352 research outputs found
The Euro changeover and price adjustments in Italy
By estimating a staggered price model over the period 1980q1-2010q2, this paper documents that, after the euro changeover, Italian retailers have increased the number of price adjustments, which has translated into a higher inflation rate, with a detrimental effect on the competitiveness of the Italian economy
The Euro Changeover and Price Adjustments in Italy
By estimating a staggered price model over the period 1980q1-2010q2, this paper documents that, after the euro changeover, Italian retailers have increased the number of price adjustments, which has translated into a higher inflation rate, with a detrimental effect on the competitiveness of the Italian economy.Euro changeover, staggered price adjustments, inflation
The Euro Changeover and Price Adjustments in Italy
By estimating a staggered price model over the period 1980q1-2010q2, this paper documents that, after the euro changeover, Italian retailers have increased the number of price adjustments, which has translated into a higher inflation rate, with a detrimental effect on the competitiveness of the Italian economyEuro changeover, staggered price adjustments, inflation
From Chirps to Random-FM Excitations in Pulse Compression Ultrasound Systems
Pulse compression is often practiced in ultrasound Non Destructive Testing
(NDT) systems using chirps. However, chirps are inadequate for setups where
multiple probes need to operate concurrently in Multiple Input Multiple Output
(MIMO) arrangements. Conversely, many coded excitation systems designed for
MIMO miss some chirp advantages (constant envelope excitation, easiness of
bandwidth control, etc.) and may not be easily implemented on hardware
originally conceived for chirp excitations. Here, we propose a system based on
random-FM excitations, capable of enabling MIMO with minimal changes with
respect to a chirp-based setup. Following recent results, we show that
random-FM excitations retain many advantages of chirps and provide the ability
to frequency-shape the excitations matching the transducers features.Comment: 4 pages, 4 figures. Post-print from conference proceedings. Note that
paper in conference proceedings at http://dx.doi.org/10.1109/ULTSYM.2012.0117
has some rendering issue
Mutations in the Schmallenberg virus Gc glycoprotein facilitate cellular protein synthesis shutoff and restore pathogenicity of NSs deletion mutants in mice
Serial passage of viruses in cell culture has been traditionally used to attenuate virulence and identify determinants of viral pathogenesis. In a previous study, we found that a strain of Schmallenberg virus (SBV) serially passaged in tissue culture (termed SBVp32) unexpectedly displayed increased pathogenicity in suckling mice compared to wild type SBV. In this study, we mapped the determinants of SBVp32 virulence to the viral genome M segment. SBVp32 virulence is associated with the capacity of this virus to reach higher titers in the brains of experimentally infected suckling mice. We also found that the Gc glycoprotein, encoded by the M segment of SBVp32, facilitates host cell protein shutoff in vitro. Interestingly, while the M segment of SBVp32 is a virulence factor, we found that the S segment of the same virus confers by itself an attenuated phenotype to wild type SBV as has lost the ability to block the innate immune system of the host. Single mutations present in the Gc glycoprotein of SBVp32 are sufficient to compensate both the attenuated phenotype of the SBVp32 S segment and the attenuated phenotype of NSs deletion mutants. Our data also indicate that the SBVp32 M segment does not act as an IFN antagonist. Therefore SBV mutants can retain pathogenicity even when they are unable to fully control the production of IFN by the infected cells. Overall, this study suggests that the viral glycoprotein of orthobunyaviruses can compensate, at least in part, the function of NSs. In addition, we also provide evidence that the induction of total cellular protein shutoff by SBV is determined by multiple viral proteins while the ability to control the production of IFN maps to the NSs protein.
Importance The identification of viral determinants of pathogenesis is key to the development of prophylactic and interventions measures. In this study we found that the bunyavirus Gc glycoprotein is a virulence factor. Importantly, we show that mutations in the Gc glycoprotein can restore pathogenicity of attenuated mutants resulting from deletions or mutations in the non-structural protein NSs. Our findings highlight the fact that careful consideration should be taken when designing live attenuated vaccines based on deletions of non-structural proteins since single mutations in the viral glycoproteins appear to revert attenuated mutants to virulent phenotypes
NSs protein of Schmallenberg virus counteracts the antiviral response of the cell by inhibiting its transcriptional machinery
Bunyaviruses have evolved a variety of strategies to counteract the antiviral defence systems of mammalian cells. Here we show that the NSs protein of Schmallenberg virus (SBV) induces the degradation of the RPB1 subunit of RNA polymerase II and consequently inhibits global cellular protein synthesis and the antiviral response. In addition, we show that the SBV NSs protein enhances apoptosis in vitro and possibly in vivo, suggesting that this protein could be involved in SBV pathogenesis in different ways
Virus and host factors affecting the clinical outcome of bluetongue virus infection
Bluetongue is a major infectious disease of ruminants caused by bluetongue virus (BTV), an arbovirus transmitted by Culicoides. Here, we assessed virus and host factors influencing the clinical outcome of BTV infection using a single experimental framework. We investigated how mammalian host species, breed, age, BTV serotypes, and strains within a serotype, affect the clinical course of bluetongue. Results obtained indicate that in small ruminants there is a marked difference in the susceptibility to clinical disease induced by BTV at the host species level, but less so at the breed level. No major differences in virulence were found between divergent serotypes (BTV-8 and BTV-2). However, we observed striking differences in virulence between closely related strains of the same serotype collected towards the beginning and the end of the European BTV-8 outbreak. As observed previously, differences in disease severity were also observed when animals were infected with either blood from a BTV-infected animal or from the same virus isolated in cell culture. Interestingly, with the exception of two silent mutations, full viral genome sequencing showed identical consensus sequences of the virus before and after cell culture isolation. However, deep sequencing analysis revealed a marked decrease in the genetic diversity of the viral population after passaging in mammalian cells. In contrast, passaging in Culicoides cells increased the overall number of low frequency variants compared to virus never passaged in cell culture. Thus, Culicoides might be a source of new viral variants and viral population diversity can be another factor influencing BTV virulence
Characterization of a second open reading frame in genome segment 10 of bluetongue virus
Viruses have often evolved overlapping reading frames in order to maximise their coding capacity. Until recently, the segmented double-stranded (ds) RNA genome of viruses of the Orbivirus genus was thought to be monocistronic but the identification of the bluetongue virus (BTV) NS4 protein changed this assumption. A small open reading frame (ORF) in segment 10, overlapping the NS3 ORF in the +1 position that is maintained in more than 300 strains of the 26 different BTV serotypes and in more of 200 strains of the phylogenetically related African horse sickness (AHSV). In BTV, this ORF (named S10-ORF2 in this study) encodes a putative protein of 50-59 amino acid residues in length and appears to be under a strong positive selection. HA- or GFP-tagged versions of S10-ORF2 expressed from transfected plasmids localised within the nucleoli of transfected cells unless a putative nucleolar localisation signal was mutated S10-ORF2 inhibited gene expression, but not RNA translation, in transient transfection reporter assays. In both mammalian and insect cells, BTV S10-ORF2 deletion mutants (BTV8ΔS10-ORF2) displayed similar replication kinetics to wild type virus. In vivo, S10-ORF2 deletion mutants were pathogenic in mouse models of disease. Although further evidence is required for S10-ORF2 expression during infection, the data presented provide an initial characterisation of this open reading frame
Ottimizzazione della selezione dei decadimenti Λ 0 b → pK− e Λ 0 b → pπ− per la misura delle asimmetrie di CP
In questa tesi è presentato il lavoro svolto per ottimizzare le selezioni dei decadimenti Λ 0 b → pK− e Λ 0 b → pπ− al fine di misurarne le asimmetrie di CP. Il campione di dati utilizzato corrisponde ad una luminosità integrata di 6 fb−1, raccolto dall'esperimento LHCb in collisioni protone-protone ad un'energia nel centro di massa di 13 TeV. L'ottimizzazione della selezione è di fondamentale importanza nello studio di questi decadimenti, per ottenere la minor incertezza statistica possibile sulle asimmetrie misurate. Il lavoro svolto in questa tesi ha portato ad avere incertezze statistiche sulle singole asimmetrie di CP pari a: σ(A pK CP ) = 0.76%, σ(A pπ CP) = 0.95%, che risultano essere minori di circa un fattore due rispetto ai risultati già pubblicati dalla Collaborazione LHCb. Il lavoro svolto in questa tesi sarà parte della pubblicazione dei risultati ottenuti su rivista internazionale, prevista per il 202
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