FIPA‐based reference architecture for efficient discovery and selection of appropriate cloud service using cloud ontology

Cloud computing is considered the latest emerging computing paradigm and has brought revolutionary changes in computing technology. With the advancement in this field, the number of cloud users and service providers is increasing continuously with more diversified services. Consequently, the selection of appropriate cloud service has become a difficult task for a new cloud customer. In case of inappropriate selection of a cloud services, a cloud customer may face the vendor locked‐in issue and data portability and interoperability problems. These are the major obstacles in the adoption of cloud services. To avoid these complexities, a cloud customer needs to select an appropriate cloud service at the initial stage of the migration to the cloud. Many researches have been proposed to overcome the issues, but problems still exist in intercommunication standards among clouds and vendor locked‐in issues. This research proposed an IEEE multiagent Foundation for Intelligent Physical Agent (FIPA) compliance multiagent reference architecture for cloud discovery and selection using cloud ontology. The proposed approach will mitigate the prevailing vendor locked‐in issue and also alleviate the portability and interoperability problems in cloud computing. To evaluate the proposed reference architecture and compare it with the state‐of‐the‐art approaches, several experiments have been performed by utilizing the commonly used performance measures. Analysis indicates that the proposed approach enables significant improvements in cloud service discovery and selection in terms of search efficiency, execution, and response time.     

A Locally Adaptive Multimode Photodetector Circuit

Photodetection circuits form the first stage of the artificial image acquisition process. The image acquisition circuits discussed in this paper pertain to circuits fabricated in a standard CMOS process. Such circuits offers advantages such as random access to a pixel, faster readout, integration of processing circuitry on the same die, low voltage and low power dissipation, and lower cost over the conventional Charge Coupled Device (CCD) process. We describe a new locally adaptive multimode photodetector circuit. The advantages of the circuit are local adaptation, wide dynamic range, excellent sensitivity, and large output voltage swing. The circuit was fabricated in the 2 CMOS process through MOSIS. Simulation and experimental results of the circuit are given.     

Cation–π Interactions Contribute to Substrate Recognition in γ‐Butyrobetaine Hydroxylase Catalysis

γ‐Butyrobetaine hydroxylase (BBOX) is a non‐heme Fe^II‐ and 2‐oxoglutarate‐dependent oxygenase that catalyzes the stereoselective hydroxylation of an unactivated C?H bond of γ‐butyrobetaine (γBB) in the final step of carnitine biosynthesis. BBOX contains an aromatic cage for the recognition of the positively charged trimethylammonium group of the γBB substrate. Enzyme binding and kinetic analyses on substrate analogues with P and As substituting for N in the trimethylammonium group show that the analogues are good BBOX substrates, which follow the efficiency trend N⁺>P⁺>As⁺. The results reveal that an uncharged carbon analogue of γBB is not a BBOX substrate, thus highlighting the importance of the energetically favorable cation–π interactions in productive substrate recognition.     

Construction of a Bifunctional Pd(0)-CALB@SiO2 Hybrid Catalyst for the Synthesis and Arylation of Imidazo[1,2-a]pyridine in One Pot

Herein, we describe an efficient strategy for the construction of enzyme-metal biohybrid catalyst [Pd(0)-CALB@SiO₂] via encapsulation of Candida antarctica lipase B and Pd(0) within silica. Next, the applicability of the newly constructed biohybrid was demonstrated by catalyzing the sequence of Groebke-Blackburn-Bienayme (GBB) multicomponent reaction and Suzuki-Miyaura coupling in a single-pot to produce clinically significant imidazo[1,2-a]pyridine derivatives. Interestingly, both entities, i.e., CALB enzyme and Pd(0)-metal of hybrid catalyst, exhibited good catalytic activity during this approach. Further, the generality of this protocol was explored by using differently substituted boronic acid, which gave related products in 49–87 % isolated yield. Next, the synthetic utility was proved by set-up a gram scale reaction which provided the complementary product in 81 % yield. Also, the developed biohybrid was found to be reusable up to five catalytic cycles.     

Analysis and Stability Study of Octyl Nicotinate in Aqueous Solutions and Skin Homogenate by LC

Octyl nicotinate is an ester prodrug which is under development for delivery of nicotinic acid to skin for treatment and prevention of dermatological conditions that involve skin barrier impairment such as chronic photodamage and atopic dermatitis or for mitigating skin barrier impairment that results from therapy such as retinoids or steroids. We report here an isocratic RF-LC method with water/acetonitrile (10:90, v/v) as a mobile phase, for the rapid analysis of octyl nicotinate in aqueous solutions. The method was validated in terms of linearity, precision, accuracy and mean recovery of octyl nicotinate from skin homogenate ranging from 98.8 to 102.6%. Separation and quantification of amounts as low as 0.25 μg mL^?1 octyl nicotinate was accomplished. The kinetic of degradation of octyl nicotinate in aqueous solution at 310, 333, 343, and 353 K was studied. The hydrolysis rate constants for degradation of octyl nicotinate in phosphate buffer and skin homogenate were reported. This method will be effective for routine analysis of octyl nicotinate stability in different formulations in future studies.     

Column chromatographic separation of metal ions on 1-(2-pyridylazo)-2-napthol modified amberlite IR-120 resin

Cation exchange resin, Amberlite IR-120, has been modified by the sorption of 1-(2-pyridylazo)-2-napthol (PAN) at pH 6.0. The optimum conditions for the sorption of PAN on the resin have been established. The maximum sorption of PAN was found to be 8.70 micromol/g. In order to explore the separation possibilities of the material, distribution coefficients of a number of metal ions were determined in various solvent systems. A number of binary separations of metal ions of analytical interest have been carried out using columns packed with this material. In order to demonstrate the practical utility of this material, Zn2+ and Hg2+ have been selectively separated from synthetic mixtures of metal ions and assay of Zn2+ and Fe2+ in commercially available pharmaceutical tablets; namely Fesofor-Z and FE-Z, was carried out.     

A Novel Protocol for Security of Location Based Services in Multi-agent Systems

Wireless Personal Communications - Multi-agent systems are automated form of software technology to enhance many applications in our life. However, this technology does not come along with embedded...     

Design of interfaces between high speed data converters and high performance FPGAs for software defined radio applications

Telecommunication Systems - Software defined radio (SDR) is a vast and emerging field that requires the design of various technologies such as antenna, RF, IF, and digital baseband subsystems....     

Innovative Citizen’s Services through Public Cloud in Pakistan: User’s Privacy Concerns and Impacts on Adoption

Mobile Networks and Applications - The world is going to be more and more digital with effective utilization of information and communication technologies in government services to provide services...     

ESOT: a new privacy model for preserving location privacy in Internet of Things

The Internet of Things (IoT) means connecting everything with every other thing through the Internet. In IoT, millions of devices communicate to exchange data and information with each other. During communication, security and privacy issues arise which need to be addressed. To protect information about users’ location, an efficient technique should be devised. Several techniques have already been proposed for preserving location privacy in IoT. However, the existing research lags in preserving location privacy in IoT and has highlighted several issues such as being specific or being restricted to a certain location. In this paper, we propose a new location privacy technique called the enhanced semantic obfuscation technique (ESOT) to preserve the location information of a user. Experimental results show that ESOT achieves improved location privacy and service utility when compared with a well-known existing approach, the semantic obfuscation technique.