bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collaborative Work in Online Learning Environments
Authors: Yukselturk Erman , Cagiltay Kursat 
Published: May 2011

The focus of this study is on issues that impact the success of collaborative working online learning groups. The issues of how such groups work collaboratively, how to facilitate them, and what makes work in such groups satisfactoryand successful were explored. The data were collected by semi-structured interviews from the participants in anonline, project-based course. Hackman and Morris (1975)’s model was used as an analysis framework while interpreting the data. According to the results, it is found that group homogeneity plays a major role on successful group work. The second major finding is the importance of face-to-face communication among online teams. The findings of this study are especially important for those people who are planning to organize activities which involve collaborative learning groups.
Did We Become a Community? Multiple Methods for Identifying Community and Its Constituent Elements in Formal Online Learning Environments
Authors: Schwier Richard A. , Daniel Ben 
Published: May 2011

To understand the nature of formal virtual learningcommunities in higher education, we are employing a variety of user-centred evaluation approaches to examinemethods for determining whether a community exists, andif it does, to isolate and understand interactions among itsconstituent elements, and ultimately to build a model offormal virtual learning communities. This chapter presents the methods we are employing to answer these seemingly simple questions, including user perceptions of community(Sense of Community Index, Classroom Community Scale), interaction analysis (density, reciprocity,) content analysis (transcript analysis, interviews, focus groups), paired-comparison analysis (Thurstone scaling) and communitymodeling techniques (Bayesian Belief Network analysis).
E-Learning 2.0
Authors: Chaka Chaka 
Published: May 2011

This chapter contends that both Web 2.0 and the SemanticWeb (the SW) serve as critical enablers for e-learning 2.0. It also maintains that the SW has the potential to take e-learning 2.0 to new frontiers of advancement. Most significantly, the chapter argues that Web 2.0 and the SW provide an ideal platform for harnessing collectiveintelligence, collective knowledge, the power of thegroundswell, the network effect, and the collective powerof simulation for higher education institutions (HEIs) in thearea of elearning 2.0. Against this backdrop, the chapter provides, first, a short overview of e-learning 2.0, Web 2.0and the SW. Second, it characterises the way in which Web2.0 social software technologies (e.g., blogs, wikis, social networks and virtual worlds) can be deployed in HEIs for delivering e-learning 2.0 for educational purposes. In addition, it outlines the manner in which the SW (in theform of semantic blogs, semantic wikis, semantic social networks and semantic virtual worlds) can enhance each ofthese Web 2.0 technologies for deploying e-learning 2.0 in HEIs.
Angola LNG Nearshore Pipeline Bundle Pull Construction and Installation
Authors: Warren Lee Michael , Pelloux Dominique , Semel Francois , Wallerand Regis 
Published: May 2011

Abstract
This paper describes the construction and installation of a 932m long bundled submarine pipeline system to make the connection between the onshore pipeline and the nearshore pipeline sections of the Angola LNG project. The bundle consisted of three separate heavy-walled, concrete coated pipes, 18??, 22??, and 24?? connected together which were pulled from on onshore stringing right-of-way, down an excavated slope and through a 12m wide excavated cofferdam and into the ocean. The pulling was done by a 300mT linear winch secured to a cargo barge located 1.2km offshore. All three pipelines are part of the Sonangol offshore pipeline network and will initially deliver feed gas to the Angola LNG plant located in Soyo, Angola. The pipeline network will be operated by Sociedade De Operações & Manutenção de Gasodutos S.A. (SOMG).
The construction of the bundle is discussed as well as the installation engineering challenges of pulling the bundle.

Introduction
There are numerous options when it comes to installing pipelines at a landfall site. These options were made available during the FEED study, but careful consideration had to be given to the engineering and financial feasibility of these options. One of the main considerations for the Angola LNG project is how the tie-in would be performed offshore in very shallow water with a pipelay vessel inside a dredged channel. As such, it was decided that the pipelines would be built onshore on a right-of-way allocated by the company, and the pipelines would be pulled into the water using a 300mT linear winch secured to a cargo barge moored offshore.
Once a bundled pipeline philosophy was decided upon many installation challenges arose to install the heavy concrete coated pipelines. There was a large amount of excavation and earth work to be completed for the landfall, a cofferdam had to be built and excavated, and a dredged channel had to be constructed for the pipelines to be laid in and later backfilled. An enormous challenge was to build the pipeline strings long enough on the allocated right-of-way to allow a pipelay vessel to safely come as close as possible within the dredged trench to recover each individual line and be laid to its respective block offshore. Environmental conditions had to be mitigated as there were extreme amounts of erosion and sedimentation in the area as well as large bottom currents which threatened the on-bottom stability of the bundle. Finally, as the three pipelines belonged to three separate operators, there was a client requirement to have 3m separation between the pipelines, centerline to centerline, which made the bundle nearly 7m wide. To maintain the 3m separation, clamped spacers were positioned every 300m along the bundle.
Imaging of Backscattered Ionizing Radiation - A Key Enabler for through Mud Borehole Imaging
Authors: Teague Philip Neil 
Published: May 2011

Abstract
Current technology offers the operators of well-intervention equipment little opportunity to receive accurate and real-time visual feedback from the borehole when the fluid contents are opaque. As a result, the majority of operations are performed 'blind' leading to extensive use of time and increased risk of material damages. In extreme cases, and in the pursuit of a clear image the well's contents must be displaced and replaced with fluids that offer better visibility for video cameras at the possible expense of well integrity.
Previous work within the field of borehole imaging has focused upon optical cameras, ultrasound and millimeter-wave technologies. Ionizing radiation is not perturbed by the optical opacity of the well contents or refracted and distorted by flowing fluids. The paper provides detailed results of data gathered from laboratory and field testing. In addition, the paper illustrates images of objects located in a drilling-fluid-filled well. The information provided offers an overview of a new technology and method, which solves the issues surrounding in-hole imaging of infrastructure, well-integrity inspection, and lost or stuck items without the need to displace the well contents.
An overview of the development efforts involving the creation of a borehole tool which aims to solve the issue of through mud imaging, or imaging in a producing well without the need to displace the current contents to an optically clear fluid. The paper gives an overview of the steps necessary to mitigate the risk of such a development project, and an overview of the most important lessons learned. Imaging of backscattered ionizing radiation can find applications within well integrity inspection, perforation inspection, well auditing and the location and orientation of lost or stuck items within the borehole.

Introduction
One of the major financial concerns voiced by the drilling industry is lost time due to unplanned events such as items lost or stuck downhole in addition to well integrity issues. A number of companies have launched a series of major initiatives that have seen the number of such incidents fall substantially; however, the problem has not been completely possible to eradicate (Fowler, 1996).
Drill string or a downhole tool stuck in a well can prove to be expensive, not only due to possible material damages but due to lost time. Not only are the increasingly sophisticated array of downhole tools and the time lost using them costly, but also the inability to retrieve them could realistically result in the loss of a well.
A common precursor to a fishing expedition is lowering a lead block into the hole and taking an impression of the end of the fish to give the engineers some idea about the best fishing tool to select in order to remove the snapped drill strings or other items. The problem is, however, there is still a distinct challenge in interpreting these impressions and unless the identity is obvious, the impression can be discarded (Walker, 1984).
Inflammatory Cytokines IL-32 and IL-17 Have Common Signaling Intermediates despite Differential Dependence on TNF-Receptor 1
Authors: Turner-Brannen Emily , Choi Ka-Yee Grace , Arsenault Ryan , El-Gabalawy Hani , Napper Scott , Mookherjee Neeloffer 
Published: May 2011

AbstractCytokines IL-32 and IL-17 are emerging as critical players in the pathophysiology of immune-mediated chronic inflammatory diseases. It has been speculated that the molecular mechanisms governing IL-32– and IL-17–mediated cellular responses are differentially dependent on the TNF pathway. In this study, kinome analysis demonstrated that following stimulation with cytokine IL-32, but not IL-17, there was increased phosphorylation of a peptide target corresponding to TNF-R1. Consistent with this observation, blocking TNF-R1 resulted in a suppression of IL-32–induced downstream responses, indicating that IL-32–mediated activity may be dependent on TNF-R1. In contrast, blocking TNF-R1 did not affect IL-17–induced downstream responses. Kinome analysis also implicated p300 (transcriptional coactivator) and death-associated protein kinase-1 (DAPK-1) as signaling intermediates for both IL-32 and IL-17. Phosphorylation of p300 and DAPK-1 upon stimulation with either IL-32 or IL-17 was confirmed by immunoblots. The presence of common targets was supported by results demonstrating similar downstream responses induced in the presence of IL-32 and IL-17, such as transcriptional responses and the direct activation of NF-κB. Furthermore, knockdown of p300 and DAPK-1 altered downstream responses induced by IL-32 and IL-17, and impacted certain cellular responses induced by TNF-α and IL-1β. We hypothesize that p300 and DAPK-1 represent nodes where the inflammatory networks of IL-32 and IL-17 overlap, and that these proteins would affect both TNF-R1–dependent and –independent pathways. Therefore, p300 and DAPK-1 are viable potential therapeutic targets for chronic inflammatory diseases.
Tight Control of STAT5 Activity Determines Human CD34-Derived Interstitial Dendritic Cell and Langerhans Cell Development
Authors: van de Laar Lianne , van den Bosch Aniek , Wierenga Albertus T. J. , Janssen Harry L. A. , Coffer Paul J. , Woltman Andrea M. 
Published: May 2011

Abstract
Despite the crucial function of dendritic cells (DC) in immunity, the molecular mechanisms regulating human DC development remain poorly defined. STAT5 regulates various hematopoietic lineages and is activated by GM-CSF, a critical cytokine in DC development. In this study, we investigated the role of STAT5 during differentiation of human CD34+ hematopoietic progenitors into precursor DC (pre-DC) and their subsequent differentiation toward interstitial DC and Langerhans cells. Inhibiting STAT5 activity by dominant-negative STAT5 promoted Langerhans cell commitment of hematopoietic progenitors but resulted in loss of pre-interstitial DC development, showing subset-specific regulation. Increasing the low endogenous STAT5 activity by ectopic STAT5 activation downregulated expression of the critical DC transcription factor PU.1 and abrogated commitment to either DC lineage. In contrast, high STAT5 activity was beneficial in already committed pre-DC: terminal DC differentiation was associated with increased endogenous STAT5 phosphorylation levels, JAK2–STAT5 inhibition reduced terminal DC differentiation, and conditional STAT5 activation in pre-DC improved development of BDCA-1+, DC-SIGN+, and Langerin+ DC with normal maturation and T cell stimulation. These data show that STAT5 critically regulates human DC development, with specific requirements for the level of STAT5 activation at distinct differentiation stages. By regulating STAT5 activity, cytokines present at specific locations and under different pathophysiological conditions can determine the fate of DC precursors.
IL-10 Prevents Apoptosis of Brain Endothelium during Bacteremia
Authors: Londoño Diana , Carvajal Jenny , Strle Klemen , Kim Kwang S. , Cadavid Diego 
Published: May 2011

AbstractIL-10–deficient mice infected with the relapsing fever bacterium Borrelia turicatae rapidly succumb to a brain hemorrhage if they are unable to clear peak bacteremia. In this study, we investigated the protective role of IL-10 during relapsing-remitting bacteremia and explored the molecular events involved in the protection of brain endothelium by IL-10. Brain endothelial injury was measured with cytotoxicity and diverse apoptotic assays, whereas the signaling pathway analysis was done by quantitative PCR array. The results showed that severe endothelial cell injury leading to hemorrhage in the brain and other organs occurred in IL-10–deficient mice during relapsing-remitting infection. Human brain microvascular endothelial cells (HBMEC) produced abundant proinflammatory mediators upon exposure to whole bacteria or purified bacterial lipoprotein but did not produce any detectable IL-10. Whole bacteria and purified outer membrane lipoprotein rapidly killed HBMEC by apoptosis in a time- and concentration-dependent manner. Exogenous IL-10 protected HBMEC from apoptosis. HBMEC apoptosis during exposure to a low number of bacteria was associated with downregulation of TNF and TNFAIP3 and upregulation of BAX. In contrast, HBMEC apoptosis during exposure to high concentrations of purified outer membrane lipoprotein was associated with marked upregulation of FAS, FAS ligand, and the adaptor molecules RIPK1 and CFLAR. Exogenous IL-10 reversed all the apoptotic signaling changes induced by whole bacteria or its purified lipoprotein. The results indicate that prominent brain endothelial cell apoptosis occurs during relapsing-remitting bacteremia in the absence of IL-10 and point to a prominent role for bacterial lipoprotein-mediated activation of FAS and caspase-3 in this process.
Tuning of Charge Densities in Graphene by Molecule Doping
Authors: Medina Henry , Lin Yung‐Chang , Obergfell Dirk , Chiu Po‐Wen 
Published: May 2011

AbstractThe tuning of carrier concentrations in graphene is at the heart of graphene‐based nanoelectronic and optoelectronic applications. Molecular doping, that is, taking charges from the adsorbed molecules, shows promise as a means by which to change carrier density in graphene while retaining relative high mobility. However, poor control over doping concentrations is a major obstacle to practical applications. Here, we show that lattice disorders induced by plasma exposure can be used as anchor groups. These groups serve as centers of molecule adsorption and facilitate orbital overlap between graphene and adsorbates (melamine), thus allowing for selective and tunable doping. The carrier concentration revealed by Raman shift can be progressively adjusted up to 1.4 × 1013 cm−2, depending on the coverage of melamine molecules and doping temperature. The electronic band structures of the graphene–melamine complex were calculated using density functional theory for adsorption over ideal graphene and over non‐ideal graphene with Stone–Wales (5–7‐7–5) defects. It is shown that charge transfer for adsorption on ideal graphene is negligible, while adsorption on graphene with Stone–Wales defects results in weak hole doping, which is consistent with the progressive increase of carrier density with increasing melamine coverage.
A guaranteed monotonically convergent iterative learning control
Authors: Madady Ali , Reza‐Alikhani Hamid‐Reza 
Published: May 2011

AbstractThis paper presents a new iterative learning control (ILC) scheme for linear discrete time systems. In this scheme, the input of the controlled system is modified by applying a semi‐sliding window algorithm, with a maximum length of n + 1, on the tracking errors obtained from the previous iteration (n is the order of the controlled system). The convergence of the presented ILC is analyzed. It is shown that, if its learning gains are chosen proportional to the denominator coefficients of the system transfer function, then its monotonic convergence condition is independent of the time duration of the iterations and depends only on the numerator coefficients of the system transfer function. The application of the presented ILC to control second‐order systems is described in detail. Numerical examples are added to illustrate the results.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Adsorption of Cationic Dyes from Aqueous Solution by Termite Feces, a Non‐Conventional Adsorbent
Authors: Debrassi Aline , Rodrigues Clóvis Antonio 
Published: May 2011

AbstractThe adsorption of three cationic dyes (rhodamine B, RB; crystal violet, CV; and malachite green, MG) onto termite feces, a low‐cost adsorbent, was investigated. The adsorbent was characterized by IR spectroscopy, point of zero charge measurement, and the Boehm titration method. The adsorption follows the pseudo‐second‐order kinetic model and the Langmuir–Freundlich isotherm with maximum adsorption capacities of 95.53 mg g−1 (RB), 75.71 mg g−1 (CV), and 44.78 mg g−1 (MG). The study of thermodynamics showed that the adsorption is a spontaneous and endothermic process. This works suggest that termite feces can be used as a new low‐cost adsorbent for cationic dye removal.
A taxonomy and survey on autonomic management of applications in grid computing environments
Authors: Rahman Mustafizur , Ranjan Rajiv , Buyya Rajkumar , Benatallah Boualem 
Published: May 2011

AbstractIn Grid computing environments, the availability, performance, and state of resources, applications, services, and data undergo continuous changes during the life cycle of an application. Uncertainty is a fact in Grid environments, which is triggered by multiple factors, including: (1) failures, (2) dynamism, (3) incomplete global knowledge, and (4) heterogeneity. Unfortunately, the existing Grid management methods, tools, and application composition techniques are inadequate to handle these resource, application and environment behaviors. The aforementioned characteristics impose serious requirements on the Grid programming and runtime systems if they wish to deliver efficient performance to scientific and commercial applications. To overcome the above challenges, the Grid programming and runtime systems must become autonomic or self‐managing in accordance with the high‐level behavior specified by system administrators. Autonomic systems are inspired by biological systems that deal with similar challenges of complexity, dynamism, heterogeneity, and uncertainty. To this end, we propose a comprehensive taxonomy that characterizes and classifies different software components and high‐level methods that are required for autonomic management of applications in Grids. We also survey several representative Grid computing systems that have been developed by various leading research groups in the academia and industry. The taxonomy not only highlights the similarities and differences of state‐of‐the‐art technologies utilized in autonomic application management from the perspective of Grid computing, but also identifies the areas that require further research initiatives. We believe that this taxonomy and its mapping to relevant systems would be highly useful for academic‐ and industry‐based researchers, who are engaged in the design of Autonomic Grid and more recently, Cloud computing systems. Copyright © 2011 John Wiley & Sons, Ltd.
A novel, low‐complexity, high‐speed envelope detector and its applications
Authors: Ngo Trong‐Hieu , Lee Tae‐Woo , Park Hyo‐Hoon 
Published: May 2011

SUMMARYA compact and effective transmission envelope detector (TED), which can detect whether the absolute amplitude of an input differential signal is larger than a threshold or not, is proposed. The TED has been demonstrated to be applicable for received signal strength indicator circuit in wireless communication receivers or power management systems, and mode‐control circuit in bidirectional optical transceivers. Implemented in a 0.18 µm CMOS technology, the TED has a response time of 210 ps at 5 Gbps, occupies an active area of 0.05 mm2, and consumes 1 mA from 1.8 V supply. Copyright © 2011 John Wiley & Sons, Ltd.
MOCVD Fabrication of Magnesium Fluoride Films: Effects of Deposition Parameters on Structure and Morphology
Authors: Fragalà Maria E. , Toro Roberta G. , Privitera Salvatore , Malandrino Graziella 
Published: May 2011

AbstractMagnesium fluoride (MgF2) films are fabricated via low pressure metal‐organic (MO)CVD on glass or quartz substrates from the novel single‐source precursor Mg(hfa)2 · 2H2O · 2diglyme. The nature and quality of films are scrutinized depending on relevant operational parameters, namely the deposition temperature, the precursor vaporization rate, and finally the flow of the oxygen reacting gas. Grazing incidence X‐ray diffraction (GIXRD) data point to the formation of crystalline MgF2 films. Scanning electron microscope (SEM) images indicate very homogeneous surfaces with grain dimensions dependent upon operational conditions, while energy dispersive X‐ray (EDX) analyses point to the absence of any C or O contaminants. Smooth and homogeneous surfaces can be obtained upon deposition under high oxygen flow. The MgF2 film deposited on glass at 400 °C under optimized conditions shows a ∼80% transmittance in the range 300 − 800 nm. The high crystalline and optical quality of the MgF2 films, deposited using mild deposition temperatures (< 450 °C) still confirms MOCVD as a versatile and competitive deposition technique.
Pyrrolopyrrole Cyanines: Effect of Substituents on Optical Properties
Authors: Fischer Georg M. , Klein Matthias K. , Daltrozzo Ewald , Zumbusch Andreas 
Published: May 2011

AbstractTo tune their optical properties, a large variety of pyrrolopyrrole cyanines (PPCys) were synthesized with substitutedheteroaromatics such as quinoline, benzothiazole, and oxazole derivatives as terminal groups. Thus, a broad range of stable, highly fluorescing near‐infrared (NIR) dyes with high absorptivities between 690 to 845 nm is accessible. The large number of newly synthesized compounds allows a detailed discussion of the correlation between molecular structure and the optical properties of the first electronic transition.
The living‐tissue microscope: the importance of studying stem cells in their natural, undisturbed microenvironment
Authors: Spradling Allan C 
Published: May 2011

AbstractAdvances in stem cell research highlight the importance of analysing multicellular interactions in vivo before modelling them in cell culture systems. Gain‐of‐function assays such as transplantation are useful, but are not equivalent to studying cells in their natural, undisturbed microenvironment. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.