Analysis and Testing of Aerobatic Turboprop Aircraft Inlet

Aerobatic aircraft have become popular for the training of military pilots, and nowadays an increasing number of such airframes are being developed. Modern turboprop engines provide high performance allowing the pilots to get similar handling characteristics to military jet aircraft engines. Prior to the availability of high performance turboprops, the basic pilot training was conducted using jet aircraft. Furthermore, the introduction of electronic control systems on last-generation turboprop engines enables single lever control, making it an ideal candidate for this type of aerobatic and training airframes. This new type of engine operation is however accompanied by several challenges from the point of view of the engine design and installation aerodynamics. GEAC has gone through a complex design process, in cooperation with the airframer, to validate the design of a new aerobatic aircraft inlet in the context of developing an aerobatic version of the H80 engine. In order to ensure a) surge-free operation, b) optimal engine performance and c) effective ice/FOD separation in inclement weather conditions and during any kind of aerobatic maneuver, the team has done extensive CFD predictions of the flow behaviour, performance/operability studies and finally a ground test campaign. First, a back-to-back comparison of the aerobatic inlet geometry versus a reference commuter inlet geometry was conducted. Then, flight conditions were simulated in calm and crosswind environments. Distortion patterns were examined using in-house developed tools and the diverse sources of distortion were identified. One of the results is the introduction of geometry improvements to guarantee improved performance and extended engine operability range. Advanced propeller modeling techniques were introduced and benchmarked in order to have the most exact representation of the propeller aerodynamic effect on inlet flow. Finally, a test campaign was conducted for validation purposes. An exhaustive instrumentation, data acquisition system and detailed test program were developed to validate CFD methods and assumptions made during the design phase, and to raise our confidence in the flight conditions simulation results.

Effect of hippotherapy in the global motor coordination in individuals with Down Syndrome

Introduction: Down syndrome (DS) of all genetic syndromes is the most common. In Hippotherapy, three-dimensional movements, provided by horse walking, awaken in the body of children with DS a large amount of sensory and neuromuscular stimuli, which directly interfere with overall development and the acquisition of motor skills. Objective: To analyze the effects of an Hippotherapy program on global motor coordination variables in individuals with DS of both genders and to compare individuals with the same syndrome who do not practice Hippotherapy. Methods: 41 individuals participated in the study, 20 of them practicing Hippotherapy (EG) and 21 who did not practice Hippotherapy (CG). The Körperkoordinations test für Kinder (KTK) test was used, consisting of four tasks: Balance on beams, Single-lever jump, Side-jump and Transfer on platform for analysis of motor coordination for individuals. Results: Comparing the groups, a significant difference (p < 0.01) was observed for the Lateral Leap Motor Quotient, the EG presented a better score (114.10) than the CG (88.47), and also in the Total Motor Ratio (EG = 115.10, GC = 102.47). The individuals that practice Hippotherapy presented better results in the global motor coordination, with significant difference (p < 0.05). In EG, 5% had high global motor coordination, 40% good and 55% normal, whereas in CG only 10% had good global motor coordination and 90% normal global motor coordination. Conclusion: It can be emphasized that equine therapy presents benefits of improvement in global motor coordination. Specifically in tasks such as the balance beam, single jump and side jump, besides global motor coordination.

In vivo myosin step-size from zebrafish skeletal muscle

Muscle myosins transduce ATP free energy into actin displacement to power contraction. In vivo , myosin side chains are modified post-translationally under native conditions, potentially impacting function. Single myosin detection provides the ‘bottom-up’ myosin characterization probing basic mechanisms without ambiguities inherent to ensemble observation. Macroscopic muscle physiological experimentation provides the definitive ‘top-down’ phenotype characterizations that are the concerns in translational medicine. In vivo single myosin detection in muscle from zebrafish embryo models for human muscle fulfils ambitions for both bottom-up and top-down experimentation. A photoactivatable green fluorescent protein (GFP)-tagged myosin light chain expressed in transgenic zebrafish skeletal muscle specifically modifies the myosin lever-arm. Strychnine induces the simultaneous contraction of the bilateral tail muscles in a live embryo, causing them to be isometric while active. Highly inclined thin illumination excites the GFP tag of single lever-arms and its super-resolution orientation is measured from an active isometric muscle over a time sequence covering many transduction cycles. Consecutive frame lever-arm angular displacement converts to step-size by its product with the estimated lever-arm length. About 17% of the active myosin steps that fall between 2 and 7 nm are implicated as powerstrokes because they are beyond displacements detected from either relaxed or ATP-depleted (rigor) muscle.

Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion

Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor’s processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor’s structure. Specifically, changes in calcium may regulate motor processivity by altering the motor’s lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor’s flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network.

Design of the Tracked Vehicle Based on the STM32

As the crawler vehicle with the excellent off-road performance, the battlefield survival ability, etc , are widely used in modern weapons systems In order to make teaching model close to the real equipment , designed a tracked vehicle of anti-aircraft gun based on the STM32F103 microcontroller, combined with the H-bridge motor circuit ,photoelectric encoder angle measurement and control principle of single lever operation, experimental results show that the tracked vehicle can complete forward, backward , turning and braking actions in accordance with the control command , with fast dynamic response , high control precision , to meet the design requirements.

Differences Between Accumbens Core and Shell Neurons Exhibiting Phasic Firing Patterns Related to Drug-Seeking Behavior During a Discriminative-Stimulus Task

The habit-forming effects of abused drugs depend on the mesocorticolimbic dopamine system innervating the nucleus accumbens (NAcc). To examine whether different NAcc subterritories (core and medial shell) exhibit a differential distribution of neurons showing phasic firing patterns correlated with drug-seeking behavior, rats were trained to self-administer cocaine, and activity of single NAcc neurons was recorded. In the presence of a discriminative-stimulus (SD) tone, a single lever press produced an intravenous infusion of cocaine (0.35 mg/kg), terminated the tone, and started an intertone interval ranging from 3 to 6 min. Lever presses during this intertone interval had no programmed consequences. In addition to evaluating neuronal firing patterns associated with cocaine-reinforced presses, we also evaluated firing patterns associated with unreinforced lever presses to allow interpretation of firing free of factors other than the instrumental response (such as tone-off and onset of the pump signaling drug infusion). Core neurons exhibited a greater change in firing than medial shell neurons both in the seconds preceding the reinforced and unreinforced lever press response and in the seconds following the unreinforced response. Core and medial shell neurons exhibited similar changes in firing during the seconds following the cocaine-reinforced press. The differential distribution of neurons exhibiting phasic changes in firing preceding the lever press suggests that the physiological activity of core neurons may play a greater role than that of medial shell neurons in processes related to the execution of conditioned drug-seeking responses.