Thus far, a perfectly secure encryption key storage system doesn't exist. As long as key storage is connected to a network system, there is always a chance that it can be cracked. Even if storage is ...not continually connected to a network system; it is repeatedly necessary for an individual to access storage to upload and download the data; hence there is always a loophole with every conventional encryption key storage system. By utilizing the penetrative nature of cosmic-ray muons, the COSMOCAT (Cosmic coding and transfer) technique may tackle this problem by eliminating the requirement for any network connection to data storage. COSMOCAT was invented as a post quantum key generation and distribution technique for wireless near field communication. However, in its first stage of development, COSMOCAT relied on standard comparators and Global Positioning System (GPS) or other Global Navigation Satellite Systems (GNSS) for key generation. Temporal jitters of the signals outputted from comparators and frequency fluctuations in GPS-disciplined oscillators degraded the key strength and the efficiency of both the key generation and distribution. New strategies are tested in this paper to improve these factors. As a result, the key strength and the key authenticating rate limit are respectively improved by 4 orders of magnitude and more than 5 orders of magnitude. As a consequence, it has become possible to propose a practical methodology for a new key storage and authentication strategy which has the potential to be an impregnable defense against any kind of cyber/physical attack to data storage. Practical applications of COSMOCATS-based symmetric-key cryptosystems to an electronic digital signing system, communication, and cloud storage are also discussed.
Accurate traceability of time is prerequisite to the proper functioning of many necessary aspects of our modern life including making financial transactions, managing automated technology and ...navigating the transport of goods and human beings. One of the most reliable international time references is the Coordinated Universal Time (UTC) that can be distributed wirelessly in principle. However, this wireless option is currently limited to GPS and other global navigation satellite systems. GPS signals are weak and easily affected by environmental conditions. Moreover, since GPS signals are unencrypted, the possibility of a signal spoofing attack remains a continuous threat. Prior works showed the potential of the alternative wireless time synchronization technique called Cosmic Time Synchronization (CTS), in which, clocks are located 50 m apart were wirelessly synchronized with a sub-microsecond level accuracy, and its operation time was limited to 20 min. However, for the actual implementation of CTS to real-life situations, these distance and stability values are not sufficient. In this study, we constructed a dedicated CTS facility and conducted a long-haul (180 m) CTS demonstration. As a result, it was verified that this long-range CTS is capable of maintaining stable sub-microsecond time synchronization for 3 days with a granularity of 148.8 ns (SD) and an offset of 22.97 ns. Since the current version of CTS can now operate over an area that has been enlarged by more than one order of magnitude, it is possible to utilize for more diverse applications, and the application to a banking synchronization system is proposed. As a case study, it is shown that CTS now has the capability to offer wireless time synchronization service to large clusters of financial firms in large cities. With its accurate time dissemination (the metrological traceability to UTC), its reasonable cost, and its hack-proof, stable design, this latest CTS model has the capacity to improve the accuracy of timing for a wide variety of sectors.
Abstract
Since the development of many future technologies are becoming more and more dependent on indoor navigation, various alternative navigation techniques have been proposed with radio waves, ...acoustic, and laser beam signals. In 2020, muometric positioning system (muPS) was proposed as a new indoor navigation technique; in 2022, the first prototype of wireless muPS was demonstrated in underground environments. However, in this first physical demonstration, its navigation accuracy was limited to 2–14 m which is far from the level required for the practical indoor navigation applications. This positioning error was an intrinsic problem associated with the clock that was used for determining the time of flight (ToF) of the muons, and it was practically impossible to attain cm-level accuracy with this initial approach. This paper introduces the completely new positioning concept for muPS, Vector muPS, which works by determining direction vectors of incoming muons instead of utilizing ToF. It is relatively easier to attain a 10-mrad level angular resolution with muon trackers that have been used for muographic imagery. Therefore, Vector muPS retains the unique capacity to operate wirelessly in indoor environments and also has the capacity to achieve a cm-level accuracy. By utilizing an essentially different concept from what is used in other navigation techniques, (measuring the distance between the reference and the receiver), Vector muPS enables more flexible, and longer-term stable positioning. Anticipated applications and the future outlook of Vector muPS is also discussed.
Time synchronization of sensor nodes is critical for optimal operation of wireless sensor networks (WSNs). Since clocks incorporated into each node tend to drift, recurrent corrections are required. ...Most of these correction schemes involve clients periodically receive RF timing signals from a time server. However, an RF-based scheme is prone to glitches or failure unless operating in a region with almost entirely unobstructed space; hence it only operates well in a limited range of environments. For example, GPS requires open-sky environments. Moreover, the precision of land-based RF schemes is limited to a few micro seconds. In this work, we report on a more versatile and new type of recurrent clock resynchronization scheme called cosmic time calibrator (CTC) and its development and testing. CTC utilizes cosmic-ray muon signals instead of RF signals. Muons are penetrative and continuously precipitating onto the Earth's surface, and they tend to travel linearly through encountered matter at approximately the speed of light in vacuum. Therefore, muons themselves can periodically transfer the precise timing information from node to node; hence, the performance of the inter-nodal communication device such as Wi-Fi or Bluetooth is minimized/unnecessary for an online/offline WSN analysis. The experimental results have indicated that a resynchronization frequency and precision of 60 Hz and ± 4.3 ns (S.D.) can be achieved. Modelling work of the WSN-based structural health monitoring of aerospace structures has shown that CTC can contribute to the development of new critical and useful applications of WSN in a wider range of environments.
•First long-term OS data of erlotinib + bevacizumab vs erlotinib in this population.•Both treatment arms showed a similar median OS of approximately 4 years.•Results of EGFR and VEGF inhibitor ...combination therapies are eagerly awaited.
The JO25567 randomized Phase II study demonstrated a statistically significant progression-free survival (PFS) benefit with erlotinib plus bevacizumab compared with erlotinib monotherapy in chemotherapy-naïve Japanese patients with epidermal growth factor receptor mutation-positive (EGFR+) non-small-cell lung cancer (NSCLC). Here we present updated PFS and final overall survival (OS) data after a median follow-up of 34.7 months.
Patients with stage IIIB/IV or postoperative recurrent NSCLC were randomized to receive oral erlotinib 150 mg once daily (n = 77) or erlotinib in combination with intravenous bevacizumab 15 mg/kg every 21 days (n = 75) until disease progression or unacceptable toxicity. OS was analyzed using an unstratified Cox proportional hazards model.
Consistent with the primary analysis, addition of bevacizumab to erlotinib was associated with a significant improvement in PFS (hazard ratio HR 0.52; 95 % confidence interval CI: 0.35–0.76; log-rank two-sided P = 0.0005; median 16.4 months vs 9.8 months, respectively). In contrast, a significant improvement in OS was not seen (HR 0.81; 95 % CI, 0.53–1.23; P = 0.3267; median 47.0 months vs 47.4 months, respectively). Post-study therapy was similar between the treatment arms and EGFR mutation type did not affect OS outcomes. The 5-year OS rate was numerically higher with erlotinib plus bevacizumab vs erlotinib monotherapy (41 % vs 35 %). Updated safety analyses confirmed the previously reported manageable tolerability profile, with no new safety issues.
Addition of bevacizumab to first-line erlotinib did not show significant improvement in OS in Japanese patients with stage IIIB/IV or postoperative recurrent EGFR+ NSCLC. Both treatment arms showed a similar median OS benefit (as long as 4 years), irrespective of individual patient characteristics. Results from ongoing studies evaluating the combination of EGFR and VEGF signaling inhibitors are eagerly awaited.
JapicCTI-111390 and JapicCTI-142569.
Three-dimensional organoid constructs serve as increasingly widespread in vitro models for development and disease modeling. Current approaches to recreate morphogenetic processes in vitro rely on ...poorly controllable and ill-defined matrices, thereby largely overlooking the contribution of biochemical and biophysical extracellular matrix (ECM) factors in promoting multicellular growth and reorganization. Here, we show how defined synthetic matrices can be used to explore the role of the ECM in the development of complex 3D neuroepithelial cysts that recapitulate key steps in early neurogenesis. We demonstrate how key ECM parameters are involved in specifying cytoskeleton-mediated symmetry-breaking events that ultimately lead to neural tube-like patterning along the dorsal–ventral (DV) axis. Such synthetic materials serve as valuable tools for studying the discrete action of extrinsic factors in organogenesis, and allow for the discovery of relationships between cytoskeletal mechanobiology and morphogenesis.
Abstract
Measurements of volcanic tephra fallout deposits provide useful information about the magnitude and intensity of explosive volcanic eruptions and potential for remobilization of deposits as ...dangerous volcanic flows. However, gathering information in the vicinity of erupting craters is extremely dangerous, and moreover, it is often quite difficult to determine deposit thickness proximal to volcanic craters because the thickness of the deposit is too great to easily measure; thus, airborne remote sensing technologies have generally been utilized during the intermission between eruptions. As an alternative tool, a muographic tephra deposit monitoring system was developed in this work. Here we report the performance of this system by applying the muographic data acquired at Sakurajima volcano, Japan as an example. By assuming the average density of the deposit was 2.0 g cm
−3
, the deposit thicknesses measured with muography were in agreement with the airborne results, indicating that volcanic fallout built up within the upper river basin, showed its potential for monitoring the episodic tephra fallouts even during eruptions.
Sub-hourly to seasonal and interannual oceanographic phenomena can be better understood with high special resolution and high frequency tidal observations. However, while current tidal measurements ...can provide sufficiently high observational density in terms of time, the observational density in terms of space is low mainly due to the high expense of constructing tide gauge stations. In this work, we designed a novel tide monitoring technique with muography that could be operated in near-shore basements (or similar structures on land below sea level) and found that more practical, stable, robust and cost-effective high-spatiotemporal-density tide measurements are possible. Although the time resolution, sensitivity, and the distance between the detectors and the shorelines are tradeoffs, hourly and annual sensitivity (ability to detect the tide height variations) of less than 10 cm and 1 mm can be statistically attained, respectively. It is anticipated that the current muographic technique could be applied as an alternative, cost-effective and convenient dense tidal monitor network strategy in coastal areas worldwide.
Pulsating auroras (PsAs) are thought to be generated by precipitating electrons scattered by lower‐band chorus (LBC) waves near the magnetic equator. One‐to‐one correlation between the LBC intensity ...and the PsA intensity has been reported. Electrostatic electron cyclotron harmonic (ECH) waves can also scatter electrons. However, direct correlation between ECH and PsA has not been reported yet. In this study, using a coordinated Exploration of energization and Radiation in Geospace (Arase) satellite and ground‐based imager observation, we report that not only LBC but also ECH have correlation with PsA. We estimated the precipitating electron energy by assuming that the time lag when the cross‐correlation coefficient became the highest was travel time of electrons from the modulation region. We found that the estimated energies show reasonable values as the cyclotron resonance energy of each wave.
Plain Language Summary
Pulsating auroras (PsAs), which have quasiperiodic on‐off switching emission, are caused by the intermittent electron precipitation from the magnetosphere. Such electrons are precipitated by wave‐particle interactions. The candidate waves to interact with electrons are lower‐band chorus (LBC) and electrostatic electron cyclotron harmonic (ECH) waves. One‐to‐one correspondence between the LBC wave intensity and the PsA intensity has been reported by previous studies. However, the correlation between ECH and PsA has not been reported yet. In this study, using a coordinated Exploration of energization and Radiation in Geospace (Arase) satellite and ground‐based all‐sky imager observation, we report that not only LBC but also ECH waves have correlation with PsAs.
Key Points
The lower‐band chorus and electrostatic electron cyclotron harmonic wave intensities had correlation with the pulsating auroral intensity
Taking advantage of high sampling rate of the imager, we estimated the energy of precipitating electrons
The energy of precipitating electrons was reasonable compared with the cyclotron resonance energy of each wave
Salamanders serve as important tetrapod models for developmental, regeneration and evolutionary studies. An extensive molecular toolkit makes the Mexican axolotl (Ambystoma mexicanum) a key ...representative salamander for molecular investigations. Here we report the sequencing and assembly of the 32-gigabase-pair axolotl genome using an approach that combined long-read sequencing, optical mapping and development of a new genome assembler (MARVEL). We observed a size expansion of introns and intergenic regions, largely attributable to multiplication of long terminal repeat retroelements. We provide evidence that intron size in developmental genes is under constraint and that species-restricted genes may contribute to limb regeneration. The axolotl genome assembly does not contain the essential developmental gene Pax3. However, mutation of the axolotl Pax3 paralogue Pax7 resulted in an axolotl phenotype that was similar to those seen in Pax3
and Pax7
mutant mice. The axolotl genome provides a rich biological resource for developmental and evolutionary studies.
PDF
