Fluctuating Commutative Geometry

We use the framework of noncommutative geometry to define a discrete model for fluctuating geometry. Instead of considering ordinary geometry and its metric fluctuations, we consider generalized geometries where topology and dimension can also fluctuate. The model describes the geometry of spaces with a countable number $n$ of points. The spectral principle of Connes and Chamseddine is used to define dynamics.We show that this simple model has two phases. The expectation value , the average number of points in the universe, is finite in one phase and diverges in the other. Moreover, the dimension $\delta$ is a dynamical observable in our model, and plays the role of an order parameter. The computation of is discussed and an upper bound is found, $< 2$. We also address another discrete model defined on a fixed $d=1$ dimension, where topology fluctuates. We comment on a possible spontaneous localization of topology.Comment: 7 pages. Talk at the conference "Spacetime and Fundamental Interactions: Quantum Aspects" (Vietri sul Mare, Italy, 26-31 May 2003), in honour of A. P. Balachandran's 65th birthda

Endometriosis: A Rare Cause of Large Bowel Obstruction.

Large bowel obstruction can result in significant morbidity and mortality, especially in cases of acute complete obstruction. There are many possible causes, the most common in adults being colorectal cancer. Endometriosis is a benign disease, and the most affected extragenital location is the bowel, especially the rectosigmoid junction. However, transmural involvement and acute occlusion are very rare events. We report an exceptional case of acute large bowel obstruction as the initial presentation of endometriosis. The differential diagnosis of colorectal carcinoma may be challenging, and this case emphasizes the need to consider intestinal endometriosis in females at a fertile age presenting with gastrointestinal symptoms and an intestinal mass causing complete large bowel obstruction.info:eu-repo/semantics/publishedVersio

Reação de cultivares comerciais de milho ao enfezamento, cercosporiose e helmintosporiose no Meio-Norte brasileiro.

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Fitomolestias identificadas na microrregiao do litoral piauiense: 1988-1997.

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Distribuição dos algodoeiros no nordeste do Brasil.

Zoneamento do nordeste para a cultura algodoeira.bitstream/item/33345/1/DISTRIBUICAO-DOS-ALGODOEIROS.pd

Topological low-temperature limit of Z(2) spin-gauge theory in three dimensions

We study Z(2) lattice gauge theory on triangulations of a compact 3-manifold. We reformulate the theory algebraically, describing it in terms of the structure constants of a bidimensional vector space H equipped with algebra and coalgebra structures, and prove that in the low-temperature limit H reduces to a Hopf Algebra, in which case the theory becomes equivalent to a topological field theory. The degeneracy of the ground state is shown to be a topological invariant. This fact is used to compute the zeroth- and first-order terms in the low-temperature expansion of Z for arbitrary triangulations. In finite temperatures, the algebraic reformulation gives rise to new duality relations among classical spin models, related to changes of basis of H.Comment: 10 pages, no figure

Elaboração e edição de bases carto-temáticas em ambiente SIG.

Resumo

Avaliação e manejo do solo com a tecnologia de corte e trituração visando a sustentabilidade do sistema de produção da agricultura familiar, com ênfase em alternativas ao uso do fogo na Amazônia.

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Caracteristicas culinarias e agronomicas de tres cultivares de macaxeira.

A macaxeira (Manihot esculenta (Crantz.), tambem chamada de aipim, mandioca de mesa e mandioca mansa em outras regioes do Brasil, se diferencia da mandioca brava ou industrial por apresentar baixo teor de acidocianidrico (HCN) nas raizes e possibilita colheita mais precocemente. Foram plantadas em marco de 1988 tres cultivares de macaxeira com o objetivo de avaliar as caracteristicas culinarias e agronomicas das mesmas. As cultivres foram: Jaburu (BGM 187), Rosa e Peixe. Foram feitas observacoes em varios caracteres botanicos e agronomicos das cultivares. Foi anotado o tempo de cozimento de cada cultivar. As cultivares Peixe e Rosa apresentaram melhores qualidades culinarias.bitstream/item/95951/1/CT420001.pd