Role of paramagnetic polyconjugated clusters in lignin antioxidant activity (in vitro)

Using physico-chemical methods (EPR, SEC, Py-GC/MS and UV/VIS spectroscopy) and wet chemical analysis, the characteristics of 6 hardwood lignins in terms of functionality, molecular weight and composition of lignin substructures were determined and considered together with the results of DPPH•, ABTS •+ and O2•- antioxidant assays with the aim to understand the relationships governing antioxidant properties of lignin. The strong positive linear correlation between lignin antioxidant capacity in the three assays used and the extent of conjugation of paramagnetic polyconjugated clusters in lignin macromolecules was found. The biological activity of the most active alkaline lignins was assessed by in vitro experiment with human blood.publishersversionPeer reviewe

Good Friends, Bad News - Affect and Virality in Twitter

The link between affect, defined as the capacity for sentimental arousal on the part of a message, and virality, defined as the probability that it be sent along, is of significant theoretical and practical importance, e.g. for viral marketing. A quantitative study of emailing of articles from the NY Times finds a strong link between positive affect and virality, and, based on psychological theories it is concluded that this relation is universally valid. The conclusion appears to be in contrast with classic theory of diffusion in news media emphasizing negative affect as promoting propagation. In this paper we explore the apparent paradox in a quantitative analysis of information diffusion on Twitter. Twitter is interesting in this context as it has been shown to present both the characteristics social and news media. The basic measure of virality in Twitter is the probability of retweet. Twitter is different from email in that retweeting does not depend on pre-existing social relations, but often occur among strangers, thus in this respect Twitter may be more similar to traditional news media. We therefore hypothesize that negative news content is more likely to be retweeted, while for non-news tweets positive sentiments support virality. To test the hypothesis we analyze three corpora: A complete sample of tweets about the COP15 climate summit, a random sample of tweets, and a general text corpus including news. The latter allows us to train a classifier that can distinguish tweets that carry news and non-news information. We present evidence that negative sentiment enhances virality in the news segment, but not in the non-news segment. We conclude that the relation between affect and virality is more complex than expected based on the findings of Berger and Milkman (2010), in short 'if you want to be cited: Sweet talk your friends or serve bad news to the public'.Comment: 14 pages, 1 table. Submitted to The 2011 International Workshop on Social Computing, Network, and Services (SocialComNet 2011

Seeing versus Doing: How Businesses Manage Tensions in Pursuit of Sustainability

Management of organizational tensions can facilitate the simultaneous advancement of economic, social, and environmental priorities. The approach is based on managers identifying and managing tensions between the three priorities, by employing one of the three strategic responses. Although recent work has provided a theoretical basis for such tension acknowledgment and management, there is a dearth of empirical studies. We interviewed 32 corporate sustainability managers across 25 forestry and wood-products organizations in Australia. Study participants were divided into two groups: (1) those considered effective at corporate sustainability and (2) a status-quo group. Contrary to current theory, our findings showed that acknowledgment of organizational tensions was widespread in the Australian forestry and wood-products industry and not limited to those managers who are effective at managing corporate sustainability. What differed was the degree to which managers did something about the perceived tensions—with the effective group more consistently acting to manage and resolve paradoxical scenarios. Our findings suggest that existing theoretical constructs of tension management may not adequately capture the individual-level complexity involved with managing tensions in practice

Plasma–liquid interactions: a review and roadmap

Plasma–liquid interactions represent a growing interdisciplinary area of research involving plasma science, fluid dynamics, heat and mass transfer, photolysis, multiphase chemistry and aerosol science. This review provides an assessment of the state-of-the-art of this multidisciplinary area and identifies the key research challenges. The developments in diagnostics, modeling and further extensions of cross section and reaction rate databases that are necessary to address these challenges are discussed. The review focusses on non-equilibrium plasmas

Production of nanoporous carbons from wood processing wastes and their use in supercapacitors and CO2 capture

Highly porous carbons were obtained from solid wastes generated in the chemical and the mechanical processing of birch wood (substandard kraft cellulose, hydrolysis lignin, chips and bark). NaOH-chemical activation of these residues at 575–800 °C resulted in an efficient process to produce carbons with specific surface areas well above 1000 m2 g−1 and average pore widths of 1–1.7 nm. Comparative evaluations have shown the potentiality of wood wastes-based carbons in applications related to environmental protection. Activated carbons derived from chips- and bark-birch wood displayed specific capacitances as high as 308 F g−1 in the H2SO4 aqueous electrolyte and 200 F g−1 in the (C2H5)4NBF4/acetonitrile organic medium. Moreover, their capacitive performance at high current density competed well with that found for commercial carbons used in supercapacitors. Wood-derived carbons also proved to be highly promising for CO2 capture in power stations, achieving uptakes under post- and pre-combustion conditions of 11–16 wt.% and 49–91 wt.%, respectively.The research leading to these results has received funding support of the European Community’s Service Framework Programme (FP7/2007-2011,203459), from the Latvian Budget (Grant 1546), and the Latvian National Programme VPP-2,2.4,1.1.Peer reviewe

Facebook wall posts: What sort achieves the most interaction?

While the potential of social media has empowered consumers, giving rise to ever greater abilities to interact and create conversations among very large audiences, the marketing adoption of social media is more difficult. For example, meaningful understanding of consumer motivations for information exchanges is lacking (e.g. Schmitt, Skiera, & van den Bulte, 2011; Van der Lans & Van Bruggen, 2011). From a practitioner perspective implementing a digital media viral marketing campaign 'can be tricky for advertisers to tap into' (Leskovec, Adamic and Huberman, 2007, p. 2). Failed viral campaigns remain the norm (Mills, 2012; Van der Lans & Van Bruggen, 2011) and 'success in this area remains elusive to most firms' (Ferguson, 2008, p. 68; Kalyanam, McIntyre, & Masonis, 2007)

Py-GC/MS for Characterization of Non-Hydrolyzed Residues from Bioetanol Production from Softwood

Analytical pyrolysis combined with gas chromatography/mass spectrometry (Py-GC/MS) was used to analyze chemical composition of non-hydrolyzed residues (LHRs) obtained by three methods of bioethanol production: softwood acid hydrolysis (AH), separate enzymatic hydrolysis and fermentation (SHF), and simultaneous saccharification and fermentation (SSF). Complementary techniques, such as EPR- and FTIR-spectroscopy, and routine chemical analysis procedures were used for this study as well. The Py-GC/MS analysis of the LHRs has shown a higher efficiency of carbohydrates hydrolysis upon SSF process in comparison with SHF and AH processes. Comparison of chemical analysis results and data obtained by Py-GC/MS of LHRs brought the direct evidence of incorporation of carbohydrates-derived fragments into the lignin matrix and formation of so-called pseudo-lignin upon different stages of softwood processing. Modifications of lignin component of LHRs on various stages of the process of bioethanol production, such as oxidation and condensation reactions, cleavage of ether bonds and destruction of side propane chain, were revealed using Py-GC/MS