bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi‐contrast reconstruction with Bayesian compressed sensing
Authors: Bilgic Berkin , Goyal Vivek K , Adalsteinsson Elfar 
Published: June 2011

AbstractClinical imaging with structural MRI routinely relies on multiple acquisitions of the same region of interest under several different contrast preparations. This work presents a reconstruction algorithm based on Bayesian compressed sensing to jointly reconstruct a set of images from undersampled k‐space data with higher fidelity than when the images are reconstructed either individually or jointly by a previously proposed algorithm, M‐FOCUSS. The joint inference problem is formulated in a hierarchical Bayesian setting, wherein solving each of the inverse problems corresponds to finding the parameters (here, image gradient coefficients) associated with each of the images. The variance of image gradients across contrasts for a single volumetric spatial position is a single hyperparameter. All of the images from the same anatomical region, but with different contrast properties, contribute to the estimation of the hyperparameters, and once they are found, the k‐space data belonging to each image are used independently to infer the image gradients. Thus, commonality of image spatial structure across contrasts is exploited without the problematic assumption of correlation across contrasts. Examples demonstrate improved reconstruction quality (up to a factor of 4 in root‐mean‐square error) compared with previous compressed sensing algorithms and show the benefit of joint inversion under a hierarchical Bayesian model. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Serial MRI characterization of the functional and morphological changes in mouse lung in response to cardiac remodeling following myocardial infarction
Authors: Alsaid Hasan , Bao Weike , Rambo Mary V. , Logan Gregory A. , Figueroa David J. , Lenhard Stephen C. , Kotzer Charles J. , Burgert Mark E. , Willette Robert N. , Ferrari Victor A. , Jucker Beat M. 
Published: June 2011

AbstractThe temporal evolution of heart failure and associated pulmonary congestion in rodent heart failure models has not yet been characterized simultaneously and noninvasively. In this study, MRI was used to assess the serial progression of left‐ventricular dysfunction and lung congestion in mice following myocardial infarction (MI). Cardiac and lung 1H MRI was performed at baseline and every 3 days up to 13 days postsurgery in sham and MI mice. Respiratory parameters and terminal lung mechanics were assessed followed by histological analysis. MRI revealed that the MI induced significant pulmonary congestion/edema as detected by increased MRI signal intensity and was associated with increased lung volume and reduced cardiac contractility. Pulmonary function was also depressed in MI‐mice, reflected by a reduced tidal volume and a low minute ventilation rate. Additionally, MI significantly increased lung resistance, markedly reduced lung compliance and total lung capacity and significantly increased lung weights by 57%. Significant correlations were observed between the MRI measured lung congestion, lung volume, ejection fraction, and lung wet‐weight parameters. This study demonstrates that MRI may be of significant value in evaluating therapies aimed at primary intervention for lung congestion and secondary prevention of unfavorable cardiac remodeling. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Whole brain susceptibility mapping using compressed sensing
Authors: Wu Bing , Li Wei , Guidon Arnaud , Liu Chunlei 
Published: June 2011

AbstractThe derivation of susceptibility from image phase is hampered by the ill‐conditioned filter inversion in certain k‐space regions. In this article, compressed sensing is used to compensate for the k‐space regions where direct filter inversion is unstable. A significantly lower level of streaking artifacts is produced in the resulting susceptibility maps for both simulated and in vivo data sets compared to outcomes obtained using the direct threshold method. It is also demonstrated that the compressed sensing based method outperforms regularization based methods. The key difference between the regularized inversions and compressed sensing compensated inversions is that, in the former case, the entire k‐space spectrum estimation is affected by the ill‐conditioned filter inversion in certain k‐space regions, whereas in the compressed sensing based method only the ill‐conditioned k‐space regions are estimated. In the susceptibility map calculated from the phase measurement obtained using a 3T scanner, not only are the iron‐rich regions well depicted, but good contrast between white and gray matter interfaces that feature a low level of susceptibility variations are also obtained. The correlation between the iron content and the susceptibility levels in iron‐rich deep nucleus regions is studied, and strong linear relationships are observed which agree with previous findings. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
On the performance of T2* correction methods for quantification of hepatic fat content
Authors: Reeder Scott B. , Bice Emily K. , Yu Huanzhou , Hernando Diego , Pineda Angel R. 
Published: June 2011

AbstractNonalcoholic fatty liver disease is the most prevalent chronic liver disease in Western societies. MRI can quantify liver fat, the hallmark feature of nonalcoholic fatty liver disease, so long as multiple confounding factors including T2* decay are addressed. Recently developed MRI methods that correct for T2* to improve the accuracy of fat quantification either assume a common T2* (single‐T2*) for better stability and noise performance or independently estimate the T2* for water and fat (dual‐T2*) for reduced bias, but with noise performance penalty. In this study, the tradeoff between bias and variance for different T2* correction methods is analyzed using the Cramér‐Rao bound analysis for biased estimators and is validated using Monte Carlo experiments. A noise performance metric for estimation of fat fraction is proposed. Cramér‐Rao bound analysis for biased estimators was used to compute the metric at different echo combinations. Optimization was performed for six echoes and typical T2* values. This analysis showed that all methods have better noise performance with very short first echo times and echo spacing of ∼π/2 for single‐T2* correction, and ∼2π/3 for dual‐T2* correction. Interestingly, when an echo spacing and first echo shift of ∼π/2 are used, methods without T2* correction have less than 5% bias in the estimates of fat fraction. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Spurenstoffe beeinflussen das Zusammenleben
Authors: Klaschka Ursula 
Published: June 2011

AbstractStören Duftstoffe aus Parfüm, Kosmetika, Wasch‐ und Reinigungsmitteln die Kommunikation und das Leben von Umweltorganismen? Die Erforschung dieses Infochemikalieneffekts ist ein neuer Zweig der Ökotoxikologie.
Die Risiken beim Einkauf
Authors: Hermann Marco 
Published: June 2011

AbstractNaturkatastrophen, Rohstoffknappheit, Preisänderungen, volatile Märkte oder politische Instabilität — Lieferketten sind vielen Risiken ausgesetzt. Zusammen mit hohen Effizienzanforderungen entstehen instabile Lieferketten. Wie lässt sich dagegen steuern?
On the nature of bladder sensation: The concept of sensory modulation
Authors: De Wachter S.G. , Heeringa R. , van Koeveringe G.A. , Gillespie J.I. 
Published: June 2011

AbstractAimsGoing to the toilet is an essential everyday event. Normally, we do not give much thought to the sensations and factors that trigger voiding behavior: we just go. For many people, this apparently simple task is complicated and dominates their life. They have strong sensations and sudden desires to void, often resulting in incontinence. It is therefore important that we understand the origins for this functional change and identify means to alleviate it.MethodsLiterature survey.ResultsA considerable body of work has focused on this problem and ideas and concepts on the nature of bladder sensations are embedded in the literature. In this paper we argue the necessity to return to first principles and a re‐examination of the problem. We explore the use of focus groups to identify relevant bladder sensation and what triggers ‘bladder’ behavior. We argue that there are differences in what can be described as ‘introspective bladder sensations’ and the sensations reported immediately before a void, ‘void sensations’. Finally, we propose an alternative model describing how peripheral information generating ‘introspective sensations’ and ‘void sensations’ might be different but interrelated sensations. By exploring such ideas and identifying such complexity it is our intention to stimulate debate and generate further research in the field in order to understand better the physiology of bladder sensation and the pathology of increased urge, frequency and incontinence.ConclusionsReview of the literature on bladder sensation and the established ideas suggests that we might be missing something and the problem of normal and increased sensation and of urgency may be much more complex. Neurourol. Urodynam. 30:1220–1226, 2011. © 2011 Wiley‐Liss, Inc.
Beta3‐adrenoceptors in the rat sacral spinal cord and their functional relevance in micturition under normal conditions and in a model of partial urethral obstruction
Authors: Füllhase Claudius , Soler Roberto , Westerling‐Andersson Kristian , Andersson Karl‐Erik 
Published: June 2011

AbstractAimsBeta3‐adrenoceptor selective agonists are evaluated as a new treatment for patients with lower urinary tract symptoms . It is believed that β3‐AR selective agonists exert their effects via a peripheral site of action. However, β3‐ARs have been found in brain tissue. This study examined whether β3‐ARs are present in rat sacral spinal cord, and whether there are differences in β3‐AR expression between normal and partial urethral obstruction (PUO) animals, and furthermore assessed the functional relevance of spinal β3‐ARs for micturition.MethodsThirty‐eight male Sprague–Dawley rats underwent either PUO or sham‐operation. Two weeks after operation, half of the animals were used for histomorphological analysis. Remaining animals were used for functional experiments, where a β3‐AR selective agonist, BRL 37344, was given intrathecally. Bladder function was assessed by continuous cystometry in non‐anesthetized animals before and after drug administration.ResultsBeta3‐ARs were found in sacral spinal cord segments with an accumulation in the ventral horn. There was a significant increase of β3‐AR expression in obstructed rats. In functional experiments obstructed rats showed increased bladder weight, micturition frequency, spontaneous activity, and bladder pressures (all P < 0.05) compared to controls. Intrathecally administered BRL 37344 showed no effect in non‐obstructed rats. In obstructed rats intrathecal BRL 37344 significantly reduced bladder pressures, spontaneous activity, and micturition frequency (all P < 0.05).ConclusionsBeta3‐ARs are present in rat sacral spinal cord, and are significantly up‐regulated after PUO. Besides their well‐established peripheral site of action in the treatment of voiding dysfunction, β3‐AR selective agonists might exert relevant effects at a central nervous site of action. Neurourol. Urodynam. 30:1382–1387, 2011. © 2011 Wiley‐Liss, Inc.
Detecting OAM&P design defects using a feature interaction approach
Authors: Chentouf Zohair 
Published: June 2011

SUMMARYIn the telecommunications service engineering world, the feature interaction (FI) problem is defined as the situation in which running services at the same time undesirably alters their behaviour. It is also known as the service interaction problem. FIs may occur between various types of services, ranging from signalling protocol features to value‐added end‐user services. The problem has been widely investigated for those types of services. However, sufficient attention has not been paid to operation, administration, management and provisioning (OAM&P) features like creating a new customer account or registering a new gateway as part of the network. The present paper addresses the detection of OAM&P FIs in Internet telephony architectures. The solution consists in an adapted version of a known FI detection method. A simple feature modelling language and an FI detection procedure are proposed. A validation with a case study is also reported. Copyright © 2011 John Wiley & Sons, Ltd.
Increased midkine expression correlates with desmoid tumour recurrence: a potential biomarker and therapeutic target
Authors: Colombo Chiara , Creighton Chad J , Ghadimi Markus P , Bolshakov Svetlana , Warneke Carla L , Zhang Yiqun , Lusby Kristelle , Zhu Shirley , Lazar Alexander J , West Robert B , de Rijn Matt van , Lev Dina 
Published: June 2011

AbstractDesmoid tumours (DTs) are soft tissue monoclonal neoplasms exhibiting a unique phenotype, consisting of aggressive local invasiveness without metastatic capacity. While DTs can infrequently occur as part of familial adenomatosis polyposis, most cases arise sporadically. Sporadic DTs harbour a high prevalence of CTNNB1 mutations and hence increased β‐catenin signalling. However, β‐catenin downstream transcriptional targets and other molecular deregulations operative in DT inception and progression are currently not well defined, contributing to the lack of sensitive molecular prognosticators and efficacious targeted therapeutic strategies. We compared the gene expression profiles of 14 sporadic DTs to those of five corresponding normal tissues and six solitary fibrous tumour specimens. A DT expression signature consisting of 636 up‐ and 119 down‐regulated genes highly enriched for extracellular matrix, cell adhesion and wound healing‐related proteins was generated. Furthermore, 98 (15%) of the over‐expressed genes were demonstrated to contain a TCF/LEF consensus binding site in their promoters, possibly heralding direct β‐catenin downstream targets relevant to DT. The protein products of three of the up‐regulated DT genes: ADAM12, MMP2 and midkine, were found to be commonly expressed in a large cohort of human DT samples assembled on a tissue microarray. Interestingly, enhanced midkine expression significantly correlated with a higher propensity and decreased time for primary DT recurrence (log‐rank p = 0.0025). Finally, midkine was found to enhance the migration and invasion of primary DT cell cultures. Taken together, these studies provide insights into potential DT molecular aberrations and novel β‐catenin transcriptional targets. Further studies to confirm the utility of midkine as a clinical DT molecular prognosticator and a potential therapeutic target are therefore warranted. Raw gene array data can be found at: http://smd.stanford.edu/ Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Quantitative proteomics by 2‐DE, 16O/18O labelling and linear ion trap mass spectrometry analysis of lymph nodes from piglets inoculated by porcine circovirus type 2
Authors: Ramírez‐Boo María , Núnez Estefania , Jorge Inmaculada , Navarro Pedro , Fernandes Lana T. , Segalés Joaquim , Garrido Juan J. , Vázquez Jesús , Moreno Ángela 
Published: June 2011

AbstractPorcine circovirus type 2 (PCV2) has been identified as the essential causal agent of postweaning multisystemic wasting syndrome. However, little is known regarding the mechanism(s) underlying the pathogenesis of PCV2‐induced disease and the interaction of the virus with the host immune system. Here, we present a proteomics study on inguinal lymph nodes of piglets inoculated with PCV2, in order to better understand the pathogenesis of postweaning multisystemic wasting syndrome and the pathways might be affected after infection. We used two proteomics strategies, 2‐DE and 1‐DE followed by 16O/18O peptide labelling and peptide identification and quantification by MS. More than 100 proteins were found to be differentially regulated and the results obtained by the two strategies were fairly concordant but also complementary, the 18O labelling approach being a more robust alternative. Analysis of these proteins by systems biology tools revealed the implication of acute phase response and NrF2‐mediated oxidative stress, suggesting a putative role for these pathways in the pig immune response. Besides, CD81 was found to be up‐regulated, suggesting a possible role in the internalization of the virus. The use of proteomics technologies together with biology analysis systems opens up the way to gain more exhaustive and systematic knowledge of virus–pathogen interactions.
Regional distribution of neuroendocrine cells in the urogenital duct system of the male rat
Authors: Aumüller Gerhard , Doll Andreas , Wennemuth Gunther , Dizeyi Nishtman , Abrahamsson Per‐Anders , Wilhelm Beate 
Published: June 2011

AbstractBACKGROUNDNeuroendocrine (NE) cells are frequently present in the human prostate and urethra, whereas they are lacking in the other urogenital organs. This study was undertaken as there are only few detailed studies available on the distribution, form and function of NE cells and the structure of excretory ducts of the accessory sex organs in the male rat.METHODSSystematic gross anatomical dissections were combined with immunohistochemical and electron microscopic studies of the excretory ducts of the urogenital glands in male rats, with particular focus on the distribution and ultrastructure of the NE cells.RESULTSThe topography and structure of the excretory ducts of the different glands were characterized in detail and analyzed for the distribution of NE cells. These are present (in falling frequencies) in the ducts of seminal vesicles and ventral and lateral prostate and are rare in ducts of coagulating gland, dorsal prostate, urethral epithelium, and excretory ducts of the (bulbo) urethral glands. They are absent in the respective glands proper, the deferent duct and ejaculatory ampulla. Approximately 40% of the NE cells of the ventral prostate ducts are of the “open” type, whereas these are less frequent (14%) in the seminal vesicle ducts, where the “closed” type prevails.CONCLUSIONSNE cells are present in unequal quantities in the excretory ducts of the accessory sex glands, but they are absent in the glands proper and the deferent ducts. This distribution pattern points to a strictly localized function and differentiation potency of NE precursor cells. Prostate 72:326–337, 2012. © 2011 Wiley Periodicals, Inc.
Diagnostic and impact studies of a wavelet formulation of background‐error correlations in a global model
Authors: Varella Hubert , Berre Loïk , Desroziers Gérald 
Published: June 2011

AbstractA wavelet formulation on the sphere is being considered for modelling heterogeneous background‐error correlations for the Météo‐France global numerical weather prediction (NWP) model. This approach is compared with the operational spectral formulation, which is horizontally homogeneous to a large extent. Diagnostic studies have been conducted to examine geographical variations of three‐dimensional correlations over the whole globe. Results indicate that the contrast between relatively broad horizontal correlations in the Tropics and sharp ones in midlatitudes is well represented by the wavelet formulation. Heterogeneities in vertical correlations are also better captured in the wavelet approach than in the spectral one, with visible changes as functions of e.g. latitude and land/sea contrasts. In addition, wavelet‐based correlation estimates are shown to be partly sensitive to the choice of the calibration period. The impact of the wavelet formulation on the forecast quality has been investigated during a three‐week calibration period, and also during the following three weeks. While the impact of the wavelet formulation is globally positive during the two periods, it tends to be more spectacular during the calibration time interval, as expected. These results indicate that an on‐line calibration should be considered in the future, in order to exploit fully the ability of wavelets to extract correlation heterogeneities from ensemble data. Copyright © 2011 Royal Meteorological Society
Evaluation of combined matrix‐assisted laser desorption/ionization time‐of‐flight and matrix‐assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry experiments for peptide mass fingerprinting analysis
Authors: da Silva David , Wasselin Thierry , Carré Vincent , Chaimbault Patrick , Bezdetnaya Lina , Maunit Benoît , Muller Jean‐François 
Published: June 2011

Peptide Mass Fingerprinting (PMF) is still of significant interest in proteomics because it allows a large number of complex samples to be rapidly screened and characterized. The main part of post‐translational modifications is generally preserved. In some specific cases, PMF suffers from ambiguous or unsuccessful identification. In order to improve its reliability, a combined approach using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) and matrix‐assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI‐FTICRMS) was evaluated.The study was carried out on bovine serum albumin (BSA) digest. The influence of several important parameters (the matrix, the sample preparation method, the amount of the analyte) on the MOWSE score and the protein sequence coverage were evaluated to allow the identification of specific effects. A careful investigation of the sequence coverage obtained by each kind of experiment ensured the detection of specific peptides for each experimental condition.Results highlighted that DHB‐FTICRMS and DHB‐ or CHCA‐TOFMS are the most suited combinations of experimental conditions to achieve PMF analysis. The association (convolution) of the data obtained by each of these techniques ensured a significant increase in the MOWSE score and the protein sequence coverage. Copyright © 2011 John Wiley & Sons, Ltd.
On fitting generalized linear mixed‐effects models for binary responses using different statistical packages
Authors: Zhang Hui , Lu Naiji , Feng Changyong , Thurston Sally W. , Xia Yinglin , Zhu Liang , Tu Xin M. 
Published: June 2011

AbstractThe generalized linear mixed‐effects model (GLMM) is a popular paradigm to extend models for cross‐sectional data to a longitudinal setting. When applied to modeling binary responses, different software packages and even different procedures within a package may give quite different results. In this report, we describe the statistical approaches that underlie these different procedures and discuss their strengths and weaknesses when applied to fit correlated binary responses. We then illustrate these considerations by applying these procedures implemented in some popular software packages to simulated and real study data. Our simulation results indicate a lack of reliability for most of the procedures considered, which carries significant implications for applying such popular software packages in practice. Copyright © 2011 John Wiley & Sons, Ltd.
Statistics of shape
Authors: Small Christopher G. 
Published: June 2011

AbstractThis article reviews various statistical methods that are available for the analysis of the shapes of images or objects. Statistical shape analysis is too large a topic to be reviewed in full. So, this review concentrates on shape analysis by means of landmarks, and in particular on the representation of landmark shapes on manifolds that was proposed by D. G. Kendall. The use of Kendall shape analysis on landmarks is briefly contrasted with alternative ways of representing and analyzing shapes. WIREs Comp Stat 2011 3 428–433 DOI: 10.1002/wics.173This article is categorized under:

Applications of Computational Statistics > Computational Mathematics