Joshua Holt - Academia.edu (original) (raw)

Papers by Joshua Holt

The Iowa Orthopaedic Journal, 2021

The ligamentum teres (LT) is believed to have a number of functions, including a role in hip stab... more The ligamentum teres (LT) is believed to have a number of functions, including a role in hip stability, nociception, proprioception, vascular supply to the femoral head, and synovial fluid circulation. The LT is often excised in the process of performing a medial open reduction (MOR) of the hip. We sought to conduct a retrospective review of hips undergoing a MOR for dislocated infantile developmental dysplasia of the hip (DDH) to compare clinical and radiographic outcomes for patients with and without LT reconstruction. We performed a retrospective review of 38 hips treated with MOR with or without LT reconstruction with minimum two-year follow-up. Radiographic outcomes were determined using the Severin score. Information regarding avascular necrosis (AVN), concomitant surgical procedures, repeat dislocation, subsequent surgery, limp, pain, and range of motion symmetry was recorded. Eighteen hips that underwent MOR with LT reconstruction were compared to 20 hips that underwent MOR ...

ABSTRACT The necessity for separation of single-wall carbon nanotube (SWCNT) populations to achie... more ABSTRACT The necessity for separation of single-wall carbon nanotube (SWCNT) populations to achieve desired properties presents a major technical barrier for the development of SWCNT-based applications, and has been the focus of significant academic and industrial research. Recent advances include the separation of SWCNT populations by diameter through buoyancy differences. Here we report on the optical spectroscopic properties of large diameter SWCNTs synthesized by laser ablation and electric arc methods and then separated by centrifugation to produced isolated bands of empty and water-filled nanotubes. This separation is consistent across multiple nanotube populations dispersed from different source material. Optical absorption, near-infrared fluorescence, and Raman spectroscopic measurements of the resulting empty and filled fractions reveal that water filling leads to systematic changes in the optical properties. Specifically, the peak locations in absorbance and fluorescence display red-shifts with the presence of water in the nanotube cavity and a hardening of the Raman radial breathing modes. The presence of water in the SWCNT interior is found to facilitate the subsequent separation into sub-populations of metallic and semiconducting SWCNTs.

Spine

February 2020, before physicians and surgeons were support aggressive treatment for progressive E... more February 2020, before physicians and surgeons were support aggressive treatment for progressive EOS in chilI n all required to alter their practices in response to COVID, pediatric spine surgeons were forced to change their practice due to the FDA recall of NuVasive MAGEC Model X Rods (MCGR) (https://www.nuvasive.com/wpcontent/uploads/2020/02/Field-Safety-Notice-MAGEC-X. pdf). These rods were widely used for patients with earlyonset scoliosis with large curvatures, and have been implanted in thousands of patients in the United States and around the world. Without the MCGR option, surgeons were forced to either wait for the recall problem to be solved or resort to traditional growing rods or other alternatives. Current opinion supports only growth-friendly (GF) alternatives for skeletally immature EOS patients, regardless of etiology or age. Justifying combination of the old scoliosis classifications of infantile and juvenile onset into a new EOS classification (scoliosis onset before 10 years of age), ElHawary and Akbarnia state ‘‘. . .the treatment principles for children between the ages of five and ten years more closely resemble those used for children under the age of five years (growth friendly surgery) than they do for children over the age of ten years (fusion surgery).’’ We argue, however, that older idiopathic EOS (IEOS) patients, perhaps those 8 years of age or older, are not necessarily best served by the same treatments as younger children. Instead, to quote El-Hawary and Akbarnia a second time, in such a heterogeneouspopulation ‘‘treatment should be individualized based on the available evidence and the surgeon’s experience.’’ The long-term prognosis of untreated IEOS is one of progressive deformity and potentially life-threatening pulmonary compromise. Hence there is solid evidence to

Section on Orthopaedics Program

Introduction: Parents often access online resources to educate themselves when a child is diagnos... more Introduction: Parents often access online resources to educate themselves when a child is diagnosed with developmental dysplasia of the hip (DDH). In order to be fully understood by the average adult American, online health information must be written at an elementary school reading level. It was hypothesized that current available online resources regarding DDH would score poorly on objective measures of readability (syntax reading grade-level), understandability (ability to process key messages), and actionability (providing actions the reader may take). It was additionally hypothesized that the readability, understandability, and actionability would not correlate with search rank. Methods: Patient education materials were identified utilizing two independent online searches of the term “DDH” utilizing a commonly used search ending. From the top 50 search results, websites were included if directed at educating patients/parents regarding DDH. News articles, non-text material (video), research and journal articles, industry websites, and articles not related to DDH were excluded. The readability of included resources was quantified using the Flesch-Kincaid Grade Level Index. The Patient Education Materials Assessment Tool (PEMAT) was used to assess understandability and actionability using a 0-100% scale for both measures of interest. Spearman’s rho was used to examine the association between a website’s average search rank (from first to last) and its readability, understandability, and actionability. Statistical significance was defined as p<0.05. Results: From 60 unique websites, 37 websites met inclusion criteria. The mean reading grade level (Flesch-Kincaid) was 12.54±2.72, with no websites having a reading level ≤ 6. No readability statistics were statistically associated with search rank (lowest three p-values: 0.80, 0.83, 0.85). Mean understandability and actionability scores were 55.19± 13.96 and 16.58±21.69, respectively. Among understandability criteria, only 27.03% (10/37) resources made their purpose evident and only 10.81% (4/37) included summaries. Among actionability categories, 40.54% (15/37) of websites identified ≥1 action for readers, but only 5.41% (2/37) studies broke down actions into explicit, easy to understand steps. The order of search results was not associated with understandability (rho: -0.21, p=0.22) or actionability (rho: 0.0878, p=0.61). Conclusion: Overall, the online DDH patient/parent educational materials that were assessed scored poorly with respect to readability, understandability, and actionability. Currently, search rank for DDH materials is not associated with the readability, understandability, or actionability of these resources. In the era of shared decision-making and readily available information, patients often turn to the internet for additional insight into the diagnosis, management, and outcomes of DDH. Therefore, future efforts should be made by medical professionals to improve the readability, understandability, and actionability of online resources in order to optimize parental understanding and facilitate informed decision-making.

Journal of Pediatric Orthopaedics

Spinal muscular atrophy (SMA) is a progressive neuromuscular disease commonly including progressi... more Spinal muscular atrophy (SMA) is a progressive neuromuscular disease commonly including progressive scoliosis resulting in severe deformity and negatively affecting pulmonary function. Surgical correction and stabilization of this progressive deformity is generally recommended; however, the timing and method of surgical fixation remains controversial. Retrospective review of clinical, radiographic, and pulmonary function data from 16 children with SMA and surgically treated scoliosis between 1985 and 2013. Radiographic data included direct measures of major curve, coronal balance, pelvic obliquity, T1-T12 height, T1-S1 height, and T1-rod length. Estimations of rib collapse, thoracic cavity shape, and space-available-for-lung (T6:T12, width ratio; T6:T10, rib-vertebral-angle difference ratios; and lung height) were determined. Eleven patients were able to complete pulmonary function testing. Results were compared with published outcomes for growing rod constructs. Posterior spinal fusion was performed at an average age of 9.8±3.6 years. The mean age at most recent follow-up was 19.4 years (range, 10 to 37 y), with a mean follow-up of 10.1 years (range, 3.1 to 26 y). Radiographic measurements improved from preoperative to latest follow-up as follows: major curve, 78±20 degrees to 27±24 degrees; coronal balance, 4.1±4.0 cm to 1.9±2.2 cm; pelvic obliquity (median), 23 to 5 degrees; T1-T12 height, 19±3 cm to 22±3 cm; T1-S1 height, 31±7 cm to 36±6 cm; T1-rod length, 0.8±1.1 cm (postop) to 2.8±1.6 cm (final); and space-available-for-lung ratio, 0.88±0.26 to 0.95±0.25. Rib collapse continued throughout the follow-up period in all but 1 patient. Pulmonary function testing demonstrated a decrease in rate of decline in forced vital capacity and forced expiratory volume when comparing preoperative with postoperative rates. Mean length of stay was 7.8±4.4 days. Complications included reintubation for low tidal volumes (n=1), pneumonia (n=1), superficial wound breakdown (n=1), and superficial infection (n=1). Definitive posterior spinal fusion for treatment of scoliosis associated with SMA is effective at controlling curve progression and pelvic obliquity without negatively impacting the space-available-for-lung ratio, trunk height, or pulmonary function at 10 years follow-up. Therapeutic Level IV.

Semiconductor Science and Technology

The recent surge of research on resistive random access memory (ReRAM) devices has resulted in a ... more The recent surge of research on resistive random access memory (ReRAM) devices has resulted in a wealth of different materials and fabrication approaches. In this work, we describe the performance implications of utilizing a reactive ion etch (RIE) based process to fabricate HfO2 based ReRAM devices, versus a more unconventional shadow mask fabrication approach. The work is the result of an effort to increase device yield and reduce individual device size. Our results show that choice of RIE etch gas (SF6 versus CF4) is critical for defining the post-etch device profile (cross-section), and for tuning the removal of metal layers used as bottom electrodes in the ReRAM device stack. We have shown that etch conditions leading to a tapered profile for the device stack cause poor electrical performance, likely due to metal re-deposition during etching, and damage to the switching layer. These devices exhibit nonlinear I–V during the low resistive state, but this could be improved to linear behavior once a near-vertical etch profile was achieved. Device stacks with vertical etch profiles also showed an increase in forming voltage, reduced switching variability and increased endurance.

Applied Physics Letters

Mutli-level switching in resistive memory devices enables a wide range of computational paradigms... more Mutli-level switching in resistive memory devices enables a wide range of computational paradigms, including neuromorphic and cognitive computing. To this end, we have developed a bilayer tantalum oxide based resistive random access memory (RRAM) device using Hf as the oxygen exchange layer (OEL). Multiple, discrete resistance levels were achieved by modulating RESET pulse width and height, ranging from 2 kΩ to 142 kΩ. For a fixed pulse height, OFF state resistance was found to increase gradually with the increase of pulse width whereas for fixed pulse width, increases in pulse height resulted in drastic changes in resistance. Resistive switching in these devices transitioned from Schottky emission in the OFF state to tunneling based conduction in the ON state, based on I-V curve fitting and temperature dependent current measurements. These devices also demonstrated endurance of more than 10 8 cycles with satisfactory Roff/Ron ratio and retention greater than 10 4 s.

2015 IEEE International Integrated Reliability Workshop (IIRW), 2015

Resistive memory (RRAM) is an emerging memory technology, expected to have inherent resistance to... more Resistive memory (RRAM) is an emerging memory technology, expected to have inherent resistance to radiation damage. We present an initial study characterizing the effects of several types of radiation on a set of tantalum oxide-based RRAM devices. Gamma radiation (64.7 Mrad(Si)) was found to have no significant impact on switching properties. Likewise, ionic radiation (H, N, Ar+) up to 1015 ions/cm2 did not have any significant effect. This resistance to radiation, combined with high endurance and data retention, make RRAM an excellent candidate for use in harsh environments.

This thesis examines the independent alternative music scene in the city of Hamilton, Ontario, al... more This thesis examines the independent alternative music scene in the city of Hamilton, Ontario, also known, with reference to its industrial heritage, as "Steeltown." Drawing on the growing literature on the relationship between place and popular music, on my own experience as a local musician, direct observation of performances and of venues and other sites of interaction, as well as ethnographic interviews with scene participants, I focus on the role of space, genre and performance within the scene, and their contribution to a sense of local identity. In particular, I argue that the live performance event is essential to the success of the local music scene, as it represents an immediate process, a connection between performers and audience, one which is temporally rooted in the present. My research suggests that the Hamilton alternative music scene has become postmodern, embracing forms of "indie" music that lie outside of mainstream taste, and particularly those which engage in the exploration and deconstruction of pre-existing genres. Eventually, however, the creative successes of an "indiescene" permeate mass culture and often become co-opted into the popular music mainstream, a process which, in turn, promotes new experimentation and innovation at the local level.

As online learning enrollments rapidly increase, it is vital to explore effective course designs ... more As online learning enrollments rapidly increase, it is vital to explore effective course designs that deepen students' learning experiences. This multiple-case study explores four online courses at Brigham Young University-Idaho that include learning activities where students learned through Teach One Another activities. Teach One Another is similar to Reciprocal Peer Learning where students simultaneously learn and contribute to their peers' learning. Findings across the cases of this study show that Teach One Another activities in online courses encourage students to be accountable and motivated to complete individual course work as well as group assignments. As students learn to build trusting learning relationships, group activities may deepen students' learning experiences. This study discusses implications for online course designers, developers, and administrators who are interested in giving students opportunities to deepen their learning of the content and develop life skills such as accountability, responsibility, and trust.

The Journal of Arthroplasty, 2015

We introduced a multimodal, multidisciplinary approach to perioperative blood management aimed at... more We introduced a multimodal, multidisciplinary approach to perioperative blood management aimed at reducing blood transfusions in primary knee (TKA) and hip (THA) arthroplasty. The protocol included (1) preoperative hemoglobin optimization through a multidisciplinary approach, (2) minimization of perioperative blood loss, and (3) adherence to evidence-based transfusion guidelines. Evaluation of 1010 consecutive patients undergoing primary TKA (488) or THA (522) was performed. A significant reduction in the overall transfusion rate (1.4% vs 17.9%, P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.0001) resulted after algorithm introduction, when compared with the 1814 previous patients. Zero (0%) TKA and 4 (0.8%) THA patients adherent to protocol, and 4/488 (0.8%) TKA and 10/522 (1.9%) THA patients overall received transfusions. Adoption of a multimodal blood management algorithm can significantly reduce blood transfusions in primary joint arthroplasty.

Journal of burn care & research : official publication of the American Burn Association

Inhaled heparin/N-acetylcystine (AHA) has been reported to decrease mortality in children with in... more Inhaled heparin/N-acetylcystine (AHA) has been reported to decrease mortality in children with inhalation injury. The use of AHA therapy in adult burn patients with inhalation injury has not been evaluated. We hypothesized that patients who received AHA therapy in the management of inhalation injury would have better pulmonary mechanics and better clinical outcomes than patients who did not. This study is a retrospective chart review of pulmonary mechanics and clinical outcomes in all inpatients identified in the institutional ABA/TRACS database as having sustained inhalation injury from 1999 to 2005. Patients were not assigned to a treatment group. One hundred and fifty patients with inhalation injury were identified. Sixty-two patients were treated with AHA during the first 72 hours of admission. Treatment occurred mostly in patients admitted after 2002, with only 18 patients receiving AHA from 1999 through 2002. Treated and untreated patients did not differ in age or TBSA burn in...

KEYNOTE ADDRESS. Self-Propagating High-Temperature Synthesis: Twenty Years of Search and Findings... more KEYNOTE ADDRESS. Self-Propagating High-Temperature Synthesis: Twenty Years of Search and Findings (A. Merzhanov). SOLID-STATE COMBUSTION SYNTHESIS. Recent Progress in Combustion Synthesis of High-Performance Materials in Japan (M. Koizumi & Y. Miyamoto). Modeling and Numerical Computation of a Nonsteady SHS Process (A. Bayliss & B. Matkowsky). New Models of Quasiperiodic Burning in Combustion Synthesis (S. Margolis, et al.). Modeling of SHS

Molecular Genetics and Metabolism, 2010

The Journal of Hand Surgery, 2013

... Although the shiny surface suggested metallic properties, conductivity of the new polyacetyle... more ... Although the shiny surface suggested metallic properties, conductivity of the new polyacetylene was not ... The field of conducting polymers was officially born in 1977 when Heeger, MacDiarmid ... The ID ideal model, however, is spoiled by interchain interactions with neighboring ...

How Students Experience Teach One Another Activities in Online Courses at Brigham Young Universit... more How Students Experience Teach One Another Activities in Online Courses at Brigham Young University-Idaho

Developmental dysplasia of the hip (DDH) in the newborn describes a wide spectrum of pathologic d... more Developmental dysplasia of the hip (DDH) in the newborn describes a wide spectrum of pathologic disorders of the hip, ranging from subtle dysplasia of the acetabulum to irreducible hip dislocation. At all ages of treatment, the primary goal is to obtain a concentric reduction of the femoral head within the acetabulum while minimizing the risk for avascular necrosis or other complications. When recognized in the first 6 months of life, DDH is typically successfully treated with simple outpatient based harness therapy (Pavlik) and routinely results in excellent outcomes. After 6 months of age, closed reduction, open reduction, and femoral and pelvic osteotomies are more often required as treatment modalities. Each treatment decision should be considered thoughtfully in each unique patient encounter, with the overriding goal of obtaining a concentrically reduced hip joint while minimizing complications always at the forefront.

Background The ligamentum teres (LT) is believed to have a number of functions, including a role ... more Background The ligamentum teres (LT) is believed to have a number of functions, including a role in hip stability, nociception, proprioception, vascular supply to the femoral head, and synovial fluid circulation. The LT is often excised in the process of performing a medial open reduction (MOR) of the hip. We sought to conduct a retrospective review of hips undergoing a MOR for dislocated infantile developmental dysplasia of the hip (DDH) to compare clinical and radiographic outcomes for patients with and without LT reconstruction. Methods We performed a retrospective review of 38 hips treated with MOR with or without LT reconstruction with minimum two-year follow-up. Radiographic outcomes were determined using the Severin score. Information regarding avascular necrosis (AVN), concomitant surgical procedures, repeat dislocation, subsequent surgery, limp, pain, and range of motion symmetry was recorded. Results Eighteen hips that underwent MOR with LT reconstruction were compared to ...

AIAA Scitech 2019 Forum

The purpose of this project is to provide a technology demonstration of the aerial delivery of ca... more The purpose of this project is to provide a technology demonstration of the aerial delivery of cargo-carrying UAVs. This capability will allow small, high-value payloads to be delivered over the same long distances as the traditional airlift and Joint Precision Airdrop System (JPADS) combination with previously unattainable accuracy. A team of undergraduate students at the United States Military Academy accomplished this goal by designing, building, testing, and demonstrating a scale model of a UAV aerial delivery system. The customer for this product is the Aerial Delivery Directorate at Natick Soldier Research Development and Engineering Center, which will expand the scale model prototype into an operational system. The system leverages the existing technologies of JPADS and GPS-enabled multi-rotors and combines them to create the airdrop method of the future. The operational system will have the capability to deliver a 5-15 lb. payload to within 5 meters of the target location. This will enable effective resupply of individuals or troops in contact, who could pick up an airdrop without having to leave cover.