More Like this

1. Choosing your own adventure: Engaging the new learning society through integrative curriculum design

   https://doi.org/10.29007/567f  

   Ryder, Elizabeth; Ruiz, Carolina; Weaver, Shari; Gegear, Robert (February 2020, EPiC Series in Education Science)

   In our increasingly data-driven society, it is critical for high school students to learn to integrate computational thinking with other disciplines in solving real world problems. To address this need for the life sciences in particular, we have developed the Bio-CS Bridge, a modular computational system coupled with curriculum integrating biology and computer science. Our transdisciplinary team comprises university and high school faculty and students with expertise in biology, computer science, and education. Our approach engages students and teachers in scientific practices using biological data that they can collect themselves, and computational tools that they help to design and implement, to address the real-world problem of pollinator decline. Our modular approach to high school curriculum design provides teachers with the educational flexibility to address national and statewide biology and computer science standards for a wide range of learner types. We are using a teacher- leader model to disseminate the Bio-CS Bridge, whose components will be freely available online. 

   more » « less
2. Parallel Strong Connectivity Based on Faster Reachability

   https://doi.org/10.1145/3589259  

   Wang, Letong; Dong, Xiaojun; Gu, Yan; Sun, Yihan (June 2023, Proceedings of the ACM on Management of Data)

   Computing strongly connected components (SCC) is among the most fundamental problems in graph analytics. Given the large size of today's real-world graphs, parallel SCC implementation is increasingly important. SCC is challenging in the parallel setting and is particularly hard on large-diameter graphs. Many existing parallel SCC implementations can be even slower than Tarjan's sequential algorithm on large-diameter graphs. To tackle this challenge, we propose an efficient parallel SCC implementation using a new parallel reachability approach. Our solution is based on a novel idea referred to as vertical granularity control (VGC). It breaks the synchronization barriers to increase parallelism and hide scheduling overhead. To use VGC in our SCC algorithm, we also design an efficient data structure called the parallel hash bag. It uses parallel dynamic resizing to avoid redundant work in maintaining frontiers (vertices processed in a round). We implement the parallel SCC algorithm by Blelloch et al. (J. ACM, 2020) using our new parallel reachability approach. We compare our implementation to the state-of-the-art systems, including GBBS, iSpan, Multi-step, and our highly optimized Tarjan's (sequential) algorithm, on 18 graphs, including social, web, k-NN, and lattice graphs. On a machine with 96 cores, our implementation is the fastest on 16 out of 18 graphs. On average (geometric means) over all graphs, our SCC is 6.0× faster than the best previous parallel code (GBBS), 12.8× faster than Tarjan's sequential algorithms, and 2.7× faster than the best existing implementation on each graph. We believe that our techniques are of independent interest. We also apply our parallel hash bag and VGC scheme to other graph problems, including connectivity and least-element lists (LE-lists). Our implementations improve the performance of the state-of-the-art parallel implementations for these two problems. 

   more » « less
3. The National Environmental Policy Act and the USDA Forest Service: Where We Agree, Where We Disagree, and Why

   https://doi.org/10.1093/jofore/fvab076  

   Fleischman, Forrest; Struthers, Cory; Arnold, Gwen; Dockry, Michael_J; Scott, Tyler (January 2022, Journal of Forestry)

   Abstract In this article, we respond to a critique of our earlier work examining the USDA Forest Service’s (USFS’s) planning processes. We appreciate that our critics introduce new data to the discussion of USFS planning. Further data integration is a promising path to developing a deeper understanding of agency activities. Our critics’ analysis largely supports our original claims. Our most important difference is in our conceptualization of the planning process’s relationship to agency goals. Although our critics conceive of the USFS’s legally prescribed planning processes as a barrier to land management activities, we believe that public comment periods, scientific analysis, and land management activities are tools the agency uses to achieve its goals of managing land in the public interest. Study Implications: The USDA Forest Service’s current planning process has been critiqued as a barrier to accomplishing land management activities, but it is also an important tool for insuring science-based management and understanding public values and interests that the agency is legally bound to uphold. 

   more » « less
4. Optimal resource allocation and prolonged dormancy strategies in herbaceous plants

   https://doi.org/10.1111/1365-2745.13466  

   Watts, J_Colton; Tenhumberg, Brigitte; Satake, ed., Akiko (August 2020, Journal of Ecology)

   Abstract Understanding the fitness consequences of different life histories is critical for explaining their diversity and for predicting effects of changing environmental conditions. However, current theory on plant life histories relies on phenomenological, rather than mechanistic, models of resource production.We combined a well‐supported mechanistic model of ontogenetic growth that incorporates differences in the size‐dependent scaling of gross resource production and maintenance costs with a dynamic optimization model to predict schedules of reproduction and prolonged dormancy (plants staying below ground for ≥1 growing season) that maximize lifetime offspring production.Our model makes three novel predictions: First, maintenance costs strongly influence the conditions under which a monocarpic or polycarpic life history evolves and how resources should be allocated to reproduction by polycarpic plants. Second, in contrast to previous theory, our model allows plants to compensate for low survival conditions by allocating a larger proportion of resources to storage and thereby improving overwinter survival. Incorporating this ecological mechanism in the model is critically important because without it our model never predicts significant investment into storage, which is inconsistent with empirical observations. Third, our model predicts that prolonged dormancy may evolve solely in response to resource allocation trade‐offs.Significance. Our findings reveal that maintenance costs and the effects of resource allocation on survival are primary determinants of the fitness consequences of different life history strategies, yet previous theory on plant life history evolution has largely ignored these factors. Our findings also validate recent arguments that prolonged dormancy may be an optimal response to costs of sprouting. These findings have broad implications for understanding patterns of plant life history variation and predicting plant responses to changing environments. 

   more » « less
5. Differences in individual flowering time change pollen limitation and seed set in three montane wildflowers

   https://doi.org/10.1002/ajb2.16123  

   Schiffer, Annie; Loy, Xingwen; Morozumi, Connor; Brosi, Berry J. (March 2023, American Journal of Botany)

   Abstract PremiseChanges to flowering time caused by climate change could affects plant fecundity, but studies that compare the individual‐level responses of phenologically distinct, co‐occurring species are lacking. We assessed how variation in floral phenology affects the fecundity of individuals from three montane species with different seasonal flowering times, including in snowmelt acceleration treatments to increase variability in phenology. MethodsWe collected floral phenology and seed set data for individuals of three montane plant species (Mertensia fusiformis, Delphinium nuttallianum, Potentilla pulcherrima). To examine the drivers of seed set, we measured conspecific floral density and conducted pollen limitation experiments to isolate pollination function. We advanced the phenology of plant communities in a controlled large‐scale snowmelt acceleration experiment. ResultsDifferences in individual phenology relative to the rest of the population affected fecundity in our focal species, but effects were species‐specific. For our early‐season species, individuals that bloomed later than the population peak bloom had increased fecundity, while for our midseason species, simply blooming before or after the population peak increased individual fecundity. For our late‐season species, blooming earlier than the population peak increased fecundity. The early and midseason species were pollen‐limited, and conspecific density affected seed set only for our early‐season species. ConclusionsOur study shows that variation in individual phenology affects fecundity in three phenologically distinct montane species, and that pollen limitation may be more influential than conspecific density. Our results suggest that individual‐level changes in phenology are important to consider for understanding plant reproductive success. 

   more » « less