Minutes Of Flight Research Articles

Behavioural and physiological responses of captive Antillean manatees to small aerial drones

Abstract Context Unmanned aerial vehicles or drones are powerful tools for wildlife research. Identifying the impacts of these systems on target species during operations is essential to reduce risks of disturbance to wildlife, to minimise bias in behavioural data, and to establish better practices for their use. Aims We evaluated the responses of captive Antillean manatees to the overhead flight of a small aerial drone. Methods We used aerial and ground videos to compare manatee activity budgets and respiration rates in three 15-min sampling periods: ‘before’, ‘during’ and ‘after’ flights with a DJI Phantom 3 Advanced. The drone was hovered stationary for 3 min at five altitudes (100 m, 40 m, 20 m, 10 m, 5 m) to determine whether manatees display behavioural responses compared with the control period, and whether they respond more at lower altitudes. Only one flight was performed per manatee group to avoid bias owing to habituation to the drone. Key results Manatees responded to drone flights by (1) increasing their activity levels during and after flights, therefore signalling after effects; (2) decreasing their respiration rate during flights; and (3) displaying behavioural reactions including grouping, tail-kicking, fleeing from their original position and moving under submerged structures. From the 11 individuals displaying behavioral reactions, 9 reacted in the first ~2 min of flight, preventing assessments of altitude effects and suggesting manatees responded to the drone sound at take-off. Conclusions Behavioural changes of responding manatees were similar to previous reports of disturbance responses to boats and drones in this species. Our use of a control period showed shifts in respiration rates and activity budgets that persisted after flights. Several manatees reacted to the drone from the time of take-off and first minutes of flight, indicating that the sound of the electric rotors could be a strong negative stimulus to manatee and highlighting the importance of establishing safe distances for take-off. Implications Future studies should consider that drones could elicit conspicuous and inconspicuous responses in manatees. Our results emphasise the need for control data on animal behaviour to better assess the impact of drones on wildlife and to design non-invasive protocols.

Use of Drones to Recover Fungal Spores and Pollen from the Lower Atmosphere

Aerobiological studies focus on studying biological particulates such as pollen and fungal spores in the lower atmosphere. Dispersion of these bio particulates is widespread, and their capture can be difficult, requiring the development and use of different methods to achieve their capture. For this research, a modified unmanned aerial vehicle, commonly known as drone, fitted with remote-controlled spore traps was used to collect spores and pollen from the lower atmosphere. Samplings of five minutes of flight with the samplers open and Petri dishes exposed to collect viable particulate were made above two areas with different anthropogenic activity. Adhesive slides were exposed simultaneously to collect non-viable particulate. From viable samples, common fungi such as Cladosporium, Curvularia, Fusarium, Penicillium, Aspergillus, and Nigrospora were identified. From non-viable samples, 54 genera of fungal spores and 17 pollen genera were observed directly under the microscope. Spores of Delitschia, Solheimia, Venturia, Fusariella, Endophragmiella, and Polythrincium are reported here as new records for Puerto Rico.

Solar Autopilot Drone

Advances in technology have made the drone an affordable tool for various purposes. This article focuses on gaining knowledge of drone at a working and conceptual level. Firstly, there is a detailed explanation of the construction of the drone. Some of the most essential elements of a drone include frame, propellers, engine, system of power the electronic control and communication system. Whether you fly your drone for commercial or recreational purposes, staying in the air as long as possible is the goal. But of course, the battery life of the drone can put a damper on how much you can accomplish while you’re flying.Batteries serve as a major drawback because they get exhausted after 15 minutes of flight and thereby landing the drone on ground. The batteries used for powering the drones are lithium-polymer batteries.This project aims to provide an ingenious solution to this hurdle by introducing the current popular photovoltaic system into the UAV power system design.Solar drones use solar cells powered directly from the sun and solve major issues related to conventional drones such as increasing the flight time and risk of the drone losing connectivity with its controller. The design is to be modular for easy module upgrade and replacement. Using photovoltaic system minimizes the environmental impact, an issue that can be controversial for large projects built for utilities because they tend to spread across hundreds of acres of land in remote regions.

Space shuttle’s liftoff: a didactical model∗∗To the STS-51-L and STS-107 astronauts, in memoriam.

The pedagogical aim of the present paper, thought for an undergraduate audience, is to help students to appreciate how the development of elementary models based on physics first principles is a fundamental and necessary preliminary step for the behaviour of complex real systems to be grasped with minimal amounts of math. In some particularly fortunate cases, such models also show reasonably good results when are compared to reality. The speed behaviour of the Space Shuttle during its first two minutes of flight from liftoff is here analysed from such a didactical point of view. Only the momentum conservation law is employed to develop the model, which is eventually applied to quantitatively interpret the telemetry of the 2011 last launches of Shuttle Discovery and Shuttle Endeavour.

Flight‐oogenesis syndrome in a blood‐sucking bug: Biochemical aspects of lipid metabolism

Lipophorin (Lp), either labeled in diacylglycerol moiety with [(3)H]-Palmitic acid or in phospholipid moiety with (32)Pi, was injected into Rhodnius prolixus females. Insects were induced to flight for different times. In just a few minutes of flight, the transfer of radioactivity to ovaries decreased, accompanied by its increase to flight muscles. After one hour of flight, Lp density was higher (1.132 g/mL) than before flight (1.116 g/mL). Lp purified from insects after flight was analyzed by gel filtration chromatography and a polyacrylamide gel pore limit electrophoresis. Both analyses demonstrated a decrease in Lp molecular mass after flight but no changes in apoLp-III amounts were observed. Time-course experiments showed that only 30 min of flight are required for the detection of changes in Lp density and molecular mass. About the same time of rest is necessary for Lp density and molecular mass to return to the baseline value. The lipid content from Lp particles, determined by high-performance thin-layer chromatography (HPTLC), showed a decrease in total lipids after flight. At the same time, an increase of many classes of lipids was observed in flight muscles except for triacylglycerol, which was reduced. The increase of flight muscle lipids was accompanied by a decrease of the ovaries lipid content. The insects subjected to daily exhaustive flight showed a significant decrease in total number of eggs produced. But insects subjected to a single exhaustive flight showed only a small reduction in total number of eggs. Lp density variation during the flight activity of Rhodnius prolixus females is discussed in association with physiological events such as oogenesis.

?Biological noise? and plasticity of sensorimotor pathways in the locust flight system

1. Locusts (Locusta migratoria) are flown in a flight simulator in which the relative timing of two flight muscles is used to control the yaw angle. These closed-loop muscles always show a strict correlation to the reference value of the feedback circuit whereas the timing of other muscles (in open-loop) is largely independent of the reference value. 2. The strength of steering reactions in different flight muscles — tested with short imposed yaw stimuli — depends on whether the respective muscles during a particular flight are in closed loop or in open loop within the flight simulator feedback. Closed-loop muscles react stronger to the yaw stimuli than open-loop muscles. 3. Closed-loop and open-loop muscles can be interchanged with one another during a flight. Concurrent changes in yaw sensitivity of the open-loop and closed-loop muscles develop within several minutes of flight. 4. A logical scheme is proposed which explains the specific adjustment of the sensorimotor pathways. It takes into account the spontaneous fluctuations of the motor pattern (‘biological noise’) which serve as ‘ exploratory manoeuvers’ for the muscle specific adjustment of sensorimotor strength.

Space Shuttle guidance for multiple main engine failures during first stage

This paper presents contingency abort guidance schemes recently developed for multiple Space Shuttle main engine failures during the first two minutes of flight (first stage). The ascent and entry guidance schemes greatly improve the possibility of the crew and/or the Orbiter surviving a first stage contingency abort. Both guidance schemes were required to meet certain structural and controllability constraints. In addition, the systems were designed with the flexibility to allow for seasonal variations in the atmosphere and wind. The ascent scheme guides the vehicle to a desirable, lofted state at solid rocket booster burnout while reducing the structural loads on the vehicle. After Orbiter separation from the solid rockets and the external tank, the entry scheme guides the Orbiter through one of two possible entries. If the proper altitude/range/velocity conditions have been met, a return-to-launch-site 'Split-S' maneuver may be attempted. Otherwise, a down-range abort to an equilibrium glide and subsequent crew bailout is performed.

Fructose 2,6-bisphosphate as a signal for changing from sugar to lipid oxidation during flight in locusts

Flight in locusts is initially powered mainly by carbohydrate but if flight is to be sustained, as in migration, the animals have to utilize fat as the predominant fuel. The molecular basis of this metabolic switch has not been identified. Fructose 2,6-bisphosphate is a potent activator of 6-phosphofructokinase (EC 2.7.1.11) purified from locust flight muscle. After the first few minutes of flight in the locust the concentration of fructose 2,6-bisphosphate in the flight muscle falls dramatically, which should lead to a decrease in the activity of 6-phosphofructokinase as part of the mechanism to conserve carbohydrate during prolonged flight.

The release and removal of octopamine by tissues of the locust Schistocerca americana gregaria

The octopamine content of dorsal longitudinal nerves and of dorso-ventral nerve-muscle tissues was lower in locusts flown for 10 min than in unflown controls. No such change was found for the octopamine content of brain or thoracic ganglia. Endogenous octopamine was released from isolated working thoracic muscle preparations perfused in the presence of yohimbine. It is proposed that release of octopamine from thoracic nerves can account for much of the increase in octopamine that occurs in haemolymph during the first few minutes of flight. Octopamine injected into locusts in vivo was rapidly removed from the haemolymph. In vitro experiments showed that Malpighian tubules were effective at removing octopamine added to the incubation medium. When the octopamine content of crude tissue preparations such as whole tagmata is estimated by radioenzymatic procedures, erroeneously high results are obtained unless precautions are taken to purify the labelled product.

Amino acid metabolism during flight in the Colorado potato beetle, Leptinotarsa decemlineata

The highest capacity for flight was demonstrated in males reared in long day conditions. During flight there is a significant decrease in proline content and to a lesser extent in glutamate. At the same time alanine accumulates, but its accumulation does not show stoichiometry with the decline in proline and glutamate during the first minutes of flight. This failure in stoichiometry suggests that glutamate dehydrogenase plays an important role in the early phases of flight.

On the Accuracy of Wind Measurements Using an Inertial Platform in an Aircraft, and an Example of a Measurement of the Vertical Mesostructure of the Atmosphere

A high quality inertial navigation platform, originally developed for the TSR 2 aircraft, is now being used by the Meteorological Research Flight in order to measure vertical gust velocities and horizontal wind shear from a Canberra PR 3 aircraft. The equations are derived from which the vertical and horizontal winds are calculated, and an assessment is made of the accuracy of measurement which can be expected for vertical gusts and horizontal shear. Measurements of the residual error velocities which occur when the aircraft is made to pitch, roll and yaw are shown to lie within the theoretical limits, and an example of the velocities derived from a straight and level run in smooth air is also described. The use of this equipment to measure the small-scale variations in wind shear and vertical gusting when the aircraft descends through a layer of turbulence is then described, and the results of one of the first of a series of such flights are given. With the present recording system, the extraction of data for the analysis of a few minutes of flight is lengthy, but it is hoped that a data recording system will be installed in the future. The system will then become a quick and accurate method of measuring the mesoscale structure of the gusts and shears in the atmosphere.