Sequence conservation analyses offer us a powerful glimpse of natural selection at work. Standard tools for measuring sequence conservation report conservation as a function of a specific location in a multiple sequence alignment and have proven indispensable in identifying highly constrained features such as active site residues. The advent of large-scale genomic sequencing efforts allows researchers to expand this paradigm and investigate more nuanced relationships between sequence and function.
View Article and Find Full Text PDFSince the 1930s, California's Sierra Nevada has warmed by an average of 1.2 C. Warming directly primes forests for easier wildfire ignition, but the change in climate also affects vegetation species composition.
View Article and Find Full Text PDFNASA mission systems proposals are often compared using an equivalent system mass (ESM) framework, wherein all elements of a technology to deliver an effect-its components, operations, and logistics of delivery-are converted to effective masses, which has a known cost scale in space operations. To date, ESM methods and the tools for system comparison largely fail to consider complexities stemming from multiple transit and operations stages, such as would be required to support a crewed mission to Mars, and thus do not account for different mass equivalency factors during each period and the inter-dependencies of the costs across the mission segments. Further, ESM does not account well for the differential reliabilities of the underlying technologies.
View Article and Find Full Text PDFDue to climate change, plant populations experience environmental conditions to which they are not adapted. Our understanding of the next century's vegetation geography depends on the distance, direction, and rate at which plant distributions shift in response to a changing climate. In this study we test the sensitivity of tree range shifts (measured as the difference between seedling and mature tree ranges in climate space) to wildfire occurrence, using 74,069 Forest Inventory Analysis plots across nine states in the western United States.
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