1,224 research outputs found

    Pirates and Samaritans: A Decade of Measurements on Peer Production and their Implications for Net Neutrality and Copyright

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    This study traces the evolution of commons-based peer production by a measurementbased analysis of case studies and disusses the impact of peer production on net neutrality and copyright law. The measurements include websites such asSuprnova. org, Youtube.com, and Facebook.com, and the Peer-to-Peer (P2P) systems Kazaa, Bittorrent, and Tribler. The measurements show the two sides of peer production, the pirate side with free availability of Hollywood movies on these P2P systems and the samaritan side exhibited by the quick joining of 400,000+ people in a community to organize protests against events in Burma. The telecommunications and content industry are disrupted by this way of peer production. As a consequence, revenues of both industries are likely to suffer in the coming years. On the other hand, innovative P2P systems could win the battle on merit over classical distribution technologies. As a result, a continuation is expected of both legal actions against P2P and possible blocking actions of P2P traffic, violating net neutrality. It is argued that this hinders innovation and causes a large discrepancy between legal and user perspectives. A reform of copyright laws are clearly needed, otherwise they will be unenforceable around 2010. Key words: P2P, collaboration, commons-based peer production, copyright

    A blinded comparison of fluticasone propionate with budesonide via powder devices in adult patients with moderate-to-severe asthma: a clinical evaluation

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    In Vitro and in vivo data have demonstrated that there are detectable differences between inhaled corticosteroids commonly used to treat asthma. However, controversy still remains as to whether these differences translate into clinical benefits. This 12-week, international, randomized, doubleblind, parallel-group study was undertaken to compare the efficacy and safety of fluticasone propionate (FP) 800 μg daily, administered as a powder via the Diskhaler®, and budesonide (BUD) 1600 μg daily, administered using the Turbuhaler®, in adult patients with moderate-tosevere asthma. A total of 518 patients participated in the study, 256 of whom received FP and 262 BUD. Assessment of mean morning peak expiratory flow (PEF) over the 12-week treatment period revealed a statistically significant difference in efficacy between FP 800 μg daily and BUD 1600 μg daily in favour of FP (p = 0.003), with an overall improvement of 20.9 l/min with FP compared with 12.4 l/min on BUD. Statistically significant differences in favour of FP were seen over the 12 weeks for mean evening PEF (p = 0.04), diurnal PEF variation (p = 0.03) and percentage predicted PEF (p = 0.003), as well as forced expiratory volume (p = 0.008), forced vital capacity (p = 0.02) and PEF (p = 0.005) measured at clinic visits. The median percentage of symptom-free nights increased over the 12-week study period in both treatment groups, with similar changes seen for the median percentage of days with symptom score < 2, rescue medication use and exacerbations of asthma. The incidence of adverse events was found to be comparable in the two treatment groups. The geometric mean ratios of serum cortisol levels were found to be 1.03 for FP, indicating no mean hypothalamic-pituitary-adrenal axis suppression from baseline, and 0.93 for BUD (p = 0.0002 compared with FP). In summary, FP 800 μg daily showed a greater efficacy/safety ratio in the treatment of moderate-to-severe asthma than BUD 1600 μg daily

    In Silico Analysis Identifies Intestinal Transit as a Key Determinant of Systemic Bile Acid Metabolism

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    Bile acids fulfill a variety of metabolic functions including regulation of glucose and lipid metabolism. Since changes of bile acid metabolism accompany obesity, Type 2 Diabetes Mellitus and bariatric surgery, there is great interest in their role in metabolic health. Here, we developed a mathematical model of systemic bile acid metabolism, and subsequently performed in silico analyses to gain quantitative insight into the factors determining plasma bile acid measurements. Intestinal transit was found to have a surprisingly central role in plasma bile acid appearance, as was evidenced by both the necessity of detailed intestinal transit functions for a physiological description of bile acid metabolism as well as the importance of the intestinal transit parameters in determining plasma measurements. The central role of intestinal transit is further highlighted by the dependency of the early phase of the dynamic response of plasma bile acids after a meal to intestinal propulsion

    Model-based data analysis of individual human postprandial plasma bile acid responses indicates a major role for the gallbladder and intestine

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    BACKGROUND: Bile acids are multifaceted metabolic compounds that signal to cholesterol, glucose, and lipid homeostasis via receptors like the Farnesoid X Receptor (FXR) and transmembrane Takeda G protein-coupled receptor 5 (TGR5). The postprandial increase in plasma bile acid concentrations is therefore a potential metabolic signal. However, this postprandial response has a high interindividual variability. Such variability may affect bile acid receptor activation. METHODS: In this study, we analyzed the inter- and intraindividual variability of fasting and postprandial bile acid concentrations during three identical meals on separate days in eight healthy lean male subjects using a statistical and mathematical approach. MAIN FINDINGS: The postprandial bile acid responses exhibited large interindividual and intraindividual variability. The individual mathematical models, which represent the enterohepatic circulation of bile acids in each subject, suggest that interindividual variability results from quantitative and qualitative differences of distal active uptake, colon transit, and microbial bile acid transformation. Conversely, intraindividual variations in gallbladder kinetics can explain intraindividual differences in the postprandial responses. CONCLUSIONS: We conclude that there is considerable inter- and intraindividual variation in postprandial plasma bile acid levels. The presented personalized approach is a promising tool to identify unique characteristics of underlying physiological processes and can be applied to investigate bile acid metabolism in pathophysiological conditions
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