Atmospheric muography for imaging and monitoring tropic cyclones

Large-scale solid bodies on Earth such as volcanoes and man-made pyramids have been visualized with solid earth muography, and the recently invented technique, acqueous muography, has already demonstrated its capability to visualize ocean tides and tsunami. In this work, atmospheric muography, a technique to visualize and monitor the vertical profile of tropic cyclones (TCs) is presented for the first time. The density distribution and time-dependent behavior of several TCs which had approached Kagoshima, Japan, has been investigated with muography. The resultant time-sequential images captured their warm cores, and their movements were consistent with the TC trails and barometric pressure variations observed at meteorological stations. By combining multidirectional muographic images with barometric data, we anticipate that muography will become a useful tool to monitor the three-dimensional density distribution of a targeted mesoscale convective system

First navigation with wireless muometric navigation system (MuWNS) in indoor and underground environments

Summary: Navigation in indoor and underground environments has been extensively studied to realize automation of home, hospital, office, factory and mining services, and various techniques have been proposed for its implementation. By utilizing the relativistic and penetrative nature of cosmic-ray muons, a completely new wireless navigation technique called wireless muometric navigation system (MuWNS) was developed. This paper shows the results of the world’s first physical demonstration of MuWNS used on the basement floor inside a building to navigate (a person) in an area where global navigation satellite system (GNSS)/ global positioning system (GPS) signals cannot reach. The resultant navigation accuracy was comparable or better than the positioning accuracy attainable with single-point GNSS/GPS positioning in urban areas. With further improvements in stability of local clocks used for timing, it is anticipated that MuWNS can be adapted to improve autonomous mobile robot navigation and positioning as well as other underground and underwater practical applications

Atmospheric muography for imaging and monitoring tropic cyclones

Large-scale solid bodies on Earth such as volcanoes and man-made pyramids have been visualized with solid earth muography, and the recently invented technique, acqueous muography, has already demonstrated its capability to visualize ocean tides and tsunami. In this work, atmospheric muography, a technique to visualize and monitor the vertical profile of tropic cyclones (TCs) is presented for the first time. The density distribution and time-dependent behavior of several TCs which had approached Kagoshima, Japan, has been investigated with muography. The resultant time-sequential images captured their warm cores, and their movements were consistent with the TC trails and barometric pressure variations observed at meteorological stations. By combining multidirectional muographic images with barometric data, we anticipate that muography will become a useful tool to monitor the three-dimensional density distribution of a targeted mesoscale convective system

Postsynaptic assembly induced by neurexin-neuroligin interaction and neurotransmitter

Presynaptic and postsynaptic differentiation occurs at axodendritic contacts between CNS neurons. Synaptic adhesion mediated by synaptic cell adhesion molecule (SynCAM) and β-neurexins/neuroligins triggers presynaptic differentiation. The signals that trigger postsynaptic differentiation are, however, unknown. Here we report that β-neurexin expressed in nonneuronal cells induced postsynaptic density (PSD)-95 clustering in contacting dendrites of hippocampal neurons. The effect is specific to β-neurexin and was not observed with other synaptic cell adhesion molecules such as N-cadherin or SynCAM. NMDA receptors, but not α-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate receptors (AMPARs), were recruited to this β-neurexin-induced PSD-95 scaffold. Remarkably, AMPARs were inserted into this scaffold upon glutamate application or expression of a constitutively active form of calmodulin kinase II in neurons. Expression of a dominant-negative neuroligin-1 in cultured neurons markedly reduced the sizes and densities of PSD-95 puncta and AMPAR clusters. In addition, excitatory, but not inhibitory, synaptic functions were impaired in these neurons, confirming that PSD-95/neuroligin-1 interaction is involved in postsynaptic assembly at glutamatergic synapses. These results demonstrate that postsynaptic assembly of the glutamatergic synapse may be initiated by presynaptic β-neurexin and that glutamate release also is required for maturation of synapses

The Ectomycorrhizal Fungus Laccaria bicolor Produces Lipochitooligosaccharides and Uses the Common Symbiosis Pathway to Colonize Populus Roots

International audienceMycorrhizal fungi form mutualistic associations with the roots of most land plants and provide them with mineral nutrients from the soil in exchange for fixed carbon derived from photosynthesis. The common symbiosis pathway (CSP) is a conserved molecular signaling pathway in all plants capable of associating with arbuscular mycorrhizal fungi. It is required not only for arbuscular mycorrhizal symbiosis but also for rhizobia-legume and actinorhizal symbioses. Given its role in such diverse symbiotic associations, we hypothesized that the CSP also plays a role in ectomycorrhizal associations. We showed that the ectomycorrhizal fungus Laccaria bicolor produces an array of lipochitooligosaccharides (LCOs) that can trigger both root hair branching in legumes and, most importantly, calcium spiking in the host plant Populus in a CASTOR/POLLUX-dependent manner. Nonsulfated LCOs enhanced lateral root development in Populus in a calcium/calmodulin-dependent protein kinase (CCaMK)-dependent manner, and sulfated LCOs enhanced the colonization of Populus by L. bicolor. Compared with the wildtype Populus, the colonization of CASTOR/POLLUX and CCaMK RNA interference lines by L. bicolor was reduced. Our work demonstrates that similar to other root symbioses, L. bicolor uses the CSP for the full establishment of its mutualistic association with Populus

Muography as a new complementary tool in monitoring volcanic hazard:implications for early warning systems

Abstract Muography uses muons naturally produced in the interactions between cosmic rays and atmosphere for imaging and characterization of density differences and time-sequential changes in solid (e.g. rocks) and liquid (e.g. melts ± dissolved gases) materials in scales from tens of metres to up to a few kilometres. In addition to being useful in discovering the secrets of the pyramids, ore prospecting and surveillance of nuclear sites, muography successfully images the internal structure of volcanoes. Several field campaigns have demonstrated that muography can image density changes relating to magma ascent and descent, magma flow rate, magma degassing, the shape of the magma body, an empty conduit diameter, hydrothermal activity and major fault lines. In addition, muography is applied for long-term volcano monitoring in a few selected volcanoes around the world. We propose using muography in volcano monitoring in conjunction with other existing techniques for predicting volcanic hazards. This approach can provide an early indication of a possible future eruption and potentially the first estimate of its scale by producing direct evidence of magma ascent through its conduit in real time. Knowing these issues as early as possible buy critically important time for those responsible for the local alarm and evacuation protocols

Muography

International audienceMuography takes advantage of the specific properties of cosmic-raymuons, relativistic leptons that are much heavier than electrons.Cosmic-ray muons have strong penetrating power and a relativisticnature, which means they can be used in a range of technologies,including imagery; positioning, navigation, timing (PNT); and securedcommunication in environments where conventional techniques areunavailable. As cosmic-ray muons are universally present on Earth,muographic measurements can be conducted in the same manneracross the globe. Similar results have been produced independent ofwhere measurements were taken. This has enabled the muographicfield to grow and develop into a powerful tool for investigating naturalphenomena, cultural heritage and PNT. This Primer is intended as anintroductory article that introduces new and established muographictechniques. Case studies are provided, with examples from recentinterdisciplinary advances. Data reproducibility and limitations arediscussed, before finishing with an outlook of future developments

Muographic Detection of Seasonal Variations in Astronomical Tides With Hyper Kilometric Submarine Deep Detector (HKMSDD)

Tidal amplification or tidal reduction as a response to sea-level variations can potentially amplify or mitigate the flood risk associated with future sea-level rise caused by global climate change. Tokyo Bay Seafloor Hyper Kilometric Submarine Deep Detector (TS-HKMSDD), the world’s first detector array located underneath the seafloor, has operated without intermittency for more than one year collecting cosmic-ray muon data, which revealed the seasonal variations in astronomical tides in Tokyo Bay. By comparing onshore tide gauge seasonal mean sea level data with offshore-subseafloor TS-HKMSDD data, it was found that seasonal water level rises in Tokyo Bay played a negative role in the local tidal amplification, indicating that future sea-level rise may potentially mitigate the flood risk in the Tokyo Bay area. With its cosmic sensors, which can monitor aquatic environments without requiring them to be in direct contact with water and in conjunction with the availability of globally increasing urban underground spaces (UUS) for installation (including pre-existing underwater tunnels and commercial buildings that offer reliable utilities in coastal areas) we anticipate that the robustness and versatility of HKMSDD as a long-term stable tide monitor will make it a world standard measurement tool for coastal tide monitoring to complement pre-existing tide gauge stations worldwide

First results of undersea muography with the Tokyo-Bay Seafloor Hyper-Kilometric Submarine Deep Detector

Abstract Tidal measurements are of great significance since they may provide us with essential data to apply towards protection of coastal communities and sea traffic. Currently, tide gauge stations and laser altimetry are commonly used for these measurements. On the other hand, muography sensors can be located underneath the seafloor inside an undersea tunnel where electric and telecommunication infrastructures are more readily available. In this work, the world’s first under-seafloor particle detector array called the Tokyo-bay Seafloor Hyper-Kilometric Submarine Deep Detector (TS-HKMSDD) was deployed underneath the Tokyo-Bay seafloor for conducting submarine muography. The resultant 80-day consecutive time-sequential muographic data were converted to the tidal levels based on the parameters determined from the first-day astronomical tide height (ATH) data. The standard deviation between ATH and muographic results for the rest of a 79-day measurement period was 12.85 cm. We anticipate that if the length of the TS-HKMSDD is extended from 100 m to a full-scale as large as 9.6 km to provide continuous tidal information along the tunnel, this muography application will become an established standard, demonstrating its effectiveness as practical tide monitor for this heavy traffic waterway in Tokyo and in other important sea traffic areas worldwide