Toward Fine Contact Interactions: Learning to Control Normal Contact Force with Limited Information

Dexterous manipulation of objects through fine control of physical contacts is essential for many important tasks of daily living. A fundamental ability underlying fine contact control is compliant control, \textit{i.e.}, controlling the contact forces while moving. For robots, the most widely explored approaches heavily depend on models of manipulated objects and expensive sensors to gather contact location and force information needed for real-time control. The models are difficult to obtain, and the sensors are costly, hindering personal robots' adoption in our homes and businesses. This study performs model-free reinforcement learning of a normal contact force controller on a robotic manipulation system built with a low-cost, information-poor tactile sensor. Despite the limited sensing capability, our force controller can be combined with a motion controller to enable fine contact interactions during object manipulation. Promising results are demonstrated in non-prehensile, dexterous manipulation experiments

Quantitative analysis of chromatin compaction in living cells using FLIM-FRET

FRET analysis of cell lines expressing fluorescently tagged histones on separate nucleosomes demonstrates that variations in chromosome compaction occur during mitosis

Expanding Rural Opioid Addictions Treatment: An Inter-institutional, Inter-professional Telehealth Case Study Simulation

Purpose: To determine if inter-institutional collaboration, using telehealth technology, inter-professional education techniques, and case study methodology is a feasible way to teach health professions students how to appropriately address opioid addictions, especially in rural populations with limited health care access. Study subjects: Ten health professions students from four Virginia universities participated. Professions represented included medicine, nursing, physical therapy, social work, nutrition, and psychology at the graduate and undergraduate levels. Methods: Inter-professional faculty from four Virginia universities developed an opioid addiction simulation case study using a standardized patient. Students from different regions engaged in a facilitated patient interview and care planning via secure virtual meeting platform. Faculty observation and feedback, student feedback, and inter-professional education assessments were used to assess this pilot study. Findings: Inter-institutional faculty collaboration and telehealth technology was successfully employed to convene multiple health professions students from different sites; simulation case study methodology using a standardized patient was effective and compelling; students effectively utilized interprofessional competencies and skills to develop a comprehensive and holistic care plan for opioid addiction treatment. Conclusions: Telehealth technology, inter-professional education, and simulation case study methodology can be successfully used to teach health professions students how to collaborate to address the opioid crisis, especially in resource-limited rural areas. Implications: Many resources are necessary to successfully treat opioid addictions. By using telehealth technology combined with inter-professional concepts and skills, resources can be shared between institutions and professions to successfully treat patients with opioid addictions in resource-limited areas

Moisture adsorption and desorption properties of colloidal silicon dioxide and its impact on layer adhesion of a bilayer tablet formulation

A bilayer tablet formulation approach was used to develop a fixed dose combination tablet formulation of drugs Y & Z. The weight of Layer I containing Drug Y and the weight of Layer II A or II B containing Drug Z were 250 mg and 1280 mg, respectively. While Layer I was manufactured using dry granulation, Layer II A and II B were manufactured using a moisture activated dry granulation (MADG) process. Layer II A and Layer II B contained 3% w/w colloidal silicon dioxide with the surface area of 300 m2/g (Aeroperl® 300) and 200 m2/g (Aerosil® 200), respectively, for moisture scavenging, and otherwise common excipients. Both grades of silicon dioxide were amorphous. When exposed to an open relative humidity of 40°C/75% for 72 hours, the bilayer tablet consisting of Layers I/Layer II A (containing Aeroperl® 300) showed a clear layer separation while the tablet consisting of Layers I/Layer II B (containing Aerosil® 200) did not. If the individual layer is exposed to a similar condition, the projected change in the moisture content for Layer I, Layer II A, and Layer II B, could be 63% w/w, 107% w/w, and 109% w/w, respectively. Thus, the difference in moisture adsorption between Layer I/ Layer II A (containing Aeroperl® 300) than Layer I/Layer II B (containing Aerosil® 200) was similar. The comparison of the moisture adsorption-desorption isotherms for Aeroperl® 300 and Aerosil® 200 suggested that Aeroperl® 300 can adsorb relatively large amounts of moisture at any humidity level due to its greater surface area but it does not retain moisture when the humidity decreases. In contrast, Aerosil 200 adsorb relatively smaller amounts of moisture but it retains moisture due to its larger pore sizes. It is hypothesized that the moisture not retained by Aeroperl® 300 could be available for interaction with other Layer I excipients, such as, microcrystalline cellulose and crospovidone. Such interaction can generate significant shear stress at the layer interface triggering the delamination

Faculty Convocation

Program listing performers and works performe

Convocation

Program listing performers and works performe

Nuclear accessibility of beta-actin mRNA is measured by 3D single-molecule real-time tracking

Imaging single proteins or RNAs allows direct visualization of the inner workings of the cell. Typically, three-dimensional (3D) images are acquired by sequentially capturing a series of 2D sections. The time required to step through the sample often impedes imaging of large numbers of rapidly moving molecules. Here we applied multifocus microscopy (MFM) to instantaneously capture 3D single-molecule real-time images in live cells, visualizing cell nuclei at 10 volumes per second. We developed image analysis techniques to analyze messenger RNA (mRNA) diffusion in the entire volume of the nucleus. Combining MFM with precise registration between fluorescently labeled mRNA, nuclear pore complexes, and chromatin, we obtained globally optimal image alignment within 80-nm precision using transformation models. We show that beta-actin mRNAs freely access the entire nucleus and fewer than 60% of mRNAs are more than 0.5 microm away from a nuclear pore, and we do so for the first time accounting for spatial inhomogeneity of nuclear organization

Elucidation of the ebola virus VP24 cellular interactome and disruption of virus biology through targeted inhibition of host-cell protein function

Viral pathogenesis in the infected cell is a balance between antiviral responses and subversion of host-cell processes. Many viral proteins specifically interact with host-cell proteins to promote virus biology. Understanding these interactions can lead to knowledge gains about infection and provide potential targets for antiviral therapy. One such virus is Ebola, which has profound consequences for human health and causes viral hemorrhagic fever where case fatality rates can approach 90%. The Ebola virus VP24 protein plays a critical role in the evasion of the host immune response and is likely to interact with multiple cellular proteins. To map these interactions and better understand the potential functions of VP24, label-free quantitative proteomics was used to identify cellular proteins that had a high probability of forming the VP24 cellular interactome. Several known interactions were confirmed, thus placing confidence in the technique, but new interactions were also discovered including one with ATP1A1, which is involved in osmoregulation and cell signaling. Disrupting the activity of ATP1A1 in Ebola-virus-infected cells with a small molecule inhibitor resulted in a decrease in progeny virus, thus illustrating how quantitative proteomics can be used to identify potential therapeutic targets

Sundown Syndrome in Persons with Dementia: An Update

"Sundowning" in demented individuals, as distinct clinical phenomena, is still open to debate in terms of clear definition, etiology, operationalized parameters, validity of clinical construct, and interventions. In general, sundown syndrome is characterized by the emergence or increment of neuropsychiatric symptoms such as agitation, confusion, anxiety, and aggressiveness in late afternoon, in the evening, or at night. Sundowning is highly prevalent among individuals with dementia. It is thought to be associated with impaired circadian rhythmicity, environmental and social factors, and impaired cognition. Neurophysiologically, it appears to be mediated by degeneration of the suprachiasmatic nucleus of the hypothalamus and decreased production of melatonin. A variety of treatment options have been found to be helpful to ameliorate the neuropsychiatric symptoms associated with this phenomenon: bright light therapy, melatonin, acetylcholinesterase inhibitors, N-methyl-d-aspartate receptor antagonists, antipsychotics, and behavioral modifications. To decrease the morbidity from this specific condition, improve patient's well being, lessen caregiver burden, and delay institutionalization, further attention needs to be given to development of clinically operational definition of sundown syndrome and investigations on etiology, risk factors, and effective treatment options