Development of a reverse genetics system enabling the rescue of recombinant avian influenza virus A/Turkey/England/50-92/91 (H5N1)

We previously described the use of an established reverse genetics system for the generation of recombinant human influenza A viruses from cloned cDNAs. Here, we have assembled a set of plasmids to allow recovery of the avian H5N1 influenza virus A/Turkey/England/50-92/91 entirely from cDNA. This system enables us to introduce mutations or truncations into the cDNAs to create mutant viruses altered specifically in a chosen gene. These mutant viruses can then be used in future pathogenesis studies in chickens and in studies to understand the host range restrictions of avian influenza viruses in humans.

Time-resolved gas-phase kinetic and quantum chemical studies of reactions of silylene with chlorine-containing species. 1. HCl

Time-resolved kinetic studies of the reaction of silylene, SiH2, generated by laser flash photolysis of phenylsilane, have been carried out to obtain rate constants for its bimolecular reaction with HCL The reaction was studied in the gas phase at 10 Torr total pressure in SF6 bath gas, at five temperatures in the range of 296-611 K. The second-order rate constants fitted the Arrhenius equation: log(k/cm(3) molecule(-1) s(-1)) = (-11.51 +/- 0.06) + (1.92 +/- 0.47 kJ mol(-1))/RTIn10 Experiments at other pressures showed that these rate constants were unaffected by pressure in the range of 10-100 Torr, but showed small decreases in value of no more than 20% ( +/- 10%) at I Toff, at both the highest and lowest temperatures. The data are consistent with formation of an initial weakly bound donor-acceptor complex, which reacts by two parallel pathways. The first is by chlorine-to-silicon H-shift to make vibrationally excited chlorosilane, SiH3Cl*, which yields HSiCl by H-2 elimination from silicon. In the second pathway, the complex proceeds via H-2 elimination (4-center process) to make chlorosilylene, HSiCl, directly. This interpretation is supported by ab initio quantum calculations carried out at the G3 level which reveal the direct H-2 elimination route for the first time. RRKM modeling predicts the approximate magnitude of the pressure effect but is unable to determine the proportions of each pathway. The experimental data agree with the only previous measurements at room temperature. Comparisons with other reactions of SiH2 are also drawn.

The old metal-poor open cluster ESO 92-SC05: accreted from a dwarf galaxy ?

The study of old open clusters outside the solar circle can bring constraints on formation scenarios of the outer disc. In particular, accretion of dwarf galaxies has been proposed as a likely mechanism in the area. We use BVI photometry for determining fundamental parameters of the faint open cluster ESO 92-SC05. Colour-magnitude diagrams are compared with Padova isochrones, in order to derive age, reddening and distance. We derive a reddening E(B - V) = 0.17, and an old age of similar to 6.0 Gyr. It is one of the rare open clusters known to be older than 5 Gyr. A metallicity of Z similar to 0.004 or [M/H] similar to -0.7 is found. The rather low metallicity suggests that this cluster might be the result of an accretion episode of a dwarf galaxy.

Blocking the maturation of OncomiRNAs using pri-miRNA-17∼92 aptamer in retinoblastoma

The miR-17∼92. or oncomiR-1, cluster encodes oncogenic microRNAs (miRNAs), and it also promotes retinoblastoma (RB) tumor formation. Antagomir and miRNA mimics based approaches are widely tried against oncogenic and tumor suppressive miRNAs. Other methods for targeting cancer related miRNAs are still under development. In the current study, we focused on the pri-miRNA-17∼92 aptamer (pri-apt), which can potentially replace the mix of five antagomirs by one aptamer that function to abrogate the maturation of miR-17, miR-18a, and miR-19b (P<0.05) for targeting RB. We used RB cell lines WERI-Rb1 and Y79 as an in vitro model. Cellular changes upon transfecting the pri-apt led to S-phase arrest in WERI-Rb1 cells and onset of apoptosis in both Y79 and WERI-Rb1 cell lines. There was increased cytotoxicity as measured by lactate dehydrogenase activity in pri-apt treated Y79 cells (P<0.05), and significant inhibition of cell proliferation was observed in both of the cell lines. Thus we showed the antiproliferative property of pri-apt in RB cell lines, which can be readily modified by developing appropriate vectors for the delivery of the aptamer specifically to cancer cells.

Violação dos princípios constitucionais expressos e seu controle pela lei de improbidade administrativa (Artigo 11, Lei 8.429/92)

A presente monografia tem como finalidade explicar e ressaltar a importância dos princípios constitucionais-administrativos disciplinados pelo artigo 37 da Constituição Federal, que são verdadeiras “cláusulas pétreas”, fazendo com que qualquer norma jurídica que os contrarie, seja submetida a controle jurídico pelos órgãos jurisdicionais. Tem como principal foco a identificação e análise dos atos de improbidade administrativa à luz do princípio da moralidade administrativa e seu controle pela Lei 8.429/92, demonstrando a possível incidência do agente público desonesto, ímprobo, em atos de improbidade administrativa que atentam contra os princípios da Administração Pública (artigo 11, Lei 8.429/92). Frisou-se também que a Lei 8.429/92 constitui marco na administração pública e no combate a corrupção, ante a preocupação cada vez maior com a impunidade dos agentes públicos e com o objetivo de defender a honestidade no exercício da função pública, uma vez que previu que a violação aos princípios administrativos incidiria em improbidade administrativa. Por fim, observou-se que a Lei 8.429/92 trouxe em seu corpo, severas sanções aplicáveis aos agentes públicos que incidem em ato de improbidade por violação aos princípios da Administração Pública (artigo 11), cominando-lhe sanções políticas, civis e administrativas (artigo 12, III) e definindo os sujeitos ativos e passivos desse ato de improbidade.

Public debt sustainability and endogenous seignorage in Brazil: time-series evidence from 1947-92

Using national accounts data for the revenue-GDP and expenditure GDP ratios from 1947 to 1992, we examine two central issues in public finance. First, was the path of public debt sustainable during this period? Second, if debt is sustainable, how has the government historically balanced the budget after hocks to either revenues or expenditures? The results show that (i) public deficit is stationary (bounded asymptotic variance), with the budget in Brazil being balanced almost entirely through changes in taxes, regardless of the cause of the initial imbalance. Expenditures are weakly exogenous, but tax revenues are not;(ii) a rational Brazilian consumer can have a behavior consistent with Ricardian Equivalence (iii) seignorage revenues are critical to restore intertemporal budget equilibrium, since, when we exclude them from total revenues, debt is not sustainable in econometric tests.

Public debt sustainability and endogenous seigniorage in Brazil: time-series evidence from 1947-92: revised version

Using national accounts data for the revenue-GDP and expenditureGDP ratios from 1947 to 1992, we examine three central issues in public finance. First, was the path of public debt sustainable during this period? Second, if debt is sustainable, how has the government historically balanced the budget after shocks to either revenues or expenditures? Third, are expenditures exogenous? The results show that (i) public deficit is stationary (bounded asymptotic variance), with the budget in Brazil being balanced almost entirely through changes in taxes, regardless of the cause of the initial imbalance. Expenditures are weakly exogenous, but tax revenues are not; (ii) the behavior of a rational Brazilian consumer may be consistent with Ricardian Equivalence; (iii) seigniorage revenues are critical to restore intertemporal budget equilibrium, since, when we exclude them from total revenues, debt is not sustainable in econometric tests.

Growth of the hermit crab Clibanarius vittatus (Bosc, 1802) (Crustacea, Anomura, Diogenidae) at São Vicente, São Paulo, Brazil

O presente estudo teve como objetivo analisar o crescimento de machos e fêmeas do ermitão Clibanarius vittatus (Bosc, 1802), da região de São Vicente, São Paulo, Brasil. Foram realizadas coletas mensais de maio/2001 a abril/2003, na Praia dos Pescadores em São Vicente. Os 2.501 animais capturados foram identificados, determinados quanto ao sexo e mensurados quanto ao seu comprimento de escudo cefalotorácico (CEC). Para o estudo sazonal do crescimento, a população foi dividida em classes de tamanho de 5mm de (CEC), e analisada pelo método de Bertalanffy, com o auxílio do software Fisat II. Foram obtidos 703 indivíduos machos e 1.798 fêmeas, com média de tamanho de 8.94±1.80 e 6.61±1.13mm, respectivamente. Constatou-se um padrão de crescimento sazonal, com machos atingindo um tamanho assintótico (14.92mm) superior ao das fêmeas (13.85mm), além de iniciarem o processo de crescimento aproximadamente cinco meses antes destas. Desta forma, é provável que este seja um padrão que auxilia na diminuição da disputa intra-específica por conchas, uma vez que os machos atingiram maior tamanho e estariam disponibilizando conchas menores para as fêmeas.

Digestibilidade aparente da energia e nutrientes do farelo de canola pela tilápia do Nilo (Oreochromis niloticus)

Este estudo foi realizado para determinar a energia digestível e a digestibilidade aparente de nutrientes do farelo de canola pela tilápia do Nilo (Oreochromis niloticus). O óxido de crômio (0,1%) foi utilizado como indicador inerte em dieta semi-purificada, com coleta de fezes pelo sistema Guelph. Os peixes foram alimentados até saciedade aparente. O farelo de canola apresentou valores de energia e nutrientes digestíveis de: 77,84; 71,99; 86,92; 88,19; 67,16 e 29,86% para a matéria seca, energia, proteína, lipídios, cálcio e fósforo, respectivamente, correspondendo a 2969,98 (kcal/kg); 69,97; 32,6; 1,2; 0,41 e 0,28%, de energia digestível, matéria seca, proteína e lipídios digestíveis e cálcio e fósforo disponíveis, respectivamente. Os resultados obtidos neste trabalho evidenciam que a tilápia do Nilo pode utilizar eficientemente o farelo de canola.