Notes
Notes - notes.io |
Delivering drinking water with stable quality in metropolitan cities is a big challenge. This study investigated the year-long dynamics of dissolved organic matter (DOM) in the tap water and source water of a metropolitan city in southern China using fluorescence spectroscopy. The DOM detected in the tap water, and source water of Shenzhen city was season and location-dependent. A year-long cyclic trend of DOM was found with predominate protein-like fluorescence in the dry season compared to the humic-like enriched DOM in the wet season. A general DOM pattern was estimated by measuring the shift in dominant fluorescence regions on the excitation-emission matrix (EEM). The difference in fluorescent DOM (FDOM) composition (in terms of the ratio of protein-like to humic-like fluorescence) was above 200% between wet and dry seasons. The taps associated with reservoirs receiving water from the eastern tributary of Dongjiang River showed significant changes in protein-like contents than the taps with source water originating from the western part of the river. This study highlights the importance of optimizing drinking water treatment plants' operational conditions after considering seasonal changes and source water characteristics.Conventional diffused aeration systems (such as fine-bubble diffusers) exhibit a poor oxygen transfer in wastewater treatment plants (WWTPs), particularly when operating at sludge concentrations higher than 15 g L-1. The supersaturated dissolved oxygen (SDOX) system has been proposed as an alternative for supplying dissolved oxygen (DO) at high mixed liquor suspended solids (MLSS) concentrations. ARS-1620 concentration The advantages introduced by such technology include the possibility of operating WWTPs at much higher than usual MLSS concentrations, increasing the treatment capacity of WWTPs. Recent studies have demonstrated that the SDOX system has higher oxygen transfer rates (OTRs) and oxygen transfer efficiencies (OTEs) relative to fine-bubble diffusers. However, it is unknown if the high-pressure conditions introduced by SDOX may possibly impact the biological performance of WWTPs. In this study, the effects of SDOX technology on the biological performance of a membrane bioreactor (MBR) were evaluated. The MBR was operated at an MLSS concentration of approximately 15 g L-1 in four phases as follows (P1) with bubble diffusers, (P2) with an SDOX unit, (P3) with the bubble diffusers, and (P4) with the SDOX unit. The performance of the MBR was assessed by monitoring the sludge concentration, as well as changes in the particle size distribution (PSD), sludge activity, organic matter removal and nitrification performance, and changes in the microbial community within the MBR. The operational conditions exerted by the SDOX technology did not affect the concentration of active biomass during the study period. The biological performance of the MBR was not affected by the introduction of the SDOX technology. link2 Finally, the microbial community was relatively stable although some variations at the family and genus level were evident during each of the study phases. Therefore, the SDOX system can be proposed as an alternative technology for DO supply in WWTPs increasing the overall treatment capacity.The biodegradation of aniline is an important process related to the attenuation of aniline pollution at contaminated sites. Aniline contamination could occur in various pH (i.e., acidic, neutral, and alkaline) environments. However, little is known about preferred pH conditions of diverse aniline degraders at different sites. This study investigated the active aniline degraders present under contrasting pH environments using three aniline-contaminated cultures, namely, acidic sludge (ACID-S, pH 3.1), neutral river sediment (NEUS, pH 6.6), and alkaline paddy soil (ALKP, pH 8.7). Here, DNA-based stable isotope probing coupled with high-throughput sequencing revealed that aniline degradation was associated with Armatimonadetes sp., Tepidisphaerales sp., and Rhizobiaceae sp. in ACID-S; Thauera sp., Zoogloea sp., and Acidovorax sp. in NEUS; Delftia sp., Thauera sp., and Nocardioides sp. in ALKP. All the putative aniline-degrading bacteria identified were present in the "core" microbiome of these three cultures; however, only an appropriate pH may facilitate their ability to metabolize aniline. In addition, the biotic interactions between putative aniline-degrading bacteria and non-direct degraders showed different characteristics in three cultures, suggesting aniline-degrading bacteria employ diverse survival strategies in different pH environments. These findings expand our current knowledge regarding the diversity of aniline degraders and the environments they inhabit, and provide guidance related to the bioremediation of aniline contaminated sites with complex pH environments.Wildfires, or bushfires, are one of the most destructive natural disasters in Australia, which can cause many deaths of stock, native animals, sometimes humans, and huge impacts on infrastructure. Reconstructing past wildfires and exploring the links between wildfires and climate are essential for understanding the dynamics of wildfires and for predicting future risks. In this study, the frequency of wildfires in northeastern Australia over the past 25,000 years was reconstructed from the charcoal records preserved in peat and lake sediments. The results showed that the frequency of wildfires were relatively low during the cool last glacial period and the warm mid Holocene, indicating that the stable mean climate conditions, whether cool or warm, would not independently initiate increased wildfires in northeastern Australia. The most frequent wildfires occurred during the last deglaciation period, when Earth's climate warmed and the warming rate was the highest over the last 25,000 years, before recent anthrorios.Cyflumetofen (CYF) is a novel chiral acaricide widely used in commercial crops to control mites. The environmental risks exposed by CYF in the soil, especially at the enantiomer level, remain unclear. We found that the (+)-CYF enantiomer was preferentially degraded in acid-soil, resulting in (-)-CYF enrichment. link3 16S rRNA and qPCR analysis indicated that decreased bacterial abundance by 12.79-61.80% and 2.52-52.48% in (-)-CYF treatment and (+)-CYF treatment, respectively. Diversity was also decreased with (-)-CYF treatment. Interestingly, several beneficial bacteria, for instance, Alphaproteobacteria (class), Sphingomonadaceae (family), and Arthrobacter (specise) were more enriched following (-)-CYF. The abundance of N2-fixing bacteria showed a sustained reduction with time, and the decrease was 3.24-72.94% with (-)-CYF and 25.37-73.11% with (+)-CYF treatment. Compared with the (+)-CYF treatment could positively promote nitrification, while the treatment (-)-CYF significantly reduced the abundance of amoA gene; namely it significantly negatively affected the nitrification in the nitrogen cycle. Through our further research, we found that Actinobacteria, Alphaproteobacteria, Lysobacter; Sphingomonas, Patescibacteria, Saccharimonadia, and Saccharimonadales showed synergistic effects with the nitrogen cycling-related genes nifH and amoA. These results contribute to a comprehensive environmental risk assessment of CYF in acid-soil at the enantiomer level.Ocean acidification (OA) may induce major shifts in the structure and function of coastal marine ecosystems. Studies in volcanic CO2 vents, where seawater is naturally acidified, have reported an overall simplification of fish assemblages structure, while some primary producers are likely to increase their biomass under elevated concentration of CO2. Here we used temperate shallow CO2 vents located around the coast of Ischia island (Italy) to assess the effects of OA on necto-benthic fish assemblages associated with the foundation seagrass species Posidonia oceanica in the Mediterranean Sea. We compared P. oceanica meadow structure, its epiphytic community and the associated fish assemblage structure and diversity at vents with low pH sites and reference sites with ambient pH using underwater visual census strip transects, in two seasons (fall 2018 and summer 2019). Data were analysed using both univariate and multivariate statistical techniques. Results showed greater P. oceanica habitat complexity (i.e. shoot density) and lower abundance of epiphytic calcareous species (e.g. coralline algae) at the vents than reference sites. Total abundance of adult and juvenile fish was higher at vents than reference sites, while no differences were found for species richness and composition. Overall, the herbivore Sarpa salpa stands out among the species contributing the most to dissimilarity between vents and reference sites, showing higher abundances under OA conditions. This pattern could be explained by the combined effect of a positive response to the higher structural meadows complexity and the greater seagrasses palatability/nutritional value occurring at the vents, which may help herbivores to withstand the higher energetic cost to live under high pCO2/low pH conditions. Our results indicate that necto-benthic fish assemblages associated with the Mediterranean P. oceanica ecosystem may cope with OA under the CO2 emission scenarios forecasted for the end of this century.Over 160 years ago, scientists made the first microscopic observations of angiosperm pollen. Unlike in animals, male meiosis in angiosperms produces a haploid microspore that undergoes one asymmetric division to form a vegetative cell and a generative cell. These two cells have distinct fates the vegetative cell exits the cell cycle and elongates to form a tip-growing pollen tube; the generative cell divides once more in the pollen grain or within the growing pollen tube to form a pair of sperm cells. The concept that male germ cells are less active than the vegetative cell came from biochemical analyses and pollen structure anatomy early in the last century and is supported by the pollen transcriptome data of the last decade. However, the mechanism of how and when the transcriptional repression in male germ cells occurs is still not fully understood. In this review, we provide a brief account of the cytological and metabolic differentiation between the vegetative cell and male germ cells, with emphasis on the role of temporary callose walls, dynamic nuclear pore density, transcription repression, and histone variants. We further discuss the intercellular movement of small interfering RNA (siRNA) derived from transposable elements (TEs) and reexamine the function of TE expression in male germ cells.
Tobacco use is a public health concern, and adolescents are at an increased risk of starting and continuing to use tobacco relative to other age groups. Parent involvement and other social environmental factors may influence the development and persistence of tobacco use behaviors in adolescence. This study used the nationally representative Population Assessment of Tobacco and Health (PATH) study data set, and responses from 7025 adolescent participants were analyzed to illustrate the longitudinal relationship between social environment influences and use of adolescent electronic nicotine delivery systems (i.e., ENDS).
Social environmental factors were assessed at Wave 3 and then compared to electronic nicotine delivery systems (ENDS) status transitions (i.e., initiation, expansion, persistence) at follow-up. Survey-weighted multivariable logistic regression models were used to calculate adjusted odds ratios (AOR) and 95% confidence intervals (CI).
Initiation and persistence of ENDS use were associated with tobacco availability in the house, perception of having no adverse parent reaction to discovering ENDS use and having a best friend who uses ENDS.
Homepage: https://www.selleckchem.com/products/ars-1620.html
|
Notes.io is a web-based application for taking notes. You can take your notes and share with others people. If you like taking long notes, notes.io is designed for you. To date, over 8,000,000,000 notes created and continuing...
With notes.io;
- * You can take a note from anywhere and any device with internet connection.
- * You can share the notes in social platforms (YouTube, Facebook, Twitter, instagram etc.).
- * You can quickly share your contents without website, blog and e-mail.
- * You don't need to create any Account to share a note. As you wish you can use quick, easy and best shortened notes with sms, websites, e-mail, or messaging services (WhatsApp, iMessage, Telegram, Signal).
- * Notes.io has fabulous infrastructure design for a short link and allows you to share the note as an easy and understandable link.
Fast: Notes.io is built for speed and performance. You can take a notes quickly and browse your archive.
Easy: Notes.io doesn’t require installation. Just write and share note!
Short: Notes.io’s url just 8 character. You’ll get shorten link of your note when you want to share. (Ex: notes.io/q )
Free: Notes.io works for 12 years and has been free since the day it was started.
You immediately create your first note and start sharing with the ones you wish. If you want to contact us, you can use the following communication channels;
Email: [email protected]
Twitter: http://twitter.com/notesio
Instagram: http://instagram.com/notes.io
Facebook: http://facebook.com/notesio
Regards;
Notes.io Team