ABSTRACT
Coccolithophores play a significant role in marine calcium carbonate production and carbon cycles, attributing to their unique feature of producing calcareous plates, coccoliths. Coccolithophores also possess a haplo-diplontic life cycle, presenting distinct morphology types and calcification states. However, differences in nutrient acquisition strategies and mixotrophic behaviors of the two life phases remain unclear. In this study, we conducted a series of phagocytosis experiments of calcified diploid and non-calcified haploid strains of coccolithophore Gephyrocapsa huxleyi under light and dark conditions. The phagocytosis capability of each strain was examined based on characteristic fluorescent signals from ingested beads using flow cytometry and fluorescence microscopy. The results show a significantly higher phagocytosis percentage on fluorescent beads in the bacterial prey surrogates of the non-calcified haploid Gephyrocapsa huxleyi strain, than the calcified diploid strain with or without light. In addition, the non-calcified diploid cells seemingly to presented a much higher phagocytosis percentage in darkness than under light. The differential phagocytosis capacities between the calcified diploid and non-calcified haploid Gephyrocapsa huxleyi strains indicate potential distinct nutritional strategies at different coccolithophore life and calcifying stages, which may further shed light on the potential strategies that coccolithophore possesses in unfavorable environments such as twilight zones and the expanding coccolithophore niches in the natural marine environment under the climate change scenario.
ABSTRACT
Purpose: The purpose of this study is to develop and validate the Work Information Anxiety Questionnaire (WIAQ), and to report on the psychometric properties of the WIAQ. Methods: Based on the Approach-Avoidance Conflict theory, and combining previous literature reviews and open-ended interviews, initial scale items for the Work Information Anxiety Questionnaire were developed. Using 324 full-time corporate employees as subjects (Sample 1), an exploratory structural examination of work information anxiety was conducted, including item analysis, exploratory factor analysis, and network analysis. An additional 210 corporate employees were selected for formal testing (Sample 2), and the obtained data underwent structural validation, including confirmatory factor analysis, validity testing, and reliability testing. Results: The WIAQ (9 items) exhibited a two-factor structure of reception anxiety and missing out anxiety, with a cumulative variance contribution rate of 67.56%. The confirmatory factor model showed good model fit, with cross-group and cross-measurement stability. The Cronbach's α of the WIAQ was 0.899, and the McDonald's ω of the two factors were 0.906 and 0.831 respectively. The WIAQ demonstrated good criterion-related validity with the SAS and DASS. Conclusion: The factor structure of the WIAQ is clear, and its reliability and validity indicators meet psychometric requirements. It can serve as an effective tool for measuring work information anxiety.
