Statistical properties of localisation--delocalisation transition in one dimension

We study a one-dimensional model of disordered electrons (also relevant for random spin chains), which exhibits a delocalisation transition at half-filling. Exact probability distribution functions for the Wigner time and transmission coefficient are calculated. We identify and distinguish those features of probability densities that are due to rare, trapping configurations of the random potential from those which are due to the proximity to the delocalisation transition.Comment: 4 pages, RevTeX, 1 fi

Interaction of infalling solid bodies with primordial atmospheres of disk-embedded planets

Planets that form early enough to be embedded in the circumstellar gas disk accumulate thick atmospheres of nebular gas. Models of these atmospheres need to specify the surface luminosity (i.e. energy loss rate) of the planet. This luminosity is usually associated with a continuous inflow of solid bodies, where the gravitational energy released from these bodies is the source of energy. However, if these bodies release energy in the atmosphere instead of at the surface, this assumption might not be justified. Our aim is to explore the interactions of infalling planetesimals with primordial atmospheres at an embedded phase of evolution. We investigate effects of atmospheric interaction on the planetesimals (mass loss) and the atmosphere (heating/cooling). We used atmospheric parameters from a snapshot of time-dependent evolution simulations for embedded atmospheres and simulated purely radial, infall events of siliceous planetesimals in a 1D, explicit code. We implemented energy transfer between friction, radiation transfer by the atmosphere and the body and thermal ablation; this gives us the possibility to examine the effects on the planetesimals and the atmosphere. We find that a significant amount of gravitational energy is indeed dissipated into the atmosphere, especially for larger planetary cores, which consequently cannot contribute to the atmospheric planetary luminosity. Furthermore, we examine that planetesimal infall events for cores, $M_\mathrm{C} > 2$M$_{\oplus}$, which actually result in a local cooling of the atmosphere; this is totally in contradiction with the classical model

A psychological framework to enable effective cognitive processing in the design of emergency management information systems

Human cognitive processing and decision making are essential aspects in emergency management. Emergency situations imply additional demands to information processing. To meaningfully support decision makers in emergencies, a comprehensive understanding of the human perception and decision making processes and their underlying principles is required in the design of Emergency Management Information Systems (EMIS).This paper presents a psychological framework that models the stages and components of decision making in the context of emergency management. To this end, psychological research on human perception and information processing, knowledge and competence modelling, human judgement and decision making, individual and situational factors, stress, and self-regulation are identified as important compents of the framework. The psychological framework represents a comprehensive model of decision making of emergency managers, for a better understanding of the involved cognitive processes and influencing factors on the person level and on the context level. The paper posits the framework as a guide in the identification of requirements for emergency managers during systems analysis. This comprises systematically describing decision tasks in emergency situations and identifying needs for supporting them. The knowledge on human perception and decision making represented by the framework can also be used to inform the user interface design of the EMIS. It may also inform the evaluation of EMIS as it provides a theoretically founded representation of relevant aspects of human-computer interaction, which facilitates the identification of success indciators to be addressed in user-centred evaluation. The framework furthermore supports the design and implementation of training programmes through the differentiation and modelling of knowledge and competence relevant in emergency decision making. To demonstrate the application of the psychological framework in the design, development, and testing of EMIS a set of concrete design principles as well as exemplary paper prototypes applying these principles are presented

Orographic and convective gravity waves above the Alps and Andes mountains during GPS radio occultation events – a case study

The significant distortions introduced in the measured atmospheric gravity wavelengths by soundings other than in vertical and horizontal directions, are discussed as a function of elevation angle of the sounding path and the gravity waves aspect ratio. Under- or overestimation of real vertical wavelengths during the measurement process depends basically on the value of these two parameters. The consequences of these distortions on the calculation of the energy and vertical flux of horizontal momentum are analyzed and discussed in the context of two experimental limb satellite setups: GPS-LEO radio occultations and TIMED/SABER measurements. Possible discrepancies previously found between the momentum flux calculated from satellite temperature profiles, on site and from model simulations, may, to a certain degree, be attributed to these distortions. A recalculation of previous momentum flux climatologies based on these considerations seems to be a difficult goal.Fil: Hierro, Rodrigo Federico. Universidad Austral. Facultad de Ingeniería. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Steiner, Andrea K.. Universidad de Graz; AustriaFil: de la Torre, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Departamento de Ciencias Básicas; ArgentinaFil: Alexander, Pedro Manfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Llamedo Soria, Pablo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ingeniería. Departamento de Ciencias Básicas; ArgentinaFil: Cremades, Pablo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentin

Enemies, Adversaries & Unlikely Allies: Reimagining Agonal Democratic Theory Through a Classical Sociological Lens

Set against the backdrop of increasingly polarized and dysfunctional political discourse within western democratic nations, this dissertation aims to consider the ways in which critical sociology can contribute to, and potentially expand, emergent accounts of an alternative radical democratic politics premised on productive contest. While the mainstream of democratic theory remains dominated by notions of deliberation, compromise, and consensus; a challenge has emerged out of a small but important paradigm of social and political theory - one that conceptually re-prioritized the political ideal of agon. Rejecting notions of post-political compromise or consensus, contemporary scholars of agonal democracy propose perpetually open contest, legitimated struggles, and irresolvable tensions as the proper and desirable content of the political. Yet as richly as these varying accounts have mapped the political character of such agonal principles, very little attention has been paid to their implicit or explicit social dimensions. Through the creative adaptation of certain sociological perspectives of Max Weber, Ferdinand Tnnies, Georg Simmel, and Jrgen Habermas; this project attempts to rethink the social in the context of radical agonistic democracy. Taking up the work of Chantal Mouffe as an exemplar of this agonal paradigm, this project challenges the often-shallow accounts of the social, ultimately suggesting an alternative, though complimentary, theoretical vocabulary through which to explore the important, but consistently underexplored, social dimensions of a (re)turn to the political ideal of agon

Einfluss der Bluttalspiegel von Tacrolimusunter Berücksichtigung der Cytochrom P450 –Polymorphismen auf Rejektionshäufigkeit undTransplantatfunktion nachNierentransplantation

In der vorliegenden retrospektiven Arbeit werden 74 Patienten, welche zwischen Mai 2000 und Dezember 2005 am Universitätsklinikum Kiel eine Nierentransplantation (Lebend- sowie Kadaverspenden) erhalten hatten, untersucht. Ihre Immunsuppression besteht aus dem Calcineurininhibitor Tacrolimus in Kombination mit dem DNA-Synthesehemmer Mycophenolatmofetil (1g/die), Steroiden und einer Induktionstherapie. Ziel dieser Arbeit ist es, den Einfluss der Bluttalspiegel und/ oder der Dosierung von Tacrolimus innerhalb der ersten 30 Tage nach Transplantation auf die Rejektionshäufigkeit wie auch die Nierenfunktion im Verlauf nach Transplantation zu untersuchen. Um Fehlinterpretationen zu vermeiden, werden wichtige weitere Ko- Faktoren mit potentiellem Einfluss auf das Rejektionsverhalten mittels Multivarianzanalyse mit erfasst. Für die Analysen werden die 74 Patienten aufgrund des Merkmals Rejektion bzw. keine Rejektion in jeweils eine Gruppe eingeteilt. Folgende Ko-Faktoren haben keinen Einfluss auf die Gruppenzugehörigkeit: Alter, Geschlecht und Körpergewicht des Empfängers, die Art des Dialyseverfahrens vor Transplantation, Diabetes mellitus, arterielle Hypertonie, positiver CMV IgG-Status des Empfängers, Hepatitis B und C, maligne Tumoren. Signifikant assoziierte Ko-Faktoren mit einem Rejektionsereignis sind: ein HLAMismatch >3 und ein weibliches Spendergeschlecht. Die wesentliche Erkenntnis dieser Arbeit ist, dass zur Verhinderung eines Rejektionsereignisses nach Nierentransplantation ein Tacrolimus-Bluttalspiegel von 12 ng/ml in Kombination mit 1g MMF/die in der zweiten Woche nach Transplantation erreicht werden muss. Für den bisher angestrebten Zielbereich von 10-15 ng/ml sollte also die untere Grenze für die Bluttalspiegel auf 12 ng/ml angehoben werden, wenn eine Ko-Medikation mit 1g MMF und eine Induktionstherapie mit 40mg Basiliximab erfolgt. Auch wenn der Bluttalspiegel von Tacrolimus mehr als 7 mal in den ersten 14 Tagen nach Transplantation unter 12 ng/ml liegt, besteht eine höhere Rejektionsgefahr mit einem negativen Einfluss auf die Transplantatfunktion in einem Nachbeobachtungszeitraum von im Mittel 33 Monaten

A novel approach and software component for supporting competence-based learning with serious games

Digital educational games constitute a major opportunity for acquiring knowledge and competences in a different way than traditional classroom- and technology-based methods. This paper presents a novel approach for a game component that structures the game play in an adaptive way. This approach consists of a combination of three learning theories and techniques. First, Competence-based Knowledge Space Theory is used structure a knowledge domain into competences and game situations. Second, the Leitner system of flashcards is used to establish structured and timed repetition of competences to be acquired. Third, the Ebbinghaus forgetting curve is taken into account to model forgetting learned competences. This approach has been implemented as a game component in line with the games component architecture of the RAGE project. The design and development of this component followed the requirements of the French games company Kiupe that includes it in its environment of games and mini-games