Search results for "Mechanism"
showing 10 items of 1835 documents
A Public Barrier Tracker to Support the Web Accessibility Directive
2018
In this paper we propose the Public Barrier Tracker (PBT) – a comprehensive solution that supports both filing and handling of user feedback on web accessibility. We give an overview of some existing approaches for gathering user feedback on accessibility barriers and outline the PBT functionality. The PBT can also offer further support for the implementation of the WAD: The collected data could be useful for monitoring and reporting as well as the enforcement mechanism.
Mechanism of Antibacterial Activity via Morphology Change of α-AgVO3: Theoretical and Experimental Insights
2017
The electronic configuration, morphology, optical features, and antibacterial activity of metastable α-AgVO3 crystals have been discussed by a conciliation and association of the results acquired by experimental procedures and first-principles calculations. The α-AgVO3 powders were synthesized using a coprecipitation method at 10, 20, and 30 °C. By using a Wulff construction for all relevant low-index surfaces [(100), (010), (001), (110), (011), (101), and (111)], the fine-tuning of the desired morphologies can be achieved by controlling the values of the surface energies, thereby lending a microscopic understanding to the experimental results. The as-synthesized α-AgVO3 crystals display a …
EBIT diagnostics using X-ray spectra of highly ionized Ne
2003
We have carried out a detailed analysis of highly ionized neon spectra collected at the NIST EBIT using an NTD germanium X-ray microcalorimeter developed at the Harvard-Smithsonian Center for Astrophysics [Nucl. Instr. and Meth. A 444 (2000) 156]. Our attention was focused especially on the Ne IX He-like triplet to check electron density diagnostics through the intercombination/forbidden line ratio. We have investigated possible effects of the ion dynamics on the plasma emission line intensities, looking at the dependence of the count-rate and the charge state distribution on the electron beam energy and current. The temperature and spatial distribution of the neon ions, and hence the overl…
3D simulations of wind-jet interaction in massive X-ray binaries
2010
High-mass microquasars may produce jets that will strongly interact with surrounding stellar winds on binary system spatial scales. We study the dynamics of the collision between a mildly relativistic hydrodynamical jet of supersonic nature and the wind of an OB star. We performed numerical 3D simulations of jets that cross the stellar wind with the code Ratpenat. The jet head generates a strong shock in the wind, and strong recollimation shocks occur due to the initial overpressure of the jet with its environment. These shocks can accelerate particles up to TeV energies and produce gamma-rays. The recollimation shock also strengthens jet asymmetric Kelvin-Helmholtz instabilities produced i…
Heterogeneous zirconocene catalyst on magnesium support MgCl2(THF)2 modified by AlEt2Cl for ethylene polymerisation
2005
Abstract The heterogeneous bis(cyclopentadienyl)zirconium(IV) dichloride catalyst of the composition MgCl2(THF)/(AlEt2Cl)0.34/(Cp2ZrCl2)0.01 as determined by FTIR, XRD, and AAS analyses was synthesised and, after activation by MAO, applied for ethylene polymerisation. The catalyst turned out to be stable and more active than those magnesium supported catalysts already known from the literature. The polyethylene produced has a relatively high molecular weight (Mw > 200,000 g/mol), a narrow and monomodal molecular weight distribution (MWD = 2.4), a bulk density of about 180 g/dm3, and monomodal particle size distribution. Application of a ternary Al(i-Bu)3/MAO/B(C6F5)3 activator decreased the…
GABAA-receptor Subtypes: Clinical Efficacy and Selectivity of Benzodiazepine Site Ligands
1997
The main inhibitory neurotransmitter receptor of the brain, the gamma-aminobutyric acid type A receptor (GABA[A]), mediates the actions of several classes of clinically important drugs, such as benzodiazepines, barbiturates and general anaesthetics. This review summarizes the current knowledge on how classical benzodiazepines and novel nonbenzodiazepine compounds act on the benzodiazepine site of GABA(A) receptors and on their clinical pharmacology related to anxiolytic, sedative, hypnotic and cognitive effects or side-effects. Partial agonism, receptor subtype selectivity and novel binding sites are discussed as possible strategies to develop new drugs with fewer adverse effects than are s…
Sex-ratio of Skylark Alauda arvensis broods in relation to timing of breeding.
2006
4 pages; International audience; Capsule Earlier broods tend to be more male biased than later broods.
Sex-specific transgenerational effects of early developmental conditions in a passerine.
2007
Most studies dealing with the trade-off between offspring number and quality have overlooked the long-term consequences for the progeny. High investment in offspring number usually results in an increased competition among nest mates. The deterioration of the early developmental conditions, due to this increased competition, can impair individual quality over the long term, and subsequently affect survival and lifetime fecundity. Moreover, the consequences of the allocation rule to offspring number vs. quality can extend across generations and give raise to grandparental effects. These transgenerational trade-offs have been explored rarely. In the present study, we manipulated the breeding …
Unravelling [3+2] Cycloaddition Reactions through the Molecular Electron Density Theory
2018
Después de la primera clasificación de las reacciones 32CA en reacciones de tipo zw y pr, establecidas en el año 2014, la estructura y reactividad de los TACs más importantes utilizados en las reacciones 32CA ha sido completamente caracterizado en base a la MEDT propuesta recientemente. Entre la gran cantidad de trabajo desarrollado a lo largo de la presente tesis doctoral, se han seleccionado y discutido ocho publicaciones representativas, que permitieron caracterizar dos nuevos tipos de reactividad y consolidar la reactividad original de tipo zw. Así, dependiendo de las cuatro estructuras electrónicas diferentes de los TACs, es decir, pseudodiradical, pseudoradical, carbenoide y zwitterió…
Mechanisms of beneficial legume-microbe interactions
2013
Understanding mechanisms underlying high nutrients use efficiency and carbon allocation in a context of legumes-microbe interactions at the root level (mycorrhiza and nodules) is critical for sound management of croplands taking care of ecosystem services rendered by beneficial microbes. Indeed, availability, uptake and exchange of nutrients in biotrophic interactions will drive plant growth and modulate biomass allocation, that are central to plant yield, a major outcome, in the context of high biomass production. Transport processes across the polarised membrane interfaces are of major importance in the functioning of the established symbiosis as the relation is based on a 'fair-trade' be…