31 research outputs found
Homogeneous nucleation under shear in a two-dimensional Ising model: cluster growth, coalescence and breakup
We compute rates and pathways for nucleation in a sheared two dimensional
Ising model with Metropolis spin flip dynamics, using Forward Flux Sampling
(FFS). We find a peak in the nucleation rate at intermediate shear rate. We
analyse the origin of this peak using modified shear algorithms and committor
analysis. We find that the peak arises from an interplay between three
shear-mediated effects: shear-enhanced cluster growth, cluster coalescence and
cluster breakup. Our results show that complex nucleation behaviour can be
found even in a simple driven model system. This work also demonstrates the use
of FFS for simulating rare events, including nucleation, in nonequilibrium
systems.Comment: 11 pages, 13 figure
An evaluation of serological methods to diagnose tick-borne encephalitis from serum and cerebrospinal fluid
Background: Tick-borne encephalitis (TBE) is an infectious disease endemic to large parts of Europe and Asia. Diagnosing TBE often relies on the detection of TBEV-specific antibodies in serum and cerebrospinal fluid (CSF) as viral genome is mostly not detectable once neurological symptoms occur. Objectives: We evaluated the performance of TBEV IgM and IgG ELISAs in both serum and CSF of confirmed TBEV patients and discuss the role of (CSF) serology in TBEV diagnostics. Study design: For the assay evaluation we collected specimen from confirmed TBEV patients. Assay specificity was assessed using sera from patients with a related flavivirus infection or other acute infection. A selected ELISA assay was used to analyze TBEV-specific antibodies in CSF and to evaluate the use in confirming TBE diagnosis. Results: In this study the overall sensitivity of the IgM TBEV ELISAs was acceptable (94-100 %). Four out of five IgM ELISA's demonstrated an excellent overall specificity from 94-100% whereas a low overall specificity was observed for the IgG TBEV ELISAs (30-71%). Intrathecal antibody production against TBEV was demonstrated in a subset of TBE patients. Conclusions: In four out of five ELISAs, IgM testing in serum and CSF of TBE patients is specific and confirmative. The lack of IgG specificity in all ELISAs emphasizes the need of confirmatory testing by virus neutralisation, depending on the patient's background and the geographic location of exposure to TBEV. A CSF-serum IgG antibody index can support the diagnosis specifically in chronic disease or once IgM has disappeared.Peer reviewe
An evaluation of serological methods to diagnose tick-borne encephalitis from serum and cerebrospinal fluid
Background: Tick-borne encephalitis (TBE) is an infectious disease endemic to large parts of Europe and Asia. Diagnosing TBE often relies on the detection of TBEV-specific antibodies in serum and cerebrospinal fluid (CSF) as viral genome is mostly not detectable once neurological symptoms occur. Objectives: We evaluated the performance of TBEV IgM and IgG ELISAs in both serum and CSF of confirmed TBEV patients and discuss the role of (CSF) serology in TBEV diagnostics. Study design: For the assay evaluation we collected specimen from confirmed TBEV patients. Assay specificity was assessed using sera from patients with a related flavivirus infection or other acute infection. A selected ELISA assay was used to analyze TBEV-specific antibodies in CSF and to evaluate the use in confirming TBE diagnosis. Results: In this study the overall sensitivity of the IgM TBEV ELISAs was acceptable (94 -100 %). Four out of five IgM ELISA's demonstrated an excellent overall specificity from 94 -100% whereas a low overall specificity was observed for the IgG TBEV ELISAs (30-71%). Intrathecal antibody production against TBEV was demonstrated in a subset of TBE patients. Conclusions: In four out of five ELISAs, IgM testing in serum and CSF of TBE patients is specific and confirmative. The lack of IgG specificity in all ELISAs emphasizes the need of confirmatory testing by virus neutralisation, depending on the patient's background and the geographic location of exposure to TBEV. A CSF-serum IgG antibody index can support the diagnosis specifically in chronic disease or once IgM has disappeared
Re-evaluation of routine dengue virus serology in travelers in the era of Zika virus emergence
Background Diagnostic requests for both Zika virus (ZIKV) and dengue virus (DENV) infections in returning travelers have significantly increased during the recent ZIKV outbreak in the AmericĂĄs. These flaviviruses have overlapping clinical syndromes and geographical distribution, but diagnostic differentiation is important because of different clinical consequences. As flaviviruses are known to have a short viremic period, diagnostics often rely on serological methods, which are challenging due to extensive cross-reactive antibodies. Objective To re-evaluate the performance of DENV serological assays in laboratory confirmed ZIKV-infected travelers. Study design The extent of cross-reactivity of the DENV NS1 antigen, IgM and IgG ELISA was analyzed in 152 clinical blood samples collected from 69 qRT-PCR and 24 virus neutralization titer (VNT) confirmed ZIKV-infected travelers. Results The majority of travelers in the presented cohort returned to the Netherlands from Suriname and presented with symptoms of fever and rash. Twenty-three percent of the female travelers were pregnant. None of the 39 ZIKV RNA positive blood samples were cross-reactive in the DENV NS1 antigen ELISA. The rates of cross-reactivity of the DENV IgM and IgG ELISĂs were 31% and 54%, respectively, after excluding travelers with (potential) previous DENV exposure. Conclusions Althoug
An evaluation of serological methods to diagnose tick-borne encephalitis from serum and cerebrospinal fluid.
International Congress on Transposable elements (ICTE 2016) in Saint Malo: mobile elements under the sun of Brittany
Abstract The third international conference on Transposable Elements (ICTE) was held 16â19 April 2016 in Saint Malo, France. Organized by the French Transposition Community (Research group of the CNRS: âMobile genetic elements: from mechanism to populations, an integrative approachâ) and the French Society of Genetics, the conferenceâs goal was to bring together researchers who study transposition in diverse organisms, using multiple experimental approaches. The meeting gathered 180 participants from all around the world. Most of them contributed through poster presentations, invited talks and short talks selected from poster abstracts. The talks were organized into six scientific sessions: âTaming mobile DNA: self and non-self recognitionâ; âTrans-generational inheritanceâ; âMobile DNA genome structure and organization, from molecular mechanisms to applicationsâ; âRemembrance of (retro)transposon past: mobile DNA in genome evolutionâ; and finally âThe yin and the yang of mobile DNA in human healthâ
Re-evaluation of routine dengue virus serology in travelers in the era of Zika virus emergence
International Congress on Transposable Elements (ICTE) 2012 in Saint Malo and the sea of TE stories
<p>Abstract</p> <p>An international conference on Transposable Elements (TEs) was held 21â24 April 2012 in Saint Malo, France. Organized by the French Transposition Community (GDR Elements GĂ©nĂ©tiques Mobiles et GĂ©nomes, CNRS) and the French Society of Genetics (SFG), the conferenceâs goal was to bring together researchers from around the world who study transposition in diverse organisms using multiple experimental approaches. The meeting drew more than 217 attendees and most contributed through poster presentations (117), invited talks and short talks selected from poster abstracts (48 in total). The talks were organized into four scientific sessions, focused on: impact of TEs on genomes, control of transposition, evolution of TEs and mechanisms of transposition. Here, we present highlights from the talks given during the platform sessions. The conference was sponsored by Alliance pour les sciences de la vie et de la santĂ© (Aviesan), Centre national de la recherche scientifique (CNRS), Institut national de la santĂ© et de la recherche mĂ©dicale (INSERM), Institut de recherche pour le dĂ©veloppement (IRD), Institut national de la recherche agronomique (INRA), UniversitĂ© de Perpignan, UniversitĂ© de Rennes 1, RĂ©gion Bretagne and Mobile DNA.</p> <p>Chair of the organization committee</p> <p>Jean-Marc Deragon</p> <p>Organizers</p> <p>Abdelkader Ainouche, Mireille BĂ©termier, Mick Chandler, Richard Cordaux, GaĂ«l Cristofari, Jean-Marc Deragon, Pascale Lesage, Didier Mazel, Olivier Panaud, Hadi Quesneville, Chantal Vaury, Cristina Vieira and ClĂ©mentine Vitte</p