99 research outputs found
Cosmological distance indicators
We review three distance measurement techniques beyond the local universe:
(1) gravitational lens time delays, (2) baryon acoustic oscillation (BAO), and
(3) HI intensity mapping. We describe the principles and theory behind each
method, the ingredients needed for measuring such distances, the current
observational results, and future prospects. Time delays from strongly lensed
quasars currently provide constraints on with < 4% uncertainty, and with
1% within reach from ongoing surveys and efforts. Recent exciting discoveries
of strongly lensed supernovae hold great promise for time-delay cosmography.
BAO features have been detected in redshift surveys up to z <~ 0.8 with
galaxies and z ~ 2 with Ly- forest, providing precise distance
measurements and with < 2% uncertainty in flat CDM. Future BAO
surveys will probe the distance scale with percent-level precision. HI
intensity mapping has great potential to map BAO distances at z ~ 0.8 and
beyond with precisions of a few percent. The next years ahead will be exciting
as various cosmological probes reach 1% uncertainty in determining , to
assess the current tension in measurements that could indicate new
physics.Comment: Review article accepted for publication in Space Science Reviews
(Springer), 45 pages, 10 figures. Chapter of a special collection resulting
from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in
the Space Ag
Early Measles Vaccination During an Outbreak in the Netherlands: Short-Term and Long-Term Decreases in Antibody Respo
Background. The majority of infants will not be protected by maternal antibodies until their first measles vaccination, between
12 and 15 months of age. This provides incentive to reduce the age at measles vaccination, but immunological consequences are insufficiently understood, and long-term effects are largely unknown.
Methods. A total of 79 infants who received early measles vaccination between 6 and 12 months age and a second dose at
14 months of age were compared to 44 children in a control group who received 1 dose at 14 months of age. Measles virus–specific
neutralizing antibody concentrations and avidity were determined up to 4 years of age.
Results. Infants who first received measles vaccination before 12 months of age had a long-term decrease in the concentration
and avidity of measles virus–specific neutralizing antibodies, compared with infants in the control group. For 11.1% of children with
a first dose before 9 months of age, antibody levels at 4 years of age had dropped below the cutoff for clinical protection.
Conclusions. Early measles vaccination provides immediate protection in the majority of infants but yields a long-term decrease
in neutralizing antibody responses, compared to vaccination at a later age. Additional vaccination at 14 months of age does not improve this. Over the long term, this may result in an increasing number of children susceptible to measles
Variegated squirrel bornavirus 1 in squirrels, Germany and the Netherlands
We screened squirrels in Germany and the Netherlands for the novel zoonotic variegated squirrel bornavirus 1 (VSBV-1). The detection of VSBV-1 in 11 squirrels indicates a considerable risk for transmission to humans handling those animals. Therefore, squirrels in contact with humans should routinely be tested for VSBV-1
Proficiency Testing of Virus Diagnostics Based on Bioinformatics Analysis of Simulated In Silico High-Throughput Sequencing Data Sets
Quality management and independent assessment of high-throughput
sequencing-based virus diagnostics have not yet been established as a mandatory
approach for ensuring comparable results. The sensitivity and specificity of viral
high-throughput sequence data analysis are highly affected by bioinformatics processing using publicly available and custom tools and databases and thus differ
widely between individuals and institutions. Here we present the results of the
COMPARE [Collaborative Management Platform for Detection and Analyses of (Re-)
emerging and Foodborne Outbreaks in Europe] in silico virus proficiency test. An artificial, simulated in silico data set of Illumina HiSeq sequences was provided to 13
different European institutes for bioinformatics analysis to identify viral pathogens in
high-throughput sequence data. Comparison of the participants’ analyses shows that
the use of different tools, programs, and databases for bioinformatics analyses can
impact the correct identification of viral sequences from a simple data set. The identification of slightly mutated and highly divergent virus genomes has been shown to
be most challenging. Furthermore, the interpretation of the results, together with a
fictitious case report, by the participants showed that in addition to the bioinformatics analysis, the virological evaluation of the results can be important in clinical settings. External quality assessment and proficiency testing should become an important part of validating high-throughput sequencing-based virus diagnostics and
could improve the harmonization, comparability, and reproducibility of results. There
is a need for the establishment of international proficiency testing, like that established for conventional laboratory tests such as PCR, for bioinformatics pipelines and
the interpretation of such results
The European Virus Archive goes global: A growing resource for research
The European Virus Archive (EVA) was created in 2008 with funding from the FP7-EU Infrastructure Programme, in response to the need for a coordinated and readily accessible collection of viruses that could be made available to academia, public health organisations and industry. Within three years, it developed from a consortium of nine European laboratories to encompass associated partners in Africa, Russia, China, Turkey, Germany and Italy. In 2014, the H2020 Research and Innovation Framework Programme (INFRAS projects) provided support for the transformation of the EVA from a European to a global organization (EVAg). The EVAg now operates as a non-profit consortium, with 26 partners and 20 associated partners from 21 EU and non-EU countries. In this paper, we outline the structure, management and goals of the EVAg, to bring to the attention of researchers the wealth of products it can provide and to illustrate how end-users can gain access to these resources. Organisations or individuals who would like to be considered as contributors are invited to contact the EVAg coordinator, Jean-Louis Romette, at [email protected]
Defining the risk of SARS-CoV-2 variants on immune protection
The global emergence of many severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants jeopardizes the protective antiviral immunity induced after infection or vaccination. To address the public health threat caused by the increasing SARS-CoV-2 genomic diversity, the National Institute of Allergy and Infectious Diseases within the National Institutes of Health established the SARS-CoV-2 Assessment of Viral Evolution (SAVE) programme. This effort was designed to provide a real-time risk assessment of SARS-CoV-2 variants that could potentially affect the transmission, virulence, and resistance to infection- and vaccine-induced immunity. The SAVE programme is a critical data-generating component of the US Government SARS-CoV-2 Interagency Group to assess implications of SARS-CoV-2 variants on diagnostics, vaccines and therapeutics, and for communicating public health risk. Here we describe the coordinated approach used to identify and curate data about emerging variants, their impact on immunity and effects on vaccine protection using animal models. We report the development of reagents, methodologies, models and notable findings facilitated by this collaborative approach and identify future challenges. This programme is a template for the response to rapidly evolving pathogens with pandemic potential by monitoring viral evolution in the human population to identify variants that could reduce the effectiveness of countermeasures
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