Fitts' law on the flight deck: evaluating touchscreens for aircraft tasks in actual flight scenarios.

This research investigated the effects of an abnormal flight environment using touch-based navigation displays (TNDs). Fitts' law was used to compare the performance of TNDs with control display units (CDUs) and mode control panel (MCPs) under three different flight scenarios (normal, turbulence and startled). A within-subjects design involving 15 male participants was used. Data were collected in respect to accuracy, movement time, subjective feelings, choices and comments. The results showed that under abnormal conditions, TNDs showed worse operation performance and stability than CDUs and MCPs; however, it was easy to learn from TNDs, and they provided a good user experience. Moreover, this research demonstrated the application of Fitts' law to describe pilot behaviours in interactive flight devices, particularly for tasks involving real flight operations. TND designs for aviation could be developed based on these findings to improve flight crew performance when using new technology.Practitioner summary: This research built a Fitts' law model to evaluate the performance of aircraft cockpit touchscreens under normal, turbulence and startled scenarios. We compared the different touchscreens (TNDs) with other traditional interactive devices, such as CDUs and MCPs. The results have implications for the design of aircraft cockpit touchscreens and define the task scenario. Furthermore, the results contribute to the development of scenes utilising Fitts' law.

Understanding trust calibration in automated driving: the effect of time, personality, and system warning design.

Under the human-automation codriving future, dynamic trust should be considered. This paper explored how trust changes over time and how multiple factors (time, trust propensity, neuroticism, and takeover warning design) calibrate trust together. We launched two driving simulator experiments to measure drivers' trust before, during, and after the experiment under takeover scenarios. The results showed that trust in automation increased during short-term interactions and dropped after four months, which is still higher than pre-experiment trust. Initial trust and trust propensity had a stable impact on trust. Drivers trusted the system more with the two-stage (MR + TOR) warning design than the one-stage (TOR). Neuroticism had a significant effect on the countdown compared with the content warning.Practitioner summary: The results provide new data and knowledge for trust calibration in the takeover scenario. The findings can help design a more reasonable automated driving system in long-term human-automation interactions.

Effect of methomyl on sex steroid hormone and vitellogenin levels in serum of male tilapia (Oreochromis niloticus) and recovery pattern.

Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 µg/L for 30 days, then transferred to methomyl-free water for 18 days. E2 , T, 11-KTand VTG in serum were examined. There were no significant changes in all the parameters in serum of tilapia exposed to 0.2 µg/L and 2 µg/L methomyl compared to the control. However, 20 µg/L and 200 µg/L have the potential to disrupt the endocrine system of male tilapia, as shown by its ability to increase VTG and E2 and decrease T and 11-KT in serum. Thus it would appear the no observed adverse effect level for sexual steroid hormones of methomyl is lower than 2 µg/L. Recovery data showed that the effects produced by 20µg/L were reversible but not at 200µg/L. Furthermore, the sensitivity of above parameters to methomyl followed the order of VTG>E2 >11-KT>T>GSI, suggesting VTG being the better biomarkers.

Characterizing bacterial communities in tilapia pond surface sediment and their responses to pond differences and temporal variations.

Bacterial community compositions in the surface sediment of tilapia ponds and their responses to pond characteristics or seasonal variations were investigated. For that, three ponds with different stocking densities were selected to collect the samples. And the method of Illumina high-throughput sequencing was used to amplify the bacterial 16S rRNA genes. A total of 662, 876 valid reads and 5649 operational taxonomic units were obtained. Further analysis showed that the dominant phyla in all three ponds were Proteobacteria, Bacteroidetes, Chloroflexi, and Acidobacteria. The phyla Planctomycetes, Firmicutes, Chlorobi, and Spirochaetae were also relatively abundant. Among the eight phyla, the abundances of only Proteobacteria, Bacteroidetes, Firmicutes, and Spirochaetae were affected by seasonal variations, while seven of these (with the exception of Acidobacteria) were affected by pond differences. A comprehensive analysis of the richness and diversity of the bacterial 16S rRNA gene, and of the similarity in bacterial community composition in sediment also showed that the communities in tilapia pond sediment were shaped more by pond differences than by seasonal variations. Linear discriminant analysis further indicated that the influences of pond characteristics on sediment bacterial communities might be related to feed coefficients and stocking densities of genetically improved farmed tilapia (GIFT).

Responses of glutathione-related antioxidant defense system in serum of Nile tilapia (Oreochromis niloticus) exposed to sublethal concentration of methomyl and recovery pattern.

Tilapia were exposed to sublethal concentrations of 0, 0.2, 2, 20, or 200 µg/L for 30 days, and then transferred to methomyl-free water for 18 days. GST, GPx, GR, GSH, and GSSG in tilapia serum were examined at 0, 6, 12, 18, 24, and 30 days after methomyl exposure and at 18 days after transferring to methomyl-free water. There were no significant changes in antioxidants activities and contents in serum of tilapia exposed to 0.2 µg/L. Significant increases in GST, GR, GPx, and GSSG accompanied by a decrease in GSH were observed following methomyl exposure to 2, 20, or 200 µg/L, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 µg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 µg/L were reversible but not at the higher 200 µg/L concentration.

Effects of driving style on takeover performance during automated driving: Under the influence of warning system factors.

Driving style has been proposed to be a critical factor in automated driving. However, the role of driving style in the process of taking over during automated driving needs further investigation. The main purpose of this study was to investigate the influence of driving style on takeover performance under the influence of warning system factors. In addition, this study also explored whether the impact of driving style on reaction time varies over time and the role of driving style on a comprehensive takeover quality indicator. Two driving simulation experiments with different takeover request (TOR) designs were conducted. In experiment 1, content warning information was provided in the TOR with different warning stage designs; in experiment 2, countdown warning information was provided in the TOR with different warning stage designs. Sixty-four participants (32 for experiment 1 and 32 for experiment 2) were classified into two groups based on their driving style (i.e., aggressive, or defensive) using the Chinese version of the Multidimensional Driving Style Inventory (the brief MDSI-C). The results suggested that drivers' driving style had significant effects on takeover performance, but the effects were influenced by warning system designs. Specifically, defensive participants performed better takeover performance, i.e., shorter reaction time and cautious vehicle control behaviors, than aggressive participants in most warning conditions. The content and countdown warning information and warning stage design affected the roles of driving style on takeover performance: 1) compared to the one-stage warning design, the two-stage warning design significantly shortened the reaction time of the participants with different driving styles, 2) compared to the countdown warning information design, the design of content warning information can shorten the reaction time of aggressive participants and lengthen the reaction time of defensive participants in the two-stage warning conditions, and 3) compared to the content warning information design, countdown warning information can improve the safe takeover performance of defensive participants. This study provides a better understanding of the role of driving style on takeover performance, and driving style should be considered when designing warning systems for autonomous vehicles.

Effect of 17α-methyltestosterone (MT) on oxidation stress in the liver of juvenile GIFT tilapia, Oreochromis niloticus.

The normal dose of 17α-methyltestosterone (MT) used in fish farming was 60 mg/L, and now the analysis of residual androgens was carried out in waste water obtained from the Beijing area, which could be detected in levels ranging from 4.1 to 7.0 ng/L. For the purpose of aquatic early warning, the present study clearly demonstrated that chronic exposure by higher concentration of MT than environmental relevant concentrations could trigger oxidative stress response to juvenile tilapia by modulating hepatic antioxidant enzyme activities and gene transcription. Some antioxidative parameters (T-GSH, GSH/GSSG and MDA) were significant decreased under 0.5 mg/L MT exposure at 7 and 14 days. Some antioxidant enzymes (SOD, CAT and GST) and transcriptional changes (sod and cat) were revealed significant decreases for MT treated groups at 7 days. Total antioxidant capacity was significant increased only in 5 mg/L MT exposure groups, but GR activities were not affected all through the whole exposure period. Almost all of the antioxidant enzymatic genes detected in the present study were showed significant increments for MT exposure both at 14 and 21 days, and the genotoxicity profile of antioxidant enzymatic genes were revealed dose-dependent manner. This study presented evidence that MT could result in oxidative stress response in the early stages of GIFT tilapia.

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River.

Bacterioplankton and archaeaplankton communities play key roles in the biogeochemical processes of water, and they may be affected by many factors. In this study, we used high-throughput 16S rRNA gene sequencing to profile planktonic bacterial and archaeal community compositions in the upper section of the tidal reach in Yangtze River. We found that the predominant bacterial phyla in this river section were Proteobacteria, Firmicutes, and Actinobacteria, whereas the predominant archaeal classes were Halobacteria, Methanomicrobia, and unclassified Euryarchaeota. Additionally, the bacterial and archaeal community compositions, richnesses, functional profiles, and ordinations were affected by the spatial heterogeneity related to the concentration changes of sulphate or nitrate. Notably, the bacterial community was more sensitive than the archaeal community to changes in the spatial characteristics of this river section. These findings provide important insights into the distributions of bacterial and archaeal communities in natural water habitats.

Effects of methomyl on steroidogenic gene transcription of the hypothalamic-pituitary-gonad-liver axis in male tilapia.

Male tilapia were exposed to sub-lethal methomyl concentrations of 0, 0.2, 2, 20 or 200 µg/L for 30 d, and were subsequently cultured in methomyl-free water for 18 d. Relative transcript abundance of steroidogenic genes involved in the HPGL axis of male tilapia was examined at 30 d in the exposure test and at 18 d in the recovery test. The results revealed that low concentrations of methomyl (0.2 and 2 µg/L) did not cause significant changes in gene mRNA levels in the HPGL axis of male tilapia; thus, we considered 2 µg/L concentrations as the level that showed no apparent adverse endocrine disruption effects. However, higher concentrations of methomyl (20 and 200 µg/L) disrupted the endocrine system and caused significant increase in the levels of GnRH2, GnRH3, ERα, and ERß genes in the hypothalamus, GnRHR and FSHß genes in the pituitary, CYP19a, FSHR, and ERα genes in the testis, and VTG and ERα genes in the liver, and significantly decreased the levels of LHR, StAR, 3ß-HSD, and ARα genes in the testis and LHß gene in the pituitary, leading to changes in sex steroid hormone and vitellogenin levels in the serum and ultimately resulting in reproductive dysfunction in male tilapia. The recovery tests showed that the toxicity effect caused by 20 µg/L methomyl was reversible; however, the toxicity effect at 200 µg/L of methomyl was irreversible after 18 d. Therefore, we concluded that 200 µg/L was the threshold concentration for methomyl-induced irreversible endocrine disruption in male tilapia.

Exploration of three heterotrophic nitrifying strains from a tilapia pond for their characteristics of inorganic nitrogen use and application in aquaculture water.

Three heterotrophic nitrifying bacterial strains, HLf01, HBf01 and HHf01, were isolated from a pond where genetically improved farmed tilapia (GIFT) (Oreochromis niloticus) was intensively cultured during the annual peak breeding period. Analysis of biochemical, morphological characteristics and sequences analysis of 16S rDNA identified strains HLf01 and HBf01 as Pseudomonas sp., and strain HHf01 as Acinetobacter baumannii. Further analysis of heterotrophic nitrifying medium inorganic nitrogen used showed that most of the ammonia nitrogen was removed after 48 h. Strains HBf01 and HHf01 removed 67.9% and 76.7% of the total ammonia nitrogen after 24 h, recording the mass ratio of carbon to nitrogen used as 10.6 to 1 and 11.7 to 1, respectively. Strain HLf01 used a C:N ratio of 22.7 to 1 with a total of 43.8% ammonia nitrogen removed. In denitrifying media, strains HBf01 and HHf01 may have used nitrate and nitrite as the sole nitrogen source by strain HLf01. Generally, all the three strains used nitrogen in the order ammonia > nitrite > nitrate when all the three nitrogen forms were recorded present. Although the bacterial strains consumed dissolved organic carbon, it was limited when ammonia was the main source of nitrogen compared with other forms of inorganic nitrogen. Also, the test of the three strains on aquaculture water showed similar results of efficiency of ammonia nitrogen removal with the test of inorganic nitrogen use.