Molecular architecture and biophysical properties of phospholipids during thermal adaptation in fish: An experimental and model study

Phospholipids from livers of carps (Cyprinus carpio L.) adapted to winter (5°C) and summer (25°C) temperatures were isolated, and the fatty acid composition of total phospholipids, as well as molecular species composition of diacyl phosphatidylcholines and ethanolamines, were determined. Order parameter of 5-doxyl stearic acid and steady-state fluorescence anisotropy of different anthroyloxy fatty acids—[2-, 12(N-9-anthroyloxy)stearic acid and 16(N-9-anthroyloxy)palmitic acid—embedded in native and synthetic (16∶0/16∶0, 16∶0/22∶6, 18∶0/22∶6, 18∶1/22∶6, 20∶4/20∶4, 22∶6/22∶6 phosphatidylcholines and 16∶0/18∶1, 18∶1/22∶6 phosphatidylethanolamines) phospholipid vesicles was also determined between −30 and 30°C and 5 and 30°C, respectively. There is an accumulation of 1-monoenoic, 2-polyenoic diacyl phosphatidylcholine and ethanolamine with a concomitant reduction of 1-stearoyl,2-docosahexaenoyl species in the cold-adapted state. Despite a 30% accumulation of long-chain polyunsaturated fatty acids in phospholipids in cold, there is only a 5°C downshift in the solid-gel to liquid-crystalline phase transition temperature (−8 vs. −13°C). Vesicles from total phospholipids of cold-adapted fish proved to be more disordered in all segments than from the warmadapted ones when assayed using 2,12-(N-9-anthroyloxy)stearic and 16-(N-9-anthroyloxy)palmitic acid. Vesicles made from purified phosphatidylcholines showed the same pattern, but they were more disordered than the corresponding total phospholipids. This could be modelled using mixed phospholipid vesicles made of synthetic 16∶0/22∶6 phosphatidylcholine (75%) and either 18∶1/22∶6 phosphatidylethanolamine (25%) vs. 16∶0/18∶1 phosphatidylethanolamine (25%) and comparison of the anisotropy parameters of 100% 16∶0/22∶6 and 100% 18∶1/22∶6 phosphatidylcholine vesicles. Mixing either 16∶0/18∶1 (25%) or 18∶1/22∶6 (25%) phosphatidylethanolamines to 18∶0/22∶6 (75%) phosphatidylcholine shifted down or up, respectively, the transition temperature of vesicles compared to 100% 18∶0/22∶6 vesicles assayed by electron spin resonance spectroscopy using 5-doxylstearic acid. It is concluded that it is not the gross amount of long-chain polyunsaturated fatty acids in phospholipids, but rather their specific combination withcis Δ9 monounsaturated fatty acids in the positionsn-1, especially in phosphatidylethanolamines, that is important in determining the physical properties of biomembranes in relation to adaptational temperature.     

Soft computing based imputation and hybrid data and text mining: The case of predicting the severity of phishing alerts

In this paper, we employ a novel two-stage soft computing approach for data imputation to assess the severity of phishing attacks. The imputation method involves K-means algorithm and multilayer perceptron (MLP) working in tandem. The hybrid is applied to replace the missing values of financial data which is used for predicting the severity of phishing attacks in financial firms. After imputing the missing values, we mine the financial data related to the firms along with the structured form of the textual data using multilayer perceptron (MLP), probabilistic neural network (PNN) and decision trees (DT) separately. Of particular significance is the overall classification accuracy of 81.80%, 82.58%, and 82.19% obtained using MLP, PNN, and DT respectively. It is observed that the present results outperform those of prior research. The overall classification accuracies for the three risk levels of phishing attacks using the classifiers MLP, PNN, and DT are also superior.     

Toward a theory to study the use of collaborative product commerce for product development

Collaborative product commerce (CPC) solutions span software and services which permit individuals to share product data to improve the design, development, and management of products throughout the product development lifecycle. Drawing upon prior developments in adaptive structuration theory (AST) and media richness theory, I develop a theoretical framework to better understand the role of CPC in enabling collaboration in a product development environment. I study the impact of CPC on product design and development processes using a cross-sectional survey of 36 firms. The study reveals that CPC usage varies across different phases of the product development lifecycle. Preliminary results indicate that CPC has enabled firms to collaborate effectively with external stakeholders, which has resulted in tangible business benefits. I conclude by developing several research propositions which provide a roadmap for conducting future empirical research to measure the impact of CPC on product development, and highlight potential research topics that can be explored.

An adaptive audio watermarking based on the singular value decomposition in the wavelet domain

This paper presents a secure, robust, and blind adaptive audio watermarking algorithm based on singular value decomposition (SVD) in the discrete wavelet transform domain using synchronization code. In our algorithm, a watermark is embedded by applying a quantization-index-modulation process on the singular values in the SVD of the wavelet domain blocks. The watermarked signal is perceptually similar to the original audio signal and gives high quality output. Experimental results show that the hidden watermark data is robust to additive noise, resampling, low-pass filtering, requantization, MP3 compression, cropping, echo addition, and denoising. Performance analysis of the proposed scheme shows low error probability rates. The data embedding rate of the proposed scheme is 45.9 bps. The proposed scheme has high payload and superior performance against MP3 compression compared to the earlier audio watermarking schemes.     

Does sampling influence customers in online retailing of digital music?

Online retailers have taken recourse to many smart marketing strategies to sell digital music. This paper investigates the strategic decisions of online vendors for offering different mechanisms such as sampling and online reviews of digital music to increase their online sales. In this research we seek answers to the following research questions (1) should online retailers offer sampling for experience goods such as music CDs; (2) under what circumstances is offering sampling more important than offering reviews. Our empirical study shows that online markets behave as communication markets, and consumers learn about product quality information both passively (by reading online reviews) and actively but subjectively (by listening to music sampling). Using data from , we empirically show that sampling is a strong product quality signal that reduces product uncertainty and attracts interested shoppers. Products with the sampling option enjoy a higher conversion rate (which leads to better sales) than those without it. Second, the impact of online reviews on conversion rate is lower for experience goods with a sampling option than those without. Third, when the uncertainty of the online reviews is higher, sampling plays a more important role because it mitigates the uncertainty introduced by online reviews. We believe this paper makes an important contribution by comparing and studying the interactions between two commonly adopted online marketing strategies (i.e., sampling versus online reviews) and provides important insights on which strategy is beneficial for vendors in the context of online selling of digital music.     

Conceptual design analysis of a compressor‐driven sorption cooling system

The feasibility of using activated carbon/nitrogen pair as an alternative to metal hydride–hydrogen combination in a compressor‐driven sorption refrigerator (CDSR) has been studied in the present article. The motivation behind the selection of this particular adsorbent/adsorbate pair is due to its high heat of adsorption/desorption, in addition to the fact that nitrogen is absolutely eco‐friendly and a nonhazardous gas to handle with. A conceptual design of the cooling system has been envisaged for near room temperature applications with this activated carbon/nitrogen pair. In order to evaluate the performance of the CDSR system, mathematical models have been developed separately for the adsorption and desorption processes involving transient heat and mass transfer analysis. The present analysis also helped to conduct a parametric evaluation of the cooling system. Copyright © 2009 John Wiley & Sons, Ltd.     

Design of Optimum Zeolite Pore System for Central Hydrocracking of Long-Chain <Emphasis Type="Italic">n</Emphasis>-Alkanes based on a Single-Event Microkinetic Model

Model based catalyst design is an emerging methodology in the development of new catalytic materials with properties tailored to the needs of specific industrial applications. A Single-Event MicroKinetic model (SEMK) was used to assess the hydrocracking behavior of n-dodecane, 4,4,6-trimethyl nonane and 2,5,8-trimethyl nonane, on a non-selective USY zeolite. The differences in cracking pattern exhibited by the various feed molecules provide guidelines for the control of the cracked product distribution through modifications of the zeolite pore structure. The connection of ZSM-22 type channels to the zeolite Y super cage is considered in this work. The percentage of C₆ products obtained by central cracking in the chain can be increased from 25% up to 93% by the design of an appropriate zeolite topology combining USY-like super cages with ZSM-22 like channel segments. This is a promising approach for the development of zeolite catalysts for the selective hydrocracking of Fischer Tropsch waxes into middle distillates.     

AVMON: Optimal and Scalable Discovery of Consistent Availability Monitoring Overlays for Distributed Systems

This paper proposes to build overlays that help in monitoring of long-term availability histories of hosts, with a focus on large-scale distributed settings where hosts may be selfish or colluding. Concretely, we target the important problems of selection and discovery of an availability monitoring overlay. We motivate six significant goals - firstly, consistency, verifiability, and randomness, in selecting availability monitors of nodes, so as to be probabilistically resilient to selfish and colluding nodes. The next three goals are discoverability, load-balancing, and scalability in finding these monitors. We present AVMON, the first availability monitoring overlay to satisfy these six requirements. Our core algorithmic contribution is a range of protocols for discovering the availability monitoring overlay scalably and efficiently, given any arbitrary monitor selection scheme that is consistent and verifiable. We mathematically analyze the performance of AVMON's discovery protocols w.r.t. scalability and discovery time of monitors. Most interestingly, we are able to derive optimal (and practical) variants of AVMON, that minimize different combinations of memory, bandwidth, computation, and monitor discovery time. Finally, our extensive experimental evaluations using three types of availability traces - synthetic, from PlanetLab, and from the Overnet p2p system - demonstrate AVMON's practicality in a variety of distributed systems.     

Synthesis,characterization, and thermal property measurement of nano-Al95Zn05 dispersed nanofluid prepared by a two-step process

Nanofluids are stable suspension of nanometer sized particles and exhibit extremely attractive thermal properties that make them a potential candidate for application in heat transfer devices ranging from microelectronic gadgets to thermal power plants. In the present study, we have synthesized Al-5wt%Zn nanoparticles by mechanical alloying, characterized these nanoparticles using X-ray diffraction and scanning and transmission electron microscopy. Subsequently, these nanoparticles are dispersed to the tune of 0.01–0.10 vol% in ethylene glycol (base fluid) following a careful mixing protocol. Thermal conductivity of the nanofluids and base fluid has been measured using the transient hot-wire method. It is observed that thermal conductivity of the nanofluids strongly depend on the concentration, particle size, fluid temperature and stability of dispersed nanoparticles in the base fluid. A maximum of 16% enhancement in thermal conductivity has been recorded at a nanoparticle loading of 0.10 vol%. Unlike data reported in some articles, thermal conductivity ratio of Al-5wt%Zn dispersed ethylene glycol based nanofluids is observed to decrease with the increase in crystallite/grain size of the particles.