115 research outputs found
Risk factors for African swine fever incursion in Romanian domestic farms during 2019
African swine fever (ASF) entered Georgia in 2007 and the EU in 2014. In the EU, the virus primarily spread in wild boar (Sus scrofa) in the period from 2014–2018. However, from the summer 2018, numerous domestic pig farms in Romania were affected by ASF. In contrast to the existing knowledge on ASF transmission routes, the understanding of risk factors and the importance of different transmission routes is still limited. In the period from May to September 2019, 655 Romanian pig farms were included in a matched case-control study investigating possible risk factors for ASF incursion in commercial and backyard pig farms. The results showed that close proximity to outbreaks in domestic farms was a risk factor in commercial as well as backyard farms. Furthermore, in backyard farms, herd size, wild boar abundance around the farm, number of domestic outbreaks within 2 km around farms, short distance to wild boar cases and visits of professionals working on farms were statistically significant risk factors. Additionally, growing crops around the farm, which could potentially attract wild boar, and feeding forage from ASF affected areas to the pigs were risk factors for ASF incursion in backyard farms.We acknowledge financial support from EFSA, ANSVSA and from the Danish Veterinary and Food Administration (FVST) as part of the agreement of commissioned work between the Danish Ministry of Food, Agriculture and Fisheries and the University of Copenhagen.Peer reviewe
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at = 2.76 TeV
The yield of charged particles associated with high- trigger
particles ( GeV/) is measured with the ALICE detector in
Pb-Pb collisions at = 2.76 TeV relative to proton-proton
collisions at the same energy. The conditional per-trigger yields are extracted
from the narrow jet-like correlation peaks in azimuthal di-hadron correlations.
In the 5% most central collisions, we observe that the yield of associated
charged particles with transverse momenta GeV/ on the
away-side drops to about 60% of that observed in pp collisions, while on the
near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/350
Strange particle production in proton-proton collisions at TeV with ALICE at the LHC
The production of mesons containing strange quarks (K, ) and both
singly and doubly strange baryons (, Anti-, and
+Anti-) are measured at central rapidity in pp collisions at
= 0.9 TeV with the ALICE experiment at the LHC. The results are
obtained from the analysis of about 250 k minimum bias events recorded in 2009.
Measurements of yields (dN/dy) and transverse momentum spectra at central
rapidities for inelastic pp collisions are presented. For mesons, we report
yields () of 0.184 0.002 stat. 0.006 syst. for K and
0.021 0.004 stat. 0.003 syst. for . For baryons, we find
= 0.048 0.001 stat. 0.004 syst. for , 0.047
0.002 stat. 0.005 syst. for Anti- and 0.0101 0.0020 stat.
0.0009 syst. for +Anti-. The results are also compared with
predictions for identified particle spectra from QCD-inspired models and
provide a baseline for comparisons with both future pp measurements at higher
energies and heavy-ion collisions.Comment: 33 pages, 21 captioned figures, 10 tables, authors from page 28,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/387
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Research gap analysis on African swine fever
The most significant knowledge gaps in the prevention and control of African swine fever (ASF) were
identified by the EU Veterinary services and other stakeholders involved in pig production and wild boar
management through an online survey. The respondents were asked to identify the major research
needs in order to improve short-term ASF risk management. Four major gaps were identified: ‘wild boar’,
‘African swine fever virus (ASFV) survival and transmission’, ‘biosecurity’ and ‘surveillance’. In particular,
the respondents stressed the need for better knowledge on wild boar management and surveillance, and
improved knowledge on the possible mechanism for spread and persistence of ASF in wild boar
populations. They indicated the need for research on ASFV survival and transmission from the
environment, different products such as feed and feed materials, and potential arthropod vector
transmission. In addition, several research topics on biosecurity were identified as significant knowledge
gaps and the need to identify risk factors for ASFV entry into domestic pig holdings, to develop protocols
to implement specific and appropriate biosecurity measures, and to improve the knowledge about the
domestic pig–wild boar interface. Potential sources of ASFV introduction into unaffected countries need
to be better understood by an in-depth analysis of the possible pathways of introduction of ASFV with the
focus on food, feed, transport of live wild boars and human movements. Finally, research on
communication methods to increase awareness among all players involved in the epidemiology of ASF
(including truck drivers, hunters and tourists) and to increase compliance with existing control measures
was also a topic mentioned by all stakeholders
Transverse momentum spectra of charged particles in proton-proton collisions at GeV with ALICE at the LHC
The inclusive charged particle transverse momentum distribution is measured
in proton-proton collisions at GeV at the LHC using the ALICE
detector. The measurement is performed in the central pseudorapidity region
over the transverse momentum range GeV/.
The correlation between transverse momentum and particle multiplicity is also
studied. Results are presented for inelastic (INEL) and non-single-diffractive
(NSD) events. The average transverse momentum for is (stat.) (syst.) GeV/ and
\left_{\rm NSD}=0.489\pm0.001 (stat.) (syst.)
GeV/, respectively. The data exhibit a slightly larger than measurements in wider pseudorapidity intervals. The results are
compared to simulations with the Monte Carlo event generators PYTHIA and
PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/390
Production of pions, kaons and protons in pp collisions at GeV with ALICE at the LHC
The production of , , , , p, and pbar at mid-rapidity
has been measured in proton-proton collisions at GeV with the
ALICE detector. Particle identification is performed using the specific energy
loss in the inner tracking silicon detector and the time projection chamber. In
addition, time-of-flight information is used to identify hadrons at higher
momenta. Finally, the distinctive kink topology of the weak decay of charged
kaons is used for an alternative measurement of the kaon transverse momentum
() spectra. Since these various particle identification tools give
the best separation capabilities over different momentum ranges, the results
are combined to extract spectra from = 100 MeV/ to 2.5 GeV/.
The measured spectra are further compared with QCD-inspired models which yield
a poor description. The total yields and the mean are compared with
previous measurements, and the trends as a function of collision energy are
discussed.Comment: 24 pages, 18 captioned figures, 5 tables, published version, figures
at http://aliceinfo.cern.ch/ArtSubmission/node/388
Neutral pion and meson production in proton-proton collisions at TeV and TeV
The first measurements of the invariant differential cross sections of
inclusive and meson production at mid-rapidity in proton-proton
collisions at TeV and TeV are reported. The
measurement covers the ranges GeV/ and GeV/ for
these two energies, respectively. The production of mesons was measured
at TeV in the range GeV/. Next-to-Leading Order
perturbative QCD calculations, which are consistent with the spectrum
at TeV, overestimate those of and mesons at
TeV, but agree with the measured ratio at
TeV.Comment: 17 pages, 5 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/310
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