Voluntary Pilot Action Through Biodynamics for Helicopter Flight Dynamics Simulation

This work presents the integration of detailed models of a pilot controlling a helicopter along the heave axis through the collective control inceptor. The action on the control inceptor is produced through a biomechanical model of the pilot’s limbs, by commanding the activation of the related muscle bundles. Such activation, in turn, is determined by defining the muscle elongations required to move the control inceptor in order to obtain the control of the vehicle according to a high-level model of the voluntary action of the pilot acting as a regulator for the vehicle. The biomechanical model of the pilot’s limbs and the aeromechanical model of the helicopter are implemented in a general-purpose multibody simulation. The helicopter model, the biomechanical model of the pilot’s limbs, the cognitive model of the pilot, and their integration are discussed. The integrated model is applied to the simulation of simple, yet representative, mission task elements

Comportamento de forrageiras nativas em sistemas silvipastoris com acácia-negra no Rio Grande do Sul.

As plantações de acácia-negra do Rio Grande do Sul são tradicionalmente utilizadas em sistemas silvipastoris. O objetivo deste trabalho foi avaliar o comportamento das principais forrageiras das pastagens nativas sob o sombreamento desta plantação florestal. Foram avaliadas a cobertura das espécies herbáceas em plantações de acácia-negra com 1, 2 e 6 anos de idade e de um campo nativo sem a presença de árvores. As avaliações foram realizadas através da estimativa visual de cobertura das espécies, solo descoberto e material morto. As gramíneas apresentaram a maior cobertura, tanto nas áreas de plantações florestais como no campo aberto. As pastagens sob sombreamento apresentaram menor porcentagem de solo descoberto, indicando a adaptação da vegetação herbácea ao sombreamento. Observaram-se diferentes respostas das espécies nativas ao sombreamento. Paspalum notatum e Axonopus affinis, reduziram sua cobertura ou tenderam a desaparecer das áreas com plantações de acácia-negra. Por outro lado, Piptochaetium montevidense e Dichantelium sabulorum mantiveram ou aumentaram sua cobertura nas áreas com acácia-negra, indicando a tolerância destas espécies ao sombreamento. Observou-se também que gramíneas típicas de sub-bosques de fragmentos florestais nativos, como Homolepis glutinosa, Paspalum mandiocanum, Oplismenus hirtelus, Panicum sellowii e P. pantrichum, colonizaram as plantações de acácia-negra, sendo sua dispersão facilitada pelos bovinos que utilizaram a área para pastoreio

Experimental and numerical analysis of hovering multicopter performance in low-Reynolds number conditions

Unmanned Aircraft Systems (UAS) are state of the art in the aerospace industry and are involved in many operations. Although initially developed for military purposes, commercial applications of small- scale UAS, such as multicopters, are abundant today. Accurate engineering tools are required to assess the performance of these vehicles and optimize power consumption. The thrust and power curves of the rotors used by small-scale UAS are essential elements in designing efficient aircraft. The scarcity of experimental data and sufficiently accurate prediction models to evaluate rotor aerodynamic performance in the flight envelope are primary limitations in UAS science. In addition, for small-scale rotors at usual rotation rates, chord-based Reynolds numbers are typically smaller than 100,000, a flow regime in which performance tends to degrade. In this paper, experimental data on small-scale multicopter propulsion systems are presented and combined with a Computational Fluid Dynamics (CFD) model to describe the aerodynamics of these vehicles in low Reynolds numbers conditions. We use the STAR-CCM+ software to perform CFD simulations adopting both a dynamic-grid, time-accurate analysis and a static-grid, steady- state technique that solves the Navier-Stokes equations in a suitable framework. Comparing numerical simulation results on a conventional UAS propeller with related experimental data suggests that the proposed approach can correctly describe the thrust and torque coefficients in the range of Reynolds numbers characterizing the UAS flight envelope

UAV-spray application in vineyards: Flight modes and spray system adjustment effects on canopy deposit, coverage, and off-target losses

Improvements in the spray application of plant protection products enhance agricultural sustainability by reducing environmental contamination, but by increasing food quality and human safety. Currently, Unmanned Aerial Vehicles (UAVs) are raising interest in spray applications in 3D crops. However, operational configurations of UAV-spray systems need further investigation to maximise the deposition in the canopy and minimise the off-target losses. Our experimental research focused on investigating the effects on the canopy spray deposition and coverage due to different UAV-spray system configurations. Twelve configurations were tested under field conditions in an experimental vineyard (cv. Barbera), derived from the combination of different UAV flight modes (band and broadcast spray applications), nozzle types (conventional and air inclusion), and UAV cruise speeds (1 and 3 m s-1). Also, the best treatment, among those tested, by using the UAV-spray system and a traditional airblast sprayer were compared. The data was analysed by testing the effects of the three operational parameters and their two- and three-way interactions by means of linear mixed models. The results indicated that the flight mode deeply affects spray application efficiency. Compared to the broadcast spray modes, the band spray mode was able to increase the average canopy deposition from 0.052 to 0.161 μL cm-2 (+ 309 %) and reduce the average ground losses from 0.544 to 0.246 μL cm-2 (- 54 %). The conventional airblast sprayer, operated at a low spray application rate, showed higher canopy coverage and lower ground losses in comparison to the best UAV-spray system configuration

Imaging mass cytometry analysis of Becker muscular dystrophy muscle samples reveals different stages of muscle degeneration

\ua9 2024. The Author(s). Becker muscular dystrophy (BMD) is characterised by fiber loss and expansion of fibrotic and adipose tissue. Several cells interact locally in what is known as the degenerative niche. We analysed muscle biopsies of controls and BMD patients at early, moderate and advanced stages of progression using Hyperion imaging mass cytometry (IMC) by labelling single sections with 17 markers identifying different components of the muscle. We developed a software for analysing IMC images and studied changes in the muscle composition and spatial correlations between markers across disease progression. We found a strong correlation between collagen-I and the area of stroma, collagen-VI, adipose tissue, and M2-macrophages number. There was a negative correlation between the area of collagen-I and the number of satellite cells (SCs), fibres and blood vessels. The comparison between fibrotic and non-fibrotic areas allowed to study the disease process in detail. We found structural differences among non-fibrotic areas from control and patients, being these latter characterized by increase in CTGF and in M2-macrophages and decrease in fibers and blood vessels. IMC enables to study of changes in tissue structure along disease progression, spatio-temporal correlations and opening the door to better understand new potential pathogenic pathways in human samples

Emotional impact of genetic trials in progressive paediatric disorders: a dose-ranging exon-skipping trial in Duchenne muscular dystrophy.

Gene-modifying trials offer hope for improvement in chronic paediatric disorders, but they may also lead to disappointment and have an adverse emotional effect on families. This study aimed to examine emotional impact on participants in a paediatric exon-skipping trial

Findings from the Longitudinal CINRG Becker Natural History Study

BACKGROUND: Becker muscular dystrophy is an X-linked, genetic disorder causing progressive degeneration of skeletal and cardiac muscle, with a widely variable phenotype. OBJECTIVE: A 3-year, longitudinal, prospective dataset contributed by patients with confirmed Becker muscular dystrophy was analyzed to characterize the natural history of this disorder. A better understanding of the natural history is crucial to rigorous therapeutic trials. METHODS: A cohort of 83 patients with Becker muscular dystrophy (5-75 years at baseline) were followed for up to 3 years with annual assessments. Muscle and pulmonary function outcomes were analyzed herein. Age-stratified statistical analysis and modeling were conducted to analyze cross-sectional data, time-to-event data, and longitudinal data to characterize these clinical outcomes. RESULTS: Deletion mutations of dystrophin exons 45-47 or 45-48 were most common. Subgroup analysis showed greater pairwise association between motor outcomes at baseline than association between these outcomes and age. Stronger correlations between outcomes for adults than for those under 18 years were also observed. Using cross-sectional binning analysis, a ceiling effect was seen for North Star Ambulatory Assessment but not for other functional outcomes. Longitudinal analysis showed a decline in percentage predicted forced vital capacity over the life span. There was relative stability or improved median function for motor functional outcomes through childhood and adolescence and decreasing function with age thereafter. CONCLUSIONS: There is variable progression of outcomes resulting in significant heterogeneity of the clinical phenotype of Becker muscular dystrophy. Disease progression is largely manifest in adulthood. There are implications for clinical trial design revealed by this longitudinal analysis of a Becker natural history dataset