More Like this

1. A note on dispersing particles on a line

   https://doi.org/10.1002/rsa.20821  

   Frieze, Alan; Pegden, Wesley (October 2018, Random Structures & Algorithms)

   We consider a synchronous dispersion process introduced in pervious study of Cooper and coworkers and we show that on the infinite line the final set of occupied sites takes upO(n) space, wherenis the number of particles involved. 

   more » « less
2. When does a stream become a river?

   https://doi.org/10.1002/rra.4185  

   Czuba, Jonathan_A; Allen, George_H (July 2023, River Research and Applications)

   Abstract The distinction between a “stream” and “river” is imprecise and vague despite the popular usage of the terms across disciplines for describing flowing waterbodies. Based on an analysis of named flowing waterbodies in the continental United States, we suggest a bank‐to‐bank channel width of 15 m as a working threshold in defining smaller “streams” from larger “rivers.” 

   more » « less
3. A new type of superorthogonality

   https://doi.org/10.1090/proc/16631  

   Gressman, Philip; Pierce, Lillian; Roos, Joris; Yung, Po-Lam (February 2024, Proceedings of the American Mathematical Society)

   We provide a simple criterion on a family of functions that implies a square function estimate on $L^p$for every even integer $p\ge <\#comment/>2$. This defines a new type of superorthogonality that is verified by checking a less restrictive criterion than any other type of superorthogonality that is currently known. 

   more » « less
4. Towards a predictive framework for biocrust mediation of plant performance: A meta‐analysis

   https://doi.org/10.1111/1365-2745.13269  

   Havrilla, Caroline A.; Chaudhary, V. Bala; Ferrenberg, Scott; Antoninka, Anita J.; Belnap, Jayne; Bowker, Matthew A.; Eldridge, David J.; Faist, Akasha M.; Huber‐Sannwald, Elisabeth; Leslie, Alexander D.; et al (September 2019, Journal of Ecology)

   Abstract Understanding the importance of biotic interactions in driving the distribution and abundance of species is a central goal of plant ecology. Early vascular plants likely colonized land occupied by biocrusts — photoautotrophic, surface‐dwelling soil communities comprised of cyanobacteria, bryophytes, lichens and fungi — suggesting biotic interactions between biocrusts and plants have been at play for some 2,000 million years. Today, biocrusts coexist with plants in dryland ecosystems worldwide, and have been shown to both facilitate or inhibit plant species performance depending on ecological context. Yet, the factors that drive the direction and magnitude of these effects remain largely unknown.We conducted a meta‐analysis of plant responses to biocrusts using a global dataset encompassing 1,004 studies from six continents.Meta‐analysis revealed there is no simple positive or negative effect of biocrusts on plants. Rather, plant responses differ by biocrust composition and plant species traits and vary across plant ontogeny. Moss‐dominated biocrusts facilitated, while lichen‐dominated biocrusts inhibited overall plant performance. Plant responses also varied among plant functional groups: C₄grasses received greater benefits from biocrusts compared to C₃grasses, and plants without N‐fixing symbionts responded more positively to biocrusts than plants with N‐fixing symbionts. Biocrusts decreased germination but facilitated growth of non‐native plant species.Synthesis. Results suggest that interspecific variation in plant responses to biocrusts, contingent on biocrust type, plant traits, and ontogeny can have strong impacts on plant species performance. These findings have important implications for understanding biocrust contributions to plant productivity and community assembly processes in ecosystems worldwide. 

   more » « less
5. Morphological and mechanical characterization of a novel porous silicon membrane used in a lung-on-a-chip system

   https://doi.org/10.1557/s43580-023-00667-2  

   Genc, Sahra; Thompson, Sally; Hill, Owen; Gislason, Leif; Rodriguez, Dakota; Showme, Farjana; Motler, Alex; Schreiner, Sarah M.; Gestos, Adrian; Ferguson, Virginia L.; et al (October 2023, MRS Advances)

   Abstract In the last decade, organ-on-a-chip technology has been researched as an alternative to animal and cell culture models (Buhidma et al. in NPJ Parkinson’s Dis, 2020; Pearce et al. in Eur Cells Mater 13:1–10, 2007; Huh et al. in Nat Protoc 8:2135–2157, 2013). While extensive research has focused on the biological functions of these chips, there has been limited exploration of functional materials that can accurately replicate the biological environment. Our group concentrated on a lung-on-a-chip featuring a newly fabricated porous silicon bio-membrane. This bio-membrane mimics the interstitial space found between epithelial and endothelial cells in vivo, with a thickness of approximately 1 μm (Ingber in Cell 164:1105–1109, 2016). This study aims to establish a fabrication method for producing a thin, uniform porous silicon membrane with a predictablereduced modulus. We conducted mechanical and morphological characterization using scanning electron microscopy and nanoindentation. A small, parametric study was conducted to determine the reduced modulus of the porous silicon and how it may relate to the morphological features of the membrane. We compare our results to other works. Graphical Abstract 

   more » « less