Additional Satellite Research Articles

The Badlands Guardian: A Human Portrait with Feathered Headdress

This is an analysis of a large facial formation set within a glacial moraine along the southeast corner of Alberta, Canada, known as the Badlands Guardian. The formation is presented in one aerial and three satellite images acquired over the past 70 years by the Alberta Department of Lands & Forests and Google Earth. The images reveal a profiled portrait of a human head wearing a feathered headdress. The facial features include an eye, nose, mouth, chin, neck, and jawline. The headdress consists of a headband containing a staggered set of feather-shaped extensions. When taken together these aesthetic features create the visual impression of a left-facing portrait of an indigenous tribesman wearing a feathered headdress. A claim of intelligent design is offered and a geologist and geoscientist examine natural mechanisms that could contribute to the formation of these aesthetic features. A comparison of the iconographic tribal motifs of both North and South America is presented and a request for an extensive ground exploration and additional satellite images of this formation is encouraged.

Resonant enhancement of the near-field radiative heat transfer in nanoparticles

We numerically study the tuning of the radiative heat transfer between a spherical InSb nanoparticle in the vicinity of a flat SiC surface assisted by a static magnetic field. By changing the value of the applied magnetic field, the dielectric function of the nanosphere becomes anisotropic due to the excitation of magneto-plasmons. In the dipolar approximation, the plasmon resonance of the particle splits into two additional satellite resonances that shift to higher and lower frequencies as the field increases. When one of the particle resonances overlaps with the phonon-polariton frequency of the SiC surface, an enhancement of the heat transfer of two orders of magnitude is obtained. To understand the tuning of the radiative heat transfer, we present a detailed analysis of the nature of the modes that can be excited (surface, bulk, and hyperbolic).

A rare case of rapid evolution of choroidal osteoma

We present a case of a 19-year-old male with a history of right-sided orbital pseudotumor with suspected Burkitt's lymphoma. His best-corrected visual acuity (BCVA) was 6/36 in the right eye (RE) and 6/6 in the left eye (LE). On fundus examination, the patient had a large choroidal osteoma at the posterior pole with macular scarring, along with two additional satellite osteomas inferior and superonasal to the disc in OD, while OS was unremarkable. After conservative management with oral corticosteroids, the patient demonstrated an additional choroidal osteoma lesion nasal to the disc in the OD which had evolved over a period of merely 3 months. To the best of our knowledge, this is the first reported case to document such a rapid development of choroidal osteoma. This case highlights the need for frequent follow-up of these patients for early detection and monitoring of these lesions.

Satellite-Based Characterization of Convection and Impacts from the Catastrophic 10 August 2020 Midwest U.S. Derecho

Abstract The catastrophic derecho that occurred on 10 August 2020 across the midwestern United States caused billions of dollars of damage to both urban and rural infrastructure as well as agricultural crops, most notably across the state of Iowa. This paper documents the complex evolution of the derecho through the use of low-Earth-orbit passive-microwave imager and GOES-16 satellite-derived products complemented by products derived from NEXRAD weather radar observations. Additional satellite sensors including optical imagers and synthetic aperture radar (SAR) were used to observe impacts to the power grid and agriculture in Iowa. SAR improved the identification and quantification of damaged corn and soybeans, as compared to true-color composites and normalized difference vegetation index (NDVI). A statistical approach to identify damaged corn and soybean crops from SAR was created with estimates of 1.97 million acres of damaged corn and 1.40 million acres of damaged soybeans in the state of Iowa. The damage estimates generated by this study were comparable to estimates produced by others after the derecho, including two commercial agricultural companies.

Effect of data assimilation in the Polar WRF with 3DVAR on the prediction of radiation, heat flux, cloud, and near surface atmospheric variables over Svalbard

Although the Polar Weather Research and Forecasting (PWRF) model has been developed for polar environments, simulations of atmospheric states in the polar region still have large uncertainties. Therefore, the effects of data assimilation (DA) to improve forecasts in the polar region were investigated for September 2017 using PWRF and the three-dimensional variational (3DVAR) DA method. The experiments without DA and those with DA assimilating only conventional observations and both conventional observations and satellite radiance data were performed. The forecasts from all experiments both without and with DA underestimated (overestimated) the downward longwave (shortwave) radiation flux due to the underestimation of the amount of Arctic clouds. When satellite radiance data (i.e., the Advanced Microwave Sounding Unit-A (AMSU-A) and Microwave Humidity Sounder (MHS)) were assimilated in addition to conventional observations in the PWRF, the distribution and amount of water vapor became closer to observations, which improves cloud liquid water forecasts. Therefore, when both conventional observations and radiance data were assimilated, the 25–30 h forecast errors of the downward longwave and shortwave radiation fluxes and sensible and latent heat fluxes decreased by 12.7%, 8.1%, 3.2%, and 7.8% with the WSM5 scheme and by 17.1%, 4.7%, 2.5%, and 3.1% with the 2-moment Morrison scheme, respectively, compared to those in the experiments without DA. The forecast errors of the 10 m wind and 2 m temperature with DA were smaller than those without DA at most observation stations. Therefore, the uncertainties of the Arctic forecasts in the PWRF decreased when using DA. To further improve Arctic forecasts, the assimilation of various additional satellite data is necessary.

Global daily gap-free ocean color products from multi-satellite measurements

Gap-free global chlorophyll-a (Chl-a) concentration images derived from the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) and NOAA-20 are now available online in near-real-time for the ocean color community. With the data fusion of Chl-a from the two satellite sources, missing pixels caused by cloud, sun glint contamination, high satellite viewing angles, and other unfavorable conditions are completely filled using the Data Interpolating Empirical Orthogonal Function (DINEOF) method. Our further studies show that adding more data from additional satellite sensors can remarkably improve the spatial coverage of the merged ocean color products, provide more ocean features over coastal and inland waters, and enhance the accuracy of the gap-free data. Since the launch of the Sentinel-3A and Sentinel-3B satellites, the onboard Ocean and Land Colour Instrument (OLCI) sensors have been providing global ocean color product data. In this work, we recruit the OLCI-Sentinel-3A to join the two VIIRS sensors to produce a three-sensor merged ocean color dataset, and further derive global gap-free images using the DINEOF method. It is found that adding OLCI data as the input source significantly enhances the spatial features of high Chl-a by ∼10–20% in productive coastal regions and inland lakes. Additionally, the first-ever dataset of global gap-free suspended particulate matter (SPM) and water diffuse attenuation coefficient at 490 nm (Kd(490)) is also generated using the three-sensor merged data. Results show that Kd(490) and SPM have similar spatial patterns as that of Chl-a in the major ocean basins, and that SPM can provide more details of the spatial variations than those of Kd(490) in the center of the ocean basin and coastal oceans. Global gap-free Chl-a, Kd(490), and SPM products provide important and useful water quality information particularly over global productive ocean/water regions.

The Putative Drosophila TMEM184B Ortholog Tmep Ensures Proper Locomotion by Restraining Ectopic Firing at the Neuromuscular Junction.

TMEM184B is a putative seven-pass membrane protein that promotes axon degeneration after injury. TMEM184B mutation causes aberrant neuromuscular architecture and sensory and motor behavioral defects in mice. The mechanism through which TMEM184B causes neuromuscular defects is unknown. We employed Drosophila melanogaster to investigate the function of the closely related gene, Tmep (CG12004), at the neuromuscular junction. We show that Tmep is required for full adult viability and efficient larval locomotion. Tmep mutant larvae have a reduced body contraction rate compared to controls, with stronger deficits in females. In recordings from body wall muscles, Tmep mutants show substantial hyperexcitability, with many postsynaptic potentials fired in response to a single stimulation, consistent with a role for Tmep in restraining synaptic excitability. Additional branches and satellite boutons at Tmep mutant neuromuscular junctions are consistent with an activity-dependent synaptic overgrowth. Tmep is expressed in endosomes and synaptic vesicles within motor neurons, suggesting a possible role in synaptic membrane trafficking. Using RNAi knockdown, we show that Tmep is required in motor neurons for proper larval locomotion and excitability, and that its reduction increases levels of presynaptic calcium. Locomotor defects can be rescued by presynaptic knockdown of endoplasmic reticulum calcium channels or by reducing evoked release probability, further suggesting that excess synaptic activity drives behavioral deficiencies. Our work establishes a critical function for Tmep in the regulation of synaptic transmission and locomotor behavior.

Role of Diffusion Weighted MRI (DW-MR) in Detection of Satellite Lesions Not Detected with Multiphase CT Scans in Hepatoblastoma and Its Implications for Management.

To evaluate the role of diffusion-weighted magnetic resonance imaging (DW-MR) in hepatoblastoma as compared to multiphase contrast enhanced computed tomography (CECT) scans for detection of satellite lesions. In this prospective study onnew cases of hepatoblastoma, multiphase CECT scans and DW-MR were performed before initiation of chemotherapy. Results of interpretation were compared for detection of satellite lesions. PRETEXT grouping and risk categorization was done according to SIOPEL based on CECT scan. Nine boys and 1 girl with hepatoblastoma, with median age of 11.5 mo were included. All patients were stratified as high-risk group with 2 (20%) in PRETEXT II and 8 (80%) in PRETEXT III. In 2 of 10 (20%) patients, additional satellite lesions were detected on DW-MR, which upgraded their stage. One of the two patients had one satellite lesion identified on CECT, while additional seven satellite lesions were identified on DW-MR imaging. For the other patient, CECT showed no satellite lesion while DW-MRdetected six satellite lesions. MRI has become the gold standard investigation for evaluation of hepatoblastoma. DW-MR, which is a contrast free technique, is a better tool for assessment of satellite lesions which are usually missed on CECT. Thiswould help in proper staging, planning of management and prognostication.

Potential of Mapping Global Soil Texture Type From SMAP Soil Moisture Product: A Pilot Study

Soil texture and associated thermal and hydraulic parameters are key to land surface processes. Current global soil datasets are derived from limited soil samples, which are not only very costly but also prone to large uncertainties. While it is difficult to directly retrieve soil properties through satellite remote sensing, this study explores the feasibility of mapping global soil type and thereby corresponding soil texture through the Soil Moisture Active Passive (SMAP) soil moisture product without reference to soil samples. Specifically, for each grid-cell, 12 USDA (U.S. Department of Agriculture) soil types are first used to drive the Noah-MP land surface model and then the optimal one is obtained by referring to a four-year (2015-2018) SMAP soil moisture time series. The proposed scheme can reasonably map global distribution of soil types in terms of sand/clay content and porosity that are close to the Global Soil Dataset for Earth System Models (GSDE) dataset and outperform the one used in GLDAS/Noah model. The result of this pilot study is very encouraging as it purely relies on satellite data, which is especially important for remote areas where few soil samples are available and conventional soil datasets may have large biases. Further improvements may be achieved upon improved soil organic matter parameterization, through land data assimilation and by considering additional satellite information.

Abstract PO-025: Implementing evidence-based interventions (EBI) to increase uptake of fecal immunochemical test (FIT) colorectal cancer (CRC) screening in Vulnerable Populations

Abstract Purpose: We partnered with a local Federally Qualified Health Center (FQHC) to test implementation of evidence-based interventions (EBI) promoting Fecal Immunochemical Test (FIT) CRC screening in an environment in which colonoscopy has been the prevailing screening strategy. We report on implementation adaptations and preliminary results. Background: Sociocultural and medical concerns are barriers to colonoscopy uptake in some populations. An additional barrier to CRC screening is system level capacity for colonoscopy that results in a back log of cases and long wait times. With Covid-19, the additional backlog in overdue CRC screening has underscored the need to expand FIT testing capacity to address screening needs and to pre-empt further racial/ethnic and SES disparities in CRC outcomes. This trial tests the unique and additive value of multiple EBIs for increasing CRC screening (primarily through FIT testing, but also colonoscopy when indicated) while evaluating the success of implementing these approaches. EBIs include the use of medical reminders, addressing the structural barriers (social determinants of health [SDOH]), and assistance from community health workers. Methods: Participants (3500), ages 45-75, were identified from a large FQHC in New Haven, CT and determined to be overdue for CRC screening. Participants were randomly assigned to one of the four arms of the study: 1) Provider reminder (overdue for CRC screening) only; 2) Provider Reminder + SDOH short message and one-size-fits all link to resources; 3) Provider Reminder + SDOH short message and offer for individualized navigation (trained navigators from local community) to address SDOH and other barriers; 4) Provider Reminder + offer to participate in a CRC educational program as phase 2 of the NCI's Screen to Save program (not an EBI). Preliminary data on uptake of CRC screening will be presented. Results: With input from stakeholders, we have: 1) lowered age eligibility from 50 to 45 to align with new guidelines; 2) expanded the target population to 2 additional satellite clinics, more than doubling the proposed study enrollment; 3) incorporated design changes in the patient reminders. The collaboration between research team and clinician stakeholders has been critical in minimizing disruptions to clinical workflow while assuring fidelity to the evidence-based interventions. Preliminary outcomes (within one month of intervention) on uptake of intervention across the 4 arms of the study, i.e., referral for CRC screening and test completion will be presented. Conclusion: The unique challenges of this urban community of primarily African American/Black, Hispanic/Latinx and/or low socioeconomic status individuals stem from the disproportionate burden of SDOH barriers. Findings will inform primary care setting implementation of EBIs to address the anticipated increase in disparities in CRC screening, exacerbated by COVID-19 changes in health care access and utilization, as well as the increased demand associated with the change in guidelines. Citation Format: Beth A. Jones, Sakinah C. Suttiratana, Sally A. DeGiovanni, Levita Y. Robinson, Michael J. Couturie, Denise Stevens, Monique K. Stefanou, Jose DeJesus, Eduardo Reyes, Jonathan Colon, Maryanne Cosgrove, Steven J. Parra. Implementing evidence-based interventions (EBI) to increase uptake of fecal immunochemical test (FIT) colorectal cancer (CRC) screening in Vulnerable Populations [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-025.

Expand and Renewal of Analyzed Satellite Image and Service

In this study, additional satellite analysis data in 2019, 2020, and 2021 were generated using Landsat-8 and Sentinel-2 satellite images. We additionally employed 19 types of satellite analysis methods, and generated totally 57 cases of satellite analysis data for three years. In addition, 34 types of satellite analysis data were updated using 2021 satellite data. In conclusion, a total of 91 cases of satellite analysis data were generated. The coverage of the study is the entire South Korea. The spatial resolution and the coordinate system were 30 m and UTM-K (EPSG: 5179) respectively. The products are provided as the entire South Korean and regional data, respectively. In addition, it is provided in three data types: ASCII, ArcGIS Grid, and GeoTIFF as same as last distribution. All satellite image analysis data can be downloaded free of charge from the Environmental Big Data website (www.bigdata-environment.kr), an environmental business big data platform.

Mode Coupling at around M-Point in PZT.

The question of the microscopic origin of the M-superstructure and additional satellite peaks in the Zr-rich lead zirconate-titanate is discussed for nearly 50 years. Clear contradiction between the selection rules of the critical scattering and the superstructure was found preventing unambiguous attributing of the observed superstructure either to the rotation of the oxygen octahedra or to the antiparallel displacements of the lead cations. Detailed analysis of the satellite pattern explained it as the result of the incommensurate phase transition rather than antiphase domains. Critical dynamics is the key point for the formulated problems. Recently, the oxygen tilt soft mode in the PbZrTiO (PZT2.4) was found. But this does not resolve the extinction rules contradiction. The results of the inelastic X-ray scattering study of the phonon spectra of PZT2.4 around M-point are reported. Strong coupling between the lead and oxygen modes resulting in mode anticrossing and creation of the wide flat part in the lowest phonon dispersion curves is identified. This flat part corresponds to the mixture of the displacements of the lead and oxygen ions and can be an explanation of the extinction rules contradiction. Moreover, a flat dispersion surface is a typical prerequisite for the incommensurate phase transition.

Exploiting Wind-Turbine-Mounted Base Stations to Enhance Rural Connectivity

Despite global connectivity being one of the main requirements for future generations of wireless networks driven by the United Nation's Sustainable Development Goals, telecom providers are economically discouraged from investing in sparsely populated areas, such as rural and remote ones. Novel affordable and sustainable paradigms are thus indispensable to enhance the cellular infrastructure in such areas and bridge the digital divide when compared with urban ones. We investigate the use of wind-turbine-mounted base stations (WTBSs) as a cost-effective solution for regions with high wind energy potential, since it could replace or even outperform current solutions requiring additional cell towers (CTs), satellites, or aerial BSs. Indeed, conveniently installing BS equipment on wind generators would allow the transceivers to reach sufficient altitudes and easily establish line-of-sight channels within large areas. We also propose insightful simulation results for realistic case studies based on datasets for wind speed and population densities as well as wind turbines' and CTs' locations within specific Argentinian and Ethiopian exurban regions. By doing this, we hope to prove the feasibility and effectiveness of this solution and stimulate its implementation.

Differential Interferometric Synthetic Aperture Radar data for more accurate earthquake catalogs

The accuracy of earthquake catalogs limits the reliability of earthquake hazard assessment and the comprehensive understanding of earthquake mechanisms. Current seismic catalogs are based on the inversion of seismic wave data. The accuracy of their source parameters, which reflect the quantity and layout of seismic stations, and the crustal velocity model used, are often highly uncertain. The open source and popularization of Interferometric Synthetic Aperture Radar (InSAR) deformation data offer the potential to provide more accurate source parameters for earthquake catalogs. In this study, we used same-source InSAR data and a consistent processing approach (i.e., the same sampling, inversion algorithm, and processing flow) to obtain the fault slip models and source parameters of 56 earthquakes, covering most of earthquakes observed by the Sentinel-1 since 2014; these were then used to form a unified InSAR earthquake catalog (U-InSAR). We then compiled a second InSAR earthquake catalog (C-InSAR) based on the source parameters of an additional 164 earthquakes inverted using InSAR deformation data from various sources by previous studies, among which 45 earthquakes included additional Global Navigation Satellite System (GNSS) data. The C-InSAR catalog was used to evaluate the impact of data sources and processing approach on the consistency of InSAR catalogs; we found no significant differences between the U- and C-InSAR catalogs. Secondly, the combined U- and C-InSAR catalogs were compared with seismological catalogs, and showed significantly improved seismic source locations, depths, moment magnitudes, fault strikes, fault dips, and fault rakes. Our results confirm the rationality and feasibility of constructing earthquake catalogs using source parameters from a variety of InSAR data sources and inversion algorithms. We emphasize that InSAR catalogs can provide an important supplement, improvement, and/or correction to seismological catalogs, and can provide important basic data for more refined and reliable research on earthquake mechanisms and hazard assessments. Finally, we set up a preliminary sharing and distribution system for InSAR-based catalogs.

Histological Analysis and Gene Expression of Satellite Cell Markers in the Pectoralis Major Muscle in Broiler Lines Divergently Selected for Percent 4-Day Breast Yield.

Muscle development during embryonic and early post-hatch growth is primarily through hyperplastic growth and accumulation of nuclei through satellite cell contribution. Post-hatch, muscle development transitions from hyperplasia to hypertrophic growth of muscle fibers. Commercial selection for breast yield traditionally occurs at ages targeting hypertrophic rather than hyperplastic growth. This has resulted in the production of giant fibers and concomitant challenges with regard to muscle myopathies. The current study investigates the impact of selection during the period of hyperplastic growth. It is hypothesized that selection for percentage breast yield during hyperplasia will result in an increased number of muscle cells at hatch and potentially impact muscle fiber characteristics at processing. This study characterizes the breast muscle histology of three broiler lines at various ages in the growth period. The lines include a random bred control (RAN) as well as lines which have been selected from RAN for high (HBY4) and low (LBY4) percentage 4-day breast yield. Post-rigor pectoralis major samples from six males of each line and age were collected and stored in formalin. The sample ages included embryonic day 18 (E18), post-hatch day 4 (d4), and day 56 (d56). The samples were processed using a Leica tissue processor, embedded in paraffin wax, sectioned, and placed on slides. Slides were stained using hematoxylin and eosin. E18 and d4 post-hatch analysis showed advanced muscle fiber formation for HBY4 and immature muscle development for LBY4 as compared to RAN. Post-hatch d56 samples were analyzed for fiber number, fiber diameter, endomysium, and perimysium spacing. Line HBY4 had the largest muscle fiber diameter (54.2 ± 0.96 μm) when compared to LBY4 (45.4 ± 0.96 μm). There was no line difference in endomysium spacing while perimysium spacing was higher for HBY4 males. Selection for percentage 4-day breast yield has impacted the rate and extent of muscle fiber formation in both the LBY4 and HBY4 lines with no negative impact on fiber spacing. The shift in processing age to later ages has exposed issues associated with muscle fiber viability. Selection during the period of muscle hyperplasia may impact growth rate; however, the potential benefits of additional satellite cells are still unclear.

COPERNICUS AND THE ENERGY CHALLENGE

Abstract. The energy sector will drastically change in the following years; multiple agreements have been signed by countries with the purpose to reduce carbon emission and contain the global temperature increase. Besides, in the next years the energy demand will increase with the growth of the Information and Communications Technology sector. To combine these two aspects, future energy needs to be produced with renewable resources and less with fossil fuels. An opportunity to discover and plan the use of renewable energy resources are geospatial data derived from satellite acquisitions. The European Earth Observation programme Copernicus provides multiple datasets in an Open Science approach. Within this paper, multiple datasets offered by Copernicus services are presented in relation to their exploitation for the energy system analysis, with a particular attention to renewable energy. The datasets will be analysed according to their properties and possibility of usage. Additional Copernicus satellite derived data that can benefit the emerging topic of the food-energy-water nexus are finally presented to point out significant development in the energy sector which is recently claiming growing attention.

The Surface Water and Ocean Topography (SWOT) Mission River Database (SWORD): A Global River Network for Satellite Data Products

AbstractThe upcoming Surface Water and Ocean Topography (SWOT) satellite mission, planned to launch in 2022, is the first mission to focus on measuring hydrological processes in Earth's surface water. As such, SWOT will vastly expand observations of global rivers ≥100 m wide. SWOT will provide a variety of data products, including a global vector river product containing water surface elevation (WSE), width, slope, and estimated discharge. Practical application and consistency of the SWOT vector products requires a prior global river network database divided into reaches. Here, we introduce the SWOT River Database (SWORD). SWORD will serve as the framework for the SWOT river vector products consisting of river reaches (∼10 km long) and nodes (∼200 m spacing). We generate SWORD by combining several global river‐ and satellite‐related data sets into one congruent product. When defining river reaches, we incorporate natural and human‐created river obstructions, basin boundaries, tributary junctions, and SWOT orbit track information. SWORD contains a total of 213,485 reaches and 10.7 million nodes. Globally, 77.3% of river reach lengths are between 10 and 20 km with a median reach length of 10.5 km. 95% of river reaches ≥10 km will have sufficient SWOT observations to provide discharge estimates at least once per orbit cycle. SWORD also contains many useful hydrologic and morphological attributes and is designed to be expandable in the future. Even before the launch of SWOT, it can serve as a framework for global hydrologic analyses using models, in situ measurements, and additional satellite observations.

The Use of InSAR Phase Coherence Analyses for the Monitoring of Aeolian Erosion

Aeolian erosion occurring in sand deserts causes significant socio-economical threats over extensive areas through mineral dust storm generation and soil degradation. To monitor a sequence of aeolian erosion in a sand desert area, we developed an approach fusing a set of remote sensing data. Vegetation index and Interferometric Synthetic Aperture Radar (InSAR) phase coherence derived from space-borne optical/SAR remote sensing data were used. This scheme was applied to Kubuqi Desert in Inner Mongolia where the effects of activity to combat desertification could be used to verify the outcome of the approach. We first established time series phase coherence and conducted a functional operation based on principal component analysis (PCA) to remove uncorrelated noise. Then, through decomposition of vegetation effect, where a regression model together with the Enhanced Vegetation Index (EVI) was employed, we estimated surface migration caused by aeolian interaction, that is, the aeolian erosion rate (AER). AER metrics were normalized and validated by additional satellite and ground data. As a result, the spatiotemporal migration of the target environment, which certainly induced dust storm generation, was traced and analyzed based on the correlations among surface characteristics. It was revealed that the derived AER successfully monitored the surface changes that occurred before and after the activities to combat desertification in the target area. Employing the established observation scheme, we expect a better understanding of the aeolian process in sand deserts with enhanced spatio-temporal resolution. In addition, the scheme will be beneficial for the evaluation of combating desertification activities and early warning of dust storm generations.

Moiré superlattice on the surface of a topological insulator

Twisting van der Waals heterostructures to induce correlated many-body states provides a novel tuning mechanism in solid-state physics. In this work, we theoretically investigate the fate of the surface Dirac cone of a three-dimensional topological insulator subject to a superlattice potential. Using a combination of diagrammatic perturbation theory, lattice model simulations, and ab initio calculations we elucidate the unique aspects of twisting a single Dirac cone with an induced moir\'e potential and the role of the bulk topology on the reconstructed surface band structure. We report a dramatic renormalization of the surface Dirac cone velocity as well as demonstrate a topological obstruction to the formation of isolated minibands. Due to the topological nature of the bulk, surface band gaps cannot open; instead, additional satellite Dirac cones emerge, which can be highly anisotropic and made quite flat. We discuss the implications of our findings for future experiments.

Serial blood sampling effects in rat embryo-fetal development studies for toxicokinetics

Serial blood sampling for toxicokinetics is generally conducted in regulatory embryo-fetal development (EFD) studies in rats. EFD studies are designed to detect the potential adverse effects of pharmaceuticals on pregnant females and their fetuses; this information is useful for understanding the relationships between systemic exposure levels and toxicity profiles. However, additional satellite pregnant females are needed for toxicokinetics because comprehensive information regarding the potential impact of serial blood sampling on pregnant females is scarce. Here, in this study, we investigated the potential impact of serial blood sampling in pregnant female rats using a typical EFD study design. Additionally, we investigated the additional endpoints (clinical pathology, organ weights, and histopathology) that were deemed likely to be sensitive to blood sampling. Results indicated that serial blood sampling in pregnant females induced physiological adaptive changes and did not affect the general endpoints in EFD studies. Nevertheless, inclusion of satellite groups in EFD studies may be a more prudent approach considering the physiological changes in pregnant females and potential off-target effects of candidate pharmaceuticals. These results provide background information on the impact of serial blood sampling in pregnant females and will be useful to design the regulatory EFD studies.