Search results for "CEO"
showing 10 items of 398 documents
Synthesis of high-surface area CeO2 through silica xerogel template: influence of cerium salt precursor”;
2010
Abstract Ceria nanosized oxides with high surface area were synthesized by means of a templating approach, using a porous silica xerogel with surface area as high as 718 m2/g. After impregnation of the silica template with the cerium salt solution and further calcination at 600 °C, the final ceria oxide was recovered by dissolving the silica framework in NaOH solution. The effect of cerium counteranion, nitrate or chloride, on the textural and reduction properties of the ceria oxide was examined. Characterizations by BET and pore size distribution, XRD, TPR and SEM/EDX techniques were performed. The silica xerogel templated approach resulted in the preparation of ceria with surface area of …
Analogues of cytotoxic squamocin using reliable reactions: new insights into the reactivity and role of the α,β-unsaturated lactone of the annonaceou…
2006
Abstract A small library of squamocin analogues has been prepared and screened biologically (cytotoxicity, inhibition of mitochondrial complex I and complex III). To centre diversity on a crucial part of the molecule (i.e., the α,β-unsaturated lactone), an original and reliable lactone opening reaction has been discovered and exploited among other efficient reactions.
Reduction of the frequency of herbaceous roots as an effect of soil compaction induced by heavy grazing in rangelands of SW Spain
2017
Rangelands in SW Spain constitute the most extensive ranching system on the Iberian Peninsula. During the last few decades, a significant increase in livestock numbers, along with a progressive substitution of cattle for sheep, have led to land degradation processes such as the reduction of grass cover and increased soil compaction in heavily grazed areas. Nevertheless, a better understanding of how soil compaction affects grass production is still needed. In this study, some of the effects of soil compaction due to heavy grazing are analysed, mainly the reduction of the frequency of herbaceous roots and its relationships with bulk density and soil penetration resistance. The study was carr…
Hafnium-neodymium isotope evidence for enhanced weathering and tectonic-climate interactions during the Late Cretaceous
2022
<p>Over million-year timescale the carbon cycle evolution is driven by mantle CO<sub>2</sub> degassing (source) and by continental weathering that drawdowns atmospheric CO<sub>2</sub> through silicate weathering reactions (sink). Based on a novel geochemical proxy of chemical weathering intensity (i.e. using measurements of Hf and Nd isotope ratios in clay-size fractions of sediments) and clay mineralogy, we discuss the links between tectonic, continental weathering and climate evolution during the late Cretaceous. That period records the very first step of the last greenhouse to icehouse transition and is concomitant to …
Deregulated Splicing Is a Major Mechanism of RNA-Induced Toxicity in Huntington's Disease.
2019
Huntington's disease (HD) is caused by an expanded CAG repeat in the huntingtin (HTT) gene, translating into an elongated polyglutamine stretch. In addition to the neurotoxic mutant HTT protein, the mutant CAG repeat RNA can exert toxic functions by trapping RNA-binding proteins. While few examples of proteins that aberrantly bind to mutant HTT RNA and execute abnormal function in conjunction with the CAG repeat RNA have been described, an unbiased approach to identify the interactome of mutant HTT RNA is missing. Here, we describe the analysis of proteins that preferentially bind mutant HTT RNA using a mass spectrometry approach. We show that (I) the majority of proteins captured by mutant…
Integration of CSR into CEOs’ compensation: effects on social and financial performance of French listed firms
2023
Based on the stakeholder model of corporate governance, this research analyzes the relationship between the integration of corporate social responsibility (CSR) into CEO compensation and corporate social and financial performance, in firms listed on France’s SBF 120 stock market between 2015 and 2019. The results of panel data regressions show that indexing CEO compensation on CSR criteria only influence corporate social performance Moreover, social performance has a positive impact on financial performance and a mediating effect between the integration of CSR criteria into CEO compensation and financial performance.
Dynamic Role of Gold d-Orbitals during CO Oxidation under Aerobic Conditions
2022
High-energy-resolution fluorescence detection-X-ray absorption near-edge structure (HERFD-XANES) at the Au L3 edge was used to study gold catalysts supported on ceria in order to unravel the role of gold 5d orbital modifications during the activation of molecular oxygen. The variations in the HERFD-XANES resonance peak, which are directly correlated with the d-band occupancy, were monitored in situ during the redox process of the CO oxidation at room temperature under both aerobic and anaerobic conditions. Interestingly, upon the oxidation treatment and also during the aerobic CO oxidation treatment, the gold d-band fluctuates around an average value, proving that the gold clusters are part…
Dzeltenās dzegužkurpītes Cypripedium calceolus L. demogrāfisko parametru ietekmējošie faktori Ķemeru Nacionālajā parkā
2017
Orhidejas, kā piemēram, dzeltenā dzegužkurpīte Cypripedium calceolus, ir viena no apdraudētākajām augu grupām pasaulē, jo tās ir šauri specializējušās un ļoti jutīgas pret izmaiņām biotopā. Līdz ar to, šo augu pētījumi mūsdienās ir arvien aktuālāki. Ķemeru Nacionālā parka trijās atradnēs 2016. gadā no maija līdz oktobrim tika ievākti dati, lai realizētu veiktā pētījuma mērķi – noskaidrot apgaismojuma un veģetācijas seguma ietekmi uz Cypripedium calceolus demogrāfiskajiem parametriem. Dati ievākti, izmantojot transekšu/parauglaukumu metodi, kur apļveida parauglaukumos (1,5 m rādiuss) noteica paaugā un pamežā esošās sugas un skaitu dažādās augstuma klasēs, kā arī vaskulāro augu un sūnu sugas …
Environmental control on granular clinoforms of ancient carbonate shelves
2006
The purpose of this paper is to document the influence of depositional environments on shallow-water, low-relief clinoforms from the description of five ancient carbonate platforms: the Neoproterozoic (Namibia), Middle Jurassic (France), Lower Cretaceous (France), Upper Cretaceous (Oman) and Miocene (Turkey). These examples have been investigated on the basis of field observations. The clinoforms are described with reference to geometric and compositional attributes: declivity, shape, height, sedimentary structures, sediment fabric and components. The results show great variability in stratal geometry, declivity and facies distribution: (1) depositional profiles vary from exponential, to si…
Parasitismo por cestodos en Artemia spp. y su implicación en la invasión biológica de Artemia franciscana en la región Mediterránea
2015
La presente Tesis Doctoral trata del fenómeno del parasitismo en el crustáceo Artemia y la implicación de los cestodos en el proceso de invasión biológica de la especie americana Artemia franciscana Kellogg, 1906 en la región Mediterránea. El crustáceo Artemia (Branchiopoda, Anostraca) es el invertebrado más conspicuo de los ecosistemas acuáticos hipersalinos de todo el mundo y un valioso recurso trófico para las poblaciones de aves acuáticas que residen en dichos ecosistemas. El uso generalizado de la especie americana A. franciscana en la acuicultura y acuariofilia han provocado su introducción y expansión fuera de su área nativa, localizándose en la actualidad en todos los continentes y …