52 research outputs found
Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3-and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows
Background
Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed.
Results
In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity.
Conclusions
Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies.info:eu-repo/semantics/publishedVersio
Descriptive analyses of maternally-derived antibody levels against porcine circovirus 2 (PCV-2) in 3- and 21-day-old piglets from farms of four European countries using different vaccination protocols in sows
Background Up to now, information on the levels of maternally-derived antibodies (MDA) against PCV-2 in suckling piglets born to sows vaccinated with different strategies is scarce in the literature. In the present observational study, the PCV-2-specific MDA titres from piglets from 109 farms (thirty 3-day-old and thirty 21-day-old piglets per farm) across four different European countries (France n = 30, Germany n = 27, Italy n = 22 and Spain n = 30) using different sow vaccination strategies (during gestation, as a gilt, as a piglet or never) were assessed. Results In all four countries, mean log PCV-2 MDA titres were higher in 3-day-old piglets than in the 3-week-old ones, being significant in most of all the comparisons performed. Within each country, the highest PCV-2-specific MDA titres were observed in the 3-day-old piglets born to sows vaccinated during gestation. Indeed, in the four countries, more than 60% of this subpopulation (3-day-old piglets from sows vaccinated during pregnancy) had the highest log PCV-2 titres detectable with the ELISA technique used in this study. The lowest MDA titres were more variable. Whereas in France and Germany the lowest titres corresponded to 21-day-old piglets born from sows vaccinated as a piglet, in Italy, they corresponded to 21-day-old piglets derived from sows vaccinated as a gilt and in Spain to 21-day-old piglets born from non-vaccinated sows. In this study, PCV-2-specific MDA titres at 3 and 21 days of age were not affected by sow parity. Conclusions Data obtained could be considered as a European global overview of PCV-2-specific MDA titres present in the pre-vaccinated piglet populations in different European countries, with titres tending to be higher in younger piglets, but with values variable among countries and sow vaccination strategies
Final Measurement of the U235 Antineutrino Energy Spectrum with the PROSPECT-I Detector at HFIR
This Letter reports one of the most precise measurements to date of the
antineutrino spectrum from a purely U235-fueled reactor, made with the final
dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By
extracting information from previously unused detector segments, this analysis
effectively doubles the statistics of the previous PROSPECT measurement. The
reconstructed energy spectrum is unfolded into antineutrino energy and compared
with both the Huber-Mueller model and a spectrum from a commercial reactor
burning multiple fuel isotopes. A local excess over the model is observed in
the 5MeV to 7MeV energy region. Comparison of the PROSPECT results with those
from commercial reactors provides new constraints on the origin of this excess,
disfavoring at 2.2 and 3.2 standard deviations the hypotheses that
antineutrinos from U235 are solely responsible and non-contributors to the
excess observed at commercial reactors respectively.Comment: The paper has been updated with an improved parametrization of the
observed antineutrino spectrum excess and extended discussion on its
potential isotopic origi
Calibration strategy of the PROSPECT-II detector with external and intrinsic sources
This paper presents an energy calibration scheme for an upgraded reactor
antineutrino detector for the Precision Reactor Oscillation and Spectrum
Experiment (PROSPECT). The PROSPECT collaboration is preparing an upgraded
detector, PROSPECT-II (P-II), to advance capabilities for the investigation of
fundamental neutrino physics, fission processes and associated reactor neutrino
flux, and nuclear security applications. P-II will expand the statistical power
of the original PROSPECT (P-I) dataset by at least an order of magnitude. The
new design builds upon previous P-I design and focuses on improving the
detector robustness and long-term stability to enable multi-year operation at
one or more sites. The new design optimizes the fiducial volume by elimination
of dead space previously occupied by internal calibration channels, which in
turn necessitates the external deployment. In this paper, we describe a
calibration strategy for P-II. The expected performance of externally deployed
calibration sources is evaluated using P-I data and a well-benchmarked
simulation package by varying detector segmentation configurations in the
analysis. The proposed external calibration scheme delivers a compatible energy
scale model and achieves comparable performance with the inclusion of an
additional AmBe neutron source, in comparison to the previous internal
arrangement. Most importantly, the estimated uncertainty contribution from the
external energy scale calibration model meets the precision requirements of the
P-II experiment.Comment: 19 pages, 10 figure
PROSPECT-II Physics Opportunities
The Precision Reactor Oscillation and Spectrum Experiment, PROSPECT, has made
world-leading measurements of reactor antineutrinos at short baselines. In its
first phase, conducted at the High Flux Isotope Reactor (HFIR) at Oak Ridge
National Laboratory, PROSPECT produced some of the strongest limits on eV-scale
sterile neutrinos, made a precision measurement of the reactor antineutrino
spectrum from U, and demonstrated the observation of reactor
antineutrinos in an aboveground detector with good energy resolution and
well-controlled backgrounds. The PROSPECT collaboration is now preparing an
upgraded detector, PROSPECT-II, to probe yet unexplored parameter space for
sterile neutrinos and contribute to a full resolution of the Reactor
Antineutrino Anomaly, a longstanding puzzle in neutrino physics. By pressing
forward on the world's most precise measurement of the U antineutrino
spectrum and measuring the absolute flux of antineutrinos from U,
PROSPECT-II will sharpen a tool with potential value for basic neutrino
science, nuclear data validation, and nuclear security applications. Following
a two-year deployment at HFIR, an additional PROSPECT-II deployment at a low
enriched uranium reactor could make complementary measurements of the neutrino
yield from other fission isotopes. PROSPECT-II provides a unique opportunity to
continue the study of reactor antineutrinos at short baselines, taking
advantage of demonstrated elements of the original PROSPECT design and close
access to a highly enriched uranium reactor core
Note on arXiv:2005.05301, 'Preparation of the Neutrino-4 experiment on search for sterile neutrino and the obtained results of measurements'
We comment on the claimed observation [arXiv:arXiv:2005.05301] of sterileneutrino oscillations by the Neutrino-4 collaboration. Such a claim, whichrequires the existence of a new fundamental particle, demands a level of rigorcommensurate with its impact. The burden lies with the Neutrino-4 collaborationto provide the information necessary to prove the validity of their claim tothe community. In this note, we describe aspects of both the data and analysismethod that might lead to an oscillation signature arising from a nullexperiment and describe additional information needed from the Neutrino-4collaboration to support the oscillation claim. Additionally, as opposed to theassertion made by the Neutrino-4 collaboration, we also show that the method of'coherent summation' using the parameter produces similar results to themethods used by the PROSPECT and the STEREO collaborations.<br
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