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Evidence regarding the benefits of an instructor's deictic gestures in video lectures on adults' learning may not necessarily be reflective of their effect on children's learning. Furthermore, there is a lack evidence regarding how deictic gestures specifically affect learners' learning process. Based in cognitive load theory, with consideration of the signaling principle and embodiment principle in multimedia learning, the present study sought to determine whether an instructor's deictic gestures affected young adults' and children's learning from video lectures differently. Participants consisted of 60 college students as the young adults sample and 63 pupils as the children sample. Each participant viewed one of two video lectures, either with or without the instructor using deictic gestures. During the experiment, participants' eye movements, prior knowledge, learning process, and learning performance were recorded and measured. The results of nonparametric tests showed that when the instructor used deictic gestures, the children paid more attention to the video content while the young adults reported a higher learning experience. Both groups demonstrated improved learning performance, regardless of age. Our findings highlight the fact that young adults and children do learn differently from video lectures with an instructor using deictic gestures. Furthermore, our findings contribute to understandings regarding the design of video lectures and video-based learning, specifically, that if an instructor is presenting the content in video lectures, they should be encouraged to use deictic gestures to improve students' learning.

In this paper, a kind of self-curable unsaturated polyester PGA-UP with vinyl groups on the end of molecule chains was synthesized through esterification reaction of glycidol with acrylic acid. The self-curable function of unsaturated polyester was put forward as a new solution to air pollution problems caused by the cross-linking monomer’s volatilization in unsaturated polyesters (UP) industry. The synthetic method, reaction process, molecular structure and self-curing properties were studied. Investigation demonstrates that the unsaturated polyester resin PGA-UP could be synthesized through a two-step process and the liquid product was a mixed outcome of different extent esterification. The unsaturated polyester resin could be self-cured through the free radical reaction of vinyl groups on the end of the molecules when they were initiated by 1% benzoyl peroxide (BPO) at 80°C for 1 hours and 120°C for 2 hours with no cross-linking monomers. The intension strength of the self-cured PGA-UP is 13.5Mpa, close to the 15.6MPa of an usual unsaturated polyester S-UP made in our lab. The self-curable PGA-UP presents good potential application and the research will contribute to improve the environmental problems caused by volatile of cross-linking monomers in unsaturated polyester applications. 1H-NMR and FT-IR were used to characterize.

This study tested the mutual effects of the instructor's eye gaze and facial expression on students' eye movements (i.e. first fixation time to the slides, percentage dwell time on the slides, and percentage dwell time on the instructor), parasocial interaction, and learning performance in pre-recorded video lectures. Students (N = 118 undergraduate and graduate students) were assigned to watch one of four videos in a 2 (gaze: direct, guided) × 2 (facial expression: surprised, neutral) between-groups design. Contrary to our hypotheses, eye movement data showed that students who watched the video lecture with the instructor's guided gaze and surprised face showed longer first fixation time to the slides and lower dwell time on the slides; these students also had lower learning scores. Instructor eye gaze and facial expression did not influence students' ratings of parasocial interaction. Our results suggest that in reference to social cues during video lectures with slides, "more" is not necessarily "better." The findings have practical implications for designing pre-recorded slide-based video lectures: An instructor is cautioned against using multiple social cues simultaneously, especially in video lectures in which the instructor and the visual learning materials compete for students' attention.

Language learning has long been a topic of interest, and instructional videos which allow students to learn anywhere and anytime have become an important language learning tool. However, the emotional characteristics of both instructors and students, which have the potential to influence students' second language learning from instructional videos, have yet to be fully explored. The current study investigated the interaction effects of an instructor's emotions (positive vs. negative vs. neutral) and students' emotional intelligence (low vs. high) on students' second language vocabulary learning from instructional videos with consideration of attention paid to the learning material (i.e., average fixation time, referring to the duration of each fixation on the learning material), learning experience (i.e., motivation, engagement, interaction), and learning performance (both immediate and delayed). Results showed that (1) only the interaction effect on attention was verified, and that (2) students with high emotional intelligence showed a larger average fixation time in the positive condition than in the negative condition, while (3) students with low emotional intelligence showed a smaller average fixation time in the neutral condition than in the negative condition. Furthermore, the results verified the benefits of the instructor's positive emotion on students' motivation, interaction, and immediate performance. Our findings shine a light onto the influence of an instructor's emotions and students' emotional intelligence on second language learning, and provide practical implications for the design of instructional videos and second language learning.

This study tested the interaction effect of the instructor's eye gaze (direct gaze vs. averted gaze) and facial expression (happy face vs. neutral face) on students' attention and learning performance in slide-based video lectures. University students (N = 120) participated in the experiment in a laboratory setting. The results of ANOVAs showed that students in the conditions that included the instructor's direct gaze paid greater attention to the instructor's face and paid less attention to the video lecture slides. However, direct gaze predicted better learning when the instructor had a happy facial expression. Our results suggest that the effects of an instructor's eye gaze are modulated by her facial expression in this educational context. The findings have practical implications for designing slide-based video lectures: an instructor is encouraged to look straight towards the camera with a happy expression.

Metabolic dysregulation is a key driver of cellular senescence, contributing to the progression of systemic aging. The heterogeneity of senescent cells and their metabolic shifts are complex and unexplored. A microfluidic SlipChip integrated with surface‐enhanced Raman spectroscopy (SERS), termed SlipChip‐SERS, is developed for single‐cell metabolism analysis. This SlipChip‐SERS enables compartmentalization of single cells, parallel delivery of saponin and nanoparticles to release intracellular metabolites and to realize SERS detection with simple slipping operations. Analysis of different cancer cell lines using SlipChip‐SERS demonstrated its capability for sensitive and multiplexed metabolic profiling of individual cells. When applied to human primary fibroblasts of different ages, it identified 12 differential metabolites, with spermine validated as a potent inducer of cellular senescence. Prolonged exposure to spermine can induce a classic senescence phenotype, such as increased senescence‐associated β‐glactosidase activity, elevated expression of senescence‐related genes and reduced LMNB1 levels. Additionally, the senescence‐inducing capacity of spermine in HUVECs and WRL‐68 cells is confirmed, and exogenous spermine treatment increased the accumulation and release of H2O2. Overall, a novel SlipChip‐SERS system is developed for single‐cell metabolic analysis, revealing spermine as a potential inducer of senescence across multiple cell types, which may offer new strategies for addressing ageing and ageing‐related diseases. [ABSTRACT FROM AUTHOR]

An instructor's gestures have an effect not only on students' learning but also on teaching itself. In two experiments, this study tested whether instructors' use of gestures while recording video lectures affected their teaching performance, stress, and cognitive load. In Experiment 1, participants recorded video lectures with gestures or without gestures. As hypothesized, t tests showed that participants in the gestures condition had better teaching performance and lower cognitive load than participants in the no-gestures condition, whereas there was no effect on stress level. In Experiment 2, participants recorded video lectures with either pointing gestures or representational gestures. The t tests indicated that participants in the pointing gestures condition showed better teaching performance and experienced lower stress than those in the representational gestures condition, but there was no difference in cognitive load. Overall, our findings suggest that in the new educational environment of video lectures, instructors should consider using gestures, especially pointing gestures, to improve their teaching and their experience of teaching.