Cross-Layer Peer-to-Peer Track Identification and Optimization Based on Active Networking

P2P applications appear to emerge as ultimate killer applications due to their ability to construct highly dynamic overlay topologies with rapidly-varying and unpredictable traffic dynamics, which can constitute a serious challenge even for significantly over-provisioned IP networks. As a result, ISPs are facing new, severe network management problems that are not guaranteed to be addressed by statically deployed network engineering mechanisms. As a first step to a more complete solution to these problems, this paper proposes a P2P measurement, identification and optimisation architecture, designed to cope with the dynamicity and unpredictability of existing, well-known and future, unknown P2P systems. The purpose of this architecture is to provide to the ISPs an effective and scalable approach to control and optimise the traffic produced by P2P applications in their networks. This can be achieved through a combination of different application and network-level programmable techniques, leading to a crosslayer identification and optimisation process. These techniques can be applied using Active Networking platforms, which are able to quickly and easily deploy architectural components on demand. This flexibility of the optimisation architecture is essential to address the rapid development of new P2P protocols and the variation of known protocols

Peer coaching through mHealth targeting physical activity in people with Parkinson disease: feasibility study

BACKGROUND: Long-term engagement in exercise and physical activity mitigates the progression of disability and increases quality of life in people with Parkinson disease (PD). Despite this, the vast majority of individuals with PD are sedentary. There is a critical need for a feasible, safe, acceptable, and effective method to assist those with PD to engage in active lifestyles. Peer coaching through mobile health (mHealth) may be a viable approach. OBJECTIVE: The purpose of this study was to develop a PD-specific peer coach training program and a remote peer-mentored walking program using mHealth technology with the goal of increasing physical activity in persons with PD. We set out to examine the feasibility, safety, and acceptability of the programs along with preliminary evidence of individual-level changes in walking activity, self-efficacy, and disability in the peer mentees. METHODS: A peer coach training program and a remote peer-mentored walking program using mHealth was developed and tested in 10 individuals with PD. We matched physically active persons with PD (peer coaches) with sedentary persons with PD (peer mentees), resulting in 5 dyads. Using both Web-based and in-person delivery methods, we trained the peer coaches in basic knowledge of PD, exercise, active listening, and motivational interviewing. Peer coaches and mentees wore FitBit Zip activity trackers and participated in daily walking over 8 weeks. Peer dyads interacted daily via the FitBit friends mobile app and weekly via telephone calls. Feasibility was determined by examining recruitment, participation, and retention rates. Safety was assessed by monitoring adverse events during the study period. Acceptability was assessed via satisfaction surveys. Individual-level changes in physical activity were examined relative to clinically important differences. RESULTS: Four out of the 5 peer pairs used the FitBit activity tracker and friends function without difficulty. A total of 4 of the 5 pairs completed the 8 weekly phone conversations. There were no adverse events over the course of the study. All peer coaches were "satisfied" or "very satisfied" with the training program, and all participants were "satisfied" or "very satisfied" with the peer-mentored walking program. All participants would recommend this program to others with PD. Increases in average steps per day exceeding the clinically important difference occurred in 4 out of the 5 mentees. CONCLUSIONS: Remote peer coaching using mHealth is feasible, safe, and acceptable for persons with PD. Peer coaching using mHealth technology may be a viable method to increase physical activity in individuals with PD. Larger controlled trials are necessary to examine the effectiveness of this approach.This study is supported by Boston Roybal Center for Active Lifestyle Interventions (RALI Boston), Grant #P30 AG048785, and the American Parkinson Disease Association, Massachusetts chapter. The authors would like to thank Nicole Sullivan, SOT, for her assistance with data management and data collection and Nick Wendel, DPT, for his assistance with data collection. Additionally, the authors would like to thank the participants in this study for their time, effort, and insights. (P30 AG048785 - Boston Roybal Center for Active Lifestyle Interventions (RALI Boston); American Parkinson Disease Association, Massachusetts chapter)Accepted manuscrip

Structure of Peer-to-Peer Social Networks

This paper presents a statistical analysis of the structure of Peer-to-Peer (P2P) social networks that captures social associations of distributed peers in resource sharing. Peer social networks appear to be mainly composed of pure resource providers that guarantee high resource availability and reliability of P2P systems. The major peers that both provide and request resources are only a small fraction. The connectivity between peers, including undirected, directed (out and in) and weighted connections, is scale-free and the social networks of all peers and major peers are small world networks. The analysis also confirms that peer social networks show in general disassortative correlations, except that active providers are connected between each other and by active requesters. The study presented in this paper gives a better understanding of peer relationships in resource sharing, which may help a better design of future P2P networks and open the path to the study of transport processes on top of real P2P topologies.Comment: APS Style, 8 pages, 5 figures and 4 tables. Final versio

Interpersonal perceptions of adverse peer experiences in first-grade students

Aim: The aim of this study was to identify which adverse peer experiences better predict perceived negative peer relationships among elementary school first graders according to sex. The peer experiences examined were peer rejection, peer victimization, and mutual antipathy; the interpersonal perceptions studied were perceived peer victimization, dyadic meta-perception of peer disliking, and loneliness. Methods: The participants were 809 children (Mage = 6.4 years, SD = 0.32; ngirls = 412, 50.9%) enrolled in 35 first-grade classes from 15 schools in 4 Spanish regions: Valencia, n = 276, 34.1%; Balearic Islands, n = 140, 17.3%; Andalusia, n = 199, 24.6%; Castile-Leon, n = 194, 24%. We calculated sex differences in peer experiences and interpersonal perceptions by means of one-way ANOVA for means differences and Fisher’s r-to-z transformation for correlations differences. We used a multilevel regression analysis (nesting variables: class and region) to determine whether the associations between each peer experiences and each perception were unique. Results: Each adverse peer relationship predicted each interpersonal perception differentially. Peer victimization was a good predictor of the three interpersonal perceptions, and the only predictor of perceived peer victimization. Peer rejection predicted loneliness, whereas mutual antipathies predicted dyadic meta-perception of peer disliking, although more so among girls. A significant effect at region level was found but not at class level. Conclusion: Our findings suggest that research should take into account the different levels of the social peer system when analyzing peer experiences within the classroom context. The study contributes to sensitize teachers about the greater responsiveness of 6-year-old girls to adverse peer experiences, and it could be useful for designing interventions that would help children oppose rejection and empower active bystanders to fight against peer mistreatment.Ministerio de Economía y Competitividad de España EDU2012-35930Universitat Jaume I P1-1A2012-0

Caution, Student Experience May Vary: Social Identities Impact a Student's Experience in Peer Discussions

In response to calls for implementing active learning in college-level science, technology, engineering, and mathematics courses, classrooms across the country are being transformed from instructor centered to student centered. In these active-learning classrooms, the dynamics among students becomes increasingly important for understanding student experiences. In this study, we focus on the role a student prefers to assume during peer discussions, and how this preferred role may vary given a student's social identities. In addition we explore whether three hypothesized barriers to participation may help explain participation difference in the classroom. These barriers are 1) students are excluded from the discussion by actions of their groupmates; 2) students are anxious about participating in peer discussion; and 3) students do not see value in peer discussions. Our results indicate that self-reported preferred roles in peer discussions can be predicted by student gender, race/ethnicity, and nationality. In addition, we found evidence for all three barriers, although some barriers were more salient for certain students than others. We encourage instructors to consider structuring their in-class activities in ways that promote equity, which may require more purposeful attention to alleviating the current differential student experiences with peer discussions.National Science Foundation NSF DUE 1244847Science and Mathematics Educatio

Peer Effects in Risk Taking

This paper examines the effect of peers on individual risk taking. In the absence of informational motives, we investigate why social utility concerns may drive peer effects. We test for two main channels: utility from payoff differences and from conforming to the peer. We show experimentally that social utility generates substantial peer effects in risk taking. These are mainly explained by utility from payoff differences, in line with outcomebased social preferences. Contrary to standard assumptions, we show that estimated social preference parameters change significantly when peers make active choices, compared to when lotteries are randomly assigned to them

Competent, trustworthy, and likeable? Exploring which peers influence photovoltaic adoption in Germany

Little is known about the role of active peer effects (interpersonal contact) compared to passive peer effects (noticing or seeing) regarding residential photovoltaic (PV) diffusion. Recent literature suggests that peer effects are determined by the perceived credibility of one’s active peer connections regarding PV and passive peer effects. Utilising data from a survey of German house owners who either own a PV or indicate purchase intention (N = 1,165), this paper explores the underlying mechanisms of active peer effects during different stages of PV adoption decision-making. Our findings suggest that the perceived credibility of peers on PV related issues is positively associated with the reported number of adopters in the decision-maker’s peer group (passive peer effect) and also with the progress in the PV adoption decision process. Furthermore, we find a relationship between the perceived credibility of peers regarding PV and the reported influence strength of peer interactions throughout the decision-making processes of German householders, suggesting that subjective evaluations of peers play a role in active peer effects. Finally, we observe an association between the rate of self-initiated peer interactions about PV for respondents with a higher reported number of peers that have adopted PV, suggesting that passive effects (knowing peer PV adopters) play a role in initiating active peer interactions. These results are significant for all sub-groups, regardless of the decision progress. From a policy-making perspective, “bottom-up” efforts such as peer consultation and community-led outreach should be promoted in Germany to empower potential adopters