bluuebunny/crossref_metadata_2025 huggingface dataset:
Sample Size Effects on the Application of Mercury Injection Capillary Pressure for Determining the Storage Capacity of Tight Gas and Oil Shales
Authors: Comisky J. T. , Santiago M. , McCollom B. , Buddhala A. , Newsham K. E.
Published: December 2011

We measured Mercury Injection Capillary Pressure (MICP) profiles on tight shale samples with a variety of sample sizes. The goal was to optimize the rock preparation and data reduction workflow for determining the storage properties of the rock, particularly porosity, from MICP measurements. The rock material was taken from a whole core in the Cretaceous Eagle Ford Formation in the form of a puck or disc. A horizontal 1 inch core plug was cut from this disc and the remaining material was subsequently crushed and sieved through various mesh sizes. MICP profiles up to 60,000 psia were then measured on the 1 inch plug and all of the various crushed and sieved rock particle sizes. In parallel we subsampled the plug material to measure bulk volume, grain volume, and porosity using a crushed rock helium pycnometry method. These additional measurements provided a comparison set of standard petrophysical properties from which we could compare the MICP results.

In general our MICP profiles show a very strong dependence on sample size due to two reasons: pore accessibility and conformance. We verify the conformance correction approach of Bailey (2009) which specifically accounts for the pore volume compression of the sample before mercury has been injected into the largest set of interconnected pore throats. This new method is preferred over the traditional method of conformance correction when compared to crushed rock helium porosity since the latter is performed at unstressed conditions. Our results using Bailey’s (2009) method reveals that the -20+35 sample size is optimal for determining porosity in the Eagle Ford, and potentially other tight oil and gas shales.

We use mercury injection for determining the various storage properties of tight shale because helium porosimetry is not always possible on fine cuttings samples. There are many instances when limited cuttings may be the only source of rock information available before a whole core is taken. Cuttings profiles also provide a key insight over long formation intervals that may not be available from whole core. Cuttings and core profiles for use in calibrating well logs have proven to be a requirement in these ultra-low perm systems.
Early Results from a Carbonate Steamflood Pilot in 1st Eocene Reservoir, Wafra Field, PZ
Authors: Brown Joel , Deemer Art , Al-Dhafeeri Fahad , Lekia Solomon , Hoadley Steve , Al-Mutairi Ghanim , Al-Yami Falah , Barge David
Published: December 2011

A large scale steamflood pilot test has been underway since 2008 in the first Eocene reservoir in the Wafra Field in the Partitioned Zone (PZ) between Saudi Arabia and Kuwait. The first Eocene is a carbonate reservoir and it is the shallowest reservoir in the Wafra Field with an average depth of 1,000 feet The primary objective of the pilot is to reduce technical and economic risk/uncertainty to determine whether full field steamflood development is feasible.

The pilot consists of sixteen 2.5 acre inverted 5 spot patterns with associated steamflood and production facilities. The injection interval is the 1st Eocene "C" interval at a depth of 1300 ft. This is the first multi-pattern steamflood of a carbonate reservoir in the Middle East.

This presentation will share the early results from the implementation of the pilot project. The production response to carbonate steamflooding will be shown along with examples of individual well production behavior. Early insights into carbonate steamflood response, variability of production response by pattern and the identification of operating issues associated with carbonate steamflooding will be shared.

The success of the pilot test project has huge implications to not only the PZ, but to the entire Middle East region due to the vast amount of oil contained in reservoirs that would be considered targets for the steamflood process.

Conclusions and lessons learned that can be drawn from carbonate steamflooding results to date in the pilot will also be shared in the presentation
Nuclear Spectrometry Logs on High-Viscosity Oil Fields
Authors: Chernoletskiy K. V. , Kartamyshev S. V. , Zhuravlev T. B. , Ursegov S. O.
Published: December 2011

The paper is devoted to the problem and results of applying up-to-date nuclear spectrometry logs including C/O log for high-viscosity oil pool studies. Information about applied measurement technologies, tools, new comprehensive interpretation techniques has been given. Practical examples of the effectiveness of the nuclear logs in formation water salinity evaluation and localization of water flooded zones in oil recovery by thermal methods have been shown. Techniques for reliable forecasting of the characteristics of the inflows obtained in reservoir tests have been developed.
Design Approach and Early Field Performance for a Solvent-Assisted SAGD Pilot at Cold Lake, Canada
Authors: Dickson Jasper L. , Scott Clingman , Dittaro Larry M. , Jaafar Ali E. , Yerian Jeffrey A , Perlau Darrel L.
Published: December 2011

ExxonMobil and its affiliate Imperial Oil Resources are currently operating a Solvent-Assisted Steam-Assisted Gravity Drainage (SA-SAGD) experimental pilot plant at Cold Lake, Canada. During pilot operation, up to 20 percent by volume of a light hydrocarbon solvent will be injected with dry steam in a dual horizontal well SAGD configuration. The pilot scope consists of two horizontal well pairs (four wells total), six observation wells, associated steam and solvent injection facilities, artificial lift, and dedicated production measurement and testing facilities.

Previous experimental and computer modeling work completed by the Alberta Research Council (ARC) (Nasr, 2003), Imperial Oil Resources, and ExxonMobil indicates that the addition of solvent to the dry steam increases bitumen production rates and decreases the steam oil ratio (SOR) relative to conventional SAGD processes. A key objective of this pilot is to safely collect high-quality field data to support these findings and quantify process improvement.

This paper will focus on the pilot design approach taken to ensure that the multi-year pilot is successful as well as highlight early pilot performance and operation. Specific design aspects which will be discussed include the choice for the pilot location, the use of detailed geologic models to design and place the horizontal wells, and solvent measurements. Early field results are consistent with expectations. However, longer term operation is required to make a more quantitative assessment. In addition, the pilot operation has demonstrated excellent control of injection pressure, which is critical to the application of this technology in settings with bottom water or top gas.
Effects of Waterflooding and Solvent Injection on the Solvent Vapour Extraction (VAPEX) Heavy Oil Recovery
Authors: Derakhshanfar M. , Jia X. , Jiang T. , Zeng F. , Gu Y.
Published: December 2011

Solvent vapour extraction (VAPEX) process is an economically viable, technically sound, and environmentally friendly in-situ heavy oil recovery method to exploit tremendous heavy oil and bitumen reserves. In this recovery process, significant heavy oil viscosity reduction is achieved through sufficient solvent dissolution and possible asphaltene precipitation. Over the past two decades, several researchers have carefully studied the effects of some major factors on the VAPEX process, such as the test pressure, reservoir porosity and permeability, solvent and heavy oil types, well configuration, and connate water saturation. However, it is unclear how waterflooding and solvent injection will affect a typical VAPEX process.

In this paper, waterflooding and solvent injection effects are experimentally studied by using a visual rectangular sand-packed high-pressure VAPEX physical model with a low permeability. The physical model is packed and then saturated with a heavy oil sample at the connate water saturation. Pure propane and a mixture of n-butane and methane are used as respective solvents to extract two different heavy oil samples. The waterflooding effect is examined by performing a series of VAPEX tests with the initial waterflooding, prior to the subsequent solvent injection/soaking. In addition to the visual observation of the solvent chamber evolution, the heavy oil production rate, produced solvent–oil ratio, and asphaltene content of the produced heavy oil are measured during the waterflooding and solvent injection/soaking. It is found that the initial waterflooding causes an oil production reduction in the subsequent solvent injection. Also solvent breakthrough occurs earlier and a small amount of water is produced afterwards. This is because the initial waterflooding creates some low-resistance channels for the injected solvent to bypass the untouched heavy oil. As a result, the heavy oil is not diluted enough to be produced during the subsequent solvent injection/soaking. In the absence of waterflooding, however, solvent injection alone can increase the heavy oil production in comparison with the solvent-soaking process. Moreover, it is visually observed that solvent injection leads to less asphaltene deposition onto the porous media. This is quantitatively verified by a higher measured asphaltene content of the produced heavy oil at a higher solvent injection rate.
Informing Our Elders About Dialysis
Authors: Schmidt Rebecca J.
Published: December 2011

As the fastest growing sector of the incident ESRD population, older patients constitute a group for which renal replacement therapy has special implications. Older CKD patients have unique needs by virtue of advanced age, high prevalence of comorbid conditions, slower progression of renal disease, and reduced survival. Burdens and risks attendant to dialysis may be amplified in the older patient and patients with impaired functional status or comorbid conditions, and therefore, dialysis may confer little to no survival benefit. Rates of dialysis withdrawal are highest among the oldest patients, raising the possibility that the standard content of informed consent for dialysis warrants an age-sensitive approach that is attuned to the very different balance of pros and cons of dialysis for older patients with multiple comorbidities and younger patients with limited comorbidity. Informed consent for older patients should include presentation of risks, benefits, and burdens associated with dialysis, age-specific estimates of prognosis with and without dialysis, and potential for loss of independence and decline in functional status with initiation of dialysis. In this article, medical evidence and clinical practice guidelines relevant to advance care planning for the older patient with CKD are reviewed, issues to consider in the dialogue with older patients contemplating dialysis are presented, and recommendations for an age-attuned approach to informed consent for older CKD patients are made.
Modeling key interactions between dopamine D2 receptor second extracellular loop and arylpiperazine ligands
Authors: Sukalovic Vladimir , Soskic Vukic , Andric Deana , Roglic Goran , Kostic-Rajacic Sladjana
Published: December 2011

Second extracellular loop (ecl2) of dopamine (DA) D2 receptor is an essential
part of dopaminergic ligands binding pocket. To form a part of the ligand
binding surface it has to fold down into the transmembrane domain of the DA
receptor. The current study describes the modeling of the D2 DA receptor
ecl2 and its interactions with arylpiperazine ligands. In order to model D2
DA receptor ecl2, the number of arylpiperazine ligands was used to propose
pharmacophore model. D2 DA receptor ecl2 model was built using Accelrys
Discovery Studio. To test the proposed model, docking analysis was performed
and key amino acid residues were determined. Proposed receptor-ligand
iteractions were rationalized and compared with measured binding affinity.
It is shown that D2 DA receptor ecl2 significantly participates in
receptor-ligand complex formation through aromatic, hydrophobic and polar
interaction. Taking them in account would benefit GPCR molecular modeling
and facilitate the design of novel active compounds.
Accounting Restatements and the Timeliness of Disclosures
Authors: Badertscher Brad A. , Burks Jeffrey J.
Published: December 2011

SYNOPSIS

Regulators are concerned that during the process of restating financial statements, firms fail to provide timely progress updates, and delay earnings announcements and regulatory filings. To reduce these perceived lags in disclosure, an advisory group to the Securities and Exchange Commission recommends more use of catch-up adjustments rather than restatements to correct accounting errors. Some investor groups oppose the recommendations because they fear that preparers will begin to correct important errors through catch-up adjustments, which are less transparent than restatements.

We inform this debate by examining (1) the length of disclosure lags around restatements to understand the extent of the problem, and (2) the causes of disclosure lags to evaluate whether the reforms would address the root causes of the lags. We find that lengthy lags are uncommon and appear to be largely unavoidable consequences of fraud investigations. When fraud is a factor, the firm typically takes weeks or months to release restatement details, quarterly earnings, and SEC filings, likely because investigations are necessary to restore the firm's ability to produce reliable information. When fraud is not a factor, the firm typically discloses the restatement's earnings impact within a day of the initial restatement announcement, and delays the quarterly earnings announcement and SEC filing by less than a week. Although fraud is by far the most economically significant cause of lags, we also find that lags increase when a restatement involves multiple, long-standing, or large errors. Finally, we show that the restatements targeted by the reforms tend to have the shortest lags, even among non-fraudulent restatements. Thus, the proposed reforms would have a negligible effect on disclosure timeliness because the targeted restatements tend to have short lags to begin with, and because long lags appear to be caused by inherent constraints on producing reliable information.

JEL Classifications: M41, G38.

Data Availability: Data are available from sources identified in the paper.
Perceptions and Misperceptions Regarding the Unqualified Auditor's Report by Financial Statement Preparers, Users, and Auditors
Authors: Gray Glen L. , Turner Jerry L. , Coram Paul J. , Mock Theodore J.
Published: December 2011

SYNOPSIS

U.S. and international auditing standard setters continue to raise questions about standard auditors' reports and are exploring alternatives to those reports. Government agencies and professional organizations are also raising questions about the auditor's report. These questions point to a continued existence of an “audit expectation gap.” To investigate perceptions and misperceptions regarding the auditor's report, we conducted focus groups with five different stakeholder groups—financial statement preparers (CFOs), users (bankers, analysts, and non-professional investors), and external auditors. This approach allows detailed comparisons between the perceptions of the different stakeholder groups affected by the auditor's report. Findings include that financial statement users value the audit, but do not read the entire auditor's report. It is not clear to users, preparers, and auditors what the auditor's report is intended to communicate or the level of assurance being provided by the report. Stakeholders offered numerous suggestions to improve the auditor's report, but they also recognize those suggestions could significantly change the auditor's risk profile and increase audit fees. We suggest future research to determine if potential changes to the auditor's report would change users' behavior and if any resulting benefits outweigh the additional risks and costs.
Predicting the Mean and Variance of Transit Segment and Route Travel Times
Authors: Moghaddam Soroush Salek , Noroozi Reza , Casello Jeffrey M. , Hellinga Bruce
Published: December 2011

Travel time characteristics of transit vehicles such as mean and standard deviation (SD) are of critical importance in both transit planning and operations. Predicting these measures not only helps transit agencies schedule and allocate resources more accurately but also facilitates the development of more robust mode choice and departure time models. Data from automatic vehicle locations and automatic passenger counting, as well as outputs from a travel forecasting model, were used in presenting a methodology to predict the mean and the SD of travel times for proposed transit routes. Models were generated in two ways. First, mean and SD of travel time were estimated by regressing observed values against roadway and operational characteristics. The SD was estimated between origins and destinations by considering the SDs of individual segments and the correlation between segments. Advantages and disadvantages of these two methods were evaluated. The models were calibrated and validated with automatic vehicle location data from the bus system serving the Regional Municipality of Waterloo in Ontario, Canada.
Can River Ferries Deliver Smart Growth?
Authors: Sipe Neil , Burke Matthew I.
Published: December 2011

Brisbane, Australia, introduced catamaran river ferries (CityCats) in 1996 to help reorient the city to its river, to encourage inner city densification, and to spur changes in attitudes toward public transportation. The Brisbane ferry network has grown significantly over the past 14 years and is now a key commuter and tourist transport mode that in 2008 carried 6.28 million passengers, servicing 23 locations throughout the city. Two ferry terminals will be built during the coming years, with private land developers contributing partial funding for one terminal and total funding for the other. Although CityCats seemingly had been used successfully to achieve transit- (or ferry-) oriented development (TOD), a review of key transport and land use planning policy documents found that CityCats had not been used strategically to achieve TOD. This finding suggested that the relationship between the ferries and urban development had been more pragmatic and coincidental, whereas broader strategic planning had been focused more on general smart growth principles and transport planning, and TOD policy had mainly centered on rail and buses. Developments that surround the two new ferry terminals will not be dependent on the ferries for their success; their riverfront location alone ensures success. As with previous nodes on the CityCat network, the primary motivation for developer funding of ferry terminals was as a marketing tool to increase sales.
Index for Estimating Road Vulnerability to Damage from Overweight Vehicles
Authors: Scott Jeremy , Ferrara Gregory P.
Published: December 2011

One component of North Carolina's motor carrier enforcement program is focused on overweight trucks. The aim of this enforcement program is to protect the state's roadway infrastructure, and as such it is important to identify those facilities and roadway segments that are most susceptible to damage from overweight vehicles. For that purpose, a quantitative road vulnerability index (RVI) was developed. Vulnerability is expressed as a function of truck volume, pavement condition, and bridge condition. By weighting these factors, one can assign vulnerability values to road segments statewide. Vulnerable road segments are then mapped in the same geographic information system (GIS) environment used to capture and display motor carrier enforcement activities for overweight violations. In addition to providing information to aid in the spatial assignment of weight enforcement activities, the RVI uses GIS data as a useful tool for the visual analysis and integration of roadway maintenance and operations concerns across various divisions of the North Carolina Department of Transportation.
Life-Cycle Cost-Based Pavement Preservation Treatment Design
Authors: Pittenger Dominique , Gransberg Douglas D. , Zaman Musharraf , Riemer Caleb
Published: December 2011

Classic engineering economic theory was developed to furnish the analyst with a tool to compare alternatives on the basis of life-cycle cost (LCC). However, tools used to apply theory to transportation focus on new construction projects with relatively long service lives. These tools do not accurately model the economic aspects of short-lived alternatives such as those that pavement managers must evaluate when seeking the most cost-effective pavement preservation treatment. The field of pavement preservation seeks to “keep good roads good,” and hence pavement preservation treatments are applied to extend the functional service life of the underlying pavement. No significant research has been done to quantify the actual service lives of the pavement preservation treatments themselves nor has a model been furnished to analyze their LCCs. The paper addresses those two gaps in the pavement economics body of knowledge by proposing a methodology for using field test data to quantify the service lives of pavement preservation treatments for both asphalt and concrete pavements. In addition, the paper concludes that an LCC model based on equivalent uniform annual cost, rather than net present value, specifically addresses the relatively short-term nature of pavement preservation treatments and allows the engineer to better relate treatment LCC output to annual maintenance budgets.
When to Broom or Remove Traffic Control Safely on Fresh Emulsified Asphalt Chip Seals
Authors: Shuler Scott
Published: December 2011

The optimal time to allow brooms to sweep a fresh chip seal is usually determined by experienced field personnel. Factors that affect this decision include aggregate type; aggregate moisture content; emulsion type and grade; application rates of emulsion and aggregate; weather conditions at the site, including humidity, air and pavement temperature, and wind; and number of rollers. Given all these factors, and because changes in one factor can have a significant effect on how an emulsion gains strength and how soon it can resist the forces of brooms and traffic, the decision as to when to allow brooms and traffic on fresh chip seals becomes difficult, at best, to predict. The results of this research suggest that moisture content of the chip seal system is related directly to the strength of an asphalt emulsion residue. Laboratory and field testing confirm that the strength of an asphalt emulsion residue as measured by a modification to the ASTM D7000 sweep test can be used to predict the moisture content level at which a chip seal developed enough strength to resist damage by brooms and vehicular traffic. Three full-scale test pavements were constructed in differing climates, and the results of moisture content testing in the field were compared with modified sweep test results in the laboratory. Results indicated that the three field tests were capable of resisting brooming and traffic damage when the moisture content of the chip seal system ranged between 15% and 25%. This finding correlated well with results of laboratory testing with the modified sweep test on the materials from field tests as well as on experimental laboratory materials.
Sensitivity of ASTM D7000 Sweep Test to Emulsion Application Rate and Aggregate Gradation
Authors: Johannes Petrina Tutumina , Mahmoud Enad , Bahia Hussain
Published: December 2011

Presented in this paper are the effects of emulsion application rate and aggregate gradation on the performance of chip seal samples prepared and tested according to the ASTM D7000 Standard Test Method for Sweep Test of Bituminous Emulsion Surface Treatment Samples (sweep test). Aggregate loss of the samples was used as a performance indicator for chip seals. Limestone and granite aggregates were tested, and each aggregate type was tested with two gradations. Tests were carried out with three emulsion types: CRS-2, HFRS-2L, and HFRS-2. Each emulsion was tested at three application rates. Samples were tested at two different curing times, 2 h and 6 h. Statistical analysis of the chip loss results revealed that the current sweep test was not sensitive to emulsion application rate in the range tested. Results showed that gradation was a statistically significant factor. Coarse-graded aggregates resulted in high aggregate loss compared with fine-graded aggregates. From the overall results of the study, it is concluded that the current sweep test protocol is not suitable for use as a chip seal design tool because of its insensitivity to emulsion application rate. The test, however, is very sensitive to the combination of emulsion type, aggregate mineralogy, and gradation. It is recommended that the procedure be changed to use aggregate gradations representative of field aggregate. It is also recommended that the sweep test, with minor modifications, be used for evaluating compatibility between emulsions and aggregates and for estimating curing times required.
Evaluating Pricing Strategies for Storage in Import Container Terminals
Authors: Saurí Sergi , Serra Jordi , Martín Enrique
Published: December 2011

In most container terminals around the world, storage space is scarce, and pricing policies are needed to increase performance. Specifically, congestion when inbound containers are temporarily stored in terminal yards leads to high operational costs. This paper focuses on the introduction of a yard storage tariff to encourage early pickup of containers. Different from previous approaches, the price schedule introduced has a nonzero flat rate. Both demand reactions and changes in pickup decisions are considered in the analysis. A model is developed for the objective function (profit of the terminal operator). A numerical example illustrates an optimal price schedule, shows how sensitive the profit is to the basic constituents of the model, and provides general pricing rules.
Reducing Train Turn Times with Double Cycling in New Terminal Designs
Authors: Goodchild Anne , McCall J. G. , Zumerchik John , Lanigan Jack
Published: December 2011

North American rail terminals need productivity improvements to handle increasing rail volumes and improve terminal performance. This paper examines the benefits of double cycling in wide-span gantry terminals that use automated transfer management systems. The authors demonstrate that the use of double cycling rather than the currently practiced single cycling in these terminals can reduce the number of cycles required to turn a train by almost 50% in most cases and reduce train turn time by almost 40%. This change can provide significant productivity improvements in rail terminals, increasing both efficiency and competitiveness.
Interrelations of Reaction Time, Driver Sensitivity, and Time Headway in Congested Traffic
Authors: Kim Taewan , Zhang H. Michael
Published: December 2011

Reaction time, driver sensitivity, and time headway are traffic parameters that are critical for understanding and modeling traffic stability and wave propagation. Both theoretical and empirical relationships between these three parameters are examined with vehicle trajectory data. A few clear and distinct relationships are identified, and driver reaction time is found to be closely related to time headway, especially in the deceleration phase. Time headway can be accurately predicted when reaction time and the initial time headway are known. In a traffic simulation, a range of values also exists for the product of driver sensitivity and reaction time to avoid unrealistic speed fluctuations and collisions.
Determining the Effectiveness of an Advance LED Warning System for Rural Intersections
Authors: Weidemann Ryan , Kwon Taek M. , Lund Victor , Boder Brian
Published: December 2011

The majority of intersection-related fatal crashes occur at rural through–stop intersections. At these intersections, sight restrictions caused by vertical and horizontal curves negatively affect a driver's ability to safely accept a gap in the traffic stream. Static advance warning signs are sometimes installed at these intersections to warn drivers on the main through approaches that an intersection is ahead. These warning signs appear to be ineffective. A new advance LED warning system was developed and deployed at a rural through–stop intersection that had limited intersection sight distance because of a severe vertical curve. The warning system actively detected vehicles on all approaches and activated LED blinker warning signs for the conflicting movements. The research project included an analysis of driver behavior at the intersection, obtained through video data, and a survey of local residents and frequent users of the intersection. This paper presents the results of the research conducted to assess the effectiveness of this new LED warning system.
Pedestrian and Bicyclist Violations at Highway–Rail Grade Crossings
Authors: Khattak Aemal , Luo Zheng
Published: December 2011

Each year numerous pedestrian and bicyclist crashes involving high injury levels are reported at highway–rail grade crossings (HRGCs) across the United States. Such crashes are invariably the result of errors on the part of the pedestrians and bicyclists. The focus of this paper is to investigate pedestrian and bicyclist violations at a dual-quadrant gated HRGC and to report on four types of gate violations, including factors associated with those violations. For both pedestrians and bicyclists, the violations studied were (a) passing under descending gates, (b) passing around fully lowered gates, (c) passing under ascending gates, and (d) passing around fully lowered gates between successive trains. Data on pedestrian and bicyclist violations were collected at a grade crossing in Nebraska through the use of video surveillance. Analysis indicated that there were no significant differences in the mean frequencies of pedestrian and bicyclist violations at HRGCs. When data for pedestrians and bicyclists were pooled, 1.27 gate-related violations were recorded per crossing event. Children of around 8 years of age or younger were involved in 25% more gate-related violations than older crossing users (pedestrians and bicyclists). Violations increased with the presence of more individuals at the crossing during train crossing events, but the contribution from young children was greater than that from older crossing users. The implications of the findings for HRGC safety are discussed.
Pulmonary Arterial Hypertension in Systemic Sclerosis Is Associated with Profound Impairment of Microvascular Endothelium-dependent Vasodilatation
Authors: HOFSTEE HERMAN M.A. , VOSKUYL ALEXANDRE E. , VONK NOORDEGRAAF ANTON , SMULDERS YVO M. , POSTMUS PIET E. , DIJKMANS BEN A.C. , SERNÉ ERIK H.
Published: December 2011

Objective.

Impaired microvascular function may contribute to organ complications in patients with systemic sclerosis (SSc). We investigated whether SSc patients with and without pulmonary arterial hypertension (PAH) show a graded impairment of microvascular function compared to healthy controls.

Methods.

Twenty-two patients with SSc and 22 controls were studied. All patients underwent right heart catheterization; 6 had no PAH (SSc-nonPAH) and 16 had PAH (SSc-PAH). Acetylcholine (ACh)-mediated endothelium-dependent vasodilatation and sodium nitroprusside (SNP)-mediated endothelium-independent vasodilatation were assessed by iontophoresis combined with laser Doppler flowmetry.

Results.

Compared to sex- and age-matched controls, ACh-mediated vasodilatation was reduced in SSc-PAH (340.4% vs 79.5%, respectively; p < 0.01), but not in SSc-nonPAH (340.4% vs 397.9%; p = 0.90). No significant differences were present between the groups in SNP-mediated vasodilatation.

Conclusion.

Systemic microvascular endothelium-dependent vasodilatation is markedly reduced in SSc complicated by PAH.
Effectiveness of Rituximab in Patients with Rheumatoid Arthritis: Observational Study from the British Society for Rheumatology Biologics Register
Authors: SOLIMAN MOETAZA M. , HYRICH KIMME L. , LUNT MARK , WATSON KATH D. , SYMMONS DEBORAH P.M. , ASHCROFT DARREN M. ,   the British Society for Rheumatology Biologics Register
Published: December 2011

Objective.

To assess the effectiveness of rituximab (RTX) in patients with rheumatoid arthritis (RA) in routine clinical practice, and to identify predictors of 6-month response to RTX in patients for whom at least 1 anti-tumor necrosis factor-α (anti-TNF) therapy has failed.

Method.

The analysis involved 646 patients with RA registered with the British Society for Rheumatology Biologics Register (BSRBR) who were starting RTX and were followed for at least 6 months. Change in the 28-joint Disease Activity Score (DAS28), European League Against Rheumatism (EULAR) response, and proportions of patients achieving disease remission were used to assess the clinical response 6 months after starting RTX. Regression analyses were used to identify factors associated with the response in the patients for whom anti-TNF therapy had not worked. The models included baseline demographics, disease characteristics, baseline Health Assessment Questionnaire (HAQ), and drug history including biologic history.

Results.

The mean DAS28 at baseline was 6.2 (95% CI 6.1, 6.3), which decreased significantly to 4.8 (95% CI 4.7, 4.9) at the 6-month followup. Seventeen percent of the patients were EULAR good responders and 43% were moderate responders. Eight percent of the patients achieved disease remission. Subjects with higher baseline DAS28 score and those with positive rheumatoid factor (RF) status were significantly associated with a decrease in their DAS28 score (improvement), while women and patients with higher baseline HAQ score were less likely to improve.

Conclusion.

RTX has proven to be effective in routine clinical practice. When anti-TNF therapy fails, response to RTX was influenced by baseline DAS28 score, RF status, baseline HAQ score, and sex.
Digital Natives and H1N1
Authors: Woodhead Peter , Kennedy David M.
Published: December 2011

This paper examines what happens when young learners in a primary school in Hong Kong start from learning about information and communication technologies (ICTs) to learning with and through ICTs. The authors focus on how students used learning technologies when an H1N1 outbreak closed the school for three weeks and teachers were required to use ICTs to initiate at-home learning. This gave the researchers an opportunity to assess the capacity of young students using Web 2.0 technologies to support learning and the impact that these tools have on teacher views and practice. Data includes interviews with teachers and examples of students’ work. Findings demonstrate how confident and comfortable young learners are with new technologies, raising questions about prevailing assumptions that young students have the capacity to easily use the existing school-based learning management system and Web 2.0 applications. The authors provide evidence that students can effectively engage with ICTs and demonstrate very high levels of skills. However, students did not do so automatically, and required assessment tasks were often key drivers for initiating student engagement and learning.
Requirements and Properties of Qualified Electronic Delivery Systems in eGovernment
Authors: Tauber Arne
Published: December 2011

Electronic mailing systems are the dominant communication systems in private and business matters. Public administrations deliver documents to citizens and businesses—subpoenas, legal verdicts, notifications, administrative penalties, and so forth. However, official activities are more strongly bound to legal regulations than in civil law. Delivery of crucial and personal documents raises the demand for qualified identification and non-repudiation services as featured by registered and certified mail in the paper world. Legal requirements for electronic delivery carried out by public administrations (eDelivery) cannot be fulfilled by standard mailing systems. Although the requirements for eDelivery systems may differ due to national legal regulations, this paper discusses common requirements and properties on an abstract level. Moreover, the author shows how these requirements have been addressed by introducing the Austrian eDelivery system for eGovernment applications.
Examining Diffusion and Sustainability of E-Learning Strategies through Weblog Data
Authors: Lam Paul , Lo Judy , Yeung Antony , McNaught Carmel
Published: December 2011

The study focuses on ‘horizontal’ and ‘vertical’ adoption of e-learning strategies at The Chinese University of Hong Kong as revealed through computer log records in the centrally supported learning management systems. Horizontal diffusion refers to whether e-learning has spread to influence the practice of more teachers and students. In vertical diffusion, the authors examined whether or not teachers tend to adopt more varied online learning activities in successive years. The overall findings are that, while adoption of simple strategies is increasing, there is little evidence of horizontal and vertical diffusion of more complex strategies. Indeed, the use of some of the more complex strategies, which may relate to greater potential learning benefits, decreased. Results have led to discussions about new focuses and strategies for our institutional eLearning Service.
Predictive File Replication on the Data Grids
Authors: Liao ChenHan , Helian Na , Wu Sining , Rashid Mamunur M.
Published: December 2011

Most replication methods either monitor the popularity of files or use complicated functions to calculate the overall cost of whether or not a replication decision or a deletion decision should be issued. However, once the replication decision is issued, the popularity of the files is changed and may have already impacted access latency and resource usage. This article proposes a decision-tree-based predictive file replication strategy that forecasts files’ future popularity based on their characteristics on the Grids. The proposed strategy has shown superb performance in terms of mean job time and effective network usage compared with the other two replication strategies, LRU and Economic under OptorSim simulation environment.
G2G
Authors: Chung Wu-Chun , Hsu Chin-Jung , Lin Yi-Hsiang , Lai Kuan-Chou , Chung Yeh-Ching
Published: December 2011

Grid systems integrate distributed resources to form self-organization and self-management autonomies. With the widespread development of grid systems around the world, grid collaboration for large-scale computing has become a prevalent research topic. In this paper, the authors propose a meta-grid framework, named the Grid-to-Grid (G2G) framework, to harmonize autonomic grids in realizing a grid federation. The G2G framework is a decentralized management framework that is built on top of existing autonomic grid systems. This paper further adopts a super-peer network in a separate layer to coordinate distributed grid systems. A super-peer overlay network is constructed for communication among super-peers, thus enabling collaboration among grid systems. This study proposes the G2G framework for use in a Grid-to-Grid federation and implements a preliminary system as a demonstration. Experimental results show that the proposed meta-grid framework can improve system performance with little overhead.
Handoff Cost Minimization and Planning of Heterogeneous Integrated Overlay Networks
Authors: Paul Ayan , Maitra Madhubanti , Mandal Swarup , Sadhukhan Samir Kumar
Published: December 2011

The wireless technology market has witnessed a complete paradigm shift as multiple standards and protocols are emerging almost every day. Each and every standard has its limitations and merits, which can be either masked or complemented by some other standards. The demands from the service providers are now sky-high and for the complete commercialization, it is expected that even with scarce network resources all kind of services would be provided, especially in a cost effective manner. This burning issue compels a service provider to roll out some integrated wireless networks to exploit the virtues of each. This chapter formulates the planning problem of an overlay network integrating particularly, 3G, WiMAX, and WLAN. The issue of planning is to establish proper connectivity amongst the three network standards which is unique in its nature. In the proposed planning approach, the authors have endeavored to minimize total cost for vertical handoff generated in the overlay network as well as the cost for wire line connection amongst the various network gateways of the overlay hierarchy. In this work, the authors have focused on the initial planning phase. For validating the novel planning problem, the chapter has taken recourse to simulated annealing (SA) and a well cited meta-heuristic H-II. The authors have also presented comparison of the performances of SA and H-II with a variant of distance based planning (DBP) scheme in this domain.
QoS-Aware Scheme for Mobility Management and Adaptive Resource Reservation in 4G Wireless Networks
Authors: Trabelsi Sihem , Boudriga Noureddine
Published: December 2011

Simulations show that the proposed scheme achieves better results than those of other resource reservation schemes for metrics like bandwidth utilization, handoff latency, and packet loss.
Secure Route Discovery in DSR against Black Hole Attacks in Mobile Ad Hoc Networks
Authors: Subathra P. , Sivagurunathan S.
Published: December 2011

A Mobile Ad hoc Network (MANET) is a collection of wireless nodes communicating over multi-hop paths without any infrastructure. Nodes must cooperate to provide necessary network functionalities. The security in routing protocols like Dynamic Source Routing (DSR) can be compromised by a “Black Hole” attack. Here, a malicious node claims to have the shortest path to the destination and attracts all traffic and drops them, leading to performance degradation. The situation becomes worse when two or more nodes cooperate and perform the “Cooperative black hole” attack. This chapter proposes a solution based on probing to identify and prevent such attacks. The proposed solution discovers a secure route between the source and destination by identifying and isolating the attacking nodes. Simulation results show that the protocol provides better security and performance in terms of detection time, packet delivery ratio, and false negative probability in comparison with trust and probe based schemes.
Interoperable IPv6 Sensor Networking over PLC and RF Media
Authors: Chauvenet Cedric , Tourancheau Bernard , Genon-Catalot Denis , Goudet Pierre-Emmanuel , Pouillot Mathieu
Published: December 2011

The evolution of technology has made the connection of all types of devices to IP networks possible. In this paper, the authors investigate the possible usage of IPv6 in sensor networks connected through the Power Line Communication (PLC) non-wireless medium and demonstrate possible interoperability. This work is based on the adaptation of the IEEE 802.15.4 standard protocol constrained by the low-power, lossy and low data-rate context of PLC transceiver that uses pulse modulation. The aim is to provide interoperability features with other media using a robust and reliable communication stack. The target application of such results ranges from smart metering and environment monitoring to home control and urban area energy efficiency applications. This paper proposes the first adaptation of the IEEE 802.15.4 standard commons for the PLC medium. Following this standard interface, the authors demonstrate data communication on PLC with low power energy requirement using the pulse PLC physical layer. This paper also presents an initial implementation of the Routing Protocol for Low power and lossy networks (RPL) setup proposed by the IETF working group. In this context, the authors demonstrate interoperability in a testbed between PLC and Wireless Sensor Networks (WSN).
Technology in the Special Education Classroom
Authors: Rodriguez Blanca
Published: December 2011

Prairie School District believes in integrating technology into classroom learning for all students. However, for some schools “all students” does not include the special education population. Rolando was a 7 year old autistic boy additionally labeled with mental retardation. Pretend you were Rolando’s teacher. Would you have done differently?
Cyber Gangs inside the Classroom
Authors: Martinez Evelyn
Published: December 2011

Students in classrooms face challenges of which teachers and adults are either unaware or simply do not notice. Jonathan’s parents nor his teachers knew about the difficult situation Jonathan was experiencing with his classmates. Like so many parents and teachers, they did not have any reason to suspect that ten-year-old Jonathan was a victim of a cyber gang’s activities occurring right in his own living room and inside his classroom.
How Do We Close the Gap between Technology Innovation and Available Funding?
Authors: McGlory Christian
Published: December 2011

Roosevelt School District, a small urban elementary school district, is trying to find a way to purchase new digital technology for campuses. The bases of this case study are to develop a plan for how the district can pay for new technology.
A High School Librarian’s Participation in Supporting Information Literacy on Her Campus
Authors: Ramirez Diana
Published: December 2011

The ability to navigate the web and to use technology effectively and efficiently is no longer an option but a requirement in schools and in the workplace. Information literacy is widely accepted as embracing rapid advances in technologies and recognizing the multiple literacies required of students living and learning in this century. Information literacy has grown to include traditional literacy, computer literacy, media literacy, and network literacy. School library media specialists in the twenty-first century face both challenges and opportunities in the recent high expectations of information literacy. Among the challenges is keeping up with changing technologies and taking the necessary steps to ensure students and teachers have appropriate access to resources and instruction. Opportunities include the chance to transform today’s library into a resource center of the future where information literacy can be easily obtained. Welcome to the world of Ms. West, a middle school teacher turned high school librarian, and see how she ponders upon her new role as being the instructor/specialist of information literacy skills on the campus, a reading advocate and provider of reading materials, as the manager of the resources both information and library resources, and lastly being a collaborator with teachers concerning information literacy issues.
Case Study of Game-Based Learning in a Citizenship Education K-12 Classroom
Authors: Olla Venus
Published: December 2011

This chapter focuses on a case study that involves the incorporation of ICT in particular gaming technology into the subject area of Citizenship Education (CE), a non-traditional ICT focused subject. The case study is within the context of a K-12 classroom and it explores the processes in which a classroom teacher may have to navigate to be able to use innovative ICT within their classroom. The case highlights the main issues as relating to pedagogical and institutional considerations.
ABCs and PCs
Authors: Hansen Cory Cooper
Published: December 2011

Effective professional development holds the power to transform teaching practices that invigorate teachers and increase student engagement. Arizona Classrooms of Tomorrow Today (AZCOTT) was one such experience. Eighteen elementary teachers completed a yearlong, rigorous, sixty-hour workshop experience that focused on integrating technology in content area instruction. Participants integrated technology effectively, began to develop leadership skills, and experienced changes in attitude, beliefs, knowledge, and skills as technology influenced existing curricula.