Effect of acute stress on working memory in pilots: Investigating the modulatory role of memory load.

Many practitioners, such as pilots, frequently face working memory (WM) demands under acute stress environments, while the effect of acute stress on WM has not been conclusively studied because it is moderated by a variety of factors. The current study investigated how acute stress affects pilots' WM under different memory load conditions. There are 42 pilots conducting the experiments, consisting of 21 stress group participants experiencing the Trier Social Stress Test (TSST) and 21 control group participants experiencing the controlled TSST (C-TSST). Subsequently, both groups performed N-back tasks under three memory load conditions (0-back, 1-back, and 2-back). State Anxiety Inventory (S-AI), heart rate (HR), and salivary cortisol concentrations (SCC) were collected to analyze acute stress induction. The results revealed that (1) the TSST could effectively induce acute stress with higher S-AI, HR, and SCC; (2) higher memory load reduces WM accuracy (ACC) and delays response times (RT); (3) acute stress increases WM ACC under moderate load conditions (1-back task). These results suggest that acute stress may not necessarily impair WM and even improve WM performance under certain memory load conditions. Potential mechanisms of acute stress effects on WM and alternative explanations for the modulatory role of memory load consistent with the emotion and motivation regulation theory are discussed. These findings not only provide insight into the field of acute stress and WM but are also beneficial for pilot training and the development of stress management strategies.

Lineage-specific mutation of Lmx1b provides new insights into distinct regulation of suture development in different areas of the calvaria.

The calvaria (top part of the skull) is made of pieces of bone as well as multiple soft tissue joints called sutures. The latter is crucial to the growth and morphogenesis of the skull, and thus a loss of calvarial sutures can lead to severe congenital defects in humans. During embryogenesis, the calvaria develops from the cranial mesenchyme covering the brain, which contains cells originating from the neural crest and the mesoderm. While the mechanism that patterns the cranial mesenchyme into bone and sutures is not well understood, function of Lmx1b, a gene encoding a LIM-domain homeodomain transcription factor, plays a key role in this process. In the current study, we investigated a difference in the function of Lmx1b in different parts of the calvaria using neural crest-specific and mesoderm-specific Lmx1b mutants. We found that Lmx1b was obligatory for development of the interfrontal suture and the anterior fontanel along the dorsal midline of the skull, but not for the posterior fontanel over the midbrain. Also, Lmx1b mutation in the neural crest-derived mesenchyme, but not the mesoderm-derived mesenchyme, had a non-cell autonomous effect on coronal suture development. Furthermore, overexpression of Lmx1b in the neural crest lineage had different effects on the position of the coronal suture on the apical part and the basal part. Other unexpected phenotypes of Lmx1b mutants led to an additional finding that the coronal suture and the sagittal suture are of dual embryonic origin. Together, our data reveal a remarkable level of regional specificity in regulation of calvarial development.

Effects of Temporal Characteristics on Pilots Perceiving Audiovisual Warning Signals Under Different Perceptual Loads.

Our research aimed to investigate the effectiveness of auditory, visual, and audiovisual warning signals for capturing the attention of the pilot, and how stimulus onset asynchronies (SOA) in audiovisual stimuli affect pilots perceiving the bimodal warning signals under different perceptual load conditions. In experiment 1 of the low perceptual load condition, participants discriminated the location (right vs. left) of visual targets preceded by five different types of warning signals. In experiment 2 of high perceptual load, participants completed the location task identical to a low load condition and a digit detection task in a rapid serial visual presentation (RSVP) stream. The main effect of warning signals in two experiments showed that visual and auditory cues presented simultaneously (AV) could effectively and efficiently arouse the attention of the pilots in high and low load conditions. Specifically, auditory (A), AV, and visual preceding auditory stimulus by 100 ms (VA100) increased the spatial orientation to a valid position in low load conditions. With the increase in visual perceptual load, auditory preceding the visual stimulus by 100 ms (AV100) and A warning signals had stronger spatial orientation. The results are expected to theoretically support the optimization design of the cockpit display interface, contributing to immediate flight crew awareness.

[Relative quantification of mRNA transcription of Cry1 in different tissues of sheep in oestrous cycle by real-time quantitative PCR].

Studies have shown that clock gene Cry1 may have important roles in the endocrine process of seasonal reproduction in mammals. In this study, Duolang sheep (non-seasonal reproduction sheep breed) and Chinese Merino (seasonal reproduction sheep breed) were used to determine the expression change of Cry1 in hypothalamus-pituitary-ovary axis in different stage of estrous cycle by quantitative real-time PCR. The results showed that the Cry1 mRNA was expressed in all tested tissues, in which the expression levels in pineal gland and thyroid gland were higher than in other tissues. As far as different sheep breeds were concerned, the tissue expression profiles of Cry1 at different stage of estrous cycle were broadly similar. Besides hypothalamus, the expression levels of Cry1 in ovary, uterus, pineal gland, pituitary gland, and thyroid gland were all reached to peak in proestrus. The differences of expression change extent for Cry1 in vary, uterus, pineal gland, and pituitary gland in proestrus and oestrus were significant between different sheep breeds. The results suggested that Cry1 may play roles in switching on the estrus and seasonal reproduction.

[Detection and analysis of polymorphisms of 59571364 and 59912586 loci on X chromosome in fat-tail and thin-tail sheep flocks].

In order to analyze the correlation of tail fat deposition and two SNP loci on Ovis arise chromosome X and provide a theoretical basis for using molecular assisted selection technology in further low-fat sheep breeding, the breeds with extreme differences in tail types (Altay, Small Tail Han Sheep, Hu, Chinese Merino and Suffolk) were used to detect the polymorphisms of two SNP loci on X chromosome and the haplotypes with PCR-RFLP method. The results showed that the TT genotype at 59571364 locus and GG genotype at 59912586 locus were preponderant genotypes in thin-tailed Chinese Merino and Suffolk sheep flocks, while the percentage of the two genotypes in fat-tailed (fat-rmup) Altay and Hu flocks is less than 2%. Haplotype analysis showed that CA haplotype is the main haplotype, the percentage of CA is up to 55%, and the percentage of CA and TA haplotypes together was 88.33% in Altay sheep flock. These results suggest that there are great differences in the SNP distribution of the 59571364 and 59912586 loci among different tail-typed sheep flocks, which can be used as molecular markers in high or low fat sheep breeding.

[Correlation analysis between polymorphism of the 59383635th locus on X chromosome and fat-tail trait in sheep].

Fat tail or fat rump is one of essential traits for surviving in harsh environments, and the mechanism of fat deposition and its inheritable characters in sheep are still unclear. Therefore, the 59383635th locus on X chromosome in our unpublished chip data was chosen as candidate SNP, PCR-SSCP method was used to detect genotypes in five sheep breeds which have extreme differences in tail types (Altay, Small Tail Han Sheep, Hu, Chinese Merino and Suffolk), and the mathematical model was employed to analyze the correlation between the polymorphism and the trait of fat tail or fat rump. The results in this study showed that the high frequency of allele T exists in Altay flock, and the frequency of allele C appears to be particularly high in the thin tail sheep breeds. The result of mathematical model showed that the ratio of T/C increased exponentially with the increase of phenotype score. These results suggest that there is a big difference in the SNP distribution between fat tail (rump) and thin tail sheep populations, and the SNP can be used as an ideal molecular marker in high-fat or low-fat sheep breeding. However, the biological function of the SNP remains to be further studied.

[The gene ontology and electro localization of ovine skin derived EST-SSR markers].

Abstract: In order to study the potential gene function of ovine EST-SSR markers, nine original EST of Ovine Skin Derived polymorphic EST-SSR loci, which were developed in an early study by our lab, were ontology annotated and Electro localized. The results revealed that the original ESTs of the six loci had high homology with known genes and three of them probably played an important role in wool traits. Compared with its cDNA library, 8 loci were located on chromosomes of cattle. The homology of chromosomes between cattle and sheep was estimated based on the similarity coefficients calculated by positioning markers. Additionally, NJ clustering tree was establishedto serve for electro localization of ovine EST-SSR markers. Finally, 8 EST-SSR markers were successfully positioned on ovine chromosomes. The results from this study not only provide references for further studies on genetic mapping, in silico cloning of key genes for wool traits, but also are helpful to the researchs of chromosome evolution in animal.