A novel visible spectrum images-based pedestrian detection and tracking system for surveillance in non-controlled environments

Multimedia Tools and Applications - For many vision applications, robust detection and tracking of pedestrians in image sequences are essential. In this paper, a hybrid system for pedestrian...     

A new thermal infrared and visible spectrum images-based pedestrian detection system

In this paper, we propose a hybrid system for pedestrian detection, in which both thermal and visible images of the same scene are used. The proposed method is achieved in two basic steps: (1) Hypotheses generation (HG) where the locations of possible pedestrians in an image are determined and (2) hypotheses verification (HV), where tests are done to check the presence of pedestrians in the generated hypotheses. HG step segments the thermal image using a modified version of OTSU thresholding technique. The segmentation results are mapped into the corresponding visible image to obtain the regions of interests (possible pedestrians). A post-processing is done on the resulting regions of interests to keep only significant ones. HV is performed using random forest as classifier and a color-based histogram of oriented gradients (HOG) together with the histograms of oriented optical flow (HOOF) as features. The proposed approach has been tested on OSU Color-Thermal, INO Video Analytics and LITIV data sets and the results justify its effectiveness.

     

Encapsulation of Huh-7 cells within alginate-poly(ethylene glycol) hybrid microspheres

Novel calcium alginate poly(ethylene glycol) hybrid microspheres (Ca-alg-PEG) were developed and evaluated as potentially suitable materials for cell microencapsulation. Grafting 5–13% of the backbone units of sodium alginate (Na-alg) with α-amine-ω-thiol PEG maintained the gelling capacity in presence of calcium ions, while thiol end groups allowed for preparing chemically crosslinked hydrogel via spontaneous disulfide bond formation. The combination of these two gelling mechanisms yielded Ca-alg-PEG. Human hepatocellular carcinoma cells (Huh-7) were encapsulated in Ca-alg-PEG and calcium alginate beads (Ca-alg), and cultured for 2 weeks under agitation conditions. Immediately after completion of the microencapsulation, the cell viability was 60% and similar in Ca-alg-PEG and Ca-alg. The proliferation of Huh-7 encapsulated in Ca-alg-PEG was slightly higher than in Ca-alg. Accelerated proliferation after 2 weeks was observed for the encapsulation in Ca-alg-PEG. The production of albumin confirmed the functionality of the encapsulated Huh-7 cells. The study confirms the suitability of Ca-alg-PEG and the one-step technology for cell microencapsulation.     

Coupling structure-based design with combinatorial chemistry: application of active site derived pharmacophores with informative library design

Protein structural information is combined with combinatorial library design in the following protocol. Active site maps are generated from protein structures. All possible 2-, 3- and 4-point pharmacophores are enumerated from the active site map and encoded as bit strings. The pharmacophores define a design space that can be used to select compounds using an informative library design tool. The method was evaluated against a collection of compounds assayed previously against a cyclin-dependent kinase target, CDK-2, starting with 23 X-ray co-crystal structures. Performance was assessed based on the number of active scaffolds selected after four rounds of iterative informative library design. The method selects compounds from 12 out of the 15 active scaffolds from the CDK-2 library and outperforms a two-dimensional similarity search and docking calculations.     

Evaluation of antioxidant capacity of ulvan-like polymer obtained by regioselective oxidation of gellan exopolysaccharide

Gellan is an exopolysaccharide produced in high yield by the non-pathogenic bacterium Sphingomonas elodea ATCC 31461. In this study, four carboxylated derivatives of gellan (OG-1, OG-2, OG-3 and OG-4) with different uronics acid content were prepared using the TEMPO (nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl radical) mediated oxidation and their antioxidant activities were investigated including scavenging activity of hydroxyl, superoxide anion and 1,1-diphenyl-2-picryl-hydrazyl radicals. The results of chemical analysis and ¹³C NMR spectrums indicated that the modification was successful. In addition, certain derivative exhibited stronger antioxidant activity compared to that of native ones. The high uronic acids derivative (OG-4) showed the most excellent antioxidant activity in three assays. These results suggested the potential of TEMPO-mediated oxidation in developing water-soluble antioxidative polysaccharides from gellan still taking advantage of its low-cost production. The original carbohydrate structure of OG-4 derivative might find use as surrogates of ulvan, a cell-wall polysaccharides extracted from green seaweeds Ulva sp.     

Dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding

The dynamic mechanical properties of sisal fiber reinforced polyester composites fabricated by resin transfer molding (RTM) were investigated as a function of fiber content, frequency, and temperature. Investigation proved that at all temperature range the storage modulus (E′) value is maximum for the composites having fiber loading of 40 vol%. The loss modulus (E″) and damping peaks (tan δ) were lowered with increasing fiber content. The height of the damping peaks depends upon the fiber content and the fiber/matrix adhesion. The extent of the reinforcement was estimated from the experimental storage modulus, and it has been found that the effect of reinforcement is maximum at 40 vol% fiber content. As the fiber content increases the T_g from tan δ curve showed a positive shift. The loss modulus, storage modulus, and damping peaks were evaluated as a function of frequency. The activation energy for the glass transition increases upon the fiber content. Cole–Cole analysis was made to understand the phase behavior of the fiber reinforced composites. Finally, attempts were made to correlate the experimental dynamic properties with theoretical predictions. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Wheat flour thermoplastic matrix reinforced by waste cotton fibre: Agro-green-composites

New composites materials, 100% ecofriendly, having waste cotton fibre as reinforcement in wheat flour based thermoplastic matrix were prepared by extrusion method. The fibre content in the composite varied from 0 to 15% w/w. Using X-ray diffraction and scanning electron microscopy, the structure and morphology of the composites have been analysed. This investigation is focused on the effects of the fibre content on the mechanical and thermal properties of the composites. Addition of the waste cotton fibre to the matrix increased the tensile properties. For the composite with 10% w/w of fibre the values of the tensile stress are found maximum. We also show that thermal conductivity and resistivity are not affected by the fibre content. By thermogravimetry we show that the addition of fibres to the matrix has no significant influence on the thermal stability of the composites. Finally, to analyse the efficiency of the present system, a comparative study of the mechanical properties obtained with flax and cotton fibres is performed.     

Antioxidant and gastroprotective actions of butanol fraction of Zingiber officinale against diclofenac sodium‐induced gastric damage in rats

This study was designed to investigate the antioxidant and antiulcer activities of flavonoid‐rich fractions of Zingiber officinale extract. The fractions, obtained by solvents of increasing polarities, were subjected to 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity. The fraction which possessed the highest antioxidant activity was used to assess gastroprotective action against diclofenac sodium induced gastric ulcer in rats. Chromatographic profiling was carried out using LC‐ESI‐MS analysis. The butanol fraction (BF) showed the strongest antioxidant potential and the results of the in vivo study revealed that BF at 100 mg/kg protected against gastric lesions. At the same dose, BF prevented diclofenac sodium‐induced increase in tumor necrosis factor alpha (TNF‐α) and malondialdehyde (MDA) levels, and depletion of catalase (CAT) activity as well as glutathione (GSH) and prostaglandin E2 (PGE2) contents. LC‐ESI‐MS analysis revealed the presence of 12 phenolic compounds. BF exerted antiulcer action which could be linked to the presence of phenolic compounds.

Practical applications

Zingiber officinale has been widely consumed as a spice and used in folk medicine for treatment of gastric disorders. This is the first report evaluating the pharmacological effects of the butanol extract of ginger for the prevention of gastric ulcer. The results showed that the extract affords better gastroprotective activity against diclofenac sodium‐induced gastric ulcer in rats by reducing oxidative stress. Information provided in this study will be beneficial for developing applications of ginger in food biotechnology as functional and nutraceutical ingredient.     

Fabrication and characterization of 100% green composite: Thermoplastic based on wheat flour reinforced by flax fibers

Biocomposites having flax fibers as reinforcement in wheat flour based thermoplastic matrix were prepared by extrusion method. The fiber content of the composites varied from 0% to 20% w/w. The structure and morphology of the fiber and composites prepared were studied using X‐ray diffraction and scanning electron micrograph methods. The mechanical properties such as stress at failure, strain at failure, and tensile modulus were studied as a function of fiber content. The incorporation of fiber to the matrix increased the tensile properties and is maximum for the composite having a fiber loading of 20% w/w. Thermal stability of the fiber and the composite having various fiber content (0, 5, 10, 15, and 20% w/w) was analyzed by thermogravimetric method. There is no significant variation in the thermal stability of the composites. Finally, comparative studies of the mechanical properties were done to evaluate the efficiency of this new system. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers