Seletividade de Metarhizium anisopliae à Telenomus podisi (Hymenoptera: Scelionidae).

Telenomus podisi e Metarhizium anisopliae são agentes de controle biológico que ocorrem ou podem ser utilizados conjuntamente. Entretanto, estudos de compatibilidade entre parasitoides e fungos entomopatogênicos são escassos. O objetivo deste trabalho foi avaliar a seletividade do fungo M. anisopliae a adultos do parasitoide de ovos T. podisi. Suspensões de M. anisopliae (1,0×109 conídios/ml) foram pulverizadas sobre placas de vidro em Torre de Potter e secas à temperatura ambiente, formando uma película. Como testemunha foi utilizada água destilada estéril + Tween 80 (0,01%). As placas de vidro pulverizadas foram utilizadas na construção de gaiolas de exposição (IOBC) e em seu interior foram liberados adultos de T. podisi com 24 h de idade. As gaiolas foram mantidas em condições controladas de temperatura, umidade e fotoperiodo (25±1º C, 80% UR, 14 h) e os parasitóides foram alimentados com mel. Cartelas contendo ovos de Euschistus heros foram oferecidas às fêmeas de T. podisi 24 h, 48 h, 72 h e 144 h após a pulverização e, sendo posteriormente, acondicionadas em sacos plásticos para avaliar a porcentagem de parasitismo e viabilidade dos parasitoides. Os resultados obtidos indicam que mesmo com as aplicações de M. anisopliae, o parasitismo e a viabilidade foram superiores a 70%, mostrando que o fungo é seletivo aos adultos de T. podisi, sendo classificado como inócuo (classe 1), de acordo com a IOBC, e portanto, ambos os agentes de controle biológico podem ser utilizados no Manejo Integrado de Pragas.SICONBIOL 2011

Efeito de Metarhizium anisopliae ASH. sobre Telenomus podisi (Hymenoptera: scelionidae).

Os agentes de controle biológico Metarhizium anisopliae e Telenomus podisi são empregados no controle de populações de pragas. Porém na literatura são citados casos de interferência entre agentes de controle. Para serem utilizados concomitantemente, a compatibilidade entre o fungo entomopatogênico e o parasitoide deve ser elucidada. O objetivo deste trabalho foi avaliar os possíveis efeitos do fungo M. anisopliae na eficiência do parasitoide de ovos T. podisi. Os bioensaios foram conduzidos em duas etapas, utilizando ovos não parasitados e ovos parasitados. Na primeira etapa, ovos de Euschistus heros esterilizados aderidos a cartelas (1×2 cm), receberam aplicações de 1,5 ml de suspensão de M. anisopliae (1,0×1010 conídios/ml), em torre de Potter, sendo posteriormente expostos ao parasitismo. Na segunda etapa, suspensões de (1,0×109 conídios/ml) foram pulverizados sobre ovos parasitados. A testemunha recebeu água destilada estéril + Tween 80 (0,01%) em ambos os ensaios. Após as pulverizações, as cartelas foram inseridas em gaiolas de exposição padronizadas pela (IOBC), mantidas em condições controladas de temperatura, umidade e fotoperiodo (25±1º C, 80%, 14:10). Os parasitoides foram alimentados com mel. Para avaliar a porcentagem de parasitismo, emergência e viabilidade dos parasitóides, as cartelas de ovos contendo os parasitoides foram acondicionadas em sacos plásticos, posteriormente observadas em lupa estereoscópica para quantificação e calculo dos parâmetros estudados, Os resultados obtidos indicam que M. anisopliae não afeta o parasitismo de T. podisi, porém a emergência do parasitoide pode ser reduzida quando o fungo é aplicado sobre ovos previamente parasitados. Possivelmente, houve alguma atividade dos fungos sobre os ovos de E. heros que impediram a emergência de T. podisi e fatores físicos e bioquímicos podem estar envolvidos durante a infecção e penetração pelo córion. Entretanto, a redução da viabilidade do parasitismo quando o fungo foi aplicado em ovos parasitados foi percentualmente pequena. Por tanto, M. anisopliae é inócuo e seletivo a T. podisi, e ambos podem ser utilizados no manejo de pragas, preferencialmente quando as aplicações do fungo e liberações do parasitoide sejam realizadas em momentos diferentes para conseguir maior eficiência.SICONBIOL 2011

Role Of Oxygen Vacancies In The Magnetic And Dielectric Properties Of The High-dielectric-constant System Cacu3 Ti4 O12: An Electron-spin Resonance Study

We report experiments of electron spin resonance (ESR) of Cu2+ in polycrystalline samples of CaCu3 Ti4 O12 post-annealed in different atmospheres. After being synthesized by solid state reaction, pellets of CaCu3 Ti4 O12 were annealed for 24 h at 1000°C under air, Ar or O2. Our temperature dependent ESR data revealed for all samples nearly temperature independent g value (2.15(1)) and linewidth for T TN ≈25 K. However, the values of ESR linewidth are strongly affected by the oxygen content in the sample. For instance, argon post-annealed samples show a much larger linewidth than the O2 or air post-annealed samples. We attribute this broadening to an increase of the dipolar homogeneous broadening of the Cu2+ ESR lines due to the presence of oxygen vacancies which induce an S=1 2 spin inside the TiO6 octahedra. Correlation between a systematic dependence of the ESR linewidth on the oxygen content and the high dielectric constant of these materials is addressed. Also, ESR, magnetic susceptibility, and specific heat data for a single crystal of CaCu3 Ti4 O12 and for polycrystals of CdCu3 Ti4 O12 are reported. © 2006 The American Physical Society.7322Subramanian, M.A., Li, D., Duan, N., Reisner, B., Sleight, A.W., (2000) J. Solid State Chem., 151, p. 323. , JSSCBI 0022-4596 10.1006/jssc.2000.8703Ramirez, A.P., Subramanian, M.A., Gardel, M., Blumberg, G., Li, D., Vogt, T., Shapiro, S.M., (2000) Solid State Commun., 151, p. 217. , SSCOA4 0038-1098Homes, C.C., Vogt, T., Shapiro, S.M., Wakimoto, S., Ramirez, A.P., (2001) Science, 293, p. 673. , SCIEAS 0036-8075 10.1126/science.292.5517.673Lunkenheimer, P., Bobnar, V., Pronin, A.V., Ritus, A.I., Volkov, A.A., Loidl, A., (2002) Phys. Rev. B, 66, p. 052105. , PRBMDO 0163-1829 10.1103/PhysRevB.66.052105Homes, C.C., Vogt, T., Shapiro, S.M., Wakimoto, S., Subramanian, M.A., Ramirez, A.P., (2003) Phys. Rev. B, 67, p. 092106. , PRBMDO 0163-1829 10.1103/PhysRevB.67.092106Sinclair, D.C., Admas, T.B., Morrison, F.D., West, A.R., (2002) Appl. Phys. Lett., 80, p. 2153. , APPLAB 0003-6951 10.1063/1.1463211Giulloto, E., Mozzati, M.C., Azzoni, C.B., Massarotti, V., Bini, M., (2004) Ferroelectrics, 298, p. 61. , FEROA8 0015-0193Mozzati, M.C., Azzoni, C.B., Capsoni, D., Bini, M., Massarotti, V., (2003) J. Phys.: Condens. Matter, 15, p. 7365. , JCOMEL 0953-8984 10.1088/0953-8984/15/43/018Subramanian, M.A., Sleight, A.W., (2002) Solid State Sci., 4, p. 347. , SSSCFJ 1293-2558 10.1016/S1293-2558(01)01262-6Fang, L., Shen, M., Cao, W., (2004) J. Appl. Phys., 95, p. 6483. , JAPIAU 0021-8979 10.1063/1.1728308Koitzsch, A., Blumberg, G., Gozar, A., Dennis, B., Ramirez, A.P., Trebst, S., Wakimoto, S., (2002) Phys. Rev. B, 65, p. 052406. , PRBMDO 0163-1829 10.1103/PhysRevB.65.052406Bosman, A.J., Van Daal, H.J., (1970) Adv. Phys., 19, p. 1. , ADPHAH 0001-8732 10.1080/00018737000101071Lenjer, S., Schirmer, O.F., Hesse, H., Kool, T.W., (2002) Phys. Rev. B, 66, p. 165106. , PRBMDO 0163-1829 10.1103/PhysRevB.66.165106Bednorz, J.G., Mller, K.A., (1988) Rev. Mod. Phys., 60, p. 585. , RMPHAT 0034-6861 10.1103/RevModPhys.60.585Salamon, M.B., Jaime, M., (2001) Rev. Mod. Phys., 73, p. 583. , RMPHAT 0034-6861 10.1103/RevModPhys.73.583Scharfschwerdt, R., Mazur, A., Schirmer, O.F., Hesse, H., Mendricks, S., (1996) Phys. Rev. B, 54, p. 15284. , PRBMDO 0163-1829 10.1103/PhysRevB.54.15284Laguta, V.V., Slipenyuk, A.M., Bykov, I.P., Glinchuck, M.D., Maglione, M., Michau, D., Rosa, J., Jastrabik, L., (2005) Appl. Phys. Lett., 87, p. 022903. , APPLAB 0003-6951 10.1063/1.1954900Cohn, J.L., Peterca, M., Neumeier, J.J., (2005) J. Appl. Phys., 97, p. 034102. , JAPIAU 0021-8979 10.1063/1.1834976Abragam, A., Bleaney, B., (1670) Electron Paramagnetic Resonance of Transition Ions, , Clarendon, OxfordPoole, C.P., Farach, H.A., (1971) Relaxation in Magnetic Resonance, , Academic, New YorkVan Vleck, J.H., (1948) Phys. Rev., 74, p. 1168. , PHRVAO 0031-899X 10.1103/PhysRev.74.1168Anderson, P.W., Weiss, P.R., (1953) Rev. Mod. Phys., 25, p. 269. , RMPHAT 0034-6861 10.1103/RevModPhys.25.269Wu, L., Zhu, Y., Park, S., Shapiro, S., Shirane, G., Tafto, J., (1953) Rev. Mod. Phys., 25, p. 269. , RMPHAT 0034-6861 10.1103/RevModPhys.25.26

Scalar field in the Bianchi I: Non commutative classical and Quantum Cosmology

Using the ADM formalism in the minisuperspace, we obtain the commutative and noncommutative exact classical solutions and exact wave function to the Wheeler-DeWitt equation with an arbitrary factor ordering, for the anisotropic Bianchi type I cosmological model, coupled to a scalar field, cosmological term and barotropic perfect fluid. We introduce noncommutative scale factors, considering that all minisuperspace variables $\rm q^i$ do not commute, so the symplectic structure was modified. In the classical regime, it is shown that the anisotropic parameter $\rm \beta_{\pm nc}$ and the field $\phi$, for some value in the $\lambda_{eff}$ cosmological term and noncommutative $\theta$ parameter, present a dynamical isotropization up to a critical cosmic time $t_{c}$; after this time, the effects of isotropization in the noncommutative minisuperspace seems to disappear. In the quantum regimen, the probability density presents a new structure that corresponds to the value of the noncommutativity parameter.Comment: 17 pages, 6 figures, Acepted in IJT

Crystal Structure And Physical Properties Of Gd3co 4sn13 Intermetallic Antiferromagnet

We have synthesized single crystalline samples of Gd3 Co4 Sn13 intermetallic compound using a Sn-flux method. This compound crystallizes with a cubic Yb3 Co4 Sn13 -type structure, space group Pm-3n, which has 40 atoms per unit cell. Measurements of the magnetic susceptibility, heat capacity, electrical resistivity, and electron spin resonance (ESR) revealed that Gd3 Co4 Sn13 is a metallic Curie-Weiss paramagnet at high temperature and presents an antiferromagnetic ordering below TN =14.5 K. In the paramagnetic state, a single Gd3+ ESR line with a nearly temperature independent g∼2.005 (2) is observed, and its linewidth follows a Korringa-like behavior as a function of temperature. From the Korringa rate (ΔHΔT∼4 OeK) and g -shift (Δg∼0.012) obtained from the ESR experiments combined with the magnetic susceptibility and specific heat data for Gd3 Co4 Sn13, we have extracted the exchange parameters between the Gd3+ local moments and the conduction-electrons (c-e) in this compound. This exchange parameter Jfs ≈10 meV was found to be c-e wave-vector independent and the electronic structure of Gd3 Co4 Sn13 has a single band character. © 2006 American Institute of Physics.998Remeika, J.P., (1980) Solid State Commun., 34, p. 923Remeika, J.P., (1982) Solid State Commun., 42, p. 97Sato, H., (1993) Physica B, 188, p. 630Hundley, M.F., (2002) Phys. Rev. B, 65, p. 024401Israel, C., (2005) Physica B, 359-361, p. 251Cornelius, A., Physica BPagliuso, P.G., (2001) Phys. Rev. B, 63, p. 054426Granado, E., (2004) Phys. Rev. B, 69, p. 144411Davidov, D., Maki, K., Orbach, R., Rettori, C., Chock, E.P., (1973) Solid State Commun., 12, p. 621Feher, G., Kip, A.F., (1955) Phys. Rev., 98, p. 337. , 0031-899X 10.1103/PhysRev.98.337Dyson, F.J., (1955) Phys. Rev., 98, p. 349Yosida, K., (1957) Phys. Rev., 106, p. 893Korringa, J., (1950) Physica (Amsterdam), 16, p. 601Rettori, C., Kim, H.M., Chock, E.P., Davidov, D., (1974) Phys. Rev. B, 10, p. 1826Abragam, A., Bleaney, B., (1970) EPR of Transition Ions, , Clarendon, OxfordMoriya, T., (1963) J. Phys. Soc. Jpn., 18, p. 516Narath, A., (1967) Phys. Rev., 163, p. 232Pagliuso, P.G., (1999) Phys. Rev. B, 60, p. 13515Bittar, E.M.

Magnetic structure and enhanced T-N of the rare-earth intermetallic compound TbRhIn5: Experiments and mean-field model

In this work the physical properties of the intermetallic compound TbRhIn5 were investigated by means of temperature-dependent magnetic susceptibility, electrical resistivity, heat-capacity, and resonant x-ray magnetic diffraction experiments. TbRhIn5 is an intermetallic compound that orders antiferromagnetically at T-N=45.5 K, the highest ordering temperature among the existing RRhIn5 (1-1-5, R=rare earth) materials, which in contrast to what is expected from a de Gennes scaling along the RRhIn5 series. The x-ray resonant diffraction data have allowed us to solve the magnetic structure of TbRhIn5. Below T-N, we found a commensurate antiferromagnetic structure with a propagation vector (1/2,0,1/2) and the Tb moments oriented along the c axis. Strong (over two orders of magnitude) dipolar enhancements of the magnetic Bragg peaks were observed at both Tb absorption edges L-II and L-III, indicating a fairly high polarization of the Tb 5d levels. Using a mean-field model including an isotropic first-neighbor exchange interaction (J(R-R)) and the tetragonal crystalline electrical field (CEF), we evaluate the influence of the CEF effects in the physical properties of TbRhIn5. The results reported here seem to corroborate a general trend of CEF-driven effects on T-N along the RRhIn5 series.742

Magnetic Structure And Enhanced Tn Of The Rare-earth Intermetallic Compound Tbrh In5: Experiments And Mean-field Model

In this work the physical properties of the intermetallic compound TbRh In5 were investigated by means of temperature-dependent magnetic susceptibility, electrical resistivity, heat-capacity, and resonant x-ray magnetic diffraction experiments. TbRh In5 is an intermetallic compound that orders antiferromagnetically at TN =45.5 K, the highest ordering temperature among the existing RRh In5 (1-1-5, R=rare earth) materials, which in contrast to what is expected from a de Gennes scaling along the RRh In5 series. The x-ray resonant diffraction data have allowed us to solve the magnetic structure of TbRh In5. Below TN, we found a commensurate antiferromagnetic structure with a propagation vector (12,0,12) and the Tb moments oriented along the c axis. Strong (over two orders of magnitude) dipolar enhancements of the magnetic Bragg peaks were observed at both Tb absorption edges LII and LIII, indicating a fairly high polarization of the Tb 5d levels. 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Synthesis and evaluation of AlgNa-g-poly(QCL-co-HEMA) hydrogels as platform for chondrocyte proliferation and controlled release of betamethasone

Hydrogels obtained from combining different polymers are an interesting strategy for developing controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using a different concentration of the components. The hydrogels were characterized by Fourier transform-infrared spectroscopy, scanning electron microscopy, and a swelling degree. Betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at a different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner for up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay showed that almost all hydrogels are cytocompatibles and an increase of proliferation in both cell types after one week of incubation was observed by the Live/Dead(R) assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics, and biocompatibility.Oncologic Imagin