Bell-shaped Pattern Research Articles

Oscillatory nonlocal solitons confined by a rectangular boundary

Abstract We investigate solitons in nonlinear media with oscillatory nonlocal response, which are confined within a rectangular boundary. We find that the profile of soliton exhibits a nearly Gaussian shape regardless of the boundary value, and is located in the center of the rectangle. The profile of nonlinear refractive index, which exhibits a bell-shaped or oscillatory pattern, is strongly related to the value of the boundary and the degree of nonlocality. The normalized amplitude can also influence the profile of nonlinear refractive index. The stability of the soliton depends on its location within the domain defined by the function relationship curve of the propagation constant and the boundary, the degree of nonlocality, or the normalized amplitude. We further demonstrate the robustness of soliton propagation by the application of initial transverse velocity on solitons and the incident of solitons deviating from the center of the system, resulting in a snake-shaped propagation and chaoticon-shaped pattern.

Activity pattern of antioxidant enzymes in relation to the time of exposure of hexavalent chromium to Nile tilapia Oreochromis niloticus.

Hexavalent chromium (Cr (VI)), a toxicant of environmental concern, frequently enters into water bodies and produces oxidative stress in fish. The antioxidant enzymes, Superoxide dismutase (SOD), Catalase (CAT), and Glutathion S-transferase (GST) are activated to counteract the oxidative stress in fish. This study explores the pattern of activation of these enzymes in gill, muscle, liver, and kidney tissues of Nile tilapia Oreochromis niloticus exposed to 9.35 mg/L and 18.70 mg/L of Cr (VI) for 96 h. The optimal hour of activity of these enzymes was revealed through extensive regression analysis. The results indicate a bell-shaped time response curve in the activity of the enzymes in both the treatments, except CAT in the gill of fish exposed to 18.70 mg/L Cr (VI) and GST in the gill, liver, and kidney of fish exposed to 18.70 mg/L Cr (VI). The results indicate that the optimal hour of activity of SOD changes in tandem with CAT, SOD responding first followed by CAT, both diminishing within 96 h. However, deviating from the bell-shaped pattern, the activity of CAT in gill and GST in gill, liver, and kidney in fish exposed to 18.70 mg/L Cr (VI) continued to rise even at 96 h, indicating that these antioxidant enzymes could not diminish the oxidative stress produced by the higher dose of Cr (VI). It was concluded that the activity of SOD, CAT, and GST between 30 and 70 h in the gill, liver, and kidney of Nile tilapia could serve as excellent biomarkers of oxidative stress under low doses of Cr (VI).

The rare earth elements and yttrium (REY) geochemistry of the upper Carnian (Upper Triassic) carbonates from northwestern Sichuan Basin (South China)

Rare earth elements and yttrium (REY) serve as valuable tracers of the geochemical properties of paleo-seawater and diagenetic processes. Four different carbonate components, ooids, microbalites, cements and brachiopods, from upper Carnian (Upper Triassic) of the northwestern Sichuan Basin were analyzed for REY geochemistry. Petrographic and cathodoluminescence analyses were employed to identify diagenetic features. The bright luminescent microspar calcite cement, ooids and the microbialites from the lower part of Qingyangou (HWQ) section exhibit bell-shaped REYSN patterns. Microbialites from the upper part of HWQ section have relatively high REY concentrations with a flat REYSN pattern. The high content of ΣREY and terrigenous elements (e.g., Al, Zr, Th) in ooids and microbialites reflect the input of terrigenous clastic in the northwestern Sichuan Basin during Late Carnian. Articulated terebratulid brachiopods in the study area display a generally modern seawater-like REYSN pattern. However, this pattern may be influenced by the presence of sparry cement that has infilled the cracks and punctae of the brachiopod shells. The ooids, microbalites, cements and brachiopods are unsuitable for reconstructing the REY characteristics of Carnian seawater in the northwestern Sichuan Basin due to diagenetic alteration and terrigenous input. This study also highlights the necessity of thoroughly evaluating carbonate components for diagenetic effects and terrigenous contamination when employing them for REY characteristic reconstruction.

Fifty years marshland changes in a large floodplain lake: Natural driving or human impact?

Study region: Poyang Lake, the largest freshwater floodplain lake in China. Study focus: Marshlands in a floodplain, as the typical natural wetland offering vital habitats for various organisms, are sensitive to environmental changes. The spatiotemporal changes of marshlands were investigated and their driving forces from both natural factors and human activities were discussed. The remote sensing image data from 1973 to 2022 was adopted to explore the long-term changes of marshlands exposed in dry season. New hydrological insights for the region: Over the past fifty years, the total area of marshlands in Poyang Lake is around 2540–2718 km2 and has undergone substantial changes. It follows the bell-shaped curve pattern with continuous rise since 1970s and reach the maximum at the end of 20 century and then fluctuating decline. Different evolutionary patterns were identified in different lake regions owing to the combination of human activities and natural processes. The expanding marshlands mainly concentrate in the central lake, while the significant losses of marshlands are observed in the northern lake（By sand mining and dyke constructions）. In the southern lake, sediment input from inflow rivers deposited naturally in the river mouth elevated the lake bed and lead to delta expansion（A 3.1 km expansion has been observed）. The complex geomorphological processes and fishery activities also create the dish-shaped internal sub-lakes in marshlands.

Impact of population ageing on cancer-related disability-adjusted life years: A global decomposition analysis.

As the global population ages, the burden of cancer is increasing. We aimed to assess the impact of population ageing on cancer-related disability-adjusted life years (DALYs). We used the decomposition method to estimate the impact of ageing, population growth, and epidemiological change on cancer-related DALYs from 1990 to 2019, stratified by 204 countries/territories and by their sociodemographic index (SDI). This approach separates the net effect of population ageing from population growth and change in age-specific DALY rates. Cancer-related DALYs among individuals aged ≥65 years increased by 95.14% between 1990 (52.25 million) and 2019 (101.96 million). Population growth was the main contributor to cancer-related DALYs (92.38 million, attributed proportion: 60.91%), followed by population ageing (41.38 million, 27.28%). Cancer-related DALYs attributed to population ageing followed a bell-shaped pattern when stratified by SDI, meaning they peaked in middle-SDI countries. Cancer-related DALYs attributed to ageing increased in 171 and decreased in 33 countries/territories. The top three cancer types with the highest increase in the absolute number of cancer-related DALYs associated with ageing were tracheal, bronchus, and lung (8.72 million); stomach (5.06 million); and colorectal (4.28 million) cancers, while the attributed proportion of DALYs was the highest in prostate (44.75%), pancreatic (40.93%), and non-melanoma skin (38.03%) cancers. Population ageing contributed to global cancer-related DALYs, revealing a bell-shaped pattern when stratified by socioeconomic development, affecting middle-SDI countries the most. To respond to the growing ageing population and reduce cancer-related DALYs, it is necessary to allocate health care resources and prioritize interventions for older adults.

Ecological groups of birds of Zhytomyr region (Ukraine) in relation to thermal regime and their future prospects in the context of global climate change

The potential impact of global climate change on the distribution of bird species can be predicted based on observed climate change and current knowledge of the factors affecting range boundaries. The concept of an ecological niche allows one to qualitatively and quantitatively characterise the impact of environmental factors on species. The study estimates the parameters of the thermal projection of the ecological niche of birds in Zhytomyr region, compares different approaches to modelling the response of species to the average annual temperature gradient, identifies ecological groups of birds based on their thermal gradient, and provides prospects for these ecological groups in the context of global climate change. The beta-function was found to reflect the reactions of different species within a single bell-shaped pattern across the entire gradient of the environmental factor. This makes it possible to estimate the optimal level for all bird species. Kurtosis can be used to distinguish between different response patterns within the beta model. Zero kurtosis indicates a symmetrical bell-shaped response. The relationship between the kurtosis of species response models and the optimum is complex. In general, species show negative kurtosis in the warm part of the range, indicating a sharp break in the species response curve in the warm part of the factor range. In the middle part of the factor range, the kurtosis value randomly fluctuates around zero, indicating a predominant tendency towards symmetrical response forms and the prevalence of the classical bell-shaped response model. The limits of variation of kurtosis are of great importance in the cold part of the range. The thermal projection of the ecological niche was used to divide bird species into ecological groups based on the position of the optimum zone and the width of the tolerance amplitude. It is shown that ecological groups differ in their prospects under global climate change. Stenotopic megatherms have the best prospects in the face of global climate change. The habitat conditions of all other bird species in the region will deteriorate over the next 70 years. The most threatening prospects should be expected for stenotopic microtherms. The stenotopic megatherms include 68 species, which is 25.9% of the total regional bird fauna. That is, global climate change poses a threat to 74.1% of the region's bird species. Stenotopic megatherms are typified by Anseriformes, Bucerotiformes, Gruiformes, and Pelecaniformes. It was predicted that Ciconia ciconia has the greatest prospects for expansion due to global climate change. The stenotopic microtherms are represented by 18 species, which is 6.9% of the regional avifauna. For these species, climatic conditions will significantly limit the number of favourable habitats. This ecological group is most strongly typified by for Galliformes, Piciformes, and Strigiformes. Climate change will lead to a shift in the range of Picus canus, which will reduce the abundance of this species in the region.

Abstract PO4-14-08: A gene expression-based classifier for HER2-low breast cancer

Abstract Background: The definition of HER2-low breast cancer from clinical trials of antibody-conjugated drugs (ADCs) relies on immunohistochemistry scoring (IHC). However, in daily-practice the accuracy of IHC is hindered by inter-observer variability in assessing HER2 non-overexpressing status. Here, we aimed to identify breast cancer primary tumors with low HER2 expression by leveraging gene expression profiling. Materials and methods: A discovery approach was applied to gene expression profile of internal INT1 (n= 125) and INT2 (n= 84) datasets. We identified specific differently expressed genes (DEGs) according to HER2 IHC categories 0, 1+, 2+ and 3+. Principal Component Analysis (PCA) was used to generate a HER2-low signature whose performance was confirmed in the independent INT3 (n= 95), and TCGA and GSE20194 publicly available datasets. The association between the HER2-low signature and HER2 IHC categories was evaluated by non-parametric Kruskal-Wallis (KW) test with post hoc pair wise comparisons (i.e. contrasts); the HER2-low signature discriminatory capability was assessed by estimating the area under the receiver operating characteristic (ROC) curve (AUC) with its corresponding 95% Confidence Interval (CI). Gene Ontology and KEGG analyses were performed to enrich the DEGs for functional information. Results: A 20-gene HER2-low signature, consisting of both up-regulated (n=11) and down-regulated (n=9) genes, was computed based on the DEGs according to HER2 IHC categories as follows: 11 genes specific for the 1+ category, 8 genes for the 2+ category, and 1 gene for the HER2-low category. HER2-low signature genes were significantly enriched with lipid and steroid metabolism pathways, peptidase regulation, and humoral immune response. The HER2-low signature levels demonstrated a significant association with HER2 IHC categories (KW p-value < 0.001) and were distributed in a bell-shaped pattern across IHC categories (low values 0 and 3+; high values 1+ and 2+), effectively distinguishing HER2-low from 0 (contrast p-value < 0.001) and 3+ (contrast p-value < 0.001). Notably, the signature levels were significantly higher in tumors scored with 1+ as compared to 0 (contrast p =0.002). The HER2-low signature association with IHC categories and discriminatory capability was confirmed in the independent INT3 and TCGA datasets with higher values in HER2-low compared to both 0 and 3+. The HER2-low signature achieved an AUC value of 0.72 (95%CI 0.62-0.83) in differentiating HER2 0/3+ from HER2 1+/2+ categories, which is worth noting in light of the individual ERBB2 mRNA AUC value of 0.48 (95%CI 0.34-0.62). Conclusions: The 20-gene HER2-low signature was generated by maximizing the differences in gene expression between tumors with different HER2 status according to IHC. In contrast to the previously published single ERBB2 gene expression assessment, our data presents compelling evidence for effectively distinguishing HER2-low tumors, including those scored as 1+ from HER2-0 tumors. Our signature holds potential in selecting novel candidates for ADC therapy. Citation Format: Serena Di Cosimo, Sara Pizzamiglio, Chiara Maura Ciniselli, Valeria Duroni, Vera Cappelletti, Loris de Cecco, Maria Carmen De Santis, Rosaria Orlandi, Marilena Iorio, Marco Silvestri, Giancarlo Pruneri, Paolo Verderio. A gene expression-based classifier for HER2-low breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-14-08.

Ideal Weight and Weight Discrepancy: A Study of Life Course Trajectories and Intercohort Change in the Netherlands.

Objective: This study examined how individuals' ideal weight and weight discrepancy (between ideal and actual weight) changed over the life course and across cohorts. Methods: The study used population-representative longitudinal data collected in the Netherlands (N = 61,431 observations between 2007 and 2018 among N = 13,409 individuals aged 16 to 80 and born 1927-2000). Results: Ideal weight increased linearly with age. Weight discrepancy showed a bell-shaped age pattern. Approximately half of the age-related increase in ideal weight was associated with concurrent increases in actual weight. Ideal weight and weight discrepancy increased slightly across cohorts. The cohort-related increase in ideal weight vanished after adjusting for change in actual weight. Analyses of population heterogeneity showed similar patterns of change in both outcomes across groups, although levels differed by gender, education, and migration status even after adjusting for differences in actual weight between these groups. Conclusion: These results show that ideal weight and weight discrepancy in the Netherlands change substantially with age and modestly across cohorts. Potential explanations include changes in physical appearance and in the importance of physical appearance.

Spawning behaviour of lake whitefish in Lake Huron revealed by fine-scale acoustic telemetry and Indigenous ecological knowledge

Lake whitefish (Coregonus clupeaformis) are ecologically, economically, and culturally significant across their range, yet little is documented about the species’ spawning behaviour. Here, we used a VEMCO Positioning System (VPS) and the local ecological knowledge of Saugeen Ojibway Nation in a Two-Eyed Seeing approach to characterize sex-specific movement patterns of lake whitefish at a spawning shoal in Georgian Bay, Lake Huron (Ontario, Canada). In fall 2020, 50 lake whitefish were tagged with acoustic transmitters and 28 of those fish were detected during the deployment of the VPS between 15 October 2021 and 18 January 2022. Occupancy of lake whitefish on the VPS followed a bell-shaped pattern, with an increase, plateau that lasted ∼1 week, and subsequent decrease in activity over a 48-day period demarcating the 2021 spawning season. Apart from 2 resident females, males appeared in the area first. Both sexes moved into shallower lake depths at night and deeper depths during the day. Females moved 18.0% faster than males during the day whereas males moved 39.5% faster than females at night. Depths occupied became shallower over time until the peak activity phase, followed by a transition back to deeper waters. Both sexes used a variety of habitats over the spawning season, including the main spawning shoal, sandy substrates, and steep slopes. These insights on the habitat usage and spawning phenology of lake whitefish provided through our Two-Eyed Seeing approach can help inform stewardship initiatives aimed at increasing recruitment of depleted populations of this important species.

Temporal constraints on hydrothermal circulation associated with strike-slip faulting in the Permian Maokou carbonates, central Sichuan Basin (SW China)

Despite the ubiquity of hydrothermal fluid circulation in the crust, its timing is difficult to precisely determine using traditional thermometric dating due to strongly disturbed geothermal fields. We present a case study from the mid-Permian hydrocarbon-bearing dolostone reservoirs, situated proximally to strike-slip faults in the central Sichuan Basin (China), to highlight the utility of carbonate in-situ U-Pb geochronology in delineating the timing of hydrothermal fluid flow. Matrix and void-filling cement dolomite phases were identified in the porous Maokou Formation carbonates. Predominantly manifesting as saddle dolomites along fractures, these cements yielded statistically homogeneous U-Pb ages (242.5 ± 3.1 Ma, 238.9 ± 8.2 Ma, 244 ± 15 Ma, and 239.2 ± 6.5 Ma), slightly postdating the established stratigraphic timeline (ca. 273 to 259 Ma). The narrow temporal span suggests early emplacement following a short burial, compatible with the petrographic observation of burial stylolites crosscutting saddle dolomites. Integrating shallow emplacement depths inferred from a comparison between the dolomite U-Pb ages and a published burial history, with fluid-inclusion microthermometry, elucidates the hydrothermal system that was once present in this field. The pervasive occurrence of hydrofracturing, along with dolomite geochemical indicators represented by bell-shaped (REE + Y) PAAS patterns and elevated Y/Ho ratios, provide additional evidence for the hydrothermal fluid injection and resulting dolomitization. The dolomites' positive Eu anomalies and the parent fluids’ 18O enrichment indicate a source from deeper basinal pore waters that have interacted significantly with ambient rocks. The overlying Triassic evaporites may have provided Mg-rich brines, mixing into the circulating hot fluids responsible for hydrothermal dolomitization. Our dolomite U-Pb ages coincide with the seismically estimated timing of transtensional strike-slip fault activation. This temporal correspondence, combined with spatial associations and lateral slickensides along fracture planes, suggests that the hydrothermal fluid movement is highly relevant to the active strike-slip faults. This observation reveals a previously unrecognized early-middle Triassic, structurally controlled hydrothermal activity in the region. We propose that this episode of hydrothermal circulation was driven by extensional tectonism in response to the spreading of the Proto-Tethys Ocean. This finding is not in line with the earlier research that considered late Permian Emeishan volcanism to have been the main trigger for hydrothermal fluid influx. The long-standing view regarding hydrothermal dolomitization in this region may need to be re-evaluated.

Deciphering the ore-forming process of Sb-W deposits through scheelite and stibnite trace element geochemistry

Antimony (Sb) and tungsten (W) and deposits typically form in distinct and unrelated ore-forming environments. However, in rare cases, ore deposits may present combined Sb-W mineralization within a single deposit. These contrasting occurrences introduce uncertainty within the Sb-W ore deposit model, which ultimately guides mineral exploration strategies. Scheelite and stibnite are prevalent ore minerals in Sb-W deposits, making their trace element compositions valuable for enhancing our understanding of the genesis of Sb-W ore systems. In this study, we conducted a systematic investigation of trace element compositions in scheelite and stibnite samples from the Chashan and Zhazixi Sb-W deposits in South China to decipher the primary ore-forming processes. Scheelite from the Sb-W deposits is characterized by low Na, Nb, Ta and Mo contents, and variable Nb/Ta ratios. These results present a remarkably different geochemical signature when compared with granite-related W deposits, indicating that W mineralization in Sb-W deposits was derived from a non-magmatic origin. Moreover, when combining the trace element signature with reported fluid inclusion and isotopic data, it can be concluded that ore-forming fluids of the Chashan and Zhazixi Sb-W deposits were primarily composed of deep-circulating meteoric groundwater. Scheelite from the Chashan deposit presents relatively flat REE patterns with large positive Eu anomalies, whereas the Zhazixi deposit is characterized by bell-shaped REE patterns with weak Eu anomalies. This suggests that the two Sb-W deposits may differ slightly in their source rock composition, which is also supported by the different trace element compositions of stibnite. Stibnite from the Zhazixi deposit is relatively enriched in As, Se and Pb, whereas stibnite from the Chashan deposit contains higher Sn, Zn, Mo, Ag, In and Sr, further indicating that the initial fluids of the two deposits may have undergone different degrees of fluid-rock interaction with their distinctive source rocks. This study demonstrates that the genesis of the Zhazixi and Chashan Sb-W deposits significantly differ when compared to the ore-forming processes that control granite-related W or metamorphic W deposits. Moreover, the formation of these Sb-W deposits appears to share a similar genetic model consistent with low-temperature Sb deposits in South China. In this model, deep-circulating meteoric groundwater infiltrates and leaches Sb and W from fertile source rocks through fluid-rock interaction. Concealed granites may have solely served as a thermal source for the convection and upward migration of ore-forming fluids, while the fertility of source rocks and the intensity of fluid-rock interaction are expected to have played a crucial role in the formation of Sb-W deposits.

Respiration rates and microbiological development in yellow-dent maize seeds stored between 12% and 14% moisture content

Understanding microbial development under the typical storage conditions of maize seeds is crucial for maintaining seed quality and ensuring successful crop establishment. In this study, the respiration and microbial growth of yellow-dent maize seeds stored at 12%, 13%, and 14% moisture content (corresponding to 65%, 70%, and 75% relative humidity, respectively) and 25 °C were investigated. Two maize seed lots (hybrids KM4500 and KM4580) with different initial fungal loads were used in the experiments. To calculate the respiration rates, seeds were stored in hermetically closed jars and the oxygen and carbon dioxide concentrations were monitored for 180 days. The microbial load (colony forming units and percentage of infected seeds) was measured prior and after storage at the three humidity levels. At 65% and 70% relative humidity, respiration rates were close to zero in both seed lots, indicating minimal microbial activity. However, at 75% relative humidity, respiration rates showed a bell-shaped pattern, suggesting the onset of microbial activity in both seed lots. The seed lot with higher initial fungal load (KM4500) presented a higher respiration rate. The microbial load decreased at 65% and 70% relative humidity and the decreasing trend reverted at 75% relative humidity. This work indicates that 70% relative humidity is a safe storage moisture to prevent microbial activity at 25 °C in the studied yellow-dent maize seeds, independently of their initial fungal load. Hermetic storage, also, would make sense for seed storage only above 75% r.h. (14% m.c.) This study provides valuable insight for preserving seed quality during long-term commercial storage.

Seasonal variation in the balance and strength of cooperative and competitive behavior in patches of blue mussels.

Aggregation into groups may affect performance of individuals through the balance and strength of facilitative versus competitive interactions. We studied in situ how seasonal variation in abiotic environment affects this balance for blue mussels, a semi-sessile species. We hypothesize that seasonal variation in stresses and resources affects the strength of the interaction. We expected that, in benign conditions (here: high food availability, medium temperatures, low hydrodynamic stress), performance is dominated by growth and is better at low densities, while at adverse conditions (here: low food availability, low or high temperatures, high hydrodynamic stress), performance is dominated by survival and higher at high densities. Mussels were kept in shallow subtidal exclosures at 10 different densities for a one-month period. This exact procedure was repeated seven times at the same location within a one-year period. We measured development in mussel patch shape, performance, and environmental parameters. Environmental conditions for mussels were most benign in summer and most adverse in winter. Patches developed into less complex shapes at lower densities, but also after stronger hydrodynamic disturbances. Towards summer, mussels became more active, aggregation behavior increased, and interactions became more pronounced. Towards winter, mussels became less active: aggregation behavior and growth rates declined and at the lowest temperatures survival started to decrease with mussel density. Survival and growth (by proxy of mussel condition) were both density-dependent; however, contrary to our expectations we found positive interactions between density and survival at the most benign conditions in summer and negative interactions at the most adverse conditions in winter. In between the two seasons, the strength of the interactions increased towards summer and decreased towards winter following a bell-shaped pattern. This pattern might be explained by the environmental mediated aggregation behavior of the mussels. The obvious seasonal pattern in balance and strength of density-dependent interactions demonstrates that strength and direction of intra-specific interactions are both strongly affected by environmental context.

Biocontrol of Botrytis cinerea as Influenced by Grapevine Growth Stages and Environmental Conditions.

The growth of four commercial biocontrol agents (BCAs: Bacillus amyloliquefaciens (BAD), Aureobasidium pullulans (APD), Metschnikowia fructicola (MFN), and Trichoderma atroviride (TAS)) was evaluated using turbidimetric assays on artificial substrates mimicking the chemical berry composition at four stages: pea-sized berries, veraison, softening, and ripe berries. The response of BCA growth differed among BCAs. Subsequently, the BCAs' population size was assessed after 1 to 13 days of incubation on the substrate mimicking ripe berries at 15 to 35 °C. The population size of BAD increased with temperatures, while that of MFN decreased; the population sizes of APD and TAS showed bell-shaped patterns with lower growth at 15 or 35 °C. Finally, the BCAs were applied to ripe berries and then incubated at 15 to 30 °C. After 1 to 13 days, the berries were inoculated with B. cinerea and incubated for 7 days, after which the BCA control efficacy was assessed. The highest control was observed at 25 °C for BAD and APD, at 15 to 20 °C for MFN, and at 25 to 30 °C for TAS. The results confirm that the plant substrates and temperature affect the population size of the BCA following application; temperature also affects the preventative efficacy of BCA against B. cinerea.

Insights from analyzing local ecological knowledge and stand structure for guiding conservation actions for the endangered tropical tree Pterocarpus erinaceus. Poir

Sustainable management and conservation of multipurpose tree species in their natural habitats is crucial, given their vulnerability to climate change and increasing human activities. This can be achieved by harnessing insights from local ecological knowledge (LEK) and classical ecological approaches to support biodiversity conservation efforts. Using forest inventory data from 126 plots and information from a semi-structured survey of 234 households, we investigated LEK (perception on population trend, causes, and conservation attitudes toward the species) and population ecology (tree density, size class distribution – SCD, structural diversity, and stability) of the endangered rosewood Pterocarpus erinaceus Poir. along a climate gradient in Benin (Sudanian (SZ), Sudano-Guinean (SGZ) and Guinean (GZ)). The results indicated that local communities were aware of the decline of P. erinaceus populations, although variations were observed with respect to ethnicity and age. The protection of the species regeneration by the communities in the GZ (63 %) probably led to the high regeneration rate (90 %) of P. erinaceus in this zone. Tree density declined from the SZ to GZ (2 and 1.23 times lower in SGZ and GZ compared to SZ), but variation in the mean diameter at breast height showed the opposite pattern (1.98 and 1.90 times lower in SGZ and SZ than in GZ). The SCD in the SGZ exhibited a bell-shaped pattern, while the populations in the SZ and GZ showed an inverted J-shaped distribution. Pruning intensity was 6.60 to 35.25 times higher in the SZ than in the SGZ and GZ, respectively, where regeneration rates were low, reflecting the potential negative effects of pruning on regeneration. Furthermore, P. erinaceus demonstrated tolerance for mixed-species stands (mingling of 40 % to 75 %), indicating an opportunity to integrate it into agroforestry systems with other species. This research highlights the impacts of human activity and climate conditions on P. erinaceus populations and informs on potential management actions needed for the conservation of the species.

Comparing phenocam color indices with phenological observations of black spruce in the boreal forest

Bud phenology identifies the growing period of trees and determines the pattern of mass and energy exchanges between forest and atmosphere over time and space. Canopy color metrics derived from phenocams have been widely used to investigate tree phenology. However, it remains unclear which color-based index better tracks the seasonal variations of tree phenology in evergreen forest ecosystems. Herein, we compared four color metrics (red chromatic coordinate (RCC), green chromatic coordinate (GCC), vegetation contrast index (VCI) and excess green index (ExG)) derived from phenocam images with bud phenological phases recorded in black spruce [Picea mariana (Mill.) B.S·P] during 2017–2020 at a boreal forest site in Quebec, Canada. Canopy redness (RCC) and greenness (GCC, ExG, and VCI) showed a bimodal and bell-shaped seasonal pattern, respectively. The phases of bud burst and bud set lasted from end-May to end-June and from mid-July to end-September, respectively. The neural network model indicated that GCC had the best predictive ability in capturing the sequential phases of bud phenology. Bud phenological phases predicted by GCC showed the highest correlation with actual bud phenological phases among four indices, with R2 above 0.9 and RMSE lower than 0.5. Overall, color indices performed better when representing bud burst than bud set. Our findings improve the efficiency and confidence of the phenocam greenness index to characterize the growing season of evergreen forests.

Zooplankton community size structure across lakes within a semi-arid landscape: the effect of temperature and salinity

AbstractBody size is a master trait controlling biological communities and ecosystem functioning. Mean population size not only depends on the size of individuals, but also on the size distribution of individuals within the population. Mean community size is additionally influenced by the composition of species (larger- or smaller-sized species). Shallow lakes within semi-arid landscapes are prone to experience large changes in temperature and salinity, which affect the zooplankton size structure. Higher temperatures are expected to result in smaller average body size, while the effect of salinity appears to depend on the range under study. Here we analyze zooplankton body size patterns across shallow lakes from the semi-arid central region of Argentina. All community size descriptors point to decreasing size and a narrow size range at higher temperatures. On the other hand, the maximum average community body size occurred at intermediate (~30 gL−1) salinity levels. The combined effect of both variables resulted in a bell-shaped pattern, with maximum community body size toward lower temperatures and intermediate salinities. Based on future temperature scenarios, one may anticipate an overall decrease in community body size. But such prediction is strongly conditioned by regional and local trends in salinity.

Assessment of OTT Parsivel2 Raindrop Fall Speed Measurements

Abstract This study was to assess the raindrop fall speed measurement capabilities of OTT Parsivel2 disdrometer through comparisons with measurements of a collocated High-speed Optical Disdrometer (HOD). Raindrop fall speed is often assumed to be terminal in relevant hydrological and meteorological applications, and generally predicted using terminal speed–raindrop size relationships obtained from laboratory observations. Nevertheless, recent field studies have revealed that other factors (e.g., wind, turbulence, raindrop oscillations, and collisions) significantly influence raindrop fall speed, necessitating accurate fall speed measurements for many applications instead of reliance on laboratory-based terminal speed predictions. Field observations in this study covered rainfall events with a variety of environmental conditions, including light, moderate, and heavy rainfall events. This study also involved rigorous laboratory experiments to faithfully identify the internal filtering and calculation algorithm of OTT Parsivel2. Our assessments revealed that, for the smaller diameter bins, Parsivel2 filters out many of the observed raindrops that fall faster than predicted terminal speeds, bringing down the mean fall speed for those size bins without observational evidence. Furthermore, Parsivel2 fall speed measurements exhibited notable artificial bell-shaped deviations from the predicted terminal speeds toward subterminal fall starting at around 1 mm diameter raindrops with peak deviations around 1.625 mm diameter bin. Such bell-shaped fall speed deviation patterns were not present in collocated HOD measurements. Assessment results along with the faithfully identified Parsivel2 algorithm are presented with discussions on implications on reported raindrop size distributions (DSD) and rainfall kinetic energy.

Biological Crust Diversity Related to Elevation and Soil Properties at Local Scale in a Montane Scrub of Ecuador

The montane shrublands of southern Ecuador represent one of the least studied ecosystems, which in the last decade have been seriously threatened by increasing wildfires, deforestation, overgrazing, and conversion to forest plantations. Our main objective was to determine, at the local scale, the diversity of species composing the biological soil crust (BSC) at three elevations (2100, 2300, and 2500 m.a.s.l.) and their possible relationships with soil physical and chemical properties in montane shrublands. For this purpose, three monitoring plots of 100 m2 were established at each elevation, and within each plot, 20 subplots were established (180 subplots sampled in total). In addition, composite soil samples were collected at a depth of 0 to 10 cm, and some physical and biochemical parameters (e.g., bulk density, texture, pH, organic matter, soil organic carbon, total nitrogen, available phosphorus, and potassium) of the soil were analyzed. The results show 35 species (23 lichens, 10 bryophytes and 2 cyanobacteria) at three elevations with a bell-shaped or hump-shaped distribution pattern. This allowed us to point out that the species richness was higher at the intermediate elevations and that the composition showed significant differences in the three elevations related to soil factors. Elevation and soil drivers may help to better chose the more suitable biological soil crust (lichen-dominated and bryophyte-dominated BSC) for the management and conservation of the montane scrub of Ecuador, which is strongly threatened by human activities.

Variation of coal quantity accumulated in the Mississippian to Pennsylvanian coal seams (Upper Silesia and Lublin Coal basins, Poland): a reflection of changes in climate and CO2 availability

Many coal seams of varied thickness and aerial extent occur in the Upper Silesia and Lublin basins within Mississippian and Pennsylvanian coal-bearing deposits. Well-documented data on coal quantity in the seams identified allows visualization of their variation within the stratigraphic succession and analysis of the time-dependent coal accumulation process. Some characteristic features of this variation were observed. Coal seams of the Mississippian age (Serpukhovian, Paralic Series), formed within a near-shore environment, most often constitute small resources. There were only two intervals of increased coal accumulation in seams of >100 million tons, in the lower and uppermost parts of the Paralic Series. Within the Pennsylvanian coal-bearing succession of terrestrial fluvio-lacustrine origin, a specific, wave-like pattern of seam resource variations and four intervals of increased coal accumulation are observed. In the Lublin Coal Basin, the Lublin Beds only, deposited during the Late Bashkirian, are coal-bearing, in which a bell-shaped pattern of seam resource variation in the stratigraphic succession is observed. The location of enhanced coal accumulation events in the stratigraphic succession suggests their repetition at ~1–4 My intervals. The characteristic features of the quantitative variation in these coal seams may be correlated with glacial-interglacial and climate humidity changes, and interpreted as a response to variable volcanogenic CO2 supply.