Einstein relation for random walk in a one-dimensional percolation model

We consider random walks on the infinite cluster of a conditional bond percolation model on the infinite ladder graph. In a companion paper, we have shown that if the random walk is pulled to the right by a positive bias $\lambda > 0$, then its asymptotic linear speed $\overline{\mathrm{v}}$ is continuous in the variable $\lambda > 0$ and differentiable for all sufficiently small $\lambda > 0$. In the paper at hand, we complement this result by proving that $\overline{\mathrm{v}}$ is differentiable at $\lambda = 0$. Further, we show the Einstein relation for the model, i.e., that the derivative of the speed at $\lambda = 0$ equals the diffusivity of the unbiased walk

Nigeria’s Police Work between International Reform Ideas and National Security Arrangements

Dieses Working Paper präsentiert Ergebnisse einer ethnografischen Studie (2013–2016), welche die Reform der nigerianischen Polizei untersucht hat. Ziel der von internationalen Gebern begleiteten Polizeireform ist eine Ausrichtung an der Menschenrechtsagenda. Ein besonderer Schwerpunkt der ethnografischen Untersuchung lag auf der näheren Betrachtung von Umsetzungen des Konzepts "Community Policing". Nigerias Sicherheitsarchitektur zeichnet sich mindestens seit dem Ende der Militärherrschaft im Jahr 1999 dadurch aus, dass eine Vielzahl an formellen, informellen, privaten und halbstaatlichen Organisationen mit je eigenen Agenden und Akteuren um Zuständigkeitsbereiche und Einfluss ringen. Ähnlich vielschichtig ist das Reform-Geschehen: Ansätze, die zur Verbesserung der Polizeiarbeit zugunsten der Bürger beitragen sollen, werden von internationalen Organisationen sowie der staatlichen Polizeibehörde, von nationalen NRO und lokalen Aktivisten mit unterschiedlicher Intensität vorangetrieben. Die Effekte sind widersprüchlich. Einerseits begrüßen Polizisten und Bürger die Idee der Menschenrechte, andererseits ergeben sich praktische Konflikte beim Versuch, die intendierten Veränderungen von Routinen und Prozessen umzusetzen. Die Alltagsrealitäten in den Polizeistationen, auf den Straßen und in den Haushalten widersprechen den internationalen Ansprüchen, sodass auf lokaler Ebene pragmatische Anpassungen gefunden werden.This working paper presents the findings of a 2013-2016 ethnographic study of Nigerian Police Force reform efforts. This reform process - supported by international donors - aims to implement the universal human rights agenda and the concept of community policing. Since the end of military rule in 1999, the country’s already-diverse security architecture has diversified further. A mix of formal, informal, private, and parastatal organizations and actors with often divergent agendas vie for influence and formal responsibility. These dynamics have also played out regarding police reform: Human rights-based notions of improving policing methods for the good of citizens are driven by international Organizations and the Nigerian Police Force, as well as national NGOs and local activists with varying intensity. However, the reform process has had contradictory effects. While police officers and citizens nominally welcome the notion of human rights-based policing, effecting the intended change in policing procedures and routines often leads to practical challenges. Everyday realities in police stations, precincts, on the streets, and in households are often at odds with international expectations and demands. Ultimately, police officers therefore frequently strike pragmatic compromises between the two

Determinants of Physical Activity and Screen Time Trajectories in 7th to 9th Grade Adolescents-A Longitudinal Study

Physical activity (PA) in youth tends to decline with increasing age, while sedentary behaviour including screen time (ST) increases. There are adolescents, however, whose PA and ST do not follow this pattern. The aim of this study is (i) to examine trajectories in PA and ST from grade 7-9 among students in Berlin, and (ii) to investigate the relationship of these trajectories with individual factors and school type. For the present analyses, changes in students' PA and ST across three time points from 7th to 9th grade were assessed via self-report questionnaires. Positive and negative trajectories were defined for both PA (positive: increasing or consistently high, negative: decreasing or consistently low) and ST (vice versa). Multivariable logistic regression analyses were performed to identify possible predictors of PA and ST trajectories. In total, 2122 students were included (50.2% girls, mean age 12.5 (standard deviation 0.7) years). Compared to grade 7, less students of grade 9 fulfilled PA and ST recommendations (PA: 9.4% vs. 13.2%; ST: 19.4% vs. 25.0%). The positive PA trajectory included 44% of all students (63% boys), while the positive ST trajectory included 21% of all students (30% boys). Being a boy was significantly associated with a positive PA trajectory, while being a girl, having a high socioeconomic status, and attending a high school, were significantly associated with a positive ST trajectory. Different PA and ST trajectories among adolescents should be taken into account when implementing prevention programs for this target group

Speed of sound in disordered Bose-Einstein condensates

Disorder modifies the sound-wave excitation spectrum of Bose-Einstein condensates. We consider the classical hydrodynamic limit, where the disorder correlation length is much longer than the condensate healing length. By perturbation theory, we compute the phonon lifetime and correction to the speed of sound. This correction is found to be negative in all dimensions, with universal asymptotics for smooth correlations. Considering in detail optical speckle potentials, we find a quite rich intermediate structure. This has consequences for the average density of states, particularly in one dimension, where we find a "boson dip" next to a sharp "boson peak" as function of frequency. In one dimension, our prediction is verified in detail by a numerical integration of the Gross-Pitaevskii equation.Comment: final, extended version with 2 new figure

Evidence for the late MMN as a neurophysiological endophenotype for dyslexia.

Dyslexia affects 5-10% of school-aged children and is therefore one of the most common learning disorders. Research on auditory event related potentials (AERP), particularly the mismatch negativity (MMN) component, has revealed anomalies in individuals with dyslexia to speech stimuli. Furthermore, candidate genes for this disorder were found through molecular genetic studies. A current challenge for dyslexia research is to understand the interaction between molecular genetics and brain function, and to promote the identification of relevant endophenotypes for dyslexia. The present study examines MMN, a neurophysiological correlate of speech perception, and its potential as an endophenotype for dyslexia in three groups of children. The first group of children was clinically diagnosed with dyslexia, whereas the second group of children was comprised of their siblings who had average reading and spelling skills and were therefore "unaffected" despite having a genetic risk for dyslexia. The third group consisted of control children who were not related to the other groups and were also unaffected. In total, 225 children were included in the study. All children showed clear MMN activity to/da/-/ba/contrasts that could be separated into three distinct MMN components. Whilst the first two MMN components did not differentiate the groups, the late MMN component (300-700 ms) revealed significant group differences. The mean area of the late MMN was attenuated in both the dyslexic children and their unaffected siblings in comparison to the control children. This finding is indicative of analogous alterations of neurophysiological processes in children with dyslexia and those with a genetic risk for dyslexia, without a manifestation of the disorder. The present results therefore further suggest that the late MMN might be a potential endophenotype for dyslexia

Clinical pharmacy services are reimbursed in Germany: challenges of real world implementation remain

Over the last two decades, community pharmacy has experienced major changes as the role of pharmacists is evolving from a product to a service and a patient focus. As part of this change, new and innovative clinical pharmacy services aimed at improving medicines use and patient outcomes have been designed, both nationally and internationally. Since June 2022, five services are reimbursed by all statutory health insurance funds and private insurance companies in Germany: medication review for patients with polymedication; blood pressure control in hypertension; assuring proper inhalation techniques for patients receiving a new device or a device change; medication review including a follow-up for patients taking oral anticancer drugs or immunosuppressants post-transplantation. Beyond reimbursement, the upscaling and sustainable provision of these professional services are now the main challenges. Implementation research will provide important information for the further development of pharmaceutical care programs

No rebel without a cause: shifting the debate about conflict minerals in eastern DRC

Precluding conflict financing through the minerals sector has come to be seen as the panacea to ending conflicts in the eastern Democratic Republic of the congo (DRc). The US Dodd-Frank-Act (2010) and European draft legislation attempt to reduce the financing of armed groups in conflict zones by asking companies to conduct due diligence along their supply chains to avoid the purchase of "conflict minerals". This Working Paper lays open the misconceptions that have led to such a narrow regulatory approach towards the congolese conundrum and analyses the consequences of implementing this legislation without embedding it in a wider agenda for peace. The authors argue that regulation on conflict minerals can only contribute to solving conflicts in eastern DRc if it becomes part of a wider approach to peacebuilding, which takes into account the complex reality of eastern DRc's conflicts

Komplexitätswahrnehmung im nächtlichen Straßenverkehrsraum – Einflussfaktoren und Analyse

Das Ziel der vorliegenden Arbeit ist es, Einflussfaktoren auf die Beanspruchung des Kraftfahrers im nächtlichen Straßenverkehr zu identifizieren und deren Einfluss qualitativ zu bewerten. Schwerpunkte liegen dabei auf der lichttechnischen Beurteilung dieser Faktoren und auf der Eignung biophysikalischer Signale zur Bewertung der verursachten Beanspruchung. Dazu wurden Testreihen im nächtlichen Straßenumfeld sowie im Fahrsimulator durchgeführt; die Blendung wurde isoliert im Labor untersucht. Die Feldversuche zeigten, dass das Verkehrsaufkommen auf Autobahnen den größten Einfluss auf die gefühlte Beanspruchung hat, auch die Anzahl der Fahrstreifen zeigte eine Auswirkung. Auf Landstraßen hingegen ist der Gegenverkehr der stärkste Einfluss. Sowohl Komplexitätsbewertung als auch gefahrene Geschwindigkeit zeigen signifikante Zusammenhänge zu diesem Faktor. Innerorts ist die Anzahl der Fahrstreifen ein wichtiger Faktor, wobei die Ergebnisse in diesem Fall auf vielfältige Wechselwirkungen von Einflussgrößen schließen lassen. Insgesamt wirkt die Autobahn am wenigsten anregend hinsichtlich der biophysikalischen Signale, auf Landstraßen zeigt sich eine erhöhte Reaktion der Biosignale, in der Stadt ist sie am stärksten ausgeprägt. Die Fahrsimulatorstudie zeigte, dass sich Straßenbeleuchtung positiv auf die empfundene Beanspruchung und abregend auf die Biosignale auswirkt, während Blendung durch Gegenverkehr das Gegenteil bewirkt. Eine helle Innenraumbeleuchtung wird ebenfalls als Beanspruchung empfunden, jedoch weniger stark als die Blendung. Hinsichtlich der biophysikalischen Messwerte zeigten sich bei der mittleren Herzrate und der Skin Conductance Response gute Übereinstimmungen zu der Komplexitätsbewertung. Für die Verwendung dieser Signale ist allerdings die Kontrolle der Einflussfaktoren ein wichtiger Aspekt. Eine Online-Befragung zeigte, dass sich zusätzlich zu Gegenverkehr und Verkehrsaufkommen auch Wettereinflüsse sowie die Erwartung von Wildwechsel auf die Beanspruchung beim nächtlichen Fahren auswirken. Bei Lichtquellen sind vor allem dynamische Eigenschaften wie Blinken oder Bewegung für eine Erhöhung der Beanspruchung und auch für Ablenkung von der Fahraufgabe verantwortlich. Basierend auf den Ergebnissen wurde ein qualitatives Komplexitätsmodell für das nächtliche Straßenumfeld entworfen