Visualization for exploratory analysis of spatio-temporal data

Analysis of spatio-temporal data has become critical with the emerge of ubiquitous location sensor technologies and applications keeping track of such data. Especially with the widespread availability of low cost GPS devices, it is possible to record data about the location of people and objects at a large scale. Data visualization plays a key role in the successful analysis of these kind of data. Due to the complex nature of this analysis process, current approaches and analytical tools fail to help spatio-temporal thinking and they are not effective when solving large range of problems. In this work, we propose an interactive visualization tool to support human analyst understand user behaviors by analyzing location patterns and anomalies in massive collections of spatio-temporal data. The tool that we developed within this work combines a geovisualization framework with 3D visualizations and histograms. Tool's effectiveness in exploratory analysis is tested by trend analysis and anomaly detection in a real mobile service dataset with almost 1.5 million rows

Entropy Based Sensitivity Analysis and Visualization of Social Networks

Abstract. This paper introduces a technique to analyze and visualize a social network using Shannon's entropy model. We used degree entropy and presented novel measures such as, betweenness and closeness entropies to conduct network sensitivity analysis by means of evaluating the change of graph entropy via those measures. We integrated the result of our analyses into a visualization application where the social network is presented using node-link diagram. The size of visual representation of an actor depends on the amount of change in system entropy caused by the actor and color information is extracted from the graph clustering analysis. Filtering of edges and nodes is also provided to enable and improve the perception of complex graphs. The main contribution is that the information communicated from a social network is enhanced by means of sensitivity analyses and visualization techniques provided with this work

A Comparative Study for the Evaluation of Two Doses of Ellagic Acid on Hepatic Drug Metabolizing and Antioxidant Enzymes in the Rat

The present study was designed to evaluate different doses of ellagic acid (EA) in vivo in rats for its potential to modulate hepatic phases I, II, and antioxidant enzymes. EA (10 or 30 mg/kg/day, intragastrically) was administered for 14 consecutive days, and activity, protein, and mRNA levels were determined. Although the cytochrome P450 (CYP) 2B and CYP2E enzyme activities were decreased significantly, the activities of all other enzymes were unchanged with the 10 mg/kg/day EA. In addition, western-blot and qRT-PCR results clearly corroborated the above enzyme expressions. On the other hand, while the NAD(P)H:quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activities were increased significantly, CYP1A, 2B, 2C, 2E, and 19 enzyme activities were reduced significantly with 30 mg/kg/day EA. In addition, CYP2B, 2C6, 2E1, and 19 protein and mRNA levels were substantially decreased by the 30 mg/kg/day dose of EA, but the CYP1A protein, and mRNA levels were not changed. CYP3A enzyme activity, protein and mRNA levels were not altered by neither 10 nor 30 mg/kg/day ellagic acid. These results indicate that EA exerts a dose-dependent impact on the metabolism of chemical carcinogens and drugs by affecting the enzymes involved in xenobiotics activation/detoxification and antioxidant pathways

Entropy Assisted Automated Terrain Navigation using Traveling Salesman Problem

Abstract Navigation in 3D terrain is considered to be a challenging task and requires virtual camera control skills such as zooming, panning and tilting. Novice users can easily get distracted and disoriented that may result with lost in space. Methods to overcome the virtual environment exploration problems are still being researched to assist users during their journey inside virtual environments. Assisted camera control techniques require viewpoint computation and path planning. This paper introduces a novel approach to navigate over a 3D terrain with minimal loss of information. We exploit the concept of the Viewpoint Entropy for best view determination and use our Greedy N-Best View Selection for visibility calculations. We integrate road network data to extract regions for detailed visibility analysis in subsections of the terrain. In order to connect the calculated viewpoints an evolutionary programming approach for Traveling Salesman problem is used where the distance objective is minimized. The generated tour is presented using Google Earth framework for terrain exploration where we can get real data streams. The computed and planned viewpoints reduces human effort when used as starting points for scene exploration or generating the representative images of the terrain dataset. The proposed framework can be integrated into 3D game engines or any urban visualization system to give quick glimpse or tour of the environment for the novice users without the help of prior planning

Automatic path generation for terrain navigation

Navigation in 3D terrain is considered to be a challenging task and requires virtual camera control skills such as zooming, panning and tilting. Novice users can easily get distracted and disorientated which may result in being lost in space. Solutions for the virtual environment exploration problems are still being researched in order to assist users during their journey inside virtual environments. Among these solutions, assisted camera control techniques require viewpoint computation and path planning. This paper introduces a novel approach to navigate over a 3D terrain using best viewpoints. We exploit the concept of Viewpoint Entropy for best view determination and use Greedy N-Best View Selection for visibility calculations. We integrate road network data to extract regions for detailed visibility analysis in subsections of the terrain. In order to connect the calculated viewpoints, we use an evolutionary programming approach for the Traveling Salesman problem. We present the generated tour using a Google Earth framework. The computed and planned viewpoints in our solution reduce human effort when used as starting points for scene exploration or to generate the representative images of the terrain dataset. The proposed framework can be integrated into 3D game engines or urban visualization systems. This integration gives quickly a glimpse or tour of the environment for novice users without the help of prior planning. Furthermore, terrain visibility used together with road network data and an optimization method for final path construction allows the computed path to be used for large urban area reconnaissance and surveillance tasks with aerial vehicles

In vivo examination of the effects of hydroxycinnamic acid on xenobiotic metabolizing and antioxidant enzymes

In the last decade, hydroxycinnamic acids (HCA) have gained increasing attention from researchers due to their antioxidant potential. The aim of this study was to examine in detail the impact of dietary HCA on particular types of P450 and also selected phase II and antioxidant enzymes in Wistar rat. HCA (10 mu M/kg/day, i.p.) was administered for ten continuous days. Examination of the activities and mRNA and protein levels revealed that CYP2B, 2C6 and 3A enzyme activities were not altered significantly, with Western blot and qRT-PCR results corroborating this result. While treatment with HCA led to a significant reduction in CYP1A1/CYP1A2-associated enzyme activities, CYP1A1 protein, and mRNA levels were found to be unchanged. Aromatase (CYP19) activity, as well as protein and mRNA levels, were significantly reduced with HCA treatment. On the other hand, the NAD(P) H: quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferases (GSTs) activities were increased significantly. Also, HCA treatment significantly increased the GST-mu and GST-theta mRNA levels

In vivo examination of the effects of hydroxycinnamic acid on xenobiotic metabolizing and antioxidant enzymes

In the last decade, hydroxycinnamic acids (HCA) have gained increasing attention from researchers due to their antioxidant potential. The aim of this study was to examine in detail the impact of dietary HCA on particular types of P450 and also selected phase II and antioxidant enzymes in Wistar rat. HCA (10 mM/kg/day, i.p.) was administered for ten continuous days. Examination of the activities and mRNA and protein levels revealed that CYP2B, 2C6 and 3A enzyme activities were not altered significantly, with Western blot and qRT-PCR results corroborating this result. While treatment with HCA led to a significant reduction in CYP1A1/CYP1A2-associated enzyme activities, CYP1A1 protein, and mRNA levels were found to be unchanged. Aromatase (CYP19) activity, as well as protein and mRNA levels, were significantly reduced with HCA treatment. On the other hand, the NAD(P)H:quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferases (GSTs) activities were increased significantly. Also, HCA treatment significantly increased the GST-mu and GST-theta mRNA levels. These observations may be of importance given the potential use of HCA as a chemopreventive and as an anticancer agent