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This paper recommends a new approach to the detection and containment of Web crawler traverses based on clickstream data mining. Timely detection prevents crawler abusive consumption of Web server resources and eventual site contents privacy or copyrights violation. Clickstream data differentiation ensures focused usage analysis, valuable both for regular users and crawler profiling. Our platform, named ClickTips, sustains a sitespecific, updatable detection model that tags Web crawler traverses based on incremental Web session inspection and a decision model that assesses eventual containment. The goal is to deliver a model flexible enough to keep up with crawling continuous evolving and that is capable of detecting crawler presence as soon as possible. We use a real-world Web site case study as a support for process description, as well as, to evaluate the accuracy of the obtained classification models and their ability for discovering previously unknown Web crawlers.

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Objective: To compare the circulating levels of MMP-2 and TIMP-2 and the MMP-2/TIMP-2 ratio in control, obese, and obese hypertensive children and adolescents and to assess whether hypoadiponectinemia is associated with MMP-2 and TIMP-2 levels and MMP-2/TIMP-2 ratios. Methods: Studies were carried out with 53 control, 73 obese, and 29 obese hypertensive children and adolescents in this cross-sectional study. Adiponectin and TIMP-2 concentrations were measured by ELISA. MMP-2 concentrations were measured by gelatin zymography. Multiple linear regression analysis was carried out to assess the effects of adiponectin on MMP-2 and TIMP-2 levels and MMP-2/TIMP-2 ratios. Results: The obese hypertensive group had the lowest adiponectin levels among groups (P < 0.05) while obese subjects had lower adiponectin levels than control subjects (P < 0.05). Obese hypertensive subjects also had higher circulating MMP-2 concentrations than obese subjects (P < 0.05) and had the highest MMP-2/TIMP-2 ratios among groups (P < 0.05). Moreover, obese/hypertensive subjects had the lowest TIMP-2 levels among groups (P < 0.05). A multiple linear regression analysis showed that MMP-2 levels and MMP-2/TIMP-2 ratios are negatively associated with adiponectin levels (P 5 0.034 and P 5 0.011, respectively) while TIMP-2 levels is positively associated with adiponectin levels (P 5 0.013). Conclusions: Increased activity of MMP-2 (MMP-2/TIMP-2 ratio) and reduced TIMP-2 levels may play an important role in clinical hypertension of childhood obesity. Additionally, hypoadiponectinemia may contribute to increased activity of MMP-2 in obese/hypertensive children and adolescents.