Stimulating demand for AIDS prevention : lessons from the RESPECT trial

HIV-prevention strategies have yielded only limited success so far in slowing down the AIDS epidemic. This paper examines novel intervention strategies that use incentives to discourage risky sexual behaviors. Widely-adopted conditional cash transfer programs that offer payments conditioning on easily monitored behaviors, such as well-child health care visits, have shown positive impact on health outcomes. Similarly, contingency management approaches have successfully used outcome-based rewards to encourage behaviors that are not easily monitored, such as stopping drug abuse. These strategies have not been used in the sexual domain, so this paper assesses how incentives can be used to reduce risky sexual behavior. After discussing theoretical pathways, it discusses the use of sexual-behavior incentives in the Tanzanian RESPECT trial. There, participants who tested negative for sexually transmitted infections are eligible for outcome-based cash rewards. The trial was well-received in the communities, with high enrollment rates and more than 90 percent of participants viewing the incentives favorably. After one year, 57 percent of enrollees in the"low-value"reward arm stated that the cash rewards"very much"motivated sexual behavioral change, rising to 79 percent in the"high-value"reward arm. Despite its controversial nature, the authors argue for further testing of such incentive-based approaches to encouraging reductions in risky sexual behavior.Health Monitoring&Evaluation,Population Policies,Disease Control&Prevention,HIV AIDS,Adolescent Health

Tanzanian Couples' Perspectives on Gender Equity, Relationship Power, and Intimate Partner Violence: Findings from the RESPECT Study.

Intimate partner violence (IPV) is widely prevalent in Tanzania. Inequitable gender norms manifest in men's and women's attitudes about power and decision making in intimate relationships and are likely to play an important role in determining the prevalence of IPV. We used data from the RESPECT study, a randomized controlled trial that evaluated an intervention to prevent sexually transmitted infections in a cohort of young Tanzanian men and women, to examine the relationship between couples' attitudes about IPV, relationship power, and sexual decision making, concordance on these issues, and women's reports of IPV over 12 months. Women expressed less equitable attitudes than men at baseline. Over time, participants' attitudes tended to become more equitable and women's reports of IPV declined substantially. Multivariable logistic regression analyses suggested that inequitable attitudes and couple discordance were associated with higher risk of IPV. Our findings point to the need for a better understanding of the role that perceived or actual imbalances in relationship power have in heightening IPV risk. The decline in women's reports of IPV and the trend towards gender-equitable attitudes indicate that concerted efforts to reduce IPV and promote gender equity have the potential to make a positive difference in the relatively short term

Evolving Strategies, Opportunistic Implementation: HIV Risk Reduction in Tanzania in the Context of an Incentive-Based HIV Prevention Intervention.

\ud Behavior change communication (BCC) interventions, while still a necessary component of HIV prevention, have not on their own been shown to be sufficient to stem the tide of the epidemic. The shortcomings of BCC interventions are partly due to barriers arising from structural or economic constraints. Arguments are being made for combination prevention packages that include behavior change, biomedical, and structural interventions to address the complex set of risk factors that may lead to HIV infection. In 2009/2010 we conducted 216 in-depth interviews with a subset of study participants enrolled in the RESPECT study - an HIV prevention trial in Tanzania that used cash awards to incentivize safer sexual behaviors. We analyzed community diaries to understand how the study was perceived in the community. We drew on these data to enhance our understanding of how the intervention influenced strategies for risk reduction. We found that certain situations provide increased leverage for sexual negotiation, and these situations facilitated opportunistic implementation of risk reduction strategies. Opportunities enabled by the RESPECT intervention included leveraging conditional cash awards, but participants also emphasized the importance of exploiting new health status knowledge from regular STI testing. Risk reduction strategies included condom use within partnerships and/or with other partners, and an unexpected emphasis on temporary abstinence. Our results highlight the importance of increasing opportunities for implementing risk reduction strategies. We found that an incentive-based intervention could be effective in part by creating such opportunities, particularly among groups such as women with limited sexual agency. The results provide new evidence that expanding regular testing of STIs is another important mechanism for providing opportunities for negotiating behavior change, beyond the direct benefits of testing. Exploiting the latent demand for STI testing should receive renewed attention as part of innovative new combination interventions for HIV prevention.\u

Observation and theoretical description of the pure Fano-effect in the valence-band photo-emission of ferromagnets

The pure Fano-effect in angle-integrated valence-band photo-emission of ferromagnets has been observed for the first time. A contribution of the intrinsic spin polarization to the spin polarization of the photo-electrons has been avoided by an appropriate choice of the experimental parameters. The theoretical description of the resulting spectra reveals a complete analogy to the Fano-effect observed before for paramagnetic transition metals. While the theoretical photo-current and spin difference spectra are found in good quantitative agreement with experiment in the case of Fe and Co only a qualitative agreement could be achieved in the case of Ni by calculations on the basis of plain local spin density approximation (LSDA). Agreement with experimental data could be improved in this case in a very substantial way by a treatment of correlation effects on the basis of dynamical mean field theory (DMFT).Comment: 11 pages, 3 figures accepted by PR

Hybrid active focusing with adaptive dispersion for higher defect sensitivity in guided wave inspection of cylindrical structures

This is an Accepted Manuscript of an article published by Taylor & Francis in Nondestructive Testing and Evaluation on 23/11/2015, available online: https://www.tandfonline.com/doi/full/10.1080/10589759.2015.1093628.Ultrasonic guided wave inspection is widely used for scanning prismatic structures such as pipes for metal loss. Recent research has investigated focusing the sound energy into predetermined regions of a pipe in order to enhance the defect sensitivity. This paper presents an active focusing technique which is based on a combination of numerical simulation and time reversal concept. The proposed technique is empirically validated using a 3D laser vibrometry measurement of the focal spot. The defect sensitivity of the proposed technique is compared with conventional active focusing, time reversal focusing and synthetic focusing through an empirically validated finite element parametric study. Based on the results, the proposed technique achieves approximately 10 dB improvement of signal-to-coherent-noise ratio compared to the conventional active focusing and time reversal focusing. It is also demonstrated that the proposed technique to have an amplitude gain of around 5 dB over synthetic focusing for defects <0.5λs. The proposed technique is shown to have the potential to improve the reliably detectable flaw size in guided wave inspection from 9% to less than 1% cross-sectional area loss.TWI Ltd and the Center for Electronic System Research (CESR) of Brunel University

Hybrid active focusing with adaptive dispersion for higher defect sensitivity in guided wave inspection of cylindrical structures

This is an Accepted Manuscript of an article published by Taylor & Francis in Nondestructive Testing and Evaluation on 23/11/2015, available online: https://www.tandfonline.com/doi/full/10.1080/10589759.2015.1093628.Ultrasonic guided wave inspection is widely used for scanning prismatic structures such as pipes for metal loss. Recent research has investigated focusing the sound energy into predetermined regions of a pipe in order to enhance the defect sensitivity. This paper presents an active focusing technique which is based on a combination of numerical simulation and time reversal concept. The proposed technique is empirically validated using a 3D laser vibrometry measurement of the focal spot. The defect sensitivity of the proposed technique is compared with conventional active focusing, time reversal focusing and synthetic focusing through an empirically validated finite element parametric study. Based on the results, the proposed technique achieves approximately 10 dB improvement of signal-to-coherent-noise ratio compared to the conventional active focusing and time reversal focusing. It is also demonstrated that the proposed technique to have an amplitude gain of around 5 dB over synthetic focusing for defects <0.5λs. The proposed technique is shown to have the potential to improve the reliably detectable flaw size in guided wave inspection from 9% to less than 1% cross-sectional area loss.TWI Ltd and the Center for Electronic System Research (CESR) of Brunel University

Grappling with the Complexity of Behavioral Processes in Human Psychological Suffering: Some Potential Insights from Relational Frame Theory

Relational frame theory (RFT) has historically been considered the basic explanatory science behind acceptance and commitment therapy (ACT). However, some have argued that there has been an increasing separation between the two in recent years. The primary aim of the current article is to explore the extent to which RFT concepts, particularly those that have been proposed recently in the context of “up-dating” the theory, may be used to build stronger links between basic and applied behavior analyses in which there is a shared language of relatively precise technical terms. As an example of this strategy, we outline RFT process-based experimental and conceptual analyses of the impact of one of the most widely used sets of interventions employed in the ACT literature, defusion. In addition, we suggest a potential experimental methodology for analyzing the basic behavioral processes involved. Overall, the current article should be seen as part of a broader research agenda that aims to explore how RFT may be used to provide a functional-analytic abstractive treatment of the behavioral processes involved in human psychological suffering

Stopping Light on a Defect

Gap solitons are localized nonlinear coherent states which have been shown both theoretically and experimentally to propagate in periodic structures. Although theory allows for their propagation at any speed $v$, $0\le v\le c$, they have been observed in experiments at speeds of approximately 50% of $c$. It is of scientific and technological interest to trap gap solitons. We first introduce an explicit multiparameter family of periodic structures with localized defects, which support linear defect modes. These linear defect modes are shown to persist into the nonlinear regime, as {\it nonlinear defect modes}. Using mathematical analysis and numerical simulations we then investigate the capture of an incident gap soliton by these defects. The mechanism of capture of a gap soliton is resonant transfer of its energy to nonlinear defect modes. We introduce a useful bifurcation diagram from which information on the parameter regimes of gap soliton capture, reflection and transmission can be obtained by simple conservation of energy and resonant energy transfer principles.Comment: 45 pages, Submitted to Journal of the Optical Society

Immunogenity of the pneumococcal polysaccharide vaccine in COPD patients. The effect of systemic steroids

AbstractRationale: To investigate if systemic steroids influence the antibody response to the 23-valent pneumococcal polysaccaride vaccine (23-PPV) in COPD patients.Patients and methods: COPD patients on: (a)⩾10mg of prednisolone/day (SS, n=30); (b) inhalative steroids (IS, n=30); (c) controls without COPD (CG, n=29) were vaccinated with 23-PPV. The concentration (μg/ml) of capsular specific anti-pneumococcal IgG antibodies (AB) for the serotypes (PNC) 4,6B,9V,14,18C,19F,23F were measured by Elisa technique before, 3 and 12 months (m) after vaccination. Non-responders were defined when AB-concentrations did neither doubled nor reach ⩾1μg/ml.Results: N=24 (CG), n=29 (IS), n=18 (SS) patients completed the study (mean age 64yrs.). Serious adverse events were not observed. Geometric mean (GM) AB-concentration of all serotypes increased significantly (CG, IS, SS) 3 and 12m after vaccination (P<0.05). The percentage of non-responders ranged between 16% (PNC 19F, IS) and 65% (PNC 4, SS) after 3m and 21% (PNC 19F, IS) and 82% (PNC 4, CG) after 12m. Neither post-vaccine AB-concentrations (3 and 12m) nor the rate of non-responders differed significantly between patients on systemic steroids and the other groups (IS, CG).Conclusions: Systemic steroids did not influence the AB-response. In all groups mean AB-concentration increased significantly after vaccination but an important percentage of subjects of all three groups were non-responders