[Implement of mixed reality navigation based on multimodal imaging in the resection of intracranial eloquent lesions].

Objective: To examine the clinical feasibility of mixed reality navigation (MRN) technology based on multimodal imaging for the resection of intracranial eloquent lesions. Methods: Fifteen patients with intracranial eloquent lesions admitted to the Department of Neurosurgery, the First Medical Center, People's Liberation Army General Hospital from September 2020 to September 2021 were retrospectively enrolled. There were 7 males and 8 females, aged (50±16) years (range: 16 to 70 years). Postoperative pathological diagnosis included meningioma (n=7), metastatic carcinoma (n=3), cavernous hemangioma, glioma, ependymoma, aneurysmal changes and lymphoma (n=1, respectively). The open-source software was used to perform the three-dimensional visualization of preoperative images, and the self-developed MRN system was used to perform the fusion and interaction of multimodal images, so as to formulate the surgical plan and avoid damaging the eloquent white matter fiber tracts. Traditional navigation, intraoperative ultrasound and fluorescein sodium angiography were used to determine the extent of lesion resection. The intraoperative conditions of MRN-assisted surgery were analyzed, and the setup time and localization error of MRN system were measured. The changes of postoperative neurological function were recorded. Results: MRN based on multimodal imaging was achieved in all patients. The MRN system setup time (M(IQR)) was 36 (12) minutes (range: 20 to 44 minutes), and the localization error was 3.2 (2.0) mm (range: 2.6 to 6.7 mm). The reliability of eloquent white matter fiber tracts localization based on MRN was rated as "excellent" in 11 cases, "medium" in 3 cases, and "poor" in 1 case. There were no perioperative death and no new impairment in motor, language, or visual functions after operation. Transient limb numbness occurred in 1 patient after operation, and recovered to the preoperative state in 2 weeks after operation. Conclusion: The MRN system based on multimodal imaging can improve the surgical accuracy and safety, and reduce the incidence of iatrogenic neurological dysfunction.

How the environment shapes animal signals: a test of the acoustic adaptation hypothesis in frogs.

Long-distance acoustic signals are widely used in animal communication systems and, in many cases, are essential for reproduction. The acoustic adaptation hypothesis (AAH) implies that acoustic signals should be selected for further transmission and better content integrity under the acoustic constraints of the habitat in which they are produced. In this study, we test predictions derived from the AAH in frogs. Specifically, we focus on the difference between torrent frogs and frogs calling in less noisy habitats. Torrents produce sounds that can mask frog vocalizations and constitute a major acoustic constraint on call evolution. We combine data collected in the field, material from scientific collections and the literature for a total of 79 primarily Asian species, of the families Ranidae, Rhacophoridae, Dicroglossidae and Microhylidae. Using phylogenetic comparative methods and including morphological and environmental potential confounding factors, we investigate putatively adaptive call features in torrent frogs. We use broad habitat categories as well as fine-scale habitat measurements and test their correlation with six call characteristics. We find mixed support for the AAH. Spectral features of torrent frog calls are different from those of frogs calling in other habitats and are related to ambient noise levels, as predicted by the AAH. However, temporal call features do not seem to be shaped by the frogs' calling habitats. Our results underline both the complexity of call evolution and the need to consider multiple factors when investigating this issue.