Mineralized skeletal tissues of vertebrates are an evolutionary novelty within the chordate lineage. While the progenitor cells that contribute to vertebrate skeletal tissues are known to have two embryonic origins, the mesoderm and neural crest, the evolutionary origin of their developmental process remains unclear. Using cephalochordate amphioxus as our model, we found that cells at the lateral wall of the amphioxus somite express SPARC (a crucial gene for tissue mineralization) and various collagen genes. During development, some of these cells expand medially to surround the axial structures, including the neural tube, notochord and gut, while others expand laterally and ventrally to underlie the epidermis. Eventually these cell populations are found closely associated with the collagenous matrix around the neural tube, notochord, and dorsal aorta, and also with the dense collagen sheets underneath the epidermis. Using known genetic markers for distinct vertebrate somite compartments, we showed that the lateral wall of amphioxus somite likely corresponds to the vertebrate dermomyotome and lateral plate mesoderm. Furthermore, we demonstrated a conserved role for BMP signaling pathway in somite patterning of both amphioxus and vertebrates. These results suggest that compartmentalized somites and their contribution to primitive skeletal tissues are ancient traits that date back to the chordate common ancestor. The finding of SPARC-expressing skeletal scaffold in amphioxus further supports previous hypothesis regarding SPARC gene family expansion in the elaboration of the vertebrate mineralized skeleton.

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Background Physicians and nurses often exhibit strong negative emotional and behavioral reactions when patients they care for die, and death education helps them cope with these difficulties. When implementing death education, the literature shows that experiential activities are more effective than lecturing, and progressive exposure is the best way to reduce death anxieties. This study examined the effects of coffin-lying, an activity sometimes seen in Asian cultures, on life and death attitudes of medical and nursing students. Methods During a period from 2020 to 2021, 134 medical and nursing students from a medical university in northern Taiwan voluntarily participated in this study. Among them, 53 were in the experimental group, who participated in a coffin-lying activity for nearly 3 hours, and the other 81 were in the control group. All participants filled out questionnaires 1 week before the activity (T1), 1 week after the activity (T2), and 6 ~ 11 weeks after the activity (T3). Three waves of data were analyzed by a repeated-measure multivariate analysis of variance (MANOVA). Results The effects of “love and care” and “feeling of existence” were only manifested at T2, however, the scores of “fear of death” and “death avoidance” between the experimental and control groups significantly differed at T2 and T3. In addition, there were no significant differences between the experimental and control groups in “neutral acceptance”, “approach acceptance”, or “escape acceptance”. Conclusions The coffin-lying activity based on desensitization was effective in improving “fear of death” and “death avoidance”, and the effects were sustained to 6 ~ 11 weeks. Coffin-lying is not only a well-designed activity that quickly reduces negative tendencies toward death, but it is also worth adopting by medical and nursing schools to make death education more comprehensive.

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Background Physicians and nurses often exhibit strong negative emotional and behavioral reactions when patients they care for pass away, and death education helps them cope with these difficulties. When implementing death education, the literature shows that experiential activities are more effective than lecturing, and progressive exposure is the best way to reduce death anxieties. This study examined the effects of coffin-lying, an activity sometimes seen in Asian cultures, on life and death attitudes of medical and nursing students. Methods During a period from 2020 to 2021, 134 medical and nursing students from a medical university in northern Taiwan voluntarily participated in this study. Among them, 53 were in the experimental group, who participated in a coffin-lying activity for nearly 3 hours, and the other 81 were in the control group. All participants filled out questionnaires 1 week before the activity (T1), 1 week after the activity (T2), and 6 ~ 11 weeks after the activity (T3). Three waves of data were analyzed by a repeated-measure analysis of variance (ANOVA). Results The “fear of death” and “death avoidance” between the experimental and control groups significantly differed at T2 and T3, and the effects of “love and care” and “feeling of existence” were only manifested at T2. In addition, there were no significant differences between the experimental and control groups in “natural acceptance”, “approach acceptance”, or “escape acceptance”. Conclusions The coffin-lying activity based on desensitization is effective in improving “fear of death” and “death avoidance”, and the effects were extended to 6 ~ 11 weeks. Coffin-lying is not only a well-designed activity that quickly reduces negative tendencies toward death, but it is also worth adopting by medical and nursing schools to make death education more comprehensive.