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1.
J Environ Manage ; 300: 113798, 2021 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-34562819

RESUMEN

The resuspension and sedimentation of particulate matter and the release of nutrients from sediment are important factors affecting the eutrophication of shallow lakes. The capture and removal of particles rich in nitrogen, phosphorus, and other nutrients at the bottom of lakes is of great significance for improving the management and eutrophication status of lakes. This study investigated the feasibility of applying lake bottom trap technology in seven different locations in Lake Chaohu, which is the fifth largest freshwater lake in China. The results showed that the trap in the western part of Lake Chaohu had the highest sedimentation rate and could capture most of the nutrients. The sedimentation rates were higher in spring and summer than in autumn and winter. The bottom trap effectively collected and preserved chlorophyll a, organic matter, total nitrogen, and total phosphorus. The trap per meter length (15-20 m wide) could catch 20.7-27.6 m3 of particles rich in nutrients with a water content of 50-70%, organic matter content of 281.9-375.8 kg, total nitrogen content of 24.5-32.6 kg, and total phosphorus content of 10.5-14 kg. The proposed bottom trap had little impact on the benthic organism system of the lake. The bottom trap technology used in this study could solve the problem of nitrogen, phosphorus, and algae accumulation in lakes and reservoirs, broaden the utility of lake hydrodynamics in environmental pollution control, and provide new ideas and strategies for the control and management of cumulative pollution in shallow lakes and reservoirs.


Asunto(s)
Sedimentos Geológicos , Lagos , China , Clorofila A , Monitoreo del Ambiente , Eutrofización , Nitrógeno/análisis , Nutrientes , Fósforo/análisis , Tecnología
2.
Sensors (Basel) ; 21(17)2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34502624

RESUMEN

Remote sensing techniques currently used to detect oil spills have not yet demonstrated their applicability to dispersed forms of oil. However, oil droplets dispersed in seawater are known to modify the local optical properties and, consequently, the upwelling light flux. Theoretically possible, passive remote detection of oil droplets was never tested in the offshore conditions. This study presents a field experiment which demonstrates the capability of commercially available sensors to detect significant changes in the remote sensing reflectance Rrs of seawater polluted by six types of dispersed oils (two crude oils, cylinder lubricant, biodiesel, and two marine gear lubricants). The experiment was based on the comparison of the upwelling radiance Lu measured in a transparent tank floating in full immersion in seawater in the Southern Baltic Sea. The tank was first filled with natural seawater and then polluted by dispersed oils in five consecutive concentrations of 1-15 ppm. After addition of dispersed oils, spectra of Rrs noticeably increased and the maximal increase varied from 40% to over three-fold at the highest oil droplet concentration. Moreover, the most affected Rrs band ratios and band differences were analyzed and are discussed in the context of future construction of algorithms for dispersed oil detection.


Asunto(s)
Contaminación por Petróleo , Petróleo , Aceites , Contaminación por Petróleo/análisis , Tecnología de Sensores Remotos , Agua de Mar
3.
Sensors (Basel) ; 21(10)2021 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-34067967

RESUMEN

In the contrary to surface oil slicks, dispersed oil pollution is not yet detected or monitored on regular basis. The possible range of changes of the local optical properties of seawater caused by the occurrence of dispersed oil, as well as the dependencies of changes on various physical and environmental factors, can be estimated using simulation techniques. Two models were combined to examine the influence of oceanic water type on the visibility of dispersed oil: the Monte Carlo radiative transfer model and the Lorenz-Mie model for spherical oil droplets suspended in seawater. Remote sensing reflectance, Rrs, was compared for natural ocean water models representing oligotrophic, mesotrophic and eutrophic environments (characterized by chlorophyll-a concentrations of 0.1, 1 and 10 mg/m3, respectively) and polluted by three different kinds of oils: biodiesel, lubricant oil and crude oil. We found out that dispersed oil usually increases Rrs values for all types of seawater, with the highest effect for the oligotrophic ocean. In the clearest studied waters, the absolute values of Rrs increased 2-6 times after simulated dispersed oil pollution, while Rrs band ratios routinely applied in bio-optical models decreased up to 80%. The color index, CI, was nearly double reduced by dispersed biodiesel BD and lubricant oil CL, but more than doubled by crude oil FL.


Asunto(s)
Contaminación por Petróleo , Algoritmos , Clorofila/análisis , Monitoreo del Ambiente , Océanos y Mares , Tecnología de Sensores Remotos
4.
Environ Sci Pollut Res Int ; 28(36): 50890-50907, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33973115

RESUMEN

Petroleum sludge is produced during oilfield development and production and can negatively impact the production area and surrounding environment. With increasing attention to the environmental protection of oilfields, finding an energy-efficient, environmentally sound, cost-effective and socially acceptable sludge treatment method is crucial to the sustainable development of oil companies. However, there are several problems in the selection process: ① there is no effective index system for the evaluation of treatment technologies; ② there is data uncertainty and loss of information; ③ experts in the field often make one-sided decisions; and ④ the common decision models fail to balance the general effect and local dominance of a treatment technology. This study is innovative in the following aspects: ① a decision index system of petroleum sludge treatment technology is established; ② the interval-valued Pythagorean fuzzy set effectively managed data uncertainty and loss of information; ③ the redundancy-based expert weighting method is used to avoid one-sided decisions; and ④ using the basic ideas of the VIKOR model to balance the general effect and local dominance of a technology. Example verification proved the effectiveness of this method and a sensitivity analysis showed the results were reliable. Finally, this study compared the results obtained by three other similar methods, and comparative analysis demonstrated that this approach effectively evaluated and selected petroleum sludge treatment technologies. This study improves the rationality of petroleum sludge treatment technology selection and provides a necessary reference for the selection of treatment technology for other petroleum pollutants.


Asunto(s)
Petróleo , Aguas del Alcantarillado , Tecnología , Incertidumbre
5.
Environ Pollut ; 286: 117195, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33975218

RESUMEN

The characteristics of primary gas/aerosol and secondary aerosol emissions were identified for small passenger vehicles using typical fuel types in South Korea (gasoline, liquefied petroleum gas (LPG), and diesel). The generation of secondary organic aerosol (SOA) was explored using the potential aerosol mass (PAM) oxidation flow reactor. The primary emissions did not vary significantly between fuel types, combustion technologies, or aftertreatment systems, while the amount of NH3 was higher in gasoline and LPG vehicle emissions than that in diesel vehicle emissions. The SOA emission factor was 11.7-66 mg kg-fuel-1 for gasoline vehicles, 2.4-50 mg kg-fuel-1 for non-diesel particulate filter (non-DPF) diesel vehicles (EURO 2-3), 0.4-40 mg kg-fuel-1 for DPF diesel vehicles (EURO 4-6), and 3-11 mg kg-fuel-1 for LPG vehicles (lowest). The carbonaceous aerosols (equivalent black carbon (eBC) + primary organic aerosol + SOA) of diesel vehicles in EURO 4-6 were reduced by up to 95% compared to those in EURO 2-3. The expected SOA yield increased through the hot-condition combustion section of a vehicle, over the SOA range of 0.2-155 µg m-3. These results provide the necessary data to analyze all types of SOA generated by the gas-phase oxidation in vehicle emissions in metropolitan areas.


Asunto(s)
Contaminantes Atmosféricos , Petróleo , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Gasolina/análisis , Vehículos a Motor , Tecnología , Emisiones de Vehículos/análisis
6.
PLoS One ; 16(4): e0250588, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33909681

RESUMEN

Aimed at the technical problems of low drilling speed and difficult rock-breaking in deep-well and hard rock-stratum, particle waterjet coupled impact rock-breaking technology in rotary drilling is put forward in this paper. Firstly, the working principle of particle jet impact rock-breaking in rotary drilling was introduced, and the acceleration model of particle jet and the damage model of rock were established. The acceleration mechanism of particles and dynamic damage evolution process of rock under particle jet were studied, which showed that the broken pit and rock damage would increase with time gone on, and damage evolution of rock presented the radial expansion. Then, experimental device of particle jet coupled impact rock-breaking in rotary state was developed, and the effect of jet parameters on penetration depth and failure volume was analyzed with comparison of la experiment and numerical simulation. The results showed that drilling speed with particle jet impact is twice that of conventional drilling, and combination nozzles layout of impact angle with 8°and 20° can achieve rock-drilled rapidly, which also demonstrated the correctness of simulation method. The device development and the rock-breaking results analysis would be of great value for engineering application.


Asunto(s)
Yacimiento de Petróleo y Gas , Industria del Petróleo y Gas/métodos , Aceleración , Equipos y Suministros , Humanos , Modelos Teóricos , Industria del Petróleo y Gas/instrumentación
7.
Mar Genomics ; 55: 100803, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33517980

RESUMEN

Streptomyces sp. SCSIO 03032, isolated from a deep-sea sediment sample (-3412 m) from the Indian Ocean, produces several classes of bioactive compounds including α-pyridone antibiotics (piericidins), polycyclic macrolactams (heronamides) and bisindole alkaloids (spiroindimicins, indimicins and lynamicins). Here we report the complete genome sequence of Streptomyces sp. SCSIO 03032, which consists of a 6,287,975 bp linear chromosome. The genome analysis reveals the presence of 29 putative biosynthetic gene clusters for secondary metabolites, including those for piericidins, heronamides and spiroindimicins/indimicins/lynamicins. The genome sequence suggests that Streptomyces sp. SCSIO 03032 could be a producer for novel bioactive natural products with potential applications in drug discovery.


Asunto(s)
Productos Biológicos/química , Genoma Bacteriano , Sedimentos Geológicos/microbiología , Streptomyces/genética , Océano Índico , Secuenciación Completa del Genoma
8.
Mar Genomics ; 56: 100807, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33632424

RESUMEN

Salinimonas sediminis N102T is a cold-adapted, slightly halophilic piezophile isolated from deep-sea sediment (4700 m) of the New Britain Trench. In this study, we report the complete genome sequence of S. sediminis N102T, which is comprised of 4,440,293 base pairs with a mean G + C content of 48.2 mol%. The complete genome harbors 3851 predicted protein-coding genes, 70 tRNA genes and 15 rRNA genes. Abundant genes in the genome were predicted to be linked to bacterial deep-sea lifestyle. The complete genome sequence of S. sediminis N102T provides insights into the microbial adaptation strategies to the deep-sea environment.


Asunto(s)
Alteromonadaceae/genética , Genoma Bacteriano , Sedimentos Geológicos/microbiología , Océano Pacífico , Secuenciación Completa del Genoma
9.
Mar Genomics ; 56: 100818, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33632425

RESUMEN

Microbacterium sediminis YLB-01T, a piezotolerant and psychrotolerant actinomycete, was isolated from deep-sea sediment of the South-West Indian Ocean and could be a good model for understanding the adaptation of extremophiles to the benthic piezosphere. Here, we report the analysis of the complete genome sequence of strain YLB-01T. The genome sequence consists of a single circular chromosome comprising 2,792,195 bp and a linear plasmid comprising 127,669 bp with G + C content of 71.76 and 68.49 mol%, respectively. In this regard, strain YLB-01T possesses the smallest genome size but the highest G + C content among the genus Microbacterium sequenced to date. As the first complete genome sequence of the genus Microbacterium isolated from deep-sea environment, the strain YLB-01T genome is unique or enriched in genes involved in xenobiotics biodegradation and metabolism, compatible solutes, and transposases, some of which might be related to bacterial enhancement of ecological fitness in the deep sea.


Asunto(s)
Adaptación Biológica/genética , Genoma Bacteriano , Sedimentos Geológicos/microbiología , Ambiente , Océano Índico , Microbacterium/genética , Secuenciación Completa del Genoma
10.
PLoS One ; 16(2): e0246656, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33561170

RESUMEN

In this work, molecular diversity of two hypersaline microbial mats was compared by Whole Genome Shotgun (WGS) sequencing of environmental DNA from the mats. Brava and Tebenquiche are lakes in the Salar de Atacama, Chile, where microbial communities are growing in extreme conditions, including high salinity, high solar irradiance, and high levels of toxic metals and metaloids. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. The mat from Brava was more rich and diverse, with a higher number of different taxa and with species more evenly distributed. At the phylum level, Proteobacteria, Cyanobacteria, Chloroflexi, Bacteroidetes and Firmicutes were the most abundant, including ~75% of total sequences. At the genus level, the most abundant sequences were affilitated to anoxygenic phototropic and cyanobacterial genera. In Tebenquiche mats, Proteobacteria and Bacteroidetes covered ~70% of the sequences, and 13% of the sequences were affiliated to Salinibacter genus, thus addressing the lower diversity. Regardless of the differences at the taxonomic level, functionally the two mats were similar. Thus, similar roles could be fulfilled by different organisms. Carbon fixation through the Wood-Ljungdahl pathway was well represented in these datasets, and also in other mats from Andean lakes. In spite of presenting less taxonomic diversity, Tebenquiche mats showed increased abundance and variety of rhodopsin genes. Comparison with other metagenomes allowed identifying xantorhodopsins as hallmark genes not only from Brava and Tebenquiche mats, but also for other mats developing at high altitudes in similar environmental conditions.


Asunto(s)
Ciclo del Carbono/fisiología , Lagos/microbiología , Rodopsina/metabolismo , Bacteroidetes/genética , Biodiversidad , Chile , Cianobacterias/genética , Sedimentos Geológicos/microbiología , Microbiota/genética , Filogenia , Proteobacteria/genética , ARN Ribosómico 16S/genética , Rodopsina/genética , Salinidad , Secuenciación Completa del Genoma/métodos
11.
Sci Total Environ ; 755(Pt 1): 142482, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33011597

RESUMEN

Methoxyfenozide is widely employed in paddy land and can flow out into the aquatic environment. The present study combines two approaches, namely, an aquatic microcosm simulation experiment and a multimedia fugacity model, to study the fate and distribution of methoxyfenozide in an aquatic microcosm containing water, sediment, aquatic plants, and zebrafish. The model results indicated that the simulated concentrations agreed with the observed values within one order of magnitude. The degradation rate was less than 7.0% in the three types of aquatic microcosms at 740 h in the model. Methoxyfenozide exhibited very high persistence in the aquatic microcosm. Water played a key role in the fate of methoxyfenozide, acting as a sink in the simulated aquatic environment, followed by sediment. Only approximately 2% of methoxyfenozide entered the organisms (zebrafish and Egeria densa Planch). Methoxyfenozide underwent a significant transport process between the water and sediment. The applications of multimedia fugacity models are useful for understanding the behaviors, fate, and transport of pesticides after their release into the environment and to facilitate risk assessment and management activities.


Asunto(s)
Sedimentos Geológicos , Contaminantes Químicos del Agua , Animales , Hidrazinas , Hormonas Juveniles , Multimedia , Agua , Contaminantes Químicos del Agua/análisis
12.
Mar Genomics ; 58: 100833, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33341425

RESUMEN

Janibacter indicus YB324, a gram-positive, aerobic and non-motile actinobacterium isolated from south Atlantic sediment at a depth of 2875 m. The complete genome sequence of the strain YB324 was obtained using PacBio Sequel HGAP.4 and comprised of 3,369,845 base pairs with a 71.3 mol% G + C content, 3225 protein-coding genes, 53 RNAs. In silico analysis confirmed the genes associated with polysaccharide hydrolyzation, nitrite reduction, and phenol degradation. Multiple natural product biosynthesis gene clusters were identified as well. The complete genome sequence will provide insight into the potential use of this strain in biotechnological and natural product biosynthesis applications.


Asunto(s)
Actinobacteria/genética , Genoma Bacteriano , Sedimentos Geológicos/microbiología , Océano Atlántico , Filogenia , Secuenciación Completa del Genoma
13.
J Hazard Mater ; 401: 123282, 2021 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-32634659

RESUMEN

Rhizoremediation is increasingly becoming a green and sustainable alternative to physico-chemical methods for remediation of contaminated environments through the utilization of symbiotic relationship between plants and their associated soil microorganisms in the root zone. The overall efficiency can be enhanced by identifying suitable plant-microbe combinations for specific contaminants and supporting the process with the application of appropriate soil amendments. This approach not only involves promoting the existing activity of plants and soil microbes, but also introduces an adequate number of microorganisms with specific catabolic activity. Here, we reviewed recent literature on the main mechanisms and key factors in the rhizoremediation process with a particular focus on soils contaminated with total petroleum hydrocarbon (TPH). We then discuss the potential of different soil amendments to accelerate the remediation efficiency based on biostimulation and bioaugmentation processes. Notwithstanding some successes in well-controlled environments, rhizoremediation of TPH under field conditions is still not widespread and considered less attractive than physico-chemical methods. We catalogued the major pitfalls of this remediation approach at the field scale in TPH-contaminated sites and, provide some applicable situations for the future successful use of in situ rhizoremediation of TPH-contaminated soils.


Asunto(s)
Petróleo , Contaminantes del Suelo , Biodegradación Ambiental , Hidrocarburos , Suelo , Microbiología del Suelo , Contaminantes del Suelo/análisis , Tecnología
14.
PLoS One ; 15(7): e0233912, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32609779

RESUMEN

This article reports Australia's first confirmed ancient underwater archaeological sites from the continental shelf, located off the Murujuga coastline in north-western Australia. Details on two underwater sites are reported: Cape Bruguieres, comprising > 260 recorded lithic artefacts at depths down to -2.4 m below sea level, and Flying Foam Passage where the find spot is associated with a submerged freshwater spring at -14 m. The sites were discovered through a purposeful research strategy designed to identify underwater targets, using an iterative process incorporating a variety of aerial and underwater remote sensing techniques and diver investigation within a predictive framework to map the submerged landscape within a depth range of 0-20 m. The condition and context of the lithic artefacts are analysed in order to unravel their depositional and taphonomic history and to corroborate their in situ position on a pre-inundation land surface, taking account of known geomorphological and climatic processes including cyclone activity that could have caused displacement and transportation from adjacent coasts. Geomorphological data and radiometric dates establish the chronological limits of the sites and demonstrate that they cannot be later than 7000 cal BP and 8500 cal BP respectively, based on the dates when they were finally submerged by sea-level rise. Comparison of underwater and onshore lithic assemblages shows differences that are consistent with this chronological interpretation. This article sets a foundation for the research strategies and technologies needed to identify archaeological targets at greater depth on the Australian continental shelf and elsewhere, building on the results presented. Emphasis is also placed on the need for legislation to better protect and manage underwater cultural heritage on the 2 million square kilometres of drowned landscapes that were once available for occupation in Australia, and where a major part of its human history must lie waiting to be discovered.


Asunto(s)
Arqueología/métodos , Grupo de Ascendencia Oceánica/historia , Paleontología/métodos , Australia , Fósiles , Sedimentos Geológicos , Historia Antigua , Humanos , Océanos y Mares , Elevación del Nivel del Mar , Tecnología/métodos , Australia Occidental
15.
Microbiol Res ; 238: 126504, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32534383

RESUMEN

The present study involved identification of genes which are present in the genome of native bacteria to make them effective tools for bioremediation of persistent organic pollutants (POPs). During this study, forty-one POPs (naphthalene, toluene and petrol) metabolizing bacteria were isolated from tannery effluents and petrol contaminated soil samples by successive enrichment culturing. The taxonomic diversity and gene repertoire conferring POPs degradation ability to the isolated bacterial community were studied through whole genome shotgun sequencing of DNA consortium. The DNA consortium contained equimolar concentration of DNA extracted from each bacterial isolate using organic method. To add a double layer of confirmation the established DNA consortium was subjected to 16S rRNA metagenome sequencing and whole genome shotgun sequencing analysis. Biodiversity analysis revealed that the consortium was composed of phyla Firmicutes (80 %), Proteobacteria (12 %) and Actinobacteria (5%). Genera found included Bacillus (45 %), Burkholderia (25 %), Brevibacillus (9%) and Geobacillus (4%). Functional profiling of consortium helped us to identify genes associated with degradation pathways of a variety of organic compounds including toluene, naphthalene, caprolactam, benzoate, aminobenzoate, xylene, 4-hydroxyphenyl acetic acid, biphenyl, anthracene, aminobenzoate, chlorocyclohexane, chlorobenzene, n-phenylalkanoic acid, phenylpropanoid, salicylate, gentisate, central meta cleavage of aromatic compounds, cinnamic acid, catechol and procatechuate branch of ß-ketoadipate pathway, phenyl-acetyl CoA and homogentisate catabolic pathway. The information thus generated has ensured not only biodegradation potential but also revealed many possible future applications of the isolated bacteria.


Asunto(s)
Bacterias/clasificación , Bacterias/metabolismo , Biodegradación Ambiental , Contaminantes Orgánicos Persistentes/metabolismo , Contaminación por Petróleo , ADN Bacteriano , Gasolina/microbiología , Redes y Vías Metabólicas , Metagenoma , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Aguas Residuales/microbiología , Secuenciación Completa del Genoma
16.
Mar Genomics ; 54: 100782, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32387528

RESUMEN

Whole genome sequences of four bacterial strains Dietzia maris SST1, Pseudomonas zhaodongensis SST2, Pseudomonas sp. SST3 and Halomonas sulfidaeris SST4, recovered from the South Shetland Trench sediment in Antarctica were analyzed using Ion Torrent sequencing technology. The respective sizes of their genomes (3.88, 4.99, 5.60 and 4.25 Mb) and GC contents (70.0, 60.3, 59.9 and 53.8%) are in agreement with these values of other strains of the species. The bacterial strains displayed promising antimicrobial activity against a number of pathogenic bacterial and fungal species. Whole genomes have been assembled and biosynthetic gene clusters (BGCs) have been identified using the antibiotics and Secondary Metabolite Analysis Shell (antiSMASH) web platform. Comparative analysis of the genome sequences revealed that the strains host abundant BGCs encoding for terpenes, siderophores, arylpolyene, bacteriocins, and lassopeptides. Furthermore, the key stress-related genes were identified and their distribution provided an insight into how these isolates adapt to key marine environmental conditions. This comprehensive study is a contribution to understanding the nature of life on the deep-sea environments.


Asunto(s)
Actinobacteria/genética , Genoma Bacteriano , Halomonas/genética , Pseudomonas/genética , Regiones Antárticas , Sedimentos Geológicos , Secuenciación de Nucleótidos de Alto Rendimiento , Océanos y Mares , Secuenciación Completa del Genoma
17.
Environ Monit Assess ; 192(5): 310, 2020 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-32328813

RESUMEN

This study presents a comparison of SO2 concentrations simulated by a dispersion model, using as input both emission data inventories of the Mexican petroleum company Petroleos Mexicanos and emissions estimated by the Ozone Monitoring Instrument on board of the Aura satellite, contrasting results with data measured by an on-ground sensor located in the city of Villahermosa, Tabasco, Mexico, during the month of February 2013. The emissions used came from both oil extraction facilities located in the Gulf of Mexico and oil installations located on land. The days selected to be modeled were those when the winds had a northern component, and there was an observable emission detected by the Aura satellite coming from the emission sources. Evaluation analysis of the results showed that satellite data overestimate SO2 concentration, while the inventories of Petroleos Mexicanos underestimate it. Good correlations (r, r2, and concordance index) were observed between simulated and measured concentrations when the winds had a high frequency of directions of northern component and not-so weak speeds. It is recommended that Mexican oil company calculates more precise and updated emission inventories, considering not only a higher sulfur content of the gas emitted to the atmosphere and its combustion process but also from other existing sources of SO2 emission in this region.


Asunto(s)
Contaminantes Atmosféricos , Monitoreo del Ambiente , Tecnología de Sensores Remotos , Dióxido de Azufre , Contaminantes Atmosféricos/análisis , Simulación por Computador , Monitoreo del Ambiente/métodos , Golfo de México , México , Modelos Teóricos , Ozono , Petróleo , Comunicaciones por Satélite , Dióxido de Azufre/análisis
18.
Environ Monit Assess ; 192(5): 307, 2020 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-32328814

RESUMEN

Conventional water quality measurements are nearly impossible during and immediately after extreme storms due to dangerous conditions. In this study, remotely sensed reflectance is used to develop a regression equation that quantifies total suspended solids (TSS) in near real-time after Hurricane Harvey. The application focused specifically on sediment loading and deposition and its potential impacts on the Houston Ship Channel and Galveston Bay riverine-estuarine system. The European Space Agency's Sentinel-2 satellite captured images at critical points in the storm's progression, necessitating the development of a new algorithm for this relatively new satellite mission. Several linear regressions were analyzed with the goal of developing a simple one- or two-band equation, and the final model uses the red and near infrared bands (R2 = 0.74). Results show that record flows during Harvey delivered unprecedented suspended sediment loads to the Gulf of Mexico at concentrations above 125 mg/L with a mean concentration of 43 mg/L across the bay. The study findings demonstrated that it took up to 11 days after the storm for sediment transport to abate.


Asunto(s)
Tormentas Ciclónicas , Monitoreo del Ambiente , Clima Extremo , Modelos Teóricos , Calidad del Agua , Agua , Monitoreo del Ambiente/instrumentación , Sedimentos Geológicos/química , Golfo de México , Tecnología de Sensores Remotos , Comunicaciones por Satélite , Análisis Espectral , Texas , Agua/química
19.
J Hum Evol ; 142: 102744, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32199300

RESUMEN

The evolution of heat treatment for stone artefact production is a subject of major interest for our understanding of early modern humans. In this study, we examine the evidence from one region in Australia to provide a new record of the antiquity of heat treatment, explore chronological shifts in the frequency of heat treatment, and discuss the implications of these findings for early population dynamics and the technical knowledge early settlers might have brought with them. Until now, Australian heat treatment has only dated back 25000 years. This study of the Willandra Lakes, including Lake Mungo, has identified the oldest systematic evidence of heat treatment yet reported in Australia, dating to ∼42000 years. We also document time-dependent directional change in the frequency of the practice. At those early times, with over 60% of all silcrete artefacts heat-treated, we hypothesize that the practice was mastered and integrated as a recurrent technical solution to the complexities of knapping silcrete. Over time, the use of heat treatment decreased progressively until less than 10% of the artefacts were heat-treated in the terminal Holocene. This trajectory has implications for understanding the antiquity of heat treatment on the Australian continent and for investigating the factors that governed its use.


Asunto(s)
Arqueología , Incendios , Tecnología , Sedimentos Geológicos/análisis , Calor , Humanos , Lagos , Nueva Gales del Sur
20.
Mar Drugs ; 18(3)2020 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-32106586

RESUMEN

Dermacoccus abyssi strain MT1.1T is a piezotolerant actinobacterium that was isolated from Mariana Trench sediment collected at a depth of 10898 m. The organism was found to produce ten dermacozines (A‒J) that belonged to a new phenazine family and which displayed various biological activities such as radical scavenging and cytotoxicity. Here, we report on the isolation and identification of a new dermacozine compound, dermacozine M, the chemical structure of which was determined using 1D and 2D-NMR, and high resolution MS. A whole genome sequence of the strain contained six secondary metabolite-biosynthetic gene clusters (BGCs), including one responsible for the biosynthesis of a family of phenazine compounds. A pathway leading to the biosynthesis of dermacozines is proposed. Bioinformatic analyses of key stress-related genes provide an insight into how the organism adapted to the environmental conditions that prevail in the deep-sea.


Asunto(s)
Actinobacteria/genética , Aclimatación , Actinobacteria/aislamiento & purificación , Actinobacteria/metabolismo , Animales , Sedimentos Geológicos/microbiología , Océanos y Mares , Fenazinas/metabolismo , Filogenia , ARN Ribosómico 16S/genética , Secuenciación Completa del Genoma
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