6,664 research outputs found
Attention and Visibility in an Information Rich World
As the rate of content production grows, we must make a staggering number of
daily decisions about what information is worth acting on. For any flourishing
online social media system, users can barely keep up with the new content
shared by friends. How does the user-interface design help or hinder users'
ability to find interesting content? We analyze the choices people make about
which information to propagate on the social media sites Twitter and Digg. We
observe regularities in behavior which can be attributed directly to cognitive
limitations of humans, resulting from the different visibility policies of each
site. We quantify how people divide their limited attention among competing
sources of information, and we show how the user-interface design can mediate
information spread.Comment: Appearing in 2nd International Workshop on Social Multimedia Research
2013, in conjunction with IEEE International Conference on Multimedia & Expo
(ICME 2013
Coronary artery disease risk and lipidomic profiles are similar in hyperlipidemias with family history and population-ascertained hyperlipidemias
Distribution of enzymes cleaving pyridine nucleotides in animal tissues
A number of enzymes capable of splitting the pyridine nucleotides have been found in animal tissues. A portion of the DPNase (1) that hydrolyzes the nicotinamide ribose bond of DPN and TPN was reported in the microsomes of rat liver (1). The DPN pyrophosphorylase, first described by Kornberg (2), has been found by Hogeboom and Schneider to be largely localized in the nucleus (3). In previous investigations (4) an enzyme from pigeon liver which splits DPNH and not DPN at the pyrophosphate linkage was described. The present communication deals with the intracellular distribution of enzymes from various species that attack the pyridine coenzymes at the pyrophosphate linkage. The distribution and properties of DPNases from different species and tissues will also be presented
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