Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and s...Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.展开更多
We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the...We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.展开更多
pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric ex...pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.展开更多
The Alectoris (Galliformes: Phasianidae) has a wide distribution range in the Palearctic region, with seven species and 27–31 subspecies that were distinguishable by minor morphological differences. The members of th...The Alectoris (Galliformes: Phasianidae) has a wide distribution range in the Palearctic region, with seven species and 27–31 subspecies that were distinguishable by minor morphological differences. The members of the genus exhibit distinct genetic structuring compatible with geography due to their inability to make long flights and ground-dwelling behaviors. In this respect, the evolutionary history of the genus and its populations is a useful tool for identifying potential cryptic refugia, dispersal corridors, and strong barriers for bird species in the Palearctic region. On the other hand, wild populations of the genus are among the bird species most affected by human activities. For this purpose, sequences from the mitochondrial D-loop and Cyt-b regions of individuals from the genus Alectoris were studied to identify the evolutionary history of the genus, determine potential cryptic species, and reveal possible hidden diversification areas in the Palearctic region. The results indicated that: the Mediterranean basin is the ancestral area of the Alectoris, there are two main diversification centers within its distribution range (Mediterranean Basin and China) of the genus, and certain micro-refugia and permanent dispersal corridors have been observed in Eastern Palaearctic region. Additionally, the results showed that the Pleistocene climatic changes acted as a species pump, playing a significant role in the diversification of lineages within the genus. Anatolia served as the ancestral area for the A. chukar and acted as a bridgehead during the species' dispersal in the inner side of the Eastern Palaearctic. High mountain ranges, monsoonal climate types, and deserts in the Eastern Palearctic played a significant role in the dispersal and diversification of the ancestral A. chukar population. Importantly, human activities appear to be the greatest evolutionary force shaping the future evolution of the genus.展开更多
Spontaneous combustion of lignite is closely related to the inherent minerals it contains, and the iron component has a remarkable influence on the combustion property of lignite. It is very important to study the inf...Spontaneous combustion of lignite is closely related to the inherent minerals it contains, and the iron component has a remarkable influence on the combustion property of lignite. It is very important to study the influence of iron component on the combustion reaction property of lignite to reveal autoignition mechanism of lignite and reduce autoignition of lignite. In this research, FeCl_(3) and Fe_(2)O_(3) were doped into demineralised lignite (SL+) by impregnation to research the effects of iron salts and iron oxides on the combustion properties of lignite. Based on the above, the effects of post-treatment method of the FeCl_(3)-doped coal samples, iron-salt hydrolysis products and heat-treated temperatures on the combustion property of lignite were researched, and the microstructures of the coal samples were characterised and analysed using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope-energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that doping with FeCl_(3) increases the combustion performance of lignite, thereby reducing the ignition temperature of lignite by approximately 112 ℃. In contrast, doping with Fe_(2)O_(3) has a weaker combustion-promoting effect. XRD and XPS characterisation indicates that iron species in the coal samples doped with iron salts are highly dispersed and exhibit the FeOOH structure, whereas iron species in the coal samples doped with Fe_(2)O_(3) exhibit the crystal form of α-Fe_(2)O_(3). Doping of lignite with FeCl_(3) and its hydrolysis product β-FeOOH reduces the ignition temperature of the coal samples. Iron species in the FeCl_(3)-doped coal samples after heat treatment at 300–500 ℃ increase the combustion property of the coal samples, whereas iron species after heat treatment at 600–900 ℃ have a much weaker or non-existent promoting effect on the combustion performance of the coal samples. The characterisation show a change in iron species in the coal samples with the rise in the heat treatment temperature. This change progresses from highly dispersed β-FeOOH below 300 ℃ to Fe_(3)O_(4) above 400 ℃. Fe_(3)O_(4) is gradually reduced, with part of it further reduced to elementary iron at the same time as grain growth. It is believed that the gradual agglomeration of Fe_(3)O_(4) and the appearance of elementary iron are the main reasons for the weakening or disappearance of the promoting effect on coal combustion.展开更多
How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the ...How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.展开更多
Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that female...Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that females use to localize and discriminate among potential mates.Thus,the acoustic structure of the advertisement call is critical for reproductive success.The acoustic structure of calls will generally divergeover evolutionary time and can be infuenced by the calls of sympatric species.While many studies have shown the infuence of geographyon contemporary call variation in populations of frogs,no study has compared the acoustic structure of frog calls across many species to askwhether we can detect an infuence of divergence time and overall geographic overlap on the differences in acoustic structure of species-typicalcalls that we observe now.To this end,we compared acoustic features of the calls of 225 species of frogs within 4 families.Furthermore,weused a behavioral assay from 1 species of frog to determine which acoustic features to prioritize in our large-scale analyses.We found evidencethat both phylogeny(time)and geography(place)relate to advertisement call acoustics albeit with large variation in these relationships acrossthe 4 families in the analysis.Overall,these results suggest that,despite the many ecological and evolutionary forces that infuence call structure,the broad forces of time and place can shape aspects of advertisement call acoustics.展开更多
Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species ...Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species concept that incorporates data from a variety of sources.In this study,we incorporated genetic,ecological,and environmental evidence to assess the extent of speciation or evolutionary divergence within a monophyletic yet dimorphic group(i.e.,clade Leucolirion consisting of six species)within the genus Lilium.This clade consists of two lineages that exhibit unexpectedly distinct perianth appearances:whitish trumpet(funnel form,encompassing four species)and orange recurved(reflex form,including two species),respectively,which are separated by completely different pollination syndromes.Transcriptome-based nuclear and plastome datasets indicate that these two lineages are isolated,with only weak ancient gene flow between them.Within each lineage,several taxa with incomplete isolation have diverged,as indicated by weak genetic structure,strong gene flow,and conflicts between nuclear and chloroplast phylogenies,especially in the trumpet lineage.Although these taxa are not entirely independent,our evidence indicates that they are diverging,with recent gene flow disappearing and multiple isolation strategies emerging,such as differences in flowering time and niche specialization.Taken together,our findings suggest that species divergence and maintenance in Lilium are driven by a combination of adaptive and non-adaptive processes,highlighting the complex interplay of historical climate changes,ecological adaptation,and gene flow in shaping biodiversity within this genus.展开更多
The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to ...The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.展开更多
Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as we...Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as well as a carrier of pollutants like heavy metals.However,the dynamic changes of bacterial communities attached to EPS and their interaction with heavy metals are still poorly unknown.In this study,a one-year field exposure experiment was conducted at an aquaculture farm near Donghai Island,in Leizhou Bay,Zhanjiang,Guangdong,in South China Sea.The bacterial communities attached to EPS MPs were examined by 16S r DNA high-throughput sequencing,and the relationships between bacterial biofilms and heavy metals were explored.The results show that there were notable seasonal variations in the bacterial diversity of EPS MPs.Species biodiversity was the highest in summer and the lowest in winter.The greatest number of bacterial species and lowest level of uniformity were observed in the spring.The bacterial community structure changed with exposure time,and the most significant difference in the 12-month group (P<0.05) was found.The dominant bacterial species attached to EPS MPs were mainly Proteobackteria and Firmicutes at the phylum level,and Pseudomonas and Exiguobacterium were dominant at the genus level.Furthermore,EPS MPs acted as transport carriers for potential pathogenic bacteria.High correlations were found between bacterial species and the total concentration of heavy metals on EPS MPs,as well as their speciation fractions.Different chemical speciation of heavy metals migrated and altered over seasons within biofilms,which would further exacerbate the ecological risks.展开更多
Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu upt...Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu uptake is controlled by natural dissolved organic Cu(DOCu)speciation(i.e.,complexed with the dissolved organic matter)that conventionally could be tested by model prediction or molecular-level characterizations in the lab,while DOCu uptake are hardly directly assessed.Thus,the new chemistrybiology insight into the mechanisms of the Cu uptake process in algae is urgent.The DOCu speciation transformation(organic DOCu to free Cu(II)ions),enzymatic reduction-induced valence change(reduction of free Cu(II)to Cu(I)ions),and algal Cu uptake at the algae-water interface are imitated.Herein,an intelligent system with DOCu colorimetric sensor is developed for real-time monitoring of newly generated Cu(I)ions.Deep learning with whole sample image-based characterization and powerful feature extraction capabilities facilitates colorimetric measurement.In this context,the Cu bioavailability with 7 kinds of organic ligands(e.g.,amino acids,organic acids,carbohydrates)can be predicted by the mimetic intelligent biosensor within 15.0min,i.e.,the DOCu uptake and speciation is successfully predicted and streamlined by the biomimetic approach.展开更多
Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow i...Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.展开更多
Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in...Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.展开更多
The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemic...The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemical mobility of radionuclides,a critical factor for predicting their migration and environmental impact.The objective of the research was to determine the uranium species in both peat and sedimentary rock samples of the sludge storage facility and the adjacent area.Laboratory analyses included XRD,XRF analysis using synchrotron radiation,and scanning electron microscopy to study the composition and properties of minerals.The uranium species were further identified using a modified Tessier sequential extraction method.The results revealed that uranium predominantly occurs in a stable silicate-bound form(up to 80%)in sedimentary rocks,indicating minimal geochemical mobility.In contrast,in peat deposits,uranium is primarily associated with manganese and iron oxides(30–60%)as well as organic matter(5–40%),with the most mobile forms constituting less than 5%.The decrease in uranium concentration with distance from the facility was attributed to sorption onto organic matter and co-precipitation with mineral compounds,manganese and iron oxides,which serve as effective natural sorbents.The findings highlight the critical role of organic matter and metal oxides in limiting uranium migration,thus identifying them as key components in the formation of natural barriers for radionuclides.These results are crucial for assessing environmental risks associated with radioactive waste management and for developing strategies to minimize the ecological impact of sludge storages.展开更多
The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether p...The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).展开更多
Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research...Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.展开更多
Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loa...Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils.In addition,the effect of zero-valent iron(ZVI)on grain As speciation accumulation in alkaline paddy soils was first investigated.The effect of rice straw biochar(SC),magnesiumloaded rice straw biochar(Mg/SC),and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissueswas investigated in a pot experiment.Addition of SC,Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%,90.3%and 100%,and inorganic As(iAs)by 35.4%,33.1%and 29.1%,respectively,and reduced Cd concentrations in porewater by 74.3%,96.5%and 96.2%,respectively.Reductions of 51.6%and 87.7%in porewater iAs concentrationswere observed with Mg/SC and ZVI amendments,but notwith SC.Dimethylarsinic acid(DMA)concentrations in porewater and grain increased by a factor of 4.9 and 3.3,respectively,with ZVI amendment.The three amendments affected grain concentrations of iAs,DMA and Cd mainly by modulating their translocation within plant and the levels of As(Ⅲ),silicon,dissolved organic carbon,iron or Cd in porewater.All three amendments(SC,Mg/SC and ZVI)have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain,although the pathways are different.展开更多
Heavy metal(loid)s contamination is a constant issue at smelting sites.It is essential to investigate the spatial distribution and migration characteristics of heavy metal(loid)s in the soil for environmental manageme...Heavy metal(loid)s contamination is a constant issue at smelting sites.It is essential to investigate the spatial distribution and migration characteristics of heavy metal(loid)s in the soil for environmental management and remediation strategies of non-ferrous smelting sites.In this study,203 soil samples from 57 sites were collected in a typical lead smelting site.The findings demonstrated that there were significant Pb,Zn,Cd,and As contamination in soil samples.The spatial distribution of heavy metal(loid)s showed strong spatial heterogeneity,the contaminated soil areas of Pb,As,Cd,and Zn were 99.5%,98.9%,85.3%,and 72.4%,respectively.Pb,Cd,and As contamination of the soil reached a depth of 5 m,which migrated from the surface to deep soil layers.The leaching contents of Zn,Pb,and As decreased obviously in 3-4 m soil layer,but the leaching content of Cd was still high,which indicated the high migration of Cd.With the increase of depth,the proportion of acid soluble fraction of heavy metal(loid)s decreased,and the residual fraction increased.The acid soluble fraction of Cd accounted for a higher proportion,and As mainly existed in reducible and residual fractions in soil.According to the calculation of the migration factor,the migration of heavy metal(loid)s in soils were ordered as Cd>Zn>Pb>As.The outcomes are advantageous for risk reduction and site remediation for non-ferrous metal smelting sites.展开更多
Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH...Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH and oxidation-reduction potential).However,their combined impacts on arsenic speciation transformation remain poorly studied.Therefore,we explored arsenic transformation and immobilization during pyrite dissolution mediated by AMD enrichment culture under different acidic pH conditions.The results for incubation and mineralogical transformation of solid residues show that in the presence of AMD enrichment culture,pH 2.0,2.5,and 3.0 are more conducive to the formation of jarosites and ferric arsenate,which could immobilize high quantities of dissolved arsenic by adsorption and coprecipitation.The pH conditions significantly affect the initial adsorption of microbial cells to the minerals and the evolution of microbial community structure,further infuencing the biodissolution of pyrite and the release and oxidation process of Fe/S.The results of Fe/S/As speciation transformation of the solid residues show that the transformation of Fe,S,and As in solution is mainly regulated by pH and potential values,which imposed significantly different effects on the formation of secondary minerals and thus arsenic oxidation and immobilization.The above results indicated that arsenic transformation is closely related to the Fe/S oxidation associated with pyrite bio-oxidation,and this correlation is critically regulated by the pH conditions of the system.展开更多
基金supported by the National Natural Science Foundation of China(Nos.32171623 and 31770548)the National Key Research and Development Program of China(Nos.2016YFD0800306 and 2017YFD0800305).
文摘Arsenic(As)pollution seriously threatens human and ecological health.Microalgal cell wall and extracellular polymeric substances(EPS)are known to interactwith As,but their roles in the As resistance,accumulation and speciation inmicroalgae remain unclear.Here,we used two strains of Chlamydomonas reinhardtii,namely CC-125(wild type)and CC-503(cell walldeficientmutant),to examine the algal growth,EPS synthesis,As adsorption,absorption and transformation under 10–1000μg/L As(III)and As(V)treatments for 96 h.In both strains,the As absorption increased after the EPS removal,but the growth,As adsorption,and transformation of C.reinhardtii declined.The CC-125 strain was more tolerant to As stress and more efficient in EPS production,As accumulation,and redox transformation than CC-503,irrespective of EPS presence or absence.Three-dimension excitation-emission matrix(3DEEM)and attenuated total reflectance infrared spectroscopy(ATR-IR)analyses showed that As was bound with functional groups in the EPS and cell wall,such as-COOH,NH and-OH in proteins,polysaccharides and amino acids.Together,this study demonstrated that EPS and cell wall acted as barriers to lower the As uptake by C.reinhardtii.However,the cell wall mutant strain wasmore susceptible to As toxicity due to lower EPS induction and higher As absorption.
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada.
文摘We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.
文摘pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.
基金upported by Scientific and Technological Research Council of Turkey(TUBITAK)under the Grant Number 116Z326Akdeniz University Scientific Research Projects Coordination Unit under project No.FDK-2017-3022.
文摘The Alectoris (Galliformes: Phasianidae) has a wide distribution range in the Palearctic region, with seven species and 27–31 subspecies that were distinguishable by minor morphological differences. The members of the genus exhibit distinct genetic structuring compatible with geography due to their inability to make long flights and ground-dwelling behaviors. In this respect, the evolutionary history of the genus and its populations is a useful tool for identifying potential cryptic refugia, dispersal corridors, and strong barriers for bird species in the Palearctic region. On the other hand, wild populations of the genus are among the bird species most affected by human activities. For this purpose, sequences from the mitochondrial D-loop and Cyt-b regions of individuals from the genus Alectoris were studied to identify the evolutionary history of the genus, determine potential cryptic species, and reveal possible hidden diversification areas in the Palearctic region. The results indicated that: the Mediterranean basin is the ancestral area of the Alectoris, there are two main diversification centers within its distribution range (Mediterranean Basin and China) of the genus, and certain micro-refugia and permanent dispersal corridors have been observed in Eastern Palaearctic region. Additionally, the results showed that the Pleistocene climatic changes acted as a species pump, playing a significant role in the diversification of lineages within the genus. Anatolia served as the ancestral area for the A. chukar and acted as a bridgehead during the species' dispersal in the inner side of the Eastern Palaearctic. High mountain ranges, monsoonal climate types, and deserts in the Eastern Palearctic played a significant role in the dispersal and diversification of the ancestral A. chukar population. Importantly, human activities appear to be the greatest evolutionary force shaping the future evolution of the genus.
基金support from the National Natural Science Foundation of China(22368038,21968021,22308048)Science and Technology Plan Project of Inner Mongolia(2020GG0289)+1 种基金Natural Science Foundation of Inner Mongolia(2019MS02025)Science Fund for Distinguished Young Scholars of Inner Mongolia(2022JQ04).
文摘Spontaneous combustion of lignite is closely related to the inherent minerals it contains, and the iron component has a remarkable influence on the combustion property of lignite. It is very important to study the influence of iron component on the combustion reaction property of lignite to reveal autoignition mechanism of lignite and reduce autoignition of lignite. In this research, FeCl_(3) and Fe_(2)O_(3) were doped into demineralised lignite (SL+) by impregnation to research the effects of iron salts and iron oxides on the combustion properties of lignite. Based on the above, the effects of post-treatment method of the FeCl_(3)-doped coal samples, iron-salt hydrolysis products and heat-treated temperatures on the combustion property of lignite were researched, and the microstructures of the coal samples were characterised and analysed using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope-energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrate that doping with FeCl_(3) increases the combustion performance of lignite, thereby reducing the ignition temperature of lignite by approximately 112 ℃. In contrast, doping with Fe_(2)O_(3) has a weaker combustion-promoting effect. XRD and XPS characterisation indicates that iron species in the coal samples doped with iron salts are highly dispersed and exhibit the FeOOH structure, whereas iron species in the coal samples doped with Fe_(2)O_(3) exhibit the crystal form of α-Fe_(2)O_(3). Doping of lignite with FeCl_(3) and its hydrolysis product β-FeOOH reduces the ignition temperature of the coal samples. Iron species in the FeCl_(3)-doped coal samples after heat treatment at 300–500 ℃ increase the combustion property of the coal samples, whereas iron species after heat treatment at 600–900 ℃ have a much weaker or non-existent promoting effect on the combustion performance of the coal samples. The characterisation show a change in iron species in the coal samples with the rise in the heat treatment temperature. This change progresses from highly dispersed β-FeOOH below 300 ℃ to Fe_(3)O_(4) above 400 ℃. Fe_(3)O_(4) is gradually reduced, with part of it further reduced to elementary iron at the same time as grain growth. It is believed that the gradual agglomeration of Fe_(3)O_(4) and the appearance of elementary iron are the main reasons for the weakening or disappearance of the promoting effect on coal combustion.
基金supported by grants from the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk0205 to Lin Xia,No.2021xjkk0604 to Jilong Cheng)the National Natural Science Foundation of China(32170416 to Qisen Yang,31900325 to Jilong Cheng)+1 种基金the Joint Fund of National Natural Science Foundation of China(U2003203 to Lin Xia)the Key Laboratory of Zoological Systematics and Evolution of the Chinese Academy of Sciences(Y229YX5105 to Qisen Yang).
文摘How ecological and evolutionary factors affect small mammal diversity in arid regions remains largely unknown.Here,we combined the largest phylogeny and occurrence dataset of Gerbillinae desert rodents to explore the underlying factors shaping present-day distribution patterns.In particular,we analyzed the relative contributions of ecological and evolutionary factors on their species diversity using a variety of models.Additionally,we inferred the ancestral range and possible dispersal scenarios and estimated the diversification rate of Gerbillinae.We found that Gerbillinae likely originated in the Horn of Africa in the Middle Miocene and then dispersed and diversified across arid regions in northern and southern Africa and western and central Asia,forming their current distribution pattern.Multiple ecological and evolutionary factors jointly determine the spatial pattern of Gerbillinae diversity,but evolutionary factors(evolutionary time and speciation rate)and habitat filtering were the most important in explaining the spatial variation in species richness.Our study enhances the understanding of the diversity patterns of small mammals in arid regions and highlights the importance of including evolutionary factors when interpreting the mechanisms underlying large-scale species diversity patterns.
基金funded through a grant from the NationalScience Foundation(IOS-1914646)the SmithsonianInstitute Postdoctoral Fellowship program.
文摘Acoustic communication signals are important for species recognition and mate attraction across numerous taxa.For instance,most of thethousands of species of frogs have a species-specifc advertisement call that females use to localize and discriminate among potential mates.Thus,the acoustic structure of the advertisement call is critical for reproductive success.The acoustic structure of calls will generally divergeover evolutionary time and can be infuenced by the calls of sympatric species.While many studies have shown the infuence of geographyon contemporary call variation in populations of frogs,no study has compared the acoustic structure of frog calls across many species to askwhether we can detect an infuence of divergence time and overall geographic overlap on the differences in acoustic structure of species-typicalcalls that we observe now.To this end,we compared acoustic features of the calls of 225 species of frogs within 4 families.Furthermore,weused a behavioral assay from 1 species of frog to determine which acoustic features to prioritize in our large-scale analyses.We found evidencethat both phylogeny(time)and geography(place)relate to advertisement call acoustics albeit with large variation in these relationships acrossthe 4 families in the analysis.Overall,these results suggest that,despite the many ecological and evolutionary forces that infuence call structure,the broad forces of time and place can shape aspects of advertisement call acoustics.
基金supported by the National Natural Science Foundation of China(NSFC Grant Nos.32171605,31770406)Natural Science Foundation of Sichuan Province(Grant No.2023NSFSC0141)to Y.D.Gao.
文摘Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species concept that incorporates data from a variety of sources.In this study,we incorporated genetic,ecological,and environmental evidence to assess the extent of speciation or evolutionary divergence within a monophyletic yet dimorphic group(i.e.,clade Leucolirion consisting of six species)within the genus Lilium.This clade consists of two lineages that exhibit unexpectedly distinct perianth appearances:whitish trumpet(funnel form,encompassing four species)and orange recurved(reflex form,including two species),respectively,which are separated by completely different pollination syndromes.Transcriptome-based nuclear and plastome datasets indicate that these two lineages are isolated,with only weak ancient gene flow between them.Within each lineage,several taxa with incomplete isolation have diverged,as indicated by weak genetic structure,strong gene flow,and conflicts between nuclear and chloroplast phylogenies,especially in the trumpet lineage.Although these taxa are not entirely independent,our evidence indicates that they are diverging,with recent gene flow disappearing and multiple isolation strategies emerging,such as differences in flowering time and niche specialization.Taken together,our findings suggest that species divergence and maintenance in Lilium are driven by a combination of adaptive and non-adaptive processes,highlighting the complex interplay of historical climate changes,ecological adaptation,and gene flow in shaping biodiversity within this genus.
基金supported by the Natural Science Foundation of Fujian Province(No.2020J06008)for Distinguished Young Scholarsthe Fujian Provincial Central Guided Local Science and Technology Development Special Project(No.2022L3078).
文摘The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.
基金Supported by the Hainan Province Science and Technology Special Fund (No.ZDYF2022SHFZ317)the Guangdong Province Key Laboratory of Applied Marine Biology (No.2023B1212060047)the Program for Scientific Research Start-up Funds of Guangdong Ocean University (No.060302332301)。
文摘Expanded polystyrene (EPS) is a common type of microplastics (MPs) often found in coastal areas especially aquaculture areas.It is considered as an important site for microbial colonization and biofilm formation,as well as a carrier of pollutants like heavy metals.However,the dynamic changes of bacterial communities attached to EPS and their interaction with heavy metals are still poorly unknown.In this study,a one-year field exposure experiment was conducted at an aquaculture farm near Donghai Island,in Leizhou Bay,Zhanjiang,Guangdong,in South China Sea.The bacterial communities attached to EPS MPs were examined by 16S r DNA high-throughput sequencing,and the relationships between bacterial biofilms and heavy metals were explored.The results show that there were notable seasonal variations in the bacterial diversity of EPS MPs.Species biodiversity was the highest in summer and the lowest in winter.The greatest number of bacterial species and lowest level of uniformity were observed in the spring.The bacterial community structure changed with exposure time,and the most significant difference in the 12-month group (P<0.05) was found.The dominant bacterial species attached to EPS MPs were mainly Proteobackteria and Firmicutes at the phylum level,and Pseudomonas and Exiguobacterium were dominant at the genus level.Furthermore,EPS MPs acted as transport carriers for potential pathogenic bacteria.High correlations were found between bacterial species and the total concentration of heavy metals on EPS MPs,as well as their speciation fractions.Different chemical speciation of heavy metals migrated and altered over seasons within biofilms,which would further exacerbate the ecological risks.
基金supported by the National Natural Science Foundation of China(No.22074058,S.Li).
文摘Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu uptake is controlled by natural dissolved organic Cu(DOCu)speciation(i.e.,complexed with the dissolved organic matter)that conventionally could be tested by model prediction or molecular-level characterizations in the lab,while DOCu uptake are hardly directly assessed.Thus,the new chemistrybiology insight into the mechanisms of the Cu uptake process in algae is urgent.The DOCu speciation transformation(organic DOCu to free Cu(II)ions),enzymatic reduction-induced valence change(reduction of free Cu(II)to Cu(I)ions),and algal Cu uptake at the algae-water interface are imitated.Herein,an intelligent system with DOCu colorimetric sensor is developed for real-time monitoring of newly generated Cu(I)ions.Deep learning with whole sample image-based characterization and powerful feature extraction capabilities facilitates colorimetric measurement.In this context,the Cu bioavailability with 7 kinds of organic ligands(e.g.,amino acids,organic acids,carbohydrates)can be predicted by the mimetic intelligent biosensor within 15.0min,i.e.,the DOCu uptake and speciation is successfully predicted and streamlined by the biomimetic approach.
基金supported by the National Natural Science Foundation of China(32370386,32070372,and 32200295)Science Foundation for Distinguished Young Scholars of Shaanxi Province(2023-JC-JQ-22)+4 种基金Basic Research Project of Shaanxi Academy of Fundamental Science(22JHZ005)Shaanxi Key Research and Development Program(2024NC-YBXM-064)Science and Technology Program of Shaanxi Academy of Science(2023K-49,2023K-26,and 2019K-06)Shaanxi Forestry Science and Technology Innovation Key Project(SXLK2023-02-20)Qinling Hundred Talents Project of Shaanxi Academy of Science(Y23Z619F17).
文摘Intraspecific genetic variance and gene flow can support the adaptive evolution of species challenged by climate shifts or novel environmental conditions.Less well understood is how genome organization and gene flow interact in closely related species during evolutionary divergence and differentiation.Here we conducted genomic footprint analyses to determine how three species of Pterocarya(P.stenoptera,P.hupehensis,and P.macroptera),which are sympatric but occupy different elevational niches,adapted to the heterogeneous environment of the Qinling-Daba Mountains,China.We identified candidate genes for environmental adaptation(i.e.,PIEZO1,WRKY39,VDAC3,CBL1,and RAF),and also identified regions of gene introgression between P.hupehensis and P.macroptera that show lower genetic load and higher genetic diversity than the rest of their genomes.The same introgressed regions are notably situated in areas of minimal genetic divergence yet they are characterized by elevated recombination rates.We also identified candidate genes within these introgressed regions related to environmental adaptation(TPLC2,CYCH;1,LUH,bHLH112,GLX1,TLP-3,and ABC1).Our findings have thus clarified the important role of gene flow in ecological adaptation and revealed genomic signatures of past introgression.Together,these findings provide a stronger theoretical basis for understanding the ecological adaptation and conservation of Quaternary relict woody plants in East Asia.
基金supported by the National Natural Science Foundation of China(32171816)T4F program Sweden.
文摘Hybridization is a driving force in ecological transitions and speciation,yet direct evidence linking it to adaptive differentiation in natural systems remains limited.This study evaluates the role of hybridization in the speciation of Pinus densata,a keystone forest species on the southeastern Tibetan Plateau.By creating artificialinterspecificF1s and a long-term common garden experiment on the plateau,we provide in situ assessments on 44 growth and physiological traits across four seasons,along with RNA sequencing.We found significantphenotypic divergence between P.densata and its putative parental species P.tabuliformis and P.yunnanensis,with P.densata demonstrating superior growth and dynamic balance between photosynthesis and photoprotection.The F1s closely resembled P.densata in most traits.Gene expression revealed 19%–10%of 34,000 examined genes as differentially expressed in P.densata and F1s relative to mid-parent expression values.Both additive(4%)and non-additive gene actions(5%–6%in F1s,10%–12%in P.densata)were common,while transgressive expression occurred more frequently in the stabilized natural hybrids,illustrating transcriptomic reprogramming brought by hybridization and further divergence by natural selection.We provide compelling evidence for hybridization-derived phenotypic divergence at both physiological and gene expression levels that could have contributed to the adaptation of P.densata to high plateau habitat where both parental species have low fitness.The altered physiology and gene expression in hybrids serve both as a substrate for novel ecological adaptation and as a mechanism for the initiation of reproductive isolation.
基金supported by the Russian Science Foundation grant number 23-27-00362,https://rscf.ru/en/project/23-27-00362/.
文摘The study aims to investigate uranium species in the sediments of the natural-technogenic system within a sludge storage facility in Russia.The relevance of this work is underscored by the need to assess the geochemical mobility of radionuclides,a critical factor for predicting their migration and environmental impact.The objective of the research was to determine the uranium species in both peat and sedimentary rock samples of the sludge storage facility and the adjacent area.Laboratory analyses included XRD,XRF analysis using synchrotron radiation,and scanning electron microscopy to study the composition and properties of minerals.The uranium species were further identified using a modified Tessier sequential extraction method.The results revealed that uranium predominantly occurs in a stable silicate-bound form(up to 80%)in sedimentary rocks,indicating minimal geochemical mobility.In contrast,in peat deposits,uranium is primarily associated with manganese and iron oxides(30–60%)as well as organic matter(5–40%),with the most mobile forms constituting less than 5%.The decrease in uranium concentration with distance from the facility was attributed to sorption onto organic matter and co-precipitation with mineral compounds,manganese and iron oxides,which serve as effective natural sorbents.The findings highlight the critical role of organic matter and metal oxides in limiting uranium migration,thus identifying them as key components in the formation of natural barriers for radionuclides.These results are crucial for assessing environmental risks associated with radioactive waste management and for developing strategies to minimize the ecological impact of sludge storages.
基金supported by the National Natural Science Foundation of China(No.32161143024,31970405)Iran National Science Foundation,Iran-China(INSF-NSFC)joint project(No.4002006).
文摘The biological species concept defines species as groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups(Mayr,1942).Reproductive isolation,whether prezygotic or postzygotic,plays a central role in maintaining species boundaries.However,hybridization between closely related taxa can challenge these boundaries and provide insight into speciation,gene flow,and evolutionary processes(Coyne and Orr,2004).
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs Program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada。
文摘Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.
基金supported by the National Key Research and Development Program of China(No.2021YFC1809205)the Beijing Natural Science Foundation(No.8232029)the National Natural Science Foundation of China(No.41501336).
文摘Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils.In addition,the effect of zero-valent iron(ZVI)on grain As speciation accumulation in alkaline paddy soils was first investigated.The effect of rice straw biochar(SC),magnesiumloaded rice straw biochar(Mg/SC),and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissueswas investigated in a pot experiment.Addition of SC,Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%,90.3%and 100%,and inorganic As(iAs)by 35.4%,33.1%and 29.1%,respectively,and reduced Cd concentrations in porewater by 74.3%,96.5%and 96.2%,respectively.Reductions of 51.6%and 87.7%in porewater iAs concentrationswere observed with Mg/SC and ZVI amendments,but notwith SC.Dimethylarsinic acid(DMA)concentrations in porewater and grain increased by a factor of 4.9 and 3.3,respectively,with ZVI amendment.The three amendments affected grain concentrations of iAs,DMA and Cd mainly by modulating their translocation within plant and the levels of As(Ⅲ),silicon,dissolved organic carbon,iron or Cd in porewater.All three amendments(SC,Mg/SC and ZVI)have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain,although the pathways are different.
基金supported by the National Key Research and Development Program of China (No.2019YFC1803604)the National Natural Science Foundation of China (No.42177392).
文摘Heavy metal(loid)s contamination is a constant issue at smelting sites.It is essential to investigate the spatial distribution and migration characteristics of heavy metal(loid)s in the soil for environmental management and remediation strategies of non-ferrous smelting sites.In this study,203 soil samples from 57 sites were collected in a typical lead smelting site.The findings demonstrated that there were significant Pb,Zn,Cd,and As contamination in soil samples.The spatial distribution of heavy metal(loid)s showed strong spatial heterogeneity,the contaminated soil areas of Pb,As,Cd,and Zn were 99.5%,98.9%,85.3%,and 72.4%,respectively.Pb,Cd,and As contamination of the soil reached a depth of 5 m,which migrated from the surface to deep soil layers.The leaching contents of Zn,Pb,and As decreased obviously in 3-4 m soil layer,but the leaching content of Cd was still high,which indicated the high migration of Cd.With the increase of depth,the proportion of acid soluble fraction of heavy metal(loid)s decreased,and the residual fraction increased.The acid soluble fraction of Cd accounted for a higher proportion,and As mainly existed in reducible and residual fractions in soil.According to the calculation of the migration factor,the migration of heavy metal(loid)s in soils were ordered as Cd>Zn>Pb>As.The outcomes are advantageous for risk reduction and site remediation for non-ferrous metal smelting sites.
基金supported by the National Natural Science Foundation of China (NSFC) (No.41830318)the Joint Funds of the NSFC-DFG (No.51861135305)。
文摘Arsenic(As)speciation transformation in acid mine drainage(AMD)is comprehensively affected by biological and abiotic factors,such as microbially mediated Fe/S redox reactions and changes in environmental conditions(pH and oxidation-reduction potential).However,their combined impacts on arsenic speciation transformation remain poorly studied.Therefore,we explored arsenic transformation and immobilization during pyrite dissolution mediated by AMD enrichment culture under different acidic pH conditions.The results for incubation and mineralogical transformation of solid residues show that in the presence of AMD enrichment culture,pH 2.0,2.5,and 3.0 are more conducive to the formation of jarosites and ferric arsenate,which could immobilize high quantities of dissolved arsenic by adsorption and coprecipitation.The pH conditions significantly affect the initial adsorption of microbial cells to the minerals and the evolution of microbial community structure,further infuencing the biodissolution of pyrite and the release and oxidation process of Fe/S.The results of Fe/S/As speciation transformation of the solid residues show that the transformation of Fe,S,and As in solution is mainly regulated by pH and potential values,which imposed significantly different effects on the formation of secondary minerals and thus arsenic oxidation and immobilization.The above results indicated that arsenic transformation is closely related to the Fe/S oxidation associated with pyrite bio-oxidation,and this correlation is critically regulated by the pH conditions of the system.
