Science.gov

Sample records for anticuerpos contra virus

  1. Diagnóstico diferencial en la encefalitis por anticuerpos contra el receptor NMDA

    PubMed Central

    González-Valcárcel, J.; Rosenfeld, M.R.; Dalmau, J.

    2011-01-01

    Resumen Introducción La encefalitis por anticuerpos contra el receptor de NMDA (NMDAR) suele desarrollarse como un síndrome característico de evolución multifásica y diagnóstico diferencial amplio. Pacientes Presentamos a 2 pacientes diagnosticadas de encefalitis por anticuerpos NMDAR con un cuadro clínico típico, pero que inicialmente señaló otras etiologías. Discusión La afectación frecuente de pacientes jóvenes con manifestaciones psiquiátricas prominentes indica frecuentemente otras consideraciones diagnósticas; las más frecuentes son las encefalitis virales, los procesos psiquiátricos y el síndrome neuroléptico maligno. Varios síndromes previamente definidos de manera parcial o descriptiva en adultos y pacientes pediátricos probablemente eran casos de encefalitis anti-NMDAR. Conclusiones La encefalitis anti-NMDAR debe considerarse en pacientes jóvenes con manifestaciones psiquiátricas subagudas, movimientos anormales y alteraciones autonómicas. La caracterización clínica e inmunológica de esta enfermedad ha llevado a la identificación de nuevos anticuerpos que afectan a procesos de memoria, aprendizaje, conducta y psicosis. PMID:20964986

  2. Encefalitis por anticuerpos contra el receptor de NMDA: experiencia con seis pacientes pediátricos. Potencial eficacia del metotrexato

    PubMed Central

    Bravo-Oro, Antonio; Abud-Mendoza, Carlos; Quezada-Corona, Arturo; Dalmau, Josep; Campos-Guevara, Verónica

    2016-01-01

    Introducción La encefalitis por anticuerpos contra el receptor de N-metil-D-aspartato (NMDA) es una entidad cada vez más diagnosticada en edad pediátrica. A diferencia de los adultos, en muchos casos no se asocia a tumores y las manifestaciones iniciales en niños más frecuentes son crisis convulsivas y trastornos del movimiento, mientras que en los adultos predominan las alteraciones psiquiátricas. Casos clínicos Presentamos seis casos pediátricos confirmados con anticuerpos contra la subunidad NR1 del receptor de NMDA en suero y líquido cefalorraquídeo. Cinco de los casos comenzaron con crisis convulsivas como manifestación clínica inicial antes de desarrollar el cuadro clásico de esta entidad. En todos los casos se utilizaron esteroides como primera línea de tratamiento, con los que sólo se observó control de las manifestaciones en uno, por lo que el resto de los pacientes requirió inmunomoduladores de segunda línea. Todos los pacientes recibieron metotrexato como tratamiento inmunomodulador para evitar recaídas y la evolución fue a la mejoría en todos ellos. Conclusiones En nuestra serie de pacientes con encefalitis por anticuerpos contra el receptor de NMDA, ninguno se asoció a tumores. Todos los casos recibieron metotrexato por lo menos durante un año, no observamos eventos adversos clínicos ni por laboratorio, ni hubo secuelas neurológicas ni recaídas durante el tratamiento. Aunque es una serie pequeña y es deseable incrementar el número y tiempo de evolución, consideramos el metotrexato una excelente alternativa como tratamiento inmunomodulador para esta patología. PMID:24150952

  3. Release of interleukin 1 inhibitory activity (contra-IL-1) by human monocyte-derived macrophages infected with human immunodeficiency virus in vitro and in vivo.

    PubMed Central

    Locksley, R M; Crowe, S; Sadick, M D; Heinzel, F P; Gardner, K D; McGrath, M S; Mills, J

    1988-01-01

    Infection of monocyte-macrophages with human immunodeficiency virus may be central to the pathogenesis of the acquired immunodeficiency syndrome. The ability of infected macrophages to prime T cells through IL-1 production was investigated in vitro. Purified human monocytes maintained in suspension culture were infected with strain HIV-DV. Intracellular expression of virus p24 antigen increased from undetectable levels immediately after infection to 13-59% of cells by 10-14 d; infected macrophages remained viable for up to 60 d. Supernatants collected between 14 and 20 d after infection were examined in the murine thymocyte co-mitogenesis assay and demonstrated to contain a potent IL-1 inhibitor, designated contra-IL-1. Contra-IL-1 activity was present in all supernatants examined after 4 d of infection, and peaked coincident with peak p24 antigen expression. Inhibitory activity was not present in uninfected cells. Contra-IL-1 activity eluted after gel filtration with an approximate molecular weight of 9 kD. Inhibitory activity was removed by exposure to heat or acid pH, or by incubation with chymotrypsin or staphylococcal V8 protease. Contra-IL-1 did not inhibit IL-2- or IL-4-dependent proliferation of murine T cell lines. Despite its ability to inhibit IL-1 activity, contra-IL-1 did not interfere with the binding of recombinant IL-1 beta to a fibroblast cell line. Contra-IL-1 inhibited the proliferation of normal peripheral blood mononuclear cells to both concanavalin A and tetanus toxoid; inhibition could be attenuated by the addition of exogenous IL-1. Messenger RNA extracted from infected macrophages was examined by Northern analysis for the presence of message to IL-1 beta. No message was apparent, suggesting that the presence of contra-IL-1 was not obscuring the concomitant release of IL-1. Infected macrophages stimulated with endotoxin generated readily detectable message for IL-1 beta. Spleen macrophages purified from two patients with AIDS complicated by

  4. Contra continuity and almost contra continuity in generalized fuzzy topological spaces

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Baby; Chakraborty, Jayasree

    2015-05-01

    In this paper we introduce fuzzy contra continuity and almost contra continuity in generalized fuzzy topological space. Fuzzy almost contra continuity is weaker than fuzzy contra continuity in generalized fuzzy topological space. Then we investigate their characterizations and properties. We also established some equivalent relation on fuzzy contra continuity and fuzzy almost contra continuity in generalized fuzzy topological spaces.

  5. Pro and contra IBR-eradication.

    PubMed

    Ackermann, Mathias; Engels, Monika

    2006-03-31

    Bovine herpesvirus type 1 (BoHV-1) is the causative agent of respiratory and genital tract infections such as infectious rhinotracheitis (IBR), infectious pustular vulvovaginitis (IPV, balanoposthitis (IBP), and abortion. Despite of a pronounced immune response, the virus is never eliminated from an infected host but establishes life-long latency and may be reactivated at intervals. Europe has a long history of fighting against BoHV-1 infections, yet, only a small number of countries has achieved IBR-eradication. Therefore, it seemed appropriate to review the reasoning pro and contra such a task. Clearly, the goal can indeed be achieved as has been demonstrated by a number of European countries. However, detection and stamping out of seemingly healthy virus carriers is inevitable in the process. Unfortunately, the use of vaccines is only of temporary and limited value. Therefore, there are numerous considerations to be put forward against such plans, including the high costs, the great risks, and the unsatisfactory quality of tools. If either control or eradication of IBR is nonetheless a goal, then better vaccines are needed as well as better companion tests. Moreover, better tools for the characterization of viral isolates are required. Collaborative actions to gather viral strains from as many countries as possible for inclusion into a newly created clustering library would be most advantageous.

  6. [Perinatal infection by rubella virus in breast-fed babies with congenital heart disease].

    PubMed

    Solórzano-Santos, Fortino; Bárcenas-López, Selene Jeannette; Huerta-García, Gloria C; Miranda-Novales, María Guadalupe; Alvarez-Y Muñoz, María Teresa; Vázquez-Rosales, José Guillermo

    2013-01-01

    Introducción: las encuestas seroepidemiológicas sugieren que 20 % de las mujeres en edad fértil es susceptible a la rubéola. El objetivo de esta investigación fue determinar la frecuencia de infección perinatal por el virus de la rubéola en lactantes con cardiopatía congénita. Métodos: estudio prospectivo y transversal de niños menores de un año de edad con diagnóstico de cardiopatía congénita. Se tomaron 3 mL de sangre al binomio madre-hijo y se realizó ELISA de micropartículas para anticuerpos IgG e IgM contra la rubéola. Resultados: se estudiaron 80 pacientes con edad de tres meses; 56 % era del sexo femenino. Las cardiopatías congénitas más frecuentes fueron las comunicaciones interventricular (28.5 %) y la interauricular (17.5 %). La mediana de la edad materna fue de 28 años; 1.25 % de las madres tuvo antecedente de enfermedad febril y exantema durante el embarazo. Se detectaron siete casos (8.75 %) de infección perinatal por el virus de la rubéola, tres cumplieron el criterio de síndrome de rubéola congénita y cuatro de cardiopatía. Conclusiones: se sugiere buscar rubéola congénita en los recién nacidos y lactantes con cardiopatías, como una estrategia para detectar los casos no obvios.

  7. Educational and Demographic Profile: Contra Costa County.

    ERIC Educational Resources Information Center

    California Postsecondary Education Commission, 2004

    2004-01-01

    This profile uniquely presents a variety of educational and socioeconomic information for Contra Costa County, nearby counties, and the state. The profile highlights the relationship between various factors that affect the economic well-being of individuals and communities. This presentation of information provides a framework for enhanced…

  8. Viruses

    USDA-ARS?s Scientific Manuscript database

    Lytic bacteriophages, viruses which infect and lyse bacterial cells, can provide a natural method to reduce bacterial pathogens on produce commodities. The use of multi-phage cocktails is most likely to be effective against bacterial pathogens on produce commodities, and minimize the development of...

  9. CONTRA: copy number analysis for targeted resequencing

    PubMed Central

    Li, Jason; Lupat, Richard; Amarasinghe, Kaushalya C.; Thompson, Ella R.; Doyle, Maria A.; Ryland, Georgina L.; Tothill, Richard W.; Halgamuge, Saman K.; Campbell, Ian G.; Gorringe, Kylie L.

    2012-01-01

    Motivation: In light of the increasing adoption of targeted resequencing (TR) as a cost-effective strategy to identify disease-causing variants, a robust method for copy number variation (CNV) analysis is needed to maximize the value of this promising technology. Results: We present a method for CNV detection for TR data, including whole-exome capture data. Our method calls copy number gains and losses for each target region based on normalized depth of coverage. Our key strategies include the use of base-level log-ratios to remove GC-content bias, correction for an imbalanced library size effect on log-ratios, and the estimation of log-ratio variations via binning and interpolation. Our methods are made available via CONTRA (COpy Number Targeted Resequencing Analysis), a software package that takes standard alignment formats (BAM/SAM) and outputs in variant call format (VCF4.0), for easy integration with other next-generation sequencing analysis packages. We assessed our methods using samples from seven different target enrichment assays, and evaluated our results using simulated data and real germline data with known CNV genotypes. Availability and implementation: Source code and sample data are freely available under GNU license (GPLv3) at http://contra-cnv.sourceforge.net/ Contact: Jason.Li@petermac.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22474122

  10. 28 CFR 601.1 - Jurisdiction of the Independent Counsel: Iran/Contra.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Iran/Contra. 601.1 Section 601.1 Judicial Administration OFFICES OF INDEPENDENT COUNSEL, DEPARTMENT OF JUSTICE JURISDICTION OF THE INDEPENDENT COUNSEL: IRAN/CONTRA § 601.1 Jurisdiction of the Independent Counsel: Iran/Contra. (a) The Independent Counsel. Iran/Contra has jurisdiction to investigate to the...

  11. 28 CFR 601.1 - Jurisdiction of the Independent Counsel: Iran/Contra.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Iran/Contra. 601.1 Section 601.1 Judicial Administration OFFICES OF INDEPENDENT COUNSEL, DEPARTMENT OF JUSTICE JURISDICTION OF THE INDEPENDENT COUNSEL: IRAN/CONTRA § 601.1 Jurisdiction of the Independent Counsel: Iran/Contra. (a) The Independent Counsel. Iran/Contra has jurisdiction to investigate to the...

  12. 28 CFR 601.1 - Jurisdiction of the Independent Counsel: Iran/Contra.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Iran/Contra. 601.1 Section 601.1 Judicial Administration OFFICES OF INDEPENDENT COUNSEL, DEPARTMENT OF JUSTICE JURISDICTION OF THE INDEPENDENT COUNSEL: IRAN/CONTRA § 601.1 Jurisdiction of the Independent Counsel: Iran/Contra. (a) The Independent Counsel. Iran/Contra has jurisdiction to investigate to the...

  13. 28 CFR 601.1 - Jurisdiction of the Independent Counsel: Iran/Contra.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Iran/Contra. 601.1 Section 601.1 Judicial Administration OFFICES OF INDEPENDENT COUNSEL, DEPARTMENT OF JUSTICE JURISDICTION OF THE INDEPENDENT COUNSEL: IRAN/CONTRA § 601.1 Jurisdiction of the Independent Counsel: Iran/Contra. (a) The Independent Counsel. Iran/Contra has jurisdiction to investigate to the...

  14. 28 CFR 601.1 - Jurisdiction of the Independent Counsel: Iran/Contra.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: Iran/Contra. 601.1 Section 601.1 Judicial Administration OFFICES OF INDEPENDENT COUNSEL, DEPARTMENT OF JUSTICE JURISDICTION OF THE INDEPENDENT COUNSEL: IRAN/CONTRA § 601.1 Jurisdiction of the Independent Counsel: Iran/Contra. (a) The Independent Counsel. Iran/Contra has jurisdiction to investigate to the...

  15. Trombosis primaria de la descendente anterior en un paciente con síndrome de anticuerpos antifosfolípidos.

    PubMed

    Acuña-Valerio, Jorge; Peña-Duque, Marco Antonio; Contreras-Villaseñor, Álvaro

    2017-01-01

    El síndrome de anticuerpos antifosfolípidos es una situación clínica y bioquímica heterogénea. Presentamos el caso de un varón joven con antecedente de tromboembolia venosa que se presentó en esta ocasión por dolor precordial, con elevación del ST en el electrocardiograma. Fue llevado a sala de angiografía para realizar angioplastia primaria y se observó una oclusión total ostial de la descendente anterior. Se realizó aspiración manual del trombo. No se realizó angioplastia con balón ni stent. En la angiografía de control a las 48 horas se observó ausencia de trombo y de placas aterosclerosas, lo cual se corroboró mediante ultrasonido intracoronario. Antiphospholipid antibody syndrome is a heterogeneous clinical and biochemical entity. We present the case of a young male with history of venous thromboembolism. This time he presents because of chest ischemic pain associated with ST segment elevation. He was taken to the cath lab to perform a primary percutaneous coronary intervention and a total occlusion of the left anterior descending artery was noted. Successful thrombus aspiration was performed. No stent was deployed. He was taken to the cath lab for a second look angiography and no atherosclerotic lesions were observed, which was confirmed by intravascular ultrasound.

  16. Contra Costa Community College District Transfer Education Report.

    ERIC Educational Resources Information Center

    Contra Costa Community Coll. District, Martinez, CA.

    This research report from Contra Costa Community College District (CCCCD), California, summarizes relevant findings from assessments of the performance of students receiving transfer education, and CCCCD's progress in meeting its Partnership for Excellence (PFE) goals in this area. Findings reported include the following: (1) Student Goal…

  17. Contra Costa Community College District Institutional Effectiveness Report.

    ERIC Educational Resources Information Center

    Contra Costa Community Coll. District, Martinez, CA. Office of District Research.

    This document addresses the 2000 institutional effectiveness report for Contra Costa Community College District. The document discusses the following ten indicators which are directly aligned with Partnership for Excellence (PFE) 2005-2006 Goals: (1) Student Goal Attainment; (2) Course Success/ Persistence/ Retention Rates; (3) Certificate/ Degree…

  18. The Constitution Today: Lessons of the Iran-Contra Affair.

    ERIC Educational Resources Information Center

    Bobbitt, Philip

    1988-01-01

    Presents a speech which discusses private funding for government operations, secret policies, and the doctrine of plausible denial. States that the Iran-Contra affair illustrates the failure of the educational system to educate patriotic, intelligent persons in the nation's most fundamental constitutional arrangements, such as the appropriations…

  19. First 5 Contra Costa Report on Parent Involvement. Final Report

    ERIC Educational Resources Information Center

    Duffy, Sarah; Induni, Marta; Moiduddin, Emily

    2010-01-01

    This report presents the results of the Parental Involvement in Pre-School Telephone Interview study completed by Mathematica Policy Research for the First 5 Contra Costa Children and Families Commission. Parent involvement in children's preschool programs and learning experiences is proven to be positively associated with cognitive, academic,…

  20. Contra Costa Community College District Vocational Education Report.

    ERIC Educational Resources Information Center

    Contra Costa Community Coll. District, Martinez, CA. Office of District Research.

    This report provides an overview of the legislative and administrative context of Vocational Education and profiles Vocational Education nationally, statewide, and at Contra Costa Community College District (CCCCD). Certain national trends, economic trends, and labor market trends have created implications for vocational and technical education in…

  1. Inventory of Vocational Programs in Alameda and Contra Costa Counties.

    ERIC Educational Resources Information Center

    Banaghan, William F., Comp.

    The document presents a directory of vocationally oriented educational programs which already exist in Alameda and Contra Costa Counties, California. It is hoped that the inventory will permit improved planning for future programs and greater utilization and coordination of present ones. Listings include: Directory of Educational Agencies, with…

  2. Assurance through Performance: The Iran-Contra Hearings as Celebration.

    ERIC Educational Resources Information Center

    Rogers, Richard A.

    Drawing on Michael Halloran's genre of public proceedings, the Iran-contra hearings can be viewed from a celebratory or epideictic perspective, with several conceptualizations of the genre combined to illuminate the functions of the hearings. The primary function of the hearings, at least from an epideictic viewpoint, was the reassurance of the…

  3. Epidemiology and neurological complications of infection by the Zika virus: a new emerging neurotropic virus.

    PubMed

    Carod-Artal, Francisco J

    2016-04-01

    Introduccion. El actual brote epidemico por virus Zika se inicio en 2015 y en la actualidad afecta a 31 paises y territorios en America. Se revisan los aspectos epidemiologicos y clinicos asociados con la infeccion por virus Zika. Desarrollo. Desde 2007, 55 paises de America, Asia, Africa y Oceania han detectado transmision local del virus. La actual epidemia ha afectado a casi 1,5 millones de personas en Brasil. El 80% de los casos son asintomaticos. La enfermedad por virus Zika cursa con fiebre, exantema maculopapular, artralgias y conjuntivitis no purulenta. Los sintomas suelen ser autolimitados y duran una semana. Se ha descrito un aumento de la incidencia de los casos de microcefalia, lesiones retinianas y sindrome de Guillain-Barre asociados con el virus Zika. El sindrome de Guillain-Barre asociado al Zika en la Polinesia es una variante axonal motora pura. El ARN del virus Zika se ha identificado en muestras de tejido cerebral, placenta y liquido amniotico de niños con microcefalia y en perdidas fetales de mujeres infectadas por Zika durante el embarazo. Se recomienda realizar la prueba de reaccion en cadena de la polimerasa mediante transcriptasa inversa para detectar ARN virico y pruebas serologicas (IgM ELISA y anticuerpos neutralizantes) para confirmar una infeccion por Zika. El diagnostico diferencial incluye la infeccion por virus dengue y chikungunya. Conclusiones. Existe un conocimiento limitado sobre los mecanismos patogenicos implicados y las consecuencias a largo plazo de la infeccion por virus Zika en adultos y recien nacidos.

  4. Tests of a Contra-propeller for Aircraft

    NASA Technical Reports Server (NTRS)

    Benson, William M

    1938-01-01

    Tests of an 8-blade contra-propeller of 32-inch diameter in combination with a 4-inch, 36-inch diameter adjustable pitch, metal propeller at pitch setting of 15, 25, 35, and 45 degrees at 0.75 R were made. The tests showed a significant increase in effective thrust of the combination over that of the propeller alone for value V/nD somewhat below those for maximum efficiency and without a corresponding increase of power absorbed. From 1/2 percent to 2-1/2 percent in propulsive efficiency was thus gained in this range. In all but one case, however, the peak propulsive efficiency of the combination was found to be from 1 to 2 percent less than that of the propeller alone. Counter torque on the contra-propeller amounted to about 50 percent of the propeller torque.

  5. Contra Costa Community College District Enrollment Report, October 2000.

    ERIC Educational Resources Information Center

    Contra Costa Community Coll. District, Martinez, CA.

    This report analyzes enrollment figures for Contra Costa Community College District in 2000-2001. The data for 2002 is compared with the data from 1997-1998, 1998-1999, and 1999-2000. The following are some of the major findings of the report: (1) both resident and non-resident FTES totals have increased over 1995/1996 levels; (2) the growth…

  6. Politics or Economics? International Migration during the Nicaraguan Contra War*

    PubMed Central

    Lundquist, Jennifer H.; Massey, Douglas S.

    2010-01-01

    The issue of whether Central Americans in the United States are ‘political’ or ‘economic’ migrants has been widely debated, yet little empirical research has informed the controversy. Earlier studies have relied primarily on cross-sectional aggregate data. In order to overcome these limitations we draw on recent surveys conducted in five Nicaraguan communities by the Latin American Migration Project. Using retrospective data, we reconstruct a history of a family’s migration to the United States and Costa Rica from the date of household formation to the survey date and link these data to national-level data on GDP and Contra War violence. While out migration to both Costa Rica and the United States is predicted by economic trends, US-bound migration was more strongly linked to the level of Contra War violence independent of economic motivations, especially in an interactive model that allows for a higher wartime effect of social networks. We conclude that elevated rates of Nicaraguan migration to the United States during the late 1980s and early 1990s were a direct result of the US-Contra intervention. The approach deployed here – which relates to the timing of migration decisions to macro-level country trends – enables us to address the issue of political versus economic motivations for migration with more precision than prior work. PMID:20852719

  7. The theory of contra-vanes applied to the propeller

    NASA Technical Reports Server (NTRS)

    Betz, Albert

    1939-01-01

    The optimum circulation distribution and hence the maximum theoretical thrust obtainable for contra-vanes fitted behind propellers is markedly dependent on the number of guide vanes. The outer portion of the vanes, even if projecting considerably beyond the edge of the propeller slipstream, still contribute appreciably to this theoretical gain of thrust. But, owing to the always existing friction of the vanes, the limit of the optimum vane length lies at relatively small diameters. A large hub unloads the vanes. Hence, the guide vanes are best attached to suitable parts of the bodies which would, in any case, be subjected to the slipstream.

  8. The International Reference Sphere of the Earth: PRO and CONTRA

    NASA Astrophysics Data System (ADS)

    Grafarend, E. W.

    2003-04-01

    In Gravitostatics, Electrostatics and Magnetostatics the scalar-valued potential external to the Earth Reference Body is expanded in scalar-valued external spherical harmonics. Such a harmonic space L^2(S^2_R) with respect to the International Reference Sphere S^2_R is analyzed. We review the physical theory of how to determine the Mean Sphere of the Earth. In particular, we discuss the PRO and CONTRA of such a reference sphere which thanks to Earth rotation is physically not admissible. A physical admissible reference figure is the International Reference Ellipsoid, an equipotential surface in the Somigliana-Pizzetti reference potential field.

  9. Ebola Virus and Marburg Virus

    MedlinePlus

    Diseases and Conditions Ebola virus and Marburg virus By Mayo Clinic Staff Ebola virus and Marburg virus are related viruses that cause hemorrhagic ... Africa, where sporadic outbreaks have occurred for decades. Ebola virus and Marburg virus live in animal hosts, ...

  10. 75 FR 13301 - Los Vaqueros Reservoir Expansion, Contra Costa and Alameda Counties, CA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-19

    ... water supply reliability. A 60 TAF expansion option would expand the reservoir to 160 TAF. This second option would primarily be operated to improve Contra Costa Water District (CCWD) dry year water supply... Environmental Policy Act Federal lead agency, and the Contra Costa Water District, as the California...

  11. Crack cocaine use among persons with tuberculosis--Contra Costa County, California, 1987-1990.

    PubMed

    1991-07-26

    From January 1, 1987, through June 30, 1990, 44 cases of tuberculosis (TB) occurred among residents of Contra Costa County, California, who were known to use crack cocaine. To investigate a possible association between crack cocaine use and TB, local health officials conducted a retrospective study of TB cases among residents of Contra Costa County.

  12. [Contra-indications to sports activities in cardiac patients].

    PubMed

    Rivière, A; Denolin, H

    1984-04-01

    The cardiologist is faced with the problem of eliminating a subject with heart disease from a sports competition and of prescribing beneficial physical activity to patients with heart disease. The difficulty in the prescription (or contra-indication) is due to the need for an individual assessment of each case. Several general rules can be proposed for cases of heart disease with a high risk of mortality or with a poor haemodynamic status. In most cases, the beneficial or detrimental effect can not be predicted. In this review, the authors present various approaches, based on data from the literature, for different types of heart disease and for different sports. They conclude that each case requires a thorough investigation in order to reduce the number of victims of the sports stadium.

  13. Contra Costa County's one-year experience with gasohol

    SciTech Connect

    Gibbs, L.M.; Gilbert, B.J.

    1981-01-01

    Starting August 1, 1979, a one-year gasohol test was conducted by Contra Costa County. A total of 30 county pool cars were on test - 15 on gasohol and 15 similar cars on gasoline as a control group. Findings were as follows. There were no fuel-related maintenance problems in either the gasohol or gasoline groups of cars. Cool weather driveability for the gasohol cars was the same or better than gasoline cars. No vapor lock or other hot driveability problems were reported for either fuel. Fuel economy of the gasohol cars was about 5% poorer than that of the gasoline cars. Fuel system deposits with gasohol were increased and differed in character compared to gasoline. Also, the gasohol carburetors showed more inlet needle valve tip wear. However, to date, the observed deposits and wear with gasohol have not caused any apparent problems.

  14. Performance and internal flow of sirocco fan using contra-rotating rotors

    NASA Astrophysics Data System (ADS)

    Fukutomi, J.; Shigemitsu, T.; Yasunobu, T.

    2008-03-01

    A sirocco fan using contra-rotating rotors in which an inner rotor is settled inside the sirocco fan rotor and each rotor rotates in an opposite direction was proposed for the purpose of getting the higher pressure and making the structure of a sirocco fan more compact. If the high discharge pressure is obtained with the adoption of the contra-rotating rotors, it could be used for various purposes. Pressure coefficient of a sirocco fan with contra-rotating rotors is 2.5 times as high as the conventional sirocco fan and the maximum efficiency point of contra-rotating rotors shifts to larger flow rate than a conventional sirocco fan. On the other hand, it was clarified from the flow measurement results that circumferential velocity component at the outlet of the outer rotor of contra-rotating rotors becomes larger than a conventional one. In the present paper, the performance of a conventional sirocco fan and a sirocco fan with contra-rotating rotors are shown and the internal flow field at the outlet of outer rotor of both cases is clarified. Then, the effect of different kind of contra-rotating rotors on the performance and internal flow field is investigated and the rotor design with higher performance would be discussed.

  15. Hydraulic Model Investigation: Walnut Creek Flood-Control Project Contra Costa County, California.

    DTIC Science & Technology

    1987-10-01

    TECHNICAL REPORT HL-87-14 WALNUT CREEK FLOOD-CONTROL PROJECT CONTRA COSTA COUNTY, CALIFORNIA Hydraulic Model Investigation by W. G. Davis O11C tLE...34’ : AA Ii iA e d S O a :::: SCALE IN MILES 5 0 5 10 Figure 1. Vicinity map 4~ 4.. %- . " . " %____ WALNUT CREEK FLOOD-CONTROL PROJECT CONTRA COSTA COUNTY...Pleasant Hi-1, nd Martinez, California, on its way to the Suisin Bay. All of th.e planned imcrovements are located in Contra Costa County, California

  16. Heartland Virus

    MedlinePlus

    ... Vector-Borne Diseases (DVBD) NCEZID Share Compartir Heartland virus On this Page What is Heartland virus? How ... Do I Need to Know? What is Heartland virus? Heartland virus belongs to a family of viruses ...

  17. Proposed Expansion of Acme Landfill Operations, Contra Costa, County, California. Volume 1.

    DTIC Science & Technology

    1983-06-01

    for example, plastic beverage bottles, cardboard, wood, yardwastes, textiles , rubber, and leather. In addition to traditional activities, a central...a 6000-foot-long dredged channel. The 200-acre parcel is crossed with a number of drainage ditches, constructed by the Contra Costa Mosquito ...incoming flow at the high tide. It is the only point of discharge for flood water and is maintained by the Contra Costa Mosquito Abatement District

  18. Contra-Rotating Open Rotor Tone Noise Prediction

    NASA Technical Reports Server (NTRS)

    Envia, Edmane

    2014-01-01

    Reliable prediction of contra-rotating open rotor (CROR) noise is an essential element of any strategy for the development of low-noise open rotor propulsion systems that can meet both the community noise regulations and cabin noise limits. Since CROR noise spectra exhibit a preponderance of tones, significant efforts have been directed towards predicting their tone content. To that end, there has been an ongoing effort at NASA to assess various in-house open rotor tone noise prediction tools using a benchmark CROR blade set for which significant aerodynamic and acoustic data have been acquired in wind tunnel tests. In the work presented here, the focus is on the nearfield noise of the benchmark open rotor blade set at the cruise condition. Using an analytical CROR tone noise model with input from high-fidelity aerodynamic simulations, tone noise spectra have been predicted and compared with the experimental data. Comparisons indicate that the theoretical predictions are in good agreement with the data, especially for the dominant tones and for the overall sound pressure level of tones. The results also indicate that, whereas the individual rotor tones are well predicted by the combination of the thickness and loading sources, for the interaction tones it is essential that the quadrupole source is also included in the analysis.

  19. Flame characteristics of a NASA contra swirler module

    NASA Technical Reports Server (NTRS)

    Thompson, D.; Chigier, N. A.; Ungut, A.

    1977-01-01

    The structure of unconfined flames stabilized on a NASA contra-swirl can has been examined. The structure depends on reference velocity and fuel-air ratio, and photographic illustrations of representative examples of each flame type are shown. A highly compact flame is obtained over a narrow band of fuel-air ratios, within the total range over which flames may be stabilized, at high reference velocity (27.8 m/s). The compact structure can only be obtained with careful fuel nozzle location. Chemical concentration profiles, temperature profiles and sodium chloride seeding experiments all confirm the visual impression of compactness. A flame with 50% greater fuel throughput has a much less compact structure, which is reflected in lower maximum temperature, much more complex chemical concentration distributions and a more diffuse recirculation boundary as observed by sodium chloride seeding than in the compact flame. Each of these flames has not only an evident axial recirculation core but also a toroidal recirculation region over the bluff region between the inner and outer swirlers. In contrast, laser Doppler velocimetry measurements carried out on a flame with lower reference velocity (5.65 m/s) do not indicate the presence of a secondary recirculation region in this flame.

  20. Contra-Rotating Open Rotor Tone Noise Prediction

    NASA Technical Reports Server (NTRS)

    Envia, Edmane

    2014-01-01

    Reliable prediction of contra-rotating open rotor (CROR) noise is an essential element of any strategy for the development of low-noise open rotor propulsion systems that can meet both the community noise regulations and the cabin noise limits. Since CROR noise spectra typically exhibits a preponderance of tones, significant efforts have been directed towards predicting their tone spectra. To that end, there has been an ongoing effort at NASA to assess various in-house open rotor tone noise prediction tools using a benchmark CROR blade set for which significant aerodynamic and acoustic data had been acquired in wind tunnel tests. In the work presented here, the focus is on the near-field noise of the benchmark open rotor blade set at the cruise condition. Using an analytical CROR tone noise model with input from high-fidelity aerodynamic simulations, detailed tone noise spectral predictions have been generated and compared with the experimental data. Comparisons indicate that the theoretical predictions are in good agreement with the data, especially for the dominant CROR tones and their overall sound pressure level. The results also indicate that, whereas individual rotor tones are well predicted by the linear sources (i.e., thickness and loading), for the interaction tones it is essential that the quadrupole sources be included in the analysis.

  1. Contra-lateral needling in the treatment of hemiplegia due to acute ischemic stroke.

    PubMed

    Gao, Huanmin; Gao, Xia; Liang, Guixia; Ma, Ben-Xu

    2012-01-01

    Contra-lateral Needling, a traditional acupuncture technique, means contra-lateral acupuncture by inserting needles into acupoints on the relative healthy side of the body opposite to the injured side to treat diseases such as apoplexy with high efficacy. However, there are not many well-designed and controlled clinical evidences found in the literature. Therefore the present study was designed to assess its therapeutic responses in the treatment of hemiplegia due to acute ischemic stroke. A clinical study was conducted with randomly selected 106 patients who have acute ischemic stroke confirmed by MRI. The subjects were assigned into 3 groups: 45 in the contra-lateral needling group received acupuncture on the unaffected limbs; 45 in the conventional acupuncture group received acupuncture on the hemiplegic limbs; and 16 in the non-acupuncture group received the similar medical and nursing care as subjects in other two groups but no acupuncture treatment. Acupuncture was given daily for 45 minutes for 30 days. The clinical therapeutic responses rate, Neurological Deficits Score (NDS), Modified Barthel Index (MBI) and Fugl-Meger Assertion (FMA) were used to evaluate the effectiveness of 30 days treatment. The therapeutic response rate of the contra-lateral needling group was 46.67%, while 31.11% in the conventional acupuncture group, and 18.75% in the non-acupuncture group. The NDS of Contra-lateral needling group decreased more significantly than that of the conventional acupuncture group (p < 0.01). The study also found that the MBI and FMA of Contra-lateral needling group increased more significantly than those of the conventional acupuncture group (p < 0.01, respectively). Contra-lateral needling might be more effective than the conventional acupuncture in the treatment of hemiplegia due to acute ischemic stroke in terms of increasing the recovery of neurological functions, promoting ADL (activities for daily living) rehabilitation and the limbs motor function.

  2. Internal Flow of Contra-Rotating Small Hydroturbine at Off- Design Flow Rates

    NASA Astrophysics Data System (ADS)

    SHIGEMITSU, Toru; TAKESHIMA, Yasutoshi; OGAWA, Yuya; FUKUTOMI, Junichiro

    2016-11-01

    Small hydropower generation is one of important alternative energy, and enormous potential lie in the small hydropower. However, efficiency of small hydroturbines is lower than that of large one. Then, there are demands for small hydroturbines to keep high performance in wide flow rate range. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance. In this research, performance of the contra-rotating small hydroturbine with 60mm casing diameter was investigated by an experiment and numerical analysis. Efficiency of the contra-rotating small hydroturbine was high in pico-hydroturbine and high efficiency could be kept in wide flow rate range, however the performance of a rear rotor decreased significantly in partial flow rates. Then, internal flow condition, which was difficult to measure experimentally, was investigated by the numerical flow analysis. Then, a relation between the performance and internal flow condition was considered by the numerical analysis result.

  3. Sediment transport and deposition, Walnut and Pacheco Creeks, Contra Costa County, California, August 1965-April 1970

    USGS Publications Warehouse

    Porterfield, George

    1972-01-01

    Average annual sediment discharge in Pacheco Creek basin, Contra Costa County, Calif., was larger during August 1965-April 1970 than the historical annual sediment discharge (1909-62) by a factor of about 1.3. This increas in sediment discharge is attributed primarily to an increased frequency of peak streamflows and to a larger average annual streamflow during the 1965-70 period.

  4. Hunger in the Midst of Affluence: Task Force Combats Hunger in Contra Costa County.

    ERIC Educational Resources Information Center

    Fujii, Mary Lavender

    1994-01-01

    Research conducted by the Hunger Task Force in Contra Costa County (California) revealed a significant increase in the number of families, especially with young children, who live in poverty and who are going hungry. A food stamp outreach program, a countywide school breakfast program, and food distribution programs have been initiated. (LP)

  5. Enhancing Ethos: The Role of Epideictic at the Iran-Contra Hearings.

    ERIC Educational Resources Information Center

    Gilbert, David

    A critique predicated primarily on aesthetic considerations can show the potential a speech has to move an audience, but gauging a speech's actual effects on the audience is more difficult. A case in point is the United States Congressional investigation of the Iran-Contra scandal. Government officials and businessmen sold arms to Iran in exchange…

  6. Hunger in the Midst of Affluence: Task Force Combats Hunger in Contra Costa County.

    ERIC Educational Resources Information Center

    Fujii, Mary Lavender

    1994-01-01

    Research conducted by the Hunger Task Force in Contra Costa County (California) revealed a significant increase in the number of families, especially with young children, who live in poverty and who are going hungry. A food stamp outreach program, a countywide school breakfast program, and food distribution programs have been initiated. (LP)

  7. Evaluation of the Third Year of Operation of the Contra Costa College Mobile Counseling Center.

    ERIC Educational Resources Information Center

    Edwards, Howard

    During 1971, the third year of operation of Contra Costa College's (California) mobile counseling unit, the priorities established for that program were (a) to make the mobile counseling unit and program as widely known in the community as possible, and (b) to concentrate on the services to the client. The counseling unit and program were…

  8. Evaluation of the Second Year of Operation of the Contra Costa Mobile Counseling Center.

    ERIC Educational Resources Information Center

    Gordon, Anthony T.

    Second year operations of this mobile center have validated many of the assumptions on which it was founded (see ED 031 243), including a reduction in the communications gap between Contra Costa College and the community at large. While attempts to compare this year's results with last year's can be considered premature, some findings may be of…

  9. West Contra Costa Unified School District Assessment and Improvement Plan: Facilities Management.

    ERIC Educational Resources Information Center

    2001

    This report analyzes the conditions of school facilities in Contra Costa Unified School District, California. The district had been prohibited from participating in the state's school facilities funding program because of a very heavy debt burden and near-bankruptcy of the district. The report begins by summarizing findings in the areas of…

  10. Evaluation of the First Year of Operation of the Contra Costa College Mobile Counseling Center.

    ERIC Educational Resources Information Center

    Gordon, Anthony T.

    Contra Costa College tried several ways to reach potential students who were unaware that they were eligible or even that the college had anything to offer them. Articulation with high schools, contacts with other agencies, and the mass media were of little help. The idea of a central, off-campus counseling center was abandoned in favor of the…

  11. A Further Review of the California State University's Contra Costa Center. Commission Report 89-9.

    ERIC Educational Resources Information Center

    California State Postsecondary Education Commission, Sacramento.

    A follow-up report on the California State University's Contra Costa Center, a proposed permanent off-campus center, is presented. The California Postsecondary Education Commission approved the original proposal in 1987, contingent on finding solutions to concerns about transportation access and services to disadvantaged students. The university…

  12. ECHO virus

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/001340.htm ECHO virus To use the sharing features on this page, please enable JavaScript. Enteric cytopathic human orphan (ECHO) viruses are a group of viruses that can lead ...

  13. Virus Carcinogenesis

    DTIC Science & Technology

    1961-01-01

    viruses are capable of inducing cancer, it is obvious that virus carcinogenesis cannot be considered in an isolated fashion, without some reference to...intradermal inoculations of vaccinia virus . One of the viruses most widely investigated with respect to quantitative dose- response relationships is the...than the rule. Figure 6 shows the type of deviation most commonly observed with viruses of infectious diseases. VIRUS CARCINOGENESIS 131 It is a

  14. Foodborne viruses

    USDA-ARS?s Scientific Manuscript database

    Testing for human pathogenic viruses in foods represents a formidable task requiring the extraction, concentration, and assay of a host of viruses from a wide range of food matrices. The enteric viruses, particularly genogroup I and II (GI and GII) noroviruses and hepatitis A virus, are the princip...

  15. Digital database of microfossil localities in Alameda and Contra Costa Counties, California

    USGS Publications Warehouse

    McDougall, Kristin; Block, Debra

    2014-01-01

    The eastern San Francisco Bay region (Contra Costa and Alameda Counties, California) is a geologically complex area divided by faults into a suite of tectonic blocks. Each block contains a unique stratigraphic sequence of Tertiary sediments that in most blocks unconformably overlie Mesozoic sediments. Age and environmental interpretations based on analysis of microfossil assemblages are key factors in interpreting geologic history, structure, and correlation of each block. Much of this data, however, is distributed in unpublished internal reports and memos, and is generally unavailable to the geologic community. In this report the U.S. Geological Survey microfossil data from the Tertiary sediments of Alameda and Contra Costa counties are analyzed and presented in a digital database, which provides a user-friendly summary of the micropaleontologic data, locality information, and biostratigraphic and ecologic interpretations.

  16. Inventing Viruses.

    PubMed

    Summers, William C

    2014-11-01

    In the nineteenth century, "virus" commonly meant an agent (usually unknown) that caused disease in inoculation experiments. By the 1890s, however, some disease-causing agents were found to pass through filters that retained the common bacteria. Such an agent was called "filterable virus," the best known being the virus that caused tobacco mosaic disease. By the 1920s there were many examples of filterable viruses, but no clear understanding of their nature. However, by the 1930s, the term "filterable virus" was being abandoned in favor of simply "virus," meaning an agent other than bacteria. Visualization of viruses by the electron microscope in the late 1930s finally settled their particulate nature. This article describes the ever-changing concept of "virus" and how virologists talked about viruses. These changes reflected their invention and reinvention of the concept of a virus as it was revised in light of new knowledge, new scientific values and interests, and new hegemonic technologies.

  17. Impact of contra-lateral breast reshaping on mammographic surveillance in women undergoing breast reconstruction following mastectomy for breast cancer.

    PubMed

    Nava, Maurizio B; Rocco, Nicola; Catanuto, Giuseppe; Falco, Giuseppe; Capalbo, Emanuela; Marano, Luigi; Bordoni, Daniele; Spano, Andrea; Scaperrotta, Gianfranco

    2015-08-01

    The ultimate goal of breast reconstruction is to achieve symmetry with the contra-lateral breast. Contra-lateral procedures with wide parenchymal rearrangements are suspected to impair mammographic surveillance. This study aims to evaluate the impact on mammographic detection of mastopexies and breast reductions for contralateral adjustment in breast reconstruction. We retrospectively evaluated 105 women affected by uni-lateral breast cancer who underwent mastectomy and immediate two-stage reconstruction between 2002 and 2007. We considered three groups according to the contra-lateral reshaping technique: mastopexy or breast reduction with inferior dermoglandular flap (group 1); mastopexy or breast reduction without inferior dermoglandular flap (group 2); no contra-lateral reshaping (group 3). We assessed qualitative mammographic variations and breast density in the three groups. Statistically significant differences have been found when comparing reshaped groups with non reshaped groups regarding parenchymal distortions, skin thickening and stromal edema, but these differences did not affect cancer surveillance. The surveillance mammography diagnostic accuracy in contra-lateral cancer detection was not significantly different between the three groups (p = 0.56), such as the need for MRI for equivocal findings at mammographic contra-lateral breast (p = 0.77) and the need for core-biopsies to confirm mammographic suspect of contra-lateral breast cancer (p = 0.90). This study confirms previous reports regarding the safety of mastopexies and breast reductions when performed in the setting of contra-lateral breast reshaping after breast reconstruction. Mammographic accuracy, sensitivity and specificity are not affected by the glandular re-arrangement. These results provide a further validation of the safety of current reconstructive paradigms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Chemical quality of ground water in San Joaquin and part of Contra Costa Counties, California

    USGS Publications Warehouse

    Sorenson, Stephen K.

    1981-01-01

    Chemical water-quality conditions were investigated in San Joaquin and part of Contra Costa Counties by canvassing available wells and sampling water from 324 representative wells. Chemical water types varied, with 73 percent of the wells sampled containing either calcium-magnesium bicarbonate, or calcium-sodium bicarbonate type water. Substantial areas contain ground water exceeding water-quality standards for boron, manganese, and nitrate. Trace elements, with the exception of boron and manganese, were present in negligible amounts. (USGS)

  19. Chikungunya Virus

    MedlinePlus

    ... is key! Prevent Infection. Use mosquito repellent. Chikungunya Virus Distribution Chikungunya in the U.S. What's New Surveillance ... Clinical Challenge For Travelers CDC Travelers' Health Chikungunya Virus Home Prevention Transmission Symptoms & Treatment Geographic Distribution Chikungunya ...

  20. Zika Virus

    MedlinePlus

    Zika is a virus that is spread mostly by mosquitoes. A pregnant mother can pass it to ... through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, ...

  1. Hepadna viruses

    SciTech Connect

    Robinson, W.; Koike, K.; Will, H.

    1987-01-01

    This book examines the molecular biology, disease pathogenesis, epidemiology, and clinical features of hepadna and other viruses with hepatic tropism and outlines future directions and approaches for their management. The volume's six sections provide a review of the various features, mechanisms, and functions of these viruses, ranging from hepadna virus replication and regulation of gene expression to the structure and function of hepadna-virus gene products.

  2. Virus maturation.

    PubMed

    Delgui, Laura R; Rodríguez, José F

    2013-01-01

    The formation of infectious virus particles is a highly complex process involving a series of sophisticated molecular events. In most cases, the assembly of virus structural elements results in the formation of immature virus particles unable to initiate a productive infection. Accordingly, for most viruses the final stage of the assembly pathway entails a set of structural transitions and/or biochemical modifications that transform inert precursor particles into fully infectious agents. In this chapter, we review the most relevant maturation mechanisms involved in the generation of infectious virions for a wide variety of viruses.

  3. A ZIF-71 Hollow Fiber Membrane Fabricated by Contra-Diffusion.

    PubMed

    Huang, Kang; Li, Qianqian; Liu, Gongping; Shen, Jie; Guan, Kecheng; Jin, Wanqin

    2015-08-05

    As a subclass of metal-organic framework materials, zeolitic imidazolate frameworks (ZIFs) have exhibited great potential for numerous applications because of their special three-dimensional structure. Up to now, utilizing ZIF membranes for liquid separations is still limited because it is very difficult to select suitable materials and to fabricate integrated membranes. In this work, a modified contra-diffusion method was carried out to prepare ZIF-71 hollow fiber membranes. The metals Zn(2+) and the organic links imidazole would meet and react on the interface of ceramic hollow fiber through diffusion. The as-prepared ZIF-71 membrane exhibits good performance in separation of ethanol-water mixtures.

  4. Unsteady Aerodynamic Response of Oscillating Contra-Rotating Annular Cascades Part II: Numerical Study

    NASA Astrophysics Data System (ADS)

    Nishino, Ryohei; Namba, Masanobu

    The unsteady aerodynamic force and work for contra-rotating annular cascades of oscillating blades are numerically investigated. A comparison among frequency components of unsteady blade loadings on oscillating blades and stationary blades in relative rotational motion is conducted. It is proved that the state of generated acoustic duct mode of the lowest order is a key factor governing the aeroacoustic interaction between the blade rows. The effect of the neighboring blade row on the aerodynamic force and work is never small and will make substantial modifications to the flutter boundaries of an isolated blade row.

  5. An epidemiologic study of unreported cutaneous malignant melanoma among residents of Alameda and Contra Costa Counties

    SciTech Connect

    West, D.W.; Whittemore, A.S. Stanford Univ., CA ); Zippin, C.; Lum, D. ); Holly, E. )

    1991-11-12

    Because of a reported excess of cutaneous malignant melanoma cases at the Lawrence Livermore National Laboratory during the 1970's this study was funded to: determine if the number of cases in Alameda and Contra Costa Counties may have been underreported during 1973--1985 (this is the comparison group used to report an excess of melanoma at the LLNL), and determine if melanoma cases at the LLNL had different melanomas from the comparison population in terms of tumor thickness and therefore aggressiveness of tumors. The results of these two objectives are reported in the form of two papers, each dealing with one of the objectives.

  6. Chemical analyses for selected wells in San Joaquin County and part of Contra Costa County, California

    USGS Publications Warehouse

    Keeter, Gail L.

    1980-01-01

    The study area of this report includes the eastern valley area of Contra Costa County and all of San Joaquin County, an area of approximately 1,600 square miles in the northern part of the San Joaquin Valley, Calif. Between December 1977 and December 1978, 1,489 wells were selectively canvassed. During May and June in 1978 and 1979, water samples were collected for chemical analysis from 321 of these wells. Field determinations of alkalinity, conductance, pH, and temperature were made, and individual constituents were analyzed. This report is the fourth in a series of baseline data reports on wells in the Sacramento and San Joaquin Valleys. (USGS)

  7. Neural pattern similarity between contra- and ipsilateral movements in high-frequency band of human electrocorticograms.

    PubMed

    Fujiwara, Yusuke; Matsumoto, Riki; Nakae, Takuro; Usami, Kiyohide; Matsuhashi, Masao; Kikuchi, Takayuki; Yoshida, Kazumichi; Kunieda, Takeharu; Miyamoto, Susumu; Mima, Tatsuya; Ikeda, Akio; Osu, Rieko

    2017-02-15

    The cortical motor areas are activated not only during contralateral limb movements but also during ipsilateral limb movements. Although these ipsilateral activities have been observed in several brain imaging studies, their functional role is poorly understood. Due to its high temporal resolution and low susceptibility to artifacts from body movements, the electrocorticogram (ECoG) is an advantageous measurement method for assessing the human brain function of motor behaviors. Here, we demonstrate that contra- and ipsilateral movements share a similarity in the high-frequency band of human ECoG signals. The ECoG signals were measured from the unilateral sensorimotor cortex while patients conducted self-paced movements of different body parts, contra- or ipsilateral to the measurement side. The movement categories (wrist, shoulder, or ankle) of ipsilateral movements were decoded as accurately as those of contralateral movements from spatial patterns of the high-frequency band of the precentral motor area (the primary motor and premotor areas). The decoder, trained in the high-frequency band of ipsilateral movements generalized to contralateral movements, and vice versa, confirmed that the activity patterns related to ipsilateral limb movements were similar to contralateral ones in the precentral motor area. Our results suggest that the high-frequency band activity patterns of ipsilateral and contralateral movements might be functionally coupled to control limbs, even during unilateral movements.

  8. Air-structure coupling features analysis of mining contra-rotating axial flow fan cascade

    NASA Astrophysics Data System (ADS)

    Chen, Q. G.; Sun, W.; Li, F.; Zhang, Y. J.

    2013-12-01

    The interaction between contra-rotating axial flow fan blade and working gas has been studied by means of establishing air-structure coupling control equation and combining Computational Fluid Dynamics (CFD) and Computational solid mechanics (CSM). Based on the single flow channel model, the Finite Volume Method was used to make the field discrete. Additionally, the SIMPLE algorithm, the Standard k-ε model and the Arbitrary Lagrangian-Eulerian dynamic grids technology were utilized to get the airflow motion by solving the discrete governing equations. At the same time, the Finite Element Method was used to make the field discrete to solve dynamic response characteristics of blade. Based on weak coupling method, data exchange from the fluid solver and the solid solver was processed on the coupling interface. Then interpolation was used to obtain the coupling characteristics. The results showed that the blade's maximum amplitude was on the tip of the last-stage blade and aerodynamic force signal could reflect the blade working conditions to some extent. By analyzing the flow regime in contra-rotating axial flow fan, it could be found that the vortex core region was mainly in the blade surface, the hub and the blade clearance. In those regions, the turbulence intensity was very high. The last-stage blade's operating life is shorter than that of the pre-stage blade due to the fatigue fracture occurs much more easily on the last-stage blade which bears more stress.

  9. A feasibility study on a new brushless and gearless contra-rotating permanent magnet wind power generator

    NASA Astrophysics Data System (ADS)

    Niu, Shuangxia; Ho, S. L.; Fu, W. N.; Chau, K. T.; Lin, F.

    2014-05-01

    In this paper, a novel fully integrated contra-rotating permanent magnet (PM) generator is proposed. In order to efficiently capture wind energy, two contra-rotating rotors are integrated, based on magnetic field modulating principle, into a single PM machine. A relatively high angular velocity is created and the torque density is improved. The steady-state and transient performance of the machine is simulated using time-stepping finite-element method. The computation results are used to showcase the validity of the proposed machine design.

  10. Tone and Broadband Noise Separation from Acoustic Data of a Scale-Model Contra-Rotating Open Rotor

    NASA Technical Reports Server (NTRS)

    Sree, Dave; Stephens, David B.

    2014-01-01

    Renewed interest in contra-rotating open rotor technology for aircraft propulsion application has prompted the development of advanced diagnostic tools for better design and improved acoustical performance. In particular, the determination of tonal and broadband components of open rotor acoustic spectra is essential for properly assessing the noise control parameters and also for validating the open rotor noise simulation codes. The technique of phase averaging has been employed to separate the tone and broadband components from a single rotor, but this method does not work for the two-shaft contra-rotating open rotor. A new signal processing technique was recently developed to process the contra-rotating open rotor acoustic data. The technique was first tested using acoustic data taken of a hobby aircraft open rotor propeller, and reported previously. The intent of the present work is to verify and validate the applicability of the new technique to a realistic one-fifth scale open rotor model which has 12 forward and 10 aft contra-rotating blades operating at realistic forward flight Mach numbers and tip speeds. The results and discussions of that study are presented in this paper.

  11. Map showing locations of damaging landslides in Contra Costa County, California, resulting from 1997-98 El Nino rainstorms

    USGS Publications Warehouse

    Graymer, Russell W.; Godt, Jonathan W.

    1999-01-01

    Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $27 million in damages were assessed in Contra Costa County.

  12. Thirty-Seven Years of the Contra Costa Community College District Governing Board's Minutes in Historical Context. An Abstract.

    ERIC Educational Resources Information Center

    Drexel, Karl O., Ed.; And Others

    This compilation of highly condensed abstracts of the minutes of governing board meetings chronicles the 37-year history of the Contra Costa Community College District (CCCCD) from 1949 to 1986. First, introductory material describes the context and the character of the opening years of the district, and lists the previous and current members of…

  13. Education in the Privately Owned Vocational Schools in Alameda and Contra Costa Counties. Report No. 1967-2.

    ERIC Educational Resources Information Center

    Enns, Abram; And Others

    The purpose of the study was to assess the number of privately owned vocational schools, the occupations for which the schools train, and the extent of their enrollment and labor market placement. This study is the fourth dimension of a descriptive study encompassing formal vocational-technical education offerings in Alameda and Contra Costa…

  14. The Contra-Diction of Design: Blake's Illustrations to Gray's "Ode on the Death of a Favourite Cat."

    ERIC Educational Resources Information Center

    Lussier, Mark

    1989-01-01

    Argues that William Blake's illustrations for Thomas Gray's "Ode on the Death of a Favourite Cat" testify to the contradictions in Gray's poetry. States that Blake's designs offer another language, a contra-diction, that deconstructs Gray's conscious discourse and liberates his unconscious discourse. (RS)

  15. Author's Response to Commentaries on: "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics"

    ERIC Educational Resources Information Center

    Molenaar, Peter C. M.

    2015-01-01

    In this article, Peter Molenaar responds to three commentaries (this issue) on his article, "An Interpretation of Part of Gilbert Gottlieb's Legacy: Developmental Systems Theory Contra Developmental Behavior Genetics." He addresses aspects of relational developmental systems (RDS) mentioned and questions raised in each of the…

  16. Mycoplasma viruses.

    PubMed

    Maniloff, J

    1988-01-01

    Unlike bacterial viruses that infect cells bounded by a cell wall, mycoplasma viruses have evolved to enter and propagate in mycoplasma cells bounded only by a single lipid-protein cell membrane. In addition, mycoplasmas have the smallest amount of genetic information of any known cells, so their complexity is constrained by a limited genetic coding capacity. As a consequence of these host cell differences, mycoplasma viruses have been found to have a variety of structures and replication strategies which are different from those of the bacterial viruses. This article is a critical review of mycoplasma viruses infecting the genera Acholeplasma, Spiroplasma, and Mycoplasma; included are data on classification, morphology and structure, biological and physical properties, chemical composition, and productive and lysogenic replication cycles.

  17. Numerical Simulation of Cavitation Phenomena for Hybrid Contra-Rotating Shaft Propellers

    NASA Astrophysics Data System (ADS)

    Kim, Sung-Hoon; Choo, Sung-Han; Park, Jeong-Yong; Choi, Gil-Hwan

    2015-12-01

    This paper deals with a numerical simulation of cavitation flow around a hybrid contra-rotating shaft propeller operating in wake field. The simulation for the cavitating flow is performed for straight operating and turning condition of podded propeller located behind the main propeller using unsteady Reynolds-Averaged Navier-Stokes. The behavior of the main propeller is almost similar regardless of the turning angle. In contrast, the cavitation behavior of the podded propeller depending on the turning angle appears to be entirely different due to the change of the load distribution on the podded propeller. At the large angle of the turning condition, the unstable cavity flow due to the large amount of cavitation and the hub vortex separated from the forward propeller as well as face cavitation is observed. Thus, a great caution on the cavitation phenomena is needed when designing and operating the HCRSP.

  18. Reduction of Unsteady Forcing in a Vaned, Contra-Rotating Transonic Turbine Configuration

    NASA Technical Reports Server (NTRS)

    Clark, John

    2010-01-01

    HPT blade unsteadiness in the presence of a downstream vane consistent with contra-rotation is characterized by strong interaction at the first harmonic of downstream vane passing. E An existing stage-and-one-half transonic turbine rig design was used as a baseline to investigate means of reducing such a blade-vane interaction. E Methods assessed included: Aerodynamic shaping of HPT blades 3D stacking of the downstream vane Steady pressure-side blowing E Of the methods assessed, a combination of vane bowing and steady pressure-side blowing produced the most favorable result. E Transonic turbine experiments are planned to assess predictive accuracy for the baseline turbine and any design improvements.

  19. The politics of presidential illness. Ronald Reagan and the Iran-Contra Scandal.

    PubMed

    Gilbert, Robert E

    2014-01-01

    This paper assesses the likelihood that the Iran-Contra scandal was shaped heavily by the effects of Ronald Reagan's cancer surgery in summer, 1985. During the President's hospitalization and in the period soon after, he took several actions--which he apparently did not remember--that launched a policy that was unwise, counterproductive, and a failure. These damaged both his Administration and his standing in history. The 25th Amendment afforded Reagan the means by which his involvement in these events could easily have been avoided. However, the President and his aides determined that he would resume the powers and duties of the presidency only hours after undergoing extensive cancer surgery. This decision contributed materially to the most damaging episode of Reagan's eight-year presidency.

  20. Intestinal parasites among Indochinese refugees and Mexican immigrants resettled in Contra Costa County, California.

    PubMed

    Arfaa, F

    1981-02-01

    Stool examinations of 186 Indochinese refugees and 90 immigrants from Mexico resettled in Contra Costa, County, California, have shown that 60 percent of refugees and 39 percent of immigrants are infected with one or more species of pathogenic protozoa and helminths. The mean prevalences of infections among refugees and immigrants, respectively, were: hookworms, 25 and 2 percent; whipworm, 22 and 12 percent; Ascaris, 20 and 12 percent; Giardia lamblia, 11 and 11 percent; Strongyloides, 9 and 1 percent; and Entamoeba histolytica, 2 and 4 percent. clonorchis sinensis was found in 13 percent of refugees and dwarf tapeworm in 9 percent of immigrants. Rates of infection varied with age and sex. Treatment of these parasitic infections is important and justified because: the prevalence is high; some species are highly pathogenic and directly transmittable; most species have long life spans; and safe broad-spectrum drugs are now available.

  1. [Illness due the Ebola virus: epidemiology and clinical manifestations within the context of an international public health emergency].

    PubMed

    Carod-Artal, Francisco J

    2015-03-16

    Introduccion. La epidemia causada por el virus del Ebola en Africa occidental afecta a Guinea, Liberia, Sierra Leona, Nigeria, Mali y Senegal, y es la mas grave desde que se tiene noticia de este filovirus causante de fiebre hemorragica. En este articulo se revisan las caracteristicas epidemiologicas y las manifestaciones clinicas asociadas a la enfermedad por el virus del Ebola. Desarrollo. Hasta el 23 de febrero de 2015 se habian contabilizado 23.729 casos de ebola, con un 40,1% de mortalidad. En la actual epidemia, el virus se transmite al ser humano por tres vias: contacto con fluidos y secreciones de sujetos enfermos ya diagnosticados, contacto con cadaveres durante las ceremonias de enterramiento, y contagio a familiares y personal sanitario por enfermos sin diagnosticar. El Ebola causa una enfermedad grave en humanos. Tras un periodo de incubacion variable (2-21 dias), se inicia un sindrome febril, cefalea, mialgias, artralgias, vomitos y diarrea. La fase avanzada cursa con hemorragias, fracaso de multiples organos, hipotension y choque. Se desconoce la incidencia de manifestaciones neurologicas, aunque se han descrito hemorragias cerebrales y sindromes postinfecciosos en otras fiebres he­morragicas virales. Los cuidados de soporte son vitales. No existe un tratamiento efectivo demostrado, aunque varios pacientes han sido tratados con un coctel de anticuerpos monoclonales (ZMapp). Conclusiones. La identificacion y diagnostico precoz de casos sospechosos, el aislamiento de sujetos enfermos y las medidas de proteccion en el personal sanitario son fundamentales para contener esta epidemia.

  2. Computer viruses

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    The worm, Trojan horse, bacterium, and virus are destructive programs that attack information stored in a computer's memory. Virus programs, which propagate by incorporating copies of themselves into other programs, are a growing menace in the late-1980s world of unprotected, networked workstations and personal computers. Limited immunity is offered by memory protection hardware, digitally authenticated object programs,and antibody programs that kill specific viruses. Additional immunity can be gained from the practice of digital hygiene, primarily the refusal to use software from untrusted sources. Full immunity requires attention in a social dimension, the accountability of programmers.

  3. Lassa virus.

    PubMed

    Günther, Stephan; Lenz, Oliver

    2004-01-01

    Lassa virus is a RNA virus belonging to the family of Arenaviridae. It was discovered as the causative agent of a hemorrhagic fever--Lassa fever--about 30 years ago. Lassa fever is endemic in West Africa and is estimated to affect some 100,000 people annually. Great progress in the understanding of the life cycle of arenaviruses, including Lassa virus, has been made in recent years. New insights have been gained in the pathogenesis and molecular epidemiology of Lassa fever, and state-of the-art technologies for diagnosing this life-threatening disease have been developed. The intention of this review is to summarize in particular the recent literature on Lassa virus and Lassa fever. Several aspects ranging from basic research up to clinical practice and laboratory diagnosis are discussed and linked together.

  4. Zika Virus

    MedlinePlus

    ... Search Form Controls Cancel Submit Search the CDC Zika Virus Note: Javascript is disabled or is not ... Recommend on Facebook Tweet Share Compartir Men and Zika Zika Cases in Texas What’s your Zika IQ? ...

  5. Virophages or satellite viruses?

    PubMed

    Krupovic, Mart; Cvirkaite-Krupovic, Virginija

    2011-11-01

    It has been argued that the smaller viruses associated with giant DNA viruses are a new biological entity. However, Mart Krupovic and Virginija Cvirkaite-Krupovic argue here that these smaller viruses should be classified with the satellite viruses.

  6. Ebola Virus and Marburg Virus

    MedlinePlus

    ... chimps and fruit bats in Africa. Transmission from animals to humans Experts suspect that both viruses are transmitted to humans through an infected animal's bodily fluids. Examples include: Blood. Butchering or eating ...

  7. Design and Testing of the Contra-Rotating Turbine for the Scimitar Precooled Mach 5 Cruise Engine

    NASA Astrophysics Data System (ADS)

    Varvill, R.; Paniagua, G.; Kato, H.; Thatcher, M.

    tion chamber and subsequent expansion through the main noz- zle to produce thrust. In subsonic flight it becomes the gas generator driving a high bypass ratio ducted fan through a hub turbine, the exhaust mixing with the duct flow and discharging through the bypass nozzle to produce thrust. In both modes the turbo-compressor is driven by a helium turbine which has contra rotating stages to improve its efficiency at low rotational speed and reduce the number of stages required. Due to the large speed of sound mismatch between the air compressor and the helium turbine it is possible to eliminate the turbine stators by contra rotating the spools. The compressor is divided into low pressure and high pressure spools although by normal gas turbine standards they are both low pressure ratio machines.

  8. Numerical analysis of head degrade law under cavitation condition of contra-rotating axial flow waterjet pump

    NASA Astrophysics Data System (ADS)

    Huang, D.; Pan, Z. Y.

    2015-01-01

    In order to study the flow-head characteristic curve, the SST turbulence model, homogeneous multiphase model and Rayleigh-Plesset equation were applied to simulate the cavitation characteristics in contra-rotating axial flow waterjet pump under different conditions based on ANSYS CFX software. The distribution of cavity, pressure coefficient of the blade at the design point under different cavitation conditions were obtained. The analysis results of flow field show that the vapour volume distribution on the impeller indicates that the vapour first appears at the leading edge of blade and then extends to the outlet of impeller with the reduction of Net Positive Suction Head Allowance (NPSHA). The present study illustrates that the main reason for the decline of the pump performance is the development of cavitation, and the simulation can truly reflect the cavitation performance of the contra-rotating axial flow waterjet pump.

  9. CONTRA: Improving the performance of dynamic investigations in natural abundance organic solids by mirror-symmetric constant-time CODEX

    NASA Astrophysics Data System (ADS)

    Reichert, Detlef; Pascui, Ovidiu; Bonagamba, Tito J.; Belton, Peter; Schmidt, Asher; deAzevedo, Eduardo Ribeiro

    2008-03-01

    We present a minor but essential modification to the CODEX 1D-MAS exchange experiment. The new CONTRA method, which requires minor changes of the original sequence only, has advantages over the previously introduced S-CODEX, since it is less sensitive to artefacts caused by finite pulse lengths. The performance of this variant, including the finite pulse effect, was confirmed by SIMPSON calculations and demonstrated on a number of dynamic systems.

  10. CONTRA: improving the performance of dynamic investigations in natural abundance organic solids by mirror-symmetric constant-time CODEX.

    PubMed

    Reichert, Detlef; Pascui, Ovidiu; Bonagamba, Tito J; Belton, Peter; Schmidt, Asher; deAzevedo, Eduardo Ribeiro

    2008-03-01

    We present a minor but essential modification to the CODEX 1D-MAS exchange experiment. The new CONTRA method, which requires minor changes of the original sequence only, has advantages over the previously introduced S-CODEX, since it is less sensitive to artefacts caused by finite pulse lengths. The performance of this variant, including the finite pulse effect, was confirmed by SIMPSON calculations and demonstrated on a number of dynamic systems.

  11. Computer Viruses. Technology Update.

    ERIC Educational Resources Information Center

    Ponder, Tim, Comp.; Ropog, Marty, Comp.; Keating, Joseph, Comp.

    This document provides general information on computer viruses, how to help protect a computer network from them, measures to take if a computer becomes infected. Highlights include the origins of computer viruses; virus contraction; a description of some common virus types (File Virus, Boot Sector/Partition Table Viruses, Trojan Horses, and…

  12. Foodborne viruses.

    PubMed

    Koopmans, Marion; von Bonsdorff, Carl Henrik; Vinjé, Jan; de Medici, Dario; Monroe, Steve

    2002-06-01

    Foodborne and waterborne viral infections are increasingly recognized as causes of illness in humans. This increase is partly explained by changes in food processing and consumption patterns that lead to the worldwide availability of high-risk food. As a result, vast outbreaks may occur due to contamination of food by a single foodhandler or at a single source. Although there are numerous fecal-orally transmitted viruses, most reports of foodborne transmission describe infections with Norwalk-like caliciviruses (NLV) and hepatitis A virus (HAV), suggesting that these viruses are associated with the greatest risk of foodborne transmission. NLV and HAV can be transmitted from person to person, or indirectly via food, water, or fomites contaminated with virus-containing feces or vomit. People can be infected without showing symptoms. The high frequency of secondary cases of NLV illness and - to a lesser extent - of hepatitis A following a foodborne outbreak results in amplification of the problem. The burden of illness is highest in the elderly, and therefore is likely to increase due to the aging population. For HAV, the burden of illness may increase following hygienic control measures, due to a decreasing population of naturally immune individuals and a concurrent increase in the population at risk. Recent advances in the research of NLV and HAV have led to the development of molecular methods which can be used for molecular tracing of virus strains. These methods can be and have been used for the detection of common source outbreaks. While traditionally certain foods have been implicated in virus outbreaks, it is clear that almost any food item can be involved, provided it has been handled by an infected person. There are no established methods for detection of viruses in foods other than shellfish. Little information is available on disinfection and preventive measures specifically for these viruses. Studies addressing this issue are hampered by the lack of

  13. Peak velocity of elbow joint during touching contra lateral shoulder activity for normal subject

    NASA Astrophysics Data System (ADS)

    Nan, Hasyatun Che; Rambely, Azmin Sham

    2017-04-01

    A better understanding of upper limb movements requires analysis of motion. Measurements of movement analysis through biomechanical studies are necessary to describe upper limb activities. Therefore this study intend to investigate peak velocity of elbow joint for different age groups during the "touching contra lateral shoulder" activity. Twenty healthy subjects age range 20 - 59 years old (n = 60) performed a complete cycle of hand lifting, resting and returning the hand to its initial position. This activity was analyzed using Vicon motion-analysis system, which consists of three infra-red and high speed cameras. Phase definitions were defined and descriptive kinematic variables were obtained from this activity. Movement times is found to increase in 50's age group. The difference of movement times is < 0.3s. Peak velocity for subject age 50s' also higher between all subjects. The difference of peak velocity is < 0.03m/s for all different phases. It was found that there were a significant difference in total movement time and no significance different between each age group for peak velocity parameter.

  14. Contra-thermodynamic behavior in intermolecular hydrogen transfer of alkylperoxy radicals.

    PubMed

    Pfaendtner, Jim; Broadbelt, Linda J

    2007-09-17

    Quantum chemical investigation of bimolecular hydrogen transfer involving alkylperoxy radicals, a key reaction family in the free-radical oxidation of hydrocarbons, was performed to establish structure-reactivity relationships. Eight different reactions were investigated featuring four different alkane substrates (methane, ethane, propane and isobutane) and two different alkylperoxy radicals (methylperoxy and iso-propylperoxy). Including forward and reverse pairs, sixteen different activation energies and enthalpies of reaction were used to formulate structure-reactivity relationships to describe this chemistry. We observed that the enthalpy of formation of loosely bound intermediate states has a strong inverse correlation with the overall heat of reaction and that this results in unique contra-thermodynamic behavior such that more exothermic reactions have higher activation barriers. A new structure-reactivity relationship was proposed that fits the calculated data extremely well: E(A)=E(o)+alphaDeltaH(rxn) where alpha=-0.10 for DeltaH(rxn)<0, and alpha=1.10 for DeltaH(rxn)>0 and E(o)=3.05 kcal mol(-1).

  15. Monitoring for PAH and criteria pollutants in Contra Costa County, CA, 1979-1986

    SciTech Connect

    Flessel, P. ); Levaggi, D.A. )

    1987-01-01

    Concentrations of three polycyclic aromatic hydrocarbons (PAH) were monitored in ambient air at three locations in Contra Costa County from November 1979 through October 1986. Benzo(a)pyrene(BaP), benzo(k)fluoranthene(BkF) and benzo(ghi)perylene(BghiP) concentrations as wells as criteria pollutants were measured concurrently at the same locations. This report describes seasonal variations and seven-year trends. PAH and most criteria pollutant concentrations were highest in the winter, when ventilation in the Bay Area is the lowest. Statistically significant downward trend in annual average concentrations of lead (Pb), sulfates (SO{sub 4}{sup -}), total suspended particulates (TSP) and ozone (O{sub 3}) were observed. The decrease in lead was especially dramatic and widespread, averaging about 20% per year and occurring in every season and at every station. In contrast, CO concentrations increased at an annual rate of about 6%; mobile sources probably were responsible for the increase in CO. In general, PAH concentrations did not change greatly. However, increases in benzo(a)pyrene were seen.

  16. Survey of canine and feline populations: Alameda and Contra Costa Counties, California, 1970.

    PubMed

    Schneider, R; Vaida, M L

    1975-03-01

    Age, sex, breed, and reproductive data were obtained on canine and feline populations in Alameda and Contra Costa counties, California. The demographic data were determined as of Dec 31, 1970, the reproductive data for all of 1970. The total of 27,076 households interviewed represented 5% of all households in the area. The canine and feline populations were estimated as 224,815 and 151,176, respectively. There was 1 dog for 7.3 persons and 1 cat for 10.8 persons. Almost half of the households included at least 1 dog or 1 cat. From the proportional distribution by age, it appeared that growth in the canine population may have peaked in 1968, with subsequent declines in pups entering households in 1969 and 1970. It was found that 47.8% of bitches and 64.6% of queens were neutered. Intact bitches of all ages averaged 0.2 litters each, those of queens, 0.9 litters each. The highest reproducing ages for both bitches and queens was between 1 and 3 years of age. In that age range, 62.9% of all canine litters and 74.4% of all feline litters were born; there were 0.4 litters per intact bitch and 1.6 litters per intact queen.

  17. Analyzing equity impacts of transit fare changes: Case study of Alameda-Contra Costa Transit, California.

    PubMed

    Nuworsoo, Cornelius; Golub, Aaron; Deakin, Elizabeth

    2009-11-01

    Many public transit agencies consider increasing fares when faced with budget shortfalls. This paper analyzes the Alameda-Contra Costa (AC) Transit District's five alternative fare proposals introduced for public discussion in March 2005. The proposals combined fare hikes, base fare reductions, eliminations of free transfers, and discontinuation of periodic passes. Using the agency's 2002 on-board survey data, the study assessed the impacts of individual fare proposals on different subsets of riders and evaluated if they were equitable; and estimated potential fare revenues, using alternative price elasticities to estimate changes in ridership due to changes in price. The analysis revealed that proposals that increased the cost of transfers or eliminated unlimited-use passes produced dramatically unequal impacts on certain riders. Proposals for flat fares per ride were found to be least equitable, even when the base fare was lowered, because lower income riders, youth, and minorities made more trips and transferred more frequently than their more affluent counterparts. Proposals that maintained existing pass instruments and allowed transfers for small fees were the most favorable. The paper demonstrates the utility of on-board surveys and details an approach that could be widely used for evaluation of equity in public transit and other areas.

  18. Nanofiltration Membranes with Narrow Pore Size Distribution via Contra-Diffusion-Induced Mussel-Inspired Chemistry.

    PubMed

    Du, Yong; Qiu, Wen-Ze; Lv, Yan; Wu, Jian; Xu, Zhi-Kang

    2016-11-02

    Nanofiltration membranes (NFMs) are widely used in saline water desalination, wastewater treatment, and chemical product purification. However, conventional NFMs suffer from broad pore size distribution, which limits their applications for fine separation, especially in complete separation of molecules with slight differences in molecular size. Herein, defect-free composite NFMs with narrow pore size distribution are fabricated using a contra-diffusion method, with dopamine/polyethylenimine solution on the skin side and ammonium persulfate solution on the other side of the ultrafiltration substrate. Persulfate ions can diffuse through the ultrafiltration substrate into the other side and in situ trigger dopamine to form a codeposited coating with polyethylenimine. The codeposition is hindered on those sites completely covered by the polydopamine/polyethylenimine coating, although it is promoted at the defects or highly permeable regions because it is induced by the diffused persulfate ions. Such a "self-completion" process results in NFMs with highly uniform structures and narrow pore size distribution, as determined by their rejection of neutral solutes. These near electrically neutral NFMs show a high rejection of divalent ions with a low rejection of monovalent ions (MgCl2 rejection = 96%, NaCl rejection = 23%), majorly based on a steric hindrance effect. The as-prepared NFMs can be applied in molecular separation such as isolating cellulose hydrogenation products.

  19. Structured Overlapping Grid Simulations of Contra-rotating Open Rotor Noise

    NASA Technical Reports Server (NTRS)

    Housman, Jeffrey A.; Kiris, Cetin C.

    2015-01-01

    Computational simulations using structured overlapping grids with the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework are presented for predicting tonal noise generated by a contra-rotating open rotor (CROR) propulsion system. A coupled Computational Fluid Dynamics (CFD) and Computational AeroAcoustics (CAA) numerical approach is applied. Three-dimensional time-accurate hybrid Reynolds Averaged Navier-Stokes/Large Eddy Simulation (RANS/LES) CFD simulations are performed in the inertial frame, including dynamic moving grids, using a higher-order accurate finite difference discretization on structured overlapping grids. A higher-order accurate free-stream preserving metric discretization with discrete enforcement of the Geometric Conservation Law (GCL) on moving curvilinear grids is used to create an accurate, efficient, and stable numerical scheme. The aeroacoustic analysis is based on a permeable surface Ffowcs Williams-Hawkings (FW-H) approach, evaluated in the frequency domain. A time-step sensitivity study was performed using only the forward row of blades to determine an adequate time-step. The numerical approach is validated against existing wind tunnel measurements.

  20. Zika Virus.

    PubMed

    FitzSimmons, Jack; Shah, Shailen

    2016-06-29

    To the Editor: Petersen et al. (April 21 issue)(1) provide a detailed review of Zika virus. We have some concern regarding diagnostic criteria for microcephaly in fetuses and newborns exposed to the virus. According to the Centers for Disease Control and Prevention (CDC) recommendation that microcephaly should be defined as an occipitofrontal circumference below the third percentile, nearly 3% of newborns would be categorized as having microcephaly. In Brazil, where there are 3 million live births per year, the application of this definition would result in nearly 90,000 infants being labeled as having microcephaly - a far greater number than . . .

  1. Semi-automated CT-based analysis of regional bone-density in contra lateral total hip replacement

    NASA Astrophysics Data System (ADS)

    Barbu-McInnis, Monica; Tamez-Pena, Jose; Crilly, Therese; Looney, John R.; O'Keefe, R.; Campbell, Debbie; Totterman, Saara M.

    2004-04-01

    Methods for quantifying hip prosthesis induced changes in the adjacent bone are of great interest to orthopedics. In this work, we present a semi-automated technique for measuring the differences in bone density between the prosthetic and contra lateral hips within a CT volumetric data set. In order to reliably compare the bone-density measurements between the prosthetic and the contra laterals hips, a standardized zoning was developed. Using a spherical model of the outer surface of the prosthetic cup, the superior volume of the acetabular region was subdivided into four distance zones: 0-1mm, 1-6mm, 6-11mm, and 11-16mm, respectively. Furthermore, these regions were divided into four positional zones: medial, lateral, anterior, and posterior. At the same time, the positional zones were divided into four angular regions 15, 30, 45, and 60 degrees from the apex of the acetabular cup. The bone density is computed as the average density in Hounsfield unit (HU) measured from the CT scan using all the voxels within each of the 64 zones. Preliminary analysis has been completed on 3 subjects with total hip replacement. The zonal densities on the prosthetic hip and the contra lateral hip were computed and compared. Contrary to initial expectations, a paired t-test showed no statistical significance between the prosthetic and contra lateral bone-densities at any of the four distance zones. Further analysis with a larger sample subject is needed to detect differences in bone-density between the hips in the stress/weight bearing areas in the 15 to 30 degree regions. A method for reliably and consistently measuring the bone-density within standardized zones has been developed and applied on prosthetic and contra lateral hips. The average bone-density for each of the zones takes into account the entire volumetric data set within that region, which is a considerable improvement over the subjective, user driven region of interest estimate selected within one slice practiced in

  2. [Influenza virus].

    PubMed

    Juozapaitis, Mindaugas; Antoniukas, Linas

    2007-01-01

    Every year, especially during the cold season, many people catch an acute respiratory disease, namely flu. It is easy to catch this disease; therefore, it spreads very rapidly and often becomes an epidemic or a global pandemic. Airway inflammation and other body ailments, which form in a very short period, torment the patient several weeks. After that, the symptoms of the disease usually disappear as quickly as they emerged. The great epidemics of flu have rather unique characteristics; therefore, it is possible to identify descriptions of such epidemics in historic sources. Already in the 4th century bc, Hippocrates himself wrote about one of them. It is known now that flu epidemics emerge rather frequently, but there are no regular intervals between those events. The epidemics can differ in their consequences, but usually they cause an increased mortality of elderly people. The great flu epidemics of the last century took millions of human lives. In 1918-19, during "The Spanish" pandemic of flu, there were around 40-50 millions of deaths all over the world; "Pandemic of Asia" in 1957 took up to one million lives, etc. Influenza virus can cause various disorders of the respiratory system: from mild inflammations of upper airways to acute pneumonia that finally results in the patient's death. Scientist Richard E. Shope, who investigated swine flu in 1920, had a suspicion that the cause of this disease might be a virus. Already in 1933, scientists from the National Institute for Medical Research in London - Wilson Smith, Sir Christopher Andrewes, and Sir Patrick Laidlaw - for the first time isolated the virus, which caused human flu. Then scientific community started the exhaustive research of influenza virus, and the great interest in this virus and its unique features is still active even today.

  3. [Influence of manufacturing procedure on stability of Unguentum contra perniones preparations].

    PubMed

    Bosković, Mirjana; Toskić-Radojicić, Marija

    2005-04-01

    Application of various technological procedures for the manufacture of officinal preparation ointment against chilblains (Unguentum contra perniones) produce essential variations in the quality and stability of the final product. Changing the sequence of admixing active substances into the ointment base indicated the presence of incompatibility between the active substances, as well as between the active substances and the ointment base components. The aim was to examine the influence of various technological manufacturing procedures on quality and stability of the preparation. Changes in the samples of ointments and aqueous solutions of active substances were analysed microscopically. Microscopic analysis of hydrosoluble active substance solutions demonstrated destruction of ichthammol, induced by an acidic medium due to the dissolution of tannin and resorcinol, which is well known from the literature. It also demonstrated the destruction of tannin and resorcinol in aqueous solution, which had not been described in the literature. Application of the prescribed procedure for the manufacturing of ointment against chilblains, conceals the incompatibility reactions due to a slow dissolution of the tannin suspended in the officinal ointment base Unguentum cera lanae. Admixture of an ready-made aqueous solution of tannin caused an instant contact between ichthammol and the acidic medium, which caused the destruction or the complete absence of the formation of emulsion droplets. The problem of incompatibility reactions between lanolin alcohols in the ointment base and ichthammol and resorcinol, as well as the reaction between Peruvian balsam and sulfur from the ichthammol sulfate ion was observed. Numerous incompatibility reactions of ointment against chilblains, components indicated that it was necessary to introduce alterations in both the qualitative and quantitative composition of the preparation. Excipient preparation procedure, as well as the technological

  4. Honeybee viruses in Uruguay.

    PubMed

    Antúnez, Karina; D'Alessandro, Bruno; Corbella, Eduardo; Ramallo, Gustavo; Zunino, Pablo

    2006-09-01

    Mortality of honeybees is a serious problem that beekeepers have to face periodically in Uruguay and worldwide. The presence of RNA viruses, in addition to other pathogens may be one of its possible causes. In this work, we detected Chronic bee paralysis virus, Acute bee paralysis virus, Black queen cell virus, Sacbrood virus and Deformed wing virus in samples of Uruguayan honeybees with or without Varroa destructor and Nosema apis. The detection of viruses in different provinces, simultaneous co-infection of colonies by several viruses and the fact that 96% of the samples were infected with one or more virus, indicates they are widely spread in the region.

  5. The Geometry of Viruses.

    ERIC Educational Resources Information Center

    Case, Christine L.

    1991-01-01

    Presented is an activity in which students make models of viruses, which allows them to visualize the shape of these microorganisms. Included are some background on viruses, the biology and geometry of viruses, directions for building viruses, a comparison of cells and viruses, and questions for students. (KR)

  6. The Geometry of Viruses.

    ERIC Educational Resources Information Center

    Case, Christine L.

    1991-01-01

    Presented is an activity in which students make models of viruses, which allows them to visualize the shape of these microorganisms. Included are some background on viruses, the biology and geometry of viruses, directions for building viruses, a comparison of cells and viruses, and questions for students. (KR)

  7. Measles virus.

    PubMed

    Naim, Hussein Y

    2015-01-01

    Measles was an inevitable infection during the human development with substantial degree of morbidity and mortality. The severity of measles virus (MV) infection was largely contained by the development of a live attenuated vaccine that was introduced into the vaccination programs. However, all efforts to eradicate the disease failed and continued to annually result in significant deaths. The development of molecular biology techniques allowed the rescue of MV from cDNA that enabled important insights into a variety of aspects of the biology of the virus and its pathogenesis. Subsequently these technologies facilitated the development of novel vaccine candidates that induce immunity against measles and other pathogens. Based on the promising prospective, the use of MV as a recombinant vaccine and a therapeutic vector is addressed.

  8. Plant Virus Metagenomics: Advances in Virus Discovery.

    PubMed

    Roossinck, Marilyn J; Martin, Darren P; Roumagnac, Philippe

    2015-06-01

    In recent years plant viruses have been detected from many environments, including domestic and wild plants and interfaces between these systems-aquatic sources, feces of various animals, and insects. A variety of methods have been employed to study plant virus biodiversity, including enrichment for virus-like particles or virus-specific RNA or DNA, or the extraction of total nucleic acids, followed by next-generation deep sequencing and bioinformatic analyses. All of the methods have some shortcomings, but taken together these studies reveal our surprising lack of knowledge about plant viruses and point to the need for more comprehensive studies. In addition, many new viruses have been discovered, with most virus infections in wild plants appearing asymptomatic, suggesting that virus disease may be a byproduct of domestication. For plant pathologists these studies are providing useful tools to detect viruses, and perhaps to predict future problems that could threaten cultivated plants.

  9. Zika Virus.

    PubMed

    Musso, Didier; Gubler, Duane J

    2016-07-01

    Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) in the genus Flavivirus and the family Flaviviridae. ZIKV was first isolated from a nonhuman primate in 1947 and from mosquitoes in 1948 in Africa, and ZIKV infections in humans were sporadic for half a century before emerging in the Pacific and the Americas. ZIKV is usually transmitted by the bite of infected mosquitoes. The clinical presentation of Zika fever is nonspecific and can be misdiagnosed as other infectious diseases, especially those due to arboviruses such as dengue and chikungunya. ZIKV infection was associated with only mild illness prior to the large French Polynesian outbreak in 2013 and 2014, when severe neurological complications were reported, and the emergence in Brazil of a dramatic increase in severe congenital malformations (microcephaly) suspected to be associated with ZIKV. Laboratory diagnosis of Zika fever relies on virus isolation or detection of ZIKV-specific RNA. Serological diagnosis is complicated by cross-reactivity among members of the Flavivirus genus. The adaptation of ZIKV to an urban cycle involving humans and domestic mosquito vectors in tropical areas where dengue is endemic suggests that the incidence of ZIKV infections may be underestimated. There is a high potential for ZIKV emergence in urban centers in the tropics that are infested with competent mosquito vectors such as Aedes aegypti and Aedes albopictus. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  10. Zika Virus

    PubMed Central

    2016-01-01

    SUMMARY Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) in the genus Flavivirus and the family Flaviviridae. ZIKV was first isolated from a nonhuman primate in 1947 and from mosquitoes in 1948 in Africa, and ZIKV infections in humans were sporadic for half a century before emerging in the Pacific and the Americas. ZIKV is usually transmitted by the bite of infected mosquitoes. The clinical presentation of Zika fever is nonspecific and can be misdiagnosed as other infectious diseases, especially those due to arboviruses such as dengue and chikungunya. ZIKV infection was associated with only mild illness prior to the large French Polynesian outbreak in 2013 and 2014, when severe neurological complications were reported, and the emergence in Brazil of a dramatic increase in severe congenital malformations (microcephaly) suspected to be associated with ZIKV. Laboratory diagnosis of Zika fever relies on virus isolation or detection of ZIKV-specific RNA. Serological diagnosis is complicated by cross-reactivity among members of the Flavivirus genus. The adaptation of ZIKV to an urban cycle involving humans and domestic mosquito vectors in tropical areas where dengue is endemic suggests that the incidence of ZIKV infections may be underestimated. There is a high potential for ZIKV emergence in urban centers in the tropics that are infested with competent mosquito vectors such as Aedes aegypti and Aedes albopictus. PMID:27029595

  11. An epidemiologic study of unreported cutaneous malignant melanoma among residents of Alameda and Contra Costa Counties. Final report

    SciTech Connect

    West, D.W.; Whittemore, A.S. |; Zippin, C.; Lum, D.; Holly, E.

    1991-11-12

    Because of a reported excess of cutaneous malignant melanoma cases at the Lawrence Livermore National Laboratory during the 1970`s this study was funded to: determine if the number of cases in Alameda and Contra Costa Counties may have been underreported during 1973--1985 (this is the comparison group used to report an excess of melanoma at the LLNL), and determine if melanoma cases at the LLNL had different melanomas from the comparison population in terms of tumor thickness and therefore aggressiveness of tumors. The results of these two objectives are reported in the form of two papers, each dealing with one of the objectives.

  12. Ebola Virus Disease

    MedlinePlus

    ... sheets Fact files Questions & answers Features Multimedia Contacts Ebola virus disease Fact sheet Updated January 2016 Key ... for survivors of Ebola virus disease Symptoms of Ebola virus disease The incubation period, that is, the ...

  13. Influenza (Flu) Viruses

    MedlinePlus

    ... Seasonal Avian Swine/Variant Pandemic Other Influenza (Flu) Viruses Language: English (US) Español Recommend on Facebook ... circulate and cause illness. More Information about Flu Viruses Types of Influenza Viruses Influenza A and B ...

  14. Respiratory Syncytial Virus (RSV)

    MedlinePlus

    ... and premature birth: Are you at risk? Zika virus and pregnancy Folic acid Medicine safety and pregnancy ... It's been added to your dashboard . Respiratory syncytial virus (RSV) is a common virus that infects the ...

  15. Computer Viruses: An Overview.

    ERIC Educational Resources Information Center

    Marmion, Dan

    1990-01-01

    Discusses the early history and current proliferation of computer viruses that occur on Macintosh and DOS personal computers, mentions virus detection programs, and offers suggestions for how libraries can protect themselves and their users from damage by computer viruses. (LRW)

  16. SAMPLING VIRUSES FROM SOIL

    EPA Science Inventory

    This chapter describes in detail methods for detecting viruses of bacteria and humans in soil. Methods also are presented for the assay of these viruses. Reference sources are provided for information on viruses of plants.

  17. Zika Virus and Pregnancy

    MedlinePlus

    ... Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus ... Patient Education Pamphlets - Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your ...

  18. Computer Viruses: An Overview.

    ERIC Educational Resources Information Center

    Marmion, Dan

    1990-01-01

    Discusses the early history and current proliferation of computer viruses that occur on Macintosh and DOS personal computers, mentions virus detection programs, and offers suggestions for how libraries can protect themselves and their users from damage by computer viruses. (LRW)

  19. Hanta virus (image)

    MedlinePlus

    Hanta virus is a distant cousin of Ebola virus, but is found worldwide. The virus is spread by human contact with rodent waste. Dangerous respiratory illness develops. Effective treatment is not yet ...

  20. Virus Movement Maintains Local Virus Population Diversity

    SciTech Connect

    J. Snyder; B. Wiedenheft; M. Lavin; F. Roberto; J. Spuhler; A. Ortmann; T. Douglas; M. Young

    2007-11-01

    Viruses are the largest reservoir of genetic material on the planet, yet little is known about the population dynamics of any virus within its natural environment. Over a 2-year period, we monitored the diversity of two archaeal viruses found in hot springs within Yellowstone National Park (YNP). Both temporal phylogeny and neutral biodiversity models reveal that virus diversity in these local environments is not being maintained by mutation but rather by high rates of immigration from a globally distributed metacommunity. These results indicate that geographically isolated hot springs are readily able to exchange viruses. The importance of virus movement is supported by the detection of virus particles in air samples collected over YNP hot springs and by their detection in metacommunity sequencing projects conducted in the Sargasso Sea. Rapid rates of virus movement are not expected to be unique to these archaeal viruses but rather a common feature among virus metacommunities. The finding that virus immigration rather than mutation can dominate community structure has significant implications for understanding virus circulation and the role that viruses play in ecology and evolution by providing a reservoir of mobile genetic material.

  1. Virus movement maintains local virus population diversity.

    PubMed

    Snyder, Jamie C; Wiedenheft, Blake; Lavin, Matthew; Roberto, Francisco F; Spuhler, Josh; Ortmann, Alice C; Douglas, Trevor; Young, Mark

    2007-11-27

    Viruses are the largest reservoir of genetic material on the planet, yet little is known about the population dynamics of any virus within its natural environment. Over a 2-year period, we monitored the diversity of two archaeal viruses found in hot springs within Yellowstone National Park (YNP). Both temporal phylogeny and neutral biodiversity models reveal that virus diversity in these local environments is not being maintained by mutation but rather by high rates of immigration from a globally distributed metacommunity. These results indicate that geographically isolated hot springs are readily able to exchange viruses. The importance of virus movement is supported by the detection of virus particles in air samples collected over YNP hot springs and by their detection in metacommunity sequencing projects conducted in the Sargasso Sea. Rapid rates of virus movement are not expected to be unique to these archaeal viruses but rather a common feature among virus metacommunities. The finding that virus immigration rather than mutation can dominate community structure has significant implications for understanding virus circulation and the role that viruses play in ecology and evolution by providing a reservoir of mobile genetic material.

  2. Understanding viruses: Philosophical investigations.

    PubMed

    Pradeu, Thomas; Kostyrka, Gladys; Dupré, John

    2016-10-01

    Viruses have been virtually absent from philosophy of biology. In this editorial introduction, we explain why we think viruses are philosophically important. We focus on six issues (the definition of viruses, the individuality and diachronic identity of a virus, the possibility to classify viruses into species, the question of whether viruses are living, the question of whether viruses are organisms, and finally the biological roles of viruses in ecology and evolution), and we show how they relate to classic questions of philosophy of biology and even general philosophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Crystallization of viruses and virus proteins

    NASA Astrophysics Data System (ADS)

    Sehnke, Paul C.; Harrington, Melissa; Hosur, M. V.; Li, Yunge; Usha, R.; Craig Tucker, R.; Bomu, Wu; Stauffacher, Cynthia V.; Johnson, John E.

    1988-07-01

    Methods for crystallizing six isometric plant and insect viruses are presented. Procedures developed for modifying, purifying and crystallizing coat protein subunits isolated from a virus forming asymmetric, spheroidal particles, stabilized almost exclusively by protein-RNA interactions, are also discussed. The tertiary and quaternary structures of small RNA viruses are compared.

  4. Viruses and Virus Diseases of Rubus

    USDA-ARS?s Scientific Manuscript database

    Rubus species are propagated vegetatively and are subject to infection by viruses during development, propagation and fruit production stages. Reports of initial detection and symptoms of more than 30 viruses, virus-like diseases and phytoplasmas affecting Rubus spp. have been reviewed more than 20 ...

  5. The Tobacco Mosaic Virus.

    ERIC Educational Resources Information Center

    Sulzinski, Michael A.

    1992-01-01

    Explains how the tobacco mosaic virus can be used to study virology. Presents facts about the virus, procedures to handle the virus in the laboratory, and four laboratory exercises involving the viruses' survival under inactivating conditions, dilution end point, filterability, and microscopy. (MDH)

  6. The Tobacco Mosaic Virus.

    ERIC Educational Resources Information Center

    Sulzinski, Michael A.

    1992-01-01

    Explains how the tobacco mosaic virus can be used to study virology. Presents facts about the virus, procedures to handle the virus in the laboratory, and four laboratory exercises involving the viruses' survival under inactivating conditions, dilution end point, filterability, and microscopy. (MDH)

  7. Understanding Ebola Virus Transmission

    PubMed Central

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-01-01

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus. PMID:25654239

  8. Understanding ebola virus transmission.

    PubMed

    Judson, Seth; Prescott, Joseph; Munster, Vincent

    2015-02-03

    An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  9. THE EFFECTIVENESS OF THE CONTRA COSTA COLLEGE ELECTRONICS PROGRAM IN PREPARING ITS GRADUATES FOR EMPLOYMENT AS REPORTED BY POST-GRADUATE STUDENTS.

    ERIC Educational Resources Information Center

    STEPHENSON, DON

    IN 1967, GRADUATES OF THE ELECTRONICS PROGRAM OF CONTRA COSTA COLLEGE WERE SENT A QUESTIONNAIRE ASKING HOW THEY RATED THE CURRICULUM AND WHAT THEY DID AFTER GRADUATION. THE 178 STUDENTS POLLED HAD GRADUATED AT ANY TIME DURING THE 14-YEAR LIFE OF THE PROGRAM. SEVENTY-EIGHT USABLE RESPONSES WERE RECEIVED, FROM WHICH THE FOLLOWING DATA WERE…

  10. Virus-Vectored Influenza Virus Vaccines

    PubMed Central

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

    Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

  11. Assessment of Geometry and In-Flow Effects on Contra-Rotating Open Rotor Broadband Noise Predictions

    NASA Technical Reports Server (NTRS)

    Zawodny, Nikolas S.; Nark, Douglas M.; Boyd, D. Douglas, Jr.

    2015-01-01

    Application of previously formulated semi-analytical models for the prediction of broadband noise due to turbulent rotor wake interactions and rotor blade trailing edges is performed on the historical baseline F31/A31 contra-rotating open rotor configuration. Simplified two-dimensional blade element analysis is performed on cambered NACA 4-digit airfoil profiles, which are meant to serve as substitutes for the actual rotor blade sectional geometries. Rotor in-flow effects such as induced axial and tangential velocities are incorporated into the noise prediction models based on supporting computational fluid dynamics (CFD) results and simplified in-flow velocity models. Emphasis is placed on the development of simplified rotor in-flow models for the purpose of performing accurate noise predictions independent of CFD information. The broadband predictions are found to compare favorably with experimental acoustic results.

  12. Highlights from the first ecancer–Liga Colombiana contra el Cancer conference, 17–18 November 2016, Bogota, Colombia

    PubMed Central

    Castro, Carlos

    2017-01-01

    The first oncology conference organised by ecancer and the Liga Colombiana contra el Cancer took place on 17–18 November 2016 in Bogota. It was a highly successful event owing to the number of participants, the quality of the speakers, and the academic programme. Around 48 professors from 8 different countries came and shared their knowledge and experience of cancer management. They also talked about the most recent developments noted or achieved in this area. The keynote speech from Dr Nubia Muñoz was of great interest which was related to the safety of a HPV vaccine and the implications of a mass vaccination programme in developing countries. Geriatric oncology and palliative care were also topics that sparked great interest during the event. PMID:28487749

  13. Unsteady Aerodynamic Response of Oscillating Contra-Rotating Annular Cascades Part I: Description of Model and Mathematical Formulations

    NASA Astrophysics Data System (ADS)

    Namba, Masanobu; Nishino, Ryohei

    The purpose of this paper is to study the effect of neighboring blade rows on the unsteady aerodynamic response of oscillating cascade blades on the basis of a genuine three-dimensional model. To this end, mathematical formulations based on the lifting surface theory are developed for a pair of contra-rotating annular cascades of oscillating blades. The mechanism of frequency scattering of blade loadings and mode scattering of acoustic waves resulting from interaction between the blade rows in relative rotational motions is mathematically explained. Simultaneous integral equations for all frequency components of blade loadings are derived from the flow tangency condition on the blade surfaces of both blade rows. The validity of the computation codes is verified.

  14. Demonstration of an on-line creep and fatigue monitoring system at the Contra Costa Power Plant

    SciTech Connect

    Copeland, J.F.; Carney, C.E.; Sherlock, T.P. ); Shirmohamadi, M.; Curtis, D.J. ); Scheibel, J.R. )

    1991-01-01

    The objective of this paper to develop an integrated method for evaluating creep-fatigue damage accumulation and crack growth at critical fossil plant steam piping locations using existing instrumentation and available plant operating data. The resulting methodology permits the cumulative damage and structural integrity of steam piping and other components to be monitored and tracked, based on actual plant operating cycles and temperatures. The methodology has been implemented in a software system called Creep-FatiguePro. A prototype system has been installed and tested for a limited number of locations at the Pacific Gas and Electric Company's Contra Costa Power Plant. The results of this pilot plant demonstration show the feasibility of such an on-line monitoring system. Based upon these results, such a system is felt to offer significant cost-benefit advantages in optimizing plant maintenance and life assessment activities.

  15. Health assessment for GBF, Inc. , Dump, Antioch, Contra Costa County, California, Region 9. CERCLIS No. CAD980498562. Preliminary report

    SciTech Connect

    Not Available

    1990-07-18

    The GBF, Inc., Dump site was proposed for the National Priorities List by Update 7. The site is located in Antioch, Contra Costa County, California. The site is currently being operated as a sanitary landfill, but it was used previously for the disposal of chemical wastes. On-site groundwater is contaminated with high concentrations of volatile organic compounds. The extent of off-site groundwater contamination has not been determined. Although the area surrounding the site is serviced by a public water system, several private wells located downgradient of the landfill are used for potable and nonpotable purposes. No contamination of private wells has been reported. Ambient air monitoring at the site has not detected concentrations of air contaminants that pose significant health concerns.

  16. Viruses Infecting Reptiles

    PubMed Central

    Marschang, Rachel E.

    2011-01-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions. PMID:22163336

  17. Viruses infecting reptiles.

    PubMed

    Marschang, Rachel E

    2011-11-01

    A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch's postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.

  18. Building Economic Security Today: making the health-wealth connection in Contra Costa county's maternal and child health programs.

    PubMed

    Parthasarathy, Padmini; Dailey, Dawn E; Young, Maria-Elena D; Lam, Carrie; Pies, Cheri

    2014-02-01

    In recent years, maternal and child health professionals have been seeking approaches to integrating the Life Course Perspective and social determinants of health into their work. In this article, we describe how community input, staff feedback, and evidence from the field that the connection between wealth and health should be addressed compelled the Contra Costa Family, Maternal and Child Health (FMCH) Programs Life Course Initiative to launch Building Economic Security Today (BEST). BEST utilizes innovative strategies to reduce inequities in health outcomes for low-income Contra Costa families by improving their financial security and stability. FMCH Programs' Women, Infants, and Children Program (WIC) conducted BEST financial education classes, and its Medically Vulnerable Infant Program (MVIP) instituted BEST financial assessments during public health nurse home visits. Educational and referral resources were also developed and distributed to all clients. The classes at WIC increased clients' awareness of financial issues and confidence that they could improve their financial situations. WIC clients and staff also gained knowledge about financial resources in the community. MVIP's financial assessments offered clients a new and needed perspective on their financial situations, as well as support around the financial and psychological stresses of caring for a child with special health care needs. BEST offered FMCH Programs staff opportunities to engage in non-traditional, cross-sector partnerships, and gain new knowledge and skills to address a pressing social determinant of health. We learned the value of flexible timelines, maintaining a long view for creating change, and challenging the traditional paradigm of maternal and child health.

  19. Testing for Human Immunodeficiency Virus

    MedlinePlus

    ... education Fact Sheet PFS005: Testing for Human Immunodeficiency Virus AUGUST 2015 • Reasons for Getting Tested • Who Should ... For More Information • Glossary Testing for Human Immunodeficiency Virus Human immunodeficiency virus (HIV) is the virus that ...

  20. Viruses in the sea

    NASA Astrophysics Data System (ADS)

    Suttle, Curtis A.

    2005-09-01

    Viruses exist wherever life is found. They are a major cause of mortality, a driver of global geochemical cycles and a reservoir of the greatest genetic diversity on Earth. In the oceans, viruses probably infect all living things, from bacteria to whales. They affect the form of available nutrients and the termination of algal blooms. Viruses can move between marine and terrestrial reservoirs, raising the spectre of emerging pathogens. Our understanding of the effect of viruses on global systems and processes continues to unfold, overthrowing the idea that viruses and virus-mediated processes are sidebars to global processes.

  1. Viruses in the sea.

    PubMed

    Suttle, Curtis A

    2005-09-15

    Viruses exist wherever life is found. They are a major cause of mortality, a driver of global geochemical cycles and a reservoir of the greatest genetic diversity on Earth. In the oceans, viruses probably infect all living things, from bacteria to whales. They affect the form of available nutrients and the termination of algal blooms. Viruses can move between marine and terrestrial reservoirs, raising the spectre of emerging pathogens. Our understanding of the effect of viruses on global systems and processes continues to unfold, overthrowing the idea that viruses and virus-mediated processes are sidebars to global processes.

  2. Raspberry (Rubus spp.)-Viruses

    USDA-ARS?s Scientific Manuscript database

    There are several important virus diseases of raspberry and black raspberry in the Pacific Northwest. Pollen-borne viruses include Raspberry bushy dwarf virus and Strawberry necrotic shock virus (aka Tobacco streak virus –Rubus isolate or Black raspberry latent virus). Strawberry necrotic shock viru...

  3. Ebola (Ebola Virus Disease)

    MedlinePlus

    ... to Introduce a Vaccine against Ebola Ebola Virus Ecology and Transmission About Ebola Signs and Symptoms Symptoms ... Resources Videos Audio Infographics & Illustrations Factsheets Posters Virus Ecology Graphic File Formats Help: How do I view ...

  4. Quasispecies of dengue virus.

    PubMed

    Kurosu, Takeshi

    2011-12-01

    Pathogenic viruses have RNA genomes that cause acute and chronic infections. These viruses replicate with high mutation rates and exhibit significant genetic diversity, so-called viral quasispecies. Viral quasispecies play an important role in chronic infectious diseases, but little is known about their involvement in acute infectious diseases such as dengue virus (DENV) infection. DENV, the most important human arbovirus, is a causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF). Accumulating observations suggest that DENV exists as an extremely diverse virus population, but its biological significance is unclear. In other virus diseases, quasispecies affect the therapeutic strategies using drugs and vaccines. Here, I describe the quasispecies of DENV and discuss the possible role of quasispecies in the pathogenesis of and therapeutic strategy against DENV infection in comparison with other viruses such as Hepatitis C virus, human immunodeficiency virus type 1, and poliovirus.

  5. Respiratory syncytial virus (RSV)

    MedlinePlus

    Respiratory syncytial virus (RSV) is a very common virus that leads to mild, cold-like symptoms in adults and older healthy children. It can be more serious in young babies, especially those in certain high-risk groups.

  6. West Nile virus

    MedlinePlus

    ... believe West Nile virus is spread when a mosquito bites an infected bird and then bites a ... avoid getting West Nile virus infection after a mosquito bite. People in good health generally do not ...

  7. Hepatitis virus panel

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003558.htm Hepatitis virus panel To use the sharing features on this page, please enable JavaScript. The hepatitis virus panel is a series of blood tests used ...

  8. Human Parainfluenza Viruses

    MedlinePlus

    ... HPIVs Are Not the Same as Influenza (Flu) Viruses People usually get HPIV infections more often in ... hands, and touching objects or surfaces with the viruses on them then touching your mouth, nose, or ...

  9. Respiratory Syncytial Virus Infections

    MedlinePlus

    Respiratory syncytial virus (RSV) causes mild, cold-like symptoms in adults and older healthy children. It can cause serious problems in ... tests can tell if your child has the virus. There is no specific treatment. You should give ...

  10. Viruses and cancer

    SciTech Connect

    Rigby, P.W.J.; Wilkie, N.M.

    1985-01-01

    This book contains 14 selections. Some of the titles are: Immortalising gene(s) encoded by Epstein-Barr Virus; Adenovirus genes involved in transformation. What determines the oncogenic phenotype.; Oncogenesis by mouse mammary tumour virus; and Transforming ras genes.

  11. Live Virus Smallpox Vaccine

    MedlinePlus

    ... Submit What's this? Submit Button The Live Virus Smallpox Vaccine Language: English Español (Spanish) Recommend on Facebook ... the vaccinia virus. Who should NOT get the smallpox vaccine? People most likely to have side effects ...

  12. Advances in virus research

    SciTech Connect

    Maramorosch, K. ); Murphy, F.A. ); Shatkin, A.J. )

    1988-01-01

    This book contains eight chapters. Some of the titles are: Initiation of viral DNA replication; Vaccinia: virus, vector, vaccine; The pre-S region of hepadnavirus envelope proteins; and Archaebacterial viruses.

  13. Viruses and Breast Cancer

    PubMed Central

    Lawson, James S.; Heng, Benjamin

    2010-01-01

    Viruses are the accepted cause of many important cancers including cancers of the cervix and anogenital area, the liver, some lymphomas, head and neck cancers and indirectly human immunodeficiency virus associated cancers. For over 50 years, there have been serious attempts to identify viruses which may have a role in breast cancer. Despite these efforts, the establishment of conclusive evidence for such a role has been elusive. However, the development of extremely sophisticated new experimental techniques has allowed the recent development of evidence that human papilloma virus, Epstein-Barr virus, mouse mammary tumor virus and bovine leukemia virus may each have a role in the causation of human breast cancers. This is potentially good news as effective vaccines are already available to prevent infections from carcinogenic strains of human papilloma virus, which causes cancer of the uterine cervix. PMID:24281093

  14. Tumorigenic DNA viruses

    SciTech Connect

    Klein, G.

    1989-01-01

    The eighth volume of Advances in Viral Oncology focuses on the three major DNA virus groups with a postulated or proven tumorigenic potential: papillomaviruses, animal hepatitis viruses, and the Epstein-Bar virus. In the opening chapters, the contributors analyze the evidence that papillomaviruses and animal hepatitis viruses are involved in tumorigenesis and describe the mechanisms that trigger virus-host cell interactions. A detailed section on the Epstein-Barr virus (EBV) - comprising more than half the book - examines the transcription and mRNA processing patterns of the virus genome; the mechanisms by which EBV infects lymphoid and epithelial cells; the immunological aspects of the virus; the actions of EBV in hosts with Acquired Immune Deficiency Syndrome; and the involvement of EBV in the etiology of Burkitt's lymphoma.

  15. Virus Assembly and Maturation

    NASA Astrophysics Data System (ADS)

    Johnson, John E.

    2004-03-01

    We use two techniques to look at three-dimensional virus structure: electron cryomicroscopy (cryoEM) and X-ray crystallography. Figure 1 is a gallery of virus particles whose structures Timothy Baker, one of my former colleagues at Purdue University, used cryoEM to determine. It illustrates the variety of sizes of icosahedral virus particles. The largest virus particle on this slide is the Herpes simplex virus, around 1200Å in diameter; the smallest we examined was around 250Å in diameter. Viruses bear their genomic information either as positive-sense DNA and RNA, double-strand DNA, double-strand RNA, or negative-strand RNA. Viruses utilize the various structure and function "tactics" seen throughout cell biology to replicate at high levels. Many of the biological principles that we consider general were in fact discovered in the context of viruses ...

  16. Viruses and human cancer

    SciTech Connect

    Gallo, R.C.; Haseltine, W.; Klein, G.; Zur Hausen, H.

    1987-01-01

    This book contains papers on the following topics: Immunology and Epidemiology, Biology and Pathogenesis, Models of Pathogenesis and Treatment, Simian and Bovine Retroviruses, Human Papilloma Viruses, EBV and Herpesvirus, and Hepatitis B Virus.

  17. Avian influenza virus and Newcastle disease virus

    USDA-ARS?s Scientific Manuscript database

    Avian influenza virus (AIV) and Newcastle disease virus (NDV) severely impact poultry egg production. Decreased egg yield and hatchability, as well as misshapen eggs, are often observed during infection with AIV and NDV, even with low-virulence strains or in vaccinated flocks. Data suggest that in...

  18. Nairobi sheep disease virus/Ganjam virus.

    PubMed

    M D, Baron; B, Holzer

    2015-08-01

    Nairobi sheep disease virus (NSDV) is a tick-borne virus which causes a severe disease in sheep and goats, and has been responsible for several outbreaks of disease in East Africa. The virus is also found in the Indian subcontinent, where it is known as Ganjam virus. The virus only spreads through the feeding of competent infected ticks, and is therefore limited in its geographic distribution by the distribution of those ticks, Rhipicephalus appendiculata in Africa and Haemaphysalis intermedia in India. Animals bred in endemic areas do not normally develop disease, and the impact is therefore primarily on animals being moved for trade or breeding purposes. The disease caused by NSDV has similarities to several other ruminant diseases, and laboratory diagnosis is necessary for confirmation. There are published methods for diagnosis based on polymerase chain reaction, for virus growth in cell culture and for other simple diagnostic tests, though none has been commercialised. There is no established vaccine against NSDV, although cell-culture attenuated strains have been developed which show promise and could be put into field trials if it were deemed necessary. The virus is closely related to Crimean-Congo haemorrhagic fever virus, and studies on NSDV may therefore be useful in understanding this important human pathogen.

  19. Avian influenza virus

    USDA-ARS?s Scientific Manuscript database

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  20. Blueberry latent spherical virus

    USDA-ARS?s Scientific Manuscript database

    ‘Blueray’ tissue was mechanically inoculated onto Chenopodium quinoa indicator plants as part of a study to determine virus presence in blueberries at Iwate University, Japan. Plants developed chlorosis indicative of virus presence and after virus purification and genome characterization it was dete...

  1. Computer Virus Protection

    ERIC Educational Resources Information Center

    Rajala, Judith B.

    2004-01-01

    A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having…

  2. Respiratory Syncytial Virus

    MedlinePlus

    ... Your 1- to 2-Year-Old Respiratory Syncytial Virus KidsHealth > For Parents > Respiratory Syncytial Virus A A A What's in this article? About ... RSV When to Call the Doctor en español Virus respiratorio sincitial About RSV Respiratory syncytial (sin-SISH- ...

  3. Avian influenza virus

    USDA-ARS?s Scientific Manuscript database

    Avian influenza (AI) is caused by type A influenza virus, a member of the Orthomyxoviridae family. AI viruses are serologically categorized into 16 hemagglutinin (H1-H16) and 9 neuraminidase (N1-N9) subtypes. All subtypes have been identified in birds. Infections by AI viruses have been reported in ...

  4. Computer Virus Protection

    ERIC Educational Resources Information Center

    Rajala, Judith B.

    2004-01-01

    A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having…

  5. Influenza viruses: an introduction.

    PubMed

    Kawaoka, Yoshihiro; Neumann, Gabriele

    2012-01-01

    We provide a brief introduction into the genome organization, life cycle, pathogenicity, and host range of influenza A viruses. We also briefly summarize influenza pandemics and currently available measures to control influenza virus outbreaks, including vaccines and antiviral compounds to influenza viruses.

  6. The taxonomy of viruses should include viruses.

    PubMed

    Calisher, Charles H

    2016-05-01

    Having lost sight of its goal, the International Committee on Taxonomy of Viruses has redoubled its efforts. That goal is to arrive at a consensus regarding virus classification, i.e., proper placement of viruses in a hierarchical taxonomic scheme; not an easy task given the wide variety of recognized viruses. Rather than suggesting a continuation of the bureaucratic machinations of the past, this opinion piece is a call for insertion of common sense in sorting out the avalanche of information already, and soon-to-be, accrued data. In this way information about viruses ideally would be taxonomically correct as well as useful to working virologists and journal editors, rather than being lost, minimized, or ignored.

  7. [Management of hepatitis B virus and hepatitis C virus infection in chronic kidney failure].

    PubMed

    Vallet-Pichard, Anaïs; Pol, Stanislas

    2015-11-01

    Chronic infections by hepatitis B (HBV) and C virus (HCV) result in diagnosis and therapeutic issues in dialysis and kidney recipients patients. The exposure to nosocomial, including blood transfusion, risk explains the high prevalence of HBV and HCV infection in this setting. Chronic infection reduces the survival of both patients and allografts, including a specific risk of de novo glomerulonephritis. Cirrhosis was considered as a contra-indication to renal transplantation given the high risk of decompensation and death, questionning the indication of a combined liver and kidney transplantation. Thus, it is mandatory to screen HBV and HCV markers in all dialysis patients, whether or not they are candidates to transplantation. Liver biopsy allows evaluating the severity of the liver disease since the noninvasive markers of fibrosis appear to be less accurate in "renal" patients than in the general population and to better define antiviral therapeutic indications. HCV treatment was mainly based on pegylated interferon α (and low doses of ribavirin), which is contra-indicated in kidney recipients given the risk of graft rejection; HCV treatment is now based on the use of oral direct acting antivirals, which are very potent and well tolerated. HBV replication is now easily suppressed by second-generation nucleos(t)tidic analogues (entecavir and tenofovir), which will be indicated in all the dialysis patients with significant fibrosis (F2,3 or 4 according to the Metavir scoring system) and in any candidate to renal transplantation and to any HBsAg-positive kidney recipients. The best treatment remains preventive by anti-HBV vaccination for HBV and by the respect of universal hygiene rules for HCV. Copyright © 2015. Published by Elsevier SAS.

  8. Blueberry (Vaccinium corymbosum)-Virus Diseases

    USDA-ARS?s Scientific Manuscript database

    At least six viruses have been found in highbush blueberry plantings in the Pacific Northwest: Blueberry mosaic virus, Blueberry red ringspot virus, Blueberry scorch virus, Blueberry shock virus, Tobacco ringspot virus, and Tomato ringspot virus. Six other virus and virus-like diseases of highbush b...

  9. [Viruses as biological weapons].

    PubMed

    Akçali, Alper

    2005-07-01

    The destruction made by nuclear, biological and chemical weapons used by governments and terrorist groups in the near history is posing anxiety and fear for human being. Rumour about the possible use of these agents leads to the development of serious negative effects on populations. Since there are no vaccine and therapy for most viral agents and cost of production as biological weapons is low, interest rate is rising for viruses. In this review, general characteristics, diagnosis, therapy and protective measures for viral agents such as variola virus, hemorrhagic fever viruses, encephalitis viruses, Hantaviruses and Nipah viruses, those can be used as biological weapon, have been summarized.

  10. Viruses and marine pollution.

    PubMed

    Danovaro, R; Armeni, M; Corinaldesi, C; Mei, M L

    2003-03-01

    This short review summarises the present knowledge on pollutant impacts on marine viruses, virus-host systems and their potential ecological implications. Excess nutrients from sewage and river effluents are a primary cause of marine eutrophication and mucilage formation, often related to the development of large viral assemblages. At the same time, hydrocarbons, polychlorinated biphenyl and pesticides alter ecosystem functioning and can determinate changes in the virus-host interactions, thus increasing the potential of viral infection. All these pollutants might have synergistic effects on the virus-host system and are able to induce prophage, thus increasing the impact of viruses on marine ecosystems.

  11. Viruses of asparagus.

    PubMed

    Tomassoli, Laura; Tiberini, Antonio; Vetten, Heinrich-Josef

    2012-01-01

    The current knowledge on viruses infecting asparagus (Asparagus officinalis) is reviewed. Over half a century, nine virus species belonging to the genera Ilarvirus, Cucumovirus, Nepovirus, Tobamovirus, Potexvirus, and Potyvirus have been found in this crop. The potyvirus Asparagus virus 1 (AV1) and the ilarvirus Asparagus virus 2 (AV2) are widespread and negatively affect the economic life of asparagus crops reducing yield and increasing the susceptibility to biotic and abiotic stress. The main properties and epidemiology of AV1 and AV2 as well as diagnostic techniques for their detection and identification are described. Minor viruses and control are briefly outlined. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Equine influenza virus.

    PubMed

    Landolt, Gabriele A

    2014-12-01

    For decades the horse has been viewed as an isolated or "dead-end" host for influenza A viruses, with equine influenza virus being considered as relatively stable genetically. Although equine influenza viruses are genetically more stable than those of human lineage, they are by no means in evolutionary stasis. Moreover, recent transmission of equine-lineage influenza viruses to dogs also challenges the horse's status as a dead-end host. This article reviews recent developments in the epidemiology and evolution of equine influenza virus. In addition, the clinical presentation of equine influenza infection, diagnostic techniques, and vaccine recommendations are briefly summarized.

  13. Avian influenza virus.

    PubMed

    Lee, Chang-Won; Saif, Yehia M

    2009-07-01

    Avian influenza viruses do not typically replicate efficiently in humans, indicating direct transmission of avian influenza virus to humans is unlikely. However, since 1997, several cases of human infections with different subtypes (H5N1, H7N7, and H9N2) of avian influenza viruses have been identified and raised the pandemic potential of avian influenza virus in humans. Although circumstantial evidence of human to human transmission exists, the novel avian-origin influenza viruses isolated from humans lack the ability to transmit efficiently from person-to-person. However, the on-going human infection with avian-origin H5N1 viruses increases the likelihood of the generation of human-adapted avian influenza virus with pandemic potential. Thus, a better understanding of the biological and genetic basis of host restriction of influenza viruses is a critical factor in determining whether the introduction of a novel influenza virus into the human population will result in a pandemic. In this article, we review current knowledge of type A influenza virus in which all avian influenza viruses are categorized.

  14. Virus Evolution Serial

    SciTech Connect

    Vassilevska, Tanya

    2015-01-05

    This is the first code, designed to run on a desktop, which models the intracellular replication and the cell-to-cell infection and demonstrates virus evolution at the molecular level. This code simulates the infection of a population of "idealized biological cells" (represented as objects that do not divide or have metabolism) with "virus" (represented by its genetic sequence), the replication and simultaneous mutation of the virus which leads to evolution of the population of genetically diverse viruses. The code is built to simulate single-stranded RNA viruses. The input for the code is 1. the number of biological cells in the culture, 2. the initial composition of the virus population, 3. the reference genome of the RNA virus, 4. the coordinates of the genome regions and their significance and, 5. parameters determining the dynamics of virus replication, such as the mutation rate. The simulation ends when all cells have been infected or when no more infections occurs after a given number of attempts. The code has the ability to simulate the evolution of the virus in serial passage of cell "cultures", i.e. after the end of a simulation, a new one is immediately scheduled with a new culture of infected cells. The code outputs characteristics of the resulting virus population dynamics and genetic composition of the virus population, such as the top dominant genomes, percentage of a genome with specific characteristics.

  15. Serodiagnosis for Tumor Viruses

    PubMed Central

    Morrison, Brian J.; Labo, Nazzarena; Miley, Wendell J.; Whitby, Denise

    2015-01-01

    The known human tumor viruses include the DNA viruses Epstein-Barr virus, Kaposi sarcoma herpesvirus, Merkel cell polyomavirus, human papillomavirus, and hepatitis B virus. RNA tumor viruses include Human T-cell lymphotrophic virus type-1 and hepatitis C virus. The serological identification of antigens/antibodies in plasma serum is a rapidly progressing field with utility for both scientists and clinicians. Serology is useful for conducting seroepidemiology studies and to inform on the pathogenesis and host immune response to a particular viral agent. Clinically, serology is useful for diagnosing current or past infection and for aiding in clinical management decisions. Serology is useful for screening blood donations for infectious agents and for monitoring the outcome of vaccination against these viruses. Serodiagnosis of human tumor viruses has improved in recent years with increased specificity and sensitivity of the assays, as well as reductions in cost and the ability to assess multiple antibody/antigens in single assays. Serodiagnosis of tumor viruses plays an important role in our understanding of the prevalence and transmission of these viruses and ultimately in the ability to develop treatments/preventions for these globally important diseases. PMID:25843726

  16. Virus transmission via food.

    PubMed

    Cliver, D O

    1997-01-01

    Viruses are transmitted to humans via foods as a result of direct or indirect contamination of the foods with human faeces. Viruses transmitted by a faecal-oral route are not strongly dependent on foods as vehicles of transmission, but viruses are important among agents of foodborne disease. Vehicles are most often molluscs from contaminated waters, but many other foods are contaminated directly by infected persons. The viruses most often foodborne are the hepatitis A virus and the Norwalk-like gastroenteritis viruses. Detection methods for these viruses in foods are very difficult and costly; the methods are not routine. Indicators that would rapidly and reliably suggest the presence of viral contamination of foods are still being sought. Contamination can be prevented by keeping faeces out of food or by treating vehicles such as water in order to inactivate virus that might be carried to food in this way. Virus cannot multiply in food, but can usually be inactivated by adequate heating. Other methods of inactivating viruses within a food are relatively unreliable, but viruses in water and on exposed surfaces can be inactivated with ultraviolet light or with strong oxidizing agents.

  17. Application of an Aligned and Unaligned Signal Processing Technique to Investigate Tones and Broadband Noise in Fan and Contra-Rotating Open Rotor Acoustic Spectra

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton; Hultgren, Lennart S.

    2015-01-01

    The study of noise from a two-shaft contra-rotating open rotor (CROR) is challenging since the shafts are not phase locked in most cases. Consequently, phase averaging of the acoustic data keyed to a single shaft rotation speed is not meaningful. An unaligned spectrum procedure that was developed to estimate a signal coherence threshold and reveal concealed spectral lines in turbofan engine combustion noise is applied to fan and CROR acoustic data in this paper.

  18. Application of an Aligned and Unaligned Signal Processing Technique to Investigate Tones and Broadband Noise in Fan and Contra-Rotating Open Rotor Acoustic Spectra

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton; Hultgren, Lennart S.

    2015-01-01

    The study of noise from a two-shaft contra-rotating open rotor (CROR) is challenging since the shafts are not phase locked in most cases. Consequently, phase averaging of the acoustic data keyed to a single shaft rotation speed is not meaningful. An unaligned spectrum procedure that was developed to estimate a signal coherence threshold and reveal concealed spectral lines in turbofan engine combustion noise is applied to fan and CROR acoustic data in this paper.

  19. Virus, Oncolytic virus and Human Prostate Cancer.

    PubMed

    Liu, Guang Bin; Zhao, Liang; Zhang, Lifang; Zhao, Kong-Nan

    2016-12-15

    Prostate cancer (PCa), a disease, is characterized by abnormal cell growth in the prostate - a gland in the male reproductive system. PCa is one of the leading causes of cancer death among men of all races. Although older age and a family history of the disease have been recognized as the risk factors of PCa, the cause of this cancer remains unclear. Mounting evidence suggests that infections with various viruses are causally linked to PCa pathogenesis. Published studies have provided strong evidence that at least two viruses (RXMV and HPV) contribute to prostate tumourigenicity and impact on the survival of patients with malignant PCa. Traditional therapies including chemotherapy and radiotherapy are unable to distinguish cancer cells from normal cells, which are a significant drawback and leads to toxicities for PCa patients undergoing treatment. So far, few other options are available for treating patients with advanced PCa. Virotherapy is being developed to be a novel therapy for cancers, which uses oncotropic and oncolytic viruses with their abilities to find and destroy malignant cells in the body. For PCa treatment, oncolytic virotherapy appears to be much more attractive, which uses live viruses to selectively kill cancer cells. Oncolytic viruses can be genetically engineered to induce cancer cell lysis through virus replication and expression of cytotoxic proteins. As oncolytic viruses are a relatively new class of anti-cancer immunotherapy agents, several important barriers still exist on the road to the use of oncolytic viruses for PCa therapy. In this review, we first discuss the controversy of the contribution of virus infection to PCa, and subsequently summarize the development of oncolytic virotherapy for PCa in the past several years.

  20. La guerra de los Estados Unidos contra la inmigración. Efectos paradójicos1

    PubMed Central

    Massey, Douglas S.; Pren, Karen A.

    2016-01-01

    Resumen A finales de la década de los cincuenta, Estados Unidos permitía la entrada de aproximadamente medio millón de inmigrantes mexicanos al año, de los cuales 450.000 entraban con visados de trabajo temporal y 50.000 llegaban con visados de residentes permanentes. A mediados de los años sesenta, los cambios en la política migratoria de Estados Unidos realizados en nombre de los derechos civiles redujeron drásticamente las oportunidades de entrada legal a Estados Unidos. Se eliminaron los visados de trabajo temporal y se limitaron los visados de residentes a 20.000 por año. Con las oportunidades de entrada legal restringidas, los flujos migratorios ya establecidos simplemente continuaron, fuera de los límites legales, dando comienzo a una inesperada reacción en cadena de eventos que culminaron en una guerra total contra los inmigrantes y el rápido crecimiento -sin precedentes- de población residente no autorizada en Estados Unidos. El presente artículo demuestra que el aumento de inmigración indocumentada en los Estados Unidos y el crecimiento de la población sin papeles son un producto de políticas migratorias y fronterizas mal concebidas. PMID:27076695

  1. [The great virus comeback].

    PubMed

    Forterre, Patrick

    2013-01-01

    Viruses have been considered for a long time as by-products of biological evolution. This view is changing now as a result of several recent discoveries. Viral ecologists have shown that viral particles are the most abundant biological entities on our planet, whereas metagenomic analyses have revealed an unexpected abundance and diversity of viral genes in the biosphere. Comparative genomics have highlighted the uniqueness of viral sequences, in contradiction with the traditional view of viruses as pickpockets of cellular genes. On the contrary, cellular genomes, especially eukaryotic ones, turned out to be full of genes derived from viruses or related elements (plasmids, transposons, retroelements and so on). The discovery of unusual viruses infecting archaea has shown that the viral world is much more diverse than previously thought, ruining the traditional dichotomy between bacteriophages and viruses. Finally, the discovery of giant viruses has blurred the traditional image of viruses as small entities. Furthermore, essential clues on virus history have been obtained in the last ten years. In particular, structural analyses of capsid proteins have uncovered deeply rooted homologies between viruses infecting different cellular domains, suggesting that viruses originated before the last universal common ancestor (LUCA). These studies have shown that several lineages of viruses originated independently, i.e., viruses are polyphyletic. From the time of LUCA, viruses have coevolved with their hosts, and viral lineages can be viewed as lianas wrapping around the trunk, branches and leaves of the tree of life. Although viruses are very diverse, with genomes encoding from one to more than one thousand proteins, they can all be simply defined as organisms producing virions. Virions themselves can be defined as infectious particles made of at least one protein associated with the viral nucleic acid, endowed with the capability to protect the viral genome and ensure its

  2. Lifestyles of plant viruses

    PubMed Central

    Roossinck, Marilyn J.

    2010-01-01

    The vast majority of well-characterized eukaryotic viruses are those that cause acute or chronic infections in humans and domestic plants and animals. However, asymptomatic persistent viruses have been described in animals, and are thought to be sources for emerging acute viruses. Although not previously described in these terms, there are also many viruses of plants that maintain a persistent lifestyle. They have been largely ignored because they do not generally cause disease. The persistent viruses in plants belong to the family Partitiviridae or the genus Endornavirus. These groups also have members that infect fungi. Phylogenetic analysis of the partitivirus RNA-dependent RNA polymerase genes suggests that these viruses have been transmitted between plants and fungi. Additional families of viruses traditionally thought to be fungal viruses are also found frequently in plants, and may represent a similar scenario of persistent lifestyles, and some acute or chronic viruses of crop plants may maintain a persistent lifestyle in wild plants. Persistent, chronic and acute lifestyles of plant viruses are contrasted from both a functional and evolutionary perspective, and the potential role of these lifestyles in host evolution is discussed. PMID:20478885

  3. Postmortem stability of Ebola virus.

    PubMed

    Prescott, Joseph; Bushmaker, Trenton; Fischer, Robert; Miazgowicz, Kerri; Judson, Seth; Munster, Vincent J

    2015-05-01

    The ongoing Ebola virus outbreak in West Africa has highlighted questions regarding stability of the virus and detection of RNA from corpses. We used Ebola virus-infected macaques to model humans who died of Ebola virus disease. Viable virus was isolated <7 days posteuthanasia; viral RNA was detectable for 10 weeks.

  4. RNA Viruses Infecting Pest Insects

    USDA-ARS?s Scientific Manuscript database

    RNA viruses are viruses whose genetic material is ribonucleic acid (RNA). RNA viruses may be double or single-stranded based on the type of RNA they contain. Single-stranded RNA viruses can be further grouped into negative sense or positive-sense viruses according to the polarity of their RNA. Fur...

  5. Other Viruses and Viruslike Agents

    USDA-ARS?s Scientific Manuscript database

    The diseases reported under 'Virus and Virus-like Agents' in the first volume of this compendium, with the exception of Cherry rasp leaf virus and Rubus chinese seed-borne virus, should be considered oddities since there are no known type isolates available for these reported viruses. Without a po...

  6. Using community participation to assess acceptability of "Contra Caries", a theory-based, promotora-led oral health education program for rural Latino parents: a mixed methods study.

    PubMed

    Hoeft, Kristin S; Rios, Sarah M; Pantoja Guzman, Estela; Barker, Judith C

    2015-09-03

    Latino children experience more prevalent and severe tooth decay than non-Hispanic white and non-Hispanic black children. Few theory-based, evaluated and culturally appropriate interventions target parents of this vulnerable population. To fill this gap, the Contra Caries Oral Health Education Program, a theory-based, promotora-led education program for low-income, Spanish-speaking parents of children aged 1-5 years, was developed. This article describes qualitative findings of the acceptability of curriculum content and activities, presents the process of refinement of the curriculum through engaging the target population and promotoras, and presents results from the evaluation assessing the acceptability of the curriculum once implemented. Focus groups were conducted with low-income Spanish-speaking parents of children 1-5 years living in a city in an agricultural area of California. Interviews were digitally recorded, translated and transcribed, checked for accuracy and the resulting data was thematically coded and analyzed using a social constructionist approach. The Contra Caries Oral Health Education Program was then implemented with a separate but similar sample, and after completing the program, participants were administered surveys asking about acceptability and favorite activities of the education program. Data were entered into a database, checked for accuracy, open-ended questions were categorized, and responses to close-ended questions counted. Twelve focus groups were conducted (N = 51), 105 parents attended the Contra Caries Oral Health Education Program, and 83 parents filled out surveys. Complete attendance and retention was high (89% and 90%, respectively). This study found that their children's oral health is a high priority. Parents were not only interested in, but actually attended classes focused on increasing their knowledge and skills with respect to early childhood oral health. The Contra Caries content and format was perceived as

  7. Viruses within animal genomes.

    PubMed

    De Brognier, A; Willems, L

    2016-04-01

    Viruses and their hosts can co-evolve to reach a fragile equilibrium that allows the survival of both. An excess of pathogenicity in the absence of a reservoir would be detrimental to virus survival. A significant proportion of all animal genomes has been shaped by the insertion of viruses that subsequently became 'fossilised'. Most endogenous viruses have lost the capacity to replicate via an infectious cycle and now replicate passively. The insertion of endogenous viruses has contributed to the evolution of animal genomes, for example in the reproductive biology of mammals. However, spontaneous viral integration still occasionally occurs in a number of virus-host systems. This constitutes a potential risk to host survival but also provides an opportunity for diversification and evolution.

  8. Water system virus detection

    NASA Technical Reports Server (NTRS)

    Fraser, A. S.; Wells, A. F.; Tenoso, H. J. (Inventor)

    1978-01-01

    The performance of a waste water reclamation system is monitored by introducing a non-pathogenic marker virus, bacteriophage F2, into the waste-water prior to treatment and, thereafter, testing the reclaimed water for the presence of the marker virus. A test sample is first concentrated by absorbing any marker virus onto a cellulose acetate filter in the presence of a trivalent cation at low pH and then flushing the filter with a limited quantity of a glycine buffer solution to desorb any marker virus present on the filter. Photo-optical detection of indirect passive immune agglutination by polystyrene beads indicates the performance of the water reclamation system in removing the marker virus. A closed system provides for concentrating any marker virus, initiating and monitoring the passive immune agglutination reaction, and then flushing the system to prepare for another sample.

  9. DNA Virus Replication Compartments

    PubMed Central

    Schmid, Melanie; Speiseder, Thomas; Dobner, Thomas

    2014-01-01

    Viruses employ a variety of strategies to usurp and control cellular activities through the orchestrated recruitment of macromolecules to specific cytoplasmic or nuclear compartments. Formation of such specialized virus-induced cellular microenvironments, which have been termed viroplasms, virus factories, or virus replication centers, complexes, or compartments, depends on molecular interactions between viral and cellular factors that participate in viral genome expression and replication and are in some cases associated with sites of virion assembly. These virus-induced compartments function not only to recruit and concentrate factors required for essential steps of the viral replication cycle but also to control the cellular mechanisms of antiviral defense. In this review, we summarize characteristic features of viral replication compartments from different virus families and discuss similarities in the viral and cellular activities that are associated with their assembly and the functions they facilitate for viral replication. PMID:24257611

  10. Mechanical properties of viruses.

    PubMed

    de Pablo, Pedro J; Mateu, Mauricio G

    2013-01-01

    Structural biology techniques have greatly contributed to unveil the relationships between structure, properties and functions of viruses. In recent years, classic structural approaches are being complemented by single-molecule techniques such as atomic force microscopy and optical tweezers to study physical properties and functions of viral particles that are not accessible to classic structural techniques. Among these features are mechanical properties such as stiffness, intrinsic elasticity, tensile strength and material fatigue. The field of virus mechanics is contributing to materials science by investigating some physical parameters of "soft" biological matter and biological nano-objects. Virus mechanics studies are also starting to unveil the biological implications of physical properties of viruses. Growing evidence indicate that viruses are subjected to internal and external forces, and that they may have adapted to withstand and even use those forces. This chapter describes what is known on the mechanical properties of virus particles, their structural determinants, and possible biological implications, of which several examples are provided.

  11. Constructing computer virus phylogenies

    SciTech Connect

    Goldberg, L.A.; Goldberg, P.W.; Phillips, C.A.; Sorkin, G.B.

    1996-03-01

    There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses--a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is ``invented`` only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimal number of edges. In general, this optimization problem cannot be solved in quasi-polynomial time unless NQP=QP; we present positive and negative results for associated approximated problems. When tree solutions exist, they can be constructed and randomly sampled in polynomial time.

  12. Filamentous Influenza Viruses

    PubMed Central

    Badham, Matthew D.; Rossman, Jeremy S.

    2016-01-01

    Influenza A virus is a pathogen of global medical importance causing significant health and socio-economic costs every year. Influenza virus is an unusual pathogen in that it is pleomorphic, capable of forming virions ranging in shape from spherical to filamentous. Despite decades of research on the influenza virus, much remains unknown about the formation of filamentous influenza viruses and their role in the viral replication cycle. Here, we discuss what is known about influenza virus assembly and budding, focusing on the viral and host factors that are involved in the determination of viral morphology. Whilst the biological function of the filamentous morphology remains unknown, recent results suggest a role in facilitating viral spread in vivo. We discuss these results and speculate on the consequences of viral morphology during influenza virus infection of the human respiratory tract. PMID:28042529

  13. Viruses of lower vertebrates.

    PubMed

    Essbauer, S; Ahne, W

    2001-08-01

    Viruses of lower vertebrates recently became a field of interest to the public due to increasing epizootics and economic losses of poikilothermic animals. These were reported worldwide from both wildlife and collections of aquatic poikilothermic animals. Several RNA and DNA viruses infecting fish, amphibians and reptiles have been studied intensively during the last 20 years. Many of these viruses induce diseases resulting in important economic losses of lower vertebrates, especially in fish aquaculture. In addition, some of the DNA viruses seem to be emerging pathogens involved in the worldwide decline in wildlife. Irido-, herpes- and polyomavirus infections may be involved in the reduction in the numbers of endangered amphibian and reptile species. In this context the knowledge of several important RNA viruses such as orthomyxo-, paramyxo-, rhabdo-, retro-, corona-, calici-, toga-, picorna-, noda-, reo- and birnaviruses, and DNA viruses such as parvo-, irido-, herpes-, adeno-, polyoma- and poxviruses, is described in this review.

  14. Honey bee viruses.

    PubMed

    Chen, Yan Ping; Siede, Reinhold

    2007-01-01

    Viruses are significant threats to the health and well-being of the honey bee, Apis mellifera. To alleviate the threats posed by these invasive organisms, a better understanding of bee viral infections will be of crucial importance in developing effective and environmentally benign disease control strategies. Although knowledge of honey bee viruses has been accumulated considerably in the past three decades, a comprehensive review to compile the various aspects of bee viruses at the molecular level has not been reported. This chapter summarizes recent progress in the understanding of the morphology, genome organization, transmission, epidemiology, and pathogenesis of honey bee viruses as well as their interactions with their honey bee hosts. The future prospects of research of honey bee viruses are also discussed in detail. The chapter has been designed to provide researchers in the field with updated information about honey bee viruses and to serve as a starting point for future research.

  15. Viruses in Antarctic lakes

    NASA Technical Reports Server (NTRS)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  16. Viruses in Antarctic lakes

    NASA Technical Reports Server (NTRS)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  17. Zika virus - an overview.

    PubMed

    Zanluca, Camila; Dos Santos, Claudia Nunes Duarte

    2016-05-01

    Zika virus (ZIKV) is currently one of the most important emerging viruses in the world. Recently, it has caused outbreaks and epidemics, and has been associated with severe clinical manifestations and congenital malformations. However to date, little is known about the pathogenicity of the virus and the consequences of ZIKV infection. In this paper, we provide an overview of the current knowledge on ZIKV. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  18. Zika virus infection.

    PubMed

    Pougnet, Laurence; Thill, Chloé; Pougnet, Richard; Auvinet, Henri; Giacardi, Christophe; Drouillard, Isabelle

    2016-12-01

    A 21-year old woman from New-Caledonia had 40 ̊C fever with vomiting, arthralgia, myalgia, and measles-like rash. Etiological analyses showed primary infection with Zika virus. Because of severe clinical presentation, she was hospitalized in the intensive care unit of the Brest military Hospital. Zika virus is mainly transmitted by Aedes mosquitoes. If they settle in Metropolitan France, Zika virus might also spread there.

  19. Thermal Inactivation of Viruses

    DTIC Science & Technology

    1977-10-01

    Hammon. 1966. Studies on Japanese B encephalitis virus vaccines from tissue culture. VI. Development of a hamster kidney tissue culture inactivated... tissue culture passage, storage, temperature and drying on viability of SE polyoma virus. Exper. Biol. and Hed. Proc. of the Soc. for Exper. Biol...studies of heated tissue suspensions containing foot- and-mouth disease virus. Amer. J. Vet. Res. 20:510-521. Dupre’, M. V., and M. Frobisher. 1966

  20. The human oncogenic viruses

    SciTech Connect

    Luderer, A.A.; Weetall, H.H

    1986-01-01

    This book contains eight selections. The titles are: Cytogenetics of the Leukemias and Lymphomas; Cytogenetics of Solid Tumors: Renal Cell Carcinoma, Malignant Melanoma, Retinoblastoma, and Wilms' Tumor; Elucidation of a Normal Function for a Human Proto-Oncogene; Detection of HSV-2 Genes and Gene Products in Cervical Neoplasia; Papillomaviruses in Anogennital Neoplasms; Human Epstein-Barr Virus and Cancer; Hepatitis B Virus and Hepatocellular Carcinoma; and Kaposi's Sarcoma: Acquired Immunodeficiency Syndrome (AIDS) and Associated Viruses.

  1. Broadband Respiratory Virus Surveillance

    DTIC Science & Technology

    2011-10-01

    HSV – Herpes Simplex Virus LOD – Limit of Detection PCR – Polymerase Chain Reaction PIV – Parainfluenza viruses 37 PRMS – Pacific Regional Medical...the RVS assay was determined by testing 109 pre-characterized samples collected at TAMC. This included 20 adenovirus, 20 RSV, 20 PIV, 19 Herpes ... Simplex Virus (HSV) and 19 Enterovirus 7 positive as well as 11 HSV negative specimens as determined by the TAMC Department of Pathology’s current gold

  2. Water system virus detection

    NASA Technical Reports Server (NTRS)

    Fraser, A. S.; Wells, A. F.; Tenoso, H. J.

    1975-01-01

    A monitoring system developed to test the capability of a water recovery system to reject the passage of viruses into the recovered water is described. A nonpathogenic marker virus, bacteriophage F2, is fed into the process stream before the recovery unit and the reclaimed water is assayed for its presence. Detection of the marker virus consists of two major components, concentration and isolation of the marker virus, and detection of the marker virus. The concentration system involves adsorption of virus to cellulose acetate filters in the presence of trivalent cations and low pH with subsequent desorption of the virus using volumes of high pH buffer. The detection of the virus is performed by a passive immune agglutination test utilizing specially prepared polystyrene particles. An engineering preliminary design was performed as a parallel effort to the laboratory development of the marker virus test system. Engineering schematics and drawings of a fully functional laboratory prototype capable of zero-G operation are presented. The instrument consists of reagent pump/metering system, reagent storage containers, a filter concentrator, an incubation/detector system, and an electronic readout and control system.

  3. Viruses infecting marine molluscs.

    PubMed

    Arzul, Isabelle; Corbeil, Serge; Morga, Benjamin; Renault, Tristan

    2017-02-09

    Although a wide range of viruses have been reported in marine molluscs, most of these reports rely on ultrastructural examination and few of these viruses have been fully characterized. The lack of marine mollusc cell lines restricts virus isolation capacities and subsequent characterization works. Our current knowledge is mostly restricted to viruses affecting farmed species such as oysters Crassostrea gigas, abalone Haliotis diversicolor supertexta or the scallop Chlamys farreri. Molecular approaches which are needed to identify virus affiliation have been carried out for a small number of viruses, most of them belonging to the Herpesviridae and birnaviridae families. These last years, the use of New Generation Sequencing approach has allowed increasing the number of sequenced viral genomes and has improved our capacity to investigate the diversity of viruses infecting marine molluscs. This new information has in turn allowed designing more efficient diagnostic tools. Moreover, the development of experimental infection protocols has answered some questions regarding the pathogenesis of these viruses and their interactions with their hosts. Control and management of viral diseases in molluscs mostly involve active surveillance, implementation of effective bio security measures and development of breeding programs. However factors triggering pathogen development and the life cycle and status of the viruses outside their mollusc hosts still need further investigations.

  4. Rabies virus receptors.

    PubMed

    Lafon, Monique

    2005-02-01

    There is convincing in vitro evidence that the muscular form of the nicotinic acetylcholine receptor (nAChR), the neuronal cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR) bind rabies virus and/or facilitate rabies virus entry into cells. Other components of the cell membrane, such as gangliosides, may also participate in the entry of rabies virus. However, little is known of the role of these molecules in vivo. This review proposes a speculative model that accounts for the role of these different molecules in entry and trafficking of rabies virus into the nervous system.

  5. Viruses in artichoke.

    PubMed

    Gallitelli, Donato; Mascia, Tiziana; Martelli, Giovanni P

    2012-01-01

    Most of the 25 viruses found in globe artichoke (Cynara scolymus L.) and cardoon (Cynara cardunculus L.) were recorded from Europe and the Mediterranean basin, where they decrease both the productivity and the quality of the crop. Although, sometimes, these viruses are agents of diseases of different severity, most often their infections are symptomless. These conditions have contributed to spread virus-infected material since farmers multiply traditional artichoke types vegetatively with no effective selection of virus-free plants. This review reports the main properties of these viruses and the techniques used for their detection and identification. ELISA kits are commercially available for most of the viruses addressed in this review but have seldom been used for their detection in artichoke. Conversely, nucleic acid-based diagnostic reagents, some of which are commercially available, have successfully been employed to identify some viruses in artichoke sap. Control measures mainly use virus-free stocks for new plantations. A combined procedure of meristem-tip culture and thermotherapy proved useful for producing virus-free regenerants of the reflowering southern Italian cultivar Brindisino, which kept earliness and typical heads shape. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Chikungunya Virus, Southeastern France

    PubMed Central

    Caro, Valérie; Plumet, Sébastien; Thiberge, Jean-Michel; Souarès, Yvan; Failloux, Anna-Bella; Tolou, Hugues J.; Budelot, Michel; Cosserat, Didier; Leparc-Goffart, Isabelle; Desprès, Philippe

    2011-01-01

    In September 2010, autochthonous transmission of chikungunya virus was recorded in southeastern France, where the Aedes albopictus mosquito vector is present. Sequence analysis of the viral genomes of imported and autochthonous isolates indicated new features for the potential emergence and spread of the virus in Europe. PMID:21529410

  7. Viruses in reptiles.

    PubMed

    Ariel, Ellen

    2011-09-21

    The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself.

  8. West Nile Virus

    MedlinePlus

    ... spread by mosquitoes. Mosquitoes become infected by biting birds that carry the virus. People can get West Nile virus when an infected mosquito bites them. This happens most often in the warm-weather months of spring, summer and early fall. You ...

  9. Blueberry virus A

    USDA-ARS?s Scientific Manuscript database

    Leaf yellowing on highbush blueberry ‘Spartan’ prompted Isogai et al. to investigate whether a virus was the causal agent of the disorder. After double-stranded RNA extraction from symptomatic material they identified a single band of 17 Kb, indicative of virus infection. Shotgun cloning and sequenc...

  10. Diseases caused by viruses

    USDA-ARS?s Scientific Manuscript database

    Corn viruses are important disease agents worldwide that can be difficult to identify and diagnose. Previously undescribed viruses of corn also emerge periodically and their distributions and importance changes over time. The Compendium of Corn Diseases is a valuable tool for pre-diagnosis of diseas...

  11. Positive reinforcement for viruses.

    PubMed

    Vigant, Frederic; Jung, Michael; Lee, Benhur

    2010-10-29

    Virus-cell membrane fusion requires a critical transition from positive to negative membrane curvature. St. Vincent et al. (2010), in PNAS, designed a class of antivirals that targets this transition. These rigid amphipathic fusion inhibitors are active against an array of enveloped viruses.

  12. Rift Valley Fever Virus

    USDA-ARS?s Scientific Manuscript database

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  13. Equine Arteritis Virus

    USDA-ARS?s Scientific Manuscript database

    03. Nidovirales : 03.004. Arteriviridae : 03.004.0. {03.004.0. unknown} : 03.004.0.01. Arterivirus : 03.004.0.01.001. Equine arteritis virus will be published online. The article details the phenotypic and genotypic makeup of equine arteritis virus (EAV), and summarizes its biological properties....

  14. Usutu Virus, Italy, 1996

    PubMed Central

    Bakonyi, Tamás; Rossi, Giacomo; Mani, Paolo; Nowotny, Norbert

    2013-01-01

    Retrospective analysis of archived tissue samples from bird deaths in the Tuscany region of Italy in 1996 identified Usutu virus. Partial sequencing confirmed identity with the 2001 Vienna strain and provided evidence for a much earlier introduction of this virus into Europe than previously assumed. PMID:23347844

  15. Avian influenza virus

    USDA-ARS?s Scientific Manuscript database

    Avian influenza virus (AIV) is type A influenza that is adapted to avian host species. Although the virus can be isolated from numerous avian species, the natural host reservoir species are dabbling ducks, shorebirds and gulls. Domestic poultry species (poultry being defined as birds that are rais...

  16. Zika Virus Disease.

    PubMed

    Slenczka, Werner

    2016-06-01

    The history of Zika virus disease serves as a paradigm of a typical emerging viral infection. Zika virus disease, a mosquito-borne flavivirus, was first isolated in 1947 in the Zika forest of Uganda. The same virus was also isolated from jungle-dwelling mosquitoes (Aedes [Stegomyia] africanus). In many areas of Africa and South Asia human infections with Zika virus were detected by both serology and virus isolation. About 80% of infections are asymptomatic, and in 20% a mostly mild disease with fever, rash, arthralgia, and conjunctivitis may occur. Fetal infections with malformations were not recorded in Africa or Asia. Zika virus was imported to northern Brazil possibly during the world soccer championship that was hosted by Brazil in June through July 2014. A cluster of severe fetal malformations with microcephaly and ocular defects was noted in 2015 in the northeast of Brazil, and intrauterine infections with Zika virus were confirmed. The dramatic change in Zika virus pathogenicity upon its introduction to Brazil has remained an enigma.

  17. Tobacco ringspot virus

    USDA-ARS?s Scientific Manuscript database

    Tobacco ringspot virus (TRSV), and its vector, the dagger nematodes (Xiphinema americanum and related species) are widely distributed throughout the world. Cucumber, melon, and watermelon are particularly affected by TRSV. Symptoms can vary with plant age, the strain of the virus, and environment...

  18. Papaya ringspot virus (Potyviridae)

    USDA-ARS?s Scientific Manuscript database

    Papaya ringspot virus, a member of the family Potyviridae, is single stranded RNA plant virus with a monocistronic genome of about 10,326 nucleotides that is expressed via a large polyprotein subsequently cleaved into functional proteins. It causes severe damage on cucurbit crops such as squash and...

  19. Virus separation using membranes.

    PubMed

    Grein, Tanja A; Michalsky, Ronald; Czermak, Peter

    2014-01-01

    Industrial manufacturing of cell culture-derived viruses or virus-like particles for gene therapy or vaccine production are complex multistep processes. In addition to the bioreactor, such processes require a multitude of downstream unit operations for product separation, concentration, or purification. Similarly, before a biopharmaceutical product can enter the market, removal or inactivation of potential viral contamination has to be demonstrated. Given the complexity of biological solutions and the high standards on composition and purity of biopharmaceuticals, downstream processing is the bottleneck in many biotechnological production trains. Membrane-based filtration can be an economically attractive and efficient technology for virus separation. Viral clearance, for instance, of up to seven orders of magnitude has been reported for state of the art polymeric membranes under best conditions.This chapter summarizes the fundamentals of virus ultrafiltration, diafiltration, or purification with adsorptive membranes. In lieu of an impractical universally applicable protocol for virus filtration, application of these principles is demonstrated with two examples. The chapter provides detailed methods for production, concentration, purification, and removal of a rod-shaped baculovirus (Autographa californica M nucleopolyhedrovirus, about 40 × 300 nm in size, a potential vector for gene therapy, and an industrially important protein expression system) or a spherical parvovirus (minute virus of mice, 22-26 nm in size, a model virus for virus clearance validation studies).

  20. Papaya Ringspot Virus

    USDA-ARS?s Scientific Manuscript database

    The term papaya ringspot virus (PRSV) was coined by Jensen in 1949, to describe a papaya disease in Hawaii. Later work showed that diseases such as papaya mosaic and watermelon mosaic virus-1 were caused by PRSV. The primary host range of PRSV is papaya and cucurbits, with Chenopium amaranticolor ...

  1. Zika Virus and Pregnancy.

    PubMed

    Stagg, Denise; Hurst, Helen M

    2016-01-01

    Recent outbreaks of Zika virus and reports linking infection in pregnant women with microcephaly in newborns have caused concern worldwide. Information has been evolving rapidly. Nurses and other clinicians, especially those who work with women of childbearing age, play a pivotal role in disseminating accurate information and identifying potential cases of Zika virus infection.

  2. Lethal mutagenesis of viruses.

    PubMed

    Perales, Celia; Martín, Verónica; Domingo, Esteban

    2011-11-01

    Lethal mutagenesis aims at extinguishing viruses by increased mutagenesis prompted by virus-specific mutagenic agents, mainly nucleoside analogues. It is derived from the error threshold relationship of quasispecies theory, and it is slowly finding its way towards a clinical application. We summarize the current situation of research in this field of antiviral therapy. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Virus excretion in smallpox

    PubMed Central

    Sarkar, J. K.; Mitra, A. C.; Mukherjee, M. K.; De, S. K.

    1973-01-01

    Throat swabs of 34 of 328 family contacts of 52 smallpox cases, examined 4-8 days after the onset of the disease in the family, were positive for variola virus. The log titre of virus per swab ranged from 2 to 3.95. A higher proportion of unvaccinated than of vaccinated contacts excreted the virus. Only 4 of the virus-positive contacts developed clinical smallpox; this occurred 5-7 days after their swabs were examined. Excretion of virus in the throats of these contacts, a few of whom were in the incubation period of the disease, suggests the possibility that they could have spread the infection. This possibility, if kept in mind, may help in tracing the source of infection or in determining the incubation period in a few instances when difficulty is experienced. PMID:4359679

  4. Hepatitis B Virus Biology

    PubMed Central

    Seeger, Christoph; Mason, William S.

    2000-01-01

    Hepadnaviruses (hepatitis B viruses) cause transient and chronic infections of the liver. Transient infections run a course of several months, and chronic infections are often lifelong. Chronic infections can lead to liver failure with cirrhosis and hepatocellular carcinoma. The replication strategy of these viruses has been described in great detail, but virus-host interactions leading to acute and chronic disease are still poorly understood. Studies on how the virus evades the immune response to cause prolonged transient infections with high-titer viremia and lifelong infections with an ongoing inflammation of the liver are still at an early stage, and the role of the virus in liver cancer is still elusive. The state of knowledge in this very active field is therefore reviewed with an emphasis on past accomplishments as well as goals for the future. PMID:10704474

  5. Electron tomography of viruses.

    PubMed

    Subramaniam, Sriram; Bartesaghi, Alberto; Liu, Jun; Bennett, Adam E; Sougrat, Rachid

    2007-10-01

    Understanding the molecular architectures of enveloped and complex viruses is a challenging frontier in structural biology. In these viruses, the structural and compositional variation from one viral particle to another generally precludes the use of either crystallization or image averaging procedures that have been successfully implemented in the past for highly symmetric viruses. While advances in cryo electron tomography of unstained specimens provide new opportunities for identification and molecular averaging of individual subcomponents such as the surface glycoprotein spikes on purified viruses, electron tomography of stained and plunge-frozen cells is being used to visualize the cellular context of viral entry and replication. Here, we review recent developments in both areas as they relate to our understanding of the biology of heterogeneous and pleiomorphic viruses.

  6. Mayaro virus proteins.

    PubMed

    Mezencio, J M; Rebello, M A

    1993-01-01

    Mayaro virus was grown in BHK-21 cells and purified by centrifugation in a potassium-tartrate gradient (5-50%). The electron microscopy analyses of the purified virus showed an homogeneous population of enveloped particles with 69 +/- 2.3 nm in diameter. Three structural virus proteins were identified and designated p1, p2 and p3. Their average molecular weight were p1, 54 KDa; p2, 50 KDa and p3, 34 KDa. In Mayaro virus infected Aedes albopictus cells and in BHK-21 infected cells we detected six viral proteins, in which three of them are the structural virus proteins and the other three were products from processing of precursors of viral proteins, whose molecular weights are 62 KDa, 64 KDa and 110 KDa. The 34 KDa protein was the first viral protein synthesized at 5 hours post-infection in both cell lines studied.

  7. Infectious Viral Quantification of Chikungunya Virus-Virus Plaque Assay.

    PubMed

    Kaur, Parveen; Lee, Regina Ching Hua; Chu, Justin Jang Hann

    2016-01-01

    The plaque assay is an essential method for quantification of infectious virus titer. Cells infected with virus particles are overlaid with a viscous substrate. A suitable incubation period results in the formation of plaques, which can be fixed and stained for visualization. Here, we describe a method for measuring Chikungunya virus (CHIKV) titers via virus plaque assays.

  8. Virus discovery and recent insights into virus diversity in arthropods.

    PubMed

    Junglen, Sandra; Drosten, Christian

    2013-08-01

    Recent studies on virus discovery have focused mainly on mammalian and avian viruses. Arbovirology with its long tradition of ecologically oriented investigation is now catching up, with important novel insights into the diversity of arthropod-associated viruses. Recent discoveries include taxonomically outlying viruses within the families Flaviviridae, Togaviridae, and Bunyaviridae, and even novel virus families within the order Nidovirales. However, the current focusing of studies on blood-feeding arthropods has restricted the range of arthropod hosts analyzed for viruses so far. Future investigations should include species from other arthropod taxa than Ixodita, Culicidae and Phlebotominae in order to shed light on the true diversity of arthropod viruses.

  9. Virus-PEDOT Biocomposite Films

    PubMed Central

    Donavan, Keith C.; Arter, Jessica A.

    2012-01-01

    Virus-poly(3,4-ethylenedioxythiophene) (virus-PEDOT) biocomposite films are prepared by electropolymerizing 3,4-ethylenedioxythiophene (EDOT) in aqueous electrolytes containing 12 mM LiClO4 and the bacteriophage M13. The concentration of virus in these solutions, [virus]soln, is varied from 3 nM to 15 nM. A quartz crystal microbalance is used to directly measure the total mass of the biocomposite film during its electrodeposition. In combination with a measurement of the electrodeposition charge, the mass of the virus incorporated into the film is calculated. These data show that concentration of the M13 within the electropolymerized film, [virus]film, increases linearly with [virus]soln. The incorporation of virus particles into the PEDOT film from solution is efficient, resulting in a concentration ratio: [virus]film:[virus]soln ≈450. Virus incorporation into the PEDOT causes roughening of the film topography that is observed using scanning electron microscopy and atomic force microscopy (AFM). The electrical conductivity of the virus-PEDOT film, measured perpendicular to the plane of the film using conductive tip AFM, decreases linearly with virus loading, from 270 μS/cm for pure PE-DOT films to 50 μS/cm for films containing 100 μM virus. The presence on the virus surface of displayed affinity peptides did not significantly influence the efficiency of incorporation into virus-PEDOT biocomposite films. PMID:22856875

  10. Realms of the Viruses Online

    ERIC Educational Resources Information Center

    Liu, Dennis

    2007-01-01

    Viruses have evolved strategies for infecting all taxa, but most viruses are highly specific about their cellular host. In humans, viruses cause diverse diseases, from chronic but benign warts, to acute and deadly hemorrhagic fever. Viruses have entertaining names like Zucchini Yellow Mosaic, Semliki Forest, Coxsackie, and the original terminator,…

  11. Computer Viruses: Pathology and Detection.

    ERIC Educational Resources Information Center

    Maxwell, John R.; Lamon, William E.

    1992-01-01

    Explains how computer viruses were originally created, how a computer can become infected by a virus, how viruses operate, symptoms that indicate a computer is infected, how to detect and remove viruses, and how to prevent a reinfection. A sidebar lists eight antivirus resources. (four references) (LRW)

  12. A Virus in Turbo Pascal.

    ERIC Educational Resources Information Center

    Teleky, Heidi Ann; And Others

    1993-01-01

    Addresses why the authors feel it is not inappropriate to teach about viruses in the how-to, hands-on fashion. Identifies the special features of Turbo Pascal that have to be used for the creation of an effective virus. Defines virus, derives its structure, and from this structure is derived the implemented virus. (PR)

  13. A Virus in Turbo Pascal.

    ERIC Educational Resources Information Center

    Teleky, Heidi Ann; And Others

    1993-01-01

    Addresses why the authors feel it is not inappropriate to teach about viruses in the how-to, hands-on fashion. Identifies the special features of Turbo Pascal that have to be used for the creation of an effective virus. Defines virus, derives its structure, and from this structure is derived the implemented virus. (PR)

  14. Realms of the Viruses Online

    ERIC Educational Resources Information Center

    Liu, Dennis

    2007-01-01

    Viruses have evolved strategies for infecting all taxa, but most viruses are highly specific about their cellular host. In humans, viruses cause diverse diseases, from chronic but benign warts, to acute and deadly hemorrhagic fever. Viruses have entertaining names like Zucchini Yellow Mosaic, Semliki Forest, Coxsackie, and the original terminator,…

  15. Computer Viruses: Pathology and Detection.

    ERIC Educational Resources Information Center

    Maxwell, John R.; Lamon, William E.

    1992-01-01

    Explains how computer viruses were originally created, how a computer can become infected by a virus, how viruses operate, symptoms that indicate a computer is infected, how to detect and remove viruses, and how to prevent a reinfection. A sidebar lists eight antivirus resources. (four references) (LRW)

  16. ICTV virus taxonomy profile: dicistroviridae

    USDA-ARS?s Scientific Manuscript database

    Dicistroviridae is a family of small non-enveloped viruses with RNA genomes of approximately 8-10 kilobases in length. All members infect arthropod hosts with some having devastating economic consequences, such as Acute bee paralysis virus, Kashmir bee virus, and Israeli acute paralysis virus towar...

  17. Enteric hepatitis viruses

    PubMed Central

    Tahaei, Seyed Mohammad Ebrahim; Zali, Mohammad Reza

    2012-01-01

    Hepatitis viruses are infectious agents that can infect liver and cause inflammation. The infection triggers immune response against infected cells that leads to the destruction of hepatic cells. This destruction has two consequences: leaking ALT and AST liver enzymes which increases during the course of disease and accumulation of bilirubin- a red pigmented compound released from dead red cells- which causes the yellow coloration of eyes and skin. These viruses transmit through diverse routes i.e. blood transfusion, sexual contacts and consuming water or food contaminated by feces. Enteric hepatitis viruses use the latter route for transmission; hence their outbreaks are more common in underdeveloped countries. There are currently two distinguished enteric hepatitis viruses, hepatitis A and hepatitis E. These viruses belong to different family of viruses and their epidemiological characteristics are different. These infections can be diagnosed by an ELISA for IgM antibody. A vaccine has been developed in last decade of twentieth century for hepatitis A virus, which is administered mostly in the developed world i.e. U.S and Japan. Treatment for these infections is mostly supportive; however, in the case of fulminant hepatitis the liver transplantation might be necessary. PMID:24834192

  18. Respiratory RNA Viruses.

    PubMed

    Hodinka, Richard L

    2016-08-01

    Acute upper and lower respiratory infections are a major public health problem and a leading cause of morbidity and mortality worldwide. At greatest risk are young children, the elderly, the chronically ill, and those with suppressed or compromised immune systems. Viruses are the predominant cause of respiratory tract illnesses and include RNA viruses such as respiratory syncytial virus, influenza virus, parainfluenza virus, metapneumovirus, rhinovirus, and coronavirus. Laboratory testing is required for a reliable diagnosis of viral respiratory infections, as a clinical diagnosis can be difficult since signs and symptoms are often overlapping and not specific for any one virus. Recent advances in technology have resulted in the development of newer diagnostic assays that offer great promise for rapid and accurate detection of respiratory viral infections. This chapter emphasizes the fundamental characteristics and clinical importance of the various RNA viruses that cause upper and lower respiratory tract diseases in the immunocompromised host. It highlights the laboratory methods that can be used to make a rapid and definitive diagnosis for the greatest impact on the care and management of ill patients, and the prevention and control of hospital-acquired infections and community outbreaks.

  19. Enteric hepatitis viruses.

    PubMed

    Tahaei, Seyed Mohammad Ebrahim; Mohebbi, Seyed Reza; Zali, Mohammad Reza

    2012-01-01

    Hepatitis viruses are infectious agents that can infect liver and cause inflammation. The infection triggers immune response against infected cells that leads to the destruction of hepatic cells. This destruction has two consequences: leaking ALT and AST liver enzymes which increases during the course of disease and accumulation of bilirubin- a red pigmented compound released from dead red cells- which causes the yellow coloration of eyes and skin. These viruses transmit through diverse routes i.e. blood transfusion, sexual contacts and consuming water or food contaminated by feces. Enteric hepatitis viruses use the latter route for transmission; hence their outbreaks are more common in underdeveloped countries. There are currently two distinguished enteric hepatitis viruses, hepatitis A and hepatitis E. These viruses belong to different family of viruses and their epidemiological characteristics are different. These infections can be diagnosed by an ELISA for IgM antibody. A vaccine has been developed in last decade of twentieth century for hepatitis A virus, which is administered mostly in the developed world i.e. U.S and Japan. Treatment for these infections is mostly supportive; however, in the case of fulminant hepatitis the liver transplantation might be necessary.

  20. Giant viruses infecting algae.

    PubMed

    Van Etten, J L; Meints, R H

    1999-01-01

    Paramecium bursaria chlorella virus (PBCV-1) is the prototype of a family of large, icosahedral, plaque-forming, double-stranded-DNA-containing viruses that replicate in certain unicellular, eukaryotic chlorella-like green algae. DNA sequence analysis of its 330, 742-bp genome leads to the prediction that this phycodnavirus has 376 protein-encoding genes and 10 transfer RNA genes. The predicted gene products of approximately 40% of these genes resemble proteins of known function. The chlorella viruses have other features that distinguish them from most viruses, in addition to their large genome size. These features include the following: (a) The viruses encode multiple DNA methyltransferases and DNA site-specific endonucleases; (b) PBCV-1 encodes at least part, if not the entire machinery to glycosylate its proteins; (c) PBCV-1 has at least two types of introns--a self-splicing intron in a transcription factor-like gene and a splicesomal processed type of intron in its DNA polymerase gene. Unlike the chlorella viruses, large double-stranded-DNA-containing viruses that infect marine, filamentous brown algae have a circular genome and a lysogenic phase in their life cycle.

  1. Influenza virus isolation.

    PubMed

    Krauss, Scott; Walker, David; Webster, Robert G

    2012-01-01

    The isolation of influenza viruses is important for the diagnosis of respiratory diseases in lower animals and humans, for the detection of the infecting agent in surveillance programs, and is an essential element in the development and production of vaccine. Since influenza is caused by a zoonotic virus it is necessary to do surveillance in the reservoir species (aquatic waterfowls), intermediate hosts (quails, pigs), and in affected mammals including humans. Two of the hemagglutinin (HA) subtypes of influenza A viruses (H5 and H7) can evolve into highly pathogenic (HP) strains for gallinaceous poultry; some HP H5 and H7 strains cause lethal infection of humans. In waterfowls, low pathogenic avian influenza (LPAI) isolates are obtained primarily from the cloaca (or feces); in domestic poultry, the virus is more often recovered from the respiratory tract than from cloacal samples; in mammals, the virus is most often isolated from the respiratory tract, and in cases of high pathogenic avian influenza (HPAI) from the blood and internal organs of infected birds. Virus isolation procedures are performed by inoculation of clinical specimens into embryonated eggs (primarily chicken eggs) or onto a variety of primary or continuous tissue culture systems. Successful isolation of influenza virus depends on the quality of the sample and matching the appropriate culture method to the sample type.

  2. Ocular tropism of respiratory viruses.

    PubMed

    Belser, Jessica A; Rota, Paul A; Tumpey, Terrence M

    2013-03-01

    Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism.

  3. Ocular Tropism of Respiratory Viruses

    PubMed Central

    Rota, Paul A.; Tumpey, Terrence M.

    2013-01-01

    SUMMARY Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism. PMID:23471620

  4. Viruses in reptiles

    PubMed Central

    2011-01-01

    The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3.9.2. Togaviridae 3.10. Caliciviridae

  5. [Ebola virus disease].

    PubMed

    Nazimek, Katarzyna; Bociaga-Jasik, Monika; Bryniarski, Krzysztof; Gałas, Aleksander; Garlicki, Aleksander; Gawda, Anna; Gawlik, Grzegorz; Gil, Krzysztof; Kosz-Vnenchak, Magdalena; Mrozek-Budzyn, Dorota; Olszanecki, Rafał; Piatek, Anna; Zawilińska, Barbara; Marcinkiewicz, Janusz

    2014-01-01

    Ebola is one of the most virulent zoonotic RNA viruses causing in humans haemorrhagic fever with fatality ratio reaching 90%. During the outbreak of 2014 the number of deaths exceeded 8.000. The "imported" cases reported in Western Europe and USA highlighted the extreme risk of Ebola virus spreading outside the African countries. Thus, haemorrhagic fever outbreak is an international epidemiological problem, also due to the lack of approved prevention and therapeutic strategies. The editorial review article briefly summarizes current knowledge on Ebola virus disease epidemiology, etiology, pathogenesis, clinical presentation, diagnosis as well as possible prevention and treatment.

  6. Genome of Horsepox Virus

    PubMed Central

    Tulman, E. R.; Delhon, G.; Afonso, C. L.; Lu, Z.; Zsak, L.; Sandybaev, N. T.; Kerembekova, U. Z.; Zaitsev, V. L.; Kutish, G. F.; Rock, D. L.

    2006-01-01

    Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212-kbp genome contained 7.5-kbp inverted terminal repeats and lacked extensive terminal tandem repetition. HSPV contained 236 open reading frames (ORFs) with similarity to those in other OPVs, with those in the central 100-kbp region most conserved relative to other OPVs. Phylogenetic analysis of the conserved region indicated that HSPV is closely related to sequenced isolates of vaccinia virus (VACV) and rabbitpox virus, clearly grouping together these VACV-like viruses. Fifty-four HSPV ORFs likely represented fragments of 25 orthologous OPV genes, including in the central region the only known fragmented form of an OPV ribonucleotide reductase large subunit gene. In terminal genomic regions, HSPV lacked full-length homologues of genes variably fragmented in other VACV-like viruses but was unique in fragmentation of the homologue of VACV strain Copenhagen B6R, a gene intact in other known VACV-like viruses. Notably, HSPV contained in terminal genomic regions 17 kbp of OPV-like sequence absent in known VACV-like viruses, including fragments of genes intact in other OPVs and approximately 1.4 kb of sequence present only in cowpox virus (CPXV). HSPV also contained seven full-length genes fragmented or missing in other VACV-like viruses, including intact homologues of the CPXV strain GRI-90 D2L/I4R CrmB and D13L CD30-like tumor necrosis factor receptors, D3L/I3R and C1L ankyrin repeat proteins, B19R kelch-like protein, D7L BTB/POZ domain protein, and B22R variola virus B22R-like protein. These results indicated that HSPV contains unique genomic features likely contributing to a unique virulence/host range phenotype. They also indicated that while closely related to known VACV-like viruses, HSPV contains additional, potentially ancestral sequences absent in other VACV-like viruses. PMID:16940536

  7. Virus templated metallic nanoparticles.

    PubMed

    Aljabali, Alaa A A; Barclay, J Elaine; Lomonossoff, George P; Evans, David J

    2010-12-01

    Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. ≤35 nm. CPMV-templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron.

  8. Fighting cancer with viruses

    NASA Astrophysics Data System (ADS)

    Ferreira, S. C.; Martins, M. L.; Vilela, M. J.

    2005-01-01

    One of the most promising strategies to treat cancer is attacking it with viruses. Viruses can kill tumor cells specifically or act as carriers that deliver normal genes into cancer cells. A model for virotherapy of cancer is investigated and its predictions are in agreement with results obtained from experimental tumors. Furthermore, the model reveals an oscillatory (periodic or aperiodic) response of tumor cells and virus populations which may make clinical prognosis difficult. These results suggest the need for new in vivo and in vitro experiments aiming to detect this oscillatory response.

  9. Zika Virus Infection.

    PubMed

    Shirley, Debbie-Ann T; Nataro, James P

    2017-08-01

    In less than 2 years since entry into the Americas, we have witnessed the emergent spread of Zika virus into large subsets of immunologically naïve human populations and then encountered the devastating effects of microcephaly and brain anomalies that can arise from in utero infection with the virus. Diagnostic evaluation and management of affected infants continues to evolve as our understanding of Zika virus rapidly advances. The development of a safe and effective vaccine holds the potential to attenuate the spread of infection and limit the impact of congenital infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Zika virus in Asia.

    PubMed

    Duong, Veasna; Dussart, Philippe; Buchy, Philippe

    2017-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne virus that was first isolated from a sentinel rhesus monkey in the Zika Forest in Uganda in 1947. In Asia, the virus was isolated in Malaysia from Aedes aegypti mosquitoes in 1966, and the first human infections were reported in 1977 in Central Java, Indonesia. In this review, all reported cases of ZIKV infection in Asia as of September 1, 2016 are summarized and some of the hypotheses that could currently explain the apparently low incidence of Zika cases in Asia are explored.

  11. Zika virus: An overview

    PubMed Central

    Rawal, Gautam; Yadav, Sankalp; Kumar, Raj

    2016-01-01

    The Zika virus has been in the news for quite some time due to the ongoing recent outbreak in the Southern America, which started in December 2015. It has been declared a public health emergency by the World Health Organization in February 2016 owing to its association with the congenital deformities, particularly microcephaly in infants borne to the infected mothers. The rapid spread of the virus throughout the United States of America and subsequently to Asia has raised serious international concerns. Its spread to countries neighboring India is a serious threat to the Indian population. This review article gives an overview about the virus, its diagnosis, clinical features, and the management. PMID:28217576

  12. Contra Garrisonian Social Constructivism

    NASA Astrophysics Data System (ADS)

    Davson-Galle, Peter

    In a recent paper in this journal, Jim Garrison (1997) opines that a Deweyan social constructivism ought to be embraced by science educators in preference to the subjectivist variety espoused by Ernst von Glasersfeld as it ...retains all [of the latter's] virtues and does not get caught up in its confusions' (p. 543). In this response, I argue that key elements of Garrison's complaints are misguided and that his preferred Deweyan social constructivism is a theoretical framework without apparent superiority and with enough flaws that it is best eschewed by science educators (and metascientists generally).

  13. Development of high-yield influenza B virus vaccine viruses.

    PubMed

    Ping, Jihui; Lopes, Tiago J S; Neumann, Gabriele; Kawaoka, Yoshihiro

    2016-12-20

    The burden of human infections with influenza A and B viruses is substantial, and the impact of influenza B virus infections can exceed that of influenza A virus infections in some seasons. Over the past few decades, viruses of two influenza B virus lineages (Victoria and Yamagata) have circulated in humans, and both lineages are now represented in influenza vaccines, as recommended by the World Health Organization. Influenza B virus vaccines for humans have been available for more than half a century, yet no systematic efforts have been undertaken to develop high-yield candidates. Therefore, we screened virus libraries possessing random mutations in the six "internal" influenza B viral RNA segments [i.e., those not encoding the major viral antigens, hemagglutinin (HA) and neuraminidase NA)] for mutants that confer efficient replication. Candidate viruses that supported high yield in cell culture were tested with the HA and NA genes of eight different viruses of the Victoria and Yamagata lineages. We identified combinations of mutations that increased the titers of candidate vaccine viruses in mammalian cells used for human influenza vaccine virus propagation and in embryonated chicken eggs, the most common propagation system for influenza viruses. These influenza B virus vaccine backbones can be used for improved vaccine virus production.

  14. Development of high-yield influenza B virus vaccine viruses

    PubMed Central

    Ping, Jihui; Lopes, Tiago J. S.; Neumann, Gabriele; Kawaoka, Yoshihiro

    2016-01-01

    The burden of human infections with influenza A and B viruses is substantial, and the impact of influenza B virus infections can exceed that of influenza A virus infections in some seasons. Over the past few decades, viruses of two influenza B virus lineages (Victoria and Yamagata) have circulated in humans, and both lineages are now represented in influenza vaccines, as recommended by the World Health Organization. Influenza B virus vaccines for humans have been available for more than half a century, yet no systematic efforts have been undertaken to develop high-yield candidates. Therefore, we screened virus libraries possessing random mutations in the six “internal” influenza B viral RNA segments [i.e., those not encoding the major viral antigens, hemagglutinin (HA) and neuraminidase NA)] for mutants that confer efficient replication. Candidate viruses that supported high yield in cell culture were tested with the HA and NA genes of eight different viruses of the Victoria and Yamagata lineages. We identified combinations of mutations that increased the titers of candidate vaccine viruses in mammalian cells used for human influenza vaccine virus propagation and in embryonated chicken eggs, the most common propagation system for influenza viruses. These influenza B virus vaccine backbones can be used for improved vaccine virus production. PMID:27930325

  15. Temporal and spatial distribution of Ixodes pacificus and Dermacentor occidentalis (Acari: Ixodidae) and prevalence of Borrelia burgdorferi in Contra Costa County, California.

    PubMed

    Kramer, V L; Beesley, C

    1993-05-01

    The seasonal activity and spatial distribution of adult and immature Ixodes pacificus Cooley & Kohls and Dermacentor occidentalis Marx were determined along trails and on hillsides in two parks in Contra Costa County, CA. I. pacificus and D. occidentalis adults were most numerous in January and May, respectively. Adult ticks were significantly more abundant along heavily vegetated trails than on open grassy hillsides, and on the uphill versus the downhill side of trails. Five species of rodents were captured, and numbers of I. pacificus and D. occidentalis larvae per rodent were highest in May-June and July, respectively. Few nymphs were recovered either by flagging or from captured rodents. An average of 2.2 and 2.8% of the I. pacificus adults collected from the two parks were infected with the Lyme disease spirochete, Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. The greatest risk of contracting Lyme disease from adult I. pacificus in these two Contra Costa County parks is during the winter months, especially while hiking near the uphill side of trails.

  16. Simian hemorrhagic fever virus

    USDA-ARS?s Scientific Manuscript database

    This book chapter describes the taxonomic classification of Simian hemorrhagic fever virus (SHFV). Included are: host, genome, classification, morphology, physicochemical and physical properties, nucleic acid, proteins, lipids, carbohydrates, geographic range, phylogenetic properties, biological pro...

  17. How rigid are viruses

    NASA Astrophysics Data System (ADS)

    Hartschuh, R. D.; Wargacki, S. P.; Xiong, H.; Neiswinger, J.; Kisliuk, A.; Sihn, S.; Ward, V.; Vaia, R. A.; Sokolov, A. P.

    2008-08-01

    Viruses have traditionally been studied as pathogens, but in recent years they have been adapted for applications ranging from drug delivery and gene therapy to nanotechnology, photonics, and electronics. Although the structures of many viruses are known, most of their biophysical properties remain largely unexplored. Using Brillouin light scattering, we analyzed the mechanical rigidity, intervirion coupling, and vibrational eigenmodes of Wiseana iridovirus (WIV). We identified phonon modes propagating through the viral assemblies as well as the localized vibrational eigenmode of individual viruses. The measurements indicate a Young’s modulus of ˜7GPa for single virus particles and their assemblies, surprisingly high for “soft” materials. Mechanical modeling confirms that the DNA core dominates the WIV rigidity. The results also indicate a peculiar mechanical coupling during self-assembly of WIV particles.

  18. Respiratory Syncytial Virus (RSV)

    MedlinePlus

    ... common virus that infects the lungs and breathing passages. Almost all babies get it before the age ... infection that causes swelling in the smallest air passages in the lungs Pneumonia, an infection in one ...

  19. VIRUS instrument enclosures

    NASA Astrophysics Data System (ADS)

    Prochaska, T.; Allen, R.; Mondrik, N.; Rheault, J. P.; Sauseda, M.; Boster, E.; James, M.; Rodriguez-Patino, M.; Torres, G.; Ham, J.; Cook, E.; Baker, D.; DePoy, Darren L.; Marshall, Jennifer L.; Hill, G. J.; Perry, D.; Savage, R. D.; Good, J. M.; Vattiat, Brian L.

    2014-08-01

    The Visible Integral-Field Replicable Unit Spectrograph (VIRUS) instrument will be installed at the Hobby-Eberly Telescope† in the near future. The instrument will be housed in two enclosures that are mounted adjacent to the telescope, via the VIRUS Support Structure (VSS). We have designed the enclosures to support and protect the instrument, to enable servicing of the instrument, and to cool the instrument appropriately while not adversely affecting the dome environment. The system uses simple HVAC air handling techniques in conjunction with thermoelectric and standard glycol heat exchangers to provide efficient heat removal. The enclosures also provide power and data transfer to and from each VIRUS unit, liquid nitrogen cooling to the detectors, and environmental monitoring of the instrument and dome environments. In this paper, we describe the design and fabrication of the VIRUS enclosures and their subsystems.

  20. Viruses causing gastroenteritis.

    PubMed

    Wilhelmi, I; Roman, E; Sánchez-Fauquier, A

    2003-04-01

    Acute gastroenteritis is one of the most common diseases in humans worldwide. Viruses are recognized as important causes of this disease, particularly in children. Since the Norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. Rotavirus is the most common cause of severe diarrhea in children under 5 years of age. Astrovirus, calicivirus and enteric adenovirus are also important etiologic agents of acute gastroenteritis. Other viruses, such as toroviruses, coronaviruses, picobirnaviruses and pestiviruses, are increasingly being identified as causative agents of diarrhea. In recent years, the availability of diagnostic tests, mainly immunoassays or molecular biology techniques, has increased our understanding of this group of viruses. The future development of a safe and highly effective vaccine against rotavirus could prevent, at least, cases of severe diarrhea and reduce mortality from this disease.

  1. The dengue viruses.

    PubMed Central

    Henchal, E A; Putnak, J R

    1990-01-01

    Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the dengue virus (dengue-1, dengue-2, dengue-3, and dengue-4) exist, with numerous virus strains found worldwide. Molecular cloning methods have led to a greater understanding of the structure of the RNA genome and definition of virus-specific structural and nonstructural proteins. Progress towards producing safe, effective dengue virus vaccines, a goal for over 45 years, has been made. Images PMID:2224837

  2. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  3. West Nile Virus

    MedlinePlus

    ... strategies visit the MedlinePlus West Nile virus site . Credit: Credit: CDC This is an enlarged view of a ... The End of an Era Acknowledgments References Photo Credits Dr. Joseph Kinyoun: Selected Bibliography NIAID 60th Anniversary ...

  4. Sexually transmitted viruses.

    PubMed Central

    Rapp, F.

    1989-01-01

    Human viruses known to be spread by sexual contact include herpes simplex viruses (HSV), papillomaviruses (HPV), human immunodeficiency virus (HIV), hepatitis B virus, and cytomegalovirus. Infections with the first three (HSV, HPV, and HIV) have reached epidemic proportions and pose global health concerns. Most of what we know about these human pathogens has been learned only recently, owing to the advent of DNA technologies and advances in culture techniques. In fact, our awareness of one virally transmitted venereal disease, acquired immunodeficiency syndrome, dates to the early 1980s. This paper touches on various aspects of the biology, pathogenesis, clinical manifestations, and, where applicable, oncogenicity of these agents, as well as current treatments and vaccine initiatives. PMID:2549736

  5. Virus Chapter: Iflaviridae

    USDA-ARS?s Scientific Manuscript database

    The iflaviruses comprise viruses isolated from arthropod species of agricultural importance. All members of iflaviruses have a genome arrangement similar to the picornaviruses, ootyviruses, and secoviruses. However, phylogenetic analysis using the RNA-dependent RNA polymerase region showed that th...

  6. [Zika, a neurotropic virus?].

    PubMed

    Del Carpio-Orantes, Luis

    2016-01-01

    In this paper, the neurotropism potential Zika virus is discussed, by comparison with viruses both RNA and DNA are neurotropic known, also it is said that compared with the new viruses that have affected the Americas, as the chikungunya, Zika has shown great affinity by brain tissue, manifested by a high incidence of acute neurological conditions, such as Guillain-Barré syndrome, among others, as well as the reported incidence of microcephaly that is abnormally high compared with the previous incidence, which, in a stillborn subject necropsied significant alterations demonstrated in brain tissue, identifying viral material and live virus in the fetoplacental complex, and demonstrating the impact both white matter and gray matter as well as basal ganglia, corpus callosum, ventricles and spinal cord, which could explain the microcephaly that concerns him. Although not a direct cause-effect relationship is demonstrated, however current evidence supports that relationship, hoping to be supported scientifically.

  7. Respiratory Syncytial Virus

    MedlinePlus

    ... respiratory syncytial virus (RSV) using indirect immunofluorescence technique. Biology & Genetics For more than 50 years, NIAID’s commitment ... Nucleotide Polymorphism Phylogenetics & Ontology Proteomics & Protein Analysis Systems Biology Data Portals Software Applications BCBB Mobyle Interface Designer ( ...

  8. West Nile Virus

    MedlinePlus

    ... you'll be infected with West Nile virus, mosquito bites can still be an itchy nuisance. The CDC advises people to protect themselves from mosquito bites by using mosquito repellent, especially at times ...

  9. Hepatitis B virus (image)

    MedlinePlus

    Hepatitis B is also known as serum hepatitis and is spread through blood and sexual contact. It is ... population. This photograph is an electronmicroscopic image of hepatitis B virus particles. (Image courtesy of the Centers for ...

  10. Ebola virus (image)

    MedlinePlus

    Ebola is a deadly disease caused by a virus. The 2014 outbreak has occurred mainly in West Africa. Symptoms often start with fever, severe headache, muscle pain, abdominal pain, diarrhea, and vomiting. Late symptoms ...

  11. What's West Nile Virus?

    MedlinePlus

    ... is caused by a bite from an infected mosquito that's already carrying the virus, but it's important ... the risk of being bitten by an infected mosquito is greatest from July to early September. But ...

  12. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Tick-borne viruses*

    PubMed Central

    Work, Telford H.

    1963-01-01

    More than 150 arthropod-borne viruses are now recognized, and over 50 of these are known to produce human infections and disease. Among these viruses are those of the tick-borne Russian spring-summer complex, which is etiologically involved in a wide variety of human diseases of varying severity. The eight antigenically different members of this complex so far known are Russian spring-summer encephalitis, louping-ill, Central European encephalitis, Omsk haemorrhagic fever, Kyasanur Forest disease, Langat, Negishi and Powassan viruses. In his review of the problems posed by these viruses and of research on them, the author points out that, while this complex is distributed around the globe in the temperate zone of the northern hemisphere, the only serious tick-borne virus disease known in the tropics is Kyasanur Forest disease. It is probable, however, that there are other, unrecognized tick-borne viruses in the tropical areas of Asia, Africa and America of importance to human health, and that these will be brought to light as virological studies of diseases of now obscure etiology are pursued. PMID:14043753

  14. Control of cucurbit viruses.

    PubMed

    Lecoq, Hervé; Katis, Nikolaos

    2014-01-01

    More than 70 well-characterized virus species transmitted by a diversity of vectors may infect cucurbit crops worldwide. Twenty of those cause severe epidemics in major production areas, occasionally leading to complete crop failures. Cucurbit viruses' control is based on three major axes: (i) planting healthy seeds or seedlings in a clean environment, (ii) interfering with vectors activity, and (iii) using resistant cultivars. Seed disinfection and seed or seedling quality controls guarantee growers on the sanitary status of their planting material. Removal of virus or vector sources in the crop environment can significantly delay the onset of viral epidemics. Insecticide or oil application may reduce virus spread in some situations. Diverse cultural practices interfere with or prevent vector reaching the crop. Resistance can be obtained by grafting for soil-borne viruses, by cross-protection, or generally by conventional breeding or genetic engineering. The diversity of the actions that may be taken to limit virus spread in cucurbit crops and their limits will be discussed. The ultimate goal is to provide farmers with technical packages that combine these methods within an integrated disease management program and are adapted to different countries and cropping systems.

  15. [West Nile virus infection].

    PubMed

    Pérez Ruiz, Mercedes; Gámez, Sara Sanbonmatsu; Clavero, Miguel Angel Jiménez

    2011-12-01

    West Nile virus (WNV) is an arbovirus usually transmitted by mosquitoes. The main reservoirs are birds, although the virus may infect several vertebrate species, such as horses and humans. Up to 80% of human infections are asymptomatic. The most frequent clinical presentation is febrile illness, and neuroinvasive disease can occur in less than 1% of cases. Spain is considered a high-risk area for the emergence of WNV due to its climate and the passage of migratory birds from Africa (where the virus is endemic). These birds nest surrounding wetlands where populations of possible vectors for the virus are abundant. Diagnosis of human neurological infections can be made by detection of IgM in serum and/or cerebrospinal fluid samples, demonstration of a four-fold increase in IgG antibodies between acute-phase and convalescent-phase serum samples, or by detection of viral genome by reverse transcription-polymerase chain reaction (especially useful in transplant recipients). Since WNV is a biosafety level 3 agent, techniques that involve cell culture are restricted to laboratories with this level of biosafety, such as reference laboratories. The National Program for the Surveillance of WNV Encephalitis allows the detection of virus circulation among birds and vectors in areas especially favorable for the virus, such as wetlands, and provides information for evaluation of the risk of disease in horses and humans.

  16. Inactivation of rabies virus.

    PubMed

    Wu, Guanghui; Selden, David; Fooks, Anthony R; Banyard, Ashley

    2017-05-01

    Rabies virus is a notifiable pathogen that must be handled in high containment facilities where national and international guidelines apply. For the effective inactivation of rabies virus, a number of reagents were tested. Virkon S (1%) solution caused more than 4log reduction of rabies virus in culture medium supplemented with 10% foetal calf serum within 1min. Isopropyl alcohol (70%) treatment resulted in >3log reduction of rabies virus within 20s when applied at a ratio of 19:1, making it a suitable agent for surface decontamination whereas 70% ethanol was ineffective. Rabies virus (from 10(2.33) to 10(3)ffu/ml) was also inactivated when cell cultures were fixed with 3% or 4% paraformaldehyde for 30min. Regardless of inactivation procedure, when taking inactivated virus preparations out of a biological containment envelope, proof of inocuity must be demonstrated to cover any possible error/deviation from procedure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  17. Isoelectric points of viruses.

    PubMed

    Michen, B; Graule, T

    2010-08-01

    Viruses as well as other (bio-)colloids possess a pH-dependent surface charge in polar media such as water. This electrostatic charge determines the mobility of the soft particle in an electric field and thus governs its colloidal behaviour which plays a major role in virus sorption processes. The pH value at which the net surface charge switches its sign is referred to as the isoelectric point (abbreviations: pI or IEP) and is a characteristic parameter of the virion in equilibrium with its environmental water chemistry. Here, we review the IEP measurements of viruses that replicate in hosts of kingdom plantae, bacteria and animalia. IEPs of viruses are found in pH range from 1.9 to 8.4; most frequently, they are measured in a band of 3.5 < IEP < 7. However, the data appear to be scattered widely within single virus species. This discrepancy is discussed and should be considered when IEP values are used to account for virus sorption processes.

  18. Virus templated metallic nanoparticles

    NASA Astrophysics Data System (ADS)

    Aljabali, Alaa A. A.; Barclay, J. Elaine; Lomonossoff, George P.; Evans, David J.

    2010-12-01

    Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. <=35 nm. CPMV-templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron.Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. <=35 nm. CPMV-templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron. Electronic supplementary information (ESI) available: Additional experimental detail, agarose gel electrophoresis results, energy dispersive X-ray spectra, ζ-potential measurements, dynamic light scattering data, nanoparticle tracking analysis and an atomic force microscopy image of Ni-CPMV. See DOI: 10.1039/c0nr00525h

  19. Transmission of influenza A viruses.

    PubMed

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-05-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to 'novel' viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages.

  20. Transmission of Influenza A Viruses

    PubMed Central

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  1. Evolutionary ecology of virus emergence.

    PubMed

    Dennehy, John J

    2017-02-01

    The cross-species transmission of viruses into new host populations, termed virus emergence, is a significant issue in public health, agriculture, wildlife management, and related fields. Virus emergence requires overlap between host populations, alterations in virus genetics to permit infection of new hosts, and adaptation to novel hosts such that between-host transmission is sustainable, all of which are the purview of the fields of ecology and evolution. A firm understanding of the ecology of viruses and how they evolve is required for understanding how and why viruses emerge. In this paper, I address the evolutionary mechanisms of virus emergence and how they relate to virus ecology. I argue that, while virus acquisition of the ability to infect new hosts is not difficult, limited evolutionary trajectories to sustained virus between-host transmission and the combined effects of mutational meltdown, bottlenecking, demographic stochasticity, density dependence, and genetic erosion in ecological sinks limit most emergence events to dead-end spillover infections. Despite the relative rarity of pandemic emerging viruses, the potential of viruses to search evolutionary space and find means to spread epidemically and the consequences of pandemic viruses that do emerge necessitate sustained attention to virus research, surveillance, prophylaxis, and treatment. © 2016 New York Academy of Sciences.

  2. Smaller Fleas: Viruses of Microorganisms

    PubMed Central

    Hyman, Paul; Abedon, Stephen T.

    2012-01-01

    Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world's most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages), the viruses of domain Archaea (archaeal viruses), the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses), and even the viruses of other viruses (satellite viruses). In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms. PMID:24278736

  3. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Avian Swine/Variant Pandemic Other Avian Influenza A Virus Infections in Humans Language: English (US) Español ... with Avian Influenza A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses ...

  4. FAQ: General Questions about West Nile Virus

    MedlinePlus

    ... Related Links Mosquito Surveillance Software General Questions About West Nile Virus Recommend on Facebook Tweet Share Compartir ... numbers of West Nile virus cases? What is West Nile virus? West Nile virus is an arthropod- ...

  5. Mechanical inoculation of plant viruses.

    PubMed

    Hull, Roger

    2009-05-01

    This technique is for the mechanical inoculation of viruses to plants. It is used to diagnose a virus by its reactions in a variety of plant species, to test the infectivity of virus samples using local lesion hosts, and to propagate viruses. The virus preparation is rubbed onto the surface of the leaf in such a way as to break the surface cells without causing too much mechanical damage. The preparation of the virus sample, its application to the leaf, and the care of the plants before and after inoculation are described.

  6. [Zika virus infection during pregnancy].

    PubMed

    Picone, O; Vauloup-Fellous, C; D'Ortenzio, E; Huissoud, C; Carles, G; Benachi, A; Faye, A; Luton, D; Paty, M-C; Ayoubi, J-M; Yazdanpanah, Y; Mandelbrot, L; Matheron, S

    2016-05-01

    A Zika virus epidemic is currently ongoing in the Americas. This virus is linked to congenital infections with potential severe neurodevelopmental dysfunction. However, incidence of fetal infection and whether this virus is responsible of other fetal complications are still unknown. National and international public health authorities recommend caution and several prevention measures. Declaration of Zika virus infection is now mandatory in France. Given the available knowledge on Zika virus, we suggest here a review of the current recommendations for management of pregnancy in case of suspicious or infection by Zika virus in a pregnant woman.

  7. Recombinant vaccinia virus/Venezuelan equine encephalitis (VEE) virus protects mice from peripheral VEE virus challenge.

    PubMed

    Kinney, R M; Esposito, J J; Mathews, J H; Johnson, B J; Roehrig, J T; Barrett, A D; Trent, D W

    1988-12-01

    Mice immunized with recombinant vaccinia virus (VACC) expressing Venezuelan equine encephalitis (VEE) virus capsid protein and glycoproteins E1 and E2 or with attenuated VEE TC-83 virus vaccine developed VEE-specific neutralizing antibody and survived intraperitoneal challenge with virulent VEE virus strains including Trinidad donkey (subtype 1AB), P676 (subtype 1C), 3880 (subtype 1D), and Everglades (subtype 2). However, unlike immunization with TC-83 virus, immunization with the recombinant VACC/VEE virus did not protect mice from intranasal challenge with VEE Trinidad donkey virus. These results suggest that recombinant VACC/VEE virus is a vaccine candidate for equines and humans at risk of mosquito-transmitted VEE disease but not for laboratory workers at risk of accidental exposure to aerosol infection with VEE virus.

  8. Serological Survey of Arthropod-Borne Viruses,

    DTIC Science & Technology

    CULICIDAE, *COLOMBIA, SERODIAGNOSIS, ARBOVIRUSES, ARBOVIRUSES, IMMUNITY, ANTIGENS, ANTIBODIES, VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS , ARTHROPODA, EPIDEMIOLOGY, ENTOMOLOGY, POPULATION, SAINT LOUIS ENCEPHALITIS VIRUS .

  9. Virus trafficking – learning from single-virus tracking

    PubMed Central

    Brandenburg, Boerries; Zhuang, Xiaowei

    2009-01-01

    What could be a better way to study virus trafficking than ‘miniaturizing oneself’ and ‘taking a ride with the virus particle’ on its journey into the cell? Single-virus tracking in living cells potentially provides us with the means to visualize the virus journey. This approach allows us to follow the fate of individual virus particles and monitor dynamic interactions between viruses and cellular structures, revealing previously unobservable infection steps. The entry, trafficking and egress mechanisms of various animal viruses have been elucidated using this method. The combination of single-virus trafficking with systems approaches and state-of-the-art imaging technologies should prove exciting in the future. PMID:17304249

  10. Viruses, definitions and reality.

    PubMed

    Herrero-Uribe, Libia

    2011-09-01

    Viruses are known to be abundant, ubiquitous, and to play a very important role in the health and evolution of life organisms. However, most biologists have considered them as entities separate from the realm of life and acting merely as mechanical artifacts that can exchange genes between different organisms. This article reviews some definitions of life organisms to determine if viruses adjust to them, and additionally, considers new discoveries to challenge the present definition of viruses. Definitions of life organisms have been revised in order to validate how viruses fit into them. Viral factories are discussed since these mini-organelles are a good example of the complexity of viral infection, not as a mechanical usurpation of cell structures, but as a driving force leading to the reorganization and modification of cell structures by viral and cell enzymes. New discoveries such as the Mimivirus, its virophage and viruses that produce filamentous tails when outside of their host cell, have stimulated the scientific community to analyze the current definition of viruses. One way to be free for innovation is to learn from life, without rigid mental structures or tied to the past, in order to understand in an integrated view the new discoveries that will be unfolded in future research. Life processes must be looked from the complexity and trans-disciplinarity perspective that includes and accepts the temporality of the active processes of life organisms, their interdependency and interrelation among them and their environment. New insights must be found to redefine life organisms, especially viruses, which still are defined using the same concepts and knowledge of the fifties.

  11. Recombinant Vaccinia Virus: Immunization against Multiple Pathogens

    NASA Astrophysics Data System (ADS)

    Perkus, Marion E.; Piccini, Antonia; Lipinskas, Bernard R.; Paoletti, Enzo

    1985-09-01

    The coding sequences for the hepatitis B virus surface antigen, the herpes simplex virus glycoprotein D, and the influenza virus hemagglutinin were inserted into a single vaccinia virus genome. Rabbits inoculated intravenously or intradermally with this polyvalent vaccinia virus recombinant produced antibodies reactive to all three authentic foreign antigens. In addition, the feasibility of multiple rounds of vaccination with recombinant vaccinia virus was demonstrated.

  12. [Viruses in drinking water].

    PubMed

    Botzenhart, K

    2007-03-01

    Viruses in drinking water can cause infectious diseases. In the past, hepatitis A and E were the most frequently observed drinking- water-borne viral infections, but in recent years several small- and large-scale norovirus epidemics have been described, even in Europe. All virus species spread via drinking water are of fecal origin. They are regularly identified in waste water even after conventional multi-stage water treatment. The approved disinfection methods can cope with these viruses if they are not integrated in larger particles. For this reason particle separation is particularly important in water treatment. Virological tests are not reliable enough to ensure that drinking water is sufficiently virus-free. The examination of 100 mL of water for E. coli and coliform bacteria is not adequate proof either. If potentially contaminated raw water is used, consumer safety must be ensured by calculating the performance of water treatment plants on a case-by-case basis. Such a calculation takes into account the virus load of the raw water, the efficiency of the physical and chemical particle elimination steps and the effect of disinfection. Those factors which determine the effectiveness of disinfection, namely concentration and exposure time or UV radiation strength, must be adjusted according to the risk of viral infection, and calculated settings must be adhered to, even if favorable E. coli levels may make them seem excessive.

  13. Engineered plant virus resistance.

    PubMed

    Galvez, Leny C; Banerjee, Joydeep; Pinar, Hasan; Mitra, Amitava

    2014-11-01

    Virus diseases are among the key limiting factors that cause significant yield loss and continuously threaten crop production. Resistant cultivars coupled with pesticide application are commonly used to circumvent these threats. One of the limitations of the reliance on resistant cultivars is the inevitable breakdown of resistance due to the multitude of variable virus populations. Similarly, chemical applications to control virus transmitting insect vectors are costly to the farmers, cause adverse health and environmental consequences, and often result in the emergence of resistant vector strains. Thus, exploiting strategies that provide durable and broad-spectrum resistance over diverse environments are of paramount importance. The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Genetic engineering offers various options for introducing transgenic virus resistance into crop plants to provide a wide range of resistance to viral pathogens. This review examines the current strategies of developing virus resistant transgenic plants. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Human T-cell lymphotrophic virus in California's injection drug users.

    PubMed

    Trachtenberg, A I; Gaudino, J A; Hanson, C V

    1991-01-01

    Human T-cell lymphotrophic virus I (HTLV-I) and human T-cell lymphotrophic virus II (HTLV-II) are closely related retroviruses that are highly prevalent in injection drug users (IDUs). The bulk of infection in this group probably occurs with HTLV-II, with a lower prevalence of HTLV-I. HTLV-I is known to cause adult T-cell leukemia/lymphoma and tropical spastic paraparesis. HTLV-II has not been proven to cause any human pathology, but may be immunosuppressive and is almost indistinguishable serologically from HTLV-I. As with human immunodeficiency virus (HIV), infection with these viruses is likely to be lifelong and the disease may have a latent period of many years. Unlike HIV, HTLV-I and/or HTLV-II are not likely to be transmitted from mother to child prenatally, and usually require breast-feeding for vertical transmission. It is likely that HTLV-I and/or HTLV-II has been prevalent in IDUs for far longer than the HIV epidemic. HTLV-I and/or HTLV-II are relevant to the AIDS epidemic in that they may function as biologic markers of behavioral risk status for HIV infection in IDUs or their sexual partners, and they may accelerate the course of HIV infection in persons coinfected with HTLV-I and/or HTLV-II and HIV. Coinfection will be more likely as the HIV epidemic progresses. Pregnant addicts entering outpatient methadone maintenance treatment in San Francisco County or Contra Costa County during 1990 were found to have an HTLV-II prevalence of 21% (n = 24). Important issues in counseling infected methadone patients are described.

  15. Ebola (Ebola Virus Disease): Treatment

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Ebola (Ebola Virus Disease) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Ebola (Ebola Virus Disease) About Ebola Questions & Answers 2014- ...

  16. Ebola (Ebola Virus Disease): Prevention

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Ebola (Ebola Virus Disease) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Ebola (Ebola Virus Disease) About Ebola Questions & Answers 2014- ...

  17. Ebola (Ebola Virus Disease): Diagnosis

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Ebola (Ebola Virus Disease) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Ebola (Ebola Virus Disease) About Ebola Questions & Answers 2014- ...

  18. Ebola (Ebola Virus Disease): Transmission

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Ebola (Ebola Virus Disease) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Ebola (Ebola Virus Disease) About Ebola Questions & Answers 2014- ...

  19. Production of virus resistant plants

    DOEpatents

    Dougherty, W.G.; Lindbo, J.A.

    1996-12-10

    A method of suppressing virus gene expression in plants using untranslatable plus sense RNA is disclosed. The method is useful for the production of plants that are resistant to virus infection. 9 figs.

  20. Emerging issues in virus taxonomy.

    PubMed

    van Regenmortel, Marc H V; Mahy, Brian W J

    2004-01-01

    Viruses occupy a unique position in biology. Although they possess some of the properties of living systems such as having a genome, they are actually nonliving infectious entities and should not be considered microorganisms. A clear distinction should be drawn between the terms virus, virion, and virus species. Species is the most fundamental taxonomic category used in all biological classification. In 1991, the International Committee on Taxonomy of Viruses (ICTV) decided that the category of virus species should be used in virus classification together with the categories of genus and family. More than 50 ICTV study groups were given the task of demarcating the 1,550 viral species that were recognized in the 7th ICTV report, which was published in 2000. We briefly describe the changes in virus classification that were introduced in that report. We also discuss recent proposals to introduce a nonlatinized binomial nomenclature for virus species.

  1. Special Issue: Honey Bee Viruses.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2015-10-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field.

  2. Epstein-Barr virus test

    MedlinePlus

    ... medlineplus.gov/ency/article/003513.htm Epstein-Barr virus antibody test To use the sharing features on this page, please enable JavaScript. Epstein-Barr virus antibody test is a blood test to detect ...

  3. Chlorella viruses isolated in China

    SciTech Connect

    Zhang, Y.; Burbank, D.E.; Van Etten, J.L. )

    1988-09-01

    Plaque-forming viruses of the unicellular, eukaryotic, exsymbiotic, Chlorella-like green algae strain NC64A, which are common in the United States, were also present in fresh water collected in the People's Republic of China. Seven of the Chinese viruses were examined in detail and compared with the Chlorella viruses previously isolated in the United States. Like the American viruses, the Chinese viruses were large polyhedra and sensitive to chloroform. They contained numerous structural proteins and large double-stranded DNA genomes of at least 300 kilobase pairs. Each of the DNAs from the Chinese viruses contained 5-methyldeoxycytosine, which varied from 12.6 to 46.7% of the deoxycytosine, and N{sup 6}-methyldeoxyadenosine, which varied from 2.2 to 28.3% of the deoxyadenosine. Four of the Chinese virus DNAs hybridized extensively with {sup 32}P-labeled DNA from the American virus PBCV-1, and three hybridized poorly.

  4. Sialic Acid Receptors of Viruses.

    PubMed

    Matrosovich, Mikhail; Herrler, Georg; Klenk, Hans Dieter

    2015-01-01

    Sialic acid linked to glycoproteins and gangliosides is used by many viruses as a receptor for cell entry. These viruses include important human and animal pathogens, such as influenza, parainfluenza, mumps, corona, noro, rota, and DNA tumor viruses. Attachment to sialic acid is mediated by receptor binding proteins that are constituents of viral envelopes or exposed at the surface of non-enveloped viruses. Some of these viruses are also equipped with a neuraminidase or a sialyl-O-acetyl-esterase. These receptor-destroying enzymes promote virus release from infected cells and neutralize sialic acid-containing soluble proteins interfering with cell surface binding of the virus. Variations in the receptor specificity are important determinants for host range, tissue tropism, pathogenicity, and transmissibility of these viruses.

  5. Emerging Issues in Virus Taxonomy

    PubMed Central

    Mahy, Brian W.J.

    2004-01-01

    Viruses occupy a unique position in biology. Although they possess some of the properties of living systems such as having a genome, they are actually nonliving infectious entities and should not be considered microorganisms. A clear distinction should be drawn between the terms virus, virion, and virus species. Species is the most fundamental taxonomic category used in all biological classification. In 1991, the International Committee on Taxonomy of Viruses (ICTV) decided that the category of virus species should be used in virus classification together with the categories of genus and family. More than 50 ICTV study groups were given the task of demarcating the 1,550 viral species that were recognized in the 7th ICTV report, which was published in 2000. We briefly describe the changes in virus classification that were introduced in that report. We also discuss recent proposals to introduce a nonlatinized binomial nomenclature for virus species. PMID:15078590

  6. Testing for Human Immunodeficiency Virus

    MedlinePlus

    ... incisions made in the mother’s abdomen and uterus. Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the body’s immune system and causes acquired immunodeficiency syndrome (AIDS). Immune System: ...

  7. Special Issue: Honey Bee Viruses

    PubMed Central

    Gisder, Sebastian; Genersch, Elke

    2015-01-01

    Pollination of flowering plants is an important ecosystem service provided by wild insect pollinators and managed honey bees. Hence, losses and declines of pollinating insect species threaten human food security and are of major concern not only for apiculture or agriculture but for human society in general. Honey bee colony losses and bumblebee declines have attracted intensive research interest over the last decade and although the problem is far from being solved we now know that viruses are among the key players of many of these bee losses and bumblebee declines. With this special issue on bee viruses we, therefore, aimed to collect high quality original papers reflecting the current state of bee virus research. To this end, we focused on newly discovered viruses (Lake Sinai viruses, bee macula-like virus), or a so far neglected virus species (Apis mellifera filamentous virus), and cutting edge technologies (mass spectrometry, RNAi approach) applied in the field. PMID:26702462

  8. Detection of airborne polyoma virus.

    PubMed Central

    McGarrity, G. J.; Dion, A. S.

    1978-01-01

    Polyoma virus was recovered from the air of an animal laboratory housing mice infected with the virus. Air samples were obtained by means of a high volume air sampler and further concentrated by high speed centrifugation. Total concentration of the air samples was 7.5 x 10(7). Assay for polyoma virus was by mouse antibody production tests. Airborne polyoma virus was detected in four of six samples. PMID:211163

  9. Zika Virus Research Models.

    PubMed

    Kublin, Jessica L; Whitney, James B

    2017-08-12

    The 2015 Brazilian Zika virus outbreak sparked a rapid response to control the spread of the virus. What was first understood to be a mild self-resolving infection is now linked to significant neurological defects in both neonates, and adults. The WHO declared the 2016 Zika epidemic a public health emergency and issued an unprecedented recommendation to women in affected regions to delay pregnancy until the risks surrounding Zika virus could be understood, or the epidemic contained. Since that time, considerable effort has been dedicated to understanding Zika transmission and pathogenesis to aid the development of drugs and vaccines. Several models have emerged to study several facets of Zika biology; this review details the various model systems. Copyright © 2017. Published by Elsevier B.V.

  10. Virus resistance in orchids.

    PubMed

    Koh, Kah Wee; Lu, Hsiang-Chia; Chan, Ming-Tsair

    2014-11-01

    Orchid plants, Phalaenopsis and Dendrobium in particular, are commercially valuable ornamental plants sold worldwide. Unfortunately, orchid plants are highly susceptible to viral infection by Cymbidium mosaic virus (CymMV) and Odotoglossum ringspot virus (ORSV), posing a major threat and serious economic loss to the orchid industry worldwide. A major challenge is to generate an effective method to overcome plant viral infection. With the development of optimized orchid transformation biotechnological techniques and the establishment of concepts of pathogen-derived resistance (PDR), the generation of plants resistant to viral infection has been achieved. The PDR concept involves introducing genes that is(are) derived from the virus into the host plant to induce RNA- or protein-mediated resistance. We here review the fundamental mechanism of the PDR concept, and illustrate its application in protecting against viral infection of orchid plants.

  11. Usutu virus, Belgium, 2016.

    PubMed

    Garigliany, M; Linden, A; Gilliau, G; Levy, E; Sarlet, M; Franssen, M; Benzarti, E; Derouaux, A; Francis, F; Desmecht, D

    2017-03-01

    During late summer 2016, in a northwest European region extending over Belgium, the Netherlands and the eastern border of the German state of North Rhine Westphalia, an outbreak of wild bird deaths occurred similar to those reported on the continent since 1996. Dead birds were necropsied and examined by complementary methods. Pathologic and immunohistological investigations strongly suggested an infection by Usutu virus. Subsequently, genomic segments of the said virus were detected, the virus was isolated and its complete genome was sequenced. The strain, designated Usutu-LIEGE, is a close phylogenetic relative of those isolated in Germany which form a distinct group within the USUV phylogeny, the so-called Europe_3 lineage. Should this outbreak recapitulate the characteristics of those in southwest Germany in 2011 and in/around Vienna (Austria) in 2001, it is expected that specific avian populations in the affected area will face a significant reduction in size for a few years.

  12. Herpes zoster virus vaccine.

    PubMed

    Woolery, William Alan

    2008-10-01

    Varicella zoster virus (VZV) is the etiologic agent of varicella and herpes zoster (HZ) in humans. Herpes zoster is the result of reactivation of VZV within certain sensory ganglia. The burden of illness from HZ and post-herpetic neuralgia (PHN) is high. Herpes-zoster vaccine contains live attenuated varicella-zoster virus in an amount approximately 14 times greater than that found in the varicella virus vaccine. Herpes zoster vaccine is approved for the prevention of shingles in appropriate persons aged 60 and older. The vaccine is administered in a single subcutaneous dose. Reported side effects are mild and generally limited to localized injection site findings. Herpes-zoster vaccine reportedly decreases the occurrence of herpes zoster by approximately 50 percent and prevents the development of PHN by two thirds. The vaccine appears to be minimally effective in those individuals over the age of 80 and is not recommended in this age group.

  13. Viruses in water

    PubMed Central

    Melnick, Joseph L.; Gerba, Charles P.; Wallis, Craig

    1978-01-01

    Attention is drawn in this paper to the increasing problem of viral contamination of water and shellfish, particularly since growing demands for available water resources by a rising world population and expanding industry will make the recycling of wastewater almost inevitable in the future. The problem of eliminating viruses pathogenic for man from water is considered in the light of present water treatment procedures, which are often inadequate for that purpose. Man may be exposed to waterborne viruses through the consumption of contaminated water, shellfish, or crops, as a result of recreational activities involving water, or from aerosols following the spraying of crops with liquid wastes. Physical and chemical methods of eliminating viruses from water are discussed. PMID:310357

  14. Hendra virus and Nipah virus animal vaccines.

    PubMed

    Broder, Christopher C; Weir, Dawn L; Reid, Peter A

    2016-06-24

    Hendra virus (HeV) and Nipah virus (NiV) are zoonotic viruses that emerged in the mid to late 1990s causing disease outbreaks in livestock and people. HeV appeared in Queensland, Australia in 1994 causing a severe respiratory disease in horses along with a human case fatality. NiV emerged a few years later in Malaysia and Singapore in 1998-1999 causing a large outbreak of encephalitis with high mortality in people and also respiratory disease in pigs which served as amplifying hosts. The key pathological elements of HeV and NiV infection in several species of mammals, and also in people, are a severe systemic and often fatal neurologic and/or respiratory disease. In people, both HeV and NiV are also capable of causing relapsed encephalitis following recovery from an acute infection. The known reservoir hosts of HeV and NiV are several species of pteropid fruit bats. Spillovers of HeV into horses continue to occur in Australia and NiV has caused outbreaks in people in Bangladesh and India nearly annually since 2001, making HeV and NiV important transboundary biological threats. NiV in particular possesses several features that underscore its potential as a pandemic threat, including its ability to infect humans directly from natural reservoirs or indirectly from other susceptible animals, along with a capacity of limited human-to-human transmission. Several HeV and NiV animal challenge models have been developed which have facilitated an understanding of pathogenesis and allowed for the successful development of both active and passive immunization countermeasures.

  15. Hendra Virus and Nipah Virus Animal Vaccines

    PubMed Central

    Weir, Dawn L.; Reid, Peter A.

    2016-01-01

    Hendra virus (HeV) and Nipah virus (NiV) are zoonotic viruses that emerged in the mid to late 1990s causing disease outbreaks in livestock and people. HeV appeared in Queensland, Australia in 1994 causing a severe respiratory disease in horses along with a human case fatality. NiV emerged a few years later in Malaysia and Singapore in 1998-99 causing a large outbreak of encephalitis with high mortality in people and also respiratory disease in pigs which served as amplifying hosts. The key pathological elements of HeV and NiV infection in several species of mammals, and also in people, are a severe systemic and often fatal neurologic and/or respiratory disease. In people, both HeV and NiV are also capable of causing relapsed encephalitis following recovery from an acute infection. The known reservoir hosts of HeV and NiV are several species of pteropid fruit bats. Spillovers of HeV into horses continue to occur in Australia and NiV has caused outbreaks in people in Bangladesh and India nearly annually since 2001, making HeV and NiV important transboundary biological threats. NiV in particular possesses several features that underscore its potential as a pandemic threat, including its ability to infect humans directly from natural reservoirs or indirectly from other susceptible animals, along with a capacity of limited human-to-human transmission. Several HeV and NiV animal challenge models have been developed which have facilitated an understanding of pathogenesis and allowed for the successful development of both active and passive immunization countermeasures. PMID:27154393

  16. Viability of Teschen Disease Virus

    PubMed Central

    Gray, D. P.; Girard, Andre

    1963-01-01

    A portion of spinal cord taken from a pig infected with the Konratice strain of Teschen Disease virus was found to be infectious for swine after an eleven year period of storage at dry ice temperature. The virus was recovered in tissue culture from the brains of two experimentally infected pigs, titrated, and a serum-virus neutralization test performed. PMID:17649419

  17. Viability of Teschen Disease Virus.

    PubMed

    Gray, D P; Girard, A

    1963-01-01

    A portion of spinal cord taken from a pig infected with the Konratice strain of Teschen Disease virus was found to be infectious for swine after an eleven year period of storage at dry ice temperature. The virus was recovered in tissue culture from the brains of two experimentally infected pigs, titrated, and a serum-virus neutralization test performed.

  18. Protecting Your Computer from Viruses

    ERIC Educational Resources Information Center

    Descy, Don E.

    2006-01-01

    A computer virus is defined as a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer. The existence of computer viruses--or the necessity of avoiding viruses--is part of using a computer. With the advent of the Internet, the door was opened wide for these…

  19. Computer Bytes, Viruses and Vaccines.

    ERIC Educational Resources Information Center

    Palmore, Teddy B.

    1989-01-01

    Presents a history of computer viruses, explains various types of viruses and how they affect software or computer operating systems, and describes examples of specific viruses. Available vaccines are explained, and precautions for protecting programs and disks are given. (nine references) (LRW)

  20. An introduction to computer viruses

    SciTech Connect

    Brown, D.R.

    1992-03-01

    This report on computer viruses is based upon a thesis written for the Master of Science degree in Computer Science from the University of Tennessee in December 1989 by David R. Brown. This thesis is entitled An Analysis of Computer Virus Construction, Proliferation, and Control and is available through the University of Tennessee Library. This paper contains an overview of the computer virus arena that can help the reader to evaluate the threat that computer viruses pose. The extent of this threat can only be determined by evaluating many different factors. These factors include the relative ease with which a computer virus can be written, the motivation involved in writing a computer virus, the damage and overhead incurred by infected systems, and the legal implications of computer viruses, among others. Based upon the research, the development of a computer virus seems to require more persistence than technical expertise. This is a frightening proclamation to the computing community. The education of computer professionals to the dangers that viruses pose to the welfare of the computing industry as a whole is stressed as a means of inhibiting the current proliferation of computer virus programs. Recommendations are made to assist computer users in preventing infection by computer viruses. These recommendations support solid general computer security practices as a means of combating computer viruses.

  1. Detection of Lassa virus, Mali.

    PubMed

    Safronetz, David; Lopez, Job E; Sogoba, Nafomon; Traore', Sékou F; Raffel, Sandra J; Fischer, Elizabeth R; Ebihara, Hideki; Branco, Luis; Garry, Robert F; Schwan, Tom G; Feldmann, Heinz

    2010-07-01

    To determine whether Lassa virus was circulating in southern Mali, we tested samples from small mammals from 3 villages, including Soromba, where in 2009 a British citizen probably contracted a lethal Lassa virus infection. We report the isolation and genetic characterization of Lassa virus from an area previously unknown for Lassa fever.

  2. Mosquitoborne Viruses, Czech Republic, 2002

    PubMed Central

    Zeman, Petr; Halouzka, Jiří; Juřicová, Zina; Šťovíčková, Eva; Bálková, Helena; Šikutová, Silvie; Rudolf, Ivo

    2005-01-01

    Specimens from residents (n = 497) of an area affected by the 2002 flood were examined serologically for mosquitoborne viruses. Antibodies were detected against Tahyna (16%), Sindbis (1%), and Batai (0.2%) viruses, but not West Nile virus. An examination of paired serum samples showed 1 Tahyna bunyavirus (California group) infection. PMID:15705333

  3. Protecting Your Computer from Viruses

    ERIC Educational Resources Information Center

    Descy, Don E.

    2006-01-01

    A computer virus is defined as a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer. The existence of computer viruses--or the necessity of avoiding viruses--is part of using a computer. With the advent of the Internet, the door was opened wide for these…

  4. Nematode-borne plant viruses

    USDA-ARS?s Scientific Manuscript database

    There are 30 plant-parasitic nematode species that are known to transmit 14 plant viruses. Nematode-transmitted viruses affect a range of agriculturally important crops including grape, cherry, potato, and tomato. The nematodes that transmit viruses are found in two families, Longidoridae and Tric...

  5. Computer Bytes, Viruses and Vaccines.

    ERIC Educational Resources Information Center

    Palmore, Teddy B.

    1989-01-01

    Presents a history of computer viruses, explains various types of viruses and how they affect software or computer operating systems, and describes examples of specific viruses. Available vaccines are explained, and precautions for protecting programs and disks are given. (nine references) (LRW)

  6. Ipomoviruses: Squash vein yellowing virus, Cucumber vein yellowing virus, Cassava brown streak virus, and Ugandan cassava brown streak virus

    USDA-ARS?s Scientific Manuscript database

    Ipomoviruses including Squash vein yellowing virus, Cucumber vein yellowing virus and Cassava brown streak virus are currently causing significant economic impact on crop production in several regions of the world. Only recently have results of detailed characterization of their whitefly transmissi...

  7. Avian influenza virus RNA extraction

    USDA-ARS?s Scientific Manuscript database

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  8. An introduction to computer viruses

    SciTech Connect

    Brown, D.R.

    1992-03-01

    This report on computer viruses is based upon a thesis written for the Master of Science degree in Computer Science from the University of Tennessee in December 1989 by David R. Brown. This thesis is entitled An Analysis of Computer Virus Construction, Proliferation, and Control and is available through the University of Tennessee Library. This paper contains an overview of the computer virus arena that can help the reader to evaluate the threat that computer viruses pose. The extent of this threat can only be determined by evaluating many different factors. These factors include the relative ease with which a computer virus can be written, the motivation involved in writing a computer virus, the damage and overhead incurred by infected systems, and the legal implications of computer viruses, among others. Based upon the research, the development of a computer virus seems to require more persistence than technical expertise. This is a frightening proclamation to the computing community. The education of computer professionals to the dangers that viruses pose to the welfare of the computing industry as a whole is stressed as a means of inhibiting the current proliferation of computer virus programs. Recommendations are made to assist computer users in preventing infection by computer viruses. These recommendations support solid general computer security practices as a means of combating computer viruses.

  9. Viruses as living processes.

    PubMed

    Dupré, John; Guttinger, Stephan

    2016-10-01

    The view that life is composed of distinct entities with well-defined boundaries has been undermined in recent years by the realisation of the near omnipresence of symbiosis. What had seemed to be intrinsically stable entities have turned out to be systems stabilised only by the interactions between a complex set of underlying processes (Dupré, 2012). This has not only presented severe problems for our traditional understanding of biological individuality but has also led some to claim that we need to switch to a process ontology to be able adequately to understand biological systems. A large group of biological entities, however, has been excluded from these discussions, namely viruses. Viruses are usually portrayed as stable and distinct individuals that do not fit the more integrated and collaborative picture of nature implied by symbiosis. In this paper we will contest this view. We will first discuss recent findings in virology that show that viruses can be 'nice' and collaborate with their hosts, meaning that they form part of integrated biological systems and processes. We further offer various reasons why viruses should be seen as processes rather than things, or substances. Based on these two claims we will argue that, far from serving as a counterexample to it, viruses actually enable a deeper understanding of the fundamentally interconnected and collaborative nature of nature. We conclude with some reflections on the debate as to whether viruses should be seen as living, and argue that there are good reasons for an affirmative answer to this question. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Ecology of prokaryotic viruses.

    PubMed

    Weinbauer, Markus G

    2004-05-01

    The finding that total viral abundance is higher than total prokaryotic abundance and that a significant fraction of the prokaryotic community is infected with phages in aquatic systems has stimulated research on the ecology of prokaryotic viruses and their role in ecosystems. This review treats the ecology of prokaryotic viruses ('phages') in marine, freshwater and soil systems from a 'virus point of view'. The abundance of viruses varies strongly in different environments and is related to bacterial abundance or activity suggesting that the majority of the viruses found in the environment are typically phages. Data on phage diversity are sparse but indicate that phages are extremely diverse in natural systems. Lytic phages are predators of prokaryotes, whereas lysogenic and chronic infections represent a parasitic interaction. Some forms of lysogeny might be described best as mutualism. The little existing ecological data on phage populations indicate a large variety of environmental niches and survival strategies. The host cell is the main resource for phages and the resource quality, i.e., the metabolic state of the host cell, is a critical factor in all steps of the phage life cycle. Virus-induced mortality of prokaryotes varies strongly on a temporal and spatial scale and shows that phages can be important predators of bacterioplankton. This mortality and the release of cell lysis products into the environment can strongly influence microbial food web processes and biogeochemical cycles. Phages can also affect host diversity, e.g., by 'killing the winner' and keeping in check competitively dominant species or populations. Moreover, they mediate gene transfer between prokaryotes, but this remains largely unknown in the environment. Genomics or proteomics are providing us now with powerful tools in phage ecology, but final testing will have to be performed in the environment.

  11. Map showing recent (1997-98 El Nino) and historical landslides, Crow Creek and vicinity, Alameda and Contra Costa Counties, California

    USGS Publications Warehouse

    Coe, Jeffrey A.; Godt, Jonathan; Tachker, Pierre

    2004-01-01

    This report documents the spatial distribution of 3,800 landslides caused by 1997-98 El Ni?o winter rainfall in the vicinity of Crow Creek in Alameda and Contra Costa Counties, California. The report also documents 558 historical (pre-1997-98) landslides. Landslides were mapped from 1:12,000-scale aerial photographs and classified as either debris flows or slides. Slides include rotational and translational slides, earth flows, and complex slope movements. Debris flows and slides from the 1997-98 winter modified 1 percent of the surface of the 148.6 km2 study area. Debris flows were scattered throughout the area, regardless of the type of underlying bedrock geology. Slides, however, were concentrated in a soft sandstone, conglomerate, and clayey group of rock units. Digital map files accompany the report.

  12. Cancer incidence and community exposure to air emissions from petroleum and chemical plants in Contra Costa County, California: A critical epidemiological assessment

    SciTech Connect

    Otto Wong ); Bailey, W.J.

    1993-12-01

    The northern part of Contra Costa County, California is heavily industrialized with a number of petroleum refineries, chemical facilities and other small industrial plants. Several epidemiological studies have been conducted in the country to assess cancer risk in relation to estimated air pollution levels. In this paper, the air monitoring data, air pollution modeling and the epidemiologic studies are critically reviewed. The association between cancer risk and estimated emissions is critically evaluated. The role of occupational and lifestyle (such as cigarette smoking and diet) confounding exposures is also assessed. The importance of validating exposure data generated by air pollution models in epidemiologic studies is emphasized. Pollutants of major concern are sulfur dioxide, nitrogen oxides, and hydrocarbons.

  13. Zika virus: Indian perspectives

    PubMed Central

    Mourya, Devendra T.; Shil, Pratip; Sapkal, Gajanan N.; Yadav, Pragya D.

    2016-01-01

    The emergence of Zika virus (ZiV), a mosquito borne Flavivirus like dengue (DEN) and chikungunya (CHIK), in Brazil in 2014 and its spread to various countries have led to a global health emergency. Aedes aegypti is the major vector for ZiV. Fast dissemination of this virus in different geographical areas posses a major threat especially to regions where the population lacks herd immunity against the ZiV and there is abundance of Aedes mosquitoes. In this review, we focus on current global scenario, epidemiology, biology, diagnostic challenges and remedial measures for ZiVconsidering the Indian perspective. PMID:27487998

  14. Epidemiology of Zika Virus.

    PubMed

    Younger, David S

    2016-11-01

    Zika virus is an arbovirus belonging to the Flaviviridae family known to cause mild clinical symptoms similar to those of dengue and chikungunya. Zika is transmitted by different species of Aedes mosquitoes. Nonhuman primates and possibly rodents play a role as reservoirs. Direct interhuman transmission has also been reported. Human cases have been reported in Africa and Asia, Easter Island, the insular Pacific region, and Brazil. Its clinical profile is that of a dengue-like febrile illness, but recently associated Guillain-Barre syndrome and microcephaly have appeared. There is neither a vaccine nor prophylactic medications available to prevent Zika virus infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Update on Zika Virus

    PubMed Central

    Toresdahl, Brett G.; Asif, Irfan M.

    2016-01-01

    As public health experts work to contain the outbreak of Zika virus in South America and minimize the devastating prenatal complications, the international sports community prepares for the 2016 Summer Olympic and Paralympic Games in Rio de Janeiro, Brazil. Athletes have publicly expressed concern regarding the health risks of competition in Zika-endemic areas.33 Ensuring the safety of the athletes during training and competition is the primary role of the team physician. Special consideration is needed for sports teams preparing for travel to areas affected by Zika virus. PMID:27436751

  16. Viruses and viral proteins.

    PubMed

    Verdaguer, Nuria; Ferrero, Diego; Murthy, Mathur R N

    2014-11-01

    For more than 30 years X-ray crystallography has been by far the most powerful approach for determining the structures of viruses and viral proteins at atomic resolution. The information provided by these structures, which covers many important aspects of the viral life cycle such as cell-receptor recognition, viral entry, nucleic acid transfer and genome replication, has extensively enriched our vision of the virus world. Many of the structures available correspond to potential targets for antiviral drugs against important human pathogens. This article provides an overview of the current knowledge of different structural aspects of the above-mentioned processes.

  17. Herpes Virus Amplicon Vectors

    PubMed Central

    de Silva, Suresh; Bowers, William J.

    2009-01-01

    Since its emergence onto the gene therapy scene nearly 25 years ago, the replication-defective Herpes Simplex Virus Type-1 (HSV-1) amplicon has gained significance as a versatile gene transfer platform due to its extensive transgene capacity, widespread cellular tropism, minimal immunogenicity, and its amenability to genetic manipulation. Herein, we detail the recent advances made with respect to the design of the HSV amplicon, its numerous in vitro and in vivo applications, and the current impediments this virus-based gene transfer platform faces as it navigates a challenging path towards future clinical testing. PMID:19956558

  18. Zika virus outside Africa.

    PubMed

    Hayes, Edward B

    2009-09-01

    Zika virus (ZIKV) is a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis viruses. In 2007 ZIKV caused an outbreak of relatively mild disease characterized by rash, arthralgia, and conjunctivitis on Yap Island in the southwestern Pacific Ocean. This was the first time that ZIKV was detected outside of Africa and Asia. The history, transmission dynamics, virology, and clinical manifestations of ZIKV disease are discussed, along with the possibility for diagnostic confusion between ZIKV illness and dengue.The emergence of ZIKV outside of its previously known geographic range should prompt awareness of the potential for ZIKV to spread to other Pacific islands and the Americas.

  19. Viruses and viral proteins

    PubMed Central

    Verdaguer, Nuria; Ferrero, Diego; Murthy, Mathur R. N.

    2014-01-01

    For more than 30 years X-ray crystallography has been by far the most powerful approach for determining the structures of viruses and viral proteins at atomic resolution. The information provided by these structures, which covers many important aspects of the viral life cycle such as cell-receptor recognition, viral entry, nucleic acid transfer and genome replication, has extensively enriched our vision of the virus world. Many of the structures available correspond to potential targets for antiviral drugs against important human pathogens. This article provides an overview of the current knowledge of different structural aspects of the above-mentioned processes. PMID:25485129

  20. [ZIKA--VIRUS INFECTION].

    PubMed

    Velev, V

    2016-01-01

    This review summarizes the knowledge of the scientific community for Zika-virus infection. It became popular because of severe congenital damage causes of CNS in newborns whose mothers are infected during pregnancy, as well as the risk of pandemic distribution. Discusses the peculiarities of the biology and ecology of vectors--blood-sucking mosquitoes Aedes; stages in the spread of infection and practical problems which caused during pregnancy. Attention is paid to the recommendations that allow leading national and international medical organizations to deal with the threat Zika-virus infection.

  1. Virus diseases of fish

    USGS Publications Warehouse

    Watson, Stanley W.

    1954-01-01

    The degenerative or non-neoplastic diseases of possible virus origin give the fish-culturist the most concern because of the severe mortalities resulting from infection. Epizootics of this nature have been reported in carp (Cyprinus carpio) and rainbow trout (Salmo gairdneri) in Europe, in acara (Geophagus brasiliensis) in South America, in kokanee, (Oncorhynchus nerka kennerlyi) and in sockeye salmon (Oncorhynchus nerka nerka) in the State of Washington. It has been demonstrated that each epizootic was caused by an infectious filterable agent, probably a virus.

  2. Zika virus: Indian perspectives.

    PubMed

    Mourya, Devendra T; Shil, Pratip; Sapkal, Gajanan N; Yadav, Pragya D

    2016-05-01

    The emergence of Zika virus (ZiV), a mosquito borne Flavivirus like dengue (DEN) and chikungunya (CHIK), in Brazil in 2014 and its spread to various countries have led to a global health emergency. Aedes aegypti is the major vector for ZiV. Fast dissemination of this virus in different geographical areas posses a major threat especially to regions where the population lacks herd immunity against the ZiV and there is abundance of Aedes mosquitoes. In this review, we focus on current global scenario, epidemiology, biology, diagnostic challenges and remedial measures for ZiVconsidering the Indian perspective.

  3. Research on computer virus database management system

    NASA Astrophysics Data System (ADS)

    Qi, Guoquan

    2011-12-01

    The growing proliferation of computer viruses becomes the lethal threat and research focus of the security of network information. While new virus is emerging, the number of viruses is growing, virus classification increasing complex. Virus naming because of agencies' capture time differences can not be unified. Although each agency has its own virus database, the communication between each other lacks, or virus information is incomplete, or a small number of sample information. This paper introduces the current construction status of the virus database at home and abroad, analyzes how to standardize and complete description of virus characteristics, and then gives the information integrity, storage security and manageable computer virus database design scheme.

  4. Feasibility study of entrance and exit dose measurements at the contra lateral breast with alanine/electron spin resonance dosimetry in volumetric modulated radiotherapy of breast cancer

    NASA Astrophysics Data System (ADS)

    Wagner, Daniela M.; Hüttenrauch, Petra; Anton, Mathias; von Voigts-Rhetz, Philip; Zink, Klemens; Wolff, Hendrik A.

    2017-07-01

    The Physikalisch-Technische Bundesanstalt has established a secondary standard measurement system for the dose to water, D W, based on alanine/ESR (Anton et al 2013 Phys. Med. Biol. 58 3259-82). The aim of this study was to test the established measurement system for the out-of-field measurements of inpatients with breast cancer. A set of five alanine pellets were affixed to the skin of each patient at the contra lateral breast beginning at the sternum and extending over the mammilla to the distal surface. During 28 fractions with 2.2 Gy per fraction, the accumulated dose was measured in four patients. A cone beam computer tomography (CBCT) scan was generated for setup purposes before every treatment. The reference CT dataset was registered rigidly and deformably to the CBCT dataset for 28 fractions. To take the actual alanine pellet position into account, the dose distribution was calculated for every fraction using the Acuros XB algorithm. The results of the ESR measurements were compared to the calculated doses. The maximum dose measured at the sternum was 19.9 Gy  ±  0.4 Gy, decreasing to 6.8 Gy  ±  0.2 Gy at the mammilla and 4.5 Gy  ±  0.1 Gy at the distal surface of the contra lateral breast. The absolute differences between the calculated and measured doses ranged from  -1.9 Gy to 0.9 Gy. No systematic error could be seen. It was possible to achieve a combined standard uncertainty of 1.63% for D W  =  5 Gy for the measured dose. The alanine/ESR method is feasible for in vivo measurements.

  5. Junín Virus Pathogenesis and Virus Replication

    PubMed Central

    Grant, Ashley; Seregin, Alexey; Huang, Cheng; Kolokoltsova, Olga; Brasier, Allan; Peters, Clarence; Paessler, Slobodan

    2012-01-01

    Junín virus, the etiological agent of Argentine hemorrhagic fever, causes significant morbidity and mortality. The virus is spread through the aerosolization of host rodent excreta and endemic to the humid pampas of Argentina. Recently, significant progress has been achieved with the development of new technologies (e.g. reverse genetics) that have expanded knowledge about the pathogenesis and viral replication of Junín virus. We will review the pathogenesis of Junín virus in various animal models and the role of innate and adaptive immunity during infection. We will highlight current research regarding the role of molecular biology of Junín virus in elucidating virus attenuation. We will also summarize current knowledge on Junín virus pathogenesis focusing on the recent development of vaccines and potential therapeutics. PMID:23202466

  6. ICTV Virus Taxonomy Profile: Flaviviridae.

    PubMed

    Simmonds, Peter; Becher, Paul; Bukh, Jens; Gould, Ernest A; Meyers, Gregor; Monath, Tom; Muerhoff, Scott; Pletnev, Alexander; Rico-Hesse, Rebecca; Smith, Donald B; Stapleton, Jack T; Ictv Report Consortium

    2017-01-01

    The Flaviviridae is a family of small enveloped viruses with RNA genomes of 9000-13 000 bases. Most infect mammals and birds. Many flaviviruses are host-specific and pathogenic, such as hepatitis C virus in the genus Hepacivirus. The majority of known members in the genus Flavivirus are arthropod borne, and many are important human and veterinary pathogens (e.g. yellow fever virus, dengue virus). This is a summary of the current International Committee on Taxonomy of Viruses (ICTV) report on the taxonomy of the Flaviviridae, which is available at www.ictv.global/report/flaviviridae.

  7. The games plant viruses play.

    PubMed

    Elena, Santiago F; Bernet, Guillermo P; Carrasco, José L

    2014-10-01

    Mixed virus infections in plants are common in nature. The outcome of such virus-virus interactions ranges from cooperation and coexistence (synergism) to mutual exclusion (antagonism). A priori, the outcome of mixed infections is hard to predict. To date, the analyses of plant virus mixed infections were limited to reports of emerging symptoms and/or to qualitative, at best quantitative, descriptions of the accumulation of both viruses. Here, we show that evolutionary game theory provides an adequate theoretical framework to analyze mixed viral infections and to predict the long-term evolution of the mixed populations. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Influenza viruses: transmission between species.

    PubMed

    Webster, R G; Hinshaw, V S; Bean, W J; Sriram, G

    1980-02-25

    The only direct evidence for transmission of influenza viruses between species comes from studies on swine influenza viruses. Antigenically and genetically identical Hsw1N1 influenza viruses were isolated from pigs and man on the same farm in Wisconsin, U.S.A. The isolation of H3N2 influenza viruses from a wide range of lower animals and birds suggests that influenza viruses of man can spread to the lower orders. Under some conditions the H3N2 viruses can persist for a number of years in some species. The isolation, from aquatic birds, of a large number of influenza A viruses that possess surface proteins antigenically similar to the viruses isolated from man, pigs and horses provides indirect evidence for inter-species transmission. There is now a considerable body of evidence which suggests that influenza viruses of lower animals and birds may play a role in the origin of some of the pandemic strains of influenza A viruses. There is no direct evidence that the influenza viruses in aquatic birds are transmitted to man, but they may serve as a genetic pool from which some genes may be introduced into humans by recombination. Preliminary evidence suggests that the molecular basis of host range and virulence may be related to the RNA segments coding for one of the polymerase proteins (P3) and for the nucleoprotein (NP).

  9. Varicella zoster virus infection

    PubMed Central

    Gershon, Anne A.; Breuer, Judith; Cohen, Jeffrey I.; Cohrs, Randall J.; Gershon, Michael D.; Gilden, Don; Grose, Charles; Hambleton, Sophie; Kennedy, Peter G. E.; Oxman, Michael N.; Seward, Jane F.; Yamanishi, Koichi

    2017-01-01

    Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death — a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14×VI1 PMID:27188665

  10. From Shakespeare to Viruses

    SciTech Connect

    Kim, Sung-Hou

    2009-01-01

    Berkeley Lab scientists have created a unique new tool for analyzing and comparing long sets of data, be it the genomes of mammals or viruses, or the works of Shakespeare. The results of the Shakespeare analysis surprised scholars with their accuracy.

  11. Cucurbit chlorotic yellows virus

    USDA-ARS?s Scientific Manuscript database

    Cucurbit chlorotic yellows virus (CCYV) emerged as a threat to cucurbit production in Japan during the early 2000s and has since spread to China and Taiwan, as well as to the Middle East, and parts of Africa. CCYV (genus Crinivirus, family Closteroviridae) causes chlorotic mottle symptoms, intervein...

  12. Viruses: sophisticated biological machines.

    PubMed

    Rossmann, Michael G; Rao, Venigalla B

    2012-01-01

    Virus infection involves coordination of a series of molecular machines, including entry machines, replication machines, assembly machines, and genome packaging machines, leading to the production of infectious virions. This chapter provides an introduction to various viral molecular machines described in this book.

  13. Varicella zoster virus infection.

    PubMed

    Gershon, Anne A; Breuer, Judith; Cohen, Jeffrey I; Cohrs, Randall J; Gershon, Michael D; Gilden, Don; Grose, Charles; Hambleton, Sophie; Kennedy, Peter G E; Oxman, Michael N; Seward, Jane F; Yamanishi, Koichi

    2015-07-02

    Infection with varicella zoster virus (VZV) causes varicella (chickenpox), which can be severe in immunocompromised individuals, infants and adults. Primary infection is followed by latency in ganglionic neurons. During this period, no virus particles are produced and no obvious neuronal damage occurs. Reactivation of the virus leads to virus replication, which causes zoster (shingles) in tissues innervated by the involved neurons, inflammation and cell death - a process that can lead to persistent radicular pain (postherpetic neuralgia). The pathogenesis of postherpetic neuralgia is unknown and it is difficult to treat. Furthermore, other zoster complications can develop, including myelitis, cranial nerve palsies, meningitis, stroke (vasculopathy), retinitis, and gastroenterological infections such as ulcers, pancreatitis and hepatitis. VZV is the only human herpesvirus for which highly effective vaccines are available. After varicella or vaccination, both wild-type and vaccine-type VZV establish latency, and long-term immunity to varicella develops. However, immunity does not protect against reactivation. Thus, two vaccines are used: one to prevent varicella and one to prevent zoster. In this Primer we discuss the pathogenesis, diagnosis, treatment, and prevention of VZV infections, with an emphasis on the molecular events that regulate these diseases. For an illustrated summary of this Primer, visit: http://go.nature.com/14xVI1.

  14. Blueberry shock virus

    USDA-ARS?s Scientific Manuscript database

    Blueberry shock disease first observed in Washington state in 1987 and initially confused with blueberry scorch caused by Blueberry scorch virus (BlScV). However, shock affected plants produced a second flush of leaves after flowering and the plants appeared normal by late summer except for the lac...

  15. Turnip Yellow Mosaic Virus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The bumpy exterior of the turnip yellow mosaic virus (TYMV) protein coat, or capsid, was defined in detail by Dr. Alexander McPherson of the University of California, Irvin using proteins crystallized in space for analysis on Earth. TYMV is an icosahedral virus constructed from 180 copies of the same protein arranged into 12 clusters of five proteins (pentamers), and 20 clusters of six proteins (hexamers). The final TYMV structure led to the unexpected hypothesis that the virus releases its RNA by essentially chemical-mechanical means. Most viruses have fairly flat coats, but in TYNV, the fold in each protein, called the jellyroll, is clustered at the points where the protein pentamers and hexamers join. The jellyrolls are almost standing on end, producing a bumpy surface with knobs at all of the pentamers and hexamers. At the inside surface of the pentamers is a void that is not present at the hexamers. The coating had been seen in early stuties of TYMV, but McPherson's atomic structure shows much more detail. The inside surface is strikingly, and unexpectedly, different than the outside. While the pentamers contain a central void on the inside, the hexameric units contain peptides linked to each other, forming a ring or, more accurately, rings to fill the void. Credit: Dr. Alexander McPherson, University of California, Irvine

  16. Human viruses and cancer.

    PubMed

    Morales-Sánchez, Abigail; Fuentes-Pananá, Ezequiel M

    2014-10-23

    The first human tumor virus was discovered in the middle of the last century by Anthony Epstein, Bert Achong and Yvonne Barr in African pediatric patients with Burkitt's lymphoma. To date, seven viruses -EBV, KSHV, high-risk HPV, MCPV, HBV, HCV and HTLV1- have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all cancer cases worldwide. Viral oncogenic mechanisms generally include: generation of genomic instability, increase in the rate of cell proliferation, resistance to apoptosis, alterations in DNA repair mechanisms and cell polarity changes, which often coexist with evasion mechanisms of the antiviral immune response. Viral agents also indirectly contribute to the development of cancer mainly through immunosuppression or chronic inflammation, but also through chronic antigenic stimulation. There is also evidence that viruses can modulate the malignant properties of an established tumor. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers.

  17. From Shakespeare to Viruses

    SciTech Connect

    Sung-Hou Kim

    2009-02-09

    Berkeley Lab scientists have created a unique new tool for analyzing and comparing long sets of data, be it the genomes of mammals or viruses, or the works of Shakespeare. The results of the Shakespeare analysis surprised scholars with their accuracy

  18. Cold Facts about Viruses.

    ERIC Educational Resources Information Center

    Pea, Celeste; Sterling, Donna R.

    2002-01-01

    Provides ways for students to demonstrate their understanding of scientific concepts and skills. Describes a mini-unit around the cold in which students can relate humans to viruses. Includes activities and a modified simulation that provides questions to guide students. Discusses ways that allows students to apply prior knowledge, take ownership…

  19. The FEFM Virus.

    ERIC Educational Resources Information Center

    Cjelli, Dirk

    1994-01-01

    Discussion of human performance technology (HPT) interventions focuses on requests for solutions to problems that involve conflict between the FEFM ("Fix 'em for me") Virus and the WIIFM ("What's in it for me?") Requirement. Building a relationship of mutual trust and confidence with the client and demonstrating responsiveness…

  20. Virus Chapter: Dicistrovidae

    USDA-ARS?s Scientific Manuscript database

    The Dicistroviridae family comprises viruses infecting both beneficial arthropods such as honey bees and shrimp and insect pests of medical and agricultural importance. During the last five years, advances in sequencing and phylogenetic analysis have led to the discovery and identification of sever...

  1. Cucumber leaf spot virus

    USDA-ARS?s Scientific Manuscript database

    Cucumber leaf spot virus (CLSV) was originally identified from cucumber (Cucumis sativus) in Germany, but has since been found in various parts of Europe, the UK, and the Middle East, including Jordan, Saudi Arabia, Bulgaria, Poland, and Spain. CLSV is known to cause symptoms ranging from chloroti...

  2. Squash vein yellowing virus

    USDA-ARS?s Scientific Manuscript database

    Cucurbits are an important crop of temperate, subtropical and tropical regions of the world. Squash vein yellowing virus (SqVYV) is a major viral pathogen of cucurbits. This chapter provides an overview of the biology of SqVYV and the disease it causes....

  3. Cucumber vein yellowing virus

    USDA-ARS?s Scientific Manuscript database

    Cucurbits are an important crop of temperate, subtropical and tropical regions of the world. Cucumber vein yellowing virus (CVYV) is a major viral pathogen of cucurbits. This chapter provides an overview of the biology of CVYV and the disease it causes....

  4. Apple mosaic virus

    USDA-ARS?s Scientific Manuscript database

    Apple mosaic virus (ApMV), a member of the ilarvirus group, naturally infects Betula, Aesculus, Humulus, and several crop genera in the family Rosaceae (Malus, Prunus, Rosa and Rubus). ApMV was first reported in Rubus in several blackberry and raspberry cultivars in the United States and subsequentl...

  5. From Shakespeare to Viruses

    ScienceCinema

    Sung-Hou Kim

    2016-07-12

    Berkeley Lab scientists have created a unique new tool for analyzing and comparing long sets of data, be it the genomes of mammals or viruses, or the works of Shakespeare. The results of the Shakespeare analysis surprised scholars with their accuracy

  6. From Shakespeare to Viruses

    ScienceCinema

    Kim, Sung-Hou

    2016-07-12

    Berkeley Lab scientists have created a unique new tool for analyzing and comparing long sets of data, be it the genomes of mammals or viruses, or the works of Shakespeare. The results of the Shakespeare analysis surprised scholars with their accuracy.

  7. Cold Facts about Viruses.

    ERIC Educational Resources Information Center

    Pea, Celeste; Sterling, Donna R.

    2002-01-01

    Provides ways for students to demonstrate their understanding of scientific concepts and skills. Describes a mini-unit around the cold in which students can relate humans to viruses. Includes activities and a modified simulation that provides questions to guide students. Discusses ways that allows students to apply prior knowledge, take ownership…

  8. Human Viruses and Cancer

    PubMed Central

    Morales-Sánchez, Abigail; Fuentes-Pananá, Ezequiel M.

    2014-01-01

    The first human tumor virus was discovered in the middle of the last century by Anthony Epstein, Bert Achong and Yvonne Barr in African pediatric patients with Burkitt’s lymphoma. To date, seven viruses -EBV, KSHV, high-risk HPV, MCPV, HBV, HCV and HTLV1- have been consistently linked to different types of human cancer, and infections are estimated to account for up to 20% of all cancer cases worldwide. Viral oncogenic mechanisms generally include: generation of genomic instability, increase in the rate of cell proliferation, resistance to apoptosis, alterations in DNA repair mechanisms and cell polarity changes, which often coexist with evasion mechanisms of the antiviral immune response. Viral agents also indirectly contribute to the development of cancer mainly through immunosuppression or chronic inflammation, but also through chronic antigenic stimulation. There is also evidence that viruses can modulate the malignant properties of an established tumor. In the present work, causation criteria for viruses and cancer will be described, as well as the viral agents that comply with these criteria in human tumors, their epidemiological and biological characteristics, the molecular mechanisms by which they induce cellular transformation and their associated cancers. PMID:25341666

  9. West Nile Virus

    MedlinePlus

    ... mosquitoes that probably picked up the virus after feeding on infected birds. Pets and other animals can also become infected ... after it has been washed a couple of times. Don't hang out near puddles or ... etc. If you find a dead bird, don't touch it with your bare hands ...

  10. Human immunodeficiency virus.

    PubMed

    Skinner, Anita

    2016-11-23

    What was the nature of the CPD activity, practice-related feedback and/or event and/or experience in your practice? The CPD article discussed the importance of human immunodeficiency virus (HIV) testing and diagnosing the condition as early as possible, so that antiretroviral treatment can be initiated and patient outcomes improved.

  11. Bat flight and zoonotic viruses

    USGS Publications Warehouse

    O'Shea, Thomas J.; Cryan, Paul M.; Cunningham, Andrew A.; Fooks, Anthony R.; Hayman, David T.S.; Luis, Angela D.; Peel, Alison J.; Plowright, Raina K.; Wood, James L.N.

    2014-01-01

    Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts.

  12. Bat Flight and Zoonotic Viruses

    PubMed Central

    Cryan, Paul M.; Cunningham, Andrew A.; Fooks, Anthony R.; Hayman, David T.S.; Luis, Angela D.; Peel, Alison J.; Plowright, Raina K.; Wood, James L.N.

    2014-01-01

    Bats are sources of high viral diversity and high-profile zoonotic viruses worldwide. Although apparently not pathogenic in their reservoir hosts, some viruses from bats severely affect other mammals, including humans. Examples include severe acute respiratory syndrome coronaviruses, Ebola and Marburg viruses, and Nipah and Hendra viruses. Factors underlying high viral diversity in bats are the subject of speculation. We hypothesize that flight, a factor common to all bats but to no other mammals, provides an intensive selective force for coexistence with viral parasites through a daily cycle that elevates metabolism and body temperature analogous to the febrile response in other mammals. On an evolutionary scale, this host–virus interaction might have resulted in the large diversity of zoonotic viruses in bats, possibly through bat viruses adapting to be more tolerant of the fever response and less virulent to their natural hosts. PMID:24750692

  13. Satellite RNAs and Satellite Viruses.

    PubMed

    Palukaitis, Peter

    2016-03-01

    Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the interaction of their helper viruses with their hosts. In only a few cases have the functions of these satellite RNAs in such interactions been studied in detail. In particular, work on the satellite RNAs of Cucumber mosaic virus and Turnip crinkle virus have provided novel insights into RNAs functioning as noncoding RNAs. These effects are described and potential roles for satellite RNAs in the processes involved in symptom intensification or attenuation are discussed. In most cases, models describing these roles involve some aspect of RNA silencing or its suppression, either directly or indirectly involving the particular satellite RNA.

  14. Avian influenza virus RNA extraction.

    PubMed

    Spackman, Erica; Lee, Scott A

    2014-01-01

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from experimentally infected birds. Samples can generally be divided into two types; enriched (e.g. virus stocks) and clinical. Clinical type samples, which may be tissues or swab material, are the most difficult to process due to the complex sample composition and possibly low virus titers. In this chapter two well established procedures for the isolation of AI virus RNA from common clinical specimen types and enriched virus stocks for further molecular applications will be presented.

  15. Animal Models of Zika Virus.

    PubMed

    P Bradley And Claude M Nagamine, Michael

    2017-03-07

    Zika virus has garnered great attention over the last several years, as outbreaks of the disease have emerged throughout the Western Hemisphere. Until quite recently Zika virus was considered a fairly benign virus, with limited clinical severity in both people and animals. The size and scope of the outbreak in the Western Hemisphere has allowed for the identification of severe clinical disease that is associated with Zika virus infection, most notably microcephaly among newborns, and an association with Guillian-Barré syndrome in adults. This recent association with severe clinical disease, of which further analysis strongly suggested causation by Zika virus, has resulted in a massive increase in the amount of both basic and applied research of this virus. Both small and large animal models are being used to uncover the pathogenesis of this emerging disease and to develop vaccine and therapeutic strategies. Here we review the animal-model-based Zika virus research that has been performed to date.

  16. Evolution of infectious salmon anaemia virus (ISA virus).

    PubMed

    Plarre, Heidrun; Nylund, Are; Karlsen, Marius; Brevik, Øyvind; Sæther, Per Anton; Vike, Siri

    2012-12-01

    Infectious salmon anaemia virus, ISA virus (genus Isavirus, family Orthomyxoviridae), emerged in Norwegian salmon culture in the mid-80s. The genome consists of eight segments coding for at least 10 proteins. ISA viruses show many of similarities to influenza A viruses but differ in many important aspects such as the number of hosts, the host population structure and the route of transmission. The only known hosts and reservoirs for ISA viruses are salmonids found in countries surrounding the North Atlantic. In this study, four different segments of the genome of about 100 ISA viruses have been sequenced in an attempt to understand the evolution of ISA viruses and how these viruses are maintained in and transmitted between populations of farmed Atlantic salmon. The four gene segments code for the nucleoprotein (NP), the putative acid polymerase (PA), the fusion protein (F) and the haemagglutinin-esterase (HE). Analysis of these four genes showed that the substitution rates of the internal proteins (NP and PA) are lower than those of the two surface proteins (F and HE). All four segments are evolving at a lower rate than similar genes in influenza A viruses. The ISA virus populations consist of avirulent viruses and pathogenic strains with variable virulence in Atlantic salmon. Recombination resulting in inserts close to the proteolytic-cleavage site of the precursor F0 protein and deletions in the stalk region of the HE protein seem to be responsible for the transition from avirulent ISA viruses to pathogenic strains. It is also shown that reassortment is a frequent event among the dominating ISA viruses in farmed Atlantic salmon. The pattern that is obtained after phylogenetic analysis of the four gene segments from ISA viruses suggests that the variation is limited to a few distinct clades and that no major changes have occurred in the ISA virus population in Norway since the first viruses were isolated. Calculation of the time of most recent common ancestor

  17. Viruses and neurodegeneration

    PubMed Central

    2013-01-01

    Neurodegenerative diseases (NDs) are chronic degenerative diseases of the central nervous system (CNS), which affect 37 million people worldwide. As the lifespan increases, the NDs are the fourth leading cause of death in the developed countries and becoming increasingly prevalent in developing countries. Despite considerable research, the underlying mechanisms remain poorly understood. Although the large majority of studies do not show support for the involvement of pathogenic aetiology in classical NDs, a number of emerging studies show support for possible association of viruses with classical neurodegenerative diseases in humans. Space does not permit for extensive details to be discussed here on non-viral-induced neurodegenerative diseases in humans, as they are well described in literature. Viruses induce alterations and degenerations of neurons both directly and indirectly. Their ability to attack the host immune system, regions of nervous tissue implies that they can interfere with the same pathways involved in classical NDs in humans. Supporting this, many similarities between classical NDs and virus-mediated neurodegeneration (non-classical) have been shown at the anatomic, sub-cellular, genomic and proteomic levels suggesting that viruses can explain neurodegenerative disorders mechanistically. The main objective of this review is to provide readers a detailed snapshot of similarities viral and non-viral neurodegenerative diseases share, so that mechanistic pathways of neurodegeneration in human NDs can be clearly understood. Viruses can guide us to unveil these pathways in human NDs. This will further stimulate the birth of new concepts in the biological research, which is needed for gaining deeper insights into the treatment of human NDs and delineate mechanisms underlying neurodegeneration. PMID:23724961

  18. Giant viruses: conflicts in revisiting the virus concept.

    PubMed

    Forterre, Patrick

    2010-01-01

    The current paradigm on the nature of viruses is based on early work of the 'phage group' (the pro-phage concept) and molecular biologists working on tumour viruses (the proto-oncogene concept). It posits that viruses evolved from either prokaryotic or eukaryotic cellular genes that became infectious via their association with capsid genes. In this view, after their emergence viruses continued to evolve by stealing cellular genes (the escape model). This paradigm has been challenged recently by scientists who propose that viruses pre-dated modern cells. In particular, the discovery of Mimivirus has stimulated a lot of discussions on the nature of viruses. There are two major schools of thought, those who defend the escape model, suggesting that giant viruses are giant pickpockets (chimera), and those who emphasize their uniqueness and ancient origin. Comparative genomics of Mimivirus and related viruses (nucleo-cytoplasmic large DNA viruses) have produced a lot of data that have been interpreted according to the prejudices of the authors and thus failed until now to generate a consensus. I briefly review here the history of these debates and how they lead to new proposals, such as the definition of viruses as capsid-encoding organisms or else the recognition of their fundamentally cellular nature, the virocell concept. Copyright 2010 S. Karger AG, Basel.

  19. Hepatitis E virus coinfection with hepatotropic viruses in Egyptian children.

    PubMed

    Zaki, Maysaa El Sayed; Salama, Osama Saad; Mansour, Fathy Awaad; Hossein, Shaimaa

    2008-06-01

    Major hepatotropic viruses continue to be important causes of acute viral hepatitis in developing countries. This work was carried out to detect the seroprevalence of hepatitis E virus (HEV) markers in children with acute viral hepatitis due to hepatotropic viruses (A, B and C) and non-A, non-B, non-C acute hepatitis, and to ascertain the influence of HEV superinfection in individuals infected with hepatitis viruses (A, B and C). We studied prospectively 162 children with sporadic acute hepatitis who reported to our hospital. Thirteen healthy controls were also included in the study. Laboratory investigations were performed, including complete liver function tests. Complete serological profiles for hepatitis viruses A, B, C and E were evaluated. HEV immunoglobulin G was detected with highest percentage among patients with hepatitis B (56.7%), followed by patients with hepatitis C virus (52.0%), hepatitis A virus (34.1%) and combined hepatitis B and C viruses (30.0%). The detection rate among patients with non-A, non-B, non-C hepatitis was 7.1%. HEV immunoglobulin M was found in 4.5% of hepatitis A virus patients and in 3.3% of hepatitis B patients. The prevalence of HEV immunoglobulin G and immunoglobulin M correlated with the levels of hepatic aspartate aminotransferase and alanine aminotransferase in patients with dual markers of infection with hepatitis E and other viruses compared to patients with acute hepatitis due to A and C viruses. HEV serological markers are common among children with acute viral hepatitis, especially from hepatitis C and B viruses. There may be increased sensitivity to HEV coinfection in association with hepatitis B and C infections. Dual infection with HEV and other hepatotropic viruses was associated with greater elevation of aspartate and alanine aminotransferases.

  20. Dengue virus antibodies enhance Zika virus infection

    PubMed Central

    Paul, Lauren M; Carlin, Eric R; Jenkins, Meagan M; Tan, Amanda L; Barcellona, Carolyn M; Nicholson, Cindo O; Michael, Scott F; Isern, Sharon

    2016-01-01

    For decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted human flavivirus, is both well-established and the source of outbreaks in areas of recent ZIKV introduction. DENV and ZIKV are closely related, resulting in substantial antigenic overlap. Through antibody-dependent enhancement (ADE), anti-DENV antibodies can enhance the infectivity of DENV for certain classes of immune cells, causing increased viral production that correlates with severe disease outcomes. Similarly, ZIKV has been shown to undergo ADE in response to antibodies generated by other flaviviruses. We tested the neutralizing and enhancing potential of well-characterized broadly neutralizing human anti-DENV monoclonal antibodies (HMAbs) and human DENV immune sera against ZIKV using neutralization and ADE assays. We show that anti-DENV HMAbs, cross-react, do not neutralize, and greatly enhance ZIKV infection in vitro. DENV immune sera had varying degrees of neutralization against ZIKV and similarly enhanced ZIKV infection. Our results suggest that pre-existing DENV immunity may enhance ZIKV infection in vivo and may lead to increased disease severity. Understanding the interplay between ZIKV and DENV will be critical in informing public health responses and will be particularly valuable for ZIKV and DENV vaccine design and implementation strategies. PMID:28090318

  1. Dengue virus antibodies enhance Zika virus infection.

    PubMed

    Paul, Lauren M; Carlin, Eric R; Jenkins, Meagan M; Tan, Amanda L; Barcellona, Carolyn M; Nicholson, Cindo O; Michael, Scott F; Isern, Sharon

    2016-12-01

    For decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted human flavivirus, is both well-established and the source of outbreaks in areas of recent ZIKV introduction. DENV and ZIKV are closely related, resulting in substantial antigenic overlap. Through antibody-dependent enhancement (ADE), anti-DENV antibodies can enhance the infectivity of DENV for certain classes of immune cells, causing increased viral production that correlates with severe disease outcomes. Similarly, ZIKV has been shown to undergo ADE in response to antibodies generated by other flaviviruses. We tested the neutralizing and enhancing potential of well-characterized broadly neutralizing human anti-DENV monoclonal antibodies (HMAbs) and human DENV immune sera against ZIKV using neutralization and ADE assays. We show that anti-DENV HMAbs, cross-react, do not neutralize, and greatly enhance ZIKV infection in vitro. DENV immune sera had varying degrees of neutralization against ZIKV and similarly enhanced ZIKV infection. Our results suggest that pre-existing DENV immunity may enhance ZIKV infection in vivo and may lead to increased disease severity. Understanding the interplay between ZIKV and DENV will be critical in informing public health responses and will be particularly valuable for ZIKV and DENV vaccine design and implementation strategies.

  2. Virus movement within grafted watermelon plants

    USDA-ARS?s Scientific Manuscript database

    Watermelon production in Florida is impacted by several viruses including whitefly-transmitted Squash vein yellowing virus (SqVYV), Cucurbit yellow stunting disorder virus and Cucurbit leaf crumple virus, and aphid-transmitted Papaya ringspot virus type W (PRSV-W). While germplasm resistant to some...

  3. Understanding Zika virus.

    PubMed

    Murray, John S

    2017-01-01

    This article describes what pediatric healthcare professionals should know about Zika virus (ZIKV). ZIKV is classified as an arthropod-borne, single-stranded RNA virus of the Flaviviridae family and genus Flavivirus. ZIKV is not new. The virus was first discovered almost 70 years ago in Uganda. The first isolate of the virus was found in rhesus monkeys in the Zika Forrest, hence the nomenclature. The primary route of ZIKV transmission to humans is through the bite of an infected Aedes species mosquito-primarily Aedes aegypti. When the mosquito bites individuals infected with the virus, mosquitos then become the vector of transmitting the infection to others. Women can also pass ZIKV to their fetus during pregnancy and at the time of delivery. ZIKV can also be transmitted through sexual activity from an individual who is infected with the virus to his or her partners. It is estimated that approximately 18% of individuals infected with ZIKV will go on to develop symptoms. When symptoms develop, it is usually within 3-12 days, although this may vary. Most often, symptoms are mild and self-limited. The most common symptoms are fever, arthralgia, maculopapular rash, and conjunctivitis lasting up to seven days. Less frequent symptoms include headache, vertigo, myalgia, vomiting, and diarrhea. At present, there is no vaccine available to prevent ZIKV and no specific antiviral treatment. Supportive care consisting of rest, hydration, analgesics, antihistamines, and antipyretics is recommended as needed. Given that there is no vaccine or treatment for ZIKV, considerable efforts must be focused on prevention. One of the most effective ways of preventing ZIKV infection is through avoiding mosquito bites, especially when traveling to or residing in areas where transmission is present. Precautions should include wearing appropriate attire with the objective of having as little skin exposed as possible, use of screens for windows and doors, and use of insect repellent. What is

  4. Detection of sweet potato viruses in Yunnan and genetic diversity analysis of the common viruses

    USDA-ARS?s Scientific Manuscript database

    Two hundred seventy-nine samples with virus-like symptoms collected from 16 regions in Yunnan Province were tested by RT-PCR/PCR using virus-specific primers for 8 sweet potato viruses. Six viruses, Sweet potato chlorotic fleck virus (SPCFV), Sweet Potato feathery mottle virus (SPFMV), Sweet potato ...

  5. The encephalomyocarditis virus

    PubMed Central

    Carocci, Margot; Bakkali-Kassimi, Labib

    2012-01-01

    The encephalomyocarditis virus (EMCV) is a small non-enveloped single-strand RNA virus, the causative agent of not only myocarditis and encephalitis, but also neurological diseases, reproductive disorders and diabetes in many mammalian species. EMCV pathogenesis appears to be viral strain- and host-specific, and a better understanding of EMCV virulence factors is increasingly required. Indeed, EMCV is often used as a model for diabetes and viral myocarditis, and is also widely used in immunology as a double-stranded RNA stimulus in the study of Toll-like as well as cytosolic receptors. However, EMCV virulence and properties have often been neglected. Moreover, EMCV is able to infect humans albeit with a low morbidity. Progress on xenografts, such as pig heart transplantation in humans, has raised safety concerns that need to be explored. In this review we will highlight the biology of EMCV and all known and potential virulence factors. PMID:22722247

  6. Hetdex: Virus Instrument

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hill, G. J.; DePoy, D. L.; Tuttle, S.; Marshall, J. L.; Vattiat, B. L.; Prochaska, T.; Chonis, T. S.; Allen, R.; HETDEX Collaboration

    2012-01-01

    The Visible Integral-field-unit Replicable Unit Spectrograph (VIRUS) instrument is made up of 150+ individually compact and identical spectrographs, each fed by a fiber integral-field unit. The instrument provides integral field spectroscopy at wavelengths between 350nm and 550nm of over 33,600 spatial elements per observation, each 1.8 sq. arcsec on the sky, at R 700. The instrument will be fed by a new wide-field corrector (WFC) of the Hobby-Eberly Telescope (HET) with increased science field of view as large as 22arcmin diameter and telescope aperture of 10m. This will enable the HETDEX, a large area blind survey of Lyman-alpha emitting galaxies at redshift z < 3.5. The status of VIRUS instrument construction is summarized.

  7. Hepatitis B Virus Epidemiology

    PubMed Central

    MacLachlan, Jennifer H.; Cowie, Benjamin C.

    2015-01-01

    The epidemiology of hepatitis B virus (HBV) infection is geographically diverse, with population prevalence, age and mode of acquisition, and likelihood of progression to chronic infection mutually interdependent. The burden of chronic HBV infection is increasingly being recognized, with cirrhosis and liver cancer attributable to HBV continuing to increase. The outcomes of chronic HBV infection are affected by a range of factors, including viral genotype, the presence of coinfections with other blood-borne viruses, and the impact of other causes of liver disease. The increased recognition of HBV infection as a leading cause of death globally has resulted in the development of new structures and policies at the international level; immediate attention to implementing these strategies is now required. PMID:25934461

  8. Mechanisms of Virus Assembly

    PubMed Central

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-01-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid, and in some cases surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assembles within their host cells and in vitro. We describe the thermodynamics and kinetics for assembly of protein subunits into icosahedral capsid shells, and how these are modified in cases where the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques that have been used to characterize capsid assembly, and we highlight aspects of virus assembly which are likely to receive significant attention in the near future. PMID:25532951

  9. Evolution of oncolytic viruses.

    PubMed

    Sanjuán, Rafael; Grdzelishvili, Valery Z

    2015-08-01

    Owing to their replicative capacity, oncolytic viruses (OVs) can evolve under the action of natural selection. Reversion to virulence and recombination with wild-type strains may compromise OV safety, therefore requiring evolutionary risk assessment studies. On the other hand, evolution can be directed in the laboratory to create more potent and safer OVs. Previous work in the experimental evolution field provides a background for OV directed evolution, and has identified interesting exploitable features. While genetic engineering has greatly advanced the field of oncolytic virotherapy, this approach is sometimes curtailed by the complexity and diversity of virus-host interactions. Directed evolution provides an alternative approach that may help to obtain new OVs without prejudice toward the underlying molecular mechanisms involved. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Mechanisms of Virus Assembly

    NASA Astrophysics Data System (ADS)

    Perlmutter, Jason D.; Hagan, Michael F.

    2015-04-01

    Viruses are nanoscale entities containing a nucleic acid genome encased in a protein shell called a capsid and in some cases are surrounded by a lipid bilayer membrane. This review summarizes the physics that govern the processes by which capsids assemble within their host cells and in vitro. We describe the thermodynamics and kinetics for the assembly of protein subunits into icosahedral capsid shells and how these are modified in cases in which the capsid assembles around a nucleic acid or on a lipid bilayer. We present experimental and theoretical techniques used to characterize capsid assembly, and we highlight aspects of virus assembly that are likely to receive significant attention in the near future.

  11. West Nile Virus

    PubMed Central

    Rossi, Shannan L.; Ross, Ted M.; Evans, Jared D.

    2010-01-01

    Overview Since its isolation in Uganda in 1937, West Nile virus (WNV) has been responsible for thousands of cases of morbidity and mortality in birds, horses, and humans. Historically, epidemics were localized to Europe, Africa, the Middle East, and parts of Asia, and primarily caused a mild febrile illness in humans. However, in the late 1990’s, the virus became more virulent and expanded its geographical range to North America. In humans, the clinical presentation ranges from asymptomatic (approximately 80% of infections) to encephalitis/paralysis and death (less than 1% of infections). There is no FDA-licensed vaccine for human use, and the only recommended treatment is supportive care. Individuals that survive infection often have a long recovery period. This article will review the current literature summarizing the molecular virology, epidemiology, clinical manifestations, pathogenesis, diagnosis, treatment, immunology, and protective measures against WNV and WNV infections in humans. PMID:20513541

  12. [Ebola virus disease: Update].

    PubMed

    de la Calle-Prieto, Fernando; Arsuaga-Vicente, Marta; Mora-Rillo, Marta; Arnalich-Fernandez, Francisco; Arribas, Jose Ramon

    2016-01-01

    The first known Ebola outbreak occurred in 1976. Since then, 24 limited outbreaks had been reported in Central Africa, but never affecting more than 425 persons. The current outbreak in Western Africa is the largest in history with 28,220 reported cases and 11,291 deaths. The magnitude of the epidemic has caused worldwide alarm. For the first time, evacuated patients were treated outside Africa, and secondary cases have occurred in Spain and the United States. Since the start of the current epidemic, our knowledge about the epidemiology, clinical picture, laboratory findings, and virology of Ebola virus disease has considerably expanded. For the first time, experimental treatment has been tried, and there have been spectacular advances in vaccine development. A review is presented of these advances in the knowledge of Ebola virus disease.

  13. Phage Displayed Peptides to Avian H5N1 Virus Distinguished the Virus from Other Viruses

    PubMed Central

    Qin, Chengfeng; Ren, Xiaofeng

    2011-01-01

    The purpose of the current study was to identify potential ligands and develop a novel diagnostic test to highly pathogenic avian influenza A virus (HPAI), subtype H5N1 viruses using phage display technology. The H5N1 viruses were used as an immobilized target in a biopanning process using a 12-mer phage display random peptide library. After five rounds of panning, three phages expressing peptides HAWDPIPARDPF, AAWHLIVALAPN or ATSHLHVRLPSK had a specific binding activity to H5N1 viruses were isolated. Putative binding motifs to H5N1 viruses were identified by DNA sequencing. In terms of the minimum quantity of viruses, the phage-based ELISA was better than antiserum-based ELISA and a manual, semi-quantitative endpoint RT-PCR for detecting H5N1 viruses. More importantly, the selected phages bearing the specific peptides to H5N1 viruses were capable of differentiating this virus from other avian viruses in enzyme-linked immunosorbent assays. PMID:21887228

  14. Phage displayed peptides to avian H5N1 virus distinguished the virus from other viruses.

    PubMed

    Wu, Dan; Li, Guangxing; Qin, Chengfeng; Ren, Xiaofeng

    2011-01-01

    The purpose of the current study was to identify potential ligands and develop a novel diagnostic test to highly pathogenic avian influenza A virus (HPAI), subtype H5N1 viruses using phage display technology. The H5N1 viruses were used as an immobilized target in a biopanning process using a 12-mer phage display random peptide library. After five rounds of panning, three phages expressing peptides HAWDPIPARDPF, AAWHLIVALAPN or ATSHLHVRLPSK had a specific binding activity to H5N1 viruses were isolated. Putative binding motifs to H5N1 viruses were identified by DNA sequencing. In terms of the minimum quantity of viruses, the phage-based ELISA was better than antiserum-based ELISA and a manual, semi-quantitative endpoint RT-PCR for detecting H5N1 viruses. More importantly, the selected phages bearing the specific peptides to H5N1 viruses were capable of differentiating this virus from other avian viruses in enzyme-linked immunosorbent assays.

  15. VIRUS instrument collimator assembly

    NASA Astrophysics Data System (ADS)

    Marshall, Jennifer L.; DePoy, Darren L.; Prochaska, Travis; Allen, Richard D.; Williams, Patrick; Rheault, Jean-Philippe; Li, Ting; Nagasawa, Daniel Q.; Akers, Christopher; Baker, David; Boster, Emily; Campbell, Caitlin; Cook, Erika; Elder, Alison; Gary, Alex; Glover, Joseph; James, Michael; Martin, Emily; Meador, Will; Mondrik, Nicholas; Rodriguez-Patino, Marisela; Villanueva, Steven; Hill, Gary J.; Tuttle, Sarah; Vattiat, Brian; Lee, Hanshin; Chonis, Taylor S.; Dalton, Gavin B.; Tacon, Mike

    2014-07-01

    The Visual Integral-Field Replicable Unit Spectrograph (VIRUS) instrument is a baseline array 150 identical fiber fed optical spectrographs designed to support observations for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). The collimator subassemblies of the instrument have been assembled in a production line and are now complete. Here we review the design choices and assembly practices used to produce a suite of identical low-cost spectrographs in a timely fashion using primarily unskilled labor.

  16. Hepatitis C Virus.

    PubMed

    Kim, Arthur

    2016-09-06

    This issue provides a clinical overview of hepatitis C virus, focusing on transmission, prevention, screening, diagnosis, evaluation, and treatment. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of additional science writers and physician writers.

  17. Proteorhodopsin genes in giant viruses.

    PubMed

    Yutin, Natalya; Koonin, Eugene V

    2012-10-04

    Viruses with large genomes encode numerous proteins that do not directly participate in virus biogenesis but rather modify key functional systems of infected cells. We report that a distinct group of giant viruses infecting unicellular eukaryotes that includes Organic Lake Phycodnaviruses and Phaeocystis globosa virus encode predicted proteorhodopsins that have not been previously detected in viruses. Search of metagenomic sequence data shows that putative viral proteorhodopsins are extremely abundant in marine environments. Phylogenetic analysis suggests that giant viruses acquired proteorhodopsins via horizontal gene transfer from proteorhodopsin-encoding protists although the actual donor(s) could not be presently identified. The pattern of conservation of the predicted functionally important amino acid residues suggests that viral proteorhodopsin homologs function as sensory rhodopsins. We hypothesize that viral rhodopsins modulate light-dependent signaling, in particular phototaxis, in infected protists.

  18. Hepatitis C virus infection.

    PubMed

    Manns, Michael P; Buti, Maria; Gane, Ed; Pawlotsky, Jean-Michel; Razavi, Homie; Terrault, Norah; Younossi, Zobair

    2017-03-02

    Hepatitis C virus (HCV) is a hepatotropic RNA virus that causes progressive liver damage, which might result in liver cirrhosis and hepatocellular carcinoma. Globally, between 64 and 103 million people are chronically infected. Major risk factors for this blood-borne virus infection are unsafe injection drug use and unsterile medical procedures (iatrogenic infections) in countries with high HCV prevalence. Diagnostic procedures include serum HCV antibody testing, HCV RNA measurement, viral genotype and subtype determination and, lately, assessment of resistance-associated substitutions. Various direct-acting antiviral agents (DAAs) have become available, which target three proteins involved in crucial steps of the HCV life cycle: the NS3/4A protease, the NS5A protein and the RNA-dependent RNA polymerase NS5B protein. Combination of two or three of these DAAs can cure (defined as a sustained virological response 12 weeks after treatment) HCV infection in >90% of patients, including populations that have been difficult to treat in the past. As long as a prophylactic vaccine is not available, the HCV pandemic has to be controlled by treatment-as-prevention strategies, effective screening programmes and global access to treatment.

  19. [Ebola virus disease].

    PubMed

    Karwowska, Kornelia

    2015-01-01

    Ebola virus disease is a zoonosis causing high mortality epidemics in both human and animal populations. The virus belongs to the Filoviride family. It is composed of a single-strand of RNA. Morbidity foci appear in sub-Saharan Africa. The most probable reservoir are fruit bats, which are local delicacy. The most common route of infection is via mucosa or damaged skin. The spread of disease is rapid due to dietary habits, funeral rites and the insufficient supply of disposable equipment in hospitals. The incubation period of the disease ranges from 2 to 21 days. The beginning is abrupt, dominated by influenza-like symptoms. The disease is staggering with the predominant multi-organ failure and shock. Present-day epidemic symptoms from digestive system in the form of vomiting and diarrhoea are dominant. Currently, the research on vaccine and experimental drug is in progress. The virus is damaged by standard disinfectants used in health care units. Epidemic, which broke out in February 2014, caused by the most dangerous type Zaire, is the greatest of the existing. Morbidity and mortality is underestimated due to numerous unreported cases.

  20. Ebola Virus Disease

    PubMed Central

    Kourtis, Athena P.; Appelgren, Kristie; Chevalier, Michelle S.; McElroy, Anita

    2015-01-01

    Ebola virus is one of the most deadly pathogens known to infect humans. The current Ebola outbreak in West Africa is unprecedented in magnitude and duration and, as of November 30, 2014, shows no signs of abating. For the first time, cases of Ebola virus disease have been diagnosed in the US, originating from patients who traveled during the incubation period. The outbreak has generated worldwide concern. It is clear that U.S. physicians need to be aware of this disease, know when to consider Ebola and how to care for the patient as well as protect themselves. Children comprise a small percentage of all cases globally, likely because of their lower risk of exposure given social and cultural practices. Limited evidence is available on pediatric disease course and prognosis. In this article, we present an overview of the pathogen, its epidemiology and transmission, clinical and laboratory manifestations, treatment and infection control procedures, with an emphasis on what is known about Ebola virus disease in the pediatric population. PMID:25831417

  1. Zika Virus: Know Before You Go

    MedlinePlus

    ... JavaScript on. Feature: Zika Virus Know Before You Go Past Issues / Summer 2016 Table of Contents If ... Virus" Articles Understanding Zika Virus / Know Before You Go Summer 2016 Issue: Volume 11 Number 2 Page ...

  2. Learn about Respiratory Syncytial Virus (RSV)

    MedlinePlus

    ... Virus (RSV) Respiratory syncytial virus (RSV) is a common respiratory virus that can affect people of all ages. In older children and adults, it causes mostly upper respiratory symptoms (colds), but it can cause a serious infection in ...

  3. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... Types Seasonal Avian Swine Variant Other Variant Influenza Viruses: Background and CDC Risk Assessment and Reporting Language: ... Background CDC Assessment Reporting Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  4. Zika Mosquito Can Transmit Other Viruses, Too

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_165752.html Zika Mosquito Can Transmit Other Viruses, Too 3-in- ... mosquito species that's the main carrier of the Zika virus might also transmit two other viruses -- chikungunya ...

  5. Introducing Virological Concepts Using an Insect Virus.

    ERIC Educational Resources Information Center

    Sheppard, Roger F.

    1980-01-01

    A technique is presented which utilizes wax moth larvae in a laboratory investigation of an insect virus. Describes how an insect virus can be used to introduce undergraduate biology students to laboratory work on viruses and several virological concepts. (SA)

  6. Introducing Virological Concepts Using an Insect Virus.

    ERIC Educational Resources Information Center

    Sheppard, Roger F.

    1980-01-01

    A technique is presented which utilizes wax moth larvae in a laboratory investigation of an insect virus. Describes how an insect virus can be used to introduce undergraduate biology students to laboratory work on viruses and several virological concepts. (SA)

  7. Air sampling of smallpox virus

    PubMed Central

    Thomas, G.

    1974-01-01

    Airborne smallpox virus has been recovered in an isolation hospital using an adhesive surface sampling technique in the presence of very low aerosol concentrations. Previous work in this field is reviewed. Successful recovery of airborne virus depends on sampling large volumes of air with a suitable sampler and thorough investigation of the whole sample taken for the presence of viable virus. More information on the characteristics and behaviour of airborne smallpox virus is needed in particular with regard to the future design and siting of smallpox isolation units. PMID:4371586

  8. Are Viruses Important in Carcinogenesis?

    PubMed Central

    Rapp, Fred; Buss, Ellen R.

    1974-01-01

    The role of viruses in the etiology of animal cancers is fairly certain. Information derived under both natural and experimental conditions supports the concept that either DNA- or RNA-containing viruses can fulfill this function. The DNA-containing herpesviruses, especially the Epstein-Barr virus, are currently the primary objects of intense investigation concerning their role in human cancer. This article will focus on the properties of counterpart herpesviruses in lower animals as well as the human virus candidates with an assessment of the observations concerning their oncogenic potential. ImagesFig 1 PMID:4374889

  9. RECOVIR Software for Identifying Viruses

    NASA Technical Reports Server (NTRS)

    Chakravarty, Sugoto; Fox, George E.; Zhu, Dianhui

    2013-01-01

    Most single-stranded RNA (ssRNA) viruses mutate rapidly to generate a large number of strains with highly divergent capsid sequences. Determining the capsid residues or nucleotides that uniquely characterize these strains is critical in understanding the strain diversity of these viruses. RECOVIR (an acronym for "recognize viruses") software predicts the strains of some ssRNA viruses from their limited sequence data. Novel phylogenetic-tree-based databases of protein or nucleic acid residues that uniquely characterize these virus strains are created. Strains of input virus sequences (partial or complete) are predicted through residue-wise comparisons with the databases. RECOVIR uses unique characterizing residues to identify automatically strains of partial or complete capsid sequences of picorna and caliciviruses, two of the most highly diverse ssRNA virus families. Partition-wise comparisons of the database residues with the corresponding residues of more than 300 complete and partial sequences of these viruses resulted in correct strain identification for all of these sequences. This study shows the feasibility of creating databases of hitherto unknown residues uniquely characterizing the capsid sequences of two of the most highly divergent ssRNA virus families. These databases enable automated strain identification from partial or complete capsid sequences of these human and animal pathogens.

  10. Nuclear entry of DNA viruses

    PubMed Central

    Fay, Nikta; Panté, Nelly

    2015-01-01

    DNA viruses undertake their replication within the cell nucleus, and therefore they must first deliver their genome into the nucleus of their host cells. Thus, trafficking across the nuclear envelope is at the basis of DNA virus infections. Nuclear transport of molecules with diameters up to 39 nm is a tightly regulated process that occurs through the nuclear pore complex (NPC). Due to the enormous diversity of virus size and structure, each virus has developed its own strategy for entering the nucleus of their host cells, with no two strategies alike. For example, baculoviruses target their DNA-containing capsid to the NPC and subsequently enter the nucleus intact, while the hepatitis B virus capsid crosses the NPC but disassembles at the nuclear side of the NPC. For other viruses such as herpes simplex virus and adenovirus, although both dock at the NPC, they have each developed a distinct mechanism for the subsequent delivery of their genome into the nucleus. Remarkably, other DNA viruses, such as parvoviruses and human papillomaviruses, access the nucleus through an NPC-independent mechanism. This review discusses our current understanding of the mechanisms used by DNA viruses to deliver their genome into the nucleus, and further presents the experimental evidence for such mechanisms. PMID:26029198

  11. Limits in virus filtration capability? Impact of virus quality and spike level on virus removal with xenotropic murine leukemia virus.

    PubMed

    Roush, David J; Myrold, Adam; Burnham, Michael S; And, Joseph V; Hughes, Joseph V

    2015-01-01

    Virus filtration (VF) is a key step in an overall viral clearance process since it has been demonstrated to effectively clear a wide range of mammalian viruses with a log reduction value (LRV) > 4. The potential to achieve higher LRV from virus retentive filters has historically been examined using bacteriophage surrogates, which commonly demonstrated a potential of > 9 LRV when using high titer spikes (e.g. 10(10) PFU/mL). However, as the filter loading increases, one typically experiences significant decreases in performance and LRV. The 9 LRV value is markedly higher than the current expected range of 4-5 LRV when utilizing mammalian retroviruses on virus removal filters (Miesegaes et al., Dev Biol (Basel) 2010;133:3-101). Recent values have been reported in the literature (Stuckey et al., Biotech Progr 2014;30:79-85) of LRV in excess of 6 for PPV and XMuLV although this result appears to be atypical. LRV for VF with therapeutic proteins could be limited by several factors including process limits (flux decay, load matrix), virus spike level and the analytical methods used for virus detection (i.e. the Limits of Quantitation), as well as the virus spike quality. Research was conducted using the Xenotropic-Murine Leukemia Virus (XMuLV) for its direct relevance to the most commonly cited document, the International Conference of Harmonization (ICH) Q5A (International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, Geneva, Switzerland, 1999) for viral safety evaluations. A unique aspect of this work is the independent evaluation of the impact of retrovirus quality and virus spike level on VF performance and LRV. The VF studies used XMuLV preparations purified by either ultracentrifugation (Ultra 1) or by chromatographic processes that yielded a more highly purified virus stock (Ultra 2). Two monoclonal antibodies (Mabs) with markedly different filtration characteristics and with similar levels of

  12. Genome of Crocodilepox Virus

    PubMed Central

    Afonso, C. L.; Tulman, E. R.; Delhon, G.; Lu, Z.; Viljoen, G. J.; Wallace, D. B.; Kutish, G. F.; Rock, D. L.

    2006-01-01

    Here, we present the genome sequence, with analysis, of a poxvirus infecting Nile crocodiles (Crocodylus niloticus) (crocodilepox virus; CRV). The genome is 190,054 bp (62% G+C) and predicted to contain 173 genes encoding proteins of 53 to 1,941 amino acids. The central genomic region contains genes conserved and generally colinear with those of other chordopoxviruses (ChPVs). CRV is distinct, as the terminal 33-kbp (left) and 13-kbp (right) genomic regions are largely CRV specific, containing 48 unique genes which lack similarity to other poxvirus genes. Notably, CRV also contains 14 unique genes which disrupt ChPV gene colinearity within the central genomic region, including 7 genes encoding GyrB-like ATPase domains similar to those in cellular type IIA DNA topoisomerases, suggestive of novel ATP-dependent functions. The presence of 10 CRV proteins with similarity to components of cellular multisubunit E3 ubiquitin-protein ligase complexes, including 9 proteins containing F-box motifs and F-box-associated regions and a homologue of cellular anaphase-promoting complex subunit 11 (Apc11), suggests that modification of host ubiquitination pathways may be significant for CRV-host cell interaction. CRV encodes a novel complement of proteins potentially involved in DNA replication, including a NAD+-dependent DNA ligase and a protein with similarity to both vaccinia virus F16L and prokaryotic serine site-specific resolvase-invertases. CRV lacks genes encoding proteins for nucleotide metabolism. CRV shares notable genomic similarities with molluscum contagiosum virus, including genes found only in these two viruses. Phylogenetic analysis indicates that CRV is quite distinct from other ChPVs, representing a new genus within the subfamily Chordopoxvirinae, and it lacks recognizable homologues of most ChPV genes involved in virulence and host range, including those involving interferon response, intracellular signaling, and host immune response modulation. These data reveal

  13. Innate immunity modulation in virus entry.

    PubMed

    Faure, Mathias; Rabourdin-Combe, Chantal

    2011-07-01

    Entry into a cell submits viruses to detection by pattern recognition receptors (PRRs) leading to an early innate anti-viral response. Several viruses evolved strategies to avoid or subvert PRR recognition at the step of virus entry to promote infection. Whereas viruses mostly escape from soluble PRR detection, endocytic/phagocytic PRRs, such as the mannose receptor or DC-SIGN, are commonly used for virus entry. Moreover, virion-incorporated proteins may also offer viruses a way to dampen anti-viral innate immunity upon virus entry, and entering viruses might usurp autophagy to improve their own infectivity. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Structure of flexible filamentous plant viruses.

    PubMed

    Kendall, Amy; McDonald, Michele; Bian, Wen; Bowles, Timothy; Baumgarten, Sarah C; Shi, Jian; Stewart, Phoebe L; Bullitt, Esther; Gore, David; Irving, Thomas C; Havens, Wendy M; Ghabrial, Said A; Wall, Joseph S; Stubbs, Gerald

    2008-10-01

    Flexible filamentous viruses make up a large fraction of the known plant viruses, but in comparison with those of other viruses, very little is known about their structures. We have used fiber diffraction, cryo-electron microscopy, and scanning transmission electron microscopy to determine the symmetry of a potyvirus, soybean mosaic virus; to confirm the symmetry of a potexvirus, potato virus X; and to determine the low-resolution structures of both viruses. We conclude that these viruses and, by implication, most or all flexible filamentous plant viruses share a common coat protein fold and helical symmetry, with slightly less than 9 subunits per helical turn.

  15. Computer virus information update CIAC-2301

    SciTech Connect

    Orvis, W.J.

    1994-01-15

    While CIAC periodically issues bulletins about specific computer viruses, these bulletins do not cover all the computer viruses that affect desktop computers. The purpose of this document is to identify most of the known viruses for the MS-DOS and Macintosh platforms and give an overview of the effects of each virus. The authors also include information on some windows, Atari, and Amiga viruses. This document is revised periodically as new virus information becomes available. This document replaces all earlier versions of the CIAC Computer virus Information Update. The date on the front cover indicates date on which the information in this document was extracted from CIAC`s Virus database.

  16. Structure of Flexible Filamentous Plant Viruses

    SciTech Connect

    Kendall, Amy; McDonald, Michele; Bian, Wen; Bowles, Timothy; Baumgarten, Sarah C.; Shi, Jian; Stewart, Phoebe L.; Bullitt, Esther; Gore, David; Irving, Thomas C.; Havens, Wendy M.; Ghabrial, Said A.; Wall, Joseph S.; Stubbs, Gerald

    2008-10-23

    Flexible filamentous viruses make up a large fraction of the known plant viruses, but in comparison with those of other viruses, very little is known about their structures. We have used fiber diffraction, cryo-electron microscopy, and scanning transmission electron microscopy to determine the symmetry of a potyvirus, soybean mosaic virus; to confirm the symmetry of a potexvirus, potato virus X; and to determine the low-resolution structures of both viruses. We conclude that these viruses and, by implication, most or all flexible filamentous plant viruses share a common coat protein fold and helical symmetry, with slightly less than 9 subunits per helical turn.

  17. Tomato chlorosis virus and Tomato infectious chlorosis virus

    USDA-ARS?s Scientific Manuscript database

    This presentation will help consultants, growers, and other practitioners in the Southern and Western Regions of the US, as well as Mexico and the Caribbean identify and manage Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV) in tomato. Information will directly benefit cr...

  18. Parainfluenza Virus 5 Expressing the G Protein of Rabies Virus Protects Mice after Rabies Virus Infection

    PubMed Central

    Huang, Ying; Chen, Zhenhai; Huang, Junhua

    2014-01-01

    Rabies remains a major public health threat around the world. Once symptoms appear, there is no effective treatment to prevent death. In this work, we tested a recombinant parainfluenza virus 5 (PIV5) strain expressing the glycoprotein (G) of rabies (PIV5-G) as a therapy for rabies virus infection: we have found that PIV5-G protected mice as late as 6 days after rabies virus infection. PIV5-G is a promising vaccine for prevention and treatment of rabies virus infection. PMID:25552723

  19. Uukuniemi Virus as a Tick-Borne Virus Model

    PubMed Central

    Mazelier, Magalie; Rouxel, Ronan Nicolas; Zumstein, Michael; Mancini, Roberta; Bell-Sakyi, Lesley

    2016-01-01

    ABSTRACT In the last decade, novel tick-borne pathogenic phleboviruses in the family Bunyaviridae, all closely related to Uukuniemi virus (UUKV), have emerged on different continents. To reproduce the tick-mammal switch in vitro, we first established a reverse genetics system to rescue UUKV with a genome close to that of the authentic virus isolated from the Ixodes ricinus tick reservoir. The IRE/CTVM19 and IRE/CTVM20 cell lines, both derived from I. ricinus, were susceptible to the virus rescued from plasmid DNAs and supported production of the virus over many weeks, indicating that infection was persistent. The glycoprotein GC was mainly highly mannosylated on tick cell-derived viral progeny. The second envelope viral protein, GN, carried mostly N-glycans not recognized by the classical glycosidases peptide-N-glycosidase F (PNGase F) and endoglycosidase H (Endo H). Treatment with β-mercaptoethanol did not impact the apparent molecular weight of GN. On viruses originating from mammalian BHK-21 cells, GN glycosylations were exclusively sensitive to PNGase F, and the electrophoretic mobility of the protein was substantially slower after the reduction of disulfide bonds. Furthermore, the amount of viral nucleoprotein per focus forming unit differed markedly whether viruses were produced in tick or BHK-21 cells, suggesting a higher infectivity for tick cell-derived viruses. Together, our results indicate that UUKV particles derived from vector tick cells have glycosylation and structural specificities that may influence the initial infection in mammalian hosts. This study also highlights the importance of working with viruses originating from arthropod vector cells in investigations of the cell biology of arbovirus transmission and entry into mammalian hosts. IMPORTANCE Tick-borne phleboviruses represent a growing threat to humans globally. Although ticks are important vectors of infectious emerging diseases, previous studies have mainly involved virus stocks

  20. Virus genomes and virus-host interactions in aquaculture animals.

    PubMed

    Zhang, QiYa; Gui, Jian-Fang

    2015-02-01

    Over the last 30 years, aquaculture has become the fastest growing form of agriculture production in the world, but its development has been hampered by a diverse range of pathogenic viruses. During the last decade, a large number of viruses from aquatic animals have been identified, and more than 100 viral genomes have been sequenced and genetically characterized. These advances are leading to better understanding about antiviral mechanisms and the types of interaction occurring between aquatic viruses and their hosts. Here, based on our research experience of more than 20 years, we review the wealth of genetic and genomic information from studies on a diverse range of aquatic viruses, including iridoviruses, herpesviruses, reoviruses, and rhabdoviruses, and outline some major advances in our understanding of virus-host interactions in animals used in aquaculture.

  1. Cowpea mosaic virus: the plant virus-based biotechnology workhorse.

    PubMed

    Sainsbury, Frank; Cañizares, M Carmen; Lomonossoff, George P

    2010-01-01

    In the 50 years since it was first described, Cowpea mosaic virus (CPMV) has become one of the most intensely studied plant viruses. Research in the past 15 to 20 years has shifted from studying the underlying genetics and structure of the virus to focusing on ways in which it can be exploited in biotechnology. This work led first to the use of virus particles to present peptides, then to the creation of a variety of replicating virus vectors and finally to the development of a highly efficient protein expression system that does not require viral replication. The circle has been completed by the use of the latter system to create empty particles for peptide presentation and other novel uses. The history of CPMV in biotechnology can be likened to an Ouroborus, an ancient symbol depicting a snake or dragon swallowing its own tail, thus forming a circle.

  2. Multiplexed dual second-dimension column comprehensive two-dimensional gas chromatography (GC × 2GC) using thermal modulation and contra-directional second-dimension columns.

    PubMed

    Savareear, Benjamin; Shellie, Robert A

    2013-11-25

    A multiplexed dual-secondary column comprehensive two-dimensional gas chromatography approach (GC×2GC) designed for complex sample analysis is introduced. The approach splits the first-dimension column effluent into two second-dimension columns with different stationary phases, and recombines the two streams into one detector post-separation. The approach produces two single two-dimensional chromatograms for each injection. Careful manipulation of thermal modulator timing parameters combined with a novel contra-directional modulation regime facilitates this approach. A selection of 34 laboratory reference compounds containing n-alkanes, alcohols, aromatic hydrocarbons, ketones, esters and halogenated hydrocarbons were analysed to demonstrate the approach. The dual two-dimensional chromatogram from this single detector system provides complementary information due to the unique selectivity of the three separation columns. The results of this proof-of-principle investigation provide significant impetus for further development of GC×2GC-MS methodology. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Epidemiological study of the incidence of cancer as related to industrial emissions in Contra Costa County, California. Final report September 1978-December 1982

    SciTech Connect

    Austin, D.F.; Nelson, V.E.; Swain, B.E.; Johnson, L.F.

    1984-06-01

    The purpose of this study was to examine the relationship of lung cancer incidence in Contra Costa County to ambient levels of air pollution. It was suspected that the presence of heavy industry in the county, mainly petrochemical plants and oil refineries, could be a contributing factor. Initially, an incidence analysis established that the industrial portion of the county had an excess of lung cancer as compared to the remaining non-industrial portion. Air pollution patterns were subsequently determined by five permanent air monitoring stations and ten temporary stations which monitored the levels of 12 air pollutants for a period of one year. By correlating the 1970-79 lung cancer rates for each census tract and tract levels of air pollution constituents, a statistically significant relationship between ambient air SO4 and lung cancer in males, but not in females, was found. However, when adjusted for the percent of the working population categorized as blue collar, the association was eliminated. An interview study of 249 cases and 373 controls was then conducted. Demographic, work history, residential history, dietary, and smoking history questions comprised the bulk of the data collected. Analysis indicated that the major contribution to lung cancer in the county was due to cigarette smoking. No significant association between lung cancer risk and measured constituents of air pollution was found. Of five broad occupational categories (indicating possible hazardous exposures) none had any significant relationship to lung cancer.

  4. Application of an Aligned and Unaligned Signal Processing Technique to Investigate Tones and Broadband Noise in Fan and Contra-Rotating Open Rotor Acoustic Spectra

    NASA Technical Reports Server (NTRS)

    Miles, Jeffrey Hilton; Hultgren, Lennart S.

    2015-01-01

    The study of noise from a two-shaft contra-rotating open rotor (CROR) is challenging since the shafts are not phase locked in most cases. Consequently, phase averaging of the acoustic data keyed to a single shaft rotation speed is not meaningful. An unaligned spectrum procedure that was developed to estimate a signal coherence threshold and reveal concealed spectral lines in turbofan engine combustion noise is applied to fan and CROR acoustic data in this paper (also available as NASA/TM-2015-218865). The NASA Advanced Air Vehicles Program, Advanced Air Transport Technology Project, Aircraft Noise Reduction Subproject supported the current work. The fan and open rotor data were obtained under previous efforts supported by the NASA Quiet Aircraft Technology (QAT) Project and the NASA Environmentally Responsible Aviation (ERA) Project of the Integrated Systems Research Program in collaboration with GE Aviation, respectively. The overarching goal of the Advanced Air Transport (AATT) Project is to explore and develop technologies and concepts to revolutionize the energy efficiency and environmental compatibility of fixed wing transport aircrafts. These technological solutions are critical in reducing the impact of aviation on the environment even as this industry and the corresponding global transportation system continue to grow.

  5. Serological behaviour of influenza viruses

    PubMed Central

    Fiset, P.; Depoux, R.

    1954-01-01

    By antibody absorption it was found that strains of influenza virus exhibiting P-Q differences were related according to certain patterns. In the course of this investigation it was also revealed that some viruses possessed masked antigens capable of stimulating antibody production but incapable of combining efficiently with antibody. PMID:14364182

  6. TOTAL CULTURABLE VIRUS QUANTAL ASSAY

    EPA Science Inventory

    This chapter describes a quantal method for assaying culturable human enteric viruses from water matrices. The assay differs from the plaque assay described in Chapter 10 (December 1987 Revision) in that it is based upon the direct microscopic viewing of cells for virus-induced ...

  7. Swine Influenza Virus: Emerging Understandings

    USDA-ARS?s Scientific Manuscript database

    Introduction: In March-April 2009, a novel pandemic H1N1 emerged in the human population in North America [1]. The gene constellation of the emerging virus was demonstrated to be a combination of genes from swine influenza A viruses (SIV) of North American and Eurasian lineages that had never before...

  8. Soy isoflavones and virus infections

    USDA-ARS?s Scientific Manuscript database

    Isoflavones and their related flavonoid compounds exert antiviral properties in vitro and in vivo against a wide range of viruses. Genistein is, by far, the most studied soy isoflavone in this regard, and it has been shown to inhibit the infectivity of enveloped or nonenveloped viruses, as well as s...

  9. Cucurbit yellow stunting disorder virus

    USDA-ARS?s Scientific Manuscript database

    Cucurbit yellow stunting disorder virus (CYSDV), a whitefly-transmitted virus (genus Crinivirus, family Closteroviridae) is distributed throughout the Middle East, most of the Mediterranean Basin, North America, and Central America. Symptoms are similar on most cucurbits, although early mottle symp...

  10. Beet pseudo-yellows virus

    USDA-ARS?s Scientific Manuscript database

    Beet pseudo-yellows virus (BPYV), a whitefly-transmitted virus (genus Crinivirus, family Closteroviridae). BPYV is particularly important in greenhouse production where its vector, the greenhouse whitefly, is often a chronic problem, as well as in cooler Mediterranean climates. Initial symptoms con...

  11. Virioplankton: Viruses in Aquatic Ecosystems†

    PubMed Central

    Wommack, K. Eric; Colwell, Rita R.

    2000-01-01

    The discovery that viruses may be the most abundant organisms in natural waters, surpassing the number of bacteria by an order of magnitude, has inspired a resurgence of interest in viruses in the aquatic environment. Surprisingly little was known of the interaction of viruses and their hosts in nature. In the decade since the reports of extraordinarily large virus populations were published, enumeration of viruses in aquatic environments has demonstrated that the virioplankton are dynamic components of the plankton, changing dramatically in number with geographical location and season. The evidence to date suggests that virioplankton communities are composed principally of bacteriophages and, to a lesser extent, eukaryotic algal viruses. The influence of viral infection and lysis on bacterial and phytoplankton host communities was measurable after new methods were developed and prior knowledge of bacteriophage biology was incorporated into concepts of parasite and host community interactions. The new methods have yielded data showing that viral infection can have a significant impact on bacteria and unicellular algae populations and supporting the hypothesis that viruses play a significant role in microbial food webs. Besides predation limiting bacteria and phytoplankton populations, the specific nature of virus-host interaction raises the intriguing possibility that viral infection influences the structure and diversity of aquatic microbial communities. Novel applications of molecular genetic techniques have provided good evidence that viral infection can significantly influence the composition and diversity of aquatic microbial communities. PMID:10704475

  12. Influenza Virus Assembly and Budding

    PubMed Central

    Rossman, Jeremy S.; Lamb, Robert A.

    2011-01-01

    Influenza A virus causes seasonal epidemics, sporadic pandemics and is a significant global heath burden. Influenza virus is an enveloped virus that contains a segmented negative strand RNA genome. Assembly and budding of progeny influenza virions is a complex, multistep process that occurs in lipid raft domains on the apical membrane of infected cells. The viral proteins hemagglutinin (HA) and neuraminidase (NA) are targeted to lipid rafts, causing the coalescence and enlargement of the raft domains. This clustering of HA and NA may cause a deformation of the membrane and the initiation of the virus budding event. M1 is then thought to bind to the cytoplasmic tails of HA and NA where it can then polymerize and form the interior structure of the emerging virion. M1, bound to the cytoplasmic tails of HA and NA, additionally serves as a docking site for the recruitment of the viral RNPs and may mediate the recruitment of M2 to the site of virus budding. M2 initially stabilizes the site of budding, possibly enabling the polymerization of the matrix protein and the formation of filamentous virions. Subsequently, M2 is able to alter membrane curvature at the neck of the budding virus, causing membrane scission and the release of the progeny virion. This review investigates the latest research on influenza virus budding in an attempt to provide a step-by-step analysis of the assembly and budding processes for influenza viruses. PMID:21237476

  13. Genetic Diversity of Toscana Virus

    PubMed Central

    Collao, Ximena; Palacios, Gustavo; Sanbonmatsu-Gámez, Sara; Pérez-Ruiz, Mercedes; Negredo, Ana I.; Navarro-Marí, José-María; Grandadam, Marc; Aransay, Ana Maria; Lipkin, W. Ian; Tenorio, Antonio

    2009-01-01

    Distribution of Toscana virus (TOSV) is evolving with climate change, and pathogenicity may be higher in nonexposed populations outside areas of current prevalence (Mediterranean Basin). To characterize genetic diversity of TOSV, we determined the coding sequences of isolates from Spain and France. TOSV is more diverse than other well-studied phleboviruses (e.g.,Rift Valley fever virus). PMID:19331735

  14. Emerging tomato viruses in Florida

    USDA-ARS?s Scientific Manuscript database

    Tomato spotted wilt virus (TSWV) causes crop losses worldwide. This tospovirus is well-known for disease epidemics in vegetable, ornamental and peanut crops in the southeastern U.S. Two other tospoviruses have recently emerged in south Florida. Groundnut ringspot virus (GRSV) was first detected in ...

  15. Oropouche Virus Isolation, Southeast Brazil

    PubMed Central

    Martins, Lívia Carício; Rodrigues, Sueli Guerreiro; Chiang, Jannifer Oliveira; Azevedo, Raimunda do Socorro da Silva; Travassos da Rosa, Amelia P.A.; Vasconcelos, Pedro Fernando da Costa

    2005-01-01

    An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama. PMID:16318707

  16. Oropouche virus isolation, southeast Brazil.

    PubMed

    Nunes, Márcio Roberto Teixeira; Martins, Lívia Carício; Rodrigues, Sueli Guerreiro; Chiang, Jannifer Oliveira; Azevedo, Raimunda do Socorro da Silva; da Rosa, Amelia P A Travassos; Vasconcelos, Pedro Fernando da Costa

    2005-10-01

    An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription-polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama.

  17. ONTOGENESIS OF HUMAN SMALLPOX VIRUS

    PubMed Central

    Avakyan, A. A.; Byckovsky, A. F.

    1965-01-01

    The vegetative stage of development of the human smallpox virus is described as being comprised of four successive periods: "without membrane" period; "open-cavity" period; "single-cavity" period; and "double-cavity" period. This classification is based on the organization of the virus membranes. This paper presents a description of the changes in virus structure during each period. It shows the strict sequence of morphological continuity and succession of differentiation of viral components. The most important stage of the development, the differentiation of virus nucleoid, takes place in the virus cavity morphologically isolated from the cellular milieu and limited originally by the external membrane of the virus and then by the second one, the primary membrane of the nucleoid. Osmiophilic fibrils 20 to 25 A wide, which fill the cavity of a mature nucleoid, become clearly evident after staining with uranyl acetate and are revealed only at the end of the last or double-cavity period. The main features of the developmental cycle of human smallpox virus may probably be characteristic of certain other groups of viruses. PMID:14326120

  18. Varicella Zoster Virus Promoter Sequences

    DTIC Science & Technology

    1994-01-01

    and genetic properties (Roizman et a1 ., 1981) . varicel l a zoster virus (VZV) is a member of the human a lphaherpesvirus s ubfami ly , wh ich...Hyman RW, Ecker JR . and Tenser RB. 1983. varicell -zoster virus RNA in human trigerminal ganglia. Lancet 2:814-816. lItis JP, Oakes JE, Hyman RW

  19. Oncolytic virus therapy for cancer

    PubMed Central

    Goldufsky, Joe; Sivendran, Shanthi; Harcharik, Sara; Pan, Michael; Bernardo, Sebastian; Stern, Richard H; Friedlander, Philip; Ruby, Carl E; Saenger, Yvonne; Kaufman, Howard L

    2013-01-01

    The use of oncolytic viruses to treat cancer is based on the selection of tropic tumor viruses or the generation of replication selective vectors that can either directly kill infected tumor cells or increase their susceptibility to cell death and apoptosis through additional exposure to radiation or chemotherapy. In addition, viral vectors can be modified to promote more potent tumor cell death, improve the toxicity profile, and/or generate host antitumor immunity. A variety of viruses have been developed as oncolytic therapeutics, including adenovirus, vaccinia virus, herpesvirus, coxsackie A virus, Newcastle disease virus, and reovirus. The clinical development of oncolytic viral therapy has accelerated in the last few years, with several vectors entering clinical trials for a variety of cancers. In this review, current strategies to optimize the therapeutic effectiveness and safety of the major oncolytic viruses are discussed, and a summary of current clinical trials is provided. Further investigation is needed to characterize better the clinical impact of oncolytic viruses, but there are increasing data demonstrating the potential promise of this approach for the treatment of human and animal cancers. PMID:27512656

  20. Groundnut Ringspot Virus in Florida

    USDA-ARS?s Scientific Manuscript database

    Tospoviruses in vegetable crops are difficult to manage due to a shortage of basic information about the viruses and their vectors. This is especially true for the recently detected Groundnut ringspot virus (GRSV). This publication presents all current knowledge of GRSV in Florida....

  1. Defining life: the virus viewpoint.

    PubMed

    Forterre, Patrick

    2010-04-01

    Are viruses alive? Until very recently, answering this question was often negative and viruses were not considered in discussions on the origin and definition of life. This situation is rapidly changing, following several discoveries that have modified our vision of viruses. It has been recognized that viruses have played (and still play) a major innovative role in the evolution of cellular organisms. New definitions of viruses have been proposed and their position in the universal tree of life is actively discussed. Viruses are no more confused with their virions, but can be viewed as complex living entities that transform the infected cell into a novel organism-the virus-producing virions. I suggest here to define life (an historical process) as the mode of existence of ribosome encoding organisms (cells) and capsid encoding organisms (viruses) and their ancestors. I propose to define an organism as an ensemble of integrated organs (molecular or cellular) producing individuals evolving through natural selection. The origin of life on our planet would correspond to the establishment of the first organism corresponding to this definition.

  2. Group 2 Vaccinia Virus, Brazil

    PubMed Central

    Assis, Felipe Lopes; Borges, Iara Apolinario; Ferreira, Paulo César Peregrino; Bonjardim, Cláudio Antônio; Trindade, Giliane de Souza; Lobato, Zélia Inês Portela; Guedes, Maria Isabel Maldonado; Mesquita, Vaz; Kroon, Erna Geessien

    2012-01-01

    In 2011, vaccinia virus caused an outbreak of bovine vaccinia, affecting dairy cattle and dairy workers in Brazil. Genetic and phenotypic analyses identified this isolate as distinct from others recently identified, thereby reinforcing the hypothesis that different vaccinia virus strains co-circulate in Brazil. PMID:23171598

  3. ICTV Virus Taxonomy Profile: Virgaviridae

    USDA-ARS?s Scientific Manuscript database

    The family Virgaviridae is comprised of plant-infecting viruses with rod-shaped particles, single stranded RNA genomes with 3' terminal tRNA-like structures, and replication proteins typical of alphalike viruses. Differences in the number of genome components, genome organization and transmission m...

  4. ICTV virus taxonomy profile: iflaviridae

    USDA-ARS?s Scientific Manuscript database

    Iflaviridae is a family of small non-enveloped viruses with RNA genomes of approximately 9-11 kilobases in length. All members infect arthropod hosts with the majority infecting insects. Beneficial and pest insects serve as hosts and infections can be symptomless (Nilaparvata lugens honeydew virus 1...

  5. Herpesvirus: an underestimated virus.

    PubMed

    Rechenchoski, Daniele Zendrini; Faccin-Galhardi, Ligia Carla; Linhares, Rosa Elisa Carvalho; Nozawa, Carlos

    2017-03-01

    Herpes simplex virus (HSV) infections are common and widespread; nevertheless, their outcome can be of unpredictable prognosis in neonates and in immunosuppressed patients. Anti-HSV therapy is effective, but the emergence of drug-resistant strains or the drug toxicity that hamper the treatment is of great concern. Vaccine has not yet shown relevant benefit; therefore, palliative prophylactic measures have been adopted to prevent diseases. This short review proposes to present concisely the history of HSV, its taxonomy, physical structure, and replication and to explore the pathogenesis of the infection, clinical manifestations, laboratory diagnosis, treatment, prophylaxis and epidemiology of the diseases.

  6. Ebola virus disease.

    PubMed

    Richardson, Kathleen J

    2015-01-01

    Ebola is an unfamiliar disease with a high mortality rate. Until recently, it occurred only in rural tropical regions and most health care providers had only read about it in epidemiology classes. With globalization, international travel, and foreign medical missions, it is possible that a patient with Ebola exposure and/or symptoms may present in any emergency department. All health care providers must be familiar with identifying the signs and symptoms of Ebola and capable of initiating an appropriate response. This article presents an overview of Ebola virus disease for health care providers, covering pathophysiology, identification, treatment, and general considerations for hospitals and providers to consider when developing policies and procedures.

  7. Canine distemper virus.

    PubMed

    Martella, Vito; Elia, Gabrielle; Buonavoglia, Canio

    2008-07-01

    Vaccine-based prophylaxis has greatly helped to keep distemper disease under control. Notwithstanding, the incidence of canine distemper virus (CDV)-related disease in canine populations throughout the world seems to have increased in the past decades, and several episodes of CDV disease in vaccinated animals have been reported, with nation-wide proportions in some cases. Increasing surveillance should be pivotal to identify new CDV variants and to understand the dynamics of CDV epidemiology. In addition, it is important to evaluate whether the efficacy of the vaccine against these new strains may somehow be affected.

  8. Other Community Respiratory Viruses.

    PubMed

    Wunderink, Richard G

    2017-03-01

    Polymerase chain reaction-based diagnosis has become the standard for viral pneumonia and other respiratory tract infections. Expansion of respiratory viral panels (RVPs) outside of influenza and, possibly, respiratory syncytial virus has led to the ability to diagnose viral infections for which no approved specific antiviral treatment exists. Careful clinical evaluation of the patient with a positive RVP is, therefore, critical given the limited repertoire of treatments. Generic treatments with intravenous immunoglobulin, ribavirin, and interferons may benefit select severe viral pneumonia patients, whereas cidofovir has activity for severe adenoviral pneumonia.

  9. Epidemic of cell phone virus

    NASA Astrophysics Data System (ADS)

    Wang, Pu; González, Marta; Barabási, Albert-László.

    2008-03-01

    Standard operating systems and Bluetooth technology will be a trend for future cell phone features. These will enable cell phone viruses to spread either through SMS or by sending Bluetooth requests when cell phones are physically close enough. The difference in spreading methods gives these two types of viruses' different epidemiological characteristics. SMS viruses' spread is mainly based on people's social connections, whereas the spreading of Bluetooth viruses is affected by people's mobility patterns and population distribution. Using cell phone data recording calls, SMS and locations of more than 6 million users, we study the spread of SMS and Bluetooth viruses and characterize how the social network and the mobility of mobile phone users affect such spreading processes.

  10. Giant viruses come of age.

    PubMed

    Fischer, Matthias G

    2016-06-01

    Viruses with genomes up to a few megabases in length are a common occurrence in nature, even though they have escaped our notice until recently. These giant viruses infect mainly single-celled eukaryotes and isolation efforts concentrating on amoebal hosts alone have spawned hundreds of viral isolates, featuring viruses with previously unseen virion morphologies and the largest known viral genomes and particles. One of the challenges that lie ahead is to analyze and categorize the available data and to establish an approved classification system that reflects the evolutionary relationships and biological properties of these viruses. Extensive sampling of Acanthamoeba-infecting mimiviruses and initial characterization of their virophage parasites have provided a first blueprint of the genetic diversity and composition of a giant virus clade that will facilitate the taxonomic grouping of these fascinating microorganisms.

  11. Biosensing with Virus Electrode Hybrids

    PubMed Central

    Mohan, Kritika; Penner, Reginald M.; Weiss, Gregory A.

    2015-01-01

    Virus electrodes address two major challenges associated with biosensing. First, the surface of the viruses can be readily tailored for specific, high affinity binding to targeted biomarkers. Second, the viruses are entrapped in a conducting polymer for electrical resistance-based, quantitative measurement of biomarker concentration. To further enhance device sensitivity, two different ligands can be attached to the virus surface, and increase the apparent affinity for the biomarker. In the example presented here, the two ligands bind to the analyte in a bidentate binding mode with chelate-based avidity effect, and result in an 100 pM experimentally observed limit of detection for the cancer biomarker prostate-specific membrane antigen. The approach does not require enzymatic amplification, and allows reagent-free, real-time measurements. This article presents general protocols for the development of such biosensors with modified viruses for the enhanced detection of arbitrary target proteins. PMID:26344233

  12. Marine Viruses: Truth or Dare

    NASA Astrophysics Data System (ADS)

    Breitbart, Mya

    2012-01-01

    Over the past two decades, marine virology has progressed from a curiosity to an intensely studied topic of critical importance to oceanography. At concentrations of approximately 10 million viruses per milliliter of surface seawater, viruses are the most abundant biological entities in the oceans. The majority of these viruses are phages (viruses that infect bacteria). Through lysing their bacterial hosts, marine phages control bacterial abundance, affect community composition, and impact global biogeochemical cycles. In addition, phages influence their hosts through selection for resistance, horizontal gene transfer, and manipulation of bacterial metabolism. Recent work has also demonstrated that marine phages are extremely diverse and can carry a variety of auxiliary metabolic genes encoding critical ecological functions. This review is structured as a scientific "truth or dare," revealing several well-established "truths" about marine viruses and presenting a few "dares" for the research community to undertake in future studies.

  13. Marine viruses: truth or dare.

    PubMed

    Breitbart, Mya

    2012-01-01

    Over the past two decades, marine virology has progressed from a curiosity to an intensely studied topic of critical importance to oceanography. At concentrations of approximately 10 million viruses per milliliter of surface seawater, viruses are the most abundant biological entities in the oceans. The majority of these viruses are phages (viruses that infect bacteria). Through lysing their bacterial hosts, marine phages control bacterial abundance, affect community composition, and impact global biogeochemical cycles. In addition, phages influence their hosts through selection for resistance, horizontal gene transfer, and manipulation of bacterial metabolism. Recent work has also demonstrated that marine phages are extremely diverse and can carry a variety of auxiliary metabolic genes encoding critical ecological functions. This review is structured as a scientific "truth or dare," revealing several well-established "truths" about marine viruses and presenting a few "dares" for the research community to undertake in future studies.

  14. Movement of Viruses between Biomes

    PubMed Central

    Sano, Emiko; Carlson, Suzanne; Wegley, Linda; Rohwer, Forest

    2004-01-01

    Viruses are abundant in all known ecosystems. In the present study, we tested the possibility that viruses from one biome can successfully propagate in another. Viral concentrates were prepared from different near-shore marine sites, lake water, marine sediments, and soil. The concentrates were added to microcosms containing dissolved organic matter as a food source (after filtration to allow 100-kDa particles to pass through) and a 3% (vol/vol) microbial inoculum from a marine water sample (after filtration through a 0.45-μm-pore-size filter). Virus-like particle abundances were then monitored using direct counting. Viral populations from lake water, marine sediments, and soil were able to replicate when they were incubated with the marine microbes, showing that viruses can move between different ecosystems and propagate. These results imply that viruses can laterally transfer DNA between microbes in different biomes. PMID:15466522

  15. Zika Virus Induced Cellular Remodeling.

    PubMed

    Rossignol, Evan D; Peters, Kristen N; Connor, John H; Bullitt, Esther

    2017-03-20

    Zika virus (ZIKV) has been associated with morbidities such as Guillain-Barré, infant microcephaly, and ocular disease. The spread of this positive-sense, single-stranded RNA virus and its growing public health threat underscore gaps in our understanding of basic ZIKV virology. To advance knowledge of the virus replication cycle within mammalian cells, we use serial section three-dimensional electron tomography to demonstrate the widespread remodeling of intracellular membranes upon infection with ZIKV. We report extensive structural rearrangements of the endoplasmic reticulum and reveal stages of the ZIKV viral replication cycle. Structures associated with RNA genome replication and virus assembly are observed integrated within the endoplasmic reticulum, and we show viruses in transit through the Golgi apparatus for viral maturation, and subsequent cellular egress. This study characterizes in detail the three-dimensional ultrastructural organization of the ZIKV replication cycle stages. Our results show close adherence of the ZIKV replication cycle to the existing flavivirus replication paradigm.

  16. New aspects of influenza viruses.

    PubMed Central

    Shaw, M W; Arden, N H; Maassab, H F

    1992-01-01

    Influenza virus infections continue to cause substantial morbidity and mortality with a worldwide social and economic impact. The past five years have seen dramatic advances in our understanding of viral replication, evolution, and antigenic variation. Genetic analyses have clarified relationships between human and animal influenza virus strains, demonstrating the potential for the appearance of new pandemic reassortants as hemagglutinin and neuraminidase genes are exchanged in an intermediate host. Clinical trials of candidate live attenuated influenza virus vaccines have shown the cold-adapted reassortants to be a promising alternative to the currently available inactivated virus preparations. Modern molecular techniques have allowed serious consideration of new approaches to the development of antiviral agents and vaccines as the functions of the viral genes and proteins are further elucidated. The development of techniques whereby the genes of influenza viruses can be specifically altered to investigate those functions will undoubtedly accelerate the pace at which our knowledge expands. PMID:1310439

  17. Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial

    PubMed Central

    2014-01-01

    Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of

  18. Virus manipulation of cell cycle.

    PubMed

    Nascimento, R; Costa, H; Parkhouse, R M E

    2012-07-01

    Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways.

  19. Viruses of commercialized insect pollinators.

    PubMed

    Gisder, Sebastian; Genersch, Elke

    2017-07-01

    Managed insect pollinators are indispensable in modern agriculture. They are used worldwide not only in the open field but also in greenhouses to enhance fruit set, seed production, and crop yield. Managed honey bee (Apis mellifera, Apis cerana) colonies provide the majority of commercial pollination although other members of the superfamily Apoidea are also exploited and commercialized as managed pollinators. In the recent past, it became more and more evident that viral diseases play a key role in devastating honey bee colony losses and it was also recognized that many viruses originally thought to be honey bee specific can also be detected in other pollinating insects. However, while research on viruses infecting honey bees started more than 50years ago and the knowledge on these viruses is growing ever since, little is known on virus diseases of other pollinating bee species. Recent virus surveys suggested that many of the viruses thought to be honey bee specific are actually circulating in the pollinator community and that pollinator management and commercialization of pollinators provide ample opportunity for viral diseases to spread. However, the direction of disease transmission is not always clear and the impact of these viral diseases on the different hosts remains elusive in many cases. With our review we want to provide an up-to-date overview on the viruses detected in different commercialized pollinators in order to encourage research in the field of pollinator virology that goes beyond molecular detection of viruses. A deeper understanding of this field of virology is urgently needed to be able to evaluate the impact of viruses on pollinator health and the role of different pollinators in spreading viral diseases and to be able to decide on appropriate measures to prevent virus-driven pollinator decline. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Hanta virus infection during dengue virus infection outbreak in Indonesia.

    PubMed

    Suharti, Catharina; van Gorp, Eric C M; Dolmans, Wil M V; Groen, Jan; Hadisaputro, Suharyo; Djokomoeljanto, Robert J; D M E, Osterhaus Ab; van der Meer, Jos W M

    2009-04-01

    To investigate which recent infection could have caused the present dengue-like symptoms, in adult patients clinically fulfilling the WHO criteria for dengue, in which serologically were not confirmed for dengue virus infections. Prospective study. During an outbreak of dengue (between May 1995 and May 1996) 118 consecutive adults (>13 years) suspected by the WHO 1997 case definition of DF or DHF were investigated. Patients were examined for history of illness, physical and laboratory findings consisting of full blood counts, prothrombin time (PT), activated partial thromboplastin time (aPTT), liver function (bilirubin, ASAT, ALAT), renal function (creatinine), and serological assays included dengue, hantavirus, chikungunya, R. typhi, R. tsutsugamuchi, rubella virus, influenza A virus, and leptospira. In 58 of the total 118 patients, recent dengue virus infection was serologically confirmed. In 20 of the remaining 60 patients, we found serological evidence of another recent infection: hantavirus (5), chikungunya virus (2), R. typhi (5), R. tsutsugamuchi (2), rubella virus (3), influenza A virus (1), and leptospira (2). No evidence for recent infection with any of the mentioned agents was detected in the remaining 40 specimens. We conclude that based on clinical characteristics alone, it is not easy to diagnose dengue. Specific laboratory tests to differentiate dengue from other febrile illnesses are needed. Among these, in Indonesia hantavirus infection should be considered as well.

  1. Hepatitis E Virus and Related Viruses in Animals.

    PubMed

    Thiry, D; Mauroy, A; Pavio, N; Purdy, M A; Rose, N; Thiry, E; de Oliveira-Filho, E F

    2017-02-01

    Hepatitis E is an acute human liver disease in healthy individuals which may eventually become chronic. It is caused by the hepatitis E virus (HEV) and can have a zoonotic origin. Nearly 57,000 people die yearly from hepatitis E-related conditions. The disease is endemic in both developing and developed countries with distinct epidemiologic profiles. In developing countries, the disease is associated with inadequate water treatment, while in developed countries, transmission is associated with animal contact and the ingestion of raw or uncooked meat, especially liver. All human HEV are grouped into at least four genotypes, while HEV or HEV-related viruses have been identified in an increasing number of domestic and wild animal species. Despite a high genetic diversity, only one single HEV serotype has been described to date for HEV genotypes 1-4. The discovery of new HEV or HEV-related viruses leads to a continuing increase in the number of genotypes. In addition, the genome organization of all these viruses is variable with overlapping open reading frames (ORF) and differences in the location of ORF3. In spite of the role of some domestic and wild animals as reservoir, the origin of HEV and HEV-related viruses in humans and animals is still unclear. This review discusses aspects of the detection, molecular virology, zoonotic transmission and origin of HEV and HEV-related viruses in the context of 'One Health' and establishes a link between the previous and the new taxonomy of this growing virus family.

  2. [Helper viruses of adeno-associated virus type 4 replication].

    PubMed

    Dreĭzin, R S; Zhuravel', T F; Shalunova, N V; Klenova, A V; Zolotarskaia, E E

    1979-01-01

    In replication of adeno-associated virus type 4 (AAV-4) the helper function may be performed by a non-defective virus from the same group of parvoviruses (Kilham virus). The synthesis of AAV-4 antigen was observed in a pig embryo kidney cell line, SPEV, chronically infected with Kilham virus, strain RV-13, 45--52 passages. A one-day-old SPEV-Kilham culture was infected with AAV-4. The AAV-4 antigen was detected by immunofluorescence at 6, 8, 12, 18 hours, 2, 3, 4, and 5 days after inoculation. During the first 2--4 days after inoculation the AAV-4 antigen was found in the nucleus and perinuclear zone, later in the cytoplasm. A "new" helper virus for AAV-4 replication has been found: simiancytomegalovirus in human embryo fibroblast cell culture permissive for the helper virus. In the systems where AAV-4 replicates, its antigen can be detected in the nucleus and perinuclear zone by IF. AAV-4 did not replicate in a system insensitive to the helper virus or under non-permissive conditions: at the time, the AAV-4 antigen localized only in the cell cytoplasm was detected.

  3. Antivirals against animal viruses.

    PubMed

    Villa, T G; Feijoo-Siota, L; Rama, J L R; Ageitos, J M

    2016-09-30

    Antivirals are compounds used since the 1960s that can interfere with viral development. Some of these antivirals can be isolated from a variety of sources, such as animals, plants, bacteria or fungi, while others must be obtained by chemical synthesis, either designed or random. Antivirals display a variety of mechanisms of action, and while some of them enhance the animal immune system, others block a specific enzyme or a particular step in the viral replication cycle. As viruses are mandatory intracellular parasites that use the host's cellular machinery to survive and multiply, it is essential that antivirals do not harm the host. In addition, viruses are continually developing new antiviral resistant strains, due to their high mutation rate, which makes it mandatory to continually search for, or develop, new antiviral compounds. This review describes natural and synthetic antivirals in chronological order, with an emphasis on natural compounds, even when their mechanisms of action are not completely understood, that could serve as the basis for future development of novel and/or complementary antiviral treatments.

  4. Dengue virus vaccine development.

    PubMed

    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches.

  5. APOBECs and Virus Restriction

    PubMed Central

    Harris, Reuben S.; Dudley, Jaquelin P.

    2015-01-01

    The APOBEC family of single-stranded DNA cytosine deaminases comprises a formidable arm of the vertebrate innate immune system. Pre-vertebrates express a single APOBEC, whereas some mammals produce as many as eleven enzymes. The APOBEC3 subfamily displays both copy number variation and polymorphisms, consistent with ongoing pathogenic pressures. These enzymes restrict the replication of many DNA-based parasites, such as exogenous viruses and endogenous transposable elements. APOBEC1 and activation-induced cytosine deaminase (AID) have specialized functions in RNA editing and antibody gene diversification, respectively, whereas APOBEC2 and APOBEC4 appear to have different functions. Nevertheless, the APOBEC family protects against both periodic viral zoonoses as well as exogenous and endogenous parasite replication. This review highlights viral pathogens that are restricted by APOBEC enzymes, but manage to escape through unique mechanisms. The sensitivity of viruses that lack counterdefense measures highlights the need to develop APOBEC-enabling small molecules as a new class of anti-viral drugs. PMID:25818029

  6. [Resistance in influenza viruses].

    PubMed

    Hungnes, Olav; Dudman, Susanne Gjeruldsen

    2008-11-20

    Influenza virus infection can be prevented and treated with antiviral drugs. The usage of such drugs in Norway has been infrequent, however, they are an important component in our pandemic preparedness planning, as it will probably be difficult to get access to the appropriate vaccine in time before the pandemic reaches the country. The first generation of influenza drugs acquired resistance to a large degree, in contrast to the modern neuraminidase inhibitors that until recently have had minor problems with resistance. This review is based on research found in relevant published literature, together with experience from a virology reference laboratory and participation in a national and international surveillance including susceptibility testing. While resistance has been a longstanding problem with the use of the "old" influenza drugs amantadine and rimantadine, only during the winter 2007/2008 did it become clear, that a certain type of virus acquired widespread resistance against the neuraminidase inhibitor oseltamivir. Resistance surveillance is crucial for the correct choice of empiric treatment for influenza infection, and will be one of the most important tasks at the National Influenza Centre in certain phases of a pandemic. The current situation with an increasing resistance problem strengthens the need to conduct continuous monitoring of antiviral susceptibility, as well as development of new antiviral drugs and treatment regimes.

  7. Hepatitis E Virus Infection

    PubMed Central

    Dalton, Harry R.; Abravanel, Florence; Izopet, Jacques

    2014-01-01

    SUMMARY Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries. PMID:24396139

  8. A single vertebrate DNA virus protein disarms invertebrate immunity to RNA virus infection

    USDA-ARS?s Scientific Manuscript database

    Virus-host interactions drive a remarkable diversity of immune responses and countermeasures. While investigating virus-invertebrate host interactions we found that two RNA viruses with broad host ranges, vesicular stomatitis virus (VSV) and Sindbis virus (SINV), were unable to infect certain Lepido...

  9. Infectious vaccinia virus recombinants that express hepatitis B virus surface antigen

    NASA Astrophysics Data System (ADS)

    Smith, Geoffrey L.; Mackett, Michael; Moss, Bernard

    1983-04-01

    Potential live vaccines against hepatitis B virus have been produced. The coding sequence for hepatitis B virus surface antigen (HBsAg) has been inserted into the vaccinia virus genome under control of vaccinia virus early promoters. Cells infected with these vaccinia virus recombinants synthesize and excrete HBsAg and vaccinated rabbits rapidly produce antibodies to HBsAg.

  10. 9 CFR 113.215 - Bovine Virus Diarrhea Vaccine, Killed Virus.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Bovine Virus Diarrhea Vaccine, Killed Virus. 113.215 Section 113.215 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Vaccine, Killed Virus, shall be prepared from virus-bearing cell culture fluids. Only Master Seed virus...

  11. 9 CFR 113.215 - Bovine Virus Diarrhea Vaccine, Killed Virus.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Bovine Virus Diarrhea Vaccine, Killed Virus. 113.215 Section 113.215 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Vaccine, Killed Virus, shall be prepared from virus-bearing cell culture fluids. Only Master Seed virus...

  12. Viruses in the Oceanic Basement.

    PubMed

    Nigro, Olivia D; Jungbluth, Sean P; Lin, Huei-Ting; Hsieh, Chih-Chiang; Miranda, Jaclyn A; Schvarcz, Christopher R; Rappé, Michael S; Steward, Grieg F

    2017-03-07

    Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement), but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C) were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B) drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 10(5) to 2 × 10(5) ml(-1) (n = 8), higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27). Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%). Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR)-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737), 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome.IMPORTANCE The hydrothermally active ocean basement is voluminous and likely provided conditions critical to the origins of life, but the microbiology of this vast habitat is not

  13. Genome Sequences of Beet curly top Iran virus, Oat dwarf virus, Turnip curly top virus, and Wheat dwarf virus Identified in Leafhoppers

    PubMed Central

    Kamali, Mehdi; Pouramini, Najmeh; Masumi, Hossain; Farkas, Kata; Kraberger, Simona

    2017-01-01

    ABSTRACT Implementation of a vector-enabled metagenomics approach resulted in the identification of various geminiviruses. We identified the genome sequences of Beet curly top Iran virus, Turnip curly top viruses, Oat dwarf viruses, the first from Iran, and Wheat dwarf virus from leafhoppers feeding on beet, parsley, pumpkin, and turnip plants. PMID:28232449

  14. Safe Computing: An Overview of Viruses.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2001-01-01

    A computer virus is a program that replicates itself, in conjunction with an additional program that can harm a computer system. Common viruses include boot-sector, macro, companion, overwriting, and multipartite. Viruses can be fast, slow, stealthy, and polymorphic. Anti-virus products are described. (MLH)

  15. The Epstein-Barr virus: Recent advances

    SciTech Connect

    Epstein, M.A.; Achong, B.G.

    1986-01-01

    This book contains 11 chapters. Some of the titles are: Failure in Immunological Control of the Virus Infection: Post-Transplant Lymphomas; Cellular Immunological Responses to the Virus Infection; Characterization of the Virus-Determined Antigens; and the Virus Genome and its Expression in Latent Infection.

  16. Zika Virus and Complications: Questions and Answers

    MedlinePlus

    ... WHO Language عربي 中文 English Français Русский Español Zika virus and complications: Questions and answers Online Q& ... mosquitoes are present that can transmit the virus. Zika virus How do people catch Zika virus? Zika ...

  17. [Overview on duck virus hepatitis A].

    PubMed

    Ren, Liqian; Li, Jing; Bi, Yuhai; Chen, Can; Zhang, Dabing; Liu, Wenjun

    2012-07-01

    This article describes the nomenclature, history and genetic evolution of duck hepatitis A virus, and updates the epidemiology, clinical symptom and surveillances of duck virus hepatitis A. It also summarizes the present status and progress of duck virus hepatitis A and illustrated the necessity and urgency of its research, which provides rationale for the control of duck hepatitis A virus disease in China.

  18. Safe Computing: An Overview of Viruses.

    ERIC Educational Resources Information Center

    Wodarz, Nan

    2001-01-01

    A computer virus is a program that replicates itself, in conjunction with an additional program that can harm a computer system. Common viruses include boot-sector, macro, companion, overwriting, and multipartite. Viruses can be fast, slow, stealthy, and polymorphic. Anti-virus products are described. (MLH)

  19. Ebola Virus Antibodies in Fruit Bats, Bangladesh

    PubMed Central

    Islam, Ariful; Yu, Meng; Anthony, Simon J.; Epstein, Jonathan H.; Khan, Shahneaz Ali; Khan, Salah Uddin; Crameri, Gary; Wang, Lin-Fa; Lipkin, W. Ian; Luby, Stephen P.; Daszak, Peter

    2013-01-01

    To determine geographic range for Ebola virus, we tested 276 bats in Bangladesh. Five (3.5%) bats were positive for antibodies against Ebola Zaire and Reston viruses; no virus was detected by PCR. These bats might be a reservoir for Ebola or Ebola-like viruses, and extend the range of filoviruses to mainland Asia. PMID:23343532

  20. Genome Sequences of Beet curly top Iran virus, Oat dwarf virus, Turnip curly top virus, and Wheat dwarf virus Identified in Leafhoppers.

    PubMed

    Kamali, Mehdi; Heydarnejad, Jahangir; Pouramini, Najmeh; Masumi, Hossain; Farkas, Kata; Kraberger, Simona; Varsani, Arvind

    2017-02-23

    Implementation of a vector-enabled metagenomics approach resulted in the identification of various geminiviruses. We identified the genome sequences of Beet curly top Iran virus, Turnip curly top viruses, Oat dwarf viruses, the first from Iran, and Wheat dwarf virus from leafhoppers feeding on beet, parsley, pumpkin, and turnip plants.

  1. Nosocomial viral infections: III. Guidelines for prevention and control of exanthematous viruses, gastroenteritis viruses, picornaviruses, and uncommonly seen viruses.

    PubMed

    Valenti, W M; Hruska, J F; Menegus, M A; Freeburn, M J

    1981-01-01

    This communication is the third in a four-part series on nosocomial viral infections from the Strong Memorial Hospital. This third article discusses guidelines for prevention and control of exanthematous viruses, gastroenteritis, viruses, adenoviruses and the picornaviruses other than rhinoviruses. Several uncommonly seen viruses, such as the virus of Creutzfeldt-Jakob disease and Marburg, Ebola, and Lassa fever viruses, also are reviewed briefly.

  2. Transmitting plant viruses using whiteflies.

    PubMed

    Polston, Jane E; Capobianco, H

    2013-11-08

    Whiteflies, Hemiptera: Aleyrodidae, Bemisia tabaci, a complex of morphologically indistinquishable species(5), are vectors of many plant viruses. Several genera of these whitefly-transmitted plant viruses (Begomovirus, Carlavirus, Crinivirus, Ipomovirus, Torradovirus) include several hundred species of emerging and economically significant pathogens of important food and fiber crops (reviewed by(9,10,16)). These viruses do not replicate in their vector but nevertheless are moved readily from plant to plant by the adult whitefly by various means (reviewed by(2,6,7,9,10,11,17)). For most of these viruses whitefly feeding is required for acquisition and inoculation, while for others only probing is required. Many of these viruses are unable or cannot be easily transmitted by other means. Therefore maintenance of virus cultures, biological and molecular characterization (identification of host range and symptoms)(3,13), ecology(2,12), require that the viruses be transmitted to experimental hosts using the whitefly vector. In addition the development of new approaches to management, such as evaluation of new chemicals(14) or compounds(15), new cultural approaches(1,4,19), or the selection and development of resistant cultivars(7,8,18), requires the use of whiteflies for virus transmission. The use of whitefly transmission of plant viruses for the selection and development of resistant cultivars in breeding programs is particularly challenging(7). Effective selection and screening for resistance employs large numbers of plants and there is a need for 100% of the plants to be inoculated in order to find the few genotypes which possess resistance genes. These studies use very large numbers of viruliferous whiteflies, often several times per year. Whitefly maintenance described here can generate hundreds or thousands of adult whiteflies on plants each week, year round, without the contamination of other plant viruses. Plants free of both whiteflies and virus must be

  3. Plant virus replication and movement.

    PubMed

    Heinlein, Manfred

    2015-05-01

    Replication and intercellular spread of viruses depend on host mechanisms supporting the formation, transport and turnover of functional complexes between viral genomes, virus-encoded products and cellular factors. To enhance these processes, viruses assemble and replicate in membrane-associated complexes that may develop into "virus factories" or "viroplasms" in which viral components and host factors required for replication are concentrated. Many plant viruses replicate in association with the cortical ER-actin network that is continuous between cells through plasmodesmata. The replication complexes can be highly organized and supported by network interactions between the viral genome and the virus-encoded proteins. Intracellular PD targeting of replication complexes links the process of movement to replication and provides specificity for transport of the viral genome by the virus-encoded movement proteins. The formation and trafficking of replication complexes and also the development and anchorage of replication factories involves important roles of the cortical cytoskeleton and associated motor proteins. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Viruses and interactomes in translation.

    PubMed

    Meyniel-Schicklin, Laurène; de Chassey, Benoît; André, Patrice; Lotteau, Vincent

    2012-07-01

    A decade of high-throughput screenings for intraviral and virus-host protein-protein interactions led to the accumulation of data and to the development of theories on laws governing interactome organization for many viruses. We present here a computational analysis of intraviral protein networks (EBV, FLUAV, HCV, HSV-1, KSHV, SARS-CoV, VACV, and VZV) and virus-host protein networks (DENV, EBV, FLUAV, HCV, and VACV) from up-to-date interaction data, using various mathematical approaches. If intraviral networks seem to behave similarly, they are clearly different from the human interactome. Viral proteins target highly central human proteins, which are precisely the Achilles' heel of the human interactome. The intrinsic structural disorder is a distinctive feature of viral hubs in virus-host interactomes. Overlaps between virus-host data sets identify a core of human proteins involved in the cellular response to viral infection and in the viral capacity to hijack the cell machinery for viral replication. Host proteins that are strongly targeted by a virus seem to be particularly attractive for other viruses. Such protein-protein interaction networks and their analysis represent a powerful resource from a therapeutic perspective.

  5. Viruses in the Oceanic Basement

    PubMed Central

    Jungbluth, Sean P.; Lin, Huei-Ting; Hsieh, Chih-Chiang; Miranda, Jaclyn A.; Schvarcz, Christopher R.; Rappé, Michael S.

    2017-01-01

    ABSTRACT Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement), but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C) were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B) drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 105 to 2 × 105 ml−1 (n = 8), higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27). Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%). Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR)-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737), 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome. PMID:28270584

  6. Effectiveness evaluation of Contra Caries Oral Health Education Program for improving Spanish-speaking parents' preventive oral health knowledge and behaviors for their young children.

    PubMed

    Hoeft, K S; Barker, J C; Shiboski, S; Pantoja-Guzman, E; Hiatt, R A

    2016-12-01

    To determine the effectiveness of the Contra Caries Oral Health Education Program (CCOHEP) for improving low-income, Spanish-speaking parents' oral health knowledge and behaviors for their young children. Mexican American children in the United States suffer disproportionately high prevalence and severity of early childhood caries, yet few evaluated, theory-based behavioral interventions exist for this population. CCOHEP is a theory-based curriculum consisting of four 2-h interactive classes designed for and by Spanish speakers and led by designated community health educators (promotoras). Topics included children's oral hygiene, caries etiology, dental procedures, nutrition, child behavior management, and parent skill-building activities. Low-income Spanish-speaking parents/caregivers of children aged 0-5 years were recruited through community services in an agricultural city in California. Survey questions from the Oral Health Basic Research Facts Questionnaire measuring oral health-related behaviors and knowledge were verbally administered before, immediately after, and 3 months after attendance at CCOHEP. Five questions measured aspects of parental toothbrushing for their children (frequency, using fluoridated toothpaste, brushing before bed, not drinking or eating after nighttime brushing, adult assistance), three questions measured other oral health behaviors, and 16 questions measured oral health-related knowledge. Analyses of within-person changes between pre- and post-tests and again between post-test and 3-month follow-up consisted of McNemar's test for binary outcomes and sign tests for ordinal outcomes. Overall, 105 caregivers participated in CCOHEP (n = 105 pretest, n = 95 post-test, n = 79 second post-test). At baseline, all parents self-reported doing at least one aspect of toothbrushing correctly, but only 13% reported performing all five aspects according to professional guidelines. At post-test, 44% of parents reported completing all aspects of

  7. Marburg Virus Reverse Genetics Systems.

    PubMed

    Schmidt, Kristina Maria; Mühlberger, Elke

    2016-06-22

    The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family and belongs to the group of nonsegmented negative-strand RNA viruses. Reverse genetics systems established for MARV have been used to study various aspects of the viral replication cycle, analyze host responses, image viral infection, and screen for antivirals. This article provides an overview of the currently established MARV reverse genetic systems based on minigenomes, infectious virus-like particles and full-length clones, and the research that has been conducted using these systems.

  8. ICTV Virus Taxonomy Profile: Circoviridae.

    PubMed

    Breitbart, Mya; Delwart, Eric; Rosario, Karyna; Segalés, Joaquim; Varsani, Arvind; Ictv Report Consortium

    2017-08-01

    The family Circoviridae comprises viruses with small, circular, single-stranded DNA (ssDNA) genomes, including the smallest known animal viruses. Members of this family are classified into two genera, Circovirus and Cyclovirus, which are distinguished by the position of the origin of replication relative to the coding regions and the length of the intergenic regions. Within each genus, the species demarcation threshold is 80 % genome-wide nucleotide sequence identity. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Circoviridae, which is available at www.ictv.global/report/circoviridae.

  9. Virulence Markers of Dengue Viruses

    DTIC Science & Technology

    1988-06-10

    AD VIRULENCE MARKERS OF DENGUE VIRUSES 00 ANNUAL REPORT 0 James L. Hardy and Srisakul C. Kliks June 10, 1988 Supported by U.S. ARMY MEDICAL RESEARCH...Virulence Markers of Dengue Viruses (U) 12. PERSONAL AUTHOR(S) James L. Hardy ind Sriqakul.C. Klik,,q 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF...TERMS (Continue on reverse it necessary and identify by block number) FIELD GROUP SUB-GROUP Dengue viruses, dengue hemorrhagic fever, virulence, U3

  10. Marburg Virus Reverse Genetics Systems

    PubMed Central

    Schmidt, Kristina Maria; Mühlberger, Elke

    2016-01-01

    The highly pathogenic Marburg virus (MARV) is a member of the Filoviridae family and belongs to the group of nonsegmented negative-strand RNA viruses. Reverse genetics systems established for MARV have been used to study various aspects of the viral replication cycle, analyze host responses, image viral infection, and screen for antivirals. This article provides an overview of the currently established MARV reverse genetic systems based on minigenomes, infectious virus-like particles and full-length clones, and the research that has been conducted using these systems. PMID:27338448

  11. "The evil virus cell": Students‘ knowledge and beliefs about viruses

    PubMed Central

    Enzinger, Sonja M.; Fink, Andreas

    2017-01-01

    Education about virus biology at school is of pivotal interest to raise public awareness concerning means of disease transmission and, thus, methods to prevent infection, and to reduce unnecessary antibiotic treatment due to patient pressure on physicians in case of viral diseases such as influenza. This study aimed at making visible the knowledge of Austrian high school and university students with respect to virus biology, virus structure and health-education issues. The data presented here stem from comprehensive questionnaire analyses, including the task to draw a virus, from a cross-sectional study with 133 grade 7 and 199 grade 10 high school students, and 133 first-year biology and 181 first-year non-biology university students. Analyses were performed both quantitatively and qualitatively. ANOVA revealed a highly significant group effect for total knowledge relating to virus biology and health issues (F(3, 642) = 44.17, p < 0.01, η2p = 0.17). Specific post-hoc tests by means of the Tukey test showed significant differences between all groups (p < .01) with the exception of 1st year non-biology students and grade 10 high school students. Students enrolled in university-level biology outperformed all other groups, even though they had not yet encountered this topic at their courses; part of this phenomenon might be due to their affinity for learning about biological topics. However, even many first-year biology students had a high number of severe misconceptions, e.g., defining a virus as a pro- or eukaryotic cell, or falsely naming malaria as a viral disease. Since there was no significant difference in virus-related knowledge between high schools, virus biology seems to have been taught similarly among the tested schools. However, the majority of participants stated that the virus-related knowledge they had acquired at school was not sufficient. Based on the results presented here we urgently suggest improving and intensifying teaching this topic at school

  12. "The evil virus cell": Students' knowledge and beliefs about viruses.

    PubMed

    Simon, Uwe K; Enzinger, Sonja M; Fink, Andreas

    2017-01-01

    Education about virus biology at school is of pivotal interest to raise public awareness concerning means of disease transmission and, thus, methods to prevent infection, and to reduce unnecessary antibiotic treatment due to patient pressure on physicians in case of viral diseases such as influenza. This study aimed at making visible the knowledge of Austrian high school and university students with respect to virus biology, virus structure and health-education issues. The data presented here stem from comprehensive questionnaire analyses, including the task to draw a virus, from a cross-sectional study with 133 grade 7 and 199 grade 10 high school students, and 133 first-year biology and 181 first-year non-biology university students. Analyses were performed both quantitatively and qualitatively. ANOVA revealed a highly significant group effect for total knowledge relating to virus biology and health issues (F(3, 642) = 44.17, p < 0.01, η2p = 0.17). Specific post-hoc tests by means of the Tukey test showed significant differences between all groups (p < .01) with the exception of 1st year non-biology students and grade 10 high school students. Students enrolled in university-level biology outperformed all other groups, even though they had not yet encountered this topic at their courses; part of this phenomenon might be due to their affinity for learning about biological topics. However, even many first-year biology students had a high number of severe misconceptions, e.g., defining a virus as a pro- or eukaryotic cell, or falsely naming malaria as a viral disease. Since there was no significant difference in virus-related knowledge between high schools, virus biology seems to have been taught similarly among the tested schools. However, the majority of participants stated that the virus-related knowledge they had acquired at school was not sufficient. Based on the results presented here we urgently suggest improving and intensifying teaching this topic at school

  13. Antiviral Drugs for Viruses Other Than Human Immunodeficiency Virus

    PubMed Central

    Razonable, Raymund R.

    2011-01-01

    Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M2 protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti–human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M2 inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects. PMID

  14. Antiviral drugs for viruses other than human immunodeficiency virus.

    PubMed

    Razonable, Raymund R

    2011-10-01

    Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

  15. Decreased egg production in turkeys experimentally infected with eastern equine encephalitis virus or Highlands J virus.

    PubMed

    Guy, J S; Barnes, H J; Ficken, M D; Smith, L G; Emory, W H; Wages, D P

    1994-01-01

    Turkey breeder hens were experimentally infected with strains of eastern equine encephalitis (EEE) virus or Highlands J (HJ) virus previously isolated from turkey hens experiencing decreased egg production. Depression and inappetance were observed on day 1 postexposure (PE) in hens inoculated with either EEE virus or HJ virus, and egg production fell in each virus-inoculated group from approximately 75% to less than 20% within 2-3 days PE. Egg production remained depressed (less than 20%) for 15 days in EEE-virus-inoculated hens and for 7 days in HJ-virus-inoculated hens. EEE virus and HJ virus were recovered from various tissues on days 1-5 PE, and virus was detected in eggs laid on days 2-5 PE. The findings of this study confirm that EEE virus and HJ virus are potential causes of decreased egg production in turkey breeder hens.

  16. [Hepatitis E virus].

    PubMed

    Izopet, Jacques; Lhomme, Sébastien; Abravanel, Florence; Roque, Anne-Marie; Kamar, Nassim

    2015-03-01

    HEV is a small non-enveloped RNA virus that is associated to lipids in the blood of infected individuals. The genera Orthohepevirus recently proposed includes the zoonotic mammals strains. The other strains of the family Hepeviridae are not transmissible to humans. The diagnosis of HEV infection should be considered in any patient with serum ALT elevation. The diagnosis of HEV infection in immunocompetent patients relies on detecting IgM antibodies in the blood. The diagnosis of HEV infection in immunosuppressed patients relies on detecting IgM antibodies and HEV RNA in the blood. Ribavirin inhibits HEV replication via a mechanism of action that is still unknown. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  17. Junin virus structural proteins.

    PubMed Central

    De Martínez Segovia, Z M; De Mitri, M I

    1977-01-01

    Polyacrylamide gel electrophoresis of purified Junin virus revealed six distinct structural polypeptides, two major and four minor ones. Four of these polypeptides appeared to be covalently linked with carbohydrate. The molecular weights of the six proteins, estimated by coelectrophoresis with marker proteins, ranged from 25,000 to 91,000. One of the two major components (number 3) was identified as a nucleoprotein and had a molecular weight of 64,000. It was the most prominent protein and was nonglycosylated. The other major protein (number 5), with a molecular weight of 38,000, was a glucoprotein and a component of the viral envelope. The location on the virion of three additional glycopeptides with molecular weights of 91,000, 72,000, and 52,000, together with a protein with a molecular weight of 25,000, was not well defined. PMID:189088

  18. Feline immunodeficiency virus latency

    PubMed Central

    2013-01-01

    Despite highly effective anti-retroviral therapy, HIV is thought to persist in patients within long-lived cellular reservoirs in the form of a transcriptionally inactive (latent) integrated provirus. Lentiviral latency has therefore come to the forefront of the discussion on the possibility of a cure for HIV infection in humans. Animal models of lentiviral latency provide an essential tool to study mechanisms of latency and therapeutic manipulation. Of the three animal models that have been described, the feline immunodeficiency virus (FIV)-infected cat is the most recent and least characterized. However, several aspects of this model make it attractive for latency research, and it may be complementary to other model systems. This article reviews what is known about FIV latency and chronic FIV infection and how it compares with that of other lentiviruses. It thereby offers a framework for the usefulness of this model in future research aimed at lentiviral eradication. PMID:23829177

  19. Zika Virus and Eye.

    PubMed

    Agrawal, Rupesh; Oo, Hnin Hnin; Balne, Praveen Kumar; Ng, Lisa; Tong, Louis; Leo, Yee Sin

    2017-03-20

    Zika virus (ZIKV), a mosquito-borne flavivirus, is the latest global health concern. Transmission is mainly via Aedes mosquitoes and the infection can be diagnosed on molecular or serologic testings. It typically causes a mild self-remitting illness of low-grade fever, maculopapular rash, and myalgia, but when severe, it is associated with neurological deficits and congenital structural defects. Ocular manifestations are usually mild like nonpurulent conjunctivitis in adults, though it may be linked to uveitis, maculopathy, and hypertensive iridocyclitis. Ocular signs seem to be more significant in congenital ZIKV-macular pigment mottling, neuroretinal atrophy with macular involvement, iris coloboma, and changes in retinal vasculature are noted in infants with infected mothers. Risk factors include ZIKV infection in first trimester and smaller cephalic diameter at birth. Hence, ophthalmic examination in newborns is now recommended. Currently, prevention and active surveillance are integral as there is no known vaccine, and treatment is only symptomatic.

  20. Genomic exploration of individual giant ocean viruses.

    PubMed

    Wilson, William H; Gilg, Ilana C; Moniruzzaman, Mohammad; Field, Erin K; Koren, Sergey; LeCleir, Gary R; Martínez Martínez, Joaquín; Poulton, Nicole J; Swan, Brandon K; Stepanauskas, Ramunas; Wilhelm, Steven W

    2017-08-01

    Viruses are major pathogens in all biological systems. Virus propagation and downstream analysis remains a challenge, particularly in the ocean where the majority of their microbial hosts remain recalcitrant to current culturing techniques. We used a cultivation-independent approach to isolate and sequence individual viruses. The protocol uses high-speed fluorescence-activated virus sorting flow cytometry, multiple displacement amplification (MDA), and downstream genomic sequencing. We focused on 'giant viruses' that are readily distinguishable by flow cytometry. From a single-milliliter sample of seawater collected from off the dock at Boothbay Harbor, ME, USA, we sorted almost 700 single virus particles, and subsequently focused on a detailed genome analysis of 12. A wide diversity of viruses was identified that included Iridoviridae, extended Mimiviridae and even a taxonomically novel (unresolved) giant virus. We discovered a viral metacaspase homolog in one of our sorted virus particles and discussed its implications in rewiring host metabolism to enhance infection. In addition, we demonstrated that viral metacaspases are widespread in the ocean. We also discovered a virus that contains both a reverse transcriptase and a transposase; although highly speculative, we suggest such a genetic complement would potentially allow this virus to exploit a latency propagation mechanism. Application of single virus genomics provides a powerful opportunity to circumvent cultivation of viruses, moving directly to genomic investigation of naturally occurring viruses, with the assurance that the sequence data is virus-specific, non-chimeric and contains no cellular contamination.