ABSTRACT: A higher denitrification rate was realized via controlling the mass ratio of pyrite and poly(3-hydroxybutyrate-hydroxyvalerate) (PHBV) under natural aerobic conditions. The results showed that the suitable mass ratio of PHBV and pyrite could be 1:2 with its removal efficiency of nitrogen and phosphorus of 99.7 and 53.4%, respectively. The PHBV/pyrite system has formed the spatial patterns of the biofilm community, such as Dechloromons attached to the pyrite surface, Rhodocyclaceae attached to the PHBV surface, and Acidovorax attached to the suppled sludge, which highlighted that the autotrophic??? heterotrophic synergy was achieved. The difference analysis among functional genes detected by high-throughput quantitative polymerase chain reaction indicated that the surface of pyrite in the pyrite/PHBV system is the hot area of methane production, the denitrifying process, and phosphorus removal. Network analysis indicated that there was a closer connection among functional genes on the pyrite surface, also supporting the speculation that pyrite was the hot area for the interaction of various genes in the pyrite/PHBV system. The key gene co-occurrence revealed that lig, nirS, and aspA are the keystone genes for cellulose degradation, denitrification, and S cycling, respectively. These results suggested that the pyrite surface was the hot area for denitrification, phosphorus removal in the blending system with pyrite and PHBV for nitrogen and phosphorus removal.
Species are changing their elevational distributions in response to climate change, leading to biodiversity loss and changes in community structure. Yet whether native and non-native species have consistent elevational shifts remains to be evaluated. Subtropical mountains are rich in biodiversity, sensitive to climate change, and are experiencing high risks of biological invasion. Hence exploring the changes in species elevational distributions induced by climate change in subtropical mountains is an urgent need. Here, we explored the impact of climate change on the elevational distribution of seed plant species in Jinfo Mountain (Mt. Jinfo), a subtropical mountain in China with rich plant diversity. Notably, we compared the elevational redistributions of native and non-native plants in response to climate change. The results showed that the elevational centroids of native plant species moved downhill, while those of non-native plants shifted upward on average. The upper limit of native plants shifted downward, while the upper limit of non-native plants shifted upward on average. The elevational shifts of non-native plants were dominated by changes in the upper range limits, while those of native plants were affected by the lower limits. These opposite elevational shifts of native vs non-native species led to the increase in the elevational range size of the non-native plants, but decrease in the elevational range size of native plants, especially in high altitudes. The differences in the directions and magnitudes of elevational shifts between the native and non-native plants are mainly due to differences in their climate adaptation. Changes in temperature and precipitation influenced the elevational range shifts of native plants but not of non-native ones. This study provides a new perspective for understanding the elevational redistribution of native and non-native plant species in subtropical mountains, and suggests that climate change has stronger influence on native than non-native species.
The presence of brackish-saline groundwater (BSG) poses great harms for human health, agricultural and in-dustrial activity. Understanding how the major environmental features in BSG determine microbiota coalescence is crucial for groundwater monitoring optimization. Based on metabarcoding analysis of 242 PCR-amplified samples, we provided the first blueprints about distinct spatiotemporal distributions, ecological drivers and assembly processes of bacterial, archaeal and fungal communities in BSG obtained from new-constructed wells at Xiong'an New Area, China. Our study demonstrated that bacterial and archaeal communities exhibited signifi-cant spatial turnovers, while fungal community displayed the most obvious seasonal variation. Environmental filtering drove bacterial compositions more than those of archaea and fungi. Total dissolved solids (TDS), one of the most critical hydrochemical factors for salinization, had a stronger effect on bacterial spatiotemporal turn -over than on those of the other two taxonomic groups, while chemical oxygen demand (CODMn) was more significantly associated with prokaryotic community variations. Bacterial and archaeal taxa dominated the metacommunity network and connected closely, and TDS was mostly related to archaeal subnetwork topological features, suggesting a significant influence of TDS on species association patterns within archaea. Specific functional guilds like bacterial nitrite oxidation, anammox, and archaeal methanogenesis were enriched in lower-TDS habitats, while higher TDS favored bacterial communities involved in dark oxidation of sulfur compounds, fumarate respiration, and cellulolysis. Finally, we confirmed that bacterial and archaeal assembly processes were governed by determinism in each season, and that of fungi was more regulated by stochasticity. Higher TDS was speculated to lead bacterial assembly more deterministic and that of fungi more random. Together, these findings provided an integrate theoretical framework about the unique responses of the three life domains to brackish-saline stress, and had important implications for microbial ecological prediction in groundwater.
Chemical diffusion in minerals has shown great potential to quantify timescales of geological processes. The presence of chemical gradients, along with favorable temperature and time conditions, lead to the formation of measurable diffusion profiles. Temporal information can be extracted from measured diffusion profiles using either analytical or numerical solutions of Fick's second law. Currently, there is a lack of widely adopted programs for diffusion studies. In addition, the uncertainties associated with timescales derived from diffusion chronometry are critical for geological studies, but are not always robustly evaluated. In many cases, only uncertainties in curve fitting parameters and temperature are considered, whereas other uncertainties, such as those associated with the experimentally determined diffusion coefficients themselves, are rarely propagated into the calculated timescales. Ignoring these uncertainties reduces the reproducibility and intercomparability of results. In response to these challenges, we present Diffuser, a user-friendly program to standardize diffusion chronometry with transparent and robust propagation of uncertainties. Using analytical and numerical methods, our program provides an automatic, visual, and efficient curve fit to extract chronological information from diffusion profiles. The method is complemented by an algorithm to propagate all uncertainties (i.e., measurement, temperature, curve fitting, and diffusion coefficient) to derived timescales. Three examples are provided to highlight how the program can recover timescales with internal consistency, efficient computing, and easy-to-use features. Our freely available and user-friendly program will hopefully increase the accessibility and consistency of diffusion modeling and thereby to facilitate more high-quality diffusion studies.
This article reviews Chinese academic papers from the past 20 years to investigate the digital literacy of normal students of pedagogical faculties. The main body of the article concerns “student literacy, to teacher literacy, then to normal student literacy”; regarding the theme, the context is “from digital literacy, to information literacy, then to digital information teaching ability.” Under the guidance of the Chinese education administration, the digital literacy of Chinese normal students has gradually taken on the Chinese characteristics of being practice-oriented and ability-oriented. The findings of this article are as follows: (1) In terms of research trends, the digital literacy of normal students has increased overall. This has depended on the gradual in-depth understanding of its value to the academic world, which promotes in-depth academic research while also focusing on clear and continuous policy planning. (2) In terms of research themes, the digital literacy of normal students is biased toward practice and training, and there is less research on the development of digital teaching ability in specific subjects. (3) In terms of research methods, qualitative research is still the mainstream method, but increasingly, quantitative research, including surveys, is used. (4) In terms of research results, based on the current survey report data, the digital practice ability of Chinese normal students still needs improvement. The current research has indicated the direction for the future academic community and also proposed requirements for policy researchers and makers.
As emerging pollutants, microplastics (MPs) are widely distributed in water, soil and atmosphere, and have become a popularly concerned environmental and social issue. The research on atmospheric microplastics (AMPs) started later than that on the MPs in soil and water, but AMPs’ potential environmental impacts are explored in an even wider range. Based on the literatures on AMPs since 2015 as well as those about MPs in water and soil, this paper systematically reviews the distribution, source, transport of AMPS and the environmental and ecological impacts of AMPs. The results show that AMPs are distributed in global atmosphere, and have been detected in the atmosphere of urban, suburban, remote areas and indoor air. The concentrations of AMPs were detected in a range 2 to 77000 n m–2 d–1 or 0 to 1583 n m–3. The distribution characteristics of MPs in atmosphere are affected by environmental factors such as indoor and outdoor environment, underlying surface type and airflow, etc. In general, the concentration and the diversity of AMPs’ shape and composition are higher in the places near to MPs the source, but the wind, precipitation and even local animals could reshape the characters of AMPs. The sources of AMPs are mainly the production, use and recycling processes of plastic products, as well as land and sea where MPs accumulated. Studies also showed that abrasion of vehicle tires and the use of synthetic textile are major sources. What’s noteworthy is that the COVID-19 pandemic has made masks as necessities of life, which indirectly exacerbated the pollution of AMPs. The transport of MPs can occur in atmospheric environment, such as suspension, deposition and diffusion, and is affected by the morphology of MPs, wind direction, precipitation and other atmospheric factors. The diffusion of MPs in atmosphere, also known as atmospheric transport, is an important part of the global plastic cycle. AMPs’ transport path is mostly studied of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) by conducting backward trajectory simulation, and their transport volume is estimated mainly through deposition and aerodynamic model. In addition, AMPs have unique physical and chemical properties, which can affect regional atmospheric environmental quality, change regional and global climate. It could also adsorb heavy metals, organic pollutants and harmful microorganisms during transport, resulting in greater health risks to human. Also, AMPs could affect atmospheric ecosystems through food chains and providing microbial niches, and alter structure and functions of terrestrial forest and water ecosystems through deposition. There are still some unsolved scientific and technical questions. Due to the lack of standardized sampling and identification means, the past research methods on AMPs are different on sampling and physical analysis, which make information comparison difficult. The observations of AMPs’ environmental behaviors, the atmospheric transport, source attribution and trans-regional effects of AMPs are still limited. Therefore, some conclusions from laboratory researches cannot fully explain the uncertainty of in natural environment. Based on the analysis, it is suggested that future scientific research on AMPs should focus on standardization of research methods, the establishment of source list, transport mechanism and environmental and ecological impacts. It is necessary for the study of AMPs to establish a set of scientifically credible and technically feasible monitoring techniques as well. Because AMPs could be transported to different ecosystems and could enter the human body through a variety of ways, it is urgent to study the physiological and ecological status of human body and ecosystems which are continuously exposed to AMPs pollution.
BACKGROUND: The dataset providing information on the geographic distribution of Oxytropis species on the territory of Asian Russia is discussed. The data were extracted from different sources including prominent floras and check-lists, Red Data books, published research on congeneric species and authors' field observations and mainly cover less-studied, remote regions of Russia. The dataset should be of value to applied, basic and theoretical plant biologists and ecologists interested in the Oxytropis species. NEW INFORMATION: The dataset includes 5172 distribution records for 143 species and 15 subspecies of genus Oxytropis DC. (Fabaceae Lindl.) in Asian Russia. The dataset fills gaps in the distribution of locoweeds in the study area and contains precise coordinates for many of rare and endemic species.
This paper wishes to use the epigraphical record of Amastris to discuss how a sympolity founded in the Hellenistic period continued to evolve and develop additional diversity and dynamics in the Roman period. I will first discuss how literary sources describe the early history of Amastris as an integrative and cooperative space in Hellenistic northern Anatolia, then move to epigraphical sources and discuss how this trend likely continued to evolve as Amastris came under Roman rule. An important caveat must be raised beforehand. While this paper wishes to suggest that some trends such as the integrative and cooperative aspects of this locale can indeed be observed and described, the materials used for the description – both the literary tradition and the epigraphic sources – can only provide minimalist impressions of large socio-political trends, if even these at all. What I hope to achieve, despite such reservations, is to establish some baselines that can be used for asking further questions at a regional level, where additional evidence can be used to discuss integrative and cooperative dynamics across different cities.