To assess coastal hazard where Coastal boulder deposits (CBDs) are found, it is crucial to constrain the forces governing their emplacement: from either storms/tropical cyclones or tsunamis. Here we focus on the CBDs on the island of Cuba and the extreme climatic events responsible for their formation. Four sites are being studied to identify the CBDs produced during known hurricanes over the last fifty years.The selected CBDs are located on a low-lying coral reef terrace on the Cuban shore, emplaced by the Cuban hurricane of 1935, Lili hurricane of 1996 and Matthew hurricane of 2016. These meteorological events associated with reported geomorphological objects are analyzed to quantify the hydrodynamic parameters of such extreme events (maximum orbital velocity). Furthermore, the quantification of CBDs volume by stereophotogrammetry (using Agisoft Metashape Professional version 1.7.2) and CBDs density by water immersion method on samples allow us to use deterministic and theoretical approaches ( hydrodynamics equations of Nandasena et al., 2013, 2022 ) to assess the assumed associated hydrodynamic parameters (minimum flow velocity) responsible for the dislocation of the coral reef terraces and transport of the resulted boulders. Finally, we compare these velocities with ones calculated from the meteorological events to discuss the reliability of these approaches to determine the climatic or tsunamigenic origin of the past extreme waves from geomorphological analyses of CBDs.
Allochthonous cave sediments contain important paleontological and archaeological records as well as indicators of recent ecological processes. Correct interpretation of these records requires knowledge about the sediment sources and deposition processes, in particular the interrelation of vertical and lateral sediment transport. Compared to platform karst, knowledge about tropical mountainous karstic geosystems is quite limited. To trace the origin and transportation pathways of sediments, we investigated Atl Cave in the Sierra Zongolica Mountain range, Veracruz, Mexico. Field exploration and mapping have shown that the cave presents two horizontal stages representing phreatic conduits and ancient stability stages and is an epigenetic cave with a point recharge zone at the entrance, which is fed by a stream. A comparative study of the surface soil profiles and the diamicton facies of the cave floor deposits included field morphological description, micromorphological observations, grainsize analysis, colorimetry, bulk chemical composition via XRF, and clay mineral identification by XRD. The results demonstrate that the cave deposits have more similarities with the young alluvial and colluvial soils near the entrance than with mature Terra Rossa developed over the limestone formation that hosts the cave. This proves the predominant role of the lateral alluvial transport by high energy events in the formation of the cave diamicton with very restricted contribution of the vertical erosion of Terra Rossa. The main source rock for alluvial and colluvial materials transported to the cave are siliciclastic sediments of the Necoxtla formation, whereas Terra Rossa soils were formed from tephra of the Orizaba volcano. High CIA values, high clay content with a predominance of kaolinite, point to greater weathering of Terra Rossa in comparison with other studied surface and underground materials.
Introduction and Objectives: Covert hepatic encephalopathy (CHE) is a common complication in patients with compensated cirrhosis, associated with subtle cognitive impairment and a worse prognosis. The EncephalApp Stroop is a digital tool that facilitates its identification.To evaluate the diagnostic capacity of the EncephalApp Stroop to identify CHE in patients with compensated cirrhosis Materials and Methods: A diagnostic evaluation study was conducted in patients with compensated cirrhosis treated at the Institute of Gastroenterology in Havana, Cuba, between March 2023 and December 2024. All participants completed the EncephalApp Stroop and the Psychometric Hepatic Encephalopathy Score (PHES). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined. The discriminatory capacity of the test was assessed using ROC curve analysis, considering a cutoff point of >190 seconds in the “on” time metric plus “off” time, and the PHES result as the gold standard. Results: Seventy patients of both sexes were included, with a predominance of viral etiology (74.3%). The prevalence of EHE was 38.6%. The EncephalApp Stroop showed a sensitivity of 95.2% (95% CI: 77.3% to 99.2%) and specificity of 85.7% (95% CI: 73.3% to 92.9%), PPV of 74.1% (95% CI: 55.3% to 86.8%) and NPV of 97.7% (95% CI: 87.9% to 99.6%) for the detection of HSE, with an area under the ROC curve of 0.905 (95% CI: 0.826-0.984). Conclusions: The EncephalApp Stroop is a valid, accessible, and efficient diagnostic test for identifying EHE in compensated cirrhosis, with high performance compared to PHES as the gold standard. Its implementation can optimize early detection and clinical management.
Introduction and Objectives: Despite existing surveillance methods, the diagnosis of hepatocellular carcinoma (HCC) in at-risk populations often occurs in advanced stages of the disease and carries a worse prognosis. AFP and PIVKA-II are two of the tumor biomarkers that have received the most attention for monitoring at-risk patients.To determine the value of the isolated and combined detection of PIVKA-II and alpha-fetoprotein in the diagnosis of hepatocellular carcinoma in at-risk population. Materials and Methods: A cross-sectional descriptive study with an analytical component was conducted across three tertiary centers between July 2024 and April 2025. A total of 291 patients at risk for HCC were included; 11 were diagnosed with HCC. Independent variables assessed included age, sex, serum alpha-fetoprotein (AFP) and PIVKA-II levels. HCC diagnosis served as the dependent variable. The ROC curve was calculated to determinate the diagnostic usefulness of the isolated AFP, PIVKA-II and the combination of both biomarkers. Results: The mean age was 62 ± 10.3 years, with a predominance of patients aged ≤62. The most common risk group was liver cirrhosis (91.1%), with a slight predominance of females. The area under the curve was similar for AFP and PIVKA-II, confirming the good discriminatory power of both tests, but the combination of these tests was discretely greater than the biomarkers separately. Conclusions: The diagnostic performance of both biomarkers (AFP and PIVKA-II) was similar during the evaluation of patients at risk of developing HCC, but the combination of both showed better discriminatory power between patients affected or not by this neoplasia.
Introduction and Objectives: Hepatocellular carcinoma (HCC) is a fearsome neoplasia with patients at well-identified risk who require surveillance.To identify variables that are influential in the diagnosis of hepatocellular carcinoma in at-risk individuals. Materials and Methods: A cross-sectional descriptive study with an analytical component was conducted across three tertiary care centers between July 2024 and April 2025. A total of 291 patients at risk for HCC were included; 11 were diagnosed with HCC. Independent variables assessed included age, sex, risk group, cirrhosis etiology, serum alpha-fetoprotein (AFP), and PIVKA-II levels. HCC diagnosis served as the dependent variable. Categorical variables were summarized as frequencies and percentages; continuous variables as means and standard deviations (SD). Univariate and multivariate logistic regression analyses were performed to identify factors significantly associated with HCC. Results: The mean age was 62 ± 10.3 years, with a predominance of patients aged ≤62. The most common risk group was liver cirrhosis (91.1%), with a slight predominance of females. In univariate analysis, liver cirrhosis, AFP ≥ 20 ng/mL, and PIVKA-II ≥ 28.4 ng/mL were significantly associated with HCC diagnosis. Multivariate analysis showed that these same variables were statistically significantly associated with the diagnosis of hepatocellular carcinoma. Conclusions: In at-risk patients, the presence of cirrhosis, elevated AFP (≥ 20 ng/mL) and elevated PIVKA-II (≥ 28.4 ng/mL) are strongly associated with the diagnosis of hepatocellular carcinoma.
