Bacillus Thuringiensis: diversidade gênica em isolados Lepidoptera-específicos.

O presente trabalho teve como objetivo caracterizar geneticamente 1.073 isolados de Bacillus thuringiensis, de três coleções brasileiras, provenientes da UNESP, Jaboticabal, ESALQ - Piracicaba e da EMBRAPA. Sete Lagoas, analisando os tipos de genes cryl apresentados pelos isolados. Para isso, foram elaborados oligonucleotídeos iniciadores a partir de 16 regiões conservadas e 4 regiôes não conservadas das seqüências de cada uma das 16 subclasses do gene cryl. Essas seqüências foram amplificadas por PCR e a presença de amplicons para cada subclasse foi calculada em porcentagem por gene e por coleção. Nessa análise, 55,7'?u dos isolados apresentaram amplificação para o gene cryl, e as subclasses cryl Aa, cryl Al>, cryl Ac. cryl Ad, cryl Ac, cryl Af, cryl 1 Ag, l e cryl 1 Bj; cryl Ca e cryl Fa estão presentes em ai ta proporção de isolados, variando de 43,4 % a 54, 9'?u. Verificou-se que existe uma distribuição das subclasses dentro do banco de isolados de B. thuringiensis em estudo, com maior porcentagem de isolados portadores dos genes cryl Al> (42,12%) e com menor porcentagem de representantes da subclasse cryl D/1 (0,6%). A variabilidade gênica, nas coleções analisadas, destaca as coleções de Jaboticabal e Piracicaba como fontes de isolados promissores para uso em programas de Controle Biológico de pragas da ordem Lepidoptera. A coleção de Sete Lagoas, na qual as freqüências das subclasses estudadas foram reIativamente baixas (a baixo de 20%), destaca somente o gene cryl A/1, presente em 38,5% dos isolados desta coleção

The name of a model species: the case of Orchestia cavimana (Crustacea: Amhipoda: Talitridae)

The species commonly known as Orchestia cavimana belonging to the Talitridae family (Amphipoda) has been used as crustacean model species. Here, we point out that this talitrid amphipod species is related to species in the genus Orchestia but now falls under what is described as Cryptorchestia garbinii, which is a different species from the nominal species Cryptorchestia cavimana endemic to the Island of Cyprus. It is therefore important that future basic research and applied studies involving this model organism refer to it as C. garbinii. Its old assignment O. cavimana, or even C. cavimana, as still reported in the National Center for Biotechnology Information (NCBI) GenBank and in recent papers, may lead to confusion

<i>Cryptorchestia ruffoi</i> sp. n. from the island of Rhodes (Greece), revealed by morphological and phylogenetic analysis (Crustacea, Amphipoda, Talitridae)

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EU3+-O2- associates luminescence in Ba2SiO4

Results on the luminescence properties of Eu3+ in Ba2SiO4 sites and the presence of Eu3+-O2- associates are reported. The Ba2SiO4:Eu3+ emission spectra showed two groups of transitions that might be assigned to the D-5(0) --> F-7(0) one. In each group at least two lines were observed. This is possibly related to the different emission centers, attributed to Eu3+ occupying the Ba2+ sites, and to Eu3+-O2- associates in interstices. Excitation spectra presented two CT bands at 270 and 340 nm related to each emission center

The effect of Eu3+ concentration on the Y2O3 host lattice obtained from citrate precursors

This work presents a thermal decomposition study of the precursor resin prepared from the citrate precursor along with structural features and optical properties materials composed by Y2O3 and Eu3+ containing Y2O3 in 0.5, 3, 5 and 7 mol%. The microcrystallite sizes were estimated from the Scherrer equation. The structural and optical properties revealed that the addition of 5 mol% of Eu3+ to the Y2O3 matrix gave rise to the highest relative emission intensity which was evidenced by the luminescence intensity. The lifetime of the 0.5 mol% Eu3+-doped sample suggested two different symmetry sites for Eu3+ ions because two different lifetime values were acquired for this sample, while for phosphors doped with 3 or 5 mol% of Eu3+ ions only one similar lifetime was observed. When the concentration of Eu3+ is 0.5 and 3 mol%, the luminescence intensity is weak due to the low probability of the O2--Eu3+ charge transfer transition. on the other hand, when the concentration of the Eu3+ ions is 7 mol%, a quenching effect is evidenced. (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

MnO4(3-) NIR luminescence in Ba2SiO4

Ba2SiO4: MnO43- luminescence is reported and compared to similar host lattices based on PO43-, VO43- and AsO43-, where Mn5+ substitutes for p(5+),V5+ Or AS(5+). The observed energy position of MnO43- 1E state in SiO44- is in accordance with interelectronic repulsion caused by Mn5+-O bond length. At 77 K the E-1 splitting is 119 cm(-1), which is in agreement with 1.8 degrees, the average deviation of O-M-O angles from the regular tetrahedron. These values are adjusted to Ca point symmetry. The vibronic-structure spectra evidenced a progression with a frequency assigned to the nu(2)(E) bending mode of MnO43-

Spectroscopic characteristics of Er3+ in the two crystallographic sites of Gd2SiO5

Gd2SiO5 is among the interesting and suitable hosts for Er3+ which find extensive applications in the infrared, visible and ultraviolet spectral regions. In order to investigate its potentialities, a prior study of the spectroscopic behaviour of Er3+ substituting for Gd3+ ions in the two crystallographic sites of the host was performed. Absorption, excitation, site-selective emission and time-resolved spectroscopies were employed in the visible spectral region to study transitions between excited 4S3/2 and ground 4I15/2 states. These levels multiplets were attributed to each site separately, and their corresponding 4S3/2 lifetimes (1.8 ± 0.1 μs for site 1 and 3.2 ± 0.1 μs for site 2) were determined