396 research outputs found

    Generating intravital super-resolution movies with conventional microscopy reveals actin dynamics that construct pioneer axons

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    Super-resolution microscopy is broadening our in-depth understanding of cellular structure. However, super-resolution approaches are limited, for numerous reasons, from utilization in longer-term intravital imaging. We devised a combinatorial imaging technique that combines deconvolution with stepwise optical saturation microscopy (DeSOS) to circumvent this issue and image cells in their native physiological environment. Other than a traditional confocal or two-photon microscope, this approach requires no additional hardware. Here, we provide an open-access application to obtain DeSOS images from conventional microscope images obtained at low excitation powers. We show that DeSOS can be used in time-lapse imaging to generate super-resolution movies in zebrafish. DeSOS was also validated in live mice. These movies uncover that actin structures dynamically remodel to produce a single pioneer axon in a 'top-down' scaffolding event. Further, we identify an F-actin population - stable base clusters - that orchestrate that scaffolding event. We then identify that activation of Rac1 in pioneer axons destabilizes stable base clusters and disrupts pioneer axon formation. The ease of acquisition and processing with this approach provides a universal technique for biologists to answer questions in living animals

    Status quo after one year of COVID-19 pandemic in otolaryngological hospital-based departments and private practices in Germany

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    PURPOSE: The COVID-19 pandemic has affected healthcare systems worldwide. Data on the impact on otolaryngological clinics and private practices is sparse. This study aimed to present data on healthcare worker (HCW) screening, status of HCW, pre-interventional testing, the use of personal protective equipment (PPE) and the economic impact of the pandemic. METHODS: Otolaryngological private practices and hospital-based departments were surveyed nationwide using an online questionnaire. Participating facilities were recruited via the German Society for Oto-Rhino-Laryngology and the German Association for Otolaryngologists in Bavaria. RESULTS: 365 private practices (2776 employees) and 65 hospitals (2333 employees) were included. Significantly more hospitals (68.7%) than practices (40.5%) performed pre-interventional testing in their outpatients (p < 0.00). Most inpatients were tested in practices and hospitals (100.0% and 95.0%; p = 0.08). HCW screening was performed in 73.7% of practices and in 77.3% of hospitals (p = 0.54). Significantly more HCW infections were reported in private practices (4.7%) than in hospital (3.6%; p = 0.03). The private or home environment was the most frequent source of infection among HCW in hospitals (44%) and practices (63%). The use of PPE increased over the course of the pandemic. The number of procedures and the revenue decreased in 2020. CONCLUSION: The rate of pre-interventional testing among outpatients in otolaryngological practices is low and HCW infections were found to be more frequent in practices than in hospitals. In addition, a high rate of infections in otolaryngological HCW seems to stem from the private or home environment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00405-021-06992-2

    Pre-eruptive magmatic processes re-timed using a non-isothermal approach to magma chamber dynamics

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    Open Source PaperThis work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. The attached file is the published version of the article

    Crustal-scale degassing due to magma system destabilization and magma-gas decoupling at Soufrière Hills Volcano, Montserrat

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    Activity since 1995 at Soufrière Hills Volcano (SHV), Montserrat has alternated between andesite lava extrusion and quiescence, which are well correlated with seismicity and ground deformation cycles. Large variations in SO₂ flux do not correlate with these alternations, but high and low HCl/SO₂ characterize lava dome extrusion and quiescent periods respectively. Since lava extrusion ceased (February 2010) steady SO₂ emissions have continued at an average rate of 374 tonnes/day (± 140 t/d), and incandescent fumaroles (temperatures up to 610°C) on the dome have not changed position or cooled. Occasional short bursts (over several hours) of higher (∼ 10x) SO₂ flux have been accompanied by swarms of volcano-tectonic earthquakes. Strain data from these bursts indicate activation of the magma system to depths up to 10 km. SO₂ emissions since 1995 greatly exceed the amounts that could be derived from 1.1 km³ of erupted andesite, and indicating extensive partitioning of sulfur into a vapour phase, as well as efficient decoupling and outgassing of sulfur-rich gases from the magma. These observations are consistent with a vertically extensive, crustal magmatic mush beneath SHV. Three states of the magmatic system are postulated to control degassing. During dormant periods (10³ to 10⁴ years) magmatic vapour and melts separate as layers from the mush and decouple from each other. In periods of unrest (years) without eruption, melt and fluid layers become unstable, ascend and can amalgamate. Major destabilization of the mush system leads to eruption, characterized by magma mixing and release of volatiles with different ages, compositions and sources.RSJS acknowledges an ERC advanced grant (VOLDIES). JDB acknowledges ERC advanced grant CRITMAG and a Wolfson Research Merit Award.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2015GC00579

    Law professors want hearing, vote on Garland

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    Dear Senator Fischer and Senator Sasse, We write this as citizens, but we all teach at the University of Nebraska College of Law. We hold different political viewpoints and disagree frequentIy with each other on political and legal issues. As law professors, however, we share a deep commitment to the rule of law and an impartial judiciary. We therefore urge you to hold confirmation hearings and a vote on President Obama\u27s Supreme Court nominee, Chief Judge Merrick B. Garland

    Rapid onset of mafic magmatism facilitated by volcanic edifice collapse

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    Volcanic edifice collapses generate some of Earth's largest landslides. How such unloading affects the magma storage systems is important for both hazard assessment and for determining long-term controls on volcano growth and decay. Here we present a detailed stratigraphic and petrological analyses of volcanic landslide and eruption deposits offshore Montserrat, in a subduction zone setting, sampled during Integrated Ocean Drilling Program Expedition 340. A large (6–10 km3) collapse of the Soufrière Hills Volcano at ~130 ka was followed by explosive basaltic volcanism and the formation of a new basaltic volcanic center, the South Soufrière Hills, estimated to have initiated <100 years after collapse. This basaltic volcanism was a sharp departure from the andesitic volcanism that characterized Soufrière Hills' activity before the collapse. Mineral-melt thermobarometry demonstrates that the basaltic magma's transit through the crust was rapid and from midcrustal depths. We suggest that this rapid ascent was promoted by unloading following collapse
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