Search results for "Flight"

Optimal Flight Path Determination in Turbulent Air: A Modified EKF Approach

2018

By using the Extended Kalman Filter an accurate path following in turbulent air is performed. The procedure employs simultaneously two dierent EKFs: the rst one estimates disturbances, the second one aords to determine the necessary controls displacements for rejecting those ones. To tune the EKFs an optimization algorithm has been designed to automatically determine Process Noise Covariance and Measurement Noise Covariance matrices. The rst lter, by using instrumental measurements gathered in turbulent air, estimates wind components. The second one obtains command laws able to follow the desired ight path. To perform this task aerodynamic coecients have been modied. Such a procedure leads …

Flying insects: model systems in exercise physiology

1996

Insect flight is the most energy-demanding exercise known. It requires very effective coupling of adenosine triphosphate (ATP) hydrolysis and regeneration in the working flight muscles.31P nuclear magnetic resonance (NMR) spectroscopy of locust flight muscle in vivo has shown that flight causes only a small decrease in the content of ATP, whereas the free concentrations of inorganic phosphate (P i ), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were estimated to increase by about 3-, 5- and 27-fold, respectively. These metabolites are potent activators of glycogen phosphorylase and phosphofructokinase (PFK). Activation of glycolysis by AMP and P i is reinforced synergistica…

Sensorimotor adaptation of point-to-point arm movements after spaceflight: the role of internal representation of gravity force in trajectory plannin…

2011

International audience; After an exposure to weightlessness, the central nervous system operates under new dynamic and sensory contexts. To find optimal solutions for rapid adaptation, cosmonauts have to decide whether parameters from the world or their body have changed and to estimate their properties. Here, we investigated sensorimotor adaptation after a spaceflight of 10 days. Five cosmonauts performed forward point-to-point arm movements in the sagittal plane 40 days before and 24 and 72 h after the spaceflight. We found that, whereas the shape of hand velocity profiles remained unaffected after the spaceflight, hand path curvature significantly increased 1 day after landing and return…

The effects of light exposure on the cortisol stress response in human males.

2020

It is assumed that the production of cortisol is modulated by light exposure. While initial evidence supports this principal effect, the specific effect of light (intensity and wavelength) onto the cortisol stress response is still not completely understood. One between-subject experiment was conducted in a standardized sleep laboratory setting to investigate the effect of light intensity (dim white vs. bright white light) and spectral composition (red vs. blue) on the cortisol response after the Maastricht Acute Stress Test (MAST). 112 healthy young males (24.83 ± 4.10 years of age) were randomly assigned to one of the four light conditions. Across conditions, light exposure was conducted …

Comparison of Cortisol Stress Response in Patients with Panic Disorder, Cannabis-Induced Panic Disorder, and Healthy Controls

2018

<b><i>Background/Aims:</i></b> Little research effort has so far been dedicated to the analysis of the hypothalamic-pituitary-adrenal axis of aetiologically differing subgroups of patients with panic disorder (PD). The current study aimed at a deeper understanding of the cortisol stress response in cannabis-induced PD (CIPD) patients. <b><i>Methods:</i></b> Matched groups of 7 PD patients (mean age ± SD: 32.95 ± 9.04 years), 7 CIPD patients (31.94 ± 8.40 years), and 7 healthy controls (HC) (31.13 ± 8.57 years) were included in the study. The Trier Social Stress Test (TSST) was used for stress induction. Salivary cortisol samples were collected…

Effects of a 21 days space flight on the mechanical performance and the EMG power spectrum of the leg muscles

2002

Axis Rotation and Visually Induced Motion Sickness: The Role of Combined Roll, Pitch, and Yaw Motion

2011

A well-known phenomenon in aviation and in virtual environments such as simulators or computer games is motion sickness (MS). The amount of sensory conflict is thought to be responsible for the severity of MS, which should increase with the complexity of the simulated motion. The focus of the present study is on the direction and complexity of simulated body rotations in the genesis and severity of visually induced MS. The methods utilized for this study are as follows: Three simulated rollercoaster rides including translational movement in the fore-aft axis and additional rotational motion either in pitch only, along the pitch and roll axes, or in pitch, roll, and yaw were generated. The a…

Predicting hypoxia in cystic fibrosis patients during exposure to high altitudes

2006

Abstract Background For patients with cystic fibrosis (CF)-related partial respiratory insufficiency and reduced arterial oxygen tension at ground level, the mild hypobaric environment on commercial jet aircraft poses the risk of severe hypoxemia. Thus, physicians should be able to estimate the extent of in-flight hypoxia. Objectives To derive tools for estimating the expected drop in arterial oxygen partial pressure (paO 2 ) and oxygen saturation (saO 2 ) in young adult CF patients with mild to moderate airway obstruction during exposure to the hypobaric conditions aboard commercial aircraft and to test the predictive power of a hypobaric chamber simulation. Methods Blood gases of 12 CF pa…

Effect of caffeine on simulator flight performance in sleep-deprived military pilot students.

2007

Caffeine has been suggested to act as a countermeasure against fatigue in military operations. In this randomized, double-blind, placebo-controlled study, the effect of caffeine on simulator flight performance was examined in 13 military pilots during 37 hours of sleep deprivation. Each subject performed a flight mission in simulator four times. The subjects received either a placebo (six subjects) or 200 mg of caffeine (seven subjects) 1 hour before the simulated flights. A moderate 200 mg intake of caffeine was associated with higher axillary temperatures, but it did not affect subjectively assessed sleepiness. Flight performance was similar in both groups during the four rounds flown und…

An adaptive display for the treatment of diverse trauma PTSD victims.

2009

El trastorno de estrés postraumático (TEPT) puede desarrollarse después de la exposición a un evento aterrador. Las personas que sufren de trastorno de estrés postraumático presentan hiperactividad y evitación, y experimentan síntomas que provocan angustia y deterioro en áreas de vida significativas. Los programas de comportamiento cognitivo, incluida la terapia de exposición, son actualmente el tratamiento de elección para el TEPT. Aunque estos programas son eficaces, hay margen de mejora; La utilización de la terapia de exposición por los médicos es baja y las tasas de desgaste son altas. La aplicación de nuevas tecnologías, especialmente la realidad virtual (VR), podría ayudar a superar …