Physics Commons^™

Supersymmetric Yang-Mills Theories On The Lattice, Anosh Joseph

Physics - Dissertations

This dissertation reviews the formulation of twisted supersymmetric Yang--Mills (SYM) theories in the continuum and also on the lattice. We focus on the maximally supersymmetric twisted SYM theories in four and two dimensions. The one-loop renormalization of the lattice four-dimensional SYM theory is investigated. We also study the thermal phase structure of the maximally supersymmetric SYM in two dimensions and possible black hole transitions in its dual gravitational theory, using numerical simulations of the lattice theory.

Bioenergetics And Dynamics Of Ciliary Responses And Systems Biology Of Phototaxis In Chlamydomonas Reinhardtii, Suphatra Adulrattananuwat

Physics - Dissertations

The goal of this dissertation is to understand how a eukaryotic cell makes decisions. Chlamydomonas reinhardtii, a biciliated unicellular green alga, is used as our model organism. This organism has the ability to track the light using its photoreceptor called rhodopsin, which overlays the eyespot. The organism makes decisions to swim toward, away from, perpendicular to or to ignore the light using its slender arm-like structures called cilia. It can integrate several external inputs such as ion concentration and light intensity, and then process this information to adjust the steering of its cilia corresponding to its environment. We investigated how …

Morphology And Mechanics Of The Actin Cytoskeleton, David Aaron Quint

Physics - Dissertations

Contained in this thesis is the quest to model the growth, form and mechanics of part of the cellular cytoskeleton known as the lamellipodium. The cellular cytoskeleton is made of filamentous proteins, such as F-actin, and provides for structural support for the cell. Lamellipodia are extensions of the cellular cytoskeleton at the leading edge of a crawling cell generated so that the cell can extend, and thereby move in a particular direction. In the first two chapters, we focus on morphological characteristics of lamellipodia formation, which is, in part, shaped by branched filament nucleation via the branching protein Arp2/3. For …

Measuring Dose To Small Animals In Micro-Ct, Avi Hameroff

Honors Capstone Projects - All

An important application of William Röntgen’s discovery of x-rays is computed tomography (CT). First developed in the 1970’s, CT scanners of today are able to provide a detailed image of a patient’s body with minimal risk to patient and a very short turnaround time from scan to reconstructed image. This powerful tool provides physicians another way to diagnose patients while simultaneously allowing for researchers to learn about the human body.

Scientists soon became interested in using the technology on small animals but practical issues plagued the widespread use of CT in preclinical research. The scale of the scanners was simply …

Spiral Patterns In Liquid Crystals, Gavin Hartnett

Honors Capstone Projects - All

Abstract not Included

Intracellular Signaling: How Do Cells Respond To Single And Multiple Inputs, Latoya Crayton

Honors Capstone Projects - All

One important biological question is how the cell processes input information and decides what to respond. The cell can integrate the multiple inputs using linear and nonlinear dynamics to generate an appropriate output. This study focuses on the computerized recording of phototaxis (movement in relation to light direction) of Chlamydomonas cell populations response to green light, which activates the rhodopsin photoreceptor at their eyespots. The inputs are light stimulation of various wavelengths and intensities; and chemicals (IBMX, a PDE inhibitor; 2'5'-dideoxyadenosine, an adenylate cyclase inhibitor, 8-Br-cAMP-Na and Dibutyryl cAMP, cAMP analogs) affecting an important intracellular messenger, cAMP. The quantified output …

Studies On Novel Semiconductor Detectors And Front-End Electronics For Heavy Flavor Decay Studies, Gustavo Kertzscher

Honors Capstone Projects - All

I have studied novel semiconductor detectors designed to provide precise space point information of the trajectory of charged subatomic particles produced in high energy physics (HEP) collisions. The technological thrust aims toward maintaining good performance of these detectors in a hard radiation environment for an extended period of time. My studies approached two different types of silicon devices: a whole wafer comprised of test structures and pixel devices designed for the inner vertex detector of the BTeV experiment, and small test structures of a novel type of quasi-3D detectors developed in the context of the CERN RD50 collaboration. This collaboration …

Photo-Induced Current Measurements In Chlamydomonas Cell Suspensions, Collin D. Capano

Honors Capstone Projects - All

In order to fully understand the principles behind phototaxis in flagellate algae, it is necessary to measure the electric currents these cells create when processing light stimuli. Many different techniques have been developed to do this. One of these techniques, measuring from cell suspensions, has a number of advantages over the others that makes it highly desirable. However, the lab that first developed this method of recording did not describe the setup very well. The result is that in the thirteen years since it was first reported, only one other independent lab has been able to reproduce the results despite …