239 research outputs found
Gaudio E., Tarricone L., Terregino C., Piccirillo. A."Screening for Avian Influenza and Paramyxovirus Type 1 in wild birds admitted to a rehabilitation centre in Veneto Region (Northern Italy): preliminary results", Proceedings of the International Conference on Diseases of Zoo and Wild Animal 2015, page 119, Barcelona, Spain (13/05/2015-16/05/2015).
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A systematic review of human coronaviruses survival on environmental surfaces
No full textThe current pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface disinfection and use of alcohol-based hand gel, in order to avoid viral transmission via fomites. However, the role of surface transmission is still debated. The present systematic review aims to summarize all the evidence on surface survival of coronaviruses infecting humans. The analysis of 18 studies showed the longest coronavirus survival time is 28 days at room temperature (RT) on different surfaces: polymer banknotes, vinyl, steel, glass, and paper banknotes. Concerning SARS-CoV-2 human infection from contaminated surfaces, dangerous viral load on surfaces for up to 21 days was determined on polymer banknotes, steel, glass and paper banknotes. For viruses other than SARS-CoV-2, the longest period of survival was 14 days, recorded on glass. Environmental conditions can affect virus survival, and indeed, low temperatures and low humidity support prolonged survival of viruses on contaminated surfaces independently of surface type. Furthermore, it has been shown that exposure to sunlight significantly reduces the risk of surface transmission. Although studies are increasingly investigating the topic of coronavirus survival, it is difficult to compare them, given the methodology differences. For this reason, it is advisable to define a reference working protocol for virus survival trials, but, as an immediate measure, there is also a need for further investigations of coronavirus survival on surfaces
Viral Encephalopathy and Retinopathy in groupers (<it>Epinephelus</it> spp.) in southern Italy: a threat for wild endangered species?
No full textAbstract Background Betanodaviruses are the causative agents of Viral Encephalopathy and Retinopathy (VER). To date, more than 50 species have proved to be susceptible and among them, those found in genus Epinephelus are highly represented. Clinical disease outbreaks are generally characterized by typical nervous signs and significant mortalities mainly associated with aquaculture activities, although some concerns for the impact of this infection in wild fish have been raised. In this study, the authors present the first documented report describing an outbreak of VER in wild species in the Mediterranean basin. Case presentation In late summer - early winter 2011 (September-December), significant mortalities affecting wild Dusky grouper (Epinephelus marginatus), Golden grouper (Epinephelus costae) and European sea bass (Dicentrarchus labrax) were reported in the municipality of Santa Maria di Leuca (Northern Ionian Sea, Italy). The affected fish showed an abnormal swimming behavior and swollen abdomens. During this epizootic, five moribund fish showing clear neurological signs were captured and underwent laboratory investigations. Analytical results confirmed the diagnosis of VER in all the specimens. Genetic characterization classified all betanodavirus isolates as belonging to the RGNNV genotype, revealing a close genetic relationship with viral sequences obtained from diseased farmed fish reared in the same area in previous years. Conclusion The close relationship of the viral sequences between the isolates collected in wild affected fish and those isolated during clinical disease outbreaks in farmed fish in the same area in previous years suggests a persistent circulation of betanodaviruses and transmission between wild and farmed stocks. Further investigations are necessary to assess the risk of viral transmission between wild and farmed fish populations, particularly in marine protected areas where endangered species are present.</p
On the Calogero-Moser space associated with dihedral groups
No full textInternational audienceUsing the geometry of the associated Calogero-Moser space, R. Rouquier and the author have attached to any finite complex reflection group several notions (Calogero-Moser left, right or two-sided cells, Calogero-Moser cellular characters), completing the notion of Calogero-Moser families defined by Gordon. If moreover is a Coxeter group, they conjectured that these notions coincide with the analogous notions defined using the Hecke algebra by Kazhdan and Lusztig (or Lusztig in the unequal parameters case). In the present paper, we aim to investigate these conjectures whenever is a dihedral group
Occurrence of Chlamydiae in Corvids in Northeast Italy
No full textChlamydiaceae occurrence has been largely evaluated in wildlife, showing that wild birds
are efficient reservoirs for avian chlamydiosis. In this study, DNA extracted from cloacal swabs of
108 corvids from Northeast Italy was screened for Chlamydiaceae by 23S real-time (rt)PCR. The positive
samples were characterised by specific rtPCRs for Chlamydia psittaci, Chlamydia abortus, Chlamydia
gallinacea, Chlamydia avium, Chlamydia pecorum and Chlamydia suis. Cloacal shedding of Chlamydiaceae
was detected in 12 out of 108 (11.1%, 5.9%–18.6% 95% CI) corvids sampled. Molecular characterisation
at the species level was possible in 8/12 samples, showing C. psittaci positivity in only one sample
from a hooded crow and C. abortus positivity in seven samples, two from Eurasian magpies and five
from hooded crows. Genotyping of the C. psittaci-positive sample was undertaken via PCR/highresolution
melting, clustering it in group III_pigeon, corresponding to the B genotype based on former
ompA analysis. For C. abortus genotyping, multilocus sequence typing was successfully performed on
the two samples with high DNA load from Eurasian magpies, highlighting 100% identity with the
recently reported Polish avian C. abortus genotype 1V strain 15-58d44. To confirm the intermediate
characteristics between C. psittaci and C. abortus, both samples, as well as two samples from hooded
crows, showed the chlamydial plasmid inherent in most C. psittaci and avian C. abortus, but not in
ruminant C. abortus strains. The plasmid sequences were highly similar (99%) to those of the Polish
avian C. abortus genotype 1V strain 15-58d44. To our knowledge, this is the first report of avian
C. abortus strains in Italy, specifically genotype 1V, confirming that they are actively circulating in
corvids in the Italian region tested
Identification and genetic characterization of equine hepaciviruses in Italy
No full textViruses similar to human hepatitis C virus, hepaciviruses, have been identified in various animal species. Equine hepacivirus (EqHV) is the closest relative of human hepaciviruses. Although detected worldwide, information on EqHV epidemiology, genetic diversity and pathogenicity is still limited. In this study we investigated the prevalence and genetic diversity of EqHV in Italian equids. The RNA of EqHV was detected in 91/1932 sera (4.7%) whilst it was not detectable in 134 donkey sera screened by a TaqMan-based quantitative assay. Upon sequencing and phylogenetic analysis of genomic portions located in the NS5B, 5â 2UTR and NS3 genes, the Italian EqHV strains segregated into two distinct clades that are also co-circulating globally, without apparent geographic restrictions
Computational aspects of Calogero-Moser spaces
No full textInternational audienceWe present a series of algorithms for computing geometric and representationtheoretic invariants of Calogero-Moser spaces and rational Cherednik algebras associated with complex reflection groups. Especially, we are concerned with Calogero-Moser families (which correspond to the -fixed points of the Calogero-Moser space) and cellular characters (a proposed generalization by Rouquier and the first author of Lusztig's constructible characters based on a Galois covering of the Calogero-Moser space). To compute the former, we devised an algorithm for determining generators of the center of the rational Cherednik algebra (this algorithm has several further applications), and to compute the latter we developed an algorithmic approach to the construction of cellular characters via Gaudin operators. We have implemented all our algorithms in the Cherednik Algebra Magma Package (CHAMP) by the second author and used this to confirm open conjectures in several new cases. As an interesting application in birational geometry we are able to determine for many exceptional complex reflection groups the chamber decomposition of the movable cone of a Q-factorial terminalization (and thus the number of non-isomorphic relative minimal models) of the associated symplectic singularity
Computational aspects of Calogero-Moser spaces
No full textWe present a series of algorithms for computing geometric and
representation-theoretic invariants of Calogero-Moser spaces and rational
Cherednik algebras associated to complex reflection groups. Especially, we are
concerned with Calogero-Moser families (which correspond to the
-fixed points of the Calogero-Moser space) and cellular
characters (a proposed generalization by Rouquier and the first author of
Lusztig's constructible characters based on a Galois covering of the
Calogero-Moser space). To compute the former, we devised an algorithm for
determining generators of the center of the rational Cherednik algebra (this
algorithm has several further applications), and to compute the latter we
developed an algorithmic approach to the construction of cellular characters
via Gaudin operators. We have implemented all our algorithms in the Cherednik
Algebra Magma Package (CHAMP) by the second author and used this to confirm
open conjectures in several new cases. As an interesting application in
birational geometry we are able to determine for many exceptional complex
reflection groups the chamber decomposition of the movable cone of a
-factorial terminalization (and thus the number of non-isomorphic
relative minimal models) of the associated symplectic singularity.Comment: 42 page
Prevalence of SARS-CoV-2 RNA on inanimate surfaces: a systematic review and meta-analysis
No full textCoronavirus disease (COVID-19) is a respiratory disease affecting many people and able to be transmitted through direct and perhaps indirect contact. Direct contact transmission, mediated by aerosols or droplets, is widely demonstrated, whereas indirect transmission is only supported by collateral evidence such as virus persistence on inanimate surfaces and data from other similar viruses. The present systematic review aims to estimate SARS-CoV-2 prevalence on inanimate surfaces, identifying risk levels according to surface characteristics. Data were obtained from studies in published papers collected from two databases (PubMed and Embase) with the last search on 1 September 2020. Included studies had to be papers in English, had to deal with coronavirus and had to consider inanimate surfaces in real settings. Studies were coded according to our assessment of the risk that the investigated surfaces could be contaminated by SARS-CoV-2. A meta-analysis and a metaregression were carried out to quantify virus RNA prevalence and to identify important factors driving differences among studies. Thirty-nine out of forty retrieved paper reported studies carried out in healthcare settings on the prevalence of virus RNA, five studies carry out also analyses through cell culture and six tested the viability of isolated viruses. Overall prevalences of SARS-CoV-2 RNA on high-, medium- and low-risk surfaces were 0.22 (CI95 [0.152-0.296]), 0.04 (CI95 [0.007-0.090]), and 0.00 (CI95 [0.00-0.019]), respectively. The duration surfaces were exposed to virus sources (patients) was the main factor explaining differences in prevalence
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