Luminosities for vector-boson vector-boson scattering at high energy colliders

We derive exact expressions for luminosities of massive vector-boson pairs which can be used to describe the cross sections for processes in hadron collisions or e^+e^- annihilation which proceed via two-vector-boson scattering. Our approach correctly takes into account the mutual influence of the emission of one vector boson on the emission of a second one. We show that only approximately the exact luminosities can be factorized into convolutions of single-vector-boson distributions. Numerical results are given and compared to simplified approaches

Understanding Perceptions of Problematic Facebook Use: When People Experience Negative Life Impact and a Lack of Control

While many people use social network sites to connect with friends and family, some feel that their use is problematic, seriously affecting their sleep, work, or life. Pairing a survey of 20,000 Facebook users measuring perceptions of problematic use with behavioral and demographic data, we examined Facebook activities associated with problematic use as well as the kinds of people most likely to experience it. People who feel their use is problematic are more likely to be younger, male, and going through a major life event such as a breakup. They spend more time on the platform, particularly at night, and spend proportionally more time looking at profiles and less time browsing their News Feeds. They also message their friends more frequently. While they are more likely to respond to notifications, they are also more likely to deactivate their accounts, perhaps in an effort to better manage their time. Further, they are more likely to have seen content about social media or phone addiction. Notably, people reporting problematic use rate the site as more valuable to them, highlighting the complex relationship between technology use and well-being. A better understanding of problematic Facebook use can inform the design of context-appropriate and supportive tools to help people become more in control.Comment: CHI 201

Regular and problematic leisure-time Internet use in the community: results from a German population-based survey

In our study, we attempted to identify systematically the use of Internet applications in the German population in order to derive risk factors for problematic use. In a representative survey of the German population, we queried 1,401 women and 1,111 men between the ages of 14 and 94 years by specific questions and standardized questionnaires on depression, anxiety (HADS), and depersonalization (CDS-2). The majority of the German population (55%) used the Internet in their leisure time. Users were younger and had a higher socioeconomic status (education, employment, income). Leisure-time use included e-mail and information search, as well as shopping. Chatting, online communities, games and sex were domains of young, mostly male adults. Overall, 9.3% reported at least one negative consequence of Internet use, especially neglect of recreational activities and problems with family/partner, work or education, and health. Problematic use was associated with longer average daily online times, avoidance of negative emotions, preference for certain applications (gaming, gam- bling, online sex) and an increased rate of depersonalization. The extent of Internet use per se is not sufficient as an addiction criterion and other negative consequences; rather, specific adverse consequences need to be identified. If the Internet is used excessively to cope with negative affect states and alternative means of coping (e.g., social support, health-promoting behavior) are diminished, a vicious cycle may ensue with increasing stress and reliance on the reinforcing properties of certain online activities that may finally lead to addictive behaviour

Tiny Real Estate Bubbles

This case is appropriate for a course in introductory real estate, real estate analysis, or economics. It provides a basis for developing an understanding of the economics of real estate markets, price to rent ratios, and speculative bubbles. The student plays the role of an external consultant to a fictitious real estate investment firm. This firm is interested in expanding its investment portfolio in small towns with tourist based economies. Real data from the Durango real estate market is provided. There are signs that the market may currently be in or possibly nearing the end of a speculative real estate bubble. Students are asked to evaluate this market and form a conclusion regarding the markets over or under valued condition. This case provides students an opportunity to consider property values based on factors other than a discount cash flow analysis. Depending on the instructor’s guidance, students can examine the case from two processes; 1) use of only the real data provided in the case or 2) further research and gathering of additional micro and macro market data. In either case the main objective of the case is for the student to develop a formal analysis and draw a conclusion regarding the current local real estate market’s over or under valuation condition

Association of CD69 Up-Regulation on CD4+ CLA+ T cells versus patch test, strip patch test and clinical history in nickel sensitization

<p>Abstract</p> <p>Objective</p> <p>The patch test (PT) with its modification - the strip patch test (SPT) - is the standard in vivo procedure to diagnose an allergic contact dermatitis (ACD). To date, none of the in vitro tests for the diagnosis of ACD fulfils the requirements of an easy, valid and reliable test. To investigate the prediction ability of a flow cytometric assay of CD69 up-regulation on CD4+ CLA+ T cells in nickel-sensitive and non-nickel-sensitive patients.</p> <p>Methods</p> <p>In a prospective, investigator-blinded, clinical study a total of 85 nickel-sensitive (n = 44; 51.8%) and non-nickel-sensitive patients (n = 41; 48.2%) were enrolled. The association between CD69 up-regulation on CD4+ CLA+ T cells on the one hand and PT, SPT, and clinical history on the other hand was measured. Association is expressed with c statistic values (receiver operating characteristic analysis) and corresponding 95% CIs.</p> <p>Results</p> <p>The associations were c = 0.57 (95% CI: 0.42-0.72) between CD69 up-regulation and PT, c = 0.49 (95% CI: 0.36-0.62) between CD69 up-regulation and SPT, and c = 0.51 (95% CI: 0.37-0.64) between CD69 up-regulation and clinical history.</p> <p>Conclusions</p> <p>CD69 up-regulation on CD4+ CLA+ T cells in vitro could not predict neither a positive PT or SPT result nor a positive clinical history to nickel sulfate. The combination of clinical history and patch testing still remains the basis for diagnosing ACD.</p

Problematic mobile phone use and smartphone addiction across generations: the roles of psychopathological symptoms and smartphone use

Contemporary technological advances have led to a significant increase in using mobile technologies. Recent research has pointed to potential problems as a consequence of mobile overuse, including addiction, financial problems, dangerous use (i.e. whilst driving) and prohibited use (i.e. use in forbidden areas). The aim of this study is to extend previous findings regarding the predictive power of psychopathological symptoms (depression, anxiety and stress), mobile phone use (i.e. calls, SMS, time spent on the phone, as well as the engagement in specific smartphone activities) across Generations X and Y on problematic mobile phone use in a sample of 273 adults. Findings revealed prohibited use and dependence were predicted by calls/day, time on the phone and using social media. Only for dependent mobile phone use (rather than prohibited), stress appeared as significant. Using social media and anxiety significantly predicted belonging to Generation Y, with calls per day predicted belonging to Generation X. This finding suggests Generation Y are more likely to use asynchronous social media-based communication, whereas Generation X engage more in synchronous communication. The findings have implications for prevention and awareness-raising efforts of possibly problematic mobile phone use for educators, parents and individuals, particularly including dependence and prohibited use