Conserved current for the Cotton tensor, black hole entropy and equivariant Pontryagin forms

The Chern-Simons lagrangian density in the space of metrics of a 3-dimensional manifold M is not invariant under the action of diffeomorphisms on M. However, its Euler-Lagrange operator can be identified with the Cotton tensor, which is invariant under diffeomorphims. As the lagrangian is not invariant, Noether Theorem cannot be applied to obtain conserved currents. We show that it is possible to obtain an equivariant conserved current for the Cotton tensor by using the first equivariant Pontryagin form on the bundle of metrics. Finally we define a hamiltonian current which gives the contribution of the Chern-Simons term to the black hole entropy, energy and angular momentum.Comment: 13 page

Local Anomalies, Local Equivariant Cohomology and the Variational Bicomplex

The locality conditions for the vanishing of local anomalies in field theory are shown to admit a geometrical interpretation in terms of local equivariant cohomology, thus providing a method to deal with the problem of locality in the geometrical approaches to the study of local anomalies based on the Atiyah-Singer index theorem. The local cohomology is shown to be related to the cohomology of jet bundles by means of the variational bicomplex theory. Using these results and the techniques for the computation of the cohomology of invariant variational bicomplexes in terms of relative Gel'fand-Fuks cohomology introduced in [6], we obtain necessary and sufficient conditions for the cancellation of local gravitational and mixed anomalies.Comment: 36 pages. The paper is divided in two part

Effects of commercial enrichment diets on the nutritional value of the rotifer (Brachionus plicatilis)

12 páginas, 4 tablasThe rotifer, Brachionusplicatifis, pre-fed on baker’s yeast, was enriched for 6 h with three commercial products from Artemia Systems S.A., namely Protein Selco (microcapsules), Dry Selco (microparticles) and Super Selco (an emulsion containing high levels of n-3 HUFA). The biochemical composition (protein, carbohydrate, total lipid, lipid classes and fatty acids) and dry weight ofthe rotifers before and after the enrichment experiments were studied. Two of the enrichers, Dry Selco and Super Selco, are rich in lipid but poor in protein and carbohydrate. Protein Selco contains lipid as well as protein and carbohydrate. The biochemical composition and the dry weight of the rotifers were changed after 6 h of enrichment. The percentage of protein and lipid increased with all of the three enrichers and the percentage of carbohydrate decreased slightly. Rotifer dry weight increased in rotifers enriched on Protein Selco. Phospholipids, sterol esters+ waxes, triacylglycerols and free fatty acids increased after the enrichment with the three enrichers while sterols slightly decreased when the rotifers were fed on Protein Selco. The fatty acid content of the rotifers increased after the enrichment with all ofthe enrichers and this increase was particularly apparent in the case of n-3 HUFAs (20: Sn-3 and 22 : 6n-3).This work was supported by the contract-project “ Larval Nutrition of Turbot” with the fish farm Cultivo de Peces S.A. (CULTIPECSA).Peer reviewe

The multidimensional role of social entrepreneurship: A case study approach within an international project context

Social entrepreneurship creates social value and has a multidimensional impact (e.g. economic, environmental, cultural). This is related to the complexity and multidimensional approaches to current societal problems such as climatic changes and socioeconomic crises. The paper explores this multidimensionality by presenting three Portuguese case studies of social entrepreneurship operating in diverse domains. The study is based on primary and secondary data on the selected social enterprises. The analysis explores the motivations and constraints in forming a social enterprise and the impact of entrepreneurial activity. There is evidence of multiple roles played by these entrepreneurial agents, and, therefore, their critical role in the response to the problems that current societies face.info:eu-repo/semantics/publishedVersio

Very Low-grade Metamorphic Evolution of Pelitic Rocks under High-pressure/Low-temperature Conditions, NW New Caledonia (SW Pacific)

The P-T gradient in a Late Eocene low-T high-P metamorphic belt in northern New Caledonia increases from SW to NE. Metapelites in the pumpellyite-prehnite and blueschist zones contain lawsonite, Mg-carpholite, Fe-stilpnomelane and Fe-glaucophane. Thermodynamic calculations indicate a progression of metamorphic conditions from less than 0·3 GPa and 250°C in a kaolinite-bearing rock in the SW, up to 1·5 GPa and 410°C in a lawsonite-glaucophane-bearing sample in the NE of the Diahot terrane. Through a multi-method investigation of phyllosilicates, organic matter and fluid inclusions, we demonstrate that the evolution of organic matter and illite crystallinity depends strongly on the evolution of the P-T path with time. In addition, we show that the illite-muscovite b cell dimension provides a robust estimate of maximum pressure reached in low-temperature domains with polyphase metamorphic histories, despite subsequent high-temperature-low-pressure events. Fluid inclusion study reveals an isothermal decompression in the Diahot terran

Using EcoYieldSAFE to compare soil carbon dynamics under future climate in two contrasting agroforestry systems

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Direct photons in d+Au collisions at s_(NN)**(1/2)=200GeV with STAR

Results are presented of an ongoing analysis of direct photon production in s_(NN)=200GeV deuteron-gold collisions with the STAR experiment at RHIC. A significant excess of direct photons is observed near mid-rapidity 0<y<1 and found to be consistent with next-to-leading order pQCD calculations including the contribution from fragmentation photons.Comment: 4 pages, 4 figures, HotQuarks 200

Saturation and geometric scaling in DIS at small x

We present various aspects of the saturation model which provides good description of inclusive and diffractive DIS at small x. The model uses parton saturation ideas to take into account unitarity requirements. A new scaling predicted by the model in the small x domain is successfully confronted with the data.Comment: Presented at New Trends in HERA Physics 2001, Ringberg Castle, Tegernsee, Germany, 17-22 June 2001, minor corrections, some references adde