153 research outputs found

    Decolonizing political ecology: ontology, technology and 'critical' enchantment

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    Abstract Current debates about the Anthropocene have sparked renewed interest in the relationship between ecology, technology, and coloniality. How do humans relate to one another, to the living environment, and to their material or technological artifacts; and how are these relations structured by coloniality, defined not only as a material process of appropriation and subjugation, but also as an exclusionary hierarchy of knowing and being that still pervades contemporary life? While these questions have of course received attention in decolonial theory, they have also captured the interest of scholars who self-identify with the field of political ecology. However, it can be argued that political ecology still primarily adheres to research practices and paradigms that have been developed in the West, regardless of its diversity and dynamism as a field of research. It is therefore suggested that a rapprochement between decolonial theory and political ecology can open up new perspectives on current debates that are emerging around the concept of the Anthropocene. In particular, the article takes the recent interest in the ontological implications of the Anthropocene as a point of departure to bring the decolonial notion of 'border thinking' into a conversation with the so-called 'new materialism' in political ecology. While both approaches are not necessarily opposed to values grounded in rationality, they can be seen as attempts to rethink ontological divisions such as human/nature or subject/object based on 'enchanted' ways of knowing and being-in-the-world. Yet, although enchantment has the potential to counter inherently colonial practices of appropriation, commodification and objectification, it is argued that keeping a moderately critical distance to enchanted narratives is still recommended, not because of the alleged naïveté of such narratives, but rather because enchantments may also function as and through technologies of power. Key words: Anthropocene; political ecology; decoloniality; new materialism; border thinking; ontology; enchantmen

    Exploring the Governance and Implementation of Sustainable Development Initiatives through Blockchain Technology

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    Societies at large still grapple to categorize digital space as a phenomenon. At the same time, scientists and developers are searching for innovative methods to better understand how the fundamental shifts caused by digital change will affect the future of humanity over the coming decades. Interdisciplinary governance research at the intersection of technological and environmental foresight is urgently needed to minimize the risks of technological change and explore how digitalization may support, hinder or re-shape sustainability transformations. In this article, we focus on the case of ‘blockchain’ or distributed-ledger technology (DLT) to investigate how recent digital technologies may support the implementation of sustainable development initiatives. Our investigation is centered on areas of public administration and governance which will most likely see an adoption of DLT over the next two decades, such as digital identity, social service provision, and innovative climate finance. To allow for a meaningful comparison of various use cases, we propose four guiding questions that can help researchers, decision-makers and practitioners to determine whether DLT might be an appropriate choice for the sustainability-related task at hand. Moreover, we illustrate how the initial design and subsequent implementation of DLTs may support more centralized or networked modes of governance

    Electron-electron scattering in linear transport in two-dimensional systems

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    We describe a method for numerically incorporating electron--electron scattering in quantum wells for small deviations of the distribution function from equilibrium, within the framework of the Boltzmann equation. For a given temperature TT and density nn, a symmetric matrix needs to be evaluated only once, and henceforth it can be used to describe electron--electron scattering in any Boltzmann equation linear-response calculation for that particular TT and nn. Using this method, we calculate the distribution function and mobility for electrons in a quantum-well, including full finite-temperature dynamic screening effects. We find that at some parameters which we investigated, electron--electron scattering reduces mobility by approximately 40\%.Comment: 12 pages, 2 figures (uuencoded

    Biological soil crusts on agricultural soils of mesic regions promote microbial cross-kingdom co-occurrences and nutrient retention

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    IntroductionBiological soil crusts (biocrusts) are known as biological hotspots on undisturbed, nutrient-poor bare soil surfaces and until now, are mostly observed in (semi-) arid regions but are currently poorly understood in agricultural systems. This is a crucial knowledge gap because managed sites of mesic regions can quickly cover large areas. Thus, we addressed the questions (i) if biocrusts from agricultural sites of mesic regions also increase nutrients and microbial biomass as their (semi-) arid counterparts, and (ii) how microbial community assemblage in those biocrusts is influenced by disturbances like different fertilization and tillage regimes.MethodsWe compared phototrophic biomass, nutrient concentrations as well as the abundance, diversity and co-occurrence of Archaea, Bacteria, and Fungi in biocrusts and bare soils at a site with low agricultural soil quality.Results and DiscussionBiocrusts built up significant quantities of phototrophic and microbial biomass and stored more nutrients compared to bare soils independent of the fertilizer applied and the tillage management. Surprisingly, particularly low abundant Actinobacteria were highly connected in the networks of biocrusts. In contrast, Cyanobacteria were rarely connected, which indicates reduced importance within the microbial community of the biocrusts. However, in bare soil networks, Cyanobacteria were the most connected bacterial group and, hence, might play a role in early biocrust formation due to their ability to, e.g., fix nitrogen and thus induce hotspot-like properties. The microbial community composition differed and network complexity was reduced by conventional tillage. Mineral and organic fertilizers led to networks that are more complex with a higher percentage of positive correlations favoring microbe-microbe interactions. Our study demonstrates that biocrusts represent a microbial hotspot on soil surfaces under agricultural use, which may have important implications for sustainable management of such soils in the future

    TDP-43-Mediated Neuron Loss In Vivo Requires RNA-Binding Activity

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    Alteration and/or mutations of the ribonucleoprotein TDP-43 have been firmly linked to human neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). The relative impacts of TDP-43 alteration, mutation, or inherent protein function on neural integrity, however, remain less clear—a situation confounded by conflicting reports based on transient and/or random-insertion transgenic expression. We therefore performed a stringent comparative investigation of impacts of these TDP-43 modifications on neural integrity in vivo. To achieve this, we systematically screened ALS/FTLD-associated and synthetic TDP-43 isoforms via same-site gene insertion and neural expression in Drosophila; followed by transposon-based motor neuron-specific transgenesis in a chick vertebrate system. Using this bi-systemic approach we uncovered a requirement of inherent TDP-43 RNA-binding function—but not ALS/FTLD-linked mutation, mislocalization, or truncation—for TDP-43-mediated neurotoxicity in vivo

    Search for gravitational waves from low mass compact binary coalescence in LIGO's sixth science run and Virgo's science runs 2 and 3

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    We report on a search for gravitational waves from coalescing compact binaries using LIGO and Virgo observations between July 7, 2009, and October 20, 2010. We searched for signals from binaries with total mass between 2 and 25M⊙; this includes binary neutron stars, binary black holes, and binaries consisting of a black hole and neutron star. The detectors were sensitive to systems up to 40 Mpc distant for binary neutron stars, and further for higher mass systems. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass, including the results from previous LIGO and Virgo observations. The cumulative 90% confidence rate upper limits of the binary coalescence of binary neutron star, neutron star-black hole, and binary black hole systems are 1.3×10−4, 3.1×10−5, and 6.4×10−6  Mpc−3 yr−1, respectively. These upper limits are up to a factor 1.4 lower than previously derived limits. We also report on results from a blind injection challenge. © 2012 The American Physical Societ

    Upper limits on a stochastic gravitational-wave background using LIGO and Virgo interferometers at 600-1000 Hz

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    A stochastic background of gravitational waves is expected to arise from a superposition of many incoherent sources of gravitational waves, of either cosmological or astrophysical origin. This background is a target for the current generation of ground-based detectors. In this article we present the first joint search for a stochastic background using data from the LIGO and Virgo interferometers. In a frequency band of 600–1000 Hz, we obtained a 95% upper limit on the amplitude of ΩGW(f)=Ω3(f/900  Hz)3, of Ω3<0.32, assuming a value of the Hubble parameter of h100=0.71. These new limits are a factor of seven better than the previous best in this frequency band. © 2012 The American Physical Societ

    All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

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    We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration ≲1  s over the frequency band 64–5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range ∼5×10−22  Hz−1/2 to ∼1×10−20  Hz−1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors. © 2012 The American Physical Societ

    Search for gravitational waves from compact binary coalescence in LIGO and Virgo data from S5 and VSR1

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    We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-Wave Observatory and Virgo detectors. Five months of data were collected during the Laser Interferometer Gravitational-Wave Observatory’s S5 and Virgo’s VSR1 science runs. The search focused on signals from binary mergers with a total mass between 2 and 35M⊙. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for nonspinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7×10−3  yr−1 L10−1, 2.2×10−3  yr−1 L10−1, and 4.4×10−4  yr−1 L10−1, respectively, where L10 is 1010 times the blue solar luminosity. These upper limits are compared with astrophysical expectations. © 2010 The American Physical Societ
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