bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Phospholipid Fatty Acid Content Is Related to Disease Activity in Ankylosing Spondylitis
Authors: SUNDSTRÖM BJÖRN , JOHANSSON GUNNAR , KOKKONEN HEIDI , CEDERHOLM TOMMY , WÅLLBERG-JONSSON SOLVEIG
Published: December 2011

Objective.

To investigate fatty acid composition in the diet, plasma phospholipids, and adipose tissue in a cohort of patients with ankylosing spondylitis (AS), and to determine their correlations to disease activity and blood lipids in a cross-sectional study.

Methods.

Diet was assessed using a food frequency questionnaire in 66 patients with AS. Polyunsaturated fatty acids in plasma phospholipids and gluteal adipose tissue were measured using gas chromatography. Disease status was quantified using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein, and proinflammatory cytokines.

Results.

Diet did not correlate with disease activity assessed by the BASDAI, but there were negative correlations between the dietary intake of long-chain omega-3 fatty acids and ESR (rs= –0.27, p < 0.05). The plasma phospholipid content of arachidonic acid correlated significantly with the BASDAI score (rs= 0.39, p < 0.01). There were correlations between the intake of long-chain omega-3 fatty acids and high-density lipoproteins and serum triglycerides (rs= 0.26 and rs= –0.25, respectively, p < 0.05).

Conclusion.

There was a positive correlation between levels of arachidonic acid in plasma phospholipids and disease activity assessed by BASDAI in patients with AS. A Western diet does not appear to influence this correlation, but seems to affect blood lipids involved in atherogenic processes.
Mortality and Incidence of Malignancy in Korean Patients with Rheumatoid Arthritis
Authors: KIM YUN JUNG , SHIM JEE-SEON , CHOI CHAN-BUM , BAE SANG-CHEOL
Published: December 2011

Objective.

To determine the standardized mortality ratio (SMR) and standardized incidence ratio (SIR) for malignancy in Korean patients with rheumatoid arthritis (RA).

Methods.

We enrolled 1534 patients with RA who fulfilled the American College of Rheumatology criteria, from October 2001 to December 2007. Baseline assessment included sociodemographic variables, laboratory findings including rheumatoid factor, anticitrullinated protein antibody, functional class, radiological stage, medication, and the Korean version of the Health Assessment Questionnaire. We used the national mortality rate from 2001 to 2007 from the Korean National Statistical Office (KNSO) and the incidence rate from the Korean Central Cancer Registry (KCCR) from 2001 to 2007 as comparison data for estimates of SMR and SIR. Confidence intervals were calculated based on the Poisson distribution.

Results.

There were 57 deaths in 6683 person-years of followup. The number of expected deaths (derived from the KNSO) was 42.33 and the SMR for patients with RA was 1.35 (95% CI 1.02–1.74). The main causes of death were malignancy, cardiovascular disease, and respiratory disease. In the cause-specific SMR, deaths from respiratory disease, especially from interstitial lung disease (ILD) and pneumonia, were significantly higher than expected: 4.66 (95% CI 2.13–8.85) for all respiratory disease, 18.18 (95% CI 2.20–65.64) for ILD, and 10.26 (95% CI 2.79–26.26) for pneumonia. Thirty malignancies had occurred in 1501 patients. The number of expected malignancies derived from the KCCR was 34.91, yielding a SIR for cancer of 0.86 (95% CI 0.58–1.23).

Conclusion.

Our study demonstrates that the SMR was slightly higher in patients with RA, but the incidence rates of malignancies were not significantly different from the general population. But deaths from respiratory diseases were significantly higher.
Risk Factors Associated with Relapse in Japanese Patients with Microscopic Polyangiitis
Authors: WADA TAKASHI , HARA AKINORI , ARIMURA YOSHIHIRO , SADA KEN-EI , MAKINO HIROFUMI ,   Research Group of Intractable Vasculitis, Ministry of Health, Labor, and Welfare of Japan
Published: December 2011

Objective.

We retrospectively studied the risk factors associated with relapse during remission maintenance therapy for myeloperoxidase-antineutrophil cytoplasmic autoantibody (MPO-ANCA)-positive microscopic polyangiitis (MPA).

Methods.

Sixty-two patients diagnosed with MPA according to the European Medicines Agency classification algorithm during a 2-year period from January 1, 2005, to December 31, 2006, and who achieved remission after the first remission-induction therapy, were examined (registration no. UMIN000001785).

Results.

The patient group comprised 25 men and 37 women aged 70.0 ± 8.9 years. The mean observation period was 30.2 ± 15.9 months. The rate of relapse was 24.2% (15/62), and mean interval between remission and relapse was 16.9 ± 13.5 months. During maintenance therapy following remission, the risk of relapse increased when the reduction rate of prednisolone increased above 0.8 mg/month (OR 12.6, 95% CI 2.2–97.9). Proteinuria at the start of maintenance therapy (regression coefficient 1.991 ± 0.758, p < 0.05) and the change in red blood cell counts in urine during the period from the start of maintenance therapy to the final observation (regression coefficient 0.126 ± 0.040, p < 0.01) were identified as risk factors influencing the vasculitis damage index.

Conclusion.

In Japan, relapse of MPO-ANCA-positive MPA may be associated with the reduction rate of oral prednisolone administration during maintenance therapy.
Relation of Hand Enthesophytes with Knee Enthesopathy: Is Osteoarthritis Related to a Systemic Enthesopathy?
Authors: GIBSON NADIA , GUERMAZI ALI , CLANCY MARGARET , NIU JINGBO , GRAYSON PETER , ALIABADI PIRAN , ROEMER FRANK , FELSON DAVID T.
Published: December 2011

Objective.

Enthesopathy has been reported as a feature of osteoarthritis (OA) in the distal interphalangeal (DIP) joints. We previously reported that central bone marrow lesions (BML) on magnetic resonance imaging (MRI) scans are associated with OA. In this study, we evaluated whether hand and knee enthesopathy were related.

Methods.

We studied knee and hand radiographs of subjects from the Framingham Osteoarthritis Study. Subjects seen in 2002–2005 had bilateral posteroanterior hand radiographs, weight-bearing knee radiographs, and knee MRI scans. Hand radiographs were read for enthesophytes at the juxtaarticular nonsynovial areas of metacarpophalangeal (MCP), proximal interphalangeal (PIP), and DIP joints, and midshafts of the phalanges. We selected 100 cases of knees with central BML and 100 matched controls. Conditional logistic regression was used to assess associations.

Results.

Subjects with enthesophytes of at least 1 score ≥ 2 at DIP, PIP, and/or MCP were not more likely to have central knee BML (OR 0.49, 95% CI 0.17–1.40) than those without enthesophytes. Similarly, having at least 1 score ≥ 2 on the shafts was not significantly associated with having a central knee BML (OR 0.59, 95% CI 0.23–1.51). Adjustment for the presence of diabetes mellitus did not affect these results, but there was an increased prevalence of diabetes in those with hand enthesophytes (OR 3.09, 95% 1.29–7.40, enthesophyte score ≥ 2).

Conclusion.

We found no increase in the prevalence of hand enthesophytes among persons with central knee BML on their knee MRI scans. This provides evidence against a systemic enthesopathic disorder in association with knee OA.
Nicotinamide Adenine Dinucleotide Tetrazolium Reductase Identifies Microvasculature Activation in Muscle from Adult Patients with Dermatomyositis
Authors: CHARLES-SCHOEMAN CHRISTINA , VERITY M. ANTHONY
Published: December 2011

Objective.

Previous work has suggested involvement of the muscle microvasculature in the pathogenesis of dermatomyositis (DM). Our study evaluates whether standard histochemical reactions can identify microvascular changes in muscle biopsies from patients with DM compared to myopathic and nonmyopathic controls.

Methods.

Muscle biopsies were obtained from 111 patients, including 45 patients with DM. Microvascular quantitation was performed on transversely oriented 1-μm toluidine blue-stained plastic sections. Histoenzymatic procedures included alkaline phosphatase (AP), nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR), succinate dehydrogenase (SDH), cytochrome C oxidase (COX), and myosin ATPase reactions.

Results.

Capillary density was significantly lower in DM muscle biopsies compared to biopsies from patients with noninflammatory myopathies (NIM; n = 26) and healthy control muscle (n = 27; mean ± SD: 252 ± 114 vs 402 ± 56 and 325 ± 109 capillaries/mm2, respectively; p values < 0.05). In contrast, a marked increase in the number of capillaries staining with NADH-TR was noted in DM compared to other idiopathic inflammatory myopathies (IIM; n = 13), NIM, and controls (49.8 ± 50.7 vs 8.0 ± 7.1, 6.7 ± 7.2, and 3.6 ± 2.8 capillaries/mm2; p < 0.05 compared to DM). DM capillaries also demonstrated mildly increased staining with AP compared to controls; however, no increased SDH or COX reactivity was observed.

Conclusion.

DM muscle capillaries are highly reactive with NADH-TR compared to myopathic and nonmyopathic controls. The lack of staining of DM capillaries with mitochondrial SDH and COX reactions suggests that NADH-TR reactivity may be secondary to activation of the microvascular endoplasmic reticulum, rather than mitochondrial hyperplasia.
Gestão dos Riscos Urbanos em São Paulo: as áreas contaminadas
Authors: Ramires Jane Zilda dos Santos , Ribeiro Wagner Costa
Published: December 2011

Este trabalho apresenta a problemática relacionada às áreas contaminadas. Esta questão ambiental passou a ser de conhecimento público a partir da década de 1980, por meio do processo de desconcentração industrial verificado na mais densa área urbana do Brasil. Na primeira parte, será analisado como este fenômeno, somado a mudança do uso do solo urbano resultou no surgimento das áreas de risco, uma vez que as áreas contaminadas estão sendo utilizadas ou receberam novos usos, como residenciais ou serviços, sem que fossem realizados estudos ambientais específicos com posterior recuperação e/ou remediação. Com o objetivo de auxiliar no entendimento, abrangência e magnitude da questão, será apresentado um mapeamento, por distrito, das indústrias existentes na mancha urbana paulista; o qual expressa à distribuição dos riscos e perigos construídos ao longo de décadas no território do município de São Paulo. Na segunda parte, aborda-se como o poder público trata o tema; suas dificuldades e acertos. Por fim, estão as conclusões, que indicam que a aplicação efetiva da legislação específica para a gestão de áreas contaminadas, com a exigência da realização dos estudos ambientais, além da disponibilização das informações à sociedade, com aumento da visibilidade do problema, pode ser o caminho para solucioná-los, ainda que hoje a participação popular, incipiente nesse caso, seja fundamental nesse processo.
Knowledge Sharing Adoption Model Based on Artificial Neural Networks
Authors: Folorunso Olusegun O. , Vincent Rebecca Opeoluwa , Ogunde Adewale Akintayo , Agboola Benjamin
Published: December 2011

Knowledge Sharing Adoption Model called (KSAM) was developed in this paper using Artificial Neural Networks (ANN). It investigated students’ Perceived Usefulness and Benefits (PUB) of Knowledge Sharing among students of higher learning in Nigeria. The study was based on the definition as well as on the constucts related to technology acceptance model (TAM). A survey was conducted using structured questionnaire administered among students and analysed with SPSS statistical tool; the results were evaluated using ANN. The KSAM includes six constucts that include Perceived Ease Of Sharing (PEOS), Perceived Usefulness and Benefits (PUB), Perceived Barriers for Sharing (PBS), External Cues to Share (ECS), Attitude Towards Sharing (ATT), and Behavioral Intention to Share (BIS). The result showed that Students’ PUB must be raised in order to effectively increase the adoption of Knowledge Sharing in this domain. The paper also identified a myriad of limitations in knowledge sharing and discovered that the utilization of KSAM using ANN is feasible. Findings from this study may form the bedrock on which further studies can be built.
Towards E-Society Policy Interoperability for Social Web Networks
Authors: Iannella Renato
Published: December 2011

The move toward Policy-Oriented Web is destined to provide support for policy expression and management in the core web layers. One of the most promising areas that can drive this new technology adoption is e-Society communities. With so much user-generated content being shared by these social networks, there is the real danger that the implicit sharing rules that communities have developed over time will be lost in translation in the new digital communities. This will lead to a corresponding loss in confidence in e-Society sites. The Policy-Oriented Web attempts to turn the implicit into the explicit with a common framework for policy language interoperability and awareness. This paper reports on the policy driving factors from the Social Networks experiences using real-world use cases and scenarios. In particular, the key functions of policy-awareness—for privacy, rights, and identity—will be the driving force that enables the e-Society to appreciate new interoperable policy regimes.
Diffusion of E-Learning Practice in an Educational Institution
Authors: Thomas Keith , Lam Paul , Ho Annisa
Published: December 2011

Successful knowledge transfer or diffusion of e-learning practice goes beyond precursor incentives and anticipated rewards for the individual lecturer. It also involves wider enabling of learning attributes and cultural capabilities in an organization. This paper examines how some of these attributes and capabilities play out in an educational institution in the context of web-enabled technology. An organizational-learning model is used to examine diffusion of practices after initial design and development. This paper is based on a case study of eight course-level e-learning projects in a university based in Hong Kong. The study illustrates a number of issues and challenges for the wider uptake of the initial idea from the individual course to the programme and wider institution.
A Method of 3-D Microstructure Reconstruction in the Simulation Model of Cement Hydration
Authors: Zhang Dongliang
Published: December 2011

An accurate and reliable computer simulation system can help practical experiments greatly. In a cement hydration simulation system, the basic requirement is to reconstruct the 3-D microstructure of the cement particles in the initial state while mixed with water. A 2-D SEM/X-ray image is certainly achievable; however, it is not easy to obtain parallel images due to the small scale of the cement particles. In this regard, a method is proposed to reconstruct the 3-D structure from a single microstructure image. In this method, micro-particles are regenerated in a growing trees mode, which by modifying the generating probability of the leaves, the irregularity and the surface fraction of particles can be controlled. This method can fulfill the requirement for the parameters of the 3-D image while assuring that the 2-D image is in full accord.
Using Web 2.0 to Reconceptualize E-Government
Authors: Sadeghi Leila , Ressler Steve , Krzmarzick Andrew
Published: December 2011

This chapter examines the growing literature on e-government and Web 2.0 with particular attention to online collaborative platforms, such as GovLoop, that complement government. The authors present a thorough background to the topic of Web 2.0 in e-government and present numerous examples of how these technologies are used across government both in the U.S. and globally. This chapter explores two main areas: first, how Web 2.0 and social media are being used as a vehicle to enhance e-government, and second, to present a case study of GovLoop, which is a collaborative social media platform designed to complement the work of government. GovLoop provides those working within and external to government—citizens, government employees, academics, non-profit professionals and contractors—with the ability to share information and collaborate on issues of public benefit. The chapter presents a starting point for future research on how Web 2.0 is changing the very nature of e-government and service delivery, and how governments are in a unique position to utilize these tools to expand collaboration and openness with their communities.
Web 2.0
Authors: Isaías Pedro , Pífano Sara , Miranda Paula
Published: December 2011

Democracy shares many of its core principles with Web 2.0: it is participatory, interactive, individual-centered, host to and tolerant of multiple voices and opinions. They even have some common polemics: wisdom of the crowds vs. ignorance of the crowds; and the fact that everyone voicing an opinion may constitute both noise and debate. The emergence of the term e-Democracy 2.0 results from an alliance between Web 2.0 and democracy. This chapter intends to demonstrate that Web 2.0 has the potential to improve democracy. For this purpose, it begins by providing an overview of the core benefits and challenges of e-Democracy 2.0, then focuses on the importance of social technology for citizen participation. More specifically, this chapter conducts a content analysis to assess the role that Facebook plays in terms of encouraging and facilitating citizen participation.
The Paradox of the Interactive Web in the U.S. Public Sector
Authors: Mergel Ines A. , Schweik Charles M.
Published: December 2011

Web 2.0 technologies—what we prefer to call the “Interactive Web”—have become frequently used tools in the public sector. These tools include social networking applications such as Twitter, Facebook, Wikis, or RSS feeds. Public sector agencies are using blogs to communicate information on public hearings, wikis to coordinate work or share expertise and intelligence information, and social networking sites to communicate with citizens. These kinds of applications create a public sector paradox. On the one hand, they have the potential to create opportunities related to key public sector issues of transparency, accountability, communication and collaboration, and to promote deeper levels of civic engagement. On the other hand, information flow within government, across government agencies, and between government and the public is often highly restricted through regulations and specific reporting structures, and therefore usually delayed through the filter of bureaucratic constraints. The authors provide an overview of drivers encouraging the adoption of Interactive Web applications, but also transformative organizational, technological, and informational challenges ahead that might lead to resistance to that change.
Dependency of Transport Functions on IEEE802.11 and IEEE802.15.4 MAC/PHY Layer Protocols for WSN
Authors: Sharif Atif , Potdar Vidyasagar , Rathnayaka A. J. D.
Published: December 2011

In WSN transport, layer protocol plays a significant role in maintaining the node’s energy budget. To find out the dependency of Transport layer on MAC/PHY layer, the authors have extensively tested various transport protocols using IEEE 802.11, IEEE 802.15.4 MAC/PHY protocols for WSN. For IEEE802.11 and IEEE802.15.4 with RTS/CTS ON the TCP variants has shown >80% packet delivery ratio and 5-20% packet loss, while for UDP it is around >63% and 19.54-35.18% respectively. On average 1-3% additional energy is consumed for packet retransmissions in IEEE 802.11 with RTS/CTS OFF whereas significant energy efficiency is observed in IEEE802.15.4 case. For IEEE 802.11 with RTS/CTS ON high throughput, low packet drop rate and increased E-2-E delay is observed, while for IEEE 802.15.4 improved power efficiency and jitter behavior is observed. This has led the foundation for the future development of the cross-layered energy efficient transport protocol for WSN.
Technology and the Substitute Teacher
Authors: Bruner Chelsea
Published: December 2011

A great deal goes into ensuring a smooth-running classroom when a teacher is absent. Mrs. Truman, a substitute teacher, highly recommends pre-regulated set-up and training in technology for substitute teachers.
Future Trends in SCM
Authors: Farahani Reza Zanjirani , Dadgostari Faraz , Tirdad Ali
Published: December 2011

The field of supply chain management (SCM) has experienced radical changes in its short life period. Originating from 1980 and 1990s management trends and techniques of operations management, passing process oriented and system oriented approaches in the 1990s, and now attracting the attention to behavioral approaches have all caused SCM to be largely vertiginous. So dealing with its future requires a more accurate method than common predicator fashions. Therefore, the chapter first considers SCM as a body of knowledge in which evolution is based on its theoretical foundation, and therefore, prevalent research paradigm(s), research methodological base(s) used by developers, and also real world challenges that motivate it. Consequently, the authors review current status of SCM from standpoint of the discipline’s theory, its conceptualization process, and most used research methods and approaches. Then the authors will be able to use its implications to adopt an appropriate model of philosophy of knowledge for scientific change and knowledge growth of SCM. This can be used as a guide to the future of supply chain management.
CRM, SRM and Marketing in Supply Chain
Authors: Kamran Mehdi Abdollahi
Published: December 2011

The first goal of this chapter is to disclose different aspects of this customer-focused strategy, such as CRM definitions, goals, perspectives, and SCM and CRM integration features. But due to the continual needs of cutting costs, organizations realized the necessity of long term buyer-seller relationships, and they were forced to improve their supply chain and leverage their supply base. The key solution to this necessity is Supplier Relationship Management (SRM). After describing various aspects of CRM, therefore in the second part the different characteristics of SRM and the way going from CRM to SRM is being discussed.
Paradigms of Supply Chain Management
Authors: Heydari Jafar
Published: December 2011

Supply chain management is a naturally difficult task due to participation of various economically independent companies. In turn, strategy planning and management processes in supply chain are more complicated than a single business. In the process of strategy formulation for a supply chain, it is necessary to consider benefit and abilities of all members. In this chapter, some models for supply chain strategy formulation are discussed, and the most applicable management paradigms of supply chain are investigated. In addition, initiatives, attributes, and appropriate conditions for implementing each paradigm are investigated. Hence, the purpose of this chapter is to give a viewpoint regarding philosophies and concept of supply chain management along with introducing and analyzing some paradigms and practices of supply chain management including lean, agile, leagile, resilient, and green paradigms.
Quantitative Models in Supply Chain Management
Authors: Moradi Esmaeel , Arsalan Mohammad Reza Ghezel , Sadigh Ali Naimi , Ghalb Hamed Fallah Roshan
Published: December 2011

Moreover, a wide review given by Terzi and Cavalieri (2004) on more than 80 papers about simulation in the supply chain context is used in this chapter. The main goal of this review is to determine which objectives simulation is used to solve the problems, which simulation models are more appropriate and useful for supporting the decision making in the supply chain.
Use of the ISO 19906 Arctic Structures Standard
Authors: McKenna Richard , Spring Walt , Thomas Graham
Published: December 2011

The new ISO 19906 Arctic Offshore Structures standard contains provisions relating to a number of different types of offshore oil and gas structures in the Arctic and in other cold regions. Its provisions supplement those of ISO 19902 (steel offshore structures), ISO 19903 (concrete offshore structures), ISO 19904–1 (floating offshore structures) and other standards in the ISO 19900 series.

This paper focuses on important arctic provisions and on how the standard can be used in conjunction with the other ISO offshore structures standards. Issues dealt with include features of arctic and cold regions; when the standard should be used; types of ice actions and how they should be applied; ice actions in the context of other physical environmental actions; manmade islands; subsea installations; ice data collection; monitoring; interpretation and analysis; ice management systems and operational aspects of arctic structures; and low temperature materials and equipment.

Introduction

Background

Many of the structure design concepts used in arctic regions are similar to those in other areas and the same design principles apply. Nevertheless, the arctic environment poses a number of additional challenges due to marine icing on exposed surfaces, actions from sea ice and icebergs, structural vibrations as a result of ice actions, ice rubble encroachment, and brash ice build-up from icebreaker operations. In many cases, special operational procedures are required in harsh environmental conditions, which need to be factored into the designs. As a brittle solid, ice can exert considerable pressure over small contact areas, frequently exceeding average values over the loaded area. Local design requirements for ice are an integral part of the design process.

It is because of the above issues that the ISO 19906 standard [1] was developed and, because their implementation can differ from standard practice, is why the present paper reviews its application.

Terminology

The ISO series has some particularities in terms of terminology with respect to North American usage. The main one is the use of the term "action" instead of "load", which is a more general term that could imply a load, an acceleration or a displacement. The characteristic value of an action or parameter is one that has a specified annual probability of being exceeded, which is often interpreted as a return period value. The representative value of an action is a characteristic value or some other value that is used for design.
Considerations in the Application of Horizontal Directional Drilling to Pipeline Construction in the Arctic
Authors: Hair John D.
Published: December 2011

This paper assesses the current state of the art in horizontal directional drilling (HDD) for pipeline installation, reviews analytical methods associated with HDD pipeline design and installation, and presents concepts useful in the application of HDD techniques to pipeline construction in the arctic. The current state of the art is defined by a review of recent commercial applications of HDD to pipeline construction. Details on completed projects defining feasibility limits with respect to length and pipe diameter are presented. Restrictions with respect to subsurface conditions are examined. Theoretical limits on HDD pipeline installation are explored including a discussion of analytical methods available to calculate pulling loads associated with very long HDD Installations. The paper concludes with conceptual design examples of how HDD installation might be applied to obstacles presented by the arctic environment.

Current State of the Art in Pipeline Installation by Horizontal Directional Drilling

Three primary characteristics govern the feasibility of an HDD installation:subsurface conditions,pipe diameter, anddrilled length.

These three characteristics work in combination to limit what can be accomplished using existing HDD tools and techniques. Individual limits for each of these characteristics are discussed in the following paragraphs. It should be noted that, consistent with the objectives of this paper, this discussion is founded on commercial experience within the HDD Industry. The limits of directional drilling technology applied to drilling oil wells are not considered. While such tools and techniques may be applied to pipeline installation in the future, this paper discusses what is being utilized in the Pipeline Industry today.

Subsurface Conditions

The nature of the subsurface material through which the drilled path must pass is critical in determining the technical feasibility of an HDD pipeline installation. For a pipeline to be installed by HDD, either an open hole must be cut into the subsurface material so that installation of a pipeline by the pullback method is possible, or the properties of the subsurface material must be modified so that the soil behaves in a fluid manner allowing a pipeline to pass through it.

In the open hole condition a cylindrical hole is drilled through the subsurface. Drilling fluid flows to the surface in the annulus between the pipe and the wall of the hole. Drilled spoil is transported in the drilling fluid to the surface. This is generally applicable to rock and cohesive soils. It may also apply to some sandy or silty soils depending on the density of the material, the specific makeup of the coarse fraction, and the binding or structural capacity of the fine fraction.
Deepwater Drilling for Arctic Oil and Gas Resources Development: A Conceptual Study in the Beaufort Sea
Authors: Pilisi N. , Maes M. , Lewis D.B.
Published: December 2011

Surveys from the U.S.G.S, notably, have recently re-assessed the Arctic Circle and its deepest parts. Geology-based probabilistic analyses have found that significant oil and natural gas reserves, about 25% of the world's undiscovered resources, may be held in the deep Arctic Alaska (Bird, 2008; Houseknecht et al, 2010). Such studies are of the utmost interest for developed and emerging countries to help them meeting their growing demand in fossil fuels.

As of today, the bulk of investigations, projects and technical papers concerning drilling for arctic oil and natural gas resources, have concerned the onshore hydrocarbon accumulations or the near shore deposits (OTA, 1985; Bercha, 1984; Matskevitch 2006; MMS, 2008). However, when trying to access the arctic deeper waters, only a few structures are available today to drill in these polar environments. Offshore operations in the Arctic Ocean are essentially impacted by extremely cold weather temperatures yielding the presence of sea ice, icebergs, floes and long period of darkness. Nevertheless, deepwater drilling and production in the Arctic Ocean provides an attractive but extremely ambitious challenge for our industry. Because the U.S. Beaufort Sea has an average water depth of 3,240 ft, deepwater drilling provides an interesting and innovative option to develop enormous reserves of oil and natural gas.

This paper presents a conceptual study for exploratory and development wells in the harsh deepwater arctic environment of the U.S. Beaufort Sea by using a modified and winterized drill-ship with ice strengthened material or an icebreaker converted into a drilling vessel. In addition, ice management is discussed, considering a fleet of at least two icebreaker vessels to guaranty station keeping in first year sea ice and multi-year sea ice environments in order to conduct year-round operations with the floater. Also, the drilling and production phases will be discussed even in presence of icebergs or large ice floes. Finally, the paper briefly covers environmental regulations and economics. The main goal of this study is to help the oil and gas industry breaking the last barrier in exploration drilling and production by proposing structures and facilities that will enable to operate year-round in both open water and permanently ice-covered waters of the Arctic Circle.
Robust Robots for Arctic Exploration
Authors: Albiez J. , Hildebrand M. , Vogele T. , Joyeux S. , Kirchner F.
Published: December 2011

Under-ice exploration in the Arctic Ocean requires robust and reliable robotic tools. Autonomous underwater vehicles (AUVs) used in this environment have to be able to navigate reliably and with precision without the help of a dedicated infrastructure. They also have to be able to adapt and to react to changes in their environment. In this paper, new methods for AUV infrastructure-independent navigation and self-localization, as well as for an adaptive AUV control architecture are presented. These methods were developed at the DFKI within the framework of several nationally funded research projects. They were implemented on experimental AUVs and showed promising results in preliminary lab and field tests.

Introduction

Robots are needed to operate in areas that are too difficult or to too dangerous to access for humans. In remote areas like the deep sea and the Arctic Ocean, robots are invaluable helpers for scientific exploration, environmental monitoring, economic exploitation and other endeavours. As of today, robots have been used successfully by oceanographic research institutes, oil companies, and other stakeholders to access and explore the depths of the Arctic Ocean. However, the application of these robots - like the application of most professional service robots in harsh environments - is still hampered by a lack of autonomy, robustness and dependability. So far, robots can only be used in well-supervised short-term missions that require intensive support by an associated research vessel. A robust long-term deployment of autonomous robots in harsh environments, with a minimum of human supervision and support, is well beyond the current-state-of-the-art.

In this paper, we will present new methods that lead towards solutions for two key obstacles in the way of robust operation of robots in arctic exploration, namely the problem of reliable under water and under-ice self-localization and navigation, and the problem of adaptive mission control for AUVs. Both methods are the results of ongoing projects at the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI-RIC) in Bremen, Germany.

AUV Navigation and Self-Localization

Introduction

The ability to follow a given course without deviation and to determine it's own position without error is a challenge for any underwater vehicle, and in particular for AUVs that operate under ice. Nevertheless, depending on the mission profile as well as on the precision and type of self-localization required, there are numerous methods to determine the current position of an AUV.
Application of New Radar Sensor Technology for Enhanced Safety and Oil Spill Detection Through all Phases of Operations in the Arctic Environment
Authors: Isaksen Per-Arne , Havro Arnstein
Published: December 2011

Marine operations in the Arctic areas call for improved safety measures due to the rough weather conditions and the increased risk for operational interruptions and collision with icebergs/ice floes. In addition there is an imminent need to secure earliest possible warning of eventual oil spills and other substances which may cause harm to the vulnerable Arctic environment. By application of new and revolutionary radar sensor technology the industry can take a quantum leap in direction of safeguarding all these marine, drilling and production activities in the Arctic region and thereby avoid costly operational delays, accidents and limit oil spill recovery operations. The authority having jurisdiction of the exploration area will certainly demand and require documentation from the operator on behalf of the licensees to document that best possible technologies are taken into use to reduce risks as far as practically possible.

The standard navigation radars type approved according the IMO regulations MSC.192(79) and IEC 62388 / 60945 do not possess necessary skills to differentiate return signals from water and ice and hence the display will only present a partial truth of the ice conditions surrounding the vessel/rig/platform as the case may be. More advanced radar displays may to a certain extent compensate by further processing of the poor quality input data from the standard radar sensor. However, this cannot disregard the fact that improved radar sensor input data is the only measure that can provide the navigator with full and complete information of vessel surroundings in real time so that he can make best possible assessments and decisions as early as practically possible. The same applies to other important radar services like long distance real-time oil spill detection/warning/ monitoring, wave - and current measurement, warning of local weather phenomenon's and high waves, small and/or high speed targets (terror threats, other undesired presence interrupting operations), general marine traffic etc.

Radar picture processing has little real value unless supported by high quality input data. The Sea-Hawk technology represents the high end of radar sensor performance.

Radar is the only dynamical instrument which can provide a true real-time description of its 360° surroundings. All other instruments can only describe a partial truth or possibly a real-time description of a small sector in real-time.

The authors of this paper therefore recommends to the industry and all relevant authorities that a common specification is agreed upon for all activity in the Arctic environment in order for all parties affected to focus efforts in the same, and hopefully correct, direction in order both to safeguard human life, the vulnerable environment and reduce operational costs and consequential costs of any sort of accidents (damage or loss of vessels/rigs, authority induced operation/production stops, close downs etc.).
Experience of Air Bubbling System in Ice Navigation and Future Possibilities
Authors: Wilkman Goran
Published: December 2011

The air bubbling system for use in reducing ice resistance of icebreaking ships was introduced in late 1960ies. After extensive development and testing the system has been used in several vessels till early 1990ies. The idea of the system is to blow compressed air down in the bilge area of the vessel hull and the expanding air bubbles will rise to the free water surface reducing the friction between ice and the hull surface.

The system has been in use mainly in icebreakers, but also on tankers, dry cargo vessels as well as ferries. The size of the vessels with air bubbling system varies between a small coastal ferry to cargo ships of over 20000 tonnes.

The benefits of the system are not only to reduce ice resistance, but also for instance to reduce the risk of the vessels to be beset in the most cold arctic conditions and it can also be used as a steering device.

During the years the system has been installed both into newbuild and old ship. Some systems have been even for seasonal use with capability to be removed for summer season.

New techologies in ship operation, for instance, azimuthing thrusters and operation in double acting mode have reduces the use of the system for normal icebreaking vessels.

However, with the rising interest of offshore industry to the Arctic there will be built a number of stationary drilling units, floating storage/production facilities, which need special attention what comes to keeping the friction between the hull surface and ice on low level, and prevent ice from freezing on the hull as well as helping out doing so called "self ice management".

The paper is a summary of experience gained so far, benefits of the system and how the future oil & gas industry could benefit and some ideas for new ways of using the system.

Background

The air bubbling system was originally developed in the late 1960ies. The main idea is to produce an air flow between the vessel hull and ice to decrease the friction. The system would replace the need to have bow propellers.
Methane Hydrate Dissociation by Depressurization in a Mount Elbert Sandstone Sample: Experimental Observations and Numerical Simulations
Authors: Kneafsey Timothy J. , Moridis George J.
Published: December 2011

A preserved sample of hydrate-bearing sandstone from the Mount Elbert Test Well was dissociated by depressurization while monitoring the internal temperature of the sample in two locations and the density changes at high spatial resolution using x-ray CT scanning. The sample contained two distinct regions having different porosity and grain size distributions. The hydrate dissociation occurred initially throughout the sample as a result of depressing the pressure below the stability pressure. This initial stage reduced the temperature to the equilibrium point, which was maintained above the ice point. After that, dissociation occurred from the outside in as a result of heat transfer from the controlled temperature bath surrounding the pressure vessel. Numerical modeling of the test using TOUGH+HYDRATE yielded a gas production curve that closely matches the experimentally measured curve.

Introduction

R ecent studies have concluded that methane hydrate (hereafter hydrate), a naturally occurring clathrate compound consisting of molecular water cages surrounding gas molecules (primarily methane), contains large quantities of methane in shallow sediments throughout the world's coastal margins and polar regions [Boswell et al., 2010; Milkov, 2004; Sloan et al., 1998]. Each cubic meter of hydrate can hold approximately 160 m3 of natural gas at standard temperature and pressure [National Resource Council, 2004]. Even though natural gas from hydrate shows great promise as an energy resource, scientific and engineering questions remain regarding producing gas from hydrates. Three methods are typically considered to produce gas from hydrate: depressurization, where the system pressure is lowered below the hydrate stability pressure; thermal stimulation, where the hydrate-bearing sediments are heated to temperatures in excess of the hydrate stability temperature, and the use of inhibitors such as sodium chloride or alcohols that modify the hydrate stability conditions to destabilize the hydrate [Sloan and Koh, 2008]. Of these techniques, heating the hydrate-bearing sediments and injecting expensive alcohols or corrosive brines may have limited applications, but will often be impractical, particularly considering the size of reservoirs and the lack of control that can be exerted to directly apply the heat or inhibitor to the location needed. Depressurization is expected to be effective in many situations, however the hydrate-bearing sediments must be well enough confined by low permeability strata for the depressurization to be effective.
Intravascular papillary endothelial hyperplasia of the bladder: Case report and review of the literature
Authors: Jazaerly Tarek , Jaratli Hayan , Sakr Wael , Almardini Nour , Urabi Muaz , Dhar Nivedita , Giorgadze Tamar
Published: December 2011

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson′s tumor, is a benign unusual vascular lesion thought to arise from an organizing thrombus. Histologically, IPEH is characterized by papillary fronds lined by proliferating endothelium that may mimic angiosarcoma, and therefore the correct diagnosis may prevent unnecessary radical procedures. Involvement of the bladder is extremely rare, with only three cases reported in the literature. We report a case of IPEH arising in the bladder of a patient with history of prostate cancer treated with radiotherapy.
Modelled and measured effects of clouds on UV Aerosol Indices on a local, regional, and global scale
Authors: Penning de Vries M. , Wagner T.
Published: December 2011

Abstract. The UV Aerosol Indices (UVAI) form one of very few available tools in satellite remote sensing that provide information on aerosol absorption. The UVAI are also quite insensitive to surface type and are determined in the presence of clouds – situations where most aerosol retrieval algorithms do not work. The UVAI are most sensitive to elevated layers of absorbing aerosols, such as mineral dust and smoke, but they can also be used to study non-absorbing aerosols, such as sulphate and secondary organic aerosols. Although UVAI are determined for cloud-contaminated pixels, clouds do affect the value of UVAI in several ways: (1) they shield the underlying scene (potentially containing aerosols) from view, (2) they enhance the apparent surface albedo of an elevated aerosol layer, and (3) clouds unpolluted by aerosols also yield non-zero UVAI, here referred to as "cloudUVAI". The main purpose of this paper is to demonstrate that clouds can cause significant UVAI and that this cloudUVAI can be well modelled using simple assumptions on cloud properties. To this aim, we modelled cloudUVAI by using measured cloud optical parameters – either with low spatial resolution from SCIAMACHY, or high resolution from MERIS – as input. The modelled cloudUVAI were compared with UVAI determined from SCIAMACHY reflectances on different spatial (local, regional and global) and temporal scales (single measurement, daily means and seasonal means). The general dependencies of UVAI on cloud parameters were quite well reproduced, but several issues remain unclear: compared to the modelled cloudUVAI, measured UVAI show a bias, in particular for large cloud fractions. Also, the spread in measured UVAI is larger than in modelled cloudUVAI. In addition to the original, Lambert Equivalent Reflector (LER)-based UVAI algorithm, we have also investigated the effects of clouds on UVAI determined using the so-called Modified LER (MLER) algorithm (currently applied to TOMS and OMI data). For medium-sized clouds the MLER algorithm performs better (UVAI are closer to 0), but like for LER UVAI, MLER UVAI can become as large as −1.2 for small clouds and deviate significantly from zero for cloud fractions near 1. The effects of clouds should therefore also be taken into account when MLER UVAI data are used. Because the effects of clouds and aerosols on UVAI are not independent, a simple subtraction of modelled cloudUVAI from measured UVAI does not yield a UVAI representative of a cloud-free scene when aerosols are present. We here propose a first, simple approach for the correction of cloud effects on UVAI. The method is shown to work reasonably well for small to medium-sized clouds located above aerosols.