bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of Suppression and Enhancement of Photocurrent/Conversion Efficiency in Dye-Sensitized Solar-Cells Using Carotenoid and Chlorophyll Derivatives as Sensitizers
Authors: Koyama Yasushi , Kakitani Yoshinori , Nagae Hiroyoshi
Published: February 2012

The mechanisms of suppression and enhancement of photocurrent/conversion efficiency (performance) in dye-sensitized solar cells, using carotenoid and chlorophyll derivatives as sensitizers, were compared systematically. The key factor to enhance the performance was found to be how to minimize interaction among the excited-state dye-sensitizer(s). In a set of retinoic-acid (RA) and carotenoic-acid (CA) sensitizers, having n conjugated double bonds, CA7 gave rise to the highest performance, which was reduced toward RA5 and CA13. The former was ascribed to the generation of triplet and the resultant singlet-triplet annihilation reaction, while the latter, to the intrinsic electron injection efficiency. In a set of shorter polyene sensitizers having different polarizabilities, the one with the highest polarizability (the highest trend of aggregate formation) exhibited the higher performance toward the lower dye concentration and the lower light intensity, contrary to our expectation. This is ascribed to a decrease in the singlet-triplet annihilation reaction. The performance of cosensitization, by a pair of pheophorbide sensitizers without and with the central metal, Mg or Zn, was enhanced by the light absorption (complementary rather than competitive), the transition-dipole moments (orthogonal rather than parallel) and by the pathways of electron injection (energetically independent rather than interactive).
Benefits of Combinations of Vitamin A, C and E Derivatives in the Stability of Cosmetic Formulations
Authors: Gianeti Mirela Donato , Gaspar Lorena Rigo , Bueno de Camargo Júnior Flávio , Berardo Gonçalves Maia Campos Patrícia Maria
Published: February 2012

Chemically stable ester derivatives of vitamins A, C and E have become a focus of interest for their role in the satisfactory results in skin aging treatments. Accordingly, the aim of this study was to evaluate the physical and chemical stability of a cosmetic formulation containing 1% retinyl palmitate, ascorbyl tetraisopalmitate and tocopheryl acetate, alone or in combination. In the studies of physical stability, a Brookfield rheometer was used to determine rheological behavior of formulations containing the vitamins. Chemical stability was determined by HPLC on a Shimadzu system with UV detection. Results showed that formulations had pseudoplastic behavior and that vitamins did not alter their apparent viscosity and thixotropy. In the chemical stability studies, first-order reaction equations were used for determinations of the shelf-life of vitamins derivatives considering a remaining concentration of 85%. Combined vitamins in a single formulation had a slightly lower degradation rate as compared to different preparations containing only one of the vitamins. Considering that many cosmetic formulations contain vitamin combinations it is suggested that the present study may contribute to the development of more stable formulations containing liposoluble vitamins.
Les enclos laténiens sont-ils toujours des fermes ?
Authors: Malrain François , Blondiau Lydie , Chaidron Cyrille , Auxiette Ginette , Legros Vincent , Pinard Estelle
Published: February 2012

Ziel ist es, von einigen Beispielen ausgehend, die Debatte über die Funktion der latènezeitlichen Umfriedungen zu beleben. Wenn eine Fundstätte eine Umfriedung aufweist, deren Gräben Gebäude und Strukturen umgeben, wird in den meisten Fallen eine landwirtschaftliche Funktion vorgeschlagen. Nun scheint es aber, dass diese Funktion nicht immer ausschliefilich zutrifft, und dass sie in einigen Fallen sogar ausgeschlossen werden kann. Folglich ist es angemessen, sich um neue Interpretierungen zu bemuhen, um versuchen der Vielf alt der gallischen Siedlungsstrukturen besser gerecht zu werden.
La parure de la sépulture féminine 43 de Vron (Somme)
Authors: Welch Martin
Published: February 2012

L’ensemble d’objets signalés entre 1950 et 1960 comme provenant de la tombe 43 de Vron a une réelle importance, du fait qu’il comporte une paire de fibules assorties se rattachant à une tradition caractéristique

du Sud de la Scandinavie (type des fibules du Jutland de Haseloff, groupes B et C). Les deux fibules, ainsi que la

tête de fourreau de couteau associée, ont un décor moulé animalier (ou humano-animalier) dans le style 1 de

Salin, et l’on peut proposer pour leur fabrication une fourchette se situant dans le premier tiers du VIe siècle.

Elles pourraient être attribuées à un atelier du Kent où travaillait un orfèvre venu de Scandinavie, mais elles pourraient aussi bien avoir été exportées depuis la région du Jutland. La comparaison géographiquement la plus proche est avec la fibule de la tombe 10 de Saint-Brice (Tournai, Belgique), qui renvoie aussi à la tombe 14 d’Apple Down (Compton, Ouest Sussex). Il est regrettable qu’ait survécu seulement un petit nombre des perles de verre de ce qui était probablement un ou des colliers, et que cet important ensemble funéraire du VIe siècle n’ait pas été mieux enregistré. Au total, il convient de signaler que l’ensemble de Vron, avec son caractère typiquement scandinave, se différencie des autres exportations d’objets métalliques fabriqués dans le Kent au VIe siècle, incluant les fibules cupelliformes et les petites fibules à tête rectangulaire que l’on retrouve dans de nombreuses nécropoles au niveau des régions côtières septentrionales de la France, du Cotentin à l’Ouest, à la Belgique à l'Est.
THE MATHEMATICAL MODELLING OF LINER MOVEMENT IN A MAGNETIC COMPRESSOR: ELASTIC, LIQUID AND PLASTIC LINER MODELS COMPARISON
Authors: Galanin Michail , Lototsky Aleksey , Rodin Alexander
Published: February 2012

The paper is aimed to model the electromagnetic acceleration and braking of the liner in magnetic compressor. The 2D approach corresponding to the longitudinal section of spatial region is considered. Liquid, elastic, and plastic models of the liner are presented. The comparative analysis of calculation results for different models and their correlation with experimental data are carried out. The research of the influence of circuit parameters on liner braking is done.
ON SOME SPECTRAL PROPERTIES OF THIRD ORDER NONLINEAR BOUNDARY VALUE PROBLEMS
Authors: Smirnov Sergey
Published: February 2012

The present paper deals with a two point the third-order nonlinear boundary value problem. An estimation of the number of solutions to boundary value problem and their nodal structure are established. Some results are given on spectral properties of solutions.
Advancing the Evidence Base for a Standardized Provider Handover Structure: Using Staff Nurse Descriptions of Information Needed to Deliver Competent Care
Authors: Adams Jeffrey M. , Osborne-McKenzie Tanya
Published: February 2012

Using existing gold standard structures to manage “handover” was a conceptual communication challenge for nurses involved in critically important shift-to-shift transitions in this study, which was conducted at a Central Coast California District Hospital. An extensive body of literature identifies poor communication as jeopardizing patient safety, quality, and continuity of care. Researchers who used the prevailing structures, Situation-Background-Assessment-Recommendation (SBAR), used by the World Health Organization (WHO), and the Communication During Patient Handover (CDPH), sanctioned by The Joint Commission (TJC), had difficulty categorizing content described by nurses as necessary to the delivery of competent care. This article describes a study that resulted in an alternative structure for handover, D-BANQ, which aligns with prevailing WHO-SBAR and TJC-CDPH handover structures and provides an easy-to-follow chronological format for the content that nurses identified as necessary to communicate during this important nursing activity.
Women, Big Ideas, and Social Networking Technologies
Authors: Wei Zhang , Kramarae Cheris
Published: February 2012

The assumption that women are not capable of generating big ideas is entrenched in the mainstream consciousness and may appear in many guises. In the current mainstream discourse on women’s use of social networking technologies, similar assumptions implicitly presuppose that, compared with men’s use of the new social networking technologies, women’s ideas and activities on the social Web are deficient and less serious. To open further the conversation about women’s empowerment on the social Web and enhance feminist global collaborations using new social networking technologies, the authors problematize seven hidden assumptions in both the academic and popular discourse about women’s ideas, interests, and practices on the social Web and raise more questions about women, ideas, and social networking technologies. The analysis reveals that until gendered assumptions about women’s ideas and social networking are examined, digital inequities cannot be adequately addressed.
From Drift to Draft
Authors: Radu Roxana Georgiana
Published: February 2012

The global digital divide, denoting the patterns of uneven distribution of information and communication technologies (ICTs) worldwide, emerged as a constant concern during the last two decades. Going beyond the minimal requirements of physical connectivity, it points to an underlying concern of digital inclusion differentials of citizens in developing countries, the so-called “information poor.” This chapter aims at addressing this with reference to the international institutional structures and their current efforts. After assessing the categories of people that are affected the most by the digital gap and the range of opportunities available to them in the context of globalization, special attention will be given to the overlapping concerns shaping the international agenda with regard to ICT adoption. The creation of international bodies such as Sustainable Development Networking Programme (SDNP), Digital Opportunity Taskforce (DOT), and Information for Development Program (InfoDev) will be discussed together with the redefinition of the digital access problem as a ”universal service” and the emergence of specific endeavors for reducing global digital inequalities.
User Perceptions of Information Quality in E-Learning Systems
Authors: Alkhattabi Mona , Neagu Daniel , Cullen Andrea
Published: February 2012

With the prevalent use of e-learning systems as an information exchange means, the need for quality published materials within these systems has become vital. In previous work by the authors, an information quality framework for e-learning systems was developed. The proposed framework consisted of 14 quality attributes grouped in three quality factors: intrinsic, contextual representation and accessibility. Within the proposed quality framework, the authors assigned a relative importance weight for each attribute within the main quality factors, and a relative importance weight for each factor in the overall quality score. The idea of using relative importance as a parameter for the measurement is important, since it provides the framework with the flexibility to be adopted and used in different e-learning environments and with different users. The importance weights could be updated if a quality attribute or factor appeared to have the same significant value for the quality assessment no longer. This study examines whether any significant gender and cultural related differences exist in user perceptions of the relative importance of the main quality factors within the proposed framework. Reported results are based on the collection of original questionnaire data and t-test analysis supporting the conclusions.
Re-Examining the Career Anchor Model
Authors: Quesenberry Jeria L.
Published: February 2012

Despite the shortage of information technology (IT) professionals in the global economy, women are largely underrepresented in the IT workforce. Prior research on gender stratification demonstrates that this underrepresentation is a reflection of organizational and social structures. As a result, it is necessary to understand the characteristics of the IT workforce, and in particular, the opportunities and constraints that influence career choice of IT professionals. For these reasons, the purpose of this chapter is to examine the career anchors of women in the American IT workforce. The data for this examination comes from a quantitative survey conducted with 210 women. The findings make a theoretical contribution to the career anchor research of women in the IT workforce.
Implement VoIP Based IP Telephony with Open Source Asterisk Architecture
Authors: Gohel Chirag K. , Lakhtaria Kamaljit I.
Published: February 2012

Asterisk is a leading open source telephony software/system, easily implemented over intranet and internet. Asterisk empowers developers and integrators to create advanced communication solutions. An Asterisk system is a low cost type of a traditional PBX system. Any phone controlled by an Asterisk system can call a VoIP or analog phone controlled or managed by a traditional telephone system or by Asterisk telephone system. In this paper, the authors focus on the deployment and testing of various Open Source Asterisk Services in an enterprise level communication system. Selected services are listed in this paper that can be used to implement a telephone system with good Quality of Services (QoS) and good Quality of Experience (QoE) from the personal user to enterprise level users.
Second Life
Authors: Grimes Galen , Bartolacci Michael
Published: February 2012

Virtual worlds have become increasingly popular with the growth of high speed Internet access worldwide and online gaming. The popularity of massively multiplayer online role playing games (MMORPG), such as World of Warcraft, and virtual worlds, such as Second Life, has created an opportunity for educators to build a learning platform that students can readily relate to. This paper explores some of the possibilities of utilizing one particular virtual world (Second Life) as a platform for network and information security training with a focus on the profiling of online behavior. In particular it describes the initial attempts of its use at one of the Pennsylvania State University’s campuses.
Technology and the Preschooler
Authors: Lennex Lesia , Nettleton Kimberely Fletcher , Murphy Nikita
Published: February 2012

More and more, schools are purposefully utilizing technology in the classroom for learning. As the technology era expands, the age of those interacting with technology seems to be shrinking. Can children in preschool benefit from the use of instructional technology? Children are highly adaptable and learn at faster rates than adults. Their brains are wired for increased synthesis of complex operations such as speech acquisition and even technology. In what way(s) would they best learn from technology? What learning behaviors could help shape preschool curriculum? Examination of how students explore, navigate, and interact with technologies provides direction for best practices in teaching.
Making and Thinking Movies in the Science Classroom
Authors: Angelone Lauren
Published: February 2012

Making movies in the science classroom can be an engaging way to teach and assess science content understanding, but it can also be a way to encourage students to be critical of the media that is becoming more and more a part of their everyday lives. In this chapter, the author describes a sample inquiry-based project in which students created movies to learn science content. Background is given on classroom management, materials, movie-making basics, and assessment. The project is also framed by critical media literacy, which keeps in mind not only the messages that media products can send, but the messages the tools themselves may also send. In this way, students and teachers not only make movies, but think movies in the science classroom.
Spectrum Handover Strategies for Cognitive Femtocell Networks
Authors: Al-Rubaye Saba , Al-Dulaimi Anwer , Cosmas John
Published: February 2012

Cognitive femtocell is a promising technology for the next generation wireless networks to improve the efficiency of spectrum utilization, coverage, and to attain higher data rates for indoor communications. In this chapter, the new Cognitive Femtocell Switching Unit (CFSU) is proposed to support handover management for 10-20 cognitive femtocells as a local geographical cluster. Thus, CFSU acts as a service coordinator between femtocells and macrocell areas to improve spectrum utilization and coexistence. Then, the chapter presents solutions for spectrum handover to achieve guaranteed quality of radio service, spectrum utilization, and enable an excellent local handover management to reduce unnecessary handovers between femtocell base stations. The challenges and solutions that are presented in this chapter have the ability to maintain services by evaluating the requested quality of services.
Security Management for Mobile Ad Hoc Network of Networks (MANoN)
Authors: Al-Bayatti Ali H. , Zedan Hussein , Cau Antoniuo , Siewe François
Published: February 2012

Many military research efforts have concentrated on how to allow war-fighters to take advantage of all available information within the battlefield in a rapid and flexible manner. As a result, the development of the Global Information Grid (GIG) was the key enabler for this process; hence, adding to the development of the mobile networking part of the GIG, the concept of the Mobile Ad hoc Network of Networks (MANoN) is introduced. This article proposes a novel security management algorithm achieving the three management essentials: Security Administration; Prevention and Detection; and Containment and Recovery; based on the International Telecommunication Union’s recommendation M.3400 to manage securely the future of military Network-Centric Warfare (NCW). The authors will employ Interval Temporal Logic (ITL) as a method of handling both sequential and parallel composition in flexible timely constrains, in addition, this technique will be evaluated using the Network Simulator (NS-2) to provide and check whether security requirements are met in a comprehensive manner.
Building Wireless Sensor Network Applications with LooCI
Authors: Hughes Daniel , Thoelen Klaas , Horré Wouter , Matthys Nelson , Del Cid Javier , Michiels Sam , Huygens Christophe , Joosen Wouter , Ueyama Jó
Published: February 2012

Considerable research has been performed in applying run-time reconfigurable component models to the domain of wireless sensor networks. The ability to dynamically deploy and reconfigure software components has clear advantages in sensor networks, which are typically large in scale and expected to operate for long periods in the face of node mobility, dynamic environmental conditions, and changing application requirements. LooCI is a component and binding model that is optimized for use in resource-constrained environments such as Wireless Sensor Networks. LooCI components use a novel event-based binding model that allows developers to model rich component interactions, while providing support for run-time reconfiguration, reflection, and policy-based management. This paper reports on the design of LooCI and describes a prototype implementation for the Sun SPOT. This platform is then evaluated in context of a real-world river monitoring and warning scenario in the city of São Carlos, Brazil.
End User Development and Meta-Design
Authors: Fischer Gerhard
Published: February 2012

The first decade of the World Wide Web predominantly enforced a clear separation between designers and consumers. New technological developments, such as the participatory Web 2.0 architectures, have emerged to support social computing. These developments are the foundations for a fundamental shift from consumer cultures (specialized in producing finished goods) to cultures of participation (in which all people can participate actively in personally meaningful activities). End-user development and meta-design provide foundations for this fundamental transformation. They explore and support new approaches for the design, adoption, appropriation, adaptation, evolution, and sharing of artifacts by all participating stakeholders. They take into account that cultures of participation are not dictated by technology alone: they are the result of incremental shifts in human behavior and social organizations. The design, development, and assessment of five particular applications that contributed to the development of our theoretical framework are described and discussed.
Entering the Clubhouse
Authors: Kafai Yasmin B. , Fields Deborah , Burke William Q.
Published: February 2012

Previous efforts in end-user development have focused on facilitating the mechanics of learning programming, leaving aside social and cultural factors equally important in getting youth engaged in programming. As part of a 4-month long ethnographic study, we followed two 12-year-old participants as they learned the programming software Scratch and its associated file-sharing site, scratch.mit.edu, in an after-school club and class. In our discussion, we focus on the role that agency, membership, and status played in their joining and participating in local and online communities of programmers.
Enterprise Systems Training Strategies
Authors: Coulson Tony , Olfman Lorne , Ryan Terry , Shayo Conrad
Published: February 2012

Enterprise systems (ESs) are customizable, integrated software applications designed to support core business processes. This paper reports research contrasting the relative effectiveness of two strategies for ES end-user training that differentially reflect the Sein, Bostrom, and Olfman (1999) hierarchical knowledge-level model. One strategy— procedural—involves training that targets the three lowest knowledge levels of the model (command-based, tool-procedural, and business-procedural); the other—tool-conceptual—involves training that also includes a higher knowledge level (tool-conceptual). A non-equivalent quasi-experimental design was used for groups of senior business students being trained to use an authentic ES. Performance measures were administered during training and ten days after training concluded. Both experiments demonstrated that training involving the tool-conceptual knowledge level leads to superior mental models, compared with training oriented toward lower knowledge levels, as expressed in the recollection and communication of ES concepts. Tool-conceptual knowledge-level training can be used to promote understanding and communication, and should be incorporated into training strategies for ES.
A Path Analysis of the Impact of Application-Specific Perceptions of Computer Self-Efficacy and Anxiety on Technology Acceptance
Authors: Hasan Bassam , Ahmed Mesbah U.
Published: February 2012

Perceptions of computer self-efficacy (CSE) and computer anxiety are valuable predictors of various computer-related behaviors, including acceptance and utilization of information systems (IS). Although both factors are purported to have general and application-specific components, little research has focused on the application or system-specific component, especially in IS acceptance contexts. Thus, little is known about the effects of application-specific beliefs on IS acceptance or how such effects compare with the effects of more general CSE and computer anxiety beliefs. Accordingly, a research model comprising application CSE, application anxiety, perceived ease of use, perceived usefulness, attitude, and intention was proposed and tested via path analysis. The results demonstrated that the direct impacts of application CSE and application anxiety on perceived ease of use and perceived usefulness were almost equal, but in opposite directions. However, the indirect effect of application CSE on attitude and intention was stronger than that of application anxiety.
Towards Supporting Interoperability in e-Invoicing Based on Semantic Web Technologies
Authors: Gómez-Pérez José Manuel , Méndez Víctor
Published: February 2012

Since the use of electronic invoicing in business transactions was approved by the EU back in 2002, its application in Europe has grown considerably. However, despite the existence of standards like EDIFACT or UBL, widespread take up of electronic invoicing has been hindered by the enormous heterogeneity of proprietary solutions. In this chapter, the authors present an approach towards addressing the interoperability problem in electronic invoice exchange, based on ontologies and Semantic Web technologies. The authors propose methods and provide usable tools that leverage the knowledge of users of electronic invoicing systems by empowering them to define correspondences between sample electronic invoice data and a formal model of electronic invoicing represented as networked ontologies. The chapter follows a learn-by-example approach where, based on such correspondences, networked ontologies serve as a semantic hub for large-scale transformation of e-invoice data between heterogeneous e-invoicing formats and models. The approach has been evaluated through the development of a reference implementation and its deployment in the pharmaceutical sector.
Distance Learning Challenges Facing Two World Regional Universities
Authors: Sookram Sandra , Hogan Robert
Published: February 2012

The University of the West Indies and the University of the South Pacific are the only two regional universities in the world. Together they serve 29 small island nations spread over nearly 35 percent of the Earth’s surface. Many of these developing countries lack the educational resources to provide the educational access to develop strong economies and improve social conditions. Until recently, regional campuses and correspondence courses were the primary means of course delivery due to isolation and small population sizes. However, improved Internet access at a time of increased shipping and travel costs now makes Transnational Distance Learning (TDL) increasingly attractive. TDL is defined as online learning delivered to students in other countries or even other continents. TDL holds the promise of improving educational access, but there are challenges. This chapter discusses the distance-learning history, current practices, and future directions of these two regional universities. The chapter also discusses opportunities, competition from foreign universities, political issues that impact regional universities, and cultural/pedagogical challenges.
Discrete Event Models for Web Service Processes
Authors: Yan Yuhong , Haydar May
Published: February 2012

Web service processes are business processes composed of individual Web services. Web service process description languages, used in both choreography and orchestration, are influenced by techniques from workflow modeling, formal methods and software engineering. Since such languages are based on software scripts to be executed by a process engine, their expressive power indeed is beyond classic discrete event system models, such as process algebra and Petri nets. This chapter analyzes and compares different Web service process description languages, discusses the issues in using discrete event system models to model Web service processes, and also compares Web service processes with workflow processes. The chapter also discusses the suitable methods based on the formal models for various computing tasks, such as verification and validation.
Tangible Interfaces for Art Restoration
Authors: Bonanni Leonardo , Seracini Maurizio , Xiao Xiao , Hockenberry Matthew , Costanzo Bianca Cheng , Shum Andrew , Teil Romain , Speranza Antony , Ishii Hiroshi
Published: February 2012

Few people experience art the way a restorer does: as a tactile, multi-dimensional and ever-changing object. The authors investigate a set of tools for the distributed analysis of artworks in physical and digital realms. Their work is based on observation of professional art restoration practice and rich data available through multi-spectral imaging. The article presents a multidisciplinary approach to develop interfaces usable by restorers, students and amateurs. Several interaction techniques were built using physical metaphors to navigate the layers of information revealed by multi-spectral imaging, prototyped using single- and multi-touch displays. The authors built modular systems to accommodate the technical needs and resources of various institutions and individuals, with the aim to make high-quality art diagnostics possible on different hardware platforms, as well as rich diagnostic and historic information about art available for education and research through a cohesive set of web-based tools instantiated in physical interfaces and public installations.
Calligraphic Video
Authors: Wei Sha Xin
Published: February 2012

Since 1984, Graphical User Interfaces have typically relied on visual icons that mimic physical objects like the folder, button, and trash can, or canonical geometric elements like menus, and spreadsheet cells. GUI’s leverage our intuition about the physical environment. But the world can be thought of as being made of stuff as well as things. Making interfaces from this point of view requires a way to simulate the physics of stuff in realtime response to continuous gesture, driven by behavior logic that can be understood by the user and the designer. The author argues for leveraging the corporeal intuition that people learn from birth about heat flow, water, smoke, to develop interfaces at the density of matter that leverage in turn the state of the art in computational physics.
Metadata Management in PetaShare Distributed Storage Network
Authors: Akturk Ismail , Wang Xinqi , Kosar Tevfik
Published: February 2012

The unbounded increase in the size of data generated by scientific applications necessitates collaboration and sharing among the nation’s education and research institutions. Simply purchasing high-capacity, high-performance storage systems and adding them to the existing infrastructure of the collaborating institutions does not solve the underlying and highly challenging data handling problem. Scientists are compelled to spend a great deal of time and energy on solving basic data-handling issues, such as the physical location of data, how to access it, and/or how to move it to visualization and/or compute resources for further analysis. This chapter presents the design and implementation of a reliable and efficient distributed data storage system, PetaShare, which spans multiple institutions across the state of Louisiana. At the back-end, PetaShare provides a unified name space and efficient data movement across geographically distributed storage sites. At the front-end, it provides light-weight clients the enable easy, transparent, and scalable access. In PetaShare, the authors have designed and implemented an asynchronously replicated multi-master metadata system for enhanced reliability and availability. The authors also present a high level cross-domain metadata schema to provide a structured systematic view of multiple science domains supported by PetaShare.
Data Intensive Computing with Clustered Chirp Servers
Authors: Thain Douglas , Albrecht Michael , Bui Hoang , Bui Peter , Carmichael Rory , Emrich Scott , Flynn Patrick
Published: February 2012

Over the last few decades, computing performance, memory capacity, and disk storage have all increased by many orders of magnitude. However, I/O performance has not increased at nearly the same pace: a disk arm movement is still measured in milliseconds, and disk I/O throughput is still measured in megabytes per second. If one wishes to build computer systems that can store and process petabytes of data, they must have large numbers of disks and the corresponding I/O paths and memory capacity to support the desired data rate. A cost efficient way to accomplish this is by clustering large numbers of commodity machines together. This chapter presents Chirp as a building block for clustered data intensive scientific computing. Chirp was originally designed as a lightweight file server for grid computing and was used as a “personal” file server. The authors explore building systems with very high I/O capacity using commodity storage devices by tying together multiple Chirp servers. Several real-life applications such as the GRAND Data Analysis Grid, the Biometrics Research Grid, and the Biocompute Facility use Chirp as their fundamental building block, but provide different services and interfaces appropriate to their target communities.
Hepatosplenic Gamma-Delta T-Cell Lymphoma in a Female Patient after Delivery
Authors: Glaser Marjana , Goropevšek Aleš , Kavalar Rajko , Glaser Andrej
Published: February 2012

Hepatosplenic γδ T-cell lymphoma (HSTCL) is a very rare peripheral T-cell lymphoma characterized by extranodal infiltration of mature malignant post-thymic T-lymphocytes into sinusoids of the liver and spleen without lymphadenopathy and significant cytopenias. The aetiology of the disease is unknown. We describe the case of a female patient in whom HSTCL developed after delivery and who was previously without disease. Flow cytometry and liver puncture are essential for diagnosing HSTCL, especially in patients with unexplained pancytopenia and hepatosplenomegaly. Since phenotypic results can easily be misinterpreted as non-malignant, the examiner should have enough experience to recognize clonal changes of T-lymphocytes. Namely, in contrast to B-lymphocytes, T-lymphocytes do not have an efficient indicator of clonality and are recognized by flow cytometry based only on aberrant expression of commonly present antigens of T-cell and NK-cell subsets. At present, there is no known cure for HSTCL with a maximum survival up to 2 years.
Two cases of possible neuro-Sweet disease with meningoencephalitis as the initial manifestation
Authors: Makimoto Go , Manabe Yasuhiro , Yamakawa Chizuru , Fujii Daiki , Ikeda-Sakai Yasuko , Narai Hisashi , Omori Nobuhiko , Abe Koji
Published: February 2012

We report 2 cases that were considered to be neuro-Sweet disease. They initially manifested with meningoencephalitis and no skin lesions, and rapidly improved with corticosteroid therapy. In both cases, patients complained of meningitic symptoms such as fever and headache, and HLA-B54 and -Cw1 turned out to be positive over the clinical course. Cerebrospinal fluid analysis showed increased levels of lymphocytes and protein. In case #1, fluid-attenuated inversion recovery (FLAIR), magnetic resonance imaging (MRI) and diffusion-weighted images (DWI) showed high-intensity signals in the right dorsal medulla oblongata, bilateral dorsal midbrain, and left thalamus. In case #2, FLAIR and DWI showed high-intensity signals in the bilateral cerebellar cortex and left caudate nucleus. Symptoms and MRI images were markedly improved in both cases after corticosteroid pulse therapy. According to published diagnostic criteria, these 2 cases were considered possible neuro-Sweet disease. These cases suggest that the combination of meningoencephalitis and HLA specificity is important to consider the possibility of neuro-Sweet disease, even without skin lesions.
Pulmonary Mantle Cell Lymphoma: A Rare Manifestation of an Uncommon Condition
Authors: DePew Zachary S. , Vassallo Robert
Published: February 2012

Herein we describe the case of a 64-year old man with a history of mantle cell lymphoma found to have evidence of pulmonary parenchymal involvement by recurrence of his lymphoma. While lung involvement is not necessarily uncommon with Non-Hodgkin's lymphomas as a group, it is very rare for mantle cell lymphoma to involve the lung parenchyma. In addition, the radiographic manifestation of his pulmonary lymphoma as a discrete FDG-avid ground-glass lesion on chest imaging was also distinctly uncommon for pulmonary lymphoma which classically appears in one of three patterns: scattered ill-defined nodules, a bronchovascular/lymphangitic process, or pneumonic/alveolar consolidation effectively indistinguishable from bacterial pneumonia. Due to significant underlying lung disease our patient was not a candidate for high-dose conditioning and autologous stem cell transplantation. He was ultimately treated with rituximab and cladribine therapy and had early signs of clinical response at last correspondence.
Global magnetospheric response to an interplanetary shock: THEMIS observations
Authors: Zhang H. , Sibeck D. G. , Zong Q.-G. , McFadden J. P. , Larson D. , Glassmeier K.-H. , Angelopoulos V.
Published: February 2012

Abstract. We investigate the global response of the geospace plasma environment to an interplanetary (IP) shock at ~02:24 UT on 28 May 2008 from multiple THEMIS spacecraft observations in the magnetosheath (THEMIS B and C), the mid-afternoon magnetosphere (THEMIS A), and the dusk magnetosphere (THEMIS D and E). The interaction of the transmitted IP shock with the magnetosphere has global effects. Consequently, it can affect geospace plasma significantly. After interacting with the bow shock, the IP shock transmitted a fast shock and a discontinuity which propagated through the magnetosheath toward the Earth at speeds of 301 km s−1 and 137 km s−1, respectively. THEMIS A observations indicate that the IP shock changed the properties of a plasmaspheric plume significantly. The plasmaspheric plume density increased rapidly from 10 to 100 cm−3 in 4 min and the ion distribution changed from an isotropic to a strongly anisotropic distribution. Electromagnetic ion cyclotron (EMIC) waves observed by THEMIS A are most likely excited by the anisotropic ion distributions caused by the IP shock impact. THEMIS A, but not D or E, observed a plasmaspheric plume in the dayside magnetosphere. Multiple spacecraft observations indicate that the dawn-side edge of the plasmaspheric plume was located between THEMIS A and D (or E).
Prestrain‐Free Dielectric Elastomers Based on Acrylic Thermoplastic Elastomer Gels: A Morphological and (Electro)Mechanical Property Study
Authors: Vargantwar Pruthesh H. , Özçam A. Evren , Ghosh Tushar K. , Spontak Richard J.
Published: February 2012

Recent efforts have established that thermoplastic elastomer gels (TPEGs) composed of styrenic triblock copolymers swollen with a midblock‐selective solvent exhibit remarkable electromechanical properties as high‐performance dielectric elastomers. This class of electroactive polymers typically requires high electric fields for actuation, and a shortcoming that continues to thwart the widespread commercialization of such materials in general is the need to apply mechanical prestrain prior to electroactuation to decrease film thickness and, thus, the electric potential required to promote actuation. To alleviate this requirement, TPEGs consisting of acrylic triblock copolymers differing in molecular weight and composition, and swollen with a high dielectric, midblock‐selective solvent are investigated. Synchrotron small‐angle x‐ray scattering is used to probe the nanoscale morphologies of the resultant materials, and analysis of quasi‐static and cyclic tensile properties provides additional insight into both blend morphologies and electroactuation efficacy. Actuation strains measured in the absence of mechanical prestrain exceed 100% on an area basis, and electric fields capable of inducing actuation are as low as ∼20 kV/mm. Failure occurs by either electromechanical instability or dielectric breakdown, depending on the copolymer and TPEG composition employed. The electromechanical properties of these acrylic‐based TPEGs match or exceed those of skeletal muscle, in which case they constitute an attractive and unexplored alternative to existing dielectric elastomers.
The Origin of Magnetism in Mn‐Doped SrTiO3
Authors: Valant Matjaz , Kolodiazhnyi Taras , Arčon Iztok , Aguesse Frederic , Axelsson Anna‐Karin , Alford Neil M.
Published: February 2012

An analysis of Mn substitution in SrTiO3 is performed in order to understand the origin of reported spin coupling in lightly Mn‐doped SrTiO3. The spin glass state magnetoelectrically coupled to the dipolar glass state has previously been reported for SrTiO3 substituted with only 2% of Mn on the B‐site. An analysis of the substitution mechanism for A‐ and B‐site doping shows a strong influence of processing conditions, such as processing temperature, oxygen partial pressure, and off‐stoichiometry. The required conditions for a site‐selective substitution are defined, which yield a single‐phase and almost defect‐free perovskite. Magnetic measurements show no magnetic anomalies resulting from spin coupling and only a simple paramagnetic behavior. Magnetic anomalies are observed only for the samples in which Mn is misplaced within the cation sublattice of the SrTiO3 perovskite. This occurs due to improper material processing, which causes initially unpredicted changes in the valence state of the Mn and results in the formation of structural defects and irregularities associated with segregation and nucleation of the magnetic species. Previously reported spin coupling in Mn‐doped SrTiO3 is not an intrinsic phenomenon and cannot be treated as a spin glass.
Chemometric methods to classify stationary phases for achiral packed column supercritical fluid chromatography
Authors: West Caroline , Lesellier Eric
Published: February 2012

This paper investigates classification models for packed columns used in supercritical fluid chromatography (SFC). Forty‐eight columns of varied stationary phase chemistries available on the market are evaluated. The retention factors of 134 selected test compounds are used to compute hierarchical cluster analysis (HCA), principal component analysis (PCA), and quantitative structure–retention relationships (QSRRs). The use of HCA in conjunction with either PCA of QSRRs provides a classification of columns that is consistent with the experience of the SFC chromatographer. Besides, different coefficients, namely, Pearson correlation coefficient (r), selectivity difference (s2), distance (L), and angle (θ), were calculated between all couples of columns to identify a ranking index, which would provide meaningful information whenever two columns need to be compared on an objective basis. This can be the case either when an equivalent is sought for replacement of a reference column or when an orthogonal column is desired to achieve complementary selectivity. It is concluded that the θ angle and the normalized distance L/u are the best coefficients, allowing for a meaningful comparison between two columns. Copyright © 2012 John Wiley & Sons, Ltd.
Dihydrogen Generation from Amine/Boranes: Synthesis, FT‐ICR, and Computational Studies
Authors: Abboud José‐Luis M. , Németh Balázs , Guillemin Jean‐Claude , Burk Peeter , Adamson Aiko , Nerut Eva Roos
Published: February 2012

A Fourier transform ion cyclotron resonance spectrometry (FT‐ICR) study of the gas‐phase protonation of ammonia‐borane and sixteen amine/boranes R1R2R3NBH3(including six compounds synthesized for the first time) has shown that, without exception, the protonation of amine/boranes leads to the formation of dihydrogen. The structural effects on the experimental energetic thresholds of this reaction were determined experimentally. The most likely intermediate and the observed final species (besides H2) are R1R2R3NBH4+and R1R2R3NBH2+, respectively. Isotopic substitution allowed the reaction mechanism to be ascertained. Computational analyses ([MP2/6‐311+G(d,p)] level) of the thermodynamic stabilities of the R1R2R3NBH3adducts, the acidities of the proton sources required for dihydrogen formation, and the structural effects on these processes were performed. It was further found that the family of R1R2R3NBH4+ions is characterized by a three‐center, two‐electron bond between B and a loosely bound H2molecule. Unexpected features of some R1R2R3NBH4+ions were found. This information allowed the properties of amine/boranes most suitable for dihydrogen generation and storage to be determined.
Tetrachlorinated Tetraazaperopyrenes (TAPPs): Highly Fluorescent Dyes and Semiconductors for Air‐Stable Organic n‐Channel Transistors and Complementary Circuits
Authors: Martens Susanne C. , Zschieschang Ute , Wadepohl Hubert , Klauk Hagen , Gade Lutz H.
Published: February 2012

A range of 2,9‐perfluoroalkyl‐substituted tetraazaperopyrene (TAPP) derivatives (1–5) was synthesised by reacting 4,9‐diamino‐3,10‐perylenequinone diimine (DPDI) with the corresponding carboxylic acid chloride or anhydride in the presence of a base. The reaction of compounds 1–4 with dichloroisocyanuric acid (DIC) in concentrated sulphuric acid resulted in the fourfold substitution of the tetraazaperopyrene core, yielding the 2,9‐bisperfluoroalkyl‐4,7,11,14‐tetrachloro‐1,3,8,10‐tetraazaperopyrenes 6–9, respectively. The optical and electrochemical data demonstrate the drastic influence of the core substitution on the properties. All compounds are highly luminescent (fluorescence quantum yields of up to Φ=0.8). The LUMO energies of the tetrachlorinated TAPP derivatives (determined by cyclic voltammetry and computed by DFT calulations) were found to be below −4 eV. In the course of this work the performance of TAPP derivatives in organic thin‐film transistors (TFTs) was investigated, and their n‐channel characteristics with field‐effect mobilities of up to 0.14 cm2 V−1 s−1 and an on/off current ratio of >106 were confirmed. Long‐term stabilities of 3–4 months under ambient conditions of the devices were established. Complementary inverters and ring oscillators with n‐channel TFTs based on compound 8 and p‐channel TFTs based on dinaphtho‐[2,3‐b:2′,3′‐f]thieno[3,2‐b]thiophene (DNTT) were fabricated on a glass substrate.
Silver(I)‐Catalyzed Tandem 1,3‐Acyloxy Migration/Mannich‐type Addition/Elimination of the Sulfonyl Group of N‐Sulfonylhydrazone‐propargylic Esters to 5,6‐Dihydropyridazin‐4‐one Derivatives
Authors: Zhang Zhen , Shi Min
Published: February 2012

The addition of nucleophiles to CN bonds offers a highly efficient synthetic strategy for accessing nitrogen‐containing molecules.1 Among the well‐developed addition reactions, such as the highly efficient Mannich reaction, various CH bond‐activated compounds including carboxylic acid derivatives, nitroalkanes, and terminal alkynes have been applied as nucleophiles to achieve different classes of amines.2 However, employing new nucleophiles without activated CH bonds, such as internal alkynes and allenic esters are limited when using metal catalysts.3 Herein, we wish to report a new addition of allenic esters to CN bonds initiated by a silver‐catalyzed 1,3‐migration of propargylic esters.
Fully Automated Weighing of Liquid Substances with a Laboratory Robot
Authors: Werner Albert , Blaschke Tim , von Harbou Erik , Hasse Hans
Published: February 2012

Im Labor ist die Einwaage eine Routineoperation, die bei der Durchführung von Messreihen häufig wiederholt wird. Sie erfolgt in der chemischen Industrie noch überwiegend manuell. In dieser Arbeit wird ein Verfahren zur vollautomatischen Einwaage von flüssigen Substanzen in Probengefäße mit einem Laborroboter vorgestellt. Als Anwendungsbeispiel wird die Herstellung von Proben für die Kalibrierung eines Gaschromatographen diskutiert. Die erreichten Genauigkeiten übertreffen die einer sorgfältigen manuellen Einwaage. Mit der vorgestellten Methode lassen sich die meisten im Laborbetrieb gängigen Flüssigkeiten handhaben.