Ixodes ricinus Salivary Serpin Iripin-8 Inhibits the Intrinsic Pathway of Coagulation and Complement

Tick saliva is a rich source of antihemostatic, anti-inflammatory, and immunomodulatory molecules that actively help the tick to finish its blood meal. Moreover, these molecules facilitate the transmission of tick-borne pathogens. Here we present the functional and structural characterization of Iripin-8, a salivary serpin from the tick Ixodes ricinus, a European vector of tick-borne encephalitis and Lyme disease. Iripin-8 displayed blood-meal-induced mRNA expression that peaked in nymphs and the salivary glands of adult females. Iripin-8 inhibited multiple proteases involved in blood coagulation and blocked the intrinsic and common pathways of the coagulation cascade in vitro. Moreover, Iripin-8 inhibited erythrocyte lysis by complement, and Iripin-8 knockdown by RNA interference in tick nymphs delayed the feeding time. Finally, we resolved the crystal structure of Iripin-8 at 1.89 Å resolution to reveal an unusually long and rigid reactive center loop that is conserved in several tick species. The P1 Arg residue is held in place distant from the serpin body by a conserved poly-Pro element on the P′ side. Several PEG molecules bind to Iripin-8, including one in a deep cavity, perhaps indicating the presence of a small-molecule binding site. This is the first crystal structure of a tick serpin in the native state, and Iripin-8 is a tick serpin with a conserved reactive center loop that possesses antihemostatic activity that may mediate interference with host innate immunity.     

Determination of Harmonics of Converter Current and/or Voltage Waveforms (New Method for Fourier Coefficient Calculations), Part I: Fourier Coefficients of Homogeneous Functions

A new method of determining Fourier coefficients is described. The advantage of the method is the substitution of algebraic addition to replace the integration operation in Fourier analysis. The method is applicable to every periodic function that satisfies Dirichlet conditions. Several waveforms of converter voltages and currents are analyzed as examples for the method.     

Gas diffusion in multibubble systems

A model is proposed for the study of the growth and shrinkage of gas bubbles in systems containing many gas bubbles. The key feature of this model is the replacement of the bubbles by point sources of gas concentration. Calculations are performed in the simple case of an initial uniform array of bubbles of equal radii.     

High-Speed FPGA Implementation of Secure Hash Algorithm for IPSec and VPN Applications

Hash functions are special cryptographic algorithms, which are applied wherever message integrity and authentication are critical. Implementations of these functions are cryptographic primitives widely used in common cryptographic schemes and security protocols such as Internet Protocol Security (IPSec) and Virtual Private Network (VPN). In this paper, a novel FPGA implementation of the Secure Hash Algorithm 1 (SHA-1) is proposed. The proposed architecture exploits the benefits of pipeline and re-timing of execution through pre-computation of intermediate temporal values. Pipeline allows division of the calculation of the hash value in four discreet stages, corresponding to the four required rounds of the algorithm. Re-timing is based on the decomposition of the SHA-1 expression to separate information dependencies and independencies. This allows pre-computation of intermediate temporal values in parallel to the calculation of other independent values. Exploiting the information dependencies, the fundamental operational block of SHA-1 is modified so that maximum operation frequency is increased by 30% approximately with negligible area penalty compared to other academic and commercial implementations. The proposed SHA-1 hash function was prototyped and verified using a XILINX FPGA device. The implementation’s characteristics are compared to alternative implementations proposed by the academia and the industry, which are available in the international IP market. The proposed implementation achieved a throughput that exceeded 2,5 Gbps, which is the highest among all similar IP cores for the targeted XILINX technology.     

Observations of Lake Baikal ice from satellite altimetry and radiometry

We demonstrate the potential of combining satellite altimetry and radiometry for lake ice studies using the example of Lake Baikal in Siberia. We show the synergy using active and passive microwave observations available from the recent satellite altimetry missions (TOPEX/Poseidon, Jason-1, ENVISAT and Geosat Follow-On), complemented by the SSM/I passive data. We assess the applicability of altimetric and radiometric data for ice/water discrimination, and discuss the drawbacks and benefits of each type of sensor. An ice discrimination method, based on the combined use of the data from the four altimetric missions and SSM/I, is proposed and validated using available in situ observations and MODIS imagery. The method is applied to the entire satellite data set and used to define specific dates of ice events (first appearance of ice, formation of stable ice cover, first appearance of open water, complete disappearance of ice) and associated uncertainties. Using these satellite-derived estimates, we can extend the existing time series of ice events in the Southern Baikal up to 2004 and provide new information on the Middle and Northern Baikal, regions where no recent in situ ice cover observations are available. Our data show that over the last 10-15 years, trends towards earlier ice formation and later ice break-up result in a tendency for longer fast ice duration over the whole Lake Baikal. The methods proposed here have been tested for Lake Baikal, but they are applicable for other lakes and water bodies with seasonal ice cover.     

Energy efficient and perceived QoS aware video routing over Wireless Multimedia Sensor Networks

Wireless Sensor Networks (WSNs) have an ever increasing variety of multimedia based applications. Ιn these types of applications, network nodes should ideally maximize QoS and minimize energy expenditures in video communication. This article presents PEMuR, a novel dual scheme for efficient video communication, which aims at both energy saving and high QoS attainment. To achieve its objectives, PEMuR proposes the combined use of an energy aware hierarchical routing protocol with an intelligent video packet scheduling algorithm. The adopted routing protocol enables the selection of the most energy efficient routing paths, manages the network load according to the energy residues of the nodes and prevents useless data transmissions through the proposed use of an energy threshold. In this way, an outstanding level of energy efficiency is achieved. Additionally, the proposed packet scheduling algorithm enables the reduction of the video transmission rate with the minimum possible increase of distortion. In order to do so, it makes use of an analytical distortion prediction model that can accurately predict the resulted video distortion due to any error pattern. Thus, the algorithm may cope with limited available channel bandwidth by selectively dropping less significant packets prior to their transmission. Simulation results demonstrate the effectiveness of the proposed scheme.     

Detonation Spraying of Ti–Al Intermetallics: Phase and Microstructure Development of the Coatings

The goal of this work was to study the phase and microstructure changes involved in the process of coating formation by detonation spraying of Ti₃Al, TiAl, and TiAl₃ intermetallics. The O₂/C₂H₂ ratio was varied between 1.1 and 2.0, and the explosive charge was 30–40% of the barrel volume. In most experiments air was used as a carrier gas; selected experiments were performed with argon. We found that depending on the spraying parameters, TiAl₃ essentially retains in the coatings or partially decomposes forming TiAl and Ti₃Al as minor phases. Detonation sprayed Ti₃Al reacts with nitrogen and oxygen partially transforming into titanium nitrides TiN/Ti₂N and titanium oxynitrides TiN_xO_y. TiAl partially decomposes forming Ti₃Al, which further reacts with oxygen and nitrogen as the particle temperature and the content of oxygen in the explosive mixture increase. The in situ formed titanium nitrides and oxynitrides show a reinforcing effect increasing the hardness of the coatings.     

Synthesis of the first hyperbranched polyorganoethoxysilsesquioxanes and their chemical transformations to functional core–shell nanogel systems

Hyperbranched polyvinyl‐ and polymethylethoxysiloxanes were obtained for the first time by heterofunctional polycondensation of the corresponding organoethoxysilanols derived from relevant monosodium organodiethoxysilanolates. Synthesized structures were characterized using ²⁹Si NMR, ¹H NMR and infrared spectroscopies, gel permeation chromatography and elemental analysis. On the basis of the obtained hyperbranched polyorganoethoxysiloxanes, new ‘core–shell’ structured polyvinyl‐ and polymethylsilsesquioxanes with adjustable sizes, different crosslinking densities and variable chemical natures of the core–shell surroundings were prepared, investigated and characterized using ¹H NMR and infrared spectroscopies, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry and elemental analysis. © 2015 Society of Chemical Industry     

The effect of cognitive workload on decision authority assignment in human–robot collaboration

Cognition, Technology & Work - Human–robot collaboration in dynamic industrial environments warrants robot flexibility and shifting between tasks. Adaptive robot behavior unavoidably...