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Impacted by the global COVID-19 crisis and its sociopolitical shockwaves, pre-existing physical mobility patterns and traditional study-abroad experiences have been thoroughly disrupted and transformed. US higher education institutions have utilized the practices of transnational hybrid learning to sustain the quality and progress of international higher education. This article focuses on a study programme that integrates online and offline learning in Shanghai, China, coordinated by a non-profit international higher education exchange agency in partnership with eight US universities and one Chinese university from August 2020 to June 2021. Through semi-structured interviews with 32 Chinese students, this article finds that transnational hybrid learning offers students greater geographical and time flexibility, room for self-paced learning and controls on health risks while ensuring face-to-face interactions and physical activities. In addition, the localization of international education might motivate Chinese students to consider their career development that balances their interests and career prospects in response to political and economic uncertainties. However, the communication and learning gaps, weakened intercultural communication, sustained sociocultural alienation and contradictions of two sociocultural contexts render the overall programme experience less desirable. In sum, this article identifies the potential of virtual mobility beyond geographical and policy constraints in transforming and reimagining the practices of transnational higher education in a post-pandemic world.

Heavy metal contamination and its detrimental health effects are a growing concern globally. Several metal mitigation systems and regulatory approaches have been implemented to minimize the negative impacts on human health. However, none of these function at maximum efficiency, mainly due to the lack of accurate information about metal speciation. Therefore, there is a critical need to develop novel, cheap, efficient, and robust metal detecting sensors. In this study, we describe the application of a nanopipet based electrochemical sensor to detect aqueous Cd(ii) ions. The inner radius of our nanopipets is ∼300 nm, and the fundamental mechanism behind our sensor's response is ion transfer between two immiscible electrolyte solutions (ITIES). The absence of redox behavior makes ITIES an excellent, attractive electrochemical tool to study various ions in aqueous solutions. In this study, we used 1,10-phenanthroline as our ionophore in the organic phase (dichloroethane) to facilitate the transfer of Cd(ii) ions from the polar aqueous phase to the less polar organic phase. Unlike previous studies, we characterized our nanopipet in complicated matrices, including, but not limited to, tris buffer and artificial seawater. We performed quantitative assessments to determine our sensor's limit of detection, stability, sensitivity, and selectivity. We further show that our nanosensor can detect free Cd(ii) ions in the presence of strong complexing agents such as ethylenediaminetetraacetic acid, 2,3-dimercaptosuccinic acid

Introduction Functional gastrointestinal disorders (FGID) including impaired rectal evacuation are common in patients with Hypermobility Spectrum Disorder (HSD) or Hypermobile Ehlers-Danlos Syndrome (hEDS). The effect of connective tissue pathologies on pelvic floor function in HSD/hEDS remains unclear. We aimed to compare clinical characteristics and anorectal pressure profile in patients with HSD/hEDS to those of age and sex matched controls. Methods We conducted a retrospective review of all FGID patients who underwent high resolution anorectal manometry (HR-ARM) and balloon expulsion test (BET) for evaluation of impaired rectal evacuation. Patients with HSD/hEDS were age and sex matched to a randomly selected cohort of control patients without HSD/hEDS. An abnormal BET was defined as the inability to expel a rectal balloon within 2 minutes. Wilcoxon rank sum test and Fisher’s exact test were used to make comparisons and logistic regression model for predictive factors for abnormal evacuation. Results A total of 144 patients (72 with HSD/hEDS and 72 controls) were analyzed. HSD/hEDS patients were more likely to be Caucasian (p p p Conclusions These results suggest anorectal pressure profile is not compromised by connective tissue pathologies in HSD patients. Whether concurrent psychosomatic disorders or musculoskeletal involvement impact the pelvic floor function in these patients needs further investigation.

The Ocona River Valley, in the Arequipa Department in southern Peru, extends over 150 km from the Pacific coast to its headwaters in the Andes Mountains. While traditionally sparsely populated with farmers and crawfish fishermen, the valley has seen a large population growth in the last 20 years as small gold mines have developed. This change poses the opportunity to evaluate three research questions: How do geologic hazards and risks increase from mining activity? How does unplanned urban development affect risks? How do landforms restrict development and thereby increase risks? The combination of climate, topographic, and hydrologic conditions result in widespread hazards from debris flows, collapsible soils, erosion, rockfall, flooding, and liquefaction. We have developed maps of these hazards for three communities where mines have recently developed, Secocha, Alto Molino, and San Juan de Chorunga, and then we conducted a risk analysis for changing conditions, termed “Risk–Risk” analysis. Because of the lack of vegetation on mountain slopes, mining operations typically only affect rockfall hazards, mostly in the immediate vicinity of the mines and in the nearby runout zones. However, increased population and associated settlement infrastructure is constrained by steep slopes and regularly-flooded valleys, so residents live in fan and terrace areas with substantially increased risks from debris flows and collapsible soils and moderately increased risks from flooding and rockfall.

A scientific hazard zoning of debris flows can ensure that human activities are not performed therein, thereby reducing economic loss as much as possible. In this study, by considering the formation background conditions of mountain hazards and dynamic rainfall conditions, the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model (TRIGRS) and Flow path assessment of gravitational hazards at a Regional scale (Flow-R) are organically combined to establish a new coupled model for debris flow dynamic hazard assessment from the viewpoint of landslides providing the material source of debris flows. The coupled model was employed in Qingping township, Sichuan province of China, which was severely damaged by the “5·12” Wenchuan earthquake in 2008. Evaluation results show that the accuracy of the coupled model is 87.98%, which is significantly higher than that of the static Flow-R model (75.51%). This study not only considers the effect of the formation condition of mountain hazards and rainfall-induced shallow landslides on the source of debris flows, but also realises real-time hazard assessment and prediction of group-occurring debris flows. The coupled model used in this study provides a new perspective and is paramount for improving the accuracy and reliability of debris flow hazard assessment.

Postural orthostatic tachycardia syndrome (POTS) is an autonomic disorder that affects multiple organs, including the gastrointestinal system. These patients often have multiple GI complaints with a severe impact on their quality of life. GI dysmotility patterns in POTS remains poorly understood and difficult to manage. The aim of this study was to investigate the diagnostic yield of wireless motility capsule in patients with gastrointestinal symptoms and POTS, with use of a symptomatic control group without POTS as a reference. We retrospectively reviewed the charts of patients who had both autonomic testing and wireless motility capsule between 2016 and 2020. The two groups were divided into those with POTS and those without POTS (controls) as diagnosed through autonomic testing. We compared the regional transit times and motility patterns between the two groups using the data collected from wireless motility capsule. A total of 25% of POTS patients had delayed small bowel transit compared to 0% of non-POTS patients (p = 0.047). POTS patients exhibited hypo-contractility patterns within the small bowel, including decreased contractions/min (2.95 vs. 4.22, p = 0.011) and decreased motility index (101.36 vs. 182.11, p = 0.021). In multivariable linear regression analysis, migraine predicted faster small bowel transit (p = 0.007) and presence of POTS predicted slower small bowel transit (p = 0.044). Motility abnormalities among POTS patients seem to affect mostly the small bowel and exhibit a general hypo-contractility pattern. Wireless motility capsule can be a helpful tool in patients with POTS and GI symptoms as it can potentially help guide treatment.

Characterizing the zone of damaged and altered rock surrounding a fault surface is highly relevant to geotechnical and geo-environmental engineering works in the subsurface. Evaluating the uncertainty associated with 3D geologic modeling of these fault zones is made possible using the popular and flexible input-based uncertainty propagation approach to geologic model uncertainty assessment – termed probabilistic geomodeling. To satisfy the automation requirements of probabilistic geomodeling while still preserving the key geometry of fault zones in the subsurface, a clear and straightforward modeling approach is developed based on four geologic inputs used in implicit geologic modeling algorithms (surface trace, structural orientation, vertical termination depth and fault zone thickness). The rationale applied to identifying and characterizing the various sources of uncertainty affecting each input are explored and provided using open-source codes. In considering these sources of uncertainty, a novel model formulation is implemented using prior geologic knowledge (i.e., empirical and theoretical relationships) to parameterize modeling inputs which are typically subjectively interpreted by the modeler (e.g., vertical termination depth of fault zones). Additionally, the application of anisotropic spherical distributions to modeling disparate levels of information available regarding a fault zone's dip azimuth and dip angle is demonstrated, providing improved control over the structural orientation uncertainty envelope. The probabilistic geomodeling approach developed is applied to a simple fault zone geologic model built from historically available geologic mapping data, allowing for a visual comparison of the independent contributions of each modeling input on the combined model uncertainty, revealing that vertical termination depth and structural orientation uncertainty dominate model uncertainty at depth, while surface trace uncertainty dominates model uncertainty near the ground surface. The method is also successfully applied to a more complex fault network model containing intersecting major and minor fault zones. The impacts of the model parameterization choices, the fault zone modeling approach and the effects of fault zone interactions on the final geologic model uncertainty assessment are discussed.

Synthetic Aperture Radar (SAR) interferometry is a formidable technique to monitor surface deformation with a millimeter detection resolution. This study applies the Persistent Scatter-Interferometric Synthetic Aperture Radar (PSInSARTM) technique to measure ground subsidence related to a twin-tunnel excavation in downtown Los Angeles, USA. The PSInSARTM technique is suitable for urban settings because urban areas have strong reflectors. The twin tunnels in downtown Los Angeles were excavated beneath a densely urbanized area with variable overburden depths. In practice, tunneling-induced ground settlement is dominantly vertical. The vertical deformation rate in this study is derived by combining Line of Sight (LOS) deformation velocities obtained from SAR images from both ascending and descending satellite orbits. Local and uneven settlements up to approximately 12 mm/year along the tunnel alignment are observed within the allowable threshold. No severe damages to aboveground structures were reported. Furthermore, ground movements mapped one year before tunnel construction indicate that no concentrated ground settlements pre-existed. A Machine Learning (ML)-based permutation feature importance method is used for a parametric study to identify dominant factors associated with the twin-tunneling induced uneven ground subsidence. Six parameters are selected to conduct the parametric study, including overburden thickness, i.e., the thickness of artificial fill and alluvium soils above the tunnel springline, the distance between the two tunnel centerlines, the depth to the tunnel springline, building height, the distance to the tunnel, and groundwater level. Results of the parametric analysis indicate that overburden thickness, i.e., the thickness of artificial fill and alluvium soils above the tunnel springline, is the dominant contributing factor, followed by the distance between tunnel centerlines, depth to the tunnel springline, and building height. Two parameters, the distance to the tunnel, and the groundwater level, play lesser essential roles than others. In addition, the geological profile provides comprehension of unevenly distributed ground settlements, which are geologically sensitive and more concentrated in areas with thick artificial fill and alluvium soils, low tunnel depth, and high groundwater levels.

Landslide hazards occur throughout the world. There were 18,000 deaths worldwide due to landslides between 1998 and 2017 (World Health Origination, n.d.). Furthermore, landslides are often ...

Outburst sediments are widely distributed in the Upper Jinsha River in the Southeastern (SE) Tibetan Plateau. In order to understand the sedimentary characteristics of these sediments, gravel fabric, particle size distribution and quartz sand surface textures were used to analyze the mesotextures and microtextures of the Xuelongnang outburst sediments. It was determined that these sediments usually have a short transport distance, and are distributed over a distance of approximately 3.5 km. The gravel fabric and particle size distribution analysis represent the different mesotextures with different transport distances and suggest gradually changing hydrodynamic conditions. The statistical data of quartz surface textures exhibit the transformation process of quartz sands by outburst flood. The variation from abundant sub-angular shapes (> 75%); to common V-shaped percussion cracks, solution crevasse, medium relief, and chatter marks (50% to 75%); to rare meandering ridge, underwater polished surface, large conchoidal fracture (> 100 μm), directional etch pits, and crystalline overgrowths (< 5%), present the features in different combinations to other sedimentary environments. The microtexture characteristics of landslide-dam outburst deposits are also consistent with those of the mesotextures. As the distance from the residual dam increased, the quartz grain microtextures showed gradual or abrupt changes, such as increased frequencies of V-shaped percussion cracks, decreased frequencies of the adhering particles, and growth of the solution crevasses. These findings could potentially be used as a discriminant mark to distinguish outburst sediment from other types of sediments, e.g., subaqueous, eolian, glacial, etc.

Backward erosion piping (BEP) is a common hazard along artificial levees in the Lower Mississippi Valley (LMV). This study applies an empirical assessment of overbank deposit thickness, als...

Landslide-dammed lake outburst floods (LLOFs) may pose serious safety threats to nearby residents and their livelihoods, as well as cause major damages to the downstream areas in mountainous regions. This study presents the Diexi ancient landslide-dammed lake (DALL) in the Upper Minjiang River at the eastern margins of the Tibetan Plateau, which was known to an estimated previous maximal lake area of 1.1 × 107 m2 and an impounded volume of 2.9 × 109 m3. Then, at approximately 27 ka BP, the ancient landslide dam failed and catastrophic LLOFs occurred. It was determined that the peak discharge of the Diexi ancient LLOFs could be reconstructed using regression, parametric, and boulder competence approaches. The reconstructed maximum peak discharge might be 72,232.66 m3/s, with an average velocity of 17.23 m/s, indicating that the Diexi ancient LLOFs were the most gigantic outburst floods to occur in the Upper Minjiang River Valley since the Late Pleistocene Period. The differences in the widths and slopes within the former and the later reaches of the dam indicated that the geomorphic influences on the river channel resulting from the DALL and its LLOFs have existed for tens of thousands of years. These findings were of major significance in deepening the understanding of the existence and disappearances of important river-knickpoints on a time scale of tens of thousands of years.

Backward erosion piping (BEP) is a form of internal erosion and common failure mode along levees. Despite over a century of study, predicting where BEP will initiate is still a considerable challenge. This study proposes a new model for predicting BEP initiation focused on the widest range of applicability. A logit model is trained using data from 15 sites along the Lower Mississippi Valley. The included parameters are independent of geography or geological regime and exhibit recorded or suspected correlations to BEP. Three significant factors (95% confidence interval) are retained for the final model: cumulative clay thickness within the blanket (odds ratio (OR) 0.520), critical gradient (OR 0.001) and exit gradient (OR 63.15). Receiver operating characteristics analysis indicates an area under the curve of 0.823. The model demonstrates 71% classification accuracy, a dramatic 10% increase over previous logit model attempts. Model results are most applicable within 150 m of the levee toe to predict new incidents of BEP initiation. The final model is a useful tool for BEP assessment and mitigation efforts.

Postural orthostatic tachycardia syndrome (POTS) is an autonomic disorder that affects multiple organs, including the gastrointestinal system. These patients often have multiple GI complaints with a severe impact on their quality of life. GI dysmotility patterns in POTS remains poorly understood and difficult to manage.The aim of this study was to investigate the diagnostic yield of wireless motility capsule in patients with gastrointestinal symptoms and POTS, with use of a symptomatic control group without POTS as a reference.We retrospectively reviewed the charts of patients who had both autonomic testing and wireless motility capsule between 2016 and 2020. The two groups were divided into those with POTS and those without POTS (controls) as diagnosed through autonomic testing. We compared the regional transit times and motility patterns between the two groups using the data collected from wireless motility capsule.A total of 25% of POTS patients had delayed small bowel transit compared to 0% of non-POTS patients (p = 0.047). POTS patients exhibited hypo-contractility patterns within the small bowel, including decreased contractions/min (2.95 vs. 4.22, p = 0.011) and decreased motility index (101.36 vs. 182.11, p = 0.021). In multivariable linear regression analysis, migraine predicted faster small bowel transit (p = 0.007) and presence of POTS predicted slower small bowel transit (p = 0.044).Motility abnormalities among POTS patients seem to affect mostly the small bowel and exhibit a general hypo-contractility pattern. Wireless motility capsule can be a helpful tool in patients with POTS and GI symptoms as it can potentially help guide treatment.

The 2008 Wenchuan earthquake triggered tens of thousands of landslides, resulting in rich loose materials for the 8.13 debris flows. Longchi Town in southwest China’s Sichuan Province was o...

The accuracy of a debris-flow susceptibility assessment model can not be achieved to an acceptable level without rigorously selecting/processing model input parameters and reliably validating the results with ground truth. In this study, a modified logistic regression model was applied to examine the debris-flow susceptibility in the semi-arid mountainous areas of the southeast Tibetan Plateau, taking the case of the Benzilan-Changbo segment of the Jinsha River. The logistic regression model validation was supported by a field investigation and interpreting aerial photographs. The frequency ratio method was adapted for the sensitivity analysis of ten predisposing factors, including a factor of human activities that has never been considered in previous studies for the selected study area. The model with the highest prediction accuracy (83%) was obtained by comparing 55 possible combinations of the ten factors evaluated using a receiver operating characteristic curve technique. Composite analysis and random sample testing were also conducted to verify the reliability of the susceptibility assessment. The prediction results showed that the actual debris-flow area accounted for 92% of the total predicted debris-flow area. In summary, this study reveals that: (1) the highest susceptibility area was mainly distributed in the northeast and middle riparian zones, partially scattered in the southwest. Human activity was found to be closely related to the probability of debris flow occurrences; (2) under the two situations of independent and index combination participation evaluation, the performances of the same related factors showed largely different effects on the assessment results, which reflected the interrelation and interaction of the factors causing the debris flow; (3) the accuracy of the modified logistic regression model increased by 15%, when compared with the index entropy model in a previous study, and the reasons for this were discussed in the current study. The modified model, along with its enhanced validation process, could be easily extended to other regional mass movement susceptibility analyses.

A large number of the landslide dams located on the major rivers at the southeastern margin of the Tibetan Plateau have been previously identified through remote sensing analysis and field investigations. The Xuelongnang paleolake was one of the lakes formed by these landslide dams in the upper Jinsha River, where the association of a relict landslide dam, lacustrine sediment, and outburst sediment is well preserved. This preservation provides an opportunity to better understand the formation, evolution, and longevity of a large landslide-dammed lake in the upper Jinsha River. It was inferred that the Xuelongnang dammed lake may have been formed by an earthquake-induced paleoavalanche. The surface area of the lake at its peak was estimated at 7.0 × 106 m2, and the corresponding volume was approximately 3.1 × 108 m3. Two outburst flood events were determined to have occurred during the life span of the lake. Based on the 18 ages obtained from optically stimulated luminescence (OSL) and carbon-14 (14C) dating combined with stratigraphic sequences observed in the field, the paleolandslide-dammed lake was formed at approximately 2.1 ka and subsequently breached locally. The dammed lake was sustained for a period of some 900 years based on the chronological constraining. This study confirms that a major landslide-dammed lake can be sustained for at least hundreds of years and breached by several dam breaks in multiple periods, which contributed to the preservation of the knickpoints at millennial scale along the major rivers in the study area.

There is increasing recognition of the value from incorporating local and scientific hazard knowledge for disaster risk management, but practical integration remains limited. Much management activity remains underpinned by information deficit thinking, which inherently valorizes scientific knowledge and devalorizes local knowledge. To move away from deficit thinking, we develop the concept of “cross-validation” as a step toward integrating types of hazard knowledge. Rather than science validating local knowledge, cross-validation is multidirectional and focuses on identifying the strengths of each knowledge type and their areas of complementarity, to achieve a more complete hazard understanding. We applied the cross-validation approach to analyze geohazard knowledge in two case study sites in southern Peru. We identified substantial agreement around the most prominent local hazards, providing mutual reinforcement of each type of knowledge. We also identified complementary facets, where strengths in one knowledge type compensated for limitations in the other. The cross-validation approach shows promise as a first step toward incorporating knowledge, providing an opportunity to establish the foundation from which practical integration can build.

This study reveals that a distinct damming incident occurred during a prehistory period (approximately 30 ka BP) in the upper Minjiang River, at the southeastern margin of the Tibetan Plateau, which formed a giant dammed lake. It can be inferred that paleoseismic induced major landslides were the direct cause of the river damming. The dammed lake breached and caused a large outburst flood at about 27 ka BP. Between the section of the prehistoric ancient dam-body and its downstream areas (5 km), an abundance of diamicts consisting of a poor-sorted wide range of particle sizes, including gravel, sand, and minor silt and clay, have been observed. The outburst deposits in the Diexi area maybe divided into two periods: the thick outburst deposits represented the earlier and largest dammed-break event, and the deposit terrace was due to the subsequent and smaller dammed-break event. The sedimentary structures of the outburst deposits included imbrication, cavitation, matrix, and massive structures, as well as gravel support-stacked structures. Furthermore, a special sedimentary structure became evident, consisting of a rhythmite interbedded structure composed of a coarser gravel layer, and a finer sand and gravel layer, with no sand lens formed within the layers. This special structure can potentially provide an important original criterion for the outburst deposits in this area. The two types of facies associations have been recorded which indicate contrasting sediment transport regimes. The characteristics of boulder facies were most likely associated with hyperconcentrated flood flows. However, the finer-grained Gm/Gfm/GRm facies, which overlaid the Bcm facies, were determined to represent the waning stage of the flooding events. The delicate structures, as well as the absence of coarse components in the Sh facies, indicated an episode of accumulations, which was subsequent to the deposition of the underlying Bcm facies. The results of this study potentially provide important implications for the interpretation of the diamicts in the Diexi area. The grain-size frequency curves of the outburst deposits in the Diexi area were found to all be bimodal (a main peak and an inconspicuous sub-peak). These findings indicated a poorly sorted sedimentary structure. It was found that, from the upstream segment to the downstream segment, the gravel sediment became gradually lessened, while the fine-grained sediment increased. Additionally, the outburst flood hydrodynamic intensity was found to have gradually become weakened.

Introduction: Choledocholithiasis, the presence of gallstones in the common bile duct (CBD), commonly presents as abdominal pain, jaundice, and an elevated bilirubin and is further evaluated with abdominal ultrasound and consideration of MRCP or ERCP based on clinical predictors. Herein, we describe a novel approach to abdominal pain and hyperbilirubinemia due to SARS-CoV-2 (Covid 19) which led to additional imaging and an incidental malignancy diagnosis. Case Description/Methods: A 52-year old man with a history of chronic hepatitis B virus presented with one week of abdominal pain and jaundice. Admission labs were significant for a total bilirubin of 4.1mg/dL, and positive screening for Covid 19. Abdominal ultrasonography demonstrated a dilated CBD to 1.7cm. His presentation was highly suggestive of choledocolithiasis by ASGE criteria, but ERCP was deferred to abide by hospital-wide precautions at the time. As a result, the patient underwent confirmatory testing with MRCP, which showed no choledocholithiasis but demonstrated a 4.1cm enhancing lesion abutting the pancreatic body. Subsequent abdominal computed tomography found a 3.3cm soft tissue density encasing the celiac axis, suggesting lymphoma. Endoscopic ultrasound (EUS)-guided biopsy of the pancreatic lesion demonstrated an unreported 3.1cm liver mass, which was biopsied. On further review of imaging, the liver mass was not appreciated on ultrasound, CT or MRCP. It was suspected that the hyperbilirubinemia was likely due to this intrahepatic mass, described as poorly differentiated adenocarcinoma. Due to the early diagnosis he was able to be discharged and follow up with oncology to better guide his future directed therapy. Discussion: The Covid 19 pandemic forced all aspects of healthcare to adapt. Given gastroenterology's invasive nature this also encouraged gastroenterologists to consider alternative pathways of treatment aside from the published algorithms in place. This case demonstrates how deviating from the ASGE guidelines resulted in a cascade of diagnostics which led to an eventual malignancy diagnosis which may have been otherwise missed or delayed. Guidelines are established on large sets of data and patient prognostic indicators which to our knowledge have not considered infection status or isolation needs. Further research in this area may result in amending guidelines to address isolation status and reminds practitioners to consider the patient before them and their unique patient needs. (Figure Presented) .

The distribution of volcanogenic massive sulfide (VMS), porphyry-epithermal, Alaska-type ultramafic-mafic complexes, intrusion-related Au, and granitoid Sn-W ore deposits in southwest Alaska supports current metallogenic models linking the formation of these deposit types to the emplacement of different suites of igneous rocks during the evolution of this convergent plate margin. Regional-scale aeromagnetic data provide a continuous set of observations over the deposits and show contrasting patterns over the igneous rock suites hosting the various deposit types. Combined with surface geologic data and regional metallogenic constraints, aeromagnetic data—filtered to enhance the anomalous magnetic field and map magnetic domains—were used to produce a mineral potential map across this accreted island-arc setting. The reduced-to-pole, upward continuation, and total horizontal gradient transform maps show anomalies that could represent porphyry-epithermal deposits within the intraoceanic- and continental-arc terranes. The tilt derivative transform highlights lineaments within the back arc that may represent zones with potential for VMS deposits. The truncations of tilt derivative lineaments outline a major magnetic domain boundary between the back-arc and craton margin, which is prospective for granitoid Sn-W deposits. Annular tilt derivative highs outline granitoids that could be associated with intrusion-related Au deposits within the craton margin. Shallow, magnetite-rich Alaska-type ultramafic-mafic complexes are mapped by their short-wavelength, high-amplitude anomalies. Successful mineral potential mapping across southwestern Alaska as performed in the present study suggests that filtered aeromagnetic data can be effectively used in mineral exploration in convergent continental margin settings.

During high-water events, backward erosion piping poses a serious threat to the stability of artificial levee structures. Sand boils forming on the land-side of levees are presently the best indicator of active backward erosion piping, but surveying these features across extensive levee works during flood events is time and resource intensive. Using geographic information system (GIS) technology and a probabilistic statistical analysis, this study assimilates geologic, environmental, and spatial relationship data to generate models to predict the likelihood of sand boil development. Data such as unfavorable geologic orientation, normalized difference vegetation index (NDVI), and blanket thickness are assigned to over 100 km of levees along the Waal and IJssel rivers of the Netherlands. A binary logistic regression is then applied to identify factors with statistically significant relationships to historical sand boil locations, and generate a predictive model using the significant factors. The logit models generally support previous findings indicating unfavorable orientation of geologic deposits and NDVI have a significant relationship with the spatial occurrence of sand boils. Despite this statistical significance, the best predictive model yields an accuracy only 10.83% higher than a random prediction model. Given variance in factors between models, sand boil formation appears to be dependent on a combination of conditions experienced on a local scale. Furthermore, attempting to predict sand boils using a single logit model across multiple geologic environments reduces the influence of region-specific conditions, yielding a less effective model than evaluating the systems individually.

Incessant flooding is a major hazard in Lagos State, Nigeria, occurring concurrently with increased urbanization and urban expansion rate. Consequently, there is a need for an assessment of Land Use and Land Cover (LULC) changes over time in the context of flood hazard mapping to evaluate the possible causes of flood increment in the State. Four major land cover types (water, wetland, vegetation, and developed) were mapped and analyzed over 35 years in the study area. We introduced a map-matrix-based, post-classification LULC change detection method to estimate multi-year land cover changes between 1986 and 2000, 2000 and 2016, 2016 and 2020, and 1986 and 2020. Seven criteria were identified as potential causative factors responsible for the increasing flood hazards in the study area. Their weights were estimated using a combined (hybrid) Analytical Hierarchy Process (AHP) and Shannon Entropy weighting method. The resulting flood hazard categories were very high, high, moderate, low, and very low hazard levels. Analysis of the LULC change in the context of flood hazard suggests that most changes in LULC result in the conversion of wetland areas into developed areas and unplanned development in very high to moderate flood hazard zones. There was a 69% decrease in wetland and 94% increase in the developed area during the 35 years. While wetland was a primary land cover type in 1986, it became the least land cover type in 2020. These LULC changes could be responsible for the rise in flooding in the State.

The “East Muddy Creek Landslide Complex” in Gunnison County, Colorado, USA destroyed Colorado State Highway 133 from 1986 to 1987 and has been investigated over decades during different periods of reactivation. This paper presents a case study of novel landslide activity recognition related to the landslide complex using Advanced Land Observing Satellite-1 (ALOS-1) Interferometric Synthetic Aperture Radar (InSAR) analysis. We compare the result from ALOS-1 InSAR analysis to landslide recognition investigations from traditional field methods for ground motions at a watershed scale. Line of Sight (LOS) velocity mapping is used to characterize displacement zonation, failure modes, and hazard assessment activities. Mass wasting estimates using existing geological modeling are discussed in terms of potential of landslide element dynamics. ALOS-1 InSAR analysis reveals newly detected ground displacement at very slow to extremely slow velocities with a significantly increased spatial extent. The implications of expanded displacement activity in the context of landslide geomorphology, mountain denudation, exhumation, and future monitoring efforts for hazard and risk assessment are also examined and discussed.

Natural resources embrace a broad array of categories, including agricultural, conservational, forestry, oceanic, water, energy, and mineral resources. This article only focuses on the last three. Traditional methods for natural resource management include, but are not limited to, geophysical exploration, field geological mapping, geochemical analysis, and aero-photo interpretations. Natural resource-related research is by nature a spatial problem. Integration of field survey data and other pertinent information can be a time-consuming task by traditional ways. With the help of GIS, most of the tasks can be conducted in ways that are nearly impossible in traditional methods. Three case studies of GIS application in natural resource analyses are presented in this article to demonstrate the GIS applications in compiling, integrating, analyzing, and visualizing natural resource data.

The semiarid mountainous region is characterized by sparse vegetation and rich source of loose deposits, which is favorable for the formation of debris flows. Benzilan-Changbo segment in the upper reaches of Jinsha River is selected in this study. Based on field investigation and interpretation of remote sensing images, the development characteristics of regional debris flows in the semiarid area are studied. Six assessment indices are selected, including lithology, structural fault, slope gradient, relative height of the watershed, annual average rainfall and normalized vegetation index. Based on GIS, the assessment model of debris flow susceptibility for semiarid region was built using AHP (analytical hierarchy process) method, so as to obtain the grid map of debris-flow susceptibility zoning in the study area. The study area is divided into small watershed as one unit for regional statistical analysis and classification. Finally, the debris-flow susceptibility assessment map based on small watershed analysis can be obtained. The assessment results show that the very high susceptibility area and high susceptibility area of debris flow are mainly distributed in the northeast, central and southwest banks of Jinsha River, with an area of about 1040.9 km2, accounting for 35.7% of the study area. The area of low susceptibility and very low susceptibility for debris flow covers about 1341.7 km2, accounting for 46.0% of the study area, mainly distributed in the high altitudes of western and southeastern study area. Through examination, the prediction successful rate of debris flow susceptibility is 62.2%. The present actual areas of debris flow with extremely high and high susceptibility are about 651.4 km2, accounting for 51.1% of the total assessed debris-flow area, indicating the favorable comparative test results of susceptibility assessment against real debris flow occurrence.

Debris flow is one of the most common natural hazards in the semiarid mountainous areas of the Southeast (SE) Tibetan Plateau. Because of unique geology, geomorphology, and diverse climate conditions, debris-flow susceptibility in the mountainous areas shows significant regionalism. In this study, an index entropy model is adapted for sensitivity analysis of the impact factors of debris flows in the semiarid areas, and the Benzilan-Changbo segment of the upper reaches of the Jinsha River are selected as an area of interest in a case study. Based on the sensitivity analysis, six factors, including, lithology, slope gradient, slope aspect, relative relief, catchment system geomorphologic entropy, monthly average precipitation (June–September), and normalized difference vegetation index (NDVI) are considered debris-flow susceptibility assessment factors. The results show that landform, lithology, and vegetation are the three most important factors affecting the susceptibility of the debris flow in se...

There is currently a resurgence of interest in developing covalent drugs due to the high potency, good selectivity, and prolonged effects which may results in less-frequent drug dosing and wider therapeutic windows for patients. BridGene Biosciences established a novel IMTACTM (Isobaric Mass Tagged Affinity Characterization) platform for covalent drug discovery. Using IMTACTM platform, an intelligently designed drug-like probe with alkyne tag is able to “fish out” and identify proteins covalently bound to probes from live cells which enables us to discover druggable opportunities across the entire proteome. There are several advantages of IMTACTM : 1. Discover ligands for unliganded or undruggable targets; 2. Reduce the time and cost of lead discovery; 3. Identify additional targets of drugs or clinical candidates; 4. Build ligand-target interaction database and guide drug design. Using IMTACTM platform, our covalent library is screened in various live cells including cancer immune, and neuronal cell lines. The hit rate of IMTAC screening is about 20%, and the targets discovered by IMTACTM includes GMPS, Rictor, BTK, FABP5, ALDH, FUS, MIF and etc. Given the drug-like probe design, the probes can have nanomolar potency on the targets. And the drug like probe design minimizes the SAR efforts of developing a hit to a drug. IMTACTM platform allows us to expand the therapeutic applications of small molecule drugs to a new horizon. Citation Format: Heather Ha, Robert Stanley, Qian Cai, Wendy Zhou, Hang Chen, Irene Yuan, Ping Cao. Small molecule covalent drug discovery by IMTACTM [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A136. doi:10.1158/1535-7163.TARG-19-A136

During construction of the Uma Oya Multipurpose Development Project, excavation of a headrace tunnel through highly tectonized metamorphic rock was slowed by repeated major water ingress events. In total, these events resulted in an estimated aquifer depletion of over 9 million m3, causing widespread surface subsidence. Persistent scatterer (PS) time series analysis of interferometric synthetic aperture radar (InSAR) scenes acquired by Sentinel-1 between July 28, 2016, and January 7, 2018, has revealed an ∼15 km2 area of subsidence near reported water ingress locations, with a maximum line-of-sight subsidence value of 4.3 cm. A four-dimensional (4-D) filtering method based on averaging spatial and temporal pixel neighbors was applied to the unwrapped PS pixels, significantly reducing noise from sources that appear randomly in spatial and temporal domains and increasing the ability to accurately identify the onset of subsidence and track surface volume loss over time. A maximum average subsidence rate of 0.15 mm / day coincides with maximum tunnel discharge measurements, indicating that rock mass consolidation occurred as a result of rapid pore-pressure drawdown within an interconnected discontinuity network and led to fracture closure. The observed subsidence is punctuated by localized maxima and extends in a northwest–southeast orientation, suggesting that the extent of subsidence is governed by previously mapped structural trends of similar orientations. These results highlight the value of the 4-D filtering approach in processing InSAR PS data to help determine the magnitude and extent of surface subsidence.

Ground-based interferometric radar (GBIR) monitoring was conducted on a slow-moving, translational failure landslide in Granby, Grand County, Colorado, USA. Radar monitoring was completed over two separate surveys in 2011 using a tripod mounted real aperture sensor. The purpose of this work is to evaluate GBIR as a temporally dense monitoring technique for monitoring landslide displacement and compare the monitoring results to ongoing GPS based surveying methods to verify measured displacements. We discuss the strengths and limitations of GBIR displacement monitoring with a variety of available sensors, and place this monitoring platform, sensor, and workflow into context of previous slope stability monitoring with GBIR. For both surveys, displacement time series were created through a small temporal baseline stacking to reduce noise and maintain high temporal resolution. The results of the displacement time series were compared to average displacement rates derived from GPS based surveying. An overall verification of radar and GPS derived displacement rates was achieved, and identifies important differences relating to the precision and uncertainty of the two techniques. This work demonstrates GBIR monitoring capability of establishing high temporal resolution on tracking variable rates of landslide movements. Spatial modeling of total observed displacements was completed for both surveys verifying a conceptual model of uniform translational landslide movement, providing greater confidence for mitigation planning.

The GPRI2 Ground-Based Real-Aperture radar was deployed in Seattle over a 6-week period during March and April 2015 to measure sub-millimeter scale subsidence related to construction of the Alaskan Way Viaduct and Seawall Replacement Program (AWVSRP). The radar was located on the mid-level roof of the Smith Tower overlooking Pioneer Square at an altitude of about 75 meters above street level. Radar images at 2 hour intervals were processed to obtain Line-of-Sight (LOS) deformation maps. Point target analysis was used to identify stable targets and to mitigate variations in propagation path length due to atmospheric changes. Geolocation and rectification of the more than 100,000 monitored points was carried out using a LiDAR DEM.

Florida’s aquifer system exhibits spatially variable hydrogeological characteristics including shallow depth to aquifer and karst features. These characteristics contribute to groundwater vulnerability to nitrogen contamination and thus warranting vulnerability studies that allow zonation of areas into different levels of susceptibility to contamination from land use practices. A geographic information system (GIS)-based nitrogen fate and transport model (GIS-N model) was developed to assess aquifer vulnerability to contamination by examining the fate and transport of ammonium and nitrate from onsite wastewater treatment systems (OWTS). The GIS-N model analyzes fate and transport of nitrogen through the unsaturated zone using a simplified advection–dispersion equation. Operational inputs considered in this model include wastewater effluent ammonium or nitrate concentration, hydraulic loading rates, and OWTS locations. The GIS-N model considers two different modeling approaches: single step and two step. The single-step model considers a denitrification process assuming all the ammonium is converted to nitrate before land application, while the two-step model uses ammonium as an input and considers nitrification followed by denitrification. The resulting maps were classified into vulnerability zones based on the Jenks’s natural breaks in the data histogram. It was revealed that groundwater vulnerability from OWTS is sensitive to the depth to water table, first-order reaction rates, and parameters controlling the time and amount of conversion. Nitrate concentration is highest in areas with shallow water table depth. The vulnerability maps produced in this study will facilitate planners in making informed decisions on placement of OWTS and on groundwater protection and management.