Moderate Events Research Articles

Stratification of residual thromboembolic risk among anticoagulated atrial fibrillation patients: a hierarchical cluster analysis from a global, real-world population

Abstract Background Assessment of residual thromboembolic risk among atrial fibrillation (AF) patients despite being on oral anticoagulants (OACs) poses a significant challenge. This study utilises a hierarchical cluster analysis approach to identify risk phenotypic profiles in a global prospective AF registry. Methods Data were drawn from recently diagnosed non-valvular AF patients receiving OACs, as recorded in phases II and III of the GLORIA-AF (Global Registry on Long-Term Oral Anti-thrombotic Treatment in Patients With Atrial Fibrillation) registry. A hierarchical cluster analysis based on patient demographics was performed to identify distinct phenotypes. The incidence and risks of thromboembolic events (ischaemic stroke, transient ischaemic attack, or systemic embolism) and relevant events (major bleeding and all-cause death) were compared across clusters. Results The study included 22,410 patients (mean age 70±8 years; 56% male), from which 5 phenotypes were delineated: Cluster 1 ("uncontrolled hypertension"), Cluster 2 ("young with a history of coronary artery disease"), Cluster 3 ("young and obese"), Cluster 4 ("frailty"), and Cluster 5 ("non-paroxysmal AF with tachycardia"). Cluster 4 was associated with the highest rates of thromboembolic events (1.66/100 person-years), major bleeding (1.92/100 person-years), and all-cause mortality (6.02/100 person-years). Conversely, Cluster 3 showed the lowest risk profiles across all outcomes (thromboembolic events: 0.64 events/100 person-years, major bleeding: 0.83 events/100 person-years, and all-cause death: 1.44 events/100 person-years). Cluster 1 displayed a moderate thromboembolic event rate (1.04/100 person-years), although lower rates were observed in Clusters 2 and 5 (Figure 1). Conclusions Hierarchical cluster analysis effectively identified distinct phenotypes within a global AF population, offering valuable insights for stratifying the risks of residual thromboembolic events and other significant outcomes in anticoagulated AF patients (Figure 2).Figure 1Figure 2

Assessing the impact of a large multi-purpose reservoir on flood control under moderate and extreme flood conditions

ABSTRACT This study offers a detailed examination of the Eupen dam’s role in flood mitigation in Belgium’s Vesdre valley, analysing 18 moderate and extreme flood events from 1995-2022. Notable aspects of the methodology include adjustments for an ungauged sub-basin and a mass-balance approach to compute the unknown outflow data from the inflow time-series and reservoir level data. These 18 events evidence the dam’s performance hitherto, with respect to peak discharge attenuation (9-91%), peak delay (0-68 hours), outflow volume reduction (2-94%), as well as discharge reductions associated with various return periods (38-51%), given its multipurpose objectives. The research details how the dam’s effectiveness varies with operational decisions and antecedent reservoir conditions, marking a departure from conventional studies that tend to generalise data across multiple dams and events. By focusing on individual events, the study provides insights into the nuanced interplay between dam operations and flood management, demonstrating the benefits and limitations of multi-purpose reservoirs in flood control.

Analysis of the interrelationship between precipitation and confirmed dengue cases in the city of Recife (Brazil) covering climate and public health information

Large-scale epidemics of arboviruses, such as dengue, have heightened societal awareness regarding the necessity of combating the primary transmission vectors. Equally critical is the identification of environmental conditions and variables that influence vector population dynamics. Aedes aegypti, the primary vector of arboviruses such as dengue and Zika in Brazil, is closely associated with the climatic and geographical conditions of urban environments. This study examines the relationship between precipitation and confirmed dengue cases in Recife (Brazil), employing regression and quantile analyses to evaluate the influence of meteorological conditions on the disease’s spread. The findings reveal a direct correlation between monthly averages of precipitation and confirmed cases, although this is apparent only when excluding years of epidemic peaks. The highest number of cases generally aligns with the rainy season, and the lowest with the dry season, with weak, moderate and strong precipitation events being closely linked to increased dengue incidence. However, notable discrepancies were identified: four out of six major outbreaks occurred in drier months, challenging the assumption of a straightforward relationship between rainfall and dengue incidence. These findings underscore the multifaceted nature of dengue dynamics, suggesting that while precipitation plays a significant role, other factors, including serotype circulation and broader climatic phenomena, are equally critical in driving outbreaks. This complexity highlights the need for a more comprehensive understanding of the mechanisms influencing dengue epidemics.

Coral reef community recovery trajectories vary by depth following a moderate heat stress event at Swains Island, American Samoa

Coral reef community recovery trajectories vary by depth following a moderate heat stress event at Swains Island, American Samoa

Accuracy evaluation and comparison of GSMaP series for retrieving precipitation on the eastern edge of the Qinghai-Tibet Plateau

Study RegionMin River Basin on the eastern Qinghai-Tibet Plateau. Study FocusPrecipitation is critical for hydrological processes, making accurate data essential for water management and flood forecasting. Satellite precipitation products offer valuable high-resolution spatiotemporal information, with the GSMaP series being widely used. However, comprehensive evaluations of different versions are limited. This study assesses the accuracy of Gauge and MVK products (versions 06, 07, and 08) across spatial and temporal scales and evaluates their performance in detecting precipitation events of varying intensities. New Hydrological Insights for the Study Region(1) GSMaP versions 06 and 07 exhibit higher detection rates for precipitation events, with POD values exceeding 0.8, while version 08 has a lower false alarm rate, with FAR values below 0.15. (2) GSMaP products are more successful in capturing precipitation events during the rainy season than the dry season. (3) With increasing elevation, the Gauge product consistently maintains a high hit rate and reduced false alarm rate, whereas the MVK product's hit rates improve. (4) For different rainfall intensities, GSMaP products more accurately detect moderate and heavy rain events, with the Gauge product outperforming the MVK product in terms of accuracy. These insights enhance the understanding of GSMaP product performance on eastern edge of the Qinghai-Tibet Plateau, aiding in improved water management practices.

Safety, tolerability, pharmacokinetics and pharmacodynamics of a single intravenous dose of SHR-1707 in healthy adult subjects: two randomized, double-blind, single-ascending-dose, phase 1 studies

BackgroundSHR-1707 is a novel humanized anti-Aβ IgG1 monoclonal antibody that binds to Aβ fibrils and monomers to block the formation of Aβ plaques or to promote the microglial phagocytosis of Aβ. Preclinical studies showed that SHR-1707 reduced brain Aβ deposition in 5xFAD transgenic mice. Herein, we conducted two phase 1 studies to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of a single intravenous dose of SHR-1707 in healthy adult subjects.MethodsTwo randomized, double-blind, single-ascending-dose, phase 1 studies were conducted in China (Study CHN) and Australia (Study AUS). Study CHN consisted of 2 parts. In Part 1, eligible healthy young adults (18–45 years) were sequentially randomized 8:2 to receive SHR-1707 (five cohorts: 2, 6, 20, 40, and 60 mg/kg) or placebo in each cohort; in Part 2, elderly subjects (55–80 years) were randomized 8:4 to receive SHR-1707 (20 mg/kg) or placebo. A similar design was used in Study AUS, but with only healthy young adults enrolled across three dosing cohorts (2, 20, and 60 mg/kg).ResultsSixty-two (part 1/2, n = 50/12; age range, 18–42/55–63 years) and 30 subjects (age range, 18–42 years) received SHR-1707 or placebo in Study CHN and Study AUS, respectively. In Study CHN, all treatment-related adverse events (TRAEs) were mild, with the most common being transient laboratory abnormalities. In Study AUS, TRAEs were mostly mild (1 moderate event each with SHR-1707/placebo); the most common TRAEs with SHR-1707 were dysgeusia and fatigue (8.3% each). In both studies, the exposure of SHR-1707 increased in a slightly greater than dose-proportional manner over the dose range of 2–60 mg/kg in young adults; there was a dose-dependent increase in plasma Aβ42 concentration following SHR-1707 administration compared with the placebo group. The safety and PK and PD profiles of SHR-1707 in the elderly subjects were consistent with the younger counterpart at the same dose level. No ethnic difference in safety, PK and PD of SHR-1707 was observed.ConclusionsA single intravenous dose of SHR-1707 at 2–60 mg/kg was safe and well tolerated in healthy young adult and elderly subjects. The PK and PD profiles are supportive for further clinical development.Trial registrationNCT04973189 (retrospectively registered on Jul.21, 2021) and NCT04745104 (registered on Feb.6, 2021) on clinicaltrials.gov.

The Streamflow Response to Multi‐Day Warm Anomaly Events: Sensitivity to Future Warming and Spatiotemporal Variability by Event Magnitude

AbstractPersistent warm temperature anomalies can drive streamflow in regions where snow and glacier melt are important constituents of streamflow. However, the spatiotemporal variability of the streamflow response depends on both the magnitude of the forcing temperature anomalies and the nature of the underlying hydrological system. Here we ask: when, where, and for what magnitude of temperature anomalies will the streamflow response change most rapidly under warming? We use observed streamflow and temperature for 868 basins across Canada to quantify the streamflow response during warm temperature anomalies and how such responses vary in space, time, and by anomaly magnitude. We first identify two temporal modes of the streamflow response, one in autumn and one in spring, the relative strength of which varies by climate. We then use sinusoidal approximations of seasonal temperature cycles to characterize the sensitivity of such modes to changes in annual temperature. At individual basins, we find that relative to moderate warm events, the streamflow response to more extreme warm events is more sensitive to changes in mean annual temperatures, and this sensitivity is greatest in the coastal, southern, and central regions of Canada. Our results have implications for how the hydrological impacts of extreme events, such as heatwaves, will change in space and time under future climate change.

A Comparison of Post-Procedural Hemoglobin in Catheter-Directed Thrombolysis vs. Large-Bore Aspiration Thrombectomy for Acute Pulmonary Embolism

PurposeTo compare changes in hemoglobin (HB) following catheter-directed thrombolysis (CDL) vs. large-bore aspiration thrombectomy (LBAT) of acute pulmonary embolism (PE). Materials and MethodsSingle-center retrospective review of acute high and intermediate-risk PE patients treated with CDL or LBAT between 12/2009 and 9/2023. The LBAT group was divided according to usage of an autotransfusion device (ATD). There were 166 patients in the CDL group (56±15 years). LBAT patients were treated without (LBAT, n=58, 61±16 years) or with an ATD (LBATw, n=47, 62±15 years). Endpoints included change in HB between pre- and post-procedure measurements, the 7-day postprocedural nadir (low point), and adverse events (AE). ResultsThe mean HB change between pre- and post-procedure in the CDL, LBAT, and LBATw groups was -1.3±1.3 g/dl, -1.6±0.98 g/dl, and -1.1±0.9 g/dl, respectively (p=0.098). The mean HB change to the 7-day postprocedural nadir in the CDL, LBAT, and LBATw groups was -1.7±1.4 g/dl, -2.4±1.3 g/dl, and -1.8±1.3 g/dl, respectively (p=0.008). Minor hemorrhagic AE rate was 3.6% in CDL, 12.1% in LBAT, and 14.9% in LBATw (p=0.010). There was no significant difference in moderate (p=0.079) and major (p=0.529) hemorrhagic AE between the groups. There were no procedure related mortalities. ConclusionUse of LBAT without ATD resulted in a significant decrease in HB to the 7-day post-procedural nadir when compared to CDL or LBAT with ATD. This did not translate into significantly higher transfusion rates, moderate or major hemorrhagic events. Findings suggest that the decision between CDL and LBAT should not be based solely on the expected blood loss consideration.

Variations and Trends in 115 Years of Graded Daily Precipitation Records at Three Hydrometeorological Stations in Finland

This study investigated the variability and trends in 115 years (1909–2023) of daily precipitation observed at three hydrometeorological stations in southern (Kaisaniemi), central (Kajaani), and northern (Sodankylä) Finland. We also identified the most significant climate teleconnections influencing daily precipitation variability at these three stations during the period 1951–2023. The daily precipitation records were primarily classified into six grades, including very light (≤1 mm), light (1–≤5 mm), moderate (5–≤10 mm), heavy (10–≤15 mm), very heavy (15–≤20 mm), and extreme (>20 mm). On average, the most intense daily precipitation was determined at the Kaisaniemi station in southern Finland. At this station, however, very light and light precipitation showed the lowest frequency, but other graded daily precipitation events were the most frequent. At all three stations, the intensity of very light precipitation significantly declined during the past 115 years, while its frequency increased. The highest rates of such decreases and increases in the intensity and frequency of very light daily precipitation were found at the Sodankylä stations in northern Finland, respectively, but the lowest rates were at the Kaisaniemi station in the south. At the Kajaani station in central Finland, the intensity of light precipitation decreased, but very heavy precipitation intensified. At this station, however, the number of both moderate and heavy precipitation events increased over time. Finally, historical variations in both the intensity and frequency of graded daily precipitation events in Finland showed significant relationships with different climate teleconnections, particularly the Scandinavia (SCAND) and the North Atlantic Oscillation (NAO) patterns.

Urban Built Environment and Flood Ramifications: Evidence from Insurance Claims Data in Miami, Florida

This study examines the role of the urban built environment in mitigating or exacerbating flooding. By analyzing census tract-level insurance claims in Miami, we model such relationships during moderate and extreme flood events. Our findings indicate that lower population density, higher urban compactness, and proximity to coastal and riparian zones are linked to elevated flood insurance claims. The study also highlights the potential of nature-based solutions in alleviating flood impacts during extreme events. These insights provide crucial empirical evidence for urban planners and policymakers to adopt a systemic approach considering density, location, and nature-based solutions to foster climate-resilient cities.

Potential contribution of land cover change on flood events in the Senegal River basin

The increase in flood events observed in West African countries, and often in specific river basins, can be influenced by several factors, including anthropogenic land use and land-cover changes. However, the potential contribution of land cover changes to flood events still needs to be explored, especially in West Africa. Here, the fully coupled atmosphere-hydrology WRF-Hydro system, which comprises an atmospheric model and additionally incorporates the surface, subsurface, overland flow, and channel routing, is used to investigate the potential impact of a land cover change scenario on flood events in the Senegal River basin. The simulation was performed from 2010 to 2020, with a calibration period spanning from 2011 to 2012 and a validation period from 2013 to 2020. Several skill scores, including Nash-Sutcliffe Efficiency (NSE), BIAS, and Kling-Gupta Efficiency (KGE), were utilized to assess the calibration and validation performances. Additionally, two planetary boundary layer schemes (PBL5 and PBL7) were used to determine their associated uncertainty. Our results show that the best calibration results (NSE = 0.70; KGE = 0.83; PBIAS = −7% and BE = 0.67) in the Senegal River basin are obtained with PBL5 when the calibration is performed with a SLOPE parameter 0.03. A similar good performance was also obtained for the validation with NSE = 0.74, KGE = 0.84, and PBIAS = −8%. Likewise, our findings indicate that converting savanna to woody savannas can elevate water resources, with a 2% rise in precipitation and a 4% increase in runoff. This transition also correlates with an increase in moderate flood events (3500–4000 m3/s), a decrease in severe floods (4000–5000 m3/s), and their associated occurrence of extreme floods (>5000 m3/s) in the Senegal River basin.

Semaglutide Versus Other Glucagon-Like Peptide-1 Agonists for Weight Loss in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis.

Obesity places patients at higher risk for numerous problems, including prediabetes, type 2 diabetes mellitus (T2DM), hypertension, metabolic syndrome, cardiovascular disease, and nonalcoholic fatty liver disease. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are antidiabetic drugs that have a recognized effect on weight loss. This systematic review analyzed semaglutide against alternative GLP-1 agonists in facilitating weight loss and evaluated their associated adverse events (AEs) in diabetic patients. A systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using PubMed, Embase, and Cochrane Library for studies comparing semaglutide and other GLP-1 RAs for weight loss. A narrative synthesis and meta-analysis using SPSS program version 29 were performed to analyze the differences in weight loss between cohorts. Nine studies with 5,445 patients whose mean age was 60.01 years (55.5-70) and mean follow-up of 32.5 weeks (4-58.7) were included. The meta-analysis showed that semaglutide had a greater mean weight loss compared to liraglutide (-6.08, 95% confidence interval (Cl) = -8.40, -3.75) and dulaglutide (-2.85, 95% CI = -5.59, 0.11). Tirzepatide had a greater mean weight loss compared to semaglutide (-3.78, 95% CI = -5.52, -2.04). Common AEs included minor and moderate gastrointestinal events. In conclusion, GLP-1 RAs have shown efficacy in reducing body weight in T2DM patients. Semaglutide, liraglutide, dulaglutide, tirzepatide, and exenatide demonstrated mean weight loss reductions of 4.81 kg, 2.81 kg, 4.03 kg, 9.7 kg, and 1.9 kg, respectively, with high rates of minimal to moderate-severity AEs.Semaglutide demonstrated increased numerical weight loss compared to its comparators (dulaglutide, liraglutide, and exenatide). However, tirzepatide, a dual-agonist, produced greater weight loss compared to semaglutide. The paucity of comparative head-to-head trials prevents a definitive conclusion of the superiority of one GLP-1 RA over another.

A Tool Integrated into the Electronic Health Record to Guide Proper Decision-Making Regarding Peri-Endoscopic Anticoagulant Management: A Retrospective Cohort Study.

Background-Anticoagulants, such as vitamin-K antagonists (VKA) and direct oral anticoagulants (DOAC), are widely used among patients who undergo endoscopic procedures. To balance between bleeding and thromboembolic risks, careful decisions must be made about whether and for how long anticoagulants have to be stopped peri-endoscopically and if bridging is necessary. We created a tool in the electronic health records system (EHR) HIX (Microsoft) for invasive procedures to aid this decision-making. By selecting the anticoagulant indication or thrombo-embolic risk and the bleeding risk of the procedure, the tool automatically generates advice for periprocedural anticoagulant management. Objectives-This study assesses whether the tool is used properly peri-endoscopically. Secondly, it examines how many bleeding and thromboembolic events have occurred since the implementation of the tool. Methods-This retrospective study included all orders placed for endoscopies for patients using VKA or DOAC between 2018 and 2021. Results-In total, 986 endoscopies were included for analysis. In 89%, the tool was used correctly; the main error was selecting the wrong bleeding risk (7.5%). The cumulative incidence for moderate or severe bleeding events for DOAC and VKA was 2 (0.5%) and 0, respectively. The cumulative incidence of thromboembolic events for DOAC and VKA was 1 (0.2%) for each. Conclusions-This study evaluates the use of an EHR-integrated decision-making tool to aid peri-endoscopic anticoagulant management. By analysing the usage of the tool, we formulated several suggestions to improve the tool. Although this study is not a comparative one, we can conclude that the thromboembolic and major bleeding risks were low.

Flood risk assessment of a small river with limited available data

Flood risk modeling of small watercourses is challenging when only limited input data are available. Therefore, this study assessed the flood characteristics of a small river (Tarna River: entire watershed-C, upper-VS, middle-TMS, and lower section-TOS) from 1990 to 2019. The assessment focused on modeling, model calibration, and validation using feature event-based time-series data in data-scarce environments. We showed that since the 2000s, the number of high-water levels above 250 cm, and the frequency of three flood types had increased. Flood simulation results showed the largest flooded area in the TMS section, followed by the VS, and then the TOS. The outcomes from the VS, TMS, and TOS sections did not exhibit superior performance compared to the C area. Models performed well for larger flood events, with Kling Gupta Efficiency corresponding well to NRMSE and Nash-Sutcliffe efficiency metrics. Accordingly, flood events characterized by the longest duration and high-water levels yielded outstanding results across all areas, followed by moderate flood events with good accuracy. Normal water level events exhibited significant deviations from the reference across all sections. In summary, despite the event-based modeling challenges in data-limited environments, such models can still mitigate potential flood events and improve decision-making processes.

Enhanced erosion and silicate weathering of the West African craton during the late Cretaceous cooling evidenced by mineralogical and Hf[sbnd]Nd isotope proxies

The evolution of oceanic temperatures between the Turonian and the K/T boundary indicates a long-term cooling coincident with a decrease of atmospheric CO2 levels, yet the cause of climate cooling at that time still remains debated. In this study, we evaluated the possible implication of enhanced silicate weathering as a sink for atmospheric CO2 by applying paired NdHf isotope measurements to detrital clay records from the West African margin. The use of this novel proxy for chemical weathering intensity (ΔɛHf(t)clay) was complemented by additional mineralogical and major-trace element analyses in order to investigate the variability of mechanical erosion patterns and further explore potential linkages between tectonics, weathering and climate during the late Cretaceous.Our ΔɛHf(t)clay data suggest more intense silicate weathering on the West African Craton during the Santonian to the middle Campanian period, coincident with enhanced physical erosional inputs as inferred from higher Quartz/Clays and Feldspar/Clays ratios. This observation suggests that the shift towards intensified chemical weathering at that time was driven by enhanced mechanical erosion, possibly related to a moderate tectonic event on the West African craton. Evidence for increasing kaolinite contents and higher ΔɛHf(t)clay values during the Maastrichtian point towards more hydrolysing conditions, inducing either destabilization of older Mesozoic lateritic material or favouring the development of kaolinite-rich soils.Overall, this study was compared with several new data of chemical weathering evolution along the south Atlantic margins, adding new insights on tectonic-weathering-climate interactions during the late Cretaceous, suggesting a possible link between silicate weathering feedbacks and global cooling at that time.

Comparative analysis of the spatiotemporal patterns and trends of three types of summer heatwaves in China (1981–2020) using a biometeorological index

AbstractUnder global warming, heatwaves (HWs) are exerting increasing impacts on human life. In order to explore the thermal sensation of HWs under the combined influence of air temperature, humidity, radiation and wind speed, this study utilized the hourly Universal Thermal Climate Index (UTCI) data from the ECMWF Reanalysis v5 (ERA5) to define daytime, night‐time and compound HWs, and then comparatively analysed their occurrences in China during 1981–2020. Results revealed that daytime HWs affect the majority of regions in China with the exception of the Tibetan Plateau, while both night‐time and compound HWs mainly strike the Yangtze River Basin and the Guangdong–Guangxi region in southeastern China. Additionally, it is noteworthy that a substantial portion of regions experiencing night‐time HWs also encounter compound HWs. The frequency and intensity of all three types of HWs show increasing trends generally in regions where HWs occur. The spatial coverage of HWs grows at rates of 8.05%/10a, 2.11%/10a and 1.62%/10a for the daytime, night‐time and compound types, respectively. For each summer month, the spatial coverage of daytime HWs notably surpasses that of night‐time and compound HWs. Further classifying HWs with intensity, it is found that the spatial coverage of both moderate and severe HW events exhibits discernible rising trends across all three types of HWs. Furthermore, regions with higher HW frequencies are more likely to experience severe HWs as well as record‐breaking ones. Additionally, the spatial coverage of daytime, night‐time and compound record‐breaking HWs is expanding.

Statistical assessment of uncertainty and performance of multiple satellite-based precipitation products in capturing extreme precipitation events across Punjab Province, Pakistan

ABSTRACT The changing climate poses a significant danger to both environment and humans. Precipitation stands out as a critical factor for impacting hydrology, ecology, agriculture, and vegetation as well as crucial for maintaining the atmospheric equilibrium. This research examined four satellite-based precipitation products spanning from 2010 to 2018, focusing on assessing the uncertainty associated with these products in Punjab Province, Pakistan. Additionally, a comparative analysis of multi-satellite-derived precipitation data was conducted for the region. Various evaluation metrics, including CC, RMSE, Bias, rBias, and POD, were employed to gauge the performance of these datasets throughout the study area. Our research yielded the following findings: (1) datasets CHIRP and SM2RAIN exhibited the capability of capturing temporal changes observed in precipitation throughout the study area. (2) All satellite-derived datasets displayed superior performance on a monthly basis compared to daily timeframes. (3) On a seasonal scale, CHIRP and SM2RAIN exhibited superior precipitation detection capabilities compared to PERSIANN-CCS and PERSIANN-CDR. (4) CHIRP and SM2RAIN exhibited superior performance across all seasons when compared to PERSIANN-CCS and PERSIANN-CDR. Nonetheless, all products exhibited reasonably accurate detection of light to moderate precipitation events. This study serves to establish a foundation for effective monitoring, mitigation, and decision-making processes.

The Role of Talus Pile Mobility in Valley Widening Processes and the Development of Wide Bedrock Valleys, Buffalo River, AR

AbstractValley width is largely controlled by lithology and upstream drainage area, but little work has focused on identifying the processes through which valleys widen. Bedrock valleys widen by first laterally eroding bedrock valley walls, followed by the collapse of overlying bedrock material that must then be transported away from the valley wall before the valley can continue widening. We hypothesize that talus piles that cannot be transported by the river protect the valley wall and slow valley widening, while talus piles that are rapidly transported allow for uninterrupted valley widening. We used field measurements from 40 locations in both wide and narrow valleys along the Buffalo River, AR to test this hypothesis. Our data show that wide valleys tend to have fewer talus piles and smaller talus grain sizes, whereas talus in narrow valleys is larger in size and more continuous along valley walls. We calculated potential talus block entrainment at each site location and found that talus blocks in wide valleys are potentially entrained and moved away from valley walls during moderate and large flood events, whereas talus blocks in narrow valleys are very rarely moved. Our results show that the potential transport of talus piles protecting bedrock valley walls from widening is controlled by the block size of collapsed bedrock wall material relative to stream competency. Our results also suggest that persistence versus mobility of collapsed talus piles is an important process in the development of wide bedrock valleys.

A rapid analysis of aftershock processes after a moderate magnitude earthquake with ML methods

SUMMARY Moderate magnitude earthquakes and seismic sequences frequently develop on fault systems, but whether they are linked to future major ruptures is always ambiguous. In this study, we investigated a seismic sequence that has developed within a portion of the stretching region of the Apennines in Italy where moderate to large earthquakes are likely to occur. We captured a total of 2039 aftershocks of the 2023 September 18, Mw 4.9 earthquake occurred during the first week, by using machine-learning (ML) based algorithms. Aftershocks align on two 5–7 km long parallel faults, from a length that exceeds what is expected from the main shock magnitude. The segments are ramping at about 6 km depth on closely spaced N100 striking 70 N dipping planes, at a distance of some kilometres from the main shock hypocentre. Our results indicate that even moderate magnitude events trigger seismicity on a spread set of fault segments around the main shock hypocentre, revealing processes of interaction within the crustal layer. The possibility that larger earthquakes develop during seismicity spread is favoured by pore pressure diffusion, in relation with the closeness to criticality of fault segments. Based on the very rapid activation of seismicity on the entire system and a back-front signal from the hypocentre of the main event, we infer that fluid pressure, initially high within the crustal layer, rapidly dropped after the main shock. Our study reinforces the importance of timely extracting information on fault geometry and seismicity distribution on faults. ML-based methods represent a viable tool for semi-real-time application, yielding constraints on short-time forecasts.

Trajectory, fate, and magnitude of continental microplastic loads to the inner shelf: A case study of the world's largest coastal shallow lagoon

The Patos Lagoon estuary is a highly significant ecosystem where freshwater from a vast and densely populated area continuously flows into the Atlantic Ocean by coastal plumes, exporting not only freshwater but also sediment, nutrients, plastics, and other contaminants. In this work, numerical modeling tools together with field data were used to assess for the first time the capacity of the coastal plume to export microplastics (MPs) to the inner shelf under different hydrodynamic conditions. Two field surveys were conducted during plume events to quantify MP concentrations and validate the model approach. A bottom-up approach was employed to estimate the potential MP export from the estuary's domain to the Atlantic Ocean. MP concentration in surface plume waters ranged from 0.20 items m−3 to 1.37 items m−3, confirmed by FTIR as synthetic polymers in a 90 %, being Polypropylene (PP) and Polyethylene (PE) the most abundant in a 73 %. The accumulation pattern was observed on the plume's frontal system, consistent with simulation results. The estimated average MP potential export rate attained 9.0 million items day−1 during moderate plume events and 47.5 million items day−1 during high discharge plume events. Strong discharge events, coupled with intense northeast winds, facilitated rapid southwestward export of MPs. Conversely, moderate to weak discharge events retained MPs closer to the estuary's mouth, enabling either longer trajectories or earlier deposition. Significant MP accumulation hotspots were identified in the gyre between the jetties and Cassino beach, as well as in the saline front within the plume boundaries. These accumulation zones may function as reservoirs for MP particles, potentially posing threats to local ecosystems. Understanding these dynamics is crucial for ongoing monitoring efforts to assess potential harmful interactions over time.