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Dynamic coasts, resilient futures: Navigating changes in the Great Lakes – Foreword to the special section
No full textHistorically, research on coastal processes has largely been concentrated on oceanic environments which have much in common with the Great Lakes but also differ in significant ways. This is particularly true with respect to substantial and lasting water level fluctuations that occur on seasonal and decadal time scales that differ temporally from shorter term tidal fluctuations and greatly exceed long-term oceanic sea level rise. Since the late 1990s, the Great Lakes basin has experienced record-breaking high and low water levels as well as more frequent and intense storms. This combination of factors has led to changes to these nearshore environments and stimulated new and exciting coastal research characterizing and quantifying these changes and offering new insights into Great Lakes coastal processes. Studies in this special section address these unique coastal landscapes shaped by both natural forces (e.g., ice dynamics, waves, and fluctuating lake levels) and human influences (armoring, coastal structures, sediment nourishment, and policy interventions). The findings shared in this collection provide actionable knowledge for anticipating change, mitigating risk, and building long-term resilience while calling for adaptive management frameworks to foster proactive, equitable stewardship of the Great Lakes shorelines
Orbital Modulation of Gamma Rays up to 100 TeV from LS 5039
No full textGamma-ray binaries are luminous in gamma rays, composed of a compact object orbiting a massive companion star. The interaction between these two objects can drive relativistic outflows, either jets or winds, in which particles can be accelerated to energies reaching hundreds of teraelectronvolts (TeV). However, it is still debated where and under which physical conditions particles are accelerated in these objects and ultimately whether protons can be accelerated up to PeV energies. Among the well-known gamma-ray binaries, LS 5039 is a high-mass X-ray binary with an orbital period of 3.9 days that has been observed up to TeV energies by the High Energy Stereoscopic System. We present new observations of LS 5039 obtained with the High Altitude Water Cherenkov (HAWC) observatory. Our data reveal that the gamma-ray spectrum of LS 5039 extends up to 200 TeV with no apparent spectral cutoff. Furthermore, we confirm, with a confidence level of 4.7σ, that the emission between 2 and 118 TeV is modulated by the orbital motion of the system, and find a 2.2σ hint of variability above 100 TeV. This indicates that these photons are likely produced within or near the binary orbit, where they can undergo absorption by the stellar photons. In a leptonic scenario, the highest energy photons detected by HAWC can be emitted by ∼200 TeV electrons inverse Compton scattering stellar photons, which would require an extremely efficient acceleration mechanism operating within LS 5039. Alternatively, a hadronic scenario could explain the data through proton-proton or proton-gamma collisions of protons accelerated to petaelectronvolt energies
Stability analysis of the Eulerian-Lagrangian finite volume methods for nonlinear hyperbolic equations in one space dimension
Get PDFIn this paper, we construct a novel Eulerian-Lagrangian finite volume (ELFV) method for nonlinear scalar hyperbolic equations in one space dimension. It is well known that the exact solutions to such problems may contain shocks though the initial conditions are smooth, and direct numerical methods may suffer from restricted time step sizes. To relieve the restriction, we propose an ELFV method, where the space-time domain was separated by the partition lines originated from the cell interfaces whose slopes are obtained following the Rakine-Hugoniot junmp condition. Unfortunately, to avoid the intersection of the partition lines, the time step sizes are still limited. To fix this gap, we detect effective troubled cells (ETCs) and carefully design the influence region of each ETC, within which the partitioned space-time regions are merged together to form a new one. Then with the new partition of the space-time domain, we theoretically prove that the proposed first-order scheme with Euler forward time discretization is total-variation-diminishing and maximum-principle-preserving with at least twice larger time step constraints than the classical first order Eulerian method for Burgers-equation. Numerical experiments verify the optimality of the designed time step sizes
Hourly Simulated Power Production Data with Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Single-Axis Tracking Systems in the U.S. Eastern Interconnection for Weather Year 2016
No full textUsing 2016 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory’s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be single-axis tracking systems. Sites’ latitudes and longitudes were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with Snow Loss Model at Queued Utility-Scale PV Sites Simulated as Single-Axis Tracking Systems in the U.S. Eastern Interconnection for Weather Year 2020
No full textUsing 2020 weather data, we ran PySAM power production simulations for utility-scale PV sites in the U.S. Eastern Interconnection queue. Site IDs, capacities, and locations (counties) were extracted from Lawrence Berkeley National Laboratory’s Queued Up: 2024 Edition dataset. No panel mount information was provided, so all sites were assumed to be single-axis tracking systems. Sites’ latitudes and longitudes were assumed to be the centers of the installation counties. See queued_site_metadata.csv file for individual site metadata
Real-Time Monitoring of Mitochondrial pH in HeLa Cells, Drosophila melanogaster, and Zebrafish Larvae Using BODIPY-Based Ratiometric Fluorescent Probes
No full textThree BODIPY-based fluorescent probes, AH+, BH+, and CH+, were synthesized for ratiometric pH sensing in living cells, fruit flies, and zebrafish larvae. These probes were designed to target mitochondrial environments by functionalizing the BODIPY core with various substituent groups that tune the pH sensitivity. The probes exhibited strong ratiometric fluorescence changes with pKa values (AH+, 7.3; BH+, 7.5; CH+, 7.2) suitable for mitochondrial pH detection. Theoretical calculations supported these findings by establishing the geometries and electronic transitions and also resulted in the derivation of their pKa values. Confocal imaging confirmed mitochondrial accumulation of these probes in HeLa cells, facilitating broad-range pH monitoring across a wide pH spectrum (3.5 to 9.1). These ratiometric pH sensors display good reversibility and response times under varying pH conditions. In application, the probe AH+ was employed to monitor pH fluctuations under conditions of oxidative stress and nutrient deprivation. Dual-channel cell imaging revealed a pH-dependent fluorescence shift with precise transitions, demonstrating the feasibility of real-time monitoring of the mitochondrial membrane potential in living cells. Furthermore, the probe AH+ effectively visualized pH changes in Drosophila melanogaster and zebrafish larvae, further supporting its applicability across diverse biological systems. We demonstrate that a fluorescence ratiometric intensity graph for probe AH+ can be effectively employed to determine pH values within the mitochondria of HeLa cells
Energy-Efficient Neuromorphic Closed-Loop Modulation System for Parkinson\u27s Disease
No full textParkinson\u27s Disease (PD) impacts millions globally, causing debilitating motor symptoms. While Closed-Loop Deep Brain Stimulation (CL-DBS) has emerged as a promising treatment, existing systems often suffer from high energy consumption, making them impractical for wearable or implantable devices. This research introduces an innovative neuromorphic approach to enhance CL-DBS performance, utilizing Leaky Integrate-and-Fire (LIF) neuron-based controllers to adaptively modulate stimulation signals based on symptom severity. Two controllers, the on-off LIF and dual LIF models, are proposed, achieving significant reductions in power consumption by 19% and 56%, respectively, while enhancing suppression efficiency by 4.7% and 6.77%. Additionally, this work addresses the scarcity of datasets for PD symptoms by developing a novel dataset featuring neural activity from the subthalamic nucleus (STN), incorporating beta oscillations as key physiological biomarkers. This dataset aims to support further advancements in neuromorphic CL-DBS systems and is openly shared with the research community. By combining energy-efficient neuromorphic controllers with a comprehensive dataset, this study not only advances the technological feasibility of CL-DBS systems for PD treatment but also provides a foundation for personalized and adaptive neuromodulation therapies, paving the way for improved quality of life for individuals with Parkinson\u27s Disease
Hourly Simulated Power Production Data with No Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2013
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2013. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2013_PV_existing_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with No Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2015
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2015. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2015_PV_existing_site_metadata.csv file for individual site metadata
Hourly Simulated Power Production Data with No Snow Loss Model at Existing Utility-Scale PV Sites (\u3e5 MW) in the U.S. Eastern Interconnection in 2018
No full textProject Summary: We ran PySAM power production simulations for utility-scale (\u3e5 MW) PV sites located in the U.S. Eastern Interconnection in the year 2018. Site panel mounts (fixed-tilt or single-axis tracking), capacities, and locations (latitudes and longitudes) were extracted from Lawrence Berkeley National Laboratory\u27s Utility-Scale Solar 2024 Edition dataset. See 2018_PV_existing_site_metadata.csv file for individual site metadata