Prevalence of Human Papillomavirus in Adolescent Girls Before Reported Sexual Debut

Background. Human papillomavirus (HPV) vaccines are recommended for girls prior to sexual debut because they are most effective if administered before girls acquire HPV. Little research has been done on HPV prevalence in girls who report not having passed sexual debut in high HPV-prevalence countries. Methods. Using attendance registers of randomly selected primary schools in the Mwanza region of Tanzania, we enrolled girls aged 15–16 years who reported not having passed sexual debut. A face-to-face interview on sexual behavior and intravaginal practices, and a nurse-assisted self-administered vaginal swab were performed. Swabs were tested for 13 high-risk and 24 low-risk HPV genotypes. Results. HPV was detected in 40/474 (8.4%; 95% confidence interval [CI], 5.9–11.0) girls. Ten different high-risk and 21 different low-risk genotypes were detected. High-risk genotypes were detected in 5.3% (95% CI, 3.5–7.8). In multivariable analysis, only intravaginal cleansing (practiced by 20.9%) was associated with HPV detection (adjusted odds ratio = 2.19, 95% CI, 1.09–4.39). Conclusion. This cohort of adolescent Tanzanian girls had a high HPV prevalence prior to self-reported sexual debut, and this was associated with intravaginal cleansing. This most likely reflects underreporting of sexual activity, and it is possible that intravaginal cleansing is a marker for unreported sexual debut or nonpenetrative sexual behaviors

Th17 Cytokines and the Gut Mucosal Barrier

Local immune responses serve to contain infections by pathogens to the gut while preventing pathogen dissemination to systemic sites. Several subsets of T cells in the gut (T-helper 17 cells, γδ T cells, natural killer (NK), and NK-T cells) contribute to the mucosal response to pathogens by secreting a subset of cytokines including interleukin (IL)-17A, IL-17F, IL-22, and IL-26. These cytokines induce the secretion of chemokines and antimicrobial proteins, thereby orchestrating the mucosal barrier against gastrointestinal pathogens. While the mucosal barrier prevents bacterial dissemination from the gut, it also promotes colonization by pathogens that are resistant to some of the inducible antimicrobial responses. In this review, we describe the contribution of Th17 cytokines to the gut mucosal barrier during bacterial infections

Modification of χc1(3872) and ψ(2S) production in pPb collisions at √sNN = 8.16 TeV

The LHCb Collaboration measures production of the exotic hadron χc1(3872) in proton-nucleus collisions for the first time. Comparison with the charmonium state ψ(2S) suggests that the exotic χc1(3872) experiences different dynamics in the nuclear medium than conventional hadrons, and comparison with data from proton-proton collisions indicates that the presence of the nucleus may modify χc1(3872) production rates. This is the first measurement of the nuclear modification factor of an exotic hadron

Amplitude analysis of the B0→K*0μ+μ− decay

An amplitude analysis of the B 0 → K * 0 μ + μ − decay is presented using a dataset corresponding to an integrated luminosity of 4.7     fb − 1 of p p collision data collected with the LHCb experiment. For the first time, the coefficients associated to short-distance physics effects, sensitive to processes beyond the standard model, are extracted directly from the data through a q 2 -unbinned amplitude analysis, where q 2 is the μ + μ − invariant mass squared. Long-distance contributions, which originate from nonfactorizable QCD processes, are systematically investigated, and the most accurate assessment to date of their impact on the physical observables is obtained. The pattern of measured corrections to the short-distance couplings is found to be consistent with previous analyses of b - to s -quark transitions, with the largest discrepancy from the standard model predictions found to be at the level of 1.8 standard deviations. The global significance of the observed differences in the decay is 1.4 standard deviations

Enhanced production of Λb0 baryons in high-multiplicity pp collisions at √s = 13 TeV

The production rate of Λ 0 b baryons relative to B 0 mesons in p p collisions at a center-of-mass energy √ s = 13     TeV is measured by the LHCb experiment. The ratio of Λ 0 b to B 0 production cross sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e + e − collisions, and increases by a factor of ∼ 2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λ 0 b to B 0 cross sections is higher than what is measured in e + e − collisions, but converges with the e + e − ratio as the momentum increases. These results imply that the evolution of heavy b quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with several models and implications for the mechanisms enforcing quark confinement are discussed

Fraction of χc decays in prompt J/ψ production measured in pPb collisions at √sNN = 8.16 TeV

The fraction of χ c 1 and χ c 2 decays in the prompt J / ψ yield, F χ c → J / ψ = σ χ c → J / ψ / σ J / ψ , is measured by the LHCb detector in p Pb collisions at √ s NN = 8.16     TeV . The study covers the forward ( 1.5 < y ∗ < 4.0 ) and backward ( − 5.0 < y ∗ < − 2.5 ) rapidity regions, where y ∗ is the J / ψ rapidity in the nucleon-nucleon center-of-mass system. Forward and backward rapidity samples correspond to integrated luminosities of 13.6 ± 0.3 and 20.8 ± 0.5     nb − 1 , respectively. The result is presented as a function of the J / ψ transverse momentum p T , J / ψ in the range 1 < p T , J / ψ < 20     GeV / c . The F χ c → J / ψ fraction at forward rapidity is compatible with the LHCb measurement performed in p p collisions at √ s = 7     TeV , whereas the result at backward rapidity is 2.4 σ larger than in the forward region for 1 < p T , J / ψ < 3     GeV / c . The increase of F χ c → J / ψ at low p T , J / ψ at backward rapidity is compatible with the suppression of the ψ ( 2 S ) contribution to the prompt J / ψ yield. The lack of in-medium dissociation of χ c states observed in this study sets an upper limit of 180 MeV on the free energy available in these p Pb collisions to dissociate or inhibit charmonium state formation