Relevant bibliographies by topics / Variants viraux

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Academic literature on the topic 'Variants viraux'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Variants viraux"

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Feraoun, Yanis, Pauline Maisonnasse, Roger Le Grand, and Anne-Sophie Beignon. "COVID-19, des vaccins à la vitesse de l’éclair." médecine/sciences 37, no. 8-9 (2021): 759–72. http://dx.doi.org/10.1051/medsci/2021094.

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Un vaccin est nécessaire pour endiguer efficacement, à moyen et long terme, une pandémie comme celle de la COVID-19 (coronavirus disease 2019). Le développement de vaccins contre le virus responsable de la maladie, le SARS-CoV-2 (severe acute respiratory syndrome-coronavirus 2), a été débuté dès la publication de la séquence du génome viral. Ce développement a progressé à une vitesse sans précédent, avec un premier essai clinique réalisé peu de temps après, en mars 2020. Un an plus tard, une dizaine de vaccins reposant sur des concepts différents, dont certains n’avaient été testés que dans des essais cliniques, sont autorisés dans le cadre de procédures d’urgence. Dans cet article, nous passons en revue ces différents vaccins, nous comparons leurs propriétés et nous discutons les défis auxquels ils sont confrontés, en particulier l’émergence de nouveaux variants viraux.
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Sánchez C., Víctor. "Fricación de erre en el español de Costa Rica: Un caso de escisión fonológica." Revista de Filología y Lingüística de la Universidad de Costa Rica 11, no. 1 (2015): 63. http://dx.doi.org/10.15517/rfl.v11i1.16249.

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El español en Costa Rica tiene, por lo menos, dos variantes dialectales bien diferenciadas: el español guanacasteco y el español del Valle Central y las zonas a las que se ha expandido, en virtud del movimiento migratorio de este siglo especialemnete.El presente estudio se refiere a la segunda variante dialectal.
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Sánchez Corrales, Víctor. "Escisión fonológica de /.J/ en el español de Costa Rica." Revista de Filología y Lingüística de la Universidad de Costa Rica 12, no. 2 (2015): 129. http://dx.doi.org/10.15517/rfl.v12i2.17072.

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El español en Costa Rica tiene, por lo menos, dos variantes dialectales bien diferenciadas: el español guanacasteco y el español del Valle Central y las zonas a las que se ha expandido, especialmente en virtud del movimiento migratorio de este siglo. El presente estudio se refiere a la segunda variante dialectal.
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Ajana, F. "Les variants du virus de l'hépatite B virale." Journal de Pédiatrie et de Puériculture 19, no. 2 (2006): 52–55. http://dx.doi.org/10.1016/j.jpp.2005.12.005.

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Chen, Jian-Min, Anthony F. Herzig, Emmanuelle Génin, Emmanuelle Masson, David N. Cooper, and Claude Férec. "Scale and Scope of Gene-Alcohol Interactions in Chronic Pancreatitis: A Systematic Review." Genes 12, no. 4 (2021): 471. http://dx.doi.org/10.3390/genes12040471.

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Background: Excessive alcohol consumption has long been known to be the primary cause of chronic pancreatitis (CP) but genetic risk factors have been increasingly identified over the past 25 years. The scale and scope of gene-alcohol interactions in CP nevertheless remain unclear. Methods: All studies that had obtained genetic variant data concurrently on alcoholic CP (ACP) patients, non-ACP (NACP) patients and normal controls were collated. Employing normal controls as a common baseline, paired ORACP and ORNACP (odds ratios associated with ACP and NACP, respectively) values were calculated and used to assess gene-alcohol interactions. Results: Thirteen variants involving PRSS1, SPINK1, CTRC, CLDN2, CPA1, CEL and CTRB1-CTRB2, and varying from very rare to common, were collated. Seven variants had an ORACP > ORNACP, which was regarded as an immediate indicator of gene-alcohol interactions in CP. Variants with an ORACP < ORNACP were also found to interact with alcohol consumption by virtue of their impact on age at first pancreatitis symptoms in ACP. Conclusions: This study revealed evidence for extensive gene-alcohol interactions in CP. Our findings lend support to the hypothesis that alcohol affects the expression of genetically determined CP and highlight a predominant role of weak-effect variants in the development of ACP.
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Glasa, Miroslav, Katarína Šoltys, Lukáš Predajňa, et al. "High-throughput sequencing of Potato virus M from tomato in Slovakia reveals a divergent variant of the virus." Plant Protection Science 55, No. 3 (2019): 159–66. http://dx.doi.org/10.17221/144/2018-pps.

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High-throughput sequencing (HTS) analysis of tomato (Solanum lycopersicum) samples revealed the presence of Potato virus M (PVM) in this crop in Slovakia. Full-length genomes of three PVM isolates were obtained using both HTS and Sanger sequencing validation. While two isolates (T40 and T50) were shown to belong to major Group I, a divergent T20 isolate was phylogenetically unrelated to any known PVM variant, potentially representing a new phylogenetic group. Despite a relatively high intraspecies diversity (17.3 ± 0.3%), no evidence of recombination was detected in the dataset of available complete PVM sequences. Conventional screening of tomato plants in Slovakia using ELISA and RT-PCR further confirmed a frequent occurrence of PVM in this host. Developed RT-PCR showed its polyvalence to detect the PVM Group I isolates, however, in silico analysis of primer binding sites indicated its compromised use for Group II isolates. Our results further pinpoint the significance of HTS for unbiased unveiling of virus diversity and a need for continual optimisation of molecular detection tools.
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Smith, R. E. "A new fluorescent detection system for identifying variant hemoglobins after gel electrophoresis using immunobinding with monoclonal antibodies." Journal of Histochemistry & Cytochemistry 34, no. 5 (1986): 585–91. http://dx.doi.org/10.1177/34.5.3084625.

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This paper describes a low-resolution system for identifying variant hemoglobins with great sensitivity and specificity. After electrophoresis of the hemoglobin sample in a gel, fixation is used to entrap the hemoglobin. The gel is dried, incubated with a monoclonal antibody against the desired hemoglobin, then incubated with a second antibody against the first antibody which is conjugated with the enzyme beta-d-galactosidase. An enzyme overlay membrane containing a fluorogenic substrate is then placed on the gel surface, incubated, and removed, yielding an immunofluorescent print. The entire procedure takes only two hours, and by virtue of fluorescent detection gives sharper band resolution and greater sensitivity than conventional dye methods. The system clearly distinguishes SS sickle-cell hemoglobin from heterozygous and "S-like" hemoglobins. The technique therefore holds promise as a powerful probe for allelic variants.
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Rudensey, Lyle M., Jason T. Kimata, E. Michelle Long, Bryce Chackerian, and Julie Overbaugh. "Changes in the Extracellular Envelope Glycoprotein of Variants That Evolve during the Course of Simian Immunodeficiency Virus SIVMne Infection Affect Neutralizing Antibody Recognition, Syncytium Formation, and Macrophage Tropism but Not Replication, Cytopathicity, or CCR-5 Coreceptor Recognition." Journal of Virology 72, no. 1 (1998): 209–17. http://dx.doi.org/10.1128/jvi.72.1.209-217.1998.

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ABSTRACT Simian immunodeficiency virus SIVMne, like human immunodeficiency virus, evolves from a macrophage-tropic, non-syncytium-inducing virus at early times in infection to a T-cell-tropic, syncytium-inducing, cytopathic virus population over the course of progression to AIDS. Because the viruses isolated late in SIVMne infection of macaques include a complex mixture of variants, the viral determinants of such phenotypic changes have not been defined. To identify genetic changes that are important to virus evolution in the host, we constructed chimeric viruses by introducing variant envelope genes representative of proviruses throughout the course of infection and disease into the SIVMne parental clone (SIVMneCL8) that infected the macaque. The chimeric viruses expressed sequences encoding the surface unit of the envelope glycoprotein (Env-SU) of variants cloned between 35 and 170 weeks postinfection. The chimera with Env-SU from 35 weeks postinfection encoded only four changes in V1 compared to SIVMneCL8, whereas the chimeras encoding Env-SU from variants isolated later in infection encoded progressively more mutations both in V1 and elsewhere. Like SIVMneCL8, the chimeras were infectious for CEMx174 cells and macaque peripheral blood mononuclear cells. However, in contrast to SIVMneCL8, the chimeric viruses did not infect macaque macrophages, although each retained the ability to recognize the CCR-5 coreceptor. Thus, these data provide direct evidence that changes which evolve in Env-SU during the course of SIVMne infection do not alter CCR-5 interactions. Viruses encoding Env-SU from the latest times in infection (121 to 170 weeks postinfection), after disease was apparent, were syncytium inducing. However, these viruses were not highly cytopathic, suggesting that additional viral determinants may be required for the rapidly replicating, cytopathic phenotype of the uncloned mixed variant population. Changes in Env-SU did allow the virus to escape serum neutralizing antibodies that recognized the SIVMneCL8 parent. Moreover, the chimera encoding the Env-SU of a virus from 35 weeks postinfection, which differed from SIVMneCL8 only in V1, was not sensitive to neutralization by infected macaque sera, suggesting that V1 may define a portion of the principal neutralizing determinant for SIVMne. Together, these data suggest that SIV variants with changes in the Env-SU may be selected primarily by virtue of their ability to escape neutralizing antibody recognition.
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Goldstein, Rena Beatrice. "You Are Only as Good as You Are Behind Closed Doors." Precollege Philosophy and Public Practice 2 (2020): 88–106. http://dx.doi.org/10.5840/p42020348.

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Virtues are standardly characterized as stable dispositions. A stable disposition implies that the virtuous actor must be disposed to act well in any domain required of them. For example, a politician is not virtuous if s/he is friendly in debate with an opponent, but hostile at home with a partner or children. Some recent virtue theoretic accounts focus on specific domains in which virtues can be exercised. I call these domain-variant accounts of virtue. This paper examines two such accounts: Randall Curren and Charles Dorn’s (2018) discussion of virtue in the civic sphere, and Michael Brady’s (2018) account of virtues of vulnerability. I argue that being consistent with the standard characterization of virtue requires generalizing beyond a domain. I suggest four actions the authors could take to preserve their accounts while remaining consistent with the standard characterization. I also discuss how virtue education could be enhanced by domain-variant accounts.
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Mota, Carla Da Silva, Fumio Honma Ito, Marlon Vicente Silva, et al. "Estudo imunológico e genético de 10 isolados do vírus da raiva de morcegos do Rio de Janeiro, Sudeste do Brasil." Brazilian Journal of Veterinary Research and Animal Science 47, no. 1 (2010): 74. http://dx.doi.org/10.11606/issn.1678-4456.bjvras.2010.26851.

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O presente trabalho visou estudar dez isolados de vírus da raiva de morcegos hematófagos e não-hematófagos do Estado do Rio de Janeiro em suas características genéticas quanto aos genes N e G. Além disso, estudou-se a resposta de camundongos vacinados com a vacina antirrábica produzida pela replicação da amostra Pitman-Moore em cultivo celular, frente ao desafio com estes isolados virais, utilizando-se um ensaio imunológico baseado no teste de potência NIH. A vacina antirrábica utilizada na imunização dos camundongos ofereceu proteção em mais de 80% dos camundongos vacinados com a diluição 1:5 da vacina, frente à maioria dos isolados. A análise filogenética do gene da proteína N apresentou um padrão de agregação dividido em variante de morcego hematófago e variante de morcego insetívoro, com todos os isolados de morcegos frugívoros Artibeus sp. tendo sido segregados com a variante característica de morcegos Desmodus rotundus. Foram observadas diferenças filogenéticas entre as variantes do vírus da raiva de morcego hematófago isoladas na Região Noroeste do Estado do Rio de Janeiro e aquelas isoladas nas Regiões Metropolitana e Sul do Estado. A substituição do resíduo ácido aspártico por ácido glutâmico na posição 118, encontradas na caracterização genética da proteína G dos isolados 704/97BR-DR e 151/98BR-DR, permite inferir que esta posição esteja relacionada à antigenicidade viral. Não foram observadas diferenças genéticas temporais entre os isolados estudados. A vacina antirrábica utilizada ofereceu proteção satisfatória contra a maioria dos isolados estudados.
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Dissertations / Theses on the topic "Variants viraux"

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D'Arienzo, Valentina. "Caractérisation des glycoprotéines d'enveloppe des variants viraux impliqués dans la transmission du virus de l'hépatite C." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR3803/document.

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Les variants viraux impliqués dans la transmission du VHC ont rarement été étudiés en raison des difficultés rencontrées pour recruter des patients au stade de la primo-infection. Pour mener cette étude, nous avons analysé le goulot d’étranglement génétique subit par les quasi-espèces virales au cours de 3 accidents d’exposition au sang impliquant des représentants du personnel soignant contaminés par piqûre d’aiguille. En utilisant la technique d’amplification de génomes uniques nous avons obtenu les gènes codant les glycoprotéines d’enveloppe virales E1E2 des variants viraux présents dans ces quasi-espèces. Ces gènes ont été séquencés et soumis à une analyse phylogénétique. Nous avons ensuite pu étudier les propriétés phénotypiques des glycoprotéines d’enveloppe dérivées de variants qui apparaissent au stade très précoce de l’infection. Pendant cette période, le VHC pourrait être plus vulnérable à l’élimination par des vaccins préventifs ou par des immunothérapies
Little is known about the transmitted variants responsible for the spread of HCV infection, principally because of the difficulties to recruit patients early enough in infection. To address this issue, we proposed to track the genetic bottleneck event in HCV quasispecies, leading to productive clinical infection in three health care workers accidentally contaminated through needlestick accidents. By using a single genome amplification (SGA) approach we identified genes coding the viral envelope glycoprotein E1E2 which composed these quasispecies. The E1E2 sequences were then directly sequenced and subjected to a phylogenetic analysis. By cloning these full-length E1E2 sequences, we investigated the phenotypic properties of the envelope glycoproteins potentially involved in selective HCV transmission and early stage of infection, a period during which the virus might be most vulnerable to elimination by preventive vaccines or immunotherapies
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Labaille, Jennifer. "Conception d'un vaccin recombinant contre la maladie de Marek d'après l'étude de la dynamique des populations de variants du vaccin CV1988/RISPENS." Thesis, Tours, 2013. http://www.theses.fr/2013TOUR4014.

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Le Gallid herpesvirus 2 (GaHV-2), responsable de lymphomes T du poulet, est contrôlé par le vaccin CVI988/Rispens. Mes travaux de thèse ont montré que le vaccin était composé, au contraire des souches virulentes, d’une population dynamique de variants viraux majoritairement délétés de la région promotrice et d’une partie variable de l’extrémité 5’ du gène LAT codant des microARN et associé à la latence virale. Dans une approche vaccinale, un virus recombinant correspondant à l’un des variants majoritaires du vaccin CVI988/Rispens a été généré à partir d’une souche GaHV-2 hypervirulente, clonée en bacmide. Nous avons montré que ce recombinant, présentant une perte de pathogénicité presque totale, était capable de protéger significativement les poulets lors d’une épreuve avec des souches GaHV-2 hypervirulentes. Ces travaux posent les bases du développement de nouveaux vaccins à partir de souches hypervirulentes émergentes
Gallid herpesvirus 2 (GaHV-2), responsible for T-cell lymphomas chicken, is controlled by the vaccine CVI988/Rispens. My work has shown that the vaccine contains, unlike virulent strain, a viral variants population mostly deleted from the promoter region and a variable portion of the 5' end of the gene LAT encoding microRNA and associated with viral latency. In a vaccine approach, a recombinant virus corresponding to a majority variant of the CVI988/Rispens vaccine was generated from a hypervirulent strain GaHV-2, cloned as bacmid. We showed that recombinant, with an almost total loss of pathogenicity, was able to significantly protect chickens against challenge with virulent strains GaHV-2. This work lays the basis for the development of new vaccines from emerging virulent strains
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Brengel-Pesce, Carine. "Virus de l'immunodéficience humaine de type 1 (VIH-1) et atteinte du système nerveux central : analyse génétique et biologique de variants viraux dérivés de patients atteints d'encéphalite à VIH-1." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10048.

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Fins, Ivo Joel Salgueiro. "Molecular surveillance of parvoviruses circulating in cats in the United Kingdom." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/23095.

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This dissertation was developed under the Curricular Traineeship scope, which took place at the University of Nottingham, between July 2016 and April 2017. Feline panleukopenia virus (FPV) and canine parvovirus (CPV), two closely related viruses, are known to cause acute enteritis in companion animals. Cats may be infected by strains of both viruses. Population-based surveillance studies have been lacking. This study investigated the prevalence of parvoviruses in a cross-sectional survey of clinically-healthy cats housed within 13 shelters across the United Kingdom, comprising 818 faecal samples. FPV/CPV DNA was detected by PCR. Overall, the prevalence of parvovirus was 3.8%. Five FPV/CPV-2a like strains and one CPV-2b were identified by sequence analysis. These results showed that parvoviruses are circulating in the UK feline population, providing an insight about parvovirus occurrence in a non-clinical population, which reinforces the possibility that asymptomatic cats may be important reservoirs for infection maintenance in companion animals; Resumo: Vigilância molecular dos Parvovírus circulantes em gatos no Reino Unido Esta dissertação foi elaborada no âmbito do Estágio Curricular, realizado na Universidade de Nottingham, entre julho de 2016 e abril de 2017. O vírus da panleucopénia felina (FPV) e o parvovirus canino (CPV), dois vírus estreitamente relacionados, são conhecidos por causar enterite aguda em animais de companhia. Os gatos podem ser infetados por estirpes de ambos os vírus. Investigou-se a prevalência de parvovirus através de um estudo transversal em gatos clinicamente saudáveis acolhidos em 13 abrigos de distintas localizações no Reino Unido, somando 818 amostras fecais. O DNA do FPV/CPV foi detetado por PCR. Globalmente, a prevalência de infeção por parvovirus foi de 3,8%. Cinco estirpes virais compatíveis com FPV/CPV-2a e uma estirpe CPV-2b foram identificadas através de sequenciação. Os resultados comprovam que diferentes variantes de parvovirus circulam na população felina do país, reforçando a possibilidade de gatos assintomáticos constituírem reservatórios importantes para manutenção da infeção em animais de companhia.
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Gamon, Thaís Helena Martins. "Estudo da etiopatogenia do vírus da raiva utilizando um modelo murino de neuroinfecção." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-16092015-123105/.

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A raiva é uma zoonose quase sempre fatal, que causa milhares de mortes humanas por ano em todo mundo. Essa enfermidade manifesta-se nos mamíferos em duas formas clínicas: furiosa e paralítica. Distinções em relação à evolução, manifestações clínicas, lesões, distribuição e respectiva carga viral no Sistema Nervoso Central (SNC) podem estar relacionadas às características de neuroinvasividade e neuropatogenicidade das diferentes variantes do vírus da raiva (RABV). O objetivo deste projeto foi estabelecer um modelo para o estudo da patogênese da raiva em camundongos inoculados com vírus fixo CVS/31 e variantes de rua do RABV originárias de bovino (variante 3 compatível com isolados de morcegos hematófagos) e de canídeo silvestre (variante compatível com isolados de canídeo silvestre). Para estabelecer o modelo murino, 24 camundongos isogênicos da linhagem BALB/c, de três semanas de idade foram inoculados com 103 DLIC50/0,03mL por via intracerebral (IC) para confirmar a neurovirulência das diferentes variantes do RABV. De modo concomitante, 32 camundongos desta mesma linhagem e faixa etária, foram inoculados com 105 DLIC50/0,03mL pela via coxim plantar (CP) com o intuito de mimetizar a progressão da infecção natural. Para o estudo da patogênese do RABV foram analisados durante um período de trinta dias após a inoculação (DPI) em camundongos pela via CP os seguintes parâmetros: manifestações clínicas, alterações histopatológicas, distribuição antigênica viral pela técnica de imuno-histoquímica (IHQ) e distribuição de RNA viral pela técnica da reação em cadeia da polimerase em tempo real precedida pela transcrição reversa (RT-qPCR) - sistema SYBR Green em diversos segmentos do SNC. Todos os camundongos inoculados com as três amostras do RABV apresentaram sintomas compatíveis com a forma paralítica da doença, tais como: piloereção, perda de peso, postura arqueada, prostração e paresia dos membros posteriores. Apesar de não ser possível observar diferenças de neuropatogenicidade entre as variantes virais, detectaram-se diversidade de virulência entre essas estirpes, demonstrado pelas distinções de período de incubação e taxa de letalidade. Ao analisar os resultados, também foi possível observar diferenças entre a neurovirulência e a neuroinvasividade das diferentes variantes do RABV. Nos camundongos inoculados com CVS/31 pela via CP, no 6º DPI, observaram-se predomínio de manguitos perivasculares na medula espinhal e degeneração neuronal em córtex e intensa distribuição antigênica de RABV no tronco encefálico. Nos camundongos inoculados via CP com amostras do RABV originárias de bovino, no 8º DPI, apresentaram moderada distribuição de manguitos perivasculares na medula e córtex e intensa distribuição antigênica no tálamo. Já nos animais inoculados com a amostra de canídeo silvestre, no 9ºDPI, relataram-se moderada distribuição de manguitos perivasculares no tronco encefálico e moderada distribuição antigênica no córtex. Além disso, foi observado discrepâncias na comparação entre a intensidade e distribuição de marcações antigênicas pela IHQ e inferência semi-quantitativa de distribuição de RNA viral analisada pelo RT-qPCR-sistema SYBR Green no SNC de camundongos
Rabies is a zoonotic disease usually fatal, causing thousands of human deaths each year worldwide. This disease manifests itself in mammals in two clinical forms: furious and paralytic. Distinctions regarding the evolution, clinical manifestations, injuries, distribution and their viral load on the central nervous system (CNS) may be related to the characteristics of neuroinvasiveness and neuropathogenicity of different variants of rabies virus (RABV). The objective of this project was to establish a model to study the pathogenesis of rabies in mice inoculated with fixed virus CVS / 31 and RABV Street variants originating from bovine (variant 3 - compatible with isolates from vampire bats) and wild canid (variant supports isolated from wild canid). To establish the mouse model, 24 mice of the inbred strain BALB/c, three weeks old were inoculated with 103DLIC50/0,03mL intracerebrally (IC) to confirm the neurovirulence of the different variants of RABV. Concomitantly, 32 mice of the same lineage and age were inoculated with 105DLIC50/0,03mL via footpad (CP) in order to mimic the natural progression of the infection. To study the pathogenesis of RABV CP the following parameters were analyzed over a period of thirty days after inoculation (DPI) in mice via CP: clinical, histopathological changes, viral antigen distribution by the technique of immunohistochemistry (IHC) and distribution of RNA by real-time polymerase chain reaction technique preceded by reverse transcription (RT-qPCR) - SYBR Green system in various segments of the CNS. All mice inoculated with the three RABV samples showed symptoms consistent with the paralytic form of the disease, such as ruffled fur, weight loss, hunched, prostration and paresis of the hind limbs. Although it is not possible to observe neuropathogenicity differences between viral variants, the virulence diversity is detected between these strains demonstrated by distinctions incubation period and fatality rate. When analyzing the results, it was also possible to observe differences between neurovirulence and neuroinvasiveness of different variants of RABV. In mice inoculated with CVS/31 via CP on the 6th DPI, there were predominance of perivascular cuffing in spinal cord and neuronal degeneration in cortex and intense antigenic distribution of the RABV in the brainstem. Mice inoculated via CP with RABV samples originating from bovine on the 8thDPI had moderate distribution of perivascular cuffing in the medulla and cortex and intense antigenic distribution in the thalamus. The animals inoculated with the sample of wild canid in 9thDPI reported a moderate perivascular cuffing distribution in the brainstem and moderate antigenic distribution in the cortex. Additionally, discrepancies were observed when comparing the intensity and distribution of antigenic tags by IHC, semi-quantitative inference viral RNA distribution analyzed by RT-qPCR using SYBR Green system in the mouse CNS
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Flanagan, Stephen G. "A genetic analysis of measles virus haemagglutinin variants." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317503.

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Fages, Marie-Philippe Bertagnoli Stéphane. "Identification d'un nouveau variant apathogène du virus de la maladie hémorragique virale du lapin (RHDV)." [S.l.] : [s.n.], 2007. http://oatao.univ-toulouse.fr/1755/1/debouch_1755.pdf.

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Thermet, Séverine. "Étude moléculaire et biologique de variants du VHB." Lyon 1, 2006. http://www.theses.fr/2006LYO10139.

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L'Organisation Mondiale de la Santé estime à plus de 370 millions le nombre de porteurs chroniques du virus de l'Hépatite B (VHB). L'éradication de cette maladie, même dans les pays développés ayant accès à tous les équipements médicaux, est difficile. Ceci est due en partie à l'existence de variants du VHB. Leur étude est indispensable pour mieux comprendre la biologie du VHB et lutter toujours plus efficacement contre ce virus. Toutefois l'amplification des génomes entiers des variants du VHB est souvent difficile. Ainsi durant ma thèse je me suis intéressée à différents variants du VHB. Dans un premier temps, mon travail s'est basé sur un patient (Z1) présentant à la fois de forts taux d'AgHBs et d'anticorps anti-HBs. Les analyses moléculaires et biologiques ont montré que le patient était infecté par un VHB d'apparence sauvage. L'étude de l'affinité des anti-HBs de Z1 a permis d'établir qu'il avait développé une réponse immunitaire quasi-monoclonale vis-à-vis d'un épitope antigénique différent de celui porté par le virus circulant. Dans un second temps, j'ai développé une nouvelle technique d'amplification pour l'étude des variants de VHB difficiles à obtenir par les techniques standard de PCR. Pour ce faire, j'ai appliqué une technique innovante et hautement sensible, nommée amplification en cercle roulant (RCA). La RCA associée à une PCR spécifique du VHB amplifie l'ADNccc avec une sensibilité similaire à celle d'une PCR en temps réel. La RCA présente un avantage certain puisqu'elle permet d'obtenir le génome viral entier et non des fragments sous génomiques. L'étude d'un patient infecté par un VHB résistant à la lamivudine a validé l'efficacité, la fidélité et la haute sensibilité de la RCA. En conclusion, ce travail a montré qu'il était indispensable d'étudier de grandes cohortes de patients pour pouvoir dégager des consensus concernant les différents types de variants du VHB. La RCA devrait être un atout majeur dans l'étude des variants du VHB, et aussi pour l'étude de l'ADNccc qui est à l'origine de la persistance viral et de la propagation des mutations
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Campos, Angélica Cristine de Almeida. "Estudo genético da variante do vírus da raiva mantida por populações do morcego hematófago Desmodus rotundus." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-14092011-175622/.

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Dados da Organização Mundial da Saúde (OMS) mostram que a raiva é um problema de saúde pública podendo acarretar sérios prejuízos ambientais e econômicos, a despeito da existência de vacinas eficazes de uso humano e veterinário. Segundo seu último informe, estima-se que no mundo em torno de 55.000 pessoas por ano morrem de raiva. O cão permanece como principal transmissor da raiva para o homem e também como principal vítima da doença. Nos países que conseguiram controlar a raiva em animais domésticos, o vírus se mantém circulante na natureza por meio dos animais silvestres, sendo os morcegos apontados como a segunda espécie transmissora da raiva a humanos. Os Lyssavirus têm sido detectados em morcegos, em diversos continentes, sendo identificados como transmissor em dez das onze espécies de Lyssavirus. Fósseis de morcego mostram sua presença há 50 milhões de anos. Mas somente em 1911, Carini relacionou pela primeira vez a raiva aos morcegos, levantando a hipótese destes serem os transmissores da doença a outros animais. Há registros de que o vírus da raiva foi isolado em pelo menos 41 das 167 espécies de morcegos brasileiras, sendo que a maioria dessas espécies está relacionada a atividades humanas com a presença destes animais próximos ao local de trabalho e moradia das pessoas. Os morcegos hematófagos Desmodus rotundus são encontrados do norte do México até a costa norte do Chile, região central da Argentina e costa do Uruguai e com exceção do Chile. Esta espécie de morcego tem sido apontada como reservatório natural do vírus da raiva nesta região. Alguns pesquisadores observaram que a raiva em morcegos não hematófagos precede a raiva bovina e em animais de estimação, sugerindo que os morcegos não hematófagos podem ser o elo entre a raiva silvestre e a raiva urbana e o fato de se detectar a variante mantida por morcegos hematófagos Desmodus rotundus em cães e gatos mostra que o papel deste morcego no ciclo da raiva não está limitado à raiva silvestre. As características dos Lyssavirus adaptados a morcegos têm mostrado diferenças quando comparadas à raiva relacionada aos carnívoros, confirmando a necessidade do desenvolvimento de metodologias que permitam estudos complementares mais precisos a respeito da biologia e epidemiologia da raiva em quirópteros. A escassez de dados na literatura, até o momento, a respeito do genoma completo da variante do vírus da raiva mantida por populações de morcegos hematófagos Desmodus rotundus, deixa uma lacuna no entendimento da epidemiologia molecular deste vírus. A importância epidemiológica desta espécie na transmissão da raiva é inquestionável. Neste estudo foi sequenciado e analisado, o genoma da variante do vírus da raiva mantido por populações de morcego hematófago Desmodus rotundus isolado de um morcego hematófago Desmodus rotundus. A amostra, procedente de área endêmica no Estado de São Paulo, foi filogeneticamente comparada com o genoma da amostra padrão para a espécie viral 1 - Rabies virus e outras amostras pertencentes ao ciclo aéreo ou terrestre de transmissão, disponíveis no GenBank, identificando possíveis padrões de diferenciação, próprios do ciclo aéreo, e em alguns casos relacionados somente à variante estudada.
Data from the World Health Organization (WHO) show that rabies is a public health problem which can cause serious environmental and economic damage, despite the existence of effective vaccines for human and veterinary use. According to WHO latest report, estimated that worldwide around 55,000 people per year died of rabies. The dog remains the main transmitter of rabies to humans as well as the main victim of the disease. In countries that were successful in controlling rabies in domestic animals, the virus is still circulating in nature by wild animals and the bats are seen as the second species transmitting rabies to humans. The Lyssavirus have been detected in bats in several continents and is identified as a transmitter in ten of eleven species of Lyssavirus. Bat fossils show their presence for 50 million years. But only in 1911, in the first time Carini related to rabies at bats, raising the possibility of these being the transmitters of the disease to other animals. Reports show that the Rabies virus was isolated in at least 41 of the 167 species of bats in Brazil, with the majority of these species is related to human activities with the animals living near the local job and houses of people. The vampire bat Desmodus rotundus is found from northern Mexico to northern Chile coast, central coast of Argentina and Uruguay and with the exception of Chile. This bat species has been identified as a natural reservoir of the Rabies virus in this region. Some researchers observed that rabies into non-hematophagous bats precedes the bovine rabies and in pets, suggesting that the non-hematophagous bats may be the link between wildlife rabies and urban rabies and the fact that detect the variant maintained by vampire bats Desmodus rotundus in dogs and cats shows that the role of bat rabies in the cycle is not limited to wildlife rabies. The characteristics of Lyssavirus bat adapted have been shown differences when compared to rabies related to the carnivores, confirming the need to develop methods that enable more accurate follow-up studies about the biology and epidemiology of rabies in bats. The paucity of data in the literature to date about the complete genome of the Rabies virus variant maintained by populations of vampire bats Desmodus rotundus leaves a gap in understanding the molecular epidemiology of this virus and the epidemiological importance of this species in the transmission of Rabies virus is unquestionable. In this study we sequenced and analyzed the genome of the Rabies virus variant maintained by populations of bat Desmodus rotundus isolated from a bat Desmodus rotundus. The sample, coming from an endemic area in São Paulo, was phylogenetically compared with the genome of the standard sample for spcies 1 - Rabies virus and other samples belonging to the Terrestrial and Aerial cycles of transmission, available in GenBank, to identify possible patterns of differentiating themselves Aerial cycle and in some cases linked only to variant studied.
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Chackerian, Bryce Charles. "Selection of simian immunodeficiency virus variants during progression to immunodeficiency /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/11492.

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Books on the topic "Variants viraux"

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Yates, M. V. The use of models for granting variances from mandatory disinfection of ground water used as a public water supply. Robert S. Kerr Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, 1990.

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Roberti, Kellee Ann. Variants of infectious hematopoietic necrosis virus selected with glycoprotein-specific monoclonal antibodies. 1987.

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Lichtensteiger, Carol A. Antibody neutralization and MHC-restricted lymphocyte-mediated cytotoxicity of variants of caprine arthritis-encephalitis lentivirus. 1992.

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Sole, Richard, and Santiago F. Elena. Viruses as Complex Adaptive Systems. Princeton University Press, 2018. http://dx.doi.org/10.23943/princeton/9780691158846.001.0001.

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Viruses are everywhere, infecting all sorts of living organisms, from the tiniest bacteria to the largest mammals. Many are harmful parasites, but viruses also play a major role as drivers of our evolution as a species and are essential regulators of the composition and complexity of ecosystems on a global scale. This book draws on complex systems theory to provide a fresh look at viral origins, populations, and evolution, and the coevolutionary dynamics of viruses and their hosts. New viruses continue to emerge that threaten people, crops, and farm animals. Viruses constantly evade our immune systems, and antiviral therapies and vaccination campaigns can be powerless against them. These unique characteristics of virus biology are a consequence of their tremendous evolutionary potential, which enables viruses to quickly adapt to any environmental challenge. This book presents a unified framework for understanding viruses as complex adaptive systems. It shows how the application of complex systems theory to viral dynamics has provided new insights into the development of AIDS in patients infected with HIV-1, the emergence of new antigenic variants of the influenza A virus, and other cutting-edge advances. The book also extends the analogy of viruses to the evolution of other replicators such as computer viruses, cancer, and languages.
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Pettigrove, Glen. Alternatives to Neo-Aristotelian Virtue Ethics. Edited by Nancy E. Snow. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199385195.013.31.

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Most contemporary variants of virtue ethics have a neo-Aristotelian timbre. However, standing alongside the neo-Aristotelians are a number of others playing similar tunes on different instruments. This chapter highlights the four most important virtue ethical alternatives to the dominant neo-Aristotelian chorus. These are Michael Slote’s agent-based approach, Linda Zagzebski’s exemplarism, Christine Swanton’s target-centered theory, and Robert Merrihew Adams’s neo-Platonic account. What these four approaches showcase is the range of possible theoretical structures available to virtue ethicists. A virtue ethicist might attempt to define other normative qualities like goodness or rightness in terms of virtuous traits. But she need not. Instead, she might develop a theory in which virtue is fundamental but other normative qualities obey a logic that is at least partially independent of virtue. This chapter draws attention to an exciting range of possibilities for virtue ethics that both critics and advocates alike will want to explore.
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Tiwald, Justin. Confucianism and Neo-Confucianism. Edited by Nancy E. Snow. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199385195.013.41.

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In this chapter the author defends the view that the major variants of Confucian ethics qualify as virtue ethics in the respects that matter most, which concern the focus, investigative priority, and explanatory priority of virtue over right action. The chapter also provides short summaries of the central Confucian virtues and then explains how different Confucians have understood the relationship between these and what some regard as the chief or most comprehensive virtue, ren (humaneness or benevolence). Finally, it explicates what most Confucians take to be a requirement of all virtues, which the author calls “wholeheartedness,” and concludes by highlighting some neglected implications of the wholeheartedness requirement for ethics more generally. These include reasons for linking conceptions of virtue and human nature, for thinking that good character necessitates that individuals change how things seem to them, and for endorsing automatic as opposed to intensively deliberative judgments and decisions.
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Naicker, Saraladevi, and Graham Paget. HIV and renal disease. Edited by Vivekanand Jha. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199592548.003.0187_update_001.

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The human immunodeficiency virus (HIV) infection epidemic has particularly affected the poorest regions of the world. HIV can directly or indirectly affect different aspects of renal function, and results in a variable expression of kidney disease.Acute kidney injury (AKI) occurs in approximately 20% of hospitalized patients. The prevalence of chronic kidney disease (CKD) amongst HIV-infected patients is reported at 3.5–38% in different regions of the world. The complex interplay between the pheno- and/or genotypic variants of the virus, the genetic make-up of the host, and environmental factors determine the clinical manifestations of renal disease. The association of APOL1 gene variants G1 and G2 with the risk of focal segmental glomerulosclerosis explains the high frequency of HIV-associated nephropathy (HIVAN) in populations of black ethnicity.Anti-retroviral therapy (ART) is effective in preventing progression of HIVAN. Some of the drugs used in ART regimens are potentially nephrotoxic and require dose adjustment or even avoidance in CKD. Progression to end-stage renal disease (ESRD) in HIVAN has been reported to correlate with the extent of chronic damage quantified by renal biopsy.HIV-infected patients requiring dialysis, who are stable on ART, are achieving survival rates comparable to those of non-HIV dialysis populations. Similarly, HIV infection does not seem to adversely affect patient and graft survival rates after kidney transplantation, and there has been no increase in the prevalence of opportunistic infections in transplant recipients on effective ART.
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Ralston, Stuart H. Paget’s disease of bone. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199642489.003.0144_update_001.

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Paget’s disease of bone (PDB) affects up to 1% of people of European origin aged 55 years and above. It is characterized by focal abnormalities of bone remodelling which disrupt normal bone architecture, leading to expansion and reduced mechanical strength of affected bones. This can lead to various complications including deformity, fracture, nerve compression syndromes, and osteoarthritis, although many patients are asymptomatic. Genetic factors play a key role in the pathogenesis of PDB. This seems to be mediated by a combination of rare genetic variants which cause familial forms of the disease and common variants which increase susceptibility to environmental triggers. Environmental factors which have been suggested to predispose to PDB include viral infections, calcium and vitamin D deficiency, and excessive mechanical loading of affected bones. The diagnosis can be made by the characteristic changes seen on radiographs, but isotope bone scans are helpful in defining disease extent. Serum alkaline phosphatase levels can be used as a measure of disease activity. Inhibitors of bone resorption are the mainstay of medical management for PDB and bisphosphonates are regarded as the treatment of choice. Bisphosphonates are highly effective at reducing bone turnover in PDB and have been found to heal osteolytic lesions, and normalize bone histology. Although bisphosphonates can improving bone pain caused by elevated bone turnover, most patients require additional therapy to deal with symptoms associated with disease complications. It is currently unclear whether bisphosphonate therapy is effective at preventing complications of PDB.
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Ralston, Stuart H. Paget’s disease of bone. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0144.

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Paget's disease of bone (PDB) affects up to 1% of people of European origin aged 55 years and above. It is characterized by focal abnormalities of bone remodelling which disrupt normal bone architecture, leading to expansion and reduced mechanical strength of affected bones. This can lead to various complications including deformity, fracture, nerve compression syndromes, and osteoarthritis, although many patients are asymptomatic. Genetic factors play a key role in the pathogenesis of PDB. This seems to be mediated by a combination of rare genetic variants which cause familial forms of the disease and common variants which increase susceptibility to environmental triggers. Environmental factors which have been suggested to predispose to PDB include viral infections, calcium and vitamin D deficiency, and excessive mechanical loading of affected bones. The diagnosis can be made by the characteristic changes seen on radiographs, but isotope bone scans are helpful in defining disease extent. Serum alkaline phosphatase levels can be used as a measure of disease activity. Inhibitors of bone resorption are the mainstay of medical management for PDB and bisphosphonates are regarded as the treatment of choice. Bisphosphonates are highly effective at reducing bone turnover in PDB and have been found to heal osteolytic lesions, and normalize bone histology. Although bisphosphonates can improving bone pain caused by elevated bone turnover, most patients require additional therapy to deal with symptoms associated with disease complications. It is currently unclear whether bisphosphonate therapy is effective at preventing complications of PDB.
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Chang, Ellen T., and Hans-Olov Adami. Nasopharyngeal Cancer. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190676827.003.0008.

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The distinctive global incidence patterns and risk factors for nasopharyngeal carcinoma (NPC) make this a unique malignancy that represents an epidemiologic challenge. NPC is rare throughout most of the world but relatively common in southern China, Southeast Asia, the Arctic, North Africa, and the Middle East. This pattern is determined in part by the geographic and ethnic distribution of established risk factors for NPC, which include early/aberrant Epstein Barr virus infection, Chinese-style salted fish consumption, family history, certain human leukocyte antigen alleles, and tobacco smoking. Other possible NPC risk factors include certain dietary, occupational, and infectious exposures and genetic variants. Risk factors for NPC in low-incidence regions, where tumors are more often of squamous cell histology than in high-incidence regions, are poorly understood, as are etiologic interactions among genetic, environmental, and infectious risk factors for NPC.
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Book chapters on the topic "Variants viraux"

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Bonino, F., and M. R. Brunetto. "Variants of hepatitis B virus." In Chronically Evolving Viral Hepatitis. Springer Vienna, 1992. http://dx.doi.org/10.1007/978-3-7091-5633-9_17.

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Jazayeri, Seyed Mohammad, Seyed Moayed Alavian, Payam Dindoost, Howard C. Thomas, and Peter Karayiannis. "Molecular Variants of Hepatitis B Surface Antigen (HBsAg)." In Viral Hepatitis. John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118637272.ch8.

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Miska, S., and H. Will. "Hepatitis B virus C-gene variants." In Research in Chronic Viral Hepatitis. Springer Vienna, 1993. http://dx.doi.org/10.1007/978-3-7091-9312-9_16.

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Sixbey, J. W. "Epstein-Barr Virus Variants at Mucosal Surfaces." In Epstein-Barr Virus and Human Disease • 1990. Humana Press, 1991. http://dx.doi.org/10.1007/978-1-4612-0405-3_22.

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Khalid, Sakib, and Jeffrey S. Crippin. "Cholestatic Variants of Viral Disease and Alcohol." In Cholestatic Liver Disease. Humana Press, 2008. http://dx.doi.org/10.1007/978-1-59745-118-5_7.

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Atia, Mary A., and Bashar Aqel. "Cholestatic Variants of Viral Disease and Alcohol." In Clinical Gastroenterology. Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1013-7_7.

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Gauntt, Charles J. "The Possible Role of Viral Variants in Pathogenesis." In Coxsackieviruses. Springer US, 1988. http://dx.doi.org/10.1007/978-1-4757-0247-7_10.

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Karayiannis, Peter, William F. Carman, and Howard C. Thomas. "Molecular Variants of the Precore, Core, and Core Promoter Regions of Hepatitis B Virus, and Their Clinical Significance." In Viral Hepatitis. John Wiley & Sons, Ltd, 2013. http://dx.doi.org/10.1002/9781118637272.ch9.

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Maekawa, Shinya, Mitsuaki Sato, and Nobuyuki Enomoto. "Detection of Antiviral Drug-Resistant Variants in Chronic Hepatitis C by Deep Sequencing." In Hepatitis C Virus Treatment. Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-2416-0_5.

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Davelaar, F. G., B. Kouwenhoven, and A. G. Burger. "The Diagnosis and Control of Infectious Bronchitis Variant Infections." In Acute Virus Infections of Poultry. Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4287-5_11.

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Conference papers on the topic "Variants viraux"

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Benslimane, Fatiha M., Hebah Al Khatib, Dana Albatesh, et al. "Nanopore Sequencing SARS-CoV-2 Genome in Qatar." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0289.

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Background: The current pandemic, COVID-19, is cause by an RNA Coronavirus that was recently identified as SARS-CoV-2. RNA viruses tend to have a high mutation rate; the rate is around a million times greater than that of their hosts. The mutagenic potential of the virus depends on many factors, including the fidelity of nucleic acid-replicating viral enzymes, such as SARSCoV-2 RNA dependent RNA polymerase (RdRp). The rate of mutation drives viral evolution and genome variability, consequently allowing viruses to escape the immunity of the host and develop resistance to drugs. Therefore, the characterization of SARS-CoV-2 variants might lead to implement better therapeutics treatments, vaccines design and identify new diagnostics approaches. Aim: The aim of this study was to establish a fast sequencing method to identify SARS-CoV-2 mutations in Qatar. This will help to assess if there are new viral variants that are spreading in country. Methods: RNA was isolated from samples collected from Qatar COVID-19 positive patients. The Artic Network V3 primer scheme and Oxford Nanopore ligation sequencing kit were used to prepare the sequencing libraries. Libraries were loaded on to R9.4.1 flow cells and ran on a GridION. Bioinformatics analysis was done following the Artic Network SARA-CoV-2 bioinformatics tools. Results: Genome coverage of sequenced samples was >80% and the depth was average at 200x. The coverage was highly dependable on sample viral load; samples of CT value lower than 30 resulted in better sequence coverage. The sequenced genomes were deposited in GISAID and were mainly clustering with genomes deposited from the UK. Sequences were compared to Illumina and sanger sequences and they showed compatible results. Conclusion: The use of ONT to sequence SARA-CoV-2 is a quick, affordable, and reliable technique to determine viral mutation. Using this technique, the first sequences from Qatar were deposited in to GISAID. Up to date, 700 genomes have been sequenced from Qatari samples.
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Wu, Jiaying, Xuewu Zhang, Xiaobo Zhu, and Xiaolong Xu. "A Variant SIRS Virus Spreading Model." In 2017 International Conference on Computer Systems, Electronics and Control (ICCSEC). IEEE, 2017. http://dx.doi.org/10.1109/iccsec.2017.8446753.

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Campo, David S., Zoya Dimitrova, Pavel Skums, and Yury Khudyakov. "Mutational robustness of hepatitis C virus intra-host variants." In 2013 IEEE 3rd International Conference on Computational Advances in Bio and Medical Sciences (ICCABS). IEEE, 2013. http://dx.doi.org/10.1109/iccabs.2013.6629229.

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Artyomenko, Alexander, Serghei Mangul, Nicholas C. Wu, Eleazar Eskin, Ren Sun, and Alex Zelikovsky. "Reconstruction of influenza a virus variants from PacBio reads." In 2014 IEEE 4th International Conference on Computational Advances in Bio and Medical Sciences (ICCABS). IEEE, 2014. http://dx.doi.org/10.1109/iccabs.2014.6863935.

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Acosta-Leal, Rodolfo, Becky Bryan, and Charlie M. Rush. "Host and viral factors that promote the emergence of resistance breaking variants of Beet necrotic yellow vein virus (BNYW)." In American Society of Sugar Beet Technologist. ASSBT, 2007. http://dx.doi.org/10.5274/assbt.2007.39.

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Al Khatib, Hebah A., Fatiha M. Benslimane, Israa El Bashir, Asmaa A. Al Thani, and Hadi M. Yassine. "Within-Host Diversity of SARS-Cov-2 in COVID-19 Patients with Variable Disease Severities." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0280.

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Background: The ongoing pandemic of SARS-COV-2 has already infected more than eight million people worldwide. The majority of COVID-19 patients are either asymptomatic or have mild symptoms. Yet, about 15% of the cases experience severe complications and require intensive care. Factors determining disease severity are not yet fully characterized. Aim: Here, we investigated the within-host virus diversity in COVID-19 patients with different clinical manifestations. Methods: We compared SARS-COV-2 genetic diversity in 19 mild and 27 severe cases. Viral RNA was extracted from nasopharyngeal samples and sequenced using Illumina MiSeq platform. This was followed by deep-sequencing analyses of SARS-CoV-2 genomes at both consensus and sub-consensus sequence levels. Results: Consensus sequences of all viruses were very similar, showing more than 99·8% sequence identity regardless of the disease severity. However, the sub-consensus analysis revealed significant differences in within-host diversity between mild and severe cases. Patients with severe symptoms exhibited a significantly (p-value 0.001) higher number of variants in coding and non-coding regions compared to mild cases. Analysis also revealed higher prevalence of some variants among severe cases. Most importantly, severe cases exhibited significantly higher within-host diversity (mean= 13) compared to mild cases (mean=6). Further, higher within-host diversity was observed in patients above the age of 60 compared to the younger age group. Conclusion: These observations provided evidence that within-host diversity might play a role in the development of severe disease outcomes in COVID19 patients; however, further investigations is required to elucidate this association.
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Naidu, Vijay, and Ajit Narayanan. "Needleman-Wunsch and Smith-Waterman Algorithms for Identifying Viral Polymorphic Malware Variants." In 2016 IEEE 14th Intl Conf on Dependable, Autonomic and Secure Computing, 14th Intl Conf on Pervasive Intelligence and Computing, 2nd Intl Conf on Big Data Intelligence and Computing and Cyber Science and Technology Congress(DASC/PiCom/DataCom/CyberSciTech)2016. IEEE, 2016. http://dx.doi.org/10.1109/dasc-picom-datacom-cyberscitec.2016.73.

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Campo, David S., Zoya Dimitrova, Guo-Liang Xia, Pavel Skums, Lilia Ganova-Raeva, and Yury Khudyakov. "New computational methods for assessing the genetic relatedness of close viral variants." In 2014 IEEE 4th International Conference on Computational Advances in Bio and Medical Sciences (ICCABS). IEEE, 2014. http://dx.doi.org/10.1109/iccabs.2014.6863937.

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Mendoza Meza, Magno Enrique. "Variant of Wodarz and Nowak's virus dynamics model subject to switching input." In 11TH INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2013: ICNAAM 2013. AIP, 2013. http://dx.doi.org/10.1063/1.4825881.

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Sarver, Nava, and George A. Ricca. "SUSTAINED EXPRESSION OF FULL LENGTH AND VARIANT RECOMBINANT FACTOR VIII IN GENETICALLY ENGINEERED CELLS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643875.

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A major effort is presently underway to provide factor VIII (FVIII) in a form free of viral pathogens via a recombinant DNA approach. We have constructed two chimeric FVIII cDNA vectors based on the bovine papillomavirus mammalian expression system. The first vector (FVIII) contained a full length FVIII cDNA; the second vector (AFVIII) contained a cDNA insert with an extensive deletion, corresponding to amino acid residues 747 to 1560 in the region encoding the "B" domain. This internal region is removed during activation of the parental FVIII molecule and is believed not to be required for coagulant activity. We have found that recombinant FVIII produced by stable cell lines harboring either the full length or the variant FVIII was capable of restoring coagulant activity to FVIII deficient plasma in. vitro. This expressed activity was neutralized by anti-FVIII antibodies. Similar to observations with FVIII derived from human plasma, the two recombinant FVIII forms were (i) inactivated by the chelating agent EDTA, (ii) demonstrated a biphasic response of an initial activation followed by a decay in activity when treated with thrombin, and (iii) presented the expected peptide banding pattern by western blot analyses. A higher percentage of ΔFVIII transformants were isolated expressing coagulant activity compared to transformants harboring the complete FVIII cDNA. Among the positive transformants isolated, those harboring ΔFVIII produced higher levels of coagulant activity than their full length counterparts. Comparable steady state levels of FVIII specific transcripts were detected in FVIII and ΔFVIII transformants indicating that the difference in expression levels is due to a post transcriptional event(s). Our study demonstrates the efficacy of a full length and an abridged recombinant FVIII produced by stably transformed cells in correcting coagulation deficiency in. vitro. It further suggests the potential usefulness of other molecular variants for efficient expression in genetically engineered cells.
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Reports on the topic "Variants viraux"

1

Fernández-Villaverde, Jesús, Pablo Guerrón-Quintana, and Juan Rubio-Ramírez. Fortune or Virtue: Time-Variant Volatilities Versus Parameter Drifting in U.S. Data. National Bureau of Economic Research, 2010. http://dx.doi.org/10.3386/w15928.

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