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1.
J Water Health ; 22(5): 923-938, 2024 May.
Article in English | MEDLINE | ID: mdl-38822470

ABSTRACT

The World Health Organization classifies leptospirosis as a significant public health concern, predominantly affecting impoverished and unsanitary regions. By using the Pensacola Bay System as a case study, this study examines the underappreciated susceptibility of developed subtropical coastal ecosystems such as the Pensacola Bay System to neglected zoonotic pathogens such as Leptospira. We analyzed 132 water samples collected over 12 months from 44 distinct locations with high levels of Escherichia coli (>410 most probable number/100 mL). Fecal indicator bacteria (FIB) concentrations were assessed using IDEXX Colilert-18 and Enterolert-18, and an analysis of water physiochemical characteristics and rainfall intensity was conducted. The LipL32 gene was used as a quantitative polymerase chain reaction (qPCR) indicator to identify the distribution of Leptospira interrogans. The results revealed 12 instances of the presence of L. interrogans at sites with high FIB over various land cover and aquatic ecosystem types. Independent of specific rainfall events, a seasonal relationship between precipitation and elevated rates of fecal bacteria and leptospirosis was found. These findings highlight qPCR's utility in identifying pathogens in aquatic environments and the widespread conditions where it can be found in natural and developed areas.


Subject(s)
Water Microbiology , Leptospirosis/microbiology , Leptospirosis/epidemiology , Leptospira/isolation & purification , Leptospira/genetics , Feces/microbiology , Leptospira interrogans/isolation & purification , Leptospira interrogans/genetics , Environmental Monitoring/methods , Rain , Seasons , Bays/microbiology , Spatio-Temporal Analysis
2.
Sci Total Environ ; 931: 172902, 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38697539

ABSTRACT

Typhoons and rainstorms (>250 mm/day) are extreme weather events changing hydrological characteristics and thus nitrogen (N) cycle in coastal waters. However, responses of N cycle to rainstorms and typhoons and their underlying mechanisms need to be elucidated. In this study, we conducted an analysis of a comparative dataset encompassing concentrations of nitrate (NO3-), ammonium (NH4+), dissolved oxygen (DO), chlorophyll a (Chl a), hydrological parameters, dual isotopic composition of NO3- (δ15N-NO3- and δ18O-NO3-) in Zhanjiang Bay during three distinct periods: the normal wet season, rainstorm, and typhoon periods. After the rainstorm, the salinity front in Zhanjiang Bay was more weakened and steadier than that during the normal wet season, mainly because onshore wind and a large amount of freshwater was inputted into the ocean surface. This weakened and steady salinity front strengthened water stratification and provided a favorable condition for phytoplankton blooms. Correspondingly, evident NO3- deficits coincided with elevated δ15N-NO3- and δ18O-NO3- values indicated that sufficient NO3- sustained phytoplankton blooms, leading to NO3- assimilation during the rainstorm period. By contrast, due to the onshore wind induced by the typhoon, the salinity front in Zhanjiang Bay was more intensified and unsteady after the typhoon than the normal wet season. The salinity front after the typhoon was unsteady enough to enhance vertical mixing in the water column. Relatively high DO concentrations suggested that enhanced vertical mixing after the typhoon support freshly organic matter decomposition and nitrification via oxygen injection from the air into the water column. In addition, NO3- deficits coincided with elevated δ15N-NO3- values and δ18O-NO3- values demonstrated the coexistence of NO3- assimilation during the typhoon period. This study suggests that the changing processes involved in NO3- cycling after typhoons and rainstorms are associated with the stability and intensity of the salinity front altered by these weather events.


Subject(s)
Bays , Cyclonic Storms , Environmental Monitoring , Nitrates , Seasons , Nitrates/analysis , China , Water Pollutants, Chemical/analysis , Rain , Phytoplankton , Nitrogen Cycle , Salinity , Seawater/chemistry
3.
Environ Monit Assess ; 196(6): 507, 2024 May 04.
Article in English | MEDLINE | ID: mdl-38703253

ABSTRACT

The mangrove forest in Macajalar Bay is regarded as an important coastal ecosystem since it provides numerous ecosystem services. Despite their importance, the clearing of mangroves has been rampant and has reached critical rates. Addressing this problem and further advancing its conservation require accurate mangrove mapping. However, current spatial information related to mangroves is sparse and insufficient to understand the historical change dynamics. In this study, the synergy of 1950 vegetation maps and Landsat images was explored to provide multidecadal monitoring of mangrove forest change dynamics in Macajalar Bay, Philippines. Vegetation maps containing the 1950 mangrove extent and Landsat images were used as input data to monitor the rates of loss over 70 years. In 2020, the mangrove forest cover was estimated to be 201.73 ha, equivalent to only 61.99% of the 325.43 ha that was estimated in 1950. Between 1950 and 2020, net mangrove loss in Macajalar Bay totaled 324.29 ha. The highest clearing rates occurred between 1950 and 1990 when it recorded a total of 258.51 ha, averaging 6.46 ha/year. The original mangrove forest that existed in 1950 only represents 8.56% of the 2020 extent, suggesting that much of the old-growth mangrove had been cleared before 2000 and the existing mangrove forest is mainly composed of secondary mangrove forest stands. Across Macajalar Bay, intensified clearing that happened between 1950 and 1990 has been driven by large-scale aquaculture developments. Mangrove gains on the other hand were evident and have increased the total extent by 79.84 ha since 2000 as a result of several afforestation programs. However, approximately half of these gains that were observed since 2010 exhibited low canopy cover. As of writing, approximately 85% of the 2020 mangrove forest stands fall outside the 1950 original mangrove extent. Examining the viability of the original mangrove forest for mangrove reforestation together with promoting site-species matching, and biophysical assessment are necessary undertakings to advance current mangrove conservation initiatives in Macajalar Bay.


Subject(s)
Conservation of Natural Resources , Environmental Monitoring , Geographic Information Systems , Remote Sensing Technology , Wetlands , Philippines , Bays , Ecosystem
4.
An Acad Bras Cienc ; 96(2): e20230846, 2024.
Article in English | MEDLINE | ID: mdl-38808877

ABSTRACT

Sound speed profiles in the ocean are determined by seawater properties, where horizontal variability of thermal stratification modulates sonar detection distance. This work assesses the impacts of upwelling dynamics on sound speed profile in enclosed coastal areas by means of temperature observations acquired with a low-cost platform in Anjos Cove, Cabo Frio, Brazil. The Integrated Acquisition System for Research in Acoustics (IARA) consists of a customized 10-meter-long chain of smart temperature sensors (±0.1°C accuracy) mounted in an anchored vertical cable and an echo sounder for tide level measurements. From 2021 to 2023 a number of intrusion events of the cold South Atlantic Central Water (SACW) took place along the Cabo Frio continental shelf, some of which were recorded in the inner region of the Anjos Cove by IARA. Sound speed profiles computed by applying TEOS-10 standards indicate that the sound propagation within Anjos Cove varies often, i.e., several orders of magnitude, under the influence of SACW intrusion events. The phenomenon reflects information from deeper waters on a coastal scale, even at small depths.


Subject(s)
Acoustics , Bays , Environmental Monitoring , Seawater , Sound , Brazil , Environmental Monitoring/methods , Temperature
5.
Environ Monit Assess ; 196(6): 514, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38709331

ABSTRACT

Microplastics (MPs, plastic items from 1 µm to 5 mm in size) are present in all environmental compartments. The evaluation of their concentration, fate, and spatial distribution is still a challenge for the scientific community. This concern is just debuting in developing countries, (i.e., Asia, South America, and Africa). This study deals with the MP contamination in the abiotic marine compartments of Northern Vietnam: seawater and intertidal sediments. Four sites located in the intertidal zone or near the coastline in Tonkin Bay, Vietnam were studied. A total of 16 samples (eight for each compartment) were collected in July 2020 (rainy season) and January 2021 (dry season). Anthropogenic particles (total observed fibers and fragments) were found at levels ranging from 3 to 303 particles/m3 in seawater and from 63 to 955 particles/kg dry weight in sediments. Most of these were fibers less than 300-µm long. Higher levels of seawater at the Nam Dinh site were found in the rainy season compared to the dry one. As the river flow was estimated six times higher during the rainy season than during the dry season, these results suggest the river discharge is a potential source of contamination for the coastal zone. The temporal variability was lower for the sediments than for the seawater, suggesting the long-term integration of the anthropogenic particles in this compartment. A small portion of sorted particles were analyzed by µFTIR (8.35%), and this sub-sample was only composed of fragments. Still, fragments were mostly composed of polypropylene (PP, 82%), polyethylene (PE, 9%), and polystyrene (PS, 9%). The fragment size was similar in the two studied compartments, but it was dependent on polymer types since PS fragments (140 ± 17 µm) were smaller than those made of PE (622 ± 123 µm) and PP (869 ± 905 µm). Future works should investigate the smallest fraction of MP (even nanoplastics) as well as find solutions in order to mitigate MP contamination in the marine environment.


Subject(s)
Bays , Environmental Monitoring , Geologic Sediments , Microplastics , Seawater , Water Pollutants, Chemical , Vietnam , Seawater/chemistry , Geologic Sediments/chemistry , Water Pollutants, Chemical/analysis , Microplastics/analysis
6.
Sci Rep ; 14(1): 11190, 2024 05 16.
Article in English | MEDLINE | ID: mdl-38755236

ABSTRACT

In recent years, the combined pollution of PM2.5 and O3 in China, particularly in economically developed regions such as the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), has garnered significant attention due to its potential implications. This study systematically investigated the changes of PM2.5 and O3 and their associated human health effects in the GBA, utilizing observational data spanning from 2015 to 2019. The findings revealed a spatial trend indicating a gradual decrease in PM2.5 levels from the northwest to the southeast, while the spatial distribution of MDA8 O3 demonstrated an opposing pattern to that of PM2.5. The monthly fluctuations of PM2.5 and MDA8 O3 exhibited V-shaped and M-shaped patterns, respectively. Higher MDA8 O3 concentrations were observed in autumn, followed by summer and spring. Over the five-year period, PM2.5 concentrations exhibited a general decline, with an annual reduction rate of 1.7 µg m-3/year, while MDA8 O3 concentrations displayed an annual increase of 3.2 µg m-3. Among the GBA regions, Macao, Foshan, Guangzhou, and Jiangmen demonstrated notable decreases in PM2.5, whereas Jiangmen, Zhongshan, and Guangzhou experienced substantial increases in MDA8 O3 levels. Long-term exposure to PM2.5 in 2019 was associated with 21,113 (95% CI 4968-31,048) all-cause deaths (AD), 1333 (95% CI 762-1714) cardiovascular deaths (CD), and 1424 (95% CI 0-2848) respiratory deaths (RD), respectively, reflecting declines of 27.6%, 28.0%, and 28.4%, respectively, compared to 2015. Conversely, in 2019, estimated AD, CD, and RD attributable to O3 were 16,286 (95% CI 8143-32,572), 7321 (95% CI 2440-14,155), and 6314 (95% CI 0-13,576), respectively, representing increases of 45.9%, 46.2%, and 44.2% over 2015, respectively. Taken together, these findings underscored a shifting focus in air pollution control in the GBA, emphasizing the imperative for coordinated control strategies targeting both PM2.5 and O3.


Subject(s)
Air Pollutants , Ozone , Particulate Matter , Particulate Matter/analysis , Particulate Matter/adverse effects , Humans , China/epidemiology , Air Pollutants/analysis , Air Pollutants/adverse effects , Ozone/analysis , Hong Kong/epidemiology , Air Pollution/adverse effects , Air Pollution/analysis , Environmental Exposure/adverse effects , Environmental Monitoring , Macau/epidemiology , Bays , Seasons , Cardiovascular Diseases/epidemiology
7.
BMC Microbiol ; 24(1): 162, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38730339

ABSTRACT

BACKGROUND: Coastal areas are subject to various anthropogenic and natural influences. In this study, we investigated and compared the characteristics of two coastal regions, Andhra Pradesh (AP) and Goa (GA), focusing on pollution, anthropogenic activities, and recreational impacts. We explored three main factors influencing the differences between these coastlines: The Bay of Bengal's shallower depth and lower salinity; upwelling phenomena due to the thermocline in the Arabian Sea; and high tides that can cause strong currents that transport pollutants and debris. RESULTS: The microbial diversity in GA was significantly higher than that in AP, which might be attributed to differences in temperature, soil type, and vegetation cover. 16S rRNA amplicon sequencing and bioinformatics analysis indicated the presence of diverse microbial phyla, including candidate phyla radiation (CPR). Statistical analysis, random forest regression, and supervised machine learning models classification confirm the diversity of the microbiome accurately. Furthermore, we have identified 450 cultures of heterotrophic, biotechnologically important bacteria. Some strains were identified as novel taxa based on 16S rRNA gene sequencing, showing promising potential for further study. CONCLUSION: Thus, our study provides valuable insights into the microbial diversity and pollution levels of coastal areas in AP and GA. These findings contribute to a better understanding of the impact of anthropogenic activities and climate variations on biology of coastal ecosystems and biodiversity.


Subject(s)
Bacteria , Bays , Microbiota , Phylogeny , RNA, Ribosomal, 16S , Seawater , Supervised Machine Learning , RNA, Ribosomal, 16S/genetics , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Microbiota/genetics , Seawater/microbiology , India , Bays/microbiology , Biodiversity , DNA, Bacterial/genetics , Salinity , Sequence Analysis, DNA/methods
8.
PLoS One ; 19(5): e0298410, 2024.
Article in English | MEDLINE | ID: mdl-38758951

ABSTRACT

In the context of the digital information era, the impact of "The Internet Plus," "Big Data," and other technologies on urban social development has been far beyond any preceding era, under the influence of information technology, urban agglomeration space exhibits a new layout. Based on the search engine data of eleven cities in the Guangdong-Hong Kong-Macao Greater Bay Area from 2012 to 2021, this research constructs the inter-city information network strength linkage matrix to examine the evolution characteristics of city network structure and its driving causes. The results reveal that (1) the overall information linkage strength exhibits a pattern of steadily growing the radiating effect from the leading cities of Guangdong, Shenzhen, and Hong Kong to the surrounding cities, and a closer and more balanced information linkage network is gradually built. (2) Guangzhou-Shenzhen-Hong Kong-Guangdong-Hong Kong-Macao Greater Bay Area information linkage absolute control advantage, four cities Foshan, Dongguan, Zhuhai, Macao regional hub position steadily highlighted. The entire information connection network of the urban agglomerations tends to be flat and polycentric at the same time. (3) The regional core-edge hierarchy is well established, with the four cities of Guangzhou, Dongguan, Shenzhen, and Hong Kong creating a northwest-southeast orientation. The core metropolis regions of Guangdong, Hong Kong, and Macao in the Greater Bay Area increasingly exert a radiation spreading effect to the northeast and southwest. (4) The urban economy, transportation distance, and information infrastructure have substantial effects on the information connection intensity network of urban clusters.


Subject(s)
Cities , Hong Kong , China , Humans , Macau , Bays
9.
Mar Pollut Bull ; 203: 116489, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38759463

ABSTRACT

Sansha and Luoyuan Bay are influenced by different industrial structure, but the sources and pollution status of polycyclic aromatic hydrocarbons (PAHs), especially alkylated PAHs, are poorly understood. We studied 25 PAHs in surface sediments from the two bays. The results showed that PAHs concentrations in Sansha and Luoyuan Bay sediment range from 6.54 to 479.28 ng/g and 118.82 to 2984.09 ng/g, respectively. Alkylated PAHs dominated in Sansha (48.86 % of Σ25PAHs), while 3-ring PAHs dominated in Luoyuan (36.32 % of ∑25PAHs). Results of sources analysis indicated oil spills as the main PAHs source in Sansha, and domestic emissions and fossil fuel combustion in Luoyuan. Ecological risk assessment of showed low sediment risk, but in Luoyuan was higher than in Sansha. Compared with Luoyuan Bay, Sansha Bay emits less industrial pollutants, so the pollution is lower than Luoyuan Bay. Increased attention to protecting Luoyuan Bay is recommended.


Subject(s)
Bays , Environmental Monitoring , Geologic Sediments , Polycyclic Aromatic Hydrocarbons , Water Pollutants, Chemical , Polycyclic Aromatic Hydrocarbons/analysis , Geologic Sediments/chemistry , China , Water Pollutants, Chemical/analysis , Bays/chemistry , Risk Assessment , East Asian People
10.
Chemosphere ; 359: 142245, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38735498

ABSTRACT

This study aimed to evaluate the concentration, distribution, along with the environmental and human health impact of eight heavy metals-Pb, Cr, Cu, Cd, Zn, Mn, Ni, and As-on St. Martin's Island in the northeastern Bay of Bengal, and in doing so to help implement new legislations to protect the island. Focusing on the island's significance as a tourist destination, with seafood being a prominent dietary component, three sample types (sediment, seawater, and crustaceans) were selected for a comprehensive assessment, considering seasonal variations. Concentration of metals was observed to be lower than the established standards in sediment samples, but in seawater samples, Pb, Cr, Cd and Zn were higher than US-EPA values for natural marine water. The metals displayed a decreasing trend of Zn > Ni > Pb > Cu > Mn > As > Cd > Cr in crustacean samples for both seasons. Crustacean samples displayed higher metal concentrations in winter than in monsoon. Pb exceeded the maximum allowable limit for crustaceans with a concentration of about 3 and 4 mg kg-1 in monsoon and winter respectively; being more than 6-8 times the standard for Bangladesh which is only about 0.5 mg kg-1. Health indices displayed that although adults may suffer less from carcinogenic/non-carcinogenic health effects, the risks are far greater for children. For both age groups, As and Ni displayed possibilities of developing cancer. Principal Component Analysis (PCA)shed light on the sources of metals and showed that most of them were from anthropogenic sources. Overall, this study found that the quality of the environment of the island was better in comparison to previous studies made before the pandemic, and so, if the trend continues, it may lead to a better environment for the organisms around the island and help to keep the negative physiological impacts from the consumption of these organisms to a minimal.


Subject(s)
Bays , Environmental Monitoring , Islands , Metals, Heavy , Water Pollutants, Chemical , Water Pollutants, Chemical/analysis , Metals, Heavy/analysis , Animals , Humans , Bays/chemistry , Seawater/chemistry , Geologic Sediments/chemistry , Anthozoa/chemistry , India , Seasons , Metals/analysis , Seafood/analysis , Crustacea
11.
Mar Pollut Bull ; 202: 116332, 2024 May.
Article in English | MEDLINE | ID: mdl-38583220

ABSTRACT

Blast fishing is an illegal fishing method that not only affects fish populations and the marine ecosystem, but also local food security and local economy. Despite its effects, blast fishing continues to persist in many coastal regions around the world, including Todos os Santos Bay (BTS - Baia de Todos os Santos) in Northeastern Brazil. This study provides the first acoustic record of underwater explosions along this region. The acoustic data were collected between 2016 and 2018, from a boat-survey platform, using a portable system consisting of an HTI-90 min hydrophone (sensitivity of about -165 dB re 1 V/µPa) connected to a TASCAM DR-40 digital recorder (combined frequency response up to 30 kHz), recording at 7 m depth. The acoustic analysis was performed using both RAVEN 1.6 and MATLAB 2021a softwares. The results revealed a distinctive underwater explosion signal detected in the BTS, indicating evidence of blast fishing activities. The acoustic characterization of blast fishing in BTS provides crucial information on its occurrence and extent of this destructive practice worldwide.


Subject(s)
Acoustics , Bays , Conservation of Natural Resources , Fisheries , Brazil , Animals , Fishes , Environmental Monitoring , Explosions , Ecosystem
12.
Mar Pollut Bull ; 202: 116353, 2024 May.
Article in English | MEDLINE | ID: mdl-38598929

ABSTRACT

Galaxolide (HHCB) and tonalide (AHTN) are dominant musks added to personal care products. However, the accumulate and trophic transfer of SMs through the marine food chain are unclear. In this study, organisms were collected from three bays in Bohai Sea to investigate the bioaccumulation, trophic transfer, and health risk of SMs. The HHCB and AHTN concentrations in the muscles range from 2.75 to 365.40 µg/g lw and 1.04-4.94 µg/g lw, respectively. The median HHCB concentrations in muscles were the highest in Bohai Bay, followed by Laizhou Bay and Liaodong Bay, consistent with the HHCB concentrations in sediments. The different fish tissues from Bohai Bay were analyzed, and the HHCB and AHTN concentrations followed the heart > liver > gill > muscles. The trophic magnification factors (TMF) were lower than 1 and the health risk assessment showed no adverse health effects. The results provide insights into the bioaccumulation and trophic transfer behavior of SMs in marine environments.


Subject(s)
Environmental Monitoring , Fishes , Food Chain , Water Pollutants, Chemical , Risk Assessment , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/metabolism , Animals , Fishes/metabolism , China , Bioaccumulation , Benzopyrans , Fatty Acids, Monounsaturated/analysis , Fatty Acids, Monounsaturated/metabolism , Tetrahydronaphthalenes/analysis , Bays
13.
Environ Sci Pollut Res Int ; 31(22): 31787-31805, 2024 May.
Article in English | MEDLINE | ID: mdl-38639903

ABSTRACT

The coastal ocean receives nutrient pollutants from various sources, such as aerosols, municipal sewage, industrial effluents and groundwater discharge, with variable concentrations and stoichiometric ratios. The objective of this study is to examine the response of phytoplankton to these pollutants in the coastal water under silicate-rich and silicate-poor coastal waters. In order to achieve this, a microcosm experiment was conducted by adding the pollutants from various sources to the coastal waters during November and January, when the water column physicochemical characteristics are different. Low salinity and high silicate concentration were observed during November due to the influence of river discharge contrasting to that observed during January. Among the various sources of pollutants used, aerosols and industrial effluents did not contribute silicate whereas groundwater and municipal sewage contained high concentrations of silicate along with nitrate and phosphate during both the study periods. During November, an increase in phytoplankton biomass was noticed in all pollutant-added samples, except municipal sewage, due to the limitation of growth by nitrate. On the other hand, an increase in biomass and abundance of phytoplankton was observed in all pollutant-added samples, except for aerosol, during January. Increase in phytoplankton abundance associated with decrease in biomass was observed in aerosol-added sample due to co-limitation of silicate and phosphate during January. A significant response of Thalassiothrix sp. was observed for industrial effluent-added sample during November, whereas Chaetoceros sp. and Skeletonema sp. increased significantly during January. Higher increase in phytoplankton biomass was observed during November associated with higher availability of silicate in the coastal waters in January. Interestingly, an increase in the contribution of dinoflagellates was observed during January associated with low silicate in the coastal waters, suggesting that the concentration of silicate in the coastal waters determines the response of the phytoplankton group to pollutant inputs. This study suggested that silicate concentration in the coastal waters must be considered, in addition to the coastal currents, while computing dilution factors for the release of pollutants to the coastal ocean to avoid occurrence of unwanted phytoplankton blooms.


Subject(s)
Bays , Environmental Monitoring , Phytoplankton , Seawater/chemistry , Water Pollutants, Chemical/analysis , Nitrates/analysis , Biomass
14.
PLoS One ; 19(4): e0300326, 2024.
Article in English | MEDLINE | ID: mdl-38626003

ABSTRACT

This study aimed to reduce the risk of graft occlusion by evaluating the two-phase flow of blood and LDL nanoparticles in coronary artery grafts. The study considered blood as an incompressible Newtonian fluid, with the addition of LDL nanoparticles, and the artery wall as a porous medium. Two scenarios were compared, with constant inlet velocity (CIV) and other with pulsatile inlet velocity (PIV), with LDL nanoparticles experiencing drag, wall-induced lift, and induced Saffman lift forces, or drag force only. The study also evaluated the concentration polarization of LDLs (CP of LDLs) near the walls, by considering the artery wall with and without permeation. To model LDL nanoparticles, the study randomly injected 100, 500, and 1000 nanoparticles in three release states at each time step, using different geometries. Numerical simulations were performed using COMSOL software, and the results were presented as relative collision of nanoparticles to the walls in tables, diagrams, and shear stress contours. The study found that a graft implantation angle of 15° had the most desirable conditions compared to larger angles, in terms of nanoparticle collision with surfaces and occlusion. The nanoparticle release modes behaved similarly in terms of collision with the surfaces. A difference was observed between CIV and PIV. Saffman lift and wall-induced lift forces having no effect, possibly due to the assumption of a porous artery wall and perpendicular outlet flow. In case of permeable artery walls, relative collision of particles with the graft wall was larger, suggesting the effect of CP of LDLs.


Subject(s)
Bays , Coronary Vessels , Computer Simulation , Porosity , Models, Cardiovascular , Blood Flow Velocity , Stress, Mechanical
15.
Water Sci Technol ; 89(7): 1757-1770, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38619901

ABSTRACT

The water reuse facilities of industrial parks face the challenge of managing a growing variety of wastewater sources as their inlet water. Typically, this clustering outcome is designed by engineers with extensive expertise. This paper presents an innovative application of unsupervised learning methods to classify inlet water in Chinese water reuse stations, aiming to reduce reliance on engineer experience. The concept of 'water quality distance' was incorporated into three unsupervised learning clustering algorithms (K-means, DBSCAN, and AGNES), which were validated through six case studies. Of the six cases, three were employed to illustrate the feasibility of the unsupervised learning clustering algorithm. The results indicated that the clustering algorithm exhibited greater stability and excellence compared to both artificial clustering and ChatGPT-based clustering. The remaining three cases were utilized to showcase the reliability of the three clustering algorithms. The findings revealed that the AGNES algorithm demonstrated superior potential application ability. The average purity in six cases of K-means, DBSCAN, and AGNES were 0.947, 0.852, and 0.955, respectively.


Subject(s)
Bays , Unsupervised Machine Learning , Reproducibility of Results , Algorithms , Cluster Analysis
16.
Mar Environ Res ; 197: 106480, 2024 May.
Article in English | MEDLINE | ID: mdl-38564848

ABSTRACT

Impacts of river discharge on coastal ocean processes are multi-dimensional. Studies on sinking particle fluxes, composition and their seasonal variability in coastal oceans are very limited. In this study, we investigated the impact of river discharge on seasonal variability in sinking fluxes of total mass, biogenic and lithogenic material in a river-dominated continental margin, western coastal Bay of Bengal. Higher POC, lithogenic and total mass fluxes were found during early southwest monsoon, and are decoupled with peak river discharge and elevated primary production. It is attributed to cross-shelf transport of re-suspended surface sediments from shelf region. Peak river discharge followed by elevated chlorophyll-a suggest nutrients supply though river discharge support primary production. Elemental C:N ratios, δ13C and δ15N results likely suggest that both marine and terrestrial sources contributed to sinking POM, . Overall, higher sinking fluxes during southwest monsoon than rest of the year suggest that seasonal river discharge exerts considerable impact on sinking fluxes in the western coastal Bay of Bengal.


Subject(s)
Bays , Particulate Matter , Environmental Monitoring/methods , Geologic Sediments , Rivers , Carbon/analysis
17.
Mar Environ Res ; 197: 106470, 2024 May.
Article in English | MEDLINE | ID: mdl-38574497

ABSTRACT

In this study, the pollution status of antibiotics and ARGs in sediments from the land-sea intersection of Liaodong Bay was analyzed. The results showed that the level of antibiotic pollution ranged from ND to 433.27 ng/kg, with quinolones and tetracycline as the dominant antibiotics. The relative abundance of ARGs ranged from 3.62 × 10-3 to 1.32 × 10-1 copies/16SrRNA copies, with aminoglycoside and MLSB resistance genes being dominant. Regarding spatial distribution, the land and estuary areas showed higher antibiotic pollution levels than the offshore areas. Similarly, the land and estuary areas exhibited higher antibiotic diversity than the offshore areas. The ARGs were widely distributed on land, and their abundance gradually decreased to the downstream estuary area. Land and coastal areas exhibited higher ARG diversity than estuary areas. Analysis of environmental factors revealed a significant correlation between ARGs and non-corresponding antibiotics, and some ARGs were affected by heavy metals Cu and Pb.


Subject(s)
Anti-Bacterial Agents , Bays , Genes, Bacterial , Environmental Monitoring/methods , China , Drug Resistance, Microbial/genetics
18.
PLoS One ; 19(4): e0298237, 2024.
Article in English | MEDLINE | ID: mdl-38635689

ABSTRACT

Fungi are among key actors in the biogeochemical processes occurring in mangrove ecosystems. In this study, we investigated the changes of fungal communities in selected mangrove species by exploring differences in diversity, structure and the degree of ecological rearrangement occurring within the rhizospheres of four mangrove species (Sonneratia alba, Rhizophora mucronata, Ceriops tagal and Avicennia marina) at Gazi Bay and Mida Creek in Kenya. Alpha diversity investigation revealed that there were no significant differences in species diversity between the same mangrove species in the different sites. Rather, significant differences were observed in fungal richness for some of the mangrove species. Chemical parameters of the mangrove sediment significantly correlated with fungal alpha diversity and inversely with richness. The fungal community structure was significantly differentiated by mangrove species, geographical location and chemical parameters. Taxonomic analysis revealed that 96% of the amplicon sequence variants belonged to the Phylum Ascomycota, followed by Basidiomycota (3%). Predictive FUNGuild and co-occurrence network analysis revealed that the fungal communities in Gazi Bay were metabolically more diverse compared to those of Mida Creek. Overall, our results demonstrate that anthropogenic activities influenced fungal richness, community assembly and their potential ecological functions in the mangrove ecosystems investigated.


Subject(s)
Ecosystem , Mycobiome , Rhizosphere , Kenya , Bays
19.
Dis Aquat Organ ; 158: 75-80, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38661139

ABSTRACT

In Great Bay Estuary, New Hampshire, USA, Haplosporidium nelsoni and Perkinsus marinus are 2 active pathogens of the eastern oyster Crassostrea virginica (Gmelin), that cause MSX (multinucleated sphere with unknown affinity 'X') and dermo mortalities, respectively. Whereas studies have quantified infection intensities in oyster populations and determined whether these parasites exist in certain planktonic organisms, no studies thus far have examined both infectious agents simultaneously in water associated with areas that do and do not have oyster populations. As in other estuaries, both organisms are present in estuarine waters throughout the Bay, especially during June through November, when oysters are most active. Waters associated with oyster habitats had higher, more variable DNA concentrations from these pathogenic organisms than waters at a non-oyster site. This finding allows for enhanced understanding of disease-causing organisms in New England estuaries, where oyster restoration is a priority.


Subject(s)
Alveolata , Estuaries , Haplosporida , Animals , Haplosporida/physiology , New Hampshire , Alveolata/isolation & purification , Crassostrea/parasitology , Bays
20.
Sci Rep ; 14(1): 7785, 2024 04 02.
Article in English | MEDLINE | ID: mdl-38565615

ABSTRACT

The golden coral Savalia savaglia is a long-living ecosystem engineer of Mediterranean circalittoral assemblages, able to induce necrosis of gorgonians' and black corals' coenenchyme and grow on their cleaned organic skeleton. Despite its rarity, in Boka Kotorska Bay (Montenegro) a shallow population of more than 1000 colonies was recorded close to underwater freshwater springs, which create very peculiar environmental conditions. In this context, the species was extremely abundant at two sites, while gorgonians were rare. The abundance and size of S. savaglia colonies and the diversity of the entire benthic assemblage were investigated by photographic sampling in a depth range of 0-35 m. Several living fragments of S. savaglia spread on the sea floor and small settled colonies (< 5 cm high) suggested a high incidence of asexual reproduction and a non-parasitic behaviour of this population. This was confirmed by studying thin sections of the basal portion of the trunk where the central core, generally represented by the remains of the gorgonian host skeleton, was lacking. The S. savaglia population of Boka Kotorska Bay forms the unique Mediterranean assemblage of the species deserving the definition of animal forest. Recently, temporary mitigation measures for anthropogenic impact were issued by the Government of Montenegro. Nevertheless, due to the importance of the sites the establishment of a permanent Marine Protected Area is strongly recommended.


Subject(s)
Anthozoa , Ecosystem , Animals , Montenegro , Bays , Mediterranean Sea
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