Resilience, Syndemic Factors, and Serosorting Behaviors among HIV-Positive and HIV-Negative Substance-Using MSM

Serosorting is commonly employed by MSM to reduce HIV risk. We hypothesize that MSM perceive serosorting to be effective, and that serosorting is predicted by resilience and inversely related to syndemic characteristics. Surveys included 504 substance-using MSM. Logistic regression models examined syndemic and resilience predictors of serosorting, separately by serostatus. For HIV-positive men, positive coping behaviors (P = .015) and coping self-efficacy (P = .014) predicted higher odds, and cognitive escape behaviors (P = .003) lower odds, of serosorting. For HIV-negative men, social engagement (P = .03) and coping self-efficacy (P = .01) predicted higher odds, and severe mental distress (P = .001), victimization history (P = .007) and cognitive escape behaviors (P = .006) lower odds, of serosorting. HIV-negative serosorters reported lower perceptions of risk for infection than non-serosorters (P \u3c .000). Although high risk HIV-negative men may perceive serosorting to be effective, their high rates of UAI and partner change render this an ineffective risk reduction approach. Relevant public health messages are urgently needed

A Randomized Trial of a Behavioral Intervention for High Risk Substance-Using MSM

Substance-using men who have sex with men (MSM) are among the groups at highest risk for HIV infection in the United States. We report the results of a randomized trial testing the efficacy of a small group sexual and substance use risk reduction intervention based on empowerment theory compared to an enhanced efficacious control condition among 515 high risk not-in-treatment MSM substance users. Effect sizes for sexual risk and substance use outcomes were moderate to large: HIV transmission risk frequency, d = 0.71 in the control versus 0.66 in the experimental group; number of anal sex partners, d = 1.04 versus 0.98; substance dependence symptoms, d = 0.49 versus 0.53; significant differences were not observed between conditions. Black MSM reduced their risks at a greater rate than White or Latino men. The findings point to a critically important research agenda to reduce HIV transmission among MSM substance users

The Next Big Match: Convergence, Competition and Sports Media Rights

Using examples from a number of different European countries, this article analyses the increasingly prominent position of traditional telecommunications companies, such as British Telecom (UK), Deutsche Telekom (Germany), France Telecom/Orange (France) and Telefonica (Spain), in the contemporary sports media rights market. The first part of the article examines the commercial strategies of telecommunications operators and highlights how their acquisition of sports rights has been driven by the need to ensure a competitive position within an increasingly converged communications market. The second part of the article then moves on to consider the regulation of the sports media rights market. Most significantly, this section emphasises the need for further regulatory intervention to ensure that increased competition for sports rights leads to improved services and lower prices for consumers, rather than merely endlessly spiralling fees for the exclusive ownership of premium rights that are then passed on to sports channel and/or broadband subscribers

100 kHz, 100 ms, 400 J burst-mode laser with dual-wavelength diode-pumped amplifiers

The burst duration of an all-diode-pumped burst-mode laser is extended to 100 ms and 100 kHz (10,000 pulses) by utilizing dual-wavelength diode pumping. Total energies of 225 J at 10 kHz and 400 J at 100 kHz are achieved during the 100 ms burst period at 1064 nm. This represents an order-of-magnitude increase in the number of pulses compared with prior work, while maintaining similar or higher pulse energies. Amplitude tailoring of each pulse is used to flatten the burst profile, reducing the standard deviation in pulse energy over the 100 ms burst from 3.7% to 2.1% with a burst-to-burst standard deviation of 0.8%

100-ps-pulse-duration, 100-J burst-mode laser for kHz–MHz flow diagnostics

A high-speed, master-oscillator power-amplifier burst-mode laser with ∼100 ps pulse duration is demonstrated with output energy up to 110 J per burst at 1064 nm and second-harmonic conversion efficiency up to 67% in a KD*P crystal. The output energy is distributed across 100 to 10,000 sequential laser pulses, with 10 kHz to 1 MHz repetition rate, respectively, over 10 ms burst duration. The performance of the 100 ps burst-mode laser is evaluated and been found to compare favorably with that of a similar design that employs a conventional ∼8 ns pulse duration. The nearly transform-limited spectral bandwidth of 0.15 cm−1 at 532 nm is ideal for a wide range of linear and nonlinear spectroscopic techniques, and the 100 picosecond pulse duration is optimal for fiber-coupled spectroscopic measurements in harsh reacting-flow environments

State space modelling and data analysis exercises in LISA Pathfinder

LISA Pathfinder is a mission planned by the European Space Agency to test the key technologies that will allow the detection of gravitational waves in space. The instrument on-board, the LISA Technology package, will undergo an exhaustive campaign of calibrations and noise characterisation campaigns in order to fully describe the noise model. Data analysis plays an important role in the mission and for that reason the data analysis team has been developing a toolbox which contains all the functionalities required during operations. In this contribution we give an overview of recent activities, focusing on the improvements in the modelling of the instrument and in the data analysis campaigns performed both with real and simulated data.Comment: Plenary talk presented at the 9th International LISA Symposium, 21-25 May 2012, Pari

Beyond the required LISA free-fall performance: new LISA pathfinder results down to 20 μHz

In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20  μHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05)  fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10  fm s^{-2}/sqrt[Hz] at 20  μHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency

A strategy to characterize the LISA-Pathfinder cold gas thruster system

The cold gas micro-propulsion system that will be used during the LISA-Pathfinder mission will be one of the most important component used to ensure the "free-fall" of the enclosed test masses. In this paper we present a possible strategy to characterize the effective direction and amplitude gain of each of the 6 thrusters of this system

Free-flight experiments in LISA Pathfinder

The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this `suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.Comment: 13 pages, 5 figures. Accepted to Journal Of Physics, Conference Series. Presented at 10th International LISA Symposium, May 2014, Gainesville, FL, US

The LISA pathfinder mission

ISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter. The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper