13,923 research outputs found

    The performance of farm animal assessment

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    This paper argues that the current drive towards greater use of animal-based measures for welfare assessment raises important issues for how farm visits by welfare assessors are performed. As social scientists, we employ a number of contemporary social science ideas to offer a new approach to examining the practice and performance of farm animal assessment. We identify key findings from a recent study of contemporary farm assessment and speculate upon what some of the challenges of introducing animal-based measures may be. We conclude by arguing for a greater awareness of how sets of knowledge are made, circulated, practiced and become an integral component of the procedures, practices and discourses around farm animal welfare assessment in farm assuranc

    On Endogenous Growth: The Implications of Environmental Externalities

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    This paper uses an endogenous growth model to examine the interaction between trade, economic growth, and the environment. We find that whether trade enhances or retards growth depends on the relation between factor intensities of exportable, importable, and R&D and the relative abundance of the factor R&D uses more intensively. Depending on the intertemporal elasticity of substitution, the long-run rate of economic growth changes with environmental externalities. Concerns about the environment can explain a significant part of cross-country difference in growth rates. For the empirically reported range of the elasticity of intertemporal substitution, countries which care more about the environment grow faster. The effects of trade on the environment and welfare depend on the elasticities of supply for the two traded goods, the terms of trade effect on growth, and pollution intensities. The decentralized and Pareto optimal growth rates are, in general, different. The market growth rate is bigger than the optimal rate the larger the degree of monopoly power in the innovation sector and the stronger the effects of environmental externalities. The policy implications of this divergence are discussed. We also consider numerical exercises to broaden the insights from the analytical results and allow for incorporating pollution abatementEnvironmental Economics and Policy, F11, O31, O41, Q20,

    Response of Marine‐Terminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics

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    Recent observations indicate that many marine‐terminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to long‐term trends in climate forcing. In this study, we describe a simple two‐stage model that accurately emulates the response to external forcing of marine‐terminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marine‐terminating glacier response to forcing. We find that there are two time scales that characterize the stable glacier response to external forcing, a fast time scale of decades to centuries, and a slow time scale of millennia. These two time scales become unstable at different thresholds of bed slope, indicating that there are distinct slow and fast forms of the marine ice sheet instability. We derive simple expressions for the approximate magnitude and transient evolution of the stable glacier response to external forcing, which depend on the equilibrium glacier state and the strength of nonlinearity in forcing processes. The slow response rate of marine‐terminating glaciers indicates that current changes at some glaciers are set to continue and accelerate in coming centuries in response to past climate forcing and that the current extent of change at these glaciers is likely a small fraction of the future committed change caused by past climate forcing. Finally, we find that changing the amplitude of natural fluctuations in some nonlinear forcing processes, such as ice shelf calving, changes the equilibrium glacier state

    Environment in Three Classes of Endogenous Growth Models

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    The implications of environmental externalities are studied within three classes of endogenous growth models viz. the linear technology models, the human capital models, and the R&D and innovation models. The long-run rate of economic growth changes when environmental extemalities are introduced; the direction of change depends on the severity of extemalities and the intertemporal elasticity of substitution. The presence of environmental externalities cause the decentralized growth rate to diverge from the efficient rate. Which rate is bigger than the other depends, among other things, on the valuation of consumption relative to environmental quality. Several policy changes to align the two paths are discussed. The models are calibrated to U.S. data.Environmental Economics and Policy, International Development,

    Tentative Detection of the Rotation of Eris

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    We report a multi-week sequence of B-band photometric measurements of the dwarf planet Eris using the {\it Swift} satellite. The use of an observatory in low-Earth orbit provides better temporal sampling than is available with a ground-based telescope. We find no compelling evidence for an unusually slow rotation period of multiple days, as has been suggested previously. A \sim1.08 day rotation period is marginally detected at a modest level of statistical confidence (\sim97%). Analysis of the combination of the SwiftSwift data with the ground-based B-band measurements of \citet{2007AJ....133...26R} returns the same period (\sim1.08 day) at a slightly higher statistical confidence (\sim99%).Comment: Accepted to Icarus 2008-Aug-19. 19 pages total, including 4 figures and 1 tabl

    Minimal kernels of Dirac operators along maps

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    Let MM be a closed spin manifold and let NN be a closed manifold. For maps f ⁣:MNf\colon M\to N and Riemannian metrics gg on MM and hh on NN, we consider the Dirac operator Dg,hfD^f_{g,h} of the twisted Dirac bundle ΣMRfTN\Sigma M\otimes_{\mathbb{R}} f^*TN. To this Dirac operator one can associate an index in KOdim(M)(pt)KO^{-dim(M)}(pt). If MM is 22-dimensional, one gets a lower bound for the dimension of the kernel of Dg,hfD^f_{g,h} out of this index. We investigate the question whether this lower bound is obtained for generic tupels (f,g,h)(f,g,h)

    Exchange Rates and U.S. Foreign Direct Investment in the Global Processed Food Industry

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    This paper focuses on estimating the effects of the real FDI-weighted exchange rate on real U.S. foreign direct investment (FDI) in the global processed food industry. We use a straightforward production possibility framework as our theoretical basis to demonstrate the shift of production between countries on the basis of exchange rate fluctuations. The log-log regression model, derived from the theoretical model, gives statistically robust results to show that for the years 1983 to 2002, the exchange rate fluctuations, the level of fixed capital in the U.S. food industry, and the cost of materials in both the United States and abroad were major determinants of the stock of U.S. FDI in the global processed food industry. As the dollar appreciated, U.S. FDI increased. An overall conclusion is that countries with an undervalued exchange rate will experience increased FDI. Countries with overvalued exchange rates incur costs from lost export opportunities for domestic firms as well as discourage FDI.U.S. foreign direct investment (FDI), global processed food industry, FDI-weighted exchange rates, International Relations/Trade,

    Overview of the coordinated ground-based observations of Titan during the Huygens mission

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    Coordinated ground-based observations of Titan were performed around or during the Huygens atmospheric probe mission at Titan on 14 January 2005, connecting the momentary in situ observations by the probe with the synoptic coverage provided by continuing ground-based programs. These observations consisted of three different categories: (1) radio telescope tracking of the Huygens signal at 2040 MHz, (2) observations of the atmosphere and surface of Titan, and (3) attempts to observe radiation emitted during the Huygens Probe entry into Titan's atmosphere. The Probe radio signal was successfully acquired by a network of terrestrial telescopes, recovering a vertical profile of wind speed in Titan's atmosphere from 140 km altitude down to the surface. Ground-based observations brought new information on atmosphere and surface properties of the largest Saturnian moon. No positive detection of phenomena associated with the Probe entry was reported. This paper reviews all these measurements and highlights the achieved results. The ground-based observations, both radio and optical, are of fundamental importance for the interpretation of results from the Huygens mission

    Discovery of Temperate Latitude Clouds on Titan

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    Until now, all the clouds imaged in Titan's troposphere have been found at far southern latitudes (60°-90° south). The occurrence and location of these clouds is thought to be the result of convection driven by the maximum annual solar heating of Titan's surface, which occurs at summer solstice (2002 October) in this south polar region. We report the first observations of a new recurring type of tropospheric cloud feature, confined narrowly to ~40° south latitude, which cannot be explained by this simple insolation hypothesis. We propose two classes of formation scenario, one linked to surface geography and the other to seasonally evolving circulation, which will be easily distinguished with continued observations over the next few years

    Assassin Bug

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