Enabling Personalized Composition and Adaptive Provisioning of Web Services

The proliferation of interconnected computing devices is fostering the emergence of environments where Web services made available to mobile users are a commodity. Unfortunately, inherent limitations of mobile devices still hinder the seamless access to Web services, and their use in supporting complex user activities. In this paper, we describe the design and implementation of a distributed, adaptive, and context-aware framework for personalized service composition and provisioning adapted to mobile users. Users specify their preferences by annotating existing process templates, leading to personalized service-based processes. To cater for the possibility of low bandwidth communication channels and frequent disconnections, an execution model is proposed whereby the responsibility of orchestrating personalized processes is spread across the participating services and user agents. In addition, the execution model is adaptive in the sense that the runtime environment is able to detect exceptions and react to them according to a set of rules

Continuous and first-order jamming transition in crossing pedestrian traffic flows

After reviewing the main results obtained within a model for the intersection of two perpendicular flows of pedestrians, we present a new finding: the changeover of the jamming transition from continuous to first order when the size of the intersection area increases.Comment: 14 pages, 9 figure

Crossing pedestrian traffic flows,diagonal stripe pattern, and chevron effect

We study two perpendicular intersecting flows of pedestrians. The latter are represented either by moving hard core particles of two types, eastbound (\symbp) and northbound (\symbm), or by two density fields, \rhop_t(\brr) and \rhom_t(\brr). Each flow takes place on a lattice strip of width $M$ so that the intersection is an $M\times M$ square. We investigate the spontaneous formation, observed experimentally and in simulations, of a diagonal pattern of stripes in which alternatingly one of the two particle types dominates. By a linear stability analysis of the field equations we show how this pattern formation comes about. We focus on the observation, reported recently, that the striped pattern actually consists of chevrons rather than straight lines. We demonstrate that this `chevron effect' occurs both in particle simulations with various different update schemes and in field simulations. We quantify the effect in terms of the chevron angle $\Delta\theta_0$ and determine its dependency on the parameters governing the boundary conditions.Comment: 36 pages, 22 figure

The effect of very low-calorie diets on renal and hepatic outcomes : a systematic review

Peer reviewedPublisher PD

Optical versus video see-through mead-mounted displays in medical visualization

We compare two technological approaches to augmented reality for 3-D medical visualization: optical and video see-through devices. We provide a context to discuss the technology by reviewing several medical applications of augmented-reality research efforts driven by real needs in the medical field, both in the United States and in Europe. We then discuss the issues for each approach, optical versus video, from both a technology and human-factor point of view. Finally, we point to potentially promising future developments of such devices including eye tracking and multifocus planes capabilities, as well as hybrid optical/video technology

Aided by Adderall: Illicit Use of ADHD Medications by College Students

“I don’t know that many kids that have done coke, none that have tried crack, and only a few that have dropped acid. I can’t even count all of the ones who’ve taken Adderall” (Stice). This statement made in an interview by a freshman art history major at the University of Maryland, College Park, in 2007 effectively highlights a still growing problem among undergraduate students in the United States: the nonmedical use of stimulant medications prescribed to treat Attention Deficit Hyperactivity Disorder (ADHD) as “study aids.” Even as early as 2004, up to twenty percent of college students had used Adderall or Ritalin, both drugs used to treat ADHD, according to a report released by the National Center on Addiction and Substance Abuse (Stice). This phenomenon of abusing prescription stimulant medications is well-documented not only in research literature but also in numerous news articles. A 2009 NPR article documented the increasingly prevalent use of ADHD medications by college students to help them study and included commentary from Martha J. Farah, director at the Center for Cognitive Neuroscience at the University of Pennsylvania, who described the behavior as “worrisome” due to the drugs’ serious side effects and the potential for addiction (Trudeau). In 2012 The New York Times published just a small fraction of the submissions they received after inviting students to share personal accounts of taking prescription medications for academic purposes, and almost all of them were written by high school students or recent graduates (Schwartz). In 2016, CBS News published a story titled “Adderall misuse rising among young adults,” making it clear that this problem has not lessened in the decade or so that has passed since publication of the 2007 article describing the growing trend of “young people taking prescription drug abuse to college” (Kraft; Stice)

Molecular evolutionary rates are not correlated with temperature and latitude in Squamata: an exception to the metabolic theory of ecology?

The metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms. Previous studies have shown that most groups of vertebrates, such as amphibians, turtles and even endothermic mammals, have higher molecular evolutionary rates in regions where temperature is high. However, the association between molecular evolutionary rates and temperature or latitude has never been tested in Squamata. We used a large dataset including the spatial distributions and environmental variables for 1,651 species of Squamata and compared the contrast of the rates of molecular evolution with the contrast of temperature and latitude between sister species. Using major axis regressions and a new algorithm to choose independent sister species pairs, we found that temperature and absolute latitude were not associated with molecular evolutionary rates. This absence of association in such a diverse ectothermic group questions the mechanisms explaining current pattern of species diversity in Squamata and challenges the presupposed universality of the metabolic theory of ecology