Developing a Robust Balance for Wingsuit Aerodynamic Research

Research on wingsuit aerodynamics requires specialized wind tunnel equipment. There is the potential for the relatively large ram-air inflated fabric airfoils being examined to flap and oscillate uncontrolled in the wind tunnel airflow. This chaotic combination of motion and forces could damage the fragile precision balances currently used. Due to the relatively recent development of wingsuit flight as an active sport, there is very little background literature on wingsuit aerodynamics, wingsuit testing, and the equipment and sensors required. A new balance design, able to accurately measure and record basic lift and drag forces while also being able to withstand the potentially destructive unstable response of flexible fabric airfoils at airspeeds of up to 180 knots was required. An additional requirement was introduced by a severely constrained budget supporting this research. There are several basic and inexpensive wind tunnel balance designs. Commercially available, highly accurate balances can easily cost $100 thousand. Accurate commercial two or three component balances can cost tens of thousands of dollars. For this research simple balance designs were modified to provide a more robust interface. A simple balance design was developed using capacitance sensors with the required accuracy, and inertial damping was added to reduce the potential of forces generated damaging the balance and sensors. A balance was developed for less than$5000 that is capable of generating the data required for credible wingsuit aerodynamic research. The details of design process, components, assembly, and calibration are presented

Aerodynamic Forces on Flight Crew Helmets

Wind tunnel tests were conducted to deter- mine the aerodynamic forces generated on aircrew flight helmets. Three helmets were tested: two used by aircrews flying ejection seat aircraft in the U.S. military, the Navy HGU-33/P and the Air Force HGU-53/P; and one prototype helmet of significantly different shape and volume. Axial and normal forces were measured through a range of pitch and yaw angles. It was found that large forces exist tending to promote helmet loss during ejection, and that simple modifications to the current helmet configurations can reduce those forces by as much as 40%. It is demonstrated that the proper design of future helmet external geometry can contribute to the increased safety and survivability of aircrews in the ejection environment

Late Morning Concurrent Sessions: Innovations in Aviation Technologies: Presentation: Wingsuit Materials Research – The Effect of Currently Used Materials on Wingsuit Aerodynamics.

While wingsuit flight is exhilarating and one of the fastest growing facets of sport skydiving, current wingsuit performance is poor at best. A sailplane purpose built for maximum glide ratio might have a glide ratio of 30:1 (30 feet of forward motion for every 1 foot of altitude loss). A Cessna 172, general aviation aircraft has a power off glide ratio of 9:1. Expert, world class wingsuit pilots can barely maintain steady-state glide ratios significantly greater than 3:1. Our project’s long term goal is to significantly increase the glide ratio performance of wingsuit flight. Research to develop the next generation of wingsuit has to ask the question, even before designing wings or configurations: Of what material will new wingsuit designs be made? There is little in the literature about the effect on aerodynamic lift of fabrics at the airspeeds and Reynolds numbers at which wingsuits operate. This research begins to fill that gap in the current literature. Wind tunnel research examining the aerodynamic properties of currently used wingsuit construction materials and various currently used combinations of materials were tested. Testing was done in the Embry-Riddle Aeronautical University, Doryland Wind Tunnel Laboratory in Prescott, Arizona. This low-speed wind tunnel with a 32” x 45” test section was used to test the range of fabrics used for current wingsuit designs through a range of airspeeds from 60 to 140 knots. This covers the range of normal wingsuit flight. A baseline low aspect ratio wing, with a span of 24” and a chord of 12”, using a NACA 4418 airfoil, and with a smooth painted surface typical of a normal aircraft was fabricated. The lift and drag of this wing was measured through the range of airspeeds tested. The wing upper and lower surfaces were then clad with the fabrics currently used in wingsuit construction and the lift and drag of the wing again measured and compared to the baseline smooth wing. The results show significant differences in the aerodynamic properties of the materials tested and point to logical preferences of materials to construct next generation wingsuit designs. From this information, estimations of possible lift and drag of proposed new wingsuit configurations could be derived to predict glide ratio performance. The information already collected also shows unexpected relationships of fabric roughness with aerodynamic performance and increased speed. This is the first step in development of a next generation wingsuit with increased performance and safety

Decreased SMG7 expression associates with lupus-risk variants and elevated antinuclear antibody production

OBJECTIVES: Following up the SLE GWAS identification of NMNAT2 at rs2022013, we fine-mapped its 150kb flanking regions containing NMNAT2 and SMG7 in a 15,292 case-control multi-ancestry population and tested functions of identified variants. METHODS: We performed genotyping using custom array, imputation by IMPUTE 2.1.2, and allele specific functions using qRT-PCR and luciferase reporter transfections. SLE PBMCs were cultured with siRNAs to measure antinuclear antibody (ANA) and cyto/chemokine levels in supernatants using ELISA. RESULTS: We confirmed association at NMNAT2 in European American (EA) and Amerindian/Hispanic ancestries, and identified independent signal at SMG7 tagged by rs2702178 in EA only (P=2.4×10(−8), OR=1.23 [95%CI=1.14–1.32]). In complete linkage disequilibrium with rs2702178, rs2275675 in the promoter region robustly associated with SMG7 mRNA levels in multiple expression quantitative trait locus datasets. Its risk allele was dose-dependently associated with decreased SMG7 mRNA levels in PBMCs of 86 SLE patients and 119 controls (P=1.1×10(−3) and 6.8×10(−8), respectively) and conferred reduced transcription activity in transfected HEK-293 and Raji cells (P=0.0035 and 0.0037, respectively). As a critical component in the nonsense-mediated mRNA decay pathway, SMG7 could regulate autoantigens including RNP and Sm. We showed SMG7 mRNA levels in PBMCs correlated inversely with ANA titers of SLE patients (r=−0.31, P=0.01), and SMG7 knockdown increased levels of ANA IgG and CCL19 in SLE PBMCs (P=2.0×10(−5) and 2.0×10(−4), respectively). CONCLUSIONS: We confirmed NMNAT2 and identified independent SMG7 association with SLE. The inverse relationship between levels of the risk-allele associated SMG7 mRNAs and ANA suggested the novel contribution of mRNA surveillance pathway to SLE pathogenesis

Decreased SMG7 expression associates with lupus-risk variants and elevated antinuclear antibody production

Objectives Following up the systemic lupus erythematosus (SLE) genome-wide association studies (GWAS) identification of NMNAT2 at rs2022013, we fine-mapped its 150a €...kb flanking regions containing NMNAT2 and SMG7 in a 15a €...292 case-control multi-ancestry population and tested functions of identified variants. Methods We performed genotyping using custom array, imputation by IMPUTE 2.1.2 and allele specific functions using quantitative real-time PCR and luciferase reporter transfections. SLE peripheral blood mononuclear cells (PBMCs) were cultured with small interfering RNAs to measure antinuclear antibody (ANA) and cyto/chemokine levels in supernatants using ELISA. Results We confirmed association at NMNAT2 in European American (EA) and Amerindian/Hispanic ancestries, and identified independent signal at SMG7 tagged by rs2702178 in EA only (p=2.4×10 a '8, OR=1.23 (95% CI 1.14 to 1.32)). In complete linkage disequilibrium with rs2702178, rs2275675 in the promoter region robustly associated with SMG7 mRNA levels in multiple expression quantitative trait locus (eQTL) datasets. Its risk allele was dose-dependently associated with decreased SMG7 mRNA levels in PBMCs of 86 patients with SLE and 119 controls (p=1.1×10 a '3 and 6.8×10 a '8, respectively) and conferred reduced transcription activity in transfected HEK-293 (human embryonic kidney cell line) and Raji cells (p=0.0035 and 0.0037, respectively). As a critical component in the nonsense-mediated mRNA decay pathway, SMG7 could regulate autoantigens including ribonucleoprotein (RNP) and Smith (Sm). We showed SMG7 mRNA levels in PBMCs correlated inversely with ANA titres of patients with SLE (r=a '0.31, p=0.01), and SMG7 knockdown increased levels of ANA IgG and chemokine (C-C motif) ligand 19 in SLE PBMCs (p=2.0×10 a '5 and 2.0×10 a '4, respectively). Conclusion We confirmed NMNAT2 and identified independent SMG7 association with SLE. The inverse relationship between levels of the risk allele-associated SMG7 mRNAs and ANA suggested the novel contribution of mRNA surveillance pathway to SLE pathogenesis. © 2016 Published by the BMJ Publishing Group Limited

Decreased SMG7 expression associates with lupus-risk variants and elevated antinuclear antibody production

Objectives Following up the systemic lupus erythematosus (SLE) genome-wide association studies (GWAS) identification of NMNAT2 at rs2022013, we fine-mapped its 150a €...kb flanking regions containing NMNAT2 and SMG7 in a 15a €...292 case-control multi-ancestry population and tested functions of identified variants. Methods We performed genotyping using custom array, imputation by IMPUTE 2.1.2 and allele specific functions using quantitative real-time PCR and luciferase reporter transfections. SLE peripheral blood mononuclear cells (PBMCs) were cultured with small interfering RNAs to measure antinuclear antibody (ANA) and cyto/chemokine levels in supernatants using ELISA. Results We confirmed association at NMNAT2 in European American (EA) and Amerindian/Hispanic ancestries, and identified independent signal at SMG7 tagged by rs2702178 in EA only (p=2.4×10 a '8, OR=1.23 (95% CI 1.14 to 1.32)). In complete linkage disequilibrium with rs2702178, rs2275675 in the promoter region robustly associated with SMG7 mRNA levels in multiple expression quantitative trait locus (eQTL) datasets. Its risk allele was dose-dependently associated with decreased SMG7 mRNA levels in PBMCs of 86 patients with SLE and 119 controls (p=1.1×10 a '3 and 6.8×10 a '8, respectively) and conferred reduced transcription activity in transfected HEK-293 (human embryonic kidney cell line) and Raji cells (p=0.0035 and 0.0037, respectively). As a critical component in the nonsense-mediated mRNA decay pathway, SMG7 could regulate autoantigens including ribonucleoprotein (RNP) and Smith (Sm). We showed SMG7 mRNA levels in PBMCs correlated inversely with ANA titres of patients with SLE (r=a '0.31, p=0.01), and SMG7 knockdown increased levels of ANA IgG and chemokine (C-C motif) ligand 19 in SLE PBMCs (p=2.0×10 a '5 and 2.0×10 a '4, respectively). Conclusion We confirmed NMNAT2 and identified independent SMG7 association with SLE. The inverse relationship between levels of the risk allele-associated SMG7 mRNAs and ANA suggested the novel contribution of mRNA surveillance pathway to SLE pathogenesis. © 2016 Published by the BMJ Publishing Group Limited