The Transport History of Alluvial Fan Sediment Inferred From Multiple Geochronometers

We present a multi-chronometer approach to refine the age of an alluvial fan and to infer sediment transport and deposition history in the Anza Borrego Desert region of Southern California. We measure in situ produced cosmogenic carbon-14 (14C) from boulders on the fan surface and infrared stimulated luminescence (IRSL) ages from single feldspar grains within the alluvium. Our new IRSL age [5.3 ± 0.5 ka (±1σ)] is in excellent agreement with existing uranium-series [U-series; 5.3 ± 0.2 (±2σ)] ages of pedogenic carbonates. The IRSL and U-series ages show that in situ 14C measurements [6.6 ± 1.1 ka (±1σ)] from boulders contain inherited nuclides from prior exposure in the upstream catchment, much like measurements of the longer-lived nuclide, beryllium-10 (10Be). However, in situ 14C ages are closer to the preferred ages inferred from IRSL and U-series and with less scatter than comparative 10Be ages. Our data demonstrate that a multi-geochronometer approach will produce ages of alluvial fan surfaces with the greatest degree of confidence. We then apply the paired 14C and 10Be concentrations to infer the prior exposure and storage duration of the sampled boulders of 3.1 ± 3.2 and 4.6 ± 2.3 Kyr, respectively. A mixture model analysis of the single grain IRSL ages suggests bimodal storage durations prior to remobilization with peaks at ca. 2 and 10 Kyr. We demonstrate that cosmogenic nuclide inheritance and single grain IRSL equivalent dose distributions can provide additional information regarding sediment transport history prior to deposition on the alluvial fan

Observation of tW production in the single-lepton channel in pp collisions at root s=13 TeV

A measurement of the cross section of the associated production of a single top quark and a W boson in final states with a muon or electron and jets in proton-proton collisions at root s = 13 TeV is presented. The data correspond to an integrated luminosity of 36 fb(-1) collected with the CMS detector at the CERN LHC in 2016. A boosted decision tree is used to separate the tW signal from the dominant t (t) over bar background, whilst the subleading W+jets and multijet backgrounds are constrained using data-based estimates. This result is the first observation of the tW process in final states containing a muon or electron and jets, with a significance exceeding 5 standard deviations. The cross section is determined to be 89 +/- 4 (stat) +/- 12 (syst) pb, consistent with the standard model.Peer reviewe

XAI Model for Accurate and Interpretable Landslide Susceptibility

Landslides are notoriously difficult to predict. Deep neural networks (DNNs) models are more accurate than statistical models. However, they are uninterpretable, making it difficult to extract mechanistic information about landslide controls in the modeled region. We developed an explainable AI (XAI) model to assess landslide susceptibility that is computationally simple and features high accuracy. We validated it on three different regions of eastern Himalaya that are highly susceptible to landslides. SNNs are computationally much simpler than DNNs, yet achieve similar performance while offering insights regarding the relative importance of landslide control factors in each region. Our analysis highlighted the importance of: 1) the product of slope and precipitation rate and 2) topographic aspects that contribute to high susceptibility in landslide areas. These identified controls suggest that strong slope-climate couplings, along with microclimates, play more dominant roles in eastern Himalayan landslides. The model outperforms physically-based stability and statistical models.Comment: 47 pages (including SI section); 3 main figures; 14 supplementary figures; 9 supplementary table

Development of Chaos Terrain as Subaqueous Slide Blocks in Galilaei Crater, Mars

Chaos terrain, expressed as enigmatic blocky landscapes on Mars, has poorly understood origins. Several hypotheses have been put forward to explain chaos terrain formation, but none fully account for the morphologies observed in Galilaei crater, the focus of this study. Previously inferred to be a paleolake, Galilaei crater hosts chaos terrain composed of kilometer-scale, disorganized blocks around the southern and southeastern margin of the crater. Blocks are concentrated near the base of the crater wall, with blocks of decreasing size extending into the crater interior. The crater wall slope in regions where these chaos blocks are present is notably lower than in regions where blocks are absent. Based on the observed morphologies, we propose the chaos terrain in Galilaei crater formed by gravity-driven slope failure and down-slope transport as subaqueous landslides and mass flows, initiated at a time when the paleolake level was still high. We propose and discuss Earth analogs for the observed terrain and use mapping-constrained spatiotemporal relationships to reconstruct the sequence of landform development. Subaqueous landslides represent an uncommonly invoked mechanism to explain chaos terrain on Mars, reinforcing the idea that one mechanism cannot explain the diversity of this enigmatic terrain

Expert Consensus on COVID-19 Vaccination in Korean Adolescents: A Modified Delphi Survey

The effectiveness of coronavirus disease 2019 (COVID-19) vaccines had been shown in many studies in adult population, however, the real-world evidence in the childhood population was scarce. We aimed to organize the collective expert’s opinions on adolescent vaccination against COVID-19 in Korea, therefore to guide the vaccination policy in the setting of available evidence. The Delphi panels responded that adolescents were greatly impacted by the quarantine measures, and COVID-19 is an important health problem for adolescents. Panels responded that in general, the benefits of the COVID-19 vaccine overweigh the potential risks in Korean adolescents. Continuing monitoring of available data is needed to provide the best vaccination practices in adolescents guided by the updated evidence

Petrological and Mineralogical Characteristics of Exposed Materials on the Floors of the Lavoisier and Surrounding Craters

Five floor-fractured craters (FFCs), Lavoisier crater and four craters surrounding it (Lavoisier C, Lavoisier E, Lavoisier F, and Lavoisier H), are distributed along the boundary between the northwestern part of the Oceanus Procellarum and the highlands. This study examines the uplifted or exposed materials on the fractured floors of these five impact craters using petrological, mineralogical, and morphological analyses. We inferred the processes that uplifted or exposed the materials from the subsurface to the crater floor using the Chandrayaan-1 Moon Mineralogy Mapper (M3) level 1b (thermally and topographically corrected spectral radiance) data and level 2 (spectral reflectance) data. The elemental abundances, petrological, and mineralogical characteristics of the study regions were mapped. We confirm that mare basalts and dark mantle deposits exist on the floors of these five craters. These two materials (mare basalts and dark mantle deposits) were used to identify minerals exposed on the floor surface of craters using spectral reflectance spectra. Two mineral groups were identified: pigeonite (or orthopyroxene in norite (low-Ca pyroxene) occurred in the craters Lavoisier, Lavoisier F, and Lavoisier H, and subcalcic augite (high-Ca pyroxene) occurs in the craters Lavoisier C and E. Our approach demonstrates that the characterization of uplifted or exposed surface minerals using elemental maps, spectral parameter composite maps, and reflectance spectra can provide information critical for prospective studies involving lunar geology and in situ resource utilization

The chemical, mechanical, and hydrological evolution of weathering granitoid

Surprisingly few studies connect the chemical, mechanical, and hydrological evolution of rock as it weathers to saprolite and soil. We assess this coevolution in granodiorite from Monterey Peninsula, California, by measuring changes in bulk chemistry, mineralogy, volumetric strain, the oxidation state of Fe in biotite crystals, tensile strength, abrasion rate, connected porosity, and hydraulic conductivity in samples covering a range of weathering grades. We identify the oxidative dissolution of biotite as the key chemical reaction because of the volumetric expansion that accompanies formation of altered biotite and precipitation of ferrihydrite. We show how the associated accumulation of elastic strain produces an energy density that is sufficient to support rock fracturing over length scales equivalent to constituent crystals. The resulting intragranular and intergranular cracking profoundly reduces tensile strength and increases the abrasion rate, connected porosity, and hydraulic conductivity of the rock matrix. These changes increase the rate of plagioclase weathering, and ultimately the rock disintegrates into grus and clay. Major changes in rock properties can occur with only minor element leaching, and the threshold behavior of weathering that arises from the coevolution of chemical, hydrological, and mechanical properties may be difficult to capture using simplified weathering models that fail to incorporate these properties. Our results, which combine the mechanical and hydrological evolution of weathering rock with more common measurements of chemical changes, should help to more accurately model the effects of, and mechanical and hydrological feedbacks upon, chemical weathering of rock

Past and future impact of glacial erosion in Forsmark and Uppland. Final report

The following report constitutes a final report of a comprehensive study on denudation and glacial erosion conducted at Forsmark and in the surrounding Uppland province, Sweden, between 2015 and 2019. The aim was to quantify the amount of past denudation at the Forsmark site and the broader Uppland region, with special focus on glacial erosion, by employing a range of methodologies. The methods included geomorphological mapping and analysis of the bedrock surface and Quaternary deposits, cosmogenic exposure dating, bedrock fracture mapping, and shallow bedrock stress modelling. The results were also used together with results from a long-term climate modelling study to quantify the potential amount of glacial erosion at Forsmark over the coming one million years. The study was initiated by Jens-Ove Näslund (SKB) and it was jointly designed by Jens-Ove Näslund, Adrian Hall (Stockholm University), Karin Ebert (Södertörn University), Bradley Goodfellow (Stockholm University, SGU), Clas Hättestrand (Stockholm University), Jakob Heyman (University of Gothenburg) and Arjen Stroeven (Stockholm University). Adrian Hall coordinated the scientific work within the study, and also conducted the studies on long-term burial and erosion history (Chapter 2) and glacial erosion (Chapter 4). Karin Ebert developed the digital elevation models of the unconformity and derived the glacial erosion estimates derived from summit erosion surfaces. Bradley Goodfellow contributed across the project and conducted the study of topographic stress perturbation, with mathematical modelling by Seulgi Moon (University of California, Los Angeles) (Chapter 3). Clas Hättestrand developed geomorphological maps of the unconformity and of glacial bedforms. Maarten Krabbendam (British Geological Survey) contributed to Chapter 2 on the longterm burial and erosion history and to Chapter 4 on glacial erosion and mapped landforms associated with glacial ripping in Uppland. Sample site selection and cosmogenic nuclide sample collection was carried out by Jakob Heyman, Bradley Goodfellow, Arjen Stroeven, Marc Caffee and Adrian Hall. Jakob Heyman conducted the modelling of cosmogenic nuclide erosion and burial histories. Bradley Goodfellow was involved in cosmogenic nuclide sample preparation at Purdue University. Reporting and interpretation of cosmogenic nuclide results in Chapter 5 was done by Jakob Heyman, Arjen Stroeven and Bradley Goodfellow. All authors contributed to the final revision of the report. The study includes several additional important contributions. Marc Caffee (Purdue University) was responsible for all cosmogenic isotope laboratory analyses and guided and participated in the discussions of interpretation of results (Chapter 5). Stephen Martel (University of Hawaii) and Taylor Perron (Massachusetts Institute of Technology) were involved in the fracture mapping and modelling (Chapter 3). Mikis van Boeckel (Stockholm University) produced many of the figures in the report from digital elevation model data from the Swedish mapping, cadastral and land registration authority (Lantmäteriet) and SGU. In connection to the present study, two additional studies have been performed employing similar methods (e.g. geomorphological analysis and cosmogenic exposure dating) for studying the sub- Cambrian unconformity in the Trollhättan area in south-western Sweden. The two associated studies will be published in separate reports (Goodfellow et al. 2019, Hall et al. 2019a). The results will be used, together with other published scientific information, for constructing future scenarios of climate and climate-related processes in SKB’s work on assessing long-term safety of nuclear waste repositories in Sweden. The safety assessments performed for the planned repository for spent nuclear fuel in Forsmark, Sweden, cover a total time span of one million years. Since this time span covers the timescales relevant for glacial cycles, the effect of future glacial erosion needs to be analysed in the safety assessments. In this context, the present study provides important results on the potential amount of glacial erosion that may be expected in the topographical, geological, and glaciological setting of the Forsmark site. A separate study models changes in climate over the next 1 million years and has been published ahead of this report (Lord et al. 2019)

Expression Quantitative Trait Loci (eQTL) Mapping in Korean Patients With Crohn's Disease and Identification of Potential Causal Genes Through Integration With Disease Associations

Background Expression quantitative trait loci (eQTL) datasets have extensively been used to help interpret genome-wide association study signals. Most eQTL analyses have been conducted with populations of European ancestry. Objective To determine the most functionally relevant genes at the Crohn's disease (CD) loci identified in genome-wide association studies (GWAS) involving Asian populations and to find novel disease-associated genes, we conducted an eQTL analysis. Methods eQTL analysis was performed using whole-blood RNA-sequencing of 101 Korean patients with CD. FastQTL was used for a pair-wise genome analysis of similar to 6.5 M SNPs and similar to 22 K transcripts. Results We identified 135,164 cis-eQTL and 3,816 eGenes with a false discovery rate less than 0.05. A significant proportion of the genes identified in our study overlapped with those identified in previous studies. The significantly enriched pathways of these 3,816 eGenes included neutrophil degranulation and small molecule biosynthetic process. Integrated analysis of CD GWAS with Korean eQTL revealed two putative target genes, TNFSF15 and GPR35, at two previously reported loci, whereas TNFSF15 only with the whole blood data from the Genotype-Tissue Expression (GTEx) project, highlighting the utility of building a population-specific data set, even of modest size. The risk alleles of these genes were found to be associated with lower expression levels of TNFSF15 and GPR35, respectively. Our eQTL browser can be accessed at "". Conclusion This resource would be useful for studies that need to employ genome-wide association analyses involving Asian populations.Y