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1.
Sci Total Environ ; 906: 167362, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37769734

RESUMO

This study focuses on the performance and clogging of vertical flow constructed wetlands (VFCWs) planted with climbing ornamentals and ornamental plants for greywater treatment, after two years of operation at mesocosm level. Different substrate (sand, vermiculite) and vegetation (Trachelospermum jasminoides, Lonicera japonica, Callistemon laevis) types were evaluated to determine the optimal removal of pollutants. Results revealed that, during the second year of operation, removal efficiencies of turbidity and COD were significantly higher (1st year: 54-94 %; 71-89 %, 2nd year: 82-98 %; 86-95 %, respectively) for both studied planted substrates, compared to the first year. Moreover, it was found that sand systems from each studied plant as well as from the unplanted systems, were more effective compared to vermiculite for most of the studied parameters (turbidity, TSS, COD, anionic surfactants, pathogens). Sand systems were also quite effective in removing total coliforms (5 log reduction) and Escherichia coli (4 log reduction). At the end of the two-year experiment, all planted systems with sand had significantly higher hydraulic conductivity than the unplanted ones. With reference to evapotranspiration, even though planted systems had significantly higher losses, C. laevis systems demonstrated less water losses than the other vegetated systems. According to the findings, the studied plants managed to continue growing without facing added stress. Therefore, the application of climbing and ornamental plants in VFCWs for greywater treatment in buildings seems a promising option for developing green infrastructures in urban areas and enhancing the removal efficiency of such systems.


Assuntos
Jardins , Eliminação de Resíduos Líquidos , Eliminação de Resíduos Líquidos/métodos , Áreas Alagadas , Areia , Plantas
2.
Sci Total Environ ; 906: 167509, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37788775

RESUMO

Soil protozoa are an essential part of the terrestrial ecosystem, playing a vital role in the global element cycling and energy flow. However, one research gap is what are the key factors driving their diversity and environmental fates. In this study, we hypothesized that soil texture could affect soil protozoa's predation and their interactions with environmental pollutants, and we tested it by using a soil amoeba Dictyostelium discoideum as a model system. We found that soil texture affected amoeba's growth and development. In addition, environmental factors cannot explain the variation of amoeba's fitness in different soil textures. Soil sandy particles and water content rather than particle size contribute to amoeba's fitness. Furthermore, different soil textures induced distinct transcriptional responses to amoebae, especially N-glycan-related and multiple signaling pathways and the expression of key genes (e.g., Ras superfamily, cxgE, trap1). The expression of N-glycan-related pathways, which is positively correlated with amoeba predation, was inhibited in sand soil, decreasing amoeba's fitness. Finally, the results showed that soil texture also affects amoeba's interaction with environmental pollutants. In conclusion, this study shows that soil physical structures affect amoeba's interactions with bacteria and environmental pollutants. SYNOPSIS: Soil texture affects soil protozoa's growth and development and their interactions with environmental pollutants.


Assuntos
Amoeba , Dictyostelium , Poluentes Ambientais , Solo , Dictyostelium/microbiologia , Dictyostelium/fisiologia , Ecossistema , Areia
3.
Sci Total Environ ; 906: 167444, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37777135

RESUMO

This study focused on understanding the influence of stormwater on sediment recontamination and biota bioaccumulation. Stormwater and sediment sampling was conducted at Paleta Creek San Diego, CA, a mixed-use urban watershed. Stormwater samples were size fractioned into clay, silt, sand, and filtered fractions to better understand the association of PAHs and PCBs with different particle sizes. Settling traps were deployed during storm seasons to capture solid particles deposited by stormwater. Bioaccumulation studies of the receiving water sediments were conducted on bent-nosed clams (Macoma nasuta) both in-situ and ex-situ. The results indicated that the majority of PAHs and PCBs were discharged during the early stages of the storm and were primarily associated with coarser particles (>20 µm). Sediment near the discharge exhibited higher levels of contaminants, consistent with the findings from the settling traps and stormwater discharges. Ex-situ bioaccumulation studies demonstrated that sediment contamination did not correlate with bioaccumulation in Macoma nasuta, whereas porewater accurately reflected bioaccumulation trends. This study highlights the importance of considering stormwater discharge patterns and particle sizes when assessing sediment recontamination but also that the resulting bulk sediment contamination may not reflect bioavailability as measured by organism bioaccumulation. These insights contribute to a better understanding of the impacts of stormwater runoff on sediment and biota in southern California coastal watersheds, aiding in the development of effective management strategies.


Assuntos
Bifenilos Policlorados , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Bifenilos Policlorados/análise , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Areia , Hidrocarbonetos Policíclicos Aromáticos/análise , Monitoramento Ambiental/métodos
4.
Sci Total Environ ; 908: 168372, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37952671

RESUMO

Vegetation has an important influence on soil temperature (ST). However, the possible effects of surface vegetation on ST and their feedback on microclimate remain uncertain due to the lack of in-situ and long-term environmental records, especially for arid and semiarid regions of the world. A continuous, two-year study was implemented over a bare sand dune (BF) and two scrub-vegetation sites of variable cover in the Mu Us Desert of northwest China. Surface vegetation at the two non-bare sites varied from about 40% (moderate cover, MF) and 80 % (high cover, HF) of their respective surface area. Depiction of the vertical ST-profile was based on an array of field-based measurements taken within the uppermost 180 cm of the soil complex at each site. Compared with the BF site, mean ST at MF and HF decreased by 1.2 and 1.6 °C during the uniform thaw period and increased by 0.1 and 1 °C during uniform freezing. Amplitude of seasonal variation in ST for both vegetated sites, i.e., MF and HF, was reduced by 2.4 and 4.9 °C, respectively. As soil cooling during the uniform thaw period was greater than soil warming during uniform freezing, annual mean ST decreased at both vegetated sites by 1.6 and 1.2 °C (for MF and HF, respectively) compared to ST at BF. Differences in ST among the three sites during the uniform freeze and thaw periods were exponentially correlated with the extent of site vegetation cover, leaf area index, aboveground biomass, and on-the-ground litter thickness. Vegetation cover was shown to reduce the depth of the frost layer by 30 cm and prolonged the uniform thaw period by 1-35 days at the HF site. Mean daily STs at the center of each soil layer at the three sites were simulated with a two-equation model developed for this study, yielding a coefficient of determination (R2) of 0.91 when modeled STs were compared against their corresponding field observations. Increases in winter ST has potential to safeguard ground-dwelling grubs and other agriculturally harmful insects from freezing and dying. Likewise, decreases in annual ST could help promote decreases in litter decomposition, potentially lessening the effects of wind erosion.


Assuntos
Areia , Solo , Temperatura , Clima , Biomassa , China
5.
Sci Total Environ ; 911: 168496, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-37996020

RESUMO

Understanding how vegetation (shrub) cover in drylands affects local-to-regional soil water dynamics and associated water balances is of immense importance because of the abundance of afforestation projects worldwide. Vegetation's role in the control of soil water presents a particular challenge to soil water storage (SWS) management in the drylands of China. To address this knowledge gap, we conducted a two-year study in the Mu Us Desert of northwest China. The study involved the acquisition of in-situ soil water measurements within the first 180 cm of soil at three sand dune sites characterized by their differences in % shrub cover. The sand dunes varied from a vegetation-free, bare-ground sand dune site (BF) and two partly vegetated sites, one with medium-level (40 %) and another with high shrub cover (80 %; MF and HF, respectively). Results revealed that the site with the high shrub cover (HF) suffered a net reduction in soil water content (SWC) by up to 32.7 and 39.8 % in the shallow and deep subsoil (0-100 and 100-180 cm), respectively, when compared to corresponding changes at the BF site. Soil water content was shown to be largely influenced by site properties, namely shrub biomass and litter density (p < 0.05). Due to aboveground vegetation and rainfall interception by the litter, 32.2 mm of effective rainfall was reduced to the soil for every 10 %-increase in shrub cover. Bands of soil water depletion during the dry year did not fully recover during the following wet year, resulting in the development of a dried soil layer with an average SWC of 4.6-7.8 %. Increased evapotranspiration (ETtotal) led to a decrease in SWS and relative extractable soil water (REW), which caused ETtotal at HF to be lower than the rate observed at MF. These findings highlight the need for improvements in current restoration strategies, meant at striking a balance between vegetation restoration and SWC by developing optimal plant-community cover and mosaicked vegetation systems.


Assuntos
Ecossistema , Solo , Areia , Água/análise , China
6.
Environ Pollut ; 340(Pt 1): 122809, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37918776

RESUMO

This work constitutes the first survey that allows the establishment of baseline levels of environmental radioactivity in beach sands from the volcanic oceanic islands of La Graciosa, Lanzarote, Fuerteventura and Gran Canaria. Activity concentration values of 226Ra, 232Th and 40K were measured by gamma spectroscopy in 108 samples, collected from 39 beaches across the whole study region. The radiological hazard risks associated with these sands were studied. The mean absorbed dose rate in the study region was 20 nGy h-1, which is below the world average value. The mean outdoor annual effective dose for the beaches studied was 0.025 mSv y-1, which is within the internationally accepted safe limit. Additionally, the assessment of the radium equivalent showed that all samples from the Eastern Canary Islands are below the safe limit of 370 Bq kg-1. Despite not posing any radiological risk to the human population, the radiological hazard indices obtained in Gran Canaria were significantly higher than those of other islands. These significant differences seem to be related to the presence of sediments in the beaches of Gran Canaria that have their origin in lithologies with higher activity concentration values of 226Ra, 232Th and 40K that are not present in the rest of the islands.


Assuntos
Areia , Humanos , Espanha , Raios gama , Medição de Risco
7.
Sci Total Environ ; 907: 167832, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37863223

RESUMO

Genotoxicity of PAH-contaminated soils can eventually increase after bioremediation due to the formation and accumulation of polar transformation products, mainly oxygenated PAHs (oxy-PAHs). Biodegradation of oxy-PAHs has been described in soils, but information on the microorganisms and mechanisms involved is still scarce. Benz(a)anthracene-7,12-dione (BaAQ), a transformation product from benz(a)anthracene frequently detected in soils, presents higher genotoxic potential than its parent PAH. Here, using sand-in-liquid microcosms we identified a specialized BaAQ-degrading subpopulation in a PAH-contaminated soil. A BaAQ-degrading microbial consortium was obtained by enrichment in sand-in-liquid cultures with BaAQ as sole carbon source, and its metagenomic analysis identified members of Sphingobium, Stenotrophomonas, Pusillimonas, Olivibacter, Pseudomonas, Achromobacter, and Hyphomicrobiales as major components. The integration of data from metabolomic and metagenomic functional gene analyses of the consortium revealed that the BaAQ metabolic pathway was initiated by Baeyer-Villiger monooxygenases (BVMOs). The presence of plasmid pANTQ-1 in the metagenomic sequences, identified in a previous multi-omic characterization of a 9,10-anthraquinone-degrading isolate recovered from the same soil, suggested the occurrence of a horizontal gene transfer event. Further metagenomic analysis of the BaAQ-degrading consortium also provided insights into the potential roles and interactions within the consortium members. Several potential auxotrophies were detected, indicating that relevant nutritional interdependencies and syntrophic associations were taking place within the community members, not only to provide suitable carbon and energy sources, but also to supply essential nutrients and cofactors. Our work confirms the essential role that BVMO may play as a detoxification mechanism to mitigate the risk posed by oxy-PAH formation during bioremediation of contaminated soils.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Consórcios Microbianos , Creosoto , Areia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Biodegradação Ambiental , Carbono , Poluentes do Solo/metabolismo , Microbiologia do Solo , Solo
8.
J Environ Manage ; 349: 119464, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37931337

RESUMO

Landfill mining is emerging as an effective strategy towards mitigation of the problems associated with legacy landfills. About 40-80% of the landfill mined waste is soil-like fraction (landfill mined soil like fraction, LMSF) that is obtained after removing the combustibles and recyclables. However, due to its lower calorific value and presence of organic content, LMSF has not found many applications except landfill cover material and filling of low-lying areas. In this context, the present study explores the strength properties of LMSF with and without fibres (coir and polypropylene fibres) through unconfined compression, direct shear, UU triaxial, cyclic UU triaxial, indirect tension and bending strength tests. Overall, the shear strength properties of LMSF are similar to sand with some cohesion. Further, the performance of LMSF with optimum fibre proportion (2% for coir fibres and 1.5% for polypropylene fibres) is quite superior under monotonic and cyclic compressive loading conditions, as well as indirect tension and flexural loading conditions. An assessment of 1 m replacement of soft soil with LMSF with/without fibre reinforcement infers substantial increase in the allowable bearing pressure of LMSF. Overall, though LMSF may need assessment/pre-treatment (as required) due to presence of organic content and any possible heavy metal concentration, utilization of LMSF would encourage the adoption of landfill mining process. The current research insights contribute in the direction of achieving sustainable infrastructure development by reduction in the landfill area that would reduce the depletion of conventionally utilized natural resources for fill applications such as sand and gravel, and contribute positively towards environment.


Assuntos
Eliminação de Resíduos , Solo , Areia , Polipropilenos , Instalações de Eliminação de Resíduos
9.
Ecotoxicol Environ Saf ; 268: 115683, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37976931

RESUMO

In marine sediments surrounding salmon aquaculture sites, organic matter (OM) enrichment has been shown to influence resident bacterial community composition; however, additional effects on these communities due to combined use of the sea-lice therapeutant emamectin benzoate (EMB) and the widely used antibiotic oxytetracycline (OTC) are unknown. Here, we use sediment microcosms to assess the influence of OM, EMB, and OTC on benthic bacterial communities. Microcosms consisted of mud or sand sediments enriched with OM (fish and feed wastes) and spiked with EMB and OTC at environmentally-relevant concentrations. Samples were collected from initial matrices at the initiation of the trial and after 110 days for 16 S rRNA gene sequencing of the V3-V4 region and microbiome profiling. The addition of OM in both mud and sand sediments reduced alpha diversities; for example, an average of 1106 amplicon sequence variants (ASVs) were detected in mud with no OM addition, while only 729 and 596 ASVs were detected in mud with low OM and high OM, respectively. Sediments enriched with OM had higher relative abundances of Spirochaetota, Firmicutes, and Bacteroidota. For instance, Spirochaetota were detected in sediments with no OM with a relative abundance range of 0.01-1.2%, while in sediments enriched with OM relative abundance varied from 0.16% to 26.1%. In contrast, the addition of EMB (60 ng/g) or OTC (150 ng/g) did not result in distinct taxonomic shifts in the bacterial communities compared to un-spiked sediments during the timeline of this experiment. EMB and OTC concentrations may have been below effective inhibitor concentrations for taxa in these communities; further work should explore gene content and the presence of antibiotic resistance genes (ARGs) in sediment-dwelling bacteria.


Assuntos
Oxitetraciclina , Animais , Oxitetraciclina/análise , Areia , Antibacterianos , Sedimentos Geológicos/microbiologia , Bactérias/genética
10.
PLoS One ; 18(11): e0289847, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38032923

RESUMO

This study takes the aeolian sand concrete as a research object, uses the relative dynamic elastic modulus to study its macro characteristics, and combines nuclear magnetic resonance、scanning electron microscope to study its pore characteristics and micro morphology under the action of prestress, freeze-thaw and salt intrusion. The results show that with the increase of the amount of aeolian sand, the dynamic elastic modulus of aeolian sand concrete shows a pattern of first decreasing, then increasing, and then decreasing; when no prestress is applied, the porosity of aeolian sand concrete first increases, then decreases, and then continues to increase. Among them, the porosity of aeolian sand concrete with a 40% content of aeolian sand decreases by 0.06% compared to that with a 0% content of aeolian sand, and decreases by 0.003% compared to that with a 60% content of aeolian sand; with the increase of prestress, the porosity of aeolian sand concrete with the same amount of aeolian sand increases gradually with the increase of damage degree. The porosity of concrete with 40% aeolian sand content increases by 0.33% when the damage degree is 0.0 compared to 0.3, with a 6.31% increase in the number of multi damage pores; under the coupling effect of multiple factors, when the amount of aeolian sand is 40%, the damage degree of the four groups of aeolian sand concrete before and after the coupling effect is 0.0, 0.1, 0.2, and 0.3, respectively, increases by 25.8%, 32.2%, 73.8%, and 85.8%, respectively; under the coupling effect of multiple factors, the content of aeolian sand is 60%, the damage degree is 0.2 and 0.3 groups, and the content of aeolian sand is 20%, the damage degree is 0.3 groups, which does not meet the standard requirements; under the coupling action of stress, freeze-thaw, salt intrusion and the amount of aeolian sand, the filling effect of aeolian sand on the internal pores of aeolian sand concrete decreases first, then increases, and then decreases with the increase of the amount of aeolian sand. The filling effect is further weakened after the action of stress. After the superposition of freeze-thaw and salt intrusion, the coupling effect of water and salt solution in frost heaving medium makes the variation law and range of physical and chemical characteristics of aeolian sand concrete show a great difference.


Assuntos
Exame Físico , Areia , Módulo de Elasticidade , Porosidade , Cloreto de Sódio , Cloreto de Sódio na Dieta
11.
J Acoust Soc Am ; 154(5): 2928-2936, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37938048

RESUMO

An unmanned surface vehicle (USV; Wave Glider) was deployed to study the coastal soundscape in shallow (less than 30 m) coastal waters off the coast of Cape Canaveral, FL, in July 2020 and January 2022. These surveys documented temporal and seasonal trends in biological sounds across a variety of habitats within an 812-km2 survey area, including sand shoals, sand-mud plains, and natural hardbottom. Among a broader diversity of identifiable and unidentifiable fish choruses recorded during the survey, a distinct and previously unidentified fish chorus was recorded; corroborating evidence suggests it and other sounds with similar spectral properties may be produced by Atlantic midshipman. Putative Atlantic midshipman sounds included an agnostic grunt and a seasonal chorus of persistent hums that peaked 3 h after sunset in the summer survey. While Atlantic midshipman have been demonstrated to have well-developed sonic muscles on their swim bladder, their acoustic behavior has not been previously described. Our use of a mobile passive acoustic platform combined with bottom sampling of fish communities highlights an important opportunity to identify previously undocumented biological sound sources in coastal habitats.


Assuntos
Batracoidiformes , Animais , Areia , Acústica , Sacos Aéreos , Aeronaves
12.
Nat Commun ; 14(1): 7310, 2023 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-37952036

RESUMO

Changes in upstream land-use have significantly transformed downstream coastal ecosystems around the globe. Restoration of coastal ecosystems often focuses on local-scale processes, thereby overlooking landscape-scale interactions that can ultimately determine restoration outcomes. Here we use an idealized bio-morphodynamic model, based on estuaries in New Zealand, to investigate the effects of both increased sediment inputs caused by upstream deforestation following European settlement and mangrove removal on estuarine morphology. Our results show that coastal mangrove removal initiatives, guided by knowledge on local-scale bio-morphodynamic feedbacks, cannot mitigate estuarine mud-infilling and restore antecedent sandy ecosystems. Unexpectedly, removal of mangroves enhances estuary-scale sediment trapping due to altered sedimentation patterns. Only reductions in upstream sediment supply can limit estuarine muddification. Our study demonstrates that bio-morphodynamic feedbacks can have contrasting effects at local and estuary scales. Consequently, human interventions like vegetation removal can lead to counterintuitive responses in estuarine landscape behavior that impede restoration efforts, highlighting that more holistic management approaches are needed.


Assuntos
Ecossistema , Estuários , Humanos , Retroalimentação , Areia , Nova Zelândia
13.
Biol Open ; 12(11)2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37909760

RESUMO

For terrestrial locomotion of animals and machines, physical characteristics of the substrate can strongly impact kinematics and performance. Snakes are an especially interesting system for studying substrate effects because their gait depends more on the environment than on their speed. We tested sidewinder rattlesnakes (Crotalus cerastes) on two surfaces: sand collected from their natural environment and vinyl tile flooring, an artificial surface often used to elicit sidewinding in laboratory settings. Of ten kinematic variables examined, two differed significantly between the substrates: the body's waveform had an average of ∼17% longer wavelength on vinyl flooring (measured in body lengths), and snakes lifted their bodies an average of ∼40% higher on sand (measured in body lengths). Sidewinding may also differ among substrates in ways we did not measure (e.g. ground reaction forces and energetics), leaving open clear directions for future study.


Assuntos
Crotalus , Areia , Animais , Fenômenos Biomecânicos , Meio Ambiente
14.
Water Res ; 247: 120781, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37918200

RESUMO

Agricultural managed aquifer recharge (Ag-MAR) is a promising approach to replenish groundwater resources using flood water and cropland as spreading grounds. However, site selection, particularly the layering of sediment deposits in the subsurface, can greatly influence Ag-MAR efficacy as it controls water flow and solute transport in the vadose zone. In this study, we use the HYDRUS-1D software to simulate water flow and solute transport from the land surface to the groundwater table in three vadose zone profiles (LS, MS, HS) characterized by differing fractions of sand (44 %, 47 %, and 64 %). For each profile, the single- and dual-porosity models (i.e., considering or not nonequilibrium water flow and solute transport) were calibrated using observed surface ponding, soil water content, and KBr breakthrough data. Water flow and bromide transport in the profile with the lowest sand fraction (LS) were best captured using the model that considered both preferential flow and nonequilibrium bromide transport. Water flow and bromide transport in the profile with the highest sand fraction (HS) was best simulated with the model that considered preferential flow and equilibrium bromide transport. Uniform water flow and nonequilibrium bromide transport provided the best fit for the third profile (MS). The degree of preferential flow was highest in the profile with the largest sand fraction (HS), which also showed the largest flow velocities compared to the profiles with lower sand amounts (LS and MS). Preferential flow did not significantly impact the overall water balance (within 3 %), but caused a significant decrease in vadose zone travel times (bromide) by up to 38 %, relative to a single-porosity model fit. Recharge efficiency varied between 88 % and 90 %, while the average travel times from the soil surface to groundwater varied up to 119 % (from 3.6 to 7.9 days) between the three sites. This study demonstrates that similar recharge efficiency can be achieved at sites with differing soil texture profiles, but subsurface heterogeneity can substantially affect contaminant transport processes and their travel times.


Assuntos
Água Subterrânea , Areia , Brometos , Solo , Água
15.
Water Res ; 247: 120816, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37952399

RESUMO

As one of five Laurentian Great Lakes, Lake Erie ranks among the top freshwater drinking sources and ecosystems globally. Historical and current agriculture mismanagement and climate change sustains the environmental landscape for late summer cyanobacterial harmful algal blooms, and consequently, cyanotoxins such as microcystin (MC). Microcystin microbial degradation is a promising mitigation strategy, however the mechanisms controlling the breakdown of MCs in Lake Erie are not well understood. Pelee Island, Ontario, Canada is located in the western basin of Lake Erie and the bacterial community in the sand has demonstrated the capacity of metabolizing the toxin. Through a multi-omic approach, the metabolic, functional and taxonomical signatures of the Pelee Island microbial community during MC-LR degradation was investigated over a 48-hour period to comprehensively study the degradation mechanism. Cleavage of bonds surrounding nitrogen atoms and the upregulation of nitrogen deamination (dadA, alanine dehydrogenase, leucine dehydrogenase) and assimilation genes (glnA, gltB) suggests a targeted isolation of nitrogen by the microbial community for energy production. Methylotrophic pathways RuMP and H4MPT control assimilation and dissimilation of carbon, respectively and differential abundance of Methylophilales indicates an interconnected role through electron exchange of denitrification and methylotrophic pathways. The detected metabolites did not resolve a clear breakdown pathway, but rather the diversity of products in combination with taxonomic and functional results supports that a variety of strategies are applied, such as epoxidation, hydroxylation, and aromatic degradation. Annual repeated exposure to the toxin may have allowed the community to adaptatively establish a novel pathway through functional plasticity and horizontal gene transfer. The culmination of these results reveals the complexity of the Pelee Island sand community and supports a dynamic and cooperative metabolism between microbial species to achieve MC degradation.


Assuntos
Cianobactérias , Microbiota , Lagos/microbiologia , Microcistinas/metabolismo , Areia , Cianobactérias/metabolismo , Nitrogênio/metabolismo , Ontário
16.
Sci Rep ; 13(1): 20547, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37996545

RESUMO

Mandacaru is a cactus with great socioeconomic potential, but lack of information about its cultivation hinders its domestication. Here, we aimed to evaluate the acclimatization and vegetative development of mandacaru under different substrates and irrigation levels. For this, seeds inoculated in vitro were grown for 120 days, being transplanted to pots containing four types of substrate (S1-caatinga soil + gravel; S2-washed sand + organic matter + soil + charcoal; S3-washed sand + cattle manure + soil + sand; S4-commercial organic substrate). Pots were irrigated with 100% of the field capacity (FC) once-a-week, or with 50% FC twice-a-week, and kept in a greenhouse for six months. The experimental design was completely randomized, in a 4 × 2 factorial scheme, with six replications. Plant height and diameter, axial and radial growth rate, fresh and dry mass of stem and root, water content, and photosynthetic pigments were determined. Growth was affected mainly by the substrate, with S4 resulting in higher growth and pigment content, while S1 was impaired and S2 and S3 resulted in intermediate growth. The use of S4 and 100% FC once per week was the best condition for mandacaru.


Assuntos
Cactaceae , Animais , Bovinos , Cactaceae/química , Areia , Brasil , Solo/química , Aclimatação
17.
Genes (Basel) ; 14(11)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-38002961

RESUMO

Golden moles (Chrysochloridae) and marsupial moles (Notoryctidae) are textbook examples of convergent evolution. Both taxa are highly adapted to subterranean lifestyles and have powerful limbs for digging through the soil/sand, ears that are adapted for low-frequency hearing, vestigial eyes that are covered by skin and fur, and the absence of optic nerve connections between the eyes and the brain. The eyes of marsupial moles also lack a lens as well as retinal rods and cones. Two hypotheses have been proposed to account for the greater degeneracy of the eyes of marsupial moles than golden moles. First, marsupial moles may have had more time to adapt to their underground habitat than other moles. Second, the eyes of marsupial moles may have been rapidly and recently vestigialized to (1) reduce the injurious effects of sand getting into the eyes and (2) accommodate the enlargement of lacrimal glands that keep the nasal cavity moist and prevent the entry of sand into the nasal passages during burrowing. Here, we employ molecular evolutionary methods on DNA sequences for 38 eye genes, most of which are eye-specific, to investigate the timing of relaxed selection (=neutral evolution) for different groups of eye-specific genes that serve as proxies for distinct functional components of the eye (rod phototransduction, cone phototransduction, lens/cornea). Our taxon sampling included 12 afrothere species, of which two are golden moles (Amblysomus hottentotus, Chrysochloris asiatica), and 28 marsupial species including two individuals of the southern marsupial mole (Notoryctes typhlops). Most of the sequences were mined from databases, but we also provide new genome data for A. hottentotus and one of the two N. typhlops individuals. Even though the eyes of golden moles are less degenerate than the eyes of marsupial moles, there are more inactivating mutations (e.g., frameshift indels, premature stop codons) in their cone phototransduction and lens/cornea genes than in orthologous genes of the marsupial mole. We estimate that cone phototransduction recovery genes were inactivated first in each group, followed by lens/cornea genes and then cone phototransduction activation genes. All three groups of genes were inactivated earlier in golden moles than in marsupial moles. For the latter, we estimate that lens/cornea genes were inactivated ~17.8 million years ago (MYA) when stem notoryctids were burrowing in the soft soils of Australian rainforests. Selection on phototransduction activation genes was relaxed much later (5.38 MYA), during the early stages of Australia's aridification that produced coastal sand plains and eventually sand dunes. Unlike cone phototransduction activation genes, rod phototransduction activation genes are intact in both golden moles and one of the two individuals of N. typhlops. A second marsupial mole individual has just a single inactivating mutation in one of the rod phototransduction activation genes (PDE6B). One explanation for this result is that some rod phototransduction activation genes are pleiotropic and are expressed in extraocular tissues, possibly in conjunction with sperm thermotaxis.


Assuntos
Marsupiais , Toupeiras , Animais , Masculino , Afrotheria , Austrália , Marsupiais/genética , Toupeiras/genética , Filogenia , Areia , Sêmen
18.
PLoS One ; 18(11): e0287552, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37917593

RESUMO

An accurate description of the stress-strain relationships of sand-fine mixtures is very important to analyze the soil's mechanical properties. Hence, a series of consolidated drained (CD) triaxial tests were performed on reconstructed sand-silt mixtures with sand contents of 0%, 16.67%, 28.57%, 50%, and 60% in the paper to examine the effect of the sand content on the stress-strain curves of the soil. Results show that for sand-fine mixtures with different sand contents, the stress-strain curves are also mainly strain softening though there exist different degrees of softening. In order to quantitatively describe the strain-softening characteristics of sand-fine mixtures, a modified Duncan-Chang model was developed. To verify the applicability of the modified mode, examples such as coral clay and undisturbed loess are described and predicted. There is a high consistency between theoretical and experimental values. Finally, a sand-content-dependent constitutive model that considered the effects of sand content and confining pressure was proposed based on the modified Duncan-Chang model by constructing the relationship between model parameters and confining pressure and sand content. The constitutive model was implemented in ABAQUS software and verified by comparing the calculated results with the triaxial test data of sand-fine mixtures under the confining pressure of 500 kPa. The comparison results indicate that the constitutive model can reflect the real characteristics of sand-fine mixtures.


Assuntos
Areia , Solo , Argila , China
19.
PLoS One ; 18(11): e0293317, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37917645

RESUMO

Domestic production of controlled-release, compost-based, and microbe-enhanced fertilizers is being expanded in the U.S. as a part of rural development. Sugarcane mill mud is a sterilized (≈90°C) agricultural byproduct in surplus that has received interests as a soil amendment in several Southern states, because of its high phosphorus and organic carbon contents. Addition of mill mud to sandy loam significantly increased the nodule formation compared to fertilized and unfertilized controls. Mill mud addition also resulted in pod yields similar to the fertilized control. Though not found in mill mud itself, mill mud additions correlated with an increase in soil Rhizobia as determined by deep 16S rRNA gene sequencing. We hypothesize that Firmicutes in sterilized mill mud induced Rhizobia that in turn enhanced soybean (Glycine max) growth. Collectively, mill mud enhanced the plant growth promoting bacteria when applied to a silt loam, although the relative influence of mill mud-derived bacteria, organic carbon, and nutrients is yet to be determined.


Assuntos
Rhizobium , Saccharum , Solo , Soja/microbiologia , Areia , Simbiose , RNA Ribossômico 16S/genética , Carbono
20.
J Med Invest ; 70(3.4): 464-470, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37940533

RESUMO

We previously developed two immune complex transfer enzyme immunoassays (ICT-EIA) to measure total adiponectin (T-AN) and high molecular weight adiponectin (H-AN) in urine and have verified their usefulness as biomarkers for diabetic kidney disease. In this study, we developed T-AN and H-AN assays using the sandwich EIA (Sand-EIA). The reactivities of Sand-EIAs were compared with ICT-EIAs by measuring size exclusion chromatography (SEC) fractions of urine and adiponectin standard. As a result, ICT-EIAs showed higher macromolecular specificity. We then analyzed the molecular profile of adiponectin in the urine of 5 patients with different eGFR stages by measuring SEC fractions of urine. The results showed that smaller adiponectin correlated relatively well with eGFR stage. Finally, because SEC is time-consuming, we investigated that the ratio of T-ANs by Sand-EIA and ICT-EIA could be a good indicator of the monomer adiponectin. The ratio was evaluated using 77 urine samples from patients with diabetes and showed a significant decrease at an earlier stage compared with other biomarkers. In conclusion, we demonstrated a new index to estimate monomer adiponectin in urine by using Sand-EIA and ICT-EIA, and urinary monomer adiponectin can be a good early indicator of deterioration of renal function in diabetic patients. J. Med. Invest. 70 : 464-470, August, 2023.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Humanos , Nefropatias Diabéticas/diagnóstico , Adiponectina/urina , Sensibilidade e Especificidade , Areia , Biomarcadores/urina
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