Search Results (912)

Because wood anatomical traits and tree-ring features vary with species and climatic regime, cellular-scale measurements complement ring-width chronologies and help with understanding how forests may respond to future environmental change. We developed anatomical chronologies spanning the 1900–2019 period from multi-century old yellow pines (Pinus jeffreyi Balf. and P. ponderosa P & C Laws.) at four sites surrounding the Tahoe Basin of the Sierra Nevada, at the border between Nevada and California, USA. Measurements of earlywood and latewood traits included lumen area, lumen length, lumen width, wall length, wall-to-lumen length ratio, and conductive area. Climate sensitivity was estimated by bootstrapped response functions with precipitation and temperature (monthly and seasonal) from the Global Historical Climate Network interpolated to the site locations. Moisture emerged as the primary control on anatomical trait expression, as significant coefficients involved precipitation rather than temperature. Earlywood lumen size and conductive capacity were associated with late winter through spring moisture, while cellular wall characteristics were connected with conditions during the growing season. Overall, our study provided new insights into the potential impacts of climatic changes on woody species of remarkable size and longevity in mountain forest ecosystems. Full article

Proteins with additives, especially in small quantities, are of great interest as a subject of study. Machine learning approaches implemented on Raman spectroscopy data could provide an insight into the chemical structures of such mixtures or conjugates. Although decision tree models could be powerful in solving either classification or regression tasks and could provide accessible predictions, they are prone to overfitting. Ensemble models that implement several decision trees could overcome the determined problem. Five different model types are discussed: RandomForest, GradientBoosting, AdaBoost, Voting, and Stacking. Raman spectroscopy data of whey protein isolates (5 wt.%) with different amounts of hyaluronic acid (0, 0.1, 0.25, and 0.5 wt.%) were used as datasets. In order to generalize the results of the study, WPI samples from three different manufacturers were used. Optimization established that ensembles of 200 decision trees with a maximum depth of four were optimal. The Stacking algorithm, which used RandomForest, GradientBoosting, and AdaBoost as base models with either LogisticRegressor (classification task) or RidgeCV (regression task), was found to be the most efficient in finding differences between the whey protein isolate and its conjugates with hyaluronic acid: specificity of 68.7% and sensitivity of 95.4% (classification task); R² = 0.764 with mean absolute error of 0.068 (regression task). According to the feature importance plots, the Raman bands that were most influential in predicting the results were 1003 cm⁻¹ (phenylalanine, ring breath), 1125 cm⁻¹ (rocking of NH₃⁺), 1206 cm⁻¹ (C–C stretching), 1240 cm⁻¹ (amide III (β-sheet), N–H in-plane bend, C–N stretch), and 1399 cm⁻¹ (aspartic and glutamic acids, C=O stretch of COO–). The findings of this study may contribute to the development of novel methods for quality control and analysis of complex multicomponent systems in various industrial settings. In particular, the ensemble approach can be adapted for monitoring in food processing or as a screening tool in pharmaceutical formulation development. Full article

Background: Interventional cardiology is increasingly being reshaped by rapid progress in non-invasive cardiovascular imaging. Coronary computed tomography angiography (CTCA), once used mainly to exclude obstructive coronary artery disease (CAD), is now being adopted as a broader planning instrument before percutaneous coronary intervention (PCI). Its ability to generate high-resolution three-dimensional visualization of the coronary tree, together with functional assessment through CT-derived fractional flow reserve (FFR-CT) and more advanced plaque analysis supported by artificial intelligence (AI), has expanded its relevance from diagnosis alone to strategic procedural preparation. In this setting, CTCA can help refine lesion assessment, anticipate technical complexity, and support better procedural and clinical outcomes. Technological Advancements: The value of CTCA for both diagnosis and risk stratification has increased substantially with recent technical innovation. Among the most important developments is the maturation of FFR-CT, which enables non-invasive physiological interrogation of coronary stenoses using computational modeling. At the same time, artificial intelligence and deep learning tools are reshaping the CTCA workflow by improving automation, facilitating plaque analysis, and highlighting adverse plaque characteristics such as positive remodeling, spotty calcification, and the napkin-ring sign. Clinical Applications: In modern catheterization practice, CTCA is increasingly used to address anatomically demanding scenarios. Its role is particularly valuable in chronic total occlusion (CTO) intervention, where it can delineate occlusion length, stump characteristics, vessel course, and collateral anatomy before the procedure. Its usefulness also extends beyond CTO PCI by supporting vessel sizing, stent planning, and anticipation of lesion preparation requirements in complex coronary disease. Challenges: Despite these advantages, several barriers continue to limit wider implementation, including blooming from heavy calcification, radiation burden, contrast-related renal concerns, and the practical difficulty of embedding CTCA-based planning into routine workflows. Conclusions: CTCA is becoming an increasingly important adjunct in PCI planning because it can combine anatomical definition, physiological interpretation, and plaque-level information before invasive treatment is undertaken. Overall, this review emphasizes CTCA not only as a diagnostic modality, but also as a practical pre-procedural roadmap that can guide lesion selection, stent planning, calcium modification strategies, and overall PCI strategy. Full article

Canarium luzonicum (Blume) A. Gray, a tree endemic to the Philippines, is the source of Manila elemi, an oleoresin shown to have anti-infective properties owing to its rich terpenoid content. However, its leaves have not yet been subjected to in-depth phytochemical studies. C. luzonicum leaf compounds were isolated by multiple chromatographic techniques and elucidated by 1D and 2D NMR, MS, Polarimetry, IR, CD, and chemical reaction techniques. As a result, four new megastigmane glycosides, canariluzoniosides A–D (1–4), and two new monoterpenoid glycosides, canariluzoniosides E and F (5–6), were identified along with 29 additional known compounds. Canariluzonioside A (1) was a unique megastigmane featuring a tricyclic ring system. The new glycosides’ sugar moieties were obtained by acid hydrolysis and confirmed by HPLC-OR. Aglycones were liberated by enzymatic hydrolysis and were structurally characterized, one of which was the new compound, named canariluzonol A (1a). Finally, most compounds were screened for cytotoxicity against A549 human lung cancer cell line and for inhibition against Leishmania major promastigotes. Notable bioactivity was observed in known 3,4-seco-A-ring triterpenoids such as canaric acid and nyctanthic acid, for which revision of spectroscopic data is also proposed. Full article

Urban trees are increasingly exposed to persistent anthropogenic drivers that extend beyond climatic forcing and fundamentally alter the conditions of secondary growth. While climatic controls of cambial phenology and xylogenesis are well established, the mechanisms by which non-climatic drivers regulate cambial activity and wood formation remain fragmented and are often inferred only indirectly. Here, we develop a cambium-centred framework to synthesise current evidence on how anthropogenic drivers shape wood formation in urban and peri-urban trees. To our knowledge, this is among the first syntheses explicitly linking anthropogenic drivers to distinct stages of xylogenesis. Anthropogenic drivers are typically chronic, spatially heterogeneous, and temporally decoupled from seasonal climatic rhythms, and may alter cambial kinetics and generate anatomical signatures not captured by ring width alone. We evaluate major driver domains, including root-zone constraints, altered hydrology, urban microclimate, pollution, salinity, and mechanical disturbance, while also considering emerging drivers such as artificial light at night and microplastics. Evidence is stratified into three levels: direct observations, indirect physiological evidence, and mechanistic plausibility. Across driver classes, three recurrent anatomical patterns emerge: reduced conduit size under hydraulic or osmotic stress; anomalies in wall deposition under carbon limitation or oxidative stress; and pronounced circumferential heterogeneity under spatially localised forcing. Integrative approaches combining xylogenesis monitoring, quantitative wood anatomy, dendrometer observations and spatially explicit sampling are essential to disentangle anthropogenic from climatic effects and improve assessment of tree resilience. Full article

The response of tree growth to environmental (climatic) changes has largely been analyzed through ring width–climate relationships, yet such analyses often lack the dynamic process of radial growth in response to environmental changes. Therefore, this study focuses on Korean pine (Pinus koraiensis Siebold & Zucc.) and white birch (Betula platyphylla Sukaczev) at three elevations (750 m, 950 m, and 1150 m) in the broadleaved Korean pine forest on the northern slope of Changbai Mountains, China. We systematically monitored cambial activity and the dynamics of xylem formation stages to analyze the different adaptation strategies of the two species in terms of phenology, cellular characteristics, growth rates, and climatic responses during cambial and xylem formation stages. The results showed that the phenological stages of xylem formation in Korean pine were more sensitive to elevation, while the phenological changes in birch were smaller, indicating greater growth stability. The seasonal dynamics of the number of xylem cell layers in both species followed a unimodal or sigmoid curve, but high elevations significantly inhibited the number of mature cell layers. Gompertz model fitting revealed that the maximum growth rate of Korean pine decreased significantly with increasing elevation, whereas no significant change was observed in birch. With increasing elevation, temperature emerged as the primary factor influencing cambial phenology and growth duration in both species, while precipitation dominated changes in growth rates. Xylem growth in Korean pine was co-regulated by growth rate (R² = 0.62) and growth duration (R² = 0.35), with tracheid diameter closely related to the duration of expansion (R² = 0.36). The regulatory pattern of xylem growth in birch was similar to that in Korean pine but with weaker correlations. In summary, Korean pine, as a coniferous dominant species, is more sensitive to temperature changes induced by elevation and adapts to elevational variations by adjusting phenology and cell development. In contrast, birch, as a broadleaved pioneer species, exhibits a high buffering capacity in xylem formation in response to elevational changes, thereby maintaining growth stability. The divergent growth strategies of the two species reveal the potential response pathways of temperate forest tree species to environmental changes and provide important insights for predicting the dynamics of broadleaved Korean pine forests. Full article

Giant cantilevered tree-shaped steel structures are highly susceptible to cumulative deformation and geometric deviation during staged construction due to their complex spatial configuration, long cantilever characteristics, and nonlinear load transfer mechanisms. To address these challenges, this study investigates deformation monitoring and control of such structures based on 3D laser scanning, taking the “Tree of Life” project as a representative case. A high-precision full-field monitoring system is established to acquire multi-stage point cloud data throughout the construction process. The collected data are registered with the BIM model to quantify spatial deviations and track the deformation evolution of key structural components. Meanwhile, a staged preloading–unloading strategy is implemented to simulate operational loads, reconstruct load transfer paths, and regulate structural deformation during construction. Based on continuous field measurements, the deformation characteristics of different structural regions, including ring beams, rotating platforms, and trunk–branch systems, are systematically analyzed. The results indicate that the structure exhibits a pronounced global torsional deformation pattern. The displacement of ring beams ranges from 40.35 mm to 80.15 mm, while the maximum local displacement reaches 131.37 mm in geometrically complex regions, primarily attributed to the coupling effects of complex geometry, long cantilever action, stiffness discontinuity, and load concentration. Furthermore, deformation exhibits a progressive and stage-dependent accumulation pattern under sequential loading–unloading processes. The proposed monitoring and control approach achieves millimeter-level accuracy and enables effective feedback for construction adjustment and deviation mitigation. The integration of 3D laser scanning with staged load regulation provides a reliable technical framework for deformation monitoring and control of complex cantilevered steel structures. While the findings are based on a single complex project, further validation on additional cases is required to fully establish the general applicability of the proposed framework, although its integration of 3D monitoring, BIM registration, and staged load regulation suggests potential transferability to other large-scale cantilevered steel structures with similar geometric complexity. Full article

Tree rings record environmental conditions and can serve as long-term biomonitors of urban pollution. This study evaluated the radial growth and chemical composition of Pinus greggii wood in three urban green areas of Mexico City: San Juan de Aragón Park (SJA), Sierra de Guadalupe State Park (GUAD), and Vivero Coyoacán National Park (COY). Tree ring chemical elements were analyzed at annual resolution for the period 2002 to 2022, and their relationships with atmospheric pollutant concentrations, including nitrogen oxides (NO_x), carbon monoxide (CO), ozone (O₃), and particulate matter (PM), of medium size or smaller than 10 µm, including the fractions PM_2.5 and PM₁₀, were assessed using a spatial scaling approach. Elemental concentrations were determined using X-ray fluorescence (XRF). Statistical analyses included analysis of variance (ANOVA), Theil–Sen trend estimation, and Pearson correlation with lag analysis (up to 3 years). The oldest trees were recorded in COY (52 years), while the youngest were recorded in GUAD (13 years). Distinct temporal patterns in elemental concentrations were detected among sites; for instance, peak concentrations of Fe (307 ppm), Cu (11 ppm), and Zn (51 ppm) occurred in GUAD in 2021, while Pb concentrations declined during 2019–2020 across all three sites. Significant correlations (p < 0.05) were identified between Cu, Fe, Zn, and Pb and the atmospheric pollutants (NO_x, PM_2.5, PM₁₀, O₃). Notably, O₃ showed significant positive correlations with Fe at SJA (up to r = 0.80) and GUAD (up to r = 0.46) with lags ranging from 0 to 3 years, suggesting delayed responses between atmospheric pollution and elemental deposition in tree rings. These findings highlight the sensitivity of P. greggii to urban atmospheric pollution and support its potential as a long-term biomonitoring tool, as well as its importance for informing policies aimed at improving air quality and promoting the sustainable management of urban green spaces. Full article

Urban trees are increasingly deployed as nature-based infrastructure to mitigate heat and manage stormwater, yet quantitative guidance on how species traits and site context shape transpiration remains fragmented. We conducted a systematic metadata analysis of seven field studies that measured daily transpiration rate in urban settings using heat-pulse methods. The units and spatial scales reported were harmonized with the sap flow density across active sapwood (J_s, g H₂O/${\mathrm{cm}}^2$/day) by converting reported stand transpiration and the outer 2 cm of sapwood sap flux using established Gaussian radial distribution functions for angiosperms and gymnosperms, which account for the non-linear decline in sap flux from the vascular cambium to the heartwood boundary. We then summarized distributions and tested group differences with Kruskal–Wallis and Dunn post hoc comparisons across wood anatomy, climate, soil texture, and planting configuration. Conifers exhibited significantly lower median $J_s$ (39.76 g/${\mathrm{cm}}^2$/day) than angiosperms, while the ring-porous group (median $J_s$ = 92.25 g/${\mathrm{cm}}^2$/day) and diffuse-porous groups (median $J_s$ = 96.70 g/${\mathrm{cm}}^2$/day) had similar distributions overall. Climate-modulated responses within wood anatomy groups differed, with diffuse-porous species exhibiting the highest median $J_s$ (152.59 g/${\mathrm{cm}}^2$/day) in semi-arid regions, ring-porous species maintaining comparatively stable median $J_s$ across climates (varying slightly between 80.72 and 99.32 g/${\mathrm{cm}}^2$/day), and conifers reaching their highest median $J_s$ (69.90 g/${\mathrm{cm}}^2$/day) in humid continental sites. Soil texture effects were consistent with moisture availability: sandy loam generally reduced $J_s$ relative to loam or silt loam for conifers and diffuse-porous species. Across anatomies, single trees transpired more than clustered trees or closed canopies. For example, planting as single trees increased median $J_s$ by 86% in conifers (from 33.01 to 61.37 g/${\mathrm{cm}}^2$/day) and by 45% in diffuse-porous species (from 81.31 to 118.25 g/${\mathrm{cm}}^2$/day). These results provide actionable ranges and contrasts to inform species selection and planting design for urban greening and runoff reduction, while highlighting data gaps for future research. Ultimately, by matching specific wood anatomies and planting configurations to local soil and climatic conditions, urban planners and ecohydrologists can strategically optimize urban forests to maximize targeted ecosystem services. Full article

Extreme drought events are increasingly destabilizing European lowland oak forests, yet within-stand variation in drought legacy effects remains poorly characterized. This study integrates UAV-LiDAR canopy structural analysis with a 68-year dendrochronological record (1952–2019) to examine divergent radial growth responses to the 2012 extreme drought in Turkey oak (Quercus cerris L.) forests of Vojvodina, northern Serbia. LiDAR scanning (Wingtra Gen II, 90 m altitude, spring 2024) enabled objective classification of 180 increment cores from 90 trees across four 5–7 ha experimental plots into two structural zones: a preserved-structure zone (PS; gap fraction ≤ 10%) and a disturbed-structure zone (DS; gap fraction > 10%). Ring width index (RWI) chronologies were developed using the modified negative exponential function and analyzed with linear mixed-effects models (LMMs) incorporating AR(1) temporal autocorrelation. Lloret resilience indices (a reference window of seven years) were computed per individual tree and compared between zones using Mann–Whitney U tests with Bonferroni correction. The key finding is a statistically significant zone × period interaction in all four plots (p = 0.0009–0.033): DS zone trees exhibited a marked post-drought RWI increase (mean +0.22–0.36 units; t-test p < 0.0001 in all plots), while PS zone trees showed no significant post-drought change (p = 0.147–0.258). Pooled Lloret analysis revealed significantly higher recovery (Rt: DS median = 1.693 vs. PS = 1.237; U = 1633, p < 0.0001, r = 0.532) and resilience (Rs: DS = 1.232 vs. PS = 0.932; U = 1574, p < 0.0001, r = 0.482), while resistance (Rc) did not differ between zones (p = 0.569), indicating that DS zone trees were equally susceptible to the drought but recovered far more strongly. The equivalence of Rc between zones critically implies that divergent post-drought trajectories cannot be attributed to differential drought tolerance but instead reflect a structural mechanism operating exclusively in the post-drought period. These results are consistent with a competition release mechanism: drought-induced canopy gap formation in DS zones reduced inter-tree competition for surviving trees, enabling accelerated radial growth recovery. Full article

This study reconstructs annual streamflow variability in the Yenice Stream Basin (northwestern Türkiye) for the period 1809–2020 using tree-ring data, substantially extending the short instrumental record (1979–2020). Three moisture-sensitive conifer chronologies were integrated using principal component analysis (PCA), and the first two principal components were employed as predictors in a multiple linear regression model calibrated against observed streamflow. The model explains a significant proportion of interannual variability (R² = 0.39; adjusted R² = 0.36; p < 0.001). Temporal stability was assessed using a 30-year moving-window correlation analysis, which reveals consistently positive and statistically significant relationships across all subperiods, indicating a stable and persistent calibration relationship through time. Years exceeding ±1 standard deviation account for approximately 24% of the record, while extreme events (±2 standard deviations) represent about 5%. The reconstruction identified several extreme events, including severe drought years (e.g., 1840, 1887, and 1907) and extremely wet years (e.g., 1896 and 1936). Among these, 1887 stands out as one of the most severe drought years, while the period 1927–1928 represents a persistent low-flow episode. The reconstruction provides a long-term perspective on streamflow variability and contributes baseline information for regional water resource planning and hydroclimatic risk assessment. Full article

Species distribution models (SDMs) are widely used to define climatic constraints on species ranges, yet their ability to reflect demographic processes remains poorly understood. We integrated annually calibrated SDMs (1981–2005) with tree-ring width data from 15 European forest species in the Iberian Peninsula to evaluate if climatic suitability mirrors tree growth, particularly for populations at their climatic tolerance limits. Our results show that higher suitability consistently relates to reduced growth decline, acting as a reliable proxy for forest vigor. Notably, interannual variability in climatic suitability was positively associated with growth, suggesting that climatic fluctuations may enhance physiological resilience. We also found that Mediterranean species exhibit higher growth sensitivity to climatic suitability changes than Eurosiberian species. These findings demonstrate that SDMs can capture functional constraints beyond mere presence, positioning annual climatic suitability as a key predictor of radial growth and offering valuable insights for forest management under climate change. Full article

Bisphenol S (BPS) is widely used as a replacement for bisphenol A, yet accumulating evidence suggests that it has comparable endocrine and cardiovascular toxicity. Here, we investigated whether prolonged low-dose BPS exposure induces subtle but classifiable phenotypic alterations in human coronary artery endothelial cells (HCAEC), using an end-to-end experimental and ML pipeline that spans cell culture, high-content imaging, feature extraction, and robust classification. Cells were exposed to 0.1 µM BPS for 96 h and profiled using a cell painting assay and high-content microscopy. Image segmentation yielded ~2500 quantitative features per cell across four compartments—Membrane, Cytoplasm, Ring region (i.e., perinuclear region), and Nucleus—for multiple fluorophores. We systematically compared different classifiers (Random Forest, XGBoost, LASSO logistic regressor) using feature selection (MRMR, ReliefF, LASSO) or transformation-based dimensionality reduction (PCA, autoencoders). Tree-based ensembles robustly handled high-dimensional inputs, with XGBoost combined with ReliefF-selected features achieving the best performance. The most informative descriptors predominantly mapped to mitochondrial and nuclear channels, indicating early alterations in mitochondrial organisation and chromatin-related features. These findings show that chronic low-dose BPS exposure elicits a distinct endothelial phenotype, consistent with early endothelial dysfunction, and demonstrate that integrating high-content imaging with machine learning provides a sensitive, scalable framework for vascular toxicity assessment of environmental contaminants. Full article

The radial growth of the tree stem reflects tree responses to climate change. This study examines the response of Fagus orientalis to more than half a century of climate dynamics in Armenia using a dendrochronological approach. Two forest stands were analyzed: one geographically isolated stand in the arid southern part of the country and one stand in the mesic northern mountainous region, where the main beech forests are distributed. The study period was divided into two phases (1965–1993 and 1994–2023). Climate dynamics were assessed by the months of the biological year, from October of the previous year to the end of September of the current growing season. Substantial warming trends were detected at both stands, except in November, December, and April, and in July in the northern part of Armenia. Between periods, the mean ring width increased from 1.67 mm to 2.14 mm at the northern stand, while decreasing from 1.95 mm to 0.89 mm at the southern stand. Despite climate warming and declining precipitation, some study trees exhibited increased (northern) or stable (both stands) radial growth. Comparison of the two periods revealed pronounced ecological and tree-specific variability in climate–growth relationships, including shifts in correlation strength and sign reversals. These patterns were primarily driven by climate sensitivity rather than age-related effects. The results provide valuable insights for conserving the southern stand and may support assisted migration strategies for F. orientalis toward the southern margin of the F. sylvatica distribution range. Full article

Global warming, which is mainly linked to CO₂ increase, has led to a growing interest in assessing carbon conservation in forest biomass. Despite evidence that treelines have advanced by hundreds of meters, knowledge of associated stand biomass changes is insufficient for comprehensive estimation of their role in carbon sequestration. Traditionally, the biomass assessment is based on data collected by field measurements. While this approach provides accurate data for local sites, it cannot be extrapolated properly to larger areas. A more appropriate approach would be to combine field measurements with remote sensing methods. We used data obtained by tree morphometry and annual ring measurements, model-based biomass estimation, processing of laser scanning results, and satellite imagery to model and calculate changes in stand above-ground biomass (AGB) since 1900 at treeline ecotone in Altai and Western Sayan. We developed simulations to predict AGB changes over the coming four decades in these regions. Our findings revealed that the upslope shift of the treeline ecotone by 58–86 m of altitude over the past century was accompanied by an exponential increase in AGB of stands within the 200–400 m forest–tundra transition zone. This resulted in an AGB increment of 120–139 tons per 100 m of treeline. We expect that stand AGB at the treeline ecotone will become 2.3–3.3 times bigger by 2060. All exposures must be considered when estimating stand AGB within treeline ecotones because there are significant differences in treeline elevation, tree-dominant proportions, and stand structure on different slopes. Full article