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Sample records for potential reservoir hosts

  1. Internal structure of fault zones in geothermal reservoirs: Examples from palaeogeothermal fields and potential host rocks

    NASA Astrophysics Data System (ADS)

    Leonie Philipp, Sonja; Reyer, Dorothea; Meier, Silke; Bauer, Johanna F.; Afşar, Filiz

    2014-05-01

    Fault zones commonly have great effects on fluid transport in geothermal reservoirs. During fault slip all the pores and small fractures that meet with the slip plane become interconnected so that the inner part of the fault, the fault core, consisting of breccia or gouge, may suddenly develop a very high permeability. This is evidenced, for example by networks of mineral veins in deeply eroded fault zones in palaeogeothermal fields. Inactive faults, however, may have low permeabilities and even act as flow barriers. In natural and man-made geothermal reservoirs, the orientation of fault zones in relation to the current stress field and their internal structure needs be known as accurately as possible. One reason is that the activity of the fault zone depends on its angle to the principal stress directions. Another reason is that the outer part of a fault zone, the damage zone, comprises numerous fractures of various sizes. Here we present field examples of faults, and associated joints and mineral veins, in palaeogeothermal fields, and potential host rocks for man-made geothermal reservoirs, respectively. We studied several localities of different stratigraphies, lithologies and tectonic settings: (1) 58 fault zones in 22 outcrops from Upper Carboniferous to Upper Cretaceous in the Northwest German Basin (siliciclastic, carbonate and volcanic rocks); (2) 16 fault zones in 9 outcrops in Lower Permian to Middle Triassic (mainly sandstone, limestone and granite) in the Upper Rhine Graben; and (3) 74 fault zones in two coastal sections of Upper Triassic and Lower Jurassic age (mudstones and limestone-marl alternations) in the Bristol Channel Basin, UK. (1) and (2) are outcrop analogues of geothermal reservoir horizons, (3) represent palaeogeothermal fields with mineral veins. The field studies in the Northwest German Basin (1) show pronounced differences between normal-fault zones in carbonate and clastic rocks. In carbonate rocks clear damage zones occur that are

  2. Mycobacterium bovis: characteristics of wildlife reservoir hosts.

    PubMed

    Palmer, M V

    2013-11-01

    Mycobacterium bovis is the cause of tuberculosis in animals and sometimes humans. Many developed nations have long-standing programmes to eradicate tuberculosis in livestock, principally cattle. As disease prevalence in cattle decreases these efforts are sometimes impeded by passage of M. bovis from wildlife to cattle. In epidemiological terms, disease can persist in some wildlife species, creating disease reservoirs, if the basic reproduction rate (R0) and critical community size (CCS) thresholds are achieved. Recognized wildlife reservoir hosts of M. bovis include the brushtail possum (Trichosurus vulpecula) in New Zealand, European badger (Meles meles) in Great Britain and Ireland, African buffalo (Syncerus caffer) in South Africa, wild boar (Sus scrofa) in the Iberian Peninsula and white-tailed deer (Odocoileus virginianus) in Michigan, USA. The epidemiological concepts of R0 and CCS are related to more tangible disease/pathogen characteristics such as prevalence, pathogen-induced pathology, host behaviour and ecology. An understanding of both epidemiological and disease/pathogen characteristics is necessary to identify wildlife reservoirs of M. bovis. In some cases, there is a single wildlife reservoir host involved in transmission of M. bovis to cattle. Complexity increases, however, in multihost systems where multiple potential reservoir hosts exist. Bovine tuberculosis eradication efforts require elimination of M. bovis transmission between wildlife reservoirs and cattle. For successful eradication identification of true wildlife reservoirs is critical, as disease control efforts are most effective when directed towards true reservoirs. PMID:24171844

  3. Red fox (Vulpes vulpes) as a potential reservoir host of cardiorespiratory parasites in Bosnia and Herzegovina.

    PubMed

    Hodžić, Adnan; Alić, Amer; Klebić, Ismar; Kadrić, Mirsad; Brianti, Emanuele; Duscher, Georg Gerhard

    2016-06-15

    Red fox (Vulpes vulpes) is considered as reservoir of different cardiorespiratory parasites of veterinary and medical importance. Since data on cardiorespiratory parasites in foxes in Bosnia and Herzegovina are still lacking, the aims of the present study were to (i) investigate the prevalence and geographical distribution of these parasites, (ii) determine genetic diversity of detected parasite species, and (iii) to estimate the role of foxes in the transmission cycle to companion animals and humans. Four species, morphologically and molecularly identified as Eucoleus boehmi (64.6%; 51/79), Eucoleus aerophilus (69.7%; 154/221), Crenosoma vulpis (45.7%; 101/221) and Linguatula serrata (1.3%; 1/79) were retrieved from nasal cavity and lungs in 184 (83.3%) animals. The occurrence of heartworms, Angiostrongylus vasorum and Dirofilaria immitis was not detected by necropsy or PCR. Furthermore, three distinct haplotypes of E. aerophilus (I, III, XV) and two of C. vulpis (I, II) previously reported in pet animals and wild carnivores were confirmed in this study. A new haplotype of C. vulpis (designated as haplotype V) was also identified based on 12S rRNA gene for the first time. The present study indicates a high prevalence and wide distribution of nasal and lung nematodes in fox population in Bosnia and Herzegovina, and supports the existence of transmission patterns between wildlife and pet animals. PMID:27198779

  4. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus

    PubMed Central

    Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

    2015-01-01

    Abstract Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species. PMID:26517724

  5. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus) as a Potential Reservoir Host Species for Monkeypox Virus.

    PubMed

    Hutson, Christina L; Nakazawa, Yoshinori J; Self, Joshua; Olson, Victoria A; Regnery, Russell L; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L; Rocke, Tonie E; Osorio, Jorge E; Damon, Inger K; Carroll, Darin S

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108 pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species. PMID:26517724

  6. Didelphis marsupialis (common opossum): a potential reservoir host for zoonotic leishmaniasis in the metropolitan region of Belo Horizonte (Minas Gerais, Brazil).

    PubMed

    Schallig, Henk D F H; da Silva, Eduardo S; van der Meide, Wendy F; Schoone, Gerard J; Gontijo, Celia M F

    2007-01-01

    Identification of the zoonotic reservoir is important for leishmaniasis control program. A number of (wild) animal species may serve as reservoir hosts, including the opossum Didelphis marsupialis. A survey carried out in Didelphis specimens (n = 111) from the metropolitan region of Belo Horizonte, an important focus of human leishmaniasis in Brazil, is reported. All animals were serologically tested with indirect fluorescence antibody test (IFAT) and direct agglutination tests (DAT) based on L. (L.) donovani or L. (V.) braziliensis antigen. A sub-population (n = 20) was analyzed with polymerase chain reaction (PCR) for the presence of Leishmania-specific DNA. For species identification, PCR-positive samples were subjected to restriction enzyme fragment polymorphism (RFLP) analysis. Depending on the sero-diagnostic test employed, the sero-prevalence varied between 8.1% (9/111 animals positive with DAT test based on L. braziliensis antigen) and 21.6% (24/111 animals positive with IFAT). Five out of 20 samples analyzed with PCR tested positive for the presence of Leishmania-specific DNA. RFLP analysis revealed that two samples contained L. braziliensis complex DNA, one contained L. donovani complex DNA, and two samples could not be typed with the methodology used. These data suggest a potential role for the opossum as a reservoir host for zoonotic leishmaniasis in the region. PMID:17767408

  7. Laboratory investigations of African Pouched Rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox Virus

    USGS Publications Warehouse

    Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  8. Potential Mammalian Filovirus Reservoirs

    PubMed Central

    Carroll, Darin S.; Mills, James N.; Johnson, Karl M.

    2004-01-01

    Ebola and Marburg viruses are maintained in unknown reservoir species; spillover into human populations results in occasional human cases or epidemics. We attempted to narrow the list of possibilities regarding the identity of those reservoir species. We made a series of explicit assumptions about the reservoir: it is a mammal; it supports persistent, largely asymptomatic filovirus infections; its range subsumes that of its associated filovirus; it has coevolved with the virus; it is of small body size; and it is not a species that is commensal with humans. Under these assumptions, we developed priority lists of mammal clades that coincide distributionally with filovirus outbreak distributions and compared these lists with those mammal taxa that have been tested for filovirus infection in previous epidemiologic studies. Studying the remainder of these taxa may be a fruitful avenue for pursuing the identity of natural reservoirs of filoviruses. PMID:15663841

  9. Reservoir hosts of Leptospira inadai in India.

    PubMed

    Gangadhar, N L; Rajasekhar, M; Smythe, L D; Norris, M A; Symonds, M L; Dohnt, M F

    2000-12-01

    Isolation of Leptospira from the kidneys of Rattus rattus wroughtoni hinton, Rattus rattus rufescens, Bandicota bengalensis and Bandicota indica was attempted in Bangalore in southern India. In total, 296 spirochaetes were isolated from 1,348 kidney cultures (an isolation rate of 22%). A batch of fifty-six isolates from India was identified, based on serological and polymerase chain reaction analysis, of which twenty-three isolates were identified as L. inadai by the World Health Organization/Food and Agriculture Organization Collaborating Centre for Reference and Research on Leptospirosis, in Brisbane. This is the first record of isolation of L. inadai from rodents. The preponderance of L. inadai in four different species of rodents suggests that these animals could be the natural reservoir hosts of L. inadai, and raises a critical question as to the likely impact of this species of Leptospira on the renal carrier status of other Leptospira pathogenic to humans and animals in this part of India. Virulence studies conducted at the University of Trieste in Italy, revealed that isolates of L. inadai from India were moderately or totally serum resistant when subjected to a serum killing test. To establish the possible seroprevalence of this species in the population, the inclusion of L. inadai in the battery of leptospiral antigens used for sero-epidemiological studies is recommended. PMID:11107622

  10. Hantavirus reservoir hosts associated with peridomestic habitats in Argentina.

    PubMed Central

    Calderón, G.; Pini, N.; Bolpe, J.; Levis, S.; Mills, J.; Segura, E.; Guthmann, N.; Cantoni, G.; Becker, J.; Fonollat, A.; Ripoll, C.; Bortman, M.; Benedetti, R.; Enria, D.

    1999-01-01

    Five species of sigmodontine rodents have been identified in Argentina as the putative reservoirs of six circulating hantavirus genotypes. Two species of Oligoryzomys are associated with the genotypes causing hantavirus pulmonary syndrome, Oligoryzomys flavescens for Lechiguanas and O. longicaudatus for Andes and Oran genotypes. Reports of human cases of hantavirus pulmonary syndrome prompted rodent trapping (2,299 rodents of 32 species during 27,780 trap nights) at potential exposure sites in three disease-endemic areas. Antibody reactive to Sin Nombre virus was found in six species, including the known hantavirus reservoir species. Risk for peridomestic exposure to host species that carry recognized human pathogens was high in all three major disease-endemic areas. PMID:10603213

  11. Reservoir Host Immune Responses to Emerging Zoonotic Viruses

    PubMed Central

    Mandl, Judith N.; Ahmed, Rafi; Barreiro, Luis B.; Daszak, Peter; Epstein, Jonathan H.; Virgin, Herbert W.; Feinberg, Mark B.

    2015-01-01

    Zoonotic viruses, such as HIV, Ebola virus, coronaviruses, influenza A viruses, hantaviruses, or henipaviruses, can result in profound pathology in humans. In contrast, populations of the reservoir hosts of zoonotic pathogens often appear to tolerate these infections with little evidence of disease. Why are viruses more dangerous in one species than another? Immunological studies investigating quantitative and qualitative differences in the host-virus equilibrium in animal reservoirs will be key to answering this question, informing new approaches for treating and preventing zoonotic diseases. Integrating an understanding of host immune responses with epidemiological, ecological, and evolutionary insights into viral emergence will shed light on mechanisms that minimize fitness costs associated with viral infection, facilitate transmission to other hosts, and underlie the association of specific reservoir hosts with multiple emerging viruses. Reservoir host studies provide a rich opportunity for elucidating fundamental immunological processes and their underlying genetic basis, in the context of distinct physiological and metabolic constraints that contribute to host resistance and disease tolerance. PMID:25533784

  12. Does reservoir host mortality enhance transmission of West Nile virus?

    PubMed Central

    Foppa, Ivo M; Spielman, Andrew

    2007-01-01

    Background Since its 1999 emergence in New York City, West Nile virus (WNV) has become the most important and widespread cause of mosquito-transmitted disease in North America. Its sweeping spread from the Atlantic to the Pacific coast was accompanied by widespread mortality among wild birds, especially corvids. Only sporadic avian mortality had previously been associated with this infection in the Old World. Here, we examine the possibility that reservoir host mortality may intensify transmission, both by concentrating vector mosquitoes on remaining hosts and by preventing the accumulation of "herd immunity". Results Inspection of the Ross-Macdonald expression of the basic reproductive number (R0) suggests that this quantity may increase with reservoir host mortality. Computer simulation confirms this finding and indicates that the level of virulence is positively associated with the numbers of infectious mosquitoes by the end of the epizootic. The presence of reservoir incompetent hosts in even moderate numbers largely eliminated the transmission-enhancing effect of host mortality. Local host die-off may prevent mosquitoes to "waste" infectious blood meals on immune host and may thus facilitate perpetuation and spread of transmission. Conclusion Under certain conditions, host mortality may enhance transmission of WNV and similarly maintained arboviruses and thus facilitate their emergence and spread. The validity of the assumptions upon which this argument is built need to be empirically examined. PMID:17498307

  13. Potential methane reservoirs beneath Antarctica.

    PubMed

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387

  14. Reservoir Competence of Wildlife Host Species for Babesia microti

    PubMed Central

    Tibbetts, Michael; Strauss, Mia; Ostfeld, Richard S.; Keesing, Felicia

    2012-01-01

    Human babesiosis is an increasing health concern in the northeastern United States, where the causal agent, Babesia microti, is spread through the bite of infected Ixodes scapularis ticks. We sampled 10 mammal and 4 bird species within a vertebrate host community in southeastern New York to quantify reservoir competence (mean percentage of ticks infected by an individual host) using real-time PCR. We found reservoir competence levels >17% in white-footed mice (Peromyscus leucopus), raccoons (Procyon lotor), short-tailed shrews (Blarina brevicauda), and eastern chipmunks (Tamias striatus), and <6% but >0% in all other species, including all 4 bird species. Data on the relative contributions of multiple host species to tick infection with B. microti and level of genetic differentiation between B. microti strains transmitted by different hosts will help advance understanding of the spread of human babesiosis. PMID:23171673

  15. Reservoir competence of wildlife host species for Babesia microti.

    PubMed

    Hersh, Michelle H; Tibbetts, Michael; Strauss, Mia; Ostfeld, Richard S; Keesing, Felicia

    2012-12-01

    Human babesiosis is an increasing health concern in the northeastern United States, where the causal agent, Babesia microti, is spread through the bite of infected Ixodes scapularis ticks. We sampled 10 mammal and 4 bird species within a vertebrate host community in southeastern New York to quantify reservoir competence (mean percentage of ticks infected by an individual host) using real-time PCR. We found reservoir competence levels >17% in white-footed mice (Peromyscus leucopus), raccoons (Procyon lotor), short-tailed shrews (Blarina brevicauda), and eastern chipmunks (Tamias striatus), and <6% but >0% in all other species, including all 4 bird species. Data on the relative contributions of multiple host species to tick infection with B. microti and level of genetic differentiation between B. microti strains transmitted by different hosts will help advance understanding of the spread of human babesiosis. PMID:23171673

  16. Bats: Important Reservoir Hosts of Emerging Viruses

    PubMed Central

    Calisher, Charles H.; Childs, James E.; Field, Hume E.; Holmes, Kathryn V.; Schountz, Tony

    2006-01-01

    Bats (order Chiroptera, suborders Megachiroptera [“flying foxes”] and Microchiroptera) are abundant, diverse, and geographically widespread. These mammals provide us with resources, but their importance is minimized and many of their populations and species are at risk, even threatened or endangered. Some of their characteristics (food choices, colonial or solitary nature, population structure, ability to fly, seasonal migration and daily movement patterns, torpor and hibernation, life span, roosting behaviors, ability to echolocate, virus susceptibility) make them exquisitely suitable hosts of viruses and other disease agents. Bats of certain species are well recognized as being capable of transmitting rabies virus, but recent observations of outbreaks and epidemics of newly recognized human and livestock diseases caused by viruses transmitted by various megachiropteran and microchiropteran bats have drawn attention anew to these remarkable mammals. This paper summarizes information regarding chiropteran characteristics and information regarding 66 viruses that have been isolated from bats. From these summaries, it is clear that we do not know enough about bat biology; we are doing too little in terms of bat conservation; and there remain a multitude of questions regarding the role of bats in disease emergence. PMID:16847084

  17. The consequences of reservoir host eradication on disease epidemiology in animal communities.

    PubMed

    Al-Shorbaji, Farah; Roche, Benjamin; Gozlan, Rodolphe; Britton, Robert; Andreou, Demetra

    2016-01-01

    Non-native species have often been linked with introduction of novel pathogens that spill over into native communities, and the amplification of the prevalence of native parasites. In the case of introduced generalist pathogens, their disease epidemiology in the extant communities remains poorly understood. Here, Sphaerothecum destruens, a generalist fungal-like fish pathogen with bi-modal transmission (direct and environmental) was used to characterise the biological drivers responsible for disease emergence in temperate fish communities. A range of biotic factors relating to both the pathogen and the surrounding host communities were used in a novel susceptible-exposed-infectious-recovered (SEIR) model to test how these factors affected disease epidemiology. These included: (i) pathogen prevalence in an introduced reservoir host (Pseudorasbora parva); (ii) the impact of reservoir host eradication and its timing and (iii) the density of potential hosts in surrounding communities and their connectedness. These were modelled across 23 combinations and indicated that the spill-over of pathogen propagules via environmental transmission resulted in rapid establishment in adjacent fish communities (<1 year). Although disease dynamics were initially driven by environmental transmission in these communities, once sufficient numbers of native hosts were infected, the disease dynamics were driven by intra-species transmission. Subsequent eradication of the introduced host, irrespective of its timing (after one, two or three years), had limited impact on the long-term disease dynamics among local fish communities. These outputs reinforced the importance of rapid detection and eradication of non-native species, in particular when such species are identified as healthy reservoirs of a generalist pathogen. PMID:27165562

  18. The consequences of reservoir host eradication on disease epidemiology in animal communities

    PubMed Central

    Al-Shorbaji, Farah; Roche, Benjamin; Gozlan, Rodolphe; Britton, Robert; Andreou, Demetra

    2016-01-01

    Non-native species have often been linked with introduction of novel pathogens that spill over into native communities, and the amplification of the prevalence of native parasites. In the case of introduced generalist pathogens, their disease epidemiology in the extant communities remains poorly understood. Here, Sphaerothecum destruens, a generalist fungal-like fish pathogen with bi-modal transmission (direct and environmental) was used to characterise the biological drivers responsible for disease emergence in temperate fish communities. A range of biotic factors relating to both the pathogen and the surrounding host communities were used in a novel susceptible-exposed-infectious-recovered (SEIR) model to test how these factors affected disease epidemiology. These included: (i) pathogen prevalence in an introduced reservoir host (Pseudorasbora parva); (ii) the impact of reservoir host eradication and its timing and (iii) the density of potential hosts in surrounding communities and their connectedness. These were modelled across 23 combinations and indicated that the spill-over of pathogen propagules via environmental transmission resulted in rapid establishment in adjacent fish communities (<1 year). Although disease dynamics were initially driven by environmental transmission in these communities, once sufficient numbers of native hosts were infected, the disease dynamics were driven by intra-species transmission. Subsequent eradication of the introduced host, irrespective of its timing (after one, two or three years), had limited impact on the long-term disease dynamics among local fish communities. These outputs reinforced the importance of rapid detection and eradication of non-native species, in particular when such species are identified as healthy reservoirs of a generalist pathogen. PMID:27165562

  19. Ecological Niche Modeling of main reservoir hosts of zoonotic cutaneous leishmaniasis in Iran.

    PubMed

    Gholamrezaei, Mostafa; Mohebali, Mehdi; Hanafi-Bojd, Ahmad Ali; Sedaghat, Mohammad Mehdi; Shirzadi, Mohammad Reza

    2016-08-01

    Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, is a common zoonotic vector-borne disease in Iran. Close contact with infected reservoir hosts increases the probability of transmission of Leishmania parasite infections to susceptible humans. Four gerbil species (Rodentia: Gerbillidae) serve as the main reservoir hosts for ZCL in different endemic foci of Iran. These species include Rhombomys opimus, Meriones libycus, Meriones hurrianae and Tatera indica; while notable infection has been reported in Nesokia indica as well. The purpose of this study is to model the distribution of these reservoirs to identify the risk areas of ZCL. A data bank was developed including all published data during the period of 1970-2015. Maximum entropy model was used to find the most appropriate ecological niches for each species. The areas under curve obtained were 0.961, 0.927, 0.922, 0.997 and 0.899, instead of 1, for training test in R. opimus, M. libycus, T. indica, M. hurrianae and N. indica, respectively. The environmental variable with the highest gain when used in isolation was slope for R. opimus and N. indica, annual mean temperature for M. libycus, and seasonal precipitation for T. indica and M. hurrianae. Summation of presence probabilities for three main species, i.e., R. opimus, M. libycus and T. indica revealed favorable ecological niches in wide areas of 16 provinces. This is the first study to predict the distribution of ZCL reservoir hosts in Iran. Climatology and topography variables had high contributions toward the prediction of potential distribution of the main reservoir species; therefore, as climate changes, the models should be updated periodically with novel data, and the results should be used in disease-monitoring programs. PMID:27150212

  20. GLOBAL PATTERNS OF LEPTOSPIRA PREVALENCE IN VERTEBRATE RESERVOIR HOSTS.

    PubMed

    Andersen-Ranberg, Emilie U; Pipper, Christian; Jensen, Per M

    2016-07-01

    Leptospirosis is a widespread emerging bacterial zoonosis. As the transmission is believed to be predominantly waterborne, human incidence is expected to increase in conjunction with global climate change and associated extreme weather events. Providing more accurate predictions of human leptospirosis requires more detailed information on animal reservoirs that are the source of human infection. We evaluated the prevalence of Leptospira in vertebrates worldwide and its association with taxonomy, geographic region, host biology, ambient temperature, and precipitation patterns. A multivariate regression analysis with a meta-analysis-like approach was used to analyze compiled data extracted from 300 Leptospira-related peer reviewed papers. A fairly uniform Leptospira infection prevalence of about 15% was found in the majority of mammalian families. Higher prevalence was frequently associated with species occupying urban habitats, and this may explain why climatic factors were not significantly correlated with prevalence as consistently as expected. Across different approaches of the multiple regression analyses, the variables most frequently correlated with Leptospira infection prevalence were the host's ability to swim, minimum ambient temperature, and methodologic quality of the study. Prevalence in carnivores was not associated with any climatic variable, and the importance of environmental risk factors were indicated to be of lesser consequence in nonhuman mammals. The dataset is made available for further analysis. PMID:27187029

  1. Environmental influences on virus-host interactions in an Australian subtropical reservoir.

    PubMed

    Säwström, Christin; Pollard, Peter

    2012-02-01

    Viral and prokaryotic interactions in freshwaters have been investigated worldwide but there are few temporal studies in the tropics and none in the sub-tropics. In this 10-month study, we examined temporal changes in virus-host interactions and viral life cycles (lytic versus lysogenic) in relation to the prevailing environmental conditions in a subtropical water reservoir (Wivenhoe) in southeast Queensland, Australia. Heterotrophic prokaryotes and picocyanobacteria were positively correlated with concentrations of viruses throughout the study, indicating the presence of both bacteriophages and cyanophages in the reservoir. The percentage of heterotrophic prokaryotes and picocyanobacteria containing intracellular viruses (FVIC) ranged between 0.2% and 2.4% and did not vary significantly over the 10-month study, whereas lysogenic heterotrophic prokaryotes were only detected in the drier months of June and July. Spearman rank correlation analysis showed that the oxidative-reduction potential (ORP) of the water reservoir influenced the concentrations of viruses, heterotrophic prokaryotes and picocyanobacteria significantly, with low ORP offering a favourable environment for these components. There was a negative relationship between FVIC and rainfall suggesting the associated run-off altered virus-host interactions. Overall, our study provides novel information and inferences on how virus-host interactions in subtropical freshwaters might respond to changes in precipitation predicted to occur with global climate change. PMID:23757232

  2. Detection of urinary biomarkers in reservoir hosts of Leptospirosis by capillary electrophoresis mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogenic leptospires colonize the renal tubules of reservoir hosts of infection and are excreted via urine into the environment. Reservoir hosts include a wide range of domestic and wild animal species and include cattle, dogs and rats which can persistently excrete large numbers of pathogenic lep...

  3. Transmission or Within-Host Dynamics Driving Pulses of Zoonotic Viruses in Reservoir-Host Populations.

    PubMed

    Plowright, Raina K; Peel, Alison J; Streicker, Daniel G; Gilbert, Amy T; McCallum, Hamish; Wood, James; Baker, Michelle L; Restif, Olivier

    2016-08-01

    Progress in combatting zoonoses that emerge from wildlife is often constrained by limited knowledge of the biology of pathogens within reservoir hosts. We focus on the host-pathogen dynamics of four emerging viruses associated with bats: Hendra, Nipah, Ebola, and Marburg viruses. Spillover of bat infections to humans and domestic animals often coincides with pulses of viral excretion within bat populations, but the mechanisms driving such pulses are unclear. Three hypotheses dominate current research on these emerging bat infections. First, pulses of viral excretion could reflect seasonal epidemic cycles driven by natural variations in population densities and contact rates among hosts. If lifelong immunity follows recovery, viruses may disappear locally but persist globally through migration; in either case, new outbreaks occur once births replenish the susceptible pool. Second, epidemic cycles could be the result of waning immunity within bats, allowing local circulation of viruses through oscillating herd immunity. Third, pulses could be generated by episodic shedding from persistently infected bats through a combination of physiological and ecological factors. The three scenarios can yield similar patterns in epidemiological surveys, but strategies to predict or manage spillover risk resulting from each scenario will be different. We outline an agenda for research on viruses emerging from bats that would allow for differentiation among the scenarios and inform development of evidence-based interventions to limit threats to human and animal health. These concepts and methods are applicable to a wide range of pathogens that affect humans, domestic animals, and wildlife. PMID:27489944

  4. More Novel Hantaviruses and Diversifying Reservoir Hosts — Time for Development of Reservoir-Derived Cell Culture Models?

    PubMed Central

    Eckerle, Isabella; Lenk, Matthias; Ulrich, Rainer G.

    2014-01-01

    Due to novel, improved and high-throughput detection methods, there is a plethora of newly identified viruses within the genus Hantavirus. Furthermore, reservoir host species are increasingly recognized besides representatives of the order Rodentia, now including members of the mammalian orders Soricomorpha/Eulipotyphla and Chiroptera. Despite the great interest created by emerging zoonotic viruses, there is still a gross lack of in vitro models, which reflect the exclusive host adaptation of most zoonotic viruses. The usually narrow host range and genetic diversity of hantaviruses make them an exciting candidate for studying virus-host interactions on a cellular level. To do so, well-characterized reservoir cell lines covering a wide range of bat, insectivore and rodent species are essential. Most currently available cell culture models display a heterologous virus-host relationship and are therefore only of limited value. Here, we review the recently established approaches to generate reservoir-derived cell culture models for the in vitro study of virus-host interactions. These successfully used model systems almost exclusively originate from bats and bat-borne viruses other than hantaviruses. Therefore we propose a parallel approach for research on rodent- and insectivore-borne hantaviruses, taking the generation of novel rodent and insectivore cell lines from wildlife species into account. These cell lines would be also valuable for studies on further rodent-borne viruses, such as orthopox- and arenaviruses. PMID:24576845

  5. Western gray squirrel (Rodentia: Sciuridae): a primary reservoir host of Borrelia burgdorferi in Californian oak woodlands?

    PubMed

    Lane, Robert S; Mun, Jeomhee; Eisen, Rebecca J; Eisen, Lars

    2005-05-01

    In California, dense woodlands have been recognized as important biotopes where humans are exposed to the nymphal stage of the western blacklegged tick, Ixodes pacificus Cooley & Kohls, the primary vector of the Lyme disease spirochete Borrelia burgdorferi sensu stricto (s.s.), in the far-western United States. To identify the principal reservoir host(s) of this spirochete, and of closely related spirochetes in the B. burgdorferi sensu lato (s.l.) complex, in dense woodlands in Mendocino County, California, approximately 50 species of birds and mammals, including wood rats and kangaroo rats, were evaluated as potential hosts for vector ticks and borreliae in 2002 and 2003. Although polymerase chain reaction (PCR) and sequencing analyses revealed that many vertebrate species had been exposed to one or more members of the B. burgdorferi s.l. spirochetal complex, only the western gray squirrel, Sciurus griseus, fulfilled the major criteria for a reservoir host of B. burgdorferi s.s. Ear-punch biopsies from eight of 10 squirrels collected from five separate woodlands were PCR-positive for B. burgdorferi s.s., 47% of I. pacificus larvae (n = 64) and 31% of nymphs (n = 49) removed from squirrels contained B. burgdorferi s.l., and the engorgement status of I. pacificus larvae was associated positively with acquisition of spirochetes. Overall, 83 and 100% of the amplicons sequenced from PCR-positive I. pacificus larvae and nymphs, respectively, were identified as B. burgdorferi s.s, Among the five remaining positive I. pacificus larvae, three contained B. bissettii and two had uncharacterized B. burgdorferi s.l. Borrelia burgdorferi s.s. was detected in one of five larvae and zero of two nymphs of the Pacific Coast tick, Dermacentor occidentalis Marx, that likewise had been removed from squirrels. The rickettsial agent of human anaplasmosis, Anaplasma phagocytophilum, was detected in the blood or ear biopsies of two squirrels and in one (1.6%) of 64 I. pacificus larvae and

  6. Antigen variability in Anaplasma phagocytophilum during chronic infection of a reservoir host

    PubMed Central

    Foley, Patrick; Barbet, Anthony; Foley, Janet

    2012-01-01

    Anaplasma phagocytophilum is an obligately intracellular, tick-transmitted, bacterial pathogen of humans and other animals. In order to evade host immunity during the course of infection, A. phagocytophilum utilizes gene conversion to shuffle approximately 100 functional pseudogenes into a single expression cassette of the msp2(p44) gene, which encodes the major surface antigen, major surface protein 2 (Msp2). The role and extent of msp2(p44) recombination in a reservoir host for A. phagocytophilum have not been evaluated. In the current study, we explored patterns of recombination and expression site variability of the msp2(p44) gene in three chronically infected woodrats, a reservoir for the disease in the Western USA. All three woodrats developed persistent infection of at least 6 months duration; two of them maintained active infection for at least 8 months. In total, we detected the emergence of 60 unique msp2(p44) expression site variants with no common temporal patterns of expression site recombination among the three A. phagocytophilum populations. Both the strength of infection (i.e. pathogen load) and the genetic diversity of pseudogenes detected at the msp2(p44) expression site fluctuated periodically during the course of infection. An analysis of the genomic pseudogene exhaustion rate showed that the repertoire of pseudogenes available to the A. phagocytophilum population could in theory become depleted within a year. However, the apparent emergence of variant pseudogenes suggests that the pathogen could potentially evade host immunity indefinitely. Our findings suggest a tightly co-evolved relationship between A. phagocytophilum and woodrats in which the pathogen perpetually evades host immunity yet causes no detectable disease. PMID:22859615

  7. All ecosystems potentially host electrogenic bacteria.

    PubMed

    Chabert, Nicolas; Amin Ali, Oulfat; Achouak, Wafa

    2015-12-01

    Instead of requiring metal catalysts, MFCs utilize bacteria that oxidize organic matter and either transfer electrons to the anode or take electrons from the cathode. These devices are thus based on a wide microbial diversity that can convert a large array of organic matter components into sustainable and renewable energy. A wide variety of explored environments were found to host electrogenic bacteria, including extreme environments. In the present review, we describe how different ecosystems host electrogenic bacteria, as well as the physicochemical, electrochemical and biological parameters that control the currents from MFCs. We also report how using new molecular techniques allowed characterization of electrochemical biofilms and identification of potentially new electrogenic species. Finally we discuss these findings in the context of future research directions. PMID:26298511

  8. Bats as reservoir hosts of human bacterial pathogen, Bartonella mayotimonensis.

    PubMed

    Veikkolainen, Ville; Vesterinen, Eero J; Lilley, Thomas M; Pulliainen, Arto T

    2014-06-01

    A plethora of pathogenic viruses colonize bats. However, bat bacterial flora and its zoonotic threat remain ill defined. In a study initially conducted as a quantitative metagenomic analysis of the fecal bacterial flora of the Daubenton's bat in Finland, we unexpectedly detected DNA of several hemotrophic and ectoparasite-transmitted bacterial genera, including Bartonella. Bartonella spp. also were either detected or isolated from the peripheral blood of Daubenton's, northern, and whiskered bats and were detected in the ectoparasites of Daubenton's, northern, and Brandt's bats. The blood isolates belong to the Candidatus-status species B. mayotimonensis, a recently identified etiologic agent of endocarditis in humans, and a new Bartonella species (B. naantaliensis sp. nov.). Phylogenetic analysis of bat-colonizing Bartonella spp. throughout the world demonstrates a distinct B. mayotimonensis cluster in the Northern Hemisphere. The findings of this field study highlight bats as potent reservoirs of human bacterial pathogens. PMID:24856523

  9. The Lyme Disease Pathogen Has No Effect on the Survival of Its Rodent Reservoir Host

    PubMed Central

    Voordouw, Maarten J.; Lachish, Shelly; Dolan, Marc C.

    2015-01-01

    Zoonotic pathogens that cause devastating morbidity and mortality in humans may be relatively harmless in their natural reservoir hosts. The tick-borne bacterium Borrelia burgdorferi causes Lyme disease in humans but few studies have investigated whether this pathogen reduces the fitness of its reservoir hosts under natural conditions. We analyzed four years of capture-mark-recapture (CMR) data on a population of white-footed mice, Peromyscus leucopus, to test whether B. burgdorferi and its tick vector affect the survival of this important reservoir host. We used a multi-state CMR approach to model mouse survival and mouse infection rates as a function of a variety of ecologically relevant explanatory factors. We found no effect of B. burgdorferi infection or tick burden on the survival of P. leucopus. Our estimates of the probability of infection varied by an order of magnitude (0.051 to 0.535) and were consistent with our understanding of Lyme disease in the Northeastern United States. B. burgdorferi establishes a chronic avirulent infection in their rodent reservoir hosts because this pathogen depends on rodent mobility to achieve transmission to its sedentary tick vector. The estimates of B. burgdorferi infection risk will facilitate future theoretical studies on the epidemiology of Lyme disease. PMID:25688863

  10. Leishmania (L.) mexicana Infected Bats in Mexico: Novel Potential Reservoirs

    PubMed Central

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R.; Hidalgo-Mihart, Mircea; Marina, Carlos F.; Rebollar-Téllez, Eduardo A.; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N.; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

  11. Leishmania (L.) mexicana infected bats in Mexico: novel potential reservoirs.

    PubMed

    Berzunza-Cruz, Miriam; Rodríguez-Moreno, Ángel; Gutiérrez-Granados, Gabriel; González-Salazar, Constantino; Stephens, Christopher R; Hidalgo-Mihart, Mircea; Marina, Carlos F; Rebollar-Téllez, Eduardo A; Bailón-Martínez, Dulce; Balcells, Cristina Domingo; Ibarra-Cerdeña, Carlos N; Sánchez-Cordero, Víctor; Becker, Ingeborg

    2015-01-01

    Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico. Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees. The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported. Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis. Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA. We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues. The infected tissues showed no evidence of macroscopic lesions. Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae. The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco. Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice. We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector. Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology. PMID:25629729

  12. Novel methods for surveying reservoir hosts and vectors of Borrelia burgdorferi in Northern Minnesota

    NASA Astrophysics Data System (ADS)

    Seifert, Veronica Aili

    Lyme disease is the most prevalent tick-borne disease in North America and presents challenges to clinicians, researchers and the public in diagnosis, treatment and prevention. Lyme disease is caused by the spirochete, Borrelia burgdorferi, which is a zoonotic pathogen obligate upon hematophagous arthropod vectors and propagates in small mammal reservoir hosts. Identifying factors governing zoonotic diseases within regions of high-risk provides local health and agricultural agencies with necessary information to formulate public policy and implement treatment protocols to abate the rise and expansion of infectious disease outbreaks. In the United States, the documented primary reservoir host of Lyme disease is the white-footed mouse, Peromyscus leucopus, and the arthropod vector is the deer tick, Ixodes scapularis. Reducing the impact of Lyme disease will need novel methods for identifying both the reservoir host and the tick vector. The reservoir host, Peromyscus leucopus is difficult to distinguish from the virtually identical Peromyscus maniculatus that also is present in Northern Minnesota, a region where Lyme disease is endemic. Collection of the Ixodes tick, the Lyme disease vector, is difficult as this is season dependent and differs from year to year. This study develops new strategies to assess the extent of Borrelia burgdorferi in the local environment of Northern Minnesota. A selective and precise method to identify Peromyscus species was developed. This assay provides a reliable and definitive method to identify the reservoir host, Peromyscus leucopus from a physically identical and sympatric Peromyscus species, Peromyscus maniculatus. A new strategy to collect ticks for measuring the disbursement of Borrelia was employed. Students from local high schools were recruited to collect ticks. This strategy increased the available manpower to cover greater terrain, provided students with valuable experience in research methodology, and highlighted the

  13. Novel materials as potential infrared laser hosts

    NASA Astrophysics Data System (ADS)

    Sarkies, Julian Richard

    The work presented in this thesis has concentrated on an assessment and characterisation of potential laser host media which will only support low phonon or vibrational modes. This is a necessary criterion if systems in which the active ions are lanthanides are to be made to lase in the mid-infrared, as in conventional host media non- radiative processes dominate transitions in this region. Research has concentrated upon two main areas. Firstly a spectroscopic study of lanthanide doped PBr3/AlBr3/SbBr3 was undertaken. A detailed investigation and characterisation of the stable solution formation region was carried out. The doping levels achievable were seen to vary across the lanthanide series from a maximum 0.24mol% for praesodymium to a minimum 0.15mol% for ytterbium. Energies of the characteristic 4 f absorptions of the trivalent lanthanides were measured, along with their oscillator strengths. Judd-Ofelt parameters were found for several rare earths. Stimulated emission cross sections were found to be higher than in conventional glass hosts for certain transitions, such as 6.83 × 10 -20 cm2 for the 4F3/2 --> 4I11/2 transition in the Nd3+ doped liquid. This was verified both experimentally and by the Ladenburg-Fuchtbauer relation when compared to a standard silicate glass. The behaviour, both spectroscopic and physical, of the doped solutions was seen to change dramatically upon heating. Heating the solutions gave rise to higher crystallisation rates, but lower non-radiative relaxation rates. Waveguide and laser experiments were attempted in both bulk and capillary geometries, however material factors such as crystallisation and thermal lensing prevented laser action. Secondly, rare earth doped planar waveguides of zinc sulphide were prepared. A full characterisation of the way in which waveguide loss was affected by factors such as deposition rate, doping level and waveguide masking during evaporation was performed. Waveguide losses as low as 1.5dB/cm at 980nm

  14. Maximum ecological potential of tropical reservoirs and benthic invertebrate communities.

    PubMed

    Molozzi, Joseline; Feio, Maria João; Salas, Fuensanta; Marques, João Carlos; Callisto, Marcos

    2013-08-01

    The Reference Condition Approach (RCA) is now widely adopted as a basis for the evaluation of the ecological quality of water bodies. In accordance with the RCA, the integrity of communities found in a given location should be analyzed according to their deviation from the communities that would be expected in the absence of anthropogenic disturbances. The RCA was used here with the aim of defining the Maximum Ecological Potential (MEP) of tropical reservoirs located in the hydrographical basin of the Paraopeba River in the state of Minas Gerais, Brazil. Among the reservoirs, Serra Azul is used as a water supply and is located in a core area of environmental protection where tourism is not allowed and the native vegetation is conserved. The benthic macroinvertebrate communities at 90 sites located in three reservoirs were analyzed and sampled every 3 months over 2 years. The temporal patterns of the communities in the three reservoirs were analyzed (2nd-STAGE MDS and ANOSIM) and were not significantly related to seasonal fluctuations in temperature and precipitation. Twenty-eight sites belonging to the Serra Azul reservoir were selected to define the MEP of these reservoirs because these sites had the lowest human disturbance levels. The macroinvertebrate taxa present in the selected MEP sites are similar to those of natural lakes and different from the communities of disturbed sites. The biological classification of these sites revealed two groups with distinct macroinvertebrate communities. This distinction was related to climatic variables, bottom substrate type, the presence of gravel/boulders, coarse sand, silt, clay or muck, depth, and the shoreline substrate zone. These two subsets of biological communities and respective environmental conditions can serve as a basis for the future implementation of ecological quality monitoring programs for tropical reservoirs in the study area. This approach can also, however, be implemented in other geographic areas

  15. The Potential for Hosted Payloads at NASA

    NASA Technical Reports Server (NTRS)

    Andraschko, Mark; Antol, Jeffrey; Baize, Rosemary; Horan, Stephen; Neil, Doreen; Rinsland, Pamela; Zaiceva, Rita

    2012-01-01

    The 2010 National Space Policy encourages federal agencies to actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including...hosting government capabilities on commercial spacecraft. NASA's Science Mission Directorate has taken an important step towards this goal by adding an option for hosted payload responses to its recent Announcement of Opportunity (AO) for Earth Venture-2 missions. Since NASA selects a significant portion of its science missions through a competitive process, it is useful to understand the implications that this process has on the feasibility of successfully proposing a commercially hosted payload mission. This paper describes some of the impediments associated with proposing a hosted payload mission to NASA, and offers suggestions on how these impediments might be addressed. Commercially hosted payloads provide a novel way to serve the needs of the science and technology demonstration communities at a fraction of the cost of a traditional Geostationary Earth Orbit (GEO) mission. The commercial communications industry launches over 20 satellites to GEO each year. By exercising this repeatable commercial paradigm of privately financed access to space with proven vendors, NASA can achieve science goals at a significantly lower cost than the current dedicated spacecraft and launch vehicle approach affords. Commercial hosting could open up a new realm of opportunities for NASA science missions to make measurements from GEO. This paper also briefly describes two GEO missions recommended by the National Academies of Science Earth Science Decadal Survey, the Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission and the Precipitation and All-weather Temperature and Humidity (PATH) mission. Hosted payload missions recently selected for implementation by the Office of the Chief Technologist are also discussed. Finally, there are

  16. Improving the potential to produce oil from naturally fractured reservoirs

    SciTech Connect

    Perez, J.M.; Nighswander, J.; Berg, R.R.; Friedman, M.; Gangi, A.F.; Poston, S.W.

    1994-12-31

    A multi-phase effort that involved geological, geophysical, and petroleum engineering studies yielded an improved understanding of naturally fractured reservoirs and potential manners to improve the incidence of oil production from such reservoirs. Maps of fracture traces on bedding planes in the Austin Chalk outcrops showed organized trends of the fracture development and a hierarchical nature within the complete fracture system. Vertical Seismic Profile, VSP data has been used to estimate fracture orientation from shear-wave splitting. Well log responses in Austin Chalk wells have shown to be a reliable indicator of organic maturity. Well logs have also been used to calculate average resistivity of producing zones and to correlate resistivity with oil saturation and therefore with producing potential. Additionally, the use of carbonates water imbibition displacement processes has shown encouraging results of accelerating and increasing oil recovery of oil which do not have appreciable asphaltene contents.

  17. Can streaming potential data improve permeability estimates in EGS reservoirs?

    NASA Astrophysics Data System (ADS)

    Vogt, Christian; Klitzsch, Norbert

    2013-04-01

    We study the capability of streaming potential data to improve the estimation of permeability in fractured geothermal systems. To this end, we simulate a tracer experiment numerically carried out at the Enhanced Geothermal System (EGS) at Soultz-sous-Forêts, France, in 2005. The EGS is located in the Lower Rhine Graben. Here, at approximately 5000 m depth an engineered reservoir was established. The tracer circulation test provides information on hydraulic connectivity between the injection borehole GPK3 and the two production boreholes GPK2 and GPK4. Vogt et al. (2011) performed stochastic inversion approaches to estimate heterogeneous permeability at Soultz in an equivalent porous medium approach and studied the non-uniqueness of the possible pathways in the reservoir. They identified three different possible groups of pathway configurations between GPK2 and GPK3 and corresponding hydraulic properties. Using the Ensemble Kalman Fitler, Vogt et al. (2012) estimated permeability by updating sequentially an ensemble of heterogeneous Monte Carlo reservoir models. Additionally, this approach quantifies the heterogeneously distributed uncertainty. Here, we study whether considering hypothetical streaming potential (SP) data during the stochastic inversion can improve the determination of the hydraulic reservoir properties. In particular, we study whether the three groups are characterized uniquely by their corresponding SP signals along the boreholes and whether the Ensemble Kalman Filter fit could be improved by joint inversion of SP and tracer data. During the actual tracer test, no SP data were recorded. Therefore, this study is based on synthetic data. We find that SP data predominantly yields information on the near field of permeability around the wells. Therefore, SP observations along wells will not help to characterize large-scale reservoir flow paths. However, we investigate whether additional passive SP monitoring from deviated wells around the injection

  18. Over-wintering tadpoles of Mixophyes fasciolatus act as reservoir host for Batrachochytrium dendrobatidis.

    PubMed

    Narayan, Edward J; Graham, Clara; McCallum, Hamish; Hero, Jean-Marc

    2014-01-01

    Batrachochytrium dendrobatidis (Bd), a cutaneous amphibian fungus that causes the lethal disease chytridiomycosis, has been implicated as a cause of many amphibian declines. Bd can tolerate low temperatures with an optimum thermal range from 17-24°C. It has been shown that Bd infection may result in species extinction, avoiding the transmission threshold presented by density dependent transmission theory. Prevalence of Bd during autumn and winter has been shown to be as low as 0% in some species. It is currently unclear how Bd persists in field conditions and what processes result in carry-over between seasons. It has been hypothesised that overwintering tadpoles may host Bd between breeding seasons. The Great Barred Frog (Mixophyes fasciolatus) is a common, stable and widespread species in Queensland, Australia, and is known to carry Bd. Investigation into Bd infection of different life stages of M. fasciolatus during seasonally low prevalence may potentially reveal persistence and carry-over methods between seasons. Metamorphs, juveniles, and adults were swabbed for Bd infection over three months (between March and May, 2011) at 5 sites of varying altitude (66 m-790 m). A total of 93 swabs were analysed using Polymerase Chain Reaction (PCR) real-time analysis. PCR analysis showed 6 positive (1 excluded), 4 equivocal and 83 negative results for infection with Bd. Equivocal results were assumed to be negative using the precautionary principle. The 5 positive results consisted of 4 emerging (Gosner stage 43-45) metamorphs and 1 adult M. fasciolatus. Fisher's exact test on prevalence showed that the prevalence was significantly different between life stages. All positive results were sampled at high altitudes (790 m); however prevalence was not significantly different between altitudes. Infection of emerging metamorphs suggests that individuals were infected as tadpoles. We hypothesise that M. fasciolatus tadpoles carry Bd through seasons. Thus, Mixophyes

  19. Reservoir potential in Lower Devonian strata of Illinois

    SciTech Connect

    Whitaker, S.T. )

    1989-08-01

    Lower Devonian strata have considerable potential for hydrocarbon reserves in the Illinois basin; however, there has not yet been a major exploration effort for Lower Devonian reservoirs in the basin, nor has an adequate model been developed to explain distribution of these reservoirs. Due to the lack of exploration, production from these strata is presently limited to a few fields in south-central and southwestern Illinois. A review of data available at the Illinois State Geological Survey indicates that most Lower Devonian production in Illinois is from dolomitized cherty limestones in the Clear Creek Formation and Grassy Knob Chert. Minor production has also been noted in similar facies in the Bailey Limestone. Reservoir development within these strata is caused by dolomitization of slightly porous limestone beds and occurs in proximity to the beds' subcrop at the sub-Kaskaskia (pre-Middle Devonian) unconformity. The best reservoir development appears to be along paleotopographic highs on the Lower Devonian surface. Traps are most commonly formed where porous dolomitic beds, truncated at the sub-Kaskaskia unconformity are underlain by tight cherty limestones and overlain by tight Middle Devonian carbonates. Traps may also be formed downdip from porosity truncations where trends of porous Lower Devonian strata coincide with structural closures. The geometry and distribution of known reservoirs and traps in Lower Devonian carbonates indicate there may be several productive fairways in the basin. Exploration for and exploitation of these plays will depend on an increased understanding of Lower Devonian strata utilizing exploration models such as the one presented here.

  20. The raccoon (Procyon lotor) as potential rabies reservoir species in Germany: a risk assessment.

    PubMed

    Vos, Adriaan; Ortmann, Steffen; Kretzschmar, Antje S; Köhnemann, Berit; Michler, Frank

    2012-01-01

    Terrestrial wildlife rabies has been successfully eliminated from Germany predominantly as a result of the distribution of oral rabies vaccine baits. In case that wildlife rabies would re-emerge among its known reservoir species in Germany, swift action based on previous experiences could spatially and temporally limit and subsequently control such an outbreak. However, if rabies emerged in the raccoon population in Germany (Procyon lotor), there are no tools or local experience available to cope with this situation. This is especially worrisome for urban areas like Kassel (Hesse) due to the extremely high raccoon population density. A rabies outbreak among this potential reservoir host species in these urban settings could have a significant impact on public and animal health. PMID:22712420

  1. The armadillo as an animal model and reservoir host for Mycobacterium leprae.

    PubMed

    Balamayooran, Gayathriy; Pena, Maria; Sharma, Rahul; Truman, Richard W

    2015-01-01

    Apart from humans, armadillos are the only known natural hosts of Mycobacterium leprae. They are well developed as hosts for in vivo propagation of M leprae and are advancing as models for studying the pathogenesis of leprosy and translational research. Armadillos are immunologically intact. They exhibit the full Ridley-Jopling spectrum of histopathologic responses to M leprae and uniquely manifest extensive neurological involvement that closely recapitulates human leprosy. In addition, free-ranging armadillos in some regions are known to harbor a naturally occurring infection with M leprae, and zoonotic transmission between armadillos and humans has been implicated in a large number of new case presentations. We review the role of the armadillo as a model for leprosy and reservoir for human infection. PMID:25432816

  2. Potential on-shore and off-shore reservoirs for CO2 sequestration in Central Atlantic magmatic province basalts

    PubMed Central

    Goldberg, David S.; Kent, Dennis V.; Olsen, Paul E.

    2010-01-01

    Identifying locations for secure sequestration of CO2 in geological formations is one of our most pressing global scientific problems. Injection into basalt formations provides unique and significant advantages over other potential geological storage options, including large potential storage volumes and permanent fixation of carbon by mineralization. The Central Atlantic Magmatic Province basalt flows along the eastern seaboard of the United States may provide large and secure storage reservoirs both onshore and offshore. Sites in the South Georgia basin, the New York Bight basin, and the Sandy Hook basin offer promising basalt-hosted reservoirs with considerable potential for CO2 sequestration due to their proximity to major metropolitan centers, and thus to large industrial sources for CO2. Onshore sites are suggested for cost-effective characterization studies of these reservoirs, although offshore sites may offer larger potential capacity and additional long-term advantages for safe and secure CO2 sequestration. PMID:20080705

  3. Wildlife reservoirs of bovine tuberculosis worldwide: hosts, pathology, surveillance, and control.

    PubMed

    Fitzgerald, S D; Kaneene, J B

    2013-05-01

    Bovine tuberculosis due to Mycobacterium bovis is a zoonotic disease classically carried by cattle and spilling over into humans primarily by the ingestion of milk. However, in recent decades, there have been many endemic geographic localities where M. bovis has been detected infecting wildlife reservoirs, limiting the progress toward eradication of this disease from cattle. These include cervids in North America, badgers in Great Britain, feral pigs in Europe, brushtailed possums in New Zealand, and buffalo in South Africa. An overview of these wildlife hosts will provide insight into how these reservoirs maintain and spread the disease. In addition, the authors summarize the pathology, current ongoing methods for surveillance, and control. In many instances, it has proven to be more difficult to control or eradicate bovine tuberculosis in wild free-ranging species than in domesticated cattle. Furthermore, human influences have often contributed to the introduction and/or maintenance of the disease in wildlife species. Finally, some emerging themes regarding bovine tuberculosis establishment in wildlife hosts, as well as conclusions regarding management practices to assist in bovine tuberculosis control and eradication in wildlife, are offered. PMID:23169912

  4. Poultry as reservoir hosts for fishborne zoonotic trematodes in Vietnamese fish farms.

    PubMed

    Anh, Nguyen Thi Lan; Madsen, Henry; Dalsgaard, Anders; Phuong, Nguyen Thi; Thanh, Dao Thi Ha; Murrell, K Darwin

    2010-05-11

    Fishborne zoonotic trematodes (FZT) are widespread in Vietnam and Southeast Asia. It is now recognized that the risk of being infected from eating raw fish dishes applies not only to humans, but also to domestic animals (e.g., cats, dogs, and pigs) and fish-eating birds. The role of ducks and chicken, commonly raised on fish farms, as reservoir hosts, however, has not been adequately investigated. To study this question, chickens and ducks from integrated poultry-fish farms in Nghia Lac and Nghia Phu communes, Nam Dinh province, Vietnam were surveyed for FZT infections. A total of 50 ducks and 50 chickens from each commune were examined. Results revealed that 12% of chickens and 30% of ducks were infected with various species of trematodes, including two zoonotic species, Centrocestus formosanus and Echinostoma cinetorchis. Both occurred in chickens whereas only E. cinetorchis was found in ducks. Prevalence of these zoonotic species was 12% and 7% in ducks and chickens, respectively. Among other trematodes, Hypoderaeum conoideum, also a zoonotic fluke, was the most prevalent (20-30%). The feeding of snails and fish remains to poultry, either intentionally or by discharge of waste from the slaughter of ducks and chickens into the ponds, was identified as risk factors for trematode infection. The FZT species and low prevalence found in poultry in these communes indicate their role as reservoir hosts is minor. PMID:20149548

  5. Tacaribe Virus Causes Fatal Infection of An Ostensible Reservoir Host, the Jamaican Fruit Bat

    PubMed Central

    Cogswell-Hawkinson, Ann; Bowen, Richard; James, Stephanie; Gardiner, David; Calisher, Charles H.; Adams, Rick

    2012-01-01

    Tacaribe virus (TCRV) was first isolated from 11 Artibeus species bats captured in Trinidad in the 1950s during a rabies virus surveillance program. Despite significant effort, no evidence of infection of other mammals, mostly rodents, was found, suggesting that no other vertebrates harbored TCRV. For this reason, it was hypothesized that TCRV was naturally hosted by artibeus bats. This is in stark contrast to other arenaviruses with known hosts, all of which are rodents. To examine this hypothesis, we conducted experimental infections of Jamaican fruit bats (Artibeus jamaicensis) to determine whether they could be persistently infected without substantial pathology. We subcutaneously or intranasally infected bats with TCRV strain TRVL-11573, the only remaining strain of TCRV, and found that low-dose (104 50% tissue culture infective dose [TCID50]) inoculations resulted in asymptomatic and apathogenic infection and virus clearance, while high-dose (106 TCID50) inoculations caused substantial morbidity and mortality as early as 10 days postinfection. Uninoculated cage mates failed to seroconvert, and viral RNA was not detected in their tissues, suggesting that transmission did not occur. Together, these data suggest that A. jamaicensis bats may not be a reservoir host for TCRV. PMID:22379103

  6. Reservoir quality and potential, National Petroleum Reserve in Alaska

    SciTech Connect

    Mowatt, T.C.; Seidlitz, A.; Gibson, C.; Bascle, R.; Dygas, J. )

    1991-03-01

    As part of the reservoir management, resource assessment, and planning programs of the U.S. Bureau of Land Management in Alaska, the oil and gas resource potential of the National Petroleum Reserve in Alaska (NPRA) is undergoing review in light of new technical information, as well as changing national and international socioeconomic conditions. Emphasis is on integration of geological, petrophysical, geophysical, and engineering information to provide a refined, more technically substantive knowledge base for resource assessment and management. Brookian clastic rocks - in particular the Nanushuk Group and underlying Torok/Topagoruk intervals - have been the principal horizons of concern. Petrologic-mineralogic characteristics have been reinvestigated, related to petrophysical parameters and wireline log responses, and integrated with available engineering data, for key wells within and peripheral to the NPRA. Particular attention has been directed to diagenetic relationships, effects on reservoir quality, and implications for untested portions of this sizable basin. Similar efforts have been directed to pre-Brookian strata as well. Only some 127 exploratory wells (all but one under government aegis) have been drilled within or adjacent to NPRA (a geographic area on the order of 37,000 mi{sup 2} - about the size of the state of Indiana), many only to shallow depths. In almost every well drilled to any appreciable depth in the area, there have been manifestations of the presence of hydrocarbons. The results to date are actually rather promising from a qualitative geologic-geochemical perspective, in terms of potential for significant resources to be present.

  7. Potential Geographic Distribution of Hantavirus Reservoirs in Brazil

    PubMed Central

    de Oliveira, Stefan Vilges; Escobar, Luis E.; Peterson, A. Townsend; Gurgel-Gonçalves, Rodrigo

    2013-01-01

    Hantavirus cardiopulmonary syndrome is an emerging zoonosis in Brazil. Human infections occur via inhalation of aerosolized viral particles from excreta of infected wild rodents. Necromys lasiurus and Oligoryzomys nigripes appear to be the main reservoirs of hantavirus in the Atlantic Forest and Cerrado biomes. We estimated and compared ecological niches of the two rodent species, and analyzed environmental factors influencing their occurrence, to understand the geography of hantavirus transmission. N. lasiurus showed a wide potential distribution in Brazil, in the Cerrado, Caatinga, and Atlantic Forest biomes. Highest climate suitability for O. nigripes was observed along the Brazilian Atlantic coast. Maximum temperature in the warmest months and annual precipitation were the variables that most influence the distributions of N. lasiurus and O. nigripes, respectively. Models based on occurrences of infected rodents estimated a broader area of risk for hantavirus transmission in southeastern and southern Brazil, coinciding with the distribution of human cases of hantavirus cardiopulmonary syndrome. We found no demonstrable environmental differences among occurrence sites for the rodents and for human cases of hantavirus. However, areas of northern and northeastern Brazil are also apparently suitable for the two species, without broad coincidence with human cases. Modeling of niches and distributions of rodent reservoirs indicates potential for transmission of hantavirus across virtually all of Brazil outside the Amazon Basin. PMID:24391989

  8. A novel approach to assess the probability of disease eradication from a wild-animal reservoir host.

    PubMed

    Anderson, D P; Ramsey, D S L; Nugent, G; Bosson, M; Livingstone, P; Martin, P A J; Sergeant, E; Gormley, A M; Warburton, B

    2013-07-01

    Surveying and declaring disease freedom in wildlife is difficult because information on population size and spatial distribution is often inadequate. We describe and demonstrate a novel spatial model of wildlife disease-surveillance data for predicting the probability of freedom of bovine tuberculosis (caused by Mycobacterium bovis) in New Zealand, in which the introduced brushtail possum (Trichosurus vulpecula) is the primary wildlife reservoir. Using parameters governing home-range size, probability of capture, probability of infection and spatial relative risks of infection we employed survey data on reservoir hosts and spillover sentinels to make inference on the probability of eradication. Our analysis revealed high sensitivity of model predictions to parameter values, which demonstrated important differences in the information contained in survey data of host-reservoir and spillover-sentinel species. The modelling can increase cost efficiency by reducing the likelihood of prematurely declaring success due to insufficient control, and avoiding unnecessary costs due to excessive control and monitoring. PMID:23339965

  9. Cumberlandian Mollusk Conservation Program. Activity 2: potential fish hosts

    SciTech Connect

    Koch, L.M.; Hickman, G.D.; Swor, C.T.

    1986-02-01

    Fish species from sand/gravel substrates and from rubble substrates which are the most likely hosts for Cumberlandian mussel fauna, C. caelata and Q. intermedia, from the Clinch, Duck, Elk, and Powell Rivers are reported. Infection with mollusk glochidia was used with overlap and occurrences to develop a ranking of each species potential as a suitable host for Cumberlandian mollusks. 12 ref., 4 figs., 9 tabs.

  10. Ecological connectivity of Trypanosoma cruzi reservoirs and Triatoma pallidipennis hosts in an anthropogenic landscape with endemic Chagas disease.

    PubMed

    Ramsey, Janine M; Gutiérrez-Cabrera, Ana E; Salgado-Ramírez, Liliana; Peterson, A Townsend; Sánchez-Cordero, Victor; Ibarra-Cerdeña, Carlos N

    2012-01-01

    Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats. PMID:23049923

  11. Ecological Connectivity of Trypanosoma cruzi Reservoirs and Triatoma pallidipennis Hosts in an Anthropogenic Landscape with Endemic Chagas Disease

    PubMed Central

    Ramsey, Janine M.; Gutiérrez-Cabrera, Ana E.; Salgado-Ramírez, Liliana; Peterson, A. Townsend; Sánchez-Cordero, Victor; Ibarra-Cerdeña, Carlos N.

    2012-01-01

    Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats. PMID:23049923

  12. Utility of Filter Paper for Preserving Insects, Bacteria, and Host Reservoir DNA for Molecular Testing

    PubMed Central

    Karimian, F; Sedaghat, MM; Oshaghi, MA; Mohtarami, F; Dehkordi, A Sanei; Koosha, M; Akbari, S; Hashemi-Aghdam, SS

    2011-01-01

    Background: Appropriate methodology for storage biological materials, extraction of DNA, and proper DNA preservation is vital for studies involving genetic analysis of insects, bacteria, and reservoir hosts as well as for molecular diagnostics of pathogens carried by vectors and reservoirs. Here we tried to evaluate the utility of a simple filter paper-based for storage of insects, bacteria, rodent, and human DNAs using PCR assays. Methods: Total body or haemolymph of individual mosquitoes, sand flies or cockroaches squashed or placed on the paper respectively. Extracted DNA of five different bacteria species as well as blood specimens of human and great gerbil Rhombomys opimus was pipetted directly onto filter paper. The papers were stored in room temperature up to 12 months during 2009 until 2011. At monthly intervals, PCR was conducted using a 1-mm disk from the DNA impregnated filter paper as target DNA. PCR amplification was performed against different target genes of the organisms including the ITS2-rDNA of mosquitoes, mtDNA-COI of the sand flies and cockroaches, 16SrRNA gene of the bacteria, and the mtDNA-CytB of the vertebrates. Results: Successful PCR amplification was observed for all of the specimens regardless of the loci, taxon, or time of storage. The PCR amplification were ranged from 462 to 1500 bp and worked well for the specified target gene/s. Time of storage did not affect the amplification up to one year. Conclusion: The filter paper method is a simple and economical way to store, to preserve, and to distribute DNA samples for PCR analysis. PMID:22808417

  13. The rabbit as a new reservoir host of enterohemorrhagic Escherichia coli.

    PubMed

    García, Alexis; Fox, James G

    2003-12-01

    We investigated the prevalence of enterohemorrhagic Escherichia coli (EHEC) in rabbits acquired from two commercial vendors and a local petting zoo. Fecal samples from 34 Dutch Belted (DB) and 15 New Zealand White (NZW) rabbits were cultured; and isolates were biotyped, serotyped, tested by polymerase chain reaction (PCR), and genotyped by repetitive-element sequence-based PCR (Rep-PCR). Seven (25%) of 28 DB rabbits acquired from one commercial source were positive for EHEC, including O153:H- and O153:H7. One (9%) of 11 NZW rabbits from the same source was positive for eae-, stx1+ O153 strains. In contrast, six DB rabbits from another commercial source and four rabbits from a petting zoo were negative for EHEC. Rep-PCR demonstrated that the O153 EHEC and O145 enteropathogenic E. coli were two distinct clones. Our study indicates that rabbits are a new reservoir host of EHEC that may pose a zoonotic risk for humans. PMID:14720401

  14. The Rabbit as a New Reservoir Host of Enterohemorrhagic Escherichia coli

    PubMed Central

    Fox, James G.

    2003-01-01

    We investigated the prevalence of enterohemorrhagic Escherichia coli (EHEC) in rabbits acquired from two commercial vendors and a local petting zoo. Fecal samples from 34 Dutch Belted (DB) and 15 New Zealand White (NZW) rabbits were cultured; and isolates were biotyped, serotyped, tested by polymerase chain reaction (PCR), and genotyped by repetitive-element sequence–based PCR (Rep-PCR). Seven (25%) of 28 DB rabbits acquired from one commercial source were positive for EHEC, including O153:H- and O153:H7. One (9%) of 11 NZW rabbits from the same source was positive for eae-, stx1+ O153 strains. In contrast, six DB rabbits from another commercial source and four rabbits from a petting zoo were negative for EHEC. Rep-PCR demonstrated that the O153 EHEC and O145 enteropathogenic E. coli were two distinct clones. Our study indicates that rabbits are a new reservoir host of EHEC that may pose a zoonotic risk for humans. PMID:14720401

  15. Capsicum Species: Symptomless Hosts and Reservoirs of Tomato yellow leaf curl virus.

    PubMed

    Polston, J E; Cohen, L; Sherwood, T A; Ben-Joseph, R; Lapidot, M

    2006-05-01

    ABSTRACT Five Capsicum species were tested for susceptibility to Tomato yellow leaf curl virus (TYLCV) and the mild strain of TYLCV (TYLCV-Mld). TYLCV was able to infect 30 of 55 genotypes of C. annuum, one of six genotypes of C. chinense, one of two genotypes of C. baccatum, and the only genotype of C. frutescens tested but was unable to infect the one genotype of C. pubescens tested. This is the first evidence for the susceptibility of C. baccatum, C. chinense, and C. frutescens to TYLCV. Unlike TYLCV isolates, TYLCV-Mld was unable to infect C. chinense. No host differences were observed between the Israeli and Florida isolates of TYLCV. None of the Capsicum species showed symptoms after infection with TYLCV or TYLCV-Mld. TYLCV was detected in fruits of C. annuum, but whiteflies were unable to transmit virus from fruits to plants. White-flies were able to transmit both TYLCV and TYLCV-Mld from infected pepper plants to tomato plants. Pepper plants in research plots were found infected with TYLCV at rates as much as 100%. These data demonstrate the ability of some genotypes of pepper to serve as reservoirs for the acquisition and transmission of TYLCV and TYLCV-Mld. PMID:18944303

  16. Bioremediation potential of microorganisms derived from petroleum reservoirs.

    PubMed

    Dellagnezze, Bruna Martins; de Sousa, Gabriel Vasconcelos; Martins, Laercio Lopes; Domingos, Daniela Ferreira; Limache, Elmer E G; de Vasconcellos, Suzan Pantaroto; da Cruz, Georgiana Feitosa; de Oliveira, Valéria Maia

    2014-12-15

    Bacterial strains and metagenomic clones, both obtained from petroleum reservoirs, were evaluated for petroleum degradation abilities either individually or in pools using seawater microcosms for 21 days. Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses were carried out to evaluate crude oil degradation. The results showed that metagenomic clones 1A and 2B were able to biodegrade n-alkanes (C14 to C33) and isoprenoids (phytane and pristane), with rates ranging from 31% to 47%, respectively. The bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 showed higher rates reaching 99% after 21 days. The metagenomic clone pool biodegraded these compounds at rates ranging from 11% to 45%. Regarding aromatic compound biodegradation, metagenomic clones 2B and 10A were able to biodegrade up to 94% of phenanthrene and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 55% to 70% after 21 days, while the bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 were able to biodegrade 63% and up to 99% of phenanthrene, respectively, and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 23% to 99% after 21 days. In this work, isolated strains as well as metagenomic clones were capable of degrading several petroleum compounds, revealing an innovative strategy and a great potential for further biotechnological and bioremediation applications. PMID:25457810

  17. Influenza Virus Reservoirs and Intermediate Hosts: Dogs, Horses, and New Possibilities for Influenza Virus Exposure of Humans

    PubMed Central

    Murcia, Pablo R.; Holmes, Edward C.

    2014-01-01

    Influenza A virus (IAV) infections in hosts outside the main aquatic bird reservoirs occur periodically. Although most such cross-species transmission events result in limited onward transmission in the new host, sustained influenza outbreaks have occurred in poultry and in a number of mammalian species, including humans, pigs, horses, seals, and mink. Recently, two distinct strains of IAV have emerged in domestic dogs, with each circulating widely for several years. Here, we briefly outline what is known about the role of intermediate hosts in influenza emergence, summarize our knowledge of the new canine influenza viruses (CIVs) and how they provide key new information on the process of host adaptation, and assess the risk these viruses pose to human populations. PMID:25540375

  18. Influenza virus reservoirs and intermediate hosts: dogs, horses, and new possibilities for influenza virus exposure of humans.

    PubMed

    Parrish, Colin R; Murcia, Pablo R; Holmes, Edward C

    2015-03-01

    Influenza A virus (IAV) infections in hosts outside the main aquatic bird reservoirs occur periodically. Although most such cross-species transmission events result in limited onward transmission in the new host, sustained influenza outbreaks have occurred in poultry and in a number of mammalian species, including humans, pigs, horses, seals, and mink. Recently, two distinct strains of IAV have emerged in domestic dogs, with each circulating widely for several years. Here, we briefly outline what is known about the role of intermediate hosts in influenza emergence, summarize our knowledge of the new canine influenza viruses (CIVs) and how they provide key new information on the process of host adaptation, and assess the risk these viruses pose to human populations. PMID:25540375

  19. Essential Role of Invasin for Colonization and Persistence of Yersinia enterocolitica in Its Natural Reservoir Host, the Pig

    PubMed Central

    Schaake, Julia; Drees, Anna; Grüning, Petra; Uliczka, Frank; Pisano, Fabio; Thiermann, Tanja; von Altrock, Alexandra; Seehusen, Frauke

    2014-01-01

    In this study, an oral minipig infection model was established to investigate the pathogenicity of Yersinia enterocolitica bioserotype 4/O:3. O:3 strains are highly prevalent in pigs, which are usually symptomless carriers, and they represent the most common cause of human yersiniosis. To assess the pathogenic potential of the O:3 serotype, we compared the colonization properties of Y. enterocolitica O:3 with O:8, a highly mouse-virulent Y. enterocolitica serotype, in minipigs and mice. We found that O:3 is a significantly better colonizer of swine than is O:8. Coinfection studies with O:3 mutant strains demonstrated that small variations within the O:3 genome leading to higher amounts of the primary adhesion factor invasin (InvA) improved colonization and/or survival of this serotype in swine but had only a minor effect on the colonization of mice. We further demonstrated that a deletion of the invA gene abolished long-term colonization in the pigs. Our results indicate a primary role for invasin in naturally occurring Y. enterocolitica O:3 infections in pigs and reveal a higher adaptation of O:3 than O:8 strains to their natural pig reservoir host. PMID:24343656

  20. Pteropid bats are confirmed as the reservoir hosts of henipaviruses: a comprehensive experimental study of virus transmission.

    PubMed

    Halpin, Kim; Hyatt, Alex D; Fogarty, Rhys; Middleton, Deborah; Bingham, John; Epstein, Jonathan H; Rahman, Sohayati Abdul; Hughes, Tom; Smith, Craig; Field, Hume E; Daszak, Peter

    2011-11-01

    Bats of the genus Pteropus have been identified as the reservoir hosts for the henipaviruses Hendra virus (HeV) and Nipah virus (NiV). The aim of these studies was to assess likely mechanisms for henipaviruses transmission from bats. In a series of experiments, Pteropus bats from Malaysia and Australia were inoculated with NiV and HeV, respectively, by natural routes of infection. Despite an intensive sampling strategy, no NiV was recovered from the Malaysian bats and HeV was reisolated from only one Australian bat; no disease was seen. These experiments suggest that opportunities for henipavirus transmission may be limited; therefore, the probability of a spillover event is low. For spillover to occur, a range of conditions and events must coincide. An alternate assessment framework is required if we are to fully understand how this reservoir host maintains and transmits not only these but all viruses with which it has been associated. PMID:22049055

  1. Does influenza A virus infection affect movement behaviour during stopover in its wild reservoir host?

    PubMed Central

    Bengtsson, Daniel; Safi, Kamran; Avril, Alexis; Fiedler, Wolfgang; Wikelski, Martin; Gunnarsson, Gunnar; Elmberg, Johan; Tolf, Conny; Olsen, Björn; Waldenström, Jonas

    2016-01-01

    The last decade has seen a surge in research on avian influenza A viruses (IAVs), in part fuelled by the emergence, spread and potential zoonotic importance of highly pathogenic virus subtypes. The mallard (Anas platyrhynchos) is the most numerous and widespread dabbling duck in the world, and one of the most important natural hosts for studying IAV transmission dynamics. In order to predict the likelihood of IAV transmission between individual ducks and to other hosts, as well as between geographical regions, it is important to understand how IAV infection affects the host. In this study, we analysed the movements of 40 mallards equipped with GPS transmitters and three-dimensional accelerometers, of which 20 were naturally infected with low pathogenic avian influenza virus (LPAIV), at a major stopover site in the Northwest European flyway. Movements differed substantially between day and night, as well as between mallards returning to the capture site and those feeding in natural habitats. However, movement patterns did not differ between LPAIV infected and uninfected birds. Hence, LPAIV infection probably does not affect mallard movements during stopover, with high possibility of virus spread along the migration route as a consequence. PMID:26998334

  2. Bayou virus-associated hantavirus pulmonary syndrome in Eastern Texas: identification of the rice rat, Oryzomys palustris, as reservoir host.

    PubMed Central

    Torrez-Martinez, N.; Bharadwaj, M.; Goade, D.; Delury, J.; Moran, P.; Hicks, B.; Nix, B.; Davis, J. L.; Hjelle, B.

    1998-01-01

    We describe the third known case of hantavirus pulmonary syndrome (HPS) due to Bayou virus, from Jefferson County, Texas. By using molecular epidemiologic methods, we show that rice rats (Oryzomys palustris) are frequently infected with Bayou virus and that viral RNA sequences from HPS patients are similar to those from nearby rice rats. Bayou virus is associated with O. palustris; this rodent appears to be its predominant reservoir host. PMID:9452404

  3. Integrated geologic and engineering determination of oil-reserve-growth potential in carbonate reservoirs

    SciTech Connect

    Holtz, M.H.; Rupel, S.C.; Hocott, C.R. )

    1992-11-01

    Leonardian restricted-platform carbonate reservoirs in the Permian Basin in West Texas and southeastern New Mexico exhibit abnormally low recovery efficiencies. Cumulative production form these mature reservoirs is only 18% of the original oil in place (OOIP), or about one-half the average recovery efficiency of Permian Basin carbonate reservoirs. Low recovery efficiency is directly related to high degrees of vertical and lateral facies heterogeneity caused by high-frequency, cyclic sedimentation in low-energy, carbonate platform environments and by equally complex postdepositional diagenesis. This paper reports that because of their geologic complexity, these reservoirs have high reserve-growth potential.

  4. Exploring the Spatio-Temporal Dynamics of Reservoir Hosts, Vectors, and Human Hosts of West Nile Virus: A Review of the Recent Literature

    PubMed Central

    Ozdenerol, Esra; Taff, Gregory N.; Akkus, Cem

    2013-01-01

    Over the last two decades West Nile Virus (WNV) has been responsible for significant disease outbreaks in humans and animals in many parts of the World. Its extremely rapid global diffusion argues for a better understanding of its geographic extent. The purpose of this inquiry was to explore spatio-temporal patterns of WNV using geospatial technologies to study populations of the reservoir hosts, vectors, and human hosts, in addition to the spatio-temporal interactions among these populations. Review of the recent literature on spatial WNV disease risk modeling led to the conclusion that numerous environmental factors might be critical for its dissemination. New Geographic Information Systems (GIS)-based studies are monitoring occurrence at the macro-level, and helping pinpoint areas of occurrence at the micro-level, where geographically-targeted, species-specific control measures are sometimes taken and more sophisticated methods of surveillance have been used. PMID:24284356

  5. Discovering potential sources of emerging pathogens: South America is a reservoir of generalist avian blood parasites.

    PubMed

    Moens, Michaël A J; Pérez-Tris, Javier

    2016-01-01

    Generalist pathogens are capable of infecting a wide range of host species, and may pose serious disease emergence threats if accidentally moved outside their native areas. To date little effort has been devoted to identifying geographic areas that may act as reservoirs of generalist pathogens. According to current theory, where host diversity is high, parasite specialisation in one host species may be penalised by reduced host availability, while generalist parasites may benefit from the exploitation of various host species. Therefore natural selection could favor generalist parasites where host diversity is high. Here we explored if, in a highly diverse bird community in Ecuador, a generalist strategy is promoted among local Haemoproteus and Plasmodium blood-borne parasites compared with similar parasite communities throughout the world. We reconstructed the phylogenetic relationships of every parasite lineage in order to understand the evolution of host specificity in this megadiverse area. We found high levels of host generalisation for both parasite genera, and the mean host range of the Haemoproteus community in Ecuador was significantly higher than other parasite communities in other areas outside the Neotropics. Generalist Haemoproteus parasites in this bird community had diverse phylogenetic ancestry, were closely related to specialist parasites and were apparently endemic to the Amazon, showing that different parasites have independently evolved into host generalists in this region. Finally we show that Haemoproteus communities in Ecuador and South America are more generalist than in temperate areas, making this continent a hotspot of generalist Haemoproteus parasites for wild birds. PMID:26348660

  6. Viral metagenomics demonstrates that domestic pigs are a potential reservoir for Ndumu virus

    PubMed Central

    2012-01-01

    Background The rising demand for pork has resulted in a massive expansion of pig production in Uganda. This has resulted in increased contact between humans and pigs. Pigs can act as reservoirs for emerging infectious diseases. Therefore identification of potential zoonotic pathogens is important for public health surveillance. In this study, during a routine general surveillance for African swine fever, domestic pigs from Uganda were screened for the presence of RNA and DNA viruses using a high-throughput pyrosequencing method. Findings Serum samples from 16 domestic pigs were collected from five regions in Uganda and pooled accordingly. Genomic DNA and RNA were extracted and sequenced on the 454 GS-FLX platform. Among the sequences assigned to a taxon, 53% mapped to the domestic pig (Sus scrofa). African swine fever virus, Torque teno viruses (TTVs), and porcine endogenous retroviruses were identified. Interestingly, two pools (B and C) of RNA origin had sequences that showed 98% sequence identity to Ndumu virus (NDUV). None of the reads had identity to the class Insecta indicating that these sequences were unlikely to result from contamination with mosquito nucleic acids. Conclusions This is the first report of the domestic pig as a vertebrate host for Ndumu virus. NDUV had been previously isolated only from culicine mosquitoes. NDUV therefore represents a potential zoonotic pathogen, particularly given the increasing risk of human-livestock-mosquito contact. PMID:23006778

  7. The ecology of cutaneous leishmaniasis in Nizzana, Israel: infection patterns in the reservoir host, and epidemiological implications.

    PubMed

    Wasserberg, G; Abramsky, Z; Anders, G; El-Fari, M; Schoenian, G; Schnur, L; Kotler, B P; Kabalo, I; Warburg, A

    2002-02-01

    We conducted an extensive interdisciplinary study in an emerging focus of cutaneous leishmaniasis in the Western Negev Desert of Israel between July 1998 and February 2000. The aims of the this study were to determine (1) the reservoir hosts, (2) the distribution of the pathogen within the host range, (3) the associations of host, vector, and pathogen within defined habitats, (4) the demographic distribution of the pathogen within the host populations, and (5) to apply the newly acquired epizootiological data to explain morbidity patterns in humans. Fourteen square (60 m width) sampling plots were delimited in three types of habitats each with a different kind of substrate: loess, sand, and sand-loess ecotone. Rodents and sand flies were trapped and several environmental variables were measured. Leishmania infections in rodents were detected microscopically in stained smears of ear tissue and by a Leishmania-specific polymerase chain reaction. Results indicate that, contrary to previous reports, Psammomys obesus and not Meriones crassus is the main reservoir host in the region. Additional rodents (12 Gerbillus dasyurus and two M. crassus) were also found positive for Leishmania DNA. Prevalence of Leishmania infections amongst P. obesus was highest in loess habitats (65%), intermediate in the sandy-loess ecotone (20%), and 0% in the sandy habitats. Psammomys obesus individuals in the loess habitat of the Nizzana ruins were larger, on average (probably older), than those in the sandy habitat of the Mt. Keren junction. Sand fly density was positively correlated to soil moisture being higher in the relatively humid plots of Nizzana ruins and much lower in the drier sandy soil of Mt. Keren. Elucidation of fundamental ecological factors affecting this disease has helped explain an apparent discrepancy between the distribution of the disease in the zoonotic system and among humans. PMID:11812490

  8. Interaction of Bovine Peripheral Blood Polymorphonuclear Cells and Leptospira Species; Innate Responses in the Natural Bovine Reservoir Host

    PubMed Central

    Wilson-Welder, Jennifer H.; Frank, Ami T.; Hornsby, Richard L.; Olsen, Steven C.; Alt, David P.

    2016-01-01

    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and Leptospira interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia, and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs) and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2) was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of Leptospira strains

  9. Interaction of Bovine Peripheral Blood Polymorphonuclear Cells and Leptospira Species; Innate Responses in the Natural Bovine Reservoir Host.

    PubMed

    Wilson-Welder, Jennifer H; Frank, Ami T; Hornsby, Richard L; Olsen, Steven C; Alt, David P

    2016-01-01

    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and Leptospira interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia, and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs) and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2) was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of Leptospira strains

  10. Quantitative evaluation of oil-leg potential in gas reservoirs

    SciTech Connect

    Lisk, M.; Krieger, F.W.; Eadington, P.J.; O`Brien, G.W.

    1996-12-31

    Oil bearing fluid inclusions in sandstone represent hidden oil shows. The frequency of quartz grains containing these inclusions (GOI number) reflects maximum palaeo-oil saturation irrespective of the present fluid phase. In this way fluid inclusion data can be used to both identify palaeo-oil columns and to map original oil water contacts (OWC) in wells where oil has been displaced by later gas charge. Studies conducted on gas fields from the North West Shelf of Australia have shown that substantial oil columns were once present. Moreover, detailed GOI mapping has been used to define the location of the original OWC in these reservoirs allowing the height of the palaeo-column to be determined and an estimate to be made of original oil in place (OOIP). At Oliver-1 in the Timor Sea the reservoir is presently filled to spill with a 164m gas, and 14.5m oil, column. GOI mapping has, however, delineated a 96m thick palaeo-oil column within the gas leg. This is almost seven times thicker than the present oil leg which suggests that perhaps 170-190 million barrels of oil were displaced from this structure. In the Pepper gas field in the Carnarvon Basin GOI mapping has demonstrated the presence of a gross palaeo-oil column between 15 and 30 m thick, suggesting that between about 50 and 70 million barrels of oil has been displaced. This is more oil than that reservoired in any of the surrounding oil discoveries, which emphasizes the importance, from an exploration standpoint, of defining these remigration pathways.

  11. Quantitative evaluation of oil-leg potential in gas reservoirs

    SciTech Connect

    Lisk, M.; Krieger, F.W.; Eadington, P.J. ); O'Brien, G.W. )

    1996-01-01

    Oil bearing fluid inclusions in sandstone represent hidden oil shows. The frequency of quartz grains containing these inclusions (GOI number) reflects maximum palaeo-oil saturation irrespective of the present fluid phase. In this way fluid inclusion data can be used to both identify palaeo-oil columns and to map original oil water contacts (OWC) in wells where oil has been displaced by later gas charge. Studies conducted on gas fields from the North West Shelf of Australia have shown that substantial oil columns were once present. Moreover, detailed GOI mapping has been used to define the location of the original OWC in these reservoirs allowing the height of the palaeo-column to be determined and an estimate to be made of original oil in place (OOIP). At Oliver-1 in the Timor Sea the reservoir is presently filled to spill with a 164m gas, and 14.5m oil, column. GOI mapping has, however, delineated a 96m thick palaeo-oil column within the gas leg. This is almost seven times thicker than the present oil leg which suggests that perhaps 170-190 million barrels of oil were displaced from this structure. In the Pepper gas field in the Carnarvon Basin GOI mapping has demonstrated the presence of a gross palaeo-oil column between 15 and 30 m thick, suggesting that between about 50 and 70 million barrels of oil has been displaced. This is more oil than that reservoired in any of the surrounding oil discoveries, which emphasizes the importance, from an exploration standpoint, of defining these remigration pathways.

  12. Low permeability Neogene lithofacies in Northern Croatia as potential unconventional hydrocarbon reservoirs

    NASA Astrophysics Data System (ADS)

    Malvić, Tomislav; Sučić, Antonija; Cvetković, Marko; Resanović, Filip; Velić, Josipa

    2014-06-01

    We present two examples of describing low permeability Neogene clastic lithofacies to outline unconventional hydrocarbon lithofacies. Both examples were selected from the Drava Depression, the largest macrostructure of the Pannonian Basin System located in Croatia. The first example is the Beničanci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics that consists mostly of breccia. The definition of low permeability lithofacies is related to the margins of the existing reservoir, where the reservoir lithology changed into a transitional one, which is mainly depicted by the marlitic sandstones. However, calculation of the POS (probability of success of new hydrocarbons) shows critical geological categories where probabilities are lower than those in the viable reservoir with proven reserves. Potential new hydrocarbon volumes are located in the structural margins, along the oil-water contact, with a POS of 9.375%. These potential reserves in those areas can be classified as probable. A second example was the Cremušina Structure, where a hydrocarbon reservoir was not proven, but where the entire structure has been transferred onto regional migration pathways. The Lower Pontian lithology is described from well logs as fine-grained sandstones with large sections of silty or marly clastics. As a result, the average porosity is low for conventional reservoir classification (10.57%). However, it is still an interesting case for consideration as a potentially unconventional reservoir, such as the "tight" sandstones.

  13. Clastic depositional styles and reservoir potential of Mediterranean basins

    SciTech Connect

    Bouma, A.H. )

    1990-05-01

    A variety of tectonic styles and activities throughout the late Mesozoic and younger epochs influenced sediment transport to the Mediterranean basins and, consequently, the approach needed to finding reservoir-type clastics. The style of the present-day basins varies from west to east, with large basinal depressions and continental rises in the western province, more elongate shapes in the central area, and numerous small basins and trenches in the eastern Mediterranean. In general terms, all these basins contain a similar fill: a deep-water sequence older than late Miocene, overlain by upper Miocene evaporites, and topped by Pliocene-Quaternary clastics. The exact type of fill depends on several factors, including proximity to the sediment source, climatic conditions, subsidence and tectonic activity, and tectono-eustatic or glacio-eustatic oscillations. Investigations on many of the clastic reservoirs in Mediterranean basins should emphasize submarine fans. The modern Mediterranean Sea contains several mid-sized fans (Rhone, Ebro, Valencia, and Nile fans) and many small ones (e.g., Crati Fan). There are several well-studied Tertiary subsurface and outcropping turbidite systems. The concept of deep-water marine sands, and many of the initial studies, began with some of the now classic outcrops in Italy, France, and Spain. A well-integrated study of both modern and ancient turbidite series is needed to construct basic exploration models for the Mediterranean region. 9 figs., 1 tab.

  14. Identification and Assessment of Potential Water Quality Impact Factors for Drinking-Water Reservoirs

    PubMed Central

    Gu, Qing; Deng, Jinsong; Wang, Ke; Lin, Yi; Li, Jun; Gan, Muye; Ma, Ligang; Hong, Yang

    2014-01-01

    Various reservoirs have been serving as the most important drinking water sources in Zhejiang Province, China, due to the uneven distribution of precipitation and severe river pollution. Unfortunately, rapid urbanization and industrialization have been continuously challenging the water quality of the drinking-water reservoirs. The identification and assessment of potential impacts is indispensable in water resource management and protection. This study investigates the drinking water reservoirs in Zhejiang Province to better understand the potential impact on water quality. Altogether seventy-three typical drinking reservoirs in Zhejiang Province encompassing various water storage levels were selected and evaluated. Using fifty-two reservoirs as training samples, the classification and regression tree (CART) method and sixteen comprehensive variables, including six sub-sets (land use, population, socio-economy, geographical features, inherent characteristics, and climate), were adopted to establish a decision-making model for identifying and assessing their potential impacts on drinking-water quality. The water quality class of the remaining twenty-one reservoirs was then predicted and tested based on the decision-making model, resulting in a water quality class attribution accuracy of 81.0%. Based on the decision rules and quantitative importance of the independent variables, industrial emissions was identified as the most important factor influencing the water quality of reservoirs; land use and human habitation also had a substantial impact on water quality. The results of this study provide insights into the factors impacting the water quality of reservoirs as well as basic information for protecting reservoir water resources. PMID:24919129

  15. Treponemes Detected in Digital Dermatitis Lesions in Brazilian Dairy Cattle and Possible Host Reservoirs of Infection

    PubMed Central

    Nascimento, Ligia Valéria; Mauerwerk, Marlise Teresinha; dos Santos, Cibelli Lopes; de Barros Filho, Ivan Roque; Birgel Júnior, Eduardo Harry; Madeira, Humberto Maciel França

    2015-01-01

    The main pathogenic treponemes causing bovine digital dermatitis were identified from 17 infected herds in southern Brazil for the first time in this study using PCR. We did not find a relationship between treponeme phylogroup composition and clinical classification. Treponema phagedenis was present in all lesions. Rumen fluid was implicated as a reservoir location for these pathogens. PMID:25788552

  16. Development of a molecular tool for the identification of Leishmania reservoir hosts by blood meal analysis in the insect vectors.

    PubMed

    Haouas, Najoua; Pesson, Bernard; Boudabous, Raja; Dedet, Jean-Pierre; Babba, Hamouda; Ravel, Christophe

    2007-12-01

    The transmission of parasites of the genus Leishmania involves a large diversity of mammalian reservoir hosts. However, many of these are yet to be identified, mainly in isolated biotopes such as the Amazonian rain forest. Furthermore, the trophic preferences of insect vectors have major epidemiologic implications. In this study, we developed a molecular tool for the identification of blood meals of phlebotomine sand flies. This assay is based on specific amplification and sequencing of the blood meal-derived single copy prepronociceptin (PNOC) gene, which is used as a target in phylogenetic studies of mammals. Sand flies were identified simultaneously with the blood-meal identification, using molecular analysis of a ribosomal locus. After a systematic assessment of the sensitivity and specificity of polymerase chain reaction amplification of the PNOC gene using human fed sand flies, the assay was tested on wild-caught sand flies. This work has important implications for the discovery of new Leishmania reservoir hosts and for a better understanding of complex parasite life cycles. PMID:18165521

  17. Economic potential and optimum steamflood strategies for trough reservoirs of San Joaquin Valley, California

    SciTech Connect

    Hong, K.C.; Use, D.J.

    1995-12-31

    Many trough reservoirs in the Western San Joaquin Valley, California, remain undeveloped because reserve bases are relatively small and occur in areas where thermal recovery activities have been low. Reservoir models with different configurations and reserve bases were used to compare the economic potential of these reservoirs and to develop guidelines for selecting reservoirs that can be economically exploited. The models were also used for determining the optimum steamflood strategies for the selected reservoirs. The study showed that, for a trough reservoir to be an economical prospect, it should contain a minimum oil-in-place of 300 MSTB per pattern length along the trough between the synclinal axis and the gas-oil contact. Optimum steamflood strategy for such reservoirs includes: (1) placing the injector away from the synclinal axis and gas-oil contact, (2) having a row of producers updip from the injector and another near the synclinal axis, (3) starting the steamflood with an intermediate rate and high quality of steam, and (4) shutting-in steam injection after 5.5 years of continuous injection at a constant rate. This strategy can result in an annual rate of return of 20%.

  18. Host feeding patterns of established and potential mosquito vectors of West Nile virus in the eastern United States.

    PubMed

    Apperson, Charles S; Hassan, Hassan K; Harrison, Bruce A; Savage, Harry M; Aspen, Stephen E; Farajollahi, Ary; Crans, Wayne; Daniels, Thomas J; Falco, Richard C; Benedict, Mark; Anderson, Michael; McMillen, Larry; Unnasch, Thomas R

    2004-01-01

    An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile virus. Mammalophilic mosquito species in New Jersey and New York fed primarily upon white-tailed deer, while those from Memphis, Tennessee, fed mainly upon domestic dogs. A total of 24 different avian host species were detected among the avian-derived blood meals. American Robin, Northern Cardinal, Northern Mockingbird, Tufted Titmouse, and Brown-headed Cowbird were common avian hosts, while blood meals derived from the American Crow were relatively rare. Although the majority of common host species were potentially among the most abundant birds at each location, the proportion of blood meals from the most commonly fed upon avian species was greater than was predicted based upon the likely abundance of these species alone. These findings suggest that vector species for West Nile virus may preferentially feed upon certain avian hosts. PMID:15018775

  19. Massive stars formed in atomic hydrogen reservoirs: H I observations of gamma-ray burst host galaxies

    NASA Astrophysics Data System (ADS)

    Michałowski, M. J.; Gentile, G.; Hjorth, J.; Krumholz, M. R.; Tanvir, N. R.; Kamphuis, P.; Burlon, D.; Baes, M.; Basa, S.; Berta, S.; Castro Cerón, J. M.; Crosby, D.; D'Elia, V.; Elliott, J.; Greiner, J.; Hunt, L. K.; Klose, S.; Koprowski, M. P.; Le Floc'h, E.; Malesani, D.; Murphy, T.; Nicuesa Guelbenzu, A.; Palazzi, E.; Rasmussen, J.; Rossi, A.; Savaglio, S.; Schady, P.; Sollerman, J.; de Ugarte Postigo, A.; Watson, D.; van der Werf, P.; Vergani, S. D.; Xu, D.

    2015-10-01

    Long gamma-ray bursts (GRBs), among the most energetic events in the Universe, are explosions of massive and short-lived stars, so they pinpoint locations of recent star formation. However, several GRB host galaxies have recently been found to be deficient in molecular gas (H2), believed to be the fuel of star formation. Moreover, optical spectroscopy of GRB afterglows implies that the molecular phase constitutes only a small fraction of the gas along the GRB line of sight. Here we report the first ever 21 cm line observations of GRB host galaxies, using the AustraliaTelescope Compact Array, implying high levels of atomic hydrogen (H i), which suggests that the connection between atomic gas and star formation is stronger than previously thought. In this case, it is possible that star formation is directly fuelled by atomic gas (or that the H i-to-H2 conversion is very efficient, which rapidly exhaust molecular gas), as has been theoretically shown to be possible. This can happen in low-metallicity gas near the onset of star formation because cooling of gas (necessary for star formation) is faster than the H i-to-H2 conversion. Indeed, large atomic gas reservoirs, together with low molecular gas masses, stellar, and dust masses are consistent with GRB hosts being preferentially galaxies which have very recently started a star formation episode after accreting metal-poor gas from the intergalactic medium. This provides a natural route for forming GRBs in low-metallicity environments. The gas inflow scenario is also consistent with the existence of the companion H I object with no optical counterpart ~19 kpc from the GRB 060505 host, and with the fact that the H I centroids of the GRB 980425 and 060505 hosts do not coincide with optical centres of these galaxies, but are located close to the GRB positions.

  20. Inverse modelling of the reversely magnetized, shallow plumbing system hosting oil reservoirs of the Auca Mahuida volcano (Payeina retroarc, Neuquén Basin, Argentina)

    NASA Astrophysics Data System (ADS)

    Paine, John; De Ritis, Riccardo; Ventura, Guido; Longo, Mariana; Ravat, Dhananjay; Speranza, Fabio; Chiappini, Massimo

    2016-02-01

    The Auca Mahuida volcano (2.03-0.88 Ma) located east of the Andean thrust front in the Neuquén basin (Argentina) hosts an oil system of thermogenic origin and is affected by the NW-SE striking-faults. Intrusive bodies and the underlying Jurassic sediments constitute the reservoir rocks. Aeromagnetic data collected in the Auca Mahuida area detected multiple dipolar magnetic anomalies, many of which have reverse polarity. Palaeomagnetic measurements on rock samples collected in the field together with available age determinations indicate that the reversely magnetized sources were mainly emplaced during the Matuyama reverse polarity chron while the normal polarity sources were emplaced during the Olduvai and/or Jaramillo subchrons. The location and geometry of the intrusive bodies is poorly known and the customary magnetic inversion is rendered difficult because of multiple natural remanent magnetization directions. To address these difficulties, a voxel inversion was applied to model the vector residual magnetic intensity (VRMI) transformation of the observed total magnetic intensity data. The modelling showed a 1.5 km deep, subcircular ring-shaped intrusion below the summit of the volcano and a series of NW-SE elongated, fault-controlled intrusive bodies to depths up to 3-4 km. Our results show that magnetic data and VRMI modelling help resolve the geometry of the shallow plumbing system of volcanoes with remanently magnetized sources, and estimate the depth and geometry of potential oil reservoirs in volcanic areas.

  1. Evaluation of Gas Production Potential of Hydrate Deposits in Alaska North Slope using Reservoir Simulations

    NASA Astrophysics Data System (ADS)

    Nandanwar, M.; Anderson, B. J.

    2015-12-01

    Over the past few decades, the recognition of the importance of gas hydrates as a potential energy resource has led to more and more exploration of gas hydrate as unconventional source of energy. In 2002, U.S. Geological Survey (USGS) started an assessment to conduct a geology-based analysis of the occurrences of gas hydrates within northern Alaska. As a result of this assessment, many potential gas hydrate prospects were identified in the eastern National Petroleum Reserve Alaska (NPRA) region of Alaska North Slope (ANS) with total gas in-place of about 2 trillion cubic feet. In absence of any field test, reservoir simulation is a powerful tool to predict the behavior of the hydrate reservoir and the amount of gas that can be technically recovered using best suitable gas recovery technique. This work focuses on the advanced evaluation of the gas production potential of hydrate accumulation in Sunlight Peak - one of the promising hydrate fields in eastern NPRA region using reservoir simulations approach, as a part of the USGS gas hydrate development Life Cycle Assessment program. The main objective of this work is to develop a field scale reservoir model that fully describes the production design and the response of hydrate field. Due to the insufficient data available for this field, the distribution of the reservoir properties (such as porosity, permeability and hydrate saturation) are approximated by correlating the data from Mount Elbert hydrate field to obtain a fully heterogeneous 3D reservoir model. CMG STARS is used as a simulation tool to model multiphase, multicomponent fluid flow and heat transfer in which an equilibrium model of hydrate dissociation was used. Production of the gas from the reservoir is carried out for a period of 30 years using depressurization gas recovery technique. The results in terms of gas and water rate profiles are obtained and the response of the reservoir to pressure and temperature changes due to depressurization and hydrate

  2. A light carbon reservoir recorded in zircon-hosted diamond from the Jack Hills.

    PubMed

    Nemchin, Alexander A; Whitehouse, Martin J; Menneken, Martina; Geisler, Thorsten; Pidgeon, Robert T; Wilde, Simon A

    2008-07-01

    The recent discovery of diamond-graphite inclusions in the Earth's oldest zircon grains (formed up to 4,252 Myr ago) from the Jack Hills metasediments in Western Australia provides a unique opportunity to investigate Earth's earliest known carbon reservoir. Here we report ion microprobe analyses of the carbon isotope composition of these diamond-graphite inclusions. The observed delta(13)C(PDB) values (expressed using the PeeDee Belemnite standard) range between -5 per mil and -58 per mil with a median of -31 per mil. This extends beyond typical mantle values of around -6 per mil to values observed in metamorphic and some eclogitic diamonds that are interpreted to reflect deep subduction of low-delta(13)C(PDB) biogenic surface carbon. Low delta(13)C(PDB) values may also be produced by inorganic chemical reactions, and therefore are not unambiguous evidence for life on Earth as early as 4,250 Myr ago. Regardless, our results suggest that a low-delta(13)C(PDB) reservoir may have existed on the early Earth. PMID:18596808

  3. Infectiousness of Sylvatic and Synanthropic Small Rodents Implicates a Multi-host Reservoir of Leishmania (Viannia) braziliensis

    PubMed Central

    F. Brito, Maria E.; Carvalho, Francisco G.; Carvalho, Ana Waléria S.; Soares, Fábia; Carvalho, Silvia M.; Costa, Pietra L.; Zampieri, Ricardo; Floeter-Winter, Lucile M.; Shaw, Jeffrey J.; Brandão-Filho, Sinval P.

    2015-01-01

    Background The possibility that a multi-host wildlife reservoir is responsible for maintaining transmission of Leishmania (Viannia) braziliensis causing human cutaneous and mucocutaneous leishmaniasis is tested by comparative analysis of infection progression and infectiousness to sandflies in rodent host species previously shown to have high natural infection prevalences in both sylvatic or/and peridomestic habitats in close proximity to humans in northeast Brazil. Methods The clinical and parasitological outcomes, and infectiousness to sandflies, were observed in 54 colonized animals of three species (18 Necromys lasiurus, 18 Nectomys squamipes and 18 Rattus rattus) experimentally infected with high (5.5×106/ml) or low (2.8×105/ml) dose L. (V.) braziliensis (MBOL/BR/2000/CPqAM95) inoculum. Clinical signs of infection were monitored daily. Whole animal xenodiagnoses were performed 6 months post inoculation using Lutzomyia longipalpis originating from flies caught in Passira, Pernambuco, after this parasite evaluation was performed at necropsy. Heterogeneities in Leishmania parasite loads were measured by quantitative PCR in ear skin, liver and spleen tissues. Results All three rodent species proved to establish infection characterized by short-term self-resolving skin lesions, located on ears and tail but not on footpads (one site of inoculation), and variable parasite loads detected in all three tissues with maximum burdens of 8.1×103 (skin), 2.8×103 (spleen), and 8.9×102 (liver). All three host species, 18/18 N. lasiurus, 10/18 N. squamipes and 6/18 R. rattus, also proved infectious to sandflies in cross-sectional study. R. rattus supported significantly lower tissue parasite loads compared to those in N. lasiurus and N. squamipes, and N. lasiurus appeared to be more infectious, on average, than either N. squamipes or R. rattus. Conclusions A multi-host reservoir of cutaneous leishmaniasis is indicated in this region of Brazil, though with apparent

  4. Sensitivity of Lyme Borreliosis Spirochetes to Serum Complement of Regular Zoo Animals: Potential Reservoir Competence of Some Exotic Vertebrates.

    PubMed

    Ticha, Lucie; Golovchenko, Maryna; Oliver, James H; Grubhoffer, Libor; Rudenko, Nataliia

    2016-01-01

    Reaction of vertebrate serum complement with different Borrelia burgdorferi sensu lato species is used as a basis in determining reservoir hosts among domesticated and wild animals. Borrelia burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii were tested for their sensitivity to sera of exotic vertebrate species housed in five zoos located in the Czech Republic. We confirmed that different Borrelia species have different sensitivity to host serum. We found that tolerance to Borrelia infection possessed by hosts might differ among individuals of the same genera or species and is not affected by host age or sex. Of all zoo animals included in our study, carnivores demonstrated the highest apparent reservoir competency for Lyme borreliosis spirochetes. We showed that selected exotic ungulate species are tolerant to Borrelia infection. For the first time we showed the high tolerance of Siamese crocodile to Borrelia as compared to the other studied reptile species. While exotic vertebrates present a limited risk to the European human population as reservoirs for the causative agents of Lyme borreliosis, cases of incidental spillover infection could lead to successful replication of the pathogens in a new host, changing the status of selected exotic species and their role in pathogen emergence or maintenance. The question if being tolerant to pathogen means to be a competent reservoir host still needs an answer, simply because the majority of exotic animals might never be exposed to spirochetes in their natural environment. PMID:26783940

  5. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    SciTech Connect

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  6. Potential Triassic and Jurassic CO2 Storage Reservoirs in the Skagerrak Area

    NASA Astrophysics Data System (ADS)

    Baig, I.; Aagaard, P.; Fawad, M.; Sassier, C.; Faleide, J. I.; Jahren, J.; Gabrielsen, R. H.; Nielsen, L. H.; Kristensen, L.; Bergmo, P. E. S.

    2012-04-01

    pseudo-well was generated about 50 km north of an existing well in Denmark with the objective to predict facies. A depositional model with sediments sourced from north was assumed. A 50% thickness erosion of highstand sandstones was assumed at each cycle when sea level fell during a low stand. The removed thickness was compensated by non-reservoir transgressive systems tracts sediments (possible aggrading floodplain or lagoonal sediments). As good reservoir porosities (~20%) were found in wells in the south, porosities towards north are expected to be higher due to shallower depth of burial. The sealing properties of transgressive shales overlying the low stand sandstones are also important in local trapping and lateral distribution of the injected CO2. Furthermore the intercalation of shaly layers and permeability heterogeneities developed in prograding sand systems may provide additional trapping capacity to the reservoir. This geologic model is one of the likely scenarios that favors Gassum Formation as a potential CO2 storage reservoir in Skagerrak area and warrant to evaluate the reservoir using other possible scenarios.

  7. Host Reticulocytes Provide Metabolic Reservoirs That Can Be Exploited by Malaria Parasites

    PubMed Central

    Srivastava, Anubhav; Creek, Darren J.; Evans, Krystal J.; De Souza, David; Schofield, Louis; Müller, Sylke; Barrett, Michael P.; McConville, Malcolm J.; Waters, Andrew P.

    2015-01-01

    Human malaria parasites proliferate in different erythroid cell types during infection. Whilst Plasmodium vivax exhibits a strong preference for immature reticulocytes, the more pathogenic P. falciparum primarily infects mature erythrocytes. In order to assess if these two cell types offer different growth conditions and relate them to parasite preference, we compared the metabolomes of human and rodent reticulocytes with those of their mature erythrocyte counterparts. Reticulocytes were found to have a more complex, enriched metabolic profile than mature erythrocytes and a higher level of metabolic overlap between reticulocyte resident parasite stages and their host cell. This redundancy was assessed by generating a panel of mutants of the rodent malaria parasite P. berghei with defects in intermediary carbon metabolism (ICM) and pyrimidine biosynthesis known to be important for P. falciparum growth and survival in vitro in mature erythrocytes. P. berghei ICM mutants (pbpepc-, phosphoenolpyruvate carboxylase and pbmdh-, malate dehydrogenase) multiplied in reticulocytes and committed to sexual development like wild type parasites. However, P. berghei pyrimidine biosynthesis mutants (pboprt-, orotate phosphoribosyltransferase and pbompdc-, orotidine 5′-monophosphate decarboxylase) were restricted to growth in the youngest forms of reticulocytes and had a severe slow growth phenotype in part resulting from reduced merozoite production. The pbpepc-, pboprt- and pbompdc- mutants retained virulence in mice implying that malaria parasites can partially salvage pyrimidines but failed to complete differentiation to various stages in mosquitoes. These findings suggest that species-specific differences in Plasmodium host cell tropism result in marked differences in the necessity for parasite intrinsic metabolism. These data have implications for drug design when targeting mature erythrocyte or reticulocyte resident parasites. PMID:26042734

  8. Isolation of Ehrlichia chaffeensis from wild white-tailed deer (Odocoileus virginianus) confirms their role as natural reservoir hosts.

    PubMed Central

    Lockhart, J M; Davidson, W R; Stallknecht, D E; Dawson, J E; Howerth, E W

    1997-01-01

    Field and experimental studies have implicated white-tailed deer (Odocoileus virginianus) as probable reservoir hosts for Ehrlichia chaffeensis, the causative agent of human monocytic ehrlichiosis, but natural infection in deer has not been confirmed through isolation of E. chaffeensis. Thirty-five white-tailed deer collected from three Amblyomma americanum-infested populations in Georgia were examined for evidence of E. chaffeensis infection by serologic, molecular, cell culture, and xenodiagnostic methods. Twenty-seven deer (77%) had E. chaffeensis-reactive indirect fluorescent-antibody assay titers of > or = 1:64; and the blood, spleens, or lymph nodes of seven (20%) deer were positive in a nested PCR assay with E. chaffeensis-specific primers. E. chaffeensis was isolated in DH82 cell cultures from the blood of five (14%) deer, including two deer that were PCR negative. Combination of culture and PCR results indicated that six (17%) deer were probably rickettsemic and that nine (26%) were probably infected. Restriction digestion of PCR products amplified from deer tissues and cell culture isolates resulted in a banding pattern consistent with the E. chaffeensis 16S rRNA gene sequence. The sequences of all PCR products from deer tissues or cell culture isolates were identical to the sequence of the Arkansas type strain of E. chaffeensis. Xenodiagnosis with C3H mice inoculated intraperitoneally with deer blood, spleen, or lymph node suspensions was unsuccessful. When viewed in the context of previous studies, these findings provide strong evidence that E. chaffeensis is maintained in nature primarily by a tick vector-vertebrate reservoir system consisting of lone star ticks and white-tailed deer. PMID:9196173

  9. Assessment of Folsom Lake response to historical and potential future climate scenarios. 2. Reservoir management

    NASA Astrophysics Data System (ADS)

    Yao, H.; Georgakakos, A.

    2001-08-01

    An integrated forecast-decision system for Folsom Lake (California) is developed and used to assess the sensitivity of reservoir performance to various forecast-management schemes under historical and future climate scenarios. The assessments are based on various combinations of inflow forecasting models, decision rules, and climate scenarios. The inflow forecasting options include operational forecasts, historical analog ensemble forecasts, hydrologic ensemble forecasts, GCM-conditioned hydrologic ensemble forecasts, and perfect forecasts. Reservoir management is based on either heuristic rule curves or a decision system which includes three coupled models pertinent to turbine load dispatching, short-range energy generation scheduling, and long/mid-range reservoir management. The climate scenarios are based on historical inflow realizations, potential inflow realizations generated by General Circulation Models assuming no CO 2 increase, and potential inflow realizations assuming 1% CO 2 annual increase. The study demonstrates that (1) reliable inflow forecasts and adaptive decision systems can substantially benefit reservoir performance and (2) dynamic operational procedures can be effective climate change coping strategies.

  10. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland

    PubMed Central

    Hanke, Dennis; Freuling, Conrad M.; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R.; Bøtner, Anette; Mettenleiter, Thomas C.; Beer, Martin; Rasmussen, Thomas B.; Müller, Thomas F.; Höper, Dirk

    2016-01-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1–4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I – 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure

  11. Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

    PubMed

    Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

    2016-07-01

    There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in

  12. Host pigments: potential facilitators of photosynthesis in coral symbioses.

    PubMed

    Dove, Sophie G; Lovell, Carli; Fine, Maoz; Deckenback, Jeffry; Hoegh-Guldberg, Ove; Iglesias-Prieto, Roberto; Anthony, Kenneth R N

    2008-11-01

    Reef-building corals occur as a range of colour morphs because of varying types and concentrations of pigments within the host tissues, but little is known about their physiological or ecological significance. Here, we examined whether specific host pigments act as an alternative mechanism for photoacclimation in the coral holobiont. We used the coral Montipora monasteriata (Forskål 1775) as a case study because it occurs in multiple colour morphs (tan, blue, brown, green and red) within varying light-habitat distributions. We demonstrated that two of the non-fluorescent host pigments are responsive to changes in external irradiance, with some host pigments up-regulating in response to elevated irradiance. This appeared to facilitate the retention of antennal chlorophyll by endosymbionts and hence, photosynthetic capacity. Specifically, net P(max) Chl a(-1) correlated strongly with the concentration of an orange-absorbing non-fluorescent pigment (CP-580). This had major implications for the energetics of bleached blue-pigmented (CP-580) colonies that maintained net P(max) cm(-2) by increasing P(max) Chl a(-1). The data suggested that blue morphs can bleach, decreasing their symbiont populations by an order of magnitude without compromising symbiont or coral health. PMID:18643952

  13. Potential of ambient noise techniques to monitor reservoir dynamics at the St. Gallen geothermal site

    NASA Astrophysics Data System (ADS)

    Obermann, A.; Larose, E. F.; Wiemer, S.

    2014-12-01

    In the last decade two large geothermal energy projects were launched in Switzerland (Basel 2006, St Gallen 2013). Both of them were stopped after the occurrence of strongly felt earthquakes (Ml3.4 and 3.5, respectively). This illustrates that one of the key challenges for the use of deep geothermal energy remains to control the risk of inducing felt and potentially hazardous seismic events during the development and operation of an underground heat exchangers. Current monitoring techniques of induced seismicity, e.g. traffic light systems, attempt to forecast seismic hazard during and after stimulation based on observed seismicity and hydraulic data. A limitation of these techniques is their focus on seismic processes. We demonstrate the potential of ambient seismic noise correlation techniques to monitor aseismic reservoir dynamics related to the 2013 geothermal project in St. Gallen. In St. Gallen, reservoir characterization tests lead to an unexpected leakage of methane gas into the well. Well-head pressure rose rapidly and operators decided to prevent a possible well blow-out with counter-pressure. The result was an immediate increase of induced seismicity with a maximum event of Ml3.5. While the reservoir characterization was not accompanied by any significant induced seismicity that could have given an indication for the ongoing processes in the reservoir, ambient noise cross-correlations reveal a significant aseismic perturbation in the system that can be clearly linked to the stimulation tests. These additional constraints may help to better understand reservoir dynamics. We also discuss the future role of noise correlation based techniques for monitoring/mitigation purposes.

  14. Swelling and osmotic flow in a potential host rock

    NASA Astrophysics Data System (ADS)

    Horseman, S. T.; Harrington, J. F.; Noy, D. J.

    material. When immersed in distilled water, the cube swelled preferentially in a direction normal to bedding. Swelling was accompanied by visible opening of cracks. Volumetric strains of the clayshale during the swelling test were of the same order of magnitude as those during permeability testing. The presence of dilated cracks could explain the low membrane efficiency, since the dissociated ions of the salt would be able to diffuse through the crack network relatively unimpeded by electrostatic interactions with the clay mineral surfaces. The high compressibility and low membrane efficiency revealed by these experiments may be a consequence of fabric damage during sampling and specimen preparation or may actually be representative of the rock characteristics within the engineering disturbed zone (EDZ) of the tunnel niches. It is entirely possible that undisturbed rock remote from the excavations displays significantly lower compressibility and higher membrane efficiency. Even though the clayshale membrane in these experiments is inefficient, the results clearly demonstrate that Opalinus Clay is capable of supporting an osmotic flow of water. This has important implications in the specification, operation and interpretation of borehole tests aimed at the hydrogeological characterisation of this potential host rock. In addition the osmotic coupling term modifies the effective diffusion coefficient which should be accounted for when undertaking safety assessments.

  15. Micro- and macro-scale petrophysical characterization of potential reservoir units from the Northern Israel

    NASA Astrophysics Data System (ADS)

    Haruzi, Peleg; Halisch, Matthias; Katsman, Regina; Waldmann, Nicolas

    2016-04-01

    Lower Cretaceous sandstone serves as hydrocarbon reservoir in some places over the world, and potentially in Hatira formation in the Golan Heights, northern Israel. The purpose of the current research is to characterize the petrophysical properties of these sandstone units. The study is carried out by two alternative methods: using conventional macroscopic lab measurements, and using CT-scanning, image processing and subsequent fluid mechanics simulations at a microscale, followed by upscaling to the conventional macroscopic rock parameters (porosity and permeability). Comparison between the upscaled and measured in the lab properties will be conducted. The best way to upscale the microscopic rock characteristics will be analyzed based the models suggested in the literature. Proper characterization of the potential reservoir will provide necessary analytical parameters for the future experimenting and modeling of the macroscopic fluid flow behavior in the Lower Cretaceous sandstone.

  16. New sylvatic hosts of Trypanosoma cruzi and their reservoir competence in the humid Chaco of Argentina: a longitudinal study.

    PubMed

    Orozco, M Marcela; Enriquez, Gustavo F; Alvarado-Otegui, Julián A; Cardinal, M Victoria; Schijman, Alejandro G; Kitron, Uriel; Gürtler, Ricardo E

    2013-05-01

    A four-year longitudinal study of the structure of sylvatic transmission cycles of Trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid Chaco in Argentina. Among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in Dasypus novemcinctus armadillos (57.7%) and Didelphis albiventris opossums (38.1%) than in Euphractus sexcinctus (20.0%), Tolypeutes matacus (12.5%), and Chaetophractus vellerosus (6.3%) armadillos. Trypanosoma cruzi was detected for the first time in Thylamys pusilla small opossums and in two unidentified small rodents. Infection was spatially aggregated only in armadillos. All Didelphis were infected with T. cruzi I and all armadillo species were infected with T. cruzi III, implying two distinct sylvatic cycles with no inputs from the domestic cycle. Dasypus armadillos and Didelphis opossums were much more infectious to vectors than other armadillos, small opossums, or rodents. PMID:23530075

  17. Infrastructure and mechanical properties of a fault zone in sandstone as an outcrop analogue of a potential geothermal reservoir

    NASA Astrophysics Data System (ADS)

    Bauer, J. F.; Meier, S.; Philipp, S. L.

    2013-12-01

    Due to high drilling costs of geothermal projects, it is economically sensible to assess the potential suitability of a reservoir prior to drilling. Fault zones are of particular importance, because they may enhance fluid flow, or be flow barriers, respectively, depending on their particular infrastructure. Outcrop analogue studies are useful to analyze the fault zone infrastructure and thereby increase the predictability of fluid flow behavior across fault zones in the corresponding deep reservoir. The main aims of the present study are to 1) analyze the infrastructure and the differences of fracture system parameters in fault zones and 2) determine the mechanical properties of the faulted rocks. We measure fracture frequencies as well as orientations, lengths and apertures and take representative rock samples for each facies to obtain Young's modulus, compressive and tensile strengths in the laboratory. Since fractures reduce the stiffnesses of in situ rock masses we use an inverse correlation of the number of discontinuities to calculate effective (in situ) Young's moduli to investigate the variation of mechanical properties in fault zones. In addition we determine the rebound hardness, which correlates with the compressive strength measured in the laboratory, with a 'Schmidt-Hammer' in the field because this allows detailed maps of mechanical property variations within fault zones. Here we present the first results for a fault zone in the Triassic Lower Bunter of the Upper Rhine Graben in France. The outcrop at Cleebourg exposes the damage zone of the footwall and a clear developed fault core of a NNW-SSE-striking normal fault. The approximately 15 m wide fault core consists of fault gouge, slip zones, deformation bands and host rock lenses. Intensive deformation close to the core led to the formation of a distal fault core, a 5 m wide zone with disturbed layering and high fracture frequency. The damage zone also contains more fractures than the host rock

  18. Host Defense Peptides from Asian Frogs as Potential Clinical Therapies

    PubMed Central

    Kumar, Vineeth T.V.; Holthausen, David; Jacob, Joshy; George, Sanil

    2015-01-01

    Host defense peptides (HDPs) are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs. PMID:27025618

  19. Host Selection of Potential West Nile Virus Vectors in Puerto Barrios, Guatemala, 2007

    PubMed Central

    Kading, Rebekah C.; Reiche, Ana Silvia Gonzalez; Morales-Betoulle, Maria Eugenia; Komar, Nicholas

    2013-01-01

    The selection of vertebrate hosts by Culex mosquitoes relative to West Nile virus (WNV) transmission in neotropical countries such as Guatemala is not described. This study determined the feeding patterns of Cx. quinquefasciatus and Cx. nigripalpus and estimated the relative contribution of two common and frequently infected wild bird species, Turdus grayi and Quiscalus mexicanus, to WNV transmission. Engorged mosquitoes were collected from rural and urban habitats after the dry and wet seasons in the Department of Izabal in 2007. Host selection by Cx. nigripalpus varied significantly between urban and rural habitats. Both Cx. quinquefasciatus and Cx. nigripalpus fed predominantly on chickens and other domestic animals. Blood meals from wild birds were rare, accounting for 1.1% of blood meals identified from Cx. quinquefasciatus and 6.5% of blood meals from Cx. nigripalpus. Transmission of WNV by these two mosquito species may be dampened by extensive feeding on reservoir-incompetent hosts. PMID:23208881

  20. Calcium Phosphate: A potential host for halide contaminated plutonium wastes.

    SciTech Connect

    Metcalfe, Brian L.; Donald, Ian W.; Fong, Shirley K.; Gerrard, Lee A.; Strachan, Denis M.; Scheele, Randall D.

    2009-07-06

    The presence of significant quantities of fluoride and chloride in four types of legacy wastes from plutonium pyrochemical reprocessing required the development of a new wasteform which could adequately immobilize the halides in addition to the Pu and Am. Using a simulant chloride-based waste (Type I waste) and Sm as the surrogate for the Pu3+ and Am3+ present in the waste, AWE developed a process which utilised Ca3(PO4)2 as the host material. The waste was successfully incorporated into two crystalline phases, chlorapatite, [Ca5(PO4)3Cl], and spodiosite, [Ca2(PO4)Cl]. Radioactive studies performed at PNNL with 239Pu and 241Am confirmed the process. A slightly modified version of the process in which CaHPO4 was used as the host was successful in immobilizing a more complex multi-cation oxide–based waste (Type II) which contained significant concentrations of Cl and F in addition to 239Pu and 241Am. This waste resulted in the formation of cation-doped whitlockite, Ca3-xMgx(PO4)2, β-calcium phosphate, β-Ca2P2O7 and chlor-fluorapatite rather than the chlorapatite and spodiosite formed with Type I waste.

  1. Wild boar (Sus scrofa) - reservoir host of Toxoplasma gondii, Neospora caninum and Anaplasma phagocytophilum in Slovakia.

    PubMed

    Reiterová, Katarína; Špilovská, Silvia; Blaňarová, Lucia; Derdáková, Markéta; Čobádiová, Andrea; Hisira, Vladimír

    2016-06-01

    In Central Europe the wild boar population is permanently growing and consequently Cf foodborne infections. In this study serological and molecular detection of Toxoplasma gondii and Neospora caninum in wild boars was evaluated. Moreover, same samples were screened for the presence and genetic variability of tick-borne bacterium Anaplasma phagocytophilum. Blood samples collected from 113 wild boars from Southern Slovakia were examined for antibodies to T. gondii by indirect and to N. caninum by competitive ELISA. The presence of parasitic DNA in blood samples was determined by standard or real time PCR techniques. Antibodies against T. gondii and N. caninum were detected in 45 (39.8%) and 38 (33.6%) animals, respectively. Females were more frequently infected for both pathogens than males. The high seropositivity against both coccidia indicates a permanent occurrence of these pathogens in the studied locality. T. gondii DNA was confirmed in five seropositive boars (4.4%) and N. caninum in 23 blood samples (20.4%). Three out of 23 N. caninum PCR positive animals did not show seropositivity. Three out of 113 blood samples of wild boars were positive for A. phagocytophilum (2.7%). The obtained A. phagocytophilum sequences were 100% identical with GenBankTM isolates from Slovak dog (KC985242); German horse (JF893938) or wild boar (EF143810) and red deer (EF143808) from Poland. Coinfections of T. gondii with N. caninum and N. caninum with A. phagocytophilum were detected in single cases. Results suggest a potential zoonotic risk of toxoplasmosis transmission to humans and the spread of neosporosis to farm animals. PMID:27078648

  2. New records with examples of potential host colonization events for hypopi (Acari: Hypoderatidae) from birds

    USGS Publications Warehouse

    Pence, Danny B.; Spalding, M.G.; Bergan, J.F.; Cole, R.A.

    1997-01-01

    New host, geographic records, or both are established for 14 species of hypoderatid deutonymphs from 14 species of birds in North America. Ten of these records are regarded as examples of a potential host colonization event where these hypopi have become established in hosts other than those with which they are normally associated. Herein, potential host colonization events by hypoderatid deutonymphs are regarded as more of an ecologically determined than physiologically specific phenomenon, often specifically related to sharing of nesting sites in the same rookeries by different host taxa. Neottialges ibisicola Young & Pence is placed as a junior synonym of Neottialges plegadicola Fain. The taxonomic status of Hypodectes propus from columbid versus ardeid hosts needs further study.

  3. Microclimate impacts survival and prevalence of Phytophthora ramorum in Umbellularia californica, a key reservoir host of sudden oak death in Northern California forests.

    PubMed

    DiLeo, Matthew V; Bostock, Richard M; Rizzo, David M

    2014-01-01

    Phytophthora ramorum, an invasive pathogen and the causal agent of Sudden Oak Death, has become established in mixed-evergreen and redwood forests in coastal northern California. While oak and tanoak mortality is the most visible indication of P. ramorum's presence, epidemics are largely driven by the presence of bay laurel (Umbellularia californica), a reservoir host that supports both prolific sporulation in the winter wet season and survival during the summer dry season. In order to better understand how over-summer survival of the pathogen contributes to variability in the severity of annual epidemics, we monitored the viability of P. ramorum leaf infections over three years along with coincident microclimate. The proportion of symptomatic bay laurel leaves that contained viable infections decreased during the first summer dry season and remained low for the following two years, likely due to the absence of conducive wet season weather during the study period. Over-summer survival of P. ramorum was positively correlated with high percent canopy cover, less negative bay leaf water potential and few days exceeding 30°C but was not significantly different between mixed-evergreen and redwood forest ecosystems. Decreased summer survival of P. ramorum in exposed locations and during unusually hot summers likely contributes to the observed spatiotemporal heterogeneity of P. ramorum epidemics. PMID:25098281

  4. The commensal infant gut meta-mobilome as a potential reservoir for persistent multidrug resistance integrons.

    PubMed

    Ravi, Anuradha; Avershina, Ekaterina; Foley, Steven L; Ludvigsen, Jane; Storrø, Ola; Øien, Torbjørn; Johnsen, Roar; McCartney, Anne L; L'Abée-Lund, Trine M; Rudi, Knut

    2015-01-01

    Despite the accumulating knowledge on the development and establishment of the gut microbiota, its role as a reservoir for multidrug resistance is not well understood. This study investigated the prevalence and persistence patterns of an integrase gene (int1), used as a proxy for integrons (which often carry multiple antimicrobial resistance genes), in the fecal microbiota of 147 mothers and their children sampled longitudinally from birth to 2 years. The study showed the int1 gene was detected in 15% of the study population, and apparently more persistent than the microbial community structure itself. We found int1 to be persistent throughout the first two years of life, as well as between mothers and their 2-year-old children. Metagenome sequencing revealed integrons in the gut meta-mobilome that were associated with plasmids and multidrug resistance. In conclusion, the persistent nature of integrons in the infant gut microbiota makes it a potential reservoir of mobile multidrug resistance. PMID:26507767

  5. The commensal infant gut meta-mobilome as a potential reservoir for persistent multidrug resistance integrons

    PubMed Central

    Ravi, Anuradha; Avershina, Ekaterina; Foley, Steven L.; Ludvigsen, Jane; Storrø, Ola; Øien, Torbjørn; Johnsen, Roar; McCartney, Anne L.; L’Abée-Lund, Trine M.; Rudi, Knut

    2015-01-01

    Despite the accumulating knowledge on the development and establishment of the gut microbiota, its role as a reservoir for multidrug resistance is not well understood. This study investigated the prevalence and persistence patterns of an integrase gene (int1), used as a proxy for integrons (which often carry multiple antimicrobial resistance genes), in the fecal microbiota of 147 mothers and their children sampled longitudinally from birth to 2 years. The study showed the int1 gene was detected in 15% of the study population, and apparently more persistent than the microbial community structure itself. We found int1 to be persistent throughout the first two years of life, as well as between mothers and their 2-year-old children. Metagenome sequencing revealed integrons in the gut meta-mobilome that were associated with plasmids and multidrug resistance. In conclusion, the persistent nature of integrons in the infant gut microbiota makes it a potential reservoir of mobile multidrug resistance. PMID:26507767

  6. A framework to gauge the epidemic potential of plant pathogens in environmental reservoirs: the example of kiwifruit canker.

    PubMed

    Bartoli, Claudia; Lamichhane, Jay Ram; Berge, Odile; Guilbaud, Caroline; Varvaro, Leonardo; Balestra, Giorgio M; Vinatzer, Boris A; Morris, Cindy E

    2015-02-01

    New economically important diseases on crops and forest trees emerge recurrently. An understanding of where new pathogenic lines come from and how they evolve is fundamental for the deployment of accurate surveillance methods. We used kiwifruit bacterial canker as a model to assess the importance of potential reservoirs of new pathogenic lineages. The current kiwifruit canker epidemic is at least the fourth outbreak of the disease on kiwifruit caused by Pseudomonas syringae in the mere 50 years in which this crop has been cultivated worldwide, with each outbreak being caused by different genetic lines of the bacterium. Here, we ask whether strains in natural (non-agricultural) environments could cause future epidemics of canker on kiwifruit. To answer this question, we evaluated the pathogenicity, endophytic colonization capacity and competitiveness on kiwifruit of P. syringae strains genetically similar to epidemic strains and originally isolated from aquatic and subalpine habitats. All environmental strains possessing an operon involved in the degradation of aromatic compounds via the catechol pathway grew endophytically and caused symptoms in kiwifruit vascular tissue. Environmental and epidemic strains showed a wide host range, revealing their potential as future pathogens of a variety of hosts. Environmental strains co-existed endophytically with CFBP 7286, an epidemic strain, and shared about 20 virulence genes, but were missing six virulence genes found in all epidemic strains. By identifying the specific gene content in genetic backgrounds similar to known epidemic strains, we developed criteria to assess the epidemic potential and to survey for such strains as a means of forecasting and managing disease emergence. PMID:24986268

  7. Efficacy of two rodenticides against Leishmania reservoir host rat (Psammomys obesus) in the rural area of Al-Ahsa Oasis, Saudi Arabia.

    PubMed

    Al-Mohammed, Hamdan I

    2010-12-01

    Zoonotic cutaneous leishmaniasis (ZCL) is a serious and increasing public health problem in many parts of Saudi Arabia. Rodent control operations are effective in destroying rodents and reducing the incidence of disease. This study tested the efficacy of zinc phosphide and fenacoum against the reservoir host Psammomys obesus rat. The results showed that both the rodenticides were significantly (P < 0.01) effective in reducing the number of active holes during one year of application. PMID:21268531

  8. Analysis of cathepsin and furin proteolytic enzymes involved in viral fusion protein activation in cells of the bat reservoir host.

    PubMed

    El Najjar, Farah; Lampe, Levi; Baker, Michelle L; Wang, Lin-Fa; Dutch, Rebecca Ellis

    2015-01-01

    Bats of different species play a major role in the emergence and transmission of highly pathogenic viruses including Ebola virus, SARS-like coronavirus and the henipaviruses. These viruses require proteolytic activation of surface envelope glycoproteins needed for entry, and cellular cathepsins have been shown to be involved in proteolysis of glycoproteins from these distinct virus families. Very little is currently known about the available proteases in bats. To determine whether the utilization of cathepsins by bat-borne viruses is related to the nature of proteases in their natural hosts, we examined proteolytic processing of several viral fusion proteins in cells derived from two fruit bat species, Pteropus alecto and Rousettus aegyptiacus. Our work shows that fruit bat cells have homologs of cathepsin and furin proteases capable of cleaving and activating both the cathepsin-dependent Hendra virus F and the furin-dependent parainfluenza virus 5 F proteins. Sequence analysis comparing Pteropus alecto furin and cathepsin L to proteases from other mammalian species showed a high degree of conservation; however significant amino acid variation occurs at the C-terminus of Pteropus alecto furin. Further analysis of furin-like proteases from fruit bats revealed that these proteases are catalytically active and resemble other mammalian furins in their response to a potent furin inhibitor. However, kinetic analysis suggests that differences may exist in the cellular localization of furin between different species. Collectively, these results indicate that the unusual role of cathepsin proteases in the life cycle of bat-borne viruses is not due to the lack of active furin-like proteases in these natural reservoir species; however, differences may exist between furin proteases present in fruit bats compared to furins in other mammalian species, and these differences may impact protease usage for viral glycoprotein processing. PMID:25706132

  9. Analysis of Cathepsin and Furin Proteolytic Enzymes Involved in Viral Fusion Protein Activation in Cells of the Bat Reservoir Host

    PubMed Central

    El Najjar, Farah; Lampe, Levi; Baker, Michelle L.; Wang, Lin-Fa; Dutch, Rebecca Ellis

    2015-01-01

    Bats of different species play a major role in the emergence and transmission of highly pathogenic viruses including Ebola virus, SARS-like coronavirus and the henipaviruses. These viruses require proteolytic activation of surface envelope glycoproteins needed for entry, and cellular cathepsins have been shown to be involved in proteolysis of glycoproteins from these distinct virus families. Very little is currently known about the available proteases in bats. To determine whether the utilization of cathepsins by bat-borne viruses is related to the nature of proteases in their natural hosts, we examined proteolytic processing of several viral fusion proteins in cells derived from two fruit bat species, Pteropus alecto and Rousettus aegyptiacus. Our work shows that fruit bat cells have homologs of cathepsin and furin proteases capable of cleaving and activating both the cathepsin-dependent Hendra virus F and the furin-dependent parainfluenza virus 5 F proteins. Sequence analysis comparing Pteropus alecto furin and cathepsin L to proteases from other mammalian species showed a high degree of conservation; however significant amino acid variation occurs at the C-terminus of Pteropus alecto furin. Further analysis of furin-like proteases from fruit bats revealed that these proteases are catalytically active and resemble other mammalian furins in their response to a potent furin inhibitor. However, kinetic analysis suggests that differences may exist in the cellular localization of furin between different species. Collectively, these results indicate that the unusual role of cathepsin proteases in the life cycle of bat-borne viruses is not due to the lack of active furin-like proteases in these natural reservoir species; however, differences may exist between furin proteases present in fruit bats compared to furins in other mammalian species, and these differences may impact protease usage for viral glycoprotein processing. PMID:25706132

  10. Remote identification of potential boll weevil host plants: Airborne multispectral detection of regrowth cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regrowth cotton plants can serve as potential hosts for boll weevils during and beyond the production season. Effective methods for timely areawide detection of these host plants are critically needed to expedite eradication in south Texas. We acquired airborne multispectral images of experimental...

  11. Evaluating Geothermal Potential in Germany by Numerical Reservoir Modeling of Engineered Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Jain, Charitra; Vogt, Christian; Clauser, Christoph

    2014-05-01

    We model hypothetical Engineered Geothermal System (EGS) reservoirs by solving coupled partial differential equations governing fluid flow and heat transport. Building on EGS's strengths of inherent modularity and storage capability, it is possible to implement multiple wells in the reservoir to extend the rock volume accessible for circulating water in order to increase the heat yield. By varying parameters like flow rates and well-separations in the subsurface, this study looks at their long-term impacts on the reservoir development. This approach allows us to experiment with different placements of the engineered fractures and propose several EGS layouts for achieving optimized heat extraction. Considering the available crystalline area and accounting for the competing land uses, this study evaluates the overall EGS potential and compares it with those of other used renewables in Germany. There is enough area to support 13450 EGS plants, each with six reversed-triplets (18 wells) and an average electric power of 35.3MWe. When operated at full capacity, these systems can collectively supply 4155TWh of electric energy in one year which would be roughly six times the electric energy produced in Germany in the year 2011. Engineered Geothermal Systems make a compelling case for contributing towards national power production in a future powered by a sustainable, decentralized energy system.

  12. ANALYSIS OF FAULT SEAL POTENTIAL FOR KNOX RESERVOIRS IN THE SOUTHERN ILLINOIS BASIN

    SciTech Connect

    Hickman, John; Leetaru, Hannes

    2014-09-30

    The presence of known faults near potential geologic CO2 sequestration sites significantly raises the uncertainty of having a sufficient seal to prevent leakage along the fault plane from the intended reservoir. In regions where relocating a large sequestration project a considerable distance away from any known faults is impractical, a detailed analysis of the sealing potential of any faults within the projected future injection plume must be performed. In order to estimate the sealing potential of faults within the Late Cambrian-Early Ordovician Knox Supergroup in the Illinois Basin, two well-based cross sections were produced across two different regional fault systems (Rough Creek Fault Zone in Kentucky, and the unnamed core fault of the LaSalle Anticlinorium in Illinois) to calculate subsurface stratigraphic juxtapositions across each fault zone. Using this stratigraphic and lithologic data, three different algorithms were used to calculate the sealing potential of a theoretical Knox reservoir at each section location. These results indicate a high probability for sealing within the Rough Creek Fault Zone, but a much lower probability for a continuous seal within the LaSalle Anticlinorium.

  13. The development of a host potential index and its postharvest application to the spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Novel methodology is presented for indexing the relative potential of hosts to function as resources. Results from studies examining host selection, utilization, and physiological development of the organism resourcing the host were combined and quantitatively related via a Host Potential Index (HPI...

  14. Gas reservoir potential of the Lower Ordovician Beekmantown Group, Quebec Lowlands, Canada

    SciTech Connect

    Dykstra, J.C.F.; Longman, M.W.

    1995-04-01

    The Beekmantown Group in the Quebec Lowlands was deposited as part of an extensive Early Ordovician coastal and shallow marine complex on the eastern margin of the North American craton. The Beekmantown is stratigraphically equivalent to the Beekmantown, Knox, Arbuckle, and Ellenburger rocks of the United States, and is subdivided into two formations: the sandstone-rich Theresa Formation and the overlying dolomite-rich Beauharnois. Dolomites of the Beekmantown provide an important exploration target in both the autochthon and the overlying thrust sheets of the Canadian and U.S. Appalachians. The reservoir potential of the autochthonous Beekmantown Group in the Quebec Lowlands can be determined from seismic data, well logs, cuttings, and petrographic analyses of depositional and diagenetic textures. Deposition of the Beekmantown occurred alongson the western passive margin of the Iapetus Ocean. By the Late Ordovician, the passive margin had been transformed into a foreland basin. Faulting locally positioned Upper Ordovician Utica source rocks against the Beekmantown and contributed to forming hydrocarbon reservoirs. The largest Beekmantown reservoir found to date is the St. Flavien field, with 7.75 bcf of original gas (methane) in place in fractured and possibly karst-influenced allochthonous dolomites within a thrust-fault anticline. Seven major depositional units can be distinguished in cuttings and correlated with wireline logs. Dolomites in the Beekmantown contain vuggy, moldic, intercrystalline, and fracture porosity. Early porosity formed at the top of the major depositional units in peritidal dolomites; however, much of this porosity was later filled by late-stage calcite cement after hydrocarbon migration. Thus, a key to finding gas reservoirs in the autochthonous Beekmantown is to define Ordovician poleostructures in which early and continuous entrapment of hydrocarbons prevented later cementation.

  15. Potential CO2 Sequestration in Oil Field Reservoirs: Baseline Mineralogy and Natural Diagenesis, Kern County, California

    NASA Astrophysics Data System (ADS)

    Horton, R. A.; Kaess, A. B.; Nguyen, D. T.; Caffee, S. E.; Olabise, O. E.

    2015-12-01

    Depleted oil fields have been suggested as potential sites for sequestration of CO2 generated from the burning of hydrocarbons. However, to be effective for removing CO2 from the atmosphere, the injected CO2 must remain within the reservoir. The role of atmospheric CO2 in rock weathering is well known and a growing body of experimental work indicates that under reservoir conditions supercritical CO2 also reacts with sedimentary rocks. In order to predict the behavior of injected CO2 in a given reservoir, detailed knowledge of the mineralogy is required. In addition, post-injection monitoring may include analyzing core samples to examine interactions between reservoir rocks and the CO2. Thus, documentation of the natural diagenetic processes within the reservoir is necessary so that changes caused by reactions with CO2 can be recognized. Kern County, California has been a major petroleum producing area for over a century and has three oil fields that have been identified as potential sites for CO2 sequestration. Two of these, Rio Bravo-Greeley and McKittrick, have no previously published mineralogic studies. Samples from these (and nearby Wasco) oil fields were studied using transmitted-light petrography and scanning electron microscopy. At Rio Bravo-Greeley-Wasco, Kreyenhagen (Eocene) and Vedder (Oligocene) sandstones are mainly arkosic arenites with only small amounts of volcanic rock fragments. Detrital feldspars exhibit wide compositional ranges (up to Or75Ab25 & Ab50An50). Diagenesis has greatly altered the rocks. There are significant amounts of relatively pure authigenic K-feldspar and albite. Small amounts of authigenic quartz, calcite, dolomite, ankerite, kaolinite, illite/smectite, chlorite, zeolite, and pyrite are present. Plagioclase has been preferentially dissolved, with andesine more susceptible than oligoclase. Al3+ has been exported from the sandstones. At McKittrick, Temblor sandstones (Oligocene-Miocene) contain up to 33% volcanic rock fragments

  16. Phylogeographic Structure of the White-Footed Mouse and the Deer Mouse, Two Lyme Disease Reservoir Hosts in Québec

    PubMed Central

    Fiset, Jessica; Tessier, Nathalie; Millien, Virginie; Lapointe, Francois-Joseph

    2015-01-01

    Modification of a species range is one of many consequences of climate change and is driving the emergence of Lyme disease in eastern Canada. The primary reservoir host of the bacteria responsible for Lyme disease, Borrelia burgdorferi, is the white-footed mouse (Peromyscus leucopus), whose range is rapidly shifting north into southern Québec. The deer mouse, P. maniculatus, is occurring over most Québec province and is a less competent host for B. burgdorferi. Here, we compared the phylogeographic structure of both Peromyscus species in Québec. Using a combination of multiple mitochondrial DNA markers and phylogeographic methods, we detected an ongoing and rapid expansion of P. leucopus, while P. maniculatus appears more stable. Haplotype and populations networks indicated that populations of P. maniculatus exhibit more genetic structure than P. leucopus across the study area. Furthermore, significant and consistent genetic divergences between populations of the two species on both sides of the St. Lawrence River suggest that distinct lineages of P. leucopus and P. maniculatus with different ancestral origins colonized Southern Québec following the Last Glacial Maximum. The phylogeographic structure of pathogens is expected to mirror the structure observed in their reservoir hosts. As different strains of Borrelia burgdorferi may be associated with different levels of pathogenicity and immune responses of their hosts, our results are helpful at better understanding the pattern of spread of Lyme disease in a zone of emergence, and associated risk for human populations. PMID:26633555

  17. Phylogeographic Structure of the White-Footed Mouse and the Deer Mouse, Two Lyme Disease Reservoir Hosts in Québec.

    PubMed

    Fiset, Jessica; Tessier, Nathalie; Millien, Virginie; Lapointe, Francois-Joseph

    2015-01-01

    Modification of a species range is one of many consequences of climate change and is driving the emergence of Lyme disease in eastern Canada. The primary reservoir host of the bacteria responsible for Lyme disease, Borrelia burgdorferi, is the white-footed mouse (Peromyscus leucopus), whose range is rapidly shifting north into southern Québec. The deer mouse, P. maniculatus, is occurring over most Québec province and is a less competent host for B. burgdorferi. Here, we compared the phylogeographic structure of both Peromyscus species in Québec. Using a combination of multiple mitochondrial DNA markers and phylogeographic methods, we detected an ongoing and rapid expansion of P. leucopus, while P. maniculatus appears more stable. Haplotype and populations networks indicated that populations of P. maniculatus exhibit more genetic structure than P. leucopus across the study area. Furthermore, significant and consistent genetic divergences between populations of the two species on both sides of the St. Lawrence River suggest that distinct lineages of P. leucopus and P. maniculatus with different ancestral origins colonized Southern Québec following the Last Glacial Maximum. The phylogeographic structure of pathogens is expected to mirror the structure observed in their reservoir hosts. As different strains of Borrelia burgdorferi may be associated with different levels of pathogenicity and immune responses of their hosts, our results are helpful at better understanding the pattern of spread of Lyme disease in a zone of emergence, and associated risk for human populations. PMID:26633555

  18. Potential Parasite Transmission in Multi-Host Networks Based on Parasite Sharing

    PubMed Central

    Pilosof, Shai; Morand, Serge; Krasnov, Boris R.; Nunn, Charles L.

    2015-01-01

    Epidemiological networks are commonly used to explore dynamics of parasite transmission among individuals in a population of a given host species. However, many parasites infect multiple host species, and thus multi-host networks may offer a better framework for investigating parasite dynamics. We investigated the factors that influence parasite sharing – and thus potential transmission pathways – among rodent hosts in Southeast Asia. We focused on differences between networks of a single host species and networks that involve multiple host species. In host-parasite networks, modularity (the extent to which the network is divided into subgroups of rodents that interact with similar parasites) was higher in the multi-species than in the single-species networks. This suggests that phylogeny affects patterns of parasite sharing, which was confirmed in analyses showing that it predicted affiliation of individuals to modules. We then constructed “potential transmission networks” based on the host-parasite networks, in which edges depict the similarity between a pair of individuals in the parasites they share. The centrality of individuals in these networks differed between multi- and single-species networks, with species identity and individual characteristics influencing their position in the networks. Simulations further revealed that parasite dynamics differed between multi- and single-species networks. We conclude that multi-host networks based on parasite sharing can provide new insights into the potential for transmission among hosts in an ecological community. In addition, the factors that determine the nature of parasite sharing (i.e. structure of the host-parasite network) may impact transmission patterns. PMID:25748947

  19. Exploring increase of flood attenuation potential of reservoirs through simple gates operations.

    NASA Astrophysics Data System (ADS)

    Masoero, A.; Claps, P.; Ganora, D.; Petaccia, A.

    2012-04-01

    Along with other flood risk mitigation measures, artificial flood storage has been considered as a mean to control flood peaks in mountainous basins, particularly as part of the flood management practices. Classical studies attain the evaluation of the 'natural' flood attenuation potential driven by the portion of volume available above the spillway crest level. These studies allow to reconstruct modified flood frequency curves in sections downstream as modified by this unconditioned type of attenuation. Less understood is the possibility to quantify the additional attenuation potential of reservoirs deriving by simple and standardized gates operations. Unconditioned gates opening in advance with respect to the incoming flood are the typical operations considered in this work. The study has been carried out using a system of 63 artificial reservoirs located in the Northwestern part of Italy, for which a comprehensive set of hydrological and hydraulic data has been collected with the help of the Italian Dams Authority (Registro Italiano Dighe, RID). The main aim of the study is to select the most interesting cases in which gates operation is able to consistently improve flood attenuation, and provide an overview of the effect that these dams exercise on the flood frequency curves of the river sections downstream. For what the 'natural' attenuation potential is concerned, an attenuation index named SFA (Synthetic Flood Attenuation) has been computed on all dams and subsequently used to modify the original frequency curve of the incoming floods. A recent regional statistical method for flood estimation has been used for this purpose. With the help of the same model and of additional information required to describe flood volumes, triangular and power-law synthetic flood hydrographs have been simulated. Gates operation is addressed to a preemptive drawdown, and is conceived as a fixed opening in defined conditions at the flood arrival. Consequently, the maximum

  20. 3D modelling of a dolomitized syn-sedimentary structure: an exhumed potential analogue of hydrocarbon reservoir.

    NASA Astrophysics Data System (ADS)

    Martinelli, Mattia; Franceschi, Marco; Massironi, Matteo; Bistacchi, Andrea; Di Cuia, Raffaele; Rizzi, Alessandro

    2016-04-01

    further increase the potential creation of potential hydrocarbon traps. These complex conditions are visible in a syn-sedimentary structure spectacularly exposed on the Monte Testo (Trentino, Italy). In this contribution, we present a 3D geo-model of this structure, obtained with SKUA-gOcad, based on 3D photogrammetric modelling, detailed geological mapping and structural analysis, porosity analysis carried out on representative sections, and geostatistical simulation of porosity on dolomitized bodies. Thanks to the 3D model we obtained: i) a thickness map of the Rotzo Formation that allow us to understand which faults were active during the deposition of the formation and which areas could have been more suitable for hydrocarbon accumulation; ii) a geometric and volumetric model of the structure that permitted us to study the porosity distribution and to define the potential volume of hydrocarbons that could be hosted by a similar structure. These results were eventually extrapolated to the entire platform, providing clues on the hydrocarbon potential of similar buried geologic bodies.

  1. Detecting fluid leakage of a reservoir dam based on streaming self-potential measurements

    NASA Astrophysics Data System (ADS)

    Song, Seo Young; Kim, Bitnarae; Nam, Myung Jin; Lim, Sung Keun

    2015-04-01

    Between many reservoir dams for agriculture in suburban area of South Korea, water leakage has been reported several times. The dam under consideration in this study, which is located in Gyeong-buk, in the south-east of the Korean Peninsula, was reported to have a large leakage at the right foot of downstream side of the reservoir dam. For the detection of the leakage, not only geological survey but also geophysical explorations have been made for precision safety diagnosis, since the leakage can lead to dam failure. Geophysical exploration includes both electrical-resistivity and self-potential surveys, while geological surveys water permeability test, standard penetration test, and sampling for undisturbed sample during the course of the drilling investigation. The geophysical explorations were made not only along the top of dam but also transverse the heel of dam. The leakage of water installations can change the known-heterogeneous structure of the dam body but also cause streaming spontaneous (self) potential (SP) anomaly, which can be detected by electrical resistivity and SP measurements, respectively. For the interpretation of streaming SP, we used trial-and-error method by comparing synthetic SP data with field SP data for model update. For the computation, we first invert the resistivity data to obtain the distorted resistivity structure of the dam levee then make three-dimensional electrical-resistivity modeling for the streaming potential distribution of the dam levee. Our simulation algorithm of streaming SP distribution based on the integrated finite difference scheme computes two-dimensional (2D) SP distribution based on the distribution of calculated flow velocities of fluid for a given permeability structure together with physical properties. This permeability is repeatedly updated based on error between synthetic and field SP data, until the synthetic data match the field data. Through this trial-and-error-based SP interpretation, we locate the

  2. Mini Review: Potential Applications of Non-host Resistance for Crop Improvement.

    PubMed

    Lee, Seonghee; Whitaker, Vance M; Hutton, Samuel F

    2016-01-01

    Plant breeding for disease resistance is crucial to sustain global crop production. For decades, plant breeders and researchers have extensively used host plant resistance genes (R-genes) to develop disease resistant cultivars. However, the general instability of R-genes in crop cultivars when challenged with diverse pathogen populations emphasizes the need for more stable means of resistance. Alternatively, non-host resistance is recognized as the most durable, broad-spectrum form of resistance against the majority of potential pathogens in plants and has gained great attention as an alternative target for managing resistance. While transgenic approaches have been utilized to transfer non-host resistance to host species, conventional breeding applications have been more elusive. Nevertheless, avenues for discovery and deployment of genetic loci for non-host resistance via hybridization are increasingly abundant, particularly when transferring genes among closely related species. In this mini review, we discuss current and developing applications of non-host resistance for crop improvement with a focus on the overlap between host and non-host mechanisms and the potential impacts of new technology. PMID:27462329

  3. [Evaluation and consideration of BRM-BRM and HDP (host defense potentiators)].

    PubMed

    Chihara, G

    1988-04-01

    It should first be stressed that the term BRM is wrong and unscientific, since this would include potassium cyanide or cancer chemotherapeutics in the strict sense of the term. Therefore, in this article we discuss the evaluation of Host Defence Potentiators (HDP). IL-2 or TNF should not be included as HDP because their action is local and not selective to cancer cells, similar to the case of cancer chemotherapeutics. IL-2 is not useful without the presence of IL-2-responsive cells in the host. The most important facet of the action of HDP is to increase the response of the host to cytokines or other bioactive substances according to the degree of maturation, differentiation or proliferation of responsive cells in the host defence mechanism. Lentinan appears to represent a unique class of HDP, markedly potentiating host resistance to cancer and bacterial, viral and parasitic infections, and shows prominent antitumor activity in syngeneic and autochthonous hosts, suppressing chemical and viral oncogenesis. The most important target of HDP is complete prevention of recurrence after "curative" surgery fundamentally through growth inhibition and regression of a small number of autochthonous tumor cells scattered in the host. Considering the excellent end-point results for phase III advanced and recurrent gastrointestinal and breast cancer, lentinan seems to be the most hopeful drug against cancer recurrence. The development of various new types of MDP mediating host homeostasis in the immune, endocrine and nervous systems and nutritional states is expected. PMID:3382231

  4. Mini Review: Potential Applications of Non-host Resistance for Crop Improvement

    PubMed Central

    Lee, Seonghee; Whitaker, Vance M.; Hutton, Samuel F.

    2016-01-01

    Plant breeding for disease resistance is crucial to sustain global crop production. For decades, plant breeders and researchers have extensively used host plant resistance genes (R-genes) to develop disease resistant cultivars. However, the general instability of R-genes in crop cultivars when challenged with diverse pathogen populations emphasizes the need for more stable means of resistance. Alternatively, non-host resistance is recognized as the most durable, broad-spectrum form of resistance against the majority of potential pathogens in plants and has gained great attention as an alternative target for managing resistance. While transgenic approaches have been utilized to transfer non-host resistance to host species, conventional breeding applications have been more elusive. Nevertheless, avenues for discovery and deployment of genetic loci for non-host resistance via hybridization are increasingly abundant, particularly when transferring genes among closely related species. In this mini review, we discuss current and developing applications of non-host resistance for crop improvement with a focus on the overlap between host and non-host mechanisms and the potential impacts of new technology. PMID:27462329

  5. [Potential ecological risks assessment of heavy metals in the reservoir sediment of the western Haihe River basin].

    PubMed

    Cheng, Xian; Wang, Rui-lin; Wang, Jian-li; Sun, Ran-hao

    2015-05-01

    The reservoirs distributed in the western part of Haihe River basin play a key role in drinking water supply in the densely populated region. The potential ecological risk of heavy metals stored in the reservoir sediments has drawn more attention during recent decades. In this study, a total of 10 reservoirs in the western Haihe River basin were sampled. The sediment samples were assessed by the Hakanson potential ecological risk evaluation index. The sediments of upstream and downstream rivers were also sampled for comparative analysis with those of the reservoirs. The results indicated the concentration of Cd was significantly higher than the background value in this region, it was 1.67 times of the background value on average and the highest was 2.77 times. The concentration of Pb was higher than the background value for more than half of the reservoirs. The potential ecological risk was evaluated by the toxic coefficient. The ecological risk level was decreased in the order of Cd>As>Pb>Ni>Cu>Cr>Zn. The ecological risk of Cd in most reservoir sediments belonged to a moderate harm. Xidayang Reservior, which supplied the drinking water for Beijing and Baoding, had the highest level of Cd pollution. The ecological risk of Cd in the upstream and downstream rivers was significantly higher than that of the reservoirs. In addition, the ecological risks of Pb, Cu and Ni in the upstream rivers were also higher than the reservoirs. The difference of ecological risks of Zn and Cr was not significant between reservoirs and rivers. PMID:26571670

  6. Experimental infection studies demonstrating Atlantic salmon as a host and reservoir of viral hemorrhagic septicemia virus type IVa with insights into pathology and host immunity

    USGS Publications Warehouse

    Lovy, Jan; Piesik, P.; Hershberger, P.K.; Garver, K.A.

    2013-01-01

    In British Columbia, Canada (BC), aquaculture of finfish in ocean netpens has the potential for pathogen transmission between wild and farmed species due to the sharing of an aquatic environment. Viral hemorrhagic septicemia virus (VHSV) is enzootic in BC and causes serious disease in wild Pacific herring, Clupea pallasii, which often enter and remain in Atlantic salmon, Salmo salar, netpens. Isolation of VHSV from farmed Atlantic salmon has been previously documented, but the effects on the health of farmed salmon and the wild fish sharing the environment are unknown. To determine their susceptibility, Atlantic salmon were exposed to a pool of 9 isolates of VHSV obtained from farmed Atlantic salmon in BC by IP-injection or by waterborne exposure and cohabitation with diseased Pacific herring. Disease intensity was quantified by recording mortality, clinical signs, histopathological changes, cellular sites of viral replication, expression of interferon-related genes, and viral tissue titers. Disease ensued in Atlantic salmon after both VHSV exposure methods. Fish demonstrated gross disease signs including darkening of the dorsal skin, bilateral exophthalmia, light cutaneous hemorrhage, and lethargy. The virus replicated within endothelial cells causing endothelial cell necrosis and extensive hemorrhage in anterior kidney. Infected fish demonstrated a type I interferon response as seen by up-regulation of genes for IFNα, Mx, and ISG15. In a separate trial infected salmon transmitted the virus to sympatric Pacific herring. The results demonstrate that farmed Atlantic salmon can develop clinical VHS and virus can persist in the tissues for at least 10 weeks. Avoiding VHS epizootics in Atlantic salmon farms would limit the potential of VHS in farmed Atlantic salmon, the possibility for further host adaptation in this species, and virus spillback to sympatric wild fishes.

  7. Experimental infection studies demonstrating Atlantic salmon as a host and reservoir of viral hemorrhagic septicemia virus type IVa with insights into pathology and host immunity.

    PubMed

    Lovy, J; Piesik, P; Hershberger, P K; Garver, K A

    2013-09-27

    In British Columbia, Canada (BC), aquaculture of finfish in ocean netpens has the potential for pathogen transmission between wild and farmed species due to the sharing of an aquatic environment. Viral hemorrhagic septicemia virus (VHSV) is enzootic in BC and causes serious disease in wild Pacific herring, Clupea pallasii, which often enter and remain in Atlantic salmon, Salmo salar, netpens. Isolation of VHSV from farmed Atlantic salmon has been previously documented, but the effects on the health of farmed salmon and the wild fish sharing the environment are unknown. To determine their susceptibility, Atlantic salmon were exposed to a pool of 9 isolates of VHSV obtained from farmed Atlantic salmon in BC by IP-injection or by waterborne exposure and cohabitation with diseased Pacific herring. Disease intensity was quantified by recording mortality, clinical signs, histopathological changes, cellular sites of viral replication, expression of interferon-related genes, and viral tissue titers. Disease ensued in Atlantic salmon after both VHSV exposure methods. Fish demonstrated gross disease signs including darkening of the dorsal skin, bilateral exophthalmia, light cutaneous hemorrhage, and lethargy. The virus replicated within endothelial cells causing endothelial cell necrosis and extensive hemorrhage in anterior kidney. Infected fish demonstrated a type I interferon response as seen by up-regulation of genes for IFNα, Mx, and ISG15. In a separate trial infected salmon transmitted the virus to sympatric Pacific herring. The results demonstrate that farmed Atlantic salmon can develop clinical VHS and virus can persist in the tissues for at least 10 weeks. Avoiding VHS epizootics in Atlantic salmon farms would limit the potential of VHS in farmed Atlantic salmon, the possibility for further host adaptation in this species, and virus spillback to sympatric wild fishes. PMID:23838146

  8. The reservoir potential of the Zechstein-3 carbonate member (Platten), offshore Netherlands

    SciTech Connect

    Baird, A.; Kelly, J.; Symonds, R. )

    1993-09-01

    The Platten has been examined from 31 released and nonreleased wells, dominantly from northern P and Q quadrants, Dutch North Sea, and including a limited number of adjacent onshore wells. Wireline log interpretations have been allied with available core log, sidewall core, and ditch sample data. This has allowed a division into four broad facies associations: lower ramp, shoal shoreface, lagoonal, and the dominantly siliciclastic peritidal. Primary porosity is concentrated in ooid grainstones of the shoal/shoreface facies association. Diagenesis has also been examined. While the Platten has been broadly affected by early dolomitization, which generally occluded porosity, later diagenesis was more selective and had a significant control on porosity creation more selective and has a significant control on porosity creation as well as occlusion. Location of Platten reservoir potential is shown by facies association, diagenetic texture, and percentage porosity maps. The best reservoir conditions in the Platten exist where the shoal/shoreface facies association coincides with faults and with diagenesis associated with fluid movements through fractures. Low-temperature hydrothermal fluids are shown in this study to be the most important control on the hydrocarbon potential of the Platten in much of the P and Q quadrants.

  9. Potential evaluation of CO2 storage and enhanced oil recovery of tight oil reservoir in the Ordos Basin, China.

    PubMed

    Tian, Xiaofeng; Cheng, Linsong; Cao, Renyi; Zhang, Miaoyi; Guo, Qiang; Wang, Yimin; Zhang, Jian; Cui, Yu

    2015-07-01

    Carbon -di-oxide (CO2) is regarded as the most important greenhouse gas to accelerate climate change and ocean acidification. The Chinese government is seeking methods to reduce anthropogenic CO2 gas emission. CO2 capture and geological storage is one of the main methods. In addition, injecting CO2 is also an effective method to replenish formation energy in developing tight oil reservoirs. However, exiting methods to estimate CO2 storage capacity are all based on the material balance theory. This was absolutely correct for normal reservoirs. However, as natural fractures widely exist in tight oil reservoirs and majority of them are vertical ones, tight oil reservoirs are not close. Therefore, material balance theory is not adaptive. In the present study, a new method to calculate CO2 storage capacity is presented. The CO2 effective storage capacity, in this new method, consisted of free CO2, CO2 dissolved in oil and CO2 dissolved in water. Case studies of tight oil reservoir from Ordos Basin was conducted and it was found that due to far lower viscosity of CO2 and larger solubility in oil, CO2 could flow in tight oil reservoirs more easily. As a result, injecting CO2 in tight oil reservoirs could obviously enhance sweep efficiency by 24.5% and oil recovery efficiency by 7.5%. CO2 effective storage capacity of Chang 7 tight oil reservoir in Longdong area was 1.88 x 10(7) t. The Chang 7 tight oil reservoir in Ordos Basin was estimated to be 6.38 x 10(11) t. As tight oil reservoirs were widely distributed in Songliao Basin, Sichuan Basin and so on, geological storage capacity of CO2 in China is potential. PMID:26387353

  10. Genomic profiling of host responses to Lassa virus: therapeutic potential from primate to man

    PubMed Central

    Zapata, Juan C; Salvato, Maria S

    2015-01-01

    Lassa virus infection elicits distinctive changes in host gene expression and metabolism. We focus on changes in host gene expression that may be biomarkers that discriminate individual pathogens or may help to provide a prognosis for disease. In addition to assessing mRNA changes, functional studies are also needed to discriminate causes of disease from mechanisms of host resistance. Host responses that drive pathogenesis are likely to be targets for prevention or therapy. Host responses to Lassa or its related arenaviruses have been monitored in cell culture, in animal models of hemorrhagic fever, in Lassa-infected nonhuman primates and, to a limited extent, in infected human beings. Here, we describe results from those studies and discuss potential targets for reducing virus replication and mitigating disease. PMID:25844088

  11. Preliminary study of a potential CO2 reservoir area in Hungary

    NASA Astrophysics Data System (ADS)

    Sendula, Eszter; Király, Csilla; Szabó, Zsuzsanna; Falus, György; Szabó, Csaba; Kovács, István; Füri, Judit; Kónya, Péter; Páles, Mariann; Forray, Viktória

    2014-05-01

    Since the first international agreement in 1997 (the Kyoto Protocol) the reduction of greenhouse gas emission has a key role in the European Union's energy and climate change policy. Following the Directive 2009/31/EC we are experiencing a significant change in the Hungarian national activity. Since the harmonization procedure, which was completed in May 2012, the national regulation obligates the competent authority to collect and regularly update all geological complexes that are potential for CO2 geological storage. In Hungary the most abundant potential storage formations are mostly saline aquifers of the Great Hungarian Plain (SE-Hungary), with sandstone reservoir and clayey caprock. The Neogene basin of the Great Hungarian Plain was subsided and then filled by a prograding delta system from NW and NE during the Late Miocene, mostly in the Pannonian time. The most potential storage rock was formed as a fine-grained sandy turbidite interlayered by thin argillaceous beds in the deepest part of the basin. It has relatively high porosity, depth and more than 1000 m thickness. Providing a regional coverage for the sandy turbidite, a 400-500 m thick argillaceous succession was formed in the slope environment. The composition, thickness and low permeability is expected to make it a suitable, leakage-safe caprock of the storage system. This succession is underlain by argillaceous rocks that were formed in the basin, far from sediment input and overlain by interfingering siltstone, sandstone and claystone succession formed in delta and shoreline environments and in the alluvial plain. Core samples have been collected from the potential reservoir rock and its cap rock in the Great Hungarian Plain's succession. The water compositions of the studied depth were known from well-log database. Using the information, acquired from these archive documents, we have constructed input data for geochemical modeling in order to to study the effect of pCO2 injection in the potential

  12. Modeling Self-Potential Effects During Reservoir Stimulation in Enhanced Geothermal Systems.

    NASA Astrophysics Data System (ADS)

    Troiano, Antonio; Giulia Di Giuseppe, Maria; Monetti, Alessio; Patella, Domenico; Troise, Claudia; De Natale, Giuseppe

    2015-04-01

    Geothermal systems represent a large resource that can provide, with a reasonable investment, a very high and cost-effective power generating capacity. Considering also the very low environmental impact, their development represents, in the next decades, an enormous perspective. Despite its unquestionable potential, geothermal exploitation has long been perceived as limited, mainly because of the dependence from strict site-related conditions, mainly related to the reservoir rock's permeability and to the high thermal gradient, implying the presence of large amounts of hot fluids at reasonable depth. Many of such limitations can be overcome using Enhanced Geothermal Systems technology (EGS), where massive fluid injection is performed to increase the rock permeability by fracturing. This is a powerful method to exploit hot rocks with low natural permeability, otherwise not exploitable. Numerical procedures have already been presented in literature reproducing thermodynamic evolution and stress changes of systems where fluids are injected. However, stimulated fluid flow in geothermal reservoirs can produce also surface Self-Potential (SP) anomalies of several mV. A commonly accepted interpretation involves the activation of electrokinetic processes. Since the induced seismicity risk is generally correlated to fluid circulation stimulated in an area exceeding the well of several hundreds of meters, the wellbore pressure values can be totally uncorrelated to seismic hazard. However, SP anomalies, being generated from pressure gradients in the whole area where fluids flow, has an interesting potential as induced earthquake precursor. In this work, SP anomalies observed above the Soultz-sous-Forets (Alsace, France) geothermal reservoir while injecting cold water have been modeled, considering a source related to the fluid flow induced by the well stimulation process. In particular, the retrieved changes of pressure due to well stimulation in the EGS system have been used

  13. High prevalence of Opisthorchis viverrini infection in reservoir hosts in four districts of Khon Kaen Province, an opisthorchiasis endemic area of Thailand.

    PubMed

    Aunpromma, Surasit; Tangkawattana, Prasarn; Papirom, Pittaya; Kanjampa, Prapan; Tesana, Smarn; Sripa, Banchob; Tangkawattana, Sirikachorn

    2012-03-01

    Khon Kaen, a northeastern province of Thailand, has been considered as one of the human opisthorchiasis endemic areas with continuing high prevalence. Unsuccessful eradication of the disease is probably from the culture of eating raw and undercooked fish of local residence and the parasitic persistency in animal reservoir hosts, such as cats and dogs. In cooperation with the other human opisthorchiasis control programs in an endemic area of 29 villages in Ban Haet, Ban Phai, Chonnabot and Muncha Khiri Districts, Khon Kaen, this study investigated the prevalence of Opisthorchis viverrini infection using a formalin-ether sedimentation method as the gold standard, and hematology and blood chemistry of the reservoir hosts in this endemic area. The results showed that cats had much higher prevalence (76 of 214, 35.51%) than dogs (3 of 821, 0.37%). Hematology between the infected and uninfected cats was not different. Complete blood count and biochemistry reflected some altered hepatic functions. However, only severely infected cats showed apparent clinical signs, including lethargy, diarrhea, ocular and nasal discharges. Moreover, the ultrasonogram of infected cats with very high egg per gram (>1500 EPG) showed apparent thickening of the gall bladder wall with hyperechoicity of hepatic parenchyma. This study suggests that cat is the most important animal reservoir of human opisthorchiasis, especially in this endemic area. It is also interesting that villages with infection are mostly located in the vicinity of Chi River and two large water reservoirs (Lawa and Nong Kongkaew Lakes), but people without infection were away from Chi River, on the south of Kudkhow Lake. Further investigation on this particular geofactor is essential for effective opisthorchiasis control programs. PMID:21843654

  14. Seasonal distribution of potentially pathogenic Acanthamoeba species from drinking water reservoirs in Taiwan.

    PubMed

    Kao, Po-Min; Hsu, Bing-Mu; Hsu, Tsui-Kang; Liu, Jorn-Hon; Chang, Hsiang-Yu; Ji, Wen-Tsai; Tzeng, Kai-Jiun; Huang, Shih-Wei; Huang, Yu-Li

    2015-03-01

    In order to detect the presence/absence of Acanthamoeba along with geographical variations, water quality variations and seasonal change of Acanthamoeba in Taiwan was investigated by 18S ribosomal RNA (rRNA) gene TaqMan quantitative real-time PCR. Samples were collected quarterly at 19 drinking water reservoir sites from November 2012 to August 2013. Acanthamoeba was detected in 39.5 % (30/76) of the water sample, and the detection rate was 63.2 % (12/19) from samples collected in autumn. The average concentration of Acanthamoeba was 3.59 × 10(4) copies/L. For geographic distribution, the detection rate for Acanthamoeba at the northern region was higher than the central and southern regions in all seasons. Results of Spearman rank test revealed that heterotrophic plate count (HPC) had a negative correlation (R = -0.502), while dissolved oxygen (DO) had a positive correlation (R = 0.463) in summer. Significant differences were found only between the presence/absence of Acanthamoeba and HPC in summer (Mann-Whitney U test, P < 0.05). T2 and T4 genotypes of Acanthamoeba were identified, and T4 was the most commonly identified Acanthamoeba genotypes. The presence of Acanthamoeba in reservoirs presented a potential public health threat and should be further examined. PMID:25263419

  15. Western Greece unconventional hydrocarbon potential from oil shale and shale gas reservoirs

    NASA Astrophysics Data System (ADS)

    Karakitsios, Vasileios; Agiadi, Konstantina

    2013-04-01

    It is clear that we are gradually running out of new sedimentary basins to explore for conventional oil and gas and that the reserves of conventional oil, which can be produced cheaply, are limited. This is the reason why several major oil companies invest in what are often called unconventional hydrocarbons: mainly oil shales, heavy oil, tar sand and shale gas. In western Greece exist important oil and gas shale reservoirs which must be added to its hydrocarbon potential1,2. Regarding oil shales, Western Greece presents significant underground immature, or close to the early maturation stage, source rocks with black shale composition. These source rock oils may be produced by applying an in-situ conversion process (ICP). A modern technology, yet unproven at a commercial scale, is the thermally conductive in-situ conversion technology, developed by Shell3. Since most of western Greece source rocks are black shales with high organic content, those, which are immature or close to the maturity limit have sufficient thickness and are located below 1500 meters depth, may be converted artificially by in situ pyrolysis. In western Greece, there are several extensive areas with these characteristics, which may be subject of exploitation in the future2. Shale gas reservoirs in Western Greece are quite possibly present in all areas where shales occur below the ground-water level, with significant extent and organic matter content greater than 1%, and during their geological history, were found under conditions corresponding to the gas window (generally at depths over 5,000 to 6,000m). Western Greece contains argillaceous source rocks, found within the gas window, from which shale gas may be produced and consequently these rocks represent exploitable shale gas reservoirs. Considering the inevitable increase in crude oil prices, it is expected that at some point soon Western Greece shales will most probably be targeted. Exploration for conventional petroleum reservoirs

  16. Build-and-fill sequences: How subtle paleotopography affects 3-D heterogeneity of potential reservoir facies

    USGS Publications Warehouse

    McKirahan, J.R.; Goldstein, R.H.; Franseen, E.K.

    2005-01-01

    This study analyzes the three-dimensional variability of a 20-meter-thick section of Pennsylvanian (Missourian) strata over a 600 km2 area of northeastern Kansas, USA. It hypothesizes that sea-level changes interact with subtle variations in paleotopography to influence the heterogeneity of potential reservoir systems in mixed carbonate-silidclastic systems, commonly produdng build-and-fill sequences. For this analysis, ten lithofacies were identified: (1) phylloid algal boundstone-packstone, (2) skeletal wackestone-packstone, (3) peloidal, skeletal packstone, (4) sandy, skeletal grainstone-packstone, (5) oolite grainstone-packstone, (6) Osagia-brachiopod packstone, (7) fossiliferous siltstone, (8) lenticular bedded-laminated siltstone and fine sandstone, (9) organic-rich mudstone and coal, and (10) massive mudstone. Each facies can be related to depositional environment and base-level changes to develop a sequence stratigraphy consisting of three sequence boundaries and two flooding surfaces. Within this framework, eighteen localities are used to develop a threedimensional framework of the stratigraphy and paleotopography. The studied strata illustrate the model of "build-and-fill". In this example, phylloid algal mounds produce initial relief, and many of the later carbonate and silidclastic deposits are focused into subtle paleotopographic lows, responding to factors related to energy, source, and accommodation, eventually filling the paleotopography. After initial buildup of the phylloid algal mounds, marine and nonmarine siliciclastics, with characteristics of both deltaic lobes and valley fills, were focused into low areas between mounds. After a sea-level rise, oolitic carbonates formed on highs and phylloid algal facies accumulated in lows. A shift in the source direction of siliciclastics resulted from flooding or filling of preexisting paleotopographic lows. Fine-grained silidclastics were concentrated in paleotopographic low areas and resulted in clay

  17. Targeted pulmonary delivery of inducers of host macrophage autophagy as a potential host-directed chemotherapy of tuberculosis.

    PubMed

    Gupta, Anuradha; Misra, Amit; Deretic, Vojo

    2016-07-01

    One of the promising host-directed chemotherapeutic interventions in tuberculosis (TB) is based on inducing autophagy as an immune effector. Here we consider the strengths and weaknesses of potential autophagy-based pharmacological intervention. Using the existing drugs that induce autophagy is an option, but it has limitations given the broad role of autophagy in most cells, tissues, and organs. Thus, it may be desirable that the agent being used to modulate autophagy is applied in a targeted manner, e.g. delivered to affected tissues, with infected macrophages being an obvious choice. This review addresses the advantages and disadvantages of delivering drugs to induce autophagy in M. tuberculosis-infected macrophages. One option, already being tested in models, is to design particles for inhalation delivery to lung macrophages. The choice of drugs, drug release kinetics and intracellular residence times, non-target cell exposure and feasibility of use by patients is discussed. We term here this (still experimental) approach, of compartment-targeting, autophagy-based, host-directed therapy as "Track-II antituberculosis chemotherapy." PMID:26829287

  18. Evaluating Potential for Large Releases from CO2 StorageReservoirs: Analogs, Scenarios, and Modeling Needs

    SciTech Connect

    Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang,Chin-Fu; Karimjee, Anhar

    2005-09-19

    While the purpose of geologic storage of CO{sub 2} in deep saline formations is to trap greenhouse gases underground, the potential exists for CO{sub 2} to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO{sub 2} is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO{sub 2} were to occur at the land surface, especially where CO{sub 2} could accumulate. In this paper, we develop possible scenarios for large CO{sub 2} fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies.

  19. PCR detection and sequencing of parasite ITS-rDNA gene from reservoirs host of zoonotic cutaneous leishmaniasis in central Iran.

    PubMed

    Parvizi, Parviz; Moradi, Ghasem; Akbari, Ghasem; Farahmand, Mahin; Ready, Paul D; Piazak, Norair; Assmar, Mehdi; Amirkhani, Aref

    2008-11-01

    Leishmania major is the causative agent of zoonotic cutaneous leishmaniasis (ZCL) in which gerbils are the reservoir host. ZCL is of great public health importance in Iran. In the current investigation, nested polymerase chain reaction (PCR) protocols were used to amplify a region of the ribosomal RNA amplicon of Leishmania (ITS1-5.8S rRNA gene). The PCR assays detected L. major in three rodent species: Rhombomis opimus, Meriones lybicus and, for first time, Meriones persicus. L. major parasite was found in Natanz, Isfahan Province in the center of Iran in a focus of rural zoonotic cutaneous leishmaniasis. Four L. major infections were detected in R. opimus species, three in M. Lybicus, and two in M. persicus. All nine rodent infections of L. major were found to be the same haplotype based on the PCR detection and sequencing of parasite ITS-ribosomal DNA gene. In addition, also for the first time, the nested PCR assays detected Leishmania tropica only in one M. persicus. Allied to studies in country, the new findings mean that past conclusions about the reservoir of L. major in Iran must be treated with caution. Finding two Leishmania species in different rodent species as reservoir in Iran, therefore, careful molecular eco-epidemiological investigations will be an essential part of modeling the roles of different gerbil species in maintaining and spreading ZCL foci. PMID:18791741

  20. Free-living ciliates as potential reservoirs for eukaryotic parasites: occurrence of a trypanosomatid in the macronucleus of Euplotes encysticus

    PubMed Central

    2014-01-01

    Background Flagellates of the family Trypanosomatidae are obligate endoparasites, which can be found in various hosts. Several genera infect insects and occur as monoxenous parasites especially in representatives of Diptera and Hemiptera. These trypanosomatid flagellates probably share the worldwide distribution of their hosts, which are often infested by large numbers of endoparasites. Traditionally, their taxonomy was based on morphology, host origin, and life cycle. Here we report the characterization of a trypanosomatid infection detected in a protozoan, a ciliate collected from a polluted freshwater pond in a suburb of New Delhi (India). Methods Live observations and morphological studies applying light, fluorescence and transmission electron microscopy were conducted. Molecular analyses of host and parasite were performed and used for phylogenetic reconstructions and species (host) or genus level (parasite) identification. Results Although the morphological characteristics were not revealing, a high similarity of the trypanosomatids 18S rRNA gene sequence to Herpetomonas ztiplika and Herpetomonas trimorpha (Kinetoplastida, Trypanosomatidae), both parasites of biting midges (Culicoides kibunensis and Culicoides truncorum, respectively) allowed the assignment to this genus. The majority of the host population displayed a heavy infection that significantly affected the shape of the host macronucleus, which was the main site of parasite localization. In addition, the growth rate of host cultures, identified as Euplotes encysticus according to cell morphology and 18S rRNA gene sequence, was severely impacted by the infection. Conclusions The host-parasite system described here represents a recent example of free-living protists acting as environmental reservoirs for parasitic eukaryotic microorganisms. PMID:24774858

  1. Evaluating the impact of caprock and reservoir properties on potential risk of CO2 leakage after injection

    SciTech Connect

    Hou, Zhangshuan; Rockhold, Mark L.; Murray, Christopher J.

    2012-01-05

    Numerical models are essential tools for CO2 sequestration projects and should be included in the life cycle of a project. Common practice involves modeling the behavior of CO2 during and after injection using site-specific reservoir and caprock properties. Little has been done to systematically evaluate and compare the effects of a broad but realistic range of reservoir and caprock properties on potential CO2 leakage through caprock. Broad-based research addressing the impacts of caprock properties and their heterogeneity on seal permeation is absent. Efforts along this direction require obtaining information about the physically reasonable range of caprock and reservoir properties, effectively sampling the parameter space to fully explore the range of these properties, and performing flow and transport calculations using reliable numerical simulators. In this study, we identify the most important factors affecting CO2 leakage through intact caprock and try to understand the underlying mechanisms. We use caprock and reservoir properties from various field sites and literature data to identify the range of caprock thickness, permeability, and porosity that might occur. We use a quasi Monte Carlo sampling approach to ensure that the full range of caprock and seal properties is evaluated without bias. For each set of sampled properties, the migration of injected CO2 is simulated for up to 200 years using the water-salt-CO2 operational mode of the STOMP simulator. Preliminary results show that critical factors determining CO2 leakage rate through intact caprock are, in decreasing order of significance, the caprock thickness, caprock permeability, reservoir permeability, caprock porosity, and reservoir porosity. This study provides a function for prediction of potential CO2 leakage risk due to permeation of intact caprock, and identifies a range of acceptable seal thicknesses and permeability for sequestration projects. As a byproduct, the dependence of CO2 injectivity

  2. Host specificity in vascular epiphytes: a review of methodology, empirical evidence and potential mechanisms

    PubMed Central

    Wagner, Katrin; Mendieta-Leiva, Glenda; Zotz, Gerhard

    2015-01-01

    Information on the degree of host specificity is fundamental for an understanding of the ecology of structurally dependent plants such as vascular epiphytes. Starting with the seminal paper of A.F.W. Schimper on epiphyte ecology in the late 19th century over 200 publications have dealt with the issue of host specificity in vascular epiphytes. We review and critically discuss this extensive literature. The available evidence indicates that host ranges of vascular epiphytes are largely unrestricted while a certain host bias is ubiquitous. However, tree size and age and spatial autocorrelation of tree and epiphyte species have not been adequately considered in most statistical analyses. More refined null expectations and adequate replication are needed to allow more rigorous conclusions. Host specificity could be caused by a large number of tree traits (e.g. bark characteristics and architectural traits), which influence epiphyte performance. After reviewing the empirical evidence for their relevance, we conclude that future research should use a more comprehensive approach by determining the relative importance of various potential mechanisms acting locally and by testing several proposed hypotheses regarding the relative strength of host specificity in different habitats and among different groups of structurally dependent flora. PMID:25564514

  3. Refuge or Reservoir? The Potential Impacts of the Biofuel Crop Miscanthus x giganteus on a Major Pest of Maize

    PubMed Central

    Spencer, Joseph L.; Raghu, S.

    2009-01-01

    Background Interest in the cultivation of biomass crops like the C4 grass Miscanthus x giganteus (Miscanthus) is increasing as global demand for biofuel grows. In the US, Miscanthus is promoted as a crop well-suited to the Corn Belt where it could be cultivated on marginal land interposed with maize and soybean. Interactions (direct and indirect) of Miscanthus, maize, and the major Corn Belt pest of maize, the western corn rootworm, (Diabrotica virgifera virgifera LeConte, WCR) are unknown. Adding a perennial grass/biomass crop to this system is concerning since WCR is adapted to the continuous availability of its grass host, maize (Zea mays). Methodology/Principal Findings In a greenhouse and field study, we investigated WCR development and oviposition on Miscanthus. The suitability of Miscanthus for WCR development varied across different WCR populations. Data trends indicate that WCR populations that express behavioural resistance to crop rotation performed as well on Miscanthus as on maize. Over the entire study, total adult WCR emergence from Miscanthus (212 WCR) was 29.6% of that from maize (717 WCR). Adult dry weight was 75–80% that of WCR from maize; female emergence patterns on Miscanthus were similar to females developing on maize. There was no difference in the mean no. of WCR eggs laid at the base of Miscanthus and maize in the field. Conclusions/Significance Field oviposition and significant WCR emergence from Miscanthus raises many questions about the nature of likely interactions between Miscanthus, maize and WCR and the potential for Miscanthus to act as a refuge or reservoir for Corn Belt WCR. Responsible consideration of the benefits and risks associated with Corn Belt Miscanthus are critical to protecting an agroecosystem that we depend on for food, feed, and increasingly, fuel. Implications for European agroecosystems in which Miscanthus is being proposed are also discussed in light of the WCR's recent invasion into Europe. PMID:20016814

  4. Ichthyophonus-infected walleye pollock Theragra chalcogramma (Pallas) in the eastern Bering Sea: a potential reservoir of infections in the North Pacific.

    PubMed

    White, V C; Morado, J F; Friedman, C S

    2014-07-01

    In 2003, the Alaska walleye pollock industry reported product quality issues attributed to an unspecified parasite in fish muscle. Using molecular and histological methods, we identified the parasite in Bering Sea pollock as Ichthyophonus. Infected pollock were identified throughout the study area, and prevalence was greater in adults than in juveniles. This study not only provides the first documented report of Ichthyophonus in any fish species captured in the Bering Sea, but also reveals that the parasite has been present in this region for nearly 20 years and is not a recent introduction. Sequence analysis of 18S rDNA from Ichthyophonus in pollock revealed that consensus sequences were identical to published parasite sequences from Pacific herring and Yukon River Chinook salmon. Results from this study suggest potential for Ichthyophonus exposures from infected pollock via two trophic pathways; feeding on whole fish as prey and scavenging on industry-discharged offal. Considering the notable Ichthyophonus levels in pollock, the low host specificity of the parasite and the role of this host as a central prey item in the Bering Sea, pollock likely serve as a key Ichthyophonus reservoir for other susceptible hosts in the North Pacific. PMID:23941303

  5. Geology, reservoir engineering and methane hydrate potential of the Walakpa Gas Field, North Slope, Alaska

    SciTech Connect

    Glenn, R.K.; Allen, W.W.

    1992-12-01

    The Walakpa Gas Field, located near the city of Barrow on Alaska's North Slope, has been proven to be methane-bearing at depths of 2000--2550 feet below sea level. The producing formation is a laterally continuous, south-dipping, Lower Cretaceous shelf sandstone. The updip extent of the reservoir has not been determined by drilling, but probably extends to at least 1900 feet below sea level. Reservoir temperatures in the updip portion of the reservoir may be low enough to allow the presence of in situ methane hydrates. Reservoir net pay however, decreases to the north. Depths to the base of permafrost in the area average 940 feet. Drilling techniques and production configuration in the Walakpa field were designed to minimize formation damage to the reservoir sandstone and to eliminate methane hydrates formed during production. Drilling development of the Walakpa field was a sequential updip and lateral stepout from a previously drilled, structurally lower confirmation well. Reservoir temperature, pressure, and gas chemistry data from the development wells confirm that they have been drilled in the free-methane portion of the reservoir. Future studies in the Walakpa field are planned to determine whether or not a component of the methane production is due to the dissociation of updip in situ hydrates.

  6. Muddy and dolomitic rip-up clasts in Triassic fluvial sandstones: Origin and impact on potential reservoir properties (Argana Basin, Morocco)

    NASA Astrophysics Data System (ADS)

    Henares, Saturnina; Arribas, Jose; Cultrone, Giuseppe; Viseras, Cesar

    2016-06-01

    The significance of rip-up clasts as sandstone framework grains is frequently neglected in the literature being considered as accessory components in bulk sandstone composition. However, this study highlights the great value of muddy and dolomitic rip-up clast occurrence as: (a) information source about low preservation potential from floodplain deposits and (b) key element controlling host sandstone diagenetic evolution and thus ultimate reservoir quality. High-resolution petrographic analysis on Triassic fluvial sandstones from Argana Basin (T6 and T7/T8 units) highlights the significance of different types of rip-up clasts as intrabasinal framework components of continental sediments from arid climates. On the basis of their composition and ductility, three main types are distinguished: (a) muddy rip-up clasts, (b) dolomitic muddy rip-up clasts and (c) dolomite crystalline rip-up clasts. Spatial distribution of different types is strongly facies-related according to grain size. Origin of rip-up clasts is related to erosion of coeval phreatic dolocretes, in different development stages, and associated muddy floodplain sediments. Cloudy cores with abundant inclusions and clear outer rims of dolomite crystals suggest a first replacive and a subsequent displacive growth, respectively. Dolomite crystals are almost stoichiometric. This composition is very similar to that of early sandstone dolomite cement, supporting phreatic dolocretes as dolomite origin in both situations. Sandstone diagenesis is dominated by mechanical compaction and dolomite cementation. A direct correlation exists between: (1) muddy rip-up clast abundance and early reduction of primary porosity by compaction with irreversible loss of intergranular volume (IGV); and (2) occurrence of dolomitic rip-up clasts and dolomite cement nucleation in host sandstone, occluding adjacent pores but preserving IGV. Both processes affect reservoir quality by generation of vertical and 3D fluid flow baffles and

  7. Potential health impact and genotoxicity analysis of drinking source water from Liuxihe Reservoir (P.R. China).

    PubMed

    Wang, Weili; Li, Mei; Cui, Yibin; Gao, Xiangyu; Chen, Kun; Qian, Xin

    2014-05-01

    Water from the Liuxihe Reservoir (a source of drinking water for Guangzhou City, P. R. China) was analyzed for semi-volatile organic compounds (SVOCs) and the results were used for a potential health impact assessment and genotoxicity test with the microalgae Euglena gracilis. The SVOCs were tested using USEPA Method 525.2, and the health risk assessment was conducted at a screening level using the hazard quotient (HQ) approach. Alkaline single-cell gel electrophoresis (comet assay) was used to evaluate DNA damage and determine the genotoxicity of the source water. The concentrations of the SVOCs in Liuxihe Reservoir were very low and phthalic acid esters were the main SVOCs present. The mean HQ values of pollutants were all less than one, indicating no risk. However, the lifetime carcinogenic risks (LCRs) were found to be close to the threshold of 1.00E-5. The results show that the water in the Liuxihe Reservoir might pose a potential carcinogenic risk to local residents. The highly concentrated extracts of the water samples could induce DNA damage in the microalgal cells and a dose-effect relationship was identified. These results showed that Liuxihe Reservoir water, as a source of drinking water, could pose a potential LCR to local consumers. PMID:24429671

  8. Amoebae as Potential Environmental Hosts for Mycobacterium ulcerans and Other Mycobacteria, but Doubtful Actors in Buruli Ulcer Epidemiology

    PubMed Central

    Gryseels, Sophie; Amissah, Diana; Durnez, Lies; Vandelannoote, Koen; Leirs, Herwig; De Jonckheere, Johan; Portaels, Françoise; Ablordey, Anthony; Eddyani, Miriam

    2012-01-01

    Background The reservoir and mode of transmission of Mycobacterium ulcerans, the causative agent of Buruli ulcer, remain unknown. Ecological, genetic and epidemiological information nonetheless suggests that M. ulcerans may reside in aquatic protozoa. Methodology/Principal Findings We experimentally infected Acanthamoeba polyphaga with M. ulcerans and found that the bacilli were phagocytised, not digested and remained viable for the duration of the experiment. Furthermore, we collected 13 water, 90 biofilm and 45 detritus samples in both Buruli ulcer endemic and non-endemic communities in Ghana, from which we cultivated amoeboid protozoa and mycobacteria. M. ulcerans was not isolated, but other mycobacteria were as frequently isolated from intracellular as from extracellular sources, suggesting that they commonly infect amoebae in nature. We screened the samples as well as the amoeba cultures for the M. ulcerans markers IS2404, IS2606 and KR-B. IS2404 was detected in 2% of the environmental samples and in 4% of the amoeba cultures. The IS2404 positive amoeba cultures included up to 5 different protozoan species, and originated both from Buruli ulcer endemic and non-endemic communities. Conclusions/Significance This is the first report of experimental infection of amoebae with M. ulcerans and of the detection of the marker IS2404 in amoeba cultures isolated from the environment. We conclude that amoeba are potential natural hosts for M. ulcerans, yet remain sceptical about their implication in the transmission of M. ulcerans to humans and their importance in the epidemiology of Buruli ulcer. PMID:22880141

  9. Recurrent paediatric pinworm infection of the vagina as a potential reservoir for Enterobius vermicularis.

    PubMed

    Kashyap, B; Samantray, J C; Kumar, S; Jhamb, R; Singh, A K; Kaur, I R

    2014-09-01

    Enterobius vermicularis infection remains one of the most common parasitic infections, particularly prevalent in children. Enterobiasis, although not usually dangerous, may cause significant morbidity. Elimination of the parasite from a family or an institution often poses problems, either because of an incomplete cure or re-infection. While there have been limited reports of ectopic enterobiasis throughout the world, ours is probably one of the rarest reports of recurrent vaginal E. vermicularis infection in the absence of any gastrointestinal symptoms despite complete treatment. A 4-year-old girl presented with recurrent episodes of vulval itching on 3-4 occasions over 2 years. There was no pruritis ani nor urinary/gastrointestinal complaints. The vulva was inflamed with 4-5 living worms, 6-7 mm in length, emerging from the anterior vaginal fornix, but with no vaginal discharge. Direct microscopic examination of vaginal swabs revealed adult worms of Enterobius but no eggs. Repeated stool samples from the patient, parents and a sibling were negative. The patient was treated orally with 100 mg of mebendazole for 3 days followed by two more courses at 3-week intervals over a period of 3 months. Recurrent vaginal enterobiasis despite complete treatment and in the absence of any gastrointestinal involvement suggests that the vagina is a potential reservoir for E. vermicularis, which supports the theory of rare ectopic enterobiasis through the ascending pathway of the female genital tract. PMID:23721910

  10. Tick-Borne Transmission of Two Genetically Distinct Anaplasma marginale Strains following Superinfection of the Mammalian Reservoir Host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strain superinfection affects the dynamics of epidemiological spread of pathogens through a host population. Superinfection has recently been shown to occur for genetically distinct strains of the tick-borne pathogen Anaplasma marginale that encode distinctly different surface protein variants. Supe...

  11. Current state, sources, and potential risk of heavy metals in sediments of Three Gorges Reservoir, China.

    PubMed

    Bing, Haijian; Zhou, Jun; Wu, Yanhong; Wang, Xiaoxiao; Sun, Hongyang; Li, Rui

    2016-07-01

    Heavy metal (HM) contamination in sediments of Three Gorges Reservoir (TGR) is a particularly important issue for the safety of water quality due to the potential threats of metal toxicity to local and downstream human health. Surface sediments from riparian and submerged areas in the entire TGR mainstream were collected in 2014 to investigate the spatial distribution of HMs (Cd, Cu, Pb, and Zn), identify their possible sources, and assess their potential risk by multiple indices and metal fraction. Results showed that the concentrations of HMs in the sediments increased after the TGR operation, but were lower than those in other Chinese rivers of developed areas. The acid-soluble Cd accounted for more than 50% of total Cd in the sediments, whereas that of other HMs was very low. The Cd concentrations in the riparian sediments increased towards the dam; however, other metals in the riparian sediments and all HMs in the submerged sediments did not show any regular variation trend spatially. The stocks of HMs were significantly higher in the submerged sediments than in the riparian sediments. The high accumulation of HMs in the riparian sediments emerged between Fuling and Fengjie, and those in the submerged sediments existed in the near dam areas. Grain size and Fe/Mn oxides controlled the mobility and transfer of HMs in the sediments. Human activity in the catchment including industrial and agricultural production, shipping industry, mining, etc., increased inputs of HMs in the sediments, and altered their spatial distribution patterns. The sediments were moderately to highly contaminated by Cd, and slightly contaminated by other HMs. The results indicate the current priority of Cd contamination in the TGR, and will conduce to ecological protection in the TGR region. PMID:27131806

  12. Infection levels of proteocephalidean cestodes in Cichla piquiti (Osteichthyes: Cichlidae) of the Volta Grande Reservoir, Minas Gerais, Brazil, relative to host body weight and gender.

    PubMed

    Martins, M L; Pereira, J; de Chambrier, A; Mouriño, J L P

    2011-12-01

    We evaluated the relationship between infection by proteocephalid cestodes and the sex and weight classes of tucunaré (Cichla piquiti) captured between August 1999 and June 2001 in the Volta Grande Reservoir, Minas Gerais, Brazil. A total of 96 fish, 75.9 ± 9.3% males and 88.9 ± 6.4% females, were parasitized by Proteocephalus macrophallus and P. microscopicus, with total mean intensities of 76.6 ± 23.9 and 145.2 ± 36.7, respectively, during this period. In the majority of the months analysed, males showed 71.4-100% prevalence of parasitism and females 80-100%. Although there was no significant difference, females showed a higher mean intensity of infection (145.2 ± 36.7) than males (76.6 ± 23.9). Fish weighing 300-800 g showed a higher mean abundance of parasites (P < 0.05) compared with the biggest specimens weighing 801-2750 g. Analysing both males and females together, the greatest mean intensities of infection were found in October and December (P < 0.05) independent of the year, which coincides with the months of highest rainfall. These results show that fish living in reservoirs may be more susceptible to intermediate hosts than those that live in rivers. PMID:21208512

  13. Real-Time PCR Investigation of Potential Vectors, Reservoirs, and Shedding Patterns of Feline Hemotropic Mycoplasmas▿

    PubMed Central

    Willi, Barbara; Boretti, Felicitas S.; Meli, Marina L.; Bernasconi, Marco V.; Casati, Simona; Hegglin, Daniel; Puorger, Maria; Neimark, Harold; Cattori, Valentino; Wengi, Nicole; Reusch, Claudia E.; Lutz, Hans; Hofmann-Lehmann, Regina

    2007-01-01

    Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, “Candidatus Mycoplasma haemominutum,” and “Candidatus Mycoplasma turicensis.” The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, “Ca. Mycoplasma turicensis” DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and “Ca. Mycoplasma haemominutum” DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland. PMID:17468284

  14. Real-time PCR investigation of potential vectors, reservoirs, and shedding patterns of feline hemotropic mycoplasmas.

    PubMed

    Willi, Barbara; Boretti, Felicitas S; Meli, Marina L; Bernasconi, Marco V; Casati, Simona; Hegglin, Daniel; Puorger, Maria; Neimark, Harold; Cattori, Valentino; Wengi, Nicole; Reusch, Claudia E; Lutz, Hans; Hofmann-Lehmann, Regina

    2007-06-01

    Three hemotropic mycoplasmas have been identified in pet cats: Mycoplasma haemofelis, "Candidatus Mycoplasma haemominutum," and "Candidatus Mycoplasma turicensis." The way in which these agents are transmitted is largely unknown. Thus, this study aimed to investigate fleas, ticks, and rodents as well as saliva and feces from infected cats for the presence of hemotropic mycoplasmas, to gain insight into potential transmission routes for these agents. DNA was extracted from arthropods and from rodent blood or tissue samples from Switzerland and from salivary and fecal swabs from two experimentally infected and six naturally infected cats. All samples were analyzed with real-time PCR, and some positive samples were confirmed by sequencing. Feline hemotropic mycoplasmas were detected in cat fleas and in a few Ixodes sp. and Rhipicephalus sp. ticks collected from animals but not in ticks collected from vegetation or from rodent samples, although the latter were frequently Mycoplasma coccoides PCR positive. When shedding patterns of feline hemotropic mycoplasmas were investigated, "Ca. Mycoplasma turicensis" DNA was detected in saliva and feces at the early but not at the late phase of infection. M. haemofelis and "Ca. Mycoplasma haemominutum" DNA was not amplified from saliva and feces of naturally infected cats, despite high hemotropic mycoplasma blood loads. Our results suggest that besides an ostensibly indirect transmission by fleas, direct transmission through saliva and feces at the early phase of infection could play a role in the epizootiology of feline hemotropic mycoplasmas. Neither the investigated tick nor the rodent population seems to represent a major reservoir for feline hemotropic mycoplasmas in Switzerland. PMID:17468284

  15. Geology and hydrocarbon reservoir potential of the Pituil and Barreal Formations, Calingasta Valley, western Argentina

    SciTech Connect

    Janks, J.S. ); Lopez-Gamundi, O.R.; Siegele, P.K. )

    1990-05-01

    The Calingasta basin is one of the north-south-trending intermontane basins informally known as the Bolsones. The stratigraphy consists of lower Paleozoic metamorphic basement overlain by sediments and volcanics of upper Paleozoic through Cenozoic age. Three distinct geological provinces are recognized within the Bolsones region: Sierras Pampeanas, Precordillera, and Cordillera Frontal. Outcrop samples from the Permian Pituil and Triassic Barreal formations from the Tamberias region of the Sierras Pampeanas province were analyzed to determine the composition, porosity type, and diagenetic modification. The Pituil formation is a shallow marine sequence overlying Carboniferous glaciomarine sediments. They grade eastward into nonmarine lacustrine, deltaic, and fluvial sandstones. The rocks are fine- to medium-grained litharenites with porosities of 6-10 %. Diagenetic modifications include quartz overgrowths, unstable grain dissolution, carbonate cements, pyrite, and kaolinite. Triassic deposits occur on the western flank of the Precordillera, overlying a basement of volcanics and metasedimentary rocks. The Triassic sediments can be several hundreds of meters thick; deposition occurred in fluvial to lacustrine environments. These clastic sediments are considered to be northern extensions of the hydrocarbon-productive sediments in the Cuyo basin. The Barreal formation ranges from clay-rich lithic wackes and shales to conglomeratic, volcaniclastic litharenites and sublitharenites. Framework grains consist of quartz, feldspars, rock fragments, and, rarely, glass shards. Cements include zeolites, carbonates, chalcedony, pyrite, and clays. Tuffs are found at certain intervals within the section; alteration to iron-rich smectite is common. Reservoir potential is highly variable. Porosities range from as low as 5% to greater than 25%.

  16. Seroprevalence of Trypanosoma cruzi Among Eleven Potential Reservoir Species from Six States Across the Southern United States

    PubMed Central

    Brown, Emily L.; Roellig, Dawn M.; Gompper, Matthew E.; Monello, Ryan J.; Wenning, Krista M.; Gabriel, Mourad W.

    2010-01-01

    Abstract Trypanosoma cruzi, the causative agent of Chagas' disease, is a substantial public health concern in Latin America. Although rare in humans and domestic animals in the United States, T. cruzi is commonly detected in some wildlife species, most commonly raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana). To increase our understanding of the reservoir host species range and geographic distribution, 11 species of mammals from six states spanning the known range of T. cruzi (Arizona, California, Florida, Georgia, Missouri, and Virginia) were tested for antibodies to T. cruzi using indirect immunofluorescent antibody testing. In addition, culture isolation attempts were conducted on a limited number of animals from Georgia and Florida. Evidence of T. cruzi was found in every state except California; however, low numbers of known reservoirs were tested in California. In general, the highest seroprevalence rates were found in raccoons (0–68%) and opossums (17–52%), but antibodies to T. cruzi were also detected in small numbers of striped skunks (Mephitis mephitis) from Arizona and Georgia, bobcats (Lynx rufus) from Georgia, two coyotes (Canis latrans) from Georgia and Virginia, and a ringtail (Bassariscus astutus) from Arizona. Culture-based prevalence rates for raccoons were significantly greater than those for opossums; however, seroprevalences of raccoons and opossums from several geographic locations in Georgia and Florida were not different, indicating that exposure rates of these two species are similar within these areas. For both raccoons and opossums, seroprevalence was significantly higher in females than in males. No difference was detected in seroprevalence between adults and juveniles and between animals caught in urban and rural locations. Our results indicate that T. cruzi prevalence varies by host species, host characteristics, and geographic region and provides data to guide future studies on the natural history of T. cruzi

  17. Seroprevalence of Trypanosoma cruzi among eleven potential reservoir species from six states across the southern United States.

    PubMed

    Brown, Emily L; Roellig, Dawn M; Gompper, Matthew E; Monello, Ryan J; Wenning, Krista M; Gabriel, Mourad W; Yabsley, Michael J

    2010-10-01

    Trypanosoma cruzi, the causative agent of Chagas' disease, is a substantial public health concern in Latin America. Although rare in humans and domestic animals in the United States, T. cruzi is commonly detected in some wildlife species, most commonly raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana). To increase our understanding of the reservoir host species range and geographic distribution, 11 species of mammals from six states spanning the known range of T. cruzi (Arizona, California, Florida, Georgia, Missouri, and Virginia) were tested for antibodies to T. cruzi using indirect immunofluorescent antibody testing. In addition, culture isolation attempts were conducted on a limited number of animals from Georgia and Florida. Evidence of T. cruzi was found in every state except California; however, low numbers of known reservoirs were tested in California. In general, the highest seroprevalence rates were found in raccoons (0-68%) and opossums (17-52%), but antibodies to T. cruzi were also detected in small numbers of striped skunks (Mephitis mephitis) from Arizona and Georgia, bobcats (Lynx rufus) from Georgia, two coyotes (Canis latrans) from Georgia and Virginia, and a ringtail (Bassariscus astutus) from Arizona. Culture-based prevalence rates for raccoons were significantly greater than those for opossums; however, seroprevalences of raccoons and opossums from several geographic locations in Georgia and Florida were not different, indicating that exposure rates of these two species are similar within these areas. For both raccoons and opossums, seroprevalence was significantly higher in females than in males. No difference was detected in seroprevalence between adults and juveniles and between animals caught in urban and rural locations. Our results indicate that T. cruzi prevalence varies by host species, host characteristics, and geographic region and provides data to guide future studies on the natural history of T. cruzi in the

  18. Vertebrate Hosts as Islands: Dynamics of Selection, Immigration, Loss, Persistence, and Potential Function of Bacteria on Salamander Skin.

    PubMed

    Loudon, Andrew H; Venkataraman, Arvind; Van Treuren, William; Woodhams, Douglas C; Parfrey, Laura Wegener; McKenzie, Valerie J; Knight, Rob; Schmidt, Thomas M; Harris, Reid N

    2016-01-01

    Skin bacterial communities can protect amphibians from a fungal pathogen; however, little is known about how these communities are maintained. We used a neutral model of community ecology to identify bacteria that are maintained on salamanders by selection or by dispersal from a bacterial reservoir (soil) and ecological drift. We found that 75% (9/12) of bacteria that were consistent with positive selection, <1% of bacteria that were consistent with random dispersal and none of the bacteria that were consistent under negative selection had a 97% or greater match to antifungal isolates. Additionally we performed an experiment where salamanders were either provided or denied a bacterial reservoir and estimated immigration and loss (emigration and local extinction) rates of bacteria on salamanders in both treatments. Loss was strongly related to bacterial richness, suggesting competition is important for structuring the community. Bacteria closely related to antifungal isolates were more likely to persist on salamanders with or without a bacterial reservoir, suggesting they had a competitive advantage. Furthermore, over-represented and under-represented operational taxonomic units (OTUs) had similar persistence on salamanders when a bacterial reservoir was present. However, under-represented OTUs were less likely to persist in the absence of a bacterial reservoir, suggesting that the over-represented and under-represented bacteria were selected against or for on salamanders through time. Our findings from the neutral model, migration and persistence analyses show that bacteria that exhibit a high similarity to antifungal isolates persist on salamanders, which likely protect hosts against pathogens and improve fitness. This research is one of the first to apply ecological theory to investigate assembly of host associated-bacterial communities, which can provide insights for probiotic bioaugmentation as a conservation strategy against disease. PMID:27014249

  19. Vertebrate Hosts as Islands: Dynamics of Selection, Immigration, Loss, Persistence, and Potential Function of Bacteria on Salamander Skin

    PubMed Central

    Loudon, Andrew H.; Venkataraman, Arvind; Van Treuren, William; Woodhams, Douglas C.; Parfrey, Laura Wegener; McKenzie, Valerie J.; Knight, Rob; Schmidt, Thomas M.; Harris, Reid N.

    2016-01-01

    Skin bacterial communities can protect amphibians from a fungal pathogen; however, little is known about how these communities are maintained. We used a neutral model of community ecology to identify bacteria that are maintained on salamanders by selection or by dispersal from a bacterial reservoir (soil) and ecological drift. We found that 75% (9/12) of bacteria that were consistent with positive selection, <1% of bacteria that were consistent with random dispersal and none of the bacteria that were consistent under negative selection had a 97% or greater match to antifungal isolates. Additionally we performed an experiment where salamanders were either provided or denied a bacterial reservoir and estimated immigration and loss (emigration and local extinction) rates of bacteria on salamanders in both treatments. Loss was strongly related to bacterial richness, suggesting competition is important for structuring the community. Bacteria closely related to antifungal isolates were more likely to persist on salamanders with or without a bacterial reservoir, suggesting they had a competitive advantage. Furthermore, over-represented and under-represented operational taxonomic units (OTUs) had similar persistence on salamanders when a bacterial reservoir was present. However, under-represented OTUs were less likely to persist in the absence of a bacterial reservoir, suggesting that the over-represented and under-represented bacteria were selected against or for on salamanders through time. Our findings from the neutral model, migration and persistence analyses show that bacteria that exhibit a high similarity to antifungal isolates persist on salamanders, which likely protect hosts against pathogens and improve fitness. This research is one of the first to apply ecological theory to investigate assembly of host associated-bacterial communities, which can provide insights for probiotic bioaugmentation as a conservation strategy against disease. PMID:27014249

  20. Bacterial community diversity in a low-permeability oil reservoir and its potential for enhancing oil recovery.

    PubMed

    Xiao, Meng; Zhang, Zhong-Zhi; Wang, Jing-Xiu; Zhang, Guang-Qing; Luo, Yi-Jing; Song, Zhao-Zheng; Zhang, Ji-Yuan

    2013-11-01

    The diversity of indigenous bacterial community and the functional species in the water samples from three production wells of a low permeability oil reservoir was investigated by high-throughput sequencing technology. The potential of application of indigenous bacteria for enhancing oil recovery was evaluated by examination of the effect of bacterial stimulation on the formation water-oil-rock surface interactions and micromodel test. The results showed that production well 88-122 had the most diverse bacterial community and functional species. The broth of indigenous bacteria stimulated by an organic nutrient activator at aerobic condition changed the wettability of the rock surface from oil-wet to water-wet. Micromodel test results showed that flooding using stimulated indigenous bacteria following water flooding improved oil recovery by 6.9% and 7.7% in fractured and unfractured micromodels, respectively. Therefore, the zone of low permeability reservoir has a great potential for indigenous microbial enhanced oil recovery. PMID:23994957

  1. Potentially bioavailable iron delivery by iceberg-hosted sediments and atmospheric dust to the polar oceans

    NASA Astrophysics Data System (ADS)

    Raiswell, Robert; Hawkings, Jon R.; Benning, Liane G.; Baker, Alex R.; Death, Ros; Albani, Samuel; Mahowald, Natalie; Krom, Michael D.; Poulton, Simon W.; Wadham, Jemma; Tranter, Martyn

    2016-07-01

    Iceberg-hosted sediments and atmospheric dust transport potentially bioavailable iron to the Arctic and Southern oceans as ferrihydrite. Ferrihydrite is nanoparticulate and more soluble, as well as potentially more bioavailable, than other iron (oxyhydr)oxide minerals (lepidocrocite, goethite, and hematite). A suite of more than 50 iceberg-hosted sediments contain a mean content of 0.076 wt % Fe as ferrihydrite, which produces iceberg-hosted Fe fluxes ranging from 0.7 to 5.5 and 3.2 to 25 Gmoles yr-1 to the Arctic and Southern oceans respectively. Atmospheric dust (with little or no combustion products) contains a mean ferrihydrite Fe content of 0.038 wt % (corresponding to a fractional solubility of ˜ 1 %) and delivers much smaller Fe fluxes (0.02-0.07 Gmoles yr-1 to the Arctic Ocean and 0.0-0.02 Gmoles yr-1 to the Southern Ocean). New dust flux data show that most atmospheric dust is delivered to sea ice where exposure to melting/re-freezing cycles may enhance fractional solubility, and thus fluxes, by a factor of approximately 2.5. Improved estimates for these particulate sources require additional data for the iceberg losses during fjord transit, the sediment content of icebergs, and samples of atmospheric dust delivered to the polar regions.

  2. Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts.

    PubMed

    Mgode, Georgies F; Machang'u, Robert S; Mhamphi, Ginethon G; Katakweba, Abdul; Mulungu, Loth S; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A; Belmain, Steven R

    2015-12-01

    The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries. PMID:26624890

  3. Leptospira Serovars for Diagnosis of Leptospirosis in Humans and Animals in Africa: Common Leptospira Isolates and Reservoir Hosts

    PubMed Central

    Mgode, Georgies F.; Machang’u, Robert S.; Mhamphi, Ginethon G.; Katakweba, Abdul; Mulungu, Loth S.; Durnez, Lies; Leirs, Herwig; Hartskeerl, Rudy A.; Belmain, Steven R.

    2015-01-01

    The burden of leptospirosis in humans and animals in Africa is higher than that reported from other parts of the world. However, the disease is not routinely diagnosed in the continent. One of major factors limiting diagnosis is the poor availability of live isolates of locally circulating Leptospira serovars for inclusion in the antigen panel of the gold standard microscopic agglutination test (MAT) for detecting antibodies against leptospirosis. To gain insight in Leptospira serovars and their natural hosts occurring in Tanzania, concomitantly enabling the improvement of the MAT by inclusion of fresh local isolates, a total of 52 Leptospira isolates were obtained from fresh urine and kidney homogenates, collected between 1996 and 2006 from small mammals, cattle and pigs. Isolates were identified by serogrouping, cross agglutination absorption test (CAAT), and molecular typing. Common Leptospira serovars with their respective animal hosts were: Sokoine (cattle and rodents); Kenya (rodents and shrews); Mwogolo (rodents); Lora (rodents); Qunjian (rodent); serogroup Grippotyphosa (cattle); and an unknown serogroup from pigs. Inclusion of local serovars particularly serovar Sokoine in MAT revealed a 10-fold increase in leptospirosis prevalence in Tanzania from 1.9% to 16.9% in rodents and 0.26% to 10.75% in humans. This indicates that local serovars are useful for diagnosis of human and animal leptospirosis in Tanzania and other African countries. PMID:26624890

  4. A potential target gene for the host-directed therapy of mycobacterial infection in murine macrophages.

    PubMed

    Bao, Zhang; Chen, Ran; Zhang, Pei; Lu, Shan; Chen, Xing; Yao, Yake; Jin, Xiaozheng; Sun, Yilan; Zhou, Jianying

    2016-09-01

    Mycobacterium tuberculosis (MTB), one of the major bacterial pathogens for lethal infectious diseases, is capable of surviving within the phagosomes of host alveolar macrophages; therefore, host genetic variations may alter the susceptibility to MTB. In this study, to identify host genes exploited by MTB during infection, genes were non-selectively inactivated using lentivirus-based antisense RNA methods in Raw264.7 macrophages, and the cells that survived virulent MTB infection were then screened. Following DNA sequencing of the surviving cell clones, 26 host genes affecting susceptibility to MTB were identified and their pathways were analyzed by bioinformatics analysis. In total, 9 of these genes were confirmed as positive regulators of collagen α-5(IV) chain (Col4a5) expression, a gene encoding a type IV collagen subunit present on the cell surface. The knockdown of Col4a5 consistently suppressed intracellular mycobacterial viability, promoting the survival of Raw264.7 macrophages following mycobacterial infection. Furthermore, Col4a5 deficiency lowered the pH levels of intracellular vesicles, including endosomes, lysosomes and phagosomes in the Raw264.7 cells. Finally, the knockdown of Col4a5 post-translationally increased microsomal vacuolar-type H+-ATPase activity in macrophages, leading to the acidification of intracellular vesicles. Our findings reveal a novel role for Col4a5 in the regulation of macrophage responses to mycobacterial infection and identify Col4a5 as a potential target for the host-directed anti-mycobacterial therapy. PMID:27432120

  5. A potential target gene for the host-directed therapy of mycobacterial infection in murine macrophages

    PubMed Central

    Bao, Zhang; Chen, Ran; Zhang, Pei; Lu, Shan; Chen, Xing; Yao, Yake; Jin, Xiaozheng; Sun, Yilan; Zhou, Jianying

    2016-01-01

    Mycobacterium tuberculosis (MTB), one of the major bacterial pathogens for lethal infectious diseases, is capable of surviving within the phagosomes of host alveolar macrophages; therefore, host genetic variations may alter the susceptibility to MTB. In this study, to identify host genes exploited by MTB during infection, genes were non-selectively inactivated using lentivirus-based antisense RNA methods in RAW264.7 macrophages, and the cells that survived virulent MTB infection were then screened. Following DNA sequencing of the surviving cell clones, 26 host genes affecting susceptibility to MTB were identified and their pathways were analyzed by bioinformatics analysis. In total, 9 of these genes were confirmed as positive regulators of collagen α-5(IV) chain (Col4a5) expression, a gene encoding a type IV collagen subunit present on the cell surface. The knockdown of Col4a5 consistently suppressed intracellular mycobacterial viability, promoting the survival of RAW264.7 macrophages following mycobacterial infection. Furthermore, Col4a5 deficiency lowered the pH levels of intracellular vesicles, including endosomes, lysosomes and phagosomes in the RAW264.7 cells. Finally, the knockdown of Col4a5 post-translationally increased microsomal vacuolar-type H+-ATPase activity in macrophages, leading to the acidification of intracellular vesicles. Our findings reveal a novel role for Col4a5 in the regulation of macrophage responses to mycobacterial infection and identify Col4a5 as a potential target for the host-directed anti-mycobacterial therapy. PMID:27432120

  6. Studies on rodents role as reservoir hosts of leishmaniasis with specical reference to their ectoparasites in Suez Governorate.

    PubMed

    Shoukry, Nahla M; El-Naggar, Mostafa H; Darwish, Ahmed B; Soliman, Belal A; El-Sawaf, Bahira M

    2006-04-01

    The distribution of rodents was studied in three different habitats. Seven rodent species were identified: Rattus norvegicus, R. alexandrinus, R. frugivorous, Mus musculus, Acomys russatus, Meriones sacramenti and Gerbillus pyramidum. The species distribution varied with the habitat type. The highest density of rodents was in July and August and the lowest one was in January. However, some species were collected all the year round. The rodents were investigated for the endo- and ecto-parasites. No Leishmania parasites were found. The ectoparasites were: Xenopsylla cheopis, Leptopsylla segnis and Ctenocephalides felis, Polyplax spinulos, Hyalomma dromedarii (nymph) and Echinolaelaps echidninus and Hemolaelaps glassgowi. Ecto-parasites were on rodents all year-round in domestic habitat and peridomestic habitats. In wild one, ecto-parasites activity was from March to December. The rodents' role as reservoir for L. major was experimentally studied. Rodents inoculated with L. major together with hamster and BALB-c mice developed cutaneous lesions. The active lesions, the rodents' ecological habitats and the presence of insect-vector may pave the way to an epidemic zoonotic leishmaniasis role. PMID:16605103

  7. Shale, mudstone, and claystone as potential host rocks for underground emplacement of waste

    USGS Publications Warehouse

    Merewether, E.A.; Sharps, J.A.; Gill, J.R.; Cooley, M.E.

    1973-01-01

    In this report, the suitability of the argillaceous formations in the conterminous United States as host rocks for underground waste emplacement is reviewed in terms of available geologic information. The strata are considered mainly according to their dimensions, Depth, composition, permeability, structural and seismic history, and to the extent of drilling in the area. Shale, mudstone, and claystone of marine origin in areas of little structural deformation and seismic risks are generally the most promising. These include the Ohio Shale of Devonian age in northern Ohio and the Devonian-Mississippian Ellsworth Shale and Mississippian Coldwater Shale in Michigan. In-the Rocky Mountain states, the Pierre Shale and other thick shales of Late Cretaceous age are also potential host rocks.

  8. Modeling pollution potential input from the drainage basin into Barra Bonita reservoir, São Paulo - Brazil.

    PubMed

    Prado, R B; Novo, E M L M

    2015-05-01

    In this study multi-criteria modeling tools are applied to map the spatial distribution of drainage basin potential to pollute Barra Bonita Reservoir, São Paulo State, Brasil. Barra Bonita Reservoir Basin had undergone intense land use/land cover changes in the last decades, including the fast conversion from pasture into sugarcane. In this respect, this study answers to the lack of information about the variables (criteria) which affect the pollution potential of the drainage basin by building a Geographic Information System which provides their spatial distribution at sub-basin level. The GIS was fed by several data (geomorphology, pedology, geology, drainage network and rainfall) provided by public agencies. Landsat satellite images provided land use/land cover map for 2002. Ratings and weights of each criterion defined by specialists supported the modeling process. The results showed a wide variability in the pollution potential of different sub-basins according to the application of different criterion. If only land use is analyzed, for instance, less than 50% of the basin is classified as highly threatening to water quality and include sub basins located near the reservoir, indicating the importance of protection areas at the margins. Despite the subjectivity involved in the weighing processes, the multi-criteria analysis model allowed the simulation of scenarios which support rational land use polices at sub-basin level regarding the protection of water resources. PMID:26132013

  9. Reservoir framework and exploration potential of the Cleveland Formation (Western Anadarko Basin) using a sequence-stratigraphic model

    SciTech Connect

    Hentz, T.F. )

    1993-09-01

    The Upper Pennsylvanian (lower Missourian) Cleveland Formation has yielded more than 435 bcf on natural gas and more than 18.2 MM bbl of oil from a seven-county tight-gas area in the northeastern Texas panhandle. Regional study of the Cleveland and underlying Desmoinesian Marmaton Group siliciclastics established the sequence-stratigraphic framework to clarify the vertical and areal occurrence of Cleveland reservoirs, seals, and source rocks. Regionally distinctive facies stacking patterns in the study interval compose a sequence-stratigraphic framework of several westerly sourced systems tracts and three depositional sequences. Sequence 1 (S1) is characterized by landward- and seaward-stepping deltaic/strand-plain cycles (parasequences) deposited on the top-of-Oswego type 1 sequence boundary. A relative sea level drop with the onset of S2 deposition initiated development of a sand-rich incised-valley system (LST:iv) in the middle Cleveland that extended basinward of the lower Cleveland shelf break. Subsequent coastal onlap by thin deltaic systems of the overlying TST marks the start of decreased sediment influx during late Cleveland deposition, resulting in thinning of parasequences and an increase in carbonate beds in upper S2 and S3. Stratigraphic traps and pinch out of reservoir facies within small, southeast-plunging anticlines compose most traps in the producing area. Proximal delta-front and fluvial sandstones of the Cleveland upper HST and overlying LST:iv, respectively, are the primary reservoirs. The high-TOC, top-of-Marmaton marine-condensed section and thick prodeltaic and lower distal delta-front shales within the lower Cleveland HST are the probable source rocks. Distal deltaic shales of the middle Cleveland TST form most reservoir seals. Potential new reservoirs should be targeted at the updip terminations of systems tracts, at lapout positions of individual sand-rich HST and TST parasequences, and along LST:iv valley-margin stratal terminations.

  10. Volcanic settings and their reservoir potential: An outcrop analog study on the Miocene Tepoztlán Formation, Central Mexico

    NASA Astrophysics Data System (ADS)

    Lenhardt, Nils; Götz, Annette E.

    2011-07-01

    The reservoir potential of volcanic and associated sedimentary rocks is less documented in regard to groundwater resources, and oil and gas storage compared to siliciclastic and carbonate systems. Outcrop analog studies within a volcanic setting enable to identify spatio-temporal architectural elements and geometric features of different rock units and their petrophysical properties such as porosity and permeability, which are important information for reservoir characterization. Despite the wide distribution of volcanic rocks in Mexico, their reservoir potential has been little studied in the past. In the Valley of Mexico, situated 4000 m above the Neogene volcanic rocks, groundwater is a matter of major importance as more than 20 million people and 42% of the industrial capacity of the Mexican nation depend on it for most of their water supply. Here, we present porosity and permeability data of 108 rock samples representing five different lithofacies types of the Miocene Tepoztlán Formation. This 800 m thick formation mainly consists of pyroclastic rocks, mass flow and fluvial deposits and is part of the southern Transmexican Volcanic Belt, cropping out south of the Valley of Mexico and within the two states of Morelos and Mexico State. Porosities range from 1.4% to 56.7%; average porosity is 24.8%. Generally, permeabilities are low to median (0.2-933.3 mD) with an average permeability of 88.5 mD. The lavas are characterized by the highest porosity values followed by tuffs, conglomerates, sandstones and tuffaceous breccias. On the contrary, the highest permeabilities can be found in the conglomerates, followed by tuffs, tuffaceous breccias, sandstones and lavas. The knowledge of these petrophysical rock properties provides important information on the reservoir potential of volcanic settings to be integrated to 3D subsurface models.

  11. Hydrogen, a potential safeguard for graft-versus-host disease and graft ischemia-reperfusion injury?

    PubMed Central

    Yuan, Lijuan; Shen, Jianliang

    2016-01-01

    Post-transplant complications such as graft-versus-host disease and graft ischemia-reperfusion injury are crucial challenges in transplantation. Hydrogen can act as a potential antioxidant, playing a preventive role against post-transplant complications in animal models of multiple organ transplantation. Herein, the authors review the current literature regarding the effects of hydrogen on graft ischemia-reperfusion injury and graft-versus-host disease. Existing data on the effects of hydrogen on ischemia-reperfusion injury related to organ transplantation are specifically reviewed and coupled with further suggestions for future work. The reviewed studies showed that hydrogen (inhaled or dissolved in saline) improved the outcomes of organ transplantation by decreasing oxidative stress and inflammation at both the transplanted organ and the systemic levels. In conclusion, a substantial body of experimental evidence suggests that hydrogen can significantly alleviate transplantation-related ischemia-reperfusion injury and have a therapeutic effect on graft-versus-host disease, mainly via inhibition of inflammatory cytokine secretion and reduction of oxidative stress through several underlying mechanisms. Further animal experiments and preliminary human clinical trials will lay the foundation for hydrogen use as a drug in the clinic.

  12. Potential of immunomodulatory agents as adjunct host-directed therapies for multidrug-resistant tuberculosis.

    PubMed

    Zumla, Alimuddin; Rao, Martin; Dodoo, Ernest; Maeurer, Markus

    2016-01-01

    Treatment of multidrug-resistant tuberculosis (MDR-TB) is extremely challenging due to the virulence of the etiologic strains of Mycobacterium tuberculosis (M. tb), the aberrant host immune responses and the diminishing treatment options with TB drugs. New treatment regimens incorporating therapeutics targeting both M. tb and host factors are urgently needed to improve the clinical management outcomes of MDR-TB. Host-directed therapies (HDT) could avert destructive tuberculous lung pathology, facilitate eradication of M. tb, improve survival and prevent long-term functional disability. In this review we (1) discuss the use of HDT for cancer and other infections, drawing parallels and the precedent they set for MDR-TB treatment, (2) highlight preclinical studies of pharmacological agents commonly used in clinical practice which have HDT potential, and (3) outline developments in cellular therapy to promote clinically beneficial immunomodulation to improve treatment outcomes in patients with pulmonary MDR-TB. The use of HDTs as adjuncts to MDR-TB therapy requires urgent evaluation. PMID:27301245

  13. Potential accumulation of contaminated sediments in a reservoir of a high-Andean watershed: Morphodynamic connections with geochemical processes

    NASA Astrophysics Data System (ADS)

    Contreras, María. Teresa; Müllendorff, Daniel; Pastén, Pablo; Pizarro, Gonzalo E.; Paola, Chris; Escauriaza, Cristián.

    2015-05-01

    Rapid changes due to anthropic interventions in high-altitude environments, such as the Altiplano region in South America, require new approaches to understand the connections between physical and geochemical processes. Alterations of the water quality linked to the river morphology can affect the ecosystems and human development in the long term. The future construction of a reservoir in the Lluta River, located in northern Chile, will change the spatial distribution of arsenic-rich sediments, which can have significant effects on the lower parts of the watershed. In this investigation, we develop a coupled numerical model to predict and evaluate the interactions between morphodynamic changes in the Lluta reservoir, and conditions that can potentially desorb arsenic from the sediments. Assuming that contaminants are mobilized under anaerobic conditions, we calculate the oxygen concentration within the sediments to study the interactions of the delta progradation with the potential arsenic release. This work provides a framework for future studies aimed to analyze the complex connections between morphodynamics and water quality, when contaminant-rich sediments accumulate in a reservoir. The tool can also help to design effective risk management and remediation strategies in these extreme environments. This article was corrected on 15 JUNE 2015. See the end of the full text for details.

  14. A Newly Emerged Cutaneous Leishmaniasis Focus in Northern Israel and Two New Reservoir Hosts of Leishmania major

    PubMed Central

    Faiman, Roy; Abbasi, Ibrahim; Jaffe, Charles; Motro, Yoav; Nasereddin, Abdelmagid; Schnur, Lionel F.; Torem, Moshe; Pratlong, Francine; Dedet, Jean-Pierre; Warburg, Alon

    2013-01-01

    In 2006/7, 18 cases of cutaneous leishmaniasis (CL) were reported for the first time from Sde Eliyahu (pop. 650), a village in the Beit She'an valley of Israel. Between 2007–2011, a further 88 CL cases were diagnosed bringing the total to 106 (16.3% of the population of Sde Eliyahu). The majority of cases resided in the south-western part of the village along the perimeter fence. The causative parasite was identified as Leishmania major Yakimoff & Schokhor, 1914 (Kinetoplastida: Trypanosomatidae). Phlebotomus papatasi (Scopoli), 1786 (Diptera: Psychodidae) was found to be the most abundant phlebotomine species comprising 97% of the sand flies trapped inside the village, and an average of 7.9% of the females were positive for Leishmania ITS1 DNA. Parasite isolates from CL cases and a sand fly were characterized using several methods and shown to be L. major. During a comprehensive survey of rodents 164 Levant voles Microtus guentheri Danford & Alston, 1880 (Rodentia: Cricetidae) were captured in alfalfa fields bordering the village. Of these 27 (16.5%) tested positive for Leishmania ITS1 DNA and shown to be L. major by reverse line blotting. A very high percentage (58.3% - 21/36) of Tristram's jirds Meriones tristrami Thomas, 1892 (Rodentia: Muridae), found further away from the village also tested positive for ITS1 by PCR. Isolates of L. major were successfully cultured from the ear of a wild jird found positive by ITS1 PCR. Although none of the wild PCR-positive voles exhibited external pathology, laboratory-reared voles that were infected by intradermal L. major inoculation, developed patent lesions and sand flies became infected by feeding on the ears of these laboratory-infected voles. This is the first report implicating M. guentheri and M. tristrami as reservoirs of Leishmania. The widespread co-distribution of M. guentheri and P. papatasi, suggests a significant threat from the spread of CL caused by L. major in the Middle East, central Asia and southern

  15. Bile Acid Modifications at the Microbe-Host Interface: Potential for Nutraceutical and Pharmaceutical Interventions in Host Health.

    PubMed

    Joyce, Susan A; Gahan, Cormac G M

    2016-01-01

    Bile acids have emerged as important signaling molecules in the host, as they interact either locally or systemically with specific cellular receptors, in particular the farnesoid X receptor (FXR) and TGR5. These signaling functions influence systemic lipid and cholesterol metabolism, energy metabolism, immune homeostasis, and intestinal electrolyte balance. Through defined enzymatic activities, the gut microbiota can significantly modify the signaling properties of bile acids and therefore can have an impact upon host health. Alterations to the gut microbiota that influence bile acid metabolism are associated with metabolic disease, obesity, diarrhea, inflammatory bowel disease (IBD), Clostridium difficile infection, colorectal cancer, and hepatocellular carcinoma. Here, we examine the regulation of this gut-microbiota-liver axis in the context of bile acid metabolism and indicate how this pathway represents an important target for the development of new nutraceutical (diet and/or probiotics) and targeted pharmaceutical interventions. PMID:26772409

  16. Fossil micrometeorites from Finland — Basic features, scientific potential, and characteristics of the mesoproterozoic host rocks

    NASA Astrophysics Data System (ADS)

    Kettrup, Dirk; Deutsch, Alexander; Pihlaja, Pekka; Pesonen, Lauri J.

    The oldest known micrometeorites occur in the up to 1800 m thick Mesoproterozoic Satakunta sandstone in SW-Finland. This typical red bed formation covers a graben with the dimensions of about 15 × 100 km2. The Satakunta formation correlates with the Jotnian sandstone, overlaying at several locations in Fennoscandia basement rocks, which are part of the about 1.8 to 1.9 Ga old Svecofennian orogenic belt. The age of the Satakunta formation s.s. is not well constrained: Sedimentation may have already begun 1.65 Ga ago, and ended prior to the intrusion of the post-Jotnian diabases (1.26 Ga). The depositional environment of the Satakunta sediments was primarily mostly fluvial. In arkose sandstones of this formation, over 60 cosmic spherules (melted micrometeorites) have been identified. They belong to different mineralogical types, and display unaltered mineralogical and chemical features, including the presence of a still glassy matrix. Moreover, this cosmic dust lacks clear signs of mechanical transport. So far, the reasons for the excellent preservation of the micrometeorites are enigmatic. Conceivable factors that generally may have influenced the relatively high abundance of the micrometeorites in the Satakunta formation are (i) distinct concentrations mechanisms acting prior to the embedding into the host sediment, (ii) settling of the spherules at low energy, and lack of further transport in the sedimentological environment, (iii) only minor diagenetic compaction of the host sediments at rather reducing conditions, and (iv) a quite specific time-integrated temperature history for over a billion years. In this contribution, we outline sedimentological characteristics of both, barren, and spherule-carrying Satakunta lithologies. In addition, we discuss possible scenarios for deposition, and survival of this ancient cosmic dust. Understanding of these processes is of prime importance as red beds are quite common lithologies in the Earth's history, and hence, may

  17. Potential Animal Reservoirs of Toscana Virus and Coinfections with Leishmania infantum in Turkey

    PubMed Central

    Dincer, Ender; Gargari, Sepandar; Ozkul, Aykut; Ergunay, Koray

    2015-01-01

    Toscana virus (TOSV), a sandfly-borne phlebovirus, is an important agent of human meningoencephalitis in the Mediterranean region, for which vertebrates acting as reservoirs have not yet been determined. This study investigates TOSV and Leishmania infections in dogs, cats, sheep, and goats from Adana and Mersin provinces in southeastern Turkey. TOSV neutralizing antibodies were demonstrated in 40.4% of the dog and 4% of the goat samples. TOSV RNA was detected in 9.9% of the 252 samples that mainly comprise dogs (96%). Thus, canine species can be suggested as the candidate reservoirs of TOSV. Partial sequences revealed the activity of TOSV genotypes A and B. In two dogs presenting with symptoms of canine leishmaniasis, infections of TOSV genotype B and Leishmania infantum have been documented, describing the first report of coinfections with these agents. PMID:25711610

  18. Combining genomic sequencing methods to explore viral diversity and reveal potential virus-host interactions

    PubMed Central

    Chow, Cheryl-Emiliane T.; Winget, Danielle M.; White, Richard A.; Hallam, Steven J.; Suttle, Curtis A.

    2015-01-01

    Viral diversity and virus-host interactions in oxygen-starved regions of the ocean, also known as oxygen minimum zones (OMZs), remain relatively unexplored. Microbial community metabolism in OMZs alters nutrient and energy flow through marine food webs, resulting in biological nitrogen loss and greenhouse gas production. Thus, viruses infecting OMZ microbes have the potential to modulate community metabolism with resulting feedback on ecosystem function. Here, we describe viral communities inhabiting oxic surface (10 m) and oxygen-starved basin (200 m) waters of Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island, British Columbia using viral metagenomics and complete viral fosmid sequencing on samples collected between April 2007 and April 2010. Of 6459 open reading frames (ORFs) predicted across all 34 viral fosmids, 77.6% (n = 5010) had no homology to reference viral genomes. These fosmids recruited a higher proportion of viral metagenomic sequences from Saanich Inlet than from nearby northeastern subarctic Pacific Ocean (Line P) waters, indicating differences in the viral communities between coastal and open ocean locations. While functional annotations of fosmid ORFs were limited, recruitment to NCBI's non-redundant “nr” database and publicly available single-cell genomes identified putative viruses infecting marine thaumarchaeal and SUP05 proteobacteria to provide potential host linkages with relevance to coupled biogeochemical cycling processes in OMZ waters. Taken together, these results highlight the power of coupled analyses of multiple sequence data types, such as viral metagenomic and fosmid sequence data with prokaryotic single cell genomes, to chart viral diversity, elucidate genomic and ecological contexts for previously unclassifiable viral sequences, and identify novel host interactions in natural and engineered ecosystems. PMID:25914678

  19. Combining genomic sequencing methods to explore viral diversity and reveal potential virus-host interactions.

    PubMed

    Chow, Cheryl-Emiliane T; Winget, Danielle M; White, Richard A; Hallam, Steven J; Suttle, Curtis A

    2015-01-01

    Viral diversity and virus-host interactions in oxygen-starved regions of the ocean, also known as oxygen minimum zones (OMZs), remain relatively unexplored. Microbial community metabolism in OMZs alters nutrient and energy flow through marine food webs, resulting in biological nitrogen loss and greenhouse gas production. Thus, viruses infecting OMZ microbes have the potential to modulate community metabolism with resulting feedback on ecosystem function. Here, we describe viral communities inhabiting oxic surface (10 m) and oxygen-starved basin (200 m) waters of Saanich Inlet, a seasonally anoxic fjord on the coast of Vancouver Island, British Columbia using viral metagenomics and complete viral fosmid sequencing on samples collected between April 2007 and April 2010. Of 6459 open reading frames (ORFs) predicted across all 34 viral fosmids, 77.6% (n = 5010) had no homology to reference viral genomes. These fosmids recruited a higher proportion of viral metagenomic sequences from Saanich Inlet than from nearby northeastern subarctic Pacific Ocean (Line P) waters, indicating differences in the viral communities between coastal and open ocean locations. While functional annotations of fosmid ORFs were limited, recruitment to NCBI's non-redundant "nr" database and publicly available single-cell genomes identified putative viruses infecting marine thaumarchaeal and SUP05 proteobacteria to provide potential host linkages with relevance to coupled biogeochemical cycling processes in OMZ waters. Taken together, these results highlight the power of coupled analyses of multiple sequence data types, such as viral metagenomic and fosmid sequence data with prokaryotic single cell genomes, to chart viral diversity, elucidate genomic and ecological contexts for previously unclassifiable viral sequences, and identify novel host interactions in natural and engineered ecosystems. PMID:25914678

  20. Host Suitability of Potential Cover Crops for Root-knot Nematodes.

    PubMed

    McSorley, R

    1999-12-01

    Several potential cover crops were evaluated for their susceptibility to Meloidogyne arenaria race 1, M. incognita race 1, and M. javanica in a series of five greenhouse experiments. No galls or egg masses were observed on roots of castor (Ricinus communis), cowpea (Vigna unguiculata cv. Iron Clay), crotalaria (Crotalaria spectabilis), or American jointvetch (Aeschynomene americana). Occasional egg masses (rating hosts or non-hosts of the nematode isolates, including several legumes (cowpea, crotalaria, jointvetch, sunn hemp) that have potential use in both nematode and nitrogen management. PMID:19270926

  1. Host Suitability of Potential Cover Crops for Root-knot Nematodes

    PubMed Central

    McSorley, R.

    1999-01-01

    Several potential cover crops were evaluated for their susceptibility to Meloidogyne arenaria race 1, M. incognita race 1, and M. javanica in a series of five greenhouse experiments. No galls or egg masses were observed on roots of castor (Ricinus communis), cowpea (Vigna unguiculata cv. Iron Clay), crotalaria (Crotalaria spectabilis), or American jointvetch (Aeschynomene americana). Occasional egg masses (rating ≤1.0 on 0-5 scale) were observed on marigold (Tagetes minuta) in one test with M. incognita, on sesame (Sesamum indicum cv. Paloma) in a test with M. arenaria, and on sunn hemp (Crotalaria juncea cv. Tropic Sun) in 1 of 2 tests with M. incognita; otherwise, these crops were free of egg masses. Numbers of second-stage juveniles (J2) hatched from eggs per root system were low (≤10/pot) for the abovementioned crops. Egg-mass levels and numbers of hatched J2 of M. incognita on pearl millet (Pennisetum typhoides, Tifleaf II hybrid) were comparable to those on a susceptible tomato (Lycopersicon esculentum cv. Rutgers). In a test with M. arenaria, egg mass levels and numbers of J2 on Japanese millet (Echinochloa frumentacea) were similar to those on tomato. Japanese millet was susceptible to each of the nematode isolates tested. However, several of the crops evaluated were very poor hosts or non-hosts of the nematode isolates, including several legumes (cowpea, crotalaria, jointvetch, sunn hemp) that have potential use in both nematode and nitrogen management. PMID:19270926

  2. Toxoplasma gondii ROP18: potential to manipulate host cell mitochondrial apoptosis.

    PubMed

    Wu, Liang; Wang, Xiao; Li, Yunhui; Liu, Yuan; Su, Danhua; Fu, Tao; Guo, Fei; Gu, Liangping; Jiang, Xugan; Chen, Shengxia; Cao, Jianping

    2016-06-01

    Toxoplasma gondii is an obligate intracellular parasite that may manipulate host cell mitochondrial apoptosis pathways. In our experiment, 293T cells were transfected with the p3×FLAG-CMV-Myc-ROP18 vector and expressed the ROP18-Myc fusion protein. Cell apoptosis was induced by 0.5 μg/mL actinomycin D (ActD) and was detected by Annexin V-FITC/PI assay. The cell mitochondrial membrane potential was determined by JC-1. Cytochrome c (Cyto-c) from mitochondria and the cytoplasm was measured by Western blot. The Bcl-2 and Bax coding gene expression levels were detected by real-time PCR. We found, in vitro, that T. gondii ROP18 significantly suppressed 293T cell apoptosis induced by ActD and maintained mitochondrial membrane potential and integrity, thereby preventing the release of Cyto-c from mitochondria into the cytoplasm. The ratio of Bcl-2/Bax in ROP18-overexpressing cells was significantly higher than that of the negative control. Therefore, we speculate that ROP18 could suppress host cell apoptosis via the mitochondrial apoptosis pathway in vitro. PMID:27021182

  3. Potential Impacts of Leakage from Black Rock Reservoir on the Hanford Site Unconfined Aquifer: Initial Hypothetical Simulations of Flow and Contaminant Transport - Errata

    SciTech Connect

    Freedman, Vicky L.

    2007-04-30

    Errata for report documenting initial scoping calculations investigating the potential impacts on the Hanford unconfined aquifer resulting from leakage from the proposed Black Rock Reservoir to the west. These calculations were performed for the U.S. Bureau of Reclamation.

  4. Dingoes (Canis dingo Meyer, 1793) continue to be an important reservoir host of Dirofilaria immitis in low density housing areas in Australia.

    PubMed

    Smout, Felicity A; Skerratt, Lee F; Butler, James R A; Johnson, Christopher N; Congdon, Bradley C

    2016-01-15

    Heartworm (Dirofilaria immitis) is a parasitic nematode responsible for canine and feline cardiopulmonary dirofilariasis and human zoonotic filariosis in both tropical and temperate regions throughout the world. Importantly, this study in the Wet Tropics of Far North Queensland found D. immitis remains at high prevalence (72.7%) in wild dingoes in low density housing areas in Australia. This prevalence is equivalent to the highest levels seen in wild dogs in Australia and represents an ongoing risk to domestic dogs, cats and humans. In contrast, in higher density residential areas prevalence was significantly lower (16.7%, p=0.001). It is possible that chemotherapeutic heartworm (HW) prevention in domestic dogs in these higher density housing areas is helping to control infection in the resident dingo population. Five dingoes killed in council control operations around Atherton, a non-endemic HW region in the Wet Tropics, were all negative for HW likely due to the colder climate of the region restricting transmission of the disease. This survey highlights the importance of dingoes as reservoir hosts of HW disease and that the subsequent risk of infection to companion animals and humans depends on local factors such as housing density, possibly linked to chemotherapeutic HW control in domestic dogs and climate. Our findings show that veterinary clinicians need to ensure that pet owners are aware of HW disease and do not become complacent about HW chemoprohylaxis in areas which support dingo populations. PMID:26790730

  5. Stratigraphy and reservoir potential of glacial deposits of the Itarare Group (Carboniferous-Permian), Parana basin, Brazil

    SciTech Connect

    Franca, A.B. ); Potter, P.E. )

    1991-01-01

    Drilling in the Parana basin of Brazil in the mid-1980s discovered gas and condensate in the Itarare Group, and showed that glacial deposits in Brazil can contain hydrocarbons. The reservoir potential of the Carboniferous-Permian Itarare Group of the basin is analyzed using new subsurface data from 20 deep wells drilled in the early to middle 1980s. Central to the analysis was the construction of over 3000 km of cross sections based on more than 100 wells, the description of more than 400 m of core, and study of 95 thin sections. Subsurface exploration and mapping of the Itarare are greatly aided by the recognition of three recently defined and described formations and four members, which are traceable for hundreds of kilometers. These units belong to three major glacial cycles in which the pebbly mudstones and shales are seals and glacially related sandstones are reservoirs. The best sandstone reservoirs in the deep subsurface belong to the Rio Segredo Member, the upper-most sandy unit of the Itarare. The Rio Segredo Member is the best petroleum target because it is overlain by thick seals and massive pebbly mudstones and shales, and because it is shallower and less compacted than underlying, more deeply buried sandstones. This member has little detrital matrix and much of its porosity is secondary, developed by carboxylic acid and CO{sub 2} generated when Jurassic-Cretaceous basalts, sills, and dikes were intruded into the Parana basin as Gondwana broke up.

  6. Fundamental Host Range of Leptoypha hospita (Hemiptera: Tingidae), a Potential Biological Control Agent of Chinese Privet.

    PubMed

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

    2016-08-01

    Chinese privet, Ligustrum sinense Lour., is an invasive shrub within riparian areas of the southeastern United States. Biological control is considered the most suitable management option for Chinese privet. The potential host range of the lace bug, Leptoypha hospita Drake et Poor, was evaluated on the basis of adult feeding and oviposition, combined oviposition-nymphal development no-choice tests, nymphal development no-choice tests, multiple generation comparison on Forestiera pubescens Nutt. and L. sinense no-choice tests, and multiple-choice tests with 45 plant species in 13 families. No-choice tests showed that the host range of L. hospita was restricted to the tribe Oleeae. In adult feeding and oviposition no-choice tests, the bug fed and oviposited significantly more on Chinese privet than all other test plant species except for three native Forestiera spp., two nonnative Syringa spp., and another exotic Ligustrum sp. Among those, only F. pubescens supported complete development in numbers comparable to Chinese privet. However, when reared for multiple generations lace bugs reared on F. pubescens were smaller and had lower fecundity than those reared on L. sinense, suggesting F. pubescens is not an optimal host. In multiple-choice tests, L. hospita displayed a strong preference for feeding and ovipositing on Chinese privet over other test plant species, with the exception of the closely related nonnative Syringa spp. and its congenic species Ligustrum vulgare. The results of this study suggest that the risk to nontarget plant species in North America is minimal, and L. hospita would be a promising candidate for Chinese privet biological control. PMID:27325627

  7. Planktothrix Rubescens in Freshwater Reservoirs: The Sentinel-2 Potentiality for Mapping Phycocyanin Concentration

    NASA Astrophysics Data System (ADS)

    Maltese, Antonino; Capodici, Fulvio; Ciraolo, Giuseppe; Corbari, Chiara; Granata, Antonino; La Loggia, Goffredo

    2012-04-01

    In December 2006 blooms of Planktothrix rubescens were found in the Prizzi reservoir in Sicily. P. rubescens is sadly famous for producing microcystins (MC), which are harmful hepatotoxins. Recently (2006) P. rubescens has been found in the Pozzillo, Nicoletti, Ancipa, Prizzi and Garcia reservoirs. This paper compares the optical properties of the water of an infested reservoir and those of a clear water reservoir. Furthermore it evaluates an empirical method based on bands product to evaluate the phycocyanin cell density from MODIS, Landsat ETM+ and Sentinel-2 images. Spectroradiometric field campaigns were carried out in February/March 2008 to quantify the spectral transparencies of two water bodies through the calculation of the diffuse attenuation coefficient, by measuring underwater downwelling irradiance at different depths as well as water spectral reflectance. The possibility of detecting P. rubescens using its spectral characteristics through diachronic remote sensing techniques was investigated. During periods of low shortwave irradiance such as winter, when light weakly penetrates water columns and the water cools, P. rubescens filaments float up to the surface, forming red-colored blooms. Analyses were carried out on two reservoirs: Lake Prizzi and Lake Trinità, with and without the P. rubescens algal bloom respectively, during the acquisition of field data. Water samples were collected for both phytoplankton counting and biovolume estimation and for the analysis of MC. Meteorological measurements highlighted the low temperatures (< 2° C) for this region, which occurred between two frosts in December 2007 and February 2008, with a contemporaneous reduction in the incident total solar radiation that probably triggered P. rubescens to float up to the water surface in the infested lake. Underwater spectral irradiances and in-air upwelling spectral radiances were acquired in February/March 2007 in order to characterize the extinction optical properties of

  8. Domestic pigs as potential reservoirs of human and animal trypanosomiasis in Northern Tanzania

    PubMed Central

    2013-01-01

    Background Pig keeping is becoming increasingly common across sub-Saharan Africa. Domestic pigs from the Arusha region of northern Tanzania were screened for trypanosomes using PCR-based methods to examine the role of pigs as a reservoir of human and animal trypanosomiasis. Methods A total of 168 blood samples were obtained from domestic pigs opportunistically sampled across four districts in Tanzania (Babati, Mbulu, Arumeru and Dodoma) during December 2004. A suite of PCR-based methods was used to identify the species and sub-species of trypanosomes including: Internally Transcribed Sequence to identify multiple species; species specific PCR to identify T. brucei s. l. and T. godfreyi and a multiplex PCR reaction to distinguish T. b. rhodesiense from T. brucei s. l. Results Of the 168 domestic pigs screened for animal and human infective trypanosome DNA, 28 (16.7%) were infected with one or more species of trypanosome; these included: six pigs infected with Trypanosoma vivax (3.6%); three with Trypanosoma simiae (1.8%); two with Trypanosoma congolense (Forest) (1%) and four with Trypanosoma godfreyi (2.4%). Nineteen pigs were infected with Trypanosoma brucei s. l. (10.1%) of which eight were identified as carrying the human infective sub-species Trypanosoma brucei rhodesiense (4.8%). Conclusion These results show that in Tanzania domestic pigs may act as a significant reservoir for animal trypanosomiasis including the cattle pathogens T. vivax and T. congolense, the pig pathogen T. simiae, and provide a significant reservoir for T. b. rhodesiense, the causative agent of acute Rhodesian sleeping sickness. PMID:24499540

  9. Lactococcus lactis M4, a potential host for the expression of heterologous proteins

    PubMed Central

    2011-01-01

    Background Many plasmid-harbouring strains of Lactococcus lactis have been isolated from milk and other sources. Plasmids of Lactococcus have been shown to harbour antibiotic resistance genes and those that express some important proteins. The generally regarded as safe (GRAS) status of L. lactis also makes it an attractive host for the production of proteins that are beneficial in numerous applications such as the production of biopharmaceutical and nutraceutical. In the present work, strains of L. lactis were isolated from cow's milk, plasmids were isolated and characterised and one of the strains was identified as a potential new lactococcal host for the expression of heterologous proteins. Results Several bacterial strains were isolated from cow's milk and eight of those were identified as Lactococcus lactis by 16S rRNA sequence analysis. Antibiotic susceptibility tests that were carried out showed that 50% of the isolates had almost identical antibiotic resistance patterns compared to the control strains MG1363 and ATCC 11454. Plasmid profiling results indicated the lack of low molecular weight plasmids for strain M4. Competent L. lactis M4 and MG1363 were prepared and electrotransformed with several lactococcal plasmids such as pMG36e, pAR1411, pAJ01 and pMG36e-GFP. Plasmid isolation and RE analyses showed the presence of these plasmids in both M4 and the control strain after several generations, indicating the ability of M4 to maintain heterologous plasmids. SDS-PAGE and Western blot analyses also confirmed the presence of GFP, demonstrating the potential of heterologous protein expression in M4. Conclusions Based on the 16S rRNA gene molecular analysis, eight Gram-positive cocci milk isolates were identified as L. lactis subsp. lactis. One of the strains, L. lactis M4 was able to maintain transformed low molecular weight plasmid vectors and expressed the GFP gene. This strain has the potential to be developed into a new lactococcal host for the expression

  10. Silurian "Clinton" Sandstone Reservoir Characterization for Evaluation of CO2-EOR Potential in the East Canton Oil Field, Ohio

    SciTech Connect

    Riley, Ronald; Wicks, John; Perry, Christopher

    2009-12-30

    The purpose of this study was to evaluate the efficacy of using CO2-enhanced oil recovery (EOR) in the East Canton oil field (ECOF). Discovered in 1947, the ECOF in northeastern Ohio has produced approximately 95 million barrels (MMbbl) of oil from the Silurian “Clinton” sandstone. The original oil-in-place (OOIP) for this field was approximately 1.5 billion bbl and this study estimates by modeling known reservoir parameters, that between 76 and 279 MMbbl of additional oil could be produced through secondary recovery in this field, depending on the fluid and formation response to CO2 injection. A CO2 cyclic test (“Huff-n-Puff”) was conducted on a well in Stark County to test the injectivity in a “Clinton”-producing oil well in the ECOF and estimate the dispersion or potential breakthrough of the CO2 to surrounding wells. Eighty-one tons of CO2 (1.39 MMCF) were injected over a 20-hour period, after which the well was shut in for a 32-day “soak” period before production was resumed. Results demonstrated injection rates of 1.67 MMCF of gas per day, which was much higher than anticipated and no CO2 was detected in gas samples taken from eight immediately offsetting observation wells. All data collected during this test was analyzed, interpreted, and incorporated into the reservoir characterization study and used to develop the geologic model. The geologic model was used as input into a reservoir simulation performed by Fekete Associates, Inc., to estimate the behavior of reservoir fluids when large quantities of CO2 are injected into the “Clinton” sandstone. Results strongly suggest that the majority of the injected CO2 entered the matrix porosity of the reservoir pay zones, where it diffused into the oil. Evidence includes: (A) the volume of injected CO2 greatly exceeded the estimated capacity of the hydraulic fracture and natural fractures; (B) there was a gradual injection and pressure rate build-up during the test; (C) there was a subsequent

  11. Silurian "Clinton" Sandstone Reservoir Characterization for Evaluation of CO2-EOR Potential in the East Canton Oil Field, Ohio

    SciTech Connect

    Ronald Riley; John Wicks; Christopher Perry

    2009-12-30

    The purpose of this study was to evaluate the efficacy of using CO2-enhanced oil recovery (EOR) in the East Canton oil field (ECOF). Discovered in 1947, the ECOF in northeastern Ohio has produced approximately 95 million barrels (MMbbl) of oil from the Silurian 'Clinton' sandstone. The original oil-in-place (OOIP) for this field was approximately 1.5 billion bbl and this study estimates by modeling known reservoir parameters, that between 76 and 279 MMbbl of additional oil could be produced through secondary recovery in this field, depending on the fluid and formation response to CO2 injection. A CO2 cyclic test ('Huff-n-Puff') was conducted on a well in Stark County to test the injectivity in a 'Clinton'-producing oil well in the ECOF and estimate the dispersion or potential breakthrough of the CO2 to surrounding wells. Eighty-one tons of CO2 (1.39 MMCF) were injected over a 20-hour period, after which the well was shut in for a 32-day 'soak' period before production was resumed. Results demonstrated injection rates of 1.67 MMCF of gas per day, which was much higher than anticipated and no CO2 was detected in gas samples taken from eight immediately offsetting observation wells. All data collected during this test was analyzed, interpreted, and incorporated into the reservoir characterization study and used to develop the geologic model. The geologic model was used as input into a reservoir simulation performed by Fekete Associates, Inc., to estimate the behavior of reservoir fluids when large quantities of CO2 are injected into the 'Clinton' sandstone. Results strongly suggest that the majority of the injected CO2 entered the matrix porosity of the reservoir pay zones, where it diffused into the oil. Evidence includes: (A) the volume of injected CO2 greatly exceeded the estimated capacity of the hydraulic fracture and natural fractures; (B) there was a gradual injection and pressure rate build-up during the test; (C) there was a subsequent, gradual flashout of

  12. Effect of salt tectonics on potential CO2 reservoir and caprock in the Norwegian-Danish basin.

    NASA Astrophysics Data System (ADS)

    Sassier, C.; Faleide, J. I.; Aagaard, P.; Gabrielsen, R. H.

    2012-04-01

    Salt tectonics can provide closure structure for accumulation of oil or gas. Thus, it can also provide proper closure structures for CO2 storage. In contrast to oil and gas accumulation where the sealing is evident, however, these potential closure structures, including reservoir and caprock, and the associated faults have to be carefully evaluated for CO2 storage. In the North Sea, previous screening for CO2 storage plays identified potential Triassic and Jurassic reservoirs, in particular in the Upper Triassic Gassum Formation. In the Norwegian-Danish basin located in the southern part of the North Sea, Permian salt occurs widely and is at the origin of intense salt tectonics. There, salt plugs and walls deformed and pierced the overburden sediments between Triassic or Jurassic times until the Early Miocene according to previous studies. In order to evaluate the potential closure structures over salt plugs in the Norwegian-Danish basin for CO2 storage purpose, we investigate the initiation, movement and duration of the salt tectonics, its effects on the Gassum formation and its overburden caprock through detailed seismic mapping and structural analysis. In this contribution, we will present the preliminary results of this study.

  13. Bacterial porin disrupts mitochondrial membrane potential and sensitizes host cells to apoptosis.

    PubMed

    Kozjak-Pavlovic, Vera; Dian-Lothrop, Elke A; Meinecke, Michael; Kepp, Oliver; Ross, Katharina; Rajalingam, Krishnaraj; Harsman, Anke; Hauf, Eva; Brinkmann, Volker; Günther, Dirk; Herrmann, Ines; Hurwitz, Robert; Rassow, Joachim; Wagner, Richard; Rudel, Thomas

    2009-10-01

    The bacterial PorB porin, an ATP-binding beta-barrel protein of pathogenic Neisseria gonorrhoeae, triggers host cell apoptosis by an unknown mechanism. PorB is targeted to and imported by host cell mitochondria, causing the breakdown of the mitochondrial membrane potential (DeltaPsi(m)). Here, we show that PorB induces the condensation of the mitochondrial matrix and the loss of cristae structures, sensitizing cells to the induction of apoptosis via signaling pathways activated by BH3-only proteins. PorB is imported into mitochondria through the general translocase TOM but, unexpectedly, is not recognized by the SAM sorting machinery, usually required for the assembly of beta-barrel proteins in the mitochondrial outer membrane. PorB integrates into the mitochondrial inner membrane, leading to the breakdown of DeltaPsi(m). The PorB channel is regulated by nucleotides and an isogenic PorB mutant defective in ATP-binding failed to induce DeltaPsi(m) loss and apoptosis, demonstrating that dissipation of DeltaPsi(m) is a requirement for cell death caused by neisserial infection. PMID:19851451

  14. Experimental oral inoculations in birds to evaluate potential definitive hosts of Neospora caninum.

    PubMed

    Baker, D G; Morishita, T Y; Brooks, D L; Shen, S K; Lindsay, D S; Dubey, J P

    1995-10-01

    Experimental oral inoculations to evaluate potential definitive hosts of Neospora caninum were conducted by feeding infected rodent tissues to 9 carnivorous birds of 4 species. Birds included 2 red-tailed hawks (Buteo jamaicensis), 2 turkey vultures (Cathartes aura), 2 barn owls (Tyto alba), and 3 American crows (Corvus brachyrhynchus). The rodents (mice or rats) had been inoculated with 100,000 culture-derived tachyzoites of N. caninum 1-6 mo before feeding to the birds. Fecal samples were collected from each bird daily for 1 mo after feeding rodents and examined for oocysts by fecal flotation. In addition, processed aliquots from all avian fecal samples were fed to BALB/c mice. Five weeks after feeding, mice were bled and sera were tested for antibodies against N. caninum. One to two months later, mice were killed and brain tissue was examined microscopically for protozoal cysts. While occasional oocysts were found in avian fecal samples, these were likely not N. caninum because they were not infective to BALB/c mice. It was concluded that the bird species tested are not likely to be definitive hosts of N. caninum. PMID:7472875

  15. Current and Potential Applications of Host-Defense Peptides and Proteins in Urology

    PubMed Central

    2015-01-01

    The use of antibiotics has become increasingly disfavored as more multidrug resistant pathogens are on the rise. A promising alternative to the use of these conventional drugs includes antimicrobial peptides or host-defense peptides. These peptides typically consist of short amino acid chains with a net cationic charge and a substantial portion of hydrophobic residues. They mainly target the bacterial cell membrane but are also capable of translocating through the membrane and target intracellular components, making it difficult for bacteria to gain resistance as multiple essential cellular processes are being targeted. The use of these peptides in the field of biomedical therapies has been examined, and the different approaches to using them under various settings are constantly being discovered. In this review, we discuss the current and potential applications of these host-defense peptides in the field of urology. Besides the use of these peptides as antimicrobial agents, the value of these biological molecules has recently been expanded to their use as antitumor and anti-kidney-stone agents. PMID:25815308

  16. Observations on bilharziasis and the potential snail hosts in the Republic of the Congo (Brazzaville)

    PubMed Central

    McCullough, Fergus S.

    1964-01-01

    In 1962, the author conducted a preliminary investigation of bilharziasis in the Republic of the Congo (Brazzaville), at the request of the Government, in order to review existing information and work done on bilharziasis, to assess the prevalence and distribution of the disease, to make observations on the potential snail hosts, and to propose further suitable studies and control measures. Although little time was available for this study, it appears reasonable to conclude that Schistosoma haematobium is confined to a few foci in the west of the country, the main snail host being a new subspecies of Bulinus (B.) truncatus. Intestinal bilharziasis is apparently very rare, but systematic stool surveys have not been done; S. mansoni may be, or become, endemic at Dolisie, where Biomphalaria camerunensis is abundant. The main factors governing the restricted distribution of bilharziasis are discussed. Bilharziasis control appears to merit relatively low priority compared with that due to several other diseases, and the author concludes that bilharziasis is unlikely to become widespread in future years unless there is major environmental change, although the intensity of transmission may increase in some present endemic foci. PMID:14163961

  17. In-situ stress and fracture permeability in a fault-hosted geothermal reservoir at Dixie Valley, Nevada

    USGS Publications Warehouse

    Hickman, Stephen; Barton, Colleen; Zoback, Mark; Morin, Roger; Sass, John; Benoit, Richard

    1997-01-01

    As part of a study relating fractured rock hydrology to in-situ stress and recent deformation within the Dixie Valley Geothermal Field, borehole televiewer logging and hydraulic fracturing stress measurements were conducted in a 2.7-km-deep geothermal production well (73B-7) drilled into the Stillwater fault zone. Borehole televiewer logs from well 73B-7 show numerous drilling-induced tensile fractures, indicating that the direction of the minimum horizontal principal stress, Shmin, is S57 ??E. As the Stillwater fault at this location dips S50 ??E at approximately 3??, it is nearly at the optimal orientation for normal faulting in the current stress field. Analysis of the hydraulic fracturing data shows that the magnitude of Shmin is 24.1 and 25.9 MPa at 1.7 and 2.5 km, respectively. In addition, analysis of a hydraulic fracturing test from a shallow well 1.5 km northeast of 73B-7 indicates that the magnitude of Shmin is 5.6 MPa at 0.4 km depth. Coulomb failure analysis shows that the magnitude of Shmin in these wells is close to that predicted for incipient normal faulting on the Stillwater and subparallel faults, using coefficients of friction of 0.6-1.0 and estimates of the in-situ fluid pressure and overburden stress. Spinner flowmeter and temperature logs were also acquired in well 73B-7 and were used to identify hydraulically conductive fractures. Comparison of these stress and hydrologic data with fracture orientations from the televiewer log indicates that hydraulically conductive fractures within and adjacent to the Stillwater fault zone are critically stressed, potentially active normal faults in the current west-northwest extensional stress regime at Dixie Valley.

  18. Interpolation of bottom bathymetry and potential erosion in a large Tennessee reservoir system using GRASS

    SciTech Connect

    Hargrove, W.W.; Hoffman, F.M.; Levine, D.A.

    1995-12-31

    A regularized spline with tension was used to interpolate a bathymetric bottom surface for the Watts Bar reservoir just south of Oak Ridge, TN as part of an effort to predict the spatial distribution of radionuclide contaminants. Cesium 137 was released as a by-product of the production of fissionable materials during the mid-1950s. Cesium is strongly adsorbed onto clay and silt particles in the water column, and tends to settle to the bottom. An understanding of the shape and contours of the bottom is important for understanding and prediction of the location and extent of contaminated sediments. The results of the investigations are available on the World Wide Web (WWW) at URL: http://www.esd.ornl.gov/programs/CRERP/INDEX.HTM. The Waterways Experiment Station (WES) of the US Army Corps of Engineers conducted a hydro-acoustic study of the Clinch River arm of Watts Bar Reservoir to determine the distribution, thickness, and type of bottom sediments that had accumulated since completion of Watts Bar Dam in 1942. WES has developed a rapid geophysical technique to determine material characteristics of bottom and subbottom sediments. Acoustic impedance values determined from seismic reflection data are directly related to the density and material type of the subbottom sediments. The objective was to quantify with depth the density and type of bottom and subbottom sediments up to depths of 15 ft below the bottom surface along the Clinch River and Poplar Creek, TN.

  19. Facies, faults and potential sweet spots in a tight gas reservoir: Almond Formation, Wyoming

    SciTech Connect

    Martinsen, R.; Iverson, W.; Surdam, R.

    1996-12-31

    The Almond Formation is a major producer of gas in southwestern Wyoming. Although exploration generally is aimed at finding conventional reservoirs in upper Almond marine sandstones, the majority of Almond gas is contained in the underlying main Almond, a succession of dominantly non-marine, interbedded tight sandstones, siltstones, carbonaceous shales and coals. Production data indicate that some of the best gas wells completed in upper Almond sands show little production decline and have already produced more gas than calculations indicate they contain. This implies that these wells have somehow successfully tapped into the vast supply of gas contained in the main Almond. We believe that the more permeable reservoirs, in addition to providing {open_quotes}sweet spots{close_quotes} for exploration, also serve as lateral conduits capable of draining gas over a broad area from the main Almond. The {open_quotes}sweet spots{close_quotes} themselves do not need to be volumetrically large, only permeable and laterally continuous. Previously unrecognized marine sands, similar to those in the upper Almond, are favorably located in the middle of the main Almond succession and may provide additional lateral conduits. Studies also show that syndepositional faults significantly influenced deposition and may also be important in terms of fluid flow. At least some syndepositional faults are associated with anomalously high gas and/or water production within fields, and may be vertical conduits for fluid flow.

  20. Facies, faults and potential sweet spots in a tight gas reservoir: Almond Formation, Wyoming

    SciTech Connect

    Martinsen, R.; Iverson, W.; Surdam, R. )

    1996-01-01

    The Almond Formation is a major producer of gas in southwestern Wyoming. Although exploration generally is aimed at finding conventional reservoirs in upper Almond marine sandstones, the majority of Almond gas is contained in the underlying main Almond, a succession of dominantly non-marine, interbedded tight sandstones, siltstones, carbonaceous shales and coals. Production data indicate that some of the best gas wells completed in upper Almond sands show little production decline and have already produced more gas than calculations indicate they contain. This implies that these wells have somehow successfully tapped into the vast supply of gas contained in the main Almond. We believe that the more permeable reservoirs, in addition to providing [open quotes]sweet spots[close quotes] for exploration, also serve as lateral conduits capable of draining gas over a broad area from the main Almond. The [open quotes]sweet spots[close quotes] themselves do not need to be volumetrically large, only permeable and laterally continuous. Previously unrecognized marine sands, similar to those in the upper Almond, are favorably located in the middle of the main Almond succession and may provide additional lateral conduits. Studies also show that syndepositional faults significantly influenced deposition and may also be important in terms of fluid flow. At least some syndepositional faults are associated with anomalously high gas and/or water production within fields, and may be vertical conduits for fluid flow.

  1. Analysis of pulsed field gel electrophoresis profiles using multiple enzymes for predicting potential source reservoirs for strains of Salmonella Enteritidis and Salmonella Typhimurium isolated from humans.

    PubMed

    Son, Insook; Zheng, Jie; Keys, Christine E; Zhao, Shaohua; Meng, Jianghong; Brown, Eric W

    2013-06-01

    We reported previously on a highly discriminatory pulsed field gel electrophoresis-based (PFGE) subtyping scheme for Salmonella enterica serovar Enteritidis (SE) and Salmonella Typhimurium (ST) that relies on combined cluster analysis of up to six restriction enzymes. This approach allowed for the high-resolution separation of numerous poultry-derived SE and ST isolates into several distinct clusters that sorted along several geographical and host-linked boundaries. In this study, 101 SE and 151 ST strains isolated from poultry, swine, beef, mouse, and produce origins were combined with 62 human SE and ST isolates of unknown sources. PFGE profiles were generated across six restriction enzymes (XbaI, BlnI, SpeI, SfiI, PacI, and NotI) for human SE and ST isolates. The combined six-enzyme UPGMA trees of SE and ST revealed six separate origins of North American human SE isolates including one association with a "cosmopolitan" cluster of SEs from poultry originating in Scotland, Mexico, and China. In the case of ST, human isolates assorted readily along host lines rather than geographical partitions with the majority of human STs clustering in a larger group of STs of potential porcine origin. Such observations may underscore the ecological importance of poultry and pork reservoirs for SE and ST transmission to humans, respectively. In an examination of the relationship between enzyme diversity and congruence among enzymes, pairwise genetic diversity ranged from 6.5% to 9.7% for SE isolates and, more widely, from 17.5% to 27.4% for ST isolates. Phylogenetic congruence measures singled out XbaI, BlnI, and SfiI as most concordant for SE while XbaI and SfiI were most concordant among ST strains. Thus, these data provide the first proof of principal for concatenated PFGE, when coupled with sufficient enzyme numbers and combinations, as one effective means for predicting geographical and food source reservoirs for human isolates of these two highly prevalent Salmonella

  2. Presence of avian influenza viruses in waterfowl and wetlands during summer 2010 in California: Are resident birds a potential reservoir?

    USGS Publications Warehouse

    Henaux, V.; Samuel, M.D.; Dusek, R.J.; Fleskes, J.P.; Ip, H.S.

    2012-01-01

    Although wild waterfowl are the main reservoir for low pathogenic avian influenza viruses (LPAIv), the environment plays a critical role for the circulation and persistence of AIv. LPAIv may persist for extended periods in cold environments, suggesting that waterfowl breeding areas in the northern hemisphere may be an important reservoir for AIv in contrast to the warmer southern wintering areas. We evaluated whether southern wetlands, with relatively small populations (thousands) of resident waterfowl, maintain AIv in the summer, prior to the arrival of millions of migratory birds. We collected water and fecal samples at ten wetlands in two regions (Yolo Bypass and Sacramento Valley) of the California Central Valley during three bi-weekly intervals beginning in late July, 2010. We detected AIv in 29/367 fecal samples (7.9%) and 12/597 water samples (2.0%) by matrix real time Reverse Transcription Polymerase Chain Reaction (rRT-PCR). We isolated two H3N8, two H2N3, and one H4N8 among rRT-PCR positive fecal samples but no live virus from water samples. Detection of AIv RNA in fecal samples was higher from wetlands in the Sacramento Valley (11.9%) than in the Yolo Bypass (0.0%), but no difference was found for water samples (2.7 vs. 1.7%, respectively). Our study showed that low densities of hosts and unfavorable environmental conditions did not prevent LPAIv circulation during summer in California wetlands. Our findings justify further investigations to understand AIv dynamics in resident waterfowl populations, compare AIv subtypes between migratory and resident waterfowl, and assess the importance of local AIv as a source of infection for migratory birds.

  3. Effects of mineral composition and pore structure in HC potential of reservoir rocks in the Western Foothill Belt, Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, J. M.; Tsai, L. Y.

    2014-12-01

    The exploration of unconventional gas resource achieved a successful breakthrough in USA due to the innovation of hydraulic fracturing and horizontal drilling since 1995. The production of shale gas dramatically changed the energy structure and released the demand of fossil fuel in USA. Many studies about the unconventional oil-gas resource were performed worldwide especially in China, which provide very useful characterization for unconventional gas reservoirs. Since Taiwan has a strong energy demand and still highly relied on imported fossil fuel, the development of unconventional gas resource needs to be concerned. Therefore, the objective of this study is to evaluate the potential of unconventional oil-gas in Taiwan. In this study, we examine mineral composition and pore structure of Miocene oil-gas bearing strata from the Western Foothill Belt in Taiwan. Sandstone samples were collected from Cholan Fm, Yutengpin ss, Kuantaoshan ss, Shangfuchi ss, Tungkeng Fm, Guanyinshang ss and Peiliao Fm; whereas shale samples were collected from Chinshui sh and Talu sh, as well as outcropped coal sample from Nanchung Fm. The porosity, permeability, TOC, thermal maturity, and mineral composition of samples are examined after a series of geochemical experiments. Finally, after comparing the data with their gas sorption capacity, the reservoir with the strongest potential in unconventional gas resource can be identified.

  4. Fines migration, blocking, and clay swelling of potential geothermal sandstone reservoirs, Denmark

    SciTech Connect

    Priisholm, S.; Nielson, B.L.; Haslund, O.

    1987-06-01

    Medium-grained, moderately well-sorted sandstones of fluvio-deltaic to shallow marine origin have been investigated for fines production and for variations in porosity/permeability. Porosity and permeability change within small horizontal and vertical changes in sampling points. Also, air permeability depends on flow direction, Klinkenberg correction, and cleaning procedure. Klinkenberg-corrected permeability and brine permeability were found not to be comparable. Brine flow cause flines of kaolinite and quartz to be produced from the compacted sandstones, while uncompacted sandstones produced kaolinite, illite, and detrital minerals. Chlorites and mixed-layer clays were not produced as fines, although they were present in some samples. Reservoir damage occurred when formation brine was replaced by KCl-brine, at increase in flow velocity, and at pauses in flow. Changes in flow direction caused severe fines production, renewed bridging, and blocking by fines.

  5. Blue crabs Callinectes sapidus as potential biological reservoirs for white spot syndrome virus (WSSV).

    PubMed

    Powell, James W B; Browdy, Craig L; Burge, Erin J

    2015-03-01

    White spot syndrome virus (WSSV) is a virulent pathogen of cultured shrimp and was first detected in farms in South Carolina (USA) in 1997 and subsequently in wild shrimp in 1999. We screened groups of 1808 wild Atlantic white shrimp Litopenaeus setiferus and 300 blue crabs Callinectes sapidus collected from South Carolina, Georgia, and Florida for the presence of WSSV using the Shrimple® immunoassay-strip test, with all positives and random subsets of negatives tested by TaqMan real-time PCR and in infectivity bioassays. Of 87 shrimp and 11 crabs that tested positive using the Shrimple® test, only a single C. sapidus was confirmed to be infected with WSSV by PCR and the infectivity bioassay. The data indicate that the prevalence of WSSV in these species is low in these southeastern US regions, but that C. sapidus may serve as a biological reservoir. PMID:25751859

  6. Enemies and turncoats: bovine tuberculosis exposes pathogenic potential of Rift Valley fever virus in a common host, African buffalo (Syncerus caffer).

    PubMed

    Beechler, B R; Manore, C A; Reininghaus, B; O'Neal, D; Gorsich, E E; Ezenwa, V O; Jolles, A E

    2015-04-22

    The ubiquity and importance of parasite co-infections in populations of free-living animals is beginning to be recognized, but few studies have demonstrated differential fitness effects of single infection versus co-infection in free-living populations. We investigated interactions between the emerging bacterial disease bovine tuberculosis (BTB) and the previously existing viral disease Rift Valley fever (RVF) in a competent reservoir host, African buffalo, combining data from a natural outbreak of RVF in captive buffalo at a buffalo breeding facility in 2008 with data collected from a neighbouring free-living herd of African buffalo in Kruger National Park. RVF infection was twice as likely in individual BTB+ buffalo as in BTB- buffalo, which, according to a mathematical model, may increase RVF outbreak size at the population level. In addition, co-infection was associated with a far higher rate of fetal abortion than other infection states. Immune interactions between BTB and RVF may underlie both of these interactions, since animals with BTB had decreased innate immunity and increased pro-inflammatory immune responses. This study is one of the first to demonstrate how the consequences of emerging infections extend beyond direct effects on host health, potentially altering the dynamics and fitness effects of infectious diseases that had previously existed in the ecosystem on free-ranging wildlife populations. PMID:25788592

  7. Molecular identification of host feeding patterns of snow-melt mosquitoes (Diptera: Culicidae): potential implications for the transmission ecology of Jamestown Canyon virus.

    PubMed

    Murdock, C C; Olival, Kevin J; Perkins, Susan L

    2010-03-01

    We collected blood-fed, snow-melt mosquitoes (Culicidae: Culiseta and Aedes) to describe the feeding patterns of potential mosquito vectors of Jamestown Canyon virus (JCV, Bunyaviridae: Orthobunyavirus). JCV is an arthropod-borne, zoonotic virus with deer as the primary amplifying host in western alpine ecosystems. We collected mosquitoes from natural resting areas, fiber pots, and carbon-dioxide baited miniature light traps in the Colorado Rocky Mountains in 2007. We conducted two polymerase chain reactions to amplify and sequence vertebrate DNA extracted from blood-fed mosquitoes, which yielded comparable, but not identical, results. Mammal-specific primers found mule deer (Odocoileus hemionus) and elk (Cervus elaphus canadensis) as the source of all bloodmeals. To determine if unamplified bloodmeals were from nonmammalian sources, we screened all samples with conserved vertebrate primers, which confirmed the initial polymerase chain reaction results, but also found porcupine (Erethizon dorsatum) and human (Homo sapiens) as additional bloodmeal sources. We consistently found that mule deer were the primary hosts for mosquitoes in this system. These results suggest that snow-melt mosquitoes, in particular A. cataphylla, may be important vectors in western JCV alpine systems and may also act as a bridge vector for JCV from cervid virus reservoirs to humans. PMID:20380304

  8. Enemies and turncoats: bovine tuberculosis exposes pathogenic potential of Rift Valley fever virus in a common host, African buffalo (Syncerus caffer)

    PubMed Central

    Beechler, B. R.; Manore, C. A.; Reininghaus, B.; O'Neal, D.; Gorsich, E. E.; Ezenwa, V. O.; Jolles, A. E.

    2015-01-01

    The ubiquity and importance of parasite co-infections in populations of free-living animals is beginning to be recognized, but few studies have demonstrated differential fitness effects of single infection versus co-infection in free-living populations. We investigated interactions between the emerging bacterial disease bovine tuberculosis (BTB) and the previously existing viral disease Rift Valley fever (RVF) in a competent reservoir host, African buffalo, combining data from a natural outbreak of RVF in captive buffalo at a buffalo breeding facility in 2008 with data collected from a neighbouring free-living herd of African buffalo in Kruger National Park. RVF infection was twice as likely in individual BTB+ buffalo as in BTB− buffalo, which, according to a mathematical model, may increase RVF outbreak size at the population level. In addition, co-infection was associated with a far higher rate of fetal abortion than other infection states. Immune interactions between BTB and RVF may underlie both of these interactions, since animals with BTB had decreased innate immunity and increased pro-inflammatory immune responses. This study is one of the first to demonstrate how the consequences of emerging infections extend beyond direct effects on host health, potentially altering the dynamics and fitness effects of infectious diseases that had previously existed in the ecosystem on free-ranging wildlife populations. PMID:25788592

  9. A review on multicomponent seismology: A potential seismic application for reservoir characterization

    PubMed Central

    Farfour, Mohammed; Yoon, Wang Jung

    2015-01-01

    Searching for hydrocarbon reserves in deep subsurface is the main concern of wide community of geophysicists and geoscientists in petroleum industry. Exploration seismology has substantially contributed to finding and developing giant fields worldwide. The technology has evolved from two to three-dimensional method, and later added a fourth dimension for reservoir monitoring. Continuous depletion of many old fields and the increasing world consumption of crude oil pushed to consistently search for techniques that help recover more reserves from old fields and find alternative fields in more complex and deeper formations either on land and in offshore. In such environments, conventional seismic with the compressional (P) wave alone proved to be insufficient. Multicomponent seismology came as a solution to most limitations encountered in P-wave imaging. That is, recording different components of the seismic wave field allowed geophysicists to map complex reservoirs and extract information that could not be extracted previously. The technology demonstrated its value in many fields and gained popularity in basins worldwide. In this review study, we give an overview about multicomponent seismology, its history, data acquisition, processing and interpretation as well as the state-of the-art of its applications. Recent examples from world basins are highlighted. The study concludes that despite the success achieved in many geographical areas such as deep offshore in the Gulf of Mexico, Western Canada Sedimentary Basin (WCSB), North Sea, Offshore Brazil, China and Australia, much work remains for the technology to gain similar acceptance in other areas such as Middle East, East Asia, West Africa and North Africa. However, with the tremendous advances reported in data recording, processing and interpretation, the situation may change. PMID:27222756

  10. A review on multicomponent seismology: A potential seismic application for reservoir characterization.

    PubMed

    Farfour, Mohammed; Yoon, Wang Jung

    2016-05-01

    Searching for hydrocarbon reserves in deep subsurface is the main concern of wide community of geophysicists and geoscientists in petroleum industry. Exploration seismology has substantially contributed to finding and developing giant fields worldwide. The technology has evolved from two to three-dimensional method, and later added a fourth dimension for reservoir monitoring. Continuous depletion of many old fields and the increasing world consumption of crude oil pushed to consistently search for techniques that help recover more reserves from old fields and find alternative fields in more complex and deeper formations either on land and in offshore. In such environments, conventional seismic with the compressional (P) wave alone proved to be insufficient. Multicomponent seismology came as a solution to most limitations encountered in P-wave imaging. That is, recording different components of the seismic wave field allowed geophysicists to map complex reservoirs and extract information that could not be extracted previously. The technology demonstrated its value in many fields and gained popularity in basins worldwide. In this review study, we give an overview about multicomponent seismology, its history, data acquisition, processing and interpretation as well as the state-of the-art of its applications. Recent examples from world basins are highlighted. The study concludes that despite the success achieved in many geographical areas such as deep offshore in the Gulf of Mexico, Western Canada Sedimentary Basin (WCSB), North Sea, Offshore Brazil, China and Australia, much work remains for the technology to gain similar acceptance in other areas such as Middle East, East Asia, West Africa and North Africa. However, with the tremendous advances reported in data recording, processing and interpretation, the situation may change. PMID:27222756

  11. New Hosts for Equine Herpesvirus 9

    PubMed Central

    Tucker, Tammy A.; Donovan, Taryn A.; Busch, Martin D.M.; Wise, Annabel G.; Maes, Roger K.; Kiupel, Matti

    2008-01-01

    Equine herpesvirus 9 was detected in a polar bear with progressive encephalitis; the source was traced to 2 members of a potential equid reservoir species, Grevy’s zebras. The virus was also found in an aborted Persian onager. Thus, the natural host range is extended to 6 species in 3 mammalian orders. PMID:18826828

  12. Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity

    PubMed Central

    Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

    2011-01-01

    Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of

  13. Integration of photomosaics and stratigraphy in the Western Appalachian Basin as an aid to identify potential hydrocarbon reservoirs

    SciTech Connect

    Wegweiser, M.D.

    1996-09-01

    Paleozoic stratigraphy of the southern Lake Erie region is commonly interpreted as being dominated by flat-lying sedimentary rocks. Recent surface stratigraphic studies in New York, Pennsylvania, and Ohio have revealed the widespread presence of NW- and NE-trending folds and faults exposed along stream beds, and in bluffs along the southern Lake Erie shoreline. A black shale unit, previously unknown in northwestern Pennsylvania, was also discovered and its lateral continuity mapped. The shale forms a disconformable contact with the overlying Northeast Shale. Ship-based photomosaics were made of bluffs along Lake Erie, and integrated with land-based stratigraphic sections to map the continuity of units, identify displacement zones, and identify low amplitude folds. The black shale unit aided identification of offset and folding. Faults observed at the surface off-set Devonian and Mississippian rocks, and unconsolidated Quaternary sediments. Subsurface wrench faults, apparently extending into Precambrian rocks, have been identified by others. These wrench faults are generally perpendicular to the strike of the Appalachian Mountains, and are known as cross-strike discontinuities (CSDs). Principle zones of displacement associated with the CSDs can be recognized at the surface by numerous fractures having little offset, aligned drainage systems, and zones of increased hydrocarbon productivity and fluid migration. Increased hydrocarbons production occurs where reservoirs are cross-cut by the faults. The faults offset various reservoirs in Pennsylvania and Ohio in the subsurface. Identifying the location of these faults at the surface may provide information that leads top the discovery of new potential reservoirs.

  14. "Features of two proteins of Leptospira interrogans with potential role in host-pathogen interactions"

    PubMed Central

    2012-01-01

    Background Leptospirosis is considered a re-emerging infectious disease caused by pathogenic spirochaetes of the genus Leptospira. Pathogenic leptospires have the ability to survive and disseminate to multiple organs after penetrating the host. Leptospires were shown to express surface proteins that interact with the extracellular matrix (ECM) and to plasminogen (PLG). This study examined the interaction of two putative leptospiral proteins with laminin, collagen Type I, collagen Type IV, cellular fibronectin, plasma fibronectin, PLG, factor H and C4bp. Results We show that two leptospiral proteins encoded by LIC11834 and LIC12253 genes interact with laminin in a dose - dependent and saturable mode, with dissociation equilibrium constants (KD) of 367.5 and 415.4 nM, respectively. These proteins were named Lsa33 and Lsa25 (Leptospiral surface adhesin) for LIC11834 and LIC12253, respectively. Metaperiodate - treated laminin reduced Lsa25 - laminin interaction, suggesting that sugar moieties of this ligand participate in this interaction. The Lsa33 is also PLG - binding receptor, with a KD of 23.53 nM, capable of generating plasmin in the presence of an activator. Although in a weak manner, both proteins interact with C4bp, a regulator of complement classical route. In silico analysis together with proteinase K and immunoflorescence data suggest that these proteins might be surface exposed. Moreover, the recombinant proteins partially inhibited leptospiral adherence to immobilized laminin and PLG. Conclusions We believe that these multifunctional proteins have the potential to participate in the interaction of leptospires to hosts by mediating adhesion and by helping the bacteria to escape the immune system and to overcome tissue barriers. To our knowledge, Lsa33 is the first leptospiral protein described to date with the capability of binding laminin, PLG and C4bp in vitro. PMID:22463075

  15. Interaction of spirochetes with the host fibrinolytic system and potential roles in pathogenesis.

    PubMed

    Vieira, Mônica Larucci; Nascimento, Ana Lucia T O

    2016-08-01

    The pathogenic spirochetes Borrelia burgdorferi, B. hermsii, B. recurrentis, Treponema denticola and Leptospira spp. are the etiologic agents of Lyme disease, relapsing fever, periodontitis and leptospirosis, respectively. Lyme borreliosis is a multi-systemic disorder and the most prevalent tick-borne disease in the northern hemisphere. Tick-borne relapsing fever is persistent in endemic areas worldwide, representing a significant burden in some African regions. Periodontal disease, a chronic inflammatory disorder that often leads to tooth loss, is caused by several potential pathogens found in the oral cavity including T. denticola. Leptospirosis is considered the most widespread zoonosis, and the predominant human disease in tropical, undeveloped regions. What these diseases have in common is that they are a significant burden to healthcare costs in the absence of prophylactic measures. This review addresses the interaction of these spirochetes with the fibrinolytic system, plasminogen (Plg) binding to the surface of bacteria and the generation of plasmin (Pla) on their surface. The consequences on host-pathogen interactions when the spirochetes are endowed with this proteolytic activity are discussed on the basis of the results reported in the literature. Spirochetes equipped with Pla activity have been shown to degrade extracellular matrix (ECM) components, in addition to digesting fibrin, facilitating bacterial invasion and dissemination. Pla generation triggers the induction of matrix metalloproteases (MMPs) in a cascade of events that enhances the proteolytic capacity of the spirochetes. These activities in concert with the interference exerted by the Plg/Pla on the complement system - helping the bacteria to evade the immune system - should illuminate our understanding of the mechanisms involved in host infection. PMID:25914944

  16. Potential effects of erythromycin on host defense systems and virulence of Pseudomonas aeruginosa.

    PubMed Central

    Hirakata, Y; Kaku, M; Mizukane, R; Ishida, K; Furuya, N; Matsumoto, T; Tateda, K; Yamaguchi, K

    1992-01-01

    We evaluated several potential effects of erythromycin (EM) on host defense systems and the virulence of Pseudomonas aeruginosa. Peritoneal macrophages obtained from mice given 250 mg of EM per kg of body weight for 7 days by the intraperitoneal, intravenous, subcutaneous, or oral route produced significantly greater amounts of thymocyte-activating factors. These data suggest that EM enhances the in vivo production of cytokines, such as interleukins 1 and 6. Treatment of P. aeruginosa D4 with subinhibitory concentrations of EM enhanced the association of bacteria with murine Kupffer cells in vitro and increased bacterial clearance from the blood in mice. EM suppressed the in vitro production of exotoxin A, total protease, elastase, and phospholipase C by P. aeruginosa D4; exotoxin A production by P. aeruginosa PA-103; and total protease production by P. aeruginosa B16 and PAO1 in a generally dose-dependent manner. These data demonstrate that EM produces various effects in addition to its direct antimicrobial activity, suggesting that it has potential as an immunomodulator or bacterial virulence-suppressing agent against P. aeruginosa and other infections. PMID:1416882

  17. The potential for hydrocarbon biodegradation and production of extracellular polymeric substances by aerobic bacteria isolated from a Brazilian petroleum reservoir.

    PubMed

    Vasconcellos, S P; Dellagnezze, B M; Wieland, A; Klock, J-H; Santos Neto, E V; Marsaioli, A J; Oliveira, V M; Michaelis, W

    2011-06-01

    Extracellular polymeric substances (EPS) can contribute to the cellular degradation of hydrocarbons and have a huge potential for application in biotechnological processes, such as bioremediation and microbial enhanced oil recovery (MEOR). Four bacterial strains from a Brazilian petroleum reservoir were investigated for EPS production, emulsification ability and biodegradation activity when hydrocarbons were supplied as substrates for microbial growth. Two strains of Bacillus species had the highest EPS production when phenanthrene and n-octadecane were offered as carbon sources, either individually or in a mixture. While Pseudomonas sp. and Dietzia sp., the other two evaluated strains, had the highest hydrocarbon biodegradation indices, EPS production was not detected. Low EPS production may not necessarily be indicative of an absence of emulsifier activity, as indicated by the results of a surface tension reduction assay and emulsification indices for the strain of Dietzia sp. The combined results gathered in this work suggest that a microbial consortium consisting of bacteria with interdependent metabolisms could thrive in petroleum reservoirs, thus overcoming the limitations imposed on each individual species by the harsh conditions found in such environments. PMID:25187151

  18. Geochemically Homogeneous Tuffs Host the Potential Nuclear Waste Repository, Yucca Mountain, Nevada

    SciTech Connect

    Z.E. Peterman

    2001-07-13

    In evaluating a geological environment for the disposition of nuclear waste, the composition of the host rock is an important parameter in characterizing the natural system and its role as a barrier to migration of radionuclides. Emplacement drifts in a potential nuclear waste repository at Yucca Mountain, Nevada, would be constructed in the lower phenocryst-poor rhyolitic member ({approx}300 m thick) of the Topopah Spring Tuff, a felsic pyroclastic ash flow. The rhyolitic member, composed largely of microcrystalline quartz and alkali feldspar, contains localized secondary minerals including vapor-phase silica polymorphs and feldspar typically lining lithophysal cavities, and low-temperature calcite and opal in cavities and fractures. Chemical analyses of Topopah Spring Tuff samples from outcrops and from core obtained by surface-based drilling have shown that the phenocryst-poor rhyolite member at Yucca Mountain is remarkably uniform in composition both vertically and laterally. To verify this geochemical homogeneity in samples collected directly from the repository block where emplacement drifts would be constructed, major and trace elements were analyzed for core samples obtained from 20 systematically spaced drill holes in a drift constructed across the repository block. Means and standard deviations of selected oxides and elements in weight percent indicate geochemical uniformity among these samples: SiO{sub 2}, 76.29 {+-} 0.32; Al{sub 2}O{sub 3}, 12.55 {+-} 0.14; FeO, 0.13 {+-} 0.05; Fe{sub 2}O{sub 3}, 0.97 {+-} 0.07; MgO, 0.12 {+-} 0.02; CaO, 0.50 {+-} 0.03; Na{sub 2}O, 3.52 {+-} 0.11; K{sub 2}O, 4.83 {+-} 0.06; TiO{sub 2}, 0.109 {+-} 0.004; ZrO{sub 2}, 0.016 {+-} 0.001; MnO, 0.068 {+-} 0.008; Cl, 0.017 {+-} 0.004; F, 0.038 {+-} 0.008; and CO{sub 2}, 0.011 {+-} 0.003. Means and standard deviations of selected trace elements, in micrograms per gram, also indicate small compositional variability: Ba, 51 {+-} 12; Cs, 4.2 {+-} 0.3; Li, 25 {+-} 9; Pb, 27 {+-} 1

  19. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    PubMed

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping. PMID:26926485

  20. Transcriptional Portrait of Actinobacillus pleuropneumoniae during Acute Disease - Potential Strategies for Survival and Persistence in the Host

    PubMed Central

    Klitgaard, Kirstine; Friis, Carsten; Jensen, Tim K.; Angen, Øystein; Boye, Mette

    2012-01-01

    Background Gene expression profiles of bacteria in their natural hosts can provide novel insight into the host-pathogen interactions and molecular determinants of bacterial infections. In the present study, the transcriptional profile of the porcine lung pathogen Actinobacillus pleuropneumoniae was monitored during the acute phase of infection in its natural host. Methodology/Principal Findings Bacterial expression profiles of A. pleuropneumoniae isolated from lung lesions of 25 infected pigs were compared in samples taken 6, 12, 24 and 48 hours post experimental challenge. Within 6 hours, focal, fibrino hemorrhagic lesions could be observed in the pig lungs, indicating that A. pleuropneumoniae had managed to establish itself successfully in the host. We identified 237 differentially regulated genes likely to encode functions required by the bacteria for colonization and survival in the host. This group was dominated by genes involved in various aspects of energy metabolism, especially anaerobic respiration and carbohydrate metabolism. Remodeling of the bacterial envelope and modifications of posttranslational processing of proteins also appeared to be of importance during early infection. The results suggested that A. pleuropneumoniae is using various strategies to increase its fitness, such as applying Na+ pumps as an alternative way of gaining energy. Furthermore, the transcriptional data provided potential clues as to how A. pleuropneumoniae is able to circumvent host immune factors and survive within the hostile environment of host macrophages. This persistence within macrophages may be related to urease activity, mobilization of various stress responses and active evasion of the host defenses by cell surface sialylation. Conclusions/Significance The data presented here highlight the importance of metabolic adjustments to host conditions as virulence factors of infecting microorganisms and help to provide insight into the mechanisms behind the efficient

  1. An integrated petrophysical-geophysical approach for the characterization of a potential caprock-reservoir system for CO2 storage.

    NASA Astrophysics Data System (ADS)

    Fais, Silvana; Ligas, Paola; Cuccuru, Francesco; Casula, Giuseppe; Giovanna Bianchi, Maria; Maggio, Enrico; Plaisant, Alberto; Pettinau, Alberto

    2016-04-01

    The selection of a CO2 geologic storage site requires the choice of a study site suitable for the characterization in order to create a robust experimental database especially regarding the spatial petrophysical heterogeneities and elasto-mechanical properties of the rocks that make up a potential caprock-reservoir system. In our study the petrophysical and elasto-mechanical characterization began in a previously well drilled area in the northern part of the Sulcis coal basin (Nuraxi Figus area - SW Sardinia - Italy) where crucial geologic data were recovered from high-quality samples from stratigraphic wells and from mining galleries. The basin represents one of the most important Italian carbon reserves characterized by a great mining potential. In the study area, the Middle Eocene - Lower Oligocene Cixerri Fm. made up of terrigeneous continental rocks and the Upper Thanetian - Lower Ypresian Miliolitico Carbonate Complex in the Sulcis coal basin have been identified respectively as potential caprock and reservoir for CO2 storage. Petrophysical and geophysical investigations were carried out by a great number of laboratory tests on the core samples and in situ measurements on a mining gallery in order to characterize the potential caprock-reservoir system and to substantially reduce geologic uncertainty in the storage site characterization and in the geological and numerical modelling for the evaluation of CO2 storage capacity. In order to better define the spatial distribution of the petrophysical heterogeneity, the seismic responses from the caprock-reservoir system formations were also analysed and correlated with the petrophysical and elasto-mechanical properties In a second step of this work, we also analysed the tectonic stability of the study area by the integrated application of remote-sensing monitoring spatial geodetic techniques. In particular, the global positioning system (GPS) and interferometric synthetic aperture radar (inSAR) were considered

  2. Diagenesis and reservoir potential of volcanogenic sandstones - Cretaceous of the Surat Basin, Queensland, Australia

    SciTech Connect

    Hawlader, H.M. )

    1990-06-01

    The sandstones of the Lower Cretaceous succession of the Surat basin are characterized by abundant volcanogenic detritus in the form of rock-fragments and feldspars derived from an andesitic magmatic arc coincident with the present Great Barrier Reef in offshore Queensland. These compositionally immature sandstones are not regarded as favorable exploration targets because of their labile nature, their shallow burial depths, and hence the low thermal maturity of the intercalated mudrocks that might have constituted hydrocarbon source rocks. However, petrographic and petrophysical examinations show that significant primary and early diagenetic secondary dissolution porosity and permeability exist in some of these stratigraphic units that under certain circumstances could be the host for hydrocarbons and may become the future exploration targets. Flushing by CO{sub 2}-charged meteoric water after the inception of the Great Artesian basin (of which the Surat basin is a component) in the Tertiary is likely to have been the principal agent of secondary porosity development in these sandstones. Additionally, products of microbial degradation of organic matter (in the intercalated mudstones) and/or maturation products from the deeply buried part of the basin might have assisted in the dissolution of framework grains and previously deposited cement.

  3. Evaluation of 31 Potential Biofumigant Brassicaceous Plants as Hosts for Three Meloiodogyne Species

    PubMed Central

    Edwards, Scott; Ploeg, Antoon

    2014-01-01

    Brassicaceous cover crops can be used for biofumigation after soil incorporation of the mowed crop. This strategy can be used to manage root-knot nematodes (Meloidogyne spp.), but the fact that many of these crops are host to root-knot nematodes can result in an undesired nematode population increase during the cultivation of the cover crop. To avoid this, cover crop cultivars that are poor or nonhosts should be selected. In this study, the host status of 31 plants in the family Brassicaceae for the three root-knot nematode species M. incognita, M. javanica, and M. hapla were evaluated, and compared with a susceptible tomato host in repeated greenhouse pot trials. The results showed that M. incognita and M. javanica responded in a similar fashion to the different cover cultivars. Indian mustard (Brassica juncea) and turnip (B. rapa) were generally good hosts, whereas most oil radish cultivars (Raphanus. sativus ssp. oleiferus) were poor hosts. However, some oil radish cultivars were among the best hosts for M. hapla. The arugula (Eruca sativa) cultivar Nemat was a poor host for all three nematode species tested. This study provides important information for chosing a cover crop with the purpose of managing root-knot nematodes. PMID:25276003

  4. Evaluation of 31 potential biofumigant brassicaceous plants as hosts for three meloiodogyne species.

    PubMed

    Edwards, Scott; Ploeg, Antoon

    2014-09-01

    Brassicaceous cover crops can be used for biofumigation after soil incorporation of the mowed crop. This strategy can be used to manage root-knot nematodes (Meloidogyne spp.), but the fact that many of these crops are host to root-knot nematodes can result in an undesired nematode population increase during the cultivation of the cover crop. To avoid this, cover crop cultivars that are poor or nonhosts should be selected. In this study, the host status of 31 plants in the family Brassicaceae for the three root-knot nematode species M. incognita, M. javanica, and M. hapla were evaluated, and compared with a susceptible tomato host in repeated greenhouse pot trials. The results showed that M. incognita and M. javanica responded in a similar fashion to the different cover cultivars. Indian mustard (Brassica juncea) and turnip (B. rapa) were generally good hosts, whereas most oil radish cultivars (Raphanus. sativus ssp. oleiferus) were poor hosts. However, some oil radish cultivars were among the best hosts for M. hapla. The arugula (Eruca sativa) cultivar Nemat was a poor host for all three nematode species tested. This study provides important information for chosing a cover crop with the purpose of managing root-knot nematodes. PMID:25276003

  5. Olfactory host finding, intermediate memory and its potential ecological adaptation in Nasonia vitripennis

    NASA Astrophysics Data System (ADS)

    Schurmann, Daria; Collatz, Jana; Hagenbucher, Steffen; Ruther, Joachim; Steidle, Johannes L. M.

    2009-03-01

    Associative learning of host-associated chemical cues was studied in Nasonia vitripennis, a parasitoid of fly pupae in nests of hole-nesting birds. When females encountered a fly pupa and performed one sequence of host recognition behaviour including drilling the ovipositor into the host in the presence of the artificial odour furfurylheptanoate (FFH), they were afterwards arrested by FFH in olfactometer experiments. The response vanished after 4 days and could be blocked after 3 days by feeding wasps with ethacrynic acid prior and after the training. This indicates the formation of an intermediate form of memory by one host experience in N. vitripennis. Interestingly, the trained wasps avoided odours that were not present during the host encounter, although naive wasps did not react to these odours. This unique behaviour probably causes wasps to focus during host searching on those chemical cues they have experienced in the host environment. Studies in nests of hole-nesting birds revealed that about 30% of all nests contained only one fly pupa, and laboratory studies showed that N. vitripennis females are able to parasitise around 100 fly pupae in their life. It is discussed that under these conditions, the formation of a non-permanent intermediate memory for host-associated odours after one host encounter is adaptive to avoid costs involved with formation and maintenance of memory for misleading cues. The demonstration of associative olfactory learning in N. vitripennis, the first parasitoid species with sequenced genome, opens the gate to study molecular mechanisms of memory formation and its ecological adaptation in parasitoids.

  6. Host specificity assessment and potential impact of Megamelus scutellaris Berg (Hemiptera: Delphacidae) on waterhyacinth (Eichhornia crassipes Mart. Pontederiales: Pontederiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The delphacid Megamelus scutellaris Berg was evaluated for host specificity and potential impact as part of a biological control program targeting E. crassipes. Survival and development of adults and nymphs were used as metrics with no-choice, choice, nymph transfer, and sustainability tests conduc...

  7. Characterization of chromophoric dissolved organic matter and trihalomethane formation potential in a recently constructed reservoir and the surrounding areas - Impoundment effects

    NASA Astrophysics Data System (ADS)

    Hur, Jin; Lee, Bo-Mi; Lee, Seungyoon; Shin, Jae-Ki

    2014-07-01

    The effects of the dam impoundment on the distribution of chromophoric dissolved organic matter (CDOM) were evaluated for a dam reservoir (the Gunwi reservoir) at an early impoundment stage by comparing the characteristics of CDOM and trihalomethane (THM) precursors among the upstream catchment areas, the dam reservoir, and a downstream site. Sampling was conducted for two separate sampling periods of a non-storm event in May and a storm event in August, 2012. The dam reservoir had experienced long-term enrichment of non-biodegradable organic matter since its construction in February, 2010. In May, significant differences were observed in several selected CDOM properties between the upstream catchments and the locations affected by the impoundment (i.e., within the reservoir and the downstream sites). For the storm event, however, such impoundment effects became much less pronounced likely due to elevated input of CDOM with terrestrial origin into the reservoir. Specific THM formation potential (STHMFP) did not show the same spatial distinction as those of CDOM for both sampling periods. Three fluorophore groups were identified from fluorescence excitation-emission matrices (EEMs) of the collected samples by parallel factor analysis (PARAFAC) modeling. Protein-like and microbial humic-like components were relatively more enriched for the impoundment-affected sites compared to the upstream locations, in which terrestrial humic-like component was more dominant. Principal component analysis (PCA) demonstrated that the accumulation of non-biodegradable organic matter in the dam reservoir might be attributed to microbial humification of the algal-derived organic substances originated from either periphytons flushed from upstream stream beds or decomposing algae settled on the bottom of the reservoir, or both.

  8. The European hare (Lepus europaeus) as a potential wild reservoir for ruminant pestiviruses.

    PubMed

    Colom-Cadena, A; Cabezón, O; Rosell, R; Fernández-Aguilar, X; Blanch-Lázaro, B; Tetas, E; Lavín, S; Marco, I

    2016-09-01

    Ruminant pestiviruses cause important economic losses in livestock and the epidemiological role of free-ranging sympatric wildlife is of special interest for the implementation of pestivirus eradication plans. Moreover, the emergence of high mortality outbreaks of pestivirus in Pyrenean chamois (Rupicapra pyrenaica pyrenaica) since 2001 in the border between Spain and France has increased the value of knowing the hosts that role pestivirus infection. In the present study, pestivirus infection was assessed in 94 sera from wild hunted European hares (Lepus europaeus) collected in two different areas: Pyrenees (alpine and subalpine ecosystems) versus Non Pyrenees (non alpine and subalpine ecosystems). The presence of antibodies against Border Disease Virus (BDV) and Bovine Viral Diarrhea Virus (BVDV) was evaluated by means of the Virus Neutralization Test and the presence of viral RNA in sera samples was assessed by Reverse transcription-polymerase chain reaction (RT-PCR). A total of 34 out of 94 (36.2%; CI95 0.26-0.46) sera presented neutralizing antibodies against ruminant pestiviruses, and significant differences between BDV4 and BVDV1 titres were found in 7 hares. In the Pyrenean area not statistically significant seroprevalence was observed when comparing with the Non Pyrenean area. RT-PCR analysis of sera samples resulted all negative. The results of the present study indicate that the European hare is susceptible to pestivirus infection and that could be involved in the epidemiology of ruminant pestiviruses. To the authors' knowledge, this is the third wild non-artiodactyl with reported antibodies against ruminant pestivirus after the rabbit and Bennet's wallaby. PMID:27544252

  9. [Echinococcus multilocularis in Grisons: distribution in foxes and presence of potential intermediate hosts].

    PubMed

    Tanner, F; Hegglin, D; Thoma, R; Brosi, G; Deplazes, P

    2006-09-01

    The southern border of the European endemic area of Echinococcus multilocularis runs along the alpine crest. This endemic transition area was analysed in the canton Grisons on a small spatial scale. A total of 543 foxes originating from 10 areas north and 4 areas south of the main alpine divide were investigated. Parasites were isolated using the sedimentation and counting technique on intestinal contents. The mean prevalence of E. multilocularis was 6.4% with significant differences between different areas. In the southern valleys, only foxes from the Val Müstair were infected (14.3%). On the northern side of the main alpine divide, prevalences varied between 0 and 40%. The predation habits of foxes on potential intermediate hosts was investigated by means of stomach content analyses (n=530). Rodents of the genera Microtus/Pitymys were found in 19.6% of fox stomachs, Clethrionomys glareolus in 8.0% and Arvicola terrestris in 0.4%. A small scale analysis based on a 10 x 10 km grid suggested that the predation rate on the genera Microtus/Pitymys significantly correlated with the prevalence of E. multilocularis in foxes (Spearman's r = 0.51). Hence, E. multilocularis appears to occur in the alpine study area on a very small spatial scale. These local sources of infection may persist for decades. This may partly explains why, during the last 34 years, some human cases of alveolar echinococcosis occurred in areas of the Canton Grisons where the parasite is presently endemic in foxes. No such human cases have been recorded in other areas free of E. multilocularis. PMID:17024979

  10. The Monogenean Parasite Fauna of Cichlids: A Potential Tool for Host Biogeography

    PubMed Central

    Pariselle, Antoine; Boeger, Walter A.; Snoeks, Jos; Bilong Bilong, Charles F.; Morand, Serge; Vanhove, Maarten P. M.

    2011-01-01

    We discuss geographical distribution and phylogeny of Dactylogyridea (Monogenea) parasitizing Cichlidae to elucidate their hosts' history. Although mesoparasitic Monogenea (Enterogyrus spp.) show typical vicariant distribution, ectoparasitic representatives from different continents are not considered sister taxa, hence their distribution cannot result from vicariance alone. Because of the close host-parasite relationship, this might indicate that present-day cichlid distribution may also reflect dispersal through coastal or brackish waters. Loss of ectoparasites during transoceanic migration, followed by lateral transfer from other fish families might explain extant host-parasite associations. Because of its mesoparasitic nature, hence not subject to salinity variations of the host's environment, Enterogyrus could have survived marine migrations, intolerable for ectoparasites. Host-switches and salinity transitions may be invoked to explain the pattern revealed by a preliminary morphological phylogeny of monogenean genera from Cichlidae and other selected Monogenea genera, rendering the parasite distribution explicable under both vicariance and dispersal. Testable hypotheses are put forward in this parasitological approach to cichlid biogeography. Along with more comprehensive in-depth morphological phylogeny, comparison with molecular data, clarifying dactylogyridean evolution on different continents and from various fish families, and providing temporal information on host-parasite history, are needed to discriminate between the possible scenarios. PMID:21869935

  11. Potential non-tertiary additional oil recovery from heterogeneous submarine-fan reservoirs, Spraberry-Benedum field, Midland basin, Texas

    SciTech Connect

    Guevara, E.H.; Worrall, J.G.; Walter, T.

    1987-05-01

    The Spraberry-Benedum field is a multipay, solution-gas drive, combined structural-stratigraphic trap. It contains approximately 200 million bbl of original oil in place and has been waterflooded since 1967. Producing intervals are in the Spraberry formation (Permian, Leonardian), which in this area consists of mixed-sediment submarine-fan deposits (upper and lower Spraberry) and basin-plain facies (middle Spraberry). Principal oil reservoirs, with 12% average porosity and permeabilities of less than 1 md, occur in the lower and upper Spraberry. They consist of naturally fractured, very fine-grained sandstones and coarse siltstones of braided and meandering, peripheral channels and associated outer fan facies. Complex facies architecture results in highly heterogeneous reservoirs. Oil accumulations are layered because basin-plain shales vertically separate submarine-fan reservoirs, and they are laterally compartmentalized due to the channelization of reservoir rocks. Production trends locally parallel to facies trends indicate that recovery is influenced by reservoir stratigraphy. Well locations, based only on structural position and fracture orientation, commonly do not conform to the axes of belts of greatest sandstone-siltstone thickness, which contain the best reservoirs. Furthermore, completion intervals do not systematically tap both lower and upper Spraberry reservoirs. Ultimate recovery will be improved by aggressive development programs aimed at producing from poorly drained traps created by reservoir heterogeneities. Recompletion and deepening of wells, strategic infill drilling, and injection patterns in such programs should be based on detailed reservoir stratigraphy, in addition to structure and fracture data.

  12. Evaluation of potential geothermal reservoirs in central and western New York State. Volume 3. Final report

    SciTech Connect

    Not Available

    1983-06-01

    Computer processed geophysical well logs from central and western New York State were analysed to evaluate the potential of subsurface formations as a source for low-temperature geothermal water. The analysis indicated that porous sandstone sections at the top of the Ordovician Theresa Formation and at the base of the Cambrian Potsdam Formation have the required depth, porosity, and permeability to act as a source for geothermal fluids over a relatively large area in the central part of the state. The fluid potential plus an advantageous geothermal gradient and the results of the test well drilled in the city of Auburn in Cayuga County suggest that low temperature geothermal energy may ba a viable alternative to other more conventional forms of energy that not indigenous to New York State.

  13. Evaluation of potential geothermal reservoirs in central and western New York state. Final report

    SciTech Connect

    Not Available

    1983-06-01

    Computer processes geophysical well logs from central and western New York State were analyzed to evaluate the potential of subsurface formations as a source for low-temperature geothermal water. The analysis indicated that porous sandstone sections at the top of the Ordovician Theresa Formation and at the base of the Cambrian Potsdam Formation have the required depth, porosity, and permeability to act as a source for geothermal fluids over a relatively large area in the central part of the state. The fluid potential plus an advantageous geothermal gradient and the results of the test well drilled in the city of Auburn in Cayuga County suggest that low temperature geothermal energy may be a viable alternative to other more conventional forms of energy that are not indigenous to New York State.

  14. Undiscovered Bat Hosts of Filoviruses

    PubMed Central

    Schmidt, John Paul; Alexander, Laura W.; Bowden, Sarah E.; Hayman, David T. S.; Drake, John M.

    2016-01-01

    Ebola and other filoviruses pose significant public health and conservation threats by causing high mortality in primates, including humans. Preventing future outbreaks of ebolavirus depends on identifying wildlife reservoirs, but extraordinarily high biodiversity of potential hosts in temporally dynamic environments of equatorial Africa contributes to sporadic, unpredictable outbreaks that have hampered efforts to identify wild reservoirs for nearly 40 years. Using a machine learning algorithm, generalized boosted regression, we characterize potential filovirus-positive bat species with estimated 87% accuracy. Our model produces two specific outputs with immediate utility for guiding filovirus surveillance in the wild. First, we report a profile of intrinsic traits that discriminates hosts from non-hosts, providing a biological caricature of a filovirus-positive bat species. This profile emphasizes traits describing adult and neonate body sizes and rates of reproductive fitness, as well as species’ geographic range overlap with regions of high mammalian diversity. Second, we identify several bat species ranked most likely to be filovirus-positive on the basis of intrinsic trait similarity with known filovirus-positive bats. New bat species predicted to be positive for filoviruses are widely distributed outside of equatorial Africa, with a majority of species overlapping in Southeast Asia. Taken together, these results spotlight several potential host species and geographical regions as high-probability targets for future filovirus surveillance. PMID:27414412

  15. Undiscovered Bat Hosts of Filoviruses.

    PubMed

    Han, Barbara A; Schmidt, John Paul; Alexander, Laura W; Bowden, Sarah E; Hayman, David T S; Drake, John M

    2016-07-01

    Ebola and other filoviruses pose significant public health and conservation threats by causing high mortality in primates, including humans. Preventing future outbreaks of ebolavirus depends on identifying wildlife reservoirs, but extraordinarily high biodiversity of potential hosts in temporally dynamic environments of equatorial Africa contributes to sporadic, unpredictable outbreaks that have hampered efforts to identify wild reservoirs for nearly 40 years. Using a machine learning algorithm, generalized boosted regression, we characterize potential filovirus-positive bat species with estimated 87% accuracy. Our model produces two specific outputs with immediate utility for guiding filovirus surveillance in the wild. First, we report a profile of intrinsic traits that discriminates hosts from non-hosts, providing a biological caricature of a filovirus-positive bat species. This profile emphasizes traits describing adult and neonate body sizes and rates of reproductive fitness, as well as species' geographic range overlap with regions of high mammalian diversity. Second, we identify several bat species ranked most likely to be filovirus-positive on the basis of intrinsic trait similarity with known filovirus-positive bats. New bat species predicted to be positive for filoviruses are widely distributed outside of equatorial Africa, with a majority of species overlapping in Southeast Asia. Taken together, these results spotlight several potential host species and geographical regions as high-probability targets for future filovirus surveillance. PMID:27414412

  16. Seawater is a reservoir of multi-resistant Escherichia coli, including strains hosting plasmid-mediated quinolones resistance and extended-spectrum beta-lactamases genes

    PubMed Central

    Alves, Marta S.; Pereira, Anabela; Araújo, Susana M.; Castro, Bruno B.; Correia, António C. M.; Henriques, Isabel

    2014-01-01

    The aim of this study was to examine antibiotic resistance (AR) dissemination in coastal water, considering the contribution of different sources of fecal contamination. Samples were collected in Berlenga, an uninhabited island classified as Natural Reserve and visited by tourists for aquatic recreational activities. To achieve our aim, AR in Escherichia coli isolates from coastal water was compared to AR in isolates from two sources of fecal contamination: human-derived sewage and seagull feces. Isolation of E. coli was done on Chromocult agar. Based on genetic typing 414 strains were established. Distribution of E. coli phylogenetic groups was similar among isolates of all sources. Resistances to streptomycin, tetracycline, cephalothin, and amoxicillin were the most frequent. Higher rates of AR were found among seawater and feces isolates, except for last-line antibiotics used in human medicine. Multi-resistance rates in isolates from sewage and seagull feces (29 and 32%) were lower than in isolates from seawater (39%). Seawater AR profiles were similar to those from seagull feces and differed significantly from sewage AR profiles. Nucleotide sequences matching resistance genes blaTEM, sul1, sul2, tet(A), and tet(B), were present in isolates of all sources. Genes conferring resistance to 3rd generation cephalosporins were detected in seawater (blaCTX-M-1 and blaSHV-12) and seagull feces (blaCMY-2). Plasmid-mediated determinants of resistance to quinolones were found: qnrS1 in all sources and qnrB19 in seawater and seagull feces. Our results show that seawater is a relevant reservoir of AR and that seagulls are an efficient vehicle to spread human-associated bacteria and resistance genes. The E. coli resistome recaptured from Berlenga coastal water was mainly modulated by seagulls-derived fecal pollution. The repertoire of resistance genes covers antibiotics critically important for humans, a potential risk for human health. PMID:25191308

  17. The reservoir of ozone in the boundary layer of the eastern United States and its potential impact on the global tropospheric ozone budget

    NASA Technical Reports Server (NTRS)

    Vukovich, F. M.; Fishman, J.; Browell, E. V.

    1985-01-01

    An analysis of available ozone data in the eastern two-thirds of the United States indicates that a substantial reservoir of ozone is present in the summertime. Five-year mean concentrations range from 40 to 65 ppbv. The reservoir covered an area of several million square kilometers and extends vertically from the surface to 1 to 2 km. The vertical distribution of ozone in the reservoir during midday supports a transport of additional ozone from the boundary layer to the free troposphere. Data are presented demonstrating the potential effect of transport by convective clouds and by the sea breeze circulation - mechanisms by which ozone may be transported out of the boundary layer into the free troposphere. The potential impact of this reservoir on the tropospheric ozone budget is discussed. It is shown that if less than half of the ozone mass in this reservoir is transported to the free troposphere, then the amount of ozone transported out of the boundary layer approximates the amount of ozone transported downward during a tropopause fold event.

  18. Evaluation of sediments in the Middle Rio Grande, Elephant Butte Reservoir, and Caballo Reservoir as potential sources for toxic materials. Technical report

    SciTech Connect

    Popp, C.J.; Brandvold, D.K.; Lynch, T.R.; Brandvold, L.A.

    1983-03-01

    The distribution of a large number of priority pollutant trace metal and organic species in water and sediments in surface waters in the Middle Rio Grande region of New Mexico has been surveyed. In addition to sediments and water, limnological data was collected on the reservoirs, radionuclide and particle size analysis was performed on the sediments and a limited number of fish were surveyed for trace metals and organics. The sediments carry elevated levels of the metals Hg, Cd, As, Se, and U and fish may be biomagnifying Hg, Pb, and V through the food chain. Detectable levels of 18 different chlorinated organic pesticides were found in samples of water and bottom sediments.

  19. Amnion and Chorion Membranes: Potential Stem Cell Reservoir with Wide Applications in Periodontics

    PubMed Central

    2015-01-01

    The periodontal therapy usually aims at elimination of disease causing bacteria and resolution of inflammation. It involves either resective or regenerative surgery to resolve the inflammation associated defects. Over the years, several methods have been used for achievement of periodontal regeneration. One of the oldest biomaterials used for scaffolds is the fetal membrane. The amniotic membranes of developing embryo, that is, amnion (innermost lining) and chorion (a layer next to it), have the properties with significant potential uses in dentistry. This paper reviews the properties, mechanism of action, and various applications of these placental membranes in general and specifically in Periodontics. PMID:26770199

  20. Microbial redox processes in deep subsurface environments and the potential application of (per)chlorate in oil reservoirs

    PubMed Central

    Liebensteiner, Martin G.; Tsesmetzis, Nicolas; Stams, Alfons J. M.; Lomans, Bartholomeus P.

    2014-01-01

    The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron, or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese-, and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (per)chlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (per)chlorate for bioremediation, souring control, and microbial enhanced oil recovery are addressed. PMID:25225493

  1. Microbial redox processes in deep subsurface environments and the potential application of (per)chlorate in oil reservoirs.

    PubMed

    Liebensteiner, Martin G; Tsesmetzis, Nicolas; Stams, Alfons J M; Lomans, Bartholomeus P

    2014-01-01

    The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron, or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese-, and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (per)chlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (per)chlorate for bioremediation, souring control, and microbial enhanced oil recovery are addressed. PMID:25225493

  2. Calculation of the absolute thermodynamic properties of association of host-guest systems from the intermolecular potential of mean force.

    PubMed

    Ghoufi, Aziz; Malfreyt, Patrice

    2006-12-14

    The authors report calculations of the intermolecular potential of mean force (PMF) in the case of the host-guest interaction. The host-guest system is defined by a water soluble calixarene and a cation. With an organic cation such as the tetramethylammonium cation, the calixarene forms an insertion complex, whereas with the Lanthane cation, the supramolecular assembly is an outer-sphere complex. The authors apply a modified free energy perturbation method and the force constraint technique to establish the PMF profiles as a function of the separation distance between the host and guest. They use the PMF profile for the calculation of the absolute thermodynamic properties of association that they compare to the experimental values previously determined. They finish by giving some structural features of the insertion and outer-sphere complexes at the Gibbs free energy minimum. PMID:17176145

  3. Source Term Modeling for Evaluating the Potential Impacts to Groundwater of Fluids Escaping from a Depleted Oil Reservoir Used for Carbon Sequestration

    SciTech Connect

    Cantrell, Kirk J.; Brown, Christopher F.

    2014-06-13

    In recent years depleted oil reservoirs have received special interest as carbon storage reservoirs because of their potential to offset costs through collaboration with enhanced oil recovery projects. Modeling is currently being conducted to evaluate potential risks to groundwater associated with leakage of fluids from depleted oil reservoirs used for storage of CO2. Modeling results reported here focused on understanding how toxic organic compounds found in oil will distribute between the various phases within a storage reservoir after introduction of CO2, understanding the migration potential of these compounds, and assessing potential groundwater impacts should leakage occur. Two model scenarios were conducted to evaluate how organic components in oil will distribute among the phases of interest (oil, CO2, and brine). The first case consisted of 50 wt.% oil and 50 wt.% water; the second case was 90 wt.% CO2 and 10 wt.% oil. Several key organic compounds were selected for special attention in this study based upon their occurrence in oil at significant concentrations, relative toxicity, or because they can serve as surrogate compounds for other more highly toxic compounds for which required input data are not available. The organic contaminants of interest (COI) selected for this study were benzene, toluene, naphthalene, phenanthrene, and anthracene. Partitioning of organic compounds between crude oil and supercritical CO2 was modeled using the Peng-Robinson equation of state over temperature and pressure conditions that represent the entire subsurface system (from those relevant to deep geologic carbon storage environments to near surface conditions). Results indicate that for a typical set of oil reservoir conditions (75°C, and 21,520 kPa) negligible amounts of the COI dissolve into the aqueous phase. When CO2 is introduced into the reservoir such that the final composition of the reservoir is 90 wt.% CO2 and 10 wt.% oil, a significant fraction of the oil

  4. Wild and synanthropic reservoirs of Leishmania species in the Americas

    PubMed Central

    Roque, André Luiz R.; Jansen, Ana Maria

    2014-01-01

    The definition of a reservoir has changed significantly in the last century, making it necessary to study zoonosis from a broader perspective. One important example is that of Leishmania, zoonotic multi-host parasites maintained by several mammal species in nature. The magnitude of the health problem represented by leishmaniasis combined with the complexity of its epidemiology make it necessary to clarify all of the links in transmission net, including non-human mammalian hosts, to develop effective control strategies. Although some studies have described dozens of species infected with these parasites, only a minority have related their findings to the ecological scenario to indicate a possible role of that host in parasite maintenance and transmission. Currently, it is accepted that a reservoir may be one or a complex of species responsible for maintaining the parasite in nature. A reservoir system should be considered unique on a given spatiotemporal scale. In fact, the transmission of Leishmania species in the wild still represents an complex enzootic “puzzle”, as several links have not been identified. This review presents the mammalian species known to be infected with Leishmania spp. in the Americas, highlighting those that are able to maintain and act as a source of the parasite in nature (and are thus considered potential reservoirs). These host/reservoirs are presented separately in each of seven mammal orders – Marsupialia, Cingulata, Pilosa, Rodentia, Primata, Carnivora, and Chiroptera – responsible for maintaining Leishmania species in the wild. PMID:25426421

  5. Testing new methodologies and assessing their potential for reservoir characterisation: Geoelectrical studies in the Northwest Carboniferous Basin (Ireland).

    NASA Astrophysics Data System (ADS)

    Ogaya, Xènia; Campanyà, Joan; Rath, Volker; Jones, Alan G.; Reay, Derek; Raine, Rob; McConnell, Brian; Ledo, Juanjo

    2016-04-01

    The overarching objective of this study is to improve our methods of characterising saline aquifers by integrating newly acquired electromagnetic data with existing geophysical and geological data. The work presented here is part of an ongoing project to evaluate Ireland's potential for onshore carbon sequestration (IRECCSEM; funded by Science Foundation Ireland). The methodology presented in this characterisation work is not only relevant for studying the potential for onshore carbon sequestration, but is generally applicable for aquifer characterisation, particularly for the evaluation of geothermal resources in appropriate geological settings. We present first results of the three-dimensional (3D) modelling and inversion of the magnetotelluric (MT) data acquired in the Northwest Carboniferous Basin (Ireland) in summer 2015. The electrical resistivity distribution beneath the survey area is constrained using a joint inversion of three different types of electromagnetic data: MT impedance tensor responses (Z), geomagnetic transfer functions (GTF) and inter-station horizontal magnetic transfer-functions (HMT). The preliminary 3D resistivity model obtained reveals the geoelectrical structure of the subsurface, which is translated into parameters relevant to fluid flow. The electromagnetic data were acquired along profiles linking four wells drilled in the area and the available well log data from those wells are used to evaluate some of the existing petrophysical relationships and calibrate them for the study area. This allows us to interpolate the rock physical properties from one well to another well, using the computed geoelectrical model as a reference. The obtained results are compared to available independent geological and geophysical data in order to analyse the validity of this technique, to characterise the uncertainties inherent to our approach, and to assess the potential of this methodology for reservoir characterisation.

  6. The potential for cereal rye cover crops to host corn seedling pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil health and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects by growing two grass species in succession. Here, we show that rye cover crops host pathog...

  7. A Procedure for Estimating Enrollment and Cost Factors at Potential AFROTC Host-Sites.

    ERIC Educational Resources Information Center

    Alley, William E.; Berberich, George L.

    The development of effectiveness criteria for AFROTC detachments, and relationships between the criteria and various environmental and program characteristics are described. The objective of the study is the development of a method for estimating student enrollments and total operating costs at perspective host-site institutions by using…

  8. Asynchronous development of Honey Bee host and Varroa destructor (Mesostigmata: Varroidae) influences reproductive potential of mites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high proportion of non-reproductive (NR) Varroa destructor, is commonly observed in honey bee colonies displaying the Varroa sensitive hygienic trait (VSH). These studies were conducted to determine the influence of brood removal and subsequent host re-invasion of Varroa mites on mite reproduction...

  9. Host status and damage potential of Paratrichodorus renifer and Pratylenchus penetrans (Nematoda) to blueberry (Vaccinium spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stubby root nematodes (Paratrichodorus species) and root lesion nematodes (Pratylenchus species) have been associated with blueberry in most blueberry-growing regions of North America. Relatively little is known, however, of the host status and pathogenicity of these nematodes to blueberry. We per...

  10. Infection Potential of Hairy Nightshade By Phytophthora infestans and Epidemiological Implications of the Alternate Host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hairy nightshade (Solanum sarrachoides Sendt) is a common weed in the potato agro-ecosystem that can serve as an alternate host for late blight. The epidemiological significance of hairy nightshade to potato late blight has not been documented. Infection rates of P. infestans on potato and hairy nig...