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Ultra‐low frequency (ULF) waves radially diffuse hundreds‐keV to few‐MeV electrons in the magnetosphere, as the range of drift frequencies of such electrons overlaps with the wave frequencies, leading to resonant interactions. Theoretically this process is described by analytic expressions of the resonant interactions between electrons and ULF wave modes in a background magnetic field. However, most expressions of the radial diffusion rates are derived for equatorially mirroring electrons and are based on estimates of the power of ULF waves that are obtained either from spacecraft close to the equatorial plane or from the ground but mapped to the equatorial plane. Based on recent statistical in situ observations, it was found that the wave power of magnetic fluctuations is significantly enhanced away from the magnetic equator. In this study, the distribution of the wave amplitudes as a function of magnetic latitude is compared against models simulating the natural modes of oscillation of magnetospheric field lines, with which they are found to be consistent. Energetic electrons are subsequently traced in 3D model fields that include a latitudinal dependence that is similar to measurements and to the natural modes of oscillation. Particle tracing simulations show a significant dependence of the radial transport of relativistic electrons on pitch angle, with off‐equatorial electrons experiencing considerably higher radial transport, as they interact with ULF wave fluctuations of higher amplitude than equatorial electrons. These findings point to the need for incorporating pitch‐angle‐dependent radial diffusion coefficients in global radiation belt models. Plain Language Summary: The random inward and outward motion of high energy electrons in the Earth's magnetosphere, called radial diffusion, is a critical factor in modeling and predicting the state of the radiation belts, where many satellites operate. This motion is caused primarily by waves in the Ultra‐Low Frequency (or ULF) range, which have been measured and characterized since the early days of the space era. However, for simplicity, most current models treat radial diffusion in two dimensions, on the Earth's magnetic equatorial plane, taking into account the average motion of electrons as they drift around the Earth. Recent studies, enabled by multi‐year measurements by missions with off‐equatorial inclinations (THEMIS, Arase, Cluster) have shown that the power of ULF waves is significantly enhanced away from the magnetic equator. A 3D model of the magnetic field fluctuations is compared with statistical data of the measured ULF wave power, and is then used to estimate the radial transport of off‐equatorial electrons. It is found through single‐particle tracing that radial diffusion is significantly enhanced when taking into account the latitude‐dependence of ULF waves. These new findings can change the quantification and parameterization of radial diffusion and our current understanding of radial diffusion in the radiation belts. Key Points: Enhanced Ultra‐low frequency (ULF) wave power at high latitudes significantly enhances radial transport of off‐equatorial relativistic radiation belt electronsRadial diffusion coefficients need to be revisited, to include pitch angle dependence and latitude‐dependent ULF wave powerThese results are enabled by multi‐year statistics by s/c performing measurements away from the magnetic equator and by particle tracing [ABSTRACT FROM AUTHOR]

We report the results of systematic ab initio modelling of various configurations of iron and cobalt impurities embedded in the (110), (101), and (100) surfaces of anatase TiO2, with and without oxygen vacancies. The simulation results demonstrate that incorporation into interstitial voids at the surface level is significantly more favourable than other configurations for both iron and cobalt. The calculations also demonstrate the crucial effect of the facet as well as the lesser effects of other factors, such as vacancies and strain on the energetics of defect incorporation, magnetic moment, bandgap, and catalytic performance. It is further shown that there is no tendency towards the segregation or clustering of impurities on the surface. The calculated free energies of the hydrogen evolution reaction in acidic media predict that iron impurities embedded in the (101) surface of anatase TiO2 can be a competitive catalyst for this reaction. [ABSTRACT FROM AUTHOR]

This manuscript is a follow up study to Hogan et al., (2024, https://doi.org/10.1029/2023JA032221) which describes the science motivation and development of the Medium Energy Electron Telescope (MEET). Medium Energy Electron Telescope is a 1U instrument optimized to measure 30–400 keV electrons in the inner radiation belt with fine energy resolution to resolve dynamics of these populations which are not well understood. Here we present the fabrication and testing of MEET to certify its performance in preparation for in‐space measurements. Assembly of an engineering model is shown. This unit has undergone vibration testing and these results are discussed. The electronics of the instrument are tested after these environmental tests including electron measurements with pulse injection and a radioactive source. Test results indicate the instrument is viable for flight on a potential mission by satisfying noise requirements and reproduction of an input flux spectrum. The noise of expected input signals is quantified to be <∼6 keV allowing for <20% dE/E for 30 keV electrons. Strontium‐90 radioactive source tests were conducted. Using measured count rates from MEET's electron energy channels, we reproduce the strontium‐90 spectrum proving the instrument's ability to measure flux of 30–800 keV electrons with fine nominal energy resolution (<20% dE/E for <60 keV, and <10% for >60 keV electrons). These results demonstrate MEET's performance in a relevant environment via ground testing. Medium Energy Electron Telescope is available for future missions to provide novel electron measurements in the inner radiation belt. Key Points: An engineering model of the Medium Energy Electron Telescope (MEET) has been assembled and undergone mechanical and electronic testingElectronic performance tests are shown after vibration testing to demonstrate instrument viability for obtaining radiation measurementsTesting with a strontium‐90 radioactive source is conducted and the flux spectrum is reproduced using MEET's electron energy channels [ABSTRACT FROM AUTHOR]

In recent decades, developmental biologists have come to view vascular development as a series of progressive transitions. Mesoderm differentiates into endothelial cells; arteries, veins and lymphatic endothelial cells are specified from early endothelial cells; and vascular networks diversify and invade developing tissues and organs. Our understanding of this elaborate developmental process has benefitted from detailed studies using the zebrafish as a model system. Here, we review a number of key developmental transitions that occur in zebrafish during the formation of the blood and lymphatic vessel networks. [ABSTRACT FROM AUTHOR]

During active geomagnetic periods both electrons and protons in the outer radiation belt have been frequently observed to penetrate to low L (<4). Previous studies have demonstrated systematic differences in the deep penetration of the two species of particles, most notably that the penetration of protons is observed less frequently than for electrons of the same energies. A recent study by Mei et al. (2023, https://doi.org/10.1029/2022GL101921) showed that the time‐varying convection electric field contributes to the deeper penetration of low‐energy electrons and that a radial diffusion‐convection model can be used to reproduce the storm‐time penetration of lower‐energy electrons to lower L. In this study, we analyze and provide physical explanations for the different behaviors of electrons and protons in terms of their penetration depth to low L. A radial diffusion‐convection model is applied for the two species with coefficients that are adjusted according to the mass‐dependent relativistic effects on electron and proton drift velocity, and the different loss mechanisms included for each species. Electromagnetic ion cyclotron (EMIC) wave scattering losses for 100s of keV protons during a specific event are modeled and quantified; the results suggest that EMIC waves interacting with protons of lower energies than electrons can contribute to prevent the inward transport of the protons. Key Points: A bi‐particle model is established for simultaneously modeling both electron and proton energy‐dependent deep penetration to low L (<4)Relativistic effect leads to stronger diffusive and convective radial transport of electrons than protons of the same energyScattering due to electromagnetic ion cyclotron waves can prevent penetration of 100s of keV protons to low L while likely not affecting electrons of the same energy [ABSTRACT FROM AUTHOR]

The atypical cadherin FAT4 has established roles in the regulation of planar cell polarity and Hippo pathway signaling that are cell context dependent. The recent identification of FAT4 mutations in Hennekam syndrome, features of which include lymphedema, lymphangiectasia, and mental retardation, uncovered an important role for FAT4 in the lymphatic vasculature. Hennekam syndrome is also caused by mutations in collagen and calcium binding EGF domains 1 (CCBE1) and ADAM metallopeptidase with thrombospondin type 1 motif 3 (ADAMTS3), encoding a matrix protein and protease, respectively, that regulate activity of the key prolymphangiogenic VEGF-C/VEGFR3 signaling axis by facilitating the proteolytic cleavage and activation of VEGF-C. The fact that FAT4, CCBE1, and ADAMTS3 mutations underlie Hennekam syndrome suggested that all 3 genes might function in a common pathway. We identified FAT4 as a target gene of GATA-binding protein 2 (GATA2), a key transcriptional regulator of lymphatic vascular development and, in particular, lymphatic vessel valve development. Here, we demonstrate that FAT4 functions in a lymphatic endothelial cell-autonomous manner to control cell polarity in response to flow and is required for lymphatic vessel morphogenesis throughout development. Our data reveal a crucial role for FAT4 in lymphangiogenesis and shed light on the mechanistic basis by which FAT4 mutations underlie a human lymphedema syndrome., Introduction Hennekam syndrome (OMIM #235510 and #616006) is an autosomal-recessive disorder characterized by congenital lymphedema and lymphangiectasia, unusual facial morphology, attributed at least in part to intrauterine facial lymphedema, and [...]