Mobile Edge Computing (MEC) has been widely employed to support various Internet of Things (IoT) and mobile applications. By leveraging the advantages of easily deployed and flexibility of Unmanned Aerial Vehicle (UAV), one of MEC primary functions is employing UAVs equipped with MEC servers to provide computation supports for the offloaded tasks by mobile users in temporally hotspot areas or some emergent scenarios, such as sports game areas or destroyed by natural disaster areas. Despite the numerous advantages of UAV carried with a MEC server, it is restricted by its limited computation resources and sensitive energy consumption. Moreover, due to the complexity of UAV-assisted MEC system, its computational resource optimization and energy consumption optimization can not be achieved well in traditional optimization methods. Furthermore, the computational cost of the MEC system optimization is often exponentially growing with the increase of the MEC servers and mobile users. Therefore, it is considerably challenging to control the UAV positions and schedule the task offloading ratio. In this paper, we proposed a novel Deep Reinforcement Learning (DRL) method to optimize UAV trajectory controlling and users’ offloaded task ratio scheduling and improve the performance of the UAV-assisted MEC system. We maximized the system stability and minimized the energy consumption and computation latency of UAV-assisted the MEC system. The simulation results show that the proposed method outperforms existing work and has better scalability.

This study aimed to investigate alterations in the activity and sleep of Drosophila melanogaster under simulated microgravity, which was implemented through the random positioning machine, while different light conditions (normal photoperiod and constant dark) were set. Fruit flies of different strains and sexes were treated for 3 days, and activity and sleep were monitored using the Drosophila Activity Monitoring System. After 3 days of treatment, fruit flies were sampled to detect the relative expression levels of the major clock genes and some neurotransmitter-related genes. The results showed that for the normal photoperiod (LD) condition, the activity increased and sleep decreased under simulated microgravity, while for the constant dark (DD) condition, the activity and sleep rhythms appeared disordered and the activity increased, thus decreasing the likelihood of waking up during the day. Light conditions, strains, and sexes, individually or in combination, had impacts on the simulated microgravity effects on behaviors. The clock genes and neurotransmitter-related genes had different degrees of response among sexes and strains, although the overall changes were slight. The results indicated that the normal photoperiod could ease the effects of simulated microgravity on fruit flies’ activity and sleep and possible unidentified pathways involved in the regulatory mechanism need further exploration. This study is expected to provide ideas and references for studying the effects of microgravity on space life science.

Objectives: This study planned to determine the biological effects associated with ZnFe₂O₄-NPs exposure using Drosophila melanogaster as an in vivo model. Methods: ZnFe₂O₄-NPs were hydrothermally synthesized, and the development of offspring flies were evaluated via dietary exposure to different doses of ZnFe₂O₄-NPs (0, 200, 400, 600 μg/mL). Rhythmic behaviors of parent male flies were monitored. Results: Internalization of ZnFe₂O₄-NPs through the intestinal barrier occurred. Oral intake of ZnFe₂O₄-NPs decreased the eclosed adult numbers and perturbed the insect developmental process. In male flies, significant upregulation of HSPs and Turandot family genes was detected, accompanied by ROS reduction and suppressed antioxidant defense responses, and exposure of ZnFe₂O₄-NPs disrupted sleep patterns of males, including a reduction in sleep duration and aggravation of sleep fragmentation. Suppressed activity levels were also found after ZnFe₂O₄-NPs exposure. Significant increased expressions of circadian genes (Clk and Cyc) were detected, alongside elevation of neurotransmitter levels and related gene expressions. Conclusions: Overall, ZnFe₂O₄-NPs can perturb development process via inducing heat shock and detoxification response, and disrupted rhythmic behaviors may be attributed to elevation of neurotransmitter levels and upregulated gene expressions of circadian genes. Our findings may offer valuable insights for evaluating ecological risks of metal-based nanoparticles and suggest potential applications in developing novel pest management strategies by utilizing insect behavioral and physiological responses to nanomaterials.

The widespread implementation of fifth-generation (5 G) technology has raised concerns regarding its impact on biosafety. This study aims to uncover metabolic alterations in Drosophila melanogaster in response to electromagnetic radiation through metabolomics under 3.5 GHz radiofrequency electromagnetic fields (RF-EMF) conditions. Newborn male flies were continuously exposed to 3.5 GHz RF-EMF at intensities of 0.1 W/m², 1 W/m², and 10 W/m² throughout their entire life cycle under 24-hour constant darkness. Metabolomic analysis was performed on Drosophila samples after long-term exposure. The results indicate that long-term exposure to RF-EMF leads to disruptions in four metabolic pathways - alanine, aspartate and glutamate metabolism, tryptophan metabolism, ascorbate and aldehyde metabolism, and purine metabolism - as well as 34 differential metabolites across various power density in Drosophila melanogaster. Notably, the most significant metabolites (GABA, glucose-6-phosphate, AMP, N-formylglycinamide nucleotide, LPC, and MG) exhibited high sensitivity to RF-EMF showing significant decreases. The suggests that long-term exposure to electromagnetic wave treatment may reduce the overall metabolic levels in fruit fly. These findings provide valuable insights into the metabolic disturbance induced by RF-EMF and enhance our understanding of the potential health effects associated with 5 G radiation.