bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gangarten des Rationalen. Zu den Zeitstrukturen der Quantenrevolution
Authors: Stöltzner Michael 
Published: June 2009

AbstractPaces of Rationality in the History of Science: On the Temporal Structures of the Quantum Revolution. I argue that the Kuhnian picture of scientific revolutions must be modified by introducing various levels of historical reality (or historiographical reconstruction) and reference points for rational justification in order to permit the constant movement back and forth between long shots and close‐ups that is indispensable in the history of science. Such an account makes it possible to describe a scientific revolution not as a simultaneous break on all levels, but as a sequence of ruptures on different levels, in which some levels allow the formulation of the new points of view or a justification of the transition. The proposed account appears reconcilable both with Michael Friedman's recent philosophical analysis of the dynamics of reason, even though it also admits of social and technological levels that are not representing a constitutive a priori, and Michel Foucault's archeology of nature, which does not contradict the fact that in studying the history of physical theory one typically finds precisely formulated and well‐separated levels of knowledge. It is ironic that Kuhn's original account, which helped to shape the ‘new epistemology’, is still largely indebted to the Logical Empiricists' conception of a single linguistic framework, the establishment of which is merely a matter of convention and pragmatics. At the example of Mara Beller's assessment of the quantum revolution. I argue that the Kuhnian picture represents an obstacle against assessing one particular trait of the German physics of the 1920s, the important formative part played by philosophical convictions of the German physicist‐philosophers.
Microarray‐based gene expression analysis as a process characterization tool to establish comparability of complex biological products: Scale‐up of a whole‐cell immunotherapy product
Authors: Wang Min , Senger Ryan S. , Paredes Carlos , Banik Gautam G. , Lin Andy , Papoutsakis Eleftherios T. 
Published: June 2009

AbstractWhole‐cell immunotherapies and other cellular therapies have shown promising results in clinical trials. Due to the complex nature of the whole cell product and of the sometimes limited correlation of clinical potency with the proposed mechanism of action, these cellular immunotherapy products are generally not considered well characterized. Therefore, one major challenge in the product development of whole cell therapies is the ability to demonstrate comparability of product after changes in the manufacturing process. Such changes are nearly inevitable with increase in manufacturing experience leading to improved and robust processes that may have higher commercial feasibility. In order to comprehensively assess the impact of the process changes on the final product, and thus establish comparability, a matrix of characterization assays (in addition to lot release assays) assessing the various aspects of the cellular product are required. In this study, we assessed the capability of DNA‐microarray‐based, gene‐expression analysis as a characterization tool using GVAX cancer immunotherapy cells manufactured by Cell Genesys, Inc. The GVAX immunotherapy product consists two prostate cancer cell lines (CG1940 and CG8711) engineered to secrete human GM‐CSF. To demonstrate the capability of the assay, we assessed the transcriptional changes in the product when produced in the presence or absence of fetal bovine serum, and under normal and hypoxic conditions, both changes intended to stress the cell lines. We then assessed the impact of an approximately 10‐fold process scale‐up on the final product at the transcriptional level. These data were used to develop comparisons and statistical analyses suitable for characterizing culture reproducibility and cellular product similarity. Use of gene‐expression data for process characterization proved to be a reproducible and sensitive method for detecting differences due to small or large changes in culture conditions as might be encountered in process scale‐up or unanticipated bioprocess failures. Gene expression analysis demonstrated that cell products of representative lots under the same production process and at the same production scale were statistically identical. Large process changes that resulted from the artificial stress conditions used (absence of FBS and induction of hypoxia) displayed profoundly different gene expression patterns. We propose the use of simple t‐test analysis in combination with the herein introduced expression ratio with mean intensity (ERMI) analysis as useful tools for process characterization by global gene expression analysis. Biotechnol. Bioeng. 2009; 104: 796–808 © 2009 Wiley Periodicals, Inc.
Enhanced IFNγ production in adenosine‐treated CHOCells: A mechanistic study
Authors: Chong William P. K. , Sim L. C. , Wong Kathy T. K. , Yap Miranda G. S. 
Published: June 2009

AbstractAdenosine causes growth arrest in recombinant mammalian cell cultures, which results in enhanced productivity of the recombinant protein. Adenosine is also known to increase intracellular ATP level when added to mammalian cells. As a cell's energy level affects its protein expression capacity, we investigated the factors that contribute to the increase in recombinant protein productivity. Chinese hamster ovary (CHO) cells expressing human interferon‐gamma (IFNγ) were treated with 1 mM adenosine on Day 2 of culture. The growth arrest resulted in 60% reduction in integral viable cell density when compared with control. However, IFNγ titer improved 1.4‐fold alongside a 2.5‐fold increase in average specific productivity. The adenosine‐treated cells also experienced a two‐fold increase in ATP level that sustained for 3 days. Western blot studies revealed a relatively short‐lived but strong activation of the energy sensor AMP‐activated protein kinase (AMPK) in adenosine‐treated cells. Activation of AMPK was probably due to adenosine being temporarily converted to AMP. Activated AMPK should have down‐regulated protein translation by preventing mammalian target of rapamycin (mTOR) from phosphorylating and inactivating 4E‐binding protein 1 (4E‐BP1), a key repressor of protein translation initiation. However, Western blots showed increased phosphorylation of 4E‐BP1 on Day 2 that lasted 3 days. This implied that a high concentration of ATP could keep 4E‐BP1 inhibited, probably by directly modulating mTOR. This corroborated with an earlier in vitro observation (Dennis et al., Science. 2001;294:1102‐1105). Inhibition of translation initiation repression is thus likely to contribute in part to the improvement in IFNγ‐specific productivity and titer. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Access of cellulase to cellulose and lignin for poplar solids produced by leading pretreatment technologies
Authors: Kumar Rajeev , Wyman Charles E. 
Published: June 2009

AbstractAdsorption of cellulase on solids resulting from pretreatment of poplar wood by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid (DA), flowthrough (FT), lime, and sulfur dioxide (SO2) and pure Avicel glucan was measured at 4°C, as were adsorption and desorption of cellulase and adsorption of β‐glucosidase for lignin left after enzymatic digestion of the solids from these pretreatments. From this, Langmuir adsorption parameters, cellulose accessibility to cellulase, and the effectiveness of cellulase adsorbed on poplar solids were estimated, and the effect of delignification on cellulase effectiveness was determined. Furthermore, Avicel hydrolysis inhibition by enzymatic and acid lignin of poplar solids was studied. Flowthrough pretreated solids showed the highest maximum cellulase adsorption capacity (σsolids = 195 mg/g solid) followed by dilute acid (σsolids = 170.0 mg/g solid) and lime pretreated solids (σsolids = 150.8 mg/g solid), whereas controlled pH pretreated solids had the lowest (σsolids = 56 mg/g solid). Lime pretreated solids also had the highest cellulose accessibility (σcellulose = 241 mg/g cellulose) followed by FT and DA. AFEX lignin had the lowest cellulase adsorption capacity (σlignin = 57 mg/g lignin) followed by dilute acid lignin (σlignin = 74 mg/g lignin). AFEX lignin also had the lowest β‐glucosidase capacity (σlignin = 66.6 mg/g lignin), while lignin from SO2 (σlignin = 320 mg/g lignin) followed by dilute acid had the highest (301 mg/g lignin). Furthermore, SO2 followed by dilute acid pretreated solids gave the highest cellulase effectiveness, but delignification enhanced cellulase effectiveness more for high pH than low pH pretreatments, suggesting that lignin impedes access of enzymes to xylan more than to glucan, which in turn affects glucan accessibility. In addition, lignin from enzymatic digestion of AFEX and dilute acid pretreated solids inhibited Avicel hydrolysis less than ARP and flowthrough lignin, whereas acid lignin from unpretreated poplar inhibited enzymes the most. Irreversible binding of cellulase to lignin varied with pretreatment type and desorption method. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Actin bundling in plants
Authors: Thomas Clément , Tholl Stéphane , Moes Danièle , Dieterle Monika , Papuga Jessica , Moreau Flora , Steinmetz André 
Published: June 2009

AbstractTight regulation of plant actin cytoskeleton organization and dynamics is crucial for numerous cellular processes including cell division, expansion and intracellular trafficking. Among the various actin regulatory proteins, actin‐bundling proteins trigger the formation of bundles composed of several parallel actin filaments closely packed together. Actin bundles are present in virtually all plant cells, but their biological roles have rarely been addressed directly. However, decades of research in the plant cytoskeleton field yielded a bulk of data from which an overall picture of the functions supplied by actin bundles in plant cells emerges. Although plants lack several equivalents of animal actin‐bundling proteins, they do possess major bundler classes including fimbrins, villins and formins. The existence of additional players is not excluded as exemplified by the recent characterization of plant LIM proteins, which trigger the formation of actin bundles both invitro and in vivo. This apparent functional redundancy likely reflects the need for plant cells to engineer different types of bundles that act at different sub‐cellular locations and exhibit specific function‐related properties. By surveying information regarding the properties of plant actin bundles and their associated bundling proteins, the present review aims at clarifying why and how plants make actin bundles. Cell Motil. Cytoskeleton 66: 940–957, 2009. © 2009 Wiley‐Liss, Inc.
Color rendering properties of light continuously modulated by an electrochromic switchable device
Authors: Gunde Marta Klanjšek , Ahtik Jure , Golob Gorazd , Krašovec Urša Opara 
Published: June 2009

AbstractEvery chromogenic switchable window gives rise to considerable change of spectral power distribution of the light crossing trough. The filtered light continuously changes during charging/discharging of the device, seen as its coloration/discoloration. As this process occurs continuously, it causes continuous change of colors on an illuminated multicolored scene. The ability of an electrochromic (EC) switchable unit to modulate daylight and different artificial lights passing through it is studied here. The color rendering properties of such a variable light are evaluated. The range of the effect and its consequences on the color of a scene can be adequately described by the change in chroma and hue angle during the modulation of light. These effects were evaluated by different light sources shining through the same EC unit. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 321–329, 2009
Simple waves do not avoid eigenvalue crossings
Authors: Chumakova Lyuba , Tabak Esteban G. 
Published: June 2009

AbstractGeneral one‐parameter families of matrices avoid eigenvalue crossings. It is shown that the matrices associated with the simple waves of nonlinear systems of conservation laws do not obey this rule: a subset of simple waves with nonzero measure has crossing eigenvalues. © 2009 Wiley Periodicals, Inc.
Diffusion with Moving Boundary on Spherical Surfaces
Authors: Amatore Christian , Klymenko Oleksiy V. , Oleinick Alexander I. , Svir Irina 
Published: June 2009

AbstractComing together:Surface diffusion of particles over a sphere and their clustering (see picture) may be adequately modelled by means of Brownian motion simulations or by using continuous Fick's diffusion law with a moving boundary in the low‐concentration limit.magnified imageIn this work, we illustrate two approaches to the simulation of surface diffusion over a sphere coupled with the formation of a cluster by reactive particles as a paradigm of a wide variety of problems occurring in many areas of nanosciences and biology. The problem is treated using a Brownian motion approach and a numerical solution of the corresponding continuous Fick’s laws of diffusion. While being computationally more expensive, the Brownian motion approach allows one to consider a wider range of situations, particularly those corresponding to relatively high concentrations of diffusing particles and the ensuing problem of particle overlap when they are ascribed finite sizes.
Stable, Non‐Destructive Immobilization of Native Nuclear Membranes to Micro‐Structured PDMS for Single‐Molecule Force Spectroscopy
Authors: Rangl Martina , Nevo Reinat , Liashkovich Ivan , Shahin Victor , Reich Ziv , Ebner Andreas , Hinterdorfer Peter 
Published: June 2009

AbstractStable anchorage: Micro‐structured polydimethylsiloxane serves as an optimal specimen‐support for immobilizing native nuclear membranes. It offers a solid basis for studying single‐molecule interaction of proteins involved in nucleocytoplasmatic transport (see figure).magnified imageIn eukaryotic cells the nucleus is separated from the cytoplasm by a double‐membraned nuclear envelope (NE). Exchange of molecules between the two compartments is mediated by nuclear pore complexes (NPCs) that are embedded in the NE membranes. The translocation of molecules such as proteins and RNAs through the nuclear membrane is executed by transport shuttling factors (karyopherines). They thereby dock to particular binding sites located all over the NPC, the so‐called phenylalanine‐glycin nucleoporines (FG Nups). Molecular recognition force spectroscopy (MRFS) allows investigations of the binding at the single‐molecule level. Therefore the AFM tip carries a ligand for example, a particular karyopherin whereas the nuclear membrane with its receptors is mounted on a surface. Hence, one of the first requirements to study the nucleocytoplasmatic transport mechanism using MRFS is the development of an optimized membrane preparation that preserves structure and function of the NPCs. In this study we present a stable non‐destructive preparation method of Xenopus laevis nuclear envelopes. We use micro‐structured polydimethylsiloxane (PDMS) that provides an ideal platform for immobilization and biological integrity due to its elastic, chemical and mechanical properties. It is a solid basis for studying molecular recognition, transport interactions, and translocation processes through the NPC. As a first recognition system we investigate the interaction between an important transport shuttling factor, importin β, and its binding sites on the NPC, the FG‐domains.
Impact of External Stimuli and Cell Micro‐Architecture on Intracellular Transport States
Authors: Mahowald Jean , Arcizet Delphine , Heinrich Doris 
Published: June 2009

AbstractUnraveling the fast and complex processes involved in intracellular transport: Herein, the authors use a rolling‐window analysis with very high temporal resolution to dissect the trajectory of an intracellular tracer and isolate transient active states (see graph). This is a signature of the activity which characterizes living materials.magnified imageA living cell is a complex out‐of‐equilibrium system, in which a great variety of biochemical and physical processes have to be coordinated to ensure viability. We investigate properties of intracellular transport in single cells of the amoeba Dictyostelium discoideum, a relevant model organism due to its cytoskeleton simplicity. In the cells, vesicles undergo two types of motion: directed transport, driven by molecular motors on filaments, or thermal diffusion in a crowded active medium. We present results obtained with our recently developed TRAnSpORT algorithm, which performs a high‐resolution temporal analysis of the track of endosomal superparamagnetic particles and splits intracellular transport into different motion states. It results in a two‐state model, distinguishing active and passive transport phenomena. We can extract the precise effect of cellular micro‐ and nanoarchitecture on endosomal transport by disturbing the cytoskeleton through the use of depolymerizing drugs (Benomyl for microtubules, and Latrunculin A for F‐actin). Further, we investigate how cytoskeleton filaments act together in order to maintain cell integrity, by applying external mechanical force on the magnetic particle and influencing its motion.
Community relations in the global mining industry: exploring the internal dimensions of externally orientated work
Authors: Kemp Deanna 
Published: June 2009

AbstractThis article focuses on community relations in the mining industry, within the context of sustainable development, social responsibility and stakeholder engagement. Community relations is conceptualized as a three‐dimensional practice that involves: working for the company to understand local community perspectives; bridging community and company perspectives to generate dialogue and mutual understanding and; facilitating necessary organizational change to improve social performance. Key challenges of institutionalizing and professionalizing community relations within the mining industry are discussed. The article argues that at a conceptual level, community relations should be de‐linked from public relations if it is to gain strength as a professional domain of work. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Determinants of environmental disclosure in the annual reports of large companies operating in Portugal
Authors: da Silva Monteiro Sónia Maria , Aibar‐Guzmán Beatriz 
Published: June 2009

AbstractSimilarly to what has happened in other countries, since the early 1990s Portuguese companies have developed corporate environmental reporting practices in response to internal and external factors. This paper is based on empirical research directed to both the study of environmental reporting practices developed by Portuguese companies and the identification of the factors that explain the extent to which these companies disclose environmental information. This study focuses on the environmental disclosures made in the annual reports by a sample of 109 large firms operating in Portugal during the period 2002–04. Using the content analysis technique we have developed an index in order to assess the presence of the environmental disclosures in companies' annual reports and their breadth. Based on the extant literature, several characteristics relating to firms' attributes were selected and their influence on the level of environmental disclosure was tested empirically. The selected explanatory variables were firm size, industry membership, profitability, foreign ownership, quotation on the stock market and environmental certification. The results reveal that, in spite of the fact that the level of environmental information disclosed during the period 2002–04 is low, the extent of environmental disclosure has increased as well as the number of Portuguese companies that disclose environmental information. Moreover, the firm size and the fact that a company is listed on the stock market are positively related to the extent of environmental disclosure. This study adds to the international research on environmental disclosure by providing empirical data from a country, Portugal, where empirical evidence is still relatively unknown, extending the scope of the current understanding of the environmental reporting practices. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Eigenvalue range determination for interval and parametric matrices
Authors: Kolev Lubomir 
Published: June 2009

AbstractStudy of the dynamic behaviour of linear limped parameter circuits or systems under parametric uncertainties is a well‐established research area. The present paper addresses the problem of determining the exact (within rounding errors) ranges for the real and imaginary parts of an eigenvalue of real matrices whose elements are either independent intervals or linear (affine) functions of independent interval parameters. A unified method for solving the above problem is suggested in the paper. It is iterative and reduces to forming and solving, at each iteration, two real (incomplete) quadratic systems to find outer interval bounds on the set of the right and left eigenvectors associated with the eigenvalue considered. The method is applicable if: (i) the solutions of both quadratic systems involved are positive and (ii) the outer interval bounds on the eigenvectors satisfy certain constant sign conditions. It is shown that its numerical complexity is polynomial in the size n of the matrix studied. Numerical examples illustrating the applicability of the new method are provided. Copyright © 2009 John Wiley & Sons, Ltd.
Methodological aspects of measuring absolute values of membrane potential in human cells by flow cytometry
Authors: Klapperstück Thomas , Glanz Dagobert , Klapperstück Manuela , Wohlrab Johannes 
Published: June 2009

AbstractThe bis‐barbituric acid oxonol, DiBAC4(3) is used as a standard potentiometric probe in human cells. However, its fluorescence depends not only on membrane potential but also varies with nonpotential related changes in the amount of intracellular free and bound dye. This study demonstrates the influence of different experimental conditions on this nonspecific fluorescence proportion. IGR1 melanoma cells as a model were specifically altered in cell volume and protein content by depolarizing treatments or cell cycle synchronization. Flow cytometry was performed over a wide range of extracellular DiBAC4(3) concentrations. Fixation and increase in protein content led to a nonspecifically enhanced fluorescence, while changes in the amount of free intracellular dye as a result of altered cell volume proved to be negligible. To establish a calibration curve using totally depolarized cells, the pore‐forming action of gramicidin should be preferred to fixation. Below 100 nM DiBAC4(3), the logarithmic relation between cell fluorescence and dye concentration turned into a virtually linear function intersecting with zero. Consequently, calibration can then be confined to determination of the fluorescence of depolarized cells stained with the same concentration as used for the actual measurement of membrane potential. Unexpectedly, quenching of fluorescence occurred in totally depolarized cells at concentrations higher than 6,250 nM. Linearity and quenching could be confirmed by additional experiments on Chinese hamster ovary CHO‐K1 and B lymphoblastoid LCL‐HO cells. © 2009 International Society for Advancement of Cytometry