Magellan probes Venus' surface by 12.6-cm-wavelength vertical and oblique radar scattering and measures microwave thermal emission. Emissivity and root-meansquare slope maps between 330 degrees and 30 degrees E and 90 degrees N and 80 degrees S are dissimilar, although some local features are exceptions. Inferred surface emissivities typically are approximately 0.85, but vary from approximately 0.35 at Maxwell to approximately 0.95 northeast of Gula Mons and other locations. Lowest emissivities appear in topographically high areas; this relation suggests that a phase change or differences in chemical weathering occur at about 6055-kilometer radius. Initial results indicate that there are significant variations in the surface scattering function.
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http://dx.doi.org/10.1126/science.252.5003.265 | DOI Listing |
JMIR Med Inform
January 2025
Department of Systems Design Engineering, Faculty of Engineering, University of Waterloo, Waterloo, ON, Canada.
Background: While expert optometrists tend to rely on a deep understanding of the disease and intuitive pattern recognition, those with less experience may depend more on extensive data, comparisons, and external guidance. Understanding these variations is important for developing artificial intelligence (AI) systems that can effectively support optometrists with varying degrees of experience and minimize decision inconsistencies.
Objective: The main objective of this study is to identify and analyze the variations in diagnostic decision-making approaches between novice and expert optometrists.
AIDS Care
January 2025
Department of Knowledge Management, Sociedad Integral de Especialistas en Salud (SIES Salud IPS), Bogotá, Colombia.
The most significant progress in addressing the HIV/AIDS epidemic has been the development of antiretroviral therapy (ART). However, ensuring a high degree of treatment adherence is necessary to prevent resistance and disease progression. We conducted a cross-sectional study to evaluate adherence to ART through the calculation of the medication possession ratio (MPR) and to identify risk factors for suboptimal adherence in a cohort of HIV-positive patients receiving care at a Colombian healthcare institution across 16 cities.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Tulane University, Department of Physics and Engineering Physics, New Orleans, Louisiana 70118, USA.
The coupling between defects and extended critical degrees of freedom gives rise to the intriguing theory known as defect conformal field theory (CFT). In this work, we introduce a novel family of boundary and interface CFTs by coupling N Majorana chains with SYK_{q} interactions at the defect. Our analysis reveals that the interaction with q=2 constitutes a new marginal defect.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Quantinuum, 303 S. Technology Court, Broomfield, Colorado 80021, USA.
Although quantum mechanics underpins the microscopic behavior of all materials, its effects are often obscured at the macroscopic level by thermal fluctuations. A notable exception is a zero-temperature phase transition, where scaling laws emerge entirely due to quantum correlations over a diverging length scale. The accurate description of such transitions is challenging for classical simulation methods of quantum systems, and is a natural application space for quantum simulation.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Instituto de Ciencia de Materiales de Madrid, CSIC, E-28049 Madrid, Spain.
We address the precise determination of the phase diagram of magic angle twisted bilayer graphene under hydrostatic pressure within a self-consistent Hartree-Fock method in real space, including all the remote bands of the system. We further present a novel algorithm that maps the full real-space density matrix to a 4×4 density matrix based on a SU(4) symmetry of sublattice and valley degrees of freedom. We find a quantum critical point between a nematic and a Kekulé phase, and show also that our microscopic approach displays a strong particle-hole asymmetry in the weak coupling regime.
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