bluuebunny/crossref_metadata_2025 huggingface dataset:
The origin of galactic cosmic rays
Authors: Amato Elena
Published: May 2014

Initial discovery of Cosmic Rays (CRs) dates back to a century ago (1912). Their identification as particles rather than radiation dates to about 20 years later and in 20 more years also the first suggestion that they were associated with SNRs was in place. The basic mechanism behind their acceleration was suggested almost 40 years ago. Much work has been done since then with regard to the aim of proving that both the acceleration mechanism and site are well-understood, but no definite proof has been obtained: in spite of impressive progress of both theory and observations, the evidence in support of the commonly accepted interpretation is only circumstantial. In the following, I will try to make the point on where we stand in terms of how our theories confront with data. I will review recent progress on the subject and try pointing the avenues to pursue in order to gather new proofs, if not a smoking gun evidence of the origin of Galactic CRs.
Recommending Talks at Research Conferences Using Users' Social Networks
Authors: Lee Danielle , Brusilovsky Peter
Published: May 2014

This paper investigates recommendation algorithms to suggest talks of interest to attendees of research conferences. In this study, based on a social conference support system Conference Navigator 3 (CN3), we explored three kinds of knowledge sources to generate recommendations: users' preference about talks (CN3 bookmarks), users' social networks (research collaboration network and CN3 following network) and talk content information (titles and abstracts). Using these sources, we explored a diverse set of algorithms from non-personalized community vote-based recommendations and conventional collaborative filtering recommendations to hybrid recommendations such as social network-based (SN) recommendations boosted by content information of talks. We found that SN recommendations fused with content information outperformed the other approaches. Moreover, for cold-start users who have an insufficient number of bookmarks to express their preferences, the recommendations based on their social connections also generated significantly better suggestions than the other approaches. Between two kinds of social networks that we considered as foundations of recommendations, there was no significant difference in the quality of the recommendations.
Effects of Locally Distributed Kelvin–Voigt Damping on Parametric Instability of Timoshenko Beams
Authors: Chen Wei-Ren , Chen Chun-Sheng
Published: May 2014

The effect of partially distributed internal damping of the Kelvin–Voigt type on the parametric instability of a Timoshenko beam subjected to periodic axial loads is studied. To model the dynamic behavior of the beam, a coupled set of second-order linear ordinary differential equations with periodic coefficients is established by the finite element method. A quadratic eigenvalue equation is derived for a parametrically excited damped system to determine the instability regions of the beam of concern based on Bolotin's method. The effects of internal damping, size and location of the damped segment, ratio of thickness to length and static load factor on the parametric instability of the beam are studied, along with the stabilizing effect of the Kelvin–Voigt damping on the primary parametric resonance presented. The results reveal that the beam with a larger damped segment positioned near the fixed end is dynamically more stable.
Validation of Dispersion Curve Reconstruction Techniques for the A0 and S0 Modes of Lamb Waves
Authors: Draudvilienė Lina , Raišutis Renaldas , Žukauskas Egidijus , Jankauskas Audrius
Published: May 2014

The properties of ultrasonic Lamb waves, such as relatively small attenuation and high sensitivity to structural changes of the object being investigated, allow performing of non-destructive testing of various elongated structures like pipes, cables, etc. Due to the dispersion effect of Lamb waves, a waveform of the received informative signal is usually distorted, elongated and overlapping in the time domain. Therefore, in order to investigate objects using the ultrasonic Lamb waves and to reconstruct the dispersion curves, it is necessary to know the relationship between frequency, phase and group velocities and thickness of the plate. The zero-crossing technique for measurement of phase velocity of Lamb waves (the A0 and S0 modes) has been investigated using modelled dispersed signals and experimental signals obtained for an aluminium plate having thickness of 2 mm. A comparison between two reconstruction methods of Lamb wave phase velocity dispersion curves, namely, the two-dimensional fast Fourier transform (2D-FFT) and zero-crossing technique, along with the theoretical (analytical) dispersion curves is presented. The results indicate that the proposed zero-crossing method is suitable for use in reconstruction of dispersion curves in the regions affected by strong dispersion, especially for the A0 mode.
Quantum chemistry studies of meta-tetra(hydroxyphenyl)chlorin (mTHPC) and its isomers
Authors: de Oliveira Osmair Vital , Pires José Maria
Published: May 2014

Quantum chemistry methods were used to study the meta-tetra(hydroxyphenyl)chlorin (mTHPC) and its isomers. The mTHPC (Foscan®) is a commercial chlorin, used in photodynamic therapy (PDT) and is classified as a second-generation drug in PDT. The present work is to obtain quantum chemistry properties which can explain the high efficiency of the mTHPC compared with its isomers (ortho and para) and other chlorins. Based in the chemical hardness and ionization potential obtained from HOMO and LUMO orbitals energy, our results show that all chlorins have similar reactivity. Moreover, all chlorins have approximately the same capacity to storage energy in the triplet excited state, with energy differences between the ground state and the triplet excited state of 1.38, 1.39 and 1.36 eV for oTHPC, mTHPC and pTHPC, respectively. The calculated UV spectra (a very important quantity which can be correlated with the photosensitizer (PS) efficiency property), shows that the present chlorins all have a peak at 622 nm. Finally, after analysis of the dipole moment differences, between the three isomers, an explanation about the greater mTHPC efficiency in PDT, was possible. Due to its greater lipophilic character, mTHPC is absorbed by tumor cells to a greater degree than oTHPC and pTHPC. Our findings are consistent with literature and can be used to help new drug design for use in PDT.
QUALITY AND OUTCOMES: A CRITICAL REVIEW OF STRATEGIC ENVIRONMENTAL ASSESSMENT IN BRAZIL
Authors: MARGATO VÍTOR , SÁNCHEZ LUIS E.
Published: May 2014

In a context of unregulated practice, strategic environmental assessment (SEA) contribution to environmentally sound decision-making may be difficult to gauge. Recent Brazilian experience, where there is no legal requirement for SEA, was studied by reviewing cases selected by considering distinctive drivers for undertaking an assessment, varied locations and different consultancies hired to prepare the report. A quality review checklist was used to evaluate the contents of SEA reports according to: (i) adherence to good practice; (ii) technical quality and adequacy to decision-making processes; (iii) achievement of sound and enduring environmental benefits. Interviews aimed at gauging their actual influence. SEAs reached a relatively high level of technical quality and procedural effectiveness, but very low substantive effectiveness. Influence on decision-making varied from null to limited consideration of information in developing programs. The main challenge for SEA in unregulated contexts is to demonstrate its value to decision-makers and citizens' organisations.
New Perspectives
Authors: Cohen Nathan
Published: May 2014

This paper outlines the context for and describes processes used in the incorporation of RPT technologies within recent interactive artwork and art installations, relating to interdisciplinary research in collaboration with Tachi Lab, Japan.
The Effect of Vibrotactile Stimulation on the Emotional Response to Horror Films
Authors: Branje Carmen , Nespoil Gabe , Russo Frank , Fels Deborah I.
Published: May 2014

Over the last decade consumers have witnessed a dramatic increase in the use of low fidelity, discrete vibrotactile feedback to enhance or replace audio stimuli in entertainment systems. However, use of high-resolution continuous vibrotactile displays remains quite uncommon. The Emoti-Chair is a high-resolution continuous vibrotactile display that may be driven by any type of audio signal, and is purported to convey the emotional properties of sound through organized vibrotactile stimulation. In the current study, we examined the ability of the Emoti-Chair to convey the emotional content of the soundtrack in a horror film. Increases in skin conductance levels were observed when vibrotactile stimuli were added to audio/visual film content. These results provide evidence that users can augment the communication of emotion in film through use of a high-resolution continuous vibrotactile display.
A Survey of Digital Map Processing Techniques
Authors: Chiang Yao-Yi , Leyk Stefan , Knoblock Craig A.
Published: May 2014

Maps depict natural and human-induced changes on earth at a fine resolution for large areas and over long periods of time. In addition, maps—especially historical maps—are often the only information source about the earth as surveyed using geodetic techniques. In order to preserve these unique documents, increasing numbers of digital map archives have been established, driven by advances in software and hardware technologies. Since the early 1980s, researchers from a variety of disciplines, including computer science and geography, have been working on computational methods for the extraction and recognition of geographic features from archived images of maps (digital map processing). The typical result from map processing is geographic information that can be used in spatial and spatiotemporal analyses in a Geographic Information System environment, which benefits numerous research fields in the spatial, social, environmental, and health sciences. However, map processing literature is spread across a broad range of disciplines in which maps are included as a special type of image. This article presents an overview of existing map processing techniques, with the goal of bringing together the past and current research efforts in this interdisciplinary field, to characterize the advances that have been made, and to identify future research directions and opportunities.
Interconnected Cloud Computing Environments
Authors: Toosi Adel Nadjaran , Calheiros Rodrigo N. , Buyya Rajkumar
Published: May 2014

A brief review of the Internet history reveals the fact that the Internet evolved after the formation of primarily independent networks. Similarly, interconnected clouds, also called
Inter-cloud
, can be viewed as a natural evolution of cloud computing. Recent studies show the benefits in utilizing multiple clouds and present attempts for the realization of an Inter-cloud or federated cloud environment. However, cloud vendors have not taken into account cloud interoperability issues, and each cloud comes with its own solution and interfaces for services. This survey initially discusses all the relevant aspects motivating cloud interoperability. Furthermore, it categorizes and identifies possible cloud interoperability scenarios and architectures. The spectrum of challenges and obstacles that the Inter-cloud realization is faced with are covered, a taxonomy of them is provided, and fitting enablers that tackle each challenge are identified. All these aspects require a comprehensive review of the state of the art, including ongoing projects and studies in the area. We conclude by discussing future directions and trends toward the holistic approach in this regard.
Randomized Rounding in the Presence of a Cardinality Constraint
Authors: Doerr Benjamin , Wahlström Magnus
Published: May 2014

We consider the problem of generating randomized roundings that satisfy a single cardinality constraint and admit Chernoff-type large deviation bounds for weighted sums of the variables. That this can be done efficiently was proven by Srinivasan [2001], a different approach was later given by the first author [Doerr 2006]. In this work, we (a) present an improved version of the bitwise derandomization given by Doerr, (b) give the first derandomization of Srinivasan's tree-based randomized approach and prove its correctness, and (c) experimentally compare the resulting algorithms.

Our experiments show that adding a single cardinality constraint typically reduces the rounding errors and only moderately increases the running times. In general, our derandomization of the tree-based approach is superior to the derandomized bitwise one, while the two randomized versions produce very similar rounding errors. When implementing the derandomized tree-based approach, however, the choice of the tree is important.
A Survey of User Interaction for Spontaneous Device Association
Authors: Chong Ming Ki , Mayrhofer Rene , Gellersen Hans
Published: May 2014

In a wireless world, users can establish ad hoc virtual connections between devices that are unhampered by cables. This process is known as
spontaneous device association
. A wide range of interactive protocols and techniques have been demonstrated in both research and practice, predominantly with a focus on security aspects. In this article, we survey spontaneous device association with respect to the user interaction it involves. We use a novel taxonomy to structure the survey with respect to the different conceptual models and types of user action employed for device association. Within this framework, we provide an in-depth survey of existing techniques discussing their individual characteristics, benefits, and issues.
Fast Convergence for Consensus in Dynamic Networks
Authors: Chan T.-H. Hubert , Ning Li
Published: May 2014

In this article, we study the convergence time required to achieve consensus in dynamic networks. In each timestep, a node's value is updated to some weighted average of its neighbors and its old values. We study the case when the underlying network is dynamic and investigate different averaging models. Both our analysis and experiments show that dynamic networks exhibit fast convergence behavior, even under very mild connectivity assumptions.
Evolutionary Network Analysis
Authors: Aggarwal Charu , Subbian Karthik
Published: May 2014

Evolutionary network analysis has found an increasing interest in the literature because of the importance of different kinds of dynamic social networks, email networks, biological networks, and social streams. When a network evolves, the results of data mining algorithms such as community detection need to be correspondingly updated. Furthermore, the specific kinds of changes to the structure of the network, such as the impact on community structure or the impact on network structural parameters, such as node degrees, also needs to be analyzed. Some dynamic networks have a much faster rate of edge arrival and are referred to as network streams or graph streams. The analysis of such networks is especially challenging, because it needs to be performed with an online approach, under the one-pass constraint of data streams. The incorporation of content can add further complexity to the evolution analysis process. This survey provides an overview of the vast literature on graph evolution analysis and the numerous applications that arise in different contexts.
Knowledge sharing in communities of practice
Authors: Boh Wai Fong
Published: May 2014

With the prevalent use of virtual Communities of Practice (CoPs) in organizations to link networks of individuals located in disparate geographical areas, information communication technologies (ICTs) take on a crucial role in supporting CoPs. In this paper, I examine the role that ICTs play in supporting knowledge sharing in virtual CoPs. In particular, I examine the use of two key types of ICTs -- knowledge repositories and online discussion forums. Based on the perceived cost of using these two types of ICTs, I theorize about how various factors would differ in their influence on knowledge sourcing from knowledge repositories and from online discussion forums. Two event-driven surveys were conducted with members of a CoP in a consulting firm to test the hypotheses. The surveys were conducted when CoP members downloaded documents from the knowledge repository and when CoP members posted inquiries and received responses in an online discussion forum. The results of the event-driven surveys partially support the hypotheses and show the importance of understanding the perceived costs of using the ICT to support knowledge reuse when we study knowledge sharing in virtual CoPs and in other settings that depend significantly on technological tools for knowledge sharing.
Improving performance and lifetime of the SSD RAID-based host cache through a log-structured approach
Authors: Oh Yongseok , Choi Jongmoo , Lee Donghee , Noh Sam H.
Published: May 2014

This paper proposes a cost-effective and reliable SSD host cache solution that we call SRC (SSD RAID Cache). Costeffectiveness is brought about by using multiple low-cost SSDs and reliability is enhanced through RAID-based data redundancy. RAID, however, is managed in a log-structured manner on multiple SSDs effectively eliminating the detrimental read-modify-write operations found in conventional RAID-5. Within the proposed framework, we also propose to eliminate parity blocks for stripes that are composed of clean blocks as the original data resides in primary storage. We also propose the use of destaging, instead of garbage collection, to make space in the cache when the SSD cache is full. We show that the proposed techniques have significant implications on the performance of the cache and lifetime of the SSDs that comprise the cache. Finally, we study various ways in which stripes can be formed based on data and parity block allocation policies. Our experimental results using different realistic I/O workloads show using the SRC scheme is on average 59% better than the conventional SSD cache scheme supporting RAID-5. In case of lifetime, our results show that SRC reduces the erase count of the SSD drives by an average of 47% compared to the RAID-5 scheme.
Modeling of Failure Prediction Bayesian Network with Divide‐and‐Conquer Principle
Authors: Cai Zhiqiang , Si Weitao , Si Shubin , Sun Shudong
Published: May 2014

For system failure prediction, automatically modeling from historical failure dataset is one of the challenges in practical engineering fields. In this paper, an effective algorithm is proposed to build the failure prediction Bayesian network (FPBN) model with data mining technology. First, the conception of FPBN is introduced to describe the state of components and system and the cause‐effect relationships among them. The types of network nodes, the directions of network edges, and the conditional probability distributions (CPDs) of nodes in FPBN are discussed in detail. According to the characteristics of nodes and edges in FPBN, a divide‐and‐conquer principle based algorithm (FPBN‐DC) is introduced to build the best FPBN network structures of different types of nodes separately. Then, the CPDs of nodes in FPBN are calculated by the maximum likelihood estimation method based on the built network. Finally, a simulation study of a helicopter convertor model is carried out to demonstrate the application of FPBN‐DC. According to the simulations results, the FPBN‐DC algorithm can get better fitness value with the lower number of iterations, which verified its effectiveness and efficiency compared with traditional algorithm.
Invertibility and Explicit Inverses of Circulant-Type Matrices withk-Fibonacci andk-Lucas Numbers
Authors: Jiang Zhaolin , Gong Yanpeng , Gao Yun
Published: May 2014

Circulant matrices have important applications in solving ordinary differential equations. In this paper, we consider circulant-type matrices with thek-Fibonacci andk-Lucas numbers. We discuss the invertibility of these circulant matrices and present the explicit determinant and inverse matrix by constructing the transformation matrices, which generalizes the results in Shen et al. (2011).
Discrete‐Time Optimal Control of Photovoltaic Grid‐Connected Inverter Based on Particle Swarm Optimization
Authors: Liu Xinrui , Zhang Guangru , Yang Dongsheng , Shi Tongyu , He Xusheng
Published: May 2014

This paper is concerned with the problem of optimal control of photovoltaic grid‐connected inverter. Firstly, the discrete‐time
nonlinear mathematical model of single‐phase photovoltaic grid‐connected inverter in the rotating coordinate system is constructed by the Delta operator, which simplifies the control process and facilitates direct digital realization. Then, a novel optimal control method which is significant to achieve trajectory
tracking for photovoltaic grid‐connected inverter is developed by constructing a control Lyapunov functional against the difficulty of solving HJB (Hamilton‐Jacobi‐Bellman) partial differential equations. More importantly, the performance matrix of the controller which is very meaningful to many performance indicators of the system is also optimized via the particle swarm optimization. Finally, two numerical examples are provided to
illustrate the effectiveness of the proposed method.
Abdominal Fat and Sarcopenia in Women Significantly Alter Osteoblasts HomeostasisIn Vitroby a WNT/β-Catenin Dependent Mechanism
Authors: Wannenes Francesca , Papa Vincenza , Greco Emanuela A. , Fornari Rachele , Marocco Chiara , Baldari Carlo , Di Luigi Luigi , Emerenziani Gian Pietro , Poggiogalle Eleonora , Guidetti Laura , Donini Lorenzo M. , Lenzi Andrea , Migliaccio Silvia
Published: May 2014

Obesity and sarcopenia have been associated with mineral metabolism derangement and low bone mineral density (BMD). We investigated whether imbalance of serum factors in obese or obese sarcopenic patients could affect bone cell activityin vitro. To evaluate and characterize potential cellular and molecular changes of human osteoblasts, cells were exposed to sera of four groups of patients: (1) affected by obesity with normal BMD (O), (2) affected by obesity with low BMD (OO), (3) affected by obesity and sarcopenia (OS), and (4) affected by obesity, sarcopenia, and low BMD (OOS) as compared to subjects with normal body weight and normal BMD (CTL). Patients were previously investigated and characterized for body composition, biochemical and bone turnover markers. Then, sera of different groups of patients were used to incubate human osteoblasts and evaluate potential alterations in cell homeostasis. Exposure to OO, OS, and OOS sera significantly reduced alkaline phosphatase, osteopontin, and BMP4 expression compared to cells exposed to O and CTL, indicating a detrimental effect on osteoblast differentiation. Interestingly, sera of all groups of patients induced intracellular alteration in Wnt/β-catenin molecular pathway, as demonstrated by the significant alteration of specific target genes expression and by alteredβ-catenin cellular compartmentalization and GSK3βphosphorylation. In conclusion our results show for the first time that sera of obese subjects with low bone mineral density and sarcopenia significantly alter osteoblasts homeostasisin vitro, indicating potential detrimental effects of trunk fat on bone formation and skeletal homeostasis.
Combinatorial Optimization Method for Operation of Pumping Station with Adjustable Blade and Variable Speed Based on Experimental Optimization of Subsystem
Authors: Gong Yi , Cheng Jilin
Published: May 2014

A decomposition-dynamic programming aggregation method based on experimental optimization for subsystem was proposed to solve mathematical model of optimal operation for single pumping station with adjustable blade and variable speed. Taking minimal daily electric cost as objective function and water quantity pumped by units as coordinated variable, this model was decomposed into several submodels of daily optimal operation with adjustable blade and variable speed for single pump unit which was solved by experimental optimization. The constructed aggregation model took water quantity pumped by each pump unit as decision variable and discrete values of water quantity pumped by pumping station as state variable and was solved by one-dimensional dynamic programming. Taking operation of typical pumping station as a study case, optimal operation with adjustable blade and variable speed, respectively, had an average cost saving of 4.19%, 22.15%, and 29.86% compared with operation with fixed blade angle and constant speed under 100%, 80%, and 60% load, which also had a remarkable saving amplitude of 15.85% and 24.18%, respectively, corresponding to 80% load and 60% load compared with operation with adjustable blade and constant speed. Meanwhile, the proposed method has provided a new way for solving complex nonlinear mathematical models with 3 decision variables.
TSMC: A Novel Approach for Live Virtual Machine Migration
Authors: Song Jiaxing , Liu Weidong , Yin Feiran , Gao Chao
Published: May 2014

Cloud computing attracted more and more attention in recent years, and virtualization technology is the key point for deploying infrastructure services in cloud environment. It allows application isolation and facilitates server consolidation, load balancing, fault management, and power saving. Live virtual machine migration can effectively relocate virtual resources and it has become an important management method in clusters and data centers. Existing precopy live migration approach has to iteratively copy redundant memory pages; another postcopy live migration approach would lead to a lot of page faults and application degradation. In this paper, we present a novel approach called TSMC (three-stage memory copy) for live virtual machine migration. In TSMC, memory pages only need to be transmitted twice at most and page fault just occurred in small part of dirty pages. We implement it in Xen and compare it with Xen’s original precopy approach. The experimental results under various memory workloads show that TSMC approach can significantly reduce the cumulative migration time and total pages transferred and achieve better network IO performance in the same time.
Reputation-Based Secure Sensor Localization in Wireless Sensor Networks
Authors: He Jingsha , Xu Jing , Zhu Xingye , Zhang Yuqiang , Zhang Ting , Fu Wanqing
Published: May 2014

Location information of sensor nodes in wireless sensor networks (WSNs) is very important, for it makes information that is collected and reported by the sensor nodes spatially meaningful for applications. Since most current sensor localization schemes rely on location information that is provided by beacon nodes for the regular sensor nodes to locate themselves, the accuracy of localization depends on the accuracy of location information from the beacon nodes. Therefore, the security and reliability of the beacon nodes become critical in the localization of regular sensor nodes. In this paper, we propose a reputation-based security scheme for sensor localization to improve the security and the accuracy of sensor localization in hostile or untrusted environments. In our proposed scheme, the reputation of each beacon node is evaluated based on a reputation evaluation model so that regular sensor nodes can get credible location information from highly reputable beacon nodes to accomplish localization. We also perform a set of simulation experiments to demonstrate the effectiveness of the proposed reputation-based security scheme. And our simulation results show that the proposed security scheme can enhance the security and, hence, improve the accuracy of sensor localization in hostile or untrusted environments.
Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors
Authors: Chang Jing-Yi , Kuan Yean-Der , Lee Shi-Min
Published: May 2014

The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of2×2,4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC) current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS) experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.
CdTeO3 Deposited Mesoporous NiO Photocathode for a Solar Cell
Authors: Zhao Chuan , Zou Xiaoping , He Sheng
Published: May 2014

Semiconductor sensitized NiO photocathodes have been fabricated by successive ionic layer adsorption and reaction (SILAR) method depositing CdTeO3 quantum dots onto mesoscopic NiO films. A solar cell using CdTeO3 deposited NiO mesoporous photocathode has been fabricated. It yields a photovoltage of 103.7 mV and a short‐circuit current density of 0.364 mA/cm2. The incident photon to current conversion efficiency (IPCE) value is found to be 12% for the newly designed NiO/CdTeO3 solar cell. It shows that the p‐type NiO/CdTeO3 structure could be successfully utilized to fabricate p‐type solar cell.
Flow Diverters for Intracranial Aneurysms
Authors: Alderazi Yazan J. , Shastri Darshan , Kass-Hout Tareq , Prestigiacomo Charles J. , Gandhi Chirag D.
Published: May 2014

Flow diverters (pipeline embolization device, Silk flow diverter, and Surpass flow diverter) have been developed to treat intracranial aneurysms. These endovascular devices are placed within the parent artery rather than the aneurysm sac. They take advantage of altering hemodynamics at the aneurysm/parent vessel interface, resulting in gradual thrombosis of the aneurysm occurring over time. Subsequent inflammatory response, healing, and endothelial growth shrink the aneurysm and reconstruct the parent artery lumen while preserving perforators and side branches in most cases. Flow diverters have already allowed treatment of previously untreatable wide neck and giant aneurysms. There are risks with flow diverters including in-stent thrombosis, perianeurysmal edema, distant and delayed hemorrhages, and perforator occlusions. Comparative efficacy and safety against other therapies are being studied in ongoing trials. Antiplatelet therapy is mandatory with flow diverters, which has highlighted the need for better evidence for monitoring and tailoring antiplatelet therapy. In this paper we review the devices, their uses, associated complications, evidence base, and ongoing studies.
Regulations of P-Glycoprotein/ABCB1/MDR1in Human Cancer Cells
Authors: Katayama Kazuhiro , Noguchi Kohji , Sugimoto Yoshikazu
Published: May 2014

Multidrug resistance (MDR) in cancer cells is a phenotype whereby cells display reduced sensitivity to anticancer drugs, based on a variety of mechanisms, including an increase in drug efflux, the reduction of drug uptake, the activation of cell growth and survival signaling, the promotion of DNA repair, and the inhibition of apoptosis signaling. Increased expression of the plasma membrane drug efflux pumps, the ATP-binding cassette (ABC) transporters, is involved in MDR. P-Glycoprotein/ABCB1 is a member of the ABC transporter family, and facilitates the efflux of various anticancer drugs, including anthracyclines,vincaalkaloids, epipodophyllotoxins, taxanes, and kinase inhibitors, from cells. P-Glycoprotein is also expressed in normal tissues and cells, including the kidney, liver, colon, and adrenal gland, to transport and/or secrete substrates and at the blood-brain, blood-placenta, and blood-testis barriers to protect these tissues from toxic substances. To understand the mechanistic functions of P-glycoprotein and to overcome MDR, investigators have identified the substrates and competitive inhibitors of P-glycoprotein. Recently, we and other groups reported associations between cellular signaling pathways and the expression, stability, degradation, localization, and activity of P-glycoprotein. The present review summarizes the currently available information about the transcriptional and posttranslational regulation of P-glycoprotein expression and function.
Using Heuristic Value Prediction and Dynamic Task Granularity Resizing to Improve Software Speculation
Authors: Xu Fan , Shen Li , Wang Zhiying , Su Bo , Guo Hui , Chen Wei
Published: May 2014

Exploiting potential thread-level parallelism (TLP) is becoming the key factor to improving performance of programs on multicore or many-core systems. Among various kinds of parallel execution models, the software-based speculative parallel model has become a research focus due to its low cost, high efficiency, flexibility, and scalability. The performance of the guest program under the software-based speculative parallel execution model is closely related to the speculation accuracy, the control overhead, and the rollback overhead of the model. In this paper, we first analyzed the conventional speculative parallel model and presented an analytic model of its expectation of the overall overhead, then optimized the conventional model based on the analytic model, and finally proposed a novel speculative parallel model named HEUSPEC. The HEUSPEC model includes three key techniques, namely, the heuristic value prediction, the value based correctness checking, and the dynamic task granularity resizing. We have implemented the runtime system of the model in ANSI C language. The experiment results show that when the speedup of the HEUSPEC model can reach 2.20 on the average (15% higher than conventional model) when depth is equal to 3 and 4.51 on the average (12% higher than conventional model) when speculative depth is equal to 7. Besides, it shows good scalability and lower memory cost.
Family Context and Khat Chewing among Adult Yemeni Women: A Cross-Sectional Study
Authors: AL-abed AL-abed Ali , Sutan Rosnah , Al-Dubai Sami Abdo Radman , Aljunid Syed Mohamed
Published: May 2014

Khat chewing is associated with unfavourable health outcomes and family dysfunction. Few studies have addressed the factors associated with khat chewing among Yemeni women. However, the family and husband effects on chewing khat by women have not been addressed. This study aimed to determine the prevalence of khat chewing among Yemeni women and its associated factors, particularly husbands and family factors. A cross-sectional study was conducted among 692 adult Yemeni women in the city of Sana’a in Yemen using structured “face to face” interviews. Mean (±SD) age of women was 27.3 years (±6.10). The prevalence of chewing khat by women was 29.6%. Factors associated with chewing khat among women were chewing khat by husbands (OR=1.8; 95% CI: 1.26, 2.53), being married (OR=2.0; 95% CI: 1.20, 3.37), frequent family social gatherings (OR=1.5; 95% CI: 1.06, 2.10), high family income (OR=1.57; 95% CI: 1.12, 2.21), larger house (OR=1.63; 95% CI: 1.16, 2.31), and age of women (OR=0.64; 95% CI: 0.44, 0.92). It is concluded that khat chewing by women in this study was significantly associated with family factors and with khat chewing by their husbands. Urgent action is needed to control khat chewing particularly among women.
A Case of Femoral Arteriovenous Fistula Causing High-Output Cardiac Failure, Originally Misdiagnosed as Chronic Fatigue Syndrome
Authors: Porter J. , Al-Jarrah Q. , Richardson S.
Published: May 2014

Percutaneous arterial catheterisation is commonly undertaken for a range of diagnostic and interventional procedures. Iatrogenic femoral arteriovenous fistulas are an uncommon complication of these procedures. Most are asymptomatic and close spontaneously, but can rarely increase in size leading to the development of symptoms. We report a case of an iatrogenic femoral arteriovenous fistula, causing worsening congestive cardiac failure, in a 34-year-old marathon runner. This was originally diagnosed as chronic fatigue syndrome. Following clinical examination, duplex ultrasound, and CT angiography a significant arteriovenous fistula was confirmed. Elective open surgery was performed, leading to a dramatic and rapid improvement in symptoms. Femoral arteriovenous fistulas have the potential to cause significant haemodynamic effects and can present many years after the initial procedure. Conservative, endovascular, and open surgical management strategies are available.
On Fuzzy Fixed Points for Fuzzy Maps with Generalized Weak Property
Authors: Kutbi Marwan Amin , Ahmad Jamshaid , Azam Akbar , Hussain Nawab
Published: May 2014

Let(X,d)be a complex valued metric space and letS,Tbe mappings fromXto a set of all fuzzy subsets ofX. We present sufficient conditions for the existence of a commonα-fuzzy fixed point ofSandT. Our results improve and extend certain recent results in literature. Moreover, we discuss an illustrative example to highlight the realized improvements.
Hypovigilance Detection for UCAV Operators Based on a Hidden Markov Model
Authors: Choi Yerim , Kwon Namyeon , Lee Sungjun , Shin Yongwook , Ryo Chuh Yeop , Park Jonghun , Shin Dongmin
Published: May 2014

With the advance of military technology, the number of unmanned combat aerial vehicles (UCAVs) has rapidly increased. However, it has been reported that the accident rate of UCAVs is much higher than that of manned combat aerial vehicles. One of the main reasons for the high accident rate of UCAVs is the hypovigilance problem which refers to the decrease in vigilance levels of UCAV operators while maneuvering. In this paper, we propose hypovigilance detection models for UCAV operators based on EEG signal to minimize the number of occurrences of hypovigilance. To enable detection, we have applied hidden Markov models (HMMs), two of which are used to indicate the operators’ dual states, normal vigilance and hypovigilance, and, for each operator, the HMMs are trained as a detection model. To evaluate the efficacy and effectiveness of the proposed models, we conducted two experiments on the real-world data obtained by using EEG-signal acquisition devices, and they yielded satisfactory results. By utilizing the proposed detection models, the problem of hypovigilance of UCAV operators and the problem of high accident rate of UCAVs can be addressed.
Travelling Waves of an n-Species Food Chain Model with Spatial Diffusion and Time Delays
Authors: Hu Fei , Xu Yuyin , Wang Z. , Ding Wei
Published: May 2014

We investigate an n-species food chain model with spatial diffusion and time delays. By using Schauder’s fixed point theorem, we obtain the result about the existence of the travelling wave solutions of the food chain model with reaction term satisfying the partial quasimonotonicity conditions.
Anticoagulant Activity of Polyphenolic‐Polysaccharides Isolated from Melastoma malabathricum L.
Authors: Khoo Li Teng , Abas Faridah , Abdullah Janna Ong , Mohd Tohit Eusni Rahayu , Hamid Muhajir
Published: May 2014

Melastoma malabathricum Linn. is a perennial traditional medicine plants that grows abundantly throughout Asian countries. In this study, M. malabathricum Linn. leaf hot water crude extract with anticoagulant activity was purified through solid phase extraction cartridge and examined for the bioactive chemical constituents on blood coagulation reaction. The SPE purified fractions were, respectively, designated as F1, F2, F3, and F4, and each was subjected to the activated partial thromboplastin time (APTT) anticoagulant assay. Active anticoagulant fractions (F1, F2, and F3) were subjected to chemical characterisation evaluation. Besides, neutral sugar for carbohydrate part was also examined. F1, F2, and F3 were found to significantly prolong the anticoagulant activities in the following order, F1 > F2 > F3, in a dose dependent manner. In addition, carbohydrate, hexuronic acid, and polyphenolic moiety were measured for the active anticoagulant fractions (F1, F2, and F3). The characterisation of chemical constituents revealed that all these three fractions contained acidic polysaccharides (rhamnogalacturonan, homogalacturonan, and rhamnose hexose‐pectic type polysaccharide) and polyphenolics. Hence, it was concluded that the presence of high hexuronic acids and polysaccharides, as well as polyphenolics in traditional medicinal plant, M. malabathricum, played a role in prolonging blood clotting in the intrinsic pathway.
Application of Molecular Modeling to Urokinase Inhibitors Development
Authors: Sulimov V. B. , Katkova E. V. , Oferkin I. V. , Sulimov A. V. , Romanov A. N. , Roschin A. I. , Beloglazova I. B. , Plekhanova O. S. , Tkachuk V. A. , Sadovnichiy V. A.
Published: May 2014

Urokinase-type plasminogen activator (uPA) plays an important role in the regulation of diverse physiologic and pathologic processes. Experimental research has shown that elevated uPA expression is associated with cancer progression, metastasis, and shortened survival in patients, whereas suppression of proteolytic activity of uPA leads to evident decrease of metastasis. Therefore, uPA has been considered as a promising molecular target for development of anticancer drugs. The present study sets out to develop the new selective uPA inhibitors using computer-aided structural based drug design methods. Investigation involves the following stages: computer modeling of the protein active site, development and validation of computer molecular modeling methods: docking (SOL program), postprocessing (DISCORE program), direct generalized docking (FLM program), and the application of the quantum chemical calculations (MOPAC package), search of uPA inhibitors among molecules from databases of ready-made compounds to find new uPA inhibitors, and design of new chemical structures and their optimization and experimental examination. On the basis of known uPA inhibitors and modeling results, 18 new compounds have been designed, calculated using programs mentioned above, synthesized, and testedin vitro. Eight of them display inhibitory activity and two of them display activity about 10 μM.
A Digital Signature Scheme Based on MST3 Cryptosystems
Authors: Hong Haibo , Li Jing , Wang Licheng , Yang Yixian , Niu Xinxin
Published: May 2014

As special types of factorization of finite groups, logarithmic signature and cover have been used as the main components of cryptographic keys for secret key cryptosystems such as PGM and public key cryptosystems like MST1, MST2, and MST3. Recently, Svaba et. al proposed a revised MST3 encryption scheme with greater security. Meanwhile, they put forward an idea of constructing signature schemes on the basis of logarithmic signatures and random covers. In this paper, we firstly design a secure digital signature scheme based on logarithmic signatures and random covers. In order to complete the task, we devise a new encryption scheme based on MST3 cryptosystems.
Application of Ethnobotanical Indices on the Use of Traditional Medicines against Common Diseases
Authors: Khan Imran , AbdElsalam Naser M. , Fouad Hassan , Tariq Akash , Ullah Riaz , Adnan Muhammad
Published: May 2014

The present study was aimed at documenting the detailed ethnomedicinal knowledge of an unexplored area of Pakistan. Semistructured interviews were taken with 55 informants randomly chosen regarding detailed ethnomedicinal and sociocultural information. The study exposed 67 medicinal plant species used to prepare 110 recipes and the major modes of herbal formulation were decoction and powdering (20% each). The disease categories with the highest Fic values were gastrointestinal and dermatological (0.87 each). The study determined 3 plant species, i.e., Acacia modesta Wall., Caralluma tuberculata R.Br., and Withania somnifera (L.) Dunal with a FL of 100%. DMR results showed that Olea ferruginea (Sol.) Steud. ranked first, Morus alba L. ranked second, and Melia azedarach L. ranked third. Among the 55 informants, the male concentration was high (61%) and most of them were over 40 years old while a leading quantity of respondents (45%) was uneducated. There is a dire need to take necessary steps for the conservation of important medicinal plants by inhibiting overgrazing and providing alternate fuel resources. Young generations should be educated regarding the importance of ethnomedicinal knowledge and plants with high Fic and FL values should be further checked chemically and pharmacologically for future exploration of modern medicine.
Clinical Course, Prognosis, and Cause of Death in Primary Sjögren’s Syndrome
Authors: Horvath Ildiko Fanny , Szanto Antonia , Papp Gabor , Zeher Margit
Published: May 2014

The aim of this retrospective, single-centre study was to investigate the clinical and laboratory features and disease outcomes of 547 patients diagnosed with primary Sjögren’s syndrome (pSS) between 1975 and 2010. The patients were followed up for11.4±6.2years. We evaluated the clinical and laboratory features, and assessed their influence on the time of diagnosis, survival, and mortality ratios, and compared them within subgroups defined by gender, glandular and extraglandular manifestations (EGMs), associated diseases, and immunoserological abnormalities. The most frequent EGMs were polyarthritis, Raynaud’s phenomenon, and vasculitis among our patients; the most common associated disease was thyroiditis. During the follow-up period, 51 patients died; the median survival time was 33.71 years. Our results revealed a negative effect of cryoglobulinemia on survival ratios; additionally, the presence of vasculitis and lymphoproliferative diseases at the time of diagnosis increased the risk of mortality. The development of vasculitis was the most powerful predictor of mortality. Mortality in the group of patients with extraglandular symptoms was two- to threefold higher than in the glandular group. Attention is drawn to the importance of close monitoring and targeted diagnostic approaches in those pSS subgroups with obviously increased mortality risk.
Design and Optimization of LTE 1800 MIMO Antenna
Authors: Wong Huey Shin , Islam Mohammad Tariqul , Kibria Salehin
Published: May 2014

A multiple input and multiple output (MIMO) antenna that comprises a printed microstrip antenna and a printed double-L sleeve monopole antenna for LTE 1800 wireless application is presented. The printed double-L sleeve monopole antenna is fed by a 50 ohm coplanar waveguide (CPW). A novel T-shaped microstrip feedline printed on the other side of the PCB is used to excite the waveguide’s outer shell. Isolation characteristics better than −15 dB can be obtained for the proposed MIMO antenna. The proposed antenna can operate in LTE 1800 (1710 MHz–1880 MHz). This antenna exhibits omnidirectional characteristics. The efficiency of the antenna is greater than 70% and has high gain of 2.18 dBi.
100 Gy60Coγ-Ray Induced Novel Mutations in Tetraploid Wheat
Authors: Yang Chuntao , Zhu Jianshu , Jiang Yun , Wang Xiaolu , Gu Mengxue , Wang Yi , Kang Houyang , Fan Xing , Sha Lina , Zhang Haiqin , Xuan Pu , Zhou Yonghong
Published: May 2014

10 accessions of tetraploid wheat were radiated with 100 Gy60Coγ-ray. The germination energy, germination rate, special characters (secondary tillering, stalk with wax powder, and dwarf), meiotic process, and high-molecular-weight glutenin subunits (HMW-GSs) were observed. Different species has different radiation sensibility. With 1 seed germinated (5%),T. dicoccum(PI434999) is the most sensitive to this dose of radiation. With a seed germination rate of 35% and 40%, this dose also affectedT. polonicum(As304) andT. carthlicum(As293). Two mutant dwarf plants,T. turgidum(As2255) 253-10 andT. polonicum(As302) 224-14, were detected. Abnormal chromosome pairings were observed in pollen mother cells of bothT. dicoccoides(As835) 237-9 andT. dicoccoides(As838) 239-8 with HMW-GS 1Ax silent in seeds from them. Compared with the unirradiated seed ofT. polonicum(As304) CK, a novel HMW-GS was detected in seed ofT. polonicum(As304) 230-7 and its electrophoretic mobility was between 1By8 and 1Dy12 which were the HMW-GSs of Chinese Spring. These mutant materials would be resources for wheat breeding.