Polyunsaturated fatty acids in various macroalgal species from north Atlantic and tropical seas

Background - In this study the efficacy of using marine macroalgae as a source for polyunsaturated fatty acids, which are associated with the prevention of inflammation, cardiovascular diseases and mental disorders, was investigated. Methods - The fatty acid (FA) composition in lipids from seven sea weed species from the North Sea (Ulva lactuca, Chondrus crispus, Laminaria hyperborea, Fucus serratus, Undaria pinnatifida, Palmaria palmata, Ascophyllum nodosum) and two from tropical seas (Caulerpa taxifolia, Sargassum natans) was determined using GCMS. Four independent replicates were taken from each seaweed species. Results - Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acids (PUFAs), were in the concentration range of 2-14 mg/g dry matter (DM), while total lipid content ranged from 7-45 mg/g DM. The n-9 FAs of the selected seaweeds accounted for 3%-56% of total FAs, n-6 FAs for 3%-32% and n-3 FAs for 8%-63%. Red and brown seaweeds contain arachidonic (C20:4, n-6) and/or eicosapentaenoic acids (EPA, C20:5, n-3), the latter being an important "fish" FA, as major PUFAs while in green seaweeds these values are low and mainly C16 FAs were found. A unique observation is the presence of another typical "fish" fatty acid, docosahexaenoic acid (DHA, C22:6, n-3) at ˜ 1 mg/g DM in S. natans. The n-6: n-3 ratio is in the range of 0.05-2.75 and in most cases below 1.0. Environmental effects on lipid-bound FA composition in seaweed species are discussed. Conclusion - Marine macroalgae form a good, durable and virtually inexhaustible source for polyunsaturated fatty acids with an (n-6) FA: (n-3) FA ratio of about 1.0. This ratio is recommended by the World Health Organization to be less than 10 in order to prevent inflammatory, cardiovascular and nervous system disorders. Some marine macroalgal species, like P. palmata, contain high proportions of the "fish fatty acid" eicosapentaenoic acid (EPA, C20:5, n-3), while in S. natans also docosahexaenoic acid (DHA, C22:6, n-3) was detected

Quantity and Quality of Support for Digital Engagement

Following the course taking by digital divide or digital inclusion research, this paper uses socio-cultural, socio-economic, social, and digital indicators to predict access to and the type of potential and actual social support networks that might help an individual in using the Internet. In addition, the paper examines the quality of the support received which is neglected in most investigations that mainly focus on quantitative indicators of support. The study draws on a representative survey conducted in the Netherlands; 1,149 responses were obtained. The results show that while there are no real inequalities in access to and use of support, the quality of the support that people access is unequally distributed replicating existing patterns of disadvantag

A nuanced understanding of Internet use and non-use among the elderly

This article examines explanations for both Internet use and non-use by older individuals. Older adults are often considered a homogeneous group with uniform reasons for Internet non-use, or when they are online, practising a uniform range of activities. The study gathered data concerning senior non-users through a national telephone survey. Data concerning senior Internet users were obtained through a nationally representative online survey. The findings suggest that although a substantial part of the senior Internet non-users live in surroundings that enable Internet uptake, they seem to be less eager or unable to do so. Important differences among senior non-users are based on gender, age, education, household composition and attitude towards the Internet. Differences among users were based on life stage, social environment and psychological characteristics. This article thus reveals that older citizens are a very diverse group in which some are more likely to be digitally excluded than other

Phenolic Compounds Present in Medicinal Mushroom Extracts Generate Reactive Oxygen Species in Human Cells In Vitro

Hot-water extracts of the higher Basidiomycetes Agaricus bisporus (J. Lge) Imbach, A. brasiliensis S. Wasser et al., Coprinus comatus (O.F. Mull.) Pers., Ganoderma lucidum (W. Curt.: Fr.) P. Karst., and Phellinus linteus (Berk. et Curt.) Teng were made, and the resulting polysaccharide mixtures were purified by DEAF-cellulose chromatography and ethanol precipitation. The extracts were noncytopathic. A. bisporus, A. brasiliensis, and G. lucidum strongly generated reactive oxygen species (ROS) in human PBMCs and K 562 cells. C. comatus and Ph. linteus extracts had low ROS-generating capacity. In A. bisporus extract, two different classes of polysaccharides were found. The colorless polysaccharide of MW > 250 kDa caused no intracellular ROS generation; acid hydrolysis followed by HPLC analysis showed it to consist of only glucose residues, thus being a pure glucan. The light brown polyphenol/polysaccharide complex of MW 75-200 kDa was found to strongly generate ROS. ROS generation by medicinal mushrooms could therefore be due to the presence of polyphenols rather than of glucan alone. A. bisporus polysaccharide extract showed a saturation level of ROS generation at 2 mg mL(-1). Generation appeared to continue in the presence of polysaccharide for more than 14 hours. Purified colorless polysaccharides of C. comatus and Ph. linteus showed no ROS generation in K562 cells; G. lucidum and A. brasiliensis polysaccharides could not completely be cleaned of phenolic compounds and remained active. Competitive inhibition of ROS generation by laminarin was not observed for any of the polysaccharide extracts, suggesting that polyphenol/glucan complexes isolated from higher Basidiomycetes mushrooms are able to generate ROS without binding to a dectin receptor