In recent years, there has been renewed interest in the question of whether Ronald Dworkin was correct to allege that legal positivists are unable to account for theoretical disagreement about law. However, relatively little attention has been paid to the related question of who can best account for agreement about law. An important exception is Brian Leiter’s argument that there is massive and pervasive agreement in legal judgments and that positivism can account for this agreement but Dworkin cannot. In this article, I argue that Dworkin can account for such agreement, and that his explanation is no less straightforward than the positivist’s. I further contend that Leiter’s strategy for explaining theoretical disagreement is weakened once we recognise that Dworkin has a plausible explanation of agreement in legal judgments. I conclude by exploring how we might choose between the positivist’s and Dworkin’s competing explanations of agreement in legal judgments.

In 2008, avian bornaviruses (ABV) were identified as the cause of proventricular dilatation disease (PDD). PDD is a significant condition of captive parrots first identified in the late 1970s. ABV infection has subsequently been shown to be widespread in wild waterfowl across the United States and Canada where the virus infects 10–20% of some populations of ducks, geese and swans. In most cases birds appear to be healthy and unaffected by the presence of the virus; however, infection can also result in severe non-suppurative encephalitis and lesions similar to those seen in parrots with PDD. ABVs are genetically diverse with seven identified genotypes in parrots and one in canaries. A unique goose genotype (ABV-CG) predominates in waterfowl in Canada and the northern United States. ABV appears to be endemic in North American waterfowl, in comparison to what appears to be an emerging disease in parrots. It is not known whether ABV can spread between waterfowl and parrots. The discovery of ABV infection in North American waterfowl suggests that European waterfowl should be evaluated for the presence of ABV, and also as a possible reservoir species for Borna disease virus (BDV), a related neurotropic virus affecting horses and sheep in central Europe. Although investigations have suggested that BDV is likely derived from a wildlife reservoir, for which the shrew and water vole are currently prime candidates, we suggest that the existence of other mammalian and avian reservoirs should not be discounted.

Joseph Raz famously argues that given that the law necessarily claims authority and given the account of authority he provides, exclusive legal positivism is the only tenable theory of law. In this article, I contend that even if one accepts that the law necessarily claims authority and that Raz's account of authority is correct, it does not follow that exclusive legal positivism is the only tenable theory of law. This is because even if the law necessarily claims authority, it need not be capable of satisfying the requirements for possessing authority laid down by the correct account of authority. Thus, even if exclusive legal positivism is the only theory of law according to which the law can satisfy those requirements, this does not show that exclusive legal positivism is correct.

We present photometry and spectroscopy of the peculiar Type II supernova SN 2010jp, also named PTF10aaxi. The light curve exhibits a linear decline with a relatively low peak absolute magnitude of only −15.9 (unfiltered), and a low radioactive decay luminosity at late times that suggests a low synthesized nickel mass of about 0.003 M⊙ or less. Spectra of SN 2010jp display an unprecedented triple-peaked Hα line profile, showing: (1) a narrow central component that suggests shock interaction with a dense circumstellar medium (CSM); (2) high-velocity blue and red emission features centered at −12,600 and +15,400 km s−1; and (3) very broad wings extending from −22,000 to +25,000 km s−1. We propose that this line profile indicates a bipolar jet-driven explosion, with the central component produced by normal SN ejecta and CSM interaction at mid and low latitudes, while the high-velocity bumps and broad line wings arise in a nonrelativistic bipolar jet. Jet-driven SNe II are predicted for collapsars resulting from a wide range of initial masses above 25 M⊙, especially at the sub-solar metallicity consistent with the SN host environment. It also seems consistent with the apparently low 56Ni mass that may accompany black hole formation. We speculate that the jet survives to produce observable signatures because the star's H envelope was very low mass, having been mostly stripped away by the previous eruptive mass loss.

The two workhorse models of trade, Heckscher-Ohlin and Ricardo-Viner, provide leverage in explaining how societal groups divide over trade protection. Tension between the two trade models has significantly influenced the scholarship of trade politics, with explanations of trade politics adopting either the factor-based approach or the industry-based framework. No study has investigated how changes in factor mobility as a continuous variable influence the change in trade protection as a policy outcome. Building on recent scholarship on factor mobility, this article models explicitly how intersectoral labor (im)mobility and political competition between parties affect changes in trade protection in majoritarian democracies. The theoretical model predicts that when intersectoral labor mobility decreases governments in majoritarian democracies are more likely to raise trade barriers. We test this prediction in a time-series, cross-sectional sample of 32 OECD and non-OECD majoritarian democracies observed between 1980 and 2000. The empirical results corroborate our theory and remain robust when we control for alternative explanations, employ different estimation techniques, and use different measures of trade protection.

The working group is pursuing activities co-organized and/or co-sponsored by UN, ESA, NASA, JAXA, UNESCO, COSPAR, IAU and others for the world-wide development of basic space science.

What set of domestic institutions most affect bilateral trade flows? Extant research emphasizes security institutions or democratic political institutions. We agree that domestic institutions matter, but not the ones previously identified. Rather, the key set of institutions influencing trade flows are those that protect property rights. These market-protecting institutions, such as the establishment of banking and insurance laws and common standards of measurement, promote trade by lowering the transaction costs of commercial exchange. An empirical analysis of bilateral trade flows employing a number of estimation methods and operationalizations of the key concept support our market-protecting institutions argument.

Ronald Dworkin has repeatedly claimed that the debate between moral objectivists and anti-objectivists (which I shall call “the meta-ethical debate”) has no implications for legal practice or theory. He has offered two main arguments to support this claim. The first is that while assertions about the truth or falsity of moral objectivism may be intelligible, they are irrelevant to legal practice and theory. The second is more radical, namely, that no assertion can be given an intelligible meta-ethical reading. In this article, I contend that neither argument is sound. The first argument overlooks the variety of ways in which the meta-ethical debate could impact upon legal practice or theory. It also rests upon an uncharitable interpretation of that debate. As for the second argument, Dworkin is correct in claiming that statements seemingly about the truth or falsity of moral objectivism can instead be interpreted as moral statements, but he is wrong to claim that this is the only intelligible reading they can be given.

A suspected glyphosate-resistant Italian ryegrass biotype was collected from a filbert orchard near Portland, OR, where glyphosate was applied multiple times per year for about 15 yr. Greenhouse studies were conducted to determine if this biotype was glyphosate resistant. The plants were sprayed with glyphosate (0.01 to 3.37 kg ae ha−1) 14 d after planting and shoot biomass was determined 3 wk after herbicide treatment. Based on the dose–response experiments conducted in the greenhouse, the suspected Italian ryegrass biotype was approximately fivefold more resistant to glyphosate than the susceptible biotype. Plants from both susceptible and resistant biotypes were treated with glyphosate (0.42 and 0.84 kg ha−1) and shikimic acid was extracted 12, 24, 48, and 96 h after treatment. The susceptible biotype accumulated between three and five times more shikimic acid than did the resistant biotype. Leaf segments from both susceptible and resistant biotypes were incubated with different glyphosate concentrations (0.5 to 3000 μM) for 14 h under continuous light. Shikimic acid was extracted from each leaf segment and quantified. At a concentration up to 100 μM, leaf segments from the susceptible biotype accumulated more shikimic acid than leaf segments from the resistant biotype. The epsps gene was amplified and sequenced in both susceptible and resistant biotypes; however, no amino acid change was found in the resistant biotype. The level of resistance in this biotype is similar to that reported for a glyphosate-resistant Italian ryegrass biotype from Chile.

Knowledge of the spatial distribution of bed lubrication regimes, i.e. frozen vs wet conditions, is crucial for understanding ice-sheet flow. Radar sounding can probe differing reflectivities between wet and frozen beds, but is limited by uncertainty in attenuation within the ice of bed echoes. Here we present two methods to estimate attenuation: (1) wide-angle radar sounding, in which source and receiver locations are varied so as to vary propagation path length, and thus echo amplitude; and (2) profiling, inwhich similar variations are obtained by sounding through varying ice thicknesses (assuming constant bed reflectivity). Siple Dome, West Antarctica, provides unusually favorable circumstances for application of these methods: the bed beneath Siple Dome is flat and uniform in its radar reflectivity, while ice thickness varies by several hundred meters. Wide-angle data 4 km from the summit yield an estimate for characteristic attenuation length of 124 m (35 dB km–1 loss), whereas profiling yields an estimate of 168 m.The difference between estimates is modest compared to the range of attenuation lengths reported in the literature. It may nonetheless prove informative by bounding effects of two ice properties to which the methods respond differently: (1) wide-angle sounding sampled relatively warm (lossy) ice beneath the summit, whereas the profiling method sampled relatively cold ice beneath the flanks as well; and (2) strain-induced crystal orientation fabrics and resulting dielectric anisotropy in the ice would vary from summit to flank, and may influence wide-angle sounding more strongly than profiling.

To investigate the accuracy of a model [Giese et al., 1998, Biochemistry 37:1094–1100 and Mathews et al., 1999, J Mol Biol 288:911–940] that predicts the stability of RNA hairpin loops, optical melting studies were conducted on sets of hairpins previously determined to have unusually stable thermodynamic parameters. Included were the tetraloops GNRA and UNCG (where N is any nucleotide and R is a purine), hexaloops with UU first mismatches, and the hairpin loop of the iron responsive element, CAGUGC. The experimental values for the GNRA loops are in excellent agreement (ΔG°37 within 0.2 kcal/mol and melting temperature (TM) within 4 °C) with the values predicted by the model. When the UNCG hairpin loops are treated as tetraloops, and a bonus of 0.8 kcal/mol included in the prediction to account for the extra stable first mismatch (UG), the measured and predicted values are also in good agreement (ΔG°37 within 0.7 kcal/mol and TM within 3 °C). Six hairpins with unusually stable UU first mismatches also gave good agreement with the predictions (ΔG°37 within 0.5 kcal/mol and TM within 8 °C), except for hairpins closed by wobble base pairs. For these hairpins, exclusion of the additional stabilization term for UU first mismatches improved the prediction (ΔG°37 within 0.1 kcal/mol and TM within 3 °C). Hairpins with the iron-responsive element loop were not predicted well by the model, as measured ΔG°37 values were at least 1 kcal/mol greater than predicted.

This article examines the properties and relative strengths of two approaches to reducing barriers to trade among nations: multilateral negotiating rounds versus regional economic blocs. Instead of focusing on the net welfare gains—the macro-level effects—that result either from each member of the system reducing trade barriers to all its partners (rounds) or from reductions among a subset of states (blocs), the analysis focuses on the institutional features (group size and the voting and enforcement mechanisms) that may affect individual nations' micro-level motivations to participate in and abide by certain trade arrangements. Existing models in formal theory are used to analyze these approaches in terms of voting games and collective action models.

A significant negative correlation was found between the quantity of acetone-extractable phenolic compounds and the degree of enzyme polymorphism in eight eastern North American populations of Umbilicaria americana. In sites higher elevations, where UV irradiance was more intense, phenolic levels were significantly lower and within-stand enzyme variability significantly greater than in low elevation sites. Similarly, the phenolic content of thalli collected in Ontario, Canada, over a 16-month sampling period was negatively correlated with mean monthly UV-B irradiance.