Constrained Collective Movement in Human-Robot Teams

This research focuses on improving human-robot co-navigation for teams of robots and humans navigating together as a unit while accomplishing a desired task. Frequently, the team’s co-navigation is strongly influenced by a predefined Standard Operating Procedure (SOP), which acts as a high-level guide for where agents should go and what they should do. In this work, I introduce the concept of Constrained Collective Movement (CCM) of a team to describe how members of the team perform inter-team and intra-team navigation to execute a joint task while balancing environmental and application-specific constraints. This work advances robots’ abilities to participate along side humans in applications such as urban search and rescue, firefighters searching for people in a burning building, and military teams performing a building clearing operation. Incorporating robots on such teams could reduce the number of human lives put in danger while increasing the team’s ability to conduct beneficial tasks such as carrying life saving equipment to stranded people. Most previous work on generating more complex collaborative navigation for human- robot teams focuses solely on using model-based methods. These methods usually suffer from the need for hard coding the rules to follow, which can require much time and domain knowledge and can lead to unnatural behavior. This dissertation investigates merging high-level model-based knowledge representation with low-level behavior cloning to achieve CCM of a human-robot team performing collaborative co-navigation. To evaluate the approach, experiments are performed in simulation with the detail-rich game design engine Unity. Experiments show that the designed approach can learn elements of high-level behaviors with accuracies up to 88%. Additionally, the approach is shown to learn low-level robot control behaviors with accuracies up to 89%. To the best of my knowledge, this is the first attempt to blend classical AI methods with state-of-the-art machine learning methods for human-robot team collaborative co-navigation. This not only allows for better human-robot team co-navigation, but also has implications for improving other teamwork based human-robot applications such as joint manufacturing and social assistive robotics

Return from exile : mythology and heritage in American born Chinese and its Disney adaptation

Though American Born Chinese has received a significant degree of scholarly study, the prevalence of cultural exile in the text has not received sufficient attention. Said's theorization on exile provides a guide to examining the mindset of Jin, who willfully accepts exile from his Chinese-American heritage because of how he feels neither truly Chinese nor truly American. Only through a visceral encounter with Chinese mythology does he return from exile and embrace that heritage. The Disney adaptation, though significant from a “representation” standpoint, removes that threat of exile, diluting the narrative into a reassuring, palatable formula.Peer reviewe

Quantification of white matter cellularity and damage in preclinical and early symptomatic Alzheimer\u27s disease

Interest in understanding the roles of white matter (WM) inflammation and damage in the pathophysiology of Alzheimer disease (AD) has been growing significantly in recent years. However, in vivo magnetic resonance imaging (MRI) techniques for imaging inflammation are still lacking. An advanced diffusion-based MRI method, neuro-inflammation imaging (NII), has been developed to clinically image and quantify WM inflammation and damage in AD. Here, we employed NII measures in conjunction with cerebrospinal fluid (CSF) biomarker classification (for β-amyloid (Aβ) and neurodegeneration) to evaluate 200 participants in an ongoing study of memory and aging. Elevated NII-derived cellular diffusivity was observed in both preclinical and early symptomatic phases of AD, while disruption of WM integrity, as detected by decreased fractional anisotropy (FA) and increased radial diffusivity (RD), was only observed in the symptomatic phase of AD. This may suggest that WM inflammation occurs earlier than WM damage following abnormal Aβ accumulation in AD. The negative correlation between NII-derived cellular diffusivity and CSF Aβ42 level (a marker of amyloidosis) may indicate that WM inflammation is associated with increasing Aβ burden. NII-derived FA also negatively correlated with CSF t-tau level (a marker of neurodegeneration), suggesting that disruption of WM integrity is associated with increasing neurodegeneration. Our findings demonstrated the capability of NII to simultaneously image and quantify WM cellularity changes and damage in preclinical and early symptomatic AD. NII may serve as a clinically feasible imaging tool to study the individual and composite roles of WM inflammation and damage in AD. Keywords: Inflammation, White matter damage, Diffusion basis spectrum imaging, Neuro-inflammation imaging, Cerebrospinal fluid, Preclinical Alzheimer disease, Early symptomatic Alzheimer disease, Magnetic resonance imagin

The University of Akron Human Powered Vehicle Team

The University of Akron Human Powered Vehicle Team’s 2016 vehicle, Klokan, was designed, manufactured and tested with safety, reliability, performance and ease of use in mind. The vehicle is a fully faired tadpole trike with a lightweight aluminum frame constructed from 6061-T6 tubing having a total weight of 8.9 lbs. To complement the lightweight frame, the fairing is constructed from polycarbonate, PETG and carbon fiber strips which combine into a lightweight, easy to manufacture weather barrier and aerodynamic structure. Klokan was designed to be a safe and efficient mode of everyday transportation which ensures that riders are sufficiently protected by a rollover protection system (RPS) which was designed to meet the ASME HPVC requirements with a minimum safety factor of two. The project scope includes all aspects of design and fabrication to create a vehicle that is easy to manufacture, easy to use, safe, and low cost to facilitate its usability in everyday situations. The team completed research on how to improve the manufacturability, reliability, and performance through analysis of designs, computer based modeling, and physical testing to validate that the bike meets team goals as well as exceeding the requirements set by the ASME Human Powered Vehicle Competition. The frame was designed in a manner that reduces welding through the use of bends and allows for precision fixturing to be manufactured and used to construct multiple frames quickly and efficiently. The fairing’s modular construction reduces the need for specialized tooling while minimizing weight and construction time. The team designed and successfully implemented an innovative rollover warning system which actively monitors the percentage of vehicle load on each tire and warns the driver through audible tone and visual warning light prior to a dangerous rollover becoming imminent

MRE11 liberates cGAS from nucleosome sequestration during tumorigenesis

Oncogene-induced replication stress generates endogenous DNA damage that activates cGAS-STING-mediated signalling and tumour suppression1-3. However, the precise mechanism of cGAS activation by endogenous DNA damage remains enigmatic, particularly given that high-affinity histone acidic patch (AP) binding constitutively inhibits cGAS by sterically hindering its activation by double-stranded DNA (dsDNA)4-10. Here we report that the DNA double-strand break sensor MRE11 suppresses mammary tumorigenesis through a pivotal role in regulating cGAS activation. We demonstrate that binding of the MRE11-RAD50-NBN complex to nucleosome fragments is necessary to displace cGAS from acidic-patch-mediated sequestration, which enables its mobilization and activation by dsDNA. MRE11 is therefore essential for cGAS activation in response to oncogenic stress, cytosolic dsDNA and ionizing radiation. Furthermore, MRE11-dependent cGAS activation promotes ZBP1-RIPK3-MLKL-mediated necroptosis, which is essential to suppress oncogenic proliferation and breast tumorigenesis. Notably, downregulation of ZBP1 in human triple-negative breast cancer is associated with increased genome instability, immune suppression and poor patient prognosis. These findings establish MRE11 as a crucial mediator that links DNA damage and cGAS activation, resulting in tumour suppression through ZBP1-dependent necroptosis

Adolescent Dose and Ratings of an Internet-Based Depression Prevention Program: A Randomized Trial of Primary Care Physician Brief Advice versus a Motivational Interview

Background—Internet-based interventions for education and behavior change have proliferated, but most adolescents may not be sufficiently motivated to engage in Internet-based behavior change interventions. We sought to determine how two different forms of primary care physician engagement, brief advice (BA) versus motivational interview (MI), could enhance participation outcomes in an Internet-based depression prevention intervention. Methods—Eighty-three adolescents at risk for developing major depression were recruited by screening in primary care and randomized to two groups: BA (1–2 minutes) + Internet program versus MI (10–15 minutes) + Internet program. We compared measures of participation and satisfaction for the two groups for a minimum of 12 months after enrollment. Results—Both groups engaged the site actively (MI: 90% versus BA: 78%, p=0.12). MI had significantly higher levels of engagement than BA for measures including total time on site (143.7 minutes versus 100.2 minutes, p=0.03), number of sessions (8.16 versus 6.00, p=0.04), longer duration of session activity on Internet site (46.2 days versus 29.34 days, p=0.04), and with more characters typed into exercises (3532 versus 2004, p=0.01). Adolescents in the MI group reported higher trust in their physician (4.18 versus 3.74, p=0.05) and greater satisfaction with the Internet- based component (7.92 versus 6.66, p=0.01). Conclusions—Primary care engagement, particularly using motivational interviewing, may increase Internet use dose, and some elements enhance and intensify adolescent use of an Internet- based intervention over a one to two month period. Primary care engagement may be a useful method to facilitate adolescent involvement in preventive mental health interventions

Donepezil Impairs Memory in Healthy Older Subjects: Behavioural, EEG and Simultaneous EEG/fMRI Biomarkers

Rising life expectancies coupled with an increasing awareness of age-related cognitive decline have led to the unwarranted use of psychopharmaceuticals, including acetylcholinesterase inhibitors (AChEIs), by significant numbers of healthy older individuals. This trend has developed despite very limited data regarding the effectiveness of such drugs on non-clinical groups and recent work indicates that AChEIs can have negative cognitive effects in healthy populations. For the first time, we use a combination of EEG and simultaneous EEG/fMRI to examine the effects of a commonly prescribed AChEI (donepezil) on cognition in healthy older participants. The short- and long-term impact of donepezil was assessed using two double-blind, placebo-controlled trials. In both cases, we utilised cognitive (paired associates learning (CPAL)) and electrophysiological measures (resting EEG power) that have demonstrated high-sensitivity to age-related cognitive decline. Experiment 1 tested the effects of 5 mg/per day dosage on cognitive and EEG markers at 6-hour, 2-week and 4-week follow-ups. In experiment 2, the same markers were further scrutinised using simultaneous EEG/fMRI after a single 5 mg dose. Experiment 1 found significant negative effects of donepezil on CPAL and resting Alpha and Beta band power. Experiment 2 replicated these results and found additional drug-related increases in the Delta band. EEG/fMRI analyses revealed that these oscillatory differences were associated with activity differences in the left hippocampus (Delta), right frontal-parietal network (Alpha), and default-mode network (Beta). We demonstrate the utility of simple cognitive and EEG measures in evaluating drug responses after acute and chronic donepezil administration. The presentation of previously established markers of age-related cognitive decline indicates that AChEIs can impair cognitive function in healthy older individuals. To our knowledge this is the first study to identify the precise neuroanatomical origins of EEG drug markers using simultaneous EEG/fMRI. The results of this study may be useful for evaluating novel drugs for cognitive enhancement

A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease

A genome-wide survival analysis of 14,406 Alzheimer's disease (AD) cases and 25,849 controls identified eight previously reported AD risk loci and 14 novel loci associated with age at onset. Linkage disequilibrium score regression of 220 cell types implicated the regulation of myeloid gene expression in AD risk. The minor allele of rs1057233 (G), within the previously reported CELF1 AD risk locus, showed association with delayed AD onset and lower expression of SPI1 in monocytes and macrophages. SPI1 encodes PU.1, a transcription factor critical for myeloid cell development and function. AD heritability was enriched within the PU.1 cistrome, implicating a myeloid PU.1 target gene network in AD. Finally, experimentally altered PU.1 levels affected the expression of mouse orthologs of many AD risk genes and the phagocytic activity of mouse microglial cells. Our results suggest that lower SPI1 expression reduces AD risk by regulating myeloid gene expression and cell function