Analysis Of Distribution Research Articles

Spatial Distribution, Pollution Assessment, and Source Analysis of Soil Heavy Metals Under Different Land Use Types in the Southern Area of Laizhou Bay

To ascertain the status of the surface soil heavy metal pollution in the southern area of Laizhou Bay, 263 surface soil samples were collected from seven different land use types in the study area and the contents and pH of eight soil heavy metals （As, Cr, Ni, Cu, Zn, Cd, Pb, and Hg） were determined. The pollution assessment was carried out using the geo-accumulation index method, Nemerow comprehensive index method, and potential ecological risk index method. Then, the source of heavy metal pollution was discussed using correlation analysis and the source analysis was carried out through positive matrix factorization （PMF）. The results showed that the surface soil in the study area was weakly alkaline； As, Ni, Zn, and Hg slightly exceeded the background values of Weifang and the spatial distribution of heavy metals showed a trend of low in the north and high in the south. The results of the geo-accumulation index indicated that the study area was pollution free and the geo-accumulation index of different land types was arranged in the order of As>Ni>Zn>Cr>Pb>Hg>Cu>Cd. The results of the Nemerow comprehensive pollution index indicated that the study area was lightly polluted and the Nemerow comprehensive pollution index of different land types was arranged in the order of town>grassland>forest>agricultural land>vegetable land>industrial land>mudflat. The results of the potential ecological risk index indicated that the study area belonged to low ecological risk and the potential ecological risk index of different land types was arranged in the order of agricultural land>town>forest land>grassland>vegetable land>industrial land>mudflat. The results of PMF analysis indicated that the heavy metal pollution sources in the study area mainly included natural sources, transportation sources, agricultural sources, and industrial sources, with contribution rates of 38.06%, 26.38%, 26.21%, and 9.35%, respectively.

Effect of Sintering Temperature on Microstructure and Properties of Zirconia Ceramics for the Needs of Nuclear Energy

The paper provides experimental results of obtaining high-density ZrO2+3%Y2O3 ceramics, which is promising for use as a matrix for immobilization of HLW. The effect of sintering temperature in the range of 1100...1650 °C on the microstructure of the sintered tablets was studied. Phase composition and microstructure of experimental samples were characterized by XRD and SEM. Grain size distribution analysis was carried out using the "Thixomet" image analyzer. Microhardness was determined using a metallographic complex LECO (USA), an inverted microscope IM-3MET and a hardness tester UIT HVB-30. It was established that increase in the sintering temperature leads to a significant increase in the average grain size (from 85 nm to 1000 nm) and increase in the density of the sintered tablets. Sintering temperature should be at least 1550...1650 ºС to produce high-dense ceramics (97...98 % of theoretical value). Obtained ceramics is characterized by high values of microhardness HV > 12 GPa and crack resistance of 5.5...6.3 MPa·m1/2.

Parents' Perception of the Role of Sports in Supporting Psychological and Social Development in Children with Specific Learning Disorders.

This study aims to examine parents' perceptions of how coach support influences the satisfaction of basic psychological needs (autonomy, competence, and relatedness) and its subsequent impact on the self-esteem and overall well-being of children with Specific Learning Disorders (SLDs) through participation in sports. The sample consisted of 1146 parents of children and young people diagnosed with SLDs from several European countries. The Coach Support Scale (COS), the Basic Psychological Needs Satisfaction Scale (BPNS), the Rosenberg Self-Esteem Scale (RSES), and the Sport Impact Scale (SIS) were used. Descriptive, reliability, Gaussian distribution, and ANOVA analyses were conducted. The results show that increased sports participation is associated with higher perceptions of coach support, autonomy, competence, psychological need satisfaction, self-esteem, relatedness, and the positive impact of sports on the lives of children and adolescents with SLDs. Children and teenagers who engage in individual and team sports exhibit greater coach support, autonomy, competence, relatedness, BPNS, and self-esteem compared to those who participate in only one type of sport, with p-values ranging from 0.004 to 0.050. In conclusion, participation in sports seems to benefit the self-esteem and well-being of children and young people with SLDs. The practical applications of this study highlight the importance of specialized coach training to address the psychological needs of children with SLDs, the development of balanced sports programs that integrate individual and team activities to optimize benefits, the encouragement of parental involvement to enhance positive experiences, and the implementation of policies that support inclusive and adaptive sports practices.

Debittering and Improving Flavour of Enzymatic Soy Protein Hydrolysate Using the Maillard Reaction of Arabinose

ABSTRACTThe optimum reaction conditions (temperature 95°C, pH 6.5, time 70 min and cysteine 0.2 g) and significant influence factors were found by response surface model (RSM) experimentation to reduce bitterness and increase overall acceptability of soybean protein hydrolysate (SPH) using the Maillard reaction of arabinose. Three reaction products of different response values and sensory profiles were selected to be investigated further. Fourier transform infrared (FTIR) spectra and UV 294 and 420 nm analyses revealed their different extents of the Maillard reaction. Partial least squares regression analysis (PLSR) for free amino acids and molecular weight distribution and aroma compounds versus the used reaction conditions of the three samples suggested that reaction conditions of higher pH plus less Cys could cause more bitter amino acids (Leu, Val) and 500–1000 Da peptides, while those of more cysteine plus longer times under low temperatures benefitted formation of the umami amino acid of glutamic acid and > 1000 Da peptides. In particular, the reaction conditions of higher temperatures and more cysteine would generate more volatile compounds with roasted and meaty aromas unfavourable for overall acceptability. Furthermore, Pearson coefficient analysis revealed the key taste and aroma components and exposed that the fatty and caramel aromas contributed positively to overall acceptability. This study can provide references for debittering and improving the flavour of SPH.

Spatial Metabolomics Reveals the Effects of Dietary Capsaicin Intervention on Interscapular Adipose Tissue Metabolome in Mice.

Capsaicin is a polyphenol with a well-known anti-obesity potential, which could activate brown adipose tissue and promote the browning of white adipose tissue. Indeed, conventional proteomics have been used to investigate the browning effects of capsaicin on adipose tissue. However, the existence of a layer of white adipose tissue above the interscapular brown adipose tissue poses a great challenge to obtain intact interscapular brown adipose tissue without including adjacent white adipose tissue. Therefore, the traditional method normally focuses on changes occurring in the bottom layer of interscapular brown adipose tissue. Spatial metabolomics is an omics method that enables the analysis of metabolite distributions in tissue sections. Therefore, in the current study, spatial metabolomics was utilized to investigate the effects of dietary capsaicin intervention on interscapular brown adipose tissue and adjacent white adipose tissue. The results indicated several noteworthy findings that capsaicin treatment may induce similar metabolite alterations across various regions of brown adipose tissue irrespective of their proximity to WAT, while it also markedly influences the metabolites in the adjacent white adipose tissue. A KEGG pathway analysis further revealed these changes were associated with key characteristics of beige energy metabolism pathways, such as thermogenesis, glycerol phospholipid metabolism, and pentose phosphate pathway. Taken together, this study may supplement useful details to understand the mechanisms of capsaicin enhancing BAT activity and promoting WAT browning.

CO-to-H2 conversion factor and grain size distribution through the analysis of αCO–qPAH relation

Abstract The CO-to-H2 conversion factor (αCO) is expected to vary with dust abundance and grain size distribution through the efficiency of shielding gas from CO-dissociation radiation. We present a comprehensive analysis of αCO and grain size distribution for nearby galaxies, using the PAH fraction (qPAH) as an observable proxy of grain size distribution. We adopt the resolved observations at 2 kpc resolution in 42 nearby galaxies, where αCO is derived from measured metallicity and surface densities of dust and H i assuming a fixed dust-to-metals ratio. We use an analytical model for the evolution of H2 and CO, in which the evolution of grain size distribution is controlled by the dense gas fraction (η). We find that the observed level of qPAH is consistent with the diffuse-gas-dominated model (η = 0.2) where dust shattering is more efficient. Meanwhile, the slight decreasing trend of observed qPAH with metallicity is more consistent with high-η predictions, likely due to the more efficient loss of PAHs by coagulation. We discuss how grain size distribution (indicated by qPAH) and metallicity impact αCO; we however did not obtain conclusive evidence that the grain size distribution affects αCO. Observations and model predictions show similar anti-correlation between αCO and 12+log(O/H). Meanwhile, there is a considerable difference in how resolved αCO behaves with qPAH. The observed αCO has a positive correlation with qPAH, while the model-predicted αCO does not have a definite correlation with qPAH. This difference is likely due to the limitation of one-zone treatment in the model.

Comprehensive mapping of molecular cytogenetic markers in pitaya (Hylocereus undatus) and related species.

Pitaya (Hylocereus undatus; 2n=22) is an important fruit crop from the Cactaceae family, originally domesticated in Mexico and the USA, and is now widely cultivated for its nutritional benefits. It is characterized by its distinctive triangular-shaped stems and large, showy flowers, thriving in arid and semi-arid environments, particularly in hot, dry climates. However, systematic chromosomal studies, including chromosomal mapping of cytogenetic markers in pitaya, are limited, presenting challenges for its cytogenetic improvement. To address this issue, we designed oligo-barcodes specific to thirty-three chromosome regions based on the pitaya reference genome and applied them to both pitaya and cactus (Selenicerus grandifloras; 2n=22) for oligo-barcodes mapping, karyotyping, and chromosome identification. We utilized FISH technology, employing oligo, rDNA, and tandem repeat probes for chromosomal mapping, identification, and karyotyping of pitaya and related species. We successfully localized oligo-barcodes on eleven pairs of chromosomes in both pitaya and cactus, demonstrating the effectiveness of the synthesized oligo-barcodes. We used two ribosomal DNA (rDNA) probes (45S and 5S) and two tandem repeat probes (GTR11 and STR3) in pitaya (both diploid and tetraploid) and two other Cactaceae species (S. grandifloras and Opuntia humifusa; 2n=40) for chromosomal mapping. The analysis of rDNA distribution and CMA (Chromomycin A3) banding across different chromosomes in pitaya and cacti highlights the concept of conserved rDNA. This study provides fundamental insights into cytogenetic markers and their localization across different chromosomes in pitaya and other Cactaceae species.

Application of Resistance Ring Array Sensors for Oil–Water Two-Phase Flow Water Holdup Imaging in Horizontal Wells

Unconventional oil and gas reservoirs are frequently developed using inclined and horizontal wells, leading to intricate multiphase flow patterns due to spatial asymmetry surrounding the wellbore and gravitational differentiation effects. Through the examination of water holdup imaging, the spatial arrangement of oil and water phases within the wellbore may be clearly depicted, yielding critical information for precisely assessing the ratios of oil and gas. This study employed No. 10 industrial white oil and tap water as fluid media, with measurements obtained using a resistive ring array tool (RAT) to evaluate its response properties over the wellbore cross-section. The data gathered throughout the trials were analyzed by two-dimensional interpolation imaging utilizing 2020 version MATLAB software. To enhance the analysis of water holdup distribution in the wellbore, three interpolation algorithms were utilized: Simple Linear Interpolation (SLI), Inverse Distance Weighting Interpolation (IDWI), and Ordinary Kriging Interpolation (OKI). The results indicated that RAT operates effectively in medium and low flow circumstances, correctly representing the real distribution of oil and water phases while yielding more dependable water holdup data. The SLI algorithm effectively delineates the oil-water interface during stratified flow of oil and water phases, rendering it the optimal algorithm for determining water holdup in standard flow patterns. Under DW/O&W and DO/W&W flow patterns, SLI continues to perform well; however, the accuracy of IDWI and OKI markedly enhances, with IDWI more effectively delineating the attributes of intricate mixed flow and more precisely representing the dynamic fluid distribution. Under DW/O and DO/W flow patterns, the OKI algorithm exhibits optimal performance in these intricate dispersed flow patterns. OKI more precisely represents the dynamic distribution of dispersed oil and water due to its capacity to simulate the spatial correlation of both phases, surpassing both SLI and IDWI.

Inequalities in tuberculosis control in Ethiopia: A district-level distributional modelling analysis.

Implementation studies indicate that the addition of tuberculosis diagnosis and treatment services into the community health extension workers' tasks-that is 'task-shifting'-improved case detection and treatment outcomes in Ethiopia. Given resource and operational constraints, only a limited number of areas can be targeted by an expanded task-shifting program. Therefore, we mapped the distributional disparities in tuberculosis services across regions and districts and modelled the equity pathways towards optimising national scale-up of this task-shifting intervention in Ethiopia. We used data from various sources including District Health Information Software 2; demographic, geospatial and topographic data; and previously published implementation study findings. We developed methods to integrate these datasets and to calculate the proportion of health facilities with tuberculosis services, the district population to health centre ratio, and the proportion of district population living within 2h walking distance from a health centre. Equity and disparities were then measured in terms of: tuberculosis services coverage; health centre adequacy, that is the district population served by health centres; and spatial access adequacy, that is the district population with health centre access within a two-hour walking distance. Subsequently, districts were ranked according to these measures to allow prioritisation of the health extension worker task-shifting intervention. Tuberculosis services coverage varied from 54% in Afar region to 100% in Harari region, and health centre inadequacy ranged from 10% of districts in Benishangul-Gumuz to 87% in Sidama. After spatial access adjustment, health centre inadequacy ranged from 7% of districts in Sidama to 91% in Somali; and tuberculosis services inadequacy from 7% of districts in Sidama to 97% in Afar. Task-shifting implemented in inadequate districts (55% of all districts) could raise national case detection rate from 66% (currently) to 88% and treatment success rate from 93% to 99%; Benishangul-Gumuz achieving the largest increase of all regions. Access to effective tuberculosis services presents substantial disparities across districts in Ethiopia, due to both health system and tuberculosis-specific factors. Jointly considering both types of factors would enable prioritisation of districts where health extension workers would be most impactful.

New results in the CTEQ-TEA global analysis of parton distributions in the nucleon

This report summarizes the latest developments in the CTEQ-TEA global analysis of parton distribution functions (PDFs) in the nucleon. The focus is on recent NNLO fits to high-precision LHC data at 8 and 13 TeV, including Drell–Yan, jet, and top-quark pair production, pursued on the way toward the release of the new generation of CTEQ-TEA general-purpose PDFs. The report also discusses advancements in statistical and numerical methods for PDF determination and uncertainty quantification, highlighting the importance of robust and replicable uncertainties for high-stakes observables. Additionally, it covers phenomenological studies related to PDF determination, such as the interplay of experimental constraints, exploration of correlations between high-x nucleon sea and low-energy parity-violating measurements, fitted charm in the nucleon, the photon PDF in the neutron, and simultaneous SMEFT-PDF analyses.

Finite Element Analysis of Stress Distribution in Alkali-Peroxide Treated Epoxy Composites with Various Woven Cotton Structures

ABSTRACT The poor surface properties of woven epoxy-cotton composite structures have limited their use in industrial applications. Existing solutions using single treatment processes have been developed to address the challenges but have recorded appreciable degrees of success. This study has introduced a novel and synergistic alkali-peroxide treatment in addition to the use of five (5) variations of reinforcing woven structures (plain, matt, twill, herringbone, and satin) to develop the composites via the vacuum bagging molding process. This paper demonstrates the effectiveness of the dual treatment and different woven architectures in structure-related properties, particularly in the warp (machine) direction. The synergistic treatment showed a negative effect on the thermal stability of the resulting composites. The composite with the optimum weave structure in reinforcement capacity was validated using ANSYS FEA based on the numerical and experimental results, and the obtained results showed the possibility of simulating the tensile behavior of the composite structures.

Prognosis of Patients with Breast Cancer Following Delayed Diagnosis During the COVID-19 Pandemic: A Real-World Cohort Study.

The coronavirus disease 2019 (COVID-19) pandemic has globally impacted healthcare systems, delaying cancer screening, diagnosis, and treatment. South Korea experienced a 3-month lockdown during the peak of the pandemic, leading to postponements in breast cancer diagnosis and treatment. Although the pandemic's severity has decreased, addressing the treatment gap remains a concern. This retrospective cohort study included patients diagnosed with breast cancer at five academic hospitals in South Korea during the pre-COVID (May-July 2019) and COVID (May-July 2020) periods. The primary endpoint was recurrence-free survival (RFS), and secondary endpoints included overall survival (OS), stage distribution, and age subgroup analyses. Among 716 patients (374 pre-COVID, 342 COVID), the 3-year RFS was significantly lower in the COVID group (88.3 vs. 89.7%, p=0.030), while the 3-year OS was similar between groups (96.2 vs. 95.5%, p=0.439). Age subgroup analysis revealed a significant RFS difference in patients under 65 years of age (p=0.005) but not in those aged 65years and older (p=0.682). Stage distribution did not differ significantly between groups (p=0.531). The COVID-19 pandemic adversely affected 3-year RFS, especially among younger patients, despite no significant increase in advanced-stage distribution. Timely cancer screening remains crucial for young patients with fewer infectious disease complications.

Integrating data from cold-water coral habitats increase knowledge on age and growth studies: the case of Helicolenus dactylopterus (Delaroche, 1809) in the central Mediterranean

The aim of this study is to provide new insights on the age and growth of H. dactylopterus in the north-western Ionian Sea (central Mediterranean) by using different data sets and comparing three different methods, one direct by otolith reading corroborated by two indirect methods, by means of back calculation and Length Frequency Distribution analysis (LFDa), in order to obtain robust data for use in analytical management models. A total of 1403 specimens of blackbelly rosefish were sampled from habitats explored on muddy bottoms in the depth range 106-721 m and 309 individuals caught in the cold-water coral habitat between 418 and 635 m in depth. The length-frequency distributions of blackbelly rosefish showed a polymodal pattern in both habitats explored, with medium-small individuals caught on muddy bottoms and larger ones in coral habitats and canyons. The maximum age observed in females was 13 years (315 mm TL), while in males it was 15 years (336 mm TL), and no significant difference was observed comparing age-length keys from otolith readings of females with the males. The analysis of the daily increments allowed us to validate the average length of the first year of age (approximately 90-100 mm LT) obtained from the three different methods used. No significant difference was highlighted comparing the average lengths of age class 1, calculated with the direct method and by counting the daily increments. The von Bertalanffy growth parameters were estimated for the sexes and for the whole population from otolith readings and for the entire population by LFD analysis and the back calculation method. The growth curves were comparable between the different methods and no significant difference was observed. The von Bertalanffy growth parameters estimated for the different methods were comparable (otolith readings L∞ 494 mm, k=0.06 years-1, t0=-3.00 years; back calculation method L∞ 487 mm, k=0.06 years-1, t0=-2.30 years; LFDa L∞ 415 mm, k=0.07 years-1, t0=-2.23 years), indicating a slow growth in accordance with what has already been observed in other areas of the Mediterranean.

Turbine performance and wind energy potential using probability distribution in Africa

The energy requirement in the world is increasing day by day. The non-renewable energy production is one of the reasons for climate change. The present study explores the selection of possible locations to establish a wind power plant in Ethiopia. The possible locations from Ethiopia that were considered in this study are Weraelu, Enewari and Mekdela. The wind speed characterization, wind direction and wind power densities were analyzed at Waraelu, Enewari and Mekdela. The results of this study reveals that Enewari is the best suitable place to establish the wind power plants among Waraelu, Enewari and Mekdela. In Enewari site the maximum wind speed at 10m height is 6.11 m/s. 75% of wind direction at Enewari site is from North to North West and North to North East. Weibull distribution analysis was incorporated to find average wind speed and probability density among five years of wind speed data. The average wind speed and probability density over five years of Enewari site is 5 m/s and 18.5%. The wind power densities were determined by Weibull method and the maximum wind power obtained from Enewari site is 495.33 w/m^2.

Grooved single-channel dual media tank thermal energy storage systems to improve overall thermal performance: Numerical analysis

In this study, a numerical analysis of a single-channel structured dual media tank (DMT) thermal energy storage (TES) system is done to investigate the effect of grooves on thermo-hydraulic performance. Due to computational complexity, a single channel is considered, and results are validated by the numerical results of other studies. The study encompasses the analysis of unsteady temperature distribution, heat transfer coefficient, and friction factor by varying the groove size ratio with the diameter of the pebbles. The φ ratio (grooves diameter/pebbles diameter) is varied from 3.15 to 4.73, and the effect of the Re for different widths of the channel is studied. The numerical result reveals a 50 % increase in heat transfer coefficient when φ is varied from 3.15 to 4.73 at a Reynolds number of 22.4. Similarly, a small variation in the frictional factor can be observed. amounts to 22 % while keeping a Reynolds number of 22.4 and a diameter ratio (φ) ranging from 3.15 to 4.73. Furthermore, research is done on how Reynolds number affects volumetric heat transfer (ℎv). The results indicate a 31 % decrease in ℎv at φ = 3.15. on the other hand, a larger value of φ is observed to result in a lesser drop in ℎv. Additionally, the computation performance improvement factor (PEF) shows greater values for φ = 3.15, indicating that the ideal groove diameter to achieve maximum heat transfer rate and minimum pressure drop is smaller.

Enhancing Plasma Torch Efficiency: Wet Steam Cooling

The efficient use of wet steam for plasma torch cooling and water plasma generation is important for reliable plasma generator design. Wet steam, due to phase transformation capability, improves heat removal at lower gas flow rates if compared to liquid water. To evaluate the wet steam cooling potential, a numerical model is proposed, incorporating governing equations (mass, momentum, energy, current, and Ampere's law) are expressed in the cylindrical coordinate system. The model is applied to investigate the wet steam cooling feasibility for the anode of a direct current plasma torch with non-transferred arc. Electric arc modeling examines anode spot location and anode surface temperature distribution for a 120 A arc current and gas flow rates of 42, 90, and 140 l/min under steady flow conditions. Analysis of spatial vapor content distribution in the refrigeration channel highlights unfavorable conditions when wet steam becomes dry.

Mechanism to disrupt ESCRT-mediated intracellular trafficking through Vps28-small molecules interaction: an in silico approach

The ESCRT (Endosomal Sorting Complex Required for Transport) machinery comprising protein complexes ESCRT-0 to ESCRT-III and Vps4 plays a pivotal role in intracellular trafficking, a process of endocytosing cell surface proteins into the cell for various biological activities. The ESCRT protein complexes are sequentially assembled which interact amongst each other to form a functional ESCRT machinery. Deregulation of these events are shown to be involved in various disease development including tumor formation and viral infections. Recently upregulation of a crucial ESCRT protein, Vps28 has been shown to be implicated in tumor formation. However, Vps28 in ESCRT-I interacts with Vps36 in ESCRT-II to function as a connecting protein during ESCRT machinery formation. Until now biomolecular approaches to inhibit the formation/assembly of ESCRT machinery have not been developed. Hence, we hypothesized that disrupting Vps28/Vps36 interaction would prevent assembly of ESCRT machinery and offer therapeutic potential to restrict disease development and progression. To address this, we utilized a virtual screening approach using a flavonoid-based library to identify potential small molecule inhibitors that can bind to Vps28 active site. Based on the binding affinity, top-hit compounds were identified. Molecular dynamics simulations set over a 500 ns timescale demonstrated the stability of the Vps28-small molecule complexes. Per-residue decomposition analysis using Molecular Mechanics/Poisson–Boltzmann surface area highlighted the significant contributions of active site residues Asn189, Arg190, Arg193 and Asn210 in Vps28 for interaction with small molecules. Absorption, Distribution, Metabolism, Excretion, and Toxicity analysis for toxicity evaluation indicates that molecules Z0131, H0194, Z0199 and DQ00112 exhibited physicochemical properties suitable for drug development.

Geography, Antimicrobial Resistance, and Genomics of Salmonella enterica (Serotypes Newport and Anatum) from Meat in Mexico (2021-2023).

Salmonella enterica non-typhoidal is a major contributor to diarrheal diseases, with over 2600 serovars identified across diverse environments. In Mexico, serovars Newport and Anatum have shown a marked increase, especially in foodborne disease, posing a public health problem. We conducted a cross-sectional study from 2021 to 2023 using active epidemiological surveillance to assess contamination in ground beef and pork at butcher shops nationwide. It involved isolation, phenotypic antimicrobial resistance, comparative genomics, spatial distribution, antimicrobial-resistance genes, and pangenome analysis. A total of 402 non-typhoidal S. enterica strains were isolated, including 59 Newport and 50 Anatum. After curating for redundancy, 45 Newport and 32 Anatum strains remained. We found that 75% of Newport strains exhibited multidrug resistance (MDR), compared to 25% of Anatum strains. Salmonella Newport also showed a broader distribution and stronger antibiotic-resistance capacity, particularly due to genes such as mphA and ramA. Our pangenome analysis showed a predominance of cell maintenance and survival-process genes in the accessory genome of both serotypes. Considering unique genes, Salmonella Anatum and Newport showed a notorious abundance of genes with functions related to replication, recombination, and repair. The substantial rise of Anatum and Newport strains in meat samples for human consumption presents an epidemiological alert, highlighting the critical need for stringent surveillance programs to mitigate human and ecosystem health risks.

Spatial Distribution, Risk Assessment and Source Analysis of Heavy Metals in the Sediments of Jinmucuo Lake, Southern Tibetan Plateau

Sediments serve as a crucial accumulation site for pollutants, and the source and sink effects of sediment pollutants significantly influence the overlying water. In this research, the concentrations of heavy metals in the sediments of Jinmucuo Lake were investigated. The pollution levels and ecological risks of the heavy metals were assessed via the geoaccumulation index and potential ecological risk index, and the potential sources were identified via multivariate statistical methods. Results revealed that the mean concentrations of cadmium, chromium, copper, zinc, nickel, arsenic and mercury exceeded the soil background values in Tibet, and each element generally tended to increase with decreasing depth in the sediment cores. Heavy metals were mainly distributed in the estuaries of the western part of the lake. Moreover, the geoaccumulation index revealed that mercury pollution was severe, followed by nickel and copper. The potential ecological risk index revealed that Jinmucuo Lake was a highly strong ecological risk and that mercury was the most important ecological risk factor. Multivariate statistical analysis indicated that chromium and nickel pollution was influenced by natural factors and anthropogenic activities, while geothermal activity, river inputs and atmospheric transmission were the main sources of mercury and arsenic. Moreover, cadmium, lead, copper and zinc pollution was mainly affected by transportation and high background values. The results provide an important reference for the ecological and environmental protection of Jinmucuo Lake.

Spatial distribution and structural analysis of the Neogene Siroua volcanic field (Moroccan Atlas Mountains)

Monogenetic volcanic fields develop worldwide in different geodynamic settings, and understanding their evolution may provide crustal, thermal, and topographical constraints. We focus on the small monogenetic Siroua volcanic field that has formed since the late Miocene along the tectonic lineament separating the High Atlas and the Anti-Atlas Mountains of Morocco, though the evolution of which is still unclear. We investigate the formation and evolution of the Siroua monogenetic field using geostatistical methods that allow us to classify the spatial distribution of vents in their geological contexts. In addition, we use aeromagnetism to obtain information about the tectonic structures underlying the field. Each method is evaluated separately, and then combined to discuss the relationship between the volcanism and the tectonic framework at regional and local scales. Our findings indicate that although vents are broadly randomly distributed, some correlation between volcanic alignments and the structural framework is locally observed. These findings corroborate existing knowledge about the influence of pre-existing structures on the propagation of magmas and on the spatial distribution of volcanic vents within monogenetic volcanic fields.