Misinformation occurs when people hold incorrect factual beliefs and do so confidently. The problem, first conceptualized by Kuklinski and colleagues in 2000, plagues political systems and is exceedingly difficult to correct. In this review, we assess the empirical literature on political misinformation in the United States and consider what scholars have learned since the publication of that early study. We conclude that research on this topic has developed unevenly. Over time, scholars have elaborated on the psychological origins of political misinformation, and this work has cumulated in a productive way. By contrast, although there is an extensive body of research on how to correct misinformation, this literature is less coherent in its recommendations. Finally, a nascent line of research asks whether people's reports of their factual beliefs are genuine or are instead a form of partisan cheerleading. Overall, scholarly research on political misinformation illustrates the many challenges inherent in representative democracy.

This paper presents a flexible radiofrequency filter with a central frequency of 2.4 GHz based on film bulk acoustic wave resonators (FBARs). The flexible filter consists of five air-gap type FBARs, each comprised of an aluminum nitride piezoelectric thin film sandwiched between two thin-film electrodes. By transfer printing the inorganic film structure from a silicon wafer to an ultrathin polyimide substrate, high electrical performance and mechanical flexibility are achieved. The filter has a peak insertion loss of -1.14 dB, a 3 dB bandwidth of 107 MHz, and a temperature coefficient of frequency of -27 ppm °C . The passband and roll-off characteristics of the flexible filter are comparable with silicon-based commercial products. No electrical performance degradation and mechanical failure occur under bending tests with a bending radius of 2.5 mm or after 100 bending cycles. The flexible FBAR filters are believed to be promising candidates for future flexible wireless communication systems.

This paper presents an experimental study on the parameters that determine the thermal performance of sintered copper wicks with longitudinal micro grooves for heat pipe applications. The grooves, which provide passages to vent vapor, have a width in a range from 150 μm to 500 μm. The copper powder used here has a nominal diameter of 50 μm, which produces an effective pore radius of approximately 13 μm. The main wicks composed of pores and grooves present characteristics of bi-dispersed wick structures. Unlike traditional bi-dispersed wick structures, the sintered grooved wick structures provide undisrupted longitudinal liquid delivery passages and thus improve the boiling limit. Performance of the wick structures with distilled water was examined and the effects of the heat flux and groove geometries on the evaporation/boiling heat transfer performance were studied.

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Abstract. We present the first experimental result of direct delineation of the nuclei of living rat bladder epithelium with ultrahigh-resolution optical coherence tomography ͑uOCT͒. We demonstrate that the cellular details embedded in the speckle noise in a uOCT image can be uncovered by time-lapse frame averaging that takes advantage of the micromotion in living biological tissue. The uOCT measurement of the nuclear size ͑7.9± 1.4 m͒ closely matches the histological evaluation ͑7.2± 0.8 m͒. Unlike optical coherence microscopy ͑OCM͒, which requires a sophisticated high-NA microscopic objective, this approach uses a commercial-grade single achromatic lens ͑f /10 mm, NA/0.25͒ and provides a cross-sectional image over 0.6 mm of depth without focus tracking, thus holding great promise of endoscopic optical biopsy for diagnosis and grading of flat epithelial cancer such as carcinoma in situ in vivo. Noninvasive in vivo imaging identification of pathogenesis at cellular resolutions is crucial to early clinical diagnosis of cancers.1 Technological advance in confocal microscopy and endoscopy has permitted noninvasive imaging of cellular morphology in intact tissue such as skin and bladder, colon, and cervical epthelia, but imaging depth is limited to 100 to 300 m and focus-tracking is required, which is difficult in many clinical applications. Unlike confocal microscopy, the lateral and axial resolutions of optical coherence tomography ͑OCT͒ are decoupled, 2 e.g., the axial resolution is determined by the source coherence length L c =2 ln 2/ 2 / ⌬, where and ⌬ are the source central wavelength and full-width half maximum ͑FWHM͒ spectral bandwidth. Therefore, the axial sectioning resolution of OCT can be substantially improved by employing broadband sources, and subcellular imaging of low-scattering tissue such as xenopus laevis ͑mesenchymal cells͒ in vivo has been reported. 1,2 However, for mammalian epithelial cells, the smaller cell size and thus denser microorganelle content results in increased cellular scattering, leading to phase randomization, i.e., speckle noise, that may drastically degrade the image contrast and resolution for imaging subcellular details. For instance, ultrahigh-resolution OCT ͑uOCT͒ with axial resolution exceeding 0.7 m has been reported, 2 but imaging of subcellular details of the epithelium remains unsolved, preventing this promising technique from becoming an optical biopsy tool for clinical diagnosis. In this letter, we demonstrate that the subcellular details of living rat urothelium can be uncovered after proper time-lapse dynamic averaging to minimize speckle noise in uOCT imaging. Figure 1 is a schematic of the time-domain uOCT setup used in this study. A Ti:Sapphire laser ͑⌬ = 128 nm͒ was used to illuminate a wavelength-flattened broadband fiberoptic Michelson interferometer. In the sample arm, light was collimated to 4.7 mm by a fiberoptic achromatic lens, scanned laterally by a 8-mm servo mirror, and focused onto biological tissue under examination by a commercial-grade achromati...