bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure Ridge Shapes and Slope Angles from Multi-beam Sonar Data
Authors: Wadhams P. , Toberg N.
Published: December 2011

We describe our work undertaken to analyse sea ice pressure ridge morphology in the Arctic ocean from Autonomous Underwater Vehicles (AUVs) and submarines. Details of cruises, from ship-based launches of large (7m) AUVs to hand deployed AUVs are given, as well as the first submarine voyage to incorporate an upward looking multibeam sonar. We discuss our techniques of recovering meaningful data from the record, and introduce our method to calculate pressure ridge slope angles, orientation and frequency. This work is done in the context of the loads that both level and deformed sea ice exert on off-shore structures.

Introduction

There are important reasons to know the three-dimensional topography of the under-ice surface. The polar sea ice cover consists of two distinct components: thermodynamic ice, which has reached its current thickness by natural growth; and deformed ice, which can attain a much greater thickness through rafting and ridging. Pressure ridges, formed by the crushing of refrozen leads, can reach a draft of more than 50 m. From the viewpoint of modeling the role of sea ice in climate, this composite nature of the ice cover must be considered in order to deal with dynamics, thermodynamics and mechanics correctly. For the offshore industry, ridging is important, as the deepest multiyear pressure ridge represents the design load on an offshore structure, while the deepest ridges also control scouring frequencies in the nearshore zone. The topography of sea ice is important for such diverse applications as calculating its containment potential for oil blowouts, its role as a substrate for a sea ice ecosystem, its impact on icebreaker design, and its scattering potential for under-ice acoustic propagation.

The first measurements of under-ice topography were simple linear profiles generated by narrow-beam upward-looking sonar. These were first obtained from naval submarines, and it was the voyage of USS "Nautilus" in 1958 which first revealed, via an upward sonar profile, the rugged topography of the ice underside with its landscape of steep pressure ridges separated by smoother undeformed floe sections (Lyon, 1961). From then on, frequent submarine transects of the Arctic Ocean in different years and seasons have enabled the regional distribution of ice topography to be determined (Bourke and Garrett, 1987) and, more recently, the rapid decline in mean ice draft throughout the Arctic to be documented (Rothrock et al., 1999, 2003, 2008; Wadhams, 1990; Wadhams and Davis, 2000, 2001; Yu et al., 2004).
Developing Treatment Products for Increased Microbial Degradation of Petroleum Oil Spills across Open-Water Surfaces
Authors: Kjeilen-Eilertsen G. , Jersak J.M. , Westerlund S.
Published: December 2011

Uncontrolled releases of free-phase petroleum to open-water surfaces, e.g. oil spills, can be contained using existing products and techniques, such as booms, sorbents etc. Biotic and abiotic remedial approaches (such as use of dispersants, formation of oil-mineral aggregates [OMA] and bioremediation "products") also exist for managing or treating spilled oil in the water or in shoreline areas, although varying effectiveness in this regard has been reported.

A two-year project (2008-2010) targeting laboratory scale development and optimization of nutrient-bearing treatment products was recently completed. The designed products, when applied to spilled oil occurring in open-water marine areas, were intended to accomplish the following objectives:promote formation of OMA with desired buoyancy characteristics, thatfacilitate increased activity of indigenous, aerobic microbial populations and thusincreased degradation rates of the bound petroleum constituents.

When successfully optimized, such treatment products potentially provide a cost-effective alternative to existing approaches for treating oil spills (e.g. dispersants or clays only), possibly also with a wider time-window for use.

Selected combinations of clay minerals, nutrients and dispersants partly capable of meeting the objectives in laboratory scale experiments were identified through the project. A range of material combinations was screened in small scale laboratory experiments, and - based on a set of criteria of which initial biodegradation of oil was the most important - some combinations were selected for further examination. Testing was primarily done using a single crude oil topped to 150°C, and incubated at 10°C. Further examination of microbial population responses and better quantification of OMA formation and increased degradation of oil in OMA formed is warranted, including product effectiveness on emulsified oil. Large-scale laboratory and field pilot testing is also recommended to document results observed at small lab scale.

The petroleum industry is moving into increasingly remote and complex locations, such as deeper waters and the Arctic. In Norway at least, this calls for improved spill contingency, and there is currently a strong focus from the authorities to improve and expand the available "toolbox" of effective treatment approaches, as has been the focus internationally for some time. The Deepwater Horizon accident and the resulting moratorium on deep-sea drilling also support the needs in this regard.
Umbilical Technology for Arctic Projects
Authors: Fogg David
Published: December 2011

This paper outlines the state of the art of subsea control umbilical technology, making reference to the requirements imposed by projects in arctic environments.

The mechanical demands on dynamic, riser umbilicals are dominated by the environmental loadings and motions of the host vessel. Common solutions for Arctic applications are often based on an FPSO (Floating Production Storage and Offloading Vessel) and require the umbilical to withstand significant bending and tensile loading due to relatively large vessel motions and disconnect scenarios. The linear weight of the umbilical and provision of moulded polymer bend stiffener devices are of prime importance. Flexibility, minimum bend radii and resistance to fatigue damage are defining properties in the ability to provide solutions.

Other considerations relevant to Arctic environments are; temperatures, compatibility with installation methods such as trenching and on-bottom stability management by designed in weight or rock dumping etc.

This paper presents solutions based on armoured thermoplastic umbilicals containing hydraulic hoses and steel tube umbilicals. The benefits and limitations of both solutions are presented and contrasted. The status of each technology is highlighted with reference to track record and previous project experience.

The conclusion of this paper is that well engineered umbilical solutions are available to meet requirements with current visibility and emphasis is on the identification of any future emerging technology gaps. The effectiveness of thermoplastic umbilicals as a solution for very dynamic requirements is supported by experience gained to date and the use of thermoplastics in very low temperature applications is further supported by ongoing development work.

Introduction

An umbilical is defined as an assembly of fluid conduits, electrical and fibre optic cables, either on their own or with combinations of each other, cabled together for flexibility. In any offshore field development, the umbilical is a critical component for the production of hydrocarbons. In the context of this paper, the term umbilical is used to refer to permanently installed subsea applications where the umbilical can provide a combination of functions.
Disconnectable Arctic Spar
Authors: Sablok Anil , Ramachandran Manoj , Kim Jang Whan
Published: December 2011

A floating platform for arctic regions is required to break ice and withstand high ice loads, be disconnected and towed away in the event of approaching icebergs, leaving the mooring lines and risers in-place, support large topsides and provide large quantities of utility storage. Additionally the platform should provide low motion response to storm and ice loads to maximize the operational uptime and enable the use of current state-of-the-art riser systems.

This paper presents the details of a Spar platform that has been configured to satisfy all requirements for Arctic operation. The paper describes a number of key features that are specifically designed to reduce ice loads on the hull and to allow ice floes to break around the hull without damaging the hull, topsides, mooring or risers, while maintaining the characteristic low motion response to storm environments. The paper also describes the system for disconnecting and reconnecting the moorings and risers in response to approaching large icebergs.

Introduction

A floating offshore production platform suited for Arctic service where sheet ice and icebergs are prevalent has to be designed to satisfy the following key requirements:Withstand high ice loads during winter without damaging the hull, topsides or the risersProvide satisfactory performance due to ice loads and storms during non-winter months to protect the risers and provide high uptime for platform operationsMaximize uptime through good operational performanceBe able to disconnect from its mooring and risers and be towed away in case of an unavoidable iceberg or an extremely large ice floe that may induce damage to the hull, topsides, mooring or risersHave large capacity to store utilities in the hull to plan for limited supply boat trips

Spar has been considered as a floating platform for Arctic application because of its superior performance and its ability to minimize the ice loads, protect the risers and display consistent response in all directions to the storm environment or ice loads. The following sections will describe the Spar system, mooring and riser configurations designed for quick disconnection and reconnection.
Evaluation of the Hydrate Deposit at the PBU L-106 Site, North Slope, Alaska, for a Long-Term Test of Gas Production
Authors: Moridis George J. , Reagan Matthew T. , Anderson-Kuzma Heidi , Zhao Yang , Boyle Katie , Rector James W.
Published: December 2011

As part of the effort to investigate the technical feasibility of gas production from hydrate deposits, a long-term field test (lasting 18–24 months) is under consideration in a project led by the U.S. Department of Energy. We evaluate a candidate deposit involving the C-Unit in the vicinity of the PBU-L106 site in North Slope, Alaska. This deposit is stratigraphically bounded by impermeable shale top and bottom boundaries (Class 3), and is characterized by high intrinsic permeabilities, high porosity, and high hydrate saturation. The C-unit deposit is composed of two hydrate-bearing strata separated by a 30-ft-thick shale interlayer, and its temperatrure across its boundaries ranges between 5 and 6.5 oC.

We investigate by means of numerical simulation the production potential of this deposit using both vertical and horizontal wells. We also explore the sensitivity of production to key parameters such as the hydrate saturation, the formation permeability and porosity, the system heterogeneity, the permeability of the bounding shale layers, and the initial temperature. The results indicate that production from horizontal wells may be orders of magnitude larger than that from vertical ones. Additionally, production increases with the formation permeability, and with a decreasing permeability of the boundaries. The effect of the hydrate saturation on production is complex and depends on the time frame of production. We show that hydrate dissociation declines very rapidly upon cessation of production, indicating that a production does not have long-term residual effects. In the same study, we investigate the potential of time-lapse seismic surveys to monitor gas production from hydrate deposits. The seismic properties, such as the elastic and shear moduli, are a function of the simulated time- and space-varying pressure and temperature, the aqueous-, gas-, and hydrate-phase saturation, and the porosity. We examine a variety of seismic measurement configurations and survey parameters to determine the optimal approach for detecting changes occurring in the hydrate deposit during production that can be used as the basis for monitoring hydrate dissociation, and the corresponding hydrate saturation and geomechanical status.

Introduction

Background.

Gas hydrates (GH) are solid crystalline compounds of water and gaseous substances that are described by the general chemical formula G•NH H2O. In the GH clathrates, the molecules of gas G (referred to as guests) occupy voids within the lattices of ice-like crystal structures. If gas and H2O availability is not a limitation, hydrate deposits can occur in two distinctly different geographic settings where the necessary conditions of low temperature T and high pressure P exist for their formation and stability: in the Arctic (typically in association with permafrost) and in deep ocean sediments (Kvenvolden, 1988).
Deepwater Arctic - Technical Challenges and Solutions
Authors: Aggarwal Rajiv , D'Souza Richard
Published: December 2011

This paper presents the alternatives available and assessment of floating platforms, stationkeeping and riser systems based on studies undertaken for Arctic fields. The industry experience with floating units for both drilling and production operations in the offshore areas subjected to ice features are discussed. The salient aspects of these systems are discussed considering the general characteristics of selected basins.

The Arctic fields developed so far are in water depths up to 125 m and have used the Gravity Based Structures and detachable FPSOs, besides other systems such as jacket platforms and islands used in shallower water. There is significant industry interest in the development of Arctic and Sub-Arctic fields in water depths beyond commercial viability of bottom founded designs. The water depths in some North American and offshore Greenland Basins are up to 2,800 m. The development of fields in deeper water would require use and adaptation of floating units and subsea systems, which have been used in many deepwater basins. However, their use in deepwater Arctic would add significant challenges from harsh weather, severe ice features (pack ice, icebergs), lack of infrastructure, remoteness, and reduced accessibility.

The floating unit designs, alternatives for sub-systems, and subsea solutions and technologies are enabling development of Arctic fields offshore Norway and Russia, such as Goliat and Shtokman in up to 350 m water depth. Floating units provide flexibility in field development and ability to detach and move the unit from the path of significant ice loading events and icebergs. These features enable improve their technical and commercial feasibility by reducing load effects and risks.

Challenges in Arctic

The development of hydrocarbon fields offshore Arctic and Sub-Arctic in the North, have gained significant importance due to potential for very large reservoirs increasing their commercial viability. Some of the important leasing areas in the Arctic or Sub-Arctic offshore identified in Fig. 1 are in deepwater and ultra-deepwater: Barent Sea, offshore Norway and Russia; Orphan Basin, offshore Newfoundland; and fields offshore Greenland and Iceland. The water depths vary from 300 m to 3,000 m in these leases and several of these fields are in exploratory drilling or in the development planning stages.
Etude de la vitesse de convergence de l'algorithme en cascade dans la construction des ondelettes d'Ingrid Daubechies
Authors: Durand Sylvain
Published: December 2011

The aim of this paper is the study of the convergence of algorithms involved in the resolution of two scale equations. They are fixed point algorithms, often called "cascade algorithm", which are used in the construction of wavelets. We study their speed of convergence in Lebesgue and Besov spaces, and show that the quality of the convergence depends on two independent factors. The first one, as we could foresee, is the regularity of the scaling function which is the solution of the equation. The second factor (that is the essential discovery of this work) concerns specific algebraic properties of the function used to initialize the algorithm. This function must satisfy conditions analogous to Strang-Fix conditions.
On the uniqueness problem for quasilinear elliptic equations involving measures
Authors: Kilpeläinen Tero , Xu Xiangsheng
Published: December 2011

We discuss the uniqueness of solutions to problems like

\lambda |u|^{s–1}u– \mathrm {div} (|\bigtriangledown u|^{p–2}= \mu \space {\mathrm {on} \space \Omega,}

u=0 \space \mathrm {in} \space {\partial \Omega,}

where

\lambda ≥ 0

and

\mu

is a signed Radon measure.
Transformée en paquets d'ondelettes des signaux stationnaires: comportement asymptotique des densités spectrales
Authors: Hervé Loïc
Published: December 2011

We consider quadrature mirror filters, and the associated wavelet packet transform. Let

X = \{X_n \} _{n \in \mathbb Z}

be a stationary signal which has a continuous spectral density,

f

. We prove that the

2^n

signals, obtained from

X

by

n

iterations of the transform, “converge” to white noises when

n \rightarrow + \infty

. If

f

is holderian, the convergence rate is exponential.
Spectral factorization of measurable rectangular matrix functions and the vector-valued Riemann problem
Authors: Rakowski Marek , Spitkovsky Ilya
Published: December 2011

We define spectral factorization in

L_p

or a generalized Wiener–Hopf factorization of a measurable singular matrix function on a simple closed rectifiable contour

\Gamma

. Such factorization has the same uniqueness properties as in the nonsingular case. We discuss basic properties of the vector valued Riemann problem whose coefficient takes singular values almost everywhere on

\Gamma

. In particular, we introduce defect numbers for this problem which agree with the usual defect numbers in the case of a nonsingular coefficient. Based on the Riemann problem, we obtain a necessary and sufficient condition for existence of a spectral factorization in

L_p

.
The boundary absolute continuity of quasiconformal mappings II
Authors: Heinonen Juha
Published: December 2011

In this paper a quite complete picture is given of the absolute continuity on the boundary of a quasiconformal map

\mathbb B^3 \rightarrow D

, where

\mathbb B^3

is the unit 3-ball and

D

is a Jordan domain in

\mathbb R^3

with boundary rectifiable in the sense of geometric measure theory. Moreover, examples are constructed for each

n≥3

, showing that quasiconformal maps from the unit

n

-ball onto Jordan domains with boundary

(n–1)

-rectifiable need not have absolutely continuous boundary values.
A theorem of Semmes and the boundary absolute continuity in all dimensions
Authors: Heinonen Juha
Published: December 2011

We use a recent theorem of Semmes to resolve some questions about the boundary absolute continuity of quasiconformal maps in space.
Elliptic gaussian random processes
Authors: Benassi Albert , Jaffard Stéphane , Roux Daniel
Published: December 2011

We study the Gaussian random fields indexed by

\mathbb R^d

whose covariance is defined in all generality as the parametrix of an elliptic pseudodifferential operator with minimal regularity assumption on the symbol. We construct new wavelet bases adapted to these operators; the decomposition of the field on this corresponding basis yields its iterated logarithm law and its uniform modulus of continuity. We also characterize the local scalings of the field in term of the properties of the principal symbol of the pseudodifferential operator. Similar results are obtained for the _Multi-Fractional Brownian Motion_.
$L^p$-bounds for spherical maximal operators on $\mathbb Z^n$
Authors: Magyar Akos
Published: December 2011

We prove analogue statements of the spherical maximal theorem of E.M. Stein for the lattice points

\mathbb Z^n

. We decompose the discrete spherical measures as an integral of Gaussian kernels

s_{t, \epsilon}(x) = e^{2\pi i|x|^2(t+i\epsilon)}

. By using Minkowski's integral inequality it is enough to prove

L^p

-bounds for the corresponding convolution operators. The proof is then based on

L^2

estimates by analysing the Fourier transforms $\hat{s}_{t,\epsilon}(\xi) which can be handled by making use of the "circle" method for exponential sums. As a corollary one obtains some regularity of the distribution of lattice points on small spherical caps.
Hilbert transform, Toeplitz operators and Hankel operators, and invariant $A_\infty$ weights
Authors: Treil Sergei , Volberg Alexander , Zheng Dechao
Published: December 2011

In this paper several sufficient conditions for boundedness of the Hilbert transform between two weighted

L^p

-spaces are obtained. Invariant

A_\infty

weights are introduced. Several characterizations of invariant

A_\infty

weights are given. We also obtain some sufficient conditions for products of two Toeplitz operators or Hankel operators to be bounded on the Hardy space of the unit circle using Orlicz spaces and Lorentz spaces.
Some generalized Coxeter groups and their orbifolds
Authors: Hagelberg Marcel , Hidalgo Rubén A.
Published: December 2011

In this note we construct examples of geometric 3-orbifolds with (orbifold) fundamental group isomorphic to a (

\mathbb Z

-extension of a) generalized Coxeter group. Some of these orbifolds have either euclidean spherical or hyperbolic structure. As an application we obtain an alternative proof of theorem 1 of Hagelberg, Maclaughlan and Rosenberg in [5]. We also obtain a similar result for generalized Coxeter groups.
The Implementation of Inclusive Education for Students with Special Needs in Indonesia
Authors: Sunardi , , Yusuf Mucawir , Gunarhadi , , Priyono , , Yeager John L.
Published: December 2011

Over the last decade, inclusion has become a world trend in special education. In response to that trend, the Indonesian government has adopted a progressive policy to implement inclusive education. The aim of this research is to describe the implementation process by focusing on the institutional management, student admission/identification/assessment, curriculum, instruction, evaluation, and external supports. The sample consisted of 186 schools with a total student body of 24,412, 12 percent of which (3,419) were students with special needs. In those schools, there were also 34 gifted students (0.1 percent). Of all the students with special education needs (SEN) students, 56 percent were males and 44 percent were females. The results showed, in terms of institutional management, that the majority of inclusive schools had developed strategic plans (for inclusion), legally appointed coordinators, involved related and relevant parties, and conducted regular coordination meetings. However, there were still many schools that had not restructured their school organizations. In terms of student admission/identification/assessment, 54 percent of schools set a quota for SEN students. Only 19 percent applied a selection process in student admission, half of which used different procedures for SEN candidates. Approximately 50 percent of inclusive schools had modified their curriculum, including a variety of standards. In terms of instruction, 68 percent of inclusive schools reported that they modified their instructional process. Only a few schools, however, provided special equipment for students with visual impairment, physical impairment, speech and hearing problems, and autism and gifted and talented students. In a student evaluation, more than 50 percent reported that test items, administration, time allocations, and students’ reports were modified. For the national exam, this number decreased dramatically. Finally, external supports in the forms of funding, coaching, and facilities were mostly provided by provincial governments and by the Directorate of Special Education.
The Central Role of Glia in Pathological Pain and the Potential of Targeting the Cannabinoid 2 Receptor for Pain Relief
Authors: Wilkerson Jenny L. , Milligan Erin D.
Published: December 2011

Under normal conditions, acute pain processing consists of well-characterized neuronal signaling events. When dysfunctional pain signaling occurs, pathological pain ensues. Glial activation and their released factors participate in the mediation of pathological pain. The use of cannabinoid compounds for pain relief is currently an area of great interest for both basic scientists and physicians. These compounds, bind mainly either the cannabinoid receptor subtype 1 (CB1R) or cannabinoid receptor subtype 2 (CB2R) and are able to modulate pain. Although cannabinoids were initially only thought to modulate pain via neuronal mechanisms within the central nervous system, strong evidence now supports that CB2R cannabinoid compounds are capable of modulating glia, (e.g. astrocytes and microglia) for pain relief. However, the mechanisms underlying cannabinoid receptor-mediated pain relief remain largely unknown. An emerging body of evidence supports that CB2R agonist compounds may prove to be powerful novel therapeutic candidates for the treatment of chronic pain.
Aspirin in Neurology
Authors: Aburto-Murrieta Yolanda , Bonifacio-Delgadillo Dulce , Marquez Juan
Published: December 2011

Aspirin is widely used for the prevention of recurrent stroke in patients with transient ischaemic attack (TIA) of arterial origin, because it is effective and inexpensive. Clopidogrel and the combination of aspirin and extended-release dipyridamole are more effective than aspirin, but are also much more expensive. No other antithrombotic regimens provide significant advantages over aspirin, although cilostazol and the novel platelet protease-activated receptor-1 antagonist, SCH 530348, are currently being evaluated.
Numerous trials have examined the efficacy of antiplatelet drugs, primarily aspirin for prevention of vascular events in patients with a prior TIA or stroke. Although many were small and inconclusive, the Antiplatelet Trialists’ Collaboration (ATC) individual patient data meta-analysis reported that among more than 23000 patients (from 21 randomized controlled trials), antiplatelet therapy (usually aspirin) compared with placebo or untreated control continued for a mean of 29 months was associated with a 22% reduction in the odds of recurrent ischemic stroke, myocardial infarction (MI), or vascular death (17.8% versus 21.4%, P=0.001).
KCNQ1OT1 hypomethylation: A Novel disguised genetic predisposition in sporadic pediatric adrenocortical tumors?
Authors: Wijnen Mark , Alders Mariëlle , Zwaan Christian M. , Wagner Anja , van den Heuvel‐Eibrink Marry M.
Published: December 2011

Pediatric adrenal tumors, other than neuroblastoma, are rare and can be associated with a genetic predisposition. In this report we describe two patients with an isolated and apparently sporadic adrenocortical tumor; one girl with a carcinoma, the other girl with an adenoma. In both patients genetic screening revealed hypomethylation of the KCNQ1OT1 gene, well‐known for its association with the Beckwith–Wiedemann syndrome. This represents a likely novel genetic predisposition in patients with adrenocortical tumors without clear phenotypic features of the Beckwith–Wiedemann syndrome. Pediatr Blood Cancer 2012;59:565–566. © 2011 Wiley Periodicals, Inc.
Preliminary experience with personalized and targeted therapy for pediatric brain tumors
Authors: Wolff Johannes E. , Brown Robert E. , Buryanek Jamie , Pfister Stefan , Vats Tribhawan S. , Rytting Michael E.
Published: December 2011

Background

A new generation of anticancer drugs has reached clinical care in common diseases, but their use in rare diseases such as pediatric brain tumors lags behind since conventional clinical trial design requires larger patient numbers.

Procedure

We designed individualized treatment protocols for pediatric patients with relapsed brain tumors, based upon the patient's treatment history. In addition, each tumor was analyzed with morphoproteomics using a panel of markers to show treatment targets, resulting in a list of potential novel drugs to be added to chemotherapy. Here, we present the concept and report the experiences of the first patients enrolled in the program.

Results

Eleven treatment protocols were designed using morphoproteomic information and given to eight patients. The histological diagnoses included: medulloblastoma (n = 3), glioblastoma multiforme (n = 2), atypical teratoid rhabdoid tumor (n = 1), choroid plexus carcinoma (n = 1), and primitive neuroectodermal tumors (n = 1). Tumor markers included p‐ERK, Topoisomerase IIa, Bcl‐2, VEGF‐A, p‐STAT3, ER‐beta, p‐mTOR, and p‐NF‐kappaBp65. The novel agents included sorafenib, bevacizumab, fulvestrant, rapamycin, bortezomib, and curcumin. The response to the first protocol was complete response: 1, partial response: 1, stable disease: 0, progressive disease: 4, and continuous complete remission: 2. The median Event‐Free Survival was 0.32 year ± 0.4. For the comparison with the institutional control group, the individual response probability was calculated. The observed response was superior to the historical controls (P = 0.006 Whitman U‐test).

Conclusion

This approach warrants further, systematic evaluation as proof of concept and then expansion to drug‐specific hypotheses. Pediatr Blood Cancer 2012; 59: 27–33. © 2011 Wiley Periodicals, Inc.
Desmoplastic small round cell tumors with EWS‐WT1 fusion transcript in children and young adults
Authors: Philippe‐Chomette Pascale , Kabbara Nabil , Andre Nicolas , Pierron Gaelle , Coulomb Aurore , Laurence Valérie , Blay Jean‐Yves , Delattre Olivier , Schleiermacher Gudrun , Orbach Daniel
Published: December 2011

Background

The presence of the EWS‐WT1 gene fusion transcript (GFT) is characteristic of desmoplastic small round cell tumor (DSRCT), a rare and very aggressive disease for which the treatment has not yet been clearly standardized.

Methods

This was a retrospective national multicenter analysis of young patients <30 years with tumors expressing the EWS‐WT1‐GFT, designed to determine whether extensive surgery had an impact on survival.

Results

Between 1995 and 2006, a EWS‐WT1‐GFT was detected in the tumors of 38 patients, 17 (44.7%) of whom had had a different initial pathologic diagnosis prior to molecular testing. Mean age was 13.2 years (range: 4–29.7 years). Only 9 patients (24%) had localized disease. Treatment was heterogeneous. Nine patients had “limited” surgical resections and 22 underwent “extensive” surgery. Two‐year event‐free survival and overall survival were 14.4% and 50%, respectively. Among the five patients who were alive in complete remission, four had undergone extensive and complete surgery.

Conclusions

Detection of the EWS‐WT1‐GFT plays a major role in the diagnosis of DSRCT. No survival difference was observed according to extent of surgery, but complete surgery seemed to offer the best chance of long‐term survival. High‐dose chemotherapy or local radiotherapy did not appear to improve survival in this retrospective analysis, but larger prospective studies are needed to provide definitive conclusions on the role of these treatments. Pediatr Blood Cancer 2012; 58: 891–897. © 2011 Wiley Periodicals, Inc.
Ventricular systolic reserve in asymptomatic children previously treated with low doses of anthracyclines: A longitudinal, prospective exercise echocardiography study
Authors: Guimaraes‐Filho Fabio V. , Tan Doralice M. , Braga Joao C. F. , Rodrigues Alexandre , Waib Paulo H. , Matsubara Beatriz B.
Published: December 2011

Background

The time course of mild cardiotoxicity induced by anthracycline remains unknown. The aim of this study was to evaluate the long‐term evolution of decreased myocardial reserve in children previously treated with a cumulative dose of anthracycline up to 100 mg/m2.

Patients and Methods

Twenty‐seven asymptomatic cancer survival patients (25 with lymphoblastic leukemia), in continuous remission and off treatment for >12 months with no alterations in conventional echocardiograms were evaluated by exercise echocardiography at 37 ± 15.4 months (T1) and 101 ± 24 months (T2) after finishing treatment (ADRIA group). This group was compared with 25 healthy individuals (control group) similar to the ADRIA group with respect to age and body surface area (BSA). All individuals underwent treadmill exercise testing according to Bruce protocol. Echocardiograms were performed before and immediately after exercise.

Results

The groups were similar regarding cardiac structure and left ventricular (LV) systolic function at rest at T1 and T2. The growth of LV posterior wall thickness related to BSA was lower in the ADRIA group at T2. Post exercise, smaller LV ejection indexes and attenuated changes in the afterload in ADRIA group were observed at T1 and T2.

Conclusion

The decreased systolic reserve induced by a low dose of anthracycline in asymptomatic children and adolescents remains unaffected over a 5‐year period, suggesting that positive outcomes in chronic cardiotoxicity would be expected in patients with mild impairment after anthracycline treatment. Pediatr Blood Cancer 2012;59:548–552. © 2011 Wiley Periodicals, Inc.
Inflammation: What role in pediatric cancer?
Authors: Morgenstern Daniel A. , Anderson John
Published: December 2011

There is growing evidence for the importance of chronic inflammation in the pathogenesis of adult cancers and for an ongoing role of the inflammatory response in tumor growth and metastasis. Here, we examine how these processes relate to pediatric malignancies. While it is unlikely that chronic inflammation plays a significant role in driving malignant progression in childhood tumors that typically have developmental origins, the inflammatory response does appear to play an important role in the development and progression of many types of childhood cancer. An enhanced understanding of these processes will be of critical importance in developing novel therapeutic strategies. Pediatr Blood Cancer 2012; 58: 659–664. © 2011 Wiley Periodicals, Inc.
Safety of central venous catheter placement at diagnosis of acute lymphoblastic leukemia in children
Authors: Gonzalez G. , Davidoff A.M. , Howard S.C. , Pui C‐H. , Rao B.N. , Shenep J. L. , Wozniak A. , Shochat S.J.
Published: December 2011

Background

Central venous catheters (CVC) facilitate the management of patients with cancer. Optimal timing for placement of a CVC is controversial. We sought to determine whether early placement in children with acute lymphoblastic leukemia (ALL), a group at high risk for infection and thrombosis, was associated with an increased rate of surgical complications.

Procedure

We evaluated the incidence and risk factors for early surgical complications in children with ALL diagnosed between 2004 and 2009 at a single pediatric cancer center.

Results

One hundred seventy‐two patients were studied. There were 17 episodes of bloodstream infection, for a 30‐day incidence of 9.8% (95% CI, 5.9–15%). There were no surgical site infections and no CVC was removed due to infection. Early thrombosis occurred in only one patient, 3 days after CVC placement. Infection was not influenced by catheter type, patient age, body mass index, or fever at the time of placement. The infection rate was not statistically higher when the ANC was <500/mm3 at the time of CVC placement (14.2% vs. 6.8%; P = 0.12).

Conclusion

Early CVC placement at the time of diagnosis of ALL was associated with a low surgical complication rate with no catheters requiring removal due to infection. Utilizing our current methods of preoperative preparation, surgical management and postoperative CVC care, early placement of a CVC is safe in children with ALL even when their ANC is <500/mm3, but larger cohort studies would be helpful to further clarify this issue. Pediatr Blood Cancer 2012; 58: 498–502. © 2011 Wiley Periodicals, Inc.
Tumor histology during induction therapy in patients with high‐risk neuroblastoma
Authors: George Rani E. , Perez‐Atayde Antonio R. , Yao Xiaopan , London Wendy B. , Shamberger Robert C. , Neuberg Donna , Diller Lisa
Published: December 2011

Background

In high‐risk neuroblastoma patients, response to induction chemotherapy is emerging as an important determinant of overall survival. We sought to determine whether histological changes in the primary tumor following induction therapy could be used as a marker of response.

Procedure

Second‐look primary tumor specimens from 43 patients were reviewed according to specific morphological features.

Results

In the majority, induction therapy resulted in a shift from an intermediate/high to low mitosis‐karyorrhexis index (MKI) (P = 0.0009) and from undifferentiated/poorly differentiated to differentiating tumors (P < 0.0001). Following induction therapy, persistence of intermediate/high tumor MKI and ≥90% persistent neuroblastic cells were predictive of a poor outcome (P = 0.001 and 0.03, respectively). Less than 10% tumor necrosis was associated with a trend towards lower survival.

Conclusions

High proliferative activity in the primary tumor following induction therapy portends a poor outcome in patients with high‐risk neuroblastoma. If confirmed in a larger cohort, tumor histology at second‐look surgery could be used to define a subset of very high risk patients who would benefit from alternative therapies prior to myeloablative dose‐intensive transplant. Pediatr Blood Cancer 2012;59:506–510. © 2011 Wiley Periodicals, Inc.
The limited screening value of insulin‐like growth factor‐i as a marker for alterations in body composition in very long‐term adult survivors of childhood cancer
Authors: Blijdorp Karin , van den Heuvel‐Eibrink Marry , Pieters Rob , Boot Annemieke , Sluimer Johanna , van der Lelij Aart‐Jan , Neggers Sebastian
Published: December 2011

Background

The clinical relevance of low IGF‐I levels, caused by cranial radiotherapy, in adult childhood cancer survivors has not been studied extensively. We evaluated whether IGF‐I is a useful marker for altered body composition and growth hormone deficiency (GHD) in this group.

Procedure

We analyzed retrospective data from 610 adult childhood cancer survivors, retrieved from the late effects clinic. Median age at diagnosis was 6 years (interquartile range 3–11) and follow‐up time was 18 years (13–24). We assessed IGF‐I standard deviation scores (SDS), anthropometrical measures, growth hormone stimulation tests in patients with clinical signs of GHD, and measures of body composition (assessed by dual X‐ray absorptiometry, Lunar Prodigy).

Results

In 58 cranially irradiated acute leukemia survivors (25 Gy (24–25)) and 56 locally irradiated brain tumor survivors (42 Gy (35–54)) we found significantly lower IGF‐I SDS (P < 0.001), lower height SDS (P < 0.001), higher body mass index (P = 0.01), higher waist–hip ratio (WHR; P = 0.001), higher total fat percentage SDS (P < 0.001), and lower lean body mass SDS (P < 0.001), as compared to 452 not cranially irradiated survivors. IGF‐I showed a weak inverse correlation with BMI (r = − 0.12, P = 0.04), WHR (r = − 0.15, P = 0.01), total fat percentage (r = − 0.14, P = 0.02), and a positive correlation with lean body mass (r = 0.15, P = 0.01). In patients with low IGF‐I levels, IGF‐I did not significantly differ between subjects with and without GHD as determined by GH‐stimulation testing (P = 0.39).

Conclusion

This study shows that IGF‐I has limited value as a marker for alterations in body composition in adult childhood cancer survivors. Pediatr Blood Cancer 2012;59:711–716. © 2011 Wiley Periodicals, Inc.
Distance‐dependent atomic knowledge‐based force in protein fold recognition
Authors: Mirzaie Mehdi , Sadeghi Mehdi
Published: December 2011

We have recently introduced a novel model for discriminating the correctly folded proteins from well‐designed decoy structures using mechanical interatomic forces. In the model, we considered a protein as a collection of springs and the force imposed to each atom was calculated by using the relation between the potential energy and the force. A mean force potential function is obtained from statistical contact preferences within the known protein structures. In this article, the interatomic forces are calculated by numerical derivation of the potential function. For assessing the knowledge‐based force function we consider an optimal structure and define a score function on the 3D structure of a protein. We compare the force imposed to each atom of a protein with the corresponding atom in the optimum structure. Afterwards we assign larger scores to those atoms with the lower forces. The total score is the sum of partial scores of atoms. The optimal structure is assumed to be the one with the highest score in the dataset. Finally, several decoy sets are applied in order to evaluate the performance of our model. Proteins 2012. © 2012 Wiley Periodicals, Inc.
Role of peroxisomes in the biosynthesis and secretion of β-lactams and other secondary metabolites
Authors: Martín Juan-Francisco , Ullán Ricardo V , García-Estrada Carlos
Published: December 2011

Peroxisomes are eukaryotic organelles surrounded by a single bilayer membrane, containing a variety of proteins depending on the organism; they mainly perform degradation reactions of toxic metabolites (detoxification), catabolism of linear and branched-chain fatty acids, and removal of H2O2 (formed in some oxidative processes) by catalase. Proteins named peroxins are involved in recruiting, transporting, and introducing the peroxisomal matrix proteins into the peroxisomes. The matrix proteins contain the peroxisomal targeting signals PTS1 and/or PTS2 that are recognized by the peroxins Pex5 and Pex7, respectively. Initial evidence indicated that the penicillin biosynthetic enzyme isopenicillin N acyltransferase (IAT) of Penicillium chrysogenum is located inside peroxisomes. There is now solid evidence (based on electron microscopy and/or biochemical data) confirming that IAT and the phenylacetic acid- and fatty acid-activating enzymes are also located in peroxisomes. Similarly, the Acremonium chrysogenum CefD1 and CefD2 proteins that perform the central reactions (activation and epimerization of isopenicillin N) of the cephalosporin pathway are targeted to peroxisomes. Growing evidence supports the conclusion that some enzymes involved in the biosynthesis of mycotoxins (e.g., AK-toxin), and the biosynthesis of signaling molecules in plants (e.g., jasmonic acid or auxins) occur in peroxisomes. The high concentration of substrates (in many cases toxic to the cytoplasm) and enzymes inside the peroxisomes allows efficient synthesis of metabolites with interesting biological or pharmacological activities. This compartmentalization poses additional challenges to the cell due to the need to import the substrates into the peroxisomes and to export the final products; the transporters involved in these processes are still very poorly known. This article focuses on new aspects of the metabolic processes occurring in peroxisomes, namely the degradation and detoxification processes that lead to the biosynthesis and secretion of secondary metabolites.
Influence of growth manner on nitrifying bacterial communities and nitrification kinetics in three lab-scale bioreactors
Authors: Wang Feng , Liu Yi , Wang Jinghan , Zhang Yalei , Yang Haizhen
Published: December 2011

The effects of growth type, including attached growth, suspended growth, and combined growth, on the characteristics of communities of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were studied in three lab-scale Anaerobic/Anoxicm-Oxicn (AmOn) systems. These systems amplified activated sludge, biofilms, and a mixture of activated sludge and biofilm (AS-BF). Identical inocula were adopted to analyze the selective effects of mixed growth patterns on nitrifying bacteria. Fluctuations in the concentration of nitrifying bacteria over the 120 days of system operation were analyzed, as was the composition of nitrifying bacterial community in the stabilized stage. Analysis was conducted using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR. According to the DGGE patterns, the primary AOB lineages were Nitrosomonas europaea (six sequences), Nitrosomonas oligotropha (two sequences), and Nitrosospira (one sequence). The primary subclass of NOB community was Nitrospira, in which all identified sequences belonged to Nitrospira moscoviensis (14 sequences). Nitrobacter consisted of two lineages, namely Nitrobacter vulgaris (three sequences) and Nitrobacter alkalicus (two sequences). Under identical operating conditions, the composition of nitrifying bacterial communities in the AS-BF system demonstrated significant differences from those in the activated sludge system and those in the biofilm system. Major varieties included several new, dominant bacterial sequences in the AS-BF system, such as N. europaea and Nitrosospira and a higher concentration of AOB relative to the activated sludge system. However, no similar differences were discovered for the concentration of the NOB population. A kinetic study of nitrification demonstrated a higher maximum specific growth rate of mixed sludge and a lower half-saturation constant of mixed biofilm, indicating that the AS-BF system maintained relatively good nitrifying ability.
A Search for Ecofriendly Detergent/Dispersant Additives for Vegetable‐Oil Based Lubricants
Authors: Singh Arun K. , Singh Raj K.
Published: December 2011

Carbonaceous deposits in automotive engines are the major problems associated with oil aging. Efficient detergents and dispersants have been used for several decades to solve this problem particularly in petroleum oils. But future lubricants and new engine hardware require development of new nontoxic detergent/dispersant additive technologies. Environmental concerns limit the formulation of the future lubricants. It requires not only the base oil to be ecofriendly but the additives also. In the present work, some of the potential ecofriendly chemical's molecules were identified. Specific detergents applications along with effects of chemical modifications were evaluated by Blotters Spot and Panel Coker Tests. Among the studied compounds, the PIB (polyisobutylene) succinimides are showing promising results at lower temperature, while at higher temperature piperazine derivatives citrate and oleate have the best potential to be develop as ecofriendly detergent/dispersant additives.
N‐Acyl Taurines are Anti‐Proliferative in Prostate Cancer Cells
Authors: Chatzakos Vicky , Slätis Katharina , Djureinovic Tatjana , Helleday Thomas , Hunt Mary C.
Published: December 2011

Endocannabinoids have been implicated in cancer development and cause heterogenous effects in tumor cells, by inducing apoptosis, reducing migration, causing anti‐angiogenic activity and alterations in the cell cycle resulting in growth arrest. Recently, several novel amides of fatty acids that are structurally related to endocannabinoids have been isolated from mammalian sources, although the functions of these fatty amides are not well studied. One group of these novel fatty acid amides are the N‐acyl taurines (fatty acids conjugated to the amino acid taurine). This study examined if N‐acyl taurines, specifically N‐arachidonoyl taurine and N‐oleoyl taurine could function in a similar way to endocannabinoids and result in cell cycle alterations or growth arrest in the human prostate adenocarcinoma cell line PC‐3. PC‐3 cells were treated with various concentrations of N‐arachidonoyl taurine and N‐oleoyl taurine and cell proliferation and viability was measured using resazurin and colony formation assays. Effects of N‐acyl taurines on the cell cycle was measured using FACS analysis. Treatment with N‐arachidonoyl taurine and N‐oleoyl taurine resulted in a significant reduction in proliferation of PC‐3 cells, even at concentrations as low as 1 μM. Treatment with N‐oleoyl taurine resulted in an increased number of cells in the subG1 population, suggesting apoptosis, and a lower number of cells in S‐phase of the cell cycle. In summary, our results show that novel biologically active lipids, the N‐acyl taurines, result in reduced proliferation in PC‐3 cells.