bluuebunny/crossref_metadata_2025 huggingface dataset:
A Heuristic Image Search Algorithm for Active Shape Model Segmentation of the Caudate Nucleus and Hippocampus in Brain MR Images of Children with FASD
Authors: Eicher A A , Marais P , Warton C , Jacobson S W , Jacobson J L , Molteno C D , Meintjes E M
Published: September 2015

Magnetic Resonance Imaging provides a non-invasive means to study the neural correlates of Fetal Alcohol Spectrum Disorder (FASD) - the most common form of preventable mental retardation worldwide. One approach aims to detect brain abnormalities through an assessment of volume and shape of two sub-cortical structures, the caudate nucleus and hippocampus. We present a method for automatically segmenting these structures from high-resolution MR images captured as part of an ongoing study into the neural correlates of FASD.

Our method incorporates an Active Shape Model, which is used to learn shape variation from manually segmented training data. A modified discrete Geometrically Deformable Model is used to generate point correspondence between training models. An ASM is then created from the landmark points. Experiments were conducted on the image search phase of ASM segmentation, in order to find the technique best suited to segmentation of the hippocampus and caudate nucleus. Various popular image search techniques were tested, including an edge detection method and a method based on grey profile Mahalanobis distance measurement. A novel heuristic image search method was also developed and tested. This heuristic method improves image segmentation by taking advantage of characteristics specific to the target data, such as a relatively homogeneous tissue colour in target structures.

Results show that ASMs that use the heuristic image search technique produce the most accurate segmentations. An ASM constructed using this technique will enable researchers to quickly, reliably, and automatically segment test data for use in the FASD study.
An Empirical Study Of User Acceptance Of Online Social Networks Marketing
Authors: Mulero Olumayowa , Adeyeye Michael
Published: September 2015

The explosion of Internet usage has drawn the attention of researchers towards online Social Networks Marketing (SNM). Research has shown that a number of the Internet users are distrustful and indecisive, when it comes to the use of social networks marketing system. Therefore, there is a need for researchers to identify some of the factors that determine users’ acceptance of social networks marketing using Technology Acceptance Model (TAM). This study extended the Technology Acceptance Model theoretical framework to predict consumer acceptance of social networks marketing within Western Cape Province of South Africa. The research model was tested using data collected from 470 questionnaires and analysed using linear regression. The results showed that user intentions to use SNM are strongly and positively correlated with user acceptance of using SNM systems. Empirical results confirmed that perceived credibility and perceived usefulness are the strongest determinant in predicting user intentions to use SNM system.
iSemServ: A model-driven approach for developing semantic web services
Authors: Mtsweni Jabu , Biermann Elmarie , Pretorius Laurette
Published: September 2015

The benefits of incorporating Semantic Web Services in web applications are well documented. However, both the real-world implementation and adoption of these services are still rather limited in practice. This is despite the promises that extend syntactic Web services with capabilities such as automatic service discovery, composition, and execution. Some of the barriers to the real-world implementation are the complexities and tool support related to the development of Semantic Web Services. In this article, the main challenge that is addressed is the tight coupling of existing Semantic Web Services (SWS) development platforms to specific semantic description languages and service description languages, which unintentionally lead to unbending service development environments. The main contribution in this article is therefore a model-driven approach called iSemServ that exploits mature technologies, such as UML, and model-transformation techniques for simplifying and semi-automating the development of SWS using description languages of choice, such as Web Ontology Language for Services (OWL-S) and Web Application Description Language (WADL). A design science research methodology was employed in conducting the study. The suggested approach was practically implemented as an Eclipse plug-in and evaluated based on a real-world use case scenario and comparative analysis of related solutions. The evaluation results show that our proposed solution is relevant and appropriate in aiding the semi-automatic development of SWS, albeit with a number of limitations that could be addressed by extending the proposed practical solution.
Factors in Adoption of e-Learning in the Mining Industry of South Africa
Authors: Matthee Machdel , Henneke Marius , Johnson Roy
Published: September 2015

The mining industry in South Africa contributes significantly to its economy. Training is an important component in these environments and e-Learning is often used to train the large workforce. In the face of current labour unrest and job cuts in this sector, it is foreseen that e-Learning might play an increasing important role to upskill the remaining work force. However, it appears that low motivation and resistance to e-Learning exist amongst learners. The aim of this research was to examine the factors that may contribute to this resistance and/or adoption from the perspectives of e-Learning managers and practitioners. Activity theory was used as the theoretical lens and its main elements (tools, subjects, rules, objects, community) were used to analyse interviews with participants from two mining companies. Potential contradictions were identified in order to explore resistance to e-Learning. The main findings indicate that: 1) proper communication of expectations by different stakeholders of e-Learning is imperative, 2) top management support for e-Learning should stem from integration into the organisational goals, 3) more attention should be given to interaction between learners and facilitators and also between learners, 4) a focus on people development rather than only compliance may lead to lower resistance, and 5) top management support and involvement should be made visible.
The Expatriate Flow Model - Towards understanding Internet usage in Kingdom of Saudi Arabia
Authors: Hattingh Marie
Published: September 2015

Expatriate adjustment research has identified a number of challenges that expatriates experience when adjusting to the host country. These include spousal influence, cultural training/understanding, fluency in the host language and personality or emotional readiness of the expatriate. These challenges are amplified when it is considered in the Kingdom of Saudi Arabia (KSA), which has large cultural distance when compared to an average Western culture and therefore provides a setting for an interesting study. This ongoing study has thus far proposed a theoretical model derived by following Glaser’s Grounded Theory Methodology (GTM). This paper will report on a specific aspect of this proposed model namely the substantive category “degree of flow” which extends the previous discussion of “degree of isolation”. Within the proposed theoretical model, the “degree of flow” experienced by expatriates influences the “degree of isolation” experienced by expatriates. This paper describes how the Flow Theory was operationalized at affective level to aid the understanding of the emotional relationship expatriates in KSA have with the Internet. An expatriate flow model was developed based on the generally accepted three stages of Flow Theory namely: Antecedents to Flow, Experience of Flow and Consequences of Flow.
Hardware Genetic Algorithm Optimization by Critical Path Analysis using a Custom VLSI Architecture
Authors: Smith Farouk , Van den Berg Allan Edward
Published: September 2015

This paper propose a Virtual-Field Programmable Gate Array (V-FPGA) architecture that allows direct access to its configuration bits to facilitate hardware evolution, thereby allowing any combinational or sequential digital circuit to be realized.

By using the V-FPGA, this paper investigates two possible ways of making evolutionary hardware systems more scalable: by optimizing the system’s genetic algorithm (GA); and by decomposing the solution circuit into smaller, evolvable sub-circuits. GA optimization is done by: omitting a canonical GA’s crossover operator (i.e. by using a 1+λ algorithm); applying evolution constraints; and optimizing the fitness function.

A noteworthy contribution this research has made is the in-depth analysis of the phenotypes’ CPs. Through analyzing the CPs, it has been shown that a great amount of insight can be gained into a phenotype’s fitness.

We found that as the number of columns in the Cartesian Genetic Programming array increases, so the likelihood of an external output being placed in the column decreases. Furthermore, the number of used LEs per column also substantially decreases per added column.

Finally, we demonstrated the evolution of a state-decomposed control circuit. It was shown that the evolution of each state’s sub-circuit was possible, and suggest that modular evolution can be a successful tool when dealing with scalability.
User-centered applications: Use of mobile information technologies to promote sustainable school healthcare services
Authors: Veldsman Alida , Van Greunen Darelle , Mashapa Job
Published: September 2015

The youth, especially school going children, are the future of any society. It is therefore important that children should receive adequate healthcare support at an early age in order to strive to preserve and ensure better education and welfare of the children and continuity in societal success. Despite the strategic initiatives that aim at improving the general health of school going children, such as South Africa’s Integrated School Health Policy, there still exist challenges in support programmes meant to alleviate the barriers to effective healthcare towards improved education for the school children.

Advances in ICT enable a fundamental redesign of healthcare processes based on the use and integration of electronic communication at all levels. New communication technologies can support a transition from institution centric to user-centric applications. This paper defines key principles and challenges for designers, policy makers, and evaluators of user-centred technologies for healthcare in schools. The paper employs the User Experience Management Model (UXM2) to review the current and emerging trends, and highlights challenges related to the design of a typical m-ICT application that supports delivery of healthcare in schools. The paper reaches conclusions for next steps that will advance the domain.
Ecosystem engineering by a gall‐forming wasp indirectly suppresses diversity and density of herbivores on oak trees
Authors: Wetzel William C. , Screen Robyn M. , Li Ivana , McKenzie Jennifer , Phillips Kyle A. , Cruz Melissa , Zhang Wenbo , Greene Austin , Lee Esther , Singh Nuray , Tran Carolyn , Yang Louie H.
Published: September 2015

Ecosystem engineers, organisms that modify the physical environment, are generally thought to increase diversity by facilitating species that benefit from engineered habitats. Recent theoretical work, however, suggests that ecosystem engineering could initiate cascades of trophic interactions that shape community structure in unexpected ways, potentially having negative indirect effects on abundance and diversity in components of the community that do not directly interact with the habitat modifications. We tested the indirect effects of a gall‐forming wasp on arthropod communities in surrounding unmodified foliage. We experimentally removed all senesced galls from entire trees during winter and sampled the arthropod community on foliage after budburst. Gall removal resulted in 59% greater herbivore density, 26% greater herbivore richness, and 27% greater arthropod density five weeks after budburst. Gall removal also reduced the differences in community composition among trees (i.e., reduced beta diversity), even when accounting for differences in richness. The community inside galls during winter and through the growing season was dominated by jumping spiders (Salticidae; 0.87 ± 0.12 spiders per gall). We suggest that senesced galls provided habitat for spiders, which suppressed herbivorous arthropods and increased beta diversity by facilitating assembly of unusual arthropod communities. Our results demonstrate that the effects of habitat modification by ecosystem engineers can extend beyond merely providing habitat for specialists; the effects can propagate far enough to influence the structure of communities that do not directly interact with habitat modifications.
The relevance of socioeconomic interactions for the resilience of protected area networks
Authors: Maciejewski K. , Cumming G. S.
Published: September 2015

Ecological theory suggests that intermediate connectivity between protected areas will increase their resilience by facilitating dispersal, recolonisation, and genetic mixing. Conversely, over‐connectivity may make areas less resilient to contagious perturbations such as pathogen outbreaks. In a similar manner, socioeconomic connectivity should enhance the spread of effective management strategies and the sharing of scarce resources, but over‐connectivity carries the risks associated with one‐size‐fits‐all strategies. We used network analysis to examine the topology of management collaborations and related exchanges of information and equipment in two protected area networks in South Africa using the Eastern and Western Cape Provinces as study sites. National protected areas displayed the highest degree of centrality in the Western Cape, while provincial protected areas occupied the central role in the Eastern Cape. Managers in the Western Cape were more concerned about establishing ecological connectivity between protected areas whereas tourism emerged as an important driver in the Eastern Cape protected area network. Our results support the argument that both location and network membership are important for the socioeconomic resilience of protected areas. As with ecological corridors, deliberate fostering of particular socioeconomic corridors may make the protected areas more resilient to perturbations.
Formation Evaluation in Tight Clastic and Carbonate Formations: A Malay Basin Case Study
Authors: Kyi K.. , Haddad S. S. , Chouya S.. , Wa W.. , Johan Z. J.
Published: September 2015

Tight heterogeneous clastic and carbonate formations present great challenges in terms of reservoir fluid characterisation and downhole fluid sampling during exploration phase. The low mobility imposed by the tight clastic formations usually prohibits conclusive formation testing and sampling using conventional wireline formation testers (WFT) with single probe. The small flow area provided by single probe typically does not allow single phase reservoir fluid withdrawal in such low mobility environment due to the high pressure drawdown. In addition, the optimisation of pressure drawdown is critical to ensure single phase and representative downhole reservoir fluid sampling within the allowed station time. On the other side, the heterogeneous nature of the carbonate pore system imposes a significant mobility range, varying from very tight to good permeability intervals. Pinnacle reef carbonates are often naturally fractured. The natural fracture system may cause fluid losses resulting in drilling and data acquisition challenges. Detailed planning and careful consideration on various testing options available is needed to address this high mobility variation and subsequently to maximise the data acquisition at minimum operation cost, time and risks.

This work presents case studies demonstrating a new WFT approach in appraising tight laminated sandstone and carbonate reservoirs in offshore Malaysia fields. An initial attempt with conventional technology did not allow to obtain any conclusive formation pressure measurement, pressure gradients, downhole reservoir fluid identification and sampling. On the other hand, the application of WFT Dual Packer offers limited pressure drawdown range and requires extended station time usually resisted by drillers. Realising the importance of these exploration wells to verify potential reserves from initial geological and petrophysical data, it became crucial to search for an alternative technology to achieve the fluid evaluation objectives in a time-effective manner.

This paper presents a new approach and methodology that was implemented and resulted in reliable reservoir rock pressure, mobility, and sampling while improving operational efficiency. As a result, it was possible to successfully evaluate the reservoirs of interest and meet study objectives.

This work will also provide a proposed best practice, workflow, and recommendations supported by field data examples.
Innovative Impregnated Drill-Bit Design with Enhanced Durability Improves Performance in Challenging Algerian Application
Authors: Gadallah Khaled , Richert Volker , Burch Connie
Published: September 2015

Vertical wells are drilled in the In Aminas field in Algeria with various types of drill bits, including polycrystalline diamond compact bits (PDC), tungsten carbide insert bits (TCI), and impregnated (impreg) drill bits. The operator tested a new 6-in impregnated bit with novel cutting structure concepts in an attempt to drill the section in one run. The bit was used on rotary BHA, and high speed motor BHA for two runs in the same section.

Both runs did well, and the bit maintained the sharp cutting structure till the TD of the section.

The 6-in section comprises mulitple layers of hard abrasive sandstone with unconfined compressive strength up to 35 KPSI, loose shale which is relatively soft and ends with metamorphic rock.

The new impregnated bit uses diamond segments imbedded in blades comprising diamond-grit matrix material to create a cutting structure with variable wear along the bit face. This particular combination of diamond and matrix improved overall aggressiveness and durability in the shoulder.

To drill efficiently, impregs are paired with high-speed motors or turbines. The new design successfully drilled on two different BHAs. The first was a rotary-packed BHA that drilled 406.8 ft (124 m) at 4.33 ft/hr (1.32 m/hr). The bit didn't show signs of wear and was used on a second BHA with a high-speed motor that drilled another 603.7 ft (184 m) at 6 ft/hr (1.8 m/hr). The impreg's overall performance was 1,010 ft (308 m) at 5.2 ft/hr (1.6 m/hr), and the bit pulled out of hole in a very good condition.

The solution enabled the operator to drill 200% further, more than the best offsets and saving multiple bit trips, which resulted in total savings of USD 195,000.

This article will explain the benefits of the new technology and discuss how this novel impregnated bit successfully drilled the section in one run which is the first time ever to happen.
Continues Update for PetroSilah Full Fields Development Plan Results of Production and Reserves
Authors: Abdalla Omar Shehata , Shawky Mohamed , Badawy Omar , Maarouf Mounier , kamal Youssuf
Published: September 2015

Field development planning is one of the core business processes in the upstream oil and gas industry. Before a discovered field can be developed and its hydrocarbon produced, proper evaluation and planning of the subsurface reservoirs and surface facilities are necessary to ensure that the field development plan is not only economical to undertake, but also flexible enough to cater for any deviation from the original plan during implementation as a result of inherent uncertainties in the reservoirs over the production life span of the field.

This paper describes the approach taken to prepare a Field Development Plan (FDP) for one of the old mature fields in the western desert of Egypt which operated by PetroSilah Petroleum Company in the concessions area in El-Fayoum, 90 Km south of Cairo. PetroSilah Petroleum Company operates more than 15 mature fields with very limited sand structure and depletion drive reservoirs mechanism, two common denominators among these fields is the high pour point of the produced oil and the lake of surface facilities for crude assembling and shipping since crude oil is transported by trucks.

The driver for this FDP was the requirement to maximize and improve existing field's production, starting 3rd quarter of 2012 FFDP initiated when total daily production rate of PetroSilah was 3500 BOPD such as work-over/re-completions campaign, new infill development and exploratory/appraisal wells have been drilled in addition to hydraulic fracture campaign and water injection project which started in some fields and preparation for other existing have been applied, results showed an increase of total average daily production up to 7000 BOPD.

The key areas emphasized in the preparation of the field development plan include the business driver, resource assessment, depletion strategy, development concept and selection, managing uncertainties, appraisal requirements, reservoir management, and anticipating production problems.
Static Model QC: Technical Aspects and Practice from A to Z
Authors: Noureldien Darhim M. , Merghany Ibrahim
Published: September 2015

Petroleum Industry has a lot of uncertainties and risks in each element of its different domains starting from exploration reaching to production. Different tools are being used in order to minimize those uncertainties especially in characterizing reservoirs and defining the optimum development strategies for them. One of the most powerful tools is the numerical reservoir simulation which is considered the state of the art technique since 1990's. Numerical reservoir simulation uses certain geological and engineering findings and predicts the reservoir performance in the future stochastically. It helps a lot in maximizing the asset value and hence the project economics.

Geological Model or what is called “Static Modeling” is the most important stage in the reservoir modeling process at which we build our model to capture all structural, stratigraphical and petrophysical features. The static model is usually built by the geoscientists then delivered to the engineer to start feeding the model with the dynamic data (e.g. PVT, SCAL, Production, Pressure, VLP… etc.). But before feeding the static model, each reservoir engineer must check the quality of the Static Model to assure certain feature such as; it had been coarsened or upscaled properly, it can really mimic the fluid flow directions, it can be run by numerical solvers available in commercial Simulators without any convergence error, it is valid for the purpose it was built for and much more others.

That's why it is very important for each engineer that is willing to work on static models to have a road map of what he/she should do and what type of interactions with geoscientists needed in order to QC the static model before getting it to be Dynamic Model. Indeed, we generalized definite steps which can be considered as a template for any reservoir engineer to follow when he/she approaches to QC any static model. Those steps include all the QC elements starting from Structural aspects like faults modeling reaching to matching with electric logs and facies description. Not only the Static Model QC but also we proposed many recommendations during the Upscaling stage and how to keep your model as simple as you can. All of those were stated clearly combined with some technical details behind each step to let engineers be aware of the technicality in background and its impact.

This paper is important for any engineer dealing with reservoir modeling which will provide him with a general scheme to follow whilst QC'ing the model. This paper also targets the methodology to obtain well-defined model in order to have a better realization of our reservoir and hence better FDP and maximum asset value which is the ultimate target for any E&P company in our world.
Cyclic Group Steaming of Wells (CGSW): A Case Study in Issaran Egypt Field
Authors: Korany S. K. , Hassan W.. , Basta G. S. , Kortam W. T. , Coutry S. N. , Shokry K. S.
Published: September 2015

This paper describes a case study of cyclic group steaming of wells (CGSW) in a heavy oil (10-12 API) field located in Egypt. The field is known as Issaran with approximately 1.2 billion barrels of oil in place. CGSW was implemented in a pilot in a highly fractured limestone reservoir, with highly permeable fractures. During cyclic steam injection in the pilot, a negative effect was noticed during steam injection in some wells on surrounding wells; the gross production rate increased accompanied by an increase in water cut and wellhead temperature leading to loss in oil production. This meant that steam injection strategy needs some modifications

To avoid this, CGSW was implemented by applying steam cycles in all the producers of the pilots simultaneously, allowing for a better distribution of heat around all the wells.

Cyclic steam injection of all wells together implies pressurizing the reservoir, and hence increasing the reservoir energy along with decreasing the oil viscosity and enhancing the ultimate oil recovery. This, together with eliminating the negative effect of steam injection from the neighboring wells allowed the wells to show a better performance

Comparison is made between some of the wells producing before and after CGSW. The results are shown along with a full description of the process.
Steerable Drilling Liner Matches the Industry's Common Theme Regarding Cost Optimization Approaches and minimize Geomechanics Related Challenges; Technology Overview, Applications and Limitations
Authors: El Sherbeny Wael , Biscaro Enrico , Merie Ibrahim , Mayer Heinrich , Dabyah Ali Al
Published: September 2015

Because fracture gradient changes with rock type, some formations are more sensitive to induced fractures than others. Depending upon depth, the fractures created will either be horizontal or vertical. If the depth is 2500 feet or less, horizontal fractures are usually produced. Because horizontal fractures require lifting the entire overburden, they are limited to shallow depths. At depths over 3500 feet, fractures are usually vertical. Because vertical fractures occur without lifting the overburden, they can be created at much lower pressure. The propagation pressure is generally much less than the pressure that would be required to initiate the fracture. Consequently, fracture losses, once initiated, are difficult to control.

Wellbore instability, particularly in shale formations, is a major challenge in drilling operations. Many factors such as rock properties, in-situ stresses, chemical interactions between shale and drilling fluids, and thermal effects must be taken into consideration in well trajectory designs and drilling fluid formulations to mitigate wellbore instability-related problems.

The Steerable Drilling Liner service combines a rotary steerable system with a liner to help overcome the challenges: drilling in zones with lower pressure and unstable shale/coal layers, and with formations of varying flow and pressure regimes. Running the liner while drilling keeps the wellbore stable and eliminates the need to pull the drillstring to run casing. This is how it reduces your risks and NPT, saving the costs associated with contingency plans. Because the liner is isolated from the reamer shoe, you can rotate the liner at much lower RPMs than the pilot and reamer bits. This design lessens the load on the liner, improving its fatigue life.

The Steerable Drilling Liner steerable drilling liner service helps you to mitigate the risk of hole collapse and formation damage by reducing openhole exposure, Reduce NPT by eliminating extra trips and ensuring that the liner is installed at TD from the first run

Enhance wellbore integrity by drilling with the liner, leading to the plastering effect, which reduces fluid loss and cuttings volume, Lower health, safety, and environmental (HSE) risks by reducing pipe handling and rigsite footprint size

Steerable Drilling Liner service developed and qualified using a rigorous processes including extensive onshore testing at the service provider Experimental Test Area (BETA) facility before being successfully deployed offshore. Rely on Steerable Drilling Liner service performance in extreme environments; the cost-effective Steerable Drilling Liner service promotes wellbore stability and performs reliably in the challenging downhole environments. This Paper will reveal the technology overview, updates, case histories and field limitations
Zn(Ta1-xNbx)2O6 nanomaterials: Synthesis, characterization and corrosion behaviour
Authors: Birdeanu Mihaela , Fagadar-Cosma Gheorghe , Sebarchievici Iuliana , Birdeanu Aurel-Valentin , Taranu Bogdan , Taranu Ioan , Fagadar-Cosma Eugenia
Published: September 2015

Zn(Ta1-xNbx)2O6 pseudo-binary oxide nanocrystalline materials (where x = 1;
0.5; 0.1; 0.05 and 0) were obtained through the solid-state method and
characterized by X-ray diffraction, Fourier Transform Infrared Spectroscopy
and Ultraviolet-visible spectroscopy. In addition, their morphology and
topography have been determined by field emission-scanning electron
microscopy (SEM) and atomic force microscopy (AFM). There is a significant
dependence between the rugosity and the uniformity of crystals. The evenly
crystals organized in multilayers have the lowest value of rugosity and the
non uniform fractal type architectures have the highest value of rugosity.
The compounds? anti-corrosion features were evaluated after deposition on
carbon steel (OL) in 0.1 M Na2SO4 media by open circuit potential measurement
and potentiodynamic polarization technique with Tafel representation. The
inhibition efficiency of pseudo-binary oxides deposited on carbon steel
electrode was in the range 42.3-52.7 % promising for their further multiple
layer deposition with porphyrins in order to improve anticorrosion
properties. Due to the high band gap (3.80 - 4.30 eV) provided by increasing
the tantalum content, four of these pseudo-binary oxides might find
applications in photovoltaic cells.
Synchronous Hepatoblastoma, Neuroblastoma, and Cutaneous Capillary Hemangiomas: A Case Report
Authors: Ozawa Michael G. , Cooney Tabitha , Rangaswami Arun , Hazard Florette K.
Published: September 2015

Multiple synchronous tumors presenting in infancy raise concern for inherited or sporadic cancer predisposition syndromes, which include Beckwith-Wiedemann syndrome, familial adenomatous polyposis syndrome, and Li-Fraumeni syndrome. We report a case of a 7-month-old previously healthy male born following an in vitro fertilization-assisted twin pregnancy who presented with new-onset refractory shock, severe acidosis, and rapid decline over several hours. An autopsy revealed a ruptured liver involved by hepatoblastoma, an adrenal gland involved by neuroblastoma, and multiple cutaneous capillary hemangiomas. Standard genetic testing demonstrated that both twins were Gaucher disease (GD) carriers without evidence of other known cancer predisposition syndromes. This report describes a unique association of multiple synchronous tumors, which underscores the utility and importance of the pediatric autopsy. Moreover, given that the reported child was a GD carrier, the possibility the tumors were the result of a GD-mediated cancer-associated phenotype or an unrecognized sporadic clinical syndrome remains an unanswered, but intriguing, question worthy of further investigation.
Placental and Clinical Characteristics of Term Small-for-Gestational-Age Neonates: A Case-Control Study
Authors: Chisholm Karen M. , Folkins Ann K.
Published: September 2015

Numerous conditions, including placental vascular compromise, can lead to small-for-gestational-age (SGA) infants. As few studies have investigated primarily term placentas from SGA infants, we compared placentas from 67 SGA infants to placentas from 67 infants with appropriate weights for gestational age (AGA) in this population, matched for gestational age and gender. Placental histology was reviewed and electronic records were queried for maternal and fetal birth data, infant morbidities, and infant follow-up weights. Comparison of these 2 cohorts showed that placentas from SGA infants were more likely to have smaller weights and thinner umbilical cords than those from AGA infants. SGA placentas had a significant increase in another uteroplacental malperfusion feature: single and multiple infarctions. Rates of preeclampsia, infant cardiac anomalies, and infant genetic abnormalities were not statistically different between groups. Fetal and maternal inflammatory responses, nongestational diabetes, and gestational hypertension were more common in the controls, but these are common indications for placental examination. No statistical differences were present for decidual vasculopathy, chronic villitis, intervillous thrombi, or meconium. More SGA neonates had hypoglycemia compared to their AGA counterparts. SGA infants tended to have decreased weights up to 7 months of age; however, the low number of infants with follow-up limited the statistical significance. This study confirms that small placental size and select features of uteroplacental malperfusion are more common in SGA versus AGA term placentas. The lack of other significant differences may be due to the inclusion of only term infants, with more severe pathology leading to preterm delivery.
Molecular Characterization of Sporadic Pediatric Thyroid Carcinoma with the DNA/RNA ThyroSeq v2 Next-Generation Sequencing Assay
Authors: Picarsic Jennifer L. , Buryk Melissa A. , Ozolek John , Ranganathan Sarangarajan , Monaco Sara E. , Simons Jeffrey P. , Witchel Selma F. , Gurtunca Nursen , Joyce Judith , Zhong Shan , Nikiforova Marina N. , Nikiforov Yuri E.
Published: September 2015

The aim of this study was to test the hypothesis that our 60-gene DNA/RNA ThyroSeq v2 next-generation sequence (NGS) assay would identify additional genetic markers, including gene fusions in sporadic pediatric differentiated thyroid carcinomas (DTC) that had no known molecular alterations. Sporadic pediatric DTCs with informative molecular testing ( n = 18) were studied. We previously tested 15 cases by our standard 7-gene ( BRAF, NRAS, HRAS, KRAS, RET/PTC1, RET/PTC3, PAX8/PPARg) mutation panel. Three cases were not tested previously. The standard 7-gene panel identified molecular alterations in 9 of 15 tumors (60%). Cases analyzed by ThyroSeq v2 NGS included the six previously negative cases by the standard 7-gene panel and three cases not previously tested. The NGS assay revealed new gene fusions in four of six previously negative cases (67%). These gene fusions included ETV6/NTRK3 ( n = 3) and TPR/NTRK1 ( n = 1). A point mutation ( BRAF-V600E) was detected in one of three untested cases. While standard testing could identify only molecular alterations in 60% of cases, with the addition of the ThyroSeq v2 NGS, this increased to 87% ( n = 13/15). Some cases with chromosomal rearrangements, including ETV6/NTRK3, appear to be associated with an aggressive histopathologic phenotype, but had no documented history of radiation exposure. Additional work is needed to investigate if pediatric DTCs could benefit from a reclassification based on molecular subtypes, which may better reflect their underlying biologic potential. Our data support the use of broad gene panels for the molecular diagnostics of pediatric thyroid nodules to aid future classification, treatment, and clinical management recommendations.
Effects of Pavement Surface Roughness and Congestion on Expected Freeway Traffic Energy Consumption
Authors: Ghosh Laura E. , Lu Liqun , Ozer Hasan , Ouyang Yanfeng , Al-Qadi Imad L.
Published: September 2015

In life-cycle assessments of roadway infrastructure projects, the significant amount of energy consumed during the use phase has been largely ignored when decisions related to roadway construction and rehabilitation have been evaluated. Traffic congestion, pavement types, and surface roughness conditions affect energy consumption throughout the use phase. This study developed an integrated modeling framework that accounted for the effects of pavement roughness degradation on estimated energy consumption for freeways and other restricted access highways, considering vehicle types and traffic growth, as well as congestion patterns. The framework was achieved through three interdependent modules: Module 1 estimated vehicle specific power (VSP) by relating the International Roughness Index (IRI) of pavements to coefficients used in the Environmental Protection Agency's motor vehicle emission simulator, Module 2 used the state-of-the-art cell transmission model to predict traffic evolution and congestion on the freeway and determined the total vehicle miles traveled at a spectrum of speed ranges, and Module 3 estimated energy consumption from an IRI profile, VSP coefficients, and traffic speed–miles profile. A case study confirmed that IRI and congestion had significant impacts on estimates of energy consumption during the use phase. The study showed that ignoring IRI variation or traffic congestion could lead to underestimations in VSP by up to 2.5% and energy consumption by approximately 6%.
Influence of Fuel Injection System and Engine-Timing Adjustments on Regulated Emissions from Four Biodiesel Fuels
Authors: Depcik Christopher , Jachuck Joshua , Jantz Dylan , Kiani Farshid , Mangus Michael , Mattson Jonathan , Peltier Edward , Stagg-Williams Susan M.
Published: September 2015

The use of biofuels for transportation has grown substantially in the past decade in response to federal mandates and increased concern about the use of petroleum fuels. As biofuels become more common, it is imperative to assess their influence on mobile source emissions of regulated and hazardous pollutants. This assessment cannot be done without first obtaining a basic understanding of how biofuels affect the relationship between fuel properties, engine design, and combustion conditions. Combustion studies were conducted on biodiesel fuels from four feedstocks (palm oil, soybean oil, canola oil, and coconut oil) with two injection systems, mechanical and electronic. For the electronic system, fuel injection timing was adjusted to compensate for physical changes caused by different fuels. The emissions of nitrogen oxides (NOx) and partial combustion products were compared across both engine injection systems. The analysis showed differences in NOx emissions based on hydrocarbon chain length and degree of fuel unsaturation, with little to no NOx increase compared with ultra-low sulfur diesel fuel for most conditions. Adjusting the fuel injection timing provided some improvement in biodiesel emissions for NOx and particulate matter, particularly at lower engine loads. The results indicated that the introduction of biodiesel and biodiesel blends could have widely dissimilar effects in different types of vehicle fleets, depending on typical engine design, age, and the feedstock used for biofuel production.
Model System to Evaluate Impacts of Vehicle Purchase Tax and Fuel Tax on Household Greenhouse Gas Emissions
Authors: Liu Yan , Cirillo Cinzia
Published: September 2015

This paper proposes a model system to forecast household-level greenhouse gas emissions (GHGEs) from private transportation and evaluate the effects of car-related taxation schemes on vehicle emissions. The system contains four submodels that specifically capture households' vehicle and vintage, quantity, usage, and GHGE rates (GHGERs) by vehicle type. The vehicle GHGERs are calculated with the Motor Vehicle Emission Simulator 2014, which is authorized by the Environmental Protection Agency. The whole model system was applied to the Washington, D.C., metropolitan area. The 2009 National Household Travel Survey was employed with supplementary data from Consumer Reports, American Fact Finder, and 2009 state motor vehicle registrations. The study proposed two tax schemes, vehicle purchase tax and fuel tax, and predicted their effects on reductions in vehicle GHGEs. The average annual GHGE per vehicle was 5.86 tons of carbon dioxide–equivalent gas without the proposed taxes. After two taxation policies were implemented, the results showed the following: (a) the impacts on reducing GHGEs from fuel taxes were higher than those from purchase taxes, (b) purchase taxes reduced GHGEs mainly by decreasing the number of cars of households with more vehicles, and (c) fuel taxes successfully reduced GHGEs by decreasing the use of cars by households with fewer vehicles. The model system can be extended to other zones, counties, states, and nations.
Measurement and Evaluation of Real-World Speed and Acceleration Activity Envelopes for Light-Duty Vehicles
Authors: Liu Bin , Frey H. Christopher
Published: September 2015

Accurate estimation of vehicle activity is critically important for the accurate estimation of emissions. To provide a benchmark for estimation of vehicle speed trajectories such as those from traffic simulation models, this paper demonstrates a method for quantifying light-duty vehicle activity envelopes based on real-world activity data for 100 light-duty vehicles, including conventional passenger cars, passenger trucks, and hybrid electric vehicles. The vehicle activity envelope was quanti-fied in the 95% frequency range of acceleration for each of 15 speed bins with intervals of 5 mph and a speed bin for greater than 75 mph. Potential factors affecting the activity envelope were evaluated; these factors included vehicle type, transmission type, road grade, engine displacement, engine horsepower, curb weight, and ratio of horsepower to curb weight. The activity envelope was wider for speeds ranging from 5 to 20 mph and narrowed as speed increased. The latter was consistent with a constraint on maximum achievable engine power demand. The envelope was weakly sensitive to factors such as type of vehicle, type of transmission, road grade, and engine horsepower. The effect of road grade on cycle average emissions rates was evaluated for selected real-word cycles. The measured activity envelope was compared with those of dynamometer driving cycles, such as the federal test procedure, highway fuel economy test, SC03, and US06 cycles. The effect of intervehicle variability on the activity envelope was minor; this factor implied that the envelope could be quantified based on a smaller vehicle sample than used for this study.
Implementing Mobility as a Service
Authors: Sochor Jana , Strömberg Helena , Karlsson I. C. MariAnne
Published: September 2015

This paper presents insights from a six-month field operational test (FOT) in Gothenburg, Sweden, during which 195 participants tested the UbiGo mobility service for everyday travel. The service integrated both public and private solutions into a new type of collective transport and thereby contributed to Swedish societal goals of a reduction of private car use and ownership. A triangulation approach to data sources and collection methods was adopted to identify matches and mismatches between the expectations and experiences of three stakeholder groups: users (FOT participants–customers), commercial actors (mobility broker and service providers), and society. Identified matches included the concept of a transportation smorgasbord, reduced private car ownership, and increased pretrip planning. Identified mismatches related to the greater than expected reduction in car use, the respective business models of the mobility broker and service providers, back-office administration, and the smartphone platform. Gaps included the infeasibility of some trips and the need for more carsharing sites. The FOT was successful, with 93% of participants satisfied with their travel and 97% wanting to continue using UbiGo. However, before a commercially viable mobility service can be created, the mismatches and gaps need to be resolved or at least deliberated. The conclusion is that to create integrated solutions, truly collective transport must involve close cooperation between public and private actors and the consideration of at least the three, sometimes conflicting, stakeholder perspectives. Furthermore, new business models are needed to address the challenges associated with future integrated urban mobility solutions.
Integrated Relocation Model for Free-Floating Carsharing Systems
Authors: Weikl Simone , Bogenberger Klaus
Published: September 2015

This paper presents an integrated relocation model for free-floating car-sharing (FFCS) systems. A historical data analysis conducted monthly generates demand indicators. A zone categorization identifies zones with a historical vehicle shortage or surplus and enables the estimation of the optimal vehicle distribution for the target time period. Given the current vehicle positions, the model identifies vehicle imbalances. Five macroscopic and microscopic steps using optimization and rule-based methods recommend relocations and service trips on an individual vehicle level. This process results in detailed staff operation plans. To assess the impact of relocations on the system's operation, the model was applied to an FFCS system in Munich, Germany. Three real-world field tests conducted at stages of the model's development exhibited different degrees of automation. The evaluation showed promising results. All tests had positive impacts on the main measures of success. The earnings per vehicle were increased by up to 18%. The mean idle time per trip end of all vehicles in the feet was decreased by up to 18%. The difference in idle times between the relocated vehicles and neighboring vehicles that were not relocated was decreased by up to 31%. Most important, the profit of the operator was between 4.7% and 5.8% higher than without relocations. The automation of the whole model in the last field test led to slightly lower but still very positive impacts while facilitating the whole relocation process for the operator.
What about Free-Floating Carsharing?
Authors: Wielinski Grzegorz , Trépanier Martin , Morency Catherine
Published: September 2015

In recent years, carsharing has become a practical, ecological, and economical alternative to private car ownership around the world. Traditional carsharing is station-based, but new types of shared services have appeared recently. One of those is free-floating carsharing. It is more flexible, but what is its impact on user behavior? This paper aims to characterize the use of the free-floating carsharing service in central Montreal, Canada. Use of the traditional, station-based service and the new service was compared. Because some people were members of both services, it was possible to examine the specific contribution of each service to meeting travel needs. The impact of the introduction of this new transportation alternative was also examined. The results showed that compared with traditional carsharing, more women were members of the free-floating service and the trip distances and durations were much shorter. Shopping was the most important activity, and there was a concentration of trip ends near the central business district in the midday period. When asked what mode users would have used in the absence of the free-floating service, people mentioned public transit, taxis, and walking; the popularity of these alternatives varied, probably in relation to seasonal changes. Further studies are required to measure the environmental impact of this new transportation mode.