Increasing prevalence of male homosexual partnerships and practices in Britain 1990-2000: evidence from national probability surveys.

OBJECTIVES: To estimate the prevalence and timing of homosexual experience among British men; to explore the patterns of sexual practices and partnerships in 2000, and behavioural and attitudinal changes between 1990 and 2000 among men who have sex with men (MSM). DESIGN: Two large, stratified probability sample surveys of the general population. METHODS: Trained interviewers administered a combination of face-to-face and self-completion questionnaires to men aged 16 to 44 years resident in Britain (n = 6000 in 1990 and n = 4762 in 2000). RESULTS: In 2000, 2.8% of British men reported sex with men in the past 5 years. 46.0% of MSM reported five or more partners in the past 5 years, and 59.8% reported unprotected anal intercourse in the past year. A total of 33.0% of MSM reported one or more female partner(s) in the past year. In comparison with 1990, there was a significant increase in the proportion of MSM in the population in 2000, and among these men, in the proportion reporting receptive anal intercourse in the past year [age-adjusted odds ratio (OR), 2.08; 95% confidence interval (CI), 1.08-4.00], but no significant change in self-perceived HIV-risk (age-adjusted OR, 1.11; 95% CI, 0.49-2.51) or HIV testing in past 5 years (age-adjusted OR, 1.14; 95% CI, 0.57-2.25). CONCLUSIONS: Evidence of increasing prevalence of homosexual intercourse among the British male population coupled with increases in some HIV-risk behaviours among MSM suggests overall increasing numbers at risk in the population. Although these changes may partly reflect an increased willingness to report these behaviours, our results are consistent with increasing incidence of sexually transmitted infections and behavioural surveillance data

Ethnic variations in sexual behaviour in Great Britain and risk of sexually transmitted infections: a probability survey.

BACKGROUND: Ethnic variations in the rate of diagnosed sexually transmitted infections (STIs) have been reported in many developed countries. We used data from the second British National Survey of Sexual Attitudes and Lifestyles (Natsal 2000) to investigate the frequency of high-risk sexual behaviours and adverse sexual health outcomes in five ethnic groups in Great Britain. METHODS: We did a stratified probability sample survey of 11161 men and women aged 16-44 years, resident in Great Britain, using computer-assisted interviews. Additional sampling enabled us to do more detailed analyses for 949 black Caribbean, black African, Indian, and Pakistani respondents. We used logistic regression to assess reporting of STI diagnoses in the past 5 years, after controlling for demographic and behavioural variables. FINDINGS: We noted striking variations in number of sexual partnerships by ethnic group and between men and women. Reported numbers of sexual partnerships in a lifetime were highest in black Caribbean (median 9 [IQR 4-20]) and black African (9 [3-20]) men, and in white (5 [2-9]) and black Caribbean (4 [2-7]) women. Indian and Pakistani men and women reported fewer sexual partnerships, later first intercourse, and substantially lower prevalence of diagnosed STIs than did other groups. We recorded a significant association between ethnic origin and reported STIs in the past 5 years with increased risk in sexually active black Caribbean (OR 2.74 [95% CI 1.22-6.15]) and black African (2.95 [1.45-5.99]) men compared with white men, and black Caribbean (2.41 [1.35-4.28]) women compared with white women. Odds ratios changed little after controlling for age, number of sexual partnerships, homosexual and overseas partnerships, and condom use at last sexual intercourse. INTERPRETATION: Individual sexual behaviour is a key determinant of STI transmission risk, but alone does not explain the varying risk across ethnic groups. Our findings suggest a need for targeted and culturally competent prevention interventions

Formation of the oxygen torus in the inner magnetosphere: Van Allen Probes observations

We study the formation process of an oxygen torus during the 12–15 November 2012 magnetic storm, using the magnetic field and plasma wave data obtained by Van Allen Probes. We estimate the local plasma mass density (ρL) and the local electron number density (neL) from the resonant frequencies of standing Alfvén waves and the upper hybrid resonance band. The average ion mass (M) can be calculated by M ∼ ρL/neL under the assumption of quasi-neutrality of plasma. During the storm recovery phase, both Probe A and Probe B observe the oxygen torus at L = 3.0–4.0 and L = 3.7–4.5, respectively, on the morning side. The oxygen torus has M = 4.5–8 amu and extends around the plasmapause that is identified at L∼3.2–3.9. We find that during the initial phase, M is 4–7 amu throughout the plasma trough and remains at ∼1 amu in the plasmasphere, implying that ionospheric O+ ions are supplied into the inner magnetosphere already in the initial phase of the magnetic storm. Numerical calculation under a decrease of the convection electric field reveals that some of thermal O+ ions distributed throughout the plasma trough are trapped within the expanded plasmasphere, whereas some of them drift around the plasmapause on the dawnside. This creates the oxygen torus spreading near the plasmapause, which is consistent with the Van Allen Probes observations. We conclude that the oxygen torus identified in this study favors the formation scenario of supplying O+ in the inner magnetosphere during the initial phase and subsequent drift during the recovery phase

A Mixed-Methods Evaluation of a Community-Based Glaucoma Check Service in Hackney, London, UK.

: To evaluate the uptake, feasibility and acceptability of a general practice-based optometrist-led glaucoma check service. The service targeted people of black Caribbean and black African descent aged 40-65 years, resident in Hackney, London, United Kingdom. : The study used a mixed-method design, including analysis of service data, prospective audit of secondary care referrals patient survey, cost-consequence analysis, and interviews with staff involved in developing and implementing the service. : A total of 3040 patients were invited to undergo the free check; 595 (19.6%) booked an appointment and 461 (15.2%) attended. Overall, 31 patients (6.8%) were referred to secondary care, of whom 22 attended and were assessed for glaucoma. Four were diagnosed with glaucoma and eight with suspected glaucoma, i.e. 2.6% of patients who underwent the check. The cost per patient identified with suspected or confirmed glaucoma was £9,013. Staff who were interviewed suggested that patients who attended might be those who routinely attended optometrist appointments, however only 62.4% of survey respondents reported having had an eye examination in the previous two years, and 11.4% of women and 16.0% of men reported never having had an eye examination. : This study represents one possible configuration for a glaucoma case-finding service, and it contributes to a wider debate about whether screening, targeted or otherwise, should be offered in the UK. Our findings suggest that general practice is an acceptable setting and that such a service may reach some people not previously engaged with primary eye care services.<br/

Antenna Deployment for a Pathfinder Lunar Radio Observatory

A first step in the development of a large radio observatory on the moon for cosmological or other astrophysical and planetary goals is to deploy a few antennas as a pathfinder mission. In this presentation, we describe a mechanism being developed to deploy such antennas from a small craft, such as a Google Lunar X-prize lander. The antenna concept is to deposit antennas and leads on a polyimide film, such as Kapton, and to unroll the film on the lunar surface. The deployment technique utilized is to launch an anchor which pulls a double line from a reel at the spacecraft. Subsequently, the anchor is set by catching on the surface or collecting sufficient regolith. A motor then pulls in one end of the line, pulling the film off of its roller onto the lunar surface. Detection of a low frequency cutoff of the galactic radio background or of solar radio bursts by such a system would determine the maximum lunar ionospheric density at the time of measurement. The current design and testing, including videos of the deployment, will be presented. These activities are funded in part by the NASA Lunar Science Institute as an activity of the Lunar University Network for Astrophysical Research (LUNAR) consortium. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration

THERMAL DENATURATION OF MONOMERIC AND TRIMERIC PHYCOCYANINS STUDIED BY STATIC AND SPECTROSCOPY POLARIZED TIME-RESOLVED FLUORESCENCE

C-Phycocyanin (PC) and allophycocyanin (APC). as well as the a-subunit of PC. have been isolated from the blue-green alga (cyanobacterium). Spirulina platensis. The effects of partial thermal denaturation of PC and of its state of aggregation have been studied by ps time-resolved, polarized fluorescence spectroscopy. All measurements have been performed under low photon fluxes (< 10’ ’ photonsipulse x cm’) to minimize singlet-singlet annihilation processes. A complex decay is obtained under most conditions, which can be fitted satisfactorily with a bi-exponential (7’ = 70400 ps. T? = 1000-3000 ps) for both the isotropic and the polarized part, but with different intensities and time constants for the two decay curves. The data are interpreted in the frameworkof the model first developed by Teak and Dale (Biochern. J. 116, 161 (1970)], which divides the spectroscopically different chromophores in (predominantly) sensitizing (s) and fluorescing U, ones. If one assumes temperature dependent losses in the energy transfer from the s to the f and between f chromophores. both the biexponential nature of the isotropic fluorescence decay and the polarization data can be rationalized. In the isotropic emission (corresponding to the population of excited states) the short lifetime is related to the s-,f transfer. the longer one to the “free“ decay of the final acceptor(s) (= f). The polarized part is dominated by an extremely short decay time. which is related to s+f transfer, as well as to resonance transfer between the f-chromophores

Lessons from Love-Locks: The archaeology of a contemporary assemblage

This document is the Accepted Manuscript version. The final, definitive version of this paper has been published in Journal of Material Culture, November 2017, published by SAGE Publishing, All rights reserved.Loss of context is a challenge, if not the bane, of the ritual archaeologist’s craft. Those who research ritual frequently encounter difficulties in the interpretation of its often tantalisingly incomplete material record. Careful analysis of material remains may afford us glimpses into past ritual activity, but our often vast chronological separation from the ritual practitioners themselves prevent us from seeing the whole picture. The archaeologist engaging with structured deposits, for instance, is often forced to study ritual assemblages post-accumulation. Many nuances of its formation, therefore, may be lost in interpretation. This paper considers what insights an archaeologist could gain into the place, people, pace, and purpose of deposition by recording an accumulation of structured deposits during its formation, rather than after. To answer this, the paper will focus on a contemporary depositional practice: the love-lock. This custom involves the inscribing of names/initials onto a padlock, its attachment to a bridge or other public structure, and the deposition of the corresponding key into the water below; a ritual often enacted by a couple as a statement of their romantic commitment. Drawing on empirical data from a three-year diachronic site-specific investigation into a love-lock bridge in Manchester, UK, the author demonstrates the value of contemporary archaeology in engaging with the often enigmatic material culture of ritual accumulations.Peer reviewe