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1. Geometry, analysis, and morphogenesis: Problems and prospects

   https://doi.org/10.1090/bull/1765  

   Lewicka, Marta; Mahadevan, L. (July 2022, Bulletin of the American Mathematical Society)

   The remarkable range of biological forms in and around us, such as the undulating shape of a leaf or flower in the garden, the coils in our gut, or the folds in our brain, raise a number of questions at the interface of biology, physics, and mathematics. How might these shapes be predicted, and how can they eventually be designed? We review our current understanding of this problem, which brings together analysis, geometry, and mechanics in the description of the morphogenesis of low-dimensional objects. Starting from the view that shape is the consequence of metric frustration in an ambient space, we examine the links between the classical Nash embedding problem and biological morphogenesis. Then, motivated by a range of experimental observations and numerical computations, we revisit known rigorous results on curvature-driven patterning of thin elastic films, especially the asymptotic behaviors of the solutions as the (scaled) thickness becomes vanishingly small and the local curvature can become large. Along the way, we discuss open problems that include those in mathematical modeling and analysis along with questions driven by the allure of being able to tame soft surfaces for applications in science and engineering. 

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2. Blockchains and Databases: Opportunities and Challenges for the Permissioned and the Permissionless

   https://doi.org/10.1007/978-3-030-54832-2_1  

   Agrawal, D.; El Abbadi, A.; Amiri, M.J.; Maiyya, S.; Zakhary, V. (August 2020, Advances in Databases and Information Systems)

   Darmont, J; Novikov, B.; Wrembel, R. (Ed.)

   Bitcoin [12] is a successful and interesting example of a global scale peer-to-peer cryptocurrency that integrates many techniques and protocols from cryptography, distributed systems, and databases. The main underlying data structure is blockchain, a scalable fully replicated structure that is shared among all participants and guarantees a consistent view of all user transactions by all participants in the system. In a blockchain, nodes agree on their shared states across a large network of untrusted participants. Although originally devised for cryptocurrencies, recent systems exploit its many unique features such as transparency, provenance, fault tolerance, and authenticity to support a wide range of distributed applications. Bitcoin and other cryptocurrencies use permissionless blockchains. In a permissionless blockchain, the network is public, and anyone can participate without a specific identity. Many other distributed applications, such as supply chain management and healthcare, are deployed on permissioned blockchains consisting of a set of known, identified nodes that still might not fully trust each other. This paper illustrates some of the main challenges and opportunities from a database perspective in the many novel and interesting application domains of blockchains. These opportunities are illustrated using various examples from recent research in both permissionless and permissioned blockchains. Two main themes unite the various examples: (1) the important role of distribution and consensus in managing large scale systems and (2) the need to tolerate malicious failures. The advent of cloud computing and large data centers shifted large scale data management infrastructures from centralized databases to distributed systems. One of the main challenges in designing distributed systems is the need for fault-tolerance. Cloud-based systems typically assume trusted infrastructures, since data centers are owned by the enterprises managing the data, and hence the design typically only assumes and tolerates crash failures. The advent of blockchain and the underlying premise that copies of the blockchain are distributed among untrusted entities has shifted the focus of fault-tolerance from tolerating crash failures to tolerating malicious failures. These interesting and challenging settings pose great opportunities for database researchers. 

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3. Assessing Awareness and Competency of Engineering Freshmen on Ethical and Responsible Research and Practices

   Johnson, M.D. (January 2023, American Society of Engineering Education Annual Conference)

   This paper presents the progress made in the first year of a five-year NSF ER2 (Ethical and Responsible Research)-funded project on ethical and responsible research and practices in science and engineering undertaken at a large public university in the southwestern United States. The objective of this research is to improve instructor training, interventions, and student outcomes in high schools and universities to improve awareness and commitment to ethical practices in STEM coursework. The paper will describe the progress made in several components of the grant: i) Preliminary analysis of measures of ethical knowledge, reasoning skills, attitudes, and practices of several hundred undergraduate freshmen and seniors, correlated with demographic data, based on data captured in the first year of the grant; ii) Progress made in the development of the concept of “ethical self-efficacy” and an instrument to measure it for freshmen and senior engineering students, and in assessing how it relates to ethical competency and student background; iii) Implications of these analyses in the construction of a three-week professional development program that guides high school STEM teachers through the development of learning modules on ethical issues related to their courses; iv) The assessment of the undergraduate engineering curriculum in two majors to determine appropriate courses for ethics interventions to help students understand how technical activities fit within broader social, economic, and environmental contexts; the construction of these interventions; and the development of measures to track their success; and, v) Initial steps toward measuring impact of other experiences (e.g., undergraduate research, internships, service learning) and courses (e.g., humanities, social science, and business courses) on development of ethical practices, on assessments taken in senior engineering capstone courses. 

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4. Ohm’s law lost and regained: observation and impact of transmission and velocity zeros

   https://doi.org/10.1038/s41467-024-54012-8  

   Joshi, Krishna; Kurtz, Israel; Shi, Zhou; Genack, Azriel_Z (December 2024, Nature Communications)

   Abstract The quantum conductance and its classical wave analogue, the transmittance, are given by the sum of the eigenvalues of the transmission matrix. However, neither measurements nor theoretical analysis of the transmission eigenchannels have been carried out to explain the dips in conductance found in simulations as new channels are introduced. Here, we measure the microwave transmission matrices of random waveguides and find the spectra of all transmission eigenvalues, even at dips in the lowest transmission eigenchannel that are orders of magnitude below the noise in the transmission matrix. Transmission vanishes both at topological transmission zeros, where the energy density at the sample output vanishes, and at crossovers to new channels, where the longitudinal velocity vanishes. Zeros of transmission pull down all the transmission eigenvalues and thereby produce dips in the transmittance. These dips and the ability to probe the characteristics of even the lowest transmission eigenchannel are due to correlation among the eigenvalues. The precise tracking of dips in the conductance by peaks in the density of states points to a further correlation between zeros and poles of the transmission matrix. The conductance approaches Ohm’s law as the sample width increases in accord with the correspondence principle. 

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5. PFAS in biotic and abiotic matrices in coastal and estuarine ecosystems: Temporal and seasonal distribution, discharge and environmental impacts

   https://doi.org/10.1002/jeq2.70047  

   Ehsan, Mohammad_Nazmul; Pervez, Md_Nahid; Alam, S_M_Masum; Liang, Yanna; Naddeo, Vincenzo (June 2025, Journal of Environmental Quality)

   Abstract Besides freshwater ecosystems such as lakes and rivers, estuaries and coastal regions are crucial to the global distribution of per‐ and polyfluoroalkyl substances (PFAS) through the ocean and their impacts and transport throughout the food web. This review includes a comprehensive assessment of the concentration and distribution of legacy and emerging PFAS compounds in living species, such as plants and aquatic creatures, as well as in abiotic components, such as surface water and sediment within estuarine ecosystems. This paper also explores the temporal and seasonal patterns of PFAS emissions, as well as the fate of both long‐ and short‐chain PFAS compounds. Furthermore, it discusses the partitioning behavior, bioaccumulation, and trophic magnification of PFAS in estuarine environments. PFAS are widespread in estuary sediment and surface water, and sediments continue to serve as a significant reservoir for these substances. The temporal trend suggests that the introduction of legislation and the gradual phaseout of some PFAS groups may have led to a decrease in their concentration levels. Elevated levels of PFAS in estuary aquatic animals and their ability to bioaccumulate and biomagnify in aquatic food webs could lead to long‐term negative health effects on the surrounding population and ecosystem. 

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