Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Tech, Blacksburg 24061-0442, USA.
Thirteen lactating dairy cows from a herd of 650 died over a 6-week ...period. Most animals were down in milk production at 1 milking and were found dead at the next milking. Two cows had elevated heart rate and enlarged mandibular lymph nodes. Two others had azotemia, elevated heart rate, hyperglycemia, and weight loss. Necropsy of 10 cows revealed hemorrhages on the intestinal serosa and epicardium, lymphadenopathy, interstitial nephritis, small intestinal hemorrhage, and interstitial pneumonia. Histopathology showed lymphocytic to lymphogranulomatous inflammation in the heart, spleen, kidney, lymph nodes, liver, lung, pancreas, and adrenal gland. Phlebitis was present in 2 livers. The lesions resembled those of hairy vetch toxicosis, but no vetch was being fed. Similar lesions have been reported with the feeding of citrus pulp. Citrus pulp was being fed to the lactating cows and had been added to the diet 6 weeks before the first death. The syndrome resolved with elimination of citrus pulp from the diet.
The production of χ_{c1}(3872) and ψ(2S) hadrons is studied as a function of charged particle multiplicity in pp collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated ...luminosity of 2 fb^{-1}. For both states, the fraction that is produced promptly at the collision vertex is found to decrease as charged particle multiplicity increases. The ratio of χ_{c1}(3872) to ψ(2S) cross sections for promptly produced particles is also found to decrease with multiplicity, while no significant dependence on multiplicity is observed for the equivalent ratio of particles produced away from the collision vertex in b-hadron decays. This behavior is consistent with a calculation that models the χ_{c1}(3872) structure as a compact tetraquark. Comparisons with model calculations and implications for the binding energy of the χ_{c1}(3872) state are discussed.
Searches for the rare hadronic decays B0→p¯pp¯p and B0s→p¯pp¯p are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9 ...fb−1. Significances of 9.3σ and 4.0σ, including statistical and systematic uncertainties, are obtained for the B0→p¯pp¯p and B0s→p¯pp¯p signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B0→J/ψ(→p¯p)K*0(→K+π−) and B0s→J/ψ(→p¯p)ϕ(→K+K−). The branching fractions are measured to be B(B0→p¯pp¯p)=(2.2±0.4±0.1±0.1)×10−8 and B(B0s→p¯pp¯p)=(2.3±1.0±0.2±0.1)×10−8. In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.
The production rate of $B^{0}_{s}$ mesons relative to $B^0$ mesons is measured by the LHCb experiment in $pp$ collisions at a center-of-mass energy $\sqrt{s}$ = 13 TeV over the forward rapidity ...interval 2 < $y$ < 4.5 as a function of the charged particle multiplicity measured in the event. Evidence at the 3.4$σ$ level is found for an increase of the ratio of $B^{0}_{s}$ to $B^0$ cross sections with multiplicity at transverse momenta below 6 GeV /$c$, with no significant multiplicity dependence at higher transverse momentum. Comparison with data from $e^+$ $e^–$ collisions implies that the density of the hadronic medium may affect the production rates of $B$ mesons. This is qualitatively consistent with the emergence of quark coalescence as an additional hadronization mechanism in high-multiplicity collisions.
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