Search results for "RAS"
showing 10 items of 26429 documents
Biochemical properties of hepatitis C virus NS5B RNA-dependent RNA polymerase and identification of amino acid sequence motifs essential for enzymati…
1997
The NS5B protein of the hepatitis C virus (HCV) is an RNA-dependent RNA polymerase (RdRp) (S.-E. Behrens, L. Tomei, and R. De Francesco, EMBO J. 15:12-22, 1996) that is assumed to be required for replication of the viral genome. To further study the biochemical and structural properties of this enzyme, an NS5B-hexahistidine fusion protein was expressed with recombinant baculoviruses in insect cells and purified to near homogeneity. The enzyme was found to have a primer-dependent RdRp activity that was able to copy a complete in vitro-transcribed HCV genome in the absence of additional viral or cellular factors. Filter binding assays and competition experiments showed that the purified enzym…
The Extracellular δ-Domain is Essential for the Formation of CD81 Tetraspanin Webs
2014
AbstractCD81 is a ubiquitously expressed member of the tetraspanin family. It forms large molecular platforms, so-called tetraspanin webs that play physiological roles in a variety of cellular functions and are involved in viral and parasite infections. We have investigated which part of the CD81 molecule is required for the formation of domains in the cell membranes of T-cells and hepatocytes. Surprisingly, we find that large CD81 platforms assemble via the short extracellular δ-domain, independent from a strong primary partner binding and from weak interactions mediated by palmitoylation. The δ-domain is also essential for the platforms to function during viral entry. We propose that, ins…
Rapid and sensitive detection of metapneumovirus in clinical specimens by indirect fluorescence assay using a monoclonal antibody.
2008
Human metapneumovirus, with two known genotypes named A and B, is associated with mild respiratory symptoms to severe LRTI in children, high-risk adults and the elderly. Rapid and reliable methods of hMPV detection in clinical samples are essential to implement appropriate care, to better understand the pathology of hMPV and to determine its epidemiology. Respiratory samples from 1,386 patients collected during 2 consecutive years were screened for hMPV using indirect immunofluorescence (IFA) assay with a monoclonal antibody. Forty-three patients tested positive for hMPV by the IFA method. In parallel, the samples were examined with RT-PCR on the F gene. Of these, 41 specimens were RT-PCR p…
Characterization of the autoantigen La (SS-B) as a dsRNA unwinding enzyme
1997
During the analysis of the La (SS-B) autoantigen for catalytic activities an ATP-dependent double-stranded RNA unwinding activity was detected. Both native and recombinant La proteins from different species displayed this activity, which could be inhibited by monospecific anti-La antibodies. La protein was able to melt dsRNA substrates with either two 3'-overhangs or a single 3'- and a 5'-overhang. Double-stranded RNAs with two 5'-overhangs were not unwound, indicating that at least one 3'-overhang is required for unwinding. Sequence elements of the La protein that might be involved in dsRNA unwinding, such as an evolutionarily conserved putative ATP-binding motif and an element that is hom…
Clathrin- and Caveolin-Independent Entry of Human Papillomavirus Type 16—Involvement of Tetraspanin-Enriched Microdomains (TEMs)
2008
BACKGROUND: Infectious entry of human papillomaviruses into their host cells is an important step in the viral life cycle. For cell binding these viruses use proteoglycans as initial attachment sites. Subsequent transfer to a secondary receptor molecule seems to be involved in virus uptake. Depending on the papillomavirus subtype, it has been reported that entry occurs by clathrin- or caveolin-mediated mechanisms. Regarding human papillomavirus type 16 (HPV16), the primary etiologic agent for development of cervical cancer, clathrin-mediated endocytosis was described as infectious entry pathway. METHODOLOGY/PRINCIPAL FINDINGS: Using immunofluorescence and infection studies we show in contra…
A single tube PCR assay for detecting viruses and their recombinants that cause tomato yellow leaf curl disease in Mediterranean basin
2007
Tomato yellow leaf curl disease (TYLCD) is well known in Mediterranean countries, where it has been causing severe losses in tomato crops for decades. Until recently, two viruses (with several isolates) in the genus Begomovirus, family Geminiviridae, have been associated with the epidemics: Tomato yellow leaf curl virus (TYLCV) and Tomato yellow leaf curl Sardinia virus (TYLCSV). However, recombinants between these, such as Tomato yellow leaf curl Malaga virus (TYLCMalV), are spreading, and new methods for detecting all viruses present in the region are needed. By considering all DNA sequences available of viruses causing TYLCD in the Mediterranean basin, a PCR/RFLP protocol was developed t…
Tiešsaistes apdrošināšanas platformas optimizācija
2018
Vispārīgā datu aizsardzības regula (VDAR) ir paredzēta datu aizsardzībai un privātuma nodrošināšanai visiem pilsoņiem, kas dzīvo Eiropas Savienības valstīs. Viena no šīs regulas prasībām ir datu subjektu pieprasījums (DSP), kas paredz kādas organizācijas pakalpojumu lietotājam pieprasīt par sevi vāktos datus, kas glabājas organizācijā. Arī tiešsaistes apdrošināšanas platformai Bamboo, kas tiek izstrādāta uzņēmumā, ir jānodrošina tās klientiem iegūt par sevi uzglabātos datus. Pašlaik tas tiek nodrošināts manuāli, ejot cauri visiem dokumentiem un lejupielādējot tos pa vienam. Tādēļ šī darba mērķis ir optimizēt platformu un atvieglot darbu zvanu centra darbiniekiem, kas pārvalda klientu datus …
AnatomySketch : An Extensible Open-Source Software Platform for Medical Image Analysis Algorithm Development
2021
AbstractThe development of medical image analysis algorithm is a complex process including the multiple sub-steps of model training, data visualization, human–computer interaction and graphical user interface (GUI) construction. To accelerate the development process, algorithm developers need a software tool to assist with all the sub-steps so that they can focus on the core function implementation. Especially, for the development of deep learning (DL) algorithms, a software tool supporting training data annotation and GUI construction is highly desired. In this work, we constructed AnatomySketch, an extensible open-source software platform with a friendly GUI and a flexible plugin interfac…
5-6 gadu vecu bērnu saskarsmes prasmju veicināšana kultūras un pašizpausmes jomas nodarbībās pirmsskolā
2020
Teorētiskajā daļā tiek izskatīts jēdziens par saskarsmes prasmēm, ko tās ietekmē un kā labāk tās veicināt. Kvalifikācijas darbā tiek aplūkots teorētiskais pamatojums saskarsmes prasmju veicināšanai 5-6 gadus veciem bērniem kultūras un pašizpausmes jomā. Kā arī veikts empīriskais pētījums, kurā tika pielietota novērošana un izglītojamo darbības rezultātu izpēte. Balstoties uz vairāku autoru atziņām par saskarsmes prasmēm, tika izvirzīti saskarsmes prasmes kritēriji. Pēc šiem kritērijiem tika izvērtēti bērni piecu integrēto vizuālās mākslas nodarbību laikā. Pirmreizējās novērošanas rezultāti tika apkopoti un analizēti. Balstoties uz teorētiskā pamatojuma, kvalifikācijas darba autore izstrādāj…
Populāro tēlu izmantošana klasisko mākslas tehniku apguvē interešu izglītībā
2021
Skolotāja pieredzes darbā „Populāro tēlu izmantošana klasisko mākslas tehniku apguvē interešu izglītībā” ir apkopota un izvērtēta pieredze, kas iegūta darba autorei organizējot un vadot vizuālās mākslas nodarbības pēc savas izstrādātas programmas “Anime zīmēšanas stils” pusaudžu vecuma bērniem. Izstrādāto programmu pamato teorētiskā izpēte par pētījuma priekšmetam atbilstošām tēmām – mākslas nozīmi izglītībā, klasisko mākslas tehniku apguves iespējām, mācību organizācijas veidu interešu izglītībā un pusaudžu vecumposmu. Teorētiskā izpēte aprakstīta darba pirmajā daļā. Darba autores – pasniedzējas izvirzītais uzdevums ir organizēt mācību procesu tādā veidā, lai kā priekšrocību mākslas nodarb…