bluuebunny/crossref_metadata_2025 huggingface dataset:
Nontriggered MRI quantification of aortic pulse‐wave velocity
Authors: Langham Michael C. , Li Cheng , Magland Jeremy F. , Wehrli Felix W.
Published: September 2010

Pulse‐wave velocity is an index of arterial stiffness, which is a strong indicator of cardiovascular risk. We present a high‐speed technique that generates time‐resolved complex difference signal intensity simultaneously in the ascending and descending aorta from velocity‐encoded projections without gating, allowing quantification of pulse‐wave velocity. The velocity‐time curve was approximated with a time‐resolved complex difference signal intensity to estimate the propagation time of the pulse wave in the aortic arch. The path length of the pulse wave is measured from an oblique sagittal image in a plane encompassing thoracic ascending and descending aorta, and pulse‐wave velocity is computed from the ratio between the path length and pulse‐wave propagation time. The method was implemented at 1.5 T and 3 T, and pulse‐wave velocity was quantified in healthy subjects (ages 20–70 years, N = 23) without symptoms or prior history of cardiovascular events. In addition, the method was compared against retrospectively EKG‐gated PC‐MRI. The overall results were found to be in good agreement with literature data showing age‐related increase in aortic stiffness. The RMS differences between the projection and gated PC‐MRI methods were less than 4%. Key benefits of the proposed method are simplicity in both data acquisition and processing requiring only computation of the complex difference between the velocity‐encoded projections rather than absolute velocity. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Reference values for the nocturnal bladder capacity index
Authors: Burton Claire , Weiss Jeffrey P. , Parsons Matthew , Blaivas Jerry G. , Coats Alfred C.
Published: September 2010

Aims

The Nocturnal Bladder Capacity Index (NBCi) has been reported to be useful in distinguishing between nocturia caused by low bladder capacity and nocturnal polyuria. This paper aims to calculate reference values for NBCi from an asymptomatic population by comparing these with NBCi values from patients with lower urinary tract symptoms (LUTS) to obtain an indication of the sensitivity with which the NBCi detects low nocturnal bladder capacity. This paper also compares the sensitivity of rounded and unrounded calculations of NBCi.

Methods

Computer processed 3‐day bladder diaries from 253 asymptomatic volunteers and 184 female patients with LUTS were analyzed. NBCi values were calculated from each diary using rounded and unrounded formulae. 90th and 95th centile NBCi cutoff values were obtained from frequency distributions.

Results

NBCi reference values from the asymptomatic group were 1.1 (unrounded) and 0.7 (rounded) for 90th centile, and 1.3 (unrounded) and 1.0 (rounded) for 95th centile. The use of the rounded formula gave identical NBCi values despite a large variation in Vn/Vmax ratios whereas unrounded NBCis varied continuously with Vn/Vmax ratios. The unrounded formula found significantly more elevated NBCis in the patient group.

Conclusion

We suggest that an unrounded NBCi of 1.3 be considered a cutoff point above which reduced nocturnal bladder capacity should be investigated as a cause of nocturia. Rounding the NBCi lead to an underestimation of elevated values in a population of female patients with LUTS. Neurourol. Urodynam. 30:52–57, 2011. © 2010 Wiley‐Liss, Inc.
Twenty‐five pitfalls in the analysis of diffusion MRI data
Authors: Jones Derek K. , Cercignani Mara
Published: September 2010

Obtaining reliable data and drawing meaningful and robust inferences from diffusion MRI can be challenging and is subject to many pitfalls. The process of quantifying diffusion indices and eventually comparing them between groups of subjects and/or correlating them with other parameters starts at the acquisition of the raw data, followed by a long pipeline of image processing steps. Each one of these steps is susceptible to sources of bias, which may not only limit the accuracy and precision, but can lead to substantial errors. This article provides a detailed review of the steps along the analysis pipeline and their associated pitfalls. These are grouped into 1 pre‐processing of data; 2 estimation of the tensor; 3 derivation of voxelwise quantitative parameters; 4 strategies for extracting quantitative parameters; and finally 5 intra‐subject and inter‐subject comparison, including region of interest, histogram, tract‐specific and voxel‐based analyses. The article covers important aspects of diffusion MRI analysis, such as motion correction, susceptibility and eddy current distortion correction, model fitting, region of interest placement, histogram and voxel‐based analysis. We have assembled 25 pitfalls (several previously unreported) into a single article, which should serve as a useful reference for those embarking on new diffusion MRI‐based studies, and as a check for those who may already be running studies but may have overlooked some important confounds. While some of these problems are well known to diffusion experts, they might not be to other researchers wishing to undertake a clinical study based on diffusion MRI. Copyright © 2010 John Wiley & Sons, Ltd.
Mapping brain anatomical connectivity using white matter tractography
Authors: Lazar Mariana
Published: September 2010

Integration of the neural processes in the human brain is realized through interconnections that exist between different neural centers. These interconnections take place through white matter pathways. White matter tractography is currently the only available technique for the reconstruction of the anatomical connectivity in the human brain noninvasively andin vivo. The trajectory and terminations of white matter pathways are estimated from local orientations of nerve bundles. These orientations are obtained using measurements of water diffusion in the brain. In this article, the techniques for estimating fiber directions from diffusion measurements in the human brain are reviewed. Methods of white matter tractography are described, together with the current limitations of the technique, including sensitivity to image noise and partial voluming. The applications of white matter tractography to the topographical characterization of the white matter connections and the segmentation of specific white matter pathways, and corresponding functional units of gray matter, are discussed. In this context, the potential impact of white matter tractography in mapping the functional systems and subsystems in the human brain, and their interrelations, is described. Finally, the applications of white matter tractography to the study of brain disorders, including fiber tract localization in brains affected by tumors and the identification of impaired connectivity routes in neurologic and neuropsychiatric diseases, are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Effective medium theory of a diffusion‐weighted signal
Authors: Novikov Dmitry S. , Kiselev Valerij G.
Published: September 2010

Living tissues and other heterogeneous media generally consist of structural units with different diffusion coefficients and NMR properties. These blocks, such as cells or clusters of cells, can be much smaller than the imaging voxel, and are often comparable with the diffusion length. We have developed a general approach to quantify the medium heterogeneity when it is much finer than the sample size or the imaging resolution. The approach is based on the treatment of the medium statistically in terms of the correlation functions of the local parameters. The diffusion‐weighted signal is explicity found for the case in which the local diffusivity varies in space, in the lowest order in the diffusivity variance. We demonstrate how the correlation length and the variance of the local diffusivity contribute to the time‐dependent diffusion coefficient and the time‐dependent kurtosis. Our results are corroborated by Monte Carlo simulations of diffusion in a two‐dimensional heterogeneous medium. Copyright © 2010 John Wiley & Sons, Ltd.
An adaptive, multilevel scheme for the implicit solution of three‐dimensional phase‐field equations
Authors: Green J.R. , Jimack P.K. , Mullis A.M. , Rosam J.
Published: September 2010

Phase‐field models, consisting of a set of highly nonlinear coupled parabolic partial differential equations, are widely used for the simulation of a range of solidification phenomena. This article focuses on the numerical solution of one such model, representing anisotropic solidification in three space dimensions. The main contribution of the work is to propose a solution strategy that combines hierarchical mesh adaptivity with implicit time integration and the use of a nonlinear multigrid solver at each step. This strategy is implemented in a general software framework that permits parallel computation in a natural manner. Results are presented that provide both qualitative and quantitative justifications for these choices.© 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
The approximation of planar curve evolutions by stable fully implicit finite element schemes that equidistribute
Authors: Barrett John W. , Garcke Harald , Nürnberg Robert
Published: September 2010

On the basis of our previous work, we introduce novel fully discrete, fully practical parametric finite element approximations for geometric evolution equations of curves in the plane. The fully implicit approximations are unconditionally stable and intrinsically equidistribute the vertices at each time level. We present iterative solution methods for the systems of nonlinear equations arising at each time level and present several numerical results. The ideas easily generalize to the evolution of curve networks and to anisotropic surface energies. © 2010 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
The challenges and opportunities of implementing the integrity pact as a strategy for combating corruption in Nigeria's oil rich Niger Delta region
Authors: Idemudia Uwafiokun , Cragg Wesley , Best Bronwyn
Published: September 2010

In recent years, significant local and transnational concerted initiatives have been instituted to curb the incidence of corruption that has undermined socio‐economic development in Nigeria. Drawing on the critiques of such initiatives, and the experience from the process of implementing the Integrity Pact in the Niger Delta Development Commission, this article suggests that the Integrity Pact in principle offers real opportunities that can both reinforce and complement existing anti‐corruption initiatives in Nigeria's public sector. However, political instability, lack of continuity in civil service leadership and limited capacity are core challenges that confront the successful implementation and institutionalisation of the Integrity Pact as a means of fighting corruption and meeting sustainable development objectives in the Niger Delta. The article concludes by considering the implications of the findings for the fight against corruption in Nigeria. Copyright © 2010 John Wiley & Sons, Ltd.
KRAS and BRAF: drug targets and predictive biomarkers
Authors: Vakiani Efsevia , Solit David B
Published: September 2010

Three decades have passed since RAS was first identified as the transformative factor in the Harvey and Kirsten strains of the mouse sarcoma virus. RAS and several of its downstream effectors, including BRAF, have since been shown to be commonly mutated in broad range of human cancers and biological studies have confirmed that RAS pathway activation promotes tumour initiation, progression and metastatic spread in many contexts. With the identification of RAS mutation as a strong predictor of clinical resistance to EGFR‐targeted therapies, RAS mutational testing has been incorporated into the routine clinical care of patients with colorectal and lung cancers. This article reviews the current understanding of RAS signalling as it relates to cancer biology, current efforts to develop inhibitors of RAS and its key downstream effectors and the technical challenges of RAS mutational testing in the clinical setting. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Leadership Substitutes and Personality Impact on Time and Quality in Virtual New Product Development Projects
Authors: Strang Kenneth David
Published: September 2010

Leadership, personality, and organizational factors were analyzed to measure their combined effect on virtual-based product development time and scope-quality performance. Over 1,000 team members were surveyed. MANCOVA was used to test if leadership, personality project, and/or organizational factors impacted performance. All realistic factors were included to detect leadership substitutes moderation, mediation, and prediction. Bias was reduced by not surveying leaders, by using reverse item coding, and by checking social desirability. Experimental control and common method variance were managed by including multilevel and multisource data. Performance was objectively computed from organizational data. The findings were that transactional leadership (not transformational) and some personality attributes (leader substitutes) were significant factors, increasing project scope quality and time performance.
Improving adhesion of acrylic waterborne PSAs to low surface energy materials: Introduction of stearyl acrylate
Authors: Agirre Amaia , Nase Julia , Degrandi Elise , Creton Costantino , Asua José M.
Published: September 2010

The effect of incorporating stearyl acrylate (SA) in the polymer backbone of a pressure sensitive adhesive on its adhesion properties on low energy surfaces was investigated. The presence of SA did not affect the polymer microstructure (sol molecular weight, gel, and network density) but affected the compatibility with the low energy substrate and the elasticity of the adhesive. The combination of these effects resulted in an optimum SA content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Universal xanthate‐mediated controlled free radical polymerizations of the “less activated” vinyl monomers
Authors: Yan Yuefang , Zhang Wei , Qiu Yansheng , Zhang Zhengbiao , Zhu Jian , Cheng Zhenping , Zhang Weidong , Zhu Xiulin
Published: September 2010

The living free radical polymerizations of three “less activated” monomers (LAMs), vinyl acetate, N‐vinylcarbazole, and N‐vinylpyrrolidone, were successfully achieved in the presence of a disulfide, isopropylxanthic disulfide (DIP), using 2,2′‐azoisobutyronitrile (AIBN) as the initiator. The living behaviors of polymerizations of LAMs are evidenced by first‐order kinetic plots and linear increase of molecular weights (Mns) of the polymers with monomer conversions, while keeping the relatively low molecular weight distributions, respectively. The effects of reaction temperatures and molar ratios of components on the polymerization were also investigated in detail. The polymerization proceeded with macromolecular design via interchange of xanthate process, where xanthate formed in situ from reaction of AIBN and DIP. The architectures of the polymers obtained were characterized by GPC, 1H NMR, UV–vis, and MALDI‐TOF‐MS spectra, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Structurally distinct toxicity inhibitors bind at common loci on β‐amyloid fibril
Authors: Keshet Ben , Gray Jeffrey J. , Good Theresa A.
Published: September 2010

The accumulation of aggregated β‐Amyloid (Aβ) in the brain is a hallmark of Alzheimer's disease and is thought to play a role in the neurotoxicity associated with the disease. The mechanism by which Aβ aggregates induce toxicity is uncertain. Nonetheless, several small molecules have been found to interact with Aβ fibrils and to prevent their toxicity. In this paper we studied the binding of these known toxicity inhibitors to Aβ fibrils, as a means to explore surfaces or loci on Aβ aggregates that may be significant in the mechanism of action of these inhibitors. We believe knowledge of these binding loci will provide insight into surfaces on the Aβ fibrils important in Aβ biological activity. The program DOCK was used to computationally dock the inhibitors to an Aβ fibril. The inhibitors docked at two shared binding loci, near Lys28 and at the C‐termini near Asn27 and Val39. The docking predictions were experimentally verified using lysine specific chemical modifications and Aβ fibrils mutated at Asn27. We found that both Congo red and Myricetin, despite being structurally different, bound at the same two sites. Additionally, our data suggests that three additional Aβ toxicity inhibitors may also bind in one of the sites. Identification of these common binding loci provides targets on the Aβ fibril surface that can be tested in the future for their role in Aβ biological activity.
Interaction between single‐walled carbon nanotubes and alkyl‐polyglycerol derivatives
Authors: Setaro Antonio , Popeney Chris S. , Trappmann Britta , Haag Rainer , Reich Stephanie
Published: September 2010

We use three alkyl‐polyglycerol derivatives to suspend single‐walled carbon nanotubes. The molecules differ by the aromatic moieties between the alkyl tail and the polyglycerol head. The suspended nanotubes are analysed by photoluminescence spectroscopy. We observe a dependence of the luminescence intensity and hence nanotube abundance on the aromatic moieties. Interestingly, the strength of interaction depends on the nanotube families.

magnified image

Molecular sketch of the studied surfactants.
Honeydew honey as a potent antibacterial agent in eradication of multi‐drug resistant Stenotrophomonas maltophilia isolates from cancer patients
Authors: Majtan Juraj , Majtanova Lubica , Bohova Jana , Majtan Viktor
Published: September 2010

Multi‐drug resistance in nosocomial pathogens is a continually evolving and alarming problem in health care units. Since ancient times, honey has been used successfully for the treatment of a broad spectrum of infections with no risk of resistance development.

This study investigated the antibacterial activity of two natural honeys, namely honeydew and manuka, against 20 nosocomial multi‐drug resistant Stenotrophomonas maltophilia (S. maltophilia) isolates from cancer patients. An antibiotic susceptibility test was carried out using the disk diffusion method with 20 antibiotic disks. The antibacterial activity of honey was determined using a broth dilution method. The concentration of honey used in the study was within the range of 3.75% to 25% (w/v). All 20 clinical isolates were multi‐drug resistant against 11 to 19 antibiotics. The MICs for honeydew honey ranged from 6.25% to 17.5%, while those for active manuka honey ranged from 7.5% to 22.5%. Honeydew honey had lower MICs than manuka honey against 16 of the tested isolates.

This study showed that Slovak honeydew honey has exceptional antibacterial activity against multi‐drug resistant S. maltophilia isolates and was more efficient than manuka honey (UMF 15+). Honeydew honey with strong antibacterial activity could be used as a potential agent to eradicate multi‐drug resistant clinical isolates. Copyright © 2010 John Wiley & Sons, Ltd.
The Autonomous Maritime Navigation (AMN) project: Field tests, autonomous and cooperative behaviors, data fusion, sensors, and vehicles
Authors: Elkins Les , Sellers Drew , Monach W. Reynolds
Published: September 2010

Many small boat operations can be considered in the categories of “dull, dirty, or dangerous” jobs that are appropriate for automation. Dull jobs include long‐range missions or surveillance tasks that can cause physical or mental fatigue in the crew. In addition, operational considerations may limit a human operator's time, such as exposure to heat or cold or union rules on maximum hours per day or job. The marine environment can be a dirty one as well, with wind‐driven salt spray damaging unprotected eyes. And military operations such as riverine patrol or interception of potentially hostile craft can be dangerous for a human crew. Robotic systems allowing autonomous small boat operations can be a good match by providing rugged systems that keep sailors out of harm's way and also display “digital acuity” in that their sensors will be as efficient in their first hour of patrolling as in their last. This paper describes work done to build and test an autonomy system allowing several different boats to perform significant missions both by themselves and in cooperative modes. © 2010 Wiley Periodicals, Inc.
Local resilience of almost spanning trees in random graphs
Authors: Balogh József , Csaba Béla , Samotij Wojciech
Published: September 2010

We prove that for fixed integer D and positive reals α and γ, there exists a constant C0 such that for all p satisfying p(n) ≥ C0/n, the random graph G(n,p) asymptotically almost surely contains a copy of every tree with maximum degree at most D and at most (1 ‐ α)n vertices, even after we delete a (1/2 ‐ γ)‐fraction of the edges incident to each vertex. The proof uses Szemerédi's regularity lemma for sparse graphs and a bipartite variant of the theorem of Friedman and Pippenger on embedding bounded degree trees into expanding graphs. © 2010 Wiley Periodicals, Inc. Random Struct. Alg., 2011
Retrieval of a Metabolite from Cells with Polyelectrolyte Microcapsules
Authors: Studer Deborah , Palankar Raghavendra , Bédard Matthieu , Winterhalter Mathias , Springer Sebastian
Published: September 2010

To monitor cellular processes in individual cells, it is important to measure the concentrations of intracellular metabolites and to retrieve them for analysis. The use of functionalized polyelectrolyte microcapsules as intracellular sensors for in vivo reporting is persented. Capsules loaded with streptavidin–rhodamine, which was introduced into fibroblasts by electroporation, autonomously escaped from an endocytic compartment and efficiently recruited biotin–fluorescein from the cytosol. This work demonstrates the utility of polyelectrolyte microcapsules for intracellular capture of metabolites and eventually for drug delivery on an organismic level.
Mesenchymal Stem Cell-Dependent Formation of Heterotopic Tendon-Bone Insertions (Osteotendinous Junctions)
Authors: Shahab-Osterloh Sandra , Witte Frank , Hoffmann Andrea , Winkel Andreas , Laggies Sandra , Neumann Berit , Seiffart Virginia , Lindenmaier Werner , Gruber Achim D. , Ringe Jochen , Häupl Thomas , Thorey Fritz , Willbold Elmar , Corbeau Pierre , Gross Gerhard
Published: September 2010

Ligament-to-bone and tendon-to-bone interfaces (entheses, osteotendinous junctions [OTJs]) serve to dissipate stress between soft tissue and bone. Surgical reconstruction of these interfaces is an issue of considerable importance as they are prone to injury and the integration of bone and tendon/ligament is in general not satisfactory. We report here the stem cell-dependent spontaneous formation of fibrocartilaginous and fibrous entheses in heterotopic locations of the mouse if progenitors possess a tenogenic and osteo-/chondrogenic capacity. This study followed the hypothesis that enhanced Bone Morphogenetic Protein (BMP)-signaling in adult mesenchymal stem cells that are induced for tendon formation may overcome the tendon-inherent interference with bone formation and may thus allow the stem cell-dependent formation of tendon-bone interfaces. The tenogenic and osteo-/chondrogenic competence was mediated by the adeno- and/or lentiviral expression of the biologically active Smad8 signaling mediator (Smad8ca) and of Bone Morphogenetic Protein 2 (BMP2). Modified mesenchymal progenitors were implanted in subcutaneous or intramuscular sites of the mouse. The stem cell-dependent enthesis formation was characterized histologically by immunohistological approaches and by in situ hybridization. Transplantation of modified murine stem cells resulted in the formation of tendinous and osseous structures exhibiting fibrocartilage-type OTJs, while, in contrast, the viral modification of primary human bone marrow-derived mesenchymal stromal/stem cells showed evidence of fibrous tendon-bone interface formation. Moreover, it could be demonstrated that Smad8ca expression alone was sufficient for the formation of tendon/ligament-like structures. These findings may contribute to the establishment of stem cell-dependent regenerative therapies involving tendon/ligaments and to the improvement of the insertion of tendon grafts at bony attachment sites, eventually.
Opposing Putative Roles for Canonical and Noncanonical NFκB Signaling on the Survival, Proliferation, and Differentiation Potential of Human Embryonic Stem Cells
Authors: Yang Chunbo , Atkinson Stuart P. , Vilella Felipe , Lloret Maria , Armstrong Lyle , Mann Derek A. , Lako Majlinda
Published: September 2010

The canonical and noncanonical NFκB signaling pathways regulate a variety of cellular activities; however, their functions in human embryonic stem cells (hESCs) have not been fully investigated. Expression studies during hESC differentiation indicated a significant increase in the expression of two key components of the canonical NFκB pathway (p50 and Ser529 phosphorylated form of p65) as well as a significant reduction in expression of key components of the noncanonical NFκB pathway [v-rel reticuloendotheliosis viral oncogene homolog B (RELB), p52, NIK]. Inhibition of canonical NFκB resulted in hESC apoptosis, changes in cell cycle distribution, and reduced hESC proliferation. In addition, inhibition of canonical NFκB was associated with significant changes in NANOG and OCT4 expression, suppression of differentiation toward all primitive extraembryonic and embryonic lineages with the exception of primitive ectoderm and ectodermal lineages. Inhibition of noncanonical NFκB via small interfering RNA-mediated downregulation of RELB resulted in reduced hESC proliferation and opposite changes to expression of key differentiation lineage markers genes when compared with downregulation of canonical NF-κB. Chromatin immunoprecipitation assays indicated binding of p65 and RELB to regulatory regions of key differentiation marker genes suggesting a direct transcriptional role for both branches of this pathway in hESC. These findings coupled with opposing trends in expression of key components during hESC differentiation, suggests a fine and opposing balance between the two branches of NFκB signaling pathways and their involvement in two distinct processes: the canonical pathway regulating hESC differentiation and the noncanonical pathway maintaining hESC pluripotency.
Memory in Induced Pluripotent Stem Cells: Reprogrammed Human Retinal-Pigmented Epithelial Cells Show Tendency for Spontaneous Redifferentiation
Authors: Hu Qirui , Friedrich Amy M. , Johnson Lincoln V. , Clegg Dennis O.
Published: September 2010

Induced pluripotent stem (iPS) cells have been generated from a variety of somatic cell types via introduction of transcription factors that mediate pluripotency. However, it is unknown that all cell types can be reprogrammed and whether the origin of the parental cell ultimately determines the behavior of the resultant iPS cell line. We sought to determine whether human retinal-pigmented epithelial (RPE) cells could be reprogrammed, and to test the hypothesis that reprogrammed cells retain a “memory” of their origin in terms of propensity for differentiation. We reprogrammed primary fetal RPE cells via lentiviral expression of OCT4, SOX2, LIN28, and Nanog. The iPS cell lines derived from RPE exhibited morphologies similar to human embryonic stem cells and other iPS cell lines, expressed stem cell markers, and formed teratomas-containing derivatives of all three germ layers. To test whether these iPS cells retained epigenetic imprints from the parental RPE cells, we analyzed their propensity for spontaneous differentiation back into RPE after removal of FGF2. We found that some, but not all, iPS lines exhibited a marked preference for redifferentiation into RPE. Our results show that RPE cells can be reprogrammed to pluripotency, and suggest that they often retain a memory of their previous state of differentiation.
Cardiospheres Recapitulate a Niche-Like Microenvironment Rich in Stemness and Cell-Matrix Interactions, Rationalizing Their Enhanced Functional Potency for Myocardial Repair
Authors: Li Tao-Sheng , Cheng Ke , Lee Shuo-Tsan , Matsushita Satoshi , Davis Darryl , Malliaras Konstantinos , Zhang Yiqiang , Matsushita Noriko , Smith Rachel Ruckdeschel , Marbán Eduardo
Published: September 2010

Cardiac stem cells (CSCs) are promising candidates for use in myocardial regenerative therapy. We test the hypothesis that growing cardiac-derived cells as three-dimensional cardiospheres may recapitulate a stem cell niche-like microenvironment, favoring cell survival and enhancing functional benefit after transplantation into the injured heart. CSCs and supporting cells from human endomyocardial biopsies were grown as cardiospheres and compared with cells cultured under traditional monolayer condition or dissociated from cardiospheres. Cardiospheres self-assembled into stem cell niche-like structures in vitro in suspension culture, while exhibiting greater proportions of c-kit+ cells and upregulated expression of SOX2 and Nanog. Pathway-focused polymerase chain reaction (PCR) array, quantitative real-time PCR, and immunostaining revealed enhanced expression of stem cell-relevant factors and adhesion/extracellular-matrix molecules (ECM) in cardiospheres including IGF-1, histone deacetylase 2 (HDAC2), Tert, integrin-α2, laminin-β1, and matrix metalloproteinases (MMPs). Implantation of cardiospheres in severe combined immunodeficiency (SCID) mouse hearts with acute infarction disproportionately improved cell engraftment and myocardial function, relative to monolayer-cultured cells. Dissociation of cardiospheres into single cells decreased the expression of ECM and adhesion molecules and undermined resistance to oxidative stress, negating the improved cell engraftment and functional benefit in vivo. Growth of cardiac-derived cells as cardiospheres mimics stem cell niche properties with enhanced “stemness” and expression of ECM and adhesion molecules. These changes underlie an increase in cell survival and more potent augmentation of global function following implantation into the infarcted heart.
Orthogonal array experiment in systems engineering and architecting
Authors: Huynh Thomas V.
Published: September 2010

This paper espouses the application of orthogonal array experiment to solve a class of engineering optimization problems encountered in systems engineering and architecting. It also illustrates the applicability of orthogonal array experiment in systems engineering and architecting with two examples: verification and validation of the performance of a bandwidth allocation algorithm and architecting of a system of systems to respond to small boat attacks by terrorists. The orthogonal array experiment approach does not call for linearization of nonlinear engineering optimization problems; using orthogonal arrays, it solves them directly by carrying out the smallest possible number of experiments and determining their solutions from the results of the experiments. The orthogonal array experiment method has been found to be effective and efficient for these problems. The feasibility of applying the orthogonal array experiment approach to these problems suggests its potential application to other optimization problems encountered in systems engineering and architecting. © 2010 Wiley Periodicals, Inc. Syst Eng 14: 208–222, 2011
Dynamic maritime systems inquiry: The DIVER approach
Authors: Ng Tsan‐Sheng , Lam Shao‐Wei
Published: September 2010

The approach of thinking about systems as a whole with the explicit consideration of complex interactions between its constituents is the key conceptual framework underlying systems thinking. Such an approach is particularly useful for unraveling the dynamic interactions that confounds present‐day maritime systems. In this work, we propose the DIVER systems inquiry framework as a logical and platform to guide the systems thinking process in elucidating the maritime dynamics. We describe the implementation of system dynamics modeling and simulation as a particularly relevant tool within this framework. Its role as a structural modeling and analysis tool for various supply‐demand problems is described. Furthermore, as a means to facilitate the systems thinking process in this framework, we propose a set of archetypical system structures that can explain some commonly observed maritime dynamics. Finally, a case study on the evolution of global container ship capacity based on DIVER is presented. © 2010 Wiley Periodicals, Inc. Syst Eng 14:
Prevalence of maternal cardiac defects in women with high‐resistance uterine artery Doppler indices
Authors: Melchiorre K. , Sutherland G. R. , Liberati M. , Bhide A. , Thilaganathan B.
Published: September 2010

Objectives

To compare the prevalence of previously undiagnosed cardiac structural abnormalities in pregnant women with normal‐ and high‐resistance midtrimester uterine artery Doppler indices.

Methods

Maternal transthoracic echocardiography was undertaken in asymptomatic pregnant women after uterine artery Doppler screening for pre‐eclampsia at 21–23 weeks' gestation. Women with a mean uterine artery pulsatility index above the 90th centile (1.25) for the local population (multiethnic, socially diverse and migrant) were considered to have high‐resistance uteroplacental blood flow indices. The prevalence of newly diagnosed cardiac structural defects in these women was recorded.

Results

A total of 491 women underwent echocardiography, of whom 205 had high‐resistance uterine artery blood flow indices. There were nine previously undiagnosed, functionally significant cardiac defects in the high‐resistance uterine artery blood flow group and only one, functionally insignificant cardiac defect in the normal‐resistance group (P = 0.005; relative risk = 12.6, 95% confidence interval, 1.60–98.34). Multiple regression analysis demonstrated that both uterine artery Doppler indices (P = 0.024) and ethnicity (P = 0.048) contributed independently towards a higher prevalence of cardiac defects.

Conclusions

The prevalence of previously undiagnosed maternal cardiac structural abnormalities is significantly increased in women with high midtrimester uterine artery Doppler resistance indices. This observation has important consequences for the current and long‐term medical care provided to these patients. Detailed maternal cardiac assessment with echocardiography may be required in migrant women with high uterine artery Doppler indices. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of anterior sacral meningocele
Authors: Sumi A. , Sato Y. , Kakui K. , Tatsumi K. , Fujiwara H. , Konishi I.
Published: September 2010

Anterior sacral meningocele is an extremely rare condition and there has been only one previous report of a prenatal diagnosis. We report the case of a 36‐year‐old primigravida who was referred following detection of a huge fetal pelvic cyst on routine ultrasound examination at 19 + 4 weeks' gestation. Neither fetal ultrasound nor magnetic resonance imaging (MRI) at 20 + 5 weeks' gestation could detect communication between the cyst and the spinal cord. Because extension of the pear‐shaped cyst through the pelvic diaphragm down to the perineum was reminiscent of dilated vagina and uterine cervix, a tentative diagnosis of hydrometrocolpos secondary to imperforate hymen was considered. On follow‐up MRI at 33 + 5 weeks' gestation, a narrow stalk connecting the pelvic cyst and the spinal canal through the anterior sacral foramen was clearly delineated, allowing us to reach the prenatal diagnosis of anterior sacral meningocele. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Einsatz von Vorpumpen im Aluminium‐Ätzprozeß Erprobung trockenverdichtender Klauenpumpen und ölgedichteter Drehschiebervakuumpumpen im Vergleich
Authors: Bachmann Paul , Kuhn Monika
Published: September 2010

Wir haben trockenverdichtende Vakuumpumpen vom Klauenprinzip und ölgedichtete Drehschiebervakuumpumpen als Vorpumpen beim Ätzen von AlSi 1‐Substraten erprobt. Beide Pumptypen mußten dabei gleichermaßen sublimierendes Aluminiumtrichlorid (AlCl3) wie korrosives Bortrichlorid (BCl3) und Chlor (Cl2) bewältigen. In Drehschiebervakuumpumpen wird die Hauptmenge des AlCl3 als Feststoff im Öl akkumuliert und muß durch geeignete Ölfilter aus dem Öl entfernt werden. Die zunehmende Zersetzung des teueren PFPE‐Öls durch AlCl3, die sich durch eine schrittweise Verschlechterung des erreichbaren Enddrucks bemerkbar macht, wurde IR‐spektroskopisch verfolgt. Nach einem Durchsatz von 10.000 Wafern muß der Ölfilter gewechselt werden. Nach 30.000 Wafern ist eine komplette Wartung der Drehschiebervakuumpumpe erforderlich. Demgegenüber wird, geeignete Betriebsweise vorausgesetzt, AlCl3 problemlos durch die ölfrei verdichtende Vakuumpumpe hindurch gefördert.

Etwa 100.000 Wafer wurden geätzt, ca. 4 kg AlCl3 durch die Klauenpumpe gefördert, ohne daß eine Wartung erforderlich war. Die Pumpe wurde anschließend demontiert, sie befand sich in makellosem Zustand.
Die Entwicklung der Turbomolekularpumpe
Authors: Henning Jörgen
Published: September 2010

Von den Anfängen der Entwicklung der Turbomolekularpumpe ausgehend, wird die technische Entwicklung dieser Vakuumpumpe bis zum heutigen Stand der Technik behandelt. Die neuesten Kombinationen von Turbomolekularpumpen mit molekularen Pumpstufen ermöglichen den Einsatz von kleinen trockenen Vorpumpen. Trends für die zukünftige Entwicklung bei Turbomolekularpumpen werden erwähnt.
Aufbau, Betriebsverhalten und Regelbarkeit von Dampfstrahl‐Vakuumpumpen
Authors: Hinrichs Frerich
Published: September 2010

Es werden die wichtigsten Grundlagen, die besonderen Merkmale und Eigenschaften von Dampfstrahl‐Vakuumpumpen erklärt.

Unabhängig von der Art der Vakuumpumpe werden Maßnahmen geschildert, die dazu dienen, möglichst wenig Schadstoffe in die Umwelt abzugeben. Es wird dabei erläutert, mit wieviel Schadstoff sich die Leckluft sättigt, und daraus die Konsequenz gezogen, Vakuumanlagen möglichst gut abzudichten. Vakuumpumpen sollen nicht überdimensioniert sein, weil sie sonst, ihrem Saugvermögen entsprechend, mehr Schadstoffe absaugen als notwendig ist. Dazu gehört auch, daß man das Saugvermögen der Vakuumpumpe regelt. Die verschiedenen Möglichkeiten, die es hierfür bei Verwendung von Dampfstrahl‐Vakuumpumpen gibt, werden aufgezeigt.

Um Energie einzusparen, werden Dampfstrahl‐Vakuumpumpen mit Kon‐#### ###densatoren und anderen Vakuumpumpen kombiniert. Auf zusätzliche Energiesparmöglichkeiten wie Dampfersparnis‐Regelung, Abschalten einzelner Verdichterstufen, Einsatz von Kältemitteln etc. wird hingewiesen. Dampfstrahl‐Vakuumpumpen werden nicht nur mit Wasserdampf, sondern auch mit anderen Dämpfen betrieben und arbeiten dann abwasserfrei. Dampfstrahl‐Vakuumpumpen zeichnen sich durch maximale Betriebssicherheit und geringen Wartungsaufwand aus.
Vakuumtechnik im Chemielabor
Authors: Eckle Franz J. , Jorisch Wolfgang , Lachenmann Rudolf
Published: September 2010

Es werden neue Wege zur Vakuumerzeugung im Chemielabor aufgezeigt.

Oberstes Ziel ist, Umweltschutz zu praktizieren und dabei die Betriebskosten für die Vakuumerzeugung gering zu halten.

Darüber hinaus wird über den richtigen Einsatz sowie über notwendige konstruktive Details moderner Vakuumerzeuger wie Drehschiebervakuumpumpen und Membranvakuumpumpen berichtet.

Der Betrieb dieser Vakuumerzeuger kann durch geeignete Vakuumregler optimiert werden. Über Vakuumregler für das Chemielabor wird ebenfalls referiert.
Stress tuning in AIN thin films
Authors: Rille E. , Öfner H. , Zarwasch R. , Pulker H. K.
Published: September 2010

Aluminium nitride films were deposited on fused silica by reactive dc magnetron sputtering from an Al‐target in an Ar/N2 atmosphere.

In‐situ measurements during deposition provided data concerning mechanical stresses inherent to the growing thin films. By variation of both the gas composition (Ar, N2) and the total gas flow in the vacuum chamber, the occuring intrinsic stresses could be shifted in magnitude and direction. Stress values of the AIN films ranged from −0.9 GPa (compressive) to +1.2 GPa (tensile) when the Ar/N2 ratio was varied between 3:1 and 1:3 for the different total gas flows of 50 sccm, 100 sccm, and 200 sccm (corresponding to total gas pressures of approximately 2 × 10−1 Pa, 4 × 10−1 Pa, and 8 × 10−1 Pa respectively).

Investigations of optical and structural film properties were carried out and the results were related to the observed film stress.
Monte Carlo simulation of a control for cathodic sputtering
Authors: Mohnke Andreas
Published: September 2010

Subject is a set‐up for gas pressure and discharge power regulation of a cathodic sputtering plant. It comprises two film thickness monitors and a control unit. The film thickness monitors measure the deposition rate at target and substrate level. By means of a computer the control unit calculates a quotient from the monitor data and compares it with a set value. Any change in gas pressure or discharge power leads to a deviation of the quotient from the set value. The control unit eliminates the deviation by a regulation of gas pressure or discharge power.

The Monte Carlo method makes it possible to calculate the pressure dependence of the set‐sup. It was not possible to determine a relationship between discharge power and the output signal of the control unit by the used theoretical model.
Models of risk construction: some applications to climate change
Authors: Breakwell Glynis M.
Published: September 2010

Social psychological models that describe how people perceive and react to hazards are presented. A risk representation is a product of a process in which a hazard is recognized, its characteristics identified, and the probability of its negative impacts occurring are estimated. This will often include developing an explanation for how the hazard has come into being. The ‘psychometric paradigm’ as a method for examining the perceived characteristics of hazards is summarized before proceeding to outline the ‘mental models’ approach for analyzing risk representations. The role of affect (‘the affect heuristic’, anticipated regret, fear, and anger) in risk representations is explored. Evidence of the impact of individual differences (in particular, in vulnerability and self‐efficacy) upon risk reactions is analyzed. The Social Amplification of Risk Framework (SARF) is used to introduce the significance of social influence processes in shaping the risk representations. SARF does not specify the processes that determine substance, form, or acceptance of risk representations. The work on the effect of hazard sequences, hazard templates, and hazard negotiation on amplification processes partially rectifies this. However, there are two other theoretical approaches that have been used in this area are summarized: Social Representations Theory and Identity Processes Theory.

Examples of research on climate change risk representations using these models of risk construction are presented.WIREs Clim Change2010 1 857–870 DOI: 10.1002/wcc.74

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Behavior Change and Responses

Perceptions, Behavior, and Communication of Climate Change > Perceptions of Climate Change

Perceptions, Behavior, and Communication of Climate Change > Social Amplification/Attenuation of Climate Risks
Wavelet methods
Authors: Fryzlewicz Piotr
Published: September 2010

This overview article motivates the use of wavelets in statistics and introduces the basic mathematics behind the construction of wavelets. Topics covered include the continuous and discrete wavelet transforms, multiresolution analysis, and the non‐decimated wavelet transform. We describe the basic mechanics of nonparametric function estimation via wavelets, emphasizing the concepts of sparsity and thresholding. A simple proof of the mean‐square consistency of the wavelet estimator is also included. The article ends with two special topics: function estimation with unbalanced Haar wavelets and variance stabilization via the Haar–Fisz transformation.WIREs Comp Stat2010 2 654–667 DOI: 10.1002/wics.124

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Density Estimation

Statistical Learning and Exploratory Methods of the Data Sciences > Exploratory Data Analysis

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods

Applications of Computational Statistics > Signal and Image Processing and Coding
The zebrafish:scalable in vivo modeling for systems biology
Authors: Deo Rahul C. , MacRae Calum A.
Published: September 2010

The zebrafish offers a scalable vertebrate model for many areas of biologic investigation. There is substantial conservation of genetic and genomic features and, at a higher order, conservation of intermolecular networks, as well as physiologic systems and phenotypes. We highlight recent work demonstrating the extent of this homology, and efforts to develop high‐throughput phenotyping strategies suited to genetic or chemical screening on a scale compatible with in vivo validation for systems biology. We discuss the implications of these approaches for functional annotation of the genome, elucidation of multicellular processes in vivo, and mechanistic exploration of hypotheses generated by a broad range of ‘unbiased’ 'omic technologies such as expression profiling and genome‐wide association. Finally, we outline potential strategies for the application of the zebrafish to the systematic study of phenotypic architecture, disease heterogeneity and drug responses. WIREs Syst Biol Med 2011 3 335–346 DOI: 10.1002/wsbm.117

This article is categorized under:

Physiology > Physiology of Model Organisms
Two New Silver(I) Ammine Complexes by Displacement Reaction Between [Ag(NH3)2]+ Ions and Different Pyridine‐4,5‐Imidazoledicarboxylic Acids
Authors: Zhou Rui‐Sha , Song Jiang‐Feng , Li Yan‐Bin , Xu Chun‐Yan , Yang Xiao‐Feng
Published: September 2010

[Ag(NH3)2]+ ions are chosen as an initial reaction precursor because of its simple displacement reaction and intrinsic arrangement as well as specific coordination directionality. Two new silver(I) ammine complexes, Ag2(NH3)HL2 (2) and Ag2(NH3)2HL3 (3), were obtained by a simple substitution reaction between [Ag(NH3)2]+ ions and pyridine‐4,5‐imidazoledicarboxylic acid [H3L2 = 2‐(3′‐pyridyl) 4,5‐imidazoledicarboxylic acid and H3L3 = 2‐(4′‐pyridyl) 4,5‐imidazoledicarboxylic acid]. Silver dimers are connected into a 2D layer and 1D chain in complexes 2 and 3, respectively. In complex 2 two kinds of displacement reactions (mono‐substituting and bis‐substituting) occurred between the ammine molecules in [Ag(NH3)2]+ ions and H3L2, however, only the mono‐substituting reaction occurs in complex 3.
Synthesis and Characterization of 3,5‐Diamino‐1,2,4‐triazolium Dinitramide
Authors: Klapötke Thomas M. , Martin Franz A. , Mayr Norbert T. , Stierstorfer Jörg
Published: September 2010

3,5‐Diamino‐1,2,4‐triazole (1, guanozol) was protonated with diluted hydrochloric acid, nitric acid, as well as perchloric acid forming 3,5‐diamino‐1,2,4‐triazolium chloride hemihydrate (2), 3,5‐diamino‐1,2,4‐triazolium nitrate (3) and 3,5‐diamino‐1,2,4‐triazolium perchlorate (4), respectively. In a second step 4 reacted with potassium dinitramide forming 3,5‐diamino‐1,2,4‐triazolium dinitramide (5) and low soluble potassium perchlorate. Compounds 2–5 were characterized by low temperature single X‐ray diffraction, IR and Raman as well as multinuclear NMR spectroscopy, mass spectrometry and differential scanning calorimetry. The heats of formation of 1–5 were calculated by the CBS‐4M method to be 81.1 (1), 124.7 (2), –76.1 (3), –25.2 (4) and 138.7 (5) kJ·mol–1. With these values as well as the X‐ray densities several detonation parameters were calculated using both computer codes EXPLO5.03 and EXPLO5.04. In addition, the sensitivities of 1–5 were determined by the BAM drophammer and friction tester as well as a small scale electrical discharge device.