2,218 research outputs found
Two site contact of elongating transcripts to phage T7 RNA polymerase at C-terminal regions
No full texthttp://nar.oxfordjournals.org/cgi/content/abstract/29/3/e11A series of active elongation complexes of the phage T7 RNA polymerase were obtained through stepwise walking of the polymerase along an immobilized DNA template. Transcripts were radiolabeled at the 16th to 18th residues, and a photocross-linkable 4-thio-UMP was separately incorporated at the 22nd, 24th, 32nd, and 38th residues. Such complexes (up to 51 nucleotides) produced by the incorporation of one nucleotide at a time were isolated and individually subjected to long wave UV cross-linking. Only when the cross-linker was positioned at the 3'-end (-1) of the elongating RNA and 8 nucleotides upstream (-9), was the RNA substantially cross-linked to the polymerase, regardless of how far it was from the 5'-end of the transcripts. Linkage of the 3'-end residue was mapped to the Thr(636)-Met(666) region, which contains nucleotide-binding sites. The -9 residue was cross-linked to the Ala(724)-Met(750) region rather than to the N-terminal region. These two contacts were maintained throughout the elongation complexes and reveal a route of nascent RNA through the T7 RNA polymerase in elongation complexes
Sectoral allocation by gender of Latin American workers over the liberalization period of the 1990s
No full textThe recent restructuring of Latin American economies has renewed interest in the effects of trade liberalization, on labor markets, and on the gender division of labor. The author does not attempt to establish casuality between economic reforms, and the types of jobs that men and women hold. Instead, she provides a detailed description of the trends in male, and female formal, and informal sector participation during the economic reform period in Argentina, Brazil, and Costa Rica. The author first compares the gender composition of the formal, informal wage, and self-employment sectors in a year before reforms (1988 for Argentina, 1989 for Brazil, and Costa Rica), and a year after reforms implementation (1997 for Argentina, 1995 for Brazil and Costa Rica). Although women continued to be more likely than men to work in the informal wage sector, there is no trend of"masculinization"or"feminization"of the informal sector, or any other. Instead, in Argentina men have overtaken women as the most prevalent workers in the informal wage sector, while in Brazil, the opposite has occurred (as men move into self-employment). In Costa Rica there have been no statistical, observable changes. The author then considers the distribution across sectors within each gender group, to identify whether men, and women are more likely to select different sectors in the post-reform period relative to the pre-reform period. Among both men, and women in all three countries (except Brazilian men), workers have become more likely to hold informal wage jobs, and less likely to hold formal sector jobs. Trends in human capital accumulation explain these changes for both men, and women, while changes in gender roles, primarily in homecare and marriage, do not seem to have an effect.Health Monitoring&Evaluation,Labor Policies,Population&Development,Public Health Promotion,Environmental Economics&Policies,Health Monitoring&Evaluation,Environmental Economics&Policies,Population&Development,Banks&Banking Reform,Work&Working Conditions
Time-resolved photoluminescence study of InGaAs/GaAs quantum wells on (111)B GaAs under magnetic fields
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Initial serum glucose level as a prognostic factor in the first acute myocardial infarction
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HH-420 thermostatic water bath box.
No full textThe new thermal insulating shotcrete is of great significance for the management of thermal damage in deep mines, and its own strength has a greater impact on the roadway insulation and safe production, so it is very necessary to study the shear strength of the new thermal insulating shotcrete under the influence of the deep hot and humid environment and the stress of mining. For the heat-insulating shotcrete, firstly, we carried out the concrete variable angle shear test under different loading rates, which concluded that the shear rate and peak shear stress showed a trend of increasing and then decreasing; as the angle increases, the different rates have a greater impact on the peak shear stress of the specimen. Secondly, the concrete variable angle shear test was carried out under the temperature and humidity cycle, which revealed that the shear strength of thermal insulated shotcrete increased firstly and then decreased with the increase of temperature at the same number of cycles. Finally, the empirical equations between the cohesive force c, the angle of internal friction ϕ and the number of warm and wet cycles n and the temperature of warm and wet cycles T are fitted with the MATLAB software respectively, and the research results provide technical references for the management of geothermal temperature in deep well projects.</div
The transcriptional activator Gli2 modulates T-cell receptor signalling through attenuation of AP-1 and NFκ-B activity.
No full textDifferent tissues contain diverse and dynamic cellular niches, providing distinct signals to tissue-resident or migratory, infiltrating immune cells. Hedgehog (Hh) proteins are secreted inter-cellular signalling molecules, which are essential during development and are important in cancer, post-natal tissue homeostasis and repair. Hh signalling, via the Hh-responsive transcription factor Gli2, also has multiple roles in T-lymphocyte development and differentiation. Here we investigate the function of Gli2 in T-cell signalling and activation. Gene transcription driven by the Gli2 transcriptional activator (Gli2A) attenuated T-cell activation and proliferation following T-cell receptor (TCR) stimulation. Expression of Gli2A in T-cells altered gene expression profiles, impaired the TCR-induced calcium flux and nuclear expression of NFAT, suppressed upregulation of molecules essential for activation, and attenuated signalling pathways upstream of AP-1 and NFκB, leading to reduced activation of these important transcription factors. Inhibition of physiological Hh-dependent transcription increased NFκB activity on TCR ligation. These data have importance for understanding molecular mechanisms of immunomodulation, particularly in tissues where Hh proteins or other Gli-activating ligands such as TGFβ are upregulated, including during inflammation, tissue damage and repair, or in tumour microenvironments
Expression profiling identifies novel Hh/Gli-regulated genes in developing zebrafish embryos
No full textThe Hedgehog (Hh) signaling pathway plays critical instructional roles during embryonic development. Misregulation of Hh/Gli signaling is a
major causative factor in human congenital disorders and in a variety of cancers. The zebrafish is a powerful genetic model for the study of Hh
signaling during embryogenesis, as a large number of mutants that affect different components of the Hh/Gli signaling system have been
identified. By performing global profiling of gene expression in different Hh/Gli gain- and loss-of-function scenarios we identified known
(e.g., ptc1 and nkx2.2a) and novel Hh-regulated genes that are differentially expressed in embryos with altered Hh/Gli signaling function. By
uncovering changes in tissue-specific gene expression, we revealed new embryological processes that are influenced by Hh signaling. We thus
provide a comprehensive survey of Hh/Gli-regulated genes during embryogenesis and we identify new Hh-regulated genes that may be targets of
misregulation during tumorigenesis.This work was supported by Mecesup UCH0306 Scholarship
and Development Traveling Fellowship (L.A.M.), NIH
NS03994 and HD044929 (R.O.K.), ICM P06-039F (M.A. and
V.P.), Fondecyt Grants 1070867 (M.A.) and 1070248 (V.P.),
and the Intramural Program of the National Human Genome
Research Institute (S.M.B.)
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