bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolomics Identifies Perturbations in Human Disorders of Propionate Metabolism
Authors: Wikoff William R , Gangoiti Jon A , Barshop Bruce A , Siuzdak Gary 
Published: October 2007

AbstractBackground: We applied untargeted mass spectrometry-based metabolomics to the diseases methylmalonic acidemia (MMA) and propionic acidemia (PA).Methods: We used a screening platform that used untargeted, mass-based metabolomics of methanol-extracted plasma to find significantly different molecular features in human plasma samples from MMA and PA patients and from healthy individuals. Capillary reverse phase liquid chromatography (4 μL/min) was interfaced to a TOF mass spectrometer, and data were processed using nonlinear alignment software (XCMS) and an online database (METLIN) to find and identify metabolites differentially regulated in disease.Results: Of the approximately 3500 features measured, propionyl carnitine was easily identified as the best biomarker of disease (P value 1.3 × 10−18), demonstrating the proof-of-concept use of untargeted metabolomics in clinical chemistry discovery. Five additional acylcarnitine metabolites showed significant differentiation between plasma from patients and healthy individuals, and γ-butyrobetaine was highly increased in a subset of patients. Two acylcarnitine metabolites and numerous unidentified species differentiate MMA and PA. Many metabolites that do not appear in any public database, and that remain unidentified, varied significantly between normal, MMA, and PA, underscoring the complex downstream metabolic effects resulting from the defect in a single enzyme.Conclusions: This proof-of-concept study demonstrates that metabolomics can expand the range of metabolites associated with human disease and shows that this method may be useful for disease diagnosis and patient clinical evaluation.
Analytical Validation and Biological Evaluation of a High–Molecular-Weight Adiponectin ELISA
Authors: Sinha Madhur K , Songer Traci , Xiao Qiang , Sloan John H , Wang Jin , Ji Shaoquen , Alborn William E , Davis Randy A , Swarbrick Michael M , Stanhope Kimber L , Wolfe Bruce M , Havel Peter J , Schraw Todd , Konrad Robert J , Scherer Philipp E , Mistry Jehangir S 
Published: October 2007

Abstract
Background: Of the 3 circulating multimeric forms of adiponectin, the high–molecular-weight (HMW) form, as measured by size-exclusion and/or immunoblotting techniques, is a better index of insulin sensitivity for monitoring health and disease than is total adiponectin. We aimed to develop a simple ELISA to measure HMW adiponectin.
Methods: We pretreated serum or plasma samples with digestion solution containing proteinase K (Millipore, ESDS). HMW (Millipore, EZHMWA-64K) and total adiponectin (Millipore, EZHADP-61K) concentrations were measured in treated and untreated samples, respectively, from 108 individuals and from 20 morbidly obese patients before and at 1, 3, 6, and 12 months after gastric-bypass surgery.
Results: The ELISA has a dynamic range of 3–200 μg/L and a detection limit of 0.8 μg/L. Intraassay and interassay CVs were &lt;4% and &lt;10%, respectively. Sample-dilution curves paralleled the calibration curves. Fast protein liquid chromatography profiles of the proteinase K-treated samples revealed predominantly HMW adiponectin. Values for HMW adiponectin produced with this method are comparable with those obtained with Western blot analysis (y = 0.77x − 0.15; r = 0.96; n = 56). Body mass index (BMI)- and sex-related changes were more pronounced for HMW adiponectin and percentage of HMW adiponectin than for total adiponectin. HMW and total adiponectin increased after bypass surgery, but changes in HMW adiponectin were more pronounced and preceded changes in total adiponectin.
Conclusion: This simple, rapid ELISA for HMW adiponectin recognizes the HMW isoform, produces results closely correlated with those obtained with Western blotting, and appears to better distinguish BMI-, sex-, and weight loss–associated differences than assays for total adiponectin.
Aaron Cicourel's contributions to language use, theory, method, and measurement
Authors: Davies Philip , Mehan Hugh 
Published: October 2007

AbstractAaron Cicourel's contributions to sociology and other disciplines are discussed. Cicourel brought to sociology the philosophical and linguistic principle that language plays an active role in creating and sustaining social interaction and social reality; Cicourel and his colleagues pioneered the use of videotape as an analytic tool, which enabled them to vividly illustrate the importance of organizational and interpersonal constraints on social interaction and communication. His empirical studies of healthcare and schooling uncovered linguistic and organizational practices that contribute to the assembly of steps on students' academic careers and patients' diagnoses, treatments, and healthcare outcomes. Cicourel's work provides a wealth of empirical evidence for the argument that there is a reflexive relationship between social structure and social action as displayed in language use.
Discourses in European Union organizations: Aspects of access, participation, and exclusion
Authors: Wodak Ruth 
Published: October 2007

AbstractThe aim of this paper is to make processes of co-constructing, negotiating, defining, legitimizing, and justifying inclusion/exclusion in European Union (EU) organizations transparent, both on a structural and on a discursive level. Moreover, individual experiences from migrants present everyday exclusionary practices. In this attempt, I use research on EU organizations and on discrimination in eight EU countries (focus-group discussions) as illustrative examples. I propose a ‘discourse-historical’ framework, which relates different discursive and structural forms of inclusion and exclusion to each other. I assume that many contradictions come into play, while discursive shifts in inclusion and exclusion are decided upon. These contradictions imply—
Global markets as global conversations
Authors: Cetina Karin Knorr 
Published: October 2007

AbstractFinancial markets are one of the most iconic and influential structures of our time. The foreign exchange market in particular is also the most genuinely global market—and the largest market worldwide, with an average daily turnover of 1.8 trillion US dollars. The foreign exchange market is also structurally like a massive conversational interaction system; many of its transactions are conducted through electronically mediated ‘conversations’. Transactions not conducted through conversations but through an electronic broker also display a sequential turn-taking structure. In this paper, I analyze the streaming ‘flow’ architecture of this market in terms of its sequential structures and their technological and economic aspects. I also specify and analyze several types of texted sequences that articulate and illustrate the response-based interaction system of this market. I argue that informational sequences are particularly important; the informational liquidity of this market sustains and supports the market's economic liquidity.
A personal, retrospective view of ecological validity
Authors: Cicourel Aaron V 
Published: October 2007

AbstractThe notion of ecological validity has been an abiding topic either implicitly or explicitly during my entire academic career. Ecological validity focuses on how we seek to convince others of the viability and authenticity of our claims and can be understood by our use of primary and secondary data sources such as official statistics, demographic distributions, sample surveys, structured interviews, open-ended or unstructured interviews, and recorded discourse during social interaction. Ecological validity, however, can only be approximated in the social and behavioral sciences. The key issue is the extent to which data are congruent with systematic time samples of events and activities within local institutional or organizational settings. For example, direct observation of and participation in the everyday activities or practices of human actors during their daily life experiences by the use of, when possible, audio or video recordings. Systematic behavioral sampling by biological (behavioral ecological) studies of nonhuman animals (Altmann 1974; Krebs and Davies 1997) can serve as a guide for social scientists. This paper selectively discusses three previous research projects that attempted to approximate ecological validity.
Coriolis Erosion Testing Approach for Relatively Thick Coatings
Authors: Tian Harry H. , Addie Graeme R. 
Published: October 2007

Abstract
To meet the challenge of wear and corrosion attack in various applications, coating has been an effective protection approach for the work surface of engineering components, including slurry pump wet-end parts (e.g., impellers, liners, and shells). The coated wear parts that handle flowing slurry are exposed to both sliding and impact erosion along with possible corrosion factors. In such erosive wear conditions, relatively thick coatings including overlays may be needed to extend service life of the wear components. Different wear testing methods have been used to evaluate the tribological properties of coating materials under both dry and wet wear conditions. Previous studies have shown that Coriolis erosion testing is a valuable and effective approach to study erosive wear behaviors of materials in flowing slurry conditions such as within a centrifugal slurry pump system. Although extensive research can be found on wear of hard coating materials, coating erosive wear research conducted using Coriolis wear testing methods is very limited. This paper demonstrates that Coriolis erosion testing can be applicable for both sliding and impact wear on relatively thick coatings (typically, 250 μm or thicker). By adjusting test parameters within the Coriolis erosion testing system, such as flow rate (or solids particle velocity), solids type, size, and concentration, and impact angle, various types of coatings can be tested for different erosive wear conditions. Through such Coriolis erosion testing, erosion rate and tribological characteristics of coatings can be determined and evaluated. The coating examples used in this study include NiCrSiB, NiWCrSiB, WC-NiCrSiB, and WC-Co-Cr coatings produced with flame-spray, sintering and/or high-velocity-oxygen-fuel (HVOF) and high-velocity-air-fuel (HVAF) processes. Some related factors have also been discussed.
Bewegungsintentionsschätzung auf Basis von Gelenkkoordination (Motion Intention Estimation Based on Interjoint Coordination)
Authors: Vallery Heike , Buss Martin 
Published: October 2007

Für die Gangrestitution halbseitig gelähmter Patienten durch motorisierte Orthesen, genauso wie für intelligente Prothesen, stellt die Koordinierung gesunder und robotisch unterstützter Gliedmaßen eine regelungstechnische Herausforderung dar. Der hier vorgeschlagene Ansatz verwendet die Methode der Hauptkomponentenanalyse, um die Kopplungen der Freiheitsgrade im gesunden menschlichen Gang zu analysieren. Auf Grundlage dieser statistischen Zusammenhänge werden in Echtzeit aus den Bewegungen des gesunden Beins passende Bewegungen für das kranke Bein geschätzt. So kann die Intention eines teilweise gelähmten oder beinamputierten Patienten aus seiner übrigen Körperbewegung abgeleitet werden, um die beeinträchtigten Glieder zu aktuieren oder zu überwachen. Um diesen Ansatz zu evaluieren, werden Simulationen mit aufgezeichneten Gangtrajektorien gesunder Probanden durchgeführt. Die Resultate dieser theoretischen Untersuchungen zeigen ein vielversprechendes Potential.
For the restitution of walking of a hemiplegic patient by means of a motorized orthosis, as well as in intelligent prosthetics, a major challenge is the coordination of healthy and robotically assisted limbs. The approach suggested here employs the method of Principal Components Analysis to first analyze the coupling of human joint motion in healthy subjects. Based on this knowledge, adequate motion for inoperable limbs in impaired patients is estimated on-line from sound limb motion. Thus, the intention of a partially paralyzed person or an amputee can be deduced from residual body motion, in order to coordinately actuate or supervise the impaired limbs. To evaluate the approach, simulations with recorded gait trajectories of healthy subjects are performed. The results of these theoretical investigations show a promising potential.
Kooperative Mensch-Maschine-Systeme in der Chirurgie und Rehabilitation (Cooperative Human-Machine Systems in Surgery and Rehabilitation)
Authors: Korb Werner , Burgert Oliver , Schulze-Kissing Dirk , Riener Robert 
Published: October 2007

Bestmögliche Funktionalität bei optimierter Nutzungssicherheit sind wesentliche Zielkriterien für die Gestaltung von Unterstützungssystemen. Eine Möglichkeit ist die Nutzung von kooperativen Mensch-Maschine-Systemen. Eine Übersicht über den Entwurf und die Evaluation von solchen kooperativen Systemen ist Thema des vorliegenden Artikels. Im Wesentlichen werden die Optimierung der Funktionalität und der Sicherheit sowie der Verlässlichkeit von kooperativen Systemen untersucht. Abschließend werden Anwendungsbeispiele aus der Chirurgie und Rehabilitation vorgestellt.
The optimal functionality combined with the safety are the essential criteria for support systems design. One possibility is the application of cooperative Human-Machine Systems. The objective of this article is to present an overview of the design, implementation and evaluation of cooperative Human-Machine Systems. In particular, functionality optimization, safety and reliability of such systems will be examined and analyzed. Finally we present different applications in the area of surgery and rehabilitation.
Optimierung der automatisierten Beatmung bei akutem Lungenversagen mit Hilfe der elektrischen Impedanztomographie (Enhancement of Automated Protective Ventilation Strategies in Respiratory Failure using Electrical Impedance Tomography)
Authors: Luepschen Henning , Meier Torsten , Leonhardt Steffen 
Published: October 2007

Dieser Beitrag beschreibt die erfolgreiche Umsetzung eines automatischen lungenschonenden Beatmungsverfahrens für Patienten mit akutem Lungenversagen. Der Schwerpunkt liegt auf der Integration der elektrischen Impedanztomographie (EIT) in das Gesamtkonzept und auf der Gewinnung von nichtinvasiven Regelgrößen.
This paper presents the successful realisation of an automated lung-protective ventilation method for patients suffering from acute respiratory failure. Main issues are the integration of electrical impedance tomography (EIT) into the ventilation setup and the extraction of reliable process variables.
Eignung des Electrowettingprinzips zur Wiederherstellung der menschlichen Akkommodationsfähigkeit (Suitability of the Electrowetting Principle to Restore Human Accommodation)
Authors: Bergemann Mark 
Published: October 2007

Die Beeinflussung des Benetzungsverhaltens eines elektrisch leitfähigen Fluids durch ein elektrisches Feld (Electrowetting) ist ein mögliches Wirkprinzip zur Wiederherstellung der Akkommodationsfähigkeit des menschlichen Auges durch ein mechatronisches Mikrosystem. In diesem Beitrag wird die Meniskusbewegung einer Electrowettinglinse elektromechanisch modelliert, das Verhalten im Strahlengang des Auges untersucht und die Eignung des Wirkprinzips im Hinblick auf die biomedizinische Anwendung bewertet.
Electric influence on the wetting properties of a conducting liquid (electrowetting) is one alternative to restore the accommodative ability of the human eye by means of a mechatronic microsystem. In this contribution an electromechanical model is presented which describes the meniscus´ movement of an electrowetting lens. The refractive behaviour inside the human eye is investigated and evaluated with regard to its appropriateness for the envisaged biomedical application.
Biased Distributions and Decay of Long Interspersed Nuclear Elements in the Chicken Genome
Authors: Abrusán György , Krambeck Hans-Jürgen , Junier Thomas , Giordano Joti , Warburton Peter E 
Published: October 2007

Abstract
The genomes of birds are much smaller than mammalian genomes, and transposable elements (TEs) make up only 10% of the chicken genome, compared with the 45% of the human genome. To study the mechanisms that constrain the copy numbers of TEs, and as a consequence the genome size of birds, we analyzed the distributions of LINEs (CR1's) and SINEs (MIRs) on the chicken autosomes and Z chromosome. We show that (1) CR1 repeats are longest on the Z chromosome and their length is negatively correlated with the local GC content; (2) the decay of CR1 elements is highly biased, and the 5′-ends of the insertions are lost much faster than their 3′-ends; (3) the GC distribution of CR1 repeats shows a bimodal pattern with repeats enriched in both AT-rich and GC-rich regions of the genome, but the CR1 families show large differences in their GC distribution; and (4) the few MIRs in the chicken are most abundant in regions with intermediate GC content. Our results indicate that the primary mechanism that removes repeats from the chicken genome is ectopic exchange and that the low abundance of repeats in avian genomes is likely to be the consequence of their high recombination rates.
Sequence-Level Population Simulations Over Large Genomic Regions
Authors: Hoggart Clive J , Chadeau-Hyam Marc , Clark Taane G , Lampariello Riccardo , Whittaker John C , De Iorio Maria , Balding David J 
Published: October 2007

Abstract
Simulation is an invaluable tool for investigating the effects of various population genetics modeling assumptions on resulting patterns of genetic diversity, and for assessing the performance of statistical techniques, for example those designed to detect and measure the genomic effects of selection. It is also used to investigate the effectiveness of various design options for genetic association studies. Backward-in-time simulation methods are computationally efficient and have become widely used since their introduction in the 1980s. The forward-in-time approach has substantial advantages in terms of accuracy and modeling flexibility, but at greater computational cost. We have developed flexible and efficient simulation software and a rescaling technique to aid computational efficiency that together allow the simulation of sequence-level data over large genomic regions in entire diploid populations under various scenarios for demography, mutation, selection, and recombination, the latter including hotspots and gene conversion. Our forward evolution of genomic regions (FREGENE) software is freely available from www.ebi.ac.uk/projects/BARGEN together with an ancillary program to generate phenotype labels, either binary or quantitative. In this article we discuss limitations of coalescent-based simulation, introduce the rescaling technique that makes large-scale forward-in-time simulation feasible, and demonstrate the utility of various features of FREGENE, many not previously available.
On Recombination-Induced Multiple and Simultaneous Coalescent Events
Authors: Davies Joanna L , Simančík František , Lyngsø Rune , Mailund Thomas , Hein Jotun 
Published: October 2007

Abstract
Coalescent theory deals with the dynamics of how sampled genetic material has spread through a population from a single ancestor over many generations and is ubiquitous in contemporary molecular population genetics. Inherent in most applications is a continuous-time approximation that is derived under the assumption that sample size is small relative to the actual population size. In effect, this precludes multiple and simultaneous coalescent events that take place in the history of large samples. If sequences do not recombine, the number of sequences ancestral to a large sample is reduced sufficiently after relatively few generations such that use of the continuous-time approximation is justified. However, in tracing the history of large chromosomal segments, a large recombination rate per generation will consistently maintain a large number of ancestors. This can create a major disparity between discrete-time and continuous-time models and we analyze its importance, illustrated with model parameters typical of the human genome. The presence of gene conversion exacerbates the disparity and could seriously undermine applications of coalescent theory to complete genomes. However, we show that multiple and simultaneous coalescent events influence global quantities, such as total number of ancestors, but have negligible effect on local quantities, such as linkage disequilibrium. Reassuringly, most applications of the coalescent model with recombination (including association mapping) focus on local quantities.
Population Genetics of Polymorphism and Divergence Under Fluctuating Selection
Authors: Huerta-Sanchez Emilia , Durrett Rick , Bustamante Carlos D 
Published: October 2007

Abstract
Current methods for detecting fluctuating selection require time series data on genotype frequencies. Here, we propose an alternative approach that makes use of DNA polymorphism data from a sample of individuals collected at a single point in time. Our method uses classical diffusion approximations to model temporal fluctuations in the selection coefficients to find the expected distribution of mutation frequencies in the population. Using the Poisson random-field setting we derive the site-frequency spectrum (SFS) for three different models of fluctuating selection. We find that the general effect of fluctuating selection is to produce a more “U”-shaped site-frequency spectrum with an excess of high-frequency derived mutations at the expense of middle-frequency variants. We present likelihood-ratio tests, comparing the fluctuating selection models to the neutral model using SFS data, and use Monte Carlo simulations to assess their power. We find that we have sufficient power to reject a neutral hypothesis using samples on the order of a few hundred SNPs and a sample size of ∼20 and power to distinguish between selection that varies in time and constant selection for a sample of size 20. We also find that fluctuating selection increases the probability of fixation of selected sites even if, on average, there is no difference in selection among a pair of alleles segregating at the locus. Fluctuating selection will, therefore, lead to an increase in the ratio of divergence to polymorphism similar to that observed under positive directional selection.
Polymorphism in Multilocus Host–Parasite Coevolutionary Interactions
Authors: Tellier Aurélien , Brown James K M 
Published: October 2007

AbstractNumerous loci in host organisms are involved in parasite recognition, such as major histocompatibility complex (MHC) genes in vertebrates or genes involved in gene-for-gene (GFG) relationships in plants. Diversity is commonly observed at such loci and at corresponding loci encoding antigenic molecules in parasites. Multilocus theoretical models of host–parasite coevolution predict that polymorphism is more likely than in single-locus interactions because recurrent coevolutionary cycles are sustained by indirect frequency-dependent selection as rare genotypes have a selective advantage. These cycles are stabilized by direct frequency-dependent selection, resulting from repeated reinfection of the same host by a parasite, a feature of most diseases. Here, it is shown that for realistically small costs of resistance and virulence, polycyclic disease and high autoinfection rates, stable polymorphism of all possible genotypes is obtained in parasite populations. Two types of epistatic interactions between loci tend to increase the parameter space in which stable polymorphism can occur with all possible host and parasite genotypes. In the parasite, the marginal cost of each additional virulence allele should increase, while in the host, the marginal cost of each additional resistance allele should decrease. It is therefore predicted that GFG polymorphism will be stable (and hence detectable) when there is partial complementation of avirulence genes in the parasite and of resistance genes in the host.