| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Wallberg, A E, et al.
(författare)
-
Recruitment of the SWI-SNF chromatin remodeling complex as a mechanism of gene activation by the glucocorticoid receptor tau 1 activation domain
- 2000
-
Ingår i: Molecular and Cellular Biology. - 0270-7306 .- 1098-5549. ; 20:6, s. 2004-2013
-
Tidskriftsartikel (refereegranskat)abstract
- The SWI-SNF complex has been shown to alter nucleosome conformation in an ATP-dependent manner, leading to increased accessibility of nucleosomal DNA to transcription factors. In this study, we show that the SWI-SNF complex can potentiate the activity of the glucocorticoid receptor (GR) through the N-terminal transactivation domain, tau 1, in both yeast and mammalian cells. GR-sl can directly interact with purified SWI-SNF complex, and mutations in tau 1 that affect the transactivation activity in vivo also directly affect tau 1 interaction with SWI-SNF. Furthermore, the SWI-SNF complex can stimulate tau 1-driven transcription from chromatin templates in vitro, Taken together, these results support a model in which the GR can directly recruit the SWI-SNF complex to target promoters during glucocorticoid-dependent gene activation. We also provide evidence that the SWI-SNF and SAGA complexes represent independent pathways of tau 1-mediated activation but play overlapping roles that are able to compensate for one another under some conditions.
|
|
| 7. |
- Deeming, Antony J, et al.
(författare)
-
Oxidative addition of silanes R3SiH to the unsaturated cluster [Os3(µ-H){µ3-Ph2PCH2PPh(C6H4)}(CO)8]: Evidence for reversible silane formation in the dynamic behaviour of [Os3(µ-H)(SiR3)(CO)9(µ-dppm)]
- 2004
-
Ingår i: Dalton Transactions. - 1477-9234. ; 2004:21, s. 3709-3714
-
Tidskriftsartikel (refereegranskat)abstract
- Oxidative addition of the silanes R3SiH (R3= Ph3, Et3, EtMe2) to the unsaturated cluster [Os3(µ-H){µ3-Ph2PCH2PPh(C6H4)}(CO)8] leads to the saturated clusters [Os3(µ-H)(SiR3)(CO)9(µ-dppm)](SiR3= SiPh31, SiEt32 and SiEtMe23) and the unsaturated clusters [Os3(µ-H)2(SiR3){µ3-Ph2PCH2PPh(C6H4)}(CO)7](SiR3= SiPh34, SiEt35 and SiEtMe26). Structures are based on spectroscopic evidence and a XRD structure of [Os3(µ-H)(SiPh3)(CO)9(µ-dppm)]1 in which all non-CO ligands are coordinated equatorially and the hydride and the silyl groups are mutually cis. From variable-temperature 1H NMR spectra of the SiEt3 compound 2, exchange of the P nuclei is clearly apparent. Simultaneous migrations of the SiEt3 group and of the hydride from one Os–Os edge to another generate a time-averaged mirror plane in the molecule. VT 1H NMR spectra of the somewhat less bulky compound [Os3(µ-H)(SiMe2Et)(CO)9(µ-dppm)]3 have been analysed. Two isomers 3a and 3b are observed with the hydride ligand located on different Os–Os edges. Synchronous migration of the hydride and SiMe2Et groups is faster than the observed interconversion of isomers which occurs by hydride migration alone. The synchronous motion of H and SiR3only occurs when these ligands are mutually cis as in the major isomer 3a and we propose that this process requires the formation of a transient silane complex of the type [Os3(2-HSiR3)(CO)9(µ-dppm)]. Turnstile rotation within an Os(CO)3(2-HSiR3) group leads to the observed exchange within the major isomer 3a without exchange with the minor isomer. This process is not observed for the minor isomer 3b because the hydride and the silyl group are mutually trans. Protonation to give [Os3(µ-H)2(SiR3)(CO)9(µ-dppm)]+ totally suppresses the dynamic behaviour because there are no edge vacancies.
|
|
| 8. |
|
|
| 9. |
- Hassan, A. E., et al.
(författare)
-
Computational issues in the determination of solute discharge moments and implications for comparison to analytical solutions
- 2001
-
Ingår i: Advances in Water Resources. - 0309-1708 .- 1872-9657. ; 24:6, s. 607-619
-
Tidskriftsartikel (refereegranskat)abstract
- Solute discharge moments (mean and variance) are computed using numerical modeling of flow and advective transport in two-dimensional heterogeneous aquifers and are compared to theoretical results, The solute discharge quantifies the temporal evolution of the total contaminant mass crossing a certain compliance boundary. In addition to analyzing the solute discharge moments within a classical absolute dispersion framework, we also analyze relative dispersion formulation, whereby plume meandering (deviation from mean flow path caused by velocity variations at scales larger than plume size) is removed. This study addresses some important issues related to the computation of solute discharge moments from random walk particle tracking experiments, and highlights some of the important differences between absolute and relative dispersion frameworks. Relative dispersion formulation produces maximum uncertainty that coincides with the peak mean discharge. Absolute dispersion, however, results in earlier arrival of the uncertainty peak as compared to the first moment peak. Simulations show that the standard deviation of solute discharge in a relative dispersion framework requires increasingly large temporal sampling windows to smooth out some of the large fluctuations in breakthrough curves associated with advective transport. Using smoothing techniques in particle tracking to distribute the particle mass over a volume rather than at a point significantly reduces the noise in the numerical simulations and removes the need to use large temporal windows. Same effect can be obtained by adding a local dispersion process to the particle tracking experiments used to model advective transport. The effect of the temporal sampling window bears some relevance and important consequences for evaluating risk-related parameters. The expected value of peak solute discharge and its standard deviation are very sensitive to this sampling window and so will be the risk distribution relying on such numerical models.
|
|
| 10. |
- Hassan, A. E., et al.
(författare)
-
Evaluation of analytical solute discharge moments using numerical modeling in absolute and relative dispersion frameworks
- 2002
-
Ingår i: Water resources research. - : American Geophysical Union (AGU). - 0043-1397 .- 1944-7973. ; 38:2
-
Tidskriftsartikel (refereegranskat)abstract
- Two-dimensional numerical simulations are used to validate the analytical solutions for the solute discharge moments. In addition to the analysis of classical absolute dispersion we also consider relative dispersion whereby plume meandering (deviation from mean flow path caused by velocity variations at scales larger than plume size) is removed. The numerical simulations are used within a Monte Carlo framework to assess the accuracy and robustness of the analytical predictions of the solute discharge moments (mean and variance). Results show that the analytical predictions deviate from the numerical simulations as the log conductivity variance increases. Deviation occurs for the mean as well as the variance of the solute discharge. The absolute dispersion formulation, however, shows better agreement with the numerical simulations than does the relative dispersion for strong heterogeneity and vice versa for small variability. The relative dispersion results, however, depend on the prediction of the ensemble mean of the plume arrival time, which differs between simulations and analytical solution. Using the first-order analytical estimate for this parameter leads to a much better agreement between the numerical and the analytical results for solute discharge moments in the relative dispersion case.
|
|
