Investigating the mechanisms of surface sensing using motility appendages by Pseudomonas aeruginosa PA14

Biofilms are surfaced attached communities of cells encased in an extracellular matrix. The transition from free-swimming planktonic cells to a surface attached biofilm begins with cellular changes that occur after surface contact. This process is known as surface sensing and the opportunistic pathogen Pseudomonas aeruginosa PA14 uses its two motility appendages, type IV pili (T4P) and a single, polar flagellum to sense and traverse surfaces. The first cellular changes to occur within this organism upon surface contact is an increase in the second messengers cAMP and cdi- GMP. While the genes involved in surface sensing by P. aeruginosa are known, the mechanism by which these molecular machines sense and relay surface contact to the rest of the cell has remained a mystery. This thesis focuses on how T4P and flagellar surface contact lead to increases in cAMP and c-di-GMP, respectively. I show that the primary T4P retraction motor likely relays a surface signal to the Pil-Chp system, leading to CyaB activation and cAMP production. I also present data that supports a model whereby the stators of the flagellar motor senses surface contact and relay this information to a diguanylate cyclase leading to c-di-GMP production. These studies demonstrate how mechanical perturbations to these molecular motility machines upon surface contact can serve as cellular signals to initiate biofilm formation

Captive Soul: A Work for String Quartet in Four Movements

Captive Soul is a work for string quartet in four movements. It was written in part to fulfill the requirements for the Master’s degree in Music Composition and is the primary subject of this thesis. Inspiration for the work was drawn from the composer’s own experiences. The composition was completed in March 2005 by James R. Geiger using a M-Audio Keystation 49-E, a Macintosh G3 computer, and an Edirol SoundCanvas SC-88ST tone module. The notation of the score was completed in April 2005 using Finale 2003 from Coda Software. It is approximately seventeen minutes and thirty seconds (17’30”) in duration. The purpose of this study is to place the composition in historical perspective, examine its structural elements within the context of similar genres, and explain the compositional procedures used. In particular, the study of Captive Soul will involve a discussion of elements such as form, melody, harmony, rhythm, and texture in the work and the similar use of these elements in works by prominent composers of the twentieth century. The compositions to be examined are: String Quartet No.2, String Quartet No. 3, and Symphony No. 3 “Liturgique” by Arthur Honegger, Petite Symphonie Concertante and Etudes for String Orchestra by Frank Martin, and Lyric Suite for String Quartet by Alban Berg

Asynchronous Discrete Event Schemes for PDEs

A new class of asynchronous discrete-event simulation schemes for advection-diffusion-reaction equations are introduced, which is based on the principle of allowing quanta of mass to pass through faces of a Cartesian finite volume grid. The timescales of these events are linked to the flux on the the face, and the schemes are self-adaptive, local in time and space. Experiments are performed on realistic physical systems related to porous media flow applications, including a large 3D advection diffusion equation and advection diffusion reaction systems. The results are compared to highly accurate results where the temporal evolution is computed with exponential integrator schemes using the same finite volume discretisation. This allows a reliable estimation of the solution error. Our results indicate a first order convergence of the error as a control parameter is decreased

Paratesticular desmoplastic small round cell tumors: A case report and review of the literature

Desmoplastic small round cell tumor (DSCRT) is a rare malignancy most often seen in the abdomen or pelvis of young men. Unfortunately, this disease is usually metastatic at diagnosis and has dismal outcomes. We describe a case of isolated paratesticular DSCRT in a 14â yearâ old male successfully treated with surgical resection, chemotherapy, and adjuvant radiation, and we present a review of the relevant literature. It appears that isolated, paratesticular DSCRTs have a markedly better outcome than the classic abdominal or pelvic location. We hypothesize that this is due to earlier detection and the relative ease of surgical resection.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138864/1/pbc26631.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138864/2/pbc26631_am.pd

Robotic Repair of Congenital Paraesophageal Hiatal Hernia

Abstract Congenital paraesophageal hiatal hernias are rare and can be associated with gastric incarceration, volvulus, mucosal ulceration, and anemia. Primary repair of the hernia and fundoplication are recommended. In this paper, we report a case of a 3-year-old child with abdominal pain who was noted to have a paraesophageal hiatal hernia with partial gastric volvulus. A 5 mm robot platform was utilized to facilitate hernia sac dissection, hiatal repair, and fundoplication.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63210/1/lap.2008.0185.pd

Robotic resection of recurrent pediatric lipoblastoma

This case demonstrates successful resection of a rare, recurrent presacral‐pelvic lipoblastoma in a 19‐year‐old female patient. Because of the anatomical location of the mass and its proximity to vital structures, the robotic approach allowed for both optimal visualization and effective debulking of the mass. Furthermore, with the use of an articulating laparoscopic camera, key visualization of the posterior lateral pelvis was possible. Using a wide breadth of technologies and resources is essential to broadening the surgical armamentarium and achieving resectability in otherwise challenging cases.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147748/1/ases12493_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147748/2/ases12493.pd

The Effects of Using Alkali-Silica Reaction Affected Recycled Concrete Aggregate in Hot Mix Asphalt

The effects of using alkali-silica reaction (ASR) affected recycled concrete aggregate (ASR-RCA) in hot mix asphalt (HMA) were investigated in this study. Dilatometer and modified beam tests were performed to determine the possibility of new ASR occurring in reactive aggregates within the HMA or re-expansion of existing gel. The Lottman test and micro-calorimeter were used to determine the moisture susceptibility of HMA made with ASR-RCA. A differential scanning calorimeter (DSC) with thermogravimetric analysis (TGA) was used to evaluate the drying of an artificial gel and x-ray diffraction (XRD) was used to check for the potential presence of gel in the filler fraction of the ASR-RCAs. Micro-deval and freeze-thaw tests were evaluated for their potential to indicate the presence of excess micro-cracks or ASR gel. Expansion testing indicated that both ASR-RCAs were still reactive with 0.5 N NaOH solution saturated with calcium hydroxide (CH) at 60 degrees C. Dilatometer testing of HMA specimens in NaOH CH solution at 60 degrees C indicated a reaction between the asphalt binder and the solution, but little, if any, ASR. The lack of expansion in the modified beam test supports the binder-solution interaction. However, dilatometer testing in deicer solution at the same temperature indicated that some ASR may have occurred along with the primary binder-solution interaction. The volume change characteristics associated with the binder-solution interaction with and without ASR was supported by the change in pH and alkali concentration of the test solution. DSC/TGA testing indicated that the artificial gel dehydrated at approximately 100 degrees C. XRD analysis of the filler indicated that some gel may have accumulated in this fraction. Moisture damage testing indicated good resistance to moisture damage by HMA mixtures made with ASR-RCA especially compared to a virgin siliceous aggregate. Micro-deval and freeze-thaw tests can detect the presence of micro-cracks due to ASR in ASR-RCAs as higher mass loss than the virgin aggregate. The potential distress mechanisms that may occur when using ASR-RCA in an HMA pavement were identified. Results obtained using accelerated laboratory conditions were extrapolated based on anticipated field conditions. Guidelines for the mitigation of potential distresses in HMA made with ASR-RCA are presented