112 research outputs found

    Analyzing spatial patterns and dynamics of landscapes and ecosystem services – Exploring fine-scale data and indicators

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    In den vergangenen Jahrzehnten hat der Einfluss des Menschen auf Ökosysteme stark zugenommen. Tendenzen der LandnutzungsĂ€nderung, darunter die Ausdehnung von StĂ€dten und die Intensivierung der Landwirtschaft als Folge des Bevölkerungsanstiegs und damit des Nahrungsmittel- und Energiebedarfs, fĂŒhren zu Umweltproblemen wie dem Verlust von Lebensraum und biologischer Vielfalt. Die zunehmende VerfĂŒgbarkeit von Daten mit feiner rĂ€umlicher Auflösung kann die Analyse von Merkmalen und Prozessen in Landschaften mit Hilfe von rĂ€umlichen Metriken unterstĂŒtzen. Das Ziel dieser Arbeit ist es, feinskalige Daten und rĂ€umliche Metriken zu integrieren, um Indikatoren zur Messung und Bewertung von Landnutzung, Ökosystemdienstleistungen und deren rĂ€umlichen Mustern zu entwickeln und folgende Fragen zu beantworten: Wie können LandnutzungsĂ€nderungen und Ökosystemleistungen einer Landschaft beschrieben und analysiert werden? Und, wie kann die Landschaftsperspektive zu unserem VerstĂ€ndnis von Landsystemen beitragen? In zwei verschiedenen Weltregionen werden Landschaften mit Hilfe von Hexagonen als rĂ€umliche Einheiten untersucht. Diese dienen zur Analyse von rĂ€umlichen Mustern und Beziehungen zwischen verschiedenen Indikatoren (z. B. Ökosystemdienstleistungen) und die Konzeptualisierung von Prozessen auf Landschaftsebene. Obwohl sich einige PhĂ€nomene auf feinen rĂ€umlichen Skalen manifestieren, ist es fĂŒr die Operationalisierung und Überwachung dieser Prozesse notwendig, ‚herauszuzoomen‘. Der Landschaftsansatz im Zusammenhang mit Ökosystemleistungen bietet wichtige Perspektiven im Hinblick auf Umweltauswirkungen, die durch LandnutzungsĂ€nderungen verursacht werden. Dabei können Indikatoren, die die ökologische, ökonomische und soziale Dimension verknĂŒpfen, dazu beitragen, regionalspezifisches Wissen ĂŒber Landschaftsdynamiken zu erlangen und dieses Wissen an EntscheidungstrĂ€ger weiterzugeben, um gezielte Maßnahmen fĂŒr ein nachhaltiges Landmanagement zu entwickeln.Over the last decades, anthropogenic pressures on ecosystems have been increasing. Trends of land use change including urban expansion and agricultural intensification driven by population increase, and hence food and energy demand, cause environmental challenges including habitat and biodiversity loss. Analyzing major trends of land use change requires additional metrics to capture local processes on a landscape spatial scale. Increasing fine-scale data availability can support analyses of characteristics and processes of landscapes with the help of spatial metrics, e.g. distance or density measures. The aims of this thesis are to incorporate fine-scale data and spatial metrics to develop indicators to measure and assess land-use, ecosystem services (ESS) and their spatial patterns to answer the following questions: How can land use change and ecosystem services of landscapes be described and analyzed? And how can the landscape perspective contribute to our understanding of land systems? The thesis includes three case studies in two different world regions: 1) characteristics of land use within a peri-urban gradient in Dar es Salaam, Tanzania, 2) characteristics of agricultural landscapes in Brandenburg, Germany, and 3) ecosystem service relationships at different spatial units and scales. In both regions, landscapes are investigated with hexagons as spatial units for the analysis of spatial patterns and relationships among different indicators (i.e., ESS) and conceptualize processes on a landscape level. The landscape approach in context with ecosystem services offers important perspectives regarding environmental impacts caused by land use change. Thereby, metrics integrating the ecological, economic, and social dimensions can support obtaining region-specific knowledge on landscape dynamics and transferring this knowledge to decision-makers to design targeted measures towards sustainable land management

    Defining the Peri-Urban: A Multidimensional Characterization of Spatio-Temporal Land Use along an Urban−Rural Gradient in Dar es Salaam, Tanzania

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    Highly dynamic peri-urban areas, particularly in the Global South, face many challenges including a lack of infrastructure, ownership conflicts, land degradation, and sustainable food production. This study aims to assess spatial land use characteristics and processes in peri-urban areas using the case of Dar es Salaam, Tanzania. A mixed-method approach was applied, consisting of expert interviews and spatial data analysis, on a local scale along an urban–rural gradient. Expert interviews were conducted during a field study and analyzed regarding the characteristics and processes of peri-urban land development. A GIS-based analysis of land use patterns was applied using satellite imagery and Open Street Map data to identify a number of variables, such as building density and proximity to environmental features. Results show specific patterns of land use indicators, which can be decreasing (e.g., house density), increasing (e.g., tree coverage), static (e.g., house size), or randomly distributed (e.g., distance to river), along a peri-urban gradient. Key findings identify lack of service structures and access to public transport as major challenges for the population of peri-urban areas. The combination of qualitative expert interviews and metrics-based quantitative spatial pattern analysis contributes to improved understanding of the patterns and processes in peri-urban land use changes.Peer Reviewe

    Identifying Agricultural Landscape Types for Brandenburg, Germany using IACS Data

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    The increasing demand for agricultural commodities for food and energy purposes has led to intensified agricultural production. This trend may manifest in agricultural compositions and landscape configurations that can have mixed and adverse impacts on the provision of ecosystem services. We rely on the EU’s plot-based data from the Integrated Administration and Control System (IACS) to identify different types of agricultural landscapes and their spatial distribution in Brandenburg, Germany, a study region strongly characterised by intensification trends. Based on a set of landscape metrics, we are able to characterise agricultural land use and identify six types of agricultural landscapes. We rely on a two-step cluster analysis for a hexagonal grid and find that agricultural land is dominated by cropland with different degrees of fragmentation. By providing a framework using landscape metrics derived from IACS data, our approach involves clustering to identify typologies that are transferable to other regions within the EU based on existing data. This framework can offer more tailored environmental and agricultural planning based on sophisticated measures that take into account local and regional characteristics

    Agricultural Landscapes in Brandenburg, Germany: An Analysis of Characteristics and Spatial Patterns

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    The increasing demand for agricultural commodities for food and energy purposes has led to intensified agricultural land management, along with the homogenization of landscapes, adverse biodiversity effects and robustness of landscapes regarding the provision of ecosystem services. At the same time, subsidized organic agriculture and extensive grassland use supports the provision of ecosystem services. Yet little is understood about how to evaluate a landscape’s potential to contribute to protecting and enhancing biodiversity and ecosystem services. To address this gap, we use plot-level data from the Integrated Administration and Control System (IACS) for Germany’s federal state of Brandenburg, and based on a two-step cluster analysis, we identify six types of agricultural landscapes. These clusters differ in landscape structure, diversity and measures for agricultural land management intensity. Agricultural land in Brandenburg is dominated by high shares of cropland but fragmented differently. Lands under organic management and those with a high share of maize show strong spatial autocorrelation, pointing to local clusters. Identification of different types of landscapes permits locally- and region-adapted designs of environmental and agricultural policy measures improves outcome-oriented environmental policy impact evaluation and landscape planning. Our approach allows transferability to other EU regions.Deutsche ForschungsgemeinschaftHumboldt-UniversitĂ€t zu Berlin (1034)Peer Reviewe

    Importance of substrates for the visibility of "dark" plasmonic modes

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    Dark plasmonic modes have interesting properties, including longer lifetimes and narrower linewidths than their radiative counterpart, and little to no radiative losses. However, they have not been extensively studied yet due to their optical inaccessibility. In this work, we systematically investigated the dark radial breathing modes (RBMs) in monocrystalline gold nanodisks, specifically their outcoupling behavior into the far-field by cathodoluminescence spectroscopy. Increasing the substrate thickness resulted in an up to 4-fold enhanced visibility. This is attributed to breaking the mirror symmetry by the high-index substrate, creating an effective dipole moment. Furthermore, the resonance energy of the dark RMBs can be easily tuned by varying the nanodisk diameter, making them promising candidates for nanophotonic applications. © 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

    Haemofiltration in newborns treated with extracorporeal membrane oxygenation: a case-comparison study

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    Introduction: Extracorporeal membrane oxygenation is a supportive cardiopulmonary bypass technique for patients with acute reversible cardiovascular or respiratory failure. Favourable effects of haemofiltration during cardiopulmonary bypass instigated the use of this technique in infants on extracorporeal membrane oxygenation. The current study aimed at comparing clinical outcomes of newborns on extracorporeal membrane oxygenation with and without continuous haemofiltration. Methods: Demographic data of newborns treated with haemofiltration during extracorporeal membrane oxygenation were compared with those of patients treated without haemofiltration in a retrospective 1:3 case-comparison study. Primary outcome parameters were time on extracorporeal membrane oxygenation, time until extubation after decannulation, mortality and potential cost reduction. Secondary outcome parameters were total and mean fluid balance, urine output in mL/kg/day, dose of vasopressors, blood products and fluid bolus infusions, serum creatinin, urea and albumin levels. Results: Fifteen patients with haemof

    Exploring preservice, beginning and experienced teachers' noticing of classroom management situations from an actor's perspective

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    Publisher Copyright: © 2021 The AuthorsWe investigated preservice (n = 21), beginning (n = 17) and experienced (n = 19) teachers' noticing of salient classroom management situations during teaching. Teachers wore a front-view camera while teaching. A two-method approach was used to identify salient situations and verbalizations of accompanying cognitions: hand-signals while teaching and stimulated-recall interview. Mixed-method analysis showed that teacher groups noticed similar amounts and types of situations distributed across the lesson time. Preservice teachers identified more situations than beginners in interviews, whereas beginners identified more situations by hand-signaling while teaching. Findings indicate non-linear professional development of teachers' noticing and the value of a two-method approach to capture teachers’ noticing.Peer reviewe

    SARS-CoV-2 variant Alpha has a spike-dependent replication advantage over the ancestral B.1 strain in human cells with low ACE2 expression

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    Epidemiological data demonstrate that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) Alpha and Delta are more transmissible, infectious, and pathogenic than previous variants. Phenotypic properties of VOC remain understudied. Here, we provide an extensive functional study of VOC Alpha replication and cell entry phenotypes assisted by reverse genetics, mutational mapping of spike in lentiviral pseudotypes, viral and cellular gene expression studies, and infectivity stability assays in an enhanced range of cell and epithelial culture models. In almost all models, VOC Alpha spread less or equally efficiently as ancestral (B.1) SARS-CoV-2. B.1. and VOC Alpha shared similar susceptibility to serum neutralization. Despite increased relative abundance of specific sgRNAs in the context of VOC Alpha infection, immune gene expression in infected cells did not differ between VOC Alpha and B.1. However, inferior spreading and entry efficiencies of VOC Alpha corresponded to lower abundance of proteolytically cleaved spike products presumably linked to the T716I mutation. In addition, we identified a bronchial cell line, NCI-H1299, which supported 24-fold increased growth of VOC Alpha and is to our knowledge the only cell line to recapitulate the fitness advantage of VOC Alpha compared to B.1. Interestingly, also VOC Delta showed a strong (595-fold) fitness advantage over B.1 in these cells. Comparative analysis of chimeric viruses expressing VOC Alpha spike in the backbone of B.1, and vice versa, showed that the specific replication phenotype of VOC Alpha in NCI-H1299 cells is largely determined by its spike protein. Despite undetectable ACE2 protein expression in NCI-H1299 cells, CRISPR/Cas9 knock-out and antibody-mediated blocking experiments revealed that multicycle spread of B.1 and VOC Alpha required ACE2 expression. Interestingly, entry of VOC Alpha, as opposed to B.1 virions, was largely unaffected by treatment with exogenous trypsin or saliva prior to infection, suggesting enhanced resistance of VOC Alpha spike to premature proteolytic cleavage in the extracellular environment of the human respiratory tract. This property may result in delayed degradation of VOC Alpha particle infectivity in conditions typical of mucosal fluids of the upper respiratory tract that may be recapitulated in NCI-H1299 cells closer than in highly ACE2-expressing cell lines and models. Our study highlights the importance of cell model evaluation and comparison for in-depth characterization of virus variant-specific phenotypes and uncovers a fine-tuned interrelationship between VOC Alpha- and host cell-specific determinants that may underlie the increased and prolonged virus shedding detected in patients infected with VOC Alpha

    Colorectal cancer incidences in Lynch syndrome: a comparison of results from the prospective lynch syndrome database and the international mismatch repair consortium

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    Objective To compare colorectal cancer (CRC) incidences in carriers of pathogenic variants of the MMR genes in the PLSD and IMRC cohorts, of which only the former included mandatory colonoscopy surveillance for all participants. Methods CRC incidences were calculated in an intervention group comprising a cohort of confirmed carriers of pathogenic or likely pathogenic variants in mismatch repair genes (path_MMR) followed prospectively by the Prospective Lynch Syndrome Database (PLSD). All had colonoscopy surveillance, with polypectomy when polyps were identified. Comparison was made with a retrospective cohort reported by the International Mismatch Repair Consortium (IMRC). This comprised confirmed and inferred path_MMR carriers who were first- or second-degree relatives of Lynch syndrome probands. Results In the PLSD, 8,153 subjects had follow-up colonoscopy surveillance for a total of 67,604 years and 578 carriers had CRC diagnosed. Average cumulative incidences of CRC in path_MLH1 carriers at 70 years of age were 52% in males and 41% in females; for path_MSH2 50% and 39%; for path_MSH6 13% and 17% and for path_PMS2 11% and 8%. In contrast, in the IMRC cohort, corresponding cumulative incidences were 40% and 27%; 34% and 23%; 16% and 8% and 7% and 6%. Comparing just the European carriers in the two series gave similar findings. Numbers in the PLSD series did not allow comparisons of carriers from other continents separately. Cumulative incidences at 25 years were < 1% in all retrospective groups. Conclusions Prospectively observed CRC incidences (PLSD) in path_MLH1 and path_MSH2 carriers undergoing colonoscopy surveillance and polypectomy were higher than in the retrospective (IMRC) series, and were not reduced in path_MSH6 carriers. These findings were the opposite to those expected. CRC point incidence before 50 years of age was reduced in path_PMS2 carriers subjected to colonoscopy, but not significantly so

    Non-Standard Errors

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    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants
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