Brain Death Determination

Patient MR was a seventeen year old female involved in a motor vehicle collision which resulted in a traumatic brain injury leading to declaration of brain death. The pathophysiology behind the traumatic brain injury, the concept and use of a brain tissue monitoring device, and the tests used in the declaration of brain death will be explored. When brain death is determined, the patient has the opportunity to become an organ donor. Thousands of people are waiting for organs to become available. This is a huge healthcare concern that may be decreased if the general public is more educated regarding the process of brain death determination. By having a better understanding of brain death, the hope is that there will be more people willing to make the decision to become an organ donor. In order to address the enormous need for organ donors, there has to be an understanding of brain death testing at the cellular level

Stochastic Integration

Differential equations have been used to model physical systems, but in many processes this has not been sufficient due to the presence of random occurrences in the system. One method of dealing with this problem is to model the system as a stochastic or random process. A stochastic process, x, is a function mapping the product of a probability space, Ω, and a subset of the real numbers, TcR, into the real numbers, x: Ω*T→R. In many physical situations, T can be thought of as representing time and Ω as all possible outcomes of the process. For a fixed t ∈T, xt(·) is a random variable, and for a fixed ωƐΩ, x (ω) is called a sample function for the stochastic process. (For notational convenience, a stochastic process xt(ω) will be denoted by xt, the outcome, ω, being understood.

Hydrodynamic attractors for the speed of sound in holographic Bjorken flow

The speed of sound is a central quantity in the exploration of the phase diagram of quantum chromodynamics, specifically through heavy ion collisions analyzed in the Beam Energy Scan at the Relativistic Heavy Ion Collider. Such collisions push the system generically far away from equilibrium, where thermodynamic quantities are not well-defined and the thermodynamic definition for the speed of sound becomes unreliable. In addition, the plasma is approximately boost invariant along the beamline, leading to initially large anisotropy between that direction and the transverse plane. Here, we extend the standard thermodynamic definition to calculate the speed of sound when the system is out of equilibrium, in particular, undergoing Bjorken flow. Then, we compute this out-of-equilibrium speed of sound in a holographic plasma, and demonstrate remarkable agreement with the hydrodynamic prediction. We show by Borel resummation that the holographic system has one attractor for this speed of sound longitudinal, and another transverse, to the direction of Bjorken expansion. Attractor times for various initial flow conditions show that reaching an attractor does not imply or require local thermal equilibrium. In the cases studied, reaching an attractor implies hydrodynamization (quantities evolve approximately according to hydrodynamics), justifying the name \emph{hydrodynamic attractor}.Comment: Version 2 updates: General revisions, further discussion of results and updated data which includes additional initial conditions. Main text 32 pages, total page number: 46 pages. 15 figures, 3 appendices. Comments welcome

Pro oder Kontra Nanotechnologie? Unterstützung von kritischem Denken und reflektiertem Urteilen im Museum

In the research framework proposed in this dissertation, science exhibitions are conceptualized as dynamic information spaces for knowledge building that are constituted by three major pathways of knowledge communication: museum-to-visitor, visitor-to-visitor, and visitor-to-museum knowledge communication. It is argued that advanced technologies have the potential to support all forms of visitor-to-visitor knowledge communication but additionally, they allow for new forms of knowledge communication among unacquainted visitors and beyond the actual museum visit. Central learning mechanisms are analysed, namely socio-cognitive conflict, internalization of social processes, giving and receiving help, argumentation, co-construction of knowledge/group cognition, and active participation in knowledge building with regard to their relevance for learning in science exhibitions. Prototypical advanced media applications in science exhibitions that address these mechanisms are presented. These analytical considerations are then applied to examine the learning potential of discussion terminals for the communication of emergent technologies and contemporary science topics. For this purpose, a specific exhibition about nanotechnology is used as context. The specific challenge in communicating contemporary science topics is the fact that these topics are often discussed controversially, and science museums therefore face the challenge to adequately represent the ongoing public debate around such issues and to support their visitors in critical thinking and reflective judgement. Discussion terminals are introduced as innovative kind of discussion-based media installations that both can foster individual opinion formation processes and allow for opinion exchange and debate among visitors. In a first study, the impact of expression of opinion and salience of arguments on participants’ argument repertoire, opinion quality, and attitudes towards nanotechnology was tested in a 2x2 experimental design. Expression of opinion was revealed to have an impact on the argument repertoire but was not sufficient for formation of high-quality opinions. In contrary, asking for an overall judgement only seems to trigger top-down processes of opinion formation, that is, opinions and attitudes are formed that are highly dependent from prior attitudes and beliefs (confirmation bias, belief bias). Salience of arguments, however, was shown to be important for the formation of well-founded opinions and attitudes that are independent from prior attitudes. However, the Ss still showed a myside bias in their essays on their personal opinion, that is, they were indeed enabled to generate a valid rationale to support their personal opinion but failed to integrate counterarguments and arguments to refute these counterarguments. This ability, however, is considered as major indicator for good informal reasoning and critical thinking. Thus, study 2 aims at specifying the potential of discussion-based installations to reduce the myside bias in judgement. Encountering disagreement at the discussion terminal was proposed to be a major promoter of critical thinking and reflective judgement: Both awareness of what other people think and some understanding why they think so should foster deliberate opinion formation that takes also counterarguments into account. The assumption that a major potential of discussion-based installations is confronting visitors with the opposing view of others was tested in a second study. Disagreement with others' judgement was shown to reduce the myside bias in the participants’ argument repertoire. Furthermore, disagreement led to higher scores in reflective judgement and improved quality of counterargument generation and rebuttal construction indicating that the study participants deliberately elaborated on the reasons why other people disagreed and were thereby enabled to construct valid rebuttals of others’ counterarguments. Both studies imply that a discussion terminal - when designed carefully - is a valuable facilitator of critical thinking and reflective judgement about contemporary science topics.Im Zentrum der Arbeit stehen die Konzepte „kritisches Denken“ und „reflektiertes Urteilen“: Moderne Wissenschaftsmuseen wollen heute nicht nur Faktenwissen vermitteln, sondern gerade bei gesellschaftlich relevanten und kontrovers diskutierten Wissenschaftsthemen den Besucher mit Perspektiven aus unterschiedlichen Wissenschaftsdisziplinen bekannt machen und ihn befähigen, sich selbst eine Meinung zum Thema zu bilden. Der Besucher muss dazu die Fähigkeit haben, relevante Argumente zu evaluieren, pro und kontra Perspektiven zu integrieren und somit ein eigenes reflektiertes Urteil zu bilden. Die Autorin führt Erkenntnisse der kognitiven Psychologie (reasoning and decision making), der Sozialpsychologie (attitude formation and change) und aus dem Bereich des naturwissenschaftlichen Unterrichts (classroom debate und argumentation) an um aufzuzeigen, dass Museumsbesucher in ihrem kritischen Denken und reflektiertem Urteilen gezielt unterstützt werden müssen. Demnach steht im Dissertationsprojekt auch die Frage im Vordergrund, wie man die Meinungsbildung zu komplexen und kontroversen Wissenschaftsthemen im Kontext einer Science & Technology-Ausstellung unterstützen kann. In Teil I der Dissertation wird das Setting „Wissenschaftsmuseum“ als komplexer Wissenskommunikationsraum konzeptualisiert, in dem vor allem der Kommunikation zwischen den Besuchen großes Potenzial für Wissenserwerb und Meinungsbildung zugesprochen wird. Zentrale Mechanismen des kollaborativen Lernens werden auf den Museumskontext übertragen. Insbesondere die Mechanismen „Argumentieren“ und „soziokognitiver Konflikt“ werden als zentral für die Unterstützung kritischen Denkens und reflektiertem Urteilens betrachtet. Diese analytische Betrachtung erlaubt in Teil II der Dissertation die Identifikation relevanter Faktoren für das Design innovativer Medienstationen, die diese Lernmechanismen explizit adressieren und damit auch das Potenzial haben, Meinungsbildung im Museum gezielt zu unterstützen. Da eine klare Konzeptualisierung kritischen Denkens und reflektierten Urteilens für den Kontext „Wissenschaftsmuseum“ bisher fehlte, erfolgt zunächst die Integration relevanter Erkenntnisse aus der kognitiven, der pädagogischen und der Sozialpsychologie sowie die Übertragung zentraler Konzepte und Indikatoren einer „guten“ Meinung aus den Forschungsbereichen Science Communication/Science Education und Public Opinion Research. Auf Basis dieser theoretischen Diskussion erfolgen sowohl eine sorgfältige Konzeptualisierung und die darauf aufbauende Operationalisierung von „kritischem Denken“ und „reflektiertem Urteilen“. Identifizierte relevante kognitive Prozesse sind dann die Grundlage für das Design einer Medieninstallation für eine Ausstellung zum Thema Nanotechnologie. Dabei wird der Trend aufgegriffen, im Rahmen von Ausstellungen zu aktuellen und kontrovers diskutierten Wissenschaftsthemen Medieninstallationen zum Meinungsaustausch zwischen Besuchern - so genannte Diskussions- oder Meinungsterminals - zu integrieren, an denen der Museumsbesucher die Möglichkeit zu hat, an aktuellen Debatten um wichtige Wissenschaftsthemen wie Gentechnik, Nanotechnologie oder Klimaänderung teilzunehmen, wichtige Perspektiven und Argumente kennen zu lernen, die eigene Meinung mitzuteilen und Meinungen anderer Besucher kennen zu lernen. Inwieweit ein Diskussionsterminal dazu beitragen kann, Wissenserwerb und Meinungsbildung zu dem sehr kontrovers diskutierten und ambivalenten Thema Nanotechnologie zu fördern, wurde in zwei Experimenten untersucht. Experiment 1 untersucht dabei vor allem den individuellen kognitiven Prozeß der Meinungsbildung. Studie 2 verknüpft theoretische Annahmen der kognitiven und der Sozialpsychologie, um den Effekt von konträren Besuchermeinungen auf das individuelle Urteil zu untersuchen. In beiden experimentellen Studien konnte nachgewiesen werden, dass das konzipierte Meinungsterminal kritisches Denken und reflektiertes Urteilen in Wissenschaftsmuseen unterstützen kann. Insbesondere die Salienz relevanter Pro- und Kontra-Argumente (Studie 1) erwies sich als ausschlaggebend für eine Bewertung, die unabhängig ist von Voreinstellungen. Die Möglichkeit, die Meinung anderer Besucher und dabei auch Gegenpositionen kennen zu lernen (Studie 2), trug in großem Maße dazu bei, dass auch Gegenargumente in die eigene Bewertung einfließen und somit die Qualität der eigenen Meinung steigt. In einer abschließenden Diskussion werden theoretische, methodische und praktische Implikationen ausführlich diskutiert

On becoming a leader in Asia and America: Empirical evidence from women managers

In concordance with recent calls for cross-cultural leadership research as well as research on women leaders, this study investigated how women in Asia and the U.S. become leaders and how they enact their leadership. In-depth interviews with 76 mid- to upper-level female managers in Asia (China, India, Singapore) and the U.S. were conducted. Analyses revealed that a simple dichotomy of “Asian” versus “Western” leadership did not appropriately describe the data. Rather, factors such as achievement orientation, learning orientation, and role models emerged as crucial success factors for advancement to leadership positions across continents. However, the particular meaning differed between countries. Furthermore, with regard to women's leadership style differences between Asian countries were more salient than between Asia and the U.S. Implications for leadership theory and practice are discussed