1,904 research outputs found

    Origin of peer influence in social networks

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    Social networks pervade our everyday lives: we interact, influence, and are influenced by our friends and acquaintances. With the advent of the World Wide Web, large amounts of data on social networks have become available, allowing the quantitative analysis of the distribution of information on them, including behavioral traits and fads. Recent studies of correlations among members of a social network, who exhibit the same trait, have shown that individuals influence not only their direct contacts but also friends' friends, up to a network distance extending beyond their closest peers. Here, we show how such patterns of correlations between peers emerge in networked populations. We use standard models (yet reflecting intrinsically different mechanisms) of information spreading to argue that empirically observed patterns of correlation among peers emerge naturally from a wide range of dynamics, being essentially independent of the type of information, on how it spreads, and even on the class of underlying network that interconnects individuals. Finally, we show that the sparser and clustered the network, the more far reaching the influence of each individual will be.Financial support by FEDER through POFC-COMPETE and by FCT-Portugal is gratefully acknowledged through Grants No. SFRH/BD/77389/2011, No. SFRH/BPD/90936/2012, No. PTDC/MAT/122897/2010, No. EXPL/EEI-SII/2556/2013, No. PEst-OE/EEI/LA0021/2013, and No. PEst-OE/BIA/UI4050/2014

    Social diversity favors the emergence of cooperative behavior

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    Throughout their life, humans often engage in public goods games in situations ranging from family related issues to global warming. In all cases, the tragedy of the commons threatens the possibility of reaching the optimal solution associated with global cooperation. Up to now, individuals have been treated as equivalent in all respects, in sharp contrast with real life situations, where diversity abounds. Here we discuss the results reported in [Santos et al. Nature (2008) 454:213-6], where we show how social diversity provides an escape from this paradox. We investigate the impact of social diversity in the evolution of cooperation in complex networks of interaction. We show that the diversity in the number and size of the collective endeavors each individual participates and with the individual contribution to each investment promotes cooperation. The enhancement of cooperation is particularly strong when both wealth and social ties follow a power-law distribution, providing clues on the self-organization of social communities.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

    Correction to: The first Paenibacillus larvae bacteriophage endolysin (PlyPl23) with high potential to control American foulbrood

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    The Data Availability statement for this paper is incorrect. The correct statement is: All relevant data are within the paper and its Supporting Information files, except the aminoacidic sequence of the endolysin, which is available in RefSeq, accession number YP_008320357.1

    Development of a dextrin-based hydrogel for bone regeneration

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    [Excerpt] Bone tissue engineering is a very challenging and promising field, which handles with the limitations of bone regenerative capacity and the failure of current orthopedic implants [1]. This work describes the preparation and characterization of an injectable dextrin-based hydrogel (oDex) able to incorporate nanoparticles, cells, biomolecules or Bonelike~ granules [2]. (...

    Crosstalk between ROS Homeostasis and Secondary Metabolism in S. natalensis ATCC 27448: Modulation of Pimaricin Production by Intracellular ROS

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    Streptomyces secondary metabolism is strongly affected by oxygen availability. The increased culture aeration enhances pimaricin production in S. natalensis, however the excess of O2 consumption can lead to an intracellular ROS imbalance that is harmful to the cell. The adaptive physiological response of S. natalensis upon the addition of exogenous H2O2 suggested that the modulation of the intracellular ROS levels, through the activation of the H2O2 inducible catalase during the late exponential growth phase, can alter the production of pimaricin. With the construction of defective mutants on the H2O2 related enzymes SodF, AhpCD and KatA1, an effective and enduring modulation of intracellular ROS was achieved. Characterization of the knock-out strains revealed different behaviours regarding pimaricin production: whilst the superoxide dismutase defective mutant presented low levels of pimaricin production compared to the wild-type, the mutants defective on the H2O2-detoxifying enzymes displayed a pimaricin overproducer phenotype. Using physiological and molecular approaches we report a crosstalk between oxidative stress and secondary metabolism regulatory networks. Our results reveal that the redox-based regulation network triggered by an imbalance of the intracellular ROS homeostasis is also able to modulate the biosynthesis of pimaricin in S. natalensis

    Nutritional, rheological, sensory characteristics and environmental impact of a yogurt-like dairy drink for children enriched with lupin flour

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    Studies have demonstrated that the addition of pulses to foods can make them more nutritious. We hypothesize that lupin flour adds nutritional benefits to yogurts. This study aimed to characterize a lupin-enriched yogurt in nutritional, rheological, and sensorial terms by a trained panel, and assess its environmental impact using the life cycle assessment (LCA) approach. For comparison, natural yogurt and a commercial formula were used as controls. The developed yogurt is “high in protein” (7g/100g), “source of fiber” (1.9g/100g), and “source of omega 3” (53 mg/100g). The lupin yogurt was the stiffest with the highest viscosity than controls according to rheological parameters. There were no significant sensory differences between the lupin-enriched yogurt and the controls, although some undesirable sensory characteristics such as bitterness, granularity, and after-taste were observed. The environmental impact per 100 g serving was similar to natural yogurt and slightly worse regarding commercial yogurt but better when expressed per Nutritional Density Unit (NDU). Using lupin flour to enrich yogurts for children can be an alternative to producing more nutritious products.N/
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