How can we localize the source of diffusion in a complex network? Because of the tremendous size of many real networks-such as the internet or the human social graph-it is usually unfeasible to observe the state of all nodes in a network. We show that it is fundamentally possible to estimate the location of the source from measurements collected by sparsely placed observers. We present a strategy that is optimal for arbitrary trees, achieving maximum probability of correct localization. We describe efficient implementations with complexity O(N(α)), where α=1 for arbitrary trees and α=3 for arbitrary graphs. In the context of several case studies, we determine how localization accuracy is affected by various system parameters, including the structure of the network, the density of observers, and the number of observed cascades.
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http://dx.doi.org/10.1103/PhysRevLett.109.068702 | DOI Listing |
J Am Chem Soc
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Hydrogen spillover is an important process in catalytic hydrogenation reactions, facilitating H activation and modulating surface chemistry of reducible oxide catalysts. This study focuses on the unveiling of platinum-induced hydrogen spillover on monoclinic tungsten trioxide (γ-WO), employing ambient pressure X-ray photoelectron spectroscopy, density functional theory calculations and microkinetic modeling to investigate the dynamic evolution of surface states at varied temperatures. At room temperature, hydrogen spillover results in the formation of W and hydrogen intermediates (hydroxyl species and adsorbed water), facilitated by Pt metal clusters.
View Article and Find Full Text PDFInvest Radiol
January 2025
From the Department of Radiology, Stanford University, Stanford, CA (K.W., M.J.M., A.M.L., A.B.S., A.J.H., D.B.E., R.L.B.); Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA (K.W.); GE HealthCare, Houston, TX (X.W.); GE HealthCare, Boston, MA (A.G.); and GE HealthCare, Menlo Park, CA (P.L.).
Objectives: Pancreatic diffusion-weighted imaging (DWI) has numerous clinical applications, but conventional single-shot methods suffer from off resonance-induced artifacts like distortion and blurring while cardiovascular motion-induced phase inconsistency leads to quantitative errors and signal loss, limiting its utility. Multishot DWI (msDWI) offers reduced image distortion and blurring relative to single-shot methods but increases sensitivity to motion artifacts. Motion-compensated diffusion-encoding gradients (MCGs) reduce motion artifacts and could improve motion robustness of msDWI but come with the cost of extended echo time, further reducing signal.
View Article and Find Full Text PDFNeuroimage Rep
December 2024
Department of Pediatrics, Division of Developmental-Behavioral Pediatrics, Stanford University, Stanford, CA, USA.
Background: Severe neonatal inflammatory conditions in very preterm infants (VPT: <32 weeks gestational age, GA) are linked to adverse neurodevelopmental outcomes. Differences in white matter (WM) microstructure of the corpus callosum (CC) have been observed at age 6 in VPT children with a history of severe neonatal inflammation. The goal of this study was to determine whether these CC differences can be detected at term-equivalent age using diffusion MRI (dMRI), and whether neonatal inflammation is associated with altered WM in additional tracts implicated in the encephalopathy of prematurity.
View Article and Find Full Text PDFCureus
December 2024
Oral Medicine and Radiology, SRM Kattankulathur Dental College and Hospital, SRM Institute of Science and Technology (SRMIST), Chennai, IND.
Dentistry still faces difficulties in diagnosing oral precancer and cancer, especially when it comes to early phase changes or disease detection, evaluation, and treatment. In essence, oral lumenography is the process of identifying oral lesions using a chemiluminescent light source and a toluidine blue labeling system. Since neoplastic epithelial cells have a changed nuclear-cytoplasmic ratio, acetic acid dehydration brings out this nuclear density and gives the tissue an "acetowhite" look.
View Article and Find Full Text PDF<b>Background and Objective:</b> Amid the escalating challenge of antibiotic resistance, the exploration of new sources has become essential, with plants serving as a promising reservoir of bioactive compounds. <i>Cannabis sativa</i> has attracted significant research interest for its antimicrobial properties and broad applications in medicine, industry and nutrition. This study aimed to investigate the antibacterial activity of ethanolic extracts from the stems and leaves of the Hang Kra Rog Phu Phan ST1 strain against twelve human pathogenic bacteria.
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