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Comparative analysis of gridded precipitation products and the development of a blended product in the Andes and surrounding regions
No full textAccurate precipitation estimates are essential for land surface models and the management of water resources. However, traditional gauge-based precipitation measurements are limited by spatial and temporal coverage and are prone to errors and uncertainties. Gridded precipitation products derived from reanalysis data and satellite observations offer a more continuous and comprehensive alternative, though their performance varies regionally and is often uncertain. This study evaluates the performance of five widely available gridded precipitation products (MERRA-2, ERA5, CHIRPS, MSWEP, and IMERG) across the Andes and surrounding regions. Using gauges and the Extended Triple Collocation (ETC) method, we assess the accuracy and reliability of these products at daily, seasonal, and annual scales over the period 2001–2023. Our results indicate that MERRA-2 has the lowest errors when compared with gauges, followed by MSWEP and ERA5. CHIRPS shows a high probability of detecting precipitation events but tends to overestimate, resulting in higher errors. IMERG outperforms others in the ETC analysis, with the lowest errors and highest correlation coefficient. Recognizing the lack of a single best-performing product, we developed MIMERG, a new gridded product that combines MERRA-2 and IMERG through advanced interpolation techniques based on the Braseth algorithm. MIMERG demonstrates improved performance over MERRA-2 in ETC analysis and enhances IMERG’s alignment with gauges. This study highlights the importance of tailored precipitation product selection and the potential for innovative combinations like MIMERG to improve precipitation estimates, ultimately supporting more accurate environmental modeling and water resource management.This research was supported by the grant from the National Aeronautics and Space Administration High Mountain Asia program (23-HMA23-0021). Computing was supported by the resources at the NASA Center for Climate Simulationhttps://journals.ametsoc.org/view/journals/hydr/aop/JHM-D-25-0035.1/JHM-D-25-0035.1.xm
SENSE OF COMMUNITY AND THE OPIOID USE RECOVERY OF BLACK INDIVIDUALS: A QUALITATIVE ANALYSIS
No full textSubstance use has a complex and multifaceted history. While substance use itself is not necessarily problematic and does not always lead to negative outcomes, for individuals with substance use disorder, the impact can be significant. Substance use disorder can affect various aspects of life, including physical and mental health, relationships, community involvement, and one’s relationship with society. Treatment is crucial in helping individuals achieve their personal recovery goals related to substance use, making effective treatment options essential. However, recovery is often a prolonged and difficult journey, and many individuals discontinue treatment before reaching their desired outcomes. One key factor that may influence treatment completion is a sense of community, defined as a feeling of belonging, significance, and acceptance within a group. Research has shown that sense of community is an important motivator for individuals to continue treatment. Despite this, research is limited on how sense of community influences recovery, particularly from the perspective of Black individuals, aged 18-70, who are living with opioid use disorder. The goal of this study is to explore how sense of community, both within treatment settings and in the broader community, shapes the recovery process for this demographic. Fifteen participants from substance use treatment centers in Baltimore and Rockville, MD, were interviewed at three intervals over six months to track their experiences of community at different stages of recovery. A phenomenological approach was employed to analyze the interviews. The findings suggest that sense of community plays a vital role in the recovery journey of Black individuals with OUD. However, the impact of community on recovery is not uniform among all participants. Several key factors, including the individual’s definition of recovery, motivations, past recovery experiences, and environmental influences, shape how they interact with and benefit from various communities. This research not only contributes to the existing literature on substance use recovery but also emphasizes the need for further exploration into how sense of community can be intentionally incorporated into treatment programs
A Systematic Search for MeV–GeV Pulsar Wind Nebulae without Gamma-Ray Detected Pulsars
No full textAn increasing number of pulsar wind nebulae (PWNe) are being identified in the TeV band by ground-based Imaging Air Cherenkov Telescopes such that they constitute the dominant source class of Galactic TeV emitters. However, MeV–GeV PWN counterparts are still largely lacking. To date, only a dozen PWNe are identified by the Fermi–Large Area Telescope (LAT) in the MeV–GeV band. Most PWNe are located along the Galactic plane embedded within the prominent, diffuse Galactic γ-ray emission, which makes these sources difficult to disentangle from the bright diffuse background. We present a systematic search for γ-ray counterparts to known PWNe in the 300 MeV–2 TeV energy band using the Fermi–LAT. We target the locations of previously identified PWNe that lack detected Fermi–LAT pulsars to minimize associated pulsar contamination. The sample includes six previously identified Fermi PWNe and eight Fermi–LAT sources associated with PWNe. We report the analysis of 58 regions of interest and classify Fermi–LAT detected sources as either a likely PWN or a candidate PWN counterpart based on their morphological and spectral characteristics across the broadband spectrum. There are nine unidentified Fermi–LAT sources that we consider as likely PWN counterparts, which, if confirmed to be PWNe, would greatly increase the PWN population detected by the Fermi–LAT from 12 to 21. The remaining Fermi–LAT detected sources are considered weaker PWN candidates. A second approach in the systematic search for γ-ray emitting PWNe will involve studying the off-pulse phases of Fermi–LAT detected pulsars for the presence of an obscured PWN and will be reported in a subsequent paper.The Fermi–LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden.Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. This work performed in part under DOE contract DE- AC02-76SF00515.This work has also been partially supported by the grant PID2021-124581OB-I00 funded by MCIN/AEI/10.13039/501100011033, 2021SGR00426, by the Spanish program Unidad de Excelencia María de Maeztu CEX2020-001058-M, and European Union NextGeneration EU funds (PRTR-C17.I1)https://iopscience.iop.org/article/10.3847/1538-4357/ade8f0/met
Emissive Surface Traps Lead to Asymmetric Photoluminescence Line Shape in Spheroidal CsPbBr3 Quantum Dots
No full textThe morphology of quantum dots plays an important role in governing their photophysics. Here, we explore the photoluminescence of spheroidal CsPbBr₃ quantum dots synthesized via the room-temperature trioctylphosphine oxide/PbBr₂ method. Despite photoluminescence quantum yields nearing 100%, these spheroidal quantum dots exhibit an elongated red photoluminescence tail not observed in typical cubic quantum dots synthesized via hot injection. We explore the origins of this elongated red tail through structural and optical characterization including small-angle X-ray scattering, transmission electron microscopy and time-resolved, steady-state, and single quantum dot photoluminescence. From these measurements we conclude that the red tail originates from emissive traps. We show that treating spheroidal quantum dots with phenethylammonium bromide decreases the line shape asymmetry and increases passivation–consistent with emissive traps due to polar facets.This work, and the roles of J.K., S.G., B.F.H, R.M., D.M.L., J.N.P., M.F.T., M.P., S.Y., G.D. and D.S.G were primarily supported by the National Science Foundation under the STC IMOD Grant (No. DMR2019444). B.F.H. and D.M.L. acknowledge support from the National Science Foundation through the Graduate Research Fellowship Program (NSF-GRFP) under Grant No. DGE 2040434. R.J.E.W. carried out streak camera measurements and was supported by the Office of Naval Research (ONR N000-14-20- 1-2191) and the Momental Foundation via the Mistletoe Fellowship. The authors acknowledge the use of facilities and instruments at the Photonics Research Center (PRC) at the Department of Chemistry, University of Washington, as well as that at the Research Training Testbed (RTT), part of the Washington Clean Energy Testbeds system. Part of this work was carried out at the Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure site at the University of Washington which is supported in part by the National Science Foundation (NNCI-1542101), the Molecular Engineering & Sciences Institute, and the Clean Energy Institute. TEM was carried out at the Facility for Electron Microscopy of Materials at the University of Colorado Boulder (CU FEMM, RRID: SCR_019306). J.K. acknowledges David M. Jonas (professor, University of Colorado Boulder) for discussion regarding potential causes of an elongated red photoluminescence tail in quantum dots. D.M.L. acknowledges use of the SasView application for fitting SAXS data. SasView was originally developed under NSF award DMR-0520547 and contains code developed with funding from the European Union’s Horizon 2020 research and innovation program under the SINE2020 project, grant agreement No 654000. B.F.H. acknowledges Olivia F. Bird (graduate student, University of Colorado Boulder) and Sophia M. Click (postdoctoral researcher, University of Colorado Boulder) for discussions related to TEM image segmentation and size analysis using Trainable Weka Segmentation in ImageJ.https://pubs.acs.org/doi/full/10.1021/acs.nanolett.4c0499
Sensitivity of the Shallow-to-Deep Convective Transition to Moisture and Wind Shear in the Amazon
No full textDeep convection is the primary influence on weather and climate in tropical regions. However, understanding and simulating the shallow-to-deep (STD) convective transition has long been challenging. Here, we conduct high-resolution numerical simulations to assess the environmental controls on the evolution of isolated convection in the Amazon during the wet season. The large-scale forcing derived through a constrained variational analysis approach for the GoAmazon2014/5 Experiment is used in the simulations. Through sensitivity experiments, we examine the relative importance of moisture and wind shear in controlling the shallow-to-deep convective transition for isolated convective events. Convection exhibits the greatest sensitivity to humidity within the lowest 1.5 km, where a 4 mm reduction in column water vapor nearly suppresses ice water formation on deep convective days. In contrast, a reduction in column water vapor in the free troposphere by a factor of two or more is necessary to produce a comparable impact on convection. Increasing low-level wind speed from 6 to 9 m s⁻¹ enhances afternoon deep convection, raising the cloud ice mixing ratio by approximately 25%. Conversely, upper-level wind shear reveals the weakest correlation with daytime convection in our simulations. Our results help characterize the role of moisture and wind shear on the STD transition and our understanding of the underlying mechanisms.The authors express their gratitude to Marat Khairoutdinov for providing access to the SAM code and for offering valuable assistance with the Land Surface Model. The technical support and advanced computing resources from University of Hawai‘i Information Technology Services – Cyberinfrastructure, funded in part by the National Science Foundation CC∗awards # 2201428 and # 2232862 are gratefully acknowledged. We also acknowledge the data from the Atmospheric Radiation Measurement (ARM) Program sponsored by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Climate and Environmental Sciences Division. L.A.M.V. acknowledges the Brazilian National Council for Scientific and Technological Development (CNPq) graduate fellowship (grant number 148652/2019-0). Additionally, gratitude is extended to the Coordination for the Improvement of Higher Education Personnel (CAPES) fellowship (grant number 88887.571091/2020-00). H.M.J.B acknowledges support from the –19– manuscript submitted to Journal of Advances in Modeling Earth Systems (JAMES) U.S. Department of Energy, Office of Science, Biological and Environmental Research program under Award Number DE-SC-0023058.https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2024MS00423
The Debate Over Taxes in Maryland
No full textThe state of Maryland is looking down a deep fiscal hole as the 2025 General Assembly session begins. Sunil Dasgupta asks state Senate leaders, Brian Feldman, chair of the Education, Energy, and Environment Committee, and Jim Rosapepe, vice-chair of the Budget and Taxation Committee, for their solutions. Newly in public domain music by Nacio Herb Brown and the Carl Fenton band.https://open.spotify.com/episode/79Jnd8VcCq4flJE6jwPCI
Influence of cognitive networks and task performance on fMRI-based state classification using DNN models
No full textDeep neural networks (DNNs) excel at extracting insights from complex data across various fields, however, their application in cognitive neuroscience remains limited, largely due to the lack of approaches with interpretability. Here, we employ two different and complementary DNN models, a one-dimensional convolutional neural network (1D-CNN) and a bidirectional long short-term memory network (BiLSTM), to classify cognitive task states from fMRI data, focusing on the cognitive underpinnings of the classification. The 1D-CNN achieved an overall accuracy of 81% (Macro AUC = 0.96), while the BiLSTM reached 78% (Macro AUC = 0.95). Despite the architectural differences, both models demonstrated a robust relationship between prediction accuracy and individual cognitive performance (p < 0.05 for 1D-CNN, and p < 0.001 for BiLSTM), with lower classification accuracy observed in individuals with poorer task performance. Feature importance analysis highlighted the dominance of visual networks, suggesting that task-driven state differences are primarily encoded in visual processing. Attention and control networks also showed relatively high importance. We observed individual trait-based effects and subtle model-specific differences: 1D-CNN yielded slightly better overall performance, while BiLSTM showed better sensitivity for individual behavior. This study highlights the application of interpretable DNNs in revealing cognitive mechanisms associated with task performance and individual variability.This research was supported by the U.S. DEVCOM Army Research Laboratory through mission funding (JOG), army educational outreach program contract # W911SR-15-2-0001 (KB), and grant # W911NF2120108 (MK, JB). The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the US DEVCOM Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.https://www.nature.com/articles/s41598-025-05690-
Managing cybersecurity in local governments: 2022
No full textThis paper, based on data from our second nationwide survey of cybersecurity among local or grassroots governments in the U.S., examines how these governments manage this important function. As we have shown elsewhere, cybersecurity among local governments is increasingly important because these governments are under constant or nearly constant cyberattack. Due to the frequency of cyberattacks, as well as the probability that at least some attacks will succeed and cause damage to local government information systems, these governments have great responsibility to protect their information assets. This, in turn, requires these governments to manage cybersecurity effectively, something our data show is largely absent at the American grassroots because, on average, local governments fail in to manage cybersecurity well. After discussing our findings, we conclude and make recommendations for ways to improve local government cybersecurity management.https://digitalcommons.kennesaw.edu/jcerp/vol2025/iss1/
Global linearization without hyperbolicity
No full textWe give a proof of an extension of the Hartman-Grobman theorem to nonhyperbolic but asymptotically stable equilibria of vector fields. Moreover, the linearizing topological conjugacy is (i) defined on the entire basin of attraction if the vector field is complete, and (ii) a C superscript (k ≥ 1) diffeomorphism on the complement of the equilibrium if the vector field is
C (superscript k) and the underlying space is not 5-dimensional. We also show that the C (superscript k) statement in the 5-dimensional case is equivalent to the 4-dimensional smooth Poincaré conjecture.This material is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-24-1-0299 to Kvalheim and award number AFOSR FA9550-21-1-0289 to Sontag.https://www.sciencedirect.com/science/article/pii/S016769112500145
Evaluation and Intercomparison of Multiple Dust Emission Schemes within the NASA Goddard Earth Observing System Model
No full text105th American Meteorological Society (AMS) Annual Meeting, New Orleans, LA, US, January 12 - 16, 2025https://ntrs.nasa.gov/citations/2025000090