Gravitational Couplings of Intrinsic Spin

The gravitational couplings of intrinsic spin are briefly reviewed. A consequence of the Dirac equation in the exterior gravitational field of a rotating mass is considered in detail, namely, the difference in the energy of a spin-1/2 particle polarized vertically up and down near the surface of a rotating body is $\hbar\Omega\sin\theta$. Here $\theta$ is the latitude and $\Omega = 2GJ/(c^2 R^3)$, where $J$ and $R$ are, respectively, the angular momentum and radius of the body. It seems that this relativistic quantum gravitational effect could be measurable in the foreseeable future.Comment: LaTeX file, no figures, 16 page

Efeito de genótipo de algodoeiro com gene BT na biologia de Alabama Argillacea

Genótipo do algodoeiro; Alabama Argillaceabitstream/CNPA/20125/1/COMTEC314.pd

Colonização micorrízica e crescimento da videira (Vitis vinifera, Porta-Enxerto P1103) em solo com alto teor de cobre.

A aplicação de fungicidas cúpricos em vinhedos aumenta o teor de Cu no solo, potencializando a toxidez para a videira. Entretanto, tem sido relatado que os fungos micorrízicos arbusculares (FMA) podem propiciar efeito protetor às plantas em solos contendo excesso de metais pesados. O trabalho objetivou avaliar a colonização micorrízica e o crescimento da videira (porta-enxerto P1103) em solo contendo elevados teores de Cu. Avaliou-se seis tratamentos de inoculação com FMA (Dentiscutata heterogama, Gigaspora gigantea, Acaulospora morrowiae, A. colombiana, Rhizophagus clarus e R. irregularis), além de um não inoculado. Verificou-se que a colonização micorrízica da videira foi elevada (média de 33%), mesmo em solo contendo excesso de Cu. A inoculação dos isolados de FMA testados pouco influenciou o crescimento da videira, mas a inoculação com R. irregulares e R. clarus beneficiou a produção de massa seca das raízes das mudas.Resumo expandido

\u3ci\u3eIn Situ\u3c/i\u3e Degradability of Hand Harvested or Extrusa Samples of Tanzania Grass (\u3ci\u3ePanicum maximum\u3c/i\u3e, Jacq.)

In order to compare the in situ degradability of tanzania grass samples obtained as by extrusa or hand plucked, three ruminal fistulated cows were used in a completely randomized block design with split-plot scheme. Five grams of extrusa or hand harvested grasses were placed in nylon bags rumen incubated during 3, 6, 12, 24, 48, 96 and 120 hours. The degradability of DM, CP, NDF and ADF were, in this sequence, 62.59, 80.88, 50.73 and 46.65%, for hand harvested grass; and 79.53, 90.97, 71.21 and 65.68%, for extrusa. In situ degradability data of hand harvested samples were not reliable

Adult midgut expressed sequence tags from the tsetse fly Glossina morsitans morsitans and expression analysis of putative immune response genes

BACKGROUND: Tsetse flies transmit African trypanosomiasis leading to half a million cases annually. Trypanosomiasis in animals (nagana) remains a massive brake on African agricultural development. While trypanosome biology is widely studied, knowledge of tsetse flies is very limited, particularly at the molecular level. This is a serious impediment to investigations of tsetse-trypanosome interactions. We have undertaken an expressed sequence tag (EST) project on the adult tsetse midgut, the major organ system for establishment and early development of trypanosomes. RESULTS: A total of 21,427 ESTs were produced from the midgut of adult Glossina morsitans morsitans and grouped into 8,876 clusters or singletons potentially representing unique genes. Putative functions were ascribed to 4,035 of these by homology. Of these, a remarkable 3,884 had their most significant matches in the Drosophila protein database. We selected 68 genes with putative immune-related functions, macroarrayed them and determined their expression profiles following bacterial or trypanosome challenge. In both infections many genes are downregulated, suggesting a malaise response in the midgut. Trypanosome and bacterial challenge result in upregulation of different genes, suggesting that different recognition pathways are involved in the two responses. The most notable block of genes upregulated in response to trypanosome challenge are a series of Toll and Imd genes and a series of genes involved in oxidative stress responses. CONCLUSIONS: The project increases the number of known Glossina genes by two orders of magnitude. Identification of putative immunity genes and their preliminary characterization provides a resource for the experimental dissection of tsetse-trypanosome interactions

Homoclinic chaos in the dynamics of a general Bianchi IX model

The dynamics of a general Bianchi IX model with three scale factors is examined. The matter content of the model is assumed to be comoving dust plus a positive cosmological constant. The model presents a critical point of saddle-center-center type in the finite region of phase space. This critical point engenders in the phase space dynamics the topology of stable and unstable four dimensional tubes $R \times S^3$, where $R$ is a saddle direction and $S^3$ is the manifold of unstable periodic orbits in the center-center sector. A general characteristic of the dynamical flow is an oscillatory mode about orbits of an invariant plane of the dynamics which contains the critical point and a Friedmann-Robertson-Walker (FRW) singularity. We show that a pair of tubes (one stable, one unstable) emerging from the neighborhood of the critical point towards the FRW singularity have homoclinic transversal crossings. The homoclinic intersection manifold has topology $R \times S^2$ and is constituted of homoclinic orbits which are bi-asymptotic to the $S^3$ center-center manifold. This is an invariant signature of chaos in the model, and produces chaotic sets in phase space. The model also presents an asymptotic DeSitter attractor at infinity and initial conditions sets are shown to have fractal basin boundaries connected to the escape into the DeSitter configuration (escape into inflation), characterizing the critical point as a chaotic scatterer.Comment: 11 pages, 6 ps figures. Accepted for publication in Phys. Rev.

Merging Galaxies in the SDSS EDR

We present a new catalog of merging galaxies obtained through an automated systematic search routine. The 1479 new pairs of merging galaxies were found in approximately 462 sq deg of the Sloan Digital Sky Survey Early Data Release (SDSS EDR; Stoughton et al. 2002) photometric data, and the pair catalog is complete for galaxies in the magnitude range 16.0 <= g* <= 20. The selection algorithm, implementing a variation on the original Karachentsev (1972) criteria, proved to be very efficient and fast. Merging galaxies were selected such that the inter-galaxy separations were less than the sum of the component galaxies' radii. We discuss the characteristics of the sample in terms of completeness, pair separation, and the Holmberg effect. We also present an online atlas of images for the SDSS EDR pairs obtained using the corrected frames from the SDSS EDR database. The atlas images also include the relevant data for each pair member. This catalog will be useful for conducting studies of the general characteristics of merging galaxies, their environments, and their component galaxies. The redshifts for a subset of the interacting and merging galaxies and the distribution of angular sizes for these systems indicate the SDSS provides a much deeper sample than almost any other wide-area catalog to date.Comment: 58 pages, which includes 15 figures and 6 tables. Figures 2, 8, 9, 10, 11, 13, and 14 are provided as JPEG files. For online atlas, see http://home.fnal.gov/~sallam/MergePair/ . Accepted for publication in A

Indução de embriogênese somática em calos das tangerineiras Cleópatra e Sunki Tropical.

A embriogênese somática em citros tem sido observada a partir de calos embriogênicos, cuja produção pode ocorrer a partir de nucelos, óvulos abortados, óvulos não desenvolvidos, dentre outros explantes. Esta técnica visa o desenvolvimento de aplicações biotecnológicas potenciais, tais como produção de sementes sintéticas, micropropagação e transformação genética, além de maximizar a regeneração de plantas

Regeneração e germinação de embriões somáticos oriundos de calos das tangerineiras Cleópatra e Sunki Tropical.

A embriogênese somática consiste no processo de regeneração de plantas a partir do cultivo in vitro onde células somáticas desenvolvem-se por meio de diferentes estádios embriogênicos, formando estruturas semelhantes a embriões zigóticos. A utilização de fitorreguladores tem se mostrado de importância fundamental para o estabelecimento da competência e da determinação dos tecidos em responder à indução da embriogênese somática in vitro