5,418 research outputs found

    Of mice and missiles: An Austrian School economic appraisal of Lucas v South Carolina Coastal Commission

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    This paper argues that to maximize the utility of society, a legal system must precisely define and strictly enforce property rights; Chapter I provides a theoretical economic framework by which various policy and judicial decisions affecting property rights can be considered; Chapter II examines the proper role for a legal system as well as the historical and United States Constitutional respect for property rights. Secondly, the devolution of this earlier respect for property rights is discussed by examining case decisions which tolerate to a greater degree, force with respect to physical property. Finally, the notion of the regulatory taking is considered; Chapter III looks more specifically at a recent regulatory takings case heard by the U.S. Supreme Court; Lucas v. South Carolina Coastal Commission. It is discussed using the economic tools of analysis presented in Chapter I with references to the legal case history addressed in Chapter II

    Hymn to the Founder

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    In praise of Chaminad

    Fractional Stokes-Einstein and Debye-Stokes-Einstein relations in a network forming liquid

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    We study the breakdown of the Stokes-Einstein (SE) and Debye-Stokes-Einstein (DSE) relations for translational and rotational motion in a prototypical model of a network-forming liquid, the ST2 model of water. We find that the emergence of ``fractional'' SE and DSE relations at low temperature is ubiquitous in this system, with exponents that vary little over a range of distinct physical regimes. We also show that the same fractional SE relation is obeyed by both mobile and immobile dynamical heterogeneities of the liquid

    The NIR to UV continuum of radio loud vs. radio quiet quasars

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    Starting from a sample of SDSS quasars appearing also in the 2MASS survey, we study the continuum properties of about 1000 objects observed in 8 bands, from NIR to UV. We construct the mean spectral energy distribution (SED) and compare and contrast the continua of radio loud (RLQ) and radio quiet (RQQ) objects. The SEDs of the two populations are significantly different in the sense that RLQs are redder, with power law spectral indices =-0.55+/-0.04 and =-0.31+/-0.01 in the spectral range between 10^14.5 and 10^15.35 Hz. This difference is discussed in terms of different extinctions, different disc temperatures, or slopes of the non-thermal component.Comment: 7 pages, 6 figures. To appear in MNRA

    Effects of a saponin fraction extracted from Trigonella foenum-graecum L. and two commercially available saponins on sex ratio and gonad histology of Nile tilapa fry, Oreochromis niloticus (L.)

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    Over three million tonnes (t) of tilapia, mostly Nile tilapia (Oreochromis niloticus, L.), are produced annually making it the second most abundantly produced freshwater fish (FAO, 2010). Tilapia are mouthbreeders that often produce stunted populations under pond conditions; one means of prevention is to produce all-male fish with the additional advantage that males usually grow faster than females. All-male populations can be achieved by supplementing feed with androgens such as 17-α-Methyltestosterone (MT) during days 10–25 post-hatch (Pandian and Sheela, 1995). However, MT is considered to be carcinogenic (Velazquez and Alter, 2004), and Hulak et al. (2008) also showed that effluents of systems in which carp were fed diets containing MT caused masculinization of female fish. Furthermore, in aquaculture the application of hormones to fish destined for human consumption is prohibited in the European Union under directive 96/22/EC, article 5, which also prohibits import of animal products produced with hormones. Kwon et al. (2000) showed that Fadrozole, a non-steroidal compound, caused masculinization in tilapia by inhibiting aromatase, which is the enzyme responsible for the conversion of endogenous androgens to estrogens. Steinbronn et al. (2004) were able to show that a dose of 2000 ppm Quillaja saponins (Sigma S-2149) inhibited reproduction of tilapia after dietary application for 32 days to first-feeding fry, suggesting saponins as a possible alternative to MT. These secondary plant compounds consist of either a steroid or triterpenoid basic structure (aglycone or sapogenin) plus one or more sugar side chains (Francis et al., 2002a). In a previous experiment a saponin fraction from the soapbark tree (Quillaja saponaria M.) inhibited aromatase in vitro (Golan et al., 2008). The fenugreek plant (Trigonella foenum-graecum L), widely cultivated in the Middle East and Asia, also has a high saponin content. The experiment was therefore conducted to test whether saponin fractions from Q. saponaria and from T. foenum-graecum were able to influence the sex ratio and gonad histology of Nile tilapia

    Cosmic Ray Cradles in the Galaxy

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    The search for the origin of high-energy cosmic rays has made significant progress in the past decade. By including multi-messenger methods, the general picture of the presence of a galactic component at low energies and an extragalactic one at the highest energies has been strengthened. Yet, unambiguous proof of the exact origins of cosmic rays is still missing. This chapter will review localized regions in the galaxy, which, due to their high nonthermal emission, are likely cosmic ray cradles. What we can learn from combining theoretical modeling with multi-messenger observations of regions like the Cygnus X complex, the Eta Carinae, and the Galactic Center region will be discussed. How the investigation of such localized regions in the Milky Way will help to resolve the more than 100-year-old question: what is the origin of cosmic rays? will be reviewed

    Dynamical Behavior Near a Liquid-Liquid Phase Transition in Simulations of Supercooled Water

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    We examine the behavior of the diffusion coefficient of the ST2 model of water over a broad region of the phase diagram via molecular dynamics simulations. The ST2 model has an accessible liquid-liquid transition between low-density and high-density phases, making the model an ideal candidate to explore the impacts of the liquid-liquid transition on dynamics. We locate characteristic dynamical loci in the phase diagram and compare them with the previously investigated thermodynamic loci. The low-density liquid phase shows a crossover from non-Arrhenius to Arrhenius behavior, signaling the onset of a crossover from fragile-to-strong behavior. We explain this crossover in terms of the asymptotic approach of the low-density liquid to a random tetrahedral network, and show that the temperature dependence of the diffusion coefficient over a wide temperature range can be simply related to the concentration of defects in the network. Our findings thus confirm that the low-density phase of ST2 water is a well-defined metastable liquid.Comment: 21 pages, 9 figure

    Non-Gaussian Scatter in Cluster Scaling Relations

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    We investigate the impact of non-Gaussian scatter in the cluster mass-observable scaling relation on the mass and redshift distribution of clusters detected by wide area surveys. We parameterize non-Gaussian scatter by incorporating the third and forth moments (skewness and kurtosis) into the distribution P(Mobs|M). We demonstrate that for low scatter mass proxies the higher order moments do not significantly affect the observed cluster mass and redshift distributions. However, for high scatter mass indicators it is necessary for the survey limiting mass threshold to be less than 10^14 h^-1 Msol to prevent the skewness from having a significant impact on the observed number counts, particularly at high redshift. We also show that an unknown level of non-Gaussianity in the scatter is equivalent to an additional uncertainty on the variance in P(Mobs|M) and thus may limit the constraints that can be placed on the dark energy equation of state parameter w. Furthermore, positive skewness flattens the mass function at the high mass end, and so one must also account for skewness in P(Mobs|M) when using the shape of the mass function to constrain cluster scaling-relations.Comment: 6 Pages, 3 Figures, to be submitted to ApJ Letter
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