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In the first 2 decades of the twenty-first century, American black bear (Ursus americanus) populations rebounded with range expansions into areas where the species was previously extirpated. While there are a number of factors that limit range expansion, habitat quality and availability are among the most important. Such factors may be particularly important in western Nevada, USA, at the transition zone of the Sierra Nevada and the Great Basin Desert. We deployed a multifaceted data collection system including motion-sensitive cameras, noninvasive hair sampling and genotyping, and global positioning system (GPS) tracking. We analyzed data using spatial capture-recapture to estimate population density and dynamic occupancy models to estimate habitat use. Black bear habitat use and density were substantially higher in the Sierra Nevada than the Great Basin Desert and had strong positive relationships with the presence of conifer land cover in the transition zone. The average black bear density was >4 times higher in the mixed-conifer forests of the Sierra Nevada (12.4 bears/100 km 2 ) than in desert mountain ranges with piñon (Pinus monophylla)-juniper (Juniperus spp.) woodland (2.7 bears/100 km 2 ). The low-elevation shrub and grassland portions of the study area had even lower estimated black bear density (0.6 bears/100 km 2 ) and probability of use (0.03, 95% CI = 0.00-0.09). Across these spatially variable configurations in black bear density, we estimated the population size to be

Extracellular vesicles (EVs), detectable in all bodily fluids, mediate intercellular communication by transporting molecules between cells. The capacity of EVs to transport molecules between distant organs has drawn interest for clinical applications in diagnostics and therapeutics. Although EVs hold potential for nucleic-acid-based and other molecular therapeutics, the lack of standardized technologies, including isolation, characterization, and storage, leaves many challenges for clinical applications, potentially resulting in misinterpretation of crucial findings. Previously, several groups demonstrated the problems of commonly used storage methods that distort EV integrity. This work aims to evaluate the process to optimize the storage conditions of EVs and then characterize them according to the experimental conditions and the models used previously. Our study reports a highly efficient EV storage condition, focusing on EV capacity to protect their molecular cargo from biological, chemical, and mechanical damage. Compared with commonly used EV storage conditions, our EV storage buffer leads to less size and particle number variation at both 4 °C and −80 °C, enhancing the ability to protect EVs while maintaining targeting functionality.

Extracellular vesicles (EVs), detectable in all bodily fluids, mediate intercellular communication by transporting molecules between cells. The capacity of EVs to transport molecules between distant organs has drawn tremendous interest for clinical applications in diagnostics and therapeutics. Although EVs hold potential for nucleic acid-based and other molecular therapeutics, the lack of standardized technologies, including isolation, characterization, and storage, leaves many challenges for clinical applications, potentially resulting in misinterpretation of crucial findings. Previously, several groups demonstrated the problems of commonly used storage methods that distort EV integrity. This study reports a highly efficient EV storage condition, focusing on EV capacity to protect their molecular cargo from biological, chemical, and mechanical damage. Compared with commonly used EV storage conditions, our EV storage buffer leads to less size and particle number variation at both 4 C and -80 C, enhancing the ability to protect EVs while maintaining targeting functionality.

No abstract