Ocean Acidification: Legal and Policy Responses to Address Climate Change\u27s Evil Twin

Much attention has been devoted to the problem of global climate change, but the effects of carbon dioxide on the world’s oceans has been largely underappreciated. Oceanic absorption of carbon dioxide is working fundamental changes on ocean chemistry, increasing the acidity of the oceans, and threatening the stability of the oceans’ ecosystems. The United States has responded to these emergent threats with a policy agenda heavily oriented toward data production, but light on action that might reverse the course of ocean acidification. This Article contends that this policy approach is ill-suited to the known risks of intensifying ocean acidification. The author recommends a shift toward a more action-oriented policy agenda aimed at preventing ocean acidification from reaching perilous levels. In particular, this article recommends using the statutory tools already available under the Clean Water Act to preserve coastal carbon sinks, to establish more protective marine water quality standards for pH, and to implement regional TMDLs for carbon dioxide. The cost of delay is simply too high to forgo direct action to combat ocean acidification. Reprinted with permission from 20 N.Y.U. Envtl. L.J. 507 (2014)

Serological Changes Associated with Gill-Net Capture and Restraint in Three Species of Sharks

To investigate the biochemical effects of capture and restraint on sharks, 17 serum constituents were measured in three species (bonnethead shark Sphyrna tiburo, blacktip shark Carcharhinus limbatus, and bull shark C. leucas) after gill-net capture. The relative degree of capture effects on each animal was judged using an index of behavioral response devised for use in tag−recapture studies. Serum from each shark was assayed for glucose, creatinine, uric acid, sodium, chloride, potassium, inorganic phosphate, total and ionized calcium, total protein, albumin, globulin, alkaline phosphatase, lactate, lactate dehydrogenase, aspartate aminotransferase, and total iron. In addition, hematocrit was measured from whole blood for each shark. When correlated with the relative degree of capture effects, there were significant intraspecific changes in the concentration of potassium, lactate, inorganic phosphate, uric acid, alkaline phosphatase, aspartate aminotransferase, total and ionized calcium, and glucose. Significant interspecific differences in the concentration of sodium, chloride, potassium, total protein, albumin, globulin, lactate dehydrogenase, aspartate aminotransferase, ionized calcium, alkaline phosphatase, and glucose in minimally stressed animals also were observed. The study suggests that the deleterious effects of gill-net capture and restraint probably involve respiratory and metabolic acidosis and hypoglycemia as well as cellular damage. Species-specific and individual differences in the mortality of sharks caught in gill nets are likely related to an animal\u27s respiratory physiology and degree of struggling upon capture as well as to the extent of net entanglement around the gill area

The many faces of OSp(1|32)

We show that the complete superalgebra of symmetries, including central charges, that underlies F-theories, M-theories and type II string theories in dimensions 12, 11 and 10 of various signatures correspond to rewriting of the same OSp(1|32) algebra in different covariant ways. One only has to distinguish the complex and the unique real algebra. We develop a common framework to discuss all signatures theories by starting from the complex form of OSp(1|32). Theories are distinguished by the choice of basis for this algebra. We formulate dimensional reductions and dualities as changes of basis of the algebra. A second ingredient is the choice of a real form corresponding to a specific signature. The existence of the real form of the algebra selects preferred spacetime signatures. In particular, we show how the real d=10 IIA and IIB superalgebras for various signatures are related by generalized T-duality transformations that not only involve spacelike but also timelike directions. A third essential ingredient is that the translation generator in one theory plays the role of a central charge operator in the other theory. The identification of the translation generator in these algebras leads to the star algebras of Hull, which are characterized by the fact that the positive definite energy operator is not part of the translation generators. We apply our results to discuss different T-dual pictures of the D-instanton solution of Euclidean IIB supergravity.Comment: 30 pages, Latex, using lscape.st

K3 Orientifolds

We study string theory propagating on R^6 times K3 by constructing orientifolds of Type IIB string theory compactified on the T^4/Z_N orbifold limits of the K3 surface. This generalises the Z_2 case studied previously. The orientifold models studied may be divided into two broad categories, sometimes related by T-duality. Models in category A require either both D5- and D9-branes, or only D9-branes, for consistency. Models in category B require either only D5-branes, or no D-branes at all. This latter case is an example of a consistent purely closed unoriented string theory. The spectra of the resulting six dimensional N=1 supergravity theories are presented. Precise statements are made about the relation of the Z_N ALE spaces and D5-branes to instantons in the dual heterotic string theory.Comment: 34 pages in harvmac `b' option. Requires epsf.tex for 8 figures. Revised version (to appear in Nucl. Phys. B.) corrects typographical error

Symmetries of string, M and F-theories

The d=10 type II string theories, d=11 M-theory and d=12 F-theory have the same symmetry group. It can be viewed either as a subgroup of a conformal group OSp(1|64) or as a contraction of OSp(1|32). The theories are related by different identifications of their symmetry operators as generators of OSp(1|32). T- and S-dualities are recognized as redefinitions of generators. Some (s,t) signatures of spacetime allow reality conditions on the generators. All those that allow a real structure are related again by redefinitions within the algebra, due to the fact that the algebra OSp(1|32) has only one real realization. The redefinitions include space/space, time/time and space/time dualities. A further distinction between the theories is made by the identification of the translation generator. This distinguishes various versions of type II string theories, in particular the so-called *-theories, characterized by the fact that the P_0 generator is not the (unique) positive-definite energy operator in the algebra.Comment: contribution to the proceedings of the Gursey Memorial Conference II `M-theory and dualities', Istanbul, June 2000; 13 page

N=2 supergravity in five dimensions revisited

We construct matter-coupled N=2 supergravity in five dimensions, using the superconformal approach. For the matter sector we take an arbitrary number of vector-, tensor- and hyper-multiplets. By allowing off-diagonal vector-tensor couplings we find more general results than currently known in the literature. Our results provide the appropriate starting point for a systematic search for BPS solutions, and for applications of M-theory compactifications on Calabi-Yau manifolds with fluxes.Comment: 35 pages; v.2: A sign changed in a bilinear fermion term in (5.7

Partition functions of higher spin black holes and their CFT duals

We find black hole solutions of D=3 higher-spin gravity in the hs[\lambda] + hs[\lambda] Chern-Simons formulation. These solutions have a spin-3 chemical potential, and carry nonzero values for an infinite number of charges of the asymptotic W_{\infty}[\lambda] symmetry. Applying a previously developed set of rules for ensuring smooth solutions, we compute the black hole partition function perturbatively in the chemical potential. At \lambda =0, 1 we compare our result against boundary CFT computations involving free bosons and fermions, and find perfect agreement. For generic \lambda\ we expect that our gravity result will match the partition function of the coset CFTs conjectured by Gaberdiel and Gopakumar to be dual to these bulk theories.Comment: 28 pages; v2, added re