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Sample records for abundance predict tick-borne

  1. Tick-Borne Encephalitis (TBE)

    Science.gov (United States)

    ... Search The CDC Cancel Submit Search The CDC Tick-borne Encephalitis (TBE) Note: Javascript is disabled or ... CDC.gov . Recommend on Facebook Tweet Share Compartir Tick-borne encephalitis, or TBE, is a human viral ...

  2. Effects of Climate Change on Ticks and Tick-Borne Diseases in Europe

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    J. S. Gray

    2009-01-01

    Full Text Available Zoonotic tick-borne diseases are an increasing health burden in Europe and there is speculation that this is partly due to climate change affecting vector biology and disease transmission. Data on the vector tick Ixodes ricinus suggest that an extension of its northern and altitude range has been accompanied by an increased prevalence of tick-borne encephalitis. Climate change may also be partly responsible for the change in distribution of Dermacentor reticulatus. Increased winter activity of  I. ricinus is probably due to warmer winters and a retrospective study suggests that hotter summers will change the dynamics and pattern of seasonal activity, resulting in the bulk of the tick population becoming active in the latter part of the year. Climate suitability models predict that eight important tick species are likely to establish more northern permanent populations in a climate-warming scenario. However, the complex ecology and epidemiology of such tick-borne diseases as Lyme borreliosis and tick-borne encephalitis make it difficult to implicate climate change as the main cause of their increasing prevalence. Climate change models are required that take account of the dynamic biological processes involved in vector abundance and pathogen transmission in order to predict future tick-borne disease scenarios.

  3. The Eco-Epidemiology of Tick-Borne Hemoparasitic Diseases Using Geographic Information Systems

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    Javad Rafinejad

    2013-12-01

    Full Text Available Background: Tick-borne diseases are of the most important diseases in the world including Iran. This survey was conducted to understand the eco-epidemiology of tick-borne hemoparasitic diseases in Qazvin province, Iran, using Geospatial Information System (GIS. Materials and Methods: DNA samples were extracted from livestock blood samples collected from different regions of Qazvin province. 18S rRNA-based PCR targeted Theileria/ Babesia species were done. Initial parameters for mapping the local tick-borne hemoparasitic diseases and raster files were obtained from Iran Meteorological Organization and Iranian Space Agency. Mapping of the parameters in relation to prevalence of these diseases were done. Statistical analysis was used for weighting parameters ranking and predicting spatial distribution in different climatic zones. Results: Vapor pressure, precipitation, and altitude are of several environmental factors correlated with tick abundances. Based on the generated maps and the results of this survey, some predicting results could be used for predicting tick-borne diseases and their control. 9.7% of ruminant blood samples (N=16 were infected with protozoa pathogens from the genera Theileria and all of the specimens were negative regarding to Babesia genera. Conclusion: Results showed that prediction of a very high prevalence of Theileria/ Babesia species and mapping endangered area is possible in different parts of Iran. Based on the environmental conditions, key factors exist for host-seeking and range expansion of ticks.

  4. Tick-Borne Diseases: The Big Two

    Science.gov (United States)

    ... Ticks and Diseases Tick-borne Diseases: The Big Two Past Issues / Spring - Summer 2010 Table of Contents ... muscle pain. The red-spotted rash usually happens 2 to 5 days after the fever begins. Antibiotics ...

  5. Revisiting the Clinal Concept of Evolution and Dispersal for the Tick-Borne Flaviviruses by Using Phylogenetic and Biogeographic Analyses

    OpenAIRE

    Heinze, D. M.; Gould, E A; Forrester, N. L.

    2012-01-01

    Tick-borne flaviviruses (TBF) are widely dispersed across Africa, Europe, Asia, Oceania, and North America, and some present a significant threat to human health. Seminal studies on tick-borne encephalitis viruses (TBEV), based on partial envelope gene sequences, predicted a westward clinal pattern of evolution and dispersal across northern Eurasia, terminating in the British Isles. We tested this hypothesis using all available full-length open reading frame (ORF) TBF sequences. Phylogenetic ...

  6. Equine tick-borne infections in the Netherlands

    NARCIS (Netherlands)

    Butler, C.M.

    2012-01-01

    This thesis focuses on the emergence and establishment of equine tick-borne infections in the Netherlands, with particular attention to their diagnosis, clinical relevance and treatment. Four tick-borne agents (Borrelia burgdorferi, Theileria equi, Babesia caballi and Anaplasma phagocytophilum) appe

  7. Molecular detection of tick-borne pathogens in Ixodes ricinus from Moldova collected in 1960.

    Science.gov (United States)

    Movila, Alexandru; Toderas, Ion; Uspenskaia, Inga; Conovalov, Jurii

    2013-06-01

    This study is the first report about the prevalence of tick-borne pathogens, as well as their (co-)infection rates, in the museum-archived I. ricinus female ticks collected in Moldova in 1960. A total of 16.7% (21/126) ticks was mono-infected. Borrelia burgdorferi sensu stricto was revealed as the most abundant species (4.8%) followed by B. garinii (1.6%), B. afzelii (0.8%), B. valaisiana (0.8%), and B. lusitaniae (0.8%). DNA of Rickettsia helvetica (2.4%), R. monacensis (2.4%), Anaplasma phagocytophilum (2.4%), 'Candidatus Neoehrlichia mikurensis' (0.8%), and Babesia microti (0.8%) were also detected, indicating the occurrence of these emerging tick-borne microorganisms in Moldova since 1960 at least. In this study, we detected a co-infection (0.8%; 1/126 tested ticks) between B. microti and R. helvetica. Additional investigations are warranted to further characterize a historical snapshot of the distribution of tick-borne pathogens in Europe.

  8. Tick-borne infections in human and animal population worldwide

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    José Brites-Neto

    2015-03-01

    Full Text Available The abundance and activity of ectoparasites and its hosts are affected by various abiotic factors, such as climate and other organisms (predators, pathogens and competitors presenting thus multiples forms of association (obligate to facultative, permanent to intermittent and superficial to subcutaneous developed during long co-evolving processes. Ticks are ectoparasites widespread globally and its eco epidemiology are closely related to the environmental conditions. They are obligatory hematophagous ectoparasites and responsible as vectors or reservoirs at the transmission of pathogenic fungi, protozoa, viruses, rickettsia and others bacteria during their feeding process on the hosts. Ticks constitute the second vector group that transmit the major number of pathogens to humans and play a role primary for animals in the process of diseases transmission. Many studies on bioecology of ticks, considering the information related to their population dynamics, to the host and the environment, comes possible the application and efficiency of tick control measures in the prevention programs of vector-borne diseases. In this review were considered some taxonomic, morphological, epidemiological and clinical fundamental aspects related to the tick-borne infections that affect human and animal populations.

  9. Tick vaccines and the transmission of tick-borne pathogens.

    Science.gov (United States)

    de la Fuente, J; Kocan, K M; Blouin, E F

    2007-08-01

    Ticks transmit pathogens that cause diseases which greatly impact both human and animal health. Vaccines developed against Boophilus spp. using Bm86 and Bm95 tick gut antigens demonstrated the feasibility of using vaccines for control of tick infestations. These vaccines also reduced transmission of tick-borne pathogens by decreasing exposure of susceptible hosts to ticks. The recently discovered tick antigens, 64P putative cement protein and subolesin involved in the regulation of tick feeding and reproduction, were also shown to reduce tick infestations. These antigens, together with the TROSPA receptor for Burrelia burgdorferi OspA were effective against tick-borne pathogens by reducing the infection levels in ticks and/or the transmission of the pathogen. Development of a vaccine targeted at both the tick vector and pathogen would contribute greatly to the control of tick infestations and the transmission of tick-borne diseases. These results have demonstrated that tick vaccines can be developed for control tick infestations and show promise for the prevention of the transmission of tick-borne pathogens. PMID:17682852

  10. Clinico-epidemiologichesky aspects of the mixed tick-borne infections in the endemic region

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    E. S. Aleshkovskaya

    2013-01-01

    Full Text Available Detection of clinico-epidemiological features of the mixed tick-borne infections – tick-borne Lyme disease and a human granulocytic anaplasmosis was the purpose of the conducted research. During the spring – summer period 146 patients with tick-borne borreliosis were surveyed. As a result at 45 (30,82% patients authentically diagnosed the mixed tick-borne infection. Features of clinical manifestations of a mixed tick-borne infection revealed: catarrhal phenomena (20%, liver defeats (33%, nephros (31, 7%, frequent secondary erythems (20%. Changes in haemogram defined: thrombocytopenia (42,2%, anemia (20%, leukopenia (13,3%.

  11. Of ticks, mice and men - shaping the ecology of tick-borne pathogens in Baden-Württemberg

    OpenAIRE

    Littwin, Nina-Vanessa

    2016-01-01

    Ticks cause more vector-borne diseases than any other blood-feeding arthropod in Europe; and their abundance is increasing. Influential US studies show that small mammals are key hosts regulating ticks and tick-borne pathogens (TBP), serving as blood meal hosts and TBP reservoirs. The relevance of these studies to Europe is, however, unknown. Therefore, my aim was the determination of the relative influence of small mammal hosts and environmental factors on the dynamics of ticks and TBPs in BW.

  12. Tick-borne encephalitis virus infection in humans

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    Hrnjaković-Cvjetković Ivana

    2016-01-01

    Full Text Available Introduction. Tick-borne meningoencephalitis virus is a flavivirus that causes the most important vector-borne central nervous system infection in many countries of Europe and Asia. There are three subtypes of tick-borne encephalitis virus: European, Siberian and the Far-Eastern subtype. Transmission. In endemic areas, the virus remains in transmissive cycles between Ixodes ticks and small rodents. Clinical picture. In most cases (70−98% infection goes asymptomatically. In about one-third of meningitis cases, meningoencephalitis or meningomyelitis is developed. Postencephalytic syndrome may be the complication of the infection, presenting with neurological symptoms. Diagnosis. Etiologic diagnosis of tick-borne meningoencephalitis is only made on basis of laboratory analyses. Reverse transcription-polymerase chain reaction is used for determining the presence of virus in the blood and cerebrospinal fluid. Antibodies in blood and cerebrospinal fluid can be detected by serological tests. Prevention. The most efficient way to control this potentially severe disease with possible serious long-term consequences is vaccination. It should be recommended to persons who live or travel to endemic areas. Conclusion. In Serbia, tick-borne encephalitis virus infection belongs to the list of reportable diseases; however, there are no reported cases because the diagnostics is not performed routinely. We believe that the significance of this zoonosis must be examined in our country and some of its parts because of preliminary positive serological findings found out in Vojvodina as well as because of reported cases in neighboring countries such as Hungary and Croatia and its worldwide distribution.

  13. Epidemiology of tick-borne borreliosis in Morocco

    OpenAIRE

    Diatta, Georges; Souidi, Yassine; Granjon, Laurent; Arnathau, Céline; Durand, Patrick; Chauvancy, Gilles; Mané, Youssouph; Sarih, M'Hammed; BELGHYTI, Driss; Renaud, François; Trape, Jean-François

    2012-01-01

    Background: The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. Methodology/Principal Findings: Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF ...

  14. Approaches towards tick and tick-borne diseases control

    OpenAIRE

    Ana Domingos; Sandra Antunes; Lara Borges; Virgilio Estolio do Rosario

    2013-01-01

    Ticks are obligate haematophagous ectoparasites of wild and domestic animals as well as humans, considered to be second worldwide to mosquitoes as vectors of human diseases. Tick-borne diseases are responsible worldwide for great economic losses in terms of mortality and morbidity of livestock animals. This review concerns to the different tick and tick-parasites control methods having a major focus on vaccines. Control of tick infestations has been mainly based on the use of acaricides, a co...

  15. Life history and demographic drivers of reservoir competence for three tick-borne zoonotic pathogens.

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    Richard S Ostfeld

    Full Text Available Animal and plant species differ dramatically in their quality as hosts for multi-host pathogens, but the causes of this variation are poorly understood. A group of small mammals, including small rodents and shrews, are among the most competent natural reservoirs for three tick-borne zoonotic pathogens, Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, in eastern North America. For a group of nine commonly-infected mammals spanning >2 orders of magnitude in body mass, we asked whether life history features or surrogates for (unknown encounter rates with ticks, predicted reservoir competence for each pathogen. Life history features associated with a fast pace of life generally were positively correlated with reservoir competence. However, a model comparison approach revealed that host population density, as a proxy for encounter rates between hosts and pathogens, generally received more support than did life history features. The specific life history features and the importance of host population density differed somewhat between the different pathogens. We interpret these results as supporting two alternative but non-exclusive hypotheses for why ecologically widespread, synanthropic species are often the most competent reservoirs for multi-host pathogens. First, multi-host pathogens might adapt to those hosts they are most likely to experience, which are likely to be the most abundant and/or frequently bitten by tick vectors. Second, species with fast life histories might allocate less to certain immune defenses, which could increase their reservoir competence. Results suggest that of the host species that might potentially be exposed, those with comparatively high population densities, small bodies, and fast pace of life will often be keystone reservoirs that should be targeted for surveillance or management.

  16. Tick vaccines and the control of tick-borne pathogens.

    Science.gov (United States)

    Merino, Octavio; Alberdi, Pilar; Pérez de la Lastra, José M; de la Fuente, José

    2013-01-01

    Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years resulting in greater interest in the study of tick-host-pathogen interactions. Advances in vector and pathogen genomics and proteomics have moved forward our knowledge of the vector-pathogen interactions that take place during the colonization and transmission of arthropod-borne microbes. Tick-borne pathogens adapt from the vector to the mammalian host by differential gene expression thus modulating host processes. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce tick feeding and reproduction, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, we review the tick-protective antigens that have been identified for the formulation of tick vaccines and the effect of these vaccines on the control of tick-borne pathogens.

  17. Climate change, biodiversity, ticks and tick-borne diseases: The butterfly effect.

    Science.gov (United States)

    Dantas-Torres, Filipe

    2015-12-01

    We have killed wild animals for obtaining food and decimated forests for many reasons. Nowadays, we are burning fossil fuels as never before and even exploring petroleum in deep waters. The impact of these activities on our planet is now visible to the naked eye and the debate on climate change is warming up in scientific meetings and becoming a priority on the agenda of both scientists and policy decision makers. On the occasion of the Impact of Environmental Changes on Infectious Diseases (IECID) meeting, held in the 2015 in Sitges, Spain, I was invited to give a keynote talk on climate change, biodiversity, ticks and tick-borne diseases. The aim of the present article is to logically extend my rationale presented on the occasion of the IECID meeting. This article is not intended to be an exhaustive review, but an essay on climate change, biodiversity, ticks and tick-borne diseases. It may be anticipated that warmer winters and extended autumn and spring seasons will continue to drive the expansion of the distribution of some tick species (e.g., Ixodes ricinus) to northern latitudes and to higher altitudes. Nonetheless, further studies are advocated to improve our understanding of the complex interactions between landscape, climate, host communities (biodiversity), tick demography, pathogen diversity, human demography, human behaviour, economics, and politics, also considering all ecological processes (e.g., trophic cascades) and other possible interacting effects (e.g., mutual effects of increased greenhouse gas emissions and increased deforestation rates). The multitude of variables and interacting factors involved, and their complexity and dynamism, make tick-borne transmission systems beyond (current) human comprehension. That is, perhaps, the main reason for our inability to precisely predict new epidemics of vector-borne diseases in general. PMID:26835253

  18. Climate change, biodiversity, ticks and tick-borne diseases: The butterfly effect

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    Filipe Dantas-Torres

    2015-12-01

    Full Text Available We have killed wild animals for obtaining food and decimated forests for many reasons. Nowadays, we are burning fossil fuels as never before and even exploring petroleum in deep waters. The impact of these activities on our planet is now visible to the naked eye and the debate on climate change is warming up in scientific meetings and becoming a priority on the agenda of both scientists and policy decision makers. On the occasion of the Impact of Environmental Changes on Infectious Diseases (IECID meeting, held in the 2015 in Sitges, Spain, I was invited to give a keynote talk on climate change, biodiversity, ticks and tick-borne diseases. The aim of the present article is to logically extend my rationale presented on the occasion of the IECID meeting. This article is not intended to be an exhaustive review, but an essay on climate change, biodiversity, ticks and tick-borne diseases. It may be anticipated that warmer winters and extended autumn and spring seasons will continue to drive the expansion of the distribution of some tick species (e.g., Ixodes ricinus to northern latitudes and to higher altitudes. Nonetheless, further studies are advocated to improve our understanding of the complex interactions between landscape, climate, host communities (biodiversity, tick demography, pathogen diversity, human demography, human behaviour, economics, and politics, also considering all ecological processes (e.g., trophic cascades and other possible interacting effects (e.g., mutual effects of increased greenhouse gas emissions and increased deforestation rates. The multitude of variables and interacting factors involved, and their complexity and dynamism, make tick-borne transmission systems beyond (current human comprehension. That is, perhaps, the main reason for our inability to precisely predict new epidemics of vector-borne diseases in general.

  19. Stability of a tick-borne flavivirus in milk

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    Danielle K Offerdahl

    2016-05-01

    Full Text Available The tick-borne flaviviruses (TBFV occur worldwide and the tick-borne encephalitis virus members of the group (TBEV often cause severe, debilitating neurological disease in humans. Although the primary route of infection is through the bite of an infected tick, alimentary infection through the consumption of TBEV-contaminated dairy products is also well-documented and is responsible for some disease in endemic areas. Experimental infection of goats, cattle, and sheep with TBEV shows that virus can be excreted in the milk of infected animals. Additionally, the virus remains infectious after exposure to low pH levels, similar to those found in the stomach. To evaluate survival of virus in milk, we studied the stability of the BSL-2 TBFV, Langat virus, in unpasteurized goat milk over time and after different thermal treatments. Virus was stable in milk maintained under refrigeration conditions; however, there was a marked reduction in virus titer after incubation at room temperature. High temperature, short time pasteurization protocols completely inactivated the virus. Interestingly, simulation of a typical thermal regime utilized for cheese did not completely inactivate the virus in milk. These findings stress the importance of proper milk handling and pasteurization processes in areas endemic for TBEV.

  20. High-throuhgput screening of tick-borne pathogens in Europe

    NARCIS (Netherlands)

    Michelet, L.; Delannoy, S.; Devillers, E.; Umhang, G.; Aspan, A.; Juremalm, M.; Chirico, J.; Wal, van der F.J.; Sprong, H.; Boye Pihl, T.P.; Klitgaard, K.; Bodker, R.; Fach, P.; Moutailler, S.

    2014-01-01

    Due to increased travel, climatic, and environmental changes, the incidence of tick-borne disease in both humans and animals is increasing throughout Europe. Therefore, extended surveillance tools are desirable. To accurately screen tick-borne pathogens (TBPs), a large scale epidemiological study wa

  1. Transport of Ixodid ticks and tick-borne pathogens by migratory birds.

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    Gunnar eHasle

    2013-09-01

    Full Text Available Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be most important for harboring ticks. Birds can easily cross barriers, like fences, mountains, glaciers, desserts and oceans, which would stop mammals, and they can move much faster than the wingless hosts. Birds can potentially transport tick-borne pathogens by transporting infected ticks, by being infected with tick-borne pathogens and transmit the pathogens to the ticks, and possibly act as hosts for transfer of pathogens between ticks through co-feeding. Knowledge of the bird migration routes and of the spatial distribution of tick species and tick-borne pathogens is crucial for understanding the possible impact of birds as spreaders of ticks and tick-borne pathogens. Successful colonization of new tick species or introduction of new tick-borne pathogens will depend on suitable climate, vegetation and hosts. Although it has never been demonstrated that a new tick species, or a new tick pathogen, actually has been established in a new locality after being seeded there by birds, evidence strongly suggests that this could occur.

  2. First human case of tick-borne encephalitis virus infection acquired in the Netherlands, July 2016.

    Science.gov (United States)

    de Graaf, Joris A; Reimerink, Johan H J; Voorn, G Paul; Bij de Vaate, Elisabeth A; de Vries, Ankje; Rockx, Barry; Schuitemaker, Alie; Hira, Vishal

    2016-08-18

    In July 2016, the first autochthonous case of tick-borne encephalitis was diagnosed in the Netherlands, five days after a report that tick-borne encephalitis virus (TBEV) had been found in Dutch ticks. A person in their 60s without recent travel history suffered from neurological symptoms after a tick bite. TBEV serology was positive and the tick was positive in TBEV qRT-PCR. TBEV infection should be considered in patients with compatible symptoms in the Netherlands. PMID:27562931

  3. Transport of ixodid ticks and tick-borne pathogens by migratory birds

    OpenAIRE

    Hasle, Gunnar

    2013-01-01

    Birds, particularly passerines, can be parasitized by Ixodid ticks, which may be infected with tick-borne pathogens, like Borrelia spp., Babesia spp., Anaplasma, Rickettsia/Coxiella, and tick-borne encephalitis virus. The prevalence of ticks on birds varies over years, season, locality and different bird species. The prevalence of ticks on different species depends mainly on the degree of feeding on the ground. In Europe, the Turdus spp., especially the blackbird, Turdus merula, appears to be...

  4. Isolation and characterization of tick-borne encephalitis virus from Ixodes persulcatus in Mongolia in 2012

    OpenAIRE

    Muto, Memi; Bazartseren, Boldbaatar; Tsevel, Bazartseren; Dashzevge, Erdenechimeg; Yoshii, Kentaro; Kariwa, Hiroaki

    2015-01-01

    Tick-borne encephalitis virus (TBEV) is a zoonotic virus belonging to the genus Flavivirus, in the family Flaviviridae. The virus, which is endemic in Europe and northern parts of Asia, causes severe encephalitis. Tick-borne encephalitis (TBE) has been reported in Mongolia since the 1980s, but details about the biological characteristics of the endemic virus are lacking. In this study, 680 ticks (Ixodes persulcatus) were collected in Selenge aimag, northern Mongolia, in 2012. Nine Mongolian T...

  5. Tick-borne ehrlichiosis infection in human beings

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    S. Ganguly

    2008-11-01

    Full Text Available Human monocytic ehrlichiosis is a tick-borne infectious disease transmitted by several tick species, especially Amblyomma spp caused by Ehrlichia chaffeensis. E. chaffeensis is an obligatory intracellular, tick-transmitted bacterium that is maintained in nature in a cycle involving at least one and perhaps several vertebrate reservoir hosts. Two additional Ehrlichia spp, Anaplasma (formerly Ehrlichia phagocytophila (the agent of human granulocytic ehrlichiosis [HGE] and E. ewingii (a cause of granulocytic ehrlichiosis in dogs act as human pathogens. Human E. chaffeensis infections have generally been reported in North America, Asia and Europe, but recently human cases have been reported in Brazil only. Human monocytic ehrlichiosis is diagnosed by demonstration of a four-fold or greater change in antibody titer to E. chaffeensis antigen by IFA in paired serum samples, or a positive PCR assay and confirmation of E. chaffeensis DNA, or identification of morulae in leukocytes and a positive IFA titer to E. chaffeensis antigen, or immunostaining of E. chaffeensis antigen in a biopsy or autopsy sample, or culture of E. chaffeensis from a clinical specimen.

  6. Approaches towards tick and tick-borne diseases control

    Directory of Open Access Journals (Sweden)

    Ana Domingos

    2013-04-01

    Full Text Available Ticks are obligate haematophagous ectoparasites of wild and domestic animals as well as humans, considered to be second worldwide to mosquitoes as vectors of human diseases. Tick-borne diseases are responsible worldwide for great economic losses in terms of mortality and morbidity of livestock animals. This review concerns to the different tick and tick-parasites control methods having a major focus on vaccines. Control of tick infestations has been mainly based on the use of acaricides, a control measure with serious drawbacks, as responsible for the contamination of milk and meat products, as a selective factor for acaricide-resistant ticks and as an environmental contaminant. Research on alternatives to the use of acaricides is strongly represented by tick vaccines considered a more cost-effective and environmentally safe strategy. Vaccines based on the Bm86 tick antigen were used in the first commercially available cattle tick vaccines and showed good results in reducing tick numbers, affecting weight and reproductive performance of female ticks which resulted in reduction of cattle tick populations over time and consequently lower reduction of the pathogen agents they carry.

  7. Approaches towards tick and tick-borne diseases control.

    Science.gov (United States)

    Domingos, Ana; Antunes, Sandra; Borges, Lara; Rosário, Virgílio Estólio do

    2013-01-01

    Ticks are obligate haematophagous ectoparasites of wild and domestic animals as well as humans, considered to be second worldwide to mosquitoes as vectors of human diseases. Tick-borne diseases are responsible worldwide for great economic losses in terms of mortality and morbidity of livestock animals. This review concerns to the different tick and tick-parasites control methods having a major focus on vaccines. Control of tick infestations has been mainly based on the use of acaricides, a control measure with serious drawbacks, as responsible for the contamination of milk and meat products, as a selective factor for acaricide-resistant ticks and as an environmental contaminant. Research on alternatives to the use of acaricides is strongly represented by tick vaccines considered a more cost-effective and environmentally safe strategy. Vaccines based on the Bm86 tick antigen were used in the fi rst commercially available cattle tick vaccines and showed good results in reducing tick numbers, affecting weight and reproductive performance of female ticks which resulted in reduction of cattle tick populations over time and consequently lower reduction of the pathogen agents they carry. PMID:23559344

  8. Study of the climatic change impact on vector-borne diseases in West Africa: the case of tick-borne borreliosis and malaria

    International Nuclear Information System (INIS)

    Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)

  9. Pattern of tick aggregation on mice: larger than expected distribution tail enhances the spread of tick-borne pathogens.

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    Luca Ferreri

    2014-11-01

    Full Text Available The spread of tick-borne pathogens represents an important threat to human and animal health in many parts of Eurasia. Here, we analysed a 9-year time series of Ixodes ricinus ticks feeding on Apodemus flavicollis mice (main reservoir-competent host for tick-borne encephalitis, TBE sampled in Trentino (Northern Italy. The tail of the distribution of the number of ticks per host was fitted by three theoretical distributions: Negative Binomial (NB, Poisson-LogNormal (PoiLN, and Power-Law (PL. The fit with theoretical distributions indicated that the tail of the tick infestation pattern on mice is better described by the PL distribution. Moreover, we found that the tail of the distribution significantly changes with seasonal variations in host abundance. In order to investigate the effect of different tails of tick distribution on the invasion of a non-systemically transmitted pathogen, we simulated the transmission of a TBE-like virus between susceptible and infective ticks using a stochastic model. Model simulations indicated different outcomes of disease spreading when considering different distribution laws of ticks among hosts. Specifically, we found that the epidemic threshold and the prevalence equilibria obtained in epidemiological simulations with PL distribution are a good approximation of those observed in simulations feed by the empirical distribution. Moreover, we also found that the epidemic threshold for disease invasion was lower when considering the seasonal variation of tick aggregation.

  10. Postinfectious syndrome of convalescentsixodes tick-borne borreliosis

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    O. N. Sumlivaya

    2014-01-01

    Full Text Available The aim: to study the psycho-vegetative status of the quantitative contents of serotonin in blood platelets in patients after the Ixodes tick-borne borreliosis, to evaluate the clinical efficiency treatment by adamantilfenilamin of postinfection asthenia.Materials and methods: there was clinical supervision and inspection conducted of 118 convalescents borreliosis after a course of inpatient treatment. All patients were examined using psychovegetative tests. Platelet serotonin concentration levels were measured by enzyme immunoassay. For the treatment of postinfectious asthenia 36 convalescents received adamantilbromfenilamin in a dose of 100 mg for 25 days.Results: when tested convalescents marked change in indicators of emotional and personality disorders. Quantitative study of blood platelet serotonin content revealed a significant decrease in this indicator relative to control values. Study the correlations between obtained when testing the psycho-emotional parameters and platelet serotonin levels showed a negative correlation between serotonin and an indicator of reactive anxiety (R = -0,81, p <0,05. To correct these violations convalescents with severe asthenia postinfection were treated adamantilfenilamin. Established clinical efficacy contributing to the improvement of the quality of life.Conclusion: the research of neurotransmitter serotonin in patients during the convalescence period after borreliosis possible to evaluate the extent of potential damage to the nervous tissue in the inflammatory process and its involvement in the formation of anxiety and depressive symptoms. adamantilbromfenilamin can be recommended for rehabilitation patients with residual effects in the form of postinfectious asthenia.

  11. Epidemiology of tick-borne borreliosis in Morocco.

    Directory of Open Access Journals (Sweden)

    Georges Diatta

    Full Text Available BACKGROUND: The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. METHODOLOGY/PRINCIPAL FINDINGS: Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF in febrile patients in Kenitra district. The prevalence of Borrelia infections was assessed by nested PCR amplification in ticks and the brain tissue of small mammals, and by evaluation of thick blood films in patients. A high proportion of burrows were infested with ticks of the O. erraticus complex in all regions of Morocco, with a mean of 39.5% for the whole country. Borrelia infections were found in 39/382 (10.2% of the ticks and 12/140 (8.6% of the rodents and insectivores studied by PCR amplification, and 102 patients tested positive by thick blood film. Five small mammalian species were found infected: Dipodillus campestris, Meriones shawi, Gerbillus hoogstrali, Gerbillus occiduus and Atelerix algirus. Three Borrelia species were identified in ticks and/or rodents: B. hispanica, B. crocidurae and B. merionesi. CONCLUSIONS/SIGNIFICANCE: Tick populations belonging to O. erraticus complex are widely distributed in Morocco and a high proportion of ticks and small mammals are infected by Borrelia species. Although rarely diagnosed, TBRF may be a common cause of morbidity in all regions of Morocco.

  12. Nucleoside Inhibitors of Tick-Borne Encephalitis Virus

    Science.gov (United States)

    Eyer, Luděk; Valdés, James J.; Gil, Victor A.; Nencka, Radim; Hřebabecký, Hubert; Šála, Michal; Salát, Jiří; Černý, Jiří; Palus, Martin; De Clercq, Erik

    2015-01-01

    Tick-borne encephalitis virus (TBEV) is a leading cause of human neuroinfections in Europe and Northeast Asia. There are no antiviral therapies for treating TBEV infection. A series of nucleoside analogues was tested for the ability to inhibit the replication of TBEV in porcine kidney cells and human neuroblastoma cells. The interactions of three nucleoside analogues with viral polymerase were simulated using advanced computational methods. The nucleoside analogues 7-deaza-2′-C-methyladenosine (7-deaza-2′-CMA), 2′-C-methyladenosine (2′-CMA), and 2′-C-methylcytidine (2′-CMC) inhibited TBEV replication. These compounds showed dose-dependent inhibition of TBEV-induced cytopathic effects, TBEV replication (50% effective concentrations [EC50]of 5.1 ± 0.4 μM for 7-deaza-2′-CMA, 7.1 ± 1.2 μM for 2′-CMA, and 14.2 ± 1.9 μM for 2′-CMC) and viral antigen production. Notably, 2′-CMC was relatively cytotoxic to porcine kidney cells (50% cytotoxic concentration [CC50] of ∼50 μM). The anti-TBEV effect of 2′-CMA in cell culture diminished gradually after day 3 posttreatment. 7-Deaza-2′-CMA showed no detectable cellular toxicity (CC50 > 50 μM), and the antiviral effect in culture was stable for >6 days posttreatment. Computational molecular analyses revealed that compared to the other two compounds, 7-deaza-2′-CMA formed a large cluster near the active site of the TBEV polymerase. High antiviral activity and low cytotoxicity suggest that 7-deaza-2′-CMA is a promising candidate for further investigation as a potential therapeutic agent in treating TBEV infection. PMID:26124166

  13. Epidemiology of Tick-Borne Borreliosis in Morocco

    Science.gov (United States)

    Diatta, Georges; Souidi, Yassine; Granjon, Laurent; Arnathau, Céline; Durand, Patrick; Chauvancy, Gilles; Mané, Youssouph; Sarih, M'hammed; Belghyti, Driss; Renaud, François; Trape, Jean-François

    2012-01-01

    Background The presence in Morocco of Argasid ticks of the Ornithodoros erraticus complex, the vector of tick-borne relapsing fever (TBRF) in North Africa, has been known since 1919, but the disease is rarely diagnosed and few epidemiological data are available. Methodology/Principal Findings Between 2006 and 2011, we investigated the presence of Ornithodoros ticks in rodent burrows in 34 sites distributed across Morocco. We also collected small mammals in 10 sites and we investigated TBRF in febrile patients in Kenitra district. The prevalence of Borrelia infections was assessed by nested PCR amplification in ticks and the brain tissue of small mammals, and by evaluation of thick blood films in patients. A high proportion of burrows were infested with ticks of the O. erraticus complex in all regions of Morocco, with a mean of 39.5% for the whole country. Borrelia infections were found in 39/382 (10.2%) of the ticks and 12/140 (8.6%) of the rodents and insectivores studied by PCR amplification, and 102 patients tested positive by thick blood film. Five small mammalian species were found infected: Dipodillus campestris, Meriones shawi, Gerbillus hoogstrali, Gerbillus occiduus and Atelerix algirus. Three Borrelia species were identified in ticks and/or rodents: B. hispanica, B. crocidurae and B. merionesi. Conclusions/Significance Tick populations belonging to O. erraticus complex are widely distributed in Morocco and a high proportion of ticks and small mammals are infected by Borrelia species. Although rarely diagnosed, TBRF may be a common cause of morbidity in all regions of Morocco. PMID:23029574

  14. Tick-borne encephalitis virus infects rat astrocytes but does not affect their viability.

    Directory of Open Access Journals (Sweden)

    Maja Potokar

    Full Text Available Tick-borne encephalitis virus (TBEV causes one of the most dangerous human neuroinfections in Europe and Asia. To infect neurons it must cross the blood-brain-barrier (BBB, and presumably also cells adjacent to the BBB, such as astrocytes, the most abundant glial cell type. However, the knowledge about the viral infection of glial cells is fragmental. Here we studied whether TBEV infects rat astrocytes. Rats belong to an animal group serving as a TBEV amplifying host. We employed high resolution quantitative fluorescence microscopy to investigate cell entry and cytoplasmic mobility of TBEV particles along with the effect on the cell cytoskeleton and cell survival. We report that infection of astrocytes with TBEV increases with time of exposure to TBEV and that with post-infection time TBEV particles gained higher mobility. After several days of infection actin cytoskeleton was affected, but cell survival was unchanged, indicating that rat astrocytes resist TBEV-mediated cell death, as reported for other mammalian cells. Therefore, astrocytes may present an important pool of dormant TBEV infections and a new target for therapeutic intervention.

  15. Tick-Borne Encephalitis Virus Infects Rat Astrocytes but Does Not Affect Their Viability

    Science.gov (United States)

    Potokar, Maja; Korva, Miša; Jorgačevski, Jernej; Avšič-Županc, Tatjana; Zorec, Robert

    2014-01-01

    Tick-borne encephalitis virus (TBEV) causes one of the most dangerous human neuroinfections in Europe and Asia. To infect neurons it must cross the blood-brain-barrier (BBB), and presumably also cells adjacent to the BBB, such as astrocytes, the most abundant glial cell type. However, the knowledge about the viral infection of glial cells is fragmental. Here we studied whether TBEV infects rat astrocytes. Rats belong to an animal group serving as a TBEV amplifying host. We employed high resolution quantitative fluorescence microscopy to investigate cell entry and cytoplasmic mobility of TBEV particles along with the effect on the cell cytoskeleton and cell survival. We report that infection of astrocytes with TBEV increases with time of exposure to TBEV and that with post-infection time TBEV particles gained higher mobility. After several days of infection actin cytoskeleton was affected, but cell survival was unchanged, indicating that rat astrocytes resist TBEV-mediated cell death, as reported for other mammalian cells. Therefore, astrocytes may present an important pool of dormant TBEV infections and a new target for therapeutic intervention. PMID:24465969

  16. [The cytokine profile in the acute period of tick-borne neuroinfections in children].

    Science.gov (United States)

    Poponnikova, T V; Bedareva, T Iu; Vakhrameeva, T N; Galieva, G Iu

    2010-01-01

    Clinical peculiarities and blood levels of several cytokines were studied in 199 children, aged from 1 to 15 years, in the acute period of different tick-borne infections. The mixed infection manifested itself by the more severe progression of general clinical presentations compared to monoinfections. Etiologically unspecific changes of blood concentrations of cytokines in the acute period of the disease were found. These data were associated with different clinical forms of tick-borne infections. The decrease in the interferon gamma production was associated with the most severe disease progression with focal nervous system disorders. The use of cycloferon as immune modulator in the complex therapy led to the increase in the interferon gamma level and the decrease of general clinical manifestations during tick-borne encephalitis and mixed infection.

  17. Tick-borne encephalitis: a retrospective study of clinical cases in Bornholm, Denmark

    DEFF Research Database (Denmark)

    Laursen, Kirsten; Knudsen, Jenny Dahl

    2003-01-01

    Tick-borne encephalitis (TBE) is caused by a flavivirus, tick-borne encephalitis virus (TBEV). For decades TBE has been known to cause disease in Bornholm, a Danish island. A retrospective study was performed to identify undiagnosed cases of TBE among patients hospitalized with signs and symptoms...... of meningitis or encephalitis in the 5 y period 1994-1999. This investigation revealed 5 new, and initially undiagnosed cases of TBE. In total, 14 cases of TBE were found in the 7 y period 1994-2000; 2 patients were tourists and 12 cases were inhabitants in Bornholm, giving an incidence of 3.81 per 100...

  18. Tick-borne disease preventive practices and perceptions in an endemic area.

    Science.gov (United States)

    Butler, Amber D; Sedghi, Tannaz; Petrini, Joann R; Ahmadi, Ramin

    2016-03-01

    Lyme disease is the most commonly reported vector-borne illness in the United States. Since the institution of Nationally Notifiable surveillance efforts for Lyme disease in the United States in 1991, there has been a consistent increase in the number of reported cases. Thus, the need for targeted prevention strategies is underscored. The purpose of this study was to investigate knowledge about tick-borne diseases as well as beliefs and practices related to a variety of personal tick-borne disease prevention methods among individuals in southwestern Connecticut, a Lyme disease-endemic area. Between June and September 2014, an anonymous questionnaire was administered to 275 participants through a point-of-contact convenience sample obtained at community events in southwestern Connecticut. The questionnaire assessed individuals' general knowledge about tick-borne diseases, performance of four selected tick-borne disease prevention methods, and perceived effectiveness and burdensomeness of those four behaviors. Some 80% of participants were female; median age was 55 years (IQR 45-64 years); 30% reported having been treated for a tick-borne illness and 50% reported a family member having been treated for a tick-borne illness. Overall, participants' knowledge of tick-borne diseases was poor; the average knowledge score was only 57% (SD 22.6%). The reported frequency of performing preventive behaviors was variable. The most commonly reported behavior was performing a tick check (68%); use of tick repellent was the least commonly reported behavior (38%). Those who were more knowledgeable about Lyme disease were more likely to perform tick checks but knowledge score was not significantly associated with any of the other three behaviors studied. Respondents largely believed preventive behaviors to be effective at reducing the risk of tick-borne diseases. Belief that a prevention behavior is effective was highly correlated with performing that behavior but perceived

  19. Tick-borne encephalitis virus in dogs - is this an issue?

    OpenAIRE

    Dobler Gerhard; Pfeffer Martin

    2011-01-01

    Abstract The last review on Tick-borne encephalitis (TBE) in dogs was published almost ten years ago. Since then, this zoonotic tick-borne arbovirus has been geographically spreading and emerging in many regions in Eurasia and continues to do so. Dogs become readily infected with TBE virus but they are accidental hosts not capable to further spread the virus. They seroconvert upon infection but they seem to be much more resistant to the clinical disease than humans. Apart from their use as se...

  20. The Burden of Tick-Borne Encephalitis in Disability-Adjusted Life Years (DALYs) for Slovenia

    NARCIS (Netherlands)

    Smit, Renata; Postma, Maarten J.

    2015-01-01

    Background Tick-borne encephalitis (TBE) presents an increasing burden in many parts of Europe, Asian Russia, Siberia, Asian former USSR and Far East. Incidence can be considered as one way to express the burden. A more comprehensive measure concerns disability-adjusted life years (DALYs), better ch

  1. Human Tick-Borne Encephalitis and Characterization of Virus from Biting Tick.

    Science.gov (United States)

    Henningsson, Anna J; Lindqvist, Richard; Norberg, Peter; Lindblom, Pontus; Roth, Anette; Forsberg, Pia; Bergström, Tomas; Överby, Anna K; Lindgren, Per-Eric

    2016-08-01

    We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity. PMID:27434395

  2. First detection of tick-borne "Candidatus Neoehrlichia mikurensis" in Denmark 2011

    DEFF Research Database (Denmark)

    Fertner, Mette Ely; Mølbak, Lars; Pihl, Thomas Peter Boye;

    2012-01-01

    This is the first reporting of the tick-borne zoonotic bacterium "Candidatus Neoehrlichia mikurensis" in Denmark. A total of 2,625 Ixodes ricinus ticks from 58 locations in Denmark were collected and analysed for "Ca. Neoehrlichia mikurensis". A nested PCR revealed the presence of the bacterium...

  3. Human Tick-Borne Encephalitis and Characterization of Virus from Biting Tick

    Science.gov (United States)

    Lindqvist, Richard; Norberg, Peter; Lindblom, Pontus; Roth, Anette; Forsberg, Pia; Bergström, Tomas; Överby, Anna K.; Lindgren, Per-Eric

    2016-01-01

    We report a case of human tick-borne encephalitis (TBE) in which the TBE virus was isolated from the biting tick. Viral growth and sequence were characterized and compared with those of a reference strain. Virus isolation from ticks from patients with TBE may offer a new approach for studies of epidemiology and pathogenicity. PMID:27434395

  4. Host specialisation in ticks and transmission of tick-borne diseases: a review

    Directory of Open Access Journals (Sweden)

    Karen Denise Mccoy

    2013-10-01

    Full Text Available Determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. The question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. Indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptations and that most ticks were specialists. Later work disputed this idea and suggested that ticks are largely limited by biogeographic conditions and tend to use all locally available host species. The work presented in this review suggests that the actual answer likely lies somewhere between these two extremes. Although recent observational studies support the view that phylogenetically diverse host species share ticks when found on similar ecological ranges, theory on host range evolution predicts that host specialisation should evolve in ticks given their life history characteristics. Contemporary work employing population genetic tools to examine host-associated population structure in several tick systems support this prediction and show that simple species records are not enough to determine whether a parasite is a true host generalist; host specialisation does evolve in ticks at local scales, but may not always lead to speciation. Ticks therefore seem to follow a pattern of being global generalists, local specialists. Given this, the notion of host range needs to be modified from an evolutionary perspective, where one simply counts the number of hosts used across the geographic distribution, to a more ecological view, where one considers host use at a local scale, if we are to better understand the circulation of tick-borne pathogens and exposure risks for humans and livestock.

  5. An attempt of rationalization of tick-borne disease prevention using a multifunctional container for Tick Twister ®

    Directory of Open Access Journals (Sweden)

    Barbara Oczko-Grzesik

    2013-12-01

    Full Text Available Ticks are reservoir and transmission vectors of many bacteria, viruses and parasites, which are pathogenic for humans. Early and correct tick removal is crucial as prevention of tick-borne diseases. The aim of the study is an attempt at rationalization of tick-borne disease prevention using a multifunctional container for Tick Twister®. In practice, it should enable people to use Tick Twister® in all circumstances contributing to the improvement of efficiency in tick-borne diseases prevention, and as a result, to a decrease in their frequency and after effects.

  6. Influence of the biotope on the tick infestation of cattle and on the tick-borne pathogen repertoire of cattle ticks in Ethiopia.

    Directory of Open Access Journals (Sweden)

    Sándor Hornok

    Full Text Available BACKGROUND: The majority of vector-borne infections occur in the tropics, including Africa, but molecular eco-epidemiological studies are seldom reported from these regions. In particular, most previously published data on ticks in Ethiopia focus on species distribution, and only a few molecular studies on the occurrence of tick-borne pathogens or on ecological factors influencing these. The present study was undertaken to evaluate, if ticks collected from cattle in different Ethiopian biotopes harbour (had access to different pathogens. METHODS: In South-Western Ethiopia 1032 hard ticks were removed from cattle grazing in three kinds of tick biotopes. DNA was individually extracted from one specimen of both sexes of each tick species per cattle. These samples were molecularly analysed for the presence of tick-borne pathogens. RESULTS: Amblyomma variegatum was significantly more abundant on mid highland, than on moist highland. Rhipicephalus decoloratus was absent from savannah lowland, where virtually only A. cohaerens was found. In the ticks Coxiella burnetii had the highest prevalence on savannah lowland. PCR positivity to Theileria spp. did not appear to depend on the biotope, but some genotypes were unique to certain tick species. Significantly more A. variegatum specimens were rickettsia-positive, than those of other tick species. The presence of rickettsiae (R. africae appeared to be associated with mid highland in case of A. variegatum and A. cohaerens. The low level of haemoplasma positivity seemed to be equally distributed among the tick species, but was restricted to one biotope type. CONCLUSIONS: The tick biotope, in which cattle are grazed, will influence not only the tick burden of these hosts, but also the spectrum of pathogens in their ticks. Thus, the presence of pathogens with alternative (non-tick-borne transmission routes, with transstadial or with transovarial transmission by ticks appeared to be associated with the biotope

  7. Tick-borne pathogens of potential zoonotic importance in the southern African Region

    Directory of Open Access Journals (Sweden)

    Simbarashe Chitanga

    2014-02-01

    Full Text Available The aim of this communication is to provide preliminary information on the tick-borne pathogens of potential zoonotic importance present in southern Africa, mainly focusing on their geographical distribution and host range, and to identify research gaps. The following tick-borne zoonoses have been reported to occur in southern Africa based mainly on case reports: Crimean–Congo haemorrhagic fever caused by Crimean–Congo haemorrhagic fever virus; ehrlichiosis caused by Ehrlichia ruminantium, Ehrlichia canis and Anaplasma phagocytophilum; babesiosis caused by Babesia microti; relapsing fever caused by Borrelia duttonii and rickettsioses caused by Rickettsia africae, Rickettsia aeschlimannii and Rickettsia conorii. The epidemiological factors influencing their occurrence are briefly reviewed.

  8. Tick-borne Relapsing Fever and Borrelia hermsii, Los Angeles County, California, USA

    Science.gov (United States)

    Raffel, Sandra J.; Schrumpf, Merry E.; Webster, Larry S.; Marques, Adriana R.; Spano, Robyn; Rood, Michael; Burns, Joe; Hu, Renjie

    2009-01-01

    The primary cause of tick-borne relapsing fever in western North America is Borrelia hermsii, a rodent-associated spirochete transmitted by the fast-feeding soft tick Ornithodoros hermsi. We describe a patient who had an illness consistent with relapsing fever after exposure in the mountains near Los Angeles, California, USA. The patient’s convalescent-phase serum was seropositive for B. hermsii but negative for several other vector-borne bacterial pathogens. Investigations at the exposure site showed the presence of O. hermsi ticks infected with B. hermsii and the presence of rodents that were seropositive for the spirochete. We determined that this tick-borne disease is endemic to the San Gabriel Mountains near the greater Los Angeles metropolitan area. PMID:19624916

  9. Non-systemic transmission of tick-borne diseases: A network approach

    Science.gov (United States)

    Ferreri, Luca; Bajardi, Paolo; Giacobini, Mario

    2016-10-01

    Tick-borne diseases can be transmitted via non-systemic (NS) transmission. This occurs when tick gets the infection by co-feeding with infected ticks on the same host resulting in a direct pathogen transmission between the vectors, without infecting the host. This transmission is peculiar, as it does not require any systemic infection of the host. The NS transmission is the main efficient transmission for the persistence of the tick-borne encephalitis virus in nature. By describing the heterogeneous ticks aggregation on hosts through a bipartite graphs representation, we are able to mathematically define the NS transmission and to depict the epidemiological conditions for the pathogen persistence. Despite the fact that the underlying network is largely fragmented, analytical and computational results show that the larger is the variability of the aggregation, and the easier is for the pathogen to persist in the population.

  10. Comparison of various ways of tick infection with the tick-borne encephalitis virus

    OpenAIRE

    VÝLETOVÁ, Eva

    2015-01-01

    The aim of the bachelor thesis was to compare various methods of Ixodes ricinus tick infection with the tick-borne encephalitis virus. For infection by immersion method, less virulent TBE virus strain Neudoerfl was used resulting in 5 % of infected ticks. Using more virulent strain Hypr provided 60 % of infected ticks. 75 % of ticks became infected with the Neudoerfl virus by capillary feeding. Infection of ticks by feeding on viraemic mice was unsuccessful. Applicability of tested methods fo...

  11. Survey for Hantaviruses, Tick-Borne Encephalitis Virus, and Rickettsia spp. in Small Rodents in Croatia

    OpenAIRE

    Svoboda, Petra; Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; MARGALETIĆ, JOSIP; Essbauer, Sandra

    2014-01-01

    In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunoflourescence ass...

  12. Tick-borne diseases of the USA: Ten things clinicians should know.

    Science.gov (United States)

    Buckingham, Steven C

    2015-06-01

    This article highlights critical aspects of the epidemiology, diagnosis, and management of tick-borne infections in children. Principles that apply broadly across the continental United States are emphasized, rather than details of each disease. Tick-borne infections are often confused with other, more common childhood illnesses, in part because of their nonspecific initial clinical findings and because patients are usually unaware of their preceding tick exposures. This is a problem, because delays in starting appropriate antibiotic therapy increase the likelihood of adverse outcomes from these infections, especially Rocky Mountain spotted fever (RMSF). For patients in whom RMSF is a reasonable diagnostic consideration, therapy should be started presumptively, without awaiting the results of confirmatory diagnostic tests. For both adults and children, doxycycline is the drug of choice for RMSF and other American rickettsial infections. Concerns over the potential toxicity of doxycycline in young children are unfounded. Similarly groundless is the belief in "chronic Lyme disease" as an explanation for persistent nonspecific complaints after completing antibiotic therapy for Lyme disease. Prevention of tick-borne infections rests on avoidance of tick-bites and prompt removal of attached ticks. When used appropriately, insect repellents containing DEET are safe and effective for preventing tick exposures.

  13. Inhibitors of tick-borne flavivirus reproduction from structure-based virtual screening.

    Science.gov (United States)

    Osolodkin, Dmitry I; Kozlovskaya, Liubov I; Dueva, Evgenia V; Dotsenko, Victor V; Rogova, Yulia V; Frolov, Konstantin A; Krivokolysko, Sergey G; Romanova, Ekaterina G; Morozov, Alexey S; Karganova, Galina G; Palyulin, Vladimir A; Pentkovski, Vladimir M; Zefirov, Nikolay S

    2013-09-12

    Flaviviruses form a large family of enveloped viruses affecting millions of people over the world. To date, no specific therapy was suggested for the infected people, making the treatment exclusively symptomatic. Several attempts were performed earlier for the design of fusion inhibitors for mosquito-borne flaviviruses, whereas for the tick-borne flaviviruses such design had not been performed. We have constructed homology models of envelope glycoproteins of tick-transmitted flaviviruses with the detergent binding pocket in the open state. Molecular docking of substituted 1,4-dihydropyridines and pyrido[2,1-b][1,3,5]thiadiazines was made against these models, and 89 hits were selected for the in vitro experimental evaluation. Seventeen compounds showed significant inhibition against tick-borne encephalitis virus, Powassan virus, or Omsk hemorrhagic fever virus in the 50% plaque reduction test in PEK cells. These compounds identified through rational design are the first ones possessing reproduction inhibition activity against tick-borne flaviviruses. PMID:24900762

  14. Co-infection and genetic diversity of tick-borne pathogens in roe deer from Poland.

    Science.gov (United States)

    Welc-Falęciak, Renata; Werszko, Joanna; Cydzik, Krystian; Bajer, Anna; Michalik, Jerzy; Behnke, Jerzy M

    2013-05-01

    Wild species are essential hosts for maintaining Ixodes ticks and the tick-borne diseases. The aim of our study was to estimate the prevalence, the rate of co-infection with Babesia, Bartonella, and Anaplasma phagocytophilum, and the molecular diversity of tick-borne pathogens in roe deer in Poland. Almost half of the tested samples provided evidence of infection with at least 1 species. A. phagocytophilum (37.3%) was the most common and Bartonella (13.4%) the rarest infection. A total of 18.3% of all positive samples from roe deer were infected with at least 2 pathogens, and one-third of those were co-infected with A. phagocytophilum, Bartonella, and Babesia species. On the basis of multilocus molecular studies we conclude that: (1) Two different genetic variants of A. phagocytophilum, zoonotic and nonzoonotic, are widely distributed in Polish roe deer population; (2) the roe deer is the host for zoonotic Babesia (Bab. venatorum, Bab. divergens), closely related or identical with strains/species found in humans; (3) our Bab. capreoli and Bab. divergens isolates differed from reported genotypes at 2 conserved base positions, i.e., positions 631 and 663; and (4) this is the first description of Bart. schoenbuchensis infections in roe deer in Poland. We present 1 of the first complex epidemiological studies on the prevalence of Babesia, Bartonella, and A. phagocytophilum in naturally infected populations of roe deer. These game animals clearly have an important role as reservoir hosts of tick-borne pathogens, but the pathogenicity and zoonotic potential of the parasite genotypes hosted by roe deer requires further detailed investigation. PMID:23473225

  15. Incident Tick-Borne Infections in a Cohort of North Carolina Outdoor Workers.

    Science.gov (United States)

    Wallace, John W; Nicholson, William L; Perniciaro, Jamie L; Vaughn, Meagan F; Funkhouser, Sheana; Juliano, Jonathan J; Lee, Sangmi; Kakumanu, Madhavi L; Ponnusamy, Loganathan; Apperson, Charles S; Meshnick, Steven R

    2016-05-01

    Tick-borne diseases cause substantial morbidity throughout the United States, and North Carolina has a high incidence of spotted fever rickettsioses and ehrlichiosis, with sporadic cases of Lyme disease. The occupational risk of tick-borne infections among outdoor workers is high, particularly those working on publicly managed lands. This study identified incident tick-borne infections and examined seroconversion risk factors among a cohort of North Carolina outdoor workers. Workers from the North Carolina State Divisions of Forestry, Parks and Recreation, and Wildlife (n = 159) were followed for 2 years in a randomized controlled trial evaluating the effectiveness of long-lasting permethrin-impregnated clothing. Antibody titers against Rickettsia parkeri, Rickettsia rickettsii, "Rickettsia amblyommii," and Ehrlichia chaffeensis were measured at baseline (n = 130), after 1 year (n = 82), and after 2 years (n = 73). Titers against Borrelia burgdorferi were measured at baseline and after 2 years (n = 90). Baseline seroprevalence, defined as indirect immunofluorescence antibody titers of 1/128 or greater, was R. parkeri (24%), R. rickettsii (19%), "R. amblyommii" (12%), and E. chaffeensis (4%). Incident infection was defined as a fourfold increase in titer over a 1-year period. There were 40 total seroconversions to at least one pathogen, including R. parkeri (n = 19), "R. amblyommii" (n = 14), R. rickettsii (n = 9), and E. chaffeensis (n = 8). There were no subjects whose sera were reactive to B. burgdorferi C6 antigen. Thirty-eight of the 40 incident infections were subclinical. The overall risk of infection by any pathogen during the study period was 0.26, and the risk among the NC Division of Forest Resources workers was 1.73 times that of workers in other divisions (95% confidence interval [CI]: 1.02, 2.92). The risk of infection was lower in subjects wearing permethrin-impregnated clothing, but not significantly (risk ratio

  16. Early detection of tick-borne encephalitis virus spatial distribution and activity in the province of Trento, northern Italy

    Directory of Open Access Journals (Sweden)

    Annapaola Rizzoli

    2007-05-01

    Full Text Available New human cases of tick-borne encephalitis (TBE have recently been recorded outside the recognised foci of this disease, i.e. in the province of Trento in northern Italy. In order to predict the highest risk areas for increased TBE virus activity, we have combined cross-sectional serological data, obtained from 459 domestic goats, with analysis of the autumnal cooling rate based on Moderate Resolution Imaging Spectroradiometer (MODIS land surface temperature (LST data. A significant relationship between finding antibodies against the virus in serum (seroprevalence in goats and the autumnal cooling rate was detected, indicating that the transmission intensity of the virus does not only vary spatially, but also in relation to climatic factors. Virus seroprevalence in goats was correlated with the occurrence of TBE in humans and also with the average number of forestry workers’ tick bites, demonstrating that serological screening of domestic animals, combined with an analysis of the autumnal cooling rate, can be used as early-warning predictors of TBE risk in humans.

  17. Ticks and tick-borne pathogens in wild birds in Greece.

    Science.gov (United States)

    Diakou, Anastasia; Norte, Ana Cláudia; Lopes de Carvalho, Isabel; Núncio, Sofia; Nováková, Markéta; Kautman, Matej; Alivizatos, Haralambos; Kazantzidis, Savas; Sychra, Oldřich; Literák, Ivan

    2016-05-01

    Wild birds are common hosts of ticks and can transport them for long distances, contributing to the spreading of tick-borne pathogens. The information about ticks on birds and tick-borne pathogens in Greece is limited. The present study aimed to evaluate the prevalence and species of ticks infesting wild resident birds (mostly small passerines) in Greece, and to assess Borrelia and Rickettsia infection in the collected ticks. Detection of Borrelia burgdorferi s.l. was performed by nested PCR targeting the flaB gene. Rickettsia spp. were detected by PCR targeting the gltA and ompA genes. Seven (2 %) out of 403 birds examined in northern Greece in 2013 were infested with 15 ticks, identified as Ixodes frontalis, Ixodes acuminatus, Hyalomma marginatum, Hyalomma aegyptium and Hyalomma sp. All ticks were negative for Borrelia spp. while four of them were positive for rickettsiae (Rickettsia aeschlimannii in H. aegyptium and Rickettsia sp. in I. frontalis, H. aegyptium and H. marginatum). Ixodes acuminatus is reported for the first time in Greece and Sylvia borin is reported as a new host record for I. acuminatus. PMID:26847630

  18. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico.

    Science.gov (United States)

    Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe

    2016-09-30

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico. PMID:26726019

  19. Search for tick-borne pathogens in the Svalbard Archipelago and Jan Mayen

    Directory of Open Access Journals (Sweden)

    Jana Elsterová

    2015-10-01

    Full Text Available The tick species Ixodes uriae, parasitizing seabirds in the Arctic, may transmit many pathogens including various arboviruses, Borrelia spirochetes and Babesia apicomplexans. These pathogens may pose an important additional stress to seabirds, which are already stressed by environmental changes such as pollutants and decreased food availability. Here, we present the results of the first screening for arboviruses of the genera Flavivirus, Alphavirus, Orthobunyavirus, Phlebovirus and Orbivirus, as well as Borrelia spirochetes and Babesia apicomplexans from Svalbard and Jan Mayen. Using polymerase chain reaction technology with genus-specific primers, we tested 89 ticks collected on Jan Mayen, Bjørnøya and Spitsbergen between 2008 and 2012. We did not detect any of the screened tick-borne pathogens. Nevertheless, these pathogens may be introduced to Svalbard and Jan Mayen by migratory birds in the near future. The increasing numbers of ticks appearing in the studied areas make this introduction even more likely. Such an introduction would have serious impact on seabird ecology as well as on human public health. Therefore, continuous careful surveillance and monitoring of possible tick-borne pathogen introductions is important.

  20. Tick-borne encephalitis virus in dogs - is this an issue?

    Directory of Open Access Journals (Sweden)

    Dobler Gerhard

    2011-04-01

    Full Text Available Abstract The last review on Tick-borne encephalitis (TBE in dogs was published almost ten years ago. Since then, this zoonotic tick-borne arbovirus has been geographically spreading and emerging in many regions in Eurasia and continues to do so. Dogs become readily infected with TBE virus but they are accidental hosts not capable to further spread the virus. They seroconvert upon infection but they seem to be much more resistant to the clinical disease than humans. Apart from their use as sentinels in endemic areas, however, an increasing number of case reports appeared during the last decade thus mirroring the rising public health concerns. Owing to the increased mobility of people travelling to endemic areas with their companion dogs, this consequently leads to problems in recognizing and diagnosing this severe infection in a yet non-endemic area, simply because the veterinarians are not considering TBE. This situation warrants an update on the epidemiology, clinical presentation and possible preventions of TBE in the dog.

  1. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico.

    Science.gov (United States)

    Sosa-Gutierrez, Carolina G; Vargas-Sandoval, Margarita; Torres, Javier; Gordillo-Pérez, Guadalupe

    2016-09-30

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1107 were collected by tick drag from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico.

  2. Tick-borne rickettsial pathogens in questing ticks, removed from humans and animals in Mexico

    Science.gov (United States)

    Vargas-Sandoval, Margarita; Torres, Javier

    2016-01-01

    Tick-borne rickettsial diseases (TBRD) are commonly encountered in medical and veterinary clinical settings. The control of these diseases is difficult, requiring disruption of a complex transmission chain involving a vertebrate host and ticks. The geographical distribution of the diseases is related to distribution of the vector, which is an indicator of risk for the population. A total of 1,107 ticks were collected by tick dragging from forests, ecotourism parks and hosts at 101 sites in 22 of the 32 states of Mexico. Collected ticks were placed in 1.5 mL cryovials containing 70% ethanol and were identified to species. Ticks were pooled according to location/host of collection, date of collection, sex, and stage of development. A total of 51 ticks were assayed by polymerase chain reaction (PCR) to confirm species identification using morphological methods. A total of 477 pools of ticks were assayed using PCR techniques for selected tick-borne pathogens. Anaplasma phagocytophilum was the most commonly detected pathogen (45 pools), followed by, Ehrlichia (E.) canis (42), Rickettsia (R.) rickettsii (11), E. chaffeensis (8), and R. amblyommii (1). Rhipicephalus sanguineus was the tick most frequently positive for selected pathogens. Overall, our results indicate that potential tick vectors positive for rickettsial pathogens are distributed throughout the area surveyed in Mexico. PMID:26726019

  3. Exposed and concealed antigens as vaccine targets for controlling ticks and tick-borne diseases.

    Science.gov (United States)

    Nuttall, P A; Trimnell, A R; Kazimirova, M; Labuda, M

    2006-04-01

    Tick vaccines derived from Bm86, a midgut membrane-bound protein of the cattle tick, Boophilus microplus, are currently the only commercially available ectoparasite vaccines. Despite its introduction to the market in 1994, and the recognized need for alternatives to chemical pesticides, progress in developing effective antitick vaccines (and ectoparasite vaccines in general) is slow. The primary rate-limiting step is the identification of suitable antigenic targets for vaccine development. Two sources of candidate vaccine antigens have been identified: 'exposed' antigens that are secreted in tick saliva during attachment and feeding on a host and 'concealed' antigens that are normally hidden from the host. Recently, a third group of antigens has been distinguished that combines the properties of both exposed and concealed antigens. This latter group offers the prospect of a broad-spectrum vaccine effective against both adults and immature stages of a wide variety of tick species. It also shows transmission-blocking and protective activity against a tick-borne pathogen. With the proliferation of molecular techniques and their application to vaccine development, there are high hopes for new and effective antitick vaccines that also control tick-borne diseases. PMID:16542317

  4. Isolation and characterization of tick-borne encephalitis virus from Ixodes persulcatus in Mongolia in 2012.

    Science.gov (United States)

    Muto, Memi; Bazartseren, Boldbaatar; Tsevel, Bazartseren; Dashzevge, Erdenechimeg; Yoshii, Kentaro; Kariwa, Hiroaki

    2015-07-01

    Tick-borne encephalitis virus (TBEV) is a zoonotic virus belonging to the genus Flavivirus, in the family Flaviviridae. The virus, which is endemic in Europe and northern parts of Asia, causes severe encephalitis. Tick-borne encephalitis (TBE) has been reported in Mongolia since the 1980s, but details about the biological characteristics of the endemic virus are lacking. In this study, 680 ticks (Ixodes persulcatus) were collected in Selenge aimag, northern Mongolia, in 2012. Nine Mongolian TBEV strains were isolated from tick homogenates. A sequence analysis of the envelope protein gene revealed that all isolates belonged to the Siberian subtype of TBEV. Two strains showed similar growth properties in cultured cells, but their virulence in mice differed. Whole genome sequencing revealed only thirteen amino acid differences between these Mongolian TBEV strains. Our results suggest that these naturally occurring amino acid mutations affected the pathogenicity of Mongolian TBEV. Our results may be an important platform for monitoring TBEV to evaluate the epidemiological risk in TBE endemic areas of Mongolia. PMID:26025267

  5. Translating ecology, physiology, biochemistry and molecular biology research to meet grand challenge of tick and tick-borne diseases in North America

    Science.gov (United States)

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The use of science-based technology to diminish the impact of tick-borne diseases should be an active research effort aimed to protect human and animal populations. Here, ...

  6. Translating ecology, physiology, biochemistry and population genetics research to meet the challenge of tick and tick-borne diseases in North America

    Science.gov (United States)

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal population...

  7. Vaccines for tick-borne diseases and cost-effectiveness of vaccination : a public health challenge to reduce the diseases’ burden

    NARCIS (Netherlands)

    Smit, Renata; Postma, Maarten J

    2016-01-01

    Tick-borne encephalitis (TBE) and Lyme borreliosis (LB) are tick-borne diseases (TBDs), and both present an increasing burden worldwide. Vaccination as public health intervention could be the most effective way to reduce this burden. TBE vaccines are available, but vaccines against LB are still in t

  8. Worldwide distribution and diversity of seabird ticks: implications for the ecology and epidemiology of tick-borne pathogens.

    Science.gov (United States)

    Dietrich, Muriel; Gómez-Díaz, Elena; McCoy, Karen D

    2011-05-01

    The ubiquity of ticks and their importance in the transmission of pathogens involved in human and livestock diseases are reflected by the growing number of studies focusing on tick ecology and the epidemiology of tick-borne pathogens. Likewise, the involvement of wild birds in dispersing pathogens and their role as reservoir hosts are now well established. However, studies on tick-bird systems have mainly focused on land birds, and the role of seabirds in the ecology and epidemiology of tick-borne pathogens is rarely considered. Seabirds typically have large population sizes, wide geographic distributions, and high mobility, which make them significant potential players in the maintenance and dispersal of disease agents at large spatial scales. They are parasitized by at least 29 tick species found across all biogeographical regions of the world. We know that these seabird-tick systems can harbor a large diversity of pathogens, although detailed studies of this diversity remain scarce. In this article, we review current knowledge on the diversity and global distribution of ticks and tick-borne pathogens associated with seabirds. We discuss the relationship between seabirds, ticks, and their pathogens and examine the interesting characteristics of these relationships from ecological and epidemiological points of view. We also highlight some future research directions required to better understand the evolution of these systems and to assess the potential role of seabirds in the epidemiology of tick-borne pathogens. PMID:20874222

  9. A Controlled Trial of a Novel Primary Prevention Program for Lyme Disease and Other Tick-Borne Illnesses

    Science.gov (United States)

    Daltroy, Lawren H.; Phillips, Charlotte; Lew, Robert; Wright, Elizabeth; Shadick, Nancy A.; Liang, Matthew H.

    2007-01-01

    To evaluate a theory-based educational program to prevent Lyme disease and other tick-borne illnesses (TBI), a randomized controlled trial of an educational program was delivered to ferry passengers traveling to an endemic area in southeastern Massachusetts. Rates of TBI and precautionary and tick check behaviors were measured over three summers…

  10. Molecular Detection of Tick-Borne Pathogens in Humans with Tick Bites and Erythema Migrans, in the Netherlands

    Science.gov (United States)

    Jahfari, Setareh; Hofhuis, Agnetha; Fonville, Manoj; van der Giessen, Joke; van Pelt, Wilfrid; Sprong, Hein

    2016-01-01

    Background Tick-borne diseases are the most prevalent vector-borne diseases in Europe. Knowledge on the incidence and clinical presentation of other tick-borne diseases than Lyme borreliosis and tick-borne encephalitis is minimal, despite the high human exposure to these pathogens through tick bites. Using molecular detection techniques, the frequency of tick-borne infections after exposure through tick bites was estimated. Methods Ticks, blood samples and questionnaires on health status were collected from patients that visited their general practitioner with a tick bite or erythema migrans in 2007 and 2008. The presence of several tick-borne pathogens in 314 ticks and 626 blood samples of this cohort were analyzed using PCR-based methods. Using multivariate logistic regression, associations were explored between pathogens detected in blood and self-reported symptoms at enrolment and during a three-month follow-up period. Results Half of the ticks removed from humans tested positive for Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Candidatus Neoehrlichia mikurensis, Rickettsia helvetica, Rickettsia monacensis, Borrelia miyamotoi and several Babesia species. Among 92 Borrelia burgdorferi s. l. positive ticks, 33% carried another pathogen from a different genus. In blood of sixteen out of 626 persons with tick bites or erythema migrans, DNA was detected from Candidatus Neoehrlichia mikurensis (n = 7), Anaplasma phagocytophilum (n = 5), Babesia divergens (n = 3), Borrelia miyamotoi (n = 1) and Borrelia burgdorferi s. l. (n = 1). None of these sixteen individuals reported any overt symptoms that would indicate a corresponding illness during the three-month follow-up period. No associations were found between the presence of pathogen DNA in blood and; self-reported symptoms, with pathogen DNA in the corresponding ticks (n = 8), reported tick attachment duration, tick engorgement, or antibiotic treatment at enrolment. Conclusions Based on molecular

  11. The First case of Locally Acquired Tick-Borne Babesia Microti Infection in Canada

    Directory of Open Access Journals (Sweden)

    Jared MP Bullard

    2014-01-01

    Full Text Available A child with a complicated medical history that included asplenia acquired an infection with Babesia microti in the summer of 2013 and had not travelled outside of Manitoba. Although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of Babesia species, while reference laboratory testing confirmed the diagnosis. Blacklegged ticks (Ixodes scapularis are known to transmit Borrelia burgdorferi and Anaplasma phagocytophilum in the province; however, the present case represents the first known instance of tick-borne B microti, both in Manitoba and in Canada. The expanding territory of the blacklegged tick increases the relevance of this emerging infection. Clinicians, laboratory medical practitioners and public health officials should be aware of B microti as a potential locally acquired infection in Canada.

  12. Role of neuroadiological methods for differential diagnosis of tick-borne meningioradiculitis

    Energy Technology Data Exchange (ETDEWEB)

    Dickschas, A.; Grabisch, R.

    1986-12-01

    A 72-year old female patient with severe sensory-motor deficits of proximal regions of the lower extremities was initially considered to suffer from an L 3/4 syndrome. Results of computer tomography and myelography showed a corresponding compression apparently due to a spondyloarthritic spinal stenosis. However, spinal fluid analysis and additional aspects of the patient's history led to a diagnosis of tick-borne meningial radiculitis caused by the spirochete Borrelia burgdorferi. The close correlation between clinical, radiological and laboratory findings made an early specific therapy possible which produced an unusually rapid and complete recovery from the severe neurological deficits. The initial close agreement between the clinical and radiological findings prompt some additional critical considerations.

  13. Review of tick-borne encephalitis and vaccines: clinical and economical aspects.

    Science.gov (United States)

    Šmit, Renata; Postma, Maarten J

    2015-05-01

    Tick-borne encephalitis (TBE) disease is an increasing burden not only locally but also globally. In most endemic countries, vaccination coverage is too low to reduce the TBE burden significantly; however, vaccination is the most effective protection against TBE, with various vaccines currently available. In spite of rising awareness of TBE, little attention is directed toward the health economics of the disease. The purpose of the present review is to compile information on TBE and its explicit clinical and economical aspects. Given the scarcity of studies, the authors conclude that more attention is needed for health economics of TBE. Notably, this would help establish guidance on efficient policies for TBE prevention, reduce disease burden and achieve population health benefits. PMID:25427237

  14. Small risk of developing symptomatic tick-borne diseases following a tick bite in the Netherlands

    Directory of Open Access Journals (Sweden)

    Hofhuis Agnetha

    2011-02-01

    Full Text Available Abstract Background In The Netherlands, the incidence of Lyme borreliosis is on the rise. Besides its causative agent, Borrelia burgdorferi s.l., other potential pathogens like Rickettsia, Babesia and Ehrlichia species are present in Ixodes ricinus ticks. The risk of disease associated with these microorganisms after tick-bites remains, however, largely unclear. A prospective study was performed to investigate how many persons with tick-bites develop localized or systemic symptoms and whether these are associated with tick-borne microorganisms. Results In total, 297 Ixodes ricinus ticks were collected from 246 study participants who consulted a general practitioner on the island of Ameland for tick bites. Ticks were subjected to PCR to detect DNA of Borrelia burgdorferi s.l., Rickettsia spp., Babesia spp. or Ehrlichia/Anaplasma spp.. Sixteen percent of the collected ticks were positive for Borrelia burgdorferi s.l., 19% for Rickettsia spp., 12% for Ehrlichia/Anaplasma spp. and 10% for Babesia spp.. At least six months after the tick bite, study participants were interviewed on symptoms by means of a standard questionnaire. 14 out of 193 participants (8.3% reported reddening at the bite site and 6 participants (4.1% reported systemic symptoms. No association between symptoms and tick-borne microorganisms was found. Attachment duration ≥24 h was positively associated with reddening at the bite site and systemic symptoms. Using logistic regression techniques, reddening was positively correlated with presence of Borrelia afzelii, and having 'any symptoms' was positively associated with attachment duration. Conclusion The risk of contracting acute Lyme borreliosis, rickettsiosis, babesiosis or ehrlichiosis from a single tick bite was

  15. Heterogeneous Associations of Ecological Attributes with Tick-Borne Rickettsial Pathogens in a Periurban Landscape.

    Science.gov (United States)

    Raghavan, Ram K; Goodin, Douglas G; Dryden, Michael W; Hroobi, Ali; Gordon, David M; Cheng, Chuanmin; Nair, Arathy D; Jakkula, Laxmi U M R; Hanzlicek, Gregg A; Anderson, Gary A; Ganta, Roman R

    2016-09-01

    The variations in prevalence levels of two tick-borne rickettsial pathogens, Ehrlichia chaffeensis and Ehrlichia Ewingii, in a periurban environment were evaluated along with their ecological determinants. Tick life stage and sex, month of tick collection, landscape fragmentation, and ecological covariates specific to pasture and woodland sites were considered as explanatory covariates. Questing lone star ticks (Amblyomma americanum) were collected by flagging for an hour once every week during mid-April through mid-August in years 2013 and 2014. A total of 4357 adult and nymphal ticks (woodland = 2720 and pasture = 1637) were collected and assessed for pathogen prevalence by molecular methods. Female A. americanum ticks were more infected with E. chaffeensis than males or nymphs in woodland areas [♂ = 6.05%; ♀ = 12.0%; nymphs = 2.09%] and pastures [♂ = 8.05%; ♀ = 12.03%; nymphs = 3.33%], and the prevalence was influenced by edge density in the landscape. Higher E. ewingii infection was noted among female A. americanum ticks within woodland areas [♂ = 1.89%; ♀ = 2.14%; nymphs = 1.57%], but no such difference was evident in pastures [♂ = 1.03%; ♀ = 1.33%; nymphs = 1.12%]. Prevalence of E. ewingii was influenced by edge contrast index, and the percentage of pasture perimeter that was less than 20 meters from woodland areas. This study elucidates the complexity of tick-borne pathogen ecology and points to the need for further studies on the role of reservoir hosts, particularly that played by small vertebrates, which is not fully understood in the region.

  16. Research on the ecology of ticks and tick-borne pathogens - methodological principles and caveats

    Directory of Open Access Journals (Sweden)

    Agustín eEstrada-Peña

    2013-08-01

    Full Text Available Interest in tick-transmitted pathogens has experienced an upsurge in the past few decades. Routine application of tools for the detection of fragments of foreign DNA in ticks, together with a high degree of interest in the quantification of disease risk for humans, has led to a marked increase in the number of reports on the eco-epidemiology of tick-borne diseases. However, procedural errors continue to accumulate in the scientific literature, resulting in misleading information. For example, unreliable identification of ticks and pathogens, erroneous interpretations of short-term field studies, and the hasty acceptance of some tick species as vectors have led to ambiguities regarding the vector role of these arthropods. In this review, we focus on the ecological features driving the life cycle of ticks and the resulting effects on the eco-epidemiology of tick-transmitted pathogens. We review the factors affecting field collections of ticks, and we describe the biologically and ecologically appropriate procedures for describing tick host-seeking activity and its correlation with environmental traits. We detail the climatic variables that have biological importance on ticks and explain how they should be properly measured and analyzed. We also provide evidence to critically reject the use of some environmental traits that are being increasingly reported as the drivers of the behavior of ticks. With the aim of standardization, we propose unambiguous definitions of the status of hosts and ticks regarding their ability to maintain and spread a given pathogen. We also describe laboratory procedures and standards for evaluating the vectorial status of a tick or the reservoir role of a host. Such harmonization in protocols and terms should provide a coherent framework for the reporting of research findings concerning ticks and tick-borne diseases.

  17. Current updates on diagnostic methodologies for tick-borne hemoparasitic diseases in equids: A review

    Directory of Open Access Journals (Sweden)

    Lawan Adamu

    2016-06-01

    Full Text Available Tick-borne diseases (TBDs or otherwise called equine piroplasmosis (EP are the foremost economic limitations to equids production. Thus, reducing the breeding capability and athletic performance of equids globally. Identification of these haemoparasites is crucial in understanding their distribution in the population and it is imperative to discern between species and subspecies that are responsible for the occurrence of the disease conditions. Conventional procedures such as microscopic and serological evaluations do not usually meet these prerequisites. Diagnostic contrivances, such as the complement fixation test (CFT, the indirect fluorescent antibody test (IFAT and the enzyme linked immunosorbent assay (ELISA have been efficaciously used for many years. Furthermore, DNA-based investigations for identification, differentiation and classification of different haemoparasites have also been established. Molecular diagnostic procedures, such as DNA hybridization, polymerase chain reaction (PCR, transcriptomics, proteomics, metagenomics and metabolomics, permit the uncovering of parasites in blood, tissues or ticks with optimal sensitivity, specificity and consistency. In addition, these procedures can be exploited to detect definite species and subspecies. The prerequisite of these investigations must include proper premeditation and validation, these investigations provide an effective device for molecular studies, with greater benefits of flexibility to standardization. The application of these procedures for studying TBDs or EP globally will be irreplaceable for a long period from now. Therefore, the aim of this review is to draw up the specifics of the procedures in more convenient form for practitioners and researchers. KEY WORDS: Diagnosis, equids, molecular, transcriptomics, proteomics, metagenomics, metabolomics, haemoparasites, tick-borne diseases [J Adv Vet Anim Res 2016; 3(2.000: 84-91

  18. Tick-borne encephalitis as a notifiable disease--Status quo and the way forward. Report of the 17th annual meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE).

    Science.gov (United States)

    Kunze, Ursula

    2015-07-01

    The 17th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE), a group of neurologists, general practicioners, clinicians, travel physicians, virologists, pediatricians, and epidemiologists, was held under the title "Tick-borne encephalitis as a notifiable disease--status quo and the way forward". The conference agenda was divided into three parts on the first day: "Epidemiology & Risk areas", "Poster Walk: Epidemiological Update in Europe", and "News in TBE Research". On the second day, a World Café Working Session took place where the participants could choose three tables out of six to join for discussion. Key topics on current epidemiological developments and investigations, risk areas, cases, travel and mobility, TBE in children, vaccination rates, and latest news on vaccination were presented and extensively discussed. PMID:26025269

  19. Tick-borne encephalitis-still on the map: Report of the 18th annual meeting of the international scientific working group on tick-borne encephalitis (ISW-TBE).

    Science.gov (United States)

    Kunze, Ursula

    2016-07-01

    The 18th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE)-a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians and epidemiologists-was held under the title 'Tick-borne encephalitis-still on the map'. The conference agenda was divided into six sessions: 'National Implementation of EU notifiable disease status', 'Virology', 'Epidemiology and Risk areas & Poster Walk Epidemiological Update', 'Clinic', 'Environmental Factors' and 'New Findings and Diagnosis'. Key topics such as 'TBE as a notifiable disease-results of the third European survey', 'TBE vaccines over the years', 'Overview of flaviviruses', 'TBE virus phylogenetics', 'Current epidemiological developments and investigations', 'Clinical aspects', 'TBE in veterinary medicine', 'Laboratory diagnostic', 'Occupational risk', 'Allergy, obesity, and vaccination' were presented and extensively discussed.

  20. Tick-borne encephalitis--a notifiable disease: report of the 15th Annual Meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE).

    Science.gov (United States)

    Kunze, Ursula

    2013-09-01

    The 15th Meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE)--a group of neurologists, general practicioners, clinicians, travel physicans, virologists, pediatricians, and epidemiologists--was held under the title "Tick-Borne Encephalitis--a notifiable disease". With the inclusion of TBE in the list of notifiable diseases, an important measure was established to continue improving the level of evidence on TBE in Europe to better help guide policies and methods to lower the burden of this disease. Due to differences in diagnosis, case definition, and reporting in European countries, the overall epidemiology and burden of TBE remains unclear. During the meeting, important issues regarding epidemiology, risk areas, vaccination rates, and latest news on vaccination were presented and extensively discussed. A poster session provided an overview of the epidemiological situation 2012 in 13 European countries. PMID:23831368

  1. Tick-borne encephalitis-still on the map: Report of the 18th annual meeting of the international scientific working group on tick-borne encephalitis (ISW-TBE).

    Science.gov (United States)

    Kunze, Ursula

    2016-07-01

    The 18th meeting of the International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE)-a group of neurologists, general practitioners, clinicians, travel physicians, virologists, pediatricians and epidemiologists-was held under the title 'Tick-borne encephalitis-still on the map'. The conference agenda was divided into six sessions: 'National Implementation of EU notifiable disease status', 'Virology', 'Epidemiology and Risk areas & Poster Walk Epidemiological Update', 'Clinic', 'Environmental Factors' and 'New Findings and Diagnosis'. Key topics such as 'TBE as a notifiable disease-results of the third European survey', 'TBE vaccines over the years', 'Overview of flaviviruses', 'TBE virus phylogenetics', 'Current epidemiological developments and investigations', 'Clinical aspects', 'TBE in veterinary medicine', 'Laboratory diagnostic', 'Occupational risk', 'Allergy, obesity, and vaccination' were presented and extensively discussed. PMID:27189584

  2. Infection Prevalences of Common Tick-borne Pathogens in Adult Lone Star Ticks (Amblyomma americanum) and American Dog Ticks (Dermacentor variabilis) in Kentucky

    OpenAIRE

    Fritzen, Charissa M.; Huang, Junjun; Westby, Kathleen; Freye, James D.; Dunlap, Brett; Yabsley, Michael J.; Schardein, Mike; Dunn, John R.; Jones, Timothy F.; Moncayo, Abelardo C.

    2011-01-01

    Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007–2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Ri...

  3. Seroprevalence report on tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever virus among Malaysian’s farm workers

    OpenAIRE

    Mohd Shukri, Munirah; Ling Kho, Kai; Ghane Kisomi, Masoumeh; Lani, Rafidah; Marlina, Suria; Muhd Radzi, Siti Fatimah; Tee Tay, Sun; Ping Wong, Li; Awang Mahmud, Awang Bulgiba; Hassan Nizam, Quaza Nizamuddin; Abu Bakar, Sazaly; Zandi, Keivan

    2015-01-01

    Background Tick-borne encephalitis virus (TBEV) and Crimean-Congo haemorrhagic fever virus (CCHFV) are important tick-borne viruses. Despite their wide geographical distribution and ease of acquisition, the prevalence of both viruses in Malaysia is still unknown. This study was conducted to determine the seroprevalence for TBEV and CCHFV among Malaysian farm workers as a high-risk group within the population. Methods We gave questionnaires to 209 farm workers and invited them to participate i...

  4. Increased levels of sphingosine-1-phosphate in cerebrospinal fluid of patients diagnosed with tick-borne encephalitis

    OpenAIRE

    Kułakowska, Alina; Byfield, Fitzroy J; Żendzian-Piotrowska, Małgorzata; Zajkowska, Joanna M; Drozdowski, Wiesław; Mroczko, Barbara; Janmey, Paul A.; Bucki, Robert

    2014-01-01

    Background Tick-borne encephalitis (TBE) is a serious acute central nervous system infection that can result in death or long-term neurological dysfunctions. We hypothesize that changes in sphingosine-1-phosphate (S1P) concentration occur during TBE development. Methods S1P and interleukin-6 (IL-6) concentrations in blood plasma and cerebrospinal fluid (CSF) were measured using HPLC and ELISA, respectively. The effects of S1P on cytoskeletal structure and IL-6 production were assessed using r...

  5. The International Scientific Working Group on Tick-Borne Encephalitis (ISW TBE): Review of 17 years of activity and commitment.

    Science.gov (United States)

    Kunze, Ursula

    2016-04-01

    Tick-borne encephalitis (TBE) has been a growing public health problem in Europe and other parts of the world for the past 20 years. In 1999, in order to encourage the control of TBE, international experts created a new body: The International Scientific Working Group on Tick-Borne Encephalitis (ISW-TBE). This Working Group has been composed of internationally recognized scientific experts from tick-borne encephalitis virus (TBEv)-endemic and non-endemic regions with extensive personal expertise in the field and a high level of commitment to improve the knowledge of TBE and to increase the public awareness of TBE. Since the foundation of the Working Group, ISW-TBE members meet annually. Every meeting is dedicated to a specific topic, and since 2004 a yearly conference report has been published to inform the scientific community about the latest developments. Among the specific issues that have been extensively discussed over the years were the following: clinical aspects of the disease, TBE in children and golden agers, epidemiology, possible causes for the increase in TBE incidence in Europe, TBE and awareness, TBE and travel, (low) vaccination rates, and the cooperation with the European Centre for Disease Prevention and Control (ECDC). This paper gives an overview of the most important activities and achievements of the ISW-TBE over the past 17 years. PMID:26795231

  6. Evidence of co-infection with Mycobacterium bovis and tick-borne pathogens in a naturally infected sheep flock.

    Science.gov (United States)

    López, Vladimir; Alberdi, Pilar; Fernández de Mera, Isabel G; Barasona, José Angel; Vicente, Joaquín; Garrido, Joseba M; Torina, Alessandra; Caracappa, Santo; Lelli, Rossella Colomba; Gortázar, Christian; de la Fuente, José

    2016-03-01

    Ticks are responsible for the transmission of pathogens of veterinary importance, including those affecting sheep. The current study was designed to investigate co-infections with tick-borne and other pathogens in a naturally infected sheep flock with poor health condition using serology and PCR. Infection with Anaplasma ovis was detected by serology and PCR in 56% of the animals. The presence of Rickettsia spp. of the Spotted Fever Group (SFG) was detected by PCR and sequence analysis in 31% of the animals. All the animals were negative for Anaplasma phagocytophilum either by serology or PCR. Twelve sheep were randomly selected for anatomopathological studies. Five of these animals presented lesions consistent with Mycobacterium tuberculosis complex (MTBC) infection and spoligotyping confirmed infection with Mycobacterium bovis spoligotype SB0339. Co-infection with tick-borne pathogens and MTBC could contribute to the poor health condition observed in these animals but other uncontrolled factors may also be responsible. The differential expression of immune response genes supported previous findings in ruminants and suggested that infection with tick-borne pathogens and M. bovis may results in unique gene expression patterns in sheep. The results underline the need for further research into the possible role of sheep in the epidemiology of animal tuberculosis.

  7. Sero-epidemiological survey on bovine tick-borne diseases in the Lesser Antilles

    International Nuclear Information System (INIS)

    As part of a tick-borne disease control programme in the Lesser Antilles, studies were undertaken to determine the prevalence of cowdriosis, babesiosis and anaplasmosis in an effort to determine what the impact of tick eradication would be. The epidemiological situation for bovine babesiosis and anaplasmosis is unstable in all the islands of the Lesser Antilles, but the clinical cases are only recorded in imported breeds, which represent less than 5% of the cattle population. The native cattle population react as if naturally resistant. When the A. variegatum tick eradication campaign begins, it will be necessary, by the end of the acaricide treatment regime, to immunize all the imported cattle born during that period, and possibly all of the seronegative imported cattle already on the islands. Both Antigua and Guadeloupe have a long history of infestation with the tick and both have experienced clinical cases of cowdriosis. On the other islands, less than 6% of the sera were positive and this correlates well also with an apparent absence of clinical cases of cowdriosis. (author)

  8. Rodents as carriers of tick-borne zoonotic diseases and their ecological impact

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    Paulauskas, A.

    2011-10-01

    Full Text Available Rodents as pests are known to be reservoirs of tick-borne zoonotic infection of viral, bacterial and protozoan origin and are important hosts of the immature stages of Ixodes ticks. A total 493 rodents were live-trapped in different habitat in two biogeographical regions Lithuania and Norway. The ecological impact of different species of rodents in particular habitats was evaluated according to their infestation with ticks and presence of Borrelia burgdorferi s.l. and Anaplasma phagocytophilum infection. Results of the present study demonstrate that although the infestation rate varied between rodent species it was dependent on sampling location and not correlated with infection prevalence in rodents. We observed that mice in Lithuania were more frequently infested with ticks than voles, but, the higher prevalence of B. burgdorferi s.l. infection was detected in voles, than in mice. The overall prevalence of infection in Lithuania was higher than in Norway. In Norway, prevalence of infection in A. flavicollis and M. glareolus was not significantly different. The present study confirmed evidence that the rodent impact on maintenance of Lyme borreliosis depends on biogeographical region and habitat type, and that the zoonotic reservoirs of B. afzelii are M. arvalis, M. glareolus, and A. flavicollis in Lithuania, and A. flavicollis, A. sylvaticus and M. glareolus in Norway. In our present study A. phagocytophilum was not detected in any of the rodents.

  9. Emergence of tick-borne encephalitis in new endemic areas in Austria: 42 years of surveillance.

    Science.gov (United States)

    Heinz, F X; Stiasny, K; Holzmann, H; Kundi, M; Sixl, W; Wenk, M; Kainz, W; Essl, A; Kunz, C

    2015-04-02

    Human infections with tick-borne encephalitis (TBE)virus are a public health concern in certain regions of Europe, central and eastern Asia. Expansions of endemic areas and increased incidences have been associated with different factors including ecological changes supporting tick reproduction, socioeconomic changes increasing human outdoor activities and climatic changes favouring virus circulation in natural foci. Austria is among the most strongly affected countries in Central Europe, but the annual number of cases has strongly declined due to vaccination. Here,we have analysed changes of the incidence of TBE in the unvaccinated population of all federal states of Austria over a period of 42 years. The overall incidence in Austria has remained constant, but new strongly affected endemic regions have emerged in alpine valleys in the west of Austria. In parallel, the incidence in low-land regions in the north-east of the country is decreasing. There is no evidence for a shift to higher altitudes of infection sites in the traditional TBE zones,but the average altitudes of some newly established endemic areas in the west are significantly higher. Our analyses underscore the focal nature of TBE endemic areas and the potential of TBE virus to emerge in previously unaffected regions.

  10. Detection and Characterization of Tick-Borne Encephalitis Virus in Baltic Countries and Eastern Poland

    Science.gov (United States)

    Katargina, Olga; Russakova, Stanislava; Geller, Julia; Kondrusik, Macije; Zajkowska, Joanna; Zygutiene, Milda; Bormane, Antra; Trofimova, Julia; Golovljova, Irina

    2013-01-01

    Ticks were collected from the vegetation in the Baltic countries Estonia, Latvia, Lithuania and eastern Poland and analyzed for the presence of tick-borne encephalitis virus (TBEV) by amplification of the partial E and NS3 genes. In Estonia we found statistically significant differences in the TBEV prevalence between I. persulcatus and I. ricinus ticks (4.23% and 0.42%, respectively). In Latvia, the difference in TBEV prevalence between the two species was not statistically significant (1.02% for I. persulcatus and 1.51% for I. ricinus, respectively). In Lithuania and Poland TBEV was detected in 0.24% and 0.11% of I. ricinus ticks, respectively. Genetic characterization of the partial E and NS3 sequences demonstrated that the TBEV strains belonged to the European subtype in all countries, as well as to the Siberian subtype in Estonia. We also found that in areas where ranges of two tick species overlap, the TBEV subtypes may be detected not only in their natural vector, but also in sympatric tick species. PMID:23650497

  11. REACTOGENITY OF TICK-BORNE ENCEPHALITIS VACCINE ENCEPUR ADULT AND IMMUNE RESPONSE

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    G. N. Leonova

    2005-01-01

    Full Text Available Abstract. The comprehensive clinical-immunological characteristic of a tick-borne encephalitis vaccine En-cepur Adult (Germany, which was studied on a group of residents of Far East of Russia was discussed. Reactogenity in 32,4% of vaccinees was characterized by minor clinical manifestations and was due to the reaction to specific vaccine albumin. Expression of immune response (mean geometric titers was evaluated in a neutralization test. A group with the reactogenity showed higher geometric mean antibody titers (1:182 compared with a group without the reactogenity (1:97.All of vaccinees with various levels (high, middle, low of specific immune response had an increased quantity of CD20+ and CD25+ lymphocytes. We showed a difference in immunologic reactivity of people with high and low levels of specific antibody response. As compared with a low level group the group with a high level of specific response showed significantly higher quantity of lymphocytes and their subpopulations (CD3+, CD4+, CD45RA+ as well as higher levels of IgM, IgG.We conclude that vaccine Encepur Adult (Germany possesses a high immunologic activity. It is recommended to use this vaccine as a safe and effective specific preventive remedy in TBE endemic areas.

  12. Prevalence of tick-borne encephalitis virus antibodies in dogs from Denmark

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    Houser Geoffrey A

    2009-12-01

    Full Text Available Abstract Background Large regions of central and eastern Europe are recognized as areas where tick-borne encephalitis virus (TBEV is endemic, including countries neighbouring Denmark. It is therefore timely and relevant to determine if TBEV infections occur in Denmark. This study investigates the presence of antibodies against TBEV in a cross-section of the Danish canine population to assess the level of exposure to TBEV and possibly identify TBEV microfoci in Denmark. Methods Blood samples were collected from 125 dogs originating from five regions of Denmark between November 2005 and March 2006. Serum was tested by indirect ELISA. All positive and borderline samples were re-evaluated by neutralisation test (NT. Results The prevalence of TBEV serocomplex antibodies was 30% by ELISA and 4.8% by NT (with 100%-neutralising capacity. The island of Bornholm was the only area in Denmark with NT positive samples. Conclusions The island of Bornholm is an area with a high risk of encountering TBEV microfoci. The presence of TBEV serocomplex antibodies in many sentinel animals from other parts of Denmark points toward existence of other TBEV microfoci. Discrepancies found between ELISA and NT results stress the importance of careful evaluation of serological tests, when interpreting results.

  13. Tick and tick borne protozoan diseases of livestock in the selected hilly areas of Bangladesh

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    U.K. Mohanta

    2011-12-01

    Full Text Available To study the tick and tick borne protozoan diseases of livestock in the hilly areas of Bangladesh, an attempt was made to collect tick and blood samples from cattle, goat and gayal (Bos frontalis from different areas of the three hill districts. In this study, two species of ticks namely, Boophilus microplus (92% and Amblyomma testudinarium (21.6% and two species of blood protozoa like Babesia bigemina (16.63% and Anaplasma marginale (14.94% were recorded. Seasonal prevalence of ticks was highest in summer (97% in comparison to rainy (95% and winter (86% season. On the other hand, the seasonal prevalence of blood protozoa was highest in rainy season (45.45% in comparison to summer (27.87% and winter (16.55%. Again, animals aged more than 2 (two years of age (52% found to be more susceptible to blood protozoan diseases than animals aged between 1-2 years of age (33.97%. But none of the animals under one year of age were found to be infected with blood protozoan diseases.

  14. THE AUSTRIAN VACCINATION PARADOX: TICK-BORNE ENCEPHALITIS VACCINATION VERSUS INFLUENZA VACCINATION.

    Science.gov (United States)

    Kunze, Ursula; Kunze, Michael

    2015-09-01

    This paper describes a paradoxical situation in Austria. The vaccination rate against tick-borne encephalitis (TBE) in the general population is 82%, which is the highest worldwide, whereas the vaccination rate against influenza is about 8% and is among the lowest worldwide. A high awareness of TBE among the Austrian population achieved by an annual social marketing programme and the wide use of effective and well-tolerated vaccines have led to a successful containment of that disease. The vaccination coverage increased from 6% in 1980 to 82% in 2013 and exceeds 90% in some high-risk areas. This has led to a steady decline in the number of TBE cases from several hundred cases to 50 to 100 cases per year. The situation in regard to influenza vaccination is the opposite. Although Austria has issued one of the most extensive recommendations for influenza vaccination worldwide, the vaccination rate of the general population is extremely low. The possible reasons for the failure in the implementation of recommendations are ignorance, lack of social marketing and the predominance of a distinct discordance within the health system in general, and the Austrian medical fraternity in particular. PMID:26615654

  15. Epidemiology of tick-borne encephalitis (TBE) in Europe and its prevention by available vaccines.

    Science.gov (United States)

    Amicizia, Daniela; Domnich, Alexander; Panatto, Donatella; Lai, Piero Luigi; Cristina, Maria Luisa; Avio, Ulderico; Gasparini, Roberto

    2013-05-01

    Tick-borne Encephalitis (TBE), which is caused by a Flavivirus, is the most common tick-transmitted disease in Central and Eastern Europe and Russia. Today, TBE is endemic in 27 European countries, and has become an international public health problem. The epidemiology of TBE is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. Vaccination remains the most effective protective measure against TBE for people living in risk zones, occupationally exposed subjects and travelers to endemic areas. The vaccines currently in use are FSME-Immun(®), Encepur(®), EnceVir(®) and TBE vaccine Moscow(®). The numerous studies performed on the efficacy and safety of these vaccines have shown a high level of immunogenicity and an excellent safety profile. Several studies have also shown a high level of cross-protection among strains belonging to different subtypes.   In the present paper we attempted to describe the continuously changing epidemiology of TBE in European States and to overview clinical development of available vaccines paying particular attention on cross-protection elicited by the vaccines.

  16. Molecular Detection of Tick-Borne Rickettsiales in Goats and Sheep from Southeastern China.

    Science.gov (United States)

    Ge, Yan; Yin, Hongmei; Rikihisa, Yasuko; Pan, Weiqing; Yin, Hong

    2016-05-01

    Members from Rickettsiales such as Anaplasma phagocytophilum, Ehrlichia chaffeensis, and some spotted fever group (SFG) Rickettsiae are important tick-borne pathogens. One hundred goats and sheep from southeastern China were examined for the presence of Anaplasma, E. chaffeensis, and SFG Rickettsiae by PCR. A. phagocytophilum, Anaplasma bovis, and Anaplasma centrale were detected in 15, 49, and 16 samples, respectively. The A. phagocytophilum and A. centrale were highly homologous to strains from Japanese sika deer and Japanese cattle, respectively, whereas a diversity of A. bovis sequences were detected. New genetic variants of Anaplasma close to A. centrale have been revealed. No Ehrlichia was detected in this study. The presence of SFG Rickettsiae was determined in 26 samples. The coinfection with more than two pathogens tested in this study was as high as 29%. This study has molecularly characterized the circulation of Anaplasma and Rickettsiae in goats and sheep in southeastern China, which highlights the risk of contracting the pathogens upon tick exposure. PMID:26872274

  17. Study of the climatic change impact on vector-borne diseases in West Africa: the case of tick-borne borreliosis and malaria; Etude de l'impact du changement climatique sur les maladies a transmission vectorielle en Afrique de l'Ouest: le cas de la borreliose a tiques et du paludisme

    Energy Technology Data Exchange (ETDEWEB)

    Trape, J.F

    2005-04-15

    Malaria and tick-borne borreliosis are the two first causes of morbidity due to vector-borne diseases in a large part of Sudan-sahelian West Africa. They are also the two tropical diseases which have been the most affected by climatic change in recent years. In the case of tick-borne borreliosis it has been shown in Senegal that the persistence of drought since the years 70 has been associated with a considerable extension of the geographic range of diseases and the vector tick A-sonrai, a species that was in the past limited to the Sahara and Sahel. In the case of malaria, drought has strongly reduced in these same regions of Africa the distribution, abundance and infection rate of Anopheline mosquitoes, but without any significant reduction of the burden of malaria for most populations concerned. The emergence and spread of Plasmodium falciparum resistance to antimalarial drugs only explain part of this phenomenon. (A.L.B.)

  18. Phylogeographic characterization of tick-borne encephalitis virus from patients, rodents and ticks in Slovenia.

    Directory of Open Access Journals (Sweden)

    Luka Fajs

    Full Text Available Tick-borne encephalitis virus (TBEV is the most important arboviral agent causing infections of the central nervous system in central Europe. Previous studies have shown that TBEV exhibits pronounced genetic variability, which is often correlated to the geographical origin of TBEV. Genetic variability of TBEV has previously been studied predominantly in rodents and ticks, while information about the variability in patients is scarce. In order to understand the molecular relationships of TBEV between natural hosts, vectors and humans, as well as correlation between phylogenetic and geographical clustering, sequences of TBEV E and NS5 protein genes, were obtained by direct sequencing of RT-PCR products from TBE-confirmed patients as well as from rodents and ticks collected from TBE-endemic regions in Slovenia. A total of 27 partial E protein gene sequences representing 15 human, 4 rodent and 8 tick samples and 30 partial NS5 protein gene sequences representing 17 human, 5 rodent and 8 tick samples were obtained. The complete genome sequence of TBEV strain Ljubljana I was simultaneously obtained. Phylogenetic analysis of the E and NS5 protein gene sequences revealed a high degree of TBEV variability in patients, ticks and rodents. Furthermore, an evident correlation between geographical and phylogenetic clustering was shown that was independent of the TBEV host. Moreover, we show the presence of a possible recombination event in the TBEV genome obtained from a patient sample, which was supported with multiple recombination event detection methods. This is the first study that simultaneously analyzed the genetic relationships of directly sequenced TBEV samples from patients, ticks and rodents and provides the largest set of patient-derived TBEV sequences up to date. In addition, we have confirmed the geographical clustering of TBEV sequences in Slovenia and have provided evidence of a possible recombination event in the TBEV genome, obtained from a

  19. Laboratory diagnosis of tick-borne African relapsing fevers: latest developments

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    Aurélien eFotso Fotso

    2015-11-01

    Full Text Available In Africa, relapsing fevers caused by ectoparasite-borne Borrelia species are transmitted by ticks, with the exception of Borrelia recurrentis, which is a louse-borne spirochete. These tropical diseases responsible for mild to deadly spirochetemia. Cultured B. crocidurae, B. duttonii and B. hispanica circulate alongside at least six species which have not yet been cultured in vectors. Direct diagnosis is hindered by the use of non-specific laboratory tools. Indeed, microscopic observation of Borrelia spirochaeta in smears of peripheral blood taken from febrile patients lacks sensitivity and specificity. Although best visualised using dark-field microscopy, the organisms can also be detected using Wright-Giemsa or acridine orange stains.. PCR-based detection of specific sequences in total DNA extracted from a specimen can be used to discriminate different relapsing fever Borreliae. In our laboratory, we developed a multiplex real-time PCR assay for the specific detection of B. duttonii/recurrentis and B. crocidurae: Multispacer Sequence Typing accurately identified cultured relapsing fever borreliae and revealed diversity among them. Other molecular typing techniques, such as multilocus sequence analysis of tick-borne relapsing fever borreliae, showed the potential risk of human infection in Africa. Recent efforts to culture and sequence relapsing fever borreliae have provided new information for reassessment of the diversity of these bacteria. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry has been reported as a means of identifying cultured borreliae and of identifying both vectors and vectorised pathogens such as detecting relapsing fever borreliae directly in ticks. The lack of a rapid diagnosis test restricts the management of such diseases. We produced monoclonal antibodies against Borrelia crocidurae in order to develop cheap assays for the rapid detection of relapsing fever borreliae. In this paper

  20. The Burden of Tick-Borne Encephalitis in Disability-Adjusted Life Years (DALYs for Slovenia.

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    Renata Šmit

    Full Text Available Tick-borne encephalitis (TBE presents an increasing burden in many parts of Europe, Asian Russia, Siberia, Asian former USSR and Far East. Incidence can be considered as one way to express the burden. A more comprehensive measure concerns disability-adjusted life years (DALYs, better characterizing the full burden of TBE. TBE burden in DALYs has not yet been estimated, nor has it been specified by the Global Burden of Disease (GBD studies.The purpose of the present study is to estimate the burden of TBE in Slovenia, expressed in DALYs, both from the population and individual perspectives. We discuss the impact of TBE burden on public health and potential strategies to reduce this burden in Slovenia.The burden of TBE is estimated by using the updated DALYs' methodology first introduced in the GBD project. The DALYs᾽ calculations are based on the health outcomes of the natural course of the disease being modelled. Corrections for under-reporting and under-ascertainment are applied. The impact of uncertainty in parameters in the model was assessed using sensitivity analyses.From the population perspective, total DALYs amount to 3,450 (167.8 per 100,000 population, while from the individual perspective they amount to 3.1 per case in 2011. Notably, the consequences of TBE present a larger burden than TBE itself.TBE presents a relatively high burden expressed in DALYs compared with estimates for other infectious diseases from the GBD 2010 study for Slovenia. Raising awareness and increasing vaccination coverage are needed to reduce TBE and its consequences.

  1. Tick-borne rickettsial pathogens in ticks and small mammals in Korea.

    Science.gov (United States)

    Kim, Chul-Min; Yi, Ying-Hua; Yu, Do-Hyeon; Lee, Mi-Jin; Cho, Mae-Rim; Desai, Atul R; Shringi, Smriti; Klein, Terry A; Kim, Heung-Chul; Song, Jin-Won; Baek, Luck-Ju; Chong, Sung-Tae; O'guinn, Monica L; Lee, John S; Lee, In-Yong; Park, Jin-Ho; Foley, Janet; Chae, Joon-Seok

    2006-09-01

    In order to investigate the prevalence of tick-borne infectious agents among ticks, ticks comprising five species from two genera (Hemaphysalis spp. and Ixodes spp.) were screened using molecular techniques. Ticks (3,135) were collected from small wild-caught mammals or by dragging/flagging in the Republic of Korea (ROK) and were pooled into a total of 1,638 samples (1 to 27 ticks per pool). From the 1,638 tick samples, species-specific fragments of Anaplasma phagocytophilum (1 sample), Anaplasma platys (52 samples), Ehrlichia chaffeensis (29 samples), Ehrlichia ewingii (2 samples), Ehrlichia canis (18 samples), and Rickettsia rickettsii (28 samples) were amplified by PCR assay. Twenty-one pooled and individual tick samples had mixed infections of two (15 samples) or three (6 samples) pathogens. In addition, 424 spleen samples from small captured mammals (389 rodents, 33 insectivores, and 2 weasels) were screened for selected zoonotic pathogens. Species-specific DNA fragments of A. phagocytophilum (110 samples), A. platys (68 samples), E. chaffeensis (8 samples), E. ewingii (26 samples), E. canis (51 samples), and Rickettsia sp. (22 samples) were amplified by PCR assay. One hundred thirty small mammals had single infections, while 4, 14, and 21 striped field mice (Apodemus agrarius) had mixed infections of four, three, and two pathogens, respectively. Phylogenetic analysis based on nucleotide sequence comparison also revealed that Korean strains of E. chaffeensis clustered closely with those from China and the United States, while the Rickettsia (rOmpA) sequences clustered within a clade together with a Chinese strain. These results suggest that these agents should be considered in differential diagnosis while examining cases of acute febrile illnesses in humans as well as animals in the ROK.

  2. Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases.

    Science.gov (United States)

    Cisak, Ewa; Wójcik-Fatla, Angelina; Zając, Violetta; Dutkiewicz, Jacek

    2012-01-01

    A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides. PMID:23311778

  3. Depletion of Plasma Gelsolin in Patients with Tick-Borne Encephalitis and Lyme Neuroborreliosis

    Science.gov (United States)

    Kułakowska, Alina; Zajkowska, Joanna M.; Ciccarelli, Nicholas J.; Mroczko, Barbara; Drozdowski, Wiesław; Bucki, Robert

    2011-01-01

    Background/Aims Cell damage during the course of inflammation results in cytoplasmic actin release, which if not eliminated by the extracellular actin scavenger system, composed of gelsolin and vitamin D binding protein, can cause dysfunction of hemostasis and toxicity towards surrounding cells. In this study, we test the hypothesis that an inflammatory reaction induced by central nervous system infections such as tick-borne encephalitis (TBE) or Lyme neuroborreliosis (LNB) will result in plasma gelsolin concentration changes in the blood and cerebrospinal fluid (CSF). Methods Quantitative Western blot was used to determine gelsolin levels in 58 samples, which include: 29 patients without infection (diagnosed with conditions such as idiopathic cephalalgia, idiopathic Bell's facial nerve palsy and ischialgia due to discopathy in which standard CSF diagnostic tests show no abnormalities), 12 patients diagnosed with TBE, and 17 patients diagnosed with LNB sub forma meningitis. Results and Conclusion The gelsolin concentration in the blood of patients with TBE (163.2 ± 80.8 μg/ml) and LNB (113.6 ± 56.8 μg/ml) was significantly lower (p < 0.05 and p < 0.001, respectively) compared to the control group (226.3 ± 100.7 μg/ml). Furthermore, there was no statistically significant difference between the CSF gelsolin concentration in patients with TBE (3.9 ± 3.3 μg/ml), LNB (2.9 ± 1.2 μg/ml) and the control group (3.7 ± 3.3 μg/ml). An observed decrease in gelsolin concentration in the blood of TBE and LNB patients supports previous findings indicating the involvement of gelsolin in the pathophysiology of an inflammatory response. Therefore, evaluation of blood gelsolin concentration and administration of recombinant plasma gelsolin might provide a new tool to develop diagnostic and therapeutic strategies for TBE and LNB. PMID:21389683

  4. The molecular biology of tick-borne encephalitis virus. Review article.

    Science.gov (United States)

    Heinz, F X; Mandl, C W

    1993-10-01

    Tick-borne encephalitis (TBE) virus is a member of the flavivirus genus and the family Flaviviridae. Like other flaviviruses such as yellow fever, Japanese encephalitis or the dengue viruses, it is an important human pathogen, endemic in many European countries, Russia and China. The disease can be effectively prevented by vaccination with a formalin-inactivated whole virus vaccine. In recent years major advances have been made in the understanding of the molecular biology of TBE virus, including the complete sequence analysis of the genomic RNA of the European and Far Eastern strains. As shown in these studies, the virion RNA contains a single long open reading frame that codes for the structural proteins at the 5' end and the nonstructural proteins at the 3' end. Co- and posttranslational cleavages by a viral and cellular proteases lead to the formation of individual viral proteins. The mature virion is composed of an isometric capsid surrounded by a lipid envelope with two membrane-associated proteins. One of these, protein E, is of paramount importance for several important viral functions, especially during the entry phase of the viral life cycle. Protein E is also responsible for the induction of a protective immune response. A detailed map of antigenic sites has been established and the structure of an anchor-free form of E is currently being investigated by X-ray diffraction analysis. Understanding the molecular basis of the functions of this protein together with the knowledge of its three-dimensional structure may provide clues for developing specific antiviral agents. Protein E has also been shown to be an important determinant of virulence, with single amino acid substitutions at selected sites leading to attenuation. Engineering of such mutations into cDNA clones to produce new recombinant viruses may open up new avenues for the development of live vaccines. PMID:8267950

  5. Prevalence of antibodies against tick-borne encephalitis virus in wild game from Saxony, Germany.

    Science.gov (United States)

    Balling, Anneliese; Plessow, Uta; Beer, Martin; Pfeffer, Martin

    2014-10-01

    Tick-borne encephalitis (TBE) is the most important tick-transmitted viral disease in Europe and is caused by the flavivirus TBE-virus (TBEV). In Germany TBE is unevenly distributed with the vast majority of cases occurring in the south in so-called risk areas defined as regions with an incidence of at least 1 case in 100,000 inhabitants. However, in low endemic areas with lesser TBE cases the respective risk assessment is hard to achieve. We therefore intend to use the prevalence of antibodies against TBEV in wildlife to trace TBEV endemic areas as a surrogate marker for the notification of human cases. This study was conducted in Saxony, Germany, where 34 autochthonous cases were reported since 2001, thereby not allowing a geographic allocation within the state. A total of 1,851 sera from wild boar and 35 sera from roe deer from all Saxon districts shot between April 2011 and March 2013 were screened for the presence of antibodies against TBEV. The overall seropositivity for Saxony was 10.5%. Among the wild boar sera, most positive samples could be found in the districts Meißen (23%) and Vogtlandkreis (20%) followed by Dresden (18%), Erzgebirgskreis and Görlitz (both 10%). We conclude that seroprevalence studies in game animals represent a promising surrogate marker and should be considered for future determination of risk areas. Although we are currently unable to explain the discrepancy of the few human cases and the high seroprevalence in some districts, vaccination against TBE should be considered for people planning outdoor activities in Dresden, Meißen or Vogtlandkreis. PMID:25113988

  6. Theileria sp. OT3 and other tick-borne pathogens in sheep and ticks in Italy: molecular characterization and phylogeny.

    Science.gov (United States)

    Giangaspero, A; Marangi, M; Papini, R; Paoletti, B; Wijnveld, M; Jongejan, F

    2015-02-01

    PCR Reverse Line Blot (RLB) hybridization and sequencing were used to determine the dynamics of infection with tick-borne pathogens in one hundred apparently healthy sheep in Italy. Blood samples were tested once prior to the onset of the grazing season (June 2010) and once after the end of the grazing season (August 2010). Ticks collected from sheep and from the vegetation were also tested by PCR/RLB. Before grazing, 56% of the sheep harbored several tick-borne pathogens: Anaplasma ovis was the most prevalent (41%), followed by A. ovis co-infected with Theileria sp. OT3 (14%). After grazing, 87% of sheep were positive for A. ovis alone (41%), co-infected with Theileria sp. OT3 (8%) or co-infected with Babesia motasi (5%). Other sheep were infected with Anaplasma phagocytophilum alone (20%), co-infected with B. motasi (7%) or with Theileria sp. OT3 (5%) (p<0.001). After grazing, sheep were significantly more infected with tick-borne pathogens than before grazing. Ticks collected were all Haemaphysalis punctata (n-89) and 36% were positive for A. ovis, Ehrlichia ovina and A. ovis combined with A. phagocytophilum. Phylogenetic analysis including isolates from countries in the Mediterranean Basin show circulation of the same variants of Theileria sp. OT3, whereas two different geographical origins for the isolates of A. ovis and A. phagocytophilum were identified. This is the first report from Italy of Theileria sp. OT3 in sheep, whereas the detection of Ehrlichia ovina in ticks is worth noting, and the presence of A. phagocytophilum in sheep and in ticks poses a potential public health risk. PMID:25448422

  7. Incidence of Cercopithifilaria bainae in dogs and probability of co-infection with other tick-borne pathogens.

    Directory of Open Access Journals (Sweden)

    Rafael Antonio Nascimento Ramos

    Full Text Available BACKGROUND: Cercopithifilaria bainae is a filarioid parasite that infects dogs, being transmitted by Rhipicephalus sanguineus group ticks in many countries of the Mediterranean basin. This study assessed the incidence density rate (IDR of infection by C. bainae in dogs and the probability of co-infection with other tick-borne pathogens (i.e., Anaplasma platys, Babesia vogeli and Hepatozoon canis, in an area of high endemicity in southern Italy. METHODOLOGY/PRINCIPAL FINDINGS: From March 2011 to October 2012, a field study involving 58 young dogs naturally exposed to tick infestation was conducted. Skin and blood samples obtained from each dog six times during an 18-month period were tested for C. bainae by parasite detection within skin snip sediments, with subsequent confirmation through PCR and DNA sequencing. Dogs examined monthly for ticks and A. platys, B. vogeli and H. canis were microscopically and/or molecularly diagnosed and after the first and the second summer seasons, the IDR for positive animal-month at risk was 3.8% and 1.7% in November 2011 and October 2012, respectively. All 58 C. bainae-infected dogs were simultaneously infected with at least one other tick-borne pathogen. After the first summer season (assessment in November 2011, a C. bainae-infected dog had a 33% probability of being infected with H. canis or A. platys, whereas after the second tick season (assessment in October 2012 the probability of co-infection was 78%, 22% and 11% for H. canis, A. platys and B. vogeli, respectively. CONCLUSIONS: Our data indicate that tick-infested dogs are at risk of acquiring infection by C. bainae. In addition, the detection of C. bainae microfilariae indicates a prior tick exposure and, should stimulate testing for other tick-borne disease causing pathogens.

  8. Exploring of primate models of tick-borne flaviviruses infection for evaluation of vaccines and drugs efficacy.

    Directory of Open Access Journals (Sweden)

    Natalia S Pripuzova

    Full Text Available Tick-borne encephalitis virus (TBEV is one of the most prevalent and medically important tick-borne arboviruses in Eurasia. There are overlapping foci of two flaviviruses: TBEV and Omsk hemorrhagic fever virus (OHFV in Russia. Inactivated vaccines exist only against TBE. There are no antiviral drugs for treatment of both diseases. Optimal animal models are necessary to study efficacy of novel vaccines and treatment preparations against TBE and relative flaviviruses. The models for TBE and OHF using subcutaneous inoculation were tested in Cercopithecus aethiops and Macaca fascicularis monkeys with or without prior immunization with inactivated TBE vaccine. No visible clinical signs or severe pathomorphological lesions were observed in any monkey infected with TBEV or OHFV. C. aethiops challenged with OHFV showed massive hemolytic syndrome and thrombocytopenia. Infectious virus or viral RNA was revealed in visceral organs and CNS of C. aethiops infected with both viruses; however, viremia was low. Inactivated TBE vaccines induced high antibody titers against both viruses and expressed booster after challenge. The protective efficacy against TBE was shown by the absence of virus in spleen, lymph nodes and CNS of immunized animals after challenge. Despite the absence of expressed hemolytic syndrome in immunized C. aethiops TBE vaccine did not prevent the reproduction of OHFV in CNS and visceral organs. Subcutaneous inoculation of M. fascicularis with two TBEV strains led to a febrile disease with well expressed viremia, fever, and virus reproduction in spleen, lymph nodes and CNS. The optimal terms for estimation of the viral titers in CNS were defined as 8-16 days post infection. We characterized two animal models similar to humans in their susceptibility to tick-borne flaviviruses and found the most optimal scheme for evaluation of efficacy of preventive and therapeutic preparations. We also identified M. fascicularis to be more susceptible to

  9. Role of sand lizards in the ecology of Lyme and other tick-borne diseases in the Netherlands

    Directory of Open Access Journals (Sweden)

    Spitzen - van der Sluijs Annemarieke

    2010-05-01

    Full Text Available Abstract Background Lizards are considered zooprophylactic for almost all Borrelia burgdorferi species, and act as dilution hosts in parts of North America. Whether European lizards significantly reduce the ability of B. burgdorferi to maintain itself in enzootic cycles, and consequently decrease the infection rate of Ixodes ricinus ticks for B. burgdorferi and other tick-borne pathogens in Western Europe is not clear. Results Ticks were collected from sand lizards, their habitat (heath and from the adjacent forest. DNA of tick-borne pathogens was detected by PCR followed by reverse line blotting. Tick densities were measured at all four locations by blanket dragging. Nymphs and adult ticks collected from lizards had a significantly lower (1.4% prevalence of B. burgdorferi sensu lato, compared to questing ticks in heath (24% or forest (19%. The prevalence of Rickettsia helvetica was significantly higher in ticks from lizards (19% than those from woodland (10% whereas neither was significantly different from the prevalence in ticks from heather (15%. The prevalence of Anaplasma and Ehrlichia spp in heather (12% and forest (14% were comparable, but significantly lower in ticks from sand lizards (5.4%. The prevalence of Babesia spp in ticks varied between 0 and 5.3%. Tick load of lizards ranged from 1 - 16. Tick densities were ~ 5-fold lower in the heather areas than in woodlands at all four sites. Conclusions Despite their apparent low reservoir competence, the presence of sand lizards had insignificant impact on the B. burgdorferi s.l. infection rate of questing ticks. In contrast, sand lizards might act as reservoir hosts for R. helvetica. Remarkably, the public health risk from tick-borne diseases is approximately five times lower in heather than in woodland, due to the low tick densities in heather.

  10. 儿童蜱传脑炎研究进展%Advances on tick-borne encephalitis in children

    Institute of Scientific and Technical Information of China (English)

    刘琦(综述); 陈益平(审校)

    2015-01-01

    蜱传脑炎是儿童中枢神经系统感染性疾病。儿童病情较轻,极少数可能出现永久性损伤,遗留神经系统后遗症。该文介绍蜱传脑炎的流行病学和临床特征,并总结生物学和病毒学方面,以更好地了解病毒的生命周期和传播。在我国蜱传脑炎病毒是通过全沟硬蜱传播的一种黄病毒,可引起急性脑膜脑炎。血清学诊断通常是简单直接的。该病无特效治疗存在,免疫是主要预防措施。%Tick-borne encephalitis ( TBE) is a well-known central nervous system ( CNS) infection in children. The disease in children is generally milder,although severe illness may occur and even lead to perma-nent impairment of the quality of life due to neuropsychological sequelae. We review the epidemiological and clinical characteristics of tick-borne encephalitis,and summarise biological and virological aspects that are impor-tant for understanding the life-cycle and transmission of the virus. Tick-borne encephalitis virus is a flavivirus that is transmitted by ixodes persulcatus. Tick-borne encephalitis causes acute meningoencephalitis. The serologi-cal diagnosis is usually straightforward. No specific treatment for the disease exists,and immunisation is the main preventive measure.

  11. [Seroprevalence of Borrelia burgdorferi and tick-borne encephalitis virus in a rural area of Samsun, Turkey].

    Science.gov (United States)

    Aslan Başbulut, Eşe; Gözalan, Ayşegül; Sönmez, Cemile; Cöplü, Nilay; Körhasan, Berrin; Esen, Berrin; Akın, Levent; Ertek, Mustafa

    2012-04-01

    Lyme disease or lyme borreliosis is a zoonosis caused by Borrelia burgdorferi transmitted by ticks, especially Ixodes species. Lyme borreliosis is a multi-systemic disease that invades the skin, musculoskeletal, cardiovascular and central nervous systems. Tick-borne encephalitis (TBE) is an important arboviral infection caused by tick-borne encephalitis virus (TBEV). The central nervous system is affected and the disease most often manifests as meningitis, encephalitis or meningoencephalitis. Previous studies have shown that B.burgdorferi and TBEV can be transmitted by the same tick species (Ixodes ricinus). Although the geographic location and climate is similar to some south-eastern European countries where lyme borreliosis and TBE have been reported, the incidence and prevalence of these diseases in Turkey still remain unclear. The aim of this study was to determine the seroprevelance of B.burgdorferi and TBEV in healthy population in Tekkeköy (41° 8-13' North; 36° 24-31' East), a district of Samsun province, Turkey with evidence of tick-borne disease and to explore the possible correlations of life styles of healthy individuals and prevelance. The cross-sectional study population included 419 people selected using a random proportional sampling method. All participants were asked at interview to complete a questionnaire and peripheral blood samples were collected. From the blood samples, B.burgdorferi IgG and IgM antibodies were evaluated using commercial ELISA (Euroimmun, Germany) and confirmed with Western blot (WB, Euroimmun, Germany). ELISA method was also used to asses IgM and IgG antibodies against TBEV, and neutralization test was used for confirmation. Of the 419 samples, 17 (4%) were positive for B.burgdorferi IgG by ELISA, however 14 (14/419; 3.3%) of them were confirmed by WB. B.burgdorferi seropositivity was higher among people living in rural areas, at an altitude of ≥ 400 meters and in locations ecologically suitable for wild boar and rabbits

  12. Research Progress of Ticks and Tick-borne Disease%蜱及蜱传病的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘琪; 王伟利; 孟庆峰

    2013-01-01

    对蜱的种属、生物学特性和传播疾病及诊断方法进行了综述.针对蜱及常见蜱传病的特性,有助于找到切实有效的方法,从根本上消灭蜱所带来的危害.%The genus, biological characteristics of tick and diagnosis methods for tick-borne disease were reviewed. Aiming at characteristics of tick and several common tick-bome diseases, effective methods were easy to found, so as to eliminate damages brought by tick.

  13. Tick-borne pathogens and associated co-infections in ticks collected from domestic animals in central China

    OpenAIRE

    Chen, Zhuo; Liu, Qin; Liu, Ji-Qi; Xu, Bian-Li; Lv, Shan; Xia, Shang; Zhou, Xiao-Nong

    2014-01-01

    Background Ticks can transmit a number of pathogens to humans and domestic animals. Tick borne diseases (TBDs), which may lead to organ failure and death have been recently reported in China. 98.75% of the total cases (>1000) in Henan provinces have been reported in Xinyang city. Therefore, the aims of this study were to investigate the fauna of ticks and detect the potential pathogens in ticks in Xinyang, the region of central China. Methods Ticks were collected from 10 villages of Xinyang f...

  14. Genetic description of a tick-borne encephalitis virus strain Sofjin with the longest history as a vaccine strain

    OpenAIRE

    Vorovitch, M. F.; Kozlovskaya, L. I.; Romanova, L. Iu.; Chernokhaeva, L. L.; Ishmukhametov, A. A.; Karganova, G. G.

    2015-01-01

    Vaccines based on the strain Sofjin of the Far-Eastern tick-borne encephalitis virus (TBEV) subtype have been used for TBE prophylaxis for over 50 years in Russia and neighboring countries. On the wide territory, where all known TBEV subtypes are circulating, the cultural, purified, concentrated, inactivated TBE vaccine Moscow has been shown to be safe and efficacious in a massive immunization. In the present work, we describe the genome of the vaccine strain Sofjin. We have shown that it dif...

  15. [Two cases of tick-borne tularemia in Yozgat province, Turkey].

    Science.gov (United States)

    Yeşilyurt, Murat; Kılıç, Selçuk; Cağaşar, Ozlem; Celebi, Bekir; Gül, Serdar

    2011-10-01

    node on left side. The tick, which has removed from the scalp lesion by the patient himself was identified as Dermacentor spp. The suspected diagnosis of ulceroglandular tularemia was confirmed by 1/2560 titer positivity obtained with MAT. Gentamicin (5 mg/kg/day, PO) was initiated for the treatment of both patients, however, LAP did persist in both of them requiring abscess drainage and prolonged treatment with gentamicin following a 14-day course of ciprofloxacin (1500 mg/day, PO). LAP decreased after medical treatment and repetitive drainage procedures. The patients recovered completely without sequela. These cases, to the best of our knowledge, who were the first confirmed tick-borne tularemia cases in our country, were presented to call attention to a different mode of transmission for F.tularensis. PMID:22090307

  16. Tick repellents and acaricides of botanical origin: a green roadmap to control tick-borne diseases?

    Science.gov (United States)

    Benelli, Giovanni; Pavela, Roman; Canale, Angelo; Mehlhorn, Heinz

    2016-07-01

    Arthropods are dangerous vectors of agents of deadly diseases, which may hit as epidemics or pandemics in the increasing world population of humans and animals. Among them, ticks transmit more pathogen species than any other group of blood-feeding arthropods worldwide. Thus, the effective and eco-friendly control of tick vectors in a constantly changing environment is a crucial challenge. A number of novel routes have been attempted to prevent and control tick-borne diseases, including the development of (i) vaccines against viruses vectored by ticks; (ii) pheromone-based control tools, with special reference to the "lure and kill" techniques; (iii) biological control programmes relying on ticks' natural enemies and pathogens; and (iv) the integrated pest management practices aimed at reducing tick interactions with livestock. However, the extensive employment of acaricides and tick repellents still remains the two most effective and ready-to-use strategies. Unfortunately, the first one is limited by the rapid development of resistance in ticks, as well as by serious environmental concerns. On the other hand, the exploitation of plants as sources of effective tick repellents is often promising. Here, we reviewed current knowledge concerning the effectiveness of plant extracts as acaricides or repellents against tick vectors of public health importance, with special reference to Ixodes ricinus, Ixodes persulcatus, Amblyomma cajennense, Haemaphysalis bispinosa, Haemaphysalis longicornis, Hyalomma anatolicum, Hyalomma marginatum rufipes, Rhipicephalus appendiculatus, Rhipicephalus (Boophilus) microplus, Rhipicephalus pulchellus, Rhipicephalus sanguineus and Rhipicephalus turanicus. Eighty-three plant species from 35 botanical families were selected. The most frequent botanical families exploited as sources of acaricides and repellents against ticks were Asteraceae (15 % of the selected studies), Fabaceae (9 %), Lamiaceae (10 %), Meliaceae (5 %), Solanaceae (6

  17. Survey for hantaviruses, tick-borne encephalitis virus, and Rickettsia spp. in small rodents in Croatia.

    Science.gov (United States)

    Svoboda, Petra; Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; Margaletić, Josip; Essbauer, Sandra

    2014-07-01

    In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunofluorescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava-Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas.

  18. To what extent has climate change contributed to the recent epidemiology of tick-borne diseases?

    Science.gov (United States)

    Randolph, Sarah E

    2010-02-10

    There is no doubt that all vector-borne diseases are very sensitive to climatic conditions. Many such diseases have shown marked increases in both distribution and incidence during the past few decades, just as human-induced climate change is thought to have exceeded random fluctuations. This coincidence has led to the general perception that climate change has driven disease emergence, but climate change is the inevitable backdrop for all recent events, without implying causality. Coincidence and causality can be disentangled using tick-borne encephalitis (TBE) as a test case, based on the excellent long-term data for this medically significant European disease system. Detailed analysis of climate records since 1970 has revealed abrupt temperature increases just prior to the dramatic upsurge in TBE incidence in many parts of central and eastern Europe. Furthermore, the seasonal patterns of this temperature change are such as might have favoured the transmission of TBE virus between co-feeding ticks. Nevertheless, the pattern of climate change is too uniform to explain the marked heterogeneity in the timing and degree of TBE upsurge, for example in different counties within each of the Baltic countries. Recent decreases as well as increases in TBE incidence must also be taken into account. Instead of a single cause, a network of interacting factors, acting synergistically but with differential force in space and time, would generate this epidemiological heterogeneity. From analysis of past and present events, it appears that human behavioural factors have played a more significant role than purely biological enzootic factors, although there is an explicit causal linkage from one to the other. This includes a range of abiotic and biotic environmental factors, together with human behaviour determined by socio-economic conditions. Many of the abrupt changes followed from the shift from planned to market economies with the fall of Soviet rule. Comparisons between eight

  19. Survey for hantaviruses, tick-borne encephalitis virus, and Rickettsia spp. in small rodents in Croatia.

    Science.gov (United States)

    Svoboda, Petra; Dobler, Gerhard; Markotić, Alemka; Kurolt, Ivan-Christian; Speck, Stephanie; Habuš, Josipa; Vucelja, Marko; Krajinović, Lidija Cvetko; Tadin, Ante; Margaletić, Josip; Essbauer, Sandra

    2014-07-01

    In Croatia, several rodent- and vector-borne agents are endemic and of medical importance. In this study, we investigated hantaviruses and, for the first time, tick-borne encephalitis virus (TBEV) and Rickettsia spp. in small wild rodents from two different sites (mountainous and lowland region) in Croatia. In total, 194 transudate and tissue samples from 170 rodents (A. flavicollis, n=115; A. agrarius, n=2; Myodes glareolus, n=53) were tested for antibodies by indirect immunofluorescence assays (IIFT) and for nucleic acids by conventional (hantaviruses) and real-time RT-/PCRs (TBEV and Rickettsia spp.). A total of 25.5% (24/94) of the rodents from the mountainous area revealed specific antibodies against hantaviruses. In all, 21.3% (20/94) of the samples from the mountainous area and 29.0% (9/31) from the lowland area yielded positive results for either Puumala virus (PUUV) or Dobrava-Belgrade virus (DOBV) using a conventional RT-PCR. All processed samples (n=194) were negative for TBEV by IIFT or real-time RT-PCR. Serological evidence of rickettsial infection was detected in 4.3% (4/94) rodents from the mountainous region. Another 3.2% (3/94) rodents were positive for Rickettsia spp. by real-time PCR. None of the rodents (n=76) from the lowland area were positive for Rickettsia spp. by real-time PCR. Dual infection of PUUV and Rickettsia spp. was found in one M. glareolus from the mountainous area by RT-PCR and real-time PCR, respectively. To our knowledge, this is the first detection of Rickettsia spp. in small rodents from Croatia. Phylogenetic analyses of S- and M-segment sequences obtained from the two study sites revealed well-supported subgroups in Croatian PUUV and DOBV. Although somewhat limited, our data showed occurrence and prevalence of PUUV, DOBV, and rickettsiae in Croatia. Further studies are warranted to confirm these data and to determine the Rickettsia species present in rodents in these areas. PMID:24866325

  20. Veterinary entomology, colonial science and the challenge of tick-borne diseases in South Africa during the late nineteenth and early twentieth centuries.

    Science.gov (United States)

    Brown, K

    2008-12-01

    This article provides an historical overview of developments in veterinary entomology during the late nineteenth and early twentieth centuries. During that period state employed entomologists and veterinary scientists discovered that ticks were responsible for transmitting a number of livestock diseases in South Africa. Diseases such as heartwater, redwater and gallsickness were endemic to the country. They had a detrimental effect on pastoral output, which was a mainstay of the national economy. Then in 1902 the decimating cattle disease East Coast fever arrived making the search for cures or preventatives all the more urgent. Vaccine technologies against tick-borne diseases remained elusive overall and on the basis of scientific knowledge, the South African state recommended regularly dipping animals in chemical solutions to destroy the ticks. Dipping along with quarantines and culls resulted in the eradication of East Coast fever from South Africa in the early 1950s. However, from the 1930s some ticks evolved a resistance to the chemical dips meaning that diseases like redwater were unlikely to be eliminated by that means. Scientists toiled to improve upon existing dipping technologies and also carried out ecological surveys to enhance their ability to predict outbreaks. Over the longer term dipping was not a panacea and ticks continue to present a major challenge to pastoral farming.

  1. SiRNA Inhibits Replication of Langat Virus, a Member of the Tick-Borne Encephalitis Virus Complex in Organotypic Rat Brain Slices

    Science.gov (United States)

    Maffioli, Carola; Grandgirard, Denis; Leib, Stephen L.; Engler, Olivier

    2012-01-01

    Tick-borne encephalitis virus is the causative agent of tick-borne encephalitis, a potentially fatal neurological infection. Tick-borne encephalitis virus belongs to the family of flaviviruses and is transmitted by infected ticks. Despite the availability of vaccines, approximately 2000–3000 cases of tick-borne encephalitis occur annually in Europe for which no curative therapy is available. The antiviral effects of RNA mediated interference by small interfering RNA (siRNA) was evaluated in cell culture and organotypic hippocampal cultures. Langat virus, a flavivirus highly related to Tick-borne encephalitis virus exhibits low pathogenicity for humans but retains neurovirulence for rodents. Langat virus was used for the establishment of an in vitro model of tick-borne encephalitis. We analyzed the efficacy of 19 siRNA sequences targeting different regions of the Langat genome to inhibit virus replication in the two in vitro systems. The most efficient suppression of virus replication was achieved by siRNA sequences targeting structural genes and the 3′ untranslated region. When siRNA was administered to HeLa cells before the infection with Langat virus, a 96.5% reduction of viral RNA and more than 98% reduction of infectious virus particles was observed on day 6 post infection, while treatment after infection decreased the viral replication by more than 98%. In organotypic hippocampal cultures the replication of Langat virus was reduced by 99.7% by siRNA sequence D3. Organotypic hippocampal cultures represent a suitable in vitro model to investigate neuronal infection mechanisms and treatment strategies in a preserved three-dimensional tissue architecture. Our results demonstrate that siRNA is an efficient approach to limit Langat virus replication in vitro. PMID:22984545

  2. Seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in zoo animal species in the Czech Republic.

    Science.gov (United States)

    Sirmarová, Jana; Tichá, Lucie; Golovchenko, Marina; Salát, Jiří; Grubhoffer, Libor; Rudenko, Nataliia; Nowotny, Norbert; Růžek, Daniel

    2014-09-01

    This study was conducted to evaluate the prevalence of antibodies against Borrelia bugdorferi (Bb) s.l. and tick-borne encephalitis virus (TBEV) in zoo animals in the Czech Republic. We collected 133 serum samples from 69 animal species from 5 zoos located in different parts of the country. The samples were obtained from even-toed ungulates (n=78; 42 species), odd-toed ungulates (n=32; 11 species), carnivores (n=13; 9 species), primates (n=2, 2 species), birds (n=3; 2 species), and reptiles (n=5; 3 species). A high antibody prevalence (60%) was observed for Bb s.l. On the other hand, only two animals had TBEV-specific antibodies: a markhor (Capra falconeri) and a reindeer (Rangifer tarandus), both from the same zoo, located in an area endemic for TBEV. Both of these animals were also positive for Bb s.l. antibodies. Our results indicate that a high number of animal species in the Czech zoos were exposed to Bb s.l. and that TBEV infection occurred at least in one of the investigated zoos. Considering the pathogenic potential of these two tick-borne pathogens, clinical and serological monitoring should be continued, and therapeutic and preventive measures should be taken when necessary.

  3. Molecular survey of tick-borne pathogens in Ixodid ticks collected from hunted wild animals in Tuscany, Italy

    Institute of Scientific and Technical Information of China (English)

    Valentina; Virginia; Ebani; Fabrizio; Bertelloni; Barbara; Turchi; Dario; Filogari; Domenico; Cerri

    2015-01-01

    Objective: To determine the prevalence of zoonotic tick-borne bacteria in feeding ticks removed from hunted wild animals. Methods: PCR was executed on DNA extracted from 77 tick pools to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii and Rickettsia spp. Results: A total of 432 ticks were collected: 30(6.94%) Haemaphysalis punctata, 72(16.7%) Dermacentor marginatus and 330(76.38%) Ixodes ricinus. For each animal one or two pools of 3 ticks of the same species was constituted. Seventy-seven tick pools were examined by PCR: 58(75.32%) resulted infected and among them 14(18.18%) showed co-infections. In particular, 29(37.66%) pools were positive for Bartonella spp., 23(29.87%) for Anaplasma phagocytophilum, 16(20.78%) for Rickettsia spp., and 5(6.49%) for Borrelia burgdorferi s.l. All samples were negative for Coxiella burnetii. Conclusions: The results demonstrate the presence of several zoonotic tick-borne pathogens in the studied area, and underline the risk of exposure to infections for hunters not only during the outdoor activity, but also when they manipulate hunted animals infested by infected ticks.

  4. Ticks and tick-borne novel bunyavirus collected from the natural environment and domestic animals in Jinan city, East China.

    Science.gov (United States)

    Wang, Dong; Wang, Yongming; Yang, Guoliang; Liu, Huiyuan; Xin, Zheng

    2016-02-01

    Since 2011, 73 cases of the severe fever with thrombocytopenia syndrome, a novel tick-borne disease, have been reported in Jinan city through information system for disease control and prevention. Therefore, this study aimed to investigate the species, distribution, host animals of ticks and tick-borne pathogens. A total of 722 ticks were collected from two types of natural environment and six kinds of domestic animal in Jinan city. All the sampled ticks belonged to the same species, namely Haemaphysalis longicornis, and 94.7% of them were adult. The density of free-living ticks in grassland was nearly six times that in shrub. The prevalence of the goat (53.3%) was highest among the domestic animals. The host body region most frequently parasitized by H. longicornis was the head (77.8%), especially ears and periocular region. Novel bunyavirus was detected on the free-ranging goats in Jinan city. Acaricide treatment with a higher concentration on the ears, periocular region and the groin of domestic animals should be recommended to control the ticks effectively.

  5. [Complications of tick-borne encephalitis in 15-year long experience of the Department of Infectious Diseases and Neuroinfections].

    Science.gov (United States)

    Pancewicz, Sławomir A; Hermanowska-Szpakowicz, Teresa; Kondrusik, Maciej; Zajkowska, Joanna; Grygorczuk, Sambor; Swierzbińska, Renata; Zielenkiewicz-Madejska, Ewa

    2006-01-01

    The clinical features of tick-borne encephalitis (tbe) were analyzed in the group of 477 patients hospitalized in the Department of the Infectious Disease and Neuroinfections of the Medical Academy in Białystok. The group included 31.4% women and 68.6% men, aged from 15 to 76 years. Persistent neurological sequelae were noted in 10.9% of patients: paresis or plegia in 5.66%, spinal dysfunction with lower limbs paraparesis in 1.68%, significant paresis of upper extremities in 0.63%, brachial plexus paresis in 2.31%. Cranial nerves involvement was present in 2.93%, including uni- or bilateral facial nerve palsy in 2.73% and trigeminal nerve involvement in 0.21%. Cerebellar dysfunction was present in 2,09% of patients. No fatal cases of tbe occured.

  6. [Immunotherapy of certain acute and chronic forms of neuroinfections (tick-borne encephalitis, multiple sclerosis, disseminated encephalomyelitis)].

    Science.gov (United States)

    Umanskiĭ, K G; Shishov, A S; Dekonenko, E P; Ashmarina, E E; Andreeva, L S

    1981-01-01

    The pathogenetic community of various viral neuroinfections different in their form and course points out that the use of means targeted at correction of the immune system functions is desirable. As a result of using combined immunotherapy methods the authors have obtained positive results in treating 38 patients suffering from some acute and chronic neuroinfections (grave local forms of acute tick-borne encephalitis, progredient forms of the same encephalitis, disseminated sclerosis, disseminated encephalomyelitis). Interrelations between the immunity factors are studied, and their role in the therapeutic effect obtained is discussed. The scheme and the result of the treatment, as well as general principles of dynamic observation and treatment of those patients are presented.

  7. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

    Science.gov (United States)

    Hay, John; Yeh, Kenneth B.; Dasgupta, Debanjana; Shapieva, Zhanna; Omasheva, Gulnara; Deryabin, Pavel; Nurmakhanov, Talgat; Ayazbayev, Timur; Andryushchenko, Alexei; Zhunushov, Asankadyr; Hewson, Roger; Farris, Christina M.; Richards, Allen L.

    2016-01-01

    Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post-Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review, we describe in detail the successes, challenges, and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan. PMID:26870722

  8. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan.

    Science.gov (United States)

    Hay, John; Yeh, Kenneth B; Dasgupta, Debanjana; Shapieva, Zhanna; Omasheva, Gulnara; Deryabin, Pavel; Nurmakhanov, Talgat; Ayazbayev, Timur; Andryushchenko, Alexei; Zhunushov, Asankadyr; Hewson, Roger; Farris, Christina M; Richards, Allen L

    2016-01-01

    Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post-Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review, we describe in detail the successes, challenges, and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan.

  9. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    John eHay

    2016-02-01

    Full Text Available Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and resources to independently conduct hypothesis driven, peer-review quality research. Strides have been made, however, to increase scientific engagement and capability. Kazakhstan and Kyrgyzstan are examples of countries where biosurveillance research has been successfully conducted, particularly with respect to especially dangerous pathogens. In this review we describe in detail the successes, challenges and opportunities of conducting biosurveillance in Central Asia as exemplified by our recent research activities on ticks and tick-borne diseases in Kazakhstan and Kyrgyzstan.

  10. TRANSLATING ECOLOGY, PHYSIOLOGY, BIOCHEMISTRY, AND POPULATION GENETICS RESEARCH TO MEET THE CHALLENGE OF TICK AND TICK-BORNE DISEASES IN NORTH AMERICA.

    Science.gov (United States)

    Esteve-Gassent, Maria D; Castro-Arellano, Ivan; Feria-Arroyo, Teresa P; Patino, Ramiro; Li, Andrew Y; Medina, Raul F; de León, Adalberto A Pérez; Rodríguez-Vivas, Roger Iván

    2016-05-01

    Emerging and re-emerging tick-borne diseases threaten public health and the wellbeing of domestic animals and wildlife globally. The adoption of an evolutionary ecology framework aimed to diminish the impact of tick-borne diseases needs to be part of strategies to protect human and animal populations. We present a review of current knowledge on the adaptation of ticks to their environment, and the impact that global change could have on their geographic distribution in North America. Environmental pressures will affect tick population genetics by selecting genotypes able to withstand new and changing environments and by altering the connectivity and isolation of several tick populations. Research in these areas is particularly lacking in the southern United States and most of Mexico with knowledge gaps on the ecology of these diseases, including a void in the identity of reservoir hosts for several tick-borne pathogens. Additionally, the way in which anthropogenic changes to landscapes may influence tick-borne disease ecology remains to be fully understood. Enhanced knowledge in these areas is needed in order to implement effective and sustainable integrated tick management strategies. We propose to refocus ecology studies with emphasis on metacommunity-based approaches to enable a holistic perspective addressing whole pathogen and host assemblages. Network analyses could be used to develop mechanistic models involving multihost-pathogen communities. An increase in our understanding of the ecology of tick-borne diseases across their geographic distribution will aid in the design of effective area-wide tick control strategies aimed to diminish the burden of pathogens transmitted by ticks. PMID:27062414

  11. Prevalence of Tick-Borne Pathogens in Ixodes ricinus and Dermacentor reticulatus Ticks from Different Geographical Locations in Belarus

    Science.gov (United States)

    Reye, Anna L.; Stegniy, Valentina; Mishaeva, Nina P.; Velhin, Sviataslau; Hübschen, Judith M.; Ignatyev, George; Muller, Claude P.

    2013-01-01

    Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5–17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved. PMID:23349900

  12. Prevalence of tick-borne pathogens in Ixodes ricinus and Dermacentor reticulatus ticks from different geographical locations in Belarus.

    Science.gov (United States)

    Reye, Anna L; Stegniy, Valentina; Mishaeva, Nina P; Velhin, Sviataslau; Hübschen, Judith M; Ignatyev, George; Muller, Claude P

    2013-01-01

    Worldwide, ticks are important vectors of human and animal pathogens. Besides Lyme Borreliosis, a variety of other bacterial and protozoal tick-borne infections are of medical interest in Europe. In this study, 553 questing and feeding Ixodes ricinus (n = 327) and Dermacentor reticulatus ticks (n = 226) were analysed by PCR for Borrelia, Rickettsia, Anaplasma, Coxiella, Francisella and Babesia species. Overall, the pathogen prevalence in ticks was 30.6% for I. ricinus and 45.6% for D. reticulatus. The majority of infections were caused by members of the spotted-fever group rickettsiae (24.4%), 9.4% of ticks were positive for Borrelia burgdorferi sensu lato, with Borrelia afzelii being the most frequently detected species (40.4%). Pathogens with low prevalence rates in ticks were Anaplasma phagocytophilum (2.2%), Coxiella burnetii (0.9%), Francisella tularensis subspecies (0.7%), Bartonella henselae (0.7%), Babesia microti (0.5%) and Babesia venatorum (0.4%). On a regional level, hotspots of pathogens were identified for A. phagocytophilum (12.5-17.2%), F. tularensis ssp. (5.5%) and C. burnetii (9.1%), suggesting established zoonotic cycles of these pathogens at least at these sites. Our survey revealed a high burden of tick-borne pathogens in questing and feeding I. ricinus and D. reticulatus ticks collected in different regions in Belarus, indicating a potential risk for humans and animals. Identified hotspots of infected ticks should be included in future surveillance studies, especially when F. tularensis ssp. and C. burnetii are involved.

  13. Epidemic Status of Tick and Tick-borne Diseases in Guangdong Province%广东省蜱及蜱传播疾病流行概况

    Institute of Scientific and Technical Information of China (English)

    李娟; 孙铭飞; 姜东续; 吴大成; 吴彩艳; 廖申权; 戚南山; 吕敏娜; 杨丽云; 吴玄光

    2014-01-01

    Tick is an important contributor to vector-borne diseases in China and tick-borne diseases have at-tracted much attention because of their increasing incidence and consequent significant harm to livestock and human health.The special climate,geography resources and dietary habits in Guangdong province provide good conditions for the survival of wildlife as well as increase the chances of people contacting with animals,which is helpful for tick and tick-borne disease spread.The most commonly observed tick species in Guangdong province contain 6 genus and 21 species,and human tick-borne diseases in Guangdong prov-ince include Lyme borreliosis,Q-fever,North-Asia tick-borne spotted fever and human granulocytic ana-plasmosis.Detailed information regarding the current epidemic status of tick and major tick-borne diseases in Guangdong province were reviewed in this paper,which would make efforts in government management and research for the prevention,control,diagnosis,and treatment of tick-borne diseases,as well as for the control of ticks.%蜱在吸食动物血液的同时可传播多种病原体,引发重要的人兽共患蜱传病,给人类健康和畜牧业发展带来严重危害,具有重要的公共卫生意义。近年来不断上升的发病率愈发引起人们的关注。广东省特殊的气候、地理资源环境和饮食习惯不但为野生动植物的生存提供了良好的环境,同时也增加了人与动物接触的机会,为新的蜱种和蜱媒病传播提供了方便。目前广东省分布流行的蜱种主要涉及6属21种,已经证实存在的蜱传病有莱姆病、Q 热、北亚蜱传斑点热和人粒细胞无形体。论文就广东省蜱的种类分布以及蜱传病的流行概况做一综述,为广东省蜱传病的防控措施制定及传播机制研究提供参考。

  14. Communal farmers' perceptions of tick-borne diseases affecting cattle and investigation of tick control methods practiced in Zimbabwe.

    Science.gov (United States)

    Sungirai, Marvelous; Moyo, Doreen Zandile; De Clercq, Patrick; Madder, Maxime

    2016-02-01

    Tick borne diseases (TBDs) are responsible for huge economic losses in cattle production in most African countries where the majority of cattle owners are the resource poor communal farmers. Governments have initiated and co-ordinate tick control programs with farmers required to contribute funds for their sustenance. The success of these programs will hinge upon the involvement of communal farmers in their design, implementation and evaluation. To this end, 313 communal farmers (approximately 8.4% response rate) were interviewed and 3 focus group discussions were carried out in the southern low-veld part of Zimbabwe with the objectives of investigating communal farmers' perceptions on TBDs affecting cattle, level of participation in government initiated tick control programs, other tick control methods practiced, types of acaricides used and their perceived effectiveness. There was a general awareness of TBDs with 67.7% (n=212) farmers being able to describe tick diseases with names or clinical and post-mortem signs. The diseases or problems frequently associated with ticks were cowdriosis (38%, n=119), mastitis (36.7%, n=115), anaplasmosis (36.1%, n=113), body damage (28.4%, n=89), babesiosis (24.6%, n=77) and poor body condition (16.6%, n=52). Cattle mortalities due to TBDs were reported by 23.8% (n=74) of the farmers. The plunge dip was consistently used by farmers (70.3%, n=220) to control ticks. Other tick control methods practiced were the hand spraying (67.4%, n=211), hand dressing (16.6%, n=52), traditional methods (5.4%, n=17), use of pour-ons (4.5%, n=14) and smearing (2.2%, n=7). The formamidines were the most common class of acaricide used (59.4%, n=186), followed by synthetic pyrethroids (29.1%, n=91), macro cyclic lactones (12.8%, n=40) and organophosphates (4.5%, n=14). Most farmers (75.2%, n=231) perceived these acaricides to be effective in controlling ticks. The results of focus group discussions showed that a number of factors influenced the

  15. Communal farmers' perceptions of tick-borne diseases affecting cattle and investigation of tick control methods practiced in Zimbabwe.

    Science.gov (United States)

    Sungirai, Marvelous; Moyo, Doreen Zandile; De Clercq, Patrick; Madder, Maxime

    2016-02-01

    Tick borne diseases (TBDs) are responsible for huge economic losses in cattle production in most African countries where the majority of cattle owners are the resource poor communal farmers. Governments have initiated and co-ordinate tick control programs with farmers required to contribute funds for their sustenance. The success of these programs will hinge upon the involvement of communal farmers in their design, implementation and evaluation. To this end, 313 communal farmers (approximately 8.4% response rate) were interviewed and 3 focus group discussions were carried out in the southern low-veld part of Zimbabwe with the objectives of investigating communal farmers' perceptions on TBDs affecting cattle, level of participation in government initiated tick control programs, other tick control methods practiced, types of acaricides used and their perceived effectiveness. There was a general awareness of TBDs with 67.7% (n=212) farmers being able to describe tick diseases with names or clinical and post-mortem signs. The diseases or problems frequently associated with ticks were cowdriosis (38%, n=119), mastitis (36.7%, n=115), anaplasmosis (36.1%, n=113), body damage (28.4%, n=89), babesiosis (24.6%, n=77) and poor body condition (16.6%, n=52). Cattle mortalities due to TBDs were reported by 23.8% (n=74) of the farmers. The plunge dip was consistently used by farmers (70.3%, n=220) to control ticks. Other tick control methods practiced were the hand spraying (67.4%, n=211), hand dressing (16.6%, n=52), traditional methods (5.4%, n=17), use of pour-ons (4.5%, n=14) and smearing (2.2%, n=7). The formamidines were the most common class of acaricide used (59.4%, n=186), followed by synthetic pyrethroids (29.1%, n=91), macro cyclic lactones (12.8%, n=40) and organophosphates (4.5%, n=14). Most farmers (75.2%, n=231) perceived these acaricides to be effective in controlling ticks. The results of focus group discussions showed that a number of factors influenced the

  16. Why is tick-borne encephalitis increasing? A review of the key factors causing the increasing incidence of human TBE in Swedena

    Directory of Open Access Journals (Sweden)

    Jaenson Thomas GT

    2012-08-01

    Full Text Available Abstract The highest annual incidence of human tick-borne encephalitis (TBE in Sweden ever recorded by the Swedish Institute for Communicable Disease Control (SMI occurred last year, 2011. The number of TBE cases recorded during 2012 up to 6th August 2012 indicates that the incidence for 2012 could exceed that of 2011. In this review of the ecology and epidemiology of TBE in Sweden our main aim is to analyse the possible reasons behind the gradually increasing incidence of human TBE during the last 20 years. The main TBE virus (TBEV vector to humans in Sweden is the nymphal stage of the common tick Ixodes ricinus. The main mode of transmission and maintenance of TBEV in the tick population is considered to be when infective nymphs co-feed with uninfected but infectible larvae on rodents. In most locations the roe deer, Capreolus capreolus is the main host for the reproducing adult I. ricinus ticks. The high number of roe deer for more than three decades has resulted in a very large tick population. Deer numbers have, however, gradually declined from the early 1990s to the present. This decline in roe deer numbers most likely made the populations of small rodents, which are reservoir-competent for TBEV, gradually more important as hosts for the immature ticks. Consequently, the abundance of TBEV-infected ticks has increased. Two harsh winters in 2009–2011 caused a more abrupt decline in roe deer numbers. This likely forced a substantial proportion of the “host-seeking” ticks to feed on bank voles (Myodes glareolus, which at that time suddenly had become very numerous, rather than on roe deer. Thus, the bank vole population peak in 2010 most likely caused many tick larvae to feed on reservoir-competent rodents. This presumably resulted in increased transmission of TBEV among ticks and therefore increased the density of infected ticks the following year. The unusually warm, humid weather and the prolonged vegetation period in 2011 permitted

  17. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle

    OpenAIRE

    Rubaire-Akiiki, C.; J.Okello-Onen; G.W. Nasinyama; Vaarst, M; Kabagambe, E. K.; W. Mwayi; Musunga, D.; Wandukwa, W.

    2004-01-01

    Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-preva...

  18. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: the effect of agro-ecological zone, grazing management and age of cattle.

    Science.gov (United States)

    Rubaire-Akiiki, C; Okello-Onen, J; Nasinyama, G W; Vaarst, M; Kabagambe, E K; Mwayi, W; Musunga, D; Wandukwa, W

    2004-01-01

    Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60%) was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50%) were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified. PMID:15861224

  19. The prevalence of serum antibodies to tick-borne infections in Mbale District, Uganda: The effect of agro-ecological zone, grazing management and age of cattle

    Directory of Open Access Journals (Sweden)

    C. Rubaire-Akiiki

    2004-03-01

    Full Text Available Between August and October 2000, a cross-sectional study was conducted in smallholder dairy farms in Mbale District, Uganda to assess the prevalence of ticks and tick-borne diseases under different grazing systems and agro-ecological zones and understand the circumstances under which farmers operated. A questionnaire was administered to obtain information on dairy farm circumstances and practices. A total of 102 farms were visited and sera and ticks were collected from 478 animals. Sero-prevalence of tick-borne diseases was determined using an enzyme-linked immunoassay. Acaricides were used indiscriminately but the intensity of their use varied with the grazing system and zone. Cattle from different farms mixed for various reasons. During the dry seasons farmers have to get additional fodder from outside their farms that can result in importation of ticks. The prevalence of ticks and serum antibodies to tick-borne infections differed across the grazing systems and zones. The highest serum antibody prevalence (>60% was recorded in the lowland zone under the free range and tethering grazing systems. The lowest tick challenge and serum antibody levels (<50% were recorded in the midland and upland zones under a zero-grazing system. These findings suggest that endemic stability to East Coast Fever, babesiosis and anaplasmosis is most likely to have existed in the lowland zone, particularly, under the tethering and free-range grazing systems. Also, endemic stability for babesiosis existed in the upland zones. Endemic instability for East Coast Fever existed in the midland and upland zones. These structured observational studies are instrumental in planning of control strategies for ticks and tick borne diseases since production systems and the cattle population at high risk of the diseases in the district have been identified.

  20. High-Throughput Procedure for Tick Surveys of Tick-Borne Encephalitis Virus and Its Application in a National Surveillance Study in Switzerland▿

    OpenAIRE

    Gäumann, Rahel; Mühlemann, Kathrin; Strasser, Marc; Beuret, Christian M.

    2010-01-01

    Tick-borne encephalitis (TBE), a viral infection of the central nervous system, is endemic in many Eurasian countries. In Switzerland, TBE risk areas have been characterized by geographic mapping of clinical cases. Since mass vaccination should significantly decrease the number of TBE cases, alternative methods for exposure risk assessment are required. We established a new PCR-based test for the detection of TBE virus (TBEV) in ticks. The protocol involves an automated, high-throughput nucle...

  1. Assessment of antibodies against surface and outer membrane proteins of Anaplasma phagocytophilum in Lyme borreliosis and tick-borne encephalitis paediatric patients.

    Science.gov (United States)

    Krbková, L; Homola, L; Hlaváčová, A; Mikolášek, P; Bednářová, J; Čermáková, Z

    2016-09-01

    To examine evidence of positive antibodies against immunogenic proteins of Anaplasma phagocytophilum in patients with other tick-borne infections and to diagnose possible co-infections, 412 serum specimens were tested by immunoblotting using three specific Anaplasma antigens: surface proteins p44 and Asp62 and outer membrane protein A (OmpA). In total, 284 serum samples from children with Lyme borreliosis and 12 serum samples from children with tick-borne encephalitis were tested. Sera from patients with viral aseptic meningitis (n = 47) and from blood donors (n = 69) were used as controls. Among all serum specimens from patients with tick-borne infections submitted for this study, six samples (2·0%) showed positive IgM reactions and seven samples (2·4%) were IgG positive for A. phagocytophilum by immunoblot. Borderline reactivity was found in 30 samples (10·14%) for IgM and 36 samples (12·2%) for IgG. The difference between patients and blood donors was statistically significant for IgM (P = 0·006) and for IgG (P = 0·0007) antibodies. A statistically significant result was obtained for IgG (P = 0·02) but not for IgM between patients and children with aseptic meningitis. Immunoblot using three specific antigens provides novel information about the positivity of antibodies to A. phagocytophilum in children with other tick-borne infections. Taking into account clinical and laboratory findings of children despite antibody positivity, no case of human granulocytic anaplasmosis was demonstrated. PMID:27180603

  2. Description of Lyme disease-like syndrome in Brazil: is it a new tick borne disease or Lyme disease variation?

    Directory of Open Access Journals (Sweden)

    E. Mantovani

    2007-04-01

    Full Text Available An emerging clinical entity that reproduces clinical manifestations similar to those observed in Lyme disease (LD has been recently under discussion in Brazil. Due to etiological and laboratory particularities it is named LD-like syndrome or LD imitator syndrome. The condition is considered to be a zoonosis transmitted by ticks of the genus Amblyomma, possibly caused by interaction of multiple fastidious microorganisms originating a protean clinical picture, including neurological, osteoarticular and erythema migrans-like lesions. When peripheral blood of patients with LD-like syndrome is viewed under a dark-field microscope, mobile uncultivable spirochete-like bacteria are observed. PCR carried out with specific or conservative primers to recognize Borrelia burgdorferi sensu stricto or the genus Borrelia has been negative in ticks and in biological samples. Two different procedures, respectively involving hematoxylin and eosin staining of cerebrospinal fluid and electron microscopy analysis of blood, have revealed spirochetes not belonging to the genera Borrelia, Leptospira or Treponema. Surprisingly, co-infection with microorganisms resembling Mycoplasma and Chlamydia was observed on one occasion by electron microscopy analysis. We discuss here the possible existence of a new tick-borne disease in Brazil imitating LD, except for a higher frequency of recurrence episodes observed along prolonged clinical follow-up.

  3. Ethnoecological knowledge of ticks and treatment of tick-borne diseases among Maasai people in Northern Tanzania

    Directory of Open Access Journals (Sweden)

    John Kioko

    2015-06-01

    Full Text Available Aim: The aim of this study was to understand traditional knowledge of tick ecology and remedies for tick-borne diseases (TBDs among the Maasai people in northern Tanzania. Materials and Methods: Semi-structured interviews were conducted among specific groups likely to be knowledgeable about tick ecology and TBDs in livestock among the Maasai people. Results: A total of 25 plant species belonging to 18 families were used to treat 8 different TBDs of livestock. Most of the plant species used were of Fabaceae and Burseraceae families. Aloe volkensii, Cissus grandifolia, and Terminalia brownii were the most commonly used plant species. The major plant growth form used was trees, while stems and bark were the main plant parts used. Most treatments were taken orally. Conclusion: Maasai people have substantial knowledge on tick ecology exemplified by their ability to differentiate between different tick species and the range of remedies for each of the TBDs. Because traditional ethnoveterinary remedies are frequently utilized, their effectiveness should be further investigated.

  4. Progress in research on tick-borne diseases and vector ticks%蜱传疾病及其媒介蜱类研究进展

    Institute of Scientific and Technical Information of China (English)

    于志军; 刘敬泽

    2015-01-01

    As obligate blood-sucking ecto-parasites, ticks transmit a great variety of pathogens that have a significant adverse effect on the health of humans, livestock and wild animals. Many ticks and tick-borne diseases are widely distributed in China’s ecologically diverse range of habitats. Human contact with ticks, and the incidence of tick-borne diseases, are increasing with economic development and the increased exploitation of forestry and livestock production. Some new tick-borne diseases are emerging, and the threat posed by ticks to public health is becoming increasingly recognized. This paper describes the occurrence and distribution of the vectors of important tick-borne diseases found in China, which will provide a basis for subsequent systematic research and the integrated control of ticks and tick-borne diseases.%蜱为专性吸血的外寄生动物,传播多种病原体而导致疾病,给人类健康、畜牧业生产及野生动物带来极大危害。我国生态环境多样,蜱及蜱媒疾病种类繁多、自然疫源地分布广泛。随着社会经济发展及林牧业资源的综合开发,人群与媒介蜱的接触机会逐渐增多,蜱传疾病的发病率上升,且不断有新发的蜱传疾病出现,其公共卫生学意义也日益受到重视。本文对我国重要的蜱传疾病、媒介蜱类、分布与特性等进行系统介绍,以期为我国蜱及蜱传疾病的系统研究和综合防控提供理论基础。

  5. Surveillance and study of tick-borne diseases in Zhejiang province, China%浙江省蜱媒传染病监测研究

    Institute of Scientific and Technical Information of China (English)

    凌锋; 龚震宇; 柴程良; 林君芬; 孙继民; 侯娟; 吴海霞; 刘起勇

    2013-01-01

    Objective To investigate the current situation of surveillance and study on the tick - borne diseases in Zhejiang province, China. Methods By literature research and surveillance data analysis, brief descriptive statistic analysis was performed on the literature and annual surveillance data on the tick-borne diseases in Zhejiang that have been published since 2000. Results Through ten years surveillance and study involving serological and molecular biological methods, more than 10 tick-borne diseases or pathogens, including Lyme disease, Anaplasma phagocytophilum, Ehrlichia chaffeensis, spotted fever, Bartonella, Rickettsia mooseri, and Boehner kirk austenite, were confirmed to exist in Zhejiang. Besides, the various tick species and tick-borne diseases were found in as many as 23 counties (county-level cities, districts) in Hangzhou, Jinhua, Lishui, Taizhou, Huzhou, Wenzhou, Quzhou, and Shaoxing in Zhejiang. Conclusion The ticks and tick-borne diseases diversified and widespread in Zhejiang province. Although some achievements have been made in the surveillance and study on tick-borne diseases, the surveillance is neither sufficient nor systematic since lack of proper planning. The related information cannot be fully integrated and utilized for risk assessment and early-waming. It is necessary to establish a platform for tick-borne disease surveillance.%目的 了解浙江省蜱媒传染病监测研究现状.方法 采用文献研究法和监测资料分析相结合,对2000年以来发表的有关浙江省蜱媒传染病的文献及其历年监测资料做简要描述性统计分析.结果 通过近10年来的监测研究,浙江省已通过血清学或分子生物学方法证实存在莱姆病、嗜吞噬细胞无形体、查菲埃立克体、斑点热、巴尔通体等10多种蜱媒传染病,且蜱种群和蜱媒传染病分布较广,涉及到浙江省杭州、金华、丽水、台州、湖州、温州、衢州和绍兴8个市的23个县(市、区).结论 浙江

  6. Rural Residents in China Are at Increased Risk of Exposure to Tick-Borne Pathogens Anaplasma phagocytophilum and Ehrlichia chaffeensis

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    Lijuan Zhang

    2014-01-01

    Full Text Available As emerging tick born rickettsial diseases caused by A. phagocytophilum and E. chaffeensis, anaplasmosis and ehrlichiosis have become a serious threat to human and animal health throughout the world. In particular, in China, an unusual transmission of nosocomial cases of human granulocytic anaplasmosis occurred in Anhui Province in 2006 and more recent coinfection case of A. phagocytophilum and E. chaffeensis was documented in Shandong Province. Although the seroprevalence of human granulocytic anaplasmosis (former human granulocytic ehrlichiosis, HGE has been documented in several studies, these data existed on local investigations, and also little data was reported on the seroprevalence of human monocytic ehrlichiosis (HME in China. In this cross-sectional epidemiological study, indirect immunofluorescence antibody assay (IFA proposed by WHO was used to detect A. phagocytophilum and E. chaffeensis IgG antibodies for 7,322 serum samples from agrarian residents from 9 provinces/cities and 819 urban residents from 2 provinces. Our data showed that farmers were at substantially increased risk of exposure. However, even among urban residents, risk was considerable. Seroprevalence of HGA and HME occurred in diverse regions of the country and tended to be the highest in young adults. Many species of ticks were confirmed carrying A. phagocytophilum organisms in China while several kinds of domestic animals including dog, goats, sheep, cattle, horse, wild rabbit, and some small wild rodents were proposed to be the reservoir hosts of A. phagocytophilum. The broad distribution of vector and hosts of the A. phagocytophilum and E. chaffeensis, especially the relationship between the generalized susceptibility of vectors and reservoirs and the severity of the disease’s clinical manifestations and the genetic variation of Chinese HGA isolates in China, is urgently needed to be further investigated.

  7. A study on ovine tick-borne hemoprotozoan parasites (Theileria and Babesia) in the East Black Sea Region of Turkey.

    Science.gov (United States)

    Altay, Kursat; Dumanli, Nazir; Aktas, Munir

    2012-07-01

    In this study, the frequency of Theileria and Babesia species was assessed via reverse line blotting and blood smear-based diagnostic methods in small ruminants. A total of 201 apparently healthy animals from 26 randomly selected herds located in 4 locations (Artvin, Giresun, Gumushane, and Tokat) of East Black Sea Region of Turkey were investigated for the blood protozoans. In a polymerase chain reaction (PCR), the hypervariable V4 region of the 18S ribosomal RNA gene was amplified with a set of general primers specific for all Theileria and Babesia species. The PCR products were hybridized against catchall and species-specific (Theileria spp., Theileria lestoquardi, Theileria ovis, Theileria sp. OT1, Theileria sp., OT3, Theileria sp., MK, Theileria luwenshuni, Theileria uilenbergi, Babesia spp., Babesia ovis, Babesia motasi, and Babesia crassa) probes. Theileria piroplasms were identified in nine (4.47%) samples by microscopic examination. Reverse line blotting (RLB) detected the infection in 19.90% of the samples. The infection rate of sheep (28.90%) was higher than goats (4.10%). T. ovis, Theileria sp., MK, and Theileria sp. OT3 were detected by RLB. The most prevalent Theileria species was T. ovis (18.90%) followed by Theileria sp. MK (0.99%). Theileria sp. OT3 was detected in one sample (0.43%). A single animal was infected as mix with T. ovis and Theileria sp. MK. The other Theileria (T. lestoquardi, Theileria sp. OT1, T. luwenshuni, and T. uilenbergi) and Babesia (B. ovis, B. motasi, and B. crassa) species were not detected. This study is the first molecular survey on ovine tick-borne protozoans in East Black Sea Region of Turkey.

  8. Application of nuclear and related techniques to the diagnosis and control of tick-borne parasitic diseases of livestock

    International Nuclear Information System (INIS)

    Solid-phase adsorption of semi-defined antigens on plastic matrices and detection of antibodies with sensitive marker systems (radioimmunoassay (RIA) and enzymeimmunoassay (EIA)) have now been applied to the detection of antibodies to some of the diseases. In particular, an RIA utilizing the lysate of Babesia bovis-infected erythrocytes as antigen has been developed. The sensitivity of this test is shown by its ability to detect antibodies in animals 4 years after they had received a single infection. An RIA of similar sensitivity has also been developed for detection of A. marginalis antibodies. Sera from singly infected cattle are all positive after 2 years and 85% are still positive after 3 years. Control of two tick-borne haemoparasitic diseases by vaccination (B. bovis and B. bigemina) has been largely restricted to one country, Australia. This vaccine has a number of disadvantages, which include thermolability and reversion to both virulence and tick transmission. The problem of inducing a stable avirulent state has been attempted in four Babesia species: B. bigemina, B. bovis, B. divergens and B. major. In general, irradiating live organisms with 350 Gy gamma irradiation from a 60CO source induced a stable avirulent organism which, upon infection of susceptible animals, resulted in a mild disease; these animals were subsequently strongly protected against virulent homologous or heterologous challenge. The new direction for production of vaccines suitable for widespread dissemination is in the field of synthetic vaccines produced by either genetic engineering or peptide synthesis. Already a number of protective antigens have been purified from B. bovis and one of these has also been shown to be common to B. bigemina. Use of nuclear techniques in the isolation of these antigens and in their subsequent production by recombinant DNA techniques is discussed

  9. Reducing Tick-Borne Disease in Alabama: Linking Health Risk Perception with Spatial Analysis Using the NASA Earth Observing System

    Science.gov (United States)

    Hemmings, S.; Renneboog, N.; Firsing, S.; Capilouto, E.; Harden, J.; Hyden, R.; Tipre, M.; Zhang, Y.

    2010-01-01

    Lyme disease (LD) accounts for most vector-borne disease reports in the U.S., and although its existence in Alabama remains controversial, other tick-borne illnesses (TBI) such as Southern Tick-Associated Rash Illness (STARI) pose a health concern in the state. Phase One of the Marshall Space Flight Center-UAB DEVELOP study of TBI identified the presence of the chain of infection for LD (Ixodes scapularis ticks carrying Borrelia burgdorferi bacteria) and STARI (Amblyomma americanum ticks and an as-yet-unconfirmed agent) in Alabama. Both LD and STARI are associated with the development of erythema migrans rashes around an infected tick bite, and while treatable with oral antibiotics, a review of educational resources available to state residents revealed low levels of prevention information. To improve prevention, recognition, and treatment of TBI in Alabama, Phase Two builds a health communication campaign based on vector habitat mapping and risk perception assessment. NASA Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery identified likely tick habitats using remotely sensed measurements of vegetation vigor (Normalized Difference Vegetation Index) and soil moisture. Likely tick habitats, identified as those containing both high vegetation density and soil moisture, included Oak Mountain State Park, Bankhead National Forest, and Talladega National Forest. To target a high-risk group -- outdoor recreation program participants at Alabama universities -- the study developed a behavior survey instrument based on existing studies of LD risk factors and theoretical constructs from the Social Ecological Model and Health Belief Model. The survey instrument was amended to include geographic variables in the assessment of TBI knowledge, attitudes, and prevention behaviors, and the vector habitat model will be expanded to incorporate additional environmental variables and in situ data. Remotely sensed environmental data combined with

  10. Abundance of introduced species at home predicts abundance away in herbaceous communities

    Science.gov (United States)

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  11. Molecular detection and characterization of tick-borne pathogens in dogs and ticks from Nigeria.

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    Joshua Kamani

    Full Text Available BACKGROUND: Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%, Ehrlichia canis (12.7%, Rickettsia spp. (8.8%, Babesia rossi (6.6%, Anaplasma platys (6.6%, Babesia vogeli (0.6% and Theileria sp. (0.6% was detected in the blood samples. DNA of E. canis (23.7%, H. canis (21.1%, Rickettsia spp. (10.5%, Candidatus Neoehrlichia mikurensis (5.3% and A. platys (1.9% was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. CONCLUSIONS/SIGNIFICANCE: The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents.

  12. Experimental Transmission of Karshi (Mammalian Tick-Borne Flavivirus Group Virus by Ornithodoros Ticks >2,900 Days after Initial Virus Exposure Supports the Role of Soft Ticks as a Long-Term Maintenance Mechanism for Certain Flaviviruses.

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    Michael J Turell

    Full Text Available Members of the mammalian tick-borne flavivirus group, including tick-borne encephalitis virus, are responsible for at least 10,000 clinical cases of tick-borne encephalitis each year. To attempt to explain the long-term maintenance of members of this group, we followed Ornithodoros parkeri, O. sonrai, and O. tartakovskyi for >2,900 days after they had been exposed to Karshi virus, a member of the mammalian tick-borne flavivirus group.Ticks were exposed to Karshi virus either by allowing them to feed on viremic suckling mice or by intracoelomic inoculation. The ticks were then allowed to feed individually on suckling mice after various periods of extrinsic incubation to determine their ability to transmit virus by bite and to determine how long the ticks would remain infectious. The ticks remained efficient vectors of Karshi virus, even when tested >2,900 d after their initial exposure to virus, including those ticks exposed to Karshi virus either orally or by inoculation.Ornithodoros spp. ticks were able to transmit Karshi virus for >2,900 days (nearly 8 years after a single exposure to a viremic mouse. Therefore, these ticks may serve as a long-term maintenance mechanism for Karshi virus and potentially other members of the mammalian tick-borne flavivirus group.

  13. Retrospective analysis of clinical and laboratory findings in hunting dogs with serologic reactions to tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Ricketsia conorii

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    Spasojević-Kosić Ljubica

    2015-01-01

    Full Text Available Seroprevalence of tick-borne infections in endemic areas could be high. In this study, we investigated the seroprevalence of tick-borne pathogens (Anaplasma phagocytophilum, Borrelia burgdorferi, Babesia canis, Ehrlichia canis, Rickettsia conorii in hunting dogs, naturally infected with one or more pathogens. Serological test results of the investigated animals were compared to those from clinical examination, as well as from haematological and biochemical analyses. A total of 74.14% dogs were seropositive (R.conorii 44.83%, B. canis 32.76%, B. burgdorferi 25.86%, E. canis 13.79%, A. phagocytophilum 8.47%, with 25.86% of dogs seropositive to two pathogens, 15.52% seropositive to three pathogens, and 1.72% of dogs seropositive to four pathogens. Among all registered clinical signs, only pyrexia (p<0.05 and arrhythmia (p<0.05 were significant in seropositive dogs. There was no significant difference between seropositive and seronegative dogs regarding the majority of haematological and biochemical parameters. Statistically significant difference was registered for particular haematological (number of red blood cells and seroreactivity to B. burgdorferi and biochemical parameters (albumin concentration and seroreactivity to E. canis, and AST and seroreactivity to R. conorii but these values were not clinically significant. The high exposure to tick-borne pathogens suggests that ectoparasitic profilactic treatment is not adequate in examined population of hunting dogs. Clinical finding of pyrexia need to be further investigated and explained etiologically, which means that molecular diagnosis should be used in order to identify larger number of pathogens because of the possibility of coinfection. [Projekat Ministarstva nauke Republike Srbije, br. TR 31084

  14. Scientific Opinion on Geographic Distribution of Tick-borne Infections and their Vectors in Europe and the other Regions of the Mediterranean Basin

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    EFSA Panel on Animal Health and Welfare (AHAW

    2010-09-01

    Full Text Available This report is the second of a series of two technical assessments of the role of ticks in transmission of animal diseases and zoonoses in Eurasia. A previous published scientific opinion (EFSA Journal 2010; (88, 1703 focused on two diseases- Crimean-Congo haemorrhagic fever and African swine fever in Eurasia. The aim of this report is to provide an overview of the geographic distribution of tick species which have proven involvement in the transmission of pathogens causing animal diseases and zoonoses in Eurasia. The report provides maps of the region that display the occurrences of ticks and tick-borne pathogens. Systematic literature review of available publications for the last 10 years and other available literature from the experts were used in the retrieval of the geographical reported cases for the presence of ticks and tick borne pathogens. The report includes a description of the factors that influence the dynamics of the relevant tick species and identify possible high-risk areas in the EU for introduction, considering the biological and ecological characteristics of the ticks and their ability to adapt to new areas. Findings from this review have provided evidence of the extent of ticks and tick-borne diseases (TBDs in geographical ranges and the existing risk areas that should be considered as baseline information to assess potential risk of these diseases. The report indicates the validity of using available literature to support the presence of ticks and TBDs without further predication using weather and other environmental factors associated with the ticks‟ survival. The report concluded that animal and human movement play more impact on the spread of the ticks and TBDs. Climate changes and flight pattern of migratory birds can influence the presence and spread of the ticks and TBDs, but have not been determined to be responsible for the widespread distribution of ticks.

  15. Fifty-six Cases with Mediterranean Spotted Fever: Evaluation of Tick-Borne Spotted Diseases in Turkey

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    Özlem Altuntaş Aydın

    2009-12-01

    Full Text Available Background and Design: There are very few clinical series about Mediterranean Spotted Fever (MSF reported from Turkey. Fifty-six patients admitted with fever and rash were diagnosed as MSF in our hospital by clinical, epidemiological signs and Weil-Felix test. We aimed to take attention to the similarities and differencies with another tick-borne infection Crimean-Congo Haemorrhagic Fever (CCHF reported lately in Turkey. Material and Method: Between 1989-2006 years 56 cases were diagnosed as rickettsioses based on epidemiological, clinical and laboratory data. We evaluated the patients retrospectively using by “Diagnosis guide for tick transmitted infections in Europe” prepared by ESCMID Study group for Coxiella, Anaplasma, Rickettsia and Barthonella (ESCAR. We compared two diseases according to the Fisher’s exact test in clinical and laboratory characteristics. Results: Twenty-nine female and 27 male cases reached to 25 point according to ESCAR diagnostic scoring were included into the present study. Age distribution was 20-80 years (mean 43, duration of hospitalization was 1-38 days (mean 8 days. Tache noire was established in most of the cases (64%. All of the cases were recovered by 7-10 days of doxycyclin treatment except one case stayed in hospital for 38 days and died. When it is compared statistically haemorrhagic manifestations, history of tick exposure, nausea and vomiting, thrombocytopenia and leukopenia rates were found higher in CCHF (p<0.05. Conclusion: Whereas MSF and CCHF have similar seasonal and clinical features and transmitted by the tick, the treatment regimen and mortality rates differ. In Istanbul we realised that some of the cases reported as possible CCHF were found to be MSF later, for this reason in patients who has fever and maculopapular rash with a history of tick exposure, MSF should always be kept in mind. The differential diagnosis of CCHF and MSF which can cause epidemics in our country should be done by

  16. Assessing different chemoprophylactic protocols against bovine tick-borne diseases and their influence on the weight gain of calves

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    Sergio Silva da Silva

    2015-08-01

    Full Text Available In the present study, 87 Aberdeen Angus calves were used to assess the effects of low dose, agent-specific drugs on weight gain after a babesiosis and anaplasmosis outbreak. All animals were weighed on weaning (day –34 and again on day zero, with a mean (on day zero of 223.46 Kg and an average individual daily weight gain (ADG of 0.258 Kg. The animals were then separated in three groups: G1 was composed of 37 calves with below average ADG; G2 was composed of 35 animals with below average ADG; and G3 was composed of 15 animals with above average ADG. On day zero animals in G1 were treated with 1.17 mg Kg-1 of diminazene diaceturate and 6.7 mg Kg-1 of oxytetracycline; those in G2 were treated with 1.2 mg Kg-1 of imidocarb dipropionate; and those in G3 were not treated. The animals were then monitored daily for the onset of disease, and on days 15 and 34 they were weighed and had their blood harvested. Animals in G1 had the better overall ADG (0.613 Kg day-1 (P<0.05, with no clinical cases during the experiment. The performance in G2 was moderate, not differing from either G1 or G3 (mean ADG = 0.528 Kg day-1, however, this group had two clinical cases of anaplasmosis during the experiment. Animals in G3 had the worst performance, considering ADG (0.343 Kg day-1. When total weight gain per animal is compared for the study period (35 days, those in G1 gained an average of 20.851 Kg, followed by animals in G2 with 17.957 Kg, and then animals in G3 with 11.667 Kg. These results show that a low dose, agent specific (G1 drug protocol will considerably reduce the detrimental effects of subclinical tick borne diseases in the post weaning period and can be recommended as a rearing tool for calves destined for early slaughter.

  17. Prevalence of tick borne encephalitis virus in tick nymphs in relation to climatic factors on the southern coast of Norway

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    Andreassen Ashild

    2012-08-01

    Full Text Available Abstract Background Tick-borne encephalitis (TBE is among the most important vector borne diseases of humans in Europe and is currently identified as a major health problem in many countries. TBE endemic zones have expanded over the past two decades, as well as the number of reported cases within endemic areas. Multiple factors are ascribed for the increased incidence of TBE, including climatic change. The number of TBE cases has also increased in Norway over the past decade, and the human cases cluster along the southern coast of Norway. In Norway the distribution and prevalence of TBE virus (TBEV in tick populations is largely unknown. The objectives of this study were to estimate the TBEV prevalence in Ixodes ricinus from seven locations and to assess the relationship between the TBEV prevalence and site-specific climatic variables. Methods A total of 5630 questing nymphs were collected and analyzed in pools of ten. All pools were screened with an in-house real-time RT-PCR, and the positive pools were pyrosequenced. Two methods, minimum infection rate (MIR and a frequentist method (EPP for pooled prevalence estimations were calculated and compared. Climatic data were descriptively compared to the corresponding EPP of each location in order to explain variations in TBEV prevalence. Results The seven foci of TBEV had an estimated overall prevalence (EPP in pools of nymphs combined, of 0.53% with 95% CI (0.35–0.75, with point prevalence ranging between 0.11%–1.22%. The sites with the highest point prevalences were within the municipalities which had the highest numbers of registered TBE cases. The results indicate that the location with highest point prevalence had the highest relative mean humidity and lowest mean saturation deficit and vice versa for the lowest EPP. Conclusion Our study confirms the existence of TBEV endemic foci in Norway. These results are of importance to increase the awareness of TBEV infections in Norway and could be

  18. Prevention of infectious tick-borne diseases in humans: Comparative studies of the repellency of different dodecanoic acid-formulations against Ixodes ricinus ticks (Acari: Ixodidae

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    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

  19. Change in avian abundance predicted from regional forest inventory data

    Science.gov (United States)

    Twedt, Daniel J.; Tirpak, John M.; Jones-Farrand, D. Todd; Thompson, Frank R., III; Uihlein, William B.; Fitzgerald, Jane A.

    2010-01-01

    An inability to predict population response to future habitat projections is a shortcoming in bird conservation planning. We sought to predict avian response to projections of future forest conditions that were developed from nationwide forest surveys within the Forest Inventory and Analysis (FIA) program. To accomplish this, we evaluated the historical relationship between silvicolous bird populations and FIA-derived forest conditions within 25 ecoregions that comprise the southeastern United States. We aggregated forest area by forest ownership, forest type, and tree size-class categories in county-based ecoregions for 5 time periods spanning 1963-2008. We assessed the relationship of forest data with contemporaneous indices of abundance for 24 silvicolous bird species that were obtained from Breeding Bird Surveys. Relationships between bird abundance and forest inventory data for 18 species were deemed sufficient as predictive models. We used these empirically derived relationships between regional forest conditions and bird populations to predict relative changes in abundance of these species within ecoregions that are anticipated to coincide with projected changes in forest variables through 2040. Predicted abundances of these 18 species are expected to remain relatively stable in over a quarter (27%) of the ecoregions. However, change in forest area and redistribution of forest types will likely result in changed abundance of some species within many ecosystems. For example, abundances of 11 species, including pine warbler (Dendroica pinus), brown-headed nuthatch (Sitta pusilla), and chuckwills- widow (Caprimulgus carolinensis), are projected to increase within more ecoregions than ecoregions where they will decrease. For 6 other species, such as blue-winged warbler (Vermivora pinus), Carolina wren (Thryothorus ludovicianus), and indigo bunting (Passerina cyanea), we projected abundances will decrease within more ecoregions than ecoregions where they will

  20. Use of radio-immuno-assay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques to diagnose some tick-borne hemo-parasitic diseases

    International Nuclear Information System (INIS)

    Improved serology is essential for the diagnosis of tick-borne diseases in epidemiological studies. Sero-diagnosis of hemo-protozoan diseases is an important adjust to the use of vaccines for the control of these infections. These tests must meet a number of criteria, including sensitivity, specificity and the ability to detect long term infections. Enzyme linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) techniques were developed for the diagnosis of both Babesia bovis and B.bigemina antibodies. Whilst the RIA technique is more sensitive than the ELISA, the latter has the advantage of stability and relative safety of the detection system. Long term single infections can be diagnosed with these systems and they are ideal for detecting low levels of antibody. Further development of the B.bigemina ELISA is necessary, especially as the antigen is quite labile and must be freshly prepared. This is the one disadvantage in an otherwise highly sensitive and specific test system

  1. Ex-Ante Financial Analysis of Methods Applied for Integrated Control of Tick-Borne Diseases and Trypanosomosis in the Coastal Lowlands of Kenya

    International Nuclear Information System (INIS)

    A study was carried out in the coastal lowlands region of kilifi and Kwale districts to evaluate the financial impacts of two methods applied by smallholder farmers for concurrent control of ticks and tick-born diseases and trypanosomosis. the two strategies were application of synthetic pyrethroid pour-ons and rearing of cattle in netted zero-grazing units. the data was collected using rapid appraisals and cross-sectional surveys. A static simulation method was used to analyse the data. Both control strategies resulted in positive benefit cost ratios of approximately 1.5. It was concluded that these methods were economically viable and could be applied for integrated control of TBDs and trypanosomosis in areas where both are endemic

  2. [Interaction of the Siberian and Far Eastern subtypes of tick-borne encephalitis virus in mammals with mixed infection. Competition of the subtypes in acute and inapparent infection].

    Science.gov (United States)

    Gerasimov, S G; Pogodina, V V; Koliasnikova, N M; Karan', L S; Malenko, G V; Levina, L S

    2011-01-01

    Long-term monitoring of natural tick-borne encephalitis virus (TBEV) populations could reveal the change of TBEV subtypes, the displacement of the Far Eastern (FE) subtype, and its substitution for the Siberian (Sib) subtype. Acute and inapparent mixed infections were studied in Syrian hamsters to understand this phenomenon. The animals were inoculated with the Sib subtype and then with the FE one of TBEV (JQ845440-YaroslavI-Aver-08 and Fj214132-Kemerovo-Phateev-1954 strains). The inapparent form developed more frequently in mixed infection. Viral progeny was genotyped by reverse transcription polymerase chain reaction and hybridization fluorescence detection using genotype-specific probes. Independent reproduction of strains in the brain gave way to competition. The FE subtype dominated in hamster youngsters with acute infection. The Sib subtype had selective benefits in asymptomatic infection (adult hamsters infected intracerebrally and subcutaneously and youngsters infected subcutaneously). The competition of the subtypes was imperfect.

  3. Ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment.

    Science.gov (United States)

    Wikel, Stephen

    2013-01-01

    Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex sequence of carefully choreographed host defense responses and tick countermeasures resulting in an environment that facilitates successful blood feeding and establishment of tick-borne infectious agents within the host. Here, we examine diverse patterns of tick attachment to host skin, blood feeding mechanisms, salivary gland transcriptomes, bioactive molecules in tick saliva, timing of pathogen transmission, and host responses to tick bite. Ticks engage and modulate cutaneous and systemic immune defenses involving keratinocytes, natural killer cells, dendritic cells, T cell subpopulations (Th1, Th2, Th17, Treg), B cells, neutrophils, mast cells, basophils, endothelial cells, cytokines, chemokines, complement, and extracellular matrix. A framework is proposed that integrates tick induced changes of skin immune effectors with their ability to respond to tick-borne pathogens. Implications of these changes are addressed. What are the consequences of tick modulation of host cutaneous defenses? Does diversity of salivary gland transcriptomes determine differential modulation of host inflammation and immune defenses and therefore, in part, the clades of pathogens effectively transmitted by different tick species? Do ticks create an immunologically modified cutaneous environment that enhances specific pathogen establishment? Can tick saliva molecules be used to develop vaccines that block pathogen transmission? PMID:24312085

  4. Ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment

    Directory of Open Access Journals (Sweden)

    Stephen eWikel

    2013-11-01

    Full Text Available Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex sequence of carefully choreographed host defense responses and tick countermeasures resulting in an environment that facilitates successful blood feeding and establishment of tick-borne infectious agents within the host. Here, we examine diverse patterns of tick attachment to host skin, blood feeding mechanisms, salivary gland transcriptomes, bioactive molecules in tick saliva, timing of pathogen transmission, and host responses to tick bite. Ticks engage and modulate cutaneous and systemic immune defenses involving keratinocytes, natural killer cells, dendritic cells, T cell subpopulations (Th1, Th2, Th17, Treg , B cells, neutrophils, mast cells, basophils, endothelial cells, cytokines, chemokines, complement, and extracellular matrix. A framework is proposed that integrates tick induced changes of skin immune effectors with their ability to respond to tick-borne pathogens. Implications of these changes are addressed. What are the consequences of tick modulation of host cutaneous defenses? Does diversity of salivary gland transcriptomes determine differential modulation of host inflammation and immune defenses and therefore, in part, the clades of pathogens effectively transmitted by different tick species? Do ticks create an immunologically modified cutaneous environment that enhances specific pathogen establishment? Can tick saliva molecules be used to develop vaccines that block pathogen transmission?

  5. Characterization of the Bhanja Serogroup Viruses (Bunyaviridae): a Novel Species of the Genus Phlebovirus and Its Relationship with Other Emerging Tick-Borne Phleboviruses

    Science.gov (United States)

    Matsuno, Keita; Weisend, Carla; Travassos da Rosa, Amelia P. A.; Anzick, Sarah L.; Dahlstrom, Eric; Porcella, Stephen F.; Dorward, David W.; Yu, Xue-Jie; Tesh, Robert B.

    2013-01-01

    Bhanja virus (BHAV) and its antigenically close relatives Forecariah virus (FORV), Kismayo virus (KISV), and Palma virus (PALV) are thought to be members of the family Bunyaviridae, but they have not been assigned to a genus or species. Despite their broad geographical distribution and reports that BHAV causes sporadic cases of febrile illness and encephalitis in humans, the public health importance of the Bhanja serogroup viruses remains unclear, due in part to the lack of sequence and biochemical information for the virus proteins. In order to better define the molecular characteristics of this group, we determined the full-length sequences of the L, M, and S genome segments of multiple isolates of BHAV as well as FORV and PALV. The genome structures of these Bhanja viruses are similar to those of viruses belonging to the genus Phlebovirus. Functional domains and amino acid motifs in the viral proteins that are conserved among other known phleboviruses were also identified in proteins of the BHAV group. Phylogenetic and serological analyses revealed that the BHAVs are most closely related to the novel emerging tick-borne phleboviruses severe fever with thrombocytopenia syndrome virus and Heartland virus, which have recently been implicated as causing severe acute febrile illnesses associated with thrombocytopenia in humans in China and the United States. Our results indicate that the Bhanja serogroup viruses constitute a single novel species in the genus Phlebovirus. The results of this study should facilitate epidemiological surveillance for other, similar tick-borne phleboviruses that may represent unrecognized causes of febrile illness in humans. PMID:23325688

  6. Sixty years of research of tick-borne encephalitis--a basis of the current knowledge of the epidemiological situation in Central Europe.

    Science.gov (United States)

    Daniel, M; Benes, C; Danielová, V; Kríz, B

    2011-11-01

    Tick-borne encephalitis (TBE) virus was isolated for the first time in Central Europe in 1948 from both a patient and Ixodes ricinus ticks collected in the area where the patient had been tick bitten (the Beroun area - Central Bohemia) and concomitantly from a TBE patient in Moravia (the Vyskov area). Another priority discovery was alimentary transmission of TBE virus via the milk from tick infected grazing goats that was made during a TBE outbreak in Roznava (SE Slovakia). This outbreak of 660 cases has been the largest of its kind. Both of these discoveries were a challenge to multidisciplinary research into the natural focality of TBE. The results obtained were published by Czech and Slovak authors in the first European TBE monograph (1954) and were the stimulus for further research in this area. From the epidemiological point of view, among others, the impact of meteorological factors (on TBE incidence associated with I. ricinus host-seeking activity) and recreational nature of TBE were clearly defined then. At the same time, TBE became a notifiable disease (since 1971 laboratory confirmed TBE cases only). In the following decades, the phenomenon of natural focality of TBE (including anthropic impacts) was extensively studied and the determinants of high-risk areas in the field were analyzed. The results were used in the creation of I. ricinus and TBE risk prediction maps for the Czech Republic generated for the first time in Europe using LANDSAT 5 satellite data and GIS technology (1990). In the early 1990s (in particular since 1993), similarly to other countries, the Czech Republic reported a sharp rise in TBE cases that continues, with some fluctuations, until now. The cooperation with climatologists in the analysis of historical data, current epidemiological observations, and study of I. ricinus in the field have shown a decisive impact of the ongoing climate change. The analysis of the socio-economic conditions in high-risk areas for TBE has not revealed

  7. A serological survey of tick-borne pathogens in dogs in North America and the Caribbean as assessed by Anaplasma phagocytophilum, A. platys, Ehrlichia canis, E. chaffeensis, E. ewingii, and Borrelia burgdorferi species-specific peptides

    Directory of Open Access Journals (Sweden)

    Barbara A. Qurollo

    2014-10-01

    Full Text Available Introduction: Tick-borne pathogens cause a spectrum of disease manifestations in both dogs and humans. Recognizing regional and temporal shifts in exposure are important as tick distributions change. To better delineate regional exposure to canine tick-borne pathogens, an expanded set of species-specific peptides were used to detect Anaplasma phagocytophilum (Aph, Anaplasma platys (Apl, Ehrlichia canis (Ec, Ehrlichia chaffeensis (Ech, Ehrlichia ewingii (Eew, and Borrelia burgdorferi (Bb antibodies in canine serum. Methods: Archived canine serum samples (n=6,582 collected during 2008–2010 and in 2012 from the US, Canada, and the Caribbean were retrospectively screened for antibodies against Ehrlichia and Anaplasma species-specific peptides. Overall, regional and temporal seroprevalence rates were determined. Results: Overall Bb and Eew were the most seroprevalent pathogens. During 2008–2010, seroprevalence rates increased overall for Aph and Ech, and regionally, Bb and Aph seroprevalence rates increased in the South. Canada had unexpectedly high seroprevalence rates for Ec and Apl. The most common co-exposures were Eew+Ech, followed by Aph+Bb and Eew+Bb. Conclusions: This study demonstrated significant shifts in canine vector-borne disease seroprevalence rates. The use of specific peptides facilitated improved geographic delineation of tick-borne pathogen distributions among dogs, which may enhance epidemiological surveillance of vector-borne pathogens shared by dogs and humans.

  8. Tigers and their prey: Predicting carnivore densities from prey abundance

    Science.gov (United States)

    Karanth, K.U.; Nichols, J.D.; Kumar, N.S.; Link, W.A.; Hines, J.E.

    2004-01-01

    The goal of ecology is to understand interactions that determine the distribution and abundance of organisms. In principle, ecologists should be able to identify a small number of limiting resources for a species of interest, estimate densities of these resources at different locations across the landscape, and then use these estimates to predict the density of the focal species at these locations. In practice, however, development of functional relationships between abundances of species and their resources has proven extremely difficult, and examples of such predictive ability are very rare. Ecological studies of prey requirements of tigers Panthera tigris led us to develop a simple mechanistic model for predicting tiger density as a function of prey density. We tested our model using data from a landscape-scale long-term (1995-2003) field study that estimated tiger and prey densities in 11 ecologically diverse sites across India. We used field techniques and analytical methods that specifically addressed sampling and detectability, two issues that frequently present problems in macroecological studies of animal populations. Estimated densities of ungulate prey ranged between 5.3 and 63.8 animals per km2. Estimated tiger densities (3.2-16.8 tigers per 100 km2) were reasonably consistent with model predictions. The results provide evidence of a functional relationship between abundances of large carnivores and their prey under a wide range of ecological conditions. In addition to generating important insights into carnivore ecology and conservation, the study provides a potentially useful model for the rigorous conduct of macroecological science.

  9. The nature of replication of tick-borne encephalitis virus strains isolated from residents of the Russian Far East with inapparent and clinical forms of infection.

    Science.gov (United States)

    Leonova, Galina N; Maystrovskaya, Olga S; Kondratov, Ilya G; Takashima, Ikuo; Belikov, Sergei I

    2014-08-30

    We describe the biological properties and molecular characteristics of complete genomes of 33 tick-borne encephalitis virus (TBEV) strains that induced different forms of infection, from inapparent to severe focal ones resulting in fatal outcome. Hemagglutinating activity of Oshima-like strains was higher at pH 5.8, while activity of Sofjin- and Senhzang-like strains were higher at pH 6.2 and 6.8, respectively. We determined susceptibility of porcine kidney (PK) cell cultures to these TBEV strains by cytopathic effect (CPE), plaque formation, and size of plaques. The clinical TBEV strains had higher virus titers both in tissue culture infectious dose 50(TCID50) and in plaque-forming unit (PFU) titers and larger plaques than the inapparent strains. A comparison of virus multiplication kinetics by PFU in culture fluid with kinetics of ELISA antigen and hemagglutinin accumulation suggested a different mechanism of interaction between these virus strains and PK cells at the initial stage of cell infection.

  10. Serological evidence of exposure to tick-borne agents in opossums (Didelphis spp. in the state of São Paulo, Brazil

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    Andréia Lima Tomé Melo

    2016-01-01

    Full Text Available Abstract This work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of São Paulo, Brazil. Serum samples from 109 opossums (91 Didelphis aurita and 18 Didelphis albiventris were tested to detect antibodies to Rickettsia rickettsii (Taiaçu strain, 1:64 cut-off and Ehrlichia canis (São Paulo strain, 1:40 cut-off, by indirect immunofluorescence assay (IFA; and against Borrelia burgdorferi (strain G39/40 by enzyme-linked immunosorbent assay (ELISA. The presence of antibodies to anti-R. rickettsii, anti-E. canis and anti-B. burgdorferi was detected in 32 (29.35%, 16 (14.67% and 30 (27.52% opossums, respectively. Opossum endpoint titers ranged from 64 to 1,024 for R. rickettsii, from 40 to 160 for E. canis, and from 400 to >51,200 for B. burgdorferi. These serological results suggest that opossums have been exposed to Rickettsia spp., Ehrlichia spp., and B. burgdorferi-related agents in the state of São Paulo. Our study underscores the need for further research about these agents in this study area, in view of the occurrence of Spotted Fever and Baggio-Yoshinari Syndrome disease in humans in the state of São Paulo, Brazil.

  11. Serological evidence of exposure to tick-borne agents in opossums (Didelphis spp.) in the state of São Paulo, Brazil.

    Science.gov (United States)

    Melo, Andréia Lima Tomé; Aguiar, Daniel Moura de; Spolidorio, Mariana Granziera; Yoshinari, Natalino Hajime; Matushima, Eliana Reiko; Labruna, Marcelo Bahia; Horta, Mauricio Claudio

    2016-06-01

    This work involved a serological investigation of tick-borne pathogens in opossums in eight municipalities of the state of São Paulo, Brazil. Serum samples from 109 opossums (91 Didelphis aurita and 18 Didelphis albiventris) were tested to detect antibodies to Rickettsia rickettsii (Taiaçu strain, 1:64 cut-off) and Ehrlichia canis (São Paulo strain, 1:40 cut-off), by indirect immunofluorescence assay (IFA); and against Borrelia burgdorferi (strain G39/40) by enzyme-linked immunosorbent assay (ELISA). The presence of antibodies to anti-R. rickettsii, anti-E. canis and anti-B. burgdorferi was detected in 32 (29.35%), 16 (14.67%) and 30 (27.52%) opossums, respectively. Opossum endpoint titers ranged from 64 to 1,024 for R. rickettsii, from 40 to 160 for E. canis, and from 400 to >51,200 for B. burgdorferi. These serological results suggest that opossums have been exposed to Rickettsia spp., Ehrlichia spp., and B. burgdorferi-related agents in the state of São Paulo. Our study underscores the need for further research about these agents in this study area, in view of the occurrence of Spotted Fever and Baggio-Yoshinari Syndrome disease in humans in the state of São Paulo, Brazil. PMID:27276663

  12. Protective role of TNF-α, IL-10 and IL-2 in mice infected with the Oshima strain of Tick-borne encephalitis virus

    Science.gov (United States)

    Tun, Mya Myat Ngwe; Aoki, Kotaro; Senba, Masachika; Buerano, Corazon C.; Shirai, Kenji; Suzuki, Ryuji; Morita, Kouichi; Hayasaka, Daisuke

    2014-01-01

    Tick-borne encephalitis virus (TBEV) causes acute central nervous system disease. Here, we investigated the roles of the TNF-α, IL-10 and other cytokines in appropriate KO mice following infection with Oshima and Sofjin strains of TBEV. Following infection with the Oshima strain, mortality rates were significantly increased in TNF-α KO and IL-10 KO mice compared with wild type (WT) mice. These results suggested that TNF-α and IL-10 play protective roles against fatal infection due to Oshima strain infection. However, viral loads and proinflammatory cytokine levels in the brain of TNF-α KO andIL-10 KO mice were not significantly different compared with those of WT mice. On the other hand, all WT, TNF-α KO and IL-10 KO mice died following infection with Sofjin strain. Interestingly, Sofjin-infected mice did not exhibit an up-regulated mRNA level of IL-2 in the spleen in all groups of mice, whereas Oshima-infected mice showed significantly increased level of IL-2 compared with mock-infected mice. From these results, we suggest that TNF-α, IL-10 and IL-2 are key factors for disease remission from fatal encephalitis due to infection with Oshima strain of TBEV. PMID:24938868

  13. Survey of canine tick-borne diseases in Lábrea, Brazilian Amazon: ‘accidental’ findings of Dirofilaria immitis infection

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    Herbert Sousa Soares

    2014-12-01

    Full Text Available Blood samples were collected from 99 domestic dogs from the urban and rural areas of the Lábrea municipality, state of Amazonas, Brazil. Canine serum samples were tested by immunofluorescence assay against Rickettsia spp., which revealed that only 3.0% (1/33 and 7.6% (5/66 of the dogs from urban and rural areas, respectively, reacted positively to at least one Rickettsia species. DNA was extracted from canine blood and tested by a battery of PCR assays targeting protozoa of the genera Babesia and Hepatozoon, and bacteria of the genera Rickettsia and Ehrlichia and family Anaplasmataceae. All samples were negative in the PCR assays targeting the genera Babesia, Hepatozoon, Ehrlichia and Rickettsia. For Anaplasmataceae, 3% (1/33 and 39.4% (26/66 of the urban and rural dogs, respectively, yielded amplicons that generated DNA sequences 100% identical to the corresponding sequence of Wolbachia endosymbiont of Dirofilaria immitis. Because of these results, all canine DNA samples were further tested in a PCR assay targeting filarial nematodes, which was positive for 18.2% (6/33 and 57.6% (38/66 urban and rural dogs, respectively. Filarial-PCR products generated DNA sequences 100% identical to D. immitis. While tick-borne infections were rare in Lábrea, D. immitis infection rates were among the highest reported in South America.

  14. 甘肃省武威市蜱及蜱媒病种类及分布的初步调查%Investigation on Species and Distribution of Ticks and Tick-borne Diseases in Wuwei City,Gansu Province

    Institute of Scientific and Technical Information of China (English)

    孙明; 王淑芳; 王多全; 杨永彪; 马超

    2016-01-01

    [目的]了解甘肃省武威市蜱和蜱媒病的种类和分布情况,便于建立牛、羊等草食家畜疫病的科学防控模式。[方法]通过布旗法、家畜体表捕捉法与分子生物学方法,对武威市所辖的4个县(区)进行了蜱传播疫病及其传播媒介的流行病学调查。[结果]在全市41个乡镇均发现有蜱的存在,主要以硬蜱属为主,但也发现有软蜱属;全市各县区均发现有梨形虫的感染。[结论]蜱在武威市分布广泛,该地区的蜱媒病感染情况也比较严重;软蜱属的发现增大了外来动物疫病的感染风险;威武地区需加强对蜱及蜱媒病危害和防控的认识,采取以灭蜱和杀灭病畜体内病原相结合的方法,来控制虫媒病的传播。%s:[Objective] To understand the tick species and tick-borne diseases, as to establish animal disease prevention and control model for herbivores such as cattle and sheep in Wuwei city.[Methods] Epidemiological investigation for tick-borne diseases and the vectors was conducted by methods of cloth flag, capture surface ticks of livestock body, and molecular biology in 41 counties within Wuwei city.[Results] the investigation showed that there were dominant hard ticks and some soft ticks distribution, and infestation of Piroplasmosis in all 41 counties of Wuwei City.[Conclusion] Ticks were widely distributed and infestations of tick-borne diseases were serious; the existed ticks increased the risk of infection of exotic animal diseases; the awareness of the risks and control of ticks and tick-borne diseases should be raised, and the spread of the tick-borne diseases should be controlled by combination of killing ticks and inactivating pathogens within infected animals.

  15. Molecular epidemiological surveillance to assess emergence and re-emergence of tick-borne infections in tick samples from China evaluated by nested PCRs.

    Science.gov (United States)

    Yu, Pei-Fa; Niu, Qing-Li; Liu, Zhi-Jie; Yang, Ji-Fei; Chen, Ze; Guan, Gui-Quan; Liu, Guang-Yuan; Luo, Jian-Xun; Yin, Hong

    2016-06-01

    An investigation was performed to detect eight pathogens in ticks collected from grass tips or animals in the southern, central and northeast regions of China. DNA samples extracted from ticks were collected from ten different locations in eight provinces of China and subjected to screening for tick-borne pathogens, including Borrelia burgdorferi sensu lato, Ehrlichia spp., Rickettsia spp., Babesia/Theileria spp., Ehrlichia ruminantium, Coxiella burnetii, and Francisella tularensis, using nested PCR assays and sequencing analysis. The results indicated that Borrelia spp., Rickettsia spp., and Babesia/Theileria spp. were detected in all of the investigated provinces. Ehrlichia spp. was also found in all of the surveyed areas, except Guangxi, Luobei and Tonghe counties in Heilongjiang province. The average prevalence of these pathogens was 18.4% (95% CI=12.8-42.5), 60.3% (95% CI=18.2-65.3), 26.0% (95% CI=25.8-65.1), and 28.7% (95% CI=5.6-35.2), respectively. A sequencing analysis of the pCS20 gene of E. ruminantium revealed an E. ruminantium-like organism (1/849, 0.1%, 95% CI=0-0.3) in one tick DNA sample extracted from Rhipicephalus (Boophilus) microplus in Hunan. In addition, Borrelia americana in Ixodes persulcatus, Babesia occultans in Haemaphysalis qinghaiensis and both Rhipicephalus sanguineus and an Ehrlichia muris-like organism in R. (B.) microplus was detected, possibly for the first time in China. Four DNA sequences closely related to Borrelia carolinensis and/or Borrelia bissettii from Haemaphysalis longicornis, Candidatus Rickettsia principis from H. qinghaiensis, and I. persulcatus and Ehrlichia canis (named E. canis-like) from Haemaphysalis bispinosa were also detected in this work. PMID:26943995

  16. Are patients with erythema migrans who have leukopenia and/or thrombocytopenia coinfected with Anaplasma phagocytophilum or tick-borne encephalitis virus?

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    Franc Strle

    Full Text Available Lyme borreliosis (LB, tick-borne encephalitis (TBE and human granulocytic anaplasmosis (HGA are endemic in central part of Slovenia. We tested the hypothesis that patients with erythema migrans (EM from this region, who have leukopenia and/or thrombocytopenia (typical findings in HGA and in the initial phase of TBE but not in patients with LB are coinfected with Anaplasma phagocytophilum and/or with TBE virus, i.e. that cytopenia is a result of concomitant HGA or the initial phase of TBE. Comparison of clinical and laboratory findings for 67 patients with EM who disclosed leukopenia/thrombocytopenia with the corresponding results in sex- and age-matched patients with EM and normal blood cell counts revealed no differences. In addition, patients with typical EM and leukopenia and/or thrombocytopenia tested negative for the presence of IgM and IgG antibodies to TBE virus by ELISA as well as for the presence of specific IgG antibodies to A. phagocytophilum antigens by IFA in acute and convalescent serum samples. Thus, none of 67 patients (95% CI: 0 to 5.3% with typical EM (the presence of this skin lesion attests for early Lyme borreliosis and is the evidence for a recent tick bite was found to be coinfected with A. phagocytophilum or had a recent primary infection with TBE virus. The findings in the present study indicate that in Slovenia, and probably in other European countries endemic for LB, TBE and HGA, patients with early LB are rarely coinfected with the other tick-transmitted agents.

  17. The role of game (wild boar and roe deer) in the spread of tick-borne encephalitis in the Czech Republic.

    Science.gov (United States)

    Kriz, Bohumir; Daniel, Milan; Benes, Cestmir; Maly, Marek

    2014-11-01

    In the Czech Republic, the incidence of human tick-borne encephalitis (TBE) has been increasing over the last two decades. At the same time, populations of game have also shown an upward trend. In this country, the ungulate game is the main host group of hosts for Ixodes ricinus female ticks. This study examined the potential contribution of two most widespread game species (roe deer [Capreolus capreolus] and wild boar [Sus scrofa]) to the high incidence of TBE in the Czech Republic, using the annual numbers of culls as a proxy for the game population. This was an ecological study, with annual figures for geographical areas-municipalities with extended competence (MEC)-used as units of analysis. Between 2003 and 2011, a total of 6213 TBE cases were reported, and 1062,308 roe deer and 989,222 wild boars were culled; the culls of roe deer did not demonstrate a clear temporal trend, but wild boar culls almost doubled (from 77,269 to 143,378 per year). Statistical analyses revealed a positive association between TBE incidence rate and the relative number of culled wild boars. In multivariate analyses, a change in the numbers of culled wild boars between the 25th and 75th percentile was associated with TBE incidence rate ratio of 1.23 (95% confidence interval 1.07-1.41, p=0.003). By contrast, the association of TBE with culled roe deer was not statistically significant (p=0.481). The results suggest that the size of the wild boar population may have contributed to the current high levels and the rising trend in incidence of TBE, whereas the regulated population of roe deer does not seem to be implicated in recent geographical or temporal variations in TBE in the Czech Republic.

  18. Risks of suffering tick-borne diseases in sheep translocated to a tick infested area: a laboratory approach for the investigation of an outbreak.

    Science.gov (United States)

    Hurtado, Ana; Barandika, Jesús F; Oporto, Beatriz; Minguijón, Esmeralda; Povedano, Inés; García-Pérez, Ana L

    2015-02-01

    This study was designed to investigate an outbreak of high mortality that occurred in naïve Assaf sheep introduced into a Latxa sheep flock in the Basque Country, a region where piroplasmosis is endemic. To identify the causes of this outbreak, a panel of different methods, including traditional pathological, biopathological and parasitological analyses combined with recently developed molecular methods, was used. These novel molecular methods included a multiplex real-time PCR assay to screen for the presence of the most important tick-borne pathogens (piroplasms and anaplasmas), followed by a second species-specific multiplex real-time PCR assay for the identification of Anaplasma-positive samples. The identification of piroplasm-positive samples was carried out by a multiplexed microsphere-based suspension array using a Luminex(®) xMAP technology-based procedure. Anaplasmas and/or piroplasms were detected in 7/10 lambs and 11/13 ewes, with Babesia ovis being detected in 12 of the 23 animals, Theileria ovis in 6 and Anaplasma ovis in 4, both as single and mixed infections. Most of the animals infected with B. ovis had a marked decrease in the values of the red blood cell parameters. Ticks collected from the animals were identified as Riphicephalus bursa, recognised vector of B. ovis. Other haemolytic pathologies (clostridial disease, copper poisoning and leptospirosis) were ruled out and, considering all clinical, laboratory and epidemiological data, babesiosis by B. ovis was diagnosed. A detailed description of the clinical outcome, with ca. 60% of mortality, laboratory results and epidemiological findings are provided. The implications of the introduction of naïve animals into a piroplasmosis endemic area are discussed. PMID:25257849

  19. Prediction of abundance of beetles according to climate warming in South Korea

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    Tae-Sung Kwon

    2015-03-01

    Full Text Available To identify the change in distribution of insects in climate warming, changes in abundance of beetles were predicted using data from 366 survey sites (forests in South Korea. Abundance along temperature gradients showed patterns (linear or hump-shaped of normal distribution for 18 candidate species. Mean abundance in temperature zones of these species was used to predict the change in abundance. Temperature change was based on climate scenario Representative Concentration Pathways (RCP 4.5 and 8.5 and abundance of the two periods from 2011 to 2015 and 2056 to 2065 were predicted. Of the 18 species analyzed, six were predicted to increase in abundance and 12 were predicted to decrease. Using a high relationship between abundance change and temperature of collected sites, a qualitative prediction was conducted on non-candidate species with ≥ 1% occurrence. This prediction also shows that more beetle species in South Korea will decrease rather than increase as climate warms.

  20. Predicted CALET Measurements of Ultra-Heavy Cosmic Ray Abundances

    Science.gov (United States)

    Rauch, Brian

    2013-04-01

    The CALorimetric Electron Telescope (CALET), comprised of main calorimeter telescope (CAL) and Gamma-ray Burst Monitor (CGBM), is under construction for launch to the ISS in 2014. CAL consists of a Charge Detector (CHD) with two segmented planes of 1 cm thick plastic scintillator, an Imaging Calorimeter (IMC) with a total of 3 radiation lengths (X0) of tungsten plates read out with 8 planes of interleaved scintillating fibers, and a Total Absorption Calorimeter (TASC) with 27 X0 of lead tungstate (PWO) logs. The primary objectives of CAL are to measure electron energy spectra from 1GeV to 20 TeV, to detect gamma-rays above 10 GeV, and to measure the energy spectra of nuclei from protons through iron up to 1,000 TeV. In this paper we discuss the predicted abundance measurements CAL can make of rare ultra-heavy (UH) nuclei (30 IMC layers without requiring particle energy determination in the TASC in the portion of the ISS 51.6^o inclination orbit where the geomagnetic rigidity cutoffs are above minimum ionization in the scintillator. In 5-years CAL would collect 4-5 times the UH statistics of TIGER.

  1. Using participatory epidemiology to investigate management options and relative importance of tick-borne diseases amongst transhumant zebu cattle in Karamoja Region, Uganda.

    Science.gov (United States)

    Byaruhanga, C; Oosthuizen, M C; Collins, N E; Knobel, D

    2015-12-01

    A participatory epidemiological (PE) study was conducted with livestock keepers in Moroto and Kotido districts, Karamoja Region, Uganda, between October and December 2013 to determine the management options and relative importance of tick-borne diseases (TBDs) amongst transhumant zebu cattle. Data collection involved 24 focus group discussions (each comprising 8-12 people) in 24 settlement areas (manyattas), key informant interviews (30), direct observation, a review of surveillance data, clinical examination, and laboratory confirmation of cases of TBDs. Methods used in group discussions included semi-structured interviews, simple ranking, pairwise ranking, matrix scoring, proportional piling and participatory mapping. The results of pairwise comparison showed the Ngakarimojong-named diseases, lokit (East Coast fever, ECF), lopid (anaplasmosis), loukoi (contagious bovine pleuropneumonia, CBPP), lokou (heartwater) and lokulam (babesiosis), were considered the most important cattle diseases in Moroto in that order, while ECF, anaplasmosis, trypanosomosis (ediit), CBPP and nonspecific diarrhoea (loleo) were most important in Kotido. Strong agreement between informant groups (Kendall's coefficient of concordance W=0.568 and 0.682; p<0.001) in pairwise ranking indicated that the diseases were a common problem in selected districts. East Coast fever had the highest median score for incidence (18% [range: 2, 33]) in Moroto, followed by anaplasmosis (17.5% [8,32]) and CBPP (9% [1,21]). Most animals that suffered from ECF, anaplasmosis, heartwater and babesiosis died, as the respective median scores for case fatality rates (CFR) were 89.5% (42, 100), 82.8% (63, 100), 66.7% (20, 100) and 85.7% (0, 100). In Kotido, diseases with high incidence scores were ECF (21% [6,32]), anaplasmosis (17% [10,33]) and trypanosomosis (8% [2,18]). The CFRs for ECF and anaplasmosis were 81.7% (44, 100) and 70.7% (48, 100), respectively. Matrix scoring revealed that disease indicators showed

  2. Prediction of abundance of beetles according to climate warming in South Korea

    OpenAIRE

    Tae-Sung Kwon; Cheol Min Lee; Sung-Soo Kim

    2015-01-01

    To identify the change in distribution of insects in climate warming, changes in abundance of beetles were predicted using data from 366 survey sites (forests) in South Korea. Abundance along temperature gradients showed patterns (linear or hump-shaped) of normal distribution for 18 candidate species. Mean abundance in temperature zones of these species was used to predict the change in abundance. Temperature change was based on climate scenario Representative Concentration Pathways (RCP) 4.5...

  3. Predicting changes in the distribution and abundance of species under environmental change

    OpenAIRE

    Ehrlén, Johan; Morris, William F.

    2015-01-01

    Environmental changes are expected to alter both the distribution and the abundance of organisms. A disproportionate amount of past work has focused on distribution only, either documenting historical range shifts or predicting future occurrence patterns. However, simultaneous predictions of abundance and distribution across landscapes would be far more useful. To critically assess which approaches represent advances towards the goal of joint predictions of abundance and distribution, we revi...

  4. Prediction of abundance of forest spiders according to climate warming in South Korea

    OpenAIRE

    Tae-Sung Kwon; Cheol Min Lee; Tae Woo Kim; Sung-Soo Kim; Joo Han Sung

    2014-01-01

    Distribution of spiders will be changed as climate warms. Abundance of spider species was predicted nationwide in South Korea. Abundance of spiders was projected using temperature species distribution model based on a nationwide data (366 forest sites) according to climate change scenario RCP 4.5 and 8.5. The model predicts that 9 out of 17 species will increase in abundance while 8 species will decrease. Based on this finding, a qualitative prediction (increase or decrease) was conducted on ...

  5. Prediction of abundance of ants due to climate warming in South Korea

    OpenAIRE

    Tae-Sung Kwon; Cheol Min Lee; Juhan Park; Sung-Soo Kim; Jung Hwa Chun; Joo Han Sung

    2014-01-01

    Among the 57 species of ants collected from 366 forest sites, 16 candidate species whose abundance has a close relation with temperature were selected to predict the changes in distribution and abundance according to the A1B climate change scenario. The results showed that, when the temperature rises, the abundance of 11 species is expected to decrease, whereas five species are expected to increase. Based on the qualitative estimation, the abundance of 10 species among the 31 species is predi...

  6. Interim Report on SNP analysis and forensic microarray probe design for South American hemorrhagic fever viruses, tick-borne encephalitis virus, henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever viruses, Rift Valley fever

    Energy Technology Data Exchange (ETDEWEB)

    Jaing, C; Gardner, S

    2012-06-05

    The goal of this project is to develop forensic genotyping assays for select agent viruses, enhancing the current capabilities for the viral bioforensics and law enforcement community. We used a multipronged approach combining bioinformatics analysis, PCR-enriched samples, microarrays and TaqMan assays to develop high resolution and cost effective genotyping methods for strain level forensic discrimination of viruses. We have leveraged substantial experience and efficiency gained through year 1 on software development, SNP discovery, TaqMan signature design and phylogenetic signature mapping to scale up the development of forensics signatures in year 2. In this report, we have summarized the whole genome wide SNP analysis and microarray probe design for forensics characterization of South American hemorrhagic fever viruses, tick-borne encephalitis viruses and henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus and Japanese encephalitis virus.

  7. Prediction of abundance of ants due to climate warming in South Korea

    Directory of Open Access Journals (Sweden)

    Tae-Sung Kwon

    2014-06-01

    Full Text Available Among the 57 species of ants collected from 366 forest sites, 16 candidate species whose abundance has a close relation with temperature were selected to predict the changes in distribution and abundance according to the A1B climate change scenario. The results showed that, when the temperature rises, the abundance of 11 species is expected to decrease, whereas five species are expected to increase. Based on the qualitative estimation, the abundance of 10 species among the 31 species is predicted to increase, whereas that of 21 species is projected to decrease. The abundance of 32 species among 57 species was expected to decrease due to climate changes, whereas 15 species was expected to increase; the number of species expected to decrease was more than two times that of species that are expected to increase.

  8. Abundance distributions over the surfaces of magnetic ApBp stars: theoretical predictions

    CERN Document Server

    Alecian, G

    2015-01-01

    Recently published empirical abundance maps, obtained through (Zeeman) Doppler mapping (ZDM), do not currently agree with the abundance structures predicted by means of numerical models of atomic diffusion in magnetic atmospheres of ApBp stars. In a first step towards the resolution of these discrepancies, we present a state of the art grid of equilibrium abundance stratifications in the atmosphere of a magnetic Ap star with T_eff = 10000 K and log g = 4.0. A description of the behaviour of 16 chemical elements including predictions concerning the over- and/or under-abundances over the stellar surface is followed by a discussion of the possible influence of presently neglected physical processes.

  9. Prediction of abundance of forest spiders according to climate warming in South Korea

    Directory of Open Access Journals (Sweden)

    Tae-Sung Kwon

    2014-06-01

    Full Text Available Distribution of spiders will be changed as climate warms. Abundance of spider species was predicted nationwide in South Korea. Abundance of spiders was projected using temperature species distribution model based on a nationwide data (366 forest sites according to climate change scenario RCP 4.5 and 8.5. The model predicts that 9 out of 17 species will increase in abundance while 8 species will decrease. Based on this finding, a qualitative prediction (increase or decrease was conducted on the species with more than 1% occurrence: 68 species are expected to decrease, 9 to increase, and 8 to change a little. In pooled estimation, 76 species (75% are expected to decrease, 18 species (18% to increase, and by 8 species (8% to have little change. The projection indicates that majority of spider species will decrease, but minority of species will increase as climate warms, suggesting great increase of remained species in lowlands.

  10. Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates

    Science.gov (United States)

    Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn

    2016-01-01

    Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.

  11. The neurovirulence and neuroinvasiveness of chimeric tick-borne encephalitis/dengue virus can be attenuated by introducing defined mutations into the envelope and NS5 protein genes and the 3' non-coding region of the genome

    International Nuclear Information System (INIS)

    Tick-borne encephalitis (TBE) is a severe disease affecting thousands of people throughout Eurasia. Despite the use of formalin-inactivated vaccines in endemic areas, an increasing incidence of TBE emphasizes the need for an alternative vaccine that will induce a more durable immunity against TBE virus (TBEV). The chimeric attenuated virus vaccine candidate containing the structural protein genes of TBEV on a dengue virus genetic background (TBEV/DEN4) retains a high level of neurovirulence in both mice and monkeys. Therefore, attenuating mutations were introduced into the envelope (E315) and NS5 (NS5654,655) proteins, and into the 3' non-coding region (Δ30) of TBEV/DEN4. The variant that contained all three mutations (vΔ30/E315/NS5654,655) was significantly attenuated for neuroinvasiveness and neurovirulence and displayed a reduced level of replication and virus-induced histopathology in the brains of mice. The high level of safety in the central nervous system indicates that vΔ30/E315/NS5654,655 should be further evaluated as a TBEV vaccine.

  12. Combined prime-boost vaccination against tick-borne encephalitis (TBE using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

    Directory of Open Access Journals (Sweden)

    Zakharova LG

    2005-08-01

    Full Text Available Abstract Background Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol. Results The heterologous prime-boost vaccination protocol, using a VV recombinant and bacterial plasmid, both containing the NS1 TBE virus protein gene under the control of different promoters, achieved a high level of protection in mice against lethal challenge with a highly pathogenic TBE virus strain. No signs of pronounced TBE infection were detected in the surviving animals. Conclusion Heterologous prime-boost vaccination protocols using recombinant VV and bacterial plasmids could be used for the development of flavivirus vaccines.

  13. Non-explosive hydrogen and helium burnings: abundance predictions from the NACRE reaction rate compilation

    Science.gov (United States)

    Arnould, M.; Goriely, S.; Jorissen, A.

    1999-07-01

    The abundances of the isotopes of the elements from C to Al produced by the non-explosive CNO, NeNa and MgAl modes of hydrogen burning, as well as by helium burning, are calculated with the thermonuclear rates recommended by the European compilation of reaction rates for astrophysics (NACRE). The impact of nuclear physics uncertainties on the derived abundances is discussed in the framework of a simple parametric astrophysical model. These calculations have the virtue of being a guide in the selection of the nuclear uncertainties that have to be duly analyzed in detailed model stars, particularly in order to perform meaningful confrontations between abundance observations and predictions. They are also hoped to help nuclear astrophysicists pinpointing the rate uncertainties that have to be reduced most urgently. An electronic version of this paper, with colour figures, is available at {\\it http://astro.ulb.ac.be}

  14. Serosurvey for tick-borne diseases in dogs from the Eastern Amazon, Brazil Pesquisa Sorológica por doenças transmitidas por carrapatos em cães da Amazônia oriental, Brasil

    Directory of Open Access Journals (Sweden)

    Mariana Granziera Spolidorio

    Full Text Available Canine ehrlichiosis and babesiosis are the most prevalent tick-borne diseases in Brazilian dogs. Few studies have focused attention in surveying tick-borne diseases in the Brazilian Amazon region. A total of 129 blood samples were collected from dogs living in the Brazilian eastern Amazon. Seventy-two samples from dogs from rural areas of 19 municipalities and 57 samples from urban stray dogs from Santarém municipality were collected. Serum samples were submitted to Indirect Immunofluorescence Assay (IFA with antigens of Babesia canis vogeli, Ehrlichia canis, and six Rickettsia species. The frequency of dogs containing anti-B. canis vogeli, anti-E. canis, and anti-Rickettsia spp. antibodies was 42.6%, 16.2%, and 31.7%, respectively. Anti-B. canis vogeli antibodies were detected in 59.6% of the urban dogs, and in 29.1% of the rural dogs (P Ehrliquiose canina e babesiose canina são as doenças parasitárias transmitidas por carrapatos de maior prevalência em cães do Brasil. Poucos estudos pesquisaram doenças transmitidas por carrapatos na região da Amazônia brasileira. Um total de 129 amostras de sangue foram colhidas de cães da Amazônia oriental brasileira. Setenta e dois cães eram de áreas rurais de 19 municípios do Estado do Pará, e 57 amostras foram colhidas de cães errantes vadios da área urbana do município de Santarém-PA. As amostras de soro foram submetidas ao ensaio de imunofluorescência indireta, com antígenos de Babesia canis vogeli, Ehrlichia canis, e seis espécies de Rickettsia. A frequência de cães com anticorpos anti-B. canis vogeli, anti-E. canis, e anti-Rickettsia spp. foi de 42,6%, 16,2% e 31,7%, respectivamente. Anticorpos anti-B. canis vogeli foram detectados em 59,6% dos cães urbanos, e em 29,1% dos cães rurais (P < 0.05. Para E. canis, a soroprevalência foi parecida entre os cães urbanos (15,7% e rurais (16,6%. Para Rickettsia spp., cães rurais apresentaram prevalência (P < 0.05 significativamente

  15. Tick-borne encephalitis (TBE) and hepatitis B nonresponders feature different immunologic mechanisms in response to TBE and influenza vaccination with involvement of regulatory T and B cells and IL-10.

    Science.gov (United States)

    Garner-Spitzer, Erika; Wagner, Angelika; Paulke-Korinek, Maria; Kollaritsch, Herwig; Heinz, Franz X; Redlberger-Fritz, Monika; Stiasny, Karin; Fischer, Gottfried F; Kundi, Michael; Wiedermann, Ursula

    2013-09-01

    Low responsiveness/nonresponsiveness is characterized by an insufficient immune response upon primary and/or booster vaccination and affects 1-10% of vaccinees. In the current study, we aimed to investigate whether nonresponsiveness is an Ag/vaccine-specific phenomenon and to clarify underlying immunological mechanisms. Nonresponders to tick-borne encephalitis (TBE) or hepatitis B Ag with a history of previous TBE vaccinations were booster vaccinated with TBE and influenza vaccine and compared with TBE high responders in terms of humoral and cellular immune response. Postboosters in TBE high responder existing TBE titers increased, and solid humoral responses to influenza vaccine were induced. In TBE nonresponders, low to undetectable prevaccination TBE titers remained low, whereas sufficient influenza Abs were induced. In both TBE groups, a positive correlation of humoral and cellular immune response was seen as high/low TBE titers were associated with sufficient/lack of Ag-specific T cell proliferation. Furthermore, responses to influenza were robust in terms of Abs and cytokine production. In contrast, in hepatitis B nonresponders, sufficient humoral responses to TBE and influenza Ags were induced despite lacking specific IL-2 and IFN-γ production. Importantly, these patients showed high IL-10 baseline levels in vitro. HLA-DR subtypes associated with hepatitis B nonresponsiveness were overrepresented in this group, and high IL-10 levels were linked to these subtypes. Whereas TBE and hepatitis B nonresponders had increased IL-10-producing FOXP3(+) T regulatory cells upon vaccination, only in hepatitis B nonresponders, showing elevated prevaccination IL-10 levels, a prominent population of B regulatory cells was detected. We conclude that immunological pathways of nonresponsiveness follow different patterns depending both on vaccine Ag and genetic predisposition of the vaccinee. PMID:23872054

  16. Immunogenicity against Far Eastern and Siberian subtypes of tick-borne encephalitis (TBE) virus elicited by the currently available vaccines based on the European subtype: systematic review and meta-analysis.

    Science.gov (United States)

    Domnich, Alexander; Panatto, Donatella; Arbuzova, Eva Klementievna; Signori, Alessio; Avio, Ulderico; Gasparini, Roberto; Amicizia, Daniela

    2014-01-01

    Tick-borne encephalitis (TBE) virus, which is usually divided into European, Far Eastern and Siberian subtypes, is a serious public health problem in several European and Asian countries. Vaccination is the most effective measure to prevent TBE; cross-subtype protection elicited by the TBE vaccines is biologically plausible since all TBE virus subtypes are closely related. This manuscript systematically explores available data on the cross-subtype immunogenicity elicited by the currently available Western vaccines based on the European subtype. Completed immunization course of 3 doses of both Western vaccines determined very high seroconversion/seropositivity rates against both Far Eastern and Siberian subtypes among previously flavivirus-naïve subjects. All but one study found no statistically significant difference in titers of neutralizing antibodies against strains belonging to homologous and heterologous subtypes. Pooled analysis of randomized controlled trials on head-to-head comparison of immunogenicity of Western and Russian TBE vaccines did not reveal differences in seroconversion rates against Far Eastern isolates in either hemagglutination inhibition (risk ratio = 0.98, p = 0.83) or enzyme-linked immunosorbent (risk ratio = 0.95, p = 0.44) assays after 2 vaccine doses. This suggests that, in regions where a heterogeneous TBE virus population circulates, vaccines based on the European subtype may be used alongside vaccines based on the Far Eastern subtype. Studies on the field effectiveness of TBE vaccines and investigation of vaccination failures, especially in countries where different subtypes co-circulate, will further elucidate TBE vaccination-induced cross-subtype protection.

  17. Observed and predicted effects of climate change on species abundance in protected areas

    Science.gov (United States)

    Johnston, Alison; Ausden, Malcolm; Dodd, Andrew M.; Bradbury, Richard B.; Chamberlain, Dan E.; Jiguet, Frédéric; Thomas, Chris D.; Cook, Aonghais S. C. P.; Newson, Stuart E.; Ockendon, Nancy; Rehfisch, Mark M.; Roos, Staffan; Thaxter, Chris B.; Brown, Andy; Crick, Humphrey Q. P.; Douse, Andrew; McCall, Rob A.; Pontier, Helen; Stroud, David A.; Cadiou, Bernard; Crowe, Olivia; Deceuninck, Bernard; Hornman, Menno; Pearce-Higgins, James W.

    2013-12-01

    The dynamic nature and diversity of species' responses to climate change poses significant difficulties for developing robust, long-term conservation strategies. One key question is whether existing protected area networks will remain effective in a changing climate. To test this, we developed statistical models that link climate to the abundance of internationally important bird populations in northwestern Europe. Spatial climate-abundance models were able to predict 56% of the variation in recent 30-year population trends. Using these models, future climate change resulting in 4.0°C global warming was projected to cause declines of at least 25% for more than half of the internationally important populations considered. Nonetheless, most EU Special Protection Areas in the UK were projected to retain species in sufficient abundances to maintain their legal status, and generally sites that are important now were projected to be important in the future. The biological and legal resilience of this network of protected areas is derived from the capacity for turnover in the important species at each site as species' distributions and abundances alter in response to climate. Current protected areas are therefore predicted to remain important for future conservation in a changing climate.

  18. An Accurate Calculation of the Big-Bang Prediction for the Abundance of Primordial Helium

    CERN Document Server

    López, R E; Lopez, Robert E.; Turner, Michael S.

    1999-01-01

    Within the standard model of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of Helium to a theoretical uncertainty of $0.1 \\pct$ $(\\delta Y_P = \\pm 0.0002)$. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, $\\tau_n = 885.3 \\pm 2.0 \\rm{sec}$. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon mass corrections to the weak rates; order-$\\alpha$ quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code to control numerical errors to less than 0.1\\pct. Our predictions for the \\EL[4]{He} abundance are summarized with an accurate fitting formula. Summarizing our work...

  19. Non-explosive hydrogen and helium burnings Abundance predictions from the NACRE reaction rate compilation

    CERN Document Server

    Arnould, M; Jorissen, A

    1999-01-01

    The abundances of the isotopes of the elements from C to Al produced by the non-explosive CNO, NeNa and MgAl modes of hydrogen burning, as well as by helium burning, are calculated with the thermonuclear rates recommended by the European compilation of reaction rates for astrophysics (NACRE: details about NACRE may be found at http://astro.ulb.ac.be. This electronic address provides many data of nuclear astrophysics interest and also offers the possibility of generating interactively tables of reaction rates for networks and temperature grids selected by the user). The impact of nuclear physics uncertainties on the derived abundances is discussed in the framework of a simple parametric astrophysical model. These calculations have the virtue of being a guide in the selection of the nuclear uncertainties that have to be duly analyzed in detailed model stars, particularly in order to perform meaningful confrontations between abundance observations and predictions. They are also hoped to help nuclear astrophysici...

  20. Niche and neutral models predict asymptotically equivalent species abundance distributions in high-diversity ecological communities

    Science.gov (United States)

    Chisholm, Ryan A.; Pacala, Stephen W.

    2010-01-01

    A fundamental challenge in ecology is to understand the mechanisms that govern patterns of relative species abundance. Previous numerical simulations have suggested that complex niche-structured models produce species abundance distributions (SADs) that are qualitatively similar to those of very simple neutral models that ignore differences between species. However, in the absence of an analytical treatment of niche models, one cannot tell whether the two classes of model produce the same patterns via similar or different mechanisms. We present an analytical proof that, in the limit as diversity becomes large, a strong niche model give rises to exactly the same asymptotic form of SAD as the neutral model, and we verify the analytical predictions for a Panamanian tropical forest data set. Our results strongly suggest that neutral processes drive patterns of relative species abundance in high-diversity ecological communities, even when strong niche structure exists. However, neutral theory cannot explain what generates high diversity in the first place, and it may not be valid in low-diversity communities. Our results also confirm that neutral theory cannot be used to infer an absence of niche structure or to explain ecosystem function. PMID:20733073

  1. Improve accuracy and sensibility in glycan structure prediction by matching glycan isotope abundance

    Energy Technology Data Exchange (ETDEWEB)

    Xu Guang [College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan (China); National Research Council Canada, Ottawa, Ont., K1A 0R6 (Canada); Liu Xin [College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan (China); Liu Qingyan [National Research Council Canada, Ottawa, Ont., Canada K1A 0R6 (Canada); Zhou Yanhong, E-mail: yhzhou@mail.hust.edu.cn [College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan (China); Li Jianjun, E-mail: Jianjun.Li@nrc-cnrc.gc.ca [National Research Council Canada, Ottawa, Ont., Canada K1A 0R6 (Canada)

    2012-09-19

    Highlights: Black-Right-Pointing-Pointer A glycan isotope pattern recognition strategy for glycomics. Black-Right-Pointing-Pointer A new data preprocessing procedure to detect ion peaks in a giving MS spectrum. Black-Right-Pointing-Pointer A linear soft margin SVM classification for isotope pattern recognition. - Abstract: Mass Spectrometry (MS) is a powerful technique for the determination of glycan structures and is capable of providing qualitative and quantitative information. Recent development in computational method offers an opportunity to use glycan structure databases and de novo algorithms for extracting valuable information from MS or MS/MS data. However, detecting low-intensity peaks that are buried in noisy data sets is still a challenge and an algorithm for accurate prediction and annotation of glycan structures from MS data is highly desirable. The present study describes a novel algorithm for glycan structure prediction by matching glycan isotope abundance (mGIA), which takes isotope masses, abundances, and spacing into account. We constructed a comprehensive database containing 808 glycan compositions and their corresponding isotope abundance. Unlike most previously reported methods, not only did we take into count the m/z values of the peaks but also their corresponding logarithmic Euclidean distance of the calculated and detected isotope vectors. Evaluation against a linear classifier, obtained by training mGIA algorithm with datasets of three different human tissue samples from Consortium for Functional Glycomics (CFG) in association with Support Vector Machine (SVM), was proposed to improve the accuracy of automatic glycan structure annotation. In addition, an effective data preprocessing procedure, including baseline subtraction, smoothing, peak centroiding and composition matching for extracting correct isotope profiles from MS data was incorporated. The algorithm was validated by analyzing the mouse kidney MS data from CFG, resulting in the

  2. Predicting reproductive success from hormone concentrations in the common tern (Sterna hirundo) while considering food abundance.

    Science.gov (United States)

    Riechert, Juliane; Becker, Peter H; Chastel, Olivier

    2014-11-01

    In birds, reproductive success is mainly a function of skill or environmental conditions, but it can also be linked to hormone concentrations due to their effect on behavior and individual decisions made during reproduction. For example, a high prolactin concentration is required to express parental behaviors such as incubation or guarding and feeding the young. Corticosterone level, on the other hand, is related to energy allocation or stress and foraging or provisioning effort. In this study, we measured individual baseline prolactin and corticosterone between 2006 and 2012 in breeding common terns (Sterna hirundo) using blood-sucking bugs. Reproductive parameters as well as prey abundance on a local and a wider scale were also determined during this period. Baseline prolactin and corticosterone varied significantly between years, as did breeding success. At the individual level, prolactin was positively and corticosterone was negatively linked to herring and sprat abundance. At the population level, we also found a negative link between corticosterone and prey abundance, probably reflecting overall foraging conditions. High prolactin during incubation was mainly predictive of increased hatching success, potentially by supporting more constant incubation and nest-guarding behavior. It was also positively linked to a lesser extent with fledging success, which could indicate a high feeding rate of young. Corticosterone concentration was positively related to high breeding success, which may be due to increased foraging activity and feeding of young. In general, our study shows that baseline prolactin and corticosterone levels during incubation can predict reproductive success, despite the presence of an interval between sampling and hatching or fledging of young.

  3. Protect Yourself against Tick-Borne Disease

    Science.gov (United States)

    ... males, many of whom spend more time outdoors, hunting, hiking, fishing and such, are more likely to ... Prepare for Biological Threats More in Consumer Updates Animal & Veterinary Children's Health Cosmetics Dietary Supplements Drugs Food ...

  4. Hierarchical spatial models for predicting pygmy rabbit distribution and relative abundance

    Science.gov (United States)

    Wilson, T.L.; Odei, J.B.; Hooten, M.B.; Edwards, T.C., Jr.

    2010-01-01

    Conservationists routinely use species distribution models to plan conservation, restoration and development actions, while ecologists use them to infer process from pattern. These models tend to work well for common or easily observable species, but are of limited utility for rare and cryptic species. This may be because honest accounting of known observation bias and spatial autocorrelation are rarely included, thereby limiting statistical inference of resulting distribution maps. We specified and implemented a spatially explicit Bayesian hierarchical model for a cryptic mammal species (pygmy rabbit Brachylagus idahoensis). Our approach used two levels of indirect sign that are naturally hierarchical (burrows and faecal pellets) to build a model that allows for inference on regression coefficients as well as spatially explicit model parameters. We also produced maps of rabbit distribution (occupied burrows) and relative abundance (number of burrows expected to be occupied by pygmy rabbits). The model demonstrated statistically rigorous spatial prediction by including spatial autocorrelation and measurement uncertainty. We demonstrated flexibility of our modelling framework by depicting probabilistic distribution predictions using different assumptions of pygmy rabbit habitat requirements. Spatial representations of the variance of posterior predictive distributions were obtained to evaluate heterogeneity in model fit across the spatial domain. Leave-one-out cross-validation was conducted to evaluate the overall model fit. Synthesis and applications. Our method draws on the strengths of previous work, thereby bridging and extending two active areas of ecological research: species distribution models and multi-state occupancy modelling. Our framework can be extended to encompass both larger extents and other species for which direct estimation of abundance is difficult. ?? 2010 The Authors. Journal compilation ?? 2010 British Ecological Society.

  5. Cluster abundance in chameleon $f(R)$ gravity I: toward an accurate halo mass function prediction

    CERN Document Server

    Cataneo, Matteo; Lombriser, Lucas; Li, Baojiu

    2016-01-01

    We refine the mass and environment dependent spherical collapse model of chameleon $f(R)$ gravity by calibrating a phenomenological correction inspired by the parameterized post-Friedmann framework against high-resolution $N$-body simulations. We employ our method to predict the corresponding modified halo mass function, and provide fitting formulas to calculate the fractional enhancement of the $f(R)$ halo abundance with respect to that of General Relativity (GR) within a precision of $\\lesssim 5\\%$ from the results obtained in the simulations. Similar accuracy can be achieved for the full $f(R)$ mass function on the condition that the modeling of the reference GR abundance of halos is accurate at the percent level. We use our fits to forecast constraints on the additional scalar degree of freedom of the theory, finding that upper bounds competitive with current Solar System tests are within reach of cluster number count analyses from ongoing and upcoming surveys at much larger scales. Importantly, the flexi...

  6. Functional traits predict relationship between plant abundance dynamic and long-term climate warming.

    Science.gov (United States)

    Soudzilovskaia, Nadejda A; Elumeeva, Tatiana G; Onipchenko, Vladimir G; Shidakov, Islam I; Salpagarova, Fatima S; Khubiev, Anzor B; Tekeev, Dzhamal K; Cornelissen, Johannes H C

    2013-11-01

    Predicting climate change impact on ecosystem structure and services is one of the most important challenges in ecology. Until now, plant species response to climate change has been described at the level of fixed plant functional types, an approach limited by its inflexibility as there is much interspecific functional variation within plant functional types. Considering a plant species as a set of functional traits greatly increases our possibilities for analysis of ecosystem functioning and carbon and nutrient fluxes associated therewith. Moreover, recently assembled large-scale databases hold comprehensive per-species data on plant functional traits, allowing a detailed functional description of many plant communities on Earth. Here, we show that plant functional traits can be used as predictors of vegetation response to climate warming, accounting in our test ecosystem (the species-rich alpine belt of Caucasus mountains, Russia) for 59% of variability in the per-species abundance relation to temperature. In this mountain belt, traits that promote conservative leaf water economy (higher leaf mass per area, thicker leaves) and large investments in belowground reserves to support next year's shoot buds (root carbon content) were the best predictors of the species increase in abundance along with temperature increase. This finding demonstrates that plant functional traits constitute a highly useful concept for forecasting changes in plant communities, and their associated ecosystem services, in response to climate change. PMID:24145400

  7. Functional traits predict relationship between plant abundance dynamic and long-term climate warming.

    Science.gov (United States)

    Soudzilovskaia, Nadejda A; Elumeeva, Tatiana G; Onipchenko, Vladimir G; Shidakov, Islam I; Salpagarova, Fatima S; Khubiev, Anzor B; Tekeev, Dzhamal K; Cornelissen, Johannes H C

    2013-11-01

    Predicting climate change impact on ecosystem structure and services is one of the most important challenges in ecology. Until now, plant species response to climate change has been described at the level of fixed plant functional types, an approach limited by its inflexibility as there is much interspecific functional variation within plant functional types. Considering a plant species as a set of functional traits greatly increases our possibilities for analysis of ecosystem functioning and carbon and nutrient fluxes associated therewith. Moreover, recently assembled large-scale databases hold comprehensive per-species data on plant functional traits, allowing a detailed functional description of many plant communities on Earth. Here, we show that plant functional traits can be used as predictors of vegetation response to climate warming, accounting in our test ecosystem (the species-rich alpine belt of Caucasus mountains, Russia) for 59% of variability in the per-species abundance relation to temperature. In this mountain belt, traits that promote conservative leaf water economy (higher leaf mass per area, thicker leaves) and large investments in belowground reserves to support next year's shoot buds (root carbon content) were the best predictors of the species increase in abundance along with temperature increase. This finding demonstrates that plant functional traits constitute a highly useful concept for forecasting changes in plant communities, and their associated ecosystem services, in response to climate change.

  8. Low abundance of the matrix arm of complex I in mitochondria predicts longevity in mice.

    Science.gov (United States)

    Miwa, Satomi; Jow, Howsun; Baty, Karen; Johnson, Amy; Czapiewski, Rafal; Saretzki, Gabriele; Treumann, Achim; von Zglinicki, Thomas

    2014-05-12

    Mitochondrial function is an important determinant of the ageing process; however, the mitochondrial properties that enable longevity are not well understood. Here we show that optimal assembly of mitochondrial complex I predicts longevity in mice. Using an unbiased high-coverage high-confidence approach, we demonstrate that electron transport chain proteins, especially the matrix arm subunits of complex I, are decreased in young long-living mice, which is associated with improved complex I assembly, higher complex I-linked state 3 oxygen consumption rates and decreased superoxide production, whereas the opposite is seen in old mice. Disruption of complex I assembly reduces oxidative metabolism with concomitant increase in mitochondrial superoxide production. This is rescued by knockdown of the mitochondrial chaperone, prohibitin. Disrupted complex I assembly causes premature senescence in primary cells. We propose that lower abundance of free catalytic complex I components supports complex I assembly, efficacy of substrate utilization and minimal ROS production, enabling enhanced longevity.

  9. Survey on tick-borne anaplasmataceae in the south edge of Gurbantunggut desert%古尔班通古特沙漠南缘蜱携带无形体的调查

    Institute of Scientific and Technical Information of China (English)

    孟庆玲; 乔军; 盛金良; 王俊伟; 王为升; 姚娜; 陈创夫; 张丽娟

    2012-01-01

    To understand the tick-borne anaplasmataceae in the south edge of Gurbantunggut desert, ticks specimens from 11 sites in three different habitats areas were collected and identified. Nested PCR was carried to detect positive ticks carring anaplasmataceae,and then 5% end variable region of 16S rRNA gene of anaplasmataceae was amplified by semi-nested PCR for cloning and sequencing. The obtained DNA sequences were compared with the GenBank sequence and phylogenetic tree was constructed with the Mega 5.0 software. The 708 ticks collected from 11 sites were identified as 4 genera and 8 species. 25 were detected positive in the 236 tick samples, with a positive rate of 10.59 %. By sequence analyses, Ehrlichia cha ff eensis , Ehrlichia eanis , Ana plasrna marginale and Ana plasrna ovis were positive in Hyalomrna asiaticum ,Rhipicephalus sanguineeus , Hyalornma detritum and Haemaphysalis longi- cornis,respectively. The results showed that there exists anaplasmataceae in ticks parasited in livestock from the south edge of Gurbantunggut desert,suggesting that the region may be one of natural loci of anaplasmosis.%为了解古尔班通古特沙漠南缘蜱携带无形体的状况,在该地域3个不同生境区域11个地点采集家畜寄生蜱标本,进行分类鉴定;运用套式PCR筛选无形体阳性蜱样本,并用半套式PCR扩增无形体科16SrRNA基因5′端高变区,进行克隆测序;将所获得的DNA序列与GenBank收录的序列作比对,并用Mega 5.0软件构建系统发育树,鉴定蜱携带无形体的种类。结果共采集708只蜱,鉴定为4个属8个种。在分类后的236份蜱样本中,检测出无形体阳性25份,阳性率为10.59%。序列比较发现,在亚洲璃眼蜱、血红扇头蜱、残缘璃眼蜱、长角血蜱中分别存在查菲埃立克体(Ehrlichia chaffeensis)、犬埃立克体(Ehrlichia canis)、边缘无形体(Anaplasma marginale)和绵羊无形体(Anaplasma ovis)的16SrRNA基因片段。研究结果证实

  10. Using a data-constrained model of home range establishment to predict abundance in spatially heterogeneous habitats.

    Directory of Open Access Journals (Sweden)

    Mark C Vanderwel

    Full Text Available Mechanistic modelling approaches that explicitly translate from individual-scale resource selection to the distribution and abundance of a larger population may be better suited to predicting responses to spatially heterogeneous habitat alteration than commonly-used regression models. We developed an individual-based model of home range establishment that, given a mapped distribution of local habitat values, estimates species abundance by simulating the number and position of viable home ranges that can be maintained across a spatially heterogeneous area. We estimated parameters for this model from data on red-backed vole (Myodes gapperi abundances in 31 boreal forest sites in Ontario, Canada. The home range model had considerably more support from these data than both non-spatial regression models based on the same original habitat variables and a mean-abundance null model. It had nearly equivalent support to a non-spatial regression model that, like the home range model, scaled an aggregate measure of habitat value from local associations with habitat resources. The home range and habitat-value regression models gave similar predictions for vole abundance under simulations of light- and moderate-intensity partial forest harvesting, but the home range model predicted lower abundances than the regression model under high-intensity disturbance. Empirical regression-based approaches for predicting species abundance may overlook processes that affect habitat use by individuals, and often extrapolate poorly to novel habitat conditions. Mechanistic home range models that can be parameterized against abundance data from different habitats permit appropriate scaling from individual- to population-level habitat relationships, and can potentially provide better insights into responses to disturbance.

  11. Archaeal abundance in post-mortem ruminal digesta may help predict methane emissions from beef cattle

    Science.gov (United States)

    Wallace, R. John; Rooke, John A.; Duthie, Carol-Anne; Hyslop, Jimmy J.; Ross, David W.; McKain, Nest; de Souza, Shirley Motta; Snelling, Timothy J.; Waterhouse, Anthony; Roehe, Rainer

    2014-07-01

    Methane produced from 35 Aberdeen-Angus and 33 Limousin cross steers was measured in respiration chambers. Each group was split to receive either a medium- or high-concentrate diet. Ruminal digesta samples were subsequently removed to investigate correlations between methane emissions and the rumen microbial community, as measured by qPCR of 16S or 18S rRNA genes. Diet had the greatest influence on methane emissions. The high-concentrate diet resulted in lower methane emissions (P < 0.001) than the medium-concentrate diet. Methane was correlated, irrespective of breed, with the abundance of archaea (R = 0.39), bacteria (-0.47), protozoa (0.45), Bacteroidetes (-0.37) and Clostridium Cluster XIVa (-0.35). The archaea:bacteria ratio provided a stronger correlation (0.49). A similar correlation was found with digesta samples taken 2-3 weeks later at slaughter. This finding could help enable greenhouse gas emissions of large animal cohorts to be predicted from samples taken conveniently in the abattoir.

  12. Generalized Additive Models Used to Predict Species Abundance in the Gulf of Mexico: An Ecosystem Modeling Tool

    Science.gov (United States)

    Drexler, Michael; Ainsworth, Cameron H.

    2013-01-01

    Spatially explicit ecosystem models of all types require an initial allocation of biomass, often in areas where fisheries independent abundance estimates do not exist. A generalized additive modelling (GAM) approach is used to describe the abundance of 40 species groups (i.e. functional groups) across the Gulf of Mexico (GoM) using a large fisheries independent data set (SEAMAP) and climate scale oceanographic conditions. Predictor variables included in the model are chlorophyll a, sediment type, dissolved oxygen, temperature, and depth. Despite the presence of a large number of zeros in the data, a single GAM using a negative binomial distribution was suitable to make predictions of abundance for multiple functional groups. We present an example case study using pink shrimp (Farfantepenaeus duroarum) and compare the results to known distributions. The model successfully predicts the known areas of high abundance in the GoM, including those areas where no data was inputted into the model fitting. Overall, the model reliably captures areas of high and low abundance for the large majority of functional groups observed in SEAMAP. The result of this method allows for the objective setting of spatial distributions for numerous functional groups across a modeling domain, even where abundance data may not exist. PMID:23691223

  13. Generalized additive models used to predict species abundance in the Gulf of Mexico: an ecosystem modeling tool.

    Directory of Open Access Journals (Sweden)

    Michael Drexler

    Full Text Available Spatially explicit ecosystem models of all types require an initial allocation of biomass, often in areas where fisheries independent abundance estimates do not exist. A generalized additive modelling (GAM approach is used to describe the abundance of 40 species groups (i.e. functional groups across the Gulf of Mexico (GoM using a large fisheries independent data set (SEAMAP and climate scale oceanographic conditions. Predictor variables included in the model are chlorophyll a, sediment type, dissolved oxygen, temperature, and depth. Despite the presence of a large number of zeros in the data, a single GAM using a negative binomial distribution was suitable to make predictions of abundance for multiple functional groups. We present an example case study using pink shrimp (Farfantepenaeus duroarum and compare the results to known distributions. The model successfully predicts the known areas of high abundance in the GoM, including those areas where no data was inputted into the model fitting. Overall, the model reliably captures areas of high and low abundance for the large majority of functional groups observed in SEAMAP. The result of this method allows for the objective setting of spatial distributions for numerous functional groups across a modeling domain, even where abundance data may not exist.

  14. 浙江省鼠形动物蜱源立克次体感染状况调查%A Cross-sectional study on tick-borne Rickettsiae infections among murine-like animals

    Institute of Scientific and Technical Information of China (English)

    柴程良; 陈恩富; 孙继民; 陆群英; 凌锋; 姜理平; 葛君华; 顾时平; 叶晓东; 刘社兰

    2014-01-01

    .32%),Apodemus agrarius (18.80%) and Thallomys paedulcus (1 1.75%)and they were significantly different among three areas (P<0.05 ).48 Rickettsia positive were found in 562 tested samples with the positive rate of 8.54%,among which the percentage of Anaplasma,typhus group Rickettsia, Orientia,Ehrlichia and spotted fever group Rickettsia were 3.38%,1.78%,1.78%,1.07% and 0.53% respectively. The positive rates of Anaplasma in Jindong (4.76%)and Anji (4.27%)were significantly higher than that in Tiantai (P<0.05 )while the spotted fever group Rickettsia were found only in Tiantai County.Moreover,Rattus confucianus-the predominant species of Zhejiang Province-had the highest infection rate of tick-borne Rickettsiae up to 14.97%.Co-infections with several Rickettsiae were existed among the same species.Conclusion Rickettsiae infections exist widely among different areas of Zhejiang province and the positive rates are significantly different among species.

  15. Prediction of abundance of ants according to climate change scenarios RCP 4.5 and 8.5 in South Korea

    OpenAIRE

    Tae-Sung Kwon; Cheol Min Lee

    2015-01-01

    In order to identify change of ant distribution expected due to climate change in South Korea, data on ants collected from 344 forest sites were used to predict change of abundance of ant species. In distribution of abundance along temperature gradient, 16 species displayed the patterns expected from normal distribution. For these species, abundance in temperature zones was used to link with temperature changes and predict the abundance. Temperature changes were based on Representative Concen...

  16. Use of stoichiometry to predict the abundance and functioning of root symbioses

    Science.gov (United States)

    Johnson, N. C.

    2012-04-01

    Plants form nutritional symbioses with fungi and bacteria and the importance of these partnerships varies with the mineral fertility of soil. There is strong evidence that plants acclimate and adapt to their local soil conditions through root symbioses; nitrogen limitation is ameliorated by symbiosis with diazotrophic prokaryotes and mycorrhizas ameliorate phosphorus limitation. Corollaries of ecological stoichiometry may be useful for predicting the abundance and functioning of mycorrhizas and N-fixation symbioses. A series of field experiments show that arbuscular mycorrhizal (AM) symbioses in grasslands in North America and in the African Serengeti are most beneficial to plant nutrition when plants are phosphorus limited and have sufficient nitrogen and carbon. A reciprocal inoculation experiment shows that locally adapted communities of AM fungi, associated soil organisms and plants arise such that mutualistic benefits are maximized; both AM fungi and plants grew best in their "home" soil-symbiont combination compared to "away" soil-symbiont combinations. Plants in their home combination acquired more limiting resource (either phosphorus or nitrogen) and consequently grew larger; similarly, AM fungi in their home combination formed more arbuscules and extraradical hyphae. Genetic analysis of the AM fungi inside plant roots indicate that these results correspond to variation in the community composition of AM fungi and also to variation in the symbiotic performance of local isolates of one particular species of AM fungus. The next step is to conduct landscape scale studies of root symbioses to test the hypothesis that plants cultivate microbial communities in and around their roots such that the species and ecotypes of microorganisms within these communities is customized for optimal nutrient acquisition under site-specific environmental conditions. If locally adapted communities of root and rhizosphere organisms are common, then plants may be optimizing their

  17. Predicting the abundance of ice nucleating particles of biological origin in precipitation

    Science.gov (United States)

    Stopelli, Emiliano; Conen, Franz; Morris, Cindy; Alewell, Christine

    2016-04-01

    Ice nucleation is a key step for the formation of precipitation on Earth. Ice nucleating particles (INPs) of biological origin catalyse the freezing of supercooled cloud droplets at temperatures warmer than -12 ° C. In order to understand the effective role of these INPs in conditioning precipitation, it is of primary importance to describe and predict their variability in the atmosphere. Over the course of two years, 14 sampling campaigns in precipitating clouds were conducted at the High Altitude Research Station Jungfraujoch, in the Swiss Alps, at 3580 m a.s.l. A total of 106 freshly fallen snow samples were analysed immediately on site for the concentration of INPs active at -8 ° C (INPs‑8) by immersion freezing. Values of INPs‑8 ranged from 0.21 to 434ṡml‑1. Environmental parameters (like temperature of the air, wind speed, the stable oxygen ratio δ18O of snow, the number of particles larger than 0.5 μm) were used as independent variables to build a set of multiple linear regression models to describe and predict the observed variations of INPs‑8 over time. The model providing the best results was based on fV (the fraction of remaining vapour in precipitating clouds, derived from δ18O) and on wind speed. It indicates that a coincidence of strong atmospheric turbulence and little prior precipitation from a cloud coincides with large concentrations of INPs‑8. These conditions can be frequently encountered when air masses are suddenly forced to rise, for instance by the passage of a cold front, where also meteorological conditions are favourable to the onset of precipitation. To obtain more information on the presence of INPs‑8 of biological origin and their relative composition, a set of precipitation samples were progressively filtered through different meshes (5 μm, 1.2 μm, 0.22 μm) followed by heating (40 ° C and 80 ° C). Almost all ice nucleating activity is lost after heating at 80 ° C, and a significant part of INPs‑8 is

  18. Climatic Variables Do Not Directly Predict Spider Richness and Abundance in Semiarid Caatinga Vegetation, Brazil.

    Science.gov (United States)

    Carvalho, Leonardo S; Sebastian, Nicholas; Araújo, Helder F P; Dias, Sidclay C; Venticinque, Eduardo; Brescovit, Antonio D; Vasconcellos, Alexandre

    2015-02-01

    Spiders are abundant in tropical ecosystems and exert predatory pressure on a wide variety of invertebrate populations and also serve as prey for many others organisms, being part of complex interrelationships influenced directly and indirectly by a myriad of factors. We examined the influence of biotic (i.e., prey availability) and abiotic (i.e., temperature, precipitation, relative humidity, real evapotranspiration) factors on species richness and abundance during a two-year period in the semiarid Caatinga vegetation in northeastern Brazil. Data were analyzed through partial autocorrelation functions, cross correlations, and a path analysis. A total of 2522 spiders were collected with beating tray, pit-fall traps, and malaise traps, comprising 91 species and 34 families. Spider abundance peaked in the rainy season. Our results suggest that total invertebrate abundance has a direct influence on spider richness and abundance, whereas the effects of precipitation were mainly indirectly related to most spider assemblage parameters. The increase in vegetation cover with the rainy season in the Caatinga provides more breeding and foraging sites for spiders and stimulates their activities. Additionally, rainfall in arid and semiarid ecosystems stimulated the activity and reproduction of many herbivore and detritivore invertebrates dependent on plant biomass and necromass consumption, leading to an increase in spider prey availability. PMID:26308806

  19. Predicting foundation bunchgrass species abundances: Model-assisted decision-making in protected-area sagebrush steppe

    Science.gov (United States)

    Rodhouse, Thomas J.; Irvine, Kathryn M.; Sheley, Roger L.; Smith, Brenda S.; Hoh, Shirley; Esposito, Daniel M.; Mata-Gonzalez, Ricardo

    2014-01-01

    Foundation species are structurally dominant members of ecological communities that can stabilize ecological processes and influence resilience to disturbance and resistance to invasion. Being common, they are often overlooked for conservation but are increasingly threatened from land use change, biological invasions, and over-exploitation. The pattern of foundation species abundances over space and time may be used to guide decision-making, particularly in protected areas for which they are iconic. We used ordinal logistic regression to identify the important environmental influences on the abundance patterns of bluebunch wheatgrass (Pseudoroegneria spicata), Thurber's needlegrass (Achnatherum thurberianum), and Sandberg bluegrass (Poa secunda) in protected-area sagebrush steppe. We then predicted bunchgrass abundances along gradients of topography, disturbance, and invasive annual grass abundance. We used model predictions to prioritize the landscape for implementation of a management and restoration decision-support tool. Models were fit to categorical estimates of grass cover obtained from an extensive ground-based monitoring dataset. We found that remnant stands of abundant wheatgrass and bluegrass were associated with steep north-facing slopes in higher and more remote portions of the landscape outside of recently burned areas where invasive annual grasses were less abundant. These areas represented only 25% of the landscape and were prioritized for protection efforts. Needlegrass was associated with south-facing slopes, but in low abundance and in association with invasive cheatgrass (Bromus tectorum). Abundances of all three species were strongly negatively correlated with occurrence of another invasive annual grass, medusahead (Taeniatherum caput-medusae). The rarity of priority bunchgrass stands underscored the extent of degradation and the need for prioritization. We found no evidence that insularity reduced invasibility; annual grass invasion represents

  20. Models of Experimentally Derived Competitive Effects Predict Biogeographical Differences in the Abundance of Invasive and Native Plant Species

    Science.gov (United States)

    Xiao, Sa; Ni, Guangyan; Callaway, Ragan M.

    2013-01-01

    Mono-dominance by invasive species provides opportunities to explore determinants of plant distributions and abundance; however, linking mechanistic results from small scale experiments to patterns in nature is difficult. We used experimentally derived competitive effects of an invader in North America, Acroptilon repens, on species with which it co-occurs in its native range of Uzbekistan and on species with which it occurs in its non-native ranges in North America, in individual-based models. We found that competitive effects yielded relative abundances of Acroptilon and other species in models that were qualitatively similar to those observed in the field in the two ranges. In its non-native range, Acroptilon can occur in nearly pure monocultures at local scales, whereas such nearly pure stands of Acroptilon appear to be much less common in its native range. Experimentally derived competitive effects of Acroptilon on other species predicted Acroptilon to be 4–9 times more proportionally abundant than natives in the North American models, but proportionally equal to or less than the abundance of natives in the Eurasian models. Our results suggest a novel way to integrate complex combinations of interactions simultaneously, and that biogeographical differences in the competitive effects of an invader correspond well with biogeographical differences in abundance and impact. PMID:24265701

  1. Models of experimentally derived competitive effects predict biogeographical differences in the abundance of invasive and native plant species.

    Directory of Open Access Journals (Sweden)

    Sa Xiao

    Full Text Available Mono-dominance by invasive species provides opportunities to explore determinants of plant distributions and abundance; however, linking mechanistic results from small scale experiments to patterns in nature is difficult. We used experimentally derived competitive effects of an invader in North America, Acroptilon repens, on species with which it co-occurs in its native range of Uzbekistan and on species with which it occurs in its non-native ranges in North America, in individual-based models. We found that competitive effects yielded relative abundances of Acroptilon and other species in models that were qualitatively similar to those observed in the field in the two ranges. In its non-native range, Acroptilon can occur in nearly pure monocultures at local scales, whereas such nearly pure stands of Acroptilon appear to be much less common in its native range. Experimentally derived competitive effects of Acroptilon on other species predicted Acroptilon to be 4-9 times more proportionally abundant than natives in the North American models, but proportionally equal to or less than the abundance of natives in the Eurasian models. Our results suggest a novel way to integrate complex combinations of interactions simultaneously, and that biogeographical differences in the competitive effects of an invader correspond well with biogeographical differences in abundance and impact.

  2. Species abundance distributions : moving beyond single prediction theories to integration within an ecological framework

    NARCIS (Netherlands)

    McGill, Brian J.; Etienne, Rampal S.; Gray, John S.; Alonso, David; Anderson, Marti J.; Benecha, Habtamu Kassa; Dornelas, Maria; Enquist, Brian J.; Green, Jessica L.; He, Fangliang; Hurlbert, Allen H.; Magurran, Anne E.; Marquet, Pablo A.; Maurer, Brian A.; Ostling, Annette; Soykan, Candan U.; Ugland, Karl I.; White, Ethan P.

    2007-01-01

    Species abundance distributions (SADs) follow one of ecology's oldest and most universal laws - every community shows a hollow curve or hyperbolic shape on a histogram with many rare species and just a few common species. Here, we review theoretical, empirical and statistical developments in the stu

  3. Species abundance distributions: moving beyond single prediction theories to integration within an ecological framework

    NARCIS (Netherlands)

    McGill, B.J.; Etienne, R.S.; Gray, J.S.; Alonso, D.; Anderson, M.J.; Benecha, H.K.

    2007-01-01

    Species abundance distributions (SADs) follow one of ecology's oldest and most universal laws ¿ every community shows a hollow curve or hyperbolic shape on a histogram with many rare species and just a few common species. Here, we review theoretical, empirical and statistical developments in the stu

  4. MULTIPLE INFECTIONS OF TICK-BORNE PATHOGENS IN IXODES PERSULCATUS COLLECTED FROM FORESTS IN HEILONGJIANG PROVINCE%黑龙江省部分林区全沟硬蜱复合感染重要蜱媒病原的调查研究

    Institute of Scientific and Technical Information of China (English)

    孙毅; 刘国平; 杨丽炜; 许荣满; 虞以新

    2007-01-01

    为了研究我国重要蜱媒病的复合感染情况,本文选择黑龙江林区蜱媒疾病高发区域,以莱姆病、森林脑炎、人巴贝西原虫病、埃立克体等蜱媒病原为目标,应用聚合酶链式反应对该地区采集的全沟硬蜱可能感染的蜱媒病原情况进行检测,以探讨这些蜱媒疾病在媒介全沟硬蜱体内的复合感染状况.结果表明,该地区的全沟硬蜱感染有莱姆病、森林脑炎、人巴贝西原虫病、埃立克体、斑点热等5种疾病的病原体,感染阳性率在1.05%~10.5%之间;在这些感染个体中,将近40%的个体属于复合感染,复合感染的类型有双重感染和三重感染.其中,莱姆病螺旋体和其他病原体复合感染的比例很高;没有发现埃立克体和人巴贝西原虫的复合感染现象.我国蜱媒病原的复合感染情况,理应引起预防、临床和公共卫生相关人员的充分关注.%Total 854 hungry adult taiga ticks Ixodes persulcatus collected from forests from Heilongjiang province were screened for dangerous tick borne pathogens using PCR techniques. These pathogens included 2 Lyme diseases agents, 2 Ehrlichiosis agents,2 Babesiosis agents and tick borne encephalitis and spotted fever group rickettsia. Prevalence of I. persulcatus ranged from 1.5 %to 10.5% with different pathogens respectively. About 40% ticks were multiply infected with these pathogens. Lyme disease agent Borrelia garinii and B. afzelii appeared to be readily to infect in I. persulcatus combined with other pathogens. Besides the combination types between Ehrlichia spp. and Babesia microti, other types of multiple infections were also detectable.Although no quadruple infection were found co-infected, triple infection were common and might be a cue to know the capacity of ticks to carry multiple pathogens. The knowledge of co-infection would be helpful for practitioners in diagnosis and proper treatment of tick borne diseases.

  5. 河北省西部山区蜱传斑点热群立克次体分子流行病学研究%Molecular epidemiological study of tick-borne spotted fever group Rickettsia in western mountain area of Hebei province, China

    Institute of Scientific and Technical Information of China (English)

    冯帅; 吴含; 张力文; 路朝旭; 张成龙; 李志平; 张荣贞; 周慧

    2013-01-01

    Objective To investigate the prevalence of tick-borne spotted fever group Rickettsia (SFGR) in the western mountain area of Hebei province,China and to provide a scientific basis for the prevention and control of tick-borne SFGR.Methods One set of specific primers,designed according to the outer membrane protein A (OmpA) gene sequence of SFGR,were used to amplify the OmpA gene in DNA samples extracted from Haemaphysalis longicornis collected in the western mountain area of Hebei province,and the positive samples were subjected to sequencing and sequence analysis to establish the molecular phylogenetic tree.Results Of 1227 DNA samples,91 (7.42%) were positive for SFGR.The phylogenetic analysis based on nucleotide sequence showed that all detected SFGR strains were clustered together with Candidatus Rickettsia hebeiii (accession numbers:HQ651815,HQ651817,HQ651818,HQ651819,HQ651823,and HQ651824) and Rickettsia sp.Fujian strain FUJ (accession number:AF169629); these strains had the highest homology with Candidatus R.hebeiii (99.02%),followed by Rickettsia sp.Fujian strain FUJ (98.50%),Rickettsia sp.Suifen strain HLJ-054 (accession number:AF179362) and Rickettsia sp.Hulin strain HL-93 (accession number:AF179364) (98.13%),and Rickettsia sp.Japanese strain YM (accession number:U43795) (97.92%).Conclusion Tick-borne SFGR is prevalent in the western mountain area of Hebei province.Preventive measures should be taken in time to protect humans and animals from this disease.%目的 调查河北省西部山区蜱类斑点热群立克次体带菌情况,为蜱传斑点热群防控提供科学依据.方法 根据已发表斑点热群立克次体OmpA外膜蛋白基因序列设计特异性引物,对河北省西部山区采集的长角血蜱进行PCR检测,并对阳性样本进行测序和序列分析,建立分子系统进化树.结果 在1227份蜱DNA样本中检测出91份阳性,阳性率为7.42%;序列分析结果显示河北省西部山区长角血蜱携带立克

  6. Application of mass-predictions to isotope-abundances in breeder-reactor cores

    CERN Document Server

    Kirchner, G

    1981-01-01

    The decay-heat and isotope composition of breeder reactor-cores is calculated at normal shut-down, and a core disintegration event. Using the ORIGEN-code, the influence of the most neutron-rich fission-yield nuclei is studied. Their abundances depend on the assumption about the nuclear data (mass and half-lives). The total decay-heat is not changed from any technical viewpoint. (15 refs).

  7. Application of mass-predictions to isotope-abundances in breeder-reactor cores

    International Nuclear Information System (INIS)

    The decay-heat and isotope composition of breeder reactor-cores is calculated at normal shut-down, and a core disintegration event. Using the ORIGRN-code, the influence of the most neutron-rich fission-yield nuclei is studied. Their abundances depend on the assumption about the nuclear data (mass and half-lives). The total decay-heat is not changed from any technically view-point. (orig.)

  8. Tree Species Abundance Predictions in a Tropical Agricultural Landscape with a Supervised Classification Model and Imbalanced Data

    Directory of Open Access Journals (Sweden)

    Sarah J. Graves

    2016-02-01

    Full Text Available Mapping species through classification of imaging spectroscopy data is facilitating research to understand tree species distributions at increasingly greater spatial scales. Classification requires a dataset of field observations matched to the image, which will often reflect natural species distributions, resulting in an imbalanced dataset with many samples for common species and few samples for less common species. Despite the high prevalence of imbalanced datasets in multiclass species predictions, the effect on species prediction accuracy and landscape species abundance has not yet been quantified. First, we trained and assessed the accuracy of a support vector machine (SVM model with a highly imbalanced dataset of 20 tropical species and one mixed-species class of 24 species identified in a hyperspectral image mosaic (350–2500 nm of Panamanian farmland and secondary forest fragments. The model, with an overall accuracy of 62% ± 2.3% and F-score of 59% ± 2.7%, was applied to the full image mosaic (23,000 ha at a 2-m resolution to produce a species prediction map, which suggested that this tropical agricultural landscape is more diverse than what has been presented in field-based studies. Second, we quantified the effect of class imbalance on model accuracy. Model assessment showed a trend where species with more samples were consistently over predicted while species with fewer samples were under predicted. Standardizing sample size reduced model accuracy, but also reduced the level of species over- and under-prediction. This study advances operational species mapping of diverse tropical landscapes by detailing the effect of imbalanced data on classification accuracy and providing estimates of tree species abundance in an agricultural landscape. Species maps using data and methods presented here can be used in landscape analyses of species distributions to understand human or environmental effects, in addition to focusing conservation

  9. Dynamical 3-Space Predicts Hotter Early Universe: Resolves CMB-BBN 7-Li and 4-He Abundance Anomalies

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2010-01-01

    Full Text Available The observed abundances of 7-Li and 4-He are significantly inconsistent with the predictions from Big Bang Nucleosynthesis (BBN when using the $Lambda$CDM cosmological model together with the value for $Omega_B h^2 = 0.0224pm0.0009$ from WMAP CMB fluctuations, with the value from BBN required to fit observed abundances being $0.009 < Omega_B h^2 < 0.013$. The dynamical 3-space theory is shown to predict a 20% hotter universe in the radiation-dominated epoch, which then results in a remarkable parameter-free agreement between the BBN and the WMAP value for $Omega_B h^2$. The dynamical 3-space also gives a parameter-free fit to the supernova redshift data, and predicts that the flawed $Lambda$CDM model would require $Omega_Lambda = 0.73$ and $Omega_M = 0.27$ to fit the 3-space dynamics Hubble expansion, and independently of the supernova data. These results amount to the discovery of new physics for the early universe that is matched by numerous other successful observational and experimental tests.

  10. Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance.

    Directory of Open Access Journals (Sweden)

    Ilja Sonnemann

    Full Text Available Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae larvae (43% in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive- and vegetative plant height, and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio. Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of

  11. Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance.

    Science.gov (United States)

    Sonnemann, Ilja; Pfestorf, Hans; Jeltsch, Florian; Wurst, Susanne

    2015-01-01

    Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae) larvae (43%) in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive- and vegetative plant height), and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio). Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of insect root

  12. Predicted CALET measurements of ultra-heavy cosmic ray relative abundances

    Science.gov (United States)

    Rauch, B. F.

    2014-05-01

    The CALorimetric Electron Telescope (CALET) is an imaging calorimeter under construction for launch to the ISS in 2014 for a planned 5 year mission. CALET consists of a charge detection module (CHD) with two segmented planes of 1 cm thick plastic scintillator, an imaging calorimeter (IMC) with a total of 3 radiation lengths (X∘) of tungsten plates read out with 8 planes of interleaved scintillating fibers, and a total absorption calorimeter (TASC) with 27 X∘ of lead tungstate (PWO) logs. The primary objectives of the instrument are to measure electron energy spectra from 1 GeV to 20 TeV, to detect gamma-rays above 10 GeV, and to measure the energy spectra of nuclei from protons through iron up to 1,000 TeV. In this paper we describe how the geomagnetic field at the 51.6° inclination orbit of the ISS can be used to allow CALET to measure the rare ultra-heavy (UH) cosmic ray (CR) abundances, which provide important clues for the CR source and acceleration mechanism. The CHD scintillator response is relatively insensitive to energy above minimum ionization, and the angle-dependent rigidity as a function of geomagnetic latitude can be exploited to discriminate particles above this energy threshold. Such events require corrections for trajectory in instrument that can be made with only the top 4 layers of the IMC, which allows for considerably greater geometric acceptance than for events that require passage through the TASC for energy determination. Using this approach CALET will be able to measure UH CR relative abundances over its expected mission with superior statistics to previous space instruments.

  13. Cepas atenuadas de Babesia bovis e Babesia bigemina e de Anaplasma centrale como imunógenos no controle da tristeza parasitária bovina Attenuated strains of Babesia bovis and Babesia bigemina and of Anaplasma centrale as immunogens for tick borne disease control

    Directory of Open Access Journals (Sweden)

    Ana Maria Sastre Sacco

    2001-10-01

    Full Text Available Neste trabalho foram avaliadas cepas atenuadas de Babesia bovis e B. bigemina e Anaplasma centrale como imunógenos a serem utilizados no controle da Tristeza Parasitária Bovina. O processo de imunização demonstrou ser inócuo, imunogênico e eficiente, pelo menos no que diz respeito às babesias, pois protegeu os animais vacinados frente ao desafio com cepas heterólogas virulentas a campo, que provocou doença clínica e morte nos animais do grupo controle. O desafio a campo pelo Anaplasma marginale não se mostrou muito virulento ou patogênico, não sendo possível concluir que a imunização com A. centrale proteja os animais contra anaplasmose.Attenuated strains of Babesia bovis and B. bigemina and a strain of Anaplasma centrale were evaluated as immunogens against tick-borne disease. The immunization process was shown to be inocuous, immunogenic and efficient to protect cattle, at least against the babesias. Vaccinated animals proved to be protected when naturally challenged with heterologous and virulent strains, in contrast to control animals that showed clinical symptoms of the disease and had to be treated. The Anaplasma marginale challenge was not efficient since treatment was not necessary in the control animals, therefore it was not possible to conclude that immunization with A. centrale protected animals against anaplasmosis.

  14. Circumstellar water vapour in M-type AGB stars: Radiative transfer models, abundances and predictions for HIFI

    CERN Document Server

    Maercker, Matthias; Olofsson, Hans; Bergman, Per; Ramstedt, Sofia

    2008-01-01

    Aims: By performing a detailed radiative transfer analysis, we determine fractional abundances of circumstellar H2O in the envelopes around six M-type asymptotic giant branch stars. The models are also used to predict H2O spectral line emission for the upcoming Herschel/HIFI mission. Methods: We use Infrared space observatory long wavelength spectrometer spectra to constrain the circumstellar fractional abundance distribution of ortho-H2O, using a non-local thermal equilibrium, and non-local, radiative transfer code based on the accelerated lambda iteration formalism. The mass-loss rates and kinetic temperature structures for the sample stars are determined through radiative transfer modelling of CO line emission based on the Monte-Carlo method. The density and temperature profiles of the circumstellar dust grains are determined through spectral energy distribution modelling using the publicly available code Dusty. Results: The determined ortho-H2O abundances lie between 1e-4 and 1.5e-3 relative to H2, with t...

  15. Predictions for the abundance and colours of galaxies in high redshift clusters in hierarchical models

    CERN Document Server

    Merson, Alexander I; Abdalla, Filipe B; Gonzalez-Perez, Violeta; Lagos, Claudia del P; Mei, Simona

    2015-01-01

    High redshift galaxy clusters allow us to examine galaxy formation in extreme environments. Here we compile data for $z>1$ galaxy clusters to test the predictions from one of the latest semi-analytical models of galaxy formation. The model gives a good match to the slope and zero-point of the cluster red sequence. The model is able to match the cluster galaxy luminosity function at faint and bright magnitudes, but under-estimates the number of galaxies around the break in the luminosity function. We find that simply assuming a weaker dust attenuation improves the model predictions for the cluster galaxy luminosity function, but worsens the predictions for the red sequence at bright magnitudes. Examination of the properties of the bright cluster galaxies suggests that the default dust attenuation is very large due to these galaxies having large reservoirs of cold gas as well as small radii. We find that matching the luminosity function and colours of high redshift cluster galaxies, whilst remaining consistent ...

  16. Predicting abundance and variability of ice nucleating particles in precipitation at the high-altitude observatory Jungfraujoch

    Science.gov (United States)

    Stopelli, Emiliano; Conen, Franz; Morris, Cindy E.; Herrmann, Erik; Henne, Stephan; Steinbacher, Martin; Alewell, Christine

    2016-07-01

    Nucleation of ice affects the properties of clouds and the formation of precipitation. Quantitative data on how ice nucleating particles (INPs) determine the distribution, occurrence and intensity of precipitation are still scarce. INPs active at -8 °C (INPs-8) were observed for 2 years in precipitation samples at the High-Altitude Research Station Jungfraujoch (Switzerland) at 3580 m a.s.l. Several environmental parameters were scanned for their capability to predict the observed abundance and variability of INPs-8. Those singularly presenting the best correlations with observed number of INPs-8 (residual fraction of water vapour, wind speed, air temperature, number of particles with diameter larger than 0.5 µm, season, and source region of particles) were implemented as potential predictor variables in statistical multiple linear regression models. These models were calibrated with 84 precipitation samples collected during the first year of observations; their predictive power was successively validated on the set of 15 precipitation samples collected during the second year. The model performing best in calibration and validation explains more than 75 % of the whole variability of INPs-8 in precipitation and indicates that a high abundance of INPs-8 is to be expected whenever high wind speed coincides with air masses having experienced little or no precipitation prior to sampling. Such conditions occur during frontal passages, often accompanied by precipitation. Therefore, the circumstances when INPs-8 could be sufficiently abundant to initiate the ice phase in clouds may frequently coincide with meteorological conditions favourable to the onset of precipitation events.

  17. NOAA ESRI Grid - predictions of relative seabird abundance in the New York offshore planning area made by the NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents relative seabird abundance predictions from spatial models developed for the New York offshore spatial planning area. This raster was...

  18. Predicting the abundance of African horse sickness vectors in South Africa using GIS and artificial neural networks

    Directory of Open Access Journals (Sweden)

    Sanet Eksteen

    2011-07-01

    Full Text Available African horse sickness (AHS is a disease that is endemic to sub-Saharan Africa and is caused by a virus potentially transmitted by a number of Culicoides species (Diptera: Ceratopogonidae including Culicoides imicola and Culicoides bolitinos. The strong association between outbreaks of AHS and the occurrence in abundance of these two Culicoides species has enabled researchers to develop models to predict potential outbreaks. A weakness of current models is their inability to determine the relationships that occur amongst the large number of variables potentially influencing the population density of the Culicoides species. It is this limitation that prompted the development of a predictive model with the capacity to make such determinations. The model proposed here combines a geographic information system (GIS with an artificial neural network (ANN. The overall accuracy of the ANN model is 83%, which is similar to other stand-alone GIS models. Our predictive model is made accessible to a wide range of practitioners by the accompanying C. imicola and C. bolitinos distribution maps, which facilitate the visualisation of the model’s predictions. The model also demonstrates how ANN can assist GIS in decision-making, especially where the data sets incorporate uncertainty or if the relationships between the variables are not yet known.

  19. Dynamical 3-Space Predicts Hotter Early Universe: Resolves CMB-BBN 7-Li and 4-He Abundance Anomalies

    Directory of Open Access Journals (Sweden)

    Cahill R. T.

    2010-01-01

    Full Text Available The observed abundances of 7 Li and 4 He are significantly inconsistent with the pre- dictions from Big Bang Nucleosynthesis (BBN when using the CDM cosmolog- ical model together with the value for B h 2 = 0 : 0224 0 : 0009 from WMAP CMB fluctuations, with the value from BBN required to fit observed abundances being 0 : 009 < B h 2 < 0 : 013. The dynamical 3-space theory is shown to predict a 20% hot- ter universe in the radiation-dominated epoch, which then results in a remarkable parameter-free agreement between the BBN and the WMAP value for B h 2 . The dy- namical 3-space also gives a parameter-free fit to the supernova redshift data, and pre- dicts that the flawed CDM model would require = 0 : 73 and M = 0 : 27 to fit the 3-space dynamics Hubble expansion, and independently of the supernova data. These results amount to the discovery of new physics for the early universe that is matched by numerous other successful observational and experimental tests.

  20. 湖北孝感某地蜱虫及人感染蜱媒病原体现状调查%Tick infestation and tick-borne pathogen infection in human and ticks in a military camp and nearby area in Xiaogan, Hubei

    Institute of Scientific and Technical Information of China (English)

    夏先波; 刘曙平; 张琳; 戴缦; 张景辉; 朱淮民

    2015-01-01

    目的 了解驻湖北孝感某部营区蜱虫及蜱媒病原体感染现状,为防治蜱媒病对人群健康危害提供科学依据. 方法 2012年对某营区的仓库及训练场开展蜱虫调查,采集营区警犬饲养员及离营区20 km医院发热待查患者血样、警卫犬体表及营区草地上的蜱虫,分别提取其基因组DNA,PCR方法检测分析测定病原体基因分型. 结果 累计收集患者血110份,将血样混合分组,共7组;警犬饲养员血1份.患者血样检出巴尔通体和肺炎军团菌分别为3组和1组,最大似然估计(maximum likelihoodestinate,MLE)感染率分别为27.77‰(4/110),8.52‰(1/110);警犬饲养员血液检测到巴尔通体.从警犬身上、营区草地上分别采集蜱虫6只、20只.警卫犬体表蜱虫和营区草地蜱虫均检测到巴尔通体和立克次体.营区警犬饲养员及医院发热待查患者血样与营区警犬体表蜱虫检测到的巴尔通体基因型不同,分别为牛巴尔通体(B.bovis USAMRIID-000002),杆菌巴尔通体(B.birtlesii USAMRIID-000020),伊莉萨白巴尔通体(B.elizabethae USAMRIID-000008 or B.grahamii USAMRIID-000026),巴尔通体变形菌(B.grahamii USAMRIID-000026);而警犬体表蜱虫携带的为巴尔通伯格霍夫亚种(Bartonella vinsonii subsp.berkhoffii)基因型Ⅲ.不同来源的样本检测的巴尔通体基因型不同. 结论 该调查点蜱虫易见,蜱媒病原体感染率高,应采取蜱虫防制措施.%Objective To investigate the prevalence of ticks in a military camp,the tick-borne pathogens infection of ticks and human in Xiaogan,Hubei,to provide scientific proof for prevention and treatment of the tick infestation and tick-borne diseases.Methods A total of 110 of human blood samples were collected,Among them,One were sampled from a police dog breeder in military camp,and the other samples were from the out patients who had unknown fever in a hospital apart from 20 km away.Twety-six ticks were sampled,6 came from the guard dogs

  1. A Statistical Model for Predicting the Average Abundance Patterns of Heavier Elements in Metal-Poor Stars

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We have collected nearly all the available observed data of the elements from Ba to Dy in halo and disk stars in the metallicity range -4.0 <[Fe/H]< 0.5.Based on the observed data of Ba and Eu, we evaluated the least-squares regressions of [Ba/Fe] on [Fe/H], and [Eu/H] on [Ba/H]. Assuming that the heavy elements (heavier than Ba) are produced by a combination of the main components of s- and r-processes in metal-poor stars, and choosing Ba and Eu as respective representative elements of the main s- and the main r-processes, a statistical model for predicting the Galactic chemical evolution of the heavy elements is presented. With this model,we calculate the mean abundance trends of the heavy elements La, Ce, Pr, Nd,Sm, and Dy with the metallicity. We compare our results with the observed data at various metallicities, showing that the predicted trends are in good agreement with the observed trends, at least for the metallicity range [Fe/H]≥ -2.5. Finally,we discuss our results and deduce some important information about the Galactic chemical evolution.

  2. [Neurological complications of tick-borne relapsing fever].

    Science.gov (United States)

    Castilla-Guerra, L; Fernandez-Moreno, M C; Vergara-Lopez, S; Merino-Rumin, M; Colmenero-Camacho, M A

    2016-09-16

    Introduccion. La fiebre recurrente transmitida por garrapatas (FRTG) puede producir complicaciones neurologicas. No existen apenas estudios en España sobre el tema. Objetivo. Estudiar la prevalencia y las caracteristicas clinicas de las complicaciones neurologicas de los pacientes con FRTG. Pacientes y metodos. Estudio retrospectivo de los pacientes atendidos con FRTG durante 12 años (2004-2015) en un hospital de una zona rural del sur de España. Resultados. Se incluyeron 75 pacientes, 42 varones (56%), con una edad media de 33 años (rango: 14-72 años). Se observaron picaduras de garrapatas en nueve pacientes (12%). Los sintomas mas frecuentes fueron: fiebre en 64 pacientes (85,3%), cefalea en 41 (54,6%) y vomitos en 26 (34,6%). Se sospecho afectacion meningea en nueve pacientes (12%), de los que tres (4%) tenian signos meningeos en el momento del ingreso. A todos ellos se les realizo una puncion lumbar. Ninguno presento paralisis facial ni otra manifestacion neurologica. Se encontraron alteraciones del liquido cefalorraquideo en los tres pacientes con meningismo. En uno de los casos se visualizo Borrelia en el liquido cefalorraquideo. En los pacientes con afectacion neurologica, el tratamiento utilizado fue penicilina G en un caso y ceftriaxona en dos. Todos los pacientes se recuperaron completamente. Conclusiones. La FRTG es una de las formas menos graves de borreliosis, y menos del 5% de los pacientes presenta complicaciones neurologicas. Sin embargo, los medicos deben saber que Borrelia puede causar meningitis en los sujetos expuestos a garrapatas en regiones endemicas de FRTG.

  3. Tick-Borne Relapsing Fever Spirochetes in the Americas

    Directory of Open Access Journals (Sweden)

    Job E. Lopez

    2016-08-01

    Full Text Available Relapsing fever spirochetes are tick- and louse-borne pathogens that primarily afflict those in impoverished countries. Historically the pathogens have had a significant impact on public health, yet currently they are often overlooked because of the nonspecific display of disease. In this review, we discuss aspects of relapsing fever (RF spirochete pathogenesis including the: (1 clinical manifestation of disease; (2 ability to diagnose pathogen exposure; (3 the pathogen’s life cycle in the tick and mammal; and (4 ecological factors contributing to the maintenance of RF spirochetes in nature.

  4. Study on co-infection of tick-borne pathogens in Ixodes persulcatus in Charles Hilary, Xinjiang Uygur autonomous region%新疆维吾尔自治区夏尔西里自然保护区全沟硬蜱复合感染蜱媒病原研究

    Institute of Scientific and Technical Information of China (English)

    刘晓明; 张桂林; 刘然; 孙响; 郑重; 邱尔臣; 马晓玲

    2015-01-01

    目的 了解新疆维吾尔自治区(新疆)夏尔西里自然保护区全沟硬蜱蜱媒病原复合感染情况.方法 2012年6月至2013年6月在新疆夏尔西里自然保护区采用布旗法采集全沟硬蜱,通过巢式PCR方法对蜱体内莱姆病伯氏疏螺旋体[Borrelia(B.) burgdorferi] 5S~ 23S rRNA基因间隔区、无形体(Anaplasma)16S rRNA基因、斑点热立克次体(Rickettsia) ompA基因、Q热贝氏柯克斯体Coxiella(C.)burneti的com1基因、巴贝西原虫(Babesia)的Nss-rRNA基因进行扩增.结果 204只全沟硬蜱中104只蜱病原检测阳性,阳性率为50.98%,其中伯氏疏螺旋体阳性率为34.31%(n=70),斑点热立克次体阳性率为28.92%(n=59),嗜吞噬细胞无形体阳性率为9.31%(n=19),未检出Q热贝氏柯克斯体和巴贝西原虫.x2检验显示,不同病原感染率差异有统计学意义(x2=38.517,P=0.000).204只蜱中有39只存在复合感染,复合感染率为19.12%(39/204),在病原检测阳性蜱中复合感染率为37.50%(39/104).伯氏疏螺旋体与斑点热立克次体复合感染率为16.18%(n=33);伯氏疏螺旋体与嗜吞噬细胞无形体复合感染率为4.90%(n=10),斑点热立克次体与嗜吞噬细胞无形体复合感染率为2.94%(n=6),3种病原体复合感染率为2.45%(n=5).经x2检验,3种病原混合感染率差异有统计学意义(x2=41.328,P=0.000).结论 新疆夏尔西里自然保护区全沟硬蜱存在伯氏疏螺旋体、嗜吞噬细胞无形体、斑点热立克次体的自然感染,并存在2~3种病原的复合感染.%Objective To study the co-infection of tick-borne pathogens in Ixodes persulcatus collected in Charles Hilary,Xinjiang Uygur autonomous region (Xinjiang).Methods Ticks were collected by flagging in grassy areas in Charles Hilary,Xinjiang from June 2012 to June 2013.The 5S-23S rRNA intergenic region from Borrelia (B.) burgdorferi,16S rRNA gene from Anaplasma,ompA gene from spotted fever group Rickettsia,comI gene from Coxiella (C

  5. Serosurvey of tick-borne pathogens in dogs from urban and rural areas from Parana State, Brazil Avaliação sorológica de patógenos transmitidos por carrapatos em cães urbanos e rurais do estado do Paraná, Brasil

    Directory of Open Access Journals (Sweden)

    Thállitha Samih Wischral Jayme Vieira

    2013-03-01

    Full Text Available Considering the zoonotic potential of tick-borne disease (TBD agents and the fact that dogs may act as sentinels for human infection, the aim of the present study was to determine the seroprevalence of TBD agents and risk factors for exposure in two different canine populations from Parana State, Southern Brazil. A total of 138 dog serum samples from urban (UA (n=68 and rural (RA (n=70 areas were tested with commercial ELISA rapid test for Anaplasma phagocytophilum, Ehrlichia canis and Borrelia burgdorferi antibodies and indirect immunofluorescence assay (IFAT for Babesia vogeli. An overall of 92∕138 (66.7% dogs, being 62∕68 (91.2% from UA and 30∕70 (42.9% from RA, were seropositive for at least one TBD agent. From the total number of dogs, sixty-two were positive for E. canis (44.9%, 19 (13.8% for A. phagocytophilum, and 64 (46.4% for B. vogeli. Anti-B. burgdorferi antibodies were not detected. Dogs from UA showed a higher percentage of tick infestation (p = 0.0135 and were highly associated with seropositivity to E. canis (p = 0.000005, A. phagocytophilum (p = 0.0001, and B. vogeli (p = 0.0012. In summary, the findings indicate that dogs from urban areas present higher potential risk exposure to TBD pathogens than those from rural areas.Considerando o potencial zoonótico das doenças transmitidas por carrapatos (DTCs e que os cães podem atuar como sentinelas para infecções em humanos, os objetivos deste estudo foram determinar a soroprevalência de agentes das DTCs e fatores de risco para a exposição em duas diferentes populações caninas do Estado do Paraná, região Sul do Brasil. Um total de 138 amostras de soro de cães de área urbana (AU (n = 68 e rural (AR (n = 70 foram testadas utilizando um teste de ELISA comercial rápido para detecção de anticorpos contra Anaplasma phagocytophilum, Ehrlichia canis e Borrelia burgdorferi e imunofluorescência indireta (IFI para Babesia vogeli. Um total de 92∕138 (66,7% cães, sendo

  6. Can Airborne Laser Scanning (ALS and Forest Estimates Derived from Satellite Images Be Used to Predict Abundance and Species Richness of Birds and Beetles in Boreal Forest?

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    Eva Lindberg

    2015-04-01

    Full Text Available In managed landscapes, conservation planning requires effective methods to identify high-biodiversity areas. The objective of this study was to evaluate the potential of airborne laser scanning (ALS and forest estimates derived from satellite images extracted at two spatial scales for predicting the stand-scale abundance and species richness of birds and beetles in a managed boreal forest landscape. Multiple regression models based on forest data from a 50-m radius (i.e., corresponding to a homogenous forest stand had better explanatory power than those based on a 200-m radius (i.e., including also parts of adjacent stands. Bird abundance and species richness were best explained by the ALS variables “maximum vegetation height” and “vegetation cover between 0.5 and 3 m” (both positive. Flying beetle abundance and species richness, as well as epigaeic (i.e., ground-living beetle richness were best explained by a model including the ALS variable “maximum vegetation height” (positive and the satellite-derived variable “proportion of pine” (negative. Epigaeic beetle abundance was best explained by “maximum vegetation height” at 50 m (positive and “stem volume” at 200 m (positive. Our results show that forest estimates derived from satellite images and ALS data provide complementary information for explaining forest biodiversity patterns. We conclude that these types of remote sensing data may provide an efficient tool for conservation planning in managed boreal landscapes.

  7. Numerical simulations challenged on the prediction of massive subhalo abundance in galaxy clusters: the case of Abell 2142

    OpenAIRE

    Munari, E.; Grillo, C.; De Lucia, G.; Biviano, A.; Annunziatella, M.; Borgani, S.; Lombardi, M.; Mercurio, A.; Rosati, P.

    2016-01-01

    In this Letter we compare the abundance of member galaxies of a rich, nearby ($z=0.09$) galaxy cluster, Abell 2142, with that of halos of comparable virial mass extracted from sets of state-of-the-art numerical simulations, both collisionless at different resolutions and with the inclusion of baryonic physics in the form of cooling, star formation, and feedback by AGN. We also use two semi-analytical models to account for the presence of orphan galaxies. The photometric and spectroscopic info...

  8. Predicting species distribution and abundance responses to climate change : why it is essential to include biotic interactions across trophic levels

    NARCIS (Netherlands)

    Van der Putten, Wim H.; Macel, Mirka; Visser, Marcel E.

    2010-01-01

    Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species interactions. We review and synthesize literature information on biot

  9. Predicting species distribution and abundance responses to climate change: why it is essential to include biotic interactions across trophic levels

    NARCIS (Netherlands)

    Putten, van der W.H.; Macel, M.; Visser, de M.

    2010-01-01

    Current predictions on species responses to climate change strongly rely on projecting altered environmental conditions on species distributions. However, it is increasingly acknowledged that climate change also influences species interactions. We review and synthesize literature information on biot

  10. Estimation of occupancy, breeding success, and predicted abundance of golden eagles (Aquila chrysaetos) in the Diablo Range, California, 2014

    Science.gov (United States)

    Wiens, J. David; Kolar, Patrick S.; Fuller, Mark R.; Hunt, W. Grainger; Hunt, Teresa

    2015-01-01

    We used a multistate occupancy sampling design to estimate occupancy, breeding success, and abundance of territorial pairs of golden eagles (Aquila chrysaetos) in the Diablo Range, California, in 2014. This method uses the spatial pattern of detections and non-detections over repeated visits to survey sites to estimate probabilities of occupancy and successful reproduction while accounting for imperfect detection of golden eagles and their young during surveys. The estimated probability of detecting territorial pairs of golden eagles and their young was less than 1 and varied with time of the breeding season, as did the probability of correctly classifying a pair’s breeding status. Imperfect detection and breeding classification led to a sizeable difference between the uncorrected, naïve estimate of the proportion of occupied sites where successful reproduction was observed (0.20) and the model-based estimate (0.30). The analysis further indicated a relatively high overall probability of landscape occupancy by pairs of golden eagles (0.67, standard error = 0.06), but that areas with the greatest occupancy and reproductive potential were patchily distributed. We documented a total of 138 territorial pairs of golden eagles during surveys completed in the 2014 breeding season, which represented about one-half of the 280 pairs we estimated to occur in the broader 5,169-square kilometer region sampled. The study results emphasize the importance of accounting for imperfect detection and spatial heterogeneity in studies of site occupancy, breeding success, and abundance of golden eagles.

  11. Species-specific diversity of novel bacterial lineages and differential abundance of predicted pathways for toxic compound degradation in scorpion gut microbiota.

    Science.gov (United States)

    Bolaños, Luis M; Rosenblueth, Mónica; Castillo-Ramírez, Santiago; Figuier-Huttin, Gilles; Martínez-Romero, Esperanza

    2016-05-01

    Scorpions are considered 'living fossils' that have conserved ancestral anatomical features and have adapted to numerous habitats. However, their gut microbiota diversity has not been studied. Here, we characterized the gut microbiota of two scorpion species, Vaejovis smithi and Centruroides limpidus. Our results indicate that scorpion gut microbiota is species-specific and that food deprivation reduces bacterial diversity. 16S rRNA gene phylogenetic analysis revealed novel bacterial lineages showing a low level of sequence identity to any known bacteria. Furthermore, these novel bacterial lineages were each restricted to a different scorpion species. Additionally, our results of the predicted metagenomic profiles revealed a core set of pathways that were highly abundant in both species, and mostly related to amino acid, carbohydrate, vitamin and cofactor metabolism. Notably, the food-deprived V. smithi shotgun metagenome matched almost completely the metabolic features of the prediction. Finally, comparisons among predicted metagenomic profiles showed that toxic compound degradation pathways were more abundant in recently captured C. limpidus scorpions. This study gives a first insight into the scorpion gut microbiota and provides a reference for future studies on the gut microbiota from other arachnid species. PMID:26058415

  12. Use of Contour Maps of Water Depths to Predict Flora and Fauna Abundance in Moist Soil Management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of this project was to develop a technique to quantitatively predict the area of moist soil that would be exposed as a result of a water drawdown of any...

  13. Numerical simulations challenged on the prediction of massive subhalo abundance in galaxy clusters: the case of Abell 2142

    CERN Document Server

    Munari, E; De Lucia, G; Biviano, A; Annunziatella, M; Borgani, S; Lombardi, M; Mercurio, A; Rosati, P

    2016-01-01

    In this Letter we compare the abundance of member galaxies of a rich, nearby ($z=0.09$) galaxy cluster, Abell 2142, with that of halos of comparable virial mass extracted from sets of state-of-the-art numerical simulations, both collisionless at different resolutions and with the inclusion of baryonic physics in the form of cooling, star formation, and feedback by AGN. We also use two semi-analytical models to account for the presence of orphan galaxies. The photometric and spectroscopic information, taken from the Sloan Digital Sky Survey Data Release 12 (SDSS DR12) database, allows us to estimate the stellar velocity dispersion of member galaxies of Abell 2142. This quantity is used as proxy for the total mass of secure cluster members and is properly compared with that of subhalos in simulations. We find that simulated halos have a statistically significant ($\\gtrsim 7$ sigma confidence level) smaller amount of massive (circular velocity above $200\\,{\\rm km\\, s^{-1}}$) subhalos, even before accounting for ...

  14. Numerical Simulations Challenged on the Prediction of Massive Subhalo Abundance in Galaxy Clusters: The Case of Abell 2142

    Science.gov (United States)

    Munari, E.; Grillo, C.; De Lucia, G.; Biviano, A.; Annunziatella, M.; Borgani, S.; Lombardi, M.; Mercurio, A.; Rosati, P.

    2016-08-01

    In this Letter we compare the abundance of the member galaxies of a rich, nearby (z = 0.09) galaxy cluster, Abell 2142, with that of halos of comparable virial mass extracted from sets of state-of-the-art numerical simulations, both collisionless at different resolutions and with the inclusion of baryonic physics in the form of cooling, star formation, and feedback by active galactic nuclei. We also use two semi-analytical models to account for the presence of orphan galaxies. The photometric and spectroscopic information, taken from the Sloan Digital Sky Survey Data Release 12 database, allows us to estimate the stellar velocity dispersion of member galaxies of Abell 2142. This quantity is used as proxy for the total mass of secure cluster members and is properly compared with that of subhalos in simulations. We find that simulated halos have a statistically significant (≳ 7 sigma confidence level) smaller amount of massive (circular velocity above 200 {km} {{{s}}}-1) subhalos, even before accounting for the possible incompleteness of observations. These results corroborate the findings from a recent strong lensing study of the Hubble Frontier Fields galaxy cluster MACS J0416 and suggest that the observed difference is already present at the level of dark matter (DM) subhalos and is not solved by introducing baryonic physics. A deeper understanding of this discrepancy between observations and simulations will provide valuable insights into the impact of the physical properties of DM particles and the effect of baryons on the formation and evolution of cosmological structures.

  15. Can functional gene abundance predict N-fluxes? Examples from a well-studied hydrological flow path in a forested watershed in SW China

    Science.gov (United States)

    Liu, Binbin; Muzammil, Bushra; Dörsch, Peter; Zhu, Jing; Mulder, Jan; Frostegård, Åsa

    2014-05-01

    Edaphic, climatic and management factors shape soil microbial communities taxonomically and functionally, resulting in spatial separation of nitrogen (N) oxidation and reduction processes along hydrological flowpaths. In a recent study, we investigated N-cycling processes and N2O emissions along a mesic hillslope (HS) and a hydrologically connected groundwater discharge zone (GDZ) in a forested headwater catchment dominated by acid soils (pH 4.0 - 4.5) in subtropical China (Chongqing). The watershed receives 50 kg N ha-1 a-1 through atmogenic deposition (2/3 as ammonium), most of which is removed before discharge. Surprisingly, N2O emissions were found to be greatest on the well-drained HS, whereas a drop of NO3- concentrations along the flow path indicated that N removal was highest in the moist GDZ. Nitrification was assumed to be none-limiting as the total flux of NO3- leaving the hill slope soils roughly equalled the input of NH4+. To understand watershed N-cycling and removal in more detail, we studied the abundance of functional genes involved in ammonium oxidation (amoA of AOB and AOA), nitrite oxidation (nxrB) and denitrification (nirK, nirS, nosZ) in top soils from 8 locations along the flow path spanning from the hilltop to the outlet of the GDZ. 16S rRNA gene abundance was assessed as a general marker for bacterial abundance. All genes showed highest abundance per gram soil in the heavily disturbed GDZ (formerly cultivated terraces), despite lower soil organic carbon content (1-4% w/w as opposed to 10-20% w/w in HS topsoil) and periodically stagnant conditions due to high water tables after monsoonal rainfalls. Ratios of nosZ/nirS+nirK, commonly used to predict denitrification product stoichiometry (N2O/N2), yielded counterintuitive results with higher values for HS than for GDZ. However, comparing nir gene with 16S rRNA gene abundance revealed that denitrifiers accounted for up to 10% of the bacterial community in the GDZ soils whereas this value was

  16. Abundance of early functional HIV-specific CD8+ T cells does not predict AIDS-free survival time.

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    Ingrid M M Schellens

    Full Text Available BACKGROUND: T-cell immunity is thought to play an important role in controlling HIV infection, and is a main target for HIV vaccine development. HIV-specific central memory CD8(+ and CD4(+ T cells producing IFNgamma and IL-2 have been associated with control of viremia and are therefore hypothesized to be truly protective and determine subsequent clinical outcome. However, the cause-effect relationship between HIV-specific cellular immunity and disease progression is unknown. We investigated in a large prospective cohort study involving 96 individuals of the Amsterdam Cohort Studies with a known date of seroconversion whether the presence of cytokine-producing HIV-specific CD8(+ T cells early in infection was associated with AIDS-free survival time. METHODS AND FINDINGS: The number and percentage of IFNgamma and IL-2 producing CD8(+ T cells was measured after in vitro stimulation with an overlapping Gag-peptide pool in T cells sampled approximately one year after seroconversion. Kaplan-Meier survival analysis and Cox proportional hazard models showed that frequencies of cytokine-producing Gag-specific CD8(+ T cells (IFNgamma, IL-2 or both shortly after seroconversion were neither associated with time to AIDS nor with the rate of CD4(+ T-cell decline. CONCLUSIONS: These data show that high numbers of functional HIV-specific CD8(+ T cells can be found early in HIV infection, irrespective of subsequent clinical outcome. The fact that both progressors and long-term non-progressors have abundant T cell immunity of the specificity associated with low viral load shortly after seroconversion suggests that the more rapid loss of T cell immunity observed in progressors may be a consequence rather than a cause of disease progression.

  17. Like will to like: abundances of closely related species can predict susceptibility to intestinal colonization by pathogenic and commensal bacteria.

    Directory of Open Access Journals (Sweden)

    Bärbel Stecher

    2010-01-01

    Full Text Available The intestinal ecosystem is formed by a complex, yet highly characteristic microbial community. The parameters defining whether this community permits invasion of a new bacterial species are unclear. In particular, inhibition of enteropathogen infection by the gut microbiota ( = colonization resistance is poorly understood. To analyze the mechanisms of microbiota-mediated protection from Salmonella enterica induced enterocolitis, we used a mouse infection model and large scale high-throughput pyrosequencing. In contrast to conventional mice (CON, mice with a gut microbiota of low complexity (LCM were highly susceptible to S. enterica induced colonization and enterocolitis. Colonization resistance was partially restored in LCM-animals by co-housing with conventional mice for 21 days (LCM(con21. 16S rRNA sequence analysis comparing LCM, LCM(con21 and CON gut microbiota revealed that gut microbiota complexity increased upon conventionalization and correlated with increased resistance to S. enterica infection. Comparative microbiota analysis of mice with varying degrees of colonization resistance allowed us to identify intestinal ecosystem characteristics associated with susceptibility to S. enterica infection. Moreover, this system enabled us to gain further insights into the general principles of gut ecosystem invasion by non-pathogenic, commensal bacteria. Mice harboring high commensal E. coli densities were more susceptible to S. enterica induced gut inflammation. Similarly, mice with high titers of Lactobacilli were more efficiently colonized by a commensal Lactobacillus reuteri(RR strain after oral inoculation. Upon examination of 16S rRNA sequence data from 9 CON mice we found that closely related phylotypes generally display significantly correlated abundances (co-occurrence, more so than distantly related phylotypes. Thus, in essence, the presence of closely related species can increase the chance of invasion of newly incoming species into

  18. All together now? Sensitivity, dynamics, and predictability of planktonic foraminiferal species abundance versus community structure across Plio-Pleistocene glacial-interglacial cycles

    Science.gov (United States)

    Hull, P. M.; Norris, R. D.; Sexton, P.

    2012-12-01

    Most studies to date of biospheric sensitivity to global change have focused on understanding the sensitivity of modern species and communities to recent or experimental environmental change. However, it is unclear how to scale these results towards predicting the response of the biosphere to ongoing global change given that i) similar species often respond individualistically the same perturbation, ii) biotic response often scales nonlinearly with the size and/or duration of environmental change, and iii) many terrestrial and marine community types known from the recent past lack modern analogs. In this context, marine microfossils from deep sea sediments hold enormous promise for furthering our understanding of biotic sensitivity as they capture temporally expanded records of paleoceanographic and biotic response across a range climatic regimes (e.g., icehouse versus greenhouse climates), disturbance types (e.g., from background climate oscillations to mass extinctions), and habitats (e.g., low vs. high latitudes, upwelling vs. gyre ecosystems, etc). Here we use the repeated glacial-interglacial cycles and longer term trend of intensifying Northern Hemisphere glaciation from the Pliocene-Pleistocene to examine issues related to the sensitivity of planktonic foraminiferal species and communities to global change in an icehouse world. More specifically, we quantify the sensitivity and predictability of changes in planktonic foraminiferal species abundance (species specific mass accumulation rates) and community structure (dissimilarity indices and community classification) to glacial-interglacial cycles in the Plio-Pleistocene in two Atlantic sites (ODP Sites 999 and 662). We first examine whether the sensitivity of species and communities to glacial-interglacial cycles in the early Pliocene (~5-3 million years ago) is predictive of i) their sensitivity to the intensification of Northern Hemisphere glaciation (~3-2 million years ago), or ii) their sensitivity to

  19. Planetary nebulae abundances and stellar evolution

    OpenAIRE

    Pottasch, S. R.; Bernard-Salas, J.

    2006-01-01

    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these gradients at the distance of the Sun from the center are exactly the solar abundance. Sulfur is the exception to this; the reason for this...

  20. Abundances in galaxies

    International Nuclear Information System (INIS)

    Standard (or mildly inhomogeneous) Big Bang nucleosynthesis theory is well confirmed by abundance measurements of light elements up to 7Li and the resulting upper limit to the number of neutrino families confirmed in accelerator experiments. Extreme inhomogeneous models with a closure density in form of baryons seem to be ruled out and there is no evidence for a cosmic 'floor' to 9Be or heavier elements predicted in some versions of those models. Galaxies show a correlation between luminous mass and abundance of carbon and heavier elements, usually attributed to escape of hot gas from shallow potential wells. Uncertainties include the role of dark matter and biparametric behaviour of ellipticals. Spirals have radial gradients which may arise from a variety of causes. In our own Galaxy one can distinguish three stellar populations - disk, halo and bulge - characterised by differing metallicity distribution functions. Differential abundance effects are found among different elements in stars as a function of metallicity and presumably age, notably in the ratio of oxygen and α-particle elements to iron. These may eventually be exploitable to set a time scale for the formation of the halo, bulge and disk. (orig.)

  1. Current temporal trends in moth abundance are counter to predicted effects of climate change in an assemblage of subarctic forest moths.

    Science.gov (United States)

    Hunter, Mark D; Kozlov, Mikhail V; Itämies, Juhani; Pulliainen, Erkki; Bäck, Jaana; Kyrö, Ella-Maria; Niemelä, Pekka

    2014-06-01

    Changes in climate are influencing the distribution and abundance of the world's biota, with significant consequences for biological diversity and ecosystem processes. Recent work has raised concern that populations of moths and butterflies (Lepidoptera) may be particularly susceptible to population declines under environmental change. Moreover, effects of climate change may be especially pronounced in high latitude ecosystems. Here, we examine population dynamics in an assemblage of subarctic forest moths in Finnish Lapland to assess current trajectories of population change. Moth counts were made continuously over a period of 32 years using light traps. From 456 species recorded, 80 were sufficiently abundant for detailed analyses of their population dynamics. Climate records indicated rapid increases in temperature and winter precipitation at our study site during the sampling period. However, 90% of moth populations were stable (57%) or increasing (33%) over the same period of study. Nonetheless, current population trends do not appear to reflect positive responses to climate change. Rather, time-series models illustrated that the per capita rates of change of moth species were more frequently associated negatively than positively with climate change variables, even as their populations were increasing. For example, the per capita rates of change of 35% of microlepidoptera were associated negatively with climate change variables. Moth life-history traits were not generally strong predictors of current population change or associations with climate change variables. However, 60% of moth species that fed as larvae on resources other than living vascular plants (e.g. litter, lichen, mosses) were associated negatively with climate change variables in time-series models, suggesting that such species may be particularly vulnerable to climate change. Overall, populations of subarctic forest moths in Finland are performing better than expected, and their populations

  2. High abundance of Serine/Threonine-rich regions predicted to be hyper-O-glycosylated in the secretory proteins coded by eight fungal genomes

    Directory of Open Access Journals (Sweden)

    González Mario

    2012-09-01

    Full Text Available Abstract Background O-glycosylation of secretory proteins has been found to be an important factor in fungal biology and virulence. It consists in the addition of short glycosidic chains to Ser or Thr residues in the protein backbone via O-glycosidic bonds. Secretory proteins in fungi frequently display Ser/Thr rich regions that could be sites of extensive O-glycosylation. We have analyzed in silico the complete sets of putatively secretory proteins coded by eight fungal genomes (Botrytis cinerea, Magnaporthe grisea, Sclerotinia sclerotiorum, Ustilago maydis, Aspergillus nidulans, Neurospora crassa, Trichoderma reesei, and Saccharomyces cerevisiae in search of Ser/Thr-rich regions as well as regions predicted to be highly O-glycosylated by NetOGlyc (http://www.cbs.dtu.dk. Results By comparison with experimental data, NetOGlyc was found to overestimate the number of O-glycosylation sites in fungi by a factor of 1.5, but to be quite reliable in the prediction of highly O-glycosylated regions. About half of secretory proteins have at least one Ser/Thr-rich region, with a Ser/Thr content of at least 40% over an average length of 40 amino acids. Most secretory proteins in filamentous fungi were predicted to be O-glycosylated, sometimes in dozens or even hundreds of sites. Residues predicted to be O-glycosylated have a tendency to be grouped together forming hyper-O-glycosylated regions of varying length. Conclusions About one fourth of secretory fungal proteins were predicted to have at least one hyper-O-glycosylated region, which consists of 45 amino acids on average and displays at least one O-glycosylated Ser or Thr every four residues. These putative highly O-glycosylated regions can be found anywhere along the proteins but have a slight tendency to be at either one of the two ends.

  3. Known and potential ticks and tick-borne pathogens of Micronesia

    Directory of Open Access Journals (Sweden)

    Vander Velde, N.

    2013-04-01

    Full Text Available Ticks have long been known to be the vectors of diseases, to both humans and animals. Yet very little work has been done regarding tick species found in Micronesia, and much of that is now decades old. Many parts of Micronesia have long undergone considerable change by outside influences and hence the natural and social environments have undergone major upheavals. Ticks as vectors of veterinary disease have long been documented in Micronesia, but ticks connected with human disease are often presumed not to exist. Hence another look would seem justified. This paper provides an initial review of information on tick species reported from Micronesia. Some diseases that such ticks transmit are presented, along with some hypothetical consideration of other diseases potentially associated with ticks of Micronesia. As this information on the ecology of ticks in Micronesia and the environments and circumstances allowing for the possibility of transmission of disease to humans come together, there emerges an intriguing picture of an often-overlooked part of the environment in which humans live in Micronesia.

  4. Use of nuclear techniques in the study of some tick borne haemoparasitic diseases

    International Nuclear Information System (INIS)

    During the period of the research programme on babesiosis at Long Pocket Laboratories, work has concentrated on three areas: (i) improvements to existing live vaccines; (ii) identification, isolation and characterization of protective antigens for potential use in synthetic vaccines; and (iii) development of more specific and sensitive serodiagnostic tests. The use of irradiation to obtain stable, avirulent Babesia bovis organisms suitable for use as live immunogens was successful with a number of strains. However, attempts to induce changes in B. bigemina by irradiation were much less successful. Three antigenic fractions were identified in B. bovis which induced strong protective responses. Further purification using affinity chromatography with monoclonal antibodies resulted in two antigens being purified. One of these was sequenced and, using synthetic oligonucleotide probes, the cDNA encoding for that antigen was isolated. Some of these protective antigens are common to more than one species of Babesia and this cross-protective status was exploited with experimental dead vaccines. Enzyme linked immunosorbent assay (ELISA) and Radioimmunoassay (RIA) techniques were developed for the diagnosis of both B. bovis and B. bigemina antibodies. Whilst the RIA technique is more sensitive than the ELISA, the latter has the advantage of stability and relative safety of the detection system. Long term single infections can be diagnosed with these systems and they are ideal for detecting low levels of antibody. Further development of the B. bigemina ELISA is necessary, especialy as the antigen is quite labile and must be freshly prepared. This is the one disadvantage in an otherwise highly sensitive and specific test system. (author). 21 refs, 3 figs, 2 tabs

  5. Induction and suppression of tick cell antiviral RNAi responses by tick-borne flaviviruses

    NARCIS (Netherlands)

    Schnettler, E.; Tykalova, H.; Watson, M.; Sharma, M.; Sterken, M.G.; Obbard, D.J.; Lewis, S.H.; McFarlane, M.; Bell-Sakyi, L.; Barry, G.; Weisheit, S.; Best, S.M.; Kuhn, R.J.; Pijlman, G.P.; Chase-Topping, M.E.; Gould, E.A.; Grubhoffer, L.; Fazakerley, J.K.; Kohl, A.

    2014-01-01

    Arboviruses are transmitted by distantly related arthropod vectors such as mosquitoes (class Insecta) and ticks (class Arachnida). RNA interference (RNAi) is the major antiviral mechanism in arthropods against arboviruses. Unlike in mosquitoes, tick antiviral RNAi is not understood, although this in

  6. Nucleic acid probes as a diagnostic method for tick-borne hemoparasites of veterinary importance.

    Science.gov (United States)

    Figueroa, J V; Buening, G M

    1995-03-01

    An increased number of articles on the use of nucleic acid-based hybridization techniques for diagnostic purposes have been recently published. This article reviews nucleic acid-based hybridization as an assay to detect hemoparasite infections of economic relevance in veterinary medicine. By using recombinant DNA techniques, selected clones containing inserts of Anaplasma, Babesia, Cowdria or Theileria genomic DNA sequences have been obtained, and they are now available to be utilized as specific, highly sensitive DNA or RNA probes to detect the presence of the hemoparasite DNA in an infected animal. Either in an isotopic or non-isotopic detection system, probes have allowed scientists to test for--originally in samples collected from experimentally infected animals and later in samples collected in the field--the presence of hemoparasites during the prepatent, patent, convalescent, and chronic periods of the infection in the host. Nucleic acid probes have given researchers the opportunity to carry out genomic analysis of parasite DNA to differentiate hemoparasite species and to identify genetically distinct populations among and within isolates, strains and clonal populations. Prevalence of parasite infection in the tick vector can now be accomplished more specifically with the nucleic acid probes. Lately, with the advent of the polymerase chain reaction technique, small numbers of hemoparasites can be positively identified in the vertebrate host and tick vector. These techniques can be used to assess the veterinary epidemiological situation in a particular geographical region for the planning of control measures. PMID:7597795

  7. Multiple independent transmission cycles of a tick-borne pathogen within a local host community.

    Science.gov (United States)

    Jacquot, Maude; Abrial, David; Gasqui, Patrick; Bord, Severine; Marsot, Maud; Masseglia, Sébastien; Pion, Angélique; Poux, Valérie; Zilliox, Laurence; Chapuis, Jean-Louis; Vourc'h, Gwenaël; Bailly, Xavier

    2016-01-01

    Many pathogens are maintained by multiple host species and involve multiple strains with potentially different phenotypic characteristics. Disentangling transmission patterns in such systems is often challenging, yet investigating how different host species contribute to transmission is crucial to properly assess and manage disease risk. We aim to reveal transmission cycles of bacteria within the Borrelia burgdorferi species complex, which include Lyme disease agents. We characterized Borrelia genotypes found in 488 infected Ixodes ricinus nymphs collected in the Sénart Forest located near Paris (France). These genotypes were compared to those observed in three sympatric species of small mammals and network analyses reveal four independent transmission cycles. Statistical modelling shows that two cycles involving chipmunks, an introduced species, and non-sampled host species such as birds, are responsible for the majority of tick infections. In contrast, the cycle involving native bank voles only accounts for a small proportion of infected ticks. Genotypes associated with the two primary transmission cycles were isolated from Lyme disease patients, confirming the epidemiological threat posed by these strains. Our work demonstrates that combining high-throughput sequence typing with networks tools and statistical modeling is a promising approach for characterizing transmission cycles of multi-host pathogens in complex ecological settings. PMID:27498685

  8. The epidemiology of tick-borne relapsing fever in Bijar County, North-Western Iran

    Institute of Scientific and Technical Information of China (English)

    Hamid Kassiri; Ali Kasiri; Kobra Dostifar; Masoud Lotfi

    2014-01-01

    To explain the demographic and epidemiological aspects of found cases of illness in theBijar County, north-westernIran, in the year of2007-2008. Methods:In this descriptive study population included all febrile cases referring to health services centers ofBijarCounty.A confirmed case was defined as an individual who had both febrile disease and detection ofBorrelia in a peripheral blood smear byWright-Giemsa using dark-field microscop.Each patient was asked to fulfill a questionnaire including clinical and epidemiological features and demographic information ofTBRF. Results:During the year of2007-2008,11 cases have been reported fromBijarCounty.There were5 cases(45.4%) of the patients younger than10 years,6 cases(54.5%) were10-19 years old. Of the patients,63.6% occurred in summer and27.3% in spring.All cases developed during the months ofMay toOctober.Fever and chills, the most common symptoms, occured in all patients. Most(54.5%) of the cases were students and the remaining were children.Approximately72.7% of the patients were keeping cattle and sheep near or inside their homes.

  9. Emerging Tick-borne Rickettsia and Ehrlichia at Joint Base Langley-Eustis, Fort Eustis, Virginia.

    Science.gov (United States)

    Miller, Melissa K; Jiang, Ju; Truong, Melissa; Yarina, Tamasin; Evans, Holly; Christensen, Timothy P; Richards, Allen L

    2016-01-01

    Four species of ticks known to parasitize humans (Amblyomma americanum (lone star tick), Dermacentor variabilis (American dog tick), Amblyomma maculatum (Gulf Coast tick), and Ixodes scapularis (black-legged tick)) were collected at Joint Base Langley-Eustis, Fort Eustis, Virginia during 2009. These ticks were tested individually (adults and nymphs) and in pools of 15 (larvae) for pathogens of public health importance within the genera: Rickettsia, Borrelia, and Ehrlichia, by quantitative real-time polymerase chain reaction (qPCR) assays and, where appropriate, multilocus sequence typing (MLST). Of the 340 A americanum ticks tested, a minimum of 65 (19%), 4 (1%), 4 (1%), and one (<1%) were positive for Rickettsia amblyommii, B lonestari, E ewingii and E chaffeensis, respectively. One of 2 (50%) A maculatum ticks collected was found to be positive for R parkeri by MLST and qPCR analyses. All 33 D variabilis ticks were negative for evidence of rickettsial infections. Likewise, no pathogenic organisms were detected from the single Ixodes scapularis tick collected. Pathogenic rickettsiae and ehrlichiae are likely emerging and cause under-recognized diseases, which threaten people who live, work, train, or otherwise engage in outdoor activities at, or in the vicinity of, Fort Eustis, Virginia. PMID:27613206

  10. MODERN PARASITIC SYSTEMS OF TICK-BORNE INFECTIONS IN LVIV OBLAST

    Directory of Open Access Journals (Sweden)

    Fedoruk V.,

    2012-12-01

    Full Text Available The results of the study of parasitic systems of associated with ixodal ticks infections in the Lviv region for the period 2007-2012 were analyzed. The main vectors and reservoirs, carrying at the present stage a high loimopotential of natural dangerous diseases foci were submitted.

  11. Sir Arnold Theiler and the discovery of anaplasmosis : a centennial perspective : tick-borne diseases

    Directory of Open Access Journals (Sweden)

    G.H. Palmer

    2009-09-01

    Full Text Available Sir Arnold Theiler's research in 1908/09 led to the discovery of the first rickettsial pathogen, Anaplasma marginale, and set the stage for his development and implementation of an effective live vaccine based on a less virulent strain, A. marginale ss. centrale. His 1910 report, describing A. marginale, is among the classic monographs in infectious disease research, presenting not only observations in exacting detail but also highlighting the deductive reasoning leading to association of a new pathogen with a specific disease. With a centennial perspective and both conceptual frameworks and molecular tools unimaginable in Theiler's time, the significance of several observations in the original report - cyclic bacteremia, strain superinfection, and taxonomic position - is now clear and highlight the broad applicability of key principles of pathogen biology.

  12. [Tick-borne encephalitis (TBE) and TBE-vaccination in Austria: Update 2014].

    Science.gov (United States)

    Kunze, Ursula; Böhm, Gabriela

    2015-07-01

    TBE is a public health problem well under control in Austria because of a mass vaccination programme. There have been 50-100 registered cases per year for many years, the vaccination rate of the population is currently 85 %. Special attention has to be given to the "older" generation 40 plus as this is the segment of the population where the majority of cases are observed annually. In comparison of the counties, Tyrol and Upper Austria finished first and second after a long time when Styria and Carynthia had observed most of the cases. For TBE applies the same as for Tetanus, namely the principle of disease control or disease elimination: The virus cannot be eliminated and vaccination provides individual protection. The both available TBE vaccines have proven to be very effective with an effectivity of 96-99 %, also when given irregular vaccinations the protection rate is still very high (>90 %). More than 4000 prevented cases between 2000 and 2011 prove this impressively.

  13. Genetic Diversity of Tick-Borne Rickettsial Pathogens; Insights Gained from Distant Strains

    Directory of Open Access Journals (Sweden)

    Sebastián Aguilar Pierlé

    2014-01-01

    Full Text Available The ability to capture genetic variation with unprecedented resolution improves our understanding of bacterial populations and their ability to cause disease. The goal of the pathogenomics era is to define genetic diversity that results in disease. Despite the economic losses caused by vector-borne bacteria in the Order Rickettsiales, little is known about the genetic variants responsible for observed phenotypes. The tick-transmitted rickettsial pathogen Anaplasma marginale infects cattle in tropical and subtropical regions worldwide, including Australia. Genomic analysis of North American A. marginale strains reveals a closed core genome defined by high levels of Single Nucleotide Polymorphisms (SNPs. Here we report the first genome sequences and comparative analysis for Australian strains that differ in virulence and transmissibility. A list of genetic differences that segregate with phenotype was evaluated for the ability to distinguish the attenuated strain from virulent field strains. Phylogenetic analyses of the Australian strains revealed a marked evolutionary distance from all previously sequenced strains. SNP analysis showed a strikingly reduced genetic diversity between these strains, with the smallest number of SNPs detected between any two A. marginale strains. The low diversity between these phenotypically distinct bacteria presents a unique opportunity to identify the genetic determinants of virulence and transmission.

  14. Known and potential ticks and tick-borne pathogens of Micronesia

    OpenAIRE

    Vander Velde, N.; Vander Velde, B.

    2013-01-01

    Ticks have long been known to be the vectors of diseases, to both humans and animals. Yet very little work has been done regarding tick species found in Micronesia, and much of that is now decades old. Many parts of Micronesia have long undergone considerable change by outside influences and hence the natural and social environments have undergone major upheavals. Ticks as vectors of veterinary disease have long been documented in Micronesia, but ticks connected with human disease are often p...

  15. Evolution and molecular characterization of tick-borne Anaplasmataceae and implications for pathogen diagnostics and control.

    OpenAIRE

    Cabezas Cruz, Alejandro

    2014-01-01

    Esta tesis se concentra en la caracterización molecular de patógenos transmitidos por garrapatas, los cuales han cobrado una gran importancia en los últimos años debido a su impacto en la economía agropecuaria, y en la salub pública de países tanto desarrollados como en vía de desarrollo (Perez y col., 2006; Rikihisa, 2010; Aubry y Geale, 2011). Particularmente la tesis usa una combinación de herramientas moleculares, bioinformaticas y filogenéticas para estudiar la variación genética de dos...

  16. Comparative genomics reveals multiple pathways to mutualism for tick-borne pathogens

    OpenAIRE

    Lockwood, Svetlana; Brayton, Kelly A.; Broschat, Shira L.

    2016-01-01

    Background Multiple important human and livestock pathogens employ ticks as their primary host vectors. It is not currently known whether this means of infecting a host arose once or many times during evolution. Results In order to address this question, we conducted a comparative genomics analysis on a set of bacterial pathogens from seven genera – Borrelia, Rickettsia, Anaplasma, Ehrlichia, Francisella, Coxiella, and Bartonella, including species from three different host vectors – ticks, l...

  17. High-throughput screening of tick-borne pathogens in Europe

    DEFF Research Database (Denmark)

    Michelet, Lorraine; Delannoy, Sabine; Devillers, Elodie;

    2014-01-01

    was conducted on 7050 Ixodes ricinus nymphs collected from France, Denmark, and the Netherlands using a powerful new high-throughput approach. This advanced methodology permitted the simultaneous detection of 25 bacterial, and 12 parasitic species (including; Borrelia, Anaplasma, Ehrlichia, Rickettsia......, Bartonella, Candidatus Neoehrlichia, Coxiella, Francisella, Babesia, and Theileria genus) across 94 samples. We successfully determined the prevalence of expected (Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia helvetica, Candidatus Neoehrlichia mikurensis, Babesia divergens, Babesia...

  18. Chimeric flaviviruses: novel vaccines against dengue fever, tick-borne encephalitis, and Japanese encephalitis.

    Science.gov (United States)

    Lai, Ching-Juh; Monath, Thomas P

    2003-01-01

    Many arthropod-borne flaviviruses are important human pathogens responsible for diverse illnesses, including YF, JE, TBE, and dengue. Live, attenuated vaccines have afforded the most effective and economical means of prevention and control, as illustrated by YF 17D and JE SA14-14-2 vaccines. Recent advances in recombinant DNA technology have made it possible to explore a novel approach for developing live attenuated flavivirus vaccines against other flaviviruses. Full-length cDNA clones allow construction of infectious virus bearing attenuating mutations or deletions incorporated in the viral genome. It is also possible to create chimeric flaviviruses in which the structural protein genes for the target antigens of a flavivirus are replaced by the corresponding genes of another flavivirus. By combining these molecular techniques, the DNA sequences of DEN4 strain 814669, DEN2 PDK-53 candidate vaccine and YF 17D vaccine have been used as the genetic backbone to construct chimeric flaviviruses with the required attenuation phenotype and expression of the target antigens. Encouraging results from preclinical and clinical studies have shown that several chimeric flavivirus vaccines have the safety profile and satisfactory immunogenicity and protective efficacy to warrant further evaluation in humans. The chimeric flavivirus strategy has led to the rapid development of novel live-attenuated vaccines against dengue, TBE, JE, and West Nile viruses. PMID:14714441

  19. Integrated tick and tick-borne disease control trials in crossbred dairy cattle in Malawi

    DEFF Research Database (Denmark)

    Tjørnehøj, Kirsten; Whiteland, A. P.; Mfitilodze, M. W.;

    1996-01-01

    Crossbred dairy heifers on a farm in an East Coast fever (ECF) endemic area in Malawi were immunised against Theileria parva, Anaplasma spp., Babesia bigemina, Babesia bovis and Cowdria ruminantium. They were treated at infrequent intervals with chlorfenvinphos to limit infestation with adult tic...

  20. Chlorine Abundances in Cool Stars

    CERN Document Server

    Maas, Z G; Hinkle, K

    2016-01-01

    Chlorine abundances are reported in 15 evolved giants and one M dwarf in the solar neighborhood. The Cl abundance was measured using the vibration-rotation 1-0 P8 line of H$^{35}$Cl at 3.69851 $\\mu$m. The high resolution L-band spectra were observed using the Phoenix infrared spectrometer on the Kitt Peak Mayall 4m telescope. The average [$^{35}$Cl/Fe] abundance in stars with --0.72$<$[Fe/H]$<$0.20 is [$^{35}$Cl/Fe]=(--0.10$\\pm$0.15) dex. The mean difference between the [$^{35}$Cl/Fe] ratios measured in our stars and chemical evolution model values is (0.16$\\pm$0.15) dex. The [$^{35}$Cl/Ca] ratio has an offset of $\\sim$0.35 dex above model predictions suggesting chemical evolution models are under producing Cl at the high metallicity range. Abundances of C, N, O, Si, and Ca were also measured in our spectral region and are consistent with F and G dwarfs. The Cl versus O abundances from our sample match Cl abundances measured in planetary nebula and \\ion{H}{2} regions. In one star where both H$^{35}$Cl a...

  1. Substrate prediction of Ixodes ricinus salivary lipocalins differentially expressed during Borrelia afzelii infection

    Science.gov (United States)

    Valdés, James J.; Cabezas-Cruz, Alejandro; Sima, Radek; Butterill, Philip T.; Růžek, Daniel; Nuttall, Patricia A.

    2016-01-01

    Evolution has provided ticks with an arsenal of bioactive saliva molecules that counteract host defense mechanisms. This salivary pharmacopoeia enables blood-feeding while enabling pathogen transmission. High-throughput sequencing of tick salivary glands has thus become a major focus, revealing large expansion within protein encoding gene families. Among these are lipocalins, ubiquitous barrel-shaped proteins that sequester small, typically hydrophobic molecules. This study was initiated by mining the Ixodes ricinus salivary gland transcriptome for specific, uncharacterized lipocalins: three were identified. Differential expression of these I. ricinus lipocalins during feeding at distinct developmental stages and in response to Borrelia afzelii infection suggests a role in transmission of this Lyme disease spirochete. A phylogenetic analysis using 803 sequences places the three I. ricinus lipocalins with tick lipocalins that sequester monoamines, leukotrienes and fatty acids. Both structural analysis and biophysical simulations generated robust predictions showing these I. ricinus lipocalins have the potential to bind monoamines similar to other tick species previously reported. The multidisciplinary approach employed in this study characterized unique lipocalins that play a role in tick blood-feeding and transmission of the most important tick-borne pathogen in North America and Eurasia. PMID:27584086

  2. Prediction

    CERN Document Server

    Sornette, Didier

    2010-01-01

    This chapter first presents a rather personal view of some different aspects of predictability, going in crescendo from simple linear systems to high-dimensional nonlinear systems with stochastic forcing, which exhibit emergent properties such as phase transitions and regime shifts. Then, a detailed correspondence between the phenomenology of earthquakes, financial crashes and epileptic seizures is offered. The presented statistical evidence provides the substance of a general phase diagram for understanding the many facets of the spatio-temporal organization of these systems. A key insight is to organize the evidence and mechanisms in terms of two summarizing measures: (i) amplitude of disorder or heterogeneity in the system and (ii) level of coupling or interaction strength among the system's components. On the basis of the recently identified remarkable correspondence between earthquakes and seizures, we present detailed information on a class of stochastic point processes that has been found to be particu...

  3. Climate and local abundance in freshwater fishes

    OpenAIRE

    Knouft, Jason H; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide va...

  4. Precision Chemical Abundance Measurements

    DEFF Research Database (Denmark)

    Yong, David; Grundahl, Frank; Meléndez, Jorge;

    2012-01-01

    This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate that the ob......This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate...... that the observed abundance dispersion exceeds the measurement uncertainties and that many pairs of elements show significant correlations when plotting [X1/H] vs. [X2/H]. Our tentative conclusions are that either NGC 6752 is not chemically homogeneous at the ~=0.03 dex level or the abundance variations...

  5. Homology Modeling and Conformational Epitope Prediction of Envelope Protein of Alkhumra Haemorrhagic Fever Virus

    Directory of Open Access Journals (Sweden)

    Naghmeh Poorinmohammad

    2015-10-01

    Full Text Available Background: The aim of this study was to generate in silico 3D-structure of the envelope protein of AHFV using homology modeling method to further predict its conformational epitopes and help other studies to investigate itsstructural features using the model.Methods: A 3D-structure prediction was developed for the envelope protein of Alkhumra haemorrhagic fever virus (AHFV, an emerging tick-borne flavivirus, based on a homology modeling method using M4T and Modwebservers, as the 3D-structure of the protein is not available yet. Modeled proteins were validated using Modfold 4 server and their accuracies were calculated based on their RSMDs. Having the 3D predicted model with high quality, conformational epitopes were predicted using DiscoTope 2.0.Results: Model generated by M4T was more acceptable than the Modweb-generated model. The global score and Pvalue calculated by Modfold 4 ensured that a certifiable model was generated by M4T, since its global score was almost near 1 which is the score for a high resolution X-ray crystallography structure. Furthermore, itsthe P-value was much lower than 0.001 which means that the model is completely acceptable. Having 0.46 Å rmsd, this model was shown to be highly accurate. Results from DiscoTope 2.0 showed 26 residues as epitopes, forming conformational epitopes of the modeled protein.Conclusion: The predicted model and epitopes for envelope protein of AHFV can be used in several therapeutic and diagnostic approaches including peptide vaccine development, structure based drug design or diagnostic kit development in order to facilitate the time consuming experimental epitope mapping process.

  6. Linking species abundance distributions in numerical abundance and biomass through simple assumptions about community structure

    OpenAIRE

    Henderson, Peter A.; Magurran, Anne E

    2010-01-01

    Species abundance distributions (SADs) are widely used as a tool for summarizing ecological communities but may have different shapes, depending on the currency used to measure species importance. We develop a simple plotting method that links SADs in the alternative currencies of numerical abundance and biomass and is underpinned by testable predictions about how organisms occupy physical space. When log numerical abundance is plotted against log biomass, the species lie within an approximat...

  7. Climate and local abundance in freshwater fishes.

    Science.gov (United States)

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  8. PREDICTION OF LONG TERM CHANGE OF ABUNDANCE OF LARGE INVERTEBRATES IN THE JIAOZHOU BAY, YELLOW SEA%胶州湾大型无脊椎动物数量的多年变化与趋势预测

    Institute of Scientific and Technical Information of China (English)

    刘瑞玉; 黄勃; 徐凤山; 李笑红

    2001-01-01

    The shallow waters along the Yellow Sea coast are rich in large economic invertebrates such as the decapod and stomatopod crustaceans and cephalopod molluscs which are main catches of local fisheries. Most species of these groups spawn in shallow coastal waters in late spring or early summer by May, the new born juveniles feed and grow fast in summer and autumn when water temperature is comparatively high. Some of them migrate to offshore waters where food organisms are rich. Most of them may grow up into the recruitment stock and the peak of their abundance appeared generally in August. Recent over-exploitation of coastal fishery resources by growing fishing effort resulted in great change of abundance and stock size of most species of these invertebrates. The stock size of most of these economic species decreased obviously in recent years as compared with those data obtained in the 1980′s excepting certain species whose stock size seems to be increased. The present paper predicts the trend of the long term change in abundance of the main species of large invertebrates by the functions based upon the trawling data obtained in May and August of 1981,1985,1989 and 1993. The functions simulating the trend of this change in May, model (1), and in August, model (2), are developed as follows: X=-4275.244e-0.4302066t+5527.244 (1) X=-11266.9e-1.202198t+14456.9 (2) Where X is individual number, t is time (year).   According to model (1) and Fig.1, the number of individuals of these invertebrates show a declining trend since 1985, when an average catch of 1480 ind./(net*h) in 1989 decreased to 1076, in 1993 to a low of 556. The most obviously decreased number may be seen in Charybdis japonica, Sepiella maindroni, Sepia esculenta and Fenneropenaeus chinensis. The decrease of brood stock of Sepiella in May resulted in the decrease of its number of individuals in August.   Based on the model (2) and Fig.2, similar results have been seen with the exception of Loligo

  9. Testing Relationships between Energy and Vertebrate Abundance

    International Nuclear Information System (INIS)

    Understanding what drives variation in the abundance of organisms is fundamental to evolutionary ecology and wildlife management. Yet despite its importance, there is still great uncertainty about the main factors influencing variation in vertebrate abundance across taxa. We believe valuable knowledge and increased predictive power could be gained by taking into account both the intrinsic factors of species and the extrinsic factors related to environmental surroundings in the commonly cited RQ model, which provides a simple conceptual framework valid at both the interspecific and the intraspecific scales. Approaches comparing studies undertaken at different spatial and taxonomic scales could be key to our ability to better predict abundance, and thanks to the increased availability of population size data, global geographic datasets, and improved comparative methods, there might be unprecedented opportunities to (1) gain a greater understanding of vertebrate abundance patterns and (2) test existing theories on free-ranging animals.

  10. OXYGEN ABUNDANCES IN CEPHEIDS

    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  11. Modelling Void Abundance in Modified Gravity

    CERN Document Server

    Voivodic, Rodrigo; Llinares, Claudio; Mota, David F

    2016-01-01

    We use a spherical model and an extended excursion set formalism with drifting diffusive barriers to predict the abundance of cosmic voids in the context of general relativity as well as f(R) and symmetron models of modified gravity. We detect spherical voids from a suite of N-body simulations of these gravity theories and compare the measured void abundance to theory predictions. We find that our model correctly describes the abundance of both dark matter and galaxy voids, providing a better fit than previous proposals in the literature based on static barriers. We use the simulation abundance results to fit for the abundance model free parameters as a function of modified gravity parameters, and show that counts of dark matter voids can provide interesting constraints on modified gravity. For galaxy voids, more closely related to optical observations, we find that constraining modified gravity from void abundance alone may be significantly more challenging. In the context of current and upcoming galaxy surv...

  12. 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

  13. The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors

    CERN Document Server

    Delahaye, F; Delahaye, Franck; Pinsonneault, Marc

    2005-01-01

    The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (<2 \\sigma) with the seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and th...

  14. Surface abundances of ON stars

    CERN Document Server

    Martins, F; Palacios, A; Howarth, I; Georgy, C; Walborn, N R; Bouret, J -C; Barba, R

    2015-01-01

    Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle or not is not known. Our goal is to answer this question. We perform a spectroscopic analysis of a sample of ON stars with atmosphere models. We determine the fundamental parameters as well as the He, C, N, and O surface abundances. We also measure the projected rotational velocities. We compare the properties of the ON stars to those of normal O stars. We show that ON stars are usually helium-rich. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cann...

  15. Interstellar Atomic Abundances

    CERN Document Server

    Jenkins, E B

    2003-01-01

    A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the interstellar medium. By comparing these abundances with reference values in the Sun, we find that some elements have abundances relative to hydrogen that are approximately consistent with their respective solar values, while others are depleted by factors that range from a few up to around 1000. These depletions are caused by the atoms condensing into solid form onto dust grains. Their strengths are governed by the volatility of compounds that are produced, together with the densities and velocities of the gas clouds. We may characterize the depletion trends in terms of a limited set of parameters; ones derived here are based on measurements of 15 elements toward 144 stars with known values of N(H I) and N(H2). In turn, these parameters may be applied to studies of the production, de...

  16. Clonal growth and plant species abundance

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-01-01

    Background and Aims Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf–height–seed) traits and by actual performance in the botanical garden. Methods Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area – height – seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. Key Results After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Conclusions Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially

  17. Planetary nebulae abundances and stellar evolution

    CERN Document Server

    Pottasch, S R

    2006-01-01

    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these gradients at the distance of the Sun from the center are exactly the solar abundance. Sulfur is the exception to this; the reason for this is discussed. The higher solar neon abundance is confirmed; this is discussed in terms of the results of helioseismology. Evidence is presented for oxygen destruction via ON cycling having occurred in the progenitors of four planetary nebulae with bilobal structure. These progenitor stars had a high mass, probably greater than 5 solar masses. This is deduced from the high values of He/H and N/H found in these nebulae. Formation of nitrogen, helium and carbon are discussed. The high mass progenitors which showed oxygen de...

  18. Predicting the potential environmental suitability for Theileria orientalis transmission in New Zealand cattle using maximum entropy niche modelling.

    Science.gov (United States)

    Lawrence, K E; Summers, S R; Heath, A C G; McFadden, A M J; Pulford, D J; Pomroy, W E

    2016-07-15

    The tick-borne haemoparasite Theileria orientalis is the most important infectious cause of anaemia in New Zealand cattle. Since 2012 a previously unrecorded type, T. orientalis type 2 (Ikeda), has been associated with disease outbreaks of anaemia, lethargy, jaundice and deaths on over 1000 New Zealand cattle farms, with most of the affected farms found in the upper North Island. The aim of this study was to model the relative environmental suitability for T. orientalis transmission throughout New Zealand, to predict the proportion of cattle farms potentially suitable for active T. orientalis infection by region, island and the whole of New Zealand and to estimate the average relative environmental suitability per farm by region, island and the whole of New Zealand. The relative environmental suitability for T. orientalis transmission was estimated using the Maxent (maximum entropy) modelling program. The Maxent model predicted that 99% of North Island cattle farms (n=36,257), 64% South Island cattle farms (n=15,542) and 89% of New Zealand cattle farms overall (n=51,799) could potentially be suitable for T. orientalis transmission. The average relative environmental suitability of T. orientalis transmission at the farm level was 0.34 in the North Island, 0.02 in the South Island and 0.24 overall. The study showed that the potential spatial distribution of T. orientalis environmental suitability was much greater than presumed in the early part of the Theileria associated bovine anaemia (TABA) epidemic. Maximum entropy offers a computer efficient method of modelling the probability of habitat suitability for an arthropod vectored disease. This model could help estimate the boundaries of the endemically stable and endemically unstable areas for T. orientalis transmission within New Zealand and be of considerable value in informing practitioner and farmer biosecurity decisions in these respective areas. PMID:27270395

  19. Abundance, Excess, Waste

    Directory of Open Access Journals (Sweden)

    Rox De Luca

    2016-02-01

    Her recent work focuses on the concepts of abundance, excess and waste. These concerns translate directly into vibrant and colourful garlands that she constructs from discarded plastics collected on Bondi Beach where she lives. The process of collecting is fastidious, as is the process of sorting and grading the plastics by colour and size. This initial gathering and sorting process is followed by threading the components onto strings of wire. When completed, these assemblages stand in stark contrast to the ease of disposability associated with the materials that arrive on the shoreline as evidence of our collective human neglect and destruction of the environment around us. The contrast is heightened by the fact that the constructed garlands embody the paradoxical beauty of our plastic waste byproducts, while also evoking the ways by which those byproducts similarly accumulate in randomly assorted patterns across the oceans and beaches of the planet.

  20. A molecular study of tick-borne haemoprotozoan parasites (Theileria and Babesia) in small ruminants in Northern Tunisia.

    Science.gov (United States)

    M'ghirbi, Youmna; Ros-García, Amaia; Iribar, Pilar; Rhaim, Adel; Hurtado, Ana; Bouattour, Ali

    2013-11-15

    In this study, the frequency of Theileria and Babesia species in sheep and goats was assessed via reverse line blotting (RLB). A total of 263 apparently healthy sheep and goats, from 16 randomly selected flocks located in 9 localities situated in 3 bioclimatic zones in Tunisia, were investigated for the blood protozoans. RLB hybridization with polymerase chain reaction detected only Theileria ovis in sheep and goats, accounting for 22.4% (95% confidence interval [CI]: 17.6-27.1%) positive samples. The infection rate in sheep (28.1%; 95% CI: 23.8-32.3%) was higher than in goats (4.7%; 95% CI: -10.9 to 20.4%). Neither Babesia nor mixed infections were detected. Only two Ixodid tick species (Rhipicephalus turanicus and Rhipicephalus bursa) were collected from the examined sheep and goats in 5 localities. R. turanicus was the dominant species (95.5%) collected mainly in the humid zone, while apparently rare in the sub-humid zone. R. bursa was the only species collected in the semi-arid area. RLB analysis identified six different piroplasms in ticks, with an overall prevalence of 31.5% (95% CI: 28.1-34.9%). Twenty percent (95% CI: 14.4-25.5%) of the collected ticks tested positive for Theileria spp., 3% (95% CI: -5.6 to 11.6%) for Babesia spp. and 0.9% (95% CI: -8.1 to 9.9%) of the ticks harbored both genera; several of these species are not known to occur in small ruminants. This is the first report on the detection of Theileria and Babesia species DNA in small ruminants and ticks in Tunisia.

  1. Expressing the burden of tick-borne encephalitis (TBE) in disability-adjusted life years (DALYs) in Slovenia

    NARCIS (Netherlands)

    Smit, Renata; Postma, Maarten

    2015-01-01

    Question: The purpose of the present study is to estimate the burdens from the population- and individual perspectives for TBE in Slovenia, measured in DALYs, get an appraisal of its impact and evaluate the possibilities of cost-effectively reducing this burden. The burden of TBE has not yet been ex

  2. Research Strategies to Reduce Tick Densities and the Risk of Tick-borne Disease Transmission through Host-Targeted Control

    Science.gov (United States)

    While white-tailed deer are not reservoir hosts for the Lyme disease agent, Borrelia burgdorferi, they are the keystone host animal on which adult female blacklegged ticks engorge on blood that is essential to production of tick eggs and completion of the life cycle. This session explores current re...

  3. Cascading effect of economic globalization on human risks of scrub typhus and tick-borne rickettsial diseases.

    Science.gov (United States)

    Kuo, Chi-Chien; Huang, Jing-Lun; Shu, Pei-Yun; Lee, Pei-Lung; Kelt, Douglas A; Wang, Hsi-Chieh

    2012-09-01

    The increase in global travel and trade has facilitated the dissemination of disease vectors. Globalization can also indirectly affect vector-borne diseases through the liberalization of cross-border trade, which has far-reaching, worldwide effects on agricultural practices and may in turn influence vectors through the modification of the ecological landscape. While the cascading effect of economic globalization on vector-borne diseases, sometimes acting synergistically with regional agricultural policy, could be substantial and have significant economic, agricultural, and public health implications, research into this remains very limited. We evaluated how abandonment of rice paddies in Taiwan after joining the World Trade Organization, along with periodic plowing, an agricultural policy to reduce farm pests in abandoned fields can unexpectedly influence risks to diseases transmitted by ticks and chiggers (larval trombiculid mites), which we collected from their small-mammal hosts. Sampling was limited to abandoned (fallow) and plowed fields due to the challenge of trapping small mammals in flooded rice paddies. Striped field mice (Apodemus agrarius) are the main hosts for both vectors. They harbored six times more ticks and three times more chiggers in fallow than in plowed plots. The proportion of ticks infected with Rickettsia spp. (etiologic agent of spotted fever) was three times higher in fallow plots, while that of Orientia tsutsugamushi (scrub typhus) in chiggers was similar in both treatments. Fallow plots had more ground cover and higher vegetation than plowed ones. Moreover, ticks and chiggers in both field types were dominated by species known to infest humans. Because ticks and chiggers should exhibit very low survival in flooded rice paddies, we propose that farm abandonment in Taiwan, driven by globalization, may have inadvertently led to increased risks of spotted fever and scrub typhus. However, periodic plowing can unintentionally mitigate vector burdens. Economic globalization can have unexpected consequences on disease risk through modification of the agricultural landscape, but the outcome may also be influenced by agricultural policies, calling for further research on vector-borne diseases and their control from broader perspectives.

  4. Detection of Ehrlichia phagocytophila DNA in Ixodes ricinus Ticks from Areas in Switzerland Where Tick-Borne Fever Is Endemic

    OpenAIRE

    Pusterla, Nicola; Huder, Jon B.; Lutz, Hans; Braun, Ueli

    1998-01-01

    A total of 1,523 adult Ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for Ehrlichia phagocytophila via PCR. Of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive.

  5. 76 FR 12959 - Promoting Community Integrated Pest Management To Prevent Tick-Borne Diseases; Notice of Public...

    Science.gov (United States)

    2011-03-09

    ... objectives of the conference are to identify knowledge gaps and barriers to effective community-wide tick control; propose the next steps in addressing knowledge gaps and eliminating barriers; and develop a... knowledge gaps and barriers to effective community-wide tick IPM programs; propose the next steps...

  6. Tick-borne encephalitis virus (TBEV) – findings on cross reactivity and longevity of TBEV antibodies in animal sera

    OpenAIRE

    Klaus, Christine; Ziegler, Ute; Kalthoff, Donata; Hoffmann, Bernd; Beer, Martin

    2014-01-01

    Background By using animal sera as sentinels, natural TBEV foci could be identified and further analyses including investigations of ticks could be initiated. However, antibody response against TBEV-related flaviviruses might adversely affect the readout of such a monitoring. Therefore, the cross-reactivity of the applied TBEV serology test systems – enzyme linked immunosorbent assay (ELISA) and virus neutralization test (VNT) – as well as the longevity of TBEV antibody titres in sheep and go...

  7. Biosurveillance in Central Asia: Successes and Challenges of Tick-Borne Disease Research in Kazakhstan and Kyrgyzstan

    OpenAIRE

    John eHay; Yeh, Kenneth B.; Debanjana eDasgupta; Zhanna eShapiyeva; Pavel eDeryabin; Christina eFarris; Roger eHewson; Allen eRichards; Gulnara eOmasheva; Talgat eNurmakhanov; Timur eAyazbayev; Asankadyr eZhunushov; Alexei eAndryushchenko

    2016-01-01

    Central Asia is a vast geographic region that includes five former Soviet Union republics: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The region has a unique infectious disease burden, and a history that includes Silk Road trade routes and networks that were part of the anti-plague and biowarfare programs in the former Soviet Union. Post Soviet Union biosurveillance research in this unique area of the world has met with several challenges, including lack of funding and ...

  8. IDENTIFICATION OF T-CELL EPITOPES IN STRUCTURAL PROTEINS OF TICK BORNE ENCEPHALITIS VIRUS FOR VACCINE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Dharmendra Kumar Chaudhary

    2012-05-01

    Full Text Available Tickborne encephalitis (TBE is a human viral infectious disease caused by tickborne encephalitis virus (TBEV. It is transmitted by the bite of an infected tick and also initiated the swelling of brain (encephalitis and spinal cord. There is a pressing need to develop potent and sufficient amount of drugs and vaccines for control of TBE. We have selected the structural proteins such as anchored core protein C, core protein C, premembrane, matrix and envelope proteins of TBEV for identification of T-cell epitopes using immunoinformatics tools. These epitopes were showed the highest binding affinity with major histocompatibility complex (MHC class I and II molecules. These finding may be used as an immunodiagnostic agent and also development of peptide based novel vaccines

  9. Isolation and Characterization of Borrelia hermsii Associated with Two Foci of Tick-Borne Relapsing Fever in California

    OpenAIRE

    Fritz, Curtis L; Bronson, Lawrence R.; Smith, Charles R.; Schriefer, Martin E.; Tucker, James R.; Schwan, Tom G.

    2004-01-01

    Relapsing fever, caused by the spirochete Borrelia hermsii and transmitted by the soft tick Ornithodoros hermsi, is endemic in many rural mountainous areas of California. Between 1996 and 1998, 12 cases of relapsing fever associated with two exposure sites in northern California were investigated. Follow-up at exposure sites included collection of soft ticks and serum specimens from sylvatic rodents. Attempts to cultivate spirochetes were made through inoculation of patient blood into mice an...

  10. The Helium abundance problem and non-minimally coupled quintessence

    OpenAIRE

    Chen, Xuelei

    2000-01-01

    There is a tension between observed Helium abundance and the prediction of the standard Big Bang Nucleosynthesis. We show that non-minimally quintessence model may help to reduce this tension between theory and observation.

  11. Simulation of arthropod abundance from plant composition

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2011-04-01

    Full Text Available The relationship between arthropod abundance and plant composition is extremely complex. It is very hard to develop a mechanistic model to describe the relationship. This study aimed to simulate arthropod abundance from plant composition on grassland using an artificial neural network developed by the author, and to compare simulation performances between the neural network and conventional models. The results revealed that there were complex interactions between plants and arthropods, and the arthropod abundance on grassland was significantly determined of plant families and their cover-degrees rather than plant species and their cover-degrees. Neural network exhibited a better simulation performance than multivariate regression and response surface model. Cross validation indicated that prediction performance of neural network was also superior to these models. It was concluded that neural network is an effective tool to model arthropod abundance from plant composition on grassland. A moderate dimensionality for input space may be determined to produce a reasonably trained neural network. Such procedures for dimensionality reduction as PCE, etc., were suggested being used in the data treatment in neural network modeling. A high dimensionality for input space and a few samples in the input set would result in the deficient learning of neural network. Randomization procedure for sample submission would help to eliminate the sequence correlation but may result in a worse performance in simulation and prediction. It was suggested that randomization procedure could be used to the sample submission for these situations with a lot of samples and a lower dimensionality.

  12. Primordial Deuterium Abundance Measurements

    CERN Document Server

    Levshakov, S A; Takahara, F; Levshakov, Sergei A.; Kegel, Wilhelm H.; Takahara, Fumio

    1997-01-01

    Deuterium abundances measured recently from QSO absorption-line systems lie in the range from 3 10^{-5} to 3 10^{-4}, which shed some questions on standard big bang theory. We show that this discordance may simply be an artifact caused by inadequate analysis ignoring spatial correlations in the velocity field in turbulent media. The generalized procedure (accounting for such correlations) is suggested to reconcile the D/H measurements. An example is presented based on two high-resolution observations of Q1009+2956 (low D/H) [1,2] and Q1718+4807 (high D/H) [8,9]. We show that both observations are compatible with D/H = 4.1 - 4.6 10^{-5}, and thus support SBBN. The estimated mean value = 4.4 10^{-5} corresponds to the baryon-to-photon ratio during SBBN eta = 4.4 10^{-10} which yields the present-day baryon density Omega_b h^2 = 0.015.

  13. Evolution of dispersion in the cosmic deuterium abundance

    Science.gov (United States)

    Dvorkin, Irina; Vangioni, Elisabeth; Silk, Joseph; Petitjean, Patrick; Olive, Keith A.

    2016-05-01

    Deuterium is created during big bang nucleosynthesis, and, in contrast to the other light stable nuclei, can only be destroyed thereafter by fusion in stellar interiors. In this Letter, we study the cosmic evolution of the deuterium abundance in the interstellar medium (ISM) and its dispersion using realistic galaxy evolution models. We find that models that reproduce the observed metal abundance are compatible with observations of the deuterium abundance in the local ISM and z ˜ 3 absorption line systems. In particular, we reproduce the low astration factor which we attribute to a low global star formation efficiency. We calculate the dispersion in deuterium abundance arising from different structure formation histories in different parts of the Universe. Our model also predicts a tight correlation between deuterium and metal abundances which could be used to measure the primordial deuterium abundance.

  14. Surface abundances of ON stars

    Science.gov (United States)

    Martins, F.; Simón-Díaz, S.; Palacios, A.; Howarth, I.; Georgy, C.; Walborn, N. R.; Bouret, J.-C.; Barbá, R.

    2015-06-01

    Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. Aims: ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. Methods: We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars. Results: We show that ON stars are usually rich in helium. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Mass transfer is therefore not a simple explanation for the observed chemical properties. Conclusions: We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present. Based on observations obtained 1) at the Anglo-Australian Telescope; 2) at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii; 3) at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 086.D-0997; 4) the Nordic Optical Telescope, operated on the island of La

  15. The shape of terrestrial abundance distributions.

    Science.gov (United States)

    Alroy, John

    2015-09-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood-related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the "double geometric." Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  16. Solar System Abundances of the Elements

    CERN Document Server

    Lodders, Katharina

    2010-01-01

    Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric measurements are presented.

  17. The primordial deuterium abundance problems and prospects

    CERN Document Server

    Levshakov, S A; Kegel, W H; Levshakov, Sergei A.; Takahara, Fumio; Kegel, Wilhelm H.

    1997-01-01

    The current status of extragalactic deuterium abundance is discussed using two examples of `low' and `high' D/H measurements. We show that the discordance of these two types of D abundances may be a consequence of the spatial correlations in the stochastic velocity field. Within the framework of the generalized procedure (accounting for such effects) one finds good agreement between different observations and the theoretical predictions for standard big bang nucleosynthesis (SBBN). In particular, we show that the deuterium absorption seen at z = 2.504 toward Q1009+2956 and the H+D Ly-alpha profile observed at z = 0.701 toward Q1718+4807 are compatible with D/H $\\sim 4.1 - 4.6\\times10^{-5}$. This result supports SBBN and, thus, no inhomogeneity is needed. The problem of precise D/H measurements is discussed.

  18. Gaseous abundances in M82

    CERN Document Server

    Ranalli, P; Origlia, L; Maiolino, R; Makishima, K; Ranalli, Piero; Comastri, Andrea; Origlia, Livia; Maiolino, Roberto; Makishima, Kazuo

    2005-01-01

    We present the preliminary analysis of a deep (100ks) XMM-Newton observation of M82. The spatial distribution of the abundances of chemical elements (Fe, O, Ne, Mg, Si, S) is investigated through narrow-band imaging analisys and spatially-resolved spectroscopy. We find that the abundances of alpha-elements follow a bipolar distribution, these elements being more abundant in the gaseous outflow than in the galaxy centre. This behaviour is found to be more marked for lighter elements (O, Ne) than for heavier elements.

  19. Halo abundances within the cosmic web

    Science.gov (United States)

    Alonso, D.; Eardley, E.; Peacock, J. A.

    2015-03-01

    We investigate the dependence of the mass function of dark-matter haloes on their environment within the cosmic web of large-scale structure. A dependence of the halo mass function on large-scale mean density is a standard element of cosmological theory, allowing mass-dependent biasing to be understood via the peak-background split. On the assumption of a Gaussian density field, this analysis can be extended to ask how the mass function depends on the geometrical environment: clusters, filaments, sheets and voids, as classified via the tidal tensor (the Hessian matrix of the gravitational potential). In linear theory, the problem can be solved exactly, and the result is attractively simple: the conditional mass function has no explicit dependence on the local tidal field, and is a function only of the local density on the filtering scale used to define the tidal tensor. There is nevertheless a strong implicit predicted dependence on geometrical environment, because the local density couples statistically to the derivatives of the potential. We compute the predictions of this model and study the limits of their validity by comparing them to results deduced empirically from N-body simulations. We have verified that, to a good approximation, the abundance of haloes in different environments depends only on their densities, and not on their tidal structure. In this sense we find relative differences between halo abundances in different environments with the same density which are smaller than ˜13 per cent. Furthermore, for sufficiently large filtering scales, the agreement with the theoretical prediction is good, although there are important deviations from the Gaussian prediction at small, non-linear scales. We discuss how to obtain improved predictions in this regime, using the `effective-universe' approach.

  20. Urban Warming Drives Insect Pest Abundance on Street Trees

    OpenAIRE

    Meineke, Emily K.; Robert R Dunn; Sexton, Joseph O.; Frank, Steven D.

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within c...

  1. Monitoring waterbird abundance in wetlands: The importance of controlling results for variation in water depth

    Science.gov (United States)

    Bolduc, F.; Afton, A.D.

    2008-01-01

    Wetland use by waterbirds is highly dependent on water depth, and depth requirements generally vary among species. Furthermore, water depth within wetlands often varies greatly over time due to unpredictable hydrological events, making comparisons of waterbird abundance among wetlands difficult as effects of habitat variables and water depth are confounded. Species-specific relationships between bird abundance and water depth necessarily are non-linear; thus, we developed a methodology to correct waterbird abundance for variation in water depth, based on the non-parametric regression of these two variables. Accordingly, we used the difference between observed and predicted abundances from non-parametric regression (analogous to parametric residuals) as an estimate of bird abundance at equivalent water depths. We scaled this difference to levels of observed and predicted abundances using the formula: ((observed - predicted abundance)/(observed + predicted abundance)) ?? 100. This estimate also corresponds to the observed:predicted abundance ratio, which allows easy interpretation of results. We illustrated this methodology using two hypothetical species that differed in water depth and wetland preferences. Comparisons of wetlands, using both observed and relative corrected abundances, indicated that relative corrected abundance adequately separates the effect of water depth from the effect of wetlands. ?? 2008 Elsevier B.V.

  2. Stellar Mixing and the Primordial Lithium Abundance

    CERN Document Server

    Pinsonneault, M H; Walker, T P; Narayanan, V K

    2002-01-01

    We compare the properties of recent samples of the lithium abundances in halo stars to one another and to the predictions of theoretical models including rotational mixing, and we examine the data for trends with metal abundance. We find from a KS test that in the absence of any correction for chemical evolution, the Ryan, Norris, & Beers (1999} sample is fully consistent with mild rotational mixing induced depletion and, therefore, with an initial lithium abundance higher than the observed value. Tests for outliers depend sensitively on the threshold for defining their presence, but we find a 10$--$45% probability that the RNB sample is drawn from the rotationally mixed models with a 0.2 dex median depletion (with lower probabilities corresponding to higher depletion factors). When chemical evolution trends (Li/H versus Fe/H) are treated in the linear plane we find that the dispersion in the RNB sample is not explained by chemical evolution; the inferred bounds on lithium depletion from rotational mixing...

  3. How selection structures species abundance distributions

    Science.gov (United States)

    Magurran, Anne E.; Henderson, Peter A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in large bodied species in guilds where habitat structure provides protection from predators, but not in those guilds associated with open habitats and where safety in numbers is a mechanism for reducing predation risk. We further demonstrate that while there is temporal turnover in the abundances and identities of species that comprise these guilds, guild rank order is conserved across our 30-year time series. These results demonstrate that ecological communities are not randomly assembled but can be decomposed into guilds where capacity is predictably allocated among species. PMID:22787020

  4. Solar and stellar photospheric abundances

    Science.gov (United States)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  5. Surface abundances of OC supergiants

    CERN Document Server

    Martins, F; Bouret, J -C; Barba, R; Howarth, I

    2016-01-01

    Some O and B stars show unusually strong or weak lines of carbon and/or nitrogen. These objects are classified as OBN or OBC stars. It has recently been shown that nitrogen enrichment and carbon depletion are the most likely explanations for the existence of the ON class. We investigate OC stars (all being supergiants) to check that surface abundances are responsible for the observed anomalous line strengths. We perform a spectroscopic analysis of three OC supergiants using atmosphere models. A fourth star was previously studied by us. Our sample thus comprises all OC stars known to date in the Galaxy. We determine the stellar parameters and He, C, N, and O surface abundances. We show that all stars have effective temperatures and surface gravities fully consistent with morphologically normal O supergiants. However, OC stars show little, if any, nitrogen enrichment and carbon surface abundances consistent with the initial composition. OC supergiants are thus barely chemically evolved, unlike morphologically n...

  6. Solar and Stellar Photospheric Abundances

    CERN Document Server

    Prieto, Carlos Allende

    2016-01-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  7. Influence of edge on predator prey distribution and abundance

    Science.gov (United States)

    Ferguson, Steven H.

    2004-03-01

    I investigated the effect of spatial configuration on distribution and abundance of invertebrate trophic groups by counting soil arthropods under boxes (21 × 9.5 cm) arranged in six different patterns that varied in the amount of edge (137-305 cm). I predicted fewer individuals from the consumer trophic group (Collembola) in box groups with greater amount of edge. This prediction was based on the assumption that predators (mites, ants, spiders, centipedes) select edge during foraging and thereby reduce abundance of the less mobile consumer group under box patterns with greater edge. Consumer abundance (Collembola) was not correlated with amount of edge. Among the predator groups, mite, ant and centipede abundance related to the amount of edge of box groups. However, in contrast to predictions, abundance of these predators was negatively correlated with amount of edge in box patterns. All Collembola predators, with the exception of ants, were less clumped in distribution than Collembola. The results are inconsistent with the view that predators used box edges to predate the less mobile consumer trophic group. Alternative explanations for the spatial patterns other than predator-prey relations include (1) a negative relationship between edge and moisture, (2) a positive relationship between edge and detritus decomposition (i.e. mycelium as food for the consumer group), and (3) a negative relationship between edge and the interstices between adjacent boxes. Landscape patterns likely affect microclimate, food, and predator-prey relations and, therefore, future experimental designs need to control these factors individually to distinguish among alternative hypotheses.

  8. Coho Abundance - Point Features [ds182

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  9. Coho Abundance - Linear Features [ds183

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  10. Chinook Abundance - Point Features [ds180

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  11. Steelhead Abundance - Linear Features [ds185

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  12. Steelhead Abundance - Point Features [ds184

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  13. Abundance estimation and Conservation Biology

    Directory of Open Access Journals (Sweden)

    Nichols, J. D.

    2004-06-01

    Full Text Available Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001. The initial capture–recapture models developed for partially (Darroch, 1959 and completely (Jolly, 1965; Seber, 1965 open populations represented efforts to relax the restrictive assumption of population closure for the purpose of estimating abundance. Subsequent emphases in capture–recapture work were on survival rate estimation in the 1970’s and 1980’s (e.g., Burnham et al., 1987; Lebreton et al.,1992, and on movement estimation in the 1990’s (Brownie et al., 1993; Schwarz et al., 1993. However, from the mid–1990’s until the present time, capture–recapture investigators have expressed a renewed interest in abundance and related parameters (Pradel, 1996; Schwarz & Arnason, 1996; Schwarz, 2001. The focus of this session was abundance, and presentations covered topics ranging from estimation of abundance and rate of change in abundance, to inferences about the demographic processes underlying changes in abundance, to occupancy as a surrogate of abundance. The plenary paper by Link & Barker (2004 is provocative and very interesting, and it contains a number of important messages and suggestions. Link & Barker (2004 emphasize that the increasing complexity of capture–recapture models has resulted in large numbers of parameters and that a challenge to ecologists is to extract ecological signals from this complexity. They offer hierarchical models as a natural approach to inference in which traditional parameters are viewed as realizations of stochastic processes. These processes are governed by hyperparameters, and the inferential approach focuses on these hyperparameters. Link & Barker (2004 also suggest that

  14. Model reduction for stochastic chemical systems with abundant species

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon [School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH93JR, Scotland (United Kingdom)

    2015-12-07

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  15. Model reduction for stochastic chemical systems with abundant species

    Science.gov (United States)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-01

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  16. Interaction of detritus with abundance of cyanobacteria and microalgae

    NARCIS (Netherlands)

    Gons, H.J.

    1995-01-01

    Detritus particles interact with phytoplankton growth through light attenuation and nutrient retention. A model is described for predicting abundance of cyanobacteria and microalgae in relation to the detritus dynamics in shallow lakes with varying phosphorus load. Steady-state P distribution among

  17. Big Bang Nucleosynthesis and the Observed Abundances of Light Elements

    OpenAIRE

    Hogan, Craig J.

    1996-01-01

    The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars. It is concluded that the prospects are good for a precise test of the theory.

  18. Comparing halo bias from abundance and clustering

    CERN Document Server

    Hoffmann, Kai; Gaztanaga, Enrique

    2015-01-01

    We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

  19. Abundances in stars with exoplanets

    OpenAIRE

    Israelian, Garik

    2003-01-01

    Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtle trends of different chemical elements begin to appear as the number of detected extrasolar planetary systems continues to grow. I review our current knowledge concerning the observed abundance trends of various chemical elements in stars with exoplanets and their possible implications.

  20. Occupancy as a surrogate for abundance estimation

    Directory of Open Access Journals (Sweden)

    MacKenzie, D. I.

    2004-06-01

    Full Text Available In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of detectability must be taken into account in order to make accurate inferences: the non-detection of the species does not imply the species is genuinely absent. Here we review some recent modelling developments that permit unbiased estimation of the proportion of area occupied, colonization and local extinction probabilities. These methods allow for unequal sampling effort and enable covariate information on sampling locations to be incorporated. We also describe how these models could be extended to incorporate information from marked individuals, which would enable finer questions of population dynamics (such as turnover rate of nest sites by specific breeding pairs to be addressed. We believe these models may be applicable to a wide range of bird species and may be useful for investigating various questions of ecological interest. For example, with respect to habitat quality, we might predict that a species is more likely to have higher local extinction probabilities, or higher turnover rates of specific breeding pairs, in poor quality habitats.

  1. Beryllium abundances in stars hosting giant planets

    CERN Document Server

    Santos, N C; Israelian, G; Mayor, M; Rebolo, R; García-Gíl, A; Pérez de Taoro, M R; Randich, S

    2002-01-01

    We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated stars. Predictions from current models are compared with the derived abundances and suggestions are provided to explain the observed inconsistencies. We show that while still not clear, the results suggest that theoretical models may have to be revised for stars with Teff<5500K. On the other hand, a comparison between planet host and non-planet host stars shows no clear difference between both populations. Although preliminary, this result favors a ``primordial'' origin for the metallicity ``excess'' observed for the planetary host stars. Under this assumption, i.e. that there would be no differences between stars with and without giant planets, the light element depletion pattern of our sample of stars may also be used to further investigate and constraint Li and Be deple...

  2. Oxygen Gas Phase Abundance Revisited

    CERN Document Server

    André, M K; Howk, J C; Ferlet, R; Désert, J M; Hébrard, G; Lacour, S; Lecavelier-des-Etangs, A; Vidal-Madjar, A; Moos, H W

    2003-01-01

    We present new measurements of the interstellar gas-phase oxygen abundance along the sight lines towards 19 early-type galactic stars at an average distance of 2.6 kpc. We derive O {\\small I} column densities from {\\it HST}/STIS observations of the weak 1355 \\AA intersystem transition. We derive total hydrogen column densities [N(H {\\small I})+2N(H$_2$)] using {\\it HST}/STIS observations of \\lya and {\\it FUSE} observations of molecular hydrogen. The molecular hydrogen content of these sight lines ranges from f(H$_2$) = 2N(H$_2$)/[N(H {\\small I})+2N(H$_2$)] = 0.03 to 0.47. The average $$ of 6.3$\\times10^{21}$ cm$^{-2}$ mag$^{-1}$ with a standard deviation of 15% is consistent with previous surveys. The mean oxygen abundance along these sight lines, which probe a wide range of galactic environments in the distant ISM, is 10$^6$ \\oh = $408 \\pm 13$ (1 $\\sigma$ in the mean). %$({\\rm O/H})_{gas} = 408 \\pm 14$(1 $\\sigma$). We see no evidence for decreasing gas-phase oxygen abundance with increasing molecular hydroge...

  3. Protein abundance profiling of the Escherichia coli cytosol

    Directory of Open Access Journals (Sweden)

    Mann Matthias

    2008-02-01

    Full Text Available Abstract Background Knowledge about the abundance of molecular components is an important prerequisite for building quantitative predictive models of cellular behavior. Proteins are central components of these models, since they carry out most of the fundamental processes in the cell. Thus far, protein concentrations have been difficult to measure on a large scale, but proteomic technologies have now advanced to a stage where this information becomes readily accessible. Results Here, we describe an experimental scheme to maximize the coverage of proteins identified by mass spectrometry of a complex biological sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed emPAI approach which takes into account the number of sequenced peptides per protein. The values of abundance are within a broad range and accurately reflect independently measured copy numbers per cell. As expected, the most abundant proteins were those involved in protein synthesis, most notably ribosomal proteins. Proteins involved in energy metabolism as well as those with binding function were also found in high copy number while proteins annotated with the terms metabolism, transcription, transport, and cellular organization were rare. The barrel-sandwich fold was found to be the structural fold with the highest abundance. Highly abundant proteins are predicted to be less prone to aggregation based on their length, pI values, and occurrence patterns of hydrophobic stretches. We also find that abundant proteins tend to be predominantly essential. Additionally we observe a significant correlation between protein and mRNA abundance in E. coli cells. Conclusion Abundance measurements for more than 1000 E. coli proteins presented in this work

  4. Analysis and modeling of scale-invariance in plankton abundance

    CERN Document Server

    Pelletier, J D

    1996-01-01

    The power spectrum, $S$, of horizontal transects of plankton abundance are often observed to have a power-law dependence on wavenumber, $k$, with exponent close to $-2$: $S(k)\\propto k^{-2}$ over a wide range of scales. I present power spectral analyses of aircraft lidar measurements of phytoplankton abundance from scales of 1 to 100 km. A power spectrum $S(k)\\propto k^{-2}$ is obtained. As a model for this observation, I consider a stochastic growth equation where the rate of change of plankton abundance is determined by turbulent mixing, modeled as a diffusion process in two dimensions, and exponential growth with a stochastically variable net growth rate representing a fluctuating environment. The model predicts a lognormal distribution of abundance and a power spectrum of horizontal transects $S(k)\\propto k^{-1.8}$, close to the observed spectrum. The model equation predicts that the power spectrum of variations in abundance in time at a point in space is $S(f)\\propto f^{-1.5}$ (where $f$ is the frequency...

  5. Urban warming drives insect pest abundance on street trees.

    Science.gov (United States)

    Meineke, Emily K; Dunn, Robert R; Sexton, Joseph O; Frank, Steven D

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer. PMID:23544087

  6. Urban warming drives insect pest abundance on street trees.

    Directory of Open Access Journals (Sweden)

    Emily K Meineke

    Full Text Available Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

  7. Chemical abundances from planetary nebulae in local spiral galaxies

    CERN Document Server

    Richer, M G

    2015-01-01

    While the chemical abudances observed in bright planetary nebulae in local spiral galaxies are less varied than their counterparts in dwarfs, they provide new insight. Their helium abundances are typically enriched by less than 50\\% compared to the primordial abundance. Nitrogen abundances always show some level of secondary enrichment, but the absolute enrichment is not extreme. In particular, type I PNe are rare among the bright PNe in local spirals. The oxygen and neon abundances are very well correlated and follow the relation between these abundances observed in star-forming galaxies, implying that either the progenitor stars of these PNe modify neither abundance substantially or that they modify both to maintain the ratio (not predicted by theory). According to theory, these results imply that the progenitor stars of bright PNe in local spirals have masses of about $2\\,\\mathrm M_{\\odot}$ or less. If so, the progenitors of these PNe have substantial lifetimes that allow us to use them to study the recent...

  8. On ribosome load, codon bias and protein abundance.

    Directory of Open Access Journals (Sweden)

    Stefan Klumpp

    Full Text Available Different codons encoding the same amino acid are not used equally in protein-coding sequences. In bacteria, there is a bias towards codons with high translation rates. This bias is most pronounced in highly expressed proteins, but a recent study of synthetic GFP-coding sequences did not find a correlation between codon usage and GFP expression, suggesting that such correlation in natural sequences is not a simple property of translational mechanisms. Here, we investigate the effect of evolutionary forces on codon usage. The relation between codon bias and protein abundance is quantitatively analyzed based on the hypothesis that codon bias evolved to ensure the efficient usage of ribosomes, a precious commodity for fast growing cells. An explicit fitness landscape is formulated based on bacterial growth laws to relate protein abundance and ribosomal load. The model leads to a quantitative relation between codon bias and protein abundance, which accounts for a substantial part of the observed bias for E. coli. Moreover, by providing an evolutionary link, the ribosome load model resolves the apparent conflict between the observed relation of protein abundance and codon bias in natural sequences and the lack of such dependence in a synthetic gfp library. Finally, we show that the relation between codon usage and protein abundance can be used to predict protein abundance from genomic sequence data alone without adjustable parameters.

  9. Testing spherical evolution for modelling void abundances

    Science.gov (United States)

    Achitouv, Ixandra; Neyrinck, Mark; Paranjape, Aseem

    2015-08-01

    We compare analytical predictions of void volume functions to those measured from N-body simulations, detecting voids with the ZOBOV void finder. We push to very small, non-linear voids, below few Mpc radius, by considering the unsampled dark matter density field. We also study the case where voids are identified using haloes. We develop analytical formula for the void abundance of both the excursion set approach and the peaks formalism. These formulas are valid for random walks smoothed with a top-hat filter in real space, with a large class of realistic barrier models. We test the extent to which the spherical evolution approximation, which forms the basis of the analytical predictions, models the highly aspherical voids that occur in the cosmic web, and are found by a watershed-based algorithm such as ZOBOV. We show that the volume function returned by ZOBOV is quite sensitive to the choice of treatment of subvoids, a fact that has not been appreciated previously. For reasonable choices of subvoid exclusion, we find that the Lagrangian density δv of the ZOBOV voids - which is predicted to be a constant δv ≈ -2.7 in the spherical evolution model - is different from the predicted value, showing substantial scatter and scale dependence. This result applies to voids identified at z = 0 with effective radius between 1 and 10 h-1 Mpc. Our analytical approximations are flexible enough to give a good description of the resulting volume function; however, this happens for choices of parameter values that are different from those suggested by the spherical evolution assumption. We conclude that analytical models for voids must move away from the spherical approximation in order to be applied successfully to observations, and we discuss some possible ways forward.

  10. Lead abundance in the uranium star CS 31082-001

    DEFF Research Database (Denmark)

    Plez, B.; Hill, V.; Cayrel, R.;

    2004-01-01

    stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data......stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data...

  11. Razorbill - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  12. Dovekie - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  13. Richness-abundance relationships for zooplankton in ballast water: temperate versus Arctic comparisons

    OpenAIRE

    Chan, F T; Briski, Elizabeta; S. A. Bailey; MacIsaac, H. J.

    2014-01-01

    Species richness and abundance are two commonly measured parameters used to characterize invasion risk associated with transport vectors, especially those capable of transferring large species assemblages. Understanding the relationship between these two variables can further improve our ability to predict future invasions by identifying conditions where high-risk (i.e. species-rich or high abundance or both) and low-risk (i.e. species-poor and low abundance) introduction events are expected....

  14. Butterfly abundance is determined by food availability and is mediated by species traits

    OpenAIRE

    Curtis, Robin J.; Brereton, Tom M.; Roger L H Dennis; Carbone, Chris; Isaac, Nick J. B.

    2015-01-01

    1. Understanding the drivers of population abundance across species and sites is crucial for effective conservation management. At present, we lack a framework for predicting which sites are likely to support abundant butterfly communities. 2. We address this problem by exploring the determinants of abundance among 1111 populations of butterflies in the UK, spanning 27 species on 54 sites. Our general hypothesis is that the availability of food resources is a strong predictor of population...

  15. Immunological investments reflect parasite abundance in island populations of Darwin's finches.

    OpenAIRE

    Lindström, Karin M.; Foufopoulos, Johannes; Pärn, Henrik; Wikelski, Martin

    2004-01-01

    The evolution of parasite resistance can be influenced by the abundance of parasites in the environment. However, it is yet unresolved whether vertebrates change their investment in immune function in response to variation in parasite abundance. Here, we compare parasite abundance in four populations of small ground finches (Geospiza fuliginosa) in the Galapagos archipelago. We predicted that populations exposed to high parasite loads should invest more in immune defence, or alternatively use...

  16. Klima og vektorbårne sygdomme

    DEFF Research Database (Denmark)

    Bygbjerg, Ib Christian; Schiøler, Karin Linda; Konradsen, Flemming

    2009-01-01

    The predicted changes in climate have raised concerns that vector-borne diseases may emerge or expand in tempered regions. Malaria, leishmaniasis and tick-borne illnesses are discussed in terms of climate change and their endemic potential, especially in Denmark. While climate may play an important...... role in disease patterns, it is evident that transmission potential is governed by a complex of factors, including socio-economy, health-care capacity and ecology. In Denmark, malaria and leishmaniasis are unlikely to become public health problems, whereas the potential for tick-borne illnesses may...

  17. [Climate- and vector-borne diseases

    DEFF Research Database (Denmark)

    Bygbjerg, I.C.; Schioler, K.L.; Konradsen, F.

    2009-01-01

    The predicted changes in climate have raised concerns that vector-borne diseases may emerge or expand in tempered regions. Malaria, leishmaniasis and tick-borne illnesses are discussed in terms of climate change and their endemic potential, especially in Denmark. While climate may play an important...... role in disease patterns, it is evident that transmission potential is governed by a complex of factors, including socio-economy, health-care capacity and ecology. In Denmark, malaria and leishmaniasis are unlikely to become public health problems, whereas the potential for tick-borne illnesses may...

  18. Abundance changes and habitat availability drive species' responses to climate change

    Science.gov (United States)

    Mair, Louise; Hill, Jane K.; Fox, Richard; Botham, Marc; Brereton, Tom; Thomas, Chris D.

    2014-02-01

    There is little consensus as to why there is so much variation in the rates at which different species' geographic ranges expand in response to climate warming. Here we show that the relative importance of species' abundance trends and habitat availability for British butterfly species vary over time. Species with high habitat availability expanded more rapidly from the 1970s to mid-1990s, when abundances were generally stable, whereas habitat availability effects were confined to the subset of species with stable abundances from the mid-1990s to 2009, when abundance trends were generally declining. This suggests that stable (or positive) abundance trends are a prerequisite for range expansion. Given that species' abundance trends vary over time for non-climatic as well as climatic reasons, assessment of abundance trends will help improve predictions of species' responses to climate change, and help us to understand the likely success of different conservation strategies for facilitating their expansions.

  19. Revised element abundances for WC-type central stars

    CERN Document Server

    Todt, H; Hamann, W -R

    2007-01-01

    According to previous spectral analyses of Wolf-Rayet type central stars, late [WC] subtypes show systematically higher carbon-to-helium abundance ratios than early [WC] subtypes. If this were true, it would rule out that these stars form an evolutionary sequence. However, due to the different parameter domains and diagnostic lines, one might suspect systematic errors being the source of this discrepancy. In an ongoing project we are therefore checking the [WC] analyses by means of the last generation of non-LTE models for expanding stellar atmospheres which account for line-blanketing and wind clumping. So far, the abundance discrepancy is not resolved. Further element abundances (H, N, Fe) are determined and compared with evolutionary predictions.

  20. Diversity is maintained by seasonal variation in species abundance

    Science.gov (United States)

    2013-01-01

    Background Some of the most marked temporal fluctuations in species abundances are linked to seasons. In theory, multispecies assemblages can persist if species use shared resources at different times, thereby minimizing interspecific competition. However, there is scant empirical evidence supporting these predictions and, to the best of our knowledge, seasonal variation has never been explored in the context of fluctuation-mediated coexistence. Results Using an exceptionally well-documented estuarine fish assemblage, sampled monthly for over 30 years, we show that temporal shifts in species abundances underpin species coexistence. Species fall into distinct seasonal groups, within which spatial resource use is more heterogeneous than would be expected by chance at those times when competition for food is most intense. We also detect seasonal variation in the richness and evenness of the community, again linked to shifts in resource availability. Conclusions These results reveal that spatiotemporal shifts in community composition minimize competitive interactions and help stabilize total abundance. PMID:24007204

  1. Solar System chemical abundances corrected for systematics

    OpenAIRE

    Gonzalez, Guillermo

    2014-01-01

    The relative chemical abundances between CI meteorites and the solar photosphere exhibit a significant trend with condensation temperature. A trend with condensation temperature is also seen when the solar photospheric abundances are compared to those of nearby solar twins. We use both these trends to determine the alteration of the elemental abundances of the meteorties and the photosphere by fractionation and calculate a new set of primordial Solar System abundances.

  2. Planetary nebulae abundances and stellar evolution II

    NARCIS (Netherlands)

    Pottasch, S. R.; Bernard-Salas, J.

    2010-01-01

    Context. In recent years mid-and far infrared spectra of planetary nebulae have been analysed and lead to more accurate abundances. It may be expected that these better abundances lead to a better understanding of the evolution of these objects. Aims. The observed abundances in planetary nebulae are

  3. Correlation between lithium abundances and ages of solar twin stars

    CERN Document Server

    Carlos, Marilia; Melendez, Jorge

    2016-01-01

    We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence of planets. For a sample of 21 solar twins observed with the HARPS spectrograph at high spectral resolution (R~115.000) and very high signal-to-noise ratio (600 < S/N < 2400), precise lithium abundances were obtained by spectral synthesis of the LiI 6707.8 A line and compared to stellar ages, masses, and metallicities determined from a spectroscopic analysis of the same set of HARPS spectra. We show that for the large majority of the solar twins there is a strong correlation between lithium abundance and stellar age. As the age increases from 1 to 9 Gyr, the Li abundance decreases by a factor of ~ 50. The relation agrees fairly well with predictions from non-standard stellar evolution models of Li destruction at the bottom of the upper convection zone. Two stars deviat...

  4. Lithium abundances in high- and low-alpha halo stars

    DEFF Research Database (Denmark)

    Nissen, P. E.; Schuster, W. J.

    2012-01-01

    is well fitted by a relation A(Li) = a0 + a1 M + a2 Z + a3 M Z, where a0, a1, a2, and a3 are constants. Extrapolating this relation to Z = 0 leads to A(Li)= 2.58 ± 0.08 close to the primordial Li abundance predicted from standard Big Bang nucleosynthesis calculations and the WMAP baryon density. A...

  5. Significant biases affecting abundance determinations

    Science.gov (United States)

    Wesson, Roger

    2015-08-01

    I have developed two highly efficient codes to automate analyses of emission line nebulae. The tools place particular emphasis on the propagation of uncertainties. The first tool, ALFA, uses a genetic algorithm to rapidly optimise the parameters of gaussian fits to line profiles. It can fit emission line spectra of arbitrary resolution, wavelength range and depth, with no user input at all. It is well suited to highly multiplexed spectroscopy such as that now being carried out with instruments such as MUSE at the VLT. The second tool, NEAT, carries out a full analysis of emission line fluxes, robustly propagating uncertainties using a Monte Carlo technique.Using these tools, I have found that considerable biases can be introduced into abundance determinations if the uncertainty distribution of emission lines is not well characterised. For weak lines, normally distributed uncertainties are generally assumed, though it is incorrect to do so, and significant biases can result. I discuss observational evidence of these biases. The two new codes contain routines to correctly characterise the probability distributions, giving more reliable results in analyses of emission line nebulae.

  6. Origin of Cosmic Chemical Abundances

    CERN Document Server

    Maio, Umberto

    2015-01-01

    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman-$\\alpha$ absorbers at redshift $z\\gtrsim 2$. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below $\\sim 10^4\\,\\rm K$, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/...

  7. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

  8. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  9. Stellar abundances of beryllium and CUBES

    CERN Document Server

    Smiljanic, R

    2014-01-01

    Stellar abundances of beryllium are useful in different areas of astrophysics, including studies of the Galactic chemical evolution, of stellar evolution, and of the formation of globular clusters. Determining Be abundances in stars is, however, a challenging endeavor. The two Be II resonance lines useful for abundance analyses are in the near UV, a region strongly affected by atmospheric extinction. CUBES is a new spectrograph planned for the VLT that will be more sensitive than current instruments in the near UV spectral region. It will allow the observation of fainter stars, expanding the number of targets where Be abundances can be determined. Here, a brief review of stellar abundances of Be is presented together with a discussion of science cases for CUBES. In particular, preliminary simulations of CUBES spectra are presented, highlighting its possible impact in investigations of Be abundances of extremely metal-poor stars and of stars in globular clusters.

  10. Monitoring Butterfly Abundance: Beyond Pollard Walks

    OpenAIRE

    Pellet, Jérôme; Bried, Jason T.; Parietti, David; Gander, Antoine; Heer, Patrick O.; Cherix, Daniel; Arlettaz, Raphaël

    2012-01-01

    Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly...

  11. 蜱媒脑炎自然疫源探究%A study on natural source of tick-borne cephalitis

    Institute of Scientific and Technical Information of China (English)

    陈国仕

    2004-01-01

    蜱媒脑炎包含森林脑炎(远东亚型)、西方蜱媒脑炎(中欧亚型)及双波脑膜脑炎。它们是虫媒病毒(Arboviruses)中黄病毒科(Flaviviridae)黄病毒属(Flavivirus)蜱媒脑炎群(tickborne encephalitis complex)中抗原上极其近似的森林脑炎病毒(Encephalophilus silvestris Zil’ber,1937年)、西方蜱媒脑炎病毒(Encephalophilus occidentalis Zil’ber,1945年)及双波脑膜

  12. Disability-adjusted life years (DALYs) as a composite measure to express the burden of tick-borne encephalitis (TBE) in Slovenia

    NARCIS (Netherlands)

    Smit, R.; Postma, M. J.

    2014-01-01

    Objectives: TBE is a serious central nervous system disease, which may lead to permanent neurological sequelae or even death. TBE is becoming a high burden in many parts of Europe, Asian Russia, Siberia, Asian former USSR and Far East. The burden is usually expressed by only the incidence or death.

  13. Ticks and tick-borne pathogens at the cutaneous interface: host defenses, tick countermeasures, and a suitable environment for pathogen establishment

    OpenAIRE

    Stephen eWikel

    2013-01-01

    Ticks are unique among hematophagous arthropods by continuous attachment to host skin and blood feeding for days; complexity and diversity of biologically active molecules differentially expressed in saliva of tick species; their ability to modulate the host defenses of pain and itch, hemostasis, inflammation, innate and adaptive immunity, and wound healing; and, the diverse array of infectious agents they transmit. All of these interactions occur at the cutaneous interface in a complex seque...

  14. Coexistence of antibodies to tick-borne agents of babesiosis and Lyme borreliosis in patients from Cotia county, State of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Natalino Hajime Yoshinari

    2003-04-01

    Full Text Available This paper reports a case of coinfection caused by pathogens of Lyme disease and babesiosis in brothers. This was the first case of borreliosis in Brazil, acquired in Cotia County, State of São Paulo, Brazil. Both children had tick bite history, presented erythema migrans, fever, arthralgia, mialgia, and developed positive serology (ELISA and Western-blotting directed to Borrelia burgdorferi G 39/40 and Babesia bovis antigens, mainly of IgM class antibodies, suggestive of acute disease. Also, high frequencies of antibodies to B. bovis was observed in a group of 59 Brazilian patients with Lyme borreliosis (25.4%, when compared with that obtained in a normal control group (10.2% (chi-square = 5.6; p < 0.05. Interestingly, both children presented the highest titers for IgM antibodies directed to both infective diseases, among all patients with Lyme borreliosis.

  15. Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man

    Directory of Open Access Journals (Sweden)

    Figueiredo Luiz Tadeu Moraes

    1999-01-01

    Full Text Available Specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the Southeast and Mid-West regions of Brazil. Nine species of Amblyommidae were identified: Anocentor nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus, and Rhipicephalus sanguineus. The potential of these tick species as transmitters of pathogens to man was analyzed. A Flaviviridade Flavivirus was isolated from Amblyomma cajennense specimens collected from a sick capybara (Hydrochaeris hydrochaeris. Amblyomma cajennense is the main transmitter of Rickettsia rickettsii (=R. rickettsi, the causative agent of spotted fever in Brazil. Wild mammals, mainly capybaras and deer, infested by ticks and living in close contact with cattle, horses and dogs, offer the risk of transmission of wild zoonosis to these domestic animals and to man.

  16. Status of tick distribution and tick-borne pathogens in Jinan city%济南市蜱分布及带病毒状况调查

    Institute of Scientific and Technical Information of China (English)

    辛正; 王东; 杨国樑; 王永明; 彭文广; 李羡亭; 齐梅; 王蕾; 李殿香

    2015-01-01

    Objective To investigate the species, host, distribution and status of tick⁃borne pathogens in Jinan city. Methods The parasitic ticks were collected from the host skin by hand or tweezers and the free ticks were collected manually with white cloth from the grassland or shrubbery. Collected ticks were classified and tested for tick⁃borne pathogens. Results There were 614 and 108 ticks collected on 6 hosts and in 2 types of environment, respectively. Collected ticks were Haemaphysalis longicornis. There were 596 ticks collected on goats with proportion of 97.1%. About 53.3%goats carried with ticks and the average number of ticks per goat was about 6.7. The results were positive in RNA detection of new bunyavirus in 3 groups of tick and positive of rickettsia in one group. Positive ticks were collected from goats. Conclusion The dominant tick species was H. longicornis in Shandong province. The dominant host animal was goats raised outside. Some ticks may carry bunyavirus and rickettsia.%目的:调查济南市丘陵地区蜱的种类、宿主、分布及其带病毒情况。方法采用宿主体表捡拾法采集寄生蜱、人工布旗法采集游离蜱,并进行分类鉴定和病原体检测。结果在宿主动物和环境中分别捕获蜱614和108只,经鉴定均为长角血蜱。其中,羊体表捕获蜱596只,占调查宿主动物的97.1%。所有宿主动物中,羊携带蜱比例最高(53.3%),带蜱指数最高(6.7只/只或头)。在3组蜱样本中检测到新型布尼亚病毒核酸阳性,1组蜱样本中检测到立克次体阳性,4份样本均来自羊群。结论济南市的优势蜱种为长角血蜱;放养羊群是当地蜱主要宿主动物;部分蜱可能携带新型布尼亚病毒和立克次体。

  17. 黑龙江口岸新发蜱传疾病的调查%Investigation of emerging tick-borne diseases at Heilongjiang ports

    Institute of Scientific and Technical Information of China (English)

    程成; 鞠文东; 焦丹; 付维明; 王艳梅; 王延禄; 呼满霞; 杨丽炜; 崔永民

    2015-01-01

    目的 调查黑龙江口岸地区蜱携带新发蜱传病原体的情况.方法 针对黑龙江省5个中俄边境口岸,2014年4-6月采集蜱类样本188份,利用PCR方法分别扩增5种新发蜱传病原体的特异性核酸片段,通过基因测序进一步鉴定并分型.结果 共检测出莱姆病螺旋体(Borrelia burgdorferi)阳性样本11例,巴贝西原虫(Babesia)1例,斑点热群立克次体(spotted fever group rickettsia) 101例,巴尔通体(Bartonella)6例,嗜吞噬细胞无形体(Anaplasma phagocytophilum)10例,感染率分别为5.85%、0.53%、53.7%、3.72%、5.32%.共发现8种病原体,分别是嘎氏疏螺旋体(Borrelia afzelii)、伽氏疏螺旋体(Borrelia garinii、巴贝西原虫属(Babesia sp.)、劳氏立克次体(Rickettsia raoultii)、新塔拉塞维奇立克次体(Candidatus Rickettsia tarasevichiae)、黑龙江立克次体(Rickettsia heilongjiangensis)、巴尔通体属(Bartonella sp.)、嗜吞噬细胞无形体(Anaplasma phagocytophilum).结论 黑龙江中俄边境存在新发蜱传疾病多样性的特征,提示应重点关注斑点热群立克次体感染,并开展蜱及蜱传疾病的常态监测.

  18. Prevalence of Human-Active and Variant 1 Strains of the Tick-Borne Pathogen Anaplasma phagocytophilum in Hosts and Forests of Eastern North America

    OpenAIRE

    Keesing, Felicia; McHenry, Diana J.; Hersh, Michelle; Tibbetts, Michael; Jesse L Brunner; Killilea, Mary; LoGiudice, Kathleen; Kenneth A Schmidt; Ostfeld, Richard S.

    2014-01-01

    Anaplasmosis is an emerging infectious disease caused by infection with the bacterium Anaplasma phagocytophilum. In the eastern United States, A. phagocytophilum is transmitted to hosts through the bite of the blacklegged tick, Ixodes scapularis. We determined the realized reservoir competence of 14 species of common vertebrate hosts for ticks by establishing the probability that each species transmits two important strains of A. phagocytophilum (A. phagocytophilum human-active, which causes ...

  19. Morphological change in Newfoundland caribou: Effects of abundance and climate

    Directory of Open Access Journals (Sweden)

    Shane P. Mahoney

    2011-04-01

    Full Text Available The demographic and environmental influences on large mammal morphology are central questions in ecology. We investigated the effects of population abundance and climate on body size and number of male antler points for the La Poile and Middle Ridge caribou (Rangifer tarandus, L. 1758 herds, Newfoundland, Canada. Across 40 years and 20-fold changes in abundance, adult males and females exhibited diminished stature as indicated by jawbone size (diastema and total mandible length and the number of antler points at the time of harvest. Associations between jawbone size and population abundance at birth were consistently negative for both herds, both sexes, and all age classes. Large-scale climate patterns, as measured by the North Atlantic Oscillation in the winter prior to birth, were also negatively associated with jawbone size. Declines in male antler size, as measured by the number of antler points, were not well predicted by either abundance or climate, suggesting other factors (e.g., current, rather than latent, foraging conditions may be involved. We conclude that these morphological changes indicate competition for food resources.

  20. Beryllium abundances along the evolutionary sequence of the open cluster IC 4651 - New test for hydrodynamical stellar models

    CERN Document Server

    Smiljanic, Rodolfo; Charbonnel, Corinne; Lagarde, Nadege

    2009-01-01

    [abridged] Previous analyses of lithium abundances in main sequence and red giant stars have revealed the action of mixing mechanisms other than convection in stellar interiors. Beryllium abundances in stars with lithium abundance determinations can offer valuable complementary information on the nature of these mechanisms. Our aim is to derive beryllium abundances along the whole evolutionary sequence of an open cluster, IC 4651. These Be abundances are used together with previously determined Li abundances, in the same sample stars, to investigate the mixing mechanisms in a range of stellar masses and evolutionary stages. New beryllium abundances are determined from high-resolution, high signal-to-noise UVES spectra using spectrum synthesis and model atmospheres. The careful synthetic modelling of the Be lines region is used to calculate reliable abundances in rapidly rotating stars. The observed behavior of Be and Li is compared to theoretical predictions from stellar models including rotation-induced mixi...

  1. Taking species abundance distributions beyond individuals

    NARCIS (Netherlands)

    Morlon, Helene; White, Ethan P.; Etienne, Rampal S.; Green, Jessica L.; Ostling, Annette; Alonso, David; Enquist, Brian J.; He, Fangliang; Hurlbert, Allen; Magurran, Anne E.; Maurer, Brian A.; McGill, Brian J.; Olff, Han; Storch, David; Zillio, Tommaso; Chave, Jérôme

    2009-01-01

    The species abundance distribution (SAD) is one of the few universal patterns in ecology. Research on this fundamental distribution has primarily focused on the study of numerical counts, irrespective of the traits of individuals. Here we show that considering a set of Generalized Species Abundance

  2. Solar Energetic Particles: Sampling Coronal Abundances

    Science.gov (United States)

    Reames, Donald V.

    1998-05-01

    In the large solar energetic particle (SEP) events, coronal mass ejections (CMEs) drive shock waves out through the corona that accelerate elements of the ambient material to MeV energies in a fairly democratic, temperature-independent manner. These events provide the most complete source of information on element abundances in the corona. Relative abundances of 22 elements from H through Zn display the well-known dependence on the first ionization potential (FIP) that distinguishes coronal and photospheric material. For most elements, the main abundance variations depend upon the gyrofrequency, and hence on the charge-to-mass ratio, Q/A, of the ion. Abundance variations in the dominant species, H and He, are not Q/A dependent, presumably because of non-linear wave-particle interactions of H and He during acceleration. Impulsive flares provide a different sample of material that confirms the Ne:Mg:Si and He/C abundances in the corona.

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

    Directory of Open Access Journals (Sweden)

    Andrei Daniel Mihalca

    2013-10-01

    Full Text Available 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 I. 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 Ixodes ricinus.

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

    Directory of Open Access Journals (Sweden)

    Annapaola eRizzoli

    2014-12-01

    Full Text Available Tick-borne diseases represent major public and animal health issues worldwide. Ixodes ricinus, primarily associated with deciduous and mixed forests, is the principal vector of causative agents of viral, bacterial and protozoan zoonotic diseases in Europe. Recently, abundant tick populations have been observed in European urban green areas, which are of public health relevance due to exposure of humans and domesticated animals to potentially infected ticks. In urban habitats, small and medium sized mammals, birds, companion animals (dogs, cats and larger mammals (roe deer, wild boar play a role in maintenance of tick populations and as reservoirs of tick-borne pathogens. Presence of ticks infected with tick-borne encephalitis virus and high prevalence of ticks infected with Borrelia burgdorferi s.l., causing Lyme borreliosis, have been reported from urbanized areas in Europe. Emerging pathogens, including bacteria of the order Rickettsiales (Anaplasma phagocytophilum, 'Candidatus Neoehrlichia mikurensis', Rickettsia helvetica, R. monacensis, Borrelia miyamatoi and protozoans (Babesia divergens, B. venatorum and B. microti have also been detected in urban tick populations. Understanding the ecology of ticks and their associations with hosts in a European urbanized environment is crucial to quantify parameters necessary for risk pre-assessment and identification of public health strategies for control and prevention of tick-borne diseases.

  5. 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.

  6. Observation of an anomalous positron abundance in the cosmic radiation

    CERN Document Server

    Adriani, O; Bazilevskaya, G A; Bellotti, R; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bonvicini, V; Bottai, S; Bruno, A; Cafagna, F; Campana, D; Carlson, P; Casolino, M; Castellini, G; De Pascale, M P; De Rosa, G; De Simone, N; Di Felice, V; Galper, A M; Grishantseva, L; Hofverberg, P; Koldashov, S V; Krutkov, S Y; Kvashnin, A N; Leonov, A; Malvezzi, V; Marcelli, L; Menn, W; Mikhailov, V V; Mocchiutti, E; Orsi, S; Osteria, G; Papini, P; Pearce, M; Picozza, P; Ricci, M; Ricciarini, S B; Simon, M; Sparvoli, R; Spillantini, P; Stozhkov, Yu I; Vacchi, A; Vannuccini, E; Vasilyev, G; Voronov, S A; Yurkin, Y T; Zampa, G; Zampa, N; Zverev, V G

    2008-01-01

    Positrons are known to be produced in interactions between cosmic-ray nuclei and interstellar matter ("secondary production"). Positrons may, however, also be created by dark matter particle annihilations in the galactic halo or in the magnetospheres of near-by pulsars. The nature of dark matter is one of the most prominent open questions in science today. An observation of positrons from pulsars would open a new observation window on these sources. Here we present results from the PAMELA satellite experiment on the positron abundance in the cosmic radiation for the energy range 1.5 - 100 GeV. Our high energy data deviate significantly from predictions of secondary production models, and may constitute the first indirect evidence of dark matter particle annihilations, or the first observation of positron production from near-by pulsars. We also present evidence that solar activity significantly affects the abundance of positrons at low energies.

  7. New Insights on Jupiter's Deep Water Abundance from Disequilibrium Species

    CERN Document Server

    Wang, Dong; Lunine, Jonathan; Mousis, Olivier

    2014-01-01

    The bulk water abundance on Jupiter potentially constrains the planet's formation conditions. We improve the chemical constraints on Jupiter's deep water abundance in this paper. The eddy diffusion coefficient is used to model vertical mixing in planetary atmosphere, and based on laboratory studies dedicated to turbulent rotating convection, we propose a new formulation of the eddy diffusion coefficient for the troposphere of giant planets. The new formulation predicts a smooth transition from the slow rotation regime (near the equator) to the rapid rotation regime (near the pole). We estimate an uncertainty for the newly derived coefficient of less than 25$\\%$, which is much better than the one order of magnitude uncertainty used in the literature. We then reevaluate the water constraint provided by CO, using the newer eddy diffusion coefficient. We considered two updated CO kinetic models, one model constrains the water enrichment (relative to solar) between 0.1 and 0.75, while the other constrains the wate...

  8. Iron Abundance Diagnostics in High-Redshift QSOs

    CERN Document Server

    Corbin, M R; Freduling, N K W; Corbin, Michael R.; Korista, Kirk T.; Freduling, Nalaka Kodituwakku & Wolfram

    2004-01-01

    The abundance of alpha-process elements such as magnesium and carbon relative to iron measured from the broad emission lines of QSOs can serve as a diagnostic of the star formation and chemical enrichment histories of their host galaxies. We investigate the relationship between Fe/Mg and Fe/C abundance ratios and the resulting Fe II / Mg II 2800A and Fe II / 1900A-blend flux ratios, both of which have been measured in QSOs out to redshifts of approximately six. Using a galactic chemical evolution model based on a starburst in a giant elliptical galaxy, we find that these flux ratios are good tracers of the chemical enrichment of the nuclei. However, the values of these ratios measured in objects at redshifts of approximately six suggest that iron enrichment has occurred more rapidly in these objects than predicted by the assumed elliptical starburst model, under currently favored cosmologies.

  9. Review of Big Bang Nucleosynthesis and Primordial Abundances

    Science.gov (United States)

    Tytler, David; O'Meara, John M.; Suzuki, Nao; Lubin, Dan

    2001-03-01

    Big Bang Nucleosynthesis (BBN) is the synthesis of the light nuclei, Deuterium (D or 2H), 3He, 4He and 7Li during the first few minutes of the universe. This review concentrates on recent improvements in the measurement of the primordial (after BBN, and prior to modification) abundances of these nuclei. We mention improvement in the standard theory, and the non-standard extensions which are limited by the data. We have achieved an order of magnitude improvement in the precision of the measurement of primordial D/H, using the HIRES spectrograph on the W. M. Keck telescope to measure D in gas with very nearly primordial abundances towards quasars. From 1994 - 1996, it appeared that there could be a factor of ten range in primordial D/H, but today four examples of low D are secure. High D/H should be much easier to detect, and since there are no convincing examples, it must be extremely rare or non-existent. All data are consistent with a single low value for D/H, and the examples which are consistent with high D/H are readily interpreted as H contamination near the position of D. The new D/H measurements give the most accurate value for the baryon to photon ratio, η, and hence the cosmological baryon density. A similar density is required to explain the amount of Lyα absorption from neutral Hydrogen in the intergalactic medium (IGM) at redshift z ≃ 3, and to explain the fraction of baryons in local clusters of galaxies. The D/H measurements lead to predictions for the abundances of the other light nuclei, which generally agree with measurements. The remaining differences with some measurements can be explained by a combination of measurement and analysis errors or changes in the abundances after BBN. The measurements do not require physics beyond the standard BBN model. Instead, the agreement between the abundances is used to limit the non-standard physics. New measurements are giving improved understanding of the difficulties in estimating the abundances of all

  10. Silicon abundances in population I giants

    Science.gov (United States)

    Boehm-Vitense, Erika

    1992-01-01

    Silicon to carbon abundance ratios for population I giants were determined from emission lines originating in the transition layers between stellar chromospheres and coronae. For effective temperatures larger than 6200 K we find a group of stars with increased silicon to carbon but normal nitrogen to carbon abundance ratios. These stars are presumably descendents from Ap stars with increased surface silicon to carbon abundance ratios. For G stars this anomaly disappears as is to be expected due to the increased depth of the convection zone and therefore deeper mixing which dilutes the surface overabundances. The disappearance of the abundance anomalies proves that the anomalous abundances observed for the F giants are indeed only a surface phenomenon. It also proves that the same holds for their progenitors, the Ap and Am stars, as has been generally believed. Unexplained is the increased silicon to carbon abundance ratio observed for several stars cooler than 5100 L. RS CVn and related stars do not show this increased abundance ratio. There are also some giants which appear to be enriched in carbon, perhaps due to a helium flash with some mixing if the star is a clump star.

  11. Study of the primordial lithium abundance

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Lithium isotopes have attracted an intense interest because the abundance of both 6Li and 6Li from big bang nucleosynthesis (BBN) is one of the puzzles in nuclear astrophysics. Many investigations of both astrophysical observation and nucleosynthesis calculation have been carried out to solve the puzzle, but it is not solved yet. Several nuclear reactions involving lithium have been indirectly measured at China Institute of Atomic Energy, Beijing. The Standard BBN (SBBN) network calculations are then performed to investigate the primordial Lithium abundance. The result shows that these nuclear reactions have minimal effect on the SBBN abundances of 6Li and 7Li.

  12. Lithium Abundance of Metal-poor Stars

    Institute of Scientific and Technical Information of China (English)

    Hua-Wei Zhang; Gang Zhao

    2003-01-01

    High-resolution, high signal-to-noise ratio spectra have been obtained for 32 metal-poor stars. The equivalent widths of Li λ6708A were measured and the lithium abundances were derived. The average lithium abundance of 21 stars on the lithium plateau is 2.33±0.02 dex. The Lithium plateau exhibits a marginal trend along metallicity, dA(Li)/d[Fe/H] = 0.12±0.06, and no clear trend with the effective temperature. The trend indicates that the abundance of lithium plateau may not be primordial and that a part of the lithium was produced in Galactic Chemical Evolution (GCE).

  13. Direct Method Gas Phase Oxygen Abundances of 4 Lyman Break Analogs

    CERN Document Server

    Brown, Jonathan S; Pogge, Richard W

    2014-01-01

    We measure the gas-phase oxygen abundances in 4 Lyman Break Analogs (LBAs) using auroral emission lines to derive direct abundances. The direct method oxygen abundances of these objects are generally consistent with the empirically-derived strong-line method values, confirming that these objects are low oxygen abundance outliers from the Mass-Metallicity (MZ) relation defined by star forming SDSS galaxies. We find slightly anomalous excitation conditions (Wolf-Rayet features) that could potentially bias the empirical estimates towards high values if caution is not exercised in the selection of the strong-line calibration used. The high rate of star formation and low oxygen abundance of these objects is consistent with the predictions of the Fundamental Metallicity Relation (FMR), in which the infall of relatively unenriched gas simultaneously triggers an episode of star formation and dilutes ISM of the host galaxy.

  14. Lithium abundance/surface activity connections in solar-type Pleiades

    OpenAIRE

    Clarke, D.; MacDonald, E. C.; Owens, S.

    2004-01-01

    The relation between the lithium abundance, ALi, and photospheric activity of solar-type Pleiads is investigated for the first time via acquisition and analysis of B and V-band data. Predictions of activity levels of target stars were made according to the ALi/(B - V) relation and then compared with new CCD photometric measurements. Six sources behaved according to the predictions while one star (HII 676), with low predicted activity, exhibited the largest variability of the study; another st...

  15. Evaluation of solar radiation abundance and electricity production capacity for application and development of solar energy

    OpenAIRE

    Mustamin Rahim, Jun Yoshino, Takashi Yasuda

    2012-01-01

    This study was undertaken to analyze solar radiation abundance to ascertain the potential of solar energy as an electrical energy resource. Local weather forecasting for predicting solar radiation is performed using a meteorological model MM5. The prediction results are compared with observed results obtained from the Japan Meteorological Agency for verification of the data accuracy. Results show that local weather forecasting has high accuracy. Prediction of solar radiation is similar with o...

  16. Observational effects of magnetism in O stars: surface nitrogen abundances

    OpenAIRE

    Martins, F.; Escolano, C.; Wade, G. A.; Donati, J.-F.; Bouret, J. -C.; collaboration, the MiMeS

    2011-01-01

    We investigate the surface nitrogen content of the six magnetic O stars known to date as well as of the early B-type star tau Sco. We compare these abundances to predictions of evolutionary models to isolate the effects of magnetic field on the transport of elements in stellar interiors. We conduct a quantitative spectroscopic analysis of the sample stars with state-of-the-art atmosphere models. We rely on high signal-to-noise ratio, high resolution optical spectra obtained with ESPADONS at C...

  17. Iron abundance in the atmosphere of Arcturus

    CERN Document Server

    Sheminova, V A

    2015-01-01

    Abundance of iron in the atmosphere of Arcturus has been determined from the profiles or regions of the profiles of the weak lines sensitive to iron abundance. The selected lines of Fe I and Fe II were synthesized with the MARCS theoretical models of the atmosphere. From the observed profiles of lines available with a high spectral resolution in the atlas by Hinkle and Wallace (2005), the values of the iron abundance $A = 6.95 \\pm 0.03$ and the radial-tangential macroturbulent velocity $5.6 \\pm 0.2$ km/s were obtained for Arcturus. The same physical quantities were found for the Sun as a star; they are $7.42 \\pm 0.02$ and $3.4 \\pm 0.3$ km/s, respectively. For Arcturus, the iron abundance relative to the solar one was determined with the differential method as [Fe/H] $=-0.48 \\pm 0.02$.

  18. Chemical abundance analysis of 19 barium stars

    CERN Document Server

    Yang, G C; Spite, M; Chen, Y Q; Zhao, G; Zhang, B; Liu, G Q; Liu, Y J; Liu, N; Deng, L C; Spite, F; Hill, V; Zhang, C X

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures, surface gravities, metallicity and microturbulent velocity) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their light elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn and Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-ca...

  19. SWFSC/MMTD: Vaquita Abundance Survey 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1997, the Southwest Fisheries Science Center (SWFSC) conducted a survey designed to estimate the abundance of vaquita, the Gulf of California harbor porpoise...

  20. Chinook Abundance - Linear Features [ds181

    Data.gov (United States)

    California Department of Resources — The dataset 'ds181_Chinook_ln' is a product of the CalFish Adult Salmonid Abundance Database. Data in this shapefile are collected from stream sections or reaches...

  1. Abundance Distributions in Artificial Life and Stochastic Models: "Age and Area" revisited

    OpenAIRE

    Adami, C.; Brown, C. T.; Haggerty, M.

    1995-01-01

    Using an artificial system of self-replicating strings, we show a correlation between the age of a genotype and its abundance that reflects a punctuated rather than gradual picture of evolution, as suggested long ago by Willis. In support of this correlation, we measure genotype abundance distributions and find universal coefficients. Finally, we propose a simple stochastic model which describes the dynamics of equilibrium periods and which correctly predicts most of the observed distributions.

  2. Abundance distributions in artificial life and stochastic models "age and area" revisited

    CERN Document Server

    Adami, C; Haggerty, M; Brown, C T; Haggerty, M

    1995-01-01

    Using an artificial system of self-replicating strings, we show a correlation between the age of a genotype and its abundance that reflects a punctuated rather than gradual picture of evolution, as suggested long ago by Willis. In support of this correlation, we measure genotype abundance distributions and find universal coefficients. Finally, we propose a simple stochastic model which describes the dynamics of equilibrium periods and which correctly predicts most of the observed distributions.

  3. Modeling and Mapping Golden-winged Warbler Abundance to Improve Regional Conservation Strategies

    Directory of Open Access Journals (Sweden)

    Wayne E. Thogmartin

    2010-12-01

    Full Text Available Conservation planning requires identifying pertinent habitat factors and locating geographic locations where land management may improve habitat conditions for high priority species. I derived habitat models and mapped predicted abundance for the Golden-winged Warbler (Vermivora chrysoptera, a species of high conservation concern, using bird counts, environmental variables, and hierarchical models applied at multiple spatial scales. My aim was to understand habitat associations at multiple spatial scales and create a predictive abundance map for purposes of conservation planning for the Golden-winged Warbler. My models indicated a substantial influence of landscape conditions, including strong positive associations with total forest composition within the landscape. However, many of the associations I observed were counter to reported associations at finer spatial extents; for instance, I found Golden-winged Warblers negatively associated with several measures of edge habitat. No single spatial scale dominated, indicating that this species is responding to factors at multiple spatial scales. I found Golden-winged Warbler abundance was negatively related with Blue-winged Warbler (Vermivora cyanoptera abundance. I also observed a north-south spatial trend suggestive of a regional climate effect that was not previously noted for this species. The map of predicted abundance indicated a large area of concentrated abundance in west-central Wisconsin, with smaller areas of high abundance along the northern periphery of the Prairie Hardwood Transition. This map of predicted abundance compared favorably with independent evaluation data sets and can thus be used to inform regional planning efforts devoted to conserving this species.

  4. Quantitative plant ecology:statistical and ecological modelling of plant abundance

    OpenAIRE

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com)The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement and statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also mean...

  5. Primordial Deuterium Abundance and Cosmic Baryon Density

    OpenAIRE

    Hogan, Craig J.

    1994-01-01

    The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows determination of cosmic deuterium abundances in quasar absorption clouds at large redshift, allowing a new test of big bang homogeneity in diverse, very distant systems. The first results of these studies are summarized, along with their implications. The ...

  6. Estimating whale abundance using sparse hydrophone arrays

    OpenAIRE

    Harris, Danielle Veronica

    2012-01-01

    Passive acoustic monitoring has been used to investigate many aspects of marine mammal ecology, although methods to estimate absolute abundance and density using acoustic data have only been developed in recent years. The instrument configuration in an acoustic survey determines which abundance estimation methods can be used. Sparsely distributed arrays of instruments are useful because wide geographic areas can be covered. However, instrument spacing in sparse arrays is such that the same...

  7. Coronae of Stars with Supersolar Elemental Abundances

    Science.gov (United States)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  8. Spatial scaling of species abundance distributions

    OpenAIRE

    Borda-de-Água, Luís; Borges, Paulo A. V.; Hubbell, Stephen P.; Pereira, Henrique M

    2012-01-01

    Copyright © 2012 The Authors. Ecography © 2012 Nordic Society Oikos. Species abundance distributions are an essential tool in describing the biodiversity of ecological communities. We now know that their shape changes as a function of the size of area sampled. Here we analyze the scaling properties of species abundance distributions by using the moments of the logarithmically transformed number of individuals. We find that the moments as a function of area size are well fitted by power law...

  9. How selection structures species abundance distributions

    OpenAIRE

    Magurran, A.E; Henderson, P. A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in l...

  10. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    Science.gov (United States)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  11. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    Science.gov (United States)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  12. Report on carbon and nitrogen abundance studies

    Science.gov (United States)

    Boehm-Vitense, Erika

    1991-01-01

    The aim of the proposal was to determine the nitrogen to carbon abundance ratios from transition layer lines in stars with different T(sub eff) and luminosities. The equations which give the surface emission line fluxes and the measured ratio of the NV to CIV emission line fluxes are presented and explained. The abundance results are compared with those of photospheric abundance studies for stars in common with the photospheric investigations. The results show that the analyses are at least as accurate as the photospheric determinations. These studies can be extended to F and early G stars for which photospheric abundance determinations for giants are hard to do because molecular bands become too weak. The abundance determination in the context of stellar evolution is addressed. The N/C abundance ratio increases steeply at the point of evolution for which the convection zone reaches deepest. Looking at the evolution of the rotation velocities v sin i, a steep decrease in v sin i is related to the increasing depth of the convection zone. It is concluded that the decrease in v sin i for T(sub eff) less than or approximately = 5800 K is most probably due to the rearrangement of the angular momentum in the stars due to deep convective mixing. It appears that the convection zone is rotating with nearly depth independent angular momentum. Other research results and ongoing projects are discussed.

  13. Abundance determination of A, Am and F stars in the Pleiades and Coma Berenices clusters

    Science.gov (United States)

    Gebran, M.; Monier, R.; Richard, O.

    2008-04-01

    Abundances of 18 chemical elements have been derived for 27 A/Am and 16 F stars members of the Pleiades and Coma Berenices open clusters. We have specifically computed, with the Montrèal code, a series of evolutionary models for two A star members of these two clusters. None of the models reproduces entirely the overall shape of the abundance patterns. The inclusion of competing processes such as rotational mixing in the radiative zones of these stars seems necessary to improve the agreement between observed and predicted abundance patterns.

  14. Abundances determination of A, Am and F stars in the Pleiades and Coma Berenices clusters

    CERN Document Server

    Gebran, M; Richard, O

    2008-01-01

    Abundances of 18 chemical elements have been derived for 27 A/Am and 16 F stars members of the Pleiades and Coma Berenices open clusters. We have specifically computed, with the Montr\\'eal code, a series of evolutionary models for two A stars members of these two clusters. None of the models reproduces entirely the overall shape of the abundances patterns. The inclusion of competing processes such as rotational mixing in the radiative zones of these stars seems necessary to improve the agreement between observed and predicted abundances patterns.

  15. Chemical abundances in Galactic Planetary Nebulae with Spitzer spectra

    CERN Document Server

    Garcia-Hernandez, D A

    2014-01-01

    We present new low-resolution (R~800) optical spectra of 22 Galactic PNe with Spitzer spectra. These data are combined with recent optical spectroscopic data available in the literature to construct representative samples of compact (and presumably young) Galactic disc and bulge PNe with Spitzer spectra. Attending to the nature of the dust features seen in their Spitzer spectra, Galactic disc and bulge PNe are classified according to four major dust types (oxygen chemistry or OC, carbon chemistry or CC, double chemistry or DC, featureless or F) and subtypes (amorphous and crystalline, and aliphatic and aromatic). Nebular gas abundances of He, N, O, Ne, S, Cl and Ar, as well as plasma parameters (e.g. Ne, Te) are homogeneously derived and we study the median chemical abundances and nebular properties in Galactic disc and bulge PNe depending on their Spitzer dust types and subtypes. A comparison of the derived median abundance patterns with AGB nucleosynthesis predictions show mainly that: i) DC PNe, both with ...

  16. Bee Abundance and Nutritional Status in Relation to Grassland Management Practices in an Agricultural Landscape.

    Science.gov (United States)

    Smith, Griffin W; Debinski, Diane M; Scavo, Nicole A; Lange, Corey J; Delaney, John T; Moranz, Raymond A; Miller, James R; Engle, David M; Toth, Amy L

    2016-04-01

    Grasslands provide important resources for pollinators in agricultural landscapes. Managing grasslands with fire and grazing has the potential to benefit plant and pollinator communities, though there is uncertainty about the ideal approach. We examined the relationships among burning and grazing regimes, plant communities, and Bombus species and Apis mellifera L. abundance and nutritional indicators at the Grand River Grasslands in southern Iowa and northern Missouri. Treatment regimes included burn-only, grazed-and-burned, and patch-burn graze (pastures subdivided into three temporally distinct fire patches with free access by cattle). The premise of the experimental design was that patch-burn grazing would increase habitat heterogeneity, thereby providing more diverse and abundant floral resources for pollinators. We predicted that both bee abundance and individual bee nutritional indicators (bee size and lipid content) would be positively correlated with floral resource abundance. There were no significant differences among treatments with respect to bee abundance. However, some of the specific characteristics of the plant community showed significant relationships with bee response variables. Pastures with greater abundance of floral resources had greater bee abundance but lower bee nutritional indicators. Bee nutritional variables were positively correlated with vegetation height, but, in some cases, negatively correlated with stocking rate. These results suggest grassland site characteristics such as floral resource abundance and stocking rate are of potential importance to bee pollinators and suggest avenues for further research to untangle the complex interactions between grassland management, plant responses, and bee health.

  17. Host trait combinations drive abundance and canopy distribution of atmospheric bromeliad assemblages

    Science.gov (United States)

    Chaves, Cleber Juliano Neves; Dyonisio, Júlio César; Rossatto, Davi Rodrigo

    2016-01-01

    Epiphytes are strongly dependent on the conditions created by their host's traits and a certain degree of specificity is expected between them, even if these species are largely abundant in a series of tree hosts of a given environment, as in the case of atmospheric bromeliads. Despite their considerable abundance in these environments, we hypothesize that stochasticity alone cannot explain the presence and abundance of atmospheric bromeliads on host trees, since host traits could have a greater influence on the establishment of these bromeliads. We used secondary and reforested seasonal forests and three distinct silvicultures to test whether species richness, phylogenetic diversity and functional diversity of trees can predict the differential presence, abundance and distribution of atmospheric bromeliads on hosts. We compared the observed parameters of their assemblage with null models and performed successive variance hierarchic partitions of abundance and distribution of the assemblage to detect the influence of multiple traits of the tree hosts. Our results do not indicate direct relationships between the abundance of atmospheric bromeliads and phylogenetic or functional diversity of trees, but instead indicate that bromeliads occurred on fewer tree species than expected by chance. We distinguished functional tree patterns that can improve or reduce the abundance of atmospheric bromeliads, and change their distribution on branches and trunk. While individual tree traits are related to increased abundance, species traits are related to the canopy distribution of atmospheric bromeliad assemblages. A balance among these tree functional patterns drives the atmospheric bromeliad assemblage of the forest patches. PMID:26888951

  18. Comparisons of picophytoplankton abundance, size, and fluorescence between summer and winter in northern South China Sea

    Science.gov (United States)

    Chen, Bingzhang; Wang, Lei; Song, Shuqun; Huang, Bangqin; Sun, Jun; Liu, Hongbin

    2011-09-01

    The abundance, size, and fluorescence of picophytoplankton cells were investigated during the summer (July-August of 2009) and winter (January of 2010) extending from near-shore coastal waters to oligotrophic open waters in northern South China Sea, under the influence of contrasting seasonal monsoons. We found that the median abundance of Prochlorococcus averaged over top 150 m decreased nearly 10 times in the winter compared to the summer in the whole survey area, while median abundance of Synechococcus and picoeukaryotes increased 2.6 and 2.4 folds, respectively. Vertical abundance profiles of picoeukaryotes usually formed a subsurface maximum during the summer with the depth of maximal abundances tracking the depth of nutricline, whereas their vertical distributions were more uniform during the winter. Size and cellular fluorescence of Prochlorococcus and Synechococcus usually increased with depth in the summer, while the size of picoeukaryotes was smallest at the depth of maximal abundances. Size, cellular fluorescence, and chlorophyll-to-carbon ratio of Prochlorococcus and Synechococcus in surface waters were generally higher in the winter than in the summer and onshore than offshore, probably resulting from different temperature, nutrient, and light environments as well as different ecotype compositions. Prochlorococcus cells were most abundant in warm and oligotrophic environments, while the abundance of Synechococcus and picoeukaryotes was the highest in waters with intermediate chlorophyll and nutrient concentrations. The distributional patterns of picophytoplankton groups are consistent with their specific physiology documented in previous studies and can be possibly predicted by environmental physical and chemical variables.

  19. Predictors of leafhopper abundance and richness in a coffee agroecosystem in Chiapas, Mexico.

    Science.gov (United States)

    Burdine, Justin D; Domínguez Martínez, Gabriel H; Philpott, Stacy M

    2014-04-01

    Coffee agroecosystems with a vegetatively complex shade canopy contain high levels of biodiversity. However, as coffee management is intensified, diversity may be lost. Most biodiversity studies in coffee agroecosystems have examined predators and not herbivores, despite their importance as potential coffee pests and coffee disease vectors. We sampled one abundant herbivore group of leafhoppers on an organic coffee farm in Chiapas, Mexico. We sampled leafhoppers with elevated pan traps in high- and moderate-shade coffee during the dry and wet seasons of 2011. The two major objectives were to 1) compare leafhopper abundance and richness during the wet and dry seasons and 2) examine the correlations between habitat characteristics (e.g., vegetation, elevation, and presence of aggressive ants) and leafhopper richness and abundance. We collected 2,351 leafhoppers, representing eight tribes and 64 morphospecies. Leafhopper abundance was higher in the dry season than in the wet season. Likewise, leafhopper richness was higher in the dry season. Several vegetation and other habitat characteristics correlated with abundance and richness of leafhoppers. The number of Inga trees positively correlated with leafhopper abundance, and other significant correlates of abundance included vegetation complexity. Leafhopper richness was correlated with the number of Inga trees. As leafhoppers transmit important coffee diseases, understanding the specific habitat factors correlating with changes in abundance and richness may help predict future disease outbreaks.

  20. Chemical abundances of blue straggler stars in Galactic Globular Clusters

    CERN Document Server

    Lovisi, L

    2014-01-01

    By using the high resolution spectrograph FLAMES@VLT we performed the first systematic campaign devoted to measure chemical abundances of blue straggler stars (BSSs). These stars, whose existence is not predicted by the canonical stellar evolutionary theory, are likely the product of the interactions between stars in the dense environment of Globular Clusters. Two main scenarios for BSS formation (mass transfer in binary systems and stellar collisions) have been proposed and hydrodynamical simulations predict different chemical patterns in the two cases, in particular C and O depletion for mass transfer BSSs. In this contribution, the main results for BSS samples in 6 Globular Clusters and their interpretation in terms of BSS formation processes are discussed. For the first time, evidence of radiative levitation in the shallow envelopes of BSSs hotter than $\\sim$8000 K has been found. C and O depletion for some BSSs has been detected in 47 Tucanae, M30 and $\\omega$ Centauri thus suggesting a mass transfer ori...

  1. Apparent competition drives community-wide parasitism rates and changes in host abundance across ecosystem boundaries.

    Science.gov (United States)

    Frost, Carol M; Peralta, Guadalupe; Rand, Tatyana A; Didham, Raphael K; Varsani, Arvind; Tylianakis, Jason M

    2016-01-01

    Species have strong indirect effects on others, and predicting these effects is a central challenge in ecology. Prey species sharing an enemy (predator or parasitoid) can be linked by apparent competition, but it is unknown whether this process is strong enough to be a community-wide structuring mechanism that could be used to predict future states of diverse food webs. Whether species abundances are spatially coupled by enemy movement across different habitats is also untested. Here, using a field experiment, we show that predicted apparent competitive effects between species, mediated via shared parasitoids, can significantly explain future parasitism rates and herbivore abundances. These predictions are successful even across edges between natural and managed forests, following experimental reduction of herbivore densities by aerial spraying of insecticide over 20 hectares. This result shows that trophic indirect effects propagate across networks and habitats in important, predictable ways, with implications for landscape planning, invasion biology and biological control. PMID:27577948

  2. Ecogenomics and biogeochemical impacts of uncultivated globally abundant ocean viruses

    KAUST Repository

    Roux, Simon

    2016-05-12

    Ocean microbes drive global-scale biogeochemical cycling, but do so under constraints imposed by viruses on host community composition, metabolism, and evolutionary trajectories. Due to sampling and cultivation challenges, genome-level viral diversity remains poorly described and grossly understudied in nature such that <1% of observed surface ocean viruses, even those that are abundant and ubiquitous, are ?known?. Here we analyze a global map of abundant, double stranded DNA (dsDNA) viruses and viral-encoded auxiliary metabolic genes (AMGs) with genomic and ecological contexts through the Global Ocean Viromes (GOV) dataset, which includes complete genomes and large genomic fragments from both surface and deep ocean viruses sampled during the Tara Oceans and Malaspina research expeditions. A total of 15,222 epi- and mesopelagic viral populations were identified that comprised 867 viral clusters (VCs, approximately genus-level groups). This roughly triples known ocean viral populations, doubles known candidate bacterial and archaeal virus genera, and near-completely samples epipelagic communities at both the population and VC level. Thirty-eight of the 867 VCs were identified as the most impactful dsDNA viral groups in the oceans, as these were locally or globally abundant and accounted together for nearly half of the viral populations in any GOV sample. Most of these were predicted in silico to infect dominant, ecologically relevant microbes, while two thirds of them represent newly described viruses that lacked any cultivated representative. Beyond these taxon-specific ecological observations, we identified 243 viral-encoded AMGs in GOV, only 95 of which were known. Deeper analyses of 4 of these AMGs revealed that abundant viruses directly manipulate sulfur and nitrogen cycling, and do so throughout the epipelagic ocean. Together these data provide a critically-needed organismal catalog and functional context to begin meaningfully integrating viruses into

  3. Predictability of Conversation Partners

    Science.gov (United States)

    Takaguchi, Taro; Nakamura, Mitsuhiro; Sato, Nobuo; Yano, Kazuo; Masuda, Naoki

    2011-08-01

    Recent developments in sensing technologies have enabled us to examine the nature of human social behavior in greater detail. By applying an information-theoretic method to the spatiotemporal data of cell-phone locations, [C. Song , ScienceSCIEAS0036-8075 327, 1018 (2010)] found that human mobility patterns are remarkably predictable. Inspired by their work, we address a similar predictability question in a different kind of human social activity: conversation events. The predictability in the sequence of one’s conversation partners is defined as the degree to which one’s next conversation partner can be predicted given the current partner. We quantify this predictability by using the mutual information. We examine the predictability of conversation events for each individual using the longitudinal data of face-to-face interactions collected from two company offices in Japan. Each subject wears a name tag equipped with an infrared sensor node, and conversation events are marked when signals are exchanged between sensor nodes in close proximity. We find that the conversation events are predictable to a certain extent; knowing the current partner decreases the uncertainty about the next partner by 28.4% on average. Much of the predictability is explained by long-tailed distributions of interevent intervals. However, a predictability also exists in the data, apart from the contribution of their long-tailed nature. In addition, an individual’s predictability is correlated with the position of the individual in the static social network derived from the data. Individuals confined in a community—in the sense of an abundance of surrounding triangles—tend to have low predictability, and those bridging different communities tend to have high predictability.

  4. The iron abundance of the Magellanic Bridge

    CERN Document Server

    Dufton, P L; Thompson, H M A; Street, R A

    2008-01-01

    High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.5 dex. This may be due to systematic errors possibly arising from non-LTE effects or from errors in the atomic data as similar low Fe abundances having previously been reported from the analysis of the ultra-violet spectra of Galactic early-type stars. The iron abundance estimates for all three Bridge targets appear to be significantly lower than those found for the SMC and LMC by approximately -0.5 dex and -0.8 dex respectively and these differential results should not be affected by any systematic errors present in the absolute abundance estimates. These differential iron abundance estimates are consistent with the underabundances for C, N, O, Mg and Si of approximately -1.1 dex relative to our...

  5. Oxygen abundance maps of CALIFA galaxies

    CERN Document Server

    Zinchenko, I A; Grebel, E K; Sanchez, S F; Vilchez, J M

    2016-01-01

    We construct maps of the oxygen abundance distribution across the disks of 88 galaxies using CALIFA data release 2 (DR2) spectra. The position of the center of a galaxy (coordinates on the plate) were also taken from the CALIFA DR2. The galaxy inclination, the position angle of the major axis, and the optical radius were determined from the analysis of the surface brightnesses in the SDSS $g$ and $r$ bands of the photometric maps of SDSS data release 9. We explore the global azimuthal abundance asymmetry in the disks of the CALIFA galaxies and the presence of a break in the radial oxygen abundance distribution. We found that there is no significant global azimuthal asymmetry for our sample of galaxies, i.e., the asymmetry is small, usually lower than 0.05 dex. The scatter in oxygen abundances around the abundance gradient has a comparable value, $\\lesssim 0.05$ dex. A significant (possibly dominant) fraction of the asymmetry can be attributed to the uncertainties in the geometrical parameters of these galaxie...

  6. Good abundances from bad spectra; 1, techniques

    CERN Document Server

    Bryn, J; Wyse, R F G; Gilmore, Gerard; Wyse, Rosemary F G

    1995-01-01

    We have developed techniques to extract true iron abundances and surface gravities from spectra of the type provided by the multiple-object fibre-fed spectroscopic radial-velocity surveys underway with 2dF, HYDRA, NESSIE, and the forthcoming Sloan survey. Our method is optimised for low S/N, intermediate resolution blue spectra of G stars. Spectroscopic indices sensitive to iron abundance and gravity are defined from a set of narrow (few Angstrom) wavelength intervals, and calibrated using synthetic spectra. We have also defined a single abundance indicator which is able to provide useful iron abundance information from spectra having S/N ratios as low as 10 per Angstrom. The theoretical basis and calibration using synthetic spectra are described in this paper. The empirical calibration of these techniques by application to observational data is described in Jones, Wyse and Gilmore (PASP July 1995). The technique provides precise iron abundances, with zero-point correct to \\sim 0.1 dex, and is reliable, with ...

  7. Why is Trichodesmium abundant in the Kuroshio?

    Science.gov (United States)

    Shiozaki, T.; Takeda, S.; Itoh, S.; Kodama, T.; Liu, X.; Hashihama, F.; Furuya, K.

    2015-12-01

    The genus Trichodesmium is recognized as an abundant and major diazotroph in the Kuroshio, but the reason for this remains unclear. The present study investigated the abundance of Trichodesmium spp. and nitrogen fixation together with concentrations of dissolved iron and phosphate in the Kuroshio and its marginal seas. We performed the observations near the Miyako Islands, which form part of the Ryukyu Islands, situated along the Kuroshio, since our satellite analysis suggested that material transport could occur from the islands to the Kuroshio. Trichodesmium spp. bloomed (> 20 000 filaments L-1) near the Miyako Islands, abundance was high in the Kuroshio and the Kuroshio bifurcation region of the East China Sea, but was low in the Philippine Sea. The abundance of Trichodesmium spp. was significantly correlated with the total nitrogen fixation activity. The surface concentrations of dissolved iron (0.19-0.89 nM) and phosphate (differences in Trichodesmium spp. abundance and nitrogen fixation. Numerical particle-tracking experiments simulated the transportation of water around the Ryukyu Islands to the Kuroshio. Our results indicate that Trichodesmium growing around the Ryukyu Islands could be advected into the Kuroshio.

  8. Abundances of Molecular Species in Barnard 68

    CERN Document Server

    Francesco, J D; Welch, W J; Bergin, E A; Francesco, James Di; Hogerheijde, Michiel R.; Welch, William J.; Bergin, Edwin A.

    2002-01-01

    Abundances for 5 molecules (C18O, CS, NH3, H2CO, and C3H2) and 1 molecular ion (N2H+) and upper limits for the abundances of 1 molecule (13CO) and 1 molecular ion (HCO+) are derived for gas within the Bok globule Barnard 68 (B68). The abundances were determined using our own BIMA millimeter interferometer data and single-dish data gathered from the literature, in conjunction with a Monte Carlo radiative transfer model. Since B68 is the only starless core to have its density structure strongly constrained via extinction mapping, a major uncertainty has been removed from these determinations. All abundances for B68 are lower than those derived for translucent and cold dense clouds, but perhaps only significantly for N2H+, NH3, and C3H2. Depletion of CS toward the extinction peak of B68 is hinted at by the large offset between the extinction peak and the position of maximum CS line brightness. Abundances derived here for C18O and N2H+ are consistent with other, recently determined values at positions observed in...

  9. CHAOS III: Gas-phase Abundances in NGC 5457

    Science.gov (United States)

    Croxall, Kevin V.; Pogge, Richard W.; Berg, Danielle A.; Skillman, Evan D.; Moustakas, John

    2016-10-01

    We present Large Binocular Telescope observations of 109 H ii regions in NGC 5457 (M101) obtained with the Multi-Object Double Spectrograph. We have robust measurements of one or more temperature-sensitive auroral emission lines for 74 H ii regions, permitting the measurement of “direct” gas-phase abundances. Comparing the temperatures derived from the different ionic species, we find: (1) strong correlations of T[N ii] with T[S iii] and T[O iii], consistent with little or no intrinsic scatter; (2) a correlation of T[S iii] with T[O iii], but with significant intrinsic dispersion; (3) overall agreement between T[N ii], T[S ii], and T[O ii], as expected, but with significant outliers; (4) the correlations of T[N ii] with T[S iii] and T[O iii] match the predictions of photoionization modeling while the correlation of T[S iii] with T[O iii] is offset from the prediction of photoionization modeling. Based on these observations, which include significantly more observations of lower excitation H ii regions, missing in many analyses, we inspect the commonly used ionization correction factors (ICFs) for unobserved ionic species and propose new empirical ICFs for S and Ar. We have discovered an unexpected population of H ii regions with a significant offset to low values in Ne/O, which defies explanation. We derive radial gradients in O/H and N/O which agree with previous studies. Our large observational database allows us to examine the dispersion in abundances, and we find intrinsic dispersions of 0.074 ± 0.009 in O/H and 0.095 ± 0.009 in N/O (at a given radius). We stress that this measurement of the intrinsic dispersion comes exclusively from direct abundance measurements of H ii regions in NGC 5457.

  10. Temporal evolution of 36Cl abundances in the Great Lakes

    International Nuclear Information System (INIS)

    The observed 36Cl isotopic abundance in Great Lakes water decreases from west to east, with the highest 36Cl/Cl ratio of 1332 × 10−15 in Lake Superior and the lowest 36Cl/Cl ratio of 151 × 10−15 in Lake Erie, whereas the 36Cl concentration (36Cl atoms/L) is lowest in Lake Superior and higher in the other Great Lakes. The 36Cl concentration in Lake Superior is much higher than expected from normal atmospheric deposition over the basin, consistent with deposition of nuclear bomb-produced 36Cl during 1952–1964. A conservative mass-balance model constrained by hydrological parameters and available 36Cl fluence measurements predicts the 36Cl abundances in the Great Lakes from 1945 to 2015, in excellent agreement with available data for Lakes Superior, Michigan, and Huron, but the model underestimates 36Cl abundances for Lakes Erie and Ontario. However, assuming that 36Cl demonstrates non-conservative behavior and is significantly retained in the drainage basins, a model incorporating a delayed input parameter successfully predicts observed 36Cl concentrations in all of the Great Lakes. - Highlights: • 36Cl/Cl ratios are the highest in Lake Superior and the lowest in Lake Erie. • 36Cl concentrations in the Great Lakes are much higher than expected natural values. • Conservative 36Cl model underestimates observed values in Lakes Erie and Ontario. • Large fraction of 36Cl atoms deposited on the watersheds are retained for decades

  11. Habitat filtering and niche differentiation jointly explain species relative abundance within grassland communities along fertility and disturbance gradients.

    OpenAIRE

    Maire, Vincent; Gross, Nicolas; BORGER, Luca; Proulx, Raphaël; Wirth, Christian; Da Silveira Pontes, Laise; Soussana, Jean-François; Louault, Frédérique

    2012-01-01

    Deterministic niche-based processes have been proposed to explain species relative abundance within communities but lead to different predictions: habitat filtering (HF) predicts dominant species to exhibit similar traits while niche differentiation (ND) requires that species have dissimilar traits to coexist. Using a multiple trait-based approach, we evaluated the relative roles of HF and ND in determining species abundances in productive grasslands. Four dimensions of the functional niche o...

  12. Chemical Fractionation and Abundances in Coronal Plasma

    CERN Document Server

    Drake, J J

    2003-01-01

    Much of modern astrophysics is grounded on the observed chemical compositions of stars and the diffuse plasma that pervades the space between stars, galaxies and clusters of galaxies. X-ray and EUV spectra of the hot plasma in the outer atmospheres of stars have demonstrated that these environments are subject to chemical fractionation in which the abundances of elements can be enhanced and depleted by an order of magnitude or more. These coronal abundance anomalies are discussed and some of the physical mechanisms that might be responsible for producing them are examined. It is argued that coronal abundances can provide important new diagnostics on physical processes at work in solar and stellar coronae. It seems likely that other hot astrophysical plasmas will be subject to similar effects.

  13. Modelling community dynamics based on species-level abundance models from detection/nondetection data

    Science.gov (United States)

    Yamaura, Yuichi; Royle, J. Andrew; Kuboi, Kouji; Tada, Tsuneo; Ikeno, Susumu; Makino, Shun'ichi

    2011-01-01

    1. In large-scale field surveys, a binary recording of each species' detection or nondetection has been increasingly adopted for its simplicity and low cost. Because of the importance of abundance in many studies, it is desirable to obtain inferences about abundance at species-, functional group-, and community-levels from such binary data. 2. We developed a novel hierarchical multi-species abundance model based on species-level detection/nondetection data. The model accounts for the existence of undetected species, and variability in abundance and detectability among species. Species-level detection/nondetection is linked to species- level abundance via a detection model that accommodates the expectation that probability of detection (at least one individuals is detected) increases with local abundance of the species. We applied this model to a 9-year dataset composed of the detection/nondetection of forest birds, at a single post-fire site (from 7 to 15 years after fire) in a montane area of central Japan. The model allocated undetected species into one of the predefined functional groups by assuming a prior distribution on individual group membership. 3. The results suggest that 15–20 species were missed in each year, and that species richness of communities and functional groups did not change with post-fire forest succession. Overall abundance of birds and abundance of functional groups tended to increase over time, although only in the winter, while decreases in detectabilities were observed in several species. 4. Synthesis and applications. Understanding and prediction of large-scale biodiversity dynamics partly hinge on how we can use data effectively. Our hierarchical model for detection/nondetection data estimates abundance in space/time at species-, functional group-, and community-levels while accounting for undetected individuals and species. It also permits comparison of multiple communities by many types of abundance-based diversity and similarity

  14. North Sea Elasmobranchs: distribution, abundance and biodiversity

    NARCIS (Netherlands)

    Daan, N.; Heessen, H.J.L.; Hofstede, ter R.

    2005-01-01

    Based on data from various international and national surveys, an overview is given of the fine-scale distribution (resolution of 20¿longitude * 10¿ latitude; ¿ 10*10 nm) and trends in abundance of elasmobranch species reported from the North Sea. Presence-absence maps are produced based on 4 survey

  15. The Galactic Thick Disk Stellar Abundances

    CERN Document Server

    Prochaska, J X; Carney, B W; McWilliam, A; Wolfe, A M; Prochaska, Jason X.; Naumov, Sergei O.; Carney, Bruce W.; William, Andrew Mc; Wolfe, Arthur M.

    2000-01-01

    We present first results from a program to measure the chemical abundances of a large (N>30) sample of thick disk stars with the principal goal of investigating the formation history of the Galactic thick disk. Our analysis confirms previous studies of O and Mg in the thick disk stars which reported enhancements in excess of the thin disk population. Furthermore, the observations of Si, Ca, Ti, Mn, Co, V, Zn, Al, and Eu all argue that the thick disk population has a distinct chemical history from the thin disk. With the exception of V and Co, the thick disk abundance patterns match or tend towards the values observed for halo stars with [Fe/H]~-1. This suggests that the thick disk stars had a chemical enrichment history similar to the metal-rich halo stars. With the possible exception of Si, the thick disk abundance patterns are in excellent agreement with the chemical abundances observed in the metal-poor bulge stars suggesting the two populations formed from the same gas reservoir at a common epoch. We disc...

  16. Nitrous Oxide Production by Abundant Benthic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

  17. The Abundance of Large Arcs From CLASH

    Science.gov (United States)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Coe, Dan A.; Clash Team

    2015-01-01

    We have developed an automated arc-finding algorithm to perform a rigorous comparison of the observed and simulated abundance of large lensed background galaxies (a.k.a arcs). We use images from the CLASH program to derive our observed arc abundance. Simulated CLASH images are created by performing ray tracing through mock clusters generated by the N-body simulation calibrated tool -- MOKA, and N-body/hydrodynamic simulations -- MUSIC, over the same mass and redshift range as the CLASH X-ray selected sample. We derive a lensing efficiency of 15 ± 3 arcs per cluster for the X-ray selected CLASH sample and 4 ± 2 arcs per cluster for the simulated sample. The marginally significant difference (3.0 σ) between the results for the observations and the simulations can be explained by the systematically smaller area with magnification larger than 3 (by a factor of ˜4) in both MOKA and MUSIC mass models relative to those derived from the CLASH data. Accounting for this difference brings the observed and simulated arc statistics into full agreement. We find that the source redshift distribution does not have big impact on the arc abundance but the arc abundance is very sensitive to the concentration of the dark matter halos. Our results suggest that the solution to the "arc statistics problem" lies primarily in matching the cluster dark matter distribution.

  18. Will Abundant Natural Gas Solve Climate Change?

    Science.gov (United States)

    McJeon, H. C.; Edmonds, J.; Bauer, N.; Leon, C.; Fisher, B.; Flannery, B.; Hilaire, J.; Krey, V.; Marangoni, G.; Mi, R.; Riahi, K.; Rogner, H.; Tavoni, M.

    2015-12-01

    The rapid deployment of hydraulic fracturing and horizontal drilling technologies enabled the production of previously uneconomic shale gas resources in North America. Global deployment of these advanced gas production technologies could bring large influx of economically competitive unconventional gas resources to the energy system. It has been hoped that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions, which in turn could reduce climate forcing. Other researchers countered that the non-CO2 greenhouse gas (GHG) emissions associated with shale gas production make its lifecycle emissions higher than those of coal. In this study, we employ five state-of-the-art integrated assessment models (IAMs) of energy-economy-climate systems to assess the full impact of abundant gas on climate change. The models show large additional natural gas consumption up to +170% by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2% to +11%), and a majority of the models reported a small increase in climate forcing (from -0.3% to +7%) associated with the increased use of abundant gas. Our results show that while globally abundant gas may substantially change the future energy market equilibrium, it will not significantly mitigate climate change on its own in the absence of climate policies.

  19. Abundance of Terrestrial Planets by Microlensing

    OpenAIRE

    Yock, Philip

    2000-01-01

    Terrestrial planets may be detected using the gravitational microlensing technique. This was demonstrated in the high magnification event MACHO-98-BLG-35. Observing strategies aimed at measuring the abundance of terrestrial planets are discussed, using both existing telescopes and planned telescopes.

  20. Chemical abundances in seven red giants of NGC 2360 and NGC 2447

    CERN Document Server

    Hamdani, S; Mowlavi, N; Raboud, D; Mermilliod, J C

    2000-01-01

    Chemical abundances of about fifteen elements from oxygen to europium are measured in seven red giants of the two open clusters NGC 2360 and NGC 2447. The effective temperatures of the giants are determined spectroscopically by taking advantage of their known masses (~2 Mo in NGC 2360 and ~3 Mo in NGC 2447) and bolometric magnitudes. The average iron abundances we obtain for the two clusters are [Fe/H]=0.07 for NGC 2360 and [Fe/H]=0.03 for NGC 2447. Evolutionary stellar model calculations are performed in the mass range 1-4 Mo in order to analyze the surface Na and O abundances predicted after the first dredge-up. The sodium abundance shows a well defined correlation with stellar mass in the 2-3 Mo range. The agreement between our Na abundance determinations in NGC 2360 and our model predictions at 2 Mo is very good. In contrast, the overabundance in one of the three stars in NGC 2447 exceeds that predicted at 3 Mo by ~0.08 dex, which is significant compared to the observational error bars. The effects of cor...

  1. The "Solar Model Problem" Solved by the Abundance of Neon in Stars of the Local Cosmos

    CERN Document Server

    Testa, J J D P

    2005-01-01

    The interior structure of the Sun can be studied with great accuracy using observations of its oscillations, similar to seismology of the Earth. Precise agreement between helioseismological measurements and predictions of theoretical solar models has been a triumph of modern astrophysics (Bahcall et al. 2005). However, a recent downward revision by 25-35% of the solar abundances of light elements such as C, N, O and Ne (Asplund et al. 2004) has broken this accordance: models adopting the new abundances incorrectly predict the depth of the convection zone, the depth profiles of sound speed and density, and the helium abundance (Basu Antia 2004, Bahcall et al. 2005). The discrepancies are far beyond the uncertainties in either the data or the model predictions (Bahcall et al. 2005b). Here we report on neon abundances relative to oxygen measured in a sample of nearby solar-like stars from their X-ray spectra. They are all very similar and substantially larger than the recently revised solar value. The neon abund...

  2. Non-Salmonid Abundance - Line Features [ds186

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. The "Other Fish" category contains data collected...

  3. Abundances in planetary nebulae: NGC 1535, NGC 6629, He2-108, and Tc1

    Science.gov (United States)

    Pottasch, S. R.; Surendiranath, R.; Bernard-Salas, J.

    2011-07-01

    Context. Models have been made of stars of a given mass that produce planetary nebulae that usually begin on the AGB (although they may begin earlier) and run to the white dwarf stage. While these models cover the so-called dredge-up phases when nuclear reactions occur and the newly formed products are brought to the surface, it is important to compare the abundances predicted by the models with the abundances actually observed in PNe. Aims: The aim of the paper is to determine the abundances in a group of PNe with uniform morphological and kinematic properties. The PNe we discuss are circular with rather low-temperature central stars and are rather far from the galactic plane. We discuss the effect these abundances have on determining the evolution of the central stars of these PNe. Methods: The mid-infrared spectra of the planetary nebulae NGC 1535, NGC 6629, He2-108, and Tc1 (IC 1266) taken with the Spitzer Space Telescope are presented. These spectra were combined with the ultraviolet IUE spectra and with the spectra in the visual wavelength region to obtain complete, extinction-corrected spectra. The chemical composition of these nebulae is then found by directly calculating and adding individual ion abundances. For two of these PNe, we attempted to reproduce the observed spectrum by making a model nebula. This proved impossible for one of the nebulae and the reason for this is discussed. The resulting abundances are more accurate than earlier studies for several reasons, the most important is that inclusion of the far infrared spectra increases the number of observed ions and makes it possible to include the nebular temperature gradient in the abundance calculations. Results: The abundances of the above four PNe have been determined and compared to the abundances found in five other PNe with similar properties studied earlier. These abundances are further compared with values predicted by the models of Karakas (2003). From this comparison we conclude that the

  4. Chemical abundances and kinematics of barium stars

    Science.gov (United States)

    de Castro, D. B.; Pereira, C. B.; Roig, F.; Jilinski, E.; Drake, N. A.; Chavero, C.; Sales Silva, J. V.

    2016-07-01

    In this paper, we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scaleheight, radial velocities, abundances of the Na, Al, α-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local thermodynamic equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. We found that the metallicities, the temperatures and the surface gravities for barium stars cannot be represented by a single Gaussian distribution. The abundances of α-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anticorrelated with the metallicity. Our kinematical analysis showed that 90 per cent of the barium stars belong to the thin disc population. Based on their luminosities, none of the barium stars are luminous enough to be an asymptotic giant branch star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.

  5. Daily variation of zooplankton abundance and evenness in the Rosana reservoir, Brazil: biotic and abiotic inferences

    Directory of Open Access Journals (Sweden)

    Érica M. Takahashi

    2014-03-01

    Full Text Available The zooplankton community presents stochastic temporal fluctuation and heterogeneous spatial variation determined by the relationships among the organisms and environmental conditions. We predicted that the temporal and spatial zooplankton distribution is heterogeneous and discrete, respectively, and that the daily variation of most abundant species is related to environmental conditions, specifically the availability of resources. Zooplankton samples were collected daily at three sampling stations in a lateral arm of the Rosana Reservoir (SP/PR. The zooplankton did not present significant differences in abundance and evenness among sampling stations, but the temporal variation of these attributes was significant. Abiotic variables and algal resource availability have significantly explained the daily variation of the most abundant species (p<0.001, however, the species distribution makes inferences on biotic relationships between them. Thus, not only the food resource availability is influential on the abundance of principal zooplankton species, but rather a set of factors (abiotic variables and biotic relationships.

  6. A landscape analysis of cougar distribution and abundance in Montana, USA.

    Science.gov (United States)

    Riley, S J; Malecki, R A

    2001-09-01

    Recent growth in the distribution and abundance of cougars (Puma concolor) throughout western North America has created opportunities, challenges, and problems for wildlife managers and raises questions about what factors affect cougar populations. We present an analysis of factors thought to affect cougar distribution and abundance across the broad geographical scales on which most population management decisions are made. Our objectives were to: (1) identify and evaluate landscape parameters that can be used to predict the capability of habitats to support cougars, and (2) evaluate factors that may account for the recent expansion in cougar numbers. Habitat values based on terrain ruggedness and forested cover explained 73% of the variation in a cougar abundance index. Indices of cougar abundance also were spatially and temporally correlated with ungulate abundance. An increase in the number and total biomass of ungulate prey species is hypothesized to account for recent increases in cougars. Cougar populations in Montana are coping with land development by humans when other components of habitat and prey populations are sufficient. Our analysis provides a better understanding of what may have influenced recent growth in cougar distribution and abundance in Montana and, when combined with insights about stakeholder acceptance capacity, offers a basis for cougar management at broad scales. Long-term conservation of cougars necessitates a better understanding of ecosystem functions that affect prey distribution and abundance, more accurate estimates of cougar populations, and management abilities to integrate these components with human values. PMID:11531235

  7. Oxygen abundance distributions in six late-type galaxies based on SALT spectra of HII regions

    CERN Document Server

    Zinchenko, I A; Grebel, E K; Pilyugin, L S

    2015-01-01

    Spectra of 34 H II regions in the late-type galaxies NGC1087, NGC2967, NGC3023, NGC4030, NGC4123, and NGC4517A were observed with the South African Large Telescope (SALT). In all 34 H II regions, oxygen abundances were determined through the "counterpart" method (C method). Additionally, in two H II regions in which the auroral lines were detected oxygen abundances were measured through the classic Te method. We also estimated the abundances in our H II regions using the O3N2 and N2 calibrations and compared those with the C-based abundances. With these data we examined the radial abundance distributions in the disks of our target galaxies. We derived surface-brightness profiles and other characteristics of the disks (the surface brightness at the disk center and the disk scale length) in three photometric bands for each galaxy using publicly available photometric imaging data. The radial distributions of the oxygen abundances predicted by the relation between abundance and disk surface brightness in the W1 b...

  8. Symmetric and asymmetric planetary nebulae and the time variation of the radial abundance gradients

    Science.gov (United States)

    Maciel, W.; Costa, R. D. D.

    2014-04-01

    Planetary nebulae (PN) are excellent laboratories to study the chemical evolution of their host galaxies, especially concerning the radial abundance gradients and their time and spatial variations. Current chemical evolution models predict either some steepening or flattening of the abundance gradients with time, and PN can be useful in order to provide observational constraints on this issue. It is generally believed that asymmetrical nebulae, especially bipolars, are formed by younger, more massive progenitor stars, while symmetrical nebulae, such as the round and elliptical objects, are formed by older, less massive stars. As a consequence, if the abundance gradients change with time, some differences are expected between the gradients measured in symmetrical and asymmetrical nebulae. We have considered a large sample of well-studied galactic PN for which accurate abundances of O, S, Ne, and Ar are known, and for which a reliable morphological classification can be made. Average abundances and radial gradients of the ratios O/H, S/H, Ne/H and Ar/H were then determined for the main morphological classes, comprising B, E, R, and P nebulae. It is found that the average abundances of the younger objects are larger than those of the older nebulae, as expected on chemical evolution grounds, but the derived gradients are essentially the same within the uncertainties. It can then be concluded that the radial abundance gradients have not changed appreciably since the older progenitor stars were born, approximately 4 to 5 Gyr ago.

  9. A broad assessment of factors determining Culicoides imicola abundance: modelling the present and forecasting its future in climate change scenarios.

    Directory of Open Access Journals (Sweden)

    Pelayo Acevedo

    Full Text Available Bluetongue (BT is still present in Europe and the introduction of new serotypes from endemic areas in the African continent is a possible threat. Culicoides imicola remains one of the most relevant BT vectors in Spain and research on the environmental determinants driving its life cycle is key to preventing and controlling BT. Our aim was to improve our understanding of the biotic and abiotic determinants of C. imicola by modelling its present abundance, studying the spatial pattern of predicted abundance in relation to BT outbreaks, and investigating how the predicted current distribution and abundance patterns might change under future (2011-2040 scenarios of climate change according to the Intergovernmental Panel on Climate Change. C. imicola abundance data from the bluetongue national surveillance programme were modelled with spatial, topoclimatic, host and soil factors. The influence of these factors was further assessed by variation partitioning procedures. The predicted abundance of C. imicola was also projected to a future period. Variation partitioning demonstrated that the pure effect of host and topoclimate factors explained a high percentage (>80% of the variation. The pure effect of soil followed in importance in explaining the abundance of C. imicola. A close link was confirmed between C. imicola abundance and BT outbreaks. To the best of our knowledge, this study is the first to consider wild and domestic hosts in predictive modelling for an arthropod vector. The main findings regarding the near future show that there is no evidence to suggest that there will be an important increase in the distribution range of C. imicola; this contrasts with an expected increase in abundance in the areas where it is already present in mainland Spain. What may be expected regarding the future scenario for orbiviruses in mainland Spain, is that higher predicted C. imicola abundance may significantly change the rate of transmission of orbiviruses.

  10. Deuterium Abundance in Consciousness and Current Cosmology

    Science.gov (United States)

    Rauscher, Elizabeth A.

    We utilize the deuterium-hydrogen abundances and their role in setting limits on the mass and other conditions of cosmogenesis and cosmological evolution. We calculate the dependence of a set of physical variables such as density, temperature, energy mass, entropy and other physical variable parameters through the evolution of the universe under the Schwarzschild conditions as a function from early to present time. Reconciliation with the 3°K and missing mass is made. We first examine the Schwarzschild condition; second, the geometrical constraints of a multidimensional Cartesian space on closed cosmologies, and third we will consider the cosmogenesis and evolution of the universe in a multidimensional Cartesian space, obeying the Schwarzschild condition. Implications of this model for matter creation are made. We also examine experimental evidence for closed versus open cosmologies; x-ray detection of the "missing mass" density. Also the interstellar deuterium abundance, along with the value of the Hubble constant set a general criterion on the value of the curvature constant, k. Once the value of the Hubble constant, H is determined, the deuterium abundance sets stringent restrictions on the value of the curvature constant k by an detailed discussion is presented. The experimental evidences for the determination of H and the primary set of coupled equations to determine D abundance is given. 'The value of k for an open, closed, or flat universe will be discussed in terms of the D abundance which will affect the interpretation of the Schwarzschild, black hole universe. We determine cosmology solutions to Einstein's field obeying the Schwarzschild solutions condition. With this model, we can form a reconciliation of the black hole, from galactic to cosmological scale. Continuous creation occurs at the dynamic blackhole plasma field. We term this new model the multiple big bang or "little whimper model". We utilize the deuteriumhydrogen abundances and their role in

  11. Chemical abundance analysis of 19 barium stars

    Science.gov (United States)

    Yang, Guo-Chao; Liang, Yan-Chun; Spite, Monique; Chen, Yu-Qin; Zhao, Gang; Zhang, Bo; Liu, Guo-Qing; Liu, Yu-Juan; Liu, Nian; Deng, Li-Cai; Spite, Francois; Hill, Vanessa; Zhang, Cai-Xia

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-capture) process elements relative to the Sun. Their median abundances of [Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe]. For the n-capture elements (Y, Zr, Ba, La), there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe] >0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17<[Ba/Fe] <0.54.

  12. iReckon: simultaneous isoform discovery and abundance estimation from RNA-seq data.

    Science.gov (United States)

    Mezlini, Aziz M; Smith, Eric J M; Fiume, Marc; Buske, Orion; Savich, Gleb L; Shah, Sohrab; Aparicio, Sam; Chiang, Derek Y; Goldenberg, Anna; Brudno, Michael

    2013-03-01

    High-throughput RNA sequencing (RNA-seq) promises to revolutionize our understanding of genes and their role in human disease by characterizing the RNA content of tissues and cells. The realization of this promise, however, is conditional on the development of effective computational methods for the identification and quantification of transcripts from incomplete and noisy data. In this article, we introduce iReckon, a method for simultaneous determination of the isoforms and estimation of their abundances. Our probabilistic approach incorporates multiple biological and technical phenomena, including novel isoforms, intron retention, unspliced pre-mRNA, PCR amplification biases, and multimapped reads. iReckon utilizes regularized expectation-maximization to accurately estimate the abundances of known and novel isoforms. Our results on simulated and real data demonstrate a superior ability to discover novel isoforms with a significantly reduced number of false-positive predictions, and our abundance accuracy prediction outmatches that of other state-of-the-art tools. Furthermore, we have applied iReckon to two cancer transcriptome data sets, a triple-negative breast cancer patient sample and the MCF7 breast cancer cell line, and show that iReckon is able to reconstruct the complex splicing changes that were not previously identified. QT-PCR validations of the isoforms detected in the MCF7 cell line confirmed all of iReckon's predictions and also showed strong agreement (r(2) = 0.94) with the predicted abundances. PMID:23204306

  13. Interdependence of environmental parameters and sand dwelling benthic species abundance: a multivariate approach

    Digital Repository Service at National Institute of Oceanography (India)

    Harkantra, S.N.; Parulekar, A.H.

    0.001). It is postulated that one can predict the occurrence of species and their abundance at a tropical beach under given condition and time at given place, provided there is no disturbance factor (s)-pollution and/or human interference....

  14. Relative abundance determinations in extremely metal poor giants. II. Transition probabilities and the abundance determinations

    International Nuclear Information System (INIS)

    The abundances of Fe and other elements are determined for a star of intermediate metallicity and for nine extremely metal poor stars, including two members of the globular cluster M92 and CD -38 deg 245. The accuracy of the transition probabilities for Fe I and other elements is evaluated. The distribution of the abundances of other elements with respect to Fe is the same for most of the cases studied. Manganese is the only element that shows a different relative abundance in an extremely metal poor star. 120 refs

  15. NLTE strontium abundance in a sample of extremely metal poor stars and the Sr/Ba ratio in the early Galaxy

    CERN Document Server

    Andrievsky, S M; Korotin, S A; Francois, P; Spite, M; Bonifacio, P; Cayrel, R; Hill, V

    2011-01-01

    Heavy element abundances in extremely metal-poor stars provide strong constraints on the processes of forming these elements in the first stars. We attempt to determine precise abundances of strontium in a homogeneous sample of extremely metal-poor stars. The abundances of strontium in 54 very or extremely metal-poor stars, was redetermined by abandoning the local thermodynamic equilibrium (LTE) hypothesis, and fitting non-LTE (NLTE) profiles to the observed spectral lines. The corrected Sr abundances and previously obtained NLTE Ba abundances are compared to the predictions of several hypothetical formation processes for the lighter neutron-capture elements. Our NLTE abundances confirm the previously determined huge scatter of the strontium abundance in low metallicity stars. This scatter is also found (and is even larger) at very low metallicities (i. e. early in the chemical evolution). The Sr abundance in the extremely metal-poor (EMP) stars is compatible with the main r-process involved in other processe...

  16. Earth Abundant Element Type I Clathrate Phases

    Directory of Open Access Journals (Sweden)

    Susan M. Kauzlarich

    2016-08-01

    Full Text Available Earth abundant element clathrate phases are of interest for a number of applications ranging from photovoltaics to thermoelectrics. Silicon-containing type I clathrate is a framework structure with the stoichiometry A8-xSi46 (A = guest atom such as alkali metal that can be tuned by alloying and doping with other elements. The type I clathrate framework can be described as being composed of two types of polyhedral cages made up of tetrahedrally coordinated Si: pentagonal dodecahedra with 20 atoms and tetrakaidecahedra with 24 atoms in the ratio of 2:6. The cation sites, A, are found in the center of each polyhedral cage. This review focuses on the newest discoveries in the group 13-silicon type I clathrate family: A8E8Si38 (A = alkali metal; E = Al, Ga and their properties. Possible approaches to new phases based on earth abundant elements and their potential applications will be discussed.

  17. Attenuation of species abundance distributions by sampling.

    Science.gov (United States)

    Shimadzu, Hideyasu; Darnell, Ross

    2015-04-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  18. The primordial helium abundance from updated emissivities

    CERN Document Server

    Aver, Erik; Porter, R L; Skillman, Evan D

    2013-01-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y_p. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, & Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, & Stasinska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y_p. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increase...

  19. Abundances in the diffuse interstellar medium

    International Nuclear Information System (INIS)

    The wealth of interstellar absorption line data obtained with the Copernicus and IUE satellites has opened up a new era in studies of the interstellar gas. It is now well established that certain elements, generally those with high condensation temperatures, are substantially under-abundant in the gas-phase relative to total solar or cosmic abundances. This depletion of elements is due to the existence of solid material in the form of dust grains in the interstellar medium. Surprisingly, however, recent surveys indicate that even volatile elements such as Zn and S are significantly depleted in many sight lines. Developments in this field which have been made possible by the large base of UV interstellar absorption line data built up over recent years are reviewed and the implications of the results for our understanding of the physical processes governing depletion are discussed. (author)

  20. Microsite Differentiation Drives the Abundance of Soil Ammonia Oxidizing Bacteria along Aridity Gradients.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T; Eldridge, David J; Singh, Brajesh K

    2016-01-01

    Soil ammonia oxidizing bacteria (AOB) and archaea (AOA) are responsible for nitrification in terrestrial ecosystems, and play important roles in ecosystem functioning by modulating the rates of N losses to ground water and the atmosphere. Vascular plants have been shown to modulate the abundance of AOA and AOB in drylands, the largest biome on Earth. Like plants, biotic and abiotic features such as insect nests and biological soil crusts (biocrusts) have unique biogeochemical attributes (e.g., nutrient availability) that may modify the local abundance of AOA and AOB. However, little is known about how these biotic and abiotic features and their interactions modulate the abundance of AOA and AOB in drylands. Here, we evaluate the abundance of amoA genes from AOB and AOA within six microsites commonly found in drylands (open areas, biocrusts, ant nests, grasses, nitrogen-fixing shrubs, and trees) at 21 sites from eastern Australia, including arid and mesic ecosystems that are threatened by predicted increases in aridity. Our results from structural equation modeling suggest that soil microsite differentiation alters the abundance of AOB (but not AOA) in both arid and mesic ecosystems. While the abundance of AOA sharply increased with increasing aridity in all microsites, the response of AOB abundance was microsite-dependent, with increases (nitrogen-fixing shrubs, ant nests), decreases (open areas) or no changes (grasses, biocrusts, trees) in abundance with increasing aridity. Microsites supporting the highest abundance of AOB were trees, nitrogen-fixing shrubs, and ant nests. These results are linked to particular soil characteristics (e.g., total carbon and ammonium) under these microsites. Our findings advance our understanding of key drivers of functionally important microbial communities and N availability in highly heterogeneous ecosystems such as drylands, which may be obscured when different soil microsites are not explicitly considered. PMID:27148194

  1. Microsite Differentiation Drives the Abundance of Soil Ammonia Oxidizing Bacteria along Aridity Gradients

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Maestre, Fernando T.; Eldridge, David J.; Singh, Brajesh K.

    2016-01-01

    Soil ammonia oxidizing bacteria (AOB) and archaea (AOA) are responsible for nitrification in terrestrial ecosystems, and play important roles in ecosystem functioning by modulating the rates of N losses to ground water and the atmosphere. Vascular plants have been shown to modulate the abundance of AOA and AOB in drylands, the largest biome on Earth. Like plants, biotic and abiotic features such as insect nests and biological soil crusts (biocrusts) have unique biogeochemical attributes (e.g., nutrient availability) that may modify the local abundance of AOA and AOB. However, little is known about how these biotic and abiotic features and their interactions modulate the abundance of AOA and AOB in drylands. Here, we evaluate the abundance of amoA genes from AOB and AOA within six microsites commonly found in drylands (open areas, biocrusts, ant nests, grasses, nitrogen-fixing shrubs, and trees) at 21 sites from eastern Australia, including arid and mesic ecosystems that are threatened by predicted increases in aridity. Our results from structural equation modeling suggest that soil microsite differentiation alters the abundance of AOB (but not AOA) in both arid and mesic ecosystems. While the abundance of AOA sharply increased with increasing aridity in all microsites, the response of AOB abundance was microsite-dependent, with increases (nitrogen-fixing shrubs, ant nests), decreases (open areas) or no changes (grasses, biocrusts, trees) in abundance with increasing aridity. Microsites supporting the highest abundance of AOB were trees, nitrogen-fixing shrubs, and ant nests. These results are linked to particular soil characteristics (e.g., total carbon and ammonium) under these microsites. Our findings advance our understanding of key drivers of functionally important microbial communities and N availability in highly heterogeneous ecosystems such as drylands, which may be obscured when different soil microsites are not explicitly considered. PMID:27148194

  2. Exploring masses and CNO surface abundances of red giant stars

    CERN Document Server

    Halabi, Ghina M

    2015-01-01

    A grid of evolutionary sequences of stars in the mass range $1.2$-$7$ M$_{\\odot}$, with solar-like initial composition is presented. We focus on this mass range in order to estimate the masses and calculate the CNO surface abundances of a sample of observed red giants. The stellar models are calculated from the zero-age main sequence till the early asymptotic giant branch (AGB) phase. Stars of M $\\leqslant$ $2.2$M$_{\\odot}$ are evolved through the core helium flash. In this work, an approach is adopted that improves the mass determination of an observed sample of 21 RGB and early AGB stars. This approach is based on comparing the observationally derived effective temperatures and absolute magnitudes with the calculated values based on our evolutionary tracks in the Hertzsprung-Russell diagram. A more reliable determination of the stellar masses is achieved by using evolutionary tracks extended to the range of observation. In addition, the predicted CNO surface abundances are compared to the observationally in...

  3. CO Abundance Variations in the Orion Molecular Cloud

    CERN Document Server

    Ripple, F; Gutermuth, R; Snell, R L; Brunt, C M

    2013-01-01

    Infrared stellar photometry from 2MASS and spectral line imaging observations of 12CO and 13CO J = 1-0 line emission from the FCRAO 14m telescope are analysed to assess the variation of the CO abundance with physical conditions throughout the Orion A and Orion B molecular clouds. Three distinct Av regimes are identified in which the ratio between the 13CO column density and visual extinction changes corresponding to the photon dominated envelope, the strongly self-shielded interior, and the cold, dense volumes of the clouds. Within the strongly self-shielded interior of the Orion A cloud, the 13CO abundance varies by 100% with a peak value located near regions of enhanced star formation activity. The effect of CO depletion onto the ice mantles of dust grains is limited to regions with AV > 10 mag and gas temperatures less than 20 K as predicted by chemical models that consider thermal-evaporation to desorb molecules from grain surfaces. Values of the molecular mass of each cloud are independently derived from...

  4. CHAOS III: Gas-Phase Abundances in NGC5457

    CERN Document Server

    Croxall, Kevin; Berg, Danielle A; Skillman, Evan D; Moustakas, John

    2016-01-01

    The CHemical Abundances of Spirals (CHAOS) project leverages the combined power of the Large Binocular Telescope with the broad spectral range and sensitivity of the Multi Object Double Spectrograph (MODS) to measure direct abundances in large samples of HII regions in spiral galaxies. We present LBT MODS observations of 109 Hii regions in NGC5457, of which 74 have robust measurements of key auroral lines, a factor of 3 larger than all previous published detections of auroral lines in the HII regions of NGC5457. Comparing the temperatures derived from the different ionic species we find: (1) strong correlations of T[NII] with T[SIII] and T[OIII], consistent with little or no intrinsic scatter; (2) a correlation of T[SIII] with T[OIII], but with significant intrinsic dispersion; (3) overall agreement between T[NII], T[SII], and T[OII], as expected, but with significant outliers; (4) the correlations of T[NII] with T[SIII] and T[OIII] match the predictions of photoionization modeling while the correlation of T[...

  5. How accurately can the deuterium abundance be determined?

    CERN Document Server

    Levshakov, S A; Takahara, F

    1997-01-01

    By using a Reverse Monte Carlo technique aimed at the inverse problem in the analysis of the H+D Ly-a absorption from QSO spectra we have estimated the physical parameters of the gas and the large-scale line of sight velocity structure towards Q1009+2956 at z = 2.504 (observations by Burles and Tytler, astro-ph/9603070). We show that for a precise evaluation of the column densities, the detailed velocity field structure is to be determined simultaneously. Our study of the z = 2.504 system yields D/H = (3.75 +/- 0.85)*10^{-5} (2sigma) which gives good agreement between the standard BBN predictions and observational constraints on extra-galactic 4He mass fraction and 7Li abundances in the atmospheres of population II (halo) starts. We conclude that the discordance of D/H with the light element abundances discussed in the literature is a consequence of the assumption of microturbulence (i.e. completely uncorrelated bulk motions) in the analysis of line profiles. The generalized model accounting for a finite corr...

  6. Water Abundance in Molecular Cloud Cores

    CERN Document Server

    Snell, R L; Ashby, M L N; Bergin, E A; Chin, G; Erickson, N R; Goldsmith, P F; Harwit, M; Kleiner, S C; Koch, D G; Neufeld, D A; Patten, B M; Plume, R; Schieder, R; Stauffer, J R; Tolls, V; Wang, Z; Winnewisser, G; Zhang, Y F; Melnick, G J

    2000-01-01

    We present Submillimeter Wave Astronomy Satellite (SWAS) observations of the 1_{10}-1_{01} transition of ortho-water at 557 GHz toward 12 molecular cloud cores. The water emission was detected in NGC 7538, Rho Oph A, NGC 2024, CRL 2591, W3, W3(OH), Mon R2, and W33, and was not detected in TMC-1, L134N, and B335. We also present a small map of the water emission in S140. Observations of the H_2^{18}O line were obtained toward S140 and NGC 7538, but no emission was detected. The abundance of ortho-water relative to H_2 in the giant molecular cloud cores was found to vary between 6x10^{-10} and 1x10^{-8}. Five of the cloud cores in our sample have previous water detections; however, in all cases the emission is thought to arise from hot cores with small angular extents. The water abundance estimated for the hot core gas is at least 100 times larger than in the gas probed by SWAS. The most stringent upper limit on the ortho-water abundance in dark clouds is provided in TMC-1, where the 3-sigma upper limit on the ...

  7. Elemental abundances and classification of CEMP stars

    CERN Document Server

    Allen, Dinah M; Rossi, Silvia; Beers, Tim C; Tsangarides, Stelios A

    2012-01-01

    We present a detailed study of Carbon-Enhanced Metal-Poor (CEMP) stars, based on high-resolution spectroscopic observations of a sample of 18 stars. The stellar spectra for this sample were obtained at the 4.2m William Herschel Telescope (WHT) in 2001 and 2002, using the Utrecht Echelle Spectrograph (UES), at a resolving power R ~52000 and S/N ~ 40, covering the wavelength range lambda-lambda 3700-5700 A. The atmospheric parameters determined for this sample indicate temperatures ranging from 4750 C to 7100 K, log g from 1.5 to 4.3, and metallicities -3.0 <= [Fe/H] <= -1.7. Elemental abundances for C, Na, Mg, Sc, Ti, Cr, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy are determined. Abundances for an additional 109 stars were taken from the literature and combined with the data of our sample. The literature sample reveals a lack of reliable abundance estimates for species that might be associated with the r-process elements for about 67% of CEMP stars, preventing a complete understanding of this clas...

  8. Chemical abundances and kinematics of barium stars

    CERN Document Server

    de Castro, D B; Roig, F; Jilinski, E; Drake, N A; Chavero, C; Silva, J V Sales

    2016-01-01

    In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of $alpha$-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heav...

  9. Abundances In Very Metal Poor Dwarf Stars

    CERN Document Server

    Cohen, J G; McWilliam, A; Shectman, S; Thompson, I; Wasserburg, G J; Ivans, I I; Dehn, M; Karlsson, T; Melendez, J; Cohen, Judith G.; Christlieb, Norbert; William, Andrew Mc; Shectman, Steve; Thompson, Ian; Ivans, Inese; Dehn, Matthias; Karlsson, Torgny

    2004-01-01

    We discuss the detailed composition of 28 extremely metal-poor dwarfs, 22 of which are from the Hamburg/ESO Survey, based on Keck Echelle spectra. Our sample has a median [Fe/H] of -2.7 dex, extends to -3.5 dex, and is somewhat less metal-poor than was expected from [Fe/H](HK,HES) determined from low resolution spectra. Our analysis supports the existence of a sharp decline in the distribution of halo stars with metallicity below [Fe/H] = -3.0 dex. So far no additional turnoff stars with [Fe/H]}<-3.5 have been identified in our follow up efforts. For the best observed elements between Mg and Ni, we find that the abundance ratios appear to have reached a plateau, i.e. [X/Fe] is approximately constant as a function of [Fe/H], except for Cr, Mn and Co, which show trends of abundance ratios varying with [Fe/H]. These abundance ratios at low metallicity correspond approximately to the yield expected from Type II SN with a narrow range in mass and explosion parameters; high mass Type II SN progenitors are requir...

  10. Relative Abundance Measurements in Plumes and Interplumes

    CERN Document Server

    Guennou, Chloé; Savin, Daniel Wolf

    2015-01-01

    We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) 10 eV). We have used EIS spectroscopic observations made on 2007 March 13 and 14 over an ~24 hour period to characterize abundance variations in plumes and interplumes. To assess their elemental composition, we have used a differential emission measure (DEM) analysis, which accounts for the thermal structure of the observed plasma. We have used lines from ions of iron, silicon, and sulfur. From these we have estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These res...

  11. Aerial survey estimates of fallow deer abundance

    Science.gov (United States)

    Gogan, Peter J.; Gates, Natalie B.; Lubow, Bruce C.; Pettit, Suzanne

    2012-01-01

    Reliable estimates of the distribution and abundance of an ungulate species is essential prior to establishing and implementing a management program. We used ground surveys to determine distribution and ground and aerial surveys and individually marked deer to estimate the abundance of fallow deer (Dama dama) in north-coastal California. Fallow deer had limited distribution and heterogeneous densities. Estimated post-rut densities across 4 annual surveys ranged from a low of 1.4 (SE=0.2) deer/km2 to a high of 3.3 (se=0.5) deer/km2 in a low density stratum and from 49.0 (SE=8.3) deer/km2 to 111.6 deer/km2 in a high density stratum. Sightability was positively influenced by the presence of white color-phase deer in a group and group size, and varied between airial and ground-based observers and by density strata. Our findings underscore the utility of double-observer surveys and aerial surveys with individually marked deer, both incorporating covariates to model sightability, to estimate deer abundance.

  12. CH abundance gradient in TMC-1

    CERN Document Server

    Suutarinen, Aleksi; Harju, Jorma; Heikkilä, Arto; Hotzel, Stephan; Juvela, Mika; Millar, Tom J; Walsh, Catherina; Wouterloot, Jan Gerard Amos

    2011-01-01

    We observed the 9-cm Lambda-doubling lines of CH along the dense filament of TMC-1. The CH column densities were compared with the total H2 column densities derived using the 2MASS NIR data and previously published SCUBA maps and with OH column densities derived using previous observations with Effelsberg. We also modelled the chemical evolution of TMC-1 adopting physical conditions typical of dark clouds using the UMIST Database for Astrochemistry gas-phase reaction network to aid the interpretation of the observed OH/CH abundance ratios. The CH column density has a clear peak in the vicinity of the cyanopolyyne maximum of TMC-1. The fractional CH abundance relative to H2 increases steadily from the northwestern end of the filament where it lies around 1.0e-8, to the southeast where it reaches a value of 2.0e-8. The OH and CH column densities are well correlated, and we obtained OH/CH abundance ratios of ~ 16 - 20. These values are clearly larger than what has been measured recently in diffuse interstellar g...

  13. Hans A. Bethe Prize Lecture: The Primordial Helium Abundance

    Science.gov (United States)

    Peimbert, Manuel

    2012-03-01

    It is generally accepted that the production of the light elements (He, D, and Li) during the early stages of the expansion of the Universe is one of the three pillars of the Big Bang theory. The main results obtained from the observational determination of the primordial helium abundance, Yp, and its comparison with the value predicted by Big Bang Nucleosynthesis will be presented, in particular: a) the recognition that galaxies form with Yp in the 0.24 to 0.26 range, b) that Yp was produced during the Big Bang, c) that Yp is fundamental as a critical test for cosmological theories and the baryonic content of the Universe, and d) that the value of Yp provides an observational constraint on the number of light neutrino species, which is smaller than four and probably equal to three. In addition, the present status of the observationally determined Yp value based on extragalactic H II regions will be discussed.

  14. Asymptotic size determines species abundance in the marine size spectrum

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Beyer, Jan

    2006-01-01

    The majority of higher organisms in the marine environment display indeterminate growth; that is, they continue to grow throughout their life, limited by an asymptotic size. We derive the abundance of species as a function of their asymptotic size. The derivation is based on size-spectrum theory......, where population structure is derived from physiology and simple arguments regarding the predator-prey interaction. Using a hypothesis of constant satiation, which states that the average degree of satiation is independent of the size of an organism, the number of individuals with a given size is found...... to be proportional to the weight raised to the power -2.05, independent of the predator/prey size ratio. This is the first time the spectrum exponent has been derived solely on the basis of processes at the individual level. The theory furthermore predicts that the parameters in the von Bertalanffy growth function...

  15. Galactic abundance gradients from Cepheids : On the iron abundance gradient around 10-12 kpc

    OpenAIRE

    Lemasle, B.; Francois, P.; Piersimoni, A.; Pedicelli, S.; Bono, G.; Laney, C. D.; Primas, F.; Romaniello, M.

    2008-01-01

    Context: Classical Cepheids can be adopted to trace the chemical evolution of the Galactic disk since their distances can be estimated with very high accuracy. Aims: Homogeneous iron abundance measurements for 33 Galactic Cepheids located in the outer disk together with accurate distance determinations based on near-infrared photometry are adopted to constrain the Galactic iron gradient beyond 10 kpc. Methods: Iron abundances were determined using high resolution Cepheid spectra collected wit...

  16. The influence of weather and lemmings on spatiotemporal variation in the abundance of multiple avian guilds in the arctic.

    Directory of Open Access Journals (Sweden)

    Barry G Robinson

    Full Text Available Climate change is occurring more rapidly in the Arctic than other places in the world, which is likely to alter the distribution and abundance of migratory birds breeding there. A warming climate can provide benefits to birds by decreasing spring snow cover, but increases in the frequency of summer rainstorms, another product of climate change, may reduce foraging opportunities for insectivorous birds. Cyclic lemming populations in the Arctic also influence bird abundance because Arctic foxes begin consuming bird eggs when lemmings decline. The complex interaction between summer temperature, precipitation, and the lemming cycle hinder our ability to predict how Arctic-breeding birds will respond to climate change. The main objective of this study was to investigate the relationship between annual variation in weather, spring snow cover, lemming abundance and spatiotemporal variation in the abundance of multiple avian guilds in a tundra ecosystem in central Nunavut, Canada: songbirds, shorebirds, gulls, loons, and geese. We spatially stratified our study area based on vegetation productivity, terrain ruggedness, and freshwater abundance, and conducted distance sampling to estimate strata-specific densities of each guild during the summers of 2010-2012. We also monitored temperature, rainfall, spring snow cover, and lemming abundance each year. Spatial variation in bird abundance matched what was expected based on previous ecological knowledge, but weather and lemming abundance also significantly influenced the abundance of some guilds. In particular, songbirds were less abundant during the cool, wet summer with moderate snow cover, and shorebirds and gulls declined with lemming abundance. The abundance of geese did not vary over time, possibly because benefits created by moderate spring snow cover were offset by increased fox predation when lemmings were scarce. Our study provides an example of a simple way to monitor the correlation between

  17. Abundant Solar Nebula Solids in Comets

    Science.gov (United States)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Clemett, S.

    2016-01-01

    Comets have been proposed to consist of unprocessed interstellar materials together with a variable amount of thermally annealed interstellar grains. Recent studies of cometary solids in the laboratory have shown that comets instead consist of a wide range of materials from across the protoplanetary disk, in addition to a minor complement of interstellar materials. These advances were made possible by the return of direct samples of comet 81P/Wild 2 coma dust by the NASA Stardust mission and recent advances in microscale analytical techniques. Isotopic studies of 'cometary' chondritic porous interplanetary dust particles (CP-IDPs) and comet 81P/Wild 2 Stardust samples show that preserved interstellar materials are more abundant in comets than in any class of meteorite. Identified interstellar materials include sub-micron-sized presolar silicates, oxides, and SiC dust grains and some fraction of the organic material that binds the samples together. Presolar grain abundances reach 1 weight percentage in the most stardust-rich CP-IDPs, 50 times greater than in meteorites. Yet, order of magnitude variations in presolar grain abundances among CP-IDPs suggest cometary solids experienced significant variations in the degree of processing in the solar nebula. Comets contain a surprisingly high abundance of nebular solids formed or altered at high temperatures. Comet 81P/Wild 2 samples include 10-40 micron-sized, refractory Ca- Al-rich inclusion (CAI)-, chondrule-, and ameboid olivine aggregate (AOA)-like materials. The O isotopic compositions of these refractory materials are remarkably similar to their meteoritic counterparts, ranging from 5 percent enrichments in (sup 16) O to near-terrestrial values. Comet 81P/Wild 2 and CP-IDPs also contain abundant Mg-Fe crystalline and amorphous silicates whose O isotopic compositions are also consistent with Solar System origins. Unlike meteorites, that are dominated by locally-produced materials, comets appear to be composed of

  18. Exploring masses and CNO surface abundances of red giant stars

    Science.gov (United States)

    Halabi, Ghina M.; Eid, Mounib El

    2015-08-01

    A grid of evolutionary sequences of stars in the mass range 1.2-7M⊙, with solar-like initial composition is presented. We focus on this mass range in order to estimate the masses and calculate the CNO surface abundances of a sample of observed red giants. The stellar models are calculated from the zero-age main sequence till the early asymptotic giant branch (AGB) phase. Stars of M ≤ 2.2M⊙ are evolved through the core helium flash. In this work, an approach is adopted that improves the mass determination of an observed sample of 21 RGB and early AGB stars. This approach is based on comparing the observationally derived effective temperatures and absolute magnitudes with the calculated values based on our evolutionary tracks in the Hertzsprung-Russell diagram. A more reliable determination of the stellar masses is achieved by using evolutionary tracks extended to the range of observation. In addition, the predicted CNO surface abundances are compared to the observationally inferred values in order to show how far standard evolutionary calculation can be used to interpret available observations and to illustrate the role of convective mixing. We find that extra mixing beyond the convective boundary determined by the Schwarzschild criterion is needed to explain the observational oxygen isotopic ratios in low-mass stars. The effect of recent determinations of proton capture reactions and their uncertainties on the 16O/17O and 14N/15N ratios is also shown. It is found that the 14N( p, γ)15O reaction is important for predicting the 14N/15N ratio in red giants.

  19. Community structure influences species' abundance along environmental gradients.

    Science.gov (United States)

    Eloranta, Antti P; Helland, Ingeborg P; Sandlund, Odd T; Hesthagen, Trygve; Ugedal, Ola; Finstad, Anders G

    2016-01-01

    Species' response to abiotic environmental variation can be influenced by local community structure and interspecific interactions, particularly in restricted habitats such as islands and lakes. In temperate lakes, future increase in water temperature and run-off of terrestrial (allochthonous) dissolved organic carbon (DOC) are predicted to alter community composition and the overall ecosystem productivity. However, little is known about how the present community structure and abiotic environmental variation interact to affect the abundance of native fish populations. We used a space-for-time approach to study how local community structure interact with lake morphometric and climatic characteristics (i.e. temperature and catchment productivity) to affect brown trout (Salmo trutta L.) yield in 283 Norwegian lakes located in different biogeographical regions. Brown trout yield (based on data from standardized survey gill net fishing; g 100 m(-2) gill net night(-1)) was generally lower in lakes where other fish species were present than in lakes with brown trout only. The yield showed an overall negative relationship with increasing temperature and a positive relationship with lake shoreline complexity. Brown trout yield was also negatively correlated with DOC load (measured using Normalized Difference Vegetation Index as a proxy) and lake size and depth (measured using terrain slope as a proxy), but only in lakes where other fish species were present. The observed negative response of brown trout yield to increasing DOC load and proportion of the pelagic open-water area is likely due to restricted (littoral) niche availability and competitive dominance of more pelagic fishes such as Arctic charr (Salvelinus alpinus (L.)). Our study highlights that, through competitive interactions, the local community structure can influence the response of a species' abundance to variation in abiotic conditions. Changes in biomass and niche use of top predators (such as the brown

  20. Cascading top-down effects of changing oceanic predator abundances.

    Science.gov (United States)

    Baum, Julia K; Worm, Boris

    2009-07-01

    1. Top-down control can be an important determinant of ecosystem structure and function, but in oceanic ecosystems, where cascading effects of predator depletions, recoveries, and invasions could be significant, such effects had rarely been demonstrated until recently. 2. Here we synthesize the evidence for oceanic top-down control that has emerged over the last decade, focusing on large, high trophic-level predators inhabiting continental shelves, seas, and the open ocean. 3. In these ecosystems, where controlled manipulations are largely infeasible, 'pseudo-experimental' analyses of predator-prey interactions that treat independent predator populations as 'replicates', and temporal or spatial contrasts in predator populations and climate as 'treatments', are increasingly employed to help disentangle predator effects from environmental variation and noise. 4. Substantial reductions in marine mammals, sharks, and piscivorous fishes have led to mesopredator and invertebrate predator increases. Conversely, abundant oceanic predators have suppressed prey abundances. Predation has also inhibited recovery of depleted species, sometimes through predator-prey role reversals. Trophic cascades have been initiated by oceanic predators linking to neritic food webs, but seem inconsistent in the pelagic realm with effects often attenuating at plankton. 5. Top-down control is not uniformly strong in the ocean, and appears contingent on the intensity and nature of perturbations to predator abundances. Predator diversity may dampen cascading effects except where nonselective fisheries deplete entire predator functional groups. In other cases, simultaneous exploitation of predator and prey can inhibit prey responses. Explicit consideration of anthropogenic modifications to oceanic foodwebs should help inform predictions about trophic control. 6. Synthesis and applications. Oceanic top-down control can have important socio-economic, conservation, and management implications as

  1. Coronal Abundance Anomalies in Solar-Like Stars

    Science.gov (United States)

    Laming, John

    We propose to model the trend of coronal abundance anomalies observed in a sample of solar-like stars by Wood & Linsky (2010). Dwarf stars of similar spectral type to the Sun show what has become known as a FIP (First Ionization Potential) Effect, where elements with first ionization potential below about 10 eV are enhanced in abundance in the corona by a factor of about 3 - 4. Stars of later spectral type show a diminished FIP effect, with the anomaly disappearing at about K5 spectral type. Beyond this, M dwarf stars show an inverse FIP effect, with the low FIP ions becoming depleted in the stellar corona, by factors of order 2.5 - 3. The solar case of positive FIP effect has been successfully interpreted as being due to the action of the ponderomotive force associated with chromospheric Alfven waves. In conditions in which upgoing Alfven waves are transmitted into coronal loops, or in which coronally generated waves reflect at loop footpoints, the ponderomotive force is directed upwards, and accelerates chromospheric ions (the low FIP elements) into the corona. Neutral atoms are not affected. The inverse FIP effect can arise when upward propagating chromospheric Alfven waves are reflected back down again at coronal loop footpoints, due to a mismatch between the wave frequency and the loop resonance. We propose to study stars for which parameters like asteroseismic oscillation frequencies, coronal abundance anomalies, and chromospheric structure are known. As well as constraining coronal magnetic fields and loop resonances in these stars, we expect important insights into the nature of stellar dynamos since the M dwarfs in the sample (with inverse FIP effect) are at or near the fully convective limit. Finally, we will be able to assess potential fractionation in the O/Ne abundance ratio. Drake & Testa (2005) argued that Ne is depleted in the solar corona relative to O, but not in the coronae of more active stars. Our FIP models provide some support for this in the

  2. A New Look at Carbon Abundances in Planetary Nebulae; 4, Implications for Stellar Nucleosynthesis

    CERN Document Server

    Henry, R B C; Bates, J A

    1999-01-01

    This paper is the fourth and final report on a project designed to study carbon abundances in a sample of planetary nebulae representing a broad range in progenitor mass and metallicity. We present newly acquired optical spectrophotometric data for three Galactic planetary nebulae IC 418, NGC 2392, and NGC 3242 and combine them with UV data from the IUE Final Archive for identical positions in each nebula to determine accurate abundances of He, C, N, O, and Ne at one or more locations in each object. We then collect abundances of these elements for the entire sample and compare them with theoretical predictions of planetary nebula abundances from a grid of intermediate mass star models. We find some consistency between observations and theory, lending modest support to our current understanding of nucleosynthesis in stars below 8 M_o in birth mass. Overall, we believe that observed abundances agree with theoretical predictions to well within an order of magnitude but probably not better than within a factor o...

  3. Efficient estimation of abundance for patchily distributed populations via two-phase, adaptive sampling.

    Science.gov (United States)

    Conroy, M.J.; Runge, J.P.; Barker, R.J.; Schofield, M.R.; Fonnesbeck, C.J.

    2008-01-01

    Many organisms are patchily distributed, with some patches occupied at high density, others at lower densities, and others not occupied. Estimation of overall abundance can be difficult and is inefficient via intensive approaches such as capture-mark-recapture (CMR) or distance sampling. We propose a two-phase sampling scheme and model in a Bayesian framework to estimate abundance for patchily distributed populations. In the first phase, occupancy is estimated by binomial detection samples taken on all selected sites, where selection may be of all sites available, or a random sample of sites. Detection can be by visual surveys, detection of sign, physical captures, or other approach. At the second phase, if a detection threshold is achieved, CMR or other intensive sampling is conducted via standard procedures (grids or webs) to estimate abundance. Detection and CMR data are then used in a joint likelihood to model probability of detection in the occupancy sample via an abundance-detection model. CMR modeling is used to estimate abundance for the abundance-detection relationship, which in turn is used to predict abundance at the remaining sites, where only detection data are collected. We present a full Bayesian modeling treatment of this problem, in which posterior inference on abundance and other parameters (detection, capture probability) is obtained under a variety of assumptions about spatial and individual sources of heterogeneity. We apply the approach to abundance estimation for two species of voles (Microtus spp.) in Montana, USA. We also use a simulation study to evaluate the frequentist properties of our procedure given known patterns in abundance and detection among sites as well as design criteria. For most population characteristics and designs considered, bias and mean-square error (MSE) were low, and coverage of true parameter values by Bayesian credibility intervals was near nominal. Our two-phase, adaptive approach allows efficient estimation of

  4. Multi-scale models of grassland passerine abundance in a fragmented system in Wisconsin

    Science.gov (United States)

    Renfrew, R.B.; Ribic, C.A.

    2008-01-01

    Fragmentation of grasslands has been implicated in grassland bird population declines. Multi-scale models are being increasingly used to assess potential factors that influence grassland bird presence, abundance, and productivity. However, studies rarely assess fragmentation metrics, and seldom evaluate more than two scales or interactions among scales. We evaluated the relative importance of characteristics at multiple scales to patterns in relative abundance of Savannah Sparrow (Passerculus sandwichensis), Grasshopper Sparrow (Ammodramus savannarum), Eastern Meadowlark (Sturnella magna), and Bobolink (Dolichonyx oryzivorus). We surveyed birds in 74 southwestern Wisconsin pastures from 1997 to 1999 and compared models with explanatory variables from multiple scales: within-patch vegetation structure (microhabitat), patch (macrohabitat), and three landscape extents. We also examined interactions between macrohabitat and landscape factors. Core area of pastures was an important predictor of relative abundance, and composition of the landscape was more important than configuration. Relative abundance was frequently higher in pastures with more core area and in landscapes with more grassland and less wooded area. The direction and strength of the effect of core pasture size on relative abundance changed depending on amount of wooded area in the landscape. Relative abundance of grassland birds was associated with landscape variables more frequently at the 1200-m scale than at smaller scales. To develop better predictive models, parameters at multiple scales and their interactive effects should be included, and results should be evaluated in the context of microhabitat variability, landscape composition, and fragmentation in the study area. ?? 2007 Springer Science+Business Media B.V.

  5. Modeling unobserved sources of heterogeneity in animal abundance using a Dirichlet process prior

    Science.gov (United States)

    Dorazio, R.M.; Mukherjee, B.; Zhang, L.; Ghosh, M.; Jelks, H.L.; Jordan, F.

    2008-01-01

    In surveys of natural populations of animals, a sampling protocol is often spatially replicated to collect a representative sample of the population. In these surveys, differences in abundance of animals among sample locations may induce spatial heterogeneity in the counts associated with a particular sampling protocol. For some species, the sources of heterogeneity in abundance may be unknown or unmeasurable, leading one to specify the variation in abundance among sample locations stochastically. However, choosing a parametric model for the distribution of unmeasured heterogeneity is potentially subject to error and can have profound effects on predictions of abundance at unsampled locations. In this article, we develop an alternative approach wherein a Dirichlet process prior is assumed for the distribution of latent abundances. This approach allows for uncertainty in model specification and for natural clustering in the distribution of abundances in a data-adaptive way. We apply this approach in an analysis of counts based on removal samples of an endangered fish species, the Okaloosa darter. Results of our data analysis and simulation studies suggest that our implementation of the Dirichlet process prior has several attractive features not shared by conventional, fully parametric alternatives. ?? 2008, The International Biometric Society.

  6. Can occupancy-abundance models be used to monitor wolf abundance?

    Directory of Open Access Journals (Sweden)

    M Cecilia Latham

    Full Text Available Estimating the abundance of wild carnivores is of foremost importance for conservation and management. However, given their elusive habits, direct observations of these animals are difficult to obtain, so abundance is more commonly estimated from sign surveys or radio-marked individuals. These methods can be costly and difficult, particularly in large areas with heavy forest cover. As an alternative, recent research has suggested that wolf abundance can be estimated from occupancy-abundance curves derived from "virtual" surveys of simulated wolf track networks. Although potentially more cost-effective, the utility of this approach hinges on its robustness to violations of its assumptions. We assessed the sensitivity of the occupancy-abundance approach to four assumptions: variation in wolf movement rates, changes in pack cohesion, presence of lone wolves, and size of survey units. Our simulations showed that occupancy rates and wolf pack abundances were biased high if track surveys were conducted when wolves made long compared to short movements, wolf packs were moving as multiple hunting units as opposed to a cohesive pack, and lone wolves were moving throughout the surveyed landscape. We also found that larger survey units (400 and 576 km2 were more robust to changes in these factors than smaller survey units (36 and 144 km2. However, occupancy rates derived from large survey units rapidly reached an asymptote at 100% occupancy, suggesting that these large units are inappropriate for areas with moderate to high wolf densities (>15 wolves/1,000 km2. Virtually-derived occupancy-abundance relationships can be a useful method for monitoring wolves and other elusive wildlife if applied within certain constraints, in particular biological knowledge of the surveyed species needs to be incorporated into the design of the occupancy surveys. Further, we suggest that the applicability of this method could be extended by directly incorporating some of its

  7. Relating large-scale climate variability to local species abundance: ENSO forcing and shrimp in Breton Sound, Louisiana, USA

    Science.gov (United States)

    Piazza, Bryan P.; LaPeyre, Megan K.; Keim, B.D.

    2010-01-01

    Climate creates environmental constraints (filters) that affect the abundance and distribution of species. In estuaries, these constraints often result from variability in water flow properties and environmental conditions (i.e. water flow, salinity, water temperature) and can have significant effects on the abundance and distribution of commercially important nekton species. We investigated links between large-scale climate variability and juvenile brown shrimp Farfantepenaeus aztecus abundance in Breton Sound estuary, Louisiana (USA). Our goals were to (1) determine if a teleconnection exists between local juvenile brown shrimp abundance and the El Niño Southern Oscillation (ENSO) and (2) relate that linkage to environmental constraints that may affect juvenile brown shrimp recruitment to, and survival in, the estuary. Our results identified a teleconnection between winter ENSO conditions and juvenile brown shrimp abundance in Breton Sound estuary the following spring. The physical connection results from the impact of ENSO on winter weather conditions in Breton Sound (air pressure, temperature, and precipitation). Juvenile brown shrimp abundance effects lagged ENSO by 3 mo: lower than average abundances of juvenile brown shrimp were caught in springs following winter El Niño events, and higher than average abundances of brown shrimp were caught in springs following La Niña winters. Salinity was the dominant ENSO-forced environmental filter for juvenile brown shrimp. Spring salinity was cumulatively forced by winter river discharge, winter wind forcing, and spring precipitation. Thus, predicting brown shrimp abundance requires incorporating climate variability into models.

  8. Understanding relationships among abundance, extirpation,and climate at ecoregional scales

    Science.gov (United States)

    Beever, Erik A.; Solomon Dubrowski,; ,; ,; J. Long,; ,; A. Mysnberge,; Piekielek, N. B.

    2014-01-01

    Recent research on mountain-dwelling species has illustrated changes in species’ distributional patterns in response to climate change. Abundance of a species will likely provide an earlier warning indicator of change than will occupancy, yet relationships between abundance and climatic factors have received less attention. We tested whether predictors of counts of American pikas (Ochotona princeps) during surveys from the Great Basin region in 1994–1999 and 2003–2008 differed between the two periods. Additionally, we tested whether various modeled aspects of ecohydrology better predicted relative density than did average annual precipitation, and whether risk of site-wide extirpation predicted subsequent population counts of pikas. We observed several patterns of change in pika abundance at range edges that likely constitute early warnings of distributional shifts. Predictors of pika abundance differed strongly between the survey periods, as did pika extirpation patterns previously reported from this region. Additionally, maximum snowpack and growing-season precipitation resulted in better-supported models than those using average annual precipitation, and constituted two of the top three predictors of pika density in the 2000s surveys (affecting pikas perhaps via vegetation). Unexpectedly, we found that extirpation risk positively predicted subsequent population size. Our results emphasize the need to clarify mechanisms underlying biotic responses to recent climate change at organism-relevant scales, to inform management and conservation strategies for species of concern.

  9. Abundance anomalies in tidal disruption events

    Science.gov (United States)

    Kochanek, C. S.

    2016-05-01

    The ˜10 per cent of tidal disruption events (TDEs) due to stars more massive than M* ≳ M⊙ should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ˜25 per cent on average because it becomes inaccessible once it is sequestered in the high-density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main-sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle - stars with M* ≳ M⊙ quickly show an increase in their average N/C ratio by factors of 3-10. Because low-mass stars evolve slowly and high-mass stars are rare, TDEs showing high N/C will almost all be due to ˜1-2 M⊙ stars disrupted on the main sequence. Like helium, portions of the debris will show still larger changes in C and N, and the anomalies decline as the star leaves the main sequence. The enhanced [N/C] abundance ratio of these TDEs provides the first natural explanation for the rare, nitrogen-rich quasars and may also explain the strong nitrogen emission seen in ultraviolet spectra of ASASSN-14li.

  10. Abundance and diversity of marine microbial eukaryotes

    OpenAIRE

    Pernice, Massimo Ciro

    2014-01-01

    [EN]Microeukaryotes are important ecological players in any kind of ecosystem, most notably in the ocean, and it is therefore essential to collect information about their abundance and diversity. To achieve this general goal this thesis was structured in two parts. The first part represents an effort to define our “diversity unit” from studies based on the well-known cloning and Sanger sequencing approach. Basically, we wanted to establish a solid baseline for the second part of the thesis. W...

  11. Abundance Anomalies In Tidal Disruption Events

    OpenAIRE

    Kochanek, C. S.

    2015-01-01

    The ~10% of tidal disruption events (TDEs) due to stars more massive than the Sun should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ~25% on average because it becomes inaccessible once it is sequestered in the high density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main sequence star can be enhanced in helium by factors of ...

  12. North Sea Elasmobranchs: distribution, abundance and biodiversity

    OpenAIRE

    Daan, N.; Heessen, H.J.L.; Hofstede, ter, AHM Arthur

    2005-01-01

    Based on data from various international and national surveys, an overview is given of the fine-scale distribution (resolution of 20¿longitude * 10¿ latitude; ¿ 10*10 nm) and trends in abundance of elasmobranch species reported from the North Sea. Presence-absence maps are produced based on 4 surveys, which help to delineate distribution limits of the less common species, while maps in terms of catch rates (International Bottom Trawl Survey data only) are given for the seven most common shark...

  13. Estimating the relationship between abundance and distribution

    DEFF Research Database (Denmark)

    Rindorf, Anna; Lewy, Peter

    2012-01-01

    provide unbiased estimates of the relationship when estimated from count data. The indices investigated include the proportion of empty samples, the proportion of structurally empty samples, Lloyds index of patchiness, measures derived from Lorenz curves (such as D95 and the Gini index), and measures...... based on Euclidean distance to the centre of gravity of the spatial distribution. Only the proportion of structurally empty areas, Lloyds index, and indices of the distance to the centre of gravity of the spatial distribution are unbiased at all levels of abundance. The remaining indices generate...

  14. Detecting significant changes in protein abundance

    Directory of Open Access Journals (Sweden)

    Kai Kammers

    2015-06-01

    Full Text Available We review and demonstrate how an empirical Bayes method, shrinking a protein's sample variance towards a pooled estimate, leads to far more powerful and stable inference to detect significant changes in protein abundance compared to ordinary t-tests. Using examples from isobaric mass labelled proteomic experiments we show how to analyze data from multiple experiments simultaneously, and discuss the effects of missing data on the inference. We also present easy to use open source software for normalization of mass spectrometry data and inference based on moderated test statistics.

  15. Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona

    Science.gov (United States)

    Landi, E.; Testa, P.

    2015-02-01

    In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017 this value is lower than the transition region determinations from the quiet Sun used to infer the neon photospheric abundance from the oxygen photospheric abundance. Also, the Ne/O ratio we determined from SUMER is in excellent agreement with in situ determinations from ACE/SWICS. In 2005-2008, the Ne/O abundance ratio increased with time and reached 0.25 ± 0.05, following the same trend found in the slowest wind analyzed by ACE/SWICS. Further, we measure the absolute abundance in the corona for both oxygen and neon from the data set of 1996 November 22, obtaining A o = 8.99 ± 0.04 and A Ne = 7.92 ± 0.03, and we find that both elements are affected by the first ionization potential (FIP) effect, with oxygen being enhanced by a factor of 1.4-2.1 over its photospheric abundance, and neon being changed by a factor of 0.75-1.20. We conclude that the Ne/O ratio is not constant in the solar atmosphere, both in time and at different heights, and that it cannot be reliably used to infer the neon abundance in the photosphere. Also, we argue that the FIP effect was less effective during the minimum of solar cycle 24, and that the Ne/O = 0.25 ± 0.05 value measured at that time is closer to the true photospheric value, leading to a neon photospheric abundance larger than assumed by ≈40%. We discuss the implications of these results for the solar abundance problem, for the FIP effect, and for the identification of the source regions of the solar wind.

  16. H{sub 2}O ABUNDANCES IN THE ATMOSPHERES OF THREE HOT JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Madhusudhan, Nikku; Hedges, Christina [Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA (United Kingdom); Crouzet, Nicolas; McCullough, Peter R. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Deming, Drake, E-mail: nmadhu@ast.cam.ac.uk [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)

    2014-08-10

    The core accretion theory for giant planet formation predicts enrichment of elemental abundances in planetary envelopes caused by runaway accretion of planetesimals, which is consistent with measured super-solar abundances of C, N, P, S, Xe, and Ar in Jupiter's atmosphere. However, the abundance of O, which is expected to be the most dominant constituent of planetesimals, is unknown for solar system giant planets, owing to the condensation of water in their ultra-cold atmospheres, thereby posing a key unknown in solar system formation. On the other hand, hundreds of extrasolar ''hot Jupiters'' are known with very high temperatures (≥1000 K), making them excellent targets to measure H{sub 2}O abundances and, hence, oxygen in their atmospheres. We constrain the atmospheric H{sub 2}O abundances in three hot Jupiters (HD 189733b, HD 209458b, and WASP-12b), spanning a wide temperature range (1200-2500 K), using their near-infrared transmission spectra obtained using the Wide Field Camera 3 instrument on board the Hubble Space Telescope. We report conclusive measurements of H{sub 2}O in HD 189733b and HD 209458b, while that in WASP-12b is not well constrained by present data. The data allow nearly solar as well as significantly sub-solar abundances in HD 189733b and WASP-12b. However, for HD 209458b, we report the most precise H{sub 2}O measurement in an exoplanet to date that suggests a ∼20-135 × sub-solar H{sub 2}O abundance. We discuss the implications of our results on the formation conditions of hot Jupiters and on the likelihood of clouds in their atmospheres. Our results highlight the critical importance of high-precision spectra of hot Jupiters for deriving their H{sub 2}O abundances.

  17. Sooty Shearwater - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  18. Northern Fulmar - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  19. Wilson's Storm Petrel - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  20. Herring Gull - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...