560 research outputs found
A Comparison of Prospective Memory and Executive Process in Patients with Subcortical Illness
Алгоритм проведення попередньої дегазації методом гравітаційного знещільнення вуглепородного масиву
Приводится алгоритм проведения предварительной дегазации при применении нового способа гравитационной разгрузки на угольных месторождениях Донбасса и Львовско-Волынского бассейнов. Среди главных эффектов, которые будут получены при внедрении способа – обеспечение безопасности работ на шахтах и промышленная добыча метана.The algorithm of realization of pre-degassing with using new way of gravitational unloading on coal fields of Donbas and Lviv-Volyn basins is given in this article. Guaranteeing of safety works in mines and industrial methane-mining are between main effects which will be got on conditions of application of this method
E1A functions as a coactivator of retinoic acid-dependent retinoic acid receptor-beta 2 promoter activation
The retinoic acid (RA) receptor (RAR) beta 2 promoter is strongly activated by RA in embryonal carcinoma (EC) cells. We examined this activation in the P19 EC-derived END-2 cell line and in E1A-expressing counterparts and found strong RA-dependent RAR beta 2 promoter activation in the E1A-expressing cells, which was not observed in the parental cell line, indicating a possible role for E1A in RAR beta 2 activation. In transient transfection assays, E1A functioned as a coactivator of RA-dependent RAR beta 2 promoter activation and, moreover, was able to restore this activation in cells lacking RAR beta 2 activation. By deletion analysis, two regions in the RAR beta 2 promoter were identified that mediate the stimulatory effect of E1A: the RA response element and TATA box-containing region and a more up-stream region between -180 and -63, in which a cAMP response element-related motif was identified as a target element for E1A. In addition, determination of endogenous E1A-like activity by measuring E2A promoter activity in transient transfection assays in EC and differentiated cells revealed a correlation between RA-dependent RAR beta 2 promoter activation and the presence of this activity, suggesting an important role for the cellular equivalent of E1A in regulation of the RAR beta 2 promoter
Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species
Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress) on plants changing emissions of biogenic volatile organic compounds (BVOCs). As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the <i>de novo</i> emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the <i>de novo</i> emissions were constitutive or induced by biotic stress. <br><br> In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed <i>de novo</i> emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of <i>de novo</i> emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease. <br><br> Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do not consider stress impacts
Cellular Applications of DNP Solid-State NMR: State of the Art and a Look to the Future
Sensitivity enhanced dynamic nuclear polarization solid-state NMR is emerging as a powerful technique for probing the structural properties of conformationally homogenous and heterogenous biomolecular species irrespective of size at atomic resolution within their native environments. Herein we detail advancements that have made acquiring such data, specifically within the confines of intact bacterial and eukaryotic cell a reality and further discuss the type of structural information that can presently be garnered by the technique's exploitation. Subsequently, we discuss bottlenecks that have thus far curbed cellular DNP-ssNMR's broader adoption namely due a lack of sensitivity and spectral resolution. We also explore possible solutions ranging from utilization of new pulse sequences, design of better performing polarizing agents, and application of additional biochemical/ cell biological methodologies
Veiligheid en beveiliging van offshore Windturbineparken Integrale veiligheidsstudie
Dit rapport geeft de bevindingen weer van een integrale studie naar de veiligheidsaspecten rond de realisatie van (meerdere) offshore windturbineparken op het Nederlandse deel van de Noordzee. Het onderzoek is geïnitieerd in het kader van het onderzoeksprogramma We@Sea. Offshore windturbineparken beïnvloeden de veiligheid op zee b.v. doordat ze ruimte innemen die voorheen vrij gebruikt konden worden door scheepvaart en visserij. Door verdringing treedt verdichting op van het scheepvaartverkeer rondom het windturbinepark en het ingenomen gebied wordt onbereikbaar voor vissers. Daarnaast zijn de windturbines objecten waarmee schepen in aanvaring kunnen komen b.v. wanneer zij op drift raken. De gevaren in deze zijn wederzijds, zowel de windturbines kunnen schade oplopen door zo’n gebeurtenis, maar ook de schepen kunnen beschadigd raken. In het geval dat het schip een milieugevaarlijke lading b.v. chemicaliën of olie vervoert, dreigt er tevens gevaar voor het milieu
Analysis of the XPA and ssDNA-binding surfaces on the central domain of human ERCC1 reveals evidence for subfunctionalization.
Human ERCC1/XPF is a structure-specific endonuclease involved in multiple DNA repair pathways. We present the solution structure of the non-catalytic ERCC1 central domain. Although this domain shows structural homology with the catalytically active XPF nuclease domain, functional investigation reveals a completely distinct function for the ERCC1 central domain by performing interactions with both XPA and single-stranded DNA. These interactions are non-competitive and can occur simultaneously through distinct interaction surfaces. Interestingly, the XPA binding by ERCC1 and the catalytic function of XPF are dependent on a structurally homologous region of the two proteins. Although these regions are strictly conserved in each protein family, amino acid composition and surface characteristics are distinct. We discuss the possibility that after XPF gene duplication, the redundant ERCC1 central domain acquired novel functions, thereby increasing the fidelity of eukaryotic DNA repair
Genetic switching by the Lac repressor is based on two-state Monod–Wyman–Changeux allostery
High-resolution NMR spectroscopy enabled us to characterize allosteric transitions between various functional states of the dimeric Escherichia coli Lac repressor. In the absence of ligands, the dimer exists in a dynamic equilibrium between DNA-bound and inducer-bound conformations. Binding of either effector shifts this equilibrium toward either bound state. Analysis of the ternary complex between repressor, operator DNA, and inducer shows how adding the inducer results in allosteric changes that disrupt the interdomain contacts between the inducer binding and DNA binding domains and how this in turn leads to destabilization of the hinge helices and release of the Lac repressor from the operator. Based on our data, the allosteric mechanism of the induction process is in full agreement with the well-known Monod–Wyman–Changeux model
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