bluuebunny/crossref_metadata_2025 huggingface dataset:
Diversity in the Enteric Viruses Detected in Outbreaks of Gastroenteritis from Mumbai, Western India
Authors: Chitambar Shobha , Gopalkrishna Varanasi , Chhabra Preeti , Patil Pooja , Verma Harsha , Lahon Anismrita , Arora Ritu , Tatte Vaishali , Ranshing Sujata , Dhale Ganesh , Kolhapure Rajendra , Tikute Sanjay , Kulkarni Jagannath , Bhardwaj Renu , Akarte Sulbha , Pawar Sashikant
Published: March 2012

Faecal specimens collected from two outbreaks of acute gastroenteritis that occurred in southern Mumbai, India in March and October, 2006 were tested for seven different enteric viruses. Among the 218 specimens tested, 95 (43.6%) were positive, 73 (76.8%) for a single virus and 22 (23.2%) for multiple viruses. Single viral infections in both, March and October showed predominance of enterovirus (EV, 33.3% and 40%) and rotavirus A (RVA, 33.3% and 25%). The other viruses detected in these months were norovirus (NoV, 12.1% and 10%), rotavirus B (RVB, 12.1% and 10%), enteric adenovirus (AdV, 6.1% and 7.5%), Aichivirus (AiV, 3% and 7.5%) and human astrovirus (HAstV, 3% and 0%). Mixed viral infections were largely represented by two viruses (84.6% and 88.9%), a small proportion showed presence of three (7.7% and 11%) and four (7.7% and 0%) viruses in the two outbreaks. Genotyping of the viruses revealed predominance of RVA G2P[4], RVB G2 (Indian Bangladeshi lineage), NoV GII.4, AdV-40, HAstV-8 and AiV B types. VP1/2A junction region based genotyping showed presence of 11 different serotypes of EVs. Although no virus was detected in the tested water samples, examination of both water and sewage pipelines in gastroenteritis affected localities indicated leakages and possibility of contamination of drinking water with sewage water. Coexistence of multiple enteric viruses during the two outbreaks of gastroenteritis emphasizes the need to expand such investigations to other parts of India.
Comprehensive Study of Lanthanum Aluminate High-Dielectric-Constant Gate Oxides for Advanced CMOS Devices
Authors: Suzuki Masamichi
Published: March 2012

A comprehensive study of the electrical and physical characteristics of Lanthanum Aluminate (LaAlO3) high-dielectric-constant gate oxides for advanced CMOS devices was performed. The most distinctive feature of LaAlO3 as compared with Hf-based high-k materials is the thermal stability at the interface with Si, which suppresses the formation of a low-permittivity Si oxide interfacial layer. Careful selection of the film deposition conditions has enabled successful deposition of an LaAlO3 gate dielectric film with an equivalent oxide thickness (EOT) of 0.31 nm. Direct contact with Si has been revealed to cause significant tensile strain to the Si in the interface region. The high stability of the effective work function with respect to the annealing conditions has been demonstrated through comparison with Hf-based dielectrics. It has also been shown that the effective work function can be tuned over a wide range by controlling the La/(La + Al) atomic ratio. In addition, gate-first n-MOSFETs with ultrathin EOT that use sulfur-implanted Schottky source/drain technology have been fabricated using a low-temperature process.
Stoichiometry Based Steady-State Hepatic Flux Analysis: Computational and Experimental Aspects
Authors: Orman Mehmet A. , Mattick John , Androulakis Ioannis P. , Berthiaume Francois , Ierapetritou Marianthi G.
Published: March 2012

The liver has many complex physiological functions, including lipid, protein and carbohydrate metabolism, as well as bile and urea production. It detoxifies toxic substances and medicinal products. It also plays a key role in the onset and maintenance of abnormal metabolic patterns associated with various disease states, such as burns, infections and major traumas. Liver cells have been commonly used in in vitro experiments to elucidate the toxic effects of drugs and metabolic changes caused by aberrant metabolic conditions, and to improve the functions of existing systems, such as bioartificial liver. More recently, isolated liver perfusion systems have been increasingly used to characterize intrinsic metabolic changes in the liver caused by various perturbations, including systemic injury, hepatotoxin exposure and warm ischemia. Metabolic engineering tools have been widely applied to these systems to identify metabolic flux distributions using metabolic flux analysis or flux balance analysis and to characterize the topology of the networks using metabolic pathway analysis. In this context, hepatic metabolic models, together with experimental methodologies where hepatocytes or perfused livers are mainly investigated, are described in detail in this review. The challenges and opportunities are also discussed extensively.
Modeling and Control of Electrowetting Induced Droplet Motion
Authors: Oprins Herman , Vandevelde Bart , Baelmans Martine
Published: March 2012

In this paper, a general methodology for the dynamic study of electrostatically actuated droplets is presented. A simplified 1D transient model is developed to investigate the transient response of a droplet to an actuation voltage and to study the effect of geometrical and fluid-thermal properties and electrical parameters on this behavior. First, the general approach for the dynamic droplet motion model is described. All forces acting on the droplet are introduced and presented in a simplified algebraic expression. For the retentive force, the empirically extracted correlations are used, and for the electrostatic actuation force, results from electrostatic finite element simulations are used. The dynamic model is applied to electrowetting induced droplet motion between parallel plates in the case of a single actuation electrode and for an array of electrodes. Using this methodology, the influence of the switching frequency and actuation voltage is studied. Furthermore, a linearized equivalent damped mass—spring model is presented to approximate the dynamic droplet motion. It is shown that the optimal switching frequency can be estimated by twice the natural frequency of the linearized damped mass—spring system.
Effective Permittivity for FDTD Calculation of Plasmonic Materials
Authors: Okada Naoki , Cole James B.
Published: March 2012

We present a new effective permittivity (EP) model to accurately calculate surface plasmons (SPs) using the finite-difference time-domain (FDTD) method. The computational representation of physical structures with curved interfaces causes inherent errors in FDTD calculations, especially when the numerical grid is coarse. Conventional EP models improve the errors, but they are not effective for SPs because the SP resonance condition determined by the original permittivity is changed by the interpolated EP values. We perform FDTD simulations using the proposed model for an infinitely-long silver cylinder and gold sphere, and the results are compared with Mie theory. Our model gives better accuracy than the conventional staircase and EP models for SPs.
Facile Synthesis and Herbicidal Evaluation of 4H-3,1-Benzoxazin-4-ones and 3H-Quinazolin-4-ones with 2-Phenoxymethyl Substituents
Authors: Aibibuli Zumuretiguli , Wang Yufeng , Tu Haiyang , Huang Xiaoting , Zhang Aidong
Published: March 2012

Series of 4H-3,1-benzoxazin-4-ones and 3H-quinazolin-4-ones with phenoxy-methyl substituents were rationally designed and easily synthesized via one-pot N-acylation/ring closure reactions of anthranilic acids with 2-phenoxyacetyl chlorides to yield the 4H-3,1-benzoxazin-4-ones, and subsequently substituted with amino derivatives to obtain the 3H-quinazolin-4-ones. The herbicidal evaluation was performed on the model plants barnyard grass (a monocotyledon) and rape (a dicotyledon), and most of the title compounds displayed high levels of phytotoxicity. The active substructure and inhibitory phenotype analysis indicated that these compounds could be attributed to the class of plant hormone inhibitors. A docking study of several representative compounds with the hormone receptor TIR1 revealed an appreciable conformational match in the active site, implicating these compounds are potential lead hits targeting this receptor.
Phenolic Concentrations and Antioxidant Properties of Wines Made from North American Grapes Grown in China
Authors: Zhu Lei , Zhang Yali , Deng Jiajin , Li Huirong , Lu Jiang
Published: March 2012

The characteristics of wine phenolics found in several North American and (for comparison) European grape cultivars grown in China were analyzed. This was done to find non-Vitis vinifera wines with prominent features in order to diversify the kinds of wines. The phenolic richness and antioxidant activity decreased in the order: red > rose > white wines. In the red wines, the American grape ‘Cynthiana’ had the highest total concentrations of phenols, anthocyanins, flavonols and phenolic acids, as well as antioxidant capacity, followed by the French hybrid ‘Chambourcin’, the lowest were detected in two European grape varieties, ‘Merlot’ and ‘Cabernet Sauvignon’, while the total flavon-3-ols levels were reversed among these red grape cultivars. The highest concentration of stilbenes out of all the wines analyzed was found in the ‘Merlot’ variety. There were significant differences among wine phenolic compositions between North American and European grape cultivars. The antioxidant activities were significantly related to the concentrations of total phenols (r2 = 0.996), anthocyanins (r2 = 0.984), flavonols (r2 = 0.850) and gallic acid (r2 = 0.797). The prominent features of wine aroma and nutrition could make the American grape wines attractive to consumers. It is therefore necessary to perform further research on cultural practices and wine making involving these grapes.
Electrochemical Oxidation of Cysteine at a Film Gold Modified Carbon Fiber Microelectrode Its Application in a Flow—Through Voltammetric Sensor
Authors: Wang Lai-Hao , Huang Wen-Shiuan
Published: March 2012

A flow-electrolytical cell containing a strand of micro Au modified carbon fiber electrodes (CFE) has been designedand characterized for use in a voltammatric detector for detecting cysteine using high-performance liquid chromatography. Cysteine is more efficiently electrochemical oxidized on a Au /CFE than a bare gold and carbon fiber electrode. The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents. For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L−1 was found. The limit of quantification for cysteine was below 60 ng·mL−1.
Electrical Characterization of Gold-DNA-Gold Structures in Presence of an External Magnetic Field by Means of I-V Curve Analysis
Authors: Khatir Nadia Mahmoudi , Banihashemian Seyedeh Maryam , Periasamy Vengadesh , Ritikos Richard , Majid Wan Haliza Abd , Rahman Saadah Abdul
Published: March 2012

This work presents an experimental study of gold-DNA-gold structures in the presence and absence of external magnetic fields with strengths less than 1,200.00 mT. The DNA strands, extracted by standard method were used to fabricate a Metal-DNA-Metal (MDM) structure. Its electric behavior when subjected to a magnetic field was studied through its current-voltage (I-V) curve. Acquisition of the I-V curve demonstrated that DNA as a semiconductor exhibits diode behavior in the MDM structure. The current versus magnetic field strength followed a decreasing trend because of a diminished mobility in the presence of a low magnetic field. This made clear that an externally imposed magnetic field would boost resistance of the MDM structure up to 1,000.00 mT and for higher magnetic field strengths we can observe an increase in potential barrier in MDM junction. The magnetic sensitivity indicates the promise of using MDM structures as potential magnetic sensors.
Predictive power of Koplik’s spots for the diagnosis of measles
Authors: Zenner Dominik , Nacul Luis
Published: March 2012

Introduction: Measles is a major cause of mortality globally. In many countries, management of measles is based on clinical suspicion, but the predictive value of clinical diagnosis depends on knowledge and population prevalence of measles. In the pre-vaccine era with high measles incidence, Koplik's spots (KS) were said to be "pathognomonic". This study prospectively evaluated test properties and diagnostic odds ratios (OR) of KS. Methodology: Data including KS status were prospectively collected for a six-month period on all suspected measles cases reported to the North-West London Health Protection Unit. Saliva test kits were sent to all cases and KS test properties were analysed against measles confirmation by PCR or IgM testing (gold standard). Results: The positive predictive value (PPV) of clinically suspecting measles was 50%. Using KS as diagnostic tool improved the PPV to 80% and the presence of KS was associated with confirmed measles in the multi-variable analysis (OR 7.2, 95% Confidence Interval 2.1-24.9, p=0.001). Conclusion: We found that Koplik's spots were highly predictive of confirmed measles and could be a good clinical tool to enable prompt measles management and control measures, as action often needs to be taken in the absence of laboratory confirmation. We suggest that current clinical case definitions might benefit from the inclusion of KS.
16S rRNA gene sequence analysis of a Brucella melitensis infection misidentified as Bergeyella zoohelcum
Authors: Dash Nihar , Panigrahi Debadatta , Al-Zarouni Mansour , Mishra Sanjeet
Published: March 2012

Misidentification of Brucella species from clinical specimens using commercial bacterial identification systems is a recurring problem. An isolate from a bacterimic patient was identified as Bergeyella zoohelcum by MicroScan Walk-Away (Siemens Healthcare Diagnostics Inc., West Sacramento, CA, USA) and as Brucella melitensis by Vitek 2 system (bioMérieux Inc., Durham, NC, USA). Because of this identification ambiguity by the two automated bacterial identification systems we performed 16S rRNA sequencing and serotyping of the isolate and confirmed it as a Brucella spp. Combining the sequence data with the Vitek 2 system data we conclude that the infection was caused by B. melitensis.
Presence of Helicobacter pylori in drinking water of Karachi, Pakistan
Authors: Khan Adnan , Farooqui Amber , Kazmi Shahana Urooj
Published: March 2012

Background: Prevalence of Helicobacter pylori (H. pylori) infection is an increasing problem in developing countries. Several environmental factors such as overcrowding, poverty, contaminated drinking water and food are considered to contribute toward transmission of infection; however, little is known about their definitive roles. The aim of this study is to investigate the presence of H. pylori in drinking water samples of Karachi, Pakistan. Methodology: Samples of drinking water were collected from 18 different towns located in the metropolitan area of Karachi. Samples were concentrated by membrane filtration method and subjected to PCR for the detection of H. pylori. Results: Two out of 50 (4%) samples collected from two different densely populated town areas were found to be positive for H. pylori. Conclusion: The study provides evidence for the presence of H. pylori in municipal drinking water of Karachi.
Trichinellosis in developing countries: is it neglected?
Authors: Bruschi Fabrizio
Published: March 2012

Trichinellosis is a foodborne zoonosis caused by the parasitic nematode Trichinella, which is characterized by an extremely wide host range and geographical distribution. The aim of the present review is to provide epidemiological information on animal and human trichinellosis occurring in developing countries in the different continents, where cooking habits along with poverty and poor sanitary conditions and lack of veterinary controls may facilitate the occurrence of human trichinellosis outbreaks. Countries have been considered according to the six regions designated by the World Health Organization (WHO): 1) WHO African Region, 2) WHO Region of the Americas, 3) WHO South-East Asia Region, 4) WHO European Region, 5) WHO Eastern Mediterranean Region, and 6) WHO Western Pacific Region. For the purposes of this article, developing countries are defined as those not industrialised according to the World Economic Outlook Report of the International Monetary Fund (http://www.imf.org); however, with regard to the European Region of WHO, only those countries that are not member states of the European Union will be considered.
Hacia un programa de investigación en Sociología de la Innovación
Authors: Fernández Esquinas Manuel
Published: March 2012

Este artículo realiza un análisis de los rasgos esenciales de la perspectiva sociológica sobre la innovación. El objetivo es ayudar a especificar aquellos conceptos y herramientas analíticas provenientes de la sociología que resultan útiles para estudiar los procesos de innovación económica. La estrategia de exposición comienza especificando los rasgos de esta especialidad a partir de la definición del objeto de estudio, de las influencias de otras especialidades y de los temas de investigación preferentes. Posteriormente se analizan los principales componentes de un programa de investigación en sociología de la innovación. Para ello se emplea la distinción habitual entre cultura y estructura social. En cada uno de estos ámbitos se definen los múltiples aspectos de la vida social que cubren esos conceptos, se indica su importancia para el análisis del fenómeno innovador y se especifican sus implicaciones para este campo de estudio.
Instituciones, innovación y transferencia de conocimiento: contribuciones de los estudios sobre las variedades del capitalismo
Authors: Pinto Hugo
Published: March 2012

Este trabajo realiza una interpretación de las teorías sobre las variedades del capitalismo resaltando sus implicaciones para la innovación, en especial para los procesos de transferencia de conocimiento entre la universidad y la empresa. Los estudios de las variedades del capitalismo señalan la importancia de la arquitectura institucional para la competitividad de los países. El debate pone de relieve las complementariedades institucionales como concepto útil en términos teóricos para explicar los procesos de desarrollo, así como necesidad de anclar el análisis institucional en datos empíricos. Estos enfoques son un complemento teórico importante para enmarcar los estudios sobre innovación, donde los procesos de transferencia de conocimiento se consideren uno de los aspectos esenciales del impulso de las innovaciones. El artículo realiza una revisión crítica de tres enfoques sobre variedades de capitalismo: el estudio precursor de Hall y Soskice, el de los sistemas empresariales de Whitley y el enfoque de la gobernanza de Amable y Boyer. Para cada uno de ellos se extraen corolarios que permiten conectarlos con los procesos de transferencia de conocimiento. El resultado señala que el foco central de atención a la empresa debe complementarse con un enfoque sistémico que permite ver la amplia gama de actores, donde la universidad se convierte en uno de los más relevantes. La intervención del gobierno es esencial en la configuración de un comportamiento innovador de los actores, para fomentar y promover el uso de diferentes mecanismos de transferencia de conocimiento.
Formación continua en centros de FP y actividades de innovación en las Pymes industriales
Authors: Lavía Cristina , Olazaran Mikel , Albizu Eneka , Otero Beatriz
Published: March 2012

La crisis actual, que afecta con especial virulencia a España, obliga a reflexionar sobre las relaciones entre el sistema educativo y el sistema económico. En este trabajo, basado en una encuesta a pequeñas y medianas empresas industriales de las comunidades autónomas vasca y navarra, se pretende avanzar en el conocimiento de las relaciones entre los centros de Formación Profesional y las empresas. Se prestará especial atención a las nuevas formas de relación entre ambos agentes (especialmente la formación continua), y al efecto que la colaboración con los centros de FP pueda tener sobre los procesos de innovación de las empresas. Se muestra que, en la actualidad, las actividades de formación continua constituyen una forma de colaboración importante para las empresas y estratégica desde el punto de vista del ajuste entre el sistema de formación y el sistema de innovación.
Las relaciones de las empresas con las universidades: estrategias y dinámicas del proceso de cooperación a nivel regional
Authors: Merchán Hernández Carmen
Published: March 2012

Este artículo analiza las dinámicas que tiene el tejido empresarial de una región para relacionarse con las universidades y explora cómo se desarrollan estos procesos de cooperación. Este análisis se realiza a partir de los datos de una encuesta realizada a una muestra representativa de empresas de base tecnológica del sistema regional de innovación de Andalucía. Los resultados señalan que entre las empresas que cooperan con las universidades la estrategia más extendida se centra en el desarrollo de relaciones menos intensivas en la generación y uso del conocimiento científico, basadas en actividades de recursos humanos. Estas empresas siguen unas pautas más informales en el desarrollo de sus relaciones con las universidades. Sin embargo, un sector reducido del tejido empresarial de la región muestra una estrategia de relación caracterizada por el desarrollo de una mayor diversidad de actividades con las universidades, que implican más intensidad de generación y uso de conocimiento científico a través de cauces más formales para llevar a cabo el proceso de cooperación. El artículo explora los factores que influyen en los modelos de relación universidad-empresa y resalta las implicaciones de los resultados para los sistemas regionales de innovación.
Fuentes de conocimiento en los procesos de innovación empresarial: las spin-off universitarias en Andalucía
Authors: Valmaseda Oihana , Hernández Nuria
Published: March 2012

El presente trabajo explora la estrategia de adquisición de conocimiento de las spin-off universitarias, en el marco de la discusión teórica sobre la concurrencia de distintas fuentes de conocimiento en la estrategia tecnológica e innovadora de las empresas. La base empírica de esta investigación la constituye una encuesta a la población de empresas creadas en el sistema universitario andaluz. La investigación permite observar que, en sus procesos de innovación, las empresas estudiadas combinan el conocimiento que se deriva de la realización de I+D interna con el adquirido a través de su relación con agentes externos. En la literatura sobre innovación, existe cierta carencia de estudios empíricos que usen como unidad de análisis a las empresas spin-off. Por ello, los resultados de este trabajo ofrecen interés para este campo científico y también importantes implicaciones en el ámbito de las políticas públicas de innovación.
Harvest Distribution and Derivation of Atlantic Flyway Canada Geese
Authors: Klimstra Jon D. , Padding Paul I.
Published: March 2012

Harvest management of Canada geese Branta canadensis is complicated by the fact that temperate- and subarctic-breeding geese occur in many of the same areas during fall and winter hunting seasons. These populations cannot readily be distinguished, thereby complicating efforts to estimate population-specific harvest and evaluate harvest strategies. In the Atlantic Flyway, annual banding and population monitoring programs are in place for subarctic-breeding (North Atlantic Population, Southern James Bay Population, and Atlantic Population) and temperate-breeding (Atlantic Flyway Resident Population [AFRP]) Canada geese. We used a combination of direct band recoveries and estimated population sizes to determine the distribution and derivation of the harvest of those four populations during the 2004–2005 through 2008–2009 hunting seasons. Most AFRP geese were harvested during the special September season (42%) and regular season (54%) and were primarily taken in the state or province in which they were banded. Nearly all of the special season harvest was AFRP birds: 98% during September seasons and 89% during late seasons. The regular season harvest in Atlantic Flyway states was also primarily AFRP geese (62%), followed in importance by the Atlantic Population (33%). In contrast, harvest in eastern Canada consisted mainly of subarctic geese (42% Atlantic Population, 17% North Atlantic Population, and 6% Southern James Bay Population), with temperate-breeding geese making up the rest. Spring and summer harvest was difficult to characterize because band reporting rates for subsistence hunters are poorly understood; consequently, we were unable to determine the magnitude of subsistence harvest definitively. A better understanding of subsistence hunting is needed because this activity may account for a substantial proportion of the total harvest of subarctic populations. Our results indicate that special September and late seasons in the United States were highly effective in targeting AFRP geese without significantly increasing harvest of subarctic populations. However, it is evident that AFRP geese still are not being harvested at levels high enough to reduce their numbers to the breeding population goal of 700,000.
À propos de la langue et du langage : sensibilisation à la bonne utilisation des dictionnaires
Authors: Greenstein Rosalind
Published: March 2012

Ma pratique de traductrice ainsi que mon expérience de l’enseignement de l’anglais juridique me conduisent depuis plusieurs années à réfléchir à la fois sur les dictionnaires et sur les besoins linguistiques de mes étudiants, dans la perspective de leur future carrière. Le présent article présente l’introduction à mon enseignement et une partie de mes recherches.
Grid, SOA and Cloud Computing
Authors: El-Refaey Mohamed , Rimal Bhaskar Prasad
Published: March 2012

In this chapter we are going to introduce the key concepts of SOA, grid, and cloud computing and the relation between them. This chapter illustrates the paradigm shift in technological services due to the incorporation of these models and how we can combine them to develop a highly scalable application system such as petascale computing. Also there will be coverage for some concepts of Web 2.0 and why it needs grid computing and the on-demand enterprise model. Finally, we will discuss some standardization efforts on these models as a further step in developing interoperable grid systems.
Resource Co-Allocation in Grid Computing Environments
Authors: Netto Marco A.S. , Buyya Rajkumar
Published: March 2012

One of the promises of Grid Computing is to enable the execution of applications across multiple sites. Several multi-site applications require simultaneous access to resources hosted on autonomous domains; this problem is known as resource co-allocation. Projects working on resource co-allocation face four major problems: distributed transactions, fault tolerance, inter-site network overhead, and schedule optimization. Although resource co-allocation is fundamental for Grid Computing, no survey has covered the current projects, solutions, and open challenges on this topic. Therefore, in this chapter, the authors describe the challenges on resource co-allocation, present the projects developed over the last decade, and classify them according to their similar characteristics. In addition, the authors discuss open research issues and trends such as negotiation, advance reservations, and rescheduling of multi-site applications.
Parallel, Distributed, and Grid-Based Data Mining
Authors: HajHmida Moez Ben , Congiusta Antonio
Published: March 2012

Knowledge discovery has become a necessary task in scientific, life sciences, and business fields, both for the growing amount of data being collected and for the complexity of the analysis that need to be performed on it. Classic data mining techniques, developed for centralized sites, often reveal themselves inadequate, due to some unique characteristics of today’s data sources. In such cases, sequential approaches to data mining cannot provide for scalability, in terms of the data dimensionality, size, and runtime performance. Moreover, the increasing trend towards decentralized business organizations, distribution of users, software, and hardware systems magnifies the need for more advanced and flexible approaches and solutions. Life science is one of the application areas that best resemble such scenario. This chapter presents the state of the art about the major data mining techniques, systems and approaches. A detailed taxonomy is drawn by analyzing and comparing parallel, distributed and Grid-based data mining methods, with a particular focus on the exploitation of large and remotely dispersed datasets and/or high-performance computers.
Pervasive Grid and its Applications
Authors: Chang Ruay-Shiung , Chang Jih-Sheng
Published: March 2012

With the advancements of computer system and communication technologies, Grid computing can be seen as the popular technology bringing about significant revolution for the next generation distributed computing application. As regards general users, a grid middleware is complex to setup and necessitates a steep learning curve. How to access to the grid system transparently from the point of view of users turns into a critical issue then. Therefore, various challenges may arise from the incomprehensive system design as coordinating existing computing resources for the sake of achieving pervasive grid environment. The authors are going to investigate into the current research works of pervasive grid as well as analyze the most important factors and components for constructing a pervasive grid system here. Finally, in order to facilitate the efficiency in respect of teaching and research within a campus, they would like to introduce their pervasive grid platform.
Grid Access Control Models and Architectures
Authors: Gouglidis Antonios , Mavridis Ioannis
Published: March 2012

In recent years, grid computing has become the focal point of science and enterprise computer environments. Access control in grid computing systems is an active research area given the challenges and complex applications. First, a number of concepts and terminology related to the area of grid access control are provided. Next, an analysis of the Role Based Access Control (RBAC) and Usage Control ABC (UCONABC) models is given, due to their adaption from the grid computing systems. Additionally, a presentation of well known grid access control architectures illustrates how the theoretical access control models are implemented into mechanisms. In a comparative review of the examined access control models and mechanisms, their pros and cons are exposed. Apart from the mapping of the access control area in grid computer systems, the given comparison renders valuable information for further advancement of current approaches.
Design of SOA based Framework for Collaborative Cloud Computing in Wireless Sensor Networks
Authors: Patel S. V. , Pandey Kamlendu
Published: March 2012

WSN deployments are growing at a fast rate; however, current WSN architectures and setup do not promote the sharing of data on an inter-WSN basis. Cloud computing has emerged as a promising area to deal with participatory and collaborative data and services, and is envisaged that collaborative cloud computing WSN could be a viable solution for sharing data and services for WSN applications. In this paper, SOA based architecture has been proposed to support collaborating cloud computing in WSN. The architecture consists of layered service stack that has management, information, presentation and communication layers with all required services and repositories. Interactions between WSN, subscribers and other cloud are also presented as sequence diagrams. The proposed framework serves the cloud subscribers with wide range of queries on the data of multiple WSNs through suitable interface to solve large scale problems.
An Architectural Overview of the GRelC Data Access Service
Authors: Fiore Sandro , Negro Alessandro , Vadacca Salvatore , Cafaro Massimo , Aloisio Giovanni , Barbera Roberto , Giorgio Emidio
Published: March 2012

Grid computing is an emerging and enabling technology allowing organizations to easily share, integrate and manage resources in a distributed environment. Computational Grid allows running millions of jobs in parallel, but the huge amount of generated data has caused another interesting problem: the management (classification, storage, discovery etc.) of distributed data, i.e., a Data Grid specific issue. In the last decade, many efforts concerning the management of data (grid-storage services, metadata services, grid-database access and integration services, etc.) identify data management as a real challenge for the next generation petascale grid environments. This work provides an architectural overview of the GRelC DAS, a grid database access service developed in the context of the GRelC Project and currently used for production/tutorial activities both in gLite and Globus based grid environments.
Dynamic Dependent Tasks Assignment for Grid Computing
Authors: Meddeber Meriem , Yagoubi Belabbas
Published: March 2012

A computational grid is a widespread computing environment that provides huge computational power for large-scale distributed applications. One of the most important issues in such an environment is resource management. Task assignment as a part of resource management has a considerable effect on the grid middleware performance. In grid computing, task execution time is dependent on the machine to which it is assigned, and task precedence constraints are represented by a directed acyclic graph. This paper proposes a hybrid assignment strategy of dependent tasks in Grids which integrate static and dynamic assignment technologies. Grid computing is considered a set of clusters formed by a set of computing elements and a cluster manager. The main objective is to arrive at a method of task assignment that could achieve minimum response time and reduce the transfer cost, inducing by the tasks transfer respecting the dependency constraints.
Context Related Software Under Ubiquitous Computing
Authors: Rao N. Raghavendra
Published: March 2012

The advancements in information and communication technology (ICT) have resulted in the new concepts being developed in this discipline. Ubiquitous and pervasive computing are among the number of other concepts provided by the ICT. Especially these concepts are providing scope for radical changes in business processes of organizations. It would become a necessity for integrating business with these concepts to face the new realities in business process in organizations. This chapter describes the historical background of commerce in electronic environment, the concepts related to context computing, ubiquitous computing and pervasive computing, and Grid computing. Further it explains the recent trends and also talks about the three business models with these concepts incorporated in three different contexts.
Implementing Geospatial Web Services for Cloud Computing
Authors: Hobona Gobe , Jackson Mike , Anand Suchith
Published: March 2012

Cloud computing is concerned with the provision of hardware, infrastructure, software and data as services on the internet. A key attraction of cloud computing is that the infrastructure from which services are offered is able to scale upwards automatically as the load on the services increases. This chapter examines the potential for offering capabilities of the Geographic Resources Analysis Support System (GRASS) as a service within a compute cloud. GRASS is a free and open source desktop Geographic Information System (GIS). The chapter describes a prototype service that adopts the Web Processing Service (WPS) standard of the Open Geospatial Consortium (OGC). A case study is presented applying the prototype in the analysis of satellite imagery. The chapter concludes that the WPS standard can facilitate the provision of geospatial capability in compute clouds.
Model-Driven Automated Error Recovery in Cloud Computing
Authors: Sun Yu , White Jules , Gray Jeff , Gokhale Aniruddha
Published: March 2012

Cloud computing provides a platform that enables users to utilize computation, storage, and other computing resources on-demand. As the number of running nodes in the cloud increases, the potential points of failure and the complexity of recovering from error states grows correspondingly. Using the traditional cloud administrative interface to manually detect and recover from errors is tedious, time-consuming, and error prone. This chapter presents an innovative approach to automate cloud error detection and recovery based on a run-time model that monitors and manages the running nodes in a cloud. When administrators identify and correct errors in the model, an inference engine is used to identify the specific state pattern in the model to which they were reacting, and to record their recovery actions. An error detection and recovery pattern can be generated from the inference and applied automatically whenever the same error occurs again.
Power Aware Meta Scheduler for Adaptive VM Provisioning in IaaS Cloud
Authors: Jeyarani R. , Nagaveni N. , Sadasivam Satish Kumar , Rajarathinam Vasanth Ram
Published: March 2012

Cloud Computing provides on-demand access to a shared pool of configurable computing resources. The major issue lies in managing extremely large agile data centers which are generally over provisioned to handle unexpected workload surges. This paper focuses on green computing by introducing Power-Aware Meta Scheduler, which provides right fit infrastructure for launching virtual machines onto host. The major challenge of the scheduler is to make a wise decision in transitioning state of the processor cores by exploiting various power saving states inherent in the recent microprocessor technology. This is done by dynamically predicting the utilization of the cloud data center. The authors have extended existing cloudsim toolkit to model power aware resource provisioning, which includes generation of dynamic workload patterns, workload prediction and adaptive provisioning, dynamic lifecycle management of random workload, and implementation of power aware allocation policies and chip aware VM scheduler. The experimental results show that the appropriate usage of different power saving states guarantees significant energy conservation in handling stochastic nature of workload without compromising the performance, both when the data center is in low as well as moderate utilization.
Using Free Software for Elastic Web Hosting on a Private Cloud
Authors: Kübert Roland , Katsaros Gregory
Published: March 2012

Even though public cloud providers already exist and offer computing and storage services, cloud computing is still a buzzword for scientists in various fields such as engineering, finance, social sciences, etc. These technologies are currently mature enough to leave the experimental laboratory in order to be used in real-life scenarios. To this end, the authors consider that the prime example use case of cloud computing is a web hosting service. This paper presents the architectural approach as well as the technical solution for applying elastic web hosting onto a private cloud infrastructure using only free software. Through several available software applications and tools, anyone can build their own private cloud on top of a local infrastructure and benefit from the dynamicity and scalability provided by the cloud approach.
Molecular Structure Determination on the Grid
Authors: Miller Russ , Weeks Charles
Published: March 2012

Grids represent an emerging technology that allows geographically- and organizationally-distributed resources (e.g., computer systems, data repositories, sensors, imaging systems, and so forth) to be linked in a fashion that is transparent to the user. The New York State Grid (NYS Grid) is an integrated computational and data grid that provides access to a wide variety of resources to users from around the world. NYS Grid can be accessed via a Web portal, where the users have access to their data sets and applications, but do not need to be made aware of the details of the data storage or computational devices that are specifically employed in solving their problems. Grid-enabled versions of the SnB and BnP programs, which implement the Shake-and-Bake method of molecular structure (SnB) and substructure (BnP) determination, respectively, have been deployed on NYS Grid. Further, through the Grid Portal, SnB has been run simultaneously on all computational resources on NYS Grid as well as on more than 1100 of the over 3000 processors available through the Open Science Grid.
Grid Computing in 3D Electron Microscopy Reconstruction
Authors: Bilbao-Castro J.R. , García I. , Fernández J.J.
Published: March 2012

Three-dimensional electron microscopy allows scientists to study biological specimens and to understand how they behave and interact with each other depending on their structural conformation. Electron microscopy projections of the specimens are taken from different angles and are processed to obtain a virtual three-dimensional reconstruction for further studies. Nevertheless, the whole reconstruction process, which is composed of many different subtasks from the microscope to the reconstructed volume, is not straightforward nor cheap in terms of computational costs. Different computing paradigms have been applied in order to overcome such high costs. While classic parallel computing using mainframes and clusters of workstations is usually enough for average requirements, there are some tasks which would fit better into a different computing paradigm – such as grid computing. Such tasks can be split up into a myriad of subtasks, which can then be run independently using as many computational resources as are available. This chapter explores two of these tasks present in a typical three-dimensional electron microscopy reconstruction process. In addition, important aspects like fault-tolerance are widely covered; given that the distributed nature of a grid infrastructure makes it inherently unstable and difficult to predict.
A Survey of Cloud Computing Challenges from a Digital Forensics Perspective
Authors: Carlton Gregory H. , Zhou Hill
Published: March 2012

Computing and communication technologies have merged to produce an environment where many applications and their associated data reside in remote locations, often unknown to the users. The adoption of cloud computing promises many benefits to users and service providers, as it shifts users’ concerns away from the physical location of system components and toward the accessibility of the system’s services. While this adoption of cloud computing may be beneficial to users and service providers, it increases areas of concern for computer forensic examiners that need to obtain data from cloud computing environments for evidence in legal matters. The authors present an overview of cloud computing, discuss the challenges it raises from a digital forensics perspective, describe suitable tools for forensic analysis of cloud computing environments, and consider the future of cloud computing.
Cultural Differences in Managing Cloud Computing Service Level Agreements
Authors: Balduf Stefan , Balke Tina , Eymann Torsten
Published: March 2012

Software as a service and cloud computing are new buzzwords in the Internet-based economy. Their idea is to provide software, computing and storage capacity in large, but yet unknown numbers. The legal basis of offering such services is provided by service level agreements (SLAs). In a global economy, these SLAs are often made between companies based in different countries, thus between individuals with different cultural backgrounds. This study explains to what extent, how and why the management of SLAs may differ due to cultural differences among participants. Starting from Hofstede’s seminal work, expert interviews show that some of his findings still hold in the cloud computing world, while others have to be revised.
Exploiting P2P and Grid Computing Technologies for Resource Sharing to Support High Performance Distributed System
Authors: Han Liangxiu
Published: March 2012

This chapter identifies challenges and requirements for resource sharing to support high performance distributed Service-Oriented Computing (SOC) systems. The chapter draws attention to two popular and important design paradigms: Grid and Peer-to-Peer (P2P) computing systems, which are evolving as two practical solutions to supporting wide-area resource sharing over the Internet. As a fundamental task of resource sharing, the efficient resource discovery is playing an important role in the context of the SOC setting. The chapter presents the resource discovery in Grid and P2P environments through an overview of related systems, both historical and emerging. The chapter then discusses the exploitation of both technologies for facilitating the resource discovery within large-scale distributed computing systems in a flexible, scalable, fault-tolerant, interoperable and security fashion.
How to Choose the Right Cloud
Authors: Bibi Stamatia , Katsaros Dimitrios , Bozanis Panayiotis
Published: March 2012

Cloud computing is a recent trend in IT that moves computing and data away from desktop and portable PCs into large data centers, and outsources the “applications” (hardware and software) as services over the Internet. Cloud computing promises to increase the velocity with which applications are deployed, increase innovation, and lower costs, all while increasing business agility. But, is the migration to the Cloud the most profitable option for every business? This chapter presents a study of the basic parameters for estimating the potential infrastructure and software costs deriving from building and deploying applications on cloud and on-premise assets. Estimated user demand and desired quality attributes related to an application are also addressed in this chapter as they are aspects of the decision problem that also influence the choice between cloud and in-house solutions.
Quality of Cloud Services
Authors: Weisbecker Anette
Published: March 2012

Cloud Computing has become the predominant paradigm in information technology for the use of distributed resources. It enables the Internet of Services where different provider offer services and compose services to new value added services. For the emerging service value chains the quality the services plays an important role. Therefore, beside software engineering methods aspects like quality of services, business models, and the interaction with the customer have to be considered during the development of cloud services. This chapter describes how these aspects can be integrated in the development process by combining software and service engineering methods and considering quality as a critical success factor in the design time.
Cloud Computing in Higher Education
Authors: Sasikala P.
Published: March 2012

Cloud Computing promises novel and valuable capabilities for computer users and is explored in all possible areas of information technology dependant fields. However, the literature suffers from hype and divergent definitions and viewpoints. Cloud powered higher education can gain significant flexibility and agility. Higher education policy makers must assume activist roles in the shift towards cloud computing. Classroom experiences show it is a better tool for teaching and collaboration. As it is an emerging service technology, there is a need for standardization of services and customized implementation. Its evolution can change the facets of rural education. It is important as a possible means of driving down the capital and total costs of IT. This paper examines and discusses the concept of Cloud Computing from the perspectives of diverse technologists, cloud standards, services available today, the status of cloud particularly in higher education, and future implications.