6,348 research outputs found

    Detecting and predicting spatial and interannual patterns of temperate forest springtime phenology in the eastern U.S.

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    We performed a diagnostic analysis of AVHRR-NDVI and gridded, temperature data for the deciduous forests of the eastern U.S., calibrating temperature accumulation model with satellite data for 1982–1993. The model predicts interannual variability in onset date based upon year-to-year changes in springtime temperature. RMS error over the period ranges from 6.9 days in the northern portion of the domain to 10.7 days in the south. The analysis revealed a relationship between temperature accumulation and satellite derived onset date (rank correlation = 0.31–0.62). The required temperature accumulation threshold can be expressed as a function of mean temperature (R2 of 0.90) to facilitate predictive analysis of phenological onset, or when remote sensing data are unavailable

    Strategic Niche Management (SNM) beyond sustainability. An exploration of key findings of SNM through the lens of ICT and privacy

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    Recently the governance of socio-technical transitions to sustainability is gaining attention in the field of innovation studies. One particular approach is that of Strategic Niche Management (SNM), which advocates the creation of protected space to experiment with radically new sustainable socio-technical practices. This paper contributes by asking whether this approach is also useful for analysis and governance of other types of socially desirable change. This question is addressed through a review of six key-findings of Strategic Niche Management and an original case study in the field of Near Field Communication (NFC) technologies for mobile payment. The social value at stake in this case is not sustainability but privacy. We draw three main conclusions. First, we find that the key-findings and concepts in SNM for sustainability are helpful to understand and interpret much of the data collected for the NFC case and privacy. However, there are notable differences in each of the key-findings, i.e findings related to a) the local-global distinction in SNM, b) expectations, c) social networks, d) learning, e) protection, and f) niche-regime interactions. Second, in relation to governance, the role of sustainability values (being a promising value to pursue) and privacy values (being a bottom-line value to defend) are notably different. Third, these differences result in different roles of public bodies in niche development. The paper ends with discussing the consequences for SNM for sustainability research and future research topics.Strategic Niche Management, sustainability, NFC, mobile payment, privacy

    Research, action and 'critical' geographies

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    In the 199Os, the notion of ‘doing’ critical geographies has become one of the central themes infusing human geographic study. Eschewing the strictures of radical Marxist approaches (which principally focused on the forms of oppression and inequality wrought by capitalist process), critical geography has consequently sought to examine the diverse sociospatial processes that regulate and reproduce social exclusion. The lens of critical geographers has thus widened from a narrow focus on capital-labour relations to encompass broader processes of social disadvantage and marginalization as they affect women, ethnic minorities, sexual dissidents, disabled people and so on. Simultaneously, this ’critical agenda’ has been accompanied by a heightened concern that the geographer’s research on social oppression and exclusion should be sensitive to the life experiences of marginalized groups. For example, in recent years there have been several papers (eg Keith 7992; Robinson 1994; Rose 1997) and collections (Canadian Geographer 1993; Professional Geographer 1994; Antipode 1995) that have examined issues such as reflexivity, empowerment, emancipation, critical praxis, positionality and power relations. Such writing has generally concentrated on the complex social relations the exist between researcher and researched, with ideas from feminist scholarship (in particular) invoked to dismiss assumptions that research is an objective and ‘value-free’ endeavour

    Near-surface remote sensing of spatial and temporal variation in canopy phenology

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    There is a need to document how plant phenology is responding to global change factors, particularly warming trends. “Near-surface” remote sensing, using radiometric instruments or imaging sensors, has great potential to improve phenological monitoring because automated observations can be made at high temporal frequency. Here we build on previous work and show how inexpensive, networked digital cameras (“webcams”) can be used to document spatial and temporal variation in the spring and autumn phenology of forest canopies. We use two years of imagery from a deciduous, northern hardwood site, and one year of imagery from a coniferous, boreal transition site. A quantitative signal is obtained by splitting images into separate red, green, and blue color channels and calculating the relative brightness of each channel for “regions of interest” within each image. We put the observed phenological signal in context by relating it to seasonal patterns of gross primary productivity, inferred from eddy covariance measurements of surface–atmosphere CO2 exchange. We show that spring increases, and autumn decreases, in canopy greenness can be detected in both deciduous and coniferous stands. In deciduous stands, an autumn red peak is also observed. The timing and rate of spring development and autumn senescence varies across the canopy, with greater variability in autumn than spring. Interannual variation in phenology can be detected both visually and quantitatively; delayed spring onset in 2007 compared to 2006 is related to a prolonged cold spell from day 85 to day 110. This work lays the foundation for regional- to continental-scale camera-based monitoring of phenology at network observatory sites, e.g., National Ecological Observatory Network (NEON) or AmeriFlux

    Simulation of seismic events induced by CO2 injection at In Salah, Algeria

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    Date of Acceptance: 18/06/2015 Acknowledgments The authors would like to thank the operators of the In Salah JV and JIP, BP, Statoil and Sonatrach, for providing the data shown in this paper, and for giving permission to publish. Midland Valley Exploration are thanked for the use of their Move software for geomechanical restoration. JPV is a Natural Environment Research Council (NERC) Early Career Research Fellow (Grant NE/I021497/1) and ALS is funded by a NERC Partnership Research Grant (Grant NE/I010904).Peer reviewedPublisher PD

    Sub-arcsecond high sensitivity measurements of the DG~Tau jet with e-MERLIN

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    We present very high spatial resolution deep radio continuum observations at 5 GHz (6 cm) made with e-MERLIN of the young stars DG Tau A and B. Assuming it is launched very close (~=1 au) from the star, our results suggest that the DG Tau A outflow initially starts as a poorly focused wind and undergoes significant collimation further along the jet (~=50 au). We derive jet parameters for DG Tau A and find an initial jet opening angle of 86 degrees within 2 au of the source, a mass-loss rate of 1.5x10^-8 solar masses/yr for the ionised component of the jet, and the total ejection/accretion ratio to range from 0.06-0.3. These results are in line with predictions from MHD jet-launching theories.Comment: Accepted MNRAS Letter

    Topographic determinants of foot and mouth disease transmission in the UK 2001 epidemic

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    Background A key challenge for modelling infectious disease dynamics is to understand the spatial spread of infection in real landscapes. This ideally requires a parallel record of spatial epidemic spread and a detailed map of susceptible host density along with relevant transport links and geographical features. Results Here we analyse the most detailed such data to date arising from the UK 2001 foot and mouth epidemic. We show that Euclidean distance between infectious and susceptible premises is a better predictor of transmission risk than shortest and quickest routes via road, except where major geographical features intervene. Conclusion Thus, a simple spatial transmission kernel based on Euclidean distance suffices in most regions, probably reflecting the multiplicity of transmission routes during the epidemic

    Роль органічних речовин води Нафтуся у її фізіологічній активності

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    В экспериментах на крысах, а также ex vivo, используя воду Нафтуся из различных скважин и в разные периоды ее мониторинга, а также выделенные из Нафтуси ее гидрофобные и гидрофильные органические вещества, выявлено 5 различающихся между собой кластеров физиологических эффектов, обусловленных количественными и качественными различиями органической компоненты Нафтуси.In experiments on rats, and also ex vivo, using water Naftussya from various chinks and in the different periods of her monitoring, and also allocated from Naftussya her hydrophobic and hydrophyle organic substances, is revealed 5 differing among themselves clusters of physiological effects caused by quantitative and qualitative distinctions organic components Naftussya

    Boundary rules and breaking of self-organized criticality in 2D frozen percolation

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    We study frozen percolation on the (planar) triangular lattice, where connected components stop growing ("freeze") as soon as their "size" becomes at least N, for some parameter N ≥ 1. The size of a connected component can be measured in several natural ways, and we consider the two particular cases of diameter and volume (i.e. number of sites). Diameter-frozen and volume-frozen percolation have been studied in previous works ([25, 11] and [27, 26], resp.), and they display radically different behaviors. These works adopt the rule that the boundary of a frozen cluster stays vacant forever, and we investigate the influence of these "boundary conditions" in the present paper. We prove the (somewhat surprising) result that they strongly matter in the diameter case, and we discuss briefly the volume case
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