Cyclic lava effusion during the 2018 eruption of Kilauea Volcano
Lava flows present a recurring threat to communities on active volcanoes, and volumetric eruption rate is one of the primary factors controlling flow behavior and hazard. The time scales and driving forces of eruption rate variability, however, remain poorly understood. In 2018, a highly destructive eruption occurred on the lower flank of Kīlauea Volcano, Hawai‘i, where the primary vent exhibited substantial cyclic eruption rates on both short (minutes) and long (tens of hours) time scales. We used multiparameter data to show that the short cycles were driven by shallow outgassing, whereas longer cycles were pressur...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Patrick, M. R., Dietterich, H. R., Lyons, J. J., Diefenbach, A. K., Parcheta, C., Anderson, K. R., Namiki, A., Sumita, I., Shiro, B., Kauahikaua, J. P. Tags: Geochemistry, Geophysics, Online Only r-articles Source Type: news
Response to Comment on "The role of electron-electron interactions in two-dimensional Dirac fermions"
Hesselmann et al. question one of our conclusions: the suppression of Fermi velocity at the Gross-Neveu critical point for the specific case of vanishing long-range interactions and at zero energy. The possibility they raise could occur in any finite-size extrapolation of numerical data. Although we cannot definitively rule out this possibility, we provide mathematical bounds on its likelihood. (Source: ScienceNOW)
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Tang, H.-K., Leaw, J. N., Rodrigues, J. N. B., Herbut, I. F., Sengupta, P., Assaad, F. F., Adam, S. Tags: Physics t-comment Source Type: news
Targeted selection of HIV-specific antibody mutations by engineering B cell maturation
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Saunders, K. O., Wiehe, K., Tian, M., Acharya, P., Bradley, T., Alam, S. M., Go, E. P., Scearce, R., Sutherland, L., Henderson, R., Hsu, A. L., Borgnia, M. J., Chen, H., Lu, X., Wu, N. R., Watts, B., Jiang, C., Easterhoff, D., Cheng, H.-L., McGovern, K., Tags: Biochemistry, Immunology, Online Only r-articles Source Type: news
Comment on "The role of electron-electron interactions in two-dimensional Dirac fermions"
Tang et al. (Research Articles, 10 August 2018, p. 570) report on the properties of Dirac fermions with both on-site and Coulomb interactions. The substantial decrease, up to ~40%, of the Fermi velocity of Dirac fermions with on-site interaction is inconsistent with the numerical data near the Gross-Neveu quantum critical point. This results from an inappropriate finite-size extrapolation. (Source: ScienceNOW)
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Hesselmann, S., Lang, T. C., Schuler, M., Wessel, S., Läuchli, A. M. Tags: Online Only, Physics t-comment Source Type: news
A generalized HIV vaccine design strategy for priming of broadly neutralizing antibody responses
Vaccine induction of broadly neutralizing antibodies (bnAbs) to HIV remains a major challenge. Germline-targeting immunogens hold promise for initiating the induction of certain bnAb classes; yet for most bnAbs, a strong dependence on antibody heavy chain complementarity-determining region 3 (HCDR3) is a major barrier. Exploiting ultradeep human antibody sequencing data, we identified a diverse set of potential antibody precursors for a bnAb with dominant HCDR3 contacts. We then developed HIV envelope trimer–based immunogens that primed responses from rare bnAb-precursor B cells in a mouse model and bound a range of ...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Steichen, J. M., Lin, Y.-C., Havenar-Daughton, C., Pecetta, S., Ozorowski, G., Willis, J. R., Toy, L., Sok, D., Liguori, A., Kratochvil, S., Torres, J. L., Kalyuzhniy, O., Melzi, E., Kulp, D. W., Raemisch, S., Hu, X., Bernard, S. M., Georgeson, E., Phelps Tags: Biochemistry, Immunology, Online Only r-articles Source Type: news
Episodes of particle ejection from the surface of the active asteroid (101955) Bennu
We report repeated instances of particle ejection from the surface of (101955) Bennu, demonstrating that it is an active asteroid. The ejection events were imaged by the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) spacecraft. For the three largest observed events, we estimated the ejected particle velocities and sizes, event times, source regions, and energies. We also determined the trajectories and photometric properties of several gravitationally bound particles that orbited temporarily in the Bennu environment. We consider multiple hypotheses for the mech...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Lauretta, D. S., Hergenrother, C. W., Chesley, S. R., Leonard, J. M., Pelgrift, J. Y., Adam, C. D., Al Asad, M., Antreasian, P. G., Ballouz, R.- L., Becker, K. J., Bennett, C. A., Bos, B. J., Bottke, W. F., Brozovic, M., Campins, H., Connolly, H. C., Daly Tags: Astronomy, Online Only, Planetary Science r-articles Source Type: news
Joint statement on EPA proposed rule and public availability of data (2019)
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Thorp, H. H., Skipper, M., Kiermer, V., Berenbaum, M., Sweet, D., Horton, R. Tags: letters Source Type: news
Magma reservoir failure and the onset of caldera collapse at Kilauea Volcano in 2018
Caldera-forming eruptions are among Earth’s most hazardous natural phenomena, yet the architecture of subcaldera magma reservoirs and the conditions that trigger collapse are poorly understood. Observations from the formation of a 0.8–cubic kilometer basaltic caldera at Kīlauea Volcano in 2018 included the draining of an active lava lake, which provided a window into pressure decrease in the reservoir. We show that failure began after
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Anderson, K. R., Johanson, I. A., Patrick, M. R., Gu, M., Segall, P., Poland, M. P., Montgomery-Brown, E. K., Miklius, A. Tags: Geochemistry, Geophysics, Online Only r-articles Source Type: news
Structures of the AMPA receptor in complex with its auxiliary subunit cornichon
In the brain, AMPA-type glutamate receptors (AMPARs) form complexes with their auxiliary subunits and mediate the majority of fast excitatory neurotransmission. Signals transduced by these complexes are critical for synaptic plasticity, learning, and memory. The two major categories of AMPAR auxiliary subunits are transmembrane AMPAR regulatory proteins (TARPs) and cornichon homologs (CNIHs); these subunits share little homology and play distinct roles in controlling ion channel gating and trafficking of AMPAR. Here, I report high-resolution cryo–electron microscopy structures of AMPAR in complex with CNIH3. Contrary...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Nakagawa, T. Tags: Biochemistry, Neuroscience reports Source Type: news
Design of an in vitro biocatalytic cascade for the manufacture of islatravir
We report an in vitro biocatalytic cascade synthesis of the investigational HIV treatment islatravir. Five enzymes were engineered through directed evolution to act on non-natural substrates. These were combined with four auxiliary enzymes to construct islatravir from simple building blocks in a three-step biocatalytic cascade. The overall synthesis requires fewer than half the number of steps of the previously reported routes. (Source: ScienceNOW)
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Huffman, M. A., Fryszkowska, A., Alvizo, O., Borra-Garske, M., Campos, K. R., Canada, K. A., Devine, P. N., Duan, D., Forstater, J. H., Grosser, S. T., Halsey, H. M., Hughes, G. J., Jo, J., Joyce, L. A., Kolev, J. N., Liang, J., Maloney, K. M., Mann, B. F Tags: Chemistry reports Source Type: news
Functional diversity of human intrinsically photosensitive retinal ganglion cells
In this study, we used a human organ donor preparation method to measure human ipRGCs’ photoresponses. We discovered three functional ipRGC subtypes with distinct sensitivities and responses to light. The response of one ipRGC subtype appeared to depend on exogenous chromophore supply, and this response is conserved in both human and mouse retinas. Rods and cones also provided input to ipRGCs; however, each subtype integrated outer retina light signals in a distinct fashion. (Source: ScienceNOW)
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Mure, L. S., Vinberg, F., Hanneken, A., Panda, S. Tags: Medicine, Diseases, Neuroscience reports Source Type: news
Embryonal precursors of Wilms tumor
Adult cancers often arise from premalignant clonal expansions. Whether the same is true of childhood tumors has been unclear. To investigate whether Wilms tumor (nephroblastoma; a childhood kidney cancer) develops from a premalignant background, we examined the phylogenetic relationship between tumors and corresponding normal tissues. In 14 of 23 cases studied (61%), we found premalignant clonal expansions in morphologically normal kidney tissues that preceded tumor development. These clonal expansions were defined by somatic mutations shared between tumor and normal tissues but absent from blood cells. We also found hyper...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Coorens, T. H. H., Treger, T. D., Al-Saadi, R., Moore, L., Tran, M. G. B., Mitchell, T. J., Tugnait, S., Thevanesan, C., Young, M. D., Oliver, T. R. W., Oostveen, M., Collord, G., Tarpey, P. S., Cagan, A., Hooks, Y., Brougham, M., Reynolds, B. C., Barone, Tags: Development, Medicine, Diseases reports Source Type: news
Transmitting the quantum state of electrons across a metallic island with Coulomb interaction
The Coulomb interaction generally limits the quantum propagation of electrons. However, it can also provide a mechanism to transfer their quantum state over larger distances. Here, we demonstrate such a form of electron teleportation across a metallic island. This effect originates from the low-temperature freezing of the island’s charge which, in the presence of a single connected electronic channel, enforces a one-to-one correspondence between incoming and outgoing electrons. Such faithful quantum state imprinting is established between well-separated injection and emission locations and evidenced through two-path ...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Duprez, H., Sivre, E., Anthore, A., Aassime, A., Cavanna, A., Gennser, U., Pierre, F. Tags: Physics reports Source Type: news
Ultrafast stimulated emission microscopy of single nanocrystals
Single-molecule detection is a powerful method used to distinguish different species and follow time trajectories within the ensemble average. However, such detection capability requires efficient emitters and is prone to photobleaching, and the slow, nanosecond spontaneous emission process only reports on the lowest excited state. We demonstrate direct detection of stimulated emission from individual colloidal nanocrystals at room temperature while simultaneously recording the depleted spontaneous emission, enabling us to trace the carrier population through the entire photocycle. By capturing the femtosecond evolution of...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Piatkowski, L., Accanto, N., Calbris, G., Christodoulou, S., Moreels, I., van Hulst, N. F. Tags: Physics, Applied, Physics reports Source Type: news
Extinction filters mediate the global effects of habitat fragmentation on animals
Habitat loss is the primary driver of biodiversity decline worldwide, but the effects of fragmentation (the spatial arrangement of remaining habitat) are debated. We tested the hypothesis that forest fragmentation sensitivity—affected by avoidance of habitat edges—should be driven by historical exposure to, and therefore species’ evolutionary responses to disturbance. Using a database containing 73 datasets collected worldwide (encompassing 4489 animal species), we found that the proportion of fragmentation-sensitive species was nearly three times as high in regions with low rates of historical disturbanc...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Betts, M. G., Wolf, C., Pfeifer, M., Banks-Leite, C., Arroyo-Rodriguez, V., Ribeiro, D. B., Barlow, J., Eigenbrod, F., Faria, D., Fletcher, R. J., Hadley, A. S., Hawes, J. E., Holt, R. D., Klingbeil, B., Kormann, U., Lens, L., Levi, T., Medina-Rangel, G. Tags: Ecology reports Source Type: news
Direct determination of mode-projected electron-phonon coupling in the time domain
Ultrafast spectroscopies have become an important tool for elucidating the microscopic description and dynamical properties of quantum materials. In particular, by tracking the dynamics of nonthermal electrons, a material’s dominant scattering processes can be revealed. Here, we present a method for extracting the electron-phonon coupling strength in the time domain, using time- and angle-resolved photoemission spectroscopy (TR-ARPES). This method is demonstrated in graphite, where we investigate the dynamics of photoinjected electrons at the point, detecting quantized energy-loss processes that correspond to the emi...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Na, M. X., Mills, A. K., Boschini, F., Michiardi, M., Nosarzewski, B., Day, R. P., Razzoli, E., Sheyerman, A., Schneider, M., Levy, G., Zhdanovich, S., Devereaux, T. P., Kemper, A. F., Jones, D. J., Damascelli, A. Tags: Physics reports Source Type: news
Electrical and optical control of single spins integrated in scalable semiconductor devices
Spin defects in silicon carbide have the advantage of exceptional electron spin coherence combined with a near-infrared spin-photon interface, all in a material amenable to modern semiconductor fabrication. Leveraging these advantages, we integrated highly coherent single neutral divacancy spins in commercially available p-i-n structures and fabricated diodes to modulate the local electrical environment of the defects. These devices enable deterministic charge-state control and broad Stark-shift tuning exceeding 850 gigahertz. We show that charge depletion results in a narrowing of the optical linewidths by more than 50-fo...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Anderson, C. P., Bourassa, A., Miao, K. C., Wolfowicz, G., Mintun, P. J., Crook, A. L., Abe, H., Ul Hassan, J., Son, N. T., Ohshima, T., Awschalom, D. D. Tags: Physics, Applied, Materials Science r-articles Source Type: news
Stem cell-driven lymphatic remodeling coordinates tissue regeneration
Tissues rely on stem cells (SCs) for homeostasis and wound repair. SCs reside in specialized microenvironments (niches) whose complexities and roles in orchestrating tissue growth are still unfolding. Here, we identify lymphatic capillaries as critical SC-niche components. In skin, lymphatics form intimate networks around hair follicle (HF) SCs. When HFs regenerate, lymphatic–SC connections become dynamic. Using a mouse model, we unravel a secretome switch in SCs that controls lymphatic behavior. Resting SCs express angiopoietin-like protein 7 (Angptl7), promoting lymphatic drainage. Activated SCs switch to Angptl4, ...
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Gur-Cohen, S., Yang, H., Baksh, S. C., Miao, Y., Levorse, J., Kataru, R. P., Liu, X., de la Cruz-Racelis, J., Mehrara, B. J., Fuchs, E. Tags: Cell Biology r-articles Source Type: news
A childhood tumor--from the beginning
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Kiberstis, P. A. Tags: Development, Medicine, Diseases twis Source Type: news
Protecting Patagonian peatlands in Chile
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Hoyos-Santillan, J., Miranda, A., Lara, A., Rojas, M., Sepulveda-Jauregui, A. Tags: letters Source Type: news
Wind energy: An ecological challenge
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Katzner, T. E., Nelson, D. M., Diffendorfer, J. E., Duerr, A. E., Campbell, C. J., Leslie, D., Vander Zanden, H. B., Yee, J. L., Sur, M., Huso, M. M. P., Braham, M. A., Morrison, M. L., Loss, S. R., Poessel, S. A., Conkling, T. J., Miller, T. A. Tags: letters Source Type: news
Algorithms on regulatory lockdown in medicine
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Babic, B., Gerke, S., Evgeniou, T., Cohen, I. G. Tags: Medicine, Diseases, Science and Policy p-forum Source Type: news
Calderas collapse as magma flows into rifts
Source: ScienceNOW - December 5, 2019 Category: Science Authors: Sigmundsson, F. Tags: Geochemistry, Geophysics perspective Source Type: news