Search results for "TF"
showing 10 items of 1652 documents
TFIIH Operates through an Expanded Proximal Promoter To Fine-Tune c-myc Expression
2004
A continuous stream of activating and repressing signals is processed by the transcription complex paused at the promoter of the c-myc proto-oncogene. The general transcription factor IIH (TFIIH) is held at promoters prior to promoter escape and so is well situated to channel the input of activators and repressors to modulate c-myc expression. We have compared cells expressing only a mutated p89 (xeroderma pigmentosum complementation group B [XPB]), the largest TFIIH subunit, with the same cells functionally complemented with the wild-type protein (XPB/wt-p89). Here, we show structural, compositional, and functional differences in transcription complexes between XPB and XPB/wt-89 cells at t…
PEMBEKUAN SEMEN LELE DUMBO (Clarias Gariepinus BURCHELL 1822) SEBAGAI MODEL KRIOPRESERVASI SEMEN IKAN
2010
<p><em>Effect of four types of diluents</em><em>s</em><em> and four concentration of DMSO (5%, 10%, 15% and 20%) against the motility of African catfish sperm were evaluated after storage at freezing temperatures. </em><em>The steps in preparation the 16 treatments combination of the diluents</em><em> </em><em>are </em><em>preparation of diluents, mixing </em><em>diluents </em><em>with DMSO, packing </em><em>of semen </em><em>in</em><em>to</em><em> 0.3-ml straw, equilibration of </em><em>semen </em><em>at 4 °C for…
Chemical and dimensional evolution of cationic ions exchange resins in cement pastes
2013
Ion exchange resins (IERs) are widely used by the nuclear industry to decontaminate radioactive effluents. After use they are usually encapsulated in cementitious materials. However, the solidified waste forms can exhibit a strong expansion, possibly leading to cracking. Its origin is not well understood as well as the conditions when it occurs.In this work, the interactions between cationic resins in the Na+ or Ca2+ form and tricalcium silicate (C3S), Portland cement (CEM I) or Blastfurnace slag cement (CEM III/C) are investigated at an early age in order to gain a better understanding of the expansion process.The results show that during the hydration of a paste of C3S or CEM I containing…
Existence of metastable intermediate lysozyme conformation highlights the role of alcohols in altering protein stability.
2011
Alcohols have a manifold effect on the conformational and thermodynamic stability of native proteins. Here, we study the effect of moderate concentrations of trifluoroethanol (TFE) on the thermal stability of hen egg-white lysozyme (HEWL), by far-UV circular dichroism and by steady-state and time-resolved photoluminescence of intrinsic tryptophans. Our results highlight that TFE affects lysozyme stability by preferential solvation of the protein molecule. Furthermore, we discovered the existence at 20% TFE of an equilibrium partially folded state of lysozyme, intermediate between the native and the unfolded state. A three-state model is therefore used to interpolate the thermal denaturation…
Qualitative analysis on the driving force behind upcycling practices associated with mobile applications: Circular economy perspective
2022
Funding for open access charge: Universidad de Granada/CBUA
Wellfounded Trees and Dependent Polynomial Functors
2004
We set out to study the consequences of the assumption of types of wellfounded trees in dependent type theories. We do so by in- vestigating the categorical notion of wellfounded tree introduced in [16]. Our main result shows that wellfounded trees allow us to define initial algebras for a wide class of endofunctors on locally cartesian closed cat- egories.
Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw
2020
Significance Over many millennia, northern peatlands have accumulated large amounts of carbon and nitrogen, thus cooling the global climate. Over shorter timescales, peatland disturbances can trigger losses of peat and release of greenhouses gases. Despite their importance to the global climate, peatlands remain poorly mapped, and the vulnerability of permafrost peatlands to warming is uncertain. This study compiles over 7,000 field observations to present a data-driven map of northern peatlands and their carbon and nitrogen stocks. We use these maps to model the impact of permafrost thaw on peatlands and find that warming will likely shift the greenhouse gas balance of northern peatlands. …
Integration of Metal Organic Chemical Vapour Deposition and Wet Chemical Techniques to Obtain Highly Ordered Porous ZnO Nanoplatforms
2011
Large-area, highly ordered ZnO micropores-arrays consisting of ZnO nanotubes delimited by ZnO nanorods have been successfully fabricated and tested for protein sensing applications. ZnO seed layers have been deposited by Metal Organic Chemical Vapour Deposition and readily patterned by Colloidal Lithography to attain ZnO nanorods growth at selective sites by Chemical Bath Deposition. The used synthetic approach has been proven effective for the easy assembly of ZnO nanoplatforms into high-density arrays. Both patterned and unpatterned ZnO nanorods have been morphologically and compositionally characterised and, thus, tested for model studies of protein mobility at the interface. The pattern…
Going Public – Going Private: The Case of VC-Backed Firms
2012
We investigate the decisions of listed firms to go private once again. We start by revealing that while a significant number of firms which go public is VC-backed, an overproportional share of these VC-backed firms go private later on (they stay on the exchange for an average of 8.5 years). We interpret this very robust pattern such that IPOs of VC-backed firms are to a large extent a temporary rather than a permanent feature of the corporate governance of these firms.We investigate various potential hypotheses why VCs actually seem to be able to bring marginal firms to the exchange by relating the going-private decisions to various characteristics of the IPO market as well as to VC charact…
The Effect of Credit Rating Events on the Emerging CDS Market
2017
We document the cross-border spillover impact of S&P sovereign credit rating events on sovereign CDS using an extensive sample of emerging economies. First, we find on average a competition (imitation) effect of downgrades (upgrades) among emerging portfolios. Results confirms that non-event portfolios responds positively to credit deteriorations in terms of an improvement in sovereign credit risk. Second, the sovereign credit risk of non-event countries within the same portfolio benefit (suffer) from downgrades (upgrades). As expected, this implies a competition effect in terms of sovereign credit risk. Moreover, we find that downgrades are more likely to spill over into other emerging mar…