Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advecti...Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications.展开更多
Amyotrophic lateral sclerosis is a very disabling disease due to the degeneration of motor neurons.Symptoms include muscle weakness and atrophy,spasticity,and progressive paralysis.Currently,there is no treatment to r...Amyotrophic lateral sclerosis is a very disabling disease due to the degeneration of motor neurons.Symptoms include muscle weakness and atrophy,spasticity,and progressive paralysis.Currently,there is no treatment to reverse damage to motor neurons and cure amyotrophic lateral sclerosis.The only two treatments actually approved,riluzole and edaravone,have shown mitigated beneficial effects.The difficulty to find a cure lies in the complexity and multifaceted pattern of amyotrophic lateral sclerosis pathogenesis.Among mechanisms,abnormal RNA metabolism,nucleocytoplasmic transport defects,accumulation of unfolded protein,and mitochondrial dysfunction would in fine induce oxidative damage and vice versa.A potent therapeutic strategy will be to find molecules that break this vicious circle.Sharpening the nuclear factor erythroid-2 related factor 2 signaling may fulfill this objective since nuclear factor erythroid-2 related factor 2 has a multitarget profile controlling antioxidant defense,mitochondrial functioning,and inflammation.We here discuss the interest of developing nuclear factor erythroid-2 related factor 2-based therapy in regard to the pathophysiological mechanisms and we provide a general overview of the attempted clinical assays in amyotrophic lateral sclerosis.展开更多
This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertoo...This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.展开更多
Peanut is a worldwide oilseed crop and the need to assess germplasm in a non-destructive manner is important for seed nutritional breeding.In this study,Near Infrared Spectroscopy(NIRS)was applied to rapidly assess ge...Peanut is a worldwide oilseed crop and the need to assess germplasm in a non-destructive manner is important for seed nutritional breeding.In this study,Near Infrared Spectroscopy(NIRS)was applied to rapidly assess germplasm variability from whole seed of 699 samples,field-collected and assembled in four genetic and environmentbased sets:one set of 300 varieties of a core-collection and three sets of 133 genotypes of an interspecific population,evaluated in three environments in a large spatial scale of two countries,Mbalmayo and Bafia in Cameroon and Nioro in Senegal,under rainfed conditions.NIR elemental spectra were gathered on six subsets of seeds of each sample,after three rotation scans,with a spectral resolution of 16 cm-1over the spectral range of867 nm to 2530 nm.Spectra were then processed by principal component analysis(PCA)coupled with Partial least squares-discriminant analysis(PLS-DA).As results,a huge variability was found between varieties and genotypes for all NIR wavelength within and between environments.The magnitude of genetic variation was particularly observed at 11 relevant wavelengths such as 1723 nm,usually related to oil content and fatty acid composition.PCA yielded the most chemical attributes in three significant PCs(i.e.,eigenvalues>10),which together captured 93%of the total variation,revealing genetic and environment structure of varieties and genotypes into four clusters,corresponding to the four samples sets.The pattern of genetic variability of the interspecific population covers,remarkably half of spectrum of the core-collection,turning out to be the largest.Interestingly,a PLS-DA model was developed and a strong accuracy of 99.6%was achieved for the four sets,aiming to classify each seed sample according to environment origin.The confusion matrix achieved for the two sets of Bafia and Nioro showed 100%of instances classified correctly with 100%at both sensitivity and specificity,confirming that their seed quality was different from each other and all other samples.Overall,NIRS chemometrics is useful to assess and distinguish seeds from different environments and highlights the value of the interspecific population and core-collection,as a source of nutritional diversity,to support the breeding efforts.展开更多
Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and c...Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and categorised storage for enterprises,future trading prices,and policy planning.The use of remote sensing data with extensive spatial coverage demonstrates some potential in predicting crop quality traits.Many studies have also proposed models and methods for predicting such traits based on multiplatform remote sensing data.In this paper,the key quality traits that are of interest to producers and consumers are introduced.The literature related to grain quality prediction was analyzed in detail,and a review was conducted on remote sensing platforms,commonly used methods,potential gaps,and future trends in crop quality prediction.This review recommends new research directions that go beyond the traditional methods and discusses grain quality retrieval and the associated challenges from the perspective of remote sensing data.展开更多
Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen stora...Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.展开更多
Sesame(Sesamum indicum L.) plays a crucial role in Ethiopian agriculture,serving both subsistence and commercial purposes.However,our understanding of the extensive genetic diversity and population structure of Ethiop...Sesame(Sesamum indicum L.) plays a crucial role in Ethiopian agriculture,serving both subsistence and commercial purposes.However,our understanding of the extensive genetic diversity and population structure of Ethiopian sesame remains limited.To address this knowledge gap,we genotyped 368 Ethiopian sesame germplasms,categorizing into four distinct breeding groups:Accessions,landraces,improved varieties,and wild types,using a comprehensive set of 28 polymorphic markers,including 23 simple sequence repeat(SSR) and five Insertion-Deletion(InDel) markers.These markers ensured robust genomic representation,with at least two markers per linkage group.Our results unveiled substantial genetic diversity,identifying a total of 535 alleles across all accessions.On average,each locus displayed 8.83 alleles,with observed and expected heterozygosity values of 0.30 and 0.36,respectively.Gene Diversity and Polymorphic Information Content(PIC) were recorded at 0.37 and 0.35.The percentage of polymorphic loci varied significantly among breeding groups,ranging from8.00% to 82.40%,indicating high diversity in accessions(82.4%),moderate diversity in improved varieties(31.20%) and landraces(29.60%),and limited diversity in wild types(8.00).Analysis of Molecular Variance(AMOVA) results emphasized significant genetic differentiation among populations,with substantial diversity(P<0.001) within each population.Approximately 8% of the entire genetic diversity could be attributed to distinctions among populations,while the larger proportion of genetic diversity(92%) resided within each individual sesame population,showcasing heightened diversity within each group.Our study’s findings received support from both Bayesian clustering and Neighbor-joining(NJ) analysis,reaffirming the credibility of our genetic structure insights.Notably,Population structure analysis at its highest Δk value(k=2) revealed the existence of two primary genetic clusters,further subdivided into four sub-populations at k=4.Similarly,NJ analysis identified two prominent clusters,each displaying additional sub-clustering.In conclusion,our research provides a comprehensive understanding of genetic groups,subpopulations,and overall diversity within Ethiopian sesame populations.These findings underscore the significant genetic diversity and population structure within Ethiopian sesame germplasm collections.This genetic richness holds promise for breeding and conservation efforts,highlighting the importance of preserving genetic diversity to ensure adaptation to changing environments and meet the needs of farmers and consumers.展开更多
The family Alaudidae,larks,comprises 93-100 species(depending on taxonomy)that are widely distributed across Africa and Eurasia,with single species extending their ranges to North and northernmost South America and Au...The family Alaudidae,larks,comprises 93-100 species(depending on taxonomy)that are widely distributed across Africa and Eurasia,with single species extending their ranges to North and northernmost South America and Australia.A decade-old molecular phylogeny,comprising~80%of the species,revealed multiple cases of parallel evolution and large variation in rates of morphological evolution,which had misled taxonomists into creating many non-monophyletic genera.Here,we reconstruct the phylogeny of the larks,using a dataset covering one mitochondrial and 16 nuclear loci and comprising all except one of the currently recognised species as well as several recently proposed new species(in total 133 taxa;not all loci available for all species).We provide additional support using genome-wide markers to infer a genus-level phylogeny based on near-complete generic sampling(in total 51 samples of 44 taxa across 40 species).Our results confirm the previous findings of rampant morphological convergence and divergence,and reveal new cases of paraphyletic genera.We propose a new subfamily classification,and also that the genus Mirafra is divided into four genera to produce a more balanced generic classification of the Alaudidae.Our study supports recently proposed species splits as well as some recent lumps,while also questioning some of the latter.This comprehensive phylogeny will form an important basis for future studies,such as comparative studies of lark natural history,ecology,evolution and conservation.展开更多
Agroecosystems in the Senegalese groundnut basin experience long periods of high temperatures and drought, which disrupt the stability of soil microbial communities. This study evaluated how that stability is affected...Agroecosystems in the Senegalese groundnut basin experience long periods of high temperatures and drought, which disrupt the stability of soil microbial communities. This study evaluated how that stability is affected by homefields and outfields’ agricultural practices and the duration of heat stress. Specifically, we collected soils from organically farmed fields that receive continual high inputs of manure (homefields), and from fields that are rarely manured (outfields). Soil samples were submitted to artificial heat stress at 60°C for 3, 14, and 28 days, followed by 28 days of recovery at 28°C. We examined the functional stability of microbial communities by quantifying C mineralization, and characterized the stability of the communities’ taxonomic compositions via high-throughput DNA sequencing. We found that the microbial communities have a low resistance to heat stress in soils from both types of fields. However, the manuring practice does affect how the functional stability of microbial communities responds to different durations of heat stress. Although functional stability was not recovered fully in either soil, microbial community resilience seemed to be greater in homefield soils. Differences in manuring practices also affected the structural taxonomic stability of microbial communities: relative abundances of Bacilli, Chloroflexia, Actinobacteria and Sordariomycetes increased in the homefield stressed-soils, but decreased significantly in outfield soils. In contrast, relative abundances of α-Proteobacteria, γ-Proteobacteria and Eurotiomycetes increased significantly in outfield stressed-soils, while decreasing significantly in the homefield soils. Relative abundances of Bacilli changed little in outfield soils, indicating that this taxon is resistant to heat stress. In summary, the microbial communities’ capacities to resist heat stress and recover from it depend upon the organic richness of the soil (i.e., manuring practice) and the adaptation of soil microbes to environmental conditions.展开更多
Despite previous reports on the genotypic variation of architectural and functional traits in fruit trees,phenotyping large populations in the field remains challenging.In this study,we used high-throughput phenotypin...Despite previous reports on the genotypic variation of architectural and functional traits in fruit trees,phenotyping large populations in the field remains challenging.In this study,we used high-throughput phenotyping methods on an apple tree core-collection(1000 individuals)grown under contrasted watering regimes.First,architectural phenotyping was achieved using T-LiDAR scans for estimating convex and alpha hull volumes and the silhouette to total leaf area ratio(STAR).Second,a semi-empirical index(IPL)was computed from chlorophyll fluorescence measurements,as a proxy for leaf photosynthesis.Last,thermal infrared and multispectral airborne imaging was used for computing canopy temperature variations,water deficit,and vegetation indices.All traits estimated by these methods were compared to low-throughput in planta measurements.Vegetation indices and alpha hull volumes were significantly correlated with tree leaf area and trunk cross sectional area,while IPL values showed strong correlations with photosynthesis measurements collected on an independent leaf dataset.By contrast,correlations between stomatal conductance and canopy temperature estimated from airborne images were lower,emphasizing discrepancies across measurement scales.High heritability values were obtained for almost all the traits except leaf photosynthesis,likely due to large intra-tree variation.Genotypic means were used in a clustering procedure that defined six classes of architectural and functional combinations.Differences between groups showed several combinations between architectural and functional traits,suggesting independent genetic controls.This study demonstrates the feasibility and relevance of combining multi-scale high-throughput methods and paves the way to explore the genetic bases of architectural and functional variations in woody crops in field conditions.展开更多
There is an increasing interest in developing nanoparticles with diverse biologic activities.To this end,we prepared 10 to 15 nm silver nanoparticles(AgNP)from native isolates of Trichoderma atroviride.Within this stu...There is an increasing interest in developing nanoparticles with diverse biologic activities.To this end,we prepared 10 to 15 nm silver nanoparticles(AgNP)from native isolates of Trichoderma atroviride.Within this study,endophytic fungi hosted four medicinal plants in Saint Katherine Protectorate,South Sinai,Egypt have been isolated by surface sterilization technique on four isolation media.Ten species,based on their frequency of occurrence,out of twenty recovered taxa were tested for their capability to synthesize extracellular AgNPs.Trichoderma atroviride hosted Chiliadenus montanus was found to be the best candidate for the production of mycogenic AgNPs among all examined species.The mycosynthesized AgNPs were compared with chemically synthesized and characterized using Ultraviolet-visible(UV-vis)spectroscopy,Raman spectroscopy,X-ray diffraction(XRD)and high-resolution transmission electron microscopy(HRTEM)techniques.The HRTEM result showed the distribution of spherical AgNPs ranging from 10 to 15 nm.Trichoderma atroviride isolate was subjected to sequencing for confirmation of phenotypic identification.The internal transcribed spacer(ITS)1-5.8 s-ITS2 rDNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number MH283876 in the NCBI Database.Antibacterial,anticandidal and antifungal effects of chemically and mycosynthesized AgNPs were examined at various concentrations in vitro against six pathogenic bacteria and 4 pathogenic fungi by agar well diffusion technique.Standard antibiotics;Gentamicin,Amoxicillin,Clotrimazole,and Nystatin at 5μg/disk were taken as positive controls,while 5%DMSO was used as the negative control.Our data revealed that the application of mycogenic AgNPs at a concentration of 100 ppm resulted in maximum inhibition of pathogenic bacteria and fungi.These data suggest that AgNPs from native isolates of Trichoderma atroviride(MH283876)offer a source of rapid synthesis of eco-friendly,economical biomaterials that show antimicrobial activities.展开更多
Mango anthracnose disease forms typical irregular-shaped black necrotic spots on the fruit peel of mature fruit and is caused by <i>Colletotrichum gloeosporioides</i>. In order to improve the disease contr...Mango anthracnose disease forms typical irregular-shaped black necrotic spots on the fruit peel of mature fruit and is caused by <i>Colletotrichum gloeosporioides</i>. In order to improve the disease control with a limited use of fungicides, new microbial agents able to limit the growth of the pathogen were searched in the indigenous natural flora of mango surface. In order to find a suitable biocontrol agent, a screening was applied to 305 epiphytic bacteria isolated from the carposphere of 17 mango cultivars sampled from eight locations on Reunion Island. The screening approach involved a first step based on the ability of the isolates to form a biofilm, to grow under fruit storage conditions, and to interfere with the development of <i>C. gloeosporioides</i>. In a second step, the capability of selected isolates to limit <i>C. gloeosporioides in vitro</i> mycelial growth and conidia germination was assessed and species identified. The most effective bacteria belonged to the <i>Enterobacter</i>, <i>Pantoea</i>, <i>Kosakonia</i> and <i>Leuconostoc</i> genera, but for some of them, their safe use has to be demonstrated. Efficacy <i>in vivo</i>, performed on wounded mature mango fruit, was limited, probably because of the wounding inoculation strategy favoring the pathogen. Future biocontrol treatments should focus on preharvest applications to enhance the protective benefit.展开更多
Initially,the Sigma-1 receptor(S1R)was incorrectly categorized as one of the opioid receptors.But it has since become clear that S1R is a non-opioid non-phencyclidine receptor with molecular chaperone activity.S1R is ...Initially,the Sigma-1 receptor(S1R)was incorrectly categorized as one of the opioid receptors.But it has since become clear that S1R is a non-opioid non-phencyclidine receptor with molecular chaperone activity.S1R is a 223 amino-acid long protein that shares no clear homology with any other known mammalian proteins,its closest homolog being the fungal ERG2 sterol isomerase.Even its pharmacological counterpart,the Sigma-2 receptor that was only recently cloned,is genetically distinct.S1R is more likely considered as an atypical ligand-modulated chaperone protein.S1R is widely expressed in many organs including brain where its function has mainly been explored.展开更多
Our common home,planet Earth,is inhabited by more than 7 billion human beings.The average life expectancy currently estimated for men is^69 years,with strong differences among countries.Currently,neurodegenerative dis...Our common home,planet Earth,is inhabited by more than 7 billion human beings.The average life expectancy currently estimated for men is^69 years,with strong differences among countries.Currently,neurodegenerative diseases are currently the leading cause of death and disability worldwide.In clinical use and neuroscience research,a solution for an effective diagnosis is in progress,but a prophylactic treatment to counteract this long-lasting plague for humanity is still unidentified.展开更多
We propose a p-multilevel preconditioner for hybrid high-order(HHO)discretizations of the Stokes equation,numerically assess its performance on two variants of the method,and compare with a classical discontinuous Gal...We propose a p-multilevel preconditioner for hybrid high-order(HHO)discretizations of the Stokes equation,numerically assess its performance on two variants of the method,and compare with a classical discontinuous Galerkin scheme.An efficient implementa-tion is proposed where coarse level operators are inherited using L2-orthogonal projec-tions defined over mesh faces and the restriction of the fine grid operators is performed recursively and matrix-free.Both h-and k-dependency are investigated tackling two-and three-dimensional problems on standard meshes and graded meshes.For the two HHO for-mulations,featuring discontinuous or hybrid pressure,we study how the combination of p-coarsening and static condensation influences the V-cycle iteration.In particular,two dif-ferent static condensation procedures are considered for the discontinuous pressure HHO variant,resulting in global linear systems with a different number of unknowns and matrix non-zero entries.Interestingly,we show that the efficiency of the solution strategy might be impacted by static condensation options in the case of graded meshes.展开更多
Different polymorphs of Mg-Sn and Mg-Pb intermetallic compounds were prepared by high-energy mechanical alloying and then investigated as active material in magnesium batteries. Beside thermodynamically stable Mg_(2)S...Different polymorphs of Mg-Sn and Mg-Pb intermetallic compounds were prepared by high-energy mechanical alloying and then investigated as active material in magnesium batteries. Beside thermodynamically stable Mg_(2)Sn and Mg_(2)Pb crystallizing in the anti-fluorite structure, other polymorphs Mg_(~2)Sn and Mg_(~2)Pb were prepared by increasing the ball-milling time. The first dealloying process is almost complete only for the cubic polymorphs, then similar capacities are observed during the subsequent alloying and dealloying sequences.Thanks to operando X-ray diffraction, the electrochemical mechanism is revealed and shows that the cubic polymorphs Mg_(2)Sn and Mg_(2)Pb tend to preferentially form during the alloying whatever the pristine intermetallic. Weak traces of Mg_(~2)Sn and Mg_(~2)Pb are observed during the alloying, suggesting that these polymorphs act as a by-product and/or an intermediate phases of the electrochemical process. Finally, the compatibility of cubic Mg_(2)Sn and Mg_(2)Pb with Mg(TFSI)_(2)-based electrolyte is confirmed in full cell vs. a positive electrode based on the Chevrel phase Mo6S8, although limited performance is achieved. This fundamental work provides new insights in the behavior of alloy-type negative electrodes for magnesium-ion batteries.展开更多
This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such serv...This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such services in order to be able to prioritize them with respect to social well-being. This identification phase is seldom discussed. It requires that survey questionnaires be designed so as to improve understanding of these perceptions. The surveys undertaken combined both open questions where the interviewees expressed their perceptions spontaneously and closed questions where they were invited to rank a pre-established list of the relevant services. These surveys involved 133 fish farmers and 93 stakeholders. The results show that perceptions differ by question type, and confirm the significance of the questionnaire design and the importance of combining several kinds of approach.展开更多
Background:Individual tree extraction from terrestrial laser scanning(TLS)data is a prerequisite for tree-scale estimations of forest biophysical properties.This task currently is undertaken through laborious and time...Background:Individual tree extraction from terrestrial laser scanning(TLS)data is a prerequisite for tree-scale estimations of forest biophysical properties.This task currently is undertaken through laborious and time-consuming manual assistance and quality control.This study presents a new fully automatic approach to extract single trees from large-area TLS data.This data-driven method operates exclusively on a point cloud graph by path finding,which makes our method computationally efficient and universally applicable to data from various forest types.Results:We demonstrated the proposed method on two openly available datasets.First,we achieved state-of-the-art performance on locating single trees on a benchmark dataset by significantly improving the mean accuracy by over 10% especially for difficult forest plots.Second,we successfully extracted 270 trees from one hectare temperate forest.Quantitative validation resulted in a mean Intersection over Union(mIoU)of 0.82 for single crown segmentation,which further led to a relative root mean square error(RMSE%)of 21.2% and 23.5% for crown area and tree volume estimations,respectively.Conclusions:Our method allows automated access to individual tree level information from TLS point clouds.The proposed method is free from restricted assumptions of forest types.It is also computationally efficient with an average processing time of several seconds for one million points.It is expected and hoped that our method would contribute to TLS-enabled wide-area forest qualifications,ranging from stand volume and carbon stocks modelling to derivation of tree functional traits as part of the global ecosystem understanding.展开更多
The incorporation of Pt into an iron-nitrogen-carbon(Fe NC)catalyst for the oxygen reduction reaction(ORR)was recently shown to enhance catalyst stability without Pt directly contributing to the ORR activity.However,t...The incorporation of Pt into an iron-nitrogen-carbon(Fe NC)catalyst for the oxygen reduction reaction(ORR)was recently shown to enhance catalyst stability without Pt directly contributing to the ORR activity.However,the mechanistic origin of this stabilisation remained obscure.It is established herein with rotating ring disc experiments that the side product,H_(2)O_(2),which is known to damage FeNC catalysts,is suppressed by the presence of Pt.The formation of reactive oxygen species is additionally inhibited,independent of intrinsic H_(2)O_(2) formation,as determined by electron paramagnetic resonance.Transmission electron microscopy identifies an oxidised Fe-rich layer covering the Pt particles,thus explaining the inactivity of the latter towards the ORR.These insights develop understanding of Fe NC degradation mechanisms during ORR catalysis,and crucially establish the required properties of a precious metal free protective catalyst to improve Fe NC stability in acidic media.展开更多
The Action Group called‘Standardized methods across Permafrost Landscapes:from Arctic Soils to Hydrosystems’(SPLASH)is a community-driven effort aiming to provide a suite of standardized field strategies for samplin...The Action Group called‘Standardized methods across Permafrost Landscapes:from Arctic Soils to Hydrosystems’(SPLASH)is a community-driven effort aiming to provide a suite of standardized field strategies for sampling mineral and organic components in soils,sediments,and water across permafrost landscapes.This unified approach will allow data from different landscape interfaces,field locations and seasons to be shared and compared,thus improving our understanding of the processes occurring during lateral transport in circumpolar Arctic watersheds.展开更多
基金supported as part of the Center for Hierarchical Waste Form Materials,an Energy Frontier Research Center funded by the U.S.Department of Energy,Office of Science,Basic Energy Sciences under Award No.DE-SC0016574.
文摘Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications.
基金supported by a grant from the Association Française contre les Myopathies(AFM Téléthongrant 23667,to JCL).
文摘Amyotrophic lateral sclerosis is a very disabling disease due to the degeneration of motor neurons.Symptoms include muscle weakness and atrophy,spasticity,and progressive paralysis.Currently,there is no treatment to reverse damage to motor neurons and cure amyotrophic lateral sclerosis.The only two treatments actually approved,riluzole and edaravone,have shown mitigated beneficial effects.The difficulty to find a cure lies in the complexity and multifaceted pattern of amyotrophic lateral sclerosis pathogenesis.Among mechanisms,abnormal RNA metabolism,nucleocytoplasmic transport defects,accumulation of unfolded protein,and mitochondrial dysfunction would in fine induce oxidative damage and vice versa.A potent therapeutic strategy will be to find molecules that break this vicious circle.Sharpening the nuclear factor erythroid-2 related factor 2 signaling may fulfill this objective since nuclear factor erythroid-2 related factor 2 has a multitarget profile controlling antioxidant defense,mitochondrial functioning,and inflammation.We here discuss the interest of developing nuclear factor erythroid-2 related factor 2-based therapy in regard to the pathophysiological mechanisms and we provide a general overview of the attempted clinical assays in amyotrophic lateral sclerosis.
文摘This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.
基金supported by the GENES intra-Africa Academic Mobility scheme of the European Union(EU-GENES:EACEA/2917/2552)the DESIRA-ABEE project funded by European Union。
文摘Peanut is a worldwide oilseed crop and the need to assess germplasm in a non-destructive manner is important for seed nutritional breeding.In this study,Near Infrared Spectroscopy(NIRS)was applied to rapidly assess germplasm variability from whole seed of 699 samples,field-collected and assembled in four genetic and environmentbased sets:one set of 300 varieties of a core-collection and three sets of 133 genotypes of an interspecific population,evaluated in three environments in a large spatial scale of two countries,Mbalmayo and Bafia in Cameroon and Nioro in Senegal,under rainfed conditions.NIR elemental spectra were gathered on six subsets of seeds of each sample,after three rotation scans,with a spectral resolution of 16 cm-1over the spectral range of867 nm to 2530 nm.Spectra were then processed by principal component analysis(PCA)coupled with Partial least squares-discriminant analysis(PLS-DA).As results,a huge variability was found between varieties and genotypes for all NIR wavelength within and between environments.The magnitude of genetic variation was particularly observed at 11 relevant wavelengths such as 1723 nm,usually related to oil content and fatty acid composition.PCA yielded the most chemical attributes in three significant PCs(i.e.,eigenvalues>10),which together captured 93%of the total variation,revealing genetic and environment structure of varieties and genotypes into four clusters,corresponding to the four samples sets.The pattern of genetic variability of the interspecific population covers,remarkably half of spectrum of the core-collection,turning out to be the largest.Interestingly,a PLS-DA model was developed and a strong accuracy of 99.6%was achieved for the four sets,aiming to classify each seed sample according to environment origin.The confusion matrix achieved for the two sets of Bafia and Nioro showed 100%of instances classified correctly with 100%at both sensitivity and specificity,confirming that their seed quality was different from each other and all other samples.Overall,NIRS chemometrics is useful to assess and distinguish seeds from different environments and highlights the value of the interspecific population and core-collection,as a source of nutritional diversity,to support the breeding efforts.
基金This study was supported by the National Natural Science Foundation of China(42271396)the Natural Science Foundation of Shandong Province(ZR2022MD017)+1 种基金the Key R&D Project of Hebei Province(22326406D)The European Space Agency(ESA)and Ministry of Science and Technology of China(MOST)Dragon(57457).
文摘Cereal is an essential source of calories and protein for the global population.Accurately predicting cereal quality before harvest is highly desirable in order to optimise management for farmers,grading harvest and categorised storage for enterprises,future trading prices,and policy planning.The use of remote sensing data with extensive spatial coverage demonstrates some potential in predicting crop quality traits.Many studies have also proposed models and methods for predicting such traits based on multiplatform remote sensing data.In this paper,the key quality traits that are of interest to producers and consumers are introduced.The literature related to grain quality prediction was analyzed in detail,and a review was conducted on remote sensing platforms,commonly used methods,potential gaps,and future trends in crop quality prediction.This review recommends new research directions that go beyond the traditional methods and discusses grain quality retrieval and the associated challenges from the perspective of remote sensing data.
基金financially supported by the AfricaYam Project(Grant OPP1052998-Bill and Melinda Gates Foundation).
文摘Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.
基金funded by the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2021-OCRI)China Agriculture Research System(CARS14)+2 种基金Hubei International Science and Technology Cooperation Project(2022EHB034)the Science and Technology Innovation Project of Hubei Province(2021-620-000-001-035)the Fundamental Research Funds for Central Non-profit Scientific Institution(2013).
文摘Sesame(Sesamum indicum L.) plays a crucial role in Ethiopian agriculture,serving both subsistence and commercial purposes.However,our understanding of the extensive genetic diversity and population structure of Ethiopian sesame remains limited.To address this knowledge gap,we genotyped 368 Ethiopian sesame germplasms,categorizing into four distinct breeding groups:Accessions,landraces,improved varieties,and wild types,using a comprehensive set of 28 polymorphic markers,including 23 simple sequence repeat(SSR) and five Insertion-Deletion(InDel) markers.These markers ensured robust genomic representation,with at least two markers per linkage group.Our results unveiled substantial genetic diversity,identifying a total of 535 alleles across all accessions.On average,each locus displayed 8.83 alleles,with observed and expected heterozygosity values of 0.30 and 0.36,respectively.Gene Diversity and Polymorphic Information Content(PIC) were recorded at 0.37 and 0.35.The percentage of polymorphic loci varied significantly among breeding groups,ranging from8.00% to 82.40%,indicating high diversity in accessions(82.4%),moderate diversity in improved varieties(31.20%) and landraces(29.60%),and limited diversity in wild types(8.00).Analysis of Molecular Variance(AMOVA) results emphasized significant genetic differentiation among populations,with substantial diversity(P<0.001) within each population.Approximately 8% of the entire genetic diversity could be attributed to distinctions among populations,while the larger proportion of genetic diversity(92%) resided within each individual sesame population,showcasing heightened diversity within each group.Our study’s findings received support from both Bayesian clustering and Neighbor-joining(NJ) analysis,reaffirming the credibility of our genetic structure insights.Notably,Population structure analysis at its highest Δk value(k=2) revealed the existence of two primary genetic clusters,further subdivided into four sub-populations at k=4.Similarly,NJ analysis identified two prominent clusters,each displaying additional sub-clustering.In conclusion,our research provides a comprehensive understanding of genetic groups,subpopulations,and overall diversity within Ethiopian sesame populations.These findings underscore the significant genetic diversity and population structure within Ethiopian sesame germplasm collections.This genetic richness holds promise for breeding and conservation efforts,highlighting the importance of preserving genetic diversity to ensure adaptation to changing environments and meet the needs of farmers and consumers.
基金the National Swedish Research Council(grants No.2015-04402,2019-04486)the Carl Trygger Foundation(CTS 20:6)+3 种基金the Jornvall FoundationJulian Francis for financial supportthe National Genomics Infrastructure in Stockholm funded by Science for Life Laboratory,the Knut and Alice Wallenberg Foundationthe Research/Scientific Computing teams at The James Hutton Institute and NIAB for providing computational resources and technical support for the"UK's Crop Diversity Bioinformatics HPC"(BBSRC grant BB/S019669/1)。
文摘The family Alaudidae,larks,comprises 93-100 species(depending on taxonomy)that are widely distributed across Africa and Eurasia,with single species extending their ranges to North and northernmost South America and Australia.A decade-old molecular phylogeny,comprising~80%of the species,revealed multiple cases of parallel evolution and large variation in rates of morphological evolution,which had misled taxonomists into creating many non-monophyletic genera.Here,we reconstruct the phylogeny of the larks,using a dataset covering one mitochondrial and 16 nuclear loci and comprising all except one of the currently recognised species as well as several recently proposed new species(in total 133 taxa;not all loci available for all species).We provide additional support using genome-wide markers to infer a genus-level phylogeny based on near-complete generic sampling(in total 51 samples of 44 taxa across 40 species).Our results confirm the previous findings of rampant morphological convergence and divergence,and reveal new cases of paraphyletic genera.We propose a new subfamily classification,and also that the genus Mirafra is divided into four genera to produce a more balanced generic classification of the Alaudidae.Our study supports recently proposed species splits as well as some recent lumps,while also questioning some of the latter.This comprehensive phylogeny will form an important basis for future studies,such as comparative studies of lark natural history,ecology,evolution and conservation.
文摘Agroecosystems in the Senegalese groundnut basin experience long periods of high temperatures and drought, which disrupt the stability of soil microbial communities. This study evaluated how that stability is affected by homefields and outfields’ agricultural practices and the duration of heat stress. Specifically, we collected soils from organically farmed fields that receive continual high inputs of manure (homefields), and from fields that are rarely manured (outfields). Soil samples were submitted to artificial heat stress at 60°C for 3, 14, and 28 days, followed by 28 days of recovery at 28°C. We examined the functional stability of microbial communities by quantifying C mineralization, and characterized the stability of the communities’ taxonomic compositions via high-throughput DNA sequencing. We found that the microbial communities have a low resistance to heat stress in soils from both types of fields. However, the manuring practice does affect how the functional stability of microbial communities responds to different durations of heat stress. Although functional stability was not recovered fully in either soil, microbial community resilience seemed to be greater in homefield soils. Differences in manuring practices also affected the structural taxonomic stability of microbial communities: relative abundances of Bacilli, Chloroflexia, Actinobacteria and Sordariomycetes increased in the homefield stressed-soils, but decreased significantly in outfield soils. In contrast, relative abundances of α-Proteobacteria, γ-Proteobacteria and Eurotiomycetes increased significantly in outfield stressed-soils, while decreasing significantly in the homefield soils. Relative abundances of Bacilli changed little in outfield soils, indicating that this taxon is resistant to heat stress. In summary, the microbial communities’ capacities to resist heat stress and recover from it depend upon the organic richness of the soil (i.e., manuring practice) and the adaptation of soil microbes to environmental conditions.
基金funded by the ApCoreStress project(INRA-BAP department)and supported by GIS Fruit(Bilan Yonis-Omar’s internship).
文摘Despite previous reports on the genotypic variation of architectural and functional traits in fruit trees,phenotyping large populations in the field remains challenging.In this study,we used high-throughput phenotyping methods on an apple tree core-collection(1000 individuals)grown under contrasted watering regimes.First,architectural phenotyping was achieved using T-LiDAR scans for estimating convex and alpha hull volumes and the silhouette to total leaf area ratio(STAR).Second,a semi-empirical index(IPL)was computed from chlorophyll fluorescence measurements,as a proxy for leaf photosynthesis.Last,thermal infrared and multispectral airborne imaging was used for computing canopy temperature variations,water deficit,and vegetation indices.All traits estimated by these methods were compared to low-throughput in planta measurements.Vegetation indices and alpha hull volumes were significantly correlated with tree leaf area and trunk cross sectional area,while IPL values showed strong correlations with photosynthesis measurements collected on an independent leaf dataset.By contrast,correlations between stomatal conductance and canopy temperature estimated from airborne images were lower,emphasizing discrepancies across measurement scales.High heritability values were obtained for almost all the traits except leaf photosynthesis,likely due to large intra-tree variation.Genotypic means were used in a clustering procedure that defined six classes of architectural and functional combinations.Differences between groups showed several combinations between architectural and functional traits,suggesting independent genetic controls.This study demonstrates the feasibility and relevance of combining multi-scale high-throughput methods and paves the way to explore the genetic bases of architectural and functional variations in woody crops in field conditions.
文摘There is an increasing interest in developing nanoparticles with diverse biologic activities.To this end,we prepared 10 to 15 nm silver nanoparticles(AgNP)from native isolates of Trichoderma atroviride.Within this study,endophytic fungi hosted four medicinal plants in Saint Katherine Protectorate,South Sinai,Egypt have been isolated by surface sterilization technique on four isolation media.Ten species,based on their frequency of occurrence,out of twenty recovered taxa were tested for their capability to synthesize extracellular AgNPs.Trichoderma atroviride hosted Chiliadenus montanus was found to be the best candidate for the production of mycogenic AgNPs among all examined species.The mycosynthesized AgNPs were compared with chemically synthesized and characterized using Ultraviolet-visible(UV-vis)spectroscopy,Raman spectroscopy,X-ray diffraction(XRD)and high-resolution transmission electron microscopy(HRTEM)techniques.The HRTEM result showed the distribution of spherical AgNPs ranging from 10 to 15 nm.Trichoderma atroviride isolate was subjected to sequencing for confirmation of phenotypic identification.The internal transcribed spacer(ITS)1-5.8 s-ITS2 rDNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number MH283876 in the NCBI Database.Antibacterial,anticandidal and antifungal effects of chemically and mycosynthesized AgNPs were examined at various concentrations in vitro against six pathogenic bacteria and 4 pathogenic fungi by agar well diffusion technique.Standard antibiotics;Gentamicin,Amoxicillin,Clotrimazole,and Nystatin at 5μg/disk were taken as positive controls,while 5%DMSO was used as the negative control.Our data revealed that the application of mycogenic AgNPs at a concentration of 100 ppm resulted in maximum inhibition of pathogenic bacteria and fungi.These data suggest that AgNPs from native isolates of Trichoderma atroviride(MH283876)offer a source of rapid synthesis of eco-friendly,economical biomaterials that show antimicrobial activities.
文摘Mango anthracnose disease forms typical irregular-shaped black necrotic spots on the fruit peel of mature fruit and is caused by <i>Colletotrichum gloeosporioides</i>. In order to improve the disease control with a limited use of fungicides, new microbial agents able to limit the growth of the pathogen were searched in the indigenous natural flora of mango surface. In order to find a suitable biocontrol agent, a screening was applied to 305 epiphytic bacteria isolated from the carposphere of 17 mango cultivars sampled from eight locations on Reunion Island. The screening approach involved a first step based on the ability of the isolates to form a biofilm, to grow under fruit storage conditions, and to interfere with the development of <i>C. gloeosporioides</i>. In a second step, the capability of selected isolates to limit <i>C. gloeosporioides in vitro</i> mycelial growth and conidia germination was assessed and species identified. The most effective bacteria belonged to the <i>Enterobacter</i>, <i>Pantoea</i>, <i>Kosakonia</i> and <i>Leuconostoc</i> genera, but for some of them, their safe use has to be demonstrated. Efficacy <i>in vivo</i>, performed on wounded mature mango fruit, was limited, probably because of the wounding inoculation strategy favoring the pathogen. Future biocontrol treatments should focus on preharvest applications to enhance the protective benefit.
文摘Initially,the Sigma-1 receptor(S1R)was incorrectly categorized as one of the opioid receptors.But it has since become clear that S1R is a non-opioid non-phencyclidine receptor with molecular chaperone activity.S1R is a 223 amino-acid long protein that shares no clear homology with any other known mammalian proteins,its closest homolog being the fungal ERG2 sterol isomerase.Even its pharmacological counterpart,the Sigma-2 receptor that was only recently cloned,is genetically distinct.S1R is more likely considered as an atypical ligand-modulated chaperone protein.S1R is widely expressed in many organs including brain where its function has mainly been explored.
文摘Our common home,planet Earth,is inhabited by more than 7 billion human beings.The average life expectancy currently estimated for men is^69 years,with strong differences among countries.Currently,neurodegenerative diseases are currently the leading cause of death and disability worldwide.In clinical use and neuroscience research,a solution for an effective diagnosis is in progress,but a prophylactic treatment to counteract this long-lasting plague for humanity is still unidentified.
基金Daniele Di Pietro acknowledges the support of Agence Nationale de la Recherche Grant fast4hho(ANR-17-CE23-0019).
文摘We propose a p-multilevel preconditioner for hybrid high-order(HHO)discretizations of the Stokes equation,numerically assess its performance on two variants of the method,and compare with a classical discontinuous Galerkin scheme.An efficient implementa-tion is proposed where coarse level operators are inherited using L2-orthogonal projec-tions defined over mesh faces and the restriction of the fine grid operators is performed recursively and matrix-free.Both h-and k-dependency are investigated tackling two-and three-dimensional problems on standard meshes and graded meshes.For the two HHO for-mulations,featuring discontinuous or hybrid pressure,we study how the combination of p-coarsening and static condensation influences the V-cycle iteration.In particular,two dif-ferent static condensation procedures are considered for the discontinuous pressure HHO variant,resulting in global linear systems with a different number of unknowns and matrix non-zero entries.Interestingly,we show that the efficiency of the solution strategy might be impacted by static condensation options in the case of graded meshes.
基金financial support from the French National Research Agency (project MISTRALE, ANR-19-CE05–0013, and Labex STORE-EX, ANR10-LABX-76-01)。
文摘Different polymorphs of Mg-Sn and Mg-Pb intermetallic compounds were prepared by high-energy mechanical alloying and then investigated as active material in magnesium batteries. Beside thermodynamically stable Mg_(2)Sn and Mg_(2)Pb crystallizing in the anti-fluorite structure, other polymorphs Mg_(~2)Sn and Mg_(~2)Pb were prepared by increasing the ball-milling time. The first dealloying process is almost complete only for the cubic polymorphs, then similar capacities are observed during the subsequent alloying and dealloying sequences.Thanks to operando X-ray diffraction, the electrochemical mechanism is revealed and shows that the cubic polymorphs Mg_(2)Sn and Mg_(2)Pb tend to preferentially form during the alloying whatever the pristine intermetallic. Weak traces of Mg_(~2)Sn and Mg_(~2)Pb are observed during the alloying, suggesting that these polymorphs act as a by-product and/or an intermediate phases of the electrochemical process. Finally, the compatibility of cubic Mg_(2)Sn and Mg_(2)Pb with Mg(TFSI)_(2)-based electrolyte is confirmed in full cell vs. a positive electrode based on the Chevrel phase Mo6S8, although limited performance is achieved. This fundamental work provides new insights in the behavior of alloy-type negative electrodes for magnesium-ion batteries.
文摘This article discusses the perception of ecosystem services for French and Brazilian pond fish farming. Its aim is to study the extent to which the industry and its stakeholders are aware of the existence of such services in order to be able to prioritize them with respect to social well-being. This identification phase is seldom discussed. It requires that survey questionnaires be designed so as to improve understanding of these perceptions. The surveys undertaken combined both open questions where the interviewees expressed their perceptions spontaneously and closed questions where they were invited to rank a pre-established list of the relevant services. These surveys involved 133 fish farmers and 93 stakeholders. The results show that perceptions differ by question type, and confirm the significance of the questionnaire design and the importance of combining several kinds of approach.
基金partially funded by the Scientific Research Foundation of Xidian Universitypart of 3DForMod project(ANR-17-EGAS-0002-01)funded in the frame of the JPI FACCE ERA-GAS call funded under European Union’s Horizon 2020 research and innovation program(grant agreement No.696356).
文摘Background:Individual tree extraction from terrestrial laser scanning(TLS)data is a prerequisite for tree-scale estimations of forest biophysical properties.This task currently is undertaken through laborious and time-consuming manual assistance and quality control.This study presents a new fully automatic approach to extract single trees from large-area TLS data.This data-driven method operates exclusively on a point cloud graph by path finding,which makes our method computationally efficient and universally applicable to data from various forest types.Results:We demonstrated the proposed method on two openly available datasets.First,we achieved state-of-the-art performance on locating single trees on a benchmark dataset by significantly improving the mean accuracy by over 10% especially for difficult forest plots.Second,we successfully extracted 270 trees from one hectare temperate forest.Quantitative validation resulted in a mean Intersection over Union(mIoU)of 0.82 for single crown segmentation,which further led to a relative root mean square error(RMSE%)of 21.2% and 23.5% for crown area and tree volume estimations,respectively.Conclusions:Our method allows automated access to individual tree level information from TLS point clouds.The proposed method is free from restricted assumptions of forest types.It is also computationally efficient with an average processing time of several seconds for one million points.It is expected and hoped that our method would contribute to TLS-enabled wide-area forest qualifications,ranging from stand volume and carbon stocks modelling to derivation of tree functional traits as part of the global ecosystem understanding.
基金a fellowship from the Alexander von Humboldt foundation。
文摘The incorporation of Pt into an iron-nitrogen-carbon(Fe NC)catalyst for the oxygen reduction reaction(ORR)was recently shown to enhance catalyst stability without Pt directly contributing to the ORR activity.However,the mechanistic origin of this stabilisation remained obscure.It is established herein with rotating ring disc experiments that the side product,H_(2)O_(2),which is known to damage FeNC catalysts,is suppressed by the presence of Pt.The formation of reactive oxygen species is additionally inhibited,independent of intrinsic H_(2)O_(2) formation,as determined by electron paramagnetic resonance.Transmission electron microscopy identifies an oxidised Fe-rich layer covering the Pt particles,thus explaining the inactivity of the latter towards the ORR.These insights develop understanding of Fe NC degradation mechanisms during ORR catalysis,and crucially establish the required properties of a precious metal free protective catalyst to improve Fe NC stability in acidic media.
文摘The Action Group called‘Standardized methods across Permafrost Landscapes:from Arctic Soils to Hydrosystems’(SPLASH)is a community-driven effort aiming to provide a suite of standardized field strategies for sampling mineral and organic components in soils,sediments,and water across permafrost landscapes.This unified approach will allow data from different landscape interfaces,field locations and seasons to be shared and compared,thus improving our understanding of the processes occurring during lateral transport in circumpolar Arctic watersheds.