98 research outputs found
Additive Polynomials for Finite Groups of Lie Type
This paper provides a realization of all classical and most exceptional
finite groups of Lie type as Galois groups over function fields over F_q and
derives explicit additive polynomials for the extensions. Our unified approach
is based on results of Matzat which give bounds for Galois groups of Frobenius
modules and uses the structure and representation theory of the corresponding
connected linear algebraic groups.Comment: 59 pages; v2: added reference, slightly restructured section 6.1, few
small rewordings; v3: completed realization of Steinberg's triality groups
(thanks to P. Mueller for solving the remaining open question); clarified
argument how to use Thm. 3.
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Epstein-Barr virus: clinical and epidemiological revisits and genetic basis of oncogenesis
Epstein-Barr virus (EBV) is classified as a member in the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae and the genus lymphocytovirus. The virus is an exclusively human pathogen and thus also termed as human herpesvirus 4 (HHV4). It was the first oncogenic virus recognized and has been incriminated in the causation of tumors of both lymphatic and epithelial nature. It was reported in some previous studies that 95% of the population worldwide are serologically positive to the virus. Clinically, EBV primary infection is almost silent, persisting as a life-long asymptomatic latent infection in B cells although it may be responsible for a transient clinical syndrome called infectious mononucleosis. Following reactivation of the virus from latency due to immunocompromised status, EBV was found to be associated with several tumors. EBV linked to oncogenesis as detected in lymphoid tumors such as Burkitt's lymphoma (BL), Hodgkin's disease (HD), post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g. Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL). It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas and oral hairy leukoplakia (OHL). In vitro, EBV many studies have demonstrated its ability to transform B cells into lymphoblastoid cell lines (LCLs). Despite these malignancies showing different clinical and epidemiological patterns when studied, genetic studies have suggested that these EBV- associated transformations were characterized generally by low level of virus gene expression with only the latent virus proteins (LVPs) upregulated in both tumors and LCLs. In this review, we summarize some clinical and epidemiological features of EBV- associated tumors. We also discuss how EBV latent genes may lead to oncogenesis in the different clinical malignancie
SARS-CoV-2 variants of interest and concern naming scheme conducive for global discourse
A group convened and led by the Virus Evolution Working Group of the World Health Organization reports on its deliberations and announces a naming scheme that will enable clear communication about SARS-CoV-2 variants of interest and concern.Molecular basis of virus replication, viral pathogenesis and antiviral strategie
Parks, people, and conservation: A review of management issues in nepal's protected areas
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43480/1/11111_2005_Article_BF01254607.pd
The Coupling of Alternative Splicing and Nonsense-Mediated mRNA Decay
Most human genes exhibit alternative splicing, but not all alternatively spliced transcripts produce functional proteins. Computational and experimental results indicate that a substantial fraction of alternative splicing events in humans result in mRNA isoforms that harbor a premature termination codon (PTC). These transcripts are predicted to be degraded by the nonsense-mediated mRNA decay (NMD) pathway. One explanation for the abundance of PTC-containing isoforms is that they represent splicing errors that are identified and degraded by the NMD pathway. Another potential explanation for this startling observation is that cells may link alternative splicing and NMD to regulate the abundance of mRNA transcripts. This mechanism, which we call "Regulated Unproductive Splicing and Translation" (RUST), has been experimentally shown to regulate expression of a wide variety of genes in many organisms from yeast to human. It is frequently employed for autoregulation of proteins that affect the splicing process itself. Thus, alternative splicing and NMD act together to play an important role in regulating gene expression
K-Ar ages of intrusive rocks in the Oban-Obudu massif and their significance for the tectonic and plutonic history of southeastern Nigeria
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