On the Security of the Automatic Dependent Surveillance-Broadcast Protocol

Automatic dependent surveillance-broadcast (ADS-B) is the communications protocol currently being rolled out as part of next generation air transportation systems. As the heart of modern air traffic control, it will play an essential role in the protection of two billion passengers per year, besides being crucial to many other interest groups in aviation. The inherent lack of security measures in the ADS-B protocol has long been a topic in both the aviation circles and in the academic community. Due to recently published proof-of-concept attacks, the topic is becoming ever more pressing, especially with the deadline for mandatory implementation in most airspaces fast approaching. This survey first summarizes the attacks and problems that have been reported in relation to ADS-B security. Thereafter, it surveys both the theoretical and practical efforts which have been previously conducted concerning these issues, including possible countermeasures. In addition, the survey seeks to go beyond the current state of the art and gives a detailed assessment of security measures which have been developed more generally for related wireless networks such as sensor networks and vehicular ad hoc networks, including a taxonomy of all considered approaches.Comment: Survey, 22 Pages, 21 Figure

Long-term care and intermediary structures for frail older people : Switzerland and Germany in comparison

This is a post-peer-review, pre-copy edited version of an article published in [International journal of care and caring]. The definitive publisher-authenticated version is available online at: https://doi.org/10.1332/239788218X15265697287824Long-term care not only includes residential care, home care and familial care, but services ‘in-between’, such as day and night care, temporary (short-term) stays in nursing homes, respite care, and local infrastructure giving informed advice and conveying informal support. In both Switzerland and Germany, the role of such intermediary structures has been debated and affected by social policy reforms. The authors analyse different functions of intermediary structures, discuss their access and use, and show that intermediary structures can have a different impact on care regimes

A sequential direct arylation/Suzuki-Miyaura cross-coupling transformation of unprotected 2 '-deoxyadenosine affords a novel class of fluorescent analogues

Novel rigid 8-biaryl-2'-deoxyadenosines with tuneable fluorescent properties can be accessed by an efficient sequential catalytic Pd-0-coupling approach

Wissen und sein Gebrauch im Spätmittelalter. Einige grundsätzliche Überlegungen am Beispiel von Beschreibungen der Iberischen Halbinsel

Das Mittelalter wird gewöhnlich als eine Epoche verstanden, in der wissenschaftliche, schriftstellerische Tätigkeit den Idealen und der Norm eines ordo folgte. Triff t dies für das 15. Jahrhundert noch zu? Die vorliegenden Untersuchungen, entstanden aus einer Abschlussarbeit an der Universität Potsdam, scheinen das Gegenteil zu belegen. In einer Analyse wissenschaftlicher Beschreibungen der Hispania konnten eine Reihe unterschiedlicher Strategien identifi ziert werden, wie Informationen aus älteren Werken inkorporiert und bearbeitet wurden. Dabei erstrecken sich die Strategien über die ganze Spannweite vom einfachen Zitaten über eine vorsichtige Neubewertung bis hin zur Generierung von neuem Wissen aufgrund älterer Texte oder sogar aufgrund von Anwendungswissen.Th e Middle Ages are generally considered as a time where literary production that can be regarded as scholarly adhered to the ideals of ordo and norm. But is this still true for the 15th century? Investigations undertaken in the context of a thesis at the University of Potsdam suggest the contrary: In scholarly descriptions of the Hispania, a number of diff erent strategies of processing information from older works could be identifi ed. Th ey range from simple citation over a careful review of established knowledge all the way to generating new information based on older texts or even applied knowledge

Adult ADHD and the Relationship Between Self-Reported Frequency of Cognitive Distortions, Anxiety, and Depression

Cognitive-behavioral therapy for adults with ADHD often includes strategies to address cognitive distortions. Although identifying cognitive distortions as part of a causal chain related to disorders such as anxiety and depression has been well studied, limited research has focused on the relationship between ADHD and cognitive distortions. The goal of this study was to determine the nature of the relationship between ADHD, cognitive distortions, anxiety, and depression within a group of adult outpatients from an ADHD treatment center (N = 30). Results indicated that the severity of ADHD symptomatology, identified through a self-report scale, was significantly related to the self-reported frequency of cognitive distortions. The direct positive relationship between ADHD severity and frequency of cognitive distortions (a) existed independently of comorbid anxiety and/or depression and (b) remained significant when the relationship was explored with a portion of the sample that completed additional ADHD self-report scales for primary inattentive symptoms (n = 27). This is one of few studies to explore the nature of the relationship between adult ADHD and cognitive distortions. Furthermore, this study provides empirical support for the inclusion of cognitive-behavioral techniques that consider cognitive distortions in this population

Radiative proton-antiproton annihilation and isospin mixing in protonium

A detailed analysis of the radiative $p\bar p$ annihilation is made in the framework of a two-step formalism, the $p\bar p$ annihilates into meson channels containing a vector meson with a subsequent conversion into a photon via the vector dominance model (VDM). Both steps are derived from the underlying quark model. First, branching ratios for radiative protonium annihilation are calculated and compared with data. Then, details of the isospin interference are studied for different models of the initial protonium state and also for different kinematical form factors. The isospin interference is shown to be uniquely connected to the $p\bar p - n\bar n$ mixing in the protonium state. Values of the interference terms directly deduced from data are consistent with theoretical expectations, indicating a dominant $p\bar p$ component for the $^1S_0$ and a sizable $n\bar n$ component for the $^3S_1$ protonium state. The analysis is extended to the $p\bar p \to \gamma \Phi$ transition, where the large observed branching ratio remains unexplained in the VDM approach.Comment: 34 pages, RevTeX, 2 figures, to appear in Phys. Rev. C; typos correcte