Braided Composite Technologies for Rotorcraft Structures

A&P Technology has developed a braided material approach for fabricating lightweight, high-strength hybrid gears for aerospace drive systems. The conventional metallic web was replaced with a composite element made from A&P's quasi-isotropic braid. The 0deg, +/-60deg braid architecture was chosen so that inplane stiffness properties and strength would be nearly equal in all directions. The test results from the Phase I Small Spur Gear program demonstrated satisfactory endurance and strength while providing a 20 percent weight savings. (Greater weight savings is anticipated with structural optimization.) The hybrid gears were subjected to a proof-of-concept test of 1 billion cycles in a gearbox at 10,000 revolutions per minute and 490 in-lb torque with no detectable damage to the gears. After this test the maximum torque capability was also tested, and the static strength capability of the gears was 7x the maximum operating condition. Additional proof-of-concept tests are in progress using a higher oil temperature, and a loss-of-oil test is planned. The success of Phase I led to a Phase II program to develop, fabricate, and optimize full-scale gears, specifically Bull Gears. The design of these Bull Gears will be refined using topology optimization, and the full-scale Bull Gears will be tested in a full-scale gear rig. The testing will quantify benefits of weight savings, as well as noise and vibration reduction. The expectation is that vibration and noise will be reduced through the introduction of composite material in the vibration transmission path between the contacting gear teeth and the shaft-and-bearing system

Static Torsion Testing and Modeling of a Variable Thickness Hybrid Composite Bull Gear

Torsional strength of a variable thickness hybrid gear web was measured by performing static testing on the part in a large torsion test frame. The outer rim of the hybrid gear web was fixed to the bottom of the test frame and loading was applied to the web through a shaft. The test setup included the installation of digital image correlation (DIC) systems to obtain deformation and strain measurements from the surfaces of the hybrid gear web and the mechanical test equipment to ensure reliability of the test. The results indicated that the variable thickness hybrid gear web achieved approximately twice the torsional strength compared to that of previous hybrid gear designs. The DIC analysis showed significantly more straining of the loading shaft than the actual test article. Additionally, the results demonstrated the importance and affect that the metallic, lobed interlock features had on the principal strain and out-of-plane displacement fields. The analysis revealed that the fixed outer rim was in fact rotating and a rigid body motion compensation (RBMC) function was computed to determine the actual rotation of the hub and composite web relative to the outer rim. Modeling simulations were performed for the variable thickness hybrid gear web and correlated well with the RBMC rotational deformation seen in the DIC analysis. In addition to benchmarking the load capacity of the hybrid gear web, measuring its strength is useful information to define the parameters needed for dynamic, endurance, and other testing of the part

Discrimination in Medical Settings and Attitudes toward Complementary and Alternative Medicine: The Role of Distrust in Conventional Providers

This study examines the relationship between racial/ethnic discrimination in medical settings, distrust in conventional medicine, and attitudes toward complementary and alternative medicine (CAM) among a racially/ethnically diverse sample. We also investigate how this relationship differs by nativity. Data are from a 2008 statewide stratified sample of publicly insured adults in Minnesota (N=2,194). Discrimination was measured as self-reported unfair treatment in medical settings due to race, ethnicity, and/or nationality. Outcomes are trust in conventional providers/medicine and attitudes toward CAM modalities. Discrimination in medical settings was positively associated with 1) distrust in conventional providers and 2) favorable attitudes toward CAM. Foreign-born status was associated with more distrust in conventional providers/medicine and more positive attitudes toward CAM. Our findings show that for publicly insured, and especially minority and foreign-born individuals, CAM may represent a response to disenfranchisement in conventional medical settings and resulting distrust

New enantiornithine diversity in the Hell Creek Formation and the functional morphology of the avisaurid tarsometatarsus

Enantiornithines were the most diverse group of birds during the Cretaceous, comprising over half of all known species from this period. The fossil record and subsequently our knowledge of this clade is heavily skewed by the wealth of material from Lower Cretaceous deposits in China. In contrast, specimens from Upper Cretaceous deposits are rare and typically fragmentary, yet critical for understanding the extinction of this clade across the K-Pg boundary. The most complete North American Late Cretaceous enantiornithine is Mirarce eatoni, a member of the diverse clade Avisauridae. Except for Mirarce, avisaurids are known only from isolated hindlimb elements from North and South America. Here we describe three new enantiornithines from the Maastrichtian Hell Creek Formation, two of which represent new avisaurid taxa. These materials represent a substantial increase in the known diversity of Enantiornithes in the latest Cretaceous. Re-examination of material referred to Avisauridae through phylogenetic analysis provides strong support for a more exclusive Avisauridae consisting of six taxa. Exploration of the functional morphology of the avisaurid tarsometatarsus indicates potential strong constriction and raptorial attributes. The lower aspect ratio of the tarsometatarsus facilitates a more biomechanically efficient lever system which in extant birds of prey equates to lifting proportionally heavier prey items. In addition, the proportional size and distal position of the m. tibialis cranialis tubercle of the tarsometatarsus is similar to the morphology seen in extant birds of prey. Together with the deeply-grooved metatarsal trochlea facilitating robust and likely powerful pedal digits, morphologies of the hindlimb suggest avisaurids as Late Cretaceous birds of prey

Intra-oral anatomy training device

Disclosed herein are typodont models and dental mannequins that provide a highly accurate representation of the human or non-human animal oral anatomy. The model embodiments disclosed herein provide life-like materials and various features of the oral cavity not found in typical typodont models. Additionally, the typodont models disclosed herein simulate many challenging conditions that arise in dental procedures when performed on live subjects such as, for example, clouding of instruments including mirrors used to view the interior portion of the oral cavity, oral fluid interfering with the work area, and other real-life interferences and complications. The ability to mimic the oral cavity with as much accuracy as possible is beneficial to the dental field for both practitioners as well as patients

Diagnostic Ultrasound as a Reliable Tool to Measure Multifidus Thickness

Introduction: Lower back pain (LBP) is a recurrent issue in the general population, though it is generally seen 2-3 times more frequently in those who undergo transfemoral amputations, being considered worse than phantom limb or residual pain. It is suggested that LBP is more common in those who have a transfemoral amputation than those who have a transtibial amputation. Research thus far has seemed to focus on identifying links between unilateral amputation and LBP rather than bilateral. The multifidus muscle is the most important dynamic stabilizer of the lumbar spine, accounting for two- thirds of lower lumbar segmental stability. A contributor to this pain may be multifidus muscle atrophy and an increase in intramuscular fat deposits and fibrous tissue infiltration, resulting in increased total muscle thickness with decreased multifidus activation and function, reducing dynamic stability capabilities and contributing to LBP. However, a lack of research in this population has led to an inconclusive explanation of the underlying mechanisms that may cause LBP. Typically, magnetic resonance imaging (MRI) is used as the gold standard to assess the thickness of the multifidus muscle, but it is costly and not as accessible to clinicians and patients. Ultrasound imaging (USI) can instead be used to assess multifidus thickness and it is reliable in the general population. Although extensive research has been performed in the general population, the reliability of diagnostic ultrasound imaging for multifidus thickness in populations who have undergone transfemoral amputations has not been studied. The purpose of this study was to evaluate intra-rater reliability of multifidus thickness measurements utilizing USI. Establishing reliability of USI in people with lower extremity amputations will allow us to confidently investigate any association between multifidus thickness and LBP. Methods: Eleven participants who had undergone a unilateral transfemoral amputation at least one year prior to testing were recruited in the Las Vegas area for this intra-rater reliability study. USI Procedure: Each participant was scheduled for two separate sessions, at least two days apart, but no more than 10. One examiner at the University of Nevada, Las Vegas, independently recorded the ultrasound images and measurements of the multifidus muscle. Results: The reliability was excellent (ICC: .985 confidence interval was within an acceptable range of .955 to .995. The SEM ranged from .152 cm to .157 cm, and the MDC ranged from .421 cm to .435 cm. Conclusion: This study showed that the intra-rater reliability of the measurements of the multifidus muscle thickness using diagnostic ultrasound imaging between two sessionsshowed excellent reliability. These results suggest that diagnostic ultrasound imaging is a reliable tool for measuring multifidus thickness in those with unilateral transfemoral amputations. Utilizing USI as a tool to measure multifidus muscle thickness will allow for further investigation regarding the association of multifidus muscle thickness and lower back pain in this patient population

Chromosome-Level Genome Assembly of Chinese Sucker (Myxocyprinus asiaticus) Reveals Strongly Conserved Synteny Following a Catostomid-Specific Whole-Genome Duplication

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Characterizing Australia's east coast cyclones (1950–2019)

East coast cyclones (ECCs) provide an essential reprieve from dry periods across eastern Australia. They also deliver flood‐producing rains with significant economic, social and environmental impacts. Assessing and comparing the influence of different types of cyclones is hindered by an incomplete understanding of ECC typology, given their widely variable spatial and temporal characteristics. This study employs a track‐clustering method (probabilistic curve‐aligned regression model) to identify key cyclonic pathways for ECCs from 1950 to 2019. Six spatially independent clusters were successfully distinguished and further sub‐classified (coastal, continental and tropical) based on their genesis location. The seasonality and long‐term variability, intensity (maximum Laplacian value ± two days) and event‐based rainfall were then evaluated for each cluster to quantify the impact of these storms on Australia. The highest quantity of land‐based rainfall per event is associated with the tropical cluster (Cluster 6), whereas widespread rainfall was also found to occur in the two continental lows (Cluster 4 and 5). Cyclone tracks orientated close to the coast (clusters 1, 2 and 3) were determined to be the least impactful in terms of rainfall and intensity, despite being the most common cyclone type. In terms of interannual variability, sea surface temperature anomalies suggest an increased cyclone frequency for clusters 1 (austral winter) and 4 (austral spring) during a central Pacific El Niño. Further, cyclone incidence during IOD‐negative conditions was more pronounced in winter for clusters 1, 2, 3 – and clusters 4 and 5 in spring. All cyclones also predominantly occurred in SAM‐positive conditions. However, winter ECCs for clusters 1 and 3 had a higher frequency in SAM‐negative. This new typology of ECCs via spatial clustering provides crucial insights into the systems that produce extreme rainfall across eastern Australia and should be used to inform future hazard management of cyclone events. This article is protected by copyright. All rights reserved

CRISPR interference interrogation of COPD GWAS genes reveals the functional significance of desmoplakin in iPSC-derived alveolar epithelial cells

Genome-wide association studies (GWAS) have identified dozens of loci associated with chronic obstructive pulmonary disease (COPD) susceptibility; however, the function of associated genes in the cell type(s) affected in disease remains poorly understood, partly due to a lack of cell models that recapitulate human alveolar biology. Here, we apply CRISPR interference to interrogate the function of nine genes implicated in COPD by GWAS in induced pluripotent stem cell–derived type 2 alveolar epithelial cells (iAT2s). We find that multiple genes implicated by GWAS affect iAT2 function, including differentiation potential, maturation, and/or proliferation. Detailed characterization of the GWAS gene DSP demonstrates that it regulates iAT2 cell-cell junctions, proliferation, mitochondrial function, and response to cigarette smoke–induced injury. Our approach thus elucidates the biological function, as well as disease-relevant consequences of dysfunction, of genes implicated in COPD by GWAS in type 2 alveolar epithelial cells.This work was supported by a CJ Martin Early Career Fellowship from the Australian National Health and Medical Research Council awarded to R.B.W.; NIH grant F30HL147426 awarded to K.M.A.; NIH grants U01TR001810, R01DK101501, and R01DK117940 awarded to A.A.W.; NIH grants R01HL135142, R01HL137927, and R01HL147148 awarded to M.H.C.; and NIH grants R01HL127200 and R01HL148667 awarded to X.Z