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The California floristic province is home to more than 30% of all Castilleja species across the North American wildflower genus (family Orobanchaceae). While some of the approximately 200 species are distinct morphologically, the five species composing the coastal California Castilleja species complex exhibit overlapping morphologies and geographic ranges, which poses particular challenges for species identification. To determine species, current keys employ a combination of geography, leaves, and reproductive structures. The sepals, known collectively as the calyx, are modified leaves that protect the flower and have historically been one of several important traits for diagnosing species in the complex. In this project, we utilized geometric morphometrics to quantify and describe calyx shape for three calyces per individual of five individuals across seven species, including two outgroups (n = 84). While traditional morphometrics only capture linear variation, geometric morphometrics translate more complex elements of shape. Calyx outlines were created from field scans and analyzed with Procrustes-based geometric morphometrics using three landmarks, followed by elliptic Fourier analysis. The first principal component axis across all samples explained 43.8% of variation and emphasized the depths of the calyx clefts relative to each other. Several species overlap in the morphospace while others remain distinct, which suggests limited morphological differentiation of the calyx across species and may allow for variation in successful pollination. Future analyses will quantify morphological variation in other floral organs observed both within individuals and within species to comprehensively assess morphological variation in the complex. 

Biomimetics must be taught to the next generation of designers in the interest of delivering solutions for current problems. Teaching biomimetics involves teachers and students from and in various disciplines at different stages of the educational system. There is no common understanding of how and what to teach in the different phases of the educational pipeline. This manuscript describes different perspectives, expectations, needs, and challenges of users from various backgrounds. It focuses on how biomimetics is taught at the various stages of education and career: from K-12 to higher education to continuing education. By constructing the biomimetics education pipeline, we find that some industry challenges are addressed and provide opportunities to transfer the lessons to application. We also identify existing gaps in the biomimetics education pipeline that could further advance industry application if a curriculum is developed. 

A 63‐year observational record in the southwest Ross Sea shows a continuing, near‐linear salinity decrease of 0.170 and slight warming of 0.013°C through 2020. That freshening exceeded any increase in sea ice production and brine release from stronger southerly winds, while melting and freezing at the Ross Ice Shelf base contributed little to the salinity change. The parallel seawater density decline appears not to have enhanced warm deep water intrusions onto the continental shelf (CS). Confirming prior inferences, the salinity change has been mainly caused by a growing imbalance in the meltwater available from thinning ice shelves and increased iceberg calving in the upstream Amundsen and Bellingshausen Seas. Shorter‐term salinity variability has tracked winds near the Amundsen Sea CS break, in turn coherent with a broader Pacific climate variability index, and with salinity reversals on and seaward of the Ross CS. The melt driven freshening is positively correlated with global atmospheric CO₂and temperature increases, and adds to the rise in sea level from increased glacier flow into weakened ice shelves. Continued erosion of those ice shelves could end the production of high salinity shelf and bottom waters, as defined in the Ross Sea, by the 2050s.

 

We studied Native American college students’ perceptions of educational barriers and supports while pursuing degrees leading to careers in engineering. Based on findings from our qualitative study, we provide recommendations for students, professors, departments, and institutions on how to support Native American students to be successful as they pursue careers in science, math, and engineering careers. 

Science, technology, engineering, and mathematics (STEM) education initiatives in higher education increasingly call for career mentorship opportunities for underrepresented minorities (URM). Researchers (Johnson & Sheppard, 2004; Nelson & Brammer, 2010) note the importance of having faculty to mentor and act as role models for students, often assuming that mentors play a stronger role if they are also from the same cultural background. Native American (NA) faculty members are underrepresented in most fields in colleges and universities, and exceedingly so in engineering. Only 0.2% (N=68) of engineering faculty nationwide identify as Native American (Yoder, 2014). Likewise, NA students are underrepresented in undergraduate (0.6%; N=1853) and graduate (0.1%; N=173) engineering programs. The low percentage in graduate school is of even greater concern as they represent the primary potential pool of new faculty members. Advising and mentorship from those who identify as NA are often considered important components recruiting and retention in STEM fields. For example, Smith and colleagues (2014) found that factors such as communal goal orientation influenced NA engineering students’ motivation and academic performance. However, very few studies account for differences in NA identity or provide a nuanced account of successful NA STEM professional experiences (Page-Reeves et al., 2018). This research paper presents findings from an exploratory study aimed at pinpointing the factors that influence NA entry and persistence in engineering faculty positions. 

Mass loss from the Amundsen Sea sector of the West Antarctic Ice Sheet has increased in recent decades, suggestive of sus- tained ocean forcing or an ongoing, possibly unstable, response to a past climate anomaly. Lengthening satellite records appear to be incompatible with either process, however, revealing both periodic hiatuses in acceleration and intermittent episodes of thinning. Here we use ocean temperature, salinity, dissolved-oxygen and current measurements taken from 2000 to 2016 near the Dotson Ice Shelf to determine temporal changes in net basal melting. A decadal cycle dominates the ocean record, with melt changing by a factor of about four between cool and warm extremes via a nonlinear relationship with ocean temperature. A warm phase that peaked around 2009 coincided with ice-shelf thinning and retreat of the grounding line, which re-advanced during a post-2011 cool phase. These observations demonstrate how discontinuous ice retreat is linked with ocean variability, and that the strength and timing of decadal extremes is more influential than changes in the longer-term mean state. The non- linear response of melting to temperature change heightens the sensitivity of Amundsen Sea ice shelves to such variability, possibly explaining the vulnerability of the ice sheet in that sector, where subsurface ocean temperatures are relatively high.