Design of a Robotic Apparatus for Simulated Motion of the Human Hand

Background: The hand is complex, in that any small disturbance to the flexor tendons, extensor tendons, and intrinsic muscles can result in dysfunction of the entire structure. We designed a robotic device to consistently load a native thumb carpometacarpal (CMC) joint in assessing the effects of ligamentous damage on stability of the thumb CMC joint. Methods: The device consisted of a mechanical plate in which to fixate a cadaveric hand, a tendon-suture routing system, a bracket to couple multiple suture lines to a cable to maintain equal force among sutures and tendons, and the finger-thumb force measurement devices. To apply force to the sutures, a cable was run from the suture coupling device to the tendon actuator and from the finger-thumb force measurement devices to the control system. The device was controlled using a Beaglebone Black microcontroller, load cells, rotary encoders, and a liquid crystal display (ie, LCD) touchscreen interface. Results: The design worked as intended in terms of basic communication, signal processing, and control functions. Cyclic loading resulted in web creep of the tissue. Using closed-loop control, the system was able to settle to a desired load. Conclusions: Use of the current device may result in improved understanding of joint movement within the hand, which may help surgeons in treating associated injuries. Future revisions to the device will aim to improve the hardware and software to accelerate the time to converging to the desired force and displacement

Disaster Vulnerability

Vulnerability drives disaster law, yet the literature lacks both an overarching analysis of the different aspects of vulnerability and a nuanced examination of the factors that shape disaster outcomes. Though central to disaster law and policy, vulnerability often lurks in the shadows of a disaster, evident only once the worst is past and the bodies have been counted. The COVID-19 pandemic is a notable exception to this historical pattern: from the beginning of the pandemic, it has been clear that the virus poses different risks to different people, depending on vulnerability variables. This most recent pandemic experience thus provides a useful vantage point for analyzing vulnerability. Drawing on empirical data from the pandemic and experiences from past disasters, this Article identifies and discusses the policy implications of three dimensions of disaster vulnerability: the geography of vulnerability, competing or conflicting vulnerabilities, and political vulnerability. First, it explores the geography of vulnerability, using statistical analysis and geographic information system (GIS) mapping. The Article presents an innovative COVID-19 vulnerability index that identifies the country’s most vulnerable counties and the leading driver of vulnerability for each county. It demonstrates how this index could have informed voter accommodations during the 2020 elections and mask mandates throughout the pandemic. The Article also shows how, going forward, similar modeling could make disaster management more proactive and better able to anticipate needs and prioritize disaster mitigation and response resources. Second, this Article explores competing or conflicting vulnerabilities––situations where policy-makers must prioritize one vulnerable group or one aspect of vulnerability over another. To illustrate this, it considers two other policy challenges: school closures and vaccine distribution. Finally, the Article explores political vulnerability, analyzing how disasters make already-vulnerable groups even more vulnerable to certain harms, including political neglect, stigmatization, disenfranchisement, and displacement. In sum, this Article draws upon the costly lessons of COVID-19 to suggest a more robust framework for policy-makers to assess and respond to vulnerability in future disasters

ICP Etching of SiC

A number of different plasma chemistries, including NF{sub 3}/O{sub 2}, SF{sub 6}/O{sub 2}, SF{sub 6}/Ar, ICl, IBr, Cl{sub 2}/Ar, BCl{sub 3}/Ar and CH{sub 4}/H{sub 2}/Ar, have been investigated for dry etching of 6H and 3C-SiC in a Inductively Coupled Plasma tool. Rates above 2,000 {angstrom} cm{sup {minus}1} are found with fluorine-based chemistries at high ion currents. Surprisingly, Cl{sub 2}-based etching does not provide high rates, even though the potential etch products (SiCi{sub 4} and CCl{sub 4}) are volatile. Photoresist masks have poor selectivity over SiC in F{sub 2}-based plasmas under normal conditions, and ITO or Ni are preferred

A Comparison of Stimulus Set Size on Tact Training for Children with Autism Spectrum Disorder

Previous studies on skill acquisition have taught targets in stimulus sets composed of different numbers of stimuli. Although the rationale for selection of a stimulus set size is not clear, the number of target stimuli trained within a set is a treatment decision for which there is limited empirical support. The current investigation compared the efficiency of tact training in 4 stimulus set sizes, each of which included 12 stimuli grouped into (a) 4 sets of 3 stimuli, (b) 3 sets of 4 stimuli, (c) 2 sets of 6 stimuli, and (d) 1 set of 12 stimuli. Results of all 4 participants with autism spectrum disorder show tact training with larger (i.e., 6 and 12) stimulus set sizes was more efficient than training with smaller (i.e., 3 and 4) stimulus set sizes

Low damage, highly anisotropic dry etching of SiC

A parametric study of the etching characteristics of 6H p{sup +} and n{sup +} SiC and thin film SiC{sub 0.5}N{sub 0.5} in Inductively Coupled Plasma NF{sub 3}/O{sub 2} and NF{sub 3}/Ar discharges has been performed. The etch rates in both chemistries increase monotonically with NF{sub 3} percentage and rf chuck power. The etch rates go through a maximum with increasing ICP source power, which is explained by a trade-off between the increasing ion flux and the decreasing ion energy. The anisotropy of the etched features is also a function of ion flux, ion energy and atomic fluorine neutral concentration. Indium-tin-oxide (ITO) masks display relatively good etch selectivity over SiC (maximum of {approximately} 70:1), while photoresist etches more rapidly than SiC. The surface roughness of SiC is essentially independent of plasma composition for NF3/O2 discharges, while extensive surface degradation occurs for SiCN under high NF{sub 3}:O{sub 2} conditions

An Evaluation of Parent Preference for Prompting Procedures

Parent participation in intervention can enhance intervention efficacy and promote generalization of skills across settings. Thus, parents should be trained to implement behavioral interventions. The purpose of the current investigation was to evaluate parent preference for and acceptability of 3 commonly used prompting procedures. We trained parents of children with disabilities to use 3 empirically validated prompting strategies (i.e., least‐to‐most, most‐to‐least, and a progressive‐prompt delay). Once the parent reached the mastery criteria with each prompting procedure, we evaluated his/her preference for each of the procedures using a concurrent‐chains arrangement. We also measured treatment acceptability of all procedures throughout the study. All participants met the mastery criteria for each of the prompting procedures and showed a preference for least‐to‐most prompting. Results suggest parents\u27 acceptability of procedures prior to training were different than posttraining/post‐child practice. In addition, acceptability rating scores obtained at the end of the investigation corresponded to preference of intervention during the concurrent‐chains arrangement. The results demonstrate the benefits of objective measures for studying preference for behavioral, skill‐acquisition procedures

von Willebrand disease: proposing definitions for future research

Thrombosis and Hemostasi