4,561 research outputs found

    A response to “Likelihood ratio as weight of evidence: a closer look” by Lund and Iyer

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    Recently, Lund and Iyer (L&I) raised an argument regarding the use of likelihood ratios in court. In our view, their argument is based on a lack of understanding of the paradigm. L&I argue that the decision maker should not accept the expert’s likelihood ratio without further consideration. This is agreed by all parties. In normal practice, there is often considerable and proper exploration in court of the basis for any probabilistic statement. We conclude that L&I argue against a practice that does not exist and which no one advocates. Further we conclude that the most informative summary of evidential weight is the likelihood ratio. We state that this is the summary that should be presented to a court in every scientific assessment of evidential weight with supporting information about how it was constructed and on what it was based

    Influence of Advection on Measurements of the Net Ecosystem-Atmosphere Exchange of CO2 from a Very Tall Tower

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    In most studies of the net ecosystem-atmosphere exchange of CO2 (NEE) using tower-based eddy covariance( EC) systems it has been assumed that advection is negligible. In this study we use a scalar conservation budget method to estimate the contribution of advection to NEE measurements from a very tall tower in northern Wisconsin. We examine data for June-August 1997. Measured NEEo, calculated as the sum of the EC flux plus the rate of change of storage below the EC measurement level, is expected to be constant with measurement height, and we take the differences between levels as a measure of advection. We find that the average difference in total advection ΔFCadtot between 30 and 122 m is as large as 6 ÎŒmol m-2 s-1 during the morning transition from stable to convective conditions and the average difference ΔFCadtot between 122 and 396 m is as large as 4 ÎŒmol m-2 s-1 during daytime. For the month of July, advection between 30 and 122 m is 27% of the diurnally integrated NEE0 at 122 m, and advection between 122 and 396 m accounts for 5% of the NEE0 observed at 396 m. The observed differences of advection often have significant correlation with the vertical integral of wind speed within the same layer. This indicates that the horizontal advection contribution to NEE could be significant. Direct observations of the vertical gradient in CO2 show that ΔFCadtot cannot be explained by vertical advection alone. It is hypothesized that differing flux footprints and pooling of CO2 in the heterogeneous landscape causes the advection contribution.The magnitudes of the total advection component FCadtot of NEE at the 30 m level are roughly estimated by a linear extrapolation. A peak in FCadtot at 30 m of ~3 ÎŒmol m-2 s-1 during the morning transition is predicted for all three months.T he July integrated FCadtot is estimate to be 10% of the diurnally integrated NEE0 at 30 m

    Measurement of the Electric and Magnetic Polarizabilities of the Proton

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    The Compton scattering cross section on the proton has been measured at laboratory angles of 90∘^\circ and 135∘^\circ using tagged photons in the energy range 70--100 MeV and simultaneously using untagged photons in the range 100--148~MeV. With the aid of dispersion relations, these cross sections were used to extract the electric and magnetic polarizabilities, αˉ\bar{\alpha} and ÎČˉ\bar{\beta} respectively, of the proton. We find αˉ+ÎČˉ=(15.0±2.9±1.1±0.4)×10−4 fm3,\bar{\alpha}+\bar{\beta} = ( 15.0 \pm 2.9 \pm 1.1 \pm 0.4 ) \times 10^{-4} \: {\rm fm}^3, in agreement with a model-independent dispersion sum rule, and αˉ−ÎČˉ=(10.8±1.1±1.4±1.0)×10−4 fm3,\bar{\alpha}-\bar{\beta} = ( 10.8 \pm 1.1 \pm 1.4 \pm 1.0 ) \times 10^{-4} \: {\rm fm}^3, where the errors shown are statistical, systematic, and model-dependent, respectively. A comparison with previous experiments is given and global values for the polarizabilities are extracted.Comment: 35 pages, 11 PostScript figures, uses RevTex 3.

    Thermal Particle Creation in Cosmological Spacetimes: A Stochastic Approach

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    The stochastic method based on the influence functional formalism introduced in an earlier paper to treat particle creation in near-uniformly accelerated detectors and collapsing masses is applied here to treat thermal and near-thermal radiance in certain types of cosmological expansions. It is indicated how the appearance of thermal radiance in different cosmological spacetimes and in the two apparently distinct classes of black hole and cosmological spacetimes can be understood under a unifying conceptual and methodological framework.Comment: 17 pages, revtex (aps, eqsecnum), submitted to PRD, April 199

    Assessing the impact of forest structure disturbances on the arboreal movement and energetics of orangutans—An agent-based modeling approach

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    This is the final version. Available from Frontiers Media via the DOI in this record. Data availability statement: The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found in the article/Supplementary material.Agent-based models have been developed and widely employed to assess the impact of disturbances or conservation management on animal habitat use, population development, and viability. However, the direct impacts of canopy disturbance on the arboreal movement of individual primates have been less studied. Such impacts could shed light on the cascading effects of disturbances on animal health and fitness. Orangutans are an arboreal primate that commonly encounters habitat quality deterioration due to land-use changes and related disturbances such as forest fires. Forest disturbance may, therefore, create a complex stress scenario threatening orangutan populations. Due to forest disturbances, orangutans may adapt to employ more terrestrial, as opposed to arboreal, movements potentially prolonging the search for fruiting and nesting trees. In turn, this may lead to changes in daily activity patterns (i.e., time spent traveling, feeding, and resting) and available energy budget, potentially decreasing the orangutan's fitness. We developed the agent-based simulation model BORNEO (arBOReal aNimal movEment mOdel), which explicitly describes both orangutans' arboreal and terrestrial movement in a forest habitat, depending on distances between trees and canopy structures. Orangutans in the model perform activities with a motivation to balance energy intake and expenditure through locomotion. We tested the model using forest inventory data obtained in Sebangau National Park, Central Kalimantan, Indonesia. This allowed us to construct virtual forests with real characteristics including tree connectivity, thus creating the potential to expand the environmental settings for simulation experiments. In order to parameterize the energy related processes of the orangutans described in the model, we applied a computationally intensive evolutionary algorithm and evaluated the simulation results against observed behavioral patterns of orangutans. Both the simulated variability and proportion of activity budgets including feeding, resting, and traveling time for female and male orangutans confirmed the suitability of the model for its purpose. We used the calibrated model to compare the activity patterns and energy budgets of orangutans in both natural and disturbed forests. The results confirm field observations that orangutans in the disturbed forest are more likely to experience deficit energy balance due to traveling to the detriment of feeding time. Such imbalance is more pronounced in males than in females. The finding of a threshold of forest disturbances that affects a significant change in activity and energy budgets suggests potential threats to the orangutan population. Our study introduces the first agent-based model describing the arboreal movement of primates that can serve as a tool to investigate the direct impact of forest changes and disturbances on the behavior of species such as orangutans. Moreover, it demonstrates the suitability of high-performance computing to optimize the calibration of complex agent-based models describing animal behavior at a fine spatio-temporal scale (1-m and 1-s granularity).UKR

    The fables of pity: Rousseau, Mandeville and the animal-fable

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    Copyright @ 2012 Edinburgh University PressPrompted by Derrida’s work on the animal-fable in eighteenth-century debates about political power, this article examines the role played by the fiction of the animal in thinking of pity as either a natural virtue (in Rousseau’s Second Discourse) or as a natural passion (in Mandeville’s The Fable of the Bees). The war of fables between Rousseau and Mandeville – and their hostile reception by Samuel Johnson and Adam Smith – reinforce that the animal-fable illustrates not so much the proper of man as the possibilities and limitations of a moral philosophy that is unable to address the political realities of the state

    Stochastic Gravity: A Primer with Applications

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    Stochastic semiclassical gravity of the 90's is a theory naturally evolved from semiclassical gravity of the 70's and 80's. It improves on the semiclassical Einstein equation with source given by the expectation value of the stress-energy tensor of quantum matter fields in curved spacetimes by incorporating an additional source due to their fluctuations. In stochastic semiclassical gravity the main object of interest is the noise kernel, the vacuum expectation value of the (operator-valued) stress-energy bi-tensor, and the centerpiece is the (stochastic) Einstein-Langevin equation. We describe this new theory via two approaches: the axiomatic and the functional. The axiomatic approach is useful to see the structure of the theory from the framework of semiclassical gravity. The functional approach uses the Feynman-Vernon influence functional and the Schwinger-Keldysh close-time-path effective action methods which are convenient for computations. It also brings out the open systems concepts and the statistical and stochastic contents of the theory such as dissipation, fluctuations, noise and decoherence. We then describe the application of stochastic gravity to the backreaction problems in cosmology and black hole physics. Intended as a first introduction to this subject, this article places more emphasis on pedagogy than completeness.Comment: 46 pages Latex. Intended as a review in {\it Classical and Quantum Gravity

    The future of sovereignty in multilevel governance Europe: a constructivist reading

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    Multilevel governance presents a depiction of contemporary structures in EU Europe as consisting of overlapping authorities and competing competencies. By focusing on emerging non-anarchical structures in the international system, hence moving beyond the conventional hierarchy/anarchy dichotomy to distinguish domestic and international arenas, this seems a radical transformation of the familiar Westphalian system and to undermine state sovereignty. Paradoxically, however, the principle of sovereignty proves to be resilient despite its alleged empirical decline. This article argues that social constructivism can explain the paradox, by considering sovereign statehood as a process-dependent institutional fact, and by showing that multilevel governance can feed into this process

    In search of the authentic nation: landscape and national identity in Canada and Switzerland

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    While the study of nationalism and national identity has flourished in the last decade, little attention has been devoted to the conditions under which natural environments acquire significance in definitions of nationhood. This article examines the identity-forming role of landscape depictions in two polyethnic nation-states: Canada and Switzerland. Two types of geographical national identity are identified. The first – what we call the ‘nationalisation of nature’– portrays zarticular landscapes as expressions of national authenticity. The second pattern – what we refer to as the ‘naturalisation of the nation’– rests upon a notion of geographical determinism that depicts specific landscapes as forces capable of determining national identity. The authors offer two reasons why the second pattern came to prevail in the cases under consideration: (1) the affinity between wild landscape and the Romantic ideal of pure, rugged nature, and (2) a divergence between the nationalist ideal of ethnic homogeneity and the polyethnic composition of the two societies under consideration
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