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2021 ◽  
Vol 1 ◽  
Author(s):  
Verena Christen ◽  
Daniela Grossar ◽  
Jean-Daniel Charrière ◽  
Michael Eyer ◽  
Lukas Jeker

Neonicotinoids as thiamethoxam and thiacloprid are suspected to be implicated in the decline of honey bee populations. As nicotinic acetylcholine receptor agonists, they disturb acetylcholine receptor signaling in insects, leading to neurotoxicity and are therefore globally used as insecticides. Several behavioral studies have shown links between neonicotinoid exposure of bees and adverse effects on foraging activity, homing flight performance and reproduction, but the molecular aspects underlying these effects are not well-understood. In the last years, several studies through us and others showed the effects of exposure to neonicotinoids on gene expression in the brain of honey bees. Transcripts of acetylcholine receptors, hormonal regulation, stress markers, detoxification enzymes, immune system related genes and transcripts of the energy metabolism were altered after neonicotinoid exposure. To elucidate the link between homing flight performance and shifts in gene expression in the brain of honey bees after neonicotinoid exposure, we combined homing flight activity experiments applying RFID technology and gene expression analysis. We analyzed the expression of endocrine factors, stress genes, detoxification enzymes and genes linked to energy metabolism in forager bees after homing flight experiments. Three different experiments (experiment I: pilot study; experiment II: “worst-case” study and experiment III: laboratory study) were performed. In a pilot study, we wanted to investigate if we could see differences in gene expression between controls and exposed bees (experiment I). This first study was followed by a so-called “worst-case” study (experiment II), where we investigated mainly differences in the expression of transcripts linked to energy metabolism between fast and slow returning foragers. We found a correlation between homing flight duration and the expression of cytochrome c oxidase subunit 5A, one transcript linked to oxidative phosphorylation. In the third experiment (experiment III), foragers were exposed in the laboratory to 1 ng/bee thiamethoxam and 8 ng/bee thiacloprid followed by gene expression analysis without a subsequent flight experiment. We could partially confirm the induction of cytochrome c oxidase subunit 5A, which we detected in experiment II. In addition, we analyzed the effect of the feeding mode (group feeding vs. single bee feeding) on data scattering and demonstrated that single bee feeding is superior to group feeding as it significantly reduces variability in gene expression. Based on the data, we thus hypothesize that the disruption of energy metabolism may be one reason for a prolongation of homing flight duration in neonicotinoid treated bees.


Author(s):  
Andrea Hahnefeld ◽  
Thorsten Sukale ◽  
Elena Weigand ◽  
Verena Dudek ◽  
Katharina Münch ◽  
...  

AbstractAs IQ tests are commonly used as key assessment method, we address the question whether our commonly used standardized IQ tests are appropriate for children from families of diverse cultures and different educational levels in a refugee population. We examined 109 refugee children aged 3–7 years (M = 5.10 years, SD = 1.25) with the “Kaufman Assessment Battery for Children “ (KABC-II; Kaufmann & Kaufmann, 2015) on a language-free scale (Scale of Intellectual Functioning, SIF) and learning performance (subtest Atlantis). With a non-verbal IQ of 81.5 (SD = 18.01), the population mean of the refugee children is more than one standard deviation lower than the mean of the German norm population. Standardized scores follow the normal distribution and are not correlated to any of the assessed markers of adversity (flight duration, time spent in Germany, child PTSD in parent rating, parental symptom load, and parental education level).Conclusion: The interpretation of IQ test results for refugee children should be done cautiously as results may underestimate their cognitive capacity. Environmental factors, such as high illiteracy among parents in this study, the lack of institutional education of children and high lifetime stress, may explain our findings.Trial registration: DRKS00021150. What is Known:• There is a high pervasiveness for the use of standardized IQ tests in the German health and education system to determine eligibility for special education and social services. What is New:• Refugee children score significantly lower than German children in a language-free IQ test. As results are normally distributed and not correlated to any of the assessed markers of adversity, the low scores in the refugee group might be due to missing formal education.


Drones ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 127
Author(s):  
Wamiq Raza ◽  
Anas Osman ◽  
Francesco Ferrini ◽  
Francesco De Natale

In recent years, the proliferation of unmanned aerial vehicles (UAVs) has increased dramatically. UAVs can accomplish complex or dangerous tasks in a reliable and cost-effective way but are still limited by power consumption problems, which pose serious constraints on the flight duration and completion of energy-demanding tasks. The possibility of providing UAVs with advanced decision-making capabilities in an energy-effective way would be extremely beneficial. In this paper, we propose a practical solution to this problem that exploits deep learning on the edge. The developed system integrates an OpenMV microcontroller into a DJI Tello Micro Aerial Vehicle (MAV). The microcontroller hosts a set of machine learning-enabled inference tools that cooperate to control the navigation of the drone and complete a given mission objective. The goal of this approach is to leverage the new opportunistic features of TinyML through OpenMV including offline inference, low latency, energy efficiency, and data security. The approach is successfully validated on a practical application consisting of the onboard detection of people wearing protection masks in a crowded environment.


Author(s):  
Weixiang Lv ◽  
Xingfu Jiang ◽  
Xiujie Chen ◽  
Yunxia Cheng ◽  
Jixing Xia ◽  
...  

Understanding how species that follow different life-history strategies respond to stressful temperature can be essential to efficient treatments against agricultural pests. Here we focus on how the development and reproduction of C. medinalis is influenced by exposure to different rearing temperatures in the immature stage. We found that low (18 or 22 °C) or high (30 and 34 °C) rearing temperatures negatively affected the immature development and flight performance compared to the normal temperature 26 °C, with higher larval and pupal mortality, lower pupation and eclosion rates and shorter flight duration and distance. Low rearing temperatures significantly slowed down the immature process, but accelerated adult reproduction. However, high rearing temperatures had the opposite impacts. Interestingly, the flight of adults with un-mature rearing low temperatures (18 and 22 °C) significantly decreased their lifetime fecundity and mating frequency, but increased pre-oviposition period of females compared to the control; On contrast, high rearing temperatures (30 and 34 °C) significantly accelerated onset of oviposition and enhanced synchrony of spawning. These results indicate high rearing temperatures in the immature stage are more likely to trigger the onset of migration, but low rearing temperatures induces adults to have a greater resident propensity with stronger reproductive ability.


2021 ◽  
Vol 34 ◽  
pp. 21-33
Author(s):  
Samarth S. Prabhu ◽  
A .Vishal Kumar ◽  
Rajkumar Murugesan ◽  
Jayit Saha ◽  
Ishita Dasgupta

Farmers are facing the VUCA environment (volatile, uncertain, complex and ambiguous) and data indicating the contribution of farming to India's GDP has come down from 52% to 18% between 1951 and 2018, which is alarming. At this juncture, developing countries like India, where over 70% of the rural people depend upon the agriculture fields, adoption of disruptive technology (creative destruction) becomes the need of the hour, to enhance the crop yield and quality. Weeds are one of the major issues which severely affect the crop output. Unmanned Aerial Vehicle (UAV) or drone is recommended, to address the problem. Globally, the market for agriculture drones to move from $1.3 billion to $ 6.52 billion by 2026. Globally agriculture is the second largest industry after construction in terms of drone adoption. But Indian farmers have difficulty in adopting (or) procuring UAV's, as the size of their farm is small, income is very less. Other problems associated with the adoption of UAV include knowledge transfer and training to farmers, service support and maintenance cost. DaaS (Drone as a service) model is proposed, for rural areas. This paper aims to focus on weed management by providing a safer and cost-effective solution. By integrating technologies like visible light (VIS), near-infrared (NIR) light on an Unmanned Ariel Vehicle along with a precise sprayer and a weed detection system backed up by a lithium-ion battery (for longer flight duration), can help the process of spraying weedicide efficiently. The accuracy of the tested model is 92.6% for far away detection module and 95.4 for close range detection. UAV's with sprayer protects the farmer and consumers from odour and side effects.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255559
Author(s):  
Geison P. Mesquita ◽  
José Domingo Rodríguez-Teijeiro ◽  
Rodrigo Rocha de Oliveira ◽  
Margarita Mulero-Pázmány

Despite the proved usefulness of drones in biodiversity studies, acquisition costs and difficulties in operating, maintaining and repairing these systems constrain their integration in conservation projects, particularly for low-income countries. Here we present the steps necessary to build a low-cost fixed-wing drone for environmental applications in large areas, along with instructions to increase the reliability of the system and testing its performance. Inspired by DIY (Do It Yourself) and open source models, this work prioritizes simplicity and accounts for cost-benefit for the researcher. The DIY fixed-wing drone developed has electric propulsion, can perform pre-programmed flight, can carry up to 500 g payload capacity with 65 minutes flight duration and flies at a maximum distance of 20 km. It is equipped with a RGB (Red, Green and Blue) sensor capable of obtaining 2.8 cm per pixel Ground Sample Distance (GSD) resolution at a constant altitude of 100 m above ground level (AGL). The total cost was $995 which is substantially less than the average value of similar commercial drones used in biodiversity studies. We performed 12 flight tests in auto mode using the developed model in protected areas in Brazil, obtaining RGB images that allowed us to identify deforestation spots smaller than 5 m2 and medium-sized animals. Building DIY drones requires some technical knowledge and demands more time than buying a commercial ready-to-fly system, but as proved here, it can be less expensive, which is often crucial in conservation projects.


2021 ◽  
Vol 13 (16) ◽  
pp. 8916
Author(s):  
Tin H. Ho ◽  
Dat T. Nguyen ◽  
Thanh Ngo ◽  
Tu D. Q. Le

Price competition has been a growing concern of worldwide researchers and managers. In the aviation market, especially with the help from e-commerce platforms such as Expedia, TripAdvisor, and SkyScanner, airfares are now available to customers in the easiest and quickest way. It thus allows airlines to match their fares immediately and simultaneously upon any changes of their rivals, given that customer’ choices are made with regard to their incomes. This study provides a dataset on domestic airfares in New Zealand that could be useful for future studies in the fields of marketing, business and economics, transportation and aviation, or management. The dataset covers 12 trunk routes and 40 secondary routes in New Zealand from 19 September 2019 to 18 December 2019, a total of 90 days. It provides a rich dataset of more than 162,000 observations regarding the airfare, departure time, arrival time, flight duration, airline, departure airport, arrival airport, transiting airport, and so on. There are possibilities to extend the dataset (e.g., in terms of flying distance, airport characteristics, and airline characteristics) to make it be valuable for future study.


2021 ◽  
Vol 8 (8) ◽  
pp. 211072
Author(s):  
Per Henningsson

Animals flying in the wild often show remarkable abilities to negotiate obstacles and narrow openings in complex environments. Impressive as these abilities are, this must result in costs in terms of impaired flight performance. In this study, I used a budgerigar as a model for studying these costs. The bird was filmed in stereo when flying through a wide range of gap widths from well above wingspan down to a mere 1/4 of wingspan. Three-dimensional flight trajectories were acquired and speed, wingbeat frequency and accelerations/decelerations were calculated. The bird used two different wing postures to get through the gaps and could use very small safety margins (down to 6 mm on either side) but preferred to use larger when gap width allowed. When gaps were smaller than wingspan, flight speed was reduced with reducing gap width down to half for the smallest and wingbeat frequency was increased. I conclude that flying through gaps potentially comes with multiple types of cost to a bird of which the main may be: (i) reduced flight speed increases the flight duration and hence the energy consumption to get from point A to B , (ii) the underlying U-shaped speed to power relationship means further cost from reduced flight speed, and associated with it (iii) elevated wingbeat frequency includes a third direct cost.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Göksel Keskin ◽  
Seyhun Durmus ◽  
Muharrem Karakaya ◽  
Melih Cemal Kushan

Purpose Increasing endurance was a very appropriate subject for the biomimetic approach. The study aims to design and manufacture a long-lasting mini unmanned aerial vehicle (UAV) using active gliding and soaring. Design/methodology/approach The endurance of mini UAVs is limited by battery or fuel capacity, and it is not always possible to increase these energy sources due to the fuselage size. Long endurance aircraft are required in various areas such as silent environment and traffic monitoring or search and rescue. Literature research on bird flight performance conducted to determine design parameters. These parameters are used in the theoretical design of the UAV for optimization. Computational fluid dynamics simulation and flight tests of the UAV performed to figure out the success of the design. Findings For a mini UAV to be produced in this class, it has been observed that it is more accurate to examine birds instead of gliders due to the size similarity. The UAV design reaches a 27.5 L/D (Glide ratio) ratio in the theoretical approach. However, flight results approved max L/D ratio is around 25 at the sea level. This flight performance is enough to outperform in glide ratio of Wandering albatrosses. Practical implications Sailplanes are known as sport aircraft. However, recent projects focus on glider designs due to fuel efficiency and silent tracking. Stemme S-14 that carries a high-resolution camera is one of the examples of these projects. The unmanned glider design can lead to these implications in the UAVs at least during the stand-by period in the air. Thanks to low weight, UAVs do not require strong thermals, which allows flying almost all over the world. Originality/value Researchers generally focus on increasing the battery capacity or the performance of the UAV. However, this study’s concentration is to increase the flight duration of the UAV by using geographical currents. For this purpose, taking advantage of bird morphology is quite a new topic. Also, glider type designs are rarely found in the field.


Author(s):  
Roman Kalvin ◽  
Juntakan Taweekun ◽  
Muhammad Waqas Mustafa ◽  
Saba Arif

The aim of this research is performing the Computational Fluid Dynamics (CFD) analysis of 81mm Mortar Shell (French Design). The analysis is performed using ANSYS Fluent Software on three different Mach numbers (0.72, 0.76, and 0.84) and results are compared with existing design of 81mm HE M57D A2 Mortar. The drag coefficient of new modified design is found to be less than the existing model. The range of mortar shell is increased by 271 meters because of low drag coefficient with 5.96% percent increase in range and 15.73% decrease in drag coefficient value. Parabolic type; light weighted material fuze casing applied over the existing fuze will result in increase in aerodynamics, range enhancement and drag coefficient reduction. Weight optimization by using lighter material for mortar components and increasing the muzzle velocity can also increase flight duration of the projectile and increase its range. The analysis on 81mm Mortar Shell is a part of range enhancement study to overcome the short fall in required range of mortar shells.


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