116 research outputs found
Efficient sampling methodologies for lake littoral invertebrates in compliance with the European Water Framework Directive
No full textLake shores are characterised by a high natural variability, which is increasingly threatened by a multitude of anthropogenic disturbances including morphological alterations to the littoral zone. The European Water Framework Directive (EU WFD) calls for the assessment of lake ecological status by monitoring biological quality elements including benthic macroinvertebrates. To identify cost- and time-efficient sampling strategies for routine lake monitoring, we sampled littoral invertebrates in 32 lakes located in different geographical regions in Europe. We compared the efficiency of two sampling methodologies, defined as habitat-specific and pooled composite sampling protocols. Benthic samples were collected from unmodified and morphologically altered shorelines. Variability within macroinvertebrate communities did not differ significantly between sampling protocols across alteration types, lake types and geographical regions. Community composition showed no significant differences between field composite samples and artificially generated composite samples, and correlation coefficients between macroinvertebrate metrics calculated with both methods and a predefined morphological stressor index were similar. We conclude that proportional composite sampling represents a time- and cost-efficient method for routine lake monitoring as requested under the EU WFD, and may be applied across various European geographical regions
Effects of shoreline alteration and habitat heterogeneity on macroinvertebrate community composition across European lakes
No full textHuman lake shore alterations often result in a substantial decrease of littoral and riparian habitat diversity and physical complexity, but the intensity at which shore alterations affect biodiversity may differ among European geographical regions. We tested if the response of littoral macroinvertebrate communities to human shoreline alterations is consistent among geographical regions. We compared community composition and diversity of human altered with those of unmodified littoral zones from 51 lakes across seven European countries in four geographical regions based on pooled composite as well as habitat-specific macroinvertebrate samples. Taxon richness and community composition differed among shore types and different habitats in all geographic regions, with morphological alteration having an overall negative effect on macroinvertebrate taxon richness. In addition, habitat heterogeneity also had a strong effect on littoral communities, with highest taxon richness found in the structurally complex macrophyte habitats in all regions. Average proportional densities of Diptera and Oligochaeta taxa generally increased in morphologically altered shores in all geographical regions, while Bivalvia, Crustacea, Ephemeroptera, Gastropoda and Trichoptera showed comparatively lower numbers in many anthropogenically altered sites. Furthermore, taxon richness was positively correlated with habitat diversity. We were able to relate changes in littoral communities to anthropogenic shoreline alterations, and linked the effect to the loss of habitats and habitat complexity. The results of our study demonstrate that littoral macroinvertebrates respond consistently negative to the influence of morphological alterations across European geographical regions in terms of biodiversity. While macroinvertebrates have previously been identified to be useful descriptors of morphological change in single countries/regions, we can now validate that they can be used to assess the ecological status of lakes in terms of morphological alterations across European regions. Our results can be used to further improve ealready existing WFD-compliant multimetric indices, for example by including taxa groups, which show a strong reaction to shoreline alterations. This could be supported by the inclusion of a suit of indicator taxa reflecting the loss of complex habitats such as macrophytes in the lake littoral
"Sport verbindet / Mehrzweckhalle Crottendorf"
No full textEntwurfen werden soll ein Mehrzweckgebäude in Crottendorf. Ein Gebäude welches die unterschiedlichen Vereine mit ihren sportlichen Aktivitäten vereint und Platz für Kommunikation und Veranstaltungen bietet. Das Spielfeld im Gebäude soll individuell an die Voraussetzungen für den jeweiligen Sport (Fußball, Handball, Tischtennis...) angepasst werden können. Das bedeutet, Spielfeldgröße und Bodenbelag müssen flexible händelbar sein. Für Events soll ein Cateringbereich mit Küche und Sitzmöglichkeiten vorhanden sein. Die Vereine haben die Möglichkeit im Foyer ihre aktuellen Spielergebnisse usw. auszuhängen. Außerdem ist dort Platz für aktive Kommunikation geschaffen
Haus der Wissenschaften Potsdam / Fassade und Konstruktion
No full textDas Thema für die Aufgabenstellung ist die Vertiefung der Fassadenkonstruktion. Insbesondere sollen die Anschlüsse der Glasfassadenkonstruktion im Erdgeschoss sowie die Konstruktion und Befestigung der vorgehängten Lochblechfassade um den oberen Bereich des Baukörpers bearbeitet werden. Alle relevanten Konstruktionsdetails, z.B.: Wandaufbau und Fensteranschlüsse, sollen dargestellt werden. Wichtig dabei ist insbesondere die Vermeidung von Kältebrücken
An index of human alteration of lake shore morphology
No full textMorphological degradation constitutes one of the most severe threats to the ecological integrity of lakes. The development of biotic assessment methods for human lake shore alterations using littoral macroinvertebrates requires quantification of the degree of degradation by a stressor index and is complicated through simultaneous physical pressures that alter natural habitat structure. The Lake Habitat Survey (LHS) method and macroinvertebrate sampling were used to produce a pan-European dataset of morphological lake shore degradation and macroinvertebrate densities covering 51 lakes in seven countries and across four geographical regions â northern, western, southern and central Europe. Lake Habitat Survey parameters that differed significantly among three categories of morphological pressure were combined to develop the stressor index components âNumber of habitats’, âHabitat diversity’, âTotal percentage volume inhabited by macrophytes’, âSum of macrophyte types’, âSum of vegetation cover types’, âSum of coarse woody debris/roots/overhanging vegetation’, âPressure index’ (number of human disturbance sources) and âNatural/artificial dominant land cover type’. Stressor index components were tested for cross-correlations and for differences among pressure levels. The final composition of the stressor index was optimized for the four studied geographical regions in Europe. The resulting stressor index correlated more strongly with macroinvertebrate metrics than simpler site-specific LHS parameters or the HabQA index developed previously in one lake in north-western Europe. The stressor index developed provides deeper insight into the morphological pressures that affect littoral invertebrate communities. The results also support the use of LHS to quantify morphological stressors at sampling site level, which can ease developing other multimetric bioassessment methods. The stressor index offers the possibility for wide and regional specific application to assess hydromorphological pressures on lakes to assist conservation planning and management and further global efforts to develop and test biotic assessment methods for lakes.</p
Morphological alterations of lake shores in Europe: A multimetric ecological assessment approach using benthic macroinvertebrates
No full textBesides pollution, lakes are affected by human alterations of lake-shore morphology. However, ecological effects of such alterations have rarely been studied systematically. Hence, we developed tools to assess the ecological effects of anthropogenic morphological alterations on European lake-shores based on pressure-specific response patterns of littoral macroinvertebrate community composition. Littoral invertebrates were sampled from 51 lakes in seven European countries. Sampling covered a range of natural to heavily morphologically degraded sites including natural shorelines, recreational beaches, ripraps and retaining walls. Biological data were supplemented by standardized morphological data that were collected via a Lake Habitat Survey (LHS) protocol and subsequently used to develop a morphological stressor index. Two biotic multimetric indices were developed based on habitat-specific samples (Littoral Invertebrate Multimetric based on HAbitat samples, LIMHA) and composite samples (Littoral Invertebrate Multimetric based on COmposite samples, LIMCO) through correlations with the morphological stressor index. Similarity analyses showed strong spatial differences in macroinvertebrate community composition between four main geographical regions, i.e. Western, Northern, Central and Southern Europe. The morphological stressor index as well as LIMCO and LIMHA have been developed for each geographical region specifically, thereby optimizing correlations of LIMCO and LIMHA with the respective morphological stressor index. The metric composition of LIMCO and LIMHA and their correlation coefficients with the morphological stressor index are comparable to existing national and regional methods that assess morphological lakeshore degradation via macroinvertebrate communities. Hence, LIMCO and LIMHA indices constitute a new stressor-specific assessment tool that enables comparable lake morphology assessment across Europe, as it has been developed involving a uniform methodology followed by regionalized optimization. These tools fulfil the standards of the EU Water Framework Directive and thus may complement existing assessment approaches used in lake monitoring focusing solely on lake eutrophication so far. (c) 2013 Elsevier Ltd. All rights reserved
Supplementary data for the manuscript "Quantitative modelling predicts the impact of DNA methylation on RNA polymerase II traffic"
No full textPatterns of gene expression are primarily determined by proteins that locally enhance or repress transcription. While many transcription factors target a restricted number of genes, others appear to modulate transcription levels globally. An example is MeCP2, an abundant methylated-DNA binding protein that is mutated in the neurological disorder Rett Syndrome. Despite much research, the molecular mechanism by which MeCP2 regulates gene expression is not fully resolved. Here we integrate quantitative, multi-dimensional experimental analysis and mathematical modelling to show that MeCP2 is a novel type of global transcriptional regulator whose binding to DNA creates "slow sites" in gene bodies. Waves of slowed-down RNA polymerase II formed behind these sites travel backward and indirectly affect initiation, reminiscent of defect-induced shock waves in non-equilibrium physics transport models. This mechanism differs from conventional gene regulation mechanisms, which often involve direct modulation of transcription initiation. Our findings point to a genome-wide function of DNA methylation that may account for the reversibility of Rett syndrome in mice. Moreover, our combined theoretical and experimental approach provides a general method for understanding how global gene expression patterns are choreographed.Waclaw, Bartlomiej; Cholewa-Waclaw, Justyna; Shah, Ruth; Webb, Shaun; Chhatbar, Kashyap; Ramsahoye, Bernard; Pusch, Oliver; Yu, Miao; Greulich, Philip; Bird, Adrian. (2019). Supplementary data for the manuscript "Quantitative modelling predicts the impact of DNA methylation on RNA polymerase II traffic", [dataset]. University of Edinburgh. School of Physics and Astronomy. https://doi.org/10.7488/ds/2568
Needle-like instruments for steering through solid organs: A review of the scientific and patent literature
No full textHigh accuracy and precision in reaching target locations inside the human body is necessary for the success of percutaneous procedures, such as tissue sample removal (biopsy), brachytherapy, and localized drug delivery. Flexible steerable needles may allow the surgeon to reach targets deep inside solid organs while avoiding sensitive structures (e.g. blood vessels). This article provides a systematic classification of possible mechanical solutions for three-dimensional steering through solid organs. A scientific and patent literature search of steerable instrument designs was conducted using Scopus and Web of Science Derwent Innovations Index patent database, respectively. First, we distinguished between mechanisms in which deflection is induced by the pre-defined shape of the instrument versus mechanisms in which an actuator changes the deflection angle of the instrument on demand. Second, we distinguished between mechanisms deflecting in one versus two planes. The combination of deflection method and number of deflection planes led to eight logically derived mechanical solutions for three-dimensional steering, of which one was dismissed because it was considered meaningless. Next, we classified the instrument designs retrieved from the scientific and patent literature into the identified solutions. We found papers and patents describing instrument designs for six of the seven solutions. We did not find papers or patents describing instruments that steer in one-plane on-demand via an actuator and in a perpendicular plane with a pre-defined deflection angle via a bevel tip or a pre-curved configuration.Accepted Author ManuscriptMedical Instruments & Bio-Inspired Technolog
. Tarragona: Cercle d'Estudis Històrics i Socials "Guillem Oliver" del Camp de Tarragona / Publicacions de la Universitat Rovira i Virgili, 2021
No full textQuantitative modelling predicts the impact of DNA methylation on RNA polymerase II traffic
No full textPatterns of gene expression are primarily determined by proteins that locally enhance or repress transcription. While many transcription factors target a restricted number of genes, others appear to modulate transcription levels globally. An example is MeCP2, an abundant methylated-DNA binding protein that is mutated in the neurological disorder Rett Syndrome. Despite much research, the molecular mechanism by which MeCP2 regulates gene expression is not fully resolved. Here we integrate quantitative, multidimensionalexperimental analysis and mathematical modelling to indicate that MeCP2 is a novel type of global transcriptional regulator whose binding to DNA creates "slow sites" in gene bodies. We hypothesise that waves of slowed-down RNA polymerase II formed behind these sites travel backward and indirectly affect initiation, reminiscent of defect-induced shock waves in non-equilibrium physics transport models. This mechanism differs from conventional gene regulation mechanisms, which often involve direct modulation of transcription initiation. Our findings point to a genome-wide function of DNA methylation that may account for the reversibility of Rett syndrome in mice. Moreover, our combined theoretical and experimental approach provides a general method for understanding how global gene expression patterns are choreographed
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