Biblioteca da Embrapa Rondônia: estudo das necessidades informacionais de usuários reais e potenciais.

Este trabalho apresenta uma pesquisa, de caráter quantitativo e qualitativo, com usuários reais e potenciais da Biblioteca da Embrapa Rondônia, na perspectiva de verificar as demandas informacionais destes usuários.bitstream/CPAF-RO-2010/14551/1/129-bibliotecaembraparondonia.pd

Serviço de referência online: a experiência da Embrapa Rondônia.

CBBD

Receptividade estigmatica em Eucalyptus dunnii.

Devido à sua importância para os estudos de biologia reprodutiva da espécie e visando oferecer subsídios para melhorar a eficiência da polinização controlada, estudou-se a receptividade do estigma de E. dunnii Maiden, em um banco clonal, com 8 anos de idade, no município de Colombo, PR. Seis ramos em diferentes posições da copa de dois clones foram amostrados para a seleção de 20 botões florais, no estágio adequado à emasculação. Seis polinizações foram feitas, com intervalo de dois dias entre elas, no período de 10 dias, utilizando-se uma mistura de pólen de 3 clones diferentes do mesmo banco. As avaliações foram feitas mensalmente, na forma de contagem de cápsulas (frutos), até 180 dias após a emasculação Após esse período, os frutos foram coletados e as sementes extraídas. A quantidade de sementes produzidas por cápsula e o número total de cápsulas resultante das polinizações controladas variam entre clones. Para a maximização da eficiência da polinização controlada de E. dunnii, recomenda-se que esta seja feita ao redor do sexto dia após a antese

Dimensional crossover and incipient quantum size effects in superconducting niobium nanofilms

Superconducting and normal state properties of sputtered Niobium nanofilms have been systematically investigated, as a function of film thickness in a d=9-90 nm range, on different substrates. The width of the superconducting-to-normal transition for all films remained in few tens of mK, thus remarkably narrow, confirming their high quality. We found that the superconducting critical current density exhibits a pronounced maximum, three times larger than its bulk value, for film thickness around 25 nm, marking the 3D-to-2D crossover. The extracted magnetic penetration depth shows a sizeable enhancement for the thinnest films, aside the usual demagnetization effects. Additional amplification effects of the superconducting properties have been obtained in the case of sapphire substrates or squeezing the lateral size of the nanofilms. For thickness close to 20 nm we also measured a doubled perpendicular critical magnetic field compared to its saturation value for d>33 nm, indicating shortening of the correlation length and the formation of small Cooper pairs in the condensate. Our data analysis evidences an exciting interplay between quantum-size and proximity effects together with strong-coupling effects and importance of disorder in the thinnest films, locating the ones with optimally enhanced critical properties close to the BCS-BEC crossover regime

Programa de melhoramento de pínus na Embrapa Florestas.

bitstream/item/61074/1/Documento-233.pd

Avaliação de basidiomicetos do gênero ganoderma para degradação de lignina e celulose.

EVINCI. Resumo

A genetic analysis of the porin gene encoding a voltage-dependent anion channel protein in Drosophila melanogaster

The voltage-dependent anion channel (VDAC, also known as porin) is an abundant protein in the outer mitochondrial membrane that forms transmembrane channels permeable to solutes. While in mammals at least three different porin genes have been found, only one VDAC-encoding gene, porin, has been described so far in Drosophila melanogaster. It produces transcripts with alternative 5′ untranslated sequences. Here we report the identification of two PlacW insertions in the porin gene among a set of P-element insertions that have been mapped to the 32B3-4 region on the second chromosome. Homozygotes, as well as trans-heterozygotes for these insertions, lack VDAC, and die during the late pupal stage. Function can be restored by precise excision of the P transposon, while most deletions in the porin locus, produced by imprecise excisions, display the recessive lethal effect of the original mutant alleles. However, one of the deletions was found to be a hypomorphic male-sterile allele producing low levels of the VDAC protein, indicating that the product of the porin gene is also essential for male fertility. Analysis of the new mutant alleles also showed that the untranslated exon 1B of the porin gene is not required for VDAC synthesis. In the course of our investigation, we found that immediately adjacent to the porin gene are three more genes encoding proteins that share homology with the VDAC protein. The possible evolutionary and functional relationships of the porin-like genes at 32B3-4 are discussed

Location of the dicyclohexylcarbodiimide-reactive glutamate residue in the bovine heart mitochondrial porin.

The mitochondrial porin or VDAC (Voltage-Dependent Anion Channel), the pore-forming structure responsible for the high permeability of the outer mitochondrial membrane, was found to be one of only three mitochondrial proteins bound by [14C]dicyclohexylcarbodiimide (DCCD) at low dosages (1.5 nmol/mg of mitochondrial porin) (De Pinto, V., Tommasino, M., Benz, R., and Palmieri, F. (1985) Biochim. Biophys. Acta 813, 230-242). Treatment of intact mitochondria with DCCD results in the inhibition of their ability to binding hexokinase (Nakashima, R. A., Mangan, P. S., Colombini, M., and Pedersen, P. L. (1986) Biochemistry 25, 1015-1021). In the present study, mitochondrial porin was purified from [14C]DCCD-labeled mitochondria. The purified labeled porin was treated with the cleavage reagent CNBr and with the endoproteases trypsin and V8 from Staphylococcus aureus and blotted to polyvinylidene difluoride membrane. The transferred peptides were detected with Coomassie Blue dye, excised, and sequenced. The sequences of several labeled and unlabeled peptides were obtained and then overlapped. The region containing the [14C]DCCD radioactivity was limited to 50 amino acid residues and completely sequenced. Covalently incorporated [14C]DCCD was exclusively released at the position corresponding to glutamate 72. The DCCD-reactive residue is located in the 4th of 16 predicted transmembrane amphipathic beta-strands. When the sequence surrounding the DCCD site was compared to those surrounding the DCCD-reactive residue of other membrane proteins, no homology was apparent