Search Results (680)

This study presents a numerical and experimental evaluation of axial load transfer mechanisms in deep foundations constructed in stratified cohesive soils in İzmir, Türkiye. A full-scale bi-directional static load test equipped with strain gauges was conducted on a barrette pile to investigate depth-dependent mobilization of shaft resistance. A finite element model was developed and calibrated using field-observed load–settlement and strain data to replicate the pile–soil interaction and deformation behavior. The analysis revealed a shaft-dominated load transfer behavior, with progressive mobilization concentrated in intermediate-depth cohesive layers. Sensitivity analysis identified the undrained stiffness (E_u) as the most influential parameter governing pile settlement. A strong polynomial correlation was established between calibrated E_u values and SPT N₆₀, offering a practical tool for preliminary design. Additionally, strain energy distribution was evaluated as a supplementary metric, enhancing the interpretation of mobilization zones beyond conventional stress-based methods. The integrated approach provides valuable insights for performance-based foundation design in layered cohesive ground, supporting the development of site-calibrated numerical models informed by full-scale testing data. Full article

In healthy humans, insulin at physiological concentrations exerts acute vasodilatory actions on both resistance and terminal arterioles, leading, respectively, to increased total blood flow and the microvascular network volume being perfused. The process of increasing capillary network volume is frequently referred to as “capillary recruitment”. Together these two vascular actions of insulin enhance the delivery of oxygen, nutrients, and insulin itself to tissues. Both processes are diminished by insulin resistance. Here we examined interactions between insulin’s acute (within 2 h) actions on blood pressure (both central and peripheral) and on capillary recruitment in healthy controls and in four distinct groups of people with heightened cardio-metabolic disease (CMD) risk: individuals with obesity, metabolic syndrome, and type 1 or type 2 diabetes. Insulin increased microvascular blood volume (MBV) more effectively in controls than in each of the four CMD risk groups (p < 0.001). Conversely, insulin lowered both central and peripheral systolic pressure (p < 0.05 or less) in each of the CMD risk groups but not in the controls. The insulin-induced blood pressure decrements were greater in the metabolic syndrome, type 2 diabetes, and obesity groups (p < 0.05 or less) than in the controls. The greater blood pressure declines likely reflect decreased sympathetic baroreceptor reflex tone. These effects on blood pressure combined with the diminished dilation of terminal arterioles due to microvascular insulin resistance in the CMD risk subjects led to decreased distal microvascular perfusion as evidenced by changes in MBV. These findings highlight the complex interplay between insulin’s actions on resistance and terminal arterioles in individuals with a high CMD risk, underscoring the importance of addressing microvascular dysfunction in these conditions. Full article

In the United States, adolescents and young adults between the ages of 16 and 23 have high rates of serogroup B meningococcal infections due to an elevated risk for those attending college. This review examines meningococcal vaccination requirements and recommendations for college students in the United States, with a focus on state-level mandates. National stakeholder resources, state legislatures, and official state Department of Health and Department of Education websites were analyzed for each state and Washington, DC. Overall, 26 states mandate MenACWY vaccination for college entry, whereas only 2 have specific requirements for MenB vaccination. Among the six states with the largest state university campus enrollments, half mandate MenACWY vaccination for college students, whereas none mandate MenB. By region, the Northeast had the highest percentage of states with a MenACWY requirement for college entry (77.8%) followed by the South (64.7%), Midwest (41.7%), and West (23.1%). Further research is needed to elucidate the relationship between state mandates and coverage to aid in optimizing meningococcal vaccination for college students. Full article

In the U.S. public school system, White middle-class female teacher workforces have dominantly served an increasing number of students of color. While the racial interplay between teachers and students has offered insightful implications for continuing disparities in student discipline, little research has been done to link the racial match of the teaching force to their served communities. This study examines how the ethnoracial congruence between teachers and populations in their school district moderates racial gaps in in-school suspension rates between White and non-White students in Tennessee. The research demonstrates that when teachers serve communities of the same race, their schools are less likely to show a substantial gap in in-school suspensions between White students and students of color. Full article

Barrett’s esophagus (BE), a metaplastic transformation of an esophageal squamous epithelium into an intestinal-type columnar epithelium, is the primary precursor to esophageal adenocarcinoma (EAC). Traditional management strategies have relied heavily on selective screening, tailored surveillance intervals, and early dysplasia detection and treatment algorithms. However, the heterogeneity in progression risk among BE patients necessitates a more nuanced, personalized approach involving precision care, tailoring decisions to individual patient characteristics, promises to enhance outcomes in BE through more targeted screening, personalized surveillance intervals, and risk-based therapeutic strategies. This review explores the current landscape and emerging trends in precision medicine for Barrett’s esophagus, highlighting genomic markers, digital pathology, and AI-driven models as tools to transform how we approach this complex disease and prevent progression to EAC. Full article

Spinfoam theories propose a well-defined path-integral formulation for quantum gravity, and it is hoped that they will provide the dynamics of loop quantum gravity. However, it is computationally hard to calculate spinfoam amplitudes. The well-studied Euclidean Barrett–Crane model provides an excellent setting for testing analytical and numerical tools to probe spinfoam models. We explore a data-driven approach to accelerating spinfoam computations by showing that the vertex amplitude is an object that can be learned from data using deep learning. We divide the learning process into a classification and a regression task: Two networks are independently engineered to decide whether the amplitude is zero or not and to predict the precise numerical value, respectively. The trained networks are tested with several accuracy measures. The classifier in particular demonstrates robust generalisation far outside the training domain, while the regressor demonstrates high predictive accuracy in the domain it is trained on. We discuss limitations, possible improvements, and implications for future work. Full article

Mangroves form the dominant coastal plant community of low-energy tropical intertidal habitats and provide critical ecosystem services to humans and the environment. However, more frequent and increasingly powerful hurricanes and storm surges are creating additional pressure on the natural resilience of these threatened coastal ecosystems. Advances in remote sensing techniques and approaches are critical to providing robust quantitative monitoring of post-storm mangrove forest recovery to better prioritize the often-limited resources available for the restoration of these storm-damaged habitats. Here, we build on previously utilized spatial and temporal ranges of European Space Agency (ESA) Sentinel satellite imagery to monitor and map the recovery of the mangrove forests of the British Virgin Islands (BVI) since the occurrence of back-to-back category 5 hurricanes, Irma and Maria, on September 6 and 19 of 2017, respectively. Pre- to post-storm changes in coastal mangrove forest health were assessed annually using the normalized difference vegetation index (NDVI) and moisture stress index (MSI) from 2016 to 2023 using Google Earth Engine. Results reveal a steady trajectory towards forest health recovery on many of the Territory’s islands since the storms’ impacts in 2017. However, some mangrove patches are slower to recover, such as those on the islands of Virgin Gorda and Jost Van Dyke, and, in some cases, have shown a continued decline (e.g., Prickly Pear Island). Our work also uses a linear ANCOVA model to assess a variety of geospatial, environmental, and anthropogenic drivers for mangrove recovery as a function of NDVI pre-storm and post-storm conditions. The model suggests that roughly 58% of the variability in the 7-year difference (2016 to 2023) in NDVI may be related by a positive linear relationship with the variable of population within 0.5 km and a negative linear relationship with the variables of northwest aspect vs. southwest aspect, island size, temperature, and slope. Full article

Underground hydrogen storage (UHS) in carbonate and siliceous formations presents a promising solution for managing intermittent renewable energy. However, experimental data on hydrogen–rock interactions under representative subsurface conditions remain limited. This study systematically investigates mineralogical and petrophysical alterations in dolomite, calcite-rich limestone, and quartz-dominant siliceous cores subjected to high-pressure hydrogen (100 bar, 70 °C, 100 days). Distinct from prior research focused on diffraction peak shifts, our analysis prioritizes quantitative changes in mineral concentration (%) as a direct metric of reactivity and structural integrity, offering more robust insights into long-term storage viability. Hydrogen exposure induced significant dolomite dissolution, evidenced by reduced crystalline content (from 12.20% to 10.53%) and accessory phase loss, indicative of partial decarbonation and ankerite-like formation via cation exchange. Conversely, limestone exhibited more pronounced carbonate reduction (vaterite from 6.05% to 4.82% and calcite from 2.35% to 0%), signaling high reactivity, mineral instability, and potential pore clogging from secondary precipitation. In contrast, quartz-rich cores demonstrated exceptional chemical inertness, maintaining consistent mineral concentrations. Furthermore, Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore distribution analyses revealed enhanced porosity and permeability in dolomite (pore volume increased >10×), while calcite showed declining properties and quartz showed negligible changes. SEM-EDS supported these trends, detailing Fe migration and textural evolution in dolomite, microfissuring in calcite, and structural preservation in quartz. This research establishes a unique experimental framework for understanding hydrogen–rock interactions under reservoir-relevant conditions. It provides crucial insights into mineralogical compatibility and structural resilience for UHS, identifying dolomite as a highly promising host and highlighting calcitic rocks’ limitations for long-term hydrogen containment. Full article

Background: Understanding the determinants of children’s outdoor play is an important element for child development and broader public health outcomes. There is growing evidence that children’s opportunities for play, particularly outdoor risky play, are diminishing. Parents are concerned with keeping their child safe while affording them independence to play. This study explored parents’ attitudes to risky play and practices around children’s independent mobility in Ireland with the aim of informing public health strategies promoting healthy childhood environments. Methods: An online survey comprising validated scales and standardised questions was completed by a nationally represented sample of 376 parents of children up to 16 years. Data was analysed via descriptive statistics, chi-square tests, and regression analysis. Results: A total of 376 participants accessed the survey, of which 349 completed it. A total of 84% of participants were female. A total of 74% agreed that children need regular exposure to actual risk to develop risk management skills, and 71% trusted their children to play safely. Chi-square tests reveal significant associations between outdoor play in the rain and school travel (p < 0.01), and appropriate age to begin activities at home and in educational settings (p < 0.05). A moderate association was found between the method of school travel and children’s permission to play in the rain (Cramer’s V = 0.51). Respondents considered supervision to be a necessity to ensure their children’s safety. Overall, the results indicate that parents were risk-averse in three of the six categories of risky play, namely, play near dangerous elements, play with adult tools, and out-of-sight play. Conclusions: This study presents a descriptive analysis of findings from the Ireland State of Play Survey. Findings indicate that although parents recognise the benefits of risky play, there is some contradiction between parental attitudes and actual practices, with a lack of willingness or confidence in permitting their children to participate in all such activities. Full article

Depensation (or an Allee effect) has recently been detected in stock–recruitment relationships (SRRs) in four Atlantic herring stocks and one Atlantic cod stock using a Bayesian statistical approach. In the present study, we define the Allee effect threshold (B_AET) for these five stocks and propose B_AET as a candidate limit reference point (LRP). We compare B_AET to traditional LRPs based on proportions of equilibrium unfished biomass (B₀) and biomass at maximum sustainable yield (B_MSY) assuming a Beverton–Holt or Ricker SRR with and without depensation, and to the change point from a hockey stick SRR (B_CP). The B_AET for the case studies exceeded 0.2 B₀ and 0.4 B_MSY for three of the case study stocks and exceedances of 0.2 B₀ were more common when the Ricker form of the SRR was assumed. The B_AET estimates for all case studies were less than B_CP. When there is depensation in the SRR, multiple equilibrium states can exist when fishing at a fixed fishing mortality rate (F) because the equilibrium recruits-per-spawner line at a given F can intersect the SRR more than once. The equilibrium biomass is determined by whether there is excess recruitment at the initial projected stock biomass. Estimates of equilibrium F_MSY in the case studies were generally higher for SRRs that included the depensation parameter; however, the long-term F that would lead the stock to crash (F_crash) in the depensation SRRs was often about half the F_crash for SRRs without depensation. When warranted, this study recommends exploration of candidate LRPs from depensatory SRRs, especially if Allee effect thresholds exceed commonly used limits, and simulation testing of management strategies for robustness to depensatory effects. Full article

Background and Aims: Gastroesophageal reflux disease (GERD) is the most common esophageal disorder worldwide and a progressive condition leading to Barrett’s esophagus and adenocarcinoma. Continuous medical therapy with proton pump inhibitors fails to restore the antireflux barrier and is unable to relieve symptoms in up to 40% of patients. A tailored and standardized antireflux surgical procedure may increase cure rates and meet patient expectations. Methods and Results: Antireflux surgery aims to reestablish the natural antireflux barrier, which includes the diaphragmatic crura, the lower esophageal sphincter (LES), and the angle of His along with the gastroesophageal flap valve. For decades, the Nissen total fundoplication has been the primary procedure and remains the gold standard for surgical treatment. Alternatives such as Toupet partial fundoplication, Dor partial fundoplication, and the magnetic sphincter augmentation (LINX™) procedure have been developed to mitigate side effects like dysphagia, gas-bloat syndrome, and the inability to belch or vomit. Recent clinical findings regarding a novel procedure, RefluxStop™, indicate that restoring the gastroesophageal flap valve, in conjunction with anterior fundoplication and a silicone device for stabilizing the LES beneath the diaphragm, can achieve lasting reflux control and enhance patient-reported outcomes. Conclusions: The planning of healthcare services and actionable strategies to improve equity and quality of treatment is critical to address the global burden of GERD. Modern laparoscopic surgery for GERD is safe and effective and should be performed in centers offering a complete diagnostic pathway and specific surgical techniques tailored to the individual GERD phenotype. Shared decision-making between the surgeon and the patient is essential for the choice of operation. A personalized approach can offer clinical benefits over total fundoplication and improve patient-reported outcomes. Full article

Evidence based practice enhances healthcare delivery and prevents unsafe procedures. While competency based assessments of resident cataract surgery are standard, evidence based analysis of refractive outcomes remains underutilized in educational curricula. This retrospective single center study evaluated refractive outcomes from 21 novice ophthalmology resident surgeons. Three independent groups were compared based on formal constant optimization for intraocular lens (IOL) calculation: non-optimized Haigis (n = 216), a0-optimized (n = 94), and a0/a1/a2-optimized (n = 121). All surgeries were supervised by a single attending surgeon. Mean absolute error (MAE) and the percentage of eyes within ±0.25 D and ±0.50 D of predicted spherical equivalent (SEQ) were calculated. Also, systematic bias in effective lens position (ELP) was analyzed to update manufacturer IOL constants. MAE improved from 0.44 D (non-optimized) to 0.35 D (a0-optimized p = 0.009) and 0.19 D (a0/a1/a2-optimized p < 0.001). The percentage within ±0.50 D increased from 65.7% to 74.4% to 95.0%, respectively. With ELP bias correction, updated A constant and ACD were 119.266 and 5.755 mm. a0/a1/a2-optimized outcomes were comparable to ELP bias correction for the Barrett UII, Kane, and Hill-RBF formulas. Evidence based optimization of IOL constants significantly enhances novice resident surgical outcomes, achieving parity with prediction models. A formal curriculum on IOL calculation and optimization is warranted. Full article

The Morehouse School of Medicine Prevention Research Center (MSM-PRC) conducted a Community Health Needs and Assets Assessment (CHNAA) survey using a Community-Based Participatory Research (CBPR) approach. In this article, we will demonstrate the application of CBPR in informing research agenda and implementation strategies. We will discuss the practical considerations and potential benefits of engaging the community in data collection, interpretation, and utilization to address community health challenges. Emphasizing collaboration, co-learning, and respect, and guided by the CBPR principles, CHNAA ensured that community voices led to the identification and integration of the research priorities. Overseen by the Community Coalition Board (CCB) and its Data Monitoring and Evaluation (DME) Committee, the survey featured closed- and open-ended questions addressing social determinants of health. Out of 1000 targeted participants, 754 provided valid responses, with a 75% response rate. Most respondents were female and represented a racially diverse group. Descriptive statistics and thematic analysis revealed that key health concerns were diabetes, COVID-19, mental health, and high blood pressure. Barriers to care included lack of food access, affordable housing, and limited mental health services. The findings led to five public health initiatives launched between 2023 and 2024 demonstrating the CBPR model’s effectiveness in aligning community needs with actionable solutions. Full article

Gastroesophageal reflux disease (GERD) is associated with inflammatory and neoplastic changes in the esophageal epithelium. Despite widespread PPI use, esophageal adenocarcinoma (EAC) incidence continues to rise, implicating non-acidic reflux components such as pepsin in disease progression. We performed transcriptomic profiling to assess pepsin-induced changes and the protective effect of amprenavir in vitro. Het-1A (normal) and BAR-T (Barrett’s) cells (n = 3) were treated at pH 7.0 with pepsin and/or 10 μM amprenavir for 1 h. RNA-seq identified DEGs (FDR ≤ 0.05, |log₂FC| ≥ 0.375), and Ingenuity Pathway Analysis revealed enriched pathways. Pepsin exposure altered mitochondrial function, oxidative phosphorylation, epithelial integrity, signaling, and inflammatory pathways in both cell lines. Amprenavir attenuated these transcriptomic perturbations, preserving mitochondrial and stress-response pathways. Notably, BAR-T cells exhibited heightened activation of wound-healing and epithelial repair pathways, whereas Het-1A cells showed greater mitochondrial and systemic stress pathway alterations. Pepsin drives transcriptomic dysregulation in esophageal epithelial cells under non-acidic conditions, and amprenavir shows potential to counteract peptic injury. Further studies are needed to validate these findings and explore amprenavir’s therapeutic utility in GERD management and EAC prevention. Full article

Obesity is a global health crisis with profound implications for cancer risk, particularly within the gastrointestinal (GI) tract. Mounting evidence demonstrates that excess adiposity contributes to the initiation, progression, and poor outcomes of GI malignancies through a constellation of interrelated mechanisms. This review comprehensively examines the biologic pathways linking obesity to cancers of the esophagus, stomach, colon, liver, pancreas, and gallbladder. Chronic low-grade inflammation, driven by adipose tissue-derived cytokines and immune cell infiltration, plays a central role in tumorigenesis via the activation of NF-κB, STAT3, and other pro-oncogenic signaling cascades. Hyperinsulinemia and insulin resistance increase mitogenic IGF-1 signaling, while dysregulated adipokines, particularly elevated leptin and reduced adiponectin, promote cellular proliferation and impair tumor suppression. Dysbiosis of the gut microbiome and alterations in bile acid metabolism generate carcinogenic metabolites that contribute to DNA damage and immune evasion. Additionally, obesity-induced tissue hypoxia fosters tumor growth through HIF-1α-mediated pathways. We further highlight organ-specific associations, such as visceral adiposity’s role in Barrett’s esophagus and hepatocellular carcinoma emerging from metabolic dysfunction-associated steatotic liver disease (MASLD). Importantly, emerging data suggest that weight loss, achieved via lifestyle, pharmacologic, or surgical interventions, may mitigate these carcinogenic pathways and improve tumor biology. As obesity prevalence continues to rise globally, elucidating its mechanistic ties to GI malignancies is essential for risk stratification, prevention strategies, and personalized care. By integrating epidemiologic and molecular insights, this review underscores the need for multidisciplinary approaches to curb the oncogenic burden of obesity and improve outcomes in GI oncology. Full article