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Monitoring stratification of anode biofilms in bioelectrochemical laminar flow reactors using flow cytometry

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environmental Science and Ecotechnology 2020年第4期4卷 18-25页

作者： Yuting Guo Luis FMRosa Susann Muller Falk Harnisch Department of environmental Microbiology Helmholtz-Centre for Environmental Research e UFZPermoserstrasse 1504318LeipzigGermany

A laminar flow bioelectrochemical systems(BES)was designed and benchmarked using microbial anodes dominated with Geobacter spp.The reactor architecture was based on modeled flow fields,the resulting structure was 3D printed and used for BES manufacturing.Stratification of the substrate availability within the reactor channels led to heterogeneous biomass distribution,with the maximum biomass found mainly in the initial/middle channels.The anode performance was assessed for different hydraulic retention times while coulombic efficiencies of up to 100%(including also hydrogen recycling from the cathode)and current densities of up to 75 μA cm^(-2) at an anode surface to volume ratio of 1770 cm^(2) L^(-1) after 35 days were achieved.This low current density can be clearly attributed to the heterogeneous distributions of biomass and the stratification of the microbial community structure.Further,it was shown that time and space resolved analysis of the reactor microbiomes per channel is feasible using flow cytometry.

关键词： Microbial electrochemical technology Flow cytometry Laminar flow Microbial community Electroactive microorganisms

The relationship between controllability, optimal testing resource allocation, and incubation-latent period mismatch as revealed by COVID-19

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Infectious Disease Modelling 2023年第2期8卷 514-538页

作者： Jeffery Demers William F.Fagan Sriya Potluri Justin M.Calabrese Center for Advanced Systems Understanding(CASUS) Helmholtz-Zentrum Dresden-Rosendorf(HZDR)G€orlitzGermany Dept.of Biology University of MarylandCollege ParkMDUSA Dept.of Ecological Modelling Helmholtz Centre for Environmental Research-UFZLeipzigGermany

The severe shortfall in testing supplies during the initial COVID-19 outbreak and ensuing struggle to manage the pandemic have affirmed the critical importance of optimal supplyconstrained resource allocation strategies for controlling novel disease epidemics.To address the challenge of constrained resource optimization for managing diseases with complications like pre-and asymptomatic transmission,we develop an integro partial differential equation compartmental disease model which incorporates realistic latent,incubation,and infectious period distributions along with limited testing supplies for identifying and quarantining infected individuals.Our model overcomes the limitations of typical ordinary differential equation compartmental models by decoupling symptom status from model compartments to allow a more realistic representation of symptom onset and presymptomatic transmission.To analyze the influence of these realistic features on disease controllability,we find optimal strategies for reducing total infection sizes that allocate limited testing resources between‘clinical’testing,which targets symptomatic individuals,and‘non-clinical’testing,which targets non-symptomatic individuals.We apply our model not only to the original,delta,and omicron COVID-19 variants,but also to generically parameterized disease systems with varying mismatches between latent and incubation period distributions,which permit varying degrees of presymptomatic transmission or symptom onset before infectiousness.We find that factors that decrease controllability generally call for reduced levels of non-clinical testing in optimal strategies,while the relationship between incubation-latent mismatch,controllability,and optimal strategies is complicated.In particular,though greater degrees of presymptomatic transmission reduce disease controllability,they may increase or decrease the role of nonclinical testing in optimal strategies depending on other disease factors like transmissibility and latent period length.Importantly,our model a

关键词： Testing quarantine control Optimal resource allocation Presymptomatic transmission Latent period Incubation period Age of infection

Combining European Earth Observation products with Dynamic Global Vegetation Models for estimating Essential Biodiversity Variables

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International Journal of Digital Earth 2020年第2期13卷 262-277页

作者： Mateus Dantas de Paula Marta Gómez Giménez Aidin Niamir Martin Thurner Thomas Hickler Biodiversity and Climate research centre(BiK-F) Senckenberg Gesellschaft für NaturforschungFrankfurt am MainGermany Department of Ecological Modelling UFZ—Helmholtz Centre for Environmental Research LeipzigGermany

Global,fast and accessible monitoring of biodiversity is one of the main pillars of the efforts undertaken in order to revert it loss.The Group on Earth Observations Biodiversity Observation Network(GEO-BON)provided an expert-based definition of the biological properties that should be monitored,the Essential Biodiversity Variables(EBVs).Initiatives to provide indicators for EBVs rely on global,freely available remote sensing(RS)products in combination with empirical models and field data,and are invaluable for decision making.In this study,we provide alternatives for the expansion and improvement of the EBV indicators,by suggesting current and future data from the European Space Agencýs COPERNICUS and explore the potential of RS-integrated Dynamic Global Vegetation Models(DGVMs)for the estimation of EBVs.Our review found that mainly due to the inclusion of the Sentinel constellation,Copernicus products have similar or superior potential for EBV indicator estimation in relation to their NASA counterparts.DGVMs simulate the ecosystem level EBVs(ecosystem function and structure),and when integrated with remote sensing data have great potential to not only offer improved estimation of current states but to provide projection of ecosystem impacts.We suggest that focus on producing EBV relevant outputs should be a priority within the research community,to support biodiversity preservation efforts.

关键词： Dynamic Global Vegetation Modelling remote sensing ecosystem dynamics Copernicus Programme Essential Biodiversity Variables

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Underground Space 2021年第1期6卷 35-45页

作者： Estanislao Pujades Anna Jurado Department of Computational Hydrosystems UFZ–Helmholtz Centre for Environmental ResearchPermoserstr.1504318 LeipzigGermany Institute for Groundwater Management Technische Universitat DresdenDresdenGermany

The expected growth of urban areas requires the construction of underground infrastructures,especially for improving transportation and mobility.These new infrastructures are commonly constructed below the water table because they must be deeper than previous underground structures.In addition,many urban areas are located near surface water bodies(i.e.,seas,rivers and/or lakes)that induce a shallow water table.The"cut and cover"method combined with dewatering wells is a frequently used procedure under these conditions for the construction of underground infrastructures.The main concerns of this procedure are related to the stability of the excavation bottom,the behavior of the retaining walls and/or the impacts induced by the dewatering actions.These issues must be evaluated,and new solutions must be proposed to improve its weak points.This paper compiles the main publications focused on the construction of underground infrastructures below the water table and in urban areas by using the cut and cover method combined with pumping.This review reveals that,despite many published studies,more research is needed to address some relevant issues such as:(1)the mitigation of dewatering impacts by using artificial recharge,(2)the adaptation of methods for characterizing retaining walls to be used under heterogeneous conditions,(3)the improvement of the prediction of surface settlements produced by pumping,and(4)the consideration of non-Darcy flows in the design of dewatering systems.

关键词： Dewatering Excavation Cut and cover Retaining walls Settlements

Spatial distributions of tropical tree species in northern Vietnam under environmentally variable site conditions

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Journal of Forestry research 2014年第2期25卷 257-268页

作者： Nguyen Hong Hai Kerstin Wiegand Stephan Getzin Department of Ecosystem Modelling Faculty of Forest Sciences and Forest EcologyUniversity of Goettingen Faculty of Agricultural Techniques Hatay Community College ufz helmholtz centre for environmental research–ufz Department of Ecological Modeling

Ecological interactions of species and thus their spatial pat- terns may differ between homogeneous and heterogeneous forests. To account for this, techniques of point pattern analysis were implemented on mapped locations of tree individuals from two 1-ha tropicalforest plots in Vietnam. We analyzed the effect of environmental heterogeneity on tree distributions; spatial distribution patterns of dominant species; inter-specific associations; and conspecific associations between life stages. Our analyses showed that： environmental conditions were homo- geneous at plot 1 but heterogeneous at plot 2; in both plots, all six domi- nant species were aggregated at various scales up to 30 m, and tree spe- cies were aggregated at larger scales in the homogeneous site than in the heterogeneous site; attraction between pairs of species was remarkably higher at the homogeneous site while negative associations were more frequent in the heterogeneous site; some species, H. kurzii, T. ilicifolia （homogeneous plot） and D. sylvatica, S. wightianum （heterogeneous plot） showed a lack of early life-stage individuals near conspecific adults. Moreover, additional clustering of young individuals was independent from conspecific adults, except D. sylvatica in both sites. These findings are consistent with the Janzen-ConneU hypothesis. Overall, habitat het- erogeneity influences spatial patterns and inter-specific associations of the tree species and evidences of self-thinning are shown in most species.

关键词： environmental heterogeneity spatial point pattern analysis tropical evergreen forest northern Vietnam.

Intraspecific trait variation in three common grass species reveals fine-scale species adjustment to local environmental conditions

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Journal of Plant Ecology 2018年第6期11卷 887-898页

作者： Tina Buchmann Jens Schumacher Christiane Roscher ufz Helmholtz Centre for Environmental ResearchTheodor-Lieser-Strasse 4Halle 06120Germany Institute of Mathematics StochasticsFriedrich Schiller University JenaErnst-Abbe-Platz 2Jena 07743Germany ufz Helmholtz Centre for Environmental ResearchPhysiological DiversityPermoserstraße 15Leipzig 04318Germany German centre for Integrative Biodiversity research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5eLeipzig 04103Germany

Aims Studies along environmental gradients have shown that intraspecific trait variation(ITV)may contribute considerably to community-level trait variation.However,we lack knowledge about how the extent of ITV varies on a local scale and whether a varying extent of ITV is related to differences in local environmental site and plant commu-nity characteristics.Methods We investigated plant height,specific leaf area(SLA),leaf dry mat-ter content(LDMC)and leaf greenness of three common grass spe-cies(Arrhenatherum elatius,Dactylis glomerata,Poa pratensis)in 12 mown grasslands in a local study area around Jena(Thuringia,Germany)across three spatially hierarchical sampling levels:between sites,between subplots within site and within subplots.Important Findings Arrhenatherum elatius and D.glomerata had higher means in plant height and a lower variation in leaf traits than P.pratensis.The major proportions of variation in leaf traits of P.pratensis and D.glomerata were found within subplots,while the traits of A.elatius varied mainly between sites.Trait correlations across the hierarchical sam-pling levels were highly consistent in A.elatius,but more variable in D.glomerata and P.pratensis.environmental site and plant commu-nity characteristics mostly explained a larger proportion of variation in trait means in A.elatius than in D.glomerata and P.pratensis,while metrics of ITV were generally less predictable.Our results suggest that trait variation in P.pratensis and D.glomerata is more strongly related to within-site conditions(i.***.biotic interactions),while differences in local environmental conditions between sites have a strong impact on trait variation in A.elatius.Since our study was limited to three grass species,further studies with a greater number of species are required to make generalizations about the importance of biotic interactions and environmental conditions as drivers of ITV at local scale.

关键词： grass species intraspecific trait variation leaf traits

Advances in geothermal exploration and production:Introduction

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能源地球科学(英文)

能源地球科学(英文) 2023年第4期4卷 9-10页

作者： Zhiliang He Shu Jiang Haibing Shao Bo Feng SINOPEC China School of Earth Resources China University of GeosciencesChina Helmholtz Centre for Environmental Research-UFZ Germany Jilin University China

Geothermal resources are a renewable and clean energy source that is not affected by weather,day and night,or seasonal changes.If large-scale development and utilization can be achieved(Gerald,2021),it will have important strategic and practical significance for ensuring energy supply in human society and achieving the“dual carbon goals”(Ma,2023).

关键词： weather goals strategic

Experimental investigation of different brines imbibition influences on co-and counter-current oil flows in carbonate reservoirs

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Chinese Journal of Chemical Engineering 2021年第5期34卷 17-29页

作者： Pouyan Ahmadi Mohammad Reza Aghajanzadeh Masoud Riazi Mohammad Reza Malayeri Mohammad Sharifi Enhanced Oil Recovery(EOR)research centre IOR/EOR Research InstituteShiraz UniversityShirazIran Helmholtz Centre for Environmental Research-UFZ LeipzigGermany Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Institut für Verfahrenstechnik und Umwelttechnik Technische Universität DresdenGermany

Imbibition of water,as wetting phase in oil-wet fractured carbonate reservoirs,plays a key role in fluid flow between matrix and fracture system.The type of injected seawater and its chemistry would profoundly influence the imbibition process.In this study,the impact of smart water(a brine that its ions have been adjusted to facilitate oil recovery)and low salinity water on co-and counter-current imbibition processes for oil-wet carbonate cores has been experimentally investigated.The results show an increase of about 10% in oil recovery for co-and counter-currents for smart seawater imbibition compared to that of low salinity seawater.In addition,as a result of the influence of co-and counter-current on each other,by co-current removal from one core face,the countercurrent in the other face would be intensified by as much as about 75%.A close examination of different lengths(5,7 and 9 cm)of carbonate cores with the same permeability revealed that by decreasing porous medium length,the amount of counter-current producing oil would be decreased so that in the 5 cm core,counter current oil production will not happen.For similar core lengths by increasing permeability,the share of counter current flow would be decreased approximately 18% since the capillary pressure could not overcome non-wetting phase viscous forces.Considering the role of matrix length along with a modified brine(which is designed according to the matrix mixture)strengthen the relevant mechanisms to have more oil production so that the higher thickness of matrix causes the higher amount of co-current oil producing and consequently more total recovery.

关键词： Smart water Co-current Counter current Wettability alteration Oil recovery

Trait variation in response to resource availability and plant diversity modulates functional dissimilarity among species in experimental grasslands

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Journal of Plant Ecology 2017年第6期10卷 981-993页

作者： Alrun Siebenkäs Jens Schumacher Christiane Roscher ufz Helmholtz Centre for Environmental ResearchCommunity EcologyTheodor-Lieser-Straße 4Halle 06120Germany Institute of Mathematics StochasticsFriedrich Schiller University JenaErnst-Abbe-Platz 2Jena 07743Germany ufz Helmholtz Centre for Environmental ResearchPhysiological DiversityPermoserstrasse 15Leipzig 04318Germany German centre for Integrative Biodiversity research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5eLeipzig 04103Germany

Aims Functional trait differences among species are thought to be a pre-requisite for niche differentiation.Plant traits are known to vary plastically in response to environmental conditions and different plant neighbours.However,it is not clear to which extent the direc-tion and magnitude of trait variation differ among species repre-senting different growth forms or varying dominance in different environments and how this trait variation affects community-level trait dissimilarity.Methods In a field experiment,we studied shoot and leaf traits of eight peren-nial grassland species assigned to two functional groups(grasses vs.forbs)and varying in growth stature(small vs.tall)in monocultures,two-and four-species mixtures that were exposed to two levels of light(shaded vs.full light)and nutrient availability(fertilized vs.non-fertilized)to address this gap of knowledge.Important Findings Fertilization increased leaf greenness and specific leaf area(SLA)as well as tissue nitrogen concentrations.Under shading,changes in morphological and physiological light-acquisition traits as well as increased nitrogen and decreased carbon concentrations in plant tissue indicated larger efforts to acquire light and carbon limita-tion of plant growth.Similar changes in light-acquisition traits as observed under shading and decreasing shoot biomass also revealed an accelerated carbon limitation at higher species rich-ness(SR)irrespective of the external manipulation of light and nutrient supply.Overall,the direction of trait variation in response to resource availability(shade,fertilization)and SR did not differ between functional groups or growth statures.The magnitude of variation in several traits at different resource availability,however,was larger in grasses than in forbs as well as in small-statured than in tall-statured species.In general,dominant species in terms of above-ground biomass production had taller shoots with higher carbon and lower nitrogen concentrations and allocated less biomass into leaves than subordinates.

关键词： biodiversity functional groups functional traits growth stature trait dissimilarity