Time Coverage Research Articles

An Efficient Imaging Method for Medium-Earth-Orbit Multichannel SAR-GMTI Systems

Medium-Earth-orbit (MEO) synthetic aperture radar (SAR) has the advantages of short revisit time and wide coverage, and thus is a potential tool for implementing ground moving target indication (GMTI) tasks. In the paper, aiming at MEO SAR’s problems of low signal-to-noise ratio and limited computation resource, an efficient imaging method is proposed for MEO multichannel SAR-GMTI systems with relatively low resolution. The proposed imaging method is designed with the consideration of both static scenes and ground moving targets, and it can simultaneously correct the range cell migrations of static scenes and multiple moving targets of no Doppler ambiguity. It needs only four Fourier transforms and twice phase multiplications, and thus is computationally efficient. Moreover, moving targets’ signal characteristics, including the azimuth and range displacements and along-track interferometric phase, in the SAR image obtained by the proposed imaging method are figured out. Experimental results validate the proposed imaging method and the theoretical analyses.

Characterization of the Thermospheric Mean Winds and Circulation During Solstice Using ICON/MIGHTI Observations

AbstractUsing the horizontal neutral wind observations from the Michelson Interferometer for Global High‐resolution Thermospheric Imaging (MIGHTI) instrument onboard NASA's Ionospheric Connection Explorer (ICON) spacecraft with continuous coverage, we determine the climatology of the mean zonal and meridional winds and the associated mean circulation at low‐to middle latitudes (10°S–40°N) for Northern Hemisphere summer solstice conditions between 90 and 200 km altitudes, specifically on 20 June 2020 solstice as well as for a one‐month period from 8 June–7 July 2020 and for Northern winter season from 16 December 2019–31 January 2020, which spans a 47‐day period, providing full local time coverage. The data are averaged within appropriate altitude, longitude, latitude, solar zenith angle, and local time bins to produce mean wind distributions. The geographical distributions and local time variations of the mean horizontal circulation are evaluated. The instantaneous horizontal winds exhibit a significant degree of spatiotemporal variability often exceeding ±150 m s−1. The daily averaged zonal mean winds demonstrate day‐to‐day variability. Eastward zonal winds and northward (winter‐to‐summer) meridional winds are prevalent in the lower thermosphere, which provides indirect observational evidence of the eastward momentum deposition by small‐scale gravity waves. The mean neutral winds and circulation exhibit smaller scale structures in the lower thermosphere (90–120 km), while they are more homogeneous in the upper thermosphere, indicating the increasingly dissipative nature of the thermosphere. The mean wind and circulation patterns inferred from ICON/MIGHTI measurements can be used to constrain and validate general circulation models, as well as input for numerical wave models.

Analysis of Comprehensive Multi-Factors on Station Selection for Moon-Based Earth Observation

With the rapid development of Moon exploration, the concept of establishing Moon-based station for Earth observation (MBSEO) has received more and more attention. Compared with the space-borne Earth observation method, the MBSEO can observe Earth with advantages of higher stability, longer period, wider range, better integrity, and consistency. The MBSEO can not only cover the entire Earth disc, but also has good observation of the target area (TA) whose radius is several times that of the Earth radius (e.g., plasma-sphere/magnetosphere). Basically, site selection is a prerequisite for MBSEO. In this paper, the time coverage of TA (TCTA), e.g., the whole Earth disc or Earth-related plasma-sphere and magnetosphere, and the time coverage of sunlight (TCS) without topography are briefly presented to show their distribution. However, the unevenly distributed craters on the near side make TCTA and TCS badly affected by complicated topography, thereby causing those sites with a high selection possibility of a single factor to not necessarily be suitable for other factors. For example, potential sites at the low-middle latitude on the near side might have better TCTA and flat topography, but its TCS might be terrible for MBSEO. In order to evaluate the above factors comprehensively, a multi-factor fuzzy evaluation (MFE) method based on a multiple-input single-output (MISO) model will be utilized in the period of 18.6 nutation years. By using the proposed evaluation method, the sites near the dividing line, e.g., Amundsen, can still have the absolute possibility of exceeding 0.6, which was selected as MBSEO in low acceptability of sunlight. A similar situation exists in other areas with weaker sunlight constraint, e.g., Malapert A, in the case that the absolute selection possibility of areas becomes closer if more sunlight is tolerable. The results indicate that the areas with low thermal environment for radiation protection and relatively flat topography will have more possibility to be selected, and those potential sites unevenly distributed in craters can still be picked out through our proposed method.

Interrelationship between borehole lithology and electrical resistivity for geotechnical site investigation

In the modern era of geophysics, Electrical Resistivity Tomography (ERT) is an important tool to be use for early prediction of subsurface mapping. ERT act to inject electric current to the ground to study the chargeability or the resistivity value of a material. Engineers, geologist and researchers can apply ERT for their subsurface investigation since ERT proves to be very efficient and effective for subsurface mapping in term of cost, time and data coverage. 2D Electrical Resistivity Tomography survey was performed in Kuala Krau, Temerloh, Pahang to assist geotechnical site investigation. There are two available boreholes (BH 1 and BH 2) lithological data which can be correlated directly with the resistivity profile. One of the boreholes report hard rock layer at 9 m depth overlain by silt and clay. This hard layer was represented by resistivity value higher than 600 Ω m and 10–70 Ω m low resistivity layer overlain the hard layer. The low resistivity layer is associated with saturated silt and clay. Another borehole shows the existence of weathered sandstone at depth 11 m–17 m also overlain by silt and clay. Resistivity profile show the weathered region from the said borehole contacted edge side of sandstone boulder which also represented by higher than 600 Ω m resistivity value. 3D voxel was also generated from inversed resistivity value. The 3D voxel has successfully shown the lateral distribution of the geotechnical target. In conclusion, from this study, it is proven that results from ERT can be verified with the results from borehole lithology since the results obtained were almost accurate.

Search-based reduction model for unit testing

Software tests are fundamental in the reliability and quality of systems, contributing to their positioning in the market. Generating test data is a critical task, as exhaustive testing is costly in time and effort. An adequate design of the test cases, which contemplates a selection of adequate values, can detect a high number of defects. The effectiveness of the test cases is measured according to the number of errors they managed to detect. However, the proposals that address these issues with the use of heuristic algorithms focus on the reduction of generation time and different coverage criteria. This article presents a search-based optimization model for the generation of unit test suites that integrates different test case design techniques considering the significance of the values generated in the detection of errors. The significance of the paths is also taken into account, with the aim of obtaining test cases with greater potential to detect errors. The optimization model uses heuristic algorithms that maximize the coverage of the paths. The results of the experimentation are presented, which show that the proposal presented generates test suits with a high capacity to detect errors. For this, the effectiveness of the generated test suits to detect errors in the mutated code was evaluated.

Enhancing the usability of weather radar data for the statistical analysis of extreme precipitation events

Abstract. Spatially explicit quantification on design storms is essential for flood risk assessment and planning. Due to the limited temporal data availability from weather radar data, design storms are usually estimated on the basis of rainfall records of a few precipitation stations only that have a substantially long time coverage. To achieve a regional picture, these station-based estimates are spatially interpolated, incorporating a large source of uncertainty due to the typical low station density, in particular for short event durations. In this study we present a method to estimate spatially explicit design storms with a return period of up to 100 years on the basis of statistically extended weather radar precipitation estimates, based on the ideas of regional frequency analyses and subsequent bias correction. Associated uncertainties are quantified using an ensemble-sampling approach and event-based bootstrapping. With the resulting dataset, we compile spatially explicit design storms for various return periods and event durations for the federal state of Baden Württemberg, Germany. We compare our findings with two reference datasets based on interpolated station estimates. We find that the transition in the spatial patterns of the design storms from a rather random (short-duration events, 15 min) to a more structured, orographically influenced pattern (long-duration events, 24 h) seems to be much more realistic in the weather-radar-based product. However, the absolute magnitude of the design storms, although bias-corrected, is still generally lower in the weather radar product, which should be addressed in future studies in more detail.

EEG microstates in resting condition in young indians

Objectives: The map topography analysis gives an idea of temporal dynamics of electric fields, which is reference independent, making the results unambiguous. These topographic maps remain stable for 80 to 100 milliseconds, abruptly shifting to a new topographic map configuration and remains stable in that state are called the ‘functional microstates’ as described by Lehmann et al (1987). There has been no study done in the resting state eye closed and eye open conditions showing the microstate maps in healthy Indian subjects in resting eyes open and resting eyes closed condition using 128 channel EEG. So our study aim was to assess the microstates in resting eyes closed and eyes open condition. And to compare the microstate parameters such as mean duration, global explained variance (GEV) and time coverage between eyes closed and eyes open condition. Materials and Methods: A cross-sectional and observational study on 20 indian subjects (Mean age- 26.65 and (SD) - 2.78 years) was done on resting eyes closed and eyes open conditions. After EEG acquisition using 128 channel EEG machine, EEG was preprocessed and microstate analysis using CARTOOL software was performed on the EEG data. Results: After microstate analysis four maps topography were obtained. There was statistically non-significant difference observed in microstate maps between resting eyes closed and resting eyes open condition for the all parameters i.e. mean duration, time coverage and GEV. Conclusion: Our findings suggests that, both eyes closed and eyes open conditions were similar to each other in terms of stability and predominance of Maps.

Analysis of Spray Droplet and Deposition of Selected Nozzles Using Image Processing Techniques

Chemicals are used to improve the quality and productivity of crops. Contrarily, it can cause severe ecological and civic well-being difficulties owing to spray drift. The drift can be reduced by choosing a nozzle that yields the largest droplet dimension, and providing acceptable coverage at the anticipated claim rate and pressure. Droplet dimension distribution depended on nozzle type, which confirmed the potential of these factors for reducing spray drift. As a consequence of spray drift, residents, livestock, terrestrial and aquatic ecosystem may get exposed to toxic elements. On the other hand, aerial spraying has its advantages like greater efficiency, mobility, and more extensive area coverage in less time. An experimental setup was framed to select a nozzle suitable for UAV spraying in coconut palms, and a series of experiments were conducted to identify better deposition and droplet density of spray liquids at different operating pressures. The setup consists of a spray lance with a universal connector to attach the selected nozzle and a stand to hold the nozzle orientation, height, angle, and direction of the spray. The experiments were conducted with combinations of different levels of variables. For all the combinations of variables, samples were drawn to quantify the effect of selected variables on the droplet size generated. The selected nozzle's discharge rate gradually increases with increasing pressure. ImageJ is a Java-based image handling publicly accessible software developed by the US Institutes of Health (NIH) and the DepositScan provides a wide range of attributes of droplets, such as the number of droplets, equivalent diameter, droplet area, etc., measured by using the program. The pre-determined area for determination of the size of droplets was selected, copied, and pasted into a new file, then the image was binarized. The best treatment result was observed in hollow cone nozzle and NTM nozzle, which is suitable for UAV coconut sprayer based on the deposition and droplet density.

Evaluation of Chemcatcher® passive samplers for pesticide monitoring using high-frequency catchment scale data

Passive samplers (PS) have been proposed as an enhanced water quality monitoring solution in rivers, but their performance against high-frequency data over the longer term has not been widely explored. This study compared the performance of Chemcatcher® passive sampling (PS) devices with high-frequency sampling (HFS: 7-hourly to daily) in two dynamic rivers over 16 months. The evaluation was based on the acid herbicides MCPA (2-methyl-4-chlorophenoxyacetic acid), mecoprop-P, fluroxypyr and triclopyr. The impact of river discharge parameters on Chemcatcher® device performance was also explored. Mixed effects modelling showed that time-weighted mean concentration (TWMC) and flow-weighted mean concentration (FWMC) values obtained by the HFS approach were both significantly higher (p < 0.001) than TWMC values determined from PS regardless of river or pesticide. Modelling also showed that TWMCPS values were more similar to TWMCHFS than FWMCHFS values. However, further testing revealed that MCPA TWMC values from HFS and PS were not significantly different (p > 0.05). There was little indication that river flow parameters altered PS performance—some minor effects were not significant or consistent. Despite this, the PS recovery of very low concentrations indicated that Chemcatcher® devices may be used to evaluate the presence/absence and magnitude of acid herbicides in hydrologically dynamic rivers in synoptic type surveys where space and time coverage is required. However, a period of calibration of the devices in each river would be necessary if they were intended to provide a quantitative review of pesticide concentration as compared with HFS approaches.

Description and comparison of 21st century thermosphere data

The quality and distribution in time and space of available atmospheric observations are crucial for the accuracy of semi-empirical thermosphere models. However, datasets can be inconsistent, and their qualities and resolutions are often unequal. The main thermospheric density datasets of this century are briefly described and then compared to each other when possible in order to quantify differences. Total mass densities used in the comparisons include all high-resolution CHAMP, GRACE and GOCE data, Swarm A, daily-mean Stella, global daily mean TLE densities, and the SET HASDM density database. The temperature data from TIMED-SABER are also reviewed.The recently updated daily-mean TLE densities (TLE2021) are 2–10 % smaller on average than the previous version (TLE2015). The differences are not constant offsets per altitude level, but fluctuations of up to 5 % are present. Compared to HASDM densities for 6 altitudes from 250 to 675 km, TLE2021 is 15–20 % smaller at 250 km, and then the difference diminishes with altitude to reach the same average value at 575 km. These mean differences also fluctuate by a few percent on time scales of months, to 10 % over half a solar cycle at 575 km. The TLE2021 and HASDM densities are larger than the accelerometer-inferred CHAMP, GRACE and GOCE densities and average offsets are 10–15 % and 10–20 %, respectively. The comparison to Swarm-A and Swarm-B showed mean offsets of 10 % and less, with significant positive trends seen in the comparison with HASDM. Finally, largest differences are found for Stella and HASDM at 800 km, up to 45 % with strong semiannual variations.This study clearly shows that the available density data cannot be simply assimilated or combined without first accurately calibrating the data. The HASDM database is a valuable asset due to its considerable coverage in space and time, but its uncertainty and true resolution are not well understood and are still being evaluated. Data compatibility requires employing physically accurate and harmonized aerodynamic force models in the density derivation procedure, which is presently not achieved. The accuracy of the procedure, independent of the quality of the instrument (GNSS receiver, ground-based orbit determination, or accelerometer), inevitably decreases with altitude due to weakening of the drag signal to noise ratio.The TIMED-SABER instrument provides measurements of pressure and temperature in the lower thermosphere. SABER temperature uncertainty is well-known. The SABER dataset now exceeds twenty years and has been continuously operating that entire time. It was ingested in NRLMSIS 2.0 and comparisons show the much-improved fit in comparison with NRLMSISE-00. The lower thermosphere temperatures significantly modify density at higher altitudes, and its measurement is essential for modeling and assessment.

Migrating Thermal Tides in the Martian Atmosphere During Aphelion Season Observed by EMM/EMIRS

AbstractTemperature profiles retrieved using the first set of data of the Emirates Mars InfraRed Spectrometer obtained during the science phase of the Emirates Mars Mission are used for the analysis of migrating thermal tides in the Martian atmosphere. The selected data cover a solar longitude (LS) range of 60°–90° of Martian Year 36. The novel orbit design of the Hope Probe leads to a good geographic and local time coverage that significantly improves the analysis. Wave mode decomposition suggests dominant diurnal tide and important semi‐diurnal tide with maximal amplitudes of 6 and 2 K, respectively, as well as the existence of ∼0.5 K ter‐diurnal tide. The results agree well with predictions by the Mars Planetary Climate Model, but the observed diurnal tide has an earlier phase (3 hr), and the semi‐diurnal tide has an unexpectedly large wavelength (∼200 km).

Sentinel-2 high-resolution data for river discharge monitoring

River monitoring is an open issue due to many intrinsic problems of the ground monitoring network. Over the last few decades, the role of satellite sensors in river discharge estimation is significantly increased thanks to the strong growth in technologies and applications. Focusing on daily river discharge measurements, a non-linear regression model has been used to link the near-infrared (NIR) reflectance ratio between a dry and a wet pixel around the section of a river to the ground measurements of river discharge. The use of medium-resolution satellite data, such as those from MODIS sensors, enables to monitor high and low flows in medium-sized catchments (<100,000 km2), thanks to satellite frequent revisit time and wide spatial coverage. However, such sensors are not suitable to provide information for medium-narrow rivers (< 250 m wide), nor to study river features and patterns that are averaged within a single pixel. Here, we investigated the use of Sentinel-2 NIR reflectances to support the hypothesis that a higher spatial resolution, i.e. 10 m, is able to better identify the wet pixels, more related to the river dynamics, with obvious advantages for river discharge estimation compared to the medium resolution sensors (e.g., MODIS at 250 m). Moreover, it also allows both a finer distinction between vegetation, soil and water and the characterization of water turbidity in the river area. A new formulation enriched by the sediment component is proposed together with a first step toward an uncalibrated procedure to select the wet pixels. Google Earth Engine (GEE) platform has been employed for the data analysis, allowing to avoid the download of big amounts of data, fostering the reproducibility of the analysis in different locations. The accuracy of the river discharges derived from Sentinel-2 reflectances is evaluated against the in-situ observations from selected gauging stations along two Italian rivers, Po and Tiber. The results confirm the good performances obtained with high-resolution images over the Po River, with average Nash-Sutcliffe efficiency ranging between 0.39 and 0.56 for the different configurations adopted. Relatively worse results were obtained over the Tiber River where the Nash-Sutcliffe efficiency ranged between 0.2 and 0.61, due to an issue on the registration of Sentinel-2 images.

Reconstruction of the record of tritium in precipitation in the temperate zone of South America

AbstractTritium, a radioisotope of hydrogen, is an ideal tracer for groundwater and surface dating and tracking since it is part of the water molecule. The knowledge of the history of tritium in precipitation and recharge is the key link for the calculation of groundwater tritium age. However, records of tritium in precipitation are usually sparse and discontinuous, especially in regions like South America, and often need to be reconstructed. To solve this problem, different reconstruction methods of the tritium input function have been analysed and compared. Clustering of Global Network of Isotopes in Precipitation stations by regions and the correlation with the complete and continuous data recorded in Kaitoke (New Zealand) proved to be the most effective approach, having low relative errors and a much more extended coverage in time compared to other interpolation or reference curves methods. Thus, tritium time series for five different regions of the temperate zone of South America were obtained. These curves can be used as representative tritium input curves in future studies for these regions. The results obtained also allow a quick qualitative analysis of groundwater ages in these areas, based on their current or past tritium concentrations. In addition, they contributed to the understanding of the patterns and characteristics of tritium distribution in the atmosphere of the southern sector of South America.

GreenForensics: Deep hybrid edge-cloud detection and forensics system for battery-performance-balance conscious devices

Motivated by the advancements made by the recently proposed DRo algorithm to uplift the performance of data scarce Deep Learning malware detector for edge, we propose an adaptive and efficient system for hybrid edge-cloud detection and forensics, named GreenForensics. The proposed adaptive enhancement, makes the system more suitable for devices with custom battery-performance optimization mandates like tablets and laptops. Further, the enhancements offer various discrete and continuous controls for influencing the detection coverage and model footprints in real time. To further enhance the detection efficiency and making the detection resilient to adversarial-attacks, the proposed system can work with adversarial-DL immune algorithms. In the experiments conducted, GreenForensics was able to significantly outperform even the best baseline deep architectures and improved the detection and forensics robustness by up to 100% and performance by up to 40%. This gains further significance as the incumbent baseline DL architecture had up to 6700% higher neural inference complexity, and had its performance and robustness benchmarks had remained unchallenged for a long time.

Artificial Intelligence for the Analysis of Workload-Related Changes in Radiologists’ Gaze Patterns

Around 60-80% of radiological errors are attributed to overlooked abnormalities, the rate of which increases at the end of work shifts. In this study, we run an experiment to investigate if artificial intelligence (AI) can assist in detecting radiologists' gaze patterns that correlate with fatigue. A retrospective database of lung X-ray images with the reference diagnoses was used. The X-ray images were acquired from 400 subjects with a mean age of 49 ± 17, and 61% men. Four practicing radiologists read these images while their eye movements were recorded. The radiologists passed a series of concentration tests at prearranged breaks of the experiment. A U-Net neural network was adapted to annotate lung anatomy on X-rays and calculate coverage and information gain features from the radiologists' eye movements over lung fields. The lung coverage, information gain, and eye tracker-based features were compared with the cumulative work done (CDW) label for each radiologist. The gaze-traveled distance, X-ray coverage, and lung coverage statistically significantly (p < 0.01) deteriorated with cumulative work done (CWD) for three out of four radiologists. The reading time and information gain over lungs statistically significantly deteriorated for all four radiologists. We discovered a novel AI-based metric blending reading time, speed, and organ coverage, which can be used to predict changes in the fatigue-related image reading patterns.

Evaluation optimization method for site selection of urban emergency medical material distribution center

In order to solve the problems of long distribution time and small distribution coverage of urban emergency medical materials distribution centers, this paper constructs an nondominated sorting genetic algorithm-Ⅱ-based (NSGA-Ⅱ-based) optimal location model for the urban emergency medical material distribution center. Aiming at minimizing the cost of transportation and maximizing the coverage of the population and medical resources of the emergency material collection and distribution center to the adjacent areas, the model introduces a compromise fuzzy decision-making method for the overall location plan and establishes an improved analytic hierarchy process (AHP)-fuzzy compromise decision evaluation model. The compromise fuzzy decision-making method is constructed to optimize the overall site selection decision-making. The feasibility of the model is verified by taking the location selection scheme of emergency medical materials collection and distribution in Gaocheng District of Shijiazhuang City, Hebei Province as an example. The results show that the construction of seven centralized distribution centers can meet the needs of epidemic prevention and control in Gaocheng District, Shijiazhuang City. The construction and transportation costs are reduced. The average transportation time of the optimal scheme is 18.9 minutes and the proportion of travel time over 30 minutes driving is 13.3%, which are reduced by 49.1% and 80.0% respectively compared with the previous scheme. The research results can provide reference for the location plan of emergency collection and distribution center under urban public health emergencies.

Linkage of Routinely-Collected Maternity Data with a Cerebral Palsy Register: Matching Success and Temporal Assessment of Data Quality and Maternal Characteristics.

ObjectivesThis study aimed to 1) establish the success rate of matching offspring in the Northern Ireland Cerebral Palsy Register (NICPR) to mother-infant pairs within the Northern Ireland Maternity System (NIMATS); and explore changes in 2) quality of maternal data (NIMATS) and 3) maternal characteristics over the study period. ApproachData for individuals with cerebral palsy (CP) born between 1990 (commencement of NIMATS) and 2012 (latest fully validated birth year in NICPR) were transferred to the Honest Broker Service, who performed data linkage. Offspring were primarily matched between NICPR and NIMATS using the unique Health and Care Number (HCN). Where this was unavailable in NIMATS, matching from offspring to mothers/pregnancies was performed using surname, gender, date of birth +/- postcode. Changes in completeness and quality of data and maternal characteristics were explored per year and visualised using histograms. All pre-processing and analyses were performed using R. ResultsFrom 1263 included CP cases, 377(30%) were matched using HCN. A further 121(9%) were matched by secondary strategies. Substantial improvements in completeness of maternal data were observed over time (body mass index (46.2% to 97.7%); BP (44.8% to 95.3%); age 100% complete throughout). An apparent tendency to round systolic and diastolic blood pressure to the nearest ten was observed. This tendency decreased over time which potentially led to an overestimation of hypertension detected in earlier years. Characteristics of mothers also changed over the study duration, seen in increasing proportions with BMI≥30 kg/m2 (9.97% to 18.9%). Age of mothers also increased with decreasing proportions aged&lt;25y (33.7% to 19.6%) and increasing proportions aged≥35y (9.7% to 20.4%). No change over time was observed in maternal blood pressure variables. ConclusionMatching success was affected by incomplete NIMATS coverage in earlier years and lag time in CP diagnosis being confirmed by NICPR (typically beyond the age of 4 years). Over time, completeness and quality of maternal variables in NIMATS has improved meaning future studies using these linkages will be more reliable.

The UAV Path Coverage Algorithm Based on the Greedy Strategy and Ant Colony Optimization

Today, the development of unmanned aerial vehicles (UAVs) has attracted significant attention in both civil and military fields due to their flight flexibility in complex and dangerous environments. However, due to energy constraints, UAVs can only finish a few tasks in a limited time. The problem of finding the best flight path while balancing the task completion time and the coverage rate needs to be resolved urgently. Therefore, this paper proposes a UAV path coverage algorithm base on the greedy strategy and ant colony optimization. Firstly, this paper introduces a secondary advantage judgment and optimizes it using an ant colony optimization algorithm to reach the goal of minimum time and maximum coverage. Simulations are performed for different numbers of mission points and UAVs, respectively. The results illustrate that the proposed algorithm achieves a 2.8% reduction in task completion time while achieving a 4.4% improvement in coverage rate compared to several previous works.

Luminescence chronology for identifying depositional sequences in an uplifted coast since the Middle Pleistocene, eastern Japan

Feldspar post-infrared infrared stimulated luminescence (pIRIR) dating is an advantageous trapped-charge dating method concerning late Quaternary sedimentary records for its direct applicability to clastic sediments and wide time coverage. Its application to depositional sequences in various coastal settings potentially improve our understanding of long-term sea-level changes and regional tectonics that the sequences record. The Kanto coastal plain, eastern Japan is situated in a unique tectonic setting near the triple junction of plate boundaries and characterized by extensive development of the Last Interglacial raised marine terrace in contrast to the longer-term subsidence trend. In this article, we document the application of feldspar pIRIR dating to a 35-m-long sediment core collected from the marine terrace in the northeastern Kanto plain and examine how effective its chronology is for identifying depositional sequences related to the relative sea-level fluctuations since the Middle Pleistocene. The sediment core shows a succession of seven facies units, A to G, in ascending order, representing the shallow marine to shelf (units A to C), fluvial to brackish salt marsh (unit D), beach to shoreface (unit E), fluvial to aeolian (unit F), and loess (unit G) sedimentation. According to pre-tests, pIRIR at 225°C after prior infrared stimulated luminescence at 50°C (pIRIR225) was chosen as an optimal signal for dating. pIRIR225 is characterized by modest anomalous fading with an average g2days-value of 1.8%/decade. Fading-corrected pIRIR225 ages are consistent with the stratigraphy. Units A and B are dated as Marine Oxygen Isotope Stage (MIS) 7 and units C to F as MIS 5. However, uncertainties of individual age estimates do not allow further chronological correlation. Instead, using sea-level changes inferred from characteristic facies transitions as additional constraints, units C to F can be correlated to sub-stages in MIS 5. Unit E represents coastal progradation during the MIS 5c sea-level highstand, which refines the date of the marine terrace around the core site as MIS 5c and revises up the rate of the tectonic uplift accordingly. Our results exemplify a successful application of feldspar pIRIR dating for identifying depositional sequences formed in relations to 100-kyr glacial cycles, in which, with additional information of the sedimentary facies, higher-frequency sequences may be defined.

Immunogenicity and reactogenicity of heterologous immunization against SARS CoV-2 using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV, and mRNA-1273

SummaryHeterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.