Attendance of MSM at Genitourinary Medicine services in England: implications for selective HPV vaccination programme (a short communication)

Background Human papillomaviruses (HPV) immunisation programmes for female adolescents in the UK offer relatively little benefit to men who have sex with men (MSM). Targeted HPV vaccination for MSM may reduce the high incidence of HPV-related disease among MSM. We used national data from sexual health clinics to calculate the number of MSM attending these clinics throughout England from 2009 to 2014 and to identify their characteristics, to inform the implementation of a targeted HPV vaccination programme in MSM. Methods We used the Genitourinary Medicine Clinic Activity Dataset (GUMCADv2) to obtain data for men aged 15–70 years who had attended a GUM clinic in England from 2009 to 2014. We analysed both numbers of MSM attending and number of GUM attendances, age at first attendance, ethnicity and geographical area of the clinic in England. Results A total of 374 983 MSM attended sexual health services in England between 2009 and 2014. Median age of presentation was 32 years (IQR 25–41) and showed regional geographical variation. Of all men attending sexual health clinics in England, the highest proportion of those identifying as MSM was in London (21%). Excluding visits within 1 month of an initial attendance, 49% of all MSM re-attended within 12 months and 58% within 24 months. MSM aged ≥36 years reattended more frequently than younger MSM. 51% reattended at least twice within 24 months of initial visit. Conclusions The majority of MSM reattend clinic at least once within a 24-month period, potentially facilitating the delivery of a three-dose HPV vaccination programme. This would reduce the burden on sexual health clinics and cost to local authorities due to extra visits if HPV vaccination were to be delivered through these services

New Analysis of the Delta I = 1/2 Rule in Kaon Decays and the B_K Parameter

We present a new analysis of the Delta I = 1/2 rule in K --> pi pi decays and the B_K parameter. We use the 1/N_c expansion within the effective chiral lagrangian for pseudoscalar mesons and compute the hadronic matrix elements at leading and next-to-leading order in the chiral and the 1/N_c expansions. Numerically, our calculation reproduces the dominant Delta I = 1/2 K --> pi pi amplitude. Our result depends only moderately on the choice of the cutoff scale in the chiral loops. The Delta I = 3/2 amplitude emerges sufficiently suppressed but shows a significant dependence on the cutoff. The B_K parameter turns out to be smaller than the value previously obtained in the 1/N_c approach. It also shows a significant dependence on the choice of the cutoff scale. Our results indicate that corrections from higher order terms and/or higher resonances are large for the Delta I = 3/2 K --> pi pi amplitude and the (|Delta S| = 2) K^0 -- anti K^0 transition amplitude.Comment: 50 pages, LaTeX, 13 eps figure

Analyzing epsilon'/epsilon in the 1/N_c Expansion

We present a recent analysis of epsilon'/epsilon in the 1/N_c expansion. We show that the 1/N_c corrections to the matrix element of Q_6 are large and positive, indicating a Delta I=1/2 enhancement similar to the one of Q_1 and Q_2 which dominate the CP conserving amplitude. This enhances the CP ratio and can bring the standard model prediction close to the measured value for central values of the parameters.Comment: One reference corrected. 5 pages, talk presented by P.H. Soldan at the 3. International Conference on B Physics and CP Violation, Taipei, Taiwan, December 3 - 7, 1999. Slightly expanded version of the article submitted to the proceeding

Interpretation of runaway electron synchrotron and bremsstrahlung images

The crescent spot shape observed in DIII-D runaway electron synchrotron radiation images is shown to result from the high degree of anisotropy in the emitted radiation, the finite spectral range of the camera and the distribution of runaways. The finite spectral camera range is found to be particularly important, as the radiation from the high-field side can be stronger by a factor $10^6$ than the radiation from the low-field side in DIII-D. By combining a kinetic model of the runaway dynamics with a synthetic synchrotron diagnostic we see that physical processes not described by the kinetic model (such as radial transport) are likely to be limiting the energy of the runaways. We show that a population of runaways with lower dominant energies and larger pitch-angles than those predicted by the kinetic model provide a better match to the synchrotron measurements. Using a new synthetic bremsstrahlung diagnostic we also simulate the view of the Gamma Ray Imager (GRI) diagnostic used at DIII-D to resolve the spatial distribution of runaway-generated bremsstrahlung.Comment: 21 pages, 11 figure

The epidemiology of East Coast Fever in Malawi Zebu cattle and the economics of tick-borne disease control in Malawi

Morbidity, mortality and seroconversion to Theileria parva were studied in Malawi zebu cattle in six areas in the same ecological zone. A total of 3,257 animals were intensively monitored over a period of three years. Strategic tick control was carried out in four areas and no tick control was performed in a further two areas. Strenuous efforts were made to diagnose illness and deaths in the cattle.The seasonal fluctuations in numbers of ticks on the cattle were observed at fourweekly intervals for three-and-a half years. Productivity of the cattle belonging to 143 farmers in the six areas was also monitored. Seroconversion to Cowdria ruminantium was monitored for the first year of the study.Strategic dipping using nine immersions, at two-week intervals, from December to March gave almost complete control of R. appendiculatus but the numbers of B. microplus and A. variegatum were similar in dipped and undipped animals.One undipped area was in an epidemiologically unstable state with respect to East Coast fever (ECF) due to prior dipping. East Coast fever mortality and morbidity were low in the first year after the cessation of dipping but rose over the second and third year until 46% of calves died ofECF before reaching one year of age. In the other undipped area ECF mortality and morbidity were low for all three years, despite high T. parva seroconversion rates. Dipping had ceased three years before the study began and it was concluded that this area was in a stable state with respect to ECF.Strategic dipping in the other four areas caused very low ECF morbidity and mortality, as determined by comparison with the undipped control cattle. ECF mortality in strategically dipped calves was zero in most areas for most years.Adult R. appendiculatus were responsible for most ofthe T. parva transmission causing clinical disease with nymphs responsible for a significant amount of sub¬ clinical infection. The existence of enzootic stability to ECF in an undipped area without continuous adult R. appendiculatus activity was demonstrated and the significance of nymphal transmission to the maintenance of this stability is discussed.The costs and benefits of various tick-borne disease control strategies were calculated. Policies of vaccination or strategic dipping where tank construction was necessary were significantly less cost effective than policies involving stopping dipping or the continuation of strategic dipping at an existing tank. The most costeffective option would be to stop dipping and accept mortalities while endemic stability becomes established. This could however have a large social cost due to mortality in the early years

Ultracold collisions involving heteronuclear alkali metal dimers

We have carried out the first quantum dynamics calculations on ultracold atom-diatom collisions in isotopic mixtures. The systems studied are spin-polarized 7Li + 6Li7Li, 7Li + 6Li2, 6Li + 6Li7Li and 6Li + 7Li2. Reactive scattering can occur for the first two systems even when the molecules are in their ground rovibrational states, but is slower than vibrational relaxation in homonuclear systems. Implications for sympathetic cooling of heteronuclear molecules are discussed.Comment: 4 pages, 3 figure