Modeling the spectrum of gravitational waves in the primordial Universe

Recent observations from type Ia Supernovae and from cosmic microwave background (CMB) anisotropies have revealed that most of the matter of the Universe interacts in a repulsive manner, composing the so-called dark energy constituent of the Universe. The analysis of cosmic gravitational waves (GW) represents, besides the CMB temperature and polarization anisotropies, an additional approach in the determination of parameters that may constrain the dark energy models and their consistence. In recent work, a generalized Chaplygin gas model was considered in a flat universe and the corresponding spectrum of gravitational waves was obtained. The present work adds a massless gas component to that model and the new spectrum is compared to the previous one. The Chaplygin gas is also used to simulate a $\Lambda$-CDM model by means of a particular combination of parameters so that the Chaplygin gas and the $\Lambda$-CDM models can be easily distinguished in the theoretical scenarios here established. The lack of direct observational data is partialy solved when the signature of the GW on the CMB spectra is determined.Comment: Proc. of the Conference on Magnetic Fields in the Universe: from laboratories and stars to primordial structures, AIP(NY), eds. E. M. de Gouveia Dal Pino, G. Lugones & A. Lazarian (2005), in press. (8 pages, 11 figures

Magnetic Field Effects on the Head Structure of Protostellar Jets

We present the results of 3-D SPMHD numerical simulations of supermagnetosonic, overdense, radiatively cooling jets. Two initial magnetic configurations are considered: (i) a helical and (ii) a longitudinal field. We find that magnetic fields have important effects on the dynamics and structure of radiative cooling jets, especially at the head. The presence of a helical field suppresses the formation of the clumpy structure which is found to develop at the head of purely hydrodynamical jets. On the other hand, a cooling jet embedded in a longitudinal magnetic field retains clumpy morphology at its head. This fragmented structure resembles the knotty pattern commonly observed in HH objects behind the bow shocks of HH jets. This suggests that a strong (equipartition) helical magnetic field configuration is ruled out at the jet head. Therefore, if strong magnetic fields are present, they are probably predominantly longitudinal in those regions. In both magnetic configurations, we find that the confining pressure of the cocoon is able to excite short-wavelength MHD K-H pinch modes that drive low-amplitude internal shocks along the beam. These shocks are not strong however, and it likely that they could only play a secondary role in the formation of the bright knots observed in HH jets.Comment: 14 pages, 2 Gif figures, uses aasms4.sty. Also available on the web page http://www.iagusp.usp.br/preprints/preprint.html. To appear in The Astrophysical Journal Letter

Presence of Enterobacteriaceae and Clostridiaceae in thte soil according to the use of biofertilizers of feces from goats and sheep.

The use of biofertilizers appears as an alternative to the use of chemical fertilizers and use of residues generated by animal production. However, the presence of possible pathogens belonging to the families Enterobacteriaceae and Clostridiaceae in biofertilizers from feces can lead to sanitary and ecological problems

Dinâmica da matéria orgânica sob sistemas de manejo no solo no município de Paragominas-PA.

Uma das características marcantes do plantio direto é o aumento do teor de matéria orgânica na camada superficial do solo com o decorrer do tempo de sua implantação. O presente trabalho teve como objetivo avaliar a dinâmica da matéria orgânica sob sistemas de manejo em Paragominas-PA. O estudo foi executado na fazenda Juparanã, com delineamento de blocos ao acaso com quatro tratamentos, o T1 (plantio direto: soja/milho em rotação), T2 (plantio direto: milho/soja, em rotação), T3 (plantio convencional: soja/milho) e T4 (plantio convencional: monocultivo de soja) com três repetições. Foram coletadas amostras deformadas, na camadas: 0-5, 5-10, 10-20, 20-30 e 30-50 cm. A MO, foi analisada no Laboratório de Solos da Embrapa Amazônia Oriental e as médias foram submetidas à análise de variância. Conclui-se que o plantio direto proporcionou ao longo do tempo aumento nos teores de matéria orgânica no solo, quando comparado ao de preparo convencional

Eletroforese de ácidos nucléicos.

bitstream/item/224366/1/7.-ELETROFORESE-DE-ACIDOS-NUCLEICOS.pd

Extração de DNA.

Regras de segurança em laboratórios; Extração de DNA; Extração de RNA; Quantificação em espectrofotômetro; Reação em cadeia da polimerase (PCR); Enzimas de restrição; Eletroforese de ácidos nucléicos; Seqüenciamento; Síntese de DNA complementar (CDNA

Turbulence and the formation of filaments, loops and shock fronts in NGC 1275 in the Perseus Galaxy Cluster

NGC1275, the central galaxy in the Perseus cluster, is the host of gigantic hot bipolar bubbles inflated by AGN jets observed in the radio as Perseus A. It presents a spectacular $H{\alpha}$-emitting nebulosity surrounding NGC1275, with loops and filaments of gas extending to over 50 kpc. The origin of the filaments is still unknown, but probably correlates with the mechanism responsible for the giant buoyant bubbles. We present 2.5 and 3-dimensional MHD simulations of the central region of the cluster in which turbulent energy, possibly triggered by star formation and supernovae (SNe) explosions is introduced. The simulations reveal that the turbulence injected by massive stars could be responsible for the nearly isotropic distribution of filaments and loops that drag magnetic fields upward as indicated by recent observations. Weak shell-like shock fronts propagating into the ICM with velocities of 100-500 km/s are found, also resembling the observations. The isotropic outflow momentum of the turbulence slows the infall of the intracluster medium, thus limiting further starburst activity in NGC1275. As the turbulence is subsonic over most of the simulated volume, the turbulent kinetic energy is not efficiently converted into heat and additional heating is required to suppress the cooling flow at the core of the cluster. Simulations combining the MHD turbulence with the AGN outflow can reproduce the temperature radial profile observed around NGC1275. While the AGN mechanism is the main heating source, the supernovae are crucial to isotropize the energy distribution.Comment: accepted by ApJ Letter

Estudo de associação entre microssatélites localizados no cromossomo ovino 3 e peso ao nascimento de ovinos pertencentes a três grupos genéticos.

O objetivo do presente trabalho foi verificar a associação entre três marcadores microssatélites localizados no cromossomo ovino 3 (OAR3) e o peso ao nascimento de ovinos pertencentes a três grupos genéticos (Santa Inês x Santa Inês, Dorper x Santa Inês e Suffolk x Santa Inês). Foi verificada associação entre o marcador BL4 e a característica em dois grupos genéticos (Santa Inês x Santa Inês e Dorper x Santa Inês). O alelo BL4_169 apresentou efeito de diminuição de 0,59 kg (P=0,0188) no peso ao nascimento nos animais Santa Inês x Santa Inês e o alelo BL4_155 apresentou efeito de diminuição de 0,57 kg (P=0,0447) nos animais Dorper x Santa Inês