. Conclusions: With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.

  7. A Unified Model for Repeating and Non-repeating Fast Radio Bursts

    International Nuclear Information System (INIS)

    Bagchi, Manjari

    2017-01-01

    The model that fast radio bursts (FRBs) are caused by plunges of asteroids onto neutron stars can explain both repeating and non-repeating bursts. If a neutron star passes through an asteroid belt around another star, there would be a series of bursts caused by a series of asteroid impacts. Moreover, the neutron star would cross the same belt repetitively if it were in a binary with the star hosting the asteroid belt, leading to a repeated series of bursts. I explore the properties of neutron star binaries that could lead to the only known repeating FRB so far (FRB121102). In this model, the next two epochs of bursts are expected around 2017 February 27 and 2017 December 18. On the other hand, if the asteroid belt is located around the neutron star itself, then a chance fall of an asteroid from that belt onto the neutron star would lead to a non-repeating burst. Even a neutron star grazing an asteroid belt can lead to a non-repeating burst caused by just one asteroid plunge during the grazing. This is possible even when the neutron star is in a binary with the asteroid-hosting star, if the belt and the neutron star orbit are non-coplanar.

  8. A Unified Model for Repeating and Non-repeating Fast Radio Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Bagchi, Manjari, E-mail: manjari@imsc.res.in [The Institute of Mathematical Sciences (IMSc-HBNI), 4th Cross Road, CIT Campus, Taramani, Chennai 600113 (India)

    2017-04-01

    The model that fast radio bursts (FRBs) are caused by plunges of asteroids onto neutron stars can explain both repeating and non-repeating bursts. If a neutron star passes through an asteroid belt around another star, there would be a series of bursts caused by a series of asteroid impacts. Moreover, the neutron star would cross the same belt repetitively if it were in a binary with the star hosting the asteroid belt, leading to a repeated series of bursts. I explore the properties of neutron star binaries that could lead to the only known repeating FRB so far (FRB121102). In this model, the next two epochs of bursts are expected around 2017 February 27 and 2017 December 18. On the other hand, if the asteroid belt is located around the neutron star itself, then a chance fall of an asteroid from that belt onto the neutron star would lead to a non-repeating burst. Even a neutron star grazing an asteroid belt can lead to a non-repeating burst caused by just one asteroid plunge during the grazing. This is possible even when the neutron star is in a binary with the asteroid-hosting star, if the belt and the neutron star orbit are non-coplanar.

  9. Prevention of infectious tick-borne diseases in humans: Comparative studies of the repellency of different dodecanoic acid-formulations against Ixodes ricinus ticks (Acari: Ixodidae

    Directory of Open Access Journals (Sweden)

    Dautel Hans

    2008-04-01

    Full Text Available Abstract Background Ticks of the species Ixodes ricinus are the main vectors of Lyme Borreliosis and Tick-borne Encephalitis – two rapidly emerging diseases in Europe. Repellents provide a practical means of protection against tick bites and can therefore minimize the transmission of tick-borne diseases. We developed and tested seven different dodecanoic acid (DDA-formulations for their efficacy in repelling host-seeking nymphs of I. ricinus by laboratory screening. The ultimately selected formulation was then used for comparative investigations of commercially available tick repellents in humans. Methods Laboratory screening tests were performed using the Moving-object (MO bioassay. All test formulations contained 10% of the naturally occurring active substance DDA and differed only in terms of the quantitative and qualitative composition of inactive ingredients and fragrances. The test procedure used in the human bioassays is a modification of an assay described by the U.S. Environmental Protection Agency and recommended for regulatory affairs. Repellency was computed using the equation: R = 100 - NR/N × 100, where NR is the number of non-repelled ticks, and N is the respective number of control ticks. All investigations were conducted in a controlled laboratory environment offering standardized test conditions. Results All test formulations strongly repelled nymphs of I. ricinus (100-81% protection as shown by the MO-bioassay. The majority of ticks dropped off the treated surface of the heated rotating drum that served as the attractant (1 mg/cm2 repellent applied. The 10% DDA-based formulation, that produced the best results in laboratory screening, was as effective as the coconut oil-based reference product. The mean protection time of both preparations was generally similar and averaged 8 hours. Repellency investigations in humans showed that the most effective 10% DDA-based formulation (~1.67 mg/cm2 applied strongly avoided the

  10. Approaches for Reverse Line Blot-Based Detection of Microbial Pathogens in Ixodes ricinus Ticks Collected in Austria and Impact of the Chosen Method.

    Science.gov (United States)

    Schötta, Anna-Margarita; Wijnveld, Michiel; Stockinger, Hannes; Stanek, Gerold

    2017-07-01

    Ticks transmit a large number of pathogens capable of causing human disease. In this study, the PCR-reverse line blot (RLB) method was used to screen for pathogens in a total of 554 Ixodes ricinus ticks collected from all provinces of Austria. These pathogens belong to the genera Borrelia , Rickettsiae , Anaplasma / Ehrlichia (including " Candidatus Neoehrlichia"), Babesia , and Coxiella The pathogens with the highest detected prevalence were spirochetes of the Borrelia burgdorferi sensu lato complex, in 142 ticks (25.6%). Borrelia afzelii (80/142) was the most frequently detected species, followed by Borrelia burgdorferi sensu stricto (38/142) and Borrelia valaisiana (36/142). Borrelia garinii/Borrelia bavariensis , Borrelia lusitaniae , and Borrelia spielmanii were found in 28 ticks, 5 ticks, and 1 tick, respectively. Rickettsia spp. were detected in 93 ticks (16.8%): R. helvetica (39/93), R. raoultii (38/93), R. monacensis (2/93), and R. slovaca (1/93). Thirteen Rickettsia samples remain uncharacterized. " Candidatus Neoehrlichia mikurensis," Babesia spp. ( B. venatorum , B. divergens , B. microti ), and Anaplasma phagocytophilum were found in 4.5%, 2.7%, and 0.7%, respectively. Coxiella burnetii was not detected. Multiple microorganisms were detected in 40 ticks (7.2%), and the cooccurrence of Babesia spp. and " Candidatus Neoehrlichia mikurensis" showed a significant positive correlation. We also compared different PCR-RLBs for detection of Borrelia burgdorferi sensu lato and Rickettsia spp. and showed that different detection approaches provide highly diverse results, indicating that analysis of environmental samples remains challenging. IMPORTANCE This study determined the wide spectrum of tick-borne bacterial and protozoal pathogens that can be encountered in Austria. Surveillance of (putative) pathogenic microorganisms occurring in the environment is of medical importance, especially when those agents can be transmitted by ticks and cause disease. The

  11. Identifying uniformly mutated segments within repeats.

    Science.gov (United States)

    Sahinalp, S Cenk; Eichler, Evan; Goldberg, Paul; Berenbrink, Petra; Friedetzky, Tom; Ergun, Funda

    2004-12-01

    Given a long string of characters from a constant size alphabet we present an algorithm to determine whether its characters have been generated by a single i.i.d. random source. More specifically, consider all possible n-coin models for generating a binary string S, where each bit of S is generated via an independent toss of one of the n coins in the model. The choice of which coin to toss is decided by a random walk on the set of coins where the probability of a coin change is much lower than the probability of using the same coin repeatedly. We present a procedure to evaluate the likelihood of a n-coin model for given S, subject a uniform prior distribution over the parameters of the model (that represent mutation rates and probabilities of copying events). In the absence of detailed prior knowledge of these parameters, the algorithm can be used to determine whether the a posteriori probability for n=1 is higher than for any other n>1. Our algorithm runs in time O(l4logl), where l is the length of S, through a dynamic programming approach which exploits the assumed convexity of the a posteriori probability for n. Our test can be used in the analysis of long alignments between pairs of genomic sequences in a number of ways. For example, functional regions in genome sequences exhibit much lower mutation rates than non-functional regions. Because our test provides means for determining variations in the mutation rate, it may be used to distinguish functional regions from non-functional ones. Another application is in determining whether two highly similar, thus evolutionarily related, genome segments are the result of a single copy event or of a complex series of copy events. This is particularly an issue in evolutionary studies of genome regions rich with repeat segments (especially tandemly repeated segments).

  12. Multivariate linear models and repeated measurements revisited

    DEFF Research Database (Denmark)

    Dalgaard, Peter

    2009-01-01

    Methods for generalized analysis of variance based on multivariate normal theory have been known for many years. In a repeated measurements context, it is most often of interest to consider transformed responses, typically within-subject contrasts or averages. Efficiency considerations leads...... to sphericity assumptions, use of F tests and the Greenhouse-Geisser and Huynh-Feldt adjustments to compensate for deviations from sphericity. During a recent implementation of such methods in the R language, the general structure of such transformations was reconsidered, leading to a flexible specification...

  13. Repeat Sequence Proteins as Matrices for Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Drummy, L.; Koerner, H; Phillips, D; McAuliffe, J; Kumar, M; Farmer, B; Vaia, R; Naik, R

    2009-01-01

    Recombinant protein-inorganic nanocomposites comprised of exfoliated Na+ montmorillonite (MMT) in a recombinant protein matrix based on silk-like and elastin-like amino acid motifs (silk elastin-like protein (SELP)) were formed via a solution blending process. Charged residues along the protein backbone are shown to dominate long-range interactions, whereas the SELP repeat sequence leads to local protein/MMT compatibility. Up to a 50% increase in room temperature modulus and a comparable decrease in high temperature coefficient of thermal expansion occur for cast films containing 2-10 wt.% MMT.

  14. Mechanical processes with repeated attenuated impacts

    CERN Document Server

    Nagaev, R F

    1999-01-01

    This book is devoted to considering in the general case - using typical concrete examples - the motion of machines and mechanisms of impact and vibro-impact action accompanied by a peculiar phenomenon called "impact collapse". This phenomenon is that after the initial collision, a sequence of repeated gradually quickening collisions of decreasing-to-zero intensity occurs, with the final establishment of protracted contact between the interacting bodies. The initiation conditions of the impact collapse are determined and calculation techniques for the quantitative characteristics of the corresp

  15. Development of repeating pneumatic pellet injector

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Y.; Onozuka, M.; Shimomura, T. (Mitsubishi Heavy Industries Ltd., Kobe (Japan)) (and others)

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s{sup -1}, chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s{sup -1}, as planned. (author).

  16. Development of repeating pneumatic pellet injector

    International Nuclear Information System (INIS)

    Oda, Y.; Onozuka, M.; Shimomura, T.

    1990-01-01

    A repeating pneumatic pellet injector has been constructed to experiment with the technique of continuous injection for fueling fusion reactors. This device is composed of a cryogenic extruder and a gun assembly in (among others) a high-vacuum vessel, diagnostic vessels, LHe, fuel-gas and propellant-gas supply systems, control and data acquisition systems, etc. The performance tests, using hydrogen, have proved that the device provides the function of extruding frozen hydrogen ribbons at the speed of 6 mm s -1 , chambering pellet at the rate of 5 Hz, and injecting pellet at the speed of 900 m s -1 , as planned. (author)

  17. Extending Teach and Repeat to Pivoting Wheelchairs

    Directory of Open Access Journals (Sweden)

    Guillermo Del Castillo

    2003-02-01

    Full Text Available The paper extends the teach-and-repeat paradigm that has been successful for the control of holonomic robots to nonholonomic wheelchairs which may undergo pivoting action over the course of their taught movement. Due to the nonholonomic nature of the vehicle kinematics, estimation is required -- in the example given herein, based upon video detection of wall-mounted cues -- both in the teaching and the tracking events. In order to accommodate motion that approaches pivoting action as well as motion that approaches straight-line action, the estimation equations of the Extended Kalman Filter and the control equations are formulated using two different definitions of a nontemporal independent variable. The paper motivates the need for pivoting action in real-life settings by reporting extensively on the abilities and limitations of estimation-based teach-and-repeat action where pivoting and near-pivoting action is disallowed. Following formulation of the equations in the near-pivot mode, the paper reports upon experiments where taught trajectories which entail a seamless mix of near-straight and near-pivot action are tracked.

  18. Repeated proton beam therapy for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Hashimoto, Takayuki; Tokuuye, Koichi; Fukumitsu, Nobuyoshi; Igaki, Hiroshi; Hata, Masaharu; Kagei, Kenji; Sugahara, Shinji; Ohara, Kiyoshi; Matsuzaki, Yasushi; Akine, Yasuyuki

    2006-01-01

    Purpose: To retrospectively evaluate the safety and effectiveness of repeated proton beam therapy for newly developed or recurrent hepatocellular carcinoma (HCC). Methods and Materials: From June 1989 through July 2000, 225 patients with HCC underwent their first course of proton beam therapy at University of Tsukuba. Of them, 27 with 68 lesions who had undergone two or more courses were retrospectively reviewed in this study. Median interval between the first and second course was 24.5 months (range 3.3-79.8 months). Median total dose of 72 Gy in 16 fractions and 66 Gy in 16 fractions were given for the first course and the rest of the courses, respectively. Results: The 5-year survival rate and median survival period from the beginning of the first course for the 27 patients were 55.6% and 62.2 months, respectively. Five-year local control rate for the 68 lesions was 87.8%. Of the patients, 1 with Child-Pugh class B and another with class C before the last course suffered from acute hepatic failure. Conclusions: Repeated proton beam therapy for HCC is safe when the patient has a target in the peripheral region of the liver and liver function is Child-Pugh class A

  19. Chromosome-specific DNA Repeat Probes

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Adolf; Weier, Jingly Fung; Weier, Heinz-Ulrich G.

    2006-03-16

    In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with {alpha}-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.

  20. Aggregating quantum repeaters for the quantum internet

    Science.gov (United States)

    Azuma, Koji; Kato, Go

    2017-09-01

    The quantum internet holds promise for accomplishing quantum teleportation and unconditionally secure communication freely between arbitrary clients all over the globe, as well as the simulation of quantum many-body systems. For such a quantum internet protocol, a general fundamental upper bound on the obtainable entanglement or secret key has been derived [K. Azuma, A. Mizutani, and H.-K. Lo, Nat. Commun. 7, 13523 (2016), 10.1038/ncomms13523]. Here we consider its converse problem. In particular, we present a universal protocol constructible from any given quantum network, which is based on running quantum repeater schemes in parallel over the network. For arbitrary lossy optical channel networks, our protocol has no scaling gap with the upper bound, even based on existing quantum repeater schemes. In an asymptotic limit, our protocol works as an optimal entanglement or secret-key distribution over any quantum network composed of practical channels such as erasure channels, dephasing channels, bosonic quantum amplifier channels, and lossy optical channels.

  1. Performance Comparisons of Improved Regular Repeat Accumulate (RA and Irregular Repeat Accumulate (IRA Turbo Decoding

    Directory of Open Access Journals (Sweden)

    Ahmed Abdulkadhim Hamad

    2017-08-01

    Full Text Available In this paper, different techniques are used to improve the turbo decoding of regular repeat accumulate (RA and irregular repeat accumulate (IRA codes. The adaptive scaling of a-posteriori information produced by Soft-output Viterbi decoder (SOVA is proposed. The encoded pilots are another scheme that applied for short length RA codes. This work also suggests a simple and a fast method to generate a random interleaver having a free 4 cycle Tanner graph. Progressive edge growth algorithm (PEG is also studied and simulated to create the Tanner graphs which have a great girth.

  2. Contraceptive Use among Women Seeking Repeat Abortion in ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    Compared with women seeking their first abortion, significantly more repeat abortion clients had ever used contraceptives ... findings, the level of repeat abortions in Europe, .... and contraceptive history, and post-abortion ..... working women.

  3. Methods for analysing cardiovascular studies with repeated measures

    NARCIS (Netherlands)

    Cleophas, T. J.; Zwinderman, A. H.; van Ouwerkerk, B. M.

    2009-01-01

    Background. Repeated measurements in a single subject are generally more similar than unrepeated measurements in different subjects. Unrepeated analyses of repeated data cause underestimation of the treatment effects. Objective. To review methods adequate for the analysis of cardiovascular studies

  4. Discrepancies in reporting the CAG repeat lengths for Huntington's disease

    DEFF Research Database (Denmark)

    Quarrell, Oliver W; Handley, Olivia; O'Donovan, Kirsty

    2011-01-01

    Huntington's disease results from a CAG repeat expansion within the Huntingtin gene; this is measured routinely in diagnostic laboratories. The European Huntington's Disease Network REGISTRY project centrally measures CAG repeat lengths on fresh samples; these were compared with the original...

  5. The absolute number of repeat operations for complex intra ...

    African Journals Online (AJOL)

    abdominal sepsis, questions about futility of treatment frequently arise. This study focuses specifically on patients who required two or more repeat laparotomies and describes the spectrum of disease necessitating multiple repeat laparotomies ...

  6. Novel expressed sequence tag- simple sequence repeats (EST ...

    African Journals Online (AJOL)

    Using different bioinformatic criteria, the SUCEST database was used to mine for simple sequence repeat (SSR) markers. Among 42,189 clusters, 1,425 expressed sequence tag- simple sequence repeats (EST-SSRs) were identified in silico. Trinucleotide repeats were the most abundant SSRs detected. Of 212 primer pairs ...

  7. Erroneous Memories Arising from Repeated Attempts to Remember

    Science.gov (United States)

    Henkel, Linda A.

    2004-01-01

    The impact of repeated and prolonged attempts at remembering on false memory rates was assessed in three experiments. Participants saw and imagined pictures and then made repeated recall attempts before taking a source memory test. Although the number of items recalled increased with repeated tests, the net gains were associated with more source…

  8. Adaptation and complexity in repeated games

    DEFF Research Database (Denmark)

    Maenner, Eliot Alexander

    2008-01-01

    The paper presents a learning model for two-player infinitely repeated games. In an inference step players construct minimally complex inferences of strategies based on observed play, and in an adaptation step players choose minimally complex best responses to an inference. When players randomly...... select an inference from a probability distribution with full support the set of steady states is a subset of the set of Nash equilibria in which only stage game Nash equilibria are played. When players make ‘cautious' inferences the set of steady states is the subset of self-confirming equilibria...... with Nash outcome paths. When players use different inference rules, the set of steady states can lie between the previous two cases...

  9. Aging and repeated thought suppression success.

    Directory of Open Access Journals (Sweden)

    Ann E Lambert

    Full Text Available Intrusive thoughts and attempts to suppress them are common, but while suppression may be effective in the short-term, it can increase thought recurrence in the long-term. Because intentional suppression involves controlled processing, and many aspects of controlled processing decline with age, age differences in thought suppression outcomes may emerge, especially over repeated thought suppression attempts as cognitive resources are expended. Using multilevel modeling, we examined age differences in reactions to thought suppression attempts across four thought suppression sequences in 40 older and 42 younger adults. As expected, age differences were more prevalent during suppression than during free monitoring periods, with younger adults indicating longer, more frequent thought recurrences and greater suppression difficulty. Further, younger adults' thought suppression outcomes changed over time, while trajectories for older adults' were relatively stable. Results are discussed in terms of older adults' reduced thought recurrence, which was potentially afforded by age-related changes in reactive control and distractibility.

  10. Who Repeats Algebra, and How Does Initial Performance Relate to Improvement When the Course Is Repeated?

    Science.gov (United States)

    Fong, Anthony; Jaquet, Karina; Finkelstein, Neal

    2016-01-01

    The information provided in this report shows how students perform when they repeat algebra I and how the level of improvement varies depending on initial course performance and the academic measure (course grades or CST scores). This information can help inform decisions and policies regarding whether and under what circumstances students should…

  11. Repeat Gamma Knife surgery for vestibular schwannomas

    Science.gov (United States)

    Lonneville, Sarah; Delbrouck, Carine; Renier, Cécile; Devriendt, Daniel; Massager, Nicolas

    2015-01-01

    Background: Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases. Methods: A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The median margin dose used for the first, second, and third GK treatments was 12 Gy, 12 Gy, and 14 Gy, respectively. Six patients (4 patients for the second irradiation and 2 patients for the third irradiation) with partial tumor regrowth were treated only on the growing part of the tumor using a median margin dose of 13 Gy. The median tumor volume was 0.9, 2.3, and 0.7 cc for the first, second, and third treatments, respectively. Stereotactic positron emission tomography (PET) guidance was used for dose planning in 6 cases. Results: Mean follow-up duration was 46 months (range 24–110). At the last follow-up, 85% of schwannomas were controlled. The tumor volume decreased, remained unchanged, or increased after retreatment in 15, 8, and 4 cases, respectively. Four patients had PET during follow-up, and all showed a significant metabolic decrease of the tumor. Hearing was not preserved after retreatment in any patients. New facial or trigeminal palsy did not occur after retreatment. Conclusions: Our results support the long-term efficacy and low morbidity of repeat GK treatment for selected patients with tumor growth after initial treatment. PMID:26500799

  12. In situ detection of tandem DNA repeat length

    Energy Technology Data Exchange (ETDEWEB)

    Yaar, R.; Szafranski, P.; Cantor, C.R.; Smith, C.L. [Boston Univ., MA (United States)

    1996-11-01

    A simple method for scoring short tandem DNA repeats is presented. An oligonucleotide target, containing tandem repeats embedded in a unique sequence, was hybridized to a set of complementary probes, containing tandem repeats of known lengths. Single-stranded loop structures formed on duplexes containing a mismatched (different) number of tandem repeats. No loop structure formed on duplexes containing a matched (identical) number of tandem repeats. The matched and mismatched loop structures were enzymatically distinguished and differentially labeled by treatment with S1 nuclease and the Klenow fragment of DNA polymerase. 7 refs., 4 figs.

  13. Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

    Science.gov (United States)

    Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

    2009-10-01

    Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

  14. Studies on Section XI ultrasonic repeatability

    International Nuclear Information System (INIS)

    Jamison, T.D.; McDearman, W.R.

    1981-05-01

    A block representative of a nuclear component has been welded containing intentional defects. Acoustic emission data taken during the welding correlate well with ultrasonic data. Repetitive ultrasonic examinations have been performed by skilled operators using a procedure based on that desribed in ASME Section XI. These examinations were performed by different examination teams using different ultrasonic equipment in such a manner that the effects on the repeatability of the ultrasonic test method caused by the operator and by the use of different equipment could be estimated. It was tentatively concluded that when considering a large number of inspections: (1) there is no significant difference in indication sizing between operators, and (2) there is a significant difference in amplitude and defect sizing when instruments having different, Code acceptable operating characteristics are used. It was determined that the Section XI sizing parameters follow a bivariate normal distribution. Data derived from ultrasonically and physically sizing indications in nuclear components during farication show that the Section XI technique tends to overestimate the size of the reflectors

  15. Short tandem repeat analysis in Japanese population.

    Science.gov (United States)

    Hashiyada, M

    2000-01-01

    Short tandem repeats (STRs), known as microsatellites, are one of the most informative genetic markers for characterizing biological materials. Because of the relatively small size of STR alleles (generally 100-350 nucleotides), amplification by polymerase chain reaction (PCR) is relatively easy, affording a high sensitivity of detection. In addition, STR loci can be amplified simultaneously in a multiplex PCR. Thus, substantial information can be obtained in a single analysis with the benefits of using less template DNA, reducing labor, and reducing the contamination. We investigated 14 STR loci in a Japanese population living in Sendai by three multiplex PCR kits, GenePrint PowerPlex 1.1 and 2.2. Fluorescent STR System (Promega, Madison, WI, USA) and AmpF/STR Profiler (Perkin-Elmer, Norwalk, CT, USA). Genomic DNA was extracted using sodium dodecyl sulfate (SDS) proteinase K or Chelex 100 treatment followed by the phenol/chloroform extraction. PCR was performed according to the manufacturer's protocols. Electrophoresis was carried out on an ABI 377 sequencer and the alleles were determined by GeneScan 2.0.2 software (Perkin-Elmer). In 14 STRs loci, statistical parameters indicated a relatively high rate, and no significant deviation from Hardy-Weinberg equilibrium was detected. We apply this STR system to paternity testing and forensic casework, e.g., personal identification in rape cases. This system is an effective tool in the forensic sciences to obtain information on individual identification.

  16. A Repeated Signal Difference for Recognising Patterns

    Directory of Open Access Journals (Sweden)

    Kieran Greer

    2016-08-01

    Full Text Available This paper describes a new mechanism that might help with defining pattern sequences, by the fact that it can produce an upper bound on the ensemble value that can persistently oscillate with the actual values produced from each pattern. With every firing event, a node also receives an on/off feedback switch. If the node fires then it sends a feedback result depending on the input signal strength. If the input signal is positive or larger, it can store an ‘on’ switch feedback for the next iteration. If the signal is negative or smaller it can store an ‘off’ switch feedback for the next iteration. If the node does not fire, then it does not affect the current feedback situation and receives the switch command produced by the last active pattern event for the same neuron. The upper bound therefore also represents the largest or most enclosing pattern set and the lower value is for the actual set of firing patterns. If the pattern sequence repeats, it will oscillate between the two values, allowing them to be recognised and measured more easily, over time. Tests show that changing the sequence ordering produces different value sets, which can also be measured.

  17. Repeated intravenous doxapram induces phrenic motor facilitation.

    Science.gov (United States)

    Sandhu, M S; Lee, K Z; Gonzalez-Rothi, E J; Fuller, D D

    2013-12-01

    Doxapram is a respiratory stimulant used to treat hypoventilation. Here we investigated whether doxapram could also trigger respiratory neuroplasticity. Specifically, we hypothesized that intermittent delivery of doxapram at low doses would lead to long-lasting increases (i.e., facilitation) of phrenic motor output in anesthetized, vagotomized, and mechanically-ventilated rats. Doxapram was delivered intravenously in a single bolus (2 or 6mg/kg) or as a series of 3 injections (2mg/kg) at 5min intervals. Control groups received pH-matched saline injections (vehicle) or no treatment (anesthesia time control). Doxapram evoked an immediate increase in phrenic output in all groups, but a persistent increase in burst amplitude only occurred after repeated dosing with 2mg/kg. At 60min following the last injection, phrenic burst amplitude was 168±24% of baseline (%BL) in the group receiving 3 injections (Pphrenic response to doxapram (2mg/kg) was reduced by 68% suggesting that at low doses the drug was acting primarily via the carotid chemoreceptors. We conclude that intermittent application of doxapram can trigger phrenic neuroplasticity, and this approach might be of use in the context of respiratory rehabilitation following neurologic injury. © 2013.

  18. Superfamily of ankyrin repeat proteins in tomato.

    Science.gov (United States)

    Yuan, Xiaowei; Zhang, Shizhong; Qing, Xiaohe; Sun, Meihong; Liu, Shiyang; Su, Hongyan; Shu, Huairui; Li, Xinzheng

    2013-07-10

    The ankyrin repeat (ANK) protein family plays a crucial role in plant growth and development and in response to biotic and abiotic stresses. However, no detailed information concerning this family is available for tomato (Solanum lycopersicum) due to the limited information on whole genome sequences. In this study, we identified a total of 130 ANK genes in tomato genome (SlANK), and these genes were distributed across all 12 chromosomes at various densities. And chromosomal localizations of SlANK genes indicated 25 SlANK genes were involved in tandem duplications. Based on their domain composition, all of the SlANK proteins were grouped into 13 subgroups. A combined phylogenetic tree was constructed with the aligned SlANK protein sequences. This tree revealed that the SlANK proteins comprise five major groups. An analysis of the expression profiles of SlANK genes in tomato in different tissues and in response to stresses showed that the SlANK proteins play roles in plant growth, development and stress responses. To our knowledge, this is the first report of a genome-wide analysis of the tomato ANK gene family. This study provides valuable information regarding the classification and putative functions of SlANK genes in tomato. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  19. Multineuronal Spike Sequences Repeat with Millisecond Precision

    Directory of Open Access Journals (Sweden)

    Koki eMatsumoto

    2013-06-01

    Full Text Available Cortical microcircuits are nonrandomly wired by neurons. As a natural consequence, spikes emitted by microcircuits are also nonrandomly patterned in time and space. One of the prominent spike organizations is a repetition of fixed patterns of spike series across multiple neurons. However, several questions remain unsolved, including how precisely spike sequences repeat, how the sequences are spatially organized, how many neurons participate in sequences, and how different sequences are functionally linked. To address these questions, we monitored spontaneous spikes of hippocampal CA3 neurons ex vivo using a high-speed functional multineuron calcium imaging technique that allowed us to monitor spikes with millisecond resolution and to record the location of spiking and nonspiking neurons. Multineuronal spike sequences were overrepresented in spontaneous activity compared to the statistical chance level. Approximately 75% of neurons participated in at least one sequence during our observation period. The participants were sparsely dispersed and did not show specific spatial organization. The number of sequences relative to the chance level decreased when larger time frames were used to detect sequences. Thus, sequences were precise at the millisecond level. Sequences often shared common spikes with other sequences; parts of sequences were subsequently relayed by following sequences, generating complex chains of multiple sequences.

  20. The effect of repeated testing vs repeated practice on skills learning in undergraduate dental education.

    Science.gov (United States)

    Sennhenn-Kirchner, S; Goerlich, Y; Kirchner, B; Notbohm, M; Schiekirka, S; Simmenroth, A; Raupach, T

    2018-02-01

    Recent studies in undergraduate medical education have demonstrated the advantage of repeated testing over repeated practice with regard to knowledge and skills retention. The aim of this study was to investigate whether this "testing effect" also applies to skills retention in undergraduate dental education. In this prospective, randomised controlled trial, fourth-year dental students at Göttingen University Medical Centre participated in a training session on surgical suturing in winter term 2014/2015. Following this, they were either assigned to two sessions of additional skills training (group A) or two sessions of skills assessment with feedback (group B). These sessions were spaced over a period of 4 weeks. Skills retention was assessed in a summative objective structured clinical examination (OSCE) at the end of term, that is 6 months after the initial teaching session. A total of 32 students completed the study. With regard to suturing, OSCE performance was significantly better in group B than group A (81.9±13.1% vs 63.0±15.4%; P=0.001; Cohen's d=1.33). There was no significant OSCE performance difference in the two groups with regard to other learning objectives that were addressed in the end-of-term examination. Thus, the group difference was specific to suturing skills. This is the first study to demonstrate that in dental education, repeated testing produces more favourable skills retention than repeated practice. Test-enhanced learning might be a viable concept for skills retention in undergraduate dentistry education. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. ATXN2 trinucleotide repeat length correlates with risk of ALS.

    Science.gov (United States)

    Sproviero, William; Shatunov, Aleksey; Stahl, Daniel; Shoai, Maryam; van Rheenen, Wouter; Jones, Ashley R; Al-Sarraj, Safa; Andersen, Peter M; Bonini, Nancy M; Conforti, Francesca L; Van Damme, Philip; Daoud, Hussein; Del Mar Amador, Maria; Fogh, Isabella; Forzan, Monica; Gaastra, Ben; Gellera, Cinzia; Gitler, Aaron D; Hardy, John; Fratta, Pietro; La Bella, Vincenzo; Le Ber, Isabelle; Van Langenhove, Tim; Lattante, Serena; Lee, Yi-Chung; Malaspina, Andrea; Meininger, Vincent; Millecamps, Stéphanie; Orrell, Richard; Rademakers, Rosa; Robberecht, Wim; Rouleau, Guy; Ross, Owen A; Salachas, Francois; Sidle, Katie; Smith, Bradley N; Soong, Bing-Wen; Sorarù, Gianni; Stevanin, Giovanni; Kabashi, Edor; Troakes, Claire; van Broeckhoven, Christine; Veldink, Jan H; van den Berg, Leonard H; Shaw, Christopher E; Powell, John F; Al-Chalabi, Ammar

    2017-03-01

    We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we systematically searched PubMed for case-control studies published after 1 August 2010 that investigated the association between ATXN2 intermediate repeats and ALS. We conducted a meta-analysis of the new and existing studies for the relative risks of ATXN2 intermediate repeat alleles of between 24 and 34 CAG trinucleotide repeats and ALS. There was an overall increased risk of ALS for those carrying intermediate sized trinucleotide repeat alleles (odds ratio 3.06 [95% confidence interval 2.37-3.94]; p = 6 × 10 -18 ), with an exponential relationship between repeat length and ALS risk for alleles of 29-32 repeats (R 2  = 0.91, p = 0.0002). No relationship was seen for repeat length and age of onset or survival. In contrast to trinucleotide repeat diseases, intermediate ATXN2 trinucleotide repeat expansion in ALS does not predict age of onset but does predict disease risk. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  2. Repeated pulsed x-ray emission equipment

    International Nuclear Information System (INIS)

    Terauchi, Hikaru; Iida, Satoshi

    1982-01-01

    X-ray diffraction technique has been applied to determine the spatial positions of atoms which compose a material, and it is needless to say that the technique is a fundamental means regardless of the fields of research. However, the application of X-ray diffraction to the research on physical properties has been so far limited to know the spatial positions of atoms or molecules under thermal equilibrium condition. The addition of time element to the conventional technique, that is, the analysis of material structure including the time-varying processes under non-equilibrium conditions, is considered to approach the elucidation of the essence of materials. The authors call this dynamic structural analysis. The authors have planned to analyze X-ray diffraction intensity which has the resolution of about 10 -8 s in the real time which is conjugate with energy. However, present pulsed X-ray sources are not suitable for diffraction experiment because the pulse width is too long or X-ray wavelength is too short. Accordingly, the authors have made for trial a pulsed X-ray source for diffraction experiment. Its specifications are: diode voltage (X-ray tube voltage) from 200 to 300 kV, diode current from 2 to 5 kA, pulse width of about 30ns, maximum repetition frequency 10 pps, and X-ray focus size of 2 mm diameter. One of the features of this source is the repeated generation of pulsed X-ray. This is the first trial in the world, and is indispensable to the dynamic structural analysis described above. The quality of the emitted X-ray is also written. (Wakatsuki, Y.)

  3. Repeated speech errors: evidence for learning.

    Science.gov (United States)

    Humphreys, Karin R; Menzies, Heather; Lake, Johanna K

    2010-11-01

    Three experiments elicited phonological speech errors using the SLIP procedure to investigate whether there is a tendency for speech errors on specific words to reoccur, and whether this effect can be attributed to implicit learning of an incorrect mapping from lemma to phonology for that word. In Experiment 1, when speakers made a phonological speech error in the study phase of the experiment (e.g. saying "beg pet" in place of "peg bet") they were over four times as likely to make an error on that same item several minutes later at test. A pseudo-error condition demonstrated that the effect is not simply due to a propensity for speakers to repeat phonological forms, regardless of whether or not they have been made in error. That is, saying "beg pet" correctly at study did not induce speakers to say "beg pet" in error instead of "peg bet" at test. Instead, the effect appeared to be due to learning of the error pathway. Experiment 2 replicated this finding, but also showed that after 48 h, errors made at study were no longer more likely to reoccur. As well as providing constraints on the longevity of the effect, this provides strong evidence that the error reoccurrences observed are not due to item-specific difficulty that leads individual speakers to make habitual mistakes on certain items. Experiment 3 showed that the diminishment of the effect 48 h later is not due to specific extra practice at the task. We discuss how these results fit in with a larger view of language as a dynamic system that is constantly adapting in response to experience. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Established Population of Blacklegged Ticks with High Infection Prevalence for the Lyme Disease Bacterium, Borrelia burgdorferi Sensu Lato, on Corkscrew Island, Kenora District, Ontario

    Science.gov (United States)

    Scott, John D.; Foley, Janet E.; Clark, Kerry L.; Anderson, John F.; Durden, Lance A.; Manord, Jodi M.; Smith, Morgan L.

    2016-01-01

    We document an established population of blacklegged ticks, Ixodes scapularis, on Corkscrew Island, Kenora District, Ontario, Canada. Primers of the outer surface protein A (OspA) gene, the flagellin (fla) gene, and the flagellin B (flaB) gene were used in the PCR assays to detect Borrelia burgdorferi sensu lato (s.l.), the Lyme disease bacterium. In all, 60 (73%) of 82 adult I. scapularis, were infected with B. burgdorferi s.l. As well, 6 (43%) of 14 unfed I. scapularis nymphs were positive for B. burgdorferi s.l. An I. scapularis larva was also collected from a deer mouse, and several unfed larvae were gathered by flagging leaf litter. Based on DNA sequencing of randomly selected Borrelia amplicons from six nymphal and adult I. scapularis ticks, primers for the flagellin (fla) and flagellin B (flaB) genes reveal the presence of B. burgdorferi sensu stricto (s.s.), a genospecies pathogenic to humans and certain domestic animals. We collected all 3 host-feeding life stages of I. scapularis in a single year, and report the northernmost established population of I. scapularis in Ontario. Corkscrew Island is hyperendemic for Lyme disease and has the highest prevalence of B. burgdorferi s.l. for any established population in Canada. Because of this very high infection prevalence, this population of I. scapularis has likely been established for decades. Of epidemiological significance, cottage owners, island visitors, outdoors enthusiasts, and medical professionals must be vigilant that B. burgdorferi s.l.-infected I. scapularis on Corkscrew Island pose a serious public health risk. PMID:27877080

  5. Isolation of human simple repeat loci by hybridization selection.

    Science.gov (United States)

    Armour, J A; Neumann, R; Gobert, S; Jeffreys, A J

    1994-04-01

    We have isolated short tandem repeat arrays from the human genome, using a rapid method involving filter hybridization to enrich for tri- or tetranucleotide tandem repeats. About 30% of clones from the enriched library cross-hybridize with probes containing trimeric or tetrameric tandem arrays, facilitating the rapid isolation of large numbers of clones. In an initial analysis of 54 clones, 46 different tandem arrays were identified. Analysis of these tandem repeat loci by PCR showed that 24 were polymorphic in length; substantially higher levels of polymorphism were displayed by the tetrameric repeat loci isolated than by the trimeric repeats. Primary mapping of these loci by linkage analysis showed that they derive from 17 chromosomes, including the X chromosome. We anticipate the use of this strategy for the efficient isolation of tandem repeats from other sources of genomic DNA, including DNA from flow-sorted chromosomes, and from other species.

  6. Assembly of Repeat Content Using Next Generation Sequencing Data

    Energy Technology Data Exchange (ETDEWEB)

    labutti, Kurt; Kuo, Alan; Grigoriev, Igor; Copeland, Alex

    2014-03-17

    Repetitive organisms pose a challenge for short read assembly, and typically only unique regions and repeat regions shorter than the read length, can be accurately assembled. Recently, we have been investigating the use of Pacific Biosciences reads for de novo fungal assembly. We will present an assessment of the quality and degree of repeat reconstruction possible in a fungal genome using long read technology. We will also compare differences in assembly of repeat content using short read and long read technology.

  7. RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

    OpenAIRE

    Aisling Frizzell; Jennifer H.G. Nguyen; Mark I.R. Petalcorin; Katherine D. Turner; Simon J. Boulton; Catherine H. Freudenreich; Robert S. Lahue

    2014-01-01

    SUMMARY Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG·CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vi...

  8. Misleading Children: Causal Attributions of Inconsistency under Repeated Questioning.

    Science.gov (United States)

    Siegal, Michael; And Others

    1988-01-01

    Four studies investigated whether inconsistency of children aged four to six on developmental tasks may reflect a misinterpretation of the experimenter's intent in communication under repeated questioning. (SKC)

  9. Coexistence of 3G repeaters with LTE base stations.

    Science.gov (United States)

    Yeo, Woon-Young; Lee, Sang-Min; Hwang, Gyung-Ho; Kim, Jae-Hoon

    2013-01-01

    Repeaters have been an attractive solution for mobile operators to upgrade their wireless networks at low cost and to extend network coverage effectively. Since the first LTE commercial deployment in 2009, many mobile operators have launched LTE networks by upgrading their 3G and legacy networks. Because all 3G frequency bands are shared with the frequency bands for LTE deployment and 3G mobile operators have an enormous number of repeaters, reusing 3G repeaters in LTE networks is definitely a practical and cost-efficient solution. However, 3G repeaters usually do not support spatial multiplexing with multiple antennas, and thus it is difficult to reuse them directly in LTE networks. In order to support spatial multiplexing of LTE, the role of 3G repeaters should be replaced with small LTE base stations or MIMO-capable repeaters. In this paper, a repeater network is proposed to reuse 3G repeaters in LTE deployment while still supporting multilayer transmission of LTE. Interestingly, the proposed network has a higher cluster throughput than an LTE network with MIMO-capable repeaters.

  10. R-loops: targets for nuclease cleavage and repeat instability.

    Science.gov (United States)

    Freudenreich, Catherine H

    2018-01-11

    R-loops form when transcribed RNA remains bound to its DNA template to form a stable RNA:DNA hybrid. Stable R-loops form when the RNA is purine-rich, and are further stabilized by DNA secondary structures on the non-template strand. Interestingly, many expandable and disease-causing repeat sequences form stable R-loops, and R-loops can contribute to repeat instability. Repeat expansions are responsible for multiple neurodegenerative diseases, including Huntington's disease, myotonic dystrophy, and several types of ataxias. Recently, it was found that R-loops at an expanded CAG/CTG repeat tract cause DNA breaks as well as repeat instability (Su and Freudenreich, Proc Natl Acad Sci USA 114, E8392-E8401, 2017). Two factors were identified as causing R-loop-dependent breaks at CAG/CTG tracts: deamination of cytosines and the MutLγ (Mlh1-Mlh3) endonuclease, defining two new mechanisms for how R-loops can generate DNA breaks (Su and Freudenreich, Proc Natl Acad Sci USA 114, E8392-E8401, 2017). Following R-loop-dependent nicking, base excision repair resulted in repeat instability. These results have implications for human repeat expansion diseases and provide a paradigm for how RNA:DNA hybrids can cause genome instability at structure-forming DNA sequences. This perspective summarizes mechanisms of R-loop-induced fragility at G-rich repeats and new links between DNA breaks and repeat instability.

  11. The repeatability of an intraoral dental colorimeter.

    Science.gov (United States)

    Tung, Francis F; Goldstein, Gary R; Jang, Sungkoo; Hittelman, Eugene

    2002-12-01

    Characterizing and reproducing color remain one of the most challenging aspects of dentistry. A relatively new intraoral colorimeter measures the color of natural teeth and metal-ceramic restorations and prints out a color recipe for the Vintage Halo Porcelain System. The reliability of the colorimeter is unknown. The purpose of this study was to evaluate the reliability of a contact dental colorimeter and to correlate the shade registered by the colorimeter with the shade selected by experienced clinicians. In part I of the study, 2 examiners (A and B) took 2 colorimeter measurements from the maxillary right central incisors of 11 subjects. The examiners were blinded to their own data and those of other investigators. The readings were repeated 3 weeks later with the same protocol. The Cronbach alpha reliability coefficient was used to analyze the collected data. In part II of the study, 2 experienced clinicians (examiners D and E) selected a shade from the classic Vita Lumin Vacuum shade guide for the maxillary right central incisors of the same 11 subjects. The clinicians were blinded to each other's selections and the colorimeter readings. It should be noted that the manufacturer of the colorimeter uses the terms shade, value, and hue to represent chroma, value, and hue, respectively, as defined in the Glossary of Prosthodontic Terms (J Prosthet Dent 1999;81:39-110). The reliability analysis results for each of the combined trials for shade, value, and hue were all >.94. The interexaminer reliability alpha values were >.9 for shade and value and.64 to.74 for hue. The interexaminer alpha represented the value range of each of 4 measurements. The intraexaminer reliability alpha values for shade, value, and hue were.99,.95, and.96 for examiner A and.99,.93, and.97 for examiner B, respectively. In part II of the study, the colorimeter agreed with itself 82% of the time, whereas clinicians agreed with each other on the selected shade 73% of the time. Selections made

  12. Cardiorespiratory Coordination in Repeated Maximal Exercise

    Directory of Open Access Journals (Sweden)

    Sergi Garcia-Retortillo

    2017-06-01

    Full Text Available Increases in cardiorespiratory coordination (CRC after training with no differences in performance and physiological variables have recently been reported using a principal component analysis approach. However, no research has yet evaluated the short-term effects of exercise on CRC. The aim of this study was to delineate the behavior of CRC under different physiological initial conditions produced by repeated maximal exercises. Fifteen participants performed 2 consecutive graded and maximal cycling tests. Test 1 was performed without any previous exercise, and Test 2 6 min after Test 1. Both tests started at 0 W and the workload was increased by 25 W/min in males and 20 W/min in females, until they were not able to maintain the prescribed cycling frequency of 70 rpm for more than 5 consecutive seconds. A principal component (PC analysis of selected cardiovascular and cardiorespiratory variables (expired fraction of O2, expired fraction of CO2, ventilation, systolic blood pressure, diastolic blood pressure, and heart rate was performed to evaluate the CRC defined by the number of PCs in both tests. In order to quantify the degree of coordination, the information entropy was calculated and the eigenvalues of the first PC (PC1 were compared between tests. Although no significant differences were found between the tests with respect to the performed maximal workload (Wmax, maximal oxygen consumption (VO2 max, or ventilatory threshold (VT, an increase in the number of PCs and/or a decrease of eigenvalues of PC1 (t = 2.95; p = 0.01; d = 1.08 was found in Test 2 compared to Test 1. Moreover, entropy was significantly higher (Z = 2.33; p = 0.02; d = 1.43 in the last test. In conclusion, despite the fact that no significant differences were observed in the conventionally explored maximal performance and physiological variables (Wmax, VO2 max, and VT between tests, a reduction of CRC was observed in Test 2. These results emphasize the interest of CRC

  13. Repeatability study of replicate crash tests: A signal analysis approach.

    Science.gov (United States)

    Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

    2017-10-03

    To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

  14. Notas de Ixodologia: II - uma nova espécie do gênero Amblyomma e uma nova espécie do gênero Ixodes (Acari Ixodidae

    Directory of Open Access Journals (Sweden)

    Flavio da Fonseca

    1952-03-01

    Full Text Available A new tick, Amblyomma parkeri, n. sp., is described as a parasite of Coendu sp. from S. Paulo, Brazil. Female holotype, nymph and larva are described (Figs. 2 e 3. The n. sp. differs completly from Koch's species Amblyomma longirostre, the common parasite of the Erethizotidae. Standard data for measures of the female dorsal scutum ixodidae are proposed as follows (fig. 1: PA = Antero-posterior; PB = Postero-basal; PM = Postero-median; TT = Transversal; OO = Inter-ocular; OT= Occulo-transversal; SS = Inter-scapular; CC = Cervical; PT = Postero-transversal; ST = Scapulo-transversal; NPT = Normal to the postero-transversal; NST = Normal to the scapulo-transversal. In the female holotype the standard data are as follows: PA = 2.00 mm; PB = 2.26 mm; PM = 1.10 mm; TT = 2.20 mm; OO = 2.26 mm; SS = 0,84 mm; CC = 0.63 mm; SC = 0.12 mm; NPT = 0.20mm; STN = 0.1 mm. Peritrema 0.80 x 0.42 mm with a narrow postero-internal angle and a large, elongated macula. Coxa I with two short spines and all other coxae with only one shorter spine, shortest in coxa IV. Hypostoma spatulated with formula 3/3. Gnathosoma 1.42 mm long and basis 0.63 mm long by 0.84 greatest wide. Palpi with smoth external surface, 1.00 mm long. Type lot No. 4458 from Cotia, S. Paulo, Brazil; in the acarological collection of the Escola Paulista de Medicina, S. Paulo. Ixodes didelphidis, n. sp., differing from Ixodes loricatus Neumann by the shape of the peritremata (figs. 4 a 5 of the male and female and by the number of the punctations in this organ is described form Didelphidae, Muridae and Cavidae. Twenty eight lots were obtained from Anápolis, Goiás, Brasil, where I. loricatus is subtituded by the n. sp. under description. Comparison with NEUMANN'S types of I. loricatus was possible through the courtesy of Prof. A. BRIZARD from Toulouse, who kindly loaned NEUMANN'S material. Female cotypes N° 40 and male allotype N° 531 in the Collection of Ixodidae of the Oswaldo Cruz Institute.

  15. Comparative efficacy of a new spot-on combination product containing selamectin and sarolaner (Stronghold®Plus) versus fluralaner (Bravecto®) against induced infestations with Ixodes ricinus ticks on cats.

    Science.gov (United States)

    Geurden, Thomas; Borowski, Stasia; Wozniakiewicz, Magda; King, Vickie; Fourie, Josephus; Liebenberg, Julian

    2017-06-29

    Ticks are increasingly reported on cats worldwide, with Ixodes ricinus being a relevant species across Europe and in near by areas of North Africa and the Middle East. Yet there are few acaracidal products with proven efficacy approved for use in cats. The objective of this study was to compare the efficacy of a new spot-on formulation containing selamectin and sarolaner with a topical application of fluralaner (Bravecto®) against Ixodes ricinus ticks on cats. To that end, twenty-four (24) cats were randomly allocated to one of three treatment groups. The cats in the control group remained untreated. Cats in group 2 were treated with selamectin/sarolaner (Stronghold®Plus; Zoetis) at the minimum recommended dose of 1.0 mg/kg sarolaner and 6.0 mg/kg selamectin on Days 0, 30 and 60. The cats in group 3 received a fluralaner treatment (Bravecto®spot-on solution for cats, MSD) at the minimum recommended dose of 40.0 mg/kg on Day 0. Cats were infested with 50 (± 4) viable, adult, unfed I. ricinus ticks on Days 26, 54, 82 and 89 and ticks were removed for counting 48 h (± 2 h) later. Three monthly treatments with selamectin/sarolaner provided high and consistent efficacy against I. ricinus for the entire duration of the study period. In contrast, the efficacy of fluralaner declined in the second month after treatment and was below the efficacy threshold of 90% on Days 56, 84 and 91. The percentage efficacy against I. ricinus was numerically higher in the selemectin/sarolaner treated group than in the fluralaner-treated group on Days 56, 84 and 91. Furthermore, greasiness and spiking of the hair, as well as white deposits were frequently observed in the fluralaner-treated cats. The results of the present study confirm the high and consistent efficacy of a new spot-on combination product containing selamectin and sarolaner against I. ricinus in cats, and indicate a decline in fluralaner efficacy during the 91 day period after treatment.

  16. Repeat photography as a tool for detecting and monitoring historical ...

    African Journals Online (AJOL)

    Repeat photography was used to illustrate long-term changes occurring in coastal habitats in the Western Cape, South Africa. Hi storic images were sourced from books and theses, the public and subject specialists, and repeat photographs were then taken from the same perspectives. Visible changes could be categorised ...

  17. Towards accurate de novo assembly for genomes with repeats

    NARCIS (Netherlands)

    Bucur, Doina

    2017-01-01

    De novo genome assemblers designed for short k-mer length or using short raw reads are unlikely to recover complex features of the underlying genome, such as repeats hundreds of bases long. We implement a stochastic machine-learning method which obtains accurate assemblies with repeats and

  18. Analysis of CR1 Repeats in the Zebra Finch Genome

    Directory of Open Access Journals (Sweden)

    George E. Liu

    2013-06-01

    Full Text Available Most bird species have smaller genomes and fewer repeats than mammals. Chicken Repeat 1 (CR1 repeat is one of the most abundant families of repeats, ranging from ~133,000 to ~187,000 copies accounting for ~50 to ~80% of the interspersed repeats in the zebra finch and chicken genomes, respectively. CR1 repeats are believed to have arisen from the retrotransposition of a small number of master elements, which gave rise to multiple CR1 subfamilies in the chicken. In this study, we performed a global assessment of the divergence distributions, phylogenies, and consensus sequences of CR1 repeats in the zebra finch genome. We identified and validated 34 CR1 subfamilies and further analyzed the correlation between these subfamilies. We also discovered 4 novel lineage-specific CR1 subfamilies in the zebra finch when compared to the chicken genome. We built various evolutionary trees of these subfamilies and concluded that CR1 repeats may play an important role in reshaping the structure of bird genomes.

  19. The Effects of Repeated Experience on Children's Suggestibility.

    Science.gov (United States)

    Powell, Martine B.; Roberts, Kim P.; Ceci, Stephen J.; Hembrooke, Helene

    1999-01-01

    Examined effect of suggestive questions on 3- to 5-year-olds' and 6- to 8-year-olds' recall of the final occurrence of repeated event. Found that relative to reports of children experiencing single occurrence, reports about fixed items of repeated events were less contaminated by false suggestions. Children's age and delay of interview were…

  20. Impact of Inclusion or Exclusion of Repeaters on Test Equating

    Science.gov (United States)

    Puhan, Gautam

    2011-01-01

    This study examined the effect of including or excluding repeaters on the equating process and results. New forms of two tests were equated to their respective old forms using either all examinees or only the first timer examinees in the new form sample. Results showed that for both tests used in this study, including or excluding repeaters in the…

  1. Characteristics of persons with repeat syphilis - Idaho, 2011-2015.

    Science.gov (United States)

    Kassem, Ahmed M; Bartschi, Jared; Carter, Kris K

    2018-03-14

    During 2011-2015 in Idaho, 14 (7%) of 193 persons with early syphilis had repeat syphilis. Persons with repeat infections were more likely to have had secondary or early latent syphilis (P = 0.037) and be infected with HIV (P < 0.001) compared with those having one infection.

  2. Trinucleotide repeat microsatellite markers for Black Poplar (Populus nigra L.)

    NARCIS (Netherlands)

    Smulders, M.J.M.; Schoot, van der J.; Arens, P.; Vosman, B.

    2001-01-01

    Using an enrichment procedure, we have cloned microsatellite repeats from black poplar (Populus nigra L.) and developed primers for microsatellite marker analysis. Ten primer pairs, mostly for trinucleotide repeats, produced polymorphic fragments in P. nigra. Some of them also showed amplification

  3. Simple sequence repeat marker development and genetic mapping ...

    Indian Academy of Sciences (India)

    polymorphic SSR (simple sequence repeats) markers from libraries enriched for GA, CAA and AAT repeats, as well as 6 ... ers for quinoa was the development of a genetic linkage map ...... Weber J. L. 1990 Informativeness of human (dC-dA)n.

  4. Ocular surface sensitivity repeatability with Cochet-Bonnet esthesiometer.

    Science.gov (United States)

    Chao, Cecilia; Stapleton, Fiona; Badarudin, Ezailina; Golebiowski, Blanka

    2015-02-01

    To determine the repeatability of ocular surface threshold measurements using the Cochet-Bonnet esthesiometer on the same day and 3 months apart. Two separate studies were conducted to determine the repeatability of ocular surface threshold measurements made on the same day (n = 20 subjects) and 3 months apart (n = 29 subjects). The Cochet-Bonnet esthesiometer was used to measure corneal and inferior conjunctival thresholds using the ascending method of limits. The pressure exerted by the Cochet-Bonnet esthesiometer was determined using an analytical balance, for both the 0.08- and 0.12-mm-diameter filaments. This calibration was then used to convert filament length measurements to pressure. Repeatability was determined using a Bland and Altman analysis. The pressure exerted at each filament length differed between the two filament diameters. The measured pressure also differed from values provided by the manufacturer. Repeatability of threshold measurements at the central cornea was shown to be good, with better repeatability for same-day measurements (coefficient of repeatability [CoR] = ±0.23 g/mm²) than for those 3 months apart (CoR = ±0.52 g/mm²). Threshold measurements at the inferior conjunctiva, in contrast, were poorly repeatable (CoR = ±12.78 g/mm²). Cochet-Bonnet esthesiometry is repeatable when performed on the central cornea on the same day and 3 months apart, but this instrument is not recommended for conjunctival threshold measurements.

  5. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated

  6. Large Polyglutamine Repeats Cause Muscle Degeneration in SCA17 Mice

    Directory of Open Access Journals (Sweden)

    Shanshan Huang

    2015-10-01

    Full Text Available In polyglutamine (polyQ diseases, large polyQ repeats cause juvenile cases with different symptoms than those of adult-onset patients, who carry smaller expanded polyQ repeats. The mechanisms behind the differential pathology mediated by different polyQ repeat lengths remain unknown. By studying knockin mouse models of spinal cerebellar ataxia-17 (SCA17, we found that a large polyQ (105 glutamines in the TATA-box-binding protein (TBP preferentially causes muscle degeneration and reduces the expression of muscle-specific genes. Direct expression of TBP with different polyQ repeats in mouse muscle revealed that muscle degeneration is mediated only by the large polyQ repeats. Different polyQ repeats differentially alter TBP’s interaction with neuronal and muscle-specific transcription factors. As a result, the large polyQ repeat decreases the association of MyoD with TBP and DNA promoters. Our findings suggest that specific alterations in protein interactions by large polyQ repeats may account for the unique pathology in juvenile polyQ diseases.

  7. Large Polyglutamine Repeats Cause Muscle Degeneration in SCA17 Mice

    Science.gov (United States)

    Huang, Shanshan; Yang, Su; Guo, Jifeng; Yan, Sen; Gaertig, Marta A.; Li, Shihua; Li, Xiao-Jiang

    2015-01-01

    SUMMARY In polyglutamine (polyQ) diseases, large polyQ repeats cause juvenile cases with different symptoms than adult-onset patients, who carry smaller expanded polyQ repeats. The mechanisms behind the differential pathology mediated by different polyQ repeat lengths remain unknown. By studying knock-in mouse models of spinal cerebellar ataxia-17 (SCA17), we found that a large polyQ (105 glutamines) in the TATA box-binding protein (TBP) preferentially causes muscle degeneration and reduces the expression of muscle-specific genes. Direct expression of TBP with different polyQ repeats in mouse muscle revealed that muscle degeneration is mediated only by the large polyQ repeats. Different polyQ repeats differentially alter TBP’s interaction with neuronal and muscle-specific transcription factors. As a result, the large polyQ repeat decreases the association of MyoD with TBP and DNA promoters. Our findings suggest that specific alterations in protein interactions by large polyQ repeats may account for the unique pathology in juvenile polyQ diseases. PMID:26387956

  8. Huntingtin gene repeat size variations affect risk of lifetime depression

    DEFF Research Database (Denmark)

    Gardiner, Sarah L.; van Belzen, Martine J.; Boogaard, Merel W.

    2017-01-01

    Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect...

  9. Repeat profile analysis in an x-ray department

    International Nuclear Information System (INIS)

    Bassey, C.E.; Ojo, O.O.; Akpabio, I.

    1991-01-01

    The repeat profile of an x-ray department in a developing country was analysed monthly between July 1989 and June 1990. Results showed an average repeat rate of 3.7% for the period of study. The main causes of film repetition were: equipment fault, 33.9%; radiographer's fault, 27.4%; film fault, 19.3%; processing fault, 10.8% and patient's fault, 8.6%. The average repeat rate in the first 6 months of study reduced by 50% in the last 6 months. This was due to the effectiveness of implementation of corrective actions. The overall repeat rate was found to correlate well with both the equipment fault and radiographer's fault with correlation coefficients, r, of 0.94 and 0.91, respectively. It is expected that a further reduction in the repeat rate will be obtained after the introduction of quality assurance programmes. (author)

  10. Clinical oversight and the avoidance of repeat induced abortion.

    Science.gov (United States)

    Jacovetty, Erica L; Clare, Camille A; Squire, Mary-Beatrice; Kubal, Keshar P; Liou, Sherry; Inchiosa, Mario A

    2018-06-03

    To evaluate the impact of patient counseling, demographics, and contraceptive methods on repeat induced abortion in women attending family planning clinics. A retrospective chart review of repeat induced abortions was performed. The analysis included patients with an initial induced abortion obtained between January 1, 2001, and March 31, 2014, at New York City Health + Hospitals/Metropolitan. The duration of involvement in the family planning program, the use of contraceptive interventions, and 18 patient factors were analyzed for their correlation with the incidence of repeat induced abortions per year of follow-up. A decreased rate of repeat induced abortions was associated with a longer duration of clinical oversight (r 2 =0.449, Pabortions. By determining the patient characteristics that most influence repeat induced abortion rates, providers can best choose the most efficacious method of contraception available. © 2018 International Federation of Gynecology and Obstetrics.

  11. Selection pressure on human STR loci and its relevance in repeat expansion disease

    KAUST Repository

    Shimada, Makoto K.; Sanbonmatsu, Ryoko; Yamaguchi-Kabata, Yumi; Yamasaki, Chisato; Suzuki, Yoshiyuki; Chakraborty, Ranajit; Gojobori, Takashi; Imanishi, Tadashi

    2016-01-01

    Short Tandem Repeats (STRs) comprise repeats of one to several base pairs. Because of the high mutability due to strand slippage during DNA synthesis, rapid evolutionary change in the number of repeating units directly shapes the range of repeat

  12. Genus-specific protein binding to the large clusters of DNA repeats (short regularly spaced repeats) present in Sulfolobus genomes

    DEFF Research Database (Denmark)

    Peng, Xu; Brügger, Kim; Shen, Biao

    2003-01-01

    terminally modified and corresponds to SSO454, an open reading frame of previously unassigned function. It binds specifically to DNA fragments carrying double and single repeat sequences, binding on one side of the repeat structure, and producing an opening of the opposite side of the DNA structure. It also...... recognizes both main families of repeat sequences in S. solfataricus. The recombinant protein, expressed in Escherichia coli, showed the same binding properties to the SRSR repeat as the native one. The SSO454 protein exhibits a tripartite internal repeat structure which yields a good sequence match...... with a helix-turn-helix DNA-binding motif. Although this putative motif is shared by other archaeal proteins, orthologs of SSO454 were only detected in species within the Sulfolobus genus and in the closely related Acidianus genus. We infer that the genus-specific protein induces an opening of the structure...

  13. Environmental stress induces trinucleotide repeat mutagenesis in human cells.

    Science.gov (United States)

    Chatterjee, Nimrat; Lin, Yunfu; Santillan, Beatriz A; Yotnda, Patricia; Wilson, John H

    2015-03-24

    The dynamic mutability of microsatellite repeats is implicated in the modification of gene function and disease phenotype. Studies of the enhanced instability of long trinucleotide repeats (TNRs)-the cause of multiple human diseases-have revealed a remarkable complexity of mutagenic mechanisms. Here, we show that cold, heat, hypoxic, and oxidative stresses induce mutagenesis of a long CAG repeat tract in human cells. We show that stress-response factors mediate the stress-induced mutagenesis (SIM) of CAG repeats. We show further that SIM of CAG repeats does not involve mismatch repair, nucleotide excision repair, or transcription, processes that are known to promote TNR mutagenesis in other pathways of instability. Instead, we find that these stresses stimulate DNA rereplication, increasing the proportion of cells with >4 C-value (C) DNA content. Knockdown of the replication origin-licensing factor CDT1 eliminates both stress-induced rereplication and CAG repeat mutagenesis. In addition, direct induction of rereplication in the absence of stress also increases the proportion of cells with >4C DNA content and promotes repeat mutagenesis. Thus, environmental stress triggers a unique pathway for TNR mutagenesis that likely is mediated by DNA rereplication. This pathway may impact normal cells as they encounter stresses in their environment or during development or abnormal cells as they evolve metastatic potential.

  14. Dental Fear in Children with Repeated Tooth Injuries.

    Science.gov (United States)

    Negovetić Vranić, Dubravka; Ivančić Jokić, Nataša; Bakarčić, Danko; Carek, Andreja; Rotim, Željko; Verzak, Željko

    2016-06-01

    Tooth injuries are serious clinical conditions. Some children experience dental trauma only once, while others are more prone to repeated tooth injuries. Repeated dental trauma occurs in 19.4% to 30% of patients. Pain and dental trauma are the most common reasons for fear and anxiety. The main objective of this study was to investigate how dental trauma, as well as repeated dental trauma affects the occurrence and development of dental fear in children. The study was conducted on a random sample of 147 subjects (88 boys and 59 girls) aged 5-8 and 9-12 years. Subjects in both age groups were divided into subroups without dental trauma, with one dental trauma and with repeated dental trauma. The validated Children’s Fear Survey Schedule – Dental Subscale was used on fear assessment. Results showed that only 12.2% of children without trauma, 33.3% with one trauma and 51.7% with repeated trauma were not afraid of injection. Older children had a significantly lower fear of injections, touch of an unknown person, choking, going to the hospital and people in white uniforms. Dentist was not the cause of fear in 65.5% of patients with repeated trauma. With each repeated injury of teeth, the degree of their fear of dental treatment was lower.

  15. Oxidative stress adaptation with acute, chronic, and repeated stress.

    Science.gov (United States)

    Pickering, Andrew M; Vojtovich, Lesya; Tower, John; A Davies, Kelvin J

    2013-02-01

    Oxidative stress adaptation, or hormesis, is an important mechanism by which cells and organisms respond to, and cope with, environmental and physiological shifts in the level of oxidative stress. Most studies of oxidative stress adaption have been limited to adaptation induced by acute stress. In contrast, many if not most environmental and physiological stresses are either repeated or chronic. In this study we find that both cultured mammalian cells and the fruit fly Drosophila melanogaster are capable of adapting to chronic or repeated stress by upregulating protective systems, such as their proteasomal proteolytic capacity to remove oxidized proteins. Repeated stress adaptation resulted in significant extension of adaptive responses. Repeated stresses must occur at sufficiently long intervals, however (12-h or more for MEF cells and 7 days or more for flies), for adaptation to be successful, and the levels of both repeated and chronic stress must be lower than is optimal for adaptation to acute stress. Regrettably, regimens of adaptation to both repeated and chronic stress that were successful for short-term survival in Drosophila nevertheless also caused significant reductions in life span for the flies. Thus, although both repeated and chronic stress can be tolerated, they may result in a shorter life. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. The risk of exposure to Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Babesia sp. and co-infections in Ixodes ricinus ticks on the territory of Niepołomice forest (southern Poland).

    Science.gov (United States)

    Asman, Marek; Nowak, Magdalena; Cuber, Piotr; Strzelczyk, Joanna; Szilman, Ewa; Szilman, Piotr; Trapp, Gizela; Siuda, Krzysztof; Solarz, Krzysztof; Wiczkowski, Andrzej

    2013-01-01

    Niepołomice Forest is located about 20 kilometers east of Cracow (Malopolska province, southern Poland). Its natural and touristic values, as well as wide range of hosts occurring within indicate this to be an area of high risk of exposure to Ixodes ricinus and tick-borne diseases it transfers. I. ricinus is a common species in Poland and Europe. Its seasonal activity begins in Poland in the early spring, and ends with late autumn. A total number of 129 specimens of I. ricinus was collected by flagging in Niepołomice Forest. DNA was isolated by ammonia method from 30 randomly-selected individuals. PCR was used to detect tick-borne pathogens with primers specific for Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and Babesia sp. Molecular studies confirmed the presence of all three pathogens in I. ricinus. A. phagocytophilum was found in 76.7%, Babesia sp., 60%, B. burgdorferi s. l., in 3.3% of studied ticks. A. phagocytophilum co-infection with Babesia sp., was found in 46.7% of the specimens. A co-infection of all three tested pathogens was recorded in one case (3.3%). In Poland the problem of tick-borne diseases is a growing issue, therefore people residing in southern Polish touristic areas should be informed about the prevention and protection against ticks.

  17. Infections and mixed infections with the selected species of Borrelia burgdorferi sensu lato complex in Ixodes ricinus ticks collected in eastern Poland: a significant increase in the course of 5 years.

    Science.gov (United States)

    Wójcik-Fatla, Angelina; Zając, Violetta; Sawczyn, Anna; Sroka, Jacek; Cisak, Ewa; Dutkiewicz, Jacek

    2016-02-01

    In the years 2008-2009 and 2013-2014, 1620 and 1500 questing Ixodes ricinus ticks, respectively, were examined on the territory of the Lublin province (eastern Poland). The presence of three pathogenic species causing Lyme disease was investigated: Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii. The proportion of I. ricinus ticks infected with B. burgdorferi sensu lato showed a highly significant increase between 2008-2009 and 2013-2014, from 6.0 to 15.3%. A significant increase was noted with regard to all types of infections with individual species: single (4.7-7.8%), dual (1.2-6.6%), and triple (0.1-0.9%). When expressed as the percent of all infections, the frequency of mixed infections increased from 21.4 to 49.2%. Statistical analysis performed with two methods (by calculating of odds ratios and by Fisher's exact test) showed that the frequencies of mixed infections in most cases proved to be significantly greater than expected. The strongest associations were found between B. burgdorferi s. s. and B. afzelii, and between B. burgdorferi s. s. and B. garinii. They appeared to be highly significant (P eastern Poland, and dramatic enhancement of mixed infections with individual species, which may result in mixed infections of humans and exacerbation of the clinical course of Lyme disease cases on the studied area.

  18. ACCA phosphopeptide recognition by the BRCT repeats of BRCA1.

    Science.gov (United States)

    Ray, Hind; Moreau, Karen; Dizin, Eva; Callebaut, Isabelle; Venezia, Nicole Dalla

    2006-06-16

    The tumour suppressor gene BRCA1 encodes a 220 kDa protein that participates in multiple cellular processes. The BRCA1 protein contains a tandem of two BRCT repeats at its carboxy-terminal region. The majority of disease-associated BRCA1 mutations affect this region and provide to the BRCT repeats a central role in the BRCA1 tumour suppressor function. The BRCT repeats have been shown to mediate phospho-dependant protein-protein interactions. They recognize phosphorylated peptides using a recognition groove that spans both BRCT repeats. We previously identified an interaction between the tandem of BRCA1 BRCT repeats and ACCA, which was disrupted by germ line BRCA1 mutations that affect the BRCT repeats. We recently showed that BRCA1 modulates ACCA activity through its phospho-dependent binding to ACCA. To delineate the region of ACCA that is crucial for the regulation of its activity by BRCA1, we searched for potential phosphorylation sites in the ACCA sequence that might be recognized by the BRCA1 BRCT repeats. Using sequence analysis and structure modelling, we proposed the Ser1263 residue as the most favourable candidate among six residues, for recognition by the BRCA1 BRCT repeats. Using experimental approaches, such as GST pull-down assay with Bosc cells, we clearly showed that phosphorylation of only Ser1263 was essential for the interaction of ACCA with the BRCT repeats. We finally demonstrated by immunoprecipitation of ACCA in cells, that the whole BRCA1 protein interacts with ACCA when phosphorylated on Ser1263.

  19. Identification, variation and transcription of pneumococcal repeat sequences

    Science.gov (United States)

    2011-01-01

    Background Small interspersed repeats are commonly found in many bacterial chromosomes. Two families of repeats (BOX and RUP) have previously been identified in the genome of Streptococcus pneumoniae, a nasopharyngeal commensal and respiratory pathogen of humans. However, little is known about the role they play in pneumococcal genetics. Results Analysis of the genome of S. pneumoniae ATCC 700669 revealed the presence of a third repeat family, which we have named SPRITE. All three repeats are present at a reduced density in the genome of the closely related species S. mitis. However, they are almost entirely absent from all other streptococci, although a set of elements related to the pneumococcal BOX repeat was identified in the zoonotic pathogen S. suis. In conjunction with information regarding their distribution within the pneumococcal chromosome, this suggests that it is unlikely that these repeats are specialised sequences performing a particular role for the host, but rather that they constitute parasitic elements. However, comparing insertion sites between pneumococcal sequences indicates that they appear to transpose at a much lower rate than IS elements. Some large BOX elements in S. pneumoniae were found to encode open reading frames on both strands of the genome, whilst another was found to form a composite RNA structure with two T box riboswitches. In multiple cases, such BOX elements were demonstrated as being expressed using directional RNA-seq and RT-PCR. Conclusions BOX, RUP and SPRITE repeats appear to have proliferated extensively throughout the pneumococcal chromosome during the species' past, but novel insertions are currently occurring at a relatively slow rate. Through their extensive secondary structures, they seem likely to affect the expression of genes with which they are co-transcribed. Software for annotation of these repeats is freely available from ftp://ftp.sanger.ac.uk/pub/pathogens/strep_repeats/. PMID:21333003

  20. Reproducibility and Reliability of Repeated Quantitative Fluorescence Angiography

    DEFF Research Database (Denmark)

    Nerup, Nikolaj; Knudsen, Kristine Bach Korsholm; Ambrus, Rikard

    2017-01-01

    INTRODUCTION: When using fluorescence angiography (FA) in perioperative perfusion assessment, repeated measures with re-injections of fluorescent dye (ICG) may be required. However, repeated injections may cause saturation of dye in the tissue, exceeding the limit of fluorescence intensity...... that the camera can detect. As the emission of fluorescence is dependent of the excitatory light intensity, reduction of this may solve the problem. The aim of the present study was to investigate the reproducibility and reliability of repeated quantitative FA during a reduction of excitatory light....

  1. Pension Reform Act 2004 and its Controversies: Repeating or ...

    African Journals Online (AJOL)

    Pension Reform Act 2004 and its Controversies: Repeating or Learning from Past Mistakes? ... Journal of Research in National Development ... and discusses how the present pension reform will affect active employees when they retire.

  2. A study on the repeatability of ultrasonic testing data

    International Nuclear Information System (INIS)

    Yoshimura, Seiichi; Fukumoto, Hiroshi

    1980-01-01

    Reliability improvement of ultrasonic testing data is strongly desired in ultrasonic testing working of nuclear power plants. This paper deals with the problems of the testing by the manual and the remote control apparatus, and with the factors which influence the repeatability of ultrasonic testing data. Following results are found in it. (1) In the testing by the manual, working time and posture influence the repeatability of testing data. (2) Glycerin in suitable for the couplant in the respect of the repeatability of testing data. In the case of using machine oil, the pressure to the probe necessitates to be over 0.2 kg/cm 2 . (3) In the testing by the remote control apparatus, working time, working environment and defect position does not influence the repeatability of testing data. (author)

  3. Repeat Assessed Values Model for Housing Price Index

    Directory of Open Access Journals (Sweden)

    Carini Manuela

    2017-12-01

    Full Text Available This study proposes an innovative methodology, named Repeat Appraised Price Model (RAV, useful for determining the price index numbers for real estate markets and the corresponding index numbers of hedonic prices of main real estate characteristics in the case of a lack of data. The methodological approach proposed in this paper aims to appraise the time series of price index numbers. It integrates the principles of the method of repeat sales with the peculiarities of the Hedonic Price Method, overcoming the problem of an almost total absence of repeat sales for the same property in a given time range; on the other hand, the technique aims to overcome the limitation of the repeat sales technique concerning the inability to take into account the characteristics of individual properties.

  4. Repeated morphine treatment influences operant and spatial learning differentially

    Institute of Scientific and Technical Information of China (English)

    Mei-Na WANG; Zhi-Fang DONG; Jun CAO; Lin XU

    2006-01-01

    Objective To investigate whether repeated morphine exposure or prolonged withdrawal could influence operant and spatial learning differentially. Methods Animals were chronically treated with morphine or subjected to morphine withdrawal. Then, they were subjected to two kinds of learning: operant conditioning and spatial learning.Results The acquisition of both simple appetitive and cued operant learning was impaired after repeated morphine treatment. Withdrawal for 5 weeks alleviated the impairments. Single morphine exposure disrupted the retrieval of operant memory but had no effect on rats after 5-week withdrawal. Contrarily, neither chronic morphine exposure nor 5-week withdrawal influenced spatial learning task of the Morris water maze. Nevertheless, the retrieval of spatial memory was impaired by repeated morphine exposure but not by 5-week withdrawal. Conclusion These observations suggest that repeated morphine exposure can influence different types of learning at different aspects, implicating that the formation of opiate addiction may usurp memory mechanisms differentially.

  5. P-Scan provides accuracy and repeatability in ultrasonics

    International Nuclear Information System (INIS)

    Keys, R.L.

    1987-01-01

    The P-Scan (Projection image scanning technique) is an automated ultrasonic inspection technique, developed to overcome the problems with accuracy and repeatability experienced with manual ultrasonic systems. The equipment and its applications are described. (author)

  6. simple sequence repeat (SSR) markers in genetic analysis of

    African Journals Online (AJOL)

    Yomi

    2012-08-28

    1998). Cross- species amplification of soybean (Glycine max) simple sequence repeats (SSRs) within the genus and other legume genera: implications for the transferability of SSRs in plants. Mol. Biol. Evol. 15:1275-1287.

  7. Advantages and disadvantages : longitudinal vs. repeated cross-section surveys

    Science.gov (United States)

    1996-06-20

    The benefits of a longitudinal analysis over a repeated cross-sectional study include increased statistical power and the capability to estimate a greater range of conditional probabilities. With the Puget Sound Transportation Panel (PSTP), and any s...

  8. One way quantum repeaters with quantum Reed-Solomon codes

    OpenAIRE

    Muralidharan, Sreraman; Zou, Chang-Ling; Li, Linshu; Jiang, Liang

    2018-01-01

    We show that quantum Reed-Solomon codes constructed from classical Reed-Solomon codes can approach the capacity on the quantum erasure channel of $d$-level systems for large dimension $d$. We study the performance of one-way quantum repeaters with these codes and obtain a significant improvement in key generation rate compared to previously investigated encoding schemes with quantum parity codes and quantum polynomial codes. We also compare the three generation of quantum repeaters using quan...

  9. Learning, Teaching, and Turn Taking in the Repeated Assignment Game

    OpenAIRE

    Timothy N. Cason; Sau-Him Paul Lau; Vai-Lam Mui

    2011-01-01

    History-dependent strategies are often used to support cooperation in repeated game models. Using the indefinitely repeated common-pool resource assignment game and a perfect stranger experimental design, this paper reports novel evidence that players who have successfully used an efficiency-enhancing turn-taking strategy will teach other players in subsequent supergames to adopt this strategy. We find that subjects engage in turn taking frequently in both the Low Conflict and the High Confli...

  10. Relationship between quantum repeating devices and quantum seals

    International Nuclear Information System (INIS)

    He Guangping

    2009-01-01

    It is revealed that quantum repeating devices and quantum seals have a very close relationship, thus the theory in one field can be applied to the other. Consequently, it is shown that the fidelity bounds and optimality of quantum repeating devices for decoding quantum information can be violated when they are used for decoding classical information from quantum states and the security bounds for protocols sealing quantum data exist.

  11. Repeatability and reproducibility of decisions by latent fingerprint examiners.

    Directory of Open Access Journals (Sweden)

    Bradford T Ulery

    Full Text Available The interpretation of forensic fingerprint evidence relies on the expertise of latent print examiners. We tested latent print examiners on the extent to which they reached consistent decisions. This study assessed intra-examiner repeatability by retesting 72 examiners on comparisons of latent and exemplar fingerprints, after an interval of approximately seven months; each examiner was reassigned 25 image pairs for comparison, out of total pool of 744 image pairs. We compare these repeatability results with reproducibility (inter-examiner results derived from our previous study. Examiners repeated 89.1% of their individualization decisions, and 90.1% of their exclusion decisions; most of the changed decisions resulted in inconclusive decisions. Repeatability of comparison decisions (individualization, exclusion, inconclusive was 90.0% for mated pairs, and 85.9% for nonmated pairs. Repeatability and reproducibility were notably lower for comparisons assessed by the examiners as "difficult" than for "easy" or "moderate" comparisons, indicating that examiners' assessments of difficulty may be useful for quality assurance. No false positive errors were repeated (n = 4; 30% of false negative errors were repeated. One percent of latent value decisions were completely reversed (no value even for exclusion vs. of value for individualization. Most of the inter- and intra-examiner variability concerned whether the examiners considered the information available to be sufficient to reach a conclusion; this variability was concentrated on specific image pairs such that repeatability and reproducibility were very high on some comparisons and very low on others. Much of the variability appears to be due to making categorical decisions in borderline cases.

  12. Evaluation of Mammalian Interspersed Repeats to investigate the goat genome

    Directory of Open Access Journals (Sweden)

    P. Mariani

    2010-01-01

    Full Text Available Among the repeated sequences present in most eukaryotic genomes, SINEs (Short Interspersed Nuclear Elements are widely used to investigate evolution in the mammalian order (Buchanan et al., 1999. One family of these repetitive sequences, the MIR (Mammalian Interspersed Repeats; Jurka et al., 1995, is ubiquitous in all mammals.MIR elements are tRNA-derived SINEs and are identifiable by a conserved core region of about 70 nucleotides.

  13. A General Model for Repeated Audit Controls Using Monotone Subsampling

    OpenAIRE

    Raats, V.M.; van der Genugten, B.B.; Moors, J.J.A.

    2002-01-01

    In categorical repeated audit controls, fallible auditors classify sample elements in order to estimate the population fraction of elements in certain categories.To take possible misclassifications into account, subsequent checks are performed with a decreasing number of observations.In this paper a model is presented for a general repeated audit control system, where k subsequent auditors classify elements into r categories.Two different sub-sampling procedures will be discussed, named 'stra...

  14. Quantum key distribution with two-segment quantum repeaters

    Energy Technology Data Exchange (ETDEWEB)

    Kampermann, Hermann; Abruzzo, Silvestre; Bruss, Dagmar [Theoretische Physik III, Heinrich-Heine-Universitaet Duesseldorf (Germany)

    2014-07-01

    Quantum repeaters represent one possible way to achieve long-distance quantum key distribution. One way of improving the repeater rate and decreasing the memory coherence time is the usage of multiplexing. Motivated by the experimental fact that long-range connections are practically demanding, we extend the analysis of the quantum repeater multiplexing protocol to the case of short-range connections. We derive formulas for the repeater rate and we show that short-range connections lead to most of the benefits of a full-range multiplexing protocol. A less demanding QKD-protocol without quantum memories was recently introduced by Lo et al. We generalize this measurement-device-independent quantum key Distribution protocol to the scenario where the repeater Station contains also heralded quantum memories. We assume either single-photon sources or weak coherent pulse sources plus decay states. We show that it is possible to significantly outperform the original proposal, even in presence of decoherence of the quantum memory. We give formulas in terms of device imperfections i.e., the quantum bit error rate and the repeater rate.

  15. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    International Nuclear Information System (INIS)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-01-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of [ 3 H]Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in [14C]iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress [an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures], although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results

  16. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  17. Two tandemly repeated telomere-associated sequences in Nicotiana plumbaginifolia.

    Science.gov (United States)

    Chen, C M; Wang, C T; Wang, C J; Ho, C H; Kao, Y Y; Chen, C C

    1997-12-01

    Two tandemly repeated telomere-associated sequences, NP3R and NP4R, have been isolated from Nicotiana plumbaginifolia. The length of a repeating unit for NP3R and NP4R is 165 and 180 nucleotides respectively. The abundance of NP3R, NP4R and telomeric repeats is, respectively, 8.4 x 10(4), 6 x 10(3) and 1.5 x 10(6) copies per haploid genome of N. plumbaginifolia. Fluorescence in situ hybridization revealed that NP3R is located at the ends and/or in interstitial regions of all 10 chromosomes and NP4R on the terminal regions of three chromosomes in the haploid genome of N. plumbaginifolia. Sequence homology search revealed that not only are NP3R and NP4R homologous to HRS60 and GRS, respectively, two tandem repeats isolated from N. tabacum, but that NP3R and NP4R are also related to each other, suggesting that they originated from a common ancestral sequence. The role of these repeated sequences in chromosome healing is discussed based on the observation that two to three copies of a telomere-similar sequence were present in each repeating unit of NP3R and NP4R.

  18. Stable Transmission of Borrelia burgdorferi Sensu Stricto on the Outer Banks of North Carolina.

    Science.gov (United States)

    Levine, J F; Apperson, C S; Levin, M; Kelly, T R; Kakumanu, M L; Ponnusamy, L; Sutton, H; Salger, S A; Caldwell, J M; Szempruch, A J

    2017-08-01

    The spirochaete (Borrelia burgdorferi) associated with Lyme disease was detected in questing ticks and rodents during a period of 18 years, 1991-2009, at five locations on the Outer Banks of North Carolina. The black-legged tick (Ixodes scapularis) was collected at varied intervals between 1991 and 2009 and examined for B. burgdorferi. The white-footed mouse (Peromyscus leucopus), house mouse (Mus musculus) marsh rice rat (Oryzomys palustris), marsh rabbit (Sylvilagus palustris), eastern cottontail (Sylvilagus floridanus) and six-lined racerunner (Cnemidophorus sexlineatus) were live-trapped, and their tissues cultured to isolate spirochaetes. Borrelia burgdorferi isolates were obtained from questing adult I. scapularis and engorged I. scapularis removed from P. leucopus, O. palustris and S. floridanus. The prevalence of B. burgdorferi infection was variable at different times and sites ranging from 7 to 14% of examined questing I. scapularis. Mitochondrial (16S) rRNA gene phylogenetic analysis from 65 adult I. scapularis identified 12 haplotypes in two major clades. Nine haplotypes were associated with northern/Midwestern I. scapularis populations and three with southern I. scapularis populations. Sixteen isolates obtained from tick hosts in 2005 were confirmed to be B. burgdorferi by amplifying and sequencing of 16S rRNA and 5S-23S intergenic spacer fragments. The sequences had 98-99% identity to B. burgdorferi sensu stricto strains B31, JD1 and M11p. Taken together, these studies indicate that B. burgdorferi sensu stricto is endemic in questing I. scapularis and mammalian tick hosts on the Outer Banks of North Carolina. © 2016 Blackwell Verlag GmbH.

  19. The Tick Salivary Protein Sialostatin L Inhibits the Th9-Derived Production of the Asthma-Promoting Cytokine IL-9 and Is Effective in the Prevention of Experimental Asthma

    Czech Academy of Sciences Publication Activity Database

    Horká, Helena; Staudt, V.; Klein, M.; Taube, Ch.; Reuter, S.; Dehzad, N.; Andersen, J. F.; Kopecký, Jan; Schild, H.; Kotsyfakis, Michalis; Hoffmann, M.; Gerlitzki, B.; Stassen, M.; Bopp, T.; Schmitt, E.

    2012-01-01

    Roč. 188, č. 6 (2012), s. 2669-2676 ISSN 0022-1767 R&D Projects: GA ČR GCP302/11/J029; GA MŠk(CZ) LC06009 Institutional support: RVO:60077344 Keywords : experimental asthma * airway hyperresponsiveness * eosinophilia * interleukin-9 * Th9 cells * Sialostatin L * therapeutic * Ixodes scapularis * cysteine protease inhibitor * tick saliva Subject RIV: EC - Immunology Impact factor: 5.520, year: 2012

  20. Germ-line CAG repeat instability causes extreme CAG repeat expansion with infantile-onset spinocerebellar ataxia type 2

    DEFF Research Database (Denmark)

    Vinther-Jensen, Tua; Ek, Jakob; Duno, Morten

    2013-01-01

    The spinocerebellar ataxias (SCA) are a genetically and clinically heterogeneous group of diseases, characterized by dominant inheritance, progressive cerebellar ataxia and diverse extracerebellar symptoms. A subgroup of the ataxias is caused by unstable CAG-repeat expansions in their respective ...... of paternal germ-line repeat sequence instability of the expanded SCA2 locus.European Journal of Human Genetics advance online publication, 10 October 2012; doi:10.1038/ejhg.2012.231....

  1. Reject/repeat analysis and the effect prior film viewing has on a department's reject/repeat rate

    International Nuclear Information System (INIS)

    Clark, P.A.; Hogg, P.

    2003-01-01

    Purpose: Achieving cost-effectiveness within the NHS is an old initiative but one that has again been highlighted by recent government policies (The New NHS-Modern and Dependable, Stationary Office, London, 1997). It has been reiterated that it is the responsibility of individual Trusts to devise means to provide such a service. Reject/repeat analyses have long been the primary tool used to assess the cost-effectiveness of radiography departments (Quality Assurance in Diagnostic Radiology, WHO, Geneva, 1982). This research paper examines an in-house initiative (viewing patients' previous films) commonly employed in other Health Trusts in order to reduce departmental repeat/reject rates. Method: Three hundred orthopaedic patients with hip, knee and ankle prostheses were included in a reject/repeat analysis. The aim was to investigate whether or not viewing patient's previous relevant radiographs would be advantageous to the practicing radiographer. This was done through an audit cycle consisting of two audit periods each lasting for 3 months. The primary audit period recorded the baseline repeat/reject rate, with the secondary audit period recording the repeat/reject rate under an experimental condition of viewing the relevant radiographs. Results: The baseline audit revealed repeat rates of 33% in orthopaedic patients with hip, knee and ankle prostheses. The availability of prior film viewing to the radiographer reduced this repeat rate to 10.6%. Conclusion: Prior film viewing dramatically reduced the department's repeat/reject rate by 22.4%. This provides scope for significant patient dose reductions as well as reducing departmental film expenses. This is an underestimated initiative and should be used appropriately in routine clinical practice

  2. Huntingtin gene repeat size variations affect risk of lifetime depression.

    Science.gov (United States)

    Gardiner, Sarah L; van Belzen, Martine J; Boogaard, Merel W; van Roon-Mom, Willeke M C; Rozing, Maarten P; van Hemert, Albert M; Smit, Johannes H; Beekman, Aartjan T F; van Grootheest, Gerard; Schoevers, Robert A; Oude Voshaar, Richard C; Roos, Raymund A C; Comijs, Hannie C; Penninx, Brenda W J H; van der Mast, Roos C; Aziz, N Ahmad

    2017-12-11

    Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect depression risk in the general population. Using binary logistic regression, we assessed the association between HTT CAG repeat size and depression risk in two well-characterized Dutch cohorts─the Netherlands Study of Depression and Anxiety and the Netherlands Study of Depression in Older Persons─including 2165 depressed and 1058 non-depressed persons. In both cohorts, separately as well as combined, there was a significant non-linear association between the risk of lifetime depression and HTT CAG repeat size in which both relatively short and relatively large alleles were associated with an increased risk of depression (β = -0.292 and β = 0.006 for the linear and the quadratic term, respectively; both P < 0.01 after adjustment for the effects of sex, age, and education level). The odds of lifetime depression were lowest in persons with a HTT CAG repeat size of 21 (odds ratio: 0.71, 95% confidence interval: 0.52 to 0.98) compared to the average odds in the total cohort. In conclusion, lifetime depression risk was higher with both relatively short and relatively large HTT CAG repeat sizes in the normal range. Our study provides important proof-of-principle that repeat polymorphisms can act as hitherto unappreciated but complex genetic modifiers of depression.

  3. Intra-examiner repeatability and agreement in accommodative response measurements.

    Science.gov (United States)

    Antona, B; Sanchez, I; Barrio, A; Barra, F; Gonzalez, E

    2009-11-01

    Clinical measurement of the accommodative response (AR) identifies the focusing plane of a subject with respect to the accommodative target. To establish whether a significant change in AR has occurred, it is important to determine the repeatability of this measurement. This study had two aims: First, to determine the intraexaminer repeatability of AR measurements using four clinical methods: Nott retinoscopy, monocular estimate method (MEM) retinoscopy, binocular crossed cylinder test (BCC) and near autorefractometry. Second, to study the level of agreement between AR measurements obtained with the different methods. The AR of the right eye at one accommodative demand of 2.50 D (40 cm) was measured on two separate occasions in 61 visually normal subjects of mean age 19.7 years (range 18-32 years). The intraexaminer repeatability of the tests, and agreement between them, were estimated by the Bland-Altman method. We determined mean differences (MD) and the 95% limits of agreement [coefficient of repeatability (COR) and coefficient of agreement (COA)]. Nott retinoscopy and BCC offered the best repeatability, showing the lowest MD and narrowest 95% interval of agreement (Nott: -0.10 +/- 0.66 D, BCC: -0.05 +/- 0.75 D). The 95% limits of agreement for the four techniques were similar (COA = +/- 0.92 to +/-1.00 D) yet clinically significant, according to the expected values of the AR. The two dynamic retinoscopy techniques (Nott and MEM) had a better agreement (COA = +/-0.64 D) although this COA must be interpreted in the context of the low MEM repeatability (COR = +/-0.98 D). The best method of assessing AR was Nott retinoscopy. The BCC technique was also repeatable, and both are recommended as suitable methods for clinical use. Despite better agreement between MEM and Nott, agreement among the remaining methods was poor such that their interchangeable use in clinical practice is not recommended.

  4. RNA FISH for detecting expanded repeats in human diseases.

    Science.gov (United States)

    Urbanek, Martyna O; Krzyzosiak, Wlodzimierz J

    2016-04-01

    RNA fluorescence in situ hybridization (FISH) is a widely used technique for detecting transcripts in fixed cells and tissues. Many variants of RNA FISH have been proposed to increase signal strength, resolution and target specificity. The current variants of this technique facilitate the detection of the subcellular localization of transcripts at a single molecule level. Among the applications of RNA FISH are studies on nuclear RNA foci in diseases resulting from the expansion of tri-, tetra-, penta- and hexanucleotide repeats present in different single genes. The partial or complete retention of mutant transcripts forming RNA aggregates within the nucleoplasm has been shown in multiple cellular disease models and in the tissues of patients affected with these atypical mutations. Relevant diseases include, among others, myotonic dystrophy type 1 (DM1) with CUG repeats, Huntington's disease (HD) and spinocerebellar ataxia type 3 (SCA3) with CAG repeats, fragile X-associated tremor/ataxia syndrome (FXTAS) with CGG repeats, myotonic dystrophy type 2 (DM2) with CCUG repeats, amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) with GGGGCC repeats and spinocerebellar ataxia type 32 (SCA32) with GGCCUG. In this article, we summarize the results obtained with FISH to examine RNA nuclear inclusions. We provide a detailed protocol for detecting RNAs containing expanded CAG and CUG repeats in different cellular models, including fibroblasts, lymphoblasts, induced pluripotent stem cells and murine and human neuronal progenitors. We also present the results of the first single-molecule FISH application in a cellular model of polyglutamine disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. REPEATABILITY OF FRUIT QUALITY TRAITS OF CACTUS PEAR

    Directory of Open Access Journals (Sweden)

    VALTÂNIA XAVIER NUNES

    2017-12-01

    Full Text Available ABSTRACT Repeatability analysis has been used to study traits in several crops, assisting in the definition of the minimum number needed to evaluate genotypes more efficiently and with less time and resource consumption. So far, however, no repeatability studies on cactus pear have been found in the literature. The objective of this study was to determine the coefficient of repeatability for cactus pear fruits traits and the minimum number of evaluations (fruit that can provide acceptable accuracy for the prediction of the true value. The experiment was conducted at the Federal Institute of Bahia/Campus Guanambi, with 150 fruits collected from three municipalities in the state of Bahia. The coefficients of repeatability were estimated by the methods of analysis of variance, principal components based on the covariance (PCCV and correlation (PCC matrices, and structural analysis based on the correlation matrix (SA. The analysis of variance showed that, except for fruit diameter, the effect of the production site (municipality was significant for all traits evaluated. The PCCV method was proven the most suitable for studying the repeatability of quality traits of cactus pear fruits. Seven fruits were required to determine, with 90% confidence, the traits length, diameter, fruit firmness, skin thickness, number of seeds, fruit mass, bark mass, pulp mass, pH, titratable acidity, soluble solids, SS/AT ratio, and pulp yield.

  6. Incremental Dynamic Analysis of Koyna Dam under Repeated Ground Motions

    Science.gov (United States)

    Zainab Nik Azizan, Nik; Majid, Taksiah A.; Nazri, Fadzli Mohamed; Maity, Damodar; Abdullah, Junaidah

    2018-03-01

    This paper discovers the incremental dynamic analysis (IDA) of concrete gravity dam under single and repeated earthquake loadings to identify the limit state of the dam. Seven ground motions with horizontal and vertical direction as seismic input considered in the nonlinear dynamic analysis based on the real repeated earthquake in the worldwide. All the ground motions convert to respond spectrum and scaled according to the developed elastic respond spectrum in order to match the characteristic of the ground motion to the soil type. The scaled was depends on the fundamental period, T1 of the dam. The Koyna dam has been selected as a case study for the purpose of the analysis by assuming that no sliding and rigid foundation, has been estimated. IDA curves for Koyna dam developed for single and repeated ground motions and the performance level of the dam identifies. The IDA curve of repeated ground motion shown stiffer rather than single ground motion. The ultimate state displacement for a single event is 45.59mm and decreased to 39.33mm under repeated events which are decreased about 14%. This showed that the performance level of the dam based on seismic loadings depend on ground motion pattern.

  7. Flanking Variation Influences Rates of Stutter in Simple Repeats

    Directory of Open Access Journals (Sweden)

    August E. Woerner

    2017-11-01

    Full Text Available It has been posited that the longest uninterrupted stretch (LUS of tandem repeats, as defined by the number of exactly matching repeating motif units, is a better predictor of rates of stutter than the parental allele length (PAL. While there are cases where this hypothesis is likely correct, such as the 9.3 allele in the TH01 locus, there can be situations where it may not apply as well. For example, the PAL may capture flanking indel variations while remaining insensitive to polymorphisms in the repeat, and these haplotypic changes may impact the stutter rate. To address this, rates of stutter were contrasted against the LUS as well as the PAL on different flanking haplotypic backgrounds. This study shows that rates of stutter can vary substantially depending on the flanking haplotype, and while there are cases where the LUS is a better predictor of stutter than the PAL, examples to the contrary are apparent in commonly assayed forensic markers. Further, flanking variation that is 7 bp from the repeat region can impact rates of stutter. These findings suggest that non-proximal effects, such as DNA secondary structure, may be impacting the rates of stutter in common forensic short tandem repeat markers.

  8. A COMPARISON OF PAIRS FIGURE SKATERS IN REPEATED JUMPS

    Directory of Open Access Journals (Sweden)

    William A. Sands

    2012-03-01

    Full Text Available Trends in pairs figure skating have shown that increasingly difficult jumps have become an essential aspect of high-level performance, especially in the latter part of a competitive program. We compared a repeated jump power index in a 60 s repeated jump test to determine the relationship of repeated jump test to competitive rank and to measure 2D hip, knee, and ankle angles and angular velocities at 0, 20, 40, and 60 s. Eighteen National Team Pairs Figure Skaters performed a 60 s repeated jump test on a large switch-mat with timing of flight and ground durations and digital video recording. Each 60-s period was divided into 6, 10-s intervals, with power indexes (W/kg calculated for each 10-s interval. Power index by 10-s interval repeated measures ANOVAs (RMANOVA showed that males exceeded females at all intervals, and the highest power index interval was during 10 to 20 s for both sexes. RMANOVAs of angles and angular velocities showed main effects for time only. Power index and jumping techniques among figure skaters showed rapid and steady declines over the test duration. Power index can predict approximately 50% of competitive rank variance, and sex differences in jumping technique were rare

  9. Alanine repeats influence protein localization in splicing speckles and paraspeckles.

    Science.gov (United States)

    Chang, Shuo-Hsiu; Chang, Wei-Lun; Lu, Chia-Chen; Tarn, Woan-Yuh

    2014-12-16

    Mammalian splicing regulatory protein RNA-binding motif protein 4 (RBM4) has an alanine repeat-containing C-terminal domain (CAD) that confers both nuclear- and splicing speckle-targeting activities. Alanine-repeat expansion has pathological potential. Here we show that the alanine-repeat tracts influence the subnuclear targeting properties of the RBM4 CAD in cultured human cells. Notably, truncation of the alanine tracts redistributed a portion of RBM4 to paraspeckles. The alanine-deficient CAD was sufficient for paraspeckle targeting. On the other hand, alanine-repeat expansion reduced the mobility of RBM4 and impaired its splicing activity. We further took advantage of the putative coactivator activator (CoAA)-RBM4 conjoined splicing factor, CoAZ, to investigate the function of the CAD in subnuclear targeting. Transiently expressed CoAZ formed discrete nuclear foci that emerged and subsequently separated-fully or partially-from paraspeckles. Alanine-repeat expansion appeared to prevent CoAZ separation from paraspeckles, resulting in their complete colocalization. CoAZ foci were dynamic but, unlike paraspeckles, were resistant to RNase treatment. Our results indicate that the alanine-rich CAD, in conjunction with its conjoined RNA-binding domain(s), differentially influences the subnuclear localization and biogenesis of RBM4 and CoAZ. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  10. Design and analysis of communication protocols for quantum repeater networks

    International Nuclear Information System (INIS)

    Jones, Cody; Kim, Danny; Rakher, Matthew T; Ladd, Thaddeus D; Kwiat, Paul G

    2016-01-01

    We analyze how the performance of a quantum-repeater network depends on the protocol employed to distribute entanglement, and we find that the choice of repeater-to-repeater link protocol has a profound impact on entanglement-distribution rate as a function of hardware parameters. We develop numerical simulations of quantum networks using different protocols, where the repeater hardware is modeled in terms of key performance parameters, such as photon generation rate and collection efficiency. These parameters are motivated by recent experimental demonstrations in quantum dots, trapped ions, and nitrogen-vacancy centers in diamond. We find that a quantum-dot repeater with the newest protocol (‘MidpointSource’) delivers the highest entanglement-distribution rate for typical cases where there is low probability of establishing entanglement per transmission, and in some cases the rate is orders of magnitude higher than other schemes. Our simulation tools can be used to evaluate communication protocols as part of designing a large-scale quantum network. (paper)

  11. Electromyographic analysis of repeated bouts of eccentric exercise.

    Science.gov (United States)

    McHugh, M P; Connolly, D A; Eston, R G; Gartman, E J; Gleim, G W

    2001-03-01

    The repeated bout effect refers to the protective effect provided by a single bout of eccentric exercise against muscle damage from a similar subsequent bout. The aim of this study was to determine if the repeated bout was associated with an increase in motor unit activation relative to force production, an increased recruitment of slow-twitch motor units or increased motor unit synchronization. Surface electromyographic (EMG) signals were recorded from the hamstring muscles during two bouts of submaximal isokinetic (2.6 rad x s(-1)) eccentric (11 men, 9 women) or concentric (6 men, 4 women) contractions separated by 2 weeks. The EMG per unit torque and median frequency were analysed. The initial bout of eccentric exercise resulted in strength loss, pain and muscle tenderness, while the repeated eccentric bout resulted in a slight increase in strength, no pain and no muscle tenderness (bout x time effects, P exercise. The EMG per unit torque and median frequency were not different between the initial and repeated bouts of eccentric exercise. The EMG per unit torque and median frequency increased during both bouts of eccentric exercise (P < 0.01) but did not change during either concentric bout. In conclusion, there was no evidence that the repeated bout effect was due to a neural adaptation.

  12. RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

    Directory of Open Access Journals (Sweden)

    Aisling Frizzell

    2014-03-01

    Full Text Available Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG repeat expansions and fragility, likely by unwinding problematic hairpins.

  13. RTEL1 inhibits trinucleotide repeat expansions and fragility.

    Science.gov (United States)

    Frizzell, Aisling; Nguyen, Jennifer H G; Petalcorin, Mark I R; Turner, Katherine D; Boulton, Simon J; Freudenreich, Catherine H; Lahue, Robert S

    2014-03-13

    Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG) repeat expansions and fragility, likely by unwinding problematic hairpins. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  14. The diversity and evolution of Wolbachia ankyrin repeat domain genes.

    Directory of Open Access Journals (Sweden)

    Stefanos Siozios

    Full Text Available Ankyrin repeat domain-encoding genes are common in the eukaryotic and viral domains of life, but they are rare in bacteria, the exception being a few obligate or facultative intracellular Proteobacteria species. Despite having a reduced genome, the arthropod strains of the alphaproteobacterium Wolbachia contain an unusually high number of ankyrin repeat domain-encoding genes ranging from 23 in wMel to 60 in wPip strain. This group of genes has attracted considerable attention for their astonishing large number as well as for the fact that ankyrin proteins are known to participate in protein-protein interactions, suggesting that they play a critical role in the molecular mechanism that determines host-Wolbachia symbiotic interactions. We present a comparative evolutionary analysis of the wMel-related ankyrin repeat domain-encoding genes present in different Drosophila-Wolbachia associations. Our results show that the ankyrin repeat domain-encoding genes change in size by expansion and contraction mediated by short directly repeated sequences. We provide examples of intra-genic recombination events and show that these genes are likely to be horizontally transferred between strains with the aid of bacteriophages. These results confirm previous findings that the Wolbachia genomes are evolutionary mosaics and illustrate the potential that these bacteria have to generate diversity in proteins potentially involved in the symbiotic interactions.

  15. Discrepancy variation of dinucleotide microsatellite repeats in eukaryotic genomes

    Directory of Open Access Journals (Sweden)

    HUAN GAO

    2009-01-01

    Full Text Available To address whether there are differences of variation among repeat motif types and among taxonomic groups, we present here an analysis of variation and correlation of dinucleotide microsatellite repeats in eukaryotic genomes. Ten taxonomic groups were compared, those being primates, mammalia (excluding primates and rodentia, rodentia, birds, fish, amphibians and reptiles, insects, molluscs, plants and fungi, respectively. The data used in the analysis is from the literature published in the Journal of Molecular Ecology Notes. Analysis of variation reveals that there are no significant differences between AC and AG repeat motif types. Moreover, the number of alleles correlates positively with the copy number in both AG and AC repeats. Similar conclusions can be obtained from each taxonomic group. These results strongly suggest that the increase of SSR variation is almost linear with the increase of the copy number of each repeat motif. As well, the results suggest that the variability of SSR in the genomes of low-ranking species seem to be more than that of high-ranking species, excluding primates and fungi.

  16. Instability of (CTGn•(CAGn trinucleotide repeats and DNA synthesis

    Directory of Open Access Journals (Sweden)

    Liu Guoqi

    2012-02-01

    Full Text Available Abstract Expansion of (CTGn•(CAGn trinucleotide repeat (TNR microsatellite sequences is the cause of more than a dozen human neurodegenerative diseases. (CTGn and (CAGn repeats form imperfectly base paired hairpins that tend to expand in vivo in a length-dependent manner. Yeast, mouse and human models confirm that (CTGn•(CAGn instability increases with repeat number, and implicate both DNA replication and DNA damage response mechanisms in (CTGn•(CAGn TNR expansion and contraction. Mutation and knockdown models that abrogate the expression of individual genes might also mask more subtle, cumulative effects of multiple additional pathways on (CTGn•(CAGn instability in whole animals. The identification of second site genetic modifiers may help to explain the variability of (CTGn•(CAGn TNR instability patterns between tissues and individuals, and offer opportunities for prognosis and treatment.

  17. Absence of bacterial resistance following repeat exposure to photodynamic therapy

    Science.gov (United States)

    Pedigo, Lisa A.; Gibbs, Aaron J.; Scott, Robert J.; Street, Cale N.

    2009-06-01

    The prevalence of antibiotic resistant bacteria necessitates exploration of alternative approaches to treat hospital and community acquired infections. The aim of this study was to determine whether bacterial pathogens develop resistance to antimicrobial photodynamic therapy (aPDT) during repeated sub-lethal challenge. Antibiotic sensitive and resistant strains of S. aureus and antibiotic sensitive E. coli were subjected to repeat PDT treatments using a methylene blue photosensitizer formulation and 670 nm illumination from a non-thermal diode laser. Parameters were adjusted such that kills were antibiotic resistance strains. Furthermore, repeated sub-lethal exposure does not induce resistance to subsequent PDT treatments. The absence of resistance formation represents a significant advantage of PDT over traditional antibiotics.

  18. Secondary immune response of rainbow trout following repeated immersion vaccination

    DEFF Research Database (Denmark)

    Jaafar, R. M.; Al-Jubury, A.; Chettri, J. K.

    2017-01-01

    Teleosts are able to raise a protective immune response, comprising both innate and adaptive elements, against various pathogens. This is the basis for a widespread use of vaccines, administered as injection or immersion, in the aquaculture industry. It has been described that repeated injection...... vaccination of fish raises a secondary immune response, consisting of rapid, accelerated and increased antibody reaction. This study reports how rainbow trout responds to repeated immersion vaccination against yersiniosis (ERM) caused by the bacterial pathogen Yersinia ruckeri. It was found that rainbow trout...... does not raise a classical secondary response following repeated immersion vaccination. Serum antibody titres were merely slightly increased even after three immunizations, using 30-s immersion into a bacterin consisting of formalin-inactivated Y. ruckeri (serotype O1, biotypes 1 and 2), performed over...

  19. Secondary immune response of rainbow trout following repeated immersion vaccination

    DEFF Research Database (Denmark)

    Jaafar, R. M.; Al-Jubury, Azmi; Chettri, Jiwan Kumar

    2018-01-01

    Teleosts are able to raise a protective immune response, comprising both innate and adaptive elements, against various pathogens. This is the basis for a widespread use of vaccines, administered as injection or immersion, in the aquaculture industry. It has been described that repeated injection...... vaccination of fish raises a secondary immune response, consisting of rapid, accelerated and increased antibody reaction. This study reports how rainbow trout responds to repeated immersion vaccination against yersiniosis (ERM) caused by the bacterial pathogen Yersinia ruckeri. It was found that rainbow trout...... does not raise a classical secondary response following repeated immersion vaccination. Serum antibody titres were merely slightly increased even after three immunizations, using 30-s immersion into a bacterin consisting of formalin-inactivated Y. ruckeri (serotype O1, biotypes 1 and 2), performed over...

  20. Gene conversion homogenizes the CMT1A paralogous repeats

    Directory of Open Access Journals (Sweden)

    Hurles Matthew E

    2001-12-01

    Full Text Available Abstract Background Non-allelic homologous recombination between paralogous repeats is increasingly being recognized as a major mechanism causing both pathogenic microdeletions and duplications, and structural polymorphism in the human genome. It has recently been shown empirically that gene conversion can homogenize such repeats, resulting in longer stretches of absolute identity that may increase the rate of non-allelic homologous recombination. Results Here, a statistical test to detect gene conversion between pairs of non-coding sequences is presented. It is shown that the 24 kb Charcot-Marie-Tooth type 1A paralogous repeats (CMT1A-REPs exhibit the imprint of gene conversion processes whilst control orthologous sequences do not. In addition, Monte Carlo simulations of the evolutionary divergence of the CMT1A-REPs, incorporating two alternative models for gene conversion, generate repeats that are statistically indistinguishable from the observed repeats. Bounds are placed on the rate of these conversion processes, with central values of 1.3 × 10-4 and 5.1 × 10-5 per generation for the alternative models. Conclusions This evidence presented here suggests that gene conversion may have played an important role in the evolution of the CMT1A-REP paralogous repeats. The rates of these processes are such that it is probable that homogenized CMT1A-REPs are polymorphic within modern populations. Gene conversion processes are similarly likely to play an important role in the evolution of other segmental duplications and may influence the rate of non-allelic homologous recombination between them.

  1. Low-Normal FMR1 CGG Repeat Length: Phenotypic Associations

    Directory of Open Access Journals (Sweden)

    Marsha eMailick

    2014-09-01

    Full Text Available This population-based study investigates genotype-phenotype correlations of low-normal CGG repeats in the fragile X mental retardation 1 (FMR1 gene. FMR1 plays an important role in brain development and function, and encodes FMRP (fragile X mental retardation protein, an RNA-binding protein that regulates protein synthesis impacting activity-dependent synaptic development and plasticity. Most past research has focused on CGG premutation expansions (41 to 200 CGG repeats and on fragile X syndrome (200+ CGG repeats, with considerably less attention on the other end of the spectrum of CGG repeats. Using existing data, older adults with 23 or fewer CGG repeats (2 SDs below the mean were compared with age-peers who have normal numbers of CGGs (24-40 with respect to cognition, mental health, cancer, and having children with disabilities. Men (n = 341 with an allele in the low-normal range and women (n = 46 with two low-normal alleles had significantly more difficulty with their memory and ability to solve day to day problems. Women with both FMR1 alleles in the low-normal category had significantly elevated odds of feeling that they need to drink more to get the same effect as in the past. These women also had two and one-half times the odds of having had breast cancer and four times the odds of uterine cancer. Men and women with low-normal CGGs had higher odds of having a child with a disability, either a developmental disability or a mental health condition. These findings are in line with the hypothesis that there is a need for tight neuronal homeostatic control mechanisms for optimal cognitive and behavioral functioning, and more generally that low numbers as well as high numbers of CGG repeats may be problematic for health.

  2. Repeat-aware modeling and correction of short read errors.

    Science.gov (United States)

    Yang, Xiao; Aluru, Srinivas; Dorman, Karin S

    2011-02-15

    High-throughput short read sequencing is revolutionizing genomics and systems biology research by enabling cost-effective deep coverage sequencing of genomes and transcriptomes. Error detection and correction are crucial to many short read sequencing applications including de novo genome sequencing, genome resequencing, and digital gene expression analysis. Short read error detection is typically carried out by counting the observed frequencies of kmers in reads and validating those with frequencies exceeding a threshold. In case of genomes with high repeat content, an erroneous kmer may be frequently observed if it has few nucleotide differences with valid kmers with multiple occurrences in the genome. Error detection and correction were mostly applied to genomes with low repeat content and this remains a challenging problem for genomes with high repeat content. We develop a statistical model and a computational method for error detection and correction in the presence of genomic repeats. We propose a method to infer genomic frequencies of kmers from their observed frequencies by analyzing the misread relationships among observed kmers. We also propose a method to estimate the threshold useful for validating kmers whose estimated genomic frequency exceeds the threshold. We demonstrate that superior error detection is achieved using these methods. Furthermore, we break away from the common assumption of uniformly distributed errors within a read, and provide a framework to model position-dependent error occurrence frequencies common to many short read platforms. Lastly, we achieve better error correction in genomes with high repeat content. The software is implemented in C++ and is freely available under GNU GPL3 license and Boost Software V1.0 license at "http://aluru-sun.ece.iastate.edu/doku.php?id = redeem". We introduce a statistical framework to model sequencing errors in next-generation reads, which led to promising results in detecting and correcting errors

  3. Repeat: a framework to assess empirical reproducibility in biomedical research

    Directory of Open Access Journals (Sweden)

    Leslie D. McIntosh

    2017-09-01

    Full Text Available Abstract Background The reproducibility of research is essential to rigorous science, yet significant concerns of the reliability and verifiability of biomedical research have been recently highlighted. Ongoing efforts across several domains of science and policy are working to clarify the fundamental characteristics of reproducibility and to enhance the transparency and accessibility of research. Methods The aim of the proceeding work is to develop an assessment tool operationalizing key concepts of research transparency in the biomedical domain, specifically for secondary biomedical data research using electronic health record data. The tool (RepeAT was developed through a multi-phase process that involved coding and extracting recommendations and practices for improving reproducibility from publications and reports across the biomedical and statistical sciences, field testing the instrument, and refining variables. Results RepeAT includes 119 unique variables grouped into five categories (research design and aim, database and data collection methods, data mining and data cleaning, data analysis, data sharing and documentation. Preliminary results in manually processing 40 scientific manuscripts indicate components of the proposed framework with strong inter-rater reliability, as well as directions for further research and refinement of RepeAT. Conclusions The use of RepeAT may allow the biomedical community to have a better understanding of the current practices of research transparency and accessibility among principal investigators. Common adoption of RepeAT may improve reporting of research practices and the availability of research outputs. Additionally, use of RepeAT will facilitate comparisons of research transparency and accessibility across domains and institutions.

  4. Layered Architectures for Quantum Computers and Quantum Repeaters

    Science.gov (United States)

    Jones, Nathan C.

    This chapter examines how to organize quantum computers and repeaters using a systematic framework known as layered architecture, where machine control is organized in layers associated with specialized tasks. The framework is flexible and could be used for analysis and comparison of quantum information systems. To demonstrate the design principles in practice, we develop architectures for quantum computers and quantum repeaters based on optically controlled quantum dots, showing how a myriad of technologies must operate synchronously to achieve fault-tolerance. Optical control makes information processing in this system very fast, scalable to large problem sizes, and extendable to quantum communication.

  5. Construction of a quantum repeater with linear optics

    International Nuclear Information System (INIS)

    Kok, Pieter; Williams, Colin P.; Dowling, Jonathan P.

    2003-01-01

    We study the mechanism and complexity of an efficient quantum repeater, employing double-photon guns, for long-distance optical quantum communication. The guns create polarization-entangled photon pairs on demand. One such source might be a semiconducter quantum dot, which has the distinct advantage over parametric down-conversion that the probability of creating a photon pair is close to 1, while the probability of creating multiple pairs vanishes. The swapping and purifying components are implemented by polarizing beam splitters and probabilistic optical controlled-NOT gates. We also show that the bottleneck in the efficiency of this repeater is due to detector losses

  6. Relationship between income and repeat criminal victimization in Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo Justus

    2015-09-01

    Full Text Available This study analyzes the effect of income on repeat criminal victimization in Brazil using data from the 2009 National Household Sample Survey and its special supplement on victimization and access to justice. Two count-data models were estimated for four types of crime: theft, robbery, attempted theft/robbery, and physical assault. A positive nonlinear effect of income on repeat victimization for the three types of property crimes and a negative nonlinear effect of income on physical assault were observed.

  7. USGS Southwest Repeat Photography Collection: Kanab Creek, southern Utah and northern Arizona, 1872-2010

    Data.gov (United States)

    Department of the Interior — The USGS Southwest Repeat Photography Collection (‘Collection’), formerly named the Desert Laboratory Repeat Photography Collection, is now housed by the Southwest...

  8. Do repeated rumble strip hits improve driver alertness?

    NARCIS (Netherlands)

    Watling, C.N.; Akerstedt, T.; Kecklund, L.G.; Anund, A.

    2016-01-01

    Driving while sleepy is associated with increased crash risk. Rumble strips are designed to alert a sleepy or inattentive driver when they deviate outside their driving lane. The current study sought to examine the effects of repeated rumble strip hits on levels of physiological and subjective

  9. The repeatability of reproduction rate in the Tygerboek Merino Dock ...

    African Journals Online (AJOL)

    The repeatability of reproduction rate at 2 years or up to 3 years of age was investigated by regression methods considering subsequent reproduction ... would not improve Lb/Em in the current flock sUbstantially, whereas the proportion of ewes bearing multiples at 2 years was too low to supply replacement requirements.

  10. ATXN2 trinucleotide repeat length correlates with risk of ALS

    NARCIS (Netherlands)

    Sproviero, William; Shatunov, Aleksey; Stahl, Daniel; Shoai, Maryam; van Rheenen, Wouter; Jones, Ashley R; Al-Sarraj, Safa; Andersen, Peter M.; Bonini, Nancy M; Conforti, Francesca L; Van Damme, Philip; Daoud, Hussein; Del Mar Amador, Maria; Fogh, Isabella; Forzan, Monica; Gaastra, Ben; Gellera, Cinzia; Gitler, Aaron D; Hardy, John; Fratta, Pietro; La Bella, Vincenzo; Le Ber, Isabelle; Van Langenhove, Tim; Lattante, Serena; Lee, Yi-Chung; Malaspina, Andrea; Meininger, Vincent; Millecamps, Stéphanie; Orrell, Richard W; Rademakers, Rosa; Robberecht, Wim; Rouleau, Guy A.; Ross, Owen A; Salachas, Francois; Sidle, Katie; Smith, Bradley N; Soong, Bing-Wen; Sorarù, Gianni; Stevanin, Giovanni; Kabashi, Edor; Troakes, Claire; van Broeckhoven, Christine; Veldink, Jan H.; van den Berg, Leonard H.; Shaw, Christopher E; Powell, John F.; Al-Chalabi, Ammar

    2017-01-01

    We investigated a CAG trinucleotide repeat expansion in the ATXN2 gene in amyotrophic lateral sclerosis (ALS). Two new case-control studies, a British dataset of 1474 ALS cases and 567 controls, and a Dutch dataset of 1328 ALS cases and 691 controls were analyzed. In addition, to increase power, we

  11. Antithrombotic effect of repeated doses of the ethanolic extract of ...

    African Journals Online (AJOL)

    Antithrombotic effect of repeated doses of the ethanolic extract of local olive ( Olea europaea L.) leaves in rabbits. ... The incidence of thromboembolic diseases is increasing, and they are a major cause of mortality and morbidity worldwide. Mediterranean diet is known for its high content of olive products, especially olive oil, ...

  12. Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

    Science.gov (United States)

    Doğan, Aysun Şanal; Gürdal, Canan; Köylü, Mehmet Talay

    2018-04-01

    The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy). Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198) and gender (M/F: 4/29 vs. 8/32, p=0.366). Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90). The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

  13. Development of repeated sprint ability in talented youth basketball players

    NARCIS (Netherlands)

    te Wierike, Simon; Lemmink, Koen; de Jong, M.C.; Tromp, E.J.; Vuijk, P.J.; Malina, R.M.; Elferink-Gemser, Marije; Visscher, Chris

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  14. Repeated Recall and PKM? Maintain Fear Memories in Juvenile Rats

    Science.gov (United States)

    Oliver, Chicora F.; Kabitzke, Patricia; Serrano, Peter; Egan, Laura J.; Barr, Gordon A.; Shair, Harry N.; Wiedenmayer, Christoph

    2016-01-01

    We examined the neural substrates of fear memory formation and maintenance when repeated recall was used to prevent forgetting in young animals. In contrast to adult rats, juveniles failed to show contextual fear responses at 4 d post-fear conditioning. Reconsolidation sessions 3 and 6 d after conditioning restored contextual fear responses in…

  15. Complexity of repeated game model in electric power triopoly

    International Nuclear Information System (INIS)

    Ma Junhai; Ji Weizhuo

    2009-01-01

    According to the repeated game model in electric power duopoly, a triopoly outputs game model is presented. On the basis of some hypotheses, the dynamic characters are demonstrated with theoretical analysis and numerical simulations. The results show that the triopoly model is a chaotic system and it is better than the duopoly model in applications.

  16. Repeated oral administration of capsaicin increases anxiety-like ...

    Indian Academy of Sciences (India)

    This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy ...

  17. Vital Signs – Preventing Repeat Teen Births

    Centers for Disease Control (CDC) Podcasts

    2013-04-02

    This podcast is based on the April 2013 CDC Vital Signs report, which discusses repeat teen births and ways teens, parents and guardians, health care providers, and communities can help prevent them.  Created: 4/2/2013 by Centers for Disease Control and Prevention (CDC).   Date Released: 4/2/2013.

  18. Y-Chromosome short tandem repeat, typing technology, locus ...

    African Journals Online (AJOL)

    Aghomotsegin

    2015-07-08

    Jul 8, 2015 ... Y-Chromosome short tandem repeat, typing technology, locus information and allele frequency in different population: A review. Muhanned Abdulhasan Kareem1, Ameera Omran Hussein2 and Imad Hadi Hameed2*. 1Babylon University, Centre of Environmental Research, Hilla City, Iraq. 2Department of ...

  19. Genetic Analysis of Eight X-Chromosomal Short Tandem Repeat ...

    African Journals Online (AJOL)

    X-Chromosome short tandem repeat (STR) typing can complement existing DNA profiling protocols and can also offer useful information in cases of complex kinship analysis. This is the first population study of 8 X-linked STRs in Iraq. The purpose of this work was to provide a basic data of allele and haplotype frequency for ...

  20. X-Chromosome short tandem repeat, advantages and typing ...

    African Journals Online (AJOL)

    Microsatellites of the X-chromosome have been increasingly studied in recent years as a useful tool in forensic analysis. This review describes some details of X-chromosomal short tandem repeat (STR) analysis. Among them are: microsatellites, amplification using polymerase chain reaction (PCR) of STRs, PCR product ...

  1. Does Dry Eye Affect Repeatability of Corneal Topography Measurements?

    Directory of Open Access Journals (Sweden)

    Aysun Şanal Doğan

    2018-04-01

    Full Text Available Objectives: The purpose of this study was to assess the repeatability of corneal topography measurements in dry eye patients and healthy controls. Materials and Methods: Participants underwent consecutive corneal topography measurements (Sirius; Costruzione Strumenti Oftalmici, Florence, Italy. Two images with acquisition quality higher than 90% were accepted. The following parameters were evaluated: minimum and central corneal thickness, aqueous depth, apex curvature, anterior chamber volume, horizontal anterior chamber diameter, iridocorneal angle, cornea volume, and average simulated keratometry. Repeatability was assessed by calculating intra-class correlation coefficient. Results: Thirty-three patients with dry eye syndrome and 40 healthy controls were enrolled to the study. The groups were similar in terms of age (39 [18-65] vs. 30.5 [18-65] years, p=0.198 and gender (M/F: 4/29 vs. 8/32, p=0.366. Intra-class correlation coefficients among all topography parameters within both groups showed excellent repeatability (>0.90. Conclusion: The anterior segment measurements provided by the Sirius corneal topography system were highly repeatable for dry eye patients and are sufficiently reliable for clinical practice and research.

  2. Repeated treatments of drooling with botulinum toxin B in neurology

    DEFF Research Database (Denmark)

    Møller, Eigild; Daugaard, Dorthe; Holm, Ole

    2015-01-01

    OBJECTIVES: To investigate efficacy, saliva flow, and composition in repeated BoNT-B treatments of drooling. MATERIALS AND METHODS: Seventeen neurological patients (median 66 years), referred for treatment of drooling participated in this observational study. Median total doses of 4000 units...

  3. Modeling and evaluating repeatability and reproducibility of ordinal classifications

    NARCIS (Netherlands)

    de Mast, J.; van Wieringen, W.N.

    2010-01-01

    This paper argues that currently available methods for the assessment of the repeatability and reproducibility of ordinal classifications are not satisfactory. The paper aims to study whether we can modify a class of models from Item Response Theory, well established for the study of the reliability

  4. The effectiveness of eye-closure in repeated interviews

    NARCIS (Netherlands)

    Vredeveldt, A.; Baddeley, A.D.; Hitch, G.J.

    2014-01-01

    Purpose Closing the eyes during recall can help witnesses remember more about a witnessed event. This study examined the effectiveness of eye-closure in a repeated recall paradigm with immediate free recall followed 1 week later by both free and cued recall. We examined whether eye-closure was more

  5. Analysis of unknown cause subarachnoid hemorrhage with repeated negative angiogram

    International Nuclear Information System (INIS)

    Fujii, Mutsumi; Takasato, Yoshio; Masaoka, Hiroyuki; Ohta, Yoshihisa; Hayakawa, Takanori; Honma, Masato

    2006-01-01

    Seven hundred and fifty five cases of acute non-traumatic subarachnoid hemorrhage (SAH) were admitted to the department of neurosurgery of our hospital from July, 1995 to March, 2004. In 555 patients cerebral angiography was conducted but initial angiography was negative in 30 patients. Except 10 general condition poor patients, in 20 initial angiogram-negative patients were undergone repeated angiography. The cause of SAH could not be demonstrated in 13 cases. The SAH in perimesencephalic and non-perimesencephalic cisturns was seen in 7 and 6 cases, respectively. Occipital and/or neck pain on admission was statistically more common among patients with perimesencephalic SAH than those with non-perimesencephalic SAH (p=0.029), and the prognosis of perimesencephalic SAH was good. We conclude that repeat angiography should not be recommended in patients with perimesencephalic SAH. Patients with non-perimesencephalic SAH had a higher rate of complication. In the non-perimesencephalic group, 3 patients developed hydrocephalus and 3 patients had vasospasm, which were found by repeated angiography. Therefore, repeated angiography is recommended for better clinical outcome by early detection and management of serious complications in this group of patients. (author)

  6. Large Torque Variations in Two Soft Gamma Repeaters

    NARCIS (Netherlands)

    Woods, P.M.; Kouveliotou, C.; Göğüş, E.; Finger, M.H.; Swank, J.; Markwardt, C.B.; Hurley, K.; van der Klis, M.

    2002-01-01

    We have monitored the pulse frequencies of the two soft gamma repeaters SGR 1806-20 and SGR 1900+14 through the beginning of year 2001 using primarily Rossi X-Ray Timing Explorer Proportional Counter Array observations. In both sources, we observe large changes in the spin-down torque up to a factor

  7. Insertion device and method for accurate and repeatable target insertion

    Science.gov (United States)

    Gubeli, III, Joseph F.; Shinn, Michelle D.; Bevins, Michael E.; Dillon-Townes, Lawrence; Neil, George R.

    2017-07-04

    The present invention discloses a device and a method for inserting and positioning a target within a free electron laser, particle accelerator, or other such device that generates or utilizes a beam of energy or particles. The system includes a three-point registration mechanism that insures angular and translational accuracy and repeatability of positioning upon multiple insertions within the same structure.

  8. Development of simple sequence repeat (SSR) markers that are ...

    African Journals Online (AJOL)

    Simple sequence repeats (SSRs) markers were developed through data mining of 3,803 expressed sequence tags (ESTs) previously published. A total of 144 di- to penta-type SSRs were identified and they were screened for polymorphism between two turnip cultivars, 'Tsuda' and 'Yurugi Akamaru'. Out of 90 EST-SSRs for ...

  9. Comparative effectiveness of inter-simple sequence repeat and ...

    African Journals Online (AJOL)

    A study to compare the effectiveness of inter-simple sequence repeats (ISSR) and randomly amplified polymorphic DNA (RAPD) profiling was carried out with a total of 65 DNA samples using 12 species of Indian Garcinia. ISSR and RAPD profiling were performed with 19 and 12 primers, respectively. ISSR markers ...

  10. Repfinder: Finding approximately repeated scene elements for image editing

    KAUST Repository

    Cheng, Ming-Ming

    2010-07-26

    Repeated elements are ubiquitous and abundant in both manmade and natural scenes. Editing such images while preserving the repetitions and their relations is nontrivial due to overlap, missing parts, deformation across instances, illumination variation, etc. Manually enforcing such relations is laborious and error-prone. We propose a novel framework where user scribbles are used to guide detection and extraction of such repeated elements. Our detection process, which is based on a novel boundary band method, robustly extracts the repetitions along with their deformations. The algorithm only considers the shape of the elements, and ignores similarity based on color, texture, etc. We then use topological sorting to establish a partial depth ordering of overlapping repeated instances. Missing parts on occluded instances are completed using information from other instances. The extracted repeated instances can then be seamlessly edited and manipulated for a variety of high level tasks that are otherwise difficult to perform. We demonstrate the versatility of our framework on a large set of inputs of varying complexity, showing applications to image rearrangement, edit transfer, deformation propagation, and instance replacement. © 2010 ACM.

  11. Non-radioactive detection of trinucleotide repeat size variability.

    Science.gov (United States)

    Tomé, Stéphanie; Nicole, Annie; Gomes-Pereira, Mario; Gourdon, Genevieve

    2014-03-06

    Many human diseases are associated with the abnormal expansion of unstable trinucleotide repeat sequences. The mechanisms of trinucleotide repeat size mutation have not been fully dissected, and their understanding must be grounded on the detailed analysis of repeat size distributions in human tissues and animal models. Small-pool PCR (SP-PCR) is a robust, highly sensitive and efficient PCR-based approach to assess the levels of repeat size variation, providing both quantitative and qualitative data. The method relies on the amplification of a very low number of DNA molecules, through sucessive dilution of a stock genomic DNA solution. Radioactive Southern blot hybridization is sensitive enough to detect SP-PCR products derived from single template molecules, separated by agarose gel electrophoresis and transferred onto DNA membranes. We describe a variation of the detection method that uses digoxigenin-labelled locked nucleic acid probes. This protocol keeps the sensitivity of the original method, while eliminating the health risks associated with the manipulation of radiolabelled probes, and the burden associated with their regulation, manipulation and waste disposal.

  12. Benefits of Repeated Book Readings in Children with SLI

    Science.gov (United States)

    Rohlfing, Katharina J.; Ceurremans, Josefa; Horst, Jessica S.

    2018-01-01

    In this pilot study, we ask whether repeated storybook reading is also beneficial for word learning in children diagnosed with specific language impairment (SLI). We compared 3-year-old German learning children diagnosed with SLI to typically developing children matched on age and socioeconomic status (SES). One week later, children with SLI…

  13. Repeatability of Objective Measurements of Linear Udder and Body ...

    African Journals Online (AJOL)

    The objective of this study was to estimates the repeatability of objective measurements on linear udder and body conformation traits and to evaluate the objectivity of the measurements in Friesian x Bunaji cows. Data from 50 (F1) Frisian X Bunaji cows collected between 2007 and 2008 at the Dairy Research Farm of the ...

  14. A General Model for Repeated Audit Controls Using Monotone Subsampling

    NARCIS (Netherlands)

    Raats, V.M.; van der Genugten, B.B.; Moors, J.J.A.

    2002-01-01

    In categorical repeated audit controls, fallible auditors classify sample elements in order to estimate the population fraction of elements in certain categories.To take possible misclassifications into account, subsequent checks are performed with a decreasing number of observations.In this paper a

  15. [Study on causes and treatment of repeated vulvovaginitis in girlhood].

    Science.gov (United States)

    Zhang, Di-kai; Li, Xiu-yun; Yang, Dong-zi; Kuang, Jian-quan

    2006-07-01

    To explore the causes and treatment of repeated vulvovaginitis in girlhood in order to improve its prevention and treatment. Fifty-one girls with repeated vulvovaginitis (age vulvovaginitis and 14 ones (27%) suffering from posterior recto-vaginal fistula with in 51 patients. Five girls (10%) were smitten with vulval ulcer and 3 ones (6%) had been were found with vaginal foreign bodies. One girl (2%) was smitten with adhesion of labia minora. The vaginal discharges taken from 21 girls were cultured. Seventeen cases found bacteria. The positive rate of bacteria culture in the 21 cases reached 81%, in which, E.coli accounted for 5 cases (24%), staphylococcus and streptococcus accounted for 3 cases (14%) respectively. Patients suffering from non-specific vulvovaginitis and vulval ulcer accepted external lotion, antibiotic ointment or combining with antibiotics. Patients suffering from posterior recto-vaginal fistula accepted fistulectomy. Three girls who found vaginal foreign bodies took out of foreign bodies by hysteroscope. Fifty-one girls all were cured after appropriate therapy. Vulvovaginitis is the most common gynecologic diagnosis in girlhood. The principal cause of repeated invasion is non-specific vulvovaginitis and the secondly one is posterior recto-vaginal fistula. It need overhaul during the diagnosis. It is very availability to use hysteroscopy and do bacteria culture + antibiotic sensitivity test for repeated pediatric vulvovaginitis.

  16. Reduction in gesture during the production of repeated references

    NARCIS (Netherlands)

    Hoetjes, M.W.; Koolen, R.M.F.; Goudbeek, M.B.; Krahmer, E.J.; Swerts, M.G.J.

    2015-01-01

    In dialogue, repeated references contain fewer words (which are also acoustically reduced) and fewer gestures than initial ones. In this paper, we describe three experiments studying to what extent gesture reduction is comparable to other forms of linguistic reduction. Since previous studies showed

  17. Participation behavior and social welfare in repeated task allocations

    NARCIS (Netherlands)

    Ye, Q.C.; Zhang, Y.

    2016-01-01

    Task allocation problems have focused on achieving one-shot optimality. In practice, many task allocation problems are of repeated nature, where the allocation outcome of previous rounds may influence the participation of agents in subsequent rounds, and consequently, the quality of the allocations

  18. Mononucleotide repeats are asymmetrically distributed in fungal genes

    NARCIS (Netherlands)

    Passel, van M.W.J.; Graaff, de L.H.

    2008-01-01

    ABSTRACT: BACKGROUND: Systematic analyses of sequence features have resulted in a better characterisation of the organisation of the genome. A previous study in prokaryotes on the distribution of sequence repeats, which are notoriously variable and can disrupt the reading frame in genes, showed that

  19. The breathing of webs under repeated partial edge loading

    Czech Academy of Sciences Publication Activity Database

    Škaloud, Miroslav; Zörnerová, Marie; Urushadze, Shota

    2012-01-01

    Roč. 40, č. 1 (2012), s. 463-468 E-ISSN 1877-7058. [Steel structures and bridges. Podbanske, 26.09.2012-28.09.2012] R&D Projects: GA ČR GA103/08/1340 Institutional support: RVO:68378297 Keywords : slender webs * breathing * fatigue limit state * design * repeated partial edge loading Subject RIV: JM - Building Engineering

  20. Increasing Positive Perceptions of Counseling: The Importance of Repeated Exposures

    Science.gov (United States)

    Kaplan, Scott A.; Vogel, David L.; Gentile, Douglas A.; Wade, Nathaniel G.

    2012-01-01

    This study assesses the effectiveness of repeated exposures to a video intervention based on the Elaboration Likelihood Model. The video was designed to increase help-seeking attitudes and perceptions of peer norms and to decrease the stigma associated with seeking counseling. Participants were 290 undergraduates who were randomly assigned to a…