Background

Although time-domain measures of heart rate variability (HRV) are used to estimate cardiac autonomic tone and disease risk in multiethnic populations, the genetic epidemiology of HRV in Hispanics/Latinos has not been characterized.

Objective

The purpose of this study was to conduct a genome-wide association study of heart rate (HR) and its variability in the Hispanic Community Health Study/Study of Latinos, Multi-Ethnic Study of Atherosclerosis, and Women's Health Initiative Hispanic SNP-Health Association Resource project (n = 13,767).

Methods

We estimated HR (bpm), standard deviation of normal-to-normal interbeat intervals (SDNN, ms), and root mean squared difference in successive, normal-to-normal interbeat intervals (RMSSD, ms) from resting, standard 12-lead ECGs. We estimated associations between each phenotype and 17 million genotyped or imputed single nucleotide polymorphisms (SNPs), accounting for relatedness and adjusting for age, sex, study site, and ancestry. Cohort-specific estimates were combined using fixed-effects, inverse-variance meta-analysis. We investigated replication for select SNPs exceeding genome-wide (P <5 × 10^-8) or suggestive (P <10^-6) significance thresholds.

Results

Two genome-wide significant SNPs replicated in a European ancestry cohort, 1 one for RMSSD (rs4963772; chromosome 12) and another for SDNN (rs12982903; chromosome 19). A suggestive SNP for HR (rs236352; chromosome 6) replicated in an African-American cohort. Functional annotation of replicated SNPs in cardiac and neuronal tissues identified potentially causal variants and mechanisms.

Conclusion

This first genome-wide association study of HRV and HR in Hispanics/Latinos underscores the potential for even modestly sized samples of non-European ancestry to inform the genetic epidemiology of complex traits.

We report a measurement of the branching fraction for ψ(3770)→γχc1 and search for the transition ψ(3770)→γχc2 based on 2.92 fb-1 of e+e- data accumulated at s=3.773 GeV with the BESIII detector at the BEPCII collider. We measure B(ψ(3770)→γχc1)=(2.48±0.15±0.23)×10-3, which is the most precise measurement to date. The upper limit on the branching fraction of ψ(3770)→γχc2 at a 90% confidence level is B(ψ(3770)→γχc2)<0.64×10-3. The corresponding partial widths are Γ(ψ(3770)→γχc1)=(67.5±4.1±6.7) keV and Γ(ψ(3770)→γχc2)<17.4 keV.

The process e+e−→ pp̄π0has been studied by analyzing data collected at (formula presented) GeV, at (formula presented) GeV, and during a ψ(3770) line shape scan with the BESIII detector at the BEPCII collider. The Born cross section of p̄pπ0in the vicinity of the ψ(3770) is measured, and the Born cross section of ψ(3770) → p̄pπ0is extracted considering interference between resonant and continuum production amplitudes. Two solutions with the same probability and a significance of 1.5 σ are found. The solutions for the Born cross section of ψ(3770) → p̄pπ0are 33.8 ± 1.8 ± 2.1 pb and (formula presented) pb (< 0.22 pb at a 90% confidence level). Using the estimated cross section and a constant decay amplitude approximation, the cross section σ(p̄p → ψ(3770)π0) is calculated for the kinematic situation of the planned P̄ANDA experiment. The maximum cross section corresponding to the two solutions is expected to be less than 0.79 nb at 90% confidence level and 122 ± 10 nb at a center-of-mass energy of 5.26 GeV.

From December 2011 to May 2014, about 5 fb-1 of data were taken with the BESIII detector at center-of-mass energies between 3.810 GeV and 4.600 GeV to study the charmonium-like states and higher excited charmonium states. The time-integrated luminosity of the collected data sample is measured to a precision of 1% by analyzing events produced by the large-angle Bhabha scattering process.

We study the decays of the charmonium resonances J/ψ and ψ(3686) to the final states Ξ-Ξ+, Σ(1385) Σ(1385)± based on a single baryon tag method using data samples of (223.7±1.4)×106 J/ψ and (106.4±0.9)×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider. The decay ψ(3686)→Σ(1385) Σ(1385)± is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with, and much more precise than, the previously published results. Additionally, the ratios B(ψ(3686)→Ξ-Ξ+)B(J/ψ→Ξ-Ξ+), B(ψ(3686)→Σ(1385)-Σ(1385)+)B(J/ψ→Σ(1385)-Σ(1385)+) and B(ψ(3686)→Σ(1385)+Σ(1385)-)B(J/ψ→Σ(1385)+Σ(1385)-) are determined.

We study D0D̅0 pairs produced in e+e− collisions at √ s = 3.773 GeVusing a data sample of 2.92 fb−1 collected with the BESIII detector. We measuredthe asymmetry ACPKπ of the branching fractions of D → K−π+ in CP-odd and CP-even eigenstates to be (12.7 ± 1.3 ± 0.7) × 10−2. ACPKπ can be used to extract the strong phase difference δKπ between the doubly Cabibbo-suppressed process D̅0 → K−π+ and the Cabibbo-favored process D0 → K−π+. Using world-average values of external parameters, we obtain cos δKπ = 1.02 ±0.11 ±0.06 ±0.01. Here, the first and second uncertainties are statistical and systematic, respectively, while the third uncertainty arises from the external parameters. This is the most precise measurement of δKπ to date.

Based on (106.41±0.86)×106 ψ(3686) events collected with the BESIII detector at the BEPCII collider, the branching fractions of ψ(3686)→π+π-J/ψ, J/ψ→e+e-, and J/ψ→μ+μ- are measured. We obtain B[ψ(3686)→π+π-J/ψ]=(34.98±0.02±0.45)%, B[J/ψ→e+e-]=(5.983±0.007±0.037)%, and B[J/ψ→μ+μ-]=(5.973±0.007±0.038)%. The measurement of B[ψ(3686)→π+π-J/ψ] confirms the CLEO-c measurement, and is apparently larger than the others. The measured J/ψ leptonic decay branching fractions agree with previous experiments within one standard deviation. These results lead to B[J/ψ→l+l-]=(5.978±0.005±0.040)% by averaging over the e+e- and μ+μ- channels and a ratio of B[J/ψ→e+e-]/B[J/ψ→μ+μ-]=1.0017±0.0017±0.0033, which tests e-μ universality at the four tenths of a percent level. All the measurements presented in this paper are the most precise in the world to date.

Using a sample of 1.3 × 10(9)  J/ψ events collected with the BESIII detector, we report the first observation of η(')→π(+)π(-)π(+)π(-) and η(')→π(+)π(-)π(0)π(0). The measured branching fractions are B(η(')→π(+)π(-)π(+)π(-)) = [8.53 ± 0.69(stat.) ± 0.64(syst.)]×10(-5) and B(η(')→π(+)π(-)π(0) π(0)) = [1.82 ± 0.35(stat.) ± 0.18(syst.)] × 10(-4), which are consistent with theoretical predictions based on a combination of chiral perturbation theory and vector-meson dominance.

Using 2.92 fb-1 of electron-positron annihilation data collected at √s = 3.773 GeV with the BESIII detector, we report the results of a search for the flavor-changing neutral current process D0 →γγ using a double-tag technique. We find no signal and set an upper limit at 90% confidence level for the branching fraction of B(D0 →γγ)< 3.8 × 10-6. We also investigate D0-meson decay into two neutral pions, obtaining a branching fraction of B(D0 →π0π0)= (8.24 ± 0.21(stat) ± 0.30(syst)) × 10-4, the most precise measurement to date and consistent with the current world average.

We study the process e+ e- →(D* D*)± π∓ at a center-of-mass energy of 4.26 GeV using a 827  pb(-1) data sample obtained with the BESIII detector at the Beijing Electron Positron Collider. Based on a partial reconstruction technique, the Born cross section is measured to be (137±9±15)  pb. We observe a structure near the (D* D*)± threshold in the π∓ recoil mass spectrum, which we denote as the Zc±(4025). The measured mass and width of the structure are (4026.3±2.6±3.7)  MeV/c2 and (24.8±5.6±7.7)  MeV, respectively. Its production ratio σ(e+ e- → Zc±(4025)π∓ → (D* D*)± π∓)/σ(e+ e- → (D* D*)± π∓) is determined to be 0.65±0.09±0.06. The first uncertainties are statistical and the second are systematic.