Network traffic analysis using singular value decomposition and multiscale transforms

The present work integrates the multiscale transform provided by the wavelets and singular value decomposition (SVD) for the detection of anomaly in self-similar network data. The algorithm proposed in this paper uses the properties of singular value decomposition (SVD) of a matrix whose elements are local energies of wavelet coefficients at different scales. Unlike existing techniques, our method determines both the presence (i.e., the time intervals in which anomaly occurs) and the nature of anomaly (i.e., anomaly of bursty type, long or short duration, etc.) in network data. It uses the diagonal, left and right singular matrices obtained in SVD to determine the number of scales of self-similarity, location and scales of anomaly in data, respectively. Our simulation work on different data sets demonstrates that the method performs better than the existing anomaly detection methods proposed for self-similar data.     

Association of stereoregular poly(methyl methacrylates): 2. Formation of stereocomplex in bulk

Blends of isotactic and syndiotactic poly(methyl methacrylate) (i- and s-PMMA) are obtained by precipitation from chloroform and acetone solutions. By differential scanning calorimetry and dynamicmechanical measurements the formation of stereocomplexes from i- and s-PMMA in bulk is demonstrated. After annealing of the blends at 130–160°C a melting endotherm is detected and it is established by X-ray analysis that this endotherm is caused by formation of crystalline stereocomplex. The rate of complex formation is maximal at 140°C and the extent of complex formation is maximal at an isotactic-rich composition. It appears that the difference in solvent history can be removed by heating to 240°C. The subsequent S-shaped course of glass transition temperature, T_g, with composition is explained by the occurrence of some complex formation during cooling from 240°C. Asymmetry and shift of the dynamic-mechanical damping curves after annealing are also explained by the formation of complexes. A mechanism is proposed with helical isotactic chains acting as nuclei for a fringed micelle type of complex formation.     

Crystallization and melt behaviour of isotactic poly(2-vinylpyridine)

The crystallization and melting behaviour of highly isotactic poly(2-vinylpyridine) (it-P2VP) with $\text{M}\text{?}{}_{\mathrm{<mtext>v</mtext>}}\text{= 4 × 10}{}^5$ has been studied by microscopy and d.s.c.. The maximum spherulitic growth rate was found to be 250 × 10^?3μm/min at a crystallization temperature T_c of 165°C. Experimental data could be described by the growth rate theory for small supercooling, by taking the appropriate value of 75 for the constant c₂ of the WLF equation. The chain-folded surface free energy σ_e, was estimated at 39.5 × 10^?3 J m^?2. The melting curves showed 1,2 or 3 melting endotherms. At large supercooling, crystallization from the melt produced a small melting endotherm just above T_c. This peak may originate from secondary crystallization of melt trapped within the spherulites. The next melting endotherm is related to the normal primary crystallization process. Its peak temperature increased linearly with T_c, yielding an extrapolated value for the equilibrium melting temperature T°_m of 212.5°C. At the normal values of T_c and heating rate a third endotherm appeared with a peak temperature that was independent of T_c, but rose with decreasing heating rate. From the effects of heating rate and partial scanning on the ratio of peak areas, it is concluded that this peak arises from secondary crystallization by continuous melting and recrystallization during the scan. This crystallization and melting behaviour of it-P2VP is very similar to that of isotactic polystyrene.     

White‐Emitting Protein Nanoparticles for Cell‐Entry and pH Sensing

Facile synthesis of white‐emitting, protein‐based, metal‐free, stable, nontoxic, and pH sensitive, advanced functional nanoparticles (GlowDots), as alternatives to quantum dots, is reported here. Controlled cross‐linking of bovine serum albumin resulted in facile formation of spherical nanoparticles of 35 nm in diameter with a sharp size distribution (±10 nm), which were then conjugated with specific dyes to produce white‐emitting particles with tunable excitation wavelengths. Chemical novelty is that the particle size, size distribution, stability, surface chemistry, and emission properties are under full chemical control where the size and absorption/emission properties are independently tuned. Up to 100 dye molecules were attached to each particle, on an average, and hence, particles acquired strong absorption cross‐sections as well as high brightness. White fluorescence of GlowDots is strongly sensitive to pH over a range of pH 2–11, and pH‐induced emission changes are fully reversible. The particles readily entered HeLa cells and emission color depended on particle location in the live cells, which is most likely due to the local environment surrounding the particles. These are the very first reports of white‐emitting advanced functional nanoparticles that are biodegradable, sensitive to pH, and amenable for live cell imaging to probe the subcellular compartments.     

Dye doped sulphamic acid crystals: a potential material for optoelectronic applications

Journal of Materials Science: Materials in Electronics - This is the first study to look at how organic dyes Reactive Orange 16 (RO 16) and Safranin affects the optical and thermal characteristics...     

Automation of dietary fibre (TDF,IDF and SDF) analysis by ANKOMTDF analyzer for enzymatic‐gravimetric process

In this work, we evaluated the effectiveness of the automation capability offered by the ANKOM^TDF Dietary Fibre Analyzer to automate the current manual practice of fibre analysis (AOAC Method 991.43). Further, we also validated the automated fibre analysis via cross‐checking with fibre analysis by the manual operation using fruit‐, grain‐ and nut‐based samples. Automated fibre analysis showed relative standard deviations (TDF: 13.8%; IDF: 17.2%; and SDF: 24.6% at 95% CI reported by the AOAC in the method 991.43) that are consistent to the manual methods. Thus, this current work serves as a valuable assessment of a novel filtration system with disposable filter bag developed by ANKOM Technology. The new instrumentation automates the enzymatic‐gravimetric processing by eliminating several laborious, time‐consuming manual operations, saving over 50% of analyst time that converts to 60% overall cost savings and improved laboratory productivity, efficiency and safety. Industry‐wide adoption of such instrumentation not only reduces the analysis cost but also harmonises the fibre amounts reported among the global food and beverage industry.     

Total Phenol Content,Antioxidant Activities and α‐Glucosidase Inhibition of Sesame Cake Extracts

Sesame cake, the byproduct obtained after the removal of oil is presently used as cattle field. Present study evaluates the α‐glucosidase, α‐amylase inhibition and antioxidant properties of black sesame cake extracts. For that purpose, defatted seeds were sequentially extracted with ethyl acetate, methanol, methanol‐water 70:30 (v/v) and water. Among the extracts tested, methanol extract demonstrated better antioxidant activities (2,2‐diphenyl‐1‐picrylhydrazyl, hydroxyl and superoxide radical) and total phenol content. But the total flavonoid content and the total reducing power was high for methanol‐water. Most active methanol extract was further screened for α‐glucosidase and α‐amylase inhibition. The extract showed strong α‐glucosidase inhibitory potential and mild α‐amylase inhibition. The study indicated that the extraction yield and the antioxidant activities were strongly dependent on the solvent, antioxidant assays and extract concentration. These results demonstrated that sesame meal can be exploited as source of protein and bioactive for the development of functional food.     

Ultrathin film assembly of sulfobetaine-stabilized palladium nanoparticles investigated by photoemission spectroscopy

Thin films of sulfobetaine-stabilized palladium nanoparticles on a gold surface were prepared by evaporation of their colloidal water solution and investigated by ultraviolet photoemission spectroscopy. The photoemission from the thin films was found to be dominated entirely by the surfactant molecules. No photoemission from the gold substrate was observed; these facts strongly suggest the formation of uniform (hole-free) thin films of the surfactant-stabilized nanoparticles. Additional investigation of structural degradation using neon-ion sputtering also supports the film condition.     

The histological effect of barrier vein wrapping of peripheral nerves

Twenty-four Sprague-Dawley rats underwent exploration and exposure of the sciatic nerve, followed by sham isolation, irrigation, and subsequent wound closure (Group 1); barrier vein wrapping of the nerve using glutaraldehyde-preserved allograft inferior vena cava (Group 2); or barrier vein wrapping of the nerve with femoral vein autograft from the contralateral extremity (Group 3). Four months later, the rats were sacrificed and the nerves fixed in situ in buffered glutaraldehyde. Sections proximal, mid-portion, and distal to the barrier and vein wrap were fixed with osmium tetroxide, epon embedded, stained with toluidine blue, and studied under x200 and x400 light microscopy. Epineural scar formation increased 10 times in Group 2, compared to Group 3 (p < 0.0001). Epineural thickness and the number of degenerating axons did not differ significantly among all groups. Inflammatory cells in Group 2 increased 100 times, compared to Group 3 (p < 0.0001). Continuing with the underlying epineural layer was apparent grossly and microscopically with all allografts, but with no autografts. Thus, glutaraldehyde-preserved allograft vein wraps appear to incite a marked inflammatory response, with epineural scarring and adherence to the underlying nerve, while autograft vein wraps do not.