Impact of environmental factors on stilbene biosynthesis

Stilbenes are a small family of polyphenolic secondary metabolites that can be found in several distantly related plant species. These compounds act as phytoalexins, playing a crucial role in plant defense against phytopathogens, as well as being involved in the adaptation of plants to abiotic environmental factors. Among stilbenes, trans-resveratrol is certainly the most popular and extensively studied for its health properties. In recent years, an increasing number of stilbene compounds were subjected to investigations concerning their bioactivity. This review presents the most updated knowledge of the stilbene biosynthetic pathway, also focusing on the role of several environmental factors in eliciting stilbenes biosynthesis. The effects of ultraviolet radiation, visible light, ultrasonication, mechanical stress, salt stress, drought, temperature, ozone, and biotic stress are reviewed in the context of enhancing stilbene biosynthesis, both in planta and in plant cell and organ cultures. This knowledge may shed some light on stilbene biological roles and represents a useful tool to increase the accumulation of these valuable compounds

Beyond the digital divide: Towards a situated approach to open data

This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Poor provision of information and communication technologies in low/middle-income countries represents a concern for promoting Open Data. This is often framed as a “digital divide” and addressed through initiatives that increase the availability of information and communication technologies to researchers based in low-resourced environments, as well as the amount of resources freely accessible online, including data themselves. Using empirical data from a qualitative study of lab-based research in Africa we highlight the limitations of such framing and emphasize the range of additional factors necessary to effectively utilize data available online. We adopt the ‘Capabilities Approach’ proposed by Sen to highlight the distinction between simply making resources available, and doing so while fostering researchers’ ability to use them. This provides an alternative orientation that highlights the persistence of deep inequalities within the seemingly egalitarian-inspired Open Data landscape. The extent and manner of future data sharing, we propose, will hinge on the ability to respond to the heterogeneity of research environments.The research informing this article was supported by a grant from the Leverhulme Trust title ‘Beyond the Digital Divide’ (RPG-2013-153). Sabina Leonelli was also funded by the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreement n° 335925. Ann Kelly’s contribution was also supported by UK Economic Social Research Council Urgency Grants mechanism (ES/M009203/1)

The intramolecular aldol condensation of 3-oxocyclohexaneacetaldehydes: A useful tool in the synthesis of natural products

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Investigation on the effect of inorganic acid attack on composite prepared with MK-based geopolymer and waste cork dust

The chemical, microstructural and mechanical characterization of novel lightweight composites produced by adding waste cork dust to a metakaolin-based geopolymeric matrix prepared by alkaline activation is presented. The alkaline activator solutions used for the reticulation of the 3D aluminosilicate network at room temperature are composed of NaOH and sodium silicate to maintain a low cost of the final composite. In this line, the research of the highest addition of waste, e.g. cork dust, is pursued starting from 1 and reaching a maximum content of 10 wt% over metakaolin. The chemical stability is evaluated in water as well as in HNO3 or in H2SO4 0.5 and 2.5 N solutions. The addition of cork does not affect the reticulation of the geopolymeric binder used as matrix, as is demonstrated by FT-IR and XRD analyses. The modification of the dense geopolymeric microstructure with the introduction of cork dust weakens the hardened composites that become more permeable to water and acid solutions increasing the weight loss after immersion and decreasing the mechanical resistance to compression. The mechanical performance of the hardened composite with 10 wt% of cork dust still seems to be sufficient for application as self-supporting thermal insulation panels

Anchoring effect in visual information processing during financial decisions: an eye-tracking study

When reading a financial disclosure document, subjects are faced with multiple information cues and might simplify decisional complexity by relying on heuristics. This study explores whether, in an attempt to filter information from the Payment Account Fees Information Document (FID), subjects anchor their evaluation to a specific item, leading to biased financial choices. By detecting the visual search strategy in 70 subjects through eye tracking, we observed that people exhibited systematic visual anchoring to the top of the document, which corresponds to the Liquidity section that displays the Annual Fee. Moreover, data revealed that subjects sometimes fail to recognize the most advantageous products. This mainly occurs when the Annual Fee is high, even if the other charges compensate for that amount, clarifying the link between visual search strategy and financial decisions. Data also showed the role of financial literacy in modulating attention, as poorly financially literate subjects are more prone to anchoring bias. The findings contribute to the neuroeconomics literature on anchoring effect and highlight practical implications for financial regulators and managers involved in the ergonomics of documents

Recycling of Waste Corundum Abrasive Powder in Mk-Based Geopolymers

Recycling corundum abrasive powder in metakaolin-based geopolymer formulations is proposed to reduce the amount of waste to be treated or disposed of in landfills, allowing to decrease ecological damage as well as to reduce transport costs for removal. The addition of waste corundum, as an important source of Al2O3, has proved to increase the slightly ionic conductivity of the leachate solution obtained after immersion in water of samples at 28 d of curing at room temperature. With the same curing conditions, the geopolymerization process has not been disturbed as evidenced by the FT-IR peak shift and XRD patterns. It was recorded a decrease in resistance to compression of the consolidated geopolymers of about 5% with 10 wt% addition and of about 77% with the addition of 20 wt% of waste corundum. In any case, the waste abrasive powder does not release heavy metals when added to a geopolymeric formulation based on MK, NaOH, and Na-silicate, and does not show relevant antibacterial properties, indicating the formation of a stable and safe final product with a ceramic-like appearance

Binder chemistry – Low-calcium alkali-activated materials

Early developments in the developments of low-calcium (including calcium-free) alkali-activated binders were led by the work of Davidovits in France, as noted in Chap. 2. These materials were initially envisaged as a fire-resistant replacement for organic polymeric materials, with identification of potential applications as a possible binder for concrete production following relatively soon afterwards [1]. However, developments in the area of concrete production soon led back to more calcium-rich systems, including the hybrid Pyrament binders, leaving work based on the use of low-calcium systems predominantly aimed at high-temperature applications and other scenarios where the ceramic-like nature of clay-derived alkali-activated pastes was beneficial. Early work in this area was conducted with an almost solely commercial focus, meaning that little scientific information was made available with the exception of a conference proceedings volume [2], several scattered publications in other conferences, and an initial journal publication [3]. Academic research into the alkaline activation of metakaolin to form a binder material led to initial publications in the early 1990s [4, 5], and the first description of the formation of a strong and durable binder by alkaline activation of fly ash was published by Wastiels et al. [6-8]. With ongoing developments in fly ash activation, which offers more favourable rheology than is observed in clay-based binders, interest in low-calcium AAM concrete production was reignited, and work since that time in industry and academia has led to the development of a number of different approaches to this problem. A review of the binder chemistry of low-calcium AAM binder systems published in 2007 [9] has since received more than 350 citations in the scientific literature, indicating the high current level of interest in understanding and utilisation of these types of gels

The origin of the E+ transition in GaAsN alloys

Optical properties of GaAsN system with nitrogen concentrations in the range of 0.9-3.7% are studied by full-potential LAPW method in a supercell approach. The E+ transition is identified by calculating the imaginary part of the dielectric function. The evolution of the energy of this transition with nitrogen concentration is studied and the origin of this transition is identified by analyzing the contributions to the dielectric function from different band combinations. The L_1c-derived states are shown to play an important role in the formation of the E+ transition, which was also suggested by recent experiments. At the same time the nitrogen-induced modification of the first conduction band of the host compound are also found to contribute significantly to the E+ transition. Further, the study of several model supercells demonstrated the significant influence of the nitrogen potential on the optical properties of the GaAsN system.Comment: 5 pages, 3 figure