bluuebunny/crossref_metadata_2025 huggingface dataset:
Qualification Testing Of Flexible Pipes For 3000m Water Depth
Authors: Bectarte Fabrice , Secher Philippe , Felix-Henry Antoine
Published: May 2011

The paper is relevant to riser technology and specifically, qualification of flexible pipes for water depths up to 3,000m.

This paper describes a comprehensive program aimed at the qualification of flexible pipes for ultradeep water applications. The primary design driver for ultradeep water flexible pipe applications is the resistance to hydrostatic pressure, in combination with dynamic curvature cycling. The two associated critical failure modes are hydrostatic collapse and lateral buckling of armour wires.

Technip have developed dedicated flexible pipe components to address the severe loading conditions encountered in water depths up to 3,000m. Hydrostatic collapse resistance has been addressed by a thick inner carcass layer and a PSI pressure vault. Armour wire lateral buckling, which is induced by axial compression in the armour wires in combination with dynamic curvature cycling, has been addressed by the design and industrialization of new tensile armour wires.

The design qualification process for these improvements was completed on two levels. Initially, a large number of pipes were subjected to dynamic cycling testing under high hydrostatic pressure in a hyperbaric chamber so as to determine design limits in terms of pipe diameter, water depth and component sizing. Then, design combinations were selected for testing in a real deepwater environment in the Gulf of Mexico. This second level of tests referred as Deep Immersion Performance (DIP) tests aimed at validating the results obtained from hyperbaric chamber tests. The DIP tests replicated the actual design conditions to which a flexible pipe would be subjected during installation and operation.

The development of new and modified flexible pipe components provided a suite of flexible pipe designs suitable for extended water depth application. The final phase of the qualification program, namely the DIP tests, was completed in 2010. It provided design limitations of the new designs for both 9?? and 11?? internal diameter flexible pipes, in sweet and sour service in water depths up to 3,000m

This paper clearly demonstrates the suitability of flexible pipes as a valid solution for ultradeep water applications as long as the mechanical behavior of the pipe components is adequately addressed.

1. Introduction and objectives

The objective of this paper is to describe the comprehensive R&D project for the qualification of flexible pipes in water depths up to 3000m.

The main and primary purpose of this R&D program was to demonstrate that the validation range of our flexible pipes can be extended from depths of 2000 m (as it was before project) to beyond today's market needs in Brazil and the Gulf of Mexico (Figure 1), i.e.3000 m for flexible pipe risers between 7?? and 9??2400 m for 11?? flexible pipe risers.

A secondary objective was to extend to 3000 m, the validity range of our design models and of our testing methodology.
Generation of Best Practices in Flow Assurance Using a Transient Hydrate Kinetics Model
Authors: Zerpa Luis Eduardo , Sloan E. Dendy , Sum Amadeu , Koh Carolyn
Published: May 2011

The paper highlights the importance of developing a comprehensive gas hydrate model in flow assurance for the oil and gas industry. The comprehensive model should account for mechanisms present in different systems of oil/gas production. Since this kind of tool could be seen as complex and difficult to use, the main focus of the paper is to present an example of generation of "best practices" that can address the needs of a general flow assurance community, using a gas hydrate model developed for oil-dominated systems. The example illustrates the restart of an offshore well, using a typical geometry and fluid properties from the Caratinga Field located at Campos Basin, Brazil. Two extreme cases are studied to identify the worse case scenario, one considering a water-in-oil stable emulsion and the other where water is allowed to separate from the continuous oil phase. Then, the restart procedure of the case with higher risk of forming a hydrate plug is optimized to minimize hydrate formation and plugging risk. From the comparison of the two cases studied, it is concluded that systems with free water have a higher risk of plugging with hydrates. The optimization of the restart of a well shows that a slow restart of the well minimizes the formation of hydrates, decreasing the risk of plugging. The main conclusion is that the gas hydrate model can be used as a tool for the generation of "best practices" for gas hydrates in flow assurance.

Introduction

Flow assurance is a technical discipline of the oil and gas industry that focuses on the design of safe and secure operation techniques for the uninterrupted transport of reservoir fluids from the reservoir to the point of sale. Offshore explorations in deeper and colder waters impose more challenging scenarios to the flow assurance of the produced streams, requiring production facilities with longer subsea tiebacks for the transport of hydrocarbons from the wellhead to production/processing platforms. These facilities may operate at high pressures and low temperatures promoting the formation of gas hydrates, crystalline compounds formed by hydrogen-bonded water molecules in a lattice structure that is stabilized by encapsulating a small guest molecule, like methane or ethane (Sloan and Koh, 2008). One of the most challenging problems in flow assurance is the plugging of pipelines due to rapid formation of gas hydrates compared to other solid deposits (Sloan, 2005).

The formation of gas hydrates in an oil-dominated multiphase flow system containing water, oil, and gas, can be described using the conceptual model illustrated in Figure 1, where hydrates form at the interface of water droplets entrained in the continuous oil phase. In the oil phase, these hydrate-encrusted water droplets can agglomerate increasing into larger hydrate masses, leading to an increase in the slurry viscosity, which can eventually form a plug (Turner, 2005).
Deepwater Seafloor Resource Production - The Bismarck Sea Development Project
Authors: Smith Glen
Published: May 2011

Nautilus Minerals, the world's leader in exploration and development of deep ocean seafloor resources, has located a number of high grade copper and gold Seafloor Massive Sulphide (SMS) deposits in the Bismarck Sea, Papua New Guinea (PNG). Nautilus' business model is based on the notion of ongoing resource accumulation and " aggregation?? of numerous high grade SMS systems to sequentially develop using an offshore production system. Nautilus' record of discovery of new SMS systems in clusters in the Bismarck Sea and in Tonga is in keeping with " camps?? of land based Volcanic Hosted Massive Sulphide (VHMS) systems that form a significant part of the world's reserves of copper, lead and zinc.

Nautilus' development plan is to commence production at its Solwara 1 site located within Mining Lease (ML) 154. As of January 2011, the indicated and inferred mineral resources attributed to the Solwara 1 deposit are 870 kT and 1,300 kT respectively. Nautilus is continuing an exploration and resource evaluation program with the expectation that Solwara 1 and other prospects in its Bismarck Sea tenement holdings will translate into an increased aggregated commercially viable reserve.

This paper summarises a progress update of Nautilus' development plans which will provide a new source of minerals for the world and create a clear benchmark in environmental and community standards for this emerging frontier.

Introduction

Nautilus is focused on its exploration and development plans for the recovery of high grade copper and gold in SMS mineralisation. These mineralised belts, analogous to land based VHMS deposits, are typically located in areas associated with submarine volcanic activity along deepwater mid-ocean ridges or back-arc basins.

Nautilus' exploration programmes have predominantly focused on the Bismarck Sea, a benign body of water within the territorial waters of Papua New Guinea. Nautilus has used or adapted existing technologies to achieve a very high success rate in generating and converting targets into high grade SMS mineralised discoveries.

Nautilus' first development project is located at an approximate water depth of 1,600 m at its Solwara 1 site. Its plans have focused on the use of existing technology and market leaders in the development of an offshore production system that can be relocated and re-used on subsequent sites.
Frigg Decommissioning: Onshore Disposal
Authors: Oram Michael Ellis
Published: May 2011

This paper describes the work methodology for the handling of all offshore inventory landed at the onshore disposal sites. Specific items which are addressed include:Introduction including Company role, total tonnage & relevant Authorities.Deconstruction & Disposal worksites including location and capacity.Onshore disposal process including preparations for receipt of inventory, safety inspection, removal of hazardous waste & removal of items for re-use or sale.Demolition methods including mechanical cutting (cold) & hot cutting.Classification of inventory for disposal.Handling & disposal of hazardous waste.Jacket dismantling including two alternative methods.Safety Management Systems employed.Onshore man-hours.Jacket tdismantling.Lessons learnt.
Renewable Energy and Historic Preservation on the Pacific Outer Continental Shelf
Authors: Ball Dave
Published: May 2011

Under the Energy Policy Act of 2005 the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE) is responsible for leasing renewable energy activities on the Outer Continental Shelf (OCS). Included among these activities are offshore data collection devices, wind turbines and marine hydrokinetic (MHK) facilities, such as wave and current generators. As with any federal action or undertaking, an assessment of potential impacts to the environment, including cultural resources, is required. This paper provides an introduction to BOEMRE's offshore renewable energy program and the protection of underwater cultural heritage on the Pacific OCS. Included is a summary of energy activities on the Pacific OCS and BOEMRE environmental studies designed to provide information for compliance reviews under Section 106 of the National Historic Preservation Act.

Introduction

Acquisition of offshore energy and mineral resources has occurred in the federal waters of the Outer Continental Shelf (OCS) for over sixty years. For most of that time, the focus has been primarily on exploration and development of hydrocarbon resources (e.g., oil and gas). Oversight of these activities on the OCS currently lies with the Bureau of Ocean Energy Management, Regulation and Enforcement (BOEMRE). In addition to oil and gas activities, BOEMRE is responsible for granting access to OCS sand and gravel for coastal restoration projects. With passage of the 2005 Energy Policy Act, BOEMRE's responsibility also now includes offshore renewable energy, with a focus on wind and marine hydrokinetic (MHK) projects. As interest in renewable energy on the OCS takes shape, the technologies to harness wind and MHK energy continue to improve. Likewise, regulations to ensure environmentally safe development of these resources are also advancing.

Pacific Region Development

Offshore oil drilling in the U.S. began off the California coast near Santa Barbara in 1896, when a drilling rig was erected on a pier that extended approximately 300 feet from shore. Fifty-one years later, in 1947, the first offshore well was completed out of site of land by Kerr-McGee off the Louisiana coast. Since that time, the offshore oil and gas industry has grown, and today development is concentrated primarily on hydrocarbon resources in the Gulf of Mexico (Austin et al., 2004).

On the Pacific OCS, oil and gas development has been limited not only by congressional moratoria, which were in place from 1982 through 2008, but also as a result of state and local opposition to offshore oil and gas development along the West Coast. However, production continues in this region on leases issued prior to 1984. Currently, there are 49 active oil and gas leases on the Pacific OCS, located roughly between Huntington Beach and Pismo Beach, along the southern California coast.
Efficient Perforation Of High-Pressure Deepwater Wells
Authors: Sanders William , Baumann Carlos Erik , Williams Harvey Alec Rodney , de Moraes Flavio Dias , Shipley Jonathan , Bethke Martin Eric , Ogier Scott
Published: May 2011

This paper describes the planning, logistics, and technology used in Cascade and Chinook, the two largest deepwater high-pressure perforation jobs successfully executed to date in the Gulf of Mexico (GoM). These Lower Tertiary well completions have gross perforation intervals over 800 feet and downhole pressures higher than 19,000 psi. This paper discusses the technology used in the planning stages to predict gunshock loads on completion equipment, and the logistics and procedures used to minimize costs, rig time and risks while maintaining safe operations.

Perforating several intervals in one run was required to complement a single-trip multi-zone frac-pack system in which all downhole packers, screens and service tools are run at once, and all zones are stimulated in a single trip. Perforating all intervals with long gunstrings and then frac packing multiple zones in a single trip saves substantial rig time compared with performing conventional stacked frac packed completions requiring multiple trips per perforated zone.

Thousands of perforating jobs are conducted successfully worldwide each month. However, there are a small number of jobs, typically high-pressure deepwater wells, where gun shock is a real and significant risk. When planning perforation jobs in deepwater high-pressure wells, engineers strive to minimize the risk of equipment damage due to perforating gunshock loads, such as bent tubing and unset packers, and a potential fishing job. For Cascade and Chinook, peak gunshock loads were evaluated with software that predicts the pressure waves in the completion fluid, and the associated structural loads on all well components.

Fast gauge pressure data shows that predicted wellbore pressure transients are sufficiently accurate both in magnitude and time when the input reservoir response data is close to the actual field data.

We discuss in detail the logistics and procedures used for loading and transportation of guns, building the BHA, and running the gun string in the well. The logistics for mobilizing over 700 lbs of explosives requires extensive planning to minimize time and costs. Minimizing the time needed for each gun connection is crucial to minimize rig time, and several approaches were employed.

The logistics and procedures outlined in this paper led to a rig time reduction of over 67% for the execution of the largest deepwater high-pressure perforation jobs done to date in the Gulf of Mexico.
Computational Analysis of Oil Spill in Shallow Water due to Wave and Tidal Motion
Authors: Agrawal Madhusuden , Dakshinamoorthy Duraivelan
Published: May 2011

Oil and gas consumption is vital for sustained economic growth. With many developing countries progressing towards prosperity, oil and gas consumption demand increases every year. Oil spills due to major accidents hamper the growth and development of the oil and gas industries. Oil spills also cause serious damage to ocean environment and most of the spills take months or years to cleanup. With the recent unfortunate event of a large scale oil spill in Gulf of Mexico, it is clearly evident that such accidents must be prevented from happening or at least efforts must be taken to mitigate the effects of oil spill during such accidents. In order to mitigate the effects, one needs to predict the accurate trajectory of oil films during a spill event, so that appropriate actions can be taken in a timely manner. Over past three decades, simplified empirical correlations are most commonly used in evaluation of the oil slick spreading. Latest developments in computational fluid dynamics and increased computational resources have provided an opportunity to develop a comprehensive model for oil spill problem.

In this current study, a detailed Computational Fluid Dynamics (CFD) based study is proposed to predict the trajectory of oil film during various spill scenarios in shallow water drilling. Three dimensional simulations were conducted for different wave and current conditions. A three phase (Oil, water and air) Volume of Fluid (VOF) multiphase model was used to capture the trajectory of oil film. Open channel wave boundary conditions were used to simulate the propagation of sea waves. The sea water wave profile was described by a Fifth-Order Stokes theory. The presented results clearly show the advantages of using this methodology in predicting the trajectory of oil film during various spill scenarios. The results of these CFD studies show that ocean wave profile and current have important effects on the location, and the extent of oil film on sea surface. The polluted area increases with higher interaction of wave and current. At high wavelength, oil dispersion underwater increases and the extent of oil film on sea surface increases. However at high wave amplitude, the extent of oil film on surface decreases. The presented CFD model clearly shows the value of using CFD simulations to predict the trajectory of oil on the sea surface during various oil spill scenarios. This in turn could help in mitigating the effects of oil spill and also help in clean-up activities.
Development of Floating LNG Production Units with Modular/Scalable SMR Processes
Authors: Talib Javid Husain , Price Brian
Published: May 2011

The world wide market for LNG continues to grow rapidly. Traditionally, base load LNG plants have provided the majority of this LNG supply. As the industry has grown, base load plants have grown increasing larger and more difficult to site. Additionally, the number of fields with sufficient reserves is diminishing. Owners are now turning to developing mid-scale projects with Floating LNG production systems. A variety of configurations have been put forth and a few are progressing.

The single mixed refrigerant process offers an excellent approach to developing the topsides process units required for LNG production. With real estate on floating structures at a premium, compact, modular facilities are a must. The SMR process is readily modular and scalable to fit the production profile of these projects. Modular concepts from 0.5 MMTPA to 6.0 MMTPA have been developed to fit both tanker retrofits and new build ships. Also, the process offers significant reduction in equipment and power versus expander based processes.

This paper will cover the technology as applied to floating structures with emphasis on efficiency and footprint for a variety of feed gas applications.

Offshore Process Requirements

LNG production facilities to date have all been onshore locations. While many of the same processes are used for both onshore and offshore locations, the requirements for offshore developments are unique to this environment. Some of the key criteria include:Minimizing footprint- Offshore real estate is the critical item in project cost. The minimization of the footprint of the process plant is essential to developing an economically attractive project.Minimize equipment items- The key objective for the process units to achieve an optimal footprint is to minimize the number and complexity of the equipment needed. Single mixed refrigerants produce the lowest equipment count of all processes.Minimize weight and single module lift weights - The cost of structures to support the equipment and modules is a key cost item. Also the lift weight of the individual modules is critical.Minimize module interconnections- The simplification of processes to minimize interconnections reduces the cost and complexity of the installation. Multiple loop refrigeration systems suffer from extreme numbers of interconnections between the loops.Accessibility- The offshore process systems must be accessible for maintenance and egressFlexibility to handle multiple feed gas cases- Onshore developers have learned (some the hard way) the liquefaction processes need to be able to handle a range of feed gases. Single mixed refrigerants excel in this area due to ease of changing the system during operation.
Carbon Capture and Sequestration: The U.S. Department of Energy's R&D Efforts to Characterize Opportunities for Deep Geologic Storage of Carbon Dioxide in Offshore Resources
Authors: Litynski John , Brown B.M. , Vikara D.M. , Srivastava R.D.
Published: May 2011

The United States Department of Energy (DOE) is the lead federal agency for the research, development, demonstration, and deployment (RDD&D) of carbon sequestration technologies. This effort is being implemented through several activities, including applied research and development (R&D), demonstration projects, and technical support to loan guarantee and tax incentives programs. The sequestration program started in 1997 and has grown significantly. In Fiscal Year 2010, $145 million in federal funding was received to support carbon capture and storage (CCS) related R&D. The Sequestration Program also received $80 million in funding from the 2009 American Recovery and Reinvestment Act (ARRA) to support the development of resources for geologic storage of CO2. The goal of the program is to develop a suite of technologies that can support the implementation of commercial CCS projects by 2020.

Part of the program funding is being used to assess the potential for storing CO2 in offshore geologic formations. This paper presents an overview of projects awarded to assess the potential for geologic storage in state and federal waters in the Gulf of Mexico (GOM), the Atlantic and Pacific Oceans, and in Texas and California state territorial waters, as well as research efforts DOE is supporting world-wide. These efforts are aimed at capacity assessments; monitoring and modeling of sub-seabed storage projects; characterization of projects that are drilling wells and conducting seismic surveys; and assessment of regulatory gaps relative to storing CO2 in offshore formations. The results are expected to provide a summary of basin-scale suitability and will identify and prioritize potential offshore CO2 geological storage opportunities.

Introduction

Fossil fuels are projected to be the primary source of energy for the United States and most developed and developing countries over the next several decades, and their consumption is expected to increase. Atmospheric levels of carbon dioxide (CO2) have risen significantly from preindustrial levels of 280 parts per million (ppm) to present levels of around 384 ppm (Tans, 2008). Evidence suggests that the observed rise in atmospheric CO2 levels is the result of expanded use of fossil fuels for energy. The concentration of CO2 in the atmosphere is expected to rise due to the anticipated increase in fossil fuel usage unless major advances in energy management and production are made (Socolow et al., 2004; Greenblatt and Sarmiento, 2004). Carbon capture and storage (CCS) is an emerging strategy for preventing the emission of anthropogenic CO2 into the atmosphere. The long-term storage of anthropogenic CO2 is a promising technology for slowing, and ultimately reversing, the build-up of greenhouse gas (GHG) emissions in the atmosphere (NETL, 2009).
New Method for Managing Hydrates in Deepwater Tiebacks
Authors: Creek Jefferson Louis , Subramanian Sivakumar , Estanga Douglas Alexander
Published: May 2011

This paper will discuss holistic application and integration of existing technology to manage hydrate formation and potential blockage in subsea tiebacks. The paper will cover how careful examination of the nature of the reservoir fluids and properties can be used to advantage in subsea field developments to facilitate strategies different from "first principal" techniques such as chemicals and insulation that are aimed at preventing hydrate formation altogether. In many developments such methods would be expensive potentially to the point of preventing economic development of a particular asset. In the present work a combination of modern flow and thermodynamic simulation tools in conjunction with judicious testing to verify key assumptions have been used to develop an operational hydrate management philosophy of "doing nothing" under certain circumstances. In fact it is suggested that hydrates can form without any significant blockage risk to operations.

The concept is based on allowing hydrates to form in a limited fashion. Aspects of the concept have been discussed and demonstrated in field and laboratory applications within industry forums such as the Deepstar Flow Assurance program.

Introduction

Many considerations enter into the flow assurance philosophy and design for a given project development. Of the many tasks, the planning for managing hydrate formation usually requires the most effort in terms of time and planning. Hydrate mitigation and management in a deepwater oil system typically ends up being comprised of a collection of strategies that involve thermal management (eg. insulation of subsea equipment and flowlines to retain heat and provide cooldown time), chemical injection (eg. pumping methanol and or low dosage hydrate inhibitor during shutdowns and restarts), pressure reduction (eg. blowdown), and fluid composition management (eg. dead oil displacement during extended shutdowns). The hydrate management philosophy therefore has a significant impact on hardware design and operating procedures.
Involvement of Tyrosine Kinase-2 in Both the IL-12/Th1 and IL-23/Th17 Axes In Vivo
Authors: Ishizaki Masayuki , Akimoto Toshihiko , Muromoto Ryuta , Yokoyama Mika , Ohshiro Yuya , Sekine Yuichi , Maeda Hiroaki , Shimoda Kazuya , Oritani Kenji , Matsuda Tadashi
Published: May 2011

Tyrosine kinase-2 (Tyk2), a member of the Jak family of kinases, mediates the signals triggered by various cytokines, including type I IFNs, IL-12, and IL-23. In the current study, we investigated the in vivo involvement of Tyk2 in several IL-12/Th1– and IL-23/Th17–mediated models of experimental diseases, including methylated BSA injection-induced footpad thickness, imiquimod-induced psoriasis-like skin inflammation, and dextran sulfate sodium- or 2,4,6-trinitrobenzene sulfonic acid-induced colitis. In these disease models, Tyk2 deficiency influenced the phenotypes in immunity and/or inflammation. Our findings demonstrate a somewhat broader contribution of Tyk2 to immune systems than previously expected and suggest that Tyk2 may represent an important candidate for drug development by targeting both the IL-12/Th1 and IL-23/Th17 axes.
Y-Box Binding Protein-1 Mediates Profibrotic Effects of Calcineurin Inhibitors in the Kidney
Authors: Hanssen Lydia , Frye Björn C. , Ostendorf Tammo , Alidousty Christina , Djudjaj Sonja , Boor Peter , Rauen Thomas , Floege Jürgen , Mertens Peter R. , Raffetseder Ute
Published: May 2011

The immunosuppressive calcineurin inhibitors (CNIs) cyclosporine A (CsA) and tacrolimus are widely used in transplant organ recipients, but in the kidney allograft, they may cause tubulointerstitial as well as mesangial fibrosis, with TGF-β believed to be a central inductor. In this study, we report that the cold-shock protein Y-box binding protein-1 (YB-1) is a TGF-β independent downstream effector in CsA- as well as in tacrolimus- but not in rapamycin-mediated activation of rat mesangial cells (rMCs). Intracellular content of YB-1 is several-fold increased in MCs following CNI treatment in vitro and in vivo in mice. This effect ensues in a time-dependent manner, and the operative concentration range encompasses therapeutically relevant doses for CNIs. The effect of CNI on cellular YB-1 content is abrogated by specific blockade of translation, whereas retarding the transcription remains ineffective. The activation of rMCs by CNIs is accomplished by generation of reactive oxygen species. In contrast to TGF-β–triggered reactive oxygen species generation, hydrogen peroxide especially could be identified as a potent inductor of YB-1 accumulation. In line with this, hindering TGF-β did not influence CNI-induced YB-1 upregulation, whereas ERK/Akt pathways are involved in CNI-mediated YB-1 expression. CsA-induced YB-1 accumulation results in mRNA stabilization and subsequent generation of collagen. Our results provide strong evidence for a CNI-dependent induction of YB-1 in MCs that contributes to renal fibrosis via regulation of its own and collagen translation.
Morphological Analysis of CDC2 and Glycogen Synthase Kinase 3βPhosphorylation as Markers of G2 → M Transition in Glioma
Authors: Otero José Javier , Tihan Tarik
Published: May 2011

G2 → M transition is a strategic target for glioma chemotherapy. Key players in G2 → M transition include CDC2 and glycogen synthase kinase 3β(GSK3β), which are highly regulated by posttranslational phosphorylation. This report is a morphological analysis of CDC2 and GSK3βphosphorylation using immunohistochemistry in gliomas with different biological properties. GBM showed a 2.8-fold and 5.6-fold increase in number of cells positive for pThr161CDC2 and a 4.2- and 6.9-fold increase in number of cells positive for pTyr15CDC2 relative to oligodendroglioma and ependymoma, respectively. Elevated labeling for inhibited phospho-CDC2 (pTyr15CDC) correlates with elevated levels of phosphorylated glycogen synthase kinase 3β(GSK3β). 71% of the GBM cases showed intermediate to high intensity staining for pSer9SGK3β53% of oligodendroglioma, and 73% of ependymoma showed low intensity staining. CDC2 gene amplification correlates with increased survival in glioblastoma multiforme (GBM) and astrocytoma WHO grades II-III, but not in oligodendroglioma WHO grades II-III.
Nonmotor Symptoms Groups in Parkinson's Disease Patients: Results of a Pilot, Exploratory Study
Authors: Perez Lloret Santiago , Rossi Malco , Merello Marcelo , Rascol Olivier , Cardinali Daniel P.
Published: May 2011

Nonmotor symptoms (NMS) like neuropsychiatric symptoms, sleep disturbances or autonomic symptoms are a common feature of Parkinson's disease (PD). To explore the existence of groups of NMS and to relate them to PD characteristics, 71 idiopathic non-demented PD out-patients were recruited. Sleep was evaluated by the PD Sleep Scale (PDSS). Several neuropsychiatric, gastrointestinal and urogenital symptoms were obtained from the NMSQuest. Sialorrhea or dysphagia severity was obtained from the Unified PD Rating Scale activities of daily living section. MADRS depression scale was also administered. Exploratory factor analysis revealed the presence of 5 factors, explaining 70% of variance. The first factor included PDSS measurement of sleep quality, nocturnal restlessness, off-related problems and daytime somnolence; the second factor included nocturia (PDSS) and nocturnal activity; the third one included gastrointestinal and genitourinary symptoms; the forth one included nocturnal psychosis (PDSS), sialorrhea and dysphagia (UPDRS); and the last one included the MADRS score as well as neuropsychiatric symptoms. Sleep disorders correlated with presence of wearing-off, nocturia with age >69 years, and nocturnal psychosis with levodopa equivalent dose or UPDRS II score. Neuropsychiatric symptoms correlated with UPDRS II+III score and non-tricyclic antidepressants. These results support the occurrence of significant NMS grouping in PD patients.
Serpin Inhibition Mechanism: A Delicate Balance between Native Metastable State and Polymerization
Authors: Khan Mohammad Sazzad , Singh Poonam , Azhar Asim , Naseem Asma , Rashid Qudsia , Kabir Mohammad Anaul , Jairajpuri Mohamad Aman
Published: May 2011

The serpins (serineproteinaseinhibitors) are structurally similar but functionally diverse proteins that fold into a conserved structure and employ a unique suicide substrate-like inhibitory mechanism. Serpins play absolutely critical role in the control of proteases involved in the inflammatory, complement, coagulation and fibrinolytic pathways and are associated with many conformational diseases. Serpin's native state is a metastable state which transforms to a more stable state during its inhibitory mechanism. Serpin in the native form is in the stressed (S) conformation that undergoes a transition to a relaxed (R) conformation for the protease inhibition. During this transition the region called as reactive center loop which interacts with target proteases, inserts itself into the center ofβ-sheet A to form an extra strand. Serpin is delicately balanced to perform its function with many critical residues involved in maintaining metastability. However due to its typical mechanism of inhibition, naturally occurring serpin variants produces conformational instability that allows insertion of RCL of one molecule into theβ-sheet A of another to form a loop-sheet linkage leading to its polymerization and aggregation. Thus understanding the molecular basis and amino acid involved in serpin polymerization mechanism is critical to devising strategies for its cure.
Chemical and Physicochemical Pretreatment of Lignocellulosic Biomass: A Review
Authors: Brodeur Gary , Yau Elizabeth , Badal Kimberly , Collier John , Ramachandran K. B. , Ramakrishnan Subramanian
Published: May 2011

Overcoming the recalcitrance (resistance of plant cell walls to deconstruction) of lignocellulosic biomass is a key step in the production of fuels and chemicals. The recalcitrance is due to the highly crystalline structure of cellulose which is embedded in a matrix of polymers-lignin and hemicellulose. The main goal of pretreatment is to overcome this recalcitrance, to separate the cellulose from the matrix polymers, and to make it more accessible for enzymatic hydrolysis. Reports have shown that pretreatment can improve sugar yields to higher than 90% theoretical yield for biomass such as wood, grasses, and corn. This paper reviews different leading pretreatment technologies along with their latest developments and highlights their advantages and disadvantages with respect to subsequent hydrolysis and fermentation. The effects of different technologies on the components of biomass (cellulose, hemicellulose, and lignin) are also reviewed with a focus on how the treatment greatly enhances enzymatic cellulose digestibility.
The trochanteric fat pad
Authors: Panettiere P. , Accorsi D. , Marchetti L. , Minicozzi A.M. , Orsini G. , Bernardi P. , Benati D. , Conti G. , Sbarbati A.
Published: May 2011

Technological developments based on the use of autologous white adipose tissue (WAT) attracted attention to minor fat depots as possible sources of adipose tissue. In plastic surgery, the trochanteric fatty pad is one of the most used WAT depots for its location and organoleptic characteristics that make it particularly suitable for reconstructive procedures. Despite its wide use in clinic, the structure of this depot has never been studied in detail and it is not known if structural differences exist among trochanteric fat and other subcutaneous WAT depots. The present study was performed on trochanteric fat pad with the aim to clarify the morphology of its adipocytes, stroma and microcirculation, with particular reference to the stem niches. Histological and ultrastructural studies showed that the main peculiar feature of the trochanteric fat concerns its stromal component, which appears less dense than in the other subcutaneous WATs studied. The intra-parenchymal collagen stroma is poor and the extracellular compartment shows large spaces, filled with electron-light material, in which isolated collagen bundles are present. The adipocytes are wrapped in weak and easily detachable collagen baskets. These connective sheaths are very thin compared to the sheaths in other subcutaneous WAT depots. The capillaries are covered by large, long and thin elements surrounded by an external lamina; these perivascular cells are poor in organelles and mainly contain poly-ribosomes. In conclusion, when compared to other WAT deposits, the trochanteric fatty pad shows structural peculiarities in its stroma and microcirculation suggesting a high regenerative potential. Resistance, dissociability, microvascular weft and high regenerative potential make the trochanteric fatty pad a privileged source for harvesting in autologous WAT-based regenerative procedures.
Comparison of two different sea-salt aerosol schemes as implemented in air quality models applied to the Mediterranean Basin
Authors: Jiménez-Guerrero P. , Jorba O. , Pay M. T. , Montávez J. P. , Jerez S. , Gómez-Navarro J. J. , Baldasano J. M.
Published: May 2011

Abstract. A number of attempts have been made to incorporate sea-salt aerosol (SSA) source functions in chemistry transport models with varying results according to the complexity of the scheme considered. This contribution compares the inclusion of two different SSA algorithms in two chemistry transport models: CMAQ and CHIMERE. The main goal is to examine the differences in average SSA mass and composition and to study the seasonality of the prediction of SSA when applied to the Mediterranean area with high resolution for a reference year. Dry and wet deposition schemes are also analyzed to better understand the differences observed between both models in the target area. The applied emission algorithm in CHIMERE uses a semi-empirical formulation which obtains the surface emission rate of SSA as a function of the particle size and the surface wind speed raised to the power 3.41. The emission parameterization included within CMAQ is somehow more sophisticated, since fluxes of SSA are corrected with relative humidity. In order to evaluate their strengths and weaknesses, the participating algorithms as implemented in the chemistry transport models were evaluated against AOD measurements from Aeronet and available surface measurements in Southern Europe and the Mediterranean area, showing biases around −0.002 and −1.2 μg m−3, respectively. The results indicate that both models represent accurately the patterns and dynamics of SSA and its non-uniform behavior in the Mediterranean basin, showing a strong seasonality. The levels of SSA strongly vary across the Western and the Eastern Mediterranean, reproducing CHIMERE higher annual levels in the Aegean Sea (12 μg m−3) and CMAQ in the Gulf of Lion (9 μg m−3). The large difference found for the ratio PM2.5/total SSA in CMAQ and CHIMERE is also investigated. The dry and wet removal rates are very similar for both models despite the different schemes implemented. Dry deposition essentially follows the surface drag stress patterns, meanwhile wet deposition is more scattered over the continent. CMAQ tends to provide larger amounts of SSA dry deposition over the Northern Mediterranean (0.7–1.0 g m−2 yr−1), meanwhile the Southeastern Mediterranean accounts for the maximum annual dry deposition in the CHIMERE model (0.9–1.5 g m−2 yr−1). The wet deposition is dominated by the accumulation mode and is strongly correlated to the precipitation patterns, showing CMAQ a higher wet deposition/total deposition ratio over coastal mountain chains. The results of both models constitute a step towards increasing the understanding of the SSA dynamics in a complex area as the Mediterranean.
Validation of an AOT product over land at the 0.6 μm channel of the SEVIRI sensor onboard MSG
Authors: Bernard E. , Moulin C. , Ramon D. , Jolivet D. , Riedi J. , Nicolas J. M.
Published: May 2011

Abstract. The Spinning Enhanced Visible and InfraRed Imager (SEVIRI) aboard Meteosat Second Generation (MSG) launched in 2003 by EUMETSAT is dedicated to the Nowcasting applications and Numerical Weather Prediction and to provide information for climate monitoring and research. We use the data in visible and near infrared channels to derive the Aerosol Optical Thickness (AOT) over land. The algorithm is based on the assumption that the Top Of the Atmosphere (TOA) reflectance increases with the aerosol load. This is a reasonable assumption except in case of absorbing aerosols above bright surfaces. We assume that the minimum in a 14-day time series of the TOA reflectance is, once corrected from gaseous scattering and absorption, representative of the surface reflectance. The AOT and the aerosol model (a set of 5 models are used), are retrieved by matching the simulated TOA reflectance with the TOA reflectances measured by SEVIRI in its visible and Near Infra-Red (NIR) spectral bands. The high temporal resolution of the data acquisition by SEVIRI allows to retrieve the AOT every 15 min with a spatial resolution of 3km at sub-satellite point, over the whole SEVIRI disk which covers Europe, Africa and part of South America. The resulting AOT, a Level 2 product at the same temporal and spatial resolution than SEVIRI, is presented and evaluated in this paper. The AOT has been validated using ground based measurements from AERONET, a sun-photometer network, focusing over Europe for 3 months in 2006. The SEVIRI estimates correlate well with the AERONET measurements, r = 0.64, with a slight underestimate, bias = −0.017. The sources of errors are mainly the cloud contamination and the bad estimation of the surface reflectance. The temporal evolutions exhibited by both dataset show very good agreement which allows to conclude that the AOT Level 2 product from SEVIRI can be used to quantify the aerosol content and to monitor its daily evolution with a high temporal frequency. The comparison with daily maps of MODIS AOT level 3 product shows qualitative good agreements in the retrieved geographic patterns of AOT. Given the high spatial and temporal resolutions obtained with this approach, our results have clear potential for applications ranging from air quality monitoring to climate studies.
A combined field and modeling study of groundwater flow in a tidal marsh
Authors:   Yuqiang Xia,   Hailong Li
Published: May 2011

Abstract. Bald mud beaches were found among the mangrove marshes in Dongzhaigang National Nature Reserve, Hainan, China. To investigate the possible reasons for this phenomenon, the intertidal zones of a mangrove transect and a bald beach transect with similar topography and same tidal actions were selected for comparison study. Along both transects, observed water table variations were significant in the high and low intertidal zones and negligible in the middle intertidal zones. Field investigations and observations invite two speculations: (1) existence of a high-permeability zone on each transect which underlies the low-permeability surface mud sediments and outcrops in the high intertidal zone, and (2) considerable inland freshwater recharge along the mangrove transect but negligible freshwater recharge along the bald beach transect. Two-dimensional numerical simulations based on these speculations gave results in line with the observed water table. The bald beach is most probably due to the lack of enough freshwater for generating a brackish beach soil condition essential to mangrove growth. It is also indicated that seawater infiltrated the high-permeability zone through its outcrop near the high intertidal zone, and discharged from the tidal river bank in the vicinity of the low tide line, thereby forming a tide-induced seawater-groundwater circulation which may provide considerable contribution to the total submarine groundwater discharge.
Geomorphological and geochemical characterization of the 11 August 2008 mud volcano eruption at S. Barbara village (Sicily, Italy) and its possible relationship with seismic activity
Authors: Madonia P. , Grassa F. , Cangemi M. , Musumeci C.
Published: May 2011

Abstract. On 11 August 2008 a paroxysmal eruption occurred at Santa Barbara mud volcano (MV), located close to Caltanissetta, one of the most densely populated cities of Sicily (Italy). An associated minor event took place on August 2009. Both the events caused severe damage to civil infrastructures located within a range of about 2 km from the eruptive vent. Geomorphological, geochemical, and seismological investigations were carried out for framing the events in the appropriate geodynamic context. Geomorphological surveys recognized, in the immediate surrounding of the main emission point, two different families of processes and landforms: (i) ground deformations and (ii) changes in morphology and number of the fluid emitting vents. These processes were associated to a wider network of fractures, seemingly generated by the shock wave produced by the gas blast that occurred at the main paroxysm. Geochemical characterization allowed an estimation of the source of the fluids, or at least their last standing, at about 3 km depth. Finally, the close time relationships observed between anomalous increments of seismic activity and the two main paroxysmal events accounted for a possible common trigger for both the phenomena, even with different timing due to the very different initial conditions and characteristics of the two processes, i.e. seismogenesis and gas overloading.
Cataract as a Phenotypic Marker for a Mutation in WFS1, the Wolfram Syndrome Gene
Authors: Cherif Titah Salah Mohamed , Meunier Isabelle , Blanchet Catherine , Lopez Severine , Rondouin Gerard , Lenaers Guy , Amati-Bonneau Patrizia , Reynier Pascal , Paquis-Flucklinger Veronique , Hamel Christian P.
Published: May 2011

Purpose

Wolfram syndrome (WS) or diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (DIDMOAD) (OMIM 222300) is an inherited neurodegenerative disease characterized by diabetes mellitus and optic atrophy as the 2 major criteria, followed later in life by deafness, diabetes insipidus, and various signs of neurologic impairment. The presence of a cataract has been variably mentioned in WS.

Method

Two members of a family had thorough ophthalmic examination and their DNA was screened for mutations in mitochondrial DNA, WFS1, OPA1, and OPA3 genes.

Results

We report a patient who first had surgery for bilateral cataract at age 5 and who subsequently presented typical signs of WS, i.e., diabetes mellitus, optic atrophy with reduced visual acuity at 20/400 on both eyes at age 22, and mild deafness. The patient was found to be a compound heterozygote for 2 truncating mutations in WFS1, the major WS gene. She carried the previously reported c.1231_1233 delCT and a novel c.2431_2465dup35 mutation. She also was heterozygote for a novel OPA1 sequence variant, c.929A>G in exon 9, whose pathogenicity remains uncertain. The patient's mother was a heterozygous carrier of the c.2431_2465dup35 mutation. She did not have diabetes mellitus or optic atrophy but had bilateral polar cataract. She did not carry the OPA1 sequence variant.

Conclusions

Cataract could be a marker for the WFS1 heterozygosity in this family, namely the c.2431_2465dup35 mutation.
Advances in Tailoring Resorcinol‐Formaldehyde Organic and Carbon Gels
Authors: ElKhatat Ahmed M. , Al‐Muhtaseb Shaheen A.
Published: May 2011

An overview on the preparation and properties of resorcinol‐formaldehyde (RF) organic and carbon gels reveals the fascinating and remarkably flexible properties of RF carbon and organic gels and how these properties are related to the synthesis and processing conditions. The structural properties can be easily tailored by rigidly controlling such conditions. However, slight variations in some conditions may cause drastic variations in the structural characteristics, and hence properties. Therefore, the effects of different conditions must be well‐understood before attempting to tailor organic or carbon gels to specific applications. The most important factors that affect the properties of an organic gel are the precursor concentrations, the catalyst type and concentration, the time and temperature of curing, and the drying method. In addition to these factors, characteristics of activated carbon gels also depend on the pyrolysis temperature and the activation method. These conditions impact the structural and performance characteristics significantly.