Role of acidic sphingomyelinase in thymol‐mediated dendritic cell death

Scope : Thymol is a component of several plants with antimicrobial activity. Little is known about the effects of thymol on immune cells of the host. This study addressed the effects of thymol on dendritic cells (DCs), regulators of innate and adaptive immunity. Methods and results : Immunohistochemistry, Western blotting and fluorescence‐activated cell sorting analysis were performed in bone marrow‐derived DCs either from wild‐type mice or from mice lacking acid sphingomyelinase (ASM^?/?) treated and untreated for 24 h with thymol (2–100 μg/mL). Thymol treatment resulted in activation of ASM, stimulation of ceramide formation, downregulation of anti‐apoptotic Bcl‐2 and Bcl‐xL proteins, activation of caspase 3 and caspase 8, DNA fragmentation as well as cell membrane scrambling. The effects were dependent on the presence of ASM and were lacking in ASM^?/? mice or in wild‐type DCs treated with sphingomyelinase inhibitor amitriptyline. Conclusion : Thymol triggers suicidal DC death, an effect mediated by and requiring activation of ASM.     

Software defined vehicular networks: A comprehensive review

The recent breakthroughs in the automobile industries and telecommunication technologies along with the exceptional multimodal mobility services brought focus on intelligent transportation system (ITS), of which vehicular ad hoc networks (VANETs) gain much more attention. The distinctive features of software‐defined networking (SDN) leverages the vehicular networks by its state of the centralized art having a comprehensive view of the network. Its potential to bring the flexibility, programmability and other extensive advancements to vehicular networks has set the stage for a novel networking paradigm termed as software‐defined vehicular networks (SDVNs). Many researchers have demonstrated the SDN‐based VANETs with the various configuration of the SDN components in VANET architecture. However, a compilation of the work on the SDN‐based VANET system as a whole, incorporating its architecture, use‐cases, and opportunities, is still inadequate. We start with the summary of the recent studies that exist on the SDVNs, followed by the comprehensive explanation of its components. Next, we present the taxonomy of SDVN based on the architecture modes, protocols, access technologies, and opportunities with trending technologies. Finally, we highlight the challenges, open research issues, and future research directions.     

Enhancing data delivery with density controlled clustering in wireless sensor networks

Microsystem Technologies - Wireless sensor networks (WSN) are primarily used for sensing and collecting the information from environment. This information is sent to base station (BS), where, it is...     

A New Economical Implementation for Scannable Flip-Flops in MOS

A New implementation for scannable flip-flops in MOS is economical for use in systems that use single latch design. The ?System Latch-Scannable Flop? (SL-SF) requires two additional transfer gates, two test clocks, and possibly a test mode signal. Hardware pernalties paid in SL-SF can be the least among other implementations with equivalent test functionality. This article discusses SL-SF only in the context of its scan-path implementation; its applicability to linear feedback shift-register-based self-test should be obvious.     

Incremental communication for multilayer neural networks

A new method of inter-neuron communication called incremental communication is presented. In the incremental communication method, instead of communicating the whole value of a variable, only the increment or decrement of its previous value is sent on a communication link. The incremental value may be either a fixed-point or a floating-point value. Multilayer feedforward network architecture is used to illustrate the effectiveness of the proposed communication scheme. The method is applied to three different learning problems and the effect of the precision of incremental input-output values of the neurons on the convergence behavior is examined. It is shown through simulation that for some problems even four-bit precision in fixed- and/or floating-point representations is sufficient for the network to converge. With 8-12 bit precisions almost the same results are obtained as that with the conventional communication using 32-bit precision. The proposed method of communication can lead to significant savings in the intercommunication cost for implementations of artificial neural networks on parallel computers as well as the interconnection cost of direct hardware realizations. The method can be incorporated into most of the current learning algorithms in which inter-neuron communications are required. Moreover, it can be used along with the other limited precision strategies for representation of variables suggested in literature.     

Optical bandgap of Sb0.2Bi1.8Te3 thin films

Sb_0.2Bi_1.8Te₃ Thin Films were grown using the thermal evaporation technique on a (001) face of NaCl crystal as a substrate at room temperature. The optical absorption was measured in the wave number range 500 cm^–1 to 4000 cm^–1. From the optical absorption data the bandgap has been evaluated and studied as a function of the film thickness and deposition temperature. The data indicate absorption through direct interband transition with a bandgap around 0.21 eV. The detailed results are reported.     

Stability and Degradation Processes of Pentaerythritol Tetranitrate (PETN) on Metal Oxide Surfaces

The chemical stability of pentaerythritol tetranitrate (PETN) when placed in physical contact with metal oxides is investigated. In this study, PETN was placed on the surfaces of a range of microcrystalline metal oxides including MnO₂, CuO, MoO₃, WO₃, Bi₂O₃, SnO₂, and Fe₂O₃ in coverages of 1–3.5 monolayers by a wet impregnation technique. Samples were then placed in a controlled temperature environment at 50°C and checked periodically for the presence of decomposition products using liquid chromatography. PETN proved to be inert over all of the oxides except MoO₃, which showed the relatively rapid evolution of a brown gas over a period of 48 h. Analysis of the evolved gas indicated that it is primarily NO₂ along with N₂O₄, N₂O, and CO₂.     

Effects of anisotropy and annealing on microhardness of In x Bi2−x Te3 (x=0·1 to 0·5) single crystals

The crystals of In _x Bi_2−x Te₃ (x=0·1 to 0·5) have been grown by zone-melting method. In order to study anisotropy exhibited by the (0001) plane of the crystals, the directional hardness was determined by producing indentations at various azimuthal orientations of the indentor with respect to the surface over a range 0–180°. The crystal was rotated about the indentor axis in steps of 15° while keeping applied load and loading time constant at 50 g and 20 sec, respectively. For annealing study, the sample was kept at a temperature of 375°C. It was observed that softening of crystal takes place and the hardness decreases to a considerable extent.     

Development of a multichemical food web model: application to PBDEs in Lake Ellasjoen, Bear Island, Norway

A multichemical food web model has been developed to estimate the biomagnification of interconverting chemicals in aquatic food webs. We extended a fugacity-based food web model for single chemicals to account for reversible and irreversible biotransformation among a parent chemical and transformation products, by simultaneously solving mass balance equations of the chemicals using a matrix solution. The model can be applied to any number of chemicals and organisms or taxonomic groups in a food web. The model was illustratively applied to four PBDE congeners, BDE-47, -99, -100, and -153, in the food web of Lake Ellasj?en, Bear Island, Norway. In Ellasj?en arctic char (Salvelinus alpinus), the multichemical model estimated PBDE biotransformation from higher to lower brominated congeners and improved the correspondence between estimated and measured concentrations in comparison to estimates from the single-chemical food web model. The underestimation of BDE-47, even after considering bioformation due to biotransformation of the otherthree congeners, suggests its formation from additional biotransformation pathways not considered in this application. The model estimates approximate values for congener-specific biotransformation half-lives of 5.7,0.8,1.14, and 0.45 years for BDE-47, -99, -100, and -153, respectively, in large arctic char (S. alpinus) of Lake Ellasj?en.