Multigrid-reduction-in-time for Eddy Current problems

Parallel-in-time methods have shown success for reducing the simulation time of many time-dependent problems. Here, we consider applying the multigrid-reduction-in-time (MGRIT) algorithm to a voltage-driven eddy current model problem.Comment: Contribution from GAMM 2019 conferenc

Research Proposal: The Effects of Alcohol on the Social Aspects of High School Students

Although the legal drinking age is twenty-one, the age that a person begins to consume alcohol is decreasing. In a study in 1997, the average age of first alcohol use was 13.2 years old ( Maney, Higham-Gardill, & Mahoney, 2002). Drinking alcohol at a young age can lead to social problems and even delinquent behavior. It has been said that adolescent alcohol misuse has been shown to be part of a constellation of problem behaviors including delinquency and illicit drug use (Barnes, Welte, & Hoffman, 2002). Not only does it aid in future delinquency but also antisocial personality and health problems. Several studies have been done to discover the age and occurrences in which adolescents begin drinking and the possible consequences including but not limited to delinquent behavior, illicit drug use, sexual activity and longitudinal studies that project adult alcoholism. The main question in this particular research is to investigate if high school students who consume alcohol have a higher rate of social problems than those students who do not consume alcohol do. The reason for this research is the personal observance of adolescents who abuse alcohol, which resulted in problems with school and family life

Do You Know Your 50 States?

When information is forgotten, sometimes a visual cue can act as a spark to cue your memory into remembering the lost facts. In this study, the task at hand is recalling as many of the 50 United States as possible. Twenty undergraduate students were randomly assigned into two groups, where the first group’s task was free recall of the 50 states and the second group received a blank map of the states to test cued recall. This memory task may sound like an easy one but recalling the United States of America is tougher than participants imagined. However, there was no difference in the mean number of states recalled between the free recall condition and the cued recall condition

Bras and Ballots: Comparing Women’s Political Participation in Pakistan and Saudi Arabia

22 pagesThis article explores the dichotomy between women’s political participation in Pakistan and Saudi Arabia

Stochastic Modelling of Calcium Dynamics

Calcium (Ca2+) ist ein in eukaryotischen Zellen allgegenwärtiger sekundärer Botenstoff. Durch Inositoltrisphosphat (IP3) ausgelöste Ca2+-Signale von IP3-Rezeptoren (IP3Rs) sind eines der universellsten Zell Signalübertragungssysteme. Ca2+ Signale sind fundamental stochastisch. Dennoch hat sich die Modellierung dieser Ca2+-Signale bisher stark auf deterministische Ansätze mit gewöhnlichen Differentialgleichungen gestützt. Diese wurden als Ratengleichungen etabliert und beruhen auf räumlich gemitteltem Ca2+ Werten. Diese Ansätze vernachlässigen Rauschen und Zufall. In dieser Dissertation präsentieren wir ein stochastisches Modell zur Erzeugung von Ca2+ Spikes in Form einer linearen Zustands-Kette. Die Anzahl offener Cluster ist die Zustandsvariable und Erholung von negativem Feedback wird berücksichtigt. Wir identifizieren einen Ca2+ Spike mit dem ersten Erreichen eines kritischen Zustands und sein Interspike Intervall mit der first-passage time (FPT) zu diesem Zustand. Dafür entwickeln wir einen allgemeinen mathematischen Rahmen zur analytischen Berechnung von FPTs auf solch einer Kette. Wir finden z.B. einen allgemein verringerten CV, der ein deutliches Minimum in Abhängigkeit der Zustandskettenlänge N aufweist. Dies nennen wir resonante Länge. Danach ergänzen wir positives Feedback und wenden das Modell auf verschiedene Zelltypen an. Es erfasst alle verfügbaren allgemeinen Beobachtungen zu Ca2+ Signalvorgängen. Es erlaubt uns Einblicke in den Zusammenhang von Agonistenstärke und Puffraten. Auch werden einzelne Ca2+ Spikes in Purkinje Neuronen, welche eine Rolle für Lernen und Erinnerung spielen, als stochastisches reaction-diffusion Model in einer 3D Dornenfortsatz Geometrie modelliert. Ataxia, eine Krankheit, die zum Verlust der Feinmotorik führt, wird auf defekte IP3R zurückgeführt, die abnormale Ca2+ Spikes erzeugen. Dieser Zustand wird ebenfalls untersucht und es wird ein Weg zur Wiederherstellung normaler Ca2+ Spikes vorgeschlagen.Calcium (Ca2+) is a ubiquitous 2nd messenger molecule in all eukaryotic cells. Inositol trisphosphate (IP3)-induced Ca2+ signalling via IP3 receptors (IP3Rs) is one of the most universal signalling systems used by cells to transmit information. Ca2+ signalling is noisy and a fundamentally stochastic system. Yet, modelling of IP3-induced Ca2+ signalling has relied heavily on deterministic approaches with ordinary differential equations in the past, established as rate equations using spatially averaged Ca2+. These approaches neglect the defining features of Ca2+ signalling, noise and fluctuations. In this thesis, we propose a stochastic model of Ca2+ spike generation in terms of a linear state chain with the number of open clusters as its state variable, also including recovery from negative feedback. We identify a Ca2+ spike with reaching a critical state for the first time, and its interspike interval with the first passage time to that state. To this end, a general mathematical framework for analytically computing first-passage times of such a linear chain is developed first. A substantially reduced CV with a pronounced minimum, dependent on the chain length N, termed resonant length, are found. Positive feedback is then included into the model, and it is applied directly to various cell types. The model is fundamentally stochastic and successfully captures all available general observations on Ca2+ signalling. Also, we specifically study single Ca2+ spikes in spines of Purkinje neurons, assumed to be important for motor learning and memory, using MCell to simulate a reaction-diffusion system in a complex 3D Purkinje spine geometry. The model successfully reproduces experimentally findings on properties of Ca2+ spikes. Ataxia, a pathological condition resulting in, e.g., a loss of fine motor control, assumed to be caused by malfunctioning IP3Rs, is modelled and a possible way of recovery is suggested

Are You Up To Date?

If an individual is up to date on current events, it makes it easier to carry on or even start a conversation with another individual who is also up to date. The researchers feel that individuals aged 40 and over are more up to date on current events than those ages 18- 25. In the current study, 46 participants; 26 participants aged 18-25 years old and 20 participants aged 40 years and older, recruited from the St. Charles area, took a ten question questionnaire on current events. The participants were divided by age and gender, so the study had a representative sample. Results showed t (44) =2.888, p=.003. The researchers had to reject the null hypothesi