Intraoperative interaction modeling between surgical instruments and soft tissues in neurosurgery based on energy functions.

A physical model of soft tissue that provides realistic and real-time haptic and visual feedback is crucial for neurosurgical procedures. This paper investigates the interaction between surgical instruments and soft brain tissue, proposing a soft tissue deformation simulation method based on the principle of energy minimization and constrained energy function. The model includes a permanent deformation energy function induced by friction and a volume preservation energy function to more accurately depict tissue response during procedures such as resection of convex meningiomas and evacuation of intracerebral hematomas.

"The children of the Sun and Moon are the gardens"-How people, plants, and a living Sun shape life on Tanna, Vanuatu.

Based on original ethnographic and ethnobotanical research, we share how in the cosmology of Tanna, an island in Vanuatu's southernmost province of Tafea, the Sun is viewed as a living, interactive being. Our initial interviews explored knowledge and beliefs concerning individual plant species, then subsequent follow-up interviews further explored topics that emerged therefrom. The results of these interviews are a series of oral narratives of the mytho-historical past involving the Sun, and the description of contemporary practices which are influenced by the Sun.