bluuebunny/crossref_metadata_2025 huggingface dataset:
Web 2.0 Open Remote and Virtual Laboratories in Engineering Education
Authors: Salzmann Christophe , Gillet Denis , Esquembre Francisco , Vargas Héctor , Sánchez José , Dormido Sebastián
Published: March 2012

This chapter presents challenges in deploying remote and virtual laboratories as open educational resources with application to engineering education, as well as current trends in using Web 2.0 technologies to enable broader adoption and ease of development. The Spanish initiative to establish a common remote and virtual experimentation infrastructure between various universities is presented as an example of an open laboratory network. This example shows the benefit of sharing complex educational resources. The difficulties that impair the adoption and dissemination of current remote experimentation environments are then analyzed. Smart devices and widgets paradigms are proposed to transform current remote laboratories into new user manageable social entities. The Internet of Things and the Web of People concepts are introduced as a framework for further investigating collaborative, active, and social learning environments. This framework is illustrated in the context of a control course in which smart devices are interfaced through widgets integrated into personal learning environments and shared in a flexible and agile way by the learners.
The Horizons of Experience
Authors: Hines Tony
Published: March 2012

Social researchers consciously and intentionally set out to understand the life-world (Lebenswelt). It is different than knowing the inanimate world of objects. Social study is systematic and as rigorous as natural science but focuses on human experience. The social world we inhabit cradles all human experience. It is the context for meaning, for all being and becoming. Life is a temporal stream of experience that, if we are to understand it, needs to be kept at bay (bracketing it). In doing so, it is as Husserl said at the ‘horizon of experience,’ pre-theoretical. It is only through critical reflection that we understand our lived experience in relation to others, present and past. This chapter reflects on Husserl’s notion of ‘horizon of experience’ to intentionally understand the limits of rational thought on irrational objects. It offers insights through these reflections and possibilities for researching information systems applying phenomenology.
Performance Comparison of AODV and DSDV Routing Protocols of MANET
Authors: Patel Bhaskar N. , Prajapati S.G.
Published: March 2012

A mobile ad hoc network is a collection of mobile nodes communicating without wired network and infrastructure or centralized control. Due to limited transmission range of wireless network, more than single hops may be required to transfer data across the network. In order to reliable communication within the network, a routing protocol is used which are call MANET routing protocol. The major function of such an MANET routing protocol is to establishment short and real route between a pair of nodes so that messages may be delivered in a timely manner. This chapter examines two routing protocols for mobile ad hoc networks– the Destination Sequenced Distance Vector (DSDV), the pro-active routing protocol, and the Ad hoc On- Demand Distance Vector routing (AODV), an re-active routing protocol. The authors compare both protocols based on packet delivery fraction and average delay with changing number of source nodes and pause time.
Analyzing Performance of Ad hoc Routing Protocols under Various Constraints
Authors: Sharma Lalitsen , Gupta Supriya
Published: March 2012

The mobility of nodes in mobile ad hoc networks and absence of any centralized control cause unpredictable changes in the network topologies. This makes routing a challenging task. Several routing protocols for mobile ad-hoc networks have come into existence. The protocols are classified in mainly in three categories: proactive, reactive, and hybrid. In this chapter, a study of one of each of the proactive and reactive protocols (respectively, Destination Sequence Distance Vector routing [DSDV], and Dynamic Source Routing [DSR]) is presented. The performance of above said protocols has been measured under varying mobility environment using NS-2 simulator based upon three quality metrics: average end-to-end delay, throughput, and jitter.
Modelling WSNs Using OMNeT++
Authors: Anggadjaja Erwin , McLoughlin Ian V.
Published: March 2012

Wireless sensor networks (WSNs) have been used to observe and monitor many environments for specific purposes and in many ways over the past few years. A number of operational trade-offs are possible when planning a WSN, influencing coverage, bandwidth, redundancy, lifetime, expandability, and so on. However, for systems in potentially hazardous locations or those experiencing restricted access, system unreliability tends to be the greatest operational concern. In the process of creating reliable WSNs for hazardous locations, it is highly desirable to ensure both an accurate and a reliable system design prior to deployment, and with as little unnecessary trade-off as possible. Especially as sensing systems become larger and more complex, and potential failure modes increase, this becomes more difficult to achieve. In an attempt to answer the question of reliability assurance, the authors investigate WSNs in the context of accurate and fast modelling of such networks. A comprehensive comparison of three modelling tools (ns-2, OPNET, and OMNeT++) is explored in this chapter, concluding that OMNeT++ is worthy of study as an alternative to the other two more established tools. As an illustration of the use of OMNeT++, two modelling schemes are simulated and compared against the theory to determine both bit-level correctness, but also to demonstrate ease of modelling and analysis.
SimuMANET
Authors: Alejos Ana Vazquez , Pérez Paula Gómez , Sanchez Manuel Garcia , Dawood Muhammad
Published: March 2012

Simulation software in MANET research is vital. Such a tool provides a versatile mechanism to understand all the involved aspects of these particular systems, from the radio interface to the last communication layer. In this chapter, the authors present the SimuMANET project, a tool for both simulation and field tests purpose. It allows the deployment of wireless reconfigurable ad-hoc networks and MANETs, assisted by a real-time graphical user interface (GUI) for network traffic monitoring and management of radio electric features of the links established between the active network nodes. Due to a set of functionalities, such as GUI, network topology visualization, traffic and motion pattern configuration, and real-time network status analysis, the simulator introduced here becomes a valid tool for both research and education targets. Two scenarios with different types of motion and traffic are simulated using the SimuMANET tool, and the results are shown and commented to illustrate some capabilities of this software.
An Integration Ontology for Components Composition
Authors: Khemakhem Sofien , Drira Khalil , Jmaiel Mohamed
Published: March 2012

Software components composition can improve the efficiency of knowledge management by composing individual components together for complex distributed application. There are two main areas of research in knowledge representation for component composition: the syntactic based approach and the semantic-based approach. In this paper, the authors propose an integrated ontology-supported software component composition. The authors’ approach provides dual modes to perform component composition. Ontologies are employed to enrich semantics at both components description and composition. The authors demonstrate that their search engine SEC++ fulfills automated component composition, in particular, and knowledge management in general.
Interview
Authors: Adamson Greg , Noble Rick
Published: March 2012

Not-for-profit organisations are significant users of IT services, including Portals, for the use of public outreach and service delivery. While lacking the resources of the commercial sector, many not-for-profit organisations’ needs may be similarly complex if they are relying on a portal for service delivery to a vulnerable client sector, or for the protection of medical records. In this paper, the authors examine the experience of service delivery to two medium-sized not-for-profits in Melbourne, Australia.
Portals, Technology and E-Learning
Authors: Adamson Greg
Published: March 2012

E-learning promises to improve the learning process through the application of technology, including portal technology. Portals can provide the personalisation and interactivity functionality that e-learning requires. However, the long-held promise that technology will improve learning has often failed to deliver. This paper examines the promise of this technology and compares the specific demands of e-learning to the actual capability of portals and the underpinning Internet and World Wide Web. It then identifies four “costs” of using technology for e-learning, and points to existing project management tools that may minimise the effect of these “costs”.
Web Services in Distributed Information Systems
Authors: Zhao Xia , Wang Tao , Liu Enjie , Clapworthy Gordon J.
Published: March 2012

Distributed information systems are growing rapidly in response to the improvement of computer hardware and software and this is matched by the evolution of the technologies involved. This paper focuses mainly on Web Services technology and discusses related technical issues including availability, performance and composition. It also introduces Grid, agents and Semantic Web technologies that can work together with Web Services to serve different business goals.
MaGate
Authors: Huang Ye , Brocco Amos , Courant Michele , Hirsbrunne Beat , Kuonen Pierre
Published: March 2012

This work presents the design and architecture of a decentralized grid scheduler named MaGate, which is developed within the SmartGRID project and focuses on grid scheduler interoperation. The MaGate scheduler is modular structured, and emphasizes the functionality, procedure and policy of delegating local unsuited jobs to appropriate remote MaGates within the same grid system. To avoid an isolated solution, web services and several existing and emerging grid standards are adopted, as well as a series of interfaces to both publish MaGate capabilities and integrate functionalities from external grid components. Meanwhile, a specific swarm intelligence solution is employed as a critical complementary service for MaGate to maintain an optimized peer-to-peer overlay that supports efficient resource discovery. Regarding evaluation, the effectiveness brought by job sharing within a physically connected grid community with the use of the MaGate has been illustrated by means of experiments on communities of different scale, and under various scenarios.
A Study on the Effect of Application and Resource Characteristics on the QoS in Service Provisioning Environments
Authors: Varvarigou Theodora , Tserpes Konstantinos , Kyriazis Dimosthenis , Silvestri Fabrizio , Psimogiannos Nikolaos
Published: March 2012

This article deals with the problem of quality provisioning in business service-oriented environments, examining the resource selection process as an initial matching of the provided to the demanded QoS. It investigates how the application and resource characteristics affect the provided level of QoS, a relationship that intuitively exists but has not yet being mapped. To do so, it focuses on identifying the application and resource parameters that affect the customer-defined QoS parameters. The article realistically centres upon modeling a data mining application and simple PC nodes in order to study how they affect response times. It moves on, by proving the existence of these specific relations and maps them using simple artificial neural networks so as to be able to wrap them in a single mechanism for resource selection based on customer QoS requirements and real time provider QoS capabilities.
Abstractions and Middleware for Petascale Computing and Beyond
Authors: Sbalzarini Ivo F.
Published: March 2012

As high-performance computing moves to the petascale and beyond, a number of algorithmic and software challenges need to be addressed. This paper reviews the main performance-limiting factors in today’s high-performance computing software and outlines a possible new programming paradigm to address them. The proposed paradigm is based on abstract parallel data structures and operations that encapsulate much of the complexity of an application, but still make communication overhead explicit. The authors argue that all numerical simulations can be formulated in terms of the presented abstractions, which thus define an abstract semantic specification language for parallel numerical simulations. Simulations defined in this language can automatically be translated to source code containing the appropriate calls to a middleware that implements the underlying abstractions. Finally, the structure and functionality of such a middleware are outlined while demonstrating its feasibility on the example of the parallel particle-mesh library (PPM).
The Red Storm Architecture and Early Experiences with Multi-Core Processors
Authors: Tomkins James L. , Brightwell Ron , Camp William J. , Dosanjh Sudip , Kelly Suzanne M. , Lin Paul T. , Vaughan Courtenay T. , Levesque John , Tipparaju Vinod
Published: March 2012

The Red Storm architecture, which was conceived by Sandia National Laboratories and implemented by Cray, Inc., has become the basis for most successful line of commercial supercomputers in history. The success of the Red Storm architecture is due largely to the ability to effectively and efficiently solve a wide range of science and engineering problems. The Cray XT series of machines that embody the Red Storm architecture have allowed for unprecedented scaling and performance of parallel applications spanning many areas of scientific computing. This paper describes the fundamental characteristics of the architecture and its implementation that have enabled this success, even through successive generations of hardware and software.
The Sicilian Grid Infrastructure for High Performance Computing
Authors: Iacono-Manno Carmelo Marcello , Fargetta Marco , Barbera Roberto , Falzone Alberto , Andronico Giuseppe , Monforte Salvatore , Muoio Annamaria , Bruno Riccardo , Di Primo Pietro , Orlando Salvatore , Leggio Emanuele , Lombardo Alessandro , Passaro Gianluca , De Francisci-Morales Gianmarco , Blandino Simona
Published: March 2012

The conjugation of High Performance Computing (HPC) and Grid paradigm with applications based on commercial software is one among the major challenges of today e-Infrastructures. Several research communities from either industry or academia need to run high parallel applications based on licensed software over hundreds of CPU cores; a satisfactory fulfillment of such requests is one of the keys for the penetration of this computing paradigm into the industry world and sustainability of Grid infrastructures. This problem has been tackled in the context of the PI2S2 project that created a regional e-Infrastructure in Sicily, the first in Italy over a regional area. Present paper will describe the features added in order to integrate an HPC facility into the PI2S2 Grid infrastructure, the adoption of the InifiniBand low-latency net connection, the gLite middleware extended to support MPI/MPI2 jobs, the newly developed license server and the specific scheduling policy adopted. Moreover, it will show the results of some relevant use cases belonging to Computer Fluid-Dynamics (Fluent, OpenFOAM), Chemistry (GAMESS), Astro-Physics (Flash) and Bio-Informatics (ClustalW)).
A Mathematical Analysis of a Disaster Management Data-Grid Push Service
Authors: Bessis Nik , Brown Antony , Asimakopoulou Eleana
Published: March 2012

Much work is under way within the Grid technology community on issues associated with the development of services fostering the integration and exploitation of multiple autonomous, distributed data sources through a seamless and flexible virtualized interface. These developments involve fluid and dynamic, ad hoc based interactions between dispersed service providers and consumers. However, several obstacles arise in the design and implementation of such services. In this article, the authors examine a notable obstacle, namely how to keep service consumers informed of relevant changes about data committed in multiple and distributed service provider levels, and most importantly, when these changes can affect others’ well-being. To achieve this, the authors use aggregated case scenarios to demonstrate the need for a data-Grid push service in a disaster management situation. In this regard, the article describes in detail the service architecture, as well as its mathematical analysis for keeping interested stakeholders informed automatically about relevant and critical data changes.
Sketch Based Video Annotation and Organization System in Distributed Teaching Environment
Authors: Chen Jia , Ma Cui-xia , Wang Hong-an , Yang Hai-yan , Teng Dong-xing
Published: March 2012

As the use of instructional video is becoming a key component of e-learning, there is an increasing need for a distributed system which supports collaborative video annotation and organization. In this paper, the authors construct a distributed environment on the top of NaradaBrokering to support collaborative operations on video material when users are located in different places. The concept of video annotation is enriched, making it a powerful media to improve the instructional video organizing and viewing. With panorama based and interpolation based methods, all related users can annotate or organize videos simultaneously. With these annotations, a video organization structure is consequently built through linking them with other video clips or annotations. Finally, an informal user study was conducted and result shows that this system improves the efficiency of video organizing and viewing and enhances user’s participating into the design process with good user experience.
Involvement of an NKG2D Ligand H60c in Epidermal Dendritic T Cell-Mediated Wound Repair
Authors: Yoshida Shigeru , Mohamed Rania Hassan , Kajikawa Mizuho , Koizumi Jun , Tanaka Minami , Fugo Kazunori , Otsuka Noriyuki , Maenaka Katsumi , Yagita Hideo , Chiba Hitoshi , Kasahara Masanori
Published: March 2012

Dendritic epidermal T cells (DETCs) found in mouse skin are NKG2D-positive γδ T cells involved in immune surveillance and wound repair. It is assumed that the interaction of an NKG2D receptor on DETCs and an MHC class I-like NKG2D ligand on keratinocytes activates DETCs, which then secrete cytokines promoting wound repair. However, direct evidence that DETC activation through NKG2D signaling promotes wound repair is not available. In the present study, we generated mAbs for an NKG2D ligand H60c previously suggested to be expressed specifically on skin keratinocytes. Local administration of H60c-specific mAb inhibited activation of DETCs and significantly delayed wound repair. Likewise, administration of NKG2D-specific mAb impaired wound repair to a similar extent. The delay in wound closure resulting from the blockade of the NKG2D pathway was comparable to that observed in γδ T cell-deficient mice. These results indicate that H60c/NKG2D interactions play a critical role in wound repair. Reassessment of binding affinities showed that H60c monomers bind to NKG2D with affinity (Kd = 26 ± 3.2 nM) comparable to those of other high-affinity NKG2D ligands. H60c is transcribed not only in skin but also in tissues such as tongue and female reproductive tract known to contain epithelium-resident γδ T cells expressing invariant TCRs, suggesting a more general role for H60c in the maintenance of epithelial integrity.
Caspase-1 Has Both Proinflammatory and Regulatory Properties in Helicobacter Infections, Which Are Differentially Mediated by Its Substrates IL-1β and IL-18
Authors: Hitzler Iris , Sayi Ayca , Kohler Esther , Engler Daniela B. , Koch Katrin N. , Hardt Wolf-Dietrich , Müller Anne
Published: March 2012

The proinflammatory cysteine protease caspase-1 is autocatalytically activated upon cytosolic sensing of a variety of pathogen-associated molecular patterns by Nod-like receptors. Active caspase-1 processes pro–IL-1β and pro–IL-18 to generate the bioactive cytokines and to initiate pathogen-specific immune responses. Little information is available on caspase-1 and inflammasome activation during infection with the gastric bacterial pathogen Helicobacter pylori. In this study, we addressed a possible role for caspase-1 and its cytokine substrates in the spontaneous and vaccine-induced control of Helicobacter infection, as well as the development of gastritis and gastric cancer precursor lesions, using a variety of experimental infection, vaccine-induced protection, and gastric disease models. We show that caspase-1 is activated and IL-1β and IL-18 are processed in vitro and in vivo as a consequence of Helicobacter infection. Caspase-1 activation and IL-1 signaling are absolutely required for the efficient control of Helicobacter infection in vaccinated mice. IL-1R−/− mice fail to develop protective immunity but are protected against Helicobacter-associated gastritis and gastric preneoplasia as a result of their inability to generate Helicobacter-specific Th1 and Th17 responses. In contrast, IL-18 is dispensable for vaccine-induced protective immunity but essential for preventing excessive T cell-driven immunopathology. IL-18−/− animals develop strongly accelerated pathology that is accompanied by unrestricted Th17 responses. In conclusion, we show in this study that the processing and release of a regulatory caspase-1 substrate, IL-18, counteracts the proinflammatory activities of another caspase-1 substrate, IL-1β, thereby balancing control of the infection with the prevention of excessive gastric immunopathology.
In vitro influence of 2-methoxyestradiol-bis-sulphamate on cell numbers, reactive oxygen species production and autophagy induction in a breast adenocarcinoma- and a non- tumorigenic breast epithelial cell line.
Authors: Visagie Michelle H. , Joubert Annie M.
Published: March 2012

This study indicates that 2-methoxyestradiol-bis-sulphamate induces both apoptosis and autophagy and contributes to the unraveling of the action mechanism of 2-methoxyestradiol-bis-sulphamate.
The Safety and Tolerability of Newer Antiepileptic Drugs in Children and Adolescents
Authors: Kayani Saima , Sirsi Deepa
Published: March 2012

Childhood epilepsy continues to be intractable in more than 25% of patients diagnosed with epilepsy. The introduction of new anti-epileptic drugs (AEDs) provides more options for treatment of children with epilepsy. We review the safety and tolerability of seven new AEDs (levetiracetam, lamotrigine, oxcarbazepine, rufinamide, topiramate, vigabatrin and zonisamide) focusing on their side effect profiles and safety in children and adolescents. Many considerations that are specific for children such as the impact of AEDs on the developing brain are not addressed during the development of new AEDs. They are usually approved as adjunctive therapies based upon clinical trials involving adult patients with partial epilepsy. However, 2 of the AEDs reviewed here (rufinamide and vigabatrin) have FDA approval in the U.S. for specific Pediatric epilepsy syndromes, which are discussed below. The Pediatrician or Neurologists decision on the use of a new AED is an evolutionary process largely dependent on the patient characteristics, personal/peer experiences and literature about efficacy and safety profiles of these medications. Evidence based guidelines are limited due to a lack of randomized controlled trials involving pediatric patients for many of these new AEDs.
Exceptionally High Prevalence of Infection of Bithynia siamensis goniomphalos with Opisthorchis viverrini Cercariae in Different Wetlands in Thailand and Lao PDR
Authors: Kiatsopit Nadda , Sithithaworn Paiboon , Saijuntha Weerachai , Boonmars Thidarut , Tesana Smarn , Sithithaworn Jiraporn , Petney Trevor N. , Andrews Ross H.
Published: March 2012

The carcinogenic liver fluke, Opisthorchis viverrini, requires Bithynia snail intermediate hosts in its life cycle. However, the prevalence of O. viverrini in snail intermediate hosts is typically low (< 1%). Here, we examined B. siamensis goniomphalos from 48 localities in Thailand and The Lao People?s Democratic Republic (Lao PDR) and reported high-prevalence levels of O. viverrini. The highest-prevalence levels per locality were 6.93% (mean = 3.04%) in Thailand and 8.37% (mean = 2.01%) in Lao PDR; 4 of 13 localities examined showed prevalence higher than any prevalence previously recorded. The number of cercariae infecting snails and their prevalence were positively correlated with the size of the snails. High prevalence occurred in the Songkram River wetland (Thailand) and the Nam Ngum River wetland (Lao PDR). Our results show that transmission of O. viverrini from humans as well as animal reservoir hosts to snail intermediate hosts is ongoing and potentially increasing in endemic areas across Thailand and Lao PDR.
Determinants of Anopheles Seasonal Distribution Patterns Across a Forest to Periurban Gradient near Iquitos, Peru
Authors: Reinbold-Wasson Drew D. , Sardelis Michael R. , Jones James W. , Watts Douglas M. , Fernandez Roberto , Carbajal Faustino , Pecor James E. , Calampa Carlos , Klein Terry A. , Turell Michael J.
Published: March 2012

As part of a field ecology study of arbovirus and malaria activity in the Amazon Basin, Loreto Department, Peru, we collected mosquitoes landing on humans at a forest site and inside and outside of residences and military barracks at periurban, rural, and village sites. We collected 11 Anopheles spp. from these four sites. An. darlingi, the principal malaria vector in the region, accounted for 98.7% of all Anopheles spp. collected at Puerto Almendra. Peaks in landing activity occurred during the December and April collection periods. However, the percent of sporozoite-positive Anopheles spp. was highest 1–2 months later, when landing activity decreased to approximately 10% of the peak activity periods. At all sites, peak landing activity occurred about 2 hours after sunset. These data provide a better understanding of the taxonomy, population density, and seasonal and habitat distribution of potential malaria vectors within the Amazon Basin region.
Molecular Epidemiologic Characterization of Enterocytozoon bieneusi in HIV-Infected Persons in Benin City, Nigeria
Authors: Akinbo Frederick O. , Okaka Christopher E. , Omoregie Richard , Dearen Theressa , Leon Eucaris Torres , Xiao Lihua
Published: March 2012

Molecular characterization of Enterocytozoon bieneusi has led to better understanding of microsporidiosis transmission in humans. This study aimed to detect and genotype E. bieneusi in human immunodeficiency virus (HIV)-infected persons. Stool specimens were collected from 463 HIV-infected patients and analyzed for E. bieneusi by polymerase chain reaction (PCR) and DNA sequence analysis of the internal transcribed spacer. E. bieneusi was detected in 77 HIV patients. CD4 cell counts < 200 cells/μL was associated with E. bieneusi infection (P = 0.09). E. bieneusi was significantly associated with weight loss (P < 0.0001), diarrhea (P = 0.006), fever (P < 0.0001), not being married (P < 0.0001), and flush type of toilet (P = 0.0007). Six known genotypes of D, A, IV, CAF2, EbpA, and Peru 8 in 31, 22, 14, 2, 1, and 1 patients, respectively, five novel genotypes of E. bieneusi, and one infection with mixed genotypes were observed in this study. Three of the novel genotypes were genetically distant to the genotypes commonly found in humans.
Integrated Implementation of Programs Targeting Neglected Tropical Diseases through Preventive Chemotherapy: Identifying Best Practices to Roll Out Programs at National Scale
Authors: Hanson Christy , Weaver Angela , Zoerhoff Kathryn L. , Kabore Achille , Linehan Mary , Doherty Amy , Engels Dirk , Savioli Lorenzo , Ottesen Eric A.
Published: March 2012

In 2006 the U.S. Agency for International Development (USAID) established the Neglected Tropical Disease (NTD) Control Program to support national governments in developing successful, cost-efficient NTD programs that integrate disease-specific programs into coordinated national initiatives, in accord with the World Health Organization recommendations. A 3-stage “roll-out package” has been developed for effectively integrating and scaling up such programs to full-national scale. Stage-1 lays the groundwork—identifying NTD leadership within the Ministry of Health, conducting a national Situation Analysis, formulating a multiyear Plan of Action, and undertaking a funding gap analysis. Stage-2 focuses on scaling up the integrated NTD program—convening national stakeholder meetings, developing annual work plans, carrying out disease mapping, and establishing monitoring and evaluation activities. Stage-3 aims at ensuring effective management—identifying clear roles and responsibilities for partners, and creating a central coordinating mechanism. Assessment and reassessment of these complex NTD programs that target literally billions of people are essential to establish “best practice” strategies for long-term public health success.
Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols
Authors: Gyawali M. , Arnott W. P. , Zaveri R. A. , Song C. , Moosmüller H. , Liu L. , Mishchenko M. I. , Chen L.-W. A. , Green M. C. , Watson J. G. , Chow J. C.
Published: March 2012

Abstract. We present the laboratory and ambient photoacoustic (PA) measurement of aerosol light absorption coefficients at ultraviolet wavelength (i.e., 355 nm) and compare with measurements at 405, 532, 870, and 1047 nm. Simultaneous measurements of aerosol light scattering coefficients were achieved by the integrating reciprocal nephelometer within the PA's acoustic resonator. Absorption and scattering measurements were carried out for various laboratory-generated aerosols, including salt, incense, and kerosene soot to evaluate the instrument calibration and gain insight on the spectral dependence of aerosol light absorption and scattering. Ambient measurements were obtained in Reno, Nevada, between 18 December 2009 and 18 January 2010. The measurement period included days with and without strong ground level temperature inversions, corresponding to highly polluted (freshly emitted aerosols) and relatively clean (aged aerosols) conditions. Particulate matter (PM) concentrations were measured and analyzed with other tracers of traffic emissions. The temperature inversion episodes caused very high concentration of PM2.5 and PM10 (particulate matter with aerodynamic diameters less than 2.5 μm and 10 μm, respectively) and gaseous pollutants: carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2). The diurnal change of absorption and scattering coefficients during the polluted (inversion) days increased approximately by a factor of two for all wavelengths compared to the clean days. The spectral variation in aerosol absorption coefficients indicated a significant amount of absorbing aerosol from traffic emissions and residential wood burning. The analysis of single scattering albedo (SSA), Ångström exponent of absorption (AEA), and Ångström exponent of scattering (AES) for clean and polluted days provides evidences that the aerosol aging and coating process is suppressed by strong temperature inversion under cloudy conditions. In general, measured UV absorption coefficients were found to be much larger for biomass burning aerosol than for typical ambient aerosols.
Ozone zonal asymmetry and planetary wave characterization during Antarctic spring
Authors: Ialongo I. , Sofieva V. , Kalakoski N. , Tamminen J. , Kyrölä E.
Published: March 2012

Abstract. A large zonal asymmetry of ozone has been observed over Antarctica during winter-spring, when the ozone hole develops. It is caused by a planetary wave-driven displacement of the polar vortex. The total ozone data by OMI (Ozone Monitoring Instrument) and the ozone profiles by MLS (Microwave Limb Sounder) and GOMOS (Global Ozone Monitoring by Occultation of Stars) were analysed to characterize the ozone zonal asymmetry and the wave activity during Antarctic spring. Both total ozone and profile data have shown a persistent zonal asymmetry over the last years, which is usually observed from September to mid-December. The largest amplitudes of planetary waves at 65° S (the perturbations can achieve up to 50% of zonal mean values) is observed in October. The wave activity is dominated by the quasi-stationary wave 1 component, while the wave 2 is mainly an eastward travelling wave. Wave numbers 1 and 2 generally explain more than the 90% of the ozone longitudinal variations. Both GOMOS and MLS ozone profile data show that ozone zonal asymmetry covers the whole stratosphere and extends up to the altitudes of 60–65 km. The wave amplitudes in ozone mixing ratio decay with altitude, with maxima (up to 50%) below 30 km. The characterization of the ozone zonal asymmetry has become important in the climate research. The inclusion of the polar zonal asymmetry in the climate models is essential for an accurate estimation of the future temperature trends. This information might also be important for retrieval algorithms that rely on ozone a priori information.
Interannual variation in the fine-mode MODIS aerosol optical depth and its relationship to the changes in sulfur dioxide emissions in China between 2000 and 2010
Authors: Itahashi S. , Uno I. , Yumimoto K. , Irie H. , Osada K. , Ogata K. , Fukushima H. , Wang Z. , Ohara T.
Published: March 2012

Abstract. Anthropogenic SO2 emissions increased alongside economic development in China at a rate of 12.7% yr−1 from 2000 to 2005. However, under new Chinese government policy, SO2 emissions declined by 3.9% yr−1 between 2005 and 2009. Between 2000 and 2010, we found that the variability in the fine-mode (submicron) aerosol optical depth (AOD) over the oceans adjacent to East Asia increased by 3–8% yr−1 to a peak around 2005–2006 and subsequently decreased by 2–7% yr−1, based on observations by the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Terra satellite and simulations by a chemical transport model. This trend is consistent with ground-based observations of aerosol particles at a mountainous background observation site in central Japan. These fluctuations in SO2 emission intensity and fine-mode AOD are thought to reflect the widespread installation of fuel-gas desulfurization (FGD) devices in power plants in China, because aerosol sulfate is a major determinant of the fine-mode AOD in East Asia. Using a chemical transport model, we confirmed that the contribution of particulate sulfate to the fine-mode AOD is more than 70% of the annual mean and that the abovementioned fluctuation in fine-mode AOD is caused mainly by changes in SO2 emission rather than by other factors such as varying meteorological conditions in East Asia. A strong correlation was also found between satellite-retrieved SO2 vertical column density and bottom-up SO2 emissions, both of which were also consistent with observed fine-mode AOD trends. We propose a simplified approach for evaluating changes in SO2 emissions in China, combining the use of modeled sensitivity coefficients that describe the variation of fine-mode AOD with changes in SO2 emissions and satellite retrieval. Satellite measurements of fine-mode AOD above the Sea of Japan marked a 4.1% yr−1 decline between 2007 and 2010, which corresponded to the 9% yr−1 decline in SO2 emissions from China during the same period.
Fast simulators for satellite cloud optical centroid pressure retrievals; evaluation of OMI cloud retrievals
Authors: Joiner J. , Vasilkov A. P. , Gupta P. , Bhartia P. K. , Veefkind P. , Sneep M. , de Haan J. , Polonsky I. , Spurr R.
Published: March 2012

Abstract. The cloud Optical Centroid Pressure (OCP) is a satellite-derived parameter that is commonly used in trace-gas retrievals to account for the effects of clouds on near-infrared through ultraviolet radiance measurements. Fast simulators are desirable to further expand the use of cloud OCP retrievals into the operational and climate communities for applications such as data assimilation and evaluation of cloud vertical structure in general circulation models. In this paper, we develop and validate fast simulators that provide estimates of the cloud OCP given a vertical profile of optical extinction. We use a pressure-weighting scheme where the weights depend upon optical parameters of clouds and/or aerosols. A cloud weighting function is easily extracted using this formulation. We then use fast simulators to compare two different satellite cloud OCP retrievals, from the Ozone Monitoring Instrument (OMI), with estimates based on collocated cloud extinction profiles from a combination of CloudSat radar and MODIS visible radiance data. These comparisons are made over a wide range of conditions to provide a comprehensive validation of the OMI cloud OCP retrievals. We find generally good agreement between OMI cloud OCPs and those predicted by CloudSat. However, the OMI cloud OCPs from the two independent algorithms agree better with each other than either does with the estimates from CloudSat/MODIS. Differences between OMI cloud OCPs and those based on CloudSat/MODIS may result from undetected snow/ice at the surface, cloud 3-D effects, cases of low clouds obscurred by ground-clutter in CloudSat observations and by opaque high clouds in CALIPSO lidar observations, and the fact that CloudSat/CALIPSO only observes a relatively small fraction of an OMI field-of-view.
Global characteristics of the lunar tidal modulation of the equatorial electrojet derived from CHAMP observations
Authors: Lühr H. , Siddiqui T. A. , Maus S.
Published: March 2012

Abstract. It has been known since many decades that lunar tide has an influence on the strength of the equatorial electrojet (EEJ). There has, however, never been a comprehensive study of the tidal effect on a global scale. Based on the continuous magnetic field measurements by the CHAMP satellite over 10 years it is possible to investigate the various aspects of lunar effects on the EEJ. The EEJ intensity is enhanced around times when the moon is overhead or at the antipode. This effect is particularly strong around noon, shortly after new and full moon. The lunar tide manifests itself as a semi-diurnal wave that precesses through all local times within one lunar month. The largest tidal amplitudes are observed around December solstice and smallest around June solstice. The tidal wave crest lags behind the moon phase. During December this amounts to about 4 days while it is around 2 days during other times of the year. We have not found significant longitudinal variations of the lunar influence on the EEJ. When comparing the average EEJ amplitude at high solar activity with that during periods of solar minimum conditions a solar cycle dependence can be found, but the ratio between tidal amplitude and EEJ intensity stays the same. Actually, tidal signatures standout clearer during times of low solar activity. We suggest that the tidal variations are caused by a current system added to the EEJ rather than by modulating the EEJ. Gravitational forcing of the lower atmosphere by the moon and the sun is assumed to be the driver of an upward propagating tidal wave. The larger tidal amplitudes around December solstice can be related to stratospheric warming events which seem to improve the conditions for upward propagation. The results described here have to large extent been presented as a Julius-Bartels Medal Lecture during the General Assembly 2011 of the European Geosciences Union.
Characterization of deep aquifer dynamics using principal component analysis of sequential multilevel data
Authors: Kurtzman D. , Netzer L. , Weisbrod N. , Nasser A. , Graber E. R. , Ronen D.
Published: March 2012

Abstract. Two sequential multilevel profiles were obtained in an observation well opened to a 130-m thick, unconfined, contaminated aquifer in Tel Aviv, Israel. While the general profile characteristics of major ions, trace elements, and volatile organic compounds were maintained in the two sampling campaigns conducted 295 days apart, the vertical locations of high concentration gradients were shifted between the two profiles. Principal component analysis (PCA) of the chemical variables resulted in a first principal component which was responsible for ∼60% of the variability, and was highly correlated with depth. PCA revealed three distinct depth-dependent water bodies in both multilevel profiles, which were found to have shifted vertically between the sampling events. This shift cut across a clayey bed which separated the top and intermediate water bodies in the first profile, and was located entirely within the intermediate water body in the second profile. Continuous electrical conductivity monitoring in a packed-off section of the observation well revealed an event in which a distinct water body flowed through the monitored section (v ∼ 150 m yr−1). It was concluded that the observed changes in the profiles result from dominantly lateral flow of water bodies in the aquifer rather than vertical flow. The significance of this study is twofold: (a) it demonstrates the utility of sequential multilevel observations from deep wells and the efficacy of PCA for evaluating the data; (b) the fact that distinct water bodies of 10 to 100 m vertical and horizontal dimensions flow under contaminated sites, which has implications for monitoring and remediation.
On teaching styles of water educators and the impact of didactic training
Authors: Pathirana A. , Koster J. H. , de Jong E. , Uhlenbrook S.
Published: March 2012

Abstract. Solving today's complex hydrological problems requires originality, creative thinking and trans-disciplinary approaches. Hydrological education that was traditionally teacher centred, where the students look up to the teacher for expertise and information, should change to better prepare hydrologists to develop new knowledge and apply it in new contexts. An important first step towards this goal is to change the concept of education in the educators' minds. The results of an investigation to find out whether didactic training influences the beliefs of hydrology educators about their teaching styles is presented. Faculty of UNESCO-IHE has been offered a didactic certification program named University Teaching Qualification (UTQ). The hypothesis that UTQ training will significantly alter the teaching style of faculty at UNESCO-IHE from expert/formal authority traits towards facilitator/delegator traits was tested. A first survey was conducted among the entire teaching staff (total 101, response rate 58%). The results indicated that there are significantly higher traits of facilitator and delegator teaching styles among UTQ graduates compared to faculty who were not significantly trained in didactics. The second survey which was conducted among UTQ graduates (total 20, response rate 70%), enquiring after their teaching styles before and after UTQ, corroborated these findings.
Assessing the potential hydrological impact of the Gibe III Dam on Lake Turkana water level using multi-source satellite data
Authors: Velpuri N. M. , Senay G. B.
Published: March 2012

Abstract. Lake Turkana, the largest desert lake in the world, is fed by ungauged or poorly gauged river systems. To meet the demand of electricity in the East African region, Ethiopia is currently building the Gibe III hydroelectric dam on the Omo River, which supplies more than 80% of the inflows to Lake Turkana. On completion, the Gibe III dam will be the tallest dam in Africa with a height of 241 m. However, the nature of interactions and potential impacts of regulated inflows to Lake Turkana are not well understood due to its remote location and unavailability of reliable in-situ datasets. In this study, we used 12 years (1998–2009) of existing multi-source satellite and model-assimilated global weather data. We use calibrated multi-source satellite data-driven water balance model for Lake Turkana that takes into account model routed runoff, lake/reservoir evapotranspiration, direct rain on lakes/reservoirs and releases from the dam to compute lake water levels. The model evaluates the impact of Gibe III dam using three different approaches such as (a historical approach, a knowledge-based approach, and a nonparametric bootstrap resampling approach) to generate rainfall-runoff scenarios. All the approaches provided comparable and consistent results. Model results indicated that the hydrological impact of the dam on Lake Turkana would vary with the magnitude and distribution of rainfall post-dam commencement. On average, the reservoir would take up to 8–10 months, after commencement, to reach a minimum operation level of 201 m depth of water. During the dam filling period, the lake level would drop up to 2 m (95% confidence) compared to the lake level modelled without the dam. The lake level variability caused by regulated inflows after the dam commissioning were found to be within the natural variability of the lake of 4.8 m. Moreover, modelling results indicated that the hydrological impact of the Gibe III dam would depend on the initial lake level at the time of dam commencement. Areas along the Lake Turkana shoreline that are vulnerable to fluctuations in lake levels were also identified. This study demonstrates the effectiveness of using existing multi-source satellite data in a basic modeling framework to assess the potential hydrological impact of an upstream dam on a terminal downstream lake. The results obtained from this study could also be used to evaluate alternate dam-filling scenarios and assess the potential impact of the dam on Lake Turkana under different operational strategies.
Current Strategies to Enhance Recovery following Radical Cystectomy: Single Centre Initial Experience
Authors: Vasdev Nikhil , Pillai Praveen L. , Snowdon Christopher P. , Thorpe Andrew C.
Published: March 2012

A radical cystectomy (RC) with pelvic lymph node dissection is the gold standard treatment for muscle-invasive bladder carcinoma. The morbidity associated with RC is clearly lower than that in the previous decades; it still continues to remain higher than 30% in the early postoperative period associated with and remains the most effective method for local control. We present current strategies being developed to further enhance recovery in patients undergoing RC and stratifying these into pre, intra, and post operative. We present our current strategies to enhance revcovery in patients undergoing RC which includes a combination of a through preoperative assessment with cardiopulmonary exercise (CPX), preoperative carbohydrate loading drinks, and intraoperative fluid monitoring with the trans-oesophageal Doppler probe (TODP) that may enhance recovery following radical cystectomy. We conclude that using these strategies may not only help in reducing peri/post operative morbidity and the duration of inpatient stay but may also help in enhancing the patient’s long-term recovery.
Behcet's Disease: New Concepts in Cardiovascular Involvements and Future Direction for Treatment
Authors: Owlia M. B. , Mehrpoor G.
Published: March 2012

Behcet’s disease (BD) is the only systemic vasculitis involving both arteries and vein in any sizes. It frequently encounters in rheumatology clinics. It has some major morbidities and even fatal outcomes in some cases. The aim of this paper is to analyze the main concepts on pathophysiology and treatment options in BD, focusing on cardiovascular aspects, thrombosis, and potential future treatment.