991 resultados para 218


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although in the late 1990s there was much discussion as to whether the idea of information literacy was necessary or had longevity, global interest in the phenomenon has increased rather than diminished. In the midst of all this activity, what has happened to the way in which we interpret the idea of information literacy in the last decade or more? The label of information literacy has certainly become widely applied, especially to library based programs and remains more popular in formal learning environments.Ultimately information literacy is about peoples’ experience of using information wherever they happen to be. Information literacy is about people interacting, engaging, working with information in many contexts, either individually or in community. Emerging technologies may transform the kinds of information available and how it is engaged with. Nevertheless, we continue to need to understand the experience of information use in order to support people in their information environments. We continue to need to develop programs which reflect and enhance peoples’ experiences of using information to learn in ever widening and more complex settings (Bruce, 2008; Bruce & Hughes, 2010).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mycobacterium leprae recA harbors an in-frame insertion sequence that encodes an intein homing endonuclease (PI-MleI). Most inteins (intein endonucleases) possess two conserved LAGLIDADG (DOD) motifs at their ctive center. A common feature of LAGLIDADG-type homing endonucleases is that they recognize and cleave the same or very similar DNA sequences. However, PI-MleI is distinctive from other members of the family of LAGLIDADG-type HEases for its modular structure with functionally separable domains for DNA-binding and cleavage, each with distinct sequence preferences. Sequence alignment analyses of PI-MleI revealed three putative LAGLIDADG motifs; however, there is conflicting bioinformatics data in regard to their identity and specific location within the intein polypeptide. To resolve this conflict and to determine the active-site residues essential for DNA target site recognition and double-stranded DNA cleavage, we performed site-directed mutagenesis of presumptive catalytic residues in the LAGLIDADG motifs. Analysis of target DNA recognition and kinetic parameters of the wild-type PI-MleI and its variants disclosed that the two amino acid residues, Asp(122) (in Block C) and Asp(193) (in functional Block E), are crucial to the double-stranded DNA endonuclease activity, whereas Asp(218) (in pseudo-Block E) is not. However, despite the reduced catalytic activity, the PI-MleI variants, like the wild-type PI-MleI, generated a footprint of the same length around the insertion site. The D122T variant showed significantly reduced catalytic activity, and D122A and D193A mutations although failed to affect their DNA-binding affinities, but abolished the double-stranded DNA cleavage activity. On the other hand, D122C variant showed approximately twofold higher double-stranded DNA cleavage activity, compared with the wild-type PI-MleI. These results provide compelling evidence that Asp(122) and Asp(193) in DOD motif I and II, respectively, are bona fide active-site residues essential for DNA cleavage activity. The implications of these results are discussed in this report.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The significance of two interface arginine residues on the structural integrity of an obligatory dimeric enzyme thymidylate synthase (TS) from Lactobacillus casei was investigated by thermal and chemical denaturation. While the R178F mutant showed apparent stability to thermal denaturation by its decreased tendency to aggregate, the Tm of the R218K mutant was lowered by 5 degrees C. Equilibrium denaturation studies in guanidinium chloride (GdmCl) and urea indicate that in both the mutants, replacement of Arg residues results in more labile quaternary and tertiary interactions. Circular dichroism studies in aqueous buffer suggest that the protein interior in R218K may be less well-packed as compared to the wild type protein. The results emphasize that quaternary interactions may influence the stability of the tertiary fold of TS. The amino acid replacements also lead to notable alteration in the ability of the unfolding intermediate of TS to aggregate. The aggregated state of partially unfolded intermediate in the R178F mutant is stable over a narrower range of denaturant concentrations. In contrast, there is an exaggerated tendency on the part of R218K to aggregate in intermediate concentrations of the denaturant. The 3 A crystal structure of the R178F mutant reveals no major structural change as a consequence of amino acid substitution. The results may be rationalized in terms of mutational effects on both the folded and unfolded state of the protein. Site specific amino acid substitutions are useful in identifying specific regions of TS involved in association of non-native protein structures.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Mais da metade do substitutivo do Relator Bernardo Cabral já foi analisado. Na última reunião no Instituto Israel Pinheiro, dois temas foram amplamente discutidos: o Poder Judiciário e o fim dos "marajás" no serviço público. O Deputado Bernardo Cabral (PMDB-AM) afirma que ninguém mais ingressará no serviço público sem ser através de concurso público, que os "marajás" no serviço público serão extintos e que haverá critérios para o preenchimento de cargos de confiança. Em reunião da Comissão de Sistematização, constituintes criticam as reuniões no Instituto Israel Pinheiro. O Deputado José Genoíno (PT-SP) considera que o trabalho da Assembleia Nacional Constituinte (ANC) tem que ser feito dentro do Congresso Nacional. O Líder do Governo Carlos Santana declara que esse trabalho tem que vir para a Comissão de Sistematização. O Relator Bernardo Cabral (PMDB-AM) responde as criticas. O Presidente da ANC, Deputado Ulysses Guimarães (PMDB-SP) defende o Deputado Bernardo Cabral, dizendo que, por enquanto, o substitutivo é responsabilidade do Relator e pode ser elaborado em qualquer lugar. O Deputado Nelson Sabrá (PFL-RJ) que tomou posse na vaga do falecido Deputado Alair Ferreira (PFL-RJ), declara que é preciso condensar ainda mais os artigos da Constituição. Parlamentares do Norte, Nordeste e Centro-Oeste pedem ao Presidente da Assembleia Nacional Constituinte (ANC), Deputado Ulysses Guimarães apoio às emendas que favoreçam suas regiões. O Deputado Raimundo Bezerra (PMDB-CE) considera que a emenda mais importante é aquela que estabelece a renda a ser distribuída pela União para essas áreas. O Deputado José Dutra (PMDB-AM) afirma ser indispensável que os parlamentares marquem posição no sentido de garantir aos povos dessas regiões uma vida menos difícil do que a que têm hoje.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

2001

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present an analysis of the data from our Swedish-ESO Submillimetre Telescope molecular line survey in the 1.3 mm band of the N, M, and NW positions in the Sgr B2 molecular cloud. The line emissions from 42 molecular species, and some of their isotopomers, were analyzed assuming a single temperature and a homogeneous source. In cases where a source size much smaller than the antenna beam (23

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We have surveyed the frequency band 218.30-263.55 GHz toward the core positions N and M and the quiescent cloud position NW in the Sgr B2 molecular cloud using the Swedish-ESO Submillimetre Telescope. In total 1730, 660, and 110 lines were detected in N, M, and NW, respectively, and 42 different molecular species were identified. The number of unidentified lines are 337, 51, and eight. Toward the N source, spectral line emission constitutes 22% of the total detected flux in the observed band, and complex organic molecules are the main contributors. Toward M, 14% of the broadband flux is caused by lines, and SO2 is here the dominant source of emission. NW is relatively poor in spectral lines and continuum. In this paper we present the spectra together with tables of suggested line identifications.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). METHODS AND FINDINGS: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction)  = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio  = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio  = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. CONCLUSIONS: The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Se aborda de manera particular el análisis de las exenciones concedidas por el Estado mediante la Ley 218 de 1995, más conocida como la Ley Páez, tras la emergencia económica que sufrieron los Departamentos de Cauca y Huila. Se debaten los conceptos de gasto público y ahorro fiscal.