An interpretation of the personality of Isaiah through a study of his writings

Typewritten sheets in cover. Thesis (M.A.)--Boston University [Bibliography]: p. 76-80

Octopus-Inspired Grasp-Synergies for Continuum Manipulators

Human operation of continuum “continuous-backbone” manipulators remains difficult, because of both the complex kinematics of these manipulators and the need to coordinate their many degrees of freedom. We present a novel synergy-based approach for operator interfaces, by introducing a series of octopus-arm inspired grasp-synergies. These grasp-synergies automatically coordinate the degrees of freedom of the continuum manipulator, allowing an operator to perform kinematically complex grasping motions through simple and intuitive joystick inputs. This effectively reduces the complexity of operation and allows the operator to devote more of his attention to higher-level concerns (e.g. goal, environment). We demonstrate the grasp-synergies interface design in both simulation and hardware using the nine degree of freedom Octarm continuum manipulator

Haptic Displayof Realistic Tool Contact via Dynamically Compensated Control of a Dedicated Actuator

High frequency contact accelerations convey important information that the vast majority of haptic interfaces cannot render. Building on prior work, we present an approach to haptic interface design that uses a dedicated linear voice coil actuator and a dynamic system model to allow the user to feel these signals. This approach was tested through use in a bilateral teleoperation experiment where a user explored three textured surfaces under three different acceleration control architectures: none, constant gain, and dynamic compensation. The controllers that use the dedicated actuator vastly outperform traditional position-position control at conveying realistic contact accelerations. Analysis of root mean square error, linear regression, and discrete Fourier transforms of the acceleration data also indicate a slight performance benefit for dynamic compensation over constant gain

Dimensional Reduction of High-Frequencey Accelerations for Haptic Rendering

Haptics research has seen several recent efforts at understanding and recreating real vibrations to improve the quality of haptic feedback in both virtual environments and teleoperation. To simplify the modeling process and enable the use of single-axis actuators, these previous efforts have used just one axis of a three-dimensional vibration signal, even though the main vibration mechanoreceptors in the hand are know to detect vibrations in all directions. Furthermore, the fact that these mechanoreceptors are largely insensitive to the direction of high-frequency vibrations points to the existence of a transformation that can reduce three-dimensional high-frequency vibration signals to a one-dimensional signal without appreciable perceptual degradation. After formalizing the requirements for this transformation, this paper describes and compares several candidate methods of varying degrees of sophistication, culminating in a novel frequency-domain solution that performs very well on our chosen metrics

High Frequency Acceleration Feedback Significantly Increases the Realism of Haptically Rendered Textured Surfaces

Almost every physical interaction generates high frequency vibrations, especially if one of the objects is a rigid tool. Previous haptics research has hinted that the inclusion or exclusion of these signals plays a key role in the realism of haptically rendered surface textures, but this connection has not been formally investigated until now. This paper presents a human subject study that compares the performance of a variety of surface rendering algorithms for a master-slave teleoperation system; each controller provides the user with a different combination of position and acceleration feedback, and subjects compared the renderings with direct tool-mediated exploration of the real surface. We use analysis of variance to examine quantitative performance metrics and qualitative realism ratings across subjects. The results of this study show that algorithms that include high-frequency acceleration feedback in combination with position feedback achieve significantly higher realism ratings than traditional position feedback alone. Furthermore, we present a frequency-domain metric for quantifying a controller\u27s acceleration feedback performance; given a constant surface stiffness, the median of this metric across subjects was found to have a significant positive correlation with median realism rating

VerroTouch: High-Frequency Acceleration Feedback for Telerobotic Surgery

The Intuitive da Vinci system enables surgeons to see and manipulate structures deep within the body via tiny incisions. Though the robotic tools mimic one\u27s hand motions, surgeons cannot feel what the tools are touching, a striking contrast to non-robotic techniques. We have developed a new method for partially restoring this lost sense of touch. Our VerroTouch system measures the vibrations caused by tool contact and immediately recreates them on the master handles for the surgeon to feel. This augmentation enables the surgeon to feel the texture of rough surfaces, the start and end of contact with manipulated objects, and other important tactile events. While it does not provide low frequency forces, we believe vibrotactile feedback will be highly useful for surgical task execution, a hypothesis we we will test in future work

Multidisciplinary Assessment Of The Removal Of A Small Run-Of-River Dam In The Southern Appalachian Mountains

Dam removals are a commonly employed tool of water resource managers for stream restoration projects. Most dam removals are performed without the accompaniment of a scientific study to evaluate their efficacy or biological consequences, and many of the ones which are studied are situated in low gradient, warmwater streams. The removal of the Ward Mill Dam on the Watauga River in the Appalachian Mountains of North Carolina provided an ideal case study for a dam removal in a moderate gradient, coolwater stream. Benthic macroinvertebrate samples were collected and sediments surveyed from 8 sites along the Watauga River for 6 months following the dam removal to identify the downstream extent and temporal persistence of changes to the benthic community. Sites further than 1 km downstream of the dam showed moderate to extreme long-lasting alterations to the median streambed particle size, but few changes to the benthic community. Sites within the former impoundment and immediately downstream of the dam experienced drastic changes to channel morphology and macroinvertebrate community structure. At 6 months post removal nearly all benthic community metrics had recovered to reference condition. This suggests that headwater streams may recover more slowly to geomorphic changes following dam removals, however benthic macroinvertebrate communities rebound quickly to refill the vacated ecological roles following the disturbance

Modular assembly of transposable element arrays by microsatellite targeting in the guayule and rice genomes

Abstract Background: Guayule (Parthenium argentatum A. Gray) is a rubber-producing desert shrub native to Mexico and the United States. Guayule represents an alternative to Hevea brasiliensis as a source for commercial natural rubber. The efficient application of modern molecular/genetic tools to guayule improvement requires characterization of its genome. Results: The 1.6 Gb guayule genome was sequenced, assembled and annotated. The final 1.5 Gb assembly, while fragmented (N50 =22 kb), maps >95% of the shotgun reads and is essentially complete. Approximately 40,000 transcribed, protein encoding genes were annotated on the assembly. Further characterization of this genome revealed 15 families of small, microsatellite-associated, transposable elements (TEs) with unexpected chromosomal distribution profiles. These SaTar (Satellite Targeted) elements, which are non-autonomous Mu-like elements (MULEs), were frequently observed in multimeric linear arrays of unrelated individual elements within which no individual element is interrupted by another. This uniformly non-nested TE multimer architecture has not been previously described in either eukaryotic or prokaryotic genomes. Five families of similarly distributed non-autonomous MULEs (microsatellite associated, modularly assembled) were characterized in the rice genome. Families of TEs with similar structures and distribution profiles were identified in sorghum and citrus. Conclusion: The sequencing and assembly of the guayule genome provides a foundation for application of current crop improvement technologies to this plant. In addition, characterization of this genome revealed SaTar elements with distribution profiles unique among TEs. Satar targeting appears based on an alternative MULE recombination mechanism with the potential to impact gene evolution. Keywords: Natural rubber, Genome, Assembly, Annotation, Class II transposable element, Non-autonomous, Transposo

Berkeley Accelerator Space Effects (BASE) Light Ion FacilityUpgrade

The BASE Light Ion Facility upgrades have been completed. All proton beams are now delivered to Cave 4A. New control software, a larger diameter beam window, and improved quality assurance measures have been added

The influence of chronotype on the body mass index of U.S. college students

Objectives: The relationship between a college student’s chronotype and body mass index (BMI) is important to understand for university decision makers who want to build healthy and inclusive academic communities. This study aimed to evaluate how a student’s chronotype influences their BMI. Material and Methods: Participants were college students from Oral Roberts University (n=384) with a mean age of 18.94 years, a mean BMI of 24.7kg/m2, and a mean morningness-eveningness questionnaire (MEQ) score of 47.65. Results: BMI values were significantly correlated with both chronotype (r=-.11, β=-.09, p=.03) and age (r=.12, β=.53, p=.02). The rate at which BMI increased with age depended upon the student’s chronotype (β=.81-.005 / MEQ, p=.005). The later the chronotype, the higher the rate of increase. Race had no significant influence on MEQ or BMI values except in the case of students who identified as Black and female. These students were found, on average, to have significantly higher BMI values (p<.01). Conclusion: For college students, BMI tends to increase over time and at a rate that is dependent upon chronotype. The later the chronotype, the faster the rate at which BMI increases. BMI values were found to be significantly higher for Black females. However, this result is potentially spurious, as BMI does not take into account differences in body composition between genders and race/ethnicity groups