Graduate Recital:David Conditt, Trombone Gloria Cardoni, Piano

Kemp Recital Hall Sunday Afternoon November 7, 1999 5:30 P.M

Current Approaches to the Study of Movement Control

A combination of neural recording, behavioural experiments and computational modeling is needed to understand the control of movemen

Social Organization of \u3cem\u3eNeotoma micropus\u3c/em\u3e, the Southern Plains Woodrat

This study described the social organization of Neotoma micropus, the southern plains woodrat, using radiotelemetry. We studied woodrats from September 1994 through April 1995 at the Urban Wilderness Reserve in S Bexar County, Texas. Sixteen individuals (three adult males, 11 adult females, and two subadult males) were radiocollared and located in the evening or early morning during January and February. Seventy-four percent of female radiolocations and 57% of male radiolocations were from their respective nests. No more than one adult individual was observed at any nest at the same time. Males had significantly larger (x = 1899 m2) home ranges than females (x = 220 m2). Male home ranges overlapped female home ranges more (35.9%) than female ranges overlapped other female home ranges (11.9%). Survival rates were similar for males and females. The results confirm previous studies indicating that these woodrats are asocial. The spacing of male and female home ranges indicated that these woodrats probably have a promiscuous mating system

Collaborative video game design work and diversity

The video game design industry is one of the most significant fields for both producing and using Information and Communication Technologies (ICTs) today. Many industry leaders, researchers, and players continue to argue that diverse representation in both games and the workforce matters for the health of the industry and for an equitable society. Very little research thus far, however, has directly considered how to better support diversity within collaborative video game design work. I identified three concrete areas to study diversity within this field (understanding the structure of organizations, understanding collaborative work tool selection and use, and broadening the participation of underrepresented and marginalized groups) and developed three corresponding research questions. I addressed these questions by employing qualitative methods of multi-sited ethnography, digital ethnography, and modified grounded theory. I conducted 20 semi-structured interviews with game designers in different job roles within 19 different organizations; these interviews drew out instances related to diversity in participants’ daily practices and experiences. I then analyzed all interview data using an iterative process of thematic analysis, guided by my modified grounded theory approach. I inductively developed a list of salient structural features of participants’ video game design organizations that is directly based on their discussions, including: size, task division and allocation, coordination, decision making, and recruitment and hiring. I additionally developed a list of significant rationales for how and/or why particular tools were selected, including: fitting an existing workflow; size; cost; the influence of upper management; ubiquity or industry standard; ease of use; and familiarity with the tool. Both of these ontologies can be used to examine specific effects of diversity within an organization and to suggest changes accordingly. In addition to these conceptual contributions, I generated concrete recommendations that can be used to support the inclusion of underrepresented and marginalized groups within video game design organizations; these suggestions emphasize a need to place diverse people in diverse positions within an organization and to overcome the hiring conundrum. The conceptual and practical contributions of this dissertation can therefore positively impact diverse stakeholders within the video game industry and related research fields.Informatio

Patient-Specific Unicompartmental Knee Resurfacing Arthroplasty: Use of a Novel Interference Lock to Reduce Tibial Insert Micromotion and Backside Wear

Micromotion has long been associated with wear of polyethylene tibial inserts, potentially causing failure of unicompartmental knee replacement systems. One cause of micromotion is the locking mechanism between the undersurface of the polyethylene and the tibial tray. The objective of this study was to investigate the use of new novel lock designs for reducing the micromotion associated with a patient specific tibial implant. Micromotion occurring between the tibial insert and tibial tray was measured using the DVRT method for two new lock designs and compared to the micromotion measured for the prior generation lock design. In total, 18 samples were tested, six in each of the three designs: prior generation CLEARANCE lock design, new LINE-TO-LINE design, new INTERFERENCE design

Contralateral manual compensation for velocity-dependent force perturbations

It is not yet clear how the temporal structure of a voluntary action is coded allowing coordinated bimanual responses. This study focuses on the adaptation to and compensation for a force profile presented to one stationary arm which is proportional to the velocity of the other moving arm. We hypothesised that subjects would exhibit predictive coordinative responses which would co-vary with the state of the moving arm. Our null hypothesis is that they develop a time-dependent template of forces appropriate to compensate for the imposed perturbation. Subjects were trained to make 500 ms duration reaching movements with their dominant right arm to a visual target. A force generated with a robotic arm that was proportional to the velocity of the moving arm and perpendicular to movement direction acted on their stationary left hand, either at the same time as the movement or delayed by 250 or 500 ms. Subjects rapidly learnt to minimise the final end-point error. In the delay conditions, the left hand moved in advance of the onset of the perturbing force. In test conditions with faster or slower movement of the right hand, the predictive actions of the left hand co-varied with movement speed. Compensation for movement-related forces appeared to be predictive but not based on an accurate force profile that was equal and opposite to the imposed perturbatio

Two-year longitudinal evaluation of a second-generation thin-strut sirolimus-eluting bioresorbable coronary scaffold with hybrid cell design in porcine coronary arteries

Background: The first commercially available bioresorbable scaffold (BRS) had a strut thickness of 156 microns. As such, it had the potential for delivery challenges and higher thrombogenicity. The aim herein, is to evaluate biomechanical performance, pharmacokinetics and vascular healing of a novel thin strut (100 μm) sirolimus eluting BRS (MeRes-100, Meril Life Sciences, Gujarat, India) against the once clinically used BRS (Absorb BVS, Abbott, Santa Clara, CA) in porcine coronary arteries. Methods: Following device implantation, angiographic and optical coherence tomography (OCT) evaluation were performed at 45, 90, 180 days, 1 year and 2 years. Histological evaluation was per­formed at 30, 90 and 180 days. Results: At 2 years, both lumen (MeRes-100 7.07 ± 1.82 mm2 vs. Absorb BVS 7.57 ± 1.39 mm2, p = NS) and scaffold areas (MeRes-100 9.73 ± 1.80 mm2 vs. Absorb BVS 9.67 ± 1.25 mm2, p = NS) were comparable between tested and control scaffolds. Also, the late lumen area gain at 2 years was similar in both groups tested (MeRes-100 1.03 ± 1.98 mm2 vs. Absorb BVS 0.85 ± 1.56 mm2, p = NS). Histologic examination up to 6 months showed comparable healing and inflammation profiles for both devices. Conclusions: The novel sirolimus-eluting BRS with thinner struts and hybrid cell design showed similar biomechanical durability and equivalent inhibition of neointimal proliferation when compared to the first-ever Absorb BVS up to 2 years in normal porcine coronary arteries

Optimizing flushing parameters in intracoronary optical coherence tomography: an in vivo swine study

Intracoronary optical frequency domain imaging (OFDI), requires the displacement of blood for clear visualization of the artery wall. Radiographic contrast agents are highly effective at displacing blood however, may increase the risk of contrast-induced nephropathy. Flushing media viscosity, flow rate, and flush duration influence the efficiency of blood displacement necessary for obtaining diagnostic quality OFDI images. The aim of this work was to determine the optimal flushing parameters necessary to reliably perform intracoronary OFDI while reducing the volume of administered radiographic contrast, and assess the influence of flushing media choice on vessel wall measurements. 144 OFDI pullbacks were acquired together with synchronized EKG and intracoronary pressure wire recordings in three swine. OFDI images were graded on diagnostic quality and quantitative comparisons of flushing efficiency and intracoronary cross-sectional area with and without precise refractive index calibration were performed. Flushing media with higher viscosities resulted in rapid and efficient blood displacement. Media with lower viscosities resulted in increased blood-media transition zones, reducing the pullback length of diagnostic quality images obtained. Flushing efficiency was found to increase with increases in flow rate and duration. Calculations of lumen area using different flushing media were significantly different, varying up to 23 % (p < 0.0001). This error was eliminated with careful refractive index calibration. Flushing media viscosity, flow rate, and flush duration influence the efficiency of blood displacement necessary for obtaining diagnostic quality OFDI images. For patients with sensitivity to contrast, to reduce the risk of contrast induced nephrotoxicity we recommend that intracoronary OFDI be conducted with flushing solutions containing little or no radiographic contrast. In addition, our findings show that careful refractive index compensation should be performed, taking into account the specific contrast agent used, in order to obtain accurate intravascular OFDI measurements.Merck & Co., Inc.National Institutes of Health (U.S.) (Grant Numbers R00CA134920, R01HL076398, R01HL093717