4,997 research outputs found
Passaging of a Newcastle disease virus pigeon variant in chickens results in selection of viruses with mutations in the polymerase complex enhancing virus replication and virulence
No full textSome Newcastle disease virus (NDV) variants isolated from pigeons (pigeon paramyxovirus type 1; PPMV-1) do not show their full virulence potential for domestic chickens but may become virulent upon spread in these animals. In this study we examined the molecular changes responsible for this gain of virulence by passaging a low-pathogenic PPMV-1 isolate in chickens. Complete genome sequencing of virus obtained after 1, 3 and 5 passages showed the increase in virulence was not accompanied by changes in the fusion protein – a well known virulence determinant of NDV – but by mutations in the L and P replication proteins. The effect of these mutations on virulence was confirmed by means of reverse genetics using an infectious cDNA clone. Acquisition of three amino acid mutations, two in the L protein and one in the P protein, significantly increased virulence as determined by intracerebral pathogenicity index tests in day-old chickens. The mutations enhanced virus replication in vitro and in vivo and increased the plaque size in infected cell culture monolayers. Furthermore, they increased the activity of the viral replication complex as determined by an in vitro minigenome replication assay. Our data demonstrate that PPMV-1 replication in chickens results in mutations in the polymerase complex rather than the viral fusion protein, and that the virulence level of pigeon paramyxoviruses is directly related to the activity of the viral replication complex
Gabriel Ajak Lat
No full textabstract: Gabriel was ten years old when he left his village.
“Lost Boys Found” is an ongoing, interdisciplinary project that is collecting, recording and archiving the oral histories of the Lost Boys/Girls of Sudan. The collection is a work-in-progress, seeking to record the oral history of as many Lost Boys/Girls as are willing, and will be used in a future book.Age: 27Region: Bahr al GhazalThis picture and bio was donated to the Lost Boys Found project from The Arizona Lost Boys Cente
Providence College Faculty Author Series 2013-2014: Fr. Gabriel Pivarnik
No full textIn this installment, Fr. Gabriel Pivarnik discusses his book Toward a Trinitarian Theology of Liturgical Participation and his reflections on the history of active participation within the Catholic Church
Providence College Faculty Author Series 2013-2014: Fr. Gabriel Pivarnik
No full textIn this installment, Fr. Gabriel Pivarnik discusses his book Toward a Trinitarian Theology of Liturgical Participation and his reflections on the history of active participation within the Catholic Church
Manuscript Poem "John Keats" by Dante Gabriel Rossetti
No full textabstract: Concerning the manuscript for "John Keats".Publication Details: Not the same version as some published versions of "John Keats."Curator's Note: Handwriting in upper right corner reads "Rossetti's Handwriting." Writing on verso reads "Dante Gabriel Rossetti. Mss.
British Museum Reader's Ticket of Dante Gabriel Rossetti
No full textabstract: Concerning a Reader's Ticket of Dante Gabriel Rossetti.Transcription Details: Card reads:
Poet's article 8 {? Nap.} /661
{?dilk Gllucci}
Aug 10 DG RossettiCreation Date Details: Undated range is the author's lifespan. Date and month listed on ticket read "Aug 10.
Fluctuating effects of genetic and plastic changes in body mass on population dynamics in a large herbivore
No full textRecent studies suggest that evolutionary changes can occur on a contemporary time scale. Hence, evolution can influence ecology and vice-versa. To understand the importance of eco-evolutionary dynamics in population dynamics, we must quantify the relative contribution of ecological and evolutionary changes to population growth and other ecological processes. To date, however, most eco-evolutionary dynamics studies have not partitioned the relative contribution of plastic and evolutionary changes in traits on population, community, and ecosystem processes. Here, we quantify the effects of heritable and non-heritable changes in body mass distribution on survival, recruitment, and population growth in wild bighorn sheep (Ovis canadensis) and compare their importance to the effects of changes in age structure, population density, and weather. We applied a combination of a pedigree-based quantitative genetics model, statistical analyses of demography, and a new statistical decomposition technique, the Geber method, to a long-term data set of bighorn sheep on Ram Mountain (Canada), monitored individually from 1975 to 2012. We show three main results: (1) The relative importance of heritable change in mass, non-heritable change in mass, age structure, density, and climate on population growth rate changed substantially over time. (2) An increase in body mass was accompanied by an increase in population growth through higher survival and recruitment rate. (3) Over the entire study period, changes in the body mass distribution of ewes, mostly through non-heritable changes, affected population growth to a similar extent as changes in age structure or in density. The importance of evolutionary changes was small compared to that of other drivers of changes in population growth but increased with time as evolutionary changes accumulated. Evolutionary changes became increasingly important for population growth as the length of the study period considered increased. Our results highlight the complex ways in which ecological and evolutionary changes can affect population dynamics and illustrate the large potential effect of trait changes on population processes
On the effect of rapid area change in perching-like maneuvers
No full textA perching bird is able to rapidly decelerate at a high angle of attack while maintaining lift and control. However, the underlying aerodynamic mechanism is poorly understood. We perform a study on a simultaneously decelerating and pitching airfoil section as a simple perching model. First, we use analytic arguments to establish the inertial non-circulatory force on a wing section, and its dependence on the shape change number, ? ??, the ratio between the rate of change of frontal dimension and the initial translational velocity. Next, we report that forces measured on a towed and pitched airfoil at Re = 22000, and forces from simulations at Re = 2000, are found to be well above non-circulatory predictions, exhibiting high lift and drag. Flow-field visualizations, both from Particle Image Velocimetry and simulations, reveal strong coherent vortical structures in the wake and near the body. At a higher shape change number, vortices in the wake convect more quickly than at a lower shape change number, generating higher drag. Additionally, separation of the LEV and positive vorticity near the body is reduced at a higher shape change number, increasing lift. Thus wake manipulation through rapid area change provides a means through which a perching bird can maintain high lift and drag simultaneously while slowing to a controlled stop
Suplemento 32. Gabriel Moedano Navarro. 75 (2005) abril. Diario de Campo. Boletín Interno de los investigadores del área de Antropología
No full text- Gabriel Moedano Navarro un hombre de su tiempo por Benjamín Muratalla. - Gabriel Moedano explorador gozoso de inframundos por Andrés Medina Hernández. - Hasta pronto, Gabriel por Jesús Montoya. - Homenaje a Gabriel Moedano por Cristina Barros. - Gabriel Moedano, el amigo por Jesús Monjarás Ruiz. - A Gabriel por Amparo Sevilla. - Algunas remembranzas en torno al maestro Gabriel Moedano por Norma Lazcano Arce. - Gabriel Moedano por Marco Buenrostro. - Gabriel Moedano por Katrin S. Flechsig. - A mi maestro con cariño por Yolanda Torres Martínez. - Corazón gigante por María Cristina Díaz Pérez
Open Doors presents, Nasario Garcia, E. A. Mares, Gabriel Melendez, and Jane Young
No full textThe Open Doors series presents a conversation about writing on New Mexican culture with Nasario Garcia, author of ""Brujas, Bultos y Brazaz: Tales of witchcraft and the supernatural in the Pecos Valley,"" E. A. Mares, author of ""Padre Martinez: a new perspective on Taos,"" and Gabriel Melendez and Jane Young, co-authors of ""Multicultural Southwest: A Reader."
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