Search Results (736)

Chicoric and chlorogenic acids (CRA and CGA), two caffeic acid derivatives found in a large variety of plants, particularly in Asteraceae, are known to modulate glucose-6-phosphatase (G6Pase) in hepatic and muscle cells. The aim of the present study is to use CRA/CGA to explore the modulation role and molecular mechanism of endocrine pancreatic beta-cells’ insulin secretion. The G6Pase enzyme activity influenced by caffeic and derivatives alone or in combination was assessed on microsomal fractions of INS1-beta-cells and hepatocytes. Overall, our results show inverse effects of CGA/CRA, allowing us to investigate the G6Pase activity modulation under low and high glucose concentrations. Our data strongly suggests the existence of two putative forms of the G6Pase enzyme. Based on these observations, we formulate the hypothesis of an adaptative bi-conformational model of G6Pase enzyme activity modulation depending on the level of the beta-cell glucose exposure. Full article

As the Pamir Plateau is known as the “Water Tower of Central Asia”, accurate precipitation dataset is essential for the study of climate and hydrology in this region. Based on the monthly precipitation observations from 268 meteorological stations in the Eastern Pamir Plateau (EPP) during the April-to-September warm season of 2010–2024, this paper comprehensively evaluates the applicability of eight multi-source precipitation datasets in complex terrains by using statistical indicators, constructs a skill-weighted ensemble mean dataset (Skill-Ens), and analyzes the elevation-dependent characteristics of precipitation in the EPP. The research findings are as follows: (1) The warm-season precipitation in the EPP shows a significant elevation-dependent feature, with the maximum precipitation altitude (MPA) in the range of 2400–2800 m. Precipitation is reduced above this elevation range, but a second MPA may appear in the glacier area above 4000 m. (2) Among the studied eight datasets, the first-generation Chinese Global Land-surface Reanalysis (CRA40/Land) performs the best overall. A long-term (1979–2020) high-resolution (1/30°) precipitation dataset for the Third Pole region (TPHiPr) can most accurately capture the elevation-dependent characteristics of precipitation, while the satellite datasets are relatively poor in this respect. (3) The skill-weighted ensemble mean dataset (Skill-Ens) constructed in this study can significantly improve precipitation estimation (DISO = 0.35), especially in the MPA region, and can accurately depict the elevation-dependent characteristics of precipitation as well (CC = 0.92). In a word, this paper provides the applicable options for precipitation data in complex terrain areas. With the Skill-Ens, the limitation of the individual dataset has been compensated for, which is of significant application value in improving the accuracy of hydrological simulations in high-elevation mountainous areas. Full article

The physiological and gill health responses of juvenile spotted rose snapper (Lutjanus guttatus) were evaluated at four salinities—8, 16, 24, and 32‰—over a 70-day period. Fish reared at 8‰ exhibited the highest final body weight (126.8 ± 2.6 g), which was significantly higher than their congeners kept at 24‰ (116.0 ± 2.3 g) and 32‰ (116.0 ± 2.3 g). This superior growth at 8‰ coincides with the complete absence of parasitic monogenean infestations. In contrast, parasite prevalence increased with salinity, reaching 87.5% at 24‰, and was associated with gill pathologies like hyperplasia. Plasma osmolality and chloride levels decreased at lower salinities, while sodium and potassium levels showed a compensatory increase. Plasma cortisol and glucose levels remained stable across all treatments, indicating an absence of chronic stress. These findings suggest that the optimal rearing salinity for juvenile L. guttatus is near 8‰. The enhanced growth at this salinity appears to be the result of a net energy gain, stemming from a trade-off between the minor cost of osmoregulation in a hypo-osmotic environment and the major energetic benefit of avoiding parasitic disease. Full article

The Yangtze River Basin (YRB) is highly vulnerable to both floods and droughts, with precipitation playing a key role in driving these hydrological extremes. Understanding and reducing uncertainty in precipitation estimates is therefore crucial for effective water management and hazard mitigation. The study evaluated the error characteristics of daily precipitation estimates from three datasets (CRA40, IMERG, and SM2RAIN) using the triple collocation (TC) approach. A least-squares merging framework was then applied to integrate these datasets and generate merged precipitation estimates with improved accuracy and reduced uncertainty over the YRB. Results showed that all examined datasets exhibited higher fractional root-mean-squared error (fRMSE) in the source region of the Yangtze River, indicating a greater influence of random errors and reduced sensitivity to precipitation changes in this area. Among the datasets, SM2RAIN exhibited the weakest agreement with ground-based measurements, while IMERG performed best in capturing extreme precipitation events. CRA40 and the TC-based merged precipitation estimates exhibited overall higher accuracy, with a station-average correlation coefficient of approximately 0.71. Despite comparable accuracy, the merged precipitation data is relatively more robust than CRA40, with a lower average error standard deviation of 2.07 mm. Full article

With the increasing number of existing buildings, the implementation of durability-preserving repair procedures is becoming increasingly important. The chemical re-alkalization (CRA) enables the protection of reinforced concrete structures exposed to carbonation by maintaining or restoring the alkalinity in the concrete through the application of an alkaline mortar, such as hybrid alkali-activated binders (HAABs). However, the process of CRA is still insufficiently understood, which means that the requirements for the repair mortars can only be roughly formulated. This paper therefore investigates the process of CRA using laser-induced breakdown spectroscopy (LIBS). Based on the quantitative results of potassium transport in the composite system, a time-dependent attenuation factor can be determined that allows for the adaptation of Fick’s second law of diffusion previously used to predict CRA. The attenuation factor provides further insight into the course of potassium transport, which, based on the results, never follows an ideal diffusion process. Adjusting the diffusion law allows for an improved prediction of the maximum achievable re-alkalization depth depending on the repair mortar, where a potassium content of, e.g., 2.3 wt% leads to a complete re-alkalization of 16 mm. The present study demonstrates the potential of LIBS to quantitatively represent CRA for the first time thus providing new insights into potassium transport and the dynamics of the process. Full article

The growing interest in sustainable materials has encouraged the valorization of agro-industrial byproducts for pharmaceutical, nutraceutical, and food applications. This study evaluated yellow pitaya peel powder, obtained via convective and refractance window drying, as a diluent in immediate-release quercetin tablets. The powders were characterized by physicochemical, granulometric, morphological, and surface properties, and compared with conventional excipients, including partially pregelatinized corn starch and spray-dried lactose monohydrate. Refractance window drying improved solubility, flowability, and structural integrity, while convective drying produced finer, more porous particles with lower water activity. Tablets formulated with both powders showed adequate hardness, low friability, and disintegration times under five minutes. All systems achieved complete quercetin release. Kinetic modeling revealed anomalous, matrix-regulated transport, with Weibull and Modified Hill models providing the best fit. Based on these results, pitaya peel powder could be considered a suitable diluent for the development of immediate-release tablets, offering functional performance aligned with sustainable formulation strategies. Full article

The global insect farming sector is rapidly expanding, driven by rising demand for sustainable protein sources and its potential to contribute to food security solutions. This study focuses on the quantification of chitin by comparing two gravimetric methods (ADF-ADL and crude fiber estimation) with a purification method considered as a reference method. It also aims to use the near-infrared spectroscopy (NIRS) to rapidly assess the quality of insect meals, in particular the macronutrients (moisture, protein, fat) and chitin content in a large data set of insect samples. Both alternative methods overestimated chitin content compared to the enzymatic purification method, which is the most reliable but more complex and expensive. Given their advantages (fairly simple, no significant investment, higher sample throughput, relatively short time execution), they can serve for rapid screening when precise chitin determination is not required. Calibration models showed good performance, particularly for protein and fat determination, and satisfactory results for chitin prediction. The NIRS models show promises for rapid and reliable prediction of insect products, although the chitin assessment remains to be further validated. Its implementation could streamline chemical quality control in insect-based food and feed production, offering speed and flexibility for industrial applications. Full article

This paper proposes a methodology for implementing a custom-developed explainability model for credit rating using behavioral data registered during the lifecycle of the borrowing that can replicate the score given by the regulatory model for the solidarity economy in Colombia. The methodology integrates continuous behavioral and financial variables from over 17,000 real credit histories into predictive models based on ridge regression, decision trees, random forests, XGBoost, and LightGBM. The models were trained and evaluated using cross-validation and RMSE metrics. LightGBM emerged as the most accurate model, effectively capturing nonlinear credit behavior patterns. To ensure interpretability, SHAP was used to identify the contribution of each feature to the model predictions. The presented model using LightGBM predicted the credit risk assessment in accordance with the regulatory model used by the Colombian Superintendence of the Solidarity Economy, with a root-mean-square error of 0.272 and an R² score of 0.99. We propose an alternative framework using explainable machine learning models aligned with the internal ratings-based approach under Basel II. Our model integrates variables collected throughout the borrowing lifecycle, offering a more comprehensive perspective than the regulatory model. While the regulatory framework adjusts itself generically to national regulations, our approach explicitly accounts for borrower-specific dynamics. Full article

Smoking tobacco is a prominent activity in Cameroon, with each region holding different views on the devices used for smoking. In Bamum, these vessels are called kiis. Many of these pipes, or kiis, have been removed from the kingdom and displayed without proper contextual information in Western institutions since the 1920s. This paper highlights discrepancies in academic pursuits regarding the kii and their decontextualized displays, while also providing ethical guidelines for their future displays. Understanding the intended purpose and cultural significance of a kii allows for the process of restitution in the form of ethical display to take place. Using the Heritage Context Retrieval Analysis (HeCRA) method, the research aim to explore the cultural origins of the kii in the GWU collection, retrieve its cultural context, critique the prevalent cabinet of curiosities display format used in displaying them in museums, and propose ethical frameworks for handling such devices, which are both utilitarian and culturally charged in 21st-century museums. This paper uncovers the true identity of a brass kii and dismantles the cabinet of curiosities and the alignment of African tangible heritage to oddities. The goal is to instigate a new approach to approaching such cultural objects by invoking their original spiritual and cultural symbolism in exhibitions outside of Bamum. Full article

Background: Skin aging is mainly associated with oxidative stress and enzymatic degradation of collagen and elastin by protease activity. Peptides have antioxidant capacity and inhibitory effects on protease enzymes. Objective: The purpose of this study was to obtain peptides with in vitro anti-aging activity from the enzymatic hydrolysis of bovine casein with actinidin, a protease extracted from the green kiwi fruit (Actinidia deliciosa) Methodology: The enzyme actinidin was extracted from the pulp of the kiwi fruit, purified by ion exchange chromatography and characterized by polyacrylamide electrophoresis (SDS-PAGE). Subsequently, the extracted enzyme was used to hydrolyze commercial bovine casein at 37 °C for 30 min, precipitating the peptide fraction with trichloroacetic acid (TCA), and centrifuged. To determine the anti-aging potential of the peptides in vitro, antioxidant activity was evaluated using the ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical. Additionally, the inhibitory capacity of the peptides against collagenase and elastase enzymes was also studied. To complement the in vitro results, the enzymatic hydrolysis of casein with actinidin was simulated. The binding energy (ΔG) of each of the hydrolysates with the collagenase and elastase enzymes was calculated using molecular docking to predict the peptide sequences with the highest probability of interaction. Results: Actinidin was extracted and purified exhibiting a molecular weight close to 27 kDa. The enzyme hydrolyzed the substrate by 91.6%, and the resulting hydrolysates showed moderate in vitro anti-aging activity: antioxidant (17.5%), anticollagenase (18.55%), and antielastase (28.6%). In silico results revealed 66 peptide sequences of which 30.3% consisted of 4–8 amino acids, a suitable size to facilitate interaction with structural targets. The sequences with the highest affinity were FALPQYLK and VIPYVRYL for collagenase and elastase, respectively. Conclusions: Despite the modest inhibition values, the use of a fruit-derived enzyme and a food-grade substrate is in line with current trends in sustainable and natural cosmetics. These findings highlight the great potential for laying the groundwork for future research into actinidin-derived peptides as multifunctional and eco-conscious ingredients for the development of next-generation anti-aging formulations. Full article

Climate change affects all human and ecological systems. The rapid climate impacts are increasingly evident on all economic activities, including tourism. Regarding the fact that “the window is closing”, climate resilience is urgently needed to protect tourism resources and maintain the quality of tourism offerings. Since the recent climate and tourism scientific literature emphasizes the necessity to mobilize existing knowledge, standardize practices, and explore appropriate tools related to tourism adaptation, we provided desk research and discussed the latest achievements of the Intergovernmental Panel on Climate Change’s (IPCC) and related knowledge platforms. According to the results of this review, it seems that the vast majority of the authors use vulnerability assessment (VA) to provide a solid basis for climate change adaptation (CCA) options applicable to tourism. Also, there is a lack of application of the latest IPCC recommendations founded in climate risk assessment (CRA). In the context of CRA, vulnerability was often assessed in a static way, with limited consideration of future hazards, probabilistic estimates, and the interactions between climatic and non-climatic drivers. Moreover, the methodologies applied to assess climate-related issues in tourism have been highly heterogeneous, hindering comparability and aggregation of results. Since risk is a useful conceptual framework for understanding tourism’s climate issues and modalities to reach its climate resilience, we discussed the significance of shifting the vulnerability concept towards a risk-centered framework. This review paper also provides a basis for a common understanding of CRA, a step-by-step approach to its assessment, and the explanation of CCA options to strengthen the tourism community, since a decisive decade of climate action is upon us. Full article

In the domain of Shape Encoding, the approximation of the Medial Axis of a solid region in ${\mathbb{R}}^3$ with Boundary Representation M, is relevant because the Medial Axis is an efficient encoding for M in Design, Manufacturing, and Shape Learning. Existing Medial Axis approximations include (a) full Voronoi and (b) and partial Shape Diameter Function (SDF)-based ones. Methods (a) produce large high-frequency data, which must then be pruned. Methods (b) reduce computing expenses at the price of not handling some shapes (e.g., prismatic), and currently, they only synthesize 1D Medial Axes. To partially overcome these limitations, this investigation performs a direct synthesis of a 1D and 2D simplex-based Medial Axis approximation by a combination of stochastic geometric reasoning and graph operations on the SDF-originated point cloud. Our method covers one- and two-dimensional Simplicial Complex Medial Axes, thus improving on 1D Medial Axes approximation methods. Our approach avoids the expensive full computing plus pruning of Medial Axis based on Voronoi methods. Future work is needed in the synthesis of Medial Axis approximation for high-frequency neighborhoods of mesh M. Full article

Background/Objectives: The rational design of modified-release matrix tablets requires a thorough understanding of granulometric analysis, compaction behavior, and drug release profile. In this study, we evaluated the physicochemical, granulometric, and mechanical properties of hydroxypropyl methylcellulose, polyethylene oxide, and ethylcellulose in galantamine matrix formulations. Methods: Spectroscopic (FTIR) and thermal (DSC) analyses demonstrated drug–polymer compatibility. We assessed flowability, cohesion, and aeration behavior through granulometric analysis and applied compressibility models (Kawakita, Heckel, Leuenberger) to characterize deformation mechanisms. Results: Hydroxypropyl methylcellulose showed superior compactability (T_max = 4.61 MPa) and sustained drug release (85.4% at 12 h, DE% = 62.2%), while polyethylene oxide enabled gradual erosion and consistent delivery (88.7% at 12 h, DE% = 57.5%). In contrast, ethylcellulose exhibited high cohesiveness but poor matrix integrity, leading to premature drug release (76.6% at 1 h, DE% = 73.7%). Only hydroxypropyl methylcellulose and polyethylene oxide formulations met USP criteria. Conclusions: These results demonstrate that polymer selection critically influences powder behavior and matrix performance, underscoring the need for integrated granulometric and mechanical evaluation in the development of robust controlled-release systems. Full article

Cloud-aerosol interactions represent a critical uncertainty in climate systems. Using 2006–2021 CALIPSO products, we investigated upper tropospheric clouds and aerosol layers across four Russian regions: Western Plains, West Siberian Plain, Central Siberian Plateau, and Eastern Mountains. Top Cloud Optical Depth (TCOD), Top Depolarization Ratio of clouds (TDRc), and Layer Level (LLc) exhibit pronounced seasonal and diurnal variations, peaking during summer and nighttime when convection intensifies. Upper aerosol layers show low Total Aerosol Optical Depth (TAOD) and Color Ratio (CRa), often displaying multi-layered structures influenced by spring–summer dust transport and biomass burning. We constructed a correlation matrix of 49 parameter pairs (7 cloud × 7 aerosol parameters), revealing moderate positive correlations between cloud and aerosol layer heights under coexistence conditions. TDRc showed weak linear but strong nonlinear relationships with aerosol parameters, indicating complex coupling mechanisms beyond simple linear models. Nighttime observations demonstrated superior signal-to-noise ratios and correlation coefficients compared to daytime measurements. These findings enhance understanding of cloud-aerosol coupling at middle-high latitudes, providing parameterization constraints for improving global climate model representations of these processes. Full article