446 research outputs found
Innovation and productivity growth in the EU services sector
Research and development; innovation; neoclassical growth model; endogeneous growth; services
Defined mutations in the 5' nontranslated sequence of Sindbis virus RNA
We have constructed 24 deletion mutants which contain deletions of from 1 to 15 nucleotides in the 5' nontranslated region of Sindbis virus RNA and tested the effect of these mutations on virus replication. The results showed that the first 44 nucleotides, which are capable of forming a hairpin structure, are important for virus replication, as all deletions tested in this region were either lethal or resulted in virus that grew poorly in comparison to the parental virus. Many of these deletions had different effects in mosquito cells than in chicken cells, suggesting that cellular factors, presumably proteins, bind to this region. This domain may function in at least two processes in viral replication. It seems likely that in the minus strand, this sequence element is bound by the viral replicase and promotes RNA replication. In the plus strand, this element may modulate initiation of translation of the nonstructural proteins. The results suggest that the hairpin structure itself is important. All deletions within it had deleterious effects on virus replication, and in particular, deletion of one of the G residues at nucleotide 7 or 8 or of one of the C residues at nucleotide 36 or 37 which are theoretically base-paired with these G's resulted in temperature-sensitive viruses that behaved very similarly. In contrast, large deletions between the 44-nucleotide hairpin and the translation start site at nucleotides 60 to 62 resulted in virus that grew as well as or better than the parental virus in both chicken and mosquito cells. The A residue at position 5 of the HRSP strain used was examined in more detail. Deletion of this A was lethal, whereas substitution by G resulted in a virus that grew poorly, despite the fact that G is present at position 5 in the AR339 parent of HRSP. U at position 5 resulted in a virus that grew less well than the A5 strain but better than the G5 mutant
Mutagenesis of the conserved 51-nucleotide region of Sindbis virus
We have constructed 25 site-specific mutations in a domain of 51 nucleotides in Sindbis virus that is highly conserved among all alphaviruses sequenced to date. These 51 nucleotides are capable of forming two hairpin structures and are found from nucleotides 155 to 205 in Sindbis virus within the region encoding nsP1. Of the mutations, 21 were silent and did not lead to a change in the amino acid sequence encoded. These silent mutations changed not only the linear sequence but also the stability of the hairpins in most cases. Two double mutants that were constructed led to the replacement of one base pair by another so that the linear sequence was altered but the nature of the hairpins was not. All of the mutants with silent mutations were viable, but 19 of the 21 mutants were severely impaired for growth in both chicken and mosquito cells. Compared with the parental virus, they grew slowly and produced virus at rates of 10(-1) to 10(-4) times the parental rate. Surprisingly, however, the plaques produced by these mutants were indistinguishable from those produced by the parental virus. Two of the silent mutations, found within the first hairpin structure, produced virus at a faster rate than the parental virus. It is clear that the exact sequence of this region is important for some aspect of virus replication. We suggest that one or more proteins, either virus encoded or cellular, bind to the hairpin structures in a sequence-specific fashion in a step that promotes replication of the viral RNA. Of the mutations that resulted in a change of coding, only one of four was viable, suggesting that the amino acid sequence encoded in this domain is essential for virus replication
Financing infrastructure
A review of the 2010 EIB Conference in Economics and Financeinfrastructure; public investment; corporate investment; investment funds
Business R&D expenditure and capital in Europe
This study presents new estimates of business R&D capital stocks for 22 countries at the aggregate and industry levels. At 9 percent of GDP, the EU business R&D capital stock falls short of its US and Japanese counterparts. Within the EU, R&D capital stocks are much lower in the southern and the new member states, reflecting large and persistent disparities in R&D expenditure. There was hardly any convergence over the past decade. The R&D capital stock is concentrated on three technologyintensive manufacturing industries and is positively correlated with growth in total factor productivity across countries and industries. Finally, the ratios between the stocks of R&D capital and tangible capital suggest marked differences in how R&D and tangible capital are combined in production.R&D capital stock; R&D expenditure; tangible capital stock; R&D intensity; high-tech manufacturing
Attenuation of Sindbis virus neurovirulence by using defined mutations in nontranslated regions of the genome RNA
A New Survey for Giant Arcs
We report on the first results of an imaging survey to detect strong
gravitational lensing targeting the richest clusters selected from the
photometric data of the Sloan Digital Sky Survey (SDSS) with follow-up deep
imaging observations from the Wisconsin Indiana Yale NOAO (WIYN) 3.5m telescope
and the University of Hawaii 88-inch telescope (UH88). The clusters are
selected from an area of 8000 deg^2 using the Red Cluster Sequence technique
and span the redshift range 0.1 < z < 0.6, corresponding to a comoving
cosmological volume of ~ 2 Gpc^3. Our imaging survey thus targets a volume more
than an order of magnitude larger than any previous search. A total of 240
clusters were imaged of which 141 had sub-arcsecond image quality. Our survey
has uncovered16 new lensing clusters with definite giant arcs, an additional 12
systems for which the lensing interpretation is very likely, and 9 possible
lenses which contain shorter arclets or candidate arcs which are less certain
and will require further observations to confirm their lensing origin. The
number of new cluster lenses detected in this survey is likely > 30. Among
these new systems are several of the most dramatic examples of strong
gravitational lensing ever discovered with multiple bright arcs at large
angular separation. These will likely become 'poster-child' gravitational
lenses similar to Abell 1689 and CL0024+1654. The new lenses discovered in this
survey will enable future sysetmatic studies of the statistics of strong
lensing and its implications for cosmology and our structure formation
paradigm.Comment: 19 pages, 7 pages of Figures, submitted to AJ. Fixed Typo
SPAG17 Mediates Nuclear Translocation of Protamines During Spermiogenesis
Protamines (PRM1 and PRM2) are small, arginine-rich, nuclear proteins that replace histones in the final stages of spermiogenesis, ensuring chromatin compaction and nuclear remodeling. Defects in protamination lead to increased DNA fragmentation and reduced male fertility. Since efficient sperm production requires the translocation of protamines from the cytoplasm to the nucleus, we investigated whether SPAG17, a protein crucial for intracellular protein trafficking during spermiogenesis, participates in protamine transport. Initially, we assessed the protein-protein interaction between SPAG17 and protamines using proximity ligation assays, revealing a significant interaction originating in the cytoplasm and persisting within the nucleus. Subsequently, immunoprecipitation and mass spectrometry (IP/MS) assays validated this initial observation. Sperm and spermatids fro
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