The Link between General Relativity and Shape Dynamics

We show that one can construct two equivalent gauge theories from a linking theory and give a general construction principle for linking theories which we use to construct a linking theory that proves the equivalence of General Relativity and Shape Dynamics, a theory with fixed foliation but spatial conformal invariance. This streamlines the rather complicated construction of this equivalence performed previously. We use this streamlined argument to extend the result to General Relativity with asymptotically flat boundary conditions. The improved understanding of linking theories naturally leads to the Lagrangian formulation of Shape Dynamics, which allows us to partially relate the degrees of freedom.Comment: 19 pages, LaTeX, no figure

Características quimico-nutricionais da polpa de Caryocar coriaceum WITTM da região Meio-Norte do Brasil.

A espécie Caryocar coriaceum (pequi) é típica da região Meio-Norte do Brasil e de outras regiões do Nordeste, onde faz parte da sua culinária e do dia-a-dia nordestino. Objetivou-se neste trabalho avaliar características químicas e nutricionais da polpa de pequi, de origem dos Estados do Piauí e Maranhão. As seguintes características foram avaliadas: acidez total titulável (ATT), pH, e percentagens de gordura (GORD), proteína bruta (PB), fibra bruta (FB) e carboidratos (CT). Os resultados indicam que a variabilidade é bem maior entre indivíduos nas diversas populações que entre populações. Em geral, maiores teores de GORD e FB foram obtidos em indivíduos de populações do Maranhão, ao passo que em PB os maiores foram observados em indivíduos provenientes de populações do Piauí

The generation of magnetic fields by the Biermann battery and the interplay with the Weibel instability

An investigation of magnetic fields generated in an expanding bubble of plasma with misaligned temperature and density gradients (driving the Biermann battery mechanism) is performed. With gradient scales L, large-scale magnetic fields are generated by the Biermann battery mechanism with plasma 1, as long as L is comparable to the ion inertial length di. For larger system sizes, L/de 100 (where deis the electron inertial length), the Weibel instability generates magnetic fields of similar magnitude but with wavenumber kde0.2. In both cases, the growth and saturation of these fields have a weak dependence on mass ratio mi/me, indicating electron mediated physics. A scan in system size is performed at mi/me= 2000, showing agreement with previous results with mi/me= 25. In addition, the instability found at large system sizes is quantitatively demonstrated to be the Weibel instability. Furthermore, magnetic and electric energy spectra at scales below the electron Larmor radius are found to exhibit power law behavior with spectral indices -16/3 and -4/3, respectively

Radiative Corrections to the Aharonov-Bohm Scattering

We consider the scattering of relativistic electrons from a thin magnetic flux tube and perturbatively calculate the order $\alpha$, radiative correction, to the first order Born approximation. We show also that the second order Born amplitude vanishes, and obtain a finite inclusive cross section for the one-body scattering which incorporates soft photon bremsstrahlung effects. Moreover, we determine the radiatively corrected Aharonov-Bohm potential and, in particular, verify that an induced magnetic field is generated outside of the flux tube.Comment: 14 pages, revtex, 3 figure

Evolução e interação entre a produção e o preço das frutas no Estado do Pará.

As frutas apresentaram consistente superávit, em 2005, de R$32,52 milhões, no comércio interestadual do Pará. A produção se estabilizou no patamar de 1,4 milhões de toneladas e os preços em R$ 160,00 por tonelada, entre 2000 e 2005. O objetivo do trabalho foi analisar o comportamento das quantidades e dos preços das frutas paraenses, no período de 1985 a 2005. Utilizaram-se o método da taxa de crescimento, a construção de índices de preços e de quantidades e análise de regressão para determinar o crescimento, a evolução e a interação causal entre quantidade e preço. Os resultados mostraram que a produção de frutas cresceu até 1995, depois apresentou tendência de queda até 2000 e, a partir deste ponto, se estabilizou. Os preços apresentaram tendência de queda no período. As frutas extrativas apresentaram baixo coeficiente de elasticidade-preço (0,114), caracterizando a oferta como fortemente inelástica a preço. Conclui-se que a receita bruta das frutas extrativas é fortemente sensível às variações da produção

Dinâmica do mercado de frutas na mesorregião Nordeste paraense no período de 1985-2005: produção e preços.

Na mesorregião Nordeste Paraense, a fruticultura em expansão cria oportunidades direcionadas ao abastecimento das agroindústrias beneficiadoras de polpas de frutas, com significativa participação do município de Tomé-Açu. A análise de mercado com base nos resultados econométricos analisou a dinâmica do mercado frutícola utilizando o modelo de equações simultâneas, ajustado pela técnica do Método Generalizado dos Momentos (MGM). O comportamento do mercado indicou demanda e oferta inelástica a preço e elasticidade renda estadual, apontando significativo incremento na renda do consumidor. Os custos dos salários influenciaram diretamente no volume de produção de frutas na mesorregião. O mercado é promissor, porém há desequilíbrio entre a oferta e a demanda de frutas, com fraco dinamismo de mercado

On the Nonabelian Aharonov Bohm Scattering of Spinless Particles

The Aharonov Bohm scattering for spinless, isospin 1/2, particles interacting through a nonabelian Chern-Simons field is studied. Starting from the relativistic quantum field theory and using a Coulomb gauge formulation, the one loop renormalization program is implemented. Through the introduction of an intermediary cutoff, separating the regions of high and low integration momentum, the nonrelativistic limit is derived. The next to leading relativistic approximation is also determined. In this approach quantum field theory vacuum polarization effects are automatically incorporated.Comment: 20 pages, 8 figures, revtex. Misspelled reference corrected and new references adde

Fate of conjugated natural and synthetic steroid estrogens in crude sewage and activated sludge batch studies

This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/es801952h.Steroids are excreted from the human body in the conjugated form but are present in sewage influent and effluent as the free steroid, the major source of estrogenic activity observed in water courses. The fate of sulfate and glucuronide conjugated steroid estrogens was investigated in batch studies using activated sludge grown on synthetic sewage in a laboratory-scale Husmann simulation and crude sewage from the field. A clear distinction between the fate of sulfate and glucuronide conjugates was observed in both matrices, with sulfated conjugates proving more recalcitrant and glucuronide deconjugation preferential in crude sewage. For each conjugate, the free steroid was observed in the biotic samples. The degree of free steroid formation was dependent on the conjugate moiety, favoring the glucuronide. Subsequent degradation of the free steroid (and sorption to the activated sludge solid phase) was evaluated. Deconjugation followed the first order reaction rate with rate constants for 17α-ethinylestradiol 3-glucuronide, estriol 16α-glucuronide, and estrone 3-glucuronide determined as 0.32, 0.24, and 0.35 h respectively. The activated sludge solid retention time over the range of 3−9 days had 74 to 94% of sulfate conjugates remaining after 8 h. In contrast, a correlation between increasing temperature and decreasing 17α-ethinylestradiol 3-glucuronide concentrations in the activated sludge observed no conjugate present in the AS following 8 h at 22 °C Based on these batch studies and literature excretion profiles, a hypothesis is presented on which steroids and what form (glucuronide, sulfate, or free) will likely enter the sewage treatment plant.EPSR

In situ and low-cost monitoring of particles falling from freshwater animals: from microplastics to parasites

A simple and low-cost method of monitoring and collecting particulate matter detaching from (or interacting with) aquatic animals is described using a novel device based on an airlift pump principle applied to floating cages. The efficiency of the technique in particle collection is demonstrated using polyethylene microspheres interacting with a cyprinid fish (Carassius carassius) and a temporarily parasitic stage (glochidia) of an endangered freshwater mussel (Margaritifera margaritifera) dropping from experimentally infested host fish (Salmo trutta). The technique enables the monitoring of temporal dynamics of particle detachment and their continuous collection both in the laboratory and in situ, allowing the experimental animals to be kept under natural water quality regimes and reducing the need for handling and transport. The technique can improve the representativeness of current experimental methods used in the fields of environmental parasitology, animal feeding ecology and microplastic pathway studies in aquatic environments. In particular, it makes it accessible to study the physiological compatibility of glochidia and their hosts, which is an essential but understudied autecological feature in mussel conservation programs worldwide. Field placement of the technique can also aid in outreach programs with pay-offs in the increase of scientific literacy of citizens concerning neglected issues such as the importance of fish hosts for the conservation of freshwater mussels.We thank Zbyněk Janči and Bohumil Dort for the help in the field, the nature conservation authorities for providing permits and access to the research area in Borová Lada and two anonymous reviewers for their helpful comments on an earlier draft. All experiments were in compliance with the current laws of the Czech Republic Act No. 246/1992 coll. on the protection of animals against cruelty

A 27-year review of mergers and acquisitions research in 27 leading management journals

This study contributes to the existing body of knowledge on mergers and acquisitions (M&As) by providing a systematic review of over 500 academic articles across 27 management journals over a 27-year time frame. There appears to be a mixture of empirical and conceptual articles, with a larger proportion being empirical but an increasing number leaning towards a conceptual nature. Our findings show that most studies follow a quantitative approach and use large samples, mostly originating from existing databases. There is an emergence of thematic areas related to the strategic factors influencing M&As, but with the human dimension, gaining increasing attention over time.authorsversionpublishe