The sporadic‐E (Es) layer is an ionospheric layer which appears occasionally near 100‐km heights with extremely high electron density. The Es layer may reflect very high‐frequency radio signals when ...the incident angle is shallow (Es layer anomalous propagation EsAP). It is known that radio signals with frequencies above 100 MHz sometimes reach distant locations, more than 600 km apart from the transmitters, due to EsAP. Since air‐navigation radio channels are allocated on frequencies between 108 and 118 MHz, EsAP may interfere with directly propagating wave (ground wave) signals. However, as the occurrence and strength of EsAP on these frequencies have not been studied well, it is difficult to assess the impact of EsAP on the air navigation. In this paper, we report the statistics of the occurrence and strength of EsAP based on a 3‐year continuous monitoring of very high‐frequency air‐navigation radio signal strength on the ground. The statistics show that strong EsAPs occur frequently in summer. The occurrence pattern of EsAP is generally consistent with ionosonde observations of Es layer: Most Es layers appear during summer, primary peak in daytime, with a second peak in the evening. During an extreme EsAP event, in a particular channel, an EsAP signal was superposed on a ground wave signal which resulted in a fluctuation of ground wave signal by more than ±10 dB. Our statistical results suggest that the Es layer has a potential impact on air‐navigation applications.
Key Points
A system to continuously monitor VHF air navigation radio (VHF‐NAV) signals was developed to study the sporadic‐E (Es) radio propagation
Statistics of anomalous propagation of VHF air navigation radio signals due to Es were studied with 3‐year data
Strength of anomalous propagation signals was shown to be strong enough to potentially cause interference to avionics receivers
Epigenetic gene regulation linked to oncogenic pathways is an important focus of cancer research. KDM3A, a histone H3 lysine 9 (H3K9) demethylase, is known to have a pro-tumorigenic function. Here, ...we showed that KDM3A contributes to liver tumor formation through the phosphatidylinositol 3-kinase (PI3K) pathway, which is often activated in hepatocellular carcinoma. Loss of Kdm3a attenuated tumor formation in Pik3ca transgenic (Tg) mouse livers. Transcriptome analysis of pre-cancerous liver tissues revealed that the expression of activator protein 1 (AP-1) target genes was induced by PI3K activation, but blunted upon Kdm3a ablation. Particularly, the expression of Cd44, a liver cancer stem marker, was regulated by AP-1 in a Kdm3a-dependent manner. We identified Cd44-positive hepatocytes with epithelial-mesenchymal transition-related expression profiles in the Pik3ca Tg liver and confirmed their in vivo tumorigenic capacity. Notably, the number and tumor-initiating capacity of Cd44-positive hepatocytes were governed by Kdm3a. As a mechanism in Kdm3a-dependent AP-1 transcription, Kdm3a recruited c-Jun to the AP-1 binding sites of Cd44, Mmp7 and Pdgfrb without affecting c-Jun expression. Moreover, Brg1, a component of the SWI/SNF chromatin remodeling complex, interacted with c-Jun in a Kdm3a-dependent manner and was bound to the AP-1 binding site of these genes. Finally, KDM3A and c-JUN were co-expressed in 33% of human premalignant lesions with PI3K activation. Our data suggest a critical role for KDM3A in the PI3K/AP-1 oncogenic axis and propose a novel strategy for inhibition of KDM3A against liver tumor development under PI3K pathway activation.
Anomalous long‐distance propagation of Very High Frequency radio waves of aeronautical navigation systems was investigated by an airborne Instrument Landing System (ILS) localizer (ILS LOC) receiver ...installed on the ground at Kure, Japan (34.245°N, 132.528°E). Intense ILS LOC type signals were observed and the received power was strong enough for the aviation receiver to output course deviation. The radio source was identified by receiving the Morse Code for identification as the localizer‐type directional aid (LDA) serving the Runway‐21 of the Hualien Airport, Taiwan (24.0396°N, 121.6221°E) of which beam pointed close to the receiver. This result supports that the source of the signals often observed at the same frequency at the same location is most probably the LDA at the Hualien Airport. The maximum received power was −99 dBm for an omni‐directional antenna. It was strong enough to cause co‐channel interference. Considering stronger power (−70 dBm) found in previous observations at the same frequency at the same location, anomalous propagation of ILS LOC signals by the Es layer could be a cause of interference when a receiver was near the center of the ILS LOC beam. The course deviation output was consistent with the geometry between the beam of Runway‐21 LDA at the Hualien Airport and the receiver. However, the observed course deviation fluctuated remarkably even when the received power was strong enough. The fluctuation of the course deviation may indicate the structure of the Es layer, and observation of the course deviation could be used to diagnose the Es layer structure.
Plain Language Summary
Intense signals of an instrument landing system localizer (ILS LOC) for aircraft navigation was detected over anomalously long distance (about 1,550 km). The ILS LOC equivalent signal from Hualien Airport, Taiwan was observed by an ILS LOC receiver for aviation on the ground at Kure, Japan. The signal was strong enough to provide deviation of the position from the center of the beam and was strong enough to cause co‐channel interference. Considering stronger power found in previous observations at the same frequency at the same location, anomalous propagation of ILS LOC signals by the sporadic E (Es) layer, which is an ionospheric layer with a high electron density and thin altitudinal thickness, could be a cause of interference when a receiver was near the center of the ILS LOC beam. The fluctuation of the course deviation may indicate the structure of the Es layer, and could be used to diagnose the Es layer structure.
Key Points
Anomalous long‐distance propagation of Very High Frequency radio air navigation signals by the sporadic E layer was detected by an aviation receiver
The received signal was strong enough to cause interference to an aviation receiver at distances far outside the intended service area
Variation of course deviation information obtained from the ILS‐LOC signal could be used to study fine structures of the Es layer
The ionospheric sporadic‐E (Es) layer occasionally causes anomalous propagation (AP) of VHF radio waves to distant locations. This effect, EsAP, may cause interference to VHF radio operation above ...100 MHz. Recent study showed that VHF air navigation signals from distant stations are frequently observed when Es occurs. The observed frequencies includes channels of VHF omnidirectional radio range (VOR) and instrument landing system localizer (ILS LOC). The study showed that EsAP signals can be very strong and frequently exceeded the allowable interference limit of navigation receivers. In this paper, we focus on EsAP on ILS LOC channels using the data obtained in the previous study. A series of extremely strong signals was observed on an ILS LOC frequency at Kure, Japan, on 15 May 2014 when an ionosphere sounder observed high‐density Es. The source of the signal was identified as an ILS LOC‐type direction aid (LDA) at Hualien, Taiwan. During the same period, several EsAP signals were observed on other ILS LOC channels, but their strengths were less significant. Analysis showed the causes of the strong signal from Hualien LDA: (1) the center of the narrow radio beam passed through the region very close to the receiver site; (2) the elevation angle of the propagation path was very close to that of the actual beam center. Statistics showed that there were several outstanding EsAP events of which source was Hualien LDA. This study suggests that if similar conditions exist, radio interference to ILS LOC receiver can happen on any ILS LOC channels.
Key Points
Sporadic‐E (Es) propagation of Instrument Landing System (ILS) Localizer (LOC) radio was observed
Strong ILS LOC radio signal from distant (1500 km) airport was received occasionally due to Es
Strength of undesired signal often exceeded the interference limit of LOS receivers significantly
With the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), a high-speed and convenient detection technology should be at the ...forefront of medical care worldwide. This study evaluated the usefulness of GeneSoC, a compact, high-speed reciprocal flow quantitative reverse transcription polymerase chain reaction system, for the detection of SARS-CoV-2. The results support the use of this system for the rapid identification of SARS-CoV-2. This approach can contribute to the strategic selection of initial management strategies for patients with COVID-19.
A highly sensitive all‐sky electron multiplier charge‐coupled device airglow imager has been operative in Longyearbyen, Norway (78.1°N, 15.5°E), since October 2011. The imager obtains the 630.0 nm ...all‐sky images with an exposure time of 4 s, which is about 10 times shorter than the conventional cooled CCD airglow imagers. This new equipment allows us to image the ongoing structuring of polar cap patches in 2‐D fashion. Here we report a case in which faint undulations appeared along the trailing edge of patches propagating in the central polar cap. The separation between the fingers in the undulations was about 50–100 km and the e‐folding time of their growth was ∼5 min. We suggest that the gradient‐drift instability (GDI) is one of the possible generation mechanisms of the undulating structures. The reasons for this interpretation are (1) the asymmetry in the preference of structuring between the leading and trailing edges is qualitatively consistent with the GDI mechanism and (2) the linear growth rate of GDI calculated by using electron density estimates from simultaneous European Incoherent Scatter Svalbard radar observations is roughly consistent with the observed growth time of the fingers. Such “unstable polar cap patches” could be important sources of seed irregularities, which would eventually be broken down to smaller‐scale density perturbations affecting the transionospheric satellite communications in the central polar cap.
Key Points
Visualize on‐going structuring of polar cap patches in 2D fashion
Faint undulations of the trailing edge of the patches were identified
Structuring of patches can be explained by the gradient‐drift instability
Background
We previously reported that indocyanine green fluorescence imaging (ICG-FI)-guided laparoscopic lateral pelvic lymph node dissection (LPLND) was able to increase the total number of ...harvested lateral pelvic lymph nodes without impairing functional preservation. However, the long-term outcomes of ICG-FI-guided laparoscopic LPLND have not been evaluated. The aim of the present study was to compare the long-term outcomes of ICG-FI-guided laparoscopic LPLND to conventional laparoscopic LPLND without ICG-FI.
Methods
This was a retrospective, multi-institutional study with propensity score matching. The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic LPLND between January 2013 and February 2018. The main evaluation items in this study were the 3-year overall survival, relapse-free survival (RFS), local recurrence rate, and lateral local recurrence (LLR) rate.
Results
A total of 172 patients with middle-lower rectal cancer who had undergone laparoscopic LPLND were included in this study. After propensity score matching, 58 patients were matched in each of the ICG-FI and non-ICG-FI groups. There were no substantial differences in the baseline characteristics between the two groups. The ICG-FI group and non-ICG-FI group included 40 and 38 women and had a median age of 65 (IQR 60–72) and 66 (IQR 60–73) years, respectively. The median follow-up for all patients was 63.7 (IQR 51.3–76.8) months. The estimated respective 3-year overall survival, RFS, and local recurrence rates were 93.1%, 70.7%, and 5.2% in the ICG-FI group and 85.9%, 71.7%, and 12.8% in the non-ICG-FI group (
p
= 0.201, 0.653, 0.391). The 3-year cumulative LLR rate was 0% in the ICG-FI group and 9.3% in the non-ICG-FI group (
p
= 0.048).
Conclusions
This study revealed that laparoscopic LPLND combined with ICG-FI was able to decrease the LLR rate. It appears that ICG-FI could contribute to improving the quality of laparoscopic LPLND and strengthening local control of the lateral pelvis.
Trials Registration
This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 (
http://www.umin.ac.jp/ctr/index.htm
).
In this work we used Particle-In-Cell simulations to study the interaction of circularly polarised Alfven waves with one dimensional plasma density inhomogeneities transverse to the uniform magnetic ...field (phase mixing) in collisionless plasmas. In our preliminary work we reported discovery of a new electron acceleration mechanism, in which progressive distortion of the Alfven wave front, due to the differences in local Alfven speed, generates an oblique (nearly parallel to the magnetic field) electrostatic field. The latter accelerates electrons through the Landau resonance. Here we report a detailed study of this novel mechanism, including: (i) analysis of broadening of the ion distribution function due to the presence of Alfven waves; and (ii) the generation of compressive perturbations due to both weak non-linearity and plasma density inhomogeneity. The amplitude decay law in the inhomogeneous regions, in the kinetic regime, is demonstrated to be the same as in the MHD approximation described by Heyvaerts & Priest (1983, A&A, 117, 220).
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