We report results from the first search for sterile neutrinos mixing with active neutrinos through a reduction in the rate of neutral-current interactions over a baseline of 810 km between the NOvA ...detectors. Analyzing a 14-kton detector equivalent exposure of 6.05×1020 protons-on-target in the NuMI beam at Fermilab, we observe 95 neutral-current candidates at the Far Detector compared with 83.5±9.7(stat)±9.4(syst) events predicted assuming mixing only occurs between active neutrino species. No evidence for νμ→νs transitions is found. Interpreting these results within a 3+1 model, we place constraints on the mixing angles θ24<20.8° and θ34<31.2° at the 90% C.L. for 0.05 eV2≤Δm412≤0.5 eV2, the range of mass splittings that produce no significant oscillations over the Near Detector baseline.
Summary Objective We aimed to characterize severity and occurrence of knee osteoarthritis (OA), and effects of age, sex, body mass, and reproductive status on population-level normal variation in ...this condition in the baboon, a natural model of human knee OA. Methods We visually inspected articular cartilage of distal right femora of 464 baboons (309 females, 155 males) and assigned an OA severity score (comparable to a modified Outerbridge score) from 1 = unaffected to 4 = advanced OA (eburnation). Presence/absence of osteophytes was recorded. We tested for significant effects of age, sex, body mass, and, in females, reproductive status (pre-, peri-, or post-menopausal) on OA. When appropriate, analyses were repeated on an age-matched subset (153 of each sex). Results Knee OA was more frequent and severe in older animals ( P < 0.0001), but significant age variation was apparent in each severity grade. Sex differences within the younger and older age groups suggest that males develop knee OA earlier, but females progress more quickly to advanced disease. There is a strong relationship between reproductive status and OA severity grade in females ( P = 0.0005) with more severe OA in peri- and post-menopausal female baboons, as in humans. Conclusions Idiopathic knee OA is common in adult baboons. Occurrence and severity are influenced strongly by reproductive status in females, and by sex with regard to patterns of disease progression – providing an animal model to investigate sex-specific variation in OA susceptibility in which the environmental heterogeneity inherent in human populations is vastly reduced.
We present updated results from the NOvA experiment for νμ→νμ and νμ→νe oscillations from an exposure of 8.85×1020 protons on target, which represents an increase of 46% compared to our previous ...publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for νμ disappearance and νe appearance gives the best-fit point as normal mass hierarchy, Δm322=2.44×10−3 eV2/c4, sin2θ23=0.56, and δCP=1.21π. The 68.3% confidence intervals in the normal mass hierarchy are Δm322∈2.37,2.52×10−3 eV2/c4, sin2θ23∈0.43,0.51∪0.52,0.60, and δCP∈0,0.12π∪0.91π,2π. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
Using two years of data from the NOvA Near Detector at Fermilab, we report a seasonal variation of cosmic ray induced multiple-muon (Nμ≥2) event rates which has an opposite phase to the seasonal ...variation in the atmospheric temperature. The strength of the seasonal multiple-muon variation is shown to increase as a function of the muon multiplicity. However, no significant dependence of the strength of the seasonal variation of the multiple-muon variation is seen as a function of the muon zenith angle, or the spatial or angular separation between the correlated muons.
Using the NOvA neutrino detectors, a broad search has been performed for any signal coincident with 28 gravitational wave events detected by the LIGO/Virgo Collaboration between September 2015 and ...July 2019. For all of these events, NOvA is sensitive to possible arrival of neutrinos and cosmic rays of GeV and higher energies. For five (seven) events in the NOvA Far (Near) Detector, timely public alerts from the LIGO/Virgo Collaboration allowed recording of MeV-scale events. No signal candidates were found.
This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of $6.05\times10^{20}$ protons-on-target from the NuMI beam at the Fermi ...National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal mixing ($\theta_{23} = \pi/4$). Assuming the normal mass hierarchy, we find $\Delta m^2 = (2.67 \pm 0.11)\times 10^{-3}$ eV$^2$ and $\sin^2 \theta_{23}$ at the two statistically degenerate values $0.404^{+0.030}_{-0.022}$ and $0.624^{+0.022}_{-0.030}$, both at the 68% confidence level. Finally, our data disfavor the maximal mixing scenario with 2.6 $\sigma$ significance.
The cross section of neutrino-induced neutral-current coherent $\pi^0$ production on a carbon-dominated target is measured in the NOvA near detector. This measurement uses a narrow-band neutrino beam ...with the average neutrino energy of 2.7\,GeV, xwhich is of interest to the ongoing and future long-baseline neutrino oscillation experiments. The measured, flux-averaged cross section is $\sigma = 14.0\pm0.9$\,(stat.)$\pm2.1$\,(syst.)$\times 10^{-40}$ $\text{cm}^2/$nucleus, consistent with model prediction. This result is the most precise measurement of neutral-current coherent $\pi^0$ production in the few-GeV neutrino energy region.
Intracortical microstructure influences crack propagation and arrest within bone cortex. Genetic variation in intracortical remodeling may contribute to mechanical integrity and, therefore, fracture ...risk. Our aim was to determine the degree to which normal population-level variation in intracortical microstructure is due to genetic variation. We examined right femurs from 101 baboons (74 females, 27 males; aged 7–33 years) from a single, extended pedigree to determine osteon number, osteon area (On.Ar), haversian canal area, osteon population density, percent osteonal bone (%On.B), wall thickness (W.Th), and cortical porosity (Ct.Po). Through evaluation of the covariance in intracortical properties between pairs of relatives, we quantified the contribution of additive genetic effects (heritability
h
2
) to variation in these traits using a variance decomposition approach. Significant age and sex effects account for 9 % (Ct.Po) to 21 % (W.Th) of intracortical microstructural variation. After accounting for age and sex, significant genetic effects are evident for On.Ar (
h
2
= 0.79,
p
= 0.002), %On.B (
h
2
= 0.82,
p
= 0.003), and W.Th (
h
2
= 0.61,
p
= 0.013), indicating that 61–82 % of the residual variation (after accounting for age and sex effects) is due to additive genetic effects. This corresponds to 48–75 % of the total phenotypic variance. Our results demonstrate that normal, population-level variation in cortical microstructure is significantly influenced by genes. As a critical mediator of crack behavior in bone cortex, intracortical microstructural variation provides another mechanism through which genetic variation may affect fracture risk.
We present updated results from the NOvA experiment for $\nu_\mu\rightarrow\nu_\mu$ and $\nu_\mu\rightarrow\nu_e$ oscillations from an exposure of $8.85\times10^{20}$ protons on target, which ...represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for $\nu_\mu$ disappearance and $\nu_e$ appearance gives the best fit point as normal mass hierarchy, $\Delta m^2_{32} = 2.44\times 10^{-3}{{\rm eV}^2}/c^4$, $\sin^2\theta_{23} = 0.56$, and $\delta_{CP} = 1.21\pi$. The 68.3% confidence intervals in the normal mass hierarchy are $\Delta m^2_{32} \in 2.37,2.52\times 10^{-3}{{\rm eV}^2}/c^4$, $\sin^2\theta_{23} \in 0.43,0.51 \cup 0.52,0.60$, and $\delta_{CP} \in 0,0.12\pi \cup 0.91\pi,2\pi$. The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
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