Search

Abstract In this paper, we have designed a low-overhead low-complexity carrier phase tracking scheme for OFDM-based superchannel transmission system enabled by optical frequency combs. In this scheme, taking advantage of the broadband phase coherence provided by optical frequency combs among the OFDM-bands, the carrier phase retrieved from pilot-subcarriers of the OFDM-band on the central wavelength channel is reused for the OFDM-bands on the other wavelength channels. In this case, the overall pilot-subcarrier overhead and DSP complexity is significantly reduced since the pilot-subcarriers occupy a small fraction of the overall OFDM bandwidth. The feasibility of this joint-carrier phase tracking scheme has been verified successfully via comprehensive simulation, where results show that the BER threshold for soft-decision FEC could be achieved for 50GHz-spaced 5-band 4-QAM, 8-QAM, 16-QAM and 32-QAM OFDM-based superchannel signals with zero guard-band and both laser and nonlinear phase noise effects after 7000km, 4000km, 3000km and 2000km SSMF transmission respectively. The simulation results show that there exist chromatic dispersion-induced differential phase offset among the OFDM-bands whose impact on joint-carrier phase tracking depends on the modulation format, channel count and fiber length. Finally, we demonstrate experimentally the feasibility performance of the designed master-slave carrier phase tracking technique for comb-based OFDM-based superchannels.

This article presents a critical review of the education system and curriculum reforms in basic education in Kenya from independence in 1963 to date. It presents a philosophical and pragmatic basis for content review and the curriculum reform process. Data collection involved a critical review of relevant literature; including several curriculum reform documents. Based on the literature review and documentary analysis, there is overwhelming evidence that radical changes have resulted in the Kenyan education system from several curriculum reviews and major reforms in response to the changing needs of the Kenyan society. The new curriculum currently under implementation is the Competency-Based Curriculum (CBC). Over the years, there have been minimal changes in the content, scope, and sequence of the basic education curriculum. This article presents salient changes in the Kenyan education system and presents recommendations that may have significant implications for future curriculum reforms that can potentially improve learning outcomes.

Abstract Background Zimbabwe suffers from one of the greatest burdens of HIV/AIDS in the world that has been compounded by social and economic instability in the past decade. However, from 2001 to 2009 HIV prevalence among 15-49 year olds declined from 26% to approximately 14%. Behavior change and condom use may in part explain this decline. PSI-Zimbabwe socially markets the Protector Plus (P+) branded line of condoms. When Zimbabwe converted to a dollar-based economy in 2009, the price of condoms was greatly increased and new marketing efforts were undertaken. This paper evaluates the role of condom marketing, a multi-dimensional scale of brand peceptions (brand equity), and price in condom use behavior. Methods We randomly sampled sexually active men age 15-49 from 3 groups - current P+ users, former users, and free condom users. We compared their brand equity and willingness to pay based on survey results. We estimated multivariable logistic regression models to compare the 3 groups. Results We found that the brand equity scale was positive correlated with willingness to pay and with condom use. Former users also indicated a high willingness to pay for condoms. We found differences in brand equity between the 3 groups, with current P+ users having the highest P+ brand equity. As observed in previous studies, higher brand equity was associated with more of the targeted health behavior, in this case and more consistent condom use. Conclusions Zimbabwe men have highly positive brand perceptions of P+. There is an opportunity to grow the total condom market in Zimbabwe by increasing brand equity across user groups. Some former users may resume using condoms through more effective marketing. Some free users may be willing to pay for condoms. Achieving these objectives will expand the total condom market and reduce HIV risk behaviors.

Abstract Parent-child communication about sex is an important proximal reproductive health outcome. But while campaigns to promote it such as the Parents Speak Up National Campaign (PSUNC) have been effective, little is known about how messages influence parental cognitions and behavior. This study examines which message features explain responses to sexual communication messages. We content analyzed 4 PSUNC ads to identify specific, measurable message and advertising execution features. We then develop quantitative measures of those features, including message strategies, marketing strategies, and voice and other stylistic features, and merged the resulting data into a dataset drawn from a national media tracking survey of the campaign. Finally, we conducted multivariable logistic regression models to identify relationships between message content and ad reactions/receptivity, and between ad reactions/receptivity and parents' cognitions related to sexual communication included in the campaign's conceptual model. We found that overall parents were highly receptive to the PSUNC ads. We did not find significant associations between message content and ad reactions/receptivity. However, we found that reactions/receptivity to specific PSUNC ads were associated with increased norms, self-efficacy, short- and long-term expectations about parent-child sexual communication, as theorized in the conceptual model. This study extends previous research and methods to analyze message content and reactions/receptivity. The results confirm and extend previous PSUNC campaign evaluation and provide further evidence for the conceptual model. Future research should examine additional message content features and the effects of reactions/receptivity.

Abstract Background Prior research supports the notion that parents have the ability to influence their children's decisions regarding sexual behavior. Yet parent-based approaches to curbing teen pregnancy and STDs have been relatively unexplored. The Parents Speak Up National Campaign (PSUNC) is a multimedia campaign that attempts to fill this void by targeting parents of teens to encourage parent-child communication about waiting to have sex. The campaign follows a theoretical framework that identifies cognitions that are targeted in campaign messages and theorized to influence parent-child communication. While a previous experimental study showed PSUNC messages to be effective in increasing parent-child communication, it did not address how these effects manifest through the PSUNC theoretical framework. The current study examines the PSUNC theoretical framework by 1) estimating the impact of PSUNC on specific cognitions identified in the theoretical framework and 2) examining whether those cognitions are indeed associated with parent-child communication Methods Our study consists of a randomized efficacy trial of PSUNC messages under controlled conditions. A sample of 1,969 parents was randomly assigned to treatment (PSUNC exposure) and control (no exposure) conditions. Parents were surveyed at baseline, 4 weeks, 6 months, 12 months, and 18 months post-baseline. Linear regression procedures were used in our analyses. Outcome variables included self-efficacy to communicate with child, long-term outcome expectations that communication would be successful, and norms on appropriate age for sexual initiation. We first estimated multivariable models to test whether these cognitive variables predict parent-child communication longitudinally. Longitudinal change in each cognitive variable was then estimated as a function of treatment condition, controlling for baseline individual characteristics. Results Norms related to appropriate age for sexual initiation and outcome expectations that communication would be successful were predictive of parent-child communication among both mothers and fathers. Treatment condition mothers exhibited larger changes than control mothers in both of these cognitive variables. Fathers exhibited no exposure effects. Conclusions Results suggest that within a controlled setting, the "wait until older norm" and long-term outcome expectations were appropriate cognitions to target and the PSUNC media materials were successful in impacting them, particularly among mothers. This study highlights the importance of theoretical frameworks for parent-focused campaigns that identify appropriate behavioral precursors that are both predictive of a campaign's distal behavioral outcome and sensitive to campaign messages.

Abstract: Employees can view themselves as active participants in corporate social responsibility (CSR), and often view CSR as an in-role job expectation. Using role theory, this research provides a theoretical [...]

Young adults are influenced by cigarette package marketing. Pictorial warning labels are a recommended intervention. Evidence demonstrates pictorial warnings impact negative emotion, risk perceptions, and motivation to quit smoking, but there is limited research on their effects over time. This study analyzes data from a randomized trial of young adult smokers (N = 229) exposed to a pictorial or text-only cigarette warning. We assessed changes in fear, anger, risk perceptions, and motivation to quit smoking after 4 weeks using latent change score modeling and over 3 months using latent growth modeling. Latent change results showed exposure was associated with increases in fear, anger, and motivation to quit after 4 weeks. Latent growth showed exposure was associated with increases in motivation to quit smoking over 3 months, but not other outcomes. Findings suggest pictorial warning labels produce an emotional response and increase motivation to quit among young adult smokers., Author(s): Andrea C. Johnson [sup.1] , Samuel J. Simmens [sup.2] , Monique M. Turner [sup.3] , W. Douglas Evans [sup.4] , Andrew A. Strasser [sup.1] , Darren Mays [sup.5] Author [...]

The rapid growth and diffusion of digital media technologies has changed the landscape of market segmentation in the last two decades, including its use in promoting prosocial and behavior change. New, population-specific and culturally appropriate prevention strategies can leverage the potential of digital media to influence health outcomes, especially for the greatest users of digital technology, including youth and young adults. Health behavior change campaigns are increasingly shifting resources to social media, creating opportunities for innovative interventions and new research methods. This article examines three case studies of digital segmentation: (1) tobacco control from the Truth Initiative, (2) community-based public health programs from the Centers for Disease Control and Prevention, and (3) substance use (including opioids) and other risk behavior prevention from Public Good Projects. These case studies of recent digital segmentation efforts in the not-for-profit, government, and academic sectors show that it increases reach and frequency of messages delivered to priority populations. The practice of digital segmentation is rapidly growing, shows early signs of effectiveness, and may enhance future public health campaigns. Additional research could optimize its use and effectiveness in promoting prosocial and behavior change campaign outcomes.

Research tested interventions are seldom ready for wide spread use. Successful intervention adaptation to clinical settings demands an iterative process with target audience feedback. We describe the adaptation process of implementing an NCI research tested HPV vaccine intervention, Women's Stories, to a community clinic context (Planned Parenthood). Five phases are described for the adaptation of content and the development of a health kiosk intervention delivery system: (a) informant interviews with the target audience of young adult, predominantly African-American women, (b) translating HPV vaccine decision narratives into prevention messages, (c) health kiosk interface design, (d) conducting a usability study of the health kiosk intervention product, and (e) conducting a waiting room observational study. Lessons learned and challenges in adapting prevention interventions to clinical settings are discussed.

Experiments accessing extreme conditions at x-ray free electron lasers (XFELs) involve rapidly evolving conditions of temperature. Here, we report time-resolved, direct measurements of temperature using spectral streaked optical pyrometry of x-ray and optical laser-heated states at the High Energy Density instrument of the European XFEL. This collection of typical experiments, coupled with numerical models, outlines the reliability, precision, and meaning of time dependent temperature measurements using optical emission at XFEL sources. Dynamic temperatures above 1500 K are measured continuously from spectrally- and temporally-resolved thermal emission at 450–850 nm, with time resolution down to 10–100 ns for 1–200 μ s streak camera windows, using single shot and integrated modes. Targets include zero-pressure foils free-standing in air and in vacuo, and high-pressure samples compressed in diamond anvil cell multi-layer targets. Radiation sources used are 20-fs hard x-ray laser pulses at 17.8 keV, in single pulses or 2.26 MHz pulse trains of up to 30 pulses, and 250-ns infrared laser single pulses. A range of further possibilities for optical measurements of visible light in x-ray laser experiments using streak optical spectroscopy are also explored, including for the study of x-ray induced optical fluorescence, which often appears as background in thermal radiation measurements. We establish several scenarios where combined emissions from multiple sources are observed and discuss their interpretation. Challenges posed by using x-ray lasers as non-invasive probes of the sample state are addressed. [ABSTRACT FROM AUTHOR]

The authors designed and evaluated an innovative, branded campaign called 'Adelante' to promote positive youth development (PYD) and reduce risk behaviors among Latino youth near Washington, DC. Repeated cross-sectional surveys were conducted in the intervention and a comparison community to evaluate campaign exposure and changes in PYD outcomes. The sample consisted of 1549 Latino and immigrant adolescents surveyed at three time points in intervention and comparison communities. A social marketing campaign was implemented using outdoor advertising, Web, video and social media channels to promote PYD and health outcomes over a 1-year period from 2015 to 2016. Measures included media use; self-reported exposure to campaign promotions; Adelante message receptivity; validated PYD scales; substance use, sexual risk taking, violence-related knowledge, attitudes, beliefs, intentions and risk behavior. Outcomes were regressed first on campaign exposure to examine dose--response effects of the Adelante campaign over time. Second, we compared outcomes between the Adelante and comparison communities. We observed a positive effect of self-reported exposure on multiple outcomes, including improvements in pro-violence and sexual risk outcomes and lower pro-violence attitudes and lower risky attitudes toward sex. Adelante was effective in improving youth risk outcomes and offers a promising model for future health promotion with Latino and immigrant populations.

This study examines the influential role that organizational cynicism plays in understanding the relationship between ethical leadership and deviant work behavior. Scant research has addressed leadership or personality traits in determining organizational cynicism and its relationship to important outcomes such as deviant work behavior. An interactive effect of ethical leadership and conscientiousness is examined to determine if conscientious individuals are more or less prone to become organizational cynics based on the presence or absence of ethical leadership. The results suggest that conscientious individuals are less likely to rely on ethical leadership to prevent organizational cynicism and subsequent deviant behaviors. Conversely, individuals with lower levels of conscientiousness are more sensitive to ethical leadership and are more likely to respond as cynics, and with subsequent deviant behaviors. That is, individuals with higher levels of conscientiousness do not need ethical role models to prevent cynicism and deviant behaviors nearly as much as those who have lower levels of conscientiousness. The results provide important insights into how, and when, ethical leadership affects deviant workplace behavior. Keywords: organizational cynicism, ethical leadership, workplace deviance, As the employees filed into the meeting room, they awaited the Vice President of their division to announce the reason for the meeting. 'We are here today to discuss the [...]