243 results match your criteria: "ETH Centre[Affiliation]"

Optimal Multi-Type Sensor Placement for Structural Identification by Static-Load Testing.

Sensors (Basel)

December 2017

Applied Computing and Mechanics Laboratory (IMAC), School of Architecture, Civil and Environmental Engineering (ENAC), Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland.

Assessing ageing infrastructure is a critical challenge for civil engineers due to the difficulty in the estimation and integration of uncertainties in structural models. Field measurements are increasingly used to improve knowledge of the real behavior of a structure; this activity is called structural identification. Error-domain model falsification (EDMF) is an easy-to-use model-based structural-identification methodology which robustly accommodates systematic uncertainties originating from sources such as boundary conditions, numerical modelling and model fidelity, as well as aleatory uncertainties from sources such as measurement error and material parameter-value estimations.

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Please note that the legend to Fig. 1 has been modified since this article was originally published, and also that in Tables 2, 3 and 4, R[2] was corrected to (the now correct) R squared.

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Habitat degradation can reduce or even prevent the reproduction of previously abundant plant species. To develop appropriate management strategies, we need to understand the reasons for reduced recruitment in degraded ecosystems. The dioecious coco de mer palm () produces by far the largest seeds of any plant.

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A common challenge with processing naturalistic driving data is that humans may need to categorize great volumes of recorded visual information. By means of the online platform CrowdFlower, we investigated the potential of crowdsourcing to categorize driving scene features (i.e.

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This research directly assesses older people's neural activation in response to a changing urban environment while walking, as measured by electroencephalography (EEG). The study builds on previous research that shows changes in cortical activity while moving through different urban settings. The current study extends this methodology to explore previously unstudied outcomes in older people aged 65 years or more (n = 95).

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Quantification of the evolution of firm size distributions due to mergers and acquisitions.

PLoS One

October 2017

ETH Zurich, Department of Management, Technology, and Economics, Zurich, Switzerland.

The distribution of firm sizes is known to be heavy tailed. In order to account for this stylized fact, previous economic models have focused mainly on growth through investments in a company's own operations (internal growth). Thereby, the impact of mergers and acquisitions (M&A) on the firm size (external growth) is often not taken into consideration, notwithstanding its potential large impact.

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With rapid urbanization in the coastal zone and increasing habitat losses, it is imperative to understand how urban development affects coastal biodiversity and ecosystem service provision. Furthermore, it is important to understand how habitat fragments can best be incorporated into broader land use planning and coastal management, in order to maximize the environmental benefits they provide. In this study, we characterized the trade-offs between (a) urban development and individual mangrove environmental indicators (habitat quality and ecosystem services), and (b) between different environmental indicators in the tropical nation of Singapore.

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Background: Up to one half of the population in Africa, Asia and Latin America has little access to high-quality biomedical services and relies on traditional health systems. Medical pluralism is thus in many developing countries the rule rather than the exception, which is why the World Health Organization is calling for intercultural partnerships to improve health care in these regions. They are, however, challenging due to disparate knowledge systems and lack of trust that hamper understanding and collaboration.

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Sociotechnical Resilience: A Preliminary Concept.

Risk Anal

January 2018

Division of Sociology, School of Social Sciences, Nanyang Technological University, Singapore.

This article presents the concept of sociotechnical resilience by employing an interdisciplinary perspective derived from the fields of science and technology studies, human factors, safety science, organizational studies, and systems engineering. Highlighting the hybrid nature of sociotechnical systems, we identify three main constituents that characterize sociotechnical resilience: informational relations, sociomaterial structures, and anticipatory practices. Further, we frame sociotechnical resilience as undergirded by the notion of transformability with an emphasis on intentional activities, focusing on the ability of sociotechnical systems to shift from one form to another in the aftermath of shock and disturbance.

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Quantum Decision Theory in Simple Risky Choices.

PLoS One

July 2017

ETH Zürich, Department of Management, Technology and Economics, Scheuchzerstrasse 7, 8092 Zürich, Switzerland.

Quantum decision theory (QDT) is a recently developed theory of decision making based on the mathematics of Hilbert spaces, a framework known in physics for its application to quantum mechanics. This framework formalizes the concept of uncertainty and other effects that are particularly manifest in cognitive processes, which makes it well suited for the study of decision making. QDT describes a decision maker's choice as a stochastic event occurring with a probability that is the sum of an objective utility factor and a subjective attraction factor.

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Groundwater is extensively used in Jakarta to compensate for the limited public water supply network. Recent observations show a rise in nitrate (NO3(-)) levels in the shallow aquifer, thus pointing at a potential risk for public health. The detected levels are still below national and international regulatory limits for drinking water but a strategy is necessary to contain the growing problem.

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Ethnopharmacological Relevance: This paper presents one of the first large-scale collaborative research projects in ethnopharmacology, to bring together indigenous stakeholders and scientists both in project design and execution. This approach has often been recommended but rarely put into practice. The study was carried out in two key indigenous areas of Guatemala, for which very little ethnopharmacological fieldwork has been published.

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Currency target-zone modeling: An interplay between physics and economics.

Phys Rev E Stat Nonlin Soft Matter Phys

December 2015

ETH Zurich, Department of Management, Technology, and Economics, Scheuchzerstrasse 7, 8092 Zürich, Switzerland.

We study the performance of the euro-Swiss franc exchange rate in the extraordinary period from September 6, 2011 to January 15, 2015 when the Swiss National Bank enforced a minimum exchange rate of 1.20 Swiss francs per euro. Within the general framework built on geometric Brownian motions and based on the analogy between Brownian motion in finance and physics, the first-order effect of such a steric constraint would enter a priori in the form of a repulsive entropic force associated with the paths crossing the barrier that are forbidden.

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Transdisciplinarity (TD) is a participatory research approach in which actors from science and society work closely together. It offers means for promoting knowledge integration and finding solutions to complex societal problems, and can be applied within a multiplicity of epistemic systems. We conducted a TD process from 2011 to 2014 between indigenous Mayan medical specialists from Guatemala and Western biomedical physicians and scientists to study cancer.

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Plants of different ploidy levels are separated by a strong postzygotic hybridization barrier that is established in the endosperm. Deregulated parent-of-origin specific genes cause the response to interploidy hybridizations, revealing an epigenetic basis of this phenomenon. In this study, we present evidence that paternal hypomethylation can bypass the interploidy hybridization barrier by alleviating the requirement for the Polycomb Repressive Complex 2 (PRC2) in the endosperm.

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Efficient detection of contagious outbreaks in massive metropolitan encounter networks.

Sci Rep

June 2014

National Information and Communications Technology Australia, University of Melbourne, Victoria 3010, Australia.

Physical contact remains difficult to trace in large metropolitan networks, though it is a key vehicle for the transmission of contagious outbreaks. Co-presence encounters during daily transit use provide us with a city-scale time-resolved physical contact network, consisting of 1 billion contacts among 3 million transit users. Here, we study the advantage that knowledge of such co-presence structures may provide for early detection of contagious outbreaks.

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Endosperm-specific chromatin profiling by fluorescence-activated nuclei sorting and ChIP-on-chip.

Methods Mol Biol

September 2014

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, Zurich, Switzerland.

Cell-type-specific analysis of gene expression and chromatin profiling requires the isolation of discrete cell populations from complex pools. However, until now this most critical step has been labor intensive and technical challenging. Here, we describe a rapid protocol based on fluorescence-activated cell sorting (FACS) for cell-type-specific RNA and chromatin profiling.

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An imprinted gene underlies postzygotic reproductive isolation in Arabidopsis thaliana.

Dev Cell

September 2013

Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center of Plant Biology, 750 07 Uppsala, Sweden; Department of Biology and Zürich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zürich, Switzerland.

Postzygotic reproductive isolation in response to interploidy hybridizations is a well-known phenomenon in plants that forms a major path for sympatric speciation. A main determinant for the failure of interploidy hybridizations is the endosperm, a nutritious tissue supporting embryo growth, similar to the functional role of the placenta in mammals. Although it has been suggested that deregulated imprinted genes underpin dosage sensitivity of the endosperm, the molecular basis for this phenomenon remained unknown.

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Understanding of the mechanisms driving our daily face-to-face encounters is still limited; the field lacks large-scale datasets describing both individual behaviors and their collective interactions. However, here, with the help of travel smart card data, we uncover such encounter mechanisms and structures by constructing a time-resolved in-vehicle social encounter network on public buses in a city (about 5 million residents). Using a population scale dataset, we find physical encounters display reproducible temporal patterns, indicating that repeated encounters are regular and identical.

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The CHD3 chromatin remodeler PICKLE and polycomb group proteins antagonistically regulate meristem activity in the Arabidopsis root.

Plant Cell

March 2011

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zurich, Switzerland.

The chromatin modifying Polycomb group (PcG) and trithorax group (trxG) proteins are central regulators of cell identity that maintain a tightly controlled balance between cell proliferation and cell differentiation. The opposing activities of PcG and trxG proteins ensure the correct expression of specific transcriptional programs at defined developmental stages. Here, we report that the chromatin remodeling factor PICKLE (PKL) and the PcG protein CURLY LEAF (CLF) antagonistically determine root meristem activity.

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Unreduced gamete formation in plants: mechanisms and prospects.

J Exp Bot

March 2011

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, Zurich, Switzerland.

Polyploids, organisms with more than two sets of chromosomes, are widespread in flowering plants, including many important crop species. Increases in ploidy level are believed to arise commonly through the production of gametes that have not had their ploidy level reduced during meiosis. Although there have been cytological descriptions of unreduced gamete formation in a number of plants, until recently none of the underlying genes or molecular mechanisms involved in unreduced gamete production have been described.

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Regulation of cell identity by plant Polycomb and trithorax group proteins.

Curr Opin Genet Dev

October 2010

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zurich, Switzerland.

Descendants of stem cells have to make the decision whether to differentiate or whether to maintain a proliferation-competent state. This decision is mediated by the balanced activity of Polycomb group (PcG) and trithorax group (trxG) proteins. PcG proteins keep genes in a transcriptional repressed state while trxG proteins antagonize PcG activity and maintain genes in a transcriptional active state.

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The impact of the triploid block on the origin and evolution of polyploid plants.

Trends Genet

March 2010

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zurich, Switzerland.

Polyploidization, a widespread phenomenon among plants, is considered a major speciation mechanism. Polyploid plants have a high degree of immediate post-zygotic reproductive isolation from their progenitors, as backcrossing to either parent will produce mainly nonviable progeny. This reproductive barrier is called triploid block and it is caused by malfunction of the endosperm.

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Antagonizing Polycomb group-mediated gene repression by chromatin remodelers.

Epigenetics

January 2010

Department of Biology and Zurich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, Zurich, Switzerland.

Cellular identity is maintained by epigenetic processes that prevent changes of cell-type specific transcriptional programs. Polycomb group (PcG) proteins are evolutionary conserved key players of cellular identity that repress central developmental regulators by modifying chromatin structure. PcG-mediated repression is antagonized by trithorax group (trxG) proteins that prevent inappropriate repression by PcG proteins.

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